SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
815 PM PDT SUN SEP 28 2008
.SHORT TERM (TONIGHT-WED)...LATEST ACARS SOUNDINGS FROM LAX SHOW THE
MARINE INVERSION REMAINS SHALLOW NEAR 800 FT DEEP. THE LOW CLOUDS
OVER THE SOCAL BIGHT THRU EARLY EVENING WERE MORE PATCHY THAN LAST
NIGHT BUT THE LOW CLOUDS SHOULD BECOME EXTENSIVE AGAIN TONIGHT AND
MOVE TO THE COAST AND INLAND SOME. CIGS ALONG THE VTU COAST WERE
AROUND 400 FT THIS EVENING WITH JUST LIGHT FOG. THE LOW CLOUDS THAT
EXPAND OVERNIGHT WILL LOWER SOME WITH PATCHY DENSE FOG POSSIBLE
LATER TONIGHT. LOW CLOUDS WERE ALREADY MOVING INLAND ALONG THE
CENTRAL COAST BUT NO DENSE FOG HAS BEEN REPORTED YET UNLIKE LAST
NIGHT AT THIS TIME. IT IS LOOKING MORE AND MORE LIKE JUST PATCHY
DENSE FOG WILL BE POSSIBLE FOR THE COASTAL AREAS OVERNIGHT INTO MON
MORNING. UNLIKE LAST NIGHT...A DENSE FOG ADVISORY IS NOT EXPECTED TO
BE ISSUED TONIGHT FOR THESE AREAS...WITH THE LOCALLY DENSE FOG
ALREADY IN THE FORECAST LOOKING REASONABLE. OTHERWISE SOME MID LEVEL
CLOUDS SHOULD LINGER OVER PARTS OF THE FORECAST AREA TONIGHT...BUT
FOR THE MOST PART MOSTLY CLEAR SKIES SHOULD PREVAIL ACROSS THE
REGION.
A BROAD BUT GENERALLY WEAK UPPER TROF IS FORECAST TO PERSIST OFF THE
SRN CA COAST THRU MON. THE UPPER TROF IS FORECAST TO WEAKEN FURTHER
AND MOVE E FOR TUE WHILE UPPER RIDGING BUILDS INTO SRN CA. A LARGE
UPPER TROF WILL APPROACH THE REGION FROM THE ERN PAC ON WED...
OTHERWISE SOME UPPER RIDGING WILL PERSIST OVER SRN CA. IT LOOKS LIKE
THE MID LEVEL FLOW OVER THE FORECAST AREA WILL BE S TO SE THRU MON
NIGHT...BECOME MORE VARIABLE FOR TUE INTO WED...EXCEPT SW FLOW AT
MID LEVELS OVER SLO/SBA COUNTIES WED AFTERNOON. SOME MID LEVEL
MOISTURE WILL PERSIST OVER THE FORECAST AREA THRU MON. THE WRF IS
INDICATING INCREASING INSTABILITY FOR MON AFTERNOON OVER THE
MOUNTAINS AS WELL...AND THE SLIGHT CHANCE OF SHOWERS OR
THUNDERSTORMS FOR THE L.A./VTU MTNS AND ANTELOPE VALLEY LOOKS
REASONABLE. THE MARINE LAYER SHOULD REMAIN ABOUT 800 FT OR SO THRU
WED. ANY MARINE LAYER CLOUDS DURING THE PERIOD SHOULD BE CONFINED
MAINLY TO THE COASTAL PLAIN DURING THE NIGHT AND MORNING
HOURS...WITH PATCHY LOW CLOUDS AND FOG INTO SOME OF THE ADJACENT
VALLEYS. AT LEAST PATCHY DENSE FOG AT TIMES WILL CONTINUE TO BE
POSSIBLE WITH THE LOW CLOUDS AS WELL. TEMPS OVER THE REGION ARE
FORECAST TO BE SEVERAL DEGREES ABOVE NORMAL FOR THE MOST PART THRU
WED...ESPECIALLY AWAY FROM THE COAST.
...FROM PREVIOUS DISCUSSION...
.LONG TERM (THU-SUN)...AS THE DEEP TROUGH FINALLY MOVES ASHORE TO
THE NORTH ON THU...ONSHORE FLOW SHOULD ABRUPTLY INCREASE WHILE
THICKS DECREASE...AND COOLING RELIEF WILL FINALLY STOP BEING
DELAYED. BASED ON MODELS USUALLY LIKING TO SLOW SYSTEMS LIKE THESE
DOWN AS WE GET CLOSER IN TIME...SPREAD COOLING OVER THU AND
FRI...BUT LIKELY ONE OF THOSE DAYS WILL SEE THE MAJORITY OF THE
COOLING DEPENDING ON THE SPEED OF THE TROUGH. HARD TO TELL WHAT THE
MARINE LAYER WILL DO AS A RESULT...BUT A DEEPER AND FURTHER
PENETRATING STRATUS PATTERN LOOKS BEST. WE MIGHT EVEN GET A LITTLE
NORTHWEST TO WEST WIND FROM THIS AS WELL. SAT THROUGH SUN SHOULD
START TO SEE A GENERAL WARMING TREND AS HIGH PRESSURE BUILDS OVER
THE ERN PACIFIC. THE NEW FEATURE IN THE 12Z GFS IS SOME MOIST
NORTHWEST FLOW BEHIND THE PREVIOUSLY MENTIONED SYSTEM. THIS COULD
AFFECT SLO AND NRN SBA COUNTY...AS WELL ALL NORTH FACING MTN
SLOPES...WITH SOME CLOUDS AND POPS. SINCE THIS IS NEW AND AT THE END
OF THE FORECAST WINDOW...DID NOT BITE ON THIS JUST YET...BUT WILL
CERTAINLY KEEP AN EYE ON IT.
&&
.AVIATION...29/0150Z...MODERATE TO HI CONFIDENCE LIFR CONDITIONS
WILL AFFECT ALL THE COASTAL AIRFIELDS OVERNIGHT INTO MON MORNING.
TIMING OF THE ARRIVAL OF LIFR CONDITIONS IS SOMEWHAT PROBLEMATIC FOR
SEVERAL AIRFIELDS SUCH AS KLAX...KLGB AND KSBA...BUT THEY WILL
EVENTUALLY HAVE THE LOW CLOUDS MOVE IN OVERNIGHT. ALL THE LOW CLOUDS
SHOULD CLEAR TO THE COAST OR OFF THE COAST BETWEEN 18Z AND 20Z MON
EXCEPT MAY LINGER TIL 22Z FOR KLAX AND KOXR. INLAND AREAS WILL HAVE
VFR CONDITIONS THRU MON.
FOR KLAX...MODERATE TO HI CONFIDENCE LOW CLOUDS AND LIFR CONDITIONS
WILL MOVE BACK INTO THE AIRFIELD THIS EVENING PROBABLY BEFORE 06Z.
THE LIFR CONDITIONS SHOULD IMPROVE TO IFR BY 16Z THEN VFR BY 22Z.
FOR KBUR...HI CONFIDENCE VFR CONDITIONS WILL PREVAIL THRU MON.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...SIRARD/KITTELL
AVIATION...SIRARD
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
330 PM PDT SUN SEP 28 2008
.DISCUSSION...
IT HIT AT LEAST 100 DEGREES IN RED BLUFF TODAY...AND SACRAMENTO WAS
95 AT 3 PM. TEMPERATURES WERE ALSO RUNNING WARM ALONG THE WEST SIDE
OF THE VALLEY...VACAVILLE AND TRAVIS AFB HAD BOTH EXCEEDED 95
DEGREES TODAY BY LATE AFTERNOON. LOW PRESSURE OVER THE EASTERN
PACIFIC WILL APPROACH NORTHERN CALIFORNIA TONIGHT AND
TOMORROW...SPREADING CLOUDS OVER THE AREA...DEEPENING THE MARINE
LAYER AND BRINGING SOME COOLER TEMPERATURES...THOUGH IT MAY BE A
BIT MORE HUMID. THE CANSAC MM5 DOES NOT SHOW MUCH OF A BREEZE THROUGH
THE DELTA THROUGH MONDAY.
THE SATELLITE SHOWS THE UPPER LOW ABOUT 500 MILES SOUTHWEST OF SAN
FRANCISCO THAT IS TAPING INTO SOME MOISTURE FROM A DEEP UPSTREAM
TROF. A SOUTHEAST FLOW IN THE MID LEVELS IS IN PLACE. MODEL FORECAST
SOUNDINGS SHOW THE MID LEVEL CAP WILL BREAK THIS AFTERNOON...AND WE
HAVE SEEN A LIGHTNING STRIKE OR TWO ALONG THE WEST SLOPE OF THE
SIERRA. HOWEVER AIRCRAFT SOUNDINGS INDICATE THIS CAP IS HOLDING
FARTHER NORTH. WE HAVE ISOLATED THUNDER IN THE FORECAST ALONG THE
WEST SLOPE OF THE SIERRA THIS EVENING...MAINLY SOUTH OF INTERSTATE
80. THE GFS INDICATED A LOT OF MOISTURE WILL LIFT INTO THE LASSEN
PARK AREA TONIGHT...AND THIS MODEL GENERATES SOME QPF IN UPPER
DIFFLUENCE AHEAD OF THE APPROACHING LOW. THE NAM-12 HAS THIS
MOISTURE AS WELL...BUT NO QPF. PER SHORT RANGE ENSEMBLES...WILL
INCLUDE ISOLATED SHOWERS FARTHER NORTH TO THE LASSEN AREA UNTIL
AROUND MIDNIGHT. ANY SHOWERS SHOULD BE FAIRLY LIGHT.
ON MONDAY...THE LOW WILL TAKE ON A NEGATIVE TILT...BRINGING A GOOD
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE SIERRA...LASSEN PARK AREA
AND PERHAPS NORTHERN MOUNTAINS. OVERDEVELOPMENT IS LIKELY TO TURN
ALL OF THE PRECIPITATION TO RAIN SHOWERS MONDAY NIGHT. THE MODELS
HAVE PICKED UP ON THE SLOWER TIMING OF THE DEEP UPSTREAM LOW ALONG
150W...MEANING ISOLATED SHOWERS COULD LINGER INTO TUESDAY NEAR THE
SIERRA BEFORE THE FLOW TURNS FROM SOUTH TO SOUTHWESTERLY.
THE GFS AND ECMWF BOTH SUPPORT KEEPING WEDNESDAY DRY IN THIS
AMPLIFIED PATTERN. SG
.EXTENDED DISCUSSION (THURSDAY THROUGH SUNDAY)...
THE RIDGE OF HIGH PRESSURE SHIFTS TO THE EAST WITH AN UPPER LEVEL
TROUGH MOVING ONTO THE WEST COAST ON THURSDAY. ANOTHER TROUGH IS
EXPECTED TO MOVE ONSHORE LATE FRIDAY INTO SATURDAY. THE GFS
ENSEMBLE SPREAD WITH THESE SYSTEMS IS SMALLER THAN IT WAS YESTERDAY
GIVING A LITTLE MORE CONFIDENCE. THE FORECAST LEANS TOWARDS THE GFS
ENSEMBLE WHICH IS STILL NOT QUITE AS DEEP WITH THE TROUGH AS THE
ECMWF BUT DEEPER THAN THE 12Z OPERATIONAL GFS. THE TROUGHS MOVING
THROUGH WILL BRING COOLER TEMPERATURES THURSDAY INTO SATURDAY. THE
SYSTEMS WILL ALSO BRING A THREAT OF PRECIPITATION. PRECIPITATION IS
EXPECTED TO BE IN THE NORTHERN PORTION OF THE CWA (MAINLY NORTH OF
INTERSTATE 80) ON THURSDAY AND EARLY FRIDAY AND THEN SPREAD ACROSS
THE ENTIRE CWA WITH THE SYSTEM LATE FRIDAY INTO SATURDAY.
PRECIPITABLE WATER VALUES ARE EXPECTED TO BE AROUND 0.75 INCHES TO
ABOUT 1.10 INCHES ON THURSDAY AFTERNOON AND INCREASE TO AROUND AN
INCH TO AN INCH AND A HALF FRIDAY AFTER WITH A MOISTURE PLUME NOSING
INTO THE BAY AREA. AT THIS TIME...THE BEST CHANCE OF PRECIPITATION
LOOKS LIKE IT WILL BE ON FRIDAY EVENING INTO SATURDAY MORNING WITH
GOOD DYNAMICS AS A 150 KT JET BRUSHES THROUGH NORTHERN CALIFORNIA. A
RIDGE OF HIGH PRESSURE MAY BUILD OVER THE EASTERN PACIFIC AND INTO
NORTHERN CALIFORNIA ON SUNDAY BRINGING DRIER AND WARMER WEATHER.
&&
.AVIATION...
MOSTLY CLEAR SKIES AND VFR CONDITIONS OVER THE SACRAMENTO VALLEY
THIS AFTERNOON. CUMULUS CLOUDS HAVE DEVELOPED OVER THE SIERRA THIS
AFTERNOON...WITH SHOWERS AND THUNDERSTORMS POSSIBLE. EXPECT MID
LEVEL FLOW FROM THE SOUTHEAST AT ABOUT 25 KTS TONIGHT...CHANGING TO
SOUTHERLY MONDAY AFTERNOON. GENERALLY LIGHT SURFACE WINDS ARE
EXPECTED INTO MONDAY AFTERNOON. FG/HSO
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
230 PM PDT SUN SEP 28 2008
.SYNOPSIS...A SHALLOW MARINE LAYER WILL CONTINUE COASTAL LOW CLOUDS
AND LOCAL DENSE FOG DURING THE NIGHTS AND MORNINGS. MID LEVEL
MOISTURE IN SOUTHEAST FLOW ALOFT WILL BRING A SLIGHT CHANCE OF
THUNDERSTORMS TO THE MOUNTAINS AND HIGH DESERTS MONDAY AFTERNOON. AN
UPPER LEVEL TROUGH OF LOW PRESSURE WILL BRING COOLING WITH A DEEPER
MARINE LAYER TOWARD THE END OF THE WEEK.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TODAY-WED...THERE WERE LOW CLOUDS AND AREAS OF DENSE
FOG IN THE COASTAL SECTIONS AND WRN SAN DIEGO INLAND VALLEYS THIS
MORNING BUT CLEARED BACK TO NEAR THE BEACHES. CLEAR ELSEWHERE EXCEPT
FOR A FEW CU OVER THE MOUNTAINS. EARLY AFTERNOON ACARS SOUNDINGS
INDICATED AN INVERSION BASED BELOW 1000 FT. WEAK OFFSHORE FLOW FROM
THE N AND ONSHORE TO THE E WITH ABOUT 4 MB SAN-IPL.
A WEAK UPPER TROUGH OFF THE COAST WILL ROTATE NE AND WEAKEN THROUGH
MON AND THEN A LARGER TROUGH IN THE ERN PAC WILL SLOWLY APPROACH THE
W COAST. A RIDGE OF HIGH PRESSURE WILL CONTINUE OVER THE SW THROUGH
THE SHORT TERM. THERE WILL BE RELATIVELY SMALL CHANGES IN LOCAL
HEIGHTS. THIS WILL RESULT IN MINOR TEMP CHANGES WITH CONTINUED WARM
DAYS INLAND AND MAX TEMPS ABOUT 5 TO 10 DEGREES ABOVE SEASONAL
AVERAGES. THE MARINE INFLUENCE WILL KEEP MAX TEMPS NEAR THE COAST AT
OR A LITTLE BELOW SEASONAL. THE MARINE LAYER WILL BE SHALLOW WITH
WITH LOW CLOUDS AND FOG INTO THE COASTAL AREAS AND FAR WRN SAN DIEGO
INLAND VALLEYS DURING THE NIGHTS AND MORNINGS. FOG WILL BE LOCALLY
DENSE NEAR THE INLAND EXTENT OF THE STRATUS AND ON HIGHER COASTAL
TERRAIN. LOW CLOUDS WILL LINGER NEAR THE SOME BEACHES INTO THE
AFTERNOONS TRAPPED UNDER A STRONG INVERSION. SE FLOW WILL BRING IN
LIMITED MID LEVEL MOISTURE BUT MODELS CONTINUE TO DIFFER ON THE
DETAILS. THERE SHOULD AT LEAST BE SOME MID LEVEL CLOUDS AND A FEW
AFTERNOON CU OVER THE MOUNTAINS. THERE MAY BE ENOUGH MOISTURE AND
INSTABILITY FOR A FEW THUNDERSTORMS OVER THE MOUNTAINS AND HIGH
DESERTS MONDAY AFTERNOON.
&&
.LONG TERM (THU-SUN)...THE E PAC UPPER TROUGH WILL MOVE THROUGH
TOWARD THE END OF THE WEEK FOLLOWED BY DRY NW FLOW. THIS WILL BRING
COOLING AND A DEEPENING MARINE LAYER THROUGH SAT AND DRYING IN THE
MID LEVELS. A LITTLE WARMER SUN AS HEIGHTS RECOVER. STRONGER ONSHORE
FLOW AND WINDS ALOFT SHOULD CAUSE LOCAL GUSTY WINDS...MAINLY IN THE
MOUNTAINS AND DESERTS SAT AFTERNOON AND EVENING.
&&
.AVIATION...
282000Z...19Z MDCRS SOUNDINGS SHOW MARINE LAYER DEPTH REMAINS AROUND
900 FT. STRATUS HAS ALREADY MOVED BACK INLAND A FEW MILES ALONG THE
CENTRAL SAN DIEGO COUNTY COAST...INCLUDING KCRQ. VISIBLE SATELLITE
IMAGERY SHOWS STRATUS STARTING TO BREAK UP IN THIS AREA...SO STRATUS
WILL LIKELY BE MOVING IN AND OUT OF THE AREA THROUGHOUT THE
AFTERNOON. CU OVER THE MTNS HAS DEVELOPED...BUT SHOULD DISSIPATE
AFTER SUNSET. VSBYS BETWEEN 3-6SM IN HZ ALONG THE IMMEDIATE COAST
WILL PERSIST THROUGH THE EVENING.
STRATUS WILL MOVE BACK INLAND ALONG THE REST OF THE COAST THIS
EVENING AND SHOULD REACH KSNA AND KSAN BETWEEN 03 AND 06Z TONIGHT.
AREAS OF DENSE FOG WILL FORM AT THE COASTAL AIRPORTS AFTER 10Z
MONDAY MORNING. STRATUS AND FOG WILL EXTEND 10 TO 15 MILES INLAND.
CIGS WILL BE AROUND 300 FT MSL WITH TOPS NEAR 1K FT MSL. CLEARING
SHOULD BEGIN AGAIN BY 16Z.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...ATKIN
AVIATION...SS
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
930 AM PDT SAT SEP 27 2008
.SYNOPSIS...A SLOWLY DEEPENING MARINE LAYER AND ONSHORE FLOW WILL
BRING COASTAL LOW CLOUDS AND FOG DURING THE NIGHTS AND
MORNINGS...EXTENDING LOCALLY INLAND. AREAS OF DENSE FOG TONIGHT AND
SUNDAY MORNING. MID LEVEL MOISTURE IN SOUTHEAST FLOW WILL CAUSE A
SLIGHT CHANCE OF THUNDERSTORMS IN THE MOUNTAINS SUNDAY AND MONDAY.
THERE WILL BE A GRADUAL COOLING TREND THROUGH NEXT WEEK AS UPPER
LEVEL LOW PRESSURE IN THE EASTERN PACIFIC APPROACHES THE WEST COAST.
&&
.DISCUSSION...FOR SOUTHWEST CALIFORNIA INCLUDING SAN DIEGO...
ORANGE...SOUTHWEST SAN BERNARDINO AND WEST RIVERSIDE COUNTIES.
.SHORT TERM (TODAY-TUE)...THERE WERE AREAS OF DENSE FOG THIS MORNING
IN THE COASTAL SECTIONS AND FAR WRN SAN DIEGO INLAND VALLEYS. MOSTLY
CLEAR ELSEWHERE. THE 12Z NKX SOUNDING HAD A STRONG INVERSION BASED
BELOW 1000 FT WITH DRY WLY WINDS ALOFT. WEAK OFFSHORE GRADIENTS FROM
THE N AND ONSHORE TO THE E WITH ABOUT 5 MB SAN-IPL.
UPPER LEVEL HIGH PRESSURE WILL REMAIN OVER THE SW WITH A WEAK TROUGH
OFF THE COAST. THIS WILL CAUSE A SE FLOW THAT WILL BRING IN LIMITED
MID LEVEL MOISTURE. WHILE THE MOISTURE WILL BE A LITTLE HIGHER THAN
OPTIMAL FOR THUNDERSTORMS...THERE COULD STILL BE ENOUGH INSTABILITY
FOR A FEW THUNDERSTORMS OVER THE MOUNTAINS SUN AND MON. THE MARINE
LAYER WILL REMAIN SHALLOW DESPITE SLIGHT DEEPENING THROUGH THE SHORT
TERM. THIS SHOULD AGAIN RESULT IN LOCAL DENSE FOG NEAR THE INLAND
EXTENT OF THE STRATUS AND ON HIGHER COASTAL TERRAIN DURING THE
NIGHTS AND MORNINGS. A LITTLE COOLER SUN AND MON THEN NOT MUCH
CHANGE TUE. IT WILL STILL BE WARM INLAND DESPITE THE GRADUAL
DOWNWARD TREND IN TEMPS.
&&
.LONG TERM (WED-SAT)...A LARGE UPPER LEVEL TROUGH IN THE ERN PAC
WILL APPROACH THE W COAST AND MOVE THROUGH ON SAT. THIS WILL BRING A
COOLING TREND AND A DEEPENING MARINE LAYER. DRIER SW FLOW
ALOFT...EXCEPT FOR MORE HIGH LEVEL CLOUDS TOWARD THE END OF NEXT
WEEK.
&&
.AVIATION...
271500Z...STRATUS AND AREAS OF DENSE FOG HAS FILLED IN OVER THE
COASTAL WATERS...EXTENDING ABOUT 10 MI INLAND IN SAN DIEGO AND
NORTHERN ORANGE COUNTIES. LATEST ACARS SOUNDING SHOWS MARINE LAYER
DEPTH OF 800 FT. BASES ARE AROUND 300 FT MSL WITH TOPS NEAR 1K FT
MSL. FOG AND STRATUS SHOULD BEGIN TO BREAK UP AT COASTAL AIRPORTS
AFTER 16Z...CLEARING BY 18Z. STRATUS AND FOG MAY LINGER AT THE
IMMEDIATE COAST THROUGH THE AFTERNOON. ABOVE THE MARINE
LAYER...UNRESTRICTED VISIBILITIES AND CLEAR SKIES...EXCEPT FOR CU
OVER THE MTNS AFTER 18Z.
LITTLE CHANGE IN THE MARINE LAYER DEPTH IS EXPECTED SUNDAY. STRATUS
SHOULD RETURN TO THE COASTAL AIRPORTS BETWEEN 06Z AND 08Z...WITH
AREAS OF DENSE FOG FORMING ALONG THE COAST AFTER 10Z. STRATUS SHOULD
EXTEND INLAND ABOUT 10 TO 15 MI. CLEARING WILL BEGIN AGAIN AFTER 16Z
SUNDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...ATKIN
AVIATION...SS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
351 PM EDT SUN SEP 28 2008
.SYNOPSIS...
HURRICANE KYLE IS EXPECTED TO PASS 140 MILES EAST OF NANTUCKET AND
CAPE COD LATE THIS MORNING/EARLY AFTERNOON. THE STORM LOOKS TO PASS
FAR ENOUGH EAST TO CONFINE TROPICAL STORM FORCE WINDS TO OUR OUTER-
WATERS EAST OF CAPE COD/NANTUCKET. OTHERWISE...THE MODERATE TO HEAVY
RAIN SHOULD COME TO AN END ALONG THE COAST BY AFTERNOON. DRY AND
SEASONABLE WEATHER EXPECTED MONDAY AND TUESDAY. LOW PRESSURE WILL
TRACK ACROSS NORTHERN NEW ENGLAND WEDNESDAY ALONG WITH ITS ATTENDING
COLD FRONT. THIS FEATURE WILL BRING A PERIOD OF SHOWERS TO SOUTHERN
NEW ENGLAND FROM LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. DRY AND
COOLER WEATHER IS EXPECTED BEHIND THE FRONT THURSDAY...FRIDAY AND
SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE TO REMOVE TROPICAL STORM WARNING HEADLINES...AS WELL AS
FRESHENING THE HWO.
KYLE CONTINUES TO TRACK NNE ACROSS THE OFFSHORE WATERS ESE OF NEW
ENGLAND. SOME WRAP AROUND MOISTURE CONTINUED TO CONVERGE ACROSS
EASTERN MASSACHUSETTS...BUT THE HEAVIEST RAINFALL FROM KYLE WILL
REMAIN JUST EAST OF THE REGION. IN ADDITION THE NEXT UPPER LEVEL LOW
LOCATED ACROSS EASTERN PENNSYLVANIA WILL BE TRACKING EAST THIS
AFTERNOON. MADE SOME MINOR MODIFICATIONS TO POPS ACCORDINGLY. ALSO
LOWERED MAX TEMPS SLIGHTLY GIVEN ABUNDANT LOW LEVEL MOISTURE.
