SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
200 PM PDT SAT MAR 24 2007
.SHORT TERM (TODAY-MONDAY)...SATELLITE IMAGERY SHOWING VERY
DISORGANIZED MARINE LAYER COVERAGE THIS AFTERNOON...WITH GOOD
CLEARING ACROSS VENTURA COUNTY...BUT ONLY PARTIAL CLEARING ACROSS
PORTIONS OF LA BASIN AS WELL AS CENTRAL COAST AND SBA COUNTY SOUTH
COAST. EARLIER ACARS DATA AND PILOT REPORTS INDICATED A MARINE LAYER
DEPTH OVER 4000 FEET EARLIER THIS MORNING...BUT CURRENT DATA
SUGGESTS A DEPTH AROUND 2500 FEET. AS UPPER LEVEL RIDGE BUILDS OVER
AREA TONIGHT AND SUNDAY...LOOK FOR MARINE LAYER TO CONTINUE TO
SHRINK WITH TIME. NONTHELESS...WE SHOULD SEE SOME LOW CLOUDS AND FOG
RETURN TO SOME VALLEY AREAS OVERNIGHT. THE MARINE LAYER IS THEN
EXPECTED TO DEEPEN SOMEWHAT LATE SUNDAY NIGHT INTO MONDAY IN ADVANCE
OF THE NEXT UPPER LEVEL TROUGH. SLIGHT WARMING IN MANY AREAS
EXPECTED ON SUNDAY...WITH A FEW DEGREES OF COOLING EXPECTED ON
MONDAY.
NEXT STORM SYSTEM WILL BRING A THREAT OF RAIN AND MOUNTAIN SNOW TO
THE REGION ON MONDAY NIGHT INTO TUESDAY. AT THIS POINT...MODELS ARE
GENERALLY TRENDING TOWARDS BRINGING A NARROW BAND OF RAIN ASSOCIATED
WITH A FAST MOVING FRONTAL BAND INTO THE CENTRAL COAST ON MONDAY
EVENING...SPREADING RAPIDLY THROUGH VENTURA AND LA COUNTIES
OVERNIGHT MONDAY NIGHT. WHILE AVAILABLE MOISTURE IS LIMITED WITH
THIS SYSTEM...LATEST MODEL RUNS CONTINUE TO ADVERTISE FAIRLY GOOD
DYNAMICS AND COLD AIR ADVECTION. A STRONG 130 KNOT WESTERLY JET WITH
ASSOCIATED UPPER LEVEL DIVERGENCE COMBINED WITH A STRONG AREA OF PVA
SHOULD BE ABLE TO HOLD FRONTAL BAND TOGETHER ACROSS LA BASIN WHICH
CURRENT WRF MODEL CROSS SECTIONS CONTINUE TO ADVERTISE. BEHIND THE
MAIN FRONTAL BAND...THERE WILL BE A VERY COLD AND SLIGHTLY UNSTABLE
AIR MASS WHICH WILL BRING A THREAT OF SHOWERS AND EVEN A SLIGHT
CHANCE OF THUNDERSTORMS THROUGH TUESDAY...ALTHOUGH IT NOW APPEARS
THAT CLOUD COVERAGE AND PRECIPITATION CHANCES MAY DECREASE DURING
THE AFTERNOON HOURS. AT THIS POINT...STILL FEEL THAT BEST THREAT OF
PRECIPITATION WILL BE FROM SBA COUNTY NORTHWARD...AND HAVE BUMPED UP
POPS TO LIKELY CATEGORY IN THIS AREA...BUT WILL KEEP WITH CHANCE
POPS DOWN SOUTH FOR NOW UNTIL THERE IS GOOD RUN TO RUN MODEL
CONSISTENCY.
SINCE THIS SYSTEM WILL LIKELY BE MORE CONVECTIVE IN NATURE...THERE
WILL LIKELY BE WIDELY VARYING RAINFALL TOTALS...BUT IT IS QUITE
POSSIBLE THAT SOME AREAS COULD PICK UP BETWEEN ONE TENTH AND ONE
HALF INCH OF RAIN. THIS SYSTEM CERTAINLY HAS PLENTY OF COLD AIR
ALOFT WITH 500 MB TEMPERATURES PROGGED TO RANGE BETWEEN -25 AND -30
DEGREES CELSIUS LATE MONDAY NIGHT INTO TUESDAY MORNING. WITH THE
RAPID COLD AIR ADVECTION ALOFT...THERE COULD CERTAINLY BE A THREAT OF
THUNDERSTORMS WITH BRIEF HEAVY DOWNPOURS AND SMALL HAIL. VERY LOW
SNOW LEVELS WILL LIKELY BE THE MOST PROMINENT FEATURE OF THIS
SYSTEM...WITH SNOW LEVELS LIKELY FALLING TO BETWEEN 3000 AND 3500
FEET LATE MONDAY NIGHT INTO TUESDAY MORNING. MOUNTAIN AREAS COULD
SEE ANYWHERE BETWEEN 2 AND 4 INCHES OF NEW SNOW WITH THIS SYSTEM.
THESE LOW SNOW LEVELS COULD BRING ACCUMULATING SNOW TO THE FOOTHILLS
OF THE CUYAMA AND ANTELOPE VALLEYS...AS WELL AS INTERSTATE 5 NEAR THE
GRAPEVINE. ANOTHER INTERESTING FEATURE WITH THIS STORM COULD BE
GUSTY WEST WINDS BEHIND THE FRONT LATE MONDAY NIGHT INTO TUESDAY.
.LONG TERM (WEDNESDAY-SATURDAY)...CLEARING SKIES SHOULD SPREAD ACROSS
THE AREA TUESDAY NIGHT INTO WEDNESDAY. WHILE TEMPERATURES SHOULD
BEGIN TO SLOWLY MODERATE ON WEDNESDAY...WE SHOULD SEE MORE DRAMATIC
WARMING ON THURSDAY AS THE FLOW TURNS OFFSHORE. WEAK TO MODERATE
OFFSHORE FLOW SHOULD CONTINUE FRIDAY INTO SATURDAY WITH A CONTINUED
WARMING TREND. HIGH TEMPERATURES SHOULD CLIMB WELL INTO THE 80S IN
THE VALLEYS ON FRIDAY AND SATURDAY.
&&
.AVIATION...24/2100Z
EDDY CIRCULATION FROM THIS MORNING HAS GIVEN WAY TO MOSTLY ONSHORE
FLOW. MOST AIRFIELDS S OF KSBA HAVE EXPERIENCED SOME CLEARING...BUT
SHOULD BE SHORT LIVED AS STRATUS SHOULD REFORM AROUND 03Z AND BEGIN
ITS MARCH INLAND SHORTLY THEREAFTER. KSBA AND NORTHWARD WILL
CONTINUE TO BE UNDER STRATUS THROUGH TONIGHT. CIGS WILL LOWER
OVERALL THROUGH THE NIGHT DOWN TO IFR/MVFR...AS MARINE SHOULD SHRINK
SOME...MUCH DIFFERENT FROM THE RAPID DEEPENING SEEN TODAY ASSOCIATED
WITH THE BROAD SOUTHERLY FLOW.
KLAX SHOULD SEE SOME SCT DECKS...BUT MAY GO ON AGAIN OFF AGAIN SCT
TO BKN 028 THROUGH ABOUT 04Z...THEN GO SOLID OVC SOON THEREAFTER.
CIGS SHOULD BE LOWER OVERALL TONIGHT...NEAR 018 BY 06Z....AND
POSSIBLY LOWERING DOWN TO NEAR 010 BY SUNRISE. WESTERLY WIND SHOULD
CONTINUE AT AROUND 10 KT...THEN GO WEAK. NO SIGNIFICANT SOUTHEAST
WINDS EXPECTED OVER 6 KT THROUGH SUN MORNING.
KBUR WILL SEE CLEARING THROUGH ABOUT 04Z...WITH A LIKELY STRATUS
SURGE SOON THEREAFTER. STRATUS WILL RETURN WITH LOWERED CIGS...AND A
GOOD SHOT OF GOING BELOW 010 AFTER 10Z. SOUTH WINDS WILL CONTINUE
UNTIL ABOUT 03Z...THEN STAY LIGHT THROUGH THE REST OF THE NIGHT.
&&
.MARINE...
A COLD FRONT WILL PASS THROUGH THE COASTAL WATERS LATE MONDAY. THIS
STORM WILL BRING INCREASED NW WIND...POSSIBLY REACHING GALE
CONDITIONS EARLY TUESDAY OVER THE OUTER AND INNER WATERS. THIS STORM
WILL ALSO GENERATE A RELATIVELY LARGE WESTERLY SWELL BY TUESDAY.
SEA HEIGHTS ARE EXPECTED TO REACH 14 FT OVER THE OUTER WATERS AND
PUSH CLOSE TO 10 FT OVER THE INNER WATERS. THE COMBINATION OF THIS
LARGE SWELL...GUSTY WINDS...AND POSSIBLE THUNDERSTORMS WILL CREATE
POTENTIALLY HAZARDOUS SEA CONDITIONS FROM LATE MONDAY THROUGH
WEDNESDAY. MARINERS SHOULD KEEP ABREAST OF THIS DEVELOPING SITUATION
FOR EARLY NEXT WEEK.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
&&
$$
PUBLIC...GOMBERG
AVIATION/MARINE...KITTELL
WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATE
NWS LOS ANGELES/OXNARD CA
1030 AM PDT SAT MAR 24 2007
UPDATED AVIATION DISCUSSION
.SHORT TERM (TODAY-MONDAY)...MARINE LAYER HAS DEEPENED RAPIDLY THIS
MORNING ACROSS THE LA BASIN...WITH PILOT REPORTS AND ACARS DATA
INDICATING A DEPTH AROUND 4000 FEET. AS A RESULT...LOW CLOUDS AND
FOG HAVE SURGED WELL INTO THE SANTA CLARITA VALLEY AND LOWER COASTAL
SLOPES DURING THE PAST FEW HOURS. THE BIG QUESTION MARK TODAY WILL
BE THE AMOUNT OF STRATUS BURNOFF. THERE MAY BE SOME DIFFICULTY IN
CLEARING ACROSS SOME AREAS TODAY...SO PARTLY CLOUDY OR PARTIAL
AFTERNOON CLEARING WORDING HAS BEEN MENTIONED IN CURRENT ZONE
PACKAGE. WITH THE DEEPENING MARINE LAYER...WILL SEE A SIGNIFICANT
DROP IN TEMPERATURES TODAY ACROSS MOST AREAS...WITH MOST COASTAL AND
VALLEY AREAS REMAINING IN THE 60S. THE ANTELOPE VALLEY WILL CONTINUE
TO SEE WARM TEMPERATURES WELL INTO THE 70S.
*** FROM PREVIOUS DISCUSSION ***
WEAK RIDGING WILL REMAIN IN PLACE THROUGH AT LEAST SUNDAY
AFTERNOON AS DEVELOPING TROUGH IN THE GULF OF ALASKA PUSHES DOWN
TO THE WEST COAST. MODELS STILL ARE STRUGGLING WITH MODELING THE
TROUGHS INTENSITY SOME. POPS AND WEATHER HAVE BEEN CHANGED VERY
LITTLE AS THIS SERIES OF MODEL RUNS HAS BACKED OFF THE TROUGHS
STRENGTH. THE TROUGH TILT...WHICH THE ALL MODELS INDICATED A FAIR
AMOUNT OF IN PREVIOUS RUNS...IS PRETTY MUCH NON-EXISTENT. IN
ADDITION TO THE TROUGH BEING VERTICALLY STACKED...LATEST 850 MB
TEMPERATURE PATTERN INDICATES LITTLE PRESENCE OF WARM AIR
ADVECTION OCCURRING AHEAD OF THE TROUGHS FRONTAL BOUNDARY. TIMING
APPEARS TO BE PRETTY CONSISTENT AMONGST ALL MODEL SOLUTIONS
THOUGH...WITH PRECIPITATION ARRIVING ALONG THE CENTRAL COAST
MONDAY AFTERNOON OR EVENING.
.LONG TERM (TUESDAY-FRIDAY)...PRECIPITATION THREAT SHOULD SHIFT
SOUTHWARD INTO THE SOUTHLAND LATE MONDAY NIGHT OR INTO TUESDAY
MORNING. COLD AIR ARRIVES RAPIDLY BEHIND THE FRONTAL
BOUNDARY...WITH 500 MB AND 700 MB TEMPERATURES DROPPING RAPIDLY.
CONVECTIVE SHOWERS AND THUNDERSTORMS SHOULD OCCUR BEHIND IN THE
COLD AIR SECTOR AS 500 MB TEMPERATURES DROP BELOW -25 CELSIUS ON
TUESDAY MORNING. TREND MAY ALSO INDICATE THAT PRECIPITATION WITH
THIS STORM SYSTEM MAY VERY LIKELY BE MORE SHOWERY THAN STRATIFORM.
CLEARING SHOULD COMMENCE ON TUESDAY AFTERNOON AND TUESDAY NIGHT
AS UPPER-LEVEL PATTERN SETS UP FOR A SERIES OF OFFSHORE FLOW
EVENTS FOR MIDWEEK. GFS INDICATES RATHER MODERATE EVENTS AT THE
CURRENT TIMES...WITH ADVISORY LEVEL WINDS LIKELY OCCURRING. AMPLE
THERMAL AND PRESSURE GRADIENTS DEVELOP TUESDAY AFTERNOON INTO
AT LEAST THURSDAY MORNING FOR OFFSHORE WINDS.
MUCH DIVERGENCE OCCURS AS FAR AS WHAT MAY HAPPEN FOR LATE NEXT
WEEK. GFS AND ECMWF CONTINUE TO INDICATE GENERAL RIDGE PATTERN
CONTINUING BUT SOME MODEL RUNS ARE CARVING A TROUGH THROUGH THE
RIDGE PATTERN. FORECAST KEEPS RIDING PATTERN IN PLACE FOR NOW.
&&
.AVIATION...24/1730Z
EDDY CIRCULATION FROM THIS MORNING HAS CREATED BROAD SOUTHERLY FLOW
WITH A RAPIDLY DEEPENING MARINE LAYER AT ALL COASTAL AND VALLEY
AIRFIELDS. FLOW IS STARTING TO TURN ONSHORE AS OF 17Z AND CLEARING
ACTUALLY LOOKS POSSIBLE AT MOST SITES. AFTER 20Z...ALL AIRFIELDS
SHOULD BE VFR...EXCEPT FOR KSBA AND KOXR POSSIBLY SEEING AN
OCCASIONAL MVFR CIG THROUGH 22Z OR SO. WINDS WILL BE RELATIVELY
LIGHT TODAY...EXCEPT FOR KWJF AND KPMD POSSIBLY SEEING SW WINDS NEAR
15 KT LATER THIS AFTERNOON.
KLAX WILL CONTINUE TO IMPROVE...WITH A VFR CIG ABOVE 030 CONTINUING
THROUGH 20Z. STRATUS ERODING TO THE SOUTHEAST OF THE AIRPORT...AND
THAT CLEARING SHOULD REACH KLAX BY 20Z. SHOULD START TO SEE A SHIFT
IN THE WIND FROM SOUTHEAST...TO SOUTHWEST AROUND 10 KT. STRATUS WILL
RETURN THIS EVENING AFTER 04Z...BUT MAY RETURN A LITTLE
EARLIER...WITH CIGS LOWER...NEAR 018 AT THE ONSET.
KBUR WILL CONTINUE TO SEE A CIG THROUGH 21Z...BUT MAY POP ABOVE 030
BETWEEN 18Z-20Z...WITH CLEARING LIKELY AFTER 21Z. SOUTH WINDS NEAR
08 KT WILL CONTINUE INTO THE EVENING. STRATUS WILL RETURN AROUND
05Z...WITH LOWERED CIGS...AND A GOOD SHOT OF GOING BELOW 010 AFTER
10Z.
&&
.MARINE...
A COLD FRONT WILL PASS THROUGH THE COASTAL WATERS LATE MONDAY. THIS
STORM WILL BRING INCREASED NW WIND...POSSIBLY REACHING GALE
CONDITIONS EARLY TUESDAY OVER THE OUTER AND INNER WATERS. THIS STORM
WILL ALSO GENERATE A RELATIVELY LARGE WESTERLY SWELL BY TUESDAY.
SEA HEIGHTS ARE EXPECTED TO REACH 14 FT OVER THE OUTER WATERS AND
PUSH CLOSE TO 10 FT OVER THE INNER WATERS. THE COMBINATION OF THIS
LARGE SWELL...GUSTY WINDS...AND POSSIBLE THUNDERSTORMS WILL CREATE
POTENTIALLY HAZARDOUS SEA CONDITIONS FROM LATE MONDAY THROUGH
WEDNESDAY. MARINERS SHOULD KEEP ABREAST OF THIS DEVELOPING SITUATION
FOR EARLY NEXT WEEK.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PACIFIC COASTAL WATERS...
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS (SEE LAXCWFLOX).
&&
$$
PUBLIC...GOMBERG/HALL
AVIATION/MARINE...KITTELL
WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
830 AM PDT SAT MAR 24 2007
.SHORT TERM (TODAY-MONDAY)...MARINE LAYER HAS DEEPENED RAPIDLY THIS
MORNING ACROSS THE LA BASIN...WITH PILOT REPORTS AND ACARS DATA INDICATING
A DEPTH AROUND 4000 FEET. AS A RESULT...LOW CLOUDS AND FOG HAVE SURGED
WELL INTO THE SANTA CLARITA VALLEY AND LOWER COASTAL SLOPES DURING THE
PAST FEW HOURS. THE BIG QUESTION MARK TODAY WILL BE THE AMOUNT OF STRATUS
BURNOFF. THERE MAY BE SOME DIFFICULTY IN CLEARING ACROSS SOME AREAS TODAY...SO
PARTLY CLOUDY OR PARTIAL AFTERNOON CLEARING WORDING HAS BEEN MENTIONED IN
CURRENT ZONE PACKAGE. WITH THE DEEPENING MARINE LAYER...WILL SEE A SIGNIFICANT
DROP IN TEMPERATURES TODAY ACROSS MOST AREAS...WITH MOST COASTAL AND VALLEY
AREAS REMAINING IN THE 60S. THE ANTELOPE VALLEY WILL CONTINUE TO SEE WARM
TEMPERATURES WELL INTO THE 70S.
