Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 03/15/12
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
821 PM MDT WED MAR 14 2012
.UPDATE...
&&
.AVIATION...A WEAK MESOSCALE LOW HAS MOVED JUST EAST OF DIA WHICH
ALLOWED FOR WINDS TO SWITCH TO A MORE NNW DIRECTION BEHIND A
BNDRY. BOTH THE RUC AND HRRR SHOW THIS BNDRY DISAPPEARING WITHIN
THE NEXT HOUR OR TWO WITH THE WINDS BECOMING MORE SLY AFTER 04Z
AND STAYING THAT WAY THROUGH 12Z.
&&
.PREV DISCUSSION... /ISSUED 302 PM MDT WED MAR 14 2012/
SHORT TERM...DRY AIRMASS CONTINUES ACROSS REGION. WEAK PRESSURE
FALLS OVER PLAINS CURRENTLY CREATING SOUTH TO SOUTHEAST
WINDS...WITH SOME WIND GUSTS IN THE 25-30 MPH RANGE ACROSS
WASHINGTON COUNTY. CURRENT SURFACE OBSERVATIONS INDICATING THESE
GUSTS NOT THAT WIDESPREAD. LATEST MODELS SHOW WINDS TO BE
DECREASING ACROSS THE AREA BY THE EARLY EVENING AS THE AIR
STABILIZES AND PRESSURE FALLS DECREASE. OTHERWISE...SOUTHWEST FLOW
ALOFT TO PREVAIL THROUGH THURSDAY. CROSS SECTIONS SHOW SOME
INCREASE IN HIGH LEVEL MOISTURE OVERNIGHT...WITH POTENTIAL FOR
MORE WAVE CLOUD ALONG FOOTHILLS BY EARLY THURSDAY MORNING AS SHOWN
BY WRF SYNTHETIC SATELLITE IMAGERY PROGS. WILL ADD A BIT MORE
CLOUD TO THE SKY GRID ACROSS MOUNTAINS AS A RESULT. ON THURSDAY...
DRY AND WARM AIRMASS TO CONTINUE ACROSS AREA. SURFACE PROGS
INDICATE WINDS ACROSS PLAINS BECOMING SOUTHEAST AFTER 18Z...
SIMILAR TO WHAT`S OCCURRING THIS AFTERNOON. HOWEVER...7H WINDS ARE
EXPECTED TO BE LESS. SO DESPITE THE DECENT MIXING EXPECTED...
SURFACE WINDS SHOULD NOT BE AS GUSTY. ALTHOUGH AFTERNOON HUMIDITY
WILL BE LOW...WINDS TO BE BELOW CRITICAL FIRE WEATHER THRESHOLDS.
ELSEWHERE...SOUTHWEST TO WEST WINDS TO PREVAIL THROUGH THE DAY...
THOUGH SPEEDS NOT EXPECTED TO EXCEED CRITICAL FIRE WEATHER
CRITERIA DESPITE LOW HUMIDITY. AS FOR TEMPERATURES...THICKNESS
PROGS AS WELL AS GUIDANCE SHOW LITTLE CHANGE FROM TODAY`S
READINGS. THIS EQUATES TO 70S ACROSS THE PLAINS...40S AND 50S
MOUNTAINS. RECORD HIGH FOR DENVER ON THURSDAY IS 75 DEGREES SET
WAY BACK IN 1877. HIGHS LOOK TO BE A FEW DEGREES SHY.
LONG TERM...SOUTHWEST FLOW ALOFT CONTINUES TO BE PROGGED OVER
NORTHEASTERN COLORADO THROUGH THE END OF THE WEEK AS WE ARE IN
BETWEEN TROUGHING OVER THE WESTERN STATES AND RIDGING OVER THE
CENTRAL AND EASTERN STATES. THIS PATTERN WILL KEEP THE DRY AND
MUCH WARMER TEMPERATURES OVER THE FORECAST AREA THROUGH SATURDAY
AT LEAST. TEMPERATURES WILL CONTINUE TO BE 10 TO 20 DEGREES
WARMER THAN NORMAL OVER THE AREA.
THE UPPER TROUGH OVER THE WEST COAST WILL DIG SOUTH SATURDAY THEN
BEGIN TO MOVE INLAND SUNDAY. THIS IS WHERE MODELS CONTINUE TO
DIVERGE ON THEIR SOLUTIONS. THESE MODELS ARE NOT ONLY DIVERGING IN
FROM EACH OTHER...BUT ARE ALSO DIVERGING IN THEIR OWN RUN TO RUN
SOLUTIONS WITHIN EACH MODEL. SOME ARE DIGGING IT INTO A CUTOFF LOW
WHERE AS OTHERS KEEP IT AN OPEN TROUGH. EITHER WAY...ALL MODELS
ARE HAVING THE UPPER TROUGH/LOW FEATURE MOVE OVER THE STATE IN THE
MONDAY AND TUESDAY TIME FRAME.
FLOW ALOFT WILL BECOME SOUTHERLY SATURDAY INTO SUNDAY WITH
MOISTURE INCREASING. WILL LIKELY BEGIN TO SEE SOME ISOLATED SNOW
SHOWERS OVER THE MOUNTAINS LATE SATURDAY INTO SUNDAY...INCREASING
IN COVERAGE THROUGH THE FIRST HALF OF THE WEEK. TEMPERATURES WILL
STILL BE RELATIVELY WARM SO THE HIGH VALLEYS WILL LIKELY SEE RAIN
MIXING IN WITH THE SNOW...UNTIL MONDAY AND TUESDAY WITH THE SYSTEM
ALOFT AND SNOW LEVELS DROPPING AGAIN.
OVER THE PLAINS...SOUTHERLY SURFACE WINDS WILL BE INCREASING
SATURDAY AND SUNDAY AS LOW PRESSURE DEEPENS OVER THE NORTHERN
PLAINS AHEAD OF THE UPPER SYSTEM. WILL HAVE TO MONITOR THESE DAYS
FOR FIRE DANGER. HOWEVER A SLIGHT DECREASE IN TEMPERATURES EACH
DAY MAY HELP KEEP HUMIDITIES ABOVE CRITERIA. YET STILL THE EASTERN PLAINS
WILL LIKELY SEE GUSTS IN THE 30 TO 40 MPH RANGE ON THESE DAYS.
DEPENDING ON WHICH MODEL SOLUTION COMES TO FRUITION...WE MAY SEE
THESE STRONG SOUTHERLY WINDS AGAIN ON MONDAY...BUT TEMPERATURES
ARE EXPECTED TO COOL OFF ENOUGH TO TAKE LOW HUMIDITIES OUT OF THE
EQUATION. THERE IS A SLIGHT CHANCE OF SHOWERS MONDAY AS SYNOPTIC
LIFT AHEAD OF THE TROUGH WILL MOVE OVER THE STATE. AN ASSOCIATED
COLD FRONT IS EXPECTED TO DROP SOUTH OVER THE STATE SOMETIME
MONDAY NIGHT OR TUESDAY TO BRING EVEN COOLER TEMPERATURES AND A
MUCH BETTER CHANCE FOR PRECIPITATION. RIGHT NOW TEMPERATURES LOOK
TO STAY WARM ENOUGH FOR ONLY RAIN OR RAIN MIXED WITH SNOW TUESDAY.
AVIATION...WINDS TRYING TO SHIFT FROM THE SOUTH TO THE WEST
ACROSS AREA AIRPORTS AS WEAK WESTERLY WINDS MOVE OFF THE
FOOTHILLS. WILL MAINTAIN THE WEST TO NORTHWEST WIND FROM 23Z TO
03Z FOR NOW. OTHERWISE...SOUTHWEST WINDS TO PREVAIL OVERNIGHT AS
DRAINAGE PATTERN DEVELOPS. BY 18Z...WINDS TO SHIFT TO THE
SOUTHEAST WITH SPEEDS AROUND 8 KTS. VFR CONDITIONS TO PREVAIL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS ALBANY NY
148 AM EDT TUE MAR 13 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION OVERNIGHT...AND THEN PASS
THROUGH EASTERN NEW YORK AND WESTERN NEW ENGLAND TOMORROW AFTERNOON.
THEN A BRIEF HIGH PRESSURE RIDGE WILL BE FOLLOWED BY ANOTHER SYSTEM
AT THE END OF THE WORK WEEK. HIGH PRESSURE WILL BUILD AND DROP IN
FROM SOUTHERN QUEBEC NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 130 AM...A BATCH OF SHOWERS MOVED THROUGH THE REGION WITH VERY
LITTLE QPF. AS OF NOW...THE RADAR INDICATED ONLY ISOLATED COVERAGE
AT THE MOMENT. FOLLOWED THE HRRR WHICH INDICATED A SLIGHT INCREASE
IN COVERAGE TO OUR SOUTH IN THE NEXT FEW HOURS. RADARS DO INDICATE A
BIT MORE ACTIVITY UPSTREAM THE HUDSON VALLEY...ACROSS THE POCONOS OF
PA...BUT AGAIN VERY LIGHT.
PHENOMENALLY MILD TEMPERATURES CONTINUE WITH THE CLOUDS OVER AND A
BIT OF A SOUTHERLY BREEZE. MOST PLACES HAVE TEMPERATURES IN THE
50S...WITH USUAL SPOTS IN MID TO UPPER 40S. SEE NO WAY TEMPERATURES
WILL FALL ALL THAT MUCH MORE OVERNIGHT AS DEWPOINTS LOOK TO INCREASE
SOME AS A VERY WEAK WARM FRONT MOVES TOWARD US. RAISED EVERYONE
ABOUT 3 DEGREES. THESE OVERNIGHT LOWS RANGING FROM THE LOWER 50S TO
LOWER 40S ARE MORE REPRESENTATIVE OF MID MAY THAN MID MARCH.
THE AXIS OF DEEPEST MOISTURE SEEN ON WATER VAPOR SATELLITE IMAGERY
HAS NOW TRACKED TO OUR EAST.
VERY LITTLE IF ANY RAIN IN THE DRY SLOT ACROSS WESTERN NEW YORK.
HOWEVER...A SOLID LINE OF SHOWERS AND SOME THUNDERSTORMS STILL
EVIDENT ACROSS EXTREME SOUTHEAST MICHIGAN ABOUT TO MOVE INTO NEW
YORK STATE. THIS LINE IS AHEAD OF A COLD FRONT THIS LOOKS TO CROSS
OUR REGION LATER TODAY. MORE ABOUT THAT IN OUR SHORT TERM.
FOR THE REST OF THE OVERNIGHT...NOTHING MORE THAN A LIGHT SHOWER OR
TWO...MAINLY SOUTH AND NORTH OF ALBANY. OTHERWISE ENJOY MILD
CONDITIONS WITH LOWS ONLY DOWN TO THE LOWER 50S CAPITAL
DISTRICT...45-50 MOST OTHER PLACES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 130 AM...DECIDED TO GO AHEAD AND TWEAK POPS LATER TUESDAY. IT
IS NOW CLEARLY EVIDENT THAT WHATEVER LINE ASSOCIATED WITH THE COLD
FRONT WILL GO THOUGH A LITTLE FASTER THAN EARLIER THOUGHT. HAVE SPED
IT UP A BIT...PROBABLY NOT ENOUGH BUT AT LEAST THE RIGHT TREND. THIS
LINE LOOKS TO MOVE ACROSS OUR REGION STARTING MID MORNING IN
NORTHWESTERN ZONES...SWEEPING OUR SOUTHEASTERN ZONES BY LATE
AFTERNOON. BEST FORCING REMAINS NORTH BUT BEST INSTABILITY SOUTH.
DECIDED TO MENTION SLIGHT CHANCE OF THUNDER EVERYWHERE BUT WILL
REVISIT CONVECTION ISSUES LATER ON.
NO CHANGE TO TEMPERATURES FOR TUESDAY AND BEYOND FOR NOW. IN
FACT...NO CHANGE TO LATER FORECASTS EXCEPT TO MAKE TUESDAY NIGHT
MAINLY DRY NOW.
WENT WITH ADJMET FOR TEMPS.
NEAR RECORD TEMPERATURES ARE POSSIBLE ONCE AGAIN ON TUESDAY...
THOUGH LESS PROBABLE...WITH HIGHS MAINLY FROM THE 60S TO LOWER
70S. WARMER AIR WILL HAVE A TOUGHER TIME GETTING UP THROUGH THE
OBSTRUCTING HIGHER TERRAIN...AND THERE...HIGHS WILL BE IN MAINLY
THE 50S. LOWS TUESDAY NIGHT WILL BE IN MAINLY THE 30S AND 40S...
AND WEDNESDAY WILL BE NOTICEABLY COOLER BEHIND THE FRONT...WITH
HIGHS FROM AROUND 40 DEGREES IN THE ADIRONDACK HIGH PEAKS...TO THE
MID 60S IN THE LOWER MID HUDSON VALLEY.
WEDNESDAY NIGHT LOOKS TO BE THE DRY PART OF THE EXTENDED AS
MARITIME RIDGE CRESTS DOWN THE NORTHEAST COAST. LOWS WEDNESDAY
NIGHT WILL BE MOSTLY IN THE UPPER 20S AND THE 30S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
HE LONG TERM PERIOD WILL START WITH A SFC HIGH PRESSURE RIDGE
DRAPING SOUTHWEST OVER THE ST LAWRENCE RIVER VALLEY THROUGH LONG
ISLAND WILL PRODUCE DRY WARM WEATHER ON THURSDAY. SFC LOW PRESSURE
OVER THE CENTRAL GREAT LAKES REGION ON THURSDAY WILL MOVE EASTWARD
FRIDAY...TOWARD WESTERN NY. THIS SYSTEM WILL BRING A WARM FRONT
FOLLOWED BY A COLD FRONT THROUGH THE NORTHEAST FRIDAY AND FRIDAY
NIGHT. MODEL GUIDANCE DIFFERING ON ASSOCIATED UPPER LEVEL FEATURE
TO THIS SYSTEM. GFS SHOWING THE UPPER LEVEL TROUGH TRACKING FURTHER
NORTH...WHILE THE ECMWF BREAKS A PIECE OF ENERGY FROM THE MAIN
TROUGH. THE MAIN TROUGH DIGS DEEPER SOUTH ON THE ECMWF...PRODUCING A
LONGER PERIOD OF RAIN SHOWERS. WITH LACK OF CAPE AND JET
DYNAMICS...HAVE NOT INCLUDED ANY EMBEDDED CONVECTIVE ACTIVITY AT
THIS TIME.
SFC HIGH PRESSURE WILL BUILD INTO THE NORTHEAST FROM THE JAMES BAY
AREA LATE SATURDAY...BRINGING AN END TO CHC OF PRECIP THROUGH MONDAY.
ABOVE NORMAL TEMPS WILL TREND EVEN WARMER...ESPECIALLY FOR THE
WEEKEND INTO THE EARLY WORK WEEK. MAX TEMPS RUNNING ABOUT 10 DEGREES
ABOVE NORMAL AT THE END OF THE WORK WEEK...WILL HAVE REINFORCED WAA
FROM SOUTHERLY FLOW THURSDAY AND FRIDAY...WARMING 850HPA TEMPS TO
6C-8C. THE AFOREMENTIONED WEAK COLD FRONT WILL SHIFT WINDS OUT OF
THE NORTH...KEEPING TEMPS AROUND 10 DEGREES ABOVE NORMAL OVER THE
WEEKEND. WARMEST TEMPS EXPECTED ON MONDAY AS HIGH PRESSURE PROVIDES
SUNNY SKIES AND 850 HPA TEMPS INCREASED TO AROUND 10C. THIS WILL
RESULT IN SFC MAX TEMPS IN THE 60S-L70S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
WHILE MAINLY VFR CONDITIONS ARE EXPECTED...THE CHANCE FOR MVFR
THRESHOLDS BEING SATISFIED ARE AROUND 50 PERCENT.
LATEST RADAR IMAGERY REVEALS DISORGANIZED AREA OF SHOWERS MIGRATING
ACROSS THE REGION THIS EARLY TUESDAY MORNING. WITHIN THESE
SHOWERS...CIGS DROP BACK BUT REMAIN WITHIN VFR CATEGORY. LATEST
RUC13/HRRR POINTS TOWARD A RENEW REGION OF SHOWERS EAST OF I81 AND
MIGRATING ACROSS THE REGION. WE WILL PLACE A TEMPO GROUP FOR MVFR
CIGS AT THIS TIME. THESE SHOWERS DEPART TO OUR EAST AROUND SUNRISE
WITH BORDERLINE VFR/MVFR CIGS REMAINING IN ITS WAKE. AS DAYTIME
HEATING COMMENCES...EXPECTATIONS ARE FOR THE CIGS TO IMPROVE TO
VFR.
THE CHANCE FOR CONVECTION APPEARS RATHER LOW AT THIS TIME AS THE
BEST DYNAMICS REMAIN TO OUR WEST AND NORTH. FOR THIS REASON...WE
WILL UTILIZE THE PROB30 GROUP NORTH OF KPOU FOR LATE MORNING INTO
THE MID AFTERNOON HOURS.
WINDS OVERNIGHT WILL BE SOUTH AT 5 KT OR LESS. A WEAK COLD FRONT
WILL TRACK THROUGH THE REGION BY MIDDAY TUESDAY. SO...WINDS WILL
BECOME WEST TO SOUTHWEST AT AROUND 10 KT.
OUTLOOK...
TUE NT-THU NT...VFR. NO SIG WX.
FRI-SAT...VFR/MVFR. CHC -SHRA.
&&
.FIRE WEATHER...
NO FIRE CONCERNS AS SHOWERS MOVE IN OVERNIGHT AND TEMPERATURES
DROP INTO THE 40S AT MOST LOCATIONS. LOW RHS TUESDAY WILL BE IN
MAINLY THE 45 TO 55 PERCENT RANGE. SCT SHOWERS WILL AFFECT MOST OF
THE REGION...ESPECIALLY IN THE AFTERNOON WITH THE POSSIBLE
ACCOMPANIMENT OF THUNDERSTORMS.
&&
.HYDROLOGY...
TOTAL QPFS SHOULD BE GENERALLY UNDER A QUARTER OF AN INCH...
ALTHOUGH LOCALLY UP TO A HALF INCH IS POSSIBLE. PERHAPS A DRY
PERIOD TUE MORNING BEFORE THE SHOWERS RETURN.
&&
.CLIMATE...
RECORD HIGHS
ALBANY NY: RECORDS DATE BACK TO 1874
MARCH 12: 67 DEGREES 1890
THE HIGH TODAY 69 DEGREES (AT 2:45 PM EDT)
MARCH 13: 70 DEGREES 1946
(PROJECT HIGH TUESDAY 67 DEGREES) NORMAL HIGH IS 43 DEGREES AND
LOW 24 DEGREES
GLENS FALLS NY: RECORDS DATE BACK TO 1949 MARCH 12: 66 DEGREES
1977 TIED AT 66 DEGREES AS OF 5 PM
MARCH 13: 71 DEGREES 1990 (PROJECTED HIGH TUESDAY 66 DEGREES)
NORMAL HIGH IS 41 DEGREES AND LOW 19 DEGREES
POUGHKEEPSIE NY: RECORDS DATE BACK TO 1949
MARCH 12: 65 DEGREES 1977
THE HIGH SO TODAY 72 DEGREES AS OF 5 PM
MARCH 13: 82 DEGREES 1990 (PROJECTED HIGH TUESDAY 72 DEGREES)
NORMAL HIGH IS 47 DEGREES AND LOW 24 DEGREES
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...ELH/NAS
NEAR TERM...HWJIV/KGM
SHORT TERM...ELH/HWJIV
LONG TERM...KGM
AVIATION...BGM
FIRE WEATHER...ELH
HYDROLOGY...IAA/HWJIV
CLIMATE...
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
214 PM EDT TUE MAR 13 2012
.PREV DISCUSSION... /ISSUED 745 AM EDT TUE MAR 13 2012/
UPDATE...
SENDING A QUICK UPDATE MAINLY TO INCREASE POPS ACROSS THE AREA.
SHOWERS HAVE INCREASED IN COVERAGE...WITH ISOLATED LIGHTNING
STRIKES...SO HAVE UPDATED THE WX GRIDS TO INCLUDE THUNDER
BEGINNING IMMEDIATELY...THOUGH HAVE LIMITED THUNDER TO SLIGHT
CHANCE. HRRR HAS A GOOD HANDLE ON PRECIPITATION AND HAS THE
SHOWERS PUSHING THROUGH THE CWA THROUGH THE MORNING HOURS. IT ALSO
DOES NOT REALLY DEVELOP ANY ADDITIONAL ACTIVITY THIS AFTERNOON SO
TRENDS WILL HAVE TO BE MONITORED IN CASE POPS NEED TO BE LOWERED
ACROSS NORTH GEORGIA EARLIER.
TDP
PREV DISCUSSION... /ISSUED 318 AM EDT TUE MAR 13 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE OVER THE WESTERN ATLANTIC CONTINUES TO RIDGE INTO
THE SOUTHEAST. MEANWHILE THE REMNANTS OF A FRONT...ASSOCIATED
WITH THE MIDLEVEL LOW THAT PUSHED THROUGH THE CENTER OF THE
COUNTRY...CONTINUES TO APPROACH THE AREA. MOIST SOUTHERLY FLOW
AROUND THE WESTERN PERIPHERY OF THE HIGH WILL ALLOW INSTABILITY TO
CLIMB SIGNIFICANTLY TODAY...WITH MLCAPE VALUES EXCEEDING 1000 J/KG
IN SOME AREAS. LIMITING FACTOR FOR STORM DEVELOPMENT WILL BE THE
AMOUNT OF DEEP MOISTURE AVAILABLE...THUS POPS TODAY REMAIN IN THE
SLIGHT CHANCE TO CHANCE CATEGORY. VERY LITTLE SHEAR TO SPEAK OF
AND THUS DESPITE THE INCREASING INSTABILITY...DO NOT EXPECT SEVERE
STORMS.
TEMPERATURES TODAY WILL AGAIN BE ON THE INCREASE...WITH HIGH TEMPS
PROGGED IN THE 70S JUST ABOUT EVERYWHERE. HAVE GENERALLY SIDED
WITH THE WARMER MET/GFS TEMPS AS IT IS IN BETTER AGREEMENT WITH
ECMWF.
THE FRONT MOVES THROUGH THE AREA LATE TONIGHT INTO EARLY
WEDNESDAY...BUT IN THE END IT IS HARDLY ANYTHING MORE THAN A
BRIEF WIND SHIFT AS ALL DYNAMICS REMAIN TO THE NORTH. TEMPERATURES
WILL REMAIN VERY WARM...CLIMBING INTO THE 80S IN MANY AREAS /STILL
BELOW RECORD HIGHS/. THE FRONT WILL DO LITTLE TO SENSIBLE WEATHER
EXCEPT TO PUSH THE BETTER MOISTURE SOUTH...AND THUS HAVE TRENDED
POPS DOWN FOR WEDNESDAY AFTERNOON WITH ONLY SLIGHT CHANCE
REMAINING SOUTH AND NO POPS FOR WEDNESDAY NIGHT. THIS IS SHORT-
LIVED...HOWEVER...AS RIDGING BUILDING IN ALOFT AND CONTINUED
SOUTHERLY FLOW WILL BRING MOISTURE BACK TO THE REGION FOR THE
EXTENDED.
TDP
LONG TERM /THURSDAY THROUGH MONDAY/...
ECMWF AND GFS KEEP A PROGRESSIVE FLOW OVER THE CWA AT THE EARLY PART
OF THE LONG TERM...BUT THEN BUILDS A LARGE H5 RIDGE OVER THE EASTERN
U.S. DURING THE WEEKEND WHICH WILL HOLD INTO THE EARLY PART OF NEXT
WEEK. FOR THURSDAY AND FRIDAY...A SERIES OF SHORT WAVES WILL MOVE
THROUGH THE FLOW KEEPING THE RISK OF SHOWERS/THUNDERSTORMS OVER THE
CWA. MODELS BEGIN DIFFERING ON THE SOLUTION FOR THE WEEKEND. GFS
DOESNT CLEAR OUT THE MOISTURE COMPLETELY AND THIS WOULD KEEP THE
RISK OF SHOWERS/THUNDERSTORMS IN THE FORECAST THROUGH THE WEEKEND.
THE ECMWF BUILDS A RIDGE OF HIGH PRESSURE AT THE SURFACE WHICH NOSES
INTO THE CWA. THIS BRINGS MORE STABLE AND SLIGHTLY COOLER AIR INTO
THE CWA...BUT CONTINUES TO HOLD ON TO MOISTURE. THE END RESULT OF
BOTH MODELS IS THERE IS ENOUGH MOISTURE TO KEEP THE RISK OF AT LEAST
SHOWERS IN THE LONG TERM FOR THE WEEKEND AND INTO EARLY NEXT WEEK.
MEX GUIDANCE IS INDICATING RECORD OR NEAR RECORD HIGH TEMPS FOR
THURSDAY AND FRIDAY WITH A SLIGHT COOL DOWN FOR THE WEEKEND AND INTO
EARLY NEXT WEEK AS THE SURFACE FLOW BECOMES EAST TO NORTHEAST. THIS
IS THE SECOND NIGHT IN A ROW THAT THE MODELS ARE GOING FOR
RECORD/NEAR RECORD TEMPS AND SEE NO REASON TO GO AGAINST THIS AT
THIS TIME.
17
&&
.AVIATION...
18Z UPDATE...
IMMEDIATE CONCERN IS LIKELIHOOD AND COVERAGE OF SHRA OR EVEN TSRA
THIS AFTERNOON. CONTINUE TO SEE ISOLD SHRA...SOME HEAVY...OVER ATL
METRO AND ALL AREAS SOUTH. WITH THIS COVERAGE...USED VCSH IN MOST
AREAS. ADDED VCTS AT KMCN AND KCSG WHERE COVERAGE OF SHRA/TSRA WILL
BE MORE WIDESPREAD. OTHER CONCERN IS POSSIBILITY OF RADIATIONAL
FOG/STRATUS LATE TONIGHT. NO FRONT OR DRY ADVECTION EXPECTED TO
PUSH IN BEHIND PRECIP TONIGHT...SO DEWPOINTS WILL REMAIN HIGH. IF
WE GET ENOUGH CLEARING AND CALM SFC WINDS SHOULD SEE FAIRLY GOOD
FOG EVENT. NOT SURE WE AGREE WITH GUIDANCE FCSTS OF LIFR VSBYS WITH
NO CIGS IN THIS PATTERN SO HAVE KEPT VSBYS AT 1-2SM WITH CIGS OF
500FT FROM 10Z-13Z. IFR RADIATIONAL FOG VERY RARE AT KATL
...PERHAPS THERE IS AN ISSUE WITH GUIDANCE THIS TIME OF YEAR. NO
OTHER PROBLEMS EXPECTED.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON PRECIP COVERAGE THIS AFTERNOON AND IFR
CIGS/VSBYS THIS MORNING. HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 74 53 83 52 / 80 10 10 5
ATLANTA 73 57 81 59 / 90 10 10 5
BLAIRSVILLE 71 51 76 49 / 60 10 10 5
CARTERSVILLE 76 50 80 49 / 90 10 10 10
COLUMBUS 74 56 83 56 / 90 10 20 5
GAINESVILLE 72 54 80 56 / 90 10 10 5
MACON 75 54 83 50 / 60 10 20 5
ROME 77 51 81 50 / 70 10 10 10
PEACHTREE CITY 73 50 80 46 / 90 10 10 5
VIDALIA 80 59 84 58 / 30 10 20 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
13
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
745 AM EDT TUE MAR 13 2012
.PREV DISCUSSION... /ISSUED 716 AM EDT TUE MAR 13 2012/
UPDATE...
SENDING A QUICK UPDATE MAINLY TO INCREASE POPS ACROSS THE AREA.
SHOWERS HAVE INCREASED IN COVERAGE...WITH ISOLATED LIGHTNING
STRIKES...SO HAVE UPDATED THE WX GRIDS TO INCLUDE THUNDER
BEGINNING IMMEDIATELY...THOUGH HAVE LIMITED THUNDER TO SLIGHT
CHANCE. HRRR HAS A GOOD HANDLE ON PRECIPITATION AND HAS THE
SHOWERS PUSHING THROUGH THE CWA THROUGH THE MORNING HOURS. IT ALSO
DOES NOT REALLY DEVELOP ANY ADDITIONAL ACTIVITY THIS AFTERNOON SO
TRENDS WILL HAVE TO BE MONITORED IN CASE POPS NEED TO BE LOWERED
ACROSS NORTH GEORGIA EARLIER.
TDP
PREV DISCUSSION... /ISSUED 318 AM EDT TUE MAR 13 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE OVER THE WESTERN ATLANTIC CONTINUES TO RIDGE INTO
THE SOUTHEAST. MEANWHILE THE REMNANTS OF A FRONT...ASSOCIATED
WITH THE MIDLEVEL LOW THAT PUSHED THROUGH THE CENTER OF THE
COUNTRY...CONTINUES TO APPROACH THE AREA. MOIST SOUTHERLY FLOW
AROUND THE WESTERN PERIPHERY OF THE HIGH WILL ALLOW INSTABILITY TO
CLIMB SIGNIFICANTLY TODAY...WITH MLCAPE VALUES EXCEEDING 1000 J/KG
IN SOME AREAS. LIMITING FACTOR FOR STORM DEVELOPMENT WILL BE THE
AMOUNT OF DEEP MOISTURE AVAILABLE...THUS POPS TODAY REMAIN IN THE
SLIGHT CHANCE TO CHANCE CATEGORY. VERY LITTLE SHEAR TO SPEAK OF
AND THUS DESPITE THE INCREASING INSTABILITY...DO NOT EXPECT SEVERE
STORMS.
TEMPERATURES TODAY WILL AGAIN BE ON THE INCREASE...WITH HIGH TEMPS
PROGGED IN THE 70S JUST ABOUT EVERYWHERE. HAVE GENERALLY SIDED
WITH THE WARMER MET/GFS TEMPS AS IT IS IN BETTER AGREEMENT WITH
ECMWF.
THE FRONT MOVES THROUGH THE AREA LATE TONIGHT INTO EARLY
WEDNESDAY...BUT IN THE END IT IS HARDLY ANYTHING MORE THAN A
BRIEF WIND SHIFT AS ALL DYNAMICS REMAIN TO THE NORTH. TEMPERATURES
WILL REMAIN VERY WARM...CLIMBING INTO THE 80S IN MANY AREAS /STILL
BELOW RECORD HIGHS/. THE FRONT WILL DO LITTLE TO SENSIBLE WEATHER
EXCEPT TO PUSH THE BETTER MOISTURE SOUTH...AND THUS HAVE TRENDED
POPS DOWN FOR WEDNESDAY AFTERNOON WITH ONLY SLIGHT CHANCE
REMAINING SOUTH AND NO POPS FOR WEDNESDAY NIGHT. THIS IS SHORT-
LIVED...HOWEVER...AS RIDGING BUILDING IN ALOFT AND CONTINUED
SOUTHERLY FLOW WILL BRING MOISTURE BACK TO THE REGION FOR THE
EXTENDED.
TDP
LONG TERM /THURSDAY THROUGH MONDAY/...
ECMWF AND GFS KEEP A PROGRESSIVE FLOW OVER THE CWA AT THE EARLY PART
OF THE LONG TERM...BUT THEN BUILDS A LARGE H5 RIDGE OVER THE EASTERN
U.S. DURING THE WEEKEND WHICH WILL HOLD INTO THE EARLY PART OF NEXT
WEEK. FOR THURSDAY AND FRIDAY...A SERIES OF SHORT WAVES WILL MOVE
THROUGH THE FLOW KEEPING THE RISK OF SHOWERS/THUNDERSTORMS OVER THE
CWA. MODELS BEGIN DIFFERING ON THE SOLUTION FOR THE WEEKEND. GFS
DOESNT CLEAR OUT THE MOISTURE COMPLETELY AND THIS WOULD KEEP THE
RISK OF SHOWERS/THUNDERSTORMS IN THE FORECAST THROUGH THE WEEKEND.
THE ECMWF BUILDS A RIDGE OF HIGH PRESSURE AT THE SURFACE WHICH NOSES
INTO THE CWA. THIS BRINGS MORE STABLE AND SLIGHTLY COOLER AIR INTO
THE CWA...BUT CONTINUES TO HOLD ON TO MOISTURE. THE END RESULT OF
BOTH MODELS IS THERE IS ENOUGH MOISTURE TO KEEP THE RISK OF AT LEAST
SHOWERS IN THE LONG TERM FOR THE WEEKEND AND INTO EARLY NEXT WEEK.
MEX GUIDANCE IS INDICATING RECORD OR NEAR RECORD HIGH TEMPS FOR
THURSDAY AND FRIDAY WITH A SLIGHT COOL DOWN FOR THE WEEKEND AND INTO
EARLY NEXT WEEK AS THE SURFACE FLOW BECOMES EAST TO NORTHEAST. THIS
IS THE SECOND NIGHT IN A ROW THAT THE MODELS ARE GOING FOR
RECORD/NEAR RECORD TEMPS AND SEE NO REASON TO GO AGAINST THIS AT
THIS TIME.
17
&&
.AVIATION...
12Z UPDATE...
IFR TO LIFR CIGS HAVE DEVELOPED ACROSS THE NORTHERN TAFS THIS
MORNING WITH -SHRA AND MVFR VSBY AS WELL. MCN AND CSG STILL VFR
ON CIGS AND HOVERING MVFR ON VSBY. SHOULD SEE GRADUAL IMPROVEMENT
THROUGH THE MORNING BUT EXPECT MAINLY IFR CONDITIONS TO REMAIN
THROUGH 18Z...THEN LIFTING TO MVFR AND VFR BY 00Z. ALL GUIDANCE
INDICATING VLIFR CONDITIONS TOMORROW WITH RADIATIONAL FOG
DEVELOPING. HAVE INCLUDED 1SM FEW001...LATER FORECASTS WILL WORK
OUT THE DETAILS. THUNDER IS POSSIBLE AT ANY TIME TODAY BUT
EXPECTING MOSTLY -SHRA SO HAVE NOT INCLUDED TSRA IN TAFS AT THIS
TIME. SOUTHWEST WINDS THROUGH THE PERIOD...GENERALLY BELOW 5KT
EXCEPT BRIEFLY HIGHER THIS AFTERNOON.
//ATL CONFIDENCE...12Z UPDATE...
HIGH ON WINDS.
MEDIUM ON CIGS/VSBY THIS MORNING...MEDIUM-HIGH ON CIGS/VSBY
WEDNESDAY MORNING.
MEDIUM ON OCCURRENCE OF THUNDER...LOW ON POTENTIAL IMPACTS TO ATL.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 75 53 83 52 / 80 10 10 5
ATLANTA 74 57 81 59 / 90 10 10 5
BLAIRSVILLE 71 51 76 49 / 60 10 10 5
CARTERSVILLE 76 50 80 49 / 90 10 10 10
COLUMBUS 75 56 83 56 / 90 10 20 5
GAINESVILLE 72 54 80 56 / 90 10 10 5
MACON 76 54 83 50 / 70 10 20 5
ROME 77 51 81 50 / 70 10 10 10
PEACHTREE CITY 75 50 80 46 / 90 10 10 5
VIDALIA 78 59 84 58 / 30 10 20 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TDP
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
716 AM EDT TUE MAR 13 2012
.UPDATE...
SENDING A QUICK UPDATE MAINLY TO INCREASE POPS ACROSS THE AREA.
SHOWERS HAVE INCREASED IN COVERAGE...WITH ISOLATED LIGHTNING
STRIKES...SO HAVE UPDATED THE WX GRIDS TO INCLUDE THUNDER
BEGINNING IMMEDIATELY...THOUGH HAVE LIMITED THUNDER TO SLIGHT
CHANCE. HRRR HAS A GOOD HANDLE ON PRECIPITATION AND HAS THE
SHOWERS PUSHING THROUGH THE CWA THROUGH THE MORNING HOURS. IT ALSO
DOES NOT REALLY DEVELOP ANY ADDITIONAL ACTIVITY THIS AFTERNOON SO
TRENDS WILL HAVE TO BE MONITORED IN CASE POPS NEED TO BE LOWERED
ACROSS NORTH GEORGIA EARLIER.
TDP
&&
.PREV DISCUSSION... /ISSUED 318 AM EDT TUE MAR 13 2012/
SHORT TERM /TODAY THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE OVER THE WESTERN ATLANTIC CONTINUES TO RIDGE INTO
THE SOUTHEAST. MEANWHILE THE REMNANTS OF A FRONT...ASSOCIATED
WITH THE MIDLEVEL LOW THAT PUSHED THROUGH THE CENTER OF THE
COUNTRY...CONTINUES TO APPROACH THE AREA. MOIST SOUTHERLY FLOW
AROUND THE WESTERN PERIPHERY OF THE HIGH WILL ALLOW INSTABILITY TO
CLIMB SIGNIFICANTLY TODAY...WITH MLCAPE VALUES EXCEEDING 1000 J/KG
IN SOME AREAS. LIMITING FACTOR FOR STORM DEVELOPMENT WILL BE THE
AMOUNT OF DEEP MOISTURE AVAILABLE...THUS POPS TODAY REMAIN IN THE
SLIGHT CHANCE TO CHANCE CATEGORY. VERY LITTLE SHEAR TO SPEAK OF
AND THUS DESPITE THE INCREASING INSTABILITY...DO NOT EXPECT SEVERE
STORMS.
TEMPERATURES TODAY WILL AGAIN BE ON THE INCREASE...WITH HIGH TEMPS
PROGGED IN THE 70S JUST ABOUT EVERYWHERE. HAVE GENERALLY SIDED
WITH THE WARMER MET/GFS TEMPS AS IT IS IN BETTER AGREEMENT WITH
ECMWF.
THE FRONT MOVES THROUGH THE AREA LATE TONIGHT INTO EARLY
WEDNESDAY...BUT IN THE END IT IS HARDLY ANYTHING MORE THAN A
BRIEF WIND SHIFT AS ALL DYNAMICS REMAIN TO THE NORTH. TEMPERATURES
WILL REMAIN VERY WARM...CLIMBING INTO THE 80S IN MANY AREAS /STILL
BELOW RECORD HIGHS/. THE FRONT WILL DO LITTLE TO SENSIBLE WEATHER
EXCEPT TO PUSH THE BETTER MOISTURE SOUTH...AND THUS HAVE TRENDED
POPS DOWN FOR WEDNESDAY AFTERNOON WITH ONLY SLIGHT CHANCE
REMAINING SOUTH AND NO POPS FOR WEDNESDAY NIGHT. THIS IS SHORT-
LIVED...HOWEVER...AS RIDGING BUILDING IN ALOFT AND CONTINUED
SOUTHERLY FLOW WILL BRING MOISTURE BACK TO THE REGION FOR THE
EXTENDED.
TDP
LONG TERM /THURSDAY THROUGH MONDAY/...
ECMWF AND GFS KEEP A PROGRESSIVE FLOW OVER THE CWA AT THE EARLY PART
OF THE LONG TERM...BUT THEN BUILDS A LARGE H5 RIDGE OVER THE EASTERN
U.S. DURING THE WEEKEND WHICH WILL HOLD INTO THE EARLY PART OF NEXT
WEEK. FOR THURSDAY AND FRIDAY...A SERIES OF SHORT WAVES WILL MOVE
THROUGH THE FLOW KEEPING THE RISK OF SHOWERS/THUNDERSTORMS OVER THE
CWA. MODELS BEGIN DIFFERING ON THE SOLUTION FOR THE WEEKEND. GFS
DOESNT CLEAR OUT THE MOISTURE COMPLETELY AND THIS WOULD KEEP THE
RISK OF SHOWERS/THUNDERSTORMS IN THE FORECAST THROUGH THE WEEKEND.
THE ECMWF BUILDS A RIDGE OF HIGH PRESSURE AT THE SURFACE WHICH NOSES
INTO THE CWA. THIS BRINGS MORE STABLE AND SLIGHTLY COOLER AIR INTO
THE CWA...BUT CONTINUES TO HOLD ON TO MOISTURE. THE END RESULT OF
BOTH MODELS IS THERE IS ENOUGH MOISTURE TO KEEP THE RISK OF AT LEAST
SHOWERS IN THE LONG TERM FOR THE WEEKEND AND INTO EARLY NEXT WEEK.
MEX GUIDANCE IS INDICATING RECORD OR NEAR RECORD HIGH TEMPS FOR
THURSDAY AND FRIDAY WITH A SLIGHT COOL DOWN FOR THE WEEKEND AND INTO
EARLY NEXT WEEK AS THE SURFACE FLOW BECOMES EAST TO NORTHEAST. THIS
IS THE SECOND NIGHT IN A ROW THAT THE MODELS ARE GOING FOR
RECORD/NEAR RECORD TEMPS AND SEE NO REASON TO GO AGAINST THIS AT
THIS TIME.
17
AVIATION...
06Z UPDATE...
MAINLY VFR CONDITIONS ACROSS THE AREA AT AFD/TAF TIME...WITH SOME
MVFR AND IFR VSBYS IN AREAS OF PATCHY FOG. GUIDANCE HAS NOT
HANDLED TRENDS WELL...FORECASTING MUCH LOWER CONDITIONS THAN
OBSERVED. OVERALL THOUGH EXPECT A LOWERING TREND TO CONTINUE WITH
IFR CIGS DEVELOPING NEAR 12Z. SE WINDS SHIFT SW NEAR 12Z AS WELL.
CIGS WILL LIFT THIS AFTERNOON BUT SHOULD REMAIN MVFR THROUGH 00Z
OR SO. THERE IS A CHANCE OF THUNDER THIS AFTERNOON BUT CONFIDENCE
IS LOW ON WHERE STORMS WILL DEVELOP. WILL CONTINUE PROB30 GROUP
FOR ALL TAFS FOR NOW. GUIDANCE HINTING AT LIFR FOG DEVELOPING
WEDNESDAY MORNING BUT HAVE ONLY INTRODUCED MVFR VSBY AT THIS TIME.
//ATL CONFIDENCE...
06Z UPDATE...
HIGH ON WINDS.
MEDIUM ON VSBY.
MEDIUM ON OCCURRENCE OF CONVECTION 18-00Z...LOW ON POTENTIAL
IMPACTS TO ATL.
MEDIUM-LOW ON CIGS...ESPECIALLY POTENTIAL DEVELOPMENT AND TIMING
OF IFR CONDITIONS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 75 53 83 52 / 80 10 10 5
ATLANTA 74 57 81 59 / 90 10 10 5
BLAIRSVILLE 71 51 76 49 / 60 10 10 5
CARTERSVILLE 76 50 80 49 / 90 10 10 10
COLUMBUS 75 56 83 56 / 90 10 20 5
GAINESVILLE 72 54 80 56 / 90 10 10 5
MACON 76 54 83 50 / 70 10 20 5
ROME 77 51 81 50 / 70 10 10 10
PEACHTREE CITY 75 50 80 46 / 90 10 10 5
VIDALIA 78 59 84 58 / 30 10 20 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS LINCOLN IL
904 PM CDT WED MAR 14 2012
.DISCUSSION...
ISSUED 904 PM CDT WED MAR 14 2012
MADE A FEW MINOR ADJUSTMENTS TO THE FORECAST FOR SKY COVER AND
PRECIPITATION CHANCES OVERNIGHT. THE LATEST SATELLITE LOOP SHOWS A
FEW LOW CLOUDS IN CENTRAL IL...WITH CONVECTIVE DEBRIS CLOUDS IN
SOUTHEAST IL. MAINLY CLEAR SKIES WILL BE THE RULE EARLY TONIGHT AS
THE CONVECTIVE DEBRIS MOVES OUT OF THE AREA. SCATTERED MID AND
THEN LOW CLOUDS WILL INCREASE IN AREAS NORTHWEST OF THE IL RIVER
OVERNIGHT AS A WEAK SURFACE BOUNDARY MOVES TOWARD NW IL. THE
LATEST WRF AND HRRR MODELS INDICATE SOME LIGHT SHOWERS MAY
ACCOMPANY THE CLOUDS IN NORTH CENTRAL IL...SO WILL KEEP AT LEAST A
20 POP IN THE OVERNIGHT FORECAST.
WILL KEEP THE CHANCE POPS IN SOUTHEAST IL SINCE HIGH INSTABILITY
AIR IS IN PLACE WITH CAPES OF 2000-2500 AND WEAK UPPER LEVEL
FORCING COULD PRODUCE SCATTERED T-STORMS TONIGHT.
WITH UNSEASONABLY MILD DEW POINTS IN THE UPPER 50S TO LOWER 60S...
OVERNIGHT LOWS WILL ONLY DIP INTO THE LOWER 60S...WHICH THE
PREVIOUS FORECAST HAS A GOOD HANDLE ON.
MILLER
&&
.AVIATION...
ISSUED 710 PM CDT WED MAR 14 2012
ISOLATED THUNDERSTORMS IN CENTRAL ILLINOIS EARLY THIS EVENING WERE
DEVELOPING ON THE EDGE OF AN INSTABILITY AXIS AND HAD JUST ENOUGH
FORCING FROM A WEAK SHORTWAVE. THESE THUNDERSTORMS...AS WELL AS
ADDITIONALLY DEVELOPING STORMS...ARE EXPECTED TO MOVE SLOWLY
NORTHEAST TOWARD THE VICINITY OF THE KDEC AND KCMI TAF SITES THIS
EVENING. CIGS WITH ANY STORMS ARE EXPECTED TO REMAIN AT VFR
LEVELS...BUT THE STORMS WILL BE CAPABLE OF HAIL AND ISOLATED WIND
GUSTS.
LATER THIS EVENING AND OVERNIGHT AFTER 04Z TO 05Z SCATTERED MID
CLOUDS WILL BE THE RULE. DUE TO THE HIGH SURFACE DEW POINTS AND
ONLY SCT CLOUDS MUCH OF THE NIGHT...WE ARE EXPECTING LIGHT FOG TO
DEVELOP WITH MVFR VISIBILITY AROUND 08-10Z...AND CONTINUING INTO
MID MORNING. A SLOWLY APPROACHING COLD FRONT INTO NW
ILLINOIS AND INCREASING LOW LEVEL CONVERGENCE WILL RESULT IN A SCT
TO BROKEN DECK OF STRATOCUMULUS BY DAYBREAK.
UNSEASONABLY HIGH TEMPS AND DEW POINTS THURSDAY AFTERNOON WILL
RESULT IN INCREASING INSTABILITY AGAIN. IT IS DIFFICULT TO PICK
OUT ANY UPPER LEVEL FORCING IN THE WEAK WSW FLOW. HOWEVER...EVEN A
MINOR IMPULSE COULD PRODUCE SOME SCATTERED T-STORMS AFTER 18Z IN
CENTRAL IL...SO JUST WENT WITH CB FOR NOW ALONG/SOUTH OF I-72.
MILLER
&&
.PREV DISCUSSION...
ISSUED 252 PM CDT WED MAR 14 2012
18Z SFC MAP SHOWED A LATE SPRING PATTERN IN PLACE AS SOUTHWEST WINDS
GUSTING UP TO 30 MPH AHEAD OF A COLD FRONT IN WESTERN
IOWA...HELPED BOOST TEMPERATURES TO RECORD LEVELS THE UPPER
70S AND LOWER 80S. SEVERAL DAYS OF SUSTAINED SOUTHERLY FLOW HAS
ALLOWED DEWPOINTS TO CLIMB TO UNSEASONABLY HIGH LEVELS IN THE
LOWER 60S. ALOFT...BROAD WEST-SOUTHWEST MID LEVEL FLOW FEATURED
SEVERAL WEAK EMBEDDED SHORTWAVES WHICH WILL BE THE FOCUS FOR
THUNDERSTORM CHANCES THE NEXT FEW DAYS.
SHORT TERM...TONIGHT THROUGH THURSDAY
POTENTIAL CONVECTION FOR THE SOUTHEAST HALF OF THE AREA LATE THIS
AFTERNOON AND EVENING IS FIRST FORECAST CONCERN. WARM AND HUMID
BOUNDARY LAYER COMBINED WITH STEEP MID LEVEL LAPSE RATES AND
INCREASING MOISTURE ADVECTION BELOW 800 MB HAVE LED TO AN UNCAPPED
ATMOSPHERE WITH SURFACE BASED CAPES OF 2500-3000 J/KG. INCREASING
DPVA AHEAD OF A WEAK SHORTWAVE LIFTING NE OUT OF OKLAHOMA SHOULD
LEAD TO AN INCREASE IN CONVECTION ACROSS SOUTHEAST MISSOURI AND
SOUTHERN ILLINOIS OVER THE NEXT COUPLE HOURS. WIND FIELDS ALOFT
ARE UNCHARACTERISTICALLY WEAK FOR EARLY SPRING...WITH 0-6 KM
EFFECTIVE SHEAR ONLY 25 KTS. THIS SHOULD LEAD TO A
DISORGANIZED/PULSE TYPE THUNDERSTORM MODE AND EVEN WITH HIGH
INSTABILITY WOULD ONLY EXPECT SOME NEAR SVR WIND GUSTS AND HAIL
PRIMARILY IN A 3PM-7PM WINDOW...AND BEST CHANCES SOUTH OF I-70. THIS
THINKING IS SUPPORTED BY LATEST RUN HIGH-RES HRRR AND WRF-NMM
MODEL RUNS...WITH ANY CONVECTION PUSHING INTO INDIANA AFTER 7 OR 8
PM.
THE NEXT FOCUS FOR THUNDERSTORM DEVELOPMENT LOOKS TO BE
AHEAD OF THE COLD FRONT TO OUR NORTHWEST. ISOLATED TO SCATTERED
ELEVATED STORMS SHOULD FORM LATER THIS EVENING NEAR OR EAST OF THE
MISSISSIPPI RIVER AS 30-35 KT WSW ORIENTED LOW LEVEL JET DEVELOPS.
DUE TO LIMITED INSTABILITY SEVERE STORMS ARE NOT EXPECTED WITH
THIS ACTIVITY AS IT DROPS SOUTHEAST OVERNIGHT.
THE COLD FRONT WILL BECOME ALIGNED WITH THE UPPER LEVEL FLOW ON
THURSDAY AND TEND TO PUSH MORE EAST THAN SOUTH. CURRENT GUIDANCE
SUGGESTS THE FRONT WILL NOT MAKE IT INTO OUR CWA SO ANOTHER DAY
WITH HIGHS NEAR 80. ASSUMING THE FRONT STAYS TO OUR NORTH AND
WASHES OUT...ANY CONVECTION WOULD BE DRIVEN BY SUBTLE SHORTWAVE
ENERGY. HAVE MAINTAINED LOW CHC POPS DUE TO UNCERTAINTY IN
TIMING OR LOCATION OF DEVELOPMENT...BUT WITH HIGH INSTABILITY HAIL
AND GUSTY WINDS WOULD BE POSSIBLE.
LONG TERM...FRIDAY THROUGH WEDNESDAY
THE EXTENDED PORTION OF THE FORECAST WILL FEATURE AN AMPLIFIED
UPPER AIR PATTERN WITH A WESTERN TROUGH DEEPENING AS IT APPROACHES
THE ROCKIES EARLY NEXT WEEK...WHILE A STRONG RIDGE BUILDS ACROSS
THE EASTERN THIRD OF THE COUNTRY. THIS WILL KEEP THE LOCAL AREA
BATHED IN SOUTHERLY FLOW AND TEMPERATURES MORE TYPICAL OF MID TO
LATE MAY WITH HIGHS IN THE 70S TO NEAR 80 AND LOWS IN THE UPPER 50S.
DEW POINTS WILL CONTINUE TO BE UNSEASONABLY HIGH IN THE UPPER 50S
TO LOWER 60S...GIVING A SOMEWHAT HUMID FEEL TO THE AIR. THE BEST
CHANCE OF THUNDERSTORMS DURING THE PERIOD WILL BE SATURDAY WHEN A
MORE ORGANIZED SHORTWAVE LIFTS FROM THE CENTRAL PLAINS INTO THE
LOWER GREAT LAKES. HAVE TRIED TO FOCUS ANOTHER PERIOD OF HIGHER
POPS LATE IN THE EXTENDED WHEN THE UPPER TROUGH TRACKS EAST INTO
THE PLAINS. LATEST 12Z RUN GFS AND ECMWF HAVE SLOWED THIS SYSTEM
WITH AN UPPER LOW CUTTING OFF IN THE SOUTHERN OR CENTRAL PLAINS.
THIS WOULD KEEP THE AREA IN SOUTHERLY FLOW THROUGH MID WEEK WITH
EASTERN FRINGES OF A MORE UNSETTLED PATTERN APPROACHING THE
MISSISSIPPI RIVER VALLEY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
710 PM CDT WED MAR 14 2012
.DISCUSSION...
ISSUED 252 PM CDT WED MAR 14 2012
18Z SFC MAP SHOWED A LATE SPRING PATTERN IN PLACE AS SOUTHWEST WINDS
GUSTING UP TO 30 MPH AHEAD OF A COLD FRONT IN WESTERN
IOWA...HELPED BOOST TEMPERATURES TO RECORD LEVELS THE UPPER
70S AND LOWER 80S. SEVERAL DAYS OF SUSTAINED SOUTHERLY FLOW HAS
ALLOWED DEWPOINTS TO CLIMB TO UNSEASONABLY HIGH LEVELS IN THE
LOWER 60S. ALOFT...BROAD WEST-SOUTHWEST MID LEVEL FLOW FEATURED
SEVERAL WEAK EMBEDDED SHORTWAVES WHICH WILL BE THE FOCUS FOR
THUNDERSTORM CHANCES THE NEXT FEW DAYS.
SHORT TERM...TONIGHT THROUGH THURSDAY
POTENTIAL CONVECTION FOR THE SOUTHEAST HALF OF THE AREA LATE THIS
AFTERNOON AND EVENING IS FIRST FORECAST CONCERN. WARM AND HUMID
BOUNDARY LAYER COMBINED WITH STEEP MID LEVEL LAPSE RATES AND
INCREASING MOISTURE ADVECTION BELOW 800 MB HAVE LED TO AN UNCAPPED
ATMOSPHERE WITH SURFACE BASED CAPES OF 2500-3000 J/KG. INCREASING
DPVA AHEAD OF A WEAK SHORTWAVE LIFTING NE OUT OF OKLAHOMA SHOULD
LEAD TO AN INCREASE IN CONVECTION ACROSS SOUTHEAST MISSOURI AND
SOUTHERN ILLINOIS OVER THE NEXT COUPLE HOURS. WIND FIELDS ALOFT
ARE UNCHARACTERISTICALLY WEAK FOR EARLY SPRING...WITH 0-6 KM
EFFECTIVE SHEAR ONLY 25 KTS. THIS SHOULD LEAD TO A
DISORGANIZED/PULSE TYPE THUNDERSTORM MODE AND EVEN WITH HIGH
INSTABILITY WOULD ONLY EXPECT SOME NEAR SVR WIND GUSTS AND HAIL
PRIMARILY IN A 3PM-7PM WINDOW...AND BEST CHANCES SOUTH OF I-70. THIS
THINKING IS SUPPORTED BY LATEST RUN HIGH-RES HRRR AND WRF-NMM
MODEL RUNS...WITH ANY CONVECTION PUSHING INTO INDIANA AFTER 7 OR 8
PM.
THE NEXT FOCUS FOR THUNDERSTORM DEVELOPMENT LOOKS TO BE
AHEAD OF THE COLD FRONT TO OUR NORTHWEST. ISOLATED TO SCATTERED
ELEVATED STORMS SHOULD FORM LATER THIS EVENING NEAR OR EAST OF THE
MISSISSIPPI RIVER AS 30-35 KT WSW ORIENTED LOW LEVEL JET DEVELOPS.
DUE TO LIMITED INSTABILITY SEVERE STORMS ARE NOT EXPECTED WITH
THIS ACTIVITY AS IT DROPS SOUTHEAST OVERNIGHT.
THE COLD FRONT WILL BECOME ALIGNED WITH THE UPPER LEVEL FLOW ON
THURSDAY AND TEND TO PUSH MORE EAST THAN SOUTH. CURRENT GUIDANCE
SUGGESTS THE FRONT WILL NOT MAKE IT INTO OUR CWA SO ANOTHER DAY
WITH HIGHS NEAR 80. ASSUMING THE FRONT STAYS TO OUR NORTH AND
WASHES OUT...ANY CONVECTION WOULD BE DRIVEN BY SUBTLE SHORTWAVE
ENERGY. HAVE MAINTAINED LOW CHC POPS DUE TO UNCERTAINTY IN
TIMING OR LOCATION OF DEVELOPMENT...BUT WITH HIGH INSTABILITY HAIL
AND GUSTY WINDS WOULD BE POSSIBLE.
LONG TERM...FRIDAY THROUGH WEDNESDAY
THE EXTENDED PORTION OF THE FORECAST WILL FEATURE AN AMPLIFIED
UPPER AIR PATTERN WITH A WESTERN TROUGH DEEPENING AS IT APPROACHES
THE ROCKIES EARLY NEXT WEEK...WHILE A STRONG RIDGE BUILDS ACROSS
THE EASTERN THIRD OF THE COUNTRY. THIS WILL KEEP THE LOCAL AREA
BATHED IN SOUTHERLY FLOW AND TEMPERATURES MORE TYPICAL OF MID TO
LATE MAY WITH HIGHS IN THE 70S TO NEAR 80 AND LOWS IN THE UPPER 50S.
DEW POINTS WILL CONTINUE TO BE UNSEASONABLY HIGH IN THE UPPER 50S
TO LOWER 60S...GIVING A SOMEWHAT HUMID FEEL TO THE AIR. THE BEST
CHANCE OF THUNDERSTORMS DURING THE PERIOD WILL BE SATURDAY WHEN A
MORE ORGANIZED SHORTWAVE LIFTS FROM THE CENTRAL PLAINS INTO THE
LOWER GREAT LAKES. HAVE TRIED TO FOCUS ANOTHER PERIOD OF HIGHER
POPS LATE IN THE EXTENDED WHEN THE UPPER TROUGH TRACKS EAST INTO
THE PLAINS. LATEST 12Z RUN GFS AND ECMWF HAVE SLOWED THIS SYSTEM
WITH AN UPPER LOW CUTTING OFF IN THE SOUTHERN OR CENTRAL PLAINS.
THIS WOULD KEEP THE AREA IN SOUTHERLY FLOW THROUGH MID WEEK WITH
EASTERN FRINGES OF A MORE UNSETTLED PATTERN APPROACHING THE
MISSISSIPPI RIVER VALLEY.
&&
.AVIATION...
ISSUED 710 PM CDT WED MAR 14 2012
ISOLATED THUNDERSTORMS IN CENTRAL ILLINOIS EARLY THIS EVENING WERE
DEVELOPING ON THE EDGE OF AN INSTABILITY AXIS AND HAD JUST ENOUGH
FORCING FROM A WEAK SHORTWAVE. THESE THUNDERSTORMS...AS WELL AS
ADDITIONALLY DEVELOPING STORMS...ARE EXPECTED TO MOVE SLOWLY
NORTHEAST TOWARD THE VICINITY OF THE KDEC AND KCMI TAF SITES THIS
EVENING. CIGS WITH ANY STORMS ARE EXPECTED TO REMAIN AT VFR
LEVELS...BUT THE STORMS WILL BE CAPABLE OF HAIL AND ISOLATED WIND
GUSTS.
LATER THIS EVENING AND OVERNIGHT AFTER 04Z TO 05Z SCATTERED MID
CLOUDS WILL BE THE RULE. DUE TO THE HIGH SURFACE DEW POINTS AND
ONLY SCT CLOUDS MUCH OF THE NIGHT...WE ARE EXPECTING LIGHT FOG TO
DEVELOP WITH MVFR VISIBILITY AROUND 08-10Z...AND CONTINUING INTO
MID MORNING. A SLOWLY APPROACHING COLD FRONT INTO NW
ILLINOIS AND INCREASING LOW LEVEL CONVERGENCE WILL RESULT IN A SCT
TO BROKEN DECK OF STRATOCUMULUS BY DAYBREAK.
UNSEASONABLY HIGH TEMPS AND DEW POINTS THURSDAY AFTERNOON WILL
RESULT IN INCREASING INSTABILITY AGAIN. IT IS DIFFICULT TO PICK
OUT ANY UPPER LEVEL FORCING IN THE WEAK WSW FLOW. HOWEVER...EVEN A
MINOR IMPULSE COULD PRODUCE SOME SCATTERED T-STORMS AFTER 18Z IN
CENTRAL IL...SO JUST WENT WITH CB FOR NOW ALONG/SOUTH OF I-72.
MILLER
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
747 PM EDT WED MAR 14 2012
.UPDATE/AVIATION...
WRN FLANK OF LL RIDGE SLOW TO ERODE THIS EVENING DUE IN PART TO
RATHER WK LL MSTR ADVTN OUT OF THE MID MS VALLEY. 100MB MIXED LYR
CINH SUPPRESSING BOTH UPSTREAM CONVN AS WELL AS MORE SIG CU DVLPMNT
AND AS SUCH WILL CUT POPS GOING FORWARD THIS EVENING. IN ADDN...WILL
DROP LT NIGHT MENTION IN LIGHT OF HRRR/RUC DEPICTION OF VEERING AND
FURTHER WKNG OF LL FLW AFT MIDNIGHT.
VFR CONDS AT THE TERMINALS XPCD THROUGH THE PD...CAVEAT REMAINS THOUGH
W/SOME POTENTIAL FOR MVFR CIGS/VSBYS TWD DAWN ASSUMING GREATER SFC
BASED MSTR PLUME ACRS CNTRL IL CAN ADVT INTO THE AREA. HWVR W/LAMP
GUIDANCE TRENDING SHARPLY DRIER W/SFC TDS AND GENERAL WKNG SFC
GRADIENT SIDED W/A MUCH MORE OPTIMISTIC 00Z FCST.
&&
.SHORT TERM.../TONIGHT THROUGH THURSDAY NIGHT/
MAIN FOCUS WILL BE ON CONVECTIVE CHANCES THROUGH THE PERIOD AS WELL
AS CONTINUATION OF UNSEASONABLE WARM TEMPERATURES.
AS EXPECTED...TEMPERATURES HAVE SOARED WELL INTO THE 70S THIS
AFTERNOON WITH INCREASING LL FLOW AND STRONG MIXING. ELEVATED MIXED
LAYER IS KEEPING CLOUDS AT BAY FOR THE TIME BEING ACROSS MUCH OF THE
REGION. AS WE PROGRESS INTO THIS EVENING...THIS WILL CHANGE AS NOSE
OF LL THETA E SURGE AND INCREASING ISENTROPIC LIFT MOVES ACROSS
INDIANA INTO OHIO. LOCAL WRF MOST AGGRESSIVE WITH THIS FEATURE
FORCING CONVECTION TO INITIATE BY LATE AFTERNOON TO OUR WEST AND
SWINGING IT THROUGH THE AREA THROUGH MIDNIGHT. NAM KEEP ACTIVITY
SUPPRESSED FURTHER SOUTH. MIDDLE ROAD MODELS (HRRR/4KM SPC WRF) ALSO
FOCUS BULK OF CONVECTION ACROSS CNTRL/SOUTHERN INDIANA WITH
ISOL/WIDELY SCT CONVECTION INTO PORTIONS OF NORTHERN INDIANA. VIS
SAT SHOWS EXPANDING CU FIELD ACROSS CENTRAL ILLINOIS WHERE SFC
DEWPTS WERE NOW IN THE LOWER 60S. AT 18Z...ISOLATED SHOWERS WERE
NOTED SOUTHWEST OF ST LOUIS...WITH A FEW LIGHTNING STRIKES SHOWING
UP IN THE BOOTHILL OF MISSOURI...WHICH 14-15ZZ HRRR AND 12Z 4KM SPC
WRF PLACED PERFECTLY...WITH NAM SHOWING NO DEVELOPMENT. THE
LIGHTNING STRIKES WERE NOTED ON NOSE OF MID 60 DEWPTS. AM INCLINED
TO LEAN TOWARDS THESE MODELS AND THEIR TRENDS...WHICH BLEND NICELY
WITH INHERITED GRIDS. SPC HAS CONFINED SLGT RISK FURTHER SOUTH INTO
SOUTHERN ILLINOIS AND SW INDIANA. WILL NEED TO MONITOR CONVECTIVE
DEVELOPMENT INTO THIS EVENING WITH RISK OF STRONG STORMS IN PLACE.
WITH THE INCREASE IN LL MSTR...GRIDS NEEDED TO BE PATCHED UP TO
INCREASE OVERNIGHT LOWS CLOSER TO 60...AS WELL AS SUBSEQUENT
INCREASING IN DEWPTS. FOG POTENTIAL STILL LOOMS LATER TONIGHT AS
WEAK BOUNDARY SLIDES SOUTH TOWARDS THE AREA. HOWEVER...WITH
POTENTIAL OF EVENING CONVECTION AND CHANCES IT COULD MESS UP LL
PROFILES...WILL NOT MAKE ANY CHANGES IN REGARDS TO PREV INSERTION OF
FOG.
BOUNDARY WILL STALL OUT ACROSS THE AREA THURSDAY INTO THURSDAY
EVENING PUSHING SOUTHWARD. THIS WILL CAUSE NUMEROUS ISSUES WITH THE
FORECAST WITH POTENTIAL FOR WIDESPREAD CLOUD COVER...POSSIBLY FOG
AND CHANCES FOR SHOWERS AND STORMS. BROADBRUSHED APPROACH BEST
OPTION AT THIS POINT WITH DECREASE IN POPS IN NW AREAS BY THURS NGT
AS DRIER AIR TRIES TO FILTER IN. CAN`T REALLY ADD MUCH DETAIL TO
GRIDS AT THIS POINT WITH SEVERAL SCENARIOS POSSIBLE. UNSEASONABLY
WARM TEMPS WILL STILL BE IN STORE WITH HIGHS INTO THE 70S.
&&
.LONG TERM...
FEW CHANGES TO LONG TERM GRIDS WITH CRALLBLEND INIT IN BALLPARK.
UNSEASONABLY WARM PATTERN CONTINUES THROUGH THE PERIOD WITH DEEP
TROUGH DEVELOPING IN THE WEST AND STAUNCH RIDGE FOR LATE MARCH
DEVELOPING OVER THE MIDWEST. MEDIUM RANGE MODELS HAVE DIFFERENCES IN
THE DETAILS AS EXPECTED WITH NUMEROUS SHORT WAVES AND ABUNDANT
MOISTURE. PWATS STILL EXPECTED ABOVE AN INCH THROUGH THE PERIOD WITH
SURFACE DEWPOINTS IN THE 50S AND POOLING INTO 60S AT TIMES. THIS
WILL SET STAGE FOR PERIODS OF SHOWERS AND THUNDERSTORMS DEPENDENT ON
TIMING OF EACH WAVE. SHEAR PROFILES REMAIN WEAK WHILE MUCAPES ABOVE
2000 J/KG AT TIMES SO ISOLATED SEVERE STORMS REMAIN A POSSIBILITY.
TEMPERATURES WILL REMAIN 20 TO 25 DEGREES ABOVE NORMAL THROUGH END
OF PERIOD...POSSIBLY HIGHER NEXT WEEK DEPENDING ON DEGREE OF CLOUD
COVER. HIGHS IN THE 80S REMAIN A POSSIBILITY IF FULL MIXING CAN BE
ACHIEVED NEXT WEEK. WITH SUCH A DEEP SYSTEM TO THE WEST FEEL MODELS
ARE TOO FAST WITH APPROACH OF TROUGH FOR MIDDLE OF NEXT WEEK AND
THUS WED WILL CONTINUE TO BE WARM. RAISED ALLBLEND INIT TEMPS
SEVERAL DEGREES IN LINE WITH DAY 5 AND 6 TEMPS.
&&
.AVIATION.../18Z TAFS/
HIGH CLOUDS SLOWLY STREAMING TOWARDS THE REGION WILL CAUSE LITTLE
IMPACT THROUGH THE AFTERNOON. MAIN FOCUS IS DEEPER MSTR AND LIFT
NOTED ACROSS WESTERN ILLINOIS. HI RES MODELS INDICATE CONVECTIVE
DEVELOPMENT EXPECTED AS ELEVATED INSTABILITY CONTINUES TO
INCREASE. AGITATED CU FIELD NOTED ON NOSE OF THE INCREASING LIFT
AND A FEW SHOWERS HAVE DEVELOPED SE OF ST LOUIS. PREV TAFS HAVE
HANDLE ON CONVECTIVE POTENTIAL THIS EVENING WITH ISOL TO SCT
COVERAGE BEING HANDLED BY VCTS MENTION. HI RES MODELS CONTINUE TO
BRING IN A GOOD DEAL OF FOG LATER TONIGHT AND LINGER INTO MUCH OF
THE DAY THURSDAY AS WEAK BOUNDARY DRIFTING SOUTH INTO THE REGION
LIKELY STALLS OUT. GIVEN POSSIBLE IMPACTS OF CONVECTION THIS
EVENING ON FOG POTENTIAL...HAVE LEFT LATTER PART OF TAFS ALONE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...FISHER
LONG TERM...LASHLEY
AVIATION...T
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1147 PM CDT MON MAR 12 2012
.AVIATION...
PATCHY GROUND FOG EXPECTED THAT MAY REDUCE VISIBILITIES TO 1 TO 4
MILES THROUGH 13Z. THEN...VFR CONDITIONS TO CONTINUE THROUGH 06Z/14.
WITH CLEAR SKIES FROM WEAK HIGH PRESSURE. LIGHT WESTERLY WINDS TO
BECOME NEARLY CALM TUESDAY MORNING BEFORE SHIFTING TO THE SOUTH
IN THE AFTERNOON. ..NICHOLS..
&&
.PREV DISCUSSION... /ISSUED 310 PM CDT MON MAR 12 2012/
SYNOPSIS...
12Z UA ANALYSIS HAD A 700MB LOW OVER WESTERN MINNESOTA WITH
SEVERAL TROFS RUNNING FROM THE WESTERN GREAT LAKES BACK INTO THE
PLAINS. A MODERATELY STRONG LLJ RAN FROM THE OKLAHOMA PANHANDLE
INTO THE GREAT LAKES. SATELLITE TRENDS SHOWS A VORT MAX MOVING
FROM NORTHERN MISSOURI INTO NORTHERN ILLINOIS WHILE THE MAIN VORT
MAX MOVES INTO NORTHERN WISCONSIN. RADAR SHOWS SPRINKLES OVER THE
AREA WITH SOME LOW CONVECTION OVER NORTHEAST ILLINOIS.
18Z SFC ANALYSIS HAS A WEAK LOW NEAR KDLH WITH A WARM FRONT RUNNING
SOUTHEAST TO NEAR DETROIT. A COLD FRONT RAN FROM THE LOW SOUTH TO
KUIN. DEW POINTS WERE IN THE 50S AND 60S OVER THE GREAT LAKES AND
LOWER MISSISSIPPI VALLEY WITH 30S AND 40S OVER MUCH OF THE PLAINS.
SHORT TERM...TONIGHT AND TUESDAY...
REFER TO THE CLIMATE SECTION BELOW FOR RECORD HIGHS FOR MARCH 13TH
AND 14TH.
CURRENT OBSERVATIONS THROUGH 20Z COMBINED WITH RECENT RUC TRENDS
INDICATE THE WINDOW OF OPPORTUNITY FOR ANY NEW CONVECTION IS
CLOSING. RADAR INDICATES SPRINKLES WITH SOME VERY MINOR SHOWERS OVER
THE SOUTHEAST HALF OF THE CWFA BUT RUC TRENDS INDICATE THE
INSTABILITY NEEDED TO GET ANYTHING STRONGER GOING WILL END BY 2130Z.
THUS SPRINKLES WITH PERHAPS A FEW SHRA WILL CONTINUE THROUGH SUNSET
WITH POSSIBLY AN ISOLD TSRA IN THE FAR EASTERN/SOUTHEASTERN CWFA.
SATELLITE TRENDS INDICATE THE CLOUDS ARE TAKING ON A MORE CELLULAR
NATURE AND WILL SLOWLY DISSIPATE WITH SUNSET.
SO A CLEARING TREND WILL OCCUR TONIGHT AS THE STORM SYSTEM MOVES
INTO CANADA. HIGH PRESSURE BUILDING INTO THE CWFA LATE TONIGHT WILL
RESULT IN LIGHT WINDS WHICH SHOULD ALLOW TEMPERATURES TO BECOME
CHILLY BUT STILL ABOVE NORMAL.
THE HIGH WILL INITIALLY LIMIT MIXING ON TUESDAY UNTIL IT MOVES EAST
OF THE AREA. RETURN FLOW DEVELOPING BY MID DAY COMBINED WITH THE
STRONG MARCH SUN WILL ALLOW TEMPERATURES TO CLIMB WELL ABOVE NORMAL.
THE NORTHERN THIRD OR SO OF THE CWFA SHOULD REACH THE UPPER 60S WITH
70 TO 75 ELSEWHERE. ..08..
LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BOTH SFC AND UPPER RIDGE
AXIS WILL MIGRATE OFF TO THE EAST OF THE CWA INTO WED MORNING
ALLOWING RETURN FLOW TO INCREASE LATE TUE NIGHT FOR NON-DIURNAL
TEMP CURVES. LOWS WILL PROBABLY OCCUR FROM 03Z-07Z WED BEFORE STEADY
TO SLOW RISE TREND BEGINS. AS SFC FRONT TRIES TO SAG TOWARD THE CWA
FROM THE NORTHWEST...THE CWA WILL BECOME UNDER FULL INFLUENCE OF
WARM THRUST. ONLY THE WET BIASED 12Z GFS BREAKS OUT PRECIP ON WED
BEFORE 00Z THU AND WILL REMOVE ANY DAYTIME POPS. MORE INSOLATION AND
EXTENT OF CURRENTLY PROGGED THERMAL PROFILES SUGGEST HIGHS IN THE
MID TO UPPER 70S ON WED WITH THE SHOT AT A FEW 80S...ALL OF WHICH
WILL BE RECORD HIGH TERRITORY FOR ALL CLIMATE SITES FOR MARCH 14TH.
FLATTENING RIDGE-RIDING VORT WILL COMBINE WITH LLVL MOISTURE
CONVERGENCE ALONG THE INCOMING FRONT FOR A CHANCE AT SOME NOCTURNAL
SHOWERS AND THUNDERSTORMS WED NIGHT. IF A STORM COULD GET GOING IN
THE LOCAL AREA WED AFTERNOON AND EARLY EVENING AND BECOME SOMEWHAT
ORGANIZED...FCST SOUNDINGS SUGGEST A POTENTIAL FOR A SVR STORM WITH
LARGE HAIL AND DAMAGING WIND...BUT AGAIN A TRIGGER DOES NOT APPEAR
UNTIL LATER THAT NIGHT. ALSO THESE SVR PARAMETERS ARE BEING
ADVERTISED ON THE GFS AND ESPECIALLY THE NAM FCST SOUNDINGS WHICH MAY
AGAIN BE OVERDOING BOUNDARY LAYER MOISTURE.
THURSDAY AND FRIDAY...FLATTENING NON-SENSIBLE FLOW ACRS THE
MIDWEST...UNSEASONABLY MILD REGIME CONTINUES WITH LITTLE FOCUS FOR
ORGANIZED CONVECTION. WILL KEEP LOW POPS FOR WDLY SCTRD SHOWERS OR
THUNDERSTORMS POPPING UP IN THE AFTERNOON CAPES. HIGHS IN THE MID TO
UPPER 70S BOTH DAYS AS MAY ARRIVES EARLY.
SATURDAY THROUGH MONDAY...MOST 12Z RUN MEDIUM RANGE SOLUTIONS AND
LATEST ENSEMBLES SUGGEST PATTERN TO BECOME HIGH AMPLITUDE SINE WAVE
PATTERN ACRS THE CONUS...WITH THE MID MS RVR VALLEY STUCK IN THE
MIDDLE FOR THE REST OF THE EXTENDED. WARM MOIST CONVEYOR UP OFF THE
WESTERN GULF TO CONTINUE TO FLOW UP INTO THE REGION TO FUEL POSSIBLE
SHOWER AND THUNDERSTORM ACTIVITY...BUT AGAIN NO REAL SYNOPTICS SCALE
FEATURES TO SUGGEST MORE ORGANIZATION TO THE CONVECTION EVIDENT AT
THIS TIME THROUGH AT LEAST MON NIGHT...POSSIBLY NOT UNTIL MID NEXT
WEEK AS HIGH AMPLITUDE PATTERN SLOW TO MOVE. THUS WILL KEEP LOW
DIURNAL CHANCES FOR WDLY SCTRD UNORGANIZED CONVECTION IN MAINLY
DAYTIME HEATING WHICH MAY LEAD TO HIGHS IN THE MID TO UPPER 70S
EVERY DAY. ..12..
CLIMATE... RECORD HIGHS FOR MARCH 13TH...
BURLINGTON........77 IN 2007 AND OTHER YEARS
CEDAR RAPIDS......74 IN 2007
DUBUQUE...........71 IN 2007
MOLINE............77 IN 2007
RECORD HIGHS FOR MARCH 14TH...
BURLINGTON........76 IN 1995
CEDAR RAPIDS......75 IN 1995
DUBUQUE...........72 IN 1995
MOLINE............77 IN 1995
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
934 PM EDT WED MAR 14 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK SLOWLY EAST OF THE REGION TONIGHT. HIGH
PRESSURE WILL BUILD BRIEFLY INTO THE AREA LATER THURSDAY. A WEAK
TROUGH OF LOW PRESSURE WILL APPROACH FROM THE WEST ON FRIDAY AND
CROSS THE STATE LATE FRIDAY AND FRIDAY NIGHT. HIGH PRESSURE WILL
REBUILD INTO THE AREA OVER THE WEEKEND WITH AN UNSEASONABLY WARM
WEATHER PATTERN SHAPING UP FOR NEXT WEEK.
&&
.NEAR TERM /THROUGH THURSDAY/...
UPDATE 2: BASED ON LATEST SPOTTER SNOW REPORTS RECEIVED FROM THE
CARIBOU...FORT FAIRFIELD...PRESQUE ISLE AREA WHICH WERE UP TO 7 TO
8 INCHES AND LATEST MESO-MODEL GUIDANCE...INCLUDING THE 18Z NAM
AND 21Z HRRR MODELS THAT NOW KEEP THE BAND ORIGINATING FROM SRN
NB AIMED TOWARD NE ME OVR THE SAME RELATIVE AREA FOR THE NEXT FEW
HRS; IT APPEARS IMMINENT THAT SOME LOCATIONS COULD EXPERIENCE A
STORM TOTAL UP TO OR JUST OVER 10 INCHES...WITH THE HIGHEST
AMOUNTS CLUSTERED NEAR THE NB BORDER BOUNDED BY LIMESTONE...
CARIBOU...PRESQUE ISLE AND MARS HILL. INDEED...THE AMOUNT OF AREA
TO BE AFFECTED BY HEAVY SN ACCUMULATIONS WITHIN NE AROOSTOOK
COUNTY IS LESS THAN 50 PERCENT OF ZONE 2...BUT IS AFFECTING THE
MOST URBAN AREAS THE MOST. RADAR INDICATES ONE LAST PULSE (PERHAPS
THE LAST) OF MDT TO HVY SN WITH THIS BAND TAKING AIM TOWARD THE
WRNG AREA...SO SNFL RATES UP TO AN INCH AN HR AT TIMES OVR SOME
AREAS CAN BE XPCTD UNTIL MDNGT OR SO BEFORE SN RATES WIND DOWN.
WITH DEEP ELEVATED WARM ADVCN WEAKENING IN THE TROWAL ZONE XTNDG
TOWARD E ME DURG THE LATE NGT/ERLY MORN HRS...ANY REMAINING
ORGANIZED SNFL SHOULD QUICKLY WIND DOWN OVR THE FA AS THE UPPER
LOW BEGINS TO MOVE INTO SRN NB.
UPDATE 1: SENT A QUICK UPDATE TO INCREASE TOTAL SNFL AMOUNTS
TO 4 TO 8 IN ACROSS PORTIONS OF NERN AND FAR NRN AROOSTOOK COUNTY
BASED ON A FEW OBS OF 5 IN ATTM. SOME UNCERTAINTY EXISTS REGARDING
HOW BANDING WILL EVOLVE OVR THE NEXT FEW HRS...WITH NEAR TERM
MODELS SUCH AS THE HRRR SHOWING THE ENHANCED BANDING CURRENTLY
JUST W OF THE ME-NB BORDER POSSIBLY GRAZING FAR NE AROOSTOOK
COUNTY. WILL MONITOR CLOSELY DURG THIS TM.
ORGNL DISC: UPPER LOW TRACKING TOWARDS THE WESTERN BORDER OF
MAINE AS EXPECTED. SOME INSTABILITY ABOVE H850 AND A SHARP UPPER
TROUGH ROTATING AROUND THE CLOSED UPPER LOW IS PRODUCING LOCALLY
HEAVIER SNOW SHOWERS IN FAR NORTHEASTERN ZONES. WILL GO FOR UP TO
5 INCHES IN NE CORNER OF STATE...BUT EXPECT WIDE VARIATIONS FOR
NORTHERN ZONES DUE TO HIT OR MISS NATURE OF THE HEAVIER SNOW
SHOWERS. MOISTURE CONTINUES TO WRAP BACK NORTHWESTWARDS FROM THE
MARITIMES AND WILL HELP PROLONG SNOW IN NORTHERN ZONES WELL INTO
THE NIGHT. DOWN EAST AREAS WILL GET A BRIEF SHOT OF SNOW THIS
EVENING THAT MAY LAY DOWN AN INCH OR SO. THIS WILL BE IN
CONJUNCTION WITH THE UPPER LOW PASSAGE. THE THREAT FOR FZDZ IS
STILL THERE WITH THE RISK FROM NEAR MILO TOWARDS NORTHERN
WASHINGTON COUNTY THIS AFTERNOON AND QUICKLY SHIFTING TO SOUTHERN
WASHINGTON COUNTY THIS EVENING BEFORE THE WARM AIR ALOFT IS GONE.
TEMPERATURES TONIGHT WILL DIP SLIGHTLY IN THE LOWER 20S NORTH AND
UPPER 20S DOWN EAST.
WITH SNOW ENDING IN THE FAR EASTERN ZONES EARLY THURSDAY
MORNING...HIGH PRESSURE WILL BUILD BUT CLOUD COVER ASSOCIATED WITH
A SUBSIDENCE INVERSION WILL BE SLOW TO ERODE FROM THE WEST. EXPECT
SOME CLEARING TOWARDS BANGOR BY AFTERNOON...BUT NOT UNTIL LATE DAY
TOWARDS THE EASTERN BORDER OF THE STATE. HIGHS WILL REACH THE LOW
TO MID 30S TOWARDS THE SJV AND INCREASE TOWARDS DOWN EAST WHERE
LOW 40S ARE LIKELY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL CREST THE REGION THURSDAY NIGHT AND THEN MOVE
EAST OF THE AREA EARLY FRIDAY. MODELS IN GOOD AGREEMENT WITH UPPER
TROUGH APPROACHING FROM THE WEST FRIDAY AND CROSSING THE STATE BY
FRIDAY EVENING. EXPECT ASSOCIATED LOW PRESSURE AND COLD FRONT TO
SPREAD MAINLY RAIN FROM WEST TO EAST ACROSS THE STATE FRIDAY
AFTERNOON. RAIN MAY MIX WITH SNOW ACROSS EXTREME NORTHERN
SECTIONS. THEN AS UPPER TROUGH MOVES EAST OF THE STATE, CONDITIONS
WILL IMPROVE FROM WEST TO EAST FRIDAY NIGHT. QPF AMOUNTS AT THIS
TIME APPEARS TO BE ON THE LIGHT SIDE WITH AMOUNTS GENERALLY BELOW A
QUARTER OF AN INCH. HIGH PRESSURE THEN BUILD ACROSS NEW ENGLAND ON
SATURDAY WITH CLEAR SKIES AND MODERATING TEMPERATURES INTO THE 40S
AND 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
RIDGING BUILDING ALONG THE EAST COAST WILL SET THE STAGE FOR SOME
VERY MILD WEATHER GOING INTO EARLY NEXT WEEK. HIGH PRESSURE ALONG
THE EAST COAST WILL BRING A MOSTLY CLEAR NIGHT SATURDAY NIGHT
FOLLOWED BY A PARTLY SUNNY AND MILD DAY ON SUNDAY. THE LATEST GFS
SHOWS A WEAK COLD FRONT MOVING IN LATE SUNDAY WHICH MAY BRING
INCREASING CLOUDS LATE IN THE DAY. THE ECMWF BRINGS A WEAK FRONT
THROUGH LATER MONDAY. HIGH PRESSURE THEN CONSOLIDATES AGAIN ALONG THE
EAST COAST TUESDAY AS A VERY STRONG RIDGE OF HIGH PRESSURE BUILDS
INTO THE EAST. THIS WILL BRING A PARTLY SUNNY AND VERY MILD DAY ON
TUESDAY. THE STRONGEST INFLUENCE OF THE RIDGING WILL LIKELY COME
WEDNESDAY WHEN WARM WEST TO SOUTHWEST WINDS BOOST TEMPS INTO THE 60S
AND PERHAPS EVEN 70S ACROSS THE REGION. THE VERY WARM TEMPS DURING
THE MID WEEK NEXT WEEK WILL LIKELY RESULT IN LOTS OF SNOW MELT. THE
RELEASE OF SNOW MELT MAY RESULT IN RISES ON RIVERS AND POTENTIAL ICE
JAMS DURING THE MID AND LATE WEEK NEXT WEEK.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR TONIGHT FOR ALL TERMINALS...BCMG MVFR THURSDAY
MORNING AND VFR BY LATE AFTERNOON.
SHORT TERM: VFR THURSDAY NIGHT INTO EARLY FRIDAY THEN CONDITIONS
WILL LOWER TO MVFR/IFR IN RAIN FRIDAY AFTERNOON THROUGH FRIDAY
EVENING AND THEN IMPROVE TO VFR LATER FRIDAY NIGHT. EXPECT VFR
CONDITIONS SATURDAY THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM: SCA WILL CONTINUE INTO EARLY THURSDAY MORNING...BARELY
MEETING CRITERIA WITH WIND GUSTS AROUND 25 KTS AND 5 FT SEAS.
SHORT TERM: WINDS AND SEAS BELOW SCA CRITERIA THURSDAY NIGHT
THROUGH SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 2 AM EDT THURSDAY FOR MEZ002.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MEZ001-
003>006-010-011-015>017-031-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THURSDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...FOSTER
LONG TERM...BLOOMER
AVIATION...VJN
MARINE...VJN/FOSTER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
925 PM EDT WED MAR 14 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK SLOWLY EAST OF THE REGION TONIGHT. HIGH
PRESSURE WILL BUILD BRIEFLY INTO THE AREA LATER THURSDAY. A WEAK
TROUGH OF LOW PRESSURE WILL APPROACH FROM THE WEST ON FRIDAY AND
CROSS THE STATE LATE FRIDAY AND FRIDAY NIGHT. HIGH PRESSURE WILL
REBUILD INTO THE AREA OVER THE WEEKEND WITH AN UNSEASONABLY WARM
WEATHER PATTERN SHAPING UP FOR NEXT WEEK.&&
.NEAR TERM /THROUGH THURSDAY/...
UPDATE 2: BASED ON LATEST SPOTTER SNOW REPORTS RECEIVED FROM THE
CARIBOU...FORT FAIRFIELD...PRESQUE ISLE AREA WHICH WERE UP TO 7 TO
8 INCHES AND LATEST MESO-MODEL GUIDANCE...INCLUDING THE 18Z NAM
AND 21Z HRRR MODELS THAT NOW KEEP THE BAND ORIGINATING FROM SRN
NB AIMED TOWARD NE ME OVR THE SAME RELATIVE AREA FOR THE NEXT FEW
HRS; IT APPEARS IMMINENT THAT SOME LOCATIONS COULD EXPERIENCE UP
TO OR JUST OVER 10 INCHES...WITH THE HIGHEST AMOUNTS CLUSTERED
NEAR THE NB BORDER BOUNDED BY LIMESTONE...CARIBOU...PRESQUE ISLE
AND MARS HILL. INDEED...THE AMOUNT OF AREA TO BE AFFECTED BY HEAVY
SN ACCUMULATIONS WITHIN NE AROOSTOOK COUNTY IS LESS THAN 50
PERCENT OF ZONE 2...BUT IS AFFECTING THE MOST URBAN AREAS THE
MOST. RADAR INDICATE ONE LAST PULSE (PERHAPS THE LAST) OF MDT
TO HVY SN WITH THIS BAND TAKING AIM TOWARD THE WRNG AREA...SO
SNFL RATES UP TO AN INCH AN HR AT TIMES OVR SOME AREAS CAN BE
XPCTD UNTIL MDNGT OR SO BEFORE SN RATES WIND DOWN. WITH DEEP
ELEVATED WARM ADVCN WEAKENING IN THE TROWAL ZONE XTNDG TOWARD E
ME DURG THE LATE NGT/ERLY MORN HRS...ANY REMAINING ORGANIZED SNFL
SHOULD QUICKLY WIND DOWN OVR THE FA AS THE UPPER LOW BEGINS TO
MOVE INTO SRN NB.
UPDATE 1: SENT A QUICK UPDATE TO INCREASE TOTAL SNFL AMOUNTS
TO 4 TO 8 IN ACROSS PORTIONS OF NERN AND FAR NRN AROOSTOOK COUNTY
BASED ON A FEW OBS OF 5 IN ATTM. SOME UNCERTAINTY EXISTS REGARDING
HOW BANDING WILL EVOLVE OVR THE NEXT FEW HRS...WITH NEAR TERM
MODELS SUCH AS THE HRRR SHOWING THE ENHANCED BANDING CURRENTLY
JUST W OF THE ME-NB BORDER POSSIBLY GRAZING FAR NE AROOSTOOK
COUNTY. WILL MONITOR CLOSELY DURG THIS TM.
ORGNL DISC: UPPER LOW TRACKING TOWARDS THE WESTERN BORDER OF
MAINE AS EXPECTED. SOME INSTABILITY ABOVE H850 AND A SHARP UPPER
TROUGH ROTATING AROUND THE CLOSED UPPER LOW IS PRODUCING LOCALLY
HEAVIER SNOW SHOWERS IN FAR NORTHEASTERN ZONES. WILL GO FOR UP TO
5 INCHES IN NE CORNER OF STATE...BUT EXPECT WIDE VARIATIONS FOR
NORTHERN ZONES DUE TO HIT OR MISS NATURE OF THE HEAVIER SNOW
SHOWERS. MOISTURE CONTINUES TO WRAP BACK NORTHWESTWARDS FROM THE
MARITIMES AND WILL HELP PROLONG SNOW IN NORTHERN ZONES WELL INTO
THE NIGHT. DOWN EAST AREAS WILL GET A BRIEF SHOT OF SNOW THIS
EVENING THAT MAY LAY DOWN AN INCH OR SO. THIS WILL BE IN
CONJUNCTION WITH THE UPPER LOW PASSAGE. THE THREAT FOR FZDZ IS
STILL THERE WITH THE RISK FROM NEAR MILO TOWARDS NORTHERN
WASHINGTON COUNTY THIS AFTERNOON AND QUICKLY SHIFTING TO SOUTHERN
WASHINGTON COUNTY THIS EVENING BEFORE THE WARM AIR ALOFT IS GONE.
TEMPERATURES TONIGHT WILL DIP SLIGHTLY IN THE LOWER 20S NORTH AND
UPPER 20S DOWN EAST.
WITH SNOW ENDING IN THE FAR EASTERN ZONES EARLY THURSDAY
MORNING...HIGH PRESSURE WILL BUILD BUT CLOUD COVER ASSOCIATED WITH
A SUBSIDENCE INVERSION WILL BE SLOW TO ERODE FROM THE WEST. EXPECT
SOME CLEARING TOWARDS BANGOR BY AFTERNOON...BUT NOT UNTIL LATE DAY
TOWARDS THE EASTERN BORDER OF THE STATE. HIGHS WILL REACH THE LOW
TO MID 30S TOWARDS THE SJV AND INCREASE TOWARDS DOWN EAST WHERE
LOW 40S ARE LIKELY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL CREST THE REGION THURSDAY NIGHT AND THEN MOVE
EAST OF THE AREA EARLY FRIDAY. MODELS IN GOOD AGREEMENT WITH UPPER
TROUGH APPROACHING FROM THE WEST FRIDAY AND CROSSING THE STATE BY
FRIDAY EVENING. EXPECT ASSOCIATED LOW PRESSURE AND COLD FRONT TO
SPREAD MAINLY RAIN FROM WEST TO EAST ACROSS THE STATE FRIDAY
AFTERNOON. RAIN MAY MIX WITH SNOW ACROSS EXTREME NORTHERN
SECTIONS. THEN AS UPPER TROUGH MOVES EAST OF THE STATE, CONDITIONS
WILL IMPROVE FROM WEST TO EAST FRIDAY NIGHT. QPF AMOUNTS AT THIS
TIME APPEARS TO BE ON THE LIGHT SIDE WITH AMOUNTS GENERALLY BELOW A
QUARTER OF AN INCH. HIGH PRESSURE THEN BUILD ACROSS NEW ENGLAND ON
SATURDAY WITH CLEAR SKIES AND MODERATING TEMPERATURES INTO THE 40S
AND 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
RIDGING BUILDING ALONG THE EAST COAST WILL SET THE STAGE FOR SOME
VERY MILD WEATHER GOING INTO EARLY NEXT WEEK. HIGH PRESSURE ALONG
THE EAST COAST WILL BRING A MOSTLY CLEAR NIGHT SATURDAY NIGHT
FOLLOWED BY A PARTLY SUNNY AND MILD DAY ON SUNDAY. THE LATEST GFS
SHOWS A WEAK COLD FRONT MOVING IN LATE SUNDAY WHICH MAY BRING
INCREASING CLOUDS LATE IN THE DAY. THE ECMWF BRINGS A WEAK FRONT
THROUGH LATER MONDAY. HIGH PRESSURE THEN CONSOLIDATES AGAIN ALONG THE
EAST COAST TUESDAY AS A VERY STRONG RIDGE OF HIGH PRESSURE BUILDS
INTO THE EAST. THIS WILL BRING A PARTLY SUNNY AND VERY MILD DAY ON
TUESDAY. THE STRONGEST INFLUENCE OF THE RIDGING WILL LIKELY COME
WEDNESDAY WHEN WARM WEST TO SOUTHWEST WINDS BOOST TEMPS INTO THE 60S
AND PERHAPS EVEN 70S ACROSS THE REGION. THE VERY WARM TEMPS DURING
THE MID WEEK NEXT WEEK WILL LIKELY RESULT IN LOTS OF SNOW MELT. THE
RELEASE OF SNOW MELT MAY RESULT IN RISES ON RIVERS AND POTENTIAL ICE
JAMS DURING THE MID AND LATE WEEK NEXT WEEK.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR TONIGHT FOR ALL TERMINALS...BCMG MVFR THURSDAY
MORNING AND VFR BY LATE AFTERNOON.