THERE IS ANOTHER SHORTWAVE THAT MOVES INTO THE INTERIOR...SO THIS
WILL BRING A FEW HIT AND MISS SHOWERS. IN ADDITION...WILL ALSO INSERT A
SLIGHT CHANCE OF THUNDER INTO THE FAR INTERIOR. 500 MB TEMPERATURES
ARE AROUND -12C IN THE AFTERNOON. IT LOOKS LIKE SKIES WILL BE RATHER
CLOUDY...BUT MAY SEE A FEW BREAKS IN THE AFTERNOON BACK IN THE
INTERIOR. THAT MAY PROVIDE JUST ENOUGH DE STABILIZATION FOR A BIT OF
THUNDER. LATER FORECASTS MAY WANT TO UP THE THUNDER CHANCES IF MORE
BREAKS IN THE OVERCAST DEVELOP THAN EXPECTED. ACROSS THE COASTAL
PLAIN...THINK IT SHOULD PRETTY MUCH REMAIN CLOUDY ALL DAY.
IN ADDITION...HIGH SEAS OVER THE OPEN WATERS FROM KYLE WILL CREATE
HIGH SURF AND DANGEROUS RIP CURRENTS FOR THE OCEAN EXPOSED BEACHES
OF THE CAPE AND ISLANDS. WILL JUST INCLUDE MENTION OF THIS IN THE
HURRICANE LOCAL STATEMENT INSTEAD OF ISSUING ANOTHER HIGH SURF
ADVISORY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TONIGHT...
SHORTWAVE CONTINUES TO MOVE THROUGH THE REGION. WILL JUST RUN WITH
SOME LOW CHANCE POPS FOR A FEW POPUP SHOWERS. THE POTENTIAL FOR
SCATTERED SHOWERS WILL DIMINISH FROM NORTHWEST TO SOUTHEAST THROUGH
THE NIGHT...AS THE SHORTWAVE AND WEAK COLD FRONT PUSH THROUGH THE
REGION. LOW TEMPERATURES SHOULD MAINLY BE BETWEEN 55 AND 60.
SKIES SHOULD GENERALLY REMAIN MOSTLY CLOUDY TONIGHT. HOWEVER...WE
COULD SEE SOME PARTIAL CLEARING TAKE PLACE ACROSS THE INTERIOR NEAR
DAYBREAK. IF THIS HAPPENS...THE WET GROUND AND RELATIVELY HIGH
DEWPOINTS IN PLACE COULD RESULT IN THE FORMATION OF PATCHY DENSE
GROUND FOG.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/...
MONDAY...
CHANCE OF A SHOWER DURING THE MORNING ACROSS SOUTHEAST MA INCLUDING
CAPE COD AND THE ISLANDS...AS THE COLD FRONT AND SURFACE WAVE ON THE
FRONT ARE SLOW TO EXIT OFFSHORE. HOWEVER...BY MIDDAY FRONT PUSHES
OFFSHORE WITH DEEP LAYER ANTICYCLONIC FLOW MOVING ACROSS THE REGION
FROM WEST TO EAST. THIS WILL PROMOTE AT LEAST PARTIAL CLEARING WITH
SOME AFTERNOON SUNSHINE. SURFACE FLOW BECOMES LIGHT NORTH-NORTHEAST.
THIS MAY KEEP LOW CLOUDS ACROSS EASTERN MA AND RI. THEREFORE...
EXPECTING MORE SUNSHINE ACROSS CT AND WEST-CENTRAL MA.
POST FRONTAL FLOW WILL RESULT IN A LESS HUMID AIRMASS OVERSPREADING
THE REGION. TEMPERATURES SHOULD BE SEASONABLE...ESPECIALLY ACROSS CT
AND WEST-CENTRAL MA WHERE MORE SUNSHINE IS EXPECTED. OVERALL...A
MAJOR IMPROVEMENT FROM THIS WEEKENDS WEATHER.
MONDAY NIGHT AND TUESDAY...
SHORT WAVE RIDGING ACROSS THE REGION WILL PROVIDE DRY AND SEASONABLE
WEATHER. TRICKY PART OF THE FORECAST HERE IS SKY CONDITIONS. MODELS
HINT AT LOTS OF POST FRONTAL STRATO-CUMULUS. THIS SEEMS PLAUSIBLE AS
LIGHT NNE POST FRONTAL FLOW MONDAY NIGHT MAY TRAP MOISTURE BENEATH
SUBSIDENCE INVERSION. THEN WINDS SHIFT TO SOUTHEAST TUE. FOR NOW
WILL CALL IT PARTLY CLOUDY...BUT CLOUDS COULD DOMINANT MON NIGHT AND
TUE. NEVERTHELESS DRY WEATHER WILL PREVAIL.
TUESDAY NIGHT AND WEDNESDAY...
MODELS CONTINUE TO ADVERTISE A POTENT SHORT WAVE TROF DIVING
SOUTHEAST ACROSS THE GREAT LAKES INTO THE OH VALLEY TUE NIGHT AND
WED. PRIMARY LOW MOVES ACROSS THE ST. LAWRENCE RIVER VALLEY WED/WED
NIGHT WITH ITS ATTENDING COLD FRONT ACROSS NEW ENGLAND. GFS MOS
OFFERS LIKELY POPS WED. THIS SEEMS REASONABLE GIVEN GOOD MODEL
AGREEMENT ON THE AMPLITUDE AND TIMING OF THIS SYSTEM. THEREFORE
CHANCE OF SHOWERS LATE TUE NIGHT INTO WED NIGHT...WITH LIKELY POPS
WED.
THURSDAY/FRIDAY AND SATURDAY...
THE TREND THURSDAY SHOULD BE FOR DRYING CONDITIONS AS SURFACE TROF
MOVES OFFSHORE EARLY IN THE DAY. COOLER TEMPS BEHIND THE FRONT WITH
HIGHS PROBABLY IN THE 60S THU. CAN/T RULE OUT AN ISOLATED SHOWER THU
AS MID LEVEL TROF MOVES ACROSS THE NORTHEAST.
A SECONDARY SHORT WAVE AND ACCOMPANYING SURFACE TROF MOVE THROUGH
SOUTHERN NEW ENGLAND FRI OR SAT...DELIVERING A REINFORCING SHOT OF
COOL AIR. 00Z GFS/ECMWF AND ENSEMBLES ARE IN VERY GOOD AGREEMENT
WITH 850 TEMPS COOLING OFF TO AROUND 0C FRI/SAT. THEREFORE...HIGHS
MAY ONLY CLIMB INTO THE MID TO UPPER 50S FRI/SAT. FOR NOW WE
FOLLOWED THE MILDER GFS MOS GIVEN ITS A DAY 7 FORECAST. ALTHOUGH IF
THE SAME TRENDS APPEAR IN THE 12Z MODELS...THE DAY SHIFT MAY WANT TO
ADJUST DOWNWARD FRI AND SAT MAXES.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
FORECASTING IMPROVING CONDITIONS TO MVFR CIGS AND VFR VSBYS BY
AROUND 18Z. REMAINING IFR OVER EAST COASTAL AREAS THROUGH AT LEAST
EARLY AFTERNOON. MAY NOTE SOME IMPROVEMENT AT KBOS AFTER 19Z- 20Z.
TONIGHT...MVFR-IFR CIGS CONTINUING...THOUGH MAY BREAK OUT TO VFR
OVER THE CT VALLEY. MAY SEE PATCHY IFR VSBYS IN FOG DEVELOP AFTER
06Z.
OUTLOOK...MONDAY THROUGH THURSDAY...
MONDAY...LEFTOVER IFR/MVFR CEILINGS HYA AND ACK IN SPOTTY SHOWERS
AND MORNING FOG PATCHES...IMPROVING TO MVFR/VFR ALL TERMINALS BY
MIDDAY.
TUESDAY...MVFR/VFR CIGS.
TUESDAY NIGHT/WED/WED NIGHT...MVFR CEILINGS AND VSBYS IN SHOWERS AND FOG
PATCHES...WITH LOCAL IFR CONDITIONS POSSIBLE.
THU...VFR LIKELY ALL TERMINALS WITH COLD FRONT MOVING OFFSHORE..
&&
.MARINE...
TODAY...
TROPICAL STORM WARNINGS REMAIN IN EFFECT FOR OUR EASTERN OUTER
WATERS OF ANZ250-254. SO FAR HURRICANE HUNTER AIRCRAFT REVEALS
LITTLE WIND ON THE WEST SIDE OF THE STORM. HOWEVER...MODELS
INDICATE THAT AS IT BEGINS ITS EXTRA-TROPICAL TRANSITION IT MAY BE
ABLE TO WRAP TROPICAL STORM FORCE WINDS INTO OUR EASTERN
OUTER-WATERS. THEREFORE...TROPICAL STORM WARNINGS CONTINUE. WE MAY
ALSO SEE WAVE HEIGHTS INCREASE TO OVER 15 FEET SOUTH AND EAST OF
NANTUCKET THIS AFTERNOON.
JUST TO THE WEST OF ANZ250-254 WILL CONTINUE WITH STRONG SCA FOR THE
SOUNDS...CAPE COD AND BUZZARDS BAY. HOWEVER...WE MAY SEE A BRIEF
WIND GUST OR TWO TO 35 KNOTS LATER THIS MORNING/AFTERNOON IN THE
EASTERN PORTIONS OF CAPE COD BAY AND NANTUCKET SOUND.
TONIGHT...
WINDS DROP BELOW CRITERIA TONIGHT. HOWEVER...WILL NEED TO EXTEND
HEADLINES FOR THE OUTER-WATERS AND SOUNDS FOR LEFTOVER HIGH SEAS.
OUTLOOK...MONDAY THROUGH THURSDAY...
MONDAY AND TUESDAY...
LIGHT WINDS WITH LEFTOVER E SWELLS MON ACROSS THE OCEAN WATERS.
TUE NIGHT/WED/WED NIGHT...
LOW PRES TRACKS ACROSS THE ST LAWRENCE RIVER VALLEY WITH ITS COLD
FRONT SWEEPING ACROSS NEW ENGLAND. WIDESPREAD SHOWERS ALONG AND
AHEAD OF THE FRONT. VSBY MAY BE LESS THAN 3 MILES IN SHOWERS AND FOG.
THURSDAY...WEST TO SOUTHWEST WINDS BEHIND THE COLD FRONT MAY REACH
20-25 KT.
&&
.HYDROLOGY...
THE FLOOD WATCH FOR SOUTHEASTERN MASSACHUSETTS AS BEEN CANCELLED.
PLEASE REFER TO THE LATEST FFABOX CANCELLATION STATEMENT.
THE FLOOD WATCH HAS BEEN TRIMMED TO NOW ONLY INCLUDE EASTERN MA THIS
MORNING. LITTLE IF ANY STEADY RAIN IS EXPECTED ACROSS THE INTERIOR
SO THE FLOOD WATCH HAS BEEN DROPPED FOR THE REST OF THE REGION. THE
HEAVIEST RAIN FROM KYLE WILL FOCUS ITSELF OVER THE CAPE/ISLANDS.
HOWEVER...THERE HAS BEEN SOME URBAN FLOODING IN EASTERN MA AND WITH
ANOTHER 0.50 TO 1 INCH OF RAIN THROUGH THE MORNING HOURS WILL
CONTINUE WITH THE WATCH.
ALL THE STEADY RAIN ON THE COAST WILL BE OVER BY EARLY AFTERNOON
WITH NO ADDITIONAL FLOODING EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR ANZ250-254-255.
SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR ANZ235-237.
&&
$$
SYNOPSIS...NOCERA/FRANK
NEAR TERM...NOCERA/FRANK/STRAUSS
SHORT TERM...FRANK/STRAUSS
LONG TERM...NOCERA
AVIATION...NOCERA/EVT
MARINE...NOCERA/FRANK
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1131 AM EDT SAT SEP 27 2008
.SYNOPSIS...
LOW PRESSURE OVER THE MID ATLANTIC STATES COMBINED WITH THE BERMUDA
HIGH CONTINUES A TROPICAL CONVEYOR BELT OF MOISTURE INTO SOUTHERN
NEW ENGLAND...YIELDING A PERIOD OF VERY HEAVY RAIN THIS AFTERNOON
OR TONIGHT AS PRECURSOR EVENT TO THE NEARBY PASSAGE OF TROPICAL STORM
KYLE. KYLE IS EXPECTED TO PASS EAST OF NEW ENGLAND SUNDAY...POSSIBLY
BRINGING A PERIOD OF STRONG WINDS AND HEAVY RAIN TO CAPE COD NANTUCKET
AND THE OUTER MASSACHUSETTS COASTAL WATERS. FOR THE LATEST INFORMATION ON
KYLE...VISIT THE NATIONAL HURRICANE CENTER WEBSITE FOR DETAILS AS WELL
AS NWS TAUNTON HURRICANE LOCAL STATEMENTS ISSUED THIS AFTERNOON. DRY
AND SEASONABLE WEATHER WILL RETURN EARLY NEXT WEEK...WITH THE NEXT
CHANCE OF RAIN ARRIVING AROUND MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MODEL FEEL IS STILL NOT GOOD THIS MORNING... ALL MODELS TENDING TO
STRUGGLE AT 930AM ANALYSIS. WE ARE GOING TO WING IT A BIT WITH TPC
GUIDANCE ON KYLE ITSELF. WE MAY BE HEADED FOR A PRE EVENT TONIGHT
ALONG THE I 95 CORRIDOR.
NOT MUCH RAIN FELL ACROSS THE REGION OVERNIGHT WITH A LONG LULL IN
THE ACTIVITY. AS IS TYPICALLY THE CASE...ONCE WE ENTERED THE WARM
SECTOR THE PRECIPITATION SHIELD BECAME SHOWERY IN NATURE AND THE
MODELS TEND TO STRUGGLE WHERE AND WHEN IT WILL OCCUR.
NONETHELESS...MODELS INDICATE THAT ANOTHER GOOD PULSE OF HEAVY RAIN
WILL BE MOVING INTO THE REGION LATER THIS MORNING AND AFTERNOON.
THERE IS ANOTHER GOOD SHORTWAVE EMBEDDED IN MERIDIONAL FLOW WHICH
WILL INTERACT WITH AN INVERTED TROUGH. THE GFS HAS VERY INTENSE
LIFT MOVING NORTHWARD ACROSS THE REGION THIS AFTERNOON. THIS
COMBINED WITH PWATS OVER 2 INCHES HAVE THE INGREDIENTS FOR MORE
HEAVY RAIN. RADAR IMAGERY ALSO SHOWS THE BEGINNING OF THIS ACTIVITY
OFF THE MID ATLANTIC COAST. THEREFORE...WILL BRING POPS BACKUP TO
CATEGORICAL LATER THIS MORNING AND AFTERNOON. RAINFALL AMOUNTS MAY
VARY CONSIDERABLY ACROSS THE REGION SINCE WE WILL BE ENTERING THE
WARM SECTOR AND THE PRECIPITATION WILL BE MORE SHOWERY. HOWEVER...WITH
INTENSE FORCING AND HIGH PWATS POCKETS OF TORRENTIAL RAINFALL ARE
EXPECTED. WE EXPECT AN ADDITIONAL 1 TO 3 INCHES OF RAIN WITH LOCALLY
HIGHER AMOUNTS POSSIBLE. ITS ALWAYS TOUGH TO PINPOINT WHERE THE
HEAVIEST AXIS OF RAIN WILL SETUP IN THESE SITUATIONS. IT DOES LOOK
LIKE EASTERN MA/RHODE ISLAND IN THE STRONGEST LIFT AND STAND THE BEST
CHANCE OF SEEING THE HEAVIEST RAIN. WE WILL HAVE TO BE CONCERNED WITH
URBAN AND POOR DRAINAGE STREET FLOODING SO THE FLOOD WATCH CONTINUES.
INDICES ARE MARGINAL...BUT WILL INCLUDE A SLIGHT CHANCE OF THUNDER
THIS AFTERNOON BUT NOTHING WIDESPREAD IS EXPECTED.
AS FOR HIGH TEMPERATURES...SINCE WE SHOULD ENTER THE WARM SECTOR
EXPECT THEM TO REACH MAINLY INTO THE LOWER 70S. DEWPOINTS WILL BE
MUCH HIGHER THAN YESTERDAY SO IT WILL FEEL MUGGY.
IN ADDITION...THE HIGH SURF ADVISORY CONTINUES TODAY FOR HIGH SURF
AND DANGEROUS RIP CURRENTS ACROSS THE SOUTH COAST...CAPE AND ISLANDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
POSSIBLE PRE EVENT.
THE BAND OF HEAVY RAIN SHOULD BEGIN TO LIFT TO OUR NORTH EARLY IN
THE EVENING. IT LOOKS LIKE WE MAY ENTER ANOTHER LULL IN THE
ACTIVITY AS THE STEADY PRECIPITATION EXITS OUR REGION.
HOWEVER...THE ATMOSPHERE WILL REMAIN JUICED SO SCATTERED SHOWERS MAY
POPUP JUST ABOUT ANYWHERE ALONG WITH FOG PATCHES. LOW TEMPERATURES
SHOULD REMAIN MILD WITH CLOUD COVER AND HIGH DEWPOINTS IN PLACE.
EXPECT LOWS TO RANGE FROM BETWEEN 60 AND 65.
SUNDAY...
A HIGHLY UNCERTAIN AND LOW CONFIDENCE FORECAST EXISTS SUNDAY MORNING
INTO THE EARLY AFTERNOON. WE WILL BE WATCHING TROPICAL STORM KYLE
WHICH ALL MODELS HAVE PASSING 50 TO 80 MILES EAST OF THE CAPE AND
ISLANDS. LATEST HURRICANE HUNTER AIRCRAFT MEASUREMENTS ARE THAT ALL
THE WINDS ARE ON THE EAST SIDE OF THE STORM. THIS IS OFTEN THE CASE
WHEN TROPICAL SYSTEMS EVENTUALLY MAKE IT UP TO OUR LATITUDE.
THERE IS CONSIDERABLE DIFFERENCES IN THE 00Z SUITE OF MODEL DATA
AND IMPACTS ACROSS OUR REGION. THE 00Z GFS/CANADIAN MODELS ARE THE
MOST AGGRESSIVE AND EVENTUALLY TRIES TO WRAP IN SOME STRONG WINDS ON
THE WEST SIDE OF THE STORM. THESE MODELS SHOW THE POTENTIAL FOR
TROPICAL STORM FORCE WIND GUSTS ACROSS THE OUTER-CAPE AND
NANTUCKET. HOWEVER...THE UKMET/NAM ARE A BIT FURTHER EAST AND MUCH
WEAKER ON THE WEST SIDE OF THE SYSTEM. THIS WOULD MEAN NOT MUCH
WIND FOR ANY OF OUR REGION. THE LATEST ECMWF MODEL IS SOMEWHAT IN
BETWEEN BUT DOES SHOW THE POTENTIAL FOR SOME BRIEF TROPICAL STORM
WINDS ACROSS THE OUTER-CAPE AND NANTUCKET.
ALL IN ALL...IF KYLE IS ABLE TO FORM WINDS ON THE WESTERN SIDE OF
THE STORM LIKE SOME OF THE MODELS HINT AT...WE COULD SEE A FEW HOURS
OF TROPICAL STORM FORCE WIND GUSTS ON THE OUTER-CAPE AND NANTUCKET.
WILL HAVE TO SEE WHAT THE 12Z MODELS SHOW AND IF THEY TRACK THE
SYSTEM A BIT CLOSER OR FARTHER FROM THE COAST.
AS FOR THE RAIN...WE MAY SEE SEVERAL HOURS OF HEAVY RAIN ALONG THE
COAST DEPENDING ON THE TRACK OF THE SYSTEM. HOWEVER...WE DO NOT
EXPECT THE STEADY RAIN TO MAKE IT THAT FAR INLAND ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
GOOD MODEL AGREEMENT EARLY THIS PERIOD WITH KYLE EXITING THE EASTERN
NEW ENGLAND WATERS SUNDAY EVENING. HOWEVER...A CHANCE OF SHOWERS
WILL LINGER SUN NIGHT AND INTO EARLY MON...AS MID LEVEL TROF AND
ASSOCIATED SURFACE COLD FRONT MOVE ACROSS THE REGION DURING THIS
TIME. BY MON AFTERNOON GOOD MODEL AGREEMENT THAT MEAN TROF AXIS AND
ASSOCIATED DEEP LAYER MOISTURE WILL BE OFFSHORE. THUS...DRY WEATHER
SHOULD RETURN TO THE REGION MON AFTERNOON. THIS DRY WEATHER AND
SEASONABLE TEMPS SHOULD LINGER INTO TUE AS SHORT WAVE RIDGING
DEVELOPS OVER THE REGION AHEAD OF NEXT TROF ENTERING THE GREAT
LAKES.
00Z MODEL GUIDANCE IN GOOD AGREEMENT THAT THE ARRIVAL OF OCTOBER
WILL BE ACCOMPANIED BY A HIGHLY AMPLIFIED PATTERN MID TO LATE NEXT
WEEK...WITH A LONG WAVE TROF SETTING UP ACROSS THE NORTHEAST. GOOD
MODEL AGREEMENT ON THE TIMING OF THE LEAD SHORT WAVE AND ASSOCIATED
COLD FRONT TO ARRIVE HERE IN THE TUE NIGHT - WED TIME FRAME.
THEREFORE...ABOVE AVERAGE CONFIDENCE ON A CHANCE OF SHOWERS HERE TUE
NIGHT INTO WED. THEREAFTER...MODELS DISAGREE ON THE TIMING AND
AMPLITUDE OF THE NEXT SHORT WAVE ROTATING THROUGH THE NORTHEAST
MEAN MID LEVEL TROF. HOWEVER THE OVERALL LARGE SCALE FLOW ACROSS NEW
ENGLAND THU AND FRI WILL BE A COOL AND UNSTABLE CYCLONIC FLOW. SO
EXPECTING MAINLY DRY WEATHER THU AND FRI WITH ISOLATED DIURNAL SHOWER
GIVEN COLD AIR ALOFT WITH MID LEVEL TROF OVERHEAD. COOLER THAN
NORMAL TEMPS EXPECTED AS BOTH 00Z GFS/ECMWF AND 00Z ENSEMBLES
SUGGEST 850 TEMPS COOLING TO ABOUT +4C THU AND THEN DOWN TO +2C FRI!
THEREFORE THE HIGHER TERRAIN MAY ONLY SEE HIGHS FRI IN THE 50S!
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
IFR IN WEAK NLY FLOW EXCPT BECOMING OCNLY VFR PVD HYA AND ACK TDY IN
SHOWERY SE FLOW.
OTRW IFR CONDITIONS WILL BE THE RULE AT ALL SOUTHERN NEW ENGLAND
TERMINALS TODAY...TONIGHT...AND POSSIBLY THROUGH SUNDAY AS MOIST
TROPICAL AIR CONTINUES TO BE TRANSPORTED ONSHORE. THERE WILL BE
PERIODS OF HEAVY RAIN...MOST LIKELY BETWEEN 18Z AND 00Z TODAY. SLIGHT
CHANCE OF A BRIEF TSTM DURING THIS PERIOD. THE RAIN WILL LIKELY
BECOME LIGHTER AFTER 00Z AT MOST TERMINALS BUT CIGS WILL REMAIN
DOWN. FOR SUNDAY...IT/S POSSIBLE THAT AN IMPROVEMENT IN CIGS/VSBYS
WILL BE SEEN DEPENDING ON HOW FAST SOME DRYING CAN OCCUR. RIGHT NOW
IT LOOKS LIKE AT LEAST IFR IN THE MORNING. TROPICAL STORM KYLE LOOKS
TO PASS FAR ENOUGH EAST OF CAPE COD TO LIMIT EFFECTS TO THE
MAINLAND...BUT SOME GUSTY NORTHERLY WINDS COULD OCCUR ON THE CAPE
AND ISLANDS SOMETIME ON SUNDAY AS IT MAKES IT/S CLOSEST APPROACH.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT...IFR CIGS LIKELY. SCATTERED SHOWERS.
MONDAY...IFR/MVFR CIGS IN THE MORNING SHOULD LIFT TO A BKN DECK OF
MVFR/VFR. SCATTERED SHOWERS EARLY BOS-PVD-HYA-ACK.
TUESDAY...VFR WITH MVFR IN SCATTERED SHOWERS POSSIBLE LATE TUE NIGHT.
WEDNESDAY...MVFR IN SCATTERED SHOWERS.
&&
.MARINE...
THIS AFTERNOON...
11 AM CWF FCST HAS ADJUSTED SEAS WINDS AND HEADLINES FOR SUNDAY...MAINLY
CAPE COD CANAL WATERS EAST TO 15 MILES EAST OF GLOUCESTER MASS.
