Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 04/02/12
AREA FORECAST DISCUSSION
NWS DENVER CO
929 PM MDT SUN APR 1 2012
.UPDATE...
&&
.SHORT TERM...COLD FRONT SHOULD REACH THE CO-WY BORDER BY MIDNIGHT
AND THEN MOVE RAPIDLY ACROSS THE PLAINS OVERNIGHT. WIND GUSTS TO
55 MPH WILL BE POSSIBLE BASED ON THE LATEST HRRR BY AROUND 12Z
OVER THE PLAINS.
.AVIATION...COLD FRONT SHOULD MOVE INTO THE AIRPORT IN THE 07Z-08Z
TIMEFRAME WITH GUSTY NORTH WINDS UP TO 40 MPH. COULD SEE A CHC OF
A RAIN/SNOW MIX AFTER 13Z HOWEVER AT THIS TIME DO NOT EXPECT ANY
SNOW ACCUMULATION.
&&
.PREV DISCUSSION... /ISSUED 210 PM MDT SUN APR 1 2012/
SHORT TERM...IT IS NOT QUITE AS GUSTY AS WE THOUGHT THIS
AFTERNOON...WE DO HAVE SOME WIND GUSTS INTO THE 20S IN THE
MOUNTAIN VALLEYS AND PALMER DIVIDE...AND RHS BELOW 15 PERCENT OVER
A LARGE AREA...SO WILL LEAVE RED FLAG WARNING IN PLACE.
TEMPERATURES HAVE CLIMBED INTO THE UPPER 70S AND LOWER 80S TODAY.
LOOKING AHEAD...SHOWERS IN UTAH WILL PROGRESS EASTWARD AND IMPACT
OUR MOUNTAINS TONIGHT...THIS WILL BE A MINOR STORM FOR THE
MOUNTAINS...WITH ONLY A COUPLE OF INCHES OF SNOW. THE COLD FRONT
IS STILL ON TRACK TO MOVE THROUGH NORTHEAST COLORADO TONIGHT.
WINDS BEHIND THE FRONT WILL BE 35-40 MPH WITH GUSTS INTO THE
50S...WITH A LOT OF LEAFING TREES DECIDED TO ISSUE A HIGH WIND
WARNING FOR A MARGINAL EVENT. THIS WILL BE FOR MUCH OF THE
PLAINS...EXPECT THE DENVER METRO AREA AND PALMER DIVIDE AND WILL
BE MORNING TO EARLY AFTERNOON...AS GRADIENT WEAKENS RAPIDLY
THROUGH THE AFTERNOON.
NEW NAM HAS COME INTO AGREEMENT ON THE MINOR UPSLOPE EVENT FOR
THE PALMER AND SOUTHERN FRONT RANGE FOOTHILLS MONDAY MORNING.
TEMPERATURES AT THE TIME WILL SUPPORT SNOW...AND GOOD UPSLOPE WILL
SUPPORT A FEW HOURS OF PRECIPITATION. AN INCH OF SNOW LOOKS LIKELY
IN THESE AREAS. FOR MUCH OF METRO DENVER IT LOOKS A BIT
WARMER...AND WE EXPECT SOME PRECIPITATION...BUT MORE OF A RAIN/
SNOW MIX IN THE EARLY MORNING. NAM DRIES OUT THE PLAINS...THE
OTHER MODELS SHOW SOME PRECIPITATION...WILL LEAVE THE SCATTERED
RAIN SHOWERS FOR AREAS SOUTH OF A DENVER TO AKRON LINE.
LONG TERM...ALTHOUGH DISCREPANCIES CONTINUE TO CROP UP IN THE
OVER TRACK OF THIS SLOW MOVING UPPER LOW...MOST HAVE THE SYSTEM
OVER NORTHEASTERN NEW MX SUNDAY NIGHT THEN SHIFT IT INTO
SOUTHEASTERN CO/OKLAHOMA PANHANDLE AREA ON TUESDAY. THE NAM12
CONTINUE WITH A DRIER MORE SOUTHERN SOLUTION. WITH THIS IN
MIND...WL GO WITH THE NORTHERN SOLUTION THAT APPEARS TO HAVE THE
BEST CONSENSUS. IF THIS PANS OUT...THEN THERE SHOULD BE A DECENT
PERIOD PRECIPITATION...ESPECIALLY OVER SOUTHERN AND EASTERN
PORTIONS OF THE CWFA MONDAY NIGHT AND TUESDAY. MONDAY NIGHT...
GUSTY NORTHERLY WINDS ARE PROGGED TO CONTINUE THROUGH THE EVENING
THEN GRADUALLY DECREASE. THE GFS MAINTAINS A NORTHERLY FLOW TO
ABOUT 700 MB MONDAY NIGHT WITH AN EASTERLY COMPONENT ABOVE IT.
SOME WEAK TO MODERATE MID LEVEL QG ASCENT IS PROGGED TO ADVECT
INTO THE AREA FROM THE SOUTHEAST. IT LOOKS LIKE AREAS IN AND NEAR
THE FRONT RANGE FOOTHILLS AND PALMER DIVIDE WOULD HAVE THE BEST
CHC OF MAINLY SNOW MONDAY NIGHT...WITH A MIX OF RAIN AND SNOW OVER
MOST OF THE URBAN CORRIDOR BELOW 5500 FEET. AS THE SYSTEM SHIFTS
TO THE NORTH AND EAST...THEN THE FOCUS FOR PCPN SHOULD SHIFT TO
THE NORTHEAST PLAINS. THE CHC OF PCPN WILL CONTINUE INTO TUESDAY
NIGHT...AS MOISTURE CONTINUES TO CIRCULATE AROUND THE NORTH AND
WEST SIDE OF THE UPPER LOW. IT WILL BE DRIER FOR WEDNESDAY
THROUGH FRIDAY...TEMPERATURES ARE PROGGED TO CLIMB BACK INTO THE
UPPER 60S AND LOWER 70S AT THAT TIME. BY FRIDAY AND SATURDAY...THE
NEXT TROUGH IS PROGGED TO DROP OUT OF THE PACIFIC NORTHWEST. THE
LATEST GFS MAINTAINS MORE OF OF WSWLY FLOW ALOFT OVER NORTHERN
CO...WHICH WOULD KEEP US ON THE DRY SIDE OF THE SYSTEM. IF THIS
CONCERNS...THEN MOST OF THE PCPN WILL BE CONFINED TO THE
MOUNTAINS.
AVIATION...EXPECT MORE SOUTH SOUTHWEST GUSTY WINDS UNTIL
SUNSET...THEN TRANSITIONING TO WEST WINDS THIS EVENING...
WITH THE COLD FRONT MOVING THROUGH AFTER MIDNIGHT ALONG WITH
NORTH WINDS GUSTING TO 30 MPH FOR LATE TONIGHT INTO MONDAY
MORNING. INCREASING UPSLOPE FLOW WILL RESULT IN AREAS OF IFR
CEILINGS AND SNOW AT APA...WITH A MIX OF RAIN AND SNOW AND MVFR
CEILINGS AND VISIBILITIES EXPECTED AT DIA AND BJC. AS TEMPERATURES
WARM UP AND THE UPSLOPE COMPONENT WEAKENS...CEILINGS WILL LIFT BY
MIDDAY BUT THERE WILL STILL BE SCATTERED RAIN SHOWERS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 4 AM TO NOON MDT MONDAY FOR COZ038-
042>051.
&&
$$
SHORT TERM...RTG
LONG TERM....COOPER
AVIATION...RPK
AREA FORECAST DISCUSSION...CORRECTION...
NWS DENVER/BOULDER CO
1052 AM MDT SAT MAR 31 2012
...CORRECTED TO ADD HIGHLIGHTS BELOW...
.UPDATE...CURRENT FORECASTS LOOK ON TRACK. LATEST RUC AS WELL AS
HRRR RUNS CONTINUE TO SUPPORT RED FLAG CONDITIONS ACROSS THE
FOOTHILLS OF SOUTHERN JEFFERSON AND DOUGLAS COUNTIES AS WELL AS
THE PALMER DIVIDE AND SOUTH PARK FOR THIS AFTERNOON AND EVENING.
BELIEVE THERE WILL BE ENOUGH MIXING TO GET GUSTS TO 30 MPH IN
THAT AREA. LOWER NORTH FORK FIRE AREA SHOULD SEE SOUTHERLY WINDS
IN THE 10-20 MPH RANGE PRIMARILY...ALONG WITH A FEW GUSTS TO
30 MPH. STILL SOME QUESTION WHETHER GUSTY WINDS WILL SPREAD
FURTHER NORTH ACROSS THE PLAINS. DESPITE MIXING...FEEL WINDS
SHOULD STAY BELOW CRITERIA. AS FOR TEMPERATURES...RECORD FOR
DENVER SHOULD BE BROKEN DESPITE HIGH LEVEL CLOUDS. AS FOR FIRE
WEATHER WATCH SUNDAY...LATEST GUIDANCE STILL SUGGESTING MARGINAL
CONDITIONS. HOWEVER...DESPITE COOLING IT LOOKS LIKE INCREASING
GRADIENT WILL BE ENOUGH FOR AN UPGRADE TO A WARNING. WILL LOOK
FURTHER INTO THIS SCENARIO LATER. DON`T THINK THAT AREA WILL NEED
TO BE EXPANDED.
&&
.AVIATION...CURRENT TAFS LOOKING ON TRACK. GUIDANCE STILL SHOWING
WINDS BECOMING MORE SOUTHEAST ACROSS THE AREA AIRPORTS THIS
AFTERNOON. LATEST RUC INDICATING A BIT MORE WIND...WILL INCREASE
THE SPEEDS A BIT AT APA AND DEN.
&&
.PREV DISCUSSION... /ISSUED 436 AM MDT SAT MAR 31 2012/
..CORRECTION TO THIRD PARAGRAPH...
SHORT TERM...NORTHWEST FLOW ALOFT TO SHIFT TO THE SOUTHWEST
TONIGHT AS AN UPPER LEVEL RIDGE PASSES OVER COLORADO. THIS RIDGE
WILL BRING VERY WARM TEMPERATURES FOR THIS TIME OF YEAR. AIRMASS
WILL BE ABOUT 5 DEGREES FAHRENHEIT WARMER THAN YESTERDAY. THIS
WILL PUT MOST LOCATIONS OVER NORTHEAST COLORADO IN THE UPPER 70S
TO MID 80S. THE RECORD FOR TODAY AT THE DENVER AIRPORT IS 80
DEGREES AND HAS A GOOD CHANCE OF BEING SURPASSED. HIGH CLOUDS WILL
MOVE OVER THE STATE AT TIMES TODAY. DOES NOT APPEAR THERE WILL BE
ENOUGH CLOUD TO AFFECT TEMPERATURES MUCH TODAY.
FIRE WEATHER...THE VERY WARM AND DRY CONDITIONS WILL KEEP
FUELS VERY DRY. MOST LOCATIONS WILL SEE RELATIVE HUMIDITIES BELOW
15 PERCENT TODAY. WINDS WILL BECOME BREEZY THIS AFTERNOON ACROSS
PARTS OF THE AREA. SOUNDINGS ACROSS THE AREA SHOW PEAK WINDS OF
20-30 KNOTS IN THE MIX LAYER THIS AFTERNOON. SO MAY SEE SOME GUST
OF 25-35 MPH MIX DOWN OVER PARTS OF THE HIGH COUNTRY AND EASTERN
PLAINS. A RED FLAG WARNING IS IN EFFECT FOR PARK COUNTY...THE
SOUTHERN FOOTHILLS AND THE PALMER DIVIDE. THE STRONGER WINDS LOOK
TO BE OVER PARK COUNTY AND SOUTHERN PARTS OF JEFFERSON AND
DOUGLAS COUNTIES WHERE GUSTS TO 30 MPH WILL BE POSSIBLE FOR A FEW
HOURS THIS AFTERNOON. WINDS WILL BE NOTHING LIKE THEY WERE THIS
PAST MONDAY WHEN THE LOWER NORTH FORK FIRE ROARED ACROSS THE
FOOTHILLS. THE WINDS ACROSS THE LOWER NORTH FORK FIRE THIS
AFTERNOON ARE EXPECTED TO BE 10 TO 20 MPH WITH A FEW GUSTS UP TO
30 MPH POSSIBLE. WILL NOT EXPAND THE RED FLAG WARNING FOR TODAY
BECAUSE THE WINDS WILL HARD TIME STAYING ABOVE THE 25 MPH
THRESHOLD FOR 3 HOURS.
LONG TERM...ONE MORE DAY OF UNSEASONABLY WARM AND DRY CONDITIONS
ESPLY EAST OF THE MTNS ON SUNDAY. MODELS CONTINUE TO EVOLVE THE
UPPER TROUGH TO OUR WEST ON SUNDAY. PAST FEW DAYS...ALL SORTS OF
SOLUTIONS HAVE COME FORTH...ALTHOUGH THE PAST FEW ITERATIONS HAVE
CONVERGED ON THE IDEA OF A DEEP TROUGH WITH A CLOSED LOW NEAR THE
FOUR CORNERS SUNDAY NIGHT. ON SUNDAY SOUTHWESTERLY FLOW ALOFT
STRENGTHENS THROUGH THE DAY AS THE PRESSURE GRADIENT ON THE PLAINS
TIGHTENS WITH PRESSURE AND HEIGHT FALLS WEST OF THE MTNS. AT PRESENT
TIME...A FIRE WEATHER WATCH IS OUT FOR THE SOUTHEAST QUADRANT OF THE
FORECAST AREA...SPECIFICALLY FOR THE SOUTHERN FOOTHILLS WEST OF
DENVER...DOUGLAS AND ELBERT COUNTIES...EASTERN PORTIONS OF ADAMS AND
ARAPAHOE COUNTIES...AND WASHINGTON COUNTY...AS WELL AS NORTH...
MIDDLE AND SOUTH PARKS. LATEST MODEL GUIDANCE WOULD SUPPORT THIS
AREA BEING UNDER A WATCH...ALTHOUGH WIND SPEEDS SUNDAY AFTERNOON
ONLY MARGINALLY STRONG ENOUGH. FOR NOW MUST CONSIDER LATER GUIDANCE
BEFORE UPGRADING THE WATCH TO A WARNING. OTHERWISE HIGHS ON SUNDAY
SLIGHTLY COOLER...OR LESS WARM THAN ON SATURDAY WITH MID 70S TO
LOWER 80S ON THE PLAINS. SHOULD HIGH CLOUD SHIELD THICKEN UP SOONER
THAN EXPECTED...MAY NOT GET INTO THE 80S. RECORD HIGH AT DENVER ON
SUNDAY IS 78. SHOULD COME CLOSE IF NOT EXCEED IT.
OVERNIGHT SUNDAY...AS THE UPPER TROUGH SHIFTS OVER WESTERN
COLORADO...MODELS SHOW A STRONG COLD FRONT SURGING SOUTH ALONG THE
FRONT RANGE PUSHED ALONG BY 25 TO 40 MPH NORTHERLY WINDS. BOUNDARY
LAYER STARTS OUT VERY DRY THAT EVENING BUT QUICKLY MOISTENS ESPLY
ALONG THE FOOTHILLS AFTER MIDNIGHT. MODELS INDICATE A GOOD DEAL OF
MID AND UPPER LEVEL QG ASCENT WITH THE SOUTHERN END OF THIS
TROUGH. HOWEVER MOST OF THIS ASCENT PASSES TO THE SOUTH OF THE
FORECAST AREA DURING THE DAY MONDAY. NEVERTHELESS...NORTH-
NORTHEASTERLY LOW LEVEL FLOW AND MODERATELY STRONG QG ASCENT
SHOULD BE SUFFICIENT TO PRODUCE SNOW SHOWERS IN THE N-CENTRAL MTNS
AND FRONT RANGE FOOTHILLS...AND SCATTERED RAIN SHOWERS AT LOWER
ELEVATIONS BY DAYLIGHT MONDAY. PRECIP UP AGAINST THE FOOTHILLS AND
OVER THE PALMER DIVIDE COULD CHANGE TO A MIX OF RAIN AND SNOW
BEFORE MORNING WITH THE MERCURY DIPPING TO THE LOWER 30S. HOWEVER
DO NOT EXPECT TO SEE ANY SNOW ACCUMULATION AS GROUND TEMPS WILL
REMAIN QUITE WARM. ANY SNOW AT LOWER ELEVATIONS SHOULD REVERT TO
ALL RAIN BY LATE MORNING WITH WARMING TEMPS...ONLY TO CHANGE BACK
TO A MIX OF RAIN AND SNOW TOWARDS EVENING. MODEL GUIDANCE
INDICATES UP TO AN INCH OR TWO OF WET SNOW OVER HIGHER AREAS JUST
SOUTH OF DENVER BY LATE THIS EVENING. AGAIN WITH THE GROUND AS
WARM AS IT IS...MUCH OF THIS SNOW SHOULD MELT SOON AFTER FALLING.
HIGHER AREAS IN THE FOOTHILLS...SAY ABOVE 7000 FEET...COULD SEE
SOME LIGHT SNOW ACCUMULATION ON THE ORDER OF 1 TO 4 INCHES BY
MONDAY EVENING...WITH SIMILAR TOTALS OVER THE HIGHER MTNS RIDGES
AND PASSES. THIS SYSTEM DOES NOT LOOK LIKE A BIG PRECIP PRODUCER
FOR US..BUT WE/LL TAKE WHAT WE CAN GET.
ON TUESDAY...MODELS SLOW TO MOVE OUT THIS TROUGH. SOME ACTUALLY
SHOW THIS SYSTEM WOBBLING BACK OVER EASTERN COLORADO DURING THE
DAY WHICH WOULD KEEP THE AREA UNDER CLOUDS AND COOL TEMPS AND
POSSIBLY KEEP A FEW SHOWERS AROUND. BY WEDNESDAY AND BEYOND
HIGH PRESSURE MOVES IN FROM THE WEST RESULTING IN A QUICK WARMUP
AND A RETURN TO DRY CONDITIONS AND PLENTY OF SUNSHINE AREAWIDE.
AVIATION...WINDS WILL REMAIN SOUTHERLY THROUGH TODAY AND TONIGHT.
MAY SEE SOME GUSTS TO 20 KNOTS THIS AFTERNOON AS STRONGER WINDS
ALOFT MIX DOWN. WILL SEE PERIODS OF HIGH CLOUDS THROUGH THE 24
HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING FROM NOON TO 8
PM MDT SATURDAY FOR COZ214-216-241.
FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR
COZ211-213-214-216-241-245>247-249.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1018 AM MDT SAT MAR 31 2012
.UPDATE...CURRENT FORECASTS LOOK ON TRACK. LATEST RUC AS WELL AS
HRRR RUNS CONTINUE TO SUPPORT RED FLAG CONDITIONS ACROSS THE
FOOTHILLS OF SOUTHERN JEFFERSON AND DOUGLAS COUNTIES AS WELL AS
THE PALMER DIVIDE AND SOUTH PARK FOR THIS AFTERNOON AND EVENING.
BELIEVE THERE WILL BE ENOUGH MIXING TO GET GUSTS TO 30 MPH IN
THAT AREA. LOWER NORTH FORK FIRE AREA SHOULD SEE SOUTHERLY WINDS
IN THE 10-20 MPH RANGE PRIMARILY...ALONG WITH A FEW GUSTS TO
30 MPH. STILL SOME QUESTION WHETHER GUSTY WINDS WILL SPREAD
FURTHER NORTH ACROSS THE PLAINS. DESPITE MIXING...FEEL WINDS
SHOULD STAY BELOW CRITERIA. AS FOR TEMPERATURES...RECORD FOR
DENVER SHOULD BE BROKEN DESPITE HIGH LEVEL CLOUDS. AS FOR FIRE
WEATHER WATCH SUNDAY...LATEST GUIDANCE STILL SUGGESTING MARGINAL
CONDITIONS. HOWEVER...DESPITE COOLING IT LOOKS LIKE INCREASING
GRADIENT WILL BE ENOUGH FOR AN UPGRADE TO A WARNING. WILL LOOK
FURTHER INTO THIS SCENARIO LATER. DON`T THINK THAT AREA WILL NEED
TO BE EXPANDED.
&&
.AVIATION...CURRENT TAFS LOOKING ON TRACK. GUIDANCE STILL SHOWING
WINDS BECOMING MORE SOUTHEAST ACROSS THE AREA AIRPORTS THIS
AFTERNOON. LATEST RUC INDICATING A BIT MORE WIND...WILL INCREASE
THE SPEEDS A BIT AT APA AND DEN.
&&
.PREV DISCUSSION... /ISSUED 436 AM MDT SAT MAR 31 2012/
..CORRECTION TO THIRD PARAGRAPH...
SHORT TERM...NORTHWEST FLOW ALOFT TO SHIFT TO THE SOUTHWEST
TONIGHT AS AN UPPER LEVEL RIDGE PASSES OVER COLORADO. THIS RIDGE
WILL BRING VERY WARM TEMPERATURES FOR THIS TIME OF YEAR. AIRMASS
WILL BE ABOUT 5 DEGREES FAHRENHEIT WARMER THAN YESTERDAY. THIS
WILL PUT MOST LOCATIONS OVER NORTHEAST COLORADO IN THE UPPER 70S
TO MID 80S. THE RECORD FOR TODAY AT THE DENVER AIRPORT IS 80
DEGREES AND HAS A GOOD CHANCE OF BEING SURPASSED. HIGH CLOUDS WILL
MOVE OVER THE STATE AT TIMES TODAY. DOES NOT APPEAR THERE WILL BE
ENOUGH CLOUD TO AFFECT TEMPERATURES MUCH TODAY.
FIRE WEATHER...THE VERY WARM AND DRY CONDITIONS WILL KEEP
FUELS VERY DRY. MOST LOCATIONS WILL SEE RELATIVE HUMIDITIES BELOW
15 PERCENT TODAY. WINDS WILL BECOME BREEZY THIS AFTERNOON ACROSS
PARTS OF THE AREA. SOUNDINGS ACROSS THE AREA SHOW PEAK WINDS OF
20-30 KNOTS IN THE MIX LAYER THIS AFTERNOON. SO MAY SEE SOME GUST
OF 25-35 MPH MIX DOWN OVER PARTS OF THE HIGH COUNTRY AND EASTERN
PLAINS. A RED FLAG WARNING IS IN EFFECT FOR PARK COUNTY...THE
SOUTHERN FOOTHILLS AND THE PALMER DIVIDE. THE STRONGER WINDS LOOK
TO BE OVER PARK COUNTY AND SOUTHERN PARTS OF JEFFERSON AND
DOUGLAS COUNTIES WHERE GUSTS TO 30 MPH WILL BE POSSIBLE FOR A FEW
HOURS THIS AFTERNOON. WINDS WILL BE NOTHING LIKE THEY WERE THIS
PAST MONDAY WHEN THE LOWER NORTH FORK FIRE ROARED ACROSS THE
FOOTHILLS. THE WINDS ACROSS THE LOWER NORTH FORK FIRE THIS
AFTERNOON ARE EXPECTED TO BE 10 TO 20 MPH WITH A FEW GUSTS UP TO
30 MPH POSSIBLE. WILL NOT EXPAND THE RED FLAG WARNING FOR TODAY
BECAUSE THE WINDS WILL HARD TIME STAYING ABOVE THE 25 MPH
THRESHOLD FOR 3 HOURS.
LONG TERM...ONE MORE DAY OF UNSEASONABLY WARM AND DRY CONDITIONS
ESPLY EAST OF THE MTNS ON SUNDAY. MODELS CONTINUE TO EVOLVE THE
UPPER TROUGH TO OUR WEST ON SUNDAY. PAST FEW DAYS...ALL SORTS OF
SOLUTIONS HAVE COME FORTH...ALTHOUGH THE PAST FEW ITERATIONS HAVE
CONVERGED ON THE IDEA OF A DEEP TROUGH WITH A CLOSED LOW NEAR THE
FOUR CORNERS SUNDAY NIGHT. ON SUNDAY SOUTHWESTERLY FLOW ALOFT
STRENGTHENS THROUGH THE DAY AS THE PRESSURE GRADIENT ON THE PLAINS
TIGHTENS WITH PRESSURE AND HEIGHT FALLS WEST OF THE MTNS. AT PRESENT
TIME...A FIRE WEATHER WATCH IS OUT FOR THE SOUTHEAST QUADRANT OF THE
FORECAST AREA...SPECIFICALLY FOR THE SOUTHERN FOOTHILLS WEST OF
DENVER...DOUGLAS AND ELBERT COUNTIES...EASTERN PORTIONS OF ADAMS AND
ARAPAHOE COUNTIES...AND WASHINGTON COUNTY...AS WELL AS NORTH...
MIDDLE AND SOUTH PARKS. LATEST MODEL GUIDANCE WOULD SUPPORT THIS
AREA BEING UNDER A WATCH...ALTHOUGH WIND SPEEDS SUNDAY AFTERNOON
ONLY MARGINALLY STRONG ENOUGH. FOR NOW MUST CONSIDER LATER GUIDANCE
BEFORE UPGRADING THE WATCH TO A WARNING. OTHERWISE HIGHS ON SUNDAY
SLIGHTLY COOLER...OR LESS WARM THAN ON SATURDAY WITH MID 70S TO
LOWER 80S ON THE PLAINS. SHOULD HIGH CLOUD SHIELD THICKEN UP SOONER
THAN EXPECTED...MAY NOT GET INTO THE 80S. RECORD HIGH AT DENVER ON
SUNDAY IS 78. SHOULD COME CLOSE IF NOT EXCEED IT.
OVERNIGHT SUNDAY...AS THE UPPER TROUGH SHIFTS OVER WESTERN
COLORADO...MODELS SHOW A STRONG COLD FRONT SURGING SOUTH ALONG THE
FRONT RANGE PUSHED ALONG BY 25 TO 40 MPH NORTHERLY WINDS. BOUNDARY
LAYER STARTS OUT VERY DRY THAT EVENING BUT QUICKLY MOISTENS ESPLY
ALONG THE FOOTHILLS AFTER MIDNIGHT. MODELS INDICATE A GOOD DEAL OF
MID AND UPPER LEVEL QG ASCENT WITH THE SOUTHERN END OF THIS
TROUGH. HOWEVER MOST OF THIS ASCENT PASSES TO THE SOUTH OF THE
FORECAST AREA DURING THE DAY MONDAY. NEVERTHELESS...NORTH-
NORTHEASTERLY LOW LEVEL FLOW AND MODERATELY STRONG QG ASCENT
SHOULD BE SUFFICIENT TO PRODUCE SNOW SHOWERS IN THE N-CENTRAL MTNS
AND FRONT RANGE FOOTHILLS...AND SCATTERED RAIN SHOWERS AT LOWER
ELEVATIONS BY DAYLIGHT MONDAY. PRECIP UP AGAINST THE FOOTHILLS AND
OVER THE PALMER DIVIDE COULD CHANGE TO A MIX OF RAIN AND SNOW
BEFORE MORNING WITH THE MERCURY DIPPING TO THE LOWER 30S. HOWEVER
DO NOT EXPECT TO SEE ANY SNOW ACCUMULATION AS GROUND TEMPS WILL
REMAIN QUITE WARM. ANY SNOW AT LOWER ELEVATIONS SHOULD REVERT TO
ALL RAIN BY LATE MORNING WITH WARMING TEMPS...ONLY TO CHANGE BACK
TO A MIX OF RAIN AND SNOW TOWARDS EVENING. MODEL GUIDANCE
INDICATES UP TO AN INCH OR TWO OF WET SNOW OVER HIGHER AREAS JUST
SOUTH OF DENVER BY LATE THIS EVENING. AGAIN WITH THE GROUND AS
WARM AS IT IS...MUCH OF THIS SNOW SHOULD MELT SOON AFTER FALLING.
HIGHER AREAS IN THE FOOTHILLS...SAY ABOVE 7000 FEET...COULD SEE
SOME LIGHT SNOW ACCUMULATION ON THE ORDER OF 1 TO 4 INCHES BY
MONDAY EVENING...WITH SIMILAR TOTALS OVER THE HIGHER MTNS RIDGES
AND PASSES. THIS SYSTEM DOES NOT LOOK LIKE A BIG PRECIP PRODUCER
FOR US..BUT WE/LL TAKE WHAT WE CAN GET.
ON TUESDAY...MODELS SLOW TO MOVE OUT THIS TROUGH. SOME ACTUALLY
SHOW THIS SYSTEM WOBBLING BACK OVER EASTERN COLORADO DURING THE
DAY WHICH WOULD KEEP THE AREA UNDER CLOUDS AND COOL TEMPS AND
POSSIBLY KEEP A FEW SHOWERS AROUND. BY WEDNESDAY AND BEYOND
HIGH PRESSURE MOVES IN FROM THE WEST RESULTING IN A QUICK WARMUP
AND A RETURN TO DRY CONDITIONS AND PLENTY OF SUNSHINE AREAWIDE.
AVIATION...WINDS WILL REMAIN SOUTHERLY THROUGH TODAY AND TONIGHT.
MAY SEE SOME GUSTS TO 20 KNOTS THIS AFTERNOON AS STRONGER WINDS
ALOFT MIX DOWN. WILL SEE PERIODS OF HIGH CLOUDS THROUGH THE 24
HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
247 PM CDT SAT MAR 31 2012
.DISCUSSION...
941 AM CDT
SOME CHANGES MADE TO THE GOING CLOUD AND TEMPERATURE TRENDS TO
SLOW THE CLEARING IN A FEW AREAS AND ACCORDINGLY STIFLE THE
TEMPERATURE RISE.
A BLANKET OF CLOUDS REMAIN OVER THE REGION THIS MORNING WITHIN
LOW-LEVEL RIDGING. RAOBS AND AMDAR MEASUREMENTS...AND SATELLITE
ESTIMATES...INDICATE THE CLOUD DEPTH BETWEEN 700 AND 1000 FT
THICK...WHICH IS CERTAINLY SHALLOW ENOUGH FOR THE FINAL DAY OF
MARCH THAT ONE WOULD THINK HOLES WILL BEGIN TO DEVELOP AND SPREAD
QUICKLY. EVEN SOME FURTHER SUBSIDENCE IS PREDICTED THE NEXT FEW
HOURS ABOVE THE CLOUD LAYER TO AID THAT. THE LATEST HRRR AND 31.12
NAM INDICATE SOME SCATTERING OVER LAKE MI INTO FAR NORTHEAST IL
AND NORTHWEST IN THROUGH THE NEXT FEW HOURS....WHICH MAKES DECENT
SENSE WITH DECREASING DEW POINTS WORKING IN FROM THAT DIRECTION.
ALSO A BREAK DOWN IN CLOUDS IS FAVORED IN RELATIVE HUMIDITY FIELDS
ACROSS THE SOUTH AND THE WEST.
THE ONE AREA THAT IS SHOWING SOMEWHAT OF A CONSISTENT SIGNAL TO BE
CLOUDED IN POTENTIALLY THROUGH MID TO LATE AFTERNOON IS THE
WINNEBAGO...BOONE... MCHENRY...DEKALB...AND KANE COUNTY AREAS.
OBVIOUSLY THAT IS A SPECIFIC AREA...BUT THE IDEA THAT TOWARD THE
WISCONSIN STATE LINE AWAY FROM THE DRY ADVECTION FROM THE EAST
WILL BE ONE OF THE FINAL AREAS TO CLEAR SEEMS REASONABLE. WITH
ONLY 2 TO 4 DEGREES OR SO MORE OF WARMING THROUGH NOON UNDER
OVERCAST SKY...WENT AHEAD AND CUT THEIR HIGH TEMPERATURE BY
SEVERAL DEGREES...AND TOOK 1 TO 2 DEGREES OFF ELSEWHERE. WITH THE
EASTERLY FLOW OFF THE LAKE...BORDERING LAKE COUNTIES OF NORTHEAST
IL ALSO SHOULD NOT CLIMB TOO RAPIDLY THIS AFTERNOON...WITH HIGHS
AT OR JUST A TAD ABOVE NORMAL. STILL LOWER TO MID 60S EXPECTED
ACROSS THE FAR SOUTH AND WEST.
MTF
//PREV DISCUSSION...
257 AM CDT
TODAY AND TONIGHT...RIDGE AXIS IN PLACE WITH EXPANSIVE AREA OF
STRATUS TRAPPED UNDER STRONG INVERSION EARLY THIS MORNING. EXPECT
CLOUD COVER TO ERODE BY LATE MORNING OR EARLY AFTERNOON UNDER
ANTICYCLONIC FLOW AND SUBSIDENCE. TEMPERATURES WILL THEN WARM INTO
THE LOW TO MID 60S AWAY FROM THE LAKE FRONT. NORTHEASTERLY FLOW OFF
THE LAKE WILL KEEP TEMPERATURES IN THE LOW TO MID 50S CLOSER TO THE
LAKEFRONT TODAY. THIS AFTERNOON...MOISTURE POOLING IS EXPECTED
ACROSS MISSOURI INTO CENTRAL IOWA WHERE DEW POINTS ARE EXPECTED TO
RISE INTO THE LOW 60S AS WARM FRONT LIFTS BACK NORTH. BY
TONIGHT...ISENTROPIC ASCENT WILL INCREASE WITH SHOWERS AND
THUNDERSTORMS DEVELOPING ALONG THE MOISTURE AXIS OVER PORTIONS OF
IOWA AND PUSHING EAST ON THE NOSE OF 40KT LOW LEVEL JET INTO
NORTHERN ILLINOIS LATE TONIGHT. SURFACE WINDS WILL VEER TO THE
SOUTHEAST WITH WARM ADVECTION OVERNIGHT HELPING TO PROP UP
TEMPERATURES...WHICH ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOW
50S BY LATE EVENING THE HOLD STEADY OR SLOWLY RISE OVERNIGHT.
SUNDAY...WARM FRONT DOES NOT ADVANCE MUCH DURING THE DAY SUNDAY WITH
A NORTHERN STREAM SYSTEM DROPPING SOUTHEAST ACROSS QUEBEC AND
TURNING FLOW BACK TO THE NORTHEAST FOR AT LEAST NORTHERN PORTIONS OF
THE FORECAST AREA. APPEARS THAT WITH THE FRONTAL BOUNDARY LINGERING
THROUGH THE DAY SUNDAY THAT WE WILL SET UP A STRONG TEMP GRADIENT
ACROSS THE CWA. ECMWF HAS COME MORE IN LINE WITH THIS SOLUTION WHICH
GFS HAS BEEN ADVERTISING THE PAST COUPLE DAYS. DROPPED TEMPERATURES
SEVERAL DEGREES ALONG THE LAKE SHORE AND WENT WITH NON-DIURNAL
TREND...SHOWING TEMPERATURES PEAKING EARLY IN THE DAY THEN DROPPING
AS LAKE AIR SPREADS INLAND WITH THE HELP OF SYNOPTICALLY NORTHEAST
FLOW. LINGERING SHOWERS AND CLOUD COVER IN THE MORNING ADD
ADDITIONAL UNCERTAINTY TO TEMPERATURE FORECAST...PARTICULARLY IN THE
WARMER AIR ACROSS EAST CENTRAL ILLINOIS.
MONDAY...GUIDANCE STILL A BIT MIXED ON HOW FAR NORTH THE WARM FRONT
WILL LIFT WITH GFS A SLOW/SOUTHERN OUTLIER AND PLACING PRECIP ALONG
THE WARM FRONT ACROSS NORTHERN ILLINOIS. OPTED TO KEEP FORECAST DRY
PER NAM/GEM/ECMWF SOLUTIONS WITH DRY AIR IN PLACE...DEEP MIXING
LAYERS AND VERY WARM TEMPERATURES. BUMPED UP TEMPS...ESPECIALLY
ACROSS THE SOUTH. BIAS CORRECTED NAM/ECMWF SHOW TEMPS SOARING INTO
THE 90S SOUTH OF THE I-80 CORRIDOR. SREF PLUMES SUPPORT MID 80S
ACROSS THE SOUTHERN PORTIONS OF THE CWA WITH STRONG CLUSTERING IN
THAT RANGE BUT A FEW SIGNIFICANT COLD OUTLIERS PULLING THE MEAN
INTO THE LOW 80S. MODEL CONSENSUS BLEND ALSO SUPPORTS MID 80S
ACROSS THE SOUTH. LAKE BREEZE IS POSSIBLE WITH MARGINAL WINDS
SPEEDS ALOFT SO MAY SEE TEMPERATURES COOL ALONG THE LAKE FRONT
THAT AFTERNOON.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
WHILE USHERING IN MORE SEASONABLE TEMPERATURES FOR THE REMAINDER OF
THE WEEK. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION
WEDNESDAY AND LINGERS THROUGH THE END OF THE WEEK. DRY CONDITIONS
SHOULD PERSIST WITH PLENTY OF SUNSHINE. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LIGHT EAST TO SOUTHEAST WINDS.
* CEILING AT MDW SCATTERING OUT BY LATE AFTERNOON.
* CHANCE FOR SHRA/TSRA TO MOVE ACROSS LATE TONIGHT/EARLY SUNDAY
MORNING.
PAW
//DISCUSSION...UPDATED 18Z...
SATELLITE SHOWS CEILINGS BREAKING UP TO THE SOUTHWEST OF THE
TERMINALS AND SOME THIN SPOTS DEVELOPING OVER NORTHEAST
ILLINOIS. THE TIMING OF CEILINGS SCATTERING OUT EARLY TO MID
AFTERNOON IS LOOKING GOOD.
THE NEXT SYSTEM WILL MOVE ACROSS NORTHERN ILLINOIS AND NORTHWEST
INDIANA SUNDAY MORNING. THERE IS POTENTIAL FOR A BAND OF SHRA/TSRA
TO MOVE ACROSS THE TERMINALS IN ADVANCE OF THE SYSTEM. HAVE NOT
CHANGED THE LATE TONIGHT/EARLY SUNDAY MORNING TIME FRAME AS BEING
THE MOST FAVORABLE FOR SHRA/TSRA...BUT MAY NEED TO ADJUST AS IT GETS
CLOSER.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND.
* MEDIUM CONFIDENCE IN CIG TREND AT MDW.
* MEDIUM CONFIDENCE IN SHRA/TSRA OCCURRING LATE TONIGHT/SUNDAY
MORNING. LOW CONFIDENCE IN TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
MDB
&&
.MARINE...
115 PM CDT
WINDS WILL TURN SOUTHERLY AND GRADUALLY INCREASE ACROSS LAKE MI
TONIGHT AS HIGH PRESSURE MOVES EAST FROM THE CENTRAL GREAT LAKES.
LOW PRESSURE WILL EVOLVE EASTWARD ACROSS THE LAKE ON SUNDAY MORNING.
AN ASSOCIATED COLD FRONT WILL SLIP SOUTH AS THIS OCCURS...TURNING
WINDS NORTHERLY ACROSS THE LAKE. THIS FRONT WILL LIKELY MOVE ACROSS
THE NEARSHORE AREAS OF IL AND IN DURING THE EARLY TO MID AFTERNOON
ON SUNDAY. HIGH PRESSURE WILL BRIEFLY PREVAIL ON SUNDAY NIGHT BEFORE
ANOTHER LOW MOVES EAST ACROSS IOWA INTO NORTHERN ILLINOIS. WINDS ARE
EXPECTED TO TURN BACK SOUTHEAST AHEAD OF THIS FEATURE ON MONDAY
AFTERNOON...WITH SOME GUSTS UP TO 25 KT...INCLUDING POSSIBLY IN THE
ILLINOIS NEAR SHORE AREAS. BEHIND THE LOW PASSAGE LATE MONDAY NIGHT
INTO EARLY TUESDAY...THE WINDS WILL ONCE AGAIN SWING BACK NORTHERLY.
HIGH PRESSURE IS THEN FORECAST TO ENCOMPASS MUCH OF THE LAKE
WEDNESDAY THROUGH FRIDAY...THOUGH CONFIDENCE IN THIS IS FAIRLY LOW
DUE TO A CLOSED UPPER LOW IN THE CENTRAL PLAINS WHICH COULD MEANDER
CLOSE ENOUGH TO CAUSE SLIGHTLY STRONGER WINDS. OVERALL AT THIS
TIME...NO LONG-LIVED GUSTY OR HIGH WAVE PERIODS ARE EXPECTED IN
THE NEXT WEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
115 PM CDT SAT MAR 31 2012
.DISCUSSION...
941 AM CDT
SOME CHANGES MADE TO THE GOING CLOUD AND TEMPERATURE TRENDS TO
SLOW THE CLEARING IN A FEW AREAS AND ACCORDINGLY STIFLE THE
TEMPERATURE RISE.
A BLANKET OF CLOUDS REMAIN OVER THE REGION THIS MORNING WITHIN
LOW-LEVEL RIDGING. RAOBS AND AMDAR MEASUREMENTS...AND SATELLITE
ESTIMATES...INDICATE THE CLOUD DEPTH BETWEEN 700 AND 1000 FT
THICK...WHICH IS CERTAINLY SHALLOW ENOUGH FOR THE FINAL DAY OF
MARCH THAT ONE WOULD THINK HOLES WILL BEGIN TO DEVELOP AND SPREAD
QUICKLY. EVEN SOME FURTHER SUBSIDENCE IS PREDICTED THE NEXT FEW
HOURS ABOVE THE CLOUD LAYER TO AID THAT. THE LATEST HRRR AND 31.12
NAM INDICATE SOME SCATTERING OVER LAKE MI INTO FAR NORTHEAST IL
AND NORTHWEST IN THROUGH THE NEXT FEW HOURS....WHICH MAKES DECENT
SENSE WITH DECREASING DEW POINTS WORKING IN FROM THAT DIRECTION.
ALSO A BREAK DOWN IN CLOUDS IS FAVORED IN RELATIVE HUMIDITY FIELDS
ACROSS THE SOUTH AND THE WEST.
THE ONE AREA THAT IS SHOWING SOMEWHAT OF A CONSISTENT SIGNAL TO BE
CLOUDED IN POTENTIALLY THROUGH MID TO LATE AFTERNOON IS THE
WINNEBAGO...BOONE... MCHENRY...DEKALB...AND KANE COUNTY AREAS.
OBVIOUSLY THAT IS A SPECIFIC AREA...BUT THE IDEA THAT TOWARD THE
WISCONSIN STATE LINE AWAY FROM THE DRY ADVECTION FROM THE EAST
WILL BE ONE OF THE FINAL AREAS TO CLEAR SEEMS REASONABLE. WITH
ONLY 2 TO 4 DEGREES OR SO MORE OF WARMING THROUGH NOON UNDER
OVERCAST SKY...WENT AHEAD AND CUT THEIR HIGH TEMPERATURE BY
SEVERAL DEGREES...AND TOOK 1 TO 2 DEGREES OFF ELSEWHERE. WITH THE
EASTERLY FLOW OFF THE LAKE...BORDERING LAKE COUNTIES OF NORTHEAST
IL ALSO SHOULD NOT CLIMB TOO RAPIDLY THIS AFTERNOON...WITH HIGHS
AT OR JUST A TAD ABOVE NORMAL. STILL LOWER TO MID 60S EXPECTED
ACROSS THE FAR SOUTH AND WEST.
MTF
//PREV DISCUSSION...
257 AM CDT
TODAY AND TONIGHT...RIDGE AXIS IN PLACE WITH EXPANSIVE AREA OF
STRATUS TRAPPED UNDER STRONG INVERSION EARLY THIS MORNING. EXPECT
CLOUD COVER TO ERODE BY LATE MORNING OR EARLY AFTERNOON UNDER
ANTICYCLONIC FLOW AND SUBSIDENCE. TEMPERATURES WILL THEN WARM INTO
THE LOW TO MID 60S AWAY FROM THE LAKE FRONT. NORTHEASTERLY FLOW OFF
THE LAKE WILL KEEP TEMPERATURES IN THE LOW TO MID 50S CLOSER TO THE
LAKEFRONT TODAY. THIS AFTERNOON...MOISTURE POOLING IS EXPECTED
ACROSS MISSOURI INTO CENTRAL IOWA WHERE DEW POINTS ARE EXPECTED TO
RISE INTO THE LOW 60S AS WARM FRONT LIFTS BACK NORTH. BY
TONIGHT...ISENTROPIC ASCENT WILL INCREASE WITH SHOWERS AND
THUNDERSTORMS DEVELOPING ALONG THE MOISTURE AXIS OVER PORTIONS OF
IOWA AND PUSHING EAST ON THE NOSE OF 40KT LOW LEVEL JET INTO
NORTHERN ILLINOIS LATE TONIGHT. SURFACE WINDS WILL VEER TO THE
SOUTHEAST WITH WARM ADVECTION OVERNIGHT HELPING TO PROP UP
TEMPERATURES...WHICH ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOW
50S BY LATE EVENING THE HOLD STEADY OR SLOWLY RISE OVERNIGHT.
SUNDAY...WARM FRONT DOES NOT ADVANCE MUCH DURING THE DAY SUNDAY WITH
A NORTHERN STREAM SYSTEM DROPPING SOUTHEAST ACROSS QUEBEC AND
TURNING FLOW BACK TO THE NORTHEAST FOR AT LEAST NORTHERN PORTIONS OF
THE FORECAST AREA. APPEARS THAT WITH THE FRONTAL BOUNDARY LINGERING
THROUGH THE DAY SUNDAY THAT WE WILL SET UP A STRONG TEMP GRADIENT
ACROSS THE CWA. ECMWF HAS COME MORE IN LINE WITH THIS SOLUTION WHICH
GFS HAS BEEN ADVERTISING THE PAST COUPLE DAYS. DROPPED TEMPERATURES
SEVERAL DEGREES ALONG THE LAKE SHORE AND WENT WITH NON-DIURNAL
TREND...SHOWING TEMPERATURES PEAKING EARLY IN THE DAY THEN DROPPING
AS LAKE AIR SPREADS INLAND WITH THE HELP OF SYNOPTICALLY NORTHEAST
FLOW. LINGERING SHOWERS AND CLOUD COVER IN THE MORNING ADD
ADDITIONAL UNCERTAINTY TO TEMPERATURE FORECAST...PARTICULARLY IN THE
WARMER AIR ACROSS EAST CENTRAL ILLINOIS.
MONDAY...GUIDANCE STILL A BIT MIXED ON HOW FAR NORTH THE WARM FRONT
WILL LIFT WITH GFS A SLOW/SOUTHERN OUTLIER AND PLACING PRECIP ALONG
THE WARM FRONT ACROSS NORTHERN ILLINOIS. OPTED TO KEEP FORECAST DRY
PER NAM/GEM/ECMWF SOLUTIONS WITH DRY AIR IN PLACE...DEEP MIXING
LAYERS AND VERY WARM TEMPERATURES. BUMPED UP TEMPS...ESPECIALLY
ACROSS THE SOUTH. BIAS CORRECTED NAM/ECMWF SHOW TEMPS SOARING INTO
THE 90S SOUTH OF THE I-80 CORRIDOR. SREF PLUMES SUPPORT MID 80S
ACROSS THE SOUTHERN PORTIONS OF THE CWA WITH STRONG CLUSTERING IN
THAT RANGE BUT A FEW SIGNIFICANT COLD OUTLIERS PULLING THE MEAN
INTO THE LOW 80S. MODEL CONSENSUS BLEND ALSO SUPPORTS MID 80S
ACROSS THE SOUTH. LAKE BREEZE IS POSSIBLE WITH MARGINAL WINDS
SPEEDS ALOFT SO MAY SEE TEMPERATURES COOL ALONG THE LAKE FRONT
THAT AFTERNOON.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
WHILE USHERING IN MORE SEASONABLE TEMPERATURES FOR THE REMAINDER OF
THE WEEK. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION
WEDNESDAY AND LINGERS THROUGH THE END OF THE WEEK. DRY CONDITIONS
SHOULD PERSIST WITH PLENTY OF SUNSHINE. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS SCATTERING OUT THIS AFTERNOON.
* LIGHT WINDS GRADUALLY SHIFTING TO MORE OF AN EAST-SOUTHEAST
DIRECTION THROUGH THE AFTERNOON.
* CHANCE FOR SHRA/TSRA TO MOVE ACROSS LATE TONIGHT/EARLY SUNDAY
MORNING.
PAW
//DISCUSSION...UPDATED 18Z...
SATELLITE SHOWS CEILINGS BREAKING UP TO THE SOUTHWEST OF THE
TERMINALS AND SOME THIN SPOTS DEVELOPING OVER NORTHEAST
ILLINOIS. THE TIMING OF CEILINGS SCATTERING OUT EARLY TO MID
AFTERNOON IS LOOKING GOOD.
THE NEXT SYSTEM WILL MOVE ACROSS NORTHERN ILLINOIS AND NORTHWEST
INDIANA SUNDAY MORNING. THERE IS POTENTIAL FOR A BAND OF SHRA/TSRA
TO MOVE ACROSS THE TERMINALS IN ADVANCE OF THE SYSTEM. HAVE NOT
CHANGED THE LATE TONIGHT/EARLY SUNDAY MORNING TIME FRAME AS BEING
THE MOST FAVORABLE FOR SHRA/TSRA...BUT MAY NEED TO ADJUST AS IT GETS
CLOSER.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN CEILING TREND AND TIMING.
* HIGH CONFIDENCE IN WIND TREND.
* MEDIUM CONFIDENCE IN SHRA/TSRA OCCURRING LATE TONIGHT/SUNDAY
MORNING. LOW CONFIDENCE IN TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
MDB
&&
.MARINE...
115 PM CDT
WINDS WILL TURN SOUTHERLY AND GRADUALLY INCREASE ACROSS LAKE MI
TONIGHT AS HIGH PRESSURE MOVES EAST FROM THE CENTRAL GREAT LAKES.
LOW PRESSURE WILL EVOLVE EASTWARD ACROSS THE LAKE ON SUNDAY MORNING.
AN ASSOCIATED COLD FRONT WILL SLIP SOUTH AS THIS OCCURS...TURNING
WINDS NORTHERLY ACROSS THE LAKE. THIS FRONT WILL LIKELY MOVE ACROSS
THE NEARSHORE AREAS OF IL AND IN DURING THE EARLY TO MID AFTERNOON
ON SUNDAY. HIGH PRESSURE WILL BRIEFLY PREVAIL ON SUNDAY NIGHT BEFORE
ANOTHER LOW MOVES EAST ACROSS IOWA INTO NORTHERN ILLINOIS. WINDS ARE
EXPECTED TO TURN BACK SOUTHEAST AHEAD OF THIS FEATURE ON MONDAY
AFTERNOON...WITH SOME GUSTS UP TO 25 KT...INCLUDING POSSIBLY IN THE
ILLINOIS NEAR SHORE AREAS. BEHIND THE LOW PASSAGE LATE MONDAY NIGHT
INTO EARLY TUESDAY...THE WINDS WILL ONCE AGAIN SWING BACK NORTHERLY.
HIGH PRESSURE IS THEN FORECAST TO ENCOMPASS MUCH OF THE LAKE
WEDNESDAY THROUGH FRIDAY...THOUGH CONFIDENCE IN THIS IS FAIRLY LOW
DUE TO A CLOSED UPPER LOW IN THE CENTRAL PLAINS WHICH COULD MEANDER
CLOSE ENOUGH TO CAUSE SLIGHTLY STRONGER WINDS. OVERALL AT THIS
TIME...NO LONG-LIVED GUSTY OR HIGH WAVE PERIODS ARE EXPECTED IN
THE NEXT WEEK.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1255 PM CDT SAT MAR 31 2012
.DISCUSSION...
ISSUED 1040 AM CDT SAT MAR 31 2012
LOW STRATUS DECK COVERED MUCH OF CENTRAL AND SOUTHEAST THIS
MORNING. THIS MOISTURE WAS TRAPPED BENEATH A PRETTY STOUT
SUBSIDENCE INVERSION PER 12Z KILX/KDVN SOUNDINGS. THE INVERSION IS
STRONGER THAN FORECAST BY THE MODELS...AND HAS RESULTED IN A
SLOWER CLEARING TRENDS THAN PREVIOUSLY ANTICIPATED. HOWEVER...
RECENT VISIBLE SATELLITE LOOPS SHOW THE STRATUS STARTING TO ERODE
FROM THE SOUTHWEST. THIS CLEARING TREND IS EXPECTED TO CONTINUE AS
DIURNAL HEATING INCREASES...AND THE CLEARING TREND WILL ALSO BE
AIDED BY SURFACE WINDS TRENDING TO THE SOUTHEAST IN THE WAKE OF
THE SURFACE RIDGE AXIS CURRENTLY OVER THE AREA.
HAVE UPDATED GRIDS FOR SLOWER CLEARING TRENDS...AS WELL AS A
RELATED SLOWER TEMPERATURE WARM UP. ALSO KNOCKED A DEGREE OR TWO
OFF MAX TEMPERATURES ALONG/NORTH OF THE I-74 CORRIDOR WHERE SKIES
WILL CLEAR THE LATEST AND PRESENT TEMPS ARE 20 DEGREES BELOW
FORECAST HIGHS.
BAK
&&
.AVIATION...
ISSUED 1255 PM CDT SAT MAR 31 2012
LOW CLOUDS HAVE FINALLY ERODED ACROSS THE CENTRAL ILLINOIS
TERMINALS...LEAVING MAINLY SCATTERED MID/HIGH CLOUDS IN THEIR
WAKE. VFR CONDITIONS SHOULD PREVAIL FOR THE MAJORITY OF THE 18Z TAF
VALID TIME. THE MAIN FLY IN THE OINTMENT IS THE EXPECTED MCS
DEVELOPMENT UPSTREAM ACROSS IOWA TONIGHT. THE MAJORITY OF THE
FORECAST MODELS HAVE THIS STORM COMPLEX IMPACTING AT LEAST SOME OF
THE TERMINALS OVERNIGHT/EARLY SUNDAY. STILL A FAIR AMOUNT OF
UNCERTAINTY WITH RESPECT TO TIMING AND AREAL COVERAGE...SO HAVE
ONLY CARRIED A VCTS MENTION IN THE TERMINALS AND LEFT CIGS/VSBYS
VFR. THIS COULD REQUIRE SIGNIFICANT CHANGES ONCE THE STORMS
INITIATE AND WE HAVE A BETTER IDEA OF WHERE/WHEN THEY WILL IMPACT
CENTRAL ILLINOIS.
WINDS...GENERALLY AOB 10 KTS...WILL CONTINUE TO TREND MORE
SOUTHERLY WITH TIME THIS AFTERNOON/TONIGHT AS A SURFACE RIDGE AXIS
CLEARS THE AREA. THEY SHOULD TREND MORE SOUTHWESTERLY AFTER
DAYBREAK SUNDAY IN THE WAKE OF THE MCS. CONSIDERABLE LOCAL
VARIABILITY IS POSSIBLE IF STORMS IMPACT A TERMINAL LATER TONIGHT.
BAK
&&
.PREV DISCUSSION...
ISSUED 255 AM CDT SAT MAR 31 2012
THE COLD FRONT THAT PASSED THROUGH LAST EVENING WAS NEAR THE OHIO
RIVER EARLY THIS MORNING. NORTHEAST WINDS ARE BRINGING A STRATUS
DECK SOUTHEASTWARD...REACHING TAYLORVILLE AND MATTOON AT 3 AM.
SIGNIFICANT PUSH OF COOLER AIR HAS DROPPED TEMPERATURES INTO THE
40S UNDERNEATH THE CLOUDS.
INITIAL FORECAST CONCERNS INVOLVE TEMPERATURES TODAY WITH THE
EFFECTS OF ANY LINGERING CLOUD COVER...AS WELL AS MUCH WARMER
CONDITIONS FOR SUNDAY AND MONDAY. TIMING AND COVERAGE OF MIDWEEK
SHOWERS ARE ALSO AN ISSUE.
SHORT TERM...TODAY THROUGH MONDAY...
LATEST RUC AND HRRR MODELS SUGGESTING THAT THE CLOUD DECK SHOULD
TRACK A LITTLE FURTHER SOUTH IN THE NEXT FEW HOURS...BEFORE
BEGINNING TO ERODE. WITH THIS THINKING...HAVE TRENDED THE SKY
GRIDS TO BE MOSTLY SUNNY BY MIDDAY...EXCEPT PERHAPS OVER THE FAR
NORTH. SHOULD GET TEMPERATURES INTO THE 70S ACROSS THE
SOUTHWEST...WITH COOLER 60S NORTHEAST. A SLOWER THAN EXPECTED
CLOUD BREAKUP WOULD RESULT IN TEMPERATURES IN THAT AREA CLOSER TO
THE COOLER MET GUIDANCE...BUT HAVE GONE CLOSER TO THE WARMER MAV
MOS AT THE MOMENT.
LATEST MODEL SUITE SHOWING MCS DEVELOPMENT ACROSS EASTERN IOWA
OVERNIGHT...AS A FRONTAL BOUNDARY ESTABLISHES ITSELF FROM NORTHERN
IOWA TO LOWER MICHIGAN. LATEST ECMWF MODEL IS THE FURTHEST SOUTH
WITH THE TRACK...REACHING POTENTIALLY AS FAR SOUTH AS SPRINGFIELD
AND DECATUR BY SUNRISE. THE REMAINING MODELS HAVE THE MCS SKIMMING
THE NORTH/NORTHEAST BORDER. HAVE MAINTAINED THE RAIN CHANCES OVER
THE NORTHERN HALF OF THE CWA...PRIMARILY BETWEEN MIDNIGHT AND
SUNRISE...AND SCALED THEM BACK ACROSS THE SOUTH.
UPPER RIDGE PROGGED BY THE MODELS TO AMPLIFY OVER THE CENTRAL
UNITED STATES THIS WEEKEND...SHIFTING TO THE MISSISSIPPI VALLEY BY
EARLY MONDAY MORNING. PRETTY GOOD SLUG OF WARM AIR WILL SPREAD
OVER THE STATE...WITH 850 MB TEMPERATURES RISING TO NEAR 20C ON
MONDAY. HAVE CONTINUED WITH THE 80S FOR HIGHS FOR SUNDAY...BUT
WILL NEED TO MONITOR THE CIRRUS BLOWOFF FROM THE MCS WHICH MAY
HELP KEEP TEMPS FROM RISING QUITE AS MUCH. HOWEVER...HAVE BOOSTED
HIGHS ON MONDAY BY A FEW DEGREES FROM EARLIER FORECASTS...AS THAT
WARMER AIR AT 850 MB MIXES TOWARD THE SURFACE. MAY SEE SOME RECORD
HIGHS AGAIN...AS CURRENT VALUES ARE IN THE MID TO UPPER 80S.
MAV/MEX MOS GUIDANCE SUGGESTING SOME 90 DEGREE READINGS ARE
POSSIBLE ACROSS THE SOUTHWEST CWA.
LONG TERM...TUESDAY THROUGH FRIDAY...
UPPER LEVEL TROUGHING ACROSS THE DESERT SOUTHWEST LATE THIS
WEEKEND WILL CUT OFF INTO A CLOSED LOW...WHICH IS PROGGED TO DRIFT
INTO THE CENTRAL PLAINS BY MIDWEEK. EXTENDED RANGE MODELS STARTING
TO TREND NORTHWARD WITH THIS TRACK...WITH THE GFS THE FARTHEST
NORTH INTO SOUTHERN IOWA. CURRENTLY PREFER THE MORE SOUTHERN
SOLUTION SOUTH OF THE OHIO VALLEY. AN EXTENDED PERIOD OF RAIN IS
LIKELY OVER PORTIONS OF THE MID-MISSISSIPPI VALLEY...BUT DRY
EASTERLY WINDS ASSOCIATED WITH A HIGH OVER THE GREAT LAKES WILL
CAUSE SOME EROSION OF THE PRECIP ON THE NORTHEAST FLANK. THE
LATEST ECMWF SURGES THE PRECIPITATION MUCH FURTHER NORTH THAN ITS
EARLIER RUN AND COVERS MOST OF THE CWA...WHILE THE CANADIAN MODEL
IS MORE LIMITED TO THE SOUTHEAST. HAVE INTRODUCED SLIGHT CHANCE
POPS FOR NOW ACROSS THE SOUTHEAST CWA WEDNESDAY NIGHT AND
THURSDAY...AND THESE MAY NEED TO BE BOOSTED IN FUTURE PACKAGES AS
MODEL AGREEMENT BECOMES TIGHTER.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1240 PM CDT SAT MAR 31 2012
.DISCUSSION...
941 AM CDT
SOME CHANGES MADE TO THE GOING CLOUD AND TEMPERATURE TRENDS TO
SLOW THE CLEARING IN A FEW AREAS AND ACCORDINGLY STIFLE THE
TEMPERATURE RISE.
A BLANKET OF CLOUDS REMAIN OVER THE REGION THIS MORNING WITHIN
LOW-LEVEL RIDGING. RAOBS AND AMDAR MEASUREMENTS...AND SATELLITE
ESTIMATES...INDICATE THE CLOUD DEPTH BETWEEN 700 AND 1000 FT
THICK...WHICH IS CERTAINLY SHALLOW ENOUGH FOR THE FINAL DAY OF
MARCH THAT ONE WOULD THINK HOLES WILL BEGIN TO DEVELOP AND SPREAD
QUICKLY. EVEN SOME FURTHER SUBSIDENCE IS PREDICTED THE NEXT FEW
HOURS ABOVE THE CLOUD LAYER TO AID THAT. THE LATEST HRRR AND 31.12
NAM INDICATE SOME SCATTERING OVER LAKE MI INTO FAR NORTHEAST IL
AND NORTHWEST IN THROUGH THE NEXT FEW HOURS....WHICH MAKES DECENT
SENSE WITH DECREASING DEW POINTS WORKING IN FROM THAT DIRECTION.
ALSO A BREAK DOWN IN CLOUDS IS FAVORED IN RELATIVE HUMIDITY FIELDS
ACROSS THE SOUTH AND THE WEST.
THE ONE AREA THAT IS SHOWING SOMEWHAT OF A CONSISTENT SIGNAL TO BE
CLOUDED IN POTENTIALLY THROUGH MID TO LATE AFTERNOON IS THE
WINNEBAGO...BOONE... MCHENRY...DEKALB...AND KANE COUNTY AREAS.
OBVIOUSLY THAT IS A SPECIFIC AREA...BUT THE IDEA THAT TOWARD THE
WISCONSIN STATE LINE AWAY FROM THE DRY ADVECTION FROM THE EAST
WILL BE ONE OF THE FINAL AREAS TO CLEAR SEEMS REASONABLE. WITH
ONLY 2 TO 4 DEGREES OR SO MORE OF WARMING THROUGH NOON UNDER
OVERCAST SKY...WENT AHEAD AND CUT THEIR HIGH TEMPERATURE BY
SEVERAL DEGREES...AND TOOK 1 TO 2 DEGREES OFF ELSEWHERE. WITH THE
EASTERLY FLOW OFF THE LAKE...BORDERING LAKE COUNTIES OF NORTHEAST
IL ALSO SHOULD NOT CLIMB TOO RAPIDLY THIS AFTERNOON...WITH HIGHS
AT OR JUST A TAD ABOVE NORMAL. STILL LOWER TO MID 60S EXPECTED
ACROSS THE FAR SOUTH AND WEST.
MTF
//PREV DISCUSSION...
257 AM CDT
TODAY AND TONIGHT...RIDGE AXIS IN PLACE WITH EXPANSIVE AREA OF
STRATUS TRAPPED UNDER STRONG INVERSION EARLY THIS MORNING. EXPECT
CLOUD COVER TO ERODE BY LATE MORNING OR EARLY AFTERNOON UNDER
ANTICYCLONIC FLOW AND SUBSIDENCE. TEMPERATURES WILL THEN WARM INTO
THE LOW TO MID 60S AWAY FROM THE LAKE FRONT. NORTHEASTERLY FLOW OFF
THE LAKE WILL KEEP TEMPERATURES IN THE LOW TO MID 50S CLOSER TO THE
LAKEFRONT TODAY. THIS AFTERNOON...MOISTURE POOLING IS EXPECTED
ACROSS MISSOURI INTO CENTRAL IOWA WHERE DEW POINTS ARE EXPECTED TO
RISE INTO THE LOW 60S AS WARM FRONT LIFTS BACK NORTH. BY
TONIGHT...ISENTROPIC ASCENT WILL INCREASE WITH SHOWERS AND
THUNDERSTORMS DEVELOPING ALONG THE MOISTURE AXIS OVER PORTIONS OF
IOWA AND PUSHING EAST ON THE NOSE OF 40KT LOW LEVEL JET INTO
NORTHERN ILLINOIS LATE TONIGHT. SURFACE WINDS WILL VEER TO THE
SOUTHEAST WITH WARM ADVECTION OVERNIGHT HELPING TO PROP UP
TEMPERATURES...WHICH ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOW
50S BY LATE EVENING THE HOLD STEADY OR SLOWLY RISE OVERNIGHT.
SUNDAY...WARM FRONT DOES NOT ADVANCE MUCH DURING THE DAY SUNDAY WITH
A NORTHERN STREAM SYSTEM DROPPING SOUTHEAST ACROSS QUEBEC AND
TURNING FLOW BACK TO THE NORTHEAST FOR AT LEAST NORTHERN PORTIONS OF
THE FORECAST AREA. APPEARS THAT WITH THE FRONTAL BOUNDARY LINGERING
THROUGH THE DAY SUNDAY THAT WE WILL SET UP A STRONG TEMP GRADIENT
ACROSS THE CWA. ECMWF HAS COME MORE IN LINE WITH THIS SOLUTION WHICH
GFS HAS BEEN ADVERTISING THE PAST COUPLE DAYS. DROPPED TEMPERATURES
SEVERAL DEGREES ALONG THE LAKE SHORE AND WENT WITH NON-DIURNAL
TREND...SHOWING TEMPERATURES PEAKING EARLY IN THE DAY THEN DROPPING
AS LAKE AIR SPREADS INLAND WITH THE HELP OF SYNOPTICALLY NORTHEAST
FLOW. LINGERING SHOWERS AND CLOUD COVER IN THE MORNING ADD
ADDITIONAL UNCERTAINTY TO TEMPERATURE FORECAST...PARTICULARLY IN THE
WARMER AIR ACROSS EAST CENTRAL ILLINOIS.
MONDAY...GUIDANCE STILL A BIT MIXED ON HOW FAR NORTH THE WARM FRONT
WILL LIFT WITH GFS A SLOW/SOUTHERN OUTLIER AND PLACING PRECIP ALONG
THE WARM FRONT ACROSS NORTHERN ILLINOIS. OPTED TO KEEP FORECAST DRY
PER NAM/GEM/ECMWF SOLUTIONS WITH DRY AIR IN PLACE...DEEP MIXING
LAYERS AND VERY WARM TEMPERATURES. BUMPED UP TEMPS...ESPECIALLY
ACROSS THE SOUTH. BIAS CORRECTED NAM/ECMWF SHOW TEMPS SOARING INTO
THE 90S SOUTH OF THE I-80 CORRIDOR. SREF PLUMES SUPPORT MID 80S
ACROSS THE SOUTHERN PORTIONS OF THE CWA WITH STRONG CLUSTERING IN
THAT RANGE BUT A FEW SIGNIFICANT COLD OUTLIERS PULLING THE MEAN
INTO THE LOW 80S. MODEL CONSENSUS BLEND ALSO SUPPORTS MID 80S
ACROSS THE SOUTH. LAKE BREEZE IS POSSIBLE WITH MARGINAL WINDS
SPEEDS ALOFT SO MAY SEE TEMPERATURES COOL ALONG THE LAKE FRONT
THAT AFTERNOON.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
WHILE USHERING IN MORE SEASONABLE TEMPERATURES FOR THE REMAINDER OF
THE WEEK. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION
WEDNESDAY AND LINGERS THROUGH THE END OF THE WEEK. DRY CONDITIONS
SHOULD PERSIST WITH PLENTY OF SUNSHINE. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS SCATTERING OUT THIS AFTERNOON.
* LIGHT WINDS GRADUALLY SHIFTING TO MORE OF AN EAST-SOUTHEAST
DIRECTION THROUGH THE AFTERNOON.
* CHANCE FOR SHRA/TSRA TO MOVE ACROSS LATE TONIGHT/EARLY SUNDAY
MORNING.
PAW
//DISCUSSION...UPDATED 18Z...
SATELLITE SHOWS CEILINGS BREAKING UP TO THE SOUTHWEST OF THE
TERMINALS AND SOME THIN SPOTS DEVELOPING OVER NORTHEAST
ILLINOIS. THE TIMING OF CEILINGS SCATTERING OUT EARLY TO MID
AFTERNOON IS LOOKING GOOD.
THE NEXT SYSTEM WILL MOVE ACROSS NORTHERN ILLINOIS AND NORTHWEST
INDIANA SUNDAY MORNING. THERE IS POTENTIAL FOR A BAND OF SHRA/TSRA
TO MOVE ACROSS THE TERMINALS IN ADVANCE OF THE SYSTEM. HAVE NOT
CHANGED THE LATE TONIGHT/EARLY SUNDAY MORNING TIME FRAME AS BEING
THE MOST FAVORABLE FOR SHRA/TSRA...BUT MAY NEED TO ADJUST AS IT GETS
CLOSER.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN CEILING TREND AND TIMING.
* HIGH CONFIDENCE IN WIND TREND.
* MEDIUM CONFIDENCE IN SHRA/TSRA OCCURRING LATE TONIGHT/SUNDAY
MORNING. LOW CONFIDENCE IN TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
MDB
&&
.MARINE...
257 AM CDT
HIGH PRESSURE SPREAD FROM HUDSON BAY SOUTH AND SOUTHWEST ACROSS LAKE
MICHIGAN CONTINUES TO PROVIDE NORTHEAST TO SOUTHEAST WINDS ACROSS
THE LAKE EARLY THIS MORNING. WINDS WILL TURN SOUTHERLY THIS
AFTERNOON AS THE RIDGE AXIS SHIFTS EASTWARD AND OUT OF THE AREA. LOW
PRESSURE ACROSS THE CANADIAN PRAIRIES WILL WEAKEN AS IT MOVES EAST
BUT THE PRESSURE GRADIENT BETWEEN THE RIDGE AND THE TROUGH WILL
BRING AN INCREASE IN SOUTHERLY WINDS TO NORTHERN SECTIONS OF THE
LAKE THIS EVENING. THE WEAKENED LOW WILL PASS TO THE NORTHEAST OF
LAKE MICHIGAN SUNDAY MORNING SHIFTING WINDS TO THE NORTHEAST ONCE
AGAIN DURING THE DAY SUNDAY. A RIDGE AXIS WILL THEN ARRIVE FROM THE
NORTH SUNDAY EVENING BRINGING WINDS MORE TO THE SOUTHEAST BUT
ANOTHER LOW WILL PASS TO THE SOUTH OF THE LAKE TUESDAY MORNING
BRINGING A RETURN OF NORTHERLY WINDS. HIGH PRESSURE IS EXPECTED TO
RETURN LATER TUESDAY AND REMAIN IN PLACE THROUGH THE END OF THE
WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1104 AM CDT SAT MAR 31 2012
.DISCUSSION...
941 AM CDT
SOME CHANGES MADE TO THE GOING CLOUD AND TEMPERATURE TRENDS TO
SLOW THE CLEARING IN A FEW AREAS AND ACCORDINGLY STIFLE THE
TEMPERATURE RISE.
A BLANKET OF CLOUDS REMAIN OVER THE REGION THIS MORNING WITHIN
LOW-LEVEL RIDGING. RAOBS AND AMDAR MEASUREMENTS...AND SATELLITE
ESTIMATES...INDICATE THE CLOUD DEPTH BETWEEN 700 AND 1000 FT
THICK...WHICH IS CERTAINLY SHALLOW ENOUGH FOR THE FINAL DAY OF
MARCH THAT ONE WOULD THINK HOLES WILL BEGIN TO DEVELOP AND SPREAD
QUICKLY. EVEN SOME FURTHER SUBSIDENCE IS PREDICTED THE NEXT FEW
HOURS ABOVE THE CLOUD LAYER TO AID THAT. THE LATEST HRRR AND 31.12
NAM INDICATE SOME SCATTERING OVER LAKE MI INTO FAR NORTHEAST IL
AND NORTHWEST IN THROUGH THE NEXT FEW HOURS....WHICH MAKES DECENT
SENSE WITH DECREASING DEW POINTS WORKING IN FROM THAT DIRECTION.
ALSO A BREAK DOWN IN CLOUDS IS FAVORED IN RELATIVE HUMIDITY FIELDS
ACROSS THE SOUTH AND THE WEST.
THE ONE AREA THAT IS SHOWING SOMEWHAT OF A CONSISTENT SIGNAL TO BE
CLOUDED IN POTENTIALLY THROUGH MID TO LATE AFTERNOON IS THE
WINNEBAGO...BOONE... MCHENRY...DEKALB...AND KANE COUNTY AREAS.
OBVIOUSLY THAT IS A SPECIFIC AREA...BUT THE IDEA THAT TOWARD THE
WISCONSIN STATE LINE AWAY FROM THE DRY ADVECTION FROM THE EAST
WILL BE ONE OF THE FINAL AREAS TO CLEAR SEEMS REASONABLE. WITH
ONLY 2 TO 4 DEGREES OR SO MORE OF WARMING THROUGH NOON UNDER
OVERCAST SKY...WENT AHEAD AND CUT THEIR HIGH TEMPERATURE BY
SEVERAL DEGREES...AND TOOK 1 TO 2 DEGREES OFF ELSEWHERE. WITH THE
EASTERLY FLOW OFF THE LAKE...BORDERING LAKE COUNTIES OF NORTHEAST
IL ALSO SHOULD NOT CLIMB TOO RAPIDLY THIS AFTERNOON...WITH HIGHS
AT OR JUST A TAD ABOVE NORMAL. STILL LOWER TO MID 60S EXPECTED
ACROSS THE FAR SOUTH AND WEST.
MTF
//PREV DISCUSSION...
257 AM CDT
TODAY AND TONIGHT...RIDGE AXIS IN PLACE WITH EXPANSIVE AREA OF
STRATUS TRAPPED UNDER STRONG INVERSION EARLY THIS MORNING. EXPECT
CLOUD COVER TO ERODE BY LATE MORNING OR EARLY AFTERNOON UNDER
ANTICYCLONIC FLOW AND SUBSIDENCE. TEMPERATURES WILL THEN WARM INTO
THE LOW TO MID 60S AWAY FROM THE LAKE FRONT. NORTHEASTERLY FLOW OFF
THE LAKE WILL KEEP TEMPERATURES IN THE LOW TO MID 50S CLOSER TO THE
LAKEFRONT TODAY. THIS AFTERNOON...MOISTURE POOLING IS EXPECTED
ACROSS MISSOURI INTO CENTRAL IOWA WHERE DEW POINTS ARE EXPECTED TO
RISE INTO THE LOW 60S AS WARM FRONT LIFTS BACK NORTH. BY
TONIGHT...ISENTROPIC ASCENT WILL INCREASE WITH SHOWERS AND
THUNDERSTORMS DEVELOPING ALONG THE MOISTURE AXIS OVER PORTIONS OF
IOWA AND PUSHING EAST ON THE NOSE OF 40KT LOW LEVEL JET INTO
NORTHERN ILLINOIS LATE TONIGHT. SURFACE WINDS WILL VEER TO THE
SOUTHEAST WITH WARM ADVECTION OVERNIGHT HELPING TO PROP UP
TEMPERATURES...WHICH ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOW
50S BY LATE EVENING THE HOLD STEADY OR SLOWLY RISE OVERNIGHT.
SUNDAY...WARM FRONT DOES NOT ADVANCE MUCH DURING THE DAY SUNDAY WITH
A NORTHERN STREAM SYSTEM DROPPING SOUTHEAST ACROSS QUEBEC AND
TURNING FLOW BACK TO THE NORTHEAST FOR AT LEAST NORTHERN PORTIONS OF
THE FORECAST AREA. APPEARS THAT WITH THE FRONTAL BOUNDARY LINGERING
THROUGH THE DAY SUNDAY THAT WE WILL SET UP A STRONG TEMP GRADIENT
ACROSS THE CWA. ECMWF HAS COME MORE IN LINE WITH THIS SOLUTION WHICH
GFS HAS BEEN ADVERTISING THE PAST COUPLE DAYS. DROPPED TEMPERATURES
SEVERAL DEGREES ALONG THE LAKE SHORE AND WENT WITH NON-DIURNAL
TREND...SHOWING TEMPERATURES PEAKING EARLY IN THE DAY THEN DROPPING
AS LAKE AIR SPREADS INLAND WITH THE HELP OF SYNOPTICALLY NORTHEAST
FLOW. LINGERING SHOWERS AND CLOUD COVER IN THE MORNING ADD
ADDITIONAL UNCERTAINTY TO TEMPERATURE FORECAST...PARTICULARLY IN THE
WARMER AIR ACROSS EAST CENTRAL ILLINOIS.
MONDAY...GUIDANCE STILL A BIT MIXED ON HOW FAR NORTH THE WARM FRONT
WILL LIFT WITH GFS A SLOW/SOUTHERN OUTLIER AND PLACING PRECIP ALONG
THE WARM FRONT ACROSS NORTHERN ILLINOIS. OPTED TO KEEP FORECAST DRY
PER NAM/GEM/ECMWF SOLUTIONS WITH DRY AIR IN PLACE...DEEP MIXING
LAYERS AND VERY WARM TEMPERATURES. BUMPED UP TEMPS...ESPECIALLY
ACROSS THE SOUTH. BIAS CORRECTED NAM/ECMWF SHOW TEMPS SOARING INTO
THE 90S SOUTH OF THE I-80 CORRIDOR. SREF PLUMES SUPPORT MID 80S
ACROSS THE SOUTHERN PORTIONS OF THE CWA WITH STRONG CLUSTERING IN
THAT RANGE BUT A FEW SIGNIFICANT COLD OUTLIERS PULLING THE MEAN
INTO THE LOW 80S. MODEL CONSENSUS BLEND ALSO SUPPORTS MID 80S
ACROSS THE SOUTH. LAKE BREEZE IS POSSIBLE WITH MARGINAL WINDS
SPEEDS ALOFT SO MAY SEE TEMPERATURES COOL ALONG THE LAKE FRONT
THAT AFTERNOON.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
WHILE USHERING IN MORE SEASONABLE TEMPERATURES FOR THE REMAINDER OF
THE WEEK. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION
WEDNESDAY AND LINGERS THROUGH THE END OF THE WEEK. DRY CONDITIONS
SHOULD PERSIST WITH PLENTY OF SUNSHINE. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIGS SCATTERING OUT EARLY AFTERNOON.
* EAST TO NORTHEAST WIND DIRECTION WILL GRADUALLY SHIFT TO A MORE
EAST-SOUTHEAST DIRECTION THIS AFTERNOON.
* CHANCE FOR SHRA/TSRA TO MOVE ACROSS LATE TONIGHT/EARLY SUNDAY
MORNING.
PAW
//DISCUSSION...UPDATED 12Z...
STRATUS REMAINS THE MAIN CONCERN THIS MORNING. MIX OF IFR/LOW MVFR
CIGS ACROSS THE TERMINALS AT ISSUANCE TIME. MAY STILL SEE A
SLIGHT LOWERING OVER THE NEXT 1-2 HOURS BUT EXPECT A SLOW UPWARD
TREND FROM THAT POINT ONWARD THROUGH THE MORNING. SCATTERING IS
EXPECTED TO OCCUR BY AROUND MIDDAY OR EARLY AFTERNOON BUT THE
SPECIFIC TIMING DETAILS MAY NEED SOME TWEAKING BUT HAVE GOOD
CONFIDENCE IN THE TREND. ONCE CLOUDS DO SCATTER VFR IS EXPECTED TO
PREVAIL INTO THE OVERNIGHT. WINDS WILL GENERALLY BE EAST TO
NORTHEAST WITH A TENDENCY TOWARD EAST-SOUTHEAST THIS
AFTERNOON...THOUGH GYY MAY SEE A CONTINUED NORTHEAST DIRECTION
UNTIL EARLY EVENING BEING CLOSE TO LAKE MICHIGAN.
NEXT CONCERN IS POTENTIAL FOR A BAND OF SHRA/TSRA TO MOVE ACROSS
THE TERMINALS LATE TONIGHT/EARLY SUNDAY MORNING. HAVE INCLUDED A
PROB30 MENTION EARLY SUNDAY. AT THIS POINT...BASED ON ATMOSPHERIC
SET UP...IMPACT DURATION WOULD BE ON THE ORDER OF A FEW HOURS BUT
THE TIME OF OCCURRENCE MAY NEED ADJUSTMENT.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE IN CIG TREND.
* HIGH CONFIDENCE IN WIND TREND.
* MEDIUM CONFIDENCE IN SHRA/TSRA OCCURRING LATE TONIGHT/EARLY SUNDAY
MORNING. LOW CONFIDENCE IN TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
MDB
&&
.MARINE...
257 AM CDT
HIGH PRESSURE SPREAD FROM HUDSON BAY SOUTH AND SOUTHWEST ACROSS LAKE
MICHIGAN CONTINUES TO PROVIDE NORTHEAST TO SOUTHEAST WINDS ACROSS
THE LAKE EARLY THIS MORNING. WINDS WILL TURN SOUTHERLY THIS
AFTERNOON AS THE RIDGE AXIS SHIFTS EASTWARD AND OUT OF THE AREA. LOW
PRESSURE ACROSS THE CANADIAN PRAIRIES WILL WEAKEN AS IT MOVES EAST
BUT THE PRESSURE GRADIENT BETWEEN THE RIDGE AND THE TROUGH WILL
BRING AN INCREASE IN SOUTHERLY WINDS TO NORTHERN SECTIONS OF THE
LAKE THIS EVENING. THE WEAKENED LOW WILL PASS TO THE NORTHEAST OF
LAKE MICHIGAN SUNDAY MORNING SHIFTING WINDS TO THE NORTHEAST ONCE
AGAIN DURING THE DAY SUNDAY. A RIDGE AXIS WILL THEN ARRIVE FROM THE
NORTH SUNDAY EVENING BRINGING WINDS MORE TO THE SOUTHEAST BUT
ANOTHER LOW WILL PASS TO THE SOUTH OF THE LAKE TUESDAY MORNING
BRINGING A RETURN OF NORTHERLY WINDS. HIGH PRESSURE IS EXPECTED TO
RETURN LATER TUESDAY AND REMAIN IN PLACE THROUGH THE END OF THE
WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1040 AM CDT SAT MAR 31 2012
.DISCUSSION...
ISSUED 1040 AM CDT SAT MAR 31 2012
LOW STRATUS DECK COVERED MUCH OF CENTRAL AND SOUTHEAST THIS
MORNING. THIS MOISTURE WAS TRAPPED BENEATH A PRETTY STOUT
SUBSIDENCE INVERSION PER 12Z KILX/KDVN SOUNDINGS. THE INVERSION IS
STRONGER THAN FORECAST BY THE MODELS...AND HAS RESULTED IN A
SLOWER CLEARING TRENDS THAN PREVIOUSLY ANTICIPATED. HOWEVER...
RECENT VISIBLE SATELLITE LOOPS SHOW THE STRATUS STARTING TO ERODE
FROM THE SOUTHWEST. THIS CLEARING TREND IS EXPECTED TO CONTINUE AS
DIURNAL HEATING INCREASES...AND THE CLEARING TREND WILL ALSO BE
AIDED BY SURFACE WINDS TRENDING TO THE SOUTHEAST IN THE WAKE OF
THE SURFACE RIDGE AXIS CURRENTLY OVER THE AREA.
HAVE UPDATED GRIDS FOR SLOWER CLEARING TRENDS...AS WELL AS A
RELATED SLOWER TEMPERATURE WARM UP. ALSO KNOCKED A DEGREE OR TWO
OFF MAX TEMPERATURES ALONG/NORTH OF THE I-74 CORRIDOR WHERE SKIES
WILL CLEAR THE LATEST AND PRESENT TEMPS ARE 20 DEGREES BELOW
FORECAST HIGHS.
BAK
&&
.AVIATION...
ISSUED 645 AM CDT SAT MAR 31 2012...FOR THE 12Z TAFS
IFR/MVFR STRATUS HAS OVERSPREAD ALL THE TERMINAL SITES FROM THE
NORTHEAST. COLD LOW LEVEL FLOW HAS PERSISTED FROM HIGH PRESSURE
CENTERED TO THE NORTHEAST OF IL...IN EASTERN ONTARIO. THE SURFACE RIDGE
AXIS EXTENDS INTO CENTRAL ILLINOIS...AND IT WILL SLIDE EAST OF IL
TODAY...SETTING UP A MORE SOUTHEAST TO SOUTH FLOW WHICH SHOULD
HELP PUSH THE CLOUDS BACK TO THE NORTH. MIXING OF DRY AIR FROM
ALOFT WILL ALSO AID IN DISSIPATING THE LOW STRATUS CLOUDS. WE
EXPECT SPI AND DEC TO CLEAR OUT SOONEST...WITH SPI AT 15Z AND DEC
- 16Z. PIA/BMI/CMI WILL CLEAR OUT TOWARD EARLY AFTERNOON...UNLESS
MIXING BECOMES DEEPER TO TAP INTO A DEEPER DRY LAYER.
AT THE VERY LEAST...THE IFR CONDITIONS AT PIA AND BMI WILL LIFT TO
MVFR BY 15Z DUE TO DAYTIME HEATING AND THE ONSET OF MIXING. VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS BY 19Z-20Z.
INCREASING SUNSHINE THIS AFTERNOON WILL ALSO BOOST
MIXING...HELPING WINDS TO INCREASE INTO THE 12-14KT RANGE...AS
THEY VEER FROM ENE TO SE. WINDS WILL BECOME SOUTHERLY LATE TONIGHT
AS A STORM SYSTEM PASSES BY TO THE NORTH OF THE TERMINALS. WINDS
MAY INCREASE ABOVE 10KT AGAIN LATE IN RESPONSE TO THAT SHORTWAVE.
SHIMON
&&
.PREV DISCUSSION...
ISSUED 255 AM CDT SAT MAR 31 2012
THE COLD FRONT THAT PASSED THROUGH LAST EVENING WAS NEAR THE OHIO
RIVER EARLY THIS MORNING. NORTHEAST WINDS ARE BRINGING A STRATUS
DECK SOUTHEASTWARD...REACHING TAYLORVILLE AND MATTOON AT 3 AM.
SIGNIFICANT PUSH OF COOLER AIR HAS DROPPED TEMPERATURES INTO THE
40S UNDERNEATH THE CLOUDS.
INITIAL FORECAST CONCERNS INVOLVE TEMPERATURES TODAY WITH THE
EFFECTS OF ANY LINGERING CLOUD COVER...AS WELL AS MUCH WARMER
CONDITIONS FOR SUNDAY AND MONDAY. TIMING AND COVERAGE OF MIDWEEK
SHOWERS ARE ALSO AN ISSUE.
SHORT TERM...TODAY THROUGH MONDAY...
LATEST RUC AND HRRR MODELS SUGGESTING THAT THE CLOUD DECK SHOULD
TRACK A LITTLE FURTHER SOUTH IN THE NEXT FEW HOURS...BEFORE
BEGINNING TO ERODE. WITH THIS THINKING...HAVE TRENDED THE SKY
GRIDS TO BE MOSTLY SUNNY BY MIDDAY...EXCEPT PERHAPS OVER THE FAR
NORTH. SHOULD GET TEMPERATURES INTO THE 70S ACROSS THE
SOUTHWEST...WITH COOLER 60S NORTHEAST. A SLOWER THAN EXPECTED
CLOUD BREAKUP WOULD RESULT IN TEMPERATURES IN THAT AREA CLOSER TO
THE COOLER MET GUIDANCE...BUT HAVE GONE CLOSER TO THE WARMER MAV
MOS AT THE MOMENT.
LATEST MODEL SUITE SHOWING MCS DEVELOPMENT ACROSS EASTERN IOWA
OVERNIGHT...AS A FRONTAL BOUNDARY ESTABLISHES ITSELF FROM NORTHERN
IOWA TO LOWER MICHIGAN. LATEST ECMWF MODEL IS THE FURTHEST SOUTH
WITH THE TRACK...REACHING POTENTIALLY AS FAR SOUTH AS SPRINGFIELD
AND DECATUR BY SUNRISE. THE REMAINING MODELS HAVE THE MCS SKIMMING
THE NORTH/NORTHEAST BORDER. HAVE MAINTAINED THE RAIN CHANCES OVER
THE NORTHERN HALF OF THE CWA...PRIMARILY BETWEEN MIDNIGHT AND
SUNRISE...AND SCALED THEM BACK ACROSS THE SOUTH.
UPPER RIDGE PROGGED BY THE MODELS TO AMPLIFY OVER THE CENTRAL
UNITED STATES THIS WEEKEND...SHIFTING TO THE MISSISSIPPI VALLEY BY
EARLY MONDAY MORNING. PRETTY GOOD SLUG OF WARM AIR WILL SPREAD
OVER THE STATE...WITH 850 MB TEMPERATURES RISING TO NEAR 20C ON
MONDAY. HAVE CONTINUED WITH THE 80S FOR HIGHS FOR SUNDAY...BUT
WILL NEED TO MONITOR THE CIRRUS BLOWOFF FROM THE MCS WHICH MAY
HELP KEEP TEMPS FROM RISING QUITE AS MUCH. HOWEVER...HAVE BOOSTED
HIGHS ON MONDAY BY A FEW DEGREES FROM EARLIER FORECASTS...AS THAT
WARMER AIR AT 850 MB MIXES TOWARD THE SURFACE. MAY SEE SOME RECORD
HIGHS AGAIN...AS CURRENT VALUES ARE IN THE MID TO UPPER 80S.
MAV/MEX MOS GUIDANCE SUGGESTING SOME 90 DEGREE READINGS ARE
POSSIBLE ACROSS THE SOUTHWEST CWA.
LONG TERM...TUESDAY THROUGH FRIDAY...
UPPER LEVEL TROUGHING ACROSS THE DESERT SOUTHWEST LATE THIS
WEEKEND WILL CUT OFF INTO A CLOSED LOW...WHICH IS PROGGED TO DRIFT
INTO THE CENTRAL PLAINS BY MIDWEEK. EXTENDED RANGE MODELS STARTING
TO TREND NORTHWARD WITH THIS TRACK...WITH THE GFS THE FARTHEST
NORTH INTO SOUTHERN IOWA. CURRENTLY PREFER THE MORE SOUTHERN
SOLUTION SOUTH OF THE OHIO VALLEY. AN EXTENDED PERIOD OF RAIN IS
LIKELY OVER PORTIONS OF THE MID-MISSISSIPPI VALLEY...BUT DRY
EASTERLY WINDS ASSOCIATED WITH A HIGH OVER THE GREAT LAKES WILL
CAUSE SOME EROSION OF THE PRECIP ON THE NORTHEAST FLANK. THE
LATEST ECMWF SURGES THE PRECIPITATION MUCH FURTHER NORTH THAN ITS
EARLIER RUN AND COVERS MOST OF THE CWA...WHILE THE CANADIAN MODEL
IS MORE LIMITED TO THE SOUTHEAST. HAVE INTRODUCED SLIGHT CHANCE
POPS FOR NOW ACROSS THE SOUTHEAST CWA WEDNESDAY NIGHT AND
THURSDAY...AND THESE MAY NEED TO BE BOOSTED IN FUTURE PACKAGES AS
MODEL AGREEMENT BECOMES TIGHTER.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
941 AM CDT SAT MAR 31 2012
.DISCUSSION...
941 AM CDT
SOME CHANGES MADE TO THE GOING CLOUD AND TEMPERATURE TRENDS TO
SLOW THE CLEARING IN A FEW AREAS AND ACCORDINGLY STIFLE THE
TEMPERATURE RISE.
A BLANKET OF CLOUDS REMAIN OVER THE REGION THIS MORNING WITHIN
LOW-LEVEL RIDGING. RAOBS AND AMDAR MEASUREMENTS...AND SATELLITE
ESTIMATES...INDICATE THE CLOUD DEPTH BETWEEN 700 AND 1000 FT
THICK...WHICH IS CERTAINLY SHALLOW ENOUGH FOR THE FINAL DAY OF
MARCH THAT ONE WOULD THINK HOLES WILL BEGIN TO DEVELOP AND SPREAD
QUICKLY. EVEN SOME FURTHER SUBSIDENCE IS PREDICTED THE NEXT FEW
HOURS ABOVE THE CLOUD LAYER TO AID THAT. THE LATEST HRRR AND 31.12
NAM INDICATE SOME SCATTERING OVER LAKE MI INTO FAR NORTHEAST IL
AND NORTHWEST IN THROUGH THE NEXT FEW HOURS....WHICH MAKES DECENT
SENSE WITH DECREASING DEW POINTS WORKING IN FROM THAT DIRECTION.
ALSO A BREAK DOWN IN CLOUDS IS FAVORED IN RELATIVE HUMIDITY FIELDS
ACROSS THE SOUTH AND THE WEST.
THE ONE AREA THAT IS SHOWING SOMEWHAT OF A CONSISTENT SIGNAL TO BE
CLOUDED IN POTENTIALLY THROUGH MID TO LATE AFTERNOON IS THE
WINNEBAGO...BOONE... MCHENRY...DEKALB...AND KANE COUNTY AREAS.
OBVIOUSLY THAT IS A SPECIFIC AREA...BUT THE IDEA THAT TOWARD THE
WISCONSIN STATE LINE AWAY FROM THE DRY ADVECTION FROM THE EAST
WILL BE ONE OF THE FINAL AREAS TO CLEAR SEEMS REASONABLE. WITH
ONLY 2 TO 4 DEGREES OR SO MORE OF WARMING THROUGH NOON UNDER
OVERCAST SKY...WENT AHEAD AND CUT THEIR HIGH TEMPERATURE BY
SEVERAL DEGREES...AND TOOK 1 TO 2 DEGREES OFF ELSEWHERE. WITH THE
EASTERLY FLOW OFF THE LAKE...BORDERING LAKE COUNTIES OF NORTHEAST
IL ALSO SHOULD NOT CLIMB TOO RAPIDLY THIS AFTERNOON...WITH HIGHS
AT OR JUST A TAD ABOVE NORMAL. STILL LOWER TO MID 60S EXPECTED
ACROSS THE FAR SOUTH AND WEST.
MTF
&&
.PREV DISCUSSION...
257 AM CDT
TODAY AND TONIGHT...RIDGE AXIS IN PLACE WITH EXPANSIVE AREA OF
STRATUS TRAPPED UNDER STRONG INVERSION EARLY THIS MORNING. EXPECT
CLOUD COVER TO ERODE BY LATE MORNING OR EARLY AFTERNOON UNDER
ANTICYCLONIC FLOW AND SUBSIDENCE. TEMPERATURES WILL THEN WARM INTO
THE LOW TO MID 60S AWAY FROM THE LAKE FRONT. NORTHEASTERLY FLOW OFF
THE LAKE WILL KEEP TEMPERATURES IN THE LOW TO MID 50S CLOSER TO THE
LAKEFRONT TODAY. THIS AFTERNOON...MOISTURE POOLING IS EXPECTED
ACROSS MISSOURI INTO CENTRAL IOWA WHERE DEW POINTS ARE EXPECTED TO
RISE INTO THE LOW 60S AS WARM FRONT LIFTS BACK NORTH. BY
TONIGHT...ISENTROPIC ASCENT WILL INCREASE WITH SHOWERS AND
THUNDERSTORMS DEVELOPING ALONG THE MOISTURE AXIS OVER PORTIONS OF
IOWA AND PUSHING EAST ON THE NOSE OF 40KT LOW LEVEL JET INTO
NORTHERN ILLINOIS LATE TONIGHT. SURFACE WINDS WILL VEER TO THE
SOUTHEAST WITH WARM ADVECTION OVERNIGHT HELPING TO PROP UP
TEMPERATURES...WHICH ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOW
50S BY LATE EVENING THE HOLD STEADY OR SLOWLY RISE OVERNIGHT.
SUNDAY...WARM FRONT DOES NOT ADVANCE MUCH DURING THE DAY SUNDAY WITH
A NORTHERN STREAM SYSTEM DROPPING SOUTHEAST ACROSS QUEBEC AND
TURNING FLOW BACK TO THE NORTHEAST FOR AT LEAST NORTHERN PORTIONS OF
THE FORECAST AREA. APPEARS THAT WITH THE FRONTAL BOUNDARY LINGERING
THROUGH THE DAY SUNDAY THAT WE WILL SET UP A STRONG TEMP GRADIENT
ACROSS THE CWA. ECMWF HAS COME MORE IN LINE WITH THIS SOLUTION WHICH
GFS HAS BEEN ADVERTISING THE PAST COUPLE DAYS. DROPPED TEMPERATURES
SEVERAL DEGREES ALONG THE LAKE SHORE AND WENT WITH NON-DIURNAL
TREND...SHOWING TEMPERATURES PEAKING EARLY IN THE DAY THEN DROPPING
AS LAKE AIR SPREADS INLAND WITH THE HELP OF SYNOPTICALLY NORTHEAST
FLOW. LINGERING SHOWERS AND CLOUD COVER IN THE MORNING ADD
ADDITIONAL UNCERTAINTY TO TEMPERATURE FORECAST...PARTICULARLY IN THE
WARMER AIR ACROSS EAST CENTRAL ILLINOIS.
MONDAY...GUIDANCE STILL A BIT MIXED ON HOW FAR NORTH THE WARM FRONT
WILL LIFT WITH GFS A SLOW/SOUTHERN OUTLIER AND PLACING PRECIP ALONG
THE WARM FRONT ACROSS NORTHERN ILLINOIS. OPTED TO KEEP FORECAST DRY
PER NAM/GEM/ECMWF SOLUTIONS WITH DRY AIR IN PLACE...DEEP MIXING
LAYERS AND VERY WARM TEMPERATURES. BUMPED UP TEMPS...ESPECIALLY
ACROSS THE SOUTH. BIAS CORRECTED NAM/ECMWF SHOW TEMPS SOARING INTO
THE 90S SOUTH OF THE I-80 CORRIDOR. SREF PLUMES SUPPORT MID 80S
ACROSS THE SOUTHERN PORTIONS OF THE CWA WITH STRONG CLUSTERING IN
THAT RANGE BUT A FEW SIGNIFICANT COLD OUTLIERS PULLING THE MEAN
INTO THE LOW 80S. MODEL CONSENSUS BLEND ALSO SUPPORTS MID 80S
ACROSS THE SOUTH. LAKE BREEZE IS POSSIBLE WITH MARGINAL WINDS
SPEEDS ALOFT SO MAY SEE TEMPERATURES COOL ALONG THE LAKE FRONT
THAT AFTERNOON.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL SWEEP ACROSS THE REGION
TUESDAY BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS
WHILE USHERING IN MORE SEASONABLE TEMPERATURES FOR THE REMAINDER OF
THE WEEK. HIGH PRESSURE BUILDS ACROSS THE GREAT LAKES REGION
WEDNESDAY AND LINGERS THROUGH THE END OF THE WEEK. DRY CONDITIONS
SHOULD PERSIST WITH PLENTY OF SUNSHINE. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* CIGS AROUND 010 EXPECTED TO SLOWLY RISE THROUGH THE
MORNING...THEN SCATTER MIDDAY OR EARLY AFTERNOON.
* EAST TO NORTHEAST WIND DIRECTION THROUGH THE MORNING WITH A
TREND TOWARD A MORE EAST-SOUTHEAST DIRECTION THIS AFTERNOON.
* CHANCE FOR SHRA/TSRA TO MOVE ACROSS LATE TONIGHT/EARLY SUNDAY
MORNING.