*** FROM PREVIOUS DISCUSSION ***
WEAK RIDGING WILL REMAIN IN PLACE THROUGH AT LEAST SUNDAY
AFTERNOON AS DEVELOPING TROUGH IN THE GULF OF ALASKA PUSHES DOWN
TO THE WEST COAST. MODELS STILL ARE STRUGGLING WITH MODELING THE
TROUGHS INTENSITY SOME. POPS AND WEATHER HAVE BEEN CHANGED VERY
LITTLE AS THIS SERIES OF MODEL RUNS HAS BACKED OFF THE TROUGHS
STRENGTH. THE TROUGH TILT...WHICH THE ALL MODELS INDICATED A FAIR
AMOUNT OF IN PREVIOUS RUNS...IS PRETTY MUCH NON-EXISTENT. IN
ADDITION TO THE TROUGH BEING VERTICALLY STACKED...LATEST 850 MB
TEMPERATURE PATTERN INDICATES LITTLE PRESENCE OF WARM AIR
ADVECTION OCCURRING AHEAD OF THE TROUGHS FRONTAL BOUNDARY. TIMING
APPEARS TO BE PRETTY CONSISTENT AMONGST ALL MODEL SOLUTIONS
THOUGH...WITH PRECIPITATION ARRIVING ALONG THE CENTRAL COAST
MONDAY AFTERNOON OR EVENING.
.LONG TERM (TUESDAY-FRIDAY)...PRECIPITATION THREAT SHOULD SHIFT
SOUTHWARD INTO THE SOUTHLAND LATE MONDAY NIGHT OR INTO TUESDAY
MORNING. COLD AIR ARRIVES RAPIDLY BEHIND THE FRONTAL
BOUNDARY...WITH 500 MB AND 700 MB TEMPERATURES DROPPING RAPIDLY.
CONVECTIVE SHOWERS AND THUNDERSTORMS SHOULD OCCUR BEHIND IN THE
COLD AIR SECTOR AS 500 MB TEMPERATURES DROP BELOW -25 CELSIUS ON
TUESDAY MORNING. TREND MAY ALSO INDICATE THAT PRECIPITATION WITH
THIS STORM SYSTEM MAY VERY LIKELY BE MORE SHOWERY THAN STRATIFORM.
CLEARING SHOULD COMMENCE ON TUESDAY AFTERNOON AND TUESDAY NIGHT
AS UPPER-LEVEL PATTERN SETS UP FOR A SERIES OF OFFSHORE FLOW
EVENTS FOR MIDWEEK. GFS INDICATES RATHER MODERATE EVENTS AT THE
CURRENT TIMES...WITH ADVISORY LEVEL WINDS LIKELY OCCURRING. AMPLE
THERMAL AND PRESSURE GRADIENTS DEVELOP TUESDAY AFTERNOON INTO
AT LEAST THURSDAY MORNING FOR OFFSHORE WINDS.
MUCH DIVERGENCE OCCURS AS FAR AS WHAT MAY HAPPEN FOR LATE NEXT
WEEK. GFS AND ECMWF CONTINUE TO INDICATE GENERAL RIDGE PATTERN
CONTINUING BUT SOME MODEL RUNS ARE CARVING A TROUGH THROUGH THE
RIDGE PATTERN. FORECAST KEEPS RIDING PATTERN IN PLACE FOR NOW.
&&
.AVIATION...24/0900Z...ONSHORE FLOW WILL PERSIST TODAY AS LOW
CLOUDS WITH MVFR CIGS TO THE SOUTH AND IFR CIGS N OF POINT
CONCEPTION WILL CONTINUE THROUGH THE MID MORNING HOURS IN THE
VALLEYS TO THE EARLY AFTERNOON HOURS ACROSS THE COASTAL PLAIN WITH
ONLY PARTIAL CLEARING NEAR THE IMMEDIATE COAST TODAY. VSBYS THIS
MORNING GENERALLY VFR/MVFR IN MOST AREAS. LOOKS LIKE KPRB WILL NOW
STAY CLEAR THIS MORNING AS DEWPOINT DEPRESSION IS FAR ENOUGH APART
NOT TO WARRANT ANY STRATUS AND DENSE FOG ISSUES. EXPECT GUSTY
SOUTHWEST TO WEST WINDS ACROSS THE ANTELOPE VALLEY TODAY.
KLAX WILL EXPERIENCE MVFR CIGS THROUGH EARLY AFTERNOON HOURS...WITH
STUBBORN CLEARING ALONG THE IMMEDIATE COAST. EXPECT SE WINDS BELOW 6
KT THROUGH 12Z...BECOMING VARIABLE 6 KT OR LESS. SOUTHWEST SEABREEZE
SHOULD PICK UP NEAR 18Z AND BECOME WESTERLY THIS AFTERNOON. WINDS
SHOULD BE SUSTAINED NEAR 12 KT THIS AFTERNOON THROUGH EARLY EVENING
HOURS.
KBUR WILL HAVE MVFR CIGS THIS MORNING. CIGS SHOULD BURN OFF BY
17-18Z THIS MORNING. NOT EXPECTING LIFR/IFR VSBYS WITH DEEPER MARINE
LAYER IN PLACE. NOT EXPECTING ANY UNTYPICAL WIND ISSUES TODAY.
&&
.MARINE...A RELATIVELY LARGE WESTERLY SWELL WILL IMPACT THE
CENTRAL COAST BY TUESDAY WITH SWELLS FORECAST TO REACH 14 FEET
ACROSS THE OUTER WATERS. THE SANTA BARBARA CHANNEL INNER WATERS
WILL ALSO SEE POTENTIAL SWELLS UP TO 10 FEET TUESDAY NIGHT THROUGH
EARLY WEDNESDAY MORNING. THE COMBINATION OF THIS LARGE
SWELL...GUSTY WINDS AND POSSIBLE THUNDER SHOULD MAKE FOR
POTENTIALLY ROUGH SEAS FROM LATE MONDAY NIGHT THROUGH EARLY
WEDNESDAY. MARINERS SHOULD KEEP ABREAST OF THIS DEVELOPING
SITUATION FOR EARLY NEXT WEEK.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PACIFIC COASTAL WATERS...
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS (SEE LAXCWFLOX).
&&
$$
PUBLIC...GOMBERG/HALL
AVIATION/MARINE...KAPLAN
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
400 AM PDT SAT MAR 24 2007
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER SOUTHERN CALIFORNIA THIS WEEKEND
BRINGING FAIR AND DRY WEATHER WITH WARMER TEMPERATURES FOR INLAND
AREAS. THE MARINE LAYER WILL KEEP COASTAL AREAS COOLER WITH NIGHT
AND MORNING LOW CLOUDS AND FOG. A FAST MOVING PACIFIC STORM SYSTEM
WILL MOVE THROUGH CALIFORNIA TUESDAY BRINGING COOLING...STRONG GUSTY
WINDS IN THE MOUNTAINS AND DESERTS...AND A CHANCE OF SHOWERS. FAIR
WITH A WARMING TREND FOR THE LATTER HALF OF NEXT WEEK AS BROAD HIGH
PRESSURE BUILDS INTO CALIFORNIA.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.SHORT TERM (TODAY THROUGH MONDAY)...
HIGH PRESSURE WILL BUILD OVER SOUTHERN CALIFORNIA THROUGH SUNDAY...
THEN BEGIN TO WEAKEN MONDAY. THIS WILL BRING FAIR AND DRY WEATHER
WITH WARMER TEMPERATURES FOR INLAND AREAS THROUGH SUNDAY...THEN SLOW
COOLING MONDAY. WEST OF THE MOUNTAINS...THE MARINE LAYER WILL KEEP
TEMPERATURES NEAR SEASONAL LEVELS WITH NIGHT AND MORNING LOW CLOUDS
AND FOG. CURRENT ACARS SOUNDINGS SHOW A WEAKENING MARINE INVERSION
NEAR 5000 FEET WITH A SECOND INVERSION DEVELOPING AND STRENGTHENING
BETWEEN 2500 AND 3000 FEET. THIS LOWER INVERSION SHOULD BECOME THE
DOMINANT INVERSION THE NEXT COUPLE OF DAYS...LOWERING AND
STRENGTHENING SOME THROUGH SUNDAY AS HIGH PRESSURE STRENGTHENS
ALOFT. THE MARINE LAYER SHOULD BEGIN TO DEEPEN SOME MONDAY AS HIGH
PRESSURE BEGINS TO WEAKEN.
&&
.LONG TERM (TUESDAY THROUGH FRIDAY)...
FOR TUESDAY...STILL DECENT AGREEMENT AMONG THE MODELS ON A FAST
MOVING PACIFIC STORM SYSTEM THAT WILL MOVE THROUGH CALIFORNIA. FOR
SOUTHWEST CALIFORNIA...THIS WILL BRING COOLING...STRONG GUSTY WINDS
IN THE MOUNTAINS AND DESERTS...A MUCH DEEPER MARINE LAYER MONDAY
NIGHT AND TUESDAY...AND A CHANCE OF SHOWERS LATE MONDAY NIGHT
THROUGH TUESDAY. FOR THE LATTER HALF OF NEXT WEEK...BROAD HIGH
PRESSURE BUILDS OVER CALIFORNIA. THIS WILL BRING FAIR AND DRY
WEATHER WITH A STEADY WARMING TREND INTO THE WEEKEND.
&&
.AVIATION...
241040Z...MARINE LAYER WITH A DEEP MOIST LAYER WITH GENERALLY TWO
DECKS...ONE WITH BASES ABOUT 2000 FT MSL NEAR THE COAST AND THE
OTHER HAS BASES ABOUT 5000 FT MSL INLAND. ALSO SOME STRATUS FILLING
IN THE COACHELLA VALLEY WITH BASES ABOUT 5500 FEET MSL. TOPS ABOUT
2500 FT NEAR THE COAST AND LOCAL TOPS UP TO 6000 FT INLAND AND IN
THE LOWER DESERTS. VIS VFR WITH LOCAL MVFR AND ISOLD IFR POSSIBLE
NEAR THE FOOTHILLS. EXPECT STRATUS TO CLEAR TO THE COAST BY 17Z AND
BE MOSTLY OUT OF THE COAST BY 19Z. STRATUS SHOULD SPREAD BACK IN
ALONG THE COAST BY 02Z THIS EVENING AND INLAND BEFORE MIDNIGHT.
WINDS AT 5K FT...NORTHWEST 10KT EARLY THIS MORNING...BECOMING LIGHT
AND VARIABLE LATE THIS MORNING THROUGH SUN MORNING...THEN WEST 5-10
KT SUN AFTERNOON. WINDS AT 10K FT...NORTHWEST TO NORTH 10-15 KT...
NORTHEAST 10-15 KT TONIGHT...BECOMING NORTHWEST TO NORTH 10 KT LATE
SUN MORNING THROUGH AFTERNOON.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...MARTIN
AVIATION/MARINE...WHITLOW
NWS ON THE WEB AT WEATHER.GOV/SANDIEGO
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
257 AM EDT SAT MAR 24 2007
.SHORT TERM (TODAY AND TONIGHT)...
OVER THE PAST FEW DAYS...SHORT-RANGE MODELS HAVE BEEN PROGRESSIVELY
DIMINISHING OUR PRECIP CHANCES FOR TODAY. RUC13 INITIALIZED WELL
WITH RAINFALL AND SFC TEMPS...SO FOLLOWED CLOSE TO THIS FOR POPS
AND HIGH TEMPS.
CURRENTLY...SFC WARM FRONTAL BOUNDARY IS LOCATED TO OUR NORTH FROM
ROUGHLY COLUMBUS OH TO DES MOINES IA. STRONG 500MB RIDGE IS LOCATED
ACROSS THE GULF...WITH SFC HIGH PRESSURE DOMINATING THE SERN CONUS.
WEAKENING SHORTWAVE MOVING ALONG THE OHIO RIVER IS STILL GENERATING
SHOWERS ACROSS OUR INDIANA COUNTIES AS IT MOVES NE AROUND THE RIDGE.
THESE SHOWERS WILL CONTINUE TO MOVE NE OUT OF THE CWA...BUT WILL
LIKELY CONTINUE ACROSS OUR FAR NERN CWA UNTIL ABOUT SUNRISE. THINK
I WILL LEAVE OUT POPS FROM THE GRIDS AND WILL HANDLE RESIDUAL
SHOWERS WITH NOWCASTS.
SHORT-RANGE MODELS MOVE THE 585DM LINE NORTHWARD ACROSS THE CWA
TODAY...WHICH SHOULD SUPPRESS ANY CONVECTION. THUS WILL REMOVE POPS
FROM THE GRIDS TODAY THROUGH THE AFTERNOON HOURS. AND BECAUSE OF
THIS...WILL INCREASE TEMPS A TAD...TOWARD RUC13 VALUES OF LOW 80S
SOUTH TO UPPER 70S NORTH (SIMILAR TO A BLEND OF RAW GFS AND MET
GUIDANCE VALUES).
THE FRONT TO OUR NORTH IS PROGGED TO SAG A BIT SOUTHWARD
TONIGHT...AND ORIENT ITSELF FROM NW TO SE...VERY CLOSE TO OUR NERN
CWA BORDER. MOS POPS AT LEX RANGE FROM 20-50 PERCENT. REALLY THINK
ANY ACTIVITY WOULD BE TO OUR NE...BUT WITH THE BOUNDARY SO CLOSE
WILL INSERT A SLT CHC POP ACROSS THE FAR NERN CWA...MAINLY NE OF A
SALEM IN TO WINCHESTER KY LINE AFTER 21Z. WILL END SHORTLY AFTER
MIDNIGHT WITH THE LOSS OF HEATING.
WENT SLIGHTLY BELOW RUC TEMPS FOR OVERNIGHT LOWS...WITH UPPER 50S
NNE...TO MID-TO-LOW 50S DOWN SOUTH WHERE CLOUDS WILL BE LESS.
AL
.LONG TERM (SUNDAY THROUGH FRIDAY)...
SUNDAY THROUGH MONDAY NIGHT...
ANOMALOUS RIDGING MORE TYPICAL OF LATE MAY WILL BE CENTERED ACROSS
THE LOWER OHIO VALLEY SUNDAY AND MONDAY. 500MB HEIGHTS WILL AVERAGE
OVER 5820M ACROSS OUR CWA...WHICH IS AROUND 2.5 STANDARD DEVIATIONS
ABOVE NORMAL FOR LATE MARCH. AFTERNOON TEMPERATURES...WHILE NOT
SETTING RECORD HIGHS...WILL APPROACH THEM. IF AMPLE SUN IS AVAILABLE
SUNDAY AND MONDAY...HIGHS IN THE LOWER 80S ARE LIKELY.
THIS RIDGING WILL CORRESPOND TO TROUGHING OUT WEST. ON SUNDAY...ONE
UPPER DISTURBANCE WILL BE EJECTING NORTHEASTWARD OUT OF THE MEAN TROUGH
CENTERED OVER THE ROCKIES AND WILL MOVE ACROSS THE UPPER MIDWEST.
THE MAIN WESTERN TROUGH WILL HANG BACK OVER THE DESERT
SOUTHWEST...AND WILL HAVE TO WAIT UNTIL EARLY TUESDAY TO MOVE EAST
INTO THE SOUTHERN PLAINS.
THE GFS 925MB FORECAST TEMPERATURES 17C SUNDAY AFTERNOON
18C MONDAY AFTERNOON
15C TUESDAY AFTERNOON
GIVEN GOOD INSOLATION...MONDAY MAY HAVE THE WARMEST TEMPERATURES OF
ALL. WITH RIDGING EXTENDING FROM THE GULF STATES ALL THE WAY TO THE
GREAT LAKES...FEEL THAT BOTH SUNDAY AND MONDAY WILL BE DRY. FORECAST
SOUNDINGS SHOW NO INSTABILITY SUNDAY WITH SOMEWHAT MORE UNSTABLE
CONDITIONS MONDAY. HOWEVER...WITH NO NOTICEABLE TRIGGER
MONDAY...WILL REMOVE POPS.
TUESDAY THROUGH WEDNESDAY...
A POWERFUL AND DEEP TROUGH MOVING ONTO THE WEST COAST LATE MONDAY
WILL SERVE TO KICK OUT THE AFOREMENTIONED UPPER LOW ACROSS THE
SOUTHERN ROCKIES INTO THE PLAINS ON TUESDAY. THIS OPEN TROUGH SHOULD
WEAKEN AS IT IMPINGES UPON THE STRONG RIDGE ACROSS THE SOUTHEASTERN
STATES...AND IS FORECAST TO CROSS OKLAHOMA BY BOTH THE NAM AND THE
GFS TUESDAY. DEEP SOUTHERLY FLOW AND PRECIPITABLE WATER WILL
INCREASE TUESDAY AND WEDNESDAY ACROSS THE LOWER OHIO VALLEY AHEAD OF
THIS TROUGH AND WILL CONTINUE CHANCE WORDING FOR POPS TUESDAY AND
ADD CHANCE POPS WEDNESDAY.
EXPECT WELL ABOVE NORMAL TEMPERATURES TO CONTINUE THROUGH AT LEAST
THURSDAY...ALTHOUGH SLIGHTLY REDUCED TUESDAY AND WEDNESDAY DUE TO
ADDITIONAL CLOUD COVER.
THURSDAY AND FRIDAY...
TROUGHING WILL BECOME WELL ESTABLISHED ACROSS THE ROCKIES AS STRONG
LOW PRESSURE MOVES NORTH ACROSS THE CENTRAL PLAINS THURSDAY. A COLD
FRONT IS EXPECTED TO MOVE EAST ACROSS THE SOUTHERN PLAINS THURSDAY
AND PERHAPS ACROSS THE MISSISSIPPI RIVER FRIDAY. WITH OUR FORECAST
AREA STILL UNDER RIDGING...WARM TEMPERATURES AND A CHANCE OF
AFTERNOON CONVECTION WILL CONTINUE THROUGH FRIDAY.
JSD
.AVIATION (06Z TAFS)...
WITH UPPER RIDGE MOVING FURTHER NORTH...THINK THAT PRECIP CHANCES
WILL BE SLIM ACROSS THE AREA THROUGH THE TAF PERIOD...AND ALL SITES
SHOULD REMAIN VFR. SCATTERED MID-LEVEL CLOUDINESS IS POSSIBLE AT LEX
AND SDF FROM CURRENT HOUR THROUGH MOST OF THE TAF PERIOD. JUST A FEW
HIGH CLOUDS EXPECTED IN BWG`S VICINITY.