OTRW SCA FOR SEAS WILL CONTINUE FOR OUR OUTER-WATERS AND SOUNDS WITH
PERSISTENT ONSHORE FLOW THIS AFTN AND EVENING. IN ADDITION...WE WILL
LIKELY SEE A PERIOD OF SCA WINDS GUSTS FOR MUCH OF OUR SOUTHERN
WATERS LATER THIS AFTERNOON INTO EARLY EVENING. THIS ASSOCIATED WITH
THE NEXT PIECE OF SHORTWAVE ENERGY. THEREFORE...WILL HAVE SCA FOR ALL
WATERS EXCEPT BOSTON HARBOR...CAPE COD AND NARR BAYS.
TONIGHT...
WINDS SHOULD TEMPORARILY DIMINISH BUT SEAS WILL REMAIN WELL ABOVE
SCA THRESHOLDS ACROSS THE OPEN WATERS...SO WILL CONTINUE HEADLINES.
SUNDAY...
A HIGHLY UNCERTAIN FORECAST OVER THE WATERS. KYLE LOOKS TO PASS EAST
OF THE CAPE AND ISLANDS. THEREFORE...THE EXACT TRACK AND HOW STRONG
THE WESTERN SIDE OF KYLE GETS WILL DETERMINE HOW STRONG THE WINDS.
IF ITS ABLE TO STRENGTHEN ENOUGH WE COULD HAVE A FEW HOURS OF TROPICAL
STORM FORCE WINDS AND HIGH SEAS OVER OUR SOUTHEAST WATERS. CONFIDENCE
REMAINS LOW. ATTM AN 11AM TROP STORM WATCH ISSUED FOR THE REGION WHERE
SUSTAINED 34 KT POSSIBLE AND GALE WATCH ADJACENT TO THAT FOR GALE GUSTS
IS ASSN WITH THE NEARBY PASSAGE OF DEVELOPING KYLE.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT...KYLE SHOULD BE OVER GEORGES BANK OR GULF OF
ME...TRACKING TOWARD NOVA SCOTIA.
MONDAY AND TUE...FAIRLY LIGHT WINDS AND SUBSIDING SEAS EXPECTED.
WED...SOUTH WINDS WILL INCREASE AS COLD FRONT APPROACHES FROM THE
WEST. SCATTERED SHOWERS EXPECTED. MODEST NW WIND POSSIBLE LATE WED
NIGHT BEHIND COLD FRONT.
&&
.HYDROLOGY...
FOR STORM TOTALS...WE WILL CONTINUE TO ADD THE TWO OR THREE SEGMENT
EVENT...DESPITE THE 12-15 HOUR BREAK THAT HAS OCCURRED. THIS MAKES
BOOKKEEPING EASIER FOR THE FRI-SUN EVENT AND WE WILL ELABORATE IN
SUBSEQUENT PNS`S REGARDING THE VALUED RECOVERY PERIOD AS RUNOFF FLOWS
OUT THE SYSTEM ALLOWING FOR RENEWED R+ ON OUR DOORSTEP.
A LONG LULL IN THE ACTIVITY OCCURRED OVERNIGHT. HOWEVER...ANOTHER
STRONG BURST OF LIFT WILL COINCIDE WITH HIGH PWAT VALUES TO PRODUCE
MORE HEAVY RAIN...LATER THIS MORNING AND AFTERNOON. AN ADDITIONAL 1
TO 3 INCHES OF RAIN WITH LOCALLY HIGHER AMOUNTS ARE EXPECTED. THE
MODELS ARE PINNING RHODE ISLAND AND EASTERN MA FOR GETTING THE HEAVIEST
RAIN THIS AFTERNOON/EVENING. THIS MAY LEAD TO SOME URBAN AND POOR
DRAINAGE STREET FLOODING. THE HEAVIEST RAIN SHOULD LIFT OFF TO THE
NORTH OF OUR REGION THIS EVENING. WE MAY END UP IN A LULL AGAIN FOR
MUCH OF TONIGHT WITH JUST SCATTERED SHOWERS. TROPICAL STORM KYLE
COULD THROW BACK A PERIOD OF HEAVY RAIN ALONG THE IMMEDIATE COAST ON
SUNDAY...BUT RAINFALL AMOUNTS SHOULD QUICKLY DIMINISH ACROSS THE
INTERIOR.
WITH ALL THAT SAID...THE POTENTIAL EXISTS FOR SEVERAL RIVER FORECAST
POINTS TO EXPERIENCE MINOR FLOODING. AREAS OF CONCERN INCLUDE MAIN
TRIBUTARIES TO THE LOWER MERRIMACK RIVER...AS WELL AS PORTIONS OF
THE MAINSTEM MERRIMACK ITSELF. ALSO IN SOUTH CENTRAL MA AND RI...THE
BLACKSTONE RIVER...AND THE PAWTUXET. IN CENTRAL CONNECTICUT THE
FARMINGTON RIVER COULD EXPERIENCE STRONG RISES AS WELL. THERE IS A
CHANCE THESE TRIBUTARIES COULD REACH FLOOD STAGE TONIGHT OR SUNDAY...STAY
TUNED FOR UPDATES. THE PAWTUXET RIVER COULD EXPERIENCE PROBLEMS
EARLIER SINCE IT RESPONDS VERY QUICKLY TO HEAVY RAINS. TO ACQUIRE
SPECIFIC RIVER STAGE FORECASTS GO TO WEATHER.GOV/BOSTON...CLICK ON
RIVERS AND LAKES AHPS...AND CLICK ON THE FORECAST POINT OF CONCERN.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH SUNDAY MORNING FOR CTZ002>004.
MA...HIGH SURF ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR MAZ020-
022>024.
FLOOD WATCH THROUGH SUNDAY MORNING FOR MAZ002>021-026.
NH...FLOOD WATCH THROUGH SUNDAY MORNING FOR NHZ011-012-015.
RI...HIGH SURF ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR
RIZ006>008.
FLOOD WATCH THROUGH SUNDAY MORNING FOR RIZ001>007.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR ANZ235-
237-255.
TROPICAL STORM WATCH FOR ANZ250-254.
&&
$$
SYNOPSIS...NOCERA 1130A
NEAR TERM...FRANK 1130A
SHORT TERM...FRANK 1130A
LONG TERM...NOCERA
AVIATION...NOCERA/EKSTER 1130A
MARINE...NOCERA/FRANK 1130A
HYDROLOGY...FRANK/DRAG 1130A
AREA FORECAST DISCUSSION
NWS TAUNTON MA
938 AM EDT SAT SEP 27 2008
.SYNOPSIS...
LOW PRESSURE OVER THE MID ATLANTIC STATES COMBINED WITH THE BERMUDA
HIGH CONTINUES A TROPICAL CONVEYOR BELT OF MOISTURE INTO SOUTHERN
NEW ENGLAND...YIELDING A PERIOD OF VERY HEAVY RAIN THIS AFTERNOON
OR TONIGHT AS PRECURSOR EVENT TO THE NEARBY PASSAGE OF TROPICAL STORM
KYLE. KYLE IS EXPECTED TO PASS EAST OF NEW ENGLAND SUNDAY...POSSIBLY
BRINGING A PERIOD OF STRONG WINDS AND HEAVY RAIN TO CAPE COD NANTUCKET
AND THE OUTER MASSACHUSETTS COASTAL WATERS. FOR THE LATEST INFORMATION ON
KYLE...VISIT THE NATIONAL HURRICANE CENTER WEBSITE FOR DETAILS. DRY
AND SEASONABLE WEATHER WILL RETURN EARLY NEXT WEEK...WITH THE NEXT
CHANCE OF RAIN ARRIVING AROUND MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MODEL FEEL IS NOT GOOD THIS MORNING... ALL MODELS TENDING TO
STRUGGLE AT 930AM ANALYSIS. WE ARE GOING TO WING IT A BIT WITH TPC
GUIDANCE ON KYLE ITSELF. WE MAY BE HEADED FOR A PRE EVENT TONIGHT
ALONG THE I 95 CORRIDOR.
NOT MUCH RAIN FELL ACROSS THE REGION OVERNIGHT WITH A LONG LULL IN
THE ACTIVITY. AS IS TYPICALLY THE CASE...ONCE WE ENTERED THE WARM
SECTOR THE PRECIPITATION SHIELD BECAME SHOWERY IN NATURE AND THE
MODELS TEND TO STRUGGLE WHERE AND WHEN IT WILL OCCUR.
NONETHELESS...MODELS INDICATE THAT ANOTHER GOOD PULSE OF HEAVY RAIN
WILL BE MOVING INTO THE REGION LATER THIS MORNING AND AFTERNOON.
THERE IS ANOTHER GOOD SHORTWAVE EMBEDDED IN MERIDIONAL FLOW WHICH
WILL INTERACT WITH AN INVERTED TROUGH. THE GFS HAS VERY INTENSE
LIFT MOVING NORTHWARD ACROSS THE REGION THIS AFTERNOON. THIS
COMBINED WITH PWATS OVER 2 INCHES HAVE THE INGREDIENTS FOR MORE
HEAVY RAIN. RADAR IMAGERY ALSO SHOWS THE BEGINNING OF THIS ACTIVITY
OFF THE MID ATLANTIC COAST. THEREFORE...WILL BRING POPS BACKUP TO
CATEGORICAL LATER THIS MORNING AND AFTERNOON. RAINFALL AMOUNTS MAY
VARY CONSIDERABLY ACROSS THE REGION SINCE WE WILL BE ENTERING THE
WARM SECTOR AND THE PRECIPITATION WILL BE MORE SHOWERY. HOWEVER...WITH
INTENSE FORCING AND HIGH PWATS POCKETS OF TORRENTIAL RAINFALL ARE
EXPECTED. WE EXPECT AN ADDITIONAL 1 TO 3 INCHES OF RAIN WITH LOCALLY
HIGHER AMOUNTS POSSIBLE. ITS ALWAYS TOUGH TO PINPOINT WHERE THE
HEAVIEST AXIS OF RAIN WILL SETUP IN THESE SITUATIONS. IT DOES LOOK
LIKE EASTERN MA/RHODE ISLAND IN THE STRONGEST LIFT AND STAND THE BEST
CHANCE OF SEEING THE HEAVIEST RAIN. WE WILL HAVE TO BE CONCERNED WITH
URBAN AND POOR DRAINAGE STREET FLOODING SO THE FLOOD WATCH CONTINUES.
INDICES ARE MARGINAL...BUT WILL INCLUDE A SLIGHT CHANCE OF THUNDER
THIS AFTERNOON BUT NOTHING WIDESPREAD IS EXPECTED.
AS FOR HIGH TEMPERATURES...SINCE WE SHOULD ENTER THE WARM SECTOR
EXPECT THEM TO REACH MAINLY INTO THE LOWER 70S. DEWPOINTS WILL BE
MUCH HIGHER THAN YESTERDAY SO IT WILL FEEL MUGGY.
IN ADDITION...THE HIGH SURF ADVISORY CONTINUES TODAY FOR HIGH SURF
AND DANGEROUS RIP CURRENTS ACROSS THE SOUTH COAST...CAPE AND ISLANDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
POSSIBLE PRE EVENT.
THE BAND OF HEAVY RAIN SHOULD BEGIN TO LIFT TO OUR NORTH EARLY IN
THE EVENING. IT LOOKS LIKE WE MAY ENTER ANOTHER LULL IN THE
ACTIVITY AS THE STEADY PRECIPITATION EXITS OUR REGION.
HOWEVER...THE ATMOSPHERE WILL REMAIN JUICED SO SCATTERED SHOWERS MAY
POPUP JUST ABOUT ANYWHERE ALONG WITH FOG PATCHES. LOW TEMPERATURES
SHOULD REMAIN MILD WITH CLOUD COVER AND HIGH DEWPOINTS IN PLACE.
EXPECT LOWS TO RANGE FROM BETWEEN 60 AND 65.
SUNDAY...
A HIGHLY UNCERTAIN AND LOW CONFIDENCE FORECAST EXISTS SUNDAY MORNING
INTO THE EARLY AFTERNOON. WE WILL BE WATCHING TROPICAL STORM KYLE
WHICH ALL MODELS HAVE PASSING 50 TO 80 MILES EAST OF THE CAPE AND
ISLANDS. LATEST HURRICANE HUNTER AIRCRAFT MEASUREMENTS ARE THAT ALL
THE WINDS ARE ON THE EAST SIDE OF THE STORM. THIS IS OFTEN THE CASE
WHEN TROPICAL SYSTEMS EVENTUALLY MAKE IT UP TO OUR LATITUDE.
THERE IS CONSIDERABLE DIFFERENCES IN THE 00Z SUITE OF MODEL DATA
AND IMPACTS ACROSS OUR REGION. THE 00Z GFS/CANADIAN MODELS ARE THE
MOST AGGRESSIVE AND EVENTUALLY TRIES TO WRAP IN SOME STRONG WINDS ON
THE WEST SIDE OF THE STORM. THESE MODELS SHOW THE POTENTIAL FOR
TROPICAL STORM FORCE WIND GUSTS ACROSS THE OUTER-CAPE AND
NANTUCKET. HOWEVER...THE UKMET/NAM ARE A BIT FURTHER EAST AND MUCH
WEAKER ON THE WEST SIDE OF THE SYSTEM. THIS WOULD MEAN NOT MUCH
WIND FOR ANY OF OUR REGION. THE LATEST ECMWF MODEL IS SOMEWHAT IN
BETWEEN BUT DOES SHOW THE POTENTIAL FOR SOME BRIEF TROPICAL STORM
WINDS ACROSS THE OUTER-CAPE AND NANTUCKET.
ALL IN ALL...IF KYLE IS ABLE TO FORM WINDS ON THE WESTERN SIDE OF
THE STORM LIKE SOME OF THE MODELS HINT AT...WE COULD SEE A FEW HOURS
OF TROPICAL STORM FORCE WIND GUSTS ON THE OUTER-CAPE AND NANTUCKET.
WILL HAVE TO SEE WHAT THE 12Z MODELS SHOW AND IF THEY TRACK THE
SYSTEM A BIT CLOSER OR FARTHER FROM THE COAST.
AS FOR THE RAIN...WE MAY SEE SEVERAL HOURS OF HEAVY RAIN ALONG THE
COAST DEPENDING ON THE TRACK OF THE SYSTEM. HOWEVER...WE DO NOT
EXPECT THE STEADY RAIN TO MAKE IT THAT FAR INLAND ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
GOOD MODEL AGREEMENT EARLY THIS PERIOD WITH KYLE EXITING THE EASTERN
NEW ENGLAND WATERS SUNDAY EVENING. HOWEVER...A CHANCE OF SHOWERS
WILL LINGER SUN NIGHT AND INTO EARLY MON...AS MID LEVEL TROF AND
ASSOCIATED SURFACE COLD FRONT MOVE ACROSS THE REGION DURING THIS
TIME. BY MON AFTERNOON GOOD MODEL AGREEMENT THAT MEAN TROF AXIS AND
ASSOCIATED DEEP LAYER MOISTURE WILL BE OFFSHORE. THUS...DRY WEATHER
SHOULD RETURN TO THE REGION MON AFTERNOON. THIS DRY WEATHER AND
SEASONABLE TEMPS SHOULD LINGER INTO TUE AS SHORT WAVE RIDGING
DEVELOPS OVER THE REGION AHEAD OF NEXT TROF ENTERING THE GREAT
LAKES.
00Z MODEL GUIDANCE IN GOOD AGREEMENT THAT THE ARRIVAL OF OCTOBER
WILL BE ACCOMPANIED BY A HIGHLY AMPLIFIED PATTERN MID TO LATE NEXT
WEEK...WITH A LONG WAVE TROF SETTING UP ACROSS THE NORTHEAST. GOOD
MODEL AGREEMENT ON THE TIMING OF THE LEAD SHORT WAVE AND ASSOCIATED
COLD FRONT TO ARRIVE HERE IN THE TUE NIGHT - WED TIME FRAME.
THEREFORE...ABOVE AVERAGE CONFIDENCE ON A CHANCE OF SHOWERS HERE TUE
NIGHT INTO WED. THEREAFTER...MODELS DISAGREE ON THE TIMING AND
AMPLITUDE OF THE NEXT SHORT WAVE ROTATING THROUGH THE NORTHEAST
MEAN MID LEVEL TROF. HOWEVER THE OVERALL LARGE SCALE FLOW ACROSS NEW
ENGLAND THU AND FRI WILL BE A COOL AND UNSTABLE CYCLONIC FLOW. SO
EXPECTING MAINLY DRY WEATHER THU AND FRI WITH ISOLATED DIURNAL SHOWER
GIVEN COLD AIR ALOFT WITH MID LEVEL TROF OVERHEAD. COOLER THAN
NORMAL TEMPS EXPECTED AS BOTH 00Z GFS/ECMWF AND 00Z ENSEMBLES
SUGGEST 850 TEMPS COOLING TO ABOUT +4C THU AND THEN DOWN TO +2C FRI!
THEREFORE THE HIGHER TERRAIN MAY ONLY SEE HIGHS FRI IN THE 50S!
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
IFR IN WEAK NLY FLOW EXCPT BECOMING OCNLY VFR PVD HYA AND ACK TDY IN
SHOWERY SE FLOW.
OTRW IFR CONDITIONS WILL BE THE RULE AT ALL SOUTHERN NEW ENGLAND
TERMINALS TODAY...TONIGHT...AND POSSIBLY THROUGH SUNDAY AS MOIST
TROPICAL AIR CONTINUES TO BE TRANSPORTED ONSHORE. THERE WILL BE
PERIODS OF HEAVY RAIN...MOST LIKELY BETWEEN 18Z AND 00Z TODAY. SLIGHT
CHANCE OF A BRIEF TSTM DURING THIS PERIOD. THE RAIN WILL LIKELY
BECOME LIGHTER AFTER 00Z AT MOST TERMINALS BUT CIGS WILL REMAIN
DOWN. FOR SUNDAY...IT/S POSSIBLE THAT AN IMPROVEMENT IN CIGS/VSBYS
WILL BE SEEN DEPENDING ON HOW FAST SOME DRYING CAN OCCUR. RIGHT NOW
IT LOOKS LIKE AT LEAST IFR IN THE MORNING. TROPICAL STORM KYLE LOOKS
TO PASS FAR ENOUGH EAST OF CAPE COD TO LIMIT EFFECTS TO THE
MAINLAND...BUT SOME GUSTY NORTHERLY WINDS COULD OCCUR ON THE CAPE
AND ISLANDS SOMETIME ON SUNDAY AS IT MAKES IT/S CLOSEST APPROACH.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT...IFR CIGS LIKELY. SCATTERED SHOWERS.
MONDAY...IFR/MVFR CIGS IN THE MORNING SHOULD LIFT TO A BKN DECK OF
MVFR/VFR. SCATTERED SHOWERS EARLY BOS-PVD-HYA-ACK.
TUESDAY...VFR WITH MVFR IN SCATTERED SHOWERS POSSIBLE LATE TUE NIGHT.
WEDNESDAY...MVFR IN SCATTERED SHOWERS.
&&
.MARINE...
TODAY...
PLEASE MONITOR THE 11 AM FCST FOR ADJUSTMENTS IN SEAS AND WINDS VCNTY
ACK NORTHWARD THRU CC BAY TO 15 MILES EAST OF CAPE ANN MASS ON SUNDAY.
SCA FOR SEAS WILL CONTINUE FOR OUR OUTER-WATERS AND SOUNDS WITH
PERSISTENT ONSHORE FLOW. IN ADDITION...WE WILL LIKELY SEE A PERIOD OF
SCA WINDS GUSTS FOR MUCH OF OUR SOUTHERN WATERS THIS AFTERNOON INTO
EARLY EVENING. THIS ASSOCIATED WITH THE NEXT PIECE OF SHORTWAVE
ENERGY. THEREFORE...WILL HAVE SCA FOR ALL WATERS EXCEPT BOSTON
HARBOR...CAPE COD AND NARR BAYS.
TONIGHT...
WINDS SHOULD TEMPORARILY DIMINISH BUT SEAS WILL REMAIN WELL ABOVE
SCA THRESHOLDS ACROSS THE OPEN WATERS...SO WILL CONTINUE HEADLINES.
SUNDAY...
A HIGHLY UNCERTAIN FORECAST OVER THE WATERS. KYLE LOOKS TO PASS
EAST OF THE CAPE AND ISLANDS. THEREFORE...THE EXACT TRACK AND HOW
STRONG THE WESTERN SIDE OF KYLE GETS WILL DETERMINE HOW STRONG THE
WINDS GET. IF ITS ABLE TO STRENGTHEN ENOUGH WE COULD HAVE A FEW
HOURS OF TROPICAL STORM FORCE WIND GUSTS AND HIGH SEAS OVER OUR
SOUTHEAST WATERS. CONFIDENCE REMAINS LOW THROUGH.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT...KYLE SHOULD BE OVER GEORGES BANK OR GULF OF
ME...TRACKING TOWARD NOVA SCOTIA.
MONDAY AND TUE...FAIRLY LIGHT WINDS AND SUBSIDING SEAS EXPECTED.
WED...SOUTH WINDS WILL INCREASE AS COLD FRONT APPROACHES FROM THE
WEST. SCATTERED SHOWERS EXPECTED. MODEST NW WIND POSSIBLE LATE WED
NIGHT BEHIND COLD FRONT.
&&
.HYDROLOGY...
FOR STORM TOTALS...WE WILL CONTINUE TO ADD THE TWO OR THREE SEGMENT
EVENT...DESPITE THE 12-15 HOUR BREAK THAT HAS OCCURRED. THIS MAKES
BOOKKEEPING EASIER FOR THE FRI-SUN EVENT AND WE WILL ELABORATE IN
SUBSEQUENT PNS`S REGARDING THE VALUED RECOVERY PERIOD AS RUNOFF FLOWS
OUT THE SYSTEM ALLOWING FOR RENEWED R+ ON OUR DOORSTEP.
A LONG LULL IN THE ACTIVITY OCCURRED OVERNIGHT. HOWEVER...ANOTHER
STRONG BURST OF LIFT WILL COINCIDE WITH HIGH PWAT VALUES TO PRODUCE
MORE HEAVY RAIN...LATER THIS MORNING AND AFTERNOON. AN ADDITIONAL 1
TO 3 INCHES OF RAIN WITH LOCALLY HIGHER AMOUNTS ARE EXPECTED. THE
MODELS ARE PINNING RHODE ISLAND AND EASTERN MA FOR GETTING THE HEAVIEST
RAIN THIS AFTERNOON/EVENING. THIS MAY LEAD TO SOME URBAN AND POOR
DRAINAGE STREET FLOODING. THE HEAVIEST RAIN SHOULD LIFT OFF TO THE
NORTH OF OUR REGION THIS EVENING. WE MAY END UP IN A LULL AGAIN FOR
MUCH OF TONIGHT WITH JUST SCATTERED SHOWERS. TROPICAL STORM KYLE
COULD THROW BACK A PERIOD OF HEAVY RAIN ALONG THE IMMEDIATE COAST ON
SUNDAY...BUT RAINFALL AMOUNTS SHOULD QUICKLY DIMINISH ACROSS THE
INTERIOR.
WITH ALL THAT SAID...THE POTENTIAL EXISTS FOR SEVERAL RIVER FORECAST
POINTS TO EXPERIENCE MINOR FLOODING. AREAS OF CONCERN INCLUDE MAIN
TRIBUTARIES TO THE LOWER MERRIMACK RIVER...AS WELL AS PORTIONS OF
THE MAINSTEM MERRIMACK ITSELF. ALSO IN SOUTH CENTRAL MA AND RI...THE
BLACKSTONE RIVER...AND THE PAWTUXET. IN CENTRAL CONNECTICUT THE
FARMINGTON RIVER COULD EXPERIENCE STRONG RISES AS WELL. THERE IS A
CHANCE THESE TRIBUTARIES COULD REACH FLOOD STAGE TONIGHT OR SUNDAY...STAY
TUNED FOR UPDATES. THE PAWTUXET RIVER COULD EXPERIENCE PROBLEMS
EARLIER SINCE IT RESPONDS VERY QUICKLY TO HEAVY RAINS. TO ACQUIRE
SPECIFIC RIVER STAGE FORECASTS GO TO WEATHER.GOV/BOSTON...CLICK ON
RIVERS AND LAKES AHPS...AND CLICK ON THE FORECAST POINT OF CONCERN.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH SUNDAY MORNING FOR CTZ002>004.
MA...FLOOD WATCH THROUGH SUNDAY MORNING FOR MAZ002>021-026.
HIGH SURF ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR MAZ020-
022>024.
NH...FLOOD WATCH THROUGH SUNDAY MORNING FOR NHZ011-012-015.
RI...FLOOD WATCH THROUGH SUNDAY MORNING FOR RIZ001>007.
HIGH SURF ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR
RIZ006>008.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR
ANZ232>235-237-250-254-255.