PAW
//DISCUSSION...UPDATED 12Z...
STRATUS REMAINS THE MAIN CONCERN THIS MORNING. MIX OF IFR/LOW MVFR
CIGS ACROSS THE TERMINALS AT ISSUANCE TIME. MAY STILL SEE A
SLIGHT LOWERING OVER THE NEXT 1-2 HOURS BUT EXPECT A SLOW UPWARD
TREND FROM THAT POINT ONWARD THROUGH THE MORNING. SCATTERING IS
EXPECTED TO OCCUR BY AROUND MIDDAY OR EARLY AFTERNOON BUT THE
SPECIFIC TIMING DETAILS MAY NEED SOME TWEAKING BUT HAVE GOOD
CONFIDENCE IN THE TREND. ONCE CLOUDS DO SCATTER VFR IS EXPECTED TO
PREVAIL INTO THE OVERNIGHT. WINDS WILL GENERALLY BE EAST TO
NORTHEAST WITH A TENDENCY TOWARD EAST-SOUTHEAST THIS
AFTERNOON...THOUGH GYY MAY SEE A CONTINUED NORTHEAST DIRECTION
UNTIL EARLY EVENING BEING CLOSE TO LAKE MICHIGAN.
NEXT CONCERN IS POTENTIAL FOR A BAND OF SHRA/TSRA TO MOVE ACROSS
THE TERMINALS LATE TONIGHT/EARLY SUNDAY MORNING. HAVE INCLUDED A
PROB30 MENTION EARLY SUNDAY. AT THIS POINT...BASED ON ATMOSPHERIC
SET UP...IMPACT DURATION WOULD BE ON THE ORDER OF A FEW HOURS BUT
THE TIME OF OCCURRENCE MAY NEED ADJUSTMENT.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM CONFIDENCE IN CIG TREND AND DETAILS.
* HIGH CONFIDENCE IN WIND TREND.
* MEDIUM CONFIDENCE IN SHRA/TSRA OCCURRING LATE TONIGHT/EARLY SUNDAY
MORNING. LOW CONFIDENCE IN TIMING.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...VFR WITH CHANCE TSRA MONDAY NIGHT.
TUESDAY...VFR WITH CHANCE SHRA EARLY.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...VFR.
MDB
&&
.MARINE...
257 AM CDT
HIGH PRESSURE SPREAD FROM HUDSON BAY SOUTH AND SOUTHWEST ACROSS LAKE
MICHIGAN CONTINUES TO PROVIDE NORTHEAST TO SOUTHEAST WINDS ACROSS
THE LAKE EARLY THIS MORNING. WINDS WILL TURN SOUTHERLY THIS
AFTERNOON AS THE RIDGE AXIS SHIFTS EASTWARD AND OUT OF THE AREA. LOW
PRESSURE ACROSS THE CANADIAN PRAIRIES WILL WEAKEN AS IT MOVES EAST
BUT THE PRESSURE GRADIENT BETWEEN THE RIDGE AND THE TROUGH WILL
BRING AN INCREASE IN SOUTHERLY WINDS TO NORTHERN SECTIONS OF THE
LAKE THIS EVENING. THE WEAKENED LOW WILL PASS TO THE NORTHEAST OF
LAKE MICHIGAN SUNDAY MORNING SHIFTING WINDS TO THE NORTHEAST ONCE
AGAIN DURING THE DAY SUNDAY. A RIDGE AXIS WILL THEN ARRIVE FROM THE
NORTH SUNDAY EVENING BRINGING WINDS MORE TO THE SOUTHEAST BUT
ANOTHER LOW WILL PASS TO THE SOUTH OF THE LAKE TUESDAY MORNING
BRINGING A RETURN OF NORTHERLY WINDS. HIGH PRESSURE IS EXPECTED TO
RETURN LATER TUESDAY AND REMAIN IN PLACE THROUGH THE END OF THE
WEEK.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
645 AM CDT SAT MAR 31 2012
.DISCUSSION...
ISSUED 255 AM CDT SAT MAR 31 2012
THE COLD FRONT THAT PASSED THROUGH LAST EVENING WAS NEAR THE OHIO
RIVER EARLY THIS MORNING. NORTHEAST WINDS ARE BRINGING A STRATUS
DECK SOUTHEASTWARD...REACHING TAYLORVILLE AND MATTOON AT 3 AM.
SIGNIFICANT PUSH OF COOLER AIR HAS DROPPED TEMPERATURES INTO THE
40S UNDERNEATH THE CLOUDS.
INITIAL FORECAST CONCERNS INVOLVE TEMPERATURES TODAY WITH THE
EFFECTS OF ANY LINGERING CLOUD COVER...AS WELL AS MUCH WARMER
CONDITIONS FOR SUNDAY AND MONDAY. TIMING AND COVERAGE OF MIDWEEK
SHOWERS ARE ALSO AN ISSUE.
SHORT TERM...TODAY THROUGH MONDAY...
LATEST RUC AND HRRR MODELS SUGGESTING THAT THE CLOUD DECK SHOULD
TRACK A LITTLE FURTHER SOUTH IN THE NEXT FEW HOURS...BEFORE
BEGINNING TO ERODE. WITH THIS THINKING...HAVE TRENDED THE SKY
GRIDS TO BE MOSTLY SUNNY BY MIDDAY...EXCEPT PERHAPS OVER THE FAR
NORTH. SHOULD GET TEMPERATURES INTO THE 70S ACROSS THE
SOUTHWEST...WITH COOLER 60S NORTHEAST. A SLOWER THAN EXPECTED
CLOUD BREAKUP WOULD RESULT IN TEMPERATURES IN THAT AREA CLOSER TO
THE COOLER MET GUIDANCE...BUT HAVE GONE CLOSER TO THE WARMER MAV
MOS AT THE MOMENT.
LATEST MODEL SUITE SHOWING MCS DEVELOPMENT ACROSS EASTERN IOWA
OVERNIGHT...AS A FRONTAL BOUNDARY ESTABLISHES ITSELF FROM NORTHERN
IOWA TO LOWER MICHIGAN. LATEST ECMWF MODEL IS THE FURTHEST SOUTH
WITH THE TRACK...REACHING POTENTIALLY AS FAR SOUTH AS SPRINGFIELD
AND DECATUR BY SUNRISE. THE REMAINING MODELS HAVE THE MCS SKIMMING
THE NORTH/NORTHEAST BORDER. HAVE MAINTAINED THE RAIN CHANCES OVER
THE NORTHERN HALF OF THE CWA...PRIMARILY BETWEEN MIDNIGHT AND
SUNRISE...AND SCALED THEM BACK ACROSS THE SOUTH.
UPPER RIDGE PROGGED BY THE MODELS TO AMPLIFY OVER THE CENTRAL
UNITED STATES THIS WEEKEND...SHIFTING TO THE MISSISSIPPI VALLEY BY
EARLY MONDAY MORNING. PRETTY GOOD SLUG OF WARM AIR WILL SPREAD
OVER THE STATE...WITH 850 MB TEMPERATURES RISING TO NEAR 20C ON
MONDAY. HAVE CONTINUED WITH THE 80S FOR HIGHS FOR SUNDAY...BUT
WILL NEED TO MONITOR THE CIRRUS BLOWOFF FROM THE MCS WHICH MAY
HELP KEEP TEMPS FROM RISING QUITE AS MUCH. HOWEVER...HAVE BOOSTED
HIGHS ON MONDAY BY A FEW DEGREES FROM EARLIER FORECASTS...AS THAT
WARMER AIR AT 850 MB MIXES TOWARD THE SURFACE. MAY SEE SOME RECORD
HIGHS AGAIN...AS CURRENT VALUES ARE IN THE MID TO UPPER 80S.
MAV/MEX MOS GUIDANCE SUGGESTING SOME 90 DEGREE READINGS ARE
POSSIBLE ACROSS THE SOUTHWEST CWA.
LONG TERM...TUESDAY THROUGH FRIDAY...
UPPER LEVEL TROUGHING ACROSS THE DESERT SOUTHWEST LATE THIS
WEEKEND WILL CUT OFF INTO A CLOSED LOW...WHICH IS PROGGED TO DRIFT
INTO THE CENTRAL PLAINS BY MIDWEEK. EXTENDED RANGE MODELS STARTING
TO TREND NORTHWARD WITH THIS TRACK...WITH THE GFS THE FARTHEST
NORTH INTO SOUTHERN IOWA. CURRENTLY PREFER THE MORE SOUTHERN
SOLUTION SOUTH OF THE OHIO VALLEY. AN EXTENDED PERIOD OF RAIN IS
LIKELY OVER PORTIONS OF THE MID-MISSISSIPPI VALLEY...BUT DRY
EASTERLY WINDS ASSOCIATED WITH A HIGH OVER THE GREAT LAKES WILL
CAUSE SOME EROSION OF THE PRECIP ON THE NORTHEAST FLANK. THE
LATEST ECMWF SURGES THE PRECIPITATION MUCH FURTHER NORTH THAN ITS
EARLIER RUN AND COVERS MOST OF THE CWA...WHILE THE CANADIAN MODEL
IS MORE LIMITED TO THE SOUTHEAST. HAVE INTRODUCED SLIGHT CHANCE
POPS FOR NOW ACROSS THE SOUTHEAST CWA WEDNESDAY NIGHT AND
THURSDAY...AND THESE MAY NEED TO BE BOOSTED IN FUTURE PACKAGES AS
MODEL AGREEMENT BECOMES TIGHTER.
GEELHART
&&
.AVIATION...
ISSUED 645 AM CDT SAT MAR 31 2012...FOR THE 12Z TAFS
IFR/MVFR STRATUS HAS OVERSPREAD ALL THE TERMINAL SITES FROM THE
NORTHEAST. COLD LOW LEVEL FLOW HAS PERSISTED FROM HIGH PRESSURE
CENTERED TO THE NORTHEAST OF IL...IN EASTERN ONTARIO. THE SURFACE RIDGE
AXIS EXTENDS INTO CENTRAL ILLINOIS...AND IT WILL SLIDE EAST OF IL
TODAY...SETTING UP A MORE SOUTHEAST TO SOUTH FLOW WHICH SHOULD
HELP PUSH THE CLOUDS BACK TO THE NORTH. MIXING OF DRY AIR FROM
ALOFT WILL ALSO AID IN DISSIPATING THE LOW STRATUS CLOUDS. WE
EXPECT SPI AND DEC TO CLEAR OUT SOONEST...WITH SPI AT 15Z AND DEC
- 16Z. PIA/BMI/CMI WILL CLEAR OUT TOWARD EARLY AFTERNOON...UNLESS
MIXING BECOMES DEEPER TO TAP INTO A DEEPER DRY LAYER.
AT THE VERY LEAST...THE IFR CONDITIONS AT PIA AND BMI WILL LIFT TO
MVFR BY 15Z DUE TO DAYTIME HEATING AND THE ONSET OF MIXING. VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS BY 19Z-20Z.
INCREASING SUNSHINE THIS AFTERNOON WILL ALSO BOOST
MIXING...HELPING WINDS TO INCREASE INTO THE 12-14KT RANGE...AS
THEY VEER FROM ENE TO SE. WINDS WILL BECOME SOUTHERLY LATE TONIGHT
AS A STORM SYSTEM PASSES BY TO THE NORTH OF THE TERMINALS. WINDS
MAY INCREASE ABOVE 10KT AGAIN LATE IN RESPONSE TO THAT SHORTWAVE.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
256 AM CDT SAT MAR 31 2012
.DISCUSSION...
ISSUED 255 AM CDT SAT MAR 31 2012
THE COLD FRONT THAT PASSED THROUGH LAST EVENING WAS NEAR THE OHIO
RIVER EARLY THIS MORNING. NORTHEAST WINDS ARE BRINGING A STRATUS
DECK SOUTHEASTWARD...REACHING TAYLORVILLE AND MATTOON AT 3 AM.
SIGNIFICANT PUSH OF COOLER AIR HAS DROPPED TEMPERATURES INTO THE
40S UNDERNEATH THE CLOUDS.
INITIAL FORECAST CONCERNS INVOLVE TEMPERATURES TODAY WITH THE
EFFECTS OF ANY LINGERING CLOUD COVER...AS WELL AS MUCH WARMER
CONDITIONS FOR SUNDAY AND MONDAY. TIMING AND COVERAGE OF MIDWEEK
SHOWERS ARE ALSO AN ISSUE.
SHORT TERM...TODAY THROUGH MONDAY...
LATEST RUC AND HRRR MODELS SUGGESTING THAT THE CLOUD DECK SHOULD
TRACK A LITTLE FURTHER SOUTH IN THE NEXT FEW HOURS...BEFORE
BEGINNING TO ERODE. WITH THIS THINKING...HAVE TRENDED THE SKY
GRIDS TO BE MOSTLY SUNNY BY MIDDAY...EXCEPT PERHAPS OVER THE FAR
NORTH. SHOULD GET TEMPERATURES INTO THE 70S ACROSS THE
SOUTHWEST...WITH COOLER 60S NORTHEAST. A SLOWER THAN EXPECTED
CLOUD BREAKUP WOULD RESULT IN TEMPERATURES IN THAT AREA CLOSER TO
THE COOLER MET GUIDANCE...BUT HAVE GONE CLOSER TO THE WARMER MAV
MOS AT THE MOMENT.
LATEST MODEL SUITE SHOWING MCS DEVELOPMENT ACROSS EASTERN IOWA
OVERNIGHT...AS A FRONTAL BOUNDARY ESTABLISHES ITSELF FROM NORTHERN
IOWA TO LOWER MICHIGAN. LATEST ECMWF MODEL IS THE FURTHEST SOUTH
WITH THE TRACK...REACHING POTENTIALLY AS FAR SOUTH AS SPRINGFIELD
AND DECATUR BY SUNRISE. THE REMAINING MODELS HAVE THE MCS SKIMMING
THE NORTH/NORTHEAST BORDER. HAVE MAINTAINED THE RAIN CHANCES OVER
THE NORTHERN HALF OF THE CWA...PRIMARILY BETWEEN MIDNIGHT AND
SUNRISE...AND SCALED THEM BACK ACROSS THE SOUTH.
UPPER RIDGE PROGGED BY THE MODELS TO AMPLIFY OVER THE CENTRAL
UNITED STATES THIS WEEKEND...SHIFTING TO THE MISSISSIPPI VALLEY BY
EARLY MONDAY MORNING. PRETTY GOOD SLUG OF WARM AIR WILL SPREAD
OVER THE STATE...WITH 850 MB TEMPERATURES RISING TO NEAR 20C ON
MONDAY. HAVE CONTINUED WITH THE 80S FOR HIGHS FOR SUNDAY...BUT
WILL NEED TO MONITOR THE CIRRUS BLOWOFF FROM THE MCS WHICH MAY
HELP KEEP TEMPS FROM RISING QUITE AS MUCH. HOWEVER...HAVE BOOSTED
HIGHS ON MONDAY BY A FEW DEGREES FROM EARLIER FORECASTS...AS THAT
WARMER AIR AT 850 MB MIXES TOWARD THE SURFACE. MAY SEE SOME RECORD
HIGHS AGAIN...AS CURRENT VALUES ARE IN THE MID TO UPPER 80S.
MAV/MEX MOS GUIDANCE SUGGESTING SOME 90 DEGREE READINGS ARE
POSSIBLE ACROSS THE SOUTHWEST CWA.
LONG TERM...TUESDAY THROUGH FRIDAY...
UPPER LEVEL TROUGHING ACROSS THE DESERT SOUTHWEST LATE THIS
WEEKEND WILL CUT OFF INTO A CLOSED LOW...WHICH IS PROGGED TO DRIFT
INTO THE CENTRAL PLAINS BY MIDWEEK. EXTENDED RANGE MODELS STARTING
TO TREND NORTHWARD WITH THIS TRACK...WITH THE GFS THE FARTHEST
NORTH INTO SOUTHERN IOWA. CURRENTLY PREFER THE MORE SOUTHERN
SOLUTION SOUTH OF THE OHIO VALLEY. AN EXTENDED PERIOD OF RAIN IS
LIKELY OVER PORTIONS OF THE MID-MISSISSIPPI VALLEY...BUT DRY
EASTERLY WINDS ASSOCIATED WITH A HIGH OVER THE GREAT LAKES WILL
CAUSE SOME EROSION OF THE PRECIP ON THE NORTHEAST FLANK. THE
LATEST ECMWF SURGES THE PRECIPITATION MUCH FURTHER NORTH THAN ITS
EARLIER RUN AND COVERS MOST OF THE CWA...WHILE THE CANADIAN MODEL
IS MORE LIMITED TO THE SOUTHEAST. HAVE INTRODUCED SLIGHT CHANCE
POPS FOR NOW ACROSS THE SOUTHEAST CWA WEDNESDAY NIGHT AND
THURSDAY...AND THESE MAY NEED TO BE BOOSTED IN FUTURE PACKAGES AS
MODEL AGREEMENT BECOMES TIGHTER.
GEELHART
&&
.AVIATION...
ISSUED 1115 PM CDT FRI MAR 30 2012
MVFR CIGS CONTINUE TO SETTLE SLOWLY SOUTH ACRS THE FORECAST AREA
LATE THIS EVENING. 1500-2000 FOOT CIGS HAVE SPREAD AS FAR SOUTH
AS A DNV-BMI-PIA LINE AND EXPECT THE SOUTHWARD DRIFT TO CONTINUE
THRU THE EARLY MORNING HOURS. CONFIDENCE ON JUST HOW FAR SOUTH THE
CLOUDS WILL GO IS RATHER LOW AS MODELS HAVING A DIFFICULT TIME
PICKING UP THE MOISTURE AT THIS LAYER. LOW LEVEL WIND FORECASTS
SUGGEST THE CLOUDS WILL CONTINUE TO SINK SOUTH OVERNIGHT BEFORE
THE BOUNDARY LAYER WINDS GO MORE EAST TO SOUTHEAST TOMORROW...
WHICH WOULD START TO SHIFT THE CLOUDS BACK TO THE WNW. WILL TIME
THE CLOUDS INTO THE SITES TONIGHT THAT HAVE NOT ALREADY SEEN THEM
MOVE IN...AND THEN KEEP THEM IN THRU AT LEAST MID MORNING SATURDAY
BEFORE A DECREASE IN CLOUD COVER IS SEEN. LOOKS AS IF DECATUR AND
SPRINGFIELD WILL BE THE LAST TO SEE THE CLOUDS MOVE IN OVERNIGHT
WITH TIMING IN THE 0630-0730Z RANGE.
SFC WINDS WILL CONTINUE TO GRADUALLY VEER MORE INTO A NORTHEAST
TO EAST DIRECTION OVERNIGHT...AND THEN VEER MORE INTO THE SE AS
THE DAY WEARS ON SATURDAY. SPEEDS TONIGHT AND SATURDAY WILL RANGE
FROM 8 TO 15 KTS.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
846 PM MDT SUN APR 1 2012
.UPDATE...
ISSUED AT 846 PM MDT SUN APR 1 2012
MADE FURTHER ADJUSTMENTS TO WIND FORECAST IN THE 06-15Z PERIOD
BASED ON LATEST RUC AND NAM TIMING OF FROPA. 00Z NAM STILL
INDICATING HIGH END ADVISORY/NEAR WARNING CRITERIA WINDS EARLY
MONDAY MORNING OVER EASTERN COLORADO. 00Z NAM AND LATEST SREF AND
RUC ARE LESS BULLISH THAN EARLIER ON WARNING CRITERIA. I HAVE
KEPT ADVISORY IN PLACE FOR NOW...AND WILL PROBABLY WAIT FOR 00Z
GFS TO MAKE FINAL DECISION ON FURTHER ADJUSTMENTS OR POSSIBLE
UPGRADES.
UPDATE ISSUED AT 554 PM MDT SUN APR 1 2012
MADE MINOR CHANGES TO WIND FORECAST TO ACCOUNT FOR WINDS
INCREASING QUICKER OVER WESTERN PARTS OF CWA AFTER 09Z TONIGHT AND
TO BUMP UP WIND GUST WORDING. I ALSO ADDED PATCHY BLOWING
DUST TO WEATHER GRIDS. IM CONCERNED WE COULD SEE WARNING CRITERIA
WINDS OVER WESTERN PARTS OF THE CWA MONDAY MORNING...HOWEVER NOT
A LOT OF NEW DATA TO LOOK AT AND MAKE A DECISION YET. WILL
PROBABLY WAIT UNTIL 00Z DATA COMES IN TO FURTHER FINE TUNE WIND
FORECAST. OTHER CHANGE WAS TO ADJUST TIMING OF PRECIP
MONDAY...TO INCLUDE RAIN SHOWERS MONDAY AFTERNOON IN THE SOUTH AND
WEST. 18Z NAM/GFS BOTH INDICATING AXIS OF FRONTOGENISIS MOVING NORTH
AND EAST ALONG WITH DECENT MID LEVEL MOISTURE IN THE 21-00Z
TIME-FRAME...SO EARLIER ARRIVAL OF RAIN CANT BE RULED OUT.
RED FLAG CONDITIONS CONTINUE OVER MANY LOCATIONS ACROSS THE
AREA...SO I PLAN ON LETTING THE RFW EXPIRE ON TIME AT 02Z.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 238 PM MDT SUN APR 1 2012
SOUTHWEST FLOW WILL BE OVER THE REGION TONIGHT. THE UPPER LOW WILL
MOVE INTO SOUTHWEST NEW MEXICO MONDAY. A SURFACE TROUGH WILL BE OVER
EASTERN COLORADO TONIGHT. A COLD FRONT WILL PUSH SOUTH ACROSS
NORTHWEST KANSAS EARLY MONDAY.
SUBSIDENCE WILL CONTINUE OVER THE FA TONIGHT SO POPS WILL BE NIL.
SOME LIGHT PRECIPITATION WILL BE POSSIBLE MONDAY MORNING OVER
WESTERN PORTIONS OF EASTERN COLORADO WHILE DYNAMICS FROM THE UPPER
LOW ARE STILL REASONABLY CLOSE. BY MONDAY AFTERNOON THE LOW WILL
MOVE FAR ENOUGH SOUTH SO THAT CHANCES ARE MUCH LOWER. PLAN TO
CONTINUE SLIGHT CHANCE POPS IN EASTERN COLORADO MONDAY MORNING AND
THEN SILENT POPS MONDAY AFTERNOON. THE REST OF THE FA WILL HAVE NIL
POPS.
STRONG WINDS ARE THE MAIN FOCUS OF THE FORECAST FOR MONDAY. THE
GFS/NAM BOTH INDICATE GUSTS TO AROUND 50 MPH BETWEEN 12-15Z.
SUSTAINED WIND WILL BE STRONG ENOUGH TO SUPPORT A WIND ADVISORY ALL
DAY. SEE DETAILS ON THE WIND ADVISORY BELOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 238 PM MDT SUN APR 1 2012
MONDAY NIGHT WINDS WILL REMAIN GUSTY THROUGH THE NIGHT...WITH THE
STRONGEST GUSTS DURING THE EVENING...AS THE COOLER TEMPERATURES
ABOVE THE GROUND ALLOW THE STRONG WINDS TO MIX TO THE SURFACE. AS
SUCH HAVE THE WIND ADVISORY EXTENDING INTO THE EVENING. DURING THE
LATE EVENING THE WINDS WILL SLOWLY DECLINE AS THE COOLER
TEMPERATURES AT THE SURFACE CAUSE MIXING TO DECLINE.
THERE STILL REMAINS SOME UNCERTAINTY WITH TRACK OF THE CLOSED UPPER
LEVEL LOW MONDAY NIGHT THROUGH WEDNESDAY. MODELS IN GENERAL HAVE
SLOWED THE SYSTEM DOWN FROM YESTERDAY...WHICH SEEMS REASONABLE SINCE
THE CLOSED LOW WILL BE OUTSIDE OF THE MAIN UPPER LEVEL FLOW. THE
12Z NAM IS FURTHER SOUTH THAN IT WAS AT THIS TIME YESTERDAY WHILE
THE 12Z GFS IS FURTHER NORTH. PREFERENCE IS THE SREF AND NAM SINCE
THEY ARE SLOWER AND HAVE MORE RUN TO RUN CONSISTENCY WITH THE TRACK
OF THE CLOSED LOW AND ARE IN LINE WITH THE MAJORITY OF THE 6Z
GEFS...BUT FAVORED MOSTLY THE SREF FOR DETERMINING AREAS OF PRECIP.
SINCE THE NAM DRASTICALLY CUT BACK THE PRECIP. FOR THIS STORM
SYSTEM. GENERALLY THINKING A SLOWER TREND OF THE PRECIPITATION
MONDAY NIGHT THROUGH TUESDAY EVENING LOOKS TO BE THE WAY TO
GO...WITH LOCATIONS SOUTH OF HIGHWAY 24 LOOKING TO HAVE THE BEST
CHANCE FOR PRECIPITATION UNTIL THE STORM SYSTEM MOVES FURTHER EAST.
MONDAY EVENING HAVE SLIGHT CHANCES FOR PRECIPITATION OVER EASTERN
COLORADO AS THE 750-650MB SATURATES WITH ISENTROPIC LIFT OVER THAT
AREA. OVERNIGHT PRECIP. CHANCES INCREASE OVER THE ENTIRE AREA FROM
SOUTHWEST TO NORTHEAST AS ISENTROPIC LIFT OVERSPREADS THE AREA AND
MOISTURE AHEAD OF THE CLOSED LOW BEGINS TO MOVE NORTH INTO THE
AREA. SOME LOCATIONS IN EASTERN COLORADO MAY RECEIVE SOME SNOW WITH
LOW TEMPERATURES AROUND FREEZING.
TUESDAY PRECIP. CHANCES SLOWLY INCREASE AS THE CIRCULATION OF THE
CLOSED LOW CONTINUES TO BRING MOISTURE INTO THE AREA. BIGGEST
QUESTION IS HOW FAR NORTH THE MOISTURE WILL MAKE IT AS THE CLOSED
LOW MOVES EAST. WITH MORE UNCERTAINTY THAT THERE WILL BE MOISTURE
FOR THE ISENTROPIC LIFT TO WORK WITH AS ONE MOVES NORTH...HAVE
PRECIP. CHANCES DECREASING TO THE NORTH. WINDS WILL CONTINUE TO
DECREASE AS THE UPPER LEVEL WINDS DECLINE...BECOMING LIGHT BY
EVENING.
TUESDAY NIGHT PRECIPITATION CHANCES BEGIN TO DECREASE FROM EAST TO
WEST AS THE CLOSED LOW AND WRAP AROUND MOISTURE MOVE EAST.
FOR WEDNESDAY THROUGH SUNDAY THE MAIN FOCUS WILL BE THE CLOSED LOW
MOVING OUT OF THE AREA AND THUNDERSTORM CHANCES TOWARD THE END OF
THE WEEK.
WEDNESDAY THE CLOSED CONTINUES TO MOVE OUT OF THE AREA. BOTH THE
GFS AND ECMWF HAVE THE CLOSED LOW MOVING EAST OVER KANSAS...WHILE
THE NAM/SREF HAVE THE CLOSED LOW MOVING EAST OVER OKLAHOMA. DESPITE
THE DIFFERING POSITIONS OF THE LOW...THE MODELS AGREE THAT PRECIP.
CHANCES WILL DECLINE FROM EAST TO WEST DURING THE DAY AS THE CLOSED
LOW MOVES EAST. BEHIND THE CLOSED LOW A SHORT WAVE RIDGE MOVES OVER
THE AREA.
THURSDAY THE NEXT UPPER LEVEL TROUGH MOVES ON SHORE. BY FRIDAY
MORNING THE TROUGH WILL BE OVER THE INTER MOUNTAIN WEST. AT THE
SURFACE A LEE SIDE TROUGH DEVELOPS OVER EASTERN COLORADO AS THE
UPPER LEVEL TROUGH APPROACHES THE TRI-STATE AREA. FRIDAY SOUTHERLY
AHEAD OF AN UPPER LEVEL SHORT WAVE TROUGH BRING UP MOISTURE FROM
THE SOUTH. WITH INSTABILITY TO WORK WITH CANNOT RULE OUT A FEW
THUNDERSTORMS FROM FORMING OVER THE EASTERN PART OF THE AREA DURING
THE AFTERNOON. FRIDAY NIGHT A COLD FRONT MOVES THROUGH THE AREA.
OVER THE EAST THUNDERSTORM CHANCES CONTINUE WITH ELEVATED INSTABILITY
IN PLACE AND THE LOW LEVEL JET MOVING OVER THOSE AREAS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 531 PM MDT SUN APR 1 2012
VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE
PERIOD...HOWEVER...THERE IS A CHANCE FOR MVFR CIGS VERY LATE IN THE
PERIOD. HAVE HELD OFF ON MENTIONING AT THIS TIME AND WILL LET
SUBSEQUENT SHIFTS ANALYZE THIS. OTHERWISE...A COLD FRONT WILL PUSH
THROUGH THE AREA DURING THE MORNING HOURS. WINDS WILL SWITCH TO
THE NORTH AND BECOME WINDY WITH GUSTS IN THE 40 KNOT RANGE
LIKELY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY FROM 6 AM TO 9 PM MDT MONDAY FOR COZ090>092.
KS...WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR KSZ001>004-013>016-027>029-041-042.
NE...WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR NEZ079>081.
&&
$$
UPDATE...DR
SHORT TERM...FS
LONG TERM....JTL
AVIATION...BAS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1158 AM CDT SAT MAR 31 2012
...AVIATION SECTION UPDATED AT 1154 AM...
.UPDATE...
ISSUED AT 939 AM CDT SAT MAR 31 2012
A VERY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS WESTERN KANSAS
THROUGH THE MORNING HOURS. PRESSURES WILL FALL IN THE LEE OF THE
ROCKIES THIS AFTERNOON AS THE UPPER LEVEL TROUGH MOVING THROUGH
MANITOBA CONTINUES MOVING NORTHEAST AND THE STRONG UPPER LEVEL
TROUGH NEAR 130W REACHES THE WEST COAST. LOW LEVEL FLOW WILL
INCREASE FROM THE SOUTH AS THE ATMOSPHERE RESPONDS TO THE LEE
TROUGHING. TEMPERATURES THIS AFTERNOON MAY NOT BE QUITE AS WARM AS
ANTICIPATED DUE TO ANOMALOUSLY STRONG EVAPOTRANSPIRATION FROM
EARLY PLANT GROWTH AFTER THE HEAVY RAINFALL LAST WEEK. MINOR
DOWNWARD ADJUSTMENTS WERE MADE WHERE THE HEAVIEST RAIN FELL.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT SAT MAR 31 2012
.SYNOPSIS...
ISSUED AT 300 AM CDT SAT MAR 31 2012
THE 00Z 300 HPA SYNOPTIC MAP SHOWS A STRONG 140 KT JET TRAVERSING ACROSS
THE PACIFIC NORTHWEST. ACROSS THE PLAINS, 45 TO 65 KT NORTHWESTERLY
FLOW WAS OBSERVED IN THE WAKE OF A DEPARTING TROUGH AXIS LOCATED ACROSS
THE EASTERN PLAINS/MIDWEST. THE 500 HPA MAP SHOWED THAT VERY COLD AIR
OF -38 DEG C WAS OBSERVED ACROSS VANCOUVER ISLAND. IN THE LOWER LEVELS
(700 AND 850 HPA), A DRY AIRMASS WAS OVER THE PLAINS, PARTICULARLY ACROSS
THE NORTHERN PLAINS. SURFACE ANALYSIS FROM HPC SHOWED A LOW PRESSURE
SYSTEM WITH ASSOCIATED COLD AND WARM FRONTS MOVING ACROSS THE CANADIAN
PRAIRIES. HIGH PRESSURE WAS OVER THE CENTRAL AND SOUTHERN PLAINS. DEWPOINTS
CONTINUED TO BE IN THE MODERATE LEVELS (FOR END OF MARCH) WITH LOWER
TO MID 50S DEG F DEWPOINTS ACROSS SW AND SC KANSAS.
THIS MORNING:
THE MAIN FORECAST CONCERN FOR THIS MORNING IN TERMS OF SENSIBLE WEATHER
IS IF FOG WILL DEVELOP OR NOT. THE 01Z AND 02Z HRRR RUNS WERE VERY AGGRESSIVE
IN DEVELOPING DENSE FOG ACROSS THE SW/W KANSAS. THE 04Z HRRR RUN HAS
BACKED OFF ON THIS WITH A SMALLER AREA OF DENSE FOG MAINLY ACROSS HAMILTON
COUNTY. WHAT IS INTERESTING IS THAT EVEN THOUGH THE MODEL DEVELOPS THE
FOG, THE MODELS ALSO HAS DOWNSLOPE SSW AS THE SFC. THIS IS NOT CONDUCIVE
FOR DENSE FOG FORMATION ACROSS MY COUNTY WARNING AREA. VSREF ALSO SHOWED
SOME HIGHER PROBABILITIES FOR LOWER VIS ACROSS THE AREA. OTHER MODEL
GUIDANCE IS LESS SUGGESTIVE FOR FOG FORMATION. DESPITE THIS, OBSERVATIONS
ACROSS OKLAHOMA SHOW SOME PATCHY FOG DEVELOP THIS MORNING SO I HAVE
DECIDED TO MEET THE MODELS IN BETWEEN AND INSERT PATCHY FOG ACROSS MY
WESTERN COUNTIES. DEWPOINTS ARE CURRENTLY IN THE 50S DEG F WITH UPSLOPE
SE/S WINDS SO THE POTENTIAL CANNOT BE COMPLETELY DISMISSED ATTM.
TODAY:
500 HPA FLOW WILL BECOME MORE MORE WESTERLY THROUGH TODAY, WHICH WILL
STRENGTHEN LEE TROUGHING. AS A RESULT, A WARM AIR ADVECTION PATTERN
WILL BE IN PLACE TODAY WITH TEMPERATURES WARMING WELL ABOVE NORMAL.
MID 80S DEG F ARE EXPECTED FOR HIGHS TODAY, WHICH IS ABOUT 20 DEGREES
ABOVE NORMAL. THIS WARM MARCH WE HAVE BEEN EXPERIENCING WILL END ON
A VERY WARM NOTE FOR THE LAST DAY IN THE MONTH. TODAY WILL BE PRECIPITATION
FREE AS A FAIRLY FLAT UPPER LEVEL RIDGE PREVAILS ACROSS KANSAS. I HAVE
GONE WITH SLIGHTLY COOLER TEMPERATURES TODAY (MID 80S DEG F VERSUS UPPER
80S DEG F) AS RECENT VERIFICATION PER BOI VERIFY SHOWS THAT MODELS ARE
SUFFERING A BIT OF WARM BIAS. SOUTHERLY WINDS OF 15 TO 20 KT ARE EXPECTED
THIS AFTERNOON AS MIXING INCREASES TO ABOUT 750 HPA AND SOME STRONGER
WINDS MIX DOWN.
TONIGHT:
THE LEE SURFACE TROUGH AXIS WILL MOVE SLIGHTLY EASTWARD TONIGHT AND
FRAGMENT TOWARDS SUNDAY MORNING. THIS WILL KEEP SOUTHERLY WINDS IN THE
FORECAST OVERNIGHT. DEWPOINTS IN THE 30S DEG F WEST TO 50S DEG F EAST
WILL KEEP OVERNIGHT LOWS ON THE MILD SIDE, PARTICULARLY ACROSS SOUTH
CENTRAL KANSAS. HAVE AROUND 60 DEG F TOWARDS KP28 (MEDICINE LODGE, KS)
AND COOLER MID 40S NEAR K3K3 (SYRACUSE, KS).
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT MAR 31 2012
MODELS REMAINING VERY CONSISTENT WITH PREVIOUS RUNS AND KEEP
SUNDAY SUNNY AND WARM . 850MB 00Z MONDAY TEMPERATURES STILL
SUPPORT HIGHS AROUND 90 DEGREES FOR MUCH OF SOUTHWEST KANSAS.
THESE HIGHS FOR THE FIRST OF APRIL COULD EASILY SET NEW RECORD
HIGHS IN A FEW LOCATIONS. A FEW RECORDS FOR APRIL FIRST ARE....88
DEGREES AT DODGE CITY, 87 AT GARDEN CITY AND 93 DEGREES AT
MEDICINE LODGE.
IN ADDITION TO THIS UNSEASONABLY WARM TEMPERATURES...LOW DEW
POINTS WILL BE SPREADING INTO PORTIONS OF WESTERN KANSAS BEHIND A
DRYLINE. THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES
BOTTOMING OUT IN THE 10 TO 15 PERCENT RANGE IN SEVERAL LOCATIONS.
GIVEN THESE LOW RELATIVE HUMIDITIES ALONG WITH GUSTY SOUTHWEST
WINDS DEVELOPING DURING THE AFTERNOON HAVE DECIDED TO CONTINUE THE
FIRE WEATHER WATCH ACROSS MUCH OF WESTERN KANSAS.
FOR EARLY NEXT WEEK...OUR NEXT UPPER LEVEL STORM SYSTEM IS STILL
FORECAST BY THE GFS, ECMWF, AND CANADIAN TO CROSS THE FOUR CORNERS
REGION SUNDAY NIGHT. BY MONDAY THIS SYSTEM WILL BEGIN TO DEEPEN
ACROSS NEW MEXICO WHERE IT WILL MOVE VERY LITTLE THROUGH TUESDAY.
AHEAD OF THIS SYSTEM A SOUTHEAST FLOW WILL DRAW MORE HUMID AIR
NORTHWARD TOWARDS SOUTHWEST KANSAS ON MONDAY. IN ADDITION 850MB
WARM AIR ADVECTION AND 850-700 FRONTOGENESIS WILL BE ON THE
INCREASE LATE IN THE DAY ALONG AND JUST BEHIND A COLD FRONT WHICH
WILL BE CROSSING SOUTHERN KANSAS/NORTHERN OKLAHOMA. GIVEN THIS
IMPROVING LIFT/MOISTURE AHEAD OF THE DEEPENING NEW MEXICO LOW WILL
BEGIN INCREASING CLOUD COVER AND PRECIPITATION CHANCES EARLY
MONDAY NIGHT. WINDS BEHIND THIS COLD FRONT MAY ALSO BE AN ISSUE
LATE MONDAY AND EARLY MONDAY NIGHT AS A TIGHT SURFACE PRESSURE
GRADIENT IS EXPECTED TO DEVELOP ACROSS PORTIONS OF SOUTHWEST
KANSAS IN RESPONSE TO AN AREA OF LOW PRESSURE DEEPENING ALONG THIS
FRONTAL BOUNDARY NEAR THE OKLAHOMA PANHANDLE.
TUESDAY THROUGH EARLY WEDNESDAY STILL APPEARS SOMEWHAT UNCLEAR
GIVEN THE DISAGREEMENT ON TRACK OF THIS UPPER LOW AS IT MOVES EAST
INTO THE PANHANDLE OF TEXAS. SINCE MODELS DO NOT HANDLE THESE
SYSTEM WELL, ESPECIALLY BEYOND 72 HOURS WILL FOLLOW THE GENERAL
TREND OF THE ALLBLEND THROUGH MID WEEK. HAVE THEREFORE INCREASED
PRECIPITATION CHANCES ACROSS SOUTHWEST KANSAS AND GIVEN THE CLOUDS
AND PRECIPITATION EXPECTED HAVE ALSO LOWERED TEMPERATURES TUESDAY
AFTERNOON.
BY LATE WEDNESDAY THIS UPPER LOW MOVE EAST ACROSS THE PLAINS. AS
THIS SYSTEM MOVES EAST OF WESTERN KANSAS THE SKIES WILL CLEAR AS
AN UPPER LEVEL SHORTWAVE RIDGE STARTS TO BUILD INTO THE ROCKIES
FROM THE WEST. AS THE WESTERLY DOWNSLOPE FLOW IMPROVES LATE WEEK
TEMPERATURES WILL REBOUND OUT OF 60S AND BACK INTO THE
70S...POSSIBLY A FEW 80S BY LATE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1154 AM CDT SAT MAR 31 2012
A WEAK LOW PRESSURE TROUGH EXTENDED FROM A SURFACE CYCLONE IN
NORTHEAST NEBRASKA ACROSS NORTHWEST KANSAS INTO EASTERN COLORADO
LATE THIS MORNING. A DEEP UPPER LEVEL TROUGH NEAR 130W WILL DIG INTO
THE WESTERN UNITED STATES TONIGHT, AND PRESSURES WILL FALL QUICKLY
IN THE LEE OF THE ROCKIES. LOW LEVEL WINDS WILL BE SOUTH 10-20 KNOTS
TONIGHT AND INCREASE TO 20-25 KNOTS WITH HIGHER GUSTS SUNDAY. PATCHY
THIN CIRRIFORM CLOUDINESS AOA 250 WILL CONTINUE TO DRIFT ACROSS THE
CENTRAL PLAINS THROUGH SUNDAY. DRY AIR ALOFT OVER SHALLOW BOUNDARY
LAYER MOISTURE WILL FAVOR SUFFICIENT RADIATIONAL COOLING OF THE
MOIST LAYER TO RESULT IN SOME VISIBILITY RESTRICTION IN MIST,
ESPECIALLY AT THE HYS AND DDC TERMINAL SITES. VISIBILITIES MAY BE
RESTRICTED TO 4-5 MILES AT DDC AND HYS AROUND SUNRISE SUNDAY WITH
PATCHY DENSER FOG IN SOUTH CENTRAL KANSAS AROUND PRATT AND MEDICINE
LODGE. OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH SUNDAY.
&&
.FIRE WEATHER...
ISSUED AT 300 AM CDT SAT MAR 31 2012
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY AFTERNOON, AS
THE RELATIVE HUMIDITIES WILL NOT MEET RH CRITERIA. HAVE ADDRESSED THIS
CONCERN IN FWF. NEXT CONCERN IS CRITICAL FIRE WEATHER CONDITIONS EXPECTED
SUNDAY AFTERNOON. TEMPERATURES WILL BE VERY WARM AND WINDS WILL BE STRONGER
AS LEE CYCLOGENESIS STRENGTHENS ACROSS EASTERN COLORADO AND THE RELATED
PRESSURE GRADIENT INCREASES ACROSS THE REGION. THE FUEL STATUS PAGE
SHOWS THAT STEVENS AND MORTON COUNTY ARE A NO GO AS FUELS ARE NOT AT
THE APPROPRIATE LEVELS (NOTHING TO BURN?). THIS MAY HAVE TO BE ADDRESSED
BEFORE THE RFW IS ISSUED. OTHERWISE, AFTER COLLABORATION, IT WAS DECIDED
TO CONTINUE THE FIRE WEATHER WATCH FOR FAR WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 84 56 90 53 / 0 0 0 10
GCK 86 52 90 50 / 0 0 0 10
EHA 87 51 90 50 / 0 0 0 10
LBL 88 53 92 49 / 0 0 0 10
HYS 86 58 88 53 / 0 0 0 10
P28 83 60 88 58 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
UPDATE...RUTHI
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...RUTHI
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
940 AM CDT SAT MAR 31 2012
.UPDATE...
ISSUED AT 939 AM CDT SAT MAR 31 2012
A VERY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS WESTERN KANSAS
THROUGH THE MORNING HOURS. PRESSURES WILL FALL IN THE LEE OF THE
ROCKIES THIS AFTERNOON AS THE UPPER LEVEL TROUGH MOVING THROUGH
MANITOBA CONTINUES MOVING NORTHEAST AND THE STRONG UPPER LEVEL
TROUGH NEAR 130W REACHES THE WEST COAST. LOW LEVEL FLOW WILL
INCREASE FROM THE SOUTH AS THE ATMOSPHERE RESPONDS TO THE LEE
TROUGHING. TEMPERATURES THIS AFTERNOON MAY NOT BE QUITE AS WARM AS
ANTICIPATED DUE TO ANOMALOUSLY STRONG EVAPOTRANSPIRATION FROM
EARLY PLANT GROWTH AFTER THE HEAVY RAINFALL LAST WEEK. MINOR
DOWNWARD ADJUSTMENTS WERE MADE WHERE THE HEAVIEST RAIN FELL.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT SAT MAR 31 2012
.SYNOPSIS...
ISSUED AT 300 AM CDT SAT MAR 31 2012
THE 00Z 300 HPA SYNOPTIC MAP SHOWS A STRONG 140 KT JET TRAVERSING ACROSS
THE PACIFIC NORTHWEST. ACROSS THE PLAINS, 45 TO 65 KT NORTHWESTERLY
FLOW WAS OBSERVED IN THE WAKE OF A DEPARTING TROUGH AXIS LOCATED ACROSS
THE EASTERN PLAINS/MIDWEST. THE 500 HPA MAP SHOWED THAT VERY COLD AIR
OF -38 DEG C WAS OBSERVED ACROSS VANCOUVER ISLAND. IN THE LOWER LEVELS
(700 AND 850 HPA), A DRY AIRMASS WAS OVER THE PLAINS, PARTICULARLY ACROSS
THE NORTHERN PLAINS. SURFACE ANALYSIS FROM HPC SHOWED A LOW PRESSURE
SYSTEM WITH ASSOCIATED COLD AND WARM FRONTS MOVING ACROSS THE CANADIAN
PRAIRIES. HIGH PRESSURE WAS OVER THE CENTRAL AND SOUTHERN PLAINS. DEWPOINTS
CONTINUED TO BE IN THE MODERATE LEVELS (FOR END OF MARCH) WITH LOWER
TO MID 50S DEG F DEWPOINTS ACROSS SW AND SC KANSAS.
THIS MORNING:
THE MAIN FORECAST CONCERN FOR THIS MORNING IN TERMS OF SENSIBLE WEATHER
IS IF FOG WILL DEVELOP OR NOT. THE 01Z AND 02Z HRRR RUNS WERE VERY AGGRESSIVE
IN DEVELOPING DENSE FOG ACROSS THE SW/W KANSAS. THE 04Z HRRR RUN HAS
BACKED OFF ON THIS WITH A SMALLER AREA OF DENSE FOG MAINLY ACROSS HAMILTON
COUNTY. WHAT IS INTERESTING IS THAT EVEN THOUGH THE MODEL DEVELOPS THE
FOG, THE MODELS ALSO HAS DOWNSLOPE SSW AS THE SFC. THIS IS NOT CONDUCIVE
FOR DENSE FOG FORMATION ACROSS MY COUNTY WARNING AREA. VSREF ALSO SHOWED
SOME HIGHER PROBABILITIES FOR LOWER VIS ACROSS THE AREA. OTHER MODEL
GUIDANCE IS LESS SUGGESTIVE FOR FOG FORMATION. DESPITE THIS, OBSERVATIONS
ACROSS OKLAHOMA SHOW SOME PATCHY FOG DEVELOP THIS MORNING SO I HAVE
DECIDED TO MEET THE MODELS IN BETWEEN AND INSERT PATCHY FOG ACROSS MY
WESTERN COUNTIES. DEWPOINTS ARE CURRENTLY IN THE 50S DEG F WITH UPSLOPE
SE/S WINDS SO THE POTENTIAL CANNOT BE COMPLETELY DISMISSED ATTM.
TODAY:
500 HPA FLOW WILL BECOME MORE MORE WESTERLY THROUGH TODAY, WHICH WILL
STRENGTHEN LEE TROUGHING. AS A RESULT, A WARM AIR ADVECTION PATTERN
WILL BE IN PLACE TODAY WITH TEMPERATURES WARMING WELL ABOVE NORMAL.
MID 80S DEG F ARE EXPECTED FOR HIGHS TODAY, WHICH IS ABOUT 20 DEGREES
ABOVE NORMAL. THIS WARM MARCH WE HAVE BEEN EXPERIENCING WILL END ON
A VERY WARM NOTE FOR THE LAST DAY IN THE MONTH. TODAY WILL BE PRECIPITATION
FREE AS A FAIRLY FLAT UPPER LEVEL RIDGE PREVAILS ACROSS KANSAS. I HAVE
GONE WITH SLIGHTLY COOLER TEMPERATURES TODAY (MID 80S DEG F VERSUS UPPER
80S DEG F) AS RECENT VERIFICATION PER BOI VERIFY SHOWS THAT MODELS ARE
SUFFERING A BIT OF WARM BIAS. SOUTHERLY WINDS OF 15 TO 20 KT ARE EXPECTED
THIS AFTERNOON AS MIXING INCREASES TO ABOUT 750 HPA AND SOME STRONGER
WINDS MIX DOWN.
TONIGHT:
THE LEE SURFACE TROUGH AXIS WILL MOVE SLIGHTLY EASTWARD TONIGHT AND
FRAGMENT TOWARDS SUNDAY MORNING. THIS WILL KEEP SOUTHERLY WINDS IN THE
FORECAST OVERNIGHT. DEWPOINTS IN THE 30S DEG F WEST TO 50S DEG F EAST
WILL KEEP OVERNIGHT LOWS ON THE MILD SIDE, PARTICULARLY ACROSS SOUTH
CENTRAL KANSAS. HAVE AROUND 60 DEG F TOWARDS KP28 (MEDICINE LODGE, KS)
AND COOLER MID 40S NEAR K3K3 (SYRACUSE, KS).
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT MAR 31 2012
MODELS REMAINING VERY CONSISTENT WITH PREVIOUS RUNS AND KEEP
SUNDAY SUNNY AND WARM . 850MB 00Z MONDAY TEMPERATURES STILL
SUPPORT HIGHS AROUND 90 DEGREES FOR MUCH OF SOUTHWEST KANSAS.
THESE HIGHS FOR THE FIRST OF APRIL COULD EASILY SET NEW RECORD
HIGHS IN A FEW LOCATIONS. A FEW RECORDS FOR APRIL FIRST ARE....88
DEGREES AT DODGE CITY, 87 AT GARDEN CITY AND 93 DEGREES AT
MEDICINE LODGE.
IN ADDITION TO THIS UNSEASONABLY WARM TEMPERATURES...LOW DEW
POINTS WILL BE SPREADING INTO PORTIONS OF WESTERN KANSAS BEHIND A
DRYLINE. THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES
BOTTOMING OUT IN THE 10 TO 15 PERCENT RANGE IN SEVERAL LOCATIONS.
GIVEN THESE LOW RELATIVE HUMIDITIES ALONG WITH GUSTY SOUTHWEST
WINDS DEVELOPING DURING THE AFTERNOON HAVE DECIDED TO CONTINUE THE
FIRE WEATHER WATCH ACROSS MUCH OF WESTERN KANSAS.
FOR EARLY NEXT WEEK...OUR NEXT UPPER LEVEL STORM SYSTEM IS STILL
FORECAST BY THE GFS, ECMWF, AND CANADIAN TO CROSS THE FOUR CORNERS
REGION SUNDAY NIGHT. BY MONDAY THIS SYSTEM WILL BEGIN TO DEEPEN
ACROSS NEW MEXICO WHERE IT WILL MOVE VERY LITTLE THROUGH TUESDAY.
AHEAD OF THIS SYSTEM A SOUTHEAST FLOW WILL DRAW MORE HUMID AIR
NORTHWARD TOWARDS SOUTHWEST KANSAS ON MONDAY. IN ADDITION 850MB
WARM AIR ADVECTION AND 850-700 FRONTOGENESIS WILL BE ON THE
INCREASE LATE IN THE DAY ALONG AND JUST BEHIND A COLD FRONT WHICH
WILL BE CROSSING SOUTHERN KANSAS/NORTHERN OKLAHOMA. GIVEN THIS
IMPROVING LIFT/MOISTURE AHEAD OF THE DEEPENING NEW MEXICO LOW WILL
BEGIN INCREASING CLOUD COVER AND PRECIPITATION CHANCES EARLY
MONDAY NIGHT. WINDS BEHIND THIS COLD FRONT MAY ALSO BE AN ISSUE
LATE MONDAY AND EARLY MONDAY NIGHT AS A TIGHT SURFACE PRESSURE
GRADIENT IS EXPECTED TO DEVELOP ACROSS PORTIONS OF SOUTHWEST
KANSAS IN RESPONSE TO AN AREA OF LOW PRESSURE DEEPENING ALONG THIS
FRONTAL BOUNDARY NEAR THE OKLAHOMA PANHANDLE.
TUESDAY THROUGH EARLY WEDNESDAY STILL APPEARS SOMEWHAT UNCLEAR
GIVEN THE DISAGREEMENT ON TRACK OF THIS UPPER LOW AS IT MOVES EAST
INTO THE PANHANDLE OF TEXAS. SINCE MODELS DO NOT HANDLE THESE
SYSTEM WELL, ESPECIALLY BEYOND 72 HOURS WILL FOLLOW THE GENERAL
TREND OF THE ALLBLEND THROUGH MID WEEK. HAVE THEREFORE INCREASED
PRECIPITATION CHANCES ACROSS SOUTHWEST KANSAS AND GIVEN THE CLOUDS
AND PRECIPITATION EXPECTED HAVE ALSO LOWERED TEMPERATURES TUESDAY
AFTERNOON.
BY LATE WEDNESDAY THIS UPPER LOW MOVE EAST ACROSS THE PLAINS. AS
THIS SYSTEM MOVES EAST OF WESTERN KANSAS THE SKIES WILL CLEAR AS
AN UPPER LEVEL SHORTWAVE RIDGE STARTS TO BUILD INTO THE ROCKIES
FROM THE WEST. AS THE WESTERLY DOWNSLOPE FLOW IMPROVES LATE WEEK
TEMPERATURES WILL REBOUND OUT OF 60S AND BACK INTO THE
70S...POSSIBLY A FEW 80S BY LATE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 617 AM CDT SAT MAR 31 2012
VFR CIGS ARE EXPECTED THROUGH THE TAF PERIOD. A TROUGH OF LOW
PRESSURE AT THE SURFACE NEAR THE COLORADO BORDER WILL DEEPEN TODAY
WHICH WILL RESULT IN INCREASING SOUTH WINDS ACROSS WESTERN KANSAS.
WIND SPEEDS OF AROUND 15KTS CAN BE EXPECTED AFTER 18Z.
&&
.FIRE WEATHER...
ISSUED AT 300 AM CDT SAT MAR 31 2012
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY AFTERNOON, AS
THE RELATIVE HUMIDITIES WILL NOT MEET RH CRITERIA. HAVE ADDRESSED THIS
CONCERN IN FWF. NEXT CONCERN IS CRITICAL FIRE WEATHER CONDITIONS EXPECTED
SUNDAY AFTERNOON. TEMPERATURES WILL BE VERY WARM AND WINDS WILL BE STRONGER
AS LEE CYCLOGENESIS STRENGTHENS ACROSS EASTERN COLORADO AND THE RELATED
PRESSURE GRADIENT INCREASES ACROSS THE REGION. THE FUEL STATUS PAGE
SHOWS THAT STEVENS AND MORTON COUNTY ARE A NO GO AS FUELS ARE NOT AT
THE APPROPRIATE LEVELS (NOTHING TO BURN?). THIS MAY HAVE TO BE ADDRESSED
BEFORE THE RFW IS ISSUED. OTHERWISE, AFTER COLLABORATION, IT WAS DECIDED
TO CONTINUE THE FIRE WEATHER WATCH FOR FAR WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 85 56 90 53 / 0 0 0 10
GCK 86 52 90 50 / 0 0 0 10
EHA 85 51 90 50 / 0 0 0 10
LBL 86 53 92 49 / 0 0 0 10
HYS 86 58 88 53 / 0 0 0 10
P28 84 60 88 58 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
UPDATE...RUTHI
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
618 AM CDT SAT MAR 31 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT SAT MAR 31 2012
.SYNOPSIS...
ISSUED AT 300 AM CDT SAT MAR 31 2012
THE 00Z 300 HPA SYNOPTIC MAP SHOWS A STRONG 140 KT JET TRAVERSING ACROSS
THE PACIFIC NORTHWEST. ACROSS THE PLAINS, 45 TO 65 KT NORTHWESTERLY
FLOW WAS OBSERVED IN THE WAKE OF A DEPARTING TROUGH AXIS LOCATED ACROSS
THE EASTERN PLAINS/MIDWEST. THE 500 HPA MAP SHOWED THAT VERY COLD AIR
OF -38 DEG C WAS OBSERVED ACROSS VANCOUVER ISLAND. IN THE LOWER LEVELS
(700 AND 850 HPA), A DRY AIRMASS WAS OVER THE PLAINS, PARTICULARLY ACROSS
THE NORTHERN PLAINS. SURFACE ANALYSIS FROM HPC SHOWED A LOW PRESSURE
SYSTEM WITH ASSOCIATED COLD AND WARM FRONTS MOVING ACROSS THE CANADIAN
PRAIRIES. HIGH PRESSURE WAS OVER THE CENTRAL AND SOUTHERN PLAINS. DEWPOINTS
CONTINUED TO BE IN THE MODERATE LEVELS (FOR END OF MARCH) WITH LOWER
TO MID 50S DEG F DEWPOINTS ACROSS SW AND SC KANSAS.
THIS MORNING:
THE MAIN FORECAST CONCERN FOR THIS MORNING IN TERMS OF SENSIBLE WEATHER
IS IF FOG WILL DEVELOP OR NOT. THE 01Z AND 02Z HRRR RUNS WERE VERY AGGRESSIVE
IN DEVELOPING DENSE FOG ACROSS THE SW/W KANSAS. THE 04Z HRRR RUN HAS
BACKED OFF ON THIS WITH A SMALLER AREA OF DENSE FOG MAINLY ACROSS HAMILTON
COUNTY. WHAT IS INTERESTING IS THAT EVEN THOUGH THE MODEL DEVELOPS THE
FOG, THE MODELS ALSO HAS DOWNSLOPE SSW AS THE SFC. THIS IS NOT CONDUCIVE
FOR DENSE FOG FORMATION ACROSS MY COUNTY WARNING AREA. VSREF ALSO SHOWED
SOME HIGHER PROBABILITIES FOR LOWER VIS ACROSS THE AREA. OTHER MODEL
GUIDANCE IS LESS SUGGESTIVE FOR FOG FORMATION. DESPITE THIS, OBSERVATIONS
ACROSS OKLAHOMA SHOW SOME PATCHY FOG DEVELOP THIS MORNING SO I HAVE
DECIDED TO MEET THE MODELS IN BETWEEN AND INSERT PATCHY FOG ACROSS MY
WESTERN COUNTIES. DEWPOINTS ARE CURRENTLY IN THE 50S DEG F WITH UPSLOPE
SE/S WINDS SO THE POTENTIAL CANNOT BE COMPLETELY DISMISSED ATTM.
TODAY:
500 HPA FLOW WILL BECOME MORE MORE WESTERLY THROUGH TODAY, WHICH WILL
STRENGTHEN LEE TROUGHING. AS A RESULT, A WARM AIR ADVECTION PATTERN
WILL BE IN PLACE TODAY WITH TEMPERATURES WARMING WELL ABOVE NORMAL.
MID 80S DEG F ARE EXPECTED FOR HIGHS TODAY, WHICH IS ABOUT 20 DEGREES
ABOVE NORMAL. THIS WARM MARCH WE HAVE BEEN EXPERIENCING WILL END ON
A VERY WARM NOTE FOR THE LAST DAY IN THE MONTH. TODAY WILL BE PRECIPITATION
FREE AS A FAIRLY FLAT UPPER LEVEL RIDGE PREVAILS ACROSS KANSAS. I HAVE
GONE WITH SLIGHTLY COOLER TEMPERATURES TODAY (MID 80S DEG F VERSUS UPPER
80S DEG F) AS RECENT VERIFICATION PER BOI VERIFY SHOWS THAT MODELS ARE
SUFFERING A BIT OF WARM BIAS. SOUTHERLY WINDS OF 15 TO 20 KT ARE EXPECTED
THIS AFTERNOON AS MIXING INCREASES TO ABOUT 750 HPA AND SOME STRONGER
WINDS MIX DOWN.
TONIGHT:
THE LEE SURFACE TROUGH AXIS WILL MOVE SLIGHTLY EASTWARD TONIGHT AND
FRAGMENT TOWARDS SUNDAY MORNING. THIS WILL KEEP SOUTHERLY WINDS IN THE
FORECAST OVERNIGHT. DEWPOINTS IN THE 30S DEG F WEST TO 50S DEG F EAST
WILL KEEP OVERNIGHT LOWS ON THE MILD SIDE, PARTICULARLY ACROSS SOUTH
CENTRAL KANSAS. HAVE AROUND 60 DEG F TOWARDS KP28 (MEDICINE LODGE, KS)
AND COOLER MID 40S NEAR K3K3 (SYRACUSE, KS).
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT MAR 31 2012
MODELS REMAINING VERY CONSISTENT WITH PREVIOUS RUNS AND KEEP
SUNDAY SUNNY AND WARM . 850MB 00Z MONDAY TEMPERATURES STILL
SUPPORT HIGHS AROUND 90 DEGREES FOR MUCH OF SOUTHWEST KANSAS.
THESE HIGHS FOR THE FIRST OF APRIL COULD EASILY SET NEW RECORD
HIGHS IN A FEW LOCATIONS. A FEW RECORDS FOR APRIL FIRST ARE....88
DEGREES AT DODGE CITY, 87 AT GARDEN CITY AND 93 DEGREES AT
MEDICINE LODGE.
IN ADDITION TO THIS UNSEASONABLY WARM TEMPERATURES...LOW DEW
POINTS WILL BE SPREADING INTO PORTIONS OF WESTERN KANSAS BEHIND A
DRYLINE. THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES
BOTTOMING OUT IN THE 10 TO 15 PERCENT RANGE IN SEVERAL LOCATIONS.
GIVEN THESE LOW RELATIVE HUMIDITIES ALONG WITH GUSTY SOUTHWEST
WINDS DEVELOPING DURING THE AFTERNOON HAVE DECIDED TO CONTINUE THE
FIRE WEATHER WATCH ACROSS MUCH OF WESTERN KANSAS.
FOR EARLY NEXT WEEK...OUR NEXT UPPER LEVEL STORM SYSTEM IS STILL
FORECAST BY THE GFS, ECMWF, AND CANADIAN TO CROSS THE FOUR CORNERS
REGION SUNDAY NIGHT. BY MONDAY THIS SYSTEM WILL BEGIN TO DEEPEN
ACROSS NEW MEXICO WHERE IT WILL MOVE VERY LITTLE THROUGH TUESDAY.
AHEAD OF THIS SYSTEM A SOUTHEAST FLOW WILL DRAW MORE HUMID AIR
NORTHWARD TOWARDS SOUTHWEST KANSAS ON MONDAY. IN ADDITION 850MB
WARM AIR ADVECTION AND 850-700 FRONTOGENESIS WILL BE ON THE
INCREASE LATE IN THE DAY ALONG AND JUST BEHIND A COLD FRONT WHICH
WILL BE CROSSING SOUTHERN KANSAS/NORTHERN OKLAHOMA. GIVEN THIS
IMPROVING LIFT/MOISTURE AHEAD OF THE DEEPENING NEW MEXICO LOW WILL
BEGIN INCREASING CLOUD COVER AND PRECIPITATION CHANCES EARLY
MONDAY NIGHT. WINDS BEHIND THIS COLD FRONT MAY ALSO BE AN ISSUE
LATE MONDAY AND EARLY MONDAY NIGHT AS A TIGHT SURFACE PRESSURE
GRADIENT IS EXPECTED TO DEVELOP ACROSS PORTIONS OF SOUTHWEST
KANSAS IN RESPONSE TO AN AREA OF LOW PRESSURE DEEPENING ALONG THIS
FRONTAL BOUNDARY NEAR THE OKLAHOMA PANHANDLE.
TUESDAY THROUGH EARLY WEDNESDAY STILL APPEARS SOMEWHAT UNCLEAR
GIVEN THE DISAGREEMENT ON TRACK OF THIS UPPER LOW AS IT MOVES EAST
INTO THE PANHANDLE OF TEXAS. SINCE MODELS DO NOT HANDLE THESE
SYSTEM WELL, ESPECIALLY BEYOND 72 HOURS WILL FOLLOW THE GENERAL
TREND OF THE ALLBLEND THROUGH MID WEEK. HAVE THEREFORE INCREASED
PRECIPITATION CHANCES ACROSS SOUTHWEST KANSAS AND GIVEN THE CLOUDS
AND PRECIPITATION EXPECTED HAVE ALSO LOWERED TEMPERATURES TUESDAY
AFTERNOON.
BY LATE WEDNESDAY THIS UPPER LOW MOVE EAST ACROSS THE PLAINS. AS
THIS SYSTEM MOVES EAST OF WESTERN KANSAS THE SKIES WILL CLEAR AS
AN UPPER LEVEL SHORTWAVE RIDGE STARTS TO BUILD INTO THE ROCKIES
FROM THE WEST. AS THE WESTERLY DOWNSLOPE FLOW IMPROVES LATE WEEK
TEMPERATURES WILL REBOUND OUT OF 60S AND BACK INTO THE
70S...POSSIBLY A FEW 80S BY LATE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 617 AM CDT SAT MAR 31 2012
VFR CIGS ARE EXPECTED THROUGH THE TAF PERIOD. A TROUGH OF LOW
PRESSURE AT THE SURFACE NEAR THE COLORADO BORDER WILL DEEPEN TODAY
WHICH WILL RESULT IN INCREASING SOUTH WINDS ACROSS WESTERN KANSAS.
WIND SPEEDS OF AROUND 15KTS CAN BE EXPECTED AFTER 18Z.
&&
.FIRE WEATHER...
ISSUED AT 300 AM CDT SAT MAR 31 2012
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY AFTERNOON, AS
THE RELATIVE HUMIDITIES WILL NOT MEET RH CRITERIA. HAVE ADDRESSED THIS
CONCERN IN FWF. NEXT CONCERN IS CRITICAL FIRE WEATHER CONDITIONS EXPECTED
SUNDAY AFTERNOON. TEMPERATURES WILL BE VERY WARM AND WINDS WILL BE STRONGER
AS LEE CYCLOGENESIS STRENGTHENS ACROSS EASTERN COLORADO AND THE RELATED
PRESSURE GRADIENT INCREASES ACROSS THE REGION. THE FUEL STATUS PAGE
SHOWS THAT STEVENS AND MORTON COUNTY ARE A NO GO AS FUELS ARE NOT AT
THE APPROPRIATE LEVELS (NOTHING TO BURN?). THIS MAY HAVE TO BE ADDRESSED
BEFORE THE RFW IS ISSUED. OTHERWISE, AFTER COLLABORATION, IT WAS DECIDED
TO CONTINUE THE FIRE WEATHER WATCH FOR FAR WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 85 56 90 53 / 0 0 0 10
GCK 86 52 90 50 / 0 0 0 10
EHA 85 51 90 50 / 0 0 0 10
LBL 86 53 92 49 / 0 0 0 10
HYS 86 58 88 53 / 0 0 0 10
P28 84 60 88 58 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
324 AM CDT SAT MAR 31 2012
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT SAT MAR 31 2012
.SYNOPSIS...
ISSUED AT 300 AM CDT SAT MAR 31 2012
THE 00Z 300 HPA SYNOPTIC MAP SHOWS A STRONG 140 KT JET TRAVERSING ACROSS
THE PACIFIC NORTHWEST. ACROSS THE PLAINS, 45 TO 65 KT NORTHWESTERLY
FLOW WAS OBSERVED IN THE WAKE OF A DEPARTING TROUGH AXIS LOCATED ACROSS
THE EASTERN PLAINS/MIDWEST. THE 500 HPA MAP SHOWED THAT VERY COLD AIR
OF -38 DEG C WAS OBSERVED ACROSS VANCOUVER ISLAND. IN THE LOWER LEVELS
(700 AND 850 HPA), A DRY AIRMASS WAS OVER THE PLAINS, PARTICULARLY ACROSS
THE NORTHERN PLAINS. SURFACE ANALYSIS FROM HPC SHOWED A LOW PRESSURE
SYSTEM WITH ASSOCIATED COLD AND WARM FRONTS MOVING ACROSS THE CANADIAN
PRAIRIES. HIGH PRESSURE WAS OVER THE CENTRAL AND SOUTHERN PLAINS. DEWPOINTS
CONTINUED TO BE IN THE MODERATE LEVELS (FOR END OF MARCH) WITH LOWER
TO MID 50S DEG F DEWPOINTS ACROSS SW AND SC KANSAS.
THIS MORNING:
THE MAIN FORECAST CONCERN FOR THIS MORNING IN TERMS OF SENSIBLE WEATHER
IS IF FOG WILL DEVELOP OR NOT. THE 01Z AND 02Z HRRR RUNS WERE VERY AGGRESSIVE
IN DEVELOPING DENSE FOG ACROSS THE SW/W KANSAS. THE 04Z HRRR RUN HAS
BACKED OFF ON THIS WITH A SMALLER AREA OF DENSE FOG MAINLY ACROSS HAMILTON
COUNTY. WHAT IS INTERESTING IS THAT EVEN THOUGH THE MODEL DEVELOPS THE
FOG, THE MODELS ALSO HAS DOWNSLOPE SSW AS THE SFC. THIS IS NOT CONDUCIVE
FOR DENSE FOG FORMATION ACROSS MY COUNTY WARNING AREA. VSREF ALSO SHOWED
SOME HIGHER PROBABILITIES FOR LOWER VIS ACROSS THE AREA. OTHER MODEL
GUIDANCE IS LESS SUGGESTIVE FOR FOG FORMATION. DESPITE THIS, OBSERVATIONS
ACROSS OKLAHOMA SHOW SOME PATCHY FOG DEVELOP THIS MORNING SO I HAVE
DECIDED TO MEET THE MODELS IN BETWEEN AND INSERT PATCHY FOG ACROSS MY
WESTERN COUNTIES. DEWPOINTS ARE CURRENTLY IN THE 50S DEG F WITH UPSLOPE
SE/S WINDS SO THE POTENTIAL CANNOT BE COMPLETELY DISMISSED ATTM.
TODAY:
500 HPA FLOW WILL BECOME MORE MORE WESTERLY THROUGH TODAY, WHICH WILL
STRENGTHEN LEE TROUGHING. AS A RESULT, A WARM AIR ADVECTION PATTERN
WILL BE IN PLACE TODAY WITH TEMPERATURES WARMING WELL ABOVE NORMAL.
MID 80S DEG F ARE EXPECTED FOR HIGHS TODAY, WHICH IS ABOUT 20 DEGREES
ABOVE NORMAL. THIS WARM MARCH WE HAVE BEEN EXPERIENCING WILL END ON
A VERY WARM NOTE FOR THE LAST DAY IN THE MONTH. TODAY WILL BE PRECIPITATION
FREE AS A FAIRLY FLAT UPPER LEVEL RIDGE PREVAILS ACROSS KANSAS. I HAVE
GONE WITH SLIGHTLY COOLER TEMPERATURES TODAY (MID 80S DEG F VERSUS UPPER
80S DEG F) AS RECENT VERIFICATION PER BOI VERIFY SHOWS THAT MODELS ARE
SUFFERING A BIT OF WARM BIAS. SOUTHERLY WINDS OF 15 TO 20 KT ARE EXPECTED
THIS AFTERNOON AS MIXING INCREASES TO ABOUT 750 HPA AND SOME STRONGER
WINDS MIX DOWN.
TONIGHT:
THE LEE SURFACE TROUGH AXIS WILL MOVE SLIGHTLY EASTWARD TONIGHT AND
FRAGMENT TOWARDS SUNDAY MORNING. THIS WILL KEEP SOUTHERLY WINDS IN THE
FORECAST OVERNIGHT. DEWPOINTS IN THE 30S DEG F WEST TO 50S DEG F EAST
WILL KEEP OVERNIGHT LOWS ON THE MILD SIDE, PARTICULARLY ACROSS SOUTH
CENTRAL KANSAS. HAVE AROUND 60 DEG F TOWARDS KP28 (MEDICINE LODGE, KS)
AND COOLER MID 40S NEAR K3K3 (SYRACUSE, KS).
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 322 AM CDT SAT MAR 31 2012
MODELS REMAINING VERY CONSISTENT WITH PREVIOUS RUNS AND KEEP
SUNDAY SUNNY AND WARM . 850MB 00Z MONDAY TEMPERATURES STILL
SUPPORT HIGHS AROUND 90 DEGREES FOR MUCH OF SOUTHWEST KANSAS.
THESE HIGHS FOR THE FIRST OF APRIL COULD EASILY SET NEW RECORD
HIGHS IN A FEW LOCATIONS. A FEW RECORDS FOR APRIL FIRST ARE....88
DEGREES AT DODGE CITY, 87 AT GARDEN CITY AND 93 DEGREES AT
MEDICINE LODGE.
IN ADDITION TO THIS UNSEASONABLY WARM TEMPERATURES...LOW DEW
POINTS WILL BE SPREADING INTO PORTIONS OF WESTERN KANSAS BEHIND A
DRYLINE. THIS WILL RESULT IN AFTERNOON RELATIVE HUMIDITIES
BOTTOMING OUT IN THE 10 TO 15 PERCENT RANGE IN SEVERAL LOCATIONS.
GIVEN THESE LOW RELATIVE HUMIDITIES ALONG WITH GUSTY SOUTHWEST
WINDS DEVELOPING DURING THE AFTERNOON HAVE DECIDED TO CONTINUE THE
FIRE WEATHER WATCH ACROSS MUCH OF WESTERN KANSAS.
FOR EARLY NEXT WEEK...OUR NEXT UPPER LEVEL STORM SYSTEM IS STILL
FORECAST BY THE GFS, ECMWF, AND CANADIAN TO CROSS THE FOUR CORNERS
REGION SUNDAY NIGHT. BY MONDAY THIS SYSTEM WILL BEGIN TO DEEPEN
ACROSS NEW MEXICO WHERE IT WILL MOVE VERY LITTLE THROUGH TUESDAY.
AHEAD OF THIS SYSTEM A SOUTHEAST FLOW WILL DRAW MORE HUMID AIR
NORTHWARD TOWARDS SOUTHWEST KANSAS ON MONDAY. IN ADDITION 850MB
WARM AIR ADVECTION AND 850-700 FRONTOGENESIS WILL BE ON THE
INCREASE LATE IN THE DAY ALONG AND JUST BEHIND A COLD FRONT WHICH
WILL BE CROSSING SOUTHERN KANSAS/NORTHERN OKLAHOMA. GIVEN THIS
IMPROVING LIFT/MOISTURE AHEAD OF THE DEEPENING NEW MEXICO LOW WILL
BEGIN INCREASING CLOUD COVER AND PRECIPITATION CHANCES EARLY
MONDAY NIGHT. WINDS BEHIND THIS COLD FRONT MAY ALSO BE AN ISSUE
LATE MONDAY AND EARLY MONDAY NIGHT AS A TIGHT SURFACE PRESSURE
GRADIENT IS EXPECTED TO DEVELOP ACROSS PORTIONS OF SOUTHWEST
KANSAS IN RESPONSE TO AN AREA OF LOW PRESSURE DEEPENING ALONG THIS
FRONTAL BOUNDARY NEAR THE OKLAHOMA PANHANDLE.
TUESDAY THROUGH EARLY WEDNESDAY STILL APPEARS SOMEWHAT UNCLEAR
GIVEN THE DISAGREEMENT ON TRACK OF THIS UPPER LOW AS IT MOVES EAST
INTO THE PANHANDLE OF TEXAS. SINCE MODELS DO NOT HANDLE THESE
SYSTEM WELL, ESPECIALLY BEYOND 72 HOURS WILL FOLLOW THE GENERAL
TREND OF THE ALLBLEND THROUGH MID WEEK. HAVE THEREFORE INCREASED
PRECIPITATION CHANCES ACROSS SOUTHWEST KANSAS AND GIVEN THE CLOUDS
AND PRECIPITATION EXPECTED HAVE ALSO LOWERED TEMPERATURES TUESDAY
AFTERNOON.
BY LATE WEDNESDAY THIS UPPER LOW MOVE EAST ACROSS THE PLAINS. AS
THIS SYSTEM MOVES EAST OF WESTERN KANSAS THE SKIES WILL CLEAR AS
AN UPPER LEVEL SHORTWAVE RIDGE STARTS TO BUILD INTO THE ROCKIES
FROM THE WEST. AS THE WESTERLY DOWNSLOPE FLOW IMPROVES LATE WEEK
TEMPERATURES WILL REBOUND OUT OF 60S AND BACK INTO THE
70S...POSSIBLY A FEW 80S BY LATE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT MAR 31 2012
VFR CIGS ARE EXPECTED THROUGH THE TAF PERIOD. THE 01Z HRRR WAS
SUGGESTING THAT FOG WILL DEVELOP ACROSS FAR WEST KANSAS TOMORROW MORNING
WEST OF THE TERMINALS. WILL HAVE TO WATCH THIS TO SEE IF THE TREND/OBSERVATIONS
SHOW THIS THROUGH THE OVERNIGHT PERIOD AND IF THE FOG WILL EXTEND EAST.
OTHERWISE, WILL LEAVE FG OUT OF THE TAFS FOR NOW AS THIS IS THE ONLY
MODEL SUGGESTING THE POSSIBILITY OF LIFR/IFR CIGS. OTHERWISE, SOUTHERLY
WINDS WILL BECOME BREEZY (15-20 KT) THIS AFTERNOON IN ASSOCIATION WITH
AN EASTWARD EXTENSION OF A SURFACE TROUGH AXIS ACROSS WESTERN KS.
&&
.FIRE WEATHER...
ISSUED AT 300 AM CDT SAT MAR 31 2012
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY AFTERNOON, AS
THE RELATIVE HUMIDITIES WILL NOT MEET RH CRITERIA. HAVE ADDRESSED THIS
CONCERN IN FWF. NEXT CONCERN IS CRITICAL FIRE WEATHER CONDITIONS EXPECTED
SUNDAY AFTERNOON. TEMPERATURES WILL BE VERY WARM AND WINDS WILL BE STRONGER
AS LEE CYCLOGENESIS STRENGTHENS ACROSS EASTERN COLORADO AND THE RELATED
PRESSURE GRADIENT INCREASES ACROSS THE REGION. THE FUEL STATUS PAGE
SHOWS THAT STEVENS AND MORTON COUNTY ARE A NO GO AS FUELS ARE NOT AT
THE APPROPRIATE LEVELS (NOTHING TO BURN?). THIS MAY HAVE TO BE ADDRESSED
BEFORE THE RFW IS ISSUED. OTHERWISE, AFTER COLLABORATION, IT WAS DECIDED
TO CONTINUE THE FIRE WEATHER WATCH FOR FAR WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 85 56 90 53 / 0 0 0 10
GCK 86 52 90 50 / 0 0 0 10
EHA 85 51 90 50 / 0 0 0 10
LBL 86 53 92 49 / 0 0 0 10
HYS 86 58 88 53 / 0 0 0 10
P28 84 60 88 58 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....BURGERT
AVIATION...SUGDEN
FIRE WEATHER...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
300 AM CDT SAT MAR 31 2012
...UPDATED SYNOPSIS/SHORT TERM/FIRE WEATHER DISCUSSIONS...
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT SAT MAR 31 2012
.SYNOPSIS...
ISSUED AT 300 AM CDT SAT MAR 31 2012
THE 00Z 300 HPA SYNOPTIC MAP SHOWS A STRONG 140 KT JET TRAVERSING ACROSS
THE PACIFIC NORTHWEST. ACROSS THE PLAINS, 45 TO 65 KT NORTHWESTERLY
FLOW WAS OBSERVED IN THE WAKE OF A DEPARTING TROUGH AXIS LOCATED ACROSS
THE EASTERN PLAINS/MIDWEST. THE 500 HPA MAP SHOWED THAT VERY COLD AIR
OF -38 DEG C WAS OBSERVED ACROSS VANCOUVER ISLAND. IN THE LOWER LEVELS
(700 AND 850 HPA), A DRY AIRMASS WAS OVER THE PLAINS, PARTICULARLY ACROSS
THE NORTHERN PLAINS. SURFACE ANALYSIS FROM HPC SHOWED A LOW PRESSURE
SYSTEM WITH ASSOCIATED COLD AND WARM FRONTS MOVING ACROSS THE CANADIAN
PRAIRIES. HIGH PRESSURE WAS OVER THE CENTRAL AND SOUTHERN PLAINS. DEWPOINTS
CONTINUED TO BE IN THE MODERATE LEVELS (FOR END OF MARCH) WITH LOWER
TO MID 50S DEG F DEWPOINTS ACROSS SW AND SC KANSAS.
THIS MORNING:
THE MAIN FORECAST CONCERN FOR THIS MORNING IN TERMS OF SENSIBLE WEATHER
IS IF FOG WILL DEVELOP OR NOT. THE 01Z AND 02Z HRRR RUNS WERE VERY AGGRESSIVE
IN DEVELOPING DENSE FOG ACROSS THE SW/W KANSAS. THE 04Z HRRR RUN HAS
BACKED OFF ON THIS WITH A SMALLER AREA OF DENSE FOG MAINLY ACROSS HAMILTON
COUNTY. WHAT IS INTERESTING IS THAT EVEN THOUGH THE MODEL DEVELOPS THE
FOG, THE MODELS ALSO HAS DOWNSLOPE SSW AS THE SFC. THIS IS NOT CONDUCIVE
FOR DENSE FOG FORMATION ACROSS MY COUNTY WARNING AREA. VSREF ALSO SHOWED
SOME HIGHER PROBABILITIES FOR LOWER VIS ACROSS THE AREA. OTHER MODEL
GUIDANCE IS LESS SUGGESTIVE FOR FOG FORMATION. DESPITE THIS, OBSERVATIONS
ACROSS OKLAHOMA SHOW SOME PATCHY FOG DEVELOP THIS MORNING SO I HAVE
DECIDED TO MEET THE MODELS IN BETWEEN AND INSERT PATCHY FOG ACROSS MY
WESTERN COUNTIES. DEWPOINTS ARE CURRENTLY IN THE 50S DEG F WITH UPSLOPE
SE/S WINDS SO THE POTENTIAL CANNOT BE COMPLETELY DISMISSED ATTM.
TODAY:
500 HPA FLOW WILL BECOME MORE MORE WESTERLY THROUGH TODAY, WHICH WILL
STRENGTHEN LEE TROUGHING. AS A RESULT, A WARM AIR ADVECTION PATTERN
WILL BE IN PLACE TODAY WITH TEMPERATURES WARMING WELL ABOVE NORMAL.
MID 80S DEG F ARE EXPECTED FOR HIGHS TODAY, WHICH IS ABOUT 20 DEGREES
ABOVE NORMAL. THIS WARM MARCH WE HAVE BEEN EXPERIENCING WILL END ON
A VERY WARM NOTE FOR THE LAST DAY IN THE MONTH. TODAY WILL BE PRECIPITATION
FREE AS A FAIRLY FLAT UPPER LEVEL RIDGE PREVAILS ACROSS KANSAS. I HAVE
GONE WITH SLIGHTLY COOLER TEMPERATURES TODAY (MID 80S DEG F VERSUS UPPER
80S DEG F) AS RECENT VERIFICATION PER BOI VERIFY SHOWS THAT MODELS ARE
SUFFERING A BIT OF WARM BIAS. SOUTHERLY WINDS OF 15 TO 20 KT ARE EXPECTED
THIS AFTERNOON AS MIXING INCREASES TO ABOUT 750 HPA AND SOME STRONGER
WINDS MIX DOWN.
TONIGHT:
THE LEE SURFACE TROUGH AXIS WILL MOVE SLIGHTLY EASTWARD TONIGHT AND
FRAGMENT TOWARDS SUNDAY MORNING. THIS WILL KEEP SOUTHERLY WINDS IN THE
FORECAST OVERNIGHT. DEWPOINTS IN THE 30S DEG F WEST TO 50S DEG F EAST
WILL KEEP OVERNIGHT LOWS ON THE MILD SIDE, PARTICULARLY ACROSS SOUTH
CENTRAL KANSAS. HAVE AROUND 60 DEG F TOWARDS KP28 (MEDICINE LODGE, KS)
AND COOLER MID 40S NEAR K3K3 (SYRACUSE, KS).
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 216 PM CDT FRI MAR 30 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL RIDGE OF HIGH PRESSURE
TRANSITIONING EAST ACROSS THE CENTRAL PLAINS SUNDAY AND INTO THE
MISSISSIPPI RIVER VALLEY MONDAY RESULTING IN FAIRLY DRY CONDITIONS
ACROSS WESTERN KANSAS THROUGH SUNDAY NIGHT. MEANWHILE, AN UPPER
LEVEL TROUGH OF LOW PRESSURE IS EXPECTED TO PUSH EAST ACROSS THE
INTERMOUNTAIN WEST SUNDAY AND INTO THE WESTERN HIGH PLAINS EARLY
MONDAY BRINGING THE POSSIBILITY FOR PRECIP TO THE CENTRAL PLAINS
EARLY NEXT WEEK. ALTHOUGH STILL DIFFERING IN SOME DETAILS, THE GEM,
GFS, AND ECMWF ARE IN BETTER AGREEMENT SHOWING THE WAVE CLOSING OFF
AS IT SLIDES EAST-SOUTHEAST INTO THE SOUTH PLAINS OF OKLAHOMA, NORTH
TEXAS, AND PORTIONS OF SOUTHERN KANSAS. THE DETAILS AT ISSUE INCLUDE
THE TIMING OF AN ATTENDANT COLD FRONT EXPECTED TO PUSH THROUGH
WESTERN KANSAS SOMETIME MONDAY WITH A DRYLINE PASSAGE PRECLUDING THE
FRONT REDUCING THE AVAILABILITY OF LOW LEVEL MOISTURE AHEAD OF THE
UPPER LEVEL SYSTEM INITIALLY. THE ECMWF HAS FALLEN MORE IN LINE WITH
THE GFS SOLUTION BUT DIGS THE CLOSED OFF LOW A LITTLE FURTHER SOUTH
INTO TEXAS. THE GEM SOLUTION IS MUCH MORE IN LINE WITH THE GFS IN
HOW THIS MAY PLAY OUT SETTING UP THE CLOSED LOW SLIGHTLY MORE NORTH
BUT STILL JUST TO OUR SOUTH BY EARLY TUESDAY WITH H7 FRONTOGENETIC
BANDING INITIALLY DEVELOPING ACROSS PORTIONS OF SOUTHEASTERN
COLORADO AND SOUTHWESTERN KANSAS SOMETIME LATE MONDAY INTO EARLY
TUESDAY. ADDITIONALLY, TO SOME DEGREE ALL MODELS SHOW AN INCREASE IN
LOW TO MID LEVEL MOISTURE ACROSS WESTERN KANSAS LATE MONDAY INTO
TUESDAY AS THE UPPER LOW BEGINS TO DRAW MOISTURE NORTHWARD. THIS
COULD BRING A REASONABLE CHANCE FOR RAIN ACROSS PARTS OF KANSAS
DURING THIS GENERAL TIME FRAME. RIGHT NOW, 20 TO 30 POPS SEEMS
REASONABLE LATE MONDAY INTO TUESDAY CONSIDERING THE UNCERTAINTY OF
ALL THE FACTORS CONCERNED.
TEMPERATURES WILL BE WELL ABOVE NORMAL SUNDAY AS THE UPPER LEVEL
RIDGE MOVES EAST ACROSS THE CENTRAL PLAINS. A SURFACE LOW IS
EXPECTED TO DEVELOP ACROSS NORTHEASTERN COLORADO HELPING TO
MAINTAIN MORE OF A SOUTH TO SOUTHWEST LOW LEVEL FLOW ACROSS
WESTERN KANSAS. THIS WILL ENHANCE WARM AIR ADVECTION INTO THE
AREA WITH H85 TEMPERATURES RANGING FROM THE LOWER 20S(C) ACROSS
CENTRAL KANSAS TO JUST ABOVE 25C ALONG THE COLORADO BORDER. NAM AND
GFS MODEL SOUNDINGS ALSO SHOW STEEP LAPSE RATES DEVELOPING BY EARLY
TO MID AFTERNOON AS MAX HEATING IS APPROACHED. EXPECT HIGHS WELL UP
INTO THE 80S(F) WITH LOWER 90S(F) POSSIBLE IN SOME LOCATIONS SUNDAY
AFTERNOON. A SIGNIFICANT COOLING TREND IS EXPECTED TO BEGIN MONDAY
AS A COLD FRONT IS PROJECTED TO PUSH THROUGH WESTERN KANSAS SOMETIME
DURING THE DAY. THE TIMING OF THE FRONTAL PASSAGE IS STILL VERY MUCH
UNCERTAIN BUT CLOSER TO SEASONAL TEMPERATURES CAN BE EXPECTED MONDAY
WITH EVEN COOLER TEMPERATURES LIKELY TUESDAY AS COLDER AIR SURGES
SOUTH INTO WESTERN KANSAS. A GRADUAL WARMING TREND IS EXPECTED BY
THE END OF THE PERIOD AS UPPER LEVEL RIDGING IS PROJECTED TO
DEVELOP ACROSS THE WESTERN HIGH PLAINS BY MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT MAR 31 2012
VFR CIGS ARE EXPECTED THROUGH THE TAF PERIOD. THE 01Z HRRR WAS
SUGGESTING THAT FOG WILL DEVELOP ACROSS FAR WEST KANSAS TOMORROW MORNING
WEST OF THE TERMINALS. WILL HAVE TO WATCH THIS TO SEE IF THE TREND/OBSERVATIONS
SHOW THIS THROUGH THE OVERNIGHT PERIOD AND IF THE FOG WILL EXTEND EAST.
OTHERWISE, WILL LEAVE FG OUT OF THE TAFS FOR NOW AS THIS IS THE ONLY
MODEL SUGGESTING THE POSSIBILITY OF LIFR/IFR CIGS. OTHERWISE, SOUTHERLY
WINDS WILL BECOME BREEZY (15-20 KT) THIS AFTERNOON IN ASSOCIATION WITH
AN EASTWARD EXTENSION OF A SURFACE TROUGH AXIS ACROSS WESTERN KS.
&&
.FIRE WEATHER...
ISSUED AT 300 AM CDT SAT MAR 31 2012
MARGINAL FIRE WEATHER CONDITIONS ARE EXPECTED SATURDAY AFTERNOON, AS
THE RELATIVE HUMIDITIES WILL NOT MEET RH CRITERIA. HAVE ADDRESSED THIS
CONCERN IN FWF. NEXT CONCERN IS CRITICAL FIRE WEATHER CONDITIONS EXPECTED
SUNDAY AFTERNOON. TEMPERATURES WILL BE VERY WARM AND WINDS WILL BE STRONGER
AS LEE CYCLOGENESIS STRENGTHENS ACROSS EASTERN COLORADO AND THE RELATED
PRESSURE GRADIENT INCREASES ACROSS THE REGION. THE FUEL STATUS PAGE
SHOWS THAT STEVENS AND MORTON COUNTY ARE A NO GO AS FUELS ARE NOT AT
THE APPROPRIATE LEVELS (NOTHING TO BURN?). THIS MAY HAVE TO BE ADDRESSED
BEFORE THE RFW IS ISSUED. OTHERWISE, AFTER COLLABORATION, IT WAS DECIDED
TO CONTINUE THE FIRE WEATHER WATCH FOR FAR WESTERN KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 85 56 90 53 / 0 0 0 10
GCK 86 52 90 50 / 0 0 0 10
EHA 85 51 90 50 / 0 0 0 10
LBL 86 53 92 49 / 0 0 0 10
HYS 86 58 88 53 / 0 0 0 10
P28 84 60 88 58 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM....JJOHNSON
AVIATION...SUGDEN
FIRE WEATHER...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 AM CDT SAT MAR 31 2012
...UPDATE TO AVIATION FOR 06Z TAFS...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 212 PM CDT FRI MAR 30 2012
THE 12Z UPPER AIR ANALYSIS SHOWED A VERY WEAK SHORTWAVE TROUGH OVER
THE FRONT RANGE OF COLORADO EXTENDING SOUTHWARD INTO NEW MEXICO. AT
THE SURFACE...WEAK HIGH PRESSURE HAD SETTLED INTO WESTERN KANSAS
WHILE A WEAK LOW PRESSURE HAD MOVED SOUTH INTO NORTHWEST TEXAS.
MODEST LOW LEVEL MOISTURE WAS IN PLACE ACROSS SOUTH CENTRAL KANSAS
WHERE DEWPOINTS WERE IN THE MID 50S. DEWPOINTS WERE IN THE LOW 60S
ACROSS SOUTHERN OKLAHOMA INTO TEXAS.
THE SHORTWAVE HAS BEEN PROGRESSING STEADILY OVER THE CENTRAL HIGH
PLAINS THIS MORNING AND WILL BE MOVING INTO EASTERN KANSAS AND
OKLAHOMA BY LATE THIS AFTERNOON. MODEL SOUNDINGS ARE SHOWING SOME
MODERATE INSTABILITY OVER SOUTH CENTRAL KANSAS BUT ARE ALSO SHOWING
SOME WEAK BUT FAIRLY DEEP CAPPING IN THE 800-700 MB LAYER. WITH THE
WAVE MOVING PAST THE AREA BY PEAK HEATING, CONVECTIVE INHIBITION IN
THE CAPPING LAYER PLUS THE LACK OF ANY SURFACE CONVERGENCE...DO NOT
THINK WE WILL SEE ANY THUNDERSTORMS DEVELOPING ALONG THE OKLAHOMA
BORDER AND HAVE REMOVED THEM FROM THE FORECAST FOR THIS EVENING.
THE MODELS SHOW SURFACE DEWPOINTS INCREASING SOMEWHAT TONIGHT. HAVE
BUMPED UP OVERNIGHT LOWS A FEW DEGREES TO ACCOUNT FOR THIS. THERE
COULD BE SOME MIST DEVELOPING OVER PARTS OF SOUTHWEST KANSAS
OVERNIGHT BUT MODEL SOUNDINGS SHOW THE LOW LEVEL MOISTURE TO BE
PRETTY SHALLOW SO AM NOT EXPECTING ANY SIGNIFICANT FOG DEVELOPMENT.
ON SATURDAY AN UPPER LEVEL RIDGE WILL BE MOVING OVER THE CENTRAL
HIGH PLAINS. WE SHOULD SEE FAIRLY DEEP MIXING WHICH WILL ALLOW
TEMPERATURES TO CLIMB WELL UP INTO THE 80S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 216 PM CDT FRI MAR 30 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL RIDGE OF HIGH PRESSURE
TRANSITIONING EAST ACROSS THE CENTRAL PLAINS SUNDAY AND INTO THE
MISSISSIPPI RIVER VALLEY MONDAY RESULTING IN FAIRLY DRY CONDITIONS
ACROSS WESTERN KANSAS THROUGH SUNDAY NIGHT. MEANWHILE, AN UPPER
LEVEL TROUGH OF LOW PRESSURE IS EXPECTED TO PUSH EAST ACROSS THE
INTERMOUNTAIN WEST SUNDAY AND INTO THE WESTERN HIGH PLAINS EARLY
MONDAY BRINGING THE POSSIBILITY FOR PRECIP TO THE CENTRAL PLAINS
EARLY NEXT WEEK. ALTHOUGH STILL DIFFERING IN SOME DETAILS, THE GEM,
GFS, AND ECMWF ARE IN BETTER AGREEMENT SHOWING THE WAVE CLOSING OFF
AS IT SLIDES EAST-SOUTHEAST INTO THE SOUTH PLAINS OF OKLAHOMA, NORTH
TEXAS, AND PORTIONS OF SOUTHERN KANSAS. THE DETAILS AT ISSUE INCLUDE
THE TIMING OF AN ATTENDANT COLD FRONT EXPECTED TO PUSH THROUGH
WESTERN KANSAS SOMETIME MONDAY WITH A DRYLINE PASSAGE PRECLUDING THE
FRONT REDUCING THE AVAILABILITY OF LOW LEVEL MOISTURE AHEAD OF THE
UPPER LEVEL SYSTEM INITIALLY. THE ECMWF HAS FALLEN MORE IN LINE WITH
THE GFS SOLUTION BUT DIGS THE CLOSED OFF LOW A LITTLE FURTHER SOUTH
INTO TEXAS. THE GEM SOLUTION IS MUCH MORE IN LINE WITH THE GFS IN
HOW THIS MAY PLAY OUT SETTING UP THE CLOSED LOW SLIGHTLY MORE NORTH
BUT STILL JUST TO OUR SOUTH BY EARLY TUESDAY WITH H7 FRONTOGENETIC
BANDING INITIALLY DEVELOPING ACROSS PORTIONS OF SOUTHEASTERN
COLORADO AND SOUTHWESTERN KANSAS SOMETIME LATE MONDAY INTO EARLY
TUESDAY. ADDITIONALLY, TO SOME DEGREE ALL MODELS SHOW AN INCREASE IN
LOW TO MID LEVEL MOISTURE ACROSS WESTERN KANSAS LATE MONDAY INTO
TUESDAY AS THE UPPER LOW BEGINS TO DRAW MOISTURE NORTHWARD. THIS
COULD BRING A REASONABLE CHANCE FOR RAIN ACROSS PARTS OF KANSAS
DURING THIS GENERAL TIME FRAME. RIGHT NOW, 20 TO 30 POPS SEEMS
REASONABLE LATE MONDAY INTO TUESDAY CONSIDERING THE UNCERTAINTY OF
ALL THE FACTORS CONCERNED.
TEMPERATURES WILL BE WELL ABOVE NORMAL SUNDAY AS THE UPPER LEVEL
RIDGE MOVES EAST ACROSS THE CENTRAL PLAINS. A SURFACE LOW IS
EXPECTED TO DEVELOP ACROSS NORTHEASTERN COLORADO HELPING TO
MAINTAIN MORE OF A SOUTH TO SOUTHWEST LOW LEVEL FLOW ACROSS
WESTERN KANSAS. THIS WILL ENHANCE WARM AIR ADVECTION INTO THE
AREA WITH H85 TEMPERATURES RANGING FROM THE LOWER 20S(C) ACROSS
CENTRAL KANSAS TO JUST ABOVE 25C ALONG THE COLORADO BORDER. NAM AND
GFS MODEL SOUNDINGS ALSO SHOW STEEP LAPSE RATES DEVELOPING BY EARLY
TO MID AFTERNOON AS MAX HEATING IS APPROACHED. EXPECT HIGHS WELL UP
INTO THE 80S(F) WITH LOWER 90S(F) POSSIBLE IN SOME LOCATIONS SUNDAY
AFTERNOON. A SIGNIFICANT COOLING TREND IS EXPECTED TO BEGIN MONDAY
AS A COLD FRONT IS PROJECTED TO PUSH THROUGH WESTERN KANSAS SOMETIME
DURING THE DAY. THE TIMING OF THE FRONTAL PASSAGE IS STILL VERY MUCH
UNCERTAIN BUT CLOSER TO SEASONAL TEMPERATURES CAN BE EXPECTED MONDAY
WITH EVEN COOLER TEMPERATURES LIKELY TUESDAY AS COLDER AIR SURGES
SOUTH INTO WESTERN KANSAS. A GRADUAL WARMING TREND IS EXPECTED BY
THE END OF THE PERIOD AS UPPER LEVEL RIDGING IS PROJECTED TO
DEVELOP ACROSS THE WESTERN HIGH PLAINS BY MID TO LATE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT MAR 31 2012
VFR CIGS ARE EXPECTED THROUGH THE TAF PERIOD. THE 01Z HRRR WAS
SUGGESTING THAT FOG WILL DEVELOP ACROSS FAR WEST KANSAS TOMORROW MORNING
WEST OF THE TERMINALS. WILL HAVE TO WATCH THIS TO SEE IF THE TREND/OBSERVATIONS
SHOW THIS THROUGH THE OVERNIGHT PERIOD AND IF THE FOG WILL EXTEND EAST.