SHORT TERM: VFR THURSDAY NIGHT INTO EARLY FRIDAY THEN CONDITIONS
WILL LOWER TO MVFR/IFR IN RAIN FRIDAY AFTERNOON THROUGH FRIDAY
EVENING AND THEN IMPROVE TO VFR LATER FRIDAY NIGHT. EXPECT VFR
CONDITIONS SATURDAY THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM: SCA WILL CONTINUE INTO EARLY THURSDAY MORNING...BARELY
MEETING CRITERIA WITH WIND GUSTS AROUND 25 KTS AND 5 FT SEAS.
SHORT TERM: WINDS AND SEAS BELOW SCA CRITERIA THURSDAY NIGHT
THROUGH SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 2 AM EDT THURSDAY FOR MEZ002.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MEZ001-
003>006-010-011-015>017-031-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THURSDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...FOSTER
LONG TERM...BLOOMER
AVIATION...VJN
MARINE...VJN/FOSTER
THUS THE REST OF THE PREVIOUS FORECAST DISCUSSION REMAINS THE
SAME.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A BROAD RIDGE ACROSS
THE OHIO VALLEY WITH A DEEP LAYER OF DRY AIR ALOFT. A BROAD AREA
OF HIGH PRESSURE EXTENDS ACROSS THE EASTERN US COAST WITH A
LIGHT SOUTHERLY LOW-LEVEL FLOW LOCALLY. THIS HAS ALLOWED FOR
UNSEASONABLY WARM WEATHER TO CONTINUE. IN FACT, MORGANTOWN AND
ZANESVILLE REACHED 77F, JUST 3 DEGREES SHORT OF THEIR ALL-TIME
RECORD HIGHS FOR MARCH 14TH.
TONIGHT...HIGH PRESSURE AND THE DEEP LAYER OF DRY AIR WILL CONTINUE
TO KEEP SKIES CLEAR EARLY WITH CLOUD COVERAGE INCREASING BY DAWN
AS CIRRUS MOVES IN AHEAD OF DEVELOPING UPSTREAM CONVECTION. WITH
RECENT TRENDS IN OBS AND LAMP/HRRR SUPPORT, OVERNIGHT ARE FORECAST
TO BE AROUND 25 DEGREES ABOVE SEASONAL NORMALS.
THURSDAY...WEAK LOW PRESSURE FROM THE CENTRAL PLAINS WILL MOVE TO
LOWER MICHIGAN BY THURSDAY MORNING. MOISTURE WILL MOVE NORTH FROM THE
GULF OF MEXICO WITH DEW POINTS WARMING INTO THE MID 50S. A WEAK
SHORT WAVE WILL MOVE ACROSS THE AREA EARLY WITH THE NAM 4KM SIMULATED
REFLECTIVITY SUPPORTING CONVECTION PASSING FROM EASTERN OHIO INTO
WV JUST AFTER DAWN. THUS, CANNOT RULE OUT RAIN CHANCE THROUGHOUT
THE DAY. THE BEST CHANCE SHOULD BE IN THE LATE AFTERNOON INTO THE
EVENING WITH INCREASING INSTABILITY. DESPITE MODERATE INSTABILITY
VALUES, MINIMAL WIND SHEAR SHOULD PREVENT STORMS FROM REACHING
SEVERE LEVELS. TEMPERATURES WILL CONTINUE TO BE AROUND 25 DEGREES
ABOVE NORMAL WITH MANY LOCATIONS WARMING INTO THE MID 70S.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
UNSETTLED PATTERN WILL PERSIST THROUGH THE MIDDLE PART OF THE
WEEKEND. AS SHORTWAVES MOVE ACROSS UPPER LEVEL RIDGE PARKED OVER THE
EAST COAST...THIS WILL TEMPORARILY ENHANCE CHANCES FOR
PRECIPITATION. AS LOW PRESSURE MOVES FROM LOWER MICHIGAN THURSDAY
NIGHT INTO NEW ENGLAND FRIDAY NIGHT...THIS MAY ALLOW FOR THE BEST
CHANCE OF PRECIP IN THE PERIOD. MODELS ARE SHOWING LITTLE
CONSISTENCY WITH INSTABILITY FOR THUNDERSTORMS. HAVE GENERALLY GONE
WITH CHANCE STORMS DURING THE AFTERNOON AND EVENING...AND SLIGHT
CHANCE DURING THE OVERNIGHT AND MORNING HOURS. NO CHANGE IN THE
TREND OF WELL ABOVE NORMAL TEMPERATURES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AN UPPER RIDGE WILL AMPLIFY ACROSS THE EASTERN STATES EARLY NEXT
WEEK AND REMAIN IN PLACE THROUGH WEDNESDAY. SURFACE HIGH PRESSURE IS
PROGGED TO HOLD ALONG THE MID ATLANTIC COAST AND MAINTAIN SOUTHWEST
FLOW ACROSS THE UPPER OHIO VALLEY REGION.
ISOLATED SHOWERS CAN STILL BE EXPECTED SUNDAY...WITH GENERALLY DRY
WEATHER MONDAY THROUGH WEDNESDAY. TEMPERATURES WILL REMAIN 20 TO 25
DEGREES ABOVE NORMAL FOR THE EXTENDED PERIOD.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
GENERALLY VFR CONDITIONS WILL CONTINUE ACROSS THE TERMINALS THROUGH
THE TAF PERIOD. BROKEN CUMULUS 3000 TO 4000 FEET IS EXPECTED TO FORM
AFTER DAYBREAK ON THURSDAY AS LOW LEVEL MOISTURE INCREASES AHEAD
OF AN APPROACHING SHORTWAVE TROUGH. COVERAGE OF SCATTERED SHOWERS
AND THUNDERSTORMS IS EXPECTED TO INCREASE FROM WEST TO EAST
THURSDAY AFTERNOON WITH RESTRICTIONS POSSIBLE.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
SCATTERED SHOWERS AND THUNDERSTORMS AND THE POTENTIAL FOR
RESTRICTIONS WILL CONTINUE THROUGH EARLY SATURDAY AS THE UPPER
TROUGH AND ASSOCIATED WEAK SURFACE LOW MOVE EAST TO THE ATLANTIC
COAST. SHOWERS ARE EXPECTED TO BECOME MORE ISOLATED BY SUNDAY UNDER
WEAK RIDGING.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
740 PM EDT WED MAR 14 2012
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE INTO THE GREAT LAKES TOMORROW. THIS WILL
START A PERIOD OF UNSETTLED WEATHER WITH SHOWERS AND THUNDERSTORMS.
HIGH TEMPERATURES WILL REMAIN IN THE 70S THROUGHOUT THE PERIOD.
&&
.NEAR TERM /THROUGH THURSDAY/...
THE 00Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO
WARM OVERNIGHT LOWS A FEW DEGREES.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A BROAD RIDGE ACROSS
THE OHIO VALLEY WITH A DEEP LAYER OF DRY AIR ALOFT. A BROAD AREA
OF HIGH PRESSURE EXTENDS ACROSS THE EASTERN US COAST WITH A
LIGHT SOUTHERLY LOW-LEVEL FLOW LOCALLY. THIS HAS ALLOWED FOR
UNSEASONABLY WARM WEATHER TO CONTINUE. IN FACT, MORGANTOWN AND
ZANESVILLE REACHED 77F, JUST 3 DEGREES SHORT OF THEIR ALL-TIME
RECORD HIGHS FOR MARCH 14TH.
TONIGHT...HIGH PRESSURE AND THE DEEP LAYER OF DRY AIR WILL CONTINUE
TO KEEP SKIES CLEAR EARLY WITH CLOUD COVERAGE INCREASING BY DAWN
AS CIRRUS MOVES IN AHEAD OF DEVELOPING UPSTREAM CONVECTION. WITH
RECENT TRENDS IN OBS AND LAMP/HRRR SUPPORT, HAVE INCREASED
OVERNIGHT LOWS BY 2-3 DEGREES ACROSS MUCH OF THE AREA. THIS WILL
BE AROUND 25 DEGREES ABOVE SEASONAL NORMALS.
THURSDAY...WEAK LOW PRESSURE FROM THE CENTRAL PLAINS WILL MOVE TO
LOWER MICHIGAN BY THURSDAY MORNING. MOISTURE WILL MOVE NORTH FROM THE
GULF OF MEXICO WITH DEW POINTS WARMING INTO THE MID 50S. A WEAK
SHORT WAVE WILL MOVE ACROSS THE AREA EARLY WITH THE NAM 4KM SIMULATED
REFLECTIVITY SUPPORTING CONVECTION PASSING FROM EASTERN OHIO INTO
WV JUST AFTER DAWN. THUS, CANNOT RULE OUT RAIN CHANCE THROUGHOUT
THE DAY. THE BEST CHANCE SHOULD BE IN THE LATE AFTERNOON INTO THE
EVENING WITH INCREASING INSTABILITY. DESPITE MODERATE INSTABILITY
VALUES, MINIMAL WIND SHEAR SHOULD PREVENT STORMS FROM REACHING
SEVERE LEVELS. TEMPERATURES WILL CONTINUE TO BE AROUND 25 DEGREES
ABOVE NORMAL WITH MANY LOCATIONS WARMING INTO THE MID 70S.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
UNSETTLED PATTERN WILL PERSIST THROUGH THE MIDDLE PART OF THE
WEEKEND. AS SHORTWAVES MOVE ACROSS UPPER LEVEL RIDGE PARKED OVER THE
EAST COAST...THIS WILL TEMPORARILY ENHANCE CHANCES FOR
PRECIPITATION. AS LOW PRESSURE MOVES FROM LOWER MICHIGAN THURSDAY
NIGHT INTO NEW ENGLAND FRIDAY NIGHT...THIS MAY ALLOW FOR THE BEST
CHANCE OF PRECIP IN THE PERIOD. MODELS ARE SHOWING LITTLE
CONSISTENCY WITH INSTABILITY FOR THUNDERSTORMS. HAVE GENERALLY GONE
WITH CHANCE STORMS DURING THE AFTERNOON AND EVENING...AND SLIGHT
CHANCE DURING THE OVERNIGHT AND MORNING HOURS. NO CHANGE IN THE
TREND OF WELL ABOVE NORMAL TEMPERATURES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AN UPPER RIDGE WILL AMPLIFY ACROSS THE EASTERN STATES EARLY NEXT
WEEK AND REMAIN IN PLACE THROUGH WEDNESDAY. SURFACE HIGH PRESSURE IS
PROGGED TO HOLD ALONG THE MID ATLANTIC COAST AND MAINTAIN SOUTHWEST
FLOW ACROSS THE UPPER OHIO VALLEY REGION.
ISOLATED SHOWERS CAN STILL BE EXPECTED SUNDAY...WITH GENERALLY DRY
WEATHER MONDAY THROUGH WEDNESDAY. TEMPERATURES WILL REMAIN 20 TO 25
DEGREES ABOVE NORMAL FOR THE EXTENDED PERIOD.
&&
.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
GENERALLY VFR CONDITIONS WILL CONTINUE ACROSS THE TERMINALS THROUGH
THE TAF PERIOD. BROKEN CUMULUS 3000 TO 4000 FEET IS EXPECTED TO FORM
12Z-15Z THURSDAY AS LOW LEVEL MOISTURE INCREASES AHEAD OF AN
APPROACHING SHORTWAVE TROUGH. COVERAGE OF SCATTERED SHOWERS AND
THUNDERSTORMS IS EXPECTED TO INCREASE FROM WEST TO EAST THURSDAY
AFTERNOON WITH RESTRICTIONS POSSIBLE. SOUTHWEST SURFACE WINDS 5 TO
10 KT WILL PREVAIL.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
SCATTERED SHOWERS AND THUNDERSTORMS AND THE POTENTIAL FOR
RESTRICTIONS WILL CONTINUE THROUGH EARLY SATURDAY AS THE UPPER
TROUGH AND ASSOCIATED WEAK SURFACE LOW MOVE EAST TO THE ATLANTIC
COAST. SHOWERS ARE EXPECTED TO BECOME MORE ISOLATED BY SUNDAY UNDER
WEAK RIDGING.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1226 PM EDT TUE MAR 13 2012
.SYNOPSIS...
A WEAK FRONT WILL CROSS THE REGION TODAY WITH THE CHANCE FOR
SHOWERS AND PERHAPS A THUNDERSTORM. HIGH PRESSURE WILL THEN BRING
DRY AND WARM WEATHER UNTIL THE APPROACH OF AN UPPER DISTURBANCE ON
THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHOWERS FELL APART ACROSS THE CWA AS HRRR INDICATED. CLOUD COVER
REMAINS ACROSS THE SOUTHERN HALF OF THE CWA. ADJUSTED CLOUD GRIDS
TO REFLECT IT.
BEHIND THE BOUNDARY A SLIGHT COOL DOWN FOR TONIGHT WITH LOWS INTO
THE 40S, AND READINGS IN THE UPPER 30S ACROSS THE NORTHERN TIER.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
A BROAD RIDGE OF HIGH PRESSURE WILL BE OVER MUCH OF THE EASTERN
STATES WITH THE RIDGE AXIS SLIDING ACROSS THE GREAT LAKES. DRY
WEATHER AND WARM TEMPERATURES MAY THUS BE EXPECTED UNTIL A
SHORTWAVE IN SOUTHWESTERLY FLOW PROVIDES A SHOWER AND THUNDERSTORM
CHANCE ON THURSDAY.
TEMPERATURE READINGS WERE FORECAST ABOUT 20 DEGREES ABOVE THE
SEASONAL AVERAGES USING A GUIDANCE BLEND.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BLEND OF HPC-PREFERRED ECMWF ENSEMBLE MEAN AND NAEFS MODEL OUTPUT
SHOW DEEP TROUGHING ALONG THE PACIFIC COAST RESULTING IN AN
AMPLIFYING RIDGE OVER THE EASTERN CONUS BY NEXT WEEKEND. THIS
PATTERN WOULD ENSURE CONTINUED WARMTH FOR THE UPPER OHIO VALLEY
REGION DURING THE LONG TERM PERIOD AS WELL AS DIMINISHING PRECIP
PROBABILITIES FOLLOWING PASSAGE OF THE AFOREMENTIONED
THURSDAY/FRIDAY SHORTWAVE.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
WARM FRONT HAS SHIFTED JUST FAR ENOUGH NORTH TO ALLOW FOR A PERIOD
OF VFR CONDITIONS ACROSS SOUTHERN PORTS. HOWEVER, ACROSS THE NORTH
IFR TO LOW MVFR CONDITIONS CONTINUE AND WILL DO SO THROUGH THE
MORNING HOURS. AS COLD FRONT APPROACHES, SOUTHERN PORTS WILL LOWER
TO MVFR WITH OCCASIONAL IFR POSSIBLE. SOUTHERLY SFC WINDS WILL
GENERALLY BE FROM 10 TO 15KTS THROUGH THE MORNING, WITH GUSTS TO 20
KTS POSSIBLE. AHEAD OF THE FRONT, SCT SHOWERS, WITH AN ISO TRW, IS
POSSIBLE AT FKL AND DUJ AROUND DAWN. DRIER AIR WILL MOVE IN BEHIND
THE COLD FRONT THIS AFTERNOON BRINGING A RETURN TO VFR CONDITIONS.
WINDS WILL BECOME WESTERLY DURING THE LATE MORNING/EARLY AFTERNOON
HOURS WITH GUSTS TO 20KTS POSSIBLE.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
VFR THROUGH THURSDAY. SHOWERS WILL BE POSSIBLE THURSDAY NIGHT THROUGH
SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
128 AM EDT TUE MAR 13 2012
.SYNOPSIS...
ISSUED AT 413 PM EDT MON MAR 12 2012
UNSEASONABLY WARM WEATHER WILL DOMINATE THIS WEEK AS ABOVE NORMAL
500MB HEIGHTS RISE SLOWLY OVERALL. INTO THE UPCOMING WEEKEND...500MB
HEIGHT ANOMALIES OVER THE UPPER LAKES WILL INCREASE FROM 2 TO 2.5
STANDARD DEVIATIONS ABOVE THE LONG TERM AVG FOR MID MARCH. 850MB
TEMPS WILL ALSO BE RUNNING 2-2.5 STANDARD DEVIATIONS ABOVE THE LONG
TERM AVG. OVERALL...IT WILL PROBABLY FEEL MORE LIKE MID MAY THAN MID
MARCH. AT LEAST HERE AT THE OFFICE...SEVERAL HIGH TEMP RECORDS WILL
PROBABLY BE CHALLENGED OVER THE NEXT 7 DAYS. RAIN CHANCES LOOK
LIMITED WITH TROF SETTING UP WELL TO THE W OVER THE WRN CONUS AND A
STRONG RIDGE BUILDING OVER THE ERN CONUS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 413 PM EDT MON MAR 12 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A WELL-DEFINED MID LEVEL
LOW SPINNING NE THRU WI. MAIN ARC OF STEADIER PCPN ASSOCIATED WITH
SYSTEM HAS LIFTED N AND E THRU UPPER MI TODAY. SCT PCPN IS OCCURRING
CLOSER TO THE CENTER OF THE MID LEVEL LOW WITH COVERAGE GENERALLY
INCREASING. UNDER APPROACHING COLD POCKET ALOFT ASSOCIATED WITH THE
LOW...A FEW LIGHTNING STRIKES HAVE FINALLY BEEN NOTED OVER CNTRL WI.
AFTER MORNING RAINFALL SATURATED THE LOW-LEVELS AND WITH PCPN LESS
WIDESPREAD THIS AFTN...FOG IS FAIRLY WIDESPREAD WITH SOME AREAS OF
DENSE FOG ALONG LAKE MICHIGAN AND WHERE WINDS ARE UPSLOPING.
WITH MID LEVEL LOW MOVING ACROSS THE AREA THIS EVENING...EXPECT
SCT/NMRS SHRA THIS EVENING. MAINTAINED SLIGHT CHC THUNDER OVER THE
SCNTRL THRU LATE AFTN SINCE SHRA ACTIVITY AROUND LOW APPEARS TO BE
INCREASING IN INTENSITY AND A FEW LIGHTNING STRIKES HAVE RECENTLY
OCCURRED IN CNTRL WI. SHORTWAVE CURRENTLY OVER THE DAKOTAS MAY WORK
TO MAINTAIN BETTER COVERAGE OF SHRA INTO THE LATE EVENING HRS OVER
THE NW PORTION OF THE FCST AREA AS IT TRACKS TO LAKE SUPERIOR.
OTHERWISE...PCPN LOOKS TO END RATHER QUICKLY OVERNIGHT FROM W TO E
AS STRONG DRYING SURGES INTO THE AREA UNDERNEATH UPPER JET.
-SHRA MAY LINGER INTO THE MORNING HRS OVER THE FAR NE FCST AREA.
OTHERWISE...THE STRONG DRYING WILL SET THE STAGE FOR A SUNNY DAY
TUE. DEEP DRY AIRMASS WILL SUPPORT DEEP MIXING...PERHAPS TO
800-750MB. PER FCST SOUNDINGS...THAT WILL YIELD MAX TEMPS AROUND 60F
OVER THE SCNTRL WHERE DOWNSLOPING WRLY WINDS WILL AID WARMING. 50S
SHOULD BE THE RULE ELSEWHERE...WITH LWR 40S ON THE W SIDE OF THE
KEWEENAW AND ALONG LAKE SUPERIOR E OF MUNISING DUE TO WINDS OFF THE
COLD WATERS. GIVEN THE VERY DRY AIRMASS ALOFT THAT CAN BE TAPPED...
LEANED TOWARD DWPTS THAT CAN BE ACHIEVED BY MIXING TUE AFTN.
ALTHOUGH POTENTIAL IS THERE FOR DWPTS TO CRASH TOWARD 0F OVER THE
FAR W AND CNTRL FCST AREA...OPTED TO JUST TREND FCST IN THAT
DIRECTION BY LOWERING GOING FCST SEVERAL DEGREES TO AROUND 10F AS A
START. THIS WILL PUT AFTN RH VALUES DOWN AROUND 15PCT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 413 PM EDT MON MAR 12 2012
THE PERIOD STARTS 00Z WEDNESDAY WITH A LOW PRESSURE SYSTEM ENE OF
THE CWA AND A 500MB RIDGE OF HIGH PRESSURE CENTERED JUST W OF THE
CWA. AT THE SAME TIME...AN UPPER SHORTWAVE TROUGH WILL BE OVER THE
NWRN CONUS/WRN CANADA...WITH A SFC LOW OVER SASK AND SFC TROUGHING
LEEWARD OF THE ROCKIES STRETCHING INTO CO.
THE UPPER RIDGE WILL BE OVER THE CENTER OF THE CWA BY 12Z WED. THE
NW CONUS SHORTWAVE WILL BE NEAR THE NRN SASK/MANITOBA
BORDER...PUSHING THE SFC TROUGH FARTHER E INTO FAR WRN MN. THE
EASTWARD MOVING TROUGH COMBINED WITH A SFC RIDGE JUST E OF THE CWA
WILL RESULT IN INCREASING SW WAA TUE NIGHT INTO WED. 850MB TEMPS
WILL INCREASE FROM 0-5C BY 00Z WED TO 10-13C BY 18Z WED. THIS
RESULTS IN VERY WARM TEMPS FOR WED...WITH HIGHS IN THE MID TO UPPER
60S EXPECTED OVER PORTIONS OF CENTRAL AND WRN UPPER MI...ESPECIALLY
IN DOWNSLOPING AREAS. OVER ERN UPPER MI...HIGHS WILL BE LOWER IN THE
LOW TO MID 50S WITH THE SSW FLOW OFF LAKE MI. THROUGH 00Z THU THINGS
SHOULD STAY DRY AS THE SFC TROUGH MOVES INTO THE FAR WRN CWA. THE
NAM SHOWS SOME CONVECTION POPPING UP BETWEEN 18Z WED AND 00Z THU
OVER THE FAR ERN CWA...BUT THE NAM IS ALSO THE FASTEST WITH MOVING
THE COLD FRONT THROUGH. WITH THE CONSENSUS IDEA...THE COLD FRONT
WILL BE MOVING OUT OF THE SERN CWA BY 00Z FRI. CONSENSUS MODELS ALSO
SHOW CONVECTION OVER CENTRAL AND ERN UPPER MI...BUT MAINLY NEAR LAKE
MI AND OVER FAR ERN UPPER MI AFTER 00Z THU. THE HEAVIER CONVECTION
SHOULD STAY S/SE OF THE CWA AS MODELS SHOW TOO MUCH CAPPING THIS FAR
N...SO SLIGHT CHANCE OF THUNDER WAS RETAINED FROM PREVIOUS FORECAST.
THURSDAY...WITH THE COLD FRONT STALLING JUST SE OF THE CWA...RAIN
WILL REMAIN POSSIBLE NEAR LAKE MI AND E...BUT ONLY CHANCE TO SLIGHT
CHANCE POPS SEEM WARRANTED AT THIS TIME. THURSDAY LOOKS TO BE COOLER
BEHIND THE COLD FRONT WITH 850MB TEMPS AROUND 7C...SO HIGHS WILL BE
IN THE 40S NEAR LAKE SUPERIOR AND NEAR 60 NEAR THE WI BORDER.
FOR THE EXTENDED...MODELS SHOW ANOTHER UPPER DISTURBANCE MOVING N OF
THE CWA THU NIGHT...WITH AN UPPER RIDGE MOVING OVER THE CWA ON FRI.
AFTER FRI...CONFIDENCE IS DECREASED SOME AS MODELS SHOW DIFFERING
SOLUTIONS WITH THE PASSAGE OF A SERIES OF SHORTWAVES THROUGH MONDAY.
HOWEVER...WARM CONDITIONS ARE A CERTAINTY INTO EARLY NEXT WEEK GIVEN
STEADY S/SW FLOW WITH SFC HIGH PRESSURE E AND LOW PRESSURE W. USED
CONSENSUS OF MODELS THROUGH THE EXTENDED WITH SLIGHT CHANCE TO LOW
CHANCE POPS AS MODELS SHOW SOME PRECIP/CONVECTION IN THE WAA REGIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 127 AM EDT TUE MAR 13 2012
MID LVL TROF WILL LIFT NE OF THE REGION OVERNIGHT ALLOWING FOR MUCH
DRIER AIR TO MOVE IN FROM THE SW SCOURING OUT STRATUS CLOUD DECK.
MVFR CLOUD DECK SHOULD DISSIPATE BY TAF VALID TIME AT KIWD AND BY 09Z
AT KSAW. AT KCMX...UPSLOPE AIDED IFR CIGS AT KCMX SHOULD ALSO LIFT BY
09Z WITH INFLUX OF DRIER AIR. KEPT LLWS AT KSAW AS WINDS REMAIN
DECOUPLED OVERNIGHT. WITH DEEP MIXING EXPECTED UNDER SUNNY
SKIES...EXPECT WRLY WIND GUSTS TO APPROACH 30 KTS AT KCMX DURING THE
DAY ON TUESDAY AND AOA 20 KTS AT BOTH KSAW AND KIWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 413 PM EDT MON MAR 12 2012
UPPER LEVEL DISTURBANCE AND SURFACE TROF WILL MOVE ENE ACROSS LAKE
SUPERIOR TONIGHT. AHEAD OF THE TROF...SHOWERS AND INCREASINGLY MOIST
AIRMASS WILL SUPPORT SOME FOG...ESPECIALLY OVER WRN AND NRN PORTIONS
OF THE LAKE. FOG SHOULD THIN OUT AFTER TROF PASSES AND WINDS SHIFT
AROUND TO THE W AND INCREASE. WARM AIR ABOVE THE SURFACE WILL LIKELY
KEEP THE MARINE LAYER IN PLACE AND LIMIT THE STRONGER WINDS ALOFT
FROM REACHING THE SURFACE LATE TONIGHT AND TUE. AT THIS TIME...ONLY
EXPECT GUSTS REACHING 30KTS. AFTER TUE...WINDS WILL PROBABLY REMAIN
MOSTLY UNDER 20KTS WITH A RELATIVELY WEAK PRESSURE GRADIENT IN
PLACE. UNSEASONABLY WARM AIRMASS OVER THE UPPER GREAT LAKES WILL
ALSO RESULT IN PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE
LAKE...HELPING TO KEEP WINDS LIGHTER.
&&
.HYDROLOGY...
ISSUED AT 413 PM EDT MON MAR 12 2012
NEAR RECORD TO RECORD SETTING TEMPS YESTERDAY HAS HELPED RIPEN THE
SNOW PACK. RAIN MOVING THROUGH TODAY WILL EXIT THE AREA TONIGHT. THE
BULK OF THE RAIN FELL DURING THE MORNING TO EARLY AFTERNOON HOURS
TODAY...WITH ACCUMULATIONS OF AROUND 0.25 TO 0.70IN. THE
RAIN...COMBINED WITH DEWPOINTS IN THE 40S...WILL HELP TO QUICKEN
SNOWMELT THIS EVENING. AS OF THIS AFTERNOON...LARGER RIVERS ARE
STARTING TO SHOW SOME INCREASED RESPONSE TO THE MELTING AND
PRECIPITATION.
THE RAIN AND SNOW MELT TODAY...COMBINED WITH ABOVE NORMAL
TEMPERATURES THROUGH NEXT WEEKEND WILL LEAD TO A INCREASE IN
RIVER AND STREAM LEVELS OVER THE NEXT SEVERAL DAYS. EXPECT SOME OF
THE RIVERS ACROSS THE AREA TO EXCEED THEIR BANKS BY THE END OF THIS
WEEK. PERSONS LIVING NEAR RIVERS AND STREAMS SHOULD
MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF WALKING
ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
ICE JAM WISE...NOT MUCH ICE HAS BEEN NOTED BY OBSERVERS ON THE
FASTER FLOWING RIVERS OVER NRN UPPER MI. BUT THE FORD RIVER...BOTH
AT HYDE AND THE MOUTH AT LK MI...STILL HAS GOOD ICE COVER THAT
LEADS TO SOME CONCERN FOR ICE JAM POTENTIAL WITH THE FASTER RUNOFF.
ALTHOUGH LIMITED SNOW WAS NOTED NEAR LK MI...THERE IS STILL 3-8IN
OF SNOW ...AND NOHRSC ESTIMATED AROUND 1.25IN OF LIQUID...TOWARDS
THE HEADWATERS THAT WILL BE MELTED OVER THE COMING DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...ROLFSON
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...ROLFSON
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
103 AM EDT TUE MAR 13 2012
.AVIATION...
//DISCUSSION...
SHOWERS WILL CONTINUE TO SETTLE SOUTHEAST OF THE TERMINALS...ENDING
AT YIP/DTW/DET RIGHT ABOUT THE START OF THE FORECAST PERIOD. VFR
CIGS WILL PERSIST A BIT LONGER...WITH ~10KFT AC DECK UNTIL 08Z-10Z.
THEREAFTER...STRATUS WILL WRAP AROUND THE DEPARTING UPPER LOW AND
BRING A SLIGHTLY LOWER DECK INTO MBS/FNT...WITH CIGS IN THE 4-5KFT
AREA LATE TONIGHT INTO EARLY WEDNESDAY. OTHERWISE...CLEARING SKIES
CAN BE EXPECTED DURING THE DAY WITH GUSTY WEST WINDS DURING THE BEST
MIXING FROM LATE MORNING INTO LATE AFTERNOON...WITH WIND GUSTS TO 25
KNOTS AT TIMES. HIGH PRESSURE WILL MAINTAIN CLEAR SKIES INTO THE END
OF THE FORECAST PERIOD...AND ALSO ALLOW WINDS TO DROP OFF QUICKLY
AFTER 22Z-00Z.
//DTW THRESHOLD THREATS...
* NONE
&&
.PREV DISCUSSION...ISSUED 351 PM EDT MON MAR 12 2012
SHORT TERM...THIS EVENING AND TONIGHT
STRONG UPPER LOW NOW LOCATED OVER NORTHERN WISCONSIN WILL CONTINUE
TO TRACK TO THE NE ACROSS LAKE SUPERIOR TONIGHT. THE SURFACE
REFLECTION IS RATHER WEAK AS IT REMAINS AN OPEN TROUGH TIED TO A
CLOSED CIRCULATION FURTHER NW OVER MANITOBA. MID LEVEL DRY SLOT IS
WORKING ITS WAY ACROSS SOUTHERN MI PUSHING THE DEEPER MOISTURE FROM
THIS MORNING OFF TO THE EAST. BREAKS IN THE CLOUD COVER HAS ALLOWED
SOME DIURNAL HEATING OVER FAR SW LOWER MI. TEMPS ARE PUSHING THE
UPPER 60S IN THOSE LOCATIONS. IN ADDITION...S/SW WINDS GUSTING UP TO
25 KNOTS HAS BROUGHT IN ABUNDANT SFC MOISTURE WITH DEWPOINTS IN THE
MID 50S ACROSS ALL OF SOUTHERN MI. THE EXCEPTION IS OVER THE EXTREME
EASTERN PORTIONS OF THE CWA WHERE A SE COMPONENT IS STILL HANGING
ON. THIS HELD THE SUB 1000FT CLOUDS FIRMLY UNTIL ABOUT THE LAST WHEN
THEY STARTED TO SCATTER OUT. THUNDERSTORM COMPLEX FROM EARLIER WEST
OF CHICAGO HAS TRACKED NORTH INTO WESTERN MI NORTH OF MUSKEGON. WITH
WIND SHEAR NEARLY UNIDIRECTIONAL FROM THE SW...COMPLEX IS STRUGGLING
TO MAKE ANY EASTWARD PROGRESS.
FOR TONIGHT...THREAT FOR SEVERE WEATHER LATE THIS EVENING REMAINS
CONDITIONAL ON AMOUNT OF SURFACE BASED INSTABILITY WE CAN ACHIEVE.
THERE LOOKS TO BE PLENTY OF WIDESPREAD LIFT SUPPORTING STORM
DEVELOPMENT WITH THE UPPER LEVEL COLD POOL IN PLACE AND THE ENTRANCE
REGION OF A JET STREAK OVER THE REGION. THERE ARE FAVORABLE WIND
PARAMETERS ASSOCIATED WITH THE FRONTAL PASSAGE. BULK SHEAR VALUES
AROUND 40-50 KNOTS...BOTH 0-3KM AND 0-1 KN HELICITY IN EXCESS OF 300
M2/S2. LOOKING AT CAPE VALUES...THOUGH NAM MUCAPE IS ADVERTISED AT
800J/KG...NEITHER THE NAM OR RUC FIND MUCH IN THE WAY OF SFC BASED
CAPE WITH VALUES UP TO 100-200 J/KG WITH HIGHEST AMOUNTS FOR THE
WESTERN PART OF THE CWA. HIRES MODELS SHOW SOME ISOLATED CELLS
TRYING TO GO UP IN ADVANCE OF THE COLD FRONT WITH THE BULK OF THE
SHOWERS/STORMS OCCURRING THE FRONT ITSELF MAINLY FROM
23Z-05Z...WORKING SOUTH FROM MBS TO DTW. LOOKS LIKE SMALL HAIL AND
WIND GUSTS TO 50MPH WILL BE THE MOST LIKELY RESULTS OF THESE
STORMS...ALTHOUGH IF WE CAN GET MORE SFC BASED INSTABILITY SEVERE
STORMS WILL NOT BE OUT OF THE QUESTION.
LONG TERM...
THE WARM PATTERN LOOKS TO STICKING AROUND FOR THE EXTENDED
PERIOD...WITH POTENTIAL PSEUDO OMEGA BLOCKING PATTERN SETTING UP
LATE IN THE WEEKEND/EARLY NEXT WEEK.
CONSOLIDATING UPPER WAVES TAKES PLACE OVER ONTARIO TOMORROW...WITH
SHORTWAVE TROUGH AXIS AND SLIGHT HEIGHT FALLS TAKING PLACE LATE IN
THE DAY. STILL...WITH FAVORABLE WESTERLY WINDS AND THE TEMP GRADIENT
ADVERTISED (925 MB TEMPS OF 8 C NORTH TO 11 C SOUTH)...LOOKING AT
UPPER 50S NORTH TO MID 60S SOUTH WITH PLENTY OF SUNSHINE.
SURFACE RIDGE AXIS ARRIVING TOMORROW EVENING SHOULD ALLOW FOR
FAVORABLE RADIATING CONDITIONS...BUT WE ALREADY HAVE MODEST LOW
LEVEL WARM ADVECTION RETURNING BY SUNRISE WEDNESDAY. GUIDANCE TEMPS
IN THE 30S APPEAR REASONABLE.
A DRY WARM FRONT EXPECTED TO PUSH NORTH OF SOUTHERN LOWER MICHIGAN
DURING WEDNESDAY AS UPPER LEVEL RIDGE BUILDS OVERHEAD...PUSHING
TEMPS TO 70 DEGREES OR BETTER BASED ON FORECASTED 925 MB TEMPS OF
+15 TO +16 C. THE EXCEPTION WILL BE ACROSS THUMB REGION WHERE FRONT
WILL PROBABLY NOT CLEAR BY DAYS END...WITH BACKED SOUTHEAST FLOW
COMING OFF COOL WATERS OF SOUTHERN LAKE HURON.
DEEP SOUTHWEST FLOW OVER THE CENTRAL CONUS THURSDAY/FRIDAY...WITH
POTENTIAL UPPER LEVEL PV FILAMENT ROLLING THROUGH ON THURSDAY...PER
12Z GFS...TO TRIGGER SHOWERS AND POSSIBLE THUNDERSTORMS...AS
RESPECTABLE SURGE IN MOISTURE TAKES PLACE. CLOUDS AND CONVECTIVE
ACTIVITY COULD BE ENOUGH TO KEEP TEMPS STUCK IN THE UPPER 60S
DESPITE THE VERY MILD START TO THE DAY. THE 12Z EUROPEAN OFFERS A
DIFFERENT SOLUTION AND SUGGESTS THE SHORTWAVE/TROUGH COMING OUT OF
THE NORTHERN PLAINS WILL BE STRONGER...MOVING THROUGH ON FRIDAY.
THIS WOULD TRANSLATE TO A WARM DAY ON THURSDAY (70S) AND BETTER
CHANCE OF SHOWERS ON FRIDAY. THE CANADIAN IS MORE IN LINE WITH THE
GFS...SO WILL NOT MAKE A BIG PUSH TO EXTENDED GRIDS MUCH.
MEDIUM RANGE MODELS STILL FORECASTING AMPLIFIED PATTERN FOR THE
WEEKEND INTO EARLY NEXT WEEK...WITH LONGWAVE TROUGH OUT WEST AND
UPPER LEVEL RIDGE BUILDING NEAR THE GREAT LAKES REGION. ALMOST
SUMMER LIKE RIDGE (582-586 DAM AT 500 MB)...AND TEMPS APPROACHING 80
DEGREES IS NOT OUT OF THE QUESTION AS WE GET TO TUESDAY AS 1000-500
MB THICKNESSES CLIMB TOWARD 564 DAM. LAKE BREEZES WOULD LIKELY BE
COMING INTO PLAY HOWEVER AND WILL NEED TO REMAIN MORE CONSERVATIVE
THAT FAR OUT...ESPECIALLY WITH THE EUROPEAN PROFILES A BIT COOLER.
MARINE...
OUTSIDE OF A FEW POSSIBLE THUNDERSTORMS THIS EVENING...MARINE
CONDITIONS ARE EXPECTED TO REMAIN QUIET. UNUSUALLY MILD AIR IN PLACE
FOR EARLY MARCH WILL LEAD TO STABLE STABLE LOW LEVEL PROFILES OVER
THE GREAT LAKES. THIS WILL MINIMIZE THE GUST POTENTIAL TO AROUND 20
KNOTS OVER THE NEXT SEVERAL DAYS. THOSE STRONGER WINDS LOOKED TO BE
CONFINED TO THE NORTH THIRD OF LAKE HURON TOMORROW...AS CHANNELING
OCCURS WITH WESTERLY FLOW. THE NEXT CHANCE OF THUNDERSTORMS RETURNS
ON THURSDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DG
SHORT TERM...DRK
LONG TERM....SF
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS SPRINGFIELD MO
939 PM CDT WED MAR 14 2012
...MESOSCALE CONVECTIVE DISCUSSION...
.UPDATE...
THE 00Z NAM AND RUC CONTINUE TO INDICATE A SIGNAL FOR ISOLATED TO
WIDELY SCATTERED CONVECTIVE DEVELOPMENT LATE TONIGHT. BOTH MODELS
NOSE A WEAK CORRIDOR OF ISENTROPIC UPGLIDE IN THE 300-305 K LAYER
INTO THE REGION BEGINNING AROUND OR JUST AFTER 09Z. LIFTING
PARCELS FROM THIS SAME LAYER YIELDS LITTLE IF ANY CONVECTIVE
INHIBITION...ESPECIALLY ALONG AND SOUTH OF A PITTSBURG KANSAS TO
LAKE OF THE OZARKS LINE. THE GOING POPS HAVE THIS COVERED WELL.
DESPITE 0-6 KM EFFECTIVE BULK SHEARS AT OR BELOW 20 KNOTS...
MUCAPES IN THE 1800 TO 2400 J/KG RANGE WILL STILL SUPPORT SOME
HAIL POTENTIAL. DID ADD A LIMITED HAIL THREAT TO THE HAZARDOUS
WEATHER OUTLOOK.
SCHAUMANN
&&
.DISCUSSION...
/ISSUED 1255 PM CDT WED MAR 14 2012/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
FOR THE NEAR TERM THIS AFTERNOON...SCATTERED CU CONTINUE TO BUBBLE
UP ACROSS THE REGION...AS COMBINATION OF INCREASING TEMPERATURES AND
NEAR 60 DEWPOINTS HAS ERODED MUCH OF THE INHIBITION EVIDENT ON THIS
MORNING`S 12Z RAOB. DESPITE THIS...DRY AIR ALOFT (ALSO PER 12Z
SOUNDING) AND HIGH LFCS...ALONG WITH NEARLY NON-EXISTENT LOW LEVEL
FORCING SHOULD RESULT IN VERY LOW CONVECTIVE COVERAGE...THIS
AFTERNOON/EARLY EVENING. CURRENT THINKING REMAINS THAT HIGHER
TERRAIN OF THE BOSTON MOUNTAINS AND FAR SOUTH-CENTRAL MO WILL SERVE
AS THE INITIAL FOCUS FOR CONVECTION THIS AFTERNOON. STEEP LAPSE
RATES ALOFT AND THE AFOREMENTIONED DRY AIR COULD LEAD TO A FEW
MARGINALLY SEVERE HAIL AND WIND REPORTS WITH THE STRONGEST
STORMS...BUT AGAIN...COVERAGE SHOULD BE QUITE SPARSE.
EXPECT TO SEE MUCH OF THE CONVECTION DIMINISH WITH SUNSET TONIGHT.
A MORE ORGANIZED WAVE WILL APPROACH THE AREA TOWARD THE MORNING
HOURS TOMORROW...WITH AN ASSOCIATED UPTICK IN SHOWERS/THUNDERSTORMS
EXPECTED. THINK WE`LL SEE A FEW WAVES OF CONVECTION THROUGHOUT THE
DAY ON THURSDAY AS A 60 KT BRANCH OF THE SUBTROPICAL JET NOSES INTO
THE AREA. 0-6 KM SHEAR VALUES THURSDAY SHOULD BE IN THE 20-25 KT
RANGE...SUFFICIENT FOR AT LEAST OCCASIONAL CONVECTIVE ORGANIZATION.
INSTABILITY FORECASTS ARE A PROBLEM FOR TOMORROW...WITH VERY LOW
CONFIDENCE IN THE AMOUNT OF BREAKS IN THE CLOUDS.
OBVIOUSLY...AVAILABLE INSTABILITY WILL RISE CONSIDERABLY IF WE DO
SEE OCCASIONAL SUNSHINE DURING THE DAY. OVERALL...THINK THE SEVERE
THREAT IS LIMITED...WITH JUST AN ISOLATED WIND GUST AND/OR LARGE
HAIL REPORT EXPECTED. TEMPERATURES WILL ALSO BE TRICKY TOMORROW.
FOR NOW HAVE GONE A LITTLE ON THE COOL SIDE OF GUIDANCE (MID TO
UPPER 70S)...BUT IF A LITTLE MORE SUNSHINE THAN EXPECTED PEAKS
THROUGH THE CLOUDS...THEN READING APPROACHING OR PERHAPS EVEN
EXCEEDING 80 IN A FEW AREAS WON`T BE OUT OF THE QUESTION.
SIMILAR CONDITIONS TO TODAY ARE EXPECTED FOR FRIDAY...AS ADDITIONAL
WEAK RIPPLES PASS THROUGH IN SOUTHWEST FLOW. TEMPERATURES FOR
FRIDAY SHOULD AGAIN APPROACH THE 80 DEGREE MARK IN MANY
LOCATIONS.
BOXELL
LONG TERM (SATURDAY THROUGH WEDNESDAY)...
LATEST ROUND OF MEDIUM RANGE MODEL OUTPUT OFFERS A FEW NEW TWISTS
ON THE FORECAST. OVERALL...STILL EXPECTING AN INCREASINGLY
AMPLIFIED PATTERN WITH A DEEP TROUGH OVER THE WESTERN CONUS AND
STRONG RIDGING OVER THE EASTERN CONUS. THE CHALLENGES FOR THIS
FORECAST IS THE EXPECTED BEHAVIOR OF THE WESTERN TROUGH. THERE IS
DISAGREEMENT WITH WHETHER OR NOT THIS TROUGH WILL BECOME CUTOFF
AND LINGER TO OUR WEST (PER THE GEFS)...REMAIN AN OPEN TROUGH AND
SLOWLY TRANSLATE EASTWARD (GEM/UKMET/00Z ECMWF). GIVEN THE FIVE
WAVE PROGS IT/S REALLY DIFFICULT TO FAVOR ONE SOLUTION OVER THE
OTHER AT THIS POINT. HAVE GONE WITH A CONSENSUS OF THE MODELS FOR
THE TIME BEING UNTIL A FAVORED SOLUTION IS IDENTIFIED.
FROM A SENSIBLE WEATHER PERSPECTIVE...CONTINUED WARM WITH ISOLATED
TO WIDELY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED
OVER THE WEEKEND. AT THIS POINT...BETTER COVERAGE (RELATIVELY
SPEAKING) LOOKS TO BE ON SATURDAY AFTERNOON. SHOULD SEE A QUIETER
PERIOD SUNDAY NIGHT AND MONDAY...WITH GRADUALLY INCREASING POPS
FROM WEST TO EAST TUE/WED. WELL ABOVE AVERAGE TEMPERATURES WILL
CONTINUE INTO THE FIRST PART OF NEXT WEEK.
GAGAN
&&
.AVIATION...
FOR THE 00Z TAFS...VFR CONDITIONS WILL CHANGE TO MVFR CEILINGS
LATE TONIGHT WITH A STRATUS DECK MOVING IN. EXPECT GUSTS TO RELAX
AFTER SUNSET THIS EVENING WITH SOUTH WINDS AROUND 10 KNOTS.
INCLUDED VCTS BY LATE TOMORROW MORNING AND SOUTH WINDS CONTINUING
BETWEEN 10 TO 15 KNOTS IN THE AFTERNOON.
GRIFFIN
&&
.CLIMATE...
SPRINGFIELD (KSGF)
DAY DATE TEMP YEAR
THR 15TH 79 1983
FRI 16TH 84 1945
JOPLIN (KJLN)
DAY DATE TEMP YEAR
THR 15TH 80 1983
FRI 16TH 78 1995
ROLLA-VICHY (KVIH)
DAY DATE TEMP YEAR
THR 15TH 75 1995
FRI 16TH 78 1982
WEST PLAINS (KUNO)
DAY DATE TEMP YEAR
THR 15TH 78 1977
FRI 16TH 82 1982
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
647 PM EDT TUE MAR 13 2012
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL EXTEND WESTWARD ACROSS THE EASTERN
CAROLINAS INTO EARLY NEXT WEEK. SOUTHERLY WINDS WILL BRING WARM
TEMPERATURES. A WEAK FRONT MAY BRIEFLY REACH THE AREA WEDNESDAY
BEFORE DISSIPATING. THERE WILL BE SOME OPPORTUNITY FOR RAINFALL
INTO TONIGHT...AND THEN AGAIN DURING THE WEEKEND AS A COLD FRONT
APPROACHES THE AREA.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 6:45 PM TUESDAY...HAVE DROPPED POPS TO THE SLIGHT CHANCE
CATEGORY AND ELIMINATED QPF FOR THE EVENING HOURS. CONVECTION JUST
CANNOT GET GOING LATE THIS AFTERNOON. RADAR LOOPS SHOW SOME BRIEF
FLARE-UPS OVER OUR SC COUNTIES...THEN A FEW SCANS LATER...GONE.
WATER VAPOR LOOPS SHOW BULK OF SHORT WAVE ENERGY PASSING TO OUR
SOUTH AND WITH LOSS OF DAYTIME HEATING SEE LITTLE IN THE WAY OF
TRIGGERS FOR SIGNIFICANT CONVECTION FOR THE REMAINDER OF THE NEAR
TERM. NEXT UPDATE WILL LIKELY ELIMINATE POPS COMPLETELY. HAVE ALSO
ADJUSTED THE TEMPERATURE CURVE UPWARDS BY A FEW DEGREES FOR THE
AFTERNOON AND EVENING HOURS. LATEST OBS SHOW PLENTY OF MID 70S AND
EVEN SOME UPPER 70S WELL INLAND. PREVIOUS DISCUSSION FOLLOWS:
SHORTWAVE EVIDENT ON WV IMAGERY MOVING ACROSS THE UPSTATE OF SC IS
CREATING SOME SCATTERED SHOWERS/TSTMS WHICH ARE PUSHING EAST
TOWARDS THE ILM CWA. THIS ACTIVITY IS NOT AS WIDESPREAD AS
PREVIOUSLY ANTICIPATED...WHICH IS INTERESTING SINCE CLOUDS HAVE
BROKEN...WHICH WAS EXPECTED TO BE THE LIMITING FACTOR TO
CONVECTIVE TRIGGER. A GLANCE AT LATEST RUC SOUNDINGS INDICATE A
SUBADIABATIC LAYER BETWEEN 950MB-800MB WHICH IS LIKELY ACTING AS A
WEAK CAP TO INHIBIT SURFACE PARCELS FROM BECOMING UNSTABLE...AND
LACK OF AGITATED CU IN THE CLEAR BREAKS IS A FURTHER SIGNAL OF
THIS. APPEARS THE NAM/SREF ARE OVERDOING CONVECTIVE POTENTIAL
THROUGH TONIGHT...SO HAVE TRIMMED SPATIAL COVERAGE OF CHANCE POP.
EXPECT THE AREA OF TSTMS JUST AHEAD OF THE S/W TO PUSH EAST AND
SURVIVE TO THE COAST IN THE NEXT SEVERAL HOURS...WITH HIGH CHANCE
TSTMS FROM ALONG AND SOUTH OF A LINE FROM HVS...TO MYR.
OTHERWISE...NO SIGNIFICANT PRECIP EXPECTED TO DEVELOP...WITH ONLY
SCHC POP ACROSS NORTHERN ZONES THROUGH TONIGHT BEFORE ACTIVITY
WILL ERODE DIURNALLY.
ONE LAST S/W WILL PIVOT THROUGH TONIGHT AND A WEAK COLD FRONT
APPROACHES FROM THE NW TRAILED FROM A LOW MOVING ACROSS NEW
ENGLAND. LATEST GUIDANCE HAS SPED UP THIS FRONT JUST
SLIGHTLY...AND HAVE VEERED WINDS TO THE WEST BY MORNING WEDNESDAY.
THIS FRONT ACTS AS THE MAIN PLAYER INTO FOG/STRATUS DEVELOPMENT
OVERNIGHT. DO NOT EXPECT FULL DECOUPLING SINCE THE GRADIENT WILL
REMAIN SLIGHTLY PINCHED...AND MET/MAV WIND VALUES REFLECT THIS
WELL. AT THE SAME TIME...FORECAST SOUNDINGS DEPICT A LLJ OF AROUND
20 KTS JUST ABOVE THE SURFACE INVERSION...ALL OF THESE WOULD POINT
TOWARDS A STRATUS EVENT TONIGHT IN THE MOIST ATMOSPHERE AS OPPOSED
TO FOG. HOWEVER...MODERATELY STEEP LOW LEVEL HYDROLAPSE RATES AND
CLEARING SKY CONDITIONS FAVOR FOG...AND CROSSOVER TEMPS WILL
LIKELY BE REACHED AT MOST LOCALES. FOR THIS REASON HAVE KEPT AREAS
OF FOG TO BE CONSISTENT WITH NEIGHBORS...BUT NOT MENTIONED
WIDESPREAD FOR THE POTENTIAL OF MORE STRATUS THAN FOG. HAVE
DROPPED MINS A DEGREE ACROSS THE BOARD FOR THE SLIGHTLY FASTER
VEER IN WIND DIRECTION...WITH LOW 50S FAR NW AND MID 50S AT THE
COAST. IF STRATUS BECOMES PREDOMINANT OR DEVELOPS MORE
RAPIDLY...THESE MINS MAY BE A BIT TOO COOL.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...FAIR WEATHER EXPECTED THROUGH THE PERIOD AS
HIGH PRESSURE CONTROLS AREA WEATHER. EXPECT HIGHS EACH DAY IN THE
UPPER 70S TO LOWER 80S...PERHAPS MID 80S WELL INLAND...WITH COOLER
ON TAP NEARER THE BEACHES. LOWS EACH NIGHT WILL FALL INTO THE
MIDDLE 50S. AFTER WEDNESDAY MORNING...SKIES SHOULD BE MAINLY CLEAR
THOUGH SOME INCREASE IN CLOUDS IS POSSIBLE IN ADVANCE OF THE NEXT
SYSTEM THURSDAY NIGHT. IT IS WORTH NOTING THAT ISOLATED SHOWERS ARE
POSSIBLE ALONG THE SEA BREEZE EACH AFTERNOON BUT THE PROBABILITY OF
SHOWERS IS LOW ENOUGH THAT MENTION IN THE FORECAST IS NOT WARRANTED
AT THIS TIME.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...DECENT MODEL COHESIVENESS FRIDAY THROUGH
TUESDAY IN DEPICTING A DEVELOPING OMEGA-BLOCK PATTERN OVER THE
CONUS...WITH SUBTLE BUT IMPORTANT DIFFERENCES IN THE LONGITUDINAL
PLACEMENT OF THE OMEGA-RIDGE AXIS. THE FARTHER WEST POSITIONING
OFFERED IN THE ECMWF IMPLIES A MARITIME OR COASTAL-LOW INFLUENCE
IN OUR FORECASTS...WHEREAS THE GFS ENVELOPS THE REGION IN AN
AMPLIFYING UPPER RIDGE THROUGH THE EVOLUTION OF THE OMEGA-BLOCK
FORMATION...YIELDING WARM AND DRY. HAVE OPTED FOR SLIGHTLY LESS
AMPLIFIES SOLUTION TO THE GFS.
AT THE SURFACE...A WEAK SURFACE TROUGH WILL RESIDE ACROSS THE AREA
LATE FRIDAY THROUGH SATURDAY WITH ENOUGH MOISTURE TO WARRANT
MENTIONABLE POP VALUES. THE BOUNDARY WILL STALL SOUTH OF OUR AREA
SUNDAY ONWARD. RETURN FLOW SHOULD BRING A SLIGHT CHANCE OF SHOWERS
BY TUE. THIS PERIOD WILL BE MARKED BY ABOVE NORMAL TEMPERATURES
SINCE WE WILL BE IMPACTED BY THE RIDGE PORTION OF THE OMEGA-BLOCK.
THE COLD FRONTS WILL BE SHALLOW AND THE UPPER RIDGE WILL BE HIGHLY
AMPLIFIED OVER OR JUST WEST OF THE FORECAST AREA.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 18Z...AN APPROACHING SHORTWAVE OVER WESTERN SOUTH CAROLINA
WILL SHIFT ACROSS THE TAF SITES AND WILL EXIT THE COAST BY 00 UTC.
THERE IS A SLIGHT CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS. AT
THIS TIME FORCING IS WEAK SO HAVE ONLY GONE WITH A MENTION OF VCSH.
CLEARING AHEAD OF THE VORTICITY MAXIMUM WILL ALLOW FOR SOME HEATING
BUT WILL REMAIN WITH SHOWERS AT THIS TIME.
TONIGHT DECENT LOW LEVEL MOISTURE...AND LIGHT WINDS AT THE SURFACE
MAY INDUCE THE DEVELOPMENT OF FOG. A NEGATIVE INFLUENCE WILL BE THE
POSSIBLE DEVELOPMENT OF A LOW LEVEL JET AT 22 TO 25 KNOTS BETWEEN 1
AND 2 THOUSAND FEET AT ALL TAF SITES. THIS MAY HELP THE DEVELOPMENT
OF A STRATUS LAYER AND WILL INHIBIT DENSE FOG FROM DEVELOPING. SO AT
THIS TIME HAVE PUT THE MENTION OF IFR CEILINGS AND MVFR RESTRICTION
TO VISION STARTING AT 08 UTC.
EXTENDED OUTLOOK...MORNING IFR FOG POSSIBLE THURSDAY. VFR FRIDAY.
SHOWERS POSSIBLE LATE FRIDAY INTO SATURDAY. VFR SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6:45 PM TUESDAY...WINDS HAVE PICKED UP A TAD OVER THE WATERS
BUT ARE STILL LIGHT...IN THE 10 KNOT RANGE EXCEPT NEAR THE COAST
WHERE THE SEA BREEZE CIRCULATION IS KICKING WINDS UP INTO THE 15
KT RANGE. SEAS RIGHT AROUND 2 TO 3 FT THIS EVENING. NO CHANGES
ANTICIPATED TO GOING FORECAST. PREVIOUS DISCUSSION FOLLOWS:
VERY LIGHT GRADIENT OVER THE WATERS CONTRIBUTING TO WINDS LESS
THAN 5 KTS AT ALL BUOYS. OF COURSE WITH NO WIND...THERE IS NO
MEANINGFUL WIND CHOP...AND THE WAVE SPECTRUM IS COMPLETELY
DOMINATED BY A SE 3FT/9SEC SWELL. THIS SWELL HAS ERODED A BIT ON
ACCOUNT OF THE POSITIONING OF THE OFFSHORE RIDGE NOT ALLOWING FOR
IDEAL SE FETCH...SO WAVE GUIDANCE HAS OVERESTIMATED SEAS BY ABOUT
A FOOT THIS AFTN...AND SEAS OF ONLY 2-3 FT PRESENTLY OCCURRING.
EXPECT FAIRLY UNIFORM WIND/WAVE CONDITIONS THROUGH
NIGHTFALL...BEFORE WINDS WILL INCREASE TO AROUND 10 KTS AS
GRADIENT BECOMES PINCHED JUST SLIGHTLY AND AIR TEMPS FALL TO
VALUES BELOW OCEAN TEMPS. THIS WILL CREATE SEAS BUILDING TO 3-4 FT
BY TUESDAY MORNING.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...GENERALLY EXPECT LIGHT SW FLOW THROUGH THE
PERIOD BUT THE PRESSURE GRADIENT WILL BE WEAK ENOUGH DURING THE
PERIOD THAT THE SEA BREEZE BY DAY AND LAND BREEZE BY NIGHT COULD
BECOME DOMINANT AT TIMES. THIS COULD PRODUCE S TO SE WINDS NEAR
SHORE IN THE AFTERNOON AND MORE WESTERLY WINDS OVERNIGHT. SPEEDS
WILL REMAIN BELOW 15 KT THROUGH THE PERIOD WITH MAXIMUM SEAS OF 3 FT
EXPECTED.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...DECENT MARINE CONDITIONS FRI-SUN WITH
SUB-ADVISORY SW WINDS FRI AND SAT AHEAD OF AN INLAND SURFACE
TROUGH. THIS FEATURE WILL PUSH SOUTH OF OUR WATERS AS A COLD FRONT
SUNDAY WITH NE WIND FLOW BEHIND IT...BUT BELOW ADVISORY WIND SPEEDS
EXPECTED. IT WILL BE A BUMPY 3-4 FEET SUNDAY...AS THE NNE WIND-
WAVES CO-MINGLE WITH RESIDUAL SOUTH WAVE ENERGY. A FEW SHOWERS
POSSIBLE FRI AND SAT BUT NO TSTMS EXPECTED. PATCHY INSHORE FOG IS
POSSIBLE LATE FRIDAY AND SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK/JDW
SHORT TERM...RAN
LONG TERM...MJC
AVIATION...99
MARINE...MJC/REK/JDW/RAN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
302 PM EDT TUE MAR 13 2012
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL RIDGE WESTWARD ACROSS THE EASTERN
CAROLINAS INTO EARLY NEXT WEEK. SOUTHERLY WINDS WILL BRING WARM
TEMPERATURES. A WEAK FRONT MAY BRIEFLY REACH THE AREA WEDNESDAY
BEFORE DISSIPATING. THERE WILL BE SOME OPPORTUNITY FOR RAINFALL INTO
TONIGHT...AND THEN AGAIN DURING THE WEEKEND AS A COLD FRONT
APPROACHES THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM TUESDAY...SHORTWAVE EVIDENT ON WV IMAGERY MOVING ACROSS
THE UPSTATE OF SC IS CREATING SOME SCATTERED SHOWERS/TSTMS WHICH ARE
PUSHING EAST TOWARDS THE ILM CWA. THIS ACTIVITY IS NOT AS WIDESPREAD
AS PREVIOUSLY ANTICIPATED...WHICH IS INTERESTING SINCE CLOUDS HAVE
BROKEN...WHICH WAS EXPECTED TO BE THE LIMITING FACTOR TO CONVECTIVE
TRIGGER. A GLANCE AT LATEST RUC SOUNDINGS INDICATE A SUBADIABATIC
LAYER BETWEEN 950MB-800MB WHICH IS LIKELY ACTING AS A WEAK CAP TO
INHIBIT SURFACE PARCELS FROM BECOMING UNSTABLE...AND LACK OF
AGITATED CU IN THE CLEAR BREAKS IS A FURTHER SIGNAL OF THIS. APPEARS
THE NAM/SREF ARE OVERDOING CONVECTIVE POTENTIAL THROUGH TONIGHT...SO
HAVE TRIMMED SPATIAL COVERAGE OF CHANCE POP. EXPECT THE AREA OF
TSTMS JUST AHEAD OF THE S/W TO PUSH EAST AND SURVIVE TO THE COAST IN
THE NEXT SEVERAL HOURS...WITH HIGH CHANCE TSTMS FROM ALONG AND SOUTH
OF A LINE FROM HVS...TO MYR. OTHERWISE...NO SIGNIFICANT PRECIP
EXPECTED TO DEVELOP...WITH ONLY SCHC POP ACROSS NORTHERN ZONES
THROUGH TONIGHT BEFORE ACTIVITY WILL ERODE DIURNALLY.
ONE LAST S/W WILL PIVOT THROUGH TONIGHT AND A WEAK COLD FRONT
APPROACHES FROM THE NW TRAILED FROM A LOW MOVING ACROSS NEW ENGLAND.
LATEST GUIDANCE HAS SPED UP THIS FRONT JUST SLIGHTLY...AND HAVE
VEERED WINDS TO THE WEST BY MORNING WEDNESDAY.
THIS FRONT ACTS AS THE MAIN PLAYER INTO FOG/STRATUS DEVELOPMENT
OVERNIGHT. DO NOT EXPECT FULL DECOUPLING SINCE THE GRADIENT WILL
REMAIN SLIGHTLY PINCHED...AND MET/MAV WIND VALUES REFLECT THIS WELL.
AT THE SAME TIME...FORECAST SOUNDINGS DEPICT A LLJ OF AROUND 20 KTS
JUST ABOVE THE SURFACE INVERSION...ALL OF THESE WOULD POINT TOWARDS
A STRATUS EVENT TONIGHT IN THE MOIST ATMOSPHERE AS OPPOSED TO FOG.
HOWEVER...MODERATELY STEEP LOW LEVEL HYDROLAPSE RATES AND CLEARING
SKY CONDITIONS FAVOR FOG...AND CROSSOVER TEMPS WILL LIKELY BE
REACHED AT MOST LOCALES. FOR THIS REASON HAVE KEPT AREAS OF FOG TO
BE CONSISTENT WITH NEIGHBORS...BUT NOT MENTIONED WIDESPREAD FOR THE
POTENTIAL OF MORE STRATUS THAN FOG. HAVE DROPPED MINS A DEGREE
ACROSS THE BOARD FOR THE SLIGHTLY FASTER VEER IN WIND
DIRECTION...WITH LOW 50S FAR NW AND MID 50S AT THE COAST. IF STRATUS
BECOMES PREDOMINANT OR DEVELOPS MORE RAPIDLY...THESE MINS MAY BE A
BIT TOO COOL.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...FAIR WEATHER EXPECTED THROUGH THE PERIOD AS
HIGH PRESSURE CONTROLS AREA WEATHER. EXPECT HIGHS EACH DAY IN THE
UPPER 70S TO LOWER 80S...PERHAPS MID 80S WELL INLAND...WITH COOLER
ON TAP NEARER THE BEACHES. LOWS EACH NIGHT WILL FALL INTO THE
MIDDLE 50S. AFTER WEDNESDAY MORNING...SKIES SHOULD BE MAINLY CLEAR
THOUGH SOME INCREASE IN CLOUDS IS POSSIBLE IN ADVANCE OF THE NEXT
SYSTEM THURSDAY NIGHT. IT IS WORTH NOTING THAT ISOLATED SHOWERS ARE
POSSIBLE ALONG THE SEA BREEZE EACH AFTERNOON BUT THE PROBABILITY OF
SHOWERS IS LOW ENOUGH THAT MENTION IN THE FORECAST IS NOT WARRANTED
AT THIS TIME.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 PM TUESDAY...DECENT MODEL COHESIVENESS FRIDAY THROUGH
TUESDAY IN DEPICTING A DEVELOPING OMEGA-BLOCK PATTERN OVER THE
CONUS...WITH SUBTLE BUT IMPORTANT DIFFERENCES IN THE LONGITUDINAL
PLACEMENT OF THE OMEGA-RIDGE AXIS. THE FARTHER WEST POSITIONING
OFFERED IN THE ECMWF IMPLIES A MARITIME OR COASTAL-LOW INFLUENCE
IN OUR FORECASTS...WHEREAS THE GFS ENVELOPS THE REGION IN AN
AMPLIFYING UPPER RIDGE THROUGH THE EVOLUTION OF THE OMEGA-BLOCK
FORMATION...YIELDING WARM AND DRY. HAVE OPTED FOR SLIGHTLY LESS
AMPLIFIES SOLUTION TO THE GFS.
AT THE SURFACE...A WEAK SURFACE TROUGH WILL RESIDE ACROSS THE AREA
LATE FRIDAY THROUGH SATURDAY WITH ENOUGH MOISTURE TO WARRANT
MENTIONABLE POP VALUES. THE BOUNDARY WILL STALL SOUTH OF OUR AREA
SUNDAY ONWARD. RETURN FLOW SHOULD BRING A SLIGHT CHANCE OF SHOWERS
BY TUE. THIS PERIOD WILL BE MARKED BY ABOVE NORMAL TEMPERATURES
SINCE WE WILL BE IMPACTED BY THE RIDGE PORTION OF THE OMEGA-BLOCK.
THE COLD FRONTS WILL BE SHALLOW AND THE UPPER RIDGE WILL BE HIGHLY
AMPLIFIED OVER OR JUST WEST OF THE FORECAST AREA.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...AN APPROACHING SHORTWAVE OVER WESTERN SOUTH CAROLINA
WILL SHIFT ACROSS THE TAF SITES AND WILL EXIT THE COAST BY 00 UTC.
THERE IS A SLIGHT CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS. AT
THIS TIME FORCING IS WEAK SO HAVE ONLY GONE WITH A MENTION OF VCSH.
CLEARING AHEAD OF THE VORTICITY MAXIMUM WILL ALLOW FOR SOME HEATING
BUT WILL REMAIN WITH SHOWERS AT THIS TIME.
TONIGHT DECENT LOW LEVEL MOISTURE...AND LIGHT WINDS AT THE SURFACE
MAY INDUCE THE DEVELOPMENT OF FOG. A NEGATIVE INFLUENCE WILL BE THE
POSSIBLE DEVELOPMENT OF A LOW LEVEL JET AT 22 TO 25 KNOTS BETWEEN 1
AND 2 THOUSAND FEET AT ALL TAF SITES. THIS MAY HELP THE DEVELOPMENT
OF A STRATUS LAYER AND WILL INHIBIT DENSE FOG FROM DEVELOPING. SO AT
THIS TIME HAVE PUT THE MENTION OF IFR CEILINGS AND MVFR RESTRICTION
TO VISION STARTING AT 08 UTC.
EXTENDED OUTLOOK...MORNING IFR FOG POSSIBLE THURSDAY. VFR FRIDAY.
SHOWERS POSSIBLE LATE FRIDAY INTO SATURDAY. VFR SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM TUESDAY...VERY LIGHT GRADIENT OVER THE WATERS
CONTRIBUTING TO WINDS LESS THAN 5 KTS AT ALL BUOYS. OF COURSE WITH
NO WIND...THERE IS NO MEANINGFUL WIND CHOP...AND THE WAVE SPECTRUM
IS COMPLETELY DOMINATED BY A SE 3FT/9SEC SWELL. THIS SWELL HAS
ERODED A BIT ON ACCOUNT OF THE POSITIONING OF THE OFFSHORE RIDGE NOT
ALLOWING FOR IDEAL SE FETCH...SO WAVE GUIDANCE HAS OVERESTIMATED
SEAS BY ABOUT A FOOT THIS AFTN...AND SEAS OF ONLY 2-3 FT PRESENTLY
OCCURRING. EXPECT FAIRLY UNIFORM WIND/WAVE CONDITIONS THROUGH
NIGHTFALL...BEFORE WINDS WILL INCREASE TO AROUND 10 KTS AS GRADIENT
BECOMES PINCHED JUST SLIGHTLY AND AIR TEMPS FALL TO VALUES BELOW
OCEAN TEMPS. THIS WILL CREATE SEAS BUILDING TO 3-4 FT BY TUESDAY
MORNING.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 PM TUESDAY...GENERALLY EXPECT LIGHT SW FLOW THROUGH THE
PERIOD BUT THE PRESSURE GRADIENT WILL BE WEAK ENOUGH DURING THE
PERIOD THAT THE SEA BREEZE BY DAY AND LAND BREEZE BY NIGHT COULD
BECOME DOMINANT AT TIMES. THIS COULD PRODUCE S TO SE WINDS NEAR
SHORE IN THE AFTERNOON AND MORE WESTERLY WINDS OVERNIGHT. SPEEDS
WILL REMAIN BELOW 15 KT THROUGH THE PERIOD WITH MAXIMUM SEAS OF 3 FT
EXPECTED.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 3 PM TUESDAY...DECENT MARINE CONDITIONS FRI-SUN WITH
SUB-ADVISORY SW WINDS FRI AND SAT AHEAD OF AN INLAND SURFACE
TROUGH. THIS FEATURE WILL PUSH SOUTH OF OUR WATERS AS A COLD FRONT
SUNDAY WITH NE WIND FLOW BEHIND IT...BUT BELOW ADVISORY WIND SPEEDS
EXPECTED. IT WILL BE A BUMPY 3-4 FEET SUNDAY...AS THE NNE WIND-
WAVES CO-MINGLE WITH RESIDUAL SOUTH WAVE ENERGY. A FEW SHOWERS
POSSIBLE FRI AND SAT BUT NO TSTMS EXPECTED. PATCHY INSHORE FOG IS
POSSIBLE LATE FRIDAY AND SATURDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...31
LONG TERM...MJC
AVIATION...HAWKINS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
216 PM EDT TUE MAR 13 2012
.SYNOPSIS...
HIGH PRESSURE OFFSHORE WILL RIDGE WESTWARD ACROSS THE EASTERN
CAROLINAS INTO EARLY NEXT WEEK. SOUTHERLY WINDS WILL BRING WARM
TEMPERATURES. A WEAK FRONT MAY BRIEFLY REACH THE AREA WEDNESDAY
BEFORE DISSIPATING. THERE WILL BE SOME OPPORTUNITY FOR RAINFALL
TODAY...AND THEN AGAIN DURING THE WEEKEND AS A COLD FRONT APPROACHES
THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM TUESDAY...SHORTWAVE EVIDENT ON WV IMAGERY MOVING ACROSS
THE UPSTATE OF SC IS CREATING SOME SCATTERED SHOWERS/TSTMS WHICH ARE
PUSHING EAST TOWARDS THE ILM CWA. THIS ACTIVITY IS NOT AS WIDESPREAD
AS PREVIOUSLY ANTICIPATED...WHICH IS INTERESTING SINCE CLOUDS HAVE
BROKEN...WHICH WAS EXPECTED TO BE THE LIMITING FACTOR TO CONVECTIVE
TRIGGER. A GLANCE AT LATEST RUC SOUNDINGS INDICATE A NEARLY
ISOTHERMAL LAYER BETWEEN 950MB-800MB WHICH IS LIKELY ACTING AS A
WEAK CAP TO INHIBIT SURFACE PARCELS FROM BECOMING UNSTABLE...AND
LACK OF AGITATED CU IN THE CLEAR BREAKS IS A FURTHER SIGNAL OF THIS.
APPEARS THE NAM/SREF ARE OVERDOING CONVECTIVE POTENTIAL THROUGH
TONIGHT...SO HAVE TRIMMED SPATIAL COVERAGE OF CHANCE POP. EXPECT THE
AREA OF TSTMS JUST AHEAD OF THE S/W TO PUSH EAST AND SURVIVE TO THE
COAST IN THE NEXT SEVERAL HOURS...WITH HIGH CHANCE TSTMS FROM ALONG
AND SOUTH OF A LINE FROM HVS...TO MYR. OTHERWISE...NO SIGNIFICANT
PRECIP EXPECTED TO DEVELOP...WITH ONLY SCHC POP ACROSS NORTHERN
ZONES THROUGH TONIGHT BEFORE ACTIVITY WILL ERODE DIURNALLY.
ONE LAST S/W WILL PIVOT THROUGH TONIGHT AND A WEAK COLD FRONT
APPROACHES FROM THE NW TRAILED FROM A LOW MOVING ACROSS NEW ENGLAND.
LATEST GUIDANCE HAS SPED UP THIS FRONT JUST SLIGHTLY...AND HAVE
VEERED WINDS TO THE WEST BY MORNING WEDNESDAY.
THIS FRONT ACTS AS THE MAIN PLAYER INTO FOG/STRATUS DEVELOPMENT
OVERNIGHT. DO NOT EXPECT FULL DECOUPLING SINCE THE GRADIENT WILL
REMAIN SLIGHTLY PINCHED...AND MET/MAV WIND VALUES REFLECT THIS WELL.
AT THE SAME TIME...FORECAST SOUNDINGS DEPICT A LLJ OF AROUND 20 KTS
JUST ABOVE THE SURFACE INVERSION...ALL OF THESE WOULD POINT TOWARDS
A STRATUS EVENT TONIGHT IN THE MOIST ATMOSPHERE AS OPPOSED TO FOG.
HOWEVER...MODERATELY STEEP LOW LEVEL HYDROLAPSE RATES AND CLEARING
SKY CONDITIONS FAVOR FOG...AND CROSSOVER TEMPS WILL LIKELY BE
REACHED AT MOST LOCALES. FOR THIS REASON HAVE KEPT AREAS OF FOG TO
BE CONSISTENT WITH NEIGHBORS...BUT NOT MENTIONED WIDESPREAD FOR THE
POTENTIAL OF MORE STRATUS THAN FOG. HAVE DROPPED MINS A DEGREE
ACROSS THE BOARD FOR THE SLIGHTLY FASTER VEER IN WIND
DIRECTION...WITH LOW 50S FAR NW AND MID 50S AT THE COAST. IF STRATUS
BECOMES PREDOMINANT OR DEVELOPS MORE RAPIDLY...THESE MINS MAY BE A
BIT TOO COOL.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...DRY ADVECTION AND HEIGHT RISES BEHIND TUESDAY`S
WEAK DISTURBANCE WILL BRING A DRY AND UNSEASONABLY WARM DAY ON
WEDNESDAY. SURFACE FLOW LOOKS VERY LIGHT DUE TO DISSIPATING TROUGH
COMING THROUGH FROM THE NORTH. GIVEN THE WARMTH A STRONG SEA BREEZE
CIRCULATION SHOULD DEVELOP ALTHOUGH ITS INLAND PROGRESSION WILL BE
HINDERED SLIGHTLY BY THE OFFSHORE BOUNDARY LAYER WINDS. UPPER RIDGE
TRIES TO CONTINUE TO BUILD IN AMPLITUDE ON THURSDAY BUT IS HELD BACK
BY UPPER LOW DEEPENING OFF OF NEW ENGLAND COAST. SURFACE GRADIENT
REMAINS QUITE LIGHT AND SO BASICALLY LOOKING FOR LARGELY A REPEAT
FORECAST. AFTERNOON HIGHS WELL ABOVE CLIMO AND A COOLING SEA BREEZE
ALONG THE IMMEDIATE COAST. MAIN DIFFERENCE IS THAT THURSDAY SEA
BREEZE WILL MOVE FURTHER INLAND DUE TO LESS OF A DEFINED OFFSHORE
FLOW IN THE BL.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...UNSEASONABLE WARMTH WILL CONTINUE TO BE THE
MAIN HEADLINE OF THE LONG TERM. UPPER RIDGE ACROSS MOST OF THE GULF
OF MEXICO WHILE SURFACE HIGH PRESSURE STRUGGLES TO HAVE A
WELL-DEFINED CENTER OFF THE SOUTHEAST COAST. MODELS HAVE BEEN FAIRLY
CONSISTENT IN SHOWING A RIDGE TOPPING SET OF VORT MAXES COMING
ACROSS FRIDAY NIGHT INTO SATURDAY ACCOMPANIED BY A WEAK SURFACE
TROUGH. IT SEEMS PLAUSIBLE THAT THIS SHOULD LEAD TO SOME RAIN
CHANCES EVEN IF ONLY POPS AROUND THE LOW SIDE OF CHANCE RANGE. GFS
SHOWS THIS AS MORE OF A BONA FIDE FRONT WITH SOME SLIGHT COOLING
BEHIND IN STORE FOR THE LATTER PART OF THE LONG TERM (COOLER BUT
STILL ABOVE CLIMO). THE CANADIAN AND EC ARE NOT SO SUGGESTIVE OF
THIS SO FAIRLY SIZABLE DEVIATIONS FROM CLIMO WARMTH WILL REMAIN IN
THE FORECAST.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...AN APPROACHING SHORTWAVE OVER WESTERN SOUTH CAROLINA
WILL SHIFT ACROSS THE TAF SITES AND WILL EXIT THE COAST BY 00 UTC.
THERE IS A SLIGHT CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS. AT
THIS TIME FORCING IS WEAK SO HAVE ONLY GONE WITH A MENTION OF VCSH.
CLEARING AHEAD OF THE VORTICITY MAXIMUM WILL ALLOW FOR SOME HEATING
BUT WILL REMAIN WITH SHOWERS AT THIS TIME.
TONIGHT DECENT LOW LEVEL MOISTURE...AND LIGHT WINDS AT THE SURFACE
MAY INDUCE THE DEVELOPMENT OF FOG. A NEGATIVE INFLUENCE WILL BE THE
POSSIBLE DEVELOPMENT OF A LOW LEVEL JET AT 22 TO 25 KNOTS BETWEEN 1
AND 2 THOUSAND FEET AT ALL TAF SITES. THIS MAY HELP THE DEVELOPMENT
OF A STRATUS LAYER AND WILL INHIBIT DENSE FOG FROM DEVELOPING. SO AT
THIS TIME HAVE PUT THE MENTION OF IFR CEILINGS AND MVFR RESTRICTION
TO VISION STARTING AT 08 UTC.
EXTENDED OUTLOOK...MORNING IFR FOG POSSIBLE THURSDAY. VFR FRIDAY.
SHOWERS POSSIBLE LATE FRIDAY INTO SATURDAY. VFR SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM TUESDAY...VERY LIGHT GRADIENT OVER THE WATERS
CONTRIBUTING TO WINDS LESS THAN 5 KTS AT ALL BUOYS. OF COURSE WITH
NO WIND...THERE IS NO MEANINGFUL WIND CHOP...AND THE WAVE SPECTRUM
IS COMPLETELY DOMINATED BY A SE 3FT/9SEC SWELL. THIS SWELL HAS
ERODED A BIT ON ACCOUNT OF THE POSITIONING OF THE OFFSHORE RIDGE NOT
ALLOWING FOR IDEAL SE FETCH...SO WAVE GUIDANCE HAS OVERESTIMATED
SEAS BY ABOUT A FOOT THIS AFTN...AND SEAS OF ONLY 2-3 FT PRESENTLY
OCCURRING. EXPECT FAIRLY UNIFORM WIND/WAVE CONDITIONS THROUGH
NIGHTFALL...BEFORE WINDS WILL INCREASE TO AROUND 10 KTS AS GRADIENT
BECOMES PINCHED JUST SLIGHTLY AND AIR TEMPS FALL TO VALUES BELOW
OCEAN TEMPS. THIS WILL CREATE SEAS BUILDING TO 3-4 FT BY TUESDAY
MORNING.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM TUESDAY...WIND WILL BE LIGHT AND PREDOMINANTLY OUT OF THE
SOUTHWEST ON WEDNESDAY WITH ONLY A 2 TO 3 FT WIND WAVE EXPECTED. A
NEARSHORE SEA BREEZE WILL BE OBSERVED AND IT MAY END UP ADDING SOME
GUSTINESS BUT THE TURN TO ONSHORE DIRECTION WILL BE MORE NOTICEABLE
AS LIGHT BOUNDARY LAYER WINDS WILL FAVOR MODEST GUSTS AT BEST. WIND
DIRECTION THEN STRUGGLES TO BE WELL DEFINED BY THURSDAY AS PRESSURE
GRADIENT WEAKENS. SEAS RELATIVELY UNCHANGED.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 3 AM TUESDAY...AS WIND REMAINS LIGHT ON FRIDAY A DEFINED
SOUTHWESTERLY DIRECTION MAY GET RE-ESTABLISHED AFTER THURSDAYS
RELATIVE VARIABILITY. THIS WILL BE IN RESPONSE TO THE APPROACH OF A
TROUGH SLATED TO COME THROUGH FRIDAY NIGHT OR SATURDAY. THE VEER
ASSOC WITH THE BOUNDARY WILL DEPEND ON ITS STRENGTH BUT CURRENT
FAVORED SOLUTION KEEPS IT WEAK ENOUGH TO PRECLUDE ANY NORTHERLY
COMPONENT FROM EVER DEVELOPING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...HAWKINS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
110 PM EDT TUE MAR 13 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL CROSS THE AREA LATER LATER THIS
AFTERNOON AND EVENING...BRINGING WITH IT A CHANCE OF SHOWERS OR
ISOLATED THUNDERSTORMS. AN UPPER LEVEL RIDGE WILL BUILD INTO THE
AREA WEDNESDAY THROUGH THE REMAINDER OF THE WORK WEEK...RESULTING IN
ABOVE NORMAL TEMPERATURES THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM TUESDAY...
OVERVIEW:
IN THE UPPER LEVELS...WESTERLY FLOW ALOFT WILL PREVAIL THROUGH
TONIGHT OVER THE CAROLINAS AND MID-ATLANTIC. AN UPPER LEVEL
DISTURBANCE THAT EMANATED FROM CONVECTION ALONG THE CENTRAL GULF
COAST YESTERDAY MORNING AND THAT PROGRESSED THROUGH CENTRAL NC
OVERNIGHT WAS LOCATED IN THE EASTERN CAROLINAS THIS MORNING...AND
WILL PROGRESS OFFSHORE BY NOON. AN H3 SHORTWAVE WAS NOTED IN CENTRAL
TN AT 15Z THIS MORNING...WITH ADDITIONAL SHORTWAVE ENERGY SLIGHTLY
UPSTREAM OVER ARKANSAS AND NORTHERN MS. THE LATEST RUC INDICATES THE
CENTRAL TN SHORTWAVE WILL PROGRESS INTO THE WEST/NW PIEDMONT BETWEEN
18-21Z...AND THE AR/MS SHORTWAVE WILL PROGRESS THROUGH NORTHERN
AL/GA INTO UPSTATE SC BY 21Z. THESE FEATURES ARE PROGGED TO INTERACT
TO SOME DEGREE...PROGRESSING THROUGH CENTRAL NC TO THE COAST BY OR
SHORTLY AFTER 00-03Z THIS EVENING. IN THE LOWER LEVELS...THE
OFFSHORE RIDGE WILL CONTINUE TO WEAKEN...WITH H85 FLOW VEERING FROM
SOUTHWESTERLY TO WESTERLY BY 00Z...THEN NORTHWEST OVERNIGHT AS A
WEAK H85 TROUGH PROGRESSES THROUGH THE MID-ATLANTIC/CAROLINAS.
TODAY:
SHOWER ACTIVITY PROGRESSING EASTWARD THROUGH THE AREA AT ~25 MPH
THIS MORNING IS LIKELY BEING FORCED BY THE UPPER LEVEL DISTURBANCE
THAT PUSHED INTO THE AREA FROM THE SOUTHWEST LAST NIGHT AND WHICH IS
CURRENTLY PROGRESSING INTO EASTERN NC. SHOWER ACTIVITY SHOULD
CONTINUE TO WANE AS THE AFOREMENTIONED DISTURBANCE TRACKS EAST AWAY
FROM CENTRAL NC...AND WILL INDICATE PRECIP CHANCES LOWERING AND
ENDING FROM WEST-EAST THROUGH 16-18Z. POCKETS OF SUNSHINE WERE NOTED
ON VIS SAT IMAGERY IN THE WAKE OF SHOWER ACTIVITY WEST OF HWY 1 AT
15Z...ALTHOUGH LOW STRATUS (CEILINGS ~1000-1500 FT AGL) HAS RECENTLY
DEVELOPED/EXPANDED UPSTREAM ALONG THE I-77 CORRIDOR AND MAY HELP
LIMIT HEATING THROUGH NOON IN THE WESTERN PIEDMONT BEFORE
STRENGTHENING INSOLATION/MIXING HELP SCATTER IT OUT TO SOME DEGREE.
AT THE VERY LEAST EXPECT POCKETS OF HEATING ACROSS THE AREA THIS
AFTERNOON...MORE-SO IN THE WESTERN PIEDMONT ASSUMING THE
AFOREMENTIONED STRATUS DOES NOT LINGER LONGER THAN EXPECTED.
W/REGARD TO INSTABILITY...SFC DEWPOINTS (MID/UPPER 50S) SHOULD BE
RELATIVELY UNIFORM ACROSS THE AREA THIS AFTERNOON...ALTHOUGH TEMPS
ARE EXPECTED TO BE A FEW DEGREES WARMER AND MID-LEVEL LAPSE RATES
ARE PROGGED TO BE ~1C STEEPER IN W/NW PORTIONS OF THE AREA. AS A
RESULT...THE RELATIVE BEST INSTABILITY THIS AFTERNOON SHOULD BE IN
THE WEST/NW PIEDMONT...WHERE 500-1000 J/KG OF MLCAPE COULD BE
PRESENT. FURTHER EAST...MLCAPE VALUES MAY BE LIMITED TO ~500 J/KG.
W/REGARD TO FORCING...THE SHORTWAVE PROGRESSING INTO EASTERN TN AND
THE OTHER SHORTWAVE PROGRESSING INTO NORTHERN AL AT 15Z THIS MORNING
WILL PROGRESS INTO THE CAROLINAS THIS AFTERNOON. ALTHOUGH LOWER
LEVEL FORCING WILL BE LARGELY ABSENT TODAY...THE AFOREMENTIONED
UPPER WAVES SHOULD PROVIDE SUFFICIENT ASCENT FOR AT LEAST ISOLD
CONVECTION TO DEVELOP IN THE PRESENCE OF MARGINAL INSTABILITY AND
FAVORABLE DIURNAL TIMING. THE 00/06Z HIGH-RES WRF/NMM MODELS DO NOT
ADD MUCH CONFIDENCE TO THE CONVECTIVE FCST...SHOWING A VARIETY OF
SOLUTIONS THAT DIFFER BOTH IN COVERAGE AND IN TIME. WITH THE ABOVE
IN MIND...WILL KEEP THE PRECIP FORECAST AS IS...INDICATING A 30%
CHANCE OF SHOWERS/STORMS THROUGH 00Z...THOUGH IT IS POSSIBLE ISOLD
CONVECTION (SHOULD IT DEVELOP) COULD PERSIST INTO THE 00-03Z TIME
FRAME EAST OF HWY 1. GIVEN RELATIVELY HOMOGENEOUS THICKNESSES ACROSS
THE AREA...HIGHS WILL BE DICTATED PRIMARILY BY CLOUD COVER. EXPECT
HIGHS RANGING FROM THE MID 70S (~75F) WEST OF HWY 1 TO LOWER 70S
EAST OF I-95.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES TODAY ARE PROGGED TO BE 20-25 KT OR LESS. AS
A RESULT...EVEN IF CONVECTION DEVELOPS THIS AFTERNOON...BULK SHEAR
VALUES WILL ONLY BE MARGINALLY SUPPORTIVE OF MULTICELLULAR
ORGANIZATION. ADDITIONALLY...THE MIXED LAYER SHOULD BE RELATIVELY
SHALLOW TODAY...WITH LITTLE DCAPE/EVAP COOLING POTENTIAL...NOT TO
MENTION LOW/MID LEVEL FLOW (SFC-10 KFT) WILL BE NO MORE THAN 15-25
KT. WITH THE ABOVE IN MIND...DO NOT ANTICIPATE ANY SEVERE THREAT.
TONIGHT:
A MUCH DRIER MID/UPPER LEVEL AIRMASS WILL ADVECT INTO THE AREA VIA
WESTERLY FLOW ALOFT AFTER 00Z THIS EVENING...AND THIS SHOULD ALLOW
FOR A FAIR AMOUNT OF CLEARING FROM WEST-EAST BETWEEN 00-06Z. GIVEN
EXPECTED CLEARING AND THE PRESENCE OF A WEAK/BAGGY MSLP GRADIENT...
RADIATIONAL COOLING SHOULD ALLOW A NOCTURNAL INVERSION TO DEVELOP
WITHIN A FEW HRS AFTER SUNSET. DESPITE ADDITIONAL H3 SHORTWAVE
ENERGY EXPECTED TO DIG INTO THE AREA FROM THE N/NW OVERNIGHT...THE
COMBINATION OF DRY MID/UPPER LEVELS AND NOCTURNAL STABILIZATION WILL
PRECLUDE THE POTENTIAL FOR ANY PRECIPITATION. GIVEN NO REAL AIRMASS
CHANGE (STAGNANT GRADIENT)...EXPECT LOWS SIMILAR TO LAST NIGHT...IN
THE LOWER/MID 50S...WARMEST EAST/SE. GIVEN CALM WINDS AND RESIDUAL
BOUNDARY LAYER MOISTURE...AS LONG AS SKIES CLEAR AS EXPECTED...
WIDESPREAD FOG IS A GOOD BET TONIGHT. AREAS OF DENSE FOG OR EVEN
WIDESPREAD DENSE FOG WILL BE POSSIBLE...AND A DENSE FOG ADVISORY MAY
BE NEEDED LATE TONIGHT/WED MORNING. -VINCENT
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...
THE UPPER LEVEL RIDGE WILL BEGIN TO AMPLIFY WEDNESDAY WHILE THE
850MB HIGH BEGINS TO STRENGTHEN OVER THE SOUTHEAST US. DRY
ADIABATIC MIXING TO 850MB...WHICH SEEMS POSSIBLE WITH THE 850MB HIGH
STILL TO THE SOUTHWEST AND NORTHWESTERLY FLOW OVER THE CWA...YIELDS
HIGHS IN THE LOWER 80S. STATISTICAL GUIDANCE HAS BEEN INCHING IN
THIS DIRECTION ALSO...SO THERE IS FAIRLY GOOD CONFIDENCE THAT MOST
LOCATIONS WILL REACH 80 DEGREES. WILL FORECAST 79-82 WITH WARMEST
READINGS IN THE SOUTHEAST. -BLS
FOR WEDNESDAY NIGHT THROUGH THURSDAY NIGHT: CONTINUED DRY AND VERY
WARM. THE MID LEVEL LOW OVER SOUTHERN QUEBEC WEDNESDAY EVENING
CROSSES NEW ENGLAND AND MOVES TO JUST OFF THE CANADIAN MARITIMES BY
THURSDAY NIGHT. AS THIS LOW AND ASSOCIATED MID LEVEL TROUGH MOVE TO
OUR NORTHEAST... A MID LEVEL RIDGE AXIS SHIFTS EASTWARD OVER NC
WEDNESDAY NIGHT/THURSDAY... ENSURING CONTINUED DRY AND SINKING AIR
IN THE MID-UPPER LEVELS. THE SURFACE BACKDOOR FRONT ASSOCIATED WITH
THIS NEW ENGLAND LOW IS EXPECTED TO MOVE NO FURTHER SOUTHEAST THAN
NORTHEAST VA... WHICH WILL KEEP NC WITHIN A LIGHT/VARIABLE SURFACE
REGIME BECOMING SOUTHERLY THURSDAY. AFTER POCKETS OF DAYBREAK FOG
THURSDAY MORNING THAT SHOULD EASILY MIX OUT BY MID MORNING... THE
WEAK WARM AIR ADVECTION AND LACK OF CLOUDS ALOFT WILL ALLOW FOR
STRONG HEATING AS THICKNESSES REMAIN (AS MODELS HAVE INDICATED FOR
SEVERAL DAYS NOW) 40-50 METERS ABOVE NORMAL. LOWS 50-55 AND HIGHS
78-82. THE MID LEVEL RIDGE AXIS DROPS TO OUR SOUTHEAST THURSDAY
NIGHT AS A WEAK SOUTHERN STREAM WAVE MOVES ACROSS KY AND THE OH
VALLEY TOWARD THE CENTRAL/SRN APPALACHIANS. SLOWLY INCREASING
925-850 MB WINDS FROM WEST TO EAST ACROSS WV/VA WILL HELP SHARPEN
THE LEE TROUGH OVERNIGHT... AND THIS INCREASING LOW LEVEL MASS
CONVERGENCE AND APPROACH OF THE MID LEVEL WAVE WILL LEAD TO SKIES
BECOMING PARTLY TO MOSTLY CLOUDY WEST TO EAST. LOWS THURSDAY NIGHT
54-58 WITH ANOTHER ROUND OF PATCHY GROUND FOG POSSIBLE TOWARD DAWN.