IN THE 18-24 HOUR TIME FRAME...THE WARM FRONT THAT IS CURRENTLY TO
OUR NORTH IS PROGGED TO SAG SOUTHWARD AND ORIENT ITSELF IN A NW TO
SE FASHION THIS EVENING...COMING CLOSE TO THE LEX TAF SITE. STEEP
LOW-LEVEL LAPSE RATES MAY BE INDICATIVE OF AN ISLD SHRA WITH THIS
BOUNDARY...HOWEVER WILL NOT INCLUDE IN TAF AT THIS TIME. MAY BEEF UP
CLOUD COVER AT LEX AFTER 21Z. EXPECTING TO BE CAPPED JUST ENOUGH
THAT PRECIP WOULD STAY NE OF THE SDF AND LEX TAF SITES.
WILL REMOVE LOW-LEVEL WIND SHEAR FROM TAFS BASED ON VWPS FROM
REGIONAL RADARS AND MOST RECENT SDF ACARS SOUNDING. THE CURRENT AND
FORECAST 1-2KFT WINDS ARE ONLY ABOUT 20-25 KTS...AND WITH SFC WINDS
AT LEAST 5 KTS...LLWS CRITERIA IS NOT MET AND SHOULD NOT BE MET
THROUGH THE TAF PERIOD. MAY BE A BIT GUSTY FROM 15-22Z AT SDF AND
LEX...PERHAPS UP TO 15 KTS OR SO...BUT NOTHING OUT OF HAND.
AL
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
117 AM EDT SAT MAR 24 2007
.AVIATION (06Z TAFS)...
WITH UPPER RIDGE MOVING FURTHER NORTH...THINK THAT PRECIP CHANCES
WILL BE SLIM ACROSS THE AREA THROUGH THE TAF PERIOD...AND ALL SITES
SHOULD REMAIN VFR. SCATTERED MID-LEVEL CLOUDINESS IS POSSIBLE AT LEX
AND SDF FROM CURRENT HOUR THROUGH MOST OF THE TAF PERIOD. JUST A FEW
HIGH CLOUDS EXPECTED IN BWG`S VICINITY.
IN THE 18-24 HOUR TIME FRAME...THE WARM FRONT THAT IS CURRENTLY TO
OUR NORTH IS PROGGED TO SAG SOUTHWARD AND ORIENT ITSELF IN A NW TO
SE FASHION THIS EVENING...COMING CLOSE TO THE LEX TAF SITE. STEEP
LOW-LEVEL LAPSE RATES MAY BE INDICATIVE OF AN ISLD SHRA WITH THIS
BOUNDARY...HOWEVER WILL NOT INCLUDE IN TAF AT THIS TIME. MAY BEEF UP
CLOUD COVER AT LEX AFTER 21Z. EXPECTING TO BE CAPPED JUST ENOUGH
THAT PRECIP WOULD STAY NE OF THE SDF AND LEX TAF SITES.
WILL REMOVE LOW-LEVEL WIND SHEAR FROM TAFS BASED ON VWPS FROM
REGIONAL RADARS AND MOST RECENT SDF ACARS SOUNDING. THE CURRENT AND
FORECAST 1-2KFT WINDS ARE ONLY ABOUT 20-25 KTS...AND WITH SFC WINDS
AT LEAST 5 KTS...LLWS CRITERIA IS NOT MET AND SHOULD NOT BE MET
THROUGH THE TAF PERIOD. MAY BE A BIT GUSTY FROM 15-22Z AT SDF AND
LEX...PERHAPS UP TO 15 KTS OR SO...BUT NOTHING OUT OF HAND.
AL
&&
.PREV DISCUSSION...
EVENING UPDATE...
WEAKENING IMPULSE MOVING FROM MO INTO SOUTH CENTRAL IL AND SOUTHERN
IN ALONG THE PERIPHERY OF THE STRONG 587 H500 RIDGE CENTERED NEAR
THE DESTIN FLA COASTLINE. SCATTERED SHOWER ACTIVITY SHOULD REACH
THE SOUTHERN INDIANA AND NORTH CENTRAL COUNTIES WEST OF INTERSTATE
65 BEFORE LOSING COVERAGE AS IT MOVES TOWARDS INTERSTATE 75 AND
THE LEXINGTON METRO AREA. THEREFORE WILL RAISE POPS IN THE
NORTHWESTERN THIRD OF THE FORECAST AREA FROM SCOTTSBURG INDIANA
SOUTHWEST TO HAWESVILLE KENTUCKY. WILL MAKE TWEAKS TO CLOUDS TO
CATCH CURRENT TRENDS...WILL ADJUST LOWER ACROSS THE SOUTH WHERE
FEW TO SCT MID LVL CLOUDS ARE BEING FOUND...SMALL UPWARD TWEAK
OF ABOUT 2 DEGREES LOOKS NEEDED FOR OVERNIGHT LOWS WITH DEWPOINTS
IN THE MID AND UPPER 50S AND SOME CLOUDS IT WILL BE HARD FOR MUCH
OF THE AREA TO DROP MUCH BELOW 60...MORE THAN 20 DEGREES ABOVE THE
NORMAL LOW AND NEAR OR JUST ABOVE THE NORMAL HIGHS FOR THE DAY!.
SCHOTT
SHORT TERM (TNGT AND SAT)...
MAY-LIKE TEMPS IN MAR WITH FRONT FROM IND TO SRN OH ATTM TO STAY
WELL TO OUR NORTH.
WEAKENING AREA OF SHOWERS TO AFFECT MAINLY THE NRN HALF OF OUR FA
LATE THIS AFTN...THESE AHD OF UPR IMPLSE RIDING EWD ON SRN EDGE OF
WESTERLIES. WOULD ONLY EXPECT ABOUT .10 OF AN INCH OVER OUR SRN
INDIANA COUNTIES BY 00Z THIS EVE WITH LIGHTER AMOUNTS SOUTHWARD TO
NEAR THE OHIO RIVER ACRS NCNTRL KY AND THE NRN BLUEGRASS REGION.
A SECOND IMPLSE COMING NEWD IN DIFFLUENT FLO...ATTM ACRS ERN OK...
IS SPAWNING A NEW MCS ACRS SERN KS/MO. THIS IMPLSE FCST TO TAKE A
SIMILAR PATH AS THE AFOREMENTIONED ONE...WHILE WEAKENING. WILL
THEREFORE KEEP CHC POPS IN THE FCST TNGT...HIEST N-LOWEST S WITH NO
POPS ACRS SCNTRL KY.
ONE LAST IMPLSE TOPS THE RIDGE SAT AS IT MOVES FROM NEAR STL TO NEAR
LOU BY SUN EVE. GFS FCST A BIT MORE UNSTABLE AMS(LIFTED INDICES NEAR
-2)AHD OF THIS FEATURE...WILL LEAVE THUNDER IN THE FCST AND SIMILAR
CHC POPS TO GOING FCST...AGAIN HIEST ACRS OUR NRN MOST FA.
WITH BUILDING RIDGE...AND ONLY MID/HIGH CLDS ACRS OUR SRN FA
SAT...CANT ARGUE AGAINST MAX TEMPS ARND 80...WITH TEMPS TEMPERED A
BIT NRN FA BY LOWER CLDS AND SCT SHOWERS/STMS.
DK
LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)...
SATURDAY NIGHT THROUGH MONDAY NIGHT...
HIGHLY AMPLIFIED UPPER AIR PATTERN IS FORECAST ACROSS NORTH AMERICA
DURING THIS TIME PERIOD. LARGE UPPER LOW OVER THE SOUTHWEST UNITED
STATES IS FORECAST TO LIFT NORTHEASTWARD INTO THE UPPER PLAINS AS
LARGE H5 RIDGE HOLDS SWAY ACROSS THE EASTERN THIRD OF THE US. BY
LATE IN THIS TIME PERIOD...00Z GFS ENSEMBLE MEANS SHOW DEEPENING H5
TROF COMING INTO THE WESTERN CONUS WHICH WILL HELP KICK OR FLATTEN
THE EAST COAST RIDGE SOMEWHAT. AT THE SFC...SFC WARM FRONTAL
BOUNDARY WILL BE TO OUR NORTH AND REMAIN THERE THROUGH THIS PORTION
OF THE FCST PERIOD. SEVERAL WEAK VORTS WILL LIKELY CRUISE THROUGH
WITHIN THE MEAN FLOW AND AROUND THE H5 RIDGE. THE GFS SOLUTIONS
KEEP MUCH OF THE PRECIP NORTH OF HERE...WHILE THE NAM-WRF SOLUTIONS
AREA BIT FURTHER SOUTH. WITH NO REAL FORCING MECHANISM...DO NOT SEE
MUCH OF A CHANCE OF MEASURABLE PRECIPITATION THROUGH MONDAY MORNING.
BY MONDAY...WITH FLATTENING RIDGE AND A SFC HIGH TO OUR EAST...GOOD
FLOW OF WARM MOIST AIR WILL PUSH IN AND DIURNAL CONVECTION SHOULD
GET GOING BY THE AFTERNOON. FOR NOW WILL KEEP LOW CHANCE POPS IN THE
FCST.
TEMPERATURES THROUGH THE PERIOD WILL BE WAY ABOVE NORMAL...FEELING
LIKE LATE MAY OR EARLY JUNE. STUCK CLOSE TO THE ENSEMBLE MEANS FOR
TEMPERATURES WITH OVERNIGHT LOWS IN THE MID AND UPPER 50S. HIGHS IN
THE UPPER 70S TO AROUND 80 IN THE NORTH FOR SUNDAY LOOK LIKE A GOOD
BET...WITH LOWER 80S ACROSS THE CENTRAL AND SOUTHERN TIERS. WITH
MORE CLOUDS AND POSSIBLE CONVECTION IN THE AREA
MONDAY...TEMPERATURES SHOULD BE A LITTLE COOLER...BUT WILL STILL BE
SOME 10-15 DEGREES ABOVE AVERAGE WITH HIGHS IN THE UPPER 70S.
TUESDAY THROUGH FRIDAY...
MAIN FORECAST CHALLENGE HERE WILL BE POP CHANCES. GIVEN THAT THE
PATTERN LOOKS LIKE ONE OF LATE MAY TO EARLY JUNE...DIURNALLY DRIVEN
CONVECTION APPEARS TO BE THE MAIN WEATHER MAKER THROUGH THURSDAY.
FOR NOW WILL KEEP LOW CHC POPS IN THE AFTERNOON AND EARLY EVENING
HOURS. BY THURSDAY...UPPER AIR PATTERN IS FORECAST TO BECOME MORE
ZONAL WITH TIME AS STRONG MID-LAT CYCLONE DEVELOPS AND HEADS NE INTO
THE SOUTHERN CANADA. ASSOCIATED SFC COLD FRONT IS PROGGED TO PUSH
INTO THE REGION LATE THU AND DURING THE DAY ON FRIDAY WHICH WILL
BRING A PERIOD OF WIDESPREAD RAIN AND STORMS TO THE AREA. WHILE MAIN
FORCING WILL BE NORTH OF THE REGION...OVERALL PATTERN LOOKS
INTERESTING FOR A ROUND OF CONVECTIVE WEATHER. SOMETHING TO WATCH
OVER THE NEXT FEW DAYS.
WARM WEATHER IS EXPECTED TO CONTINUE THROUGH THE PERIOD. STRONG
SOUTHERLY FLOW WILL KEEP TEMPERATURES RATHER WARM THROUGH THE PERIOD
WITH HIGHS IN THE MID TO UPPER 70S AND OVERNIGHT LOWS IN THE LOW TO
MID 50S. THIS IS FAIRLY CLOSE TO THE LATEST ENSEMBLE MEANS AND THE
ONGOING FORECAST...SO ONLY SOME MINOR ADJUSTMENTS WILL WERE NEEDED.
-MJ
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1030 PM EDT SUN MAR 25 2007
.UPDATE...SURFACE LOW AND COLD FRONT HAVE REACHED WRN WISCONSIN LATE
THIS EVENING...WITH A SHARP 500 MB TROUGH DIRECTLY OVER THE SURFACE
FEATURE. LINE OF CONVECTION AND INDIVIDUAL SUPERCELLS THAT DEVELOPED
AHEAD OF THE LINE HAVE SHOW A GENERAL DIMINISHING TREND LATE THIS
EVENING WITH LOSS OF DIURNAL HEATING/SB INSTABILITY. STILL...LESS
INTENSE CONVECTION DOES PERSIST ACROSS WISCONSIN AND WRN UPPER
MICHIGAN ATTM. A FEW SHOWERS HAVE TRIED (WITH LITTLE SUCCESS) TO
FIRE ALONG THE LAKE MICHIGAN SHORELINE FROM MANISTEE TO THE LEELANAU
PENINSULA DURING THE EVENING...BUT THE ENTIRE CWA REMAINS DRY AT
THIS HOUR. ADDITIONAL SHOWERS HAVE DEVELOPED OVER SRN LOWER MICHIGAN
WITHIN AN AREA OF ENHANCED LOW LEVEL MOISTURE (850 MB THETA E
RIDGING) AND ELEVATED INSTABILITY.
LATEST NAM SUGGESTS CONVECTION OVER WISCONSIN WILL REACH ERN UPR
MICHIGAN LATE TONIGHT...WITH THE SRN END OF THE CONVECTION FINALLY
REACHING NW LOWER MICHIGAN TOWARD DAYBREAK. WEAKER CONVECTION TO THE
SOUTH WILL REACH AREAS MAINLY SE OF A LINE FROM HTL TO APN OVERNIGHT
AND THEN PUSH EAST OF OUR CWA BY DAWN BEFORE CONVECTION IN PROXIMITY
TO THE LOW MOVES INTO THE REST OF NRN LOWER MICHIGAN DURING MONDAY
MORNING. WILL NEED TO DIMINISH POPS TO LIKELY OVERNIGHT...BUT WILL
KEEP THUNDER IN THE FORECAST AS SOME ELEVATED INSTABILITY WILL
REMAIN IN TACT AS THE 500 MB COLD POOL MOVES OVERHEAD. RISK OF
SEVERE TSRA IS LOW...BUT WOULD NOT RULE OUT THE POSSIBILITY OF SMALL
HAIL.
&&
.AVIATION...ISSUED 725 PM EDT SUN MAR 25 2007
VFR CIGS AND VSBYS WILL PERSIST THRU MOST OF THE EVENING ACROSS NRN
LOWER MICHIGAN. A PERIOD OF LOW LEVEL WIND SHEAR IS EXPECTED AT
PLN/TVC/APN AFTER SUNSET AS SFC WINDS DIMINISH BUT WINDS ABOVE THE
SURFACE INCREASE TO 35 TO 40 KNOTS IN ADVANCE OF A VIGOROUS LOW
PRESSURE SYSTEM AND COLD FRONT MOVING INTO THE WRN GREAT LAKES
REGION. THIS SYSTEM IS ALSO EXPECTED TO BRING A ROUND OF WIDESPREAD
SHOWERS AND THUNDERSTORMS TO THE PLN/TVC/APN AREAS LATE THIS EVENING
AND OVERNIGHT...WITH THE BEST COVERAGE OF PRECIP ANTICIPATED BETWEEN
05Z AND 09Z. LIGHTER SHOWERS/MVFR AND POSSIBLE IFR CEILINGS/VSBYS
THEN LINGER BEHIND THE FRONT THROUGH MONDAY MID TO LATE MORNING. A
FEW SHOWERS WILL LINGER AROUND APN INTO THE AFTERNOON. PARTIAL
CLEARING WILL TAKE PLACE AT PLN AND TVC IN THE AFTERNOON...WITH A
RETURN TO DRY WEATHER AND VFR CONDITIONS.
&&
.DISCUSSION...ISSUED 355 PM EDT SUN MAR 25 2007
MAIN CONCERN THIS GO AROUND FOCUSED ON CONVECTIVE POTENTIAL. EARLY
AFTERNOON ANALYSIS SHOWS POTENT UPPER SYSTEM CROSSING INTO WESTERN
MINNESOTA...WITH SURFACE REFLECTION ACROSS NORTHEAST SOUTH
DAKOTA...AND ATTENDANT WARM FRONT DRAPED INTO FAR SOUTHERN MICHIGAN.
INITIAL BAND OF PRECIPITATION...ASSOCIATED WITH STRONG SURGE OF WARM
ADVECTION...PUSHING THROUGH THE NORTHERN CWA AT THIS TIME...AND
EXPECT THIS WILL BE OUT OF THE PICTURE NEAR THE START OF THE NEW
FORECAST PERIOD. PRONOUNCED CLEAR SLOT HAS DEVELOPED OVER THE
SOUTHWESTERN CWA...ALLOWING FOR DECENT SURFACE HEATING TO OCCUR THIS
AFTERNOON IN ADVANCE OF SLOWLY LIFTING WARM FRONT. IT IS THIS AREA
WHICH WILL NEED TO BE WATCHED FOR ADDITIONAL SHOWER/STORM
DEVELOPMENT LATE THIS AFTERNOON AND EARLY EVENING AS MOISTURE
CONTINUES TO POOL NORTHWARD ALONG THE BOUNDARY AND INSTABILITY
INCREASES PER RENEWED SUNSHINE. BOTH NAM AND GFS CONTINUE TO PROG
CAPES BETWEEN 500-1000 J/KG WITHIN AREA OF MAXIMIZED LOW LEVEL
CONVERGENCE ALONG THE FRONT...AND THIS APPEARS PLAUSIBLE GIVEN
UPSTREAM DEW POINTS SURGING INTO THE MID/UPPER 50S. THIS SUPPORTS
THE POTENTIAL FOR ISOLATED THUNDERSTORM DEVELOPMENT SOUTHWESTERN
CWA LATE THIS AFTERNOON AND EVENING ALONG THE LIFTING
BOUNDARY...THOUGH DO NOT EXPECT WIDESPREAD DEVELOPMENT AS OVERALL
FORCING CONFINED WELL NORTH WITH MAIN UPPER SYSTEM AND MAY WELL NOT
SEE ANYTHING GIVEN RESIDUAL MID LEVEL CAPPING INVERSION PER RECENT
AIRCRAFT SOUNDINGS. IN ANY CASE...ANY STORMS THAT MANAGE TO DEVELOP
WILL HAVE TO BE WATCHED FOR SMALL SEVERE POTENTIAL WITH RELATIVELY
LOW FREEZING LEVELS/WBZ HEIGHTS AS WELL AS INCREASING SHEAR
ALOFT...WITH EFFECTIVE 0-6KM FLOW AROUND 40 KNOTS...THOUGH AGAIN
APPEARS BEST CHANCES FOR PRECIP WILL BE MAINLY SOUTH OF THE AREA.