&&
$$
SYNOPSIS...NOCERA/DRAG 939A
NEAR TERM...FRANK/DRAG 939A
SHORT TERM...FRANK
LONG TERM...NOCERA
AVIATION...NOCERA/EKSTER/DRAG 939A
MARINE...NOCERA/FRANK 939A
HYDROLOGY...DRAG 751A
AREA FORECAST DISCUSSION
NWS TAUNTON MA
752 AM EDT SAT SEP 27 2008
.SYNOPSIS...
LOW PRESSURE OVER THE MID ATLANTIC STATES WILL COMBINE WITH THE
BERMUDA HIGH TO CONTINUE A TROPICAL CONVEYOR BELT OF MOISTURE INTO
SOUTHERN NEW ENGLAND TODAY...YIELDING A PERIOD OF VERY HEAVY RAIN
THIS AFTERNOON AND EARLY EVENING. TROPICAL STORM KYLE IS EXPECTED
TO PASS EAST OF NEW ENGLAND SUNDAY...POSSIBLY BRINGING A PERIOD OF
STRONG WINDS AND HEAVY RAIN TO CAPE COD AND NANTUCKET. FOR THE
LATEST INFORMATION ON KYLE...VISIT THE NATIONAL HURRICANE CENTER
WEBSITE FOR DETAILS. DRY AND SEASONABLE WEATHER WILL RETURN EARLY
NEXT WEEK...WITH THE NEXT CHANCE OF RAIN ARRIVING AROUND MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MODEL FEEL IS NOT GOOD THIS MORNING... ALL MODELS TENDING TO
STRUGGLE AT 750AM ANALYSIS. WE ARE GOING TO WING IT A BIT WITH TPC
GUIDANCE ON KYLE ITSELF.
NOT MUCH RAIN FELL ACROSS THE REGION OVERNIGHT WITH A LONG LULL IN
THE ACTIVITY. AS IS TYPICALLY THE CASE...ONCE WE ENTERED THE WARM
SECTOR THE PRECIPITATION SHIELD BECAME SHOWERY IN NATURE AND THE
MODELS TEND TO STRUGGLE WHERE AND WHEN IT WILL OCCUR.
NONETHELESS...MODELS INDICATE THAT ANOTHER GOOD PULSE OF HEAVY RAIN
WILL BE MOVING INTO THE REGION LATER THIS MORNING AND AFTERNOON.
THERE IS ANOTHER GOOD SHORTWAVE EMBEDDED IN MERIDIONAL FLOW WHICH
WILL INTERACT WITH AN INVERTED TROUGH. THE GFS HAS VERY INTENSE
LIFT MOVING NORTHWARD ACROSS THE REGION THIS AFTERNOON. THIS
COMBINED WITH PWATS OVER 2 INCHES HAVE THE INGREDIENTS FOR MORE
HEAVY RAIN. RADAR IMAGERY ALSO SHOWS THE BEGINNING OF THIS ACTIVITY
OFF THE MID ATLANTIC COAST. THEREFORE...WILL BRING POPS BACKUP TO
CATEGORICAL LATER THIS MORNING AND AFTERNOON. RAINFALL AMOUNTS MAY
VARY CONSIDERABLY ACROSS THE REGION SINCE WE WILL BE ENTERING THE
WARM SECTOR AND THE PRECIPITATION WILL BE MORE SHOWERY.
HOWEVER...WITH INTENSE FORCING AND HIGH PWATS POCKETS OF TORRENTIAL
RAINFALL ARE EXPECTED. WE EXPECT AN ADDITIONAL 1 TO 3 INCHES OF
RAIN WITH LOCALLY HIGHER AMOUNTS POSSIBLE. ITS ALWAYS TOUGH TO
PINPOINT WHERE THE HEAVIEST AXIS OF RAIN WILL SETUP IN THESE
SITUATIONS. IT DOES LOOK LIKE EASTERN MA/RHODE ISLAND IN THE
STRONGEST LIFT AND STAND THE BEST CHANCE OF SEEING THE HEAVIEST
RAIN. WE WILL HAVE TO BE CONCERNED WITH URBAN AND POOR DRAINAGE
STREET FLOODING SO THE FLOOD WATCH CONTINUES. INDICES ARE
MARGINAL...BUT WILL INCLUDE A SLIGHT CHANCE OF THUNDER THIS
AFTERNOON BUT NOTHING WIDESPREAD IS EXPECTED.
AS FOR HIGH TEMPERATURES...SINCE WE SHOULD ENTER THE WARM SECTOR
EXPECT THEM TO REACH MAINLY INTO THE LOWER 70S. DEWPOINTS WILL BE
MUCH HIGHER THAN YESTERDAY SO IT WILL FEEL MUGGY.
IN ADDITION...THE HIGH SURF ADVISORY CONTINUES TODAY FOR HIGH SURF
AND DANGEROUS RIP CURRENTS ACROSS THE SOUTH COAST...CAPE AND ISLANDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
THE BAND OF HEAVY RAIN SHOULD BEGIN TO LIFT TO OUR NORTH EARLY IN
THE EVENING. IT LOOKS LIKE WE MAY ENTER ANOTHER LULL IN THE
ACTIVITY AS THE STEADY PRECIPITATION EXITS OUR REGION.
HOWEVER...THE ATMOSPHERE WILL REMAIN JUICED SO SCATTERED SHOWERS MAY
POPUP JUST ABOUT ANYWHERE ALONG WITH FOG PATCHES. LOW TEMPERATURES
SHOULD REMAIN MILD WITH CLOUD COVER AND HIGH DEWPOINTS IN PLACE.
EXPECT LOWS TO RANGE FROM BETWEEN 60 AND 65.
SUNDAY...
A HIGHLY UNCERTAIN AND LOW CONFIDENCE FORECAST EXISTS SUNDAY MORNING
INTO THE EARLY AFTERNOON. WE WILL BE WATCHING TROPICAL STORM KYLE
WHICH ALL MODELS HAVE PASSING 50 TO 80 MILES EAST OF THE CAPE AND
ISLANDS. LATEST HURRICANE HUNTER AIRCRAFT MEASUREMENTS ARE THAT ALL
THE WINDS ARE ON THE EAST SIDE OF THE STORM. THIS IS OFTEN THE CASE
WHEN TROPICAL SYSTEMS EVENTUALLY MAKE IT UP TO OUR LATITUDE.
THERE IS CONSIDERABLE DIFFERENCES IN THE 00Z SUITE OF MODEL DATA
AND IMPACTS ACROSS OUR REGION. THE 00Z GFS/CANADIAN MODELS ARE THE
MOST AGGRESSIVE AND EVENTUALLY TRIES TO WRAP IN SOME STRONG WINDS ON
THE WEST SIDE OF THE STORM. THESE MODELS SHOW THE POTENTIAL FOR
TROPICAL STORM FORCE WIND GUSTS ACROSS THE OUTER-CAPE AND
NANTUCKET. HOWEVER...THE UKMET/NAM ARE A BIT FURTHER EAST AND MUCH
WEAKER ON THE WEST SIDE OF THE SYSTEM. THIS WOULD MEAN NOT MUCH
WIND FOR ANY OF OUR REGION. THE LATEST ECMWF MODEL IS SOMEWHAT IN
BETWEEN BUT DOES SHOW THE POTENTIAL FOR SOME BRIEF TROPICAL STORM
WINDS ACROSS THE OUTER-CAPE AND NANTUCKET.
ALL IN ALL...IF KYLE IS ABLE TO FORM WINDS ON THE WESTERN SIDE OF
THE STORM LIKE SOME OF THE MODELS HINT AT...WE COULD SEE A FEW HOURS
OF TROPICAL STORM FORCE WIND GUSTS ON THE OUTER-CAPE AND NANTUCKET.
WILL HAVE TO SEE WHAT THE 12Z MODELS SHOW AND IF THEY TRACK THE
SYSTEM A BIT CLOSER OR FARTHER FROM THE COAST.
AS FOR THE RAIN...WE MAY SEE SEVERAL HOURS OF HEAVY RAIN ALONG THE
COAST DEPENDING ON THE TRACK OF THE SYSTEM. HOWEVER...WE DO NOT
EXPECT THE STEADY RAIN TO MAKE IT THAT FAR INLAND ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
GOOD MODEL AGREEMENT EARLY THIS PERIOD WITH KYLE EXITING THE EASTERN
NEW ENGLAND WATERS SUNDAY EVENING. HOWEVER...A CHANCE OF SHOWERS
WILL LINGER SUN NIGHT AND INTO EARLY MON...AS MID LEVEL TROF AND
ASSOCIATED SURFACE COLD FRONT MOVE ACROSS THE REGION DURING THIS
TIME. BY MON AFTERNOON GOOD MODEL AGREEMENT THAT MEAN TROF AXIS AND
ASSOCIATED DEEP LAYER MOISTURE WILL BE OFFSHORE. THUS...DRY WEATHER
SHOULD RETURN TO THE REGION MON AFTERNOON. THIS DRY WEATHER AND
SEASONABLE TEMPS SHOULD LINGER INTO TUE AS SHORT WAVE RIDGING
DEVELOPS OVER THE REGION AHEAD OF NEXT TROF ENTERING THE GREAT
LAKES.
00Z MODEL GUIDANCE IN GOOD AGREEMENT THAT THE ARRIVAL OF OCTOBER
WILL BE ACCOMPANIED BY A HIGHLY AMPLIFIED PATTERN MID TO LATE NEXT
WEEK...WITH A LONG WAVE TROF SETTING UP ACROSS THE NORTHEAST. GOOD
MODEL AGREEMENT ON THE TIMING OF THE LEAD SHORT WAVE AND ASSOCIATED
COLD FRONT TO ARRIVE HERE IN THE TUE NIGHT - WED TIME FRAME.
THEREFORE...ABOVE AVERAGE CONFIDENCE ON A CHANCE OF SHOWERS HERE TUE
NIGHT INTO WED. THEREAFTER...MODELS DISAGREE ON THE TIMING AND
AMPLITUDE OF THE NEXT SHORT WAVE ROTATING THROUGH THE NORTHEAST
MEAN MID LEVEL TROF. HOWEVER THE OVERALL LARGE SCALE FLOW ACROSS NEW
ENGLAND THU AND FRI WILL BE A COOL AND UNSTABLE CYCLONIC FLOW. SO
EXPECTING MAINLY DRY WEATHER THU AND FRI WITH ISOLATED DIURNAL SHOWER
GIVEN COLD AIR ALOFT WITH MID LEVEL TROF OVERHEAD. COOLER THAN
NORMAL TEMPS EXPECTED AS BOTH 00Z GFS/ECMWF AND 00Z ENSEMBLES
SUGGEST 850 TEMPS COOLING TO ABOUT +4C THU AND THEN DOWN TO +2C FRI!
THEREFORE THE HIGHER TERRAIN MAY ONLY SEE HIGHS FRI IN THE 50S!
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
IFR CONDITIONS WILL BE THE RULE AT ALL SOUTHERN NEW ENGLAND
TERMINALS TODAY...TONIGHT...AND POSSIBLY THROUGH SUNDAY AS MOIST
TROPICAL AIR CONTINUES TO BE TRANSPORTED ONSHORE. THERE WILL BE
PERIODS OF HEAVY RAIN...MOST LIKELY BETWEEN 18Z AND 00Z TODAY. SLIGHT
CHANCE OF A BRIEF TSTM DURING THIS PERIOD. THE RAIN WILL LIKELY
BECOME LIGHTER AFTER 00Z AT MOST TERMINALS BUT CIGS WILL REMAIN
DOWN. FOR SUNDAY...IT/S POSSIBLE THAT AN IMPROVEMENT IN CIGS/VSBYS
WILL BE SEEN DEPENDING ON HOW FAST SOME DRYING CAN OCCUR. RIGHT NOW
IT LOOKS LIKE AT LEAST IFR IN THE MORNING. TROPICAL STORM KYLE LOOKS
TO PASS FAR ENOUGH EAST OF CAPE COD TO LIMIT EFFECTS TO THE
MAINLAND...BUT SOME GUSTY NORTHERLY WINDS COULD OCCUR ON THE CAPE
AND ISLANDS SOMETIME ON SUNDAY AS IT MAKES IT/S CLOSEST APPROACH.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT...IFR CIGS LIKELY. SCATTERED SHOWERS.
MONDAY...IFR/MVFR CIGS IN THE MORNING SHOULD LIFT TO A BKN DECK OF
MVFR/VFR. SCATTERED SHOWERS EARLY BOS-PVD-HYA-ACK.
TUESDAY...VFR WITH MVFR IN SCATTERED SHOWERS POSSIBLE LATE TUE NIGHT.
WEDNESDAY...MVFR IN SCATTERED SHOWERS.
&&
.MARINE...
TODAY...
SCA FOR SEAS WILL CONTINUE FOR OUR OUTER-WATERS AND SOUNDS WITH
PERSISTENT ONSHORE FLOW. IN ADDITION...WE WILL LIKELY SEE A PERIOD
OF SCA WINDS GUSTS FOR MUCH OF OUR SOUTHERN WATERS THIS AFTERNOON
INTO EARLY EVENING. THIS ASSOCIATED WITH THE NEXT PIECE OF
SHORTWAVE ENERGY. THEREFORE...WILL HAVE SCA FOR ALL WATERS EXCEPT
BOSTON HARBOR...CAPE COD AND NARR BAYS.
TONIGHT...
WINDS SHOULD TEMPORARILY DIMINISH BUT SEAS WILL REMAIN WELL ABOVE
SCA THRESHOLDS ACROSS THE OPEN WATERS...SO WILL CONTINUE HEADLINES.
SUNDAY...
A HIGHLY UNCERTAIN FORECAST OVER THE WATERS. KYLE LOOKS TO PASS
EAST OF THE CAPE AND ISLANDS. THEREFORE...THE EXACT TRACK AND HOW
STRONG THE WESTERN SIDE OF KYLE GETS WILL DETERMINE HOW STRONG THE
WINDS GET. IF ITS ABLE TO STRENGTHEN ENOUGH WE COULD HAVE A FEW
HOURS OF TROPICAL STORM FORCE WIND GUSTS AND HIGH SEAS OVER OUR
SOUTHEAST WATERS. CONFIDENCE REMAINS LOW THROUGH.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT...KYLE SHOULD BE OVER GEORGES BANK OR GULF OF
ME...TRACKING TOWARD NOVA SCOTIA.
MONDAY AND TUE...FAIRLY LIGHT WINDS AND SUBSIDING SEAS EXPECTED.
WED...SOUTH WINDS WILL INCREASE AS COLD FRONT APPROACHES FROM THE
WEST. SCATTERED SHOWERS EXPECTED. MODEST NW WIND POSSIBLE LATE WED
NIGHT BEHIND COLD FRONT.
&&
.HYDROLOGY...
FOR STORM TOTALS...WE WILL CONTINUE TO ADD THE TWO OR THREE SEGMENT
EVENT...DESPITE THE 12-15 HOUR BREAK THAT HAS OCCURRED. THIS MAKES
BOOKEEPEING EASIER FOR THE FRI-SUN EVENT AND WE WILL ELABORATE IN
SUBSEQUENT PNS`S REGARDING THE VALUED RECOVERY PERIOD AS RUNOFF FLOWS
OUT THE SYSTEM ALLOWING FOR RENEWED R+ ON OUR DOORSTEP.
A LONG LULL IN THE ACTIVITY OCCURRED OVERNIGHT. HOWEVER...ANOTHER
STRONG BURST OF LIFT WILL COINCIDE WITH HIGH PWAT VALUES TO PRODUCE
MORE HEAVY RAIN...LATER THIS MORNING AND AFTERNOON. AN ADDITIONAL 1
TO 3 INCHES OF RAIN WITH LOCALLY HIGHER AMOUNTS ARE EXPECTED. THE
MODELS ARE PINNING RHODE ISLAND AND EASTERN MA FOR GETTING THE HEAVIEST
RAIN THIS AFTERNOON/EVENING. THIS MAY LEAD TO SOME URBAN AND POOR
DRAINAGE STREET FLOODING. THE HEAVIEST RAIN SHOULD LIFT OFF TO THE
NORTH OF OUR REGION THIS EVENING. WE MAY END UP IN A LULL AGAIN FOR
MUCH OF TONIGHT WITH JUST SCATTERED SHOWERS. TROPICAL STORM KYLE
COULD THROW BACK A PERIOD OF HEAVY RAIN ALONG THE IMMEDIATE COAST ON
SUNDAY...BUT RAINFALL AMOUNTS SHOULD QUICKLY DIMINISH ACROSS THE
INTERIOR.
WITH ALL THAT SAID...THE POTENTIAL EXISTS FOR SEVERAL RIVER FORECAST
POINTS TO EXPERIENCE MINOR FLOODING. AREAS OF CONCERN INCLUDE MAIN
TRIBUTARIES TO THE LOWER MERRIMACK RIVER...AS WELL AS PORTIONS OF
THE MAINSTEM MERRIMACK ITSELF. ALSO IN SOUTH CENTRAL MA AND RI...THE
BLACKSTONE RIVER...AND THE PAWTUXET. IN CENTRAL CONNECTICUT THE
FARMINGTON RIVER COULD EXPERIENCE STRONG RISES AS WELL. THERE IS A
CHANCE THESE TRIBUTARIES COULD REACH FLOOD STAGE TONIGHT OR SUNDAY...STAY
TUNED FOR UPDATES. THE PAWTUXET RIVER COULD EXPERIENCE PROBLEMS
EARLIER SINCE IT RESPONDS VERY QUICKLY TO HEAVY RAINS. TO ACQUIRE
SPECIFIC RIVER STAGE FORECASTS GO TO WEATHER.GOV/BOSTON...CLICK ON
RIVERS AND LAKES AHPS...AND CLICK ON THE FORECAST POINT OF CONCERN.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH SUNDAY MORNING FOR CTZ002>004.
MA...FLOOD WATCH THROUGH SUNDAY MORNING FOR MAZ002>021-026.
HIGH SURF ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR MAZ020-
022>024.
NH...FLOOD WATCH THROUGH SUNDAY MORNING FOR NHZ011-012-015.
RI...FLOOD WATCH THROUGH SUNDAY MORNING FOR RIZ001>007.
HIGH SURF ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR
RIZ006>008.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR
ANZ232>235-237-250-254-255.
&&
$$
SYNOPSIS...NOCERA
NEAR TERM...FRANK 751 AM
SHORT TERM...FRANK
LONG TERM...NOCERA
AVIATION...NOCERA/EKSTER
MARINE...NOCERA/FRANK
HYDROLOGY...FRANK/DRAG 751 AM
AREA FORECAST DISCUSSION
NWS TAUNTON MA
435 AM EDT SAT SEP 27 2008
.SYNOPSIS...
LOW PRESSURE OVER THE MID ATLANTIC STATES WILL COMBINE WITH THE
BERMUDA HIGH TO CONTINUE A TROPICAL CONVEYOR BELT OF MOISTURE INTO
SOUTHERN NEW ENGLAND TODAY...YIELDING A PERIOD OF VERY HEAVY RAIN
THIS AFTERNOON AND EARLY EVENING. TROPICAL STORM KYLE IS EXPECTED
TO PASS EAST OF NEW ENGLAND SUNDAY...POSSIBLY BRINGING A PERIOD OF
STRONG WINDS AND HEAVY RAIN TO CAPE COD AND NANTUCKET. FOR THE
LATEST INFORMATION ON KYLE...VISIT THE NATIONAL HURRICANE CENTER
WEBSITE FOR DETAILS. DRY AND SEASONABLE WEATHER WILL RETURN EARLY
NEXT WEEK...WITH THE NEXT CHANCE OF RAIN ARRIVING AROUND MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NOT MUCH RAIN FELL ACROSS THE REGION OVERNIGHT WITH A LONG LULL IN
THE ACTIVITY. AS IS TYPICALLY THE CASE...ONCE WE ENTERED THE WARM
SECTOR THE PRECIPITATION SHIELD BECAME SHOWERY IN NATURE AND THE
MODELS TEND TO STRUGGLE WHERE AND WHEN IT WILL OCCUR.
NONETHELESS...MODELS INDICATE THAT ANOTHER GOOD PULSE OF HEAVY RAIN
WILL BE MOVING INTO THE REGION LATER THIS MORNING AND AFTERNOON.
THERE IS ANOTHER GOOD SHORTWAVE EMBEDDED IN MERIDIONAL FLOW WHICH
WILL INTERACT WITH AN INVERTED TROUGH. THE GFS HAS VERY INTENSE
LIFT MOVING NORTHWARD ACROSS THE REGION THIS AFTERNOON. THIS
COMBINED WITH PWATS OVER 2 INCHES HAVE THE INGREDIENTS FOR MORE
HEAVY RAIN. RADAR IMAGERY ALSO SHOWS THE BEGINNING OF THIS ACTIVITY
OFF THE MID ATLANTIC COAST. THEREFORE...WILL BRING POPS BACKUP TO
CATEGORICAL LATER THIS MORNING AND AFTERNOON. RAINFALL AMOUNTS MAY
VARY CONSIDERABLY ACROSS THE REGION SINCE WE WILL BE ENTERING THE
WARM SECTOR AND THE PRECIPITATION WILL BE MORE SHOWERY.
HOWEVER...WITH INTENSE FORCING AND HIGH PWATS POCKETS OF TORRENTIAL
RAINFALL ARE EXPECTED. WE EXPECT AN ADDITIONAL 1 TO 3 INCHES OF
RAIN WITH LOCALLY HIGHER AMOUNTS POSSIBLE. ITS ALWAYS TOUGH TO
PINPOINT WHERE THE HEAVIEST AXIS OF RAIN WILL SETUP IN THESE
SITUATIONS. IT DOES LOOK LIKE EASTERN MA/RHODE ISLAND IN THE
STRONGEST LIFT AND STAND THE BEST CHANCE OF SEEING THE HEAVIEST
RAIN. WE WILL HAVE TO BE CONCERNED WITH URBAN AND POOR DRAINAGE
STREET FLOODING SO THE FLOOD WATCH CONTINUES. INDICES ARE
MARGINAL...BUT WILL INCLUDE A SLIGHT CHANCE OF THUNDER THIS
AFTERNOON BUT NOTHING WIDESPREAD IS EXPECTED.
AS FOR HIGH TEMPERATURES...SINCE WE SHOULD ENTER THE WARM SECTOR
EXPECT THEM TO REACH MAINLY INTO THE LOWER 70S. DEWPOINTS WILL BE
MUCH HIGHER THAN YESTERDAY SO IT WILL FEEL MUGGY.
IN ADDITION...THE HIGH SURF ADVISORY CONTINUES TODAY FOR HIGH SURF
AND DANGEROUS RIP CURRENTS ACROSS THE SOUTH COAST...CAPE AND ISLANDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
THE BAND OF HEAVY RAIN SHOULD BEGIN TO LIFT TO OUR NORTH EARLY IN
THE EVENING. IT LOOKS LIKE WE MAY ENTER ANOTHER LULL IN THE
ACTIVITY AS THE STEADY PRECIPITATION EXITS OUR REGION.
HOWEVER...THE ATMOSPHERE WILL REMAIN JUICED SO SCATTERED SHOWERS MAY
POPUP JUST ABOUT ANYWHERE ALONG WITH FOG PATCHES. LOW TEMPERATURES
SHOULD REMAIN MILD WITH CLOUD COVER AND HIGH DEWPOINTS IN PLACE.
EXPECT LOWS TO RANGE FROM BETWEEN 60 AND 65.
SUNDAY...
A HIGHLY UNCERTAIN AND LOW CONFIDENCE FORECAST EXISTS SUNDAY MORNING
INTO THE EARLY AFTERNOON. WE WILL BE WATCHING TROPICAL STORM KYLE
WHICH ALL MODELS HAVE PASSING 50 TO 80 MILES EAST OF THE CAPE AND
ISLANDS. LATEST HURRICANE HUNTER AIRCRAFT MEASUREMENTS ARE THAT ALL
THE WINDS ARE ON THE EAST SIDE OF THE STORM. THIS IS OFTEN THE CASE
WHEN TROPICAL SYSTEMS EVENTUALLY MAKE IT UP TO OUR LATITUDE.
THERE IS CONSIDERABLE DIFFERENCES IN THE 00Z SUITE OF MODEL DATA
AND IMPACTS ACROSS OUR REGION. THE 00Z GFS/CANADIAN MODELS ARE THE
MOST AGGRESSIVE AND EVENTUALLY TRIES TO WRAP IN SOME STRONG WINDS ON
THE WEST SIDE OF THE STORM. THESE MODELS SHOW THE POTENTIAL FOR
TROPICAL STORM FORCE WIND GUSTS ACROSS THE OUTER-CAPE AND
NANTUCKET. HOWEVER...THE UKMET/NAM ARE A BIT FURTHER EAST AND MUCH
WEAKER ON THE WEST SIDE OF THE SYSTEM. THIS WOULD MEAN NOT MUCH
WIND FOR ANY OF OUR REGION. THE LATEST ECMWF MODEL IS SOMEWHAT IN
BETWEEN BUT DOES SHOW THE POTENTIAL FOR SOME BRIEF TROPICAL STORM
WINDS ACROSS THE OUTER-CAPE AND NANTUCKET.