-GIH
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 110 PM TUESDAY...
SURFACE HIGH PRESSURE ORIENTED WEST-EAST ACROSS THE NORTHERN GULF
RETREATS EAST INTO THE ATLANTIC WITH INCREASING MOISTURE RETURN INTO
THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS THURSDAY INTO FRIDAY.
INITIALLY THE BUILDING MID LEVEL RIDGE OVER THE EASTERN CONUS WILL
BLOCK THIS MOISTURE AND A VERY WARM DAY IS ON TAP THURSDAY.
THICKNESSES AND MOS GUIDANCE HAVE TRENDED UPWARDS...WITH LOW 80S NOW
WIDESPREAD AND NEAR RECORD MID 80S NOT OUT OF THE QUESTION. LOW
LEVEL MOISTURE WILL BE ON THE INCREASE THURSDAY NIGHT AS THE SURFACE
HIGH MOVES EAST ALLOWING MORE SOUTH TO SOUTHWEST FLOW. IN
ADDITION...AN UPPER WAVE MOVES ACROSS THE RIDGE AND A WEAK BACK DOOR
FRONT WILL BE SAGGING SOUTH INTO THE MID ATLANTIC. COULD SEE SOME
PATCHY LIGHT RAIN IN THE WEST LATE THURSDAY NIGHT...OTHERWISE
BECOMING MOSTLY CLOUDY AND MILD WITH LOWS IN THE MID 50S.
LONG-TERM GUIDANCE TRENDS SHOW A TENDENCY TO BE FARTHER WEST WITH
THE RIDGE AXIS ALOFT...WITH LOWER HEIGHTS OFFSHORE OVER THE WESTERN
ATLANTIC. THE ECMWF HAS TRENDED STRONGEST WITH UPPER-LEVEL LOW
PRESSURE MOVING OVER THE BROAD UPPER RIDGE...WHICH IN TURN PUSHES A
STRONGER COLD FRONT FROM THE NORTH THROUGH CENTRAL NORTH CAROLINA
EARLY IN THIS LONG-TERM PERIOD. THE GFS AND CANADIAN TREND WEAKER
AND GENERALLY SLOWER...AND THOUGH THE GFS HAS TRENDED LOWER WITH ITS
HEIGHTS ALOFT OFFSHORE...FRONTAL CONVERGENCE STILL APPEARS WEAKER
WITH WEAKER MID- AND UPPER-LEVEL FORCING THAT LINGERS LONGER INTO
THE WEEKEND.
GFSX MOS ENSEMBLE CHANCES FOR PRECIPITATION ARE CONSISTENTLY ABOVE
CLIMATOLOGY FRIDAY INTO SATURDAY...AND EVEN INTO SUNDAY...
DIMINISHING BY MONDAY AS DRIER AIR SHOULD GRADUALLY MOVE INTO
CENTRAL NORTH CAROLINA FROM THE NORTH AND NORTHEAST BEHIND ANY
SURFACE BOUNDARY. THE PATTERN OF DIMINISHING 850MB THETA-E FROM THE
NORTHEAST ON THE ECMWF DURING THE LATER PART OF THE WEEKEND APPEARS
REASONABLE...WITH MAINLY THE TIMING IN QUESTION. WILL FOCUS CHANCES
FOR SHOWERS HIGHER IN THE WESTERN PIEDMONT AND TOWARD THE VIRGINIA
BORDER FRIDAY NIGHT...WITH HIGHER CHANCES TRANSITIONING SOUTH
SATURDAY AND SATURDAY NIGHT AS THE SURFACE BOUNDARY MOVES SOUTH AND
MORE STABLE AIR GRADUALLY MOVES IN FROM THE NORTH. GIVEN SURFACE
RIDGING OVER THE SOUTHEAST STATES INTO THE EASTERN GULF...DO NOT
EXPECT ANY PERIOD TO BE A WASHOUT...WITH SCATTERED SHOWERS OR
PERIODS OF SHOWERS PRIMARILY EXPECTED. ABNORMALLY WARM THICKNESSES
AND COOLING ALOFT WITH TROUGHING COULD LEAD TO STEEP ENOUGH LAPSE
RATES TO PROVIDE FOR THUNDER...AS NOTED ON COARSE ECMWF MODEL
SOUNDINGS.
COOLER AIR WILL BE IN PLACE TUESDAY BUT THERE ARE CONSIDERABLE
DIFFERENCES IN MODELS CONCERNING SMALLER SCALE DETAILS WHICH WILL
DETERMINE SKY COVER AND THE POSSIBLITY OF SHOWERS IN THE
EAST...WHICH WILL BE NEARER IN PROXIMITY TO AN UPPER LOW OFFSHORE.
WILL HAVE A DRY FORECAST WITH A LOW PERCENTAGE OF CLOUD COVER
LEADING TO HIGHS IN THE MID 70S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 730 AM TUESDAY...
PATCHES OF LIGHT RAIN ARE MOVING ACROSS CENTRAL NC THIS MORNING AS A
SERIES OF UPPER LEVEL DISTURBANCES DRIFT ACROSS THE AREA.
CEILINGS..HOWEVER..HAVE YET TO FALL BELOW 3K FT...AND OUTSIDE OF A
HEAVIER SHOWER THIS MORNING...CEILINGS SHOULD REMAIN VFR AS HEATING
AND WEAK MIXING COMMENCE. THERE IS QUITE A BIT OF UNCERTAINTY AS TO
HOW PRECIP WILL EVOLVE TODAY...AND THUS THERE IS LOW CONFIDENCE IN
TIMING AND IMPACT AT INDIVIDUAL TERMINALS. IN GENERAL.. CEILINGS
AND VSBYS SHOULD REMAIN IN THE 2500 TO 4000FT RANGE. THE LAST OF
THE AFOREMENTIONED UPPER DISTURBANCES SHOULD CROSS THE AREA BETWEEN
15Z AND 21Z...DURING WHICH TIME THERE WILL BE A CHANCE OF ANOTHER
ROUND OF SHOWERS OR AN ISOLATED THUNDERSTORM. ALL SHOWERS/STORMS
ARE EXPECTED TO BE EAST OF KFAY/KRWI BY 21Z-00Z.
SKIES WILL CLEAR TONIGHT AND WEST-NORTHWESTERLY WINDS ARE FORECAST
TO BE LIGHT. LOW LEVEL MOISTURE WILL REMAIN HIGH HOWEVER...WHICH
SHOULD LEAD TO A GOOD CHANCE OF FOG AT ALL TERMINALS. CONFIDENCE IN
FOG DEVELOPMENT IS HIGHEST AT KRDU/KRWI/KFAY...WHERE GUIDANCE SHOWS
FOG DEVELOPING JUST AFTER MIDNIGHT.
OUTLOOK...
VFR CONDITIONS ARE EXPECTED TO PREVAIL EACH DAY...BUT A PERIOD OF
FOG/STRATUS IS POSSIBLE DURING THE MORNING HOURS. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE
TO AN UPPER-LEVEL DISTURBANCE AND WEAK SURFACE LOW PRESSURE MOVING
THROUGH THE AREA.
&&
.CLIMATE...
HERE ARE UPCOMING HIGH TEMPERATURES RECORDS...
AT RDU:
03/14: 86 IN 1990
03/15: 87 IN 1973
03/16: 86 IN 1945
AT GSO:
03/14: 82 IN 1990
03/15: 87 IN 1967
03/16: 85 IN 1945
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH/HARTFIELD
LONG TERM...DJF/MLM
AVIATION...SMITH
CLIMATE...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1131 AM EDT TUE MAR 13 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL CROSS THE AREA LATER LATER THIS
AFTERNOON AND EVENING...BRINGING WITH IT A CHANCE OF SHOWERS OR
ISOLATED THUNDERSTORMS. AN UPPER LEVEL RIDGE WILL BUILD INTO THE
AREA WEDNESDAY THROUGH THE REMAINDER OF THE WORK WEEK...RESULTING IN
ABOVE NORMAL TEMPERATURES THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM TUESDAY...
OVERVIEW:
IN THE UPPER LEVELS...WESTERLY FLOW ALOFT WILL PREVAIL THROUGH
TONIGHT OVER THE CAROLINAS AND MID-ATLANTIC. AN UPPER LEVEL
DISTURBANCE THAT EMANATED FROM CONVECTION ALONG THE CENTRAL GULF
COAST YESTERDAY MORNING AND THAT PROGRESSED THROUGH CENTRAL NC
OVERNIGHT WAS LOCATED IN THE EASTERN CAROLINAS THIS MORNING...AND
WILL PROGRESS OFFSHORE BY NOON. AN H3 SHORTWAVE WAS NOTED IN CENTRAL
TN AT 15Z THIS MORNING...WITH ADDITIONAL SHORTWAVE ENERGY SLIGHTLY
UPSTREAM OVER ARKANSAS AND NORTHERN MS. THE LATEST RUC INDICATES THE
CENTRAL TN SHORTWAVE WILL PROGRESS INTO THE WEST/NW PIEDMONT BETWEEN
18-21Z...AND THE AR/MS SHORTWAVE WILL PROGRESS THROUGH NORTHERN
AL/GA INTO UPSTATE SC BY 21Z. THESE FEATURES ARE PROGGED TO INTERACT
TO SOME DEGREE...PROGRESSING THROUGH CENTRAL NC TO THE COAST BY OR
SHORTLY AFTER 00-03Z THIS EVENING. IN THE LOWER LEVELS...THE
OFFSHORE RIDGE WILL CONTINUE TO WEAKEN...WITH H85 FLOW VEERING FROM
SOUTHWESTERLY TO WESTERLY BY 00Z...THEN NORTHWEST OVERNIGHT AS A
WEAK H85 TROUGH PROGRESSES THROUGH THE MID-ATLANTIC/CAROLINAS.
TODAY:
SHOWER ACTIVITY PROGRESSING EASTWARD THROUGH THE AREA AT ~25 MPH
THIS MORNING IS LIKELY BEING FORCED BY THE UPPER LEVEL DISTURBANCE
THAT PUSHED INTO THE AREA FROM THE SOUTHWEST LAST NIGHT AND WHICH IS
CURRENTLY PROGRESSING INTO EASTERN NC. SHOWER ACTIVITY SHOULD
CONTINUE TO WANE AS THE AFOREMENTIONED DISTURBANCE TRACKS EAST AWAY
FROM CENTRAL NC...AND WILL INDICATE PRECIP CHANCES LOWERING AND
ENDING FROM WEST-EAST THROUGH 16-18Z. POCKETS OF SUNSHINE WERE NOTED
ON VIS SAT IMAGERY IN THE WAKE OF SHOWER ACTIVITY WEST OF HWY 1 AT
15Z...ALTHOUGH LOW STRATUS (CEILINGS ~1000-1500 FT AGL) HAS RECENTLY
DEVELOPED/EXPANDED UPSTREAM ALONG THE I-77 CORRIDOR AND MAY HELP
LIMIT HEATING THROUGH NOON IN THE WESTERN PIEDMONT BEFORE
STRENGTHENING INSOLATION/MIXING HELP SCATTER IT OUT TO SOME DEGREE.
AT THE VERY LEAST EXPECT POCKETS OF HEATING ACROSS THE AREA THIS
AFTERNOON...MORE-SO IN THE WESTERN PIEDMONT ASSUMING THE
AFOREMENTIONED STRATUS DOES NOT LINGER LONGER THAN EXPECTED.
W/REGARD TO INSTABILITY...SFC DEWPOINTS (MID/UPPER 50S) SHOULD BE
RELATIVELY UNIFORM ACROSS THE AREA THIS AFTERNOON...ALTHOUGH TEMPS
ARE EXPECTED TO BE A FEW DEGREES WARMER AND MID-LEVEL LAPSE RATES
ARE PROGGED TO BE ~1C STEEPER IN W/NW PORTIONS OF THE AREA. AS A
RESULT...THE RELATIVE BEST INSTABILITY THIS AFTERNOON SHOULD BE IN
THE WEST/NW PIEDMONT...WHERE 500-1000 J/KG OF MLCAPE COULD BE
PRESENT. FURTHER EAST...MLCAPE VALUES MAY BE LIMITED TO ~500 J/KG.
W/REGARD TO FORCING...THE SHORTWAVE PROGRESSING INTO EASTERN TN AND
THE OTHER SHORTWAVE PROGRESSING INTO NORTHERN AL AT 15Z THIS MORNING
WILL PROGRESS INTO THE CAROLINAS THIS AFTERNOON. ALTHOUGH LOWER
LEVEL FORCING WILL BE LARGELY ABSENT TODAY...THE AFOREMENTIONED
UPPER WAVES SHOULD PROVIDE SUFFICIENT ASCENT FOR AT LEAST ISOLD
CONVECTION TO DEVELOP IN THE PRESENCE OF MARGINAL INSTABILITY AND
FAVORABLE DIURNAL TIMING. THE 00/06Z HIGH-RES WRF/NMM MODELS DO NOT
ADD MUCH CONFIDENCE TO THE CONVECTIVE FCST...SHOWING A VARIETY OF
SOLUTIONS THAT DIFFER BOTH IN COVERAGE AND IN TIME. WITH THE ABOVE
IN MIND...WILL KEEP THE PRECIP FORECAST AS IS...INDICATING A 30%
CHANCE OF SHOWERS/STORMS THROUGH 00Z...THOUGH IT IS POSSIBLE ISOLD
CONVECTION (SHOULD IT DEVELOP) COULD PERSIST INTO THE 00-03Z TIME
FRAME EAST OF HWY 1. GIVEN RELATIVELY HOMOGENEOUS THICKNESSES ACROSS
THE AREA...HIGHS WILL BE DICTATED PRIMARILY BY CLOUD COVER. EXPECT
HIGHS RANGING FROM THE MID 70S (~75F) WEST OF HWY 1 TO LOWER 70S
EAST OF I-95.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES TODAY ARE PROGGED TO BE 20-25 KT OR LESS. AS
A RESULT...EVEN IF CONVECTION DEVELOPS THIS AFTERNOON...BULK SHEAR
VALUES WILL ONLY BE MARGINALLY SUPPORTIVE OF MULTICELLULAR
ORGANIZATION. ADDITIONALLY...THE MIXED LAYER SHOULD BE RELATIVELY
SHALLOW TODAY...WITH LITTLE DCAPE/EVAP COOLING POTENTIAL...NOT TO
MENTION LOW/MID LEVEL FLOW (SFC-10 KFT) WILL BE NO MORE THAN 15-25
KT. WITH THE ABOVE IN MIND...DO NOT ANTICIPATE ANY SEVERE THREAT.
TONIGHT:
A MUCH DRIER MID/UPPER LEVEL AIRMASS WILL ADVECT INTO THE AREA VIA
WESTERLY FLOW ALOFT AFTER 00Z THIS EVENING...AND THIS SHOULD ALLOW
FOR A FAIR AMOUNT OF CLEARING FROM WEST-EAST BETWEEN 00-06Z. GIVEN
EXPECTED CLEARING AND THE PRESENCE OF A WEAK/BAGGY MSLP GRADIENT...
RADIATIONAL COOLING SHOULD ALLOW A NOCTURNAL INVERSION TO DEVELOP
WITHIN A FEW HRS AFTER SUNSET. DESPITE ADDITIONAL H3 SHORTWAVE
ENERGY EXPECTED TO DIG INTO THE AREA FROM THE N/NW OVERNIGHT...THE
COMBINATION OF DRY MID/UPPER LEVELS AND NOCTURNAL STABILIZATION WILL
PRECLUDE THE POTENTIAL FOR ANY PRECIPITATION. GIVEN NO REAL AIRMASS
CHANGE (STAGNANT GRADIENT)...EXPECT LOWS SIMILAR TO LAST NIGHT...IN
THE LOWER/MID 50S...WARMEST EAST/SE. GIVEN CALM WINDS AND RESIDUAL
BOUNDARY LAYER MOISTURE...AS LONG AS SKIES CLEAR AS EXPECTED...
WIDESPREAD FOG IS A GOOD BET TONIGHT. AREAS OF DENSE FOG OR EVEN
WIDESPREAD DENSE FOG WILL BE POSSIBLE...AND A DENSE FOG ADVISORY MAY
BE NEEDED LATE TONIGHT/WED MORNING. -VINCENT
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...
THE UPPER LEVEL RIDGE WILL BEGIN TO AMPLIFY WEDNESDAY WHILE THE
850MB HIGH BEGINS TO STRENGTHEN OVER THE SOUTHEAST US. DRY
ADIABATIC MIXING TO 850MB...WHICH SEEMS POSSIBLE WITH THE 850MB HIGH
STILL TO THE SOUTHWEST AND NORTHWESTERLY FLOW OVER THE CWA...YIELDS
HIGHS IN THE LOWER 80S. STATISTICAL GUIDANCE HAS BEEN INCHING IN
THIS DIRECTION ALSO...SO THERE IS FAIRLY GOOD CONFIDENCE THAT MOST
LOCATIONS WILL REACH 80 DEGREES. WILL FORECAST 79-82 WITH WARMEST
READINGS IN THE SOUTHEAST. -BLS
FOR WEDNESDAY NIGHT THROUGH THURSDAY NIGHT: CONTINUED DRY AND VERY
WARM. THE MID LEVEL LOW OVER SOUTHERN QUEBEC WEDNESDAY EVENING
CROSSES NEW ENGLAND AND MOVES TO JUST OFF THE CANADIAN MARITIMES BY
THURSDAY NIGHT. AS THIS LOW AND ASSOCIATED MID LEVEL TROUGH MOVE TO
OUR NORTHEAST... A MID LEVEL RIDGE AXIS SHIFTS EASTWARD OVER NC
WEDNESDAY NIGHT/THURSDAY... ENSURING CONTINUED DRY AND SINKING AIR
IN THE MID-UPPER LEVELS. THE SURFACE BACKDOOR FRONT ASSOCIATED WITH
THIS NEW ENGLAND LOW IS EXPECTED TO MOVE NO FURTHER SOUTHEAST THAN
NORTHEAST VA... WHICH WILL KEEP NC WITHIN A LIGHT/VARIABLE SURFACE
REGIME BECOMING SOUTHERLY THURSDAY. AFTER POCKETS OF DAYBREAK FOG
THURSDAY MORNING THAT SHOULD EASILY MIX OUT BY MID MORNING... THE
WEAK WARM AIR ADVECTION AND LACK OF CLOUDS ALOFT WILL ALLOW FOR
STRONG HEATING AS THICKNESSES REMAIN (AS MODELS HAVE INDICATED FOR
SEVERAL DAYS NOW) 40-50 METERS ABOVE NORMAL. LOWS 50-55 AND HIGHS
78-82. THE MID LEVEL RIDGE AXIS DROPS TO OUR SOUTHEAST THURSDAY
NIGHT AS A WEAK SOUTHERN STREAM WAVE MOVES ACROSS KY AND THE OH
VALLEY TOWARD THE CENTRAL/SRN APPALACHIANS. SLOWLY INCREASING
925-850 MB WINDS FROM WEST TO EAST ACROSS WV/VA WILL HELP SHARPEN
THE LEE TROUGH OVERNIGHT... AND THIS INCREASING LOW LEVEL MASS
CONVERGENCE AND APPROACH OF THE MID LEVEL WAVE WILL LEAD TO SKIES
BECOMING PARTLY TO MOSTLY CLOUDY WEST TO EAST. LOWS THURSDAY NIGHT
54-58 WITH ANOTHER ROUND OF PATCHY GROUND FOG POSSIBLE TOWARD DAWN.
-GIH
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 310 AM TUESDAY...
FOR FRIDAY THROUGH SATURDAY NIGHT: MOSTLY CLOUDY AND WARM WITH AN
IMPROVING CHANCE OF SHOWERS. AS THE AFOREMENTIONED WAVE CROSSES THE
CENTRAL/SRN APPALACHIANS FRIDAY MORNING... A NORTHERN STREAM WAVE IS
EXPECTED TO CROSS SRN ONTARIO INTO SRN QUEBEC AND EVENTUALLY
ATTEMPTS TO MERGE WITH THE SOUTHERN STREAM WAVE... CULMINATING IN A
WEAK BUT EXPANSIVE TROUGH FROM THE CANADIAN MARITIMES ALONG THE EAST
COAST BY EARLY SATURDAY... ACCOMPANIED BY A BACKDOOR SURFACE FRONT
MOVING SOUTHWARD THROUGH THE NORTHEAST AND MIDATLANTIC REGION. THE
ECMWF DEPARTS FROM THE GFS HERE WITH A FASTER NORTHERN STREAM WAVE
WHICH DIGS MORE STRONGLY TO THE SOUTHWEST OVER OH AND RESULTS IN
MUCH MORE PRECIP AS ITS CLOSED LOW DROPS THROUGH WV/VA/NRN NC
THROUGH SATURDAY NIGHT. WHILE THE ECMWF HAS FAVORED A STRONGER
SYSTEM OFF THE NORTHEAST/MIDATLANTIC FOR ITS LAST FEW RUNS... THIS
DOESN`T AGREE WITH ITS ENS MEAN... AND THE GFS HAS BEEN MORE
CONSISTENT WITH THE EVOLUTION OF THE TRAILING PORTION OF THIS MID
LEVEL TROUGH... KEEPING IT WEAKER AND JUST OFF THE COAST. FOLLOWING
THIS LATTER SOLUTION... EXPECT THE BACKDOOR FRONT TO PUSH SSE TO THE
NC/VA BORDER FRIDAY NIGHT THEN EASE SLOWLY SOUTHWARD THROUGH NC
DURING SATURDAY. REGARDING SENSIBLE WEATHER... AS MOISTURE STEADILY
INCREASES AND DEEPENS WITH THE APPROACHING MID LEVEL WAVE... EXPECT
FRIDAY MORNING SLIGHT RAIN CHANCES TO RISE TO CHANCE AND SPREAD
EASTWARD DURING FRIDAY AFTERNOON. AN ISOLATED STORM OR TWO IS
POSSIBLE... ALTHOUGH THE MOIST MID-UPPER LEVELS (PRECIP WATER RISING
TO 200-250% OF NORMAL) WILL LIMIT MID LEVEL LAPSE RATES. EXPECT THE
CHANCE OF SHOWERS TO DROP BACK DOWN WITH THE LOSS OF HEATING FRIDAY
NIGHT... BUT WITH THE HIGH MOISTURE CONTENT AND RENEWED HEATING
SATURDAY... EXPECT ANOTHER CHANCE OF SHOWERS ESPECIALLY NEAR THE
SLOW-MOVING BACKDOOR FRONTAL ZONE ACROSS THE EASTERN AND SOUTHERN
CWA SATURDAY AFTERNOON INTO THE EVENING. CONTINUED WARM DESPITE THE
CLOUDS WITH THICKNESSES HOLDING WELL ABOVE NORMAL. HIGHS BOTH DAYS
IN THE MID-UPPER 70S. LOWS 57-60 FRIDAY NIGHT AND 54-58 SATURDAY
NIGHT AS HIGH PRESSURE BEGINS TO NOSE INTO NC FROM THE NNE.
FOR SUNDAY/MONDAY: DEEP MID LEVEL LONGWAVE TROUGHING DIGS OVER THE
WEST COAST AND ROCKIES... WHICH SERVES TO BUILD UP THE RIDGE OVER
THE EASTERN U.S.... POTENTIALLY LEADING TO DEVELOPMENT OF AN OMEGA
BLOCK OVER THE GREAT LAKES AND INTERIOR NORTHEAST BY MONDAY. SURFACE
HIGH PRESSURE INITIALLY CENTERED OVER THE NEW ENGLAND COAST SLIDES
SOUTHWARD JUST OFF THE MIDATLANTIC COAST WHILE EXTENDING THROUGH NC.
HINTS WITHIN THE GFS AND ECMWF OF A LINGERING WEAK SHEAR ZONE OVER
THE CAROLINAS (SSE OF THE BLOCK) AND POTENTIAL LOW LEVEL EASTERLY
FLOW OFF THE ATLANTIC MAY LEAD TO PATCHY SHOWERS OVER NC IN THIS
TIME FRAME... BUT CONFIDENCE AT THIS RANGE IS SUFFICIENTLY LOW TO
KEEP THE FORECAST DRY. THICKNESSES DROP WITHIN THE SURFACE RIDGE BUT
REMAIN ABOVE SEASONAL NORMALS. EXPECT HIGHS CLOSE TO 70 AND LOWS IN
THE 40S. -GIH
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 730 AM TUESDAY...
PATCHES OF LIGHT RAIN ARE MOVING ACROSS CENTRAL NC THIS MORNING AS A
SERIES OF UPPER LEVEL DISTURBANCES DRIFT ACROSS THE AREA.
CEILINGS..HOWEVER..HAVE YET TO FALL BELOW 3K FT...AND OUTSIDE OF A
HEAVIER SHOWER THIS MORNING...CEILINGS SHOULD REMAIN VFR AS HEATING
AND WEAK MIXING COMMENCE. THERE IS QUITE A BIT OF UNCERTAINTY AS TO
HOW PRECIP WILL EVOLVE TODAY...AND THUS THERE IS LOW CONFIDENCE IN
TIMING AND IMPACT AT INDIVIDUAL TERMINALS. IN GENERAL.. CEILINGS
AND VSBYS SHOULD REMAIN IN THE 2500 TO 4000FT RANGE. THE LAST OF
THE AFOREMENTIONED UPPER DISTURBANCES SHOULD CROSS THE AREA BETWEEN
15Z AND 21Z...DURING WHICH TIME THERE WILL BE A CHANCE OF ANOTHER
ROUND OF SHOWERS OR AN ISOLATED THUNDERSTORM. ALL SHOWERS/STORMS
ARE EXPECTED TO BE EAST OF KFAY/KRWI BY 21Z-00Z.
SKIES WILL CLEAR TONIGHT AND WEST-NORTHWESTERLY WINDS ARE FORECAST
TO BE LIGHT. LOW LEVEL MOISTURE WILL REMAIN HIGH HOWEVER...WHICH
SHOULD LEAD TO A GOOD CHANCE OF FOG AT ALL TERMINALS. CONFIDENCE IN
FOG DEVELOPMENT IS HIGHEST AT KRDU/KRWI/KFAY...WHERE GUIDANCE SHOWS
FOG DEVELOPING JUST AFTER MIDNIGHT.
OUTLOOK...
VFR CONDITIONS ARE EXPECTED TO PREVAIL EACH DAY...BUT A PERIOD OF
FOG/STRATUS IS POSSIBLE DURING THE MORNING HOURS. SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE FRIDAY AFTERNOON INTO SATURDAY DUE
TO AN UPPER-LEVEL DISTURBANCE AND WEAK SURFACE LOW PRESSURE MOVING
THROUGH THE AREA.
&&
.CLIMATE...
HERE ARE UPCOMING HIGH TEMPERATURES RECORDS...
AT RDU:
03/14: 86 IN 1990
03/15: 87 IN 1973
03/16: 86 IN 1945
AT GSO:
03/14: 82 IN 1990
03/15: 87 IN 1967
03/16: 85 IN 1945
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...SMITH/HARTFIELD
LONG TERM...HARTFIELD
AVIATION...SMITH
CLIMATE...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
200 AM EDT TUE MAR 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO LINGER OFFSHORE...AND EXTEND OVER
MUCH OF THE REGION...FOR A GOOD PART OF THE WORK WEEK. AN UPPER
LEVEL DISTURBANCE WILL CROSS THE AREA LATER TODAY...BRINGING A
CHANCE OF SHOWERS TO THE REGION. TEMPERATURES SHOULD BE WELL ABOVE
NORMAL AT LEAST THROUGH NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM MONDAY...
PRECIP JUST TO THE WEST OF THE FORECAST AREA SEEMS TO BE DRIVEN
MOSTLY BY A MID-LEVEL VORT MAX THAT MOST LIKELY DEVELOPED FROM THE
DEEP CONVECTION THAT OCCURRED ACROSS THE LA/MS GULF COAST REGION
THIS MORNING. THE LATEST RUC DATA...AS WELL AS OTHER MODELS...HAVE
PICKED THIS FEATURE UP RATHER WELL AND SHOWS IT PROGRESSING THROUGH
CENTRAL NC OVERNIGHT. IT APPEARS THE DPVA ASSOCIATED WITH THIS
FEATURE WILL PROVIDE ENOUGH FORCING AND DESPITE THE POOR
THERMODYNAMICS...SCATTERED SHOWERS WILL BE POSSIBLE. AS SUCH...MANY
OF THE LATEST HIGH RES SIMULATED REFLECTIVITY DATA (WRF NMM, WRF
ARW, HRRR, AMONG OTHERS) SHOW AN AREA OF LIGHT TO MODERATE PRECIP
MOVING THROUGH THE FORECAST AREA FROM WEST TO EAST OVERNIGHT AND
INTO TUESDAY MORNING...BEGINNING AROUND 03-06Z ACROSS THE WEST.
THEREFORE...WENT AHEAD AND INCREASED POPS TO HIGH END CHANCE ACROSS
THE ENTIRE FORECAST AREA OVERNIGHT. AT THIS TIME...IT APPEARS LITTLE
TO NO INSTABILITY WILL BE PRESENT DURING THE OVERNIGHT HOURS AND
THEREFORE...THUNDER SHOULD NOT BE A THREAT. ANOTHER SHORTWAVE WILL
APPROACH FROM THE WEST BY EARLY TUESDAY WHICH MAY ALSO ENHANCE THE
FORCING OVER THE AREA...BUT AT THIS TIME IT APPEARS THE BEST FORCING
ASSOCIATED WITH THIS WAVE WILL OCCUR AFTER SUNRISE (SEE SHORT TERM
DISCUSSION BELOW FOR MORE DETAILS). WITH MOSTLY CLOUDY OR OVERCAST
SKIES AND THE INCREASE IN LOW LEVEL MOISTURE...AM EXPECTING WARMER
OVERNIGHT LOWS TONIGHT...GENERALLY IN THE LOW TO MID 50S.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 330 PM MONDAY...
TUESDAY:
AN AMPLIFYING SHORTWAVE IS EXPECTED TO PROGRESS EASTWARD ACROSS THE
CAROLINAS DURING THE DAY TUE...THOUGH THE EXACT TIMING REMAINS
SOMEWHAT UNCERTAIN. IN THE LOWER LEVELS...A PIEDMONT TROUGH DURING
IS PROGGED TO DEVELOP DURING PEAK HEATING. OTHERWISE...LIFT WILL BE
CONFINED TO VERY WEAK/BROAD LOW-LEVEL WARM ADVECTION AND MID-LEVEL
HEIGHT FALLS. W/REGARD TO THERMODYNAMICS...DESTABILIZATION WILL
LIKELY BE HAMPERED BY PERVASIVE CLOUD COVER THROUGH MUCH OF THE
DAY...PARTICULARLY EAST OF HIGHWAY 1. SOME CLEARING IS EXPECTED IN
THE WEST/NW PIEDMONT BY ~18Z IN THE PRESENCE OF A CONTINUED MOIST
BOUNDARY LAYER...AND INSTABILITY COULD ACTUALLY BE MORE FAVORABLE
WEST OF HWY 1. HOWEVER...SIGNIFICANT DRYING ALOFT IS ALSO EXPECTED
AS A MUCH DRIER MID/UPPER LEVEL AIRMASS ADVECTS INTO WESTERN
PORTIONS OF THE STATE TUE AFTERNOON...AND DRY AIR ENTRAINMENT MAY
OFFSET OR COMPLETELY NEGATE THE BENEFIT OF BETTER INSOLATION.
REGARDLESS...WITH WEAK MID-LEVEL LAPSE RATES OVER MOST OF THE AREA
(ASIDE FROM WEST/NW PIEDMONT) DURING PEAK HEATING...MLCAPE VALUES
WILL LIKELY NOT EXCEED 250-500 J/KG. WITH THE ABOVE IN MIND...EXPECT
SUFFICIENT FORCING AND INSTABILITY TO WARRANT AT LEAST A LOW CHANCE
(20-30%) OF SHOWERS/ STORMS...WITH THE BEST CHANCE OF THUNDER EAST
OF HIGHWAY 1. HOWEVER...IF FORCING ASSOC/W THE UPPER LEVEL WAVE IS
STRONG ENOUGH TO OVERCOME THE SIGNIFICANT AMOUNT OF DRY AIR ALOFT
PROGGED IN THE WEST/NW PIEDMONT...THUNDER WILL BE POSSIBLE THERE AS
WELL. GIVEN MARGINAL INSTABILITY...0-6 KM BULK SHEAR VALUES NO
HIGHER THAN 20-25 KT (BARELY SUPPORTIVE OF MULTICELLULAR
CONVECTION)...AND A RELATIVELY SHALLOW MIXED LAYER WITH LITTLE
POTENTIAL FOR EVAPORATIVELY ENHANCED DOWNDRAFTS...DO NOT ANTICIPATE
A SEVERE THREAT WITH ANY CONVECTION. EXPECT HIGHS ON TUE TO RANGE
FROM THE UPPER 60S/LOWER 70S IN THE EAST TO THE LOWER/MID 70S IN THE
WEST.
TUESDAY NIGHT:
SUBSIDENCE AND SHORTWAVE RIDGING BUILDING INTO THE AREA IN THE WAKE
OF THE SHORTWAVE SHOULD RESULT IN MOSTLY CLEAR SKIES TUE NIGHT.
GIVEN A WEAK/BAGGY MSLP GRADIENT AND THE CONTINUED PRESENCE OF A
MOIST BOUNDARY LAYER...ANTICIPATE A POTENTIAL FOR FOG ACROSS THE
AREA 06-12Z WED MORNING...ESPECIALLY IN AREAS THAT RECEIVE RAINFALL
DURING THE DAY TUE. EXPECT LOWS IN THE LOWER/MID 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 230 PM MONDAY...
AS SURFACE SYSTEM MOVES OFFSHORE EARLY WEDNESDAY...WARM AIR WILL BE
SPREADING NORTH DUE TO SUBTROPICAL RIDGING INTO THE SOUTHERN PLAINS
AND WESTERN GULF STATES. HIGHS WEDNESDAY WILL BE 15 TO 20 DEGREES
ABOVE NORMAL...UPPER 70S OVER MOST OF THE AREA. MOISTURE WILL BE
BUILDING NORTH INTO THE TENNESSEE VALLEY AND POOLING ON THE WESTERN
SLOPES AS THE RIDGE HOLDS TIGHT THROUGH THURSDAY...INSTABILITY WILL
BE MINIMAL AND CAPPED...PROVIDING ANOTHER WARM DRY DAY WITH HIGHS IN
THE UPPER 70S TO LOWER 80S AFTER MILD MORNING LOWS IN THE LOWER 50S.
A MID LEVEL WAVE ORIGINATING IN THE SOUTHERN PLAINS WILL BE
DAMPENING THE RIDGE AMPLITUDE WITH WEAK SURFACE HIGH PRESSURE
SHIFTING OFFSHORE. THIS WILL PRODUCE A SLIGHT CHANCE OF SHOWERS
THURSDAY NIGHT...WITH A LITTLE BETTER CHANCES ON FRIDAY AS A WEAK
SURFACE FRONT EDGES VERY SLOWLY SOUTH AND EAST INTO THE MID ATLANTIC
REGION. PROGGED INSTABILITY IS SUFFICIENT FOR THUNDER GIVEN THE LOW
LEVEL FORCING AS HIGHS FRIDAY WILL STILL BE ON THE WARM SIDE...MID
TO UPPER 70S.
THE SURFACE FRONT WILL SAG FURTHER SOUTH ON SATURDAY AS LOW PRESSURE
AREA DEVELOPS OFF THE MID ATLANTIC COAST...WILL MAINTAIN SLIGHT
CHANCE TO CHANCE POPS ACROSS THE AREA THROUGH SATURDAY...AGAIN WITH
A CHANCE OF THUNDER GIVEN THE WARM AIRMASS AND POTENTIAL FOR THE
FRONT TO STALL OVER THE AREA. HIGHS WILL STILL BE IN THE MID TO
UPPER 70S.
THE FRONTS WILL BE SHOVED SOUTH OF THE AREA...SATURDAY NIGHT OR
SUNDAY AND WILL MAINTAIN SLIGHT CHANCES TO COVER THE TIMING
UNCERTAINTY. HIGH PRESSURE WILL WEDGE DOWN THE COAST SUNDAY/MONDAY
AND WILL TAPER OFF THE POPS SUNDAY NIGHT AND LEAVE MONDAY DRY FOR
NOW. HIGHS SUNDAY WILL BE IN THE LOW TO MID 70S WITH COOLER TEMPS IN
THE NORTHEAST WITH LINGERING CLOUD COVERAGE AND COOL AIR WEDGING
IN...WITH HIGHS ON MONDAY A TOUCH COOLER...LOWER 70S ACROSS THE
AREA.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 200 AM TUESDAY...
LIGHT RAIN IS MOVING FROM KINT/KGSO TO JUST NORTH OF KRDU/KRWI...BUT
THE RAIN HAS BEEN LIGHT AND CEILINGS HAVE REMAINED ABOVE 3K FT.
MOST OBSERVING SITES OVER THE WESTERN PIEDMONT ARE STILL REPORTING
3-4K FT CEILINGS...SO IT IS UNCERTAIN AT THIS TIME HOW LOW CEILINGS
WILL GET BEFORE SUNRISE. A PERIOD OF MVFR CONDITIONS WILL STILL BE
REFLECTED IN THE CURRENT TAF. IF CEILINGS DO FALL TO MVFR...THEY
SHOULD HOLD RELATIVELY CLOSE TO 3K FT THROUGH THIS AFTERNOON AS LOW
LEVEL MOISTURE REMAINS HIGH AND MIXING IS SHALLOW. AN UPPER LEVEL
DISTURBANCE WILL CROSS THE AREA FROM WEST TO EAST THIS AFTERNOON
AND MAY SPARK A FEW ISOLATED SHOWERS OR STORMS....MAINLY OVER THE
WESTERN PIEDMONT. HOWEVER... CONFIDENCE IN TIMING AND LOCATION IS
MUCH TOO LOW FOR MENTION IN THE CURRENT TAF. CLEARING SKIES AFTER
00Z AND LIGHT WINDS WILL PROMOTE FOG DEVELOP TONIGHT...MOST LIKELY
AFTER 06Z.
BEYOND THE 00Z VALID TAF PERIOD...VFR CONDITIONS ARE EXPECTED TO
PREVAIL EACH DAY...BUT A PERIOD OF FOG/STRATUS IS POSSIBLE DURING
THE MORNING HOURS. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE FRIDAY
AFTERNOON INTO SATURDAY DUE TO AN UPPER-LEVEL DISTURBANCE AND WEAK
SURFACE LOW PRESSURE MOVING THROUGH THE AREA.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...KRR
SHORT TERM...VINCENT
LONG TERM...MLM
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1030 AM CDT TUE MAR 13 2012
.DISCUSSION...
MADE ONLY A FEW MINOR TWEAKS TO THE GOING FORECAST AS TODAY
CONTINUES TO BE ON TRACK FOR A WARM DAY WITH BREEZY WINDS IN THE
AFTERNOON. INVERSION HAS YET TO FULLY MIX OUT SO WINDS HAVE BEEN
FAIRLY LIGHT SO FAR BUT WITH THE PRESSURE GRADIENT INCREASING THIS
AFTERNOON THEY SHOULD COME UP INTO THE 15 TO 25 KT RANGE. TEMPS
CONTINUE TO BE ON TRACK TO CLIMB INTO THE UPPER 50S AND LOW
60S...SO ONLY ADJUSTED A BIT TO FIT CURRENT HOURLY TRENDS.
INCREASED CLOUDS JUST A BIT AS CIRRUS MOVES IN FROM THE
WEST...ALTHOUGH IT WILL BE THIN AND PLENTY OF SUN SHOULD STILL GET
THROUGH.
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE. SOUTHEAST WINDS WILL PICK UP INTO
THE 15 TO 20 KT RANGE WITH GUSTS UP TO 25 KTS.
&&
.PREV DISCUSSION... /ISSUED 345 AM CDT TUE MAR 13 2012/
SHORT TERM...
RELATIVELY QUIET PERIOD AS STRONG WAVE CRASHES PAC NORTHWEST THEN
MOVES INTO SASKATCHEWAN TONIGHT. THE RESULTANT LOW PRESSURE
GRADIENT WILL TIGHTEN UP AND MAKE IT SOMEWHAT BREEZY TODAY.
BETWEEN YESTERDAYS RAIN AND RECENT WARM TEMPERATURES SNOW PACK IS
ALL BUT GONE...SO WITH PLENTY OF SOLAR EXPECT ANOTHER WARM DAY.
MODELS IN DECENT AGREEMENT WITH WARM AIR MOVING NORTH TODAY. TODAYS
RECORD HIGH FOR GFK IS 51F AND FGF IS 55F. HAVE NEAR 60F IN GRIDS
SO EXPECT RECORDS TO FALL AGAIN. FAR IS 64 SO WILL BE CLOSE THERE.
BOUNDARY LAYER WINDS CRANK UP TO 20-25 KTS WITH 850 WINDS TO 40KTS
IN NAM AND GFS. LOWER LAYERS FAIRLY STABLE AS COOLER AIR RETREATS
AND DIRECTIONAL COMPONENT NOT OPTIMAL...SO EXPECT GUSTS TO 30 KTS
WEST OF VALLEY IN FAVORED HIGH TERRAIN. ON-LINE VERSION HRRR HAD
BEEN CONSISTENT IN GUSTS TO 35 KNOTS KABC TO KDVL...WITH LATEST
RUNS BACKING OFF. HAVE NEAR 30 KT GUSTS IN GRIDS ALONG WEST
VALLEY SO DO NOT ANTICIPATE WIND ADVISORY ATTM.
WINDS DIMINISH TONIGHT AS TROUGH REACHES DVL BASIN AROUND 06Z AND
THERMAL RIDGE MOVES INTO RRV. DRY AIR...CLEAR SKIES AND WARM AIR
ALOFT...HAVE UPPED MINS DUE TO THE WARMER AIR ALOFT KEEPING
TEMPERATURES A BIT HIGHER. WIND SHIFT PASSES AROUND SUNRISE
WEDNESDAY. WITH ONLY SLIGHT COOLING...ABOUT 4C TO 6C...EXPECT ONLY A
FEW DEGREES COOLER WEDNESDAY. THIS MAY WELL KEEP US FROM HAVING
ANOTHER RECORD WARM DAY.
SURFACE HIGH SETTLES OVER VALLEY WEDNESDAY NIGHT...WITH MAINLY
CLEAR SKIES AND CALM WINDS BY THURSDAY MORNING. DUE TO LOSS OF
SNOW...WET SOILS AND A BIT MORE CLOUD COVER KEPT MINS ABOVE 32F
MOST AREAS. COULD BE FOG THURSDAY MORN BUT WILL ASSESS THAT
POTENTIAL LATER. RETREATING HIGH AND FAIR AMOUNT OF SOLAR AGAIN
SO EXPECT ANOTHER UNSEASONALLY WARM DAY.
LONG TERM (FRIDAY-MONDAY)...ENSEMBLES AND OPERATIONAL MODELS IN
AGREEMENT WITH DEVELOPING EASTERN CONUS RIDGE AND WESTERN CONUS
TROUGH. AS THIS PATTERN DEVELOPS THERE WILL LIKELY BE A SURGE OF
MOISTURE/INSTABILITY BY SUNDAY. NEIGHBORING OFFICES DECIDED THAT A
DRY FORECAST WOULD BE BEST THROUGH SUNDAY NIGHT GIVEN NO STRONG
FORCING MECHANISM REPRESENTED BY THE MODELS. ALTHOUGH ISOLATED
THUNDER APPEARS POSSIBLE...FOLLOWED WITH THE NEIGHBORS. ON
MONDAY...GFS IS A BIT FURTHER EAST WITH OVERALL PATTERN COMPARED
WITH THE ECMWF. GFS PLACES A FRONTAL BOUNDARY THROUGH THE FA (WET)
WHILE THE ECMWF HAS UPPER RIDGING (DRY). KEPT THE THUNDER CHANCES IN
THE FORECAST FOR MONDAY. TEMPERATURES WILL CONTINUE ABOVE NORMAL.
HYDROLOGY...
WARM TEMPERATURES THE PAST FEW DAYS HAVE ALL BUT ELIMINATED THE
SNOW PACK ACROSS THE REGION. AS A RESULT MINOR RISES HAVE BEEN
SHOWING UP ON AREA RIVERS. MONDAYS RAINFALL TOTALS...BASED ON
REPORTS AND 88D ESTIMATES...WERE GENERALLY LESS THAN ONE HALF
INCH. ISOLATED AMOUNTS UP TO ONE INCH IN THE LOWER SHEYENNE AND
UPPER SNAKE BASED ON THE 88D WILL NEED TO BE VERIFIED. WITH THE
WARM TEMPERATURES FORECAST THIS WEEK ABOUT THE ONLY SNOW THAT WILL
BE LEFT SHOULD BE IN TOWNS AND SHELTERED AREAS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
345 AM CDT TUE MAR 13 2012
.SHORT TERM...
RELATIVELY QUIET PERIOD AS STRONG WAVE CRASHES PAC NORTHWEST THEN
MOVES INTO SASKATCHEWAN TONIGHT. THE RESULTANT LOW PRESSURE
GRADIENT WILL TIGHTEN UP AND MAKE IT SOMEWHAT BREEZY TODAY.
BETWEEN YESTERDAYS RAIN AND RECENT WARM TEMPERATURES SNOW PACK IS
ALL BUT GONE...SO WITH PLENTY OF SOLAR EXPECT ANOTHER WARM DAY.
MODELS IN DECENT AGREEMENT WITH WARM AIR MOVING NORTH TODAY. TODAYS
RECORD HIGH FOR GFK IS 51F AND FGF IS 55F. HAVE NEAR 60F IN GRIDS
SO EXPECT RECORDS TO FALL AGAIN. FAR IS 64 SO WILL BE CLOSE THERE.
BOUNDARY LAYER WINDS CRANK UP TO 20-25 KTS WITH 850 WINDS TO 40KTS
IN NAM AND GFS. LOWER LAYERS FAIRLY STABLE AS COOLER AIR RETREATS
AND DIRECTIONAL COMPONENT NOT OPTIMAL...SO EXPECT GUSTS TO 30 KTS
WEST OF VALLEY IN FAVORED HIGH TERRAIN. ON-LINE VERSION HRRR HAD
BEEN CONSISTENT IN GUSTS TO 35 KNOTS KABC TO KDVL...WITH LATEST
RUNS BACKING OFF. HAVE NEAR 30 KT GUSTS IN GRIDS ALONG WEST
VALLEY SO DO NOT ANTICIPATE WIND ADVISORY ATTM.
WINDS DIMINISH TONIGHT AS TROUGH REACHES DVL BASIN AROUND 06Z AND
THERMAL RIDGE MOVES INTO RRV. DRY AIR...CLEAR SKIES AND WARM AIR
ALOFT...HAVE UPPED MINS DUE TO THE WARMER AIR ALOFT KEEPING
TEMPERATURES A BIT HIGHER. WIND SHIFT PASSES AROUND SUNRISE
WEDNESDAY. WITH ONLY SLIGHT COOLING...ABOUT 4C TO 6C...EXPECT ONLY A
FEW DEGREES COOLER WEDNESDAY. THIS MAY WELL KEEP US FROM HAVING
ANOTHER RECORD WARM DAY.
SURFACE HIGH SETTLES OVER VALLEY WEDNESDAY NIGHT...WITH MAINLY
CLEAR SKIES AND CALM WINDS BY THURSDAY MORNING. DUE TO LOSS OF
SNOW...WET SOILS AND A BIT MORE CLOUD COVER KEPT MINS ABOVE 32F
MOST AREAS. COULD BE FOG THURSDAY MORN BUT WILL ASSESS THAT
POTENTIAL LATER. RETREATING HIGH AND FAIR AMOUNT OF SOLAR AGAIN
SO EXPECT ANOTHER UNSEASONALLY WARM DAY.
.LONG TERM (FRIDAY-MONDAY)...ENSEMBLES AND OPERATIONAL MODELS IN
AGREEMENT WITH DEVELOPING EASTERN CONUS RIDGE AND WESTERN CONUS
TROUGH. AS THIS PATTERN DEVELOPS THERE WILL LIKELY BE A SURGE OF
MOISTURE/INSTABILITY BY SUNDAY. NEIGHBORING OFFICES DECIDED THAT A
DRY FORECAST WOULD BE BEST THROUGH SUNDAY NIGHT GIVEN NO STRONG
FORCING MECHANISM REPRESENTED BY THE MODELS. ALTHOUGH ISOLATED
THUNDER APPEARS POSSIBLE...FOLLOWED WITH THE NEIGHBORS. ON
MONDAY...GFS IS A BIT FURTHER EAST WITH OVERALL PATTERN COMPARED
WITH THE ECMWF. GFS PLACES A FRONTAL BOUNDARY THROUGH THE FA (WET)
WHILE THE ECMWF HAS UPPER RIDGING (DRY). KEPT THE THUNDER CHANCES IN
THE FORECAST FOR MONDAY. TEMPERATURES WILL CONTINUE ABOVE NORMAL.
&&
.AVIATION...
SO FAR...BR HAS YET TO DEVELOP EAST OF VALLEY AS WINDS STAYING UP
JUST ENOUGH. IF IT DOES DEVELOP SHOULD DISSIPATE QUICKLY...SO DO
NOT PLAN ON PUTTING IT IN UPDATES. WIND GUSTS TO NEAR 30 KTS
POSSIBLE KDVL AND 25 KTS KFAR/KGFK 17Z-21Z. SLIGHTLY LOWER
EXPECTED EAST OF VALLEY...BUT WILL NEED TO MONITOR DEPENDENT ON
EXTENT OF MIXING.
&&
.HYDROLOGY...
WARM TEMPERATURES THE PAST FEW DAYS HAVE ALL BUT ELIMINATED THE
SNOW PACK ACROSS THE REGION. AS A RESULT MINOR RISES HAVE BEEN
SHOWING UP ON AREA RIVERS. MONDAYS RAINFALL TOTALS...BASED ON
REPORTS AND 88D ESTIMATES...WERE GENERALLY LESS THAN ONE HALF
INCH. ISOLATED AMOUNTS UP TO ONE INCH IN THE LOWER SHEYENNE AND
UPPER SNAKE BASED ON THE 88D WILL NEED TO BE VERIFIED. WITH THE
WARM TEMPERATURES FORECAST THIS WEEK ABOUT THE ONLY SNOW THAT WILL
BE LEFT SHOULD BE IN TOWNS AND SHELTERED AREAS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
EWENS/TG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
144 PM EDT TUE MAR 13 2012
.SYNOPSIS...
SUBTROPICAL HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATHER THROUGH
NEXT WEEKEND PROVIDING MUCH ABOVE NORMAL TEMPERATURES. AN INCREASE
IN MOISTURE WITH A FEW MINOR DISTURBANCES WILL RESULT IN AFTERNOON
AND EVENING SHOWERS AND THUNDERSTORMS AT THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM...A CHANNELED VORTMAX WAS ANALYZED ON THE WATER VAPOR
AND RUC 500MB SFC OVR CENTRAL TN...TRACKING THRU QUASI-ZONAL FLOW.
SCATTERED SHOWERS AND A COUPLE OF ISOLD TSTMS WERE BEING TRIGGERED
BY THE ASSOCIATED DPVA ACRS ERN TN/GA. THIS ACTIVITY LOOKS TO REMAIN
ISOLD AND PROBABLY ON A WEAKENING TREND AS IT ENTERS THE CWFA THIS
MORNING...AS SPC MESOANALYSIS SHOWS MUCAPES <500 J/KG IN THE
ENVIRONMENT THE CONVECTION IS MOVING. AS FOR CONVECTION THIS
AFTN...GUIDANCE STILL RATHER SUBDUED DESPITE DESTABILIZATION TO OVER
1500 J/KG AND THE VORTMAX STILL NOT THRU THE AREA BY PEAK HEATING.
ONLY THE 4 KM NCEP WRF HAS ANYTHING MORE THAN A STRAY STORM THIS
AFTN ACRS THE CWFA. BUT I AM GOING TO LEAVE THE LOW-END
CHC/SCATTERED WORDING FOR THE PIEDMONT DUE TO THE TIMING OF THE
VORTMAX FOR NOW. OTHERWISE...ONLY MINOR TWEAKS WERE MADE FOR THE
TODAY PERIOD.
PREVIOUS DISCUSSION...
AT 3 AM EDT TUESDAY...AN UPPER TROUGH AXIS WILL PROGRESS FROM THE OH
AND TN VALLEYS TO THE APPALACHIANS TODAY. A SHORTWAVE MOVING THROUGH
THIS TROUGH WILL CROSS OUR AREA AT MIDDAY. MOISTURE AHEAD OF THE
REMNANTS OF A FRONT WILL CONTINUE TO SUPPORT SHOWERS ACROSS OUR AREA
TODAY...BUT WITH LESS COVERAGE THAN BEFORE AS VEERING LOW LEVEL FLOW
LEADS TO LESS OF AN UPSLOPE COMPONENT AND WEAKER ISENTROPIC UPGLIDE.
FORECAST MAXIMUM TEMPERATURES WILL BE WELL ABOVE NORMAL TODAY IN
WARM ADVECTION...AND MODEL CAPE IS QUITE HIGH DURING PEAK HEATING...
WITH THE NAM SHOWING ALMOST 3000 J/KG IN UPSTATE SC...AND THE GFS
2000 J/KG IN NE GA. WITH MODEST SPEED AND DIRECTIONAL SHEAR...SOME
THUNDERSTORMS COULD BE STRONG. DRIER AIR ALOFT AND LOW WET BULB
ZEROS COULD SUPPORT HAIL AND GUSTY WINDS IN THE STRONGER STORMS.
BY THIS EVENING VEERING FLOW ALOFT WILL LEAD TO DRYING FROM THE
WEST...ENDING THE CHANCE OF PRECIPITATION. AFTER MIDNIGHT WINDS
SHIFT TO NW AT THE SURFACE AS THE REMNANTS OF THE FRONT MOVE BY.
MINIMUM TEMPERATURES WILL BE WELL ABOVE NORMAL AS HEIGHTS RISE WITH
THE PROGRESSION OF THE UPPER TROUGH...AND A LIGHT DOWNSLOPE FLOW
ENSUES.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 230 AM EDT TUE...AN UPPER LEVEL RIDGE WILL REMAIN DOMINANT
ACROSS THE EAST THROUGH THE SHORT TERM PERIOD. ANY ISOLATED
CONVECTION UNDER THE RIDGE LATE WED AFTN SHOULD BE LIMITED TO A FEW
MTN RIDGETOP LOCATIONS WHERE UPSLOPE FLOW AND DIFFERENTIAL HEATING
CAN PROVIDE SOME WEAK TRIGGERING. THE MAIN STORY WILL BE WARM
TEMPERATURES...WITH 70S IN THE MTNS AT ALL BUT THE HIGHEST
ELEVATIONS...AND LOWER 80S ACROSS MOST OF THE FOOTHILLS AND
PIEDMONT. THIS SHOULD FALL A DEGREE OR TWO SHORT OF THE RECORDS AT
GSP/84...AND CLT/82.
MTN CONVECTIVE COVERAGE MAY BE JUST A BIT BETTER ON THU AFTN AS LOW
LEVEL CONVERGENCE IN THE WIND FIELD IMPROVES SLIGHTLY.
HOWEVER...DEEP LAYER CAPE SHOULD CONTINUE TO BE RATHER LIMITED AS
MID LEVEL TEMPS WARM FURTHER UNDER THE BUILDING RIDGE. MAX TEMPS
WILL BE COMPARABLE TO A DEGREE WARMER THAN WED. A WEAK WAVE MAY TOP
THE RIDGE THU NIGHT...BUT WITH THE MAIN MOISTURE AND FORCING PASSING
NORTH OF THE REGION THROUGH THE EARLY MORNING HOURS. WILL KEEP SCHC
TO CHC SHOWERS GOING MAINLY IN THE WRN/NRN MTNS FOR THE NIGHTTIME
PERIOD.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AT 230 AM TUESDAY...BOTH THE GFS AND THE ECMWF ARE IN GOOD AGREEMENT
THROUGH THE EXTENDED FORECAST PERIOD. A BROAD UPPER LEVEL RIDGE OF
HIGH PRESSURE WILL PERSIST OVER THE SOUTHEAST...WITH A SERIES OF
SHORTWAVES ORIGINATING IN THE SOUTHERN STREAM MOVING OVER THE RIDGE
ON FRIDAY AND SATURDAY. THE UPPER RIDGING WILL AMPLIFY SIGNIFICANTLY
SUNDAY INTO EARLY NEXT WEEK.
FRIDAY AND SATURDAY...A BROAD SUBTROPICAL HIGH OVER THE SOUTHEAST
U.S. WILL SLOWLY SHIFT EAST AND HEIGHTS WILL BE LOWERED. THIS WILL
ALLOW A SERIES OF WEAK SHORTWAVES OVER THE MISSISSIPPI VALLEYS TO
MOVE NE ACROSS OUR FORECAST AREA DURING THE PERIOD. THE LATEST
FORECAST SOUNDINGS CONTINUE TO INDICATE THAT PRECIPITABLE WATER
VALUES WILL RANGE FROM 1 TO 1.20 INCHES AND LIFTED INDEX VALUES WILL
BE AS LOW AS -4. ALSO...AFTERNOON SURFACE BASED CAPE VALUES WILL BE
IN THE 700 TO 1500 J/KG RANGE OVER MUCH OF OUR CWA. A COMBINATION OF
DECENT DIURNAL INSTABILITY...UPPER DYNAMICS AND DEEP MOISTURE ALOFT
WILL SUPPORT FOR THE DEVELOPMENT OF THUNDERSTORMS. HOWEVER...THE
DEGREE OF INSTABILITY AND UPPER LEVEL SYNOPTIC SCALE FORCING REMAIN
A BIT UNCERTAIN. SO I WILL CONTINUE TO CARRY 30S AND 40S POPS IN THE
AFTERNOON/EVENING HOURS. SUNDAY AND MONDAY...RATHER DRIER CONDITIONS
ARE EXPECTED AS THE UPPER RIDGING SIGNIFICANTLY AMPLIFIES OVER THE
REGION. TEMPERATURES UNDER THE RIDGE WILL BE 1O TO 15 DEGREES ABOVE
NORMAL THROUGH THE FORECAST PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AT KCLT AND ELSEWHERE...STRATUS IS FINALLY LIFTING AND SCATTERING
OUT ACRS THE AREA EARLY THIS AFTN...BUT SOME LINGERING MVFR CIGS
POSSIBLE FOR NEXT HOUR OR SO OVER THE UPSTATE AND KCLT.
OTHERWISE...THE TRENDS ON SATELLITE AND RADAR SEEM TO LINE UP WITH
GUIDANCE WHICH INDICATES ANY CONVECTION THAT DEVELOPS THIS AFTN WILL
PROBABLY BE FAIRLY ISOLATED. SO NO MENTION WILL BE CARRIED IN ANY OF
THE TAF SITES. SKIES GENERALLY CLEAR OUT THIS EVENING...AND GUIDANCE
IS TRENDING MORE PESSIMISTIC WITH FOG DEVELOPMENT EARLY WEDNESDAY
MORNING. SO HAVE GONE A LITTLE LOWER ON VSBY RESTRICTIONS STARTING
AROUND 08-10Z...THEN BURNING OFF QUICKLY BY 14Z.
OUTLOOK...A FEW ISOLD SHRA/TSRA IN THE MTNS WED AND THU AFTNS...WITH
MORNING FOG POSSIBLE IN MOUNTAIN VALLEYS. GREATER COVERAGE OF
SHRA/TSRA EXPECTED FRIDAY AFTN.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...ARK/JAT
SHORT TERM...HG
LONG TERM...JOH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
951 AM EDT TUE MAR 13 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION TODAY FOLLOWED BY
SUBTROPICAL HIGH BUILDING INTO THE REGION THROUGH THE WEEKEND. THIS
WILL RESULT IN AFTERNOON CONVECTION THROUGH THE PERIOD.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM...A CHANNELED VORTMAX WAS ANALYZED ON THE WATER VAPOR
AND RUC 500MB SFC OVR CENTRAL TN...TRACKING THRU QUASI-ZONAL FLOW.
SCATTERED SHOWERS AND A COUPLE OF ISOLD TSTMS WERE BEING TRIGGERED
BY THE ASSOCIATED DPVA ACRS ERN TN/GA. THIS ACTIVITY LOOKS TO REMAIN
ISOLD AND PROBABLY ON A WEAKENING TREND AS IT ENTERS THE CWFA THIS
MORNING...AS SPC MESOANALYSIS SHOWS MUCAPES <500 J/KG IN THE
ENVIRONMENT THE CONVECTION IS MOVING. AS FOR CONVECTION THIS
AFTN...GUIDANCE STILL RATHER SUBDUED DESPITE DESTABILIZATION TO OVER
1500 J/KG AND THE VORTMAX STILL NOT THRU THE AREA BY PEAK HEATING.
ONLY THE 4 KM NCEP WRF HAS ANYTHING MORE THAN A STRAY STORM THIS
AFTN ACRS THE CWFA. BUT I AM GOING TO LEAVE THE LOW-END
CHC/SCATTERED WORDING FOR THE PIEDMONT DUE TO THE TIMING OF THE
VORTMAX FOR NOW. OTHERWISE...ONLY MINOR TWEAKS WERE MADE FOR THE
TODAY PERIOD.
PREVIOUS DISCUSSION...
AT 3 AM EDT TUESDAY...AN UPPER TROUGH AXIS WILL PROGRESS FROM THE OH
AND TN VALLEYS TO THE APPALACHIANS TODAY. A SHORTWAVE MOVING THROUGH
THIS TROUGH WILL CROSS OUR AREA AT MIDDAY. MOISTURE AHEAD OF THE
REMNANTS OF A FRONT WILL CONTINUE TO SUPPORT SHOWERS ACROSS OUR AREA
TODAY...BUT WITH LESS COVERAGE THAN BEFORE AS VEERING LOW LEVEL FLOW
LEADS TO LESS OF AN UPSLOPE COMPONENT AND WEAKER ISENTROPIC UPGLIDE.
FORECAST MAXIMUM TEMPERATURES WILL BE WELL ABOVE NORMAL TODAY IN
WARM ADVECTION...AND MODEL CAPE IS QUITE HIGH DURING PEAK HEATING...
WITH THE NAM SHOWING ALMOST 3000 J/KG IN UPSTATE SC...AND THE GFS
2000 J/KG IN NE GA. WITH MODEST SPEED AND DIRECTIONAL SHEAR...SOME
THUNDERSTORMS COULD BE STRONG. DRIER AIR ALOFT AND LOW WET BULB
ZEROS COULD SUPPORT HAIL AND GUSTY WINDS IN THE STRONGER STORMS.
BY THIS EVENING VEERING FLOW ALOFT WILL LEAD TO DRYING FROM THE
WEST...ENDING THE CHANCE OF PRECIPITATION. AFTER MIDNIGHT WINDS
SHIFT TO NW AT THE SURFACE AS THE REMNANTS OF THE FRONT MOVE BY.
MINIMUM TEMPERATURES WILL BE WELL ABOVE NORMAL AS HEIGHTS RISE WITH
THE PROGRESSION OF THE UPPER TROUGH...AND A LIGHT DOWNSLOPE FLOW
ENSUES.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 230 AM EDT TUE...AN UPPER LEVEL RIDGE WILL REMAIN DOMINANT
ACROSS THE EAST THROUGH THE SHORT TERM PERIOD. ANY ISOLATED
CONVECTION UNDER THE RIDGE LATE WED AFTN SHOULD BE LIMITED TO A FEW
MTN RIDGETOP LOCATIONS WHERE UPSLOPE FLOW AND DIFFERENTIAL HEATING
CAN PROVIDE SOME WEAK TRIGGERING. THE MAIN STORY WILL BE WARM
TEMPERATURES...WITH 70S IN THE MTNS AT ALL BUT THE HIGHEST
ELEVATIONS...AND LOWER 80S ACROSS MOST OF THE FOOTHILLS AND
PIEDMONT. THIS SHOULD FALL A DEGREE OR TWO SHORT OF THE RECORDS AT
GSP/84...AND CLT/82.
MTN CONVECTIVE COVERAGE MAY BE JUST A BIT BETTER ON THU AFTN AS LOW
LEVEL CONVERGENCE IN THE WIND FIELD IMPROVES SLIGHTLY.
HOWEVER...DEEP LAYER CAPE SHOULD CONTINUE TO BE RATHER LIMITED AS
MID LEVEL TEMPS WARM FURTHER UNDER THE BUILDING RIDGE. MAX TEMPS
WILL BE COMPARABLE TO A DEGREE WARMER THAN WED. A WEAK WAVE MAY TOP
THE RIDGE THU NIGHT...BUT WITH THE MAIN MOISTURE AND FORCING PASSING
NORTH OF THE REGION THROUGH THE EARLY MORNING HOURS. WILL KEEP SCHC
TO CHC SHOWERS GOING MAINLY IN THE WRN/NRN MTNS FOR THE NIGHTTIME
PERIOD.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AT 230 AM TUESDAY...BOTH THE GFS AND THE ECMWF ARE IN GOOD AGREEMENT
THROUGH THE EXTENDED FORECAST PERIOD. A BROAD UPPER LEVEL RIDGE OF
HIGH PRESSURE WILL PERSIST OVER THE SOUTHEAST...WITH A SERIES OF
SHORTWAVES ORIGINATING IN THE SOUTHERN STREAM MOVING OVER THE RIDGE
ON FRIDAY AND SATURDAY. THE UPPER RIDGING WILL AMPLIFY SIGNIFICANTLY
SUNDAY INTO EARLY NEXT WEEK.
FRIDAY AND SATURDAY...A BROAD SUBTROPICAL HIGH OVER THE SOUTHEAST
U.S. WILL SLOWLY SHIFT EAST AND HEIGHTS WILL BE LOWERED. THIS WILL
ALLOW A SERIES OF WEAK SHORTWAVES OVER THE MISSISSIPPI VALLEYS TO
MOVE NE ACROSS OUR FORECAST AREA DURING THE PERIOD. THE LATEST
FORECAST SOUNDINGS CONTINUE TO INDICATE THAT PRECIPITABLE WATER
VALUES WILL RANGE FROM 1 TO 1.20 INCHES AND LIFTED INDEX VALUES WILL
BE AS LOW AS -4. ALSO...AFTERNOON SURFACE BASED CAPE VALUES WILL BE
IN THE 700 TO 1500 J/KG RANGE OVER MUCH OF OUR CWA. A COMBINATION OF
DECENT DIURNAL INSTABILITY...UPPER DYNAMICS AND DEEP MOISTURE ALOFT
WILL SUPPORT FOR THE DEVELOPMENT OF THUNDERSTORMS. HOWEVER...THE
DEGREE OF INSTABILITY AND UPPER LEVEL SYNOPTIC SCALE FORCING REMAIN
A BIT UNCERTAIN. SO I WILL CONTINUE TO CARRY 30S AND 40S POPS IN THE
AFTERNOON/EVENING HOURS. SUNDAY AND MONDAY...RATHER DRIER CONDITIONS
ARE EXPECTED AS THE UPPER RIDGING SIGNIFICANTLY AMPLIFIES OVER THE
REGION. TEMPERATURES UNDER THE RIDGE WILL BE 1O TO 15 DEGREES ABOVE
NORMAL THROUGH THE FORECAST PERIOD.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
AT KCLT...GUIDANCE CONSENSUS SUPPORTS THE DEVELOPMENT OF AN MVFR CIG
THIS MORNING THAT LASTS UNTIL MIDDAY. LIGHT SHOWERS MOVING EAST
ACROSS THE FIELD ARE NOT PRODUCING VSBY RESTRICTIONS...AND GUIDANCE
HAS VFR VSBY. CIG IMPROVE TO LOW VFR THIS AFTERNOON...WHEN HEATING
AND INSTABILITY LEND SUPPORT FOR THUNDERSTORMS. COVERAGE WILL BE TOO
SCATTERED TO CARRY THUNDER...BUT CB WILL BE CARRIED IN THE TAF. NO
CIG IS EXPECTED BY EARLY EVENING AS CLOUDS DECREASE WITH A DRYING
WEST WIND ALOFT. SW WINDS APPROACH 10 KNOTS WITH GUSTS TODAY...THEN
GO LIGHT THIS EVENING...VEERING TO NW BEFORE DAWN WEDNESDAY AS THE
REMAIN OF AN OLD FRONT MOVE THROUGH. GUIDANCE SUPPORTS MVFR VSBY
TOWARD DAWN WEDNESDAY MORNING...PERHAPS IFR...BUT CONFIDENCE IS TOO
LOW FOR IFR THIS TIME.
ELSEWHERE...A CONSENSUS OF GUIDANCE SUGGESTS MVFR CIGS WILL CONTINUE
THIS MORNING...WITH PERHAPS SOME BRIEF IFR AT KAVL AND KGSP AT
DAYBREAK. THIS AFTERNOON CIGS RISE TO LOW VFR BEFORE DISSIPATING AS
DRIER AIR MOVES IN WITH WESTERLY FLOW ALOFT. INSTABILITY WILL BE
SUFFICIENT FOR THUNDERSTORMS...HOWEVER COVERAGE WILL BE TOO
SCATTERED FOR INCLUSION IN THE TAFS. CB WILL BE CARRIED HOWEVER.
CLOUDS DECREASE THIS EVENING WITH FURTHER DRYING. LIGHT SW WINDS
WILL APPROACH 10 KNOTS TODAY...THEN BECOME LIGHT AGAIN THIS EVENING.
WINDS VEER TO NW AFTER MIDNIGHT AS THE REMAINS OF A FRONT PASS BY.
GUIDANCE SUGGEST MVFR VSBY TOWARD DAWN WEDNESDAY...PERHAPS IFR AT
KAND...BUT CONFIDENCE IS TOO LIMITED TO CARRY IFR AT THIS TIME.
OUTLOOK...ISOLD-SCT SHRA/TSRA EXPECTED EACH AFTN. EARLY MORNING CIG
AND VSBY RESTRICTIONS POSSIBLE EACH MORNING NEAR AREAS OF RECENT
RAINFALL AND IN MOUNTAIN VALLEYS.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...ARK/JAT
SHORT TERM...HG
LONG TERM...JOH
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1222 PM PDT Wed Mar 14 2012
.SYNOPSIS...
Beginning today a series of wet and occasionally windy storm
systems will bring mainly valley rain and mountain snow through
the remainder of the work week. The late season wet and active
storm parade will continue well into next week.
&&
.DISCUSSION...
rest of today...The trend through the afternoon will be an
increasing trend in precipitation as the next in a series of
disturbances tracks toward the coast. Earlier this morning...a
weak upper level trough passed through southeast and south central
Washington resulting in a small area of light snow over portions
of the Palouse into central Idaho. None of the models forecast
this precipitation...however the Water Vapor loops clearly
depicted the trough and even the RUC picked up on this small
feature. Looking at the current satellite loops...that feature was
now just east of Lewiston...moving steadily eastward. It also
appears to be weakening and as such...the precipitation threat
from it will be rather small. Our focus will now shift to the warm
front currently sweeping through western Washington. This front
will turn the 850 mb flow from its current southeast trajectory to
a more moisture laden southerly one. Precipitable water values
will begin to climb as a result and the chances for precipitation
will as well. The big question is how far east will the developing
precipitation spread. The NAM has been trending a little slower as
has the RUC...which now casts doubts about whether it will
precipitate any further this afternoon over extreme eastern
Washington into the Panhandle. We have lowered pops as a result
over the eastern third of the forecast area...as well as split the
weather grid into early and late afternoon chunks to give a little
temporal resolution to the forecast. Near the Cascades...Okanogan
Highlands/Valley...and western Basin...the chances for
precipitation have been raised as the radar mosaic west of the
crest and over NW Oregon has filled in rapidly. Based on current
wet-bulb temperatures...it seems as all areas will begin the event
as snow. It should change over fairly quick over most valleys...as
the southerly winds will result in steady warming. Snow
accumulations in the valleys will be light...as the precipitation
will be developing during the warmest time of the day...especially
in regards to road temperatures. fx
&&
.AVIATION...
18Z TAFS: An incoming warm front will result in lowering cigs
through the period with most sites developing mvfr cigs and
periods of -ra. The exceptions will occur in KWMH and KEAT where
once the precipitation develops this afternoon it will do so as
snow. Timing the onset of precip in the lee of the Cascades is
always a tough call but it will likely occur before 22z. The
initial shot of precip will fall as -sn which should bring ifr
vsbys...but a changeover will occur before 00z...which should
bring vfr vsbys. For the eastern sites...the precip will likely
begin between 22z-01z...and should fall as -ra. If it arrives
earlier...the chances are better that it would fall as -sn which
would bring lower than fcst vsbys. MVFR cigs are the better bet.
Once the precip begins it will likely continue through much of the
night and into the morning. This system much like the past couple
should contain a decent amount of southerly winds. Generally
speaking this could lead to lighter than fcst precip amounts...and
higher than forecast cigs...spcly over KPUW and KLWS but the
BUFKIT guidance is confident we will be dealing with prolonged
MVFR Cigs and vsbys. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 41 39 46 38 46 34 / 40 80 100 60 40 60
Coeur d`Alene 41 38 43 36 46 34 / 30 90 100 70 40 60
Pullman 44 40 48 36 46 34 / 30 70 90 90 40 60
Lewiston 49 42 55 40 54 37 / 20 60 80 90 30 60
Colville 41 35 46 35 47 34 / 80 100 100 50 50 50
Sandpoint 40 34 42 34 44 32 / 30 90 100 90 50 40
Kellogg 39 35 44 34 44 31 / 40 90 100 100 50 60
Moses Lake 46 42 59 36 54 35 / 50 50 60 30 10 60
Wenatchee 40 36 58 34 48 33 / 60 70 60 30 10 60
Omak 41 35 56 33 48 33 / 80 100 80 20 20 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Winter Weather Advisory until 5 PM PDT Thursday for East Slopes
Northern Cascades.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
849 PM CDT WED MAR 14 2012
.UPDATE...VERY COMPLEX FCST THIS EVENING...SIMILAR TO THOSE OFTEN
ASSOC WITH SMALL SCALE FEATURES IN THE SUMMERTIME. FIRST ISSUE IS
PCPN CHCS. ADMITTEDLY...NOT MUCH GOING ON ATTM AND SEVERAL TIMES
HAVE BEEN TEMPTED TO GO IN AND YANK PCPN FOR TNGT. BUT CONCERN IS
THAT MOISTURE CONVERGENCE IS INCRG ACRS THE NE CORNER OF WI...IN
ATM WHICH IS STILL UNSTABLE. GRB 00Z RAOB HAD STG CAP ARND 800
MB...BUT THAT IS PROBABLY ERODING...AND LOCAL MESO PLOTS SHOW VERY
LIMITED CINH LEFT IN THE FAR NE. WL GIVE IT A BIT MORE TIME TO
SEE IF ANYTHING DEVELOPS BEFORE PULLING PCPN FM FCST.
SECOND ISSUE IS LOW CLD AND FOG POTENTIAL. MODELS INSISTENT THEY
WL DEVELOP OVERNIGHT...BUT NOT SEEING ANYTHING YET. SFC DWPTS
BEHIND THE FRONT IN THE ARROWHEAD VERY DRY...BUT TRAJ OF LOW-LEVEL
PARCELS INTO THE AREA WL COME MORE FM THE NE LATER TNGT. HUNCH NOW
IS THAT WL PROBABLY END UP BACKING AWAY FM THE LOW CLDS AND FOG A
SOME ALSO...BUT WL GIVE THAT A LITTLE MORE TIME TO GET SORTED OUT
AS WELL.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 521 PM CDT WED MAR 14 2012...
SHORT TERM...TONIGHT AND THURSDAY.
THE MAIN CONCERNS IN THE SHORT TERM ARE CHANCES FOR
CONVECTION...LOW CLOUDS AND FOG TONIGHT AND LOW CLOUDS AND
TEMPERATURES ON THURSDAY.
SURFACE ANALYSIS AT 19Z SHOWED A NORTHEAST TO SOUTHWEST COLD
FRONT ACROSS NORTHWEST WISCONSIN. TEMPERATURES AHEAD OF THE FRONT
WERE MAINLY IN THE 60S AND 70S...WITH 40S AND 50S DEW POINTS. A
LAKE BREEZE DEVELOPED AND DROPPED TEMPERATURES IN THE LAKESHORE
COUNTIES INTO THE 50S WITH 40S DEW POINTS. MESOANALYSIS HAD
SURFACE BASED CAPE VALUES IN THE 1000-1500J/KG RANGE IN THE
SOUTHERN PART OF THE FORECAST AREA WHERE 150-300J/KG OF SURFACE
BASED CIN. MODELS ALL SHOWED RATHER STEEP MID LEVEL LAPSE RATES.
THE 12Z GFS AND 09Z SREF HAD QPF IN THE AREA AHEAD OF THE
APPROACHING SURFACE FRONT...THE 12Z ECMWF HAD A LITTLE QPF IN
NORTHEAST WISCONSIN OVERNIGHT. THE 12Z NAM KEPT THE AREA DRY
THROUGH THE SHORT TERM FORECAST PERIOD. 12Z MAV AND 12Z MET BOTH
HAD EXTREMELY LOW POPS. AM CONCERNED ABOUT POTENTIAL CONVECTION
AHEAD OF THE FRONT...BUT ONLY WENT WITH SLIGHT CHANCE POPS FOR THE
EVENING IN THE EAST.
12Z MOS GUIDANCE HAD DENSE FOG AND STRATUS FOR THE GREEN BAY
AREA LATER TONIGHT INTO THURSDAY MORNING. NOT REALLY SEEING
STRATUS BUT LIGHT ONSHORE WINDS AND HIGH DEW POINTS SHOULD BE SUFFICIENT
TO AT LEAST GET SOME FOG. THE FRONT STALLS SOUTH OF THE FORECAST
AREA SO WINDS WILL BE COMING OFF THE LAKE AND BAY...HOLDING
TEMPERATURES DOWN ON THURSDAY. HAVE HIGHS MAINLY IN THE UPPER 50S
TO UPPER 60S AWAY FROM THE LAKE AND IN THE 50S NEAR LAKE MICHIGAN.
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY.
PERSISTENT RIDGE ACROSS THE EASTERN UNITED STATES WILL CONTINUE TO BRING
ABOVE NORMAL TEMPERATURES DURING THE PERIOD. COLD FRONT THAT IS EXPECTED
TO MOVE ACROSS THE AREA TONIGHT WILL SHIFT BACK NORTHWARD AS A
WARM FRONT ON SATURDAY. AFTER A BRIEF COOL DOWN ON FRIDAY...TEMPERATURES
WILL AGAIN WARM WELL INTO THE 60S AND 70S AWAY FROM THE BAY AND LAKE.
RECORD HIGH TEMPERATURES ARE POSSIBLE EACH DAY AT SOME LOCATIONS
FROM SATURDAY THROUGH TUESDAY...ESPECIALLY AWAY FROM THE BAY AND
LAKE. COOLER BY THE LAKE WORDING WILL ALSO BE NEEDED EACH DAY AS
SOUTHERLY FLOW IS EXPECTED. NOT ENOUGH EVIDENCE IN THE MODEL DATA WHERE
WINDS WOULD TURN OFFSHORE TO ALLOW FOR THE IMMEDIATE LAKESHORE
COMMUNITIES TO WARM INTO THE 60S AND 70S.
OTHERWISE...SUMMER LIKE PATTERN WITH WEAK DISTURBANCES ROTATING
AROUND THE BACKSIDE OF THE RIDGE. TRYING TO TIME THESE FEATURES
TOUGH THIS FAR IN ADVANCE. DO THINK SHORTWAVE ENERGY FRIDAY NIGHT
INTO SATURDAY MORNING IS WORTH MENTIONS IN THE ZONE FORECAST PRODUCT.
WOULD HAVE GONE HIGHER POPS WITH THIS FEATURE...BUT TIMING AND LOCATION
ISSUES KEPT CHANCES A LOWER THAN WHAT HAVE LIKED. FIGURE THIS FEATURE
WILL BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO THE REGION.
REMAINDER OF THE EXTENDED HAS SMALL CHANCES FOR SHOWERS AND STORMS THAT
WILL NOT SHOW UP IN THE ZONES FOR MOST PERIODS. LOW CONFIDENCE ON TIMING
OF THE SMALL SCALE FEATURES ON TRIGGERING SHOWERS AND STORMS.
&&
.AVIATION...LOW CONFIDENCE IN CIG AND VSBY FCST FOR 00Z TAFS.
MODELS VERY INSISTENT THAT LOW CLDS AND VSBYS WL BECOME AN ISSUE
OVERNIGHT...IN THE WAKE OF COLD FRONT SLIPPING SWD THROUGH THE
RGN. THE PROBLEM IS...NO SIGN OF THIS HAPPENING YET ON VISIBLE STLT
IMAGERY. PLUS...BY 22Z THE RUC WAS FCSTG VSBYS BLO 1/4 SM OVER
MUCH OF WRN UPR MICHIGAN...AND THE VSREF HAS A GREATER THAN 70
PCT CHC OF VSBYS BLO 1SM IN THAT AREA. THAT IS THE SAME AREA WHICH
IS BASICALLY CLR ON THE STLT...AND HAS SFC DEW POINT DEPRESSIONS
OF NEARLY 25 F DEG RIGHT NOW.
CAN STILL SEE THE CASE FOR LOWER CLDS AND SOME FG DEVELOPING AS
SHALLOW COLD AIR MASS SLIPS SWD ACRS THE AREA. BUT IT CLEARLY IS
GOING TO TAKE LONGER THAN INDICATED BY THE GUID. WL PUSH BACK
TIMING...AND THEN LINGER LONGER INTO TOMORROW AS ELY FLOW
CONTINUES. WL CONT TO MONITOR TRENDS THIS EVENING...AND IF
NOTHING IS DEVELOPING BY THE TIME THE 06Z TAF ISSUANCE COMES
ARND...WL NEED TO SERIOUSLY CONSIDER BACKING OFF ON THE LOW CLDS
IN THE WAKE OF THE FRONT.
SKOWRONSKI
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1252 PM CDT TUE MAR 13 2012
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH WEDNESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE LOW
PRESSURE MOVING EAST OVER SOUTHERN ONTARIO EARLY THIS MORNING WHILE
WEAK HIGH PRESSURE IS SHIFTING INTO THE NORTHERN MISSISSIPPI
VALLEY. LOW CLOUDS ARE IN THE PROCESS OF EXITING NE WISCONSIN...AND
ONLY HIGH CIRRUS IS PUSHING ACROSS THE DAKOTAS UPSTREAM. LOW LEVELS
ARE QUITE DRY THERE...AND THIS DRY AIRMASS WILL MOVE INTO THE REGION
TODAY. FORECAST CONCERNS ARE RELATIVELY MINIMAL FOR THIS TIME OF
THE YEAR...AND INCLUDE MIN HUMIDITIES TODAY...AND TEMPERATURES TODAY
AND TOMORROW.
TODAY...SHORTWAVE TROUGH OVER SOUTHEAST ONTARIO WILL LIFT NE...WHILE
A SHEARED WAVE OVER THE ARROWHEAD MOVES EAST OVER LAKE SUPERIOR.
DESPITE THE SHORTWAVES ALOFT PASSING NEARBY...CYCLONIC FLOW AT THE
SURFACE WILL BE ABATING...WHILE A WEAK RIDGE AXIS SHIFTS INTO THE
REGION THIS AFTERNOON. DRIER AIR OVER THE NORTHERN PLAINS WILL BE
PUSHING ACROSS THE AREA EARLY THIS MORNING...AND THE MVFR STRATUS
WILL BE EXITING NE WISCONSIN BY 09Z OR SO. A VERY DRY AIRMASS WILL
THEN BE IN PLACE FOR THE REST OF THE DAY. THOUGH MIXING MAY ONLY
REACH TO AROUND 900MB...WINDS SHOULD ALLOW FOR DRY AIR ABOVE THE
INVERSION TO CRASH TO THE SURFACE...ESPECIALLY OVER NORTHERN AND FAR
NORTHEAST WISCONSIN WHERE THE GRADIENT WILL BE THE TIGHTEST. HAVE
LOWERED DEWPOINTS TO THE MID TEENS UP NORTH...WHICH GIVES RH/S IN
THE 20-25 PCT RANGE. BOTH THE NAM AND GFS AGREE THAT 925MB TEMPS
WILL RANGE FROM 5-10C ACROSS THE AREA...WHICH CORRESPONDS THE MOST
WITH THE BCCONSRAW AND ECMWBC...THAT GIVES HIGHS RANGING FROM THE
MID 50S NORTH TO MID 60S SOUTH.
TONIGHT...RIDGING WILL BE PASSING OVERHEAD ACROSS THE REGION. WILL
SEE CLEAR TO MOSTLY CLEAR SKIES WITH LIGHT WINDS IN THE EVENING
BECOMING SOUTHEASTERLY. AXIS OF LOW LEVEL MOISTURE WILL GET DRAWN
NORTHWARD INTO CENTRAL WISCONSIN LATE. WITH LOW LEVEL TEMPS ALSO
WARMING AND NO SIGNS OF STRATUS UPSTREAM...THINK POSSIBILITIES OF
LOW STRATUS IS RELATIVELY LOW. LOWS RANGING FROM THE MID 30S
NORTH...TO THE MID 40S SOUTH.
WEDNESDAY...STRONG SHORTWAVE TROUGH WILL BE LIFTING NE OVER CENTRAL
CANADA...WHILE ITS COLD FRONT SAGS INTO NORTHWEST WISCONSIN IN THE
AFTERNOON. AHEAD OF THE FRONT...SOUTHWEST WINDS WILL ADVECT A VERY
WARM AND RELATIVELY MOIST AIRMASS INTO THE REGION. SLIGHTLY BACKED
SE WINDS WILL KEEP FAR NE WISCONSIN A LITTLE COOLER THAN THE REST OF
THE STATE...AND WILL GO WITH HIGHS IN THE UPPER 60S NORTH TO THE
MIDDLE 70S SOUTH. TEMPS MAY STRUGGLE TO GET OUT OF THE 50S ALONG
THE LAKESHORE THOUGH. WEAK CONVERGENCE ALONG THE FRONT COMBINED
WITH A LACK OF UPPER SUPPORT SHOULD KEEP THE FRONT INACTIVE TOMORROW
AFTERNOON SO NO REAL SHOWER OR THUNDER THREAT FORESEEN.
.LONG TERM...WEDNESDAY NIGHT THRU MONDAY. MAIN FORECAST CONCERN IS
HOW HIGH TO GO WITH TEMPS...AND PINNING DOWN BEST CHANCE FOR
SHOWERS/STORMS.
SW FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD...WITH NO COLD AIR
IN SIGHT. TEMPS ALOFT ACTUALLY DO NOT CHANGE MUCH...WITH ONLY A
SLIGHT RISE IN HEIGHTS THIS WEEKEND AND EARLY NEXT WEEK AS THE
UPPER RIDGE BUILDS NORTH INTO ONTARIO. EXPECT 60S FOR MOST
LOCATIONS...WITH SOME 70S POSSIBLE ACROSS CENTRAL WI AND THE FOX
VALLEY NEXT WEEK. SEVERAL RECORDS ARE LIKELY TO FALL. ONLY
EXCEPTION TO THE VERY MILD AIR WILL BE ALONG THE LAKESHORE...AS A
SE SURFACE FLOW OFF OF LAKE MICHIGAN WILL KEEP TEMPS IN THE UPPER
40S AND 50S THROUGH MOST OF THE PERIOD.
FIRST CHANCE FOR SHOWERS/ISO STORMS WILL BE WEDNESDAY NIGHT AS A
WEAK FRONTAL BOUNDARY CROSSES THE AREA. NOT MANY POSITIVES TO GET
SHOWER/STORM ACTIVITY GOING...AS SURFACE CONVERGENCE IS WEAK AND
VERY LITTLE IF ANY UPPER LEVEL SUPPORT...PLUS BETTER MOISTURE
FORECAST TO BE JUST SOUTH/WEST OF THE AREA. THERE WILL BE FAIRLY
STEEP MID-LEVEL LAPSE RATES...ESPECIALLY ACROSS EASTERN WI...SO
WILL CONTINUE WITH HIGHER POPS THERE...BUT KEPT THE CHANCES LOW.
PREVIOUS ECMWF SHOWED A SHORTWAVE OVER THE NORTHERN PLAINS
THURSDAY...AND TOOK THIS FEATURE OVER LAKE SUPERIOR THURSDAY
NIGHT. THIS WOULD HAVE BROUGHT A DECENT CHANCE FOR PRECIP ACROSS
THE NORTH...HOWEVER LATEST RUN AS WELL AS OTHER MODELS AND
ENSEMBLES HAVE RIDGING AND WITH NOT MUCH UPPER SUPPORT OR
MOISTURE...WILL LEAVE THURSDAY NIGHT DRY. IF THIS SHORTWAVE
MATERIALIZES AND SLOWS A LITTLE...PASSING OVER THE AREA ON
FRIDAY...WE COULD GET SOME ACTIVITY TO DEVELOP...BUT THINK THIS IS
UNLIKELY WITH THIS PATTERN. AS WE WORK INTO THIS WEEKEND AND
EARLY NEXT WEEK...TIMING BEST CHANCES FOR SHOWERS/STORMS WILL BE
DIFFICULT AS SYNOPTIC PATTERN DOES NOT SUPPORT PRECIP. MODELS SHOW
POTENTIAL FOR WEAK SHORTWAVES MOVING THROUGH THE PLAINS AND GREAT
LAKES IN THE SW FLOW ALOFT...WHICH WOULD BRING A CHANCE OF
SHOWERS/STORMS. AFTER COORDINATION WITH SURROUNDING OFFICES...WENT
DRY FRIDAY-TUESDAY AS NO PERIOD LOOKS MORE LIKELY THAN THE OTHER
FOR SMALL CHANCE POPS AND UPPER RIDGE BUILDS OVERHEAD. BETTER
CHANCE FOR WIDESPREAD ACTIVITY LOOKS TO ARRIVE MID TO LATE NEXT
WEEK AS CLOSED UPPER LOW EJECTS OUT INTO THE PLAINS.
&&
.AVIATION...EXPECT PATCHY MVFR OR ISOLATED IFR VSBYS IN FOG AROUND
SUNRISE. OTHERWISE...VFR CONDITIONS SHOULD PERSIST ACROSS THE
AREA THROUGHOUT THE TAF PERIOD.
MG
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1108 AM CDT TUE MAR 13 2012
.UPDATE...
CLEAR SKIES WITH DRY AIR AND A HIGH PRESSURE RIDGE MOVING OVERHEAD.
INCREASED TEMPS A DEGREE OR TWO ACROSS THE FORECAST AREA. FULL SUN
AND MIXING TO ALMOST 925 TEMPS OF 10 TO 12C THIS AFTERNOON SHOULD
ALLOW FOR PLENTY OF HEATING INTO THE MID 60S...UPPER 60S TOWARD
SOUTH CENTRAL WI. PRESSURE GRADIENT SHOULD REMAIN TIGHT ENOUGH IN
EASTERN FORECAST AREA TO KEEP OFFSHORE FLOW...SO NO LAKE BREEZE
EXPECTED UNTIL LATE THIS AFTERNOON...AFTER DAYTIME HIGHS ARE MET.
&&
.AVIATION/18Z TAFS/...
A HIGH PRESSURE RIDGE WILL PUSH INTO WISCONSIN LATE THIS AFTERNOON
AND EVENING. WITH DRY AIR IN PLACE...ONLY HIGH CLOUDS OVERHEAD TODAY.
FAIRLY STRONG PRESSURE GRADIENT ALONG THE LAKESHORE TODAY...SO
WESTERLY WINDS WILL DOMINATE. LAKE BREEZE NOT EXPECTED TO REACH MKE
UNTIL EARLY EVENING...AND WINDS WILL BE LIGHT BY THEN.
LIGHT WINDS TONIGHT AND INCREASING LOW LEVEL MOISTURE...SO THERE
COULD BE SOME PATCHY FOG OVERNIGHT...ESPECIALLY IN LOW LYING AREAS.
BREEZY AND VERY WARM ON WEDNESDAY WITH MAINLY CLEAR SKIES. A FRONT
WILL CROSS SOUTHERN WI WED EVENING...POSSIBLY BRINGING SOME SHOWERS
AND THUNDERSTORMS.
&&
.PREV DISCUSSION... /ISSUED 317 AM CDT TUE MAR 13 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH
SURFACE LOW NORTH OF LAKE HURON WILL PUSH EAST AS HIGH PRESSURE FROM
WESTERN MINNESOTA TO MISSOURI MOVES INTO WISCONSIN DURING THE LATE
AFTERNOON AND EARLY EVENING. THE WEST WINDS AROUND 28 KNOTS AT
1 THSD FT DIMINISH TO 15 KNOTS BEFORE LAPSE RATES STEEPEN TO 9.5
C/KM FROM 900 MB DURING THE EARLY AFTERNOON. THEREFORE ONLY A
NARROW WINDOW FOR GUSTS TO AROUND 20 TO 25 MPH AROUND NOON.