OTHERWISE, WILL LEAVE FG OUT OF THE TAFS FOR NOW AS THIS IS THE ONLY
MODEL SUGGESTING THE POSSIBILITY OF LIFR/IFR CIGS. OTHERWISE, SOUTHERLY
WINDS WILL BECOME BREEZY (15-20 KT) THIS AFTERNOON IN ASSOCIATION WITH
AN EASTWARD EXTENSION OF A SURFACE TROUGH AXIS ACROSS WESTERN KS.
&&
.FIRE WEATHER...
ISSUED AT 216 PM CDT FRI MAR 30 2012
CRITICAL FIRE WEATHER CONDITIONS ARE POSSIBLE SUNDAY AS AN UPPER
LEVEL RIDGE OF HIGH PRESSURE DRIFTS EAST ACROSS THE CENTRAL PLAINS.
AS MENTIONED EARLIER, A SURFACE LOW IS EXPECTED TO DEVELOP ACROSS
NORTHEASTERN COLORADO DURING THE DAY HELPING TO INFLUENCE A SOUTH TO
SOUTHWESTERLY LOW LEVEL FLOW ACROSS WESTERN KANSAS. NAM AND GFS
MODEL SOUNDINGS INDICATE A CAPPING INVERSION DISSOLVING BY EARLY TO
MID AFTERNOON ALLOWING STRONGER WINDS ALOFT TO MIX DOWN TO THE
SURFACE. ADDITIONALLY, A DRYLINE ATTENDANT TO THE SURFACE LOW IS
FORECAST TO EDGE EASTWARD ACROSS EXTREME WESTERN KANSAS RESULTING
IN VERY LOW RELATIVE HUMIDITY LEVELS. AS A RESULT, A FIRE WEATHER
WATCH WILL BE ISSUED FOR EXTREME SOUTHWESTERN KANSAS FOR SUNDAY
AFTERNOON INTO EARLY SUNDAY EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 85 57 90 / 0 0 0 0
GCK 49 86 51 90 / 0 0 0 0
EHA 48 86 47 90 / 0 0 0 0
LBL 51 87 52 92 / 0 0 0 0
HYS 52 87 58 88 / 0 0 0 0
P28 58 84 61 88 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR KSZ061-062-074-075-084-085.
&&
$$
SHORT TERM...GERARD
LONG TERM....JJOHNSON
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS WICHITA KS
1148 PM CDT FRI MAR 30 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
THE FOG POTENTIAL IS INCREASING FOR SE KS WHERE NEARLY CALM WINDS &
NARROWING TEMP/DWPT DEPRESSIONS RESIDE. SHORT-TERM SOUNDINGS (MORE SO
THE NAMBUFR) ARE INDICATING SUCH INCREASED POTENTIAL AS WELL. AS SUCH
ANTICIPATE VSBYS TO VARY FROM 1 1/2SM-3SM BR OVER KCNU FROM 10Z-13Z.
THE BR SHOULD DISSIPATE QUICKLY ~13Z AS INSOLATION INCREASES & S WINDS
SLOWLY ASSERT THEMSELVES. THE BR/FOG POTENTIAL SHOULD BE MUCH LWR OVER
CNTRL KS (ESPECIALLY WHEN COMPARED TO EARLY THIS MORNING!) WHERE WINDS
TAKE ON MORE SWLY COMPONENT & SLOWLY INCREASE. AS SUCH ALL 5 TERMINALS
TO REALIZE VFR STATUS THE REST OF 06Z TAF CYCLE.
&&
PREV DISCUSSION... /ISSUED 302 PM CDT FRI MAR 30 2012/
DISCUSSION...
FORECAST CHALLENGES...ISOLATED STORM CHANCES/PATCHY FOG POTENTIAL
TONIGHT...THEN PRECIP CHANCES/COOLING TREND EARLY NEXT WEEK.
TONIGHT-SUNDAY
DRIER LOW LEVELS IN WAKE OF SURFACE TROF AND NOCTURNAL
CONVECTION/OUTFLOW THAT EXITED SOUTHERN KANSAS LAST NIGHT HAS
STABILIZED AIRMASS ACROSS THE AREA. HOWEVER THE RUC AND TO A
LESSER EXTENT THE HRRR SUGGEST ISOLATED CONVECTION MAY DEVELOP
ACROSS THE FLINT HILLS OR SOUTHEAST KANSAS BY EARLY THIS
EVENING...WHERE MODEST INSTABILITY WILL RESIDE IN PRESENCE OF
WEAKENING INHIBITION. SO WILL KEEP ISOLATED TSRA MENTION FOR
AREAS SOUTHEAST OF GREATER WICHITA. IF CONVECTION DEVELOPS IT MAY
PERSIST INTO A PORTION OF THE OVERNIGHT HOURS...AIDED BY A WEAK
UPPER SHORTWAVE MOVING ACROSS THE LOWER MISSOURI VALLEY. LOCAL
PROCEDURES OFF THE SHORT TERM MODELS ARE SUGGESTIVE OF PATCHY FOG
AROUND DAWN ACROSS PORTIONS OF SOUTH CENTRAL/SOUTHEAST KANSAS.
UNSEASONABLY WARM AND MAINLY DRY WEATHER STILL LOOKS IN ORDER
FOR THIS WEEKEND AS A LARGE AMPLITUDE UPPER RIDGE DEVELOPS ACROSS
THE PLAINS. ANOTHER MORE SUBTLE UPPER SHORTWAVE WILL RIPPLE THRU
THE DEVELOPING RIDGE TO OUR NORTH AND EAST ON SATURDAY AFTERNOON
AND EVENING. THIS WILL KEEP MID LEVEL TEMPERATURES RELATIVELY COOL
PORTENDING TO WEAK CAPPING ACROSS EASTERN KANSAS...WHERE MODEST
DIURNAL INSTABILITY WILL EXIST TOWARD PEAK HEATING. WHILE AN
ISOLATED STORM CANNOT BE RULED OUT...WILL KEEP THE FORECAST DRY
FOR NOW. SUNDAY LOOKS TO BE THE WARMEST DAY...DARE WE SUGGEST
ALMOST HOT...ACROSS THE FORECAST AREA. MAXS SHOULD APPROACH
RECORDS IN SOME AREAS NEAR 90F...WITH GUSTY SOUTH WINDS.
MONDAY
A SIGNIFICANT UPPER TROF WILL MOVE ACROSS THE ROCKIES ON SUNDAY
NIGHT AND INTO THE HIGH PLAINS ON MONDAY. WILL CONTINUE TO CARRY
MODEST CHANCE POPS AHEAD OF THIS FEATURE AND ASSOCIATED SURFACE
FRONT...THOUGH SOMEWHAT SLOWER TIMING SUGGESTED A SLIGHT UP-TWEAK
TO MAXS WERE NEEDED AND A BIT SLOWER ONSET TO POPS.
TUESDAY-FRIDAY
THE MEDIUM RANGE MODELS ARE STILL GRAPPLING WITH HANDLING THE
EVENTUAL UPPER FLOW STREAM SEPARATION AND MOVEMENT OF THE CLOSED
LOW WHICH BECOMES CUT-OFF FROM THE STRONGER WESTERLIES. THIS LOW
WILL IMPACT KANSAS WEATHER AND PRECIP CHANCES THROUGH THE EARLY
AND MID-WEEK PERIODS...AND FOR NOW HAVE CONTINUED TO LEAN TOWARD
THE HPC GUIDANCE AND MORE PROGRESSIVE GFS.
DARMOFAL
FIRE WEATHER...
DESPITE UNSEASONBALY WARM TEMPERATURES AND INCREASING WINDS OVER
THE WEEKEND...THE GRASSLAND FIRE DANGER RISK IS EXPECTED TO BE
ONLY SLIGHTLY ELEVATED DUE TO THE EARLY SPRING GREEN-UP.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 58 84 61 87 / 0 10 10 0
HUTCHINSON 56 85 61 88 / 0 10 10 0
NEWTON 58 84 61 87 / 0 10 10 0
ELDORADO 59 84 61 87 / 0 10 10 0
WINFIELD-KWLD 59 84 62 87 / 10 10 10 0
RUSSELL 55 87 59 89 / 10 10 10 0
GREAT BEND 55 86 59 88 / 0 10 10 0
SALINA 57 87 61 89 / 10 10 10 0
MCPHERSON 56 85 61 88 / 0 10 10 0
COFFEYVILLE 59 85 62 88 / 20 10 10 0
CHANUTE 59 84 62 87 / 10 10 10 10
IOLA 59 84 62 87 / 10 10 10 10
PARSONS-KPPF 59 84 62 87 / 10 10 10 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
945 PM EDT SUN APR 1 2012
.UPDATE...
ISSUED AT 945 PM EDT SUN APR 1 2012
A NARROW LINE OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED NORTH OF A
LINE FROM INDIANAPOLIS TO DAYTON OVER THE PAST FEW HOURS. THIS IS
MOST LIKELY TH LINE OF SHOWERS AND STORMS THAT THE HRRR HAS BEEN
PICKING UP ON. THUS...THIS IS THE LINE THAT IS MOST LIKELY TO AFFECT
US TONIGHT. BASED ON THE MOVEMENT AND SPEED OF THIS LINE...IT WILL
NOT MAKE IT INTO THE BLUEGRASS UNTIL 3 OR 4 AM AT THE EARLIEST. WITH
THE SURFACE ALREADY DECOUPLING UNDER CLEAR SKIES...WIND THREAT FROM
ANY OF THESE STORMS APPEARS VERY MARGINAL AT BEST. ANY THREAT WILL
LIKELY COME FROM LARGE HAIL...AND EVEN THIS IS QUESTIONABLE.
THUS...SEVERE THREAT LOOKS MUCH MORE MARGINAL NOW...BUT STILL CANNOT
BE RULED OUT. HAVE TRIMMED BACK POPS ACROSS THE SOUTHWEST A BIT MORE
AS IT APPEARS MOST LIKELY TO AFFECT THE NORTHEASTERN TWO THIRDS OF
THE FORECAST AREA. KEPT SOME POPS AROUND DURING THE MORNING ACROSS
THE SOUTHEAST AS WE COULD HAVE SOME BACKBUILDING ALONG THIS LINE OF
SHOWERS AND STORMS. OTHERWISE...THE ACTIVITY SHOULD COME TO AN END
THERE BY MIDDAY...WITH THE AFTERNOON TURNING DRIER.
UPDATE ISSUED AT 738 PM EDT SUN APR 1 2012
AFTER A CLOUDY DAY WITH SOME RAIN SHOWERS...SKIES HAVE CLEARED OUT
ACROSS EASTERN KENTUCKY THIS EVENING. IN ACCORDANCE...HAVE ALTERED
THE FORECAST TO REFLECT MORE CLEAR SKIES OVER THE NEXT SEVERAL HOURS.
HOWEVER...SHOWERS AND A FEW STORMS ARE ALREADY BEGINNING TO DEVELOP
TO THE NORTH FROM JUST NORTHWEST OF INDIANAPOLIS TO JUST NORTH OF
WILMINGTON OHIO. THE HRRR SHOWS THIS ACTIVITY PUSHING SOUTH INTO OUR
NORTHERN AREAS CLOSE TO MIDNIGHT. IT LOOKS INCREASINGLY LIKELY ONLY
THE EASTERN COUNTIES WILL STAND THE BEST CHANCE OF RAIN TONIGHT...SO
HAVE REMOVED POPS FROM OUR SOUTHWEST ZONES. OTHERWISE...MADE SOME
MINOR ADJUSTMENT TO TEMPERATURES AND WINDS.
UPDATE ISSUED AT 526 PM EDT SUN APR 1 2012
LAST OF THE MCS IS FINALLY DEPARTING OFF TO OUR SOUTHEAST...WITH
SKIES QUICKLY CLEARING ACROSS THE AREA THIS EVENING. THIS SHOULD
ALLOW FOR MOST PLACES TO REACH THEIR HIGH FOR THE DAY OVER THE NEXT
HOUR OR TWO AS TEMPERATURES QUICKLY SHOOT UP WITH THE SUNSHINE. WITH
STABLE AREA ENTRENCHED ACROSS EASTERN KENTUCKY STRETCHING NORTH INTO
SOUTHERN OHIO...ANY DEVELOPING MCS WILL BE AT LEAST 3 TO 6 HOURS
BEFORE IT IMPACTS OUR NECK OF THE WOODS. WITH THIS IN MIND...HAVE
GONE AHEAD AND DELAYED THE BETTER PRECIPITATION CHANCES UNTIL AFTER
04Z (MIDNIGHT). THE HRRR SEEMS TO HAVE THE BEST TIMING AND HANDLING
ON THE SITUATION WITH ALL OTHER MODELS TO AGGRESSIVE ON REDEVELOPING
ACTIVITY IN THE STABLE BOUNDARY LAYER OVER THE NEXT FEW HOURS. NO
INDICATION THIS WILL HAPPEN AS CLOUDS ARE FEW AND FAR BETWEEN.
THUS...THE HRRR INDICATION OF LATER CONVECTION SEEMS LIKE THE WAY TO
GO UNTIL SOMETHING SHOWS ME OTHERWISE. STILL GOING TO BE MAINLY A
HAIL THREAT...ESPECIALLY GIVEN MOST OF THE ACTIVITY SHOULD BE
ELEVATED. WILL CONTINUE TO MONITOR FOR ADDITIONAL UPDATES AS EVENTS
UNFOLD OVER THE NEXT 3 TO 6 HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 359 PM EDT SUN APR 1 2012
THE LEFTOVER MCS IS FINALLY MAKING AN EXIT ACROSS THE AREA...WITH
THE BACK EDGE LIKELY TO EXIT BETWEEN 4 AND 5 PM. HIGHS HAVE REALLY
BEEN HAMPERED BY THE CLOUD COVER...BUT DO EXPECT A LATE IN THE DAY
PUSH...WITH SOME LOW TO MID 70S FOUND WEST OF I-75...WHILE MOST
OTHERS RANGE FROM THE MIDDLE 60S TO AROUND 70 DEGREES.
THE MODELS CONTINUE TO PLAY UP ANOTHER THUNDERSTORM COMPLEX TO
DEVELOP ACROSS THE UPPER OHIO BASIN LATER THIS EVENING IN RESPONSE TO
A DIGGING SHORT WAVE TROUGH WHICH WILL NOSE IN FROM THE SAINT
LAWRENCE RIVER VALLEY OVERNIGHT. THE MODEL TIMING OF THIS ACTIVITY IF
IT DOES HAPPEN...SEEMS A BIT FAST...AS THERE IS NOTHING POPPING YET
IN NORTHERN OHIO. WILL CONTINUE TO ALLOW FOR SOME GOOD CHANCE POPS
LATER TONIGHT FOR THE NORTHEAST HALF OF THE AREA...SCALING BACK
QUICKLY TO SLIGHT CHANCE TO THE SOUTHWEST.
AS FOR THE SEVERE THREAT...HAVE EVEN LESS CONFIDENCE IN THIS...AS WE
HAVE BEEN STABILIZED BY THE STORMS THAT TOOK PLACE THIS AFTERNOON.
WILL HAVE TO WAIT AND SEE HOW THE ATMOSPHERE RECOVERS TONIGHT...WITH
AT LEAST LIGHT SOUTHWEST WINDS ADVECTING SOME LOW LEVEL
MOISTURE...WHICH MAY RECHARGE US SOMEWHAT.
THIS COMPLEX...WILL HELP DRAG A BACKDOOR COOL FRONT THROUGH THE AREA
DURING THE DAY TOMORROW. BESIDES SOME LEFTOVER CONVECTION IN THE
MORNING...DO NOT EXPECT ANY RE-FIRING LATER IN THE DAY...WITH THE
MODEL SOUNDINGS SHOWING SOME DECENT CAPPING. THE FRONT WILL THEN MOVE
BACK TO THE NORTHEAST MONDAY NIGHT AS A WARM FRONT...PERHAPS KICKING
OFF SOME ISOLATED CONVECTION AS THIS OCCURS.
AS FOR TEMPERATURES...ABOVE NORMAL READINGS WILL CONTINUE...ALTHOUGH
READINGS HAVE COME IN A BIT COOLER FOR MONDAY WITH A LITTLE MORE
COOLER AND DRIER AIR INTRUSION...SO 70S WILL MOST LIKELY BE THE RULE
FOR MOST LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 359 PM EDT SUN APR 1 2012
A RATHER COMPLEX AND SOMEWHAT PROGRESSIVE PATTERN IS ANTICIPATED
DURING THE LONG TERM PERIOD. MOST OF THE TIME THE MAIN BAND OF
WESTERLIES ARE EXPECTED TO RESIDE TO OUR WEST...NORTH OR NORTHEAST
WITH UPPER LEVEL RIDGING POSSIBLY DOMINATING DURING TWO DISTINCT
PERIODS...WITH THE HIGHEST CHANCE OF THIS LATE IN THE PERIOD.
OVERALL...MODELS ARE IN REASONABLY GOOD AGREEMENT WITH THE PATTERN
WITH SOME DIFFERENCES LATER IN THE PERIOD AND SOME TIMING
DIFFERENCES FROM INDIVIDUAL MODEL RUN TO MODEL RUN.
EARLY ON...A WARM FRONT WILL BE MOVING NORTHEAST AND POSSIBLY EXIT
NORTHEAST OF THE AREA BY TUESDAY AFTERNOON OR EVENING. MODELS
GENERALLY DEVELOP PRECIP ONLY OVER THE EASTERN HALF OF THE CWA EARLY
IN THE PERIOD...WITH A POSSIBLE PERIOD OF SHORTWAVE RIDGING/DRY
SLOTTING OCCURRING BEFORE A COLD FRONT APPROACHES LATE IN THE DAY OR
TUE NIGHT.
THIS COLD FRONT WILL DROP SLOWLY SOUTH FROM TUE NIGHT INTO
WED...WITH THE MODEL CONSENSUS TAKING THE BOUNDARY SOUTH OF THE CWA
BY WED EVENING. HOWEVER...THE BOUNDARY SHOULD THEN STALL FOR A
TIME...THOUGH THE MODELS VARY IN HOW LONG DUE TO DIFFERENCES IN
HANDLING AN UPPER LOW THAT WILL MEANDER SOUTH OF A NORTHERN
PLAINS/NORTHERN GREAT LAKES RIDGE FROM THE SOUTHERN ROCKIES ACROSS
THE PLAINS AND MS VALLEY AND ON INTO THE EASTERN CONUS...POSSIBLY
ACROSS THE TN VALLEY AND INTO THE SOUTHERN APPALACHIANS AND THEN OFF
THE EASTERN SEABOARD. THIS UPPER LOW IS EXPECTED TO FOLLOW THIS
MEANDERING PATH FROM THE START OF THE PERIOD ON TUE THROUGH FRI.
AS MENTIONED BY THE PREVIOUS FORECASTER....BUT FRI IT SHOULD FINALLY
GET PICKED UP BY A TROUGH TO ITS NORTHEAST AND THIS SHOULD THEN TAKE
IT OUT TO SEA. THEREAFTER...THE MODEL CONSENSUS IS FOR THE UPPER
LEVEL RIDGE TO BUILD IN AND DOMINATE THAT LAST TWO TO TWO AND A HALF
DAYS OF THE PERIOD.
AS FOR POPS...WENT WITH SLIGHT CHANCE TO CHANCE POPS EARLY ON TUE
WITH THE WARM FRONT AND THEN INCREASED POPS LATE ON TUE INTO TUE
EVENING IN ADVANCE OF THE APPROACHING COLD FRONT AND SHORTWAVE THAT
THE MODEL CONSENSUS TAKES ACROSS THE OH VALLEY REGION OR THE CWA ON
TUE NIGHT. THE BOUNDARY SHOULD CONTINUE SLIPPING SOUTH ON WED AND
CONTINUED CHANCE POPS DURING WED...BUT GRADUALLY LOWERED POPS IN THE
NORTH FARTHER AWAY FROM THE BOUNDARY. A SFC LOW MAY DEVELOP ALONG
THE BOUNDARY AS THE UPPER LOW APPROACHES AROUND MIDWEEK AND SLOW THE
SOUTHWARD PROGRESS OF THE FRONT AND HOLD IN CHANCES FOR ISOLATED TO
SCATTERED CONVECTION AS THE SFC LOW AND UPPER SYSTEM PROBABLY TRACK
JUST TO OUR SOUTH ACROSS THE TN VALLEYS. ONCE THE UPPER SYSTEM
TRACKS EAST...PRECIP CHANCES WILL DIMINISH LATE THU NIGHT OR FRI.
FOR NOW THE END OF THE FORECAST IS EXPECTED TO BE DRY...WITH UPPER
LEVEL RIDGING DOMINATING. WITH THIS RIDGE...OPTED TO FAVOR THE ECMWF
RUNS.
TEMPERATURES SHOULD BE WARMEST AND MOST ABOVE NORMAL ON TUESDAY AND THEN
MORE MODEST DEPARTURES OF ABOUT 5 DEGREES ABOVE NORMAL AT THE END OF
THE PERIOD. OVERNIGHT LOWS SHOULD AVERAGE AT LEAST 5 DEGREES ABOVE
NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 738 PM EDT SUN APR 1 2012
VFR CONDITIONS WILL START THE EVENING HOURS. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO CREEP SOUTH INTO NORTHEAST KENTUCKY
OVERNIGHT. RIGHT NOW...IT DOES APPEAR THAT THE BEST THREAT WILL BE
ALONG AND EAST OF A LINE FROM MOREHEAD...TO JACKSON...TO HARLAN.
OTHERWISE...SOME PATCHY VALLEY FOG IS EXPECTED WITH THE CURRENT CLEAR
SKIES. WILL HOLD THINGS AT MVFR RIGHT NOW WITH PERHAPS BETTER
SOUTHERLY WINDS KEEPING THE FOG AT BAY. THIS COULD CHANGE HOWEVER.
OTHERWISE...THE SHOWERS...STORMS...AND ANY FOG WILL DEPART TOMORROW
MORNING...LEAVING BEHIND VFR CONDITIONS FOR THE DAYLIGHT HOURS.
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GEOGERIAN
LONG TERM....JP
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
739 PM EDT SUN APR 1 2012
.UPDATE...
ISSUED AT 738 PM EDT SUN APR 1 2012
AFTER A CLOUDY DAY WITH SOME RAIN SHOWERS...SKIES HAVE CLEARED OUT
ACROSS EASTERN KENTUCKY THIS EVENING. IN ACCORDANCE...HAVE ALTERED
THE FORECAST TO REFLECT MORE CLEAR SKIES OVER THE NEXT SEVERAL HOURS.
HOWEVER...SHOWERS AND A FEW STORMS ARE ALREADY BEGINNING TO DEVELOP
TO THE NORTH FROM JUST NORTHWEST OF INDIANAPOLIS TO JUST NORTH OF
WILMINGTON OHIO. THE HRRR SHOWS THIS ACTIVITY PUSHING SOUTH INTO OUR
NORTHERN AREAS CLOSE TO MIDNIGHT. IT LOOKS INCREASINGLY LIKELY ONLY
THE EASTERN COUNTIES WILL STAND THE BEST CHANCE OF RAIN TONIGHT...SO
HAVE REMOVED POPS FROM OUR SOUTHWEST ZONES. OTHERWISE...MADE SOME
MINOR ADJUSTMENT TO TEMPERATURES AND WINDS.
UPDATE ISSUED AT 526 PM EDT SUN APR 1 2012
LAST OF THE MCS IS FINALLY DEPARTING OFF TO OUR SOUTHEAST...WITH
SKIES QUICKLY CLEARING ACROSS THE AREA THIS EVENING. THIS SHOULD
ALLOW FOR MOST PLACES TO REACH THEIR HIGH FOR THE DAY OVER THE NEXT
HOUR OR TWO AS TEMPERATURES QUICKLY SHOOT UP WITH THE SUNSHINE. WITH
STABLE AREA ENTRENCHED ACROSS EASTERN KENTUCKY STRETCHING NORTH INTO
SOUTHERN OHIO...ANY DEVELOPING MCS WILL BE AT LEAST 3 TO 6 HOURS
BEFORE IT IMPACTS OUR NECK OF THE WOODS. WITH THIS IN MIND...HAVE
GONE AHEAD AND DELAYED THE BETTER PRECIPITATION CHANCES UNTIL AFTER
04Z (MIDNIGHT). THE HRRR SEEMS TO HAVE THE BEST TIMING AND HANDLING
ON THE SITUATION WITH ALL OTHER MODELS TO AGGRESSIVE ON REDEVELOPING
ACTIVITY IN THE STABLE BOUNDARY LAYER OVER THE NEXT FEW HOURS. NO
INDICATION THIS WILL HAPPEN AS CLOUDS ARE FEW AND FAR BETWEEN.
THUS...THE HRRR INDICATION OF LATER CONVECTION SEEMS LIKE THE WAY TO
GO UNTIL SOMETHING SHOWS ME OTHERWISE. STILL GOING TO BE MAINLY A
HAIL THREAT...ESPECIALLY GIVEN MOST OF THE ACTIVITY SHOULD BE
ELEVATED. WILL CONTINUE TO MONITOR FOR ADDITIONAL UPDATES AS EVENTS
UNFOLD OVER THE NEXT 3 TO 6 HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 359 PM EDT SUN APR 1 2012
THE LEFTOVER MCS IS FINALLY MAKING AN EXIT ACROSS THE AREA...WITH
THE BACK EDGE LIKELY TO EXIT BETWEEN 4 AND 5 PM. HIGHS HAVE REALLY
BEEN HAMPERED BY THE CLOUD COVER...BUT DO EXPECT A LATE IN THE DAY
PUSH...WITH SOME LOW TO MID 70S FOUND WEST OF I-75...WHILE MOST
OTHERS RANGE FROM THE MIDDLE 60S TO AROUND 70 DEGREES.
THE MODELS CONTINUE TO PLAY UP ANOTHER THUNDERSTORM COMPLEX TO
DEVELOP ACROSS THE UPPER OHIO BASIN LATER THIS EVENING IN RESPONSE TO
A DIGGING SHORT WAVE TROUGH WHICH WILL NOSE IN FROM THE SAINT
LAWRENCE RIVER VALLEY OVERNIGHT. THE MODEL TIMING OF THIS ACTIVITY IF
IT DOES HAPPEN...SEEMS A BIT FAST...AS THERE IS NOTHING POPPING YET
IN NORTHERN OHIO. WILL CONTINUE TO ALLOW FOR SOME GOOD CHANCE POPS
LATER TONIGHT FOR THE NORTHEAST HALF OF THE AREA...SCALING BACK
QUICKLY TO SLIGHT CHANCE TO THE SOUTHWEST.
AS FOR THE SEVERE THREAT...HAVE EVEN LESS CONFIDENCE IN THIS...AS WE
HAVE BEEN STABILIZED BY THE STORMS THAT TOOK PLACE THIS AFTERNOON.
WILL HAVE TO WAIT AND SEE HOW THE ATMOSPHERE RECOVERS TONIGHT...WITH
AT LEAST LIGHT SOUTHWEST WINDS ADVECTING SOME LOW LEVEL
MOISTURE...WHICH MAY RECHARGE US SOMEWHAT.
THIS COMPLEX...WILL HELP DRAG A BACKDOOR COOL FRONT THROUGH THE AREA
DURING THE DAY TOMORROW. BESIDES SOME LEFTOVER CONVECTION IN THE
MORNING...DO NOT EXPECT ANY RE-FIRING LATER IN THE DAY...WITH THE
MODEL SOUNDINGS SHOWING SOME DECENT CAPPING. THE FRONT WILL THEN MOVE
BACK TO THE NORTHEAST MONDAY NIGHT AS A WARM FRONT...PERHAPS KICKING
OFF SOME ISOLATED CONVECTION AS THIS OCCURS.
AS FOR TEMPERATURES...ABOVE NORMAL READINGS WILL CONTINUE...ALTHOUGH
READINGS HAVE COME IN A BIT COOLER FOR MONDAY WITH A LITTLE MORE
COOLER AND DRIER AIR INTRUSION...SO 70S WILL MOST LIKELY BE THE RULE
FOR MOST LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 359 PM EDT SUN APR 1 2012
A RATHER COMPLEX AND SOMEWHAT PROGRESSIVE PATTERN IS ANTICIPATED
DURING THE LONG TERM PERIOD. MOST OF THE TIME THE MAIN BAND OF
WESTERLIES ARE EXPECTED TO RESIDE TO OUR WEST...NORTH OR NORTHEAST
WITH UPPER LEVEL RIDGING POSSIBLY DOMINATING DURING TWO DISTINCT
PERIODS...WITH THE HIGHEST CHANCE OF THIS LATE IN THE PERIOD.
OVERALL...MODELS ARE IN REASONABLY GOOD AGREEMENT WITH THE PATTERN
WITH SOME DIFFERENCES LATER IN THE PERIOD AND SOME TIMING
DIFFERENCES FROM INDIVIDUAL MODEL RUN TO MODEL RUN.
EARLY ON...A WARM FRONT WILL BE MOVING NORTHEAST AND POSSIBLY EXIT
NORTHEAST OF THE AREA BY TUESDAY AFTERNOON OR EVENING. MODELS
GENERALLY DEVELOP PRECIP ONLY OVER THE EASTERN HALF OF THE CWA EARLY
IN THE PERIOD...WITH A POSSIBLE PERIOD OF SHORTWAVE RIDGING/DRY
SLOTTING OCCURRING BEFORE A COLD FRONT APPROACHES LATE IN THE DAY OR
TUE NIGHT.
THIS COLD FRONT WILL DROP SLOWLY SOUTH FROM TUE NIGHT INTO
WED...WITH THE MODEL CONSENSUS TAKING THE BOUNDARY SOUTH OF THE CWA
BY WED EVENING. HOWEVER...THE BOUNDARY SHOULD THEN STALL FOR A
TIME...THOUGH THE MODELS VARY IN HOW LONG DUE TO DIFFERENCES IN
HANDLING AN UPPER LOW THAT WILL MEANDER SOUTH OF A NORTHERN
PLAINS/NORTHERN GREAT LAKES RIDGE FROM THE SOUTHERN ROCKIES ACROSS
THE PLAINS AND MS VALLEY AND ON INTO THE EASTERN CONUS...POSSIBLY
ACROSS THE TN VALLEY AND INTO THE SOUTHERN APPALACHIANS AND THEN OFF
THE EASTERN SEABOARD. THIS UPPER LOW IS EXPECTED TO FOLLOW THIS
MEANDERING PATH FROM THE START OF THE PERIOD ON TUE THROUGH FRI.
AS MENTIONED BY THE PREVIOUS FORECASTER....BUT FRI IT SHOULD FINALLY
GET PICKED UP BY A TROUGH TO ITS NORTHEAST AND THIS SHOULD THEN TAKE
IT OUT TO SEA. THEREAFTER...THE MODEL CONSENSUS IS FOR THE UPPER
LEVEL RIDGE TO BUILD IN AND DOMINATE THAT LAST TWO TO TWO AND A HALF
DAYS OF THE PERIOD.
AS FOR POPS...WENT WITH SLIGHT CHANCE TO CHANCE POPS EARLY ON TUE
WITH THE WARM FRONT AND THEN INCREASED POPS LATE ON TUE INTO TUE
EVENING IN ADVANCE OF THE APPROACHING COLD FRONT AND SHORTWAVE THAT
THE MODEL CONSENSUS TAKES ACROSS THE OH VALLEY REGION OR THE CWA ON
TUE NIGHT. THE BOUNDARY SHOULD CONTINUE SLIPPING SOUTH ON WED AND
CONTINUED CHANCE POPS DURING WED...BUT GRADUALLY LOWERED POPS IN THE
NORTH FARTHER AWAY FROM THE BOUNDARY. A SFC LOW MAY DEVELOP ALONG
THE BOUNDARY AS THE UPPER LOW APPROACHES AROUND MIDWEEK AND SLOW THE
SOUTHWARD PROGRESS OF THE FRONT AND HOLD IN CHANCES FOR ISOLATED TO
SCATTERED CONVECTION AS THE SFC LOW AND UPPER SYSTEM PROBABLY TRACK
JUST TO OUR SOUTH ACROSS THE TN VALLEYS. ONCE THE UPPER SYSTEM
TRACKS EAST...PRECIP CHANCES WILL DIMINISH LATE THU NIGHT OR FRI.
FOR NOW THE END OF THE FORECAST IS EXPECTED TO BE DRY...WITH UPPER
LEVEL RIDGING DOMINATING. WITH THIS RIDGE...OPTED TO FAVOR THE ECMWF
RUNS.
TEMPERATURES SHOULD BE WARMEST AND MOST ABOVE NORMAL ON TUESDAY AND THEN
MORE MODEST DEPARTURES OF ABOUT 5 DEGREES ABOVE NORMAL AT THE END OF
THE PERIOD. OVERNIGHT LOWS SHOULD AVERAGE AT LEAST 5 DEGREES ABOVE
NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 738 PM EDT SUN APR 1 2012
VFR CONDITIONS WILL START THE EVENING HOURS. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO CREEP SOUTH INTO NORTHEAST KENTUCKY
OVERNIGHT. RIGHT NOW...IT DOES APPEAR THAT THE BEST THREAT WILL BE
ALONG AND EAST OF A LINE FROM MOREHEAD...TO JACKSON...TO HARLAN.
OTHERWISE...SOME PATCHY VALLEY FOG IS EXPECTED WITH THE CURRENT CLEAR
SKIES. WILL HOLD THINGS AT MVFR RIGHT NOW WITH PERHAPS BETTER
SOUTHERLY WINDS KEEPING THE FOG AT BAY. THIS COULD CHANGE HOWEVER.
OTHERWISE...THE SHOWERS...STORMS...AND ANY FOG WILL DEPART TOMORROW
MORNING...LEAVING BEHIND VFR CONDITIONS FOR THE DAYLIGHT HOURS.
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...GEOGERIAN
LONG TERM....JP
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1252 AM EDT SAT MAR 31 2012
.Forecast Update...
Issued at 1250 AM EDT Mar 31 2012
The storms have weakened quite a bit across the area with just a
couple of stronger storms remaining across the western portion of
the forecast area. These should weaken over the next hour or two as
well. Rain chances will continue to diminish from northwest to
southeast overnight. The ongoing forecast is in good shape, so have
made only some minor tweaks to POPs and temps.
Issued at 1010 PM EDT Mar 30 2012
Strong to marginally severe storms with hail were across southern
Indiana as of 2Z. Several reports of pea to dime size hail have
been received with one report of quarter size hail in Austin, IN
which has been the strongest storm in our area so far. Expect
strong to marginally severe storms to continue through around 1AM
EDT before diminishing to garden variety t-storms as the line
continues to sink south into Kentucky and weaken. Only made some
minor tweaks to POPs, dewpts, and temps based on current trends this
evening. Temperatures should hold in the 50s for lows tonight.
After it gets done raining, we may see a period of only partly
cloudy or even clear skies. With plentiful moisture at the sfc,
this may allow for some light fog to form. However, don`t expect
any widespread fog due to the mixey nature of the atmosphere so will
leave fog out of the forecast as of now. Also, any clearing would
be brief as upstream obs as well as soundings indicate a good
stratus layer will build into the area before sunrise and stick
around through the morning hours.
Update issued at 840 PM EDT Mar 30 2012
A line of showers/t-storms ahead of/along a sfc cold front was
making steady progress southeast into our area this evening. These
storms have decreased in intensity somewhat and thus a severe
t-storm watch was not issued. Latest model trends indicated that it
will continue to sink south throughout the evening hours and weaken
as it does so. Still think portions of southern Indiana and
northern KY may see some strong storms with small hail and 40 mph
winds, but any severe threat should be diminishing this evening.
Updated the grids to reflect the latest timing of this line of
showers/storms through the forecast area tonight. Also, tweaked
cloud cover overnight to better match the line of storms, some brief
clearing just behind the front, and then low stratus that is
anticipated just before sunrise through early afternoon.
.Short Term (This Afternoon through Saturday Night)...
Issued at 405 PM EDT Mar 30 2012
Afternoon satellite imagery and observations reveal that the warm
front has moved well north of our forecast area. South of this warm
front, the atmosphere continues to destabilize with time. With
current temperatures in the upper 70s to the lower 80s and dewpoints
in the upper 50s to the lower 60s is resulting in mixed layer CAPE
values in the 1250-1750 J/Kg range. Surface lifted indices based
on RUC proximity soundings are running around -4 to -6 degrees
Celsius. Atmosphere remains generally uncapped across the
southeastern/eastern sections of the forecast area. However some
weak capping/CINH still exists out in areas west of I-65.
Sufficient mixing over the next few hours will likely mix that cap
out.
For the rest of the afternoon, we expect partly to mostly sunny
skies with isolated showers and thunderstorms being possible across
portions of the area. The greatest concentration of convection will
generally be east of I-65 where we have a local maxima in the
dewpoint field. Temperatures will remain in the upper 70s and lower
80s through the early evening before dropping into the upper 70s
toward sunset.
As for tonight, the latest high resolution models agree that
convection will continue to develop along a southward moving cold
front which is currently located across central IL, IN, and OH.
This line of convection will likely move eastward as it will be
embedded in the faster mid-level low aloft. However, the line will
slowly sag southward with time. The consensus of the latest models
have trended slower as they adjust to the initial conditions that
are being ingested into the model. Therefore, the slower solution
would keep the bulk of this thunderstorm activity concentrated north
of the Ohio River early this evening. Current thinking is that the
line will likely sag southward to near the Ohio River by 10-11 PM
EDT. As this line head south, it will be encountering a slowly
stabilizing airmass due to the loss of heating and nocturnal PBL
stabilization.
Despite the weaker instability, this line of storms should remain
largely intact as it approaches the Ohio River later this evening.
The main threats still appear to be damaging winds and large hail.
The tornado threat appears to be rather low across our area as
overall bulk shear values decrease the further south you go of the
Ohio River. As the line passes south of the Ohio River, expect the
line to weaken and gradually dissipate as it sinks further south
into KY. For this reason, we will keep highest PoP chances tonight
across southern Indiana and the northern parts of KY and have lesser
chances across southern KY. Overnight lows will cool into the
mid-upper 50s.
Surface frontal boundary is expected to push south of the state
early Saturday with high pressure building into the region. Partly
to mostly sunny skies are expected with highs topping out in the
upper 60s in the Bluegrass region and lower 70s in the central.
Warmest temperatures will be across the south/southwest with
mid-upper 70s. Overnight lows Saturday night will be in the upper
30s-lower 40s in the northeast with mid-upper 40s elsewhere.
.Long Term (Sunday through Friday)...
Updated at 330 PM EDT Mar 30 2012
Ohio Valley will be positioned in northwest mid level flow between
ridging over the south central CONUS and shortwave moving from the
eastern Great Lakes to New England on Sunday. Surface low associated
with northeast shortwave will drag a cold front south toward the
Ohio River by Sunday afternoon. At this point, will continue to keep
forecast dry however may have to eventually add low chance pops
across northern CWA for afternoon showers and storms. Looking for
highs in the low 80s on Sunday as skies stay mostly sunny to partly
cloudy.
Ridge axis slides east to the middle Mississippi River Valley Sunday
night with frontal boundary mentioned above sliding southwest over
the CWA from a backdoor entrance. Front then looks to stall as it
becomes parallel to the mid level flow. Will also continue to keep
this period dry as models do not show enough deep moisture to
warrant pops at this time. Could see a nice gradient in low
temperatures on Sunday night dependent on how much progress front
makes. Will go with low 60s west to upper 50s east.
Closed upper low will make its way to the southern plains on Monday
with surface low developing over the middle Mississippi River
Valley. The resultant tightening pressure gradient will create
steady southwesterly flow and likely lift stalled frontal boundary
back northeast as a warm front. Will include slight chance for a
shower or thunderstorm as this occurs. This will be the warmest day
of the period with low to mid 80s.
Will likely see a lull in activity sometime Monday evening before
more widespread precipitation moves over the area through midweek.
That being said, will leave chance pops in the east for departing
warm front induced showers and storms and uncertainty in timing.
Lows around 60 can be expected.
Confidence in forecast decreases from Tuesday on as models continue
to have trouble with timing on closed upper low meandering from the
southern Plains to the Tennessee Valley or the Gulf Coast states.
Adding to the uncertainty, models disagree on northern stream energy
and its associated surface features dragging a cold front through.
ECMWF is more aggressive with front, dragging it through the region
by Tuesday night, with closed upper low slower and further south.
Meanwhile, GFS/GEM are faster with the upper low which combines the
ample Gulf moisture with the front sagging south from northern
stream system. This scenarios could result from the differing model
solutions. 1.) The ECMWF solution would result in a quick-hitting
shower and storm episode from Tuesday afternoon through Wednesday
morning. 2.) The GFS/GEM solution would bring a prolonged
precipitation event from Tuesday afternoon through at least Thursday
evening as upper low would be further north and slower to move
through. Will lean toward the first solution at this point with best
chances for showers and storms Tuesday afternoon through Wednesday
morning. Thereafter, will keep forecast dry until models converge
on a solution.
Looking for a cool down from midweek with either solution as we will
either be in a post frontal cooler airmass or underneath the
influence of an upper low. Highs in the mid 60s each day with lows
in the mid 40s.
&&
.Aviation (06Z TAF Issuance)...
Updated at 1245 AM EDT Mar 31 2012
The strong storms have weakened quite a bit over the last hour with
just a few clusters of thunderstorms remaining. The rest of the
activity is mainly showers. LEX may see a lightning strike or two
over the next hour, but should be just SHRA by 06Z. The strongest
storm in the area is in south central KY, but it has the chance to
weaken and may stay north of BWG. Therefore, will continue to carry
only VCTS there.
Behind the line of showers and storms ceilings will remain VFR for a
couple of hours. The models do indicate a stratus layer will then
build down. Ceilings are expected to drop to around 1500 ft. and
remain there through mid day. These clouds should scatter out by mid
day with skies clearing in the afternoon. Winds will be generally
light and out of the north to NNW.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS/EER
Short Term.......MJ
Long Term........BJS
Aviation.........EER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1028 AM EDT SAT MAR 31 2012
.SYNOPSIS...
DRY AND SEASONABLY COOL WEATHER CAN BE EXPECTED TODAY AS HIGH
PRESSURE BUILDS ACROSS THE LOWER GREAT LAKES. A CROSSING
DISTURBANCE WILL BRING ANOTHER COLD FRONT AND THE CHANCE FOR
SHOWERS ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CLOUDS CONTINUE TO HANG TOUGH IN THE COLD AIR ADVECTION. PUSHED
BACK BKN CONDITIONS A FEW HOURS BASED ON LATEST RUC SOUNDINGS. THE
REST OF THE FORECAST REMAINS UNCHANGED. DIURNAL TRACE TODAY SHOULD
BE AROUND 10F OR LESS.
DECREASED CLOUDS AND DRIER AIR MASS WL SUPPORT RADIATIVE COOLING
AS LIGHT SURFACE WIND VEERS WITH THE ADVANCE OF A SHORTWAVE IN THE
AFOREMENTIONED NORTHWEST FLOW. OVERNIGHT TEMPERATURES WERE ALSO
FORECAST NR THE NORMALS USING SREF MEANS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
AMPLIFYING RIDGE OVR THE MS VALLEY WILL STEEPEN THE NW FLOW OVER
THE AREA DURING THE SHORT TERM. LATEST MODEL RUNS SHOW A
SHORTWAVE TROUGH DIVING SOUTHEAST ACROSS THE EASTERN GREAT LAKES
SUNDAY INTO SUNDAY NIGHT. MODELS CONT TO INDICATE VARYING DEGREES
OF QPF AS THAT FEATURE PUSHES A COLD FRONT ACROSS THE REGION. WL
MAINTAIN CHANCE POPS FOR PASSAGE OF THIS SYSTEM...AND HAVE USED A
GUIDANCE BLEND WITH COOLER TEMPERATURES THAN PREVIOUS FORECAST FOR
MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
WRN STATES TROF IS FORECAST TO DVLP TWD THE PLAINS/WRN LAKES BY
MONDAY NGT...PUSHING THE RIDGE ACRS THE ERN HALF OF THE COUNTRY
BEFORE DIGGING AN EAST COAST TROF BY THE END OF THE PD. GIVEN MDL
DIFFERENCES...HAVE GENLY PERSISTED WITH THE PREVIOUS LONG TERM
FORECAST...BUT A BRIEF TEMPERATURE MODERATION AND MID WEEK CDFNT
CAN BE ANTICIPATED FOR THE LONG TERM PD.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
CIGS ARE STILL IFR / LOW END MVFR AND THAT WILL PERSIST THROUGH
THE EARLY AFTN HOURS WHEN BASES LIFT TO MVFR LEVELS ABV 2KFT. STILL
EXPECT CIGS TO CARRY THROUGH MOST OF THE AFTN. VFR CONDITIONS WILL
RETURN BY EARLY EVENING.
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
NO WIDESPREAD IFR WEATHER EXPECTED.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
NEAR TERM...98
AVIATION...98
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1145 PM EDT SUN APR 1 2012
.SYNOPSIS...
ISSUED AT 347 PM EDT SUN APR 1 2012
A STALLED FRONT WILL BRING SOME ISOLATED SHOWERS THIS EVENING.
FAIR WEATHER IS EXPECTED FOR MONDAY THEN SOME SHOWERS AND AN
ISOLATED THUNDERSTORM IS POSSIBLE MONDAY NIGHT AS LOW PRESSURE
MOVES JUST SOUTH OF LOWER MICHIGAN. CANADIAN HIGH PRESSURE WILL
BUILD IN FOR WEDNESDAY THROUGH THE END OF THE WEEK WITH FAIR
WEATHER AND FROSTY OVERNIGHT LOWS.
&&
.UPDATE...
ISSUED AT 722 EDT SUN APR 1 2012
I UPDATED THE SHORT TERM GRIDS TO TRY TO TRACK THE BAND OF FGEN
CREATED SHOWERS THAT IS SLOWLY MOVING SOUTHWARD ACROSS THE CWA.
FOR THE MOST PART THE SHOWERS ARE ALOFT. LOOKING OUT THE OFFICE
WINDOW TO THE NORTH I CAN SEE THE VIRGA NICELY. SOME OF THE
STRONGER CELLS DO HAVE SHOWERS REACHING THE GROUND. LDM DID HAVE
SHOWERS FOR ABOUT A HALF HOUR AROUND 6 PM THIS EVENING. THIS AREA
SHOULD LARGELY BE SOUTH OF THE CWA BY MIDNIGHT. I EXPECT THE SKY
WILL CLEAR TOO AS THE NORTHEAST LOW LEVEL WINDS KICK IN BRINGING
MUCH DRIER AIR INTO THE CWA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 347 PM EDT SUN APR 1 2012
BANDS OF LIGHT OVERRUNNING SHOWERS ACROSS NORTHERN WISCONSIN WILL
BE MOVING INTO THE FORECAST AREA THROUGH THE EVENING. MOST OF
THESE SHOWERS ARE LIGHT AND SOME OF THE RAIN IS EVAPORATING BEFORE
REACHING THE GROUND...SO SLIGHT CHANCE POPS AND ISOLATED WORDING
SHOULD COVER IT. HRRR RUC HAS HAD A GOOD HANDLE ON THIS THROUGH
THE DAY...SO FOLLOWED IT FOR POPS OVERNIGHT.
AFTER A BREAK IN THE PRECIP...MORE SHOWERS SHOULD MOVE IN MONDAY
EVENING AS SFC LOW APPROACHES. SOME ELEVATED INSTABILITY EXISTS
BUT IT IS MARGINAL...SO WENT WITH ISOLATED THUNDER CHANCES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 PM EDT SUN APR 1 2012
LOW PRESSURE IS EXPECTED TO BE SLIDING EAST OVER THE LOWER GREAT
LAKES ON TUESDAY. IT STILL LOOKS LIKE SOME POTENTIAL FOR STRONG
STORMS WILL HAIL...ESPECIALLY EARLY IN THE DAY...AND MAINLY ALONG
AND SOUTH OF I-96. SYSTEM LOOKS A BIT SLOWER NOW...SO HAVE POPS
GOING THROUGHOUT THE DAY.
VERY DRY AIR FOLLOWS THE SYSTEM BY TUESDAY EVENING WITH CLEARING
SKIES. COULD BE THE THREAT OF FROST BY WEDNESDAY MORNING...BUT
THIS SHOULD BE PATCHY OVER INLAND AREAS AS THE PRESSURE GRADIENT
SHOULD STILL CAUSE SOME MIXING THROUGH THE NIGHT. LOOKS LIKE THE
BEST CHANCE OF FROST WILL COME LATE WEDNESDAY NIGHT AND LATE
THURSDAY NIGHT AS THE SURFACE RIDGE AXIS WILL BE NEARBY GIVING US
LIGHTER WINDS AND SINKING TEMPS TO THE LOW TO MID 30S IN MANY
LOCATIONS.
NEXT CHANCE OF RAIN SHOULD NOT COME UNTIL SATURDAY NIGHT INTO
SUNDAY. STILL SOME UNCERTAINTY IN THIS GIVEN THE STRONG RIDGE TO
OUR EAST. BUT GENERAL GUIDANCE CONSCIENCE SHOWS A FRONT COMING
THROUGH ON SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY MORNING)
ISSUED AT 1145 PM EDT SUN APR 1 2012
VFR TO MVFR CONDITIONS ANTICIPATED OVERNIGHT. PATCHY MVFR WILL BE
DUE TO 5SM TYPE VISBYS IN VERY LIGHT FOG. VFR CONDITIONS ANTICIPATED
MONDAY THRU MONDAY EVENING. SOME LOW CLOUDS WILL LIKELY BEGIN TO
MOVE IN FROM THE SW INTO KMKG AND KAZO LATE TOMORROW EVENING... BUT
I DO NOT BELIEVE THAT SHOWERS OR STORMS WILL DEVELOP UNTIL AFTER 06Z
TUE WHEN THE ELEVATED INSTABILITY WILL BEGIN TO RAMP UP.
&&
.MARINE...
ISSUED AT 256 PM EDT SUN APR 1 2012
WINDS AND WAVES WILL BE RELATIVELY CALM THIS WEEK.
&&
.HYDROLOGY...
ISSUED AT 256 PM EDT SUN APR 1 2012
NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM....JK
AVIATION...LAURENS
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
722 PM EDT SUN APR 1 2012
.SYNOPSIS...
ISSUED AT 347 PM EDT SUN APR 1 2012
A STALLED FRONT WILL BRING SOME ISOLATED SHOWERS THIS EVENING.
FAIR WEATHER IS EXPECTED FOR MONDAY THEN SOME SHOWERS AND AN
ISOLATED THUNDERSTORM IS POSSIBLE MONDAY NIGHT AS LOW PRESSURE
MOVES JUST SOUTH OF LOWER MICHIGAN. CANADIAN HIGH PRESSURE WILL
BUILD IN FOR WEDNESDAY THROUGH THE END OF THE WEEK WITH FAIR
WEATHER AND FROSTY OVERNIGHT LOWS.
&&
.UPDATE...
ISSUED AT 722 EDT SUN APR 1 2012
I UPDATED THE SHORT TERM GRIDS TO TRY TO TRACK THE BAND OF FGEN
CREATED SHOWERS THAT IS SLOWLY MOVING SOUTHWARD ACROSS THE CWA.
FOR THE MOST PART THE SHOWERS ARE ALOFT. LOOKING OUT THE OFFICE
WINDOW TO THE NORTH I CAN SEE THE VIRGA NICELY. SOME OF THE
STRONGER CELLS DO HAVE SHOWERS REACHING THE GROUND. LDM DID HAVE
SHOWERS FOR ABOUT A HALF HOUR AROUND 6 PM THIS EVENING. THIS AREA
SHOULD LARGELY BE SOUTH OF THE CWA BY MIDNIGHT. I EXPECT THE SKY
WILL CLEAR TOO AS THE NORTHEAST LOW LEVEL WINDS KICK IN BRINGING
MUCH DRIER AIR INTO THE CWA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 347 PM EDT SUN APR 1 2012
BANDS OF LIGHT OVERRUNNING SHOWERS ACROSS NORTHERN WISCONSIN WILL
BE MOVING INTO THE FORECAST AREA THROUGH THE EVENING. MOST OF
THESE SHOWERS ARE LIGHT AND SOME OF THE RAIN IS EVAPORATING BEFORE
REACHING THE GROUND...SO SLIGHT CHANCE POPS AND ISOLATED WORDING
SHOULD COVER IT. HRRR RUC HAS HAD A GOOD HANDLE ON THIS THROUGH
THE DAY...SO FOLLOWED IT FOR POPS OVERNIGHT.
AFTER A BREAK IN THE PRECIP...MORE SHOWERS SHOULD MOVE IN MONDAY
EVENING AS SFC LOW APPROACHES. SOME ELEVATED INSTABILITY EXISTS
BUT IT IS MARGINAL...SO WENT WITH ISOLATED THUNDER CHANCES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 PM EDT SUN APR 1 2012
LOW PRESSURE IS EXPECTED TO BE SLIDING EAST OVER THE LOWER GREAT
LAKES ON TUESDAY. IT STILL LOOKS LIKE SOME POTENTIAL FOR STRONG
STORMS WILL HAIL...ESPECIALLY EARLY IN THE DAY...AND MAINLY ALONG
AND SOUTH OF I-96. SYSTEM LOOKS A BIT SLOWER NOW...SO HAVE POPS
GOING THROUGHOUT THE DAY.
VERY DRY AIR FOLLOWS THE SYSTEM BY TUESDAY EVENING WITH CLEARING
SKIES. COULD BE THE THREAT OF FROST BY WEDNESDAY MORNING...BUT
THIS SHOULD BE PATCHY OVER INLAND AREAS AS THE PRESSURE GRADIENT
SHOULD STILL CAUSE SOME MIXING THROUGH THE NIGHT. LOOKS LIKE THE
BEST CHANCE OF FROST WILL COME LATE WEDNESDAY NIGHT AND LATE
THURSDAY NIGHT AS THE SURFACE RIDGE AXIS WILL BE NEARBY GIVING US
LIGHTER WINDS AND SINKING TEMPS TO THE LOW TO MID 30S IN MANY
LOCATIONS.
NEXT CHANCE OF RAIN SHOULD NOT COME UNTIL SATURDAY NIGHT INTO
SUNDAY. STILL SOME UNCERTAINTY IN THIS GIVEN THE STRONG RIDGE TO
OUR EAST. BUT GENERAL GUIDANCE CONSCIENCE SHOWS A FRONT COMING
THROUGH ON SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 722 PM EDT SUN APR 1 2012
CONDITIONS SHOULD BECOME SOLID VFR (NEARLY CLEAR ACTUALLY) BY 06Z
AS THE COLDER AIR SLOWLY FILTERS IN FROM THE NORTH THIS EVENING.
THERE IS A BAND OF SHOWERS FROM S OF LDM TO DTW AT 715 PM SLOWLY
DROPING SOUTHWARD. I DO NOT EXPECT MUCH OF THE SHOWER ACTIVITY TO
REACH THE GROUND AS IT FALLING FROM A MID LEVEL CLOUD DECK AND
THERE IS ABOUT 10000 FT OF DRY AIR BETWEEN THE MID LEVEL CLOUD
DECK AND THE MORE MOIST AIR LAYER NEAR THE GROUND. I KEEP THE VCSH
FOR THAT AT ALL TAF SITES THIS EVENING.
THAT IS THE BOUNARY OF THE MORE MOIST AIR AT LOW LEVEL FROM THE DRIER
AIR COMING IN FROM ONTARIO OVERNIGHT. THUS ALL THE LOW CLOUDS THAT
REMAIN IN THE I-94 AREA WILL BE GONE BY 03Z. LIGHT NORTHEAST WINDS
WILL PREVAIL AT ALL TAF SITES OVERNIGHT. A LARGE HIGH PRESSURE
RIDGE OVER MICHIGAN MONDAY WITH DRY EAST WINDS AT LOW LEVELS
SHOULD RESULT IN NEARLY CLEAR SKIES MOST OF THE DAY. SOME
INCREASING CLOUDS CAN BE EXPECTED TOWARD EVENING AS THE WARM AIR
TRIES TO PUSH BACK NORTHEAST AGAIN.
&&
.MARINE...
ISSUED AT 256 PM EDT SUN APR 1 2012
WINDS AND WAVES WILL BE RELATIVELY CALM THIS WEEK.
&&
.HYDROLOGY...
ISSUED AT 256 PM EDT SUN APR 1 2012
NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM....JK
AVIATION...WDM
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
330 PM CDT SAT MAR 31 2012
.DISCUSSION...
CONSIDERABLE CLOUDINESS CONTINUES TO PLAGUE MUCH OF THE FA AT MID
AFTERNOON. ONLY THE FAR WESTERN COUNTIES HAVE NEAR FULL SUN. SOME
THINNING APPEARS TO BE OCCURRING OVER WEST CENTRAL WI. THE HRRR IS
TRYING TO SHOW CLEARING WORKING INTO FAR EASTERN MN AND WEST
CENTRAL WI BY THIS EVENING. HOWEVER...CLEARING OR NOT...THE
PRESSURE GRADIENT WILL WEAKEN TONIGHT WITH SATURATION DEVELOPING
DURING THE OVERNIGHT HOURS. THIS WILL LIKELY TO LEAD FOG AND MORE
STRATUS REFORMING. NAM BUFKIT HYDROLAPSE SHOWS A NICE INCREASE
JUST ABOUT EVERYWHERE TONIGHT DURING THE LATE NIGHT HOURS.
INDICATED AREAS OF FOG IN THE FORECAST...BUT DENSE FOG IS NOT OUT
OF THE QUESTION SUNDAY MORNING.
IN ADDITION...A WEAK SHORT WAVE IS PASSING BY EARLY THIS EVENING.
SEVERAL MODEL SOLUTIONS STILL TRY TO DEVELOP SOME SHOWERS OVER
CENTRAL MN AND PASS THEM ACROSS THE TWIN CITIES AND WEST CENTRAL
WI. CONFIDENCE IS NOT HIGH AND HAVE KEPT THE FORECAST DRY BUT THE
DIFFERENTIAL HEATING OCCURRING TO OUR WEST NOW IS A CONCERN. MUCH BETTER
INSTABILITY IS DEVELOPING OVER WESTERN IA ATTM AND THE LOW LEVEL
MOISTURE TRANSPORT INCREASES EARLY THIS EVENING BETWEEN KDSM AND
KMKE. SO SOME STORMS ARE POSSIBLE JUST TO OUR SOUTH OF OUR FA THIS
EVENING.
SUNDAY WILL BE THE WARMEST DAY OF THE NEXT SEVEN FOR MANY AREAS. MUCH
WILL DEPEND ON THE AMOUNT OF STRATUS AND FOG IN THE MORNING...BUT
WEST CENTRAL THROUGH SOUTH CENTRAL MN HAVE A REALLY GOOD CHANCE
OF SEEING HIGHS REACH WELL INTO THE 80S. READINGS IN THE 80S ARE
OCCURRING RIGHT NOW TO THE WEST AND SOUTH OF KFSD WITH H85
TEMPERATURES OF +16 TO +18 DEGREES C. SOUTHWEST AREAS OF MN WILL
BE SOME 2 TO 3 DEGREES C ABOVE THIS SUNDAY AFTERNOON. A HIGH NEAR
90 IS NOT OUT OF THE QUESTION AROUND LUVERNE AND PIPESTONE.
A LOW PRESSURE SYSTEM AND ASSOCIATED FRONTAL BOUNDARIES WILL MOVE
INTO THE FA SUNDAY NIGHT. ELEVATED INSTABILITY DEVELOPS BY EVENING
NORTH OF THE WARM FRONT ACROSS CENTRAL MN AND PUSHES INTO
NORTHWEST WI DURING THE NIGHT. LOW LEVEL MOISTURE TRANSPORT
INCREASES DRAMATICALLY ACROSS EAST CENTRAL MN AS THE LOW LEVEL
JET INCREASE TO 40 KNOTS. LAPSE RATES ARE BETTER THAN 6.5 DEG C/KM
ALONG WITH A FAVORABLE DIFFERENTIAL TEMPERATURE ADVECTION PATTERN.
THE CROSSOVER BETWEEN 850 AND 500 MB IS RATHER IMPRESSIVE BUT A
LITTLE NORTH OF OUR CWA. ALL OF THIS POINTS TO SOME STORMS
DEVELOPING ACROSS CENTRAL MN AND MOVING TOWARDS KDLH. A FEW STORMS
WITH LARGE HAIL MAY OCCUR.
THERE STILL REMAINS MODEL SPREAD FROM MONDAY THROUGH TUESDAY ON
MOVING THE LOW AND TRAILING COLD FRONT ACROSS THE FA. THE ECMWF
REMAINS THE SLOWEST WHILE THE NAM IS THE FASTEST. THE GEM AND GEFS
ARE PRETTY SIMILAR. TRIED TIMING PRECIPITATION BASED ON THIS
COMBINATION. THIS YIELDED LIKELY POPS OVER EAST CENTRAL MN MONDAY
AFTERNOON AND ACROSS PARTS OF WEST CENTRAL WI MONDAY EVENING. HIGH
TEMPERATURES ON MONDAY MAY BE WARMER THAN FORECAST FOR SOUTHEAST
AREAS OF THE FA IF THE CLOUDINESS/SHOWERS/THUNDERSTORMS DO NOT
DEVELOP AS FORECAST.
DRY WEATHER FORECAST IN THE WAKE OF THE FRONT FOR TUESDAY THROUGH
FRIDAY AS HIGH PRESSURE STALLS OVER THE WESTERN GREAT LAKES. HIGHS
DURING THE PERIOD FROM 55 TO 65 WITH LOWS FROM 35 TO 45. A PACIFIC
COLD FRONT IS THEN PROJECTED ACROSS THE REGION FOR NEXT SATURDAY.
HOWEVER...THE ECMWF REMAINS THE SLOWEST ON MOVING THE FRONT
THROUGH ALONG WITH WEAKENING THE SYSTEM AS IT APPROACHES. FOR
NOW...INDICATED ONLY A SMALL CHANCE FOR RAIN SHOWERS.
&&
.AVIATION.../18Z TAF ISSUANCE/
IFR/LIFR CEILINGS AND SOME BR REMAIN OVER MUCH OF THE AREA.
LIFTING/ERODING OVER FAR WESTERN AREAS. THIS TREND EXPECTED TO
CONTINUE THROUGH THE AFTERNOON...MAKING VFR OVER EAST CENTRAL MN
AFTER 22Z. WEST CENTRAL WISCONSIN TO REMAIN MVFR THROUGH 00Z. LIKELY
WILL SEE WHATEVER CLOUD IS LEFTOVER OVER THE EASTERN AREAS TO BUILD
SLIGHTLY WEST AGAIN TONIGHT...AS WEAK BOUNDARY DROPS INTO THE
REGION. FOG MAY BECOME AN ISSUE AGAIN OVERNIGHT AS WINDS BECOME
LIGHT IN AND NEAR THE VICINITY OF THE BOUNDARY. WILL MENTION IFR
CONDITIONS DEVELOPING INTO WESTERN WISCONSIN AND HINT ON THAT
POSSIBILITY AGAIN INTO MN PORTION MAINLY AFTER 06Z SUNDAY. SOME
INDICATION OF MID/HIGH CLOUDS COMING IN WITH BOUNDARY AND IT MAY
LIMIT FOG FORMATION SOMEWHAT. WILL HAVE TO MONITOR CLOUD TRENDS
INTO THE EVENING. EXPECT LOWER CLOUDS TO BREAK UP THROUGH 15Z
SUNDAY AND INCREASE SOUTHEAST WINDS AGAIN INTO THE AFTERNOON WITH
GUSTS 20-25 KNOTS POSSIBLE.
KMSP...MVFR CIGS LIFTING THIS AFTERNOON TO MVFR AFTER 22Z. EXPECT
SOME REDEVELOPMENT OF ADVECTION OF REMAINING CLOUD COVER TO THE EAST
BACK INTO THE REGION OVERNIGHT. WILL HAVE TO MONITOR CLOUDS TRENDS
INTO THE EVENING. BUFKIT PROFILES DO SUGGEST FOG FORMING OVERNIGHT
AS WELL...AND SOME MID/HIGH LEVEL CLOUDS POSSIBLE WHICH MAY LIMIT
FOG FORMATION SOMEWHAT. EXPECT ANY LOWER IFR/MVFR CEILINGS/VSBYS TO
MOVE OUT THROUGH 15Z WITH MID/HIGH LEVEL CLOUDS THEREAFTER AHEAD OF
NEXT BOUNDARY. SOUTHEAST TO EAST WINDS INTO THE EVENING BECOMING
LIGHT...AND INCREASING OUT OF THE SOUTHEAST AGAIN SUNDAY
MORNING...AND A BIT GUSTY INTO THE AFTERNOON.
OUTLOOK...
SUNDAY...BECOMING VFR BY LATE MORNING.
LATE SUNDAY NIGHT-MONDAY...MVFR POSSIBLE WITH SHRA/TSRA AS A FRONT
MOVES THROUGH.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/DWE
AREA FORECAST DISCUSSION
NWS DULUTH MN
126 PM CDT SAT MAR 31 2012
.AVIATION.../18Z TAF ISSUANCE/
WIDESPREAD LIFR TO IFR CONDITIONS WILL BE FOUND ACROSS THE REGION
TODAY...ALTHOUGH CONDITIONS COULD IMPROVE TO VFR IN SOME OF THE
WESTERN AREAS. THEN IT LOOKS LIKE WIDESPREAD MVFR TO IFR/LIFR
CONDITIONS WILL ONCE AGAIN DEVELOP AGAIN TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 635 AM CDT SAT MAR 31 2012/
AVIATION...12Z TAFS.
IFR/LIFR CIGS/VSBYS WITH FOG AT ALL SITES...AND -DZ AT KDLH. THE
FOG WILL PERSIST THROUGH 14Z-15Z WHEN APPROACHING SHORT WAVE AND
SFC FRONT WILL IMPROVE CIGS/VSBYS INTO MVFR RANGE. VCSH AT ALL
LOCATIONS EXCEPT KHYR AS SHORT WAVE/FRONT MOVE THROUGH THE FA
THROUGH 00Z SUNDAY. LLWS AHEAD OF THE FRONT. AFTER
FROPA...CIGS/VSBYS IMPROVE TO VFR.
PREV DISCUSSION... /ISSUED 331 AM CDT SAT MAR 31 2012/
SHORT TERM...
TODAY THROUGH SUNDAY AFTERNOON...
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE PATCHY FOG
THROUGHOUT THE NORTHLAND WITH DENSE FOG ALONG THE NORTH SHORE AND
AROUND THE TWIN PORTS THIS MORNING...ALONG WITH RAIN SHOWERS MOVING
IN FROM THE NW TODAY...WITH PATCHY FREEZING DRIZZLE POSSIBLE IN THE
TIP OF THE ARROWHEAD BEFORE TEMPERATURES WARM LATE THIS MORNING.
UPPER LEVEL FLOW WILL REMAIN QUASI-ZONAL ACROSS MUCH OF THE CONUS
TODAY...BUT BECOME AMPLIFIED ON SUNDAY AS AN UPPER TROUGH DIGS
INTO THE WRN U.S. A WEAK 500MB S/W AND ASSOCIATED SFC TROUGH OVER
THE WRN DAKOTAS/SRN SASKATCHEWAN/MANITOBA REGION WILL TRACK TO THE
EAST THIS MORNING INTO WRN ONTARIO/NRN MN. RAIN SHOWERS WILL
ACCOMPANY THIS SYSTEM...MAINLY ACROSS THE NRN COUNTIES OF THE
FORECAST AREA. A FEW SHOWERS AND STORMS ARE ONGOING THIS MORNING
AROUND WINNIPEG...ALONG THE NRN EDGE OF A WARM/MOIST/UNSTABLE AIR
MASS BEING ADVECTED IN FROM THE SOUTH AND CO-LOCATED WITH A
NARROW BAND OF LOW LEVEL F-GEN. THIS PRECIP WILL TRY TO MOVE INTO
NE MN THIS MORNING...BUT WILL ENCOUNTER A MORE STABLE AIR MASS AND
DIMINISH IN INTENSITY THROUGH MID MORNING. THE OTHER CONCERN WITH
THIS PRECIP BAND WILL BE THE POTENTIAL FOR FREEZING DRIZZLE INTO
MAINLY LAKE AND COOK COUNTIES BEFORE 10AM. AS THE SURGE OF WARM
AIR ALOFT MOVES EWD OVER THE NEAR FREEZING SFC LAYER IN NE MN...THE
CHC FOR FREEZING PRECIP INCREASES. RUC SOUNDINGS AT ELY PRODUCE A
SATURATED THERMAL PROFILE NEAR FREEZING UP THROUGH 3000 FT...WITH
A VERY DRY LAYER ALOFT. SFC WINDS WILL EVENTUALLY VEER TO THE S/SW
AND USHER IN WARMER AIR FROM THE SOUTH BY LATE MORNING
TODAY...WHICH WILL ALLOW ANY PRECIP TO BECOME ALL LIQUID. LIQUID
PRECIP AMTS WILL RANGE FROM A TRACE UP TO A COUPLE TENTHS OF AN
INCH.
THE OTHER CONCERN IN THE SHORT TERM IS THE DENSE FOG AROUND THE
PERIPHERY OF LAKE SUPERIOR THIS MORNING. THE COMBINATION OF A
MOISTURE SFC LAYER...CONTINUOUS INFLUX OF COOL MOIST AIR FROM THE
EAST...AND A STRONG INVERSION AT THE TOP OF THE BOUNDARY LAYER ARE
ALL AIDING IN THE FORMATION AND PERSISTENCE OF FOG AROUND THE
NORTHLAND. WILL LIKELY SEE THE FOG CONTINUE TODAY AS LONG AS THE
WINDS REMAIN FROM THE EAST OFF THE LAKE. THE APPROACHING SFC
TROUGH SHOULD WIN OUT AND ALLOW WINDS TO VEER TO THE S/SW...WHICH
WILL HELP MIX DOWN SOME DRIER AIR ALOFT AND ERODE THE FOG LAYER BY
LATE MORNING. USUALLY TAKES LONGER THAN EXPECTED...SO MAY NEED TO
EXTEND DENSE FOG ADVISORY LONGER THAN 10AM. HOWEVER...FOR NOW WILL
KEEP WITH 10AM AS THE ENDING TIME.
THE DURATION OF THE EAST WINDS AND CLOUD LAYER WILL ALSO MITIGATE
HOW WARM TEMPERATURES GET TODAY. WITH CLOUD COVER EXPECTED THROUGH
A GOOD PORTION OF THE DAY...DECIDED TO DROP MAX TEMPS
TODAY...MAINLY IN NW WI. KEPT WITH 60S FOR INLAND LOCATIONS OF NE
MN...AND 40S AND 50S AROUND THE LAKE. TEMPS COOL INTO THE 30S AND
40S TONIGHT...AND WARM BACK INTO THE 60S AND LOWER 70S INLAND ON
SUNDAY...WITH 50S AROUND THE LAKE AS EAST WINDS RETURN. RIDGE OF
HIGH PRESSURE BUILDS IN ACROSS THE NRN PLAINS SUNDAY AS THE NEXT
SYSTEM PREPARES TO MOVE IN FROM THE SW SUNDAY NIGHT.
LONG TERM...
SUNDAY NIGHT THROUGH FRIDAY...
MODEL DIFFERENCES WITH THE MAGNITUDE OF THE FLATTENING/MOVING OF
THE UPPER RIDGE AND THE APPROACHING CLOSED UPPER LOW MOVING
THROUGH CANADA SUNDAY NIGHT. THIS ALSO PLAYS A ROLE IN THE AMOUNT
OF INSTABILITY FOR THUNDERSTORM DEVELOPMENT. USED A BLEND OF
QPF/POPS WITH THE MAJORITY OF THE THUNDERSTORMS HOLDING OFF UNTIL
AFTER 06Z MONDAY. THIS IS WHEN THETAE ADVECTION IS GREATEST. MODEL
DIFFERENCES CONTINUE ON MONDAY AS THE GFS IS QUICK TO MOVE A FRONT
THROUGH THE FA WHILE THE ECMWF/GEM/UKMET ARE THE SLOWEST. HAVE
SIDED WITH THE SLOWER APPROACH WHICH KEEPS THE INSTABILITY AXIS
NEARBY AND THE MENTION OF THUNDERSTORMS NEEDED. CONTINUED WITH THE
SLOWER MODELS MONDAY NIGHT AND LINGERED THE POPS. AN UPPER LEVEL
TROF MOVES THROUGH THE FA TUESDAY PUSHING THE PCPN E ALLOWING SFC
RIDGING TO BUILD IN. THE SFC HIGH BECOMES ANCHORED OVER THE
EASTERN GREAT LAKES TUESDAY NIGHT THROUGH FRIDAY KEEPING THE AREA
IN AN EASTERLY FLOW AND NO PCPN WITH THE DRY AIR FROM THE HIGH
LOCKED INTO THE FA.
AVIATION...06Z TAFS...
SKIES HAD CLEARED OVER KBRD...BUT MVFR CEILINGS HAVE ALREADY MOVED
BACK IN. IFR OR LOW MVFR CONDITIONS WILL PERSIST TONIGHT...WITH SOME
MIXED PRECIPITATION ACROSS THE FAR NORTH. DENSE FOG CAN BE
EXPECTED AROUND LAKE SUPERIOR. LATEST MODEL RUNS SUGGEST THE LOW
CEILINGS WILL BE SLOWER TO CLEAR ON SATURDAY...AND WE DELAYED THE
TIMING BY 1 TO 3 HOURS IN THE 06Z TAFS.
A SHORTWAVE AND TROUGH WILL ALSO BRING A CHANCE FOR SHOWERS
THROUGH SATURDAY...WITH THE BEST CHANCE ACROSS THE FAR NORTHEAST.
&&
.POINT TEMPS/POPS...
DLH 57 38 56 40 / 20 10 10 40
INL 60 33 60 40 / 40 10 10 30
BRD 66 43 72 51 / 10 10 10 20
HYR 58 40 68 47 / 10 10 10 30
ASX 56 39 57 43 / 10 10 10 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 2 PM CDT THIS AFTERNOON FOR MNZ021.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...BERDES
LONG TERM....DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
635 AM CDT SAT MAR 31 2012
.AVIATION...12Z TAFS.
IFR/LIFR CIGS/VSBYS WITH FOG AT ALL SITES...AND -DZ AT KDLH. THE
FOG WILL PERSIST THROUGH 14Z-15Z WHEN APPROACHING SHORT WAVE AND
SFC FRONT WILL IMPROVE CIGS/VSBYS INTO MVFR RANGE. VCSH AT ALL
LOCATIONS EXCEPT KHYR AS SHORT WAVE/FRONT MOVE THROUGH THE FA
THROUGH 00Z SUNDAY. LLWS AHEAD OF THE FRONT. AFTER
FROPA...CIGS/VSBYS IMPROVE TO VFR.
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT SAT MAR 31 2012/
SHORT TERM...
TODAY THROUGH SUNDAY AFTERNOON...
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE PATCHY FOG
THROUGHOUT THE NORTHLAND WITH DENSE FOG ALONG THE NORTH SHORE AND
AROUND THE TWIN PORTS THIS MORNING...ALONG WITH RAIN SHOWERS MOVING
IN FROM THE NW TODAY...WITH PATCHY FREEZING DRIZZLE POSSIBLE IN THE
TIP OF THE ARROWHEAD BEFORE TEMPERATURES WARM LATE THIS MORNING.
UPPER LEVEL FLOW WILL REMAIN QUASI-ZONAL ACROSS MUCH OF THE CONUS
TODAY...BUT BECOME AMPLIFIED ON SUNDAY AS AN UPPER TROUGH DIGS
INTO THE WRN U.S. A WEAK 500MB S/W AND ASSOCIATED SFC TROUGH OVER
THE WRN DAKOTAS/SRN SASKATCHEWAN/MANITOBA REGION WILL TRACK TO THE
EAST THIS MORNING INTO WRN ONTARIO/NRN MN. RAIN SHOWERS WILL
ACCOMPANY THIS SYSTEM...MAINLY ACROSS THE NRN COUNTIES OF THE
FORECAST AREA. A FEW SHOWERS AND STORMS ARE ONGOING THIS MORNING
AROUND WINNIPEG...ALONG THE NRN EDGE OF A WARM/MOIST/UNSTABLE AIR
MASS BEING ADVECTED IN FROM THE SOUTH AND CO-LOCATED WITH A
NARROW BAND OF LOW LEVEL F-GEN. THIS PRECIP WILL TRY TO MOVE INTO
NE MN THIS MORNING...BUT WILL ENCOUNTER A MORE STABLE AIR MASS AND
DIMINISH IN INTENSITY THROUGH MID MORNING. THE OTHER CONCERN WITH
THIS PRECIP BAND WILL BE THE POTENTIAL FOR FREEZING DRIZZLE INTO
MAINLY LAKE AND COOK COUNTIES BEFORE 10AM. AS THE SURGE OF WARM
AIR ALOFT MOVES EWD OVER THE NEAR FREEZING SFC LAYER IN NE MN...THE
CHC FOR FREEZING PRECIP INCREASES. RUC SOUNDINGS AT ELY PRODUCE A
SATURATED THERMAL PROFILE NEAR FREEZING UP THROUGH 3000 FT...WITH
A VERY DRY LAYER ALOFT. SFC WINDS WILL EVENTUALLY VEER TO THE S/SW
AND USHER IN WARMER AIR FROM THE SOUTH BY LATE MORNING
TODAY...WHICH WILL ALLOW ANY PRECIP TO BECOME ALL LIQUID. LIQUID
PRECIP AMTS WILL RANGE FROM A TRACE UP TO A COUPLE TENTHS OF AN
INCH.
THE OTHER CONCERN IN THE SHORT TERM IS THE DENSE FOG AROUND THE
PERIPHERY OF LAKE SUPERIOR THIS MORNING. THE COMBINATION OF A
MOISTURE SFC LAYER...CONTINUOUS INFLUX OF COOL MOIST AIR FROM THE
EAST...AND A STRONG INVERSION AT THE TOP OF THE BOUNDARY LAYER ARE
ALL AIDING IN THE FORMATION AND PERSISTENCE OF FOG AROUND THE
NORTHLAND. WILL LIKELY SEE THE FOG CONTINUE TODAY AS LONG AS THE
WINDS REMAIN FROM THE EAST OFF THE LAKE. THE APPROACHING SFC
TROUGH SHOULD WIN OUT AND ALLOW WINDS TO VEER TO THE S/SW...WHICH
WILL HELP MIX DOWN SOME DRIER AIR ALOFT AND ERODE THE FOG LAYER BY
LATE MORNING. USUALLY TAKES LONGER THAN EXPECTED...SO MAY NEED TO
EXTEND DENSE FOG ADVISORY LONGER THAN 10AM. HOWEVER...FOR NOW WILL
KEEP WITH 10AM AS THE ENDING TIME.
THE DURATION OF THE EAST WINDS AND CLOUD LAYER WILL ALSO MITIGATE
HOW WARM TEMPERATURES GET TODAY. WITH CLOUD COVER EXPECTED THROUGH
A GOOD PORTION OF THE DAY...DECIDED TO DROP MAX TEMPS
TODAY...MAINLY IN NW WI. KEPT WITH 60S FOR INLAND LOCATIONS OF NE
MN...AND 40S AND 50S AROUND THE LAKE. TEMPS COOL INTO THE 30S AND
40S TONIGHT...AND WARM BACK INTO THE 60S AND LOWER 70S INLAND ON
SUNDAY...WITH 50S AROUND THE LAKE AS EAST WINDS RETURN. RIDGE OF
HIGH PRESSURE BUILDS IN ACROSS THE NRN PLAINS SUNDAY AS THE NEXT
SYSTEM PREPARES TO MOVE IN FROM THE SW SUNDAY NIGHT.
LONG TERM...
SUNDAY NIGHT THROUGH FRIDAY...
MODEL DIFFERENCES WITH THE MAGNITUDE OF THE FLATTENING/MOVING OF
THE UPPER RIDGE AND THE APPROACHING CLOSED UPPER LOW MOVING
THROUGH CANADA SUNDAY NIGHT. THIS ALSO PLAYS A ROLE IN THE AMOUNT
OF INSTABILITY FOR THUNDERSTORM DEVELOPMENT. USED A BLEND OF
QPF/POPS WITH THE MAJORITY OF THE THUNDERSTORMS HOLDING OFF UNTIL
AFTER 06Z MONDAY. THIS IS WHEN THETAE ADVECTION IS GREATEST. MODEL
DIFFERENCES CONTINUE ON MONDAY AS THE GFS IS QUICK TO MOVE A FRONT
THROUGH THE FA WHILE THE ECMWF/GEM/UKMET ARE THE SLOWEST. HAVE
SIDED WITH THE SLOWER APPROACH WHICH KEEPS THE INSTABILITY AXIS
NEARBY AND THE MENTION OF THUNDERSTORMS NEEDED. CONTINUED WITH THE
SLOWER MODELS MONDAY NIGHT AND LINGERED THE POPS. AN UPPER LEVEL
TROF MOVES THROUGH THE FA TUESDAY PUSHING THE PCPN E ALLOWING SFC
RIDGING TO BUILD IN. THE SFC HIGH BECOMES ANCHORED OVER THE
EASTERN GREAT LAKES TUESDAY NIGHT THROUGH FRIDAY KEEPING THE AREA
IN AN EASTERLY FLOW AND NO PCPN WITH THE DRY AIR FROM THE HIGH
LOCKED INTO THE FA.
AVIATION...06Z TAFS...
SKIES HAD CLEARED OVER KBRD...BUT MVFR CEILINGS HAVE ALREADY MOVED
BACK IN. IFR OR LOW MVFR CONDITIONS WILL PERSIST TONIGHT...WITH SOME
MIXED PRECIPITATION ACROSS THE FAR NORTH. DENSE FOG CAN BE
EXPECTED AROUND LAKE SUPERIOR. LATEST MODEL RUNS SUGGEST THE LOW
CEILINGS WILL BE SLOWER TO CLEAR ON SATURDAY...AND WE DELAYED THE
TIMING BY 1 TO 3 HOURS IN THE 06Z TAFS.
A SHORTWAVE AND TROUGH WILL ALSO BRING A CHANCE FOR SHOWERS
THROUGH SATURDAY...WITH THE BEST CHANCE ACROSS THE FAR NORTHEAST.
&&
.POINT TEMPS/POPS...
DLH 57 38 56 40 / 20 10 10 40
INL 60 33 60 40 / 30 10 10 30
BRD 66 43 72 51 / 10 10 10 20
HYR 58 40 68 47 / 10 10 10 30
ASX 56 39 57 43 / 10 10 10 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ020-021-
037.
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ001.
LS...NONE.
&&
$$
SHORT TERM...TENTINGER
LONG TERM....GSF
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS DULUTH MN
331 AM CDT SAT MAR 31 2012
.SHORT TERM...
TODAY THROUGH SUNDAY AFTERNOON...
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE PATCHY FOG
THROUGHOUT THE NORTHLAND WITH DENSE FOG ALONG THE NORTH SHORE AND
AROUND THE TWIN PORTS THIS MORNING...ALONG WITH RAIN SHOWERS MOVING
IN FROM THE NW TODAY...WITH PATCHY FREEZING DRIZZLE POSSIBLE IN THE
TIP OF THE ARROWHEAD BEFORE TEMPERATURES WARM LATE THIS MORNING.
UPPER LEVEL FLOW WILL REMAIN QUASI-ZONAL ACROSS MUCH OF THE CONUS
TODAY...BUT BECOME AMPLIFIED ON SUNDAY AS AN UPPER TROUGH DIGS
INTO THE WRN U.S. A WEAK 500MB S/W AND ASSOCIATED SFC TROUGH OVER
THE WRN DAKOTAS/SRN SASKATCHEWAN/MANITOBA REGION WILL TRACK TO THE
EAST THIS MORNING INTO WRN ONTARIO/NRN MN. RAIN SHOWERS WILL
ACCOMPANY THIS SYSTEM...MAINLY ACROSS THE NRN COUNTIES OF THE
FORECAST AREA. A FEW SHOWERS AND STORMS ARE ONGOING THIS MORNING
AROUND WINNIPEG...ALONG THE NRN EDGE OF A WARM/MOIST/UNSTABLE AIR
MASS BEING ADVECTED IN FROM THE SOUTH AND CO-LOCATED WITH A
NARROW BAND OF LOW LEVEL F-GEN. THIS PRECIP WILL TRY TO MOVE INTO
NE MN THIS MORNING...BUT WILL ENCOUNTER A MORE STABLE AIR MASS AND
DIMINISH IN INTENSITY THROUGH MID MORNING. THE OTHER CONCERN WITH
THIS PRECIP BAND WILL BE THE POTENTIAL FOR FREEZING DRIZZLE INTO
MAINLY LAKE AND COOK COUNTIES BEFORE 10AM. AS THE SURGE OF WARM
AIR ALOFT MOVES EWD OVER THE NEAR FREEZING SFC LAYER IN NE MN...THE
CHC FOR FREEZING PRECIP INCREASES. RUC SOUNDINGS AT ELY PRODUCE A
SATURATED THERMAL PROFILE NEAR FREEZING UP THROUGH 3000 FT...WITH
A VERY DRY LAYER ALOFT. SFC WINDS WILL EVENTUALLY VEER TO THE S/SW
AND USHER IN WARMER AIR FROM THE SOUTH BY LATE MORNING
TODAY...WHICH WILL ALLOW ANY PRECIP TO BECOME ALL LIQUID. LIQUID
PRECIP AMTS WILL RANGE FROM A TRACE UP TO A COUPLE TENTHS OF AN
INCH.
THE OTHER CONCERN IN THE SHORT TERM IS THE DENSE FOG AROUND THE
PERIPHERY OF LAKE SUPERIOR THIS MORNING. THE COMBINATION OF A
MOISTURE SFC LAYER...CONTINUOUS INFLUX OF COOL MOIST AIR FROM THE
EAST...AND A STRONG INVERSION AT THE TOP OF THE BOUNDARY LAYER ARE
ALL AIDING IN THE FORMATION AND PERSISTENCE OF FOG AROUND THE
NORTHLAND. WILL LIKELY SEE THE FOG CONTINUE TODAY AS LONG AS THE
WINDS REMAIN FROM THE EAST OFF THE LAKE. THE APPROACHING SFC
TROUGH SHOULD WIN OUT AND ALLOW WINDS TO VEER TO THE S/SW...WHICH
WILL HELP MIX DOWN SOME DRIER AIR ALOFT AND ERODE THE FOG LAYER BY
LATE MORNING. USUALLY TAKES LONGER THAN EXPECTED...SO MAY NEED TO
EXTEND DENSE FOG ADVISORY LONGER THAN 10AM. HOWEVER...FOR NOW WILL
KEEP WITH 10AM AS THE ENDING TIME.
THE DURATION OF THE EAST WINDS AND CLOUD LAYER WILL ALSO MITIGATE
HOW WARM TEMPERATURES GET TODAY. WITH CLOUD COVER EXPECTED THROUGH
A GOOD PORTION OF THE DAY...DECIDED TO DROP MAX TEMPS
TODAY...MAINLY IN NW WI. KEPT WITH 60S FOR INLAND LOCATIONS OF NE
MN...AND 40S AND 50S AROUND THE LAKE. TEMPS COOL INTO THE 30S AND
40S TONIGHT...AND WARM BACK INTO THE 60S AND LOWER 70S INLAND ON
SUNDAY...WITH 50S AROUND THE LAKE AS EAST WINDS RETURN. RIDGE OF
HIGH PRESSURE BUILDS IN ACROSS THE NRN PLAINS SUNDAY AS THE NEXT
SYSTEM PREPARES TO MOVE IN FROM THE SW SUNDAY NIGHT.
.LONG TERM...
SUNDAY NIGHT THROUGH FRIDAY...
MODEL DIFFERENCES WITH THE MAGNITUDE OF THE FLATTENING/MOVING OF
THE UPPER RIDGE AND THE APPROACHING CLOSED UPPER LOW MOVING
THROUGH CANADA SUNDAY NIGHT. THIS ALSO PLAYS A ROLE IN THE AMOUNT
OF INSTABILITY FOR THUNDERSTORM DEVELOPMENT. USED A BLEND OF
QPF/POPS WITH THE MAJORITY OF THE THUNDERSTORMS HOLDING OFF UNTIL
AFTER 06Z MONDAY. THIS IS WHEN THETAE ADVECTION IS GREATEST. MODEL
DIFFERENCES CONTINUE ON MONDAY AS THE GFS IS QUICK TO MOVE A FRONT
THROUGH THE FA WHILE THE ECMWF/GEM/UKMET ARE THE SLOWEST. HAVE
SIDED WITH THE SLOWER APPROACH WHICH KEEPS THE INSTABILITY AXIS
NEARBY AND THE MENTION OF THUNDERSTORMS NEEDED. CONTINUED WITH THE
SLOWER MODELS MONDAY NIGHT AND LINGERED THE POPS. AN UPPER LEVEL
TROF MOVES THROUGH THE FA TUESDAY PUSHING THE PCPN E ALLOWING SFC
RIDGING TO BUILD IN. THE SFC HIGH BECOMES ANCHORED OVER THE
EASTERN GREAT LAKES TUESDAY NIGHT THROUGH FRIDAY KEEPING THE AREA
IN AN EASTERLY FLOW AND NO PCPN WITH THE DRY AIR FROM THE HIGH
LOCKED INTO THE FA.
&&
.AVIATION...06Z TAFS...
SKIES HAD CLEARED OVER KBRD...BUT MVFR CEILINGS HAVE ALREADY MOVED
BACK IN. IFR OR LOW MVFR CONDITIONS WILL PERSIST TONIGHT...WITH SOME
MIXED PRECIPITATION ACROSS THE FAR NORTH. DENSE FOG CAN BE
EXPECTED AROUND LAKE SUPERIOR. LATEST MODEL RUNS SUGGEST THE LOW
CEILINGS WILL BE SLOWER TO CLEAR ON SATURDAY...AND WE DELAYED THE
TIMING BY 1 TO 3 HOURS IN THE 06Z TAFS.
A SHORTWAVE AND TROUGH WILL ALSO BRING A CHANCE FOR SHOWERS
THROUGH SATURDAY...WITH THE BEST CHANCE ACROSS THE FAR NORTHEAST.
&&
.POINT TEMPS/POPS...
DLH 57 38 56 40 / 20 10 10 40
INL 60 33 60 40 / 30 10 10 30
BRD 66 43 72 51 / 10 10 10 20
HYR 58 40 68 47 / 10 10 10 30
ASX 56 39 57 43 / 10 10 10 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ020-021-
037.
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ001.
LS...NONE.
&&
$$
SHORT TERM...TENTINGER
LONG TERM....GSF
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS JACKSON MS
1027 AM CDT SAT MAR 31 2012
.UPDATE...
OVERALL...HAVE MADE NO ADJUSTMENTS TO THE FORECAST FOR LATER TODAY
INTO THIS EVENING...BUT THERE ARE STILL MANY UNCERTAINTIES REGARDING
THE EXPECTED CONVECTIVE SCENARIO. IN TERMS OF ATMOSPHERIC MASS
CONTINUITY...THE ARKLAMISS CURRENTLY RESIDES IN SOMEWHAT OF A
"SINKHOLE" AS AN MCV CONTINUES TO MOVE EAST OF THE AREA ALONG THE FL
PANHANDLE REGION WHILE A COLD FRONT REMAINS WELL TO OUR NORTH ACROSS
THE MID MS/LOWER OH VALLEY REGION. IN ADDITION...A WEAK UPPER LEVEL
TROUGH OVER THE OZARK/ARKLATEX REGION IS ASSOCIATED WITH WANING TSTM
ACTIVITY.
SO DIVERGENT LOWER LEVELS ARE MAKING FOR A RATHER HOMOGENEOUS
AIRMASS OVER THE ARKLAMISS WITH NO REALLY DISTINGUISHABLE SFC
FEATURES. THE ONE EXCEPTION TO THIS MAY BE DUE TO A LINGERING STRATUS
DECK ALONG THE I-20 CORRIDOR TRAPPED BENEATH A STOUT MID LEVEL
INVERSION AND WEAK DEEP LAYER FLOW. THIS MOISTURE IS SLOW TO MIX OUT
AND IS CREATING DIFFERENTIAL BOUNDARIES TO THE NORTH AND SOUTH...BUT
EXPECT STRATUS TO MIX OUT WITH CONTINUED HEATING ALLOWING ANY
BOUNDARIES TO WASH OUT.
GIVEN THE LACK OF FOCUSING MECHANISMS...THE LATEST MODEL GUIDANCE IS
STRUGGLING TO DEVELOP MUCH CONVECTIVE PRECIPITATION OVER THE AREA
LATER THIS AFTERNOON/EVNG. THE HRRR DEVELOPS DISORGANIZED DIURNAL
SHOWER/ISO TSTMS OVER CNTRL/ERN MS BETWEEN 17-20Z AND THIS WILL BE
THE BASIS FOR KEEPING CURRENT TSTM CHANCES IN GRIDS...BUT OTHERWISE
THE ONLY CONVECTION IT DEVELOPS IS AHEAD OF THE COLD FRONT TO OUR
NORTH WHICH IS NOT FORECAST TO REACH THE ARKLAMISS. WILL CONTINUE TO
MONITOR THE TRENDS FOR THE POTENTIAL OF STRONG/SVR TSTMS. AM
RELUCTANT TO MAKE ANY CHANGES AT THIS POINT GIVEN INCREDIBLY STEEP
MID LEVEL LAPSE RATES (CURRENT 700-500MB ~8.0 DEG C/KM) AND
DECREASING CONVECTIVE INHIBITION WITH CONTINUED HEATING. THE
CONDITIONAL RISK FOR SEVERE HAIL SHOULD VIGOROUS CONVECTIVE
DEVELOPMENT TAKE PLACE IN A FASHION SIMILAR TO RECENT RUNS OF THE
HIGH-RES WRF WARRANTS KEEPING THE HAZARDOUS WEATHER PRODUCTS AS
THEY ARE FOR NOW. /EC/
.PREV DISCUSSION... /ISSUED 420 AM CDT SAT MAR 31 2012/
DISCUSSION...SHORT TERM(TODAY THROUGH SUNDAY NIGHT)
A FRONTAL BOUNDARY DROPPING SWD THROUGH THE OH VALLEY EXTENDED INTO
THE OZARKS AND SHOULD CROSS THE I-40 CORRIDOR ABOUT MIDDAY TODAY.
EXPECT SKIES IN OUR AREA TO BECOME PARTLY CLOUDY IN THE WAKE OF THE
COASTAL DISTURBANCE WITH RAPID DESTABILIZATION THIS AFTERNOON. NAM12
PROGS POCKETS OF MLCAPES REACHING 3000J/KG ALONG THE HIGHWAY 82
CORRIDOR IN CONJUNCTION WITH 7-500MB LAPSE RATES OF NEARLY 8.5C.
MEANWHILE...A WELL-DEFINED 300MB SHORTWAVE IN THE MO VALLEY EXPECTED
TO CROSS THE MID SOUTH THIS AFTERNOON HELPING TO SET OFF THE STRONG
TO SEVERE ROUND OF STORMS FOR ROUGHLY OUR N AND E CWFA PORTIONS
BETWEEN 2PM AND 9PM. THE STORMS SHOULD DRIFT SEWD ONCE THEY FORM BUT
RATHER WEAK LOW- MID LEVEL SHEAR WILL LIMIT THE PEAK STORM INTENSITY
TO MAINLY HAIL UP TO HALF-DOLLAR SIZE AND DAMAGING WIND GUSTS OF 50
TO 60 MPH.
ONCE THE TROUGH AXIS PASSES THE AREA 00-03Z THIS EVENING...RAIN
CHANCES WILL WANE THROUGH THE NIGHT TIME EXCEPT FOR SOME LINGERING
SHRA CHANCES IN ERN MS. EXPECT PATCHY FOG AGAIN LATE TONIGHT...
ESPECIALLY WHERE ANY RAINFALL OCCURS.
ON SUNDAY...MID LEVEL SUBSIDENCE RIDGE BUILDING WITH DRY AIR MIXING
TO THE SURFACE IN THE AFTERNOON. AN ISOLATED STORM APPEARS EVEN LESS
LIKELY AS PWATS DIP BELOW 1 INCH AND WILL KEEP POPS AT 5 PERCENT FOR
NOW. HOT AFTERNOON TEMPS WOULD SEEM TO BE THE MAIN FEATURE AS HIGHS
PUSH 85-90F WITH EXPECTED NEAR TOTAL SUNSHINE ONCE EARLY MORNING FOG
BURNS OFF. THE RIDGE HOLDS THROUGH SUNDAY NIGHT WITH TEMPS SAGGING
BACK INTO THE LOWER 60S AT MOST LOCATIONS. LOOK FOR AN EVEN NARROWER
WINDOW FOR ANY LATE NIGHT PATCHY FOG DEVELOPMENT. /40/
LONG TERM...MONDAY THROUGH NEXT SATURDAY
OVERALL MODEL ENVELOPE SLOWS THROUGH THE PERIOD WITH SOMEWHAT BETTER
AGREEMENT INITIALLY ON MON BUT DIVERGES BY WED/THU TIME FRAME. THIS
HAS RESULTED SOME DECENT POP/TEMP CHANGES THROUGH THE PERIOD. IN
ADDITION...THE QUESTION OF `WHEN` THE FRONTAL PASSAGE WILL OCCUR HAS
CHANGED TO `IF` A FRONTAL PASSAGE WILL OCCUR IN THE MID TO LATE-WEEK
TIME-FRAME.
HAVE FAVORED A BLEND OF THE GEM/GFS ENSEMBLE/DGEX WITH SOME
WEIGHTING TO THE 00Z OPS GFS WHILE DISCOUNTING THE 12Z/00Z EC. THE
GEM/GFSENS (INCLUDING INDIVIDUAL MEMBERS)/DGEX FAVOR A SLIGHTLY MORE
PROGRESSIVE...YET SLOWER TIMING WISE FROM PREVIOUS RUNS...TRACK OF
THE SRN-STREAM H5 CUT-OFF LOW TUES-THURS WHILE THE EC REMAINS THE
SLOWEST AND DEEPER SYSTEM THRU MID-WEEK. OF NOTE...THE 00Z EC DID
TREND FASTER THAN ITS 12Z COUNTERPART...FURTHER SUPPORTING THE
FASTER NWP ENVELOPE.
OVERALL SYNOPTIC PATTERN MONDAY WILL FEATURE DECENTLY-AMPLIFIED
LONGWAVE TROUGH IN THE TRANSITION OF CUTTING OFF OVER NEW MEXICO
WITH H5 RIDGING OVER LOWER TO MID-MS VALLEY. SOME SMALLER S/WV
TROUGHS WILL BE EMBEDDED IN THE SW FLOW FROM THE SABINE TO LOWER-MS
VALLEYS. THE IN SITU AIRMASS WILL BE BORDERLINE HOT AND MOIST WITH
AFTN TEMPS IN THE M/U80S AND DEWPOINTS IN THE L60S. A FEW STRONG TO
SEVERE PULSE TO MULTI-CLUSTER TSTORMS COULD BE POSSIBLE ACROSS SOUTH
AND WEST AREAS MON AFTN GIVEN NEAR 2.5-3.5K J/KG MUCAPE...L30
VT`S...AND S/WV`S PROGGED TO EJECT AHEAD OF PARENT CUT-OFF LOW. MAIN
SEVERE RISK WILL BE HAIL AND GUSTY WINDS TO 60 MPH. ROBUST TSTORMS
SHOULD DIMINISH SLOWLY AFTER SUNSET BUT ISO/SCT SHOWER ACTIVITY
COULD CONTINUE THROUGH MUCH OF THE OVERNIGHT INTO TUES.