ALL IN ALL...IF KYLE IS ABLE TO FORM WINDS ON THE WESTERN SIDE OF
THE STORM LIKE SOME OF THE MODELS HINT AT...WE COULD SEE A FEW HOURS
OF TROPICAL STORM FORCE WIND GUSTS ON THE OUTER-CAPE AND NANTUCKET.
WILL HAVE TO SEE WHAT THE 12Z MODELS SHOW AND IF THEY TRACK THE
SYSTEM A BIT CLOSER OR FARTHER FROM THE COAST.
AS FOR THE RAIN...WE MAY SEE SEVERAL HOURS OF HEAVY RAIN ALONG THE
COAST DEPENDING ON THE TRACK OF THE SYSTEM. HOWEVER...WE DO NOT
EXPECT THE STEADY RAIN TO MAKE IT THAT FAR INLAND ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
GOOD MODEL AGREEMENT EARLY THIS PERIOD WITH KYLE EXITING THE EASTERN
NEW ENGLAND WATERS SUNDAY EVENING. HOWEVER...A CHANCE OF SHOWERS
WILL LINGER SUN NIGHT AND INTO EARLY MON...AS MID LEVEL TROF AND
ASSOCIATED SURFACE COLD FRONT MOVE ACROSS THE REGION DURING THIS
TIME. BY MON AFTERNOON GOOD MODEL AGREEMENT THAT MEAN TROF AXIS AND
ASSOCIATED DEEP LAYER MOISTURE WILL BE OFFSHORE. THUS...DRY WEATHER
SHOULD RETURN TO THE REGION MON AFTERNOON. THIS DRY WEATHER AND
SEASONABLE TEMPS SHOULD LINGER INTO TUE AS SHORT WAVE RIDGING
DEVELOPS OVER THE REGION AHEAD OF NEXT TROF ENTERING THE GREAT
LAKES.
00Z MODEL GUIDANCE IN GOOD AGREEMENT THAT THE ARRIVAL OF OCTOBER
WILL BE ACCOMPANIED BY A HIGHLY AMPLIFIED PATTERN MID TO LATE NEXT
WEEK...WITH A LONG WAVE TROF SETTING UP ACROSS THE NORTHEAST. GOOD
MODEL AGREEMENT ON THE TIMING OF THE LEAD SHORT WAVE AND ASSOCIATED
COLD FRONT TO ARRIVE HERE IN THE TUE NIGHT - WED TIME FRAME.
THEREFORE...ABOVE AVERAGE CONFIDENCE ON A CHANCE OF SHOWERS HERE TUE
NIGHT INTO WED. THEREAFTER...MODELS DISAGREE ON THE TIMING AND
AMPLITUDE OF THE NEXT SHORT WAVE ROTATING THROUGH THE NORTHEAST
MEAN MID LEVEL TROF. HOWEVER THE OVERALL LARGE SCALE FLOW ACROSS NEW
ENGLAND THU AND FRI WILL BE A COOL AND UNSTABLE CYCLONIC FLOW. SO
EXPECTING MAINLY DRY WEATHER THU AND FRI WITH ISOLATED DIURNAL SHOWER
GIVEN COLD AIR ALOFT WITH MID LEVEL TROF OVERHEAD. COOLER THAN
NORMAL TEMPS EXPECTED AS BOTH 00Z GFS/ECMWF AND 00Z ENSEMBLES
SUGGEST 850 TEMPS COOLING TO ABOUT +4C THU AND THEN DOWN TO +2C FRI!
THEREFORE THE HIGHER TERRAIN MAY ONLY SEE HIGHS FRI IN THE 50S!
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
IFR CONDITIONS WILL BE THE RULE AT ALL SOUTHERN NEW ENGLAND
TERMINALS TODAY...TONIGHT...AND POSSIBLY THROUGH SUNDAY AS MOIST
TROPICAL AIR CONTINUES TO BE TRANSPORTED ONSHORE. THERE WILL BE
PERIODS OF HEAVY RAIN...MOST LIKELY BETWEEN 18Z AND 00Z TODAY. SLIGHT
CHANCE OF A BRIEF TSTM DURING THIS PERIOD. THE RAIN WILL LIKELY
BECOME LIGHTER AFTER 00Z AT MOST TERMINALS BUT CIGS WILL REMAIN
DOWN. FOR SUNDAY...IT/S POSSIBLE THAT AN IMPROVEMENT IN CIGS/VSBYS
WILL BE SEEN DEPENDING ON HOW FAST SOME DRYING CAN OCCUR. RIGHT NOW
IT LOOKS LIKE AT LEAST IFR IN THE MORNING. TROPICAL STORM KYLE LOOKS
TO PASS FAR ENOUGH EAST OF CAPE COD TO LIMIT EFFECTS TO THE
MAINLAND...BUT SOME GUSTY NORTHERLY WINDS COULD OCCUR ON THE CAPE
AND ISLANDS SOMETIME ON SUNDAY AS IT MAKES IT/S CLOSEST APPROACH.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT...IFR CIGS LIKELY. SCATTERED SHOWERS.
MONDAY...IFR/MVFR CIGS IN THE MORNING SHOULD LIFT TO A BKN DECK OF
MVFR/VFR. SCATTERED SHOWERS EARLY BOS-PVD-HYA-ACK.
TUESDAY...VFR WITH MVFR IN SCATTERED SHOWERS POSSIBLE LATE TUE NIGHT.
WEDNESDAY...MVFR IN SCATTERED SHOWERS.
&&
.MARINE...
TODAY...
SCA FOR SEAS WILL CONTINUE FOR OUR OUTER-WATERS AND SOUNDS WITH
PERSISTENT ONSHORE FLOW. IN ADDITION...WE WILL LIKELY SEE A PERIOD
OF SCA WINDS GUSTS FOR MUCH OF OUR SOUTHERN WATERS THIS AFTERNOON
INTO EARLY EVENING. THIS ASSOCIATED WITH THE NEXT PIECE OF
SHORTWAVE ENERGY. THEREFORE...WILL HAVE SCA FOR ALL WATERS EXCEPT
BOSTON HARBOR...CAPE COD AND NARR BAYS.
TONIGHT...
WINDS SHOULD TEMPORARILY DIMINISH BUT SEAS WILL REMAIN WELL ABOVE
SCA THRESHOLDS ACROSS THE OPEN WATERS...SO WILL CONTINUE HEADLINES.
SUNDAY...
A HIGHLY UNCERTAIN FORECAST OVER THE WATERS. KYLE LOOKS TO PASS
EAST OF THE CAPE AND ISLANDS. THEREFORE...THE EXACT TRACK AND HOW
STRONG THE WESTERN SIDE OF KYLE GETS WILL DETERMINE HOW STRONG THE
WINDS GET. IF ITS ABLE TO STRENGTHEN ENOUGH WE COULD HAVE A FEW
HOURS OF TROPICAL STORM FORCE WIND GUSTS AND HIGH SEAS OVER OUR
SOUTHEAST WATERS. CONFIDENCE REMAINS LOW THROUGH.
OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...
SUNDAY NIGHT...KYLE SHOULD BE OVER GEORGES BANK OR GULF OF
ME...TRACKING TOWARD NOVA SCOTIA.
MONDAY AND TUE...FAIRLY LIGHT WINDS AND SUBSIDING SEAS EXPECTED.
WED...SOUTH WINDS WILL INCREASE AS COLD FRONT APPROACHES FROM THE
WEST. SCATTERED SHOWERS EXPECTED. MODEST NW WIND POSSIBLE LATE WED
NIGHT BEHIND COLD FRONT.
&&
.HYDROLOGY...
A LONG LULL IN THE ACTIVITY OCCURRED OVERNIGHT. HOWEVER...ANOTHER
STRONG BURST OF LIFT WILL COINCIDE WITH HIGH PWAT VALUES TO PRODUCE
MORE HEAVY RAIN...LATER THIS MORNING AND AFTERNOON. AN ADDITIONAL 1
TO 3 INCHES OF RAIN WITH LOCALLY HIGHER AMOUNTS ARE EXPECTED. THE
MODELS ARE PINNING RHODE ISLAND AND EASTERN MA FOR GETTING THE
HEAVIEST RAIN THIS AFTERNOON/EVENING. THIS MAY LEAD TO SOME URBAN
AND POOR DRAINAGE STREET FLOODING. THE HEAVIEST RAIN SHOULD LIFT
OFF TO THE NORTH OF OUR REGION THIS EVENING. WE MAY END UP IN A
LULL AGAIN FOR MUCH OF TONIGHT WITH JUST SCATTERED SHOWERS.
TROPICAL STORM KYLE COULD THROW BACK A PERIOD OF HEAVY RAIN ALONG
THE IMMEDIATE COAST ON SUNDAY...BUT RAINFALL AMOUNTS SHOULD QUICKLY
DIMINISH ACROSS THE INTERIOR.
WITH ALL THAT SAID...THE POTENTIAL EXISTS FOR SEVERAL RIVER FORECAST
POINTS TO EXPERIENCE MINOR FLOODING. AREAS OF CONCERN INCLUDE MAIN
TRIBUTARIES TO THE LOWER MERRIMACK RIVER...AS WELL AS PORTIONS OF
THE MAINSTEM MERRIMACK ITSELF. ALSO IN SOUTH CENTRAL MA AND RI...THE
BLACKSTONE RIVER...AND THE PAWTUXET. IN CENTRAL CONNECTICUT THE
FARMINGTON RIVER COULD EXPERIENCE STRONG RISES AS WELL. THERE IS A
CHANCE THESE TRIBUTARIES COULD REACH FLOOD STAGE TONIGHT OR
SUNDAY...STAY TUNED FOR UPDATES. THE PAWTUXET RIVER COULD EXPERIENCE
PROBLEMS EARLIER SINCE IT RESPONDS VERY QUICKLY TO HEAVY RAINS.
TO ACQUIRE SPECIFIC RIVER STAGE FORECASTS GO TO
WEATHER.GOV/BOSTON...CLICK ON RIVERS AND LAKES AHPS...AND CLICK ON
THE FORECAST POINT OF CONCERN.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH SUNDAY MORNING FOR CTZ002>004.
MA...FLOOD WATCH THROUGH SUNDAY MORNING FOR MAZ002>021-026.
HIGH SURF ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR MAZ020-
022>024.
NH...FLOOD WATCH THROUGH SUNDAY MORNING FOR NHZ011-012-015.
RI...FLOOD WATCH THROUGH SUNDAY MORNING FOR RIZ001>007.
HIGH SURF ADVISORY UNTIL 6 PM EDT THIS AFTERNOON FOR
RIZ006>008.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR
ANZ232>235-237-250-254-255.
&&
$$
SYNOPSIS...NOCERA
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...NOCERA
AVIATION...NOCERA/EKSTER
MARINE...NOCERA/FRANK
HYDROLOGY...FRANK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
326 PM CDT SUN SEP 28 2008
.DISCUSSION...
302 PM CDT
MAJOR CHANGE IN WEATHER PATTERN THIS WEEK WILL BRING AN END TO THE
SUNNY WARM DAYS AND PLEASANT NIGHTS AND USHER IN A WEEK OF CHILLY
FALL WEATHER. IN THE SHORT TERM VISIBLE SATELLITE IMAGERY SHOWS
RAPID DISSIPATION OF STRATUS AND FOG OVER IA AND PART OF NORTHERN
IL WHILE MUCH OF WI STILL SOCKED IN. WEAK COLD FRONT WASHING OUT
OVER CENTRAL IL THIS AFTERNOON. LOW LEVEL MOISTURE WILL REMAIN
WITH SURFACE DEWPOINTS REMAINING IN MID TO UPPER 50S. WITH SURFACE
RIDGE MOVING IN...LIGHT WINDS...AMPLE LOW LEVEL MOISTURE...AND
PARTIAL CLEARING OF STRATUS...AREAS OF FOG LIKELY TO DEVELOP LATER
TONIGHT. HOWEVER...SOME PATCHY STRATO-CU MAY REMAIN AND INCREASING
MID-HIGH CLOUDS FROM NEXT WEATHER SYSTEM WILL BE OVERSPREADING
THE AREA LATE TONIGHT OR TOWARD MORNING. THESE FACTOR WILL LIMIT
CHANCES FOR ANY WIDESPREAD DENSE FOG.
MODELS IN PRETTY GOOD AGREEMENT WITH TROF DIGGING INTO GREAT LAKES
AND UPPER MIDWEST MONDAY. SOME INDICATION OF LOW LEVEL JET WHICH
COULD LEAD TO SOME CONVECTION DEVELOPING IN THE NE/KS/MO/IA BORDER
AREA OVERNIGHT. THE LOW LEVEL JET BECOMES MORE WESTERLY AND WEAKENS
MONDAY...SO ANY CONVECTION SHOULD BE WEAKENING AS IT MOVES THROUGH
MO TOWARD WESTERN IL MON MORNING. BROAD AREA OF LIFT ACROSS THE
REST OF THE AREA MONDAY. SO WILL KEEP GOING FORECAST OF HIGH CHANCE
POPS. ISOLATED THUNDER NOT OUT OF THE QUESTION BUT CLOUD COVER
MAY LIMIT HEATING AND DESTABILIZATION. SOME DRYING MONDAY NIGHT
BUT AS COLD CORE UPPER LOW DROPS DOWN TO LOWER MI TUESDAY...WITH
CYCLONIC FLOW AND COLD AIR ALOFT...EXPECT WIDESPREAD STRATO-CU
DECK AND A FEW LIGHT SHOWERS POSSIBLE. AS 850 MB TEMPS DIP TO
AROUND 0 TO +2C...DELTA T FROM LAKE SURFACE WILL APPROACH 15C
WHICH SHOULD BE SUFFICIENT FOR LAKE EFFECT SHOWERS. INITIALLY LOW
LEVEL FLOW WILL BE WNW PUSHING BEST THREAT INTO MI AND N CENTRAL
IN. BUT BY WED AND THU THE FLOW BECOMES MORE NORTHERLY. WARM AIR
ADVECTION AND RIDGING BY THU NIGHT AND FRI SHOULD SHUT OFF THE
LAKE EFFECT. MAX TEMPS WILL STRUGGLE TO REACH 60 TUE THROUGH THU
WITH OVERNIGHT LOWS IN THE LOW TO MID 40S AWAY FROM THE HEAT
ISLAND OF THE CITY. THU NIGHT COULD BE THE COLDEST AS SURFACE
RIDGE BUILDS IN WITH MOSTLY CLEAR SKIES AND LIGHT WINDS.
FINALLY SOME MODERATION NEXT WEEKEND AND TEMPS COULD APPROACH 70
BY SUN. DRY THROUGH THE END OF THE PERIOD.
ALLSOPP
&&
.AVIATION...
145 PM CDT
18Z TAFORS...RECENT ACARS DATA SHOWS SHALLOW MOISTURE REMAINS
TRAPPED UNDER INVERSION WITH TOP AROUND 4K FT AGL. 88D VAD WINDS
SHOWING WINDS AT CLOUD LEVEL FM NNE-NE DECREASING WITH TIME SO
ADVECTION OF MOISTURE SLOWING BUT LARGE AREA OF MVFR STRATOCU FM
LK HURON ACROSS ALL BUT FAR SRN LWR MI AND ACROSS NRN IL AND MOST
OF WI. VIS SATELLITE LOOP SHOWING SOME MIXING OUT OF THIS MOISTURE
S OF THE IL RIVER AND ALSO IN E CENTRAL IA BUT BEING REPLACED BY
DIURNAL STRATOCU WITH DAYTIME HEATING.
DIURNAL DISSIPATION OF CLOUDS TO THE S-W OF THE LOCAL TERMINALS
AND WITH LLVL FLO TO GRADUALLY BECOME SERLY THIS EVE AS RIDGE
AXIS SETTLES FURTHER S ACROSS THE NRN GRTLKS AND UPR MIDWEST
EXPECT MVFR CIGS TO CLR BACK TOWARD AND PAST THE WI STATE LN.
CLRG SKY AND WK TO NIL SFC WND WITH RDG AXIS OVR THE AREA TONIGHT
AND SFC DWPTS FM MID 50S TO LWR 60S LEFT IN PLACE ACROSS THE
REGION EXPECT WIDESPREAD MVFR VSBYS WITH BR...AND AREAS OF FG OR
MIFG.
HI AND MID CLOUDS SPREAD IN FM THE W DURG THE PREDAWN AND MORNING
AS SHRTWV TROF CURRENTLY OVER MANITOBA AND THE DKTS REACHES THE
UPR MIDWEST. CDFNT DOES NOT REACH NW IL TIL AFT 18Z...AND ANY
SHRA/TSRA AHEAD OF THE CDFNT NOT EXPECTED TO NEAR TERMINALS TIL
AFTERNOON.
TRS
&&
.MARINE...
255 PM CDT
HIGH PRESSURE RIDGE EXTENDS SOUTHWEST ACROSS THE UPPER GREAT
LAKES MOVES FROM CENTER OF ANTICYCLONE OVER HUDSON BAY. MODELS
HAVE THE RIDGE AXIS DROP FURTHER SOUTH INTO THE LAKES THEN SHIFT
EAST TO THE CENTRAL LAKES OVERNIGHT...WITH LOW PRESSURE NEAR LAKE
WINNIPEG TRACKING EAST INTO WESTERN ONTARIO. THE LOW STARTS
STARTS TO STRENGTHEN AS IT DROPS SOUTHEAST TO LAKE SUPERIOR BY
MONDAY EVENING...AND SWINGS A COLD FRONT EAST ACROSS LAKE MI MON
NIGHT.
THE LOW DEEPENS FURTHER AS IT MOVES EAST FROM THE CENTRAL LAKES
TO THE LOWER LAKES TUE AND TUE NIGHT...WHILE HIGH PRESSURE BUILDS
ACROSS CENTRAL CANADA AND THE CENTRAL PLAINS. BETWEEN THE DEEPENING
LOW AND THE BUILDING RIDGE A STRONG GRADIENT MOVES INTO THE WESTERN
GREAT LAKES DURING THE DAY TUE. THIS COMBINED WITH ONSET OF STRONG
LOW LEVEL COLD AIR ADVECTION TO RESULT IN INCREASING NORTH AND
NORTH-NORTHWEST WINDS WITH SPEEDS APPROACHING GALE THRESHOLD. WILL
KEEP OPEN WATERS FORECAST BELOW GALE AT THIS TIME.
SPEEDS TO STAY UP TUE NIGHT INTO WED EVENING AS LOW CONTINUES TO
DEEPEN AS IT MOVES SLOWLY EAST TO THE LOWER GREAT LAKES THEN
NORTHEAST INTO SOUTHERN QUEBEC. SQUALLS LIKELY GIVEN EXTREME
INSTABILITY THAT DEVELOPS WITH COLD AIR MOVING OVER MILD LAKE
WATERS. WATERSPOUTS ALSO POSSIBLE BUT WINDS MAY BE TOO STRONG
INITIALLY RESULTING IN SHEARING OF INDIVIDUAL CONVECTIVE CELLS.
BETTER ENVIRONMENT WED NIGHT AND THU MORNING AS THE GRADIENT
RELAXES BUT COLD AIR STILL SQUARELY OVER THE LAKE.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 11 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
256 PM CDT SUN SEP 28 2008
.DISCUSSION...
350 AM CDT
WEAK SURFACE COLD FRONT DRIFTING SLOWLY ACROSS NORTHERN IL EARLY
THIS MORNING...WITH LATEST SURFACE ANALYSIS INDICATING ITS POSITION
ROUGHLY FROM CHICAGO TO JUST SOUTH OF THE QUAD CITIES. FEW ISOLATED
SHOWERS WHICH DEVELOPED ALONG THE FRONT ACROSS NORTH CENTRAL
ILLINOIS LAST EVENING HAVE DISSIPATED...AND FRONT ITSELF EXPECTED TO
BECOME DIFFUSE ACROSS FORECAST AREA TODAY MARKED ONLY BY LINGERING
LOW LEVEL MOIST AXIS OF 55-60 DEG DEW POINT TEMPS. MAIN SHORT TERM
CONCERN NOW IS WITH LOW STRATUS DEVELOPING ACROSS AREA FROM THE
NORTH AS LOW LEVEL NORTHERLY WIND AND COLD ADVECTION IMPINGE UPON
MOIST LOW LEVELS BELOW SHALLOW INVERSION. FORECAST SOUNDINGS FROM
NAM/RUC INDICATE LOW CLOUDS TO CONTINUE TO DEVELOP THIS MORNING...
BEFORE LOW LEVEL FLOW BECOMES MORE ANTICYCLONIC THIS AFTERNOON AND
SHALLOW BOUNDARY LAYER MIXES A LITTLE DEEPER. WITH NORTH WINDS AND
SIGNIFICANT CLOUD COVER...GONE ARE THE 80 DEGREE TEMPS OF LAST
SEVERAL DAYS ESPECIALLY FOR NORTHERN PARTS OF CWA WHERE AFTERNOON
HIGH TEMPS MAY STRUGGLE TO GET VERY FAR ABOVE 70 DEGREES.
WEAK SURFACE HIGH PRESSURE RIDGE SLIPS ACROSS FORECAST AREA THIS
EVENING...SETTING STAGE FOR POTENTIAL FOG DEVELOPMENT OVERNIGHT.
PROVIDED LOWER CLOUDS CLEAR SUFFICIENTLY BY EVENING...ENVIRONMENT
SHOULD BE CONDUCIVE RADIATIONAL COOLING WITHIN LINGERING LOW LEVEL
MOIST ENVIRONMENT LEFT BY TODAYS DECAYING FRONT. FORECAST SOUNDINGS
INDICATE DEPICT INCREASING MIXING RATIOS WITH HEIGHT IN LOWEST FEW
HUNDRED FEET OF BOUNDARY LAYER WITH WINDS BECOMING LIGHT/VARIABLE.
MAV/MET GUIDANCE APPEAR TO PICK UP ON THIS TREND AND HAVE INTRODUCED
MENTION OF FOG ACROSS THE FORECAST AREA THIS EVENING. FOG COULD BE
POTENTIALLY DENSE...THOUGH EVENTUAL MESOSCALE DEW POINT DETAILS AND
EXPECTED INCREASE IN HIGH CLOUDS LATE IN THE NIGHT REDUCE CONFIDENCE
AT THIS TIME.
ATTENTION THEN TURNS QUICKLY TO STRONG SHORT WAVE CURRENTLY MOVING
THROUGH SASKATCHEWAN. AS HAS BEEN ADVERTISED FOR THE PAST SEVERAL
DAYS...THIS SYSTEM REMAINS FORECAST TO DIG SOUTHEAST ACROSS THE
UPPER MIDWEST AND GREAT LAKES REGION MONDAY...WITH CLOSED OFF UPPER
CIRCULATION OVER THE AREA MONDAY NIGHT/TUESDAY. 60 METER HEIGHT
FALLS SPREAD ACROSS THE UPPER MIDWEST DURING THE DAY MONDAY...AS MID
LEVEL SPEED MAX ROTATES AROUND SOUTHERN PERIPHERY OF MAIN UPPER
CIRCULATION. NAM/GFS TIME/HEIGHT SECTIONS DEPICT DEEP LIFT SPREADING
ACROSS FORECAST AREA DURING THE DAY...THOUGH GFS APPEARS TO LIMIT
PRECIP ACROSS THE AREA DUE TO IT DEPICTING MCS DEVELOPMENT SOUTHERN
IA/NORTHERN MO ON NOSE OF LOW LEVEL JET EARLY MONDAY MORNING. WHILE
THIS SCENARIO APPEARS REASONABLE AND IS ALSO SUGGESTED BY OTHER
GUIDANCE...HAVE GONE TOWARD THE MIDDLE/HIGHER END OF GUIDANCE POPS
GIVEN STRENGTH AND DEPTH OF FORCING WITH THIS SYSTEM ALONG WITH ALL
MODELS GENERATING SOME PRECIP ACROSS FORECAST AREA DURING THE DAY
MONDAY.