THINK THERE WILL BE A LAKE BREEZE IN THE AFTERNOON...ESPECIALLY LATE
AS THE SURFACE HIGH APPROACHES LAKE MICHIGAN. LOCAL 4KM MESO MODEL
KEEPS A WEST/NORTHWEST SURFACE FLOW THROUGH 18Z...THE FARTHEST THE
MODEL RUNS. HOWEVER THE HRRR DOES BEGIN TO BRING SOME ONSHORE WINDS
SOUTH OF MILWAUKEE. EXPECT LATER MESO RUNS WILL SHOW SOME LAKE
BREEZE DEVELOPMENT DURING THE AFTERNOON. EVEN SO...TEMPS WILL HAVE
WARMED QUITE A BIT BY THE TIME THE LAKE BREEZE WOULD PUSH
INLAND...SO WENT WITH MILD HIGH TEMPS ALL THE WAY TO THE
LAKESHORE...THEN FALLING DURING THE MID AFTERNOON.
850 MB WARM AIR ADVECTION BEGINS ESPECIALLY OVER SOUTH CENTRAL
WISCONSIN LATER IN THE AFTERNOON AND CONTINUING TONIGHT.
LACK OF MOISTURE SO LITTLE IN WAY OF ALTOCUMULUS CLOUDS EXPECTED.
DRY LOW LEVELS SO FEW IF ANY CUMULUS.
WARM AIR ADVECTION CONTINUES OVERNIGHT. 925/850 MB MOISTURE
INCREASES TOWARD SUNRISE...ESPECIALLY OVER SOUTH CENTRAL WISCONSIN
AS 850 MB WINDS INCREASE TO 35 KNOTS.
WEDNESDAY - CONFIDENCE...MEDIUM
BROAD ANTICYCLONIC UPPER FLOW WITH WARM SOUTHWEST WINDS BRINGING 925
TEMPS INTO THE 17-19C RANGE. THIS SUGGESTS TEMPS WELL INTO THE 70S
QUITE PLAUSIBLE. MOS GUIDANCE LOOKS TOO COLD AS DO THE 2 METER
TEMPS. BUFKIT MIXED SOUNDINGS LOOK MORE REASONABLE AND MATCHES UP
BETTER WITH 925 TEMP TECHNIQUE.
WEDNESDAY NIGHT - CONFIDENCE...MEDIUM
SURFACE FRONT PUSHES ACROSS SRN WI WITH A RELATIVELY WEAK VORT LOBE.
DECENT INSTABILITY ABOVE 700 MILLIBARS WITH INITIAL LOW LEVEL
NEGATIVE AREA ON SOUNDING...MORE PRONOUNCED ON GFS. BUT THE CAP DOES
ERODE SOME INTO THE OVERNIGHT HOURS. WONDERING WHAT TO MAKE OF THE
CONSENSUS OF MOS SHOWING DENSE FOG DEVELOPMENT. IF WE GET SOME
SHOWERS/STORMS...FLOW DOES BECOME BAGGY SO FOG POTENTIAL DOES HAVE
SOME MERIT.
THURSDAY - CONFIDENCE...MEDIUM
EAST/WEST BOUNDARY LINGERS NEAR SRN WI. BULK OF MODELS SUGGEST QPF
IN THE SOUTHEAST CWA...IN LINE WITH GOING FORECAST. NAM SOUNDING
MUCH MORE ROBUST THAN THE GFS. NAM SHOWS CAPES OVER 1K WITH INVERTED
V LOOK TO SOUNDING. TEMPS HIGHLY DEPENDENT ON FRONTAL PLACEMENT AND
POTENTIAL FOR MORE LAKE INFLUENCE. 925 TEMPS STILL TOASTY. SO INLAND
AREAS THAT SEE SUN SHOULD MAKE THE 70S ONCE AGAIN.
FRIDAY THROUGH MONDAY - CONFIDENCE...LOW TO MEDIUM
CONSENSUS FROM SURROUNDING OFFICES IS TO GO WITH THE DRY LOOK RATHER
THAN THE SLIGHT POPS. UPPER RIDGE GRADUALLY BUILDS UP. APPEARS
FORCING WILL STAY WEST OF THE AREA CLOSER TO HIGHLY AMPLIFIED/SLOW
MOVING DEEP TROUGH. NOT A SLAM DUNK ON THIS AS MODELS SHOW A FEW
WEAK VORTS FLOATING BY HERE AND THERE BUT THINKING WAS TO JUST GO
DRY RATHER THAN HAVE SLIGHTS SPLASHED EVERYWHERE. UNSEASONABLE
WARMTH GOES ON AND ON.
AVIATION/12Z TAFS/...AFTER LINGERING PATCHES OF STRATOCUMULUS CLEARS
EARLY THIS MORNING ONLY FEW-SCATTERED CU EXPECTED WITH VFR CONDITIONS
EXPECTED THIS MORNING AND AFTERNOON AS HIGH PRESSURE PUSHES INTO
WISCONSIN LATE THIS AFTERNOON AND EVENING.
MARINE...WEST TO NORTHWEST WINDS WILL DIMINISH AS HIGH PRESSURE
PUSHES ACROSS LAKE MICHIGAN THIS EVENING. EXPECT A LAKE BREEZE TO
DEVELOP LATER THIS AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
WEDNESDAY THROUGH MONDAY...COLLAR
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
544 AM CDT TUE MAR 13 2012
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE.
.SHORT TERM...TODAY THROUGH WEDNESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE LOW
PRESSURE MOVING EAST OVER SOUTHERN ONTARIO EARLY THIS MORNING WHILE
WEAK HIGH PRESSURE IS SHIFTING INTO THE NORTHERN MISSISSIPPI
VALLEY. LOW CLOUDS ARE IN THE PROCESS OF EXITING NE WISCONSIN...AND
ONLY HIGH CIRRUS IS PUSHING ACROSS THE DAKOTAS UPSTREAM. LOW LEVELS
ARE QUITE DRY THERE...AND THIS DRY AIRMASS WILL MOVE INTO THE REGION
TODAY. FORECAST CONCERNS ARE RELATIVELY MINIMAL FOR THIS TIME OF
THE YEAR...AND INCLUDE MIN HUMIDITIES TODAY...AND TEMPERATURES TODAY
AND TOMORROW.
TODAY...SHORTWAVE TROUGH OVER SOUTHEAST ONTARIO WILL LIFT NE...WHILE
A SHEARED WAVE OVER THE ARROWHEAD MOVES EAST OVER LAKE SUPERIOR.
DESPITE THE SHORTWAVES ALOFT PASSING NEARBY...CYCLONIC FLOW AT THE
SURFACE WILL BE ABATING...WHILE A WEAK RIDGE AXIS SHIFTS INTO THE
REGION THIS AFTERNOON. DRIER AIR OVER THE NORTHERN PLAINS WILL BE
PUSHING ACROSS THE AREA EARLY THIS MORNING...AND THE MVFR STRATUS
WILL BE EXITING NE WISCONSIN BY 09Z OR SO. A VERY DRY AIRMASS WILL
THEN BE IN PLACE FOR THE REST OF THE DAY. THOUGH MIXING MAY ONLY
REACH TO AROUND 900MB...WINDS SHOULD ALLOW FOR DRY AIR ABOVE THE
INVERSION TO CRASH TO THE SURFACE...ESPECIALLY OVER NORTHERN AND FAR
NORTHEAST WISCONSIN WHERE THE GRADIENT WILL BE THE TIGHTEST. HAVE
LOWERED DEWPOINTS TO THE MID TEENS UP NORTH...WHICH GIVES RH/S IN
THE 20-25 PCT RANGE. BOTH THE NAM AND GFS AGREE THAT 925MB TEMPS
WILL RANGE FROM 5-10C ACROSS THE AREA...WHICH CORRESPONDS THE MOST
WITH THE BCCONSRAW AND ECMWBC...THAT GIVES HIGHS RANGING FROM THE
MID 50S NORTH TO MID 60S SOUTH.
TONIGHT...RIDGING WILL BE PASSING OVERHEAD ACROSS THE REGION. WILL
SEE CLEAR TO MOSTLY CLEAR SKIES WITH LIGHT WINDS IN THE EVENING
BECOMING SOUTHEASTERLY. AXIS OF LOW LEVEL MOISTURE WILL GET DRAWN
NORTHWARD INTO CENTRAL WISCONSIN LATE. WITH LOW LEVEL TEMPS ALSO
WARMING AND NO SIGNS OF STRATUS UPSTREAM...THINK POSSIBILITIES OF
LOW STRATUS IS RELATIVELY LOW. LOWS RANGING FROM THE MID 30S
NORTH...TO THE MID 40S SOUTH.
WEDNESDAY...STRONG SHORTWAVE TROUGH WILL BE LIFTING NE OVER CENTRAL
CANADA...WHILE ITS COLD FRONT SAGS INTO NORTHWEST WISCONSIN IN THE
AFTERNOON. AHEAD OF THE FRONT...SOUTHWEST WINDS WILL ADVECT A VERY
WARM AND RELATIVELY MOIST AIRMASS INTO THE REGION. SLIGHTLY BACKED
SE WINDS WILL KEEP FAR NE WISCONSIN A LITTLE COOLER THAN THE REST OF
THE STATE...AND WILL GO WITH HIGHS IN THE UPPER 60S NORTH TO THE
MIDDLE 70S SOUTH. TEMPS MAY STRUGGLE TO GET OUT OF THE 50S ALONG
THE LAKESHORE THOUGH. WEAK CONVERGENCE ALONG THE FRONT COMBINED
WITH A LACK OF UPPER SUPPORT SHOULD KEEP THE FRONT INACTIVE TOMORROW
AFTERNOON SO NO REAL SHOWER OR THUNDER THREAT FORESEEN.
.LONG TERM...WEDNESDAY NIGHT THRU MONDAY. MAIN FORECAST CONCERN IS
HOW HIGH TO GO WITH TEMPS...AND PINNING DOWN BEST CHANCE FOR
SHOWERS/STORMS.
SW FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD...WITH NO COLD AIR
IN SIGHT. TEMPS ALOFT ACTUALLY DO NOT CHANGE MUCH...WITH ONLY A
SLIGHT RISE IN HEIGHTS THIS WEEKEND AND EARLY NEXT WEEK AS THE
UPPER RIDGE BUILDS NORTH INTO ONTARIO. EXPECT 60S FOR MOST
LOCATIONS...WITH SOME 70S POSSIBLE ACROSS CENTRAL WI AND THE FOX
VALLEY NEXT WEEK. SEVERAL RECORDS ARE LIKELY TO FALL. ONLY
EXCEPTION TO THE VERY MILD AIR WILL BE ALONG THE LAKESHORE...AS A
SE SURFACE FLOW OFF OF LAKE MICHIGAN WILL KEEP TEMPS IN THE UPPER
40S AND 50S THROUGH MOST OF THE PERIOD.
FIRST CHANCE FOR SHOWERS/ISO STORMS WILL BE WEDNESDAY NIGHT AS A
WEAK FRONTAL BOUNDARY CROSSES THE AREA. NOT MANY POSITIVES TO GET
SHOWER/STORM ACTIVITY GOING...AS SURFACE CONVERGENCE IS WEAK AND
VERY LITTLE IF ANY UPPER LEVEL SUPPORT...PLUS BETTER MOISTURE
FORECAST TO BE JUST SOUTH/WEST OF THE AREA. THERE WILL BE FAIRLY
STEEP MID-LEVEL LAPSE RATES...ESPECIALLY ACROSS EASTERN WI...SO
WILL CONTINUE WITH HIGHER POPS THERE...BUT KEPT THE CHANCES LOW.
PREVIOUS ECMWF SHOWED A SHORTWAVE OVER THE NORTHERN PLAINS
THURSDAY...AND TOOK THIS FEATURE OVER LAKE SUPERIOR THURSDAY
NIGHT. THIS WOULD HAVE BROUGHT A DECENT CHANCE FOR PRECIP ACROSS
THE NORTH...HOWEVER LATEST RUN AS WELL AS OTHER MODELS AND
ENSEMBLES HAVE RIDGING AND WITH NOT MUCH UPPER SUPPORT OR
MOISTURE...WILL LEAVE THURSDAY NIGHT DRY. IF THIS SHORTWAVE
MATERIALIZES AND SLOWS A LITTLE...PASSING OVER THE AREA ON
FRIDAY...WE COULD GET SOME ACTIVITY TO DEVELOP...BUT THINK THIS IS
UNLIKELY WITH THIS PATTERN. AS WE WORK INTO THIS WEEKEND AND
EARLY NEXT WEEK...TIMING BEST CHANCES FOR SHOWERS/STORMS WILL BE
DIFFICULT AS SYNOPTIC PATTERN DOES NOT SUPPORT PRECIP. MODELS SHOW
POTENTIAL FOR WEAK SHORTWAVES MOVING THROUGH THE PLAINS AND GREAT
LAKES IN THE SW FLOW ALOFT...WHICH WOULD BRING A CHANCE OF
SHOWERS/STORMS. AFTER COORDINATION WITH SURROUNDING OFFICES...WENT
DRY FRIDAY-TUESDAY AS NO PERIOD LOOKS MORE LIKELY THAN THE OTHER
FOR SMALL CHANCE POPS AND UPPER RIDGE BUILDS OVERHEAD. BETTER
CHANCE FOR WIDESPREAD ACTIVITY LOOKS TO ARRIVE MID TO LATE NEXT
WEEK AS CLOSED UPPER LOW EJECTS OUT INTO THE PLAINS.
&&
.AVIATION...MVFR STRATUS IS DEPARTING EASTERN WISCONSIN THIS
MORNING...WHICH SHOULD SET UP VFR CONDITIONS FOR THE REST OF THE TAF
PERIOD. MAY INCLUDE LLWS AT RHI THROUGH MID-MORNING BEFORE WINDS
JUST OFF THE DECK SUBSIDE. OTHERWISE...CLEAR CONDITIONS AS WEAK
HIGH PRESSURE MOVES ACROSS THE REGION.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
317 AM CDT TUE MAR 13 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH
SURFACE LOW NORTH OF LAKE HURON WILL PUSH EAST AS HIGH PRESSURE FROM
WESTERN MINNESOTA TO MISSOURI MOVES INTO WISCONSIN DURING THE LATE
AFTERNOON AND EARLY EVENING. THE WEST WINDS AROUND 28 KNOTS AT
1 THSD FT DIMINISH TO 15 KNOTS BEFORE LAPSE RATES STEEPEN TO 9.5
C/KM FROM 900 MB DURING THE EARLY AFTERNOON. THEREFORE ONLY A
NARROW WINDOW FOR GUSTS TO AROUND 20 TO 25 MPH AROUND NOON.
THINK THERE WILL BE A LAKE BREEZE IN THE AFTERNOON...ESPECIALLY LATE
AS THE SURFACE HIGH APPROACHES LAKE MICHIGAN. LOCAL 4KM MESO MODEL
KEEPS A WEST/NORTHWEST SURFACE FLOW THROUGH 18Z...THE FARTHEST THE
MODEL RUNS. HOWEVER THE HRRR DOES BEGIN TO BRING SOME ONSHORE WINDS
SOUTH OF MILWAUKEE. EXPECT LATER MESO RUNS WILL SHOW SOME LAKE
BREEZE DEVELOPMENT DURING THE AFTERNOON. EVEN SO...TEMPS WILL HAVE
WARMED QUITE A BIT BY THE TIME THE LAKE BREEZE WOULD PUSH
INLAND...SO WENT WITH MILD HIGH TEMPS ALL THE WAY TO THE
LAKESHORE...THEN FALLING DURING THE MID AFTERNOON.
850 MB WARM AIR ADVECTION BEGINS ESPECIALLY OVER SOUTH CENTRAL
WISCONSIN LATER IN THE AFTERNOON AND CONTINUING TONIGHT.
LACK OF MOISTURE SO LITTLE IN WAY OF ALTOCUMULUS CLOUDS EXPECTED.
DRY LOW LEVELS SO FEW IF ANY CUMULUS.
WARM AIR ADVECTION CONTINUES OVERNIGHT. 925/850 MB MOISTURE
INCREASES TOWARD SUNRISE...ESPECIALLY OVER SOUTH CENTRAL WISCONSIN
AS 850 MB WINDS INCREASE TO 35 KNOTS.
WEDNESDAY - CONFIDENCE...MEDIUM
BROAD ANTICYCLONIC UPPER FLOW WITH WARM SOUTHWEST WINDS BRINGING 925
TEMPS INTO THE 17-19C RANGE. THIS SUGGESTS TEMPS WELL INTO THE 70S
QUITE PLAUSIBLE. MOS GUIDANCE LOOKS TOO COLD AS DO THE 2 METER
TEMPS. BUFKIT MIXED SOUNDINGS LOOK MORE REASONABLE AND MATCHES UP
BETTER WITH 925 TEMP TECHNIQUE.
WEDNESDAY NIGHT - CONFIDENCE...MEDIUM
SURFACE FRONT PUSHES ACROSS SRN WI WITH A RELATIVELY WEAK VORT LOBE.
DECENT INSTABILITY ABOVE 700 MILLIBARS WITH INITIAL LOW LEVEL
NEGATIVE AREA ON SOUNDING...MORE PRONOUNCED ON GFS. BUT THE CAP DOES
ERODE SOME INTO THE OVERNIGHT HOURS. WONDERING WHAT TO MAKE OF THE
CONSENSUS OF MOS SHOWING DENSE FOG DEVELOPMENT. IF WE GET SOME
SHOWERS/STORMS...FLOW DOES BECOME BAGGY SO FOG POTENTIAL DOES HAVE
SOME MERIT.
THURSDAY - CONFIDENCE...MEDIUM
EAST/WEST BOUNDARY LINGERS NEAR SRN WI. BULK OF MODELS SUGGEST QPF
IN THE SOUTHEAST CWA...IN LINE WITH GOING FORECAST. NAM SOUNDING
MUCH MORE ROBUST THAN THE GFS. NAM SHOWS CAPES OVER 1K WITH INVERTED
V LOOK TO SOUNDING. TEMPS HIGHLY DEPENDENT ON FRONTAL PLACEMENT AND
POTENTIAL FOR MORE LAKE INFLUENCE. 925 TEMPS STILL TOASTY. SO INLAND
AREAS THAT SEE SUN SHOULD MAKE THE 70S ONCE AGAIN.
FRIDAY THROUGH MONDAY - CONFIDENCE...LOW TO MEDIUM
CONSENSUS FROM SURROUNDING OFFICES IS TO GO WITH THE DRY LOOK RATHER
THAN THE SLIGHT POPS. UPPER RIDGE GRADUALLY BUILDS UP. APPEARS
FORCING WILL STAY WEST OF THE AREA CLOSER TO HIGHLY AMPLIFIED/SLOW
MOVING DEEP TROUGH. NOT A SLAM DUNK ON THIS AS MODELS SHOW A FEW
WEAK VORTS FLOATING BY HERE AND THERE BUT THINKING WAS TO JUST GO
DRY RATHER THAN HAVE SLIGHTS SPLASHED EVERYWHERE. UNSEASONABLE
WARMTH GOES ON AND ON.
&&
.AVIATION/12Z TAFS/...AFTER LINGERING PATCHES OF STRATOCUMULUS CLEARS
EARLY THIS MORNING ONLY FEW-SCATTERED CU EXPECTED WITH VFR CONDITIONS
EXPECTED THIS MORNING AND AFTERNOON AS HIGH PRESSURE PUSHES INTO
WISCONSIN LATE THIS AFTERNOON AND EVENING.
&&
.MARINE...WEST TO NORTHWEST WINDS WILL DIMINISH AS HIGH PRESSURE
PUSHES ACROSS LAKE MICHIGAN THIS EVENING. EXPECT A LAKE BREEZE TO
DEVELOP LATER THIS AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
WEDNESDAY THROUGH MONDAY...COLLAR
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
305 AM CDT TUE MAR 13 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE LOW
PRESSURE MOVING EAST OVER SOUTHERN ONTARIO EARLY THIS MORNING WHILE
WEAK HIGH PRESSURE IS SHIFTING INTO THE NORTHERN MISSISSIPPI
VALLEY. LOW CLOUDS ARE IN THE PROCESS OF EXITING NE WISCONSIN...AND
ONLY HIGH CIRRUS IS PUSHING ACROSS THE DAKOTAS UPSTREAM. LOW LEVELS
ARE QUITE DRY THERE...AND THIS DRY AIRMASS WILL MOVE INTO THE REGION
TODAY. FORECAST CONCERNS ARE RELATIVELY MINIMAL FOR THIS TIME OF
THE YEAR...AND INCLUDE MIN HUMIDITIES TODAY...AND TEMPERATURES TODAY
AND TOMORROW.
TODAY...SHORTWAVE TROUGH OVER SOUTHEAST ONTARIO WILL LIFT NE...WHILE
A SHEARED WAVE OVER THE ARROWHEAD MOVES EAST OVER LAKE SUPERIOR.
DESPITE THE SHORTWAVES ALOFT PASSING NEARBY...CYCLONIC FLOW AT THE
SURFACE WILL BE ABATING...WHILE A WEAK RIDGE AXIS SHIFTS INTO THE
REGION THIS AFTERNOON. DRIER AIR OVER THE NORTHERN PLAINS WILL BE
PUSHING ACROSS THE AREA EARLY THIS MORNING...AND THE MVFR STRATUS
WILL BE EXITING NE WISCONSIN BY 09Z OR SO. A VERY DRY AIRMASS WILL
THEN BE IN PLACE FOR THE REST OF THE DAY. THOUGH MIXING MAY ONLY
REACH TO AROUND 900MB...WINDS SHOULD ALLOW FOR DRY AIR ABOVE THE
INVERSION TO CRASH TO THE SURFACE...ESPECIALLY OVER NORTHERN AND FAR
NORTHEAST WISCONSIN WHERE THE GRADIENT WILL BE THE TIGHTEST. HAVE
LOWERED DEWPOINTS TO THE MID TEENS UP NORTH...WHICH GIVES RH/S IN
THE 20-25 PCT RANGE. BOTH THE NAM AND GFS AGREE THAT 925MB TEMPS
WILL RANGE FROM 5-10C ACROSS THE AREA...WHICH CORRESPONDS THE MOST
WITH THE BCCONSRAW AND ECMWBC...THAT GIVES HIGHS RANGING FROM THE
MID 50S NORTH TO MID 60S SOUTH.
TONIGHT...RIDGING WILL BE PASSING OVERHEAD ACROSS THE REGION. WILL
SEE CLEAR TO MOSTLY CLEAR SKIES WITH LIGHT WINDS IN THE EVENING
BECOMING SOUTHEASTERLY. AXIS OF LOW LEVEL MOISTURE WILL GET DRAWN
NORTHWARD INTO CENTRAL WISCONSIN LATE. WITH LOW LEVEL TEMPS ALSO
WARMING AND NO SIGNS OF STRATUS UPSTREAM...THINK POSSIBILITIES OF
LOW STRATUS IS RELATIVELY LOW. LOWS RANGING FROM THE MID 30S
NORTH...TO THE MID 40S SOUTH.
WEDNESDAY...STRONG SHORTWAVE TROUGH WILL BE LIFTING NE OVER CENTRAL
CANADA...WHILE ITS COLD FRONT SAGS INTO NORTHWEST WISCONSIN IN THE
AFTERNOON. AHEAD OF THE FRONT...SOUTHWEST WINDS WILL ADVECT A VERY
WARM AND RELATIVELY MOIST AIRMASS INTO THE REGION. SLIGHTLY BACKED
SE WINDS WILL KEEP FAR NE WISCONSIN A LITTLE COOLER THAN THE REST OF
THE STATE...AND WILL GO WITH HIGHS IN THE UPPER 60S NORTH TO THE
MIDDLE 70S SOUTH. TEMPS MAY STRUGGLE TO GET OUT OF THE 50S ALONG
THE LAKESHORE THOUGH. WEAK CONVERGENCE ALONG THE FRONT COMBINED
WITH A LACK OF UPPER SUPPORT SHOULD KEEP THE FRONT INACTIVE TOMORROW
AFTERNOON SO NO REAL SHOWER OR THUNDER THREAT FORESEEN.
.LONG TERM...WEDNESDAY NIGHT THRU MONDAY. MAIN FORECAST CONCERN IS
HOW HIGH TO GO WITH TEMPS...AND PINNING DOWN BEST CHANCE FOR
SHOWERS/STORMS.
SW FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD...WITH NO COLD AIR
IN SIGHT. TEMPS ALOFT ACTUALLY DO NOT CHANGE MUCH...WITH ONLY A
SLIGHT RISE IN HEIGHTS THIS WEEKEND AND EARLY NEXT WEEK AS THE
UPPER RIDGE BUILDS NORTH INTO ONTARIO. EXPECT 60S FOR MOST
LOCATIONS...WITH SOME 70S POSSIBLE ACROSS CENTRAL WI AND THE FOX
VALLEY NEXT WEEK. SEVERAL RECORDS ARE LIKELY TO FALL. ONLY
EXCEPTION TO THE VERY MILD AIR WILL BE ALONG THE LAKESHORE...AS A
SE SURFACE FLOW OFF OF LAKE MICHIGAN WILL KEEP TEMPS IN THE UPPER
40S AND 50S THROUGH MOST OF THE PERIOD.
FIRST CHANCE FOR SHOWERS/ISO STORMS WILL BE WEDNESDAY NIGHT AS A
WEAK FRONTAL BOUNDARY CROSSES THE AREA. NOT MANY POSITIVES TO GET
SHOWER/STORM ACTIVITY GOING...AS SURFACE CONVERGENCE IS WEAK AND
VERY LITTLE IF ANY UPPER LEVEL SUPPORT...PLUS BETTER MOISTURE
FORECAST TO BE JUST SOUTH/WEST OF THE AREA. THERE WILL BE FAIRLY
STEEP MID-LEVEL LAPSE RATES...ESPECIALLY ACROSS EASTERN WI...SO
WILL CONTINUE WITH HIGHER POPS THERE...BUT KEPT THE CHANCES LOW.
PREVIOUS ECMWF SHOWED A SHORTWAVE OVER THE NORTHERN PLAINS
THURSDAY...AND TOOK THIS FEATURE OVER LAKE SUPERIOR THURSDAY
NIGHT. THIS WOULD HAVE BROUGHT A DECENT CHANCE FOR PRECIP ACROSS
THE NORTH...HOWEVER LATEST RUN AS WELL AS OTHER MODELS AND
ENSEMBLES HAVE RIDGING AND WITH NOT MUCH UPPER SUPPORT OR
MOISTURE...WILL LEAVE THURSDAY NIGHT DRY. IF THIS SHORTWAVE
MATERIALIZES AND SLOWS A LITTLE...PASSING OVER THE AREA ON
FRIDAY...WE COULD GET SOME ACTIVITY TO DEVELOP...BUT THINK THIS IS
UNLIKELY WITH THIS PATTERN. AS WE WORK INTO THIS WEEKEND AND
EARLY NEXT WEEK...TIMING BEST CHANCES FOR SHOWERS/STORMS WILL BE
DIFFICULT AS SYNOPTIC PATTERN DOES NOT SUPPORT PRECIP. MODELS SHOW
POTENTIAL FOR WEAK SHORTWAVES MOVING THROUGH THE PLAINS AND GREAT
LAKES IN THE SW FLOW ALOFT...WHICH WOULD BRING A CHANCE OF
SHOWERS/STORMS. AFTER COORDINATION WITH SURROUNDING OFFICES...WENT
DRY FRIDAY-TUESDAY AS NO PERIOD LOOKS MORE LIKELY THAN THE OTHER
FOR SMALL CHANCE POPS AND UPPER RIDGE BUILDS OVERHEAD. BETTER
CHANCE FOR WIDESPREAD ACTIVITY LOOKS TO ARRIVE MID TO LATE NEXT
WEEK AS CLOSED UPPER LOW EJECTS OUT INTO THE PLAINS.
&&
.AVIATION...CLDS PROGRESSING EWD ABOUT AS EXPECTED. CLDS SHOULD
CONT TO DECR FM W-E OVERNIGHT AS UPR LOW PULLS AWAY. THEN EXPECT
VFR CONDITIONS THRU TOMORROW.
SKOWRONSKI
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/BERSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1150 PM CDT MON MAR 12 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
303 PM CDT MON MAR 12 2012
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT
ANALYSIS SHOWED SOUTHWEST FLOW FROM THE PACIFIC NORTHWEST TO
HUDSON BAY... WITH A SHORTWAVE TROUGH OVER SASKATCHEWAN. IN THE
SOUTHERN STREAM...AN UPPER LOW WAS NEAR EAU CLAIRE WITH A
SHORTWAVE ROUNDING ITS BASE OVER NORTHERN ILLINOIS. THIS LATTER
SHORTWAVE IS HELPING TO SUSTAIN SHOWERS AND A FEW THUNDERSTORMS
OVER SOUTHEAST WISCONSIN AND NORTHERN ILLINOIS...AIDED BY DAYTIME
HEATING. OTHER SHOWER ACTIVITY WAS OVER NORTHERN AND CENTRAL
WISCONSIN...AIDED BY DPVA FORCING AHEAD OF THE UPPER LOW. ANOTHER
AREA OF SHOWERS WERE WEST OF MINNEAPOLIS IN THE DEFORMATION ON THE
BACK SIDE OF THE UPPER LOW. THERE HAS BEEN SOME PARTIAL CLEARING
TODAY SOUTH OF I-90...THANKS TO DRY AIR WRAPPING AROUND THE UPPER
LOW. THIS CLEARING COMBINED WITH A WARM LAST NIGHT HAS ALLOWED
TEMPERATURES TO CLIMB MOSTLY INTO THE 50S...DESPITE 850MB TEMPS
WHICH HAVE DROPPED TO 2-4C PER RUC ANALYSIS...AND THE 3C READING
AT OAX AT 12Z. MUCH WARMER AIR AT 850MB EXISTS OVER THE
DAKOTAS...THOUGH...WITH READINGS OF 12C AT BIS AND UNR AT 12Z.
TONIGHT AND TUESDAY...THE UPPER LOW OVER WESTERN WISCONSIN IS
PROGGED TO CONTINUE ITS NORTHEASTWARD TREK...LIFTING INTO NORTHEAST
ONTARIO BY 12Z TUESDAY. IT APPEARS THIS UPPER LOW WILL THEN SLOW
DOWN...DUE TO THE CURRENT SHORTWAVE TROUGH IN SASKATCHEWAN WHICH
MODELS HAVE IT PHASING WITH THE UPPER LOW. THE ONLY IMPACTS THIS
PHASING HAS ON OUR FORECAST AREA IS NORTH OF I-94 TUESDAY
MORNING...WHERE SLIGHTLY COOLER AND DRIER AIR WILL MOVE IN.
OTHERWISE...850MB TEMPS ARE PROGGED TO BE ON THE RISE THROUGHOUT
THIS TIME PERIOD. AT 12Z TUESDAY...THEY SHOULD RANGE FROM
4-8C...THEN RISE TO 8-12C BY 00Z WEDNESDAY. THIS WARMING COMBINED
WITH CLEARING SKIES AND DRIER AIR FOR TUESDAY SHOULD RESULT IN
DECENT MIXING. STAYED TOWARD THE HIGH END OF GUIDANCE FOR HIGHS
WHICH PUTS THEM CLOSE TO OR ABOVE RECORD VALUES. REGARDING TONIGHTS
LOWS...PRECIPITABLE WATER VALUES ARE FORECAST TO DROP TO 0.25 INCH
BY 12Z OR LOWER AFTER BEING UP BETWEEN 0.5-0.75 INCHES. THIS DRY AIR
SHOULD HELP TEMPERATURES DROP...THOUGH WINDS KIND OF STAY UP THROUGH
MUCH OF THE NIGHT UNTIL LATE. THEREFORE HAVE TAKEN A BLEND OF
GUIDANCE APPROACH. COULD HAVE SOME PATCHY FOG WHERE WINDS CAN
DECOUPLE DUE TO RECENT RAINS...WHILE THE OVERALL WIND ESPECIALLY
RIGHT ABOVE THE SURFACE KEEPS THE FOG FROM BECOMING MORE WIDESPREAD.
TUESDAY NIGHT THROUGH THURSDAY...A BIG CHUNK OF THE UPPER TROUGHING
CURRENTLY OFF THE PACIFIC NORTHWEST COAST IS FORECAST TO LIFT OUT
INTO SOUTHWEST CANADA TUESDAY NIGHT...THEN UP TO HUDSON BAY BY
WEDNESDAY NIGHT. A STRONG LOW PRESSURE SYSTEM DEVELOPS FROM THIS
UPPER TROUGHING...THOUGH AGAIN WELL OFF TO OUR NORTH. HOWEVER...
THERE ARE GOING TO BE SOME IMPACTS FROM IT. FIRST...A SURGE OF WARM
AIR CAUSED BY DOWNSLOPING OFF THE ROCKIES WILL MOVE INTO THE AREA.
THE FIRST FEELING OF THIS COMES TUESDAY NIGHT AS INCREASING
SOUTHEAST TO SOUTH WINDS BRING HIGHER DEWPOINTS AND 850MB TEMPS RISE
TO 12-14C. THIS SITUATION MAY KEEP TEMPERATURES FROM FALLING BELOW
50 ALONG AND WEST OF THE MISSISSIPPI RIVER. ON WEDNESDAY...WINDS
TURN SOUTHWEST AHEAD OF THE LOW PRESSURE SYSTEMS COLD FRONT
CROSSING MINNESOTA. THERE ARE INDICATIONS FROM THE 12.12Z NAM/ECMWF
THAT 850MB TEMPS COULD EVEN RISE TO 16C OVER NORTHEAST IOWA...ALMOST
3 STANDARD DEVIATIONS ABOVE NORMAL. WITH PLENTY OF SUN AND A WARM
START...TEMPERATURES SHOULD EASILY CLIMB INTO THE 70S. AN 80F
READING MAY EVEN OCCUR (NOTE 81F HIGH FOR SPARTA OFF MET GUIDANCE).
DEWPOINTS ARE ALSO EXPECTED TO CLIMB INTO THE 50S WITH A GOOD FETCH
COMING OUT OF THE GULF OF MEXICO. THE COMBINATION OF THE
UNPRECEDENTED WARMTH AND DEWPOINTS WILL LIKELY LEAD TO CUMULUS
DEVELOPMENT...MAKING IT FEEL MORE LIKE LATE SPRING THAN MID MARCH.
FOR WEDNESDAY NIGHT INTO THURSDAY...THE UPPER FLOW TURNS A LITTLE
MORE TOWARDS WEST...ENOUGH TO ALLOW THE WEAKENING COLD FRONT TO MOVE
INTO THE FORECAST AREA. BELIEVE THE 12.12Z NAM IS TOO AGGRESSIVE ON
THE SPEED GIVEN THE 12.12Z GFS/UKMET/ECMWF SLOWER. IN ANY EVENT...
THE FRONT WILL RE-ORIENT ITSELF WEST-EAST...LIKELY OCCURRING ON
THURSDAY NEAR OR JUST SOUTH OF I-90. CONVECTIVE INITIATION ON THE
FRONT DOES NOT SEEM LIKELY...DUE TO CAPPING. THE 12.12Z GFS DOES TRY
TO SPIT OUT THESE VERY LIGHT QPF VALUES...BUT THIS IS MORE FROM THE
MODEL BRINGING IN TOO MUCH LOW LEVEL MOISTURE AND GENERATING
STRATUS/DRIZZLE VERSUS CONVECTION. EVEN THEN...THE PATTERN DOES NOT
FAVOR STRATUS/DRIZZLE AND THE MODEL SEEMS TO HAVE A HIGH MOISTURE
BIAS. EVEN WITH THE FRONTAL PASSAGE...850MB TEMPS ONLY DROP TO
10-12C SO THURSDAY MAY ONLY END UP A LITTLE COOLER THAN WEDNESDAY.
WEDNESDAY NIGHT ALSO LIKELY STAYING MILD...ESPECIALLY AHEAD OF THE
FRONT.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
303 PM CDT MON MAR 12 2012
MAIN STORY REMAINS THE UNPRECEDENTED WARMTH WHICH LOOKS TO PERSIST
THROUGH THE ENTIRE LONG TERM PERIOD AND BEYOND.
VERY GOOD MODEL AGREEMENT EXISTS THAT A DEEP UPPER LEVEL TROUGH IS
GOING TO DEVELOP ALONG THE WEST COAST OF THE U.S. FRIDAY INTO
SATURDAY. AS A RESULT...RIDGING BUILDS DOWNSTREAM OVER THE CENTRAL
AND EASTERN U.S.. THIS RIDGE BECOMES QUITE STRONG AND ACCORDING TO
THE CFS V2 MODEL...IT MAY PERSIST RIGHT THROUGH THE END OF THE
MONTH...WHILE THE WEST COAST TROUGH STAYS PUT OR CUTS-OFF. SINCE THE
CFS HAS BEEN DOING VERY WELL OVER THE PAST FEW MONTHS...HAVE
PREFERRED MODEL SCENARIOS WHICH KEEP THE WESTERN TROUGH IN
PLACE...WHICH LUCKILY MOST MODELS DO INCLUDING THE NEW 12.12Z ECMWF.
FOLLOWING THIS IDEA...850MB TEMPS THROUGHOUT THE LONG TERM PERIOD
STAY BETWEEN 10-14C OR 2-2.5 STANDARD DEVIATIONS ABOVE NORMAL. THIS
WOULD MEAN HIGHS NEAR OR ABOVE RECORD HIGHS. HAVE ADJUSTED ALL HIGH
TEMPERATURES TOWARDS THE HIGH END OF GUIDANCE. A PERSISTENT SOUTH
WIND OF 20-40 KT AT 925MB WILL HELP TO KEEP A PULL OF MOISTURE OUT
OF THE GULF OF MEXICO...THOUGH LACK OF VEGETATION AND THE DISTANCE
FROM THE GULF SHOULD HOLD DEWPOINTS BELOW 60. WITH THE WARM
TEMPERATURES AND DEWPOINTS...ANTICIPATING A LOT OF PARTLY SUNNY DAYS
DUE TO CUMULUS DEVELOPMENT.
PRECIPITATION CHANCES ARE VERY UNCERTAIN AND IT IS ENTIRELY POSSIBLE
THAT THE WHOLE LONG TERM PERIOD ENDS UP DRY. HOWEVER...WITH THE WELL
ABOVE NORMAL DEWPOINTS INTERACTING WITH WEAK SHORTWAVES COMING OUT
OF THE PACIFIC THROUGH THE BUILDING RIDGING...CANNOT RULE OUT A FEW
PERIODS OF SHOWERS AND THUNDERSTORMS. HAVE 20-30 PERCENT CHANCES
THROUGHOUT MUCH OF THE LONG TERM AS A RESULT. MUST BE STRESSED THAT
MUCH OF THIS PERIOD WILL LIKELY BE DRY.
&&
.AVIATION...THROUGH 06Z WEDNESDAY
1149 PM CDT MON MAR 12 2012
IR SATELLITE SHOWING BACK EDGE OF MVFR/VFR STRATOCUMULUS PUSHING
EAST OF THE MISSISSIPPI RIVER NOW AS A RIDGE OF HIGH PRESSURE
BUILDS IN FROM THE PLAINS. CLEAR SKIES AND LIGHT WINDS NEAR THE
RIDGE AXIS MAY PRODUCE SOME PATCHY FOG ACROSS PORTIONS OF
SOUTHEAST MN INCLUDING KRST IN THE 10-13Z TIME FRAME...BUT
CONFIDENCE IS NOT HIGH DUE TO LIGHT WESTERLY COMPONENT TO THE
SURFACE WIND. WILL CONTINUE MENTION OF SOME LIGHT 6SM BR IN THAT
TIME FRAME. OTHERWISE...VFR/CLEAR CONDITIONS EXPECTED THROUGH
TUESDAY EVENING. LOOK FOR LIGHT WESTERLY WINDS IN THE 5 TO 10KT
RANGE TO BACK TO THE SOUTH TODAY AS THE RIDGE AXIS SHIFTS EAST OF
THE REGION.
&&
.CLIMATE...THROUGH EARLY NEXT WEEK
303 PM CDT MON MAR 12 2012
WELL ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGHOUT MUCH OF THE
NEXT 7 DAYS AND LIKELY BEYOND. AT LA CROSSE AND ROCHESTER...THE NEXT
3 DAYS APPEAR TO BE RELATIVE MINIMUMS FOR WHAT THE GOING RECORDS
ARE...SO ANY OF THE DAYS WILL HOLD A CHANCE FOR BREAKING THE RECORD.
WEDNESDAY STILL LOOKS LIKE THE WARMEST DAY OF THE WEEK AND HOLDS THE
HIGHEST POTENTIAL FOR BREAKING THE RECORDS WITH HIGHS EXPECTED IN
THE 70S. A FEW PLACES COULD EVEN APPROACH 80. HEADING INTO THE
WEEKEND AND EARLY NEXT WEEK...RECORDS VARY IN TERMS OF HOW HIGH THEY
ARE...BUT DEFINITELY POTENTIAL EXISTS FOR MORE RECORDS TO BE BROKEN.
SEE OUR WEBSITE FOR A LISTING OF RECORD HIGHS THROUGH EARLY NEXT
WEEK.
&&
.HYDROLOGY...
1232 PM CDT MON MAR 12 2012
ACCORDING TO OFFICIALS THERE HAVE BEEN SOME LOCALIZED ICE BLOCKAGES
ALONG THE BLACK RIVER FROM AROUND THE NEILLSVILLE AREA DOWN TO THE
UPPER PORTION OF LAKE ARBUTUS NEAR HATFIELD. REPORTS INDICATE THAT
THERE ARE LARGE BLOCKS OF ICE MOVING DOWN THE RIVER...AND THEY ARE
OCCASIONALLY GETTING HUNG UP ON RIVER BENDS AND WHERE ROCKS CAUSE
CONSTRICTIONS IN THE RIVER.
AT THIS POINT...IT DOES NOT APPEAR THERE IS A LARGE RISK FOR
FLOODING DUE TO ICE JAMS. BUT THERE IS A RISK FOR RAPID WITHIN-BANK
RISES ALONG THE BLACK RIVER DUE TO THIS ICE ACTION. WE HAVE ALREADY
SEEN SOME RISES ON THE RIVER MONITORING GAUGES IN THAT AREA.
THERE IS STILL SOME SNOW COVER OVER THE HEADWATER OF THE BLACK RIVER
BASIN...FROM WITHEE UP TO MEDFORD. WITH THE WARM TEMPERATURES
EXPECTED THIS WEEK...THAT SNOW IS EXPECTED TO MELT AND RUNOFF
QUICKLY INTO THE RIVER. THE ICE THAT REMAINS IN THE RIVER IS
EXPECTED TO BREAK UP AND MOVE DOWNSTREAM...SO WATER LEVELS WILL NEED
TO BE MONITORED THIS WEEK AS THAT COMBINATION WILL LEAD TO HIGHER
WATER ALONG THE BLACK RIVER THIS WEEK.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
303 PM CDT MON MAR 12 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
CLIMATE...AJ
HYDROLOGY...MW
AREA FORECAST DISCUSSION
NWS ALBANY NY
550 AM EDT THU MAR 15 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL BRING SCATTERED SHOWERS AND PERHAPS A RUMBLE
OF THUNDER FROM ALBANY NORTH AND WEST EARLY IN THE MORNING. THEN
AFTER A BREAK IN THE ACTION...A STRONGER DISTURBANCE...LINKED WITH A
MID LEVEL WARM FRONT...WILL BRING A BETTER CHANCE OF SHOWERS AND
ANOTHER THUNDERSTORM LATER TONIGHT INTO FRIDAY. HIGH PRESSURE WILL
SLOWLY BUILD IN FRIDAY NIGHT INTO SATURDAY BRING DRIER CONDITIONS
ALONG WITH VERY MILD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 530 AM...SHOWERS AND ISOLATED THUNDERSTORMS MOVING QUICKLY
INTO THE MOHAWK VALLEY. THE 06Z NAM HAD ABSOLUTELY NO EVIDENCE OF
THEM ON THE PLANAR VIEW. THE LATEST HRRR AND RUC HAD FORECASTED SOME
ACTIVITY BUT IN THE WRONG PLACES AND WRONG TIMES.
THIS SHORT-WAVE...POORLY FORECASTED BY THE MODELS...HAS BEEN
RE-TOOLED IN GFE. WE ARE THINKING IT WILL WEAKEN AS IT MOVES AWAY
FROM ITS THETA-E SOURCE BUT STILL CARRY ISOLATED ACTIVITY PAST THE
GREATER CAPITAL DISTRICT THROUGH AT LEAST EARLY MORNING. THIS
ACTIVITY NOW STRETCHES BACK BEYOND LAKE ONTARIO SO WE MIGHT HAVE TO
EXTEND IT EVEN FURTHER INTO THE MORNING.
TEMPERATURES THIS MORNING WERE GENERALLY COLDER THIS MORNING THAN
PAST MORNING...AND IN SOME CASES...BELOW FREEZING (LIKE GLENS
FALLS). CONCERN IS THAT WITH SHOWERS MOVING INTO THESE REGIONS THERE
IS A REMOTE POSSIBILITY THAT FREEZING RAIN COULD FALL. WE WILL
MONITOR AND ISSUE MORE SPECIAL WEATHER STATEMENTS AS NEEDED.
AFTER THE DISTURBANCE MOVES THROUGH LATER THIS MORNING...IT LOOKS
DRY THROUGH MUCH OF THE AFTERNOON. HOWEVER... A STRONGER DISTURBANCE
EVIDENT ON THE H20 LP OVER THE NORTHWESTERN GREAT LAKES WILL HEAD
TOWARD OUR REGION...BUT NOT UNTIL VERY LATE IN THE DAY OR MORE
LIKELY...EVENING.
THE 11U-3.9U INDICATES THE STRATUS HAS NOT MADE MUCH PROGRESS
NORTHWARD OF LONG ISLAND WHILE AC AHEAD OF THE SHOWERS AND
THUNDERSTORMS WERE WORKING ACROSS THE MOHAWK VALLEY.
ONCE CLOUDS ASSOCIATED WITH THE DISTURBANCE MOVES ON BY TO OUR
SOUTHEAST LATER TODAY...SOME SUNSHINE IS EXPECTED BEFORE CLOUDS TEND
TO INCREASE LATER THIS MORNING BEFORE THE NEXT BATCH OF CLOUDS ROLL
IN.
WE EXPECT HIGH TEMPERATURES SOMEWHAT SIMILAR TO WEDNESDAY/S
GENERALLY IN THE 50S. THE MID HUDSON VALLEY AND LOWER LITCHFIELD
AREA WILL BE COOLER THAN YESTERDAY AS THE WIND FLOW WILL BE
SOUTHEAST...SO THEREFORE NO BENEFICIAL DOWNSLOPE WILL ENSUE OFF THE
CATSKILLS...TOPPING OUT AROUND 60.
ONCE AGAIN HOWEVER...THESE VALUES WILL BE RUNNING AT LEAST 10
DEGREES ABOVE NORMAL FOR MID MARCH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT INTO FRIDAY AFTERNOON...THE AFOREMENTIONED SHORTWAVE ALONG
WITH IT/S WEAK SFC LOW REFLECTION WILL BE MOVING FROM THE GREAT
LAKES SOUTHEASTWARD TOWARDS UPSTATE NY. THIS WILL ALLOW FOR LIKELY
SHOWERS AND THE CHANCE OF THUNDERSTORMS ACROSS OUR AREA...MAINLY
OVERNIGHT. SHOWALTER VALUES CONTINUE SLIGHTLY NEGATIVE...AND MIXED
LAYER MUCAPE VALUES RANGE BETWEEN 0 AND 400 J/KG. WHILE THERE MAY BE
A FEW RUMBLES OF THUNDER AROUND...AND 850-500 HPA LAPSE RATES WILL
BE AROUND 6.5 DEGREES C/KM...IT/S UNLIKELY ANY STORM WOULD BECOME
STRONG DUE TO THE RELATIVELY LOW DEWPOINT TEMPS AND MEAGER CAPE.
OVERNIGHT LOW TEMPERATURES WILL WITH THE CLOUDS AND ANTICIPATED
SHOWER ACTIVITY...OVERNIGHT LOWS WILL BE MILD TONIGHT...WITH MOST
AREAS IN THE UPPER 30S TO MID 40S. TEMPERATURES ON FRIDAY WILL BE A
LITTLE COOLER THAN RECENT DAYS...BUT STILL MILD FOR THIS TIME OF
YEAR...MAINLY IN THE MID OR UPPER 50S. (A FEW READINGS AROUND 60 IN
THE MID HUDSON VALLEY).
BY FRIDAY EVENING...THE DISTURBANCE WILL BE PASSING EAST OF THE
REGION AND A DRYING TREND WILL SET IN. AN UPPER LEVEL RIDGE OVER THE
MIDWEST WILL BUILD INTO THE AREA FOR THE OVERNIGHT
HOURS...ALLOWING THE THREAT FOR SHOWERS TO END. A SURFACE HIGH WILL
BUILDING SOUTHWARD FROM CANADA. THIS SETUP USUALLY POSES A CHALLENGE
TO HOW QUICKLY WE CLEAR OUT...AS MOISTURE COULD EASILY GET TRAPPED
UNDERNEATH AN LOWERING INVERSION. THUS FAR...MODELS ARE OPTIMISTIC
THAT CLOUDS WILL AT LEAST THIN. HOWEVER IF THEY DO...CHANCES FOR FOG
WILL INCREASE. FOR NOW...WENT PARTLY CLOUDY WITH PATCHY FOG.
ASSUMING THIS MIDDLE OF THE ROAD SCENARIO...TEMPERATURES WILL DIP TO
THE MID 30S TO LOWER 40S. IF CLOUDS WERE TO PERSIST...OVERNIGHT LOWS
WOULD BE A LITTLE MILDER. ON THE OTHER HAND...IF WE WERE TO CLEAR
MORE QUICKLY...READINGS COULD DIP A BIT LOWER...ALLOWING MORE
EXTENSIVE FOG TO POSSIBLY FORM.
SATURDAY...HIGH TEMPERATURES WILL TRICKY TO FORECAST. WE ASSUME A
GOOD DEAL OF SUNSHINE. HOWEVER...THE MEAN AIR FLOW WILL BE SSE (AS
OPPOSED TO SSW) SO THERE COULD BE LINGERING MARINE INFLUENCES. THE
MET GUIDANCE (OFF THE NAM MODEL) INDICATED TEMPERATURES ONLY
REACHING THE 50S ON SATURDAY WHILE THE MAV GUIDANCE (BASED OFF THE
GFS MODEL) INDICATE MUCH WARMER READINGS WELL INTO THE 60S...SOME 15
DEGREES HIGHER THAN THE METS IN SOME CASES.
IF LOW CLOUDS WERE TO BACK IN (OR NEVER BURN OFF) THE MET VALUES
WOULD BE MORE CORRECT. HOWEVER...SINCE WE ARE BANKING ON MORE
SUNSHINE...LEANED WITH (BUT NOT QUITE ALL THE WAY) THE WARMER MAV
GUIDANCE. THIS WOULD TRANSLATE TO HIGHS MAINLY IN THE 60S ON
SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
WHILE CONFIDENCE REMAINS ABOVE NORMAL FOR UNSEASONABLY MILD
TEMPERATURES DURING THIS LONG TERM PERIOD OF THE FORECAST...AS
DISCUSSED THIS TIME YESTERDAY...THERE REMAINS CAVEATS THAT COULD
DISRUPT TRANQUIL CONDITIONS.
LATEST GLOBAL MODEL TRENDS CONTINUE TO SUPPORT A TRANQUIL END TO THE
WEEKEND AS BOTH THE SURFACE RIDGE AND POSITIVE HEIGHT ANOMALIES
ALOFT ARE EXPECTED TO BE OVER THE MID ATLANTIC AND NORTHEAST.
THEREAFTER...WE TURN UPSTREAM AS THE COMBINATION OF INCREASED
INSTABILITY AND SHORT WAVE TIMING BECOME INCREASINGLY MORE
PROBLEMATIC.
GFS/ECMWF ARE IN SOME AGREEMENT WITH AN MCS-LIKE FEATURE DEVELOPING
OVER THE MID MISSISSIPPI RIVER VALLEY DURING THIS WEEKEND. THIS MCV
PROPAGATES NORTHWARD ALONG THE BACKSIDE OF THIS DEVELOPING RIDGE
AXIS ALONG THE EASTERN SEABOARD. THIS MCV ATTEMPTS TO FIND A
WEAKNESS IN THE RIDGE AND MOVES ACROSS THE REGION LATE SUNDAY INTO
MONDAY. THIS MAY DISRUPT THE FULL INSOLATION AND KEEP TEMPERATURES
DOWN A LITTLE THAN PREVIOUS FORECASTS ALONG WITH A RENEWED CHANCE
FOR CONVECTION.
BOTH THE GFS AND ECMWF NOW SUGGEST MOISTURE BECOMES TRAPPED UNDER
THOSE INCREASING HEIGHTS ALOFT FOR MORE CLOUD COVER. AS 850MB TEMPS
CLIMB AT OR ABOVE 10C...EVEN WITH THE CLOUDS...WE SHOULD BE ABLE TO
CLIMB INTO THE LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S
FOR THE HIGHER TERRAIN.
THE BEST CHANCE FOR PORTIONS OF THE REGION TO PERHAPS TOUCH THE 80
DEGREE MARK DOES APPEAR TO BE ON WEDNESDAY WITH NEAR +12C AND AN
INCREASE SOUTHERLY FLOW.
AS FOR RECORDS DURING THIS PERIOD...HERE ARE ALBANY STATS...
DATE TEMP YEAR
SUN MAR 18 65 1966
MON MAR 19 75 1894
TUE MAR 20 74 1903
WED MAR 21 78 1921
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
EXTREMELY CHALLENGING FORECAST OVERNIGHT INTO THURSDAY. LATEST
SATELLITE IMAGERY REVEALS A LOWERING STRATUS DECK TO OUR EAST THAT
IS ATTEMPTING BACK-BUILD INTO EASTERN NEW YORK. IN
ADDITION...CONVECTION HAS DEVELOPED NORTH OF LAKE ONTARIO THAT IS
WEAKENING WITH ITS FAST FORWARD SOUTHEAST PROPAGATION. GUIDANCE
NOT DOING WELL WITH RESPECT THE LOWER STRATUS DECK AS THE NAM
OFFERS AT LEAST HINTS OF THE EXPECTATIONS. AT THIS TIME...THE
HIGHER CHANCE FOR IFR CONDITIONS APPEARS TO BE AT KPOU AND KGFL
WHERE WE WILL PLACE TEMPO GROUPS AT THIS TIME AND CLOSELY MONITOR
TRENDS. KALB APPEARS TO BE OKAY WITH JUST AN INCREASE IN THE AC
DECK OVERNIGHT.
DURING THURSDAY...CLOUDS WILL THICKEN AND LOWER ALONG WITH THE
CHANCE FOR SHOWERS /MAINLY NORTH OF KPOU/. WE WILL PLACE A
DOMINATE MVFR CATEGORY WITH CIGS AND PLACE A VCSH DUE TO
CONFIDENCE LEVELS AT THE PRESENT TIME.
NORTH-NORTHWEST WINDS AT LESS THAN 10 KT THIS EARLY MORNING...THEN
SOUTHEAST TO SOUTH AT LESS THAN 10 KT THURSDAY DAYLIGHT HOURS.
OUTLOOK...
THU NIGHT...MVFR/IFR...-SHRA LIKELY. ISOLD -TSRA.
FRI-FRI NIGHT...MVFR...SCT-NUMEROUS -SHRA AND ISOLD -TSRA EARLY.
SAT-SUN...VFR. NO SIG WX.
SUN NIGHT-MON...MAINLY VFR. SLIGHT CHC -SHRA/-TSRA.
&&
.FIRE WEATHER...
RH VALUES WILL REMAIN HIGHER THAN YESTERDAY...BOTTOMING IN THE
MODERATE RANGE (40-60 PERCENT). 10 METER WINDS WILL BE SOUTH OR
SOUTHEAST GENERALLY AROUND 10 MPH OR LESS. THERE WILL ISOLATED
SHOWERS AND POSSIBLY A THUNDERSTORM THIS MORNING AND POSSIBLY BY
LATE IN THE DAY. MOST OF THE DAY WILL BE RAINFREE AND ANY RAINFALL
WILL AVERAGE WELL BELOW A QUARTER OF AN INCH.
THERE WILL BE MORE CLOUDS THAN WEDNESDAY BUT ALSO TIMES OF
SUNSHINE...ESPECIALLY MIDDAY.
SHOWERS WILL BECOME MORE LIKELY LATER TONIGHT AND FRIDAY AS A
DISTURBANCE AND ELEVATED WARM FRONT MOVE ACROSS THE REGION. A
QUARTER OF AN INCH OF RAIN OR MORE IS POSSIBLE...ESPECIALLY NORTH
AND WEST OF ALBANY. RH LEVELS WILL REMAIN ELEVATED ON FRIDAY
(GENERALLY HIGHER THAN 60 PERCENT).
DRY WEATHER RETURNS FRIDAY NIGHT INTO THE WEEKEND. IT WILL BECOME
UNSEASONABLY WARM WITH SOME SUNSHINE EXPECTED BOTH WEEKEND DAYS.
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE NEXT MONDAY.
&&
.HYDROLOGY...
NO HYDROLOGIC ISSUES ARE ANTICIPATED OVER THE NEXT 5 DAYS.
ISOLATED SHOWERS AND THUNDERSTORMS SHOULD HAVE NO EFFECT ON RUNOFF.
IN FACT...IN SOME CASES THE PRECIPITATION MIGHT FALL AS FREEZING
RAIN (ALBEIT VERY LIGHT).
MORE SHOWER ACTIVITY IS LIKELY TONIGHT INTO EARLY FRIDAY. AT THIS
POINT RAINFALL AMOUNTS LOOK FAIRLY LIGHT...PERHAPS APPROACHING HALF
AN INCH IN OUR NORTHWESTERN ZONES...BUT GENERALLY AROUND A QUARTER
OF AN INCH OR LESS THROUGH THE REMAINDER OF OUR HYDROLOGICAL
FORECAST AREA.
THIS RAINFALL COULD PRODUCE WELL WITHIN BANK RISES ON SOME STREAMS
AND RIVERS...ESPECIALLY THOSE NORTHWEST OF ALBANY.
THE LATEST NOHRSC MODELED SNOW COVERAGE CONTINUES TO SHOW SEVERAL
INCHES OF WATER EQUIVALENT ACROSS THE ADIRONDACKS AND GREEN
MOUNTAINS. ALTHOUGH NOT MODELED...SOME SMALL AMOUNTS OF SNOW ARE
STILL PROBABLY IN PLACE ACROSS THE HIGHEST ELEVATIONS OF THE
BERKSHIRES...AND HIGH PEAKS OF THE CATSKILLS IN GREENE AND ULSTER
COUNTIES. WARM TEMPERATURES DURING THE DAYTIME HOURS OVER THE NEXT
SEVERAL DAYS...ESPECIALLY THIS WEEKEND...WILL ALLOW FOR CONTINUED
SNOW MELT...ALTHOUGH RATES SHOULD SLOW DOWN AT NIGHT WITH
TEMPERATURES DROPPING INTO THE 30S TO LOW 40S ACROSS THE HIGH
TERRAIN. BECAUSE OF THIS GRADUAL MELTING...AND NO HEAVY
PRECIPITATION EXPECTED ANYTIME SOON...NO RIVER PROBLEMS ARE
ANTICIPATED...AND THE SHORT-TERM HYDROLOGIC ENSEMBLE SHOWS NO RIVERS
IN OUR AREA EVEN REACHING ACTION STAGE OVER THE NEXT SEVERAL DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...FRUGIS/HWJIV
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
530 AM EDT THU MAR 15 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL BRING ISOLATED SHOWERS AND PERHAPS A
THUNDERSTORM TO AREAS MAINLY NORTH AND WEST OF ALBANY THIS MORNING.
THEN AFTER A BREAK IN THE ACTION...A STRONGER DISTURBANCE...LINKED
WITH A MID LEVEL WARM FRONT...WILL BRING A BETTER CHANCE OF SHOWERS
AND ANOTHER THUNDERSTORM LATER TONIGHT INTO FRIDAY. HIGH PRESSURE
WILL SLOWLY BUILD IN FRIDAY NIGHT INTO SATURDAY BRING DRIER
CONDITIONS ALONG WITH VERY MILD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 530 AM...SHOWERS AND ISOLATED THUNDERSTORMS MOVING QUICKLY
INTO THE MOHAWK VALLEY. THE 06Z NAM HAD ABSOLUTELY NO EVIDENCE OF
THEM ON THE PLANAR VIEW. THE LATEST HRRR AND RUC HAD FORECASTED SOME
ACTIVITY BUT IN THE WRONG PLACES AND WRONG TIMES.
THIS SHORT-WAVE...POORLY FORECASTED BY THE MODELS...HAS BEEN
RE-TOOLED IN GFE. WE ARE THINKING IT WILL WEAKEN AS IT MOVES AWAY
FROM ITS THETA-E SOURCE BUT STILL CARRY ISOLATED ACTIVITY PAST THE
GREATER CAPITAL DISTRICT THROUGH AT LEAST EARLY MORNING. THIS
ACTIVITY NOW STRETCHES BACK BEYOND LAKE ONTARIO SO WE MIGHT HAVE TO
EXTEND IT EVEN FURTHER INTO THE MORNING.
TEMPERATURES THIS MORNING WERE GENERALLY COLDER THIS MORNING THAN
PAST MORNING...AND IN SOME CASES...BELOW FREEZING (LIKE GLENS
FALLS). CONCERN IS THAT WITH SHOWERS MOVING INTO THESE REGIONS THERE
IS A REMOTE POSSIBILITY THAT FREEZING RAIN COULD FALL. WE WILL
MONITOR AND ISSUE MORE SPECIAL WEATHER STATEMENTS AS NEEDED.
AFTER THE DISTURBANCE MOVES THROUGH LATER THIS MORNING...IT LOOKS
DRY THROUGH MUCH OF THE AFTERNOON. HOWEVER... A STRONGER DISTURBANCE
EVIDENT ON THE H20 LP OVER THE NORTHWESTERN GREAT LAKES WILL HEAD
TOWARD OUR REGION...BUT NOT UNTIL VERY LATE IN THE DAY OR MORE
LIKELY...EVENING.
THE 11U-3.9U INDICATES THE STRATUS HAS NOT MADE MUCH PROGRESS
NORTHWARD OF LONG ISLAND WHILE AC AHEAD OF THE SHOWERS AND
THUNDERSTORMS WERE WORKING ACROSS THE MOHAWK VALLEY.
ONCE CLOUDS ASSOCIATED WITH THE DISTURBANCE MOVES ON BY TO OUR
SOUTHEAST LATER TODAY...SOME SUNSHINE IS EXPECTED BEFORE CLOUDS TEND
TO INCREASE LATER THIS MORNING BEFORE THE NEXT BATCH OF CLOUDS ROLL
IN.
WE EXPECT HIGH TEMPERATURES SOMEWHAT SIMILAR TO WEDNESDAY/S
GENERALLY IN THE 50S. THE MID HUDSON VALLEY AND LOWER LITCHFIELD
AREA WILL BE COOLER THAN YESTERDAY AS THE WIND FLOW WILL BE
SOUTHEAST...SO THEREFORE NO BENEFICIAL DOWNSLOPE WILL ENSUE OFF THE
CATSKILLS...TOPPING OUT AROUND 60.
ONCE AGAIN HOWEVER...THESE VALUES WILL BE RUNNING AT LEAST 10
DEGREES ABOVE NORMAL FOR MID MARCH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT INTO FRIDAY AFTERNOON...THE AFOREMENTIONED SHORTWAVE ALONG
WITH IT/S WEAK SFC LOW REFLECTION WILL BE MOVING FROM THE GREAT
LAKES SOUTHEASTWARD TOWARDS UPSTATE NY. THIS WILL ALLOW FOR LIKELY
SHOWERS AND THE CHANCE OF THUNDERSTORMS ACROSS OUR AREA...MAINLY
OVERNIGHT. SHOWALTER VALUES CONTINUE SLIGHTLY NEGATIVE...AND MIXED
LAYER MUCAPE VALUES RANGE BETWEEN 0 AND 400 J/KG. WHILE THERE MAY BE
A FEW RUMBLES OF THUNDER AROUND...AND 850-500 HPA LAPSE RATES WILL
BE AROUND 6.5 DEGREES C/KM...IT/S UNLIKELY ANY STORM WOULD BECOME
STRONG DUE TO THE RELATIVELY LOW DEWPOINT TEMPS AND MEAGER CAPE.
OVERNIGHT LOW TEMPERATURES WILL WITH THE CLOUDS AND ANTICIPATED
SHOWER ACTIVITY...OVERNIGHT LOWS WILL BE MILD TONIGHT...WITH MOST
AREAS IN THE UPPER 30S TO MID 40S. TEMPERATURES ON FRIDAY WILL BE A
LITTLE COOLER THAN RECENT DAYS...BUT STILL MILD FOR THIS TIME OF
YEAR...MAINLY IN THE MID OR UPPER 50S. (A FEW READINGS AROUND 60 IN
THE MID HUDSON VALLEY).
BY FRIDAY EVENING...THE DISTURBANCE WILL BE PASSING EAST OF THE
REGION AND A DRYING TREND WILL SET IN. AN UPPER LEVEL RIDGE OVER THE
MIDWEST WILL BUILD INTO THE AREA FOR THE OVERNIGHT
HOURS...ALLOWING THE THREAT FOR SHOWERS TO END. A SURFACE HIGH WILL
BUILDING SOUTHWARD FROM CANADA. THIS SETUP USUALLY POSES A CHALLENGE
TO HOW QUICKLY WE CLEAR OUT...AS MOISTURE COULD EASILY GET TRAPPED
UNDERNEATH AN LOWERING INVERSION. THUS FAR...MODELS ARE OPTIMISTIC
THAT CLOUDS WILL AT LEAST THIN. HOWEVER IF THEY DO...CHANCES FOR FOG
WILL INCREASE. FOR NOW...WENT PARTLY CLOUDY WITH PATCHY FOG.
ASSUMING THIS MIDDLE OF THE ROAD SCENARIO...TEMPERATURES WILL DIP TO
THE MID 30S TO LOWER 40S. IF CLOUDS WERE TO PERSIST...OVERNIGHT LOWS
WOULD BE A LITTLE MILDER. ON THE OTHER HAND...IF WE WERE TO CLEAR
MORE QUICKLY...READINGS COULD DIP A BIT LOWER...ALLOWING MORE
EXTENSIVE FOG TO POSSIBLY FORM.
SATURDAY...HIGH TEMPERATURES WILL TRICKY TO FORECAST. WE ASSUME A
GOOD DEAL OF SUNSHINE. HOWEVER...THE MEAN AIR FLOW WILL BE SSE (AS
OPPOSED TO SSW) SO THERE COULD BE LINGERING MARINE INFLUENCES. THE
MET GUIDANCE (OFF THE NAM MODEL) INDICATED TEMPERATURES ONLY
REACHING THE 50S ON SATURDAY WHILE THE MAV GUIDANCE (BASED OFF THE
GFS MODEL) INDICATE MUCH WARMER READINGS WELL INTO THE 60S...SOME 15
DEGREES HIGHER THAN THE METS IN SOME CASES.
IF LOW CLOUDS WERE TO BACK IN (OR NEVER BURN OFF) THE MET VALUES
WOULD BE MORE CORRECT. HOWEVER...SINCE WE ARE BANKING ON MORE
SUNSHINE...LEANED WITH (BUT NOT QUITE ALL THE WAY) THE WARMER MAV
GUIDANCE. THIS WOULD TRANSLATE TO HIGHS MAINLY IN THE 60S ON
SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
WHILE CONFIDENCE REMAINS ABOVE NORMAL FOR UNSEASONABLY MILD
TEMPERATURES DURING THIS LONG TERM PERIOD OF THE FORECAST...AS
DISCUSSED THIS TIME YESTERDAY...THERE REMAINS CAVEATS THAT COULD
DISRUPT TRANQUIL CONDITIONS.
LATEST GLOBAL MODEL TRENDS CONTINUE TO SUPPORT A TRANQUIL END TO THE
WEEKEND AS BOTH THE SURFACE RIDGE AND POSITIVE HEIGHT ANOMALIES
ALOFT ARE EXPECTED TO BE OVER THE MID ATLANTIC AND NORTHEAST.
THEREAFTER...WE TURN UPSTREAM AS THE COMBINATION OF INCREASED
INSTABILITY AND SHORT WAVE TIMING BECOME INCREASINGLY MORE
PROBLEMATIC.
GFS/ECMWF ARE IN SOME AGREEMENT WITH AN MCS-LIKE FEATURE DEVELOPING
OVER THE MID MISSISSIPPI RIVER VALLEY DURING THIS WEEKEND. THIS MCV
PROPAGATES NORTHWARD ALONG THE BACKSIDE OF THIS DEVELOPING RIDGE
AXIS ALONG THE EASTERN SEABOARD. THIS MCV ATTEMPTS TO FIND A
WEAKNESS IN THE RIDGE AND MOVES ACROSS THE REGION LATE SUNDAY INTO
MONDAY. THIS MAY DISRUPT THE FULL INSOLATION AND KEEP TEMPERATURES
DOWN A LITTLE THAN PREVIOUS FORECASTS ALONG WITH A RENEWED CHANCE
FOR CONVECTION.
BOTH THE GFS AND ECMWF NOW SUGGEST MOISTURE BECOMES TRAPPED UNDER
THOSE INCREASING HEIGHTS ALOFT FOR MORE CLOUD COVER. AS 850MB TEMPS
CLIMB AT OR ABOVE 10C...EVEN WITH THE CLOUDS...WE SHOULD BE ABLE TO
CLIMB INTO THE LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S
FOR THE HIGHER TERRAIN.
THE BEST CHANCE FOR PORTIONS OF THE REGION TO PERHAPS TOUCH THE 80
DEGREE MARK DOES APPEAR TO BE ON WEDNESDAY WITH NEAR +12C AND AN
INCREASE SOUTHERLY FLOW.
AS FOR RECORDS DURING THIS PERIOD...HERE ARE ALBANY STATS...
DATE TEMP YEAR
SUN MAR 18 65 1966
MON MAR 19 75 1894
TUE MAR 20 74 1903
WED MAR 21 78 1921
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
EXTREMELY CHALLENGING FORECAST OVERNIGHT INTO THURSDAY. LATEST
SATELLITE IMAGERY REVEALS A LOWERING STRATUS DECK TO OUR EAST THAT
IS ATTEMPTING BACK-BUILD INTO EASTERN NEW YORK. IN
ADDITION...CONVECTION HAS DEVELOPED NORTH OF LAKE ONTARIO THAT IS
WEAKENING WITH ITS FAST FORWARD SOUTHEAST PROPAGATION. GUIDANCE
NOT DOING WELL WITH RESPECT THE LOWER STRATUS DECK AS THE NAM
OFFERS AT LEAST HINTS OF THE EXPECTATIONS. AT THIS TIME...THE
HIGHER CHANCE FOR IFR CONDITIONS APPEARS TO BE AT KPOU AND KGFL
WHERE WE WILL PLACE TEMPO GROUPS AT THIS TIME AND CLOSELY MONITOR
TRENDS. KALB APPEARS TO BE OKAY WITH JUST AN INCREASE IN THE AC
DECK OVERNIGHT.
DURING THURSDAY...CLOUDS WILL THICKEN AND LOWER ALONG WITH THE
CHANCE FOR SHOWERS /MAINLY NORTH OF KPOU/. WE WILL PLACE A
DOMINATE MVFR CATEGORY WITH CIGS AND PLACE A VCSH DUE TO
CONFIDENCE LEVELS AT THE PRESENT TIME.
NORTH-NORTHWEST WINDS AT LESS THAN 10 KT THIS EARLY MORNING...THEN
SOUTHEAST TO SOUTH AT LESS THAN 10 KT THURSDAY DAYLIGHT HOURS.
OUTLOOK...
THU NIGHT...MVFR/IFR...-SHRA LIKELY. ISOLD -TSRA.
FRI-FRI NIGHT...MVFR...SCT-NUMEROUS -SHRA AND ISOLD -TSRA EARLY.
SAT-SUN...VFR. NO SIG WX.
SUN NIGHT-MON...MAINLY VFR. SLIGHT CHC -SHRA/-TSRA.
&&
.FIRE WEATHER...
RH VALUES WILL REMAIN HIGHER THAN YESTERDAY...BOTTOMING IN THE
MODERATE RANGE (40-60 PERCENT). 10 METER WINDS WILL BE SOUTH OR
SOUTHEAST GENERALLY AROUND 10 MPH OR LESS. THERE WILL ISOLATED
SHOWERS AND POSSIBLY A THUNDERSTORM THIS MORNING AND POSSIBLY BY
LATE IN THE DAY. MOST OF THE DAY WILL BE RAINFREE AND ANY RAINFALL
WILL AVERAGE WELL BELOW A QUARTER OF AN INCH.
THERE WILL BE MORE CLOUDS THAN WEDNESDAY BUT ALSO TIMES OF
SUNSHINE...ESPECIALLY MIDDAY.
SHOWERS WILL BECOME MORE LIKELY LATER TONIGHT AND FRIDAY AS A
DISTURBANCE AND ELEVATED WARM FRONT MOVE ACROSS THE REGION. A
QUARTER OF AN INCH OF RAIN OR MORE IS POSSIBLE...ESPECIALLY NORTH
AND WEST OF ALBANY. RH LEVELS WILL REMAIN ELEVATED ON FRIDAY
(GENERALLY HIGHER THAN 60 PERCENT).
DRY WEATHER RETURNS FRIDAY NIGHT INTO THE WEEKEND. IT WILL BECOME
UNSEASONABLY WARM WITH SOME SUNSHINE EXPECTED BOTH WEEKEND DAYS.
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE NEXT MONDAY.
&&
.HYDROLOGY...
NO HYDROLOGIC ISSUES ARE ANTICIPATED OVER THE NEXT 5 DAYS.
ISOLATED SHOWERS AND THUNDERSTORMS SHOULD HAVE NO EFFECT ON RUNOFF.
IN FACT...IN SOME CASES THE PRECIPITATION MIGHT FALL AS FREEZING
RAIN (ALBEIT VERY LIGHT).
MORE SHOWER ACTIVITY IS LIKELY TONIGHT INTO EARLY FRIDAY. AT THIS
POINT RAINFALL AMOUNTS LOOK FAIRLY LIGHT...PERHAPS APPROACHING HALF
AN INCH IN OUR NORTHWESTERN ZONES...BUT GENERALLY AROUND A QUARTER
OF AN INCH OR LESS THROUGH THE REMAINDER OF OUR HYDROLOGICAL
FORECAST AREA.
THIS RAINFALL COULD PRODUCE WELL WITHIN BANK RISES ON SOME STREAMS
AND RIVERS...ESPECIALLY THOSE NORTHWEST OF ALBANY.
THE LATEST NOHRSC MODELED SNOW COVERAGE CONTINUES TO SHOW SEVERAL
INCHES OF WATER EQUIVALENT ACROSS THE ADIRONDACKS AND GREEN
MOUNTAINS. ALTHOUGH NOT MODELED...SOME SMALL AMOUNTS OF SNOW ARE
STILL PROBABLY IN PLACE ACROSS THE HIGHEST ELEVATIONS OF THE
BERKSHIRES...AND HIGH PEAKS OF THE CATSKILLS IN GREENE AND ULSTER
COUNTIES. WARM TEMPERATURES DURING THE DAYTIME HOURS OVER THE NEXT
SEVERAL DAYS...ESPECIALLY THIS WEEKEND...WILL ALLOW FOR CONTINUED
SNOW MELT...ALTHOUGH RATES SHOULD SLOW DOWN AT NIGHT WITH
TEMPERATURES DROPPING INTO THE 30S TO LOW 40S ACROSS THE HIGH
TERRAIN. BECAUSE OF THIS GRADUAL MELTING...AND NO HEAVY
PRECIPITATION EXPECTED ANYTIME SOON...NO RIVER PROBLEMS ARE
ANTICIPATED...AND THE SHORT-TERM HYDROLOGIC ENSEMBLE SHOWS NO RIVERS
IN OUR AREA EVEN REACHING ACTION STAGE OVER THE NEXT SEVERAL DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...FRUGIS/HWJIV
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1153 PM CDT WED MAR 14 2012
.DISCUSSION...
ISSUED 904 PM CDT WED MAR 14 2012
MADE A FEW MINOR ADJUSTMENTS TO THE FORECAST FOR SKY COVER AND
PRECIPITATION CHANCES OVERNIGHT. THE LATEST SATELLITE LOOP SHOWS A
FEW LOW CLOUDS IN CENTRAL IL...WITH CONVECTIVE DEBRIS CLOUDS IN
SOUTHEAST IL. MAINLY CLEAR SKIES WILL BE THE RULE EARLY TONIGHT AS
THE CONVECTIVE DEBRIS MOVES OUT OF THE AREA. SCATTERED MID AND
THEN LOW CLOUDS WILL INCREASE IN AREAS NORTHWEST OF THE IL RIVER
OVERNIGHT AS A WEAK SURFACE BOUNDARY MOVES TOWARD NW IL. THE
LATEST WRF AND HRRR MODELS INDICATE SOME LIGHT SHOWERS MAY
ACCOMPANY THE CLOUDS IN NORTH CENTRAL IL...SO WILL KEEP AT LEAST A
20 POP IN THE OVERNIGHT FORECAST.
WILL KEEP THE CHANCE POPS IN SOUTHEAST IL SINCE HIGH INSTABILITY
AIR IS IN PLACE WITH CAPES OF 2000-2500 AND WEAK UPPER LEVEL
FORCING COULD PRODUCE SCATTERED T-STORMS TONIGHT.
WITH UNSEASONABLY MILD DEW POINTS IN THE UPPER 50S TO LOWER 60S...
OVERNIGHT LOWS WILL ONLY DIP INTO THE LOWER 60S...WHICH THE
PREVIOUS FORECAST HAS A GOOD HANDLE ON.
&&
.AVIATION...
ISSUED 1154 PM CDT WED MAR 14 2012
ALL OF CENTRAL ILLINOIS WILL REMAIN IN THE UNSEASONABLY WARM AND
HUMID AIRMASS THROUGH THE NEXT 24 HOURS...AND FOR SEVERAL DAYS
BEYOND. THIS WILL RESULT IN PERIODIC CHANCES FOR ISOLATED
THUNDERSTORMS EARLY THIS MORNING AND AGAIN DURING THE AFTERNOON
AND EARLY EVENING THURSDAY. THE MOST LIKELY AREA TO SEE A FEW
T-STORMS EARLY THIS MORNING WILL BE IN THE VICINITY OF KPIA
BECAUSE OF LOW LEVEL CONVERGENCE FOCUSING IN THIS REGION.
ALL OF CENTRAL ILLINOIS WILL SEE A BREAK IN THE CONVECTIVE CLOUD
DEBRIS AFTER 10Z...RESULTING IN THE DEVELOPMENT OF LIGHT FOG AND
MVFR VISIBILITY.
IT WILL BE DIFFICULT TO PINPOINT EXACTLY WHERE CONVECTION WILL
FIRE UP DURING THE AFTERNOON AND EARLY EVENING IN CENTRAL IL
THURSDAY BECAUSE OF THE LACK OF A GOOD FOCUSING BOUNDARY AND WEAK
UPPER SUPPORT...DESPITE ADEQUATE INSTABILITY. AS A RESULT...WILL
MENTION CB IN THE TAFS FOR MOST TAF SITES UP UNTIL 00Z.
MILLER
&&
.PREV DISCUSSION...
ISSUED 252 PM CDT WED MAR 14 2012
18Z SFC MAP SHOWED A LATE SPRING PATTERN IN PLACE AS SOUTHWEST WINDS
GUSTING UP TO 30 MPH AHEAD OF A COLD FRONT IN WESTERN
IOWA...HELPED BOOST TEMPERATURES TO RECORD LEVELS THE UPPER
70S AND LOWER 80S. SEVERAL DAYS OF SUSTAINED SOUTHERLY FLOW HAS
ALLOWED DEWPOINTS TO CLIMB TO UNSEASONABLY HIGH LEVELS IN THE
LOWER 60S. ALOFT...BROAD WEST-SOUTHWEST MID LEVEL FLOW FEATURED
SEVERAL WEAK EMBEDDED SHORTWAVES WHICH WILL BE THE FOCUS FOR
THUNDERSTORM CHANCES THE NEXT FEW DAYS.
SHORT TERM...TONIGHT THROUGH THURSDAY
POTENTIAL CONVECTION FOR THE SOUTHEAST HALF OF THE AREA LATE THIS
AFTERNOON AND EVENING IS FIRST FORECAST CONCERN. WARM AND HUMID
BOUNDARY LAYER COMBINED WITH STEEP MID LEVEL LAPSE RATES AND
INCREASING MOISTURE ADVECTION BELOW 800 MB HAVE LED TO AN UNCAPPED
ATMOSPHERE WITH SURFACE BASED CAPES OF 2500-3000 J/KG. INCREASING
DPVA AHEAD OF A WEAK SHORTWAVE LIFTING NE OUT OF OKLAHOMA SHOULD
LEAD TO AN INCREASE IN CONVECTION ACROSS SOUTHEAST MISSOURI AND
SOUTHERN ILLINOIS OVER THE NEXT COUPLE HOURS. WIND FIELDS ALOFT
ARE UNCHARACTERISTICALLY WEAK FOR EARLY SPRING...WITH 0-6 KM
EFFECTIVE SHEAR ONLY 25 KTS. THIS SHOULD LEAD TO A
DISORGANIZED/PULSE TYPE THUNDERSTORM MODE AND EVEN WITH HIGH
INSTABILITY WOULD ONLY EXPECT SOME NEAR SVR WIND GUSTS AND HAIL
PRIMARILY IN A 3PM-7PM WINDOW...AND BEST CHANCES SOUTH OF I-70. THIS
THINKING IS SUPPORTED BY LATEST RUN HIGH-RES HRRR AND WRF-NMM
MODEL RUNS...WITH ANY CONVECTION PUSHING INTO INDIANA AFTER 7 OR 8
PM.
THE NEXT FOCUS FOR THUNDERSTORM DEVELOPMENT LOOKS TO BE
AHEAD OF THE COLD FRONT TO OUR NORTHWEST. ISOLATED TO SCATTERED
ELEVATED STORMS SHOULD FORM LATER THIS EVENING NEAR OR EAST OF THE
MISSISSIPPI RIVER AS 30-35 KT WSW ORIENTED LOW LEVEL JET DEVELOPS.
DUE TO LIMITED INSTABILITY SEVERE STORMS ARE NOT EXPECTED WITH
THIS ACTIVITY AS IT DROPS SOUTHEAST OVERNIGHT.
THE COLD FRONT WILL BECOME ALIGNED WITH THE UPPER LEVEL FLOW ON
THURSDAY AND TEND TO PUSH MORE EAST THAN SOUTH. CURRENT GUIDANCE
SUGGESTS THE FRONT WILL NOT MAKE IT INTO OUR CWA SO ANOTHER DAY
WITH HIGHS NEAR 80. ASSUMING THE FRONT STAYS TO OUR NORTH AND
WASHES OUT...ANY CONVECTION WOULD BE DRIVEN BY SUBTLE SHORTWAVE
ENERGY. HAVE MAINTAINED LOW CHC POPS DUE TO UNCERTAINTY IN
TIMING OR LOCATION OF DEVELOPMENT...BUT WITH HIGH INSTABILITY HAIL
AND GUSTY WINDS WOULD BE POSSIBLE.
LONG TERM...FRIDAY THROUGH WEDNESDAY
THE EXTENDED PORTION OF THE FORECAST WILL FEATURE AN AMPLIFIED
UPPER AIR PATTERN WITH A WESTERN TROUGH DEEPENING AS IT APPROACHES
THE ROCKIES EARLY NEXT WEEK...WHILE A STRONG RIDGE BUILDS ACROSS
THE EASTERN THIRD OF THE COUNTRY. THIS WILL KEEP THE LOCAL AREA
BATHED IN SOUTHERLY FLOW AND TEMPERATURES MORE TYPICAL OF MID TO
LATE MAY WITH HIGHS IN THE 70S TO NEAR 80 AND LOWS IN THE UPPER 50S.
DEW POINTS WILL CONTINUE TO BE UNSEASONABLY HIGH IN THE UPPER 50S
TO LOWER 60S...GIVING A SOMEWHAT HUMID FEEL TO THE AIR. THE BEST
CHANCE OF THUNDERSTORMS DURING THE PERIOD WILL BE SATURDAY WHEN A
MORE ORGANIZED SHORTWAVE LIFTS FROM THE CENTRAL PLAINS INTO THE
LOWER GREAT LAKES. HAVE TRIED TO FOCUS ANOTHER PERIOD OF HIGHER
POPS LATE IN THE EXTENDED WHEN THE UPPER TROUGH TRACKS EAST INTO
THE PLAINS. LATEST 12Z RUN GFS AND ECMWF HAVE SLOWED THIS SYSTEM
WITH AN UPPER LOW CUTTING OFF IN THE SOUTHERN OR CENTRAL PLAINS.
THIS WOULD KEEP THE AREA IN SOUTHERLY FLOW THROUGH MID WEEK WITH
EASTERN FRINGES OF A MORE UNSETTLED PATTERN APPROACHING THE
MISSISSIPPI RIVER VALLEY.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
154 AM EDT THU MAR 15 2012
.AVIATION...
06Z TAFS...ELEVATED THUNDERSTORMS HAVE BEEN ON THE INCREASE OVER
THE PAST FEW HOURS AT THE NOSE OF STRONG LOW LEVEL THEATE
ADVECTION. THIS AXIS OF FORCING HAS ORIENTED ITSELF ROUGHLY ALONG
AND EAST OF A KAZO TO KFWA LINE. WOULD SUSPECT THAT GREATER
CONVECTIVE COVERAGE WILL STAY EAST OF KFWA/KSBN THROUGH THE
REMAINDER OF THE OVERNIGHT HOURS...BUT STILL A CONCERN OF AN
ISOLATED THUNDERSTORM AFFECTING THE TERMINALS OVERNIGHT AS A WEAK
SHORT WAVE ACROSS NORTHERN ILLINOIS TRACKS INTO NORTHERN INDIANA.
PROBABILITY OF ANY TERMINAL RECEIVING TSRA IS QUITE LOW AND WILL
CONTINUE WITH CB MENTION AT THIS TIME AND MONITOR TRENDS. OTHER
CONCERN OVERNIGHT WILL BE INCREASING STRATUS/FOG POTENTIAL. STILL
FEEL THAT MORE OF A STRATUS SETUP WILL BE FAVORED BUT CONFIDENCE
REMAINS LOW ENOUGH TO KEEP CONDITIONS MVFR AT THIS TIME.
STRATUS/FOG SHOULD MIX OUT BY MID MORNING WITH GENERALLY VFR
CONDITIONS EXPECTED THROUGH THE REMAINDER OF THE PERIOD. GUSTY
SOUTHWEST WINDS TO 10 TO 20 KNOTS EXPECTED DURING THE DAY AHEAD OF
THE FRONT. ISOLATED THUNDER POSSIBLE DURING THE AFTERNOON...BUT
LACK OF STRONG FORCING PRECLUDES TAF MENTION.
&&
SHORT TERM.../TONIGHT THROUGH THURSDAY NIGHT/
MAIN FOCUS WILL BE ON CONVECTIVE CHANCES THROUGH THE PERIOD AS WELL
AS CONTINUATION OF UNSEASONABLE WARM TEMPERATURES.
AS EXPECTED...TEMPERATURES HAVE SOARED WELL INTO THE 70S THIS
AFTERNOON WITH INCREASING LL FLOW AND STRONG MIXING. ELEVATED MIXED
LAYER IS KEEPING CLOUDS AT BAY FOR THE TIME BEING ACROSS MUCH OF THE
REGION. AS WE PROGRESS INTO THIS EVENING...THIS WILL CHANGE AS NOSE
OF LL THETA E SURGE AND INCREASING ISENTROPIC LIFT MOVES ACROSS
INDIANA INTO OHIO. LOCAL WRF MOST AGGRESSIVE WITH THIS FEATURE
FORCING CONVECTION TO INITIATE BY LATE AFTERNOON TO OUR WEST AND
SWINGING IT THROUGH THE AREA THROUGH MIDNIGHT. NAM KEEP ACTIVITY
SUPPRESSED FURTHER SOUTH. MIDDLE ROAD MODELS (HRRR/4KM SPC WRF) ALSO
FOCUS BULK OF CONVECTION ACROSS CNTRL/SOUTHERN INDIANA WITH
ISOL/WIDELY SCT CONVECTION INTO PORTIONS OF NORTHERN INDIANA. VIS
SAT SHOWS EXPANDING CU FIELD ACROSS CENTRAL ILLINOIS WHERE SFC
DEWPTS WERE NOW IN THE LOWER 60S. AT 18Z...ISOLATED SHOWERS WERE
NOTED SOUTHWEST OF ST LOUIS...WITH A FEW LIGHTNING STRIKES SHOWING
UP IN THE BOOTHILL OF MISSOURI...WHICH 14-15ZZ HRRR AND 12Z 4KM SPC
WRF PLACED PERFECTLY...WITH NAM SHOWING NO DEVELOPMENT. THE
LIGHTNING STRIKES WERE NOTED ON NOSE OF MID 60 DEWPTS. AM INCLINED
TO LEAN TOWARDS THESE MODELS AND THEIR TRENDS...WHICH BLEND NICELY
WITH INHERITED GRIDS. SPC HAS CONFINED SLGT RISK FURTHER SOUTH INTO
SOUTHERN ILLINOIS AND SW INDIANA. WILL NEED TO MONITOR CONVECTIVE
DEVELOPMENT INTO THIS EVENING WITH RISK OF STRONG STORMS IN PLACE.
WITH THE INCREASE IN LL MSTR...GRIDS NEEDED TO BE PATCHED UP TO
INCREASE OVERNIGHT LOWS CLOSER TO 60...AS WELL AS SUBSEQUENT
INCREASING IN DEWPTS. FOG POTENTIAL STILL LOOMS LATER TONIGHT AS
WEAK BOUNDARY SLIDES SOUTH TOWARDS THE AREA. HOWEVER...WITH
POTENTIAL OF EVENING CONVECTION AND CHANCES IT COULD MESS UP LL
PROFILES...WILL NOT MAKE ANY CHANGES IN REGARDS TO PREV INSERTION OF
FOG.
BOUNDARY WILL STALL OUT ACROSS THE AREA THURSDAY INTO THURSDAY
EVENING PUSHING SOUTHWARD. THIS WILL CAUSE NUMEROUS ISSUES WITH THE
FORECAST WITH POTENTIAL FOR WIDESPREAD CLOUD COVER...POSSIBLY FOG
AND CHANCES FOR SHOWERS AND STORMS. BROADBRUSHED APPROACH BEST
OPTION AT THIS POINT WITH DECREASE IN POPS IN NW AREAS BY THURS NGT
AS DRIER AIR TRIES TO FILTER IN. CAN`T REALLY ADD MUCH DETAIL TO
GRIDS AT THIS POINT WITH SEVERAL SCENARIOS POSSIBLE. UNSEASONABLY
WARM TEMPS WILL STILL BE IN STORE WITH HIGHS INTO THE 70S.
&&
LONG TERM...
FEW CHANGES TO LONG TERM GRIDS WITH CRALLBLEND INIT IN BALLPARK.
UNSEASONABLY WARM PATTERN CONTINUES THROUGH THE PERIOD WITH DEEP
TROUGH DEVELOPING IN THE WEST AND STAUNCH RIDGE FOR LATE MARCH
DEVELOPING OVER THE MIDWEST. MEDIUM RANGE MODELS HAVE DIFFERENCES IN
THE DETAILS AS EXPECTED WITH NUMEROUS SHORT WAVES AND ABUNDANT
MOISTURE. PWATS STILL EXPECTED ABOVE AN INCH THROUGH THE PERIOD WITH
SURFACE DEWPOINTS IN THE 50S AND POOLING INTO 60S AT TIMES. THIS
WILL SET STAGE FOR PERIODS OF SHOWERS AND THUNDERSTORMS DEPENDENT ON
TIMING OF EACH WAVE. SHEAR PROFILES REMAIN WEAK WHILE MUCAPES ABOVE
2000 J/KG AT TIMES SO ISOLATED SEVERE STORMS REMAIN A POSSIBILITY.
TEMPERATURES WILL REMAIN 20 TO 25 DEGREES ABOVE NORMAL THROUGH END
OF PERIOD...POSSIBLY HIGHER NEXT WEEK DEPENDING ON DEGREE OF CLOUD
COVER. HIGHS IN THE 80S REMAIN A POSSIBILITY IF FULL MIXING CAN BE
ACHIEVED NEXT WEEK. WITH SUCH A DEEP SYSTEM TO THE WEST FEEL MODELS
ARE TOO FAST WITH APPROACH OF TROUGH FOR MIDDLE OF NEXT WEEK AND
THUS WED WILL CONTINUE TO BE WARM. RAISED ALLBLEND INIT TEMPS
SEVERAL DEGREES IN LINE WITH DAY 5 AND 6 TEMPS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...FISHER
LONG TERM...LASHLEY
AVIATION...MARSILI
AREA FORECAST DISCUSSION
NWS CARIBOU ME
211 AM EDT THU MAR 15 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK SLOWLY EAST OF THE REGION OVERNIGHT. HIGH
PRESSURE WILL BUILD BRIEFLY INTO THE AREA LATER THURSDAY. A WEAK
TROUGH OF LOW PRESSURE WILL APPROACH FROM THE WEST ON FRIDAY AND
CROSS THE STATE LATE FRIDAY AND FRIDAY NIGHT. HIGH PRESSURE WILL
REBUILD INTO THE AREA OVER THE WEEKEND WITH AN UNSEASONABLY WARM
WEATHER PATTERN SHAPING UP FOR NEXT WEEK.&&
.NEAR TERM /THROUGH TODAY/...