FOR TUES...CNTRL AND WEST AREAS WILL HAVE BEST CHANCES FOR PULSE
RAIN/TSTORMS WITH CONTINUED S/WV AND INSTABILITY INFLUENCE AS THE
NOW COMPLETELY CUT-OFF LOW TRANSITS ACROSS SRN PLAINS. THIS WILL
HELP FEED ~1.6 IN PWATS NRD ACROSS ARKLAMISS REGION AHEAD OF SLOWLY
APPROACHING COLD FRONT STILL IN EAST TX.
DUE TO SLOWER OVERALL EVOLUTION...(WHILE BEING ON THE MORE
PROGRESSIVE ENVELOPE) WED POPS WERE INCREASED SUBSTANTIALLY AS
DEEP-LYR WIND SHEAR INCREASES OVERTOP UNSTABLE SECTOR AS THE COLD
FRONT APPROACHES WRN ARKLAMISS REGIONS BY LATE WED. THE BEST LIFT
APPEARS NOW TO BE DISPLACED FARTHER NORTH WITH OVERALL REDUCTION IN
SEVERE POTENTIAL FROM CURRENT ADVERTISED HWO/GRAPHICS WITH
ADJUSTMENTS FORTH-COMING. HOWEVER...DECENT COVERAGE OF
SHOWER/TSTORMS WILL BE LIKELY GIVEN FAVORABLE ENVIRONMENTAL
CONDITIONS.
AS POSED EARLIER...BY THURSDAY...THE QUESTION BECOMES IF THE FRONT
WILL BE ABLE TO MAKE IT THROUGH THE REGION OPPOSED TO THE PREVIOUS
NEAR CERTAINTY. 00Z OPS GFS SHOWS SFC FRONT STALING NW OF REGION BUT
ELEVATED DEWPOINT BOUNDARY APPEARS TO MAKE IT THROUGH. THE 00Z EC
BEING DEEPER...INDICATES SFC FRONT WILL MAKE IT THROUGH COMPLETELY.
THUR COULD HAVE THE LEAST RAIN COVERAGE WITH LOW-LVLS MINUS NEAR SFC
BL TO DRY TO SUPPORT DEEPER SHOWER DEVELOPMENT. FOR FRI-SAT
TIME-FRAME...BL APPEARS TO RECOVER POSSIBLY ALLOWING FOR MORE
SHOWER/TSTORM ACTIVITY UNDER WEAK H7-H5 RIDGING. /ALLEN/
&&
.AVIATION...FOG AND LOW STRATUS WILL CONTINUE TO LIFT THIS MORNING
WITH PATCHES OF IFR/LIFR CIGS/VSBY POSSIBLE THROUGH 16Z. VFR
SCATTERED CLOUDS ARE EXPECTED AFTER 16Z. SCT SHWRS/TSTMS WILL BE
POSSIBLE OVER NORTH/EAST PORTIONS OF THE AREA AFTER 19Z WITH
ISOLATED COVERAGE POSSIBLE OVER THE REMAINDER OF THE AREA. AN UPPER
LEVEL DISTURBANCE MOVING SEWD FROM THE OZARKS SHOULD CONCENTRATE THE
MOST INTENSE STORMS N OF HIGHWAY 82 AS A COLD FRONT APPROACHES THE
AREA FROM THE TN VALLEY 22-02Z. CONDITIONS EXPECTED TO REMAIN VFR
EARLY TONIGHT BEFORE PATCHY MVFR FOG DEVELOPS AFTER 07Z.
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1019 AM MDT SAT MAR 31 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY...
UPDATE...ISOLATED SHOWERS BEGINNING TO TAKE SHAPE ACROSS CENTRAL
MONTANA...AND ARE TRACKING TOWARD THE NORTHEAST. THE HRRR AND NAM
BUFFER SOUNDINGS ARE HINTING AT ISOLATED SHOWERS IMPACTING AREAS
SOUTH OF THE MISSOURI RIVER THIS AFTERNOON. BUT WITH SUCH DRY LOW
LEVELS ONLY SPRINKLES ARE POSSIBLE...THUS UPDATED TO PUT IN
MENTION OF SPRINKLES ACROSS THE SOUTHEAST. OTHERWISE LOOKS LIKE A HOT DAY
ACROSS NORTHEAST MONTANA. GILCHRIST
PREVIOUS DISCUSSION...SEMI PERSISTENT PATTERN WITH WEST COAST
TROF AND CENTRAL STATES RIDGE CONTINUES ALTHOUGH SHORTWAVE WILL BE
PUSHING THROUGH THE GREAT BASIN THIS WEEKEND.
TROF DIGGING ALONG THE WEST COAST...AMPLIFYING THE RIDGE OVER THE
PLAINS... AND PUSHING WARM AIR NORTHWARD. RESULT IS ANOTHER DAY
WITH TEMPERATURES APPROACHING RECORD LEVELS OVER EASTERN MONTANA.
WEAK HIGH PRESSURE SLIDING INTO NORTH DAKOTA AND LEE TROF
DEVELOPING IN CENTRAL MONTANA WILL TURN WINDS TO THE SOUTH TODAY.
DEEP MIXING IN THE WARM AIR MAY RESULT IN OCCASIONAL GUSTY WINDS
BUT WEAK WARM AIR ADVECTION AND LIFT NOT TOO FAVORABLE.
SHORTWAVE LIFTING TOWARD THE STATE TONIGHT WILL DEVELOP A
SURFACE LOW ALONG THE BOUNDARY IN CENTRAL MONTANA...PUSHING IT
EAST OVERNIGHT. THUNDERSTORMS POSSIBLE OVER CENTRAL MONTANA DURING
THE EVENING...TRANSITIONING TO SHOWERS OVERNIGHT AS THE LOW LIFTS
NORTHEAST.
WINDS INCREASE BEHIND THE SYSTEM ON SUNDAY...WITH COLD AIR
ADVECTION HELPING TO PUSH THEM TO THE SURFACE. CAA WILL ALSO DROP
TEMPERATURES ABOUT 10 DEGREES. COOLER WEATHER CONTINUES INTO
MONDAY AS UPPER TROF MOVES ACROSS THE STATE. TROF SPLITS FORMING
CUT OFF LOW OVER THE FOUR CORNERS...WHICH WILL KEEP MUCH MOISTURE
FROM SPREADING NORTHWARD. THUS CHANCES FOR SIGNIFICANT
PRECIPITATION VERY LOW INTO EARLY NEXT WEEK. EBERT
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
ANOTHER WARM AND DRY UPPER RIDGE GIVING ABOVE NORMAL TEMPS FOR
TUE/WED. 850 MB TEMPS CLIMB TO AS HIGH AS 16C WED...THUS MORE 70S
FOR HIGHS.
THEN AN APPARENT LARGE SCALE PATTERN CHANGE TAKES PLACE AS A
SIGNIFICANT PART OF THE LARGE LOW IN THE E PACIFIC STARTS TO PUSH
E INTO THE INLAND WESTERN STATES. MODELS IN GOOD AGREEMENT UP TO
THIS POINT WITH THE PATTERN...AND THE LEADING COLD FRONT THAT
MOVES ACROSS OUR AREA THU. THIS FRONT USHERS IN A CHANGE TO COOLER
AND MORE UNSETTLED WEATHER...AT LEAST THRU SATURDAY...ASSOCIATED
WITH THE LOW PRESSURE TROUGH ALOFT THAT SEEMS TO STALL OVER THE
WESTERN STATES.
MODELS HAVE QUITE A BIT OF OUR AREA BELOW 0C AT 850 MB LATE IN THE PERIOD
...SO IT APPEARS THAT A LITTLE LATE NIGHT/EARLY MORN SNOW IS POSSIBLE.
SOME MODEL RUNS...ESPECIALLY THE ECMWF...HAVE ALSO BEEN SHOWING
THAT A SIGNIFICANT SURFACE WAVE MAY FORM ON THE FRONT OVER WY AND
MOVE NE INTO OUR AREA...AND OTHER MODELS HAVE HINTED AT THIS
TOO...BUT A LOT OF VARIATION ON WHETHER THIS WILL EVEN DEVELOP AT
ALL THOUGH...AS WELL AS LOCATION AFFECTED AND TIMING. AN OUTSIDE
CHANCE THIS COULD BRING A SIGNIFICANT RAIN/SNOW EVENT FRI OR SAT.
SINCE THIS IS QUITE A WAYS OFF WITH LOTS OF MODEL VARIATION...WILL
STICK WITH JUST SLIGHT CHANCE POPS FOR EACH PERIOD THU NIGHT AND
BEYOND UNTIL THIS BECOMES MORE OBVIOUS. SIMONSEN
&&
.AVIATION...
VFR WITH SCATTERED TO BROKEN LAYERS BETWEEN 7 AND 12K FT AGL TODAY
AND TONIGHT. ISOLATED SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE
AS WELL LATE THIS AFTERNOON OR EVENING ACROSS THE KGGW AND KOLF
TERMINALS. RSMITH
&&
.FIRE WEATHER...
DRY AND WARMER THAN NORMAL CONDITIONS CONTINUE ACROSS NORTHEAST
MONTANA TODAY. RELATIVE HUMIDITY EXPECTED TO DROP TO AROUND 20
PERCENT THIS AFTERNOON...AND ALTHOUGH WINDS WILL NOT BE AS STRONG
AS YESTERDAY...STILL COULD GET 10-20 MPH WITH HIGHER GUSTS ACROSS
THE WESTERN ZONES. THUNDERSTORMS ARE ALSO POSSIBLE IN CENTRAL
MONTANA BY LATE AFTERNOON...SPREADING EAST INTO THE EVENING...AS A
COLD FRONT APPROACHES THE REGION. ISSUED RED FLAG WARNING FOR THE
WESTERN ZONES DUE TO THE COMBINATION OF DRY FUELS...LOW RH...GUSTY
WINDS AND THUNDERSTORMS.
THIS FRONT WILL CROSS EASTERN MONTANA TONIGHT. SLIGHTLY COOLER
BUT WINDIER CONDITIONS ARE EXPECTED ON SUNDAY. RH WILL BE
IMPROVING WITH THE COOLER WEATHER...AND SHOWERS ARE POSSIBLE
BEHIND THE FRONT...SO WIDESPREAD CRITICAL FIRE CONDITIONS NOT
ANTICIPATED. EXCEPTION MAY BE ZONE 122 WHERE WARMER AND DRIER AIR
WILL PERSIST AND SHOWER POTENTIAL IS LESS.
&&
.HYDROLOGY...
THE YELLOWSTONE RIVER WILL BE RISING OVER THE NEXT COUPLE OF DAYS
THEN CRESTING AGAIN LATER IN THE WEEK. A MENTION IN THE HWO WILL
SUFFICE FOR NOW AS CRESTS WILL REMAIN BELOW FLOOD STAGE. JAMBA
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 10 PM MDT THIS
EVENING FOR MTZ134>137.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1239 PM CDT SAT MAR 31 2012
.AVIATION...VFR CONDITIONS ARE EXPECTED THROUGHOUT THE TAF PERIOD.
BOUNDARY LAYER MIXING WILL HELP INCREASE WIND SPEEDS TODAY TO NEAR
15 KTS WITH WIND GUSTS UP TO 20 KTS POSSIBLE. WHILE WINDS WILL
DECREASE SLIGHTLY OVERNIGHT...MIXING DURING THE DAY ON SUNDAY
WILL INCREASE WINDS AGAIN. A LOW PRESSURE SYSTEM WILL ALSO BEGIN
TO KNOCK ON OUR FRONT DOOR FROM THE WEST TOMORROW EVENING WITH A
STRONG PRESSURE GRADIENT ACROSS THE PLAINS JUST BEYOND THE TAF
PERIOD...SUGGESTING GUSTY WINDS DURING THE AFTERNOON TOMORROW. A
FEW HIGH CLOUDS WILL REMAIN THROUGHOUT THE PERIOD...WHILE A FEW
CUMULUS ARE POSSIBLE DURING THE AFTERNOON HOURS.
&&
PREV DISCUSSION... /ISSUED 330 AM CDT SAT MAR 31 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. THE PATTERN ALOFT
FEATURED SUBTLE RIDGING ACROSS THE CENTRAL PLAINS AND RIDGE IS
FORECAST TO EXPAND/BUILD THIS WEEKEND AS PACIFIC TROUGH REACHES THE
WESTERN CONUS. THIS WILL ALLOW A VERY WARM AIRMASS...ON THE ORDER
OF +3.3 STANDARD DEVIATIONS FOR H85 TEMPS...TO SETTLE ACROSS THE
CENTRAL PLAINS...AND FORECAST SOUNDINGS SUGGEST MIXING WILL BE
EVEN HIGHER THAN THIS LEVEL. RIDGE AXIS WILL SHIFT EASTWARD ON
SUNDAY AS UPPER TROUGH MOVES INTO THE ROCKIES WITH FLOW ALOFT
TRANSITIONING SOUTHWESTERLY. THE UPPER LOW IS FORECAST TO EMERGE
ONTO THE PLAINS MONDAY/MONDAY ALTHOUGH MODELS ARE NOT CONSISTENT
ON THE TRACK OF SYSTEM ATTM AND FOLLOWED CLOSER TO ENSEMBLES FOR
NOW.
HEADING INTO TODAY...MODELS HINT AT AN OUTSIDE CHCS FOR SOME LIGHT
CONVECTION PRIOR TO DAYBREAK IN PRESENCE OF SOME MID LEVEL WAA
ACROSS OUR NORTHERN COUNTIES. WILL MONITOR TRENDS OF THIS FOR THE
NEXT SEVERAL HOURS. THIS MORNING INTO EARLY AFTN A WEAK SURFACE
TROUGH WILL SLIDE EAST ACROSS NEBRASKA SHIFTING WINDS WESTERLY CAUSING
MOISTURE AXIS TO SHIFT EASTWARD. MODEL FORECAST SOUNDINGS SUGGEST
MIXING THIS AFTN AROUND H75 WITH WINDS AT THE TOP OF THE LAYER
ROUGHLY BETWEEN 11KTS AND 20KTS ACROSS OUR WESTERN CWA WHILE RH
VALUES DROP NEAR TO BELOW 20 PERCENT GENERALLY WEST OF HIGHWAY
281. LOCATIONS FROM ROUGHLY ORD TO LEXINGTON TO ARAPAHOE LOOK LIKE
THEY WILL MEET THE LOW RH CRITERIA FOR 3HRS WITH MAIN QUESTION
BEING WILL WINDS BE GUSTY ENOUGH FOR FIRE WEATHER HEADLINE.
SURFACE GRADIENT RELAXES SOME IN OUR WEST FOLLOWING BOUNDARY AND
MODELS SUGGEST SFC DPS MAY ACTUALLY RISE SOME IN AFTN AS WEST
WINDS TURN MORE SOUTHWESTERLY. FIRE WEATHER HEADLINE IS NOT A SLAM
DUNK DUE TO UNCERTAINTY IN WIND SPEEDS. HRRR WIND GUSTS DECREASE
ACROSS OUR WEST THIS AFTN AND THIS IS SUPPORTED BY 06Z NAM
SOUNDINGS WHERE WINDS AT THE TOP OF THE MIXED LAYER DECREASE
BETWEEN 21Z AND 00Z. GIVEN THE DECREASING WIND TREND WILL NOT GO
WITH HEADLINE ATTM AS OUR STRONGER WINDS WILL RESIDE EAST OF OUR
LOW RH AREA. THAT BEING SAID...DAY SHIFT WILL NEED TO CLOSELY
MONITOR FOR RED FLAG CONDITIONS.
HIGH TEMPERATURES THIS AFTERNOON LOOK TO BE NEAR OR AT RECORD
BREAKING LEVELS. RECORD FOR GRAND ISLAND TODAY IS 90F SET IN 1978.
RECORD FOR HASTINGS IS 89F SET IN 1946 AND RECORD FOR KEARNEY IS
88F SET IN 1946. CURRENT FORECAST HAS MAX TEMPS RIGHT AROUND THESE
RECORD READINGS AND MARCH WILL DEFINITELY END ON A HOT NOTE.
OVERNIGHT...THE SURFACE TROUGH DEEPENS ALONG THE HIGH PLAINS AND
MOISTURE MAKES A BETTER SURGE NORTH THRU KS INTO SOUTHERN NEBRASKA.
THE GFS MORE SO THAN THE NAM SUGGESTS POTENTIAL FOR SOME LOW CLOUD
DEVELOPMENT MAINLY ACROSS NC KS AND INCREASED CLOUD COVER AND
INCLUDED SOME PATCHY FOG FOR NOW.
ON SUNDAY...THE SURFACE LOW DEEPENS IN EASTERN COLORADO WITH
SOUTHERLY LLVL FLOW INCREASING ACROSS OUR CWA. MOISTURE AXIS ALIGNS
ACROSS THE EASTERN HALF TO TWO THIRDS OF OUR CWA WITH SFC DPS
PROGGED NEAR 60F IN OUR FAR EAST. THE UNSEASONALLY WARM/HOT AIRMASS
REMAINS IN PLACE ACROSS OUR REGION AND WE WILL SEE ANOTHER DAY OF
HIGHS IN THE UPPER 80S TO NEAR 90F WHICH ARE AGAIN NEAR OR ABOVE
RECORDS FOR THE FIRST OF APRIL. SUNDAY NIGHT...SFC COLD FRONTAL
BOUNDARY IN NW NEBRASKA ADVANCES SOUTHEAST INTO OUR CWA...REACHING
ALL BUT OUR SOUTHEAST ZONES BY MORNING. GFS SUGGESTS PCPN MAY
DEVELOP IN VCNTY OF FRONT MAINLY ACROSS OUR NORTHERN ZONES...HOWEVER
SREF AND OTHER MODELS ARE NOT OVERLY SUPPORTIVE OF THIS ATTM AND
WILL KEEP THINGS DRY FOR THE TIME BEING.
OF BIGGER CONCERN TOWARD DAYBREAK MONDAY AND THROUGH THE DAY ON
MONDAY IS THE INCREASING NORTH WINDS FOLLOWING FROPA. MODELS
INDICATE 6HR PRESSURE RISES BEHIND THE BOUNDARY IN EXCESS OF 10MB TO
OUR WEST ALONG THE HIGH PLAINS AND AROUND 8MB ACROSS OUR CWA MIDDAY
MONDAY. GRADIENT REMAINS TIGHT THROUGH THE DAY AND ALL INDICATIONS
FM MODELS SUGGEST WE WILL AT A MINIMUM REACH WIND ADVISORY CRITERIA
AND PORTIONS OF OUR WEST MAY BE NEAR HIGH WIND WARNING CRITERIA AND
WILL NEED TO MONITOR CLOSELY.
THE UPPER LOW SHIFTS EAST ONTO THE SOUTHERN PLAINS TOWARD THE TX/OK
PANHANDLES MONDAY NIGHT. GFS IS FARTHER NORTH WITH CENTER OF SYSTEM
THAN ECMWF AND HAVE PLAYED MIDDLE GROUND AND FOLLOWED CLOSER TO
ENSEMBLE SOLUTIONS FOR NOW. PCPN CHCS INCREASE MONDAY NIGHT FM
SOUTH TO NORTH IN INCREASING LIFT/DYNAMICS ASSOCIATED WITH UPPER
LOW. HAVE LEFT THUNDER OUT FOR NOW AS BETTER INSTABILITY REMAINS TO
OUR SOUTH BUT THIS MAY NEED TO BE ADJUSTED AS TRACK OF SYSTEM IS
REFINED.
LONG TERM...TUESDAY THROUGH FRIDAY. BIGGEST CONCERN IN THE
EXTENDED LOOKS TO BE THE TRACK OF THE UPPER LOW WHICH IS FORECAST
AFFECT OUR AREA MID WEEK.
LATEST RUN OF THE EXTENDED MODELS STILL SHOWING PLENTY OF
DIFFERENCES ON TRACK OF THE UPPER LOW. OPERATIONAL GFS IS ONE OF
THE QUICKEST SOLUTIONS AS IT TAKES THE 500 MB LOW FROM THE OK
PANHANDLE AT 12Z TUE TO THE SOUTHERN EDGE OF OUR CWA BY 12Z
WED...AND THEN PUSHES IT QUICKLY EAST TO THE NORTHEAST TIP OF
MISSOURI BY 12Z THU. OF COURSE THE PERTURBATION RUNS OF THE GFS HAVE
THE LOW ALL OVER THE PLACE. THE EC IS A LITTLE QUICKER THAN THE
PREVIOUS EC RUN AS IT MOVES THE LOW FROM ERN NEW MEXICO AT 12Z TUES
TO A LITTLE SE OF DDC AT 12Z WED...AND THEN INTO NW ARKANSAS BY 12Z
THU. THE GEM IS SIMILAR IN SPEED WITH THE SYSTEM BUT A LITTLE
FURTHER SOUTH WITH THE TRACK. ALL OF THE MODELS BRING THIS SYSTEM ON
SHORE TODAY AND THEN SPLIT THE ENERGY...TAKING SOME NORTH AND SOME
SOUTH. HOPEFULLY THE PICTURE GETS A LITTLE MORE CLEAR IN THE NEXT 24
HRS AS THE LOW MOVES ONTO THE CONUS. BIGGEST IMPLICATIONS FOR US
WILL BE DURATION OF THE PRECIPITATION. COULD SEE OFF AND ON RAIN
TUESDAY AND WED WITH A NORTHERN TRACK...OR THE NORTHERN PART OF THE
CWA MIGHT MISS OUT IF IT GOES SOUTH. IT DOES APPEAR THAT IT SHOULD
PUSH EAST ON THUR AS NEXT UPSTREAM SYSTEM IS SET TO MOVE INTO THE
WESTERN U.S. WHICH SHOULD KEEP THINGS PROGRESSIVE. INSTABILITY
LOOKS MARGINAL ON TUESDAY SO WILL KEEP THUNDER OUT FOR NOW.
OTHERWISE TEMPERATURES SHOULD STILL BE ABOVE NORMAL WITH HIGHS IN
THE UPPER 50S ON TUESDAY AND THEN CLIMBING BACK TO NEAR 70 FOR
THURSDAY AND FRIDAY. ALSO --- IT STILL DOES NOT LOOK LIKE WE WILL
GET BELOW FREEZING THROUGH THE UPCOMING WORKWEEK.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
614 AM CDT SAT MAR 31 2012
.AVIATION...12Z KGRI TAF. SHOULD SEE VFR CONDITIONS THROUGHOUT THE
FORECAST PERIOD. SOUTHWEST WINDS WILL PICK UP AROUND LUNCHTIME AS
TEMPERATURES QUICKLY RISE AND GOOD MIXING TAKES PLACE. WINDS
ARE NOT OVERLY IMPRESSIVE A FEW THOUSAND FEET UP AND AND WILL KEEP
GUSTS TO AROUND 20 KTS. BY SUNSET...WINDS SHOULD BACK OFF TO NEAR
8-10 KTS. MAY SEE JUST A FEW HIGH BASED CU THIS AFTERNOON ALTHOUGH
CONVECTIVE TEMPS PRETTY HIGH. ALSO JUST A SLIGHT CHANCE OF SOME
FOG LATE IN THE PERIOD BUT WILL LEAVE OUT FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 330 AM CDT SAT MAR 31 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. THE PATTERN ALOFT
FEATURED SUBTLE RIDGING ACROSS THE CENTRAL PLAINS AND RIDGE IS
FORECAST TO EXPAND/BUILD THIS WEEKEND AS PACIFIC TROUGH REACHES THE
WESTERN CONUS. THIS WILL ALLOW A VERY WARM AIRMASS...ON THE ORDER
OF +3.3 STANDARD DEVIATIONS FOR H85 TEMPS...TO SETTLE ACROSS THE
CENTRAL PLAINS...AND FORECAST SOUNDINGS SUGGEST MIXING WILL BE
EVEN HIGHER THAN THIS LEVEL. RIDGE AXIS WILL SHIFT EASTWARD ON
SUNDAY AS UPPER TROUGH MOVES INTO THE ROCKIES WITH FLOW ALOFT
TRANSITIONING SOUTHWESTERLY. THE UPPER LOW IS FORECAST TO EMERGE
ONTO THE PLAINS MONDAY/MONDAY ALTHOUGH MODELS ARE NOT CONSISTENT
ON THE TRACK OF SYSTEM ATTM AND FOLLOWED CLOSER TO ENSEMBLES FOR
NOW.
HEADING INTO TODAY...MODELS HINT AT AN OUTSIDE CHCS FOR SOME LIGHT
CONVECTION PRIOR TO DAYBREAK IN PRESENCE OF SOME MID LEVEL WAA
ACROSS OUR NORTHERN COUNTIES. WILL MONITOR TRENDS OF THIS FOR THE
NEXT SEVERAL HOURS. THIS MORNING INTO EARLY AFTN A WEAK SURFACE
TROUGH WILL SLIDE EAST ACROSS NEBRASKA SHIFTING WINDS WESTERLY CAUSING
MOISTURE AXIS TO SHIFT EASTWARD. MODEL FORECAST SOUNDINGS SUGGEST
MIXING THIS AFTN AROUND H75 WITH WINDS AT THE TOP OF THE LAYER
ROUGHLY BETWEEN 11KTS AND 20KTS ACROSS OUR WESTERN CWA WHILE RH
VALUES DROP NEAR TO BELOW 20 PERCENT GENERALLY WEST OF HIGHWAY
281. LOCATIONS FROM ROUGHLY ORD TO LEXINGTON TO ARAPAHOE LOOK LIKE
THEY WILL MEET THE LOW RH CRITERIA FOR 3HRS WITH MAIN QUESTION
BEING WILL WINDS BE GUSTY ENOUGH FOR FIRE WEATHER HEADLINE.
SURFACE GRADIENT RELAXES SOME IN OUR WEST FOLLOWING BOUNDARY AND
MODELS SUGGEST SFC DPS MAY ACTUALLY RISE SOME IN AFTN AS WEST
WINDS TURN MORE SOUTHWESTERLY. FIRE WEATHER HEADLINE IS NOT A SLAM
DUNK DUE TO UNCERTAINTY IN WIND SPEEDS. HRRR WIND GUSTS DECREASE
ACROSS OUR WEST THIS AFTN AND THIS IS SUPPORTED BY 06Z NAM
SOUNDINGS WHERE WINDS AT THE TOP OF THE MIXED LAYER DECREASE
BETWEEN 21Z AND 00Z. GIVEN THE DECREASING WIND TREND WILL NOT GO
WITH HEADLINE ATTM AS OUR STRONGER WINDS WILL RESIDE EAST OF OUR
LOW RH AREA. THAT BEING SAID...DAY SHIFT WILL NEED TO CLOSELY
MONITOR FOR RED FLAG CONDITIONS.
HIGH TEMPERATURES THIS AFTERNOON LOOK TO BE NEAR OR AT RECORD
BREAKING LEVELS. RECORD FOR GRAND ISLAND TODAY IS 90F SET IN 1978.
RECORD FOR HASTINGS IS 89F SET IN 1946 AND RECORD FOR KEARNEY IS
88F SET IN 1946. CURRENT FORECAST HAS MAX TEMPS RIGHT AROUND THESE
RECORD READINGS AND MARCH WILL DEFINITELY END ON A HOT NOTE.
OVERNIGHT...THE SURFACE TROUGH DEEPENS ALONG THE HIGH PLAINS AND
MOISTURE MAKES A BETTER SURGE NORTH THRU KS INTO SOUTHERN NEBRASKA.
THE GFS MORE SO THAN THE NAM SUGGESTS POTENTIAL FOR SOME LOW CLOUD
DEVELOPMENT MAINLY ACROSS NC KS AND INCREASED CLOUD COVER AND
INCLUDED SOME PATCHY FOG FOR NOW.
ON SUNDAY...THE SURFACE LOW DEEPENS IN EASTERN COLORADO WITH
SOUTHERLY LLVL FLOW INCREASING ACROSS OUR CWA. MOISTURE AXIS ALIGNS
ACROSS THE EASTERN HALF TO TWO THIRDS OF OUR CWA WITH SFC DPS
PROGGED NEAR 60F IN OUR FAR EAST. THE UNSEASONALLY WARM/HOT AIRMASS
REMAINS IN PLACE ACROSS OUR REGION AND WE WILL SEE ANOTHER DAY OF
HIGHS IN THE UPPER 80S TO NEAR 90F WHICH ARE AGAIN NEAR OR ABOVE
RECORDS FOR THE FIRST OF APRIL. SUNDAY NIGHT...SFC COLD FRONTAL
BOUNDARY IN NW NEBRASKA ADVANCES SOUTHEAST INTO OUR CWA...REACHING
ALL BUT OUR SOUTHEAST ZONES BY MORNING. GFS SUGGESTS PCPN MAY
DEVELOP IN VCNTY OF FRONT MAINLY ACROSS OUR NORTHERN ZONES...HOWEVER
SREF AND OTHER MODELS ARE NOT OVERLY SUPPORTIVE OF THIS ATTM AND
WILL KEEP THINGS DRY FOR THE TIME BEING.
OF BIGGER CONCERN TOWARD DAYBREAK MONDAY AND THROUGH THE DAY ON
MONDAY IS THE INCREASING NORTH WINDS FOLLOWING FROPA. MODELS
INDICATE 6HR PRESSURE RISES BEHIND THE BOUNDARY IN EXCESS OF 10MB TO
OUR WEST ALONG THE HIGH PLAINS AND AROUND 8MB ACROSS OUR CWA MIDDAY
MONDAY. GRADIENT REMAINS TIGHT THROUGH THE DAY AND ALL INDICATIONS
FM MODELS SUGGEST WE WILL AT A MINIMUM REACH WIND ADVISORY CRITERIA
AND PORTIONS OF OUR WEST MAY BE NEAR HIGH WIND WARNING CRITERIA AND
WILL NEED TO MONITOR CLOSELY.
THE UPPER LOW SHIFTS EAST ONTO THE SOUTHERN PLAINS TOWARD THE TX/OK
PANHANDLES MONDAY NIGHT. GFS IS FARTHER NORTH WITH CENTER OF SYSTEM
THAN ECMWF AND HAVE PLAYED MIDDLE GROUND AND FOLLOWED CLOSER TO
ENSEMBLE SOLUTIONS FOR NOW. PCPN CHCS INCREASE MONDAY NIGHT FM
SOUTH TO NORTH IN INCREASING LIFT/DYNAMICS ASSOCIATED WITH UPPER
LOW. HAVE LEFT THUNDER OUT FOR NOW AS BETTER INSTABILITY REMAINS TO
OUR SOUTH BUT THIS MAY NEED TO BE ADJUSTED AS TRACK OF SYSTEM IS
REFINED.
LONG TERM...TUESDAY THROUGH FRIDAY. BIGGEST CONCERN IN THE
EXTENDED LOOKS TO BE THE TRACK OF THE UPPER LOW WHICH IS FORECAST
AFFECT OUR AREA MID WEEK.
LATEST RUN OF THE EXTENDED MODELS STILL SHOWING PLENTY OF
DIFFERENCES ON TRACK OF THE UPPER LOW. OPERATIONAL GFS IS ONE OF
THE QUICKEST SOLUTIONS AS IT TAKES THE 500 MB LOW FROM THE OK
PANHANDLE AT 12Z TUE TO THE SOUTHERN EDGE OF OUR CWA BY 12Z
WED...AND THEN PUSHES IT QUICKLY EAST TO THE NORTHEAST TIP OF
MISSOURI BY 12Z THU. OF COURSE THE PERTURBATION RUNS OF THE GFS HAVE
THE LOW ALL OVER THE PLACE. THE EC IS A LITTLE QUICKER THAN THE
PREVIOUS EC RUN AS IT MOVES THE LOW FROM ERN NEW MEXICO AT 12Z TUES
TO A LITTLE SE OF DDC AT 12Z WED...AND THEN INTO NW ARKANSAS BY 12Z
THU. THE GEM IS SIMILAR IN SPEED WITH THE SYSTEM BUT A LITTLE
FURTHER SOUTH WITH THE TRACK. ALL OF THE MODELS BRING THIS SYSTEM ON
SHORE TODAY AND THEN SPLIT THE ENERGY...TAKING SOME NORTH AND SOME
SOUTH. HOPEFULLY THE PICTURE GETS A LITTLE MORE CLEAR IN THE NEXT 24
HRS AS THE LOW MOVES ONTO THE CONUS. BIGGEST IMPLICATIONS FOR US
WILL BE DURATION OF THE PRECIPITATION. COULD SEE OFF AND ON RAIN
TUESDAY AND WED WITH A NORTHERN TRACK...OR THE NORTHERN PART OF THE
CWA MIGHT MISS OUT IF IT GOES SOUTH. IT DOES APPEAR THAT IT SHOULD
PUSH EAST ON THUR AS NEXT UPSTREAM SYSTEM IS SET TO MOVE INTO THE
WESTERN U.S. WHICH SHOULD KEEP THINGS PROGRESSIVE. INSTABILITY
LOOKS MARGINAL ON TUESDAY SO WILL KEEP THUNDER OUT FOR NOW.
OTHERWISE TEMPERATURES SHOULD STILL BE ABOVE NORMAL WITH HIGHS IN
THE UPPER 50S ON TUESDAY AND THEN CLIMBING BACK TO NEAR 70 FOR
THURSDAY AND FRIDAY. ALSO --- IT STILL DOES NOT LOOK LIKE WE WILL
GET BELOW FREEZING THROUGH THE UPCOMING WORKWEEK.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM/AVIATION...EWALD
AREA FORECAST DISCUSSION
NWS HASTINGS NE
330 AM CDT SAT MAR 31 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT. THE PATTERN ALOFT
FEATURED SUBTLE RIDGING ACROSS THE CENTRAL PLAINS AND RIDGE IS
FORECAST TO EXPAND/BUILD THIS WEEKEND AS PACIFIC TROUGH REACHES THE
WESTERN CONUS. THIS WILL ALLOW A VERY WARM AIRMASS...ON THE ORDER
OF +3.3 STANDARD DEVIATIONS FOR H85 TEMPS...TO SETTLE ACROSS THE
CENTRAL PLAINS...AND FORECAST SOUNDINGS SUGGEST MIXING WILL BE
EVEN HIGHER THAN THIS LEVEL. RIDGE AXIS WILL SHIFT EASTWARD ON
SUNDAY AS UPPER TROUGH MOVES INTO THE ROCKIES WITH FLOW ALOFT
TRANSITIONING SOUTHWESTERLY. THE UPPER LOW IS FORECAST TO EMERGE
ONTO THE PLAINS MONDAY/MONDAY ALTHOUGH MODELS ARE NOT CONSISTENT
ON THE TRACK OF SYSTEM ATTM AND FOLLOWED CLOSER TO ENSEMBLES FOR
NOW.
HEADING INTO TODAY...MODELS HINT AT AN OUTSIDE CHCS FOR SOME LIGHT
CONVECTION PRIOR TO DAYBREAK IN PRESENCE OF SOME MID LEVEL WAA
ACROSS OUR NORTHERN COUNTIES. WILL MONITOR TRENDS OF THIS FOR THE
NEXT SEVERAL HOURS. THIS MORNING INTO EARLY AFTN A WEAK SURFACE
TROUGH WILL SLIDE EAST ACROSS NEBRASKA SHIFTING WINDS WESTERLY CAUSING
MOISTURE AXIS TO SHIFT EASTWARD. MODEL FORECAST SOUNDINGS SUGGEST
MIXING THIS AFTN AROUND H75 WITH WINDS AT THE TOP OF THE LAYER
ROUGHLY BETWEEN 11KTS AND 20KTS ACROSS OUR WESTERN CWA WHILE RH
VALUES DROP NEAR TO BELOW 20 PERCENT GENERALLY WEST OF HIGHWAY
281. LOCATIONS FROM ROUGHLY ORD TO LEXINGTON TO ARAPAHOE LOOK LIKE
THEY WILL MEET THE LOW RH CRITERIA FOR 3HRS WITH MAIN QUESTION
BEING WILL WINDS BE GUSTY ENOUGH FOR FIRE WEATHER HEADLINE.
SURFACE GRADIENT RELAXES SOME IN OUR WEST FOLLOWING BOUNDARY AND
MODELS SUGGEST SFC DPS MAY ACTUALLY RISE SOME IN AFTN AS WEST
WINDS TURN MORE SOUTHWESTERLY. FIRE WEATHER HEADLINE IS NOT A SLAM
DUNK DUE TO UNCERTAINTY IN WIND SPEEDS. HRRR WIND GUSTS DECREASE
ACROSS OUR WEST THIS AFTN AND THIS IS SUPPORTED BY 06Z NAM
SOUNDINGS WHERE WINDS AT THE TOP OF THE MIXED LAYER DECREASE
BETWEEN 21Z AND 00Z. GIVEN THE DECREASING WIND TREND WILL NOT GO
WITH HEADLINE ATTM AS OUR STRONGER WINDS WILL RESIDE EAST OF OUR
LOW RH AREA. THAT BEING SAID...DAY SHIFT WILL NEED TO CLOSELY
MONITOR FOR RED FLAG CONDITIONS.
HIGH TEMPERATURES THIS AFTERNOON LOOK TO BE NEAR OR AT RECORD
BREAKING LEVELS. RECORD FOR GRAND ISLAND TODAY IS 90F SET IN 1978.
RECORD FOR HASTINGS IS 89F SET IN 1946 AND RECORD FOR KEARNEY IS
88F SET IN 1946. CURRENT FORECAST HAS MAX TEMPS RIGHT AROUND THESE
RECORD READINGS AND MARCH WILL DEFINITELY END ON A HOT NOTE.
OVERNIGHT...THE SURFACE TROUGH DEEPENS ALONG THE HIGH PLAINS AND
MOISTURE MAKES A BETTER SURGE NORTH THRU KS INTO SOUTHERN NEBRASKA.
THE GFS MORE SO THAN THE NAM SUGGESTS POTENTIAL FOR SOME LOW CLOUD
DEVELOPMENT MAINLY ACROSS NC KS AND INCREASED CLOUD COVER AND
INCLUDED SOME PATCHY FOG FOR NOW.
ON SUNDAY...THE SURFACE LOW DEEPENS IN EASTERN COLORADO WITH
SOUTHERLY LLVL FLOW INCREASING ACROSS OUR CWA. MOISTURE AXIS ALIGNS
ACROSS THE EASTERN HALF TO TWO THIRDS OF OUR CWA WITH SFC DPS
PROGGED NEAR 60F IN OUR FAR EAST. THE UNSEASONALLY WARM/HOT AIRMASS
REMAINS IN PLACE ACROSS OUR REGION AND WE WILL SEE ANOTHER DAY OF
HIGHS IN THE UPPER 80S TO NEAR 90F WHICH ARE AGAIN NEAR OR ABOVE
RECORDS FOR THE FIRST OF APRIL. SUNDAY NIGHT...SFC COLD FRONTAL
BOUNDARY IN NW NEBRASKA ADVANCES SOUTHEAST INTO OUR CWA...REACHING
ALL BUT OUR SOUTHEAST ZONES BY MORNING. GFS SUGGESTS PCPN MAY
DEVELOP IN VCNTY OF FRONT MAINLY ACROSS OUR NORTHERN ZONES...HOWEVER
SREF AND OTHER MODELS ARE NOT OVERLY SUPPORTIVE OF THIS ATTM AND
WILL KEEP THINGS DRY FOR THE TIME BEING.
OF BIGGER CONCERN TOWARD DAYBREAK MONDAY AND THROUGH THE DAY ON
MONDAY IS THE INCREASING NORTH WINDS FOLLOWING FROPA. MODELS
INDICATE 6HR PRESSURE RISES BEHIND THE BOUNDARY IN EXCESS OF 10MB TO
OUR WEST ALONG THE HIGH PLAINS AND AROUND 8MB ACROSS OUR CWA MIDDAY
MONDAY. GRADIENT REMAINS TIGHT THROUGH THE DAY AND ALL INDICATIONS
FM MODELS SUGGEST WE WILL AT A MINIMUM REACH WIND ADVISORY CRITERIA
AND PORTIONS OF OUR WEST MAY BE NEAR HIGH WIND WARNING CRITERIA AND
WILL NEED TO MONITOR CLOSELY.
THE UPPER LOW SHIFTS EAST ONTO THE SOUTHERN PLAINS TOWARD THE TX/OK
PANHANDLES MONDAY NIGHT. GFS IS FARTHER NORTH WITH CENTER OF SYSTEM
THAN ECMWF AND HAVE PLAYED MIDDLE GROUND AND FOLLOWED CLOSER TO
ENSEMBLE SOLUTIONS FOR NOW. PCPN CHCS INCREASE MONDAY NIGHT FM
SOUTH TO NORTH IN INCREASING LIFT/DYNAMICS ASSOCIATED WITH UPPER
LOW. HAVE LEFT THUNDER OUT FOR NOW AS BETTER INSTABILITY REMAINS TO
OUR SOUTH BUT THIS MAY NEED TO BE ADJUSTED AS TRACK OF SYSTEM IS
REFINED.
.LONG TERM...TUESDAY THROUGH FRIDAY. BIGGEST CONCERN IN THE
EXTENDED LOOKS TO BE THE TRACK OF THE UPPER LOW WHICH IS FORECAST
AFFECT OUR AREA MID WEEK.
LATEST RUN OF THE EXTENDED MODELS STILL SHOWING PLENTY OF
DIFFERENCES ON TRACK OF THE UPPER LOW. OPERATIONAL GFS IS ONE OF
THE QUICKEST SOLUTIONS AS IT TAKES THE 500 MB LOW FROM THE OK
PANHANDLE AT 12Z TUE TO THE SOUTHERN EDGE OF OUR CWA BY 12Z
WED...AND THEN PUSHES IT QUICKLY EAST TO THE NORTHEAST TIP OF
MISSOURI BY 12Z THU. OF COURSE THE PERTURBATION RUNS OF THE GFS HAVE
THE LOW ALL OVER THE PLACE. THE EC IS A LITTLE QUICKER THAN THE
PREVIOUS EC RUN AS IT MOVES THE LOW FROM ERN NEW MEXICO AT 12Z TUES
TO A LITTLE SE OF DDC AT 12Z WED...AND THEN INTO NW ARKANSAS BY 12Z
THU. THE GEM IS SIMILAR IN SPEED WITH THE SYSTEM BUT A LITTLE
FURTHER SOUTH WITH THE TRACK. ALL OF THE MODELS BRING THIS SYSTEM ON
SHORE TODAY AND THEN SPLIT THE ENERGY...TAKING SOME NORTH AND SOME
SOUTH. HOPEFULLY THE PICTURE GETS A LITTLE MORE CLEAR IN THE NEXT 24
HRS AS THE LOW MOVES ONTO THE CONUS. BIGGEST IMPLICATIONS FOR US
WILL BE DURATION OF THE PRECIPITATION. COULD SEE OFF AND ON RAIN
TUESDAY AND WED WITH A NORTHERN TRACK...OR THE NORTHERN PART OF THE
CWA MIGHT MISS OUT IF IT GOES SOUTH. IT DOES APPEAR THAT IT SHOULD
PUSH EAST ON THUR AS NEXT UPSTREAM SYSTEM IS SET TO MOVE INTO THE
WESTERN U.S. WHICH SHOULD KEEP THINGS PROGRESSIVE. INSTABILITY
LOOKS MARGINAL ON TUESDAY SO WILL KEEP THUNDER OUT FOR NOW.
OTHERWISE TEMPERATURES SHOULD STILL BE ABOVE NORMAL WITH HIGHS IN
THE UPPER 50S ON TUESDAY AND THEN CLIMBING BACK TO NEAR 70 FOR
THURSDAY AND FRIDAY. ALSO --- IT STILL DOES NOT LOOK LIKE WE WILL
GET BELOW FREEZING THROUGH THE UPCOMING WORKWEEK.
&&
.AVIATION...06Z KGRI TAF. EXPECT VFR CONDITIONS THROUGH THE
FORECAST PERIOD. UPPER LEVEL RIDGE WILL MOVE INTO THE CENTRAL
PLAINS WITH WEAK SURFACE TROUGH JUST TO THE WEST. WINDS SHOULD
PICK UP AROUND LUNCHTIME AS WE MIX OUT WELL FOR THE AFTERNOON.
WINDS NOT PROJECTED TO BE OVERLY STRONG ALOFT SO WILL KEEP GUSTS
TO AROUND 20 KTS. OTHERWISE NOT EXPECTING MUCH IN THE WAY OF
CLOUDS EXCEPT FOR A FEW HIGH CLOUDS EARLY. MAY SEE A FEW CU IN THE
AFTERNOON ALTHOUGH CONVECTIVE TEMPS MAY BE HARD TO REACH IN SPITE
OF VERY WARM TEMPS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM/AVIATION...EWALD
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1220 AM CDT SAT MAR 31 2012
.AVIATION...06Z KGRI TAF. EXPECT VFR CONDITIONS THROUGH THE
FORECAST PERIOD. UPPER LEVEL RIDGE WILL MOVE INTO THE CENTRAL
PLAINS WITH WEAK SURFACE TROUGH JUST TO THE WEST. WINDS SHOULD
PICK UP AROUND LUNCHTIME AS WE MIX OUT WELL FOR THE AFTERNOON.
WINDS NOT PROJECTED TO BE OVERLY STRONG ALOFT SO WILL KEEP GUSTS
TO AROUND 20 KTS. OTHERWISE NOT EXPECTING MUCH IN THE WAY OF
CLOUDS EXCEPT FOR A FEW HIGH CLOUDS EARLY. MAY SEE A FEW CU IN THE
AFTERNOON ALTHOUGH CONVECTIVE TEMPS MAY BE HARD TO REACH IN SPITE
OF VERY WARM TEMPS.
&&
.PREV DISCUSSION... /ISSUED 754 PM CDT FRI MAR 30 2012/
UPDATE...HAVE GONE AHEAD AND UPDATED THE FORECAST IN ANTICIPATION
OF THE ONE FINAL STORM IN MITCHELL COUNTY FINALLY DIEING OFF BETWEEN
8 AND 9 PM WITH SUNDOWN. ENTERTAINING SOME THOUGHT OF A LATE NIGHT
OR NEAR DAWN ISOLATED SHOWER IN NORTHERN CWFA WITH DECENT WARM
ADVECTION. ALL FORECASTS DRY...BUT WRF AND HRRR BOTH HAVE SOME
IDEA OF THIS POSSIBILITY.
PREV DISCUSSION... /ISSUED 614 PM CDT FRI MAR 30 2012/
UPDATE...ADDED A FEW THUNDERSTORMS THROUGH ABOUT 8 PM ALONG A
WEAKISH SURFACE TROUGH WITH A VERY NARROW SURGE OF MOISTURE INTO
THE SOUTHEAST CWFA. AN ISOLATED STRONG STORM IS POSSIBLE.
ELSEWHERE ITS DRY AND NICE.
PREV DISCUSSION... /ISSUED 358 PM CDT FRI MAR 30 2012/
SHORT TERM...TONIGHT AND TOMORROW.
AS THE SHORT WAVE TROUGH AXIS PUSHES ACROSS THE CENTRAL PLAINS...A
FEW RAIN SHOWERS HAVE POPPED UP ACROSS NORTHEAST NEBRASKA. A FEW OF
THESE COULD BECOME THUNDERSTORMS AND MOVE ACROSS NORTHEAST PORTIONS
OF THE FORECAST AREA.
UPPER LEVEL ANALYSIS INDICATES MOSTLY ZONAL FLOW ACROSS THE CONUS
WITH A SHORT WAVE TROUGH ACROSS THE CENTRAL PLAINS. THE CORE OF THE
UPPER LEVEL JET REMAINS STRONGEST OFF THE WEST COAST...ALTHOUGH A
SECONDARY JET AXIS CONTINUES TO PUSH OFF THE EAST COAST. AT 500
MB...ZONAL FLOW CONTINUES ACROSS THE CONUS...WHILE A STRONG LOW
PRESSURE SYSTEM SPINS ACROSS CANADA. AT THE MID LEVELS...ZONAL FLOW
IS PREDOMINANT...ALTHOUGH THERE REMAINS A FEW SHORT WAVE TROUGHS
ACROSS THE REGION. ONE TROUGH REMAINS CENTERED OFF THE EAST OF THE
PLAINS WHILE A SECONDARY TROUGH BEGAN MOVING ACROSS THE CENTRAL
PLAINS TODAY. AT THE SURFACE A WEAK HIGH PRESSURE SYSTEM PASSED JUST
TO THE SOUTH OF THE REGION WHILE A WEAK LOW PRESSURE SYSTEM MOVED
ACROSS THE NORTHERN PLAINS FROM THE FRONT RANGE OF THE ROCKIES.
UPPER LEVEL RIDGING WILL BUILD ACROSS THE PLAINS ON SATURDAY...WHILE
THE MAIN CORE OF THE JET WRAPS AROUND THE TOP OF THE RIDGE. SKIES
ARE EXPECTED TO REMAIN PARTLY CLOUDY AS THE UPPER LEVEL JET NOSES
ACROSS THE REGION SATURDAY MORNING...AND WITH THE DEVELOPMENT OF
CUMULUS DURING THE AFTERNOON. 850 TEMPERATURES ARE EXPECTED TO SOAR
ACROSS THE REGION TO NEAR 20 DEGREES...COMBINED WITH STRONG BOUNDARY
LAYER MIXING...HIGH TEMPERATURES COULD EASILY REACH RECORD HIGHS
NEAR 90 DURING THE AFTERNOON TOMORROW. FIRE WEATHER THREATS WILL
REMAIN A CONCERN SATURDAY AFTERNOON AS RELATIVE HUMIDITY VALUES ARE
ALREADY FORECAST TO BE NEAR OR SLIGHTLY BELOW 20 PERCENT ACROSS THE
NORTHWEST. ALTHOUGH DEWPOINTS ARE QUITE LOW ALREADY...MODEL
SOUNDINGS INDICATE BOUNDARY LAYER MIXING TO NEAR 700 MB...THUS
REDUCING DEWPOINTS EVEN FARTHER. DECIDED NOT TO GO WITH ANY FIRE
WATCH AT THIS POINT...AS STRONGEST WINDS WILL REMAIN JUST UNDER
CRITERIA AND ACROSS THE NORTHEAST...VERSUS LOW RH VALUES ACROSS THE
NORTHWEST.
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY
FOR TUESDAY AND BEYOND...USED A BLEND OF 00Z OPERATIONAL ECMWF AND
ITS ENSEMBLES...TRANSITIONING TO ENSEMBLES TOWARD THE OUTER PERIODS
TO HELP TAKE A MIDDLE GROUND FOR MITIGATING DISCREPANCIES WITHIN THE
SYNOPTIC SCALE.
A PROMINENT UPPER LEVEL RIDGE WILL BE IN PLACE FOR SATURDAY NIGHT AS
A TROUGH MOVES ONTO THE WEST COAST...WITH A MODEST LOW-LEVEL JET
DEVELOPING OVER THE PLAINS. PROGGED SOUNDINGS INDICATE DRY CONDITIONS
WITH WARM AIR ADVECTION KEEPING LOW TEMPERATURES IN THE 50S.
SOUTH WIND WILL BECOME A BIT MORE BREEZY ON SUNDAY AS THE SURFACE
PRESSURE GRADIENT INCREASES AHEAD OF AN APPROACHING COLD FRONT. WITH
SOME INCREASED MOISTURE RETURN AT THE SURFACE...HIGHS WILL TOP OUT
IN THE MID 80S...MUCH ABOVE NORMAL BUT A TAD COOLER THAN HIGHS ON
SATURDAY. AS THE TROUGH MOVES EAST THROUGH THE ROCKY
MOUNTAINS...MODELS POINT TOWARD A CLOSED LOW DEVELOPING WITHIN THE
TROUGH BY SUNDAY NIGHT.
THE COLD FRONT WILL FINALLY BLOW THROUGH LATE SUNDAY NIGHT/EARLY
MONDAY MORNING...LATE ENOUGH FOR HIGHS TO BE QUITE WARM IN THE 50S
FOR MOST LOCATIONS. THERE IS STILL SOME UNCERTAINTY TO TIMING OF
THIS FRONT AND IT COULD ARRIVE A LITTLE LATER...GIVEN LATEST TRENDS.
THIS APPEARS TO BE A DRY COLD FRONT PASSAGE WITH NEARLY BONE DRY
MID-LEVELS BUT THERE COULD BE ENOUGH MOISTURE AND INSTABILITY TO
GIVE US A SMALL CHANCE OF SHOWERS AND PERHAPS THUNDERSTORMS WITH
SOME POSSIBLE INSTABILITY AHEAD OF THE FRONT. IMPRESSIVE HEIGHT RISES
WILL PROVIDE A STIFF NORTH WIND WITH SIGNIFICANTLY COLDER HIGHS IN
THE 60S...BUT STILL ABOVE NORMAL FOR THIS TIME OF YEAR. THERE COULD
BE A SMALL CHANCE OF ELEVATED POST-FRONTAL PRECIPITATION FOR MONDAY
INTO TUESDAY FOR PARTS OF THE CWA. LEFT SMALL CHANCES OF SHOWERS FOR
MONDAY NIGHT AS THE NORTHERN STREAM WAVE PASSES AND SOME LOWER
CHANCES IN THE SOUTH INTO TUESDAY...AS THEY COULD BE CLOSE ENOUGH TO
STILL BE UNDER THE INFLUENCE OF THE CLOSE LOW TO THE SOUTH.
INSTABILITY SHOULD BE LIMITED BY THEN.
MODELS DIFFER WITH THE TRACK OF THE CLOSED LOW FOR THE LAST FEW DAYS
OF THE EXTENDED FORECAST AFTER THE LOW SPILLS OUT INTO THE SOUTHERN
PLAINS BY AS THE ECMWF POINTS THIS LOW EAST ACROSS THE GULF
COAST...WHILE THE GFS SWINGS THE LOW A BIT FARTHER NORTHEAST INTO
THE MID-SOUTH. BOTH SOLUTIONS SHOULD KEEP CHANCES OF PRECIPITATION
SOUTH OF THE CWA.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1141 PM CDT FRI MAR 30 2012
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
DID NOT MENTION ANY FOG TOWARD MORNING...BUT MODELS DO SHOW SOME
INCREASE IN LOW LEVEL RH TOWARD SUNRISE. EXPECT CLOUDS TO BE MAINLY
ABOVE 12000 FEET THROUGH THE PERIOD. SOME SCATTERED CLOUDS POSSIBLE
AROUND 5000 FEET SATURDAY AFTERNOON.
MILLER
&&
.PREV DISCUSSION... /ISSUED 314 PM CDT FRI MAR 30 2012/
SHORT TERM...TONIGHT THROUGH MONDAY.
SEVERAL PERIODS OF ISOLD/SMALL POP CONVECTION CHANCES DOT SHORT
TERM FORECAST LANDSCAPE OTHERWISE TEMPERATURES ARE THE PRIMARY CONCERN.
FIRST SMALL PRECIP CHANCE IS EARLY THIS EVENING AS UPPER SHORT
WAVE ENERGY PUSHING TOWARD MO RIVER PER AFTERNOON STLT IMAGERY
FOCUSES ON CONVERGENT BOUNDARY WHICH AT 19Z STRETCHED FROM YKN-
TQE-OMA WITH SECOND CONVERGENT AREA APPROACHING LNK AND OLU.
SELECTIVE MODELS...I.E. HRRR+4KM WRF HAVE GENERATED SMALL QPF CLUSTER
WHICH PUSHES INTO SWRN IA BEFORE WEAKENING FAIRLY QUICKLY WITH
LOSS OF HEATING. MEANWHILE RUC KEPT MID LAYER PRETTY DRY/WELL
MIXED CAP AND GFS NOT OVERLY SUPPORTIVE EITHER. WILL EXTEND SMALL
POPS ERN ZONES EARLY THIS EVENING...HOWEVER...DUE TO CONVERGENT
CU AND OCNL WEAK CELLS THAT HAD CONTD TO DEVELOP ON RADAR IN
19-20Z PERIOD.
OTHERWISE FLAT UPPER RIDGING SPREADING ACROSS PLAINS ON SATURDAY
WILL BRING EVEN WARMER READINGS TO AREA WITH NEAR RECORD HIGHS
LIKELY AT OFK/OMA AND LNK. DID NOT INCLUDE LATE AFTERNOON POPS AT
THIS TIME NEAR H85 THERMAL AXIS NEAR OR N OF OMA AND POINTS
EWD...BUT CONVECTIVE TEMPERATURES COULD BE REACHED PER NAM
FORECAST SOUNDINGS. AREA WILL HAVE TO BE MONITORED...BUT LEFT OUT
DUE TO AREA APPEARS WILL EXTEND IN GENERAL UPPER RIDGE AREA.
UPPER RIDGE AMPS/SHIFTS EAST A LITTLE SUNDAY SPREADING EVEN
WARMER H85 TEMPS OVER AREA. RECORD HIGHS AGAIN APPROACHED MANY
LOCATIONS AS IT APPEARS MOST HIGHS SHOULD BE A FEW DEGREES WARMER
THAN THOSE EXPECTED ON SATURDAY.
LEFT IN SMALL POPS WITH FRONT ON MONDAY ALTHOUGH THERE WAS LITTLE
UPPER SUPPORT WITH FRONT PUSHING INTO NEGATIVELY TILTED UPPER
RIDGE AS ENERGY SPLITS. HOWEVER...WITH VERY WARM TEMPERATURES
AHEAD OF THIS STRONGER COLD FRONT...AND DELAYED TIMING A BIT...DID
BOOST MAX TEMPS A CATEGORY OR SO SERN 1/2-2/3RDS OF THE AREA.
LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
FOCUS TURNS TO HOW FAR NORTH UPPER LOW WILL DRIFT FOR POSSIBLE
PRECIP CHANCES...IF IT LIFTS FAR ENOUGH N...OR FOR POTENTIAL
FROST/ISOLD FREEZING TEMPERATURES IF PATTERN DEVELOPS INTO A
STALLED REX-LIKE BLOCK WITH UPPER LOW FARTHER SOUTH. ALTHOUGH
LOWERED A FEW LOW TEMPERATURES INTO UPPER 30S-40ISH WED AM DID NOT
STRAY TOO FAR FROM MODEL BLEND WITH OTHER LOW TEMPS AS TOO MANY
UNCERTAINTIES PERSIST. DID ALSO LOWER MAX TEMPS A LITTLE IN WED-
THU PERIOD AND SPREAD POPS A LITTLE FARTHER NW MON NIGHT INTO TUE.
HOWEVER...ENTIRE PERIOD WILL LIKELY SEE CHANGES...AND AT LEAST
MODERATE ONES...AS CONFIDENCE WAS LOW WITH HOW PATTERN WILL
DEVELOP.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ELKO NV
1125 PM PDT FRI MAR 30 2012
.SYNOPSIS...A FEW SHOWERS WILL LINGER THROUGH THE EARLY MORNING
HOURS. STRONG GUSTY WINDS WILL IMPACT THE REGION SATURDAY AHEAD
OF A STRONG SURFACE COLD FRONT. BLOWING DUST AND ISOLATED
THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT. SATURDAY NIGHT
TEMPERATURES WILL RAPIDLY DROP BEHIND THE FRONT WITH SCATTERED
SNOW SHOWERS EXPECTED ON SUNDAY. A WARMING TREND AND DRIER WEATHER
IS EXPECTED FOR THE BEGINNING OF NEXT WEEK.
&&
.UPDATE...ANOTHER WEAK SHORTWAVE IS GENERATING SOME SHOWERS ACROSS
THE CWFA. UPDATED THE FORECAST TO INCLUDE ISOLATED SHOWERS ACROSS
MAINLY NORTHERN ZONES. NONE OF THE MODELS ALLUDED TO THIS LAST
WAVE. AND CURRENT MODELS ARE SHOWING AMPLIFICATION OF RIDGING THAT
SHOULD FORCE THE MOISTURE NORTH SO JUST UPDATED THROUGH 12Z THIS
MORNING...THEN DRY. WILL KEEP AN EYE ON THIS FOR THE NEXT PACKAGE
PRIOR TO THE STRONG WIND EVENT TODAY.
&&
.PREV DISCUSSION... /ISSUED AT 633 PM /
SYNOPSIS...STRONG GUSTY WINDS WILL IMPACT THE REGION SATURDAY
AHEAD OF A STRONG SURFACE COLD FRONT. BLOWING DUST AND ISOLATED
THUNDERSTORMS WILL DEVELOP AHEAD OF THE FRONT. SATURDAY NIGHT
TEMPERATURES WILL RAPIDLY DROP BEHIND THE FRONT WITH SCATTERED
SNOW SHOWERS EXPECTED ON SUNDAY. A WARMING TREND AND DRIER WEATHER
IS EXPECTED FOR THE BEGINNING OF NEXT WEEK.
UPDATE...WINDS HAVE DECREASED OVER HUMBOLDT COUNTY THIS EVENING
SO HAVE CANCELLED THE WIND ADVISORY. WINDS ARE STILL EXPECTED TO
INCREASE SIGNIFICANTLY SATURDAY MORNING FOR A HIGH WIND WARNING
OVER THE ENTIRE CWA. SEE PREVIOUS DISCUSSION.
PREV DISCUSSION... /ISSUED AT 311 PM /
SHORT TERM...TONIGHT THROUGH MONDAY. CURRENT WATER VAPOR IMAGERY
AND RUC ANALYSIS SHOWS A STRONG PACIFIC NORTHWEST JET MAX OF
130KTS AHEAD OF A DIGGING PACIFIC 500MB TROUGH. THE UPPER LEVEL
JET WILL CONTINUE TO PROGRESS EASTWARD INTO THE GREAT BASIN
TONIGHT. STILL LOOKING LIKE AN IMPRESSIVE WIND EVENT DURING THE
DAY TOMORROW ACROSS ALL ZONES. ALL HIGH WIND INDICES ARE LOOKING
GOOD WITH 700/500MB WIND ANOMALIES OF +3 TO 4 STANDARD
DEVIATIONS...MAV GUIDANCE FOR ALL TAF LOCATIONS IS SHOWING SOLID
32-38KTS...MIXING HEIGHTS ARE FORECASTED TO REACH 550MB...AND A
993 SURFACE LOW OVER SOUTHERN IDAHO WILL HELP ENHANCE LOW LEVEL
NORTH/SOUTH CHANNELING OF WINDS. HAVE UPGRADED ALL ZONES TO A HIGH
WIND WARNING FROM THE ONGOING WATCH. WILL MOST LIKELY HAVE SOME
BLOWING DUST TOMORROW WITH THE PROLONGED WIDE SPREAD WINDS. IN
ADDITION THERE COULD BE A FEW ISOLATED STRIKES DURING THE
AFTERNOON HOURS ALONG THE ID/OR/NV BORDER.
SATURDAY NIGHT THE FRONT WILL PUSH THROUGH THE AREA...WITH A VERY
TIGHT TEMP GRADIENT BEHIND THE FRONT. SHOULD SEE 20-30 DEGREE
TEMPS DROPS IN JUST A FEW HOURS BEHIND THE FRONT. PRECIP IS STILL
TRENDING LIGHT BEHIND THE FRONT...SO KEPT QPF AND SNOW AMOUNTS ON
THE LOW SIDE. MOST AREA WILL ONLY SEE A FEW HUNDREDTHS OF LIQUID
WITH MAYBE A TRACE OF SNOW ABOVE 5500FT. THERE STILL COULD BE A
FEW INCHES ACROSS THE MOUNTAINS OF EASTERN NV BY DAYBREAK SUNDAY.
SUNDAY A COLD UPPER LEVEL 500MB TROUGH WILL BE CENTERED OVER THE
REGION...LEADING TO STEEP LOW LEVEL LAPSE RATES. CONVECTIVE SNOW
SHOWERS WILL CONTINUE THROUGH THE DAY...WITH A FEW ADDITIONAL
INCHES OF ACCUMULATIONS ACROSS THE MOUNTAINS...ONLY A DUSTING IS
EXPECTED ACROSS THE WARMER VALLEYS. WARMER IS RELATIVE AS HIGHS
ARE ONLY EXPECTED TO REACH THE LOW TO MID 40S ACROSS THE VALLEYS
WITH BELOW ZERO TEMPS IN THE MOUNTAINS. RIDGING QUICKLY RETURNS BY
MONDAY...BRINGING A NICE DAY WITH MOSTLY CLEAR SKIES AND TEMPS
REBOUNDING INTO THE LOW 50S ONCE AGAIN...AFTER A COLD START TO THE
DAY WITH LOWS IN THE LOW 20S.
LONG TERM...MONDAY NIGHT THROUGH NEXT THURSDAY. GFS AND EURO IN
GOOD AGREEMENT MONDAY NIGHT THROUGH LATE TUESDAY NIGHT WITH
INCREASING SOUTHWEST FLOW FROM APPROACHING LONG WAVE TROUGH OFFSHORE
IN THE PACNW. AFTER THAT...THE GFS BECOMES SLIGHTLY DEEPER AND
SLIGHTLY NEGATIVELY TILTED AND CLOSES OFF A LOW AND MOVES IT INTO
THE INTERIOR PACIFIC NW...TRAILING A VORT LOBE OVER THE GREAT BASIN.
THE EURO HOLD BACK THIS LOW WHILE CLOSING IT OFF BUT MORE
SHALLOW...AND POSITIVELY TILTING THE TRAILING TROF. HENCE IT BRINGS
IN THE COLD FRONT...HUMIDITY...AND PRECIP LATER. HAVE OPTED TO GOT
WITH THE FASTER GFS. THE DRY SOUTHWEST FLOW WILL KEEP THINGS DRY
THROUGH WEDNESDAY MORNING WHEN A LITTLE SHORT WAVE WILL CROSS
NORTHERN NEVADA AND PROVIDE VERY LOW CHANCE POPS ALONG THE IDAHO
BORDER WITH SLIGHT CHANCE POPS IN NORTHERN NEVADA WITH BARELY DOUBLE
DIGIT POPS IN CENTRAL AND EASTERN NEVADA. DRY SOUTH TO SOUTHWEST
WINDS WILL INCREASE IN SPEED IN ADVANCE OF THE WAVE APPROACHING
TUESDAY NIGHT/WEDNESDAY MORNING. TEMPS SHOULD BE COOLER THAN OUR
CURRENT ABOVE NORMAL PATTERN. MINS WILL BE LOWER WITH FEWER CLOUDS
AND LIGHTER WINDS. AS CLOSED GFS LOW MOVES NORTH OF THE GREAT BASIN
EXPECTING TRAILING LOW LEVEL TROUGH TO CROSS THE STATE AND INCREASE
SOUTH-SOUTHWEST WINDS IN ADVANCE. MIGHT POSSIBLY MEET ADVISORY
CRITERIA LATE WEDNESDAY AND EARLY THURSDAY. POPS...TEMPS...REMAIN
CONSTANT DURING THE WED-THURSDAY FRAME.
AVIATION...A PACIFIC FRONT IS APPROACHING THE NORTHERN GREAT BASIN
AND WINDS AND CLOUDS WILL INCREASE OVER NIGHT AND ESPECIALLY ON
SATURDAY. ISOLATED SHOWERS WILL OCCUR NEAR KWMC AND KEKO ON
SATURDAY. CIGS AND VSBYS WILL BE TECHNICALLY VFR AT ALL SITES BUT
MOUNTAIN TOPS WILL BE POTENTIALLY OBSCURED AT ALL SITES. WINDS WILL
INCREASE TO OVER 35 KNOTS AT ALL SITES SATURDAY AFTERNOON WITH OVER
45 KNOTS AT KEKO...AND OVER 50 KNOTS AT KELY AND KTPH.
FIRE WEATHER...AN INTENSE COLD FRONT WILL ENTER THE FIRE DISTRICT
SATURDAY AFTERNOON AND EXIT EARLY SUNDAY MORNING. MIN RH WILL
GENERALLY BE AROUND 15% AND WIND GUSTS COULD REACH TO AROUND 70
MPH AS THE FRONT MOVES THROUGH SATURDAY AFTERNOON AND EVENING.
FUELS CONTINUE TO APPEAR NON-CRITICAL. AFTER COLLABORATION WITH
SPC...WILL HAVE A SEE-TEXT BOX FOR NORTHERN NYE COUNTY. FIRE
MANAGERS ARE URGED TO USE EXTREME CAUTION AND REFRAIN FROM ALL
BURNING SATURDAY AFTERNOON AND EVENING.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM 11 AM TO 11 PM PDT SATURDAY FOR EXTREME
EASTERN ELKO COUNTY...NORTHERN ELKO COUNTY...NORTHERN LANDER
COUNTY AND NORTHERN EUREKA COUNTY...NORTHERN NYE COUNTY...RUBY
MOUNTAINS/EAST HUMBOLDT RANGE...SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY...SOUTHWEST AND SOUTH CENTRAL ELKO
COUNTY...WHITE PINE COUNTY.
HIGH WIND WARNING FROM 8 AM TO 11 PM PDT SATURDAY FOR HUMBOLDT
COUNTY.
&&
$$
92/99
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
821 PM MDT SUN APR 1 2012
.UPDATE...WINDS HAVE SUBSIDED SOME WITH SUNSET...ENOUGH TO ALLOW
WIND ADVISORY TO EXPIRE. HOWEVER...EXPECT WINDS MAY ACTUALLY BEGIN
TO INCREASE AGAIN LATER TONIGHT AS THE COLD FRONT NEARS AND THE
SURFACE GRADIENT STRENGTHENS. ALSO SPREAD SOME TOKEN 10 POPS OVER
A BROADER AREA FROM GUP TO CHAMA AS LATEST RUC INDICATES THE UPPER
LOW CENTER MAY BECOME QUITE ELONGATED ALONG THE ARIZONA BORDER BY
12Z MON.
&&
.PREV DISCUSSION...327 PM MDT SUN APR 1 2012...
A DEEP UPPER LEVEL TROUGH CROSSING THE GREAT BASIN THIS AFTERNOON
WILL FORM A CLOSED LOW OVER GALLUP BY SUNRISE MONDAY...THEN PASS SLOWLY
EASTWARD OVER NEW MEXICO IN THE VICINITY OF I-40 MONDAY AND MONDAY
NIGHT. MODELS ARE IN NOW IN BETTER AGREEMENT THAT THE CENTER OF
THE UPPER LOW WILL PASS SLOWLY NORTHWARD THROUGH NORTHEAST NM
TUESDAY...BEFORE DRIFTING NORTHEASTWARD INTO KS OR EASTWARD INTO
OK TUESDAY NIGHT AND WEDNESDAY. THE NAM WAS AN OUTLIER TRACKING
THE SYSTEM FURTHER SOUTH THAN OTHER MODELS...BUT THE 18Z RUN HAS
NOW COME INTO ALIGNMENT WITH THE GFS AND ECMWF SOLUTIONS.
RAIN AND SNOW SHOWERS SHOULD DEVELOP IN THE N AND NW
MOUNTAINS...AS WELL AS THE FOUR CORNERS AREA OVERNIGHT TONIGHT.
PRECIPITATION WILL THEN SPREAD TO MOST OF NORTHERN AND CENTRAL NM
BY MONDAY AFTERNOON AND NIGHT...BEFORE GRADUALLY DIMINISHING FROM
THE SOUTHWEST TUESDAY AFTERNOON AND NIGHT. THE TRACK OF THE UPPER
LOW WILL PRODUCE DEEP UPSLOPE FLOW OUT OF THE E OR NE FROM THE
SANGRE DE CRISTO MOUNTAINS EASTWARD...AND POSSIBLY AS FAR SOUTH AS
THE SANDIA AND MANZANO MOUNTAINS AND CENTRAL HIGHLANDS.
THEREFORE...WE HAVE EXPANDED THE AERIAL COVERAGE OF THE WINTER
STORM WATCH FOR THE NORTHERN MOUNTAINS INTO THE NORTHEAST AND
CENTRAL HIGHLANDS...ESTANCIA VALLEY AND SANDIA/MANZANO MOUNTAINS.
IN ADDITION...THE WATCH HAS BEEN EXTENDED THROUGH TUESDAY
AFTERNOON BECAUSE MODELS HAVE SLOWED THE EXIT OF THE SYSTEM.
ACROSS THE HIGH TERRAIN...SNOW AMOUNTS MAY REACH AROUND 15 INCHES
OVER THE UPPER EAST SLOPES OF THE SANGRE DE CRISTOS. AT LOWER
ELEVATIONS...PARTS OF THE NE AND FAR NE HIGHLANDS LOCATED ALONG AND WEST
OF I-25 MAY ACCUMULATE SEVERAL INCHES OF SNOW. THIS COULD BE THE
CASE ALONG THE EAST SLOPES OF THE SANDIAS AND MANZANOS TO AROUND
CLINES CORNERS...TOO. HOWEVER...CHANCES ARE BETTER FARTHER NORTH.
LATER SHIFTS MAY NEED TO CONSIDER WINTER WEATHER ADVISORIES FOR A
FEW TO PERHAPS A HALF FOOT OF SNOW ACROSS THE JEMEZ AND WEST
CENTRAL MOUNTAINS...WITH LIGHTER AMOUNTS ACROSS THE UPPER RIO
GRANDE AND LOWER CHAMA RIVER VALLEYS...AND THE NORTHEAST PLAINS
LATE MONDAY THROUGH TUESDAY. TEMPERATURES AT 700 MB BOTTOM OUT
AROUND -6C MONDAY NIGHT...SO PRECIPITATION WILL PROBABLY MIX WITH
RAIN AT LOWER ELEVATIONS UNTIL THE OVERNIGHT AND EARLY MORNING
HOURS.
BESIDES THE PRECIPITATION THERE WILL PROBABLY BE ADDITIONAL
EPISODES OF STRONG WIND. STRONG AND GUSTY WINDS THIS AFTERNOON
WILL WEAKEN WITH SUNSET IN MOST LOCATIONS...EXCEPT OVER AND JUST
EAST OF THE SOUTH CENTRAL MOUNTAINS...WHERE WINDS ALOFT WILL
REMAIN STRONGEST TONIGHT AND A PACIFIC COLD FRONT WILL CROSS FROM
THE WEST TONIGHT. THE PACIFIC FRONT WILL CROSS THE SOUTHEAST
PLAINS MONDAY MORNING...WHILE A STRONG BACK DOOR COLD FRONT
PLUNGES SOUTHWARD THROUGH THE NORTHEAST PLAINS. MODELS DISAGREE ON
THE TIMING OF THE BACK DOOR FRONT...WITH THE NAM PLUNGING IT
SOUTHWARD MONDAY MORNING AND THE GFS WAITING UNTIL LATER IN THE
AFTERNOON. HOWEVER...THEY AGREE THAT THE FRONT WILL PACK WIND
GUSTS AROUND 50 MPH FROM THE EAST SLOPES OF THE SANGRES EASTWARD
ACROSS THE PLAINS UNTIL LATE MONDAY NIGHT. THE COMBINATION OF WIND
AND SNOW MONDAY NIGHT WILL PROBABLY PRODUCE DANGEROUS TRAVEL
CONDITIONS ALONG THE I-25 CORRIDOR FROM LAS VEGAS NORTHWARD OVER
RATON PASS.
AFTER HIGH TEMPERATURES 12 TO 22 DEGREES ABOVE NORMAL IN EASTERN
NEW MEXICO TODAY...AND 6 TO 12 DEGREES ABOVE NORMAL FARTHER
WEST...READINGS WILL PLUMMET BELOW NORMAL ON MONDAY. MONDAYS HIGH
TEMPERATURES WILL DROP A STARTLING 15 TO 32 DEGREES BELOW TODAYS
READINGS IN CENTRAL AND EASTERN AREAS. READINGS WILL REMAIN BELOW
NORMAL TUESDAY.
WEDNESDAY...THE WEATHER WILL BECOME DRY...SKIES WILL CLEAR AND
HIGH TEMPERATURES WILL CLIMB TO NEAR AND ABOVE NORMAL AGAIN AS A
RIDGE OF HIGH PRESSURE CROSSES ALOFT. THE RIDGE AXIS WILL PASS
EAST OF THE AREA BY THURSDAY...WHEN WINDS ALOFT WILL STRENGTHEN
AND A LEE TROUGH WILL DEVELOP AS A BROAD UPPER LEVEL LOW PRESSURE
SYSTEM DROPS INTO THE GREAT BASIN. MODELS PASS THIS UPPER LOW
NORTH OF NEW MEXICO DURING THE LATER PART OF THE WEEK...WITH WIND
AND FIRE WEATHER CONCERNS POSSIBLE ACROSS MUCH OF NORTHERN AND
CENTRAL NM.
44
&&
.AVIATION...
AN AVIATION WEATHER WARNING IS IN EFFECT FOR KABQ FROM 4PM-7PM WHEN
GUSTS TO AROUND 35 KNOTS ARE EXPECTED ALONG WITH SOME BLDU. STRONG
SW WINDS WILL AFFECT WESTERN NM AND THE EAST SLOPES OF THE CENTRAL
MT CHAIN WHERE GUSTS UP TO 45 KNOTS WILL CONTINUE THRU SUNSET THEN
DIMINISH BELOW 20 KNOTS. A PACIFIC COLD FRONT WILL SLIDE FROM WEST
TO EAST ACROSS CENTRAL AND WESTERN NM BETWEEN 9PM THIS EVENING AND
6AM MONDAY SHIFTING WINDS QUICKLY TO THE WNW BEHIND THE FRONT. A
BACK DOOR COLD FRONT WILL MOVE SW INTO THE NE PLAINS AROUND 15Z
MONDAY. PRECIP WILL DEVELOP RAPIDLY OVER NORTHERN AND CENTRAL NM
AFTER 21Z AS THE TWO FRONTS COLLIDE OVER CENTRAL NM. SITES SUCH AS
KLVS AND KSAF MAY REACH ALTERNATE MINIMUMS FOR CIGS AND VSBYS BY
LATE IN THE AFTERNOON FROM RAIN..SNOW...AND THUNDER.
NEXT AVIATION DISCUSSION SCHEDULED FOR 09Z. GUYER
&&
.FIRE WEATHER...
RED FLAG WARNING CONDITIONS ARE VERIFYING ACROSS MOST OF THE AREA.
SINGLE DIGIT RH VALUES...SW WIND GUSTS OF 35 TO 45 MPH...WELL ABOVE
NORMAL TEMPS...AND MODERATELY STRONG INSTABILITY WILL CONTINUE INTO
THE EARLY EVENING HOURS AHEAD OF A PACIFIC COLD FRONT APPROACHING
FROM THE WEST. WINDS WILL SHIFT DRAMATICALLY TO THE WEST BEGINNING
ACROSS WESTERN NM AROUND 9PM THEN ACROSS THE CENTRAL MT CHAIN THRU
6AM MONDAY. MAX RH RECOVERIES WILL IMPROVE CONSIDERABLY OVER WESTERN
NM TONIGHT BEHIND THE FRONT WITH VALUES FROM 60-80 PCT. MEANWHILE...
A BACK DOOR COLD FRONT WILL MOVE SW INTO THE FAR NE PLAINS AND NE
HIGHLANDS AFTER 6AM MONDAY.
THE CURRENT UPPER WAVE OVER THE GREAT BASIN WILL CLOSE OFF OVER
CENTRAL NM MONDAY AND COMBINE WITH THE TWO COLD FRONTS COLLIDING
OVER CENTRAL NM. WIDESPREAD RAIN/SNOW WILL DEVELOP RAPIDLY MONDAY
AFTERNOON OVER NORTH CENTRAL NM THEN SPREAD INTO THE SURROUNDING
VALLEYS AND PLAINS THRU MONDAY NIGHT. WIDESPREAD WETTING RAIN AND
POTENTIALLY HEAVY MT SNOW ACCUMULATIONS ARE POSSIBLE WITH THIS
STORM. VENT RATES WILL STILL BE VERY GOOD TO EXCELLENT EARLY ON
MONDAY THEN DETERIORATE RAPIDLY THROUGH THE AFTERNOON. RECOVERIES
THRU TUESDAY MORNING WILL BE EXCELLENT ACROSS MUCH OF NORTH CENTRAL
AND EASTERN NM UNDER WIDESPREAD RAIN/SNOW. MAX TEMPS WILL TREND
DRAMATICALLY COLDER MONDAY WITH READINGS ACTUALLY WELL BELOW NORMAL
IN MOST AREAS.
COMPUTER MODELS SHOW THE UPPER STORM SYSTEM HOLDING ONTO NM THRU
TUESDAY BEFORE EJECTING EAST INTO THE PLAINS STATES WEDNESDAY. COOL
TEMPS...SCATTERED RAIN/SNOW...AND SIGNIFICANTLY HIGHER HUMIDITY
VALUES WILL CONTINUE THRU THIS PERIOD.
A WEAK RIDGE WILL DEVELOP OVER THE AREA WEDNESDAY AND THEN ZONAL
FLOW RECOVERS VERY QUICKLY BY THURSDAY. GUSTY WINDS AND A POTENT
DRY SLOT AHEAD OF THE NEXT UPPER WAVE DEVELOPING WITHIN THE GREAT
BASIN WILL INCREASE THE POTENTIAL FOR CRITICAL FIRE WX CONDITIONS
ONCE AGAIN FOR AN EXTENDED PERIOD FROM THURSDAY THRU SATURDAY.
GUYER
&&
.PRELIMINARY POINT TEMPS/POPS UPDATE...
FARMINGTON...................... 32 57 35 58 / 10 30 10 10
DULCE........................... 25 52 28 54 / 20 50 30 20
CUBA............................ 28 47 28 49 / 10 50 50 30
GALLUP.......................... 25 51 28 56 / 10 20 20 10
EL MORRO........................ 23 47 26 53 / 10 30 30 10
GRANTS.......................... 25 51 20 55 / 0 30 30 20
QUEMADO......................... 28 49 28 57 / 0 20 20 10
GLENWOOD........................ 28 59 34 66 / 0 0 5 0
CHAMA........................... 29 47 24 48 / 30 60 50 40
LOS ALAMOS...................... 39 51 31 48 / 5 50 60 40
PECOS........................... 36 51 30 46 / 0 70 80 50
CERRO/QUESTA.................... 29 50 22 45 / 10 50 70 50
RED RIVER....................... 31 38 19 36 / 10 70 80 60
ANGEL FIRE...................... 28 41 17 37 / 5 70 90 70
TAOS............................ 28 52 25 47 / 5 40 60 40
MORA............................ 32 46 27 42 / 5 70 90 60
ESPANOLA........................ 31 57 30 52 / 5 40 50 30
SANTA FE........................ 37 52 31 47 / 5 50 70 40
SANTA FE AIRPORT................ 35 55 31 50 / 0 40 60 40
ALBUQUERQUE FOOTHILLS........... 43 55 34 55 / 0 40 50 30
ALBUQUERQUE HEIGHTS............. 41 56 36 55 / 0 40 50 30
ALBUQUERQUE VALLEY.............. 40 58 31 57 / 0 30 40 30
ALBUQUERQUE WEST MESA........... 39 57 32 56 / 5 30 40 30
LOS LUNAS....................... 36 58 34 58 / 5 30 30 30
RIO RANCHO...................... 39 57 35 56 / 0 30 50 30
SOCORRO......................... 39 59 36 61 / 0 5 20 20
SANDIA PARK/CEDAR CREST......... 34 48 22 48 / 0 60 70 40
TIJERAS......................... 36 52 32 51 / 0 50 70 30
MORIARTY/ESTANCIA............... 35 52 29 50 / 0 40 60 40
CLINES CORNERS.................. 34 47 28 44 / 0 60 80 40
GRAN QUIVIRA.................... 36 49 32 51 / 0 20 50 30
CARRIZOZO....................... 35 55 32 54 / 0 5 30 10
RUIDOSO......................... 37 47 31 46 / 0 10 30 20
CAPULIN......................... 42 48 28 42 / 0 60 90 60
RATON........................... 37 53 31 46 / 0 70 80 60
SPRINGER........................ 35 56 29 48 / 0 70 80 60
LAS VEGAS....................... 35 50 30 43 / 0 70 80 50
CLAYTON......................... 45 58 32 48 / 0 20 60 50
ROY............................. 40 56 31 47 / 0 30 60 50
CONCHAS......................... 42 67 35 55 / 0 30 60 40
SANTA ROSA...................... 44 63 36 54 / 0 40 60 30
TUCUMCARI....................... 46 67 36 54 / 0 20 50 40
CLOVIS.......................... 45 66 37 55 / 0 20 30 20
PORTALES........................ 45 67 39 58 / 0 10 30 20
FORT SUMNER..................... 43 65 38 57 / 0 20 40 20
ROSWELL......................... 46 69 41 60 / 0 5 20 10
PICACHO......................... 42 62 37 56 / 0 5 20 10
ELK............................. 40 57 34 54 / 0 5 20 10
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 11 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES...NMZ103-104-106>108.
WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY AFTERNOON
FOR THE FOLLOWING ZONES...NMZ510-512>515-521>523-527>529.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1030 PM EDT SUN APR 1 2012
.SYNOPSIS...
DRY WEATHER WILL CONTINUE THROUGH TONIGHT AS HIGH PRESSURE RIDGES
DOWN FROM THE NORTH. A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE
AREA MONDAY. UNSETTLED CONDITIONS WILL RETURN BY MID WEEK AS A LOW
PRESSURE SYSTEM APPROACHES THE EASTERN CAROLINAS. COOL AND DRY
HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION LATE IN THE
WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1030 PM SUNDAY...CLUSTER OF SHOWERS AND ISOLATED TSTMS
ASSOCIATED WITH AN UPPER LEVEL VORT...HAS NEARLY TRACKED ACROSS THE
STATE OF SC THIS EVENING BEFORE FINALLY ENCOUNTERING A STABILIZING
ATMOSPHERE AFTER SUNSET. IT IS ALSO ENCOUNTERING A SHALLOW STABLE
LOW LEVEL MARINE AIR BEHIND A SEA BREEZE THAT TRACKED A GOOD 50
MILES INLAND BEFORE THE CIRCULATION WAS INTERRUPTED BY YOU GUESS
IT...SUNSET. OVERALL...CONVECTION HAS NEARLY DIED OUT ENTIRELY WITH
ONLY A FEW SHOWERS TEMPORARILY LEFT ACROSS SOUTHERN SC AT THE
MOMENT. HAVE REMOVED ALL POPS FOR THIS EVENING...AND THE OVERNIGHT
PERIOD. CONVECTION DROPPING SOUTHWARD ASSOCIATED WITH A SFC COLD
FRONT WILL LIKELY HOLD OFF UNTIL AFTER SEVERAL HRS AFTER MONDAYS
SUNRISE AT WHICH TIME THE ATM WILL BEGIN TO DESTABILIZE. CURRENT MIN
TEMP FCST LOOKS AOK. NOT EXPECTING FOG TO BE A PROBLEM OVERNITE WITH
A SFC SW-W WIND REMAINING ACTIVE OVERNIGHT. LATEST MIN FCST LOOKS
AOK AND C NO REASON TO ALTER.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...BACK DOOR TYPE COLD FRONT WILL BE ON THE
DOORSTEP OF THE NORTHERN PART OF THE CWA AT THE START OF THE PERIOD.
THIS FRONT WILL DROP SOUTH THROUGH MONDAY IN RESPONSE TO A NORTHERN
STREAM 500MB S/W TROUGH PUSHING SE OFF THE MID-ATLANTIC COAST. TWO
QUESTIONS PERSIST ABOUT THIS FROPA...WILL IT PUSH ALL THE WAY
THROUGH THE CWA...AND WILL IT BE ASSOCIATED WITH TSTMS.
AS THE FRONT PUSHES SOUTH...IT WILL ENCOUNTER THE LEADING EDGE OF A
STRONG UPPER RIDGE BUILDING EASTWARD FROM THE GREAT PLAINS. RIDGES
TEND TO WIN THESE PLACEMENT BATTLES...BUT GUIDANCE CONTINUES TO
INSIST THAT FROPA WILL TAKE PLACE THROUGH THE ENTIRE CWA. S/W
DRIVING IT IS FAIRLY POTENT...AND RIDGE IS ONLY BEGINNING TO MOVE
EAST...SO WILL CONTINUE TO SHOW FROPA THROUGH THE AREA MONDAY. AT
THE SAME TIME...DECENT CONVERGENCE ALONG THE BOUNDARY INTO RICH
THETA-E AIR SHOULD SUPPORT SOME SHOWERS AND ISOLATED TSTMS. BEST
CHANCE LOOKS TO BE ACROSS SOUTHERN ZONES WHERE HEATING AND HIGHER
PWATS WILL SUPPORT MORE PRECIP...BUT WEAK NVA AT 500MB AND
CONFLUENCE AT JET LEVEL WILL INHIBIT MUCH IN THE WAY OF CONVECTION.
AM COMFORTABLE WITH THE INHERITED SCHC OF TSTMS...BUT EXPECT VERY
LIGHT PRECIP AS EVIDENCED BY HPC QPF OF ONLY A FEW HUNDREDTHS OF AN
INCH.
TEMPS MONDAY WILL BE TRICKY AS WELL...SINCE 850MB TEMPS WILL FALL
THROUGH THE DAY AND THERE COULD BE QUITE A TEMP GRADIENT FROM SW TO
NE. TEMPS ONLY IN THE UPPER 70S FAR NE COASTAL ZONES...RISING INTO
THE UPPER 80S IN THE PEE DEE REGION OF SC. MINS RANGE FROM AROUND 50
FAR NE TO AROUND 60 IN THE SOUTH.
WEAK CAA ON TUESDAY WILL KEEP TEMPS AROUND CLIMO UNDER PARTLY TO
MOSTLY CLOUDY SKY CONDITIONS DUE TO MOISTURE TRAPPED BENEATH THE
FRONTAL INVERSION. COLD FRONT SOUTH OF THE AREA TUESDAY WILL STALL
AND WAVER BACK NORTH...WHILE INCREASING ISENTROPIC LIFT WILL SUPPORT
INCREASING SHOWERS ACROSS SOUTHERN ZONES...BUT ONCE AGAIN WITH
LIMITED QPF. MINS TUESDAY NIGHT STAY ABOVE 60 ACROSS MOST OF THE
AREA AS HIGH PRESSURE DRIFTS OFFSHORE CREATING WARM SOUTHERLY FLOW
AND CLOUD COVER.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...MAIN FOCUS FOR THE EXTENDED
REMAINS ON THE MID LEVEL SYSTEM NOW MOVING/DIGGING ACROSS THE
WESTERN U.S. AND ITS MOVEMENT/EVOLUTION THROUGH LATE WEEK. HPC
CONTINUES TO FAVOR THE ENSEMBLE MEAN OF THE ECMWF WHICH IS SLIGHTLY
MORE AMPLIFIED AND SLOWER AND THE GEFS MEAN. I HAVE MADE FEW
ADJUSTMENTS IN POPS OTHER THAN TO DECREASE INCREMENTALLY VALUES FOR
THURSDAY AS THE MID LEVEL RIDGE AMPLIFIES ACROSS THE AREA JUST
BEFORE THE MAIN SYSTEM MOVES ACROSS EARLY FRIDAY. FOR WEDNESDAY A
BACKDOOR FRONT CONTINUES TO WARRANT CHANCE POPS. SATURDAY AND SUNDAY
REMAIN DRY FOR NOW.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...CONVECTION WELL WEST OF THE REGION ON THE TAIL END OF A
WEAK CLIPPER LIKE SYSTEM MOVING THROUGH THE MID ATLANTIC. THIS
CONVECTION WILL WEAKEN AS IT APPROACHES THE CWA...WITH LITTLE OR NO
AVIATION IMPACT. LOW CONFIDENCE ON A BRIEF IFR STRATUS LAYER BEFORE
SUNRISE. LOOK FOR A WIND SHIFT TO THE NORTH DURING THE DAY MONDAY AS
LOW PRESSURE DRAGS A FRONT THROUGH THE REGION. THERE WILL BE
ISOLATED CONVECTION ALONG AND AHEAD OF THE FRONT...NOT ENOUGH
COVERAGE TO ADD IN THE TAFS. GUSTY NORTH WINDS WILL CONTINUE THROUGH
MONDAY AFTERNOON...DIMINISHING SOMEWHAT BY EARLY EVENING AS THEY
VEER TO THE NORTHEAST.
EXTENDED OUTLOOK...LOW CONFIDENCE SHOWERS/ISOLATED THUNDERSTORMS
MONDAY NIGHT AND TUESDAY. SCATTERED CONVECTION POSSIBLE WEDNESDAY
WITH A BETTER CHANCE FOR PRECIP ON THURSDAY INTO EARLY FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SUNDAY...WINDS CONTINUE TO VEER TO THE SW LATE THIS
EVENING AND HAVE INCREASED TO 10-15 KT. PROGGED BY HRRR AND NAM
MODELS...SW-W WINDS WILL FURTHER INCREASE OVERNIGHT TO 15 TO 20 KT
THRU THE PRE-DAWN HRS OF MONDAY. WIND DRIVEN WAVES WILL DOMINATE
SIGNIFICANT SEAS WITH SEAS BUILDING TO 2 TO 4 FT ...EXCEPT 3 TO 5 FT
ACROSS THE WATERS OFF CAPE FEAR SOUTH TO LITTLE RIVER INLET DUE TO
THE LONGER SW-W FETCH. SCEC THRESHOLDS MAY BE MET FOR THE JUST THE
AFOREMENTIONED WATERS AND WILL MONITOR FOR POSSIBLE ISSUANCE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...COLD FRONT CROSSES THE WATERS DURING
MONDAY...TURNING WINDS FROM THE WEST AT 10-15 KTS EARLY...TO THE NE
AT 10-15 KTS BY MONDAY NIGHT. THIS TRANSITION WILL OCCUR FIRST
ACROSS THE NORTHERN WATERS...AND LATER IN THE DAY ACROSS THE SOUTH.
WAVE SPECTRUM WILL CONSIST OF A LOW AMPLITUDE ESE 1FT/9SEC SWELL AND
A BUILDING 3-4FT/5SEC NE WIND WAVE. THESE WILL COMBINE TO CREATE
SEAS OF 2-3 FT...SLIGHTLY LOWER IN THE SHADOWED REGION SW OF FRYING
PAN SHOALS. HIGH PRESSURE DRIFTS OFFSHORE TUESDAY ALLOWING WINDS TO
SLOWLY VEER TO THE SOUTH AS RETURN FLOW SETS UP. SPEEDS OF ONLY
AROUND 10 KTS WILL PRODUCE CONTINUED 2-3 FT SEAS...COMPRISED OF A
ENE WIND CHOP EARLY...BECOMING A SW WIND CHOP LATE.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 300 PM SUNDAY...EXPECT A SOUTHWEST FLOW INITIALLY AS BERMUDA
HIGH PRESSURE PREVAILS AND A FRONT LURKS OFF TO THE NORTH WITH A
PIEDMONT TROUGH AS WELL. THE FRONT MOVES ACROSS LATE WEDNESDAY INTO
THURSDAY MORNING AS MOST IF NOT ALL WATERS WILL SEE NORTHEASTERLY
WINDS BY 1200 UTC THURSDAY. UNCERTAINTY REMAINS FOR THE REMAINDER OF
THE FORECAST AS SURFACE PRESSURE PATTERN SHOWS LOW PRESSURE DROPPING
TO THE SOUTH AND WINDS TURNING TO THE EAST. GOOD THING IS THE
STRENGTH OF THE LOW SHOULD REMAIN RELATIVELY WEAK SO DO NOT
ANTICIPATE ANY HEADLINES. THE STRONGEST WINDS SHOULD OCCUR WEDNESDAY
WITH 10-15 KNOTS. WAVEWATCH SEAS ARE REFLECTIVE OF THE WINDS AT
LEAST INITIALLY. HAD TO SCALE BACK LATER IN THE PERIOD BUT OVERALL
SEAS REMAIN BELOW FLAG CRITERIA AS WELL.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
730 PM EDT SUN APR 1 2012
.SYNOPSIS...
DRY WEATHER WILL CONTINUE THROUGH TONIGHT AS HIGH PRESSURE RIDGES
DOWN FROM THE NORTH. A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE
AREA MONDAY. UNSETTLED CONDITIONS WILL RETURN BY MID WEEK AS A LOW
PRESSURE SYSTEM APPROACHES THE EASTERN CAROLINAS. COOL AND DRY
HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION LATE IN THE
WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 730 PM SUNDAY...CLUSTER OF SHOWERS AND ISOLATED TSTMS
ASSOCIATED WITH AN UPPER LEVEL VORT...TRACKED ACROSS THE APPALACHIAN
MOUNTAINS EARLIER TODAY...AND STILL HAS SOME JUICE IE. AVAILABLE
CAPE ALTHOUGH NOT MUCH...AHEAD OF IT TO KEEP IT SUSTAINED ATLEAST
UNTIL SUNSET. HAVE UPDATED POPS AND CLOUD CONDITIONS ACROSS THE FA
IN AN EXTRAPOLATION OF THIS PRECIP ACTIVITY REACHING THE FA AND
LIKELY SEEING ITS DEMISE DUE TO A LOSS OF INSOLATION AND AVAILABLE
INSTABILITY PER LATEST HRRR MODEL RUNS. FOR THE PRE-DAWN HRS OF
MONDAY LEADING TO SUNRISE...HAVE INDICATED JUST A SLIGHT CHANCE OF
CONVECTION ACROSS THE EXTREME NORTHERN PORTIONS OF THE ILM CWA AS A
BACKDOOR COLD FRONT DROPS SOUTHWARD AND NEARS THE ILM CWA. CURRENT
MIN TEMP FCST LOOKS AOK. WITH ANY TWEAKS NEEDED WILL BE A 1 TO 2
DEGREES UPWARD ADJUSTMENT AS DEWPOINTS RECOVER INTO THE 50S AND INTO
THE 60S ACROSS SOUTHERN PORTIONS OF THE ILM CWA.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...BACK DOOR TYPE COLD FRONT WILL BE ON THE
DOORSTEP OF THE NORTHERN PART OF THE CWA AT THE START OF THE PERIOD.
THIS FRONT WILL DROP SOUTH THROUGH MONDAY IN RESPONSE TO A NORTHERN
STREAM 500MB S/W TROUGH PUSHING SE OFF THE MID-ATLANTIC COAST. TWO
QUESTIONS PERSIST ABOUT THIS FROPA...WILL IT PUSH ALL THE WAY
THROUGH THE CWA...AND WILL IT BE ASSOCIATED WITH TSTMS.
AS THE FRONT PUSHES SOUTH...IT WILL ENCOUNTER THE LEADING EDGE OF A
STRONG UPPER RIDGE BUILDING EASTWARD FROM THE GREAT PLAINS. RIDGES
TEND TO WIN THESE PLACEMENT BATTLES...BUT GUIDANCE CONTINUES TO
INSIST THAT FROPA WILL TAKE PLACE THROUGH THE ENTIRE CWA. S/W
DRIVING IT IS FAIRLY POTENT...AND RIDGE IS ONLY BEGINNING TO MOVE
EAST...SO WILL CONTINUE TO SHOW FROPA THROUGH THE AREA MONDAY. AT
THE SAME TIME...DECENT CONVERGENCE ALONG THE BOUNDARY INTO RICH
THETA-E AIR SHOULD SUPPORT SOME SHOWERS AND ISOLATED TSTMS. BEST
CHANCE LOOKS TO BE ACROSS SOUTHERN ZONES WHERE HEATING AND HIGHER
PWATS WILL SUPPORT MORE PRECIP...BUT WEAK NVA AT 500MB AND
CONFLUENCE AT JET LEVEL WILL INHIBIT MUCH IN THE WAY OF CONVECTION.
