AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
230 PM PDT FRI OCT 5 2007
.SYNOPSIS...
UPPER LEVEL LOW PRESSURE WILL CONTINUE LOCAL STRONG GUSTY WINDS
THROUGH THIS EVENING. HIGH PRESSURE ALOFT AND OFFSHORE FLOW WILL
BRING CLEAR SKIES AND WARMING THIS WEEKEND WITH LOCAL GUSTY WINDS
THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES. A LITTLE COOLER WITH
AREAS OF COASTAL LOW CLOUDS AND FOG IN THE NIGHTS AND MORNINGS
TOWARD THE SECOND HALF OF NEXT WEEK.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY-MON)...
SKIES WERE MOSTLY CLOUDY W OF THE MOUNTAINS AND IN THE HIGH DESERTS
THIS MORNING WITH A FEW LIGHT SHOWERS. CLOUDS WERE BACKUP UP ONTO
THE MOUNTAINS SLOPES BUT WERE GENERALLY DECREASING THIS AFTERNOON.
ACARS SOUNDINGS INDICATE VERY WEAK OR NO INVERSION IN THE LOW LEVELS
WITH STRONG SW WINDS ALOFT. ONSHORE GRADIENTS WITH ABOUT 7 MB
SAN-IPL AND 9 MB SAN-TPH AND THERE WERE LOCAL MODERATELY STRONG
GUSTY WINDS IN THE MOUNTAINS AND DESERTS.
THE PASSING TROUGH WITH INCREASING WINDS ALOFT AND ONSHORE GRADIENTS
WILL CAUSE LOCAL STRONG GUSTY WINDS INTO THIS EVENING...ESPECIALLY
IN THE MOUNTAINS AND DESERTS. CLOUDS WILL CONTINUE TO DECREASE THIS
EVENING. THE FLOW WILL START TO TURN OFFSHORE FROM THE N LATE
TONIGHT AND SAT AND THEN COME FROM A MORE NE TO E DIRECTION SUN.
THERE WILL BE A LITTLE UPPER SUPPORT FOR N WINDS SAT BUT BETTER
OFFSHORE GRADIENTS SUN. THIS WILL CAUSE LOCAL GUSTY N TO NE
WINDS...MAINLY THROUGH AND BELOW MOUNTAIN CANYONS AND PASSES. THERE
COULD BE LOCAL WINDS TO NEAR ADVISORY STRENGTH...MAINLY BELOW THE
CAJON PASS SAT AND SUN MORNINGS SHIFTING TO THE SAN DIEGO MOUNTAINS
SUN AFTERNOON. HIGH PRESSURE WILL ALSO BUILD ALOFT LATE SAT AND SUN.
THE DRY OFFSHORE FLOW WILL BRING GENERALLY CLEAR SKIES AND WARMER
WEATHER...ESPECIALLY SUN. THE HIGH ALOFT AND OFFSHORE FLOW WILL
WEAKEN FOR LESS WINDS BUT ONLY MINOR TEMP CHANGES.
THE FIRE WEATHER HAZARD WILL INCREASE SUN DUE TO LOW HUMIDITIES AND
LOCAL GUSTY WINDS IN THE MOUNTAINS AND INLAND VALLEYS.
&&
.LONG TERM (TUE-FRI)...
DRY WLY FLOW ALOFT WILL CONTINUE FAIR WEATHER. ONSHORE FLOW WILL
INCREASE TOWARD THE END OF NEXT WEEK FOR A RETURN OF MARINE LAYER
CLOUDINESS AND A LITTLE COOLING.
&&
.AVIATION...
051935Z...LATE MORNING MDCRS SOUNDINGS INDICATE THE MARINE LAYER HAS
BEEN DISRUPTED WITH A HINT OF AN INVERSION AROUND 6000 FEET NEAR
KSAN. A LAYER OF SCATTERED TO BROKEN STRATOCU WITH BASES BETWEEN
3500 AND 4500 FEET MSL SHOULD BECOME SCATTERED BY EVENING EXCEPT
REMAINING BROKEN AGAINST THE COASTAL SLOPES OF THE MOUNTAINS.