UPDATE: SNOW CONTS ACROSS NE AND E CENTRAL AREAS BUT HAS BEGUN TO LIGHTEN
UP AND THIS TREND WILL CONT OVR THE NEXT SEVERAL HRS BEFORE ENDING
ERLY THU AM. HAVE ALLOWED THE REMAINING ADV AND THE WNTR STORM
WRNG TO EXPIRE.
UPDATE: GOOD DEFORMATION AXIS CONTS ATTM ACROSS NE AND E CENTRAL
AREAS. PER LATEST TRENDS...RAISED SNOW AMOUNTS ACROSS ERN SECTIONS
A BIT MORE AND ADJUSTED POPS. ALLOWED WRN ADVS TO EXPIRE AND XTND
ERN ADVS TIL 2 AM. CURRENT WRNG FOR ZN2 CONTS TIL 2 AM AND COULD
SEE SOME LOCALIZED ACCUMS UP TO A FOOT ACROSS ERN SECTIONS WHEN
ALL IS SAID AND DONE.
UPDATE 2: BASED ON LATEST SPOTTER SNOW REPORTS RECEIVED FROM THE
CARIBOU...FORT FAIRFIELD...PRESQUE ISLE AREA WHICH WERE UP TO 7 TO
8 INCHES AND LATEST MESO-MODEL GUIDANCE...INCLUDING THE 18Z NAM
AND 21Z HRRR MODELS THAT NOW KEEP THE BAND ORIGINATING FROM SRN
NB AIMED TOWARD NE ME OVR THE SAME RELATIVE AREA FOR THE NEXT FEW
HRS; IT APPEARS IMMINENT THAT SOME LOCATIONS COULD EXPERIENCE A
STORM TOTAL UP TO OR JUST OVER 10 INCHES...WITH THE HIGHEST
AMOUNTS CLUSTERED NEAR THE NB BORDER BOUNDED BY LIMESTONE...
CARIBOU...PRESQUE ISLE AND MARS HILL. INDEED...THE AMOUNT OF AREA
TO BE AFFECTED BY HEAVY SN ACCUMULATIONS WITHIN NE AROOSTOOK
COUNTY IS LESS THAN 50 PERCENT OF ZONE 2...BUT IS AFFECTING THE
MOST URBAN AREAS THE MOST. RADAR INDICATES ONE LAST PULSE (PERHAPS
THE LAST) OF MDT TO HVY SN WITH THIS BAND TAKING AIM TOWARD THE
WRNG AREA...SO SNFL RATES UP TO AN INCH AN HR AT TIMES OVR SOME
AREAS CAN BE XPCTD UNTIL MDNGT OR SO BEFORE SN RATES WIND DOWN.
WITH DEEP ELEVATED WARM ADVCN WEAKENING IN THE TROWAL ZONE XTNDG
TOWARD E ME DURG THE LATE NGT/ERLY MORN HRS...ANY REMAINING
ORGANIZED SNFL SHOULD QUICKLY WIND DOWN OVR THE FA AS THE UPPER
LOW BEGINS TO MOVE INTO SRN NB.
UPDATE 1: SENT A QUICK UPDATE TO INCREASE TOTAL SNFL AMOUNTS
TO 4 TO 8 IN ACROSS PORTIONS OF NERN AND FAR NRN AROOSTOOK COUNTY
BASED ON A FEW OBS OF 5 IN ATTM. SOME UNCERTAINTY EXISTS REGARDING
HOW BANDING WILL EVOLVE OVR THE NEXT FEW HRS...WITH NEAR TERM
MODELS SUCH AS THE HRRR SHOWING THE ENHANCED BANDING CURRENTLY
JUST W OF THE ME-NB BORDER POSSIBLY GRAZING FAR NE AROOSTOOK
COUNTY. WILL MONITOR CLOSELY DURG THIS TM.
ORGNL DISC: UPPER LOW TRACKING TOWARDS THE WESTERN BORDER OF
MAINE AS EXPECTED. SOME INSTABILITY ABOVE H850 AND A SHARP UPPER
TROUGH ROTATING AROUND THE CLOSED UPPER LOW IS PRODUCING LOCALLY
HEAVIER SNOW SHOWERS IN FAR NORTHEASTERN ZONES. WILL GO FOR UP TO
5 INCHES IN NE CORNER OF STATE...BUT EXPECT WIDE VARIATIONS FOR
NORTHERN ZONES DUE TO HIT OR MISS NATURE OF THE HEAVIER SNOW
SHOWERS. MOISTURE CONTINUES TO WRAP BACK NORTHWESTWARDS FROM THE
MARITIMES AND WILL HELP PROLONG SNOW IN NORTHERN ZONES WELL INTO
THE NIGHT. DOWN EAST AREAS WILL GET A BRIEF SHOT OF SNOW THIS
EVENING THAT MAY LAY DOWN AN INCH OR SO. THIS WILL BE IN
CONJUNCTION WITH THE UPPER LOW PASSAGE. THE THREAT FOR FZDZ IS
STILL THERE WITH THE RISK FROM NEAR MILO TOWARDS NORTHERN
WASHINGTON COUNTY THIS AFTERNOON AND QUICKLY SHIFTING TO SOUTHERN
WASHINGTON COUNTY THIS EVENING BEFORE THE WARM AIR ALOFT IS GONE.
TEMPERATURES TONIGHT WILL DIP SLIGHTLY IN THE LOWER 20S NORTH AND
UPPER 20S DOWN EAST.
WITH SNOW ENDING IN THE FAR EASTERN ZONES EARLY THURSDAY
MORNING...HIGH PRESSURE WILL BUILD BUT CLOUD COVER ASSOCIATED WITH
A SUBSIDENCE INVERSION WILL BE SLOW TO ERODE FROM THE WEST. EXPECT
SOME CLEARING TOWARDS BANGOR BY AFTERNOON...BUT NOT UNTIL LATE DAY
TOWARDS THE EASTERN BORDER OF THE STATE. HIGHS WILL REACH THE LOW
TO MID 30S TOWARDS THE SJV AND INCREASE TOWARDS DOWN EAST WHERE
LOW 40S ARE LIKELY.&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL CREST THE REGION THURSDAY NIGHT AND THEN MOVE
EAST OF THE AREA EARLY FRIDAY. MODELS IN GOOD AGREEMENT WITH UPPER
TROUGH APPROACHING FROM THE WEST FRIDAY AND CROSSING THE STATE BY
FRIDAY EVENING. EXPECT ASSOCIATED LOW PRESSURE AND COLD FRONT TO
SPREAD MAINLY RAIN FROM WEST TO EAST ACROSS THE STATE FRIDAY
AFTERNOON. RAIN MAY MIX WITH SNOW ACROSS EXTREME NORTHERN
SECTIONS. THEN AS UPPER TROUGH MOVES EAST OF THE STATE, CONDITIONS
WILL IMPROVE FROM WEST TO EAST FRIDAY NIGHT. QPF AMOUNTS AT THIS
TIME APPEARS TO BE ON THE LIGHT SIDE WITH AMOUNTS GENERALLY BELOW A
QUARTER OF AN INCH. HIGH PRESSURE THEN BUILD ACROSS NEW ENGLAND ON
SATURDAY WITH CLEAR SKIES AND MODERATING TEMPERATURES INTO THE 40S
AND 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
RIDGING BUILDING ALONG THE EAST COAST WILL SET THE STAGE FOR SOME
VERY MILD WEATHER GOING INTO EARLY NEXT WEEK. HIGH PRESSURE ALONG
THE EAST COAST WILL BRING A MOSTLY CLEAR NIGHT SATURDAY NIGHT
FOLLOWED BY A PARTLY SUNNY AND MILD DAY ON SUNDAY. THE LATEST GFS
SHOWS A WEAK COLD FRONT MOVING IN LATE SUNDAY WHICH MAY BRING
INCREASING CLOUDS LATE IN THE DAY. THE ECMWF BRINGS A WEAK FRONT
THROUGH LATER MONDAY. HIGH PRESSURE THEN CONSOLIDATES AGAIN ALONG THE
EAST COAST TUESDAY AS A VERY STRONG RIDGE OF HIGH PRESSURE BUILDS
INTO THE EAST. THIS WILL BRING A PARTLY SUNNY AND VERY MILD DAY ON
TUESDAY. THE STRONGEST INFLUENCE OF THE RIDGING WILL LIKELY COME
WEDNESDAY WHEN WARM WEST TO SOUTHWEST WINDS BOOST TEMPS INTO THE 60S
AND PERHAPS EVEN 70S ACROSS THE REGION. THE VERY WARM TEMPS DURING
THE MID WEEK NEXT WEEK WILL LIKELY RESULT IN LOTS OF SNOW MELT. THE
RELEASE OF SNOW MELT MAY RESULT IN RISES ON RIVERS AND POTENTIAL ICE
JAMS DURING THE MID AND LATE WEEK NEXT WEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR TONIGHT FOR ALL TERMINALS...BCMG MVFR THURSDAY
MORNING AND VFR BY LATE AFTERNOON.
SHORT TERM: VFR THURSDAY NIGHT INTO EARLY FRIDAY THEN CONDITIONS
WILL LOWER TO MVFR/IFR IN RAIN FRIDAY AFTERNOON THROUGH FRIDAY
EVENING AND THEN IMPROVE TO VFR LATER FRIDAY NIGHT. EXPECT VFR
CONDITIONS SATURDAY THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM: SCA WILL CONTINUE INTO EARLY THURSDAY MORNING...BARELY
MEETING CRITERIA WITH WIND GUSTS AROUND 25 KTS AND 5 FT SEAS.
SHORT TERM: WINDS AND SEAS BELOW SCA CRITERIA THURSDAY NIGHT
THROUGH SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
ANZ050>052.
&&
$$
NEAR TERM...KHW/VJN
SHORT TERM...FOSTER
LONG TERM...BLOOMER
AVIATION...KHW
MARINE...KHW/FOSTER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1241 AM EDT THU MAR 15 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK SLOWLY EAST OF THE REGION OVERNIGHT. HIGH
PRESSURE WILL BUILD BRIEFLY INTO THE AREA LATER THURSDAY. A WEAK
TROUGH OF LOW PRESSURE WILL APPROACH FROM THE WEST ON FRIDAY AND
CROSS THE STATE LATE FRIDAY AND FRIDAY NIGHT. HIGH PRESSURE WILL
REBUILD INTO THE AREA OVER THE WEEKEND WITH AN UNSEASONABLY WARM
WEATHER PATTERN SHAPING UP FOR NEXT WEEK.&&
.NEAR TERM /THROUGH TODAY/...
UPDATE: GOOD DEFORMATION AXIS CONTS ATTM ACROSS NE AND E CENTRAL
AREAS. PER LATEST TRENDS...RAISED SNOW AMOUNTS ACROSS ERN SECTIONS
A BIT MORE AND ADJUSTED POPS. ALLOWED WRN ADVS TO EXPIRE AND XTND
ERN ADVS TIL 2 AM. CURRENT WRNG FOR ZN2 CONTS TIL 2 AM AND COULD
SEE SOME LOCALIZED ACCUMS UP TO A FOOT ACROSS ERN SECTIONS WHEN
ALL IS SAID AND DONE.
UPDATE 2: BASED ON LATEST SPOTTER SNOW REPORTS RECEIVED FROM THE
CARIBOU...FORT FAIRFIELD...PRESQUE ISLE AREA WHICH WERE UP TO 7 TO
8 INCHES AND LATEST MESO-MODEL GUIDANCE...INCLUDING THE 18Z NAM
AND 21Z HRRR MODELS THAT NOW KEEP THE BAND ORIGINATING FROM SRN
NB AIMED TOWARD NE ME OVR THE SAME RELATIVE AREA FOR THE NEXT FEW
HRS; IT APPEARS IMMINENT THAT SOME LOCATIONS COULD EXPERIENCE A
STORM TOTAL UP TO OR JUST OVER 10 INCHES...WITH THE HIGHEST
AMOUNTS CLUSTERED NEAR THE NB BORDER BOUNDED BY LIMESTONE...
CARIBOU...PRESQUE ISLE AND MARS HILL. INDEED...THE AMOUNT OF AREA
TO BE AFFECTED BY HEAVY SN ACCUMULATIONS WITHIN NE AROOSTOOK
COUNTY IS LESS THAN 50 PERCENT OF ZONE 2...BUT IS AFFECTING THE
MOST URBAN AREAS THE MOST. RADAR INDICATES ONE LAST PULSE (PERHAPS
THE LAST) OF MDT TO HVY SN WITH THIS BAND TAKING AIM TOWARD THE
WRNG AREA...SO SNFL RATES UP TO AN INCH AN HR AT TIMES OVR SOME
AREAS CAN BE XPCTD UNTIL MDNGT OR SO BEFORE SN RATES WIND DOWN.
WITH DEEP ELEVATED WARM ADVCN WEAKENING IN THE TROWAL ZONE XTNDG
TOWARD E ME DURG THE LATE NGT/ERLY MORN HRS...ANY REMAINING
ORGANIZED SNFL SHOULD QUICKLY WIND DOWN OVR THE FA AS THE UPPER
LOW BEGINS TO MOVE INTO SRN NB.
UPDATE 1: SENT A QUICK UPDATE TO INCREASE TOTAL SNFL AMOUNTS
TO 4 TO 8 IN ACROSS PORTIONS OF NERN AND FAR NRN AROOSTOOK COUNTY
BASED ON A FEW OBS OF 5 IN ATTM. SOME UNCERTAINTY EXISTS REGARDING
HOW BANDING WILL EVOLVE OVR THE NEXT FEW HRS...WITH NEAR TERM
MODELS SUCH AS THE HRRR SHOWING THE ENHANCED BANDING CURRENTLY
JUST W OF THE ME-NB BORDER POSSIBLY GRAZING FAR NE AROOSTOOK
COUNTY. WILL MONITOR CLOSELY DURG THIS TM.
ORGNL DISC: UPPER LOW TRACKING TOWARDS THE WESTERN BORDER OF
MAINE AS EXPECTED. SOME INSTABILITY ABOVE H850 AND A SHARP UPPER
TROUGH ROTATING AROUND THE CLOSED UPPER LOW IS PRODUCING LOCALLY
HEAVIER SNOW SHOWERS IN FAR NORTHEASTERN ZONES. WILL GO FOR UP TO
5 INCHES IN NE CORNER OF STATE...BUT EXPECT WIDE VARIATIONS FOR
NORTHERN ZONES DUE TO HIT OR MISS NATURE OF THE HEAVIER SNOW
SHOWERS. MOISTURE CONTINUES TO WRAP BACK NORTHWESTWARDS FROM THE
MARITIMES AND WILL HELP PROLONG SNOW IN NORTHERN ZONES WELL INTO
THE NIGHT. DOWN EAST AREAS WILL GET A BRIEF SHOT OF SNOW THIS
EVENING THAT MAY LAY DOWN AN INCH OR SO. THIS WILL BE IN
CONJUNCTION WITH THE UPPER LOW PASSAGE. THE THREAT FOR FZDZ IS
STILL THERE WITH THE RISK FROM NEAR MILO TOWARDS NORTHERN
WASHINGTON COUNTY THIS AFTERNOON AND QUICKLY SHIFTING TO SOUTHERN
WASHINGTON COUNTY THIS EVENING BEFORE THE WARM AIR ALOFT IS GONE.
TEMPERATURES TONIGHT WILL DIP SLIGHTLY IN THE LOWER 20S NORTH AND
UPPER 20S DOWN EAST.
WITH SNOW ENDING IN THE FAR EASTERN ZONES EARLY THURSDAY
MORNING...HIGH PRESSURE WILL BUILD BUT CLOUD COVER ASSOCIATED WITH
A SUBSIDENCE INVERSION WILL BE SLOW TO ERODE FROM THE WEST. EXPECT
SOME CLEARING TOWARDS BANGOR BY AFTERNOON...BUT NOT UNTIL LATE DAY
TOWARDS THE EASTERN BORDER OF THE STATE. HIGHS WILL REACH THE LOW
TO MID 30S TOWARDS THE SJV AND INCREASE TOWARDS DOWN EAST WHERE
LOW 40S ARE LIKELY.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL CREST THE REGION THURSDAY NIGHT AND THEN MOVE
EAST OF THE AREA EARLY FRIDAY. MODELS IN GOOD AGREEMENT WITH UPPER
TROUGH APPROACHING FROM THE WEST FRIDAY AND CROSSING THE STATE BY
FRIDAY EVENING. EXPECT ASSOCIATED LOW PRESSURE AND COLD FRONT TO
SPREAD MAINLY RAIN FROM WEST TO EAST ACROSS THE STATE FRIDAY
AFTERNOON. RAIN MAY MIX WITH SNOW ACROSS EXTREME NORTHERN
SECTIONS. THEN AS UPPER TROUGH MOVES EAST OF THE STATE, CONDITIONS
WILL IMPROVE FROM WEST TO EAST FRIDAY NIGHT. QPF AMOUNTS AT THIS
TIME APPEARS TO BE ON THE LIGHT SIDE WITH AMOUNTS GENERALLY BELOW A
QUARTER OF AN INCH. HIGH PRESSURE THEN BUILD ACROSS NEW ENGLAND ON
SATURDAY WITH CLEAR SKIES AND MODERATING TEMPERATURES INTO THE 40S
AND 50S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
RIDGING BUILDING ALONG THE EAST COAST WILL SET THE STAGE FOR SOME
VERY MILD WEATHER GOING INTO EARLY NEXT WEEK. HIGH PRESSURE ALONG
THE EAST COAST WILL BRING A MOSTLY CLEAR NIGHT SATURDAY NIGHT
FOLLOWED BY A PARTLY SUNNY AND MILD DAY ON SUNDAY. THE LATEST GFS
SHOWS A WEAK COLD FRONT MOVING IN LATE SUNDAY WHICH MAY BRING
INCREASING CLOUDS LATE IN THE DAY. THE ECMWF BRINGS A WEAK FRONT
THROUGH LATER MONDAY. HIGH PRESSURE THEN CONSOLIDATES AGAIN ALONG THE
EAST COAST TUESDAY AS A VERY STRONG RIDGE OF HIGH PRESSURE BUILDS
INTO THE EAST. THIS WILL BRING A PARTLY SUNNY AND VERY MILD DAY ON
TUESDAY. THE STRONGEST INFLUENCE OF THE RIDGING WILL LIKELY COME
WEDNESDAY WHEN WARM WEST TO SOUTHWEST WINDS BOOST TEMPS INTO THE 60S
AND PERHAPS EVEN 70S ACROSS THE REGION. THE VERY WARM TEMPS DURING
THE MID WEEK NEXT WEEK WILL LIKELY RESULT IN LOTS OF SNOW MELT. THE
RELEASE OF SNOW MELT MAY RESULT IN RISES ON RIVERS AND POTENTIAL ICE
JAMS DURING THE MID AND LATE WEEK NEXT WEEK.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
NEAR TERM: IFR TONIGHT FOR ALL TERMINALS...BCMG MVFR THURSDAY
MORNING AND VFR BY LATE AFTERNOON.
SHORT TERM: VFR THURSDAY NIGHT INTO EARLY FRIDAY THEN CONDITIONS
WILL LOWER TO MVFR/IFR IN RAIN FRIDAY AFTERNOON THROUGH FRIDAY
EVENING AND THEN IMPROVE TO VFR LATER FRIDAY NIGHT. EXPECT VFR
CONDITIONS SATURDAY THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM: SCA WILL CONTINUE INTO EARLY THURSDAY MORNING...BARELY
MEETING CRITERIA WITH WIND GUSTS AROUND 25 KTS AND 5 FT SEAS.
SHORT TERM: WINDS AND SEAS BELOW SCA CRITERIA THURSDAY NIGHT
THROUGH SATURDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 2 AM EDT EARLY THIS MORNING FOR
MEZ002.
WINTER WEATHER ADVISORY UNTIL 2 AM EDT EARLY THIS MORNING FOR
MEZ005-006-017-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
ANZ050>052.
&&
$$
NEAR TERM...KHW/VJN
SHORT TERM...FOSTER
LONG TERM...BLOOMER
AVIATION...KHW
MARINE...KHW/VJN/FOSTER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
409 AM EDT THU MAR 15 2012
.SYNOPSIS...
ISSUED AT 405 AM EDT THU MAR 15 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WSW FLOW ALF FM
THE PAC NW TO ONTARIO BTWN UPR RDG MOVING SLOWLY E THRU THE GREAT
LKS AND A LARGER SCALE TROF OFF THE W COAST. SFC COOL FNT ATTENDANT
TO STRONG SHRTWV LIFTING NEWD THRU HUDSON BAY IS MOVING E THRU UPR
MI EARLY THIS MRNG AND WL BRING AT LEAST A TEMPORARY END TO RECORD
WARMTH THAT ENVELOPED THE AREA ON WED...WHEN THE MERCURY PEAKED IN
THE 70S AT MANY SPOTS AND AS HI AS 77 AT KENTON. THERE WAS A SURGE
OF LLVL MSTR MOVING NEWD AHEAD OF THIS COOL FNT...AND SOME FOG AND
SC HAVE DVLPD OVER THE SE HALF OF THE CWA AHEAD OF THE COOL FNT.
ALTHOUGH THE 00Z GRB RAOB SHOWS STEEP H8-5 LAPSE RATES NOT FAR FM
DRY ADIABATIC...THE DRYNESS OF THE MID LVLS AND A SHARP INVRN NEAR
H8 THAT HAS CAPPED THE LLVL MOISTENING/DESTABILIZATION AND HELD IN
THE ABSENCE OF ANY DYNAMIC SUPPORT SO FAR S OF THE HUDSON BAY SHRTWV
HAVE CONSPIRED TO PREVENT THE DEVELOPMENT OF ANY SHRA/TS. BEHIND THE
FNT...HI PRES IN THE NRN PLAINS IS TENDING TO BUILD TO THE ENE. THE
00Z INL RAOB DEPICTS A VERY DRY LOWER TROP WITH H925/H85 DEWPT
DEPRESSIONS OF 18C/22C. SFC DEWPTS HAVE FALLEN INTO THE TEENS OVER
THE N HALF OF MN. ALTHOUGH THE COOL FNT PASSED IWD/CMX IN THE EARLY
EVNG...SFC DEWPTS THERE ARE STILL IN THE MID 30S. OVER THE S HALF OF
MN...SFC DEWPTS REMAIN AS HI AS 45 EVEN BEHIND THE FROPA. BUT EXCEPT
FOR SOME HI CLDS...SKIES ARE MOCLR AS THE 00Z MPX RAOB IS QUITE DRY
IN A RELATIVE SENSE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
TDAY...MAIN FCST CONCERNS IN THE SHORT TERM RELATE TO THE EXTENT OF
THE LLVL DRYING THAT WL OCCUR OVER THE CWA IN THE WAKE OF THE COOL
FNT THAT IS FCST TO CLEAR THE SE ZNS BY FCST ISSUANCE. MODELS IN
RECENT DAYS HAVE SHOWN SOME DISAGREEMENT ON THIS DRYING BECAUSE THE
FLOW ALF IS EXPECTED TO REMAIN WSW AND TAKE THE SFC HI PRES/CORE OF
THE REALLY DRY AIR NOW IN NW MN INTO ONTARIO. BUT EVEN IF THE LLVL
AIRMASS MOVING INTO UPR MI COMES FM THE DIRECTION OF MPX...THE
RELATIVE DRYNESS OF THE AIRMASS THERE IS A GOOD INDICATION LO CLDS
ARE LESS LIKELY TO DEVELOP THAN PREVIOUSLY FCST. WITH THE EXCEPTION
OF THE GFS...THE 00Z RUNS HAVE COME INTO GOOD AGREEMENT SHOWING MORE
DRYING IN THE H95-9 LYR THRU THE DAY. GIVEN THE DRYNESS/LACK OF CLDS
UPSTREAM AND DIFFLUENT NATURE OF THE FLOW...WL FOLLOW THE 00Z LOCAL
WRF-ARW THAT INDICATES MORE AGGRESSIVE LLVL DRYING AND CUT BACK ON
THE EXTENT OF THE LO CLDS. THIS MODEL DOES INDICATE SOME LO CLDS MAY
LINGER OVER THE E THIS MRNG IN THE WAKE OF THE FROPA...BUT OTRW
INDICATES THE DAY SHOULD BE MOSUNNY EXCEPT FOR SOME HI CLDS. MIXING
TO H85 ON WRF-ARW SDNGS INDICATES HI TEMPS WL TOP OUT ARND 60 OVER
LOCATIONS NEAR THE WI BORDER WELL INLAND FM LK SUP COOLING IN THE
LLVL N-NE FLOW. HI TEMPS ARE LIKELY TO HOLD IN THE 40S NEAR LK SUP E
OF THE KEWEENAW WITH ONSHORE 15KT NE H925 WINDS.
TNGT...ALTHOUGH A WEAK SHRTWV IS PROGGED TO RIPPLE THRU THE UPR
FLOW...THE MID LVLS ARE TOO DRY FOR ANY PCPN. IN FACT...FCST
SOUNDINGS INDICATE ONLY SOME HI CLDS. EXPECT A HEALTHY DIURNAL TEMP
FALL WITH LIGHT WINDS. THE LOWEST MIN TEMPS ARE LIKELY OVER THE
INTERIOR E AND CNTRL WHERE THE WINDS WL BE LIGHTEST THRU THE NGT.
INCRSG S WIND LATER AS HI PRES RDG BEGINS TO RETREAT TO THE E WL
LIKELY KEEP TEMPS A BIT ELEVATED OVER THE FAR W FM IWD TO ONTONAGON.
THE LOCAL WRF-ARW FCST SDNGS INDICATE THE BEST CHC FOR FOG WL BE
OVER THE E...WHERE A BIT MORE AMPLE LLVL MSTR WL COINCIDE WITH THE
LGT WINDS.
FRI...SFC HI CENTER IS FCST TO DRIFT INTO QUEBEC...WITH INCRSG SLY
FLOW UNDER SHARPENING PRES GRADIENT BTWN THE DEPARTING HI AND
FALLING PRES IN THE PLAINS. THE RETURN OF HIER H95-9 SPECIFIC
HUMIDITY WL RESULT IN SOME AFTN CU/SC. WITH H85 TEMPS FCST TO
REBOUND TO ARND 12C...TEMPS WL REBOUND INTO THE 60S AWAY FM LK
MODERATION...WARMEST OVER THE W WHERE THE SSE SFC FLOW DOWNSLOPES.
FRI NGT...SSW H925 WINDS INCRSG UP TO 25-35 KTS ON THE WRN FLANK OF
RETREATING HI PRES ARE FCST TO BRING MORE LLVL MSTR SURGING INTO THE
UPR LKS. ALTHOUGH MODELS GENERATE SPOTTY QPF...GFS FCST SDNGS SHOW
CAPPING INVRN LINGERING BTWN H8-75 IN THE ABSENCE OF ANY DYNAMIC
SUPPORT WITHIN UPR RDG AXIS. SO OPTED TO KEEP GOING DRY FCST. SOME
FOG IS LIKELY OVER THE E IN AREAS DOWNWIND OF LK MI EVEN THOUGH THE
STRONG WINDS/LLVL MOISTENING WL RETARD THE DIURNAL FALL OF TEMP.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
UPPER RIDGE WILL BE IN CONTROL OF THE REGION AT THE START OF THE
PERIOD AND CONTINUE THROUGH THE FIRST HALF OF NEXT WEEK.
AT THE SFC...AREA WILL BE BETWEEN A COLD FRONT OVER THE ERN DAKOTAS
AND SFC HIGH MOVING E INTO THE NEW ENGLAND STATES. THIS WILL ALLOW
SRLY FLOW TO BE IN PLACE AND MODELS SHOWING GOOD H950-850 MOISTURE
SURGING NNE OVER THE AREA FRI NIGHT AND INTO SAT. IF THIS MOISTURE
IS PRESENT AND LOW CLOUDS FORM...COULD BE DIFFICULT TO BREAK OUT ON
SATURDAY IF THIS OCCURS. BUT LATEST TRENDS IN NAM/GFS ARE SHOWING
MORE MIXING PRESENT AND FEEL A PARTLY CLOUDY FORECAST IS WARRENTED
FOR ALL BUT NEAR LK MI...WHERE FOG ON SAT MORNING WILL KEEP THINGS
MOSTLY CLOUDY. THIS MAKES TEMPS TRICKY...AS IT WILL DEPEND ON THE
CLOUDS BREAKING OUT. THINK THE WEST HALF HAS A BETTER CHANCE OF THIS
OCCURRING AND TRENDED TOWARDS THE WARM SIDE. MIXING TO H900 WOULD
GIVE HIGHS NEAR 70S AND HAVE FOLLOWED THAT. DEPENDING ON THE WIND
DIRECTION...WHICH IS TRENDING A LITTLE SSW...SO TRENDED TEMPS UP
THERE SLIGHTLY DUE TO DOWNSLOPE WINDS.
ONE FINAL THING OF NOTE IS THE NAM IS SHOWING DECENT
INSTABILITY...2K J/KG OF CAPE...IN THE AFTN WITH THE STRONG DIURNAL
HEATING OVER THE W HALF. OPTED TO REMAIN DRY EVEN WITH THIS
INSTABILITY POTENTIAL...BUT WILL NEED TO MONITOR.
WEAK UPPER LEVEL DISTURBANCE SATURDAY NIGHT AND SUNDAY LOOKS TO STAY
S OF THE CWA. COULD SEE SOME SHOWERS DEVELOPING WITH THIS WEEK
DISTURBANCE OVER CNTRL LK MI AND LOWER MI. MAIN FEATURE OF NOTE TO
AFFECT THE CWA IS A DECAYING COLD FRONT DROPPING OVER LK SUPERIOR
SAT NIGHT. WILL PUSH N ON SUNDAY AS A WARM FRONT AS LOW PRESSURE
ORGANIZES OVER THE NRN PLAINS. QUESTION IS HOW FAR S IT WILL SINK
BEFORE PUSHING BACK N. GFS/ECMWF/GEM STALL IT OVER LK SUPERIOR AND
MAYBE REACHING THE KEWEENAW PENINSULA. NAM TRIES TO PUSH IT A TOUCH
FARTHER S AND DEVELOP PCPN OVER MUCH OF UPPER MI. FINDING IT HARD TO
BUCK THE MODEL CONSENSUS...ESPECIALLY THAT FAR OUT ON THE NAM...SO
WILL CONFINE THE CHANCE POPS OVER LK SUPERIOR AND LK MI AND KEEP
SLIGHTS IN BETWEEN.
EXTENDED /SUNDAY NIGHT THROUGH WEDNESDAY/...
ANOMALOUS H500 HEIGHTS...AROUND 2-3 STD DEV ABOVE NORMAL FOR
MID-LATE MARCH WILL REMAIN OVER THE AREA FOR THE EXTENDED PERIOD.
TROUGH OVER AMPLIFYING AND MOVING OVER THE SW CONUS WILL AMPLIFY THE
RIDGE UPSTREAM AND LEAD TO CONTINUED WARMING UNDER SRLY FLOW KEEPING
WARM AIR IN PLACE.
WITH THE SRLY FLOW...MODELS CONTINUE TO SURGE WARM/MOIST AIR OVER
THE AREA. THIS MAKES FOR A TROUBLING FORECAST...AS IT IS LARGELY
DEPENDENT ON IF LOW CLOUDS DEVELOP BELOW THE PERSISTANT H850
INVERSION. IF THE LAST 12HRS ARE ANY INDICATION...PRODUCES SOME
DOUBT TO NORTHWARD EXTENT. BUT THE PERSISTANT SRLY FLOW WILL LIKELY
PUSH THE MOISTURE INTO THE AREA AND SHOULD LEAD TO MORE
CLOUDY/FOGGY NIGHTS WHICH WILL BREAK UP DUE TO DIURNAL HEATING.
ADDED FOG OVER LK SUPERIOR/MICHIGAN THROUGH THE EXTENDED AND BLED
IT INLAND NEAR LK MI DURING THE OVERNIGHT HOURS WITH THE SSE WINDS.
TEMPS WILL GREATLY DEPEND ON LOW CLOUDS/FOG AND DAYTIME MIXING...BUT
WILL CONTINUE TO BE WELL ABOVE NORMAL WITH MANY DAYS IN THE 60S
OVER THE WEST. COOLER VALUES OVER THE E AND ALSO PORTIONS OF THE
NCNTRL...DUE TO SSE WINDS THROUGH MUCH OF THE PERIOD.
AS FOR PCPN...MODELS CONTINUING TO SHOW LIGHT QPF ALONG AND OVER
THE GREAT LKS. WHAT IS LIKELY HAPPENING IS THAT THE ABUNDANT
MOISTURE IS TOO MUCH IN THE LOW LEVELS AND THE MODELS ARE TRYING TO
RELIEVE THEMSELVES OF THIS EXCESS MOISTURE. WILL LIKELY BE FOG IN
THESE AREAS DUE TO THE MOIST AIR OVER THE COOL GREAT LKS...BUT
DON/T SEE MUCH CHANCES FOR SHOWERS WITH THE STRONG H850 CAP. IF
ANYTHING...A FOG/DZ COMBINATION WOULD OCCUR. THUS...HAVE REMOVED
MUCH OF THE SLIGHT CHANCES FROM SUN NIGHT ON.
MODELS SHOWING THE UPPER RIDGE STARTING TO SHIFT E AS THE UPPER
TROUGH STARTS TO BECOME CUT OFF ON WED. HOW THIS LOW EVOLVES WILL
AFFECT THE FORECAST FOR THE END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1259 AM EDT THU MAR 15 2012
VFR CONDITIONS WILL CONTINUE TO DOMINATE THROUGH THE PERIOD AT ALL 3
SITES UNDER A VERY DRY AIRMASS. LAKE BREEZES WILL KICK IN AT ALL 3
SITES ON THU AND MAKE THE WIND MORE NERLY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 AM EDT THU MAR 15 2012
EXPECT WINDS TO BE MOSTLY UNDER 20 KTS THROUGH THIS WEEKEND AS A
RELATIVELY WEAK PRES GRADIENT DOMINATES. ALTHOUGH A SHARPER PRES
GRADIENT/STRONGER S FLOW WILL DEVELOP OVER THE WEEKEND...THE
UNSEASONABLY WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN
PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE LAKE...HELPING TO
KEEP SURFACE WINDS ON THE LIGHTER SIDE. AT SOME POINT...FOG MAY
BECOME AN ISSUE...ESPECIALLY IF SOME RAINFALL OCCURS OVER THE LAKE.
RIGHT NOW...IT APPEARS DRY WEATHER SHOULD GENERALLY DOMINATE...
KEEPING FOG POTENTIAL LIMITED.
&&
.HYDROLOGY...
ISSUED AT 405 AM EDT THU MAR 15 2012
WELL ABOVE NORMAL TEMPERATURES OVER THE LAST SEVERAL DAYS...
ESPECIALLY ON WED...ALONG WITH RAIN OF 0.10 TO MORE THAN 0.5 INCH ON
MON HAS LED TO INCREASED SNOWMELT/RUNOFF. THIS RUNOFF HAS PRODUCED
SOME RISE IN LEVELS OF RIVERS IN UPR MI OVER THE LAST COUPLE OF DAYS.
ABOVE NORMAL TEMPERATURES INTO NEXT WEEK WILL CONTINUE TO MELT THE
SNOW PACK AND LEAD TO FURTHER INCREASES IN RIVER AND STREAM LEVELS.
ALTHOUGH A COOLER/DRIER AIRMASS WILL ARRIVE TODAY AND SLOW THE
MELTING...EXPECT SOME OF THE RIVERS ACROSS THE AREA TO EXCEED THEIR
BANKS BY THE END OF THIS WEEK. FORTUNATELY...THE LACK OF ANY
SIGNIFICANT RAIN IN THE FORECAST FOR THE NEXT WEEK WILL LOWER THE
CHANCE OF SIGNIFICANT FLOODING. BUT PERSONS LIVING NEAR RIVERS AND
STREAMS SHOULD MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF
WALKING ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
DID HAVE AN APPARENT ICE JAM ON THE ONTONAGON RIVER NEAR ROCKLAND
MON EVENING. THIS CAUSED THE RIVER LEVELS TO RISE 4FT BEFORE IT
BROKE FREE. WILL NEED TO MONITOR CONDITIONS ALONG THE ONTONAGON
RIVER OVER THE NEXT DAY OR TWO...AS THE NUMEROUS BENDS COULD CAUSE
THE ICE TO FORM ANOTHER JAM. IN ADDITION...ICE WAS REPORTED ON THE
FORD RIVER AT HYDE AND THE MOUTH AT LK MI. DEPENDING ON THE BREAKUP
OF THE ICE...THERE IS A POTENTIAL FOR MORE ICE JAMS INTO THIS
WEEKEND...WHEN THE RIVER ICE MAY CLEAR COMPLETELY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...07
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1230 AM CDT THU MAR 15 2012
...UPDATE TO AVIATION...
.UPDATE...
THE 00Z NAM AND RUC CONTINUE TO INDICATE A SIGNAL FOR ISOLATED TO
WIDELY SCATTERED CONVECTIVE DEVELOPMENT LATE TONIGHT. BOTH MODELS
NOSE A WEAK CORRIDOR OF ISENTROPIC UPGLIDE IN THE 300-305 K LAYER
INTO THE REGION BEGINNING AROUND OR JUST AFTER 09Z. LIFTING
PARCELS FROM THIS SAME LAYER YIELDS LITTLE IF ANY CONVECTIVE
INHIBITION...ESPECIALLY ALONG AND SOUTH OF A PITTSBURG KANSAS TO
LAKE OF THE OZARKS LINE. THE GOING POPS HAVE THIS COVERED WELL.
DESPITE 0-6 KM EFFECTIVE BULK SHEARS AT OR BELOW 20 KNOTS...
MUCAPES IN THE 1800 TO 2400 J/KG RANGE WILL STILL SUPPORT SOME
HAIL POTENTIAL. DID ADD A LIMITED HAIL THREAT TO THE HAZARDOUS
WEATHER OUTLOOK.
SCHAUMANN
&&
.DISCUSSION...
/ISSUED 1255 PM CDT WED MAR 14 2012/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
FOR THE NEAR TERM THIS AFTERNOON...SCATTERED CU CONTINUE TO BUBBLE
UP ACROSS THE REGION...AS COMBINATION OF INCREASING TEMPERATURES AND
NEAR 60 DEWPOINTS HAS ERODED MUCH OF THE INHIBITION EVIDENT ON THIS
MORNING`S 12Z RAOB. DESPITE THIS...DRY AIR ALOFT (ALSO PER 12Z
SOUNDING) AND HIGH LFCS...ALONG WITH NEARLY NON-EXISTENT LOW LEVEL
FORCING SHOULD RESULT IN VERY LOW CONVECTIVE COVERAGE...THIS
AFTERNOON/EARLY EVENING. CURRENT THINKING REMAINS THAT HIGHER
TERRAIN OF THE BOSTON MOUNTAINS AND FAR SOUTH-CENTRAL MO WILL SERVE
AS THE INITIAL FOCUS FOR CONVECTION THIS AFTERNOON. STEEP LAPSE
RATES ALOFT AND THE AFOREMENTIONED DRY AIR COULD LEAD TO A FEW
MARGINALLY SEVERE HAIL AND WIND REPORTS WITH THE STRONGEST
STORMS...BUT AGAIN...COVERAGE SHOULD BE QUITE SPARSE.
EXPECT TO SEE MUCH OF THE CONVECTION DIMINISH WITH SUNSET TONIGHT.
A MORE ORGANIZED WAVE WILL APPROACH THE AREA TOWARD THE MORNING
HOURS TOMORROW...WITH AN ASSOCIATED UPTICK IN SHOWERS/THUNDERSTORMS
EXPECTED. THINK WE`LL SEE A FEW WAVES OF CONVECTION THROUGHOUT THE
DAY ON THURSDAY AS A 60 KT BRANCH OF THE SUBTROPICAL JET NOSES INTO
THE AREA. 0-6 KM SHEAR VALUES THURSDAY SHOULD BE IN THE 20-25 KT
RANGE...SUFFICIENT FOR AT LEAST OCCASIONAL CONVECTIVE ORGANIZATION.
INSTABILITY FORECASTS ARE A PROBLEM FOR TOMORROW...WITH VERY LOW
CONFIDENCE IN THE AMOUNT OF BREAKS IN THE CLOUDS.
OBVIOUSLY...AVAILABLE INSTABILITY WILL RISE CONSIDERABLY IF WE DO
SEE OCCASIONAL SUNSHINE DURING THE DAY. OVERALL...THINK THE SEVERE
THREAT IS LIMITED...WITH JUST AN ISOLATED WIND GUST AND/OR LARGE
HAIL REPORT EXPECTED. TEMPERATURES WILL ALSO BE TRICKY TOMORROW.
FOR NOW HAVE GONE A LITTLE ON THE COOL SIDE OF GUIDANCE (MID TO
UPPER 70S)...BUT IF A LITTLE MORE SUNSHINE THAN EXPECTED PEAKS
THROUGH THE CLOUDS...THEN READING APPROACHING OR PERHAPS EVEN
EXCEEDING 80 IN A FEW AREAS WON`T BE OUT OF THE QUESTION.
SIMILAR CONDITIONS TO TODAY ARE EXPECTED FOR FRIDAY...AS ADDITIONAL
WEAK RIPPLES PASS THROUGH IN SOUTHWEST FLOW. TEMPERATURES FOR
FRIDAY SHOULD AGAIN APPROACH THE 80 DEGREE MARK IN MANY
LOCATIONS.
BOXELL
LONG TERM (SATURDAY THROUGH WEDNESDAY)...
LATEST ROUND OF MEDIUM RANGE MODEL OUTPUT OFFERS A FEW NEW TWISTS
ON THE FORECAST. OVERALL...STILL EXPECTING AN INCREASINGLY
AMPLIFIED PATTERN WITH A DEEP TROUGH OVER THE WESTERN CONUS AND
STRONG RIDGING OVER THE EASTERN CONUS. THE CHALLENGES FOR THIS
FORECAST IS THE EXPECTED BEHAVIOR OF THE WESTERN TROUGH. THERE IS
DISAGREEMENT WITH WHETHER OR NOT THIS TROUGH WILL BECOME CUTOFF
AND LINGER TO OUR WEST (PER THE GEFS)...REMAIN AN OPEN TROUGH AND
SLOWLY TRANSLATE EASTWARD (GEM/UKMET/00Z ECMWF). GIVEN THE FIVE
WAVE PROGS IT/S REALLY DIFFICULT TO FAVOR ONE SOLUTION OVER THE
OTHER AT THIS POINT. HAVE GONE WITH A CONSENSUS OF THE MODELS FOR
THE TIME BEING UNTIL A FAVORED SOLUTION IS IDENTIFIED.
FROM A SENSIBLE WEATHER PERSPECTIVE...CONTINUED WARM WITH ISOLATED
TO WIDELY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED
OVER THE WEEKEND. AT THIS POINT...BETTER COVERAGE (RELATIVELY
SPEAKING) LOOKS TO BE ON SATURDAY AFTERNOON. SHOULD SEE A QUIETER
PERIOD SUNDAY NIGHT AND MONDAY...WITH GRADUALLY INCREASING POPS
FROM WEST TO EAST TUE/WED. WELL ABOVE AVERAGE TEMPERATURES WILL
CONTINUE INTO THE FIRST PART OF NEXT WEEK.
GAGAN
&&
.AVIATION...
ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP LATE TONIGHT AND CONTINUE INTO THURSDAY
MORNING. DID INCLUDE A TEMPO GROUP FOR THUNDERSTORMS AND MVFR
VISIBILITIES TO COVER THIS. MAINLY DRY CONDITIONS AND VFR FLIGHT
CATEGORIES ARE EXPECTED FROM THURSDAY AFTERNOON INTO THURSDAY
EVENING. WINDS WILL REMAIN OUT OF THE SOUTH...BECOMING GUSTY
THURSDAY AFTERNOON.
SCHAUMANN
&&
.CLIMATE...
SPRINGFIELD (KSGF)
DAY DATE TEMP YEAR
THR 15TH 79 1983
FRI 16TH 84 1945
JOPLIN (KJLN)
DAY DATE TEMP YEAR
THR 15TH 80 1983
FRI 16TH 78 1995
ROLLA-VICHY (KVIH)
DAY DATE TEMP YEAR
THR 15TH 75 1995
FRI 16TH 78 1982
WEST PLAINS (KUNO)
DAY DATE TEMP YEAR
THR 15TH 78 1977
FRI 16TH 82 1982
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
328 AM CDT THU MAR 15 2012
.SHORT TERM...TODAY THROUGH FRIDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE COLD
FRONT STRETCHING FROM LA CROSSE TO DOOR COUNTY EARLY THIS MORNING
AND SLOWLY SLIDING TO THE SOUTHEAST. WIDELY SCATTERED CONVECTION
FINALLY DEVELOPED ALONG THE FRONT ACROSS SOUTHEAST WISCONSIN AND
NORTHERN ILLINOIS...AND A FEW CELLS MAY GRAZE SHEBOYGAN COUNTY.
FARTHER NORTH...4-6KFT CLOUDS HAVE BEEN EXPANDING OVER NORTHEAST
WISCONSIN AND LAKE MICHIGAN WHILE PATCHY DENSE FOG HAS DEVELOPED
OVER CENTRAL WISCONSIN. AS NORTH TO NORTHEAST WINDS DEVELOP BEHIND
THE FRONT EARLY THIS MORNING...ANTICIPATING THE FOG TO DISSIPATE WITH
MOST OF IT GONE BY THE MORNING COMMUTE. WITH THE FRONT SETTLING TO
THE SOUTH TODAY...MAIN FORECAST CONCERNS REVOLVE AROUND SKY
CONDITIONS...FOG POTENTIAL...AND TEMPS.
TODAY...SURFACE COLD FRONT WILL SETTLE ACROSS THE SOUTHERN GREAT
LAKES TODAY WHILE HIGH PRESSURE MOVES ACROSS LAKE SUPERIOR. 850MB
FRONT WILL LAG TO THE NORTH OVER NORTHERN WISCONSIN...WHICH WILL
KEEP AMPLE MOISTURE IN THE 925-850MB LAYER. BEHIND THE
FRONT...SURFACE WINDS WILL TURN NE TO EASTERLY WHICH WILL ADVECT A
SHALLOW MARINE AIRMASS OVER MUCH OF NE WISCONSIN AND PARTIALLY INTO
CENTRAL WISCONSIN. PROGGED SOUNDINGS THIS MORNING ARE FOLDED
OVER...WITH THE RESIDUAL WARM AIRMASS LAYING OVER TOP THE RELATIVELY
COLDER MARINE AIRMASS...SUGGESTING A LAYER OF STRATUS OR FOG COULD
POSSIBLY FORM. THINK THIS PROCESS IS UNDER WAY OVER NORTHERN LAKE
MICHIGAN AS INDICATED BY THE GROWING DARK BLOB ON THE SATELLITE.
WILL INCREASE SKY COVER OVER MUCH OF NE AND E-C WISCONSIN...AND SOME
OVER CENTRAL WISCONSIN TOO FOR THIS MORNING. THINK THIS WILL EVOLVE
INTO A CU DECK WITH HEATING FOR THE AFTERNOON WITH PARTIAL CLEARING
ANTICIPATED. OVER N-C WISCONSIN...A VERY DRY AIRMASS WILL PUSH IN
FROM LAKE SUPERIOR...WITH DEWPOINTS TANKING ONCE AGAIN...WHICH WILL
SET UP A FAIRLY TIGHT DEWPOINT GRADIENT ACROSS THE FORECAST AREA.
CLOUDS AND AN EAST WIND WILL COOL TEMPS DOWN TODAY...AND WILL RANGE
FROM THE UPPER 50S NORTH TO UPPER 60S SOUTH...LOCALLY COOLER NEAR
LAKE MICHIGAN AND THE BAY OF GREEN BAY.
TONIGHT...VERY LITTLE CHANGES INTO TONIGHT. LIGHT RETURN FLOW WILL
BOW THE FRONT NORTHWARD INTO THE NORTHERN MISSISSIPPI VALLEY...WHILE
WE WILL STILL SEE LIGHT EAST FLOW NORTH OF THE BOUNDARY OVER
NORTHERN WISCONSIN. PROGGED SOUNDINGS INDICATE A SIMILAR INVERSION
DEVELOPING TONIGHT WITH A SHALLOW COOL AIRMASS IN PLACE. EVENING
HIGH CLOUDS WILL DEPART BY EARLY IN THE OVERNIGHT PERIOD...WHICH
WILL SUPPORT COOLING IN THE LOW LEVELS AND THE POSSIBILITY OF
STRATUS/FOG REFORMING. WILL INCREASE SKY COVER OVER NORTHEAST
WISCONSIN AND KEEP A MENTION OF PATCHY FOG IN THE FORECAST. LOWS
RANGING FROM THE MID 30S NORTH TO MID 40S SOUTH.
FRIDAY...THE FRONT WILL CONTINUE TO LIFT SLOWLY NORTHWARD ON
FRIDAY...POSSIBLY REACHING INTO CENTRAL WISCONSIN BY LATE IN THE
AFTERNOON. WITHOUT A GOOD PUSH ALOFT THOUGH...SOUTHEAST WINDS AT
THE SURFACE WILL KEEP THE SHALLOW MARINE AIR IN PLACE OVER THE REST
OF THE FORECAST AREA. MOISTURE IN THE 850-750MB LAYER WILL TRY TO
ROTATE INTO CENTRAL WISCONSIN AND THE NAM CREATES SOME ELEVATED CAPE
UP TO AROUND 700 J/KG IN THE AFTERNOON. IF THIS PANS OUT...NOT
SEEING A STRONG ENOUGH TRIGGER TO INITIATE CONVECTION...SO WILL
STICK WITH A DRY FORECAST. HIGHS RANGING FROM THE LOW 50S EAST TO
THE LOWER 70S WEST.
.LONG TERM...FRIDAY NIGHT THRU WEDNESDAY. MAIN FORECAST CONCERNS
ARE DEALING WITH CLOUD/FOG POTENTIAL...TEMPS...AND PRECIP CHANCES.
SUMMER-LIKE PATTERN TO CONTINUE INTO EARLY NEXT WEEK AS UPPER
RIDGE BUILDS ACROSS THE EASTERN CONUS...KEEPING TEMPS WELL ABOVE
NORMAL. AMAZING STRETCH OF LOW/MID 70S ARE EXPECTED SATURDAY
THROUGH TUESDAY...WITH RECORD HIGHS LIKELY. ONLY LOCATIONS NOT
PARTICIPATING IN THE VERY WARM AIR MASS WILL BE NEAR LAKE
MICHIGAN...WHERE TEMPS WILL STRUGGLE TO GET TO 60.
PRECIP CHANCES FAIRLY LOW AS WEAK DISTURBANCES STILL FORECAST TO
RIDE THE BACK SIDE OF THE EASTERN U.S. RIDGE. STILL TOUGH TO TIME
OUT THESE SMALL/WEAK DISTURBANCES THIS FAR IN ADVANCE. SO
CONFIDENCE REMAINS LOW ON THE TIMING/LOCATION OF THESE AND IF
THEY WILL BE ABLE TO GENERATE ANY SHOWER/STORM ACTIVITY. BEST
DISTURBANCE STILL LOOKS TO CROSS INTO THE GREAT LAKES SOMEWHERE
AROUND THE SATURDAY NIGHT TIME FRAME. MODELS HAVE DRIFTED A LITTLE
EAST WITH THIS FEATURE...KEEPING THE MAJORITY OF PRECIP IN LOWER
MICHIGAN. DUE TO THE TIMING/LOCATION CONCERNS...AND LACK OF UPPER
LEVEL SUPPORT...WILL KEEP SLIGHT CHANCE POPS FROM FRIDAY NIGHT
INTO SATURDAY NIGHT TO COVER SMALL THREAT OF SOME PRECIP ACTIVITY.
BY SUNDAY...THE UPPER RIDGE BUILDS OVER THE AREA TO KEEP PRECIP
CHANCES TO THE WEST...CLOSER TO THE DEEP UPPER TROUGH CROSSING
INTO THE PLAINS. THIS SYSTEM WILL BRING A DECENT CHANCE OF
SHOWERS/STORMS TO THE AREA MID-WEEK. STILL SOME DISAGREEMENT WITH
HOW THE MODELS HANDLE THE TROUGH AS IT CUTS OFF IN THE MID-
MISSISSIPPI VALLEY. STILL PLENTY OF TIME TO WORK ON THE DETAILS
WITH THIS SYSTEM...BUT CHANCES FOR WIDESPREAD INCREASE BY
WEDNESDAY.
LAKE MICHIGAN SHOULD SLOWLY LOSE ITS INFLUENCE ON ALL BUT THE
IMMEDIATE LAKESHORE BY SATURDAY AS WINDS TURN MORE SOUTHERLY
BEHIND THE WARM FRONT PUSHING NORTH OF THE AREA. FOG COULD LINGER
ON/NEAR LAKE MICHIGAN THROUGH THE WEEKEND...HOWEVER WILL JUST
CARRY THE MENTION FOR FRIDAY NIGHT AND SATURDAY NIGHT FOR NOW.
&&
.AVIATION...THE LIKELIHOOD OF GETTING WIDESPREAD LOW CLDS AND FOG
IS DECREASING. WL MAINTAIN SOME MVFR FG LATER TNGT...BUT THEN
EXPECT MAINLY VFR CONDITIONS TOMORROW.
SKOWRONSKI
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/BERSCH
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1040 AM CDT THU MAR 15 2012
.UPDATE...
HAVE TRIMMED BACK PRECIP CHANCES THROUGH 1PM. REGIONAL RADAR
TRENDS ALONG WITH RAPID UPDATE RUC GUIDANCE SUGGESTS VERY LITTLE
CHANCE OF PRECIP IN THE SOUTHERN HALF OF THE STATE THROUGH MIDDAY.
HAVE FOLLOWED THIS TREND AND REMOVED MENTION OF PRECIP FOR AREAS
SOUTH OF A LINE FROM RUSSELLVILLE TO JUST NORTH OF SEARCY AND UP
THROUGH ROUGHLY NEWPORT IN THE EAST. NORTH OF THAT LINE...HAVE
ISOLATED TO SCATTERED SHOWER/THUNDERSTORMS MENTIONED THROUGH 1PM.
MADE ONLY SOME SLIGHT ADJUSTMENTS TO THE AFTERNOON/EVENING
POPS...WITH HIGHEST POPS STILL IN THE NORTH AND EAST.
&&
.PREV DISCUSSION... /ISSUED 248 AM CDT THU MAR 15 2012/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
THE NEAR TERM WILL FEATURE A LARGE STORM SYSTEM DIGGING IN THE
SOUTHWEST UNITED STATES...AND A RIDGE BUILDING IN THE SOUTHEAST.
ARKANSAS WILL BE BETWEEN THESE FEATURES...WITH A PERSISTENT
SOUTHWEST WIND FLOW ALOFT...WELL ABOVE NORMAL TEMPERATURES...AND
ENOUGH MOISTURE TO FUEL ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS.
THERE WILL NOT BE MUCH TO TRIGGER PRECIPITATION OTHER THAN AFTERNOON
HEATING. PIECES OF ENERGY WILL PERIODICALLY RIDE THE FLOW INTO
THE REGION...AND THIS WILL LEAD TO MORE ORGANIZED CONVECTION. SUCH
WILL BE THE CASE TODAY...ESPECIALLY IN NORTHERN/CENTRAL ARKANSAS.
IN FACT...A SEVERE STORM OR TWO MAY POP UP. ANOTHER MORE ORGANIZED
EVENT MIGHT UNFOLD FRIDAY NIGHT/SATURDAY MORNING IN THE
NORTH/WEST.
NOT LOOKING FOR WIDESPREAD HEAVY RAIN THROUGH THE WEEKEND. IN
FACT...JUST AS WITH A SUMMERTIME PATTERN...SOME SPOTS MAY NOT GET
ANY RAIN AT ALL GIVEN HIT AND MISS PRECIPITATION.
LONG TERM...MONDAY THROUGH WEDNESDAY
AMPLIFIED PATTERN WILL CONTINUE THROUGH THE EXTENDED...WITH VERY
LITTLE CHANGE TO THE GOING FORECAST. DIURNAL CONVECTION WILL
CONTINUE FOR MONDAY...BEFORE LARGE UPPER LOW OVER THE DESERT
SOUTHWEST WILL SLOWLY MOVE EAST FOR THE MIDDLE OF THE WEEK. HAVE
GONE WITH THE SLOWER EUROPEAN GUIDANCE...WITH RAIN CHANCES
CONTINUING THROUGH THE END OF THE LONG TERM. WITH SOUTHWEST FLOW
PREVAILING...ABOVE NORMAL TEMPERATURES WILL CONTINUE.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 80 61 79 59 / 60 30 30 20
CAMDEN AR 84 62 80 62 / 30 20 10 20
HARRISON AR 79 59 78 59 / 50 20 20 30
HOT SPRINGS AR 81 61 78 61 / 30 20 20 20
LITTLE ROCK AR 83 62 79 60 / 40 20 20 20
MONTICELLO AR 84 62 80 63 / 30 20 10 10
MOUNT IDA AR 79 61 76 60 / 30 20 20 20
MOUNTAIN HOME AR 80 60 79 59 / 60 30 30 30
NEWPORT AR 80 62 79 60 / 50 30 30 20
PINE BLUFF AR 83 62 80 62 / 30 20 10 10
RUSSELLVILLE AR 80 60 78 59 / 40 20 20 30
SEARCY AR 82 61 79 60 / 40 20 20 20
STUTTGART AR 82 61 79 61 / 40 20 20 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
64
AREA FORECAST DISCUSSION
NWS ALBANY NY
641 AM EDT THU MAR 15 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL BRING SCATTERED SHOWERS AND PERHAPS A RUMBLE
OF THUNDER FROM ALBANY NORTH AND WEST EARLY IN THE MORNING. THEN
AFTER A BREAK IN THE ACTION...A STRONGER DISTURBANCE...LINKED WITH A
MID LEVEL WARM FRONT...WILL BRING A BETTER CHANCE OF SHOWERS AND
ANOTHER THUNDERSTORM LATER TONIGHT INTO FRIDAY. HIGH PRESSURE WILL
SLOWLY BUILD IN FRIDAY NIGHT INTO SATURDAY BRING DRIER CONDITIONS
ALONG WITH VERY MILD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM...KEEPING UP WITH THE DISTURBANCE BRINGING ISOLATED TO
SCATTERED SHOWERS FROM THE ADIRONDACKS...SOUTHEAST TO THE CAPITAL
REGION. THERE HAVE BEEN FEW IF ANY CLOUD TO GROUND LIGHTNING STRIKES
IN THE LAST HOUR OR SO. HOWEVER...UPSTREAM...CLOSER TO
ONTARIO...STILL A FEW STRIKES. HAVE WORDED IT SLIGHT CHANCE OF
THUNDER FOR A COUPLE OF HOURS.
TEMPERATURES HAVE BOTTOMED OUT GENERALLY IN THE 30S...EXCEPT 20S
WHERE THERE HAS BEEN SNOW COVER AND CLEAR SKY. IT APPEARS ANY AREAS
GETTING SHOWERS SHOULD BE ABOVE FREEZING.
THE 06Z NAM HAD ABSOLUTELY NO EVIDENCE OF THEM ON THE PLANAR VIEW.
THE LATEST HRRR AND RUC HAD FORECASTED SOME ACTIVITY BUT IN THE
WRONG PLACES AND WRONG TIMES.
THIS SHORT-WAVE...POORLY FORECASTED BY THE MODELS...HAS BEEN
RE-TOOLED IN GFE. THE SHOWERS ASSOCIATED WILL WEAKEN AS IT MOVES
AWAY FROM ITS THETA-E SOURCE.
AFTER THE DISTURBANCE MOVES THROUGH LATER THIS MORNING...IT LOOKS
DRY THROUGH MUCH OF THE AFTERNOON. HOWEVER... A STRONGER DISTURBANCE
EVIDENT ON THE H20 LP OVER THE NORTHWESTERN GREAT LAKES WILL HEAD
TOWARD OUR REGION...BUT NOT UNTIL VERY LATE IN THE DAY OR MORE
LIKELY...EVENING.
THE 11U-3.9U INDICATED MOST OF THE STRATUS HAS NOT MADE INTO OUR
SOUTHERN REGION.
ONCE THE CLOUDS ASSOCIATED WITH THE DISTURBANCE MOVES ON BY TO OUR
SOUTHEAST LATER TODAY...SOME SUNSHINE IS EXPECTED BEFORE CLOUDS TEND
TO INCREASE LATER THIS MORNING BEFORE THE NEXT BATCH OF CLOUDS ROLL
IN.
WE EXPECT HIGH TEMPERATURES SOMEWHAT SIMILAR TO WEDNESDAY/S
GENERALLY IN THE 50S. THE MID HUDSON VALLEY AND LOWER LITCHFIELD
AREA WILL BE COOLER THAN YESTERDAY AS THE WIND FLOW WILL BE
SOUTHEAST...SO THEREFORE NO BENEFICIAL DOWNSLOPE WILL ENSUE OFF THE
CATSKILLS...TOPPING OUT AROUND 60.
ONCE AGAIN HOWEVER...THESE VALUES WILL BE RUNNING AT LEAST 10
DEGREES ABOVE NORMAL FOR MID MARCH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT INTO FRIDAY AFTERNOON...THE AFOREMENTIONED SHORTWAVE ALONG
WITH IT/S WEAK SFC LOW REFLECTION WILL BE MOVING FROM THE GREAT
LAKES SOUTHEASTWARD TOWARDS UPSTATE NY. THIS WILL ALLOW FOR LIKELY
SHOWERS AND THE CHANCE OF THUNDERSTORMS ACROSS OUR AREA...MAINLY
OVERNIGHT. SHOWALTER VALUES CONTINUE SLIGHTLY NEGATIVE...AND MIXED
LAYER MUCAPE VALUES RANGE BETWEEN 0 AND 400 J/KG. WHILE THERE MAY BE
A FEW RUMBLES OF THUNDER AROUND...AND 850-500 HPA LAPSE RATES WILL
BE AROUND 6.5 DEGREES C/KM...IT/S UNLIKELY ANY STORM WOULD BECOME
STRONG DUE TO THE RELATIVELY LOW DEWPOINT TEMPS AND MEAGER CAPE.
OVERNIGHT LOW TEMPERATURES WILL WITH THE CLOUDS AND ANTICIPATED
SHOWER ACTIVITY...OVERNIGHT LOWS WILL BE MILD TONIGHT...WITH MOST
AREAS IN THE UPPER 30S TO MID 40S. TEMPERATURES ON FRIDAY WILL BE A
LITTLE COOLER THAN RECENT DAYS...BUT STILL MILD FOR THIS TIME OF
YEAR...MAINLY IN THE MID OR UPPER 50S. (A FEW READINGS AROUND 60 IN
THE MID HUDSON VALLEY).
BY FRIDAY EVENING...THE DISTURBANCE WILL BE PASSING EAST OF THE
REGION AND A DRYING TREND WILL SET IN. AN UPPER LEVEL RIDGE OVER THE
MIDWEST WILL BUILD INTO THE AREA FOR THE OVERNIGHT
HOURS...ALLOWING THE THREAT FOR SHOWERS TO END. A SURFACE HIGH WILL
BUILDING SOUTHWARD FROM CANADA. THIS SETUP USUALLY POSES A CHALLENGE
TO HOW QUICKLY WE CLEAR OUT...AS MOISTURE COULD EASILY GET TRAPPED
UNDERNEATH AN LOWERING INVERSION. THUS FAR...MODELS ARE OPTIMISTIC
THAT CLOUDS WILL AT LEAST THIN. HOWEVER IF THEY DO...CHANCES FOR FOG
WILL INCREASE. FOR NOW...WENT PARTLY CLOUDY WITH PATCHY FOG.
ASSUMING THIS MIDDLE OF THE ROAD SCENARIO...TEMPERATURES WILL DIP TO
THE MID 30S TO LOWER 40S. IF CLOUDS WERE TO PERSIST...OVERNIGHT LOWS
WOULD BE A LITTLE MILDER. ON THE OTHER HAND...IF WE WERE TO CLEAR
MORE QUICKLY...READINGS COULD DIP A BIT LOWER...ALLOWING MORE
EXTENSIVE FOG TO POSSIBLY FORM.
SATURDAY...HIGH TEMPERATURES WILL TRICKY TO FORECAST. WE ASSUME A
GOOD DEAL OF SUNSHINE. HOWEVER...THE MEAN AIR FLOW WILL BE SSE (AS
OPPOSED TO SSW) SO THERE COULD BE LINGERING MARINE INFLUENCES. THE
MET GUIDANCE (OFF THE NAM MODEL) INDICATED TEMPERATURES ONLY
REACHING THE 50S ON SATURDAY WHILE THE MAV GUIDANCE (BASED OFF THE
GFS MODEL) INDICATE MUCH WARMER READINGS WELL INTO THE 60S...SOME 15
DEGREES HIGHER THAN THE METS IN SOME CASES.
IF LOW CLOUDS WERE TO BACK IN (OR NEVER BURN OFF) THE MET VALUES
WOULD BE MORE CORRECT. HOWEVER...SINCE WE ARE BANKING ON MORE
SUNSHINE...LEANED WITH (BUT NOT QUITE ALL THE WAY) THE WARMER MAV
GUIDANCE. THIS WOULD TRANSLATE TO HIGHS MAINLY IN THE 60S ON
SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
WHILE CONFIDENCE REMAINS ABOVE NORMAL FOR UNSEASONABLY MILD
TEMPERATURES DURING THIS LONG TERM PERIOD OF THE FORECAST...AS
DISCUSSED THIS TIME YESTERDAY...THERE REMAINS CAVEATS THAT COULD
DISRUPT TRANQUIL CONDITIONS.
LATEST GLOBAL MODEL TRENDS CONTINUE TO SUPPORT A TRANQUIL END TO THE
WEEKEND AS BOTH THE SURFACE RIDGE AND POSITIVE HEIGHT ANOMALIES
ALOFT ARE EXPECTED TO BE OVER THE MID ATLANTIC AND NORTHEAST.
THEREAFTER...WE TURN UPSTREAM AS THE COMBINATION OF INCREASED
INSTABILITY AND SHORT WAVE TIMING BECOME INCREASINGLY MORE
PROBLEMATIC.
GFS/ECMWF ARE IN SOME AGREEMENT WITH AN MCS-LIKE FEATURE DEVELOPING
OVER THE MID MISSISSIPPI RIVER VALLEY DURING THIS WEEKEND. THIS MCV
PROPAGATES NORTHWARD ALONG THE BACKSIDE OF THIS DEVELOPING RIDGE
AXIS ALONG THE EASTERN SEABOARD. THIS MCV ATTEMPTS TO FIND A
WEAKNESS IN THE RIDGE AND MOVES ACROSS THE REGION LATE SUNDAY INTO
MONDAY. THIS MAY DISRUPT THE FULL INSOLATION AND KEEP TEMPERATURES
DOWN A LITTLE THAN PREVIOUS FORECASTS ALONG WITH A RENEWED CHANCE
FOR CONVECTION.
BOTH THE GFS AND ECMWF NOW SUGGEST MOISTURE BECOMES TRAPPED UNDER
THOSE INCREASING HEIGHTS ALOFT FOR MORE CLOUD COVER. AS 850MB TEMPS
CLIMB AT OR ABOVE 10C...EVEN WITH THE CLOUDS...WE SHOULD BE ABLE TO
CLIMB INTO THE LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S
FOR THE HIGHER TERRAIN.
THE BEST CHANCE FOR PORTIONS OF THE REGION TO PERHAPS TOUCH THE 80
DEGREE MARK DOES APPEAR TO BE ON WEDNESDAY WITH NEAR +12C AND AN
INCREASE SOUTHERLY FLOW.
AS FOR RECORDS DURING THIS PERIOD...HERE ARE ALBANY STATS...
DATE TEMP YEAR
SUN MAR 18 65 1966
MON MAR 19 75 1894
TUE MAR 20 74 1903
WED MAR 21 78 1921
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
EXTREMELY CHALLENGING FORECAST REMAIN THROUGH TODAY.
A NARROW BAND OF SHOWERS WAS MOVING ACROSS THE MOHAWK VALLEY INTO
THE SOUTHERN PORTIONS OF THE CAPITAL REGION AND TACONICS. THIS WAS
ALONG THE WARM FRONT THAT WAS ATTEMPTING TO LIFT NORTH. ADDITIONAL
SHOWERS ARE SEEN UPSTREAM BUT IT REMAINS UNCLEAR JUST HOW MUCH WILL
MIGRATE SOUTH AND IMPACT THE TAF SITES. WE WILL CONTINUE WITH THE
VCSH UNTIL TRENDS BECOME MORE EVIDENT.
NEXT ISSUE IS THE CLOUD COVER. AS SEEN IN THE 11U-3.9U
IMAGERY...THE EDGE OF THE IFR CIGS WERE CLOSE TO KGFL AND KPOU /KGFL
JUST WENT INTO IFR/. ONCE THE MARCH SUNSHINE IS ABLE TO HEAT THE
BOUNDARY LAYER...WE SHOULD SEE THIS CIG RISE ABOVE IFR THRESHOLDS
AND WILL DO SO IN THE TAF FORECAST THIS MORNING WITH A TEMPO GROUP
FOR IFR CIGS.
WINDS THIS MORNING ARE LIGHT AND GENERALLY NORTHEAST TO EAST...WITH
EXPECTATIONS FOR THOSE WINDS TO SHIFT TOWARD A SOUTHEAST DIRECTION
AT SPEEDS 10KTS OR LESS.
OUTLOOK...
THU OVERNIGHT...MVFR/IFR...-SHRA. ISOLD -TSRA.
FRI-FRI EVENING...MVFR...SCT-NUMEROUS -SHRA AND ISOLD -TSRA.
FRI NT-SUN...VFR. NO SIG WX.
SUN NT-MON...VFR/MVFR. CHC -SHRA/-TSRA.
&&
.FIRE WEATHER...
RH VALUES WILL REMAIN HIGHER THAN YESTERDAY...BOTTOMING IN THE
MODERATE RANGE (40-60 PERCENT). 10 METER WINDS WILL BE SOUTH OR
SOUTHEAST GENERALLY AROUND 10 MPH OR LESS. THERE WILL ISOLATED
SHOWERS AND POSSIBLY A THUNDERSTORM THIS MORNING AND POSSIBLY BY
LATE IN THE DAY. MOST OF THE DAY WILL BE RAINFREE AND ANY RAINFALL
WILL AVERAGE WELL BELOW A QUARTER OF AN INCH.
THERE WILL BE MORE CLOUDS THAN WEDNESDAY BUT ALSO TIMES OF
SUNSHINE...ESPECIALLY MIDDAY.
SHOWERS WILL BECOME MORE LIKELY LATER TONIGHT AND FRIDAY AS A
DISTURBANCE AND ELEVATED WARM FRONT MOVE ACROSS THE REGION. A
QUARTER OF AN INCH OF RAIN OR MORE IS POSSIBLE...ESPECIALLY NORTH
AND WEST OF ALBANY. RH LEVELS WILL REMAIN ELEVATED ON FRIDAY
(GENERALLY HIGHER THAN 60 PERCENT).
DRY WEATHER RETURNS FRIDAY NIGHT INTO THE WEEKEND. IT WILL BECOME
UNSEASONABLY WARM WITH SOME SUNSHINE EXPECTED BOTH WEEKEND DAYS.
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE NEXT MONDAY.
&&
.HYDROLOGY...
NO HYDROLOGIC ISSUES ARE ANTICIPATED OVER THE NEXT 5 DAYS.
ISOLATED SHOWERS AND THUNDERSTORMS SHOULD HAVE NO EFFECT ON RUNOFF.
IN FACT...IN SOME CASES THE PRECIPITATION MIGHT FALL AS FREEZING
RAIN (ALBEIT VERY LIGHT).
MORE SHOWER ACTIVITY IS LIKELY TONIGHT INTO EARLY FRIDAY. AT THIS
POINT RAINFALL AMOUNTS LOOK FAIRLY LIGHT...PERHAPS APPROACHING HALF
AN INCH IN OUR NORTHWESTERN ZONES...BUT GENERALLY AROUND A QUARTER
OF AN INCH OR LESS THROUGH THE REMAINDER OF OUR HYDROLOGICAL
FORECAST AREA.
THIS RAINFALL COULD PRODUCE WELL WITHIN BANK RISES ON SOME STREAMS
AND RIVERS...ESPECIALLY THOSE NORTHWEST OF ALBANY.
THE LATEST NOHRSC MODELED SNOW COVERAGE CONTINUES TO SHOW SEVERAL
INCHES OF WATER EQUIVALENT ACROSS THE ADIRONDACKS AND GREEN
MOUNTAINS. ALTHOUGH NOT MODELED...SOME SMALL AMOUNTS OF SNOW ARE
STILL PROBABLY IN PLACE ACROSS THE HIGHEST ELEVATIONS OF THE
BERKSHIRES...AND HIGH PEAKS OF THE CATSKILLS IN GREENE AND ULSTER
COUNTIES. WARM TEMPERATURES DURING THE DAYTIME HOURS OVER THE NEXT
SEVERAL DAYS...ESPECIALLY THIS WEEKEND...WILL ALLOW FOR CONTINUED
SNOW MELT...ALTHOUGH RATES SHOULD SLOW DOWN AT NIGHT WITH
TEMPERATURES DROPPING INTO THE 30S TO LOW 40S ACROSS THE HIGH
TERRAIN. BECAUSE OF THIS GRADUAL MELTING...AND NO HEAVY
PRECIPITATION EXPECTED ANYTIME SOON...NO RIVER PROBLEMS ARE
ANTICIPATED...AND THE SHORT-TERM HYDROLOGIC ENSEMBLE SHOWS NO RIVERS
IN OUR AREA EVEN REACHING ACTION STAGE OVER THE NEXT SEVERAL DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...FRUGIS/HWJIV
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
638 AM EDT THU MAR 15 2012
.SYNOPSIS...
A WEAK DISTURBANCE WILL BRING SCATTERED SHOWERS AND PERHAPS A RUMBLE
OF THUNDER FROM ALBANY NORTH AND WEST EARLY IN THE MORNING. THEN
AFTER A BREAK IN THE ACTION...A STRONGER DISTURBANCE...LINKED WITH A
MID LEVEL WARM FRONT...WILL BRING A BETTER CHANCE OF SHOWERS AND
ANOTHER THUNDERSTORM LATER TONIGHT INTO FRIDAY. HIGH PRESSURE WILL
SLOWLY BUILD IN FRIDAY NIGHT INTO SATURDAY BRING DRIER CONDITIONS
ALONG WITH VERY MILD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 530 AM...SHOWERS AND ISOLATED THUNDERSTORMS MOVING QUICKLY
INTO THE MOHAWK VALLEY. THE 06Z NAM HAD ABSOLUTELY NO EVIDENCE OF
THEM ON THE PLANAR VIEW. THE LATEST HRRR AND RUC HAD FORECASTED SOME
ACTIVITY BUT IN THE WRONG PLACES AND WRONG TIMES.
THIS SHORT-WAVE...POORLY FORECASTED BY THE MODELS...HAS BEEN
RE-TOOLED IN GFE. WE ARE THINKING IT WILL WEAKEN AS IT MOVES AWAY
FROM ITS THETA-E SOURCE BUT STILL CARRY ISOLATED ACTIVITY PAST THE
GREATER CAPITAL DISTRICT THROUGH AT LEAST EARLY MORNING. THIS
ACTIVITY NOW STRETCHES BACK BEYOND LAKE ONTARIO SO WE MIGHT HAVE TO
EXTEND IT EVEN FURTHER INTO THE MORNING.
TEMPERATURES THIS MORNING WERE GENERALLY COLDER THIS MORNING THAN
PAST MORNING...AND IN SOME CASES...BELOW FREEZING (LIKE GLENS
FALLS). CONCERN IS THAT WITH SHOWERS MOVING INTO THESE REGIONS THERE
IS A REMOTE POSSIBILITY THAT FREEZING RAIN COULD FALL. WE WILL
MONITOR AND ISSUE MORE SPECIAL WEATHER STATEMENTS AS NEEDED.
AFTER THE DISTURBANCE MOVES THROUGH LATER THIS MORNING...IT LOOKS
DRY THROUGH MUCH OF THE AFTERNOON. HOWEVER... A STRONGER DISTURBANCE
EVIDENT ON THE H20 LP OVER THE NORTHWESTERN GREAT LAKES WILL HEAD
TOWARD OUR REGION...BUT NOT UNTIL VERY LATE IN THE DAY OR MORE
LIKELY...EVENING.
THE 11U-3.9U INDICATES THE STRATUS HAS NOT MADE MUCH PROGRESS
NORTHWARD OF LONG ISLAND WHILE AC AHEAD OF THE SHOWERS AND
THUNDERSTORMS WERE WORKING ACROSS THE MOHAWK VALLEY.
ONCE CLOUDS ASSOCIATED WITH THE DISTURBANCE MOVES ON BY TO OUR
SOUTHEAST LATER TODAY...SOME SUNSHINE IS EXPECTED BEFORE CLOUDS TEND
TO INCREASE LATER THIS MORNING BEFORE THE NEXT BATCH OF CLOUDS ROLL
IN.
WE EXPECT HIGH TEMPERATURES SOMEWHAT SIMILAR TO WEDNESDAY/S
GENERALLY IN THE 50S. THE MID HUDSON VALLEY AND LOWER LITCHFIELD
AREA WILL BE COOLER THAN YESTERDAY AS THE WIND FLOW WILL BE
SOUTHEAST...SO THEREFORE NO BENEFICIAL DOWNSLOPE WILL ENSUE OFF THE
CATSKILLS...TOPPING OUT AROUND 60.
ONCE AGAIN HOWEVER...THESE VALUES WILL BE RUNNING AT LEAST 10
DEGREES ABOVE NORMAL FOR MID MARCH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT INTO FRIDAY AFTERNOON...THE AFOREMENTIONED SHORTWAVE ALONG
WITH IT/S WEAK SFC LOW REFLECTION WILL BE MOVING FROM THE GREAT
LAKES SOUTHEASTWARD TOWARDS UPSTATE NY. THIS WILL ALLOW FOR LIKELY
SHOWERS AND THE CHANCE OF THUNDERSTORMS ACROSS OUR AREA...MAINLY
OVERNIGHT. SHOWALTER VALUES CONTINUE SLIGHTLY NEGATIVE...AND MIXED
LAYER MUCAPE VALUES RANGE BETWEEN 0 AND 400 J/KG. WHILE THERE MAY BE
A FEW RUMBLES OF THUNDER AROUND...AND 850-500 HPA LAPSE RATES WILL
BE AROUND 6.5 DEGREES C/KM...IT/S UNLIKELY ANY STORM WOULD BECOME
STRONG DUE TO THE RELATIVELY LOW DEWPOINT TEMPS AND MEAGER CAPE.
OVERNIGHT LOW TEMPERATURES WILL WITH THE CLOUDS AND ANTICIPATED
SHOWER ACTIVITY...OVERNIGHT LOWS WILL BE MILD TONIGHT...WITH MOST
AREAS IN THE UPPER 30S TO MID 40S. TEMPERATURES ON FRIDAY WILL BE A
LITTLE COOLER THAN RECENT DAYS...BUT STILL MILD FOR THIS TIME OF
YEAR...MAINLY IN THE MID OR UPPER 50S. (A FEW READINGS AROUND 60 IN
THE MID HUDSON VALLEY).
BY FRIDAY EVENING...THE DISTURBANCE WILL BE PASSING EAST OF THE
REGION AND A DRYING TREND WILL SET IN. AN UPPER LEVEL RIDGE OVER THE
MIDWEST WILL BUILD INTO THE AREA FOR THE OVERNIGHT
HOURS...ALLOWING THE THREAT FOR SHOWERS TO END. A SURFACE HIGH WILL
BUILDING SOUTHWARD FROM CANADA. THIS SETUP USUALLY POSES A CHALLENGE
TO HOW QUICKLY WE CLEAR OUT...AS MOISTURE COULD EASILY GET TRAPPED
UNDERNEATH AN LOWERING INVERSION. THUS FAR...MODELS ARE OPTIMISTIC
THAT CLOUDS WILL AT LEAST THIN. HOWEVER IF THEY DO...CHANCES FOR FOG
WILL INCREASE. FOR NOW...WENT PARTLY CLOUDY WITH PATCHY FOG.
ASSUMING THIS MIDDLE OF THE ROAD SCENARIO...TEMPERATURES WILL DIP TO
THE MID 30S TO LOWER 40S. IF CLOUDS WERE TO PERSIST...OVERNIGHT LOWS
WOULD BE A LITTLE MILDER. ON THE OTHER HAND...IF WE WERE TO CLEAR
MORE QUICKLY...READINGS COULD DIP A BIT LOWER...ALLOWING MORE
EXTENSIVE FOG TO POSSIBLY FORM.
SATURDAY...HIGH TEMPERATURES WILL TRICKY TO FORECAST. WE ASSUME A
GOOD DEAL OF SUNSHINE. HOWEVER...THE MEAN AIR FLOW WILL BE SSE (AS
OPPOSED TO SSW) SO THERE COULD BE LINGERING MARINE INFLUENCES. THE
MET GUIDANCE (OFF THE NAM MODEL) INDICATED TEMPERATURES ONLY
REACHING THE 50S ON SATURDAY WHILE THE MAV GUIDANCE (BASED OFF THE
GFS MODEL) INDICATE MUCH WARMER READINGS WELL INTO THE 60S...SOME 15
DEGREES HIGHER THAN THE METS IN SOME CASES.
IF LOW CLOUDS WERE TO BACK IN (OR NEVER BURN OFF) THE MET VALUES
WOULD BE MORE CORRECT. HOWEVER...SINCE WE ARE BANKING ON MORE
SUNSHINE...LEANED WITH (BUT NOT QUITE ALL THE WAY) THE WARMER MAV
GUIDANCE. THIS WOULD TRANSLATE TO HIGHS MAINLY IN THE 60S ON
SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
WHILE CONFIDENCE REMAINS ABOVE NORMAL FOR UNSEASONABLY MILD
TEMPERATURES DURING THIS LONG TERM PERIOD OF THE FORECAST...AS
DISCUSSED THIS TIME YESTERDAY...THERE REMAINS CAVEATS THAT COULD
DISRUPT TRANQUIL CONDITIONS.
LATEST GLOBAL MODEL TRENDS CONTINUE TO SUPPORT A TRANQUIL END TO THE
WEEKEND AS BOTH THE SURFACE RIDGE AND POSITIVE HEIGHT ANOMALIES
ALOFT ARE EXPECTED TO BE OVER THE MID ATLANTIC AND NORTHEAST.
THEREAFTER...WE TURN UPSTREAM AS THE COMBINATION OF INCREASED
INSTABILITY AND SHORT WAVE TIMING BECOME INCREASINGLY MORE
PROBLEMATIC.
GFS/ECMWF ARE IN SOME AGREEMENT WITH AN MCS-LIKE FEATURE DEVELOPING
OVER THE MID MISSISSIPPI RIVER VALLEY DURING THIS WEEKEND. THIS MCV
PROPAGATES NORTHWARD ALONG THE BACKSIDE OF THIS DEVELOPING RIDGE
AXIS ALONG THE EASTERN SEABOARD. THIS MCV ATTEMPTS TO FIND A
WEAKNESS IN THE RIDGE AND MOVES ACROSS THE REGION LATE SUNDAY INTO
MONDAY. THIS MAY DISRUPT THE FULL INSOLATION AND KEEP TEMPERATURES
DOWN A LITTLE THAN PREVIOUS FORECASTS ALONG WITH A RENEWED CHANCE
FOR CONVECTION.
BOTH THE GFS AND ECMWF NOW SUGGEST MOISTURE BECOMES TRAPPED UNDER
THOSE INCREASING HEIGHTS ALOFT FOR MORE CLOUD COVER. AS 850MB TEMPS
CLIMB AT OR ABOVE 10C...EVEN WITH THE CLOUDS...WE SHOULD BE ABLE TO
CLIMB INTO THE LOWER HALF OF THE 70S FOR VALLEY LOCATIONS AND 60S
FOR THE HIGHER TERRAIN.
THE BEST CHANCE FOR PORTIONS OF THE REGION TO PERHAPS TOUCH THE 80
DEGREE MARK DOES APPEAR TO BE ON WEDNESDAY WITH NEAR +12C AND AN
INCREASE SOUTHERLY FLOW.
AS FOR RECORDS DURING THIS PERIOD...HERE ARE ALBANY STATS...
DATE TEMP YEAR
SUN MAR 18 65 1966
MON MAR 19 75 1894
TUE MAR 20 74 1903
WED MAR 21 78 1921
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
EXTREMELY CHALLENGING FORECAST REMAIN THROUGH TODAY.
A NARROW BAND OF SHOWERS WAS MOVING ACROSS THE MOHAWK VALLEY INTO
THE SOUTHERN PORTIONS OF THE CAPITAL REGION AND TACONICS. THIS WAS
ALONG THE WARM FRONT THAT WAS ATTEMPTING TO LIFT NORTH. ADDITIONAL
SHOWERS ARE SEEN UPSTREAM BUT IT REMAINS UNCLEAR JUST HOW MUCH WILL
MIGRATE SOUTH AND IMPACT THE TAF SITES. WE WILL CONTINUE WITH THE
VCSH UNTIL TRENDS BECOME MORE EVIDENT.
NEXT ISSUE IS THE CLOUD COVER. AS SEEN IN THE 11U-3.9U
IMAGERY...THE EDGE OF THE IFR CIGS WERE CLOSE TO KGFL AND KPOU /KGFL
JUST WENT INTO IFR/. ONCE THE MARCH SUNSHINE IS ABLE TO HEAT THE
BOUNDARY LAYER...WE SHOULD SEE THIS CIG RISE ABOVE IFR THRESHOLDS
AND WILL DO SO IN THE TAF FORECAST THIS MORNING WITH A TEMPO GROUP
FOR IFR CIGS.
WINDS THIS MORNING ARE LIGHT AND GENERALLY NORTHEAST TO EAST...WITH
EXPECTATIONS FOR THOSE WINDS TO SHIFT TOWARD A SOUTHEAST DIRECTION
AT SPEEDS 10KTS OR LESS.
OUTLOOK...
THU OVERNIGHT...MVFR/IFR...-SHRA. ISOLD -TSRA.
FRI-FRI EVENING...MVFR...SCT-NUMEROUS -SHRA AND ISOLD -TSRA.
FRI NT-SUN...VFR. NO SIG WX.
SUN NT-MON...VFR/MVFR. CHC -SHRA/-TSRA.
&&
.FIRE WEATHER...
RH VALUES WILL REMAIN HIGHER THAN YESTERDAY...BOTTOMING IN THE
MODERATE RANGE (40-60 PERCENT). 10 METER WINDS WILL BE SOUTH OR
SOUTHEAST GENERALLY AROUND 10 MPH OR LESS. THERE WILL ISOLATED
SHOWERS AND POSSIBLY A THUNDERSTORM THIS MORNING AND POSSIBLY BY
LATE IN THE DAY. MOST OF THE DAY WILL BE RAINFREE AND ANY RAINFALL
WILL AVERAGE WELL BELOW A QUARTER OF AN INCH.
THERE WILL BE MORE CLOUDS THAN WEDNESDAY BUT ALSO TIMES OF
SUNSHINE...ESPECIALLY MIDDAY.
SHOWERS WILL BECOME MORE LIKELY LATER TONIGHT AND FRIDAY AS A
DISTURBANCE AND ELEVATED WARM FRONT MOVE ACROSS THE REGION. A
QUARTER OF AN INCH OF RAIN OR MORE IS POSSIBLE...ESPECIALLY NORTH
AND WEST OF ALBANY. RH LEVELS WILL REMAIN ELEVATED ON FRIDAY
(GENERALLY HIGHER THAN 60 PERCENT).
DRY WEATHER RETURNS FRIDAY NIGHT INTO THE WEEKEND. IT WILL BECOME
UNSEASONABLY WARM WITH SOME SUNSHINE EXPECTED BOTH WEEKEND DAYS.
THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE NEXT MONDAY.
&&
.HYDROLOGY...
NO HYDROLOGIC ISSUES ARE ANTICIPATED OVER THE NEXT 5 DAYS.
ISOLATED SHOWERS AND THUNDERSTORMS SHOULD HAVE NO EFFECT ON RUNOFF.
IN FACT...IN SOME CASES THE PRECIPITATION MIGHT FALL AS FREEZING
RAIN (ALBEIT VERY LIGHT).
MORE SHOWER ACTIVITY IS LIKELY TONIGHT INTO EARLY FRIDAY. AT THIS
POINT RAINFALL AMOUNTS LOOK FAIRLY LIGHT...PERHAPS APPROACHING HALF
AN INCH IN OUR NORTHWESTERN ZONES...BUT GENERALLY AROUND A QUARTER
OF AN INCH OR LESS THROUGH THE REMAINDER OF OUR HYDROLOGICAL
FORECAST AREA.
THIS RAINFALL COULD PRODUCE WELL WITHIN BANK RISES ON SOME STREAMS
AND RIVERS...ESPECIALLY THOSE NORTHWEST OF ALBANY.
THE LATEST NOHRSC MODELED SNOW COVERAGE CONTINUES TO SHOW SEVERAL
INCHES OF WATER EQUIVALENT ACROSS THE ADIRONDACKS AND GREEN
MOUNTAINS. ALTHOUGH NOT MODELED...SOME SMALL AMOUNTS OF SNOW ARE
STILL PROBABLY IN PLACE ACROSS THE HIGHEST ELEVATIONS OF THE
BERKSHIRES...AND HIGH PEAKS OF THE CATSKILLS IN GREENE AND ULSTER
COUNTIES. WARM TEMPERATURES DURING THE DAYTIME HOURS OVER THE NEXT
SEVERAL DAYS...ESPECIALLY THIS WEEKEND...WILL ALLOW FOR CONTINUED
SNOW MELT...ALTHOUGH RATES SHOULD SLOW DOWN AT NIGHT WITH
TEMPERATURES DROPPING INTO THE 30S TO LOW 40S ACROSS THE HIGH
TERRAIN. BECAUSE OF THIS GRADUAL MELTING...AND NO HEAVY
PRECIPITATION EXPECTED ANYTIME SOON...NO RIVER PROBLEMS ARE
ANTICIPATED...AND THE SHORT-TERM HYDROLOGIC ENSEMBLE SHOWS NO RIVERS
IN OUR AREA EVEN REACHING ACTION STAGE OVER THE NEXT SEVERAL DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...FRUGIS/HWJIV
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
926 AM EDT THU MAR 15 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM MOVING SLOWLY EASTWARD THROUGH THE GREAT
LAKES WILL PROVIDE SHOWERS AND SCATTERED THUNDERSTORMS INTO FRIDAY
NIGHT. TEMPERATURES WILL REMAIN UNSEASONABLY WARM INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE MADE TO CLOUDS AND SHOWER PROSPECTS PER RECENT RADAR AND SURFACE
DATA AND HRRR AND NAM MODEL OUTPUT. RECENT SATELLITE DATA SHOWS
THICKER CLOUDS HAVE REACHED THE MOUNTAINS. EXPECT WARM FRONTAL
BAND OF SHOWERS AND SCATTERED THUNDERSTORMS TO CONTINUE EAST INTO
WESTERN PENNSYLVANIA, BUT DECREASE IN COVERAGE.
MADE SMALL ADJUSTMENTS TO TEMPERATURES PER RECENT OBSERVED
COOLING WHERE SHOWERS HAVE RECENTLY PASSED, AND EXPECTED REBOUND
PER RECENT HRRR AND NAM MODEL OUTPUT.
7AM UPDATE... PROGRESS LINE OF THUNDERSTORMS HAS SLOWED/NEARLY
STOPPED MOVING EASTWARD AND CONVECTIONS BUILDING TO THE WEST.
LOWER DEWPOINTS EAST AND MOISTURE FLUX MORE FAVORABLE TO THE WEST.
UPDATED GRIDS TO REFLECT THE SLOWER PROGRESSION. LASTEST HRRR
TENDS TO WASH OUT THE PRECIP BY THE NOON HOUR. ADJUSTED CLOUDS
GRIDS TO REFLECT THE MID AND HIGH LEVEL CLOUDS BLOWING OFF OF THE
THUNDERSTORMS.
WILL CONTINUE A CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT.
SPC CONTINUES TO PROJECT A SLIGHT RISK OF SEVERE THUNDERSTORMS AS
FAR EAST AS THE I-77 CORRIDOR IN OHIO. RECENT RUC MODEL PROFILES
SHOW INSTABILITY DEVELOPING ALOFT TODAY. HOWEVER, VERTICAL WIND SHEAR
REMAINS WEAK, WHICH COULD PRECLUDE EXTENT OF SEVERE DEVELOPMENT.
THE THREAT OF THUNDERSTORMS WILL DIMINISH AFTER MIDNIGHT TONIGHT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
UNSETTLED PATTERN WILL PERSIST THROUGH THE MIDDLE PART OF THE
WEEKEND. AS SHORTWAVES MOVE ACROSS UPPER LEVEL RIDGE PARKED OVER THE
EAST COAST...THIS WILL TEMPORARILY ENHANCE CHANCES FOR
PRECIPITATION.