AM COMFORTABLE WITH THE INHERITED SCHC OF TSTMS...BUT EXPECT VERY
LIGHT PRECIP AS EVIDENCED BY HPC QPF OF ONLY A FEW HUNDREDTHS OF AN
INCH.
TEMPS MONDAY WILL BE TRICKY AS WELL...SINCE 850MB TEMPS WILL FALL
THROUGH THE DAY AND THERE COULD BE QUITE A TEMP GRADIENT FROM SW TO
NE. TEMPS ONLY IN THE UPPER 70S FAR NE COASTAL ZONES...RISING INTO
THE UPPER 80S IN THE PEE DEE REGION OF SC. MINS RANGE FROM AROUND 50
FAR NE TO AROUND 60 IN THE SOUTH.
WEAK CAA ON TUESDAY WILL KEEP TEMPS AROUND CLIMO UNDER PARTLY TO
MOSTLY CLOUDY SKY CONDITIONS DUE TO MOISTURE TRAPPED BENEATH THE
FRONTAL INVERSION. COLD FRONT SOUTH OF THE AREA TUESDAY WILL STALL
AND WAVER BACK NORTH...WHILE INCREASING ISENTROPIC LIFT WILL SUPPORT
INCREASING SHOWERS ACROSS SOUTHERN ZONES...BUT ONCE AGAIN WITH
LIMITED QPF. MINS TUESDAY NIGHT STAY ABOVE 60 ACROSS MOST OF THE
AREA AS HIGH PRESSURE DRIFTS OFFSHORE CREATING WARM SOUTHERLY FLOW
AND CLOUD COVER.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...MAIN FOCUS FOR THE EXTENDED
REMAINS ON THE MID LEVEL SYSTEM NOW MOVING/DIGGING ACROSS THE
WESTERN U.S. AND ITS MOVEMENT/EVOLUTION THROUGH LATE WEEK. HPC
CONTINUES TO FAVOR THE ENSEMBLE MEAN OF THE ECMWF WHICH IS SLIGHTLY
MORE AMPLIFIED AND SLOWER AND THE GEFS MEAN. I HAVE MADE FEW
ADJUSTMENTS IN POPS OTHER THAN TO DECREASE INCREMENTALLY VALUES FOR
THURSDAY AS THE MID LEVEL RIDGE AMPLIFIES ACROSS THE AREA JUST
BEFORE THE MAIN SYSTEM MOVES ACROSS EARLY FRIDAY. FOR WEDNESDAY A
BACKDOOR FRONT CONTINUES TO WARRANT CHANCE POPS. SATURDAY AND SUNDAY
REMAIN DRY FOR NOW.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...CONVECTION WELL WEST OF THE REGION ON THE TAIL END OF A
WEAK CLIPPER LIKE SYSTEM MOVING THROUGH THE MID ATLANTIC. THIS
CONVECTION WILL WEAKEN AS IT APPROACHES THE CWA...WITH LITTLE OR NO
AVIATION IMPACT. LOW CONFIDENCE ON A BRIEF IFR STRATUS LAYER BEFORE
SUNRISE. LOOK FOR A WIND SHIFT TO THE NORTH DURING THE DAY MONDAY AS
LOW PRESSURE DRAGS A FRONT THROUGH THE REGION. THERE WILL BE
ISOLATED CONVECTION ALONG AND AHEAD OF THE FRONT...NOT ENOUGH
COVERAGE TO ADD IN THE TAFS. GUSTY NORTH WINDS WILL CONTINUE THROUGH
MONDAY AFTERNOON...DIMINISHING SOMEWHAT BY EARLY EVENING AS THEY
VEER TO THE NORTHEAST.
EXTENDED OUTLOOK...LOW CONFIDENCE SHOWERS/ISOLATED THUNDERSTORMS
MONDAY NIGHT AND TUESDAY. SCATTERED CONVECTION POSSIBLE WEDNESDAY
WITH A BETTER CHANCE FOR PRECIP ON THURSDAY INTO EARLY FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM SUNDAY...WINDS CONTINUE TO VEER TO THE S AND SW THIS
EVENING...AND ARE PROGGED BY HRRR AND NAM MODELS TO INCREASE TO SW-W
15 TO 20 KT THRUOUT DURING THE PRE-DAWN HRS OF MONDAY. WIND DRIVEN
WAVES WILL DOMINATE SIGNIFICANT SEAS WITH SEAS BUILDING TO 2 TO 4 FT
...EXCEPT UP TO 5 FT ACROSS THE WATERS OFF CAPE FEAR SOUTH TO LITTLE
RIVER INLET DUE TO THE LONGER SW-W FETCH. SCEC THRESHOLDS MAY BE MET
FOR THE JUST AFOREMENTIONED WATERS AND WILL MONITOR FOR POSSIBLE
ISSUANCE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...COLD FRONT CROSSES THE WATERS DURING
MONDAY...TURNING WINDS FROM THE WEST AT 10-15 KTS EARLY...TO THE NE
AT 10-15 KTS BY MONDAY NIGHT. THIS TRANSITION WILL OCCUR FIRST
ACROSS THE NORTHERN WATERS...AND LATER IN THE DAY ACROSS THE SOUTH.
WAVE SPECTRUM WILL CONSIST OF A LOW AMPLITUDE ESE 1FT/9SEC SWELL AND
A BUILDING 3-4FT/5SEC NE WIND WAVE. THESE WILL COMBINE TO CREATE
SEAS OF 2-3 FT...SLIGHTLY LOWER IN THE SHADOWED REGION SW OF FRYING
PAN SHOALS. HIGH PRESSURE DRIFTS OFFSHORE TUESDAY ALLOWING WINDS TO
SLOWLY VEER TO THE SOUTH AS RETURN FLOW SETS UP. SPEEDS OF ONLY
AROUND 10 KTS WILL PRODUCE CONTINUED 2-3 FT SEAS...COMPRISED OF A
ENE WIND CHOP EARLY...BECOMING A SW WIND CHOP LATE.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 300 PM SUNDAY...EXPECT A SOUTHWEST FLOW INITIALLY AS BERMUDA
HIGH PRESSURE PREVAILS AND A FRONT LURKS OFF TO THE NORTH WITH A
PIEDMONT TROUGH AS WELL. THE FRONT MOVES ACROSS LATE WEDNESDAY INTO
THURSDAY MORNING AS MOST IF NOT ALL WATERS WILL SEE NORTHEASTERLY
WINDS BY 1200 UTC THURSDAY. UNCERTAINTY REMAINS FOR THE REMAINDER OF
THE FORECAST AS SURFACE PRESSURE PATTERN SHOWS LOW PRESSURE DROPPING
TO THE SOUTH AND WINDS TURNING TO THE EAST. GOOD THING IS THE
STRENGTH OF THE LOW SHOULD REMAIN RELATIVELY WEAK SO DO NOT
ANTICIPATE ANY HEADLINES. THE STRONGEST WINDS SHOULD OCCUR WEDNESDAY
WITH 10-15 KNOTS. WAVEWATCH SEAS ARE REFLECTIVE OF THE WINDS AT
LEAST INITIALLY. HAD TO SCALE BACK LATER IN THE PERIOD BUT OVERALL
SEAS REMAIN BELOW FLAG CRITERIA AS WELL.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
346 PM CDT SAT MAR 31 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...
THE MAIN PROBLEM IN THE SHORT TERM WILL BE FIRE WEATHER HIGHLIGHTS
ON SUNDAY AND SUNDAY EVENING. UTILIZED A MODEL BLEND. THE NAM/GFS
WERE ON THE PROGRESSIVE SIDE WHILE THE ECMWF WAS THE SLOWEST OF
THE DETERMINISTIC MODELS. A BLEND SHOULD YIELD A FAVORABLE SOLUTION.
TONIGHT...WEAK HIGH PRESSURE OVER THE AREA WILL MOVE EAST AS LOW
PRESSURE CONTINUES TO BUILD OVER EASTERN MONTANA. NEARLY FULL SUN
ACROSS WESTERN AND CENTRAL NORTH DAKOTA THIS AFTERNOON. WE WILL
SEE CLOUDS INCREASE IN THE WEST BY LATE AFTERNOON AS WARM
ADVECTION SPREADS EAST ACROSS NORTHERN AND CENTRAL NORTH DAKOTA.
MODELS BRING SOME SPOTTY QPF ACROSS THE NORTH TONIGHT. THE LATEST
HIGH RESOLUTION RUC SHOWS RETURNS MOVING WEST TO EAST ACROSS THE
NORTH THROUGH 06Z BUT DOES NOT INDICATE ANY MEASURED
PRECIPITATION. LATE TONIGHT THE ECMWF SHOWS SOME HEAVIER QPF OVER
THE NORTH CENTRAL...SO CANNOT RULE OUT SOME MEASURABLE
PRECIPITATION. ENDED UP KEEPING A MENTION OF SPRINKLES THIS
EVENING AND A SLIGHT CHANCE OF SHOWERS AFTER MIDNIGHT. ANY
ACCUMULATIONS ARE EXPECTED TO BE INSIGNIFICANT.
SUNDAY...A COLD FRONT WILL MOVE THROUGH WESTERN AND CENTRAL NORTH
DAKOTA. THE FRONT SHOULD MOVE INTO THE WEST AROUND MIDDAY AND
TRACK ACROSS THE LOCAL AREA BY LATE SUNDAY EVENING. THERMAL
RIDGING AHEAD OF THE FRONT SHOULD ALLOW FOR RECORD BREAKING WARMTH
ACROSS MUCH OF CENTRAL NORTH DAKOTA. SHOWN BELOW ARE THE FORECAST
AND RECORD HIGHS FOR SUNDAY FOR SELECT LOCATIONS ACROSS THE AREA.
SITE FORECAST RECORD YEAR
DICKINSON 79 74 1964
MINOT 76 72 1928
BISMARCK 84 75 1976
JAMESTOWN 78 78 1907
WILLISTON 72 72 1991
.SUNDAY NIGHT...WINDS WILL DIMINISH DURING THE EVENING. WITH UPPER
LEVEL ENERGY SPLITTING AND TRACKING NORTH AND SOUTH OF THE
CWA...AND SUBSIDENCE BEHIND THE FRONTAL BOUNDARY...ANY
PRECIPITATION IS EXPECTED TO BE LIGHT. THE ECMWF IS A LITTLE
WETTER...DUE TO A DEEPER TROUGH IN THE NORTHERN STREAM PUSHING
INTO THE NORTHERN PLAINS. FOR NOW WILL KEEP THINGS DRY.
AGAIN...ANY AMOUNTS WOULD BE LIGHT.
.LONG TERM...MONDAY THROUGH FRIDAY NIGHT...
AN UPPER TROUGH APPROACHES VIA THE NORTHERN STREAM MONDAY AND MODEL
DISCREPANCIES IN THE PRECIPITATION FIELD ARE FAIRLY SIGNIFICANT. THE
THE NAM AND GFS ARE SIMILAR IN GENERATING A NARROW STRIP OF VERY
LIGHT SHOWERS BETWEEN BISMARCK AND JAMESTOWN MONDAY MORNING. THE GEM
IS COMPLETELY DRY...WHILE THE ECMWF IS ADVERTISING WIDESPREAD LIGHT
RAIN THROUGHOUT THE DAY. THE MAIN DIFFERENCE LOOKS TO BE THE ECMWF
HOLDING BACK THE ENTIRE TROUGH FURTHER WEST ALLOWING MORE MOISTURE
FEED INTO NORTH DAKOTA VERSUS THE OTHER MODELS. FOR NOW HAVE
MAINTAINED A SLIGHT CHANCE OF SHOWERS FOR CENTRAL NORTH DAKOTA
MONDAY UNTIL BETTER AGREEMENT IS REACHED. IT WILL BE MUCH COOLER
MONDAY...BY 20 TO 25 DEGREES THAN SUNDAYS HIGH TEMPERATURES. THAT
ESSENTIALLY PUTS HIGHS IN THE LOWER TO MID 50S ACROSS WESTERN AND
CENTRAL NORTH DAKOTA MONDAY.
FOR TUESDAY THROUGH THURSDAY...TEMPERATURES BEGIN TO REBOUND THROUGH
THE PERIOD AS DRY AND WARMER WEATHER DEVELOP VIA A REX BLOCK/HIGH
OVER LOW PATTERN TRANSITIONING ACROSS THE NORTHERN PLAINS. EXPECT
PLENTY OF SUNSHINE...WITH THE WARMEST AIR...HIGHS AROUND
70F...ARRIVING THURSDAY AHEAD OF A COLD FRONT. A CHANCE OF SHOWERS
ARE FORECAST THURSDAY NIGHT THROUGH FRIDAY NIGHT AS A STRONG
BAROCLINIC ZONE SLOWLY MOVES FROM WEST TO EAST DURING THE DAY
FRIDAY.
FOR FRIDAY NIGHT INTO SATURDAY...THE GFS AND ECMWF IN GOOD AGREEMENT
WITH H85 TEMPS OF -4C TO -6C ACROSS CENTRAL AND NORTHERN NORTH
DAKOTA. BOUNDARY LAYER WINDS ARE ADVERTISED BETWEEN 30KT AND 40KT.
WILL NEED TO KEEP A CLOSE WATCH ON THIS FOR A POSSIBLE EARLY SPRING
SNOW/WIND EVENT.
&&
.AVIATION...THE LATEST SATELLITE IMAGERY SHOWS AN AREA OF SCT/BKN
LOW TO MID LEVEL CLOUDS BASED FROM 6500FT AGL TO 11000FT AGL. THIS
AREA WILL CONTINUE TO MOVE TOWARD KISN/KDIK/KMOT/KBIS THROUGH 00Z
SUNDAY. THIS IS ASSOCIATED WITH A WARM FRONT WHICH WILL MOVE THROUGH
OVERNIGHT. A VCSH IS WARRANTED OVER KISN AND KMOT TONIGHT. WINDS
WILL BECOME EAST TO SOUTHEAST WITH THE WARM FRONT OVERNIGHT AND
INCREASE TO AROUND 15KT. A COLD FRONT WILL THEN MOVE INTO THE
WESTERN AERODROMES KISN/KDIK AROUND 16Z SUNDAY. EXPECT A WIND SHIFT
TO THE WEST AND NORTHWEST AND INCREASING TO BETWEEN 20KT AND 30KT.
THE COLD FRONT WILL THEN SHIFT INTO CENTRAL NORTH DAKOTA...KMOT/KBIS
BY AROUND 21Z SUNDAY.
&&
.FIRE WEATHER...A COLD FRONT WILL PRODUCE GUSTY WEST TO NORTHWEST
WINDS AS IT MOVES THROUGH WESTERN AND CENTRAL NORTH DAKOTA ON
SUNDAY AND SUNDAY EVENING. A THICKNESS RIDGE AHEAD OF THE FRONT
COMBINED WITH COMPRESSIONAL HEATING ASSOCIATED WITH THE FRONT WILL
ALLOW TEMPERATURES TO RISE TO RECORD VALUES...AND ALLOW MINIMUM
HUMIDITIES TO DROP INTO THE TEENS IN THE AFTERNOON. FARTHER
WEST...TEMPERATURES WILL NOT WARM AS MUCH...BUT HUMIDITIES WILL
REMAIN QUITE LOW. FORECAST SOUNDINGS INDICATE SUSTAINED WINDS OF
AROUND 20 MPH WITH GUSTS UP TO 35 MPH ACROSS MOST OF WESTERN AND
CENTRAL NORTH DAKOTA. IT IS POSSIBLE WE COULD TRIM A FEW COUNTIES
IN THE NORTH AND EAST...FROM THE CURRENT WATCH...BUT WITH
UNCERTAINTY IN THE TIMING OF THE COLD FRONT...WILL ISSUE A RED
FLAG WARNING FOR THE SAME COUNTIES AS THE FIRE WEATHER WATCH. WE
DID EXTEND THE WARNING AN HOUR EARLIER TO CATCH THE STRONGER WINDS
COMING INTO THE WEST LATE IN THE MORNING...AND AN HOUR LATER TO
CATCH THE LOW HUMIDITIES AND BREEZY CONDITIONS HOLDING ON IN THE
EAST THROUGH MID EVENING. LATER SHIFTS CAN ALWAYS ADJUST AS
NEEDED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON CDT /11 AM MDT/ TO 10 PM CDT /9 PM
MDT/ SUNDAY FOR NDZ009>012-017>023-031>036-040>047-050.
&&
$$
SHORT TERM...TWH
LONG TERM/AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
210 PM EDT SAT MAR 31 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION TODAY...PROVIDING COOLER
AND DRIER WEATHER. A FRONTAL BOUNDARY WILL DROP INTO OHIO ON
SUNDAY OFFERING A CHANCE OF SHOWERS AND THUNDERSTORMS. THE THREAT
FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY PART OF
THE WORK WEEK WITH THE FRONT REMAINING ACROSS THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
31.12Z KILN RAOB SHOWED AMPLE LOW LEVEL MOISTURE TRAPPED BENEATH
RATHER STRONG INVERSION CENTERED AROUND 900MB. WEAK COLD ADVECTION
BELOW THE INVERSION WILL CONTINUE THROUGH MUCH OF THE
AFTERNOON...SO HAVING DOUBTS THE DEGREE OF CLEARING ANY LOCATION
WILL SEE. TIME-LAGGED RUC SOUNDINGS FROM THE LAST 6 OPERATIONAL
13KM RUNS DEFINITELY TRENDING ON HOLDING LOW LEVEL MOISTURE IN
LONGER. 31.12Z RUC 950-900MB LAYER HUMIDITIES DO IMPROVE FOR SOME
CLEARING AFTER 20Z...MOST LIKELY A MANIFESTATION OF MUCH DRIER AIR
ABOVE THIS LAYER ADVECTING IN ON WLY FLOW FROM ILLINOIS /WHERE
CLEARING TAKING PLACE/...WITH MIXING/EROSION LIKELY CHEWING SOME HOLES
IN THE THICK LOW LEVEL STRATUS INTO MID/LATE AFTERNOON. EVEN WITH
THAT...FELT PRUDENT BASED ON CURRENT TEMPS AND BLEND OF HI-RES
SHORT TERM GUIDANCE /HRRR...WRF...LAMP...RUC/ TO DROP AFTERNOON
HIGH TEMPERATURES BY A GOOD 3 TO 5 DEGREES. SHOULD SEE THE VSBYS
SLOWLY IMPROVE THROUGH THE REST OF THE MORNING...AND THIS IS
ALREADY TRENDING IN 31.12Z - 31.14Z OBS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
UPPER LEVEL RIDGE BUILDING ACRS THE NATIONS MID SECTION WITH NWRLY
FLOW DOMINATING AND SURFACE RIDGE BUILDING INTO THE OHIO VALLEY BY
SUNDAY MORNING. ANY LINGERING CLOUDS WILL GIVE WAY TO CLEARING EARLY
TONIGHT WITH SOME INCREASE IN HIGH LEVEL CLOUDS LATE. EXPECT LOWS
FROM NEAR 40 NE TO THE MID 40S SOUTH.
EMBEDDED S/W IN THE NWRLY FLOW TO DROP SE THRU THE EASTERN GREAT
LAKES SUNDAY/SUNDAY NIGHT. ASSOCIATED BACK DOOR COLD FRONT TO DROP
SOUTH INTO OHIO SUNDAY AFTN. WL CONTINUE CURRENT TREND ALLOWING FOR
CHC POPS NORTH AND ONLY MENTIONING A SLIGHT CHC ACRS THE FAR S
LATE. THE INFLUENCE OF WAA AND SOME SUNSHINE AHD OF THIS FRONT
WILL ALLOW TEMPS TO WARM TO READINGS ABOUT 15 DEGREES ABOVE
NORMAL.
NUMERICAL MODEL SOLNS DIFFER ON WHERE THE BACK DOOR FRONT STALLS
OUT. EXPECT THIS FRONTAL BOUNDARY TO PUSH SW AND LOSE ITS IDENTITY
AS THE UPPER LEVEL RIDGE BUILDS INTO THE MS VLY. WL ONLY CONT
SLIGHT CHC POPS INTO SUNDAY EVENING AND THEN ALLOW FOR A DRY
OVERNIGHT. THE REMNANTS OF THE FRONTAL BOUNDARY STALLING OUT AND
BEGINNING TO PUSH BACK NE ON MONDAY. WITH A LACK OF UPPER SUPPORT
AND BEST INSTBY REMAINING TO OUR WEST. WL LIMIT POPS TO SLIGHT CHC
OF THUNDERSTORMS MONDAY AFTN ACRS THE SW. EXPECT MONDAYS HIGH TEMPS
TO BE 10 TO 15 DEGREES ABOVE NORMAL...RANGING FROM THE LOWER 70S
NE TO THE UPPER 70S SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MID LEVEL RIDGING WILL BE IN PLACE ACROSS THE OHIO VALLEY BY 12Z
MONDAY MORNING WITH A WEAKENING COLD FRONT TO OUR SOUTH. THE MODELS
ARE TRYING TO SHOW THIS FRONT LIFTING BACK TO THE NORTHEAST AS A
WARM FRONT THROUGH THE DAY ON MONDAY...BUT DISAGREE ON BOTH THE
TIMING AND THE STRENGTH OF THIS FEATURE. WILL THEREFORE JUST HANG ON
TO SOME LOWER CHANCE POPS MONDAY INTO MONDAY NIGHT.
THE MODELS ARE ALSO HAVING A DIFFICULT TIME RESOLVING THE SHORT
WAVE ENERGY MOVING OUT OF THE ROCKIES THROUGH MID WEEK. BOTH THE 12Z
NAM AND 12Z CMC ARE TRYING TO CLOSE OFF A 5H LOW AS IT MOVES INTO
THE TENNESSEE VALLEY WEDNESDAY INTO THURSDAY. HOWEVER...THE 00Z
ECMWF KEEPS THE CLOSED LOW WELL BACK TO THE SOUTHWEST AND AS A
RESULT IS MUCH SLOWER TO BRING RIDGING IN FROM THE WEST THROUGH
LATE IN THE WEEK. IN FACT...THE 00Z ECMWF KEEPS A FAIRLY DEEP TROUGH
OVER THE NORTHEASTERN UNITED STATES THROUGH THE LONG TERM PERIOD. IT
LOOKS LIKE THERE WILL BE A DECENT CHANCE OF SHOWERS AND
THUNDERSTORMS BY TUESDAY AS THE INITIAL ENERGY APPROACHES BUT THE
QUESTION WILL BE HOW LONG ANY TREAT WILL HANG AROUND INTO THE MIDDLE
PART OF THE WEEK. WITH THE CLOSED LOW OF THE GFS/CMC WOULD THINK ANY
LINGERING PCPN WOULD MAINLY REMAIN TO OUR SOUTHWEST. MEANWHILE...ANY
PCPN PUSHING DOWN THE BACK SIDE OF THE TROUGH OF THE ECMWF SHOULD
MAINLY REMAIN TO OUR EAST. WILL THEREFORE GO WITH A DRY FORECAST
FROM MID WEEK ON...BUT CONFIDENCE IS NOT VERY HIGH WITH THIS
FORECAST. OF COURSE TEMPERATURES THROUGH THE WEEK WILL ALSO BE
AFFECTED BY ALL OF THIS. WILL GENERALLY GO WITH A BLEND OF
PERSISTENCE AND THE MODELS BUT PERHAPS TREND A LITTLE MORE TOWARD
THE COOLER ECMWF...WHICH WOULD KEEP TEMPERATURES FAIRLY SEASONABLE
THROUGH THE WEEK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
BKN-OVC MVFR CIGS WILL CONTINUE TO SLOWLY LIFT AND BEGIN
SCATTERING OUT BY EARLY EVENING. WILL BE A SLOW PROCESS
HOWEVER...AND CONFIDENCE IS NOT HIGH ON THESE CIGS BREAKING AS
SCHEDULED DUE TO AMPLE MOISTURE BELOW INVERSION. IF CLOUDS CAN
BREAK...THINK THERE IS GOOD POTENTIAL FOR FOG GIVEN COOL/MOIST LOW
LEVELS AND RECENT RAINS FOR MUCH OF THE AREA. WIND FIELD IS LIGHT
ESPECIALLY LATE EVENING THROUGH EARLY MORNING WITH SURFACE HIGH
OVERHEAD. HAVE MVFR VSBYS IN ALL TAF SITES WITH IFR VSBYS AT LUK. ON
SUNDAY...BOUNDARY LAYER FLOW TURNS SWLY AND INCREASES...BRINGING
WARMER/MORE UNSTABLE AIRMASS INTO THE REGION. CONTINUED MENTION OF
STORMS IN CVG TAF IN AFTERNOON GIVEN RAPID DESTABILIZATION...AND
OTHER TAF SITES WILL NEED TO MONITORED AS THE AFTERNOON PERIOD
WORKS INTO THE NEXT TAF ISSUANCE. WHILE COVERAGE OF STORMS SHOULD
REMAIN SCATTERED...A MID AFTERNOON TO MID EVENING PEAK IN COVERAGE
IS EXPECTED.
OUTLOOK...SCATTERED THUNDERSTORMS POSSIBLE MONDAY INTO TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...BINAU
SHORT TERM...AR
LONG TERM...JGL
AVIATION...BINAU
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1043 AM EDT SAT MAR 31 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION TODAY...PROVIDING COOLER
AND DRIER WEATHER. A FRONTAL BOUNDARY WILL DROP INTO OHIO ON
SUNDAY OFFERING A CHANCE OF SHOWERS AND THUNDERSTORMS. THE THREAT
FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EARLY PART OF
THE WORK WEEK WITH THE FRONT REMAINING ACROSS THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
31.12Z KILN RAOB SHOWED AMPLE LOW LEVEL MOISTURE TRAPPED BENEATH
RATHER STRONG INVERSION CENTERED AROUND 900MB. WEAK COLD ADVECTION
BELOW THE INVERSION WILL CONTINUE THROUGH MUCH OF THE
AFTERNOON...SO HAVING DOUBTS THE DEGREE OF CLEARING ANY LOCATION
WILL SEE. TIME-LAGGED RUC SOUNDINGS FROM THE LAST 6 OPERATIONAL
13KM RUNS DEFINITELY TRENDING ON HOLDING LOW LEVEL MOISTURE IN
LONGER. 31.12Z RUC 950-900MB LAYER HUMIDITIES DO IMPROVE FOR SOME
CLEARING AFTER 20Z...MOST LIKELY A MANIFESTATION OF MUCH DRIER AIR
ABOVE THIS LAYER ADVECTING IN ON WLY FLOW FROM ILLINOIS /WHERE
CLEARING TAKING PLACE/...WITH MIXING/EROSION LIKELY CHEWING SOME HOLES
IN THE THICK LOW LEVEL STRATUS INTO MID/LATE AFTERNOON. EVEN WITH
THAT...FELT PRUDENT BASED ON CURRENT TEMPS AND BLEND OF HI-RES
SHORT TERM GUIDANCE /HRRR...WRF...LAMP...RUC/ TO DROP AFTERNOON
HIGH TEMPERATURES BY A GOOD 3 TO 5 DEGREES. SHOULD SEE THE VSBYS
SLOWLY IMPROVE THROUGH THE REST OF THE MORNING...AND THIS IS
ALREADY TRENDING IN 31.12Z - 31.14Z OBS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
UPPER LEVEL RIDGE BUILDING ACRS THE NATIONS MID SECTION WITH NWRLY
FLOW DOMINATING AND SURFACE RIDGE BUILDING INTO THE OHIO VALLEY BY
SUNDAY MORNING. ANY LINGERING CLOUDS WILL GIVE WAY TO CLEARING EARLY
TONIGHT WITH SOME INCREASE IN HIGH LEVEL CLOUDS LATE. EXPECT LOWS
FROM NEAR 40 NE TO THE MID 40S SOUTH.
EMBEDDED S/W IN THE NWRLY FLOW TO DROP SE THRU THE EASTERN GREAT
LAKES SUNDAY/SUNDAY NIGHT. ASSOCIATED BACK DOOR COLD FRONT TO DROP
SOUTH INTO OHIO SUNDAY AFTN. WL CONTINUE CURRENT TREND ALLOWING FOR
CHC POPS NORTH AND ONLY MENTIONING A SLIGHT CHC ACRS THE FAR S
LATE. THE INFLUENCE OF WAA AND SOME SUNSHINE AHD OF THIS FRONT
WILL ALLOW TEMPS TO WARM TO READINGS ABOUT 15 DEGREES ABOVE
NORMAL.
NUMERICAL MODEL SOLNS DIFFER ON WHERE THE BACK DOOR FRONT STALLS
OUT. EXPECT THIS FRONTAL BOUNDARY TO PUSH SW AND LOSE ITS IDENTITY
AS THE UPPER LEVEL RIDGE BUILDS INTO THE MS VLY. WL ONLY CONT
SLIGHT CHC POPS INTO SUNDAY EVENING AND THEN ALLOW FOR A DRY
OVERNIGHT. THE REMNANTS OF THE FRONTAL BOUNDARY STALLING OUT AND
BEGINNING TO PUSH BACK NE ON MONDAY. WITH A LACK OF UPPER SUPPORT
AND BEST INSTBY REMAINING TO OUR WEST. WL LIMIT POPS TO SLIGHT CHC
OF THUNDERSTORMS MONDAY AFTN ACRS THE SW. EXPECT MONDAYS HIGH TEMPS
TO BE 10 TO 15 DEGREES ABOVE NORMAL...RANGING FROM THE LOWER 70S
NE TO THE UPPER 70S SW.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MID LEVEL RIDGING WILL BE IN PLACE ACROSS THE OHIO VALLEY BY 12Z
MONDAY MORNING WITH A WEAKENING COLD FRONT TO OUR SOUTH. THE MODELS
ARE TRYING TO SHOW THIS FRONT LIFTING BACK TO THE NORTHEAST AS A
WARM FRONT THROUGH THE DAY ON MONDAY...BUT DISAGREE ON BOTH THE
TIMING AND THE STRENGTH OF THIS FEATURE. WILL THEREFORE JUST HANG ON
TO SOME LOWER CHANCE POPS MONDAY INTO MONDAY NIGHT.
THE MODELS ARE ALSO HAVING A DIFFICULT TIME RESOLVING THE SHORT
WAVE ENERGY MOVING OUT OF THE ROCKIES THROUGH MID WEEK. BOTH THE 12Z
NAM AND 12Z CMC ARE TRYING TO CLOSE OFF A 5H LOW AS IT MOVES INTO
THE TENNESSEE VALLEY WEDNESDAY INTO THURSDAY. HOWEVER...THE 00Z
ECMWF KEEPS THE CLOSED LOW WELL BACK TO THE SOUTHWEST AND AS A
RESULT IS MUCH SLOWER TO BRING RIDGING IN FROM THE WEST THROUGH
LATE IN THE WEEK. IN FACT...THE 00Z ECMWF KEEPS A FAIRLY DEEP TROUGH
OVER THE NORTHEASTERN UNITED STATES THROUGH THE LONG TERM PERIOD. IT
LOOKS LIKE THERE WILL BE A DECENT CHANCE OF SHOWERS AND
THUNDERSTORMS BY TUESDAY AS THE INITIAL ENERGY APPROACHES BUT THE
QUESTION WILL BE HOW LONG ANY TREAT WILL HANG AROUND INTO THE MIDDLE
PART OF THE WEEK. WITH THE CLOSED LOW OF THE GFS/CMC WOULD THINK ANY
LINGERING PCPN WOULD MAINLY REMAIN TO OUR SOUTHWEST. MEANWHILE...ANY
PCPN PUSHING DOWN THE BACK SIDE OF THE TROUGH OF THE ECMWF SHOULD
MAINLY REMAIN TO OUR EAST. WILL THEREFORE GO WITH A DRY FORECAST
FROM MID WEEK ON...BUT CONFIDENCE IS NOT VERY HIGH WITH THIS
FORECAST. OF COURSE TEMPERATURES THROUGH THE WEEK WILL ALSO BE
AFFECTED BY ALL OF THIS. WILL GENERALLY GO WITH A BLEND OF
PERSISTENCE AND THE MODELS BUT PERHAPS TREND A LITTLE MORE TOWARD
THE COOLER ECMWF...WHICH WOULD KEEP TEMPERATURES FAIRLY SEASONABLE
THROUGH THE WEEK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
CIGS/VSBYS ONLY VERY SLOWLY IMPROVING AT 14Z...AND WILL CONTINUE
TO DO SO. WILL NEED TO CONSIDER EXTENDING DURATION OF MVFR/IFR
CIGS AND VSBYS LATER IN THE AFTERNOON. CIGS SHOULD SCATTER OUT
LATE THIS AFTERNOON INTO THIS EVENING WITH THE POTENTIAL FOR MORE
FOG FORMATION. WILL ADDRESS THESE ISSUES IN UPCOMING 18Z TERMINALS.
OUTLOOK...SCATTERED THUNDERSTORMS POSSIBLE MONDAY INTO TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...AR
NEAR TERM...BINAU
SHORT TERM...AR
LONG TERM...JGL
AVIATION...CONIGLIO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1118 PM EDT SUN APR 1 2012
.SYNOPSIS...
LOW PRESSURE WILL DROP ACROSS THE AREA THIS EVENING PRODUCING
NUMEROUS SHOWERS INTO THE EVENING HOURS. A COOLER AND DRIER AIR
MASS WILL BE DIRECTED INTO THE AREA LATE TONIGHT INTO MONDAY...AS
HIGH PRESSURE BUILDS SOUTHEAST FROM HUDSON BAY. THE NEXT CHANCE OF
RAIN WILL COME BY LATE TUESDAY INTO EARLY WEDNESDAY...AS A WEAK
AREA OF LOW PRESSURE MOVES EASTWARD FROM THE OHIO VALLEY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CLIPPER LOW OVER SOUTHERN PA LATE THIS EVENING WILL CONTINUE TO
TRACK SE...PASSING OFF THE DELMARVA LATER TONIGHT. REGIONAL RADAR
MOSAIC SHOWING RAIN STILL FALLING ACROSS THE SOUTHERN THIRD OF PA
AT 03Z. HRRR AND RUC BOTH INDICATE THE LAST THE RAIN WILL EXIT
SOUTHERN PA BTWN 05Z-06Z.
CLEARING SKIES SHOULD DEVELOP LATE TONIGHT ACROSS CENTRAL AND
SOUTHERN PA...AS MUCH DRIER AIR MASS OVERSPREADS THE STATE. LOW
LVL MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION WILL LIKELY KEEP
STRATO-CU LOCKED IN OVR THE N MTNS...WHILE DOWNSLOPING NORTHERLY
FLOW YIELDS MCLEAR SKIES SOUTH OF I-80 BY DAWN. LIGHT WINDS WILL
BECOME GUSTY FROM THE NW OVR THE ENTIRE REGION TONIGHT...AS
CLIPPER LOW INTENSIFIES OFF THE E COAST. THESE GUSTY WINDS HAVE
ALREADY DEVELOPED ACROSS THE NW MTNS AS OF 03Z AND BUFKIT
SOUNDINGS SUPPORT GUSTS TO ARND 20KTS LATER TONIGHT ACROSS MUCH OF
SOUTHERN PA.
POST-FRONTAL AIR MASS WILL BE ONLY SEASONABLY COOL AND AN ACTIVE
NW WIND WILL KEEP ATMOS MIXED OVERNIGHT...SO LOW TEMPS SHOULD
ACTUALLY BE A BIT ABV SEASONAL NORMS...RANGING FROM THE L30S NW
MTNS...TO ARND 40F SOUTH.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
MONDAY WILL BE BREEZY...DRIER AND A LITTLE COOLER AS NORTHERLY
WINDS SPREAD IN BEHIND THE DEPARTING FRONT AND THE HIGH TO OUR
NORTH BEGINS NOSING DOWN. ANY EARLY CLOUDS WILL YIELD TO PLENTY OF
SUNSHINE BY MID TO LATE MORNING. GEFS 850 TEMPS SUPPORT HIGH
TEMPS IN THE 50S. DESPITE THE DRY AIR AND GUSTY WINDS OVR EASTERN
PA ON MONDAY...THINKING IS TODAY/S RAINFALL WILL DAMPEN FINE FUELS
ENOUGH TO PRECLUDE A SIGNIFICANT WILDFIRE THREAT.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BROAD UPPER TROFFING ALONG THE APPALACHIANS AT THE START OF THE
PERIOD...AN EXTENSION OF A LARGE UPPER VORTEX OVER ERN CANADA...IS
FORECAST TO WEAKEN AS THE MAIN SHORT WAVE TROF SWINGS
OFFSHORE...ALLOWING HEIGHTS TO RISE TEMPORARILY ACROSS PA AND INTO
NEW ENGLAND. TROFFING WILL RETURN MIDWEEK AS ENERGY IN THE
ACTIVE NRN STREAM JET DROPS DOWN THE EAST SIDE OF THE UPPER RIDGE
OVER THE CENTRAL U.S.
THIS CENTRAL U.S. UPPER RIDGE/OMEGA BLOCK PATTERN WILL MAKE ONLY
SLOW PROGRESS EAST AS IT IS BOMBARDED BY NUMEROUS NRN AND SRN
STREAM WAVES AS WELL AS BEING IMPEDED BY THE ERN CANADA UPPER LOW.
THIS WILL SERVE TO KEEP PA IN SOME DEGREE OF NW FLOW THROUGH THE
REMAINDER OF THE LONG TERM PD. WHILE THIS WILL HELP SUPPORT THE DRY
FORECAST...ANY WAVES IN THE FLOW COULD BECOME FLIES IN THE OINTMENT
SO TO SPEAK. THOUGH AT THIS POINT NO OPPORTUNITIES FOR SIGNIFICANT
RAINFALL APPEAR LIKELY. THE NW FLOW WILL ALSO BRING COOLER...OR
RATHER CLOSE TO NORMAL...OR EVER SO SLIGHTLY BELOW NORMAL TEMPS FOR
THUR AND FRI BEFORE A WARM UP FOR NEXT WEEKEND.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
STILL SOME SHOWERS ACROSS SOUTHERN PA...THEY WILL BE SOUTH OF
THE AREA IN A FEW MORE HOURS.
LOW CIGS WITH FOG STARTING TO WORK INTO THE AREA FROM THE
NORTH. LOW CIGS AND FOG LIKELY TO PERSIST UNTIL LATE MONDAY
MORNING.
OTHERWISE...MOST OF MONDAY INTO TUE WILL BE VFR...AS VERY DRY
AIR WORKS IN. MONDAY WILL BE ON THE WINDY SIDE.
SOME SHOWERS LATE TUE INTO WED. MOISTURE IS LIMITED...BUT
DYNAMICS TRENDING STRONGER NOW.
LATE WED INTO NEXT SUNDAY...EASTER SUNDAY...LOOK DRY WITH
MAINLY VFR CONDITIONS...AS HIGH PRESSURE BUILDS OVER THE AREA.
OUTLOOK...
TUE...VFR/MVFR WITH SHOWERS LATE.
WED...MVFR WITH A CHC OF SHOWERS EARLY...OTHERWISE VFR.
THU-FRI...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1050 PM EDT SUN APR 1 2012
.SYNOPSIS...
LOW PRESSURE WILL DROP ACROSS THE AREA THIS EVENING PRODUCING
NUMEROUS SHOWERS INTO THE EVENING HOURS. A COOLER AND DRIER AIR
MASS WILL BE DIRECTED INTO THE AREA LATE TONIGHT INTO MONDAY...AS
HIGH PRESSURE BUILDS SOUTHEAST FROM HUDSON BAY. THE NEXT CHANCE OF
RAIN WILL COME BY LATE TUESDAY INTO EARLY WEDNESDAY...AS A WEAK
AREA OF LOW PRESSURE MOVES EASTWARD FROM THE OHIO VALLEY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CLIPPER LOW OVER SOUTHERN PA LATE THIS EVENING WILL CONTINUE TO
TRACK SE...PASSING OFF THE DELMARVA LATER TONIGHT. REGIONAL RADAR
MOSAIC SHOWING RAIN STILL FALLING ACROSS THE SOUTHERN THIRD OF PA
AT 03Z. HRRR AND RUC BOTH INDICATE THE LAST THE RAIN WILL EXIT
SOUTHERN PA BTWN 05Z-06Z.
CLEARING SKIES SHOULD DEVELOP LATE TONIGHT ACROSS CENTRAL AND
SOUTHERN PA...AS MUCH DRIER AIR MASS OVERSPREADS THE STATE. LOW
LVL MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION WILL LIKELY KEEP
STRATO-CU LOCKED IN OVR THE N MTNS...WHILE DOWNSLOPING NORTHERLY
FLOW YIELDS MCLEAR SKIES SOUTH OF I-80 BY DAWN. LIGHT WINDS WILL
BECOME GUSTY FROM THE NW OVR THE ENTIRE REGION TONIGHT...AS
CLIPPER LOW INTENSIFIES OFF THE E COAST. THESE GUSTY WINDS HAVE
ALREADY DEVELOPED ACROSS THE NW MTNS AS OF 03Z AND BUFKIT
SOUNDINGS SUPPORT GUSTS TO ARND 20KTS LATER TONIGHT ACROSS MUCH OF
SOUTHERN PA.
POST-FRONTAL AIR MASS WILL BE ONLY SEASONABLY COOL AND AN ACTIVE
NW WIND WILL KEEP ATMOS MIXED OVERNIGHT...SO LOW TEMPS SHOULD
ACTUALLY BE A BIT ABV SEASONAL NORMS...RANGING FROM THE L30S NW
MTNS...TO ARND 40F SOUTH.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
MONDAY WILL BE BREEZY...DRIER AND A LITTLE COOLER AS NORTHERLY
WINDS SPREAD IN BEHIND THE DEPARTING FRONT AND THE HIGH TO OUR
NORTH BEGINS NOSING DOWN. ANY EARLY CLOUDS WILL YIELD TO PLENTY OF
SUNSHINE BY MID TO LATE MORNING. GEFS 850 TEMPS SUPPORT HIGH
TEMPS IN THE 50S. DESPITE THE DRY AIR AND GUSTY WINDS OVR EASTERN
PA ON MONDAY...THINKING IS TODAY/S RAINFALL WILL DAMPEN FINE FUELS
ENOUGH TO PRECLUDE A SIGNIFICANT WILDFIRE THREAT.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BROAD UPPER TROFFING ALONG THE APPALACHIANS AT THE START OF THE
PERIOD...AN EXTENSION OF A LARGE UPPER VORTEX OVER ERN CANADA...IS
FORECAST TO WEAKEN AS THE MAIN SHORT WAVE TROF SWINGS
OFFSHORE...ALLOWING HEIGHTS TO RISE TEMPORARILY ACROSS PA AND INTO
NEW ENGLAND. TROFFING WILL RETURN MIDWEEK AS ENERGY IN THE
ACTIVE NRN STREAM JET DROPS DOWN THE EAST SIDE OF THE UPPER RIDGE
OVER THE CENTRAL U.S.
THIS CENTRAL U.S. UPPER RIDGE/OMEGA BLOCK PATTERN WILL MAKE ONLY
SLOW PROGRESS EAST AS IT IS BOMBARDED BY NUMEROUS NRN AND SRN
STREAM WAVES AS WELL AS BEING IMPEDED BY THE ERN CANADA UPPER LOW.
THIS WILL SERVE TO KEEP PA IN SOME DEGREE OF NW FLOW THROUGH THE
REMAINDER OF THE LONG TERM PD. WHILE THIS WILL HELP SUPPORT THE DRY
FORECAST...ANY WAVES IN THE FLOW COULD BECOME FLIES IN THE OINTMENT
SO TO SPEAK. THOUGH AT THIS POINT NO OPPORTUNITIES FOR SIGNIFICANT
RAINFALL APPEAR LIKELY. THE NW FLOW WILL ALSO BRING COOLER...OR
RATHER CLOSE TO NORMAL...OR EVER SO SLIGHTLY BELOW NORMAL TEMPS FOR
THUR AND FRI BEFORE A WARM UP FOR NEXT WEEKEND.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
WIND SHIFT LINE OVER CENTRAL PA...WITH SOME SHOWERS ACROSS
THE SOUTHERN PART OF THE STATE. THUNDERSTORMS DROPPING SE
FROM OH INTO SW PA. TRANSVERSE CI BANDS OVER NORTHERN PA
AGAIN...GIVEN VERY STRONG DYNAMICS MOVING ACROSS THE AREA.
EXPECT MORE IN THE WAY OF MVFR AND IFR CONDITIONS LATER TONIGHT
AND EARLY MONDAY MORNING...AS SECONDARY PUSH OF DRY AIR DROPS
SOUTHWARD FROM SOUTHERN ONTARIO.
MOST OF MONDAY INTO TUE WILL BE VFR...AS VERY DRY AIR WORKS
IN. MONDAY WILL BE ON THE WINDY SIDE.
SOME SHOWERS LATE TUE INTO WED. MOISTURE IS LIMITED...BUT
DYNAMICS TRENDING STRONGER NOW.
LATE WED INTO NEXT SUNDAY...EASTER SUNDAY...LOOK DRY WITH
MAINLY VFR CONDITIONS...AS HIGH PRESSURE BUILDS OVER THE AREA.
OUTLOOK...
TUE...VFR/MVFR WITH SHOWERS LATE.
WED...MVFR WITH A CHC OF SHOWERS EARLY...OTHERWISE VFR.
THU-FRI...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
844 PM EDT SUN APR 1 2012
.SYNOPSIS...
LOW PRESSURE WILL DROP ACROSS THE AREA THIS EVENING PRODUCING
NUMEROUS SHOWERS INTO THE EVENING HOURS. A COOLER AND DRIER AIR
MASS WILL BE DIRECTED INTO THE AREA LATE TONIGHT INTO MONDAY...AS
HIGH PRESSURE BUILDS SOUTHEAST FROM HUDSON BAY. THE NEXT CHANCE OF
RAIN WILL COME BY LATE TUESDAY INTO EARLY WEDNESDAY...AS A WEAK
AREA OF LOW PRESSURE MOVES EASTWARD FROM THE OHIO VALLEY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CLIPPER LOW OVER SOUTHERN PA THIS EVENING WILL CONTINUE TO TRACK
SE...PASSING OFF THE DELMARVA LATER TONIGHT. REGIONAL RADAR MOSAIC
SHOWING NUMEROUS SHOWERS ACROSS THE SOUTHERN HALF OF PA AT 00Z.
HRRR AND RUC BOTH INDICATE THE LAST THE SHOWERS WILL EXIT SOUTHERN
PA BY ARND 05Z. BLENDED QPF OF GEFS AND 18Z OPER RUNS BTWN
00Z-05Z OF UP TO 2 TENTHS OF AN INCH ALONG THE S TIER.
CLEARING SKIES SHOULD DEVELOP LATE TONIGHT ACROSS CENTRAL AND
SOUTHERN PA...AS MUCH DRIER AIR MASS OVERSPREADS THE STATE. LOW
LVL MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION WILL LIKELY KEEP
STRATO-CU LOCKED IN OVR THE N MTNS...WHILE DOWNSLOPING NORTHERLY
FLOW YIELDS MCLEAR SKIES SOUTH OF I-80 BY DAWN. LIGHT WINDS WILL
BECOME GUSTY FROM THE NW OVR THE ENTIRE REGION TONIGHT...AS
CLIPPER LOW INTENSIFIES OFF THE E COAST. BUFKIT SOUNDINGS SUPPORT
GUSTS TO ARND 20KTS LATER TONIGHT ACROSS MUCH OF SOUTHERN PA.
POST-FRONTAL AIR MASS WILL BE ONLY SEASONABLY COOL AND AN ACTIVE
NW WIND WILL KEEP ATMOS MIXED OVERNIGHT...SO LOW TEMPS SHOULD
ACTUALLY BE A BIT ABV SEASONAL NORMS...RANGING FROM THE L30S NW
MTNS...TO ARND 40F SOUTH.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
MONDAY WILL BE BREEZY...DRIER AND A LITTLE COOLER AS NORTHERLY
WINDS SPREAD IN BEHIND THE DEPARTING FRONT AND THE HIGH TO OUR
NORTH BEGINS NOSING DOWN. ANY EARLY CLOUDS WILL YIELD TO PLENTY OF
SUNSHINE BY MID TO LATE MORNING. GEFS 850 TEMPS SUPPORT HIGH
TEMPS IN THE 50S. DESPITE THE DRY AIR AND GUSTY WINDS OVR EASTERN
PA ON MONDAY...THINKING IS TODAY/S RAINFALL WILL DAMPEN FINE FUELS
ENOUGH TO PRECLUDE A SIGNIFICANT WILDFIRE THREAT.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BROAD UPPER TROFFING ALONG THE APPALACHIANS AT THE START OF THE
PERIOD...AN EXTENSION OF A LARGE UPPER VORTEX OVER ERN CANADA...IS
FORECAST TO WEAKEN AS THE MAIN SHORT WAVE TROF SWINGS
OFFSHORE...ALLOWING HEIGHTS TO RISE TEMPORARILY ACROSS PA AND INTO
NEW ENGLAND. TROFFING WILL RETURN MIDWEEK AS ENERGY IN THE
ACTIVE NRN STREAM JET DROPS DOWN THE EAST SIDE OF THE UPPER RIDGE
OVER THE CENTRAL U.S.
THIS CENTRAL U.S. UPPER RIDGE/OMEGA BLOCK PATTERN WILL MAKE ONLY
SLOW PROGRESS EAST AS IT IS BOMBARDED BY NUMEROUS NRN AND SRN
STREAM WAVES AS WELL AS BEING IMPEDED BY THE ERN CANADA UPPER LOW.
THIS WILL SERVE TO KEEP PA IN SOME DEGREE OF NW FLOW THROUGH THE
REMAINDER OF THE LONG TERM PD. WHILE THIS WILL HELP SUPPORT THE DRY
FORECAST...ANY WAVES IN THE FLOW COULD BECOME FLIES IN THE OINTMENT
SO TO SPEAK. THOUGH AT THIS POINT NO OPPORTUNITIES FOR SIGNIFICANT
RAINFALL APPEAR LIKELY. THE NW FLOW WILL ALSO BRING COOLER...OR
RATHER CLOSE TO NORMAL...OR EVER SO SLIGHTLY BELOW NORMAL TEMPS FOR
THUR AND FRI BEFORE A WARM UP FOR NEXT WEEKEND.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
WIND SHIFT LINE OVER CENTRAL PA...WITH SOME SHOWERS ACROSS
THE SOUTHERN PART OF THE STATE. THUNDERSTORMS DROPPING SE
FROM OH INTO SW PA. TRANSVERSE CI BANDS OVER NORTHERN PA
AGAIN...GIVEN VERY STRONG DYNAMICS MOVING ACROSS THE AREA.
EXPECT MORE IN THE WAY OF MVFR AND IFR CONDITIONS LATER TONIGHT
AND EARLY MONDAY MORNING...AS SECONDARY PUSH OF DRY AIR DROPS
SOUTHWARD FROM SOUTHERN ONTARIO.
MOST OF MONDAY INTO TUE WILL BE VFR...AS VERY DRY AIR WORKS
IN. MONDAY WILL BE ON THE WINDY SIDE.
SOME SHOWERS LATE TUE INTO WED. MOISTURE IS LIMITED...BUT
DYNAMICS TRENDING STRONGER NOW.
LATE WED INTO NEXT SUNDAY...EASTER SUNDAY...LOOK DRY WITH
MAINLY VFR CONDITIONS...AS HIGH PRESSURE BUILDS OVER THE AREA.
OUTLOOK...
TUE...VFR/MVFR WITH SHOWERS LATE.
WED...MVFR WITH A CHC OF SHOWERS EARLY...OTHERWISE VFR.
THU-FRI...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...MARTIN
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1152 AM CDT SAT MAR 31 2012
.DISCUSSION.../ISSUED AT 1152 AM CDT/
EXTENDED COVERAGE OF FOG THROUGH THE NORTHEASTERN THIRD OF AREA
THROUGH MIDDAY...BUT EVENTUALLY SHOULD SEE ENOUGH HEATING TO ERODE
ALL LOWER CLOUDS...BUT NOT WITHOUT THE EXPENSE OF CUTTING BACK ON
HIGHS IN THE EXTREME EAST/NORTHEAST. WATCHING PROGRESSION OF WEAK
DRY LINE/BOUNDARY THROUGH THE WESTERN CWA THIS MORNING...WHICH WILL
SHARPEN UP JUST SOUTH OF THE MISSOURI VALLEY THIS EVENING. THERE IS
A WEAK WAVE ENHANCING SOME MID TO HIGH CLOUDS ACROSS WESTERN INTO
CENTRAL SD AS OF MID MORNING...AND WILL BE INTERESTING TO SEE IF
THERE IS ENOUGH LIFT FROM THIS FEATURE AS IT SLIDES EAST/SOUTHEAST
INTO NORTHWEST IOWA LATE THIS AFTERNOON...AND BREAK WHAT LOOKS TO BE
CAP REMAINING NEAR THE WARM FRONT THROUGH NORTHWEST IOWA BY MID TO
LATE AFTERNOON. AT THIS TIME...JUST ENOUGH CAPPING TO THINK ANYTHING
WILL HAPPEN...BUT IN THE EVENT THAT LOW LEVEL MOISTURE POOLS JUST A
BIT MORE THAN EXPECTED AND EFFECTIVELY WEAKENS CAP...WILL MAINTAIN A
SMALLER AREA OF SLIGHT CHANCE POPS IN FAR SOUTHEAST. NEVERTHELESS...
WEAK SHEAR WOULD KEEP ANY ROGUE STORMS IN NON SEVERE MODES.
LOOKING AT TONIGHT...MAY VERY WELL END UP WITH ANOTHER EPISODE OF
FOG/LOW CLOUDS DEVELOPING OVERNIGHT NORTH OF THIS FRONTAL BOUNDARY.
/CHAPMAN
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
SOUTHEAST WINDS ADVECTING IN MOISTURE...COMBINED WITH NIGHTTIME
COOLING...HAS ALLOWED FOG AND LOW STRATUS TO FORM ACROSS SOUTHWEST
MINNESOTA AND NORTHWEST IOWA...WITH LIFR CIGS OF A COUPLE HUNDRED
FEET AND VISIBILITIES AT OR BELOW 2 MILES. RUC AND HRRR BACK THIS TO
THE WEST A BIT MORE THIS MORNING. THUS THINK IT WILL MAKE IT AS FAR
WEST AS ROUGHLY ALONG A SIOUX FALLS TO BROOKINGS LINE. AS THE SUN
RISES AND LOW LEVEL MIXING COMMENCES...SHOULD INITIALLY SEE THIS
REINFORCE THE LOW CLOUD DECK. HOWEVER WITH CONTINUED HEATING WE WILL
SEE THE CLOUDS BEGIN TO DISSIPATE FROM WEST TO EAST BY MID MORNING.
CURRENT THINKING HAS KFSD VFR BY AROUND 11AM. KSUX IS ALSO RIGHT ON
THE EDGE OF THE STRATUS DECK...BUT THINK THEY SHOULD REMAIN JUST TO
ITS SOUTHWEST...ALTHOUGH CAN NOT RULE OUT THEM BRIEFLY DROPPING TO
MVFR THIS MORNING.
ONCE THE LOW CLOUDS ERODE...VFR FLYING CONDITIONS SHOULD PERSIST
INTO TOMORROW MORNING. SOUTH SOUTHEAST WINDS WILL BRIEFLY TURN
NORTHERLY NORTH OF INTERSTATE 90 THIS AFTERNOON...BEFORE SWITCHING
BACK TO THE SOUTHEAST TONIGHT. WINDS ARE EXPECTED TO MAINLY REMAIN
BELOW 12 KTS THROUGH THE PERIOD. /CHENARD
&&
.PREV DISCUSSION.../ISSUED AT 700 AM CDT/
UPDATED TO ADD MORE FOG TO AREAS EAST OF I29 THROUGH MID MORNING.
FOG WILL BE DENSE IN PLACES. THIS SHOULD BURN OFF BY MID TO LATE
MORNING.
STRATUS HAS REFORMED ACROSS PORTIONS OF SOUTHWEST MINNESOTA AND
NORTHWEST IOWA WITH LOW LEVEL SOUTHEAST FLOW. REST OF CWA HAS PLENTY
OF HIGH CLOUDS STREAMING ACROSS THE REGION. SO WILL START OUT CLOUDY
TO MOSTLY CLOUDY WITH AREAS EAST OF I29 SLOWEST TO BREAK OUT DURING
THE MID TO LATE MORNING. THIS WILL SLOW DOWN WARMUP ACROSS EAST THIS
MORNING...BUT STILL SHOULD WARM INTO 70S EAST OF I29 AND 80 TO 85 TO
THE WEST.
WEAK SHORT WAVE IS PROGGED BY MODELS TO RIDE OVER TOP OF RIDGE THIS
AFTERNOON WITH WEAK QUASI WARM FRONT DEVELOPING OVER NORTHWEST IOWA.
SOME INSTABILITY DURING THE AFTERNOON ON EDGE OF MID CAP AND COULD
SEE AN ISOLATED THUNDERSTORMS ACROSS THE FAR SOUTHEAST AND HAVE
ADDED 20% THERE AFTER 20Z.
SHOULD CLEAR OUT ACROSS CWA TONIGHT WITH EVEN WARMER TEMPERATURES ON
SUNDAY AS H85 FLOW BECOME MORE SOUTHWEST ALLOWING FOR A LITTLE
BETTER MIXING. SO SHOULD SEE HIGHS IN THE 80S AND NEAR 90 ALONG THE
MISSOURI RIVER. SHOULD BE PLENTY OF RECORDS BEING SET THIS WEEKEND.
COLD FRONT WILL PUSH INTO WESTERN CWA LATE SUNDAY AFTERNOON...BUT
STRONG CAPPING WILL PROBABLY PREVENT ANY THUNDERSTORMS DEVELOPMENT
AHEAD OF FRONT.
WILL KEEP SMALL CHANCE OF THUNDERSTORMS SUNDAY NIGHT WEST OF I29
CORRIDOR JUST BEHIND FRONT WHERE COOLER MID LEVEL TEMPERATURES MAY
BE ENOUGH TO WEAKEN CAP.
INITIAL COOLING BEHIND THE FRONT WILL BE LAGGING AND WILL NOT REALLY
MAKE ITS PUSH UNTIL SUNDAY NIGHT...WITH WINDY AND COOLER CONDITIONS
ON MONDAY. WILL KEEP A LINGERING CHANCE OF THUNDERSTORMS ALONG AND
EAST OF INTERSTATE 29 ON MONDAY BEHIND THE FRONT...BUT DYNAMICS NOT
ALL THAT IMPRESSIVE TO GO MORE THAN 20 TO 30%.
WILL BE COOLER NEXT WEEK AS MORE OF AN EAST TO SOUTHEAST LOW LEVEL
FLOW OFF OF GREAT LAKES HIGH DEVELOPS. STILL ABOVE NORMAL
TEMPERATURES BUT HIGHS MAINLY IN THE UPPER 50S TO MID 60S TUESDAY
AND WEDNESDAY AND SLIGHTLY WARMER THURSDAY AND FRIDAY. WILL NEED TO
WATCH UPPER LOW OVER SOUTHWEST US AS IT MEANDERS ACROSS THE SOUTHERN
PLAINS MID WEEK. COULD SEE A FEW SHOWERS ACROSS FAR SOUTHEAST
WEDNESDAY OR THURSDAY...BUT FOR NOW WILL LEAVE DRY AS FLOW ALOFT
SHOULD KEEP STORM TO THE SOUTH.
LOOKS LIKE IT COULD BE MORE STORMY NEXT WEEKEND AS FAIRLY DECENT
WAVE MOVES EAST ACROSS THE NORTHERN PLAINS. MODELS NOT AGREEING ALL
THAT WELL WITH TIMING OF THIS FEATURE.
FIRE DANGER LIKELY TO BE VERY HIGH OR EXTREME WESTERN CWA TODAY AND
SUNDAY...BUT WINDS NOT STRONG ENOUGH TO WARRANT FIRE WEATHER WATCH.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
700 AM CDT SAT MAR 31 2012
.DISCUSSION.../ISSUED AT 700 AM CDT/
UPDATED TO ADD MORE FOG TO AREAS EAST OF I29 THROUGH MID MORNING.
FOG WILL BE DENSE IN PLACES. THIS SHOULD BURN OFF BY MID TO LATE
MORNING.
STRATUS HAS REFORMED ACROSS PORTIONS OF SOUTHWEST MINNESOTA AND
NORTHWEST IOWA WITH LOW LEVEL SOUTHEAST FLOW. REST OF CWA HAS PLENTY
OF HIGH CLOUDS STREAMING ACROSS THE REGION. SO WILL START OUT CLOUDY
TO MOSTLY CLOUDY WITH AREAS EAST OF I29 SLOWEST TO BREAK OUT DURING
THE MID TO LATE MORNING. THIS WILL SLOW DOWN WARMUP ACROSS EAST THIS
MORNING...BUT STILL SHOULD WARM INTO 70S EAST OF I29 AND 80 TO 85 TO
THE WEST.
WEAK SHORT WAVE IS PROGGED BY MODELS TO RIDE OVER TOP OF RIDGE THIS
AFTERNOON WITH WEAK QUASI WARM FRONT DEVELOPING OVER NORTHWEST IOWA.
SOME INSTABILITY DURING THE AFTERNOON ON EDGE OF MID CAP AND COULD
SEE AN ISOLATED THUNDERSTORMS ACROSS THE FAR SOUTHEAST AND HAVE
ADDED 20% THERE AFTER 20Z.
SHOULD CLEAR OUT ACROSS CWA TONIGHT WITH EVEN WARMER TEMPERATURES ON
SUNDAY AS H85 FLOW BECOME MORE SOUTHWEST ALLOWING FOR A LITTLE
BETTER MIXING. SO SHOULD SEE HIGHS IN THE 80S AND NEAR 90 ALONG THE
MISSOURI RIVER. SHOULD BE PLENTY OF RECORDS BEING SET THIS WEEKEND.
COLD FRONT WILL PUSH INTO WESTERN CWA LATE SUNDAY AFTERNOON...BUT
STRONG CAPPING WILL PROBABLY PREVENT ANY THUNDERSTORMS DEVELOPMENT
AHEAD OF FRONT.
WILL KEEP SMALL CHANCE OF THUNDERSTORMS SUNDAY NIGHT WEST OF I29
CORRIDOR JUST BEHIND FRONT WHERE COOLER MID LEVEL TEMPERATURES MAY
BE ENOUGH TO WEAKEN CAP.
INITIAL COOLING BEHIND THE FRONT WILL BE LAGGING AND WILL NOT REALLY
MAKE ITS PUSH UNTIL SUNDAY NIGHT...WITH WINDY AND COOLER CONDITIONS
ON MONDAY. WILL KEEP A LINGERING CHANCE OF THUNDERSTORMS ALONG AND
EAST OF INTERSTATE 29 ON MONDAY BEHIND THE FRONT...BUT DYNAMICS NOT
ALL THAT IMPRESSIVE TO GO MORE THAN 20 TO 30%.
WILL BE COOLER NEXT WEEK AS MORE OF AN EAST TO SOUTHEAST LOW LEVEL
FLOW OFF OF GREAT LAKES HIGH DEVELOPS. STILL ABOVE NORMAL
TEMPERATURES BUT HIGHS MAINLY IN THE UPPER 50S TO MID 60S TUESDAY
AND WEDNESDAY AND SLIGHTLY WARMER THURSDAY AND FRIDAY. WILL NEED TO
WATCH UPPER LOW OVER SOUTHWEST US AS IT MEANDERS ACROSS THE SOUTHERN
PLAINS MID WEEK. COULD SEE A FEW SHOWERS ACROSS FAR SOUTHEAST
WEDNESDAY OR THURSDAY...BUT FOR NOW WILL LEAVE DRY AS FLOW ALOFT
SHOULD KEEP STORM TO THE SOUTH.
LOOKS LIKE IT COULD BE MORE STORMY NEXT WEEKEND AS FAIRLY DECENT
WAVE MOVES EAST ACROSS THE NORTHERN PLAINS. MODELS NOT AGREEING ALL
THAT WELL WITH TIMING OF THIS FEATURE.
FIRE DANGER LIKELY TO BE VERY HIGH OR EXTREME WESTERN CWA TODAY AND
SUNDAY...BUT WINDS NOT STRONG ENOUGH TO WARRANT FIRE WEATHER WATCH.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
SOUTHEAST WINDS ADVECTING IN MOISTURE...COMBINED WITH NIGHTTIME
COOLING...HAS ALLOWED FOG AND LOW STRATUS TO FORM ACROSS SOUTHWEST
MINNESOTA AND NORTHWEST IOWA...WITH LIFR CIGS OF A COUPLE HUNDRED
FEET AND VISIBILITIES AT OR BELOW 2 MILES. RUC AND HRRR BACK THIS TO
THE WEST A BIT MORE THIS MORNING. THUS THINK IT WILL MAKE IT AS FAR
WEST AS ROUGHLY ALONG A SIOUX FALLS TO BROOKINGS LINE. AS THE SUN
RISES AND LOW LEVEL MIXING COMMENCES...SHOULD INITIALLY SEE THIS
REINFORCE THE LOW CLOUD DECK. HOWEVER WITH CONTINUED HEATING WE WILL
SEE THE CLOUDS BEGIN TO DISSIPATE FROM WEST TO EAST BY MID MORNING.
CURRENT THINKING HAS KFSD VFR BY AROUND 11AM. KSUX IS ALSO RIGHT ON
THE EDGE OF THE STRATUS DECK...BUT THINK THEY SHOULD REMAIN JUST TO
ITS SOUTHWEST...ALTHOUGH CAN NOT RULE OUT THEM BRIEFLY DROPPING TO
MVFR THIS MORNING.
ONCE THE LOW CLOUDS ERODE...VFR FLYING CONDITIONS SHOULD PERSIST
INTO TOMORROW MORNING. SOUTH SOUTHEAST WINDS WILL BRIEFLY TURN
NORTHERLY NORTH OF INTERSTATE 90 THIS AFTERNOON...BEFORE SWITCHING
BACK TO THE SOUTHEAST TONIGHT. WINDS ARE EXPECTED TO MAINLY REMAIN
BELOW 12 KTS THROUGH THE PERIOD. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
650 AM CDT SAT MAR 31 2012
.DISCUSSION.../ISSUED AT 255 AM CDT/
STRATUS HAS REFORMED ACROSS PORTIONS OF SOUTHWEST MINNESOTA AND
NORTHWEST IOWA WITH LOW LEVEL SOUTHEAST FLOW. REST OF CWA HAS PLENTY
OF HIGH CLOUDS STREAMING ACROSS THE REGION. SO WILL START OUT CLOUDY
TO MOSTLY CLOUDY WITH AREAS EAST OF I29 SLOWEST TO BREAK OUT DURING
THE MID TO LATE MORNING. THIS WILL SLOW DOWN WARMUP ACROSS EAST THIS
MORNING...BUT STILL SHOULD WARM INTO 70S EAST OF I29 AND 80 TO 85 TO
THE WEST.
WEAK SHORT WAVE IS PROGGED MY MODELS TO RIDE OVER TOP OF RIDGE THIS
AFTERNOON WITH WEAK QUASI WARM FRONT DEVELOPING OVER NORTHWEST IOWA.
SOME INSTABILITY DURING THE AFTERNOON ON EDGE OF MID CAP AND COULD
SEE AN ISOLATED THUNDERSTORMS ACROSS THE FAR SOUTHEAST AND HAVE
ADDED 20% THERE AFTER 20Z.
SHOULD CLEAR OUT ACROSS CWA TONIGHT WITH EVEN WARMER TEMPERATURES ON
SUNDAY AS H85 FLOW BECOME MORE SOUTHWEST ALLOWING FOR A LITTLE
BETTER MIXING. SO SHOULD SEE HIGHS IN THE 80S AND NEAR 90 ALONG THE
MISSOURI RIVER. SHOULD BE PLENTY OF RECORDS BEING SET THIS WEEKEND.
COLD FRONT WILL PUSH INTO WESTERN CWA LATE SUNDAY AFTERNOON...BUT
STRONG CAPPING WILL PROBABLY PREVENT ANY THUNDERSTORMS DEVELOPMENT
AHEAD OF FRONT.
WILL KEEP SMALL CHANCE OF THUNDERSTORMS SUNDAY NIGHT WEST OF I29
CORRIDOR JUST BEHIND FRONT WHERE COOLER MID LEVEL TEMPERATURES MAY
BE ENOUGH TO WEAKEN CAP.
INITIAL COOLING BEHIND THE FRONT WILL BE LAGGING AND WILL NOT REALLY
MAKE ITS PUSH UNTIL SUNDAY NIGHT...WITH WINDY AND COOLER CONDITIONS
ON MONDAY. WILL KEEP A LINGERING CHANCE OF THUNDERSTORMS ALONG AND
EAST OF INTERSTATE 29 ON MONDAY BEHIND THE FRONT...BUT DYNAMICS NOT
ALL THAT IMPRESSIVE TO GO MORE THAN 20 TO 30%.
WILL BE COOLER NEXT WEEK AS MORE OF AN EAST TO SOUTHEAST LOW LEVEL
FLOW OFF OF GREAT LAKES HIGH DEVELOPS. STILL ABOVE NORMAL
TEMPERATURES BUT HIGHS MAINLY IN THE UPPER 50S TO MID 60S TUESDAY
AND WEDNESDAY AND SLIGHTLY WARMER THURSDAY AND FRIDAY. WILL NEED TO
WATCH UPPER LOW OVER SOUTHWEST US AS IT MEANDERS ACROSS THE SOUTHERN
PLAINS MID WEEK. COULD SEE A FEW SHOWERS ACROSS FAR SOUTHEAST
WEDNESDAY OR THURSDAY...BUT FOR NOW WILL LEAVE DRY AS FLOW ALOFT
SHOULD KEEP STORM TO THE SOUTH.
LOOKS LIKE IT COULD BE MORE STORMY NEXT WEEKEND AS FAIRLY DECENT
WAVE MOVES EAST ACROSS THE NORTHERN PLAINS. MODELS NOT AGREEING ALL
THAT WELL WITH TIMING OF THIS FEATURE.
FIRE DANGER LIKELY TO BE VERY HIGH OR EXTREME WESTERN CWA TODAY AND
SUNDAY...BUT WINDS NOT STRONG ENOUGH TO WARRANT FIRE WEATHER WATCH.
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
SOUTHEAST WINDS ADVECTING IN MOISTURE...COMBINED WITH NIGHTTIME
COOLING...HAS ALLOWED FOG AND LOW STRATUS TO FORM ACROSS SOUTHWEST
MINNESOTA AND NORTHWEST IOWA...WITH LIFR CIGS OF A COUPLE HUNDRED
FEET AND VISIBILITIES AT OR BELOW 2 MILES. RUC AND HRRR BACK THIS TO
THE WEST A BIT MORE THIS MORNING. THUS THINK IT WILL MAKE IT AS FAR
WEST AS ROUGHLY ALONG A SIOUX FALLS TO BROOKINGS LINE. AS THE SUN
RISES AND LOW LEVEL MIXING COMMENCES...SHOULD INITIALLY SEE THIS
REINFORCE THE LOW CLOUD DECK. HOWEVER WITH CONTINUED HEATING WE WILL
SEE THE CLOUDS BEGIN TO DISSIPATE FROM WEST TO EAST BY MID MORNING.
CURRENT THINKING HAS KFSD VFR BY AROUND 11AM. KSUX IS ALSO RIGHT ON
THE EDGE OF THE STRATUS DECK...BUT THINK THEY SHOULD REMAIN JUST TO
ITS SOUTHWEST...ALTHOUGH CAN NOT RULE OUT THEM BRIEFLY DROPPING TO
MVFR THIS MORNING.
ONCE THE LOW CLOUDS ERODE...VFR FLYING CONDITIONS SHOULD PERSIST
INTO TOMORROW MORNING. SOUTH SOUTHEAST WINDS WILL BRIEFLY TURN
NORTHERLY NORTH OF INTERSTATE 90 THIS AFTERNOON...BEFORE SWITCHING
BACK TO THE SOUTHEAST TONIGHT. WINDS ARE EXPECTED TO MAINLY REMAIN
BELOW 12 KTS THROUGH THE PERIOD. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
906 PM CDT SUN APR 1 2012
.UPDATE...
RAISED POPS THROUGH 06Z OUT WEST.
&&
.DISCUSSION...
STORMS WHICH ORIGINATED EARLIER THIS AFTERNOON ACROSS THE
SERRANIAS DEL BURRO HAVE MADE GOOD EASTWARD PROGRESSION OVER THE
LAST FEW HOURS INTO THE RIO GRANDE PLAINS. THE STRONGEST
THUNDERSTORMS IN THIS COMPLEX HAVE PRODUCED SMALL HAIL (PEA TO
NEAR HALF-INCH)...AND COULD SEE ANOTHER FEW ROUNDS OF HAIL
(POSSIBLY REACHING SEVERE LEVELS) THIS EVENING AS THE STORMS PULSE.
LATEST RUC ANALYSIS SUGGEST THAT THESE STORMS WILL CONTINUE TO
PUSH EASTWARD THROUGH THE NEXT FEW HOURS BEFORE DISSIPATING.
HOWEVER...MODELS TYPICALLY HAVE A HARD TIME WITH MESOSCALE
CONVECTIVE SYSTEMS COMING OFF OF THE MEXICAN MOUNTAINS AS FAR AS
INTENSITY AND LONGEVITY...SO ADDITIONAL UPDATES MAY BE NEEDED.
&&
.PREV DISCUSSION... /ISSUED 704 PM CDT SUN APR 1 2012/
DISCUSSION...
SEE UPDATED AVIATION DISCUSSION FOR 00Z TAFS.
AVIATION...
THE PRESSURE GRADIENT WILL BE INCREASING TONIGHT THROUGH MONDAY
ACROSS SOUTH CENTRAL TEXAS...AS SFC LOW PRESSURE CONTINUES TO
INCREASE OVER WEST TEXAS. THIS WILL SET UP A STRONGER LOW LEVEL
JET TONIGHT...AND CAUSE INCREASING LOW CLOUDINESS TONIGHT.
FOR THIS EVENING 5 THSD TO 10 THSD SCT IS EXPECTED...WITH SCT
CLOUDS INCREASING AT OR ABOVE 25 THSD FT. ISOLATED SHRA AND TSRA
ARE POSSIBLE VCNTY OF KDRT THRU 04Z. LATER TONIGHT...CIGS WILL
FORM AROUND 1 THSD TO 2 THSD FT FROM KAUS TO KSAT AROUND OR AFTER
04Z AND VCNTY OF KDRT AROUND OR AFTER 09Z TONIGHT. CIGS OF 500 TO
900 FT OVC ARE POSSIBLE VCNTY OF KAUS TO KSAT FROM 07Z TO 16Z
MONDAY. CIGS WILL BECOME 1 THSD TO 2 THSD BKN TO OVC AFTER 16Z
MONDAY...AND THEN INCREASE TO CIGS 3 THSD TO 5 THSD BKN AFTER 19Z
MONDAY AFTERNOON. SOUTH AND SOUTHEAST WINDS NEAR 10 KNOTS WILL
PICKUP TO 15 TO 20 KNOTS MONDAY...IN ADVANCE OF A STORM
SYSTEM...THAT WILL BRING INCREASING CHANCES OF SHOWERS OR
THUNDERSTORMS TO THE SOUTH CENTRAL TEXAS TAF SITES ON MONDAY NIGHT
THROUGH TUESDAY. THIS STORM SYSTEM IS FORECAST TO MOVE TO THE
TEXAS PANHANDLE AND WESTERN OK TUESDAY...AND THEN MOVE EAST LATE
TUESDAY THROUGH WEDNESDAY. AS THE LOW TRACKS EAST...NORTH OF SOUTH
CENTRAL TEXAS TUESDAY NIGHT AND WEDNESDAY...SCATTERED WRAP AROUND
CLOUDS COULD IMPACT THE SOUTH CENTRAL TEXAS TAF SITES...AS MORE
PREVAILING WEST TO NORTHWEST SFC WINDS DEVELOP...IN A PATTERN
SIMILAR TO THE WEATHER IN MARCH.
PREV DISCUSSION... /ISSUED 622 PM CDT SUN APR 1 2012/
DISCUSSION...
SEE AVIATION FOR 00Z TAFS.
AVIATION...
THE PRESSURE GRADIENT WILL BE INCREASING TONIGHT THROUGH MONDAY
ACROSS SOUTH CENTRAL TEXAS...AS THE SFC LOW PRESSURE CONTINUES
TO INCREASE OVER WEST TEXAS. THIS WILL SET UP A STRONGER
LOW LEVEL JET TONIGHT...AND CAUSE INCREASING LOW CLOUDINESS.
CIGS WILL FORM AROUND 1 THSD TO 2 THSD FT FROM KAUS TO KSAT
AROUND OR AFTER 04Z AND VCNTY OF KDRT AROUND OR AFTER 09Z
TONIGHT. CIGS OF 500 TO 900 FT OVC ARE POSSIBLE VCNTY OF KAUS TO
KSAT FROM 07Z TO 16Z MONDAY. CIGS WILL BECOME 1 THSD TO 2 THSD
BKN TO OVC AFTER 16Z MONDAY...AND THEN INCREASE TO CIGS 3 THSD
TO 5 THSD BKN AFTER 19Z MONDAY AFTERNOON. SOUTH AND SOUTHEAST
WINDS NEAR 10 KNOTS WILL PICKUP TO 15 TO 20 KNOTS MONDAY...IN
ADVANCE OF A STORM SYSTEM...THAT WILL BRING INCREASING CHANCES OF
SHOWERS OR THUNDERSTORMS TO THE SOUTH CENTRAL TEXAS TAF SITES ON
MONDAY NIGHT THROUGH TUESDAY. THIS STORM SYSTEM IS FORECAST TO
MOVE TO THE TEXAS PANHANDLE AND WESTERN OK TUESDAY...AND THEN
MOVE EAST LATE TUESDAY THROUGH WEDNESDAY. AS THE LOW TRACKS EAST...
NORTH OF SOUTH CENTRAL TEXAS TUESDAY NIGHT AND WEDNESDAY...
SCATTERED WRAP AROUND CLOUDS COULD IMPACT THE SOUTH CENTRAL TEXAS
TAF SITES...AS MORE PREVAILING WEST TO NORTHWEST SFC WINDS
DEVELOP...IN A PATTERN SIMILAR TO THE WEATHER IN MARCH.
PREV DISCUSSION... /ISSUED 339 PM CDT SUN APR 1 2012/
DISCUSSION...
WEAK PAIR OF SHORTWAVES WILL MAKE FOR A SLIGHT CHANCE OF
THUNDERSTORMS TONIGHT INTO MONDAY...BUT LIMITED SURFACE FOCUS WILL
MAKE IT DIFFICULT TO HIGHLIGHT AREAS OF CONVECTION INITIATION. ONE
LIKELY AREA OVER THE BURRO MOUNTAINS HAS ALREADY YIELDED
CONVECTION...BUT MODEL FORECAST WINDS SHOW STORM MOTIONS THAT WILL
TAKE A LONG TIME TO REACH THE RIO GRANDE. ISOLATED POPS ARE POSTED
ALONG THE RIO GRANDE WITH A FEW SHOWERS FORMING BENEATH THE CAP
POSSIBLE OVER EASTERN COUNTIES LATE TONIGHT. DEEPENING LOW LEVEL
MOISTURE SHOULD PROMOTE HIGHER RAIN AND THUNDERSTORM POTENTIAL
DURING THE DAY MONDAY AS A LARGE UPPER LOW DRAWS CLOSER.
THE APPROACHING LOW PRESSURE FROM THE WEST WILL BRING A SEVERE
WEATHER POTENTIAL...BUT SOME UNCERTAINTIES ON TIMING AND LOCATION
DUE TO MODELS SHOWING A SLOWING AND WOBBLING TREND. RECENT MODEL
TRENDS SHOW A SLIGHTLY MORE NORTHWARD TRACK WHEN THE LOW FINALLY
CROSSES TX LATE TUESDAY INTO WEDNESDAY. THIS GIVES SOUTH CENTRAL
TEXAS BOTH THE POTENTIAL FOR A SEVERE WEATHER EVENT MONDAY NIGHT
INTO TUESDAY AND ALSO A POTENTIAL TO BE DRY-SLOTTED...OF WHICH
EITHER SCENARIO COULD BE ENHANCED BY A SUBTLE WOBBLE. WILL STICK
WITH GENERIC SEVERE THREATS FOR NOW WITH BEST CHANCE OVER THE NW
HALF LATE MONDAY NIGHT/EARLY TUESDAY MORNING. IF THE DRY SLOT DOES
NOT SCRAPE AWAY TOO MUCH MOISTURE...A SEVERE AND POTENTIAL HEAVY
RAIN EVENT COULD DEVELOP DURING THE DAY TUESDAY BEFORE THE PACIFIC
FRONT PUSHES THROUGH THE I-35 CORRIDOR LATE IN THE DAY.
BASED ON A SPLIT OF MODEL SOLUTIONS WILL ADD A BIT MORE COLD AND
DRY AIR THAN IS SUGGESTED BY THE GFS SOLUTION WHICH MINIMIZES THE
COLD FRONT AND RETURNS MOISTURE QUICKLY BY THURSDAY. WILL PUSH THE
MOISTURE RETURN BACK TO FRIDAY TO ENABLE MORE SEASONAL TEMPS
THURSDAY AND FRIDAY. WILL ALSO LIMIT POPS FOR THE NEXT WEATHER
SYSTEM TO IMPACT THE AREA SATURDAY AND NEXT SUNDAY DUE TO THE MORE
GRADUAL MOISTURE RETURN AND THE PRESENCE OF AN UPPER RIDGE OVER
TX.
FIRE WEATHER...
A GOOD CHANCE OF WETTING RAINS COMBINED WITH NEAR OF ABOVE NORMAL
RAINFALL OVER WESTERN COUNTIES THE PAST 30 DAYS SHOULD LIMIT FIRE
SPREAD POTENTIAL...AS MOST AREAS HAVE NOTED A GOOD GREEN-UP OVER
SOUTH CENTRAL TEXAS. THUS WILL ANTICIPATE ONLY AN ELEVATED FIRE
WEATHER DAY DESPITE STRONG WEST WINDS AND CRITICAL RH VALUES NEAR
THE RIO GRANDE ON TUESDAY. WILL NEED TO LOOK AT THIS AREA IN MORE
DETAIL IN LATER PACKAGES IF FUTURE MODEL RUNS DECREASE THE RAIN
POTENTIAL FOR THE WESTERN COUNTIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 69 84 67 77 60 / 10 20 40 50 20
AUSTIN BERGSTROM INTL AIRPORT 68 84 66 78 60 / 10 20 40 50 20
NEW BRAUNFELS MUNI AIRPORT 66 84 67 80 59 / 10 20 40 50 20
BURNET MUNI AIRPORT 66 83 65 77 57 / 10 20 40 50 20
DEL RIO INTL AIRPORT 67 93 64 86 58 / 10 20 40 20 -
GEORGETOWN MUNI AIRPORT 66 81 65 76 58 / 10 20 40 50 20
HONDO MUNI AIRPORT 67 86 66 79 56 / 10 20 40 40 10
SAN MARCOS MUNI AIRPORT 67 84 67 79 60 / 10 20 40 50 20
LA GRANGE - FAYETTE REGIONAL 69 83 70 80 65 / 10 20 40 50 30
SAN ANTONIO INTL AIRPORT 69 84 68 79 58 / 10 20 40 40 10
STINSON MUNI AIRPORT 68 85 68 80 60 / 10 20 40 40 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...08
SYNOPTIC/GRIDS...25
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1134 PM CDT FRI MAR 30 2012
.AVIATION...
FOR THE 06Z TAFS...VFR CONDITIONS ARE ANTICIPATED AT KDHT AND KGUY.
THERE IS A VERY REMOTE POSSIBILITY OF MVFR OR IFR CONDITIONS AT KGUY
09-13Z...BUT CONFIDENCE OF OCCURRENCE IS TOO LOW TO MENTION AT THIS
TIME. AT KAMA...HAVE MODERATE TO HIGH CONFIDENCE OF MVFR...POSSIBLY
AS LOW AS LIFR...CONDITIONS DEVELOPING 09-13Z. OTHERWISE...VFR
CONDITIONS WILL PREVAIL.
JACKSON
&&
.PREV DISCUSSION... /ISSUED 525 PM CDT FRI MAR 30 2012/
AVIATION...
FOR THE 00Z TAFS...VFR CONDITIONS ARE ANTICIPATED. THERE IS A VERY
MINIMAL THREAT FOR IFR CIGS TO DEVELOP AT KAMA 09-14Z...BUT
THINK THESE SHOULD REMAIN EAST OF THE TAF SITE.
JACKSON
PREV DISCUSSION... /ISSUED 420 PM CDT FRI MAR 30 2012/
DISCUSSION...
RECORD OR NEAR RECORD HEAT EXPECTED THIS WEEKEND...FOLLOWED BY A COOL
DOWN...RAIN CHANCES...AND POSSIBLY STRONG NORTHERLY WINDS EARLY NEXT
WEEK.
FOR THE REST OF THIS AFTERNOON AND EVENING...REMOVED THE ISOLATED
THUNDERSTORM MENTION. STILL A GOOD AMOUNT OF LOW-LEVEL MOISTURE AND
POTENTIAL INSTABILITY ACROSS CENTRAL AND EASTERN AREAS...BUT DON/T
THINK WE/LL TAP INTO IT. LAPS AND RUC ANALYSIS DATA SHOW 75 J/KG OR
MORE OF CIN STILL IN PLACE ACROSS THE EAST...AND ANY FORCING FROM
MID-LEVEL SHORTWAVE WILL BE SHIFTING INTO WESTERN OK WITH SUBSIDENCE
BUILDING IN BEHIND THIS WAVE AND AHEAD OF SHORTWAVE RIDGE TO THE
WEST. VERY FLAT CU FIELD THAT GREW OUT OF THIS MORNING/S STRATUS
CONTINUES TO PUSH EASTWARD LATE THIS AFTERNOON IN ASSOCIATION WITH
WEAK LIFT FROM AFOREMENTIONED SHORTWAVE...WITH MAINLY CLEAR SKIES TO
THE WEST ASIDE FROM A FEW FAIR WEATHER CU. AFTER MIDNIGHT...MAY SEE
SOME FOG DEVELOP ONCE AGAIN. LOW-LEVELS WILL REMAIN MOIST AND WINDS
WILL BE LIGHT UNDER MOSTLY CLEAR SKIES...POTENTIALLY LEADING TO SOME
RADIATION FOG.
SHORTWAVE UPPER RIDGING WILL BE IN PLACE ON SUNDAY...WHILE A WEAK LEE
TROUGH DEVELOPS AT THE SURFACE. SOUTH/SOUTHWEST WINDS WILL RETURN BUT
LOOK TO REMAIN FAIRLY LIGHT /AOB 15 MPH/. SHOULD BE A NICE SPRING DAY
AS TEMPS CLIMB INTO THE 80S. RECORD HIGH OF 87F MAY FALL AT KDHT.
MODELS HAVE ALL COME ON BOARD WITH CLOSING OFF AN UPPER LOW AS THE
NEXT UPPER TROUGH WORKS ACROSS THE SOUTHERN ROCKIES. THIS LEADS TO A
SLOWER PROGRESSION OF THE UPPER SYSTEM...AND IN TURN...WINDS ON
SUNDAY STILL LOOKING WEAKER THAN ONCE THOUGHT EARLIER THIS WEEK. IT
WILL STILL BE WINDY AS THE SURFACE GRADIENT TIGHTENS IN RESPONSE TO A
DEVELOPING LOW OVER THE CENTRAL HIGH PLAINS...BUT CERTAINLY NOTHING
OUT OF THE ORDINARY FOR THIS PART OF THE COUNTRY. GENERALLY LOOKING AT
SOUTHWEST WINDS IN THE 20-30 MPH RANGE WITH GUSTS UP TO 40 MPH...AND
LIKELY A LITTLE WEAKER THAN THIS IN THE EAST. HIGHS EXPECTED TO SOAR
INTO THE UPPER 80S TO MID 90S...PUTTING RECORDS IN JEOPARDY AT
KAMA...KDHT...AND KBGD.
STRONG COLD FRONT IS EXPECTED TO PUSH THROUGH MONDAY...AND NORTH
WINDS MAY REACH ADVISORY LEVELS IN THE TIGHT GRADIENT. WILL SEE MUCH
COOLER TEMPS MONDAY WITH ACTUAL READINGS DEPENDING ON THE FRONTAL
TIMING...AND EVEN COOLER ON TUESDAY. QUESTION THEN BECOMES HOW LONG
THE CLOSED LOW WILL LINGER AROUND THE AREA. GFS AND CMC GEM ARE
FAIRLY PROGRESSIVE WITH THE SYSTEM...PUSHING IT EAST BY TUESDAY
NIGHT. LATEST ECMWF IS SLOWER...KEEPING POTENTIAL FOR WRAPAROUND RAIN
SHOWERS INTO WEDNESDAY. FOR NOW WILL BRING CHANCES FOR RAIN SHOWERS
INTO THE WEST MONDAY AFTERNOON...EXPAND THEM AREA WIDE MONDAY
NIGHT...AND THEN LINGER THEM IN THE NORTHEAST TUESDAY BEFORE DRYING
THINGS OUT TUESDAY NIGHT. ONCE THE UPPER LOW PULLS EAST...WILL SEE
REBOUNDING TEMPERATURES AND DRY CONDITIONS MID TO LATE NEXT WEEK.
KB
FIRE WEATHER...
VERY WARM TEMPERATURES CAN BE EXPECTED ACROSS THE PANHANDLES THIS
WEEKEND...WITH HIGHS FORECAST TO REACH THE 80S SATURDAY AND UPPER 80S
TO MID 90S SUNDAY. RELATIVE HUMIDITIES WILL FALL TO 10 TO 20 PERCENT
ACROSS THE WESTERN AND CENTRAL PANHANDLES SATURDAY...BUT WINDS ARE
FORECAST TO REMAIN BELOW 15 MPH...KEEPING FIRE WEATHER CONDITIONS
BELOW ELEVATED LEVELS. SOUTHWEST WINDS WILL INCREASE ON SUNDAY AS
SURFACE LOW PRESSURE DEVELOPS OVER THE CENTRAL HIGH PLAINS. A FIRE
WEATHER WATCH HAS BEEN ISSUED FOR THE WESTERN AND CENTRAL PANHANDLES
SUNDAY WHERE SOUTHWEST WINDS ARE EXPECTED TO INCREASE TO 20 TO 30 MPH
WITH HIGHER GUSTS. ACROSS THE EASTERN PANHANDLES...WINDS ARE FORECAST
TO BE SLIGHTLY WEAKER IN THE 15 TO 25 MPH RANGE. RELATIVE HUMIDITIES
WILL FALL TO 5 TO 15 PERCENT AREA WIDE. A STRONG COLD FRONT WILL MOVE
THROUGH ON MONDAY...WITH STRONG NORTH WINDS DEVELOPING BEHIND THE
FRONT. RELATIVE HUMIDITIES EXPECTED TO STAY AROUND 20 PERCENT OR
HIGHER DUE TO COOLER CONDITIONS...BUT THE WINDS WILL BE STRONG
LEADING TO ELEVATED FIRE WEATHER CONDITIONS. ELEVATED FIRE WEATHER
CONDITIONS MAY RETURN LATE NEXT WEEK AS TEMPERATURES WARM BACK UP AND
SOUTH/SOUTHWEST WINDS RETURN.
KB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES: ARMSTRONG...CARSON...DALLAM...DEAF
SMITH...HANSFORD...HARTLEY...HUTCHINSON...MOORE...OLDHAM...
POTTER...RANDALL...SHERMAN.
OK...FIRE WEATHER WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING
FOR THE FOLLOWING ZONES: CIMARRON...TEXAS.
&&
$$
JJ/JC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
218 PM EDT SAT MAR 31 2012
.SYNOPSIS...
A WEAK COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE MID APPALACHIAN
AND MID ATLANTIC REGION TODAY...ACCOMPANIED BY SCATTERED TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
SOUTHEAST INTO THE AREA LATER THIS AFTERNOON...AND PERSIST
THROUGH SUNDAY...ENDING THE THREAT FOR RAIN AS SKIES GRADUALLY
CLEAR.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1010 AM EDT SATURDAY...
THE COLD FRONT IS JUST ENTERING OUR SOUTHEAST WEST VIRGINIA
COUNTIES AS OF 10 AM...AS INDICATED BY FALLING DEWPOINT
TEMPERATURES AND PRESSURE RISES. WITH DRIER AIR MAKING ITS WAY
IN...CLOUD COVER WILL GRADUALLY BEGIN TO BREAK UP ACROSS OUR AREA
THROUGH THE AFTERNOON. MAIN CHANGES TO THE EARLY MORNING FORECAST
WERE TO LOWER AFTERNOON TEMPERATURES A DEGREE OR TWO ACROSS THE
PIEDMONTS...AREAS THAT WILL STILL EXPERIENCE RAIN SHOWERS THROUGH
AROUND NOON.
AS OF 335 AM EDT SATURDAY...
WEAK COOL FRONT PROGRESSING SOUTHEAST OUT OF THE OHIO VALLEY WILL
SWEEP SOUTHEAST THROUGH THE MOUNTAINS THIS MORNING...AND CONTINUE
EAST MOVING THROUGH THE PIEDMONT COUNTIES THIS AFTERNOON. LATEST
RUN OF THE HIGH RESOLUTION WRFARL AND HRRR MODELS DOING A VERY
GOOD JOB OF DEPICTING THE MOVEMENT...TIMING...AND AREAL COVERAGE
OF LINEAR SCATTERED CONVECTION IN THE VICINITY OF THE FRONT...WITH
MORE STRATIFORM AREA OF PRECIPITATION ADVANCING NORTHEAST THROUGH
THE SOUTHERN COUNTIES WHERE ISENTROPIC LIFT IS MAXIMIZED.
EXPECT TO SEE SOUTHERN STRATIFORM AREA OF PRECIPITATION MAINLY
SOUTH OF HIGHWAY 460 TO MOVE EAST OF THE BLACKSBURG FORECAST AREA
BY MID MORNING AS BEST ISENTROPIC LIFT MOVES EAST OF REGION...AND
AS LOWER TROPOSPHERIC WINDS GRADUALLY VEER INTO MORE OF A
DOWNSLOPING COMPONENT AS SURFACE LOW PRESSURE MOVES EAST TO THE
DELMARVA AREA.
MEANWHILE...FURTHER NW NEAR THE SURFACE FRONT...PAST SEVERAL HOURS
OF SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWING A MARKED
DECREASE OF CONVECTIVE ACTIVITY ALONG/NEAR FRONT DUE TO LIMITED
FORCING AND NEGLIGIBLE THERMODYNAMIC SUPPORT. SOME STRAY
SHOWERS/ISOLATED STORMS MAY REACH THE WESTERN TIER COUNTIES
SHORTLY BEFORE/AROUND DAYBREAK...SUPPORTED BY AT LEAST SOME
LIMITED UPSLOPING ALONG THE WESTERN FLANKS OF THE
APPALACHIANS...BUT ANY REIGNITING ALONG THE FRONT WILL LIKELY COME
LATER IN THE AFTERNOON AFTER THERMODYNAMIC SUPPORT INCREASES...AND
BY THEN...FRONT/SURFACE TROF LIKELY TO SOUTH AND EAST OF THE
BLACKSBURG FORECAST AREA.
DESPITE ARRIVAL AND PASSAGE OF FRONT AND ASSOCIATED CLOUDS...LITTLE
CHANGE IN AIR MASS IS EXPECTED DURING THE DAY SINCE DEEPER COOL
AIR LAGS WELL BEHIND WIND SHIFT. COMBINATION OF LINGERING CLOUDS
IN UPSLOPE AREAS OF THE WEST AND AT LEAST A FEW DEGREE REDUCTION
IN 850 MILLIBAR TEMPERATURE SHOULD PREVENT AFTERNOON READINGS
FROM REACHING THOSE EXPERIENCED ON FRIDAY. HOWEVER...DOWNSLOPING
WINDS FOLLOWING PASSAGE OF FRONT/TROF MAY VERY WELL ALLOW FOR A WARMER
DAY ACROSS MUCH OF THE PIEDMONT. ALL AND ALL...EXPECT TEMPERATURES
TO CONTINUE TO BE 10-15 DEGREES ABOVE NORMAL FOR THE LAST DAY OF
THE MONTH...GENERALLY 60S ACROSS THE WESTERN MOUNTAINS TO NEAR 80
ACROSS THE PIEDMONT. THIS WILL ENSURE THAT MOST CLIMATOLOGICAL
SITES END UP BREAKING OR BEING IN THE TOP SEVERAL WARMEST MARCHES
ON RECORD.
DRY SURFACE RIDGE OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND
WEST TONIGHT SHOULD ALLOW FOR CLEARING SKIES WITH GOOD RADIATIVE
COOLING POTENTIAL. READINGS SHORTLY BEFORE DAYBREAK ON SUNDAY
EXPECTED TO RANGE FROM THE MID 30S TO LOWER 40S IN THE
MOUNTAINS...WHERE SOME PATCHY FROST MAY OCCUR IN SOME OF THE
DEEPER MOUNTAIN VALLEYS...TO THE MID AND UPPER 40S ACROSS THE
PIEDMONT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM EDT SATURDAY...
ON SUNDAY...WE ARE EXPECTING HIGH PRESSURE TO SETTLE OVER THE AREA
BY THE MORNING. A STRONGER NOSE OF HIGH PRESSURE IS EXPECTED TO HEAD
SOUTH THROUGH THE GREAT LAKES AREA LATER IN THE DAY. THIS FEATURE
MAY PROMPT A BACK DOOR COLD FRONT INTO THE AREA...WITH THE POTENTIAL
FOR SOME ISOLATED SHOWERS ALONG IT LATE IN THE AFTERNOON INTO SUNDAY
EVENING. AS THE BACK DOOR FRONT CONTINUES SOUTH THROUGH THE AREA
SUNDAY NIGHT...ANTICIPATE ISOLATED COVERAGE ACROSS
WESTERN...NORTHERN...AND EASTERN SECTIONS OF THE REGION. COVERAGE
MAY SCATTERED OVER SECTIONS OF SOUTHEAST WEST VIRGINIA.
THIS FRONT WILL BECOME STALLED OVER THE WESTERN THIRD OF THE AREA BY
MONDAY MORNING. DURING THE DAY MONDAY...AN AREA OF LOW PRESSURE WILL
BE MOVING EASTWARD THROUGH THE CENTRAL PART OF THE U.S. WIND FLOW
IN ADVANCE OF THIS FEATURE WILL TURN SOUTHERLY ACROSS THE WESTERN
GULF OF MEXICO...AND ADVECT INTO OUR REGION FROM THE SOUTHWEST. THE
RESULT WILL BE INCREASING COVERAGE OF SHOWERS ALONG THE STALLED
FRONT THANKS TO THE INCREASED MOISTURE. THE FRONT ITSELF WILL ALSO
TAKE ON MORE OF THE NATURE OF A WARM FRONT AND HEAD ACROSS THE AREA
BY MONDAY NIGHT.