MOUNTAINS AND OTHER HIGH TERRAIN SHOULD REMAIN MOSTLY OBSCURED
THROUGH THE NIGHT. MOST AREAS SHOULD SCATTER OUT ON SATURDAY.
STRONG WEST TO NORTHWEST WINDS ACROSS THE MOUNTAINS WILL BRING
MOUNTAIN WAVE AND ROTOR ACTIVITY THE VICINITY OF KPSP AND KTRM AS
WELL AS L08 THROUGH THIS EVENING. WIND SHOULD BECOME MORE
NORTHWESTERLY TO NORTH BY SATURDAY MORNING AND COULD BE GUSTY BELOW
MOUNTAIN PASSES AND CANYONS SATURDAY MORNING. STRONGER OFFSHORE
WINDS ARE EXPECTED BELOW THE MOUNTAIN PASSES AND CANYONS SUNDAY
MORNING WITH ASSOCIATED UP AND DOWN DRAFTS AND LOW LEVEL WIND
SHEAR. HORTON
&&
.MARINE...
SMALL CRAFT ADVISORY FOR THE COASTAL WATERS OFF SAN DIEGO COUNTY
TODAY THROUGH THIS EVENING. WINDS OF 15 TO 25 KT WITH GUSTS TO 30 KT
THROUGH THIS EVENING. WINDS INCREASING NEAR THE COAST THIS MORNING.
A STEEP NORTHWEST WIND SWELL WILL MOVE THROUGH TODAY. SEAS WILL BE
QUITE CHOPPY. THE WIND SWELL WILL MOVE THROUGH QUICKLY AND PROBABLY
BE GONE BY SATURDAY MORNING.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FOR ALL AREAS THROUGH 7 PM AND CONTINUING IN THE
HIGHER MOUNTAINS AND FOR THE DESERTS UNTIL 9 PM. SEE LAXNPWSGX.
SMALL CRAFT ADVISORY UNTIL 11 PM PDT. SEE LAXCWFSGX.
FIRE WEATHER WATCH FOR THE MOUNTAINS AND INLAND VALLEYS SUNDAY. SEE
LAXRFWSGX.
&&
$$
PUBLIC...DVA
AVIATION/MARINE...HORTON
AREA FORECAST DISCUSSION
NWS GAYLORD MI
354 PM EDT FRI OCT 5 2007
.DISCUSSION...ANOTHER VERY NICE EARLY OCTOBER DAY IN PROGRESS ACROSS
ALL OF NORTHERN MICHIGAN...WITH AFTERNOON TEMPERATURES WELL ABOVE
AVERAGE BY SOME 10 TO 15 DEGREES. THE CULPRIT (THOUGH HARD TO CALL
IT THAT) IS EXPANSIVE LOW AND MID LEVEL RIDGING BUILDING THROUGHOUT
THE EASTERN CONUS IN RESPONSE TO UNSEASONABLY DEEP TROUGHING JUST
INLAND FROM THE PACIFIC COAST. IN BETWEEN THESE TWO SYSTEMS...DEEP
SOUTHWESTLY FLOW CONTINUES...WITH SEVERAL WEAK SHORTWAVES OF NOTE
RIDING THROUGH THE FLOW. ALL THE WHILE...WARM FRONTOGENESIS TAKING
SHAPE ACROSS THE UPPER MIDWEST AND INTO THE UPPER PENINSULA IN
RESPONSE TO LEE CYCLOGENESIS BEGINNING OVER THE CENTRAL HIGH PLAINS
AS WELL AS EXPANSIVE (AND RATHER COLD) LOW LEVEL RIDGE ADVANCING
FROM EASTERN SASKATCHEWAN THROUGH ONTARIO...AIDING IN A RAPID
TIGHTENING OF THE SFC-850 THERMAL GRADIENT. THESE WEATHER FEATURES
WILL COME INTO PLAY THROUGHOUT THE NIGHT REGARDING PRECIPITATION
POTENTIAL...WITH PRECIP CHANCES THIS EVENING INTO TOMORROW AFTERNOON
BEING THE MAIN SHORT TERM FORECAST CONCERN THIS GO AROUND.