AS LOW PRESSURE MOVES EASTWARD INTO NEW ENGLAND FRIDAY
NIGHT...THIS MAY ALLOW FOR THE BEST CHANCE OF PRECIP IN THE
PERIOD. MODELS ARE SHOWING LITTLE CONSISTENCY WITH INSTABILITY FOR
THUNDERSTORMS. HAVE GENERALLY GONE WITH CHANCE STORMS DURING THE
AFTERNOON AND EVENING...AND SLIGHT CHANCE DURING THE OVERNIGHT AND
MORNING HOURS. NO CHANGE IN THE TREND OF WELL ABOVE NORMAL
TEMPERATURES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AN UPPER RIDGE WILL AMPLIFY ACROSS THE EASTERN STATES EARLY NEXT
WEEK AND REMAIN IN PLACE THROUGH WEDNESDAY. SURFACE HIGH PRESSURE IS
PROGGED TO HOLD ALONG THE MID ATLANTIC COAST AND MAINTAIN SOUTHWEST
FLOW ACROSS THE UPPER OHIO VALLEY REGION.
ISOLATED SHOWERS CAN STILL BE EXPECTED SUNDAY...WITH GENERALLY DRY
WEATHER MONDAY THROUGH WEDNESDAY. TEMPERATURES WILL REMAIN 20 TO 25
DEGREES ABOVE NORMAL FOR THE EXTENDED PERIOD.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS WILL CONTINUE ACROSS THE TERMINALS THROUGH THE TAF
PERIOD. BROKEN CUMULUS IS EXPECTED TO FORM, AROUND DAWN IN THE FAR
WEST AND LATER IN THE MORNING FOR REMAINING PORTS, AS LOW LEVEL
MOISTURE INCREASES AHEAD OF AN APPROACHING SHORTWAVE TROUGH.
CURRENT HIRES MODEL DATA IS SHOWING A LINE OF SHOWERS/ISO STORMS
DEVELOPING MOVING THROUGH OHIO BTWN 12Z AND 16Z, AND ACROSS THE
REMAINDER OF THE FORECAST AREA BTWN 16Z AND 20Z. WILL INSERT TEMPO
GROUPS AT EACH PORT TO TIME THIS ACTIVITY.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
SCATTERED SHOWERS AND THUNDERSTORMS AND THE POTENTIAL FOR
RESTRICTIONS WILL CONTINUE THROUGH EARLY SATURDAY AS THE UPPER
TROUGH AND ASSOCIATED WEAK SURFACE LOW MOVE EAST TO THE ATLANTIC
COAST. SHOWERS ARE EXPECTED TO BECOME MORE ISOLATED BY SUNDAY UNDER
WEAK RIDGING.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
734 AM EDT THU MAR 15 2012
.SYNOPSIS...
ISSUED AT 405 AM EDT THU MAR 15 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WSW FLOW ALF FM
THE PAC NW TO ONTARIO BTWN UPR RDG MOVING SLOWLY E THRU THE GREAT
LKS AND A LARGER SCALE TROF OFF THE W COAST. SFC COOL FNT ATTENDANT
TO STRONG SHRTWV LIFTING NEWD THRU HUDSON BAY IS MOVING E THRU UPR
MI EARLY THIS MRNG AND WL BRING AT LEAST A TEMPORARY END TO RECORD
WARMTH THAT ENVELOPED THE AREA ON WED...WHEN THE MERCURY PEAKED IN
THE 70S AT MANY SPOTS AND AS HI AS 77 AT KENTON. THERE WAS A SURGE
OF LLVL MSTR MOVING NEWD AHEAD OF THIS COOL FNT...AND SOME FOG AND
SC HAVE DVLPD OVER THE SE HALF OF THE CWA AHEAD OF THE COOL FNT.
ALTHOUGH THE 00Z GRB RAOB SHOWS STEEP H8-5 LAPSE RATES NOT FAR FM
DRY ADIABATIC...THE DRYNESS OF THE MID LVLS AND A SHARP INVRN NEAR
H8 THAT HAS CAPPED THE LLVL MOISTENING/DESTABILIZATION AND HELD IN
THE ABSENCE OF ANY DYNAMIC SUPPORT SO FAR S OF THE HUDSON BAY SHRTWV
HAVE CONSPIRED TO PREVENT THE DEVELOPMENT OF ANY SHRA/TS. BEHIND THE
FNT...HI PRES IN THE NRN PLAINS IS TENDING TO BUILD TO THE ENE. THE
00Z INL RAOB DEPICTS A VERY DRY LOWER TROP WITH H925/H85 DEWPT
DEPRESSIONS OF 18C/22C. SFC DEWPTS HAVE FALLEN INTO THE TEENS OVER
THE N HALF OF MN. ALTHOUGH THE COOL FNT PASSED IWD/CMX IN THE EARLY
EVNG...SFC DEWPTS THERE ARE STILL IN THE MID 30S. OVER THE S HALF OF
MN...SFC DEWPTS REMAIN AS HI AS 45 EVEN BEHIND THE FROPA. BUT EXCEPT
FOR SOME HI CLDS...SKIES ARE MOCLR AS THE 00Z MPX RAOB IS QUITE DRY
IN A RELATIVE SENSE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
TDAY...MAIN FCST CONCERNS IN THE SHORT TERM RELATE TO THE EXTENT OF
THE LLVL DRYING THAT WL OCCUR OVER THE CWA IN THE WAKE OF THE COOL
FNT THAT IS FCST TO CLEAR THE SE ZNS BY FCST ISSUANCE. MODELS IN
RECENT DAYS HAVE SHOWN SOME DISAGREEMENT ON THIS DRYING BECAUSE THE
FLOW ALF IS EXPECTED TO REMAIN WSW AND TAKE THE SFC HI PRES/CORE OF
THE REALLY DRY AIR NOW IN NW MN INTO ONTARIO. BUT EVEN IF THE LLVL
AIRMASS MOVING INTO UPR MI COMES FM THE DIRECTION OF MPX...THE
RELATIVE DRYNESS OF THE AIRMASS THERE IS A GOOD INDICATION LO CLDS
ARE LESS LIKELY TO DEVELOP THAN PREVIOUSLY FCST. WITH THE EXCEPTION
OF THE GFS...THE 00Z RUNS HAVE COME INTO GOOD AGREEMENT SHOWING MORE
DRYING IN THE H95-9 LYR THRU THE DAY. GIVEN THE DRYNESS/LACK OF CLDS
UPSTREAM AND DIFFLUENT NATURE OF THE FLOW...WL FOLLOW THE 00Z LOCAL
WRF-ARW THAT INDICATES MORE AGGRESSIVE LLVL DRYING AND CUT BACK ON
THE EXTENT OF THE LO CLDS. THIS MODEL DOES INDICATE SOME LO CLDS MAY
LINGER OVER THE E THIS MRNG IN THE WAKE OF THE FROPA...BUT OTRW
INDICATES THE DAY SHOULD BE MOSUNNY EXCEPT FOR SOME HI CLDS. MIXING
TO H85 ON WRF-ARW SDNGS INDICATES HI TEMPS WL TOP OUT ARND 60 OVER
LOCATIONS NEAR THE WI BORDER WELL INLAND FM LK SUP COOLING IN THE
LLVL N-NE FLOW. HI TEMPS ARE LIKELY TO HOLD IN THE 40S NEAR LK SUP E
OF THE KEWEENAW WITH ONSHORE 15KT NE H925 WINDS.
TNGT...ALTHOUGH A WEAK SHRTWV IS PROGGED TO RIPPLE THRU THE UPR
FLOW...THE MID LVLS ARE TOO DRY FOR ANY PCPN. IN FACT...FCST
SOUNDINGS INDICATE ONLY SOME HI CLDS. EXPECT A HEALTHY DIURNAL TEMP
FALL WITH LIGHT WINDS. THE LOWEST MIN TEMPS ARE LIKELY OVER THE
INTERIOR E AND CNTRL WHERE THE WINDS WL BE LIGHTEST THRU THE NGT.
INCRSG S WIND LATER AS HI PRES RDG BEGINS TO RETREAT TO THE E WL
LIKELY KEEP TEMPS A BIT ELEVATED OVER THE FAR W FM IWD TO ONTONAGON.
THE LOCAL WRF-ARW FCST SDNGS INDICATE THE BEST CHC FOR FOG WL BE
OVER THE E...WHERE A BIT MORE AMPLE LLVL MSTR WL COINCIDE WITH THE
LGT WINDS.
FRI...SFC HI CENTER IS FCST TO DRIFT INTO QUEBEC...WITH INCRSG SLY
FLOW UNDER SHARPENING PRES GRADIENT BTWN THE DEPARTING HI AND
FALLING PRES IN THE PLAINS. THE RETURN OF HIER H95-9 SPECIFIC
HUMIDITY WL RESULT IN SOME AFTN CU/SC. WITH H85 TEMPS FCST TO
REBOUND TO ARND 12C...TEMPS WL REBOUND INTO THE 60S AWAY FM LK
MODERATION...WARMEST OVER THE W WHERE THE SSE SFC FLOW DOWNSLOPES.
FRI NGT...SSW H925 WINDS INCRSG UP TO 25-35 KTS ON THE WRN FLANK OF
RETREATING HI PRES ARE FCST TO BRING MORE LLVL MSTR SURGING INTO THE
UPR LKS. ALTHOUGH MODELS GENERATE SPOTTY QPF...GFS FCST SDNGS SHOW
CAPPING INVRN LINGERING BTWN H8-75 IN THE ABSENCE OF ANY DYNAMIC
SUPPORT WITHIN UPR RDG AXIS. SO OPTED TO KEEP GOING DRY FCST. SOME
FOG IS LIKELY OVER THE E IN AREAS DOWNWIND OF LK MI EVEN THOUGH THE
STRONG WINDS/LLVL MOISTENING WL RETARD THE DIURNAL FALL OF TEMP.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
UPPER RIDGE WILL BE IN CONTROL OF THE REGION AT THE START OF THE
PERIOD AND CONTINUE THROUGH THE FIRST HALF OF NEXT WEEK.
AT THE SFC...AREA WILL BE BETWEEN A COLD FRONT OVER THE ERN DAKOTAS
AND SFC HIGH MOVING E INTO THE NEW ENGLAND STATES. THIS WILL ALLOW
SRLY FLOW TO BE IN PLACE AND MODELS SHOWING GOOD H950-850 MOISTURE
SURGING NNE OVER THE AREA FRI NIGHT AND INTO SAT. IF THIS MOISTURE
IS PRESENT AND LOW CLOUDS FORM...COULD BE DIFFICULT TO BREAK OUT ON
SATURDAY IF THIS OCCURS. BUT LATEST TRENDS IN NAM/GFS ARE SHOWING
MORE MIXING PRESENT AND FEEL A PARTLY CLOUDY FORECAST IS WARRENTED
FOR ALL BUT NEAR LK MI...WHERE FOG ON SAT MORNING WILL KEEP THINGS
MOSTLY CLOUDY. THIS MAKES TEMPS TRICKY...AS IT WILL DEPEND ON THE
CLOUDS BREAKING OUT. THINK THE WEST HALF HAS A BETTER CHANCE OF THIS
OCCURRING AND TRENDED TOWARDS THE WARM SIDE. MIXING TO H900 WOULD
GIVE HIGHS NEAR 70S AND HAVE FOLLOWED THAT. DEPENDING ON THE WIND
DIRECTION...WHICH IS TRENDING A LITTLE SSW...SO TRENDED TEMPS UP
THERE SLIGHTLY DUE TO DOWNSLOPE WINDS.
ONE FINAL THING OF NOTE IS THE NAM IS SHOWING DECENT
INSTABILITY...2K J/KG OF CAPE...IN THE AFTN WITH THE STRONG DIURNAL
HEATING OVER THE W HALF. OPTED TO REMAIN DRY EVEN WITH THIS
INSTABILITY POTENTIAL...BUT WILL NEED TO MONITOR.
WEAK UPPER LEVEL DISTURBANCE SATURDAY NIGHT AND SUNDAY LOOKS TO STAY
S OF THE CWA. COULD SEE SOME SHOWERS DEVELOPING WITH THIS WEEK
DISTURBANCE OVER CNTRL LK MI AND LOWER MI. MAIN FEATURE OF NOTE TO
AFFECT THE CWA IS A DECAYING COLD FRONT DROPPING OVER LK SUPERIOR
SAT NIGHT. WILL PUSH N ON SUNDAY AS A WARM FRONT AS LOW PRESSURE
ORGANIZES OVER THE NRN PLAINS. QUESTION IS HOW FAR S IT WILL SINK
BEFORE PUSHING BACK N. GFS/ECMWF/GEM STALL IT OVER LK SUPERIOR AND
MAYBE REACHING THE KEWEENAW PENINSULA. NAM TRIES TO PUSH IT A TOUCH
FARTHER S AND DEVELOP PCPN OVER MUCH OF UPPER MI. FINDING IT HARD TO
BUCK THE MODEL CONSENSUS...ESPECIALLY THAT FAR OUT ON THE NAM...SO
WILL CONFINE THE CHANCE POPS OVER LK SUPERIOR AND LK MI AND KEEP
SLIGHTS IN BETWEEN.
EXTENDED /SUNDAY NIGHT THROUGH WEDNESDAY/...
ANOMALOUS H500 HEIGHTS...AROUND 2-3 STD DEV ABOVE NORMAL FOR
MID-LATE MARCH WILL REMAIN OVER THE AREA FOR THE EXTENDED PERIOD.
TROUGH OVER AMPLIFYING AND MOVING OVER THE SW CONUS WILL AMPLIFY THE
RIDGE UPSTREAM AND LEAD TO CONTINUED WARMING UNDER SRLY FLOW KEEPING
WARM AIR IN PLACE.
WITH THE SRLY FLOW...MODELS CONTINUE TO SURGE WARM/MOIST AIR OVER
THE AREA. THIS MAKES FOR A TROUBLING FORECAST...AS IT IS LARGELY
DEPENDENT ON IF LOW CLOUDS DEVELOP BELOW THE PERSISTANT H850
INVERSION. IF THE LAST 12HRS ARE ANY INDICATION...PRODUCES SOME
DOUBT TO NORTHWARD EXTENT. BUT THE PERSISTANT SRLY FLOW WILL LIKELY
PUSH THE MOISTURE INTO THE AREA AND SHOULD LEAD TO MORE
CLOUDY/FOGGY NIGHTS WHICH WILL BREAK UP DUE TO DIURNAL HEATING.
ADDED FOG OVER LK SUPERIOR/MICHIGAN THROUGH THE EXTENDED AND BLED
IT INLAND NEAR LK MI DURING THE OVERNIGHT HOURS WITH THE SSE WINDS.
TEMPS WILL GREATLY DEPEND ON LOW CLOUDS/FOG AND DAYTIME MIXING...BUT
WILL CONTINUE TO BE WELL ABOVE NORMAL WITH MANY DAYS IN THE 60S
OVER THE WEST. COOLER VALUES OVER THE E AND ALSO PORTIONS OF THE
NCNTRL...DUE TO SSE WINDS THROUGH MUCH OF THE PERIOD.
AS FOR PCPN...MODELS CONTINUING TO SHOW LIGHT QPF ALONG AND OVER
THE GREAT LKS. WHAT IS LIKELY HAPPENING IS THAT THE ABUNDANT
MOISTURE IS TOO MUCH IN THE LOW LEVELS AND THE MODELS ARE TRYING TO
RELIEVE THEMSELVES OF THIS EXCESS MOISTURE. WILL LIKELY BE FOG IN
THESE AREAS DUE TO THE MOIST AIR OVER THE COOL GREAT LKS...BUT
DON/T SEE MUCH CHANCES FOR SHOWERS WITH THE STRONG H850 CAP. IF
ANYTHING...A FOG/DZ COMBINATION WOULD OCCUR. THUS...HAVE REMOVED
MUCH OF THE SLIGHT CHANCES FROM SUN NIGHT ON.
MODELS SHOWING THE UPPER RIDGE STARTING TO SHIFT E AS THE UPPER
TROUGH STARTS TO BECOME CUT OFF ON WED. HOW THIS LOW EVOLVES WILL
AFFECT THE FORECAST FOR THE END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 731 AM EDT THU MAR 15 2012
ALTHOUGH SOME HI CLDS WL FILTER THRU THE UPR GRT LKS...EXPECT VFR
CONDITIONS THIS FORECAST PERIOD WITH DRY HI PRES DOMINATING. WINDS
WL BE GENERALLY LGT BUT WITH A STEADIER LK BREEZE DURING THIS
AFTN... ESPECIALLY AT SAW AND CMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 AM EDT THU MAR 15 2012
EXPECT WINDS TO BE MOSTLY UNDER 20 KTS THROUGH THIS WEEKEND AS A
RELATIVELY WEAK PRES GRADIENT DOMINATES. ALTHOUGH A SHARPER PRES
GRADIENT/STRONGER S FLOW WILL DEVELOP OVER THE WEEKEND...THE
UNSEASONABLY WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN
PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE LAKE...HELPING TO
KEEP SURFACE WINDS ON THE LIGHTER SIDE. AT SOME POINT...FOG MAY
BECOME AN ISSUE...ESPECIALLY IF SOME RAINFALL OCCURS OVER THE LAKE.
RIGHT NOW...IT APPEARS DRY WEATHER SHOULD GENERALLY DOMINATE...
KEEPING FOG POTENTIAL LIMITED.
&&
.HYDROLOGY...
ISSUED AT 405 AM EDT THU MAR 15 2012
WELL ABOVE NORMAL TEMPERATURES OVER THE LAST SEVERAL DAYS...
ESPECIALLY ON WED...ALONG WITH RAIN OF 0.10 TO MORE THAN 0.5 INCH ON
MON HAS LED TO INCREASED SNOWMELT/RUNOFF. THIS RUNOFF HAS PRODUCED
SOME RISE IN LEVELS OF RIVERS IN UPR MI OVER THE LAST COUPLE OF DAYS.
ABOVE NORMAL TEMPERATURES INTO NEXT WEEK WILL CONTINUE TO MELT THE
SNOW PACK AND LEAD TO FURTHER INCREASES IN RIVER AND STREAM LEVELS.
ALTHOUGH A COOLER/DRIER AIRMASS WILL ARRIVE TODAY AND SLOW THE
MELTING...EXPECT SOME OF THE RIVERS ACROSS THE AREA TO EXCEED THEIR
BANKS BY THE END OF THIS WEEK. FORTUNATELY...THE LACK OF ANY
SIGNIFICANT RAIN IN THE FORECAST FOR THE NEXT WEEK WILL LOWER THE
CHANCE OF SIGNIFICANT FLOODING. BUT PERSONS LIVING NEAR RIVERS AND
STREAMS SHOULD MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF
WALKING ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
DID HAVE AN APPARENT ICE JAM ON THE ONTONAGON RIVER NEAR ROCKLAND
MON EVENING. THIS CAUSED THE RIVER LEVELS TO RISE 4FT BEFORE IT
BROKE FREE. WILL NEED TO MONITOR CONDITIONS ALONG THE ONTONAGON
RIVER OVER THE NEXT DAY OR TWO...AS THE NUMEROUS BENDS COULD CAUSE
THE ICE TO FORM ANOTHER JAM. IN ADDITION...ICE WAS REPORTED ON THE
FORD RIVER AT HYDE AND THE MOUTH AT LK MI. DEPENDING ON THE BREAKUP
OF THE ICE...THERE IS A POTENTIAL FOR MORE ICE JAMS INTO THIS
WEEKEND...WHEN THE RIVER ICE MAY CLEAR COMPLETELY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...KC
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
554 AM CDT THU MAR 15 2012
.AVIATION...12Z KGRI TAF. A LOW STRATUS DECK IS QUICKLY EXPANDING
ACROSS KANSAS AND WILL SLIDE INTO FAR SOUTHERN NEBRASKA EARLY THIS
MORNING. FORECAST MODEL GUIDANCE KEEPS THESE LOW CEILINGS TO THE
SOUTH OF KGRI...BUT IT WILL BE A CLOSE CALL. A SCATTERED LOW DECK
AT KGRI IS CERTAINLY POSSIBLE BY MID MORNING AND EVEN MVFR OR IFR
CEILINGS CAN NOT BE RULED OUT. HOWEVER...IT IS SLIGHTLY MORE
LIKELY THAT THE LOW CEILINGS WILL STAY SOUTH OF KGRI AND
THEREFORE...WILL BE KEEPING THE VFR CEILINGS IN THE TAF FOR NOW.
ANY LOW STRATUS CLOUDS SHOULD BURN OFF BY EARLY AFTERNOON MAKING
FOR A MOSTLY SUNNY AFTERNOON. LOW STRATUS CLOUDS WILL AGAIN FORM
NEAR KGRI TONIGHT. WILL JUST CALL FOR A SCATTERED DECK FOR
NOW...BUT IFR CEILINGS ARE AT LEAST SOMEWHAT POSSIBLE AGAIN
TONIGHT. THE WIND WILL BE LIGHT AND VARIABLE THROUGHOUT THE
PERIOD.
&&
.PREV DISCUSSION... /ISSUED 526 AM CDT THU MAR 15 2012/
SHORT TERM...THROUGH SATURDAY NIGHT. PRIMARY FORECAST CONCERNS
ARE STRATUS AND FOG TRENDS...TEMPERATURES...AND WHETHER ANY
THUNDERSTORM CHANCES ARE NECESSARY DURING THE NEXT 72 HOURS. IN
SHORT...LEFT FORECAST FAIRLY SIMILAR TO PREVIOUS ONE...WITH NO
OFFICIAL PRECIPITATION MENTION AND A CONTINUATION OF MUCH-ABOVE
NORMAL TEMPERATURES.
09Z OBJECTIVE SURFACE ANALYSIS AND AUTOMATED OBS REVEAL A WEAK
SURFACE PRESSURE GRADIENT ACROSS THE CWA...WITH MOST PLACES
REPORTING VARIABLE TO LIGHT EASTERLY BREEZES. HOWEVER...A SHARP
TEMPERATURE/DEWPOINT GRADIENT IS VERY EVIDENT ALONG AN AXIS FROM
SOUTHWEST KANSAS TO FAR SOUTHEAST NEBRASKA...JUST BARELY SKIRTING
THE EDGES OF THE CWA AT THIS HOUR. THIS DIVIDING LINE IS ESSENTIALLY
A WEAK WARM FRONT...EXTENDING NORTHEAST FROM A WEAK LOW IN
SOUTHWEST KANSAS. FOR EXAMPLE...DEWPOINTS RANGE FROM ONLY 39 AT
HEBRON TO 59 AT CONCORDIA...ONLY TWO COUNTIES APART. AS HAS BEEN
THE CASE FOR SEVERAL NIGHTS NOW...TEMPS ACROSS MUCH OF THE CWA
HAVE SNUCK BELOW PREVIOUSLY FORECAST LOWS...WITH MOST PLACES IN
THE 40S...BUT TYPICAL COLD SITES SUCH AS ORD ALL THE WAY INTO THE
LOW 30S. TURNING TO 11-3.9 MICRON SATELLITE IMAGERY...A SWATH OF
LOW STRATUS HAS BEEN BLOSSOMING ACROSS NORTHERN KS INTO SOUTHEAST
NEB OVER THE PAST FEW HOURS...AS GENERALLY CAPTURED BY THE 900MB
RH FIELDS FROM THE 06Z NAM. DESPITE OBJECTIVE RUC ANALYSIS
INDICATING THAT AT LEAST 1000 J/KG MUCAPE HAS LIFTED INTO THE
SOUTHERN CWA...LACK OF FORCING AND CAPPING HAS PRECLUDED ANY
SHOWER/THUNDERSTORM DEVELOPMENT IN OR NEAR THE CWA. WATER VAPOR
IMAGERY AND SHORT TERM MODEL DATA INDICATES A PERSISTENT WEST-
SOUTHWEST FLOW ALOFT...WITH NO MAJOR SHORTWAVES IN THE FLOW EXCEPT
FOR ONE WELL OFF TO THE NORTHWEST ENTERING BRITISH COLUMBIA.
STARTING OFF WITH THE VERY SHORT TERM...MAIN CHALLENGE IS EXTENT
OF STRATUS DEVELOPMENT THIS MORNING...AND WHETHER ANY IMPACTFUL
FOG WILL JOIN THE FRAY AS WELL. FOLLOWED NAM 950-900MB RH FIELDS
FAIRLY CLOSELY FOR SKY COVER THIS MORNING...WITH STRATUS RAPIDLY
EXPANDING NORTHEAST AND ENCOMPASSING MUCH OF THE SOUTHEAST 1/3 TO
1/2 OF THE CWA BY SUNRISE. AS FOR FOG...PREVIOUS FORECAST ALREADY
HAD PATCHY WORDING...AND ACTUALLY EXPANDED THIS TO COVER A BIT
LARGER AREA...AS HRRR HAS INSISTED ON REDUCED VISIBILITIES ACROSS
MUCH OF THE SAME AREAS AS THE EXPANDING STRATUS. JUST WITHIN PAST
HOUR...BELOIT HAS NOW DROPPED TO 1/2 MILE VSBY. OBVIOUSLY TEMP
TRENDS TODAY WILL BE HIGHLY DEPENDENT ON STRATUS TRENDS...WITH NAM
SOUNDING INDICATING THAT SOUTHEAST AREAS COULD POTENTIALLY HOLD
ONTO STRATUS THROUGH AT LEAST MUCH OF THE MORNING HOURS BEFORE
MIXING OUT COMMENCES. CERTAINLY CONFIDENCE IS LOW IN THE HOURLY
TRENDS...BUT PER MET/MAV GUIDANCE CONSENSUS...NUDGED DOWN HIGHS A
FEW DEGREES FROM PREVIOUS FORECAST MOST AREAS...WITH NEARLY THE
ENTIRE CWA IN A FAIRLY UNIFORM 76-79 RANGE. AS FOR CONVECTIVE
CHANCES...MODELS HAVE BACKED OFF YET AGAIN ON SUGGESTION FROM 24
HOURS AGO OF POSSIBLE CONVECTION THIS AFTERNOON/EVENING IN THE
EASTERN CWA...AND DESPITE PRESENCE OF 1000-2000 J/KG MLCAPE
BUILDING INTO EASTERN AREAS THIS AFTERNOON...LACK OF FORCING AND A
DECENT CAPPING INVERSION SHOULD KEEP STORMS AT BAY AND THUS LEFT
DRY. A POTENTIALLY BETTER RISK FOR ISOLATED/SCATTERED CONVECTION
WILL RESIDE A FEW COUNTIES EAST OF THE CWA WITHIN NORTHEAST KS AND
FAR SOUTHEAST NEB PER THE 00Z 4KM WRF-NMM. BREEZES TODAY WILL
REMAIN FAIRLY LIGHT WITH A BROAD SURFACE TROUGH AXIS DRAPED
THROUGH FROM NORTH-SOUTH...SEPARATING A NORTHERLY COMPONENT IN THE
WEST FROM A SOUTHERLY ONE IN THE WEST. WHILE DEWPOINTS ACROSS MUCH
OF THE SOUTHEAST 2/3 OF THE CWA WILL BE ON THE INCREASE
TODAY...THE WEST WILL LIKELY REMAIN RATHER DRY AND THUS CARRY AN
ELEVATED FIRE THREAT TO SOME EXTENT. SEE FIRE WEATHER DISCUSSION
BELOW.
TONIGHT...KEPT IT DRY WITH FORCING REMAINING NEGLIGIBLE. WITH
BREEZES REMAINING LIGHT OVERNIGHT...AND PLENTY OF LOW LEVEL
MOISTURE AROUND...INTRODUCED ANOTHER ROUND OF PATCHY FOG WORDING
MAINLY ACROSS THE SOUTHEAST 2/3 OF THE CWA. WITH VARIOUS
MODELS/GUIDANCE SUCH AS MET/MAV AND ALSO SREF VISIBILITY
PROBABILITIES PICKING UP ON A FOG SIGNAL...WOULD NOT BE SURPRISED
TO SEE AT LEAST A FEW HOURS OF LOCALLY DENSE DEVELOPMENT...BUT
WILL START WITH GENERIC PATCHY FOR NOW. LEFT LOW TEMPS TONIGHT
SIMILAR TO PREVIOUS FORECAST RANGING FROM LOW 40S FAR WEST TO LOW
50S EAST...BUT WOULD NOT BE SURPRISED TO SEE A FEW WESTERN AREAS
AGAIN SETTLE INTO THE 30S IF THE AIR REMAINS DRY ENOUGH.
FRIDAY...THE FIRST POTENTIAL ISSUE WILL THE EXTENT OF ANY MORNING
STRATUS/FOG...ALTHOUGH A SLOWLY STRENGTHENING HIGH PLAINS LEE
TROUGH WILL INDUCE A BIT STRONGER SOUTHERLY BREEZE...WHICH SHOULD
HELP TO MIX OUT ANY FOG BY MID TO LATE MORNING IF IT DOES IN FACT
MATERIALIZE. INSTABILITY WILL AGAIN CLIMB ACROSS EASTERN ZONES
DURING THE AFTERNOON...BUT FORECAST SOUNDINGS AND PLAN VIEW PROGS
SHOW A HEALTHY CAP TO NEAR-SURFACE BASED CONVECTION AND THUS LEFT
OUT MENTION OF STORMS DURING THE DAY AND ALSO INTO THE
NIGHT...ALTHOUGH THE NIGHT PERIOD WILL NEED WATCHED AS LOW LEVEL
JET RAMPS UP. IN FACT...06Z NAM HINTS AT POSSIBLE ISOLATED STORM
DEVELOPMENT JUST EAST OF THE CWA AT SOME POINT FRIDAY NIGHT...BUT
CONFIDENCE IS LOW GIVEN RECENT TRENDS OF CONVECTIVE SIGNALS NOT
PANNING OUT. CHANGED FRIDAY HIGH TEMPS LITTLE FROM BEFORE...WITH
NEAR 80 IN NEB ZONES AND LOW-MID 80S IN KS.
SATURDAY/SATURDAY NIGHT...THE FLOW ALOFT STARTS TURNING MORE
SOUTH-SOUTHWESTERLY IN RESPONSE TO A DEEP...HIGH AMPLITUDE TROUGH
FINALLY COMING ONSHORE ACROSS THE WESTERN CONUS. ALTHOUGH FORECAST
SOUNDINGS CONTINUE TO SHOW AIRMASS CAPPED TO CONVECTIVE
POTENTIAL...THERE ARE HINTS IN MODELS SUCH AS THE ECMWF/GFS THAT
STRATUS AND POSSIBLE DRIZZLE COULD AFFECT EASTERN ZONES DURING
THIS TIME FRAME. LEFT DRY FOR NOW HOWEVER. THE MAIN STORY SATURDAY
WILL BE INCREASING SOUTHERLY BREEZES...WITH SUSTAINED SPEEDS
LIKELY INTO THE 20-25 MPH RANGE ACROSS MUCH OF THE CWA WITH HIGHER
GUSTS. AS FOR TEMPS...SURE ENOUGH...ANOTHER DAY OF UPPER
70S-LOW 80S LOOKS IN STORE.
IN CLOSING...ALTHOUGH RISK OF CONVECTION IS CERTAINLY NOT NIL
ACROSS THE CWA DURING THE NEXT FEW DAYS...DEGREE OF CAPPING AND
LACK OF FORCING PRECLUDES FORMAL MENTION OF EVEN SLIGHT CHANCES
FOR NOW...WITH LOCATIONS GENERALLY 100-200 MILES EAST-SOUTHEAST OF
THE CWA MORE FAVORED FOR AT LEAST LIMITED STORM COVERAGE DURING
THIS TIME FRAME.
LONG TERM...SUNDAY THROUGH WEDNESDAY. THIS WILL CONTINUE TO BE AN
UNSEASONABLY WARM PERIOD. IN ADDITION...THUNDERSTORMS WILL ALSO BE
POSSIBLE AS A VERY DEEP UPPER LEVEL TROUGH DIGS ACROSS THE WESTERN
CONUS.
THIS PATTERN WILL ALLOW MOISTURE RICH AIR TO FLOW NORTH THROUGH THE
PLAINS IN ADVANCE OF THE DEEPENING WESTERN CONUS TROUGH. THE
COMBINATION OF RICH SFC MOISTURE AND STRONG UPPER LEVEL WINDS AND
SHEAR WILL LIKELY RESULT IN SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE GREAT PLAINS.
THE MOST LIKELY TIME FRAME FOR STRONG TO SEVERE THUNDERSTORMS OVER
CENTRAL NEBRASKA AND CENTRAL KANSAS WILL BE MONDAY AND TUESDAY. A
FAIRLY STRONG CAP ON SUNDAY WILL BE DIFFICULT TO OVERCOME GIVEN THAT
THE BETTER FORCING ASSOCIATED WITH THE UPPER SYSTEM WILL STILL BE
WELL OFF TO THE WEST ON SUNDAY. THE SYSTEM SHOULD THEN EITHER BE
EAST OF OUR CWA OR BECOME A CUT OFF LOW TO OUR SOUTH BY
WEDNESDAY...NEITHER OF THESE SCENARIOS WOULD BE VERY FAVORABLE FOR
THUNDERSTORMS. CONSEQUENTLY...IT APPEARS THAT MONDAY AND TUESDAY
WILL BE THE MOST FAVORABLE DAYS FOR THUNDERSTORMS INCLUDING THE
POTENTIAL FOR SOME SEVERE THUNDERSTORMS DEPENDING ON HOW FAR
EAST/WEST THE DRY LINE SETS UP. THE LATEST MODEL RUNS CONTINUE TO
SEEM TO BE TOO FAST WITH THIS SYSTEM. THE 00Z GFS AND ECMWF ARE BOTH
FASTER/FURTHER EAST WITH THE UPPER TROUGH THAN THE 00Z ENSEMBLE
MEAN. IN ADDITION...THIS KIND OF PATTERN WITH A LARGE BLOCKING RIDGE
ACROSS THE EASTERN CONUS WILL TYPICALLY SLOW SYSTEM PROGRESSION DOWN
MORE THAN THE FORECAST MODELS ACCOUNT FOR. THEREFORE...EXPECT A
POTENTIALLY STORMY START TO NEXT WEEK...ESPECIALLY IN THE MONDAY
AND/OR TUESDAY TIME FRAME.
FIRE WEATHER...ALTHOUGH WIND SPEEDS TODAY SHOULD FALL WELL SHORT
OF OFFICIAL RED FLAG WARNING CRITERIA OF 20 MPH SUSTAINED/25 MPH
GUST...LATEST 06Z NAM SUGGESTS THAT DEWPOINTS ACROSS GENERALLY THE
NORTHWEST 1/3 OF THE CWA WILL CHECK IN A BIT LOWER THAN PREVIOUSLY
EXPECTED...AND QUITE A BIT LOWER THAN VALUES ACROSS THE SOUTHEAST
1/2 OF THE CWA WHERE DEWPOINTS SHOULD STEADILY INCREASE. THE NET
RESULT IS AFTERNOON RELATIVE HUMIDITY VALUES TUMBLING TO AROUND 20
PERCENT ACROSS A HANDFUL OF FAR WESTERN/NORTHWEST COUNTIES THIS
AFTERNOON...WHILE MUCH HIGHER RH VALUES 40-50 PERCENT RESIDE
ACROSS MUCH OF THE EASTERN CWA. DESPITE THE FAIRLY LIGHT WINDS...THE
GRASSLAND FIRE DANGER STATEMENT...RFDGID...CALCULATED EXTREME FIRE
DANGER CATEGORY FOR DAWSON AND GOSPER COUNTIES FOR THIS
AFTERNOON...WITH SEVERAL BORDERING COUNTIES IN THE VERY HIGH
CATEGORY. LOOKING AHEAD A FEW DAYS...INCREASED DEWPOINTS AND THUS
RH VALUES SHOULD INVADE EVEN WESTERN COUNTIES ON FRIDAY AND
SATURDAY...THUS KEEPING RH ABOVE 20 PERCENT. HOWEVER...AN
EFFECTIVE NORTH-SOUTH DRYLINE WILL SET UP JUST WEST OF THE
CWA...MEANING THAT WESTERN COUNTIES COULD LIE VERY CLOSE TO A
SHARP MOISTURE GRADIENT ON THOSE DAYS AND FLIRT WITH DROPPING
BELOW 20 PERCENT RH. GIVEN THAT SOUTH WINDS WILL ALSO BE ON THE
INCREASE...WILL NEED TO CLOSELY WATCH WESTERN FRINGE OF CWA FOR
FIRE WEATHER ISSUES...WHILE THE MAJORITY OF THE CWA SHOULD BE IN
BETTER SHAPE THAN LATELY WITH THE ARRIVAL OF HIGHER DAYTIME DEWPOINTS
IN THE 40S AND 50S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
526 AM CDT THU MAR 15 2012
.SHORT TERM...THROUGH SATURDAY NIGHT. PRIMARY FORECAST CONCERNS
ARE STRATUS AND FOG TRENDS...TEMPERATURES...AND WHETHER ANY
THUNDERSTORM CHANCES ARE NECESSARY DURING THE NEXT 72 HOURS. IN
SHORT...LEFT FORECAST FAIRLY SIMILAR TO PREVIOUS ONE...WITH NO
OFFICIAL PRECIPITATION MENTION AND A CONTINUATION OF MUCH-ABOVE
NORMAL TEMPERATURES.
09Z OBJECTIVE SURFACE ANALYSIS AND AUTOMATED OBS REVEAL A WEAK
SURFACE PRESSURE GRADIENT ACROSS THE CWA...WITH MOST PLACES
REPORTING VARIABLE TO LIGHT EASTERLY BREEZES. HOWEVER...A SHARP
TEMPERATURE/DEWPOINT GRADIENT IS VERY EVIDENT ALONG AN AXIS FROM
SOUTHWEST KANSAS TO FAR SOUTHEAST NEBRASKA...JUST BARELY SKIRTING
THE EDGES OF THE CWA AT THIS HOUR. THIS DIVIDING LINE IS ESSENTIALLY
A WEAK WARM FRONT...EXTENDING NORTHEAST FROM A WEAK LOW IN
SOUTHWEST KANSAS. FOR EXAMPLE...DEWPOINTS RANGE FROM ONLY 39 AT
HEBRON TO 59 AT CONCORDIA...ONLY TWO COUNTIES APART. AS HAS BEEN
THE CASE FOR SEVERAL NIGHTS NOW...TEMPS ACROSS MUCH OF THE CWA
HAVE SNUCK BELOW PREVIOUSLY FORECASTED LOWS...WITH MOST PLACES IN
THE 40S...BUT TYPICAL COLD SITES SUCH AS ORD ALL THE WAY INTO THE
LOW 30S. TURNING TO 11-3.9 MICRON SATELLITE IMAGERY...A SWATH OF
LOW STRATUS HAS BEEN BLOSSOMING ACROSS NORTHERN KS INTO SOUTHEAST
NEB OVER THE PAST FEW HOURS...AS GENERALLY CAPTURED BY THE 900MB
RH FIELDS FROM THE 06Z NAM. DESPITE OBJECTIVE RUC ANALYSIS
INDICATING THAT AT LEAST 1000 J/KG MUCAPE HAS LIFTED INTO THE
SOUTHERN CWA...LACK OF FORCING AND CAPPING HAS PRECLUDED ANY
SHOWER/THUNDERSTORM DEVELOPMENT IN OR NEAR THE CWA. WATER VAPOR
IMAGERY AND SHORT TERM MODEL DATA INDICATES A PERSISTENT WEST-
SOUTHWEST FLOW ALOFT...WITH NO MAJOR SHORTWAVES IN THE FLOW EXCEPT
FOR ONE WELL OFF TO THE NORTHWEST ENTERING BRITISH COLUMBIA.
STARTING OFF WITH THE VERY SHORT TERM...MAIN CHALLENGE IS EXTENT
OF STRATUS DEVELOPMENT THIS MORNING...AND WHETHER ANY IMPACTFUL
FOG WILL JOIN THE FRAY AS WELL. FOLLOWED NAM 950-900MB RH FIELDS
FAIRLY CLOSELY FOR SKY COVER THIS MORNING...WITH STRATUS RAPIDLY
EXPANDING NORTHEAST AND ENCOMPASSING MUCH OF THE SOUTHEAST 1/3 TO
1/2 OF THE CWA BY SUNRISE. AS FOR FOG...PREVIOUS FORECAST ALREADY
HAD PATCHY WORDING...AND ACTUALLY EXPANDED THIS TO COVER A BIT
LARGER AREA...AS HRRR HAS INSISTED ON REDUCED VISIBILITIES ACROSS
MUCH OF THE SAME AREAS AS THE EXPANDING STRATUS. JUST WITHIN PAST
HOUR...BELOIT HAS NOW DROPPED TO 1/2 MILE VSBY. OBVIOUSLY TEMP
TRENDS TODAY WILL BE HIGHLY DEPENDENT ON STRATUS TRENDS...WITH NAM
SOUNDING INDICATING THAT SOUTHEAST AREAS COULD POTENTIALLY HOLD
ONTO STRATUS THROUGH AT LEAST MUCH OF THE MORNING HOURS BEFORE
MIXING OUT COMMENCES. CERTAINLY CONFIDENCE IS LOW IN THE HOURLY
TRENDS...BUT PER MET/MAV GUIDANCE CONSENSUS...NUDGED DOWN HIGHS A
FEW DEGREES FROM PREVIOUS FORECAST MOST AREAS...WITH NEARLY THE
ENTIRE CWA IN A FAIRLY UNIFORM 76-79 RANGE. AS FOR CONVECTIVE
CHANCES...MODELS HAVE BACKED OFF YET AGAIN ON SUGGESTION FROM 24
HOURS AGO OF POSSIBLE CONVECTION THIS AFTERNOON/EVENING IN THE
EASTERN CWA...AND DESPITE PRESENCE OF 1000-2000 J/KG MLCAPE
BUILDING INTO EASTERN AREAS THIS AFTERNOON...LACK OF FORCING AND A
DECENT CAPPING INVERSION SHOULD KEEP STORMS AT BAY AND THUS LEFT
DRY. A POTENTIALLY BETTER RISK FOR ISOLATED/SCATTERED CONVECTION
WILL RESIDE A FEW COUNTIES EAST OF THE CWA WITHIN NORTHEAST KS AND
FAR SOUTHEAST NEB PER THE 00Z 4KM WRF-NMM. BREEZES TODAY WILL
REMAIN FAIRLY LIGHT WITH A BROAD SURFACE TROUGH AXIS DRAPED
THROUGH FROM NORTH-SOUTH...SEPARATING A NORTHERLY COMPONENT IN THE
WEST FROM A SOUTHERLY ONE IN THE WEST. WHILE DEWPOINTS ACROSS MUCH
OF THE SOUTHEAST 2/3 OF THE CWA WILL BE ON THE INCREASE
TODAY...THE WEST WILL LIKELY REMAIN RATHER DRY AND THUS CARRY AN
ELEVATED FIRE THREAT TO SOME EXTENT. SEE FIRE WEATHER DISCUSSION
BELOW.
TONIGHT...KEPT IT DRY WITH FORCING REMAINING NEGLIGIBLE. WITH
BREEZES REMAINING LIGHT OVERNIGHT...AND PLENTY OF LOW LEVEL
MOISTURE AROUND...INTRODUCED ANOTHER ROUND OF PATCHY FOG WORDING
MAINLY ACROSS THE SOUTHEAST 2/3 OF THE CWA. WITH VARIOUS
MODELS/GUIDANCE SUCH AS MET/MAV AND ALSO SREF VISIBILITY
PROBABILITIES PICKING UP ON A FOG SIGNAL...WOULD NOT BE SURPRISED
TO SEE AT LEAST A FEW HOURS OF LOCALLY DENSE DEVELOPMENT...BUT
WILL START WITH GENERIC PATCHY FOR NOW. LEFT LOW TEMPS TONIGHT
SIMILAR TO PREVIOUS FORECAST RANGING FROM LOW 40S FAR WEST TO LOW
50S EAST...BUT WOULD NOT BE SURPRISED TO SEE A FEW WESTERN AREAS
AGAIN SETTLE INTO THE 30S IF THE AIR REMAINS DRY ENOUGH.
FRIDAY...THE FIRST POTENTIAL ISSUE WILL THE EXTENT OF ANY MORNING
STRATUS/FOG...ALTHOUGH A SLOWLY STRENGTHENING HIGH PLAINS LEE
TROUGH WILL INDUCE A BIT STRONGER SOUTHERLY BREEZE...WHICH SHOULD
HELP TO MIX OUT ANY FOG BY MID TO LATE MORNING IF IT DOES IN FACT
MATERIALIZE. INSTABILITY WILL AGAIN CLIMB ACROSS EASTERN ZONES
DURING THE AFTERNOON...BUT FORECAST SOUNDINGS AND PLAN VIEW PROGS
SHOW A HEALTHY CAP TO NEAR-SURFACE BASED CONVECTION AND THUS LEFT
OUT MENTION OF STORMS DURING THE DAY AND ALSO INTO THE
NIGHT...ALTHOUGH THE NIGHT PERIOD WILL NEED WATCHED AS LOW LEVEL
JET RAMPS UP. IN FACT...06Z NAM HINTS AT POSSIBLE ISOLATED STORM
DEVELOPMENT JUST EAST OF THE CWA AT SOME POINT FRIDAY NIGHT...BUT
CONFIDENCE IS LOW GIVEN RECENT TRENDS OF CONVECTIVE SIGNALS NOT
PANNING OUT. CHANGED FRIDAY HIGH TEMPS LITTLE FROM BEFORE...WITH
NEAR 80 IN NEB ZONES AND LOW-MID 80S IN KS.
SATURDAY/SATURDAY NIGHT...THE FLOW ALOFT STARTS TURNING MORE
SOUTH-SOUTHWESTERLY IN RESPONSE TO A DEEP...HIGH AMPLITUDE TROUGH
FINALLY COMING ONSHORE ACROSS THE WESTERN CONUS. ALTHOUGH FORECAST
SOUNDINGS CONTINUE TO SHOW AIRMASS CAPPED TO CONVECTIVE
POTENTIAL...THERE ARE HINTS IN MODELS SUCH AS THE ECMWF/GFS THAT
STRATUS AND POSSIBLE DRIZZLE COULD AFFECT EASTERN ZONES DURING
THIS TIME FRAME. LEFT DRY FOR NOW HOWEVER. THE MAIN STORY SATURDAY
WILL BE INCREASING SOUTHERLY BREEZES...WITH SUSTAINED SPEEDS
LIKELY INTO THE 20-25 MPH RANGE ACROSS MUCH OF THE CWA WITH HIGHER
GUSTS. AS FOR TEMPS...SURE ENOUGH...ANOTHER DAY OF UPPER
70S-LOW 80S LOOKS IN STORE.
IN CLOSING...ALTHOUGH RISK OF CONVECTION IS CERTAINLY NOT NIL
ACROSS THE CWA DURING THE NEXT FEW DAYS...DEGREE OF CAPPING AND
LACK OF FORCING PRECLUDES FORMAL MENTION OF EVEN SLIGHT CHANCES
FOR NOW...WITH LOCATIONS GENERALLY 100-200 MILES EAST-SOUTHEAST OF
THE CWA MORE FAVORED FOR AT LEAST LIMITED STORM COVERAGE DURING
THIS TIME FRAME.
.LONG TERM...SUNDAY THROUGH WEDNESDAY. THIS WILL CONTINUE TO BE AN
UNSEASONABLY WARM PERIOD. IN ADDITION...THUNDERSTORMS WILL ALSO BE
POSSIBLE AS A VERY DEEP UPPER LEVEL TROUGH DIGS ACROSS THE WESTERN
CONUS.
THIS PATTERN WILL ALLOW MOISTURE RICH AIR TO FLOW NORTH THROUGH THE
PLAINS IN ADVANCE OF THE DEEPENING WESTERN CONUS TROUGH. THE
COMBINATION OF RICH SFC MOISTURE AND STRONG UPPER LEVEL WINDS AND
SHEAR WILL LIKELY RESULT IN SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE GREAT PLAINS.
THE MOST LIKELY TIME FRAME FOR STRONG TO SEVERE THUNDERSTORMS OVER
CENTRAL NEBRASKA AND CENTRAL KANSAS WILL BE MONDAY AND TUESDAY. A
FAIRLY STRONG CAP ON SUNDAY WILL BE DIFFICULT TO OVERCOME GIVEN THAT
THE BETTER FORCING ASSOCIATED WITH THE UPPER SYSTEM WILL STILL BE
WELL OFF TO THE WEST ON SUNDAY. THE SYSTEM SHOULD THEN EITHER BE
EAST OF OUR CWA OR BECOME A CUT OFF LOW TO OUR SOUTH BY
WEDNESDAY...NEITHER OF THESE SCENARIOS WOULD BE VERY FAVORABLE FOR
THUNDERSTORMS. CONSEQUENTLY...IT APPEARS THAT MONDAY AND TUESDAY
WILL BE THE MOST FAVORABLE DAYS FOR THUNDERSTORMS INCLUDING THE
POTENTIAL FOR SOME SEVERE THUNDERSTORMS DEPENDING ON HOW FAR
EAST/WEST THE DRY LINE SETS UP. THE LATEST MODEL RUNS CONTINUE TO
SEEM TO BE TOO FAST WITH THIS SYSTEM. THE 00Z GFS AND ECMWF ARE BOTH
FASTER/FURTHER EAST WITH THE UPPER TROUGH THAN THE 00Z ENSEMBLE
MEAN. IN ADDITION...THIS KIND OF PATTERN WITH A LARGE BLOCKING RIDGE
ACROSS THE EASTERN CONUS WILL TYPICALLY SLOW SYSTEM PROGRESSION DOWN
MORE THAN THE FORECAST MODELS ACCOUNT FOR. THEREFORE...EXPECT A
POTENTIALLY STORMY START TO NEXT WEEK...ESPECIALLY IN THE MONDAY
AND/OR TUESDAY TIME FRAME.
&&
.FIRE WEATHER...ALTHOUGH WIND SPEEDS TODAY SHOULD FALL WELL SHORT
OF OFFICIAL RED FLAG WARNING CRITERIA OF 20 MPH SUSTAINED/25 MPH
GUST...LATEST 06Z NAM SUGGESTS THAT DEWPOINTS ACROSS GENERALLY THE
NORTHWEST 1/3 OF THE CWA WILL CHECK IN A BIT LOWER THAN PREVIOUSLY
EXPECTED...AND QUITE A BIT LOWER THAN VALUES ACROSS THE SOUTHEAST
1/2 OF THE CWA WHERE DEWPOINTS SHOULD STEADILY INCREASE. THE NET
RESULT IS AFTERNOON RELATIVE HUMIDITY VALUES TUMBLING TO AROUND 20
PERCENT ACROSS A HANDFUL OF FAR WESTERN/NORTHWEST COUNTIES THIS
AFTERNOON...WHILE MUCH HIGHER RH VALUES 40-50 PERCENT RESIDE
ACROSS MUCH OF THE EASTERN CWA. DESPITE THE FAIRLY LIGHT WINDS...THE
GRASSLAND FIRE DANGER STATEMENT...RFDGID...CALCULATED EXTREME FIRE
DANGER CATEGORY FOR DAWSON AND GOSPER COUNTIES FOR THIS
AFTERNOON...WITH SEVERAL BORDERING COUNTIES IN THE VERY HIGH
CATEGORY. LOOKING AHEAD A FEW DAYS...INCREASED DEWPOINTS AND THUS
RH VALUES SHOULD INVADE EVEN WESTERN COUNTIES ON FRIDAY AND
SATURDAY...THUS KEEPING RH ABOVE 20 PERCENT. HOWEVER...AN
EFFECTIVE NORTH-SOUTH DRYLINE WILL SET UP JUST WEST OF THE
CWA...MEANING THAT WESTERN COUNTIES COULD LIE VERY CLOSE TO A
SHARP MOISTURE GRADIENT ON THOSE DAYS AND FLIRT WITH DROPPING
BELOW 20 PERCENT RH. GIVEN THAT SOUTH WINDS WILL ALSO BE ON THE
INCREASE...WILL NEED TO CLOSELY WATCH WESTERN FRINGE OF CWA FOR
FIRE WEATHER ISSUES...WHILE THE MAJORITY OF THE CWA SHOULD BE IN
BETTER SHAPE THAN LATELY WITH THE ARRIVAL OF HIGHER DAYTIME DEWPOINTS
IN THE 40S AND 50S.
&&
.PREV DISCUSSION... /ISSUED 1244 AM CDT THU MAR 15 2012/
AVIATION...06Z KGRI TAF. A LOW STRATUS DECK IS SLIDING NORTH
THROUGH KANSAS EARLY THIS MORNING. THE BIG FORECAST CHALLENGE WILL
BE DETERMINING HOW FAR NORTH THESE CLOUDS WILL MAKE IT AS THE
NORTHERN EXTENT OF THE CLOUDS COULD BE VERY CLOSE TO KGRI. FOR
NOW...WILL CONTINUE TO KEEP THE LOW STRATUS DECK SOUTH OF THE KGRI
AREA ALLOWING FOR A CONTINUATION OF THE VFR CONDITIONS. THE WIND
WILL BE VERY LIGHT AND VARIABLE THROUGHOUT THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...PFANNKUCH
LONG TERM...WESELY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
918 AM EDT THU MAR 15 2012
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL SLIDE EAST ACROSS LAKE ERIE
TODAY. WEAK HIGH PRESSURE WILL BUILD SOUTHEAST OUT OF CANADA LATE
FRIDAY...THEN TO THE EAST COAST ON SATURDAY. A WEAK AREA OF LOW
PRESSURE WILL BRING ANOTHER SURGE OF MOISTURE TO THE AREA AGAIN
LATE SATURDAY INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BOTH HRRR AND RUC SHOW CURRENT WIDESPREAD CONVECTION SETTLING DOWN
INTO THE MIDDAY HOURS THEN STARTING TO REDEVELOP DURING THE MID TO
LATE AFTERNOON HOURS FOR MOSTLY THE WEST HALF OF THE AREA. THE
REDEVELOPMENT MAKES SENSE BASED ON WHERE MORE SUNSHINE IS EXPECTED
BUT NOT ENTIRELY SOLD ON THE FACT THAT ALL THE CURRENT CONVECTION
COMPLETELY GOES AWAY. WILL OPT TO LEAVE AT LEAST A SMALL CHANCE
GOING FOR ALL AREAS DURING MIDDAY THEN RAMP THE POPS BACK UP FOR
THE NEW ACTIVITY. LITTLE CHANGE TO HIGH TEMP FORECAST BUT WILL
ADJUST AND BLEND FOR CURRENT AND IMMINENT CONDITIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
SIMILAR AIRMASS IN PLACE TONIGHT WITH LINGERING THETA-E RIDGE
OVERHEAD. DIFFERENCE IS LESS IN THE WAY OF A LOW LEVEL JET AND WEAK
RIDGING BUILDING OVERHEAD. WILL THEREFORE EXPECT LESS THUNDERSTORM
ACTIVITY DESPITE LINGERING ELEVATED INSTABILITY IN PLACE.
WEAK HIGH PRESSURE WILL PUSH SOUTH OUT OF CANADA ON FRIDAY WITH
ANOTHER RETURN SURGE OF MOISTURE BY LATE SATURDAY INTO SUNDAY AS THE
RIDGE BUILDS TO THE EAST COAST. TEMPERATURES REMAIN WELL ABOVE
NORMAL THROUGH THE SHORT TERM IN THE UPPER 60S AND LOW TO EVEN MID
70S AT TIMES.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
IMPRESSIVE UPPER LEVEL RIDGE WILL RESIDE OVER THE EASTERN HALF OF
THE UNITED STATES THROUGH THE EXTENDED. THERE MAY END UP BEING
ENOUGH LOW LEVEL MOISTURE TO ALLOW FOR SOME AFTERNOON AND EVENING
THUNDERSTORMS. BEST CHANCES LOOK TO BE OVER THE HILLS AND ALONG ANY
LAKE BREEZE BOUNDARY THAT DEVELOPS.
TEMPERATURES WILL BE WELL ABOVE AVERAGE...LIKELY 25 TO 30 DEGREES
ABOVE AVERAGE. LOW TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE
NORMAL HIGHS FOR THIS TIME OF YEAR.
&&
.AVIATION /13Z THURSDAY THROUGH MONDAY/...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DECREASE IN
COVERAGE AND INTENSITY AS THEY DRIFT SLOWLY TO THE EAST. HAVE
STARTED SEVERAL TAF SITES ACROSS THE CENTRAL AND EAST WITH SOME
VICINITY SHOWERS AND THUNDERSTORMS. ANY MVFR OR BRIEF IFR WILL
OCCUR WITH THE THUNDERSTORMS. AWAY FROM THIS MORNINGS THUNDERSTORMS
EXPECT TO SEE A CONTINUATION OF VFR CONDITIONS. MOST LOCATIONS WILL
SEE SOME AFTERNOON CUMULUS. ADDITIONAL THUNDERSTORMS WILL DEVELOP
BY MID TO LATE AFTERNOON AND CONTINUE INTO THE EVENING. PLENTY OF
UNCERTAINTY ABOUT WHERE ANY BOUNDARIES FROM THIS MORNING
CONVECTION WILL BE BY AFTERNOON. THIS OUTFLOW BOUNDARY AND A
DISSIPATING FRONTAL BOUNDARY THAT WILL SAG TO NEAR LAKE ERIE
OVERNIGHT WILL BECOME THE FOCUS FOR AFTERNOON AND EVENING
THUNDERSTORMS.
OUTLOOK...NON VFR CONDITIONS POSSIBLE FRIDAY NIGHT THROUGH SUNDAY
IN ISOLATED TO SCATTERED THUNDERSTORMS.
&&
.MARINE...
A WEAK DISTURBANCE OVER LAKE SUPERIOR WILL DEVELOP ON THU AND MOVE N
OF LAKE ERIE ON FRI. SW FLOW AHEAD OF THE LOW WILL INCREASE BUT
REMAIN BELOW 20KT LATE THU AND INTO FRI. A WEAK BACKDOOR COLD FRONT
COULD SLIP JUST SOUTH OF THE LAKE FRI NT AND SATURDAY. THIS WEAK
SYSTEM WASHES OUT EARLY AS THE UPPER RIDGE RE-ESTABLISHES ITSELF
OVER THE REGION INTO NEXT WEEK. THE RIDGE WILL KEEP A PREDOMINANT SW
FLOW WITH PERIODS OF S/SE. NO HEADLINES EXPECTED THROUGH THE
FORECAST PERIOD AT THIS TIME.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...ADAMS/KEC
SHORT TERM...KEC
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...MULLEN
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
635 AM CDT THU MAR 15 2012
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE.
.SHORT TERM...TODAY THROUGH FRIDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE COLD
FRONT STRETCHING FROM LA CROSSE TO DOOR COUNTY EARLY THIS MORNING
AND SLOWLY SLIDING TO THE SOUTHEAST. WIDELY SCATTERED CONVECTION
FINALLY DEVELOPED ALONG THE FRONT ACROSS SOUTHEAST WISCONSIN AND
NORTHERN ILLINOIS...AND A FEW CELLS MAY GRAZE SHEBOYGAN COUNTY.
FARTHER NORTH...4-6KFT CLOUDS HAVE BEEN EXPANDING OVER NORTHEAST
WISCONSIN AND LAKE MICHIGAN WHILE PATCHY DENSE FOG HAS DEVELOPED
OVER CENTRAL WISCONSIN. AS NORTH TO NORTHEAST WINDS DEVELOP BEHIND
THE FRONT EARLY THIS MORNING...ANTICIPATING THE FOG TO DISSIPATE WITH
MOST OF IT GONE BY THE MORNING COMMUTE. WITH THE FRONT SETTLING TO
THE SOUTH TODAY...MAIN FORECAST CONCERNS REVOLVE AROUND SKY
CONDITIONS...FOG POTENTIAL...AND TEMPS.
TODAY...SURFACE COLD FRONT WILL SETTLE ACROSS THE SOUTHERN GREAT
LAKES TODAY WHILE HIGH PRESSURE MOVES ACROSS LAKE SUPERIOR. 850MB
FRONT WILL LAG TO THE NORTH OVER NORTHERN WISCONSIN...WHICH WILL
KEEP AMPLE MOISTURE IN THE 925-850MB LAYER. BEHIND THE
FRONT...SURFACE WINDS WILL TURN NE TO EASTERLY WHICH WILL ADVECT A
SHALLOW MARINE AIRMASS OVER MUCH OF NE WISCONSIN AND PARTIALLY INTO
CENTRAL WISCONSIN. PROGGED SOUNDINGS THIS MORNING ARE FOLDED
OVER...WITH THE RESIDUAL WARM AIRMASS LAYING OVER TOP THE RELATIVELY
COLDER MARINE AIRMASS...SUGGESTING A LAYER OF STRATUS OR FOG COULD
POSSIBLY FORM. THINK THIS PROCESS IS UNDER WAY OVER NORTHERN LAKE
MICHIGAN AS INDICATED BY THE GROWING DARK BLOB ON THE SATELLITE.
WILL INCREASE SKY COVER OVER MUCH OF NE AND E-C WISCONSIN...AND SOME
OVER CENTRAL WISCONSIN TOO FOR THIS MORNING. THINK THIS WILL EVOLVE
INTO A CU DECK WITH HEATING FOR THE AFTERNOON WITH PARTIAL CLEARING
ANTICIPATED. OVER N-C WISCONSIN...A VERY DRY AIRMASS WILL PUSH IN
FROM LAKE SUPERIOR...WITH DEWPOINTS TANKING ONCE AGAIN...WHICH WILL
SET UP A FAIRLY TIGHT DEWPOINT GRADIENT ACROSS THE FORECAST AREA.
CLOUDS AND AN EAST WIND WILL COOL TEMPS DOWN TODAY...AND WILL RANGE
FROM THE UPPER 50S NORTH TO UPPER 60S SOUTH...LOCALLY COOLER NEAR
LAKE MICHIGAN AND THE BAY OF GREEN BAY.
TONIGHT...VERY LITTLE CHANGES INTO TONIGHT. LIGHT RETURN FLOW WILL
BOW THE FRONT NORTHWARD INTO THE NORTHERN MISSISSIPPI VALLEY...WHILE
WE WILL STILL SEE LIGHT EAST FLOW NORTH OF THE BOUNDARY OVER
NORTHERN WISCONSIN. PROGGED SOUNDINGS INDICATE A SIMILAR INVERSION
DEVELOPING TONIGHT WITH A SHALLOW COOL AIRMASS IN PLACE. EVENING
HIGH CLOUDS WILL DEPART BY EARLY IN THE OVERNIGHT PERIOD...WHICH
WILL SUPPORT COOLING IN THE LOW LEVELS AND THE POSSIBILITY OF
STRATUS/FOG REFORMING. WILL INCREASE SKY COVER OVER NORTHEAST
WISCONSIN AND KEEP A MENTION OF PATCHY FOG IN THE FORECAST. LOWS
RANGING FROM THE MID 30S NORTH TO MID 40S SOUTH.
FRIDAY...THE FRONT WILL CONTINUE TO LIFT SLOWLY NORTHWARD ON
FRIDAY...POSSIBLY REACHING INTO CENTRAL WISCONSIN BY LATE IN THE
AFTERNOON. WITHOUT A GOOD PUSH ALOFT THOUGH...SOUTHEAST WINDS AT
THE SURFACE WILL KEEP THE SHALLOW MARINE AIR IN PLACE OVER THE REST
OF THE FORECAST AREA. MOISTURE IN THE 850-750MB LAYER WILL TRY TO
ROTATE INTO CENTRAL WISCONSIN AND THE NAM CREATES SOME ELEVATED CAPE
UP TO AROUND 700 J/KG IN THE AFTERNOON. IF THIS PANS OUT...NOT
SEEING A STRONG ENOUGH TRIGGER TO INITIATE CONVECTION...SO WILL
STICK WITH A DRY FORECAST. HIGHS RANGING FROM THE LOW 50S EAST TO
THE LOWER 70S WEST.
.LONG TERM...FRIDAY NIGHT THRU WEDNESDAY. MAIN FORECAST CONCERNS
ARE DEALING WITH CLOUD/FOG POTENTIAL...TEMPS...AND PRECIP CHANCES.
SUMMER-LIKE PATTERN TO CONTINUE INTO EARLY NEXT WEEK AS UPPER
RIDGE BUILDS ACROSS THE EASTERN CONUS...KEEPING TEMPS WELL ABOVE
NORMAL. AMAZING STRETCH OF LOW/MID 70S ARE EXPECTED SATURDAY
THROUGH TUESDAY...WITH RECORD HIGHS LIKELY. ONLY LOCATIONS NOT
PARTICIPATING IN THE VERY WARM AIR MASS WILL BE NEAR LAKE
MICHIGAN...WHERE TEMPS WILL STRUGGLE TO GET TO 60.
PRECIP CHANCES FAIRLY LOW AS WEAK DISTURBANCES STILL FORECAST TO
RIDE THE BACK SIDE OF THE EASTERN U.S. RIDGE. STILL TOUGH TO TIME
OUT THESE SMALL/WEAK DISTURBANCES THIS FAR IN ADVANCE. SO
CONFIDENCE REMAINS LOW ON THE TIMING/LOCATION OF THESE AND IF
THEY WILL BE ABLE TO GENERATE ANY SHOWER/STORM ACTIVITY. BEST
DISTURBANCE STILL LOOKS TO CROSS INTO THE GREAT LAKES SOMEWHERE
AROUND THE SATURDAY NIGHT TIME FRAME. MODELS HAVE DRIFTED A LITTLE
EAST WITH THIS FEATURE...KEEPING THE MAJORITY OF PRECIP IN LOWER
MICHIGAN. DUE TO THE TIMING/LOCATION CONCERNS...AND LACK OF UPPER
LEVEL SUPPORT...WILL KEEP SLIGHT CHANCE POPS FROM FRIDAY NIGHT
INTO SATURDAY NIGHT TO COVER SMALL THREAT OF SOME PRECIP ACTIVITY.
BY SUNDAY...THE UPPER RIDGE BUILDS OVER THE AREA TO KEEP PRECIP
CHANCES TO THE WEST...CLOSER TO THE DEEP UPPER TROUGH CROSSING
INTO THE PLAINS. THIS SYSTEM WILL BRING A DECENT CHANCE OF
SHOWERS/STORMS TO THE AREA MID-WEEK. STILL SOME DISAGREEMENT WITH
HOW THE MODELS HANDLE THE TROUGH AS IT CUTS OFF IN THE MID-
MISSISSIPPI VALLEY. STILL PLENTY OF TIME TO WORK ON THE DETAILS
WITH THIS SYSTEM...BUT CHANCES FOR WIDESPREAD INCREASE BY
WEDNESDAY.
LAKE MICHIGAN SHOULD SLOWLY LOSE ITS INFLUENCE ON ALL BUT THE
IMMEDIATE LAKESHORE BY SATURDAY AS WINDS TURN MORE SOUTHERLY
BEHIND THE WARM FRONT PUSHING NORTH OF THE AREA. FOG COULD LINGER
ON/NEAR LAKE MICHIGAN THROUGH THE WEEKEND...HOWEVER WILL JUST
CARRY THE MENTION FOR FRIDAY NIGHT AND SATURDAY NIGHT FOR NOW.
&&
.AVIATION...EARLY MORNING FOG WILL MOSTLY DISSIPATE AT THE TAF SITES
BY THE 12Z ISSUANCE AS A LIGHT NORTH TO NORTHEAST WIND DEVELOPS.
OTHERWISE...SCT TO BKN 4000-6000 FT WILL PREVAIL ACROSS THE REGION
FOR MUCH OF THE DAY. WINDS TURN LIGHT AGAIN TONIGHT WHICH COULD
LEAD TO MORE FOG FORMATION. CONFIDENCE IS LOW AGAIN...THOUGH
MARGINALLY BETTER CHANCES LOOK TO OCCUR OVER EASTERN WISCONSIN.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
101 PM CDT THU MAR 15 2012
.AVIATION...15/18Z TAF CYCLE
LOW CLOUDS ONCE AGAIN NOTED ACRS THE FA ATTM...WITH SOME LINGERING
MVFR CIGS NOTED OVR SERN AR. VFR CONDS ARE EXPECTED TO PREVAIL
THRU MUCH OF THE FCST PD. MOST OF THE LATEST SHORT TERM MODEL DATA
INDC LIMITED CHCS OF ORGANIZED CONVECTION OVR THE AREA THIS AFTN
AND TNGT. THUS...CONTD WITH A MENTION OF VCTS FOR THE TIME BEING.
LOW CLOUDS ARE FCST TO REFORM LATER TNGT OVR MUCH OF THE AREA...
RESULTING IN OCNL MVFR CONDS INTO FRI MRNG. /44/
&&
.PREV DISCUSSION... /ISSUED 1040 AM CDT THU MAR 15 2012/
UPDATE...
HAVE TRIMMED BACK PRECIP CHANCES THROUGH 1PM. REGIONAL RADAR
TRENDS ALONG WITH RAPID UPDATE RUC GUIDANCE SUGGESTS VERY LITTLE
CHANCE OF PRECIP IN THE SOUTHERN HALF OF THE STATE THROUGH MIDDAY.
HAVE FOLLOWED THIS TREND AND REMOVED MENTION OF PRECIP FOR AREAS
SOUTH OF A LINE FROM RUSSELLVILLE TO JUST NORTH OF SEARCY AND UP
THROUGH ROUGHLY NEWPORT IN THE EAST. NORTH OF THAT LINE...HAVE
ISOLATED TO SCATTERED SHOWER/THUNDERSTORMS MENTIONED THROUGH 1PM.
MADE ONLY SOME SLIGHT ADJUSTMENTS TO THE AFTERNOON/EVENING
POPS...WITH HIGHEST POPS STILL IN THE NORTH AND EAST.
PREV DISCUSSION... /ISSUED 248 AM CDT THU MAR 15 2012/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
THE NEAR TERM WILL FEATURE A LARGE STORM SYSTEM DIGGING IN THE
SOUTHWEST UNITED STATES...AND A RIDGE BUILDING IN THE SOUTHEAST.
ARKANSAS WILL BE BETWEEN THESE FEATURES...WITH A PERSISTENT
SOUTHWEST WIND FLOW ALOFT...WELL ABOVE NORMAL TEMPERATURES...AND
ENOUGH MOISTURE TO FUEL ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS.
THERE WILL NOT BE MUCH TO TRIGGER PRECIPITATION OTHER THAN AFTERNOON
HEATING. PIECES OF ENERGY WILL PERIODICALLY RIDE THE FLOW INTO
THE REGION...AND THIS WILL LEAD TO MORE ORGANIZED CONVECTION. SUCH
WILL BE THE CASE TODAY...ESPECIALLY IN NORTHERN/CENTRAL ARKANSAS.
IN FACT...A SEVERE STORM OR TWO MAY POP UP. ANOTHER MORE ORGANIZED
EVENT MIGHT UNFOLD FRIDAY NIGHT/SATURDAY MORNING IN THE
NORTH/WEST.
NOT LOOKING FOR WIDESPREAD HEAVY RAIN THROUGH THE WEEKEND. IN
FACT...JUST AS WITH A SUMMERTIME PATTERN...SOME SPOTS MAY NOT GET
ANY RAIN AT ALL GIVEN HIT AND MISS PRECIPITATION.
LONG TERM...MONDAY THROUGH WEDNESDAY
AMPLIFIED PATTERN WILL CONTINUE THROUGH THE EXTENDED...WITH VERY
LITTLE CHANGE TO THE GOING FORECAST. DIURNAL CONVECTION WILL
CONTINUE FOR MONDAY...BEFORE LARGE UPPER LOW OVER THE DESERT
SOUTHWEST WILL SLOWLY MOVE EAST FOR THE MIDDLE OF THE WEEK. HAVE
GONE WITH THE SLOWER EUROPEAN GUIDANCE...WITH RAIN CHANCES
CONTINUING THROUGH THE END OF THE LONG TERM. WITH SOUTHWEST FLOW
PREVAILING...ABOVE NORMAL TEMPERATURES WILL CONTINUE.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
315 PM EDT THU MAR 15 2012
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER NORTHERN NEW ENGLAND AND THE CANADIAN
MARITIMES WILL GRADUALLY WEAKEN AND SHIFT EASTWARD THROUGH FRIDAY.
A WEAKENING COLD FRONT WILL CROSS OUR AREA LATE FRIDAY, WITH HIGH
PRESSURE BUILDING IN DURING SATURDAY. THIS AREA OF HIGH PRESSURE
THEN BECOMES ANCHORED ALONG AND EAST OF THE MID ATLANTIC COAST
SUNDAY THROUGH THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
WE HAVE TO LOOK BOTH WAYS BEFORE CROSSING THE METEOROLOGICAL STREET
TODAY AS AT LEAST FOR ONE DAY MARCH ACTED MORE LIKE MARCH AND NOT
MAY. WITH REGARDS TO THE LOW CLOUDINESS, WE FOLLOWED THE HRRR AND
RUC13 FORECAST LOW LEVEL MOISTURE THAT WAS VERIFYING THE BEST TO
SPREAD AND DEVELOP THE LOW CLOUDS WESTWARD AS THE REST OF THE
AFTERNOON AND EVENING PROGRESSES. GIVEN THE SUBTLE SHIFT IN THE
ONSHORE FLOW, THIS WOULD FAVOR A FASTER EXPANSION IN THE NORTHERN
TWO THIRDS OF OUR CWA. UPWIND LAND OBSERVATIONS ARE SHOWING MORE
STRATUS THAN FOG AND FOR NOW WE DID NOT INCLUDE ANY FOG IN THE
GRIDS. UPWIND DEW POINTS ARE LOWER THAN WATER TEMPS, BUT NOT AS SURE
ABOUT THIS BEING THE CASE OVERNIGHT.
AS FOR PCPN CHANCES TONIGHT, COULD NOT FIND A MODEL THAT WAS
HANDLING THE ONGOING CONVECTION WELL, EVEN OUR HIGH RES VERSIONS. SO
WE TRIED TO INFER THE THOUGHT PROCESS OF TSRAS DEVELOPING IN THE
MORE UNSTABLE AIR TO OUR WEST OR NORTHWEST AND MAKING THEIR WAY INTO
OUR CWA OVERNIGHT. THERE WERE MORE SHORT WAVES NORTH THAN SOUTH
FORECAST, SO HIGHEST POPS WERE GENERALLY NORTH OF I195 IN NEW JERSEY
AND NORTHWEST OF I95 ELSEWHERE. AS FOR THUNDER POSSIBILITIES, WHILE
IT IS FORECAST UNSTABLE ENOUGH FOR THEM ALOFT, DO NOT SEE ANY STRONG
SHORT WAVES OR VIGOROUS FCST ISENTROPIC LIFT TO WARRANT A MENTION
BEYOND ISOLATED. WHILE WE ARE NOT CARRYING IT TO SIMPLIFY THE
WORDING A BIT FOR TONIGHT, THE POSSIBILITY OF DRIZZLE OCCURRING IN
ADDITION TO OTHER PTYPES IS STILL THERE.
GIVEN THAT TEMPERATURES OVERALL ARE OFF TO A MUCH COOLER START THAN
EITHER WE OR STAT GUIDANCE ANTICIPATED EARLIER TODAY, MIN TEMPS WERE
AT OR BELOW STAT GUIDANCE FOR TNGT. A BLEND OF ACTUAL WRF-NMMB,
ECMWF SFC PROG TEMPS AND LATEST MET AND MAV GUIDANCE WAS USED. WE
TRIED TO KEEP MINS AT OR ABOVE CURRENT DEW POINTS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
ON FRIDAY THE LOW LEVEL ONSHORE FLOW IS FORECAST TO CEASE WITH A
MORE GENERAL SOUTHWEST FLOW FORECAST TO OCCUR ABOVE THE BOUNDARY
LAYER. AT THE SURFACE THIS IS COMPLICATED BY A WEAK LOW PRESSURE
SYSTEM THAT IS FORECAST TO FORM ON THE WARM FRONT SOUTH OF OUR CWA
AND AT THE LEAST WOULD SLOW THE OCCURRENCE OF SOUTHWEST WINDS AT THE
SURFACE. IN ADDITION, IT IS QUITE UNSTABLE AROUND THE GREAT LAKES
AND WOULD EXPECT MORE CONVECTION AND THUS DEBRIS FOR US TO MOVE INTO
OUR CWA. THIS ALL POINTS TO POSSIBLE PROBLEMS AT ERODING THE LOW
CLOUDS AS FRIDAY CONTINUES. THE ECMWF AND WRF-NMMB WHICH DID VERY
WELL WITH THE PREVIOUS COOL AIR DAMMING EVENT IS WARMING PA AND MD
BY THE AFTERNOON. WE ARE BANKING ON THIS ONE TO GET MAX TEMPS CLOSE
TO WHAT WE ARE CARRYING (ALTHO STILL UNDER STAT GUIDANCE) AND TWO TO
INITIATE SOME CLOSER TO HOME GROWN CONVECTION DURING THE AFTERNOON.
WE DID CARRY LIKELY POPS BANKING ON THIS AND ALSO THE PRESENCE OF
SOME WEAK FCST MID LVL QVEC CONVERGENCE AND CWA BEING IN THE
ENTRANCE REGION OF A DEVELOPING H2.5 JET. THERE ARE A TRAINLOAD OF
ASSUMPTIONS BEING MADE ABOUT FRIDAY AND THUS THE PARTICULARS AND
OVERALL OUTCOME SHOULD BE VIEWED WITH LESSER CONFIDENCE THAN AVERAGE
FOR A SECOND PERIOD FORECAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
THE SYNOPTIC SETUP STARTS OUT WITH A WEAKENING SHORT WAVE TROUGH
MOVING ACROSS THE AREA FRIDAY NIGHT, WITH AN ASSOCIATED COLD FRONT
EXPECTED TO SETTLE SOUTH AND EAST OF THE AREA. ADDITIONAL
TROUGHING THEN TAKES PLACE IN THE WESTERN U.S. THIS WILL FORCE
DOWNSTREAM RIDGING, WHICH LOOKS TO HOLD FOR MOST OF THIS TIME FRAME.
THE SURFACE HIGH INITIALLY WILL BE SLIDING ACROSS NEW ENGLAND AND
DOWN TO THE MID ATLANTIC, AND THIS MAY ALLOW FOR SOME ADDITIONAL
COOLING TO START. A SEPARATE FRONTAL BOUNDARY DRAPED WELL TO OUR
NORTH LATE SUNDAY THROUGH WEDNESDAY SHOULD REMAIN THERE GIVEN THE
SOUTHWESTERLY FLOW AND RIDGING. THE OVERALL RIDGE THEN STRENGTHENS
IN THE EAST AS AN AMPLIFYING LARGE UPPER-LEVEL TROUGH SLOWLY EJECTS
INTO THE PLAINS. GIVEN THAT THE UPPER-LEVEL JET IS CURRENTLY DIGGING
OVER THE PACIFIC AND HOW QUICKLY THE UPPER TROUGH DEVELOPS, A CUTOFF
LOW SHOULD RESULT. THE MODEL GUIDANCE IS OFTEN TO FAST IN EJECTING
UPPER-LEVEL LOWS. GIVEN THIS TENDENCY ALONG WITH THE MAJORITY OF THE
ENSEMBLE MEMBERS SUPPORTING THE SLOWER EJECTION, HPC FAVORED A
TRANSITION TO EITHER THE GEFS MEAN OR THE ECMWF ENSEMBLE MEAN FROM
TUESDAY ONWARD TO ACCOUNT FOR THE SLOWER SOLUTION. THE INCREASING
SOUTHWESTERLY FLOW WILL ALLOW WAA TO STRENGTHEN WITH TIME, HOWEVER
WE MAY HAVE TO EVENTUALLY DEAL WITH SOME SUBTLE SHORT WAVES ON THE
WESTERN PERIPHERY OF THE RIDGE, ALTHOUGH SOME OF THESE FEATURES LOOK
TO BE CONVECTIVELY INDUCED/ENHANCED.
FOR FRIDAY NIGHT AND SATURDAY, A WEAKENING SHORT WAVE TROUGH SLIDES
THROUGH WITH AN ACCOMPANY COLD FRONT. AS A PLUME OF MOISTURE AND
SOME WEAK INSTABILITY ACCOMPANIES THESE FEATURES, A COUPLE OF
SHOWERS AND A THUNDERSTORM SHOULD BE AROUND FRIDAY EVENING BEFORE
WEAKENING AND SLIDING TO OUR SOUTH AND EAST. THE BOUNDARY LOOKS TO
SETTLE FAR ENOUGH TO OUR SOUTH AS HIGH PRESSURE BUILDS ACROSS NEW
ENGLAND INTO SATURDAY. THE ACTUAL BOUNDARY MAY THEN DISSIPATE AS
UPPER-LEVEL RIDGING BUILDS IN. THE LOW-LEVEL FLOW LOOKS LIGHT ENOUGH
ON SATURDAY WITH HIGH PRESSURE SLIDING DOWN THE COAST, THEREFORE AN
ONSHORE FLOW SHOULD DEVELOP ALLOWING FOR COOLER TEMPERATURES
ESPECIALLY ALONG THE COAST. THIS MAY ALSO TRY AND DEVELOP SOME LOW
CLOUDS FOR A TIME BEFORE THE SURFACE HIGH SLIDES FAR ENOUGH
SOUTHWARD TO SHIFT THE WINDS FROM THE SOUTH.
FOR SUNDAY AND MONDAY, THE OVERALL RIDGE IS FORECAST TO STRENGTHEN
IN THE EAST AS A STRONG UPPER-LEVEL TROUGH AMPLIFIES ACROSS THE
WEST. THIS WESTERN TROUGH WILL AIDE IN STRENGTHENING SOUTHWESTERLY
FLOW AND ALSO WAA FROM THE GULF COAST ALL THE WAY INTO THE
NORTHEAST. WHATEVER IS LEFT OF THE BOUNDARY TO OUR SOUTH SHOULD LIFT
NORTHWARD AS A WARM FRONT. THERE APPEARS TO BE SOME WEAK SHORT WAVES
TRAVERSING THE WESTERN FLANK OF THE RIDGE INTO THE OHIO VALLEY AND
INTO PARTS OF THE NORTHEAST. IF WE CAN GET ENOUGH INSTABILITY
REALIZED ALONG WITH HIGHER LOW-LEVEL MOISTURE, SOME CONVECTION MAY
ACCOMPANY THESE FEATURES. GIVEN THE FORECAST POSITION OF THE RIDGE,
THE FLOW MAY END UP BEING LIGHT ENOUGH TO FOCUS ANY CONVECTION TO
OUR WEST ALONG THE HIGHER TERRAIN. IN ADDITION, A SEA BREEZE MAY
DEVELOP BOTH AFTERNOONS.
FOR TUESDAY AND WEDNESDAY, THE TROUGH IN THE WEST EJECTS OUT ACROSS
THE PLAINS. THIS FEATURE IS FORECAST TO BECOME RATHER ROBUST AND
CLOSE OFF WITH A DEEP SOUTHERLY FLOW AHEAD OF. GIVEN THE STRENGTH OF
THIS TROUGH, STRONGER RIDGING THEN IS MAINTAINED DOWNSTREAM AND OVER
THE EAST. AGAIN THERE MAY BE TERRAIN OR SUBTLE SHORT WAVE INDUCED
CONVECTION MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS TO
OUR WEST. IF THE TIGHTER PRESSURE GRADIENT REMAINS FAR ENOUGH TO OUR
WEST, THEN PLENTY OF WARMING WOULD PROBABLY FAVOR SEA BREEZE
DEVELOPMENT EACH AFTERNOON. A FRONTAL BOUNDARY DRAPED WELL TO OUR
NORTH SHOULD REMAIN THERE GIVEN THE SOUTHERLY FLOW AND RIDGING OVER
OUR AREA.
FOR THURSDAY, A CLOSED LOW ACROSS THE PLAINS LOOKS TO SLOWLY SLIDE
EASTWARD GIVEN A LARGE RIDGE DOWNSTREAM. WE MAY HAVE TO WATCH A
FRONTAL BOUNDARY WELL TO OUR NORTH AS SOME GUIDANCE SHOWS HIGH
PRESSURE TRYING TO BUILD INTO NEW ENGLAND. THERE COULD BE ENOUGH OF
A WEAKNESS IN THE FLOW TO ALLOW A LOW-LEVEL BOUNDARY TO SLIP
SOUTHWARD AT SOME POINT. FOR NOW THOUGH, WE FAVORED THE RIDGE
/SURFACE AND ALOFT/ TO HOLD ENOUGH AND KEEP THIS LOW-LEVEL BOUNDARY
TO OUR NORTH.
AFTER FRIDAY EVENING, WE KEPT POPS UNDER SLIGHT CHC GIVEN INCREASING
UNCERTAINTY WITH ANY SUBTLE SHORT WAVES ON THE WEST SIDE OF THE
RIDGE. AS FOR TEMPERATURES, WE GENERALLY WENT WITH A MOS BLEND
FRIDAY NIGHT THROUGH SUNDAY THEN HPC GUIDANCE FROM SUNDAY NIGHT
ONWARD. SOME ADJUSTMENTS WERE MADE MAINLY CLOSER TO THE COAST DUE TO
SOME SEA BREEZE/ONSHORE POTENTIAL.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE FORECAST REMAINS A LOW CONFIDENCE ONE.
THE LOW CLOUDS EROSION PROCESS TOWARD THE COAST HAS SLOWED.
THERE WILL COME A POINT LATER THIS AFTERNOON GIVING THE CONTINUED
OCEANIC TRAJECTORY THAT THIS WILL REVERSE AND A LOW MVFR TO IFR CIG
WILL SPREAD ACROSS ALL THE TERMINALS. UNTIL THEN WE MAINTAINED SOME
MVFR TO IFR CIGS DURING THE AFTERNOON AT THE LOCAL KPHL AIRPORTS AND
KACY AND KMIV. ANY SMALLER AIRPORTS NORTHEAST OF A KACY TO KTTN LINE
SHOULD REMAIN IFR. WINDS WILL BE FROM EAST AND AVERAGE AROUND 10 KTS.
WIDESPREAD IFR CONDITIONS MAINLY DUE TO CIGS ARE FORECAST FOR
TONIGHT. THERE WILL BE SOME SHOWERS AROUND AND CAN NOT RULE OUT
DRIZZLE WITH THE ONSHORE FLOW. CONFIDENCE IS NOT HIGH ENOUGH TO
INCLUDE THE MENTION OF SHOWERS IN ANY FORECAST GROUP AT THIS TIME.
THE HIGHER RESOLUTION MODELS ARE SUGGESTING IF SHOWERS WERE TO
OCCUR AT ANY TERMINAL, IT WOULD BE FOR JUST AN HOUR OR TWO. IN
ADDITION THERE IS EVEN A LOWER PROBABILITY OF THUNDER AFFECTING
ANY TERMINALS. WINDS SHOULD BE LIGHTER FROM THE NORTHEAST TO EAST.
THE IMPROVEMENT ABOVE IFR IS EXPECTED TO BE SLOW DURING THE
MORNING ON FRIDAY AND WE BRING MOST TERMINALS UP TO MVFR LATE IN THE
MORNING. WE DID INCLUDE THE CHANCE OF THUNDER IN THE KPHL TAF FOR
FRIDAY AFTERNOON AROUND THE TIME OF MAXIMUM FORECAST INSTABILITY.
OUTLOOK...
FRIDAY NIGHT AND SATURDAY...SOME AREAS OF SUB-VFR FRIDAY NIGHT AS A
WEAK SYSTEM MOVES THROUGH WITH A COUPLE OF SHOWERS OR A
THUNDERSTORM. SOME SUB-VFR CONDITIONS MAY LINGER EARLY SATURDAY
MORNING. THERE COULD BE SOME POCKETS OF LOWER CLOUDS LATER SATURDAY
FOR A TIME, BUT CONFIDENCE IS LOW.
SUNDAY THROUGH TUESDAY...OVERALL VFR WITH A SOUTHERLY WIND. THERE
COULD BE SOME AFTERNOON AND EVENING SEA/BAY BREEZES DEVELOPING. ANY
SHOWERS OR THUNDERSTORMS SHOULD BE CONFINED TO OUR WEST AND MOSTLY
TERRAIN INDUCED, BUT THESE SHOULD BE TIED TO WEAK ENERGY MOVING
AROUND THE WEST SIDE OF HIGH PRESSURE. THERE IS LOW CONFIDENCE
REGARDING ANY SUB-VFR CONDITIONS IN THE EVENT THE MOISTURE INCREASES
ENOUGH TO RESULT IN POCKETS OF LOW CLOUDS/FOG THROUGH TIME.
&&
.MARINE...
IT LOOKS AS THOUGH WE HAVE WEATHERED THE THREAT FOR SMALL CRAFT
ADVISORY CONDITIONS FOR SEAS AND WINDS WITH THE ONSHORE FLOW TODAY.
THIS FLOW IS FORECAST TO WEAKEN AS WE GO THROUGH THE NIGHT. WINDS
SHOULD BECOME LIGHTER AND MORE VARIABLE ON FRIDAY PRECEDING THE
APPROACHING FRONT AND SEAS ARE NOT EXPECTED TO STAY BELOW SMALL
CRAFT ADVISORY CRITERIA ALSO.
OUTLOOK...
A WEAKENING SYSTEM WILL MOVE THROUGH FRIDAY NIGHT WITH ANY SHOWERS
ENDING. HIGH PRESSURE BUILDS DOWN FROM NEW ENGLAND SATURDAY WITH
PERHAPS A LITTLE SURGE IN ONSHORE WINDS, BUT THE GRADIENT LOOKS WEAK
ENOUGH TO KEEP WINDS BELOW 25 KNOTS. THIS SURFACE HIGH THEN
ESTABLISHES ITSELF ALONG AND JUST EAST OF THE MID ATLANTIC COAST
SUNDAY THROUGH TUESDAY WITH A SOUTHERLY WIND DEVELOPING. OVERALL,
THE WIND FIELD IS FORECAST TO BE ON THE LIGHTER SIDE WITH
SUB-ADVISORY CONDITIONS OCCURRING. THE LOCAL NEARSHORE WINDS MAY
BECOME ENHANCED SOME AT TIMES DUE TO ANY SEA/BAY BREEZE CIRCULATIONS
THAT DEVELOP.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...GIGI
SHORT TERM...GIGI
LONG TERM...GORSE
AVIATION...GIGI/GORSE
MARINE...GIGI/GORSE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
520 PM CDT THU MAR 15 2012
.DISCUSSION...UPDATE FOR LATE AFTERNOON INTO MID EVENING...
519 PM CDT
THUNDERSTORMS CONTINUE TO DEVELOP IN THE AXIS OF MAX SB CAPE...MU
CAPE AND LOWERS SHOWALTER INDEX VALUES FROM E CENTRAL IL ENE TO
NW IN. STRONGEST CORES HAVE THE POTENTIAL FOR PRODUCING SUB-SEVERE
HAIL INTO EARLY THIS EVE TIL HEATING FALLS OF AS SUN CONTINUES TO
LOWER TOWARD THE HORIZON.
TRS
&&
.PREV DISCUSSION...
301 PM CDT
MAIN CONCERNS FOR THE REMAINDER OF THE AFTERNOON WILL FOCUS ON THE
BACK DOOR COLD FRONT PUSHING DOWN TO THE SRN TIP OF LAKE MICHIGAN
AND INLAND NERN/NCNTRL IL...AS WELL AS PCPN AND TS CHANCES IN THE
WARM...MOIST AIR OVER THE REMAINDER OF THE AREA. THE FRONT HAS
ALREADY PUSHED INTO ERN LAKE COUNTY...IL AND CONTINUES TO PUSH
SOUTH. THE FOG/ST BEHIND THE FRONT HAS THINNED PER LATEST VIS
IMAGERY...BUT EXPECT THAT THERE SHOULD BE AT LEAST PATCHY FOG INLAND
AND THERE IS STILL THE POTENTIAL FOR AREAS OF DENSE FOG ALONG THE
LAKE FRONT AS THE LAKE COOLED AIR PUSHES INLAND THIS EVENING.
HOWEVER...GIVEN THE LACK OF DEVELOPMENT AT THE CURRENT TIME...WILL
DEFER ANY DENSE FOG HEADLINES TO THE EVENING OR MID SHIFTS. AS FOR
TS POTENTIAL...THE LATEST VIS IMAGERY SHOWS WIDESPREAD CU
DEVELOPMENT WITH DECENT VERTICAL GROWTH OVER PORTIONS OF THE AREA
SOUTH OF I-80...WITH LESSER DEVELOPED STRATOCU TO THE NORTH. FEEL
THAT THERE IS STILL A CHANCE FOR SOME ISOLD TS DEVELOPMENT AS FAR
NORTH AS THE I-80 OR I-88 CORRIDOR AS THE BETTER INSTABILITY SPREADS
NORTHWARD TO THE COLD FRONT. THE TS CHANCES WILL CONTINUE THROUGH
THE NIGHT OVER ALL BUT THE FAR NRN AND NERN PORTIONS OF THE CWA
GIVEN THE WARM...MOIST AIRMASS...BUT GIVEN THE LACK OF A FOCUSING
ELEMENT...ANY ACTIVITY SHOULD BE ISOLD. TEMPERATURES HAVE ALSO BEEN
AN ISSUE TODAY AS WITH TEMPS RISING INTO THE UPPER 70S TO LOWER
80S. LOCATIONS SOUTH OF THE FRONT STILL HAVE THE POTENTIAL TO WARM
A BIT MORE BEFORE SUNSET AND ROCKFORD AND OHARE HAVE ALREADY BROKEN
RECORDS FOR TODAY.
TEMPERATURES WILL REMAIN THE BIG NEWS FOR THE NEXT SEVERAL DAYS.