CLOSED UPPER LOW CONTINUES TO DIG SOUTHEAST ACROSS THE LAKES MONDAY
NIGHT INTO TUESDAY...WITH SURFACE LOW MOVING TO LOWER MICHIGAN BY
MONDAY EVENING AND DRAGGING COLD FRONT ACROSS FORECAST AREA. PASSAGE
OF INITIAL SHORT WAVE AND LOW LEVEL DRYING BEHIND COLD FRONT MONDAY
NIGHT EXPECTED TO DECREASE PRECIP POTENTIAL FROM WEST TO EAST
OVERNIGHT. HOWEVER...LOW LEVEL COLD ADVECTION AND MAIN UPPER LOW
DRIFTING ACROSS THE LAKES TO SET UP PERIOD OF UNSTABLE CONDITIONS
THROUGH MID WEEK...WITH THE POTENTIAL FOR SCATTERED SHOWERS ACROSS
MAINLY EASTERN PORTIONS OF THE FORECAST AREA AND ESPECIALLY DOWNWIND
OF LAKE MICHIGAN. MODELS CONTINUE TO BRING 850 HPA TEMPS DOWN INTO
THE +2/+4 DEG RANGE BY LATE MONDAY NIGHT/TUESDAY...RESULTING IN LAKE
SURFACE TO 850 HPA DELTA T/S AROUND 15. MODIFYING FORECAST SOUNDINGS
OVER SOUTHERN LAKE MICHIGAN FOR THESE CONDITIONS YIELDS DEEP
INSTABILITY WITH LAKE INDUCED CAPES 1000 J/KG AND EQUILIBRIUM LEVELS
ABOVE 20 KFT. THUS APPEARS PROLONGED PERIOD OF LAKE EFFECT SHOWERS
OVER THE LAKE/SOUTH AND SOUTHEAST OF THE LAKE WITH EVEN THE
POTENTIAL FOR SOME THUNDER. BY WEDNESDAY/THURSDAY...MAINLY LAKE
EFFECT PRECIP THREAT AS UPPER LOW DRIFTS A LITTLE FARTHER EAST.
TEMPERATURE WISE...THIS DEEP UPPER TROUGH A TRANSITION TO MUCH
COOLER WEATHER TO RING IN OCTOBER. MODEL LOW LEVEL THERMAL
FORECASTS CONTINUE TO INDICATE DAY TIME HIGHS MAY STRUGGLE MUCH
ABOVE 60 DEGREES MID WEEK...WITH ECMWF AND GEM BOTH INDICATING
ANOTHER REINFORCING PUSH OF COLD AIR THURSDAY NIGHT/FRIDAY AS
UPPER PATTERN IN OMEGA BLOCKING MODE AND TROUGH ONLY SLOWLY MOVES
EAST NEXT WEEKEND.
RATZER
&&
.AVIATION...
145 PM CDT
18Z TAFORS...RECENT ACARS DATA SHOWS SHALLOW MOISTURE REMAINS
TRAPPED UNDER INVERSION WITH TOP AROUND 4K FT AGL. 88D VAD WINDS
SHOWING WINDS AT CLOUD LEVEL FM NNE-NE DECREASING WITH TIME SO
ADVECTION OF MOISTURE SLOWING BUT LARGE AREA OF MVFR STRATOCU FM
LK HURON ACROSS ALL BUT FAR SRN LWR MI AND ACROSS NRN IL AND MOST
OF WI. VIS SATELLITE LOOP SHOWING SOME MIXING OUT OF THIS MOISTURE
S OF THE IL RIVER AND ALSO IN E CENTRAL IA BUT BEING REPLACED BY
DIURNAL STRATOCU WITH DAYTIME HEATING.
DIURNAL DISSIPATION OF CLOUDS TO THE S-W OF THE LOCAL TERMINALS
AND WITH LLVL FLO TO GRADUALLY BECOME SERLY THIS EVE AS RIDGE
AXIS SETTLES FURTHER S ACROSS THE NRN GRTLKS AND UPR MIDWEST
EXPECT MVFR CIGS TO CLR BACK TOWARD AND PAST THE WI STATE LN.
CLRG SKY AND WK TO NIL SFC WND WITH RDG AXIS OVR THE AREA TONIGHT
AND SFC DWPTS FM MID 50S TO LWR 60S LEFT IN PLACE ACROSS THE
REGION EXPECT WIDESPREAD MVFR VSBYS WITH BR...AND AREAS OF FG OR
MIFG.
HI AND MID CLOUDS SPREAD IN FM THE W DURG THE PREDAWN AND MORNING
AS SHRTWV TROF CURRENTLY OVER MANITOBA AND THE DKTS REACHES THE
UPR MIDWEST. CDFNT DOES NOT REACH NW IL TIL AFT 18Z...AND ANY
SHRA/TSRA AHEAD OF THE CDFNT NOT EXPECTED TO NEAR TERMINALS TIL
AFTERNOON.
TRS
&&
.MARINE...
255 PM CDT
HIGH PRESSURE RIDGE EXTENDS SOUTHWEST ACROSS THE UPPER GREAT
LAKES MOVES FROM CENTER OF ANTICYCLONE OVER HUDSON BAY. MODELS
HAVE THE RIDGE AXIS DROP FURTHER SOUTH INTO THE LAKES THEN SHIFT
EAST TO THE CENTRAL LAKES OVERNIGHT...WITH LOW PRESSURE NEAR LAKE
WINNIPEG TRACKING EAST INTO WESTERN ONTARIO. THE LOW STARTS
STARTS TO STRENGTHEN AS IT DROPS SOUTHEAST TO LAKE SUPERIOR BY
MONDAY EVENING...AND SWINGS A COLD FRONT EAST ACROSS LAKE MI MON
NIGHT.
THE LOW DEEPENS FURTHER AS IT MOVES EAST FROM THE CENTRAL LAKES
TO THE LOWER LAKES TUE AND TUE NIGHT...WHILE HIGH PRESSURE BUILDS
ACROSS CENTRAL CANADA AND THE CENTRAL PLAINS. BETWEEN THE DEEPENING
LOW AND THE BUILDING RIDGE A STRONG GRADIENT MOVES INTO THE WESTERN
GREAT LAKES DURING THE DAY TUE. THIS COMBINED WITH ONSET OF STRONG
LOW LEVEL COLD AIR ADVECTION TO RESULT IN INCREASING NORTH AND
NORTH-NORTHWEST WINDS WITH SPEEDS APPROACHING GALE THRESHOLD. WILL
KEEP OPEN WATERS FORECAST BELOW GALE AT THIS TIME.
SPEEDS TO STAY UP TUE NIGHT INTO WED EVENING AS LOW CONTINUES TO
DEEPEN AS IT MOVES SLOWLY EAST TO THE LOWER GREAT LAKES THEN
NORTHEAST INTO SOUTHERN QUEBEC. SQUALLS LIKELY GIVEN EXTREME
INSTABILITY THAT DEVELOPS WITH COLD AIR MOVING OVER MILD LAKE
WATERS. WATERSPOUTS ALSO POSSIBLE BUT WINDS MAY BE TOO STRONG
INITIALLY RESULTING IN SHEARING OF INDIVIDUAL CONVECTIVE CELLS.
BETTER ENVIRONMENT WED NIGHT AND THU MORNING AS THE GRADIENT
RELAXES BUT COLD AIR STILL SQUARELY OVER THE LAKE.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 11 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
146 PM CDT SUN SEP 28 2008
.DISCUSSION...
350 AM CDT
WEAK SURFACE COLD FRONT DRIFTING SLOWLY ACROSS NORTHERN IL EARLY
THIS MORNING...WITH LATEST SURFACE ANALYSIS INDICATING ITS POSITION
ROUGHLY FROM CHICAGO TO JUST SOUTH OF THE QUAD CITIES. FEW ISOLATED
SHOWERS WHICH DEVELOPED ALONG THE FRONT ACROSS NORTH CENTRAL
ILLINOIS LAST EVENING HAVE DISSIPATED...AND FRONT ITSELF EXPECTED TO
BECOME DIFFUSE ACROSS FORECAST AREA TODAY MARKED ONLY BY LINGERING
LOW LEVEL MOIST AXIS OF 55-60 DEG DEW POINT TEMPS. MAIN SHORT TERM
CONCERN NOW IS WITH LOW STRATUS DEVELOPING ACROSS AREA FROM THE
NORTH AS LOW LEVEL NORTHERLY WIND AND COLD ADVECTION IMPINGE UPON
MOIST LOW LEVELS BELOW SHALLOW INVERSION. FORECAST SOUNDINGS FROM
NAM/RUC INDICATE LOW CLOUDS TO CONTINUE TO DEVELOP THIS MORNING...
BEFORE LOW LEVEL FLOW BECOMES MORE ANTICYCLONIC THIS AFTERNOON AND
SHALLOW BOUNDARY LAYER MIXES A LITTLE DEEPER. WITH NORTH WINDS AND
SIGNIFICANT CLOUD COVER...GONE ARE THE 80 DEGREE TEMPS OF LAST
SEVERAL DAYS ESPECIALLY FOR NORTHERN PARTS OF CWA WHERE AFTERNOON
HIGH TEMPS MAY STRUGGLE TO GET VERY FAR ABOVE 70 DEGREES.
WEAK SURFACE HIGH PRESSURE RIDGE SLIPS ACROSS FORECAST AREA THIS
EVENING...SETTING STAGE FOR POTENTIAL FOG DEVELOPMENT OVERNIGHT.
PROVIDED LOWER CLOUDS CLEAR SUFFICIENTLY BY EVENING...ENVIRONMENT
SHOULD BE CONDUCIVE RADIATIONAL COOLING WITHIN LINGERING LOW LEVEL
MOIST ENVIRONMENT LEFT BY TODAYS DECAYING FRONT. FORECAST SOUNDINGS
INDICATE DEPICT INCREASING MIXING RATIOS WITH HEIGHT IN LOWEST FEW
HUNDRED FEET OF BOUNDARY LAYER WITH WINDS BECOMING LIGHT/VARIABLE.
MAV/MET GUIDANCE APPEAR TO PICK UP ON THIS TREND AND HAVE INTRODUCED
MENTION OF FOG ACROSS THE FORECAST AREA THIS EVENING. FOG COULD BE
POTENTIALLY DENSE...THOUGH EVENTUAL MESOSCALE DEW POINT DETAILS AND
EXPECTED INCREASE IN HIGH CLOUDS LATE IN THE NIGHT REDUCE CONFIDENCE
AT THIS TIME.
ATTENTION THEN TURNS QUICKLY TO STRONG SHORT WAVE CURRENTLY MOVING
THROUGH SASKATCHEWAN. AS HAS BEEN ADVERTISED FOR THE PAST SEVERAL
DAYS...THIS SYSTEM REMAINS FORECAST TO DIG SOUTHEAST ACROSS THE
UPPER MIDWEST AND GREAT LAKES REGION MONDAY...WITH CLOSED OFF UPPER
CIRCULATION OVER THE AREA MONDAY NIGHT/TUESDAY. 60 METER HEIGHT
FALLS SPREAD ACROSS THE UPPER MIDWEST DURING THE DAY MONDAY...AS MID
LEVEL SPEED MAX ROTATES AROUND SOUTHERN PERIPHERY OF MAIN UPPER
CIRCULATION. NAM/GFS TIME/HEIGHT SECTIONS DEPICT DEEP LIFT SPREADING
ACROSS FORECAST AREA DURING THE DAY...THOUGH GFS APPEARS TO LIMIT
PRECIP ACROSS THE AREA DUE TO IT DEPICTING MCS DEVELOPMENT SOUTHERN
IA/NORTHERN MO ON NOSE OF LOW LEVEL JET EARLY MONDAY MORNING. WHILE
THIS SCENARIO APPEARS REASONABLE AND IS ALSO SUGGESTED BY OTHER
GUIDANCE...HAVE GONE TOWARD THE MIDDLE/HIGHER END OF GUIDANCE POPS
GIVEN STRENGTH AND DEPTH OF FORCING WITH THIS SYSTEM ALONG WITH ALL
MODELS GENERATING SOME PRECIP ACROSS FORECAST AREA DURING THE DAY
MONDAY.
CLOSED UPPER LOW CONTINUES TO DIG SOUTHEAST ACROSS THE LAKES MONDAY
NIGHT INTO TUESDAY...WITH SURFACE LOW MOVING TO LOWER MICHIGAN BY
MONDAY EVENING AND DRAGGING COLD FRONT ACROSS FORECAST AREA. PASSAGE
OF INITIAL SHORT WAVE AND LOW LEVEL DRYING BEHIND COLD FRONT MONDAY
NIGHT EXPECTED TO DECREASE PRECIP POTENTIAL FROM WEST TO EAST
OVERNIGHT. HOWEVER...LOW LEVEL COLD ADVECTION AND MAIN UPPER LOW
DRIFTING ACROSS THE LAKES TO SET UP PERIOD OF UNSTABLE CONDITIONS
THROUGH MID WEEK...WITH THE POTENTIAL FOR SCATTERED SHOWERS ACROSS
MAINLY EASTERN PORTIONS OF THE FORECAST AREA AND ESPECIALLY DOWNWIND
OF LAKE MICHIGAN. MODELS CONTINUE TO BRING 850 HPA TEMPS DOWN INTO
THE +2/+4 DEG RANGE BY LATE MONDAY NIGHT/TUESDAY...RESULTING IN LAKE
SURFACE TO 850 HPA DELTA T/S AROUND 15. MODIFYING FORECAST SOUNDINGS
OVER SOUTHERN LAKE MICHIGAN FOR THESE CONDITIONS YIELDS DEEP
INSTABILITY WITH LAKE INDUCED CAPES 1000 J/KG AND EQUILIBRIUM LEVELS
ABOVE 20 KFT. THUS APPEARS PROLONGED PERIOD OF LAKE EFFECT SHOWERS
OVER THE LAKE/SOUTH AND SOUTHEAST OF THE LAKE WITH EVEN THE
POTENTIAL FOR SOME THUNDER. BY WEDNESDAY/THURSDAY...MAINLY LAKE
EFFECT PRECIP THREAT AS UPPER LOW DRIFTS A LITTLE FARTHER EAST.
TEMPERATURE WISE...THIS DEEP UPPER TROUGH A TRANSITION TO MUCH
COOLER WEATHER TO RING IN OCTOBER. MODEL LOW LEVEL THERMAL
FORECASTS CONTINUE TO INDICATE DAY TIME HIGHS MAY STRUGGLE MUCH
ABOVE 60 DEGREES MID WEEK...WITH ECMWF AND GEM BOTH INDICATING
ANOTHER REINFORCING PUSH OF COLD AIR THURSDAY NIGHT/FRIDAY AS
UPPER PATTERN IN OMEGA BLOCKING MODE AND TROUGH ONLY SLOWLY MOVES
EAST NEXT WEEKEND.
RATZER
&&
.AVIATION...
145 PM CDT
18Z TAFORS...RECENT ACARS DATA SHOWS SHALLOW MOISTURE REMAINS
TRAPPED UNDER INVERSION WITH TOP AROUND 4K FT AGL. 88D VAD WINDS
SHOWING WINDS AT CLOUD LEVEL FM NNE-NE DECREASING WITH TIME SO
ADVECTION OF MOISTURE SLOWING BUT LARGE AREA OF MVFR STRATOCU FM
LK HURON ACROSS ALL BUT FAR SRN LWR MI AND ACROSS NRN IL AND MOST
OF WI. VIS SATELLITE LOOP SHOWING SOME MIXING OUT OF THIS MOISTURE
S OF THE IL RIVER AND ALSO IN E CENTRAL IA BUT BEING REPLACED BY
DIURNAL STRATOCU WITH DAYTIME HEATING.
DIURNAL DISSIPATION OF CLOUDS TO THE S-W OF THE LOCAL TERMINALS
AND WITH LLVL FLO TO GRADUALLY BECOME SERLY THIS EVE AS RIDGE
AXIS SETTLES FURTHER S ACROSS THE NRN GRTLKS AND UPR MIDWEST
EXPECT MVFR CIGS TO CLR BACK TOWARD AND PAST THE WI STATE LN.
CLRG SKY AND WK TO NIL SFC WND WITH RDG AXIS OVR THE AREA TONIGHT
AND SFC DWPTS FM MID 50S TO LWR 60S LEFT IN PLACE ACROSS THE
REGION EXPECT WIDESPREAD MVFR VSBYS WITH BR...AND AREAS OF FG OR
MIFG.
HI AND MID CLOUDS SPREAD IN FM THE W DURG THE PREDAWN AND MORNING
AS SHRTWV TROF CURRENTLY OVER MANITOBA AND THE DKTS REACHES THE
UPR MIDWEST. CDFNT DOES NOT REACH NW IL TIL AFT 18Z...AND ANY
SHRA/TSRA AHEAD OF THE CDFNT NOT EXPECTED TO NEAR TERMINALS TIL
AFTERNOON.
TRS
&&
.MARINE...
300 AM CDT
NORTH WINDS BEHIND A COLD FRONT TRACKING ACROSS FAR SOUTHERN LAKE
MICHIGAN EARLY THIS MORNING WILL PERSIST THROUGH THE DAY AS A
STRONG RIDGE OF HIGH PRESSURE MOVES ACROSS ONTARIO. DEPTH OF THE
COLD FRONT IS RELATIVELY LIMITED WHICH WILL LIMIT MIXING POTENTIAL
FOR WIND SPEEDS. HOWEVER GIVEN FAVORABLE FETCH AND REPORTS OF 4
FOOT WAVE HEIGHTS AT NORTHERN BUOY EARLY THIS MORNING...HAVE
DECIDED TO GO AHEAD AND ISSUE A SMALL CRAFT ADVISORY FOR THE
ILLINOIS AND INDIANA NEARSHORE WATERS FROM EARLY THIS MORNING
THROUGH THIS EVENING. EXPECTING TO MEET SMALL CRAFT ADV CONDITIONS
MAINLY FOR WAVE HEIGHTS ALTHOUGH GUSTS TO AROUND 25 KNOTS WILL BE
POSSIBLE THROUGHOUT THE DAY. AS THE RIDGE OF HIGH PRESSURE
CONTINUES EASTWARD ACROSS SOUTHERN CANADA WINDS WILL GRADUALLY
VEER MORE EASTERLY THIS EVENING AND WAVE HEIGHTS WILL DIMINISH
STEADILY BY LATE EVENING. NEXT SIGNIFICANT UPPER LEVEL SYSTEM
CURRENTLY MOVING ACROSS SASKATCHEWAN WILL AFFECT THE WESTERN GREAT
LAKES REGION FOR THE EARLY PART OF NEXT WEEK. SOUTH WINDS WILL
DEVELOP ACROSS THE LAKE AHEAD OF THIS SYSTEM ON MONDAY. AS THIS
SYSTEM DROPS SOUTHEAST OF THE REGION TUESDAY...MUCH COLDER AIR
WILL GET DRAWN SOUTHWARD OVER LAKE MICHIGAN AND NORTH GUSTS TO 30
KNOTS WILL BE POSSIBLE TUESDAY/TUESDAY EVENING. WINDS MAY BE A
BIT SLOWER TO SUBSIDE WEDNESDAY/THURSDAY THAN ORIGINALLY THOUGHT
AS MODEL GUIDANCE IS NOW SUGGESTING UPPER LEVEL PATTERN WILL
REMAIN MORE AMPLIFIED WITH A SLOWER EASTWARD PROGRESSION TO LOW
PRESSURE ACROSS THE EASTERN GREAT LAKES.
MARSILI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 11 PM SUNDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
308 PM EDT SUN SEP 28 2008
.SYNOPSIS...
REMANTS OF A LARGE LOW PRESSURE SYSTEM COVERING MUCH OF THE MID
ATLANTIC REGION WILL PASS NORTH OF THE AREA TONIGHT. HIGH PRESSURE
BUILDS ACROSS THE AREA FOR MON AND MON NIGHT. THE NEXT COLD FRONT
MOVES THROUGH LATE TUESDAY...THEN COOLER CANDIAN HIGH PRESSURE
WILL BUILD INTO THE REGION FOR THU. A REINFORCING BUT DRY COLD
FRONT WILL CROSS THE AREA ON FRIDAY...WITH DRY HIGH PRESSURE
EXPECTED FOR NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
WATER VAPOR LOOP SHOWS A WEAKENING TROUGH PASSING OVERHEAD....WITH A
SHORT WAVE TRAILING OVER THE EASTERN GREAT LAKES. ACARS 400-250MB
WIND OBSERVATIONS REVEAL A 50-100KT SOUTHERLY JET OVER NEW ENGLAND
AND EASTERN CANADA...ON THE LEADING EDGE OF THE UPPER TROUGH
APPROACHING THE APPALACHIANS. 11Z SURFACE ANALYSIS PLACED A 1012MB
CYCLONE NEAR BALTIMORE. A TROUGH HAS DEVELOPED ALONG THE
APPALACHIANS...WITH THE NEXT COLD FRONT CROSSING THE LOWER GREAT
LAKES. A 1029MB ANTICYCLONE DOMINATES SOUTH CENTRAL CANADA.
A SLOW TRANSITION BEGINS TODAY AS AN UPPER TROUGH GRADUALLY PASSES
OVER THE REGION THROUGH THE EVENING HOURS. THIS WILL ENCOURAGE A
WEST-NORTHWEST LOW LEVEL FLOW TO DEVELOP AS THE PRESSURE GRADIENT
INCREASES.
GOES/GPS PRECIPITABLE WATER OBSERVATIONS INDICATE 1.5-1.75" FROM
NORTHERN VIRGINIA NORTHEAST INTO NEW ENGLAND. THIS SUGGESTS THE BEST
COVERAGE OF RAINFALL SHOULD BE ACROSS THE NORTHEAST FORECAST AREA
THIS AFTERNOON AND EARLY EVENING AS THE UPPER TROUGH PASSES. MORE
SCATTERED DEVELOPMENT WILL BE POSSIBLE ACROSS THE WESTERN FORECAST
AREA COINCIDING WITH LOW LEVEL CONVERGENCE ZONE ACTING ON RESIDUAL
MOISTURE.
MOST CHALLENGING PART OF THE FORECAST REVOLVES AROUND LOW CLOUD/FOG
POTENTIAL. LAST NIGHT...TO THE SOUTHWEST OF THE SURFACE
LOW...COPIOUS AMOUNT OF DENSE FOG DEVELOPED ACROSS THE CAROLINAS.
TONIGHT HOWEVER...THE UPPER LOW HAS WEAKENED AND WILL BE TO THE
EAST...AND NORTHWESTERLY FLOW WILL STRENGTHEN ABOVE THE SURFACE.
HOWEVER...RESIDUAL LOW LEVEL MOISTURE LIKELY WILL NOT BE SCOURED
OUT. THUS...THINK A MIX OF LOW CLOUDS AND FOG WILL BE COMMON...WITH
FOG WHERE LOWER LEVELS TEND TO DECOUPLE...AND STRATUS WHERE MIXING
REMAINS STRONGER.
ONCE AGAIN WENT ABOVE MOS GUIDANCE FOR LOW TEMPERATURES...WHICH HAS
BEEN WORKING OUT WELL RECENTLY. HAVE TO GO WELL UPSTREAM TO SEE
DEWPOINTS IN THE 50S AT THIS HOUR.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
NORTHWEST FLOW MIXES OUT STICKY AIRMASS MONDAY. DRYING EXPECTED TO
OFFSET ANY COOL ADVECTION...LEADING TO SIMILAR DAYTIME HIGHS. MOSTLY
SUNNY TO SUNNY SKIES DEVELOP WITH WEAK RIDGING ALOFT.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE MON NIGHT WILL RETREAT OFF THE COAST IN ADVANCE OF A
COLD FRONT MOVING OUT OF THE OH VALLEY. THE FRONT CROSSES THE
REGION ON TUE USHERING IN COOLER...SLIGHTLY BELOW NORMAL
TEMPERATURES FOR MID WEEK. MODELS SHOW BY MID WEEK...A STRONG
UPPER LEVEL LOW ESTABLISHED OVER THE GREAT LAKES REGION...WITH A
RIDGE OF HIGH PRESSURE ACROSS THE ROCKIES. THE TROUGH IS THEN
REINFORCED BY ANOTHER SHOT OF ENERGY ON FRIDAY...THEN LIFTS OUT TO
THE NEW ENGLAND-CANADIAN MARITIME NEXT WEEKEND.
OTHER THAN A CHANCE OF PRECIP WITH THE FRONT ON TUE...EXPECT HIGH
PRES AND LOW POPS THROUGH THE REMINDER OF TH EXTENDED.
TEMPERATURES WILL BE ON THE COOL SIDE. ALSO...BY WEEKS END ON FRI
AND SAT...SOME OF THE FAR N AND W VALLEYS COULD SEE PATCHY FROST.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
SHOWERS AND PERHAPS A FEW THUNDERSTORMS WILL AFFECT THE REGION AS AN
UPPER TROUGH PASSES OVER THE REGION. THIS WILL ALSO BE RESPONSIBLE
FOR SETTING UP NORTHWEST FLOW ACROSS THE AREA THROUGH MONDAY. ENOUGH
RESIDUAL MOISTURE SHOULD REMAIN TO ALLOW AREAS OF IFR
CEILINGS/VISIBILITIES TO DEVELOP OVERNIGHT...MIXING OUT SHORTLY
AFTER SUNRISE.
FOR THE EXTENDED...MON NIGHT THROUGH FRIDAY...A COLD FRONT WILL
BRING A THREAT OF SHOWERS AND TSTMS TUE AFTERNOON INTO TUE NIGHT.
MVFR TO LOCAL IFR CIGS/VSBYS POSSIBLE IN ANY PRECIP THAT ACCOMPANIES
THE FRONT. OTHERWISE...HIGH PRESS EXPECTED WITH VFR CONDITIONS.
&&
.MARINE...