DESTABILIZATION NOW UNDERWAY ACROSS THE AREA...WITH TEMPS CLIMBING
THROUGH THE 70S AND LOWER 80S...AND DEW POINTS HEADED UPWARD AS WELL
(LOW/MID 60S COMMON SOUTH OF THE STRAITS. HOWEVER...MORNING RAOBS AS
WELL AS RECENT TAMDAR SOUNDINGS SUGGEST CAPPING STILL IN PLACE
AROUND 600MB. HOWEVER...AS FURTHER HEATING TAKES PLACE BY LATE
AFTERNOON...ANTICIPATE A FEW SHOWERS (AND PERHAPS STORMS WITH 82/62
PARCEL GIVING ABOUT 700 J/KG MLCAPE JUST SCRAPING BY RESIDUAL
INVERSION) WILL DEVELOP...PRIMARILY SOUTH OF A CVX-APN LINE IN BEST
PROXIMITY TO INCREASING LOW LEVEL CONVERGENCE AND MOISTURE.
HOWEVER...THESE LIKELY TO BE SOMEWHAT SHORT-LIVED AS THE MAIN ACTION
LOOKS TO TAKE OFF TO THE NORTH...WITH DEVELOPING LOW LEVEL JET OF
35-40 KNOTS PRODUCING EXCELLENT LIFT OVER VERY TIGHT SFC-850MB
THERMAL GRADIENT IN THE PRESENCE OF STEEPENING LOW-MID LEVEL LAPSE
RATE PLUME. COUPLED WITH DEEP MOISTURE (UPSTREAM PWATS IN EXCESS OF
1.5 INCHES) AND ADDITIONAL FORCED ASCENT IN ASSOCIATION WITH
SHORTWAVE CURRENTLY PUSHING THROUGH EASTERN MINNESOTA...A HEAVY RAIN
EVENT LOOKS TO BE IN THE WORKS NORTH OF THE NEARLY STATIONARY LOW
LEVEL WARM FRONT OVERNIGHT. HOWEVER...PER MODEL DEPICTIONS OF BEST
JET FORCING AND PLACEMENT OF THE LOW LEVEL BOUNDARY THIS
AFTERNOON...IT APPEARS THAT THE MAJORITY OF THE ACTION WILL TAKE
PLACE JUST NORTH OF THE CWA (OVER LAKE SUPERIOR?) TONIGHT. THIS WILL
CERTAINLY NEED TO BE WATCHED THROUGH THE EVENING HOURS...BUT WILL
HOLD WITH JUST HIGH CHANCE POPS FOR THE NORTH...TAPERING TO PRETTY
MUCH NOTHING OVER THE SOUTH GIVEN LACK OF ANY PRONOUNCED FORCING
MECHANISM.
HEADING INTO THE DAY TOMORROW...APPEARS THE WARM FRONT WILL ATTEMPT
TO BEGIN TO LIFT NORTHWARD IN RESPONSE TO RISING HEIGHTS AS THE
EASTERN RIDGE CONTINUES TO AMPLIFY. HOWEVER...DEGREE/PLACEMENT OF
CONVECTION AS WELL AS COLD LAKE SUPERIOR AND PLACEMENT OF STRONG
(1030+ MB) HUDSON BAY HIGH WILL IN ALL LIKELIHOOD HOLD THE BOUNDARY
INTACT THROUGH MUCH OF THE DAY ACROSS EASTERN UPPER COUNTIES.
DESPITE THE DIURNAL VEERING OF THE LOW LEVEL JET BY MORNING...
APPEARS RESIDUAL WEAK 300-310K ISENTROPIC UPGLIDE IN THE PRESENCE OF
DEEP RH WILL RESULT IN CLOUDY SKIES UP NORTH ALONG WITH OCCASIONAL
SHOWERS THROUGH MID AFTERNOON. MEANWHILE ACROSS NORTHERN LOWER
COUNTIES...APPEARS INCREASED WARMING ALOFT/CAPPING THROUGH THE
AFTERNOON WILL YIELD A DRY DAY...THOUGH WILL OBVIOUSLY SEE AFTERNOON
CU FIRE UNDER WARM/HUMID CONDITIONS.