MAIN SHOW APPEARS LIKELY TONIGHT AS POTENT UPPER WAVE TRACKS OUT OF
THE UPPER MIDWEST AND NEARLY OVERHEAD BY 12Z TOMORROW. STRONG
QG-CONVERGENCE FORCING NOTED IN ASSOCIATION WITH THE WAVE SHOULD
DRIVE AN AREA OF SHOWERS AND THUNDERSTORMS...DEVELOPING UPSTREAM
THIS EVENING IN INCREASINGLY UNSTABLE WARM SECTOR...ACROSS THE
ENTIRE CWA HEADING INTO THE OVERNIGHT. INCREASING DIFLUENCE ALOFT IN
ASSOCIATION WITH APPROACHING WAVE AND LEFT EXIT OF 110 KT JETLET
JUST SOUTH OF THE REGION WILL CONTRIBUTE TO A FAVORABLE ENVIRONMENT
FOR CONTINUED EASTWARD PROGRESSION OF CONVECTION...THOUGH BECOMING
MORE ELEVATED WITH TIME AS BOUNDARY LAYER STABILIZES. NEVERTHELESS...
APPEARS A HAIL THREAT MAY CONTINUE WITH THE STORMS AS THEY MOVE
THROUGH THE CWA...OWING MAINLY TO A STEEPENING OF LAPSE RATES WITH
APPROACH OF UPPER COLD POOL AND LIKELY ORGANIZATION OF CONVECTION
WITH EFFECTIVE SHEAR ON THE ORDER OF 30 KNOTS OR BETTER DESPITE
STABILIZED BOUNDARY LAYER. FORECAST RAOBS SHOW THIS POTENTIAL AS
WELL WITH FREEZING LEVELS HOLDING AROUND 10KFT AND WBZ HEIGHTS
AROUND 8500 FT...WITH STEEPEST LAPSE RATES RESIDING BETWEEN ABOUT 0C
AND -15C. WIND THREAT ALMOST NEGLIGIBLE GIVEN STABILITY DOWN LOW.
TEMPS TONIGHT LIKELY TO GO NOWHERE GIVEN INCREASING CLOUD COVER AND
CONTINUED WARM/MOISTURE ADVECTION AHEAD OF APPROACHING SYSTEM...AND
WILL HOLD LOWS MID 40S TO 50 FOR MANY SPOTS BANKING ON WARM AIR
OVERTAKING THOSE AREAS CURRENTLY STUCK IN THE 30S/40S THIS
AFTERNOON.
PRECIP LOOKS TO COME TO AN END FAIRLY QUICKLY TOMORROW AS UPPER WAVE
AND ASSOCIATED WEAK COOL FRONT ADVANCE EAST OF THE AREA...WITH
MID/UPPER LEVEL QG-DIVERGENCE TAKING HOLD AS SHORTWAVE RIDGE BUILDS
OVERHEAD. NOT MUCH OF A PUSH WITH FRONT TO SCOUR REMAINING LOW LEVEL
MOISTURE AS RIDGE AXIS LAGS BEHIND...AND THIS REMAINS THE CONCERN
FOR TOMORROW WITH DEGREE OF REMAINING CLOUD COVER IN QUESTION.
POTENTIAL EXISTS FOR QUITE A WARM DAY WITH DECENT MIXING AND ONLY
WEAK COLD ADVECTION BEHIND DEPARTING SYSTEM...HOWEVER APPEARS CLOUDS
WILL GET STUCK FOR AT LEAST A TIME WITH MOISTURE TRAPPED UNDER
INCREASING SUBSIDENCE INVERSION. THUS WILL RUN WITH HIGHS MAINLY IN
THE 50S NORTH TO MID 60S SOUTH...THOUGH COULD ENVISION QUITE A FEW
READINGS NEAR 70 NORTHERN LOWER SHOULD CLOUDS CLEAR FASTER THAN
EXPECTED.
LAWRENCE
LATER PERIODS...SIMILAR PROBLEMS CONTINUE TO PLAGUE THE LONG TERM AS
THEY DID YESTERDAY. THE INITIAL FOCUS FIRST LIES WITH A SOUTHERN
STREAM WAVE AND ITS ASSOCIATED SURGE OF MOISTURE LATE TUESDAY
AFTERNOON INTO WEDNESDAY. THEN THE ATTENTION TURNS TO A LARGE
TROUGH AS IT APPROACHES THE GREAT LAKES LATE THURSDAY INTO
SATURDAY. MODELS ARE IN DECENT AGREEMENT THROUGH ABOUT WEDNESDAY
BEFORE DETAILS OF THE WESTERN TROUGH BECOME MUDDIED. TEMPERATURES
WILL REMAIN ABOVE NORMAL THROUGH THE END OF THE WEEK WITH THE SPLIT
FLOW EARLY...AND THE BUILDING RIDGE LATE. TEMPERATURES LOOK TO
RETURN TO NORMAL BY NEXT WEEKEND AS THE UPPER TROUGH PASSES OVER THE
GREAT LAKES.
MONDAY NIGHT INTO TUESDAY...WITH THE SHORTWAVE MOVING TO THE
NORTHEAST UNITED STATES...A CANADIAN HIGH PRESSURE OVER MANITOBA AND
ONTARIO WILL HELP PUSH A COLD FRONT ACROSS THE STATE AS IT BUILDS
SOUTH. ABSENCE OF UPPER LEVEL SUPPORT AND MOISTURE WILL PREVENT
ANY PRECIP FROM FORMING...BUT INCREASING SUBSIDENCE ALOFT WILL TRAP
MOISTURE BELOW THE INVERSION TO FORM LOW STRATUS OR FOG...ESPECIALLY
OVERNIGHT WHEN WINDS GO LIGHT. THE FRONT SETTLES TO THE SOUTH OVER
THE FAR SOUTHERN GREAT LAKES TO START THE DAY. BELIEVE FOG AND
STRATUS WILL MIX OUT BY MID-MORNING SINCE THE MOISTURE DEPTH IS
FAIRLY SHALLOW (ONLY 2-3KFT). HOWEVER...DEEP MOISTURE AHEAD OF A SW
SHORTWAVE WILL ADVECT NORTHEAST TOWARDS THE GREAT LAKES. 850MB
MOISTURE CONVERGENCE WILL SLOWLY PUSH TOWARDS NORTHERN MICHIGAN AS
THE WAVE DRAWS CLOSER. THE NAM BRINGS THE 850MB CONVERGENCE AND
PRECIP FARTHER NORTH...GENERALLY SOUTH OF M-72 WHILE THE GFS KEEPS
THE PRECIP ACROSS CENTRAL LOWER BY LATE AFTERNOON. WILL TEND TO
SIDE WITH THE DRIER GFS HERE AS THE MID-LEVELS MAY HAVE A HARD TIME
SATURATING WITH THE DRY AIR PRESENT...AND WILL TRIM POPS SOUTH
DURING THE AFTERNOON ACCORDINGLY. HIGHS WILL BE TRICKY WITH THE
FOG/STRATUS IN THE MORNING...AND CLOUDS MOVING IN AGAIN DURING THE
REST OF THE DAY. MIDDLE TO UPPER 50S STILL LOOK GOOD.
TUESDAY NIGHT INTO WEDNESDAY...SHORTWAVE WITHIN THE SOUTHERN BRANCH
WILL WEAKEN AS IT TRACKS NE TOWARDS THE GREAT LAKES. THIS TROUGH
WILL BRING A SURGE OF DEEP LAYER MOISTURE WITH IT BUT WILL RUN INTO
DRY AIR ORIGINATING FROM A SURFACE HIGH OVER HUDSON BAY. NOT
SURPRISING...NAM/GFS ARE LESS AGGRESSIVE BRINGING THE PRECIPITATION
NORTH THAN YESTERDAYS RUN WHICH LEAVES ALL OF EASTERN UPPER AND
PARTS OF NORTHEAST LOWER DRY. CURRENT POP SITUATION LOOKS GOOD FOR
NOW BUT WOULD NOT BE SURPRISED TO SEE POPS TRIMMED SOUTH TUESDAY
NIGHT AS THE DRY AIR MAY SLOW THE PROGRESSION OF THE PRECIP
INITIALLY. THUNDER CHANCES ONLY LOOK MARGINAL DUE TO 700-500MB
LAPSE RATES BETWEEN 5.5-6.0 C/KM. MOISTURE CONTINUES TO SURGE
SLOWLY NORTHEAST ON WEDNESDAY...IMPEDED BY THE DRY AIR TO THE
NORTH. EASTERN UPPER CONTINUES TO LOOK DRY WITH THE 850MB MOISTURE
CONVERGENCE REMAINING TO THE SOUTH OVER CENTRAL LOWER SO WILL LEAVE
NORTHERN LOWER WITH A CHANCE OF RAIN. DESPITE THE CLOUD COVER...HIGHS ON
WEDNESDAY STILL LOOK TO REMAIN IN THE 50S.
WEDNESDAY NIGHT THROUGH SUNDAY...MANY FORECAST CHALLENGES CONTINUE
TO PLAGUE THE DAYS 4-7 PERIOD INCLUDING EVOLUTION OF A LARGE TROUGH
THAT EMERGES OVER THE PLAINS AND THE MOVEMENT OF A BOUNDARY THATS
HUNG UP OVER THE FAR SOUTHERN GREAT LAKES. MODELS ARE NOT IN THE
BEST AGREEMENT OVER THIS STRETCH WITH THE ECMWF DEVELOPING A
STRONGER/SLOWER CLOSED LOW OVER THE ROCKIES WHILE THE GFS/CANADIAN
ENSEMBLES SHOW A WEAKER/FASTER TROUGH THAT MOVES ACROSS THE NORTHERN
PLAINS. WILL STICK WITH THE GFS/CANADIAN ENSEMBLES FOR FROPA TIMING
FRIDAY INTO SATURDAY WHO SEEM TO SHOW BETTER CONTINUITY DURING THIS
FORECAST PERIOD. WEAKENING MOISTURE ADVECTION WEDNESDAY NIGHT
CONTINUES TO BE PROBLEMATIC DUE TO THE LOW LEVEL DRY AIR FLOW
ORIGINATING FROM THE HUDSON BAY HIGH TO THE NORTH AS WELL AS DRY
AIR ALOFT WITH THE 500MB RIDGE MOVING OVERHEAD. ADDITIONALLY...850MB
CONVERGENCE ALSO LOOKS TO SUBSIDE SOMEWHAT AS WINDS TURN MORE
PARALLEL TO THE THETA-E CONTOURS. WOULD PREFER TO KEEP
CONTINUITY...BUT WILL REMOVE POPS FOR COORDINATION PURPOSES.
ATTENTION THEN TURNS TO THE PLAINS ON THURSDAY AS A STRONG UPPER
TROUGH PUSHES A COLD FRONT TOWARDS THE STATE. SOUTHERLY WINDS RAMP
UP HELPING TO PUSH 850MB TEMPERATURES TO +10C. THURSDAY HAS THE
POTENTIAL TO BE A REALLY WARM DAY DEPENDING ON THE CLOUD COVER
ADVECTED IN FROM THE SOUTH. COLD FRONT THEN LOOKS TO ARRIVE LATE
THURSDAY NITE INTO FRI. TIMING HAS BEEN SLIGHTLY SLOWER THEN
YESTERDAY AND WILL EXTEND PRECIP CHANCES INTO SATURDAY AS THE
UPPER LEVEL TROUGH PASSES OVER NORTHERN MICHIGAN. HIGH PRESSURE
AND COLDER AIR MOVE IN BEHIND THE FRONT WITH 1000-500 THICKNESSES
FALLING BELOW 540DM AND TEMPERATURES AT OR BELOW NORMAL.
MPC
&&
.APX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
725 PM EDT SUN MAR 25 2007
.AVIATION...VFR CIGS AND VSBYS WILL PERSIST THRU MOST OF THE EVENING
ACROSS NRN LOWER MICHIGAN. A PERIOD OF LOW LEVEL WIND SHEAR IS
EXPECTED AT PLN/TVC/APN AFTER SUNSET AS SFC WINDS DIMINISH BUT WINDS
ABOVE THE SURFACE INCREASE TO 35 TO 40 KNOTS IN ADVANCE OF A
VIGOROUS LOW PRESSURE SYSTEM AND COLD FRONT MOVING INTO THE WRN
GREAT LAKES REGION. THIS SYSTEM IS ALSO EXPECTED TO BRING A ROUND OF
WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE PLN/TVC/APN AREAS LATE THIS
EVENING AND OVERNIGHT...WITH THE BEST COVERAGE OF PRECIP ANTICIPATED
BETWEEN 05Z AND 09Z. LIGHTER SHOWERS/MVFR AND POSSIBLE IFR
CEILINGS/VSBYS THEN LINGER BEHIND THE FRONT THROUGH MONDAY MID TO
LATE MORNING. A FEW SHOWERS WILL LINGER AROUND APN INTO THE
AFTERNOON. PARTIAL CLEARING WILL TAKE PLACE AT PLN AND TVC IN THE
AFTERNOON...WITH A RETURN TO DRY WEATHER AND VFR CONDITIONS.
&&
.DISCUSSION...ISSUED 355 PM EDT SUN MAR 25 2007
MAIN CONCERN THIS GO AROUND FOCUSED ON CONVECTIVE POTENTIAL. EARLY
AFTERNOON ANALYSIS SHOWS POTENT UPPER SYSTEM CROSSING INTO WESTERN
MINNESOTA...WITH SURFACE REFLECTION ACROSS NORTHEAST SOUTH
DAKOTA...AND ATTENDANT WARM FRONT DRAPED INTO FAR SOUTHERN MICHIGAN.
INITIAL BAND OF PRECIPITATION...ASSOCIATED WITH STRONG SURGE OF WARM
ADVECTION...PUSHING THROUGH THE NORTHERN CWA AT THIS TIME...AND
EXPECT THIS WILL BE OUT OF THE PICTURE NEAR THE START OF THE NEW
FORECAST PERIOD. PRONOUNCED CLEAR SLOT HAS DEVELOPED OVER THE
SOUTHWESTERN CWA...ALLOWING FOR DECENT SURFACE HEATING TO OCCUR THIS
AFTERNOON IN ADVANCE OF SLOWLY LIFTING WARM FRONT. IT IS THIS AREA
WHICH WILL NEED TO BE WATCHED FOR ADDITIONAL SHOWER/STORM
DEVELOPMENT LATE THIS AFTERNOON AND EARLY EVENING AS MOISTURE
CONTINUES TO POOL NORTHWARD ALONG THE BOUNDARY AND INSTABILITY
INCREASES PER RENEWED SUNSHINE. BOTH NAM AND GFS CONTINUE TO PROG
CAPES BETWEEN 500-1000 J/KG WITHIN AREA OF MAXIMIZED LOW LEVEL
CONVERGENCE ALONG THE FRONT...AND THIS APPEARS PLAUSIBLE GIVEN
UPSTREAM DEW POINTS SURGING INTO THE MID/UPPER 50S. THIS SUPPORTS
THE POTENTIAL FOR ISOLATED THUNDERSTORM DEVELOPMENT SOUTHWESTERN
CWA LATE THIS AFTERNOON AND EVENING ALONG THE LIFTING
BOUNDARY...THOUGH DO NOT EXPECT WIDESPREAD DEVELOPMENT AS OVERALL
FORCING CONFINED WELL NORTH WITH MAIN UPPER SYSTEM AND MAY WELL NOT
SEE ANYTHING GIVEN RESIDUAL MID LEVEL CAPPING INVERSION PER RECENT
AIRCRAFT SOUNDINGS. IN ANY CASE...ANY STORMS THAT MANAGE TO DEVELOP
WILL HAVE TO BE WATCHED FOR SMALL SEVERE POTENTIAL WITH RELATIVELY
LOW FREEZING LEVELS/WBZ HEIGHTS AS WELL AS INCREASING SHEAR
ALOFT...WITH EFFECTIVE 0-6KM FLOW AROUND 40 KNOTS...THOUGH AGAIN
APPEARS BEST CHANCES FOR PRECIP WILL BE MAINLY SOUTH OF THE AREA.
MAIN SHOW APPEARS LIKELY TONIGHT AS POTENT UPPER WAVE TRACKS OUT OF
THE UPPER MIDWEST AND NEARLY OVERHEAD BY 12Z TOMORROW. STRONG
QG-CONVERGENCE FORCING NOTED IN ASSOCIATION WITH THE WAVE SHOULD
DRIVE AN AREA OF SHOWERS AND THUNDERSTORMS...DEVELOPING UPSTREAM
THIS EVENING IN INCREASINGLY UNSTABLE WARM SECTOR...ACROSS THE
ENTIRE CWA HEADING INTO THE OVERNIGHT. INCREASING DIFLUENCE ALOFT IN
ASSOCIATION WITH APPROACHING WAVE AND LEFT EXIT OF 110 KT JETLET
JUST SOUTH OF THE REGION WILL CONTRIBUTE TO A FAVORABLE ENVIRONMENT
FOR CONTINUED EASTWARD PROGRESSION OF CONVECTION...THOUGH BECOMING
MORE ELEVATED WITH TIME AS BOUNDARY LAYER STABILIZES. NEVERTHELESS...
APPEARS A HAIL THREAT MAY CONTINUE WITH THE STORMS AS THEY MOVE
THROUGH THE CWA...OWING MAINLY TO A STEEPENING OF LAPSE RATES WITH
APPROACH OF UPPER COLD POOL AND LIKELY ORGANIZATION OF CONVECTION
WITH EFFECTIVE SHEAR ON THE ORDER OF 30 KNOTS OR BETTER DESPITE
STABILIZED BOUNDARY LAYER. FORECAST RAOBS SHOW THIS POTENTIAL AS
WELL WITH FREEZING LEVELS HOLDING AROUND 10KFT AND WBZ HEIGHTS
AROUND 8500 FT...WITH STEEPEST LAPSE RATES RESIDING BETWEEN ABOUT 0C
AND -15C. WIND THREAT ALMOST NEGLIGIBLE GIVEN STABILITY DOWN LOW.