ON TUESDAY...THE LOW WILL HEAD EASTWARD NEAR THE PA/MD LINE AND ITS
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE AREA. WE ARE
ANTICIPATING INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS DURING
THE DAY...ESPECIALLY ACROSS THE MOUNTAINS. AREAS ALONG AND EAST OF A
FARMVILLE TO DANVILLE LINE MAY NOT SEE ANY ACTIVITY UNTIL TUESDAY
EVENING. BY TUESDAY NIGHT... MOST OF THE PRECIPITATION WILL BE SOUTH
OF THE AREA IN ASSOCIATION WITH THE COLD FRONT. LINGERING SHOWERS
WILL STILL BE POSSIBLE ACROSS THE AREA...ESPECIALLY OVER SOUTHEAST
WV WHERE NORTHWEST FLOW UPSLOPE SHOWERS ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
WITH THE COLD FRONT PASSING THROUGH OUR AREA ON TUESDAY NIGHT AND
WEDNESDAY MORNING...EXPECT ANOTHER LARGE DOME OF CANADIAN HIGH
PRESSURE TO BUILD INTO THE UPPER MIDWEST...BRINGING OUR TEMPERATURES
MUCH CLOSER TO NORMAL FOR THE FIRST WEEK OF APRIL. WITH HIGH
PRESSURE MAINTAINING ITS CONTROL THROUGH THE BEGINNING OF NEXT
WEEKEND...THE ONLY WEATHER CONCERNS WILL BE CHILLY OVERNIGHT
TEMPERATURES...WHICH MAY APPROACH FREEZING ACROSS PARTS OF SOUTHEAST
WEST VIRGINIA...AND MAY RESULT IN OVERNIGHT FROST ELSEWHERE ACROSS
THE MOUNTAINS.
&&
.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT SATURDAY...
ALL AIRPORTS ARE REPORTING VFR CONDITIONS THIS AFTERNOON UNDER A
BROKEN LAYER OF STRATOCU...WITH BASES RANGING FROM 4KFT TO 7KFT...
AS AN EAST TO WEST COLD FRONT PUSHES SOUTH THROUGH THE FORECAST
REGION. SATELLITE IMAGERY HAS INDICATED SOME OF THE STRATOCU
BUBBLING UPWARD AHEAD OF THE FRONT WITH THE DAYTIME HEATING...AND
WOULD NOT BE SURPRISED IF A FEW SHOWERS...AND POSSIBLY
THUNDERSTORMS...DEVELOP BY MID AFTERNOON. ANY SHOWERS OR STORMS
WHICH DO DEVELOP WILL MOVE EAST OF OUR AREA BY LATE AFTERNOON OR
EARLY EVENING AS THE COLD FRONT EXITS TO THE SOUTHEAST.
A WEAK RIDGE OF HIGH PRESSURE WILL CONTINUE TO BUILD IN BEHIND THE
COLD FRONT THROUGH THE NIGHT. EXPECT VFR CONDITIONS TO PERSIST AT
ROA...LYH AND DAN. HOWEVER...CONCERNED WITH THE POSSIBILITY OF FOG
AND LOW CIGS FURTHER WEST. THE NAM FORECAST MODEL HOLDS LIGHT
NORTHWEST FLOW IN AT BLF OVERNIGHT...AND CONSIDERING THE RESIDUAL
LOW LEVEL MOISTURE FOUND ACROSS WEST VIRGINIA...BELIEVE THERE IS A
POSSIBILITY OF LOW CLOUDS REDEVELOPING BENEATH THE INVERSION OVER
THE AIRPORT AFTER MIDNIGHT. ALSO...WITH ADVECTION NEUTRALIZING SHORTLY
BEFORE SUNRISE ACROSS THE MOUNTAINS...INTRODUCED A PERIOD OF LOW
VISIBILITIES FOR BCB AND LWB FOR THE 01/09Z TO 01/13Z TIMEFRAME.
WITH SOUTHERLY FLOW TAKING OVER BY LATE SUNDAY MORNING...DAYTIME
HEATING WILL HELP MVFR AND IFR CONDITIONS IMPROVE RAPIDLY.
THE NEXT THREAT FOR WIDESPREAD FLIGHT RESTRICTIONS WILL OCCUR
LATE SUNDAY NIGHT OR ON MONDAY...POSSIBLY CONTINUING INTO THE MID
WEEK PERIOD AS ANOTHER RIDGE OF HIGH PRESSURE BUILDS SOUTHWEST OUT
OF NEW ENGLAND. UPSLOPING WINDS ACROSS THE EASTERN FLANKS OF THE
BLUE RIDGE...WITH WEAK SHORT WAVES AND MOISTURE STREAMING
NORTHEAST OVER A STALLED FRONT OVER/NEAR THE AREA...MAY SET THE
STAGE FOR MVFR (AND POTENTIALLY LOWER) FLIGHT RESTRICTIONS INTO
THE MID WEEK PERIOD...ESPECIALLY OVER/IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WERT
NEAR TERM...NF/WERT
SHORT TERM...DS
LONG TERM...NF
AVIATION...NF/WERT
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1020 AM EDT SAT MAR 31 2012
.SYNOPSIS...
A WEAK COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE MID APPALACHIAN
AND MID ATLANTIC REGION TODAY...ACCOMPANIED BY SCATTERED TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
SOUTHEAST INTO THE AREA LATER THIS AFTERNOON...AND PERSIST
THROUGH SUNDAY...ENDING THE THREAT FOR RAIN AS SKIES GRADUALLY
CLEAR.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1010 AM EDT SATURDAY...
THE COLD FRONT IS JUST ENTERING OUR SOUTHEAST WEST VIRGINIA
COUNTIES AS OF 10 AM...AS INDICATED BY FALLING DEWPOINT
TEMPERATURES AND PRESSURE RISES. WITH DRIER AIR MAKING ITS WAY
IN...CLOUD COVER WILL GRADUALLY BEGIN TO BREAK UP ACROSS OUR AREA
THROUGH THE AFTERNOON. MAIN CHANGES TO THE EARLY MORNING FORECAST
WERE TO LOWER AFTERNOON TEMPERATURES A DEGREE OR TWO ACROSS THE
PIEDMONTS...AREAS THAT WILL STILL EXPERIENCE RAIN SHOWERS THROUGH
AROUND NOON.
AS OF 335 AM EDT SATURDAY...
WEAK COOL FRONT PROGRESSING SOUTHEAST OUT OF THE OHIO VALLEY WILL
SWEEP SOUTHEAST THROUGH THE MOUNTAINS THIS MORNING...AND CONTINUE
EAST MOVING THROUGH THE PIEDMONT COUNTIES THIS AFTERNOON. LATEST
RUN OF THE HIGH RESOLUTION WRFARL AND HRRR MODELS DOING A VERY
GOOD JOB OF DEPICTING THE MOVEMENT...TIMING...AND AREAL COVERAGE
OF LINEAR SCATTERED CONVECTION IN THE VICINITY OF THE FRONT...WITH
MORE STRATIFORM AREA OF PRECIPITATION ADVANCING NORTHEAST THROUGH
THE SOUTHERN COUNTIES WHERE ISENTROPIC LIFT IS MAXIMIZED.
EXPECT TO SEE SOUTHERN STRATIFORM AREA OF PRECIPITATION MAINLY
SOUTH OF HIGHWAY 460 TO MOVE EAST OF THE BLACKSBURG FORECAST AREA
BY MID MORNING AS BEST ISENTROPIC LIFT MOVES EAST OF REGION...AND
AS LOWER TROPOSPHERIC WINDS GRADUALLY VEER INTO MORE OF A
DOWNSLOPING COMPONENT AS SURFACE LOW PRESSURE MOVES EAST TO THE
DELMARVA AREA.
MEANWHILE...FURTHER NW NEAR THE SURFACE FRONT...PAST SEVERAL HOURS
OF SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWING A MARKED
DECREASE OF CONVECTIVE ACTIVITY ALONG/NEAR FRONT DUE TO LIMITED
FORCING AND NEGLIGIBLE THERMODYNAMIC SUPPORT. SOME STRAY
SHOWERS/ISOLATED STORMS MAY REACH THE WESTERN TIER COUNTIES
SHORTLY BEFORE/AROUND DAYBREAK...SUPPORTED BY AT LEAST SOME
LIMITED UPSLOPING ALONG THE WESTERN FLANKS OF THE
APPALACHIANS...BUT ANY REIGNITING ALONG THE FRONT WILL LIKELY COME
LATER IN THE AFTERNOON AFTER THERMODYNAMIC SUPPORT INCREASES...AND
BY THEN...FRONT/SURFACE TROF LIKELY TO SOUTH AND EAST OF THE
BLACKSBURG FORECAST AREA.
DESPITE ARRIVAL AND PASSAGE OF FRONT AND ASSOCIATED CLOUDS...LITTLE
CHANGE IN AIR MASS IS EXPECTED DURING THE DAY SINCE DEEPER COOL
AIR LAGS WELL BEHIND WIND SHIFT. COMBINATION OF LINGERING CLOUDS
IN UPSLOPE AREAS OF THE WEST AND AT LEAST A FEW DEGREE REDUCTION
IN 850 MILLIBAR TEMPERATURE SHOULD PREVENT AFTERNOON READINGS
FROM REACHING THOSE EXPERIENCED ON FRIDAY. HOWEVER...DOWNSLOPING
WINDS FOLLOWING PASSAGE OF FRONT/TROF MAY VERY WELL ALLOW FOR A WARMER
DAY ACROSS MUCH OF THE PIEDMONT. ALL AND ALL...EXPECT TEMPERATURES
TO CONTINUE TO BE 10-15 DEGREES ABOVE NORMAL FOR THE LAST DAY OF
THE MONTH...GENERALLY 60S ACROSS THE WESTERN MOUNTAINS TO NEAR 80
ACROSS THE PIEDMONT. THIS WILL ENSURE THAT MOST CLIMATOLOGICAL
SITES END UP BREAKING OR BEING IN THE TOP SEVERAL WARMEST MARCHES
ON RECORD.
DRY SURFACE RIDGE OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND
WEST TONIGHT SHOULD ALLOW FOR CLEARING SKIES WITH GOOD RADIATIVE
COOLING POTENTIAL. READINGS SHORTLY BEFORE DAYBREAK ON SUNDAY
EXPECTED TO RANGE FROM THE MID 30S TO LOWER 40S IN THE
MOUNTAINS...WHERE SOME PATCHY FROST MAY OCCUR IN SOME OF THE
DEEPER MOUNTAIN VALLEYS...TO THE MID AND UPPER 40S ACROSS THE
PIEDMONT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM EDT SATURDAY...
ON SUNDAY...WE ARE EXPECTING HIGH PRESSURE TO SETTLE OVER THE AREA
BY THE MORNING. A STRONGER NOSE OF HIGH PRESSURE IS EXPECTED TO HEAD
SOUTH THROUGH THE GREAT LAKES AREA LATER IN THE DAY. THIS FEATURE
MAY PROMPT A BACK DOOR COLD FRONT INTO THE AREA...WITH THE POTENTIAL
FOR SOME ISOLATED SHOWERS ALONG IT LATE IN THE AFTERNOON INTO SUNDAY
EVENING. AS THE BACK DOOR FRONT CONTINUES SOUTH THROUGH THE AREA
SUNDAY NIGHT...ANTICIPATE ISOLATED COVERAGE ACROSS
WESTERN...NORTHERN...AND EASTERN SECTIONS OF THE REGION. COVERAGE
MAY SCATTERED OVER SECTIONS OF SOUTHEAST WEST VIRGINIA.
THIS FRONT WILL BECOME STALLED OVER THE WESTERN THIRD OF THE AREA BY
MONDAY MORNING. DURING THE DAY MONDAY...AN AREA OF LOW PRESSURE WILL
BE MOVING EASTWARD THROUGH THE CENTRAL PART OF THE U.S. WIND FLOW
IN ADVANCE OF THIS FEATURE WILL TURN SOUTHERLY ACROSS THE WESTERN
GULF OF MEXICO...AND ADVECT INTO OUR REGION FROM THE SOUTHWEST. THE
RESULT WILL BE INCREASING COVERAGE OF SHOWERS ALONG THE STALLED
FRONT THANKS TO THE INCREASED MOISTURE. THE FRONT ITSELF WILL ALSO
TAKE ON MORE OF THE NATURE OF A WARM FRONT AND HEAD ACROSS THE AREA
BY MONDAY NIGHT.
ON TUESDAY...THE LOW WILL HEAD EASTWARD NEAR THE PA/MD LINE AND ITS
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE AREA. WE ARE
ANTICIPATING INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS DURING
THE DAY...ESPECIALLY ACROSS THE MOUNTAINS. AREAS ALONG AND EAST OF A
FARMVILLE TO DANVILLE LINE MAY NOT SEE ANY ACTIVITY UNTIL TUESDAY
EVENING. BY TUESDAY NIGHT... MOST OF THE PRECIPITATION WILL BE SOUTH
OF THE AREA IN ASSOCIATION WITH THE COLD FRONT. LINGERING SHOWERS
WILL STILL BE POSSIBLE ACROSS THE AREA...ESPECIALLY OVER SOUTHEAST
WV WHERE NORTHWEST FLOW UPSLOPE SHOWERS ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
WITH THE COLD FRONT PASSING THROUGH OUR AREA ON TUESDAY NIGHT AND
WEDNESDAY MORNING...EXPECT ANOTHER LARGE DOME OF CANADIAN HIGH
PRESSURE TO BUILD INTO THE UPPER MIDWEST...BRINGING OUR TEMPERATURES
MUCH CLOSER TO NORMAL FOR THE FIRST WEEK OF APRIL. WITH HIGH
PRESSURE MAINTAINING ITS CONTROL THROUGH THE BEGINNING OF NEXT
WEEKEND...THE ONLY WEATHER CONCERNS WILL BE CHILLY OVERNIGHT
TEMPERATURES...WHICH MAY APPROACH FREEZING ACROSS PARTS OF SOUTHEAST
WEST VIRGINIA...AND MAY RESULT IN OVERNIGHT FROST ELSEWHERE ACROSS
THE MOUNTAINS.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 735 AM EDT SATURDAY...
COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE SOUTHEASTERN WV
TERMINAL FORECAST POINTS THIS MORNING...AND MOVE EAST OF THE
PIEDMONT TERMINAL FORECAST POINTS BY EARLY TO MID AFTERNOON.
UPSLOPING WINDS ACROSS THE WESTERN FLANKS OF THE APPALACHIANS WILL
RESULT IN AREAS OF MVFR FLIGHT RESTRICTIONS...WITH LOCALIZED IFR
CONDITIONS ALONG WITH MOUNTAIN TOP OBSCURATIONS INTO MID MORNING...
ESPECIALLY SOUTH OF BLUEFIELD INTO THE NW NC MOUNTAINS...WHERE
RAIN FELL OVERNIGHT. ELSEWHERE...VEERING WINDS IN LOWER TROPOSPHERE
AS LOW PRESSURE MOVES EAST AND OFF DELMARVA COASTLINE WILL RESULT
IN DEVELOPMENT OF DOWNSLOPING WINDS EAST OF THE BLUE RIDGE...
ENSURING THAT MAINLY VFR CONDITIONS PREVAIL IN THIS AREA DESPITE
SOME SHOWERS INTO MID MORNING SOUTH OF HIGHWAY 460.
SURFACE RIDGE OF HIGH PRESSURE BUILDING SOUTHEAST INTO THE MID
APPALACHIAN AND MID ATLANTIC REGION...AND ARRIVAL OF DRIER AIR
THIS AFTERNOON INTO SUNDAY SHOULD ENSURE CLEARING CONDITIONS WITH
VFR WEATHER TO RETURN TO EVEN THE WESTERN UPSLOPE AREAS BY EARLY
TO MID AFTERNOON.
THE NEXT THREAT FOR WIDESPREAD FLIGHT RESTRICTIONS WILL OCCUR
LATE SUNDAY NIGHT OR ON MONDAY...POSSIBLY CONTINUING INTO THE MID
WEEK PERIOD AS ANOTHER RIDGE OF HIGH PRESSURE BUILDS SOUTHWEST OUT
OF NEW ENGLAND. UPSLOPING WINDS ACROSS THE EASTERN FLANKS OF THE
BLUE RIDGE...WITH WEAK SHORT WAVES AND MOISTURE STREAMING
NORTHEAST OVER A STALLED FRONT OVER/NEAR THE AREA...MAY SET THE
STAGE FOR MVFR (AND POTENTIALLY LOWER) FLIGHT RESTRICTIONS INTO
THE MID WEEK PERIOD...ESPECIALLY OVER/IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WERT
NEAR TERM...NF/WERT
SHORT TERM...DS
LONG TERM...NF
AVIATION...WERT
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
739 AM EDT SAT MAR 31 2012
.SYNOPSIS...
A WEAK COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE MID APPALACHIAN
AND MID ATLANTIC REGION TODAY...ACCOMPANIED BY SCATTERED TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
SOUTHEAST INTO THE AREA LATER THIS AFTERNOON...AND PERSIST
THROUGH SUNDAY...ENDING THE THREAT FOR RAIN AS SKIES GRADUALLY
CLEAR.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 335 AM EDT SATURDAY...
WEAK COOL FRONT PROGRESSING SOUTHEAST OUT OF THE OHIO VALLEY WILL
SWEEP SOUTHEAST THROUGH THE MOUNTAINS THIS MORNING...AND CONTINUE
EAST MOVING THROUGH THE PIEDMONT COUNTIES THIS AFTERNOON. LATEST
RUN OF THE HIGH RESOLUTION WRFARL AND HRRR MODELS DOING A VERY
GOOD JOB OF DEPICTING THE MOVEMENT...TIMING...AND AREAL COVERAGE
OF LINEAR SCATTERED CONVECTION IN THE VICINITY OF THE FRONT...WITH
MORE STRATIFORM AREA OF PRECIPITATION ADVANCING NORTHEAST THROUGH
THE SOUTHERN COUNTIES WHERE ISENTROPIC LIFT IS MAXIMIZED.
EXPECT TO SEE SOUTHERN STRATIFORM AREA OF PRECIPITATION MAINLY
SOUTH OF HIGHWAY 460 TO MOVE EAST OF THE BLACKSBURG FORECAST AREA
BY MID MORNING AS BEST ISENTROPIC LIFT MOVES EAST OF REGION...AND
AS LOWER TROPOSPHERIC WINDS GRADUALLY VEER INTO MORE OF A
DOWNSLOPING COMPONENT AS SURFACE LOW PRESSURE MOVES EAST TO THE
DELMARVA AREA.
MEANWHILE...FURTHER NW NEAR THE SURFACE FRONT...PAST SEVERAL HOURS
OF SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWING A MARKED
DECREASE OF CONVECTIVE ACTIVITY ALONG/NEAR FRONT DUE TO LIMITED
FORCING AND NEGLIGIBLE THERMODYNAMIC SUPPORT. SOME STRAY
SHOWERS/ISOLATED STORMS MAY REACH THE WESTERN TIER COUNTIES
SHORTLY BEFORE/AROUND DAYBREAK...SUPPORTED BY AT LEAST SOME
LIMITED UPSLOPING ALONG THE WESTERN FLANKS OF THE
APPALACHIANS...BUT ANY REIGNITING ALONG THE FRONT WILL LIKELY COME
LATER IN THE AFTERNOON AFTER THERMODYNAMIC SUPPORT INCREASES...AND
BY THEN...FRONT/SURFACE TROF LIKELY TO SOUTH AND EAST OF THE
BLACKSBURG FORECAST AREA.
DESPITE ARRIVAL AND PASSAGE OF FRONT AND ASSOCIATED CLOUDS...LITTLE
CHANGE IN AIR MASS IS EXPECTED DURING THE DAY SINCE DEEPER COOL
AIR LAGS WELL BEHIND WIND SHIFT. COMBINATION OF LINGERING CLOUDS
IN UPSLOPE AREAS OF THE WEST AND AT LEAST A FEW DEGREE REDUCTION
IN 850 MILLIBAR TEMPERATURE SHOULD PREVENT AFTERNOON READINGS
FROM REACHING THOSE EXPERIENCED ON FRIDAY. HOWEVER...DOWNSLOPING
WINDS FOLLOWING PASSAGE OF FRONT/TROF MAY VERY WELL ALLOW FOR A WARMER
DAY ACROSS MUCH OF THE PIEDMONT. ALL AND ALL...EXPECT TEMPERATURES
TO CONTINUE TO BE 10-15 DEGREES ABOVE NORMAL FOR THE LAST DAY OF
THE MONTH...GENERALLY 60S ACROSS THE WESTERN MOUNTAINS TO NEAR 80
ACROSS THE PIEDMONT. THIS WILL ENSURE THAT MOST CLIMATOLOGICAL
SITES END UP BREAKING OR BEING IN THE TOP SEVERAL WARMEST MARCHES
ON RECORD.
DRY SURFACE RIDGE OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND
WEST TONIGHT SHOULD ALLOW FOR CLEARING SKIES WITH GOOD RADIATIVE
COOLING POTENTIAL. READINGS SHORTLY BEFORE DAYBREAK ON SUNDAY
EXPECTED TO RANGE FROM THE MID 30S TO LOWER 40S IN THE
MOUNTAINS...WHERE SOME PATCHY FROST MAY OCCUR IN SOME OF THE
DEEPER MOUNTAIN VALLEYS...TO THE MID AND UPPER 40S ACROSS THE
PIEDMONT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM EDT SATURDAY...
ON SUNDAY...WE ARE EXPECTING HIGH PRESSURE TO SETTLE OVER THE AREA
BY THE MORNING. A STRONGER NOSE OF HIGH PRESSURE IS EXPECTED TO HEAD
SOUTH THROUGH THE GREAT LAKES AREA LATER IN THE DAY. THIS FEATURE
MAY PROMPT A BACK DOOR COLD FRONT INTO THE AREA...WITH THE POTENTIAL
FOR SOME ISOLATED SHOWERS ALONG IT LATE IN THE AFTERNOON INTO SUNDAY
EVENING. AS THE BACK DOOR FRONT CONTINUES SOUTH THROUGH THE AREA
SUNDAY NIGHT...ANTICIPATE ISOLATED COVERAGE ACROSS
WESTERN...NORTHERN...AND EASTERN SECTIONS OF THE REGION. COVERAGE
MAY SCATTERED OVER SECTIONS OF SOUTHEAST WEST VIRGINIA.
THIS FRONT WILL BECOME STALLED OVER THE WESTERN THIRD OF THE AREA BY
MONDAY MORNING. DURING THE DAY MONDAY...AN AREA OF LOW PRESSURE WILL
BE MOVING EASTWARD THROUGH THE CENTRAL PART OF THE U.S. WIND FLOW
IN ADVANCE OF THIS FEATURE WILL TURN SOUTHERLY ACROSS THE WESTERN
GULF OF MEXICO...AND ADVECT INTO OUR REGION FROM THE SOUTHWEST. THE
RESULT WILL BE INCREASING COVERAGE OF SHOWERS ALONG THE STALLED
FRONT THANKS TO THE INCREASED MOISTURE. THE FRONT ITSELF WILL ALSO
TAKE ON MORE OF THE NATURE OF A WARM FRONT AND HEAD ACROSS THE AREA
BY MONDAY NIGHT.
ON TUESDAY...THE LOW WILL HEAD EASTWARD NEAR THE PA/MD LINE AND ITS
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE AREA. WE ARE
ANTICIPATING INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS DURING
THE DAY...ESPECIALLY ACROSS THE MOUNTAINS. AREAS ALONG AND EAST OF A
FARMVILLE TO DANVILLE LINE MAY NOT SEE ANY ACTIVITY UNTIL TUESDAY
EVENING. BY TUESDAY NIGHT... MOST OF THE PRECIPITATION WILL BE SOUTH
OF THE AREA IN ASSOCIATION WITH THE COLD FRONT. LINGERING SHOWERS
WILL STILL BE POSSIBLE ACROSS THE AREA...ESPECIALLY OVER SOUTHEAST
WV WHERE NORTHWEST FLOW UPSLOPE SHOWERS ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
WITH THE COLD FRONT PASSING THROUGH OUR AREA ON TUESDAY NIGHT AND
WEDNESDAY MORNING...EXPECT ANOTHER LARGE DOME OF CANADIAN HIGH
PRESSURE TO BUILD INTO THE UPPER MIDWEST...BRINGING OUR TEMPERATURES
MUCH CLOSER TO NORMAL FOR THE FIRST WEEK OF APRIL. WITH HIGH
PRESSURE MAINTAINING ITS CONTROL THROUGH THE BEGINNING OF NEXT
WEEKEND...THE ONLY WEATHER CONCERNS WILL BE CHILLY OVERNIGHT
TEMPERATURES...WHICH MAY APPROACH FREEZING ACROSS PARTS OF SOUTHEAST
WEST VIRGINIA...AND MAY RESULT IN OVERNIGHT FROST ELSEWHERE ACROSS
THE MOUNTAINS.
&&
.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
AS OF 735 AM EDT SATURDAY...
COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE SOUTHEASTERN WV
TERMINAL FORECAST POINTS THIS MORNING...AND MOVE EAST OF THE
PIEDMONT TERMINAL FORECAST POINTS BY EARLY TO MID AFTERNOON.
UPSLOPING WINDS ACROSS THE WESTERN FLANKS OF THE APPALACHIANS WILL
RESULT IN AREAS OF MVFR FLIGHT RESTRICTIONS...WITH LOCALIZED IFR
CONDITIONS ALONG WITH MOUNTAIN TOP OBSCURATIONS INTO MID MORNING...
ESPECIALLY SOUTH OF BLUEFIELD INTO THE NW NC MOUNTAINS...WHERE
RAIN FELL OVERNIGHT. ELSEWHERE...VEERING WINDS IN LOWER TROPOSPHERE
AS LOW PRESSURE MOVES EAST AND OFF DELMARVA COASTLINE WILL RESULT
IN DEVELOPMENT OF DOWNSLOPING WINDS EAST OF THE BLUE RIDGE...
ENSURING THAT MAINLY VFR CONDITIONS PREVAIL IN THIS AREA DESPITE
SOME SHOWERS INTO MID MORNING SOUTH OF HIGHWAY 460.
SURFACE RIDGE OF HIGH PRESSURE BUILDING SOUTHEAST INTO THE MID
APPALACHIAN AND MID ATLANTIC REGION...AND ARRIVAL OF DRIER AIR
THIS AFTERNOON INTO SUNDAY SHOULD ENSURE CLEARING CONDITIONS WITH
VFR WEATHER TO RETURN TO EVEN THE WESTERN UPSLOPE AREAS BY EARLY
TO MID AFTERNOON.
THE NEXT THREAT FOR WIDESPREAD FLIGHT RESTRICTIONS WILL OCCUR
LATE SUNDAY NIGHT OR ON MONDAY...POSSIBLY CONTINUING INTO THE MID
WEEK PERIOD AS ANOTHER RIDGE OF HIGH PRESSURE BUILDS SOUTHWEST OUT
OF NEW ENGLAND. UPSLOPING WINDS ACROSS THE EASTERN FLANKS OF THE
BLUE RIDGE...WITH WEAK SHORT WAVES AND MOISTURE STREAMING
NORTHEAST OVER A STALLED FRONT OVER/NEAR THE AREA...MAY SET THE
STAGE FOR MVFR (AND POTENTIALLY LOWER) FLIGHT RESTRICTIONS INTO
THE MID WEEK PERIOD...ESPECIALLY OVER/IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WERT
NEAR TERM...WERT
SHORT TERM...DS
LONG TERM...NF
AVIATION...WERT
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
339 AM EDT SAT MAR 31 2012
.SYNOPSIS...
A WEAK COOL FRONT WILL SWEEP SOUTHEAST THROUGH THE MID APPALACHIAN
AND MID ATLANTIC REGION TODAY...ACCOMPANIED BY SCATTERED TO WIDELY
SCATTERED SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
SOUTHEAST INTO THE AREA LATER THIS AFTERNOON...AND PERSIST
THROUGH SUNDAY...ENDING THE THREAT FOR RAIN AS SKIES GRADUALLY
CLEAR.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 335 AM EDT SATURDAY...
WEAK COOL FRONT PROGRESSING SOUTHEAST OUT OF THE OHIO VALLEY WILL
SWEEP SOUTHEAST THROUGH THE MOUNTAINS THIS MORNING...AND CONTINUE
EAST MOVING THROUGH THE PIEDMONT COUNTIES THIS AFTERNOON. LATEST
RUN OF THE HIGH RESOLUTION WRFARL AND HRRR MODELS DOING A VERY
GOOD JOB OF DEPICTING THE MOVEMENT...TIMING...AND AREAL COVERAGE
OF LINEAR SCATTERED CONVECTION IN THE VICINITY OF THE FRONT...WITH
MORE STRATIFORM AREA OF PRECIPITATION ADVANCING NORTHEAST THROUGH
THE SOUTHERN COUNTIES WHERE ISENTROPIC LIFT IS MAXIMIZED.
EXPECT TO SEE SOUTHERN STRATIFORM AREA OF PRECIPITATION MAINLY
SOUTH OF HIGHWAY 460 TO MOVE EAST OF THE BLACKSBURG FORECAST AREA
BY/SHORTLY AFTER DAYBREAK AS BEST ISENTROPIC LIFT MOVES EAST OF
REGION...AND AS LOWER TROPOSPHERIC WINDS GRADUALLY VEER INTO MORE
OF A DOWNSLOPING COMPONENT AS SURFACE LOW PRESSURE MOVES EAST TO
THE DELMARVA AREA.
MEANWHILE...FURTHER NW NEAR THE SURFACE FRONT...PAST SEVERAL HOURS
OF SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWING A MARKED
DECREASE OF CONVECTIVE ACTIVITY ALONG/NEAR FRONT DUE TO LIMITED
FORCING AND NEGLIGIBLE THERMODYNAMIC SUPPORT. SOME STRAY
SHOWERS/ISOLATED STORMS MAY REACH THE WESTERN TIER COUNTIES
SHORTLY BEFORE/AROUND DAYBREAK...SUPPORTED BY AT LEAST SOME
LIMITED UPSLOPING ALONG THE WESTERN FLANKS OF THE
APPALACHIANS...BUT ANY REIGNITING ALONG THE FRONT WILL LIKELY COME
LATER IN THE AFTERNOON AFTER THERMODYNAMIC SUPPORT INCREASES...AND
BY THEN...FRONT/SURFACE TROF LIKELY TO SOUTH AND EAST OF THE
BLACKSBURG FORECAST AREA.
DESPITE ARRIVAL AND PASSAGE OF FRONT AND ASSOCIATED CLOUDS...LITTLE
CHANGE IN AIR MASS IS EXPECTED DURING THE DAY SINCE DEEPER COOL
AIR LAGS WELL BEHIND WIND SHIFT. COMBINATION OF LINGERING CLOUDS
IN UPSLOPE AREAS OF THE WEST AND AT LEAST A FEW DEGREE REDUCTION
IN 850 MILLIBAR TEMPERATURE SHOULD PREVENT AFTERNOON READINGS
FROM REACHING THOSE EXPERIENCED ON FRIDAY. HOWEVER...DOWNSLOPING
WINDS FOLLOWING PASSAGE OF FRONT/TROF MAY VERY WELL ALLOW FOR A WARMER
DAY ACROSS MUCH OF THE PIEDMONT. ALL AND ALL...EXPECT TEMPERATURES
TO CONTINUE TO BE 10-15 DEGREES ABOVE NORMAL FOR THE LAST DAY OF
THE MONTH...GENERALLY 60S ACROSS THE WESTERN MOUNTAINS TO NEAR 80
ACROSS THE PIEDMONT. THIS WILL ENSURE THAT MOST CLIMATOLOGICAL
SITES END UP BREAKING OR BEING IN THE TOP SEVERAL WARMEST MARCHES
ON RECORD.
DRY SURFACE RIDGE OF HIGH PRESSURE BUILDING IN FROM THE NORTH AND
WEST TONIGHT SHOULD ALLOW FOR CLEARING SKIES WITH GOOD RADIATIVE
COOLING POTENTIAL. READINGS SHORTLY BEFORE DAYBREAK ON SUNDAY
EXPECTED TO RANGE FROM THE MID 30S TO LOWER 40S IN THE
MOUNTAINS...WHERE SOME PATCHY FROST MAY OCCUR IN SOME OF THE
DEEPER MOUNTAIN VALLEYS...TO THE MID AND UPPER 40S ACROSS THE
PIEDMONT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
AS OF 300 AM EDT SATURDAY...
ON SUNDAY...WE ARE EXPECTING HIGH PRESSURE TO SETTLE OVER THE AREA
BY THE MORNING. A STRONGER NOSE OF HIGH PRESSURE IS EXPECTED TO HEAD
SOUTH THROUGH THE GREAT LAKES AREA LATER IN THE DAY. THIS FEATURE
MAY PROMPT A BACK DOOR COLD FRONT INTO THE AREA...WITH THE POTENTIAL
FOR SOME ISOLATED SHOWERS ALONG IT LATE IN THE AFTERNOON INTO SUNDAY
EVENING. AS THE BACK DOOR FRONT CONTINUES SOUTH THROUGH THE AREA
SUNDAY NIGHT...ANTICIPATE ISOLATED COVERAGE ACROSS
WESTERN...NORTHERN...AND EASTERN SECTIONS OF THE REGION. COVERAGE
MAY SCATTERED OVER SECTIONS OF SOUTHEAST WEST VIRGINIA.
THIS FRONT WILL BECOME STALLED OVER THE WESTERN THIRD OF THE AREA BY
MONDAY MORNING. DURING THE DAY MONDAY...AN AREA OF LOW PRESSURE WILL
BE MOVING EASTWARD THROUGH THE CENTRAL PART OF THE U.S. WIND FLOW
IN ADVANCE OF THIS FEATURE WILL TURN SOUTHERLY ACROSS THE WESTERN
GULF OF MEXICO...AND ADVECT INTO OUR REGION FROM THE SOUTHWEST. THE
RESULT WILL BE INCREASING COVERAGE OF SHOWERS ALONG THE STALLED
FRONT THANKS TO THE INCREASED MOISTURE. THE FRONT ITSELF WILL ALSO
TAKE ON MORE OF THE NATURE OF A WARM FRONT AND HEAD ACROSS THE AREA
BY MONDAY NIGHT.
ON TUESDAY...THE LOW WILL HEAD EASTWARD NEAR THE PA/MD LINE AND ITS
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE AREA. WE ARE
ANTICIPATING INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS DURING
THE DAY...ESPECIALLY ACROSS THE MOUNTAINS. AREAS ALONG AND EAST OF A
FARMVILLE TO DANVILLE LINE MAY NOT SEE ANY ACTIVITY UNTIL TUESDAY
EVENING. BY TUESDAY NIGHT... MOST OF THE PRECIPITATION WILL BE SOUTH
OF THE AREA IN ASSOCIATION WITH THE COLD FRONT. LINGERING SHOWERS
WILL STILL BE POSSIBLE ACROSS THE AREA...ESPECIALLY OVER SOUTHEAST
WV WHERE NORTHWEST FLOW UPSLOPE SHOWERS ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 330 PM EDT FRIDAY...
WITH THE COLD FRONT PASSING THROUGH OUR AREA ON TUESDAY NIGHT AND
WEDNESDAY MORNING...EXPECT ANOTHER LARGE DOME OF CANADIAN HIGH
PRESSURE TO BUILD INTO THE UPPER MIDWEST...BRINGING OUR TEMPERATURES
MUCH CLOSER TO NORMAL FOR THE FIRST WEEK OF APRIL. WITH HIGH
PRESSURE MAINTAINING ITS CONTROL THROUGH THE BEGINNING OF NEXT
WEEKEND...THE ONLY WEATHER CONCERNS WILL BE CHILLY OVERNIGHT
TEMPERATURES...WHICH MAY APPROACH FREEZING ACROSS PARTS OF SOUTHEAST
WEST VIRGINIA...AND MAY RESULT IN OVERNIGHT FROST ELSEWHERE ACROSS
THE MOUNTAINS.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 155 AM EDT SATURDAY...
MAINLY VFR WEATHER EXPECTED OVER THE ENTIRE BLACKSBURG TERMINAL
FORECAST AREA (KLWB...KBLF...KBCB...KROA...KLYH...KDAN) THROUGH
THE WEEKEND.
HOWEVER...APPROACH OF COOL FRONT AND ASSOCIATED SCATTERED SHOWERS
AND THUNDERSTORMS MAY SUPPORT SOME LOCALIZED MVFR FLIGHT
RESTRICTIONS TO BOTH CEILING AND VISIBILITY ALONG THE WESTERN
FLANKS OF THE APPALACHIANS THIS MORNING...MAINLY IN WEST
VIRGINIA.
PASSAGE OF COOL FRONT AND SURFACE RIDGE OF HIGH PRESSURE BUILDING
SOUTHEAST INTO THE MID APPALACHIAN AND MID ATLANTIC REGION THIS
AFTERNOON THROUGH SUNDAY SHOULD SUPPORT CLEARING CONDITIONS ACROSS
THE ENTIRE AREA.
THE NEXT THREAT FOR FLIGHT RESTRICTIONS WILL OCCUR LATE SUNDAY
NIGHT OR ON MONDAY...POSSIBLY CONTINUING INTO THE MID WEEK
PERIOD AS ANOTHER RIDGE OF HIGH PRESSURE BUILDS SOUTHWEST OUT OF
NEW ENGLAND. UPSLOPING WINDS ACROSS THE EASTERN FLANKS OF THE BLUE
RIDGE...WITH WEAK SHORT WAVES AND MOISTURE STREAMING NORTHEAST
OVER A STALLED FRONT OVER/NEAR THE AREA...MAY SET THE STAGE FOR
MVFR (AND POTENTIALLY LOWER) FLIGHT RESTRICTIONS INTO THE MID WEEK
PERIOD...ESPECIALLY OVER/IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WERT
NEAR TERM...WERT
SHORT TERM...DS
LONG TERM...NF
AVIATION...WERT
AREA FORECAST DISCUSSION
NWS SPOKANE WA
500 PM PDT Sun Apr 1 2012
.SYNOPSIS...
The widespread wet weather over the past several days will come to
an end tonight leading to a dry start of the work week. A Pacific
cold front will move through the area Tuesday night and Wednesday
for more rain and mountain snow. The remainder of the week will
see cool temperatures with afternoon and evening showers. Next
weekend should be dry and warmer.
&&
.DISCUSSION...
Tonight: Afternoon instability convective showers will quickly die
off this evening along with the winds. The HRRR model (which has
done a great job with the convective line between Coulee Dam and
Spokane) is suggesting the formation of a convective line that
will move across the Spokane/Cd`A metro area around 7pm this
evening. Not enough confidence to hit the forecast hard but the
HRRR suggests it would be a graupel shower.
Winds are gusting to 35 mph but should be diminishing quickly so
will cancel the wind advisory with the afternoon forecast package.
Another minor wave has moved onto the Oregon coast today. Models
show the remnants of this wave tracking across northern Oregon and
then into the southern Panhandle. Will keep pops in the Panhandle
higher south of I-90. Any precip that does fall would all be in
the form of snow as snow levels come crashing down to the valleys
overnight. Light accumulations are possible in the valleys
south/east of Pullman. RJ
Monday through Tuesday night...High pressure will build over the
region on Monday for a warming and drying trend. This will be
followed by another deep low pressure system moving into the
region Tuesday and Tuesday night.
Monday and Monday night the ridge axis will be over the Inland
Northwest Monday morning ans slide east through the day. The 12z
models were showing a weak wave moving through my southeast zones
overnight and early Monday morning, with the NAM being a bit
stronger with this feature. The 18z NAM is still showing the wave,
but not quite as robust. However with southwest flow and lingering
low level moisture some showers were kept in the forecast. For
the rest of Monday southerly winds will result in up-sloping flow into
the northern mountains. Some light showers will be possible, but
not widespread and only light accumulations are expected at best.
Otherwise the southerly flow will increase temperatures across the
region into the upper 40s to upper 50s. Winds will remain gusty
through the day, but less then Sunday.
Tuesday and Tuesday night the flow will back to almost southerly
as the upper level low currently moving through the Gulf of Alaska
moves off the west coast. Southerly flow with warm air advection
will increase into the 50s and 60s, which are 5 to 8 degrees
above normal. Moisture will increase along the Cascades through
the day as the southerly flow taps into deep atmospheric river.
PW`S are on the order of .50 to .60 which are 120-130 percent of
normal. With the upper level flow parallel to the front it will
take time for precipitation to cross the Cascade through the day
on Tuesday with little eastward movement expected until later in
the afternoon/evening when the following cold front moves through
the region. Snow levels start out above 4000 feet across the
northwest zones and over 5500 feet across the southeast Tuesday,
then drop below 2500 feet behind the cold front Tuesday night.
By this time, however, the heaviest precipitation should have
moved east in the warm sector. As such precipitation will be mainly
as rain with high elevation snow turning to snow with and behind
the front. Accumulations will only be a few to several inches near
the Cascade crest and less for the northern and eastern mountains.
/Tobin
Wednesday through Sunday: A longwave trough will settle into
the region on Wednesday and remain stationary over the Interior
West through much of the work-week courtesy of a blocking high,
downstream across the central US/Canada. In comparison to Tuesday,
temperatures will be on the downward trend with widely scattered
showers possible for any location, just about every day, through
Saturday; especially late afternoon coinciding with afternoon
heating. Models are in pretty good agreement regarding the
placement/timing of the mid-level trough but continue to struggle
resolving each shortwave circulating within. We have maintained the
highest PoPs across the Northeast Mountains of WA and N ID due to
breezy southwest flow initially however as each of these shortwaves
pivoting within the mean trough, become better resolved, we can
anticipate that each shortwave will organize larger clusters of
showers and moderate changes to PoPs are highly anticipated. The
upper-level trough will eventually fill and become replaced by
shortwave ridging as a second pacific wave or "kicker" approaches
the coast over the weekend. The evolution of this wave still
carries a lot of uncertainty but loose agreement indicates the
potential for seasonal temperatures and dry conditions to return
to close out the weekend into the start of the new week. /sb
&&
.AVIATION...
00z TAFS: Evening showers will be most numerous in the Panhandle
and extreme eastern WA. Gusty winds will start to diminish after
sunset. Any lowering of cigs at TAF sites due to -shrasn will be
brief. Look for IFR cigs to develop overnight at KGEG/KSFF/KCOE
tonight but these should lift by mid- morning on Monday. EK
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 31 52 39 62 39 45 / 20 10 0 10 60 60
Coeur d`Alene 31 49 36 61 38 44 / 30 10 0 10 70 70
Pullman 31 52 37 63 35 42 / 20 0 0 0 70 60
Lewiston 34 59 42 67 39 48 / 10 0 0 0 60 60
Colville 31 50 37 63 37 50 / 20 20 10 20 70 60
Sandpoint 30 47 35 60 38 44 / 40 10 10 10 70 70
Kellogg 31 45 33 59 36 41 / 40 20 10 10 80 90
Moses Lake 33 57 43 62 39 56 / 10 10 10 20 60 20
Wenatchee 36 56 43 56 35 54 / 10 10 10 40 40 20
Omak 31 54 40 58 35 53 / 10 10 10 60 50 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
925 PM CDT SUN APR 1 2012
.UPDATE...
SURFACE FRONT CURRENTLY FROM NEAR IND TO DSM...AND ACTUALLY
SAGGING SOUTH THE LAST FEW HOURS. SO IT APPEARS WE ARE DOOMED TO
STAY IN COOLER AIR PROBABLY THROUGH THE DURATION. HAVE ADJUSTED
HOURLY TEMPERATURES DOWN TONIGHT AND THROUGH TOMORROW ALONG WITH
HIGH TEMPERATURES. DROPPED THEM ABOUT 3 MORE DEGREES ESPECIALLY
AREAS TO THE SOUTH AND WEST WHERE WE HAVE BEEN CONSISTENTLY TOO
WARM LAST COUPLE OF DAYS. LATEST GUIDANCE HAS A PRETTY SOLID DECK
OF WARM ADVECTION CLOUDS AROUND 4K FORMING DURING THE DAY AND WITH
EAST WINDS OFF THE LAKE...TEMPERATURES SHOULD BE SIMILAR TO TODAY.
MEANWHILE...A COUPLE OF BANDS OF SHOWERS HAVE BEEN PERSISTENT FROM
NORTH CENTRAL WISCONSIN INTO SOUTHWEST LOWER MICHIGAN. LOTS OF DRY
AIR IN THE SOUNDINGS BELOW 600 MB. BUT 00Z UPPER AIR DATA SHOWS
STRONG BAROCLINIC ZONE ON ANTICYCLONIC SIDE OF 250 MB 120 KNOT
JET. RATHER MOIST IN 700-500 MB LAYER AND STRONG WARM ADVECTION
SHOWN AT 700 MB ACROSS WISCONSIN. DECENT FRONTOGENESIS IN THE
850-500 MB LAYER AS WELL...THUS THE BANDED PRECIPITATION.
HAS RECENTLY MEASURED 0.03" AT KEGV AND 0.01" AT KSVE IN THE
NORTHERN BAND...AND THIS IS HANDLED WELL BY LAST FEW RUNS OF HRRR.
EVEN A REPORT OF LTGIC NEAR RHI WITH THIS ACTIVITY...WHICH HAS UP
TO 40 DBZ PER KGRB RADAR.
GIVEN THE HRRR BRUSHING THE AREA FROM GREEN LAKE TO OZAUKEE COUNTY
ON NORTH...HAVE ADDED SCATTERED LIGHT SHOWERS AFTER MIDNIGHT IN
THAT AREA...FOLLOWING THE TIMING OF THE HRRR. RUC SOUNDINGS DO
SHOW 50-100 J/KG OF CAPE AT KOSH DURING THE NIGHT...BUT SINCE WE
ARE WORRIED ABOUT IT MEASURING NOT GOING TO GO OVERBOARD AND ADD
THUNDER.
&&
.AVIATION/06Z TAFS/...
PESKY MVFR DECK HAS FINALLY PUSHED SOUTH AND DISSIPATED. ASIDE
FROM MIDDLE DECK AND LIGHT SHOWERS STAYING NORTH AND EAST OF TAF
SITES...SHOULD BE QUIET MUCH OF THE NIGHT.
COLD FRONT THAT SAGGED BACK SOUTH SHOULD STALL AND THEN RETURN
NORTH AS A WARM FRONT INTO CENTRAL PARTS OF IOWA AND ILLINOIS
MONDAY AND MONDAY EVENING AS A LOW PRESSURE AREA TRACKS TOWARD
NORTHERN ILLINOIS. WARM MOIST AIR RETURNING JUST ABOVE THIS FRONT
WILL RESULT IN VFR CLOUD DECK DURING THE LATE MORNING OR AFTERNOON
HOURS CONTINUING INTO MONDAY NIGHT.
ELEVATED INSTABILITY ABOVE THE FRONT WILL EVENTUALLY LEAD TO
THUNDERSTORMS FORMING OVER CENTRAL OR SOUTHERN WISCONSIN. SOME
UNCERTAINTY AS TO WHETHER THESE WILL REMAIN NORTH OF THE TAF SITES
BUT NOTHING SHOULD HAPPEN BEFORE 00Z TUESDAY.
&&
.PREV DISCUSSION... /ISSUED 332 PM CDT SUN APR 1 2012/
VERY SHORT TERM...TONIGHT AND MONDAY.
ANOTHER LOW STRATUS DECK IS SLOWLY MIXING OUT ACROSS THE FORECAST
AREA THIS AFTERNOON. THERE ARE BREAKS DEVELOPING IN THE SOUTHERN
COUNTIES WHERE THE DECK REMAINS...AND WITH A FEW MORE HOURS OF
SUN...SHOULD SEE MOST OF NOT ALL OF IT MIX OUT. CONFIDENCE IS
SHAKY...AS IF IT DOES NOT MIX OUT BEFORE SUNSET...IT LIKELY WILL
LINGER THROUGH TONIGHT AND INTO MONDAY. THE BEST CHANCES OF THIS
HAPPENING WOULD BE IN THE FAR SOUTHERN COUNTIES. THIS DECK SHOWN BY
HIGH RESOLUTION RAPID REFRESH MODEL TO DEVELOP AGAIN LATER THIS
EVENING AND OVERNIGHT IN EASTERN IOWA TO NORTHERN ILLINOIS...CLOSE
TO THE AREA. WILL HAVE TO BE WATCHED CLOSELY.
FOR NOW...WENT WITH A MIX OUT OF THE LOW STRATUS BY 00Z
MONDAY...THEN KEPT PARTLY CLOUDY IN FOR TONIGHT WITH SOME MID LEVEL
CLOUDS SLIDING SOUTHEAST THROUGH THE REGION. LOWS IN THE LOWER TO
MID 40S EAST TO WEST SEEM REASONABLE...THOUGH MAY BE HIGHER IF LOW
CLOUDS LINGER IN THE FAR SOUTH.
REMOVED POPS MONDAY AFTERNOON...AS SLOWER PROGRESSION WITH NEXT
SYSTEM KEEPS MAIN UPWARD VERTICAL MOTION NORTHWEST OF THE AREA. THIS
IN SPITE OF SOME DECENT ELEVATED CAPES OF 500 TO 1000 J/KG BY LATE
AFTERNOON. PARTLY SUNNY SKIES WITH ONSHORE WINDS SHOULD BRING COOL
TEMPERATURES NEAR THE LAKE...WITH MILD 60S INLAND. AGAIN...THIS
ASSUMING THE LOW STRATUS DOES NOT LINGER.
SHORT TERM...MONDAY NIGHT THROUGH WEDNESDAY.
SHORT TERM GUIDANCE IN REASONABLE AGREEMENT ON CARRYING WEAK LOW
PRESSURE AND MID LEVEL TROUGH ACROSS FAR SOUTHERN WI/NORTHERN IL
REGION LATER MON NIGHT INTO TUE MRNG. TREND HAS BEEN FOR MOST
GUIDANCE TO SLOW DOWN TROUGH PASSAGE...WHILE NAM MORE OF AN OUTLIER
WITH MORE PROGRESSIVE FLOW...CONTROLLED BY STRONGER AND FARTHER EAST
UPPER LEVEL JET. WL LEAN TOWARD SLOWER CAMP...WHICH MEANS WILL NEED
TO HANG ONTO POPS FOR A GREATER TIME ON TUESDAY. BEST CHANCE FOR
PRECIP ON TUE WILL BE IN THE SOUTH...CLOSER TO SFC FRONTAL BOUNDARY
AND INSTABILITY AXIS. BULK OF AFTN CONVECTION HOWEVER SHOULD BE
SOUTH OF IL BORDER.
FOR MON NGT...WL HANG ONTO HIGHER CHANCE POPS. STILL LOOKING AT LOW
LAYER Q-VECTOR CONVERGENCE AXIS PASSING ACROSS SRN WI DURING THE
NIGHT...BUT DELAYED A BIT DUE TO SLOWER TROF PASSAGE. STRONGEST
ALSO LAYER FN VECTOR RESPONSE TO FRONTOGENESIS SAGS THROUGH SRN WI
LATE IN THE NIGHT INTO TUE MRNG. HOWEVER SOME CONCERN OVER LACK OF
COLUMN MOISTENING DURING THE NIGHT WITH COLUMN ABV 5K FEET FAILING
TO SATURATE. ALSO LACK OF MID-LEVEL TRIGGER SO NOT ENOUGH TO
CONVINCE ME TO BUMP UP POPS ABV CHANCE.
INCREASING NLY WINDS WL PULL DRIER AIR ACROSS CWA LATER TUE AND TUE
NIGHT WITH RIDGE BUILDING IN FOR WED. PERSISTENT ONSHORE FLOW WL
KEEP THE EAST NOTICEABLY COOLER.
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY.
DESPITE UNCERTAINTY REGARDING AMPLITUDE AND AMOUNT OF LONG WAVE
TROFFING BOTH UPSTREAM OVER WRN CONUS...AND ALSO WELL DOWNSTREAM IN
ERN CANADA AND THE NORTHERN ATLANTIC...ALL EXTENDED GUIDANCE IN
REASONABLE AGREEMENT ON HIGH PRESSURE RIDGE BOTH AT THE SURFACE AND
ALOFT BETWEEN TWO TROUGHS...REMAINING NEARLY STATIONARY OVER THE
UPPER MIDWEST AND WESTERN GTLAKES THROUGH THE END OF THE WORK WEEK.
THIS WILL RESULT IN A PERSISTENT NORTHEAST FLOW WITH COOLER
TEMPERATURES BY LAKE MICHIGAN. HOWEVER TEMPERATURES SHOULD STILL
AVERAGE ABOVE NORMAL FOR EARLY APRIL. PENDING CLOUD COVER AND
BOUNDARY LAYER WINDS...PATCHY LATE NIGHT FROST WILL BE A
THREAT...ESPECIALLY THU NIGHT.
EXTENDED GUIDANCE IN AGREEMENT ON BUILDING RIDGE OVER THE UPPER
MIDWEST PREVENTING CUTOFF UPPER LOW FROM TAKING MORE NORTHEAST
TRACK. HENCE EXPECT CUTOFF TO TAKE MORE ELY TRACK FROM THE CENTRAL
PLAINS THROUGH THE CENTRAL MS VLY REGION ON WED AND THU...EVENTUALLY
GETTING ABSORBED BY LONG WAVE TROF OVER ERN CONUS...AND ANY
PRECIPITATION ASSOCIATED WITH THIS SYSTEM REMAINING SOUTH OF WI.
NO SURPRISE...5 DAY MEAN 5H HEIGHTS BASED ON GFS REMAIN ABOVE NORMAL
THROUGH THIS WEEK OVER THE UPPER MIDWEST...MAINLY DUE TO PERSISTENT
MID-LEVEL RIDGING.
TREND IN LONG RANGE GUIDANCE HAS BEEN BLOCKING RIDGING OVER UPPER
MIDWEST LINGERING INTO SATURDAY...SLOWING DOWN APPROACHING TROUGH
FROM THE PLAINS UNTIL SAT NIGHT OR SUNDAY. APPEARS GULF WILL BE
INITIALLY CUTOFF AS WELL...PREVENTING DEEPER MOISTURE FROM SURGING
NWD. FOR NOW...WL CONTINUE TO CONFINE SAT POPS TO WEST...AND CARRY
LOW POPS SAT NIGHT.
AVIATION /00Z TAFS/...
CEILINGS WITH LOW STRATUS DECK HAVE CONTINUED
TO RISE INTO THE MVFR RANGE THIS AFTERNOON AT TAF SITES. SHOULD MAY
SEE THESE CEILINGS MIX OUT BY 00Z MONDAY AT TAF SITES...BUT
CONFIDENCE IS SHAKY IN THIS HAPPENING. IF THEY DO NOT MIX OUT BEFORE
SUNSET...THEY WILL LINGER TONIGHT AND PERHAPS INTO MONDAY. WILL HAVE
TO WATCH THEM CLOSELY TONIGHT.
SHOULD SEE SOME SCATTERED TO BROKEN 3500 TO 4000 FOOT CLOUDS AFTER
10Z MONDAY AND LINGER THROUGH MONDAY. APPROACH OF LOW PRESSURE TO
THE SOUTHWEST OF THE AREA SHOULD BRING AN INCREASE IN EAST WINDS
MONDAY...WITH GUSTS TO AROUND 20 KNOTS POSSIBLE. WILL NOT MENTION
PRECIPITATION THROUGH 00Z TUESDAY...WITH BEST UPWARD MOTION ARRIVING
IN THE AREA AFTERWARDS.
MARINE...
WINDS AND WAVES WILL APPROACH SMALL CRAFT ADVISORY LEVELS
MONDAY...AS THE PRESSURE GRADIENT TIGHTENS WITH THE APPROACH OF THE
LOW PRESSURE SYSTEM. DID NOT GO WITH A SMALL CRAFT ADVISORY AT THIS
TIME...DUE TO BORDERLINE CONFIDENCE IN THE WINDS AND WAVES MEETING
CRITERIA.
CONFIDENCE...
TONIGHT AND MONDAY...LOW TO MEDIUM.
MONDAY NIGHT THROUGH TUESDAY...LOW TO MEDIUM.
TUESDAY NIGHT THROUGH SATURDAY...HIGH.
SATURDAY NIGHT AND SUNDAY...MEDIUM.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...CRAVEN
TONIGHT/MONDAY AND AVIATION/MARINE...WOOD
MONDAY NIGHT THROUGH SUNDAY...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1236 PM CDT SAT MAR 31 2012
.SHORT TERM...THIS AFTERNOON
1131 AM CDT SAT MAR 31 2012
THE LATEST RUC AND NAM/WRF CONTINUE TO SUGGEST THAT THE LOW CLOUDS
WILL LINGER INTO TONIGHT. AS A RESULT THINKING THAT OUR HIGH
TEMPERATURE FORECAST IS WAY TOO GENEROUS. YESTERDAY UNDERNEATH
THESE CLOUDS TEMPERATURES STRUGGLED TO CLIMB INTO THE MID AND
UPPER 40S ACROSS WISCONSIN. EVEN IN SOUTHEAST MINNESOTA AND
NORTHEAST IOWA...THEY WERE ONLY ABLE TO CLIMB INTO THE MID 50S AND
THAT WAS DUE TO A BRIEF PERIOD OF PARTIAL SUNSHINE. THE LATEST RUC
IS ONLY SUGGESTING HIGHS IN THE 40S THIS AFTERNOON WHICH SEEMS
RATHER REASONABLE. SINCE THIS WOULD BE A CONSIDERABLE DROP IN OUR
FORECAST HIGH TEMPERATURES...DECIDED TO TAKE OUR EXISTING MAXIMUM
TEMPERATURE GRID AND BLEND IT WITH THE LATEST RUC. MOST LIKELY
STILL TOO WARM...BUT AT LEAST IT IS IN THE RIGHT DIRECTION.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
315 AM CDT SAT MAR 31 2012
QUIET WEATHER LOOKS TO DOMINATE THE ENTIRE LONG TERM PERIOD. A
CANADIAN HIGH PRESSURE RIDGE IS PROGGED BY THE 31.00Z
ECMWF/GFS/CANADIAN/UKMET TO BUILD INTO THE FORECAST AREA
TUESDAY...BEHIND MONDAY NIGHTS COLD FRONT...THEN ONLY DRIFT OFF TO
THE EAST THROUGH FRIDAY NIGHT. MEANWHILE...UPPER RIDGING LOOKS TO
BUILD ALOFT AHEAD OF DEEP TROUGHING DEVELOPING OVER THE WESTERN U.S.
THROUGH THE LONG TERM PERIOD. THIS SETUP FAVORS DRY CONDITIONS.
NOTE...THE 31.00Z GFS TRIES TO BRING THE CUT-OFF UPPER LOW IN NEW
MEXICO MONDAY NIGHT INTO IOWA BY 12Z THURSDAY...RESULTING IN SOME
SHOWERS OVER THE FORECAST AREA. THIS MODEL IS AN OUTLIER...EVEN
COMPARED TO ITS PREVIOUS RUN AND MOST OF ITS ENSEMBLE MEMBERS...AND
THEREFORE IGNORED AT THIS TIME. 850MB TEMPS WILL SLOWLY COOL...
DROPPING TO 2-4C FOR BOTH WEDNESDAY AND THURSDAY...BEFORE CLIMBING
BACK UP TO 4-6C ON FRIDAY AS THE SURFACE RIDGE MOVES EAST.
STILL...PLENTY OF SUN IS EXPECTED WHICH SHOULD HELP KEEP HIGHS ABOVE
NORMAL. CERTAINLY POSSIBLE TO SEE SOME FROST AT TIMES...ESPECIALLY
OVER CENTRAL WISCONSIN. IN ADDITION...MAY HAVE TO KEEP AN EYE ON
RELATIVE HUMIDITIES GIVEN WHAT LOOKS TO BE A BRIEF HUDSON BAY HIGH
SCENARIO...KNOWN TO MIX DEWPOINTS LOWER THAN FORECAST. HOWEVER...
WITH GREEN-UP WELL UNDERWAY...EVAPOTRANSPIRATION COULD KEEP
DEWPOINTS HIGHER MORE THAN WHAT WOULD NORMALLY OCCUR WITH A HUDSON
BAY HIGH.
&&
.AVIATION...THROUGH 18Z SUNDAY
1235 PM CDT SAT MAR 31 2012
EXTENSIVE IFR/MVFR CEILINGS PERSIST ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY AND GREAT LAKES EARLY THIS AFTERNOON. THE RUC
SUGGESTS THAT THESE CEILINGS WILL SLOWLY RISE INTO THE 1500 TO
2500 FOOT RANGE BY MID TO LATE AFTERNOON. THE NAM/WRF THEN
SUGGESTS THAT THESE CLOUDS WILL LIKELY LOWER AND BECOME LIFR/IFR
AFTER 01.06Z AND REMAIN THERE THROUGH AT LEAST 01.15Z. THE MODELS
THEN SUGGEST THAT THE CLOUDS MAY SCATTER OUT. HOWEVER WITH THE
925 MB OFF OF LAKE MICHIGAN...THERE IS SOME CONCERN THAT THESE
CLOUDS WILL LINGER MUCH LONGER THAN WHAT THE MODELS INDICATE...
THEREFORE...WENT MORE PESSIMISTIC WITHE CLOUD FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 AM CDT SAT MAR 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1201 PM CDT SAT MAR 31 2012
.UPDATE...LOW CLOUD DECK CONTINUES TO HOLD STRONG ACROSS THE
REGION THIS MORNING. AREA RUC FORECAST SOUNDINGS AND TAMDAR
SOUNDINGS SHOWING THIS DECK TO BE ABOUT 1000 TO 2000 FEET THICK.
RUC/NAM SOUNDINGS AND HIGH RESOLUTION RAPID REFRESH MODEL SHOW
THIS LOW DECK SLOWLY MIXING OUT THIS AFTERNOON. HOWEVER...MID TO
HIGH CLOUDS ASSOCIATED WITH WARM AIR ADVECTION WILL CONTINUE TO
STREAM SOUTHEAST THROUGH THE REGION THROUGH THE AFTERNOON AND
EVENING.
THUS...HAVE GONE WITH MOSTLY CLOUDY WORDING THROUGH THIS
AFTERNOON...AND LIKELY THROUGH THE EVENING AS WELL. HAVE LOWERED
HIGH TEMPERATURES THIS AFTERNOON INTO THE MID TO UPPER 40S IN MOST
AREAS AS A RESULT OF THE CLOUDS. THIS MAY BE TOO WARM IN SOME
AREAS AND FURTHER ADJUSTMENTS DOWNWARD MAY BE NECESSARY.
12Z NAM/GFS MODELS SHOWING BULK OF POSSIBLE ELEVATED CONVECTION
LATER TONIGHT INTO SUNDAY MORNING STAYING JUST SOUTH OF THE AREA.
STILL HAVE 25 TO 30 KNOT WEST SOUTHWESTERLY LOW LEVEL JET POINTING
TOWARD THE AREA BY 06Z SUNDAY...THEN VEERS DUE WEST LATER TONIGHT.
NOT A LOT OF MOISTURE ADVECTION INTO THE REGION WITH THIS
FEATURE...BUT AREA FORECAST SOUNDINGS DO SHOW 500 TO 1000 J/KG
ELEVATED CAPE WITH DECENT EFFECTIVE LAYER SHEAR. LOW WET BULB ZERO
HEIGHTS SUGGEST SMALL HAIL IS POSSIBLE WITH ANY STORMS THAT DO
FORM AND MAKE IT INTO THE AREA.
HIGHEST POPS TONIGHT INTO SUNDAY MORNING LIKELY TO BE IN THE FAR
SOUTHERN COUNTIES...TAPERING DOWN TO THE NORTH. TEMPERATURES
LIKELY TO REMAIN NEARLY STEADY OR SLOWLY RISE WITH WARM AIR
ADVECTION CONTINUING. LIGHT WINDS AND LINGERING LOW LEVEL MOISTURE
SHOULD ALLOW FOR FOG DEVELOPMENT LATER TONIGHT/EARLY SUNDAY AS
WELL. DENSE FOG NOT EXPECTED WITH SOME HIGH CLOUDS LINGERING.
&&
.AVIATION/18Z TAFS/...MVFR/IFR CEILINGS ARE EXPECTED TO LINGER
INTO MID AFTERNOON ACROSS TAF SITES...BEFORE SLOWLY MIXING OUT
LATER THIS AFTERNOON. MVFR VISIBILITIES AT MADISON SHOULD ALSO
BECOME VFR DURING THIS TIME. VFR CEILINGS WITH MID TO HIGH CLOUDS
THEN EXPECTED THROUGH THIS EVENING...BEFORE SOME BREAKS OCCUR
LATER TONIGHT AND SUNDAY.
BEST CHANCES FOR ANY SHOWERS OR STORMS WOULD BE BETWEEN 06Z AND
12Z SUNDAY...BUT BEST CHANCES REMAIN SOUTH OF THE AREA...SO WILL
NOT MENTION IN TAFS AT THIS TIME.
LIGHT WINDS BETWEEN 09Z AND 14Z SUNDAY...WITH LINGERING LOW LEVEL
MOISTURE...MAY ALLOW FOR IFR/LIFR FOG FORMATION. SOME HIGH CLOUDS
LINGERING SHOULD PREVENT WIDESPREAD DENSE FOG. VFR CONDITIONS THEN
EXPECTED THROUGH THE REST OF SUNDAY. WINDS SHOULD BECOME EAST
NORTHEAST ON SUNDAY...AS WARM FRONT STAYS SOUTH OF THE AREA.
&&
.PREV DISCUSSION... /ISSUED 330 AM CDT SAT MAR 31 2012/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM.
LOW STRATUS AND PATCHY DRIZZLE WILL LINGER INTO THIS MORNING...GIVEN
AREA FORECAST SOUNDINGS SHOWING THE MOIST LAYER TRAPPED UNDER AN
INVERSION AROUND 2 THSD FT. NAM FORECAST SOUNDINGS SHOW SOME MIXING
DURING THE EARLY AFTERNOON ACROSS THE FORECAST AREA.
A WEAK SHORTWAVE WILL BE EXITING NORTHERN ILLINOIS AROUND 12Z/7AM.
A FEW SHOWERS FROM THIS SHOULD STAY JUST SOUTH OF THE ILLINOIS
BORDER.
850/700MB WARM AIR ADVECTION BEGINS TODAY WITH FORECAST SOUNDINGS
SHOWING SOME ELEVATED CAPE AROUND 190 J/KG LIFTED FROM AROUND
5 THSD FT. NO REAL SOURCE OF LIFT. 850 MB WINDS INCREASE EARLY
THIS EVENING AS A SHORTWAVE MOVES ACROSS NORTHERN LAKE SUPERIOR.
ELEVATED CAPE REACHES 1000 J/KG MAINLY LATE TONIGHT LIFTED FROM
AROUND 3 THSD FT. 850 MB DEWPOINTS INCREASE TO AROUND 10 CELSIUS
OVER THE SOUTHERN PORTIONS OF THE FORECAST AREA WITH SOME 850 MB
CONVERGENCE AROUND MIDNIGHT. 850 MB LIFTED INDEX VALUES REACH -3.5
CELSIUS. SURFACE WARM FRONT PUSHES NORTH INTO FAR NORTHERN
ILLINOIS. THIS WILL RESULT IN A CHANCE OF THUNDERSTORMS...
ESPECIALLY ACROSS SOUTHERN SECTIONS. WET BULB ZERO VALUES JUST
UNDER 8 THSD FT SO SOME SMALL HAIL WOULD BE POSSIBLE.
EXPECT HIGHS IN THE MID 40S NEAR LAKE MICHIGAN...BUT TEMPERATURES
MAY REACH NEAR 60 WEST OF MADISON.
SUNDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
THUNDERSTORM CHANCES CONTINUE ACROSS SOUTHERN WI SUN MORNING WITH
MODELS IN STRONG AGREEMENT OF A COMPACT SYSTEM ROLLING ACROSS THE
WI/IL BORDER. ECMWF/CANADIAN A LITTLE FURTHER SOUTH THAN THE
NAM/GFS SOLUTIONS.
00Z ECMWF HAS NOW TAKEN ON THE COOLER LOOK OF THE GFS ON SUN AND
MON...WITH 925MB TEMPS RANGING FROM AROUND 12C NEAR THE SHORE AND
18C IN SOUTH CENTRAL WI. NAM IS WARMER AND AGREED MORE WITH THE
12Z ECMWF. WENT WITH CONSENSUS OF TEMPS FOR MAX T ON SUN AND MON.
TIGHT TEMP GRADIENT BETWEEN LOW 60S ALONG THE LAKESHORE AND UPPER
70S IN SW FORECAST AREA.
THERE IS PLENTY OF UNCERTAINTY ABOUT WHETHER OR NOT CONVECTION COULD
BREAK OUT SUN NIGHT. THE 850MB BAROCLINIC ZONE SHOULD PROBABLY BE
NORTH OF THE FORECAST AREA/CWA/...WITH THE 925MB ZONE LAGGING
SLIGHTLY BEHIND IN OUR CWA. NOSE OF LOW LEVEL JET IS MORE UNCERTAIN.
FEEL THAT BETTER CHANCE FOR ELEVATED CONVECTION SHOULD BE IN
NORTHEAST CWA SO ADDED SLIGHT CHANCE. STEEP MID LEVEL LAPSE RATES
ALLOW FOR DECENT CAPE AROUND 800 J/KG. SHEAR IS WEAK IN THE MID
LEVELS.
THE CONVECTION POSSIBILITY CONTINUES INTO MONDAY BUT THERE IS
STILL UNCERTAINTY IN THE BAROCLINIC ZONE LOCATION AND LACK OF A
TRIGGER TO BEAT THE CAPPED ENVIRONMENT. DUE TO THE STRONG CAP PER
FCST SNDGS...CONVECTION WOULD HAVE TO BE ELEVATED AND HAVE
DEVELOPED UPSTREAM. SLIGHT CHANCE OF TSTORMS FOR MON.
BACKED OFF ON THE TSTORM CHANCES MON NIGHT AS MODELS HAVE SLOWED
DOWN THE TIMING OF THE COLD FRONT UNTIL LATE MON NIGHT/TUE
MORNING...ESPECIALLY THE ECMWF. THE NAM AND GFS ARE PERSISTENT IN
KEEPING THE 925MB BAROCLINIC ZONE ACROSS SOUTHERN WI MON AND MON
NIGHT WHILE THE ECMWF MOVES IT INTO CENTRAL WI.
LONG TERM...
TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
CONSENSUS OF MODELS SHOW MOST OF PRECIP EXITING SOUTHEAST WI TUE
MORNING. HOWEVER WITH THE LATEST 00Z ECMWF SLOWING DOWN THE
SYSTEM...POPS MAY HAVE TO BE INCREASED SLIGHTLY. ALSO ONLY MENTIONED
SHOWERS...BUT THUNDERSTORMS JUST AHEAD OF THE FRONT WILL BE
POSSIBLE.
TEMPS WILL BE COOLER ON TUE WITH HIGHS IN THE 50S TO LOWER 60S WITH
925MB TEMPS DROPPING BACK TO AROUND 5C. HIGH PRESSURE SINKING DOWN
INTO THE UPPER GREAT LAKES REGION WILL KEEP PRECIP CHANCES TO OUR
SOUTH AND TEMPS MILD IN THE 50S AND 60S THROUGH THE END OF THE WEEK.
A PERSISTENT EASTERLY COMPONENT OF THE WINDS OFF OF LAKE MICHIGAN
WILL KEEP TEMPS COOLER NEAR THE LAKESHORE.
AVIATION/12Z TAFS/...
EXPECT MAINLY IFR CEILINGS...WITH SOME LIFR EARLY THIS MORNING. THE
IFR CIGS WILL PERSIST THROUGH MUCH OF THE MORNING.
WINDS VEER SOUTHEAST ON SATURDAY AS THE SURFACE HIGH MOVES INTO
LOWER MICHIGAN THIS AFTERNOON. THE IFR CLOUD DECK SHOULD GRADUALLY
MIX OUT THIS AFTERNOON...MAYBE LATE MORNING OVER PORTIONS OF SOUTH
CENTRAL WISCONSIN. MAINLY VFR CONDITIONS EXPECTED LATER THIS
AFTERNOON.
A SURFACE WARM FRONT PUSHES NORTH INTO FAR NORTHERN ILLINOIS. THIS
WILL RESULT IN A CHANCE OF THUNDERSTORMS...ESPECIALLY ACROSS
SOUTHERN SECTIONS. SOME SMALL HAIL WILL BE POSSIBLE.
MAINLY VFR CEILINGS ALTHOUGH SOME IFR FOG WILL BE POSSIBLE.
MARINE...
EAST WINDS WILL GRADUALLY BECOME SOUTHEAST...AND WILL REMAIN BELOW
SMALL CRAFT CRITERIA. SOME FOG WILL BE POSSIBLE...ESPECIALLY
TONIGHT AS A WARM FRONT APPROACHES FROM NORTHERN ILLINOIS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1131 AM CDT SAT MAR 31 2012
.SHORT TERM...THIS AFTERNOON
1131 AM CDT SAT MAR 31 2012
THE LATEST RUC AND NAM/WRF CONTINUE TO SUGGEST THAT THE LOW CLOUDS
WILL LINGER INTO TONIGHT. AS A RESULT THINKING THAT OUR HIGH
TEMPERATURE FORECAST IS WAY TOO GENEROUS. YESTERDAY UNDERNEATH
THESE CLOUDS TEMPERATURES STRUGGLED TO CLIMB INTO THE MID AND
UPPER 40S ACROSS WISCONSIN. EVEN IN SOUTHEAST MINNESOTA AND
NORTHEAST IOWA...THEY WERE ONLY ABLE TO CLIMB INTO THE MID 50S AND
THAT WAS DUE TO A BRIEF PERIOD OF PARTIAL SUNSHINE. THE LATEST RUC
IS ONLY SUGGESTING HIGHS IN THE 40S THIS AFTERNOON WHICH SEEMS
RATHER REASONABLE. SINCE THIS WOULD BE A CONSIDERABLE DROP IN OUR
FORECAST HIGH TEMPERATURES...DECIDED TO TAKE OUR EXISTING MAXIMUM
TEMPERATURE GRID AND BLEND IT WITH THE LATEST RUC. MOST LIKELY
STILL TOO WARM...BUT AT LEAST IT IS IN THE RIGHT DIRECTION.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
315 AM CDT SAT MAR 31 2012
QUIET WEATHER LOOKS TO DOMINATE THE ENTIRE LONG TERM PERIOD. A
CANADIAN HIGH PRESSURE RIDGE IS PROGGED BY THE 31.00Z
ECMWF/GFS/CANADIAN/UKMET TO BUILD INTO THE FORECAST AREA
TUESDAY...BEHIND MONDAY NIGHTS COLD FRONT...THEN ONLY DRIFT OFF TO
THE EAST THROUGH FRIDAY NIGHT. MEANWHILE...UPPER RIDGING LOOKS TO
BUILD ALOFT AHEAD OF DEEP TROUGHING DEVELOPING OVER THE WESTERN U.S.
THROUGH THE LONG TERM PERIOD. THIS SETUP FAVORS DRY CONDITIONS.
NOTE...THE 31.00Z GFS TRIES TO BRING THE CUT-OFF UPPER LOW IN NEW
MEXICO MONDAY NIGHT INTO IOWA BY 12Z THURSDAY...RESULTING IN SOME
SHOWERS OVER THE FORECAST AREA. THIS MODEL IS AN OUTLIER...EVEN
COMPARED TO ITS PREVIOUS RUN AND MOST OF ITS ENSEMBLE MEMBERS...AND
THEREFORE IGNORED AT THIS TIME. 850MB TEMPS WILL SLOWLY COOL...
DROPPING TO 2-4C FOR BOTH WEDNESDAY AND THURSDAY...BEFORE CLIMBING
BACK UP TO 4-6C ON FRIDAY AS THE SURFACE RIDGE MOVES EAST.
STILL...PLENTY OF SUN IS EXPECTED WHICH SHOULD HELP KEEP HIGHS ABOVE
NORMAL. CERTAINLY POSSIBLE TO SEE SOME FROST AT TIMES...ESPECIALLY
OVER CENTRAL WISCONSIN. IN ADDITION...MAY HAVE TO KEEP AN EYE ON
RELATIVE HUMIDITIES GIVEN WHAT LOOKS TO BE A BRIEF HUDSON BAY HIGH
SCENARIO...KNOWN TO MIX DEWPOINTS LOWER THAN FORECAST. HOWEVER...
WITH GREEN-UP WELL UNDERWAY...EVAPOTRANSPIRATION COULD KEEP
DEWPOINTS HIGHER MORE THAN WHAT WOULD NORMALLY OCCUR WITH A HUDSON
BAY HIGH.
&&
.AVIATION...TODAY AND TONIGHT
605 AM CDT SAT MAR 31 2012
LOW STRATUS WILL PERIST AT THE TAF SITES THROUGH MID MORNING
PRODUCING CEILINGS IN THE 200 TO 700 FT RANGE AT KRST...AND IN THE
800 TO 1100 FT RANGE AT KLSE. IN ADDITION...VISIBLITIES WILL BE
REDUCED INTO THE 2 TO 3 SM RANGE AT KRST THROUGH 14Z. LOOK FOR
CONDITIONS TO GRADUALLY IMPROVE TO MVFR IN THE 14 TO 16 Z
TIMEFRAME AS THE STRATUS STARTS TO BREAK UP. CLOUD BASES WILL RISE
TO AROUND 1500 FT LATE THIS MORNING...BECOMING SCATTERED BY EARLY
THIS AFTERNOON. PLAN ON SOUTHEAST WINDS OF 6 TO 10 KTS THROUGH THE
DAY. A WARM FRONT WILL LIFT INTO NORTHERN IOWA AND SOUTHWEST
WISCONSIN THIS EVENING AND WILL BE THE FOCUS FOR SHOWER AND
THUNDERSTORM DEVELOPMENT. THE STRONGEST 850 MB MOISTURE TRANSPORT
WILL OCCUR ACROSS NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THE
SHOWERS AND THUNDERSTORMS SHOULD STAY SOUTH OF THE TAF SITES LATE
THIS EVENING INTO THE OVERNIGHT HOURS WITH VFR CONDITIONS
EXPECTED. WILL HAVE TO KEEP A CLOSE WATCH ON THE PROGRESSION OF
THE WARM FROM LATE THIS AFTERNOON INTO EARLY THIS EVENING. IF
THUNDERSTORMS DEVELOP...A FEW STORMS WILL BE CAPABLE OF PRODUCING
LARGE HAIL AND BRIEF HEAVY RAINFALL. LATEST GUIDANCE IS SUGGESTING
FOG DEVELOPMENT LATE TONIGHT INTO EARLY SUNDAY MORNING...MAINLY
ALONG AND NORTH OF THE WARM FRONT. CURRENT THINKING IS THAT THE
WINDS NEAR THE SURFACE WILL PROVIDE ENOUGH MIXING TO INHIBIT FOG
DEVELOPMENT. IF THE WARM FRONT ADVANCES FURTHER NORTH LATE
TONIGHT...AND DECOUPLING OCCURS...FOG COULD IMPACT THE TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 AM CDT SAT MAR 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
605 AM CDT SAT MAR 31 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
315 AM CDT SAT MAR 31 2012
MAIN FORECAST CONCERNS ARE ON CONVECTION CHANCES TONIGHT THROUGH
MONDAY NIGHT AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED A POTENT SHORTWAVE TROUGH OFF THE CALIFORNIA COASTLINE BY
ABOUT 500 MILES...RIDGING BUILDING DOWNSTREAM FROM THE FOUR CORNERS
REGION INTO WYOMING AND SOUTH DAKOTA...AND A WEAK SHORTWAVE OVER
EASTERN IOWA. CONDITIONS ARE DRY OVER THE FORECAST AREA NOW BEING IN
THE WAKE OF THE WEAK SHORTWAVE...PLUS PLENTY OF DRY AIR EXISTS ABOVE
850MB...NOTED ON THE 00Z MPX AND GRB SOUNDINGS. HOWEVER...A LOW
STRATUS DECK OF CLOUDS PERSISTS FROM MICHIGAN WESTWARD TO I-35...
RESULTING FROM MOISTURE TRAPPED BELOW A SUBSIDENCE INVERSION. THIS
IS ALSO SEEN ON THE AFOREMENTIONED SOUNDINGS. A SURFACE RIDGE OF
HIGH PRESSURE THAT STRETCHED FROM HUDSON BAY THROUGH SOUTHERN
WISCONSIN IS ALSO HELPING TO PROVIDE A COOL FLOW OF AIR...THUS NOT
ALLOWING THE STRATUS DECK TO DISSIPATE. TO THE WEST...MUCH WARMER
AIR WAS PRESENT UNDER THE BUILDING RIDGING OVER THE NORTHERN PLAINS.
850MB TEMPS CLIMB FROM -1C AT GRB TO 7C AT MPX...10C AT ABR AND 19C
AT UNR. THIS WARM AIR HAS BEEN SLOWLY PUSHING EAST AHEAD OF A LEE
TROUGH OVER THE WESTERN DAKOTAS...WITH 850MB PROFILER DATA SHOWING
SOUTHWEST WINDS OF 10-25 KT FROM THE PLAINS TO NEAR I-35 IN MN AND
IOWA. SO FAR ONLY HIGH BASED ALTOSTRATUS AND CIRRUS WERE PRESENT
WITH THE WARM ADVECTION.
TODAY AND TONIGHT...AS THE UPPER TROUGHING OFF THE COAST OF
CALIFORNIA PLOWS INTO THE WEST COAST...UPPER RIDGING LOOKS TO
FURTHER BUILD/STRENGTHEN DOWNSTREAM OVER THE PLAINS. AS A RESULT...
THE UPPER FLOW OVER THE FORECAST AREA STAYS NORTHWESTERLY THROUGH
TONIGHT. DESPITE THE NORTHWEST FLOW AT 500MB...LOWER LEVELS SUCH AS
850MB DEPICT A WARM ADVECTION PATTERN...WHICH ALLOWS THE CURRENT
SURFACE RIDGE TO MOVE OFF TO THE EAST. THE COMBINATION OF THE RIDGE
PUSHING EAST TODAY AND DAYTIME HEATING WILL ALLOW THE LOW CLOUDS TO
MIX/CLEAR OUT. SHOULD STILL SEE SOME HIGH BASED MID/HIGH CLOUD COVER
LIKE IS BEING OBSERVED OVER THE DAKOTAS NOW. SO OVERALL...A CLOUDY
BECOMING PARTLY SUNNY DAY. 925MB TEMPS CLIMB THROUGH THE DAY...
TOPPING OUT FROM 8C EAST TO 14C WEST BY 00Z. SOUNDINGS SUGGEST EASY
MIXING TO THIS LEVEL AND LIKELY UP TO 900MB...SUPPORTING HIGHS FROM
THE MID 50S EAST TO MID/UPPER 60S WEST. FOR TONIGHT...A WARM FRONT
OVER SOUTHWEST IOWA AT 00Z LOOKS LIKE IT WILL LIFT INTO NORTHEAST
IOWA BY 12Z. ISENTROPIC LIFT SEEN ON 300-305K SURFACES OVER THIS
FRONT COULD SUPPORT SOME CONVECTION SOUTH OF I-90. A SURGE OF
850MB DEWPOINTS OF 8-10C AND TEMPS AROUND 16C ACCOMPANY THE
ISENTROPIC LIFT...RESULTING IN ELEVATED CAPE VALUES OF 500 TO
PERHAPS AS HIGH AS 1000 J/KG IF THE 31.00Z NAM IS CORRECT. 1-6 KM
SHEAR VALUES OF 30-40 KT EXIST WHICH WOULD SUPPORT ORGANIZED
CONVECTION WITH LARGE HAIL BEING THE MAIN HAZARD. SINCE GOOD
CONSENSUS CONTINUES FOR THIS PRECIPITATION SOUTH OF I-90...RAISED
PRECIPITATION CHANCES UP ANOTHER 10 PERCENT. ONE THING TO WATCH
FOR IS THAT THE ECMWF REMAINS EVEN A LITTLE FARTHER SOUTH WITH THE
CONVECTION. WITH SCT-BKN MID/HIGH CLOUDS THROUGHOUT MUCH OF THE
NIGHT AND A GENERAL WARM ADVECTION PATTERN IN PLACE...ANTICIPATING
A MUCH WARMER NIGHT TONIGHT. FOLLOW A BLEND OF GUIDANCE FOR LOWS.
SUNDAY INTO SUNDAY NIGHT...THE WEST COAST TROUGH IS PROGGED TO PUSH
EAST IT NO THE ROCKIES...PERHAPS BEGINNING TO SPLIT INTO TWO PIECES
BY 12Z MONDAY AS IT RUNS INTO THE STRONGER RIDGING DOWNSTREAM. THIS
RIDGING SHOULD ENVELOP MUCH OF THE FORECAST AREA SUNDAY NIGHT.
ANTICIPATING THE SUBSIDENCE UNDER THIS UPPER RIDGE WILL BE ENOUGH TO
KEEP THE MAJORITY OF THE FORECAST AREA DRY DURING THIS PERIOD.
HOWEVER...THERE HAS BEEN A SIGNAL FOR A FRONTOGENESIS BAND OF
SHOWERS AND EMBEDDED THUNDERSTORMS TO DEVELOP SUNDAY NIGHT...FROM
NORTHERN MN INTO NORTHWEST WISCONSIN AND SOUTHEAST TO THE GREEN BAY
AREA. THIS IS MOST PREVALENT IN THE 31.00Z NAM...WHERE THE 31.00Z
GFS/UKMET/CANADIAN KEEP IT CONFINED MORE TO NORTHERN MN AND
NORTHWEST WISCONSIN. 31.00Z ECMWF IS COMPLETELY DRY. HAVE STAYED
TOWARDS THE DRIER SCENARIOS SEEING THE STRENGTH OF THE UPPER
RIDGE...BUT JUST IN CASE CONVECTION OCCURS IN NORTHWEST WISCONSIN
DID PLACE A 20 PERCENT CHANCE OVER TAYLOR COUNTY. OTHERWISE...
TEMPERATURES ARE THE MAIN CONCERN. THAT WARM FRONT LIFTING UP
TONIGHT LOOKS TO GET STUCK NEAR OR JUST SOUTH OF THE FORECAST
AREA...DUE TO THE NORTHWEST FLOW ALOFT AHEAD OF THE UPPER RIDGE
AXIS. STILL...925MB TEMPS CLIMB TO 14C EAST TO 20-22C WEST. THESE
READINGS SUGGEST A WIDE RANGE OF HIGHS...LIKELY FROM THE UPPER 60S
SAY IN MEDFORD TO NEAR WISCONSIN RAPIDS...TO LOW OR PERHAPS EVEN MID
80S FROM CHARLES CITY IA TO AUSTIN MN. WARM NIGHT LIKELY ON TAP
SUNDAY NIGHT GIVEN THE WARM START AND A PERSISTENT EAST TO SOUTHEAST
BREEZE.
MONDAY AND MONDAY NIGHT...VERY GOOD AGREEMENT EXISTS THAT THE
WESTERN UPPER TROUGH SPLITS WITH THE SOUTHERN PORTION CUTTING OFF
INTO AN UPPER LOW OVER NEW MEXICO. MEANWHILE...THE NORTHERN PORTION
ENDS UP TRACKING WELL TO OUR NORTH...MOVING INTO NORTHWEST ONTARIO
BY 12Z TUESDAY. THIS PUTS SOME QUESTION MARKS INTO FORCING FOR
PRECIPITATION. THE UPPER RIDGE THAT WAS OVER THE AREA AT 12Z MONDAY
WILL BREAK DOWN WITH THE APPROACH OF THE NORTHERN TROUGH FEATURE...
WHICH SHOULD HELP. ALSO...AT THE SURFACE...A TROUGH/COLD FRONT LOOKS
TO CROSS THE AREA TO PROVIDE SURFACE CONVERGENCE. HOWEVER...THE
TIMING OF THIS SURFACE FEATURE IS FAR FROM CERTAIN...WITH THE 31.00Z
ECMWF/CANADIAN/UKMET POSITION OVER WESTERN MINNESOTA COMPARED TO
CENTRAL/EASTERN WISCONSIN FROM THE 31.00Z GFS/NAM. THE LATTER
SOLUTIONS PRODUCE SOME SHOWER AND THUNDERSTORM ACTIVITY ON MONDAY
INTO MONDAY EVENING...WHICH MAKES SENSE GIVEN THE TIMING DURING PEAK
HEATING. MEANWHILE...THE ECMWF/CANADIAN/UKMET WAIT UNTIL MONDAY
NIGHT. LEANED A LITTLE MORE TOWARD THE ECMWF/CANADIAN/UKMET
GROUP...KEEPING CHANCES ONLY AT 20-30 FOR MONDAY AND 30-50 FOR
MONDAY NIGHT. IN ADDITION...TEMPERATURES FOR MONDAY ARE EXTREMELY
TRICKY DEPENDING ON THE FRONTAL TIMING. FOR NOW STAYED WITH A
CONSENSUS BLEND...BUT IF THE ECMWF IS RIGHT...MONDAY COULD LOOKS
JUST LIKE SUNDAY AND BE A FEW DEGREES WARMER. NEEDLESS TO SAY...A
LOT OF UNCERTAINTY.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
315 AM CDT SAT MAR 31 2012
QUIET WEATHER LOOKS TO DOMINATE THE ENTIRE LONG TERM PERIOD. A
CANADIAN HIGH PRESSURE RIDGE IS PROGGED BY THE 31.00Z
ECMWF/GFS/CANADIAN/UKMET TO BUILD INTO THE FORECAST AREA
TUESDAY...BEHIND MONDAY NIGHTS COLD FRONT...THEN ONLY DRIFT OFF TO
THE EAST THROUGH FRIDAY NIGHT. MEANWHILE...UPPER RIDGING LOOKS TO
BUILD ALOFT AHEAD OF DEEP TROUGHING DEVELOPING OVER THE WESTERN U.S.
THROUGH THE LONG TERM PERIOD. THIS SETUP FAVORS DRY CONDITIONS.
NOTE...THE 31.00Z GFS TRIES TO BRING THE CUT-OFF UPPER LOW IN NEW
MEXICO MONDAY NIGHT INTO IOWA BY 12Z THURSDAY...RESULTING IN SOME
SHOWERS OVER THE FORECAST AREA. THIS MODEL IS AN OUTLIER...EVEN
COMPARED TO ITS PREVIOUS RUN AND MOST OF ITS ENSEMBLE MEMBERS...AND
THEREFORE IGNORED AT THIS TIME. 850MB TEMPS WILL SLOWLY COOL...
DROPPING TO 2-4C FOR BOTH WEDNESDAY AND THURSDAY...BEFORE CLIMBING
BACK UP TO 4-6C ON FRIDAY AS THE SURFACE RIDGE MOVES EAST.
STILL...PLENTY OF SUN IS EXPECTED WHICH SHOULD HELP KEEP HIGHS ABOVE
NORMAL. CERTAINLY POSSIBLE TO SEE SOME FROST AT TIMES...ESPECIALLY
OVER CENTRAL WISCONSIN. IN ADDITION...MAY HAVE TO KEEP AN EYE ON
RELATIVE HUMIDITIES GIVEN WHAT LOOKS TO BE A BRIEF HUDSON BAY HIGH
SCENARIO...KNOWN TO MIX DEWPOINTS LOWER THAN FORECAST. HOWEVER...
WITH GREEN-UP WELL UNDERWAY...EVAPOTRANSPIRATION COULD KEEP
DEWPOINTS HIGHER MORE THAN WHAT WOULD NORMALLY OCCUR WITH A HUDSON
BAY HIGH.
&&
.AVIATION...TODAY AND TONIGHT
605 AM CDT SAT MAR 31 2012
LOW STRATUS WILL PERIST AT THE TAF SITES THROUGH MID MORNING
PRODUCING CEILINGS IN THE 200 TO 700 FT RANGE AT KRST...AND IN THE
800 TO 1100 FT RANGE AT KLSE. IN ADDITION...VISIBLITIES WILL BE
REDUCED INTO THE 2 TO 3 SM RANGE AT KRST THROUGH 14Z. LOOK FOR
CONDITIONS TO GRADUALLY IMPROVE TO MVFR IN THE 14 TO 16 Z
TIMEFRAME AS THE STRATUS STARTS TO BREAK UP. CLOUD BASES WILL RISE
TO AROUND 1500 FT LATE THIS MORNING...BECOMING SCATTERED BY EARLY
THIS AFTERNOON. PLAN ON SOUTHEAST WINDS OF 6 TO 10 KTS THROUGH THE
DAY. A WARM FRONT WILL LIFT INTO NORTHERN IOWA AND SOUTHWEST
WISCONSIN THIS EVENING AND WILL BE THE FOCUS FOR SHOWER AND
THUNDERSTORM DEVELOPMENT. THE STRONGEST 850 MB MOISTURE TRANSPORT
WILL OCCUR ACROSS NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THE
SHOWERS AND THUNDERSTORMS SHOULD STAY SOUTH OF THE TAF SITES LATE
THIS EVENING INTO THE OVERNIGHT HOURS WITH VFR CONDITIONS
EXPECTED. WILL HAVE TO KEEP A CLOSE WATCH ON THE PROGRESSION OF
THE WARM FROM LATE THIS AFTERNOON INTO EARLY THIS EVENING. IF
THUNDERSTORMS DEVELOP...A FEW STORMS WILL BE CAPABLE OF PRODUCING
LARGE HAIL AND BRIEF HEAVY RAINFALL. LATEST GUIDANCE IS SUGGESTING
FOG DEVELOPMENT LATE TONIGHT INTO EARLY SUNDAY MORNING...MAINLY
ALONG AND NORTH OF THE WARM FRONT. CURRENT THINKING IS THAT THE
WINDS NEAR THE SURFACE WILL PROVIDE ENOUGH MIXING TO INHIBIT FOG
DEVELOPMENT. IF THE WARM FRONT ADVANCES FURTHER NORTH LATE
TONIGHT...AND DECOUPLING OCCURS...FOG COULD IMPACT THE TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 AM CDT SAT MAR 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
315 AM CDT SAT MAR 31 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
315 AM CDT SAT MAR 31 2012
MAIN FORECAST CONCERNS ARE ON CONVECTION CHANCES TONIGHT THROUGH
MONDAY NIGHT AS WELL AS TEMPERATURES THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED A POTENT SHORTWAVE TROUGH OFF THE CALIFORNIA COASTLINE BY
ABOUT 500 MILES...RIDGING BUILDING DOWNSTREAM FROM THE FOUR CORNERS
REGION INTO WYOMING AND SOUTH DAKOTA...AND A WEAK SHORTWAVE OVER
EASTERN IOWA. CONDITIONS ARE DRY OVER THE FORECAST AREA NOW BEING IN
THE WAKE OF THE WEAK SHORTWAVE...PLUS PLENTY OF DRY AIR EXISTS ABOVE
850MB...NOTED ON THE 00Z MPX AND GRB SOUNDINGS. HOWEVER...A LOW
STRATUS DECK OF CLOUDS PERSISTS FROM MICHIGAN WESTWARD TO I-35...
RESULTING FROM MOISTURE TRAPPED BELOW A SUBSIDENCE INVERSION. THIS
IS ALSO SEEN ON THE AFOREMENTIONED SOUNDINGS. A SURFACE RIDGE OF
HIGH PRESSURE THAT STRETCHED FROM HUDSON BAY THROUGH SOUTHERN
WISCONSIN IS ALSO HELPING TO PROVIDE A COOL FLOW OF AIR...THUS NOT
ALLOWING THE STRATUS DECK TO DISSIPATE. TO THE WEST...MUCH WARMER
AIR WAS PRESENT UNDER THE BUILDING RIDGING OVER THE NORTHERN PLAINS.
850MB TEMPS CLIMB FROM -1C AT GRB TO 7C AT MPX...10C AT ABR AND 19C
AT UNR. THIS WARM AIR HAS BEEN SLOWLY PUSHING EAST AHEAD OF A LEE
TROUGH OVER THE WESTERN DAKOTAS...WITH 850MB PROFILER DATA SHOWING
SOUTHWEST WINDS OF 10-25 KT FROM THE PLAINS TO NEAR I-35 IN MN AND
IOWA. SO FAR ONLY HIGH BASED ALTOSTRATUS AND CIRRUS WERE PRESENT
WITH THE WARM ADVECTION.
TODAY AND TONIGHT...AS THE UPPER TROUGHING OFF THE COAST OF
CALIFORNIA PLOWS INTO THE WEST COAST...UPPER RIDGING LOOKS TO
FURTHER BUILD/STRENGTHEN DOWNSTREAM OVER THE PLAINS. AS A RESULT...
THE UPPER FLOW OVER THE FORECAST AREA STAYS NORTHWESTERLY THROUGH
TONIGHT. DESPITE THE NORTHWEST FLOW AT 500MB...LOWER LEVELS SUCH AS
850MB DEPICT A WARM ADVECTION PATTERN...WHICH ALLOWS THE CURRENT
SURFACE RIDGE TO MOVE OFF TO THE EAST. THE COMBINATION OF THE RIDGE
PUSHING EAST TODAY AND DAYTIME HEATING WILL ALLOW THE LOW CLOUDS TO
MIX/CLEAR OUT. SHOULD STILL SEE SOME HIGH BASED MID/HIGH CLOUD COVER
LIKE IS BEING OBSERVED OVER THE DAKOTAS NOW. SO OVERALL...A CLOUDY
BECOMING PARTLY SUNNY DAY. 925MB TEMPS CLIMB THROUGH THE DAY...
TOPPING OUT FROM 8C EAST TO 14C WEST BY 00Z. SOUNDINGS SUGGEST EASY
MIXING TO THIS LEVEL AND LIKELY UP TO 900MB...SUPPORTING HIGHS FROM
THE MID 50S EAST TO MID/UPPER 60S WEST. FOR TONIGHT...A WARM FRONT
OVER SOUTHWEST IOWA AT 00Z LOOKS LIKE IT WILL LIFT INTO NORTHEAST
IOWA BY 12Z. ISENTROPIC LIFT SEEN ON 300-305K SURFACES OVER THIS
FRONT COULD SUPPORT SOME CONVECTION SOUTH OF I-90. A SURGE OF
850MB DEWPOINTS OF 8-10C AND TEMPS AROUND 16C ACCOMPANY THE
ISENTROPIC LIFT...RESULTING IN ELEVATED CAPE VALUES OF 500 TO
PERHAPS AS HIGH AS 1000 J/KG IF THE 31.00Z NAM IS CORRECT. 1-6 KM
SHEAR VALUES OF 30-40 KT EXIST WHICH WOULD SUPPORT ORGANIZED
CONVECTION WITH LARGE HAIL BEING THE MAIN HAZARD. SINCE GOOD
CONSENSUS CONTINUES FOR THIS PRECIPITATION SOUTH OF I-90...RAISED
PRECIPITATION CHANCES UP ANOTHER 10 PERCENT. ONE THING TO WATCH
FOR IS THAT THE ECMWF REMAINS EVEN A LITTLE FARTHER SOUTH WITH THE
CONVECTION. WITH SCT-BKN MID/HIGH CLOUDS THROUGHOUT MUCH OF THE
NIGHT AND A GENERAL WARM ADVECTION PATTERN IN PLACE...ANTICIPATING
A MUCH WARMER NIGHT TONIGHT. FOLLOW A BLEND OF GUIDANCE FOR LOWS.