AS FOR OTHER THINGS...FOG ONCE AGAIN A CONCERN TONIGHT (LOOKS BETTER
THAN LAST NIGHT) GIVEN STRONG MOISTURE PUSH INTO THE CWA TODAY AND
LOW FOG STABILITY NUMBERS AFTER MIDNIGHT. GOING MENTION OVER THE
LAKES LOOKS GOOD AS WELL GIVEN LAKE TEMPS RUNNING FROM 58-63F AND
SFC DEW POINTS APPROACHING 3-5F ABOVE THESE VALUES.
TEMPERATURE-WISE...A MILD NIGHT ON TAP WITH LIKELY PERIODIC LOW/MID
LEVEL CLOUDS AND HIGH DEW POINTS RESULTING IN NUMBERS CLOSE TO
AVERGE HIGHS THIS TIME OF YEAR - MAINLY UPPER 50S TO MIDDLE 60S. FOR
HIGHS ON SATURDAY...UPSTREAM READINGS AGAIN GIVE A GOOD FIRST
GUESS...WITH H85 TEMPS PROGGED AROUND 16C SUGGESTING HIGHS BACK IN
THE UPPER 70S TO LOWER 80S. THE EXCEPTION WILL BE NORTH OF THE
STRAITS WHERE EXPECT CLOUDS/SOME PRECIP TO LINGER (SEE
ABOVE)...LIKELY HOLDING HIGHS ONLY IN THE 60S...THOUGH CERTAINLY
SOME ROOM TO CLIMB HIGHER PENDING ANY LATE AFTERNOON SUNSHINE.
LAWRENCE
LONG TERM...THERE ARE SOME INTERESTING THINGS WITH THE LONG TERM AS
THE MODELS TEND TO SPREAD ESPECIALLY AS WE GET INTO THE EXTENDED. IN
THE MID TERM, THE ECMWF, THE GFS, AND TO SOME EXTENT THE NAM AGREE
OUT THROUGH 72 HOURS. THE UKMET TRIES TO FORCE THE 500 MB WAVE
THROUGH FASTER WHICH IS THE OUTLIER. THE ECMWF AND THE GFS ARE IN
GOOD AGREEMENT AT 72 HOURS WITH THE NAM A BIT OUT OF PHASE WITH THE
OTHER TWO, SO LEANED TO THE GFS FORECAST FOR THE PACKAGE. THE MAIN
CONCERN IN THE LONG TERM IS THE TEMPERATURES SUNDAY AND THE ONSET OF
RAIN SUNDAY NIGHT. IN THE EXTENDED THE CONCERN IS THE CESSATION OF
RAIN, WHICH MIGHT HAPPEN ON THURSDAY OR FRIDAY NEXT WEEK. THIS WILL
DEPEND ON THE EVOLUTION OF THE CUTOFF LOW MOVING INTO THE GREAT
LAKES, OF WHICH THERE ARE SEVERAL SOLUTIONS.
SATURDAY NIGHT...SINCE I AM LEANING TOWARD THE GFS, CONTINUED THE
ESSENTIALLY DRY FORECAST IN E UPPER AS THE 500 MB RIDGE KEEPS THINGS
JUST TO THE NORTH IN ONTARIO. THE 700-500 MB RH IS LESS THAN 50%
THROUGH THE NIGHT AND THE GFS HAS LESS MOISTURE AT 850 MB (LESS THAN
80% AT 12 VS. THE NAM`S 98%) SO FIGURE THAT THERE WILL BE CLOUDS
AROUND THAT GRADUALLY THICKEN THE FARTHER NORTH YOU ARE.
SUNDAY...LEFT THE GOING FORECAST AS THE GFS (AND THE NAM FOR THAT
MATTER) CONTINUES WITH THE RAIN COMING IN AROUND 18Z AND SO A DRY
MORNING AND THEN A CHANCE OF RAIN SHOWERS FOR THE AFTERNOON AS THE
SFC TROUGH PUSHES INTO THE FORECAST AREA.