TEMPS TONIGHT LIKELY TO GO NOWHERE GIVEN INCREASING CLOUD COVER AND
CONTINUED WARM/MOISTURE ADVECTION AHEAD OF APPROACHING SYSTEM...AND
WILL HOLD LOWS MID 40S TO 50 FOR MANY SPOTS BANKING ON WARM AIR
OVERTAKING THOSE AREAS CURRENTLY STUCK IN THE 30S/40S THIS
AFTERNOON.
PRECIP LOOKS TO COME TO AN END FAIRLY QUICKLY TOMORROW AS UPPER WAVE
AND ASSOCIATED WEAK COOL FRONT ADVANCE EAST OF THE AREA...WITH
MID/UPPER LEVEL QG-DIVERGENCE TAKING HOLD AS SHORTWAVE RIDGE BUILDS
OVERHEAD. NOT MUCH OF A PUSH WITH FRONT TO SCOUR REMAINING LOW LEVEL
MOISTURE AS RIDGE AXIS LAGS BEHIND...AND THIS REMAINS THE CONCERN
FOR TOMORROW WITH DEGREE OF REMAINING CLOUD COVER IN QUESTION.
POTENTIAL EXISTS FOR QUITE A WARM DAY WITH DECENT MIXING AND ONLY
WEAK COLD ADVECTION BEHIND DEPARTING SYSTEM...HOWEVER APPEARS CLOUDS
WILL GET STUCK FOR AT LEAST A TIME WITH MOISTURE TRAPPED UNDER
INCREASING SUBSIDENCE INVERSION. THUS WILL RUN WITH HIGHS MAINLY IN
THE 50S NORTH TO MID 60S SOUTH...THOUGH COULD ENVISION QUITE A FEW
READINGS NEAR 70 NORTHERN LOWER SHOULD CLOUDS CLEAR FASTER THAN
EXPECTED.
LAWRENCE
LATER PERIODS...SIMILAR PROBLEMS CONTINUE TO PLAGUE THE LONG TERM AS
THEY DID YESTERDAY. THE INITIAL FOCUS FIRST LIES WITH A SOUTHERN
STREAM WAVE AND ITS ASSOCIATED SURGE OF MOISTURE LATE TUESDAY
AFTERNOON INTO WEDNESDAY. THEN THE ATTENTION TURNS TO A LARGE
TROUGH AS IT APPROACHES THE GREAT LAKES LATE THURSDAY INTO
SATURDAY. MODELS ARE IN DECENT AGREEMENT THROUGH ABOUT WEDNESDAY
BEFORE DETAILS OF THE WESTERN TROUGH BECOME MUDDIED. TEMPERATURES
WILL REMAIN ABOVE NORMAL THROUGH THE END OF THE WEEK WITH THE SPLIT
FLOW EARLY...AND THE BUILDING RIDGE LATE. TEMPERATURES LOOK TO
RETURN TO NORMAL BY NEXT WEEKEND AS THE UPPER TROUGH PASSES OVER THE
GREAT LAKES.
MONDAY NIGHT INTO TUESDAY...WITH THE SHORTWAVE MOVING TO THE
NORTHEAST UNITED STATES...A CANADIAN HIGH PRESSURE OVER MANITOBA AND
ONTARIO WILL HELP PUSH A COLD FRONT ACROSS THE STATE AS IT BUILDS
SOUTH. ABSENCE OF UPPER LEVEL SUPPORT AND MOISTURE WILL PREVENT
ANY PRECIP FROM FORMING...BUT INCREASING SUBSIDENCE ALOFT WILL TRAP
MOISTURE BELOW THE INVERSION TO FORM LOW STRATUS OR FOG...ESPECIALLY
OVERNIGHT WHEN WINDS GO LIGHT. THE FRONT SETTLES TO THE SOUTH OVER
THE FAR SOUTHERN GREAT LAKES TO START THE DAY. BELIEVE FOG AND
STRATUS WILL MIX OUT BY MID-MORNING SINCE THE MOISTURE DEPTH IS
FAIRLY SHALLOW (ONLY 2-3KFT). HOWEVER...DEEP MOISTURE AHEAD OF A SW
SHORTWAVE WILL ADVECT NORTHEAST TOWARDS THE GREAT LAKES. 850MB
MOISTURE CONVERGENCE WILL SLOWLY PUSH TOWARDS NORTHERN MICHIGAN AS
THE WAVE DRAWS CLOSER. THE NAM BRINGS THE 850MB CONVERGENCE AND
PRECIP FARTHER NORTH...GENERALLY SOUTH OF M-72 WHILE THE GFS KEEPS
THE PRECIP ACROSS CENTRAL LOWER BY LATE AFTERNOON. WILL TEND TO
SIDE WITH THE DRIER GFS HERE AS THE MID-LEVELS MAY HAVE A HARD TIME
SATURATING WITH THE DRY AIR PRESENT...AND WILL TRIM POPS SOUTH
DURING THE AFTERNOON ACCORDINGLY. HIGHS WILL BE TRICKY WITH THE
FOG/STRATUS IN THE MORNING...AND CLOUDS MOVING IN AGAIN DURING THE
REST OF THE DAY. MIDDLE TO UPPER 50S STILL LOOK GOOD.
TUESDAY NIGHT INTO WEDNESDAY...SHORTWAVE WITHIN THE SOUTHERN BRANCH
WILL WEAKEN AS IT TRACKS NE TOWARDS THE GREAT LAKES. THIS TROUGH
WILL BRING A SURGE OF DEEP LAYER MOISTURE WITH IT BUT WILL RUN INTO
DRY AIR ORIGINATING FROM A SURFACE HIGH OVER HUDSON BAY. NOT
SURPRISING...NAM/GFS ARE LESS AGGRESSIVE BRINGING THE PRECIPITATION
NORTH THAN YESTERDAYS RUN WHICH LEAVES ALL OF EASTERN UPPER AND
PARTS OF NORTHEAST LOWER DRY. CURRENT POP SITUATION LOOKS GOOD FOR
NOW BUT WOULD NOT BE SURPRISED TO SEE POPS TRIMMED SOUTH TUESDAY
NIGHT AS THE DRY AIR MAY SLOW THE PROGRESSION OF THE PRECIP
INITIALLY. THUNDER CHANCES ONLY LOOK MARGINAL DUE TO 700-500MB
LAPSE RATES BETWEEN 5.5-6.0 C/KM. MOISTURE CONTINUES TO SURGE
SLOWLY NORTHEAST ON WEDNESDAY...IMPEDED BY THE DRY AIR TO THE
NORTH. EASTERN UPPER CONTINUES TO LOOK DRY WITH THE 850MB MOISTURE
CONVERGENCE REMAINING TO THE SOUTH OVER CENTRAL LOWER SO WILL LEAVE
NORTHERN LOWER WITH A CHANCE OF RAIN. DESPITE THE CLOUD COVER...HIGHS ON
WEDNESDAY STILL LOOK TO REMAIN IN THE 50S.
WEDNESDAY NIGHT THROUGH SUNDAY...MANY FORECAST CHALLENGES CONTINUE
TO PLAGUE THE DAYS 4-7 PERIOD INCLUDING EVOLUTION OF A LARGE TROUGH
THAT EMERGES OVER THE PLAINS AND THE MOVEMENT OF A BOUNDARY THATS
HUNG UP OVER THE FAR SOUTHERN GREAT LAKES. MODELS ARE NOT IN THE
BEST AGREEMENT OVER THIS STRETCH WITH THE ECMWF DEVELOPING A
STRONGER/SLOWER CLOSED LOW OVER THE ROCKIES WHILE THE GFS/CANADIAN
ENSEMBLES SHOW A WEAKER/FASTER TROUGH THAT MOVES ACROSS THE NORTHERN
PLAINS. WILL STICK WITH THE GFS/CANADIAN ENSEMBLES FOR FROPA TIMING
FRIDAY INTO SATURDAY WHO SEEM TO SHOW BETTER CONTINUITY DURING THIS
FORECAST PERIOD. WEAKENING MOISTURE ADVECTION WEDNESDAY NIGHT
CONTINUES TO BE PROBLEMATIC DUE TO THE LOW LEVEL DRY AIR FLOW
ORIGINATING FROM THE HUDSON BAY HIGH TO THE NORTH AS WELL AS DRY
AIR ALOFT WITH THE 500MB RIDGE MOVING OVERHEAD. ADDITIONALLY...850MB
CONVERGENCE ALSO LOOKS TO SUBSIDE SOMEWHAT AS WINDS TURN MORE
PARALLEL TO THE THETA-E CONTOURS. WOULD PREFER TO KEEP
CONTINUITY...BUT WILL REMOVE POPS FOR COORDINATION PURPOSES.
ATTENTION THEN TURNS TO THE PLAINS ON THURSDAY AS A STRONG UPPER
TROUGH PUSHES A COLD FRONT TOWARDS THE STATE. SOUTHERLY WINDS RAMP
UP HELPING TO PUSH 850MB TEMPERATURES TO +10C. THURSDAY HAS THE
POTENTIAL TO BE A REALLY WARM DAY DEPENDING ON THE CLOUD COVER
ADVECTED IN FROM THE SOUTH. COLD FRONT THEN LOOKS TO ARRIVE LATE
THURSDAY NITE INTO FRI. TIMING HAS BEEN SLIGHTLY SLOWER THEN
YESTERDAY AND WILL EXTEND PRECIP CHANCES INTO SATURDAY AS THE
UPPER LEVEL TROUGH PASSES OVER NORTHERN MICHIGAN. HIGH PRESSURE
AND COLDER AIR MOVE IN BEHIND THE FRONT WITH 1000-500 THICKNESSES
FALLING BELOW 540DM AND TEMPERATURES AT OR BELOW NORMAL.
MPC
&&
.APX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
355 PM EDT SUN MAR 25 2007
.DISCUSSION...MAIN CONCERS THIS GO AROUND FOCUSED ON CONVECTIVE
POTENTIAL. EARLY AFTERNOON ANALYSIS SHOWS POTENT UPPER SYSTEM
CROSSING INTO WESTERN MINNESOTA...WITH SURFACE REFLECTION ACROSS
NORTHEAST SOUTH DAKOTA...AND ATTENDANT WARM FRONT DRAPED INTO FAR
SOUTHERN MICHIGAN. INITIAL BAND OF PRECIPITATION...ASSOCIATED WITH
STRONG SURGE OF WARM ADVECTION...PUSHING THROUGH THE NORTHERN CWA AT
THIS TIME...AND EXPECT THIS WILL BE OUT OF THE PICTURE NEAR THE
START OF THE NEW FORECAST PERIOD. PRONOUNCED CLEAR SLOT HAS
DEVELOPED OVER THE SOUTHWESTERN CWA...ALLOWING FOR DECENT SUFRACE
HEATING TO OCCUR THIS AFTERNOON IN ADVANCE OF SLOWLY LIFTING WARM
FRONT. IT IS THIS AREA WHICH WILL NEED TO BE WATCHED FOR ADDITIONAL
SHOWER/STORM DEVELOPMENT LATE THIS AFTERNOON AND EARLY EVENING AS
MOISTURE CONTINUES TO POOL NORTHWARD ALONG THE BOUNDARY AND
INSTABILITY INCREASES PER RENEWED SUNSHINE. BOTH NAM AND GFS
CONTINUE TO PROG CAPES BETWEEN 500-1000 J/KG WITHIN AREA OF
MAXIMIZED LOW LEVEL CONVERGENCE ALONG THE FRONT...AND THIS APPEARS
PLAUSIBLE GIVEN UPSTREAM DEW POINTS SURGING INTO THE MID/UPPER 50S.
THIS SUPPORTS THE POTENTIAL FOR ISOLATED THUNDERSTORM DEVELOPMENT
SOUTHERWESTERN CWA LATE THIS AFTERNOON AND EVENING ALONG THE LIFTING
BOUNDARY...THOUGH DO NOT EXPECT WIDESPREAD DEVELOPMENT AS OVERALL
FORCING CONFINED WELL NORTH WITH MAIN UPPER SYSTEM AND MAY WELL NOT
SEE ANYTHING GIVEN RESIDUAL MID LEVEL CAPPING INVERSION PER RECENT
AIRCRAFT SOUNDINGS. IN ANY CASE...ANY STORMS THAT MANAGE TO DEVELOP
WILL HAVE TO BE WATCHED FOR SMALL SEVERE POTENTIAL WITH RELATIVELY
LOW FREEZING LEVELS/WBZ HEIGHTS AS WELL AS INCREASING SHEAR
ALOFT...WITH EFFECTIVE 0-6KM FLOW AROUND 40 KNOTS...THOUGH AGAIN
APPEARS BESTT CHANCES FOR PRECIP WILL BE MAINLY SOUTH OF THE AREA.
MAIN SHOW APPEARS LIKELY TONIGHT AS POTENT UPPER WAVE TRACKS OUT OF
THE UPPER MIDWEST AND NEARLY OVERHEAD BY 12Z TOMORROW. STRONG
QG-CONVERGENCE FORCING NOTED IN ASSOCIATION WITH THE WAVE SHOULD
DRIVE AN AREA OF SHOWERS AND THUNDERSTORMS...DEVELOPING UPSTREAM
THIS EVENING IN INCREASINGLY UNSTABLE WARM SECTOR...ACROSS THE
ENTIRE CWA HEADING INTO THE OVERNIGHT. INCREASING DIFLUENCE ALOFT IN
ASSOCIATION WITH APPROACHING WAVE AND LEFT EXIT OF 110 KT JETLET
JUST SOUTH OF THE REGION WILL CONTRIBUTE TO A FAVORABLE ENVIRONMENT
FOR CONTINUED EASTWARD PROGRESSION OF CONVECTION...THOUGH BECOMING
MORE ELEVATED WITH TIME AS BOUNDARY LAYER STABILIZES. NEVERTHELESS...
APPEARS A HAIL THREAT MAY CONTINUE WITH THE STORMS AS THEY MOVE
THROUGH THE CWA...OWING MAINLY TO A STEEPENING OF LAPSE RATES WITH
APPROACH OF UPPER COLD POOL AND LIKELY ORGANIZATION OF CONVECTION
WITH EFFECTIVE SHEAR ON THE ORDER OF 30 KNOTS OR BETTER DESPITE
STABILIZED BOUNDARY LAYER. FORECAST RAOBS SHOW THIS POTENTIAL AS
WELL WITH FREEZING LEVELS HOLDING AROUND 10KFT AND WBZ HEIGHTS
AROUND 8500 FT...WITH STEEPEST LAPSE RATES RESIDING BETWEEN ABOUT 0C
AND -15C. WIND THREAT ALMOST NEGLIGIBLE GIVEN STABILITY DOWN LOW.
TEMPS TONIGHT LIKELY TO GO NOWHERE GIVEN INCREASING CLOUD COVER AND
CONTINUED WARM/MOISTURE ADVECTION AHEAD OF APPROACHING SYSTEM...AND
WILL HOLD LOWS MID 40S TO 50 FOR MANY SPOTS BANKING ON WARM AIR
OVERTAKING THOSE AREAS CURRENTLY STUCK IN THE 30S/40S THIS
AFTERNOON.
PRECIP LOOKS TO COME TO AN END FAIRLY QUICKLY TOMORROW AS UPPER WAVE
AND ASSOCIATED WEAK COOL FRONT ADVANCE EAST OF THE AREA...WITH
MID/UPPER LEVEL QG-DIVERGENCE TAKING HOLD AS SHORTWAVE RIDGE BUILDS
OVERHEAD. NOT MUCH OF A PUSH WITH FRONT TO SCOUR REMAINING LOW LEVEL
MOISTURE AS RIDGE AXIS LAGS BEHIND...AND THIS REMAINS THE CONCERN
FOR TOMORROW WITH DEGREE OF REMAINING CLOUD COVER IN QUESTION.
POTENTIAL EXISTS FOR QUITE A WARM DAY WITH DECENT MIXING AND ONLY
WEAK COLD ADVECTION BEHIND DEPARING SYSTEM...HOWEVER APPEARS CLOUDS
WILL GET STUCK FOR AT LEAST A TIME WITH MOISTURE TRAPPED UNDER
INCREASING SUBSIDENCE INVERSION. THUS WILL RUN WITH HIGHS MAINLY IN
THE 50S NORTH TO MID 60S SOUTH...THOUGH COULD ENVISION QUITE A FEW
READINGS NEAR 70 NORTHERN LOWER SHOULD CLOUDS CLEAR FASTER THAN
EXPECTED.
LAWRENCE
LATER PERIODS...SIMILAR PROBLEMS CONTINUE TO PLAGUE THE LONG TERM AS
THEY DID YESTERDAY. THE INITIAL FOCUS FIRST LIES WITH A SOUTHERN
STREAM WAVE AND ITS ASSOCIATED SURGE OF MOISTURE LATE TUESDAY
AFTERNOON INTO WEDNESDAY. THEN THE ATTENTION TURNS TO A LARGE
TROUGH AS IT APPROACHES THE GREAT LAKES LATE THURSDAY INTO
SATURDAY. MODELS ARE IN DECENT AGREEMENT THROUGH ABOUT WEDNESDAY
BEFORE DETAILS OF THE WESTERN TROUGH BECOME MUDDIED. TEMPERATURES
WILL REMAIN ABOVE NORMAL THROUGH THE END OF THE WEEK WITH THE SPLIT
FLOW EARLY...AND THE BUILDING RIDGE LATE. TEMPERATURES LOOK TO
RETURN TO NORMAL BY NEXT WEEKEND AS THE UPPER TROUGH PASSES OVER THE
GREAT LAKES.