HAVE ACTUALLY MADE LITTLE CHANGE TO THE GOING FORECAST AS FAR AS
MAXT AND MINT ARE CONCERNED. WITH THE UPPER RIDGE REMAINING PARKED
OVER THE REGION AND PERSISTENT SLY-SWLY FLOW DRAWING WARM...MOIST
AIR NWD...RECORD OR NEAR RECORD HIGH TEMPS ARE LIKELY THROUGH EARLY
NEXT WEEK. ALSO...GIVEN LITTLE CHANGE IN THE LARGE SCALE
AIRMASS...THERE WILL ALSO BE PERIODIC CHANCES FOR SHRA/TSRA THROUGH
THE ENTIRE FORECAST PERIOD. HOWEVER...THERE WILL NO SIGNIFICANT
FOCUSING MECHANISM THROUGH THE PERIOD...SO HAVE CONTAINED POPS TO
CHANCE/SLIGHT CHANCE LEVELS.
THERE ARE SOME INDICATIONS THAT THE RECORD WARMTH MAY MODERATE BY
THE END OF THE PERIOD AS THE MEDIUM RANGE FORECAST GUIDANCE SHOWS A
CUT-OFF LOW KICKING OUT OF THE SRN ROCKIES AND MOVING OUT OVER THE
SOUTH HIGH PLAINS...THOUGH THERE SHOULD STILL BE UPPER RIDGING
POKING BACK FROM THE SERN CONUS TO THE UPPER MISSISSIPPI VALLEY.
EVEN THOUGH THE GFS AND ECMWF ARE IN UNUSUALLY GOOD AGREEMENT FOR
SUCH A FEATURE AT THAT TIME RANGE...HAVE LOW CONFIDENCE IN THE
TIMING OF THIS SCENARIO AS CUT OFF LOWS ARE NOTORIOUSLY SLOWER IN
LIFTING OUT THAN THE GUIDANCE WOULD SUGGEST.
KREIN
&&
.CLIMATE...
540 AM CDT
RECORD MAXIMUM TEMPERATURES FOR CHICAGO
MAR 15 74 1995
MAR 16 78 1945
MAR 17 74 2009
RECORD MAXIMUM TEMPERATURES FOR ROCKFORD
MAR 15 73 1995
MAR 16 75 1945
MAR 17 74 2003
NORMAL NUMBER OF 70 DEGREE DAYS IN MARCH FOR BOTH CHICAGO AND
ROCKFORD IS 1.2.
RECORD NUMBER OF DAYS WITH MAX TEMP 70 OR ABOVE IN MARCH
CHICAGO 9 IN 1945...6 IN 1910 AND 1907.
ROCKFORD 11 IN 1910...7 IN 1945.
RECORD FOR CONSECUTIVE 70 DEGREE DAYS IN MARCH
CHICAGO...5 FROM MARCH 12-16 1995.
ROCKFORD...9 MARCH 23-31 1910.
TEMPERATURES IN THE 80S ARE EXTREMELY RARE IN MARCH. FOR
CHICAGO...DATA GOES BACK TO 1872. THERE HAVE ONLY BEEN A TOTAL OF
10 DAYS IN MARCH WITH A HIGH TEMPERATURE OF 80 DEGREES. THE MOST
IN ONE YEAR WAS 2 IN 1986. FOR ROCKFORD RECORDS GO BACK TO 1906.
THERE HAVE ONLY BEEN 12 80 DEGREE DAYS IN MARCH. THE MOST IN ONE
YEAR WAS 2 IN 1907...1939...AND 1986.
ALLSOPP
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WINDS SHIFTING TO NORTHEAST LAST THIS AFTERNOON WITH A
COLD FRONT.
* POTENTIAL FOR IFR CIGS/VIS BEHIND THE FRONT OVERNIGHT.
* POTENTIAL FOR SHOWERS/TS THIS AFTERNOON INTO THE EVENING.
PAW
//DISCUSSION...UPDATED 21Z...
COLD FRONT COMING DOWN THE LAKE HAS SLOWED CONSIDERABLY AND HAVE
MADE SIGNIFICANT CHANGES TO THE GOING TIMING OF THE FORECAST.
INHERITED TAFOR HAVE WINDS FLIPPING TO NORTHEAST AT 21Z...BUT WITH
THE FRONT STALLING OUT...HAVE TRENDED BACK BY 3-4 HOURS...AND MAY
NEED TO TWEAK CLOSER WITH THE COMING AMD. RUC AND HRRR ANALYSIS
INDICATED A FLIP TO NORTHEAST...WITH THE FRONT BEGINNING TO MAKE
SOME MOVEMENT AS THE SUN GOES DOWN...PUSHING THROUGH THE EASTERN
TERMINALS BEYOND 00Z. OVERNIGHT CIG/FOG FORECAST REMAINS UNCHANGED.
SHEA
//DISCUSSION...UPDATED 18Z...
COLD FRONT MOVING INTO NORTHERN ILLINOIS AND NORTHWEST INDIANA
FROM THE NORTH THIS AFTERNOON BEFORE STALLING OUT. WINDS WILL
SHIFT TO THE NORTHEAST WITH THE FRONT. AN AREA OF LOWER CEILING
AND VISIBILITIES BEHIND THE FRONT WILL MOVE INTO THE TERMINALS
WITHIN AN HOUR OR TWO OF FRONTAL PASSAGE AND PERSIST THROUGH THE
EVENING. LOWEST CONDITIONS SHOULD BE NEAR LAKE MICHIGAN...AND A
LITTLE BETTER FURTHER AWAY FROM THE LAKE. FRONT IN THE AREA COULD
BE A FOCUS FOR SOME ISOLATED SHOWERS/TS LATE THIS AFTERNOON AND
THIS EVENING...THOUGH THE BETTER CHANCE IS SOUTH OF THE TERMINALS.
BY FRIDAY MORNING WINDS WILL SHIFT TO THE SOUTHEAST ALLOWING
WHATEVER REMAINS OF LOWER CEILINGS AND VISIBILITIES TO IMPROVE TO
VFR.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN TIMING OF WINDSHIFT.
* LOW CONFIDENCE IN IFR OCCURRING AND TIMING.
* LOW CONFIDENCE IN SHOWERS/TS.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT THROUGH SUNDAY...PREVAILING VFR...CHANCE TSRA
PRODUCING LOCAL MVFR TO IFR.
* SUNDAY NIGHT THROUGH TUESDAY NIGHT...VFR.
* WEDNESDAY...PREVAILING VFR...CHANCE TSRA PRODUCING LOCAL MVFR
TO IFR. CMS
&&
.MARINE...
321 PM CDT
THE COLD FRONT CONTINUES TO SINK SOUTH ACROSS THE SOUTHERN THIRD OF
LAKE MICHIGAN THIS AFTERNOON...AND SHOULD BE SOUTH OF LAKE MICHIGAN
BY THIS EVENING. HOWEVER...THE FRONT HAS SLOWED OVER THE PAST FEW
HOURS...SO IT MAY NOT PASS THROUGH THE SOUTHERN PORTIONS OF LAKE
MICHIGAN UNTIL LATE TONIGHT IF AT ALL. WINDS WILL ABRUPTLY CHANGE
FROM SOUTHWEST TO NORTHEAST BEHIND THE FRONT. EARLIER TODAY AREAS
IN SOUTHEAST WISCONSIN EXPERIENCED BRIEF PERIODS OF VISIBILITY
BELOW 1 MILE IMMEDIATELY BEHIND THE FRONT...BUT CURRENT
SATELLITE IMAGERY INDICATES THE FOG IS ERODING.
THEREFORE...REDUCED VISIBILITIES ARE POSSIBLE IMMEDIATELY BEHIND
THE FRONT...BUT WILL NOT PERSIST AND THE FOG MAY NOT REDUCE
VISIBILITY TO BELOW 1 MILE. THE FRONT IS EXPECTED TO STALL JUST
SOUTH OF THE LAKE AND THEN MOVE NORTHEASTWARD TOMORROW AS A WARM
FRONT.
WINDS BECOME EAST OVER THE OPEN WATER TONIGHT AS HIGH PRESSURE
PASSES OVER LAKE SUPERIOR LATE TONIGHT. WINDS CONTINUE TO VEER TO
SOUTHERLY BY FRIDAY AFTERNOON. A PROLONGED PERIOD OF LIGHT
SOUTHERLY WINDS WILL PERSIST THROUGH TUESDAY AS WE REMAIN BETWEEN
SYSTEMS.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
519 PM CDT THU MAR 15 2012
.DISCUSSION...
301 PM CDT
MAIN CONCERNS FOR THE REMAINDER OF THE AFTERNOON WILL FOCUS ON THE
BACK DOOR COLD FRONT PUSHING DOWN TO THE SRN TIP OF LAKE MICHIGAN
AND INLAND NERN/NCNTRL IL...AS WELL AS PCPN AND TS CHANCES IN THE
WARM...MOIST AIR OVER THE REMAINDER OF THE AREA. THE FRONT HAS
ALREADY PUSHED INTO ERN LAKE COUNTY...IL AND CONTINUES TO PUSH
SOUTH. THE FOG/ST BEHIND THE FRONT HAS THINNED PER LATEST VIS
IMAGERY...BUT EXPECT THAT THERE SHOULD BE AT LEAST PATCHY FOG INLAND
AND THERE IS STILL THE POTENTIAL FOR AREAS OF DENSE FOG ALONG THE
LAKE FRONT AS THE LAKE COOLED AIR PUSHES INLAND THIS EVENING.
HOWEVER...GIVEN THE LACK OF DEVELOPMENT AT THE CURRENT TIME...WILL
DEFER ANY DENSE FOG HEADLINES TO THE EVENING OR MID SHIFTS. AS FOR
TS POTENTIAL...THE LATEST VIS IMAGERY SHOWS WIDESPREAD CU
DEVELOPMENT WITH DECENT VERTICAL GROWTH OVER PORTIONS OF THE AREA
SOUTH OF I-80...WITH LESSER DEVELOPED STRATOCU TO THE NORTH. FEEL
THAT THERE IS STILL A CHANCE FOR SOME ISOLD TS DEVELOPMENT AS FAR
NORTH AS THE I-80 OR I-88 CORRIDOR AS THE BETTER INSTABILITY SPREADS
NORTHWARD TO THE COLD FRONT. THE TS CHANCES WILL CONTINUE THROUGH
THE NIGHT OVER ALL BUT THE FAR NRN AND NERN PORTIONS OF THE CWA
GIVEN THE WARM...MOIST AIRMASS...BUT GIVEN THE LACK OF A FOCUSING
ELEMENT...ANY ACTIVITY SHOULD BE ISOLD. TEMPERATURES HAVE ALSO BEEN
AN ISSUE TODAY AS WITH TEMPS RISING INTO THE UPPER 70S TO LOWER
80S. LOCATIONS SOUTH OF THE FRONT STILL HAVE THE POTENTIAL TO WARM
A BIT MORE BEFORE SUNSET AND ROCKFORD AND OHARE HAVE ALREADY BROKEN
RECORDS FOR TODAY.
TEMPERATURES WILL REMAIN THE BIG NEWS FOR THE NEXT SEVERAL DAYS.
HAVE ACTUALLY MADE LITTLE CHANGE TO THE GOING FORECAST AS FAR AS
MAXT AND MINT ARE CONCERNED. WITH THE UPPER RIDGE REMAINING PARKED
OVER THE REGION AND PERSISTENT SLY-SWLY FLOW DRAWING WARM...MOIST
AIR NWD...RECORD OR NEAR RECORD HIGH TEMPS ARE LIKELY THROUGH EARLY
NEXT WEEK. ALSO...GIVEN LITTLE CHANGE IN THE LARGE SCALE
AIRMASS...THERE WILL ALSO BE PERIODIC CHANCES FOR SHRA/TSRA THROUGH
THE ENTIRE FORECAST PERIOD. HOWEVER...THERE WILL NO SIGNIFICANT
FOCUSING MECHANISM THROUGH THE PERIOD...SO HAVE CONTAINED POPS TO
CHANCE/SLIGHT CHANCE LEVELS.
THERE ARE SOME INDICATIONS THAT THE RECORD WARMTH MAY MODERATE BY
THE END OF THE PERIOD AS THE MEDIUM RANGE FORECAST GUIDANCE SHOWS A
CUT-OFF LOW KICKING OUT OF THE SRN ROCKIES AND MOVING OUT OVER THE
SOUTH HIGH PLAINS...THOUGH THERE SHOULD STILL BE UPPER RIDGING
POKING BACK FROM THE SERN CONUS TO THE UPPER MISSISSIPPI VALLEY.
EVEN THOUGH THE GFS AND ECMWF ARE IN UNUSUALLY GOOD AGREEMENT FOR
SUCH A FEATURE AT THAT TIME RANGE...HAVE LOW CONFIDENCE IN THE
TIMING OF THIS SCENARIO AS CUT OFF LOWS ARE NOTORIOUSLY SLOWER IN
LIFTING OUT THAN THE GUIDANCE WOULD SUGGEST.
KREIN
&&
.CLIMATE...
540 AM CDT
RECORD MAXIMUM TEMPERATURES FOR CHICAGO
MAR 15 74 1995
MAR 16 78 1945
MAR 17 74 2009
RECORD MAXIMUM TEMPERATURES FOR ROCKFORD
MAR 15 73 1995
MAR 16 75 1945
MAR 17 74 2003
NORMAL NUMBER OF 70 DEGREE DAYS IN MARCH FOR BOTH CHICAGO AND
ROCKFORD IS 1.2.
RECORD NUMBER OF DAYS WITH MAX TEMP 70 OR ABOVE IN MARCH
CHICAGO 9 IN 1945...6 IN 1910 AND 1907.
ROCKFORD 11 IN 1910...7 IN 1945.
RECORD FOR CONSECUTIVE 70 DEGREE DAYS IN MARCH
CHICAGO...5 FROM MARCH 12-16 1995.
ROCKFORD...9 MARCH 23-31 1910.
TEMPERATURES IN THE 80S ARE EXTREMELY RARE IN MARCH. FOR
CHICAGO...DATA GOES BACK TO 1872. THERE HAVE ONLY BEEN A TOTAL OF
10 DAYS IN MARCH WITH A HIGH TEMPERATURE OF 80 DEGREES. THE MOST
IN ONE YEAR WAS 2 IN 1986. FOR ROCKFORD RECORDS GO BACK TO 1906.
THERE HAVE ONLY BEEN 12 80 DEGREE DAYS IN MARCH. THE MOST IN ONE
YEAR WAS 2 IN 1907...1939...AND 1986.
ALLSOPP
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* WINDS SHIFTING TO NORTHEAST THIS EVENING WITH A
COLD FRONT.
* POTENTIAL FOR IFR CIGS/VIS BEHIND THE FRONT OVERNIGHT.
SHEA
//DISCUSSION...UPDATED 21Z...
COLD FRONT COMING DOWN THE LAKE HAS SLOWED CONSIDERABLY AND HAVE
MADE SIGNIFICANT CHANGES TO THE GOING TIMING OF THE FORECAST.
INHERITED TAFOR HAVE WINDS FLIPPING TO NORTHEAST AT 21Z...BUT WITH
THE FRONT STALLING OUT...HAVE TRENDED BACK BY 3-4 HOURS...AND MAY
NEED TO TWEAK CLOSER WITH THE COMING AMD. RUC AND HRRR ANALYSIS
INDICATED A FLIP TO NORTHEAST...WITH THE FRONT BEGINNING TO MAKE
SOME MOVEMENT AS THE SUN GOES DOWN...PUSHING THROUGH THE EASTERN
TERMINALS BEYOND 00Z. OVERNIGHT CIG/FOG FORECAST REMAINS UNCHANGED.
SHEA
//DISCUSSION...UPDATED 18Z...
COLD FRONT MOVING INTO NORTHERN ILLINOIS AND NORTHWEST INDIANA
FROM THE NORTH THIS AFTERNOON BEFORE STALLING OUT. WINDS WILL
SHIFT TO THE NORTHEAST WITH THE FRONT. AN AREA OF LOWER CEILING
AND VISIBILITIES BEHIND THE FRONT WILL MOVE INTO THE TERMINALS
WITHIN AN HOUR OR TWO OF FRONTAL PASSAGE AND PERSIST THROUGH THE
EVENING. LOWEST CONDITIONS SHOULD BE NEAR LAKE MICHIGAN...AND A
LITTLE BETTER FURTHER AWAY FROM THE LAKE. FRONT IN THE AREA COULD
BE A FOCUS FOR SOME ISOLATED SHOWERS/TS LATE THIS AFTERNOON AND
THIS EVENING...THOUGH THE BETTER CHANCE IS SOUTH OF THE TERMINALS.
BY FRIDAY MORNING WINDS WILL SHIFT TO THE SOUTHEAST ALLOWING
WHATEVER REMAINS OF LOWER CEILINGS AND VISIBILITIES TO IMPROVE TO
VFR.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE IN TIMING OF WINDSHIFT.
* LOW CONFIDENCE IN IFR OCCURRING AND TIMING.
SHEA
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT THROUGH SUNDAY...PREVAILING VFR...CHANCE TSRA
PRODUCING LOCAL MVFR TO IFR.
* SUNDAY NIGHT THROUGH TUESDAY NIGHT...VFR.
* WEDNESDAY...PREVAILING VFR...CHANCE TSRA PRODUCING LOCAL MVFR
TO IFR. CMS
&&
.MARINE...
321 PM CDT
THE COLD FRONT CONTINUES TO SINK SOUTH ACROSS THE SOUTHERN THIRD OF
LAKE MICHIGAN THIS AFTERNOON...AND SHOULD BE SOUTH OF LAKE MICHIGAN
BY THIS EVENING. HOWEVER...THE FRONT HAS SLOWED OVER THE PAST FEW
HOURS...SO IT MAY NOT PASS THROUGH THE SOUTHERN PORTIONS OF LAKE
MICHIGAN UNTIL LATE TONIGHT IF AT ALL. WINDS WILL ABRUPTLY CHANGE
FROM SOUTHWEST TO NORTHEAST BEHIND THE FRONT. EARLIER TODAY AREAS
IN SOUTHEAST WISCONSIN EXPERIENCED BRIEF PERIODS OF VISIBILITY
BELOW 1 MILE IMMEDIATELY BEHIND THE FRONT...BUT CURRENT
SATELLITE IMAGERY INDICATES THE FOG IS ERODING.
THEREFORE...REDUCED VISIBILITIES ARE POSSIBLE IMMEDIATELY BEHIND
THE FRONT...BUT WILL NOT PERSIST AND THE FOG MAY NOT REDUCE
VISIBILITY TO BELOW 1 MILE. THE FRONT IS EXPECTED TO STALL JUST
SOUTH OF THE LAKE AND THEN MOVE NORTHEASTWARD TOMORROW AS A WARM
FRONT.
WINDS BECOME EAST OVER THE OPEN WATER TONIGHT AS HIGH PRESSURE
PASSES OVER LAKE SUPERIOR LATE TONIGHT. WINDS CONTINUE TO VEER TO
SOUTHERLY BY FRIDAY AFTERNOON. A PROLONGED PERIOD OF LIGHT
SOUTHERLY WINDS WILL PERSIST THROUGH TUESDAY AS WE REMAIN BETWEEN
SYSTEMS.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
337 PM CDT THU MAR 15 2012
.DISCUSSION...
301 PM CDT
MAIN CONCERNS FOR THE REMAINDER OF THE AFTERNOON WILL FOCUS ON THE
BACK DOOR COLD FRONT PUSHING DOWN TO THE SRN TIP OF LAKE MICHIGAN
AND INLAND NERN/NCNTRL IL...AS WELL AS PCPN AND TS CHANCES IN THE
WARM...MOIST AIR OVER THE REMAINDER OF THE AREA. THE FRONT HAS
ALREADY PUSHED INTO ERN LAKE COUNTY...IL AND CONTINUES TO PUSH
SOUTH. THE FOG/ST BEHIND THE FRONT HAS THINNED PER LATEST VIS
IMAGERY...BUT EXPECT THAT THERE SHOULD BE AT LEAST PATCHY FOG INLAND
AND THERE IS STILL THE POTENTIAL FOR AREAS OF DENSE FOG ALONG THE
LAKE FRONT AS THE LAKE COOLED AIR PUSHES INLAND THIS EVENING.
HOWEVER...GIVEN THE LACK OF DEVELOPMENT AT THE CURRENT TIME...WILL
DEFER ANY DENSE FOG HEADLINES TO THE EVENING OR MID SHIFTS. AS FOR
TS POTENTIAL...THE LATEST VIS IMAGERY SHOWS WIDESPREAD CU
DEVELOPMENT WITH DECENT VERTICAL GROWTH OVER PORTIONS OF THE AREA
SOUTH OF I-80...WITH LESSER DEVELOPED STRATOCU TO THE NORTH. FEEL
THAT THERE IS STILL A CHANCE FOR SOME ISOLD TS DEVELOPMENT AS FAR
NORTH AS THE I-80 OR I-88 CORRIDOR AS THE BETTER INSTABILITY SPREADS
NORTHWARD TO THE COLD FRONT. THE TS CHANCES WILL CONTINUE THROUGH
THE NIGHT OVER ALL BUT THE FAR NRN AND NERN PORTIONS OF THE CWA
GIVEN THE WARM...MOIST AIRMASS...BUT GIVEN THE LACK OF A FOCUSING
ELEMENT...ANY ACTIVITY SHOULD BE ISOLD. TEMPERATURES HAVE ALSO BEEN
AN ISSUE TODAY AS WITH TEMPS RISING INTO THE UPPER 70S TO LOWER
80S. LOCATIONS SOUTH OF THE FRONT STILL HAVE THE POTENTIAL TO WARM
A BIT MORE BEFORE SUNSET AND ROCKFORD AND OHARE HAVE ALREADY BROKEN
RECORDS FOR TODAY.
TEMPERATURES WILL REMAIN THE BIG NEWS FOR THE NEXT SEVERAL DAYS.
HAVE ACTUALLY MADE LITTLE CHANGE TO THE GOING FORECAST AS FAR AS
MAXT AND MINT ARE CONCERNED. WITH THE UPPER RIDGE REMAINING PARKED
OVER THE REGION AND PERSISTENT SLY-SWLY FLOW DRAWING WARM...MOIST
AIR NWD...RECORD OR NEAR RECORD HIGH TEMPS ARE LIKELY THROUGH EARLY
NEXT WEEK. ALSO...GIVEN LITTLE CHANGE IN THE LARGE SCALE
AIRMASS...THERE WILL ALSO BE PERIODIC CHANCES FOR SHRA/TSRA THROUGH
THE ENTIRE FORECAST PERIOD. HOWEVER...THERE WILL NO SIGNIFICANT
FOCUSING MECHANISM THROUGH THE PERIOD...SO HAVE CONTAINED POPS TO
CHANCE/SLIGHT CHANCE LEVELS.
THERE ARE SOME INDICATIONS THAT THE RECORD WARMTH MAY MODERATE BY
THE END OF THE PERIOD AS THE MEDIUM RANGE FORECAST GUIDANCE SHOWS A
CUT-OFF LOW KICKING OUT OF THE SRN ROCKIES AND MOVING OUT OVER THE
SOUTH HIGH PLAINS...THOUGH THERE SHOULD STILL BE UPPER RIDGING
POKING BACK FROM THE SERN CONUS TO THE UPPER MISSISSIPPI VALLEY.
EVEN THOUGH THE GFS AND ECMWF ARE IN UNUSUALLY GOOD AGREEMENT FOR
SUCH A FEATURE AT THAT TIME RANGE...HAVE LOW CONFIDENCE IN THE
TIMING OF THIS SCENARIO AS CUT OFF LOWS ARE NOTORIOUSLY SLOWER IN
LIFTING OUT THAN THE GUIDANCE WOULD SUGGEST.
KREIN
&&
.CLIMATE...
540 AM CDT
RECORD MAXIMUM TEMPERATURES FOR CHICAGO
MAR 15 74 1995
MAR 16 78 1945
MAR 17 74 2009
RECORD MAXIMUM TEMPERATURES FOR ROCKFORD
MAR 15 73 1995
MAR 16 75 1945
MAR 17 74 2003
NORMAL NUMBER OF 70 DEGREE DAYS IN MARCH FOR BOTH CHICAGO AND
ROCKFORD IS 1.2.
RECORD NUMBER OF DAYS WITH MAX TEMP 70 OR ABOVE IN MARCH
CHICAGO 9 IN 1945...6 IN 1910 AND 1907.
ROCKFORD 11 IN 1910...7 IN 1945.
RECORD FOR CONSECUTIVE 70 DEGREE DAYS IN MARCH
CHICAGO...5 FROM MARCH 12-16 1995.
ROCKFORD...9 MARCH 23-31 1910.
TEMPERATURES IN THE 80S ARE EXTREMELY RARE IN MARCH. FOR
CHICAGO...DATA GOES BACK TO 1872. THERE HAVE ONLY BEEN A TOTAL OF
10 DAYS IN MARCH WITH A HIGH TEMPERATURE OF 80 DEGREES. THE MOST
IN ONE YEAR WAS 2 IN 1986. FOR ROCKFORD RECORDS GO BACK TO 1906.
THERE HAVE ONLY BEEN 12 80 DEGREE DAYS IN MARCH. THE MOST IN ONE
YEAR WAS 2 IN 1907...1939...AND 1986.
ALLSOPP
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* WINDS SHIFTING TO NORTHEAST LAST THIS AFTERNOON WITH A
COLD FRONT.
* POTENTIAL FOR IFR CIGS/VIS BEHIND THE FRONT OVERNIGHT.
* POTENTIAL FOR SHOWERS/TS THIS AFTERNOON INTO THE EVENING.
PAW
//DISCUSSION...UPDATED 21Z...
COLD FRONT COMING DOWN THE LAKE HAS SLOWED CONSIDERABLY AND HAVE
MADE SIGNIFICANT CHANGES TO THE GOING TIMING OF THE FORECAST.
INHERITED TAFOR HAVE WINDS FLIPPING TO NORTHEAST AT 21Z...BUT WITH
THE FRONT STALLING OUT...HAVE TRENDED BACK BY 3-4 HOURS...AND MAY
NEED TO TWEAK CLOSER WITH THE COMING AMD. RUC AND HRRR ANALYSIS
INDICATED A FLIP TO NORTHEAST...WITH THE FRONT BEGINNING TO MAKE
SOME MOVEMENT AS THE SUN GOES DOWN...PUSHING THROUGH THE EASTERN
TERMINALS BEYOND 00Z. OVERNIGHT CIG/FOG FORECAST REMAINS UNCHANGED.
SHEA
//DISCUSSION...UPDATED 18Z...
COLD FRONT MOVING INTO NORTHERN ILLINOIS AND NORTHWEST INDIANA
FROM THE NORTH THIS AFTERNOON BEFORE STALLING OUT. WINDS WILL
SHIFT TO THE NORTHEAST WITH THE FRONT. AN AREA OF LOWER CEILING
AND VISIBILITIES BEHIND THE FRONT WILL MOVE INTO THE TERMINALS
WITHIN AN HOUR OR TWO OF FRONTAL PASSAGE AND PERSIST THROUGH THE
EVENING. LOWEST CONDITIONS SHOULD BE NEAR LAKE MICHIGAN...AND A
LITTLE BETTER FURTHER AWAY FROM THE LAKE. FRONT IN THE AREA COULD
BE A FOCUS FOR SOME ISOLATED SHOWERS/TS LATE THIS AFTERNOON AND
THIS EVENING...THOUGH THE BETTER CHANCE IS SOUTH OF THE TERMINALS.
BY FRIDAY MORNING WINDS WILL SHIFT TO THE SOUTHEAST ALLOWING
WHATEVER REMAINS OF LOWER CEILINGS AND VISIBILITIES TO IMPROVE TO
VFR.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN TIMING OF WINDSHIFT.
* LOW CONFIDENCE IN IFR OCCURRING AND TIMING.
* LOW CONFIDENCE IN SHOWERS/TS.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
* FRIDAY NIGHT THROUGH SUNDAY...PREVAILING VFR...CHANCE TSRA
PRODUCING LOCAL MVFR TO IFR.
* SUNDAY NIGHT THROUGH TUESDAY NIGHT...VFR.
* WEDNESDAY...PREVAILING VFR...CHANCE TSRA PRODUCING LOCAL MVFR
TO IFR. CMS
&&
.MARINE...
321 PM CDT
THE COLD FRONT CONTINUES TO SINK SOUTH ACROSS THE SOUTHERN THIRD OF
LAKE MICHIGAN THIS AFTERNOON...AND SHOULD BE SOUTH OF LAKE MICHIGAN
BY THIS EVENING. HOWEVER...THE FRONT HAS SLOWED OVER THE PAST FEW
HOURS...SO IT MAY NOT PASS THROUGH THE SOUTHERN PORTIONS OF LAKE
MICHIGAN UNTIL LATE TONIGHT IF AT ALL. WINDS WILL ABRUPTLY CHANGE
FROM SOUTHWEST TO NORTHEAST BEHIND THE FRONT. EARLIER TODAY AREAS
IN SOUTHEAST WISCONSIN EXPERIENCED BRIEF PERIODS OF VISIBILITY
BELOW 1 MILE IMMEDIATELY BEHIND THE FRONT...BUT CURRENT
SATELLITE IMAGERY INDICATES THE FOG IS ERODING.
THEREFORE...REDUCED VISIBILITIES ARE POSSIBLE IMMEDIATELY BEHIND
THE FRONT...BUT WILL NOT PERSIST AND THE FOG MAY NOT REDUCE
VISIBILITY TO BELOW 1 MILE. THE FRONT IS EXPECTED TO STALL JUST
SOUTH OF THE LAKE AND THEN MOVE NORTHEASTWARD TOMORROW AS A WARM
FRONT.
WINDS BECOME EAST OVER THE OPEN WATER TONIGHT AS HIGH PRESSURE
PASSES OVER LAKE SUPERIOR LATE TONIGHT. WINDS CONTINUE TO VEER TO
SOUTHERLY BY FRIDAY AFTERNOON. A PROLONGED PERIOD OF LIGHT
SOUTHERLY WINDS WILL PERSIST THROUGH TUESDAY AS WE REMAIN BETWEEN
SYSTEMS.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
431 PM EDT THU MAR 15 2012
.UPDATE...
AVIATION SECTIONS UPDATED
&&
.SYNOPSIS...
A BROAD UPPER LEVEL RIDGE WILL PERSIST ACROSS THE EASTERN PART OF
THE COUNTRY INTO THE MIDDLE OF NEXT WEEK...WITH TEMPERATURES
CONTINUING AT WELL ABOVE NORMAL AND NEAR RECORD LEVELS. SEVERAL
DISTURBANCES ALOFT WILL PROGRESS THROUGH THE UPPER RIDGE...PROVIDING
PERIODIC CHANCES FOR THUNDERSTORMS OVER CENTRAL INDIANA THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF THIS AFTERNOON INTO TONIGHT/...
AS OF 130 PM THIS AFTERNOON...ALL EYES TURN TO THE MCS MOVING TOWARD
THE SW FORECAST AREA FROM SE MO/SW IL. THIS FEATURE IS ASSOCIATED
WITH AN UPPER VORT MAX AND ALL SHORT TERM GUIDANCE AGREES ON
MOVING THIS FEATURE THROUGH THE OH VALLEY LATE THIS AFTERNOON AND
EVENING. SCATTERED CONVECTION WILL MOVE INTO CWA IN THE NEXT HOUR OR
SO AND THEN SPREAD QUICKLY AS DAYTIME HEATING WILL HAVE ALLOWED MANY
LOCATIONS TO REACH THEIR CONVECTIVE TEMPERATURES ACROSS THE REST OF
CENTRAL INDIANA AND THE ENTIRE OHIO VALLEY REMAINS UNDER A MOIST AND
UNSTABLE AIRMASS. THE PRESENCE OF A WEAK FRONTAL BOUNDARY TO THE
NORTH WILL LIKELY HAVE SOME INFLUENCE ON CONVECTION BUT STILL
APPEARS THE VORT MAX/MCS WILL BE THE MAIN DRIVING FEATURE
RESPONSIBLE FOR INDUCING CONVECTION OVER THE CWA AND THE OHIO VALLEY
BY LATE THIS AFTERNOON AND INTO THE EVENING.
EVEN THOUGH THE SLIGHT RISK HAS BEEN EXPANDED FARTHER NORTHWARD WITH
SPC/S MORNING UPDATE...BELIEVE STRONGEST OF THE CONVECTION SHOULD BE
FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST AREA (ALONG AND SOUTH
OF I-70) AS THE DISTURBANCE TRACKS INTO THE SRN OHIO VALLEY THROUGH
THIS EVENING. WILL CONTINUE TO CARRY SCATTERED TO LIKELY TSTM POPS
IN THE FORECAST (ESP AROUND AND S OF I-70) BUT ADDED THE THREAT OF
SVR WX (FOR THE SLIGHT RISK AREA) INCLUDING LARGE HAIL AND VERY
HEAVY RAINFALL AS THE MAIN THREATS. AS MENTIONED EARLIER...BL SHEAR
VALUES REMAIN WEAK...HOWEVER WITH WBZERO VALUES ABOVE 8KFT AND STEEP
LAPSE RATES PRESENT...A FEW OF THE MORE INTENSE STORMS WILL BE
CAPABLE OF PRODUCING LARGE HAIL AND POSSIBLY SOME GUSTY WINDS.
BULK OF THE TSTM...AND ESPECIALLY THE SEVERE POTENTIAL WILL DIMINISH
LATER THIS EVENING. CHANCES CONVECTION WILL CONTINUE OVERNIGHT AS
AFOREMENTIONED UPPER WAVE DRIFTS EAST THROUGH THE OHIO VALLEY. FOCUS
FOR HIGHEST POPS WILL REMAIN SOUTH OF I-70 THROUGH THE OVERNIGHT
HOURS...LOWERING CHANCES EVEN MORE AFTER MIDNIGHT AS WEAK RIDGING
ALOFT BUILDS BACK INTO THE REGION BEHIND THE FEATURE. A MOS BLEND
SEEMS REASONABLE TO LOW TONIGHT RANGING FROM THE UPPER 50S TO AROUND
60.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FORECAST PATTERN REMAINS UNCHANGED FOR THE REST OF THE WEEK AND
ACTUALLY INTO NEXT WEEK. ABOVE NORMAL/NEAR RECORD HIGHS WILL
CONTINUE DURING THE PERIOD AND WE WILL ALSO HAVE ON AND OFF CHANCES
FOR THUNDERSTORMS THROUGH AT LEAST EARLY NEXT WEEK. FORECAST
CHALLENGE IS TRYING TO DECIPHER BETWEEN THE DRY AND WET PERIODS.
LUCKILY ALL GUIDANCE IS SIMILAR IN HANDLING OF MAIN FEATURES THROUGH
THE PERIOD.
AGREE WITH PREVIOUS FORECAST THINKING AND ACTUALLY HAVE LOWERED POPS
EVEN MORE FOR FRIDAY FROM PREVIOUS FORECAST AS CONFIDENCE IS LOWER
IN MORE SUBSTANTIAL PRECIP COVERAGE. WINDS AND OVERALL FORCING ALOFT
WEAKEN AS HEIGHTS RISE AGAIN IN RESPONSE TO THE EXPANSION OF THE
UPPER RIDGE...WITH CONVECTIVE DEVELOPMENT LIKELY TO BE LARGELY
DEPENDENT ON AVAILABLE INSTABILITY. WILL AGAIN CARRY HIGHEST POPS
(30-40 PERCENT) OVER THE SOUTH/SOUTHEAST COUNTIES...DUE TO THEIR
CLOSES PROXIMITY TO DEPARTING UPPER WAVE. OTHERWISE ONLY ANTICIPATE
ISOLATED CONVECTION NORTH OF I-70.
THERE IS MORE SUBSTANTIAL POTENTIAL FOR CONVECTION LATER IN THE DAY
SATURDAY AS LOW PRESSURE PULLS OUT INTO THE CENTRAL PLAINS. GUIDANCE
SHOWS A STRONGER SHORT WAVE ALOFT OUT OF THE SOUTHERN PLAINS
REACHING THE REGION DURING THIS TIME. THIS FEATURE SHOULD SPURN
INCREASED CONVECTION...ESPECIALLY IF THE FEATURE ARRIVES DURING PEAK
HEATING IN THE LATE AFTERNOON. HAVE BUMPED UP POPS TO 40 PERCENT
SCATTERED DURING THE AFTERNOON AND EVENING AND LASTING THROUGH
SUNDAY. HEAVY RAIN AND LOCALIZED FLOODING MAY BECOME AN ISSUE WITH
PRECIP WATER VALUES AT OR ABOVE 1 INCH FOR MUCH OF THE PERIOD.
IN TERMS OF TEMPERATURES...POTENTIAL FOR RECORD BREAKING HIGHS AT
IND WILL CONTINUE THROUGH THE PERIOD. WITH NO APPRECIABLE CHANGE IN
THE AIRMASS...EXPECT HIGHS TO BE VERY SIMILAR FRIDAY THROUGH SUNDAY.
CONTINUING THE TREND OF RUNNING A FEW DEGREES ABOVE MOS AS HIGHS IN
THE UPPER 70S AND LOWER 80S ARE LIKELY THROUGH THE PERIOD. RECORD HIGHS
AT IND ARE 79 FROM 1945 ON FRIDAY AND 76 FROM 1894 ON SATURDAY.
AND 76 ON SUNDAY FROM 1903. LOWS WILL REMAIN NEAR 60 THROUGH THE
PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
EARLY IN THE LONG TERM THINK HIGH TEMPERATURES ARE TOO LOW BASED ON
RECENT TRENDS AND FORECAST 850 MB TEMPERATURES THAT ARE SIMILAR TO
WHAT/S BEEN SEEN THE PAST FEW DAYS. THEREFORE INCREASED
INITIALIZATION BY AT LEAST A FEW DEGREES FOR HIGHS FROM MONDAY
THROUGH THURSDAY. ALSO WITH UPPER RIDGE AXIS BUILDING OVER THE AREA
EARLY IN THE LONG TERM REMOVED THE SLIGHT TO LOW CHANCE POPS FROM
SUNDAY NIGHT AND MONDAY AND INSTEAD EXPECT TO SEE DRY WEATHER UNTIL
AT LEAST WEDNESDAY.
MODELS ARE SHOWING A DECENT BIT OF VARIABILITY IN THE LATTER HALF OF
THE LONG TERM IN THE LARGE SCALE PATTERN. WHILE GFS/ECMWF/GEFS SEEM
TO AGREE ON A CUT OFF LOW DEVELOPING OUT OF THE WESTERN TROUGH THERE
IS A HIGH AMOUNT OF VARIABILITY ON WHERE THIS HAPPENS AND HOW MUCH
RIDGING REMAINS OVER CENTRAL INDIANA AND FOR HOW LONG. WITH THIS IN
MIND WILL STICK CLOSE TO INITIALIZATION FOR POPS WEDNESDAY NIGHT AND
THURSDAY.
&&
.AVIATION /DISCUSSION FOR THE 21Z IND TAF UPDATE/...
RADAR TRENDS INDICATE AN AREA OF SHOWERS AND THUNDERSTORMS OVER
SOUTH CENTRAL INDIANA PUSHING NORTHEAST. DISTANCE SPEED PROJECTION
INDICATE THAT THESE FEATURES SHOULD PUSH NEAR THE IND TAF SITE IN
THE NEXT 1-2 HOURS. BRIEF MVFR CONDITIONS ALONG WITH LIGHTING WILL
BE POSSIBLE AS THE STORMS PASS.
LITTLE CHANGE TO THE LATER PARTS OF THE FORECAST AS LOSS OF
DAYTIME HEATING IS EXPECTED TO RESULT IN DIMINISHING TSRA.
/DISCUSSION FOR 151800Z TAF ISSUANCE/...
SOME WIND GUSTS OF AROUND 20 KTS OUT OF 220 COULD BE SEEN THIS
AFTERNOON ACCORDING TO RUC SOUNDINGS.
INSTABILITY IS INCREASING AT THE SITES AND RAPID UPDATE MODELS ARE
STILL SHOWING CONVECTIVE DEVELOPMENT ACROSS PARTS OF THE AREA BY
19Z. WILL USE THIS AS A START FOR THE INCLUSION OF VCTS BUT WILL NOT
DROP CATEGORY AT ANY SITE BESIDES KBMG AS NATURE OF CONVECTION WILL
BE POP UP AND SCATTERED. KBMG IS THE EXCEPTION TO THIS AS A LINE OF
STORMS ACROSS SOUTHERN ILLINOIS AT 1630Z IS HEADED TOWARD KBMG...AND
HAVE TIMED THIS LINE IN AND INCLUDED TEMPO THUNDER AND MVFR FOR A
COUPLE HOURS AROUND THE LINES ARRIVAL. CURRENT MOVEMENT AND TIMING
HAS THIS LINE MISSING THE REST OF THE SITES.
SHOULD SEE THIS ROUND OF CONVECTION MOVING OUT OF THE AREA BY AROUND
0-1Z. COULD SEE SOME ELEVATED ACTIVITY DEVELOP OVERNIGHT BUT THINK
LIKELIHOOD IS LOW ENOUGH TO LEAVE OUT. FORECAST SOUNDINGS DO SHOW A
STRONG INVERSION DEVELOPING OVERNIGHT AND HAVE CONCERNS THAT THIS
COULD LEAD TO LOWER VISIBILITIES...BUT WITH SOME CLOUD COVER...SOME
MIXING...AND CHANCES FOR PRECIP JUST DON/T FEEL CONFIDENT ENOUGH TO
GO LOWER THAN MVFR AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....CP
AVIATION...CP/JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
209 PM EDT THU MAR 15 2012
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
A BROAD UPPER LEVEL RIDGE WILL PERSIST ACROSS THE EASTERN PART OF
THE COUNTRY INTO THE MIDDLE OF NEXT WEEK...WITH TEMPERATURES
CONTINUING AT WELL ABOVE NORMAL AND NEAR RECORD LEVELS. SEVERAL
DISTURBANCES ALOFT WILL PROGRESS THROUGH THE UPPER RIDGE...PROVIDING
PERIODIC CHANCES FOR THUNDERSTORMS OVER CENTRAL INDIANA THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF THIS AFTERNOON INTO TONIGHT/...
AS OF 130 PM THIS AFTERNOON...ALL EYES TURN TO THE MCS MOVING TOWARD
THE SW FORECAST AREA FROM SE MO/SW IL. THIS FEATURE IS ASSOCIATED
WITH AN UPPER VORT MAX AND ALL SHORT TERM GUIDANCE AGREES ON
MOVING THIS FEATURE THROUGH THE OH VALLEY LATE THIS AFTERNOON AND
EVENING. SCATTERED CONVECTION WILL MOVE INTO CWA IN THE NEXT HOUR OR
SO AND THEN SPREAD QUICKLY AS DAYTIME HEATING WILL HAVE ALLOWED MANY
LOCATIONS TO REACH THEIR CONVECTIVE TEMPERATURES ACROSS THE REST OF
CENTRAL INDIANA AND THE ENTIRE OHIO VALLEY REMAINS UNDER A MOIST AND
UNSTABLE AIRMASS. THE PRESENCE OF A WEAK FRONTAL BOUNDARY TO THE
NORTH WILL LIKELY HAVE SOME INFLUENCE ON CONVECTION BUT STILL
APPEARS THE VORT MAX/MCS WILL BE THE MAIN DRIVING FEATURE
RESPONSIBLE FOR INDUCING CONVECTION OVER THE CWA AND THE OHIO VALLEY
BY LATE THIS AFTERNOON AND INTO THE EVENING.
EVEN THOUGH THE SLIGHT RISK HAS BEEN EXPANDED FARTHER NORTHWARD WITH
SPC/S MORNING UPDATE...BELIEVE STRONGEST OF THE CONVECTION SHOULD BE
FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST AREA (ALONG AND SOUTH
OF I-70) AS THE DISTURBANCE TRACKS INTO THE SRN OHIO VALLEY THROUGH
THIS EVENING. WILL CONTINUE TO CARRY SCATTERED TO LIKELY TSTM POPS
IN THE FORECAST (ESP AROUND AND S OF I-70) BUT ADDED THE THREAT OF
SVR WX (FOR THE SLIGHT RISK AREA) INCLUDING LARGE HAIL AND VERY
HEAVY RAINFALL AS THE MAIN THREATS. AS MENTIONED EARLIER...BL SHEAR
VALUES REMAIN WEAK...HOWEVER WITH WBZERO VALUES ABOVE 8KFT AND STEEP
LAPSE RATES PRESENT...A FEW OF THE MORE INTENSE STORMS WILL BE
CAPABLE OF PRODUCING LARGE HAIL AND POSSIBLY SOME GUSTY WINDS.
BULK OF THE TSTM...AND ESPECIALLY THE SEVERE POTENTIAL WILL DIMINISH
LATER THIS EVENING. CHANCES CONVECTION WILL CONTINUE OVERNIGHT AS
AFOREMENTIONED UPPER WAVE DRIFTS EAST THROUGH THE OHIO VALLEY. FOCUS
FOR HIGHEST POPS WILL REMAIN SOUTH OF I-70 THROUGH THE OVERNIGHT
HOURS...LOWERING CHANCES EVEN MORE AFTER MIDNIGHT AS WEAK RIDGING
ALOFT BUILDS BACK INTO THE REGION BEHIND THE FEATURE. A MOS BLEND
SEEMS REASONABLE TO LOW TONIGHT RANGING FROM THE UPPER 50S TO AROUND
60.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FORECAST PATTERN REMAINS UNCHANGED FOR THE REST OF THE WEEK AND
ACTUALLY INTO NEXT WEEK. ABOVE NORMAL/NEAR RECORD HIGHS WILL
CONTINUE DURING THE PERIOD AND WE WILL ALSO HAVE ON AND OFF CHANCES
FOR THUNDERSTORMS THROUGH AT LEAST EARLY NEXT WEEK. FORECAST
CHALLENGE IS TRYING TO DECIPHER BETWEEN THE DRY AND WET PERIODS.
LUCKILY ALL GUIDANCE IS SIMILAR IN HANDLING OF MAIN FEATURES THROUGH
THE PERIOD.
AGREE WITH PREVIOUS FORECAST THINKING AND ACTUALLY HAVE LOWERED POPS
EVEN MORE FOR FRIDAY FROM PREVIOUS FORECAST AS CONFIDENCE IS LOWER
IN MORE SUBSTANTIAL PRECIP COVERAGE. WINDS AND OVERALL FORCING ALOFT
WEAKEN AS HEIGHTS RISE AGAIN IN RESPONSE TO THE EXPANSION OF THE
UPPER RIDGE...WITH CONVECTIVE DEVELOPMENT LIKELY TO BE LARGELY
DEPENDENT ON AVAILABLE INSTABILITY. WILL AGAIN CARRY HIGHEST POPS
(30-40 PERCENT) OVER THE SOUTH/SOUTHEAST COUNTIES...DUE TO THEIR
CLOSES PROXIMITY TO DEPARTING UPPER WAVE. OTHERWISE ONLY ANTICIPATE
ISOLATED CONVECTION NORTH OF I-70.
THERE IS MORE SUBSTANTIAL POTENTIAL FOR CONVECTION LATER IN THE DAY
SATURDAY AS LOW PRESSURE PULLS OUT INTO THE CENTRAL PLAINS. GUIDANCE
SHOWS A STRONGER SHORT WAVE ALOFT OUT OF THE SOUTHERN PLAINS
REACHING THE REGION DURING THIS TIME. THIS FEATURE SHOULD SPURN
INCREASED CONVECTION...ESPECIALLY IF THE FEATURE ARRIVES DURING PEAK
HEATING IN THE LATE AFTERNOON. HAVE BUMPED UP POPS TO 40 PERCENT
SCATTERED DURING THE AFTERNOON AND EVENING AND LASTING THROUGH
SUNDAY. HEAVY RAIN AND LOCALIZED FLOODING MAY BECOME AN ISSUE WITH
PRECIP WATER VALUES AT OR ABOVE 1 INCH FOR MUCH OF THE PERIOD.
IN TERMS OF TEMPERATURES...POTENTIAL FOR RECORD BREAKING HIGHS AT
IND WILL CONTINUE THROUGH THE PERIOD. WITH NO APPRECIABLE CHANGE IN
THE AIRMASS...EXPECT HIGHS TO BE VERY SIMILAR FRIDAY THROUGH SUNDAY.
CONTINUING THE TREND OF RUNNING A FEW DEGREES ABOVE MOS AS HIGHS IN
THE UPPER 70S AND LOWER 80S ARE LIKELY THROUGH THE PERIOD. RECORD HIGHS
AT IND ARE 79 FROM 1945 ON FRIDAY AND 76 FROM 1894 ON SATURDAY.
AND 76 ON SUNDAY FROM 1903. LOWS WILL REMAIN NEAR 60 THROUGH THE
PERIOD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
EARLY IN THE LONG TERM THINK HIGH TEMPERATURES ARE TOO LOW BASED ON
RECENT TRENDS AND FORECAST 850 MB TEMPERATURES THAT ARE SIMILAR TO
WHAT/S BEEN SEEN THE PAST FEW DAYS. THEREFORE INCREASED
INITIALIZATION BY AT LEAST A FEW DEGREES FOR HIGHS FROM MONDAY
THROUGH THURSDAY. ALSO WITH UPPER RIDGE AXIS BUILDING OVER THE AREA
EARLY IN THE LONG TERM REMOVED THE SLIGHT TO LOW CHANCE POPS FROM
SUNDAY NIGHT AND MONDAY AND INSTEAD EXPECT TO SEE DRY WEATHER UNTIL
AT LEAST WEDNESDAY.
MODELS ARE SHOWING A DECENT BIT OF VARIABILITY IN THE LATTER HALF OF
THE LONG TERM IN THE LARGE SCALE PATTERN. WHILE GFS/ECMWF/GEFS SEEM
TO AGREE ON A CUT OFF LOW DEVELOPING OUT OF THE WESTERN TROUGH THERE
IS A HIGH AMOUNT OF VARIABILITY ON WHERE THIS HAPPENS AND HOW MUCH
RIDGING REMAINS OVER CENTRAL INDIANA AND FOR HOW LONG. WITH THIS IN
MIND WILL STICK CLOSE TO INITIALIZATION FOR POPS WEDNESDAY NIGHT AND
THURSDAY.
&&
.AVIATION /DISCUSSION FOR 151800Z TAF ISSUANCE/...
SOME WIND GUSTS OF AROUND 20 KTS OUT OF 220 COULD BE SEEN THIS
AFTERNOON ACCORDING TO RUC SOUNDINGS.
INSTABILITY IS INCREASING AT THE SITES AND RAPID UPDATE MODELS ARE
STILL SHOWING CONVECTIVE DEVELOPMENT ACROSS PARTS OF THE AREA BY
19Z. WILL USE THIS AS A START FOR THE INCLUSION OF VCTS BUT WILL NOT
DROP CATEGORY AT ANY SITE BESIDES KBMG AS NATURE OF CONVECTION WILL
BE POP UP AND SCATTERED. KBMG IS THE EXCEPTION TO THIS AS A LINE OF
STORMS ACROSS SOUTHERN ILLINOIS AT 1630Z IS HEADED TOWARD KBMG...AND
HAVE TIMED THIS LINE IN AND INCLUDED TEMPO THUNDER AND MVFR FOR A
COUPLE HOURS AROUND THE LINES ARRIVAL. CURRENT MOVEMENT AND TIMING
HAS THIS LINE MISSING THE REST OF THE SITES.
SHOULD SEE THIS ROUND OF CONVECTION MOVING OUT OF THE AREA BY AROUND
0-1Z. COULD SEE SOME ELEVATED ACTIVITY DEVELOP OVERNIGHT BUT THINK
LIKELIHOOD IS LOW ENOUGH TO LEAVE OUT. FORECAST SOUNDINGS DO SHOW A
STRONG INVERSION DEVELOPING OVERNIGHT AND HAVE CONCERNS THAT THIS
COULD LEAD TO LOWER VISIBILITIES...BUT WITH SOME CLOUD COVER...SOME
MIXING...AND CHANCES FOR PRECIP JUST DON/T FEEL CONFIDENT ENOUGH TO
GO LOWER THAN MVFR AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....CP
AVIATION...CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
202 PM EDT THU MAR 15 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED
BELOW.
&&
.SYNOPSIS...
A BROAD UPPER LEVEL RIDGE WILL PERSIST ACROSS THE EASTERN PART OF
THE COUNTRY INTO THE MIDDLE OF NEXT WEEK...WITH TEMPERATURES
CONTINUING AT WELL ABOVE NORMAL AND NEAR RECORD LEVELS. SEVERAL
DISTURBANCES ALOFT WILL PROGRESS THROUGH THE UPPER RIDGE...PROVIDING
PERIODIC CHANCES FOR THUNDERSTORMS OVER CENTRAL INDIANA THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF THIS AFTERNOON INTO TONIGHT/...
AS OF 130 PM THIS AFTERNOON...ALL EYES TURN TO THE MCS MOVING TOWARD
THE SW FORECAST AREA FROM SE MO/SW IL. THIS FEATURE IS ASSOCIATED
WITH AN UPPER VORT MAX AND ALL SHORT TERM GUIDANCE AGREES ON
MOVING THIS FEATURE THROUGH THE OH VALLEY LATE THIS AFTERNOON AND
EVENING. SCATTERED CONVECTION WILL MOVE INTO CWA IN THE NEXT HOUR OR
SO AND THEN SPREAD QUICKLY AS DAYTIME HEATING WILL HAVE ALLOWED MANY
LOCATIONS TO REACH THEIR CONVECTIVE TEMPERATURES ACROSS THE REST OF
CENTRAL INDIANA AND THE ENTIRE OHIO VALLEY REMAINS UNDER A MOIST AND
UNSTABLE AIRMASS. THE PRESENCE OF A WEAK FRONTAL BOUNDARY TO THE
NORTH WILL LIKELY HAVE SOME INFLUENCE ON CONVECTION BUT STILL
APPEARS THE VORT MAX/MCS WILL BE THE MAIN DRIVING FEATURE
RESPONSIBLE FOR INDUCING CONVECTION OVER THE CWA AND THE OHIO VALLEY
BY LATE THIS AFTERNOON AND INTO THE EVENING.
EVEN THOUGH THE SLIGHT RISK HAS BEEN EXPANDED FARTHER NORTHWARD WITH
SPC/S MORNING UPDATE...BELIEVE STRONGEST OF THE CONVECTION SHOULD BE
FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST AREA (ALONG AND SOUTH
OF I-70) AS THE DISTURBANCE TRACKS INTO THE SRN OHIO VALLEY THROUGH
THIS EVENING. WILL CONTINUE TO CARRY SCATTERED TO LIKELY TSTM POPS
IN THE FORECAST (ESP AROUND AND S OF I-70) BUT ADDED THE THREAT OF
SVR WX (FOR THE SLIGHT RISK AREA) INCLUDING LARGE HAIL AND VERY
HEAVY RAINFALL AS THE MAIN THREATS. AS MENTIONED EARLIER...BL SHEAR
VALUES REMAIN WEAK...HOWEVER WITH WBZERO VALUES ABOVE 8KFT AND STEEP
LAPSE RATES PRESENT...A FEW OF THE MORE INTENSE STORMS WILL BE
CAPABLE OF PRODUCING LARGE HAIL AND POSSIBLY SOME GUSTY WINDS.
BULK OF THE TSTM...AND ESPECIALLY THE SEVERE POTENTIAL WILL DIMINISH
LATER THIS EVENING. CHANCES CONVECTION WILL CONTINUE OVERNIGHT AS
AFOREMENTIONED UPPER WAVE DRIFTS EAST THROUGH THE OHIO VALLEY. FOCUS
FOR HIGHEST POPS WILL REMAIN SOUTH OF I-70 THROUGH THE OVERNIGHT
HOURS...LOWERING CHANCES EVEN MORE AFTER MIDNIGHT AS WEAK RIDGING
ALOFT BUILDS BACK INTO THE REGION BEHIND THE FEATURE. A MOS BLEND
SEEMS REASONABLE TO LOW TONIGHT RANGING FROM THE UPPER 50S TO AROUND
60.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
FORECAST PATTERN REMAINS UNCHANGED FOR THE REST OF THE WEEK AND
ACTUALLY INTO NEXT WEEK. ABOVE NORMAL/NEAR RECORD HIGHS WILL
CONTINUE DURING THE PERIOD AND WE WILL ALSO HAVE ON AND OFF CHANCES
FOR THUNDERSTORMS THROUGH AT LEAST EARLY NEXT WEEK. FORECAST
CHALLENGE IS TRYING TO DECIPHER BETWEEN THE DRY AND WET PERIODS.
LUCKILY ALL GUIDANCE IS SIMILAR IN HANDLING OF MAIN FEATURES THROUGH
THE PERIOD.
AGREE WITH PREVIOUS FORECAST THINKING AND ACTUALLY HAVE LOWERED POPS
EVEN MORE FOR FRIDAY FROM PREVIOUS FORECAST AS CONFIDENCE IS LOWER
IN MORE SUBSTANTIAL PRECIP COVERAGE. WINDS AND OVERALL FORCING ALOFT
WEAKEN AS HEIGHTS RISE AGAIN IN RESPONSE TO THE EXPANSION OF THE
UPPER RIDGE...WITH CONVECTIVE DEVELOPMENT LIKELY TO BE LARGELY
DEPENDENT ON AVAILABLE INSTABILITY. WILL AGAIN CARRY HIGHEST POPS
(30-40 PERCENT) OVER THE SOUTH/SOUTHEAST COUNTIES...DUE TO THEIR
CLOSES PROXIMITY TO DEPARTING UPPER WAVE. OTHERWISE ONLY ANTICIPATE
ISOLATED CONVECTION NORTH OF I-70.
THERE IS MORE SUBSTANTIAL POTENTIAL FOR CONVECTION LATER IN THE DAY
SATURDAY AS LOW PRESSURE PULLS OUT INTO THE CENTRAL PLAINS. GUIDANCE
SHOWS A STRONGER SHORT WAVE ALOFT OUT OF THE SOUTHERN PLAINS
REACHING THE REGION DURING THIS TIME. THIS FEATURE SHOULD SPURN
INCREASED CONVECTION...ESPECIALLY IF THE FEATURE ARRIVES DURING PEAK
HEATING IN THE LATE AFTERNOON. HAVE BUMPED UP POPS TO 40 PERCENT
SCATTERED DURING THE AFTERNOON AND EVENING AND LASTING THROUGH
SUNDAY. HEAVY RAIN AND LOCALIZED FLOODING MAY BECOME AN ISSUE WITH
PRECIP WATER VALUES AT OR ABOVE 1 INCH FOR MUCH OF THE PERIOD.
IN TERMS OF TEMPERATURES...POTENTIAL FOR RECORD BREAKING HIGHS AT
IND WILL CONTINUE THROUGH THE PERIOD. WITH NO APPRECIABLE CHANGE IN
THE AIRMASS...EXPECT HIGHS TO BE VERY SIMILAR FRIDAY THROUGH SUNDAY.
CONTINUING THE TREND OF RUNNING A FEW DEGREES ABOVE MOS AS HIGHS IN
THE UPPER 70S AND LOWER 80S ARE LIKELY THROUGH THE PERIOD. RECORD HIGHS
AT IND ARE 79 FROM 1945 ON FRIDAY AND 76 FROM 1894 ON SATURDAY.
AND 76 ON SUNDAY FROM 1903. LOWS WILL REMAIN NEAR 60 THROUGH THE
PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN KEEPING STRONG UPPER RIDGING
ACROSS THE AREA INTO THE MIDDLE OF NEXT WEEK. THERE ARE SOME
DIFFERENCES AMONG THE MEMBERS WITH RESPECT TO HOW FAR THE WESTERN
TROUGH WILL EJECT BY THE MIDDLE OF NEXT WEEK...BUT THE FASTEST
MEMBERS BRING THE TROUGH ONLY INTO THE ARKLATEX REGION BY NEXT
WEDNESDAY WHILE MOST OF THE OTHER MEMBERS KEEP THIS SYSTEM FARTHER
WEST OVER WESTERN TEXAS OR THE SOUTHERN ROCKIES. BOTTOM LINE IS THAT
IT APPEARS PRECIPITATION THREAT FOR EARLY NEXT WEEK CONTINUES TO
DIMINISH...WITH LITTLE ENSEMBLE SUPPORT FOR A POP BEYOND SUNDAY OR
MONDAY. WILL KEEP CHANCE POPS IN THE FORECAST FOR SUNDAY AND
MONDAY...AND GO DRY TUESDAY AND WEDNESDAY. MAY BE ABLE TO TAKE OUT
POPS FOR MONDAY AS WELL AT SOME POINT IN THE FUTURE IF DRIER TRENDS
CONTINUE. WELL ABOVE NORMAL TEMPERATURES WILL PERSIST THROUGHOUT
THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 151800Z TAF ISSUANCE/...
SOME WIND GUSTS OF AROUND 20 KTS OUT OF 220 COULD BE SEEN THIS
AFTERNOON ACCORDING TO RUC SOUNDINGS.
INSTABILITY IS INCREASING AT THE SITES AND RAPID UPDATE MODELS ARE
STILL SHOWING CONVECTIVE DEVELOPMENT ACROSS PARTS OF THE AREA BY
19Z. WILL USE THIS AS A START FOR THE INCLUSION OF VCTS BUT WILL NOT
DROP CATEGORY AT ANY SITE BESIDES KBMG AS NATURE OF CONVECTION WILL
BE POP UP AND SCATTERED. KBMG IS THE EXCEPTION TO THIS AS A LINE OF
STORMS ACROSS SOUTHERN ILLINOIS AT 1630Z IS HEADED TOWARD KBMG...AND
HAVE TIMED THIS LINE IN AND INCLUDED TEMPO THUNDER AND MVFR FOR A
COUPLE HOURS AROUND THE LINES ARRIVAL. CURRENT MOVEMENT AND TIMING
HAS THIS LINE MISSING THE REST OF THE SITES.
SHOULD SEE THIS ROUND OF CONVECTION MOVING OUT OF THE AREA BY AROUND
0-1Z. COULD SEE SOME ELEVATED ACTIVITY DEVELOP OVERNIGHT BUT THINK
LIKELIHOOD IS LOW ENOUGH TO LEAVE OUT. FORECAST SOUNDINGS DO SHOW A
STRONG INVERSION DEVELOPING OVERNIGHT AND HAVE CONCERNS THAT THIS
COULD LEAD TO LOWER VISIBILITIES...BUT WITH SOME CLOUD COVER...SOME
MIXING...AND CHANCES FOR PRECIP JUST DON/T FEEL CONFIDENT ENOUGH TO
GO LOWER THAN MVFR AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....JAS
AVIATION...CP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1245 PM EDT THU MAR 15 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
A BROAD UPPER LEVEL RIDGE WILL PERSIST ACROSS THE EASTERN PART OF
THE COUNTRY INTO THE MIDDLE OF NEXT WEEK...WITH TEMPERATURES
CONTINUING AT WELL ABOVE NORMAL AND NEAR RECORD LEVELS. SEVERAL
DISTURBANCES ALOFT WILL PROGRESS THROUGH THE UPPER RIDGE...PROVIDING
PERIODIC CHANCES FOR THUNDERSTORMS OVER CENTRAL INDIANA THROUGH THE
WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
AS OF 1030AM...THE EARLY POCKETS OF CONVECTION (ASSOCIATED WITH AN
UPPER WAVE) HAVE SINCE MOVED EAST/SOUTHEAST AND OUT OF THE CWA.
OUR EYES THEN TURN TO THIS AFTERNOON AND EVENING AS A VORT MAX
CURRENTLY LOCATED OVER LOWER MO AND SW IL MOVES EASTWARD TOWARD THE
OH VALLEY. SCATTERED CONVECTION LIKELY TO DEVELOP INTO THE FORECAST
AREA AS THE DAY PROGRESSES AS THE ENTIRE OHIO VALLEY REMAINS UNDER A
MOIST AND UNSTABLE AIRMASS. THE PRESENCE OF A WEAK FRONTAL BOUNDARY
TO THE NORTH WILL LIKELY HAVE SOME INFLUENCE ON CONVECTION BUT STILL
APPEARS THE UPPER LEVEL DISTURBANCE WILL BE THE MAIN DRIVING
FEATURE RESPONSIBLE FOR INDUCING CONVECTION OVER THE CWA AND THE
OHIO VALLEY BY THE AFTERNOON.
EVEN THOUGH THE SLIGHT RISK HAS BEEN EXPANDED FARTHER NORTHWARD
WITH SPC/S MORNING UPDATE...CONVECTION SHOULD BE ESPECIALLY
FOCUSED OVER THE SOUTHERN HALF OF THE FORECAST AREA AS THE DISTURBANCE
TRACKS INTO THE SRN OHIO VALLEY THROUGH THIS EVENING. WILL
CONTINUE TO CARRY SCATTERED TSTMS IN THE FORECAST BUT ADDED THE
THREAT OF SVR WX (FOR THE SLIGHT RISK AREA) INCLUDING LARGE HAIL
AND VERY HEAVY RAINFALL AS THE MAIN THREATS. WITH BL SHEAR VALUES
REMAINING WEAK..STORMS SHOULD REMAIN LARGELY SUBSEVERE AND DEVELOP
INTO MULTICELLULAR CLUSTERS WITH BRIEF HEAVY RAINERS. HOWEVER WITH
WBZERO VALUES NEAR 8KFT AND STEEP LAPSE RATES PRESENT...A FEW OF
THE MORE INTENSE STORMS WILL BE CAPABLE OF PRODUCING HAIL AND
POSSIBLY SOME GUSTY WINDS.
TEMPS...THE WARM START THIS MORNING AND EXPECTATION FOR SUNSHINE
THROUGH MIDDAY WILL ONCE AGAIN ENABLE TEMPS TO RISE TO AROUND 80
DEGREES THIS AFTERNOON. POTENTIAL FOR MORE CLOUDS AND PRECIP BY THIS
AFTERNOON IN SOUTHERN COUNTIES MAY HAMPER RISES A BIT...BUT
OTHERWISE SEE NO REASON TO GO A FEW DEGREES ABOVE MOS ONCE AGAIN.
STRONG POSSIBILITY THAT RECORD HIGH OF 77 FROM 1977 AT IND IS
REACHED AGAIN TODAY.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES AND TEMPS AS UPPER LEVEL
DISTURBANCES CONTINUE TO TRACK THROUGH THE OHIO VALLEY IN BROAD
SOUTHWEST FLOW REGIME. ALL GUIDANCE IS SIMILAR IN HANDLING OF MAIN
FEATURES THROUGH THE PERIOD.
SCATTERED CONVECTION WILL CONTINUE THIS EVENING AS AFOREMENTIONED
UPPER WAVE DRIFTS EAST THROUGH THE OHIO VALLEY. FOCUS FOR HIGHEST
POPS WILL REMAIN SOUTH OF I-70 THROUGH THE EVENING HOURS...LOWERING
AFTER MIDNIGHT AS WEAK RIDGING ALOFT BUILDS BACK INTO THE REGION
BEHIND THE FEATURE. HAVE LOWERED POPS FOR FRIDAY FROM PREVIOUS
FORECAST AS CONFIDENCE IS LOWER IN MORE SUBSTANTIAL PRECIP COVERAGE.
WINDS AND OVERALL FORCING ALOFT WEAKEN AS HEIGHTS RISE AGAIN IN
RESPONSE TO THE EXPANSION OF THE UPPER RIDGE...WITH CONVECTIVE
DEVELOPMENT LIKELY TO BE LARGELY DEPENDENT ON AVAILABLE INSTABILITY.
WILL ONCE AGAIN CARRY HIGHEST 30-40 POPS OVER SOUTHEAST COUNTIES IN
CLOSEST PROXIMITY TO DEPARTING UPPER WAVE. OTHERWISE...ANTICIPATE
ONLY ISOLATED CONVECTION.
POTENTIAL FOR MORE SUBSTANTIAL CONVECTIVE COVERAGE ON SATURDAY AS
LOW PRESSURE PULLS OUT INTO THE CENTRAL PLAINS. MODEL GUIDANCE
CONSISTENT IN BRINGING A STRONGER SHORT WAVE ALOFT OUT OF THE
SOUTHERN PLAINS AND INTO THE REGION BY SATURDAY AFTERNOON AND
EVENING. THIS FEATURE SHOULD SPURN INCREASED CONVECTION...ESPECIALLY
IF THE FEATURE ARRIVES DURING PEAK HEATING IN THE LATE AFTERNOON.
HAVE BUMPED UP POPS DURING THE AFTERNOON AND EVENING. HEAVY RAIN AND
LOCALIZED FLOODING MAY BECOME AN ISSUE WITH PRECIP WATER VALUES AT
OR ABOVE 1 INCH FOR MUCH OF THE PERIOD.
TEMPS...POTENTIAL FOR RECORD BREAKING HIGHS AT IND WILL CONTINUE
THROUGH THE PERIOD. WITH NO APPRECIABLE CHANGE IN THE AIRMASS...
EXPECT HIGHS TO BE VERY SIMILAR FRIDAY AND SATURDAY. CONTINUING THE
TREND OF RUNNING A FEW DEGREES ABOVE MOS AS HIGHS IN THE UPPER 70S
AND LOWER 80S ARE LIKELY BOTH DAYS. RECORD HIGHS AT IND ARE 79 FROM
1945 ON FRIDAY AND 76 FROM 1894 ON SATURDAY. LOWS WILL REMAIN NEAR
60 THROUGH THE PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ENSEMBLES IN GENERAL AGREEMENT IN KEEPING STRONG UPPER RIDGING
ACROSS THE AREA INTO THE MIDDLE OF NEXT WEEK. THERE ARE SOME
DIFFERENCES AMONG THE MEMBERS WITH RESPECT TO HOW FAR THE WESTERN
TROUGH WILL EJECT BY THE MIDDLE OF NEXT WEEK...BUT THE FASTEST
MEMBERS BRING THE TROUGH ONLY INTO THE ARKLATEX REGION BY NEXT
WEDNESDAY WHILE MOST OF THE OTHER MEMBERS KEEP THIS SYSTEM FARTHER
WEST OVER WESTERN TEXAS OR THE SOUTHERN ROCKIES. BOTTOM LINE IS THAT
IT APPEARS PRECIPITATION THREAT FOR EARLY NEXT WEEK CONTINUES TO
DIMINISH...WITH LITTLE ENSEMBLE SUPPORT FOR A POP BEYOND SUNDAY OR
MONDAY. WILL KEEP CHANCE POPS IN THE FORECAST FOR SUNDAY AND
MONDAY...AND GO DRY TUESDAY AND WEDNESDAY. MAY BE ABLE TO TAKE OUT
POPS FOR MONDAY AS WELL AT SOME POINT IN THE FUTURE IF DRIER TRENDS
CONTINUE. WELL ABOVE NORMAL TEMPERATURES WILL PERSIST THROUGHOUT
THE EXTENDED.
&&
.AVIATION /DISCUSSION FOR 151800Z TAF ISSUANCE/...
SOME WIND GUSTS OF AROUND 20 KTS OUT OF 220 COULD BE SEEN THIS
AFTERNOON ACCORDING TO RUC SOUNDINGS.
INSTABILITY IS INCREASING AT THE SITES AND RAPID UPDATE MODELS ARE
STILL SHOWING CONVECTIVE DEVELOPMENT ACROSS PARTS OF THE AREA BY
19Z. WILL USE THIS AS A START FOR THE INCLUSION OF VCTS BUT WILL NOT
DROP CATEGORY AT ANY SITE BESIDES KBMG AS NATURE OF CONVECTION WILL
BE POP UP AND SCATTERED. KBMG IS THE EXCEPTION TO THIS AS A LINE OF
STORMS ACROSS SOUTHERN ILLINOIS AT 1630Z IS HEADED TOWARD KBMG...AND
HAVE TIMED THIS LINE IN AND INCLUDED TEMPO THUNDER AND MVFR FOR A
COUPLE HOURS AROUND THE LINES ARRIVAL. CURRENT MOVEMENT AND TIMING
HAS THIS LINE MISSING THE REST OF THE SITES.
SHOULD SEE THIS ROUND OF CONVECTION MOVING OUT OF THE AREA BY AROUND
0-1Z. COULD SEE SOME ELEVATED ACTIVITY DEVELOP OVERNIGHT BUT THINK
LIKELIHOOD IS LOW ENOUGH TO LEAVE OUT. FORECAST SOUNDINGS DO SHOW A
STRONG INVERSION DEVELOPING OVERNIGHT AND HAVE CONCERNS THAT THIS
COULD LEAD TO LOWER VISIBILITIES...BUT WITH SOME CLOUD COVER...SOME
MIXING...AND CHANCES FOR PRECIP JUST DON/T FEEL CONFIDENT ENOUGH TO
GO LOWER THAN MVFR AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/SMF
SHORT TERM...RYAN
LONG TERM....JAS
AVIATION...CP
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
307 PM EDT THU MAR 15 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM, MOVING SLOWLY EAST THROUGH THE GREAT LAKES,
WILL PROVIDE SHOWERS AND SCATTERED THUNDERSTORMS INTO FRIDAY
NIGHT. HIGH PRESSURE WILL FOLLOW WITH DRY CONDITIONS SATURDAY AS
TEMPERATURES WILL REMAIN UNSEASONABLY WARM INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
MODEL GUIDANCE CONTINUES TO DIVERGE ON THE EXTENT OF SHOWERS AND
THUNDERSTORMS ACROSS THE UPPER OHIO VALLEY TONIGHT INTO FRIDAY.
RECENT RADAR DATA AND HRRR MODEL OUTPUT CONTINUES TO SHOW NO MORE
THAN ISOLATED SHOWERS ACROSS THE AREA INTO EARLY EVENING. RECENT
SREF MODEL OUTPUT, SOMEWHAT SUPPORTED BY RECENT HRRR AND WRF-ARW
MODEL OUTPUT, SUGGEST A BAND OF NUMEROUS SHOWERS AND SCATTERED
THUNDERSTORMS MOVING EASTWARD THROUGH THE UPPER OHIO VALLEY LATE
THIS EVENING AND OVERNIGHT.
DESPITE SPC CONTINUING A SLIGHT RISK ACROSS OHIO WEST OF THE I-77
CORRIDOR, HAVE LOW CONFIDENCE IN SEVERE DEVELOPMENT, AS RECENT
SREF MODEL OUTPUT SHOWS WEAK INSTABILITY AND VERTICAL WIND SHEAR
TONIGHT.
FOR CONTINUITY, CONTINUED A CHANCE OF SHOWERS AND THUNDERSTORMS
FRIDAY AS MOST SREF MEMBERS SHOW THE BAND OF SHOWERS HAVING EXITED
BY MORNING, AND UPPER LEVEL RIDGING ACROSS THE EASTERN U.S.
INCREASING.
FORECASTED TEMPERATURES BASED ON BLEND OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
A SERIES OF SHORTWAVES MOVING ACROSS AN UPPER LEVEL RIDGE OVER THE
EAST COAST WILL PROVIDE UNSETTLED WEATHER THROUGH THE WEEKEND.
HAVE GONE WITH SLIGHT CHANCE OF THUNDERSTORMS ON SATURDAY AND
CHANCE ON SUNDAY. INCONSISTENCY STILL EXISTS BETWEEN THE NAM AND
GFS FOR THUNDERSTORMS.
TREND OF WELL ABOVE NORMAL TEMPERATURES CONTINUES INTO NEXT WEEK.
RECORD HIGH TEMPERATURES COULD BE SET IN AREAS AROUND PITTSBURGH
AND SOUTH WITH TEMPERATURES REACHING THE UPPER 70S. CURRENT RECORD
HIGHS FOR SPECIFIC SITES ARE LISTED IN THE CLIMATE SECTION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WEAK TROF MOVING ACROSS SOUTHERN LAKES COULD TRIGGER SCATTERED
SHOWERS OR THUNDERSTORMS FROM LATE SUNDAY THROUGH MONDAY MORNING.
GFS MAINTAINS CONSIDERABLY STRONGER SHORT WAVE THAN OTHER MODELS. AN
UPPER RIDGE WILL AMPLIFY ACROSS THE EASTERN STATES EARLY NEXT WEEK
AND REMAIN IN PLACE THROUGH WEDNESDAY. SURFACE HIGH PRESSURE IS
PROGGED TO HOLD ALONG THE MID ATLANTIC COAST AND MAINTAIN SOUTHWEST
FLOW ACROSS THE UPPER OHIO VALLEY REGION.
MUCH ABOVE NORMAL TEMPERATURES THROUGHOUT THE PERIOD WITH
TEMPERATURES AVERAGING NEARLY 20 DEGREES PER DAY ABOVE NORMAL.
NEXT FRONT APPROACHES UPPER OHIO RIVER VALLEY ON FRIDAY.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
GENERAL VFR CONDITIONS WILL PREVAIL THROUGH 16/06Z. WEAK FRONT
LOCATED ACROSS SOUTHERN GREAT LAKES WILL MOVE ACROSS REGION LATE
TONIGHT AND POSSIBLY TRIGGER SHOWERS AND SOME THUNDERSTORMS WITH
MVFR VSBY THROUGH 14Z.
AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY OVER SOUTHERN OHIO AND
MOVING INTO WEST VIRGINA WILL STAY SOUTH OF CWA. APPEARS THIS
FEATURE IS TRAPPING MOST OF THE AVAILABLE MOISTURE AND WILL KEEP
LATE AFTERNOON AND EVENING CONVECTION AT A MINIMUM ACROSS CWA.
EXPECT VFR CONDITIONS FROM FRIDAY AFTERNOON THROUGH SUNDAY WITH WEAK
HIGH PRESSURE OVER REGION.
OUTLOOK...SUNDAY NIGHT THROUGH TUESDAY...
WEAK UPPER TROF MOVING THROUGH SOUTHERN GREAT LAKES LATE SUNDAY AND
SUNDAY NIGHT MAY TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS WITH
BEST CHANCE OF RESTRICTIONS ACROSS NORTHERN PA.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES FOR MARCH 17.
PITTSBURGH PA 73 SET IN 1945.
ZANESVILLE OH 74 SET IN 1989.
MORGANTOWN WV 75 SET IN 1989.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
257 PM EDT THU MAR 15 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM, MOVING SLOWLY EAST THROUGH THE GREAT LAKES,
WILL PROVIDE SHOWERS AND SCATTERED THUNDERSTORMS INTO FRIDAY
NIGHT. HIGH PRESSURE WILL FOLLOW WITH DRY CONDITIONS SATURDAY AS
TEMPERATURES WILL REMAIN UNSEASONABLY WARM INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
MODEL GUIDANCE CONTINUES TO DIVERGE ON THE EXTENT OF SHOWERS AND
THUNDERSTORMS ACROSS THE UPPER OHIO VALLEY TONIGHT INTO FRIDAY.
RECENT RADAR DATA AND HRRR MODEL OUTPUT CONTINUES TO SHOW NO MORE
THAN ISOLATED SHOWERS ACROSS THE AREA INTO EARLY EVENING. RECENT
SREF MODEL OUTPUT, SOMEWHAT SUPPORTED BY RECENT HRRR AND WRF-ARW
MODEL OUTPUT, SUGGEST A BAND OF NUMEROUS SHOWERS AND SCATTERED
THUNDERSTORMS MOVING EASTWARD THROUGH THE UPPER OHIO VALLEY LATE
THIS EVENING AND OVERNIGHT.
DESPITE SPC CONTINUING A SLIGHT RISK ACROSS OHIO WEST OF THE I-77
CORRIDOR, HAVE LOW CONFIDENCE IN SEVERE DEVELOPMENT, AS RECENT
SREF MODEL OUTPUT SHOWS WEAK INSTABILITY AND VERTICAL WIND SHEAR
TONIGHT.
FOR CONTINUITY, CONTINUED A CHANCE OF SHOWERS AND THUNDERSTORMS
FRIDAY AS MOST SREF MEMBERS SHOW THE BAND OF SHOWERS HAVING EXITED
BY MORNING, AND UPPER LEVEL RIDGING ACROSS THE EASTERN U.S.
INCREASING.
FORECASTED TEMPERATURES BASED ON BLEND OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
A SERIES OF SHORTWAVES MOVING ACROSS AN UPPER LEVEL RIDGE OVER THE
EAST COAST WILL PROVIDE UNSETTLED WEATHER THROUGH THE WEEKEND.
HAVE GONE WITH SLIGHT CHANCE OF THUNDERSTORMS ON SATURDAY AND
CHANCE ON SUNDAY. INCONSISTENCY STILL EXISTS BETWEEN THE NAM AND
GFS FOR THUNDERSTORMS.
TREND OF WELL ABOVE NORMAL TEMPERATURES CONTINUES INTO NEXT WEEK.
RECORD HIGH TEMPERATURES COULD BE SET IN AREAS AROUND PITTSBURGH
AND SOUTH WITH TEMPERATURES REACHING THE UPPER 70S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WEAK TROF MOVING ACROSS SOUTHERN LAKES COULD TRIGGER SCATTERED
SHOWERS OR THUNDERSTORMS FROM LATE SUNDAY THROUGH MONDAY MORNING.
GFS MAINTAINS CONSIDERABLY STRONGER SHORT WAVE THAN OTHER MODELS. AN
UPPER RIDGE WILL AMPLIFY ACROSS THE EASTERN STATES EARLY NEXT WEEK
AND REMAIN IN PLACE THROUGH WEDNESDAY. SURFACE HIGH PRESSURE IS
PROGGED TO HOLD ALONG THE MID ATLANTIC COAST AND MAINTAIN SOUTHWEST
FLOW ACROSS THE UPPER OHIO VALLEY REGION.
MUCH ABOVE NORMAL TEMPERATURES THROUGHOUT THE PERIOD WITH
TEMPERATURES AVERAGING NEARLY 20 DEGREES PER DAY ABOVE NORMAL.
NEXT FRONT APPROACHES UPPER OHIO RIVER VALLEY ON FRIDAY.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
GENERAL VFR CONDITIONS WILL PREVAIL THROUGH 16/06Z. WEAK FRONT
LOCATED ACROSS SOUTHERN GREAT LAKES WILL MOVE ACROSS REGION LATE
TONIGHT AND POSSIBLY TRIGGER SHOWERS AND SOME THUNDERSTORMS WITH
MVFR VSBY THROUGH 14Z.
AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY OVER SOUTHERN OHIO AND
MOVING INTO WEST VIRGINA WILL STAY SOUTH OF CWA. APPEARS THIS
FEATURE IS TRAPPING MOST OF THE AVAILABLE MOISTURE AND WILL KEEP
LATE AFTERNOON AND EVENING CONVECTION AT A MINIMUM ACROSS CWA.
EXPECT VFR CONDITIONS FROM FRIDAY AFTERNOON THROUGH SUNDAY WITH WEAK
HIGH PRESSURE OVER REGION.
OUTLOOK...SUNDAY NIGHT THROUGH TUESDAY...
WEAK UPPER TROF MOVING THROUGH SOUTHERN GREAT LAKES LATE SUNDAY AND
SUNDAY NIGHT MAY TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS WITH
BEST CHANCE OF RESTRICTIONS ACROSS NORTHERN PA.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 PM EDT THU MAR 15 2012
.SYNOPSIS...
ISSUED AT 405 AM EDT THU MAR 15 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A WSW FLOW ALF FM
THE PAC NW TO ONTARIO BTWN UPR RDG MOVING SLOWLY E THRU THE GREAT
LKS AND A LARGER SCALE TROF OFF THE W COAST. SFC COOL FNT ATTENDANT
TO STRONG SHRTWV LIFTING NEWD THRU HUDSON BAY IS MOVING E THRU UPR
MI EARLY THIS MRNG AND WL BRING AT LEAST A TEMPORARY END TO RECORD
WARMTH THAT ENVELOPED THE AREA ON WED...WHEN THE MERCURY PEAKED IN
THE 70S AT MANY SPOTS AND AS HI AS 77 AT KENTON. THERE WAS A SURGE
OF LLVL MSTR MOVING NEWD AHEAD OF THIS COOL FNT...AND SOME FOG AND
SC HAVE DVLPD OVER THE SE HALF OF THE CWA AHEAD OF THE COOL FNT.
ALTHOUGH THE 00Z GRB RAOB SHOWS STEEP H8-5 LAPSE RATES NOT FAR FM
DRY ADIABATIC...THE DRYNESS OF THE MID LVLS AND A SHARP INVRN NEAR
H8 THAT HAS CAPPED THE LLVL MOISTENING/DESTABILIZATION AND HELD IN
THE ABSENCE OF ANY DYNAMIC SUPPORT SO FAR S OF THE HUDSON BAY SHRTWV
HAVE CONSPIRED TO PREVENT THE DEVELOPMENT OF ANY SHRA/TS. BEHIND THE
FNT...HI PRES IN THE NRN PLAINS IS TENDING TO BUILD TO THE ENE. THE
00Z INL RAOB DEPICTS A VERY DRY LOWER TROP WITH H925/H85 DEWPT
DEPRESSIONS OF 18C/22C. SFC DEWPTS HAVE FALLEN INTO THE TEENS OVER
THE N HALF OF MN. ALTHOUGH THE COOL FNT PASSED IWD/CMX IN THE EARLY
EVNG...SFC DEWPTS THERE ARE STILL IN THE MID 30S. OVER THE S HALF OF
MN...SFC DEWPTS REMAIN AS HI AS 45 EVEN BEHIND THE FROPA. BUT EXCEPT
FOR SOME HI CLDS...SKIES ARE MOCLR AS THE 00Z MPX RAOB IS QUITE DRY
IN A RELATIVE SENSE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
TDAY...MAIN FCST CONCERNS IN THE SHORT TERM RELATE TO THE EXTENT OF
THE LLVL DRYING THAT WL OCCUR OVER THE CWA IN THE WAKE OF THE COOL
FNT THAT IS FCST TO CLEAR THE SE ZNS BY FCST ISSUANCE. MODELS IN
RECENT DAYS HAVE SHOWN SOME DISAGREEMENT ON THIS DRYING BECAUSE THE
FLOW ALF IS EXPECTED TO REMAIN WSW AND TAKE THE SFC HI PRES/CORE OF
THE REALLY DRY AIR NOW IN NW MN INTO ONTARIO. BUT EVEN IF THE LLVL
AIRMASS MOVING INTO UPR MI COMES FM THE DIRECTION OF MPX...THE
RELATIVE DRYNESS OF THE AIRMASS THERE IS A GOOD INDICATION LO CLDS
ARE LESS LIKELY TO DEVELOP THAN PREVIOUSLY FCST. WITH THE EXCEPTION
OF THE GFS...THE 00Z RUNS HAVE COME INTO GOOD AGREEMENT SHOWING MORE
DRYING IN THE H95-9 LYR THRU THE DAY. GIVEN THE DRYNESS/LACK OF CLDS
UPSTREAM AND DIFFLUENT NATURE OF THE FLOW...WL FOLLOW THE 00Z LOCAL
WRF-ARW THAT INDICATES MORE AGGRESSIVE LLVL DRYING AND CUT BACK ON
THE EXTENT OF THE LO CLDS. THIS MODEL DOES INDICATE SOME LO CLDS MAY
LINGER OVER THE E THIS MRNG IN THE WAKE OF THE FROPA...BUT OTRW
INDICATES THE DAY SHOULD BE MOSUNNY EXCEPT FOR SOME HI CLDS. MIXING
TO H85 ON WRF-ARW SDNGS INDICATES HI TEMPS WL TOP OUT ARND 60 OVER
LOCATIONS NEAR THE WI BORDER WELL INLAND FM LK SUP COOLING IN THE
LLVL N-NE FLOW. HI TEMPS ARE LIKELY TO HOLD IN THE 40S NEAR LK SUP E
OF THE KEWEENAW WITH ONSHORE 15KT NE H925 WINDS.
TNGT...ALTHOUGH A WEAK SHRTWV IS PROGGED TO RIPPLE THRU THE UPR
FLOW...THE MID LVLS ARE TOO DRY FOR ANY PCPN. IN FACT...FCST
SOUNDINGS INDICATE ONLY SOME HI CLDS. EXPECT A HEALTHY DIURNAL TEMP
FALL WITH LIGHT WINDS. THE LOWEST MIN TEMPS ARE LIKELY OVER THE
INTERIOR E AND CNTRL WHERE THE WINDS WL BE LIGHTEST THRU THE NGT.
INCRSG S WIND LATER AS HI PRES RDG BEGINS TO RETREAT TO THE E WL
LIKELY KEEP TEMPS A BIT ELEVATED OVER THE FAR W FM IWD TO ONTONAGON.
THE LOCAL WRF-ARW FCST SDNGS INDICATE THE BEST CHC FOR FOG WL BE
OVER THE E...WHERE A BIT MORE AMPLE LLVL MSTR WL COINCIDE WITH THE
LGT WINDS.
FRI...SFC HI CENTER IS FCST TO DRIFT INTO QUEBEC...WITH INCRSG SLY
FLOW UNDER SHARPENING PRES GRADIENT BTWN THE DEPARTING HI AND
FALLING PRES IN THE PLAINS. THE RETURN OF HIER H95-9 SPECIFIC
HUMIDITY WL RESULT IN SOME AFTN CU/SC. WITH H85 TEMPS FCST TO
REBOUND TO ARND 12C...TEMPS WL REBOUND INTO THE 60S AWAY FM LK
MODERATION...WARMEST OVER THE W WHERE THE SSE SFC FLOW DOWNSLOPES.
FRI NGT...SSW H925 WINDS INCRSG UP TO 25-35 KTS ON THE WRN FLANK OF
RETREATING HI PRES ARE FCST TO BRING MORE LLVL MSTR SURGING INTO THE
UPR LKS. ALTHOUGH MODELS GENERATE SPOTTY QPF...GFS FCST SDNGS SHOW
CAPPING INVRN LINGERING BTWN H8-75 IN THE ABSENCE OF ANY DYNAMIC
SUPPORT WITHIN UPR RDG AXIS. SO OPTED TO KEEP GOING DRY FCST. SOME
FOG IS LIKELY OVER THE E IN AREAS DOWNWIND OF LK MI EVEN THOUGH THE
STRONG WINDS/LLVL MOISTENING WL RETARD THE DIURNAL FALL OF TEMP.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 405 AM EDT THU MAR 15 2012
UPPER RIDGE WILL BE IN CONTROL OF THE REGION AT THE START OF THE
PERIOD AND CONTINUE THROUGH THE FIRST HALF OF NEXT WEEK.
AT THE SFC...AREA WILL BE BETWEEN A COLD FRONT OVER THE ERN DAKOTAS
AND SFC HIGH MOVING E INTO THE NEW ENGLAND STATES. THIS WILL ALLOW
SRLY FLOW TO BE IN PLACE AND MODELS SHOWING GOOD H950-850 MOISTURE
SURGING NNE OVER THE AREA FRI NIGHT AND INTO SAT. IF THIS MOISTURE
IS PRESENT AND LOW CLOUDS FORM...COULD BE DIFFICULT TO BREAK OUT ON
SATURDAY IF THIS OCCURS. BUT LATEST TRENDS IN NAM/GFS ARE SHOWING
MORE MIXING PRESENT AND FEEL A PARTLY CLOUDY FORECAST IS WARRENTED
FOR ALL BUT NEAR LK MI...WHERE FOG ON SAT MORNING WILL KEEP THINGS
MOSTLY CLOUDY. THIS MAKES TEMPS TRICKY...AS IT WILL DEPEND ON THE
CLOUDS BREAKING OUT. THINK THE WEST HALF HAS A BETTER CHANCE OF THIS
OCCURRING AND TRENDED TOWARDS THE WARM SIDE. MIXING TO H900 WOULD
GIVE HIGHS NEAR 70S AND HAVE FOLLOWED THAT. DEPENDING ON THE WIND
DIRECTION...WHICH IS TRENDING A LITTLE SSW...SO TRENDED TEMPS UP
THERE SLIGHTLY DUE TO DOWNSLOPE WINDS.
ONE FINAL THING OF NOTE IS THE NAM IS SHOWING DECENT
INSTABILITY...2K J/KG OF CAPE...IN THE AFTN WITH THE STRONG DIURNAL
HEATING OVER THE W HALF. OPTED TO REMAIN DRY EVEN WITH THIS
INSTABILITY POTENTIAL...BUT WILL NEED TO MONITOR.
WEAK UPPER LEVEL DISTURBANCE SATURDAY NIGHT AND SUNDAY LOOKS TO STAY
S OF THE CWA. COULD SEE SOME SHOWERS DEVELOPING WITH THIS WEEK
DISTURBANCE OVER CNTRL LK MI AND LOWER MI. MAIN FEATURE OF NOTE TO
AFFECT THE CWA IS A DECAYING COLD FRONT DROPPING OVER LK SUPERIOR
SAT NIGHT. WILL PUSH N ON SUNDAY AS A WARM FRONT AS LOW PRESSURE
ORGANIZES OVER THE NRN PLAINS. QUESTION IS HOW FAR S IT WILL SINK
BEFORE PUSHING BACK N. GFS/ECMWF/GEM STALL IT OVER LK SUPERIOR AND
MAYBE REACHING THE KEWEENAW PENINSULA. NAM TRIES TO PUSH IT A TOUCH
FARTHER S AND DEVELOP PCPN OVER MUCH OF UPPER MI. FINDING IT HARD TO
BUCK THE MODEL CONSENSUS...ESPECIALLY THAT FAR OUT ON THE NAM...SO
WILL CONFINE THE CHANCE POPS OVER LK SUPERIOR AND LK MI AND KEEP
SLIGHTS IN BETWEEN.
EXTENDED /SUNDAY NIGHT THROUGH WEDNESDAY/...
ANOMALOUS H500 HEIGHTS...AROUND 2-3 STD DEV ABOVE NORMAL FOR
MID-LATE MARCH WILL REMAIN OVER THE AREA FOR THE EXTENDED PERIOD.