LIGHT WINDS WILL GENERALLY BECOME MORE WESTERLY AS THE AFTERNOON
PROGRESSES. SHOWERS AND PERHAPS A THUNDERSTORM WILL AFFECT THE
WATERS AT TIMES THROUGH THE EARLY EVENING.
NORTHERLY FLOW STRENGTHENS OVERNIGHT AS HIGH PRESSURE BEGINS TO
BUILD INTO THE REGION. A SMALL CRAFT ADVISORY HAS BEEN POSTED FOR
THE MARYLAND CHESAPEAKE BAY LATE THIS EVENING THROUGH MID MORNING.
SOUTHERLY WIND GUSTS ON TUE AHEAD OF THE NEXT COLD FRONT COULD
APPROACH SCA LEVELS TUE AFTERNOON AND EVENING. SCA WIND GUSTS ALSO
POSSIBLE ON FRI POST-FRONTAL. OTHERWISE WINDS/WAVES EXPECTED TO
REMAIN BELOW SCA LEVELS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 10 AM EDT
MONDAY FOR ANZ530>534.
&&
$$
SYNOPSIS...SMZ
NEAR TERM...SJR
SHORT TERM...SJR
LONG TERM...SMZ
AVIATION...SJR
MARINE...SJR
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1108 AM EDT SAT SEP 27 2008
.SYNOPSIS...
A SLOW MOVING UPPER LOW WILL PRODUCE CONVECTIVE PRECIPITATION
THROUGH SUNDAY BEFORE EXITING INTO NEW ENGLAND. HIGH PRESSURE WILL
BUILD OVER THE REGION FOR MONDAY...BUT THE NEXT COLD FRONT WILL PASS
THROUGH THE REGION TUESDAY INTO WEDNESDAY. A TROUGH OF LOW PRESSURE
WILL BUILD IN BEHIND THIS FRONT FOR THE LATTER PART OF THE WEEK
BRINGING COOLER CONDITIONS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WATER VAPOR LOOP SHOWS AN UPPER BEGINNING TO FILL AND LIFT NORTHWARD
OVER THE APPALACHIANS AHEAD OF A SHORTWAVE TROUGH APPROACHING THE
WESTERN GREAT LAKES. ACARS 400-250MB WIND OBSERVATIONS REVEAL
MAJORITY OF 50-80KT JET ASSOCIATED WITH NEARBY UPPER LOW IS ION THE
NORTHEAST PORTION OF THE CIRCULATION...APPROACHING THE MEAN
WESTERLIES ACROSS SOUTHERN CANADA. 11Z SURFACE ANALYSIS PLACED A
1011MB OCCLUDED CYCLONE NEAR ASHEVILLE. THE WARM FRONT HAS MOVED
INLAND AND IS NOW ROUGHLY ALONG THE INTERSTATE 95 CORRIDOR...THEN
NORTHEAST OFF THE JERSEY COAST. THE COLD FRONT EXTENDS WELL OFFSHORE
OF THE CAROLINAS. THE NEXT COLD FRONT WAS CROSSING THE WESTERN GREAT
LAKES AND MIDWEST.
POSITION OF THE WARM/COASTAL BOUNDARY AND THE SOUTH-NORTH DRYSLOT
ROTATING NORTHWARD WILL HELP DELINEATE CONDITIONS THIS AFTERNOON. TO
THE WEST...A CLOUDIER/FOGGY AND COOLER REGIME WILL REMAIN IN PLACE
WITH SCATTERED TO NUMEROUS SHOWERS UNDER THE UPPER LOW. FURTHER
EAST...BREAKS IN LOWER CLOUDS SHOULD LEAD TO LOW TO MODERATE
DESTABILIZATION...AND THE DEVELOPMENT OF MORE VIGOROUS SHOWERS AND
THUNDERSTORMS. 03Z SREF INDICATES UP TO 30KTS EFFECTIVE SHEAR IN
PLACE. GIVEN DEEP CYCLONIC FLOW AND PRESENCE OF HYBRID SYSTEM...WILL
HAVE TO MONITOR FOR TRAINING CONVECTION. EARLY THIS MORNING...ONE
SUCH SITUATION AROSE JUST OUTSIDE BALTIMORE CITY WITH A QUICK 2-3
INCHES OF RAINFALL AND SWIFT WATER RESCUES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
WEAKENING SURFACE AND UPPER LEVEL LOWS WILL CONTINUE TO MOVE ACROSS
THE MID ATLANTIC OVERNIGHT. WIDESPREAD PRECIP SHOULD BEGIN TO
DECREASE FROM SOUTH TO NORTH...ESPECIALLY AFTER MIDNIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AN UPPER-LEVEL LOW AND ITS ASSOCIATED COLD FRONT WILL PASS THROUGH
THE REGION SUNDAY. WITH DEEP LAYER MOISTURE IN PLACE...THIS WILL
TRIGGER SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. PRECIPITATION
SHOULD MOVE OUT OF THE AREA OVERNIGHT SUNDAY AS HIGH PRESSURE BUILDS
IN FROM THE WEST.
HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH MONDAY NIGHT BRINGING
DRY CONDITIONS ALONG WITH SEASONABLE TEMPERATURES. THE NEXT COLD
FRONT WILL PASS THROUGH THE REGION TUESDAY INTO WEDNESDAY BRINGING A
CHANCE FOR SHOWERS. A POTENT UPPER-LEVEL LOW WILL DEVELOP OVER
EASTERN CANADA BEHIND THIS FRONT FOR THE LATTER PART OF THE WEEK.
THIS WILL CARVE OUT A TROUGH OF LOW PRESSURE OVER THE MID-ATLANTIC
BRINGING COOLER CONDITIONS. CANADIAN SURFACE HIGH SHOULD BUILD CLOSE
ENOUGH TO THE MID-ATLANTIC TO BRING DRY CONDITIONS DURING THIS
PERIOD.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
COOL SEASON PATTERN PERSISTS AS AN UPPER LOW DRIFTS NORTHWARD OVER
THE REGION TODAY. THE POSITION OF A WARM FRONT...ROUGHLY ALONG
INTERSTATE 95...SHOULD DELINEATE BETTER MIXING TO THE EAST THIS
AFTERNOON. THIS HOWEVER IS EXPECTED TO LEAD TO DESTABILIZATION AND
THE THREAT FOR ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT.
FURTHER WEST...IFR CEILINGS/VISIBILITIES WILL REMAIN MORE STUBBORN
THROUGHOUT THE DAY WHILE THE THREAT OF A FEW PASSING SHOWERS WILL
REMAIN.
PLENTY OF LOW-LEVEL MOISTURE WILL BRING LOW CLOUDS SUNDAY MORNING
WITH MVFR/IFR CIGS AND VSBYS POSSIBLE. CIGS/VSBYS SHOULD IMPROVE BY
SUNDAY AFTERNOON...BUT SCATTERED SHOWERS/T-STORMS MAY CONTINUE TO
BRING PERIODS OF MVFR/IFR CIG AND VSBYS.
HIGH PRESSURE WILL BRING A RETURN OF VFR CONDITIONS SUNDAY NIGHT
THROUGH MONDAY. THE NEXT COLD FRONT WILL BRING A CHANCE FOR SHOWERS
TUESDAY AND WEDNESDAY.
&&
.MARINE...
LIGHT TO MODERATE EASTERLY FLOW PERSISTS TODAY ON THE WARM SIDE OF
THE FRONTAL ZONE. FLOW BECOMES MORE SOUTHERLY TONIGHT AS A WEAK AREA
OF LOW PRESSURE ADVANCES NORTH.
A COLD FRONT WILL PASS THROUGH THE WATERS SUNDAY INTO SUNDAY NIGHT
BRINGING THE CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS. WIND
GUSTS MAY APPROACH SCA CRITERIA BEHIND THE FRONT OVERNIGHT SUNDAY
INTO MONDAY MORNING. WILL LEAVE WIND SPEEDS JUST BELOW CRITERIA FOR
NOW WHICH IS IN LINE WITH LATEST GUIDANCE.
NO FLAGS ARE EXPECTED FOR LATER MONDAY THROUGH WEDNESDAY.
&&
.HYDROLOGY...
IFLOWS GAUGES HAVE REPORTED 2-4" OF RAINFALL DURING THE PAST 24
HOURS IN THE HIGHER TERRAIN NEAR WAYNESBORO. THE MARFC HAS THUS
ADJUSTED 1HR FLASH FLOOD GUIDANCE TO BE ABOUT 0.75" AND 3HR
GUIDANCE ABOUT 1.25" IN THIS LOCALIZED AREA. WILL HAVE TO MONITOR
HEAVY RAIN POTENTIAL IN THIS AREA WHICH MAY LEAD TO FLASH FLOODING
THIS AFTERNOON.
&&
.TIDES/COASTAL FLOODING...
TIDES ONCE AGAIN EXCEEDED ADVISORY LEVELS LAST NIGHT. IT APPEARS
THAT THE HIGHER TIDAL DEPARTURE ANOMALIES HAVE ADVANCED UPSTREAM
INTO THE TIDAL POTOMAC RIVER AND MARYLAND CHESAPEAKE
BAY...COINCIDENT WITH THE WARM FRONT LIFTING TO THE NORTHWEST. WHILE
THE PRESSURE GRADIENT HAS WEAKENED AT THE MOUTH OF THE BAY...AM NOT
CONFIDENT THE SITUATION WILL ABATE BY NEXT HIGH TIDE...ESPECIALLY
CONSIDERING THE NEW MOON. HAVE EXTENDED THE COASTAL FLOOD ADVISORY
THROUGH THIS EVENING. WILL HAVE TO MONITOR THE TRACK OF KYLE INTO
EARLY NEXT WEEK AS THIS SYSTEM WILL BRING AN INFLUX OF HIGHER SEAS
ACROSS THE WESTERN ATLANTIC...WOULD COULD INHIBIT FLOW OUT OF THE
CHESAPEAKE BAY SYSTEM BETWEEN HIGH AND LOW TIDES.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...COASTAL FLOOD ADVISORY UNTIL 10 PM EDT THIS EVENING FOR DCZ001.
MD...COASTAL FLOOD ADVISORY UNTIL 10 PM EDT THIS EVENING FOR MDZ007-
011-013-014-016>018.
VA...COASTAL FLOOD ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
VAZ052>055-057.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ROGOWSKI
NEAR TERM...ROGOWSKI
SHORT TERM...LISTEMAA
LONG TERM...LASORSA
AVIATION...ROGOWSKI/LASORSA
MARINE...ROGOWSKI/LASORSA
HYDROLOGY...ROGOWSKI
TIDES/COASTAL FLOODING...ROGOWSKI
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
750 AM EDT SAT SEP 27 2008
.UPDATE...
DESPITE PRESENCE OF DPVA FROM SHRTWV TROUGH CROSSING EASTERN MN AND
RIGHT ENTRANCE REGION FORCING ASSOCIATED WITH AN UPPER JET STREAK
OVER NRN ONTARIO...SHOWERS THAT WERE OVER WESTERN UPPER MI ABOUT 4-5
HOURS AGO HAVE PRACTICALLY DISSIPATED. SOME STILL PERSIST OVER
CENTRAL WI WHERE BETTER INSTABILITY EXISTS. THEREFORE...HAVE UPDATED
FORECAST TO NOT GO AS PESSIMISTIC ON PCPN. HOWEVER...BEHIND THE
COLD FRONT OVER NE MN...MANY SITES ALONG WITH THE KDLH RADAR DEPICT
SOME SCATTERED SHOWERS OR -DZ FROM THE LOW CLOUDS THERE. SINCE THIS
WOULD BE MOVING ACROSS UPPER MICHIGAN TODAY...HAVE MAINTAINED
CHANCES OF SHOWERS. IN ADDITION...ONCE THE FRONT CROSSES CENTRAL
UPPER MICHIGAN AND ALLOWS THE WINDS TO TURN MORE NORTHERLY THIS
AFTN...SOUNDINGS SUGGEST A GOOD POTENTIAL FOR UPSLOPE DZ...ALSO
WARRANTING KEEPING SOME CHANCE POPS IN. DAY SHIFT MAY NEED TO MAKE
MORE ADJUSTMENTS TO THE PCPN FORECAST.
&&
.DISCUSSION... (ISSUED AT 4 AM EDT)
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WSW FLOW ALF FM
THE PAC NW INTO SE CAN ON THE NW FLANK OF MEAN RDG OVER THE ERN
CONUS. WARM SW FLOW ON THE WRN FLANK OF SFC HI PRES OFF THE SE CNDN
COAST PUMPED UP H85 TEMPS AOA 15C INTO THE UPR GRT LKS...PUSHING HI
TEMPS OVER THE FA TO DAILY RECORD RANGE ON FRI. BUT A FAIRLY STRONG
SHRTWV OVER THE DAKOTAS AND WHICH IS EMBEDDED IN THE WSW FLOW ALF IS
PUSHING E INTO MN...SUPPORTING A STRONG COLD FNT THAT IS APRCHG THE
WRN ZNS EARLY THIS MRNG. 00Z MPX SDNG (AHD OF THE FNT) AND 01Z
TAMDAR SDNG FM SAW ARE QUITE DRY/CAPPED...SO LTL PCPN IS FALLING
AHEAD OF THE FNT. BUT QUITE A BIT OF SHRA/TSRA NOTED ON THE COOL
SIDE OF THE FNT SUPPORTED BY CONSIDERABLE DEEP LYR H85-3 QVECTOR
CNVGC/UPR DIVERGENCE IN THE RRQ OF 100KT H3 JET MAX NEAR JAMES BAY
AS WELL AS SHARP H85-7 FGEN/MSTR CNVGC ASSOCIATED WITH FNT ITSELF.
ANOTHER COOL FNT TO THE N OF THE PCPN FOCUS IS EVIDENT DROPPING THRU
NW ONTARIO AND NW MN. SINCE THE 00Z INL SDNG IS RATHER DRY IN THE
LLVLS...THERE IS ONLY ISOLD -SHRA ALG THIS REINFORCING FNT. BUT
QUITE A BIT OF LO CLD IS PRESENT ON THE COOL SIDE OF THIS BNDRY WITH
SHALLOW COOL AIR UNDERCUTTING WARMER AIR TO THE S OF THE FNT.
MAIN FCST CONCERNS THIS PACKAGE INCLUDE SHRA CHCS/COVG TDAY THEN
TEMPS/POTENTIAL FOR LO CLDS AND DZ THE REST OF THE WEEKEND IN THE
WAKE OF THE COLD FROPA.
FOR TDAY...SHRTWV NOW IN THE DAKOTAS IS PROGGED TO SWING EWD ACRS
THE UPR GRT LKS WITH 24HR H5 HGT FALLS ARND 100M FCST BTWN 0Z SAT
AND 0Z SUN. THE FIRST COOL FNT IS FCST TO REACH ERY AT 18Z. GUIDANCE
SHOWS THE SECOND FNT CATCHING UP QUICKLY TO THE FIRST FNT THRU THE
MRNG SO THAT IT WOULD REACH ERY ARND 21Z. ALTHOUGH THE DPVA AHD OF
THE SHRTWV AND ACCOMPANYING H85-5 QVECTOR CNVGC AS WELL AS THE
FAIRLY SHARP H85-7 FGEN ARE PROGGED TO PERSIST ALG THE FNT THRU THE
DAY...GFS/NAM SHOW THE STRONGER UPR DVGC/H7-3 QVECTOR DVGC/H85 MSTR
CNVGC FADING QUICKLY AFT 18Z AS THE H3 JET AXIS TRANSLATES FASTER E
THAN THE FNT AND THE STRONGER WINDS SPEEDS TEND TO LIFT NE. SO
ALTHOUGH SFC HTG/DESTABILIZATION MIGHT TEND TO ALLOW SOME PRE
FRONTAL SHRA/TSRA TO DVLP (COVG WL STILL BE LIMITED BY THE
CONVECTIVE TEMP OF 95 OBSVD ON THE 00Z MPX RAOB)...THE WDSPRD SHRA
ACTIVITY ON THE COOL SIDE OF THE BNDRY SHOULD TEND TO DIMINISH AFT
NOON. AS FOR TEMPS...PASSAGE OF BOTH FNTS WITH ACCOMPANYING INCRS IN
CLD/INFLUX OF COOLER AIR WL CAUSE UNSEASONABLY WARM TEMPS TO FALL
OFF...SO WL NEED A NON-DIURNAL TEMP CURVE TO SIMULATE DAYTIME TEMPS.
FOR TNGT...HI PRES IS FCST TO BLD INTO NRN ONTARIO IN THE HGT RISES/
DNVA IN THE WAKE OF THE DEPARTING SHRTWV. ALTHOUGH SUPPORT FOR
LARGER SCALE PCPN WL END WITH FLOW TENDING TOWARD ACYC...UPSLOPE NNE
FLOW WL CAUSE LO CLD TO LINGER IN AREAS DOWNWIND OF LK SUP. NAM FCST
SDNGS WOULD SUG DZ AS WELL...BUT UPSTREAM SFC DWPT DEPRESSIONS
BEHIND THE SECOND COLD FNT ARE RATHER HI IN EXCESS OF 10F UNDER THE
SC. ALTHOUGH PASSAGE OF THE AIRMASS OVER LK SUP MIGHT RESULT IN SOME
MOISTENING...PREFER THE GFS/LOCAL WRF-ARW FCST SHOWING ENUF LLVL DRY
AIR TO REMOVE MENTION OF DZ AND FOG. THE ONLY EXCEPTION WL BE OVER
THE HIER TERRAIN OF THE NCNTRL IN THE EVNG BEFORE ARRIVAL OF DRIER
LLVL AIR. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR W WHERE LLVL
NE FLOW WL DOWNSLOPE. FCST MIN TEMPS INTO THE 30S IN THESE AREAS.
AS THE HI PRES RDG IN ONTARIO DRIFTS SLOWLY E ON SUN...THE LLVL FLOW
WL GRDLY VEER MORE ESE IN THE AFTN. SO PERSISTENT LO CLD IN THE NE
UPSLOPE AREAS SHOULD GRDLY DSPT WITH DCRSG TRAJECTORY/MODIFICATION
OVER LK SUP AS WELL AS SINKING SUBSIDENCE INVRN. MIXING TO H85 ON
GFS FCST SDNGS YIELDS HI TEMPS IN THE 60 TO 65 RANGE...BUT TENDED A
LTL COOLER WHERE NE VEERING E FLOW MAY MAINTAIN MORE SC LONGER.
NEXT SHRTWV DROPPING SEWD IN NW FLOW ALF IS FCST TO APRCH INL BY 12Z
MON...WITH ATTENDANT LO PRES TROF NEARING WRN LK SUP. GFS/NAM/UKMET
SHOW SOME FAIRLY IMPRESSIVE H5 HGT FALLS ARPCHG 100M DURING THE NGT
IN FAIRLY SHARP DPVA/DEEP LYR H85-3 QVECTOR CVNGC AHEAD OF THE
SHRTWV. BUT FAIRLY LIMITED MSTR SHOWN IN FCST SDNGS WARRANTS NO MORE
THAN THE GOING 20-30 POP...HIEST OVER THE W. ARRIVAL OF THE DYNAMICS
DURING MIN HTG TIME ALSO WARRANTS REMOVAL OF TS MENTION AS EVEN THE
MOISTER NAM SHOWS MUCAPE NO MORE THAN 200 J/KG. EXPECT THE LOWEST
MIN TEMPS OVER THE INTERIOR E WHERE ANTECEDENT DRY AIRMASS WL LINGER
THE LONGEST.
AS SHRTWV DIGS INTO THE UPR GRT LKS ON MON...BUMPED UP POPS
ESPECIALLY OVER THE NRN TIER ZNS ON CYC SIDE OF SHRTWV TRACK WHERE
DRY SLOTTING WOULD BE LESS LIKELY. UPR JET SUPPORT/ENHANCED UPR DVGC
IN LEFT EXIT OF THIS FEATURE ARRIVES IN THE AFTN IN TANDEM WITH
DIURNAL HTG...SO WENT WITH THE HIEST POPS AND INCLUDED MENTION OF TS
THEN. ALTHOUGH DYNAMICS EXIT MON NGT...MAINTAINED HI CHC POPS NEAR
LK SUP WITH CYC NLY FLOW OFF THE WATER AND FALLING H85 TEMPS TOWARD
0C INDICATING POTENTIAL FOR LK EFFECT SHRA.
COORDINATED WITH APX/GRB/DLH.
&&
.AVIATION (FOR THE 12Z TAF ISSUANCE)...
SHOWERS THAT MOVED INTO CMX EARLIER IN THE NIGHT HAVE MOSTLY
DISSIPATED AS THEY HEADED INTO SAW...LIKELY DUE TO DRY AIR PRESENT.
AFTER A BRIEF PERIOD OF VFR CONDITIONS AT CMX IN THE WAKE OF THE
SHOWERS...A TROUGH MOVED THROUGH...SWITCHING THE WINDS TO AN UPSLOPE
NW WIND DIRECTION AND THEREFORE RESULTING IN A LIFR CLOUD DECK. THIS
TROUGH SEEN ON RADAR SHOULD PASS ACROSS SAW BTWN 12-13Z...WITH LOW
CLOUDS OF THE MVFR/IFR VARIETY FOLLOWING AN HOUR OR TWO BEHIND.
THE ACTUAL COLD FRONT STILL APPEARS TO BE OVER WESTERN LAKE
SUPERIOR. BEHIND THE FRONT IS AN AREA OF MVFR CLOUDS AND A FEW
SHOWERS ACROSS NE MN. SINCE DEWPOINTS IN THIS AIRMASS ARE LOWER THAN
THOSE PRESENT AT CMX...THOUGHT IS THAT THE CIGS AT CMX SHOULD
IMPROVE ONCE THE FRONT PASSES THROUGH THERE. STILL...IFR CIGS ARE
EXPECTED TO CONTINUE THROUGH EARLY AFTN UNTIL DRIER LOW LEVEL AIR
ALLOWS CIGS TO GO MVFR...AND LIKELY VFR LATE THIS EVENING. A
DIFFERENT STORY IS EXPECTED AT SAW BEHIND THE COLD FRONT...SINCE
WINDS WILL TURN DUE NORTH...RESULTING IN UPSLOPE FLOW OF LAKE
SUPERIOR MOISTURE. INDICATIONS ARE THAT IFR CIGS ARE LIKELY BEHIND
THE FRONT...AND WOULD NOT COMPLETELY RULE OUT LIFR WITH SOME DRIZZLE
AND BR AS WELL. IFR CIGS SHOULD PERSIST THROUGH TONIGHT AT SAW WITH
PERSISTENT NORTH TO NE FLOW.
&&
.MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)...
COLD FRONT MOVING OFF OF THE MN ARROWHEAD WILL CROSS LAKE SUPERIOR
TODAY. BEHIND THE FRONT...A PERIOD OF NORTH WINDS TO 30 KT IS
EXPECTED ON THE EASTERN TWO THIRDS OF LAKE SUPERIOR...WHICH SHOULD
GRADUALLY DIMINISH ON SUN DUE TO THE PRESSURE GRADIENT RELAXING FROM
HIGH PRESSURE CROSSING NORTHERN ONTARIO. AS THE HIGH SHIFTS EAST SUN
NIGHT...LOW PRESSURE IS EXPECTED TO DROP SE OUT OF NW ONTARIO...
CROSSING LAKE SUPERIOR ON MON. SE WINDS ON EASTERN LAKE SUPERIOR ON
THE EAST SIDE OF THE LOW MAY REACH 25 KT SUN NIGHT AND MON. IN THE
WAKE OF THE LOW MON NIGHT AND TUE...EXPECT NW TO NORTH WINDS TO
INCREASE TO UP TO 25 KT...STRONGEST ON EASTERN LAKE SUPERIOR.
FORECAST BECOMES MUCH MORE UNCERTAIN BEYOND TUE. HOWEVER...IT DOES
APPEAR A COLD FRONT WILL BE DROPPING SOUTH ACROSS LAKE SUPERIOR
EITHER WED OR THU...WITH UP TO 30 KT NW WINDS POSSIBLE BEHIND THE
FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...NONE.
LAKE SUPERIOR...NONE.
LAKE MICHIGAN...NONE.
&&
$$
UPDATE...AJ
DISCUSSION...KC
AVIATION...AJ
MARINE...AJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
400 AM EDT SAT SEP 27 2008
.DISCUSSION...