MONDAY NIGHT INTO TUESDAY...WITH THE SHORTWAVE MOVING TO THE
NORTHEAST UNITED STATES...A CANADIAN HIGH PRESSURE OVER MANITOBA AND
ONTARIO WILL HELP PUSH A COLD FRONT ACROSS THE STATE AS IT BUILDS
SOUTH. ABSENCE OF UPPER LEVEL SUPPORT AND MOISTURE WILL PREVENT
ANY PRECIP FROM FORMING...BUT INCREASING SUBSIDENCE ALOFT WILL TRAP
MOISTURE BELOW THE INVERSION TO FORM LOW STRATUS OR FOG...ESPECIALLY
OVERNIGHT WHEN WINDS GO LIGHT. THE FRONT SETTLES TO THE SOUTH OVER
THE FAR SOUTHERN GREAT LAKES TO START THE DAY. BELIEVE FOG AND
STRATUS WILL MIX OUT BY MID-MORNING SINCE THE MOISTURE DEPTH IS
FAIRLY SHALLOW (ONLY 2-3KFT). HOWEVER...DEEP MOISTURE AHEAD OF A SW
SHORTWAVE WILL ADVECT NORTHEAST TOWARDS THE GREAT LAKES. 850MB
MOISTURE CONVERGENCE WILL SLOWLY PUSH TOWARDS NORTHERN MICHIGAN AS
THE WAVE DRAWS CLOSER. THE NAM BRINGS THE 850MB CONVERGENCE AND
PRECIP FARTHER NORTH...GENERALLY SOUTH OF M-72 WHILE THE GFS KEEPS
THE PRECIP ACROSS CENTRAL LOWER BY LATE AFTERNOON. WILL TEND TO
SIDE WITH THE DRIER GFS HERE AS THE MID-LEVELS MAY HAVE A HARD TIME
SATURATING WITH THE DRY AIR PRESENT...AND WILL TRIM POPS SOUTH
DURING THE AFTERNOON ACCORDINGLY. HIGHS WILL BE TRICKY WITH THE
FOG/STRATUS IN THE MORNING...AND CLOUDS MOVING IN AGAIN DURING THE
REST OF THE DAY. MIDDLE TO UPPER 50S STILL LOOK GOOD.
TUESDAY NIGHT INTO WEDNESDAY...SHORTWAVE WITHIN THE SOUTHERN BRANCH
WILL WEAKEN AS IT TRACKS NE TOWARDS THE GREAT LAKES. THIS TROUGH
WILL BRING A SURGE OF DEEP LAYER MOISTURE WITH IT BUT WILL RUN INTO
DRY AIR ORIGINATING FROM A SURFACE HIGH OVER HUDSON BAY. NOT
SURPRISING...NAM/GFS ARE LESS AGGRESSIVE BRINGING THE PRECIPITATION
NORTH THAN YESTERDAYS RUN WHICH LEAVES ALL OF EASTERN UPPER AND
PARTS OF NORTHEAST LOWER DRY. CURRENT POP SITUATION LOOKS GOOD FOR
NOW BUT WOULD NOT BE SURPRISED TO SEE POPS TRIMMED SOUTH TUESDAY
NIGHT AS THE DRY AIR MAY SLOW THE PROGRESSION OF THE PRECIP
INITIALLY. THUNDER CHANCES ONLY LOOK MARGINAL DUE TO 700-500MB
LAPSE RATES BETWEEN 5.5-6.0 C/KM. MOISTURE CONTINUES TO SURGE
SLOWLY NORTHEAST ON WEDNESDAY...IMPEDED BY THE DRY AIR TO THE
NORTH. EASTERN UPPER CONTINUES TO LOOK DRY WITH THE 850MB MOISTURE
CONVERGENCE REMAINING TO THE SOUTH OVER CENTRAL LOWER SO WILL LEAVE
NORTHERN LOWER WITH A CHANCE OF RAIN. DESPITE THE CLOUD COVER...HIGHS ON
WEDNESDAY STILL LOOK TO REMAIN IN THE 50S.
WEDNESDAY NIGHT THROUGH SUNDAY...MANY FORECAST CHALLENGES CONTINUE
TO PLAGUE THE DAYS 4-7 PERIOD INCLUDING EVOLUTION OF A LARGE TROUGH
THAT EMERGES OVER THE PLAINS AND THE MOVEMENT OF A BOUNDARY THATS
HUNG UP OVER THE FAR SOUTHERN GREAT LAKES. MODELS ARE NOT IN THE
BEST AGREEMENT OVER THIS STRETCH WITH THE ECMWF DEVELOPING A
STRONGER/SLOWER CLOSED LOW OVER THE ROCKIES WHILE THE GFS/CANADIAN
ENSEMBLES SHOW A WEAKER/FASTER TROUGH THAT MOVES ACROSS THE NORTHERN
PLAINS. WILL STICK WITH THE GFS/CANADIAN ENSEMBLES FOR FROPA TIMING
FRIDAY INTO SATURDAY WHO SEEM TO SHOW BETTER CONTINUITY DURING THIS
FORECAST PERIOD. WEAKENING MOISTURE ADVECTION WEDNESDAY NIGHT
CONTINUES TO BE PROBLEMATIC DUE TO THE LOW LEVEL DRY AIR FLOW
ORIGINATING FROM THE HUDSON BAY HIGH TO THE NORTH AS WELL AS DRY
AIR ALOFT WITH THE 500MB RIDGE MOVING OVERHEAD. ADDITIONALLY...850MB
CONVERGENCE ALSO LOOKS TO SUBSIDE SOMEWHAT AS WINDS TURN MORE
PARALLEL TO THE THETA-E CONTOURS. WOULD PREFER TO KEEP
CONTINUITY...BUT WILL REMOVE POPS FOR COORDINATION PURPOSES.
ATTENTION THEN TURNS TO THE PLAINS ON THURSDAY AS A STRONG UPPER
TROUGH PUSHES A COLD FRONT TOWARDS THE STATE. SOUTHERLY WINDS RAMP
UP HELPING TO PUSH 850MB TEMPERATURES TO +10C. THURSDAY HAS THE
POTENTIAL TO BE A REALLY WARM DAY DEPENDING ON THE CLOUD COVER
ADVECTED IN FROM THE SOUTH. COLD FRONT THEN LOOKS TO ARRIVE LATE
THURSDAY NITE INTO FRI. TIMING HAS BEEN SLIGHTLY SLOWER THEN
YESTERDAY AND WILL EXTEND PRECIP CHANCES INTO SATURDAY AS THE
UPPER LEVEL TROUGH PASSES OVER NORTHERN MICHIGAN. HIGH PRESSURE
AND COLDER AIR MOVE IN BEHIND THE FRONT WITH 1000-500 THICKNESSES
FALLING BELOW 540DM AND TEMPERATURES AT OR BELOW NORMAL.
MPC
&&
.AVIATION...WARM FRONT LIFTING INTO LOWER MICHIGAN THIS AFTERNOON
WILL BRING SCATTERED LIGHT RAIN SHOWERS TO THE PLN/APN AREA THROUGH
19Z WITH A BRIEF PERIOD OF MVFR CEILINGS POSSIBLE THROUGH 20Z. VRF
CONDITIONS THEN RETURN (AND PERSIST AT TVC) FOR THE BALANCE OF THE
DAY AND INTO THE EARLY EVENING HOURS. A PERIOD OF LOW LEVEL WIND
SHEAR IS POSSIBLE AT PLN/TVC/APN AFTER SUNSET THIS EVENING AS SFC
WINDS DIMINISH BUT WINDS ABOVE THE SURFACE INCREASE TO 35 TO 40
KNOTS IN ADVANCE OF A VIGOROUS LOW PRESSURE SYSTEM AND COLD FRONT
COMING OUT OF THE UPPER MIDWEST. THIS SYSTEM IS ALSO EXPECTED TO
BRING A ROUND OF WIDESPREAD SHOWERS AND THUNDERSTORMS TO THE
PLN/TVC/APN AREAS LATE EVENING AND OVERNIGHT...WITH THE BEST
COVERAGE OF PRECIP ANTICIPATED BETWEEN 05Z AND 09Z. LIGHTER
SHOWERS/MVFR AND POSSIBLE IFR CEILINGS/VSBYS THEN LINGER BEHIND
THE FRONT THROUGH MONDAY MID TO LATE MORNING.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1005 AM EDT SAT MAR 24 2007
.UPDATE...WATER VAPOR IMAGERY SHOWING RESPECTABLE SHORT WAVE RUNNING
ACROSS THE UPPER PENINSULA THIS MORNING...AND ASSOCIATED MID LEVEL
DRY PUNCH EXTRAPOLATED TO PASS THROUGH THE CWA THROUGH 16Z OR SO.
SCT LIGHT RAIN SHOWERS ASSOCIATED WITH THE WAVE NOW PASSING ACROSS
THE NRN THIRD OF THE CWA. MEANWHILE...DEEP LOW LEVEL MOISTURE
EXTENDS UP THROUGH LOWER MICHIGAN TO AROUND THE TIP OF THE MITT
COUNTIES. EARLIER SHOWER ACTIVITY HAS EXITED...BUT QUITE A BIT OF
FOG ACROSS NRN LOWER MICHIGAN AND EVEN SOME DRIZZLE SHOWING UP
ACROSS THE HIGHER TERRAIN ON KAPX RADAR. ALSO OF NOTE...MCS ACTIVITY
ONGOING ACROSS THE MIDWEST ALONG STATIONARY FRONT BUT EXPECTED TO
REMAIN WELL SOUTH OF THE REGION TODAY.
FORECAST CONCERNS FOR THE AFTERNOON OBVIOUSLY REVOLVE AROUND
ANTICIPATED CLEARING TREND. AS MENTIONED ABOVE...MID LEVEL DRY SLOT
EXTRAPOLATED TO PASS THROUGH THE CWA THROUGH 16Z...AT WHICH POINT
SHOWER ACTIVITY ACROSS THE NRN THIRD OF THE CWA WILL END...AND WE
SHOULD BEGIN TO SEE W-E IMPROVEMENT ACROSS NRN LOWER MICHIGAN AS
DAYTIME HEATING/MIXING GOES TO WORK ON REMAINING THINNER LOW LEVEL
MOISTURE. AM CONCERNED THE CLEARING PROCESS MAY TAKE AWHILE TO
UNFOLD (AS OFTEN TIMES HAPPENS) PARTICULARLY ACROSS NORTHEAST LOWER
MICHIGAN AND MAY KEEP THINGS ON THE MOSTLY CLOUDY SIDE THERE THROUGH
MID AFTERNOON WITH THE MORNING UPDATE.
OTHERWISE...DEPENDING ON THE SPEED AND DEGREE OF CLEARING...
TEMPERATURES COULD TOUCH 60 IN SOME SPOTS IN NRN LOWER BUT STRUGGLE
TO GET OUT OF THE 40S IN OTHERS (NORTHEAST LOWER) IF CLEARING IS
SLOW. PLAN IS TO TWEAK TEMPS DOWN JUST A LITTLE FROM THE CURRENT
FORECAST ACROSS NE LOWER MICHIGAN WITH THE IDEA OF A SLOWER CLEARING
TREND. HOWEVER...THIS WILL OBVIOUSLY BE THE WRONG DIRECTION IF CLOUD
COVER DOES MIX AND CLEAR OUT FASTER.
ADAM
&&
.AVIATION...ISSUED AT 746 AM.
UPPER LEVEL SHORTWAVE WILL SWEEP ACROSS NORTHERN MICHIGAN LATER THIS
MORNING. BUILDING HIGH PRESSURE AND STRONG DRYING BEHIND DEPARTING
SYSTEM WILL HELP SCOUR OUT LOW LEVEL MOISTURE AND ASSOCIATED
VFR-MVFR CLOUD DECK AND VISIBILITIES BY THIS AFTERNOON. CEILINGS/VIS
EXPECTED TO REMAIN UNOBSTRUCTED LATER THIS AFTERNOON THROUGH THE
OVERNIGHT AS HIGH PRESSURE REMAINS IN CONTROL. WINDS EXPECTED TO
REMAIN UNDER 10 KNOTS ALL TAF SITES THROUGH THIS TAF CYCLE.
MSB
&&
.DISCUSSION...ISSUED AT 347 AM.
WESTERN GREAT LAKES BENEATH CONFLUENCE ZONE WHERE UPSTREAM SPLIT
FLOW MERGING BACK TOGETHER. NORTHERN BRANCH WAVE ALONG U.S./CANADIAN
BORDER WILL SWING THROUGH THE STATE TODAY...WHILE SOUTHERN BRANCH
UPPER LOW OVER NORTHERN MEXICO BEGINS TO LIFT OUT THROUGH THE PLAINS
STATES AND WILL EVENTUALLY HAVE AN IMPACT ON NORTHERN MI WEATHER
DURING THE LATTER PORTION OF THE WEEKEND AND INTO EARLY NEXT WEEK.
IN GENERAL HOWEVER A RATHER MILD PERIOD SHAPING UP OVER THE NEXT
WEEK. MAIN FORECAST CONCERNS WILL DEAL WITH NUISANCE PRECIPITATION
AND CLOUD COVER ISSUES TODAY...THEN EVOLUTION OF RAIN CHANCES FOR
LATER SUNDAY AND BEYOND AS REMNANTS OF SOUTHERN BRANCH WAVE GET INTO
THE ACT.
TODAY/TONIGHT...COUPLE OF FEATURES OF NOTE TO START OUT THE
FORECAST THIS MORNING. LOW/MID CLOUD HAS BEEN ADVANCING NORTHWARD
ACROSS THE LOWER PENINSULA IN AN AREA OF LOW/MID LEVEL WARM
ADVECTION NORTH OF STATIONARY FRONTAL BOUNDARY WHICH LIES ACROSS
IA/IL/SOUTHERN OH. VARIOUS AIRCRAFT SOUNDINGS ACROSS SOUTHERN
LOWER/WI INDICATE MOISTURE LAYER EXTENDS TO ABOUT 600MB...A FAIR
AMOUNT DEEPER THAN EXPECTED WHICH HAS BEEN ENOUGH TO ALLOW FOR
SCATTERED SHOWERS TO DEVELOP GENERALLY SOUTH OF M-72. TO THE
NORTHWEST...WATER VAPOR IMAGERY SHOWS A SHORT WAVE TROUGH ALONG
THE MN/ONTARIO BORDER. GOOD DEAL OF MID/HIGH CLOUD WITH THIS
FEATURE ADVANCING ACROSS FAR NORTHERN WI/WESTERN UPPER...SOME
RADAR RETURNS WITH THIS BUT LITTLE REACHING THE GROUND AS LOWER
LAYERS QUITE A BIT DRIER IN 00Z INL/MPX SOUNDINGS. DEALING WITH
THE LOWER PENINSULA SHOWER ACTIVITY FIRST...LOOKS LIKE THIS WILL
MAINLY BE AN EARLY MORNING ISSUE...IR/RADAR TRENDS SUGGEST THAT BY
PRESS TIME SHOULD BE ABLE TO CONFINE EARLY POPS EAST OF US-131/SOUTH
OF M-68. ANTICIPATE SHOWER ACTIVITY TO BE EAST OF THE FORECAST
AREA BY 15Z. AS FOR THE NORTHERN STREAM SHORT WAVE...CURRENT
FORECAST HAS SOME MORNING RAIN CHANCES ACROSS EASTERN UPPER AND
THE STRAITS...AND SEE NO REASON NOT TO KEEP THIS GOING. NOT MUCH
GOING ON UPSTREAM AS FAR AS SURFACE REPORTS OF PRECIPITATION ARE
CONCERNED THOUGH LOW LEVELS AS MENTIONED EARLIER ARE QUITE A BIT
DRIER. IR/FOG IMAGERY SHOWS LOW LEVEL MOISTURE SURGING NORTH
ACROSS NORTHERN LAKE MICHIGAN AND TOWARD EASTERN UPPER...AND THIS
SHOULD AID CHANCES OF SOME LIGHT PRECIP REACHING THE GROUND LATER
THIS MORNING AS THE UPPER DYNAMICS ROLL THROUGH. PRECIP CHANCES
SHOULD END ACROSS EASTERN UPPER BY EARLY AFTERNOON AS SHORT WAVE
PASSES BY AND DRIER AIR SWEEPS IN FROM THE WEST. SO ANTICIPATE
DECREASING CLOUDINESS AS THE AFTERNOON WEARS ON ACROSS THE ENTIRE
AREA. SOME LAKE BREEZE COMPONENT TO THE WIND FIELDS EXPECTED THIS
AFTERNOON...ESPECIALLY ALONG THE LAKE HURON SHORELINE NORTH OF APN
AND AROUND THE EASTERN END OF THE UPPER PENINSULA. QUIET NIGHT
LOOKS TO BE IN STORE FOR TONIGHT...PERHAPS A LITTLE PATCHY FOG
DEVELOPING BEFORE WINDS PICK UP AFTER MIDNIGHT...AND EXPECTING AN
INCREASE IN HIGH CLOUDS OVERNIGHT AS WELL.
AS FOR ONGOING HYDRO ISSUES...WILL DROP FLOOD WATCHES AT FORECAST
ISSUANCE TIME...AND LET ARENAC COUNTY FLOOD WARNING STAND ON ITS
OWN. SOUTH BRANCH TOBACCO/RIFLE RIVERS HAVE CRESTED AND ARE ON
THEIR WAY DOWN.
SUNDAY...FORECAST FOR SUNDAY CONTINUES TO OSCILLATE BACK AND FORTH
AS TO WHETHER OR NOT ANY PRECIPITATION IS GOING TO MAKE IT INTO
THE AREA DURING THE DAYTIME. GUIDANCE IS TRENDING BACK TOWARD
TRYING TO PUSH AT LEAST SOME REMNANT WARM ADVECTION PRECIP ACROSS
THE STATE FROM THE SOUTH SUNDAY...MAIN MODEL DISCREPANCY APPEARS
TO BE IN TIMING OF BETTER LOW LEVEL MOISTURE RETURN (GFS/UKMET
QUICKER...NAM SLOWER). CURRENT FORECAST HAS AFTERNOON RAIN CHANCES
ACROSS FAR SOUTHWEST PORTION OF THE FORECAST AREA AND THIS STILL
LOOKS FINE...WILL ACKNOWLEDGE GUIDANCE TREND AND EXPAND PRECIP
CHANCES A LITTLE FARTHER INLAND DURING THE AFTERNOON...KEEPING
MAINLY NORTHEAST LOWER DRY UNTIL SUNDAY EVENING. MAIN AREA OF
CONVECTION WILL BE DEVELOPING ALONG FRONTAL BOUNDARY AND AHEAD OF
SHORT WAVE TROUGH ACROSS MN/WI/IA/IL...WHICH WILL ALL LIFT EAST/
NORTHEAST AND SPREAD ACROSS THE FORECAST AREA AFTER MIDNIGHT ALONG
NOSE OF 40+KT LOW LEVEL JET.