SUNDAY NIGHT...AS A SHORTWAVE DIGS INTO THE CUTOFF LOW AT 500 MB AND
DEVELOPS THE SFC LOW IN THE MISSISSIPPI, THE WARM FRONT SINKS A
LITTLE SOUTH AS A COLD FRONT AND CONTINUES TO PROVIDE RAIN CHANCES
FOR E UPPER AND NOW N LOWER, MAINLY NORTH OF A FKS TO APN LINE.
MONDAY...THE SFC LOW BEGINS ITS MOVES TO THE EAST, HOWEVER, WITH THE
DRY WARM SECTOR IN PLAY IN THE MORNING, KEPT THE RAIN OUT SOUTH OF
M-72. THEN AS THE LOW MOVES NORTHEAST, THE FRONT PUSHES THE RAIN
CHANCES NORTH OF M-32.
MONDAY NIGHT...HAVE STARTED THE EVENING WITH LOW CHANCE POPS
EVERYWHERE AS THE 500 MB LOW APPROACHES AND THE SFC LOW BEGINS TO
ELONGATE ALONG THE BAROCLINIC ZONE. AFTER 06Z, IT LOOKS LIKE THE
COLD FRONT TO THE WEST MOVES THROUGH THE FORECAST AREA. THIS IS A
DAY3/DAY4 TIME FRAME, SO KEPT THE POPS IN THE CHANCE CATEGORY FOR
NOW, ALTHOUGH I COULD SEE THIS AS A LIKELY EVENT FOR THE OVERNIGHT
HOURS INTO TUESDAY.
EXTENDED (TUESDAY THRU FRIDAY)...TUESDAY, THE COLD FRONT PASSES
THROUGH AND THE 500 MB LOW IS TO THE WEST OF THE FORECAST AREA. SO
CLOUDY SKIES AND RAIN, PROBABLY IN THE FORM OF SHOWERS. WITH THE LOW
SLOWLY FILLING, WEDNESDAY THE SFC LOW IS OVER THE REGION AND WOULD
EXPECT THAT THE INSTABILITY WOULD BE DONE AND JUST RAIN WOULD BE
OVER THE REGION. THURSDAY, THE 500 MB WAVE IS OPENING AND THE SFC
WAVE IS WEAKENING QUITE A BIT SO WOULD EXPECT THAT THERE IS A CHANCE
OF RAIN SHOWERS THAT LASTS INTO FRIDAY AS THE 500 MB PATTERN IS
FINALLY BEGINNING TO GO INTO ALMOST ZONAL FLOW BY THE END OF THE
DAY. SO WILL HAVE THE CHANCE FOR RAIN SHOWERS.
LUTZ
&&
.AVIATION... /ISSUED 111 PM EDT FRI OCT 5 2007/
ADVANCING LOW LEVEL MOISTURE LIFTING NORTHWARD OUT OF SRN LOWER
MICHIGAN COMBINED WITH SOME INSTABILITY WILL PROVIDE A RISK FOR
ISOLATED SHOWERS AND A RUMBLE OF THUNDER DURING THE AFTERNOON AND
INTO TONIGHT...MAINLY IMPACTING LOCATIONS NORTH OF M-72...BETTER
CHANCES FARTHER NORTH. CHANCES ARE SMALL ENOUGH TO LEAVE OUT OF
TAFS...BUT WILL HAVE TO AMEND BASED ON RADAR TRENDS. VSBYS ARE
EXPECTED TO FALL TO MVFR THIS EVENING AND IFR OVERNIGHT AS AREAS
OF FOG DEVELOPS BY EARLY MORNING. ANY LOWER VSBYS WILL IMPROVE TO
VFR BY MID-MORNING WITH ONLY MID-LEVEL CLOUDS OVERHEAD.
MPC
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1228 PM EDT FRI OCT 5 2007
LATEST UPDATE...AVIATION...
.SYNOPSIS...(406 AM EDT FRI OCT 5 2007)
HIGH PRESSURE CENTERED OVER THE EAST U.S. COAST AND THE WESTERN
ATLANTIC WILL HELP TO MAINTAIN SOUTHERLY FLOW OVER THE STATE THROUGH
THE WEEKEND AND INTO EARLY NEXT WEEK. THIS SOUTHERLY FLOW WILL HELP
TO KEEP WARM AIR IN PLACE AND INCREASE THE HUMIDITY ACROSS THE
REGION. HIGH TEMPERATURES ARE EXPECTED TO APPROACH...AND EVEN IN
SOME CASES EXCEED RECORDS OVER THE NEXT 4 DAYS.