SUNDAY INTO SUNDAY NIGHT...THE WEST COAST TROUGH IS PROGGED TO PUSH
EAST IT NO THE ROCKIES...PERHAPS BEGINNING TO SPLIT INTO TWO PIECES
BY 12Z MONDAY AS IT RUNS INTO THE STRONGER RIDGING DOWNSTREAM. THIS
RIDGING SHOULD ENVELOP MUCH OF THE FORECAST AREA SUNDAY NIGHT.
ANTICIPATING THE SUBSIDENCE UNDER THIS UPPER RIDGE WILL BE ENOUGH TO
KEEP THE MAJORITY OF THE FORECAST AREA DRY DURING THIS PERIOD.
HOWEVER...THERE HAS BEEN A SIGNAL FOR A FRONTOGENESIS BAND OF
SHOWERS AND EMBEDDED THUNDERSTORMS TO DEVELOP SUNDAY NIGHT...FROM
NORTHERN MN INTO NORTHWEST WISCONSIN AND SOUTHEAST TO THE GREEN BAY
AREA. THIS IS MOST PREVALENT IN THE 31.00Z NAM...WHERE THE 31.00Z
GFS/UKMET/CANADIAN KEEP IT CONFINED MORE TO NORTHERN MN AND
NORTHWEST WISCONSIN. 31.00Z ECMWF IS COMPLETELY DRY. HAVE STAYED
TOWARDS THE DRIER SCENARIOS SEEING THE STRENGTH OF THE UPPER
RIDGE...BUT JUST IN CASE CONVECTION OCCURS IN NORTHWEST WISCONSIN
DID PLACE A 20 PERCENT CHANCE OVER TAYLOR COUNTY. OTHERWISE...
TEMPERATURES ARE THE MAIN CONCERN. THAT WARM FRONT LIFTING UP
TONIGHT LOOKS TO GET STUCK NEAR OR JUST SOUTH OF THE FORECAST
AREA...DUE TO THE NORTHWEST FLOW ALOFT AHEAD OF THE UPPER RIDGE
AXIS. STILL...925MB TEMPS CLIMB TO 14C EAST TO 20-22C WEST. THESE
READINGS SUGGEST A WIDE RANGE OF HIGHS...LIKELY FROM THE UPPER 60S
SAY IN MEDFORD TO NEAR WISCONSIN RAPIDS...TO LOW OR PERHAPS EVEN MID
80S FROM CHARLES CITY IA TO AUSTIN MN. WARM NIGHT LIKELY ON TAP
SUNDAY NIGHT GIVEN THE WARM START AND A PERSISTENT EAST TO SOUTHEAST
BREEZE.
MONDAY AND MONDAY NIGHT...VERY GOOD AGREEMENT EXISTS THAT THE
WESTERN UPPER TROUGH SPLITS WITH THE SOUTHERN PORTION CUTTING OFF
INTO AN UPPER LOW OVER NEW MEXICO. MEANWHILE...THE NORTHERN PORTION
ENDS UP TRACKING WELL TO OUR NORTH...MOVING INTO NORTHWEST ONTARIO
BY 12Z TUESDAY. THIS PUTS SOME QUESTION MARKS INTO FORCING FOR
PRECIPITATION. THE UPPER RIDGE THAT WAS OVER THE AREA AT 12Z MONDAY
WILL BREAK DOWN WITH THE APPROACH OF THE NORTHERN TROUGH FEATURE...
WHICH SHOULD HELP. ALSO...AT THE SURFACE...A TROUGH/COLD FRONT LOOKS
TO CROSS THE AREA TO PROVIDE SURFACE CONVERGENCE. HOWEVER...THE
TIMING OF THIS SURFACE FEATURE IS FAR FROM CERTAIN...WITH THE 31.00Z
ECMWF/CANADIAN/UKMET POSITION OVER WESTERN MINNESOTA COMPARED TO
CENTRAL/EASTERN WISCONSIN FROM THE 31.00Z GFS/NAM. THE LATTER
SOLUTIONS PRODUCE SOME SHOWER AND THUNDERSTORM ACTIVITY ON MONDAY
INTO MONDAY EVENING...WHICH MAKES SENSE GIVEN THE TIMING DURING PEAK
HEATING. MEANWHILE...THE ECMWF/CANADIAN/UKMET WAIT UNTIL MONDAY
NIGHT. LEANED A LITTLE MORE TOWARD THE ECMWF/CANADIAN/UKMET
GROUP...KEEPING CHANCES ONLY AT 20-30 FOR MONDAY AND 30-50 FOR
MONDAY NIGHT. IN ADDITION...TEMPERATURES FOR MONDAY ARE EXTREMELY
TRICKY DEPENDING ON THE FRONTAL TIMING. FOR NOW STAYED WITH A
CONSENSUS BLEND...BUT IF THE ECMWF IS RIGHT...MONDAY COULD LOOKS
JUST LIKE SUNDAY AND BE A FEW DEGREES WARMER. NEEDLESS TO SAY...A
LOT OF UNCERTAINTY.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
315 AM CDT SAT MAR 31 2012
QUIET WEATHER LOOKS TO DOMINATE THE ENTIRE LONG TERM PERIOD. A
CANADIAN HIGH PRESSURE RIDGE IS PROGGED BY THE 31.00Z
ECMWF/GFS/CANADIAN/UKMET TO BUILD INTO THE FORECAST AREA
TUESDAY...BEHIND MONDAY NIGHTS COLD FRONT...THEN ONLY DRIFT OFF TO
THE EAST THROUGH FRIDAY NIGHT. MEANWHILE...UPPER RIDGING LOOKS TO
BUILD ALOFT AHEAD OF DEEP TROUGHING DEVELOPING OVER THE WESTERN U.S.
THROUGH THE LONG TERM PERIOD. THIS SETUP FAVORS DRY CONDITIONS.
NOTE...THE 31.00Z GFS TRIES TO BRING THE CUT-OFF UPPER LOW IN NEW
MEXICO MONDAY NIGHT INTO IOWA BY 12Z THURSDAY...RESULTING IN SOME
SHOWERS OVER THE FORECAST AREA. THIS MODEL IS AN OUTLIER...EVEN
COMPARED TO ITS PREVIOUS RUN AND MOST OF ITS ENSEMBLE MEMBERS...AND
THEREFORE IGNORED AT THIS TIME. 850MB TEMPS WILL SLOWLY COOL...
DROPPING TO 2-4C FOR BOTH WEDNESDAY AND THURSDAY...BEFORE CLIMBING
BACK UP TO 4-6C ON FRIDAY AS THE SURFACE RIDGE MOVES EAST.
STILL...PLENTY OF SUN IS EXPECTED WHICH SHOULD HELP KEEP HIGHS ABOVE
NORMAL. CERTAINLY POSSIBLE TO SEE SOME FROST AT TIMES...ESPECIALLY
OVER CENTRAL WISCONSIN. IN ADDITION...MAY HAVE TO KEEP AN EYE ON
RELATIVE HUMIDITIES GIVEN WHAT LOOKS TO BE A BRIEF HUDSON BAY HIGH
SCENARIO...KNOWN TO MIX DEWPOINTS LOWER THAN FORECAST. HOWEVER...
WITH GREEN-UP WELL UNDERWAY...EVAPOTRANSPIRATION COULD KEEP
DEWPOINTS HIGHER MORE THAN WHAT WOULD NORMALLY OCCUR WITH A HUDSON
BAY HIGH.
&&
.AVIATION...THROUGH 06Z SUNDAY
1146 PM CDT FRI MAR 30 2012
MAIN CHALLENGE REMAINS ON CEILING HEIGHTS AND POTENTIAL CLEARING
TREND ON SATURDAY. WIDESPREAD MVFR CEILINGS HAVE BEEN PRESENT OVER
THE TAFS SITES THROUGHOUT THE EVENING. STRATUS WAS BEGINNING TO
REFORM WHERE SKIES HAD CLEARED ACROSS SOUTH CENTRAL MINNESOTA.
31.02Z RUC AND 31.00Z NAM BUFKIT SOUNDINGS SHOW LOW LEVEL MOISTURE
TRAPPED UNDER THE INVERSION THROUGH AT LEAST MIDDAY SATURDAY. WILL
LIKELY SEE CEILINGS CONTINUE TO DROP INTO THE IFR CATEGORY AT BOTH
TAF SITES BETWEEN 06Z-09Z...AND THEN BEGIN TO RAISE AFTER 15Z INTO
THE MVFR CATEGORY AND FINALLY SCATTERED OUT BETWEEN 17Z-19Z.
NEXT QUESTION IS THE POTENTIAL FOR CONVECTION SATURDAY NIGHT. LOW
LEVEL MOISTURE TRANSPORT NOSES NORTHWARD INTO IOWA...WITH BOTH THE
NAM AND GFS GENERATING CONVECTION OVER NORTHEAST IOWA BETWEEN 00Z-
06Z. AT THIS POINT IT LOOKS LIKE CONVECTION WOULD BE SOUTH OF THE
TAF SITES...BUT WILL HAVE TO WATCHED. WILL NOT MENTION ANYTHING AT
THIS TIME...WITH THE EXCEPTION OF SOME SCATTERED CUMULUS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 AM CDT SAT MAR 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1146 PM CDT FRI MAR 30 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
343 PM CDT FRI MAR 30 2012
AT 3 PM...THE COMBINATION OF EXTENSIVE CLOUD COVER AND EASTERLY
WINDS BRINGING COOLER AIR INTO THE REGION FROM MICHIGAN...
TEMPERATURES ACROSS WISCONSIN WERE HELD IN THE 35 TO 45 DEGREE
RANGE. MEANWHILE A BIT OF SUNSHINE ALLOWED TEMPERATURES TO
CLIMB INTO THE LOWER AND MID 50S.
THE MODELS ARE IN GENERAL AGREEMENT THAT THE LOW CLOUDS WILL
REMAIN TRAPPED UNDERNEATH A SUBSIDENCE INVERSION INTO SATURDAY
MORNING. THESE CLOUDS WILL KEEP TEMPERATURES FROM FALLING BELOW
FREEZING ACROSS WESTERN WISCONSIN TONIGHT. DUE TO THIS...REMOVED
THE MENTION OF FROST ACROSS NORTH-CENTRAL AND CENTRAL WISCONSIN
FOR TONIGHT.
ON SATURDAY AFTERNOON...THE NAM/WRF CONTINUES TO GENERATE A CLUSTER
OF SHOWERS AND THUNDERSTORMS ACROSS NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. THIS PRECIPITATION IS DEVELOPING ON THE NOSE AN 850 MB
JET. THIS PRECIPITATION THEN SHIFTS SOUTH AND EAST OF AREA.
MEANWHILE THE REMAINDER OF THE MODELS CONTINUE TO KEEP THIS PERIOD
DRY. OVERLY...NOT THAT IMPRESSED THE MOISTURE TRANSPORT IN THE
NAM/WRF...SO TREATED IT AS AN OUTLIER AND WENT DRY.
ON SATURDAY NIGHT...THERE IS MORE OF A CONSISTENT SIGNAL IN THE
MODELS THAT THE LOW LEVEL JET WILL BRING SOME MODEST MOISTURE
TRANSPORT INTO NORTHEAST IOWA AND SOUTHWEST WISCONSIN. IN ADDITION...
A BACK DOOR COLD FRONT WILL BE PUSHING SOUTHWEST ACROSS THE AREA.
THIS FRONT WILL BE THE FOCUS FOR THE DEVELOPMENT OF AN AREA OF
PRECIPITATION ACROSS NORTHEAST IOWA AND SOUTHWEST WISCONSIN. WITH
0-3 KM MOST UNSTABLE CAPES CLIMBING UP TO 500 J/KG...THERE SHOULD
BE ENOUGH INSTABILITY FOR THE DEVELOPMENT OF A FEW THUNDERSTORMS.
WITH 1-6 KM BULK SHEAR RUNNING BETWEEN 35 AND 40 KNOTS...THERE MAY
BE ENOUGH SHEAR FOR A FEW THUNDERSTORMS TO PRODUCE HAIL.
ON SUNDAY...THERE CONTINUES TO BE MUCH UNCERTAINTY ON THE
TEMPERATURES ACROSS THE REGION. THIS IS DUE TO THE UNCERTAINTY
THAT EXISTS ON WHERE THE WARM FRONT WILL BE LOCATED. TO THE SOUTH
AND WEST OF THE FRONT...TEMPERATURES WILL CLIMB WELL INTO THE 70S.
MEANWHILE NORTH AND EAST OF THIS FRONT...TEMPERATURES WILL REMAIN
IN THE 60S AND 70S. DUE TO THE POTENTIAL FOR MAJOR TEMPERATURE BUSTS...
WENT VERY CONSERVATIVE ON THE TEMPERATURE FORECAST FOR THIS TIME PERIOD.
.LONG TERM...MONDAY THROUGH FRIDAY
343 PM CDT FRI MAR 30 2012
ON MONDAY...THE 700 MB TEMPERATURES IN THE GFS ARE RUNNING BETWEEN
4 AND 6C. MEANWHILE THE OTHER MODELS SUGGEST 700 MB TEMPERATURES
AROUND 8C. AS A RESULT...THE OTHER MODELS SUGGEST MORE CAPPING.
ANOTHER DIFFERENCE IN THE GFS IS THAT ITS WARM FRONT IS MUCH FURTHER
SOUTH THAN THE OTHER MODELS. THESE DIFFERENCES ARE THE MAIN REASONS
WHY IT CONTINUES TO GENERATE PRECIPITATION ACROSS THE REGION AND THE
OTHER MODELS SUGGEST THAT THE AREA WILL REMAIN DRY. SINCE EITHER
SCENARIO IS STILL POSSIBLE...JUST LOWERED THE PRECIPITATION
CHANCES BY 10 TO 20 PERCENT FOR NOW. IF THE CAP HAPPENS TO BREAK...
THERE IS A DECENT AMOUNT OF INSTABILITY /NAM 1500-3000 J/KG AND
GFS UP TO 1500 J/KG/. THIS WOULD RESULT IN SOME THUNDERSTORM
DEVELOPMENT. HOWEVER THE 0-6 KM SHEAR IS LESS THAN 30 KNOTS...
SO PROBABLY NOT ENOUGH TO ORGANIZE THE CONVECTION.
ON MONDAY NIGHT...ALL OF THE MODELS ARE IN GOOD AGREEMENT THAT A
COLD FRONT WILL MOVE EAST THROUGH THE REGION. WITH THE BEST UPPER
LEVEL SUPPORT BEING WELL TO THE NORTH AND SOUTH OF THE AREA...NOT
EXPECTING TOO MUCH PRECIPITATION FROM THIS FRONT. A MATTER OF
FACT...THE SOUTHERN SHORT WAVE /WHICH IS BEGINNING TO TRANSITION TO
A CUT OFF LOW/ IS INTERCEPTING THE RICHER MOISTURE FROM THE GULF
OF MEXICO. WITH CAPES STILL UP TO 1500 J/KG...THERE SHOULD BE
ENOUGH INSTABILITY FOR THUNDERSTORMS...BUT THE BEST 0-6 KM SHEAR
SLIDES OFF TO OUR NORTH IN RESPONSE TO THE NORTHERN SHORT WAVE
MOVING NORTHEAST AWAY FROM THE AREA.
FROM TUESDAY THROUGH FRIDAY...THE MODELS ARE IN GOOD AGREEMENT THAT
AN OMEGA BLOCK WILL DEVELOP ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY. FURTHER TO THE SOUTH...A CLOSED LOW WILL BE MOVING SLOWLY
THROUGH THE SOUTHERN PLAINS AND LOWER MISSISSIPPI RIVER VALLEY. THIS
HIGH WILL PROVIDE DRY WEATHER AND SLIGHTLY ABOVE NORMAL
TEMPERATURES DURING THIS TIME PERIOD.
&&
.AVIATION...THROUGH 06Z SUNDAY
1146 PM CDT FRI MAR 30 2012
MAIN CHALLENGE REMAINS ON CEILING HEIGHTS AND POTENTIAL CLEARING
TREND ON SATURDAY. WIDESPREAD MVFR CEILINGS HAVE BEEN PRESENT OVER
THE TAFS SITES THROUGHOUT THE EVENING. STRATUS WAS BEGINNING TO
REFORM WHERE SKIES HAD CLEARED ACROSS SOUTH CENTRAL MINNESOTA.
31.02Z RUC AND 31.00Z NAM BUFKIT SOUNDINGS SHOW LOW LEVEL MOISTURE
TRAPPED UNDER THE INVERSION THROUGH AT LEAST MIDDAY SATURDAY. WILL
LIKELY SEE CEILINGS CONTINUE TO DROP INTO THE IFR CATEGORY AT BOTH
TAF SITES BETWEEN 06Z-09Z...AND THEN BEGIN TO RAISE AFTER 15Z INTO
THE MVFR CATEGORY AND FINALLY SCATTERED OUT BETWEEN 17Z-19Z.
NEXT QUESTION IS THE POTENTIAL FOR CONVECTION SATURDAY NIGHT. LOW
LEVEL MOISTURE TRANSPORT NOSES NORTHWARD INTO IOWA...WITH BOTH THE
NAM AND GFS GENERATING CONVECTION OVER NORTHEAST IOWA BETWEEN 00Z-
06Z. AT THIS POINT IT LOOKS LIKE CONVECTION WOULD BE SOUTH OF THE
TAF SITES...BUT WILL HAVE TO WATCHED. WILL NOT MENTION ANYTHING AT
THIS TIME...WITH THE EXCEPTION OF SOME SCATTERED CUMULUS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
343 PM CDT FRI MAR 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RABERDING
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1120 PM MDT SUN APR 1 2012
.UPDATE...
ISSUED AT 1051 PM MDT SUN APR 1 2012
ADJUSTED START TIME OF WIND ADVISORY FOR WESTERN PART OF CWA BASED
ON 00Z GUIDANCE. LOOKS LIKE ADVISORY WINDS SHOULD DEVELOP OVER
THESE LOCATIONS AS EARLY AS 09Z...SPREADING EASTWARD THROUGH
12Z. STRONGEST WINDS ALOFT STILL LOOK TO BE IN THE 12-18Z TIME
PERIOD ACROSS THE AREA. 00Z GFS AND MAV GUIDANCE ARE THE MOST
BULLISH ON DAYTIME WINDS WITH SUSTAINED WINDS WITHIN WARNING
CRITERIA. LATEST NAM/SREF/RUC/HRRR ALL MUCH LESS...WITH WINDS
REMAINING WITHIN ADVISORY LEVELS. WITH THIS IN MIND I DECIDED TO
KEEP ADVISORY RATHER THAN UPGRADING AT THIS TIME.
UPDATE ISSUED AT 846 PM MDT SUN APR 1 2012
MADE FURTHER ADJUSTMENTS TO WIND FORECAST IN THE 06-15Z PERIOD
BASED ON LATEST RUC AND NAM TIMING OF FROPA. 00Z NAM STILL
INDICATING HIGH END ADVISORY/NEAR WARNING CRITERIA WINDS EARLY
MONDAY MORNING OVER EASTERN COLORADO. 00Z NAM AND LATEST SREF AND
RUC ARE LESS BULLISH THAN EARLIER ON WARNING CRITERIA. I HAVE
KEPT ADVISORY IN PLACE FOR NOW...AND WILL PROBABLY WAIT FOR 00Z
GFS TO MAKE FINAL DECISION ON FURTHER ADJUSTMENTS OR POSSIBLE
UPGRADES.
UPDATE ISSUED AT 554 PM MDT SUN APR 1 2012
MADE MINOR CHANGES TO WIND FORECAST TO ACCOUNT FOR WINDS
INCREASING QUICKER OVER WESTERN PARTS OF CWA AFTER 09Z TONIGHT AND
TO BUMP UP WIND GUST WORDING. I ALSO ADDED PATCHY BLOWING
DUST TO WEATHER GRIDS. IM CONCERNED WE COULD SEE WARNING CRITERIA
WINDS OVER WESTERN PARTS OF THE CWA MONDAY MORNING...HOWEVER NOT
A LOT OF NEW DATA TO LOOK AT AND MAKE A DECISION YET. WILL
PROBABLY WAIT UNTIL 00Z DATA COMES IN TO FURTHER FINE TUNE WIND
FORECAST. OTHER CHANGE WAS TO ADJUST TIMING OF PRECIP
MONDAY...TO INCLUDE RAIN SHOWERS MONDAY AFTERNOON IN THE SOUTH AND
WEST. 18Z NAM/GFS BOTH INDICATING AXIS OF FRONTOGENISIS MOVING NORTH
AND EAST ALONG WITH DECENT MID LEVEL MOISTURE IN THE 21-00Z
TIME-FRAME...SO EARLIER ARRIVAL OF RAIN CANT BE RULED OUT.
RED FLAG CONDITIONS CONTINUE OVER MANY LOCATIONS ACROSS THE
AREA...SO I PLAN ON LETTING THE RFW EXPIRE ON TIME AT 02Z.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 238 PM MDT SUN APR 1 2012
SOUTHWEST FLOW WILL BE OVER THE REGION TONIGHT. THE UPPER LOW WILL
MOVE INTO SOUTHWEST NEW MEXICO MONDAY. A SURFACE TROUGH WILL BE OVER
EASTERN COLORADO TONIGHT. A COLD FRONT WILL PUSH SOUTH ACROSS
NORTHWEST KANSAS EARLY MONDAY.
SUBSIDENCE WILL CONTINUE OVER THE FA TONIGHT SO POPS WILL BE NIL.
SOME LIGHT PRECIPITATION WILL BE POSSIBLE MONDAY MORNING OVER
WESTERN PORTIONS OF EASTERN COLORADO WHILE DYNAMICS FROM THE UPPER
LOW ARE STILL REASONABLY CLOSE. BY MONDAY AFTERNOON THE LOW WILL
MOVE FAR ENOUGH SOUTH SO THAT CHANCES ARE MUCH LOWER. PLAN TO
CONTINUE SLIGHT CHANCE POPS IN EASTERN COLORADO MONDAY MORNING AND
THEN SILENT POPS MONDAY AFTERNOON. THE REST OF THE FA WILL HAVE NIL
POPS.
STRONG WINDS ARE THE MAIN FOCUS OF THE FORECAST FOR MONDAY. THE
GFS/NAM BOTH INDICATE GUSTS TO AROUND 50 MPH BETWEEN 12-15Z.
SUSTAINED WIND WILL BE STRONG ENOUGH TO SUPPORT A WIND ADVISORY ALL
DAY. SEE DETAILS ON THE WIND ADVISORY BELOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 238 PM MDT SUN APR 1 2012
MONDAY NIGHT WINDS WILL REMAIN GUSTY THROUGH THE NIGHT...WITH THE
STRONGEST GUSTS DURING THE EVENING...AS THE COOLER TEMPERATURES
ABOVE THE GROUND ALLOW THE STRONG WINDS TO MIX TO THE SURFACE. AS
SUCH HAVE THE WIND ADVISORY EXTENDING INTO THE EVENING. DURING THE
LATE EVENING THE WINDS WILL SLOWLY DECLINE AS THE COOLER
TEMPERATURES AT THE SURFACE CAUSE MIXING TO DECLINE.
THERE STILL REMAINS SOME UNCERTAINTY WITH TRACK OF THE CLOSED UPPER
LEVEL LOW MONDAY NIGHT THROUGH WEDNESDAY. MODELS IN GENERAL HAVE
SLOWED THE SYSTEM DOWN FROM YESTERDAY...WHICH SEEMS REASONABLE SINCE
THE CLOSED LOW WILL BE OUTSIDE OF THE MAIN UPPER LEVEL FLOW. THE
12Z NAM IS FURTHER SOUTH THAN IT WAS AT THIS TIME YESTERDAY WHILE
THE 12Z GFS IS FURTHER NORTH. PREFERENCE IS THE SREF AND NAM SINCE
THEY ARE SLOWER AND HAVE MORE RUN TO RUN CONSISTENCY WITH THE TRACK
OF THE CLOSED LOW AND ARE IN LINE WITH THE MAJORITY OF THE 6Z
GEFS...BUT FAVORED MOSTLY THE SREF FOR DETERMINING AREAS OF PRECIP.
SINCE THE NAM DRASTICALLY CUT BACK THE PRECIP. FOR THIS STORM
SYSTEM. GENERALLY THINKING A SLOWER TREND OF THE PRECIPITATION
MONDAY NIGHT THROUGH TUESDAY EVENING LOOKS TO BE THE WAY TO
GO...WITH LOCATIONS SOUTH OF HIGHWAY 24 LOOKING TO HAVE THE BEST
CHANCE FOR PRECIPITATION UNTIL THE STORM SYSTEM MOVES FURTHER EAST.
MONDAY EVENING HAVE SLIGHT CHANCES FOR PRECIPITATION OVER EASTERN
COLORADO AS THE 750-650MB SATURATES WITH ISENTROPIC LIFT OVER THAT
AREA. OVERNIGHT PRECIP. CHANCES INCREASE OVER THE ENTIRE AREA FROM
SOUTHWEST TO NORTHEAST AS ISENTROPIC LIFT OVERSPREADS THE AREA AND
MOISTURE AHEAD OF THE CLOSED LOW BEGINS TO MOVE NORTH INTO THE
AREA. SOME LOCATIONS IN EASTERN COLORADO MAY RECEIVE SOME SNOW WITH
LOW TEMPERATURES AROUND FREEZING.
TUESDAY PRECIP. CHANCES SLOWLY INCREASE AS THE CIRCULATION OF THE
CLOSED LOW CONTINUES TO BRING MOISTURE INTO THE AREA. BIGGEST
QUESTION IS HOW FAR NORTH THE MOISTURE WILL MAKE IT AS THE CLOSED
LOW MOVES EAST. WITH MORE UNCERTAINTY THAT THERE WILL BE MOISTURE
FOR THE ISENTROPIC LIFT TO WORK WITH AS ONE MOVES NORTH...HAVE
PRECIP. CHANCES DECREASING TO THE NORTH. WINDS WILL CONTINUE TO
DECREASE AS THE UPPER LEVEL WINDS DECLINE...BECOMING LIGHT BY
EVENING.
TUESDAY NIGHT PRECIPITATION CHANCES BEGIN TO DECREASE FROM EAST TO
WEST AS THE CLOSED LOW AND WRAP AROUND MOISTURE MOVE EAST.
FOR WEDNESDAY THROUGH SUNDAY THE MAIN FOCUS WILL BE THE CLOSED LOW
MOVING OUT OF THE AREA AND THUNDERSTORM CHANCES TOWARD THE END OF
THE WEEK.
WEDNESDAY THE CLOSED CONTINUES TO MOVE OUT OF THE AREA. BOTH THE
GFS AND ECMWF HAVE THE CLOSED LOW MOVING EAST OVER KANSAS...WHILE
THE NAM/SREF HAVE THE CLOSED LOW MOVING EAST OVER OKLAHOMA. DESPITE
THE DIFFERING POSITIONS OF THE LOW...THE MODELS AGREE THAT PRECIP.
CHANCES WILL DECLINE FROM EAST TO WEST DURING THE DAY AS THE CLOSED
LOW MOVES EAST. BEHIND THE CLOSED LOW A SHORT WAVE RIDGE MOVES OVER
THE AREA.
THURSDAY THE NEXT UPPER LEVEL TROUGH MOVES ON SHORE. BY FRIDAY
MORNING THE TROUGH WILL BE OVER THE INTER MOUNTAIN WEST. AT THE
SURFACE A LEE SIDE TROUGH DEVELOPS OVER EASTERN COLORADO AS THE
UPPER LEVEL TROUGH APPROACHES THE TRI-STATE AREA. FRIDAY SOUTHERLY
AHEAD OF AN UPPER LEVEL SHORT WAVE TROUGH BRING UP MOISTURE FROM
THE SOUTH. WITH INSTABILITY TO WORK WITH CANNOT RULE OUT A FEW
THUNDERSTORMS FROM FORMING OVER THE EASTERN PART OF THE AREA DURING
THE AFTERNOON. FRIDAY NIGHT A COLD FRONT MOVES THROUGH THE AREA.
OVER THE EAST THUNDERSTORM CHANCES CONTINUE WITH ELEVATED INSTABILITY
IN PLACE AND THE LOW LEVEL JET MOVING OVER THOSE AREAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1119 PM MDT SUN APR 1 2012
VFR CONDITIONS ARE EXPECTED THROUGH MONDAY AFTERNOON...WITH MVFR
CIGS POSSIBLE MONDAY EVENING. THESE LOW CIGS ARE PRIMARILY TIED
TO MOISTURE ADVECTION AND PRECIP MOVING IN FROM THE SOUTH WHICH IS
STILL IN QUESTION AT BOTH TERMINALS DUE TO UNCERTAINTLY REGARDING
THE POSITION OF THE UPPER LOW MONDAY NIGHT. KGLD IS MOST LIKELY TO
SEE RAIN SHOWERS MONDAY EVENING...HOWEVER I WAS NOT CONFIDENT
ENOUGH TO ADD MORE THAN VCSH DURING THIS TAF CYCLE AND KEPT VFR IN
PLACE.
A COLD FRONT IS STILL ON TRACK TO PASS THROUGH THE REGION
FROM THE NW TO THE SE EARLY IN THE TAF PERIOD...WITH GUSTY WINDS
DEVELOPING AT BOTH TERMINALS. KGLD WILL BE FIRST TO SEE WINDS
SHIFT TO THE NORTH AND INCREASE IN THE 09Z-12Z PERIOD...WITH KMCK
IN THE 12Z-15Z TIME FRAME. THE STRONGEST WINDS WILL BE IN THE
MORNING WITH WIND GUSTS 40-45KT. WIND GUSTS AROUND 30KT WILL
CONTINUE THROUGH MONDAY EVENING AT BOTH TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY FROM 3 AM TO 9 PM MDT MONDAY FOR COZ090>092.
KS...WIND ADVISORY FROM 3 AM MDT /4 AM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR KSZ001-013-027.
WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR KSZ002>004-014>016-028-029-041-042.
NE...WIND ADVISORY FROM 3 AM TO 9 PM MDT MONDAY FOR NEZ079.
WIND ADVISORY FROM 7 AM THIS MORNING TO 10 PM CDT THIS EVENING
FOR NEZ080-081.
&&
$$
UPDATE...DR
SHORT TERM...FS
LONG TERM....JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1051 PM MDT SUN APR 1 2012
.UPDATE...
ISSUED AT 1051 PM MDT SUN APR 1 2012
ADJUSTED START TIME OF WIND ADVISORY FOR WESTERN PART OF CWA BASED
ON 00Z GUIDANCE. LOOKS LIKE ADVISORY WINDS SHOULD DEVELOP OVER
THESE LOCATIONS AS EARLY AS 09Z...SPREADING EASTWARD THROUGH
12Z. STRONGEST WINDS ALOFT STILL LOOK TO BE IN THE 12-18Z TIME
PERIOD ACROSS THE AREA. 00Z GFS AND MAV GUIDANCE ARE THE MOST
BULLISH ON DAYTIME WINDS WITH SUSTAINED WINDS WITHIN WARNING
CRITERIA. LATEST NAM/SREF/RUC/HRRR ALL MUCH LESS...WITH WINDS
REMAINING WITHIN ADVISORY LEVELS. WITH THIS IN MIND I DECIDED TO
KEEP ADVISORY RATHER THAN UPGRADING AT THIS TIME.
UPDATE ISSUED AT 846 PM MDT SUN APR 1 2012
MADE FURTHER ADJUSTMENTS TO WIND FORECAST IN THE 06-15Z PERIOD
BASED ON LATEST RUC AND NAM TIMING OF FROPA. 00Z NAM STILL
INDICATING HIGH END ADVISORY/NEAR WARNING CRITERIA WINDS EARLY
MONDAY MORNING OVER EASTERN COLORADO. 00Z NAM AND LATEST SREF AND
RUC ARE LESS BULLISH THAN EARLIER ON WARNING CRITERIA. I HAVE
KEPT ADVISORY IN PLACE FOR NOW...AND WILL PROBABLY WAIT FOR 00Z
GFS TO MAKE FINAL DECISION ON FURTHER ADJUSTMENTS OR POSSIBLE
UPGRADES.
UPDATE ISSUED AT 554 PM MDT SUN APR 1 2012
MADE MINOR CHANGES TO WIND FORECAST TO ACCOUNT FOR WINDS
INCREASING QUICKER OVER WESTERN PARTS OF CWA AFTER 09Z TONIGHT AND
TO BUMP UP WIND GUST WORDING. I ALSO ADDED PATCHY BLOWING
DUST TO WEATHER GRIDS. IM CONCERNED WE COULD SEE WARNING CRITERIA
WINDS OVER WESTERN PARTS OF THE CWA MONDAY MORNING...HOWEVER NOT
A LOT OF NEW DATA TO LOOK AT AND MAKE A DECISION YET. WILL
PROBABLY WAIT UNTIL 00Z DATA COMES IN TO FURTHER FINE TUNE WIND
FORECAST. OTHER CHANGE WAS TO ADJUST TIMING OF PRECIP
MONDAY...TO INCLUDE RAIN SHOWERS MONDAY AFTERNOON IN THE SOUTH AND
WEST. 18Z NAM/GFS BOTH INDICATING AXIS OF FRONTOGENISIS MOVING NORTH
AND EAST ALONG WITH DECENT MID LEVEL MOISTURE IN THE 21-00Z
TIME-FRAME...SO EARLIER ARRIVAL OF RAIN CANT BE RULED OUT.
RED FLAG CONDITIONS CONTINUE OVER MANY LOCATIONS ACROSS THE
AREA...SO I PLAN ON LETTING THE RFW EXPIRE ON TIME AT 02Z.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 238 PM MDT SUN APR 1 2012
SOUTHWEST FLOW WILL BE OVER THE REGION TONIGHT. THE UPPER LOW WILL
MOVE INTO SOUTHWEST NEW MEXICO MONDAY. A SURFACE TROUGH WILL BE OVER
EASTERN COLORADO TONIGHT. A COLD FRONT WILL PUSH SOUTH ACROSS
NORTHWEST KANSAS EARLY MONDAY.
SUBSIDENCE WILL CONTINUE OVER THE FA TONIGHT SO POPS WILL BE NIL.
SOME LIGHT PRECIPITATION WILL BE POSSIBLE MONDAY MORNING OVER
WESTERN PORTIONS OF EASTERN COLORADO WHILE DYNAMICS FROM THE UPPER
LOW ARE STILL REASONABLY CLOSE. BY MONDAY AFTERNOON THE LOW WILL
MOVE FAR ENOUGH SOUTH SO THAT CHANCES ARE MUCH LOWER. PLAN TO
CONTINUE SLIGHT CHANCE POPS IN EASTERN COLORADO MONDAY MORNING AND
THEN SILENT POPS MONDAY AFTERNOON. THE REST OF THE FA WILL HAVE NIL
POPS.
STRONG WINDS ARE THE MAIN FOCUS OF THE FORECAST FOR MONDAY. THE
GFS/NAM BOTH INDICATE GUSTS TO AROUND 50 MPH BETWEEN 12-15Z.
SUSTAINED WIND WILL BE STRONG ENOUGH TO SUPPORT A WIND ADVISORY ALL
DAY. SEE DETAILS ON THE WIND ADVISORY BELOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 238 PM MDT SUN APR 1 2012
MONDAY NIGHT WINDS WILL REMAIN GUSTY THROUGH THE NIGHT...WITH THE
STRONGEST GUSTS DURING THE EVENING...AS THE COOLER TEMPERATURES
ABOVE THE GROUND ALLOW THE STRONG WINDS TO MIX TO THE SURFACE. AS
SUCH HAVE THE WIND ADVISORY EXTENDING INTO THE EVENING. DURING THE
LATE EVENING THE WINDS WILL SLOWLY DECLINE AS THE COOLER
TEMPERATURES AT THE SURFACE CAUSE MIXING TO DECLINE.
THERE STILL REMAINS SOME UNCERTAINTY WITH TRACK OF THE CLOSED UPPER
LEVEL LOW MONDAY NIGHT THROUGH WEDNESDAY. MODELS IN GENERAL HAVE
SLOWED THE SYSTEM DOWN FROM YESTERDAY...WHICH SEEMS REASONABLE SINCE
THE CLOSED LOW WILL BE OUTSIDE OF THE MAIN UPPER LEVEL FLOW. THE
12Z NAM IS FURTHER SOUTH THAN IT WAS AT THIS TIME YESTERDAY WHILE
THE 12Z GFS IS FURTHER NORTH. PREFERENCE IS THE SREF AND NAM SINCE
THEY ARE SLOWER AND HAVE MORE RUN TO RUN CONSISTENCY WITH THE TRACK
OF THE CLOSED LOW AND ARE IN LINE WITH THE MAJORITY OF THE 6Z
GEFS...BUT FAVORED MOSTLY THE SREF FOR DETERMINING AREAS OF PRECIP.
SINCE THE NAM DRASTICALLY CUT BACK THE PRECIP. FOR THIS STORM
SYSTEM. GENERALLY THINKING A SLOWER TREND OF THE PRECIPITATION
MONDAY NIGHT THROUGH TUESDAY EVENING LOOKS TO BE THE WAY TO
GO...WITH LOCATIONS SOUTH OF HIGHWAY 24 LOOKING TO HAVE THE BEST
CHANCE FOR PRECIPITATION UNTIL THE STORM SYSTEM MOVES FURTHER EAST.
MONDAY EVENING HAVE SLIGHT CHANCES FOR PRECIPITATION OVER EASTERN
COLORADO AS THE 750-650MB SATURATES WITH ISENTROPIC LIFT OVER THAT
AREA. OVERNIGHT PRECIP. CHANCES INCREASE OVER THE ENTIRE AREA FROM
SOUTHWEST TO NORTHEAST AS ISENTROPIC LIFT OVERSPREADS THE AREA AND
MOISTURE AHEAD OF THE CLOSED LOW BEGINS TO MOVE NORTH INTO THE
AREA. SOME LOCATIONS IN EASTERN COLORADO MAY RECEIVE SOME SNOW WITH
LOW TEMPERATURES AROUND FREEZING.
TUESDAY PRECIP. CHANCES SLOWLY INCREASE AS THE CIRCULATION OF THE
CLOSED LOW CONTINUES TO BRING MOISTURE INTO THE AREA. BIGGEST
QUESTION IS HOW FAR NORTH THE MOISTURE WILL MAKE IT AS THE CLOSED
LOW MOVES EAST. WITH MORE UNCERTAINTY THAT THERE WILL BE MOISTURE
FOR THE ISENTROPIC LIFT TO WORK WITH AS ONE MOVES NORTH...HAVE
PRECIP. CHANCES DECREASING TO THE NORTH. WINDS WILL CONTINUE TO
DECREASE AS THE UPPER LEVEL WINDS DECLINE...BECOMING LIGHT BY
EVENING.
TUESDAY NIGHT PRECIPITATION CHANCES BEGIN TO DECREASE FROM EAST TO
WEST AS THE CLOSED LOW AND WRAP AROUND MOISTURE MOVE EAST.
FOR WEDNESDAY THROUGH SUNDAY THE MAIN FOCUS WILL BE THE CLOSED LOW
MOVING OUT OF THE AREA AND THUNDERSTORM CHANCES TOWARD THE END OF
THE WEEK.
WEDNESDAY THE CLOSED CONTINUES TO MOVE OUT OF THE AREA. BOTH THE
GFS AND ECMWF HAVE THE CLOSED LOW MOVING EAST OVER KANSAS...WHILE
THE NAM/SREF HAVE THE CLOSED LOW MOVING EAST OVER OKLAHOMA. DESPITE
THE DIFFERING POSITIONS OF THE LOW...THE MODELS AGREE THAT PRECIP.
CHANCES WILL DECLINE FROM EAST TO WEST DURING THE DAY AS THE CLOSED
LOW MOVES EAST. BEHIND THE CLOSED LOW A SHORT WAVE RIDGE MOVES OVER
THE AREA.
THURSDAY THE NEXT UPPER LEVEL TROUGH MOVES ON SHORE. BY FRIDAY
MORNING THE TROUGH WILL BE OVER THE INTER MOUNTAIN WEST. AT THE
SURFACE A LEE SIDE TROUGH DEVELOPS OVER EASTERN COLORADO AS THE
UPPER LEVEL TROUGH APPROACHES THE TRI-STATE AREA. FRIDAY SOUTHERLY
AHEAD OF AN UPPER LEVEL SHORT WAVE TROUGH BRING UP MOISTURE FROM
THE SOUTH. WITH INSTABILITY TO WORK WITH CANNOT RULE OUT A FEW
THUNDERSTORMS FROM FORMING OVER THE EASTERN PART OF THE AREA DURING
THE AFTERNOON. FRIDAY NIGHT A COLD FRONT MOVES THROUGH THE AREA.
OVER THE EAST THUNDERSTORM CHANCES CONTINUE WITH ELEVATED INSTABILITY
IN PLACE AND THE LOW LEVEL JET MOVING OVER THOSE AREAS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 531 PM MDT SUN APR 1 2012
VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE
PERIOD...HOWEVER...THERE IS A CHANCE FOR MVFR CIGS VERY LATE IN THE
PERIOD. HAVE HELD OFF ON MENTIONING AT THIS TIME AND WILL LET
SUBSEQUENT SHIFTS ANALYZE THIS. OTHERWISE...A COLD FRONT WILL PUSH
THROUGH THE AREA DURING THE MORNING HOURS. WINDS WILL SWITCH TO
THE NORTH AND BECOME WINDY WITH GUSTS IN THE 40 KNOT RANGE
LIKELY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY FROM 3 AM TO 9 PM MDT MONDAY FOR COZ090>092.
KS...WIND ADVISORY FROM 3 AM MDT /4 AM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR KSZ001-013-027.
WIND ADVISORY FROM 6 AM MDT /7 AM CDT/ TO 9 PM MDT /10 PM CDT/
MONDAY FOR KSZ002>004-014>016-028-029-041-042.
NE...WIND ADVISORY FROM 3 AM TO 9 PM MDT MONDAY FOR NEZ079.
WIND ADVISORY FROM 7 AM TO 10 PM CDT MONDAY FOR NEZ080-081.
&&
$$
UPDATE...DR
SHORT TERM...FS
LONG TERM....JTL
AVIATION...BAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
141 AM EDT MON APR 2 2012
.UPDATE...
ISSUED AT 945 PM EDT SUN APR 1 2012
A NARROW LINE OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED NORTH OF A
LINE FROM INDIANAPOLIS TO DAYTON OVER THE PAST FEW HOURS. THIS IS
MOST LIKELY TH LINE OF SHOWERS AND STORMS THAT THE HRRR HAS BEEN
PICKING UP ON. THUS...THIS IS THE LINE THAT IS MOST LIKELY TO AFFECT
US TONIGHT. BASED ON THE MOVEMENT AND SPEED OF THIS LINE...IT WILL
NOT MAKE IT INTO THE BLUEGRASS UNTIL 3 OR 4 AM AT THE EARLIEST. WITH
THE SURFACE ALREADY DECOUPLING UNDER CLEAR SKIES...WIND THREAT FROM
ANY OF THESE STORMS APPEARS VERY MARGINAL AT BEST. ANY THREAT WILL
LIKELY COME FROM LARGE HAIL...AND EVEN THIS IS QUESTIONABLE.
THUS...SEVERE THREAT LOOKS MUCH MORE MARGINAL NOW...BUT STILL CANNOT
BE RULED OUT. HAVE TRIMMED BACK POPS ACROSS THE SOUTHWEST A BIT MORE
AS IT APPEARS MOST LIKELY TO AFFECT THE NORTHEASTERN TWO THIRDS OF
THE FORECAST AREA. KEPT SOME POPS AROUND DURING THE MORNING ACROSS
THE SOUTHEAST AS WE COULD HAVE SOME BACKBUILDING ALONG THIS LINE OF
SHOWERS AND STORMS. OTHERWISE...THE ACTIVITY SHOULD COME TO AN END
THERE BY MIDDAY...WITH THE AFTERNOON TURNING DRIER.
UPDATE ISSUED AT 738 PM EDT SUN APR 1 2012
AFTER A CLOUDY DAY WITH SOME RAIN SHOWERS...SKIES HAVE CLEARED OUT
ACROSS EASTERN KENTUCKY THIS EVENING. IN ACCORDANCE...HAVE ALTERED
THE FORECAST TO REFLECT MORE CLEAR SKIES OVER THE NEXT SEVERAL HOURS.
HOWEVER...SHOWERS AND A FEW STORMS ARE ALREADY BEGINNING TO DEVELOP
TO THE NORTH FROM JUST NORTHWEST OF INDIANAPOLIS TO JUST NORTH OF
WILMINGTON OHIO. THE HRRR SHOWS THIS ACTIVITY PUSHING SOUTH INTO OUR
NORTHERN AREAS CLOSE TO MIDNIGHT. IT LOOKS INCREASINGLY LIKELY ONLY
THE EASTERN COUNTIES WILL STAND THE BEST CHANCE OF RAIN TONIGHT...SO
HAVE REMOVED POPS FROM OUR SOUTHWEST ZONES. OTHERWISE...MADE SOME
MINOR ADJUSTMENT TO TEMPERATURES AND WINDS.
UPDATE ISSUED AT 526 PM EDT SUN APR 1 2012
LAST OF THE MCS IS FINALLY DEPARTING OFF TO OUR SOUTHEAST...WITH
SKIES QUICKLY CLEARING ACROSS THE AREA THIS EVENING. THIS SHOULD
ALLOW FOR MOST PLACES TO REACH THEIR HIGH FOR THE DAY OVER THE NEXT
HOUR OR TWO AS TEMPERATURES QUICKLY SHOOT UP WITH THE SUNSHINE. WITH
STABLE AREA ENTRENCHED ACROSS EASTERN KENTUCKY STRETCHING NORTH INTO
SOUTHERN OHIO...ANY DEVELOPING MCS WILL BE AT LEAST 3 TO 6 HOURS
BEFORE IT IMPACTS OUR NECK OF THE WOODS. WITH THIS IN MIND...HAVE
GONE AHEAD AND DELAYED THE BETTER PRECIPITATION CHANCES UNTIL AFTER
04Z (MIDNIGHT). THE HRRR SEEMS TO HAVE THE BEST TIMING AND HANDLING
ON THE SITUATION WITH ALL OTHER MODELS TO AGGRESSIVE ON REDEVELOPING
ACTIVITY IN THE STABLE BOUNDARY LAYER OVER THE NEXT FEW HOURS. NO
INDICATION THIS WILL HAPPEN AS CLOUDS ARE FEW AND FAR BETWEEN.
THUS...THE HRRR INDICATION OF LATER CONVECTION SEEMS LIKE THE WAY TO
GO UNTIL SOMETHING SHOWS ME OTHERWISE. STILL GOING TO BE MAINLY A
HAIL THREAT...ESPECIALLY GIVEN MOST OF THE ACTIVITY SHOULD BE
ELEVATED. WILL CONTINUE TO MONITOR FOR ADDITIONAL UPDATES AS EVENTS
UNFOLD OVER THE NEXT 3 TO 6 HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 359 PM EDT SUN APR 1 2012
THE LEFTOVER MCS IS FINALLY MAKING AN EXIT ACROSS THE AREA...WITH
THE BACK EDGE LIKELY TO EXIT BETWEEN 4 AND 5 PM. HIGHS HAVE REALLY
BEEN HAMPERED BY THE CLOUD COVER...BUT DO EXPECT A LATE IN THE DAY
PUSH...WITH SOME LOW TO MID 70S FOUND WEST OF I-75...WHILE MOST
OTHERS RANGE FROM THE MIDDLE 60S TO AROUND 70 DEGREES.
THE MODELS CONTINUE TO PLAY UP ANOTHER THUNDERSTORM COMPLEX TO
DEVELOP ACROSS THE UPPER OHIO BASIN LATER THIS EVENING IN RESPONSE TO
A DIGGING SHORT WAVE TROUGH WHICH WILL NOSE IN FROM THE SAINT
LAWRENCE RIVER VALLEY OVERNIGHT. THE MODEL TIMING OF THIS ACTIVITY IF
IT DOES HAPPEN...SEEMS A BIT FAST...AS THERE IS NOTHING POPPING YET
IN NORTHERN OHIO. WILL CONTINUE TO ALLOW FOR SOME GOOD CHANCE POPS
LATER TONIGHT FOR THE NORTHEAST HALF OF THE AREA...SCALING BACK
QUICKLY TO SLIGHT CHANCE TO THE SOUTHWEST.
AS FOR THE SEVERE THREAT...HAVE EVEN LESS CONFIDENCE IN THIS...AS WE
HAVE BEEN STABILIZED BY THE STORMS THAT TOOK PLACE THIS AFTERNOON.
WILL HAVE TO WAIT AND SEE HOW THE ATMOSPHERE RECOVERS TONIGHT...WITH
AT LEAST LIGHT SOUTHWEST WINDS ADVECTING SOME LOW LEVEL
MOISTURE...WHICH MAY RECHARGE US SOMEWHAT.
THIS COMPLEX...WILL HELP DRAG A BACKDOOR COOL FRONT THROUGH THE AREA
DURING THE DAY TOMORROW. BESIDES SOME LEFTOVER CONVECTION IN THE
MORNING...DO NOT EXPECT ANY RE-FIRING LATER IN THE DAY...WITH THE
MODEL SOUNDINGS SHOWING SOME DECENT CAPPING. THE FRONT WILL THEN MOVE
BACK TO THE NORTHEAST MONDAY NIGHT AS A WARM FRONT...PERHAPS KICKING
OFF SOME ISOLATED CONVECTION AS THIS OCCURS.
AS FOR TEMPERATURES...ABOVE NORMAL READINGS WILL CONTINUE...ALTHOUGH
READINGS HAVE COME IN A BIT COOLER FOR MONDAY WITH A LITTLE MORE
COOLER AND DRIER AIR INTRUSION...SO 70S WILL MOST LIKELY BE THE RULE
FOR MOST LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 359 PM EDT SUN APR 1 2012
A RATHER COMPLEX AND SOMEWHAT PROGRESSIVE PATTERN IS ANTICIPATED
DURING THE LONG TERM PERIOD. MOST OF THE TIME THE MAIN BAND OF
WESTERLIES ARE EXPECTED TO RESIDE TO OUR WEST...NORTH OR NORTHEAST
WITH UPPER LEVEL RIDGING POSSIBLY DOMINATING DURING TWO DISTINCT
PERIODS...WITH THE HIGHEST CHANCE OF THIS LATE IN THE PERIOD.
OVERALL...MODELS ARE IN REASONABLY GOOD AGREEMENT WITH THE PATTERN
WITH SOME DIFFERENCES LATER IN THE PERIOD AND SOME TIMING
DIFFERENCES FROM INDIVIDUAL MODEL RUN TO MODEL RUN.
EARLY ON...A WARM FRONT WILL BE MOVING NORTHEAST AND POSSIBLY EXIT
NORTHEAST OF THE AREA BY TUESDAY AFTERNOON OR EVENING. MODELS
GENERALLY DEVELOP PRECIP ONLY OVER THE EASTERN HALF OF THE CWA EARLY
IN THE PERIOD...WITH A POSSIBLE PERIOD OF SHORTWAVE RIDGING/DRY
SLOTTING OCCURRING BEFORE A COLD FRONT APPROACHES LATE IN THE DAY OR
TUE NIGHT.
THIS COLD FRONT WILL DROP SLOWLY SOUTH FROM TUE NIGHT INTO
WED...WITH THE MODEL CONSENSUS TAKING THE BOUNDARY SOUTH OF THE CWA
BY WED EVENING. HOWEVER...THE BOUNDARY SHOULD THEN STALL FOR A
TIME...THOUGH THE MODELS VARY IN HOW LONG DUE TO DIFFERENCES IN
HANDLING AN UPPER LOW THAT WILL MEANDER SOUTH OF A NORTHERN
PLAINS/NORTHERN GREAT LAKES RIDGE FROM THE SOUTHERN ROCKIES ACROSS
THE PLAINS AND MS VALLEY AND ON INTO THE EASTERN CONUS...POSSIBLY
ACROSS THE TN VALLEY AND INTO THE SOUTHERN APPALACHIANS AND THEN OFF
THE EASTERN SEABOARD. THIS UPPER LOW IS EXPECTED TO FOLLOW THIS
MEANDERING PATH FROM THE START OF THE PERIOD ON TUE THROUGH FRI.
AS MENTIONED BY THE PREVIOUS FORECASTER....BUT FRI IT SHOULD FINALLY
GET PICKED UP BY A TROUGH TO ITS NORTHEAST AND THIS SHOULD THEN TAKE
IT OUT TO SEA. THEREAFTER...THE MODEL CONSENSUS IS FOR THE UPPER
LEVEL RIDGE TO BUILD IN AND DOMINATE THAT LAST TWO TO TWO AND A HALF
DAYS OF THE PERIOD.
AS FOR POPS...WENT WITH SLIGHT CHANCE TO CHANCE POPS EARLY ON TUE
WITH THE WARM FRONT AND THEN INCREASED POPS LATE ON TUE INTO TUE
EVENING IN ADVANCE OF THE APPROACHING COLD FRONT AND SHORTWAVE THAT
THE MODEL CONSENSUS TAKES ACROSS THE OH VALLEY REGION OR THE CWA ON
TUE NIGHT. THE BOUNDARY SHOULD CONTINUE SLIPPING SOUTH ON WED AND
CONTINUED CHANCE POPS DURING WED...BUT GRADUALLY LOWERED POPS IN THE
NORTH FARTHER AWAY FROM THE BOUNDARY. A SFC LOW MAY DEVELOP ALONG
THE BOUNDARY AS THE UPPER LOW APPROACHES AROUND MIDWEEK AND SLOW THE
SOUTHWARD PROGRESS OF THE FRONT AND HOLD IN CHANCES FOR ISOLATED TO
SCATTERED CONVECTION AS THE SFC LOW AND UPPER SYSTEM PROBABLY TRACK
JUST TO OUR SOUTH ACROSS THE TN VALLEYS. ONCE THE UPPER SYSTEM
TRACKS EAST...PRECIP CHANCES WILL DIMINISH LATE THU NIGHT OR FRI.
FOR NOW THE END OF THE FORECAST IS EXPECTED TO BE DRY...WITH UPPER
LEVEL RIDGING DOMINATING. WITH THIS RIDGE...OPTED TO FAVOR THE ECMWF
RUNS.
TEMPERATURES SHOULD BE WARMEST AND MOST ABOVE NORMAL ON TUESDAY AND THEN
MORE MODEST DEPARTURES OF ABOUT 5 DEGREES ABOVE NORMAL AT THE END OF
THE PERIOD. OVERNIGHT LOWS SHOULD AVERAGE AT LEAST 5 DEGREES ABOVE
NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1 AM EDT MON APR 2 2012
VFR CONDITIONS NOTED AT ISSUANCE WITH A LINE OF CONVECTION DROPPING
SOUTH INTO NERN KY. AREAS NORTH AND EAST OF A LINE FROM KI39 THRU
KJKL TO KPBX WILL HAVE THE BEST CHANCE OF SEEING PRECIP...HOWEVER
CIGS ARE GENERALLY EXPECTED TO REMAIN LOW END VFR THRU THE REMAINDER
OF THE OVERNIGHT. FOG WILL BE POSSIBLE AGAIN AND HAVE TRENDED A
LITTLE MORE FOR LOZ AND SME. LLWS WILL ALSO BE A FACTOR OVERNIGHT
WITH A -KT LOW LEVEL JET OVERHEAD AND LIGHT TO CALM SFC WINDS. SHRA
WILL SLIDE OFF TO THE EAST AS FOG DISSIPATES SHORTLY AFTER
SUNRISE...BUT LOW CIGS MY LINGER THRU THE MORNING AROUND M/VFR
THRESHOLDS. WINDS ARE EXPECTED TO PICK UP AGAIN DURING THE MORNING
WITH A NE COMPONENT AT THE SFC UP THRU ABOUT 3 KFT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
$$
UPDATE...KAS
SHORT TERM...GEOGERIAN
LONG TERM....JP
AVIATION...MB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
515 AM EDT MON APR 2 2012
.SYNOPSIS...
ISSUED AT 515 AM EDT MON APR 2 2012
UPPER RIDGE BUILDS INTO THE AREA TODAY BUT MOISTURE ADVECTION AT
H85/H7 IS ALREADY SPAWNING SHRA/TSRA FM NORTHERN MN INTO NW WI AND
TOWARD FAR WESTERN UPR MI. WILL HAVE TO CONTEND WITH AT LEAST ISOLD
SHRA/TSRA TODAY MAINLY OVR WEST THIRD OF CWA. BETTER CHANCE FOR RAIN
ARRIVES LATER TONIGHT AS SFC LOW AND INVERTED TROUGH SLIDE ACROSS
UPR MI. SOME RAIN LINGERS ON TUESDAY MORNING BUT AFTER THAT DRY
WEATHER DOMINATES THE REST OF THE WEEK AS HIGH PRESSURE EXPANDS FM
HUDSON BAY ACROSS THE GREAT LAKES REGION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
TODAY...UPPER RIDGE CONTINUES TO BUILD FM THE PLAINS INTO THE
WESTERN GREAT LAKES THROUGH THE DAY WHILE AT THE SFC...HIGH OVR
HUDSON BAY WILL EXPAND A RIDGE AXIS ACROSS MUCH OF MICHIGAN. AT
FIRST GLANCE...DOES NOT APPEAR TO BE A FAVORABLE SETUP FOR MUCH
PRECIPITATION TODAY OVR UPR MI...BUT CERTAINLY CANNOT IGNORE
CLUSTER OF SHRA/TSRA THAT HAVE FORMED OVR NORTHERN MN INTO
NORTHWEST WI THE LAST FEW HOURS. SHRA/TSRA SEEM TO BE RUNNING ALONG
AND NORTH OF RIBBON OF HIGHER H7 DWPNTS AND ON NORTHERN EDGE OF
STEEPER H7-H5 LAPSE RATES FM MN INTO WI. ONLY 00Z GUIDANCE THAT
SHOWED TSRA AS FAR EAST AS IS CURRENTLY OCCURRING WAS HRRR. ALL
OTHER GUIDANCE KEPT GENESIS REGION FOR SHRA/TSRA OVR WESTERN MN
WHERE BETTER H85 THETA-E ADVECTION IS TAKING PLACE.
FOLLOWING RUC13/NAM H7 DWPNTS/WINDS SUGGESTS THAT AT LEAST ISOLD
TSRA WILL EASE INTO WESTERN THIRD OF CWA THIS MORNING BEFORE FADING
AWAY AS RIBBON OF HIGHER H7 DWPNT WEAKENS. WILL KEEP POPS IN OVR
WEST ALL DAY THOUGH AS RUC INDICATES HINT OF H7 MOISTURE AXIS COULD
PERSIST INTO EARLY AFTN. DESPITE RESERVOIR OF H7-H5 LAPSE RATES AOA
8C/KM UPSTREAM...MINIMAL LARGE SCALE FORCING AND MARGINAL 3-6KM
SHEAR /20KT OR SO/ SHOULD LEAD TO ONLY SLIM CHANCES OF SEEING
HAIL WITH THESE STORMS. WILL NEED TO MONITOR TRENDS THIS MORNING
THOUGH. BY LATE AFTN...EXPECT MAIN AREA OF SHRA/TSRA WEST OF UPR
MI IN AREA OF GREATEST H85 TEMP/MOISTURE ADVECTION.
OTHER ISSUE TODAY ESPECIALLY THIS MORNING IS FOG. FOR THE MOST PART
THE FOG IS OVR HIGHER TERRAIN OF NCNTRL CWA AND HIGHER TERRAIN OF
KEWEENAW. EVEN IN THESE AREAS MAIN IMPACT IS MORE OF STRATUS DECK
WITH VARIABLE VSBY. EXPECT DRY ADVECTION OVR EASTERN UPR MI TO
SPREAD EAST AND DIMINISH THE FOG BY MID MORNING /AS ALREADY HAS
OCCURRED AT ERY EARLY THIS MORNING/. COVERAGE OF CLOUDS /LOWER AND
MID/ BY MID AFTN COULD BE CHAOTIC WHICH WILL NO-DOUBT IMPACT HIGH
TEMPS. SE GRADIENT WIND OFF THE LAKES SHOULD KEEP TEMPS IN CHECK
EVEN IF DECENT AMOUNT OF SUNSHINE ENDS UP OCCURRING. EXPECT HIGHS TO
MAINLY TOP OUT IN THE 50S...COOLER NCNTRL WITH UPSLOPE FLOW. GIVEN
ENOUGH SUNSHINE SOME SPOTS MAY PUSH PAST 60 DEGREES...BUT NOT TOO
MUCH HIGHER.
TONIGHT...UPR RIDGE REMAINS IN TACT TO START THE EVENING THEN
OVERNIGHT NORTHERN STREAM SHORTWAVE MOVES FM MANITOBA INTO
NORTHWEST ONTARIO. AS THIS TROUGH APPROACHES...SFC LOW OVR THE
PLAINS WILL LIFT INTO WESTERN GREAT LAKES WITH INVERTED SFC TROUGH
AND H85 TROUGH SLIDING WEST TO EAST ACROSS UPR MI. MODELS HAVE
TRENDED A BIT SLOWER WITH ARRIVAL OF UPR AND SFC TROUGH. PREVIOUS
FCST HAD GOOD HANDLE ON TREND WITH HIGHER POPS OVERNIGHT. WHAT TO DO
WITH POP COVERAGE IS MAIN ISSUE. BASED ON EXPECTED LARGE SCALE
PATTERN AND FCST LOCATION OF HIGHER MUCAPE...WOULD FIGURE THAT
HIGHEST POPS WOULD BE OVER LK SUPERIOR AND MAINLY TO SOUTH OF CWA.
THOUGH CONVERGENCE FM INVERTED SFC TROUGH INTERSECTING S/SW FLOW AT
H85 /DPWNTS AOA +10C/ SUPPORTS HIGHER POPS OVR CWA AS WELL. KEPT
POPS HIGH CHANCE TO LIKELY AS THE INVERTED TROUGH SLIDES THROUGH CWA.
TSRA CHANCES SEEM MINIMAL BASED ON MAIN MUCAPE STAYING OVR WI AND
850-300MB THICKNESSES ORIENTED WNW TO ESE. HOWEVER...IF CONVECTION
MAINLY FIRES ON FAR NORTH EDGE OF HIGHER INSTABILITY /AS OCCURRED
THIS MORNING/ THEN IT IS FEASIBLE THERE COULD BE COMPLEX OF TSRA
AFFECTING PORTIONS OF CWA OVERNIGHT TONGIHT INTO EARLY TUESDAY
MORNING. LIKELY WILL NOT KNOW IF THIS IS THE CASE UNTIL MAYBE LATE
THIS EVENING OR OVERNIGHT TONIGHT.
TUESDAY...SLOWER TREND OF TROUGH PASSAGE CONTINUES TO SHOW UP INTO
TUESDAY AND HAVE DELAYED DIMINISHING POPS UNTIL EARLY TUESDAY AFTN.
AT THIS POINT /COULD BE FURTHER SLOWER TREND/ HIGHEST POPS ON
TUESDAY WILL BE THROUGH ROUGHLY 16Z /NOON EDT/ OVR EASTERN HALF OF
CWA MAINLY TO EAST OF MARQUETTE AND IRON MOUNTAIN. KEPT SMALL
CHANCES FOR TSRA IN PICTURE ALONG LK MICHIGAN IN THE MORNING UNTIL
H85 WINDS VEER WEST PUSHING THE HIGHER H85 DWPNTS/INSTABILITY TO
SOUTHEAST OF CWA. WINDS TURNING NORTH BEHIND THE TROUGH SHOULD KEEP
CLOUDS IN OVR MUCH CWA THROUGH MUCH OF AFTN. DECREASING CLOUDS
EXPECTED LATE AFTN THOUGH PER MODEL CONSENSUS OF RAPIDLY LOWERING
DWPNTS AT H85 AND PER FCST SOUNDINGS. POSSIBLE THAT SOME LOW CLOUDS
AND/OR FOG MAY TRY TO ADVECT ONSHORE SIMILAR TO WHAT OCCURRED SUNDAY
AFTN. LATER SHIFTS CAN ADDRESS THIS IN MORE DETAIL AND ADD IF IT
SEEMS REASONABLE. LOWERED TEMPS ESPECIALLY IN THE NORTH CWA DUE TO
LATER DEPARTURE OF PCPN AND CLOUDS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
HIGH PRESSURE SLIDING IN TUESDAY EVENING FROM MANITOBA AND EASTERN
ND/WESTERN MN WILL BRING ABOUT A PROLONGED PERIOD OF DRY WEATHER.
EXPECT THE HIGH TO PUSH OVER THE UPPER GREAT LAKES WEDNESDAY
AFTERNOON...BEFORE STRENGTHENING ACROSS THE AREA THROUGH FRIDAY.
GIVEN A SLIGHTLY SLOWER SOLUTION AND A LINGERING 500MB TROUGH
OVERHEAD THROUGH WEDNESDAY EVENING...WILL KEEP WITH LINGERING CLOUDS
EAST INITIALLY TUESDAY NIGHT...AND AFTERNOON CLOUDS DEVELOPING NEAR
900MB POSSIBLE CENTRAL AND EAST. EXPECT ONLY LIMITED CLOUDS AT THIS
TIME GIVEN OUR DRY ATMOSPHERE WITH PW VALUES ABOUT 60 PERCENT OF
NORMAL AROUND 0.26IN.
LOWERED DEW POINTS A COUPLE OF DEGREES FOR WEDNESDAY
AFTERNOON...MAINLY INTERIOR WEST...WITH RH VALUES ACROSS THIS AREA
BOTTOMING OUT AROUND 25 TO 30 PERCENT. WITH NO SIGNIFICANT INFLUX OF
MOISTURE...RH VALUES SHOULD FALL BETWEEN 25 AND 35 PERCENT THROUGH
FRIDAY /ONCE AGAIN MAINLY ACROSS THE INTERIOR WEST HALF/.
LOW PRESSURE DEVELOPING OFF THE NORTHERN ROCKIES MID WEEK SHOULD
PUSH ACROSS THE PLAINS STATES FRIDAY NIGHT...BEFORE SLIDING
DEEPENING TO OUR WEST SATURDAY...AND PUSHING UP AND ACROSS ONTARIO
SATURDAY NIGHT INTO SUNDAY. THE FORECAST MODELS LOOK TO BE IN FAIRLY
GOOD AGREEMENT UNTIL THE FOCUS SHIFTS TO THE NEARING LOW SATURDAY
AFTERNOON. AFTER SATURDAY...I HAVE ONLY MODERATE CONFIDENCE IN THE
ONGOING FORECAST /MAINLY WITH RESPECT TO TIMING AND PRECIPITATION
TYPE AS THE LOW EXITS/.
AFTERNOON TS SATURDAY MAY LINGER INTO SATURDAY NIGHT EAST. WHILE THE
QUICKER 01/12Z RUN OF THE ECMWF WOULD HAVE THEM OUT OF ERY BY 06Z
SUNDAY. WILL TAKE OUT ANY MENTION OF WRAP AROUND SHSN SUNDAY...BUT
IT MAY NEED TO BE ADDED BACK IN IF THE ECMWF VERIFIES WITH 850MB
TEMPS FALLING TO AROUND -3 OR -4C BY EARLY AFTERNOON WEST AND
CENTRAL. INSTEAD OF RUNNING A NON-DIURNAL TEMP TRACE FOR
SUNDAY...KEPT WITH TRADITIONAL RISING TEMPS DURING THE DAY /SIMILAR
TO THE GFS/. AS NOTED...THIS WILL LIKELY BE REVISED MORE THAN A FEW
TIMES BEFORE OVER THE NEXT FEW DAYS AS FCST MODELS MERGE ON A
SOLUTION...SO WILL NOT GET TOO SPECIFIC AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 147 AM EDT MON APR 2 2012
ALTHOUGH DRIER AIR IS ADVECTING THRU UPR MI IN THE STEADY E WIND ON
THE SRN FLANK OF HI PRES IN ONTARIO...LINGERING POCKETS OF LO CLDS
OVER ERN UPR MI WARRANT HOLDING ON TO A MENTION OF AT LEAST TEMPO
IFR CIGS THRU SUNRISE AT CMX/SAW...WHERE THE WIND WL HAVE AN UPSLOPE
COMPONENT. WITH A DOWNSLOPE COMPONENT AT IWD...EXPECT ANY LO CLD TO
BREAK UP BEFORE REACHING THAT SITE. WILL HAVE TO WATCH FOR POSSIBLE
ISOLD THUNDERSTORMS CURRENTLY NEAR DLH REACHING INTO IWD BTWN NOW
AND DAYBREAK. WITH THE ONSET OF DAYTIME HEATING...VFR CONDITIONS
SHOULD PREVAIL AFTER ANY LINGERING LO CLDS DISAPPEAR SOON AFTER
SUNRISE. SOME SHRA IN ADVANCE OF A LO PRES TROF APPROACHING FM THE W
MAY IMPACT IWD/CMX LATE THIS AFTN INTO THIS EVNG...BUT LINGERING DRY
AIR IN THE LLVLS INDICATE VFR CONDITIONS SHOULD PERSIST THRU 06Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON APR 2 2012
WINDS SHOULD REMAIN BELOW 30KTS THROUGH AT LEAST FRIDAY. AN EXITING
RIDGE OVER LAKE HURON WILL DRIFT ACROSS THE LOWER GREAT LAKES TODAY.
IN ITS PLACE...A TROUGH WILL SLIDE IN FOR LATE TONIGHT INTO TUESDAY
MORNING. EXPECT A HIGH OVER THE NORTHERN PLAINS AND CENTRAL CANADA
TUESDAY TO SLOWLY SLIDE OVER LS WEDNESDAY...WHERE IT SHOULD REMAIN
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLA
SHORT TERM...JLA
LONG TERM...KF
AVIATION...KC/JLA
MARINE...KF
AREA FORECAST DISCUSSION
NWS DULUTH MN
331 AM CDT MON APR 2 2012
.SHORT TERM...RUC ANALYSIS DOING GOOD JOB HIGHLIGHTING GENESIS
REGION OF CONVECTION THIS MORNING OVER WCTRL MN. MID LVL
INSTABILITY AXIS IS ALIGNED EAST ACROSS CWA FROM CASS LAKE TO TWIN
PORTS AND THEN SE TO NRN PRICE COUNTY. CONVECTION HAS TRAINED
ALONG THIS CORRIDOR WITH SMALL HAIL REPORTED AT TIMES. A
SECONDARY 70H THETAE MAX IS DEVELOPING ACROSS SRN KOOCH/NRN ITASCA
VICINITY AND NEW CONVECTION IS FORMING THERE AS WELL. AREA REMAINS
UNDER MID LVL RIDGE AXIS WITH A WEAK SHORTWAVE TROF LIFTING OVER
RIDGE AXIS.
TODAY...USED RUC AS SHORT TERM GUIDANCE FOR PLACING HIGHER POPS
ALONG AFOREMENTIONED INSTABILITY AXIS AS IT MOVES GRADUALLY NORTH
THIS MORNING. BY MIDDAY FOCUS OF CONVECTION MAY BE ALIGNED FROM
NWRN CWA TO NR ST LOUIS COUNTY AND THEN SE TO ERN WISC ZONES.
SMALL HAIL STILL POSSIBLE WITH SOME STORMS. AT THAT TIME... 85H
MSTR TRANSPORT AXIS IS FCST TO STRETCH FROM ST CROIX VALLEY TO
KOOCH COUNTY. WARM ADVECTION AT MID LVLS WILL TEND TO INHIBIT MOST
OF THE ACTIVITY ACROSS THE SRN CWA BY 18Z. WE SHOULD SEE A WELL
DEVELOPED BAND OF RAIN/THUNDERSTORMS FROM SE NDAK INTO NWRN MN.
THIS WILL BE OCCURRING ON NWRN SIDE OF SFC LOW IN AN AREA OF
DIVERGENCE ALOFT SUPPLIED BY RIGHT ENTRANCE REGION OF UPPER
JET.THIS CORRIDOR OF DEEP LAYER LIFT WILL TEND TO REMAIN OVER THE
SAME REGION THROUGH THE AFTERNOON. SIGNIFICANT RAINFALL MAY OCCUR
AND WE WILL NEED TO WATCH KOOCH/NWRN ITASCA COUNTY AREA FOR
ADDITIONAL UPDATES.
TONIGHT/TOMORROW...NRN BRANCH OF WESTERLIES WILL ADVANCE ACROSS CWA
OVERNIGHT. THIS WILL PUSH FRNTL SYSTEM THROUGH AS SFC HIGH BUILDS
INTO CWA FROM NRN PLAINS. DEEP LAYER DRYING REFLECTED IN
INTEGRATED RH PRODUCTS AND MDL XSECTS. SHOULD SEE MOSTLY SUNNY
SKIES ADVANCING ACROSS CWA AS DAY UNFOLDS. WITH INCREASED MIXING
DURING DAY...UNIDIRECTIONAL FLOW IN LOWEST 5K FT....SHOULD SEE
SOME GUSTY WINDS DEVELOPING. SFC DEWPOINTS MAY NEED LOWERING AS
MIX DOWN OF DRIER AIR OCCURS IN AFTN.
.EXTENDED...TUESDAY NIGHT THROUGH SUNDAY...
UPPER LEVEL AND SFC RIDGING WILL COVER THE FA TUESDAY NIGHT THROUGH
FRIDAY. THE RIDGING MOVES JUST E OF THE AREA FRIDAY AFTERNOON
ALLOWING FOR A SOUTHERLY WAA/RETURN FLOW PATTERN TO BECOME
ESTABLISHED. A SHORT WAVE TROF WILL MOVE FROM THE NORTHERN PLAINS
FRIDAY NIGHT INTO THE GREAT LAKES SATURDAY NIGHT. IN THE
MEANTIME...AN ASSOCIATED SFC LOW MOVING THROUGH SOUTHERN CANADA WILL
PUSH A COLD FRONT THROUGH THE FA AND EXIT SATURDAY NIGHT. THIS
COMBINATION WARRANTS SOME POPS FRIDAY NIGHT THROUGH SUNDAY. BEST
INSTABILITY WILL BE FOUND OVER THE SOUTHERN THIRD OF THE AREA
SATURDAY AND HAVE A MENTION OF THUNDERSTORMS.
AVIATION...06Z TAFS
IFR/MVFR CEILINGS WILL OCCUR IN SPOTS THROUGH THE PERIOD...MOST LIKELY
AROUND LAKE SUPERIOR. SOME FOG WILL ALSO BE POSSIBLE...ALTHOUGH
SB`S HAVE INCREASED IN MOST AREAS DUE TO STRONG HIGH BUILDING
SOUTH THROUGH ONTARIO.
SHOWERS/STORMS WERE DEVELOPING JUST WEST OF KDLH...ON WEST TO NEAR
KDTL. PERSISTENT WAA/MOISTURE TRANSPORT SHOULD LEAD TO ADDITIONAL
SHOWER/STORM DEVELOPMENT OVERNIGHT INTO MONDAY. MVFR OR EVEN SOME
IFR CONDITIONS WILL BE POSSIBLE WITH ANY SHOWERS/STORMS. STORMS
SHOULD OCCUR MAINLY OVER NORTHEAST/NORTHERN MINNESOTA THROUGH
MUCH OF MONDAY...TRANSLATING EAST MONDAY NIGHT.
.POINT TEMPS/POPS...
DLH 52 40 58 35 / 60 60 10 0
INL 51 36 58 30 / 60 60 10 0
BRD 63 41 61 34 / 50 60 10 0
HYR 62 42 61 33 / 20 60 20 0
ASX 57 41 57 34 / 60 60 20 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...CANNON
LONG TERM....GSF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
345 AM CDT MON APR 2 2012
.SHORT TERM...
ISSUED AT 341 AM CDT MON APR 2 2012
(TODAY)
MAIN QUESTION FOR TODAY WILL BE HOW WARM WILL IT GET. CURRENTLY
HAVE A BACKDOOR COLD FRONT STALLED OUT OVER FORECAST AREA. IT
EXTENDS FROM NORTHWESTERN MO THROUGH MEXICO MO THEN EASTWARD INTO
SOUTHERN IL...JUST NORTH OF ST. LOUIS METRO AREA. BELIEVE IT WILL
SLOWLY WEAKEN AND WASH OUT OVER TIME TODAY...WITH WINDS PICKING UP
FROM THE SOUTH. SO TEMPS TO WARM UP INTO THE MID TO UPPER
80S...SIMILAR TO YESTERDAY WITH RECORD OR NEAR RECORD HIGHS. IF AIR
MASS RECOVERS FASTER THAN CURRENT THINKING...COULD SEE TEMPS WARM
UP INTO THE LOWER 90S. AS FOR ANY CLOUD COVER...SHOULD BE A MOSTLY
SUNNY DAY...WITH PERHAPS A FEW MORE CLOUDS OVER NORTHEASTERN
PORTIONS OF FORECAST AREA...CLOSER TO BACKDOOR COLD FRONT.
BYRD
&&
.LONG TERM...
ISSUED AT 345 AM CDT MON APR 2 2012
(TONIGHT THROUGH SUNDAY)
A LONGWAVE UPPER RIDGE WILL CONTINUE TO PERSIST OUR REGION INTO NEXT
WEEKEND. NORMALLY THIS PATTERN WOULD FORETELL MAINLY DRY WX AND
ABOVE AVERAGE TEMPS...BUT A STRONG STORM SYSTEM OVER THE SWRN CONUS
THAT IS IN THE PROCESS OF GETTING CUTOFF FROM THE MAIN FLOW WILL
FOIL MUCH OF THAT FOR MID AND LATE WEEK WITH WHAT SHOULD BE A WET
PERIOD WITH TEMPS CLOSER TO AVERAGE FOR THIS TIME OF YEAR. WHILE AN
ARGUMENT CAN BE MADE THAT MUCH ABOVE AVERAGE TEMPS HAVE BECOME THE
NEW NORMAL RECENTLY...AVERAGE TEMPS WERE LAST SEEN IN OUR AREA ABOUT
FOUR WEEKS AGO...SO COULD BE A MOMENTUS OCCASION.
IN THE MEANTIME...TONIGHT IS LOOKING INCREASINGLY DRY AND CLEAR AS
FRONT IS FURTHER DELAYED FROM THE NW AND WHAT SHOULD BE A DORMANT
LEAD IMPULSE SHOULD FALL SHORT OF THE SWRN FA BY 12Z/TUES. TUESDAY
TRENDS REMAIN SIMILAR TO BEFORE...AS LEAD IMPULSE TRACKS THRU MAINLY
SERN MO AND SRN IL SHOULD SPAWN NUMEROUS TSRA DURING THE HEATING OF
THE DAY IN A REGIME THAT CONSISTS OF A VERY MOIST AND MODERATELY
UNSTABLE ATMOSPHERE WITH NO CAP. FRONT EDGING INTO NRN MO AND CNTRL
IL SHOULD ALSO BE ABLE TO RESULT IN SCT CONVECTION. VORT MAX DRIVEN
ACTIVITY WILL DIMINISH/EXIT TO THE E-SE TUESDAY EVENING WHILE
ACTIVITY ALONG THE FRONT TO THE N WILL ALSO RECEDE. TUESDAY NIGHT
OTHERWISE DID LOOK LIKE A PERIOD OF DOWNTIME FROM PCPN...BUT LATEST
MODELS INDICATE THE INITIAL BAND OF SHRA/TSRA FROM MAIN CUTOFF LO TO
THE W WILL EDGE THE SWRN FA. TUESDAY TEMPS HAVE BEEN BUMPED UP
SIGNFICANTLY WITH FRONT MUCH DELAYED AND ENOUGH SUN BEFORE BETTER
TSRA CHCS LATER IN THE AFTN...TO RESULT IN WIDESPREAD TEMPS IN THE
80-85 RANGE...REFLECTING THE EARLIER TRENDS OF THE MAV MOS.
WEDNESDAY THRU THURSDAY LOOKS TO BE THE BEST CHC FOR WIDESPREAD
PCPN...WITH TEMPS BACKING OFF TOWARDS AVERAGE BY THURSDAY...AND
PROBABLY AGAIN ON FRIDAY WITH LEFTOVER CLOUDS AND BUILDING CANADIAN
HI PRES FROM THE NE.
ONCE THE CUTOFF SYSTEM EXITS OUR REGION...LONGWAVE RIDGE WILL
RE-ASSUME ITS DOMINANCE AND EVEN DEFLECT A SHORTWAVE TO OUR N FOR
NEXT WEEKEND. HOWEVER...SFC FRONTAL BOUNDARY EXPECTED TO SETTLE IN
DURING NEXT WEEKEND COULD RESULT IN EXTENDED RAIN CHCS AGAIN. 30PCT
IS CLIMO FOR THIS TIME OF YEAR...AND WITH FRONTAL BOUNDARY INVOF OUR
REGION...HAVE 30-40PCT GOING FOR BOTH SATURDAY AND SUNDAY.
TES
&&
.AVIATION...
ISSUED AT 1129 PM CDT SUN APR 1 2012
STILL CONCERNED THAT THERE COULD BE SOME STRATUS DEVELOPMENT AFTER
09Z OVER THE OZARKS AND SPREADING NORTH INTO CENTRAL AND EASTERN
MISSOURI AS WELL AS SOUTHWEST ILLINOIS. BASICALLY NOTHING HAS
CHANGED FROM EARLIER...WITH SOME GUIDANCE HINTING AT STRATUS AND
OTHERS STAYING CLEAR. WILL OPT FOR STATUS QUO AT THIS TIME AND
KEEP SCATTERED 1200FT IN STL METRO TAFS AS WELL AS COLUMBIA.
ADDITIONALLY...A LOW LEVEL JET STREAK IS TRYING TO RAMP UP OVER
CENTRAL MISSOURI ACCORDING TO THE NAM AND RUC MODELS BRINGING WIND
SPEEDS UP TO AROUND 40KTS AT 1000FT SO WILL INCLUDE LLWS IN THE
COU TAF UNTIL THE JET STREAK WEAKENS IN A FEW HOURS.
OTHERWISE...EXPECT LIGHT AND VARIABLE SURFACE WINDS WITH VFR
FLIGHT CONDITIONS FOR THE REST OF THE NIGHT. WIND WILL PICK UP
FROM THE SOUTH-SOUTHWEST AGAIN MONDAY WITH VFR FLIGHT CONDITIONS
CONTINUING.
SPECIFICS FOR KSTL...STILL CONCERNED THAT THERE COULD BE SOME
STRATUS DEVELOPMENT AFTER 09Z OVER THE OZARKS AND SPREADING NORTH
INTO THE VICINITY OF LAMBERT FIELD BEFORE SUNRISE. BASICALLY
NOTHING HAS CHANGED FROM EARLIER...WITH SOME GUIDANCE HINTING AT
STRATUS AND OTHERS STAYING CLEAR. WILL OPT FOR STATUS QUO AT THIS
TIME AND KEEP SCATTERED 1200FT IN AT LAMBERT. OTHERWISE...EXPECT
LIGHT AND VARIABLE SURFACE WINDS WITH VFR FLIGHT CONDITIONS FOR
THE REST OF THE NIGHT. WIND WILL PICK UP FROM THE SOUTH-SOUTHWEST
AGAIN MONDAY WITH VFR FLIGHT CONDITIONS CONTINUING.
CARNEY
&&
.CLIMATE...
ISSUED AT 345 AM CDT MON APR 2 2012
RECORD MAX AND HI MIN TEMPS FOR TODAY
SAINT LOUIS (KSTL) 88/1946 68/1946
COLUMBIA (KCOU) 85/1946 65/1956
QUINCY (KUIN) 85/1940 62/1963
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
341 AM CDT MON APR 2 2012
.SHORT TERM...
ISSUED AT 341 AM CDT MON APR 2 2012 (TODAY)
MAIN QUESTION FOR TODAY WILL BE HOW WARM WILL IT GET. CURRENTLY
HAVE A BACKDOOR COLD FRONT STALLED OUT OVER FORECAST AREA. IT
EXTENDS FROM NORTHWESTERN MO THROUGH MEXICO MO THEN EASTWARD INTO
SOUTHERN IL...JUST NORTH OF ST. LOUIS METRO AREA. BELIEVE IT WILL
SLOWLY WEAKEN AND WASH OUT OVER TIME TODAY...WITH WINDS PICKING UP
FROM THE SOUTH. SO TEMPS TO WARM UP INTO THE MID TO UPPER
80S...SIMILAR TO YESTERDAY WITH RECORD OR NEAR RECORD HIGHS. IF AIR
MASS RECOVERS FASTER THAN CURRENT THINKING...COULD SEE TEMPS WARM
UP INTO THE LOWER 90S. AS FOR ANY CLOUD COVER...SHOULD BE A MOSTLY
SUNNY DAY...WITH PERHAPS A FEW MORE CLOUDS OVER NORTHEASTERN
PORTIONS OF FORECAST AREA...CLOSER TO BACKDOOR COLD FRONT.
BYRD
&&
.LONG TERM...
ISSUED AT 313 PM CDT SUN APR 1 2012
(MONDAY THROUGH NEXT SUNDAY)
TOMORROW STILL LOOKS THAT IT WILL BE AS WARM AS TODAY IF NOT A BIT
WARMER WITH RECORD OR NEAR RECORD HIGHS. CURRENT (3 PM) TEMPS ARE
IN THE MID TO UPPER 80S. LOWS TOMORROW MORNING OVER MUCH OF THE AREA
ARE EXPECTED TO BE ABOUT 3-6 DEGREES WARMER THAN THIS MORNING.
FORECAST SOUNDINGS STILL INDICATE THAT WE SHOULD MIX UP TO AROUND
850MB WHERE TEMPERATURES WILL BE 18-21C RANGE. ANY CLOUDS AROUND IN
THE MORNING SHOULD THIN OUT BY LATE MORNING ALLOWING MAINLY SUNNY
SKIES. THIS SUPPORTS TEMPERATURES IN THE UPPER 80S TO AROUND
90...ESPECIALLY FROM THE ST. METRO AREA WESTWARD WHERE A SOUTH
SOUTHWESTERLY WINDS WILL FAVOR SLIGHTLY WARMER TEMPERATURES IN THE
LEE OF THE OZARKS.
RAIN CHANCES STILL LOOK TO BE SUPPRESSED THROUGH MONDAY NIGHT WITH
AN UPPER RIDGE OVER THE AREA. HAVE LEANED TOWARD THE ECMWF FOR MOST
OF THE FORECAST AS IT HAS BEEN THE MOST CONSISTENT WITH THE
PLACEMENT OF THE UPPER LOW AND THE DEPICTION OF THE SURFACE FRONT
THAT WILL MOVE ACROSS THE AREA ON TUESDAY. THE 500MB TROUGH THAT
THE GFS IS BRINGING INTO EASTERN MO ON TUESDAY LOOKS TO BE OVERLY
INFLUENCED BY CONVECTIVE FEEDBACK. WITH THIS IN MIND...HAVE KEPT
LIKELY POPS OVER THE SOUTHERN CWA ON TUESDAY AFTERNOON WHERE THE
FRONT WILL BE DURING THE MOST UNSTABLE TIME OF THE DAY. I THEN KEEP
CHANCES OF STORMS OVER SOUTHEASTERN MO INTO SOUTHERN IL ON TUESDAY
NIGHT CLOSE TO WHERE THE FRONT WILL STALL OUT. A 500MB LOW WILL
THEN MOVE FROM THE CENTRAL HIGH PLAINS ON TUESDAY EVENING INTO THE
MID SOUTH BY LATE THURSDAY. HAVE KEPT LIKELY POPS GOING WEDNESDAY
AND WEDNESDAY NIGHT WHEN STRONG LARGE SCALE ASCENT FROM THE UPPER
LOW WILL COINCIDE WITH DECENT LOW LEVEL MOISTURE CONVERGENCE ON THE
NORTHERN SIDE OF ITS TRACK. DRY WEATHER STILL LOOKS LIKE IT WILL
SET IN LATE THURSDAY INTO FRIDAY IN THE WAKE OF THE LOW. THE ECMWF
HAS COME INTO AGREEMENT WITH THE GFS ON THE POTENTIAL FOR SCATTERED
SHRA/TSRA ON SATURDAY AS ANOTHER COLD FRONT MOVES ACROSS MO/IL.
WHILE IT WILL BE COOLER ON TUESDAY...TEMPERATURES WILL STILL BE WAY
ABOVE NORMAL WITH THE SLOWER FRONTAL PASSAGE. TEMPERATURES WILL BE
NEAR NORMAL BEHIND THE FRONT ON WEDNESDAY AND THURSDAY WITH THE
CLOUDS AND RAIN CHANCES.
BRITT
&&
.AVIATION...
ISSUED AT 1129 PM CDT SUN APR 1 2012
STILL CONCERNED THAT THERE COULD BE SOME STRATUS DEVELOPMENT AFTER
09Z OVER THE OZARKS AND SPREADING NORTH INTO CENTRAL AND EASTERN
MISSOURI AS WELL AS SOUTHWEST ILLINOIS. BASICALLY NOTHING HAS
CHANGED FROM EARLIER...WITH SOME GUIDANCE HINTING AT STRATUS AND
OTHERS STAYING CLEAR. WILL OPT FOR STATUS QUO AT THIS TIME AND
KEEP SCATTERED 1200FT IN STL METRO TAFS AS WELL AS COLUMBIA.
ADDITIONALLY...A LOW LEVEL JET STREAK IS TRYING TO RAMP UP OVER
CENTRAL MISSOURI ACCORDING TO THE NAM AND RUC MODELS BRINGING WIND
SPEEDS UP TO AROUND 40KTS AT 1000FT SO WILL INCLUDE LLWS IN THE
COU TAF UNTIL THE JET STREAK WEAKENS IN A FEW HOURS.
OTHERWISE...EXPECT LIGHT AND VARIABLE SURFACE WINDS WITH VFR
FLIGHT CONDITIONS FOR THE REST OF THE NIGHT. WIND WILL PICK UP
FROM THE SOUTH-SOUTHWEST AGAIN MONDAY WITH VFR FLIGHT CONDITIONS
CONTINUING.
SPECIFICS FOR KSTL...
STILL CONCERNED THAT THERE COULD BE SOME STRATUS DEVELOPMENT AFTER
09Z OVER THE OZARKS AND SPREADING NORTH INTO THE VICINITY OF
LAMBERT FIELD BEFORE SUNRISE. BASICALLY NOTHING HAS CHANGED FROM
EARLIER...WITH SOME GUIDANCE HINTING AT STRATUS AND OTHERS STAYING
CLEAR. WILL OPT FOR STATUS QUO AT THIS TIME AND KEEP SCATTERED
1200FT IN AT LAMBERT. OTHERWISE...EXPECT LIGHT AND VARIABLE
SURFACE WINDS WITH VFR FLIGHT CONDITIONS FOR THE REST OF THE
NIGHT. WIND WILL PICK UP FROM THE SOUTH-SOUTHWEST AGAIN MONDAY
WITH VFR FLIGHT CONDITIONS CONTINUING.
CARNEY
&&
.CLIMATE...
ISSUED AT 315 AM CDT SUN MAR 31 2012
SAINT LOUIS...COLUMBIA...AND QUINCY HAVE INDEED SET ALL-TIME
MARCH RECORDS FOR HIGHEST AVERAGE TEMPERATURE OVER THE COURSE OF
THE ENTIRE MONTH...AND NOT BARELY EITHER...BUT BY A LARGE MARGIN.
PLEASE SEE THE MONTHLY CLIMATE SUMMARIES (CLMSTL AND CLMCOU) FOR
ADDITIONAL INFORMATION.
RECORD MAX AND HI MIN TEMPS FOR EARLY APRIL
4/1 4/2
SAINT LOUIS (KSTL) 91/1946 70/1946 88/1946 68/1946
COLUMBIA (KCOU) 88/1946 65/1946 85/1946 65/1956
QUINCY (KUIN) 86/2010 62/1963 85/1940 62/1963
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1152 PM CDT SUN APR 1 2012
.SHORT TERM...
ISSUED AT 313 PM CDT SUN APR 1 2012
(TONIGHT)
UNSEASONABLY WARM TEMPERATURES ARE EXPECTED AGAIN TONIGHT WITH
OVERNIGHT LOWS FCST TO BE APPROXIMATELY 20-25 DEG F ABOVE AVERAGE
FOR THIS TIME OF YEAR. MOISTURE ADVECTION AHEAD OF A DEVELOPING LOW
PRESSURE SYSTEM MAY CAUSE SOME STRATUS TO DEVELOP AND ADVECT NWD
OVERNIGHT.
KANOFSKY
&&
.LONG TERM...
ISSUED AT 313 PM CDT SUN APR 1 2012
(MONDAY THROUGH NEXT SUNDAY)
TOMORROW STILL LOOKS THAT IT WILL BE AS WARM AS TODAY IF NOT A BIT
WARMER WITH RECORD OR NEAR RECORD HIGHS. CURRENT (3 PM) TEMPS ARE
IN THE MID TO UPPER 80S. LOWS TOMORROW MORNING OVER MUCH OF THE AREA
ARE EXPECTED TO BE ABOUT 3-6 DEGREES WARMER THAN THIS MORNING.
FORECAST SOUNDINGS STILL INDICATE THAT WE SHOULD MIX UP TO AROUND
850MB WHERE TEMPERATURES WILL BE 18-21C RANGE. ANY CLOUDS AROUND IN
THE MORNING SHOULD THIN OUT BY LATE MORNING ALLOWING MAINLY SUNNY
SKIES. THIS SUPPORTS TEMPERATURES IN THE UPPER 80S TO AROUND
90...ESPECIALLY FROM THE ST. METRO AREA WESTWARD WHERE A SOUTH
SOUTHWESTERLY WINDS WILL FAVOR SLIGHTLY WARMER TEMPERATURES IN THE
LEE OF THE OZARKS.
RAIN CHANCES STILL LOOK TO BE SUPPRESSED THROUGH MONDAY NIGHT WITH
AN UPPER RIDGE OVER THE AREA. HAVE LEANED TOWARD THE ECMWF FOR MOST
OF THE FORECAST AS IT HAS BEEN THE MOST CONSISTENT WITH THE
PLACEMENT OF THE UPPER LOW AND THE DEPICTION OF THE SURFACE FRONT
THAT WILL MOVE ACROSS THE AREA ON TUESDAY. THE 500MB TROUGH THAT
THE GFS IS BRINGING INTO EASTERN MO ON TUESDAY LOOKS TO BE OVERLY
INFLUENCED BY CONVECTIVE FEEDBACK. WITH THIS IN MIND...HAVE KEPT
LIKELY POPS OVER THE SOUTHERN CWA ON TUESDAY AFTERNOON WHERE THE
FRONT WILL BE DURING THE MOST UNSTABLE TIME OF THE DAY. I THEN KEEP
CHANCES OF STORMS OVER SOUTHEASTERN MO INTO SOUTHERN IL ON TUESDAY
NIGHT CLOSE TO WHERE THE FRONT WILL STALL OUT. A 500MB LOW WILL
THEN MOVE FROM THE CENTRAL HIGH PLAINS ON TUESDAY EVENING INTO THE
MID SOUTH BY LATE THURSDAY. HAVE KEPT LIKELY POPS GOING WEDNESDAY
AND WEDNESDAY NIGHT WHEN STRONG LARGE SCALE ASCENT FROM THE UPPER
LOW WILL COINCIDE WITH DECENT LOW LEVEL MOISTURE CONVERGENCE ON THE
NORTHERN SIDE OF ITS TRACK. DRY WEATHER STILL LOOKS LIKE IT WILL
SET IN LATE THURSDAY INTO FRIDAY IN THE WAKE OF THE LOW. THE ECMWF
HAS COME INTO AGREEMENT WITH THE GFS ON THE POTENTIAL FOR SCATTERED
SHRA/TSRA ON SATURDAY AS ANOTHER COLD FRONT MOVES ACROSS MO/IL.
WHILE IT WILL BE COOLER ON TUESDAY...TEMPERATURES WILL STILL BE WAY
ABOVE NORMAL WITH THE SLOWER FRONTAL PASSAGE. TEMPERATURES WILL BE
NEAR NORMAL BEHIND THE FRONT ON WEDNESDAY AND THURSDAY WITH THE
CLOUDS AND RAIN CHANCES.
BRITT
&&
.AVIATION...
ISSUED AT 1129 PM CDT SUN APR 1 2012
STILL CONCERNED THAT THERE COULD BE SOME STRATUS DEVELOPMENT AFTER
09Z OVER THE OZARKS AND SPREADING NORTH INTO CENTRAL AND EASTERN
MISSOURI AS WELL AS SOUTHWEST ILLINOIS. BASICALLY NOTHING HAS
CHANGED FROM EARLIER...WITH SOME GUIDANCE HINTING AT STRATUS AND
OTHERS STAYING CLEAR. WILL OPT FOR STATUS QUO AT THIS TIME AND
KEEP SCATTERED 1200FT IN STL METRO TAFS AS WELL AS COLUMBIA.
ADDITIONALLY...A LOW LEVEL JET STREAK IS TRYING TO RAMP UP OVER
CENTRAL MISSOURI ACCORDING TO THE NAM AND RUC MODELS BRINGING WIND
SPEEDS UP TO AROUND 40KTS AT 1000FT SO WILL INCLUDE LLWS IN THE
COU TAF UNTIL THE JET STREAK WEAKENS IN A FEW HOURS.
OTHERWISE...EXPECT LIGHT AND VARIABLE SURFACE WINDS WITH VFR
FLIGHT CONDITIONS FOR THE REST OF THE NIGHT. WIND WILL PICK UP
FROM THE SOUTH-SOUTHWEST AGAIN MONDAY WITH VFR FLIGHT CONDITIONS
CONTINUING.
SPECIFICS FOR KSTL...
STILL CONCERNED THAT THERE COULD BE SOME STRATUS DEVELOPMENT AFTER
09Z OVER THE OZARKS AND SPREADING NORTH INTO THE VICINITY OF
LAMBERT FIELD BEFORE SUNRISE. BASICALLY NOTHING HAS CHANGED FROM
EARLIER...WITH SOME GUIDANCE HINTING AT STRATUS AND OTHERS STAYING
CLEAR. WILL OPT FOR STATUS QUO AT THIS TIME AND KEEP SCATTERED
1200FT IN AT LAMBERT. OTHERWISE...EXPECT LIGHT AND VARIABLE
SURFACE WINDS WITH VFR FLIGHT CONDITIONS FOR THE REST OF THE
NIGHT. WIND WILL PICK UP FROM THE SOUTH-SOUTHWEST AGAIN MONDAY
WITH VFR FLIGHT CONDITIONS CONTINUING.
CARNEY
&&
.CLIMATE...
ISSUED AT 315 AM CDT SUN MAR 31 2012
SAINT LOUIS...COLUMBIA...AND QUINCY HAVE INDEED SET ALL-TIME
MARCH RECORDS FOR HIGHEST AVERAGE TEMPERATURE OVER THE COURSE OF
THE ENTIRE MONTH...AND NOT BARELY EITHER...BUT BY A LARGE MARGIN.
PLEASE SEE THE MONTHLY CLIMATE SUMMARIES (CLMSTL AND CLMCOU) FOR
ADDITIONAL INFORMATION.