TROUGH OVER AMPLIFYING AND MOVING OVER THE SW CONUS WILL AMPLIFY THE
RIDGE UPSTREAM AND LEAD TO CONTINUED WARMING UNDER SRLY FLOW KEEPING
WARM AIR IN PLACE.
WITH THE SRLY FLOW...MODELS CONTINUE TO SURGE WARM/MOIST AIR OVER
THE AREA. THIS MAKES FOR A TROUBLING FORECAST...AS IT IS LARGELY
DEPENDENT ON IF LOW CLOUDS DEVELOP BELOW THE PERSISTANT H850
INVERSION. IF THE LAST 12HRS ARE ANY INDICATION...PRODUCES SOME
DOUBT TO NORTHWARD EXTENT. BUT THE PERSISTANT SRLY FLOW WILL LIKELY
PUSH THE MOISTURE INTO THE AREA AND SHOULD LEAD TO MORE
CLOUDY/FOGGY NIGHTS WHICH WILL BREAK UP DUE TO DIURNAL HEATING.
ADDED FOG OVER LK SUPERIOR/MICHIGAN THROUGH THE EXTENDED AND BLED
IT INLAND NEAR LK MI DURING THE OVERNIGHT HOURS WITH THE SSE WINDS.
TEMPS WILL GREATLY DEPEND ON LOW CLOUDS/FOG AND DAYTIME MIXING...BUT
WILL CONTINUE TO BE WELL ABOVE NORMAL WITH MANY DAYS IN THE 60S
OVER THE WEST. COOLER VALUES OVER THE E AND ALSO PORTIONS OF THE
NCNTRL...DUE TO SSE WINDS THROUGH MUCH OF THE PERIOD.
AS FOR PCPN...MODELS CONTINUING TO SHOW LIGHT QPF ALONG AND OVER
THE GREAT LKS. WHAT IS LIKELY HAPPENING IS THAT THE ABUNDANT
MOISTURE IS TOO MUCH IN THE LOW LEVELS AND THE MODELS ARE TRYING TO
RELIEVE THEMSELVES OF THIS EXCESS MOISTURE. WILL LIKELY BE FOG IN
THESE AREAS DUE TO THE MOIST AIR OVER THE COOL GREAT LKS...BUT
DON/T SEE MUCH CHANCES FOR SHOWERS WITH THE STRONG H850 CAP. IF
ANYTHING...A FOG/DZ COMBINATION WOULD OCCUR. THUS...HAVE REMOVED
MUCH OF THE SLIGHT CHANCES FROM SUN NIGHT ON.
MODELS SHOWING THE UPPER RIDGE STARTING TO SHIFT E AS THE UPPER
TROUGH STARTS TO BECOME CUT OFF ON WED. HOW THIS LOW EVOLVES WILL
AFFECT THE FORECAST FOR THE END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 137 PM EDT THU MAR 15 2012
EXPECT VFR CONDITIONS INTO FRIDAY WITH LIGHT WINDS...SCT-BKN MID-HIGH
LEVEL CLOUDINESS AND NO RESTRICTION TO VSBY. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 AM EDT THU MAR 15 2012
EXPECT WINDS TO BE MOSTLY UNDER 20 KTS THROUGH THIS WEEKEND AS A
RELATIVELY WEAK PRES GRADIENT DOMINATES. ALTHOUGH A SHARPER PRES
GRADIENT/STRONGER S FLOW WILL DEVELOP OVER THE WEEKEND...THE
UNSEASONABLY WARM AIR OVER THE UPPER GREAT LAKES WILL ALSO RESULT IN
PERSISTENT MARINE LAYER/STRONG STABILITY OVER THE LAKE...HELPING TO
KEEP SURFACE WINDS ON THE LIGHTER SIDE. AT SOME POINT...FOG MAY
BECOME AN ISSUE...ESPECIALLY IF SOME RAINFALL OCCURS OVER THE LAKE.
RIGHT NOW...IT APPEARS DRY WEATHER SHOULD GENERALLY DOMINATE...
KEEPING FOG POTENTIAL LIMITED.
&&
.HYDROLOGY...
ISSUED AT 405 AM EDT THU MAR 15 2012
WELL ABOVE NORMAL TEMPERATURES OVER THE LAST SEVERAL DAYS...
ESPECIALLY ON WED...ALONG WITH RAIN OF 0.10 TO MORE THAN 0.5 INCH ON
MON HAS LED TO INCREASED SNOWMELT/RUNOFF. THIS RUNOFF HAS PRODUCED
SOME RISE IN LEVELS OF RIVERS IN UPR MI OVER THE LAST COUPLE OF DAYS.
ABOVE NORMAL TEMPERATURES INTO NEXT WEEK WILL CONTINUE TO MELT THE
SNOW PACK AND LEAD TO FURTHER INCREASES IN RIVER AND STREAM LEVELS.
ALTHOUGH A COOLER/DRIER AIRMASS WILL ARRIVE TODAY AND SLOW THE
MELTING...EXPECT SOME OF THE RIVERS ACROSS THE AREA TO EXCEED THEIR
BANKS BY THE END OF THIS WEEK. FORTUNATELY...THE LACK OF ANY
SIGNIFICANT RAIN IN THE FORECAST FOR THE NEXT WEEK WILL LOWER THE
CHANCE OF SIGNIFICANT FLOODING. BUT PERSONS LIVING NEAR RIVERS AND
STREAMS SHOULD MONITOR THE LATEST RIVER CONDITIONS AND USE CAUTION IF
WALKING ALONG RIVER BANKS...ESPECIALLY THE CHOCOLAY RIVER...TRAP ROCK
RIVER...AND THE STURGEON RIVER IN WESTERN UPPER MICHIGAN.
DID HAVE AN APPARENT ICE JAM ON THE ONTONAGON RIVER NEAR ROCKLAND
MON EVENING. THIS CAUSED THE RIVER LEVELS TO RISE 4FT BEFORE IT
BROKE FREE. WILL NEED TO MONITOR CONDITIONS ALONG THE ONTONAGON
RIVER OVER THE NEXT DAY OR TWO...AS THE NUMEROUS BENDS COULD CAUSE
THE ICE TO FORM ANOTHER JAM. IN ADDITION...ICE WAS REPORTED ON THE
FORD RIVER AT HYDE AND THE MOUTH AT LK MI. DEPENDING ON THE BREAKUP
OF THE ICE...THERE IS A POTENTIAL FOR MORE ICE JAMS INTO THIS
WEEKEND...WHEN THE RIVER ICE MAY CLEAR COMPLETELY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...SRF
AVIATION...JLA
MARINE...KC
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
329 PM CDT THU MAR 15 2012
.SHORT TERM...
ISSUED AT 325 PM CDT THU MAR 15 2012
(TONIGHT)
MAIN CONVECTIVE THREAT SHOULD BE THIS EVENING...AND PRIMARILY OVER
S SECTIONS OF THE CWA...ALONG AND AHEAD OF BLOSSOMING CONVECTION
ACROSS THE OZARKS. MEANWHILE...HAVE CONTINUED CHANCE POPS OVER N
SECTIONS OF THE FA. NOT CERTAIN THAT MUCH PRECIP WILL BE ABLE TO
DEVELOP THAT FAR N...BUT INSTABILITY...LOW CIN...AND UPSTREAM
SHORTWAVE WARRANTS CONTINUING MENTION OF TSRA. TEMPERATURES SHOULD
REMAIN UNSEASONABLY MILD...AND RANGE FROM THE UPPER 50S TO LOWER 60S.
TRUETT
&&
.LONG TERM...
ISSUED AT 259 PM CDT THU MAR 15 2012
(FRIDAY THROUGH NEXT THURSDAY)
NOT MUCH HAS CHANGED IN MDL SOLNS FROM YESTERDAY. MDLS STILL SUGGEST
REGION REMAINS IN A SIMILAR AIRMASS INTO THE WEEKEND. MDLS PROG H85
TEMPS TO REMAIN IN THE 12C TO 14C RANGE. SCT TSRA DURING THE
AFTERNOON INTO THE EVENING AND AGAIN JUST BEFORE AND AFTER SUNRISE.
HAVE THEREFORE KEPT PERSISTENCE FORECAST GOING INTO SUN WITH ONLY
MINOR TWEAKS FROM DAY TO DAY. SAT NIGHT DOES HAVE SOME UNCERTAINTY
REGARDING TEMPS/POPS. MDLS CONTINUE TO DEPICT MCS/MCV ON SAT INTO
SAT NIGHT MOVING NEWD INTO/NEAR THE CWA. MDLS AGREE ON THE
OCCURRENCE OF THIS FEATURE. HOWEVER...TIMING AND TRACK DIFFER. TEMPS
ON SAT AND POSSIBLY INTO SUN WILL GREATLY DEPEND ON WHICH SOLN
VERIFIES.
LIKEWISE...THE GOING MAX TEMPS ARE BASED ON EXPECTING ISOD TO SCT
TSRA...DEPENDING ON LOCATION IN THE CWA. BELIEVE BEST CHANCES FOR
MULTICELL CLUSTERS WILL BE OUTSIDE OF THE CWA. HOWEVER...IF THE
LOCATION CHANGES...TEMPS WILL HAVE TO BE ALTERED IN FUTURE UPDATES
TO ACCOUNT FOR THIS.
AS FOR SVR CHANCES...WITH SAME THINKING AS MENTIONED ABOVE...AN ISOD
SVR TSRA WILL BE POSSIBLE INTO THE WEEKEND. MDLS PROG MLCAPE AROUND
2000 J/KG WITH STEEP MID LVL LAPSE RATES. DEEP LAYER SHEER WILL BE
DIMINISHED...LIMITING ORGANIZED THREAT.
FOR THE EXTD...PERSISTENCE TRENDS CONTINUE EARLY INTO THE PERIOD.
MDLS CONTINUE TO DEPICT LEE CYCLOGENESIS ON DEEP TROF CROSSING THE
ROCKIES MON INTO TUES. THIS SYSTEM WILL BEGIN TO AFFECT THE CWA AS
EARLY AS MON AND A NUMBER OF S/WS EJECT INTO THE PLAINS INCREASING
THE CHANCE OF TSRA ACROSS THE AREA.
MDLS AGREE WITH A CUT OFF LOW DEVELOPING AND EVENTUALLY IMPACTING
THE CWA. HOWEVER...MDLS DISAGREE REGARDING TIMING. FOR NOW...HAVE
CONTINUED LOWER END CHANCE POPS AND WILL INCREASE AS CONFIDENCE
INCREASES.
HAVE CONTINUED WARM TREND THRU THE EXTD PERIOD...BUT TEMPS ARE
EXPECTED TO BE COOLER WED INTO THURS AS CUT OFF LOW APPROACHES AND
SPREADS PRECIP/CLOUDS INTO THE REGION.
TILLY
&&
.AVIATION...
ISSUED AT 1234 PM CDT THU MAR 15 2012
THIS MORNINGS CONVECTIVE CLUSTER PUSHING INTO S IL ATTM...SO
FORECAST TRENDS FOR THIS AFTERNOON DEAL WITH REDEVELOPMENT IN THE
WAKE OF THIS SYSTEM. AMS IS MODERATLY UNSTABLE WITH LITTLE
CIN...SO EXPECT HIT AND MISS CONVECTION DURING THE AFTERNOON. ATTM
NOT CERTAIN IF AND/OR WHERE THE MAIN COVERAGE OF THIS AFTERNOONS
CONVECTION WILL BE...ALTHOUGH HRRR DATA HAS BEEN HINTING THAT THE
SOMEWHAT BETTER FOCUS FOR STORMS WILL BE FROM THE EASTERN OZARKS
THROUGH THE STL AREA. FOR NOW HAVE HIGHLIGHTED TS THREAT WITH CB
CLOUD GROUP ALG AND S OF I-70 CORRIDOR. HAVE ALSO KEPT CB GROUP
GOING INTO THE EVENING...AS THERE SEEMS TO BE SOME MODEL CONSENSUS
THAT SHORTWAVE CURRENTLY OVER OK WILL KEEP SOME THREAT GOING PAST
MAX HEATING. FINALLY...GIVEN PERSISTENT S FLOW AND CONDITIONS OVER
THE PLAINS AROUND DAYBREAK THIS MORNING...HAVE INTRODUCED A BIT OF
FOG AND STRATUS FOR EARLY FRIDAY MORNING...PRIMARILY IN UIN AND
COU.
SPECIFICS FOR KSTL...TAF ATTEMPTS TO REFLECT AN AMS-TYPE TSRA
THREAT WITH A BKN CU FIELD...VCSH...AND CB CLOUD GROUP...AND WILL
REFINE THIS IF/WHEN CONVECTIVE TRENDS BECOME A BIT BETTER DEFINED.
AS MENTIONED ABOVE...HAVE ALSO HELD ONTO CB CLOUD GROUP PAST MAX
HEATING AND THROUGHOUT THE EVENING DUE TO UPSTREAM SHORTWAVE.
TRUETT
&&
.CLIMATE...
HERE ARE THE RECORD HIGH MAXIMUM AND HIGH MINIMUM TEMPERATURES
FOR KSTL AND KCOU FOR THURSDAY 03/15 AND FRIDAY 03/16.
KSTL
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 80F 1945 60F 1919
FRI 03/16 86F 1945 57F 1919
KCOU
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 79F 1914 62F 1919
FRI 03/16 87F 1945 55F 1945
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 85 65 85 / 40 30 20 40
QUINCY 60 83 59 83 / 30 20 20 40
COLUMBIA 61 82 60 82 / 30 20 20 50
JEFFERSON CITY 61 82 63 82 / 30 20 20 50
SALEM 61 80 62 80 / 50 40 30 40
FARMINGTON 61 81 62 81 / 60 40 30 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
301 PM CDT THU MAR 15 2012
.SHORT TERM...
ISSUED AT 345 AM CDT THU MAR 15 2012
(TODAY AND TONIGHT)
LITTLE CHANGE IN THINKING SINCE PREVIOUS FORECAST. TEMPERATURES
WARMED UP ABOVE GUIDANCE YET AGAIN ON WEDNESDAY...AND I SEE NO
REASON NOT TO GO ABOVE GUIDANCE AGAIN TODAY. AM LESS CONFIDENT IN
MID 80S TODAY THAN YESTERDAY THOUGH SINCE CONVECTION MAY BE MORE
WIDESPREAD ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE CWFA AS A
SHORTWAVE RIPPLES EAST OUT OF THE PLAINS INTO THE MID-MISSISSIPPI
VALLEY. WENT 2-3 DEGREES WARMER THAN WARMEST MAV GUIDANCE ACROSS
MOST OF THE AREA. HAVE INCREASED POPS ACROSS SOUTHERN SECTIONS TO
LIKELY AS WELL TO BETTER REPRESENT THE PROPOSED TRACK OF THE
SHORTWAVE. SHOULD SEE CONVECTION DIMINISH DURING THE EVENING SINCE
THE WAVE MOVES EAST AND THERE DOESN`T APPEAR TO BE MUCH FORCING TO
MAINTAIN STORMS ESPECIALLY AFTER MIDNIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 259 PM CDT THU MAR 15 2012
(FRIDAY THROUGH NEXT THURSDAY)
NOT MUCH HAS CHANGED IN MDL SOLNS FROM YESTERDAY. MDLS STILL SUGGEST
REGION REMAINS IN A SIMILAR AIRMASS INTO THE WEEKEND. MDLS PROG H85
TEMPS TO REMAIN IN THE 12C TO 14C RANGE. SCT TSRA DURING THE
AFTERNOON INTO THE EVENING AND AGAIN JUST BEFORE AND AFTER SUNRISE.
HAVE THEREFORE KEPT PERSISTENCE FORECAST GOING INTO SUN WITH ONLY
MINOR TWEAKS FROM DAY TO DAY. SAT NIGHT DOES HAVE SOME UNCERTAINTY
REGARDING TEMPS/POPS. MDLS CONTINUE TO DEPICT MCS/MCV ON SAT INTO
SAT NIGHT MOVING NEWD INTO/NEAR THE CWA. MDLS AGREE ON THE
OCCURRENCE OF THIS FEATURE. HOWEVER...TIMING AND TRACK DIFFER. TEMPS
ON SAT AND POSSIBLY INTO SUN WILL GREATLY DEPEND ON WHICH SOLN
VERIFIES.
LIKEWISE...THE GOING MAX TEMPS ARE BASED ON EXPECTING ISOD TO SCT
TSRA...DEPENDING ON LOCATION IN THE CWA. BELIEVE BEST CHANCES FOR
MULTICELL CLUSTERS WILL BE OUTSIDE OF THE CWA. HOWEVER...IF THE
LOCATION CHANGES...TEMPS WILL HAVE TO BE ALTERED IN FUTURE UPDATES
TO ACCOUNT FOR THIS.
AS FOR SVR CHANCES...WITH SAME THINKING AS MENTIONED ABOVE...AN ISOD
SVR TSRA WILL BE POSSIBLE INTO THE WEEKEND. MDLS PROG MLCAPE AROUND
2000 J/KG WITH STEEP MID LVL LAPSE RATES. DEEP LAYER SHEER WILL BE
DIMINISHED...LIMITING ORGANIZED THREAT.
FOR THE EXTD...PERSISTENCE TRENDS CONTINUE EARLY INTO THE PERIOD.
MDLS CONTINUE TO DEPICT LEE CYCLOGENESIS ON DEEP TROF CROSSING THE
ROCKIES MON INTO TUES. THIS SYSTEM WILL BEGIN TO AFFECT THE CWA AS
EARLY AS MON AND A NUMBER OF S/WS EJECT INTO THE PLAINS INCREASING
THE CHANCE OF TSRA ACROSS THE AREA.
MDLS AGREE WITH A CUT OFF LOW DEVELOPING AND EVENTUALLY IMPACTING
THE CWA. HOWEVER...MDLS DISAGREE REGARDING TIMING. FOR NOW...HAVE
CONTINUED LOWER END CHANCE POPS AND WILL INCREASE AS CONFIDENCE
INCREASES.
HAVE CONTINUED WARM TREND THRU THE EXTD PERIOD...BUT TEMPS ARE
EXPECTED TO BE COOLER WED INTO THURS AS CUT OFF LOW APPROACHES AND
SPREADS PRECIP/CLOUDS INTO THE REGION.
TILLY
&&
.AVIATION...
ISSUED AT 1234 PM CDT THU MAR 15 2012
THIS MORNINGS CONVECTIVE CLUSTER PUSHING INTO S IL ATTM...SO
FORECAST TRENDS FOR THIS AFTERNOON DEAL WITH REDEVELOPMENT IN THE
WAKE OF THIS SYSTEM. AMS IS MODERATLY UNSTABLE WITH LITTLE
CIN...SO EXPECT HIT AND MISS CONVECTION DURING THE AFTERNOON. ATTM
NOT CERTAIN IF AND/OR WHERE THE MAIN COVERAGE OF THIS AFTERNOONS
CONVECTION WILL BE...ALTHOUGH HRRR DATA HAS BEEN HINTING THAT THE
SOMEWHAT BETTER FOCUS FOR STORMS WILL BE FROM THE EASTERN OZARKS
THROUGH THE STL AREA. FOR NOW HAVE HIGHLIGHTED TS THREAT WITH CB
CLOUD GROUP ALG AND S OF I-70 CORRIDOR. HAVE ALSO KEPT CB GROUP
GOING INTO THE EVENING...AS THERE SEEMS TO BE SOME MODEL CONSENSUS
THAT SHORTWAVE CURRENTLY OVER OK WILL KEEP SOME THREAT GOING PAST
MAX HEATING. FINALLY...GIVEN PERSISTENT S FLOW AND CONDITIONS OVER
THE PLAINS AROUND DAYBREAK THIS MORNING...HAVE INTRODUCED A BIT OF
FOG AND STRATUS FOR EARLY FRIDAY MORNING...PRIMARILY IN UIN AND
COU.
SPECIFICS FOR KSTL...TAF ATTEMPTS TO REFLECT AN AMS-TYPE TSRA
THREAT WITH A BKN CU FIELD...VCSH...AND CB CLOUD GROUP...AND WILL
REFINE THIS IF/WHEN CONVECTIVE TRENDS BECOME A BIT BETTER DEFINED.
AS MENTIONED ABOVE...HAVE ALSO HELD ONTO CB CLOUD GROUP PAST MAX
HEATING AND THROUGHOUT THE EVENING DUE TO UPSTREAM SHORTWAVE.
TRUETT
&&
.CLIMATE...
HERE ARE THE RECORD HIGH MAXIMUM AND HIGH MINIMUM TEMPERATURES
FOR KSTL AND KCOU FOR THURSDAY 03/15 AND FRIDAY 03/16.
KSTL
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 80F 1945 60F 1919
FRI 03/16 86F 1945 57F 1919
KCOU
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 79F 1914 62F 1919
FRI 03/16 87F 1945 55F 1945
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 63 85 65 85 / 40 30 20 40
QUINCY 60 83 59 83 / 30 20 20 40
COLUMBIA 61 82 60 82 / 40 20 20 50
JEFFERSON CITY 61 82 63 82 / 40 20 20 50
SALEM 61 80 62 80 / 40 40 30 40
FARMINGTON 61 81 62 81 / 40 40 30 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
140 PM CDT THU MAR 15 2012
.UPDATE...
ISSUED AT 135 PM CDT THU MAR 15 2012
AFTERNOON CONVECTION IS NOW SHOWING ITS HAND. BASED ON TRENDS THE
LAST 45 MINUTES IT WOULD APPEAR THAT BEST COVERAGE OF STORMS WILL
BE ALONG AND SOUTH OF A KIH...CPS...1H2 LINE...ALTHOUGH AM
CERTAINLY NOT DISCOUNTING DEVELOMENT FURTHER N WITH MUCAPES
2000-2500 AND LITTLE IF ANY CIN. ALSO TWEEKED TEMPS DOWN A BIT IN
THE FAR S...WHERE TEMPS ARE STRUGGLING TO RECOVER FROM THE MORNING
CONVECTION.
TRUETT
&&
.SHORT TERM...
ISSUED AT 345 AM CDT THU MAR 15 2012
(TODAY AND TONIGHT)
LITTLE CHANGE IN THINKING SINCE PREVIOUS FORECAST. TEMPERATURES
WARMED UP ABOVE GUIDANCE YET AGAIN ON WEDNESDAY...AND I SEE NO
REASON NOT TO GO ABOVE GUIDANCE AGAIN TODAY. AM LESS CONFIDENT IN
MID 80S TODAY THAN YESTERDAY THOUGH SINCE CONVECTION MAY BE MORE
WIDESPREAD ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE CWFA AS A
SHORTWAVE RIPPLES EAST OUT OF THE PLAINS INTO THE MID-MISSISSIPPI
VALLEY. WENT 2-3 DEGREES WARMER THAN WARMEST MAV GUIDANCE ACROSS
MOST OF THE AREA. HAVE INCREASED POPS ACROSS SOUTHERN SECTIONS TO
LIKELY AS WELL TO BETTER REPRESENT THE PROPOSED TRACK OF THE
SHORTWAVE. SHOULD SEE CONVECTION DIMINISH DURING THE EVENING SINCE
THE WAVE MOVES EAST AND THERE DOESN`T APPEAR TO BE MUCH FORCING TO
MAINTAIN STORMS ESPECIALLY AFTER MIDNIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 345 AM CDT THU MAR 15 2012
(FRIDAY THROUGH WEDNESDAY)
LITTLE CHANGE IN THINKING SINCE PREVIOUS FORECAST. TEMPERATURES
WARMED UP ABOVE GUIDANCE YET AGAIN ON WEDNESDAY...AND I SEE NO
REASON NOT TO GO ABOVE GUIDANCE AGAIN TODAY. AM LESS CONFIDENT IN
MID 80S TODAY THAN YESTERDAY THOUGH SINCE CONVECTION MAY BE MORE
WIDESPREAD ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE CWFA AS A
SHORTWAVE RIPPLES EAST OUT OF THE PLAINS INTO THE MID-MISSISSIPPI
VALLEY. WENT 2-3 DEGREES WARMER THAN WARMEST MAV GUIDANCE ACROSS
MOST OF THE AREA. HAVE INCREASED POPS ACROSS SOUTHERN SECTIONS TO
LIKELY AS WELL TO BETTER REPRESENT THE PROPOSED TRACK OF THE
SHORTWAVE. SHOULD SEE CONVECTION DIMINISH DURING THE EVENING SINCE
THE WAVE MOVES EAST AND THERE DOESN`T APPEAR TO BE MUCH FORCING TO
MAINTAIN STORMS ESPECIALLY AFTER MIDNIGHT.
CONTINUING THE IDEA OF ISOLATED TO WIDELY SCATTERED CONVECTION EACH
DAY THROUGH THE WEEKEND AS SOUTHWEST FLOW CONTINUES OVER THE AREA.
THE BEST CHANCE LOOKS LIKE SATURDAY WHEN ANOTHER WELL DEFINED
SHORTWAVE RIPPLES OUT OF THE SOUTHERN PLAINS ACROSS MISSOURI. NOT
QUITE READY TO INCREASE POPS ABOVE CHANCE SINCE THE STRENGTH OF THE
WAVE MAY BE DUE TO CONVECTIVE FEEDBACK...BUT LIKELY POPS WOULD BE
VERY APPROPRIATE IF SUBSEQUENT MODEL RUNS CONTINUE TO SHOW THIS
WAVE. MEDIUM RANGE MODELS STILL SHOW THE FLOW UNDERGOING
EYE-POPPING AMPLIFICATION SUNDAY INTO MONDAY AS A DEEP LONGWAVE TROF
DEVELOPS OVER THE WESTERN U.S. AND A RIDGE AMPLIFIES OVER THE
APPALACHIANS. SHOULD SEE RAIN CHANCES FALL OFF AS THIS OCCURS SINCE
WE`LL BE CLOSER TO THE RIDGE AXIS THAN THE TROF. HOWEVER...BOTH THE
ECMWF AND GFS SHOW A TREMENDOUS AMOUNT OF LOW LEVEL MOISTURE
CONVERGENCE SPREADING ACROSS WESTERN MISSOURI BY 00Z TUESDAY...WITH
AN IMPRESSIVE AMOUNT OF QPF ASSOCIATED WITH IT. IT DOESN`T QUITE
GET INTO OUR CENTRAL MISSOURI COUNTIES...BUT I THINK IT`S TOO CLOSE
TO PULL OUT CHANCES IN CENTRAL MO AT THIS TIME. SHOULD SEE THOSE
CHANCE POPS OVERSPREAD THE REST OF THE AREA AS THE TROF STARTS TO
SLOWLY MOVE EAST...THOUGH AM NOT SURE ON TIMING AT THIS JUNCTURE.
THIS IS CERTAINLY AN UNSEASONABLE PATTERN...SO CONFIDENCE IN THE
FORECAST FOR NEXT WEEK IS PRETTY LOW.
CARNEY
&&
.AVIATION...
ISSUED AT 1234 PM CDT THU MAR 15 2012
THIS MORNINGS CONVECTIVE CLUSTER PUSHING INTO S IL ATTM...SO
FORECAST TRENDS FOR THIS AFTERNOON DEAL WITH REDEVELOPMENT IN THE
WAKE OF THIS SYSTEM. AMS IS MODERATLY UNSTABLE WITH LITTLE
CIN...SO EXPECT HIT AND MISS CONVECTION DURING THE AFTERNOON. ATTM
NOT CERTAIN IF AND/OR WHERE THE MAIN COVERAGE OF THIS AFTERNOONS
CONVECTION WILL BE...ALTHOUGH HRRR DATA HAS BEEN HINTING THAT THE
SOMEWHAT BETTER FOCUS FOR STORMS WILL BE FROM THE EASTERN OZARKS
THROUGH THE STL AREA. FOR NOW HAVE HIGHLIGHTED TS THREAT WITH CB
CLOUD GROUP ALG AND S OF I-70 CORRIDOR. HAVE ALSO KEPT CB GROUP
GOING INTO THE EVENING...AS THERE SEEMS TO BE SOME MODEL CONSENSUS
THAT SHORTWAVE CURRENTLY OVER OK WILL KEEP SOME THREAT GOING PAST
MAX HEATING. FINALLY...GIVEN PERSISTENT S FLOW AND CONDITIONS OVER
THE PLAINS AROUND DAYBREAK THIS MORNING...HAVE INTRODUCED A BIT OF
FOG AND STRATUS FOR EARLY FRIDAY MORNING...PRIMARILY IN UIN AND
COU.
SPECIFICS FOR KSTL...TAF ATTEMPTS TO REFLECT AN AMS-TYPE TSRA
THREAT WITH A BKN CU FIELD...VCSH...AND CB CLOUD GROUP...AND WILL
REFINE THIS IF/WHEN CONVECTIVE TRENDS BECOME A BIT BETTER DEFINED.
AS MENTIONED ABOVE...HAVE ALSO HELD ONTO CB CLOUD GROUP PAST MAX
HEATING AND THROUGHOUT THE EVENING DUE TO UPSTREAM SHORTWAVE.
TRUETT
&&
.CLIMATE...
HERE ARE THE RECORD HIGH MAXIMUM AND HIGH MINIMUM TEMPERATURES
FOR KSTL AND KCOU FOR THURSDAY 03/15 AND FRIDAY 03/16.
KSTL
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 80F 1945 60F 1919
FRI 03/16 86F 1945 57F 1919
KCOU
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 79F 1914 62F 1919
FRI 03/16 87F 1945 55F 1945
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 85 61 85 65 / 40 40 30 20
QUINCY 82 60 83 59 / 30 30 20 20
COLUMBIA 82 60 82 60 / 40 40 20 20
JEFFERSON CITY 82 58 82 63 / 40 40 20 20
SALEM 75 59 80 62 / 50 40 40 30
FARMINGTON 73 59 81 62 / 60 40 40 30
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1246 PM CDT THU MAR 15 2012
.SHORT TERM...
ISSUED AT 345 AM CDT THU MAR 15 2012
(TODAY AND TONIGHT)
LITTLE CHANGE IN THINKING SINCE PREVIOUS FORECAST. TEMPERATURES
WARMED UP ABOVE GUIDANCE YET AGAIN ON WEDNESDAY...AND I SEE NO
REASON NOT TO GO ABOVE GUIDANCE AGAIN TODAY. AM LESS CONFIDENT IN
MID 80S TODAY THAN YESTERDAY THOUGH SINCE CONVECTION MAY BE MORE
WIDESPREAD ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE CWFA AS A
SHORTWAVE RIPPLES EAST OUT OF THE PLAINS INTO THE MID-MISSISSIPPI
VALLEY. WENT 2-3 DEGREES WARMER THAN WARMEST MAV GUIDANCE ACROSS
MOST OF THE AREA. HAVE INCREASED POPS ACROSS SOUTHERN SECTIONS TO
LIKELY AS WELL TO BETTER REPRESENT THE PROPOSED TRACK OF THE
SHORTWAVE. SHOULD SEE CONVECTION DIMINISH DURING THE EVENING SINCE
THE WAVE MOVES EAST AND THERE DOESN`T APPEAR TO BE MUCH FORCING TO
MAINTAIN STORMS ESPECIALLY AFTER MIDNIGHT.
CARNEY
&&
.LONG TERM...
ISSUED AT 345 AM CDT THU MAR 15 2012
(FRIDAY THROUGH WEDNESDAY)
LITTLE CHANGE IN THINKING SINCE PREVIOUS FORECAST. TEMPERATURES
WARMED UP ABOVE GUIDANCE YET AGAIN ON WEDNESDAY...AND I SEE NO
REASON NOT TO GO ABOVE GUIDANCE AGAIN TODAY. AM LESS CONFIDENT IN
MID 80S TODAY THAN YESTERDAY THOUGH SINCE CONVECTION MAY BE MORE
WIDESPREAD ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE CWFA AS A
SHORTWAVE RIPPLES EAST OUT OF THE PLAINS INTO THE MID-MISSISSIPPI
VALLEY. WENT 2-3 DEGREES WARMER THAN WARMEST MAV GUIDANCE ACROSS
MOST OF THE AREA. HAVE INCREASED POPS ACROSS SOUTHERN SECTIONS TO
LIKELY AS WELL TO BETTER REPRESENT THE PROPOSED TRACK OF THE
SHORTWAVE. SHOULD SEE CONVECTION DIMINISH DURING THE EVENING SINCE
THE WAVE MOVES EAST AND THERE DOESN`T APPEAR TO BE MUCH FORCING TO
MAINTAIN STORMS ESPECIALLY AFTER MIDNIGHT.
CONTINUING THE IDEA OF ISOLATED TO WIDELY SCATTERED CONVECTION EACH
DAY THROUGH THE WEEKEND AS SOUTHWEST FLOW CONTINUES OVER THE AREA.
THE BEST CHANCE LOOKS LIKE SATURDAY WHEN ANOTHER WELL DEFINED
SHORTWAVE RIPPLES OUT OF THE SOUTHERN PLAINS ACROSS MISSOURI. NOT
QUITE READY TO INCREASE POPS ABOVE CHANCE SINCE THE STRENGTH OF THE
WAVE MAY BE DUE TO CONVECTIVE FEEDBACK...BUT LIKELY POPS WOULD BE
VERY APPROPRIATE IF SUBSEQUENT MODEL RUNS CONTINUE TO SHOW THIS
WAVE. MEDIUM RANGE MODELS STILL SHOW THE FLOW UNDERGOING
EYE-POPPING AMPLIFICATION SUNDAY INTO MONDAY AS A DEEP LONGWAVE TROF
DEVELOPS OVER THE WESTERN U.S. AND A RIDGE AMPLIFIES OVER THE
APPALACHIANS. SHOULD SEE RAIN CHANCES FALL OFF AS THIS OCCURS SINCE
WE`LL BE CLOSER TO THE RIDGE AXIS THAN THE TROF. HOWEVER...BOTH THE
ECMWF AND GFS SHOW A TREMENDOUS AMOUNT OF LOW LEVEL MOISTURE
CONVERGENCE SPREADING ACROSS WESTERN MISSOURI BY 00Z TUESDAY...WITH
AN IMPRESSIVE AMOUNT OF QPF ASSOCIATED WITH IT. IT DOESN`T QUITE
GET INTO OUR CENTRAL MISSOURI COUNTIES...BUT I THINK IT`S TOO CLOSE
TO PULL OUT CHANCES IN CENTRAL MO AT THIS TIME. SHOULD SEE THOSE
CHANCE POPS OVERSPREAD THE REST OF THE AREA AS THE TROF STARTS TO
SLOWLY MOVE EAST...THOUGH AM NOT SURE ON TIMING AT THIS JUNCTURE.
THIS IS CERTAINLY AN UNSEASONABLE PATTERN...SO CONFIDENCE IN THE
FORECAST FOR NEXT WEEK IS PRETTY LOW.
CARNEY
&&
.AVIATION...
ISSUED AT 1234 PM CDT THU MAR 15 2012
THIS MORNINGS CONVECTIVE CLUSTER PUSHING INTO S IL ATTM...SO
FORECAST TRENDS FOR THIS AFTERNOON DEAL WITH REDEVELOPMENT IN THE
WAKE OF THIS SYSTEM. AMS IS MODERATLY UNSTABLE WITH LITTLE
CIN...SO EXPECT HIT AND MISS CONVECTION DURING THE AFTERNOON. ATTM
NOT CERTAIN IF AND/OR WHERE THE MAIN COVERAGE OF THIS AFTERNOONS
CONVECTION WILL BE...ALTHOUGH HRRR DATA HAS BEEN HINTING THAT THE
SOMEWHAT BETTER FOCUS FOR STORMS WILL BE FROM THE EASTERN OZARKS
THROUGH THE STL AREA. FOR NOW HAVE HIGHLIGHTED TS THREAT WITH CB
CLOUD GROUP ALG AND S OF I-70 CORRIDOR. HAVE ALSO KEPT CB GROUP
GOING INTO THE EVENING...AS THERE SEEMS TO BE SOME MODEL CONSENSUS
THAT SHORTWAVE CURRENTLY OVER OK WILL KEEP SOME THREAT GOING PAST
MAX HEATING. FINALLY...GIVEN PERSISTENT S FLOW AND CONDITIONS OVER
THE PLAINS AROUND DAYBREAK THIS MORNING...HAVE INTRODUCED A BIT OF
FOG AND STRATUS FOR EARLY FRIDAY MORNING...PRIMARILY IN UIN AND
COU.
SPECIFICS FOR KSTL...TAF ATTEMPTS TO REFLECT AN AMS-TYPE TSRA
THREAT WITH A BKN CU FIELD...VCSH...AND CB CLOUD GROUP...AND WILL
REFINE THIS IF/WHEN CONVECTIVE TRENDS BECOME A BIT BETTER DEFINED.
AS MENTIONED ABOVE...HAVE ALSO HELD ONTO CB CLOUD GROUP PAST MAX
HEATING AND THROUGHOUT THE EVENING DUE TO UPSTREAM SHORTWAVE.
TRUETT
&&
.CLIMATE...
HERE ARE THE RECORD HIGH MAXIMUM AND HIGH MINIMUM TEMPERATURES
FOR KSTL AND KCOU FOR THURSDAY 03/15 AND FRIDAY 03/16.
KSTL
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 80F 1945 60F 1919
FRI 03/16 86F 1945 57F 1919
KCOU
DAY DATE HI MAX YEAR HI MIN YEAR
THU 03/15 79F 1914 62F 1919
FRI 03/16 87F 1945 55F 1945
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 85 61 85 65 / 40 40 30 20
QUINCY 83 60 83 59 / 30 30 20 20
COLUMBIA 82 60 82 60 / 40 40 20 20
JEFFERSON CITY 82 58 82 63 / 40 40 20 20
SALEM 80 59 80 62 / 50 40 40 30
FARMINGTON 81 59 81 62 / 60 40 40 30
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1021 AM MDT THU MAR 15 2012
.SHORT TERM...VALID FOR TDY AND FRI...
LOW- AND MID-LEVEL WARM AIR ADVECTION WILL OCCUR TODAY WHILE THERE
ARE SOME HEIGHT RISES ALOFT. ONLY MINOR CHANGES APPEAR IN ORDER TO
THE CURRENT FORECAST...WHICH ADVERTISES RECORD OR NEAR RECORD HIGH
TEMPERATURES IN MANY AREAS...AND A RED FLAG WARNING ACROSS MOST OF
SOUTH CENTRAL MT BELOW 5000 FT BEGINNING AT 18 UTC. THERE IS A BIT
OF UNCERTAINTY AS TO HOW DEEPLY WE WILL MIX THIS AFTERNOON...WHICH
WILL HAVE AN IMPACT ON WINDS AND TEMPERATURES. THE 12 UTC NAM ONLY
MIXES SOUTH CENTRAL MT OUT TO AROUND 700 HPA BECAUSE THE ADVECTION
OF WARM AIR INTO THE MID LEVELS CAPS THE BOUNDARY LAYER A BIT. THE
RECENT RUC RUNS...ON THE OTHER HAND...SIMULATE MIXING TO ABOUT 600
HPA AT BILLINGS. THE LATTER SOLUTION IS NOT UNREASONABLE GIVEN THE
TRENDS OVER THE PAST FEW DAYS...SO WE WILL NEED TO BE AWARE OF THE
POTENTIAL FOR TEMPERATURES TO BE A BIT WARMER THAN FORECAST. WINDS
IN THE MIXED LAYER PEAK AT 30 TO 35 KT...SO WE SHOULD HAVE SOME 30
MPH OR BETTER GUSTS THIS AFTERNOON IN SOUTH CENTRAL MT. SCHULTZ
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
THE EXTENDED PERIOD BEGINS SATURDAY WITH SHORTWAVE ENERGY MOVING
INTO THE REGION FROM THE SOUTHWEST. AS IT DOES...IT INTERACTS
WITH A SURFACE WARM FRONT LIFTING NORTHWARD TO BRING A CHANCE OF
PRECIP TO NORTHERN AND WESTERN PORTIONS OF THE CWA. ALTHOUGH
THERE IS NOT A LOT OF LOW LEVEL MOISTURE TO WORK WITH...DAYTIME
TEMPERATURES WILL BE UNSEASONABLY WARM WITH FAIRLY STEEP LAPSE
RATES...THUS CAPE VALUES OF A FEW HUNDRED J/KG WILL BE SUPPORTIVE
OF SOME WEAK CONVECTION DURING THE AFTERNOON/EVENING
HOURS...ESPECIALLY ACROSS THE WEST.
STRONGER SHORTWAVE ENERGY SUPPORTING A SURFACE COLD FRONT MOVES
INTO THE REGION DURING THE DAY SUNDAY. THE MAIN SURGE OF COLD AIR
ADVECTION DOES NOT LOOK LIKE IT WILL OCCUR UNTIL LATE IN THE DAY
ACROSS THE WEST...AND OVERNIGHT ACROSS THE EAST...BUT
AGAIN...UNSEASONABLY WARM DAYTIME TEMPERATURES IN AN INCREASINGLY
UNSTABLE ATMOSPHERE SHOULD GENERATE A COUPLE HUNDRED J/KG OF CAPE
ACROSS CENTRAL PORTIONS. THIS WILL SET THE STAGE FOR AT LEAST
SOME WEAK CONVECTION AHEAD OF THE FRONT...ESPECIALLY WHEN COUPLED
WITH JET ENERGY THAT IS EXPECTED TO BE CROSSING THE REGION.
BY LATE SUNDAY NIGHT INTO MONDAY...THE REGION WILL BE ON
THE COLD SIDE OF THE FRONT WITH HIGH TEMPERATURES MONDAY NOW EXPECTED
TO BE IN THE 40S AND 50S...SO FRONTOGENESIS INTERACTING WITH
SHORTWAVE ENERGY IN BROAD CYCLONIC FLOW ACROSS THE REGION SHOULD
BE ENOUGH TO PRODUCE WIDELY SCATTERED RAIN AND SNOW
SHOWERS...ESPECIALLY OVER THE HIGHER TERRAIN. THIS PATTERN IS
EXPECTED TO CONTINUE THROUGH TUESDAY...WITH THE COLD AIR ALOFT
INCREASING INSTABILITY. AS SUCH...KEPT BROADBRUSHED LOW POPS
ACROSS THE AREA.
MODELS SOLUTIONS DIVERGE FAIRLY SUBSTANTIALLY WEDNESDAY INTO
THURSDAY. THE GFS BRINGS ANOTHER COLD FRONT INTO THE REGION
WEDNESDAY INTO THURSDAY WITH PRECIP ACROSS THE CENTRAL AND
WEST...WHILE THE ECMWF BUILDS A RIDGE WEDNESDAY...AND DOES NOT
BRING THE FRONT INTO THE REGION UNTIL LATE THURSDAY. DUE TO THE
BIG DIFFERENCES...OPTED NOT TO MAKE ANY MAJOR CHANGES TO THE
WEDNESDAY/THURSDAY FORECAST. STC
&&
.AVIATION...
MAINLY VFR CONDITIONS WILL PREVAIL ACROSS THE AREA TODAY.
SOUTHWEST WINDS GUSTING TO MORE THAN 35 KTS ARE EXPECTED FROM
LATE THIS MORNING THROUGH THIS EVENING FROM KLVM TO BIG TIMBER
NORTH TO HARLOWTON...WITH SOUTHWEST WINDS GUSTING TO NEAR 30 KTS
AS FAR EAST AS ROUNDUP AND KBIL DURING THE AFTERNOON. WIDELY
SCATTERED MOUNTAIN RAIN AND SNOW SHOWERS WILL PRODUCE SOME
MOUNTAIN TOP OBSCURATIONS THROUGH THE DAY. BT
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 069 044/069 037/066 042/062 039/052 034/055 035/059
0/N 01/N 22/W 34/W 43/W 22/W 22/W
LVM 065 043/065 032/060 039/054 036/047 031/050 032/052
1/N 12/W 25/W 55/W 54/W 22/W 22/W
HDN 072 040/073 037/070 039/070 034/056 029/057 031/061
0/N 01/N 12/W 12/W 33/W 22/W 22/W
MLS 073 043/076 040/071 041/070 040/055 031/055 032/058
0/B 00/N 12/W 11/B 22/W 22/W 22/W
4BQ 072 041/075 039/072 042/071 037/055 032/056 032/058
0/B 00/N 11/B 11/N 22/W 22/W 22/W
BHK 071 040/074 039/068 041/071 036/055 031/052 031/056
0/B 00/N 12/W 11/B 22/W 22/W 22/W
SHR 068 041/070 036/068 038/064 035/049 028/052 029/055
0/B 01/N 11/B 12/W 33/W 33/W 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...FIRE WEATHER WATCH IN EFFECT FROM FRIDAY MORNING THROUGH
FRIDAY EVENING FOR ZONES 117-123-130>133.
RED FLAG WARNING IN EFFECT UNTIL 6 AM MDT FRIDAY BELOW 5000
FEET FOR ZONE 123.
RED FLAG WARNING IN EFFECT UNTIL 9 PM MDT FRIDAY BELOW 5000
FEET FOR ZONES 124>129.
WY...FIRE WEATHER WATCH IN EFFECT FROM FRIDAY MORNING THROUGH
FRIDAY EVENING FOR ZONE 274.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
345 PM CDT THU MAR 15 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY. MAIN FOCUS IS ON POTENTIAL
FOR FOG/STRATUS TONIGHT AND FRIDAY MORNING. A FAIRLY LARGE AREA OF
STRATUS ENCOMPASSED THE SOUTHEAST THIRD OF OUR CWA THIS MORNING AND
THE LOW CLOUDS HAVE BEEN SLOW TO ERODE EARLY THIS AFTERNOON. YORK
VSBY DROPPED TO A QUARTER MILE OR LESS FOR THE SECOND DAY IN A ROW
AND THE LOW VSBY LINGERED TO AROUND 15Z. MOISTURE AXIS AROUND
MIDDAY WAS LOCATED FROM KOLU TO KHSI TO KHLC WITH DPS ALONG AND
SOUTH OF THIS LINE IN THE 50S. MODELS INDICATE MOISTURE AXIS WILL
EXPAND FARTHER NORTH AND WEST TONIGHT AS WINDS TRANSITION SOUTHERLY
AND REMAIN LIGHT. EXPECT STRATUS TO REDEVELOP ACROSS A LARGER
AREA...AND ENCOMPASS A GOOD PORTION OF OUR CWA. FOG/REDUCED VSBYS
HAVE BEEN A FAIRLY COMMON THEME IN THIS REGIME AND PLAN TO GO WITH
PERSISTENCE IN THIS PATTERN. POTENTIAL EXISTS FOR MORE WIDESPREAD
VSBY RESTRICTIONS FRIDAY MORNING BASED ON RUC13 VSBYS PROGS AND
MODEL NUMERICAL GUIDANCE. MODELS DO INDICATE A LITTLE MORE IN THE
WAY OF MIXING OVER THE STRATUS...AND CONTEMPLATED ADDING IN SOME
DRIZZLE MENTION...HOWEVER CONFIDENCE IN DRIZZLE IS NOT HIGH ENOUGH
ATTM. IN HIGHER MOISTURE TONIGHT...GENERALLY LOOKING AT MILDER LOWS
RANGING FM NEAR 40 ON THE WESTERN EDGE OF STRATUS...TO LOW/MID 50S
IN THE SOUTHEAST CWA WHERE DPS ARE HIGHER.
LOW CLOUDS ARE EXPECTED TO ERODE AROUND MID DAY ON FRIDAY AND
SOUTHERLY WINDS WILL BE ON THE INCREASE DURING THE AFTERNOON. IN
BETTER MIXING CONDITIONS...TEMPS SHOULD REACH THE UPPER 70S TO THE
LOWER 80S FOR HIGHS.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY.
BEGINNING THE LONG TERM...MUCH OF THE CONUS REMAINS UNDER THE
INFLUENCE OF AN UPPER LEVEL RIDGE...WHILE AN UPPER LEVEL TROUGH
BEGINS TO PUSH EAST JUST OFF THE WEST COAST. THE UPPER LEVEL TROUGH
CONTINUES TO DEEPEN THROUGH THE WEEKEND...PUSHING THE TROUGH AXIS
ACROSS SOUTHERN CALIFORNIA BY SUNDAY. A SURFACE LOW PRESSURE SYSTEM
WILL BEGIN TO DEVELOP ACROSS THE NORTHERN ROCKIES AND MONTANA BY
SUNDAY. THIS SYSTEM WILL HELP INCREASE A PRESSURE GRADIENT ACROSS
THE CENTRAL PLAINS...AND THUS INCREASING SOUTH WINDS ACROSS THE
FORECAST AREA TO NEAR WIND ADVISORY CRITERIA.
AHEAD OF THE TROUGH...MOISTURE IS EXPECTED TO SURGE NORTHWARD FROM
THE GULF OF MEXICO. WHILE THE EC KEEPS MOISTURE WELL TO THE SOUTH
ON SUNDAY...THE GFS BRINGS THE MOISTURE MUCH FARTHER NORTH MAINLY
ACROSS FAR EASTERN NEBRASKA AND IOWA. BOTH THE GFS AND THE EC
CONTINUE TO SURGE MOISTURE NORTHWARD ON MONDAY...INCLUDING ACROSS
PORTIONS OF CENTRAL AND EASTERN NEBRASKA AND KANSAS. BOTH MODELS
ALSO HINT AT THE POSSIBILITY FOR THUNDERSTORMS AND POTENTIALLY
SEVERE THUNDERSTORMS...AS MU CAPES APPROACH 500 TO 1500 J/KG.
THE UPPER LEVEL SYSTEM PUSHES A COLD FRONT THROUGH THE REGION
TUESDAY AFTERNOON DECREASING HIGH TEMPERATURES BY ABOUT 10 DEGREES
THROUGH THE REMAINDER OF THE PERIOD. HOWEVER...BOTH MODELS CONTINUE
TO PUSH ANY MOISTURE FARTHER EAST ACROSS IOWA THROUGH WEDNESDAY.
BY WEDNESDAY MORNING...THE TROUGH AXIS CONTINUES TO DEEPEN FINALLY
CLOSING OFF THE UPPER LEVEL LOW ACROSS TEXAS. AT THE SURFACE...THE
EC IS BEGINNING TO LOOK MORE LIKE THE GFS WITH A SURFACE LOW
PRESSURE SYSTEM SURGING NORTH FROM THE GULF OF MEXICO ACROSS EASTERN
TEXAS. THIS LOW LOOKS TO SPIN NORTH ACROSS THE OKLAHOMA TEXAS
PANHANDLE WRAPPING AROUND YET ANOTHER ROUND OF PRECIPITATION ACROSS
KANSAS AND SOUTHERN NEBRASKA BY WEDNESDAY NIGHT INTO THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 1209 PM CDT THU MAR 15 2012/
AVIATION...18Z TAF. LOW CLOUDS THIS AFTN SOUTH OF THE TERMINAL
ARE EXPECTED TO REMAIN TO THE SOUTH...ALTHOUGH KGRI MAY SEE SOME
SCATTERED VFR CLOUDS. TONIGHT HOWEVER...LOW CLOUDS LOOK TO ADVECT
TO KGRI OR KGRI MAY BE ON PERIPHERY OF THE LOW CLOUDS. IN
INCREASING MOISTURE/LIGHT WINDS FOG DEVELOPMENT IS LOOKING
PROBABLE AND INTRODUCED FOG AND IFR CIGS. CANNOT COMPLETELY RULE
OUT A FEW HOURS OF LIFR CONDITIONS. CLOUDS SHLD SCATTER FRIDAY MID
MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...CMF
LONG TERM...SALTZMAN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1209 PM CDT THU MAR 15 2012
.AVIATION...18Z TAF. LOW CLOUDS THIS AFTN SOUTH OF THE TERMINAL
ARE EXPECTED TO REMAIN TO THE SOUTH...ALTHOUGH KGRI MAY SEE SOME
SCATTERED VFR CLOUDS. TONIGHT HOWEVER...LOW CLOUDS LOOK TO ADVECT
TO KGRI OR KGRI MAY BE ON PERIPHERY OF THE LOW CLOUDS. IN
INCREASING MOISTURE/LIGHT WINDS FOG DEVELOPMENT IS LOOKING
PROBABLE AND INTRODUCED FOG AND IFR CIGS. CANNOT COMPLETELY RULE
OUT A FEW HOURS OF LIFR CONDITIONS. CLOUDS SHLD SCATTER FRIDAY MID
MORNING.
&&
PREV DISCUSSION... /ISSUED 526 AM CDT THU MAR 15 2012/
SHORT TERM...THROUGH SATURDAY NIGHT. PRIMARY FORECAST CONCERNS
ARE STRATUS AND FOG TRENDS...TEMPERATURES...AND WHETHER ANY
THUNDERSTORM CHANCES ARE NECESSARY DURING THE NEXT 72 HOURS. IN
SHORT...LEFT FORECAST FAIRLY SIMILAR TO PREVIOUS ONE...WITH NO
OFFICIAL PRECIPITATION MENTION AND A CONTINUATION OF MUCH-ABOVE
NORMAL TEMPERATURES.
09Z OBJECTIVE SURFACE ANALYSIS AND AUTOMATED OBS REVEAL A WEAK
SURFACE PRESSURE GRADIENT ACROSS THE CWA...WITH MOST PLACES
REPORTING VARIABLE TO LIGHT EASTERLY BREEZES. HOWEVER...A SHARP
TEMPERATURE/DEWPOINT GRADIENT IS VERY EVIDENT ALONG AN AXIS FROM
SOUTHWEST KANSAS TO FAR SOUTHEAST NEBRASKA...JUST BARELY SKIRTING
THE EDGES OF THE CWA AT THIS HOUR. THIS DIVIDING LINE IS ESSENTIALLY
A WEAK WARM FRONT...EXTENDING NORTHEAST FROM A WEAK LOW IN
SOUTHWEST KANSAS. FOR EXAMPLE...DEWPOINTS RANGE FROM ONLY 39 AT
HEBRON TO 59 AT CONCORDIA...ONLY TWO COUNTIES APART. AS HAS BEEN
THE CASE FOR SEVERAL NIGHTS NOW...TEMPS ACROSS MUCH OF THE CWA
HAVE SNUCK BELOW PREVIOUSLY FORECAST LOWS...WITH MOST PLACES IN
THE 40S...BUT TYPICAL COLD SITES SUCH AS ORD ALL THE WAY INTO THE
LOW 30S. TURNING TO 11-3.9 MICRON SATELLITE IMAGERY...A SWATH OF
LOW STRATUS HAS BEEN BLOSSOMING ACROSS NORTHERN KS INTO SOUTHEAST
NEB OVER THE PAST FEW HOURS...AS GENERALLY CAPTURED BY THE 900MB
RH FIELDS FROM THE 06Z NAM. DESPITE OBJECTIVE RUC ANALYSIS
INDICATING THAT AT LEAST 1000 J/KG MUCAPE HAS LIFTED INTO THE
SOUTHERN CWA...LACK OF FORCING AND CAPPING HAS PRECLUDED ANY
SHOWER/THUNDERSTORM DEVELOPMENT IN OR NEAR THE CWA. WATER VAPOR
IMAGERY AND SHORT TERM MODEL DATA INDICATES A PERSISTENT WEST-
SOUTHWEST FLOW ALOFT...WITH NO MAJOR SHORTWAVES IN THE FLOW EXCEPT
FOR ONE WELL OFF TO THE NORTHWEST ENTERING BRITISH COLUMBIA.
STARTING OFF WITH THE VERY SHORT TERM...MAIN CHALLENGE IS EXTENT
OF STRATUS DEVELOPMENT THIS MORNING...AND WHETHER ANY IMPACTFUL
FOG WILL JOIN THE FRAY AS WELL. FOLLOWED NAM 950-900MB RH FIELDS
FAIRLY CLOSELY FOR SKY COVER THIS MORNING...WITH STRATUS RAPIDLY
EXPANDING NORTHEAST AND ENCOMPASSING MUCH OF THE SOUTHEAST 1/3 TO
1/2 OF THE CWA BY SUNRISE. AS FOR FOG...PREVIOUS FORECAST ALREADY
HAD PATCHY WORDING...AND ACTUALLY EXPANDED THIS TO COVER A BIT
LARGER AREA...AS HRRR HAS INSISTED ON REDUCED VISIBILITIES ACROSS
MUCH OF THE SAME AREAS AS THE EXPANDING STRATUS. JUST WITHIN PAST
HOUR...BELOIT HAS NOW DROPPED TO 1/2 MILE VSBY. OBVIOUSLY TEMP
TRENDS TODAY WILL BE HIGHLY DEPENDENT ON STRATUS TRENDS...WITH NAM
SOUNDING INDICATING THAT SOUTHEAST AREAS COULD POTENTIALLY HOLD
ONTO STRATUS THROUGH AT LEAST MUCH OF THE MORNING HOURS BEFORE
MIXING OUT COMMENCES. CERTAINLY CONFIDENCE IS LOW IN THE HOURLY
TRENDS...BUT PER MET/MAV GUIDANCE CONSENSUS...NUDGED DOWN HIGHS A
FEW DEGREES FROM PREVIOUS FORECAST MOST AREAS...WITH NEARLY THE
ENTIRE CWA IN A FAIRLY UNIFORM 76-79 RANGE. AS FOR CONVECTIVE
CHANCES...MODELS HAVE BACKED OFF YET AGAIN ON SUGGESTION FROM 24
HOURS AGO OF POSSIBLE CONVECTION THIS AFTERNOON/EVENING IN THE
EASTERN CWA...AND DESPITE PRESENCE OF 1000-2000 J/KG MLCAPE
BUILDING INTO EASTERN AREAS THIS AFTERNOON...LACK OF FORCING AND A
DECENT CAPPING INVERSION SHOULD KEEP STORMS AT BAY AND THUS LEFT
DRY. A POTENTIALLY BETTER RISK FOR ISOLATED/SCATTERED CONVECTION
WILL RESIDE A FEW COUNTIES EAST OF THE CWA WITHIN NORTHEAST KS AND
FAR SOUTHEAST NEB PER THE 00Z 4KM WRF-NMM. BREEZES TODAY WILL
REMAIN FAIRLY LIGHT WITH A BROAD SURFACE TROUGH AXIS DRAPED
THROUGH FROM NORTH-SOUTH...SEPARATING A NORTHERLY COMPONENT IN THE
WEST FROM A SOUTHERLY ONE IN THE WEST. WHILE DEWPOINTS ACROSS MUCH
OF THE SOUTHEAST 2/3 OF THE CWA WILL BE ON THE INCREASE
TODAY...THE WEST WILL LIKELY REMAIN RATHER DRY AND THUS CARRY AN
ELEVATED FIRE THREAT TO SOME EXTENT. SEE FIRE WEATHER DISCUSSION
BELOW.
TONIGHT...KEPT IT DRY WITH FORCING REMAINING NEGLIGIBLE. WITH
BREEZES REMAINING LIGHT OVERNIGHT...AND PLENTY OF LOW LEVEL
MOISTURE AROUND...INTRODUCED ANOTHER ROUND OF PATCHY FOG WORDING
MAINLY ACROSS THE SOUTHEAST 2/3 OF THE CWA. WITH VARIOUS
MODELS/GUIDANCE SUCH AS MET/MAV AND ALSO SREF VISIBILITY
PROBABILITIES PICKING UP ON A FOG SIGNAL...WOULD NOT BE SURPRISED
TO SEE AT LEAST A FEW HOURS OF LOCALLY DENSE DEVELOPMENT...BUT
WILL START WITH GENERIC PATCHY FOR NOW. LEFT LOW TEMPS TONIGHT
SIMILAR TO PREVIOUS FORECAST RANGING FROM LOW 40S FAR WEST TO LOW
50S EAST...BUT WOULD NOT BE SURPRISED TO SEE A FEW WESTERN AREAS
AGAIN SETTLE INTO THE 30S IF THE AIR REMAINS DRY ENOUGH.
FRIDAY...THE FIRST POTENTIAL ISSUE WILL THE EXTENT OF ANY MORNING
STRATUS/FOG...ALTHOUGH A SLOWLY STRENGTHENING HIGH PLAINS LEE
TROUGH WILL INDUCE A BIT STRONGER SOUTHERLY BREEZE...WHICH SHOULD
HELP TO MIX OUT ANY FOG BY MID TO LATE MORNING IF IT DOES IN FACT
MATERIALIZE. INSTABILITY WILL AGAIN CLIMB ACROSS EASTERN ZONES
DURING THE AFTERNOON...BUT FORECAST SOUNDINGS AND PLAN VIEW PROGS
SHOW A HEALTHY CAP TO NEAR-SURFACE BASED CONVECTION AND THUS LEFT
OUT MENTION OF STORMS DURING THE DAY AND ALSO INTO THE
NIGHT...ALTHOUGH THE NIGHT PERIOD WILL NEED WATCHED AS LOW LEVEL
JET RAMPS UP. IN FACT...06Z NAM HINTS AT POSSIBLE ISOLATED STORM
DEVELOPMENT JUST EAST OF THE CWA AT SOME POINT FRIDAY NIGHT...BUT
CONFIDENCE IS LOW GIVEN RECENT TRENDS OF CONVECTIVE SIGNALS NOT
PANNING OUT. CHANGED FRIDAY HIGH TEMPS LITTLE FROM BEFORE...WITH
NEAR 80 IN NEB ZONES AND LOW-MID 80S IN KS.
SATURDAY/SATURDAY NIGHT...THE FLOW ALOFT STARTS TURNING MORE
SOUTH-SOUTHWESTERLY IN RESPONSE TO A DEEP...HIGH AMPLITUDE TROUGH
FINALLY COMING ONSHORE ACROSS THE WESTERN CONUS. ALTHOUGH FORECAST
SOUNDINGS CONTINUE TO SHOW AIRMASS CAPPED TO CONVECTIVE
POTENTIAL...THERE ARE HINTS IN MODELS SUCH AS THE ECMWF/GFS THAT
STRATUS AND POSSIBLE DRIZZLE COULD AFFECT EASTERN ZONES DURING
THIS TIME FRAME. LEFT DRY FOR NOW HOWEVER. THE MAIN STORY SATURDAY
WILL BE INCREASING SOUTHERLY BREEZES...WITH SUSTAINED SPEEDS
LIKELY INTO THE 20-25 MPH RANGE ACROSS MUCH OF THE CWA WITH HIGHER
GUSTS. AS FOR TEMPS...SURE ENOUGH...ANOTHER DAY OF UPPER
70S-LOW 80S LOOKS IN STORE.
IN CLOSING...ALTHOUGH RISK OF CONVECTION IS CERTAINLY NOT NIL
ACROSS THE CWA DURING THE NEXT FEW DAYS...DEGREE OF CAPPING AND
LACK OF FORCING PRECLUDES FORMAL MENTION OF EVEN SLIGHT CHANCES
FOR NOW...WITH LOCATIONS GENERALLY 100-200 MILES EAST-SOUTHEAST OF
THE CWA MORE FAVORED FOR AT LEAST LIMITED STORM COVERAGE DURING
THIS TIME FRAME.
LONG TERM...SUNDAY THROUGH WEDNESDAY. THIS WILL CONTINUE TO BE AN
UNSEASONABLY WARM PERIOD. IN ADDITION...THUNDERSTORMS WILL ALSO BE
POSSIBLE AS A VERY DEEP UPPER LEVEL TROUGH DIGS ACROSS THE WESTERN
CONUS.
THIS PATTERN WILL ALLOW MOISTURE RICH AIR TO FLOW NORTH THROUGH THE
PLAINS IN ADVANCE OF THE DEEPENING WESTERN CONUS TROUGH. THE
COMBINATION OF RICH SFC MOISTURE AND STRONG UPPER LEVEL WINDS AND
SHEAR WILL LIKELY RESULT IN SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE GREAT PLAINS.
THE MOST LIKELY TIME FRAME FOR STRONG TO SEVERE THUNDERSTORMS OVER
CENTRAL NEBRASKA AND CENTRAL KANSAS WILL BE MONDAY AND TUESDAY. A
FAIRLY STRONG CAP ON SUNDAY WILL BE DIFFICULT TO OVERCOME GIVEN THAT
THE BETTER FORCING ASSOCIATED WITH THE UPPER SYSTEM WILL STILL BE
WELL OFF TO THE WEST ON SUNDAY. THE SYSTEM SHOULD THEN EITHER BE
EAST OF OUR CWA OR BECOME A CUT OFF LOW TO OUR SOUTH BY
WEDNESDAY...NEITHER OF THESE SCENARIOS WOULD BE VERY FAVORABLE FOR
THUNDERSTORMS. CONSEQUENTLY...IT APPEARS THAT MONDAY AND TUESDAY
WILL BE THE MOST FAVORABLE DAYS FOR THUNDERSTORMS INCLUDING THE
POTENTIAL FOR SOME SEVERE THUNDERSTORMS DEPENDING ON HOW FAR
EAST/WEST THE DRY LINE SETS UP. THE LATEST MODEL RUNS CONTINUE TO
SEEM TO BE TOO FAST WITH THIS SYSTEM. THE 00Z GFS AND ECMWF ARE BOTH
FASTER/FURTHER EAST WITH THE UPPER TROUGH THAN THE 00Z ENSEMBLE
MEAN. IN ADDITION...THIS KIND OF PATTERN WITH A LARGE BLOCKING RIDGE
ACROSS THE EASTERN CONUS WILL TYPICALLY SLOW SYSTEM PROGRESSION DOWN
MORE THAN THE FORECAST MODELS ACCOUNT FOR. THEREFORE...EXPECT A
POTENTIALLY STORMY START TO NEXT WEEK...ESPECIALLY IN THE MONDAY
AND/OR TUESDAY TIME FRAME.
FIRE WEATHER...ALTHOUGH WIND SPEEDS TODAY SHOULD FALL WELL SHORT
OF OFFICIAL RED FLAG WARNING CRITERIA OF 20 MPH SUSTAINED/25 MPH
GUST...LATEST 06Z NAM SUGGESTS THAT DEWPOINTS ACROSS GENERALLY THE
NORTHWEST 1/3 OF THE CWA WILL CHECK IN A BIT LOWER THAN PREVIOUSLY
EXPECTED...AND QUITE A BIT LOWER THAN VALUES ACROSS THE SOUTHEAST
1/2 OF THE CWA WHERE DEWPOINTS SHOULD STEADILY INCREASE. THE NET
RESULT IS AFTERNOON RELATIVE HUMIDITY VALUES TUMBLING TO AROUND 20
PERCENT ACROSS A HANDFUL OF FAR WESTERN/NORTHWEST COUNTIES THIS
AFTERNOON...WHILE MUCH HIGHER RH VALUES 40-50 PERCENT RESIDE
ACROSS MUCH OF THE EASTERN CWA. DESPITE THE FAIRLY LIGHT WINDS...THE
GRASSLAND FIRE DANGER STATEMENT...RFDGID...CALCULATED EXTREME FIRE
DANGER CATEGORY FOR DAWSON AND GOSPER COUNTIES FOR THIS
AFTERNOON...WITH SEVERAL BORDERING COUNTIES IN THE VERY HIGH
CATEGORY. LOOKING AHEAD A FEW DAYS...INCREASED DEWPOINTS AND THUS
RH VALUES SHOULD INVADE EVEN WESTERN COUNTIES ON FRIDAY AND
SATURDAY...THUS KEEPING RH ABOVE 20 PERCENT. HOWEVER...AN
EFFECTIVE NORTH-SOUTH DRYLINE WILL SET UP JUST WEST OF THE
CWA...MEANING THAT WESTERN COUNTIES COULD LIE VERY CLOSE TO A
SHARP MOISTURE GRADIENT ON THOSE DAYS AND FLIRT WITH DROPPING
BELOW 20 PERCENT RH. GIVEN THAT SOUTH WINDS WILL ALSO BE ON THE
INCREASE...WILL NEED TO CLOSELY WATCH WESTERN FRINGE OF CWA FOR
FIRE WEATHER ISSUES...WHILE THE MAJORITY OF THE CWA SHOULD BE IN
BETTER SHAPE THAN LATELY WITH THE ARRIVAL OF HIGHER DAYTIME DEWPOINTS
IN THE 40S AND 50S.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
612 PM EDT THU MAR 15 2012
.SYNOPSIS...
THE LARGE SCALE PATTERN WILL BE DOMINATED BY AN UPPER RIDGE WHICH
WILL KEEP US WARMER THAN NORMAL RIGHT INTO NEXT WEEK. A SLOW
MOVING WARM FRONT WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TODAY INTO FRIDAY. HIGH PRESSURE WILL WORK BACK IN
FOR THE WEEKEND AND LAST INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
REGIONAL RADAR SHOWS SCATTERED SHRA OVR THE SC MTNS SLOWLY MOVING
EASTWARD AND DISSIPATING...AS THEY ENCOUNTER BACK DOOR COLD FRONT
SWEEPING WEST FROM THE SUSQ VALLEY. FOCUS IN THE NEAR TERM WILL
SHIFT TOWARD THE EASTERN GRT LKS...WHERE CONVECTION IS ERUPTING IN
VICINITY OF WEAK LOW PRES SYSTEM AND ASSOC COLD FRONT. SEEMS THE
BEST CHANCE OF SHWRS AND STORMS OVERNIGHT WILL BE ACROSS NW
PA...AS THIS WEAK LO PRES SYS TRACKS ACROSS LK ERIE.
BACK DOOR COLD FRONT WILL PRESS WESTWARD OVERNIGHT...BRINGING A
COOLER/MARITIME AIR MASS...AND POSS STRATUS DECK LATE TONIGHT...INTO MUCH
OF CENTRAL PA EAST OF THE ALLEGHENIES. HOWEVER...LL JET WILL
TRANSPORT INCREASING MOIST/UNSTABLE AIR ALOFT OVR THE
REGION...BRINGING THE CHC OF SCT SHRA EVEN TO THE EASTERN HALF OF
THE STATE LATE TONIGHT.
HAVE LOWERED MIN TEMPS OVERNIGHT ACROSS THE SUSQ VALLEY BASED ON
UPSTREAM READINGS AND LATEST NAM12 BLYR TEMP FCST. STILL LOOKS
LIKE A VERY MILD NIGHT EVERYWHERE...WITH LOWS RANGING FROM THE
M/U50S ACROSS THE W MTNS...TO THE MID 40S EAST OF THE SUSQ RIVER.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE REGION FRIDAY
KEEPING THE LOCAL AREA UNSETTLED...WITH A CHANCE FOR SHOWERS AND
TSTMS IN THE FCST. ACTIVITY SHUD TAPER OFF FROM NW TO SE DURING
THE LAST HALF OF THE DAY AS THE SYSTEM EXITS THE REGION.
MILD TEMPERATURES WILL CONTINUE...THOUGH MAYBE NOT AS WARM AS
TODAY...HIGHS WILL TOP OUT IN THE MID 60S TO MID 70S WHICH IS
STILL 15-25 DEG ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
NOT A LOT OF CHANGE FROM RECENT DAYS.
HUGE RIDGE WILL CONTROL THE WEATHER WELL INTO NEXT WEEK...
AS A VERY DEEP TROUGH DIGS SOUTHWARD ACROSS THE FAR WEST...
WITH THE ZERO LINE AT 850 MB SOUTH OF CA.
ANY REMAINING CONVECTION WILL BE OUT OF THE AREA BY OR
SHORTLY 00Z SAT.
THERE COULD BE A SHOWER OR THUNDERSTORM AT ANY POINT...
MAINLY AFTERNOON AND THE EARLY EVENING HOURS...ACROSS
THE REGION SUNDAY AFTERNOON INTO THU...BUT LEFT FCST DRY...
AS NOTHING REALLY FOCUS ACTIVITY ON.
ASIDE FROM THE WEEKEND...WHERE TEMPS WILL BE A FEW DEGREES
COOLER...MAINLY ACROSS THE FAR EAST...WTIH SE FLOW...
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL. EVEN FOR THE
WEEKEND...TEMPS WILL STILL BE ABOVE NORMAL. WENT ABOVE
GUIDANCE. ENJOY.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
HIGH CLOUDS CONTINUE TO BLEED INTO THE LOCAL AREA OFF THE DYING
UPSTREAM CONVECTION. THE SHOWERS OVER THE NW ARE FADING FAST.
CHANCES FOR THUNDER TO REACH OUR NW TERMINALS SEEMS TO BE
DIMINISHING IN THE SHORT TERM...AT LEAST FOR THE NEXT 3-6 HOURS.
THE REST OF THE DAY INTO THE EVENING WILL BE SEE MOISTURE AND
INSTABILITY CONTINUE TO GRADUALLY INCREASE...MAINLY OVER WESTERN
AREAS. SHORT RANGE MODELS CONTINUE THE IDEA OF SOME CONVECTION
DEVELOPING UPSTREAM AND TRACKING OVER THE REGION
OVERNIGHT...ESPECIALLY THE HRRR AND HIGH RES ARW. EXPECT MORE
WIDESPREAD MVFR/IFR TO DEVELOP AS THE MOIST AIR AND PRECIP MOVE
ACROSS OVERNIGHT INTO EARLY FRIDAY.
FRIDAY WILL START OFF WITH MOST TERMINALS MVFR/IFR...WITH
CONDITIONS GRADUALLY IMPROVING AS THE DAY WEARS ON. THINK MOST OF
THE AREA WILL LIFT UP TO VFR BY AFTERNOON.
OUTLOOK...
SAT-TUE...VFR...WITH BRIEF REDUCTIONS POSSIBLE IN SCT
SHOWERS/ISOLD TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
336 PM EDT THU MAR 15 2012
.SYNOPSIS...
THE LARGE SCALE PATTERN WILL BE DOMINATED BY AN UPPER RIDGE WHICH
WILL KEEP US WARMER THAN NORMAL RIGHT INTO NEXT WEEK. A SLOW
MOVING WARM FRONT WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TODAY INTO FRIDAY. HIGH PRESSURE WILL WORK BACK IN
FOR THE WEEKEND AND LAST INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
REGIONAL RADAR SHOWS SCATTERED CONVECTION SLOWLY MOVING EASTWARD
AND DISSIPATING. RUC MESO ANAL SHOWS THAT MID LEVEL LAPSE RATES
HAVE ACTUALLY DECREASED A BIT WITH A PRETTY ROBUST CAP REMAINING
OVER MOST OF THE AREA. MOST HUMID AND UNSTABLE AIRMASS REMAINS
OVER OHIO AND FAR WESTERN PA...WITH THE SHORT RANGE MODELS
CONTINUING TO ADVECT THE INSTABILITY EASTWARD LATER TODAY AND
TONIGHT.
HAVE DOWNPLAYED THE NEAR TERM CHANCES FOR RAIN THROUGH LATE DAY TO
BETTER MATCH THE SHORT TERM GUIDANCE AND TRENDS. SEEMS THE BEST
CHANCE TO TRACK SOME SHOWERS AND STORMS ACROSS WILL BE OVERNIGHT
AS CONVECTION THAT IS EXPECTED TO FIRE OVER OHIO AND THE LOWER
LAKES GETS STEERED ACROSS OUR FCST AREA.
USED THE SREF MIN TEMPS TONIGHT WHICH ARE WARMER THAN GMOS AND
LOOK MORE REASONABLE OVER MOST OF THE AREA. I MAY BE A LITTLE WARM
OVER THE FAR SE WHERE A MARITIME FLOW HAS DEVELOPED AND MAY ALLOW
MINS TO DROP BELOW 50. OTHERWISE THE MAJORITY OF THE FCST AREA WILL
BE VERY MILD...AVERAGING 20-30 DEG ABOVE NORMAL FOR THE WANING DAYS
OF WHAT HAS BEEN A VERY UNEVENTFUL WINTER.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
A WEAK BACK DOOR COLD FRONT WILL DROP SOUTH ACROSS THE REGION
FRIDAY KEEPING THE LOCAL AREA UNSETTLED...WITH A CHANCE FOR
SHOWERS AND TSTMS IN THE FCST. ACTIVITY SHUD TAPER OFF FROM NW TO
SE DURING THE LAST HALF OF THE DAY AS THE SYSTEM EXITS THE REGION.
MILD TEMPERATURES WILL CONTINUE...THOUGH MAYBE NOT AS WARM AS
TODAY...HIGHS WILL TOP OUT IN THE MID 60S TO MID 70S WHICH IS
STILL 15-25 DEG ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
NOT A LOT OF CHANGE FROM RECENT DAYS.
HUGE RIDGE WILL CONTROL THE WEATHER WELL INTO NEXT WEEK...
AS A VERY DEEP TROUGH DIGS SOUTHWARD ACROSS THE FAR WEST...
WITH THE ZERO LINE AT 850 MB SOUTH OF CA.
ANY REMAINING CONVECTION WILL BE OUT OF THE AREA BY OR
SHORTLY 00Z SAT.
THERE COULD BE A SHOWER OR THUNDERSTORM AT ANY POINT...
MAINLY AFTERNOON AND THE EARLY EVENING HOURS...ACROSS
THE REGION SUNDAY AFTERNOON INTO THU...BUT LEFT FCST DRY...
AS NOTHING REALLY FOCUS ACTIVITY ON.
ASIDE FROM THE WEEKEND...WHERE TEMPS WILL BE A FEW DEGREES
COOLER...MAINLY ACROSS THE FAR EAST...WTIH SE FLOW...
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL. EVEN FOR THE
WEEKEND...TEMPS WILL STILL BE ABOVE NORMAL. WENT ABOVE
GUIDANCE. ENJOY.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
HIGH CLOUDS CONTINUE TO BLEED INTO THE LOCAL AREA OFF THE DYING
UPSTREAM CONVECTION. THE SHOWERS OVER THE NW ARE FADING FAST.
CHANCES FOR THUNDER TO REACH OUR NW TERMINALS SEEMS TO BE
DIMINISHING IN THE SHORT TERM...AT LEAST FOR THE NEXT 3-6 HOURS.
THE REST OF THE DAY INTO THE EVENING WILL BE SEE MOISTURE AND
INSTABILITY CONTINUE TO GRADUALLY INCREASE...MAINLY OVER WESTERN
AREAS. SHORT RANGE MODELS CONTINUE THE IDEA OF SOME CONVECTION
DEVELOPING UPSTREAM AND TRACKING OVER THE REGION
OVERNIGHT...ESPECIALLY THE HRRR AND HIGH RES ARW. EXPECT MORE
WIDESPREAD MVFR/IFR TO DEVELOP AS THE MOIST AIR AND PRECIP MOVE
ACROSS OVERNIGHT INTO EARLY FRIDAY.
FRIDAY WILL START OFF WITH MOST TERMINALS MVFR/IFR...WITH
CONDITIONS GRADUALLY IMPROVING AS THE DAY WEARS ON. THINK MOST OF
THE AREA WILL LIFT UP TO VFR BY AFTERNOON.
OUTLOOK...
SAT-TUE...VFR...WITH BRIEF REDUCTIONS POSSIBLE IN SCT
SHOWERS/ISOLD TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
206 PM EDT THU MAR 15 2012
.SYNOPSIS...
THE LARGE SCALE PATTERN WILL BE DOMINATED BY AN UPPER RIDGE WHICH
WILL KEEP US WARMER THAN NORMAL RIGHT INTO NEXT WEEK. A SLOW
MOVING WARM FRONT WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TODAY INTO FRIDAY. HIGH PRESSURE WILL WORK BACK IN
FOR THE WEEKEND AND LAST INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
REGIONAL RADAR SHOWS SCATTERED CONVECTION SLOWLY MOVING EASTWARD
AND DISSIPATING. RUC MESO ANAL SHOWS THAT MID LEVEL LAPSE RATES
HAVE ACTUALLY DECREASED A BIT WITH A PRETTY ROBUST CAP REMAINING
OVER MOST OF THE AREA. MOST HUMID AND UNSTABLE AIRMASS REMAINS
OVER OHIO AND FAR WESTERN PA...WITH THE SHORT RANGE MODELS
CONTINUING TO ADVECT THE INSTABILITY EASTWARD LATER TODAY AND
TONIGHT.
HAVE DOWNPLAYED THE NEAR TERM CHANCES FOR RAIN THROUGH LATE DAY TO
BETTER MATCH THE SHORT TERM GUIDANCE AND TRENDS. SEEMS THE BEST
CHANCE TO TRACK SOME SHOWERS AND STORMS ACROSS WILL BE OVERNIGHT
AS CONVECTION THAT IS EXPECTED TO FIRE OVER OHIO AND THE LOWER
LAKES GETS STEERED ACROSS OUR FCST AREA.
USED THE SREF MIN TEMPS TONIGHT WHICH ARE WARMER THAN GMOS AND
LOOK MORE REASONABLE OVER MOST OF THE AREA. I MAY BE A LITTLE WARM
OVER THE FAR SE WHERE A MARITIME FLOW HAS DEVELOPED AND MAY ALLOW
MINS TO DROP BELOW 50. OTHERWISE THE MAJORITY OF THE FCST AREA WILL
BE VERY MILD...AVERAGING 20-30 DEG ABOVE NORMAL FOR THE WANING DAYS
OF WHAT HAS BEEN A VERY UNEVENTFUL WINTER.
&&
.SHORT TERM /FRIDAY/...
A WEAK BACK DOOR COLD FRONT WILL DROP SOUTH ACROSS THE REGION
FRIDAY KEEPING THE LOCAL AREA UNSETTLED...WITH A CHANCE FOR
SHOWERS AND TSTMS IN THE FCST. ACTIVITY SHUD TAPER OFF FROM NW TO
SE DURING THE LAST HALF OF THE DAY AS THE SYSTEM EXITS THE REGION.
MILD TEMPERATURES WILL CONTINUE...THOUGH MAYBE NOT AS WARM AS
TODAY...HIGHS WILL TOP OUT IN THE MID 60S TO MID 70S WHICH IS
STILL 15-25 DEG ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
RIDGE STRENGTHENS OVER THE REGION FRI NIGHT THROUGH SUNDAY. THIS
WILL KEEP TEMPERATURES UNSEASONABLY MILD...EVEN WITH LIGHT
NORTHERLY FLOW FRI NIGHT. RETURN FLOW BEGINS ANEW LATER SAT AS
HEIGHTS BEGIN TO BUILD...THOUGH SE FLOW COULD TEMPER MAXES A BIT
SAT. SHORTWAVE DOES SLIDE INTO THE OHIO VALLEY ON SUNDAY...WHICH
MAY KICK OFF ISOLATED SHOWERS/TSTMS IN LAUREL HIGHLANDS...BUT
OTHERWISE IT SHOULD REMAIN DRY THIS WEEKEND.
NOTICEABLY ABOVE NORMAL TEMPS WILL LINGER THROUGH NEXT WEEK...AS VERY
DEEP SYSTEM OVER THE WEST TRANSITIONS INTO A NEARLY STATIONARY
CLOSED LOW OVER THE MISSOURI VALLEY. PRECIP CHANCES REMAIN LOW...BUT
DO BEGIN TO INCREASE BY NEXT WEEKEND. TEMPERATURES REMAIN ABOUT 25F
ABOVE NORMAL.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
HIGH CLOUDS CONTINUE TO BLEED INTO THE LOCAL AREA OFF THE DYING
UPSTREAM CONVECTION. THE SHOWERS OVER THE NW ARE FADING FAST.
CHANCES FOR THUNDER TO REACH OUR NW TERMINALS SEEMS TO BE
DIMINISHING IN THE SHORT TERM...AT LEAST FOR THE NEXT 3-6 HOURS.
THE REST OF THE DAY INTO THE EVENING WILL BE SEE MOISTURE AND
INSTABILITY CONTINUE TO GRADUALLY INCREASE...MAINLY OVER WESTERN
AREAS. SHORT RANGE MODELS CONTINUE THE IDEA OF SOME CONVECTION
DEVELOPING UPSTREAM AND TRACKING OVER THE REGION
OVERNIGHT...ESPECIALLY THE HRRR AND HIGH RES ARW. EXPECT MORE
WIDESPREAD MVFR/IFR TO DEVELOP AS THE MOIST AIR AND PRECIP MOVE
ACROSS OVERNIGHT INTO EARLY FRIDAY.
FRIDAY WILL START OFF WITH MOST TERMINALS MVFR/IFR...WITH
CONDITIONS GRADUALLY IMPROVING AS THE DAY WEARS ON. THINK MOST OF
THE AREA WILL LIFT UP TO VFR BY AFTERNOON.
OUTLOOK...
SAT-TUE...VFR...WITH BRIEF REDUCTIONS POSSIBLE IN SCT
SHOWERS/ISOLD TSTMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
120 PM CDT THU MAR 15 2012
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH FRIDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A SURFACE COLD
FRONT STRETCHING FROM LA CROSSE TO DOOR COUNTY EARLY THIS MORNING
AND SLOWLY SLIDING TO THE SOUTHEAST. WIDELY SCATTERED CONVECTION
FINALLY DEVELOPED ALONG THE FRONT ACROSS SOUTHEAST WISCONSIN AND
NORTHERN ILLINOIS...AND A FEW CELLS MAY GRAZE SHEBOYGAN COUNTY.
FARTHER NORTH...4-6KFT CLOUDS HAVE BEEN EXPANDING OVER NORTHEAST
WISCONSIN AND LAKE MICHIGAN WHILE PATCHY DENSE FOG HAS DEVELOPED
OVER CENTRAL WISCONSIN. AS NORTH TO NORTHEAST WINDS DEVELOP BEHIND
THE FRONT EARLY THIS MORNING...ANTICIPATING THE FOG TO DISSIPATE WITH
MOST OF IT GONE BY THE MORNING COMMUTE. WITH THE FRONT SETTLING TO
THE SOUTH TODAY...MAIN FORECAST CONCERNS REVOLVE AROUND SKY
CONDITIONS...FOG POTENTIAL...AND TEMPS.
TODAY...SURFACE COLD FRONT WILL SETTLE ACROSS THE SOUTHERN GREAT
LAKES TODAY WHILE HIGH PRESSURE MOVES ACROSS LAKE SUPERIOR. 850MB
FRONT WILL LAG TO THE NORTH OVER NORTHERN WISCONSIN...WHICH WILL
KEEP AMPLE MOISTURE IN THE 925-850MB LAYER. BEHIND THE
FRONT...SURFACE WINDS WILL TURN NE TO EASTERLY WHICH WILL ADVECT A
SHALLOW MARINE AIRMASS OVER MUCH OF NE WISCONSIN AND PARTIALLY INTO
CENTRAL WISCONSIN. PROGGED SOUNDINGS THIS MORNING ARE FOLDED
OVER...WITH THE RESIDUAL WARM AIRMASS LAYING OVER TOP THE RELATIVELY
COLDER MARINE AIRMASS...SUGGESTING A LAYER OF STRATUS OR FOG COULD
POSSIBLY FORM. THINK THIS PROCESS IS UNDER WAY OVER NORTHERN LAKE
MICHIGAN AS INDICATED BY THE GROWING DARK BLOB ON THE SATELLITE.
WILL INCREASE SKY COVER OVER MUCH OF NE AND E-C WISCONSIN...AND SOME
OVER CENTRAL WISCONSIN TOO FOR THIS MORNING. THINK THIS WILL EVOLVE
INTO A CU DECK WITH HEATING FOR THE AFTERNOON WITH PARTIAL CLEARING
ANTICIPATED. OVER N-C WISCONSIN...A VERY DRY AIRMASS WILL PUSH IN
FROM LAKE SUPERIOR...WITH DEWPOINTS TANKING ONCE AGAIN...WHICH WILL
SET UP A FAIRLY TIGHT DEWPOINT GRADIENT ACROSS THE FORECAST AREA.
CLOUDS AND AN EAST WIND WILL COOL TEMPS DOWN TODAY...AND WILL RANGE
FROM THE UPPER 50S NORTH TO UPPER 60S SOUTH...LOCALLY COOLER NEAR
LAKE MICHIGAN AND THE BAY OF GREEN BAY.
TONIGHT...VERY LITTLE CHANGES INTO TONIGHT. LIGHT RETURN FLOW WILL
BOW THE FRONT NORTHWARD INTO THE NORTHERN MISSISSIPPI VALLEY...WHILE
WE WILL STILL SEE LIGHT EAST FLOW NORTH OF THE BOUNDARY OVER
NORTHERN WISCONSIN. PROGGED SOUNDINGS INDICATE A SIMILAR INVERSION
DEVELOPING TONIGHT WITH A SHALLOW COOL AIRMASS IN PLACE. EVENING
HIGH CLOUDS WILL DEPART BY EARLY IN THE OVERNIGHT PERIOD...WHICH
WILL SUPPORT COOLING IN THE LOW LEVELS AND THE POSSIBILITY OF
STRATUS/FOG REFORMING. WILL INCREASE SKY COVER OVER NORTHEAST
WISCONSIN AND KEEP A MENTION OF PATCHY FOG IN THE FORECAST. LOWS
RANGING FROM THE MID 30S NORTH TO MID 40S SOUTH.
FRIDAY...THE FRONT WILL CONTINUE TO LIFT SLOWLY NORTHWARD ON
FRIDAY...POSSIBLY REACHING INTO CENTRAL WISCONSIN BY LATE IN THE
AFTERNOON. WITHOUT A GOOD PUSH ALOFT THOUGH...SOUTHEAST WINDS AT
THE SURFACE WILL KEEP THE SHALLOW MARINE AIR IN PLACE OVER THE REST
OF THE FORECAST AREA. MOISTURE IN THE 850-750MB LAYER WILL TRY TO
ROTATE INTO CENTRAL WISCONSIN AND THE NAM CREATES SOME ELEVATED CAPE
UP TO AROUND 700 J/KG IN THE AFTERNOON. IF THIS PANS OUT...NOT
SEEING A STRONG ENOUGH TRIGGER TO INITIATE CONVECTION...SO WILL
STICK WITH A DRY FORECAST. HIGHS RANGING FROM THE LOW 50S EAST TO
THE LOWER 70S WEST.
.LONG TERM...FRIDAY NIGHT THRU WEDNESDAY. MAIN FORECAST CONCERNS
ARE DEALING WITH CLOUD/FOG POTENTIAL...TEMPS...AND PRECIP CHANCES.
SUMMER-LIKE PATTERN TO CONTINUE INTO EARLY NEXT WEEK AS UPPER
RIDGE BUILDS ACROSS THE EASTERN CONUS...KEEPING TEMPS WELL ABOVE
NORMAL. AMAZING STRETCH OF LOW/MID 70S ARE EXPECTED SATURDAY
THROUGH TUESDAY...WITH RECORD HIGHS LIKELY. ONLY LOCATIONS NOT
PARTICIPATING IN THE VERY WARM AIR MASS WILL BE NEAR LAKE
MICHIGAN...WHERE TEMPS WILL STRUGGLE TO GET TO 60.
PRECIP CHANCES FAIRLY LOW AS WEAK DISTURBANCES STILL FORECAST TO
RIDE THE BACK SIDE OF THE EASTERN U.S. RIDGE. STILL TOUGH TO TIME
OUT THESE SMALL/WEAK DISTURBANCES THIS FAR IN ADVANCE. SO
CONFIDENCE REMAINS LOW ON THE TIMING/LOCATION OF THESE AND IF
THEY WILL BE ABLE TO GENERATE ANY SHOWER/STORM ACTIVITY. BEST
DISTURBANCE STILL LOOKS TO CROSS INTO THE GREAT LAKES SOMEWHERE
AROUND THE SATURDAY NIGHT TIME FRAME. MODELS HAVE DRIFTED A LITTLE
EAST WITH THIS FEATURE...KEEPING THE MAJORITY OF PRECIP IN LOWER
MICHIGAN. DUE TO THE TIMING/LOCATION CONCERNS...AND LACK OF UPPER
LEVEL SUPPORT...WILL KEEP SLIGHT CHANCE POPS FROM FRIDAY NIGHT
INTO SATURDAY NIGHT TO COVER SMALL THREAT OF SOME PRECIP ACTIVITY.
BY SUNDAY...THE UPPER RIDGE BUILDS OVER THE AREA TO KEEP PRECIP
CHANCES TO THE WEST...CLOSER TO THE DEEP UPPER TROUGH CROSSING
INTO THE PLAINS. THIS SYSTEM WILL BRING A DECENT CHANCE OF
SHOWERS/STORMS TO THE AREA MID-WEEK. STILL SOME DISAGREEMENT WITH
HOW THE MODELS HANDLE THE TROUGH AS IT CUTS OFF IN THE MID-
MISSISSIPPI VALLEY. STILL PLENTY OF TIME TO WORK ON THE DETAILS
WITH THIS SYSTEM...BUT CHANCES FOR WIDESPREAD INCREASE BY
WEDNESDAY.
LAKE MICHIGAN SHOULD SLOWLY LOSE ITS INFLUENCE ON ALL BUT THE
IMMEDIATE LAKESHORE BY SATURDAY AS WINDS TURN MORE SOUTHERLY
BEHIND THE WARM FRONT PUSHING NORTH OF THE AREA. FOG COULD LINGER
ON/NEAR LAKE MICHIGAN THROUGH THE WEEKEND...HOWEVER WILL JUST
CARRY THE MENTION FOR FRIDAY NIGHT AND SATURDAY NIGHT FOR NOW.
&&
.AVIATION...UNCERTAINTY INVOLVING CIGS AND VSBYS AGAIN TODAY. AN
AREA OF MVFR CIGS AROUND CWA/AUW SEEMED TO BE EXPANDING WHILE THE
MVFR CIGS AROUND ISW LOOKED TO BE SHRINKING. GUIDANCE WAS
INDICATING LIFR IN FOG AT GRB AND AUW LATE TONIGHT/EARLY FRIDAY.
TIME/HEIGHT SECTIONS SHOWED PLENTY OF MOISTURE AT THE SURFACE
DURING THE NIGHT IN MOST AREAS INTO FRIDAY MORNING. KEEP A CLOSE
WATCH ON TRENDS AS FORECASTER CONFIDENCE IS LOW.
MG
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$