&&
.SHORT TERM...(1125 AM EDT FRI OCT 5 2007)
THE MID LEVEL WARM ADVECTION CONTINUES INTO THE AFTERNOON. WATER
VAPOR...IR AND REGIONAL RADAR LOOPS CONTINUE TO SHOW THE WARMER AND
MORE MOIST AIR SOUTH OF MICHIGAN CONTINUES TO STREAM IN FROM THE
SOUTH. WHILE TAMDAR SOUNDINGS AND 12Z RAOBS SHOW A DECENT SUBSIDENCE
INVERSION AROUND 650 MB...WHICH WOULD CAP CONVECTION THE WARMING OF
THE LOWER LAYERS WILL CREATE ENOUGH INSTABILITY TO JUST BARELY BE
ABLE TO BREAK THROUGH THE CAP. USING AN INITIAL PARCEL OF 84F OVER
60F AT 21Z NEAR GRR... CLOUD TOPS WOULD BE NEAR 38000 FT... AND THE
EQUILIBRIUM LEVEL WOULD BE NEAR 28000 FT. GIVEN THE FREEZING LEVEL
WILL BE NEAR 15000 FT AND THE -20F IS NEAR 24000 FT...THAT WOULD
SUGGEST ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON. THESE
STORMS WILL BE PULSE STORMS AND GIVEN THE FEEBLE CAPE... I DO NOT
BELIEVE SEVERE STORMS ARE AN ISSUE. THUS I UPDATED THE ZONES TO
ALLOW FOR ISOLATED THUNDERSTORM THIS AFTERNOON OVER THE CWA.
MOST OF THEM MODELS SUGGEST THE MID LEVEL MOISTURE OVER NRN IN WILL
MIX OUT AS IT MOVES NORTH THIS AFTERNOON... SO THERE SHOULD STILL BE
ENOUGH SUN TO GET HIGHS INTO THE MID 80S. THUS MY ONLY SIGNIFICANT
CHANGE IN THE ZONES IS TO ADD ISOLATED THUNDERSTORMS THIS
AFTERNOON.
&&
.LONG TERM... (406 AM EDT FRI OCT 5 2007)
BIG CHANGES APPEAR TO BE IN THE OFFING DURING THE EXTENDED PERIOD OF
SUNDAY NIGHT THROUGH THURSDAY. THE PERIOD WILL START OFF SUNDAY
NIGHT AND MONDAY WITH RIDGING STILL HOLDING ON ALOFT...PROVIDING A
CONTINUATION OF THE WARM CONDITIONS FROM THE WEEKEND.
MODELS ARE IN A BIT MORE AGREEMENT THIS MORNING AS COMPARED TO
YESTERDAY REGARDING THE EVOLUTION OF THE UPPER PATTERN THIS UPCOMING
WEEK. IT LOOKS MORE AND MORE LIKE THE GFS WAS RIGHT YESTERDAY IN
LINGERING A TROUGH ALOFT OVER THE GREAT LAKES FOR MUCH OF NEXT WEEK.
THE CANADIAN GEM IS ON BOARD WITH THIS IDEA AND THE EUROPEAN SEEMS
TO BE COMING MORE IN LINE. HAVE SHOWERS AND STORMS MENTIONED MONDAY
AND TUESDAY WITH A FRONTAL BOUNDARY MOVING THROUGH THE AREA. UPPER
LOW LINGERS INTO MUCH OF THE REMAINDER OF THE WEEK AND MAINTAINED
THE MENTION OF SHOWERS TUESDAY NIGHT THROUGH THURSDAY.
TEMPERATURES WILL BEGIN WELL ABOVE NORMAL IN THE 80S ON MONDAY FOR
HIGHS...FADING INTO THE 60S FOR HIGHS BY MID TO LATE IN THE UPCOMING
WORK WEEK WHICH IS BACK TO NORMAL.