MONDAY THROUGH WEDNESDAY...SHORT WAVE ENERGY AND ASSOCIATED
CONVECTION WILL ROLL THROUGH NORTHERN MI MONDAY MORNING...STILL
LOOKS LIKE IT MAY DRY OUT DURING THE AFTERNOON. MONDAY NIGHT
LOOKING A LITTLE MORE INTERESTING FROM THE STANDPOINT THAT IT MAY
END UP BEING CLOUDY BUT DRY AS SURFACE BOUNDARY PRESSES IN FROM
THE NORTH. NO REAL INSTABILITY APPEARS TO BE IN THE CARDS THOUGH
SIGNS OF SOME TRAPPED LOW LEVEL MOISTURE COULD END UP WITH SOME
FOG/DRIZZLE MORE THAN ANYTHING ELSE. HOW FAR SOUTH THE BOUNDARY
GETS WILL THEN IMPACT POTENTIAL RAIN CHANCES FOR THE MIDWEEK
PERIOD AS LEE CYCLOGENESIS LOOKS TO GET RAMPED UP BY WEDNESDAY...
THE END RESULT MAY BE ANOTHER SURGE OF WARM ADVECTION PRECIP INTO
THE STATE LATER TUESDAY INTO WEDNESDAY THOUGH INITIAL SURGE OF
RAIN MAY BE BLUNTED BY DRY EASTERLY FLOW AROUND HUDSON BAY SURFACE
HIGH. A LOT OF UNCERTAINTY REGARDING THIS HOWEVER...WHICH ARGUES
FOR FEW CHANGES TO GOING FORECAST AND THAT SEEMS TO BE THE
CONSENSUS. WILL GO DRY ACROSS EASTERN UPPER FOR TUESDAY...WITH LOW
CHANCE POPS ACROSS NORTHERN LOWER. WILL KEEP WEDNESDAY DRY FOR
NOW...IT MAY TURN OUT THAT THE TUESDAY/WEDNESDAY FORECASTS WILL
NEED TO BE SWAPPED (DRY TUESDAY/RAIN WEDNESDAY).
&&
.APX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
JPB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
925 AM EDT SAT MAR 24 2007
.UPDATE...
LIGHT WIND FIELDS HAVE PROMOTED DEVELOPMENT OF AREAS OF DENSE FOG
OVR SCNTRL UPR MI LAST NIGHT INTO EARLY THIS MORNING. 10Z TAMDAR
FM KSAW INDICATED MOIST PROFILE TO NEAR 900MB WHILE YQT TAMDAR
SHOWED DRIER CONDITIONS WITH MOISTURE EXTENDING TO ONLY 975MB. DRY
AIR WILL SPILL IN AFTER SHORTWAVE OVR NORTH LAKE SUPERIOR PASSES
THROUGH THIS MORNING. WEAK PRES RISE OVR NW WI WILL ALSO EDGE EAST
AND SHOULD BEGIN TO SCOUR OUT THE FOG SO DID NOT ISSUE AN ADVY. DID
UPDATE GRIDS TO EMPHASIZE FOG MORE. SECOND BATCH OF SHOWERS ALONG
SHORTWAVE TROUGH DID PRODUCE SOME RAIN AT KCMX. TIMING THE BACK EDGE
OF ENHANCED CLOUDS/RADAR ECHOES HAS THE SHOWERS OUT OF CWA AFTER
16Z. BASED ON MIXING TO H85 ON LATEST RUC SOUNDINGS MAY NEED TO
RAISE TEMPS FM CURRENT MAX TEMPS IN GRIDS...ALTHOUGH DEVELOPING LAKE
BREEZES WILL EVENTUALLY COOL THE SHORE LINES.
&&
.PREV DISCUSSION (545 AM EDT)...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW NEARLY ZONAL FLOW ACROSS
THE NRN CONUS/SRN CANADA. IN THIS FAST FLOW...SHORTWAVE OF INTEREST
IN THE SHORT TERM IS OVER SRN SASKATCHEWAN/ERN MT/WRN ND. RADARS
SHOW DECENT COVERAGE OF ECHOES ACROSS ND/SRN MANITOBA ASSOCIATED
WITH THIS SHORTWAVE...AND THERE HAVE BEEN A FEW OBS THAT HAVE
INDICATED -SHRA IN NRN ND/SE SASKATCHEWAN/SRN MANITOBA TODAY. WELL
TO THE W... SHORTWAVE THAT DROPPED OUT OF THE WESTERLIES 2-3 DAYS
AGO OVER THE W COAST AND BECAME A MID LEVEL LOW IS NOW CENTERED JUST
S OF AZ. THIS SYSTEM WILL BE OF INTEREST TO FCST HERE LATE IN THE
UPCOMING WEEKEND AS IT GETS KICKED NE BY NEXT TROF APPROACHING THE W
COAST.
TODAY...WILL KEEP A SLIGHT CHC OF RAIN IN THIS MORNING FOR THE NRN
TIER OF THE FCST AREA AS THE SHORTWAVE FROM NRN MN MOVES ACROSS THE
FCST AREA. OTHERWISE...MODELS SHOW GOOD DRYING/SUBSIDENCE WITH
MID-LVL RDGG IN THE WAKE OF SHORTWAVE SO WOULD EXPECT SKIES TO CLEAR
FROM W TO E IN THE AFTERNOON. WITH WEAK SFC HIGH PRES OVER THE
AREA...EXPECT LAKE BREEZE FORMATION THIS AFTERNOON NEAR LAKE
SUPERIOR AND LAKE MICHIGAN TO KEEP TEMPS COOLER THERE. MIXING TO
AROUND 850 MB ON FCST SOUNDINGS SHOULD YIELD HIGHS IN THE UPPER 50S
TO LOWER 60S OVER THE WRN INTERIOR.
TONIGHT...SFC RDG AND ASSOC VERY DRY AIRMASS IN PLACE OVER THE
AREA(PWAT AOB 0.25 INCH) AND LIGHT WINDS SHOULD ALLOW FOR FAVORABLE
RADIATIONAL COOLING CONDITIONS INTO THE EARLY OVERNIGHT AS TEMPS
DROP INTO THE LOWER 30S PER MOS GUIDANCE. LOOK FOR INCREASING CLOUDS
AFTER 06Z HOWEVER AS WINDS BECOME SE ON BACKSIDE OF RDG. HIGHER
DWPNTS INTO THE LOW TO MID 30S ADVECTING OVER LAKE MICHIGAN IN A SE
FLOW COULD RESULT IN PATCHY FOG FOR CENTRAL AND ERN COUNTIES AFTER
MIDNIGHT. SE DOWNSLOPE WINDS LATE FOR FAR WEST COULD BRING TEMPS UP
SOME BEFORE SUNRISE.
SUN INTO SUN NIGHT...MDLS ARE IN GENERAL AGREEMENT LIFTING A
SHRTWV...REMNANTS OF A CLOSED LOW OVER THE SW U.S...INTO THE WRN
GREAT LAKES. THE 00Z UKMET IS STILL SLOWER WITH THE SYSTEM THAN THE
GFS/CANADIAN AND NAM. GENERALLY FOLLOWED CONSENSUS OF GFS/NAM AND
CANADIAN FOR DETAILS. INITIAL SHRA/TSRA COULD DEVELOP BY SUN MORNING
OVER WI BDR COUNTIES WITH STRONG WAA AT NOSE OF 30-40 KT 850 MB JET
AND PWAT VALUES INCREASING TO GREATER THAN AN INCH. 850 MB THETA-E
RDG ALSO MOVES IN FROM THE W ALONG WITH DECREASING 850-500 MB
THETA-E LAPSE RATES AND UPR DIFLUENCE AHEAD OF SHORTWAVE TROF. SCT
STORMS FORMING IN THE SW FCST AREA IN THE MORNING WILL SPREAD NE
ACROSS THE CWFA IN THE AFTERNOON. DEEP Q-VECT CONVERGENCE JUST AHEAD
OF THE SHORTWAVE SPREADS ACROSS THE FCST AREA SUN NIGHT SUPPORTING
LIKELY POPS ACROSS THE CWFA. ELEVATED CAPE VALUES OF 500-1000 J/KG
OFF MODEL SNDGS ALONG WITH DEEP LYR SHEAR IN EXCESS OF 35 KT AND SRH
APPROACHING 300 M2/S2 COULD SUPPORT SOME ELEVATED SUPERCELLS. SPC
DAY 2 CONVECTIVE OUTLOOK HAS MUCH OF THE WEST AND SCNTRL FCST AREA
IN A SLIGHT RISK FOR SVR STORMS. WET-BULB ZERO HEIGHTS IN 7-8 KFT
RANGE WOULD ARGUE FOR LARGE HAIL AS THE BIGGEST THREAT ESPECIALLY
AS LOW-LEVELS BECOME MORE STABLE BY LATE AFT AND EVENING. BRIEF HEAVY
DOWNPOURS WILL BE LIKELY AS WELL BUT SINCE SYSTEM SHOULD BE FAIRLY
PROGRESSIVE WOULD NOT EXPECT PCPN AMOUNTS MUCH MORE THAN HALF AN
INCH.
MON...EXPECT SHRA/TSRA TO END OVER THE WEST EARLY AND E BY AFTERNOON
AS THE SHORTWAVE DEPARTS E AND RDGING/QVECTOR DIV BUILD IN BEHIND
IT. EXPECTED SUNSHINE WITH WRLY FLOW AND 900 MB TEMPS FCST NEAR 10C
SHOULD ALLOW TEMPS TO CLIMB TO LOWER 60S ESPECIALLY OVER WRN FCST
AREA. LINGERING SFC TROF...POSSIBLE CLOUDS AND NW FLOW EXPECTED
BEHIND THE TROF COULD KEEP ERN COUNTIES IN THE LOWER 50S.
MON NIGHT INTO TUE...EXPECT DRY CONDITIONS AS MID-LVL RIDGE STAYS
POSITIONED OVER THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...JLA
PREV DISCUSSION...VOSS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
746 AM EDT SAT MAR 24 2007
.AVIATION...UPPER LEVEL SHORTWAVE WILL SWEEP ACROSS NORTHERN
MICHIGAN LATER THIS MORNING. BUILDING HIGH PRESSURE AND STRONG
DRYING BEHIND DEPARTING SYSTEM WILL HELP SCOUR OUT LOW LEVEL
MOISTURE AND ASSOCIATED VFR-MVFR CLOUD DECK AND VISIBILITIES BY THIS
AFTERNOON. CEILINGS/VIS EXPECTED TO REMAIN UNOBSTRUCTED LATER THIS
AFTERNOON THROUGH THE OVERNIGHT AS HIGH PRESSURE REMAINS IN CONTROL.
WINDS EXPECTED TO REMAIN UNDER 10 KNOTS ALL TAF SITES THROUGH THIS
TAF CYCLE.
MSB
&&
.DISCUSSION...ISSUED AT 347 AM.
WESTERN GREAT LAKES BENEATH CONFLUENCE ZONE WHERE UPSTREAM SPLIT
FLOW MERGING BACK TOGETHER. NORTHERN BRANCH WAVE ALONG U.S./CANADIAN
BORDER WILL SWING THROUGH THE STATE TODAY...WHILE SOUTHERN BRANCH
UPPER LOW OVER NORTHERN MEXICO BEGINS TO LIFT OUT THROUGH THE PLAINS
STATES AND WILL EVENTUALLY HAVE AN IMPACT ON NORTHERN MI WEATHER
DURING THE LATTER PORTION OF THE WEEKEND AND INTO EARLY NEXT WEEK.
IN GENERAL HOWEVER A RATHER MILD PERIOD SHAPING UP OVER THE NEXT
WEEK. MAIN FORECAST CONCERNS WILL DEAL WITH NUISANCE PRECIPITATION
AND CLOUD COVER ISSUES TODAY...THEN EVOLUTION OF RAIN CHANCES FOR
LATER SUNDAY AND BEYOND AS REMNANTS OF SOUTHERN BRANCH WAVE GET INTO
THE ACT.
TODAY/TONIGHT...COUPLE OF FEATURES OF NOTE TO START OUT THE
FORECAST THIS MORNING. LOW/MID CLOUD HAS BEEN ADVANCING NORTHWARD
ACROSS THE LOWER PENINSULA IN AN AREA OF LOW/MID LEVEL WARM
ADVECTION NORTH OF STATIONARY FRONTAL BOUNDARY WHICH LIES ACROSS
IA/IL/SOUTHERN OH. VARIOUS AIRCRAFT SOUNDINGS ACROSS SOUTHERN
LOWER/WI INDICATE MOISTURE LAYER EXTENDS TO ABOUT 600MB...A FAIR
AMOUNT DEEPER THAN EXPECTED WHICH HAS BEEN ENOUGH TO ALLOW FOR
SCATTERED SHOWERS TO DEVELOP GENERALLY SOUTH OF M-72. TO THE
NORTHWEST...WATER VAPOR IMAGERY SHOWS A SHORT WAVE TROUGH ALONG
THE MN/ONTARIO BORDER. GOOD DEAL OF MID/HIGH CLOUD WITH THIS
FEATURE ADVANCING ACROSS FAR NORTHERN WI/WESTERN UPPER...SOME
RADAR RETURNS WITH THIS BUT LITTLE REACHING THE GROUND AS LOWER
LAYERS QUITE A BIT DRIER IN 00Z INL/MPX SOUNDINGS. DEALING WITH
THE LOWER PENINSULA SHOWER ACTIVITY FIRST...LOOKS LIKE THIS WILL
MAINLY BE AN EARLY MORNING ISSUE...IR/RADAR TRENDS SUGGEST THAT BY
PRESS TIME SHOULD BE ABLE TO CONFINE EARLY POPS EAST OF US-131/SOUTH
OF M-68. ANTICIPATE SHOWER ACTIVITY TO BE EAST OF THE FORECAST
AREA BY 15Z. AS FOR THE NORTHERN STREAM SHORT WAVE...CURRENT
FORECAST HAS SOME MORNING RAIN CHANCES ACROSS EASTERN UPPER AND
THE STRAITS...AND SEE NO REASON NOT TO KEEP THIS GOING. NOT MUCH
GOING ON UPSTREAM AS FAR AS SURFACE REPORTS OF PRECIPITATION ARE
CONCERNED THOUGH LOW LEVELS AS MENTIONED EARLIER ARE QUITE A BIT
DRIER. IR/FOG IMAGERY SHOWS LOW LEVEL MOISTURE SURGING NORTH
ACROSS NORTHERN LAKE MICHIGAN AND TOWARD EASTERN UPPER...AND THIS
SHOULD AID CHANCES OF SOME LIGHT PRECIP REACHING THE GROUND LATER
THIS MORNING AS THE UPPER DYNAMICS ROLL THROUGH. PRECIP CHANCES
SHOULD END ACROSS EASTERN UPPER BY EARLY AFTERNOON AS SHORT WAVE
PASSES BY AND DRIER AIR SWEEPS IN FROM THE WEST. SO ANTICIPATE
DECREASING CLOUDINESS AS THE AFTERNOON WEARS ON ACROSS THE ENTIRE
AREA. SOME LAKE BREEZE COMPONENT TO THE WIND FIELDS EXPECTED THIS
AFTERNOON...ESPECIALLY ALONG THE LAKE HURON SHORELINE NORTH OF APN
AND AROUND THE EASTERN END OF THE UPPER PENINSULA. QUIET NIGHT
LOOKS TO BE IN STORE FOR TONIGHT...PERHAPS A LITTLE PATCHY FOG
DEVELOPING BEFORE WINDS PICK UP AFTER MIDNIGHT...AND EXPECTING AN
INCREASE IN HIGH CLOUDS OVERNIGHT AS WELL.
AS FOR ONGOING HYDRO ISSUES...WILL DROP FLOOD WATCHES AT FORECAST
ISSUANCE TIME...AND LET ARENAC COUNTY FLOOD WARNING STAND ON ITS
OWN. SOUTH BRANCH TOBACCO/RIFLE RIVERS HAVE CRESTED AND ARE ON
THEIR WAY DOWN.
SUNDAY...FORECAST FOR SUNDAY CONTINUES TO OSCILLATE BACK AND FORTH
AS TO WHETHER OR NOT ANY PRECIPITATION IS GOING TO MAKE IT INTO
THE AREA DURING THE DAYTIME. GUIDANCE IS TRENDING BACK TOWARD
TRYING TO PUSH AT LEAST SOME REMNANT WARM ADVECTION PRECIP ACROSS
THE STATE FROM THE SOUTH SUNDAY...MAIN MODEL DISCREPANCY APPEARS
TO BE IN TIMING OF BETTER LOW LEVEL MOISTURE RETURN (GFS/UKMET
QUICKER...NAM SLOWER). CURRENT FORECAST HAS AFTERNOON RAIN CHANCES
ACROSS FAR SOUTHWEST PORTION OF THE FORECAST AREA AND THIS STILL
LOOKS FINE...WILL ACKNOWLEDGE GUIDANCE TREND AND EXPAND PRECIP
CHANCES A LITTLE FARTHER INLAND DURING THE AFTERNOON...KEEPING
MAINLY NORTHEAST LOWER DRY UNTIL SUNDAY EVENING. MAIN AREA OF
CONVECTION WILL BE DEVELOPING ALONG FRONTAL BOUNDARY AND AHEAD OF
SHORT WAVE TROUGH ACROSS MN/WI/IA/IL...WHICH WILL ALL LIFT EAST/
NORTHEAST AND SPREAD ACROSS THE FORECAST AREA AFTER MIDNIGHT ALONG
NOSE OF 40+KT LOW LEVEL JET.
MONDAY THROUGH WEDNESDAY...SHORT WAVE ENERGY AND ASSOCIATED
CONVECTION WILL ROLL THROUGH NORTHERN MI MONDAY MORNING...STILL
LOOKS LIKE IT MAY DRY OUT DURING THE AFTERNOON. MONDAY NIGHT
LOOKING A LITTLE MORE INTERESTING FROM THE STANDPOINT THAT IT MAY
END UP BEING CLOUDY BUT DRY AS SURFACE BOUNDARY PRESSES IN FROM
THE NORTH. NO REAL INSTABILITY APPEARS TO BE IN THE CARDS THOUGH
SIGNS OF SOME TRAPPED LOW LEVEL MOISTURE COULD END UP WITH SOME
FOG/DRIZZLE MORE THAN ANYTHING ELSE. HOW FAR SOUTH THE BOUNDARY
GETS WILL THEN IMPACT POTENTIAL RAIN CHANCES FOR THE MIDWEEK
PERIOD AS LEE CYCLOGENESIS LOOKS TO GET RAMPED UP BY WEDNESDAY...