RECORD MAX AND HI MIN TEMPS FOR EARLY APRIL
4/1 4/2
SAINT LOUIS (KSTL) 91/1946 70/1946 88/1946 68/1946
COLUMBIA (KCOU) 88/1946 65/1946 85/1946 65/1956
QUINCY (KUIN) 86/2010 62/1963 85/1940 62/1963
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
419 AM CDT MON APR 2 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT. THE PATTERN ALOFT
REVEALED AN UPPER TROUGH IN THE ROCKIES WITH THE MID/UPPER
CIRCULATION CLOSING OFF NEAR THE FOUR CORNERS REGION. AHEAD OF THIS
SYSTEM...SOUTHWEST FLOW WAS IN PLACE ACROSS THE CENTRAL PLAINS WHILE
UPPER RIDGE HAD SHIFTED EAST OF THE MISSOURI RIVER. AT THE
SURFACE...LOW PRESSURE WAS CENTERED IN FAR NORTHWEST KANSAS...WITH
COOL FRONTAL BOUNDARY EXTENDING FROM VTN TO KSNY...AND DRYLINE
EXTENDED ACROSS EASTERN CO. PRESSURE RISES BEHIND THE FRONT BEHIND
THE FRONT AVERAGED 3-5MB.
THERE HAVE BEEN SOME DISTINCT CHANGES IN FRONTAL TIMING...WINDS AND
POTENTIAL FOR CONVECTION TODAY. SURFACE FRONT STILL ENTERS OUR
WESTERN CWA AROUND 12Z...BUT SLOWS AND STALLS ACROSS OUR SOUTHEAST
CWA AROUND MID AFTERNOON. INSTABILITY PROGS INDICATE MUCAPE AROUND
1500 J/KG IN OUR FAR SOUTHEAST CWA FOR A FEW HOURS WITH HIGHER CAPE
AXIS FARTHER SOUTHEAST AHEAD OF THE BOUNDARY...AND A BRIEF PERIOD OF
EFFECTIVE SHEAR OF 30 TO 40KTS RESIDE ALONG THE BOUNDARY...GENERALLY
BETWEEN 21 AND 00Z. AS THE BOUNDARY STALLS IN OUR SOUTHEAST...CAN
NO LONGER RULE OUT CONVECTIVE POTENTIAL AND A WINDOW OF
OPPORTUNITY FOR SEVERE WEATHER WITH STORMS CAPABLE OF PRODUCING
LARGE HAIL/DAMAGING WINDS. 4KM SPC WRF DEVELOPS CONVECTION ACROSS
OUR SOUTHERN CWA IN VCNTY OF BOUNDARY AND WITH CONTINUING TRENDS
OF FRONT SLOWING DOWN...HAVE RETURNED TSTMS TO FORECAST.
ALSO DUE TO SLOWER FRONTAL PROGRESSION TODAY...THIS ALSO HAS AN
IMPACT ON STRENGTH OF WINDS ACROSS OUR REGION. THE CORRIDOR OF
STRONGEST PRESSURE RISES THIS MORNING SLIDE SOUTH FROM WESTERN
NEBRASKA INTO WESTERN KANSAS AND SFC GRADIENT REMAINS TIGHTEST
ACROSS THE WESTERN HALF OF NEBRASKA INTO NW KANSAS. FRONT DOES NOT
REACH OUR EASTERN AND SOUTHEAST COUNTIES UNTIL THIS AFTERNOON OR
EARLY EVENING AND WINDS WILL INITIALLY BE GUSTY OUT OF THE SOUTH BUT
NOT AT WIND ADVISORY CRITERIA. AS FRONT PUSHES THRU OUR SOUTHEAST
CWA IN THE EVENING...A SECONDARY SURGE OF PRESSURE RISES AND
CORRIDOR OF 40KT MID LEVEL WINDS MOVE THRU BEGINNING GENERALLY
AROUND 00Z AND LINGERING/SPREADING SOUTHWARD UNTIL AROUND
MIDNIGHT. WHAT THIS MEANS IS THAT REACHING WIND ADVISORY CRITERIA
ESPECIALLY IN OUR EAST/SOUTHEAST IS LOOKING LESS LIKELY UNTIL
POTENTIALLY CLOSER TO 00Z WITH SECONDARY SURGE OF FRONT/PRESSURE RISES.
OUR WESTERN COUNTIES WILL STILL STAND A BETTER CHC FOR WIND
ADVISORY CRITERIA BUT IN ESSENCE MAY BE MORE OF A BUFFER TO THE
EVEN HIGHER WINDS ACROSS WESTERN NEBRASKA AND KANSAS. FOR
HEADLINE...OPTIONS ARE TO EITHER CANCEL EASTERN/SOUTHEAST PORTION
OR HOLD OFF ON TIMING UNTIL THE EVENING HOURS. HAVE OPTED TO
REMOVE WIND ADVISORY IN THE EAST AND MAINTAIN A BUFFER IN THE
WEST. LATEST HRRR SUGGESTS STRONGER WINDS COULD HOLD OFF EVEN IN
OUR WEST UNTIL AFTN WHILE THE INITIALLY STRONGER WINDS WILL BE FM
THE SOUTH IN OUR EASTERN COUNTIES.
OTHER CHANGE IN MODELS...WHICH HAS BEEN A GENERAL TREND AS WELL...IS
THE FARTHER NORTH TRACK OF THE UPPER LOW AS IT LIFTS FM THE TX/OK
PANHANDLES TUESDAY. GENERAL CONSENSUS IS THAT LOW WILL LIFT AND
TRACK ACROSS KANSAS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AND THE
ECMWF REMAINS SLOWER WITH PROGRESSION WHICH COULD POTENTIALLY LINGER
PCPN CHCS BEYOND WEDNESDAY NIGHT. LATEST TRACK PROMISES TO PROVIDE
A DECENT RAIN EVENT ACROSS THE CENTRAL PLAINS MAINLY FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. POPS HAVE BEEN TRENDED UPWARD INTO
LIKELY CATEGORY...AND SOME DECENT SPRING RAINFALL TOTALS ARE
POSSIBLE WITH PRECIPITABLE WATER VALUES AVERAGING 0.75 TO JUST OVER
AN INCH. HAVE KEPT THUNDER WORDING OUT AS INSTABILITY PARAMETERS
ARE RATHER MEAGER BUT WOULD NOT BE SURPRISED TO SEE AN OUTSIDE
LIGHTNING STRIKE HERE OR THERE...ESPECIALLY IN OUR SOUTHEAST WHERE
MUCAPES ARE NOT ZERO...JUST RATHER LOW.
.LONG TERM...THURSDAY THROUGH SUNDAY. PRIMARY FOCUS THROUGH THIS
4-DAY PERIOD IS THE RISK FOR THUNDERSTORMS IN THE FRI-SAT TIME
FRAME...BUT MAINLY CENTERED FRIDAY NIGHT AND NOT EVEN IN LIKELY
POP TERRITORY YET. ALTHOUGH NOT NEARLY AS WARM AS LATELY...HIGH
TEMPS THROUGH THIS PERIOD SHOULD NONETHELESS AVERAGE SOLIDLY IN THE
60S MOST AREAS...OR STILL SLIGHTLY ABOVE NORMAL FOR EARLY APRIL. AS
FOR OVERNIGHT LOWS...WILL HAVE TO KEEP AN EYE OUT AS EARLY AS SAT
NIGHT FOR POSSIBLE FROST POTENTIAL.
STARTING OFF THURSDAY...00Z ECMWF/GFS RUNS ARE IN DECENT AGREEMENT
DEPICTING A DEPARTING MID LEVEL CLOSED LOW GENERALLY WANDERING
SOMEWHERE OVER MO. AT THE SAME TIME...A FAIRLY EXPANSIVE UPSTREAM
TROUGH WILL BE CENTERED OVER THE WESTERN 1/3 OF THE CONUS. AT
LEAST FOR NOW...LEFT THURSDAY DAYTIME DRY...ALTHOUGH THERE ARE
SOME HINTS THAT AT LEAST SOME EASTERN AREAS COULD STILL BE PRONE
TO SOME LINGERING LIGHT RAIN SHOWERS. FOR NOW THOUGH WILL STAY THE
COURSE AND REMAIN TRUE TO THE DRY FCST INITIALIZED BY THE ALLBLEND
MODEL PROCEDURE. FOR HIGH TEMPS...NUDGED DOWN A FEW DEGREES MOST
AREAS GIVEN PREDOMINANT EASTERLY LOW LEVEL FLOW...WITH THE
MAJORITY OF THE CWA IN THE 62-65 RANGE. KEPT THURS NIGHT DRY AS
PRIMARY LOW LEVEL JET AXIS AND RESULTANT FOCUS FOR POSSIBLE
CONVECTION APPEARS TO REMAIN AT LEAST SLIGHTLY WEST OF THE CWA.
FRIDAY/FRIDAY NIGHT...THIS 24 HOUR PERIOD APPEARS TO FEATURE THE
PRIMARY RISK FOR THUNDERSTORMS IN THE LONG TERM...ESPECIALLY ON
FRIDAY NIGHT. DURING THE DAY...SOUTHEAST WINDS WILL PICK UP INTO
BREEZY TERRITORY AS PRESSURES FALL OVER THE HIGH PLAINS...BUT AT
THIS TIME SPEEDS LOOK TO REMAIN BELOW ADVISORY CRITERIA. ALLBLEND
PROCEDURE INTRODUCED A SLIGHT CHANCE OF STORMS DURING THE DAY
ACROSS WESTERN COUNTIES...AND OPTED TO RUN WITH IT...ALTHOUGH
CONFIDENCE IS RATHER LOW GIVEN EXPECTATION OF WEAK FORCING AND
SOME CAPPING...DESPITE THE ECMWF AND GFS BOTH ADVERTISING A
NARROW...FAIRLY WEAK INSTABILITY AXIS SETTING UP NEAR THE
SOUTHERN/WESTERN EDGES OF THE CWA THROUGH THE DAY. IN ALL HONESTY
THOUGH...THESE SLIGHT CHANCES DURING THE DAY ARE ALREADY ON
SOMEWHAT SHAKY GROUND RIGHT OUT OF THE GATE. BETTER
CHANCES...ALTHOUGH STILL ONLY IN THE 30-40 PERCENT RANGE AT THIS
TIME...ARRIVE FRIDAY NIGHT AS FORCING FROM THE LEADING SHORTWAVE
EMANATING FROM THE WESTERN CONUS TROUGH SWINGS ALONG A TRACK FROM
WY/NORTHERN CO ACROSS WESTERN NE INTO SD. ALTHOUGH THIS TAKES THE
BULK OF THE LARGE SCALE FORCING NORTH OF THE CWA...BOTH MODELS
GENERATE QPF...WITH THE GFS ADVERTISING A SURGE OF INSTABILITY
DURING THE NIGHT...WITH MUCAPE VALUES CLIMBING TO AROUND 1500 J/KG
IN THE PRESENCE OF AT LEAST 40KT OF DEEP LAYER SHEAR. FOR NOW WILL
INTRODUCE A STRONG STORM MENTION IN THE HWO...BUT WILL NEED TO
KEEP A CLOSE EYE ON SEVERE POTENTIAL OVER NEXT FEW DAYS.
SATURDAY...MID RANGE MODELS CONTINUE TO AGREE ON THE LARGER SCALE
PATTERN...WITH THE MAIN MID LEVEL WAVE CROSSING THE DAKOTAS TOWARD
MN...WHILE A SURFACE COLD FRONT TRACKS ACROSS THE CWA AND USHERS
IN DRIER/MORE STABLE AIR. ALLBLEND MODEL KEPT SOME TOKEN SLIGHT
POPS ACROSS FAR NORTHEAST AND SOUTHEAST PORTIONS OF THE CWA DURING
THE DAY...AND WILL LET IT RIDE FOR NOW.
SAT NIGHT/SUNDAY...CONFIDENCE IS RATHER HIGH AT THIS TIME RANGE
THAT DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE DEPARTING
WAVE...ALTHOUGH MODELS START TO DIVERGE ALOFT WITH THE ECMWF
ADVERTISING BROAD WEST-NORTHWEST FLOW WHILE THE GFS IS MORE WEST-
SOUTHWEST. DOWN LOW HOWEVER...THERE IS A DECENT SIGNAL FOR HIGH
PRESSURE TO RULE THE SCENE ON SATURDAY NIGHT WITH FAIRLY LIGHT
WINDS. ALTHOUGH CURRENT FORECAST KEEPS LOWS UP IN THE UPPER 30S-
LOW 40S FOR MOST OF THE CWA...WILL HAVE TO MONITOR FOR THE
POTENTIAL FOR A MORE WIDESPREAD LOW-MID 30S...WHICH COULD AT LEAST
BRING SOME FROST POTENTIAL INTO PLAY. CERTAINLY TOO EARLY AT THIS
TIME TO FORMALLY PUT IT IN THE FORECAST. PEEKING AHEAD A BIT INTO
THE WEEK OF APRIL 9TH...COULD BE A FEW MORE RISKS FOR OVERNIGHT
TEMPS DROPPING DOWN INTO AT LEAST THE FROST POSSIBILITY
RANGE...WHICH IS RIGHT IN LINE WITH CLIMATOLOGY FOR MID APRIL.
&&
.AVIATION...06Z KGRI TAF. WIND WILL BE THE BIGGEST FACTOR FOR THIS
FORECAST. EAST TO SOUTHEAST WIND WILL PREVAIL OVERNIGHT AND WILL
CONTINUE TO BE A BIT ON THE BREEZY SIDE. A COLD FRONT WILL MOVE IN
TOWARD MID-MORNING AND WILL SWITCH WIND DIRECTION TO THE NORTH
NORTHWEST AND WILL BECOME VERY GUSTY FROM STRONG HEIGHT
RISES...ESPECIALLY TOWARD EVENING. ANY PRECIPITATION SHOULD HOLD
OFF TO THE SOUTH AND WELL AFTER THE FRONT PASSES THROUGH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 11 PM CDT THIS EVENING
FOR NEZ061-073-083.
WIND ADVISORY FROM 11 AM THIS MORNING TO 11 PM CDT THIS EVENING
FOR NEZ039-046-060-072-082.
KS...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 11 PM CDT THIS EVENING
FOR KSZ005-017.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
335 AM EDT MON APR 2 2012
.SYNOPSIS...
SKIES WILL GRADUALLY CLEAR TODAY AS HIGH PRESSURE BUILDS ACROSS THE
REGION FROM CANADA. TEMPERATURES WILL DROP BELOW FREEZING ACROSS THE
REGION UNDERNEATH THE HIGH PRESSURE RIDGE. THEN A WEAK SYSTEM WILL
BRING A SMALL CHANCE OF SHOWERS TUESDAY BEFORE DRY WEATHER RETURNS
FOR THE REST OF THE WEEK ALONG WITH SEASONABLE TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...THE MAIN FORECAST CHALLENGE WILL BE DETERMINING EXACTLY
WHEN SKIES WILL CLEAR OUT. WITH HIGH PRESSURE SLOWLY BUILDING FROM
THE WEST...SKIES HAVE QUICKLY CLEARED TO THE NORTH...WITH IR
SATELLITE SHOWING A NORTH TO SOUTH CLEARING. HOWEVER...THE 11U-3.9U
SATELLITE PRODUCT SHOWS LOW CLOUDS BUILDING BACK BEHIND THIS
APPARENT CLEARING LINE...WHICH WILL SLOW THE CLEARING PROGRESSION.
WHILE NAM/GFS MODEL GUIDANCE WANTS US TO CLEAR OUT BY 09Z OR
SO...GIVEN THE UPSLOPING NORTHERLY FLOW AND -5C 850 MB TEMPS EXPECT
LOW CLOUDS TO LINGER INTO THE MORNING HOURS IN MOST LOCATIONS SOUTH
OF LAKE ONTARIO...AND PERHAPS INTO THE AFTERNOON ACROSS HIGHER
TERRAIN IN THE SOUTHERN TIER. THIS IS ALSO CONSISTENT WITH SEVERAL
RECENT NORTHERLY FLOW EVENTS...WHERE MODEL GUIDANCE WAS SIMPLY TOO
QUICK TO CLEAR OUT CLOUDS. NOTE RECENT RUNS OF THE RUC SEEM TO
CAPTURE THIS LOW MOISTURE NICELY...SO IN TERMS OF SKY COVER...USED A
RUC WEIGHTED BEND FOR TIMING THE CLEARING. THIS SAID...DRIER AIR
SHOULD EVENTUALLY WIN OUT...WITH ABUNDANT SUNSHINE LIKELY BY THIS
AFTERNOON. TEMPERATURES SHOULD RISE INTO THE UPPER 40S TO AROUND 50
TODAY...ASSUMING THAT CLOUDS CLEAR OUT EARLY ENOUGH FOR SOME
SIGNIFICANT SUNSHINE DURING THE AFTERNOON HOURS.
ALSO...PATCHY FOG WILL LIKELY DEVELOP IN AREAS WHICH DO CLEAR
THROUGH EARLY THIS MORNING...WITH THE BEST CHANCE FOR MORNING FOG
NEAR THE LAKE ONTARIO SHORELINE.
FOR TONIGHT...HIGH PRESSURE WILL BUILD ACROSS THE REGION...AND WITH
DRIER AIR IN PLACE...SEE NO REASON WHY WE WILL NOT EXPERIENCE GOOD
RADIATIONAL COOLING CONDITIONS. WITH CONFIDENCE IN RADIATIONAL
COOLING...WILL FAVOR THE COLDER MOS NUMBERS OVER BIAS CORRECTED
GRIDS FOR LOWS TONIGHT. THIS SHOULD RESULT IN FREEZING TEMPERATURES
ACROSS THE REGION...WITH MANY SPOTS FURTHER FROM THE LAKE SHORE
LIKELY TO DROP INTO THE 20S. BECAUSE OF THIS...WILL TRANSITION THE
FREEZE WATCH INTO A FREEZE WARNING.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AFTER A COLD AND FROSTY START TO THE DAY...TUESDAY WILL FEATURE A
GRADUAL INCREASE IN MID AND HIGH LEVEL CLOUDS AS A WEAK SURFACE
TROUGH MOVES EAST TOWARD THE LOWER GREAT LAKES. THE MODELS CONTINUE
TO SUGGEST THAT THE DEEPEST LOW LEVEL MOISTURE WILL REMAIN WELL
SOUTH OF NEW YORK STATE...WHILE THE BEST UPPER LEVEL SUPPORT STAYS
TO OUR NORTH IN THE VICINITY OF THE DIGGING UPPER LEVEL TROUGH
OVER ONTARIO PROVINCE. THIS CONFIRMS THE TREND OF PREVIOUS MODEL
RUNS OF A DRY FORECAST.
WARM ADVECTION IN ADVANCE OF THE TROUGH WILL BRING SOME MODERATION
IN TEMPERATURES ON TUESDAY...WITH HIGH TEMPERATURES LIKELY RANGING
FROM THE LOWER TO MID 50S ACROSS THE NORTH COUNTRY TO THE LOWER 60S
ACROSS THE SOUTHERN TIER AND UPPER GENESEE VALLEY.
AS THE TROUGH CROSSES THE AREA TUESDAY NIGHT...IT LOOKS LIKE IT WILL
TAP SOME OF THE DEEPER MOISTURE TO OUR SOUTH AND PRODUCE A FEW
SHOWERS. MODEST COOL AIR ADVECTION WILL TAKE PLACE BEHIND THE TROUGH
AND ALLOW TEMPERATURES TO INTO THE 30S. THIS COULD RESULT IN A MIX
OF RAIN AND SNOW SHOWERS FOR A BRIEF TIME ACROSS THE NORTH COUNTRY
WHERE TEMPERATURES ALOFT WILL BE COOLING FASTER.
ON WEDNESDAY...THE UPPER LEVEL TROUGH IS FORECAST DEEPEN OVER
SOUTHERN QUEBEC AND NORTHERN NEW ENGLAND...WITH A FAIRLY SIGNIFICANT
VORT LOBE DROPPING SOUTHEAST ACROSS CENTRAL AND EASTERN NEW YORK.
WITH JUST ENOUGH MOISTURE IN PLACE...THE LIFT ASSOCIATED WITH THIS
FEATURE MAY BE JUST ENOUGH TO SQUEEZE OUT A FEW SHOWERS ACROSS THE
NORTH COUNTRY AND PERHAPS THE EASTERN FINGER LAKES. FARTHER TO THE
WEST...A DRIER AIRMASS WILL BE IN PLACE. THIS SHOULD RESULT IN
MAINLY DRY CONDITIONS. ONGOING COLD AIR ADVECTION ASSOCIATED WITH
THE DEEPENING UPPER LEVEL TROUGH WILL RESULT IN A NOTICEABLY COOLER
AND MORE SEASONABLE DAY THAN TUESDAY...WITH DAYTIME HIGH
TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
ANY SHOWERS SHOULD THEN DIE OUT FAIRLY QUICKLY WITH THE DEPARTURE OF
THE VORT LOBE AND LOSS OF HEATING WEDNESDAY EVENING...LEAVING BEHIND
A DRY BUT ALSO CHILLY NIGHT...WITH WIDESPREAD LOWS IN THE UPPER 20S
TO LOWER 30S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
IN THE EXTENDED PERIOD...THE GUIDANCE REMAINS IN GOOD AGREEMENT THAT
THE MAIN UPPER LEVEL TROUGH WILL LINGER ACROSS THE REGION INTO
FRIDAY...BEFORE FINALLY SLIDING OFF TO THE EAST NEXT WEEKEND AND
ALLOWING UPPER-LEVEL RIDGING TO GRADUALLY BUILD EAST FROM THE UPPER
MIDWEST/ WESTERN GREAT LAKES. MEANWHILE AT THE SURFACE...HIGH
PRESSURE AND DRIER AIR WILL CONTINUE TO BUILD SOUTHEAST FROM CENTRAL
CANADA... EVENTUALLY CRESTING ACROSS THE AREA ON SUNDAY.
UNDER THIS PATTERN...DRY AND SEASONABLY COOL WEATHER SHOULD REMAIN
THE GENERAL RULE FOR BOTH THURSDAY AND FRIDAY. TEMPERATURES SHOULD
AVERAGE OUT CLOSE TO OR A LITTLE BELOW SEASONAL NORMALS BOTH
DAYS...WITH A WIDESPREAD FROST OR FREEZE POSSIBLE BOTH THURSDAY AND
FRIDAY NIGHTS.
THEREAFTER...DRY WEATHER SHOULD CONTINUE THROUGH NEXT WEEKEND...
ALONG WITH A WARMING TREND AS RIDGING BUILDS ACROSS THE AREA AT ALL
LEVELS. WITH THE MEDIUM RANGE GUIDANCE CONTINUING TO SHOW BOTH
RUN-TO-RUN AND MODEL-TO-MODEL INCONSISTENCIES WITH THE EXTENT OF
THIS WARMING TREND...FOR NOW WILL CONTINUE TO AIM A BIT ON THE
CONSERVATIVE SIDE FOR TEMPS...INDICATING HIGHS REACHING INTO THE MID
AND UPPER 50S BY SATURDAY...AND THE UPPER 50S TO LOWER 60S BY SUNDAY.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
THE MAIN CONCERN WILL BE LINGERING MVFR TO IFR CIGS. WITH HIGH
PRESSURE BUILDING FROM THE WEST...SATELLITE SHOWS A GENERAL NORTH
TO SOUTH CLEARING TREND. HOWEVER...THIS CLEARING LINE IS STALLING
SOUTH OF LAKE ONTARIO...WHERE COLD TEMPS ALOFT AND UPSLOPING ARE
THE LIKELY CULPRIT. NOTED NAM/GFS GUIDANCE IS TOO OPTIMISTIC WITH
THIS...WITH THE RUC BUFKIT SOUNDING SUGGESTING THAT LOW CLOUDS
WILL LINGER INTO THIS MORNING. OUTSIDE OF ART...WILL HEDGE MORE
PESSIMISTIC WITH ALL TAFS WITH RESPECT TO THE CLEARING. ONE OTHER
THING TO WATCH FOR...IS IF CLOUDS DO CLEAR...IT MAY QUICKLY BE
REPLACED WITH FOG...OR A LOWER CLOUD DECK AS BOUNDARY LAYER TEMPS
QUICKLY COOL TO THE DEW POINT.
OTHERWISE...EXPECT CLOUDS TO SCATTER OUT IN THE LATE MORNING TO
EARLY AFTERNOON TIMEFRAME AS DRIER AIR WORKS IN AND FINALLY WINS
OUT. INCREASING CONFIDENCE IN VFR CONDITIONS MONDAY AFTERNOON AND
MONDAY NIGHT.
OUTLOOK...
TUESDAY...VFR.
TUESDAY NIGHT...VFR/MVFR WITH CHANCE SHOWERS.
WEDNESDAY...MAINLY VFR WITH CHANCE SHOWERS ACROSS THE NORTH COUNTRY.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
NW WINDS AROUND 15 KTS ON THE EASTERN HALF OF LAKE ONTARIO WILL
RESULT IN MARGINAL SMALL CRAFT CONDITIONS. STRONGEST FLOW WILL BE
THROUGH 12Z...SO WILL HANG ONTO THE SCA HEADLINE ON THE EASTERN HALF
OF THE LAKE FOR NOW...BUT MAY BE ABLE TO DROP EARLY IF WINDS DO NOT
INCREASE A BIT.
AFTER THIS...HIGH PRESSURE BUILDS IN...WITH A FAIRLY EXTENDED PERIOD
OF GENERALLY LIGHT WINDS ON THE LAKES EXPECTED. PERSISTENT RIDGING
MAY KEEP THE WATERS FREE OF HEADLINES THROUGH THE END OF THE WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT TUESDAY FOR
NYZ001>006-010-011-013-014-019-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LOZ043-
044.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/TJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
139 AM EDT MON APR 2 2012
.SYNOPSIS...
WHILE STUBBORN LOW CLOUDINESS WILL BE FOUND ACROSS THE REGION EARLY
TONIGHT...HIGH PRESSURE CENTERED OVER JAMES BAY WILL NOSE SOUTH AND
THIS WILL EVENTUALLY CLEAR OUR SKIES LATE TONIGHT AND MONDAY. THE
HIGH PRESSURE WILL BUILD ACROSS OUR REGION LATE MONDAY...AND THIS
WILL SET THE STAGE FOR SEASONABLY COLD CONDITIONS MONDAY NIGHT WITH
A HARD FREEZE LIKELY AWAY FROM THE LAKES. A WEAK SYSTEM WILL BRING A
SMALL CHANCE OF SHOWERS TUESDAY BEFORE DRY WEATHER RETURNS FOR THE
REST OF THE WEEK ALONG WITH SEASONABLE TEMPERATURES.
&&
.NEAR TERM /THROUGH TODAY/...
THROUGH 100 AM...11U-3.9U SATELLITE SHOWS LOW CLOUDS LINGERING
BUILDING SOUTH OF LAKE ONTARIO...DESPITE THE BROAD CLEARING TREND
TO THE NORTH. BASED ON THIS...EXPECT MOST LOCATIONS WHICH ARE
CLOUDY TO REMAIN SO FOR MOST OF TONIGHT...WHICH WILL LIMIT
RADIATIONAL COOLING. NUDGED UP TEMPS WHERE ITS CLOUDY...AND
CONTINUE WITH A MENTION OF FOG...ESPECIALLY IN AREAS WHICH DO
CLEAR WHERE FOG MAY FORM.
WEAK LOW PRESSURE IN THE VCNTY OF CENTRAL PENNSYLVANIA WILL KEEP A
WAVY FRONTAL BOUNDARY CLOSE ENOUGH TO OUR FORECAST AREA TO HOLD A
WEALTH OF LOW LEVEL MOISTURE IN PLACE FOR THE BULK OF THE UPCOMING
NIGHT. ONCE THE WAVE MOVES EAST...HIGH PRESSURE CENTERED OVER JAMES
BAY WILL BUILD SOUTH OVER THE LOWER GREAT LAKES. WHILE THIS PROCESS
WILL EVENTUALLY PROMOTE CLEARING...IT WILL TAKE SOME TIME.
HAVE ALREADY SLOWED THE CLEARING TREND FOR THE OVERNIGHT...AND MAY
HAVE TO DO THE SAME FOR MONDAY AS A NORTHERLY UPSLOPE FLOW WILL BE
FOUND OVER THE REGION. AS WAS MENTIONED IN PREVIOUS DISCUSSIONS...
THE PAST FEW SCENARIOS SIMILAR TO THIS HAVE SEEN CLOUDS HANG IN MUCH
LONGER...AS MUCH AS 12-18 HOURS LONGER THAN MODEL FORECASTS.
WITH CLOUD COVER MOST OF THE NIGHT...AND A LIGHT 5-8 MPH
BREEZE...HAVE GONE TOWARD THE HIGH END OF MODEL GUIDANCE FOR
OVERNIGHT LOWS. THE BREEZE AND CLOUD COVER WILL LIKELY PREVENT THE
SURFACE FROM SATURATING...AND THUS PREVENT MUCH FROST FORMATION EVEN
IF TEMPERATURES APPROACH FREEZING. WITH THIS IN MIND WILL NOT GO
WITH ANY FROST HEADLINES FOR TONIGHT AND JUST MENTION SOME PATCHY
LIGHT FROST IN THE FORECAST.
IN TERMS OF TEMPERATURES ON MONDAY...850MB TEMPS AROUND -4C WILL
KEEP TEMPS ON THE COOL SIDE WITH UPPER 40S TO AROUND 50 ACROSS LOWER
ELEVATIONS (ASSUMING AN INCREASING AMOUNT SUNSHINE)...AND MID 40S
HIGHER TERRAIN.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
MONDAY NIGHT...STRONG CANADIAN HIGH PRESSURE WILL RIDGE DIRECTLY
OVER THE FORECAST AREA. PLENTIFUL DRY AIR AND LIGHT WINDS ASSOCIATED
WITH THE SURFACE HIGH WILL PROVIDE IDEAL CONDITIONS FOR RADIATIONAL
COOLING...ALLOWING TEMPERATURES TO FALL INTO THE MID 20S TO LOW 30S
AREAWIDE...WITH SOME LOWER 20S EVEN POSSIBLE IN THE INTERIOR OF THE
SOUTHERN TIER AND NORTH COUNTRY. AS OUR FROST/FREEZE PROGRAM IS NOW
ACTIVE FOR ALL BUT CATTARAUGUS/ALLEGANY/WYOMING/JEFFERSON/LEWIS
COUNTIES...WE WILL BE ISSUING A FREEZE WATCH FOR MONDAY NIGHT FOR
MUCH OF OUR AREA IN COORDINATION WITH WFO BGM.
TUESDAY AND TUESDAY NIGHT...A WEAK TROUGH OF LOW PRESSURE WILL
SLOWLY DRIFT EAST FROM THE WESTERN GREAT LAKES...IN ASSOCIATION WITH
A MODEST SHORTWAVE TROUGH SLIDING THROUGH THE PREVAILING
NORTHWESTERLY FLOW ALOFT. MODEL GUIDANCE HAS CONTINUED TO TREND
MARKEDLY SLOWER AND WEAKER WITH THIS FEATURE OVER THE PAST TWO
DAYS...AND NOW SUGGESTS THAT THIS FEATURE WILL REMAIN FAR ENOUGH TO
OUR WEST TO RESULT IN A LARGELY DRY DAY TUESDAY...FOLLOWED BY ONLY A
BRIEF CHANCE OF SHOWERS TUESDAY EVENING AS THE MAIN TROUGH AXIS
WORKS ACROSS THE AREA ALONG WITH ONLY LIMITED LIFT/MOISTURE. WITH
THE ABOVE IN MIND...HAVE DROPPED POPS FOR TUESDAY TO SLIGHT CHANCE OR
LESS...WITH ANY LOW-END CHANCE OF SHOWERS NOW CONFINED TO JUST
TUESDAY EVENING. HAVE ALSO REMOVED ANY MENTION OF THUNDER GIVEN THE
MORE UNFAVORABLE TIMING OF THIS SYSTEM AND THE UNIMPRESSIVE NATURE
OF ITS ASSOCIATED LIFT/MOISTURE.
WARM ADVECTION IN ADVANCE OF THE TROUGH WILL BRING SOME MODERATION
IN TEMPS ON TUESDAY...WITH HIGH TEMPERATURES LIKELY RANGING FROM THE
LOWER TO MID 50S ACROSS THE NORTH COUNTRY TO THE LOWER 60S ACROSS
THE SOUTHERN TIER. MODEST COOL AIR ADVECTION BEHIND THE LOW WILL
THEN HELP TO SEND TEMPERATURES BACK DOWN INTO THE MID AND UPPER 30S
IN MOST PLACES TUESDAY NIGHT...WITH SOME LOWER 30S POSSIBLE EAST OF
LAKE ONTARIO.
ON WEDNESDAY...UPPER LEVEL TROUGHING WILL CONTINUE TO DIG ACROSS THE
THE EASTERN GREAT LAKES AND NORTHEASTERN STATES...WITH A FAIRLY
SIGNIFICANT VORT LOBE DROPPING SOUTHEAST ACROSS CENTRAL AND EASTERN
NEW YORK. WITH JUST ENOUGH MOISTURE IN PLACE...THE LIFT ASSOCIATED
WITH THIS FEATURE MAY BE JUST ENOUGH TO SQUEEZE OUT A FEW SHOWERS
ACROSS THE NORTH COUNTRY AND PERHAPS THE EASTERN FINGER LAKES...WITH
A DRIER AIRMASS OTHERWISE SUPPORTING MAINLY DRY CONDITIONS ACROSS
THE REMAINDER OF THE FORECAST AREA. ONGOING COLD AIR ADVECTION
ASSOCIATED WITH THE DEEPENING TROUGH WILL RESULT IN A NOTICEABLY
COOLER AND MORE SEASONABLE DAY THAN TUESDAY...WITH DAYTIME HIGH
TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
ANY SHOWERS SHOULD THEN DIE OUT FAIRLY QUICKLY WITH THE DEPARTURE OF
THE VORT LOBE AND LOSS OF HEATING WEDNESDAY EVENING...LEAVING BEHIND
A QUIET/DRY BUT ALSO CHILLY NIGHT...WITH WIDESPREAD LOWS IN THE
UPPER 20S TO LOWER 30S ANTICIPATED.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
IN THE EXTENDED PERIOD...THE GUIDANCE REMAINS IN GOOD AGREEMENT THAT
THE MAIN UPPER LEVEL TROUGH WILL LINGER ACROSS THE REGION INTO
FRIDAY...BEFORE FINALLY SLIDING OFF TO THE EAST NEXT WEEKEND AND
ALLOWING UPPER-LEVEL RIDGING TO GRADUALLY BUILD EAST FROM THE UPPER
MIDWEST/ WESTERN GREAT LAKES. MEANWHILE AT THE SURFACE...HIGH
PRESSURE AND DRIER AIR WILL CONTINUE TO BUILD SOUTHEAST FROM CENTRAL
CANADA... EVENTUALLY CRESTING ACROSS THE AREA ON SUNDAY.
UNDER THIS PATTERN...DRY AND SEASONABLY COOL WEATHER SHOULD REMAIN
THE GENERAL RULE FOR BOTH THURSDAY AND FRIDAY. TEMPERATURES SHOULD
AVERAGE OUT CLOSE TO OR A LITTLE BELOW SEASONAL NORMALS BOTH
DAYS...WITH A WIDESPREAD FROST OR FREEZE POSSIBLE BOTH THURSDAY AND
FRIDAY NIGHTS.
THEREAFTER...DRY WEATHER SHOULD CONTINUE THROUGH NEXT WEEKEND...
ALONG WITH A WARMING TREND AS RIDGING BUILDS ACROSS THE AREA AT ALL
LEVELS. WITH THE MEDIUM RANGE GUIDANCE CONTINUING TO SHOW BOTH
RUN-TO-RUN AND MODEL-TO-MODEL INCONSISTENCIES WITH THE EXTENT OF
THIS WARMING TREND...FOR NOW WILL CONTINUE TO AIM A BIT ON THE
CONSERVATIVE SIDE FOR TEMPS...INDICATING HIGHS REACHING INTO THE MID
AND UPPER 50S BY SATURDAY...AND THE UPPER 50S TO LOWER 60S BY SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THE MAIN CONCERN WILL BE LINGERING MVFR TO IFR CIGS. WITH HIGH
PRESSURE BUILDING FROM THE WEST...SATELLITE SHOWS A GENERAL NORTH
TO SOUTH CLEARING TREND. HOWEVER...THIS CLEARING LINE IS STALLING
SOUTH OF LAKE ONTARIO...WHERE COLD TEMPS ALOFT AND UPSLOPING ARE
THE LIKELY CULPRIT. NOTED NAM/GFS GUIDANCE IS TOO OPTIMISTIC WITH
THIS...WITH THE RUC BUFKIT SOUNDING SUGGESTING THAT LOW CLOUDS
WILL LINGER INTO THIS MORNING. OUTSIDE OF ART...WILL HEDGE MORE
PESSIMISTIC WITH ALL TAFS WITH RESPECT TO THE CLEARING. ONE OTHER
THING TO WATCH FOR...IS IF CLOUDS DO CLEAR...IT MAY QUICKLY BE
REPLACED WITH FOG...OR A LOWER CLOUD DECK AS BOUNDARY LAYER TEMPS
QUICKLY COOL TO THE DEW POINT.
OTHERWISE...EXPECT CLOUDS TO SCATTER OUT IN THE LATE MORNING TO
EARLY AFTERNOON TIMEFRAME AS DRIER AIR WORKS IN AND FINALLY WINS
OUT. INCREASING CONFIDENCE IN VFR CONDITIONS MONDAY AFTERNOON AND
MONDAY NIGHT.
OUTLOOK...
TUESDAY...VFR.
TUESDAY NIGHT...VFR/MVFR WITH CHANCE SHOWERS.
WEDNESDAY...MAINLY VFR WITH CHANCE SHOWERS ACROSS THE NORTH COUNTRY.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
LIGHT WINDS THIS EVENING WILL SHIFT TO THE NORTH AND NORTHEAST
OVERNIGHT AS HIGH PRESSURE WILL PRESS SOUTH FROM JAMES BAY. THESE
WINDS WILL FRESHEN OVERNIGHT THOUGH AS THE PRESSURE GRADIENT WILL
TIGHTEN UP IN ADVANCE OF THE AFOREMENTIONED CANADIAN HIGH PRESSURE
SYSTEM.
THIS WILL RESULT IN MARGINAL SMALL CRAFT ADVISORY CONDITIONS FOR A
FEW HOURS LATE TONIGHT THROUGH MONDAY MORNING ALONG THE SOUTH SHORE
OF LAKE ONTARIO. LAKE ERIE WILL ALSO BECOME CHOPPY LATER TONIGHT
THROUGH MONDAY MORNING SOUTHWEST OF DUNKIRK IN NORTHEAST WINDS...BUT
FOR NOW WILL HOLD THIS AREA AT 2-4 FEET WITHOUT ANY HEADLINE.
HIGH PRESSURE WILL BUILD OVER THE LOWER LAKES LATER MONDAY AND
MONDAY NIGHT WITH DIMINISHING WIND AND WAVES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR
NYZ001>006-010-011-013-014-019-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR
LOZ042>044.
&&
$$
SYNOPSIS...HITCHCOCK/RSH
NEAR TERM...APFFEL/HITCHCOCK/RSH
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...HITCHCOCK/RSH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
426 AM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 325 AM MONDAY...
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. GIVEN WARM ADVECTION OVERNIGHT...EXPECT LOWS IN THE MID
TO UPPER 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 425 AM MONDAY...
24-HR TAF PERIOD:
A BACKDOOR COLD FRONT WILL APPROACH THE AREA FROM THE NORTH THROUGH
12Z...THEN PROGRESS SOUTHWEST THROUGH CENTRAL NC TODAY. THE FRONT IS
EXPECTED TO STALL OUT OVER WESTERN NC/SC LATER THIS AFTERNOON AND
EVENING. EXPECT A POTENTIAL FOR MVFR CONDITIONS ASSOC/W ISOLD
CONVECTION THIS MORNING (BETWEEN ROUGHLY 09-15Z) AND A PERIOD OF
MVFR CEILINGS ALONG/BEHIND THE BACKDOOR COLD FRONT BETWEEN 13-19Z.
OTHERWISE...EXPECT VFR CONDITIONS TO PREDOMINATE. A ~35 KT WESTERLY
LOW-LEVEL JET AT 1500-2000 FT MAY ALLOW FOR MARGINAL LOW-LEVEL WIND
SHEAR BETWEEN 09-12Z THIS MORNING. HOWEVER...THE PRESENCE OF A 5-10
KT SOUTHWESTERLY BREEZE AT THE SURFACE SUGGESTS IT MAY BE DIFFICULT
FOR SUSTAINED LLWS CRITERIA TO BE MET...DESPITE ~30 DEGREES OF
VEERING AS WELL. TRANSIENT LOW-LEVEL WIND SHEAR WILL BE POSSIBLE IF
SURFACE WINDS BECOME LIGHT/VARIABLE OR CALM...PARTICULARLY IN THE
WAKE OF ANY ISOLD SHOWER ACTIVITY THAT MAY TEMPORARILY CREATE A
STABLE COLD NEAR-SURFACE COLD POOL. SOUTHWESTERLY WINDS AT 5-10 KT
AT THE BEGINNING OF THE TAF PERIOD WILL BECOME WESTERLY BY
12Z...THEN VEER TO THE NORTH/NORTHEAST AND INCREASE TO 10-15 KT IN
ASSOC/W THE BACKDOOR COLD FRONTAL PASSAGE BETWEEN ROUGHLY 13-16Z.
WINDS WILL BECOME EASTERLY AT ~5 KT OR LIGHT/ VARIABLE FROM SUNSET
THIS EVENING THROUGH SUNRISE TUE MORNING.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
THERE IS A GOOD PROBABILITY THAT MVFR CEILINGS WILL OVERSPREAD THE
AREA FROM SW-NE OR W-E AS THE STALLED FRONT LIFTS BACK THROUGH
CENTRAL NC AS A WARM FRONT DURING THE DAY TUE. A PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE EARLY WED MORNING (06-12Z) IN ASSOC/W WARM
ADVECTION UNDER THE NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND
STORMS ARE EXPECTED DURING THE DAY WED IN ADVANCE OF ANOTHER
BACKDOOR COLD FRONT APPROACHING THE AREA FROM THE NORTH. A PROLONGED
PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN
ASSOC/W LOW-LEVEL NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED
COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
345 AM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 325 AM MONDAY...
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 215 AM MONDAY...
24-HR TAF PERIOD:
A BACKDOOR COLD FRONT WILL APPROACH THE AREA FROM THE NORTH THROUGH
12Z...THEN PROGRESS SOUTHWEST THROUGH CENTRAL NC TODAY. THE FRONT IS
EXPECTED TO STALL OUT OVER WESTERN NC/SC LATER THIS AFTERNOON AND
EVENING. EXPECT A POTENTIAL FOR MVFR CONDITIONS ASSOC/W ISOLD
CONVECTION THIS MORNING (BETWEEN ROUGHLY 09-15Z) AND A PERIOD OF
MVFR CEILINGS ALONG/BEHIND THE BACKDOOR COLD FRONT BETWEEN 13-19Z.
OTHERWISE...EXPECT VFR CONDITIONS TO PREDOMINATE. SOUTHWESTERLY
WINDS AT 5-10 KT AT THE BEGINNING OF THE TAF PERIOD WILL BECOME
WESTERLY BY 12Z...THEN VEER TO THE NORTH/NORTHEAST AND INCREASE TO
10-15 KT IN ASSOC/W THE BACKDOOR COLD FRONTAL PASSAGE BETWEEN
ROUGHLY 13-16Z. WINDS WILL BECOME EASTERLY AT ~5 KT OR LIGHT/
VARIABLE FROM SUNSET THIS EVENING THROUGH SUNRISE TUE MORNING.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
THERE IS A GOOD PROBABILITY THAT MVFR CEILINGS WILL OVERSPREAD THE
AREA FROM SW-NE OR W-E AS THE STALLED FRONT LIFTS BACK THROUGH
CENTRAL NC AS A WARM FRONT DURING THE DAY TUE. A PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE EARLY WED MORNING (06-12Z) IN ASSOC/W WARM
ADVECTION UNDER THE NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND
STORMS ARE EXPECTED DURING THE DAY WED IN ADVANCE OF ANOTHER
BACKDOOR COLD FRONT APPROACHING THE AREA FROM THE NORTH. A PROLONGED
PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN
ASSOC/W LOW-LEVEL NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED
COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
152 AM EDT MON APR 2 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA TODAY AND MAY
BRING AN ISOLATED SHOWER OR THUNDERSTORM. UNSETTLED CONDITIONS WILL
RETURN BY MID WEEK AS A LOW PRESSURE SYSTEM APPROACHES THE EASTERN
CAROLINAS. COOL AND DRY HIGH PRESSURE IS EXPECTED TO BUILD INTO THE
REGION LATE IN THE WEEK AND PERSIST INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1030 PM SUNDAY...CLUSTER OF SHOWERS AND ISOLATED TSTMS
ASSOCIATED WITH AN UPPER LEVEL VORT...HAS NEARLY TRACKED ACROSS THE
STATE OF SC THIS EVENING BEFORE FINALLY ENCOUNTERING A STABILIZING
ATMOSPHERE AFTER SUNSET. IT IS ALSO ENCOUNTERING A SHALLOW STABLE
LOW LEVEL MARINE AIR BEHIND A SEA BREEZE THAT TRACKED A GOOD 50
MILES INLAND BEFORE THE CIRCULATION WAS INTERRUPTED BY YOU GUESS
IT...SUNSET. OVERALL...CONVECTION HAS NEARLY DIED OUT ENTIRELY WITH
ONLY A FEW SHOWERS TEMPORARILY LEFT ACROSS SOUTHERN SC AT THE
MOMENT. HAVE REMOVED ALL POPS FOR THIS EVENING...AND THE OVERNIGHT
PERIOD. CONVECTION DROPPING SOUTHWARD ASSOCIATED WITH A SFC COLD
FRONT WILL LIKELY HOLD OFF UNTIL AFTER SEVERAL HRS AFTER MONDAYS
SUNRISE AT WHICH TIME THE ATM WILL BEGIN TO DESTABILIZE. CURRENT MIN
TEMP FCST LOOKS AOK. NOT EXPECTING FOG TO BE A PROBLEM OVERNITE WITH
A SFC SW-W WIND REMAINING ACTIVE OVERNIGHT. LATEST MIN FCST LOOKS
AOK AND C NO REASON TO ALTER.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...BACK DOOR TYPE COLD FRONT WILL BE ON THE
DOORSTEP OF THE NORTHERN PART OF THE CWA AT THE START OF THE PERIOD.
THIS FRONT WILL DROP SOUTH THROUGH MONDAY IN RESPONSE TO A NORTHERN
STREAM 500MB S/W TROUGH PUSHING SE OFF THE MID-ATLANTIC COAST. TWO
QUESTIONS PERSIST ABOUT THIS FROPA...WILL IT PUSH ALL THE WAY
THROUGH THE CWA...AND WILL IT BE ASSOCIATED WITH TSTMS.
AS THE FRONT PUSHES SOUTH...IT WILL ENCOUNTER THE LEADING EDGE OF A
STRONG UPPER RIDGE BUILDING EASTWARD FROM THE GREAT PLAINS. RIDGES
TEND TO WIN THESE PLACEMENT BATTLES...BUT GUIDANCE CONTINUES TO
INSIST THAT FROPA WILL TAKE PLACE THROUGH THE ENTIRE CWA. S/W
DRIVING IT IS FAIRLY POTENT...AND RIDGE IS ONLY BEGINNING TO MOVE
EAST...SO WILL CONTINUE TO SHOW FROPA THROUGH THE AREA MONDAY. AT
THE SAME TIME...DECENT CONVERGENCE ALONG THE BOUNDARY INTO RICH
THETA-E AIR SHOULD SUPPORT SOME SHOWERS AND ISOLATED TSTMS. BEST
CHANCE LOOKS TO BE ACROSS SOUTHERN ZONES WHERE HEATING AND HIGHER
PWATS WILL SUPPORT MORE PRECIP...BUT WEAK NVA AT 500MB AND
CONFLUENCE AT JET LEVEL WILL INHIBIT MUCH IN THE WAY OF CONVECTION.
AM COMFORTABLE WITH THE INHERITED SCHC OF TSTMS...BUT EXPECT VERY
LIGHT PRECIP AS EVIDENCED BY HPC QPF OF ONLY A FEW HUNDREDTHS OF AN
INCH.
TEMPS MONDAY WILL BE TRICKY AS WELL...SINCE 850MB TEMPS WILL FALL
THROUGH THE DAY AND THERE COULD BE QUITE A TEMP GRADIENT FROM SW TO
NE. TEMPS ONLY IN THE UPPER 70S FAR NE COASTAL ZONES...RISING INTO
THE UPPER 80S IN THE PEE DEE REGION OF SC. MINS RANGE FROM AROUND 50
FAR NE TO AROUND 60 IN THE SOUTH.
WEAK CAA ON TUESDAY WILL KEEP TEMPS AROUND CLIMO UNDER PARTLY TO
MOSTLY CLOUDY SKY CONDITIONS DUE TO MOISTURE TRAPPED BENEATH THE
FRONTAL INVERSION. COLD FRONT SOUTH OF THE AREA TUESDAY WILL STALL
AND WAVER BACK NORTH...WHILE INCREASING ISENTROPIC LIFT WILL SUPPORT
INCREASING SHOWERS ACROSS SOUTHERN ZONES...BUT ONCE AGAIN WITH
LIMITED QPF. MINS TUESDAY NIGHT STAY ABOVE 60 ACROSS MOST OF THE
AREA AS HIGH PRESSURE DRIFTS OFFSHORE CREATING WARM SOUTHERLY FLOW
AND CLOUD COVER.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...MAIN FOCUS FOR THE EXTENDED
REMAINS ON THE MID LEVEL SYSTEM NOW MOVING/DIGGING ACROSS THE
WESTERN U.S. AND ITS MOVEMENT/EVOLUTION THROUGH LATE WEEK. HPC
CONTINUES TO FAVOR THE ENSEMBLE MEAN OF THE ECMWF WHICH IS SLIGHTLY
MORE AMPLIFIED AND SLOWER AND THE GFS MEAN. I HAVE MADE FEW
ADJUSTMENTS IN POPS OTHER THAN TO DECREASE INCREMENTALLY VALUES FOR
THURSDAY AS THE MID LEVEL RIDGE AMPLIFIES ACROSS THE AREA JUST
BEFORE THE MAIN SYSTEM MOVES ACROSS EARLY FRIDAY. FOR WEDNESDAY A
BACKDOOR FRONT CONTINUES TO WARRANT CHANCE POPS. SATURDAY AND SUNDAY
REMAIN DRY FOR NOW.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...KLTX VWP IS MEASURING 40 KT WIND FROM THE WSW AS OF 05Z.
WINDS JUST OFF THE DECK INCREASE RAPIDLY AND WILL INCLUDE WIND SHEAR
IN THE FORECAST WITH THESE HIGHER WINDS MIXING OUT AROUND SUNRISE.
CEILINGS AND VISIBILITIES ARE EXPECTED TO REMAIN IN THE VFR CATEGORY
THROUGH THE TAF PERIOD. HOWEVER...THERE IS A RISK FOR AN IFR STRATUS
LAYER TO DEVELOP THROUGH 09Z OR SO AT THE COAST. SW WINDS WILL SHIFT
TO THE NORTH LATE MORNING AND THIS AFTERNOON FROM N TO S AS A COLD
FRONT SINKS SOUTHWARD ACROSS THE TERMINALS. THERE MAY BE ISOLATED
CONVECTION ALONG AND AHEAD OF THE FRONT...WITH THE RESULTANT ADDING
ANOTHER BOUNDARY. HAVE DECIDED TO ADD VCSH TO THE TAFS...NOT
CONFIDENT ENOUGH TO ADD A TEMPO AT THIS TIME. DEVELOPING GUSTY NORTH
WINDS WILL CONTINUE THROUGH THE AFTERNOON...DIMINISHING DURING THE
EVE AS THEY VEER TO THE NORTHEAST.
EXTENDED OUTLOOK...LOW CONFIDENCE SHOWERS/ISOLATED THUNDERSTORMS
MONDAY NIGHT AND TUESDAY. SCATTERED CONVECTION POSSIBLE WEDNESDAY
WITH A BETTER CHANCE FOR PRECIP ON THURSDAY INTO EARLY FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SUNDAY...WINDS CONTINUE TO VEER TO THE SW LATE THIS
EVENING AND HAVE INCREASED TO 10-15 KT. PROGGED BY HRRR AND NAM
MODELS...SW-W WINDS WILL FURTHER INCREASE OVERNIGHT TO 15 TO 20 KT
THRU THE PRE-DAWN HRS OF MONDAY. WIND DRIVEN WAVES WILL DOMINATE
SIGNIFICANT SEAS WITH SEAS BUILDING TO 2 TO 4 FT ...EXCEPT 3 TO 5 FT
ACROSS THE WATERS OFF CAPE FEAR SOUTH TO LITTLE RIVER INLET DUE TO
THE LONGER SW-W FETCH. SCEC THRESHOLDS MAY BE MET FOR THE JUST THE
AFOREMENTIONED WATERS AND WILL MONITOR FOR POSSIBLE ISSUANCE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...COLD FRONT CROSSES THE WATERS DURING
MONDAY...TURNING WINDS FROM THE WEST AT 10-15 KTS EARLY...TO THE NE
AT 10-15 KTS BY MONDAY NIGHT. THIS TRANSITION WILL OCCUR FIRST
ACROSS THE NORTHERN WATERS...AND LATER IN THE DAY ACROSS THE SOUTH.
WAVE SPECTRUM WILL CONSIST OF A LOW AMPLITUDE ESE 1FT/9SEC SWELL AND
A BUILDING 3-4FT/5SEC NE WIND WAVE. THESE WILL COMBINE TO CREATE
SEAS OF 2-3 FT...SLIGHTLY LOWER IN THE SHADOWED REGION SW OF FRYING
PAN SHOALS. HIGH PRESSURE DRIFTS OFFSHORE TUESDAY ALLOWING WINDS TO
SLOWLY VEER TO THE SOUTH AS RETURN FLOW SETS UP. SPEEDS OF ONLY
AROUND 10 KTS WILL PRODUCE CONTINUED 2-3 FT SEAS...COMPRISED OF A
ENE WIND CHOP EARLY...BECOMING A SW WIND CHOP LATE.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...EXPECT A SOUTHWEST FLOW INITIALLY AS BERMUDA
HIGH PRESSURE PREVAILS AND A FRONT LURKS OFF TO THE NORTH WITH A
PIEDMONT TROUGH AS WELL. THE FRONT MOVES ACROSS LATE WEDNESDAY INTO
THURSDAY MORNING AS MOST IF NOT ALL WATERS WILL SEE NORTHEASTERLY
WINDS BY 1200 UTC THURSDAY. UNCERTAINTY REMAINS FOR THE REMAINDER OF
THE FORECAST AS SURFACE PRESSURE PATTERN SHOWS LOW PRESSURE DROPPING
TO THE SOUTH AND WINDS TURNING TO THE EAST. GOOD THING IS THE
STRENGTH OF THE LOW SHOULD REMAIN RELATIVELY WEAK SO DO NOT
ANTICIPATE ANY HEADLINES. THE STRONGEST WINDS SHOULD OCCUR WEDNESDAY
WITH 10-15 KNOTS. WAVEWATCH SEAS ARE REFLECTIVE OF THE WINDS AT
LEAST INITIALLY. HAD TO SCALE BACK LATER IN THE PERIOD BUT OVERALL
SEAS REMAIN BELOW FLAG CRITERIA AS WELL.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...RJD/HDL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
327 AM CDT MON APR 2 2012
.SHORT TERM...MAIN CHALLENGE WILL BE PRECIP/THUNDER CHANCES TODAY.
00Z MODELS INITIALIZED WITH MINIMAL ERRORS. GFS/ECMWF/GEM ALL
AGREE WITH TIMING WITH NAM FASTER. WILL SIDE WITH THE SLOWER
SOLUTIONS.
UPPER TROUGH ACROSS THE ROCKIES WILL BE NEAR THE EASTERN FA BY 12Z
TUESDAY. A COLD FRONT WILL SLOWLY PROPAGATE FROM WEST TO EAST
THROUGH THE REGION. MODELS INDICATE WEAK TO MODERATE INSTABILITY
(850MB CAPE AROUND 1000 J/KG) WILL ADVECT INTO THE SOUTHERN FA BY
12Z THIS MORNING...WITHIN WARM AIR ADVECTION REGIME. HRRR SUGGESTS
THUNDER TO DEVELOP ACROSS AN AREA FROM SOUTHEAST NORTH DAKOTA INTO
THE BEMIDJI AREA. DEEP LAYER SHEAR IS MARGINAL...BUT AN ISOLATED
SEVERE HAIL REPORT IS POSSIBLE. THIS ACTIVITY DIMINISHES BY
AFTERNOON AS 850MB FLOW WEAKENS. A BAND OF SHOWERS (MAYBE ISOLD
THUNDER) WILL LIKELY DEVELOP ALONG AN 850MB BAROCLINIC ZONE BY
NOON TO THE NORTH OF THE MORNING CONVECTIVE ACTIVITY (AROUND AN
AREA FROM VALLEY CITY TO HALLOCK). FOLLOWING GFS/ECMWF/GEM 850MB
FRONTOGENESIS...THIS BAND OF SHOWERS SHOULD GRADUALLY PROPAGATE TO
THE EAST/SOUTHEAST INTO THE OVERNIGHT HOURS. TIMED 60 POPS
ACCORDING TO THIS TIMING. THIS BAND OF FRONTOGENESIS WILL INTERACT
WITH PWATS 0.75 TO 1.00 INCH. GIVEN THE ABOVE FACTORS THINKING
AREAL QPF 0.50 INCH TO 1.00 INCH. WINDS WILL BECOME NORTH BEHIND
THE COLD FRONT...AND CLOSE TO ADVISORY CRITERIA. GIVEN CURRENT
MODEL 925MB WINDS SPEEDS OF 30-35 KNOTS...THINKING MOST AREAS WILL
BE JUST BELOW ADVISORY CRITERIA. STRONGEST COLD AIR ADVECTION
REMAINS WEST/SOUTH OF THE FA. MAX TEMPS SHOULD REMAIN IN THE 50S
CONSIDERING CONSIDERABLE CLOUD COVER.
RIDGING AFFECT THE REGION FOR THE REMAINDER OF THE PERIOD. THE
AIRMASS WILL CHANGE LITTLE...AND CONDITIONS SHOULD BE SIMILAR
EACH DAY.
.LONG TERM (THURSDAY-SUNDAY)...MODELS IN GOOD AGREEMENT WITH THE
EXTENDED TIME PERIOD AS 500MB RIDGING DOMINATES THE WEATHER
PATTERN OVER THE NORTHERN PLAINS FROM THE MIDDLE TO THE END OF THE
WEEK. AS THE RIDGING SHIFTS EAST SOUTHWESTERLY FLOW DEVELOPS AND
WILL BRING AN INCREASE OF SHOWER ACTIVITY BEGINNING FRIDAY
AFTERNOON. BEST CHC FOR PCPN WILL BE SATURDAY ASSOCIATED WITH
FROPA. TEMPS FOR THE PERIOD TO BE ABOVE NORMAL... WITH COOLER
TEMPS EXPECTED THIS NEXT WEEKEND AS CLOUDS INCREASE WITH CHC POPS.
&&
.AVIATION...MVFR CIGS EXPECTED TO DEVELOP THIS MORNING ALONG AND
EAST OF THE VALLEY. THESE CIGS WILL LIKELY LOWER INTO IFR RANGE BY
AFTERNOON. SCATTERED TSRA EXPECTED TO DEVELOP ALONG A LINE FROM
FARGO TO BEMIDJI AROUND SUNRISE. THIS ACTIVITY SHOULD
DIMINISH BY NOON...BUT A BAND OF SHOWERS WILL LIKELY DEVELOP FROM
VALLEY CITY TO THE NORTHEAST...AND THEN GRADUALLY MOVE EAST
THROUGH THE DAY. CIGS WILL REMAIN LOW INTO TONIGHT...CLEARING FROM
WEST TO EAST.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG/JK
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
126 AM EDT MON APR 2 2012
.SYNOPSIS...
A COOLER AND DRIER AIR MASS ASSOCIATED WITH HIGH PRESSURE CENTERED
OVER HUDSON BAY WILL BE DIRECTED INTO THE AREA TODAY BEHIND
NORTHERLY WINDS...WHICH WILL BE RATHER GUSTY OVER THE EASTERN HALF
OF THE STATE. THE NEXT CHANCE OF RAIN WILL COME BY LATE TUESDAY
INTO EARLY WEDNESDAY...AS A WEAK AREA OF LOW PRESSURE MOVES
EASTWARD FROM THE OHIO VALLEY ACROSS THE NORTHERN MID-ATLANTIC
STATES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLIPPER LOW OVER SOUTHERN PA LATE THIS EVENING WILL CONTINUE TO
TRACK SE...PASSING OFF THE DELMARVA LATER TONIGHT. REGIONAL RADAR
MOSAIC SHOWING RAIN STILL FALLING ACROSS THE SOUTHERN THIRD OF PA
AT 03Z. HRRR AND RUC BOTH INDICATE THE LAST THE RAIN WILL EXIT
SOUTHERN PA BTWN 05Z-06Z.
CLEARING SKIES SHOULD DEVELOP LATE TONIGHT ACROSS CENTRAL AND
SOUTHERN PA...AS MUCH DRIER AIR MASS OVERSPREADS THE STATE. LOW
LVL MOISTURE TRAPPED BENEATH SUBSIDENCE INVERSION WILL LIKELY KEEP
STRATO-CU LOCKED IN OVR THE N MTNS...WHILE DOWNSLOPING NORTHERLY
FLOW YIELDS MCLEAR SKIES SOUTH OF I-80 BY DAWN. LIGHT WINDS WILL
BECOME GUSTY FROM THE NW OVR THE ENTIRE REGION TONIGHT...AS
CLIPPER LOW INTENSIFIES OFF THE E COAST. THESE GUSTY WINDS HAVE
ALREADY DEVELOPED ACROSS THE NW MTNS AS OF 03Z AND BUFKIT
SOUNDINGS SUPPORT GUSTS TO ARND 20KTS LATER TONIGHT ACROSS MUCH OF
SOUTHERN PA.
POST-FRONTAL AIR MASS WILL BE ONLY SEASONABLY COOL AND AN ACTIVE
NW WIND WILL KEEP ATMOS MIXED OVERNIGHT...SO LOW TEMPS SHOULD
ACTUALLY BE A BIT ABV SEASONAL NORMS...RANGING FROM THE L30S NW
MTNS...TO ARND 40F SOUTH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
MONDAY WILL BE BREEZY...DRIER AND A LITTLE COOLER AS NORTHERLY
WINDS SPREAD IN BEHIND THE DEPARTING FRONT AND THE HIGH TO OUR
NORTH BEGINS NOSING DOWN. ANY EARLY CLOUDS WILL YIELD TO PLENTY OF
SUNSHINE BY MID TO LATE MORNING. GEFS 850 TEMPS SUPPORT HIGH
TEMPS IN THE 50S. DESPITE THE DRY AIR AND GUSTY WINDS OVR EASTERN
PA ON MONDAY...THINKING IS TODAY/S RAINFALL WILL DAMPEN FINE FUELS
ENOUGH TO PRECLUDE A SIGNIFICANT WILDFIRE THREAT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
BROAD UPPER TROFFING ALONG THE APPALACHIANS AT THE START OF THE
PERIOD...AN EXTENSION OF A LARGE UPPER VORTEX OVER ERN CANADA...IS
FORECAST TO WEAKEN AS THE MAIN SHORT WAVE TROF SWINGS
OFFSHORE...ALLOWING HEIGHTS TO RISE TEMPORARILY ACROSS PA AND INTO
NEW ENGLAND. TROFFING WILL RETURN MIDWEEK AS ENERGY IN THE
ACTIVE NRN STREAM JET DROPS DOWN THE EAST SIDE OF THE UPPER RIDGE
OVER THE CENTRAL U.S.
THIS CENTRAL U.S. UPPER RIDGE/OMEGA BLOCK PATTERN WILL MAKE ONLY
SLOW PROGRESS EAST AS IT IS BOMBARDED BY NUMEROUS NRN AND SRN
STREAM WAVES AS WELL AS BEING IMPEDED BY THE ERN CANADA UPPER LOW.
THIS WILL SERVE TO KEEP PA IN SOME DEGREE OF NW FLOW THROUGH THE
REMAINDER OF THE LONG TERM PD. WHILE THIS WILL HELP SUPPORT THE DRY
FORECAST...ANY WAVES IN THE FLOW COULD BECOME FLIES IN THE OINTMENT
SO TO SPEAK. THOUGH AT THIS POINT NO OPPORTUNITIES FOR SIGNIFICANT
RAINFALL APPEAR LIKELY. THE NW FLOW WILL ALSO BRING COOLER...OR
RATHER CLOSE TO NORMAL...OR EVER SO SLIGHTLY BELOW NORMAL TEMPS FOR
THUR AND FRI BEFORE A WARM UP FOR NEXT WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
WEAK FRONTAL SYSTEM AND WAVE OF LOW PRES CURRENTLY PUSHING SOUTH
OF THE PA/MD LINE AS OF 05Z. COSPA DATA DEPICTS SHOWERS EXITING
SRN PA BY 06Z. IR SATL SHOWS LOW CLOUDS MOVG SWD FROM NY COVERING
MUCH OF CENTRAL PA WITH CIGS GENERALLY IN THE MVFR CATG BTWN
1500-3000KFT AGL...WITH LCL CIGS BLW 1KFT AGL ACRS PTNS OF THE
ALLEGHENIES/LAUREL HIGHLANDS. THE REMAINDER OF THE PRE-DAWN HOURS
WILL BE CLOUDY WITH MAINLY MVFR CIGS AND PATCHY DZ...AS MSTR
PROFILES DRY OUT RAPIDLY ALOFT.
A DRIER NLY FLOW ASSOC WITH CANADIAN HIGH PRES SHOULD BRING
CLEARING TO THE NRN TIER BTWN 10-11Z AND 11-13Z IN THE CNTRL
AIRFIELDS BASED ON LINEAR EXTRAPOLATION OF BACK EDGE OF LOW CLOUD
DECK CROSSING LAKE ONTARIO. EXPECT DECREASING CLOUDS EARLY THIS
MORNING SHORTLY AFT SUNRISE WITH CLR SKIES AND WDSPRD VFR BY MID-
DAY. ANTICIPATE THE NLY WINDS TO INCREASE FROM MID MORNING THROUGH
THE AFTN ESPECIALLY OVR ERN SXNS WITH GUSTS BTWN 25-30KTS. WINDS
WILL SUBSIDE AFTER DARK AS HIGH PRES BUILDS OVER PA.
OUTLOOK...
TUE...VFR/MVFR WITH SHOWERS LATE.
WED...MVFR WITH A CHC OF SHOWERS EARLY...OTHERWISE VFR.
THU-FRI...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/STEINBUGL
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
408 AM CDT MON APR 2 2012
.DISCUSSION...
A WEAK UPPER LEVEL CIRCULATION WAS SPINNING NORTH OF MATAGORDA BAY
THIS MORNING. THIS FEATURE WILL SLOWLY MOVE NORTH NORTHEAST INTO
NORTHWEST LOUISIANA BY EVENING. ANOTHER UPPER LEVEL DISTURBANCE
OVER SOUTH TEXAS IS TRIGGERING SHOWERS AND THUNDERSTORMS OVER
SOUTH TEXAS AND THE MIDDLE TEXAS COAST. THIS DISTURBANCE IS MOVING
EAST AND THE ASSOCIATED PRECIP SHOULD BEGIN TO MOVE OVER PARTS OF
THE CWA BY 5 AM. MODELS ARE NOT DOING A GREAT JOB WITH THE SMALL
SCALE DETAILS AND SHORT TERM GUIDANCE HAS INITIALIZED POORLY. THAT
SAID...FEEL THE DEEPER MOISTURE WILL REMAIN EAST OF THE UPPER
CIRCULATION NORTH OF MATAGORDA BAY. BEST RAIN CHANCES SHOULD LIE
TO THE EAST OF THE I-45 CORRIDOR AND SOUTH OF HWY 105. THE SYSTEM
WILL STRENGTHEN THIS AFTERNOON AND HEAVIER RAIN WILL BEGIN TO
DEVELOP AND HEAD TOWARD LOUISIANA. IF THE SYSTEM TRACKS FURTHER
WEST THAN CURRENTLY FCST...SOME OF THE MORE ORGANIZED HEAVIER RAIN
WILL ALSO SHIFT WEST AND INTO HOUSTON.
LOOKING SOUTH...THE LINE OF STORMS OVER SOUTH TEXAS IS MAKING
STEADY PROGRESS EAST THIS MORNING. SHORT TERM GUIDANCE IS WELL
BEHIND THE CURVE WITH THE PLACEMENT OF THE PRECIP. THE 06Z RUC IS
BEGINNING TO CATCH ON AND IT BRINGS A WEAK LINE OF SHOWERS INTO
THE REGION...WEST OF I-45 BY 15Z. THE 4KM WRF SEEMS TO BE DOING A
GOOD JOB WITH THIS AREA OF CONVECTION (COMPLETELY MISSED THE
PRECIP OVER LOUISIANA). THE WRF BRINGS THIS LINE OF STORMS
INTO AND ACROSS SOUTHEAST TEXAS THIS MORNING...EXITING THE THE
REGION BY 19Z. WILL HEDGE MY BETS AND GO WITH CHANCE POPS SOUTH
AND SLIGHT CHANCE NORTH. WILL WATCH TRENDS AND POPS MAY BE NUDGED
UPWARD LATER THIS MORNING IF TRENDS WARRANT. SPC HAS OUTLOOKED THE
EXTREME NORTHERN PORTION OF SE TX IN SLIGHT RISK FOR THIS
AFTERNOON AND EVENING. FCST SOUNDINGS SHOW A GREAT DEAL OF
INSTABILITY (CAPE ABOVE 3000 AND LI`S AROUND -10)...BUT THERE IS
STILL SOME WEAK CAPPING TO OVERCOME. THE PROBABILITY OF OCCURRENCE
SHOULD REMAIN SLIGHT BUT THERE IS SOME POTENTIAL FOR STORMS TO
PRODUCE DAMAGING WINDS AND LARGE HAIL. THE THREAT AREA IS NORTH OF
A BRENHAM TO HUNTSVILLE TO CLEVELAND LINE.
THERE SHOULD BE A BREAK IN THE PRECIP TONIGHT AS THE MORNING
SYSTEM IS EAST OF THE REGION AND THE NEXT STRONG UPPER LEVEL
SYSTEM IS STILL OVER NEW MEXICO. THE UPPER LEVEL LOW OUT WEST WILL
MOVE NORTHEAST ON TUESDAY. NAM AND GFS DIFFER WITH MOISTURE
PROFILES BUT CAPPING IS WEAK AND UPPER LEVEL WINDS BECOME
INCREASINGLY DIVERGENT. WILL GO WITH HIGH END CHANCE POPS FOR
TUESDAY/TUES NIGHT. NOT SURE WHEN THINGS WILL CLEAR. THE
ECMWF...NAM AND CANADIAN HOLD ONTO THE PRECIP THROUGH WEDNESDAY
MORNING WHILE THE GFS CLEARS THINGS OUT RATHER QUICKLY. PREFER THE
SLOWER CLEARING SINCE THE DRY LINE/WEAK FRONT NEVER REALLY CLEARS
THE COAST. THE UPPER LEVEL LOW WILL BE EAST OF THE REGION ON
THURSDAY AND AN UPPER LEVEL RIDGE WILL BEGIN TO AMPLIFY OVER THE
SOUTHERN PLAINS. PRECIP SHOULD REMAIN NORTH AND WEST OF THE REGION
THURSDAY THROUGH SATURDAY WITH ANOTHER WARM UP UNDERWAY. MAX TEMPS
TOWARD THE END OF THE WEEK WILL BE BACK INTO THE MID/UPPER 80S. 43
&&
MARINE...
AS AN UPPER LOW MOVES ACROSS THE INLAND AREAS...THUNDERSTORMS WILL
BE POSSIBLE TODAY OVER THE BAYS AND COASTAL WATERS. ALTHOUGH THE
FORECAST MODELS DIFFERED...THERE WAS ENOUGH SIMILARITIES TO SUGGEST
MODERATE ONSHORE WINDS WILL AFFECT THE MARINE AREAS TODAY THROUGH
TUESDAY. A COLD FRONT SHOULD APPROACH THE COAST FROM THE NORTHWEST
LATE TUESDAY AND EARLY WEDNESDAY MORNING. FOR NOW IT APPEARS THAT
THE FRONT MAY WELL STAY INLAND OR MOVE JUST OFFSHORE BEFORE
RETURNING BACK TO THE NORTH LATE WEDNESDAY AND THURSDAY. AM
EXPECTING ONSHORE WINDS TO THEN RETURN AND PERSIST THROUGH THE END
OF THE WEEK.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 83 70 80 64 82 / 20 20 50 50 10
HOUSTON (IAH) 84 71 83 67 85 / 30 20 50 50 20
GALVESTON (GLS) 81 73 81 71 81 / 40 20 50 50 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1130 PM CDT SUN APR 1 2012
.DISCUSSION...
SEE AVIATION FOR 06Z TAFS.
&&
.AVIATION...
THE MODERATE PRESSURE GRADIENT ACROSS SOUTH CENTRAL TEXAS WILL
INCREASE THROUGH MONDAY...IN ADVANCE OF A STORM SYSTEM THAT
WILL BRING INCREASING CHANCES OF RAIN LATE MONDAY THROUGH
TUESDAY. ISOLATED SHRA AND TSRA WILL CONTINUE OVER THE
SOUTHWEST TO SOUTH PART OF SOUTH CENTRAL TEXAS FOR THE
NEXT FEW HOURS. CIGS WILL CONTINUE TO FORM AROUND 1 THSD
TO 2 THSD FT FROM KAUS TO KSAT AND VCNTY OF KDRT AROUND
OR AFTER 09Z TONIGHT. CIGS OF 500 TO 900 FT OVC ARE POSSIBLE
VCNTY OF KAUS TO KSAT FROM 07Z TO 16Z MONDAY. PATCHY FOG MAY
DEVELOP WITH VSBYS 3 TO 6 MILES IN FOG/HAZE. CIGS WILL BECOME
1 THSD TO 2 THSD BKN TO OVC AFTER 16Z MONDAY...AND THEN INCREASE
TO CIGS 3 THSD TO 5 THSD BKN AFTER 19Z MONDAY AFTERNOON.
SOUTH AND SOUTHEAST WINDS NEAR 10 KNOTS WILL PICKUP TO
15 TO 20 KNOTS MONDAY...IN ADVANCE OF A STORM SYSTEM...THAT
WILL BRING INCREASING CHANCES OF SHOWERS OR THUNDERSTORMS TO
SOUTH CENTRAL TEXAS TAF SITES ON MONDAY NIGHT THROUGH TUESDAY.
MVFR CIGS WILL FORM OVER SOUTH CENTRAL TEXAS MONDAY NIGHT AFTER
03Z AROUND 1 THSD TO 2 THSD FT OVC. THE STORM SYSTEM THAT
BRINGS A CHANCE OF SHOWERS AND THUNDERSTORMS LATE MONDAY
THROUGH TUESDAY IS FORECAST TO MOVE TO THE TEXAS PANHANDLE
AND WESTERN OK TUESDAY...AND THEN MOVE EAST LATE TUESDAY THROUGH
WEDNESDAY. AS THE LOW TRACKS EAST...NORTH OF SOUTH CENTRAL TEXAS
TUESDAY NIGHT AND WEDNESDAY...SCATTERED WRAP AROUND CLOUDS COULD
IMPACT THE SOUTH CENTRAL TEXAS TAF SITES...AS MORE PREVAILING WEST
TO NORTHWEST SFC WINDS DEVELOP...IN A PATTERN SIMILAR TO THE
WEATHER IN MARCH.
&&
.PREV DISCUSSION... /ISSUED 906 PM CDT SUN APR 1 2012/
UPDATE...
RAISED POPS THROUGH 06Z OUT WEST.
DISCUSSION...
STORMS WHICH ORIGINATED EARLIER THIS AFTERNOON ACROSS THE
SERRANIAS DEL BURRO HAVE MADE GOOD EASTWARD PROGRESSION OVER THE
LAST FEW HOURS INTO THE RIO GRANDE PLAINS. THE STRONGEST
THUNDERSTORMS IN THIS COMPLEX HAVE PRODUCED SMALL HAIL (PEA TO
NEAR HALF-INCH)...AND COULD SEE ANOTHER FEW ROUNDS OF HAIL
(POSSIBLY REACHING SEVERE LEVELS) THIS EVENING AS THE STORMS PULSE.
LATEST RUC ANALYSIS SUGGEST THAT THESE STORMS WILL CONTINUE TO
PUSH EASTWARD THROUGH THE NEXT FEW HOURS BEFORE DISSIPATING.
HOWEVER...MODELS TYPICALLY HAVE A HARD TIME WITH MESOSCALE
CONVECTIVE SYSTEMS COMING OFF OF THE MEXICAN MOUNTAINS AS FAR AS
INTENSITY AND LONGEVITY...SO ADDITIONAL UPDATES MAY BE NEEDED.
PREV DISCUSSION... /ISSUED 704 PM CDT SUN APR 1 2012/
DISCUSSION...
SEE UPDATED AVIATION DISCUSSION FOR 00Z TAFS.
AVIATION...
THE PRESSURE GRADIENT WILL BE INCREASING TONIGHT THROUGH MONDAY
ACROSS SOUTH CENTRAL TEXAS...AS SFC LOW PRESSURE CONTINUES TO
INCREASE OVER WEST TEXAS. THIS WILL SET UP A STRONGER LOW LEVEL
JET TONIGHT...AND CAUSE INCREASING LOW CLOUDINESS TONIGHT.
FOR THIS EVENING 5 THSD TO 10 THSD SCT IS EXPECTED...WITH SCT
CLOUDS INCREASING AT OR ABOVE 25 THSD FT. ISOLATED SHRA AND TSRA
ARE POSSIBLE VCNTY OF KDRT THRU 04Z. LATER TONIGHT...CIGS WILL
FORM AROUND 1 THSD TO 2 THSD FT FROM KAUS TO KSAT AROUND OR AFTER
04Z AND VCNTY OF KDRT AROUND OR AFTER 09Z TONIGHT. CIGS OF 500 TO
900 FT OVC ARE POSSIBLE VCNTY OF KAUS TO KSAT FROM 07Z TO 16Z
MONDAY. CIGS WILL BECOME 1 THSD TO 2 THSD BKN TO OVC AFTER 16Z
MONDAY...AND THEN INCREASE TO CIGS 3 THSD TO 5 THSD BKN AFTER 19Z
MONDAY AFTERNOON. SOUTH AND SOUTHEAST WINDS NEAR 10 KNOTS WILL
PICKUP TO 15 TO 20 KNOTS MONDAY...IN ADVANCE OF A STORM
SYSTEM...THAT WILL BRING INCREASING CHANCES OF SHOWERS OR
THUNDERSTORMS TO THE SOUTH CENTRAL TEXAS TAF SITES ON MONDAY NIGHT
THROUGH TUESDAY. THIS STORM SYSTEM IS FORECAST TO MOVE TO THE
TEXAS PANHANDLE AND WESTERN OK TUESDAY...AND THEN MOVE EAST LATE
TUESDAY THROUGH WEDNESDAY. AS THE LOW TRACKS EAST...NORTH OF SOUTH
CENTRAL TEXAS TUESDAY NIGHT AND WEDNESDAY...SCATTERED WRAP AROUND
CLOUDS COULD IMPACT THE SOUTH CENTRAL TEXAS TAF SITES...AS MORE
PREVAILING WEST TO NORTHWEST SFC WINDS DEVELOP...IN A PATTERN
SIMILAR TO THE WEATHER IN MARCH.
PREV DISCUSSION... /ISSUED 622 PM CDT SUN APR 1 2012/
DISCUSSION...
SEE AVIATION FOR 00Z TAFS.
AVIATION...
THE PRESSURE GRADIENT WILL BE INCREASING TONIGHT THROUGH MONDAY
ACROSS SOUTH CENTRAL TEXAS...AS THE SFC LOW PRESSURE CONTINUES
TO INCREASE OVER WEST TEXAS. THIS WILL SET UP A STRONGER
LOW LEVEL JET TONIGHT...AND CAUSE INCREASING LOW CLOUDINESS.
CIGS WILL FORM AROUND 1 THSD TO 2 THSD FT FROM KAUS TO KSAT
AROUND OR AFTER 04Z AND VCNTY OF KDRT AROUND OR AFTER 09Z
TONIGHT. CIGS OF 500 TO 900 FT OVC ARE POSSIBLE VCNTY OF KAUS TO
KSAT FROM 07Z TO 16Z MONDAY. CIGS WILL BECOME 1 THSD TO 2 THSD
BKN TO OVC AFTER 16Z MONDAY...AND THEN INCREASE TO CIGS 3 THSD
TO 5 THSD BKN AFTER 19Z MONDAY AFTERNOON. SOUTH AND SOUTHEAST
WINDS NEAR 10 KNOTS WILL PICKUP TO 15 TO 20 KNOTS MONDAY...IN
ADVANCE OF A STORM SYSTEM...THAT WILL BRING INCREASING CHANCES OF
SHOWERS OR THUNDERSTORMS TO THE SOUTH CENTRAL TEXAS TAF SITES ON
MONDAY NIGHT THROUGH TUESDAY. THIS STORM SYSTEM IS FORECAST TO
MOVE TO THE TEXAS PANHANDLE AND WESTERN OK TUESDAY...AND THEN
MOVE EAST LATE TUESDAY THROUGH WEDNESDAY. AS THE LOW TRACKS EAST...
NORTH OF SOUTH CENTRAL TEXAS TUESDAY NIGHT AND WEDNESDAY...
SCATTERED WRAP AROUND CLOUDS COULD IMPACT THE SOUTH CENTRAL TEXAS
TAF SITES...AS MORE PREVAILING WEST TO NORTHWEST SFC WINDS
DEVELOP...IN A PATTERN SIMILAR TO THE WEATHER IN MARCH.
PREV DISCUSSION... /ISSUED 339 PM CDT SUN APR 1 2012/
DISCUSSION...
WEAK PAIR OF SHORTWAVES WILL MAKE FOR A SLIGHT CHANCE OF
THUNDERSTORMS TONIGHT INTO MONDAY...BUT LIMITED SURFACE FOCUS WILL
MAKE IT DIFFICULT TO HIGHLIGHT AREAS OF CONVECTION INITIATION. ONE
LIKELY AREA OVER THE BURRO MOUNTAINS HAS ALREADY YIELDED
CONVECTION...BUT MODEL FORECAST WINDS SHOW STORM MOTIONS THAT WILL
TAKE A LONG TIME TO REACH THE RIO GRANDE. ISOLATED POPS ARE POSTED
ALONG THE RIO GRANDE WITH A FEW SHOWERS FORMING BENEATH THE CAP
POSSIBLE OVER EASTERN COUNTIES LATE TONIGHT. DEEPENING LOW LEVEL
MOISTURE SHOULD PROMOTE HIGHER RAIN AND THUNDERSTORM POTENTIAL
DURING THE DAY MONDAY AS A LARGE UPPER LOW DRAWS CLOSER.
THE APPROACHING LOW PRESSURE FROM THE WEST WILL BRING A SEVERE
WEATHER POTENTIAL...BUT SOME UNCERTAINTIES ON TIMING AND LOCATION
DUE TO MODELS SHOWING A SLOWING AND WOBBLING TREND. RECENT MODEL
TRENDS SHOW A SLIGHTLY MORE NORTHWARD TRACK WHEN THE LOW FINALLY
CROSSES TX LATE TUESDAY INTO WEDNESDAY. THIS GIVES SOUTH CENTRAL
TEXAS BOTH THE POTENTIAL FOR A SEVERE WEATHER EVENT MONDAY NIGHT
INTO TUESDAY AND ALSO A POTENTIAL TO BE DRY-SLOTTED...OF WHICH
EITHER SCENARIO COULD BE ENHANCED BY A SUBTLE WOBBLE. WILL STICK
WITH GENERIC SEVERE THREATS FOR NOW WITH BEST CHANCE OVER THE NW
HALF LATE MONDAY NIGHT/EARLY TUESDAY MORNING. IF THE DRY SLOT DOES
NOT SCRAPE AWAY TOO MUCH MOISTURE...A SEVERE AND POTENTIAL HEAVY
RAIN EVENT COULD DEVELOP DURING THE DAY TUESDAY BEFORE THE PACIFIC
FRONT PUSHES THROUGH THE I-35 CORRIDOR LATE IN THE DAY.
BASED ON A SPLIT OF MODEL SOLUTIONS WILL ADD A BIT MORE COLD AND
DRY AIR THAN IS SUGGESTED BY THE GFS SOLUTION WHICH MINIMIZES THE
COLD FRONT AND RETURNS MOISTURE QUICKLY BY THURSDAY. WILL PUSH THE
MOISTURE RETURN BACK TO FRIDAY TO ENABLE MORE SEASONAL TEMPS
THURSDAY AND FRIDAY. WILL ALSO LIMIT POPS FOR THE NEXT WEATHER
SYSTEM TO IMPACT THE AREA SATURDAY AND NEXT SUNDAY DUE TO THE MORE
GRADUAL MOISTURE RETURN AND THE PRESENCE OF AN UPPER RIDGE OVER
TX.
FIRE WEATHER...
A GOOD CHANCE OF WETTING RAINS COMBINED WITH NEAR OF ABOVE NORMAL
RAINFALL OVER WESTERN COUNTIES THE PAST 30 DAYS SHOULD LIMIT FIRE
SPREAD POTENTIAL...AS MOST AREAS HAVE NOTED A GOOD GREEN-UP OVER
SOUTH CENTRAL TEXAS. THUS WILL ANTICIPATE ONLY AN ELEVATED FIRE
WEATHER DAY DESPITE STRONG WEST WINDS AND CRITICAL RH VALUES NEAR
THE RIO GRANDE ON TUESDAY. WILL NEED TO LOOK AT THIS AREA IN MORE
DETAIL IN LATER PACKAGES IF FUTURE MODEL RUNS DECREASE THE RAIN
POTENTIAL FOR THE WESTERN COUNTIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 69 84 67 77 60 / 10 20 40 50 20
AUSTIN BERGSTROM INTL AIRPORT 68 84 66 78 60 / 10 20 40 50 20
NEW BRAUNFELS MUNI AIRPORT 66 84 67 80 59 / 10 20 40 50 20
BURNET MUNI AIRPORT 66 83 65 77 57 / 10 20 40 50 20
DEL RIO INTL AIRPORT 67 93 64 86 58 / 10 20 40 20 -
GEORGETOWN MUNI AIRPORT 66 81 65 76 58 / 10 20 40 50 20
HONDO MUNI AIRPORT 67 86 66 79 56 / 40 20 40 40 10
SAN MARCOS MUNI AIRPORT 67 84 67 79 60 / 10 20 40 50 20
LA GRANGE - FAYETTE REGIONAL 69 83 70 80 65 / 10 20 40 50 30
SAN ANTONIO INTL AIRPORT 69 84 68 79 58 / 10 20 40 40 10
STINSON MUNI AIRPORT 68 85 68 80 60 / 10 20 40 40 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...08
SYNOPTIC/GRIDS...25
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
330 AM CDT MON APR 2 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
330 AM CDT MON APR 2 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES THROUGH TUESDAY
AND TEMPERATURES.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ALONG THE WEST COAST OF THE U.S....
TROUGHING SPLITTING INTO TWO FROM WESTERN MONTANA INTO ARIZONA...AND
STRONG RIDGING ACROSS THE ENTIRE MISSISSIPPI RIVER VALLEY NORTH INTO
WESTERN HUDSON BAY. STRONG WARM ADVECTION PATTERN TAKING PLACE UNDER
THE UPPER RIDGE WITH SOUTHWEST 850MB WINDS OF 30-60 KT FROM KANSAS
INTO SOUTHERN MINNESOTA PER PROFILER/VWP DATA. 00Z SOUNDINGS AT MPX
AND ABR SAW THEIR 850MB TEMPS RISE 3C COMPARED TO THEIR PREVIOUS 12Z
ONES...NOW AT 15C AND 20C RESPECTIVELY. TIGHT THERMAL GRADIENT
REMAINS...THOUGH...WITH GRB AND INL REPORTING AROUND 5C AND APX AT
-1C AT 00Z. THE WARM ADVECTION ALOFT PLUS PLENTY OF DRY AIR SEEN ON
THE 00Z MPX AND OAX SOUNDINGS HAS KEPT THE ATMOSPHERE CAPPED TO
CONVECTION. NEAREST CONVECTION IS NEAR DULUTH INTO FAR NORTHERN
WISCONSIN...ON THE NOSE OF THAT 850MB JET. BELOW THE WARM ADVECTION
SEEN AT 850MB...A COOL/DRY LOW LEVEL EASTERLY FLOW CONTINUES...
BETWEEN HIGH PRESSURE SITUATED OVER NORTHEAST ONTARIO AND A SURFACE
WARM FRONT THAT STRETCHES FROM NEAR ABERDEEN SD TO JUST SOUTH OF DES
MOINES IA AND ST LOUIS MO. AN AREA OF STRATUS LEFTOVER FROM
YESTERDAY AFTERNOON IN NORTHERN ILLINOIS HAS ADVECTED ON
EAST-SOUTHEAST WINDS...NOW ENCOMPASSING SOUTHWEST MINNESOTA INTO
NORTH CENTRAL IOWA. TEMPERATURES SO FAR HAVE FALLEN INTO THE MID 40S
TO MID 50S. SOUTH AND WEST OF THE AFOREMENTIONED WARM FRONT...
READINGS ARE IN THE MID TO UPPER 60S.
TODAY AND TONIGHT...WHAT LOOKED LIKE IN PREVIOUS DAYS OF 500MB
HEIGHTS FALLING THROUGHOUT THIS PERIOD NOW IS COMPLETELY REVERSED.
ALL MODELS NOW SHOW THE CURRENT UPPER RIDGE BUILDING OVER THE
FORECAST AREA TODAY AND EVEN INTO THIS EVENING. A LOT OF THIS HAS TO
DO WITH THE WESTERN TROUGH...WHICH IS SPLITTING APART EARLIER AND
THE NORTHERN PORTION ONLY ENDS UP REACHING NORTHWEST MINNESOTA BY
12Z TUESDAY. THE CHANGE SYNOPTICALLY HAS A BIG IMPACT ON THE
FORECAST. FIRST...NOW THAT THE AREA IS UNDERNEATH BUILDING HEIGHTS
AT 500MB INDUCING SUBSIDENCE...A DRIER FORECAST IS ON TAP. HAVE
REMOVED ALL PRECIPITATION CHANCES FOR TODAY AND LOWERED THEM DOWN TO
AT MOST 20 FOR THIS EVENING. THE 02.00Z GFS IS BASICALLY THE ONLY
MODEL THAT SHOWS PRECIPITATION TODAY...WHICH IS A RESULT OF DRIZZLE
BELOW A CAP. THIS SEEMS VERY SUSPECT AND THE GFS HAS BEEN KNOWN TO
OVERDO THESE DRIZZLE SCENARIOS AS SEEN BACK DURING THE UNPRECEDENTED
WARM SPELL IN MARCH. RUC/NAM SOUNDINGS LOOK MORE REPRESENTATIVE.
THERE STILL ARE INDICATIONS FOR PRECIPITATION AFTER 06Z TONIGHT...
ESPECIALLY NORTH OF I-90 WHERE ISENTROPIC LIFT SEEN ON THE 305K
SURFACE CAN INITIATE CONVECTION. NOTE...THOUGH...THE 02.00Z GEM AND
01.12Z ECMWF INITIATE THIS CONVECTION EVEN FARTHER NORTH OVER
NORTHERN WISCONSIN. SINCE THE 02.00Z ECMWF LOOKS MORE LIKE THE
NAM/GFS VERSUS ITS PREVIOUS RUN...HAVE LEFT THE PREVIOUS FORECAST
CHANCES ALONE AFTER 06Z. IF CONVECTION GOES TONIGHT...1-6 KM SHEAR
IS MOSTLY LESS THAN 15 KTS. THEREFORE...ANTICIPATING IT TO BE
DISORGANIZED AND NOT PRESENT MUCH OF A SEVERE THREAT. TEMPERATURES
ARE ANOTHER PROBLEM. HUDSON BAY HIGH PRESSURE LOOKS TO REMAIN
ANCHORED NOW TODAY...CAUSED IN PART BY THE BUILDING UPPER
RIDGING...WHICH HELPS TO MAINTAIN A FEED OF LOWER LEVEL COLD AIR SUB
850MB. FOR THE MOST PART EXPECTING HIGHS TODAY SIMILAR TO THOSE OF
YESTERDAY...THOUGH COLD ADVECTION OCCURRING AT 925MB TOWARDS CENTRAL
WISCONSIN COULD RESULT IN HIGHS A FEW DEGREES COLDER THERE. WITH A
SLOWER PROGRESSION OF THE UPPER RIDGE...AS WELL WITH AN INVERTED
SURFACE TROUGH MOVING WEST TO EAST ACROSS MINNESOTA...HAVE RAISED
LOWS UP DRAMATICALLY WEST OF THE MISSISSIPPI RIVER.
TUESDAY AND TUESDAY NIGHT...THE CHANGES KEEP COMING. MAJORITY OF THE
ENERGY WITH THE NORTHERN PORTION OF THE WESTERN TROUGH LOOKS TO LIFT
INTO NORTHEAST ONTARIO. HOWEVER...A SHORTWAVE EXTENDING
SOUTHWESTWARD IS PROGGED TO MOVE INTO NORTHERN WISCONSIN BY 00Z
WEDNESDAY...THEN DROP SOUTHEAST THROUGH THE AREA TUESDAY NIGHT. THIS
SHORTWAVE IS IMPORTANT AS THERE APPEARS TO BE AN AREA OF LOW TO
MID-LEVEL STRATUS AHEAD OF IT. ONCE THE SHORTWAVE PASSES THEN SKIES
CAN CLEAR OUT. HAVE HAD TO INCREASE CLOUD COVER FOR TUESDAY TO
ACCOUNT FOR THE STRATUS...WHICH IN COMBINATION WITH LOW LEVEL COLD
ADVECTION HAS RESULTED IN LOWERING HIGHS FOR SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN A FEW DEGREES. ON THE OTHER HAND...THE
SLOWER PROGRESSION NOTED IN THE TODAY/TONIGHT DISCUSSION WITH THE
INVERTED TROUGH WILL ALLOW FAR SOUTHWEST WISCONSIN TO WARM UP MORE.
WOULD NOT BE SURPRISED IF TEMPERATURES MAY TRY TO FALL IN THE WAKE
OF THAT INVERTED TROUGH. REGARDING PRECIPITATION CHANCES ON
TUESDAY...FORCING IS VERY WEAK GIVEN LIMITED 500MB HEIGHT FALLS AND
FRONTOGENESIS BEHIND THE PASSING INVERTED TROUGH WEAKENING. IN
FACT...THE 02.00Z NAM/CANADIAN BOTH SUGGEST DRY. THEREFORE...CHANCES
ON TUESDAY ARE ONLY 20 PERCENT...AND CONFINED TO THE MORNING. LOWS
TUESDAY NIGHT ARE KIND OF TRICKY. THE 02.00Z NAM SUGGESTS THE LOW TO
MID LEVEL STRATUS REALLY DOES NOT CLEAR OUT...PARTICULARLY ALONG AND
SOUTH OF I-90. HOWEVER..THE 02.00Z GFS/CANADIAN/ECMWF ARE ALL
CLEARING SKIES OUT. HAVE CONSIDERED THE NAM AN OUTLIER FOR NOW AND
HAVE KEPT THE PREVIOUS FORECAST AND MAJORITY CONSENSUS OF CLEARING
SKIES. ANOTHER PROBLEM IS THAT THE EAST WINDS LOOK A LITTLE STRONGER
BECAUSE OF THE HIGH PRESSURE AREA BUILDING IN ONLY REACHING NORTHERN
MINNESOTA. IN THE END...KEPT LOWS PRETTY CLOSE TO THE PREVIOUS
FORECAST. LOOKS LIKE POTENTIAL EXISTS FOR FREEZE CONDITIONS NORTH OF
I-94. NO FROST ANTICIPATED...THOUGH...GIVEN DEWPOINTS EXPECTED TO
FALL INTO THE 20S AND WINDS STAYING UP.
WEDNESDAY AND WEDNESDAY NIGHT...A COUPLE OF BATTLING FEATURES ARE
FORECAST DURING THIS PERIOD. THE SOUTHERN END OF THE CURRENT WESTERN
TROUGH IS PROGGED TO CLOSE OFF INTO AN UPPER LOW...THEN LIFT THROUGH
KANSAS AND MISSOURI DURING THIS PERIOD. MEANWHILE...WE HAVE THAT
HIGH PRESSURE AREA BUILDING IN FROM NORTHWEST MINNESOTA...WHICH ENDS
UP CONSOLIDATING WITH A CANADIAN HIGH DROPPING DOWN INTO NORTHERN
ONTARIO. DRY AIR ASSOCIATED WITH THIS SURFACE HIGH PLUS UPPER
RIDGING NORTH AND NORTHEAST OF THE UPPER LOW SHOULD BE SUFFICIENT TO
HOLD OFF ANY PRECIPITATION FROM COMING INTO THE FORECAST AREA. COULD
SEE A FEW MID/HIGH CLOUDS TRY TO APPROACH NORTHEAST IOWA...BUT
ANTICIPATING MOST CLOUDS TO STAY SOUTH OF THE AREA TOO. WITH PLENTY
OF SUN AND 850MB TEMPS OF 2-4C...SHOULD SEE TEMPERATURES CLIMB INTO
THE LOW 60S. BETTER 925-850MB COOLING COMES IN WEDNESDAY NIGHT ON
EASTERLY WINDS...LIKELY WITH THAT CANADIAN HIGH COMING DOWN. A
SUSTAINED 5 TO 10 MPH WIND LOOKS LIKELY WEDNESDAY NIGHT...WHICH
SHOULD HELP TEMPERATURES FROM PLUMMETING TOO MUCH. STILL...READINGS
IN THE 30S ARE EXPECTED...COOLEST IN CENTRAL WISCONSIN CLOSER TO THE
COLD ADVECTION.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
330 AM CDT MON APR 2 2012
FOCUS OF THE LONG TERM FORECAST IS ON DEEP TROUGHING THAT IS ALONG
THE WEST COAST THURSDAY MORNING. UPPER RIDGING DOWNSTREAM OF THE
TROUGH SHOULD STAY NEAR OR OVER THE FORECAST AREA THROUGH FRIDAY
EVENING...MAINTAINING DRY CONDITIONS. THURSDAY INTO THURSDAY NIGHT
WILL LIKELY BE THE COOLEST PERIOD AS THE CANADIAN HIGH SLIDES DOWN
INTO EASTERN WISCONSIN ON THE EAST SIDE OF THE UPPER RIDGE. IF THERE
IS GOING TO BE A WIDESPREAD FREEZE...THINKING THURSDAY NIGHT WILL BE
THE BEST SHOT. WISCONSIN AREAS LOOK MOST SUSCEPTIBLE BEING CLOSER TO