&&
.AVIATION...(1228 PM EDT FRI OCT 5 2007)
THE FEW SHOWERS THAT WERE OVER THE I94 CORRIDOR WERE CONTINUING TO
WEAKENING AND WILL MIX OUT BY 19-20Z. THESE WERE TOO ISOLATED TO
MENTION IN THE TAF. WE WILL REMAIN IN THE WARM ADVECTION CLOUD
COVER...BASES 5-7K FEET...INTO THE EVENING HOURS. EXPECTING MORE
HOLES TO DEVELOP IN THE CLOUDS TONIGHT AS THERE SHOULD BE A DIURNAL
COMPONENT TO THE CLOUD DECK. THE CLEARING SKIES WILL SET UP THE
POSSIBILITY OF RADIATIONAL FOG TO DEVELOP OVERNIGHT. WITH A BIT OF
A SOUTHERLY WIND AND STILL SOME CLOUDS AROUND EXPECT THE
VISIBILITIES TO BE LARGELY MVFR WITH SOME PATCHY IFR. THE FOG WILL
DIMINISH BY MID MORNING WITH A CU DECK FILLING IN.
&&
.MARINE...(1125 AM EDT FRI OCT 5 2007)
THE LATEST WEB CAMS SHOW WAVES UNDER 2 FEET AT THE BEACHES. GIVEN
THE LIGHT SOUTHERLY WINDS... I EXPECT WAVES FOR THE MOST PART TO
REMAIN A FOOT OR LESS IN THE NEAR SHORE WATERS THIS AFTERNOON AND
TONIGHT. SOUTH TO SOUTHEAST WINDS ARE EXPECTED TO CONTINUE THROUGH
THE REST OF THE WEEKEND OVER THE NEARSHORE AREAS. WINDS WILL
GENERALLY REMAIN AT OR BELOW 15 KNOTS THROUGH THAT PERIOD. WAVES
SHOULD REMAIN GENERALLY BELOW 3 FEET THROUGH THE PERIOD.
&&
.HYDROLOGY...(406 AM EDT FRI OCT 5 2007)
RIVER AND STREAM GAGE NETWORK SHOW LEVELS GENERALLY AT OR BELOW
NORMAL ACROSS THE AREA. THIS SHOULD CONTINUE THROUGH THE WEEKEND
WITH NO WIDESPREAD PRECIPITATION EXPECTED ACROSS THE AREA UNTIL NEXT
WEEK.
&&
.CLIMATE...
RECORDS FOR THE WEEKEND ARE AS FOLLOWS:
GRR: TODAY 10/5 - 85 IN 1946...1922...AND 1900
SAT 10/6 - 86 IN 1900
SUN 10/7 - 83 IN 1913
MKG: TODAY 10/5 - 80 IN 2005 AND 1946
SAT 10/6 - 82 IN 1900
SUN 10/7 - 80 IN 1949
LAN: TODAY 10/5 - 87 IN 1922 AND 1900
SAT 10/6 - 89 IN 1963
SUN 10/7 - 86 IN 1879
WE FEEL THAT MOST OF THESE RECORDS OVER THE NEXT THREE DAYS ARE IN
JEOPARDY OF FALLING. THE ONLY RECORDS WE FEEL THAT ARE SAFE ARE THE
RECORDS FOR LANSING FOR TODAY /87/ AND SAT /89/.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: NJJ
SHORT TERM: WDM
LONG TERM: DUKE
AVIATION: JK
MARINE: WDM
HYDROLOGY: NJJ
CLIMATE: NJJ
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
339 PM CDT FRI OCT 5 2007
.DISCUSSION...
NEAR TERM MODELS IN GOOD AGREEMENT AND HAVE GOOD CONFIDENCE IN THE
FORECAST. MAIN CONCERNS WILL BE WIND ON SATURDAY AND TIMING OF
FROPA SATURDAY. IN THE NEAR TERM HAVE LOOKED AT WV AND LIGHTNING
OVERLAY WITH A DISTURBANCE MOVING THROUGH THE 4 CORNERS AREA INTO
THE PANHANDLE. WAVE HAS LOST ITS PUNCH ONCE IT CROSSED THE DIVIDE.