THE END RESULT MAY BE ANOTHER SURGE OF WARM ADVECTION PRECIP INTO
THE STATE LATER TUESDAY INTO WEDNESDAY THOUGH INITIAL SURGE OF
RAIN MAY BE BLUNTED BY DRY EASTERLY FLOW AROUND HUDSON BAY SURFACE
HIGH. A LOT OF UNCERTAINTY REGARDING THIS HOWEVER...WHICH ARGUES
FOR FEW CHANGES TO GOING FORECAST AND THAT SEEMS TO BE THE
CONSENSUS. WILL GO DRY ACROSS EASTERN UPPER FOR TUESDAY...WITH LOW
CHANCE POPS ACROSS NORTHERN LOWER. WILL KEEP WEDNESDAY DRY FOR
NOW...IT MAY TURN OUT THAT THE TUESDAY/WEDNESDAY FORECASTS WILL
NEED TO BE SWAPPED (DRY TUESDAY/RAIN WEDNESDAY).
&&
.APX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
JPB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
347 AM EDT SAT MAR 24 2007
.DISCUSSION...WESTERN GREAT LAKES BENEATH CONFLUENCE ZONE WHERE
UPSTREAM SPLIT FLOW MERGING BACK TOGETHER. NORTHERN BRANCH WAVE
ALONG U.S./CANADIAN BORDER WILL SWING THROUGH THE STATE TODAY...
WHILE SOUTHERN BRANCH UPPER LOW OVER NORTHERN MEXICO BEGINS TO
LIFT OUT THROUGH THE PLAINS STATES AND WILL EVENTUALLY HAVE AN
IMPACT ON NORTHERN MI WEATHER DURING THE LATTER PORTION OF THE
WEEKEND AND INTO EARLY NEXT WEEK. IN GENERAL HOWEVER A RATHER MILD
PERIOD SHAPING UP OVER THE NEXT WEEK. MAIN FORECAST CONCERNS WILL
DEAL WITH NUISANCE PRECIPITATION AND CLOUD COVER ISSUES TODAY...
THEN EVOLUTION OF RAIN CHANCES FOR LATER SUNDAY AND BEYOND AS
REMNANTS OF SOUTHERN BRANCH WAVE GET INTO THE ACT.
TODAY/TONIGHT...COUPLE OF FEATURES OF NOTE TO START OUT THE
FORECAST THIS MORNING. LOW/MID CLOUD HAS BEEN ADVANCING NORTHWARD
ACROSS THE LOWER PENINSULA IN AN AREA OF LOW/MID LEVEL WARM
ADVECTION NORTH OF STATIONARY FRONTAL BOUNDARY WHICH LIES ACROSS
IA/IL/SOUTHERN OH. VARIOUS AIRCRAFT SOUNDINGS ACROSS SOUTHERN
LOWER/WI INDICATE MOISTURE LAYER EXTENDS TO ABOUT 600MB...A FAIR
AMOUNT DEEPER THAN EXPECTED WHICH HAS BEEN ENOUGH TO ALLOW FOR
SCATTERED SHOWERS TO DEVELOP GENERALLY SOUTH OF M-72. TO THE
NORTHWEST...WATER VAPOR IMAGERY SHOWS A SHORT WAVE TROUGH ALONG
THE MN/ONTARIO BORDER. GOOD DEAL OF MID/HIGH CLOUD WITH THIS
FEATURE ADVANCING ACROSS FAR NORTHERN WI/WESTERN UPPER...SOME
RADAR RETURNS WITH THIS BUT LITTLE REACHING THE GROUND AS LOWER
LAYERS QUITE A BIT DRIER IN 00Z INL/MPX SOUNDINGS. DEALING WITH
THE LOWER PENINSULA SHOWER ACTIVITY FIRST...LOOKS LIKE THIS WILL
MAINLY BE AN EARLY MORNING ISSUE...IR/RADAR TRENDS SUGGEST THAT BY
PRESS TIME SHOULD BE ABLE TO CONFINE EARLY POPS EAST OF US-131/SOUTH
OF M-68. ANTICIPATE SHOWER ACTIVITY TO BE EAST OF THE FORECAST
AREA BY 15Z. AS FOR THE NORTHERN STREAM SHORT WAVE...CURRENT
FORECAST HAS SOME MORNING RAIN CHANCES ACROSS EASTERN UPPER AND
THE STRAITS...AND SEE NO REASON NOT TO KEEP THIS GOING. NOT MUCH
GOING ON UPSTREAM AS FAR AS SURFACE REPORTS OF PRECIPITATION ARE
CONCERNED THOUGH LOW LEVELS AS MENTIONED EARLIER ARE QUITE A BIT
DRIER. IR/FOG IMAGERY SHOWS LOW LEVEL MOISTURE SURGING NORTH
ACROSS NORTHERN LAKE MICHIGAN AND TOWARD EASTERN UPPER...AND THIS
SHOULD AID CHANCES OF SOME LIGHT PRECIP REACHING THE GROUND LATER
THIS MORNING AS THE UPPER DYNAMICS ROLL THROUGH. PRECIP CHANCES
SHOULD END ACROSS EASTERN UPPER BY EARLY AFTERNOON AS SHORT WAVE
PASSES BY AND DRIER AIR SWEEPS IN FROM THE WEST. SO ANTICIPATE
DECREASING CLOUDINESS AS THE AFTERNOON WEARS ON ACROSS THE ENTIRE
AREA. SOME LAKE BREEZE COMPONENT TO THE WIND FIELDS EXPECTED THIS
AFTERNOON...ESPECIALLY ALONG THE LAKE HURON SHORELINE NORTH OF APN
AND AROUND THE EASTERN END OF THE UPPER PENINSULA. QUIET NIGHT
LOOKS TO BE IN STORE FOR TONIGHT...PERHAPS A LITTLE PATCHY FOG
DEVELOPING BEFORE WINDS PICK UP AFTER MIDNIGHT...AND EXPECTING AN
INCREASE IN HIGH CLOUDS OVERNIGHT AS WELL.
AS FOR ONGOING HYDRO ISSUES...WILL DROP FLOOD WATCHES AT FORECAST
ISSUANCE TIME...AND LET ARENAC COUNTY FLOOD WARNING STAND ON ITS
OWN. SOUTH BRANCH TOBACCO/RIFLE RIVERS HAVE CRESTED AND ARE ON
THEIR WAY DOWN.
SUNDAY...FORECAST FOR SUNDAY CONTINUES TO OSCILLATE BACK AND FORTH
AS TO WHETHER OR NOT ANY PRECIPITATION IS GOING TO MAKE IT INTO
THE AREA DURING THE DAYTIME. GUIDANCE IS TRENDING BACK TOWARD
TRYING TO PUSH AT LEAST SOME REMNANT WARM ADVECTION PRECIP ACROSS
THE STATE FROM THE SOUTH SUNDAY...MAIN MODEL DISCREPANCY APPEARS
TO BE IN TIMING OF BETTER LOW LEVEL MOISTURE RETURN (GFS/UKMET
QUICKER...NAM SLOWER). CURRENT FORECAST HAS AFTERNOON RAIN CHANCES
ACROSS FAR SOUTHWEST PORTION OF THE FORECAST AREA AND THIS STILL
LOOKS FINE...WILL ACKNOWLEDGE GUIDANCE TREND AND EXPAND PRECIP
CHANCES A LITTLE FARTHER INLAND DURING THE AFTERNOON...KEEPING
MAINLY NORTHEAST LOWER DRY UNTIL SUNDAY EVENING. MAIN AREA OF
CONVECTION WILL BE DEVELOPING ALONG FRONTAL BOUNDARY AND AHEAD OF
SHORT WAVE TROUGH ACROSS MN/WI/IA/IL...WHICH WILL ALL LIFT EAST/
NORTHEAST AND SPREAD ACROSS THE FORECAST AREA AFTER MIDNIGHT ALONG
NOSE OF 40+KT LOW LEVEL JET.
MONDAY THROUGH WEDNESDAY...SHORT WAVE ENERGY AND ASSOCIATED
CONVECTION WILL ROLL THROUGH NORTHERN MI MONDAY MORNING...STILL
LOOKS LIKE IT MAY DRY OUT DURING THE AFTERNOON. MONDAY NIGHT
LOOKING A LITTLE MORE INTERESTING FROM THE STANDPOINT THAT IT MAY
END UP BEING CLOUDY BUT DRY AS SURFACE BOUNDARY PRESSES IN FROM
THE NORTH. NO REAL INSTABILITY APPEARS TO BE IN THE CARDS THOUGH
SIGNS OF SOME TRAPPED LOW LEVEL MOISTURE COULD END UP WITH SOME
FOG/DRIZZLE MORE THAN ANYTHING ELSE. HOW FAR SOUTH THE BOUNDARY
GETS WILL THEN IMPACT POTENTIAL RAIN CHANCES FOR THE MIDWEEK
PERIOD AS LEE CYCLOGENESIS LOOKS TO GET RAMPED UP BY WEDNESDAY...
THE END RESULT MAY BE ANOTHER SURGE OF WARM ADVECTION PRECIP INTO
THE STATE LATER TUESDAY INTO WEDNESDAY THOUGH INITIAL SURGE OF
RAIN MAY BE BLUNTED BY DRY EASTERLY FLOW AROUND HUDSON BAY SURFACE
HIGH. A LOT OF UNCERTAINTY REGARDING THIS HOWEVER...WHICH ARGUES
FOR FEW CHANGES TO GOING FORECAST AND THAT SEEMS TO BE THE
CONSENSUS. WILL GO DRY ACROSS EASTERN UPPER FOR TUESDAY...WITH LOW
CHANCE POPS ACROSS NORTHERN LOWER. WILL KEEP WEDNESDAY DRY FOR
NOW...IT MAY TURN OUT THAT THE TUESDAY/WEDNESDAY FORECASTS WILL
NEED TO BE SWAPPED (DRY TUESDAY/RAIN WEDNESDAY).
&&
.APX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
JPB
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
934 AM CDT SAT MAR 24 2007
.UPDATE...A 12Z TAMDAR SOUNDINGS FROM TVF INDICATES THE FOG IS
ALMOST 2 KFT THICK THERE AND EVEN WITH A STRONG MARCH SUN IT WILL
TAKE AWHILE TO BURN OFF. IT PROBABLY MORE SHALLOW AROUND THE
FRINGES...NEAR GFK AND BJI BUT IS QUITE DENSE ATTM AND CERTAINLY
WORTHY OF EXTENDING THE ADVISORY. DEEP INTO THIS CLOUD DECK SUCH
AS ROX AND BDE STRATUS IS MORE COMMON SO TRANSITIONED THE FOG TO
AREAS THERE. BUT FOG HAS MOSTLY BURNED OFF WEST OF RED RIVER
VALLEY SO ALLOW THE FOG ADVISORY TO EXPIRE AS EXPECTED THERE.
ADVISORY WAS ISSUED FOR NORTH RED RIVER VALLEY AND NORTHWEST MN
UNTIL NOON. AHEAD OF THE ADVANCING FOG ON THE SOUTHERN EXTENT...
EXPECT THE SUN TO SLOW THE ADVANCE AND LIFT IT TO A STRATUS LAYER
BEFORE REACHING FAR...DTL AND PKD.
GIVEN THIS FOG AND STRATUS HAVE ADJUSTED THE TEMPERATURES TODAY A
BIT. THINK WARMING WILL HAPPEN QUICKLY ONCE IT DOES BURN OFF SO
DID NOT LOWER MAX READINGS BELOW THE 50S. WILL HAVE TO WATCH THE
STRATUS TO MAKE SURE IT DOES GO AWAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR NDZ008-016-027-030.
MN...DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR MNZ001-002-004>009-
013>017-022-023.
&&
$$
GV
AREA FORECAST DISCUSSION
NWS SEATTLE WA
925 AM PDT SAT MAR 24 2007
.SYNOPSIS...A STRONG FRONTAL SYSTEM WILL CONTINUE TO BRING RAIN
THROUGH THIS EVENING. A COOLER AIR MASS WILL MOVE INTO THE REGION
SUNDAY BEHIND THE FRONT. THE REGION SHOULD SEE DRY WEATHER FOR THE
FIRST PART OF THE WEEK...THEN WET AGAIN AFTER WEDNESDAY.
&&
.SHORT TERM...VIGOROUS FNTL SYSTEM TODAY WITH FROPA PGTSND ARND 06Z
THIS EVENING. AT H850 OFF THE MM5NAM WE SEE TEMPS AROUND +5C AT H850
TODAY AND WIND UP AROUND 50KTS SO THE PINEAPPLE EXPRESS CONTINUES.
THEN WITH FROPA THE 0C ISOTHERM IS INTO THE CASCADES AROUND 06Z WITH
TEMP AROUND -3C SUNDAY IN LIGHT WLY FLOW. OBVIOUSLY ANOTHER 12-15
HOURS OF RAIN IN THE MOUNTAINS...THEN AS THE PRECIP TAPERS OFF THE
SNOW LEVEL DROPS DOWN TO AROUND PASS LEVEL AROUND MIDNIGHT TONIGHT.
WINDY IN SOME AREAS TODAY...THE WIND AT KPAE HAS BEEN AROUND 30MPH.
HOWEVER THE 8 AND 9AM OBS FROM WILSON AND SMITH ISLAND ONLY SHOW
10KTS OR LESS DESPITE OUR GALE WARNING. FOR NOW...THE OLYMPICS SEEM
TO BE BLOCKING THE WINDS RATHER THAN ENHANCING THEM WITH A LEE SIDE
LOW. STRONGEST WINDS MAY END UP BEING ON THE EDMONDS KINGSTON RUN
TODAY. I HAVE NOT YET DECIDED WHAT TO DO WITH THE WIND ADVISORY
WHICH KICKS IN AT 10AM AND GOES TIL 7PM...PROBABLY WONT CHANGE IT
AND WINDS SHOULD INCREASE AGAIN WITH THIS NEXT PLUME OF 50KTS AT
H850 AND 40KTS AT 2000FT...PLUS SEE THE MARINE DISCUSSION BELOW FOR
THE EXPECTATION THAT WINDS WILL INCREASE RAPIDLY AGAIN BACK TO GALE
FORCE THOSE AREAS. MM
.LONG TERM...DRY MON TUE AND PERHAPS MOST OF THE DAY WED...AND RAIN
AT TIMES THU-SAT BASED ON THE OVERNITE GFS. IF THE 12Z GFS FOLLOWS
THE PREVIOUS RUNS WILL MAKE NEXT WEEKEND WET AND JUST BROADBRUSH
THU-SUN WITH RAIN. MM
&&
.AVIATION...ACARS SOUNDINGS REPORTING 850 MB WINDS SWLY AT 40 KNOTS
THIS MORNING. WSR-88D PRECIPITATION ECHOES SHOW THE RAIN SHADOW FROM
THE OLYMPICS PRETTY WELL FROM ABOUT KBFI-KPAE. BRIEF BREAK IN THE
HEAVIER PRECIPITATION THIS MORNING INTO THIS AFTERNOON,
PRECIPITATION RATES PICKING UP AGAIN LATER THIS AFTERNOON. FRONTAL
PASSAGE TIMED FOR THE COAST AROUND 03Z...KSEA 06Z. AHEAD OF THE
FRONT OUTSIDE THE RAIN SHADOWED AREAS IN THE INTERIOR CEILINGS
GENERALLY IN THE 1500 TO 2500 FOOT RANGE WITH ISOLATED VISIBILITIES
3-5SM WITH LIGHT RAIN. ALONG THE COAST CONDITIONS REMAINING LOW
UNTIL FRONTAL PASSAGE WITH CEILINGS AOB 1000 FEET AND VIS 1-3SM WITH
RAIN. CENTRAL SOUND CEILINGS ALL OVER THE PLACE FROM 500 TO 5000
FEET. EXPECT THE RAIN SHOW TO FILL IN THIS AFTERNOON WITH CEILINGS
SETTLING IN THE 1500 TO 2500 FOOT RANGE. LOCAL VISIBILITIES 3-5SM
WITH RAIN LATER THIS AFTERNOON UNTIL FRONTAL PASSAGE.
KSEA...CEILINGS BELOW 1000 FEET UNTIL 18Z...AFTER 18Z CEILINGS
GENERALLY 2000 TO 3000 FEET WITH VISIBILITIES LOWERING TO 5 SM AT
TIMES. WINDS SOUTHERLY 15 KNOTS GUSTING TO 25 KNOTS THROUGH THIS
EVENING.
&&
.MARINE...SOUTHERLY WINDS WILL INCREASE RAPIDLY BETWEEN 16Z AND
20Z AS A 990MB LOW MOVES INTO QUEEN CHARLOTTE SOUND AND AS STRONG
LOW LEVEL AND MID LEVEL WINDS ALOFT INTERACT WITH THE OLYMPIC
MOUNTAINS AND MOUNTAINS OF VANCOUVER ISLAND. FROM ABOUT 18Z UNTIL
FRONTAL PASSAGE BETWEEN 03Z AND 06Z FROM THE WEST...EXPECT GALE
FORCE WINDS AT AREAS PRONE TO SOUTH/SOUTHEAST WINDS SUCH AS THE
COAST...ENTRANCES TO THE STRAIT...ADMIRALTY INLET...AND NORTH INLAND
WATERS. WHILE GALES MAY SUBSIDE AT TIMES AS A MESOSCALE LOW NE OF
THE OLYMPICS WOBBLES AROUND...THEY SHOULD RAPIDLY REDEVELOP AS THE
LOW WOBBLES AGAIN. EXPECT WINDS TO GENERALLY REMAIN IN THE 20-30KT
RANGE IN PUGET SOUND AND HOOD CANAL. WINDS WILL VEER TO MORE
WESTERLY AND RELAX BEHIND THE FRONT. WINDS WILL SLOWLY SUBSIDE LATER
TONIGHT AS HIGH PRES BUILDS INTO THE AREA. FELTON
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
.GALE WARNING COAST...ENTRANCES TO THE STRAIT...ADMIRALTY
INLET...AND NORTHERN INLAND WATERS.
.SMALL CRAFT ADVISORY...PUGET SOUND AND HOOD CANAL...
CENTRAL STRAIT...GRAYS HARBOR FOR ROUGH BAR CONDITIONS.
.FLOOD WATCH FOR PORTIONS OF WRN WA.
$$
WEATHER.GOV/SEATTLE
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