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WSW FLOW ALF FM
THE PAC NW INTO SE CAN ON THE NW FLANK OF MEAN RDG OVER THE ERN
CONUS. WARM SW FLOW ON THE WRN FLANK OF SFC HI PRES OFF THE SE CNDN
COAST PUMPED UP H85 TEMPS AOA 15C INTO THE UPR GRT LKS...PUSHING HI
TEMPS OVER THE FA TO DAILY RECORD RANGE ON FRI. BUT A FAIRLY STRONG
SHRTWV OVER THE DAKOTAS AND WHICH IS EMBEDDED IN THE WSW FLOW ALF IS
PUSHING E INTO MN...SUPPORTING A STRONG COLD FNT THAT IS APRCHG THE
WRN ZNS EARLY THIS MRNG. 00Z MPX SDNG (AHD OF THE FNT) AND 01Z
TAMDAR SDNG FM SAW ARE QUITE DRY/CAPPED...SO LTL PCPN IS FALLING
AHEAD OF THE FNT. BUT QUITE A BIT OF SHRA/TSRA NOTED ON THE COOL
SIDE OF THE FNT SUPPORTED BY CONSIDERABLE DEEP LYR H85-3 QVECTOR
CNVGC/UPR DIVERGENCE IN THE RRQ OF 100KT H3 JET MAX NEAR JAMES BAY
AS WELL AS SHARP H85-7 FGEN/MSTR CNVGC ASSOCIATED WITH FNT ITSELF.
ANOTHER COOL FNT TO THE N OF THE PCPN FOCUS IS EVIDENT DROPPING THRU
NW ONTARIO AND NW MN. SINCE THE 00Z INL SDNG IS RATHER DRY IN THE
LLVLS...THERE IS ONLY ISOLD -SHRA ALG THIS REINFORCING FNT. BUT
QUITE A BIT OF LO CLD IS PRESENT ON THE COOL SIDE OF THIS BNDRY WITH
SHALLOW COOL AIR UNDERCUTTING WARMER AIR TO THE S OF THE FNT.
MAIN FCST CONCERNS THIS PACKAGE INCLUDE SHRA CHCS/COVG TDAY THEN
TEMPS/POTENTIAL FOR LO CLDS AND DZ THE REST OF THE WEEKEND IN THE
WAKE OF THE COLD FROPA.
FOR TDAY...SHRTWV NOW IN THE DAKOTAS IS PROGGED TO SWING EWD ACRS
THE UPR GRT LKS WITH 24HR H5 HGT FALLS ARND 100M FCST BTWN 0Z SAT
AND 0Z SUN. THE FIRST COOL FNT IS FCST TO REACH ERY AT 18Z. GUIDANCE
SHOWS THE SECOND FNT CATCHING UP QUICKLY TO THE FIRST FNT THRU THE
MRNG SO THAT IT WOULD REACH ERY ARND 21Z. ALTHOUGH THE DPVA AHD OF
THE SHRTWV AND ACCOMPANYING H85-5 QVECTOR CNVGC AS WELL AS THE
FAIRLY SHARP H85-7 FGEN ARE PROGGED TO PERSIST ALG THE FNT THRU THE
DAY...GFS/NAM SHOW THE STRONGER UPR DVGC/H7-3 QVECTOR DVGC/H85 MSTR
CNVGC FADING QUICKLY AFT 18Z AS THE H3 JET AXIS TRANSLATES FASTER E
THAN THE FNT AND THE STRONGER WINDS SPEEDS TEND TO LIFT NE. SO
ALTHOUGH SFC HTG/DESTABILIZATION MIGHT TEND TO ALLOW SOME PRE
FRONTAL SHRA/TSRA TO DVLP (COVG WL STILL BE LIMITED BY THE
CONVECTIVE TEMP OF 95 OBSVD ON THE 00Z MPX RAOB)...THE WDSPRD SHRA
ACTIVITY ON THE COOL SIDE OF THE BNDRY SHOULD TEND TO DIMINISH AFT
NOON. AS FOR TEMPS...PASSAGE OF BOTH FNTS WITH ACCOMPANYING INCRS IN
CLD/INFLUX OF COOLER AIR WL CAUSE UNSEASONABLY WARM TEMPS TO FALL
OFF...SO WL NEED A NON-DIURNAL TEMP CURVE TO SIMULATE DAYTIME TEMPS.
FOR TNGT...HI PRES IS FCST TO BLD INTO NRN ONTARIO IN THE HGT RISES/
DNVA IN THE WAKE OF THE DEPARTING SHRTWV. ALTHOUGH SUPPORT FOR
LARGER SCALE PCPN WL END WITH FLOW TENDING TOWARD ACYC...UPSLOPE NNE
FLOW WL CAUSE LO CLD TO LINGER IN AREAS DOWNWIND OF LK SUP. NAM FCST
SDNGS WOULD SUG DZ AS WELL...BUT UPSTREAM SFC DWPT DEPRESSIONS
BEHIND THE SECOND COLD FNT ARE RATHER HI IN EXCESS OF 10F UNDER THE
SC. ALTHOUGH PASSAGE OF THE AIRMASS OVER LK SUP MIGHT RESULT IN SOME
MOISTENING...PREFER THE GFS/LOCAL WRF-ARW FCST SHOWING ENUF LLVL DRY
AIR TO REMOVE MENTION OF DZ AND FOG. THE ONLY EXCEPTION WL BE OVER
THE HIER TERRAIN OF THE NCNTRL IN THE EVNG BEFORE ARRIVAL OF DRIER
LLVL AIR. EXPECT THE LOWEST MIN TEMPS OVER THE INTERIOR W WHERE LLVL
NE FLOW WL DOWNSLOPE. FCST MIN TEMPS INTO THE 30S IN THESE AREAS.
AS THE HI PRES RDG IN ONTARIO DRIFTS SLOWLY E ON SUN...THE LLVL FLOW
WL GRDLY VEER MORE ESE IN THE AFTN. SO PERSISTENT LO CLD IN THE NE
UPSLOPE AREAS SHOULD GRDLY DSPT WITH DCRSG TRAJECTORY/MODIFICATION
OVER LK SUP AS WELL AS SINKING SUBSIDENCE INVRN. MIXING TO H85 ON
GFS FCST SDNGS YIELDS HI TEMPS IN THE 60 TO 65 RANGE...BUT TENDED A
LTL COOLER WHERE NE VEERING E FLOW MAY MAINTAIN MORE SC LONGER.
NEXT SHRTWV DROPPING SEWD IN NW FLOW ALF IS FCST TO APRCH INL BY 12Z
MON...WITH ATTENDANT LO PRES TROF NEARING WRN LK SUP. GFS/NAM/UKMET
SHOW SOME FAIRLY IMPRESSIVE H5 HGT FALLS ARPCHG 100M DURING THE NGT
IN FAIRLY SHARP DPVA/DEEP LYR H85-3 QVECTOR CVNGC AHEAD OF THE
SHRTWV. BUT FAIRLY LIMITED MSTR SHOWN IN FCST SDNGS WARRANTS NO MORE
THAN THE GOING 20-30 POP...HIEST OVER THE W. ARRIVAL OF THE DYNAMICS
DURING MIN HTG TIME ALSO WARRANTS REMOVAL OF TS MENTION AS EVEN THE
MOISTER NAM SHOWS MUCAPE NO MORE THAN 200 J/KG. EXPECT THE LOWEST
MIN TEMPS OVER THE INTERIOR E WHERE ANTECEDENT DRY AIRMASS WL LINGER
THE LONGEST.
AS SHRTWV DIGS INTO THE UPR GRT LKS ON MON...BUMPED UP POPS
ESPECIALLY OVER THE NRN TIER ZNS ON CYC SIDE OF SHRTWV TRACK WHERE
DRY SLOTTING WOULD BE LESS LIKELY. UPR JET SUPPORT/ENHANCED UPR DVGC
IN LEFT EXIT OF THIS FEATURE ARRIVES IN THE AFTN IN TANDEM WITH
DIURNAL HTG...SO WENT WITH THE HIEST POPS AND INCLUDED MENTION OF TS
THEN. ALTHOUGH DYNAMICS EXIT MON NGT...MAINTAINED HI CHC POPS NEAR
LK SUP WITH CYC NLY FLOW OFF THE WATER AND FALLING H85 TEMPS TOWARD
0C INDICATING POTENTIAL FOR LK EFFECT SHRA.
COORDINATED WITH APX/GRB/DLH.
&&
.AVIATION (FOR THE 06Z TAF ISSUANCE)...
CHALLENGING FCST SHAPING UP OVERNIGHT THRU THE MORNING HRS. PER
RADAR TRENDS...EXPECT TSRA AT KCMX TO TRANSITION TO -SHRA OVER THE
NEXT HR OR TWO. HOWEVER...CONDITIONS WILL BE DROPPING DOWN TO MVFR
IN A FEW HOURS AS RAIN HELPS TO GRADUALLY MOISTEN THE LOW LEVELS. IT
IS NOT OUT OF THE QUESTION FOR IFR CONDITIONS TO DEVELOP...BUT
CONFIDENCE IS TOO LOW AT THE MOMENT TO COMMIT TO ANYTHING OTHER THAN
PREVAILING MVFR. AFTER COLD FROPA SAT...INFLUX OF SHALLOW COLD AIR
SHOULD RESULT IN IFR CIGS DEVELOPING AT KCMX FOR A FEW HRS. SOME
IMPROVEMENT TO MVFR EXPECTED LATE SAT AFTN. AT KSAW...CURRENT VAD
WIND PROFILE FROM KMQT RADAR INDICATES LLWS OCCURRING. THAT SHOULD
END OVERNIGHT AS LOW-LEVEL JET WEAKENS. SHRA SHOULD BE SLOW TO REACH
KSAW...NOT ARRIVING UNTIL AFTER SUNRISE. MVFR CONDITIONS WILL
EVENTUALLY DEVELOP AFTER ONSET OF PCPN WITH A TRANSITION TO IFR IN
THE MID/LATE AFTN AFTER COLD FROPA. FAVORABLE UPSLOPING N WIND
SHOULD MAINTAIN IFR CONDITIONS THRU THE END OF THE FCST PERIOD.
&&
.MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)...
COLD FRONT MOVING OFF OF THE MN ARROWHEAD WILL CROSS LAKE SUPERIOR
TODAY. BEHIND THE FRONT...A PERIOD OF NORTH WINDS TO 30 KT IS
EXPECTED ON THE EASTERN TWO THIRDS OF LAKE SUPERIOR...WHICH SHOULD
GRADUALLY DIMINISH ON SUN DUE TO THE PRESSURE GRADIENT RELAXING FROM
HIGH PRESSURE CROSSING NORTHERN ONTARIO. AS THE HIGH SHIFTS EAST SUN
NIGHT...LOW PRESSURE IS EXPECTED TO DROP SE OUT OF NW ONTARIO...
CROSSING LAKE SUPERIOR ON MON. SE WINDS ON EASTERN LAKE SUPERIOR ON
THE EAST SIDE OF THE LOW MAY REACH 25 KT SUN NIGHT AND MON. IN THE
WAKE OF THE LOW MON NIGHT AND TUE...EXPECT NW TO NORTH WINDS TO
INCREASE TO UP TO 25 KT...STRONGEST ON EASTERN LAKE SUPERIOR.
FORECAST BECOMES MUCH MORE UNCERTAIN BEYOND TUE. HOWEVER...IT DOES
APPEAR A COLD FRONT WILL BE DROPPING SOUTH ACROSS LAKE SUPERIOR
EITHER WED OR THU...WITH UP TO 30 KT NW WINDS POSSIBLE BEHIND THE
FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...NONE.
LAKE SUPERIOR...NONE.
LAKE MICHIGAN...NONE.
&&
$$
DISCUSSION...KC
AVIATION...ROLFSON
MARINE...AJ
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1007 AM MDT SAT SEP 27 2008
.UPDATE...
ADDED SHOWERS AND THUNDERSTORMS TO THE FORECAST FOR THE NORTHWEST
PLATEAU FOR THE REMAINDER OF TODAY IN RESPONSE TO RECENT SATELLITE
AND RADAR TRENDS. ALSO ADDED A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS FROM RATON THROUGH CLAYTON...WHERE A BACK DOOR FRONT
IN COLORADO COULD TRIGGER A FEW SHOWERS AND THUNDERSTORMS IF IT
MAKES IT THIS FAR SOUTH THIS AFTERNOON. FURTHERMORE...INCREASED
SKYCOVER TO PARTLY CLOUDY AREAWIDE FOR THE REMAINDER OF TODAY BASED
ON SATELLITE TRENDS. 44
&&
.PREV DISCUSSION...
301 AM MDT SAT SEP 27 2008...ONLY MINOR CHANGES MADE TO ONGOING
FORECAST PACKAGE. LATEST SURFACE OBS SHOW A FRONTAL BOUNDARY OVER
THE FAR NE PLAINS SAGGING SLOWLY SOUTH ALONG THE EAST SLOPES OF THE
SANGRES. WATER VAPOR LOOP SHOWS AN UPPER WAVE OVER THE NORTHERN
PLAINS WITH A MID LEVEL BOUNDARY EXTENDING SW ACROSS THE CENTRAL
PLAINS INTO THE SOUTHERN ROCKIES...A SHEARED UPPER WAVE CHURNING
OVER SE AZ/SE NM...AND DRY MID/UPPER LEVEL AIR OVER TEXAS BENEATH
THE UPPER RIDGE. 400-250MB AIRCRAFT WIND PLOT SHOWS A 50 KNOT JET
ASSOCIATED WITH THE UPPER WAVE NEAR THE GILA. SHORT-TERM MODEL
GUIDANCE INCLUDING THE RUC13 AND THE PREFERRED 00Z GFS INDICATE THE
DRY AIR OVER TEXAS WILL ADVANCE WESTWARD INTO NM THIS AFTERNOON AS
THE 700MB HIGH BUILDS OVER SW KANSAS...CREATING STABLE CONDITIONS
OVER MUCH OF THE EASTERN PLAINS. THE TUCUMCARI AND GRANADA PROFILERS
DO INDICATE WINDS HAVE SHIFTED TO THE NE ACROSS THIS AREA. AS A
RESULT...HAVE LEFT ISOLD SHOWERS ACROSS THE CENTRAL AREAS THIS
MORNING AND REMOVED THEM FOR THIS AFTERNOON AS STABLE AIR WILL MOVE
WEST INTO THE REGION TODAY. BEST CHANCE FOR PRECIP WILL BE OVER THE
NORTHERN MTNS IN ASSOCIATION WITH THE MID LEVEL BOUNDARY...AND OVER
THE FAR WEST/SOUTHWEST AREAS BENEATH THE SHEARED UPPER WAVE.
SUNDAY WILL BE A NEAR REPEAT OF TODAY...WITH SLIGHTLY LESS STORM
COVERAGE ACROSS THE REGION AS CONTINUED DRIER AND STABLE AIR MOVES
WEST ACROSS THE STATE. MEDIUM-RANGE GUIDANCE IS IN GOOD AGREEMENT...
WITH SUPPORT FROM ENSEMBLES...THAT THE RIDGE WILL AMPLIFY SLOWLY
WESTWARD OVER NM THROUGH THURSDAY AS A LARGE SCALE UPPER LOW BUILDS
OVER THE EASTERN PACIFIC/GULF OF ALASKA REGION. THIS WILL LEAD TO
GENERALLY TRANQUIL CONDITIONS WITH MODEST OVERNIGHT TEMPERATURE
INVERSIONS AND ABOVE NORMAL AFTERNOON HIGHS. EXTENDED GUIDANCE IS
BEGINNING TO SLOW THE PROGRESSION OF THE LARGE SCALE UPPER LOW
MOVING EAST AND BREAKING THE DOWN THE RIDGE BY THE WEEKEND. THIS
WILL DELAY THE ONSET OF ANY INCREASES IN SURFACE WINDS AND PRECIP
CHANCES ACROSS THE REGION...HOWEVER LEFT EXTENDED GRIDS UNCHANGED
TO AWAIT BETTER CONSISTENCY.
GUYER
&&
.AVIATION...
VFR CONDITIONS PREVAILING THROUGH 21Z. LOOK FOR ISOLATED CONVECTION
ALONG AND WEST OF CONTDVD AS WELL AS OVER THE NORTHERN MOUNTAINS AND
ALONG THE COLORADO BORDER TODAY. THE CONVECTION SHOULD BE HIGH
BASED WITH WIND GUSTS TO 35 MPH MORE LIKELY THAN HEAVY RAINFALL.
NEXT AVIATION DISCUSSION SCHEDULED FOR 21Z.
&&
.FIRE WEATHER...
WEAK SURFACE WIND SHIFT OVER NORTHEAST NEW MEXICO TODAY WILL LIKELY
NOT RESULT IN A SIGNIFICANT INCREASE IN HUMIDITIES ACROSS THAT PART
OF THE STATE...BUT THE BOUNDARY MAY SERVE AS A FOCUS FOR ISOLATED
CONVECTION TODAY. OTHERWISE...UPPER HIGH WILL REMAIN IN PLACE OVER
THE REGION THROUGH THE MIDDLE OF NEXT WEEK. WINDS AT MOUNTAIN TOP
LEVELS MAY BECOME MORE EASTERLY TODAY AND SOUTHEAST TONIGHT AS THE
HIGH CENTER WOBBLES INTO SOUTHEAST COLORADO.
THE PRIMARY CONCERN WILL CONTINUE TO BE THE POTENTIAL FOR ERRATIC
WIND GUSTS TO 35 OR 40 MPH FROM ISOLATED MAINLY AFTERNOON AND
EVENING HIGH BASED SHOWERS AND THUNDERSTORMS ACROSS NORTHERN AND
WESTERN NEW MEXICO. SUNDAY MAY BE SLIGHTLY MORE STABLE AND DRIER
ALOFT...THEREFORE SHOWERS AND STORMS MAY BE LESS ACTIVE THAN WHAT
IS ANTICIPATED TODAY...BUT SHOULD STILL BE CONFINED TO THE WEST
AND NORTH.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
44
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
301 AM MDT SAT SEP 27 2008
.DISCUSSION...
ONLY MINOR CHANGES MADE TO ONGOING FORECAST PACKAGE. LATEST SURFACE
OBS SHOW A FRONTAL BOUNDARY OVER THE FAR NE PLAINS SAGGING SLOWLY
SOUTH ALONG THE EAST SLOPES OF THE SANGRES. WATER VAPOR LOOP SHOWS
AN UPPER WAVE OVER THE NORTHERN PLAINS WITH A MID LEVEL BOUNDARY
EXTENDING SW ACROSS THE CENTRAL PLAINS INTO THE SOUTHERN ROCKIES...
A SHEARED UPPER WAVE CHURNING OVER SE AZ/SE NM...AND DRY MID/UPPER
LEVEL AIR OVER TEXAS BENEATH THE UPPER RIDGE. 400-250MB AIRCRAFT
WIND PLOT SHOWS A 50 KNOT JET ASSOCIATED WITH THE UPPER WAVE NEAR
THE GILA. SHORT-TERM MODEL GUIDANCE INCLUDING THE RUC13 AND THE
PREFERRED 00Z GFS INDICATE THE DRY AIR OVER TEXAS WILL ADVANCE
WESTWARD INTO NM THIS AFTERNOON AS THE 700MB HIGH BUILDS OVER SW
KANSAS...CREATING STABLE CONDITIONS OVER MUCH OF THE EASTERN PLAINS.
THE TUCUMCARI AND GRANADA PROFILERS DO INDICATE WINDS HAVE SHIFTED
TO THE NE ACROSS THIS AREA. AS A RESULT...HAVE LEFT ISOLD SHOWERS
ACROSS THE CENTRAL AREAS THIS MORNING AND REMOVED THEM FOR THIS
AFTERNOON AS STABLE AIR WILL MOVE WEST INTO THE REGION TODAY. BEST
CHANCE FOR PRECIP WILL BE OVER THE NORTHERN MTNS IN ASSOCIATION
WITH THE MID LEVEL BOUNDARY...AND OVER THE FAR WEST/SOUTHWEST AREAS
BENEATH THE SHEARED UPPER WAVE.
SUNDAY WILL BE A NEAR REPEAT OF TODAY...WITH SLIGHTLY LESS STORM
COVERAGE ACROSS THE REGION AS CONTINUED DRIER AND STABLE AIR MOVES
WEST ACROSS THE STATE. MEDIUM-RANGE GUIDANCE IS IN GOOD AGREEMENT...
WITH SUPPORT FROM ENSEMBLES...THAT THE RIDGE WILL AMPLIFY SLOWLY
WESTWARD OVER NM THROUGH THURSDAY AS A LARGE SCALE UPPER LOW BUILDS
OVER THE EASTERN PACIFIC/GULF OF ALASKA REGION. THIS WILL LEAD TO
GENERALLY TRANQUIL CONDITIONS WITH MODEST OVERNIGHT TEMPERATURE
INVERSIONS AND ABOVE NORMAL AFTERNOON HIGHS. EXTENDED GUIDANCE IS
BEGINNING TO SLOW THE PROGRESSION OF THE LARGE SCALE UPPER LOW
MOVING EAST AND BREAKING THE DOWN THE RIDGE BY THE WEEKEND. THIS
WILL DELAY THE ONSET OF ANY INCREASES IN SURFACE WINDS AND PRECIP
CHANCES ACROSS THE REGION...HOWEVER LEFT EXTENDED GRIDS UNCHANGED
TO AWAIT BETTER CONSISTENCY.
GUYER
&&
.AVIATION...
VFR CONDITIONS PREVAILING THROUGH 21Z. LOOK FOR ISOLATED CONVECTION
ALONG AND WEST OF CONTDVD AS WELL AS OVER THE NORTHERN MOUNTAINS AND
ALONG THE COLORADO BORDER TODAY. THE CONVECTION SHOULD BE HIGH
BASED WITH WIND GUSTS TO 35 MPH MORE LIKELY THAN HEAVY RAINFALL.
NEXT AVIATION DISCUSSION SCHEDULED FOR 21Z.
&&
.FIRE WEATHER...
WEAK SURFACE WIND SHIFT OVER NORTHEAST NEW MEXICO TODAY WILL LIKELY
NOT RESULT IN A SIGNIFICANT INCREASE IN HUMIDITIES ACROSS THAT PART
OF THE STATE...BUT THE BOUNDARY MAY SERVE AS A FOCUS FOR ISOLATED
CONVECTION TODAY. OTHERWISE...UPPER HIGH WILL REMAIN IN PLACE OVER
THE REGION THROUGH THE MIDDLE OF NEXT WEEK. WINDS AT MOUNTAIN TOP
LEVELS MAY BECOME MORE EASTERLY TODAY AND SOUTHEAST TONIGHT AS THE
HIGH CENTER WOBBLES INTO SOUTHEAST COLORADO.
THE PRIMARY CONCERN WILL CONTINUE TO BE THE POTENTIAL FOR ERRATIC
WIND GUSTS TO 35 OR 40 MPH FROM ISOLATED MAINLY AFTERNOON AND
EVENING HIGH BASED SHOWERS AND THUNDERSTORMS ACROSS NORTHERN AND
WESTERN NEW MEXICO. SUNDAY MAY BE SLIGHTLY MORE STABLE AND DRIER
ALOFT...THEREFORE SHOWERS AND STORMS MAY BE LESS ACTIVE THAN WHAT
IS ANTICIPATED TODAY...BUT SHOULD STILL BE CONFINED TO THE WEST
AND NORTH.
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 83 51 82 50 / 20 10 10 10
GALLUP.......................... 80 43 80 39 / 20 10 10 5
GRANTS.......................... 81 41 81 40 / 10 5 10 5
GLENWOOD........................ 81 48 81 49 / 20 10 5 5
CHAMA........................... 74 36 73 34 / 30 20 20 20
LOS ALAMOS...................... 74 47 74 44 / 10 5 5 5
RED RIVER....................... 69 33 68 30 / 20 10 20 10
TAOS............................ 76 41 74 39 / 10 10 10 10
SANTA FE........................ 78 44 78 44 / 10 5 5 5
SANTA FE AIRPORT................ 81 46 80 46 / 10 5 5 5
ESPANOLA........................ 82 42 81 41 / 10 5 5 5
ALBUQUERQUE HEIGHTS............. 81 56 80 55 / 10 0 5 0
ALBUQUERQUE VALLEY.............. 83 54 82 53 / 10 0 5 0
ALBUQUERQUE FOOTHILLS........... 79 52 79 52 / 10 5 5 5
ALBUQUERQUE WEST MESA........... 83 52 82 52 / 10 5 5 5
SOCORRO......................... 83 49 81 49 / 5 0 0 0
SANDIA PARK/CEDAR CREST......... 76 41 74 41 / 10 5 5 5
MORIARTY/ESTANCIA............... 78 41 77 39 / 5 0 0 0
CARRIZOZO....................... 80 47 80 46 / 5 5 0 0
RUIDOSO......................... 71 43 72 40 / 5 5 0 5
RATON........................... 80 41 81 40 / 10 5 0 5
LAS VEGAS....................... 75 43 75 42 / 10 5 5 5
ROY............................. 80 50 79 48 / 5 5 0 5
CLAYTON......................... 83 53 82 53 / 5 0 0 5
SANTA ROSA...................... 82 51 82 50 / 0 0 0 0
TUCUMCARI....................... 85 52 85 53 / 0 0 0 5
FORT SUMNER..................... 84 50 83 49 / 0 0 0 0
CLOVIS.......................... 82 53 80 53 / 0 0 0 0
PORTALES........................ 83 51 82 51 / 0 0 0 0
ROSWELL......................... 83 52 84 52 / 0 0 0 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
GUYER/99
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