MAY BE ENOUGH INTERACTION WITH BOUNDARY IN THE PANHANDLE BUT HAVE
LEFT DRY FOR NOW. MODELS NOT DIGGING WEST COAST SYSTEM AS DEEP
TODAY WITH UPPER JET DRIVING AROUND THE SYSTEM AND LIMITING ITS
SOUTHERN TRACK. YESTERDAYS MODELS HAD SYSTEM DRIVING INTO 4
CORNERS SAT 12Z NOW INTO THE SALT LAKE VICINITY BUT ALL IN GOOD
AGREEMENT. WITH SYSTEMS FURTHER NORTH WARD DRIFT SURFACE GRADIENT
SLOW TO TIGHTEN AND WINDS WILL BE BORDERLINE ADVISORY ON SATURDAY
WITH THE MOST LIKELY AREA TO BE NORTH CENTRAL ZONES. PW`S CONTINUE
ABOVE NORMAL WITH STRONG THETAE ADVECTION ACROSS SOUTHERN PLAINS
ON THE NOSE OF 50+KT LLJ OVERNIGHT INTO SATURDAY. HAVE DELAYED
ONSET OF PRECIPITATION IN THE NORTHWEST BUT INTRODUCED ISO POPS
ACROSS FORECAST AREA ALONG THE 850MB FRONT AND THE LLJ EARLY IN
THE AFTERNOON. FRONTAL PASSAGE WILL BE DELAYED TILL SATURDAY
EVENING AND HAVE GENERALLY FOLLOWED HPC QPF WITH SYSTEM AS IT
MOVES THROUGH WESTERN NEBRASKA SATURDAY EVENING. HAVE INCREASED
TEMPERATURES ON THE DAY SATURDAY. SETUP FOR SEVERE WEATHER AS
LINEAR SYSTEM MOVES INTO DEEP MOISTURE AND UPPER SUPPORT INDUCES
LIFT ACROSS THE AREA. MAIN THREAT LOOKS TO BE LARGE HAIL. AS H5
CLOSED LOW MOVES NORTHEAST LIFTING OVER WESTERN NEBRASKA SUNDAY A
STRONG WAVE WILL MOVE OUT OF THE SYSTEM WITH A SECONDARY AREA
THROUGH CENTRAL NEBRASKA WITH HEAVY RAIN SUNDAY AFTERNOON SUNDAY
EVENING BEFORE SYSTEM PULLS NORTHEAST. SOME UPPER 30S SUNDAY
MORNING OVER NORTHWEST PANHANDLE BUT SYSTEM NOT AS COLD.
PRECIPITATION ENDING MONDAY EVENING ACROSS WESTERN NEBRASKA WITH
TEMPERATURES REBOUNDING TUESDAY THROUGH FRIDAY AS SYSTEM DRIVING
INTO WEST COAST SHARPENS H5 RIDGE INTO CENTRAL PLAINS. DRY.
&&
.AVIATION...
VFR CONDITIONS SHOULD REMAIN IN PLACE ACROSS WESTERN NEBRASKA INTO
THE FRONT RANGE THROUGH THE NEXT 24 HOURS OR SO. STRENGTHENING LOW
PRESSURE ACROSS THE BLACK HILLS INTO EASTERN WYOMING WILL INCREASE
THE PRESSURE GRADIENT ACROSS WESTERN INTO CENTRAL NEBRASKA OVERNIGHT
LEAVING A SOMEWHAT MIX ENVIRONMENT IN PLACE...HOWEVER IF WINDS DO
DECREASE ENOUGH...A STRONG SOUTHWEST ORIENTED LLVL JET WILL LEAD TO
LOW LEVEL WIND SHEAR BY SUNRISE ON SUNDAY AS SFC WINDS WOULD BE
LIGHT AND BACKED TO THE EAST. THESE SAME WINDS WILL INCREASE THROUGH
THE DAY ON SATURDAY AS THEY MIX THE INVERSION OUT...WIND GUSTS OVER
35 MPH COULD BE POSSIBLE AND MAY BE HAZARD TO LIGHT AIRCRAFT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
POWER/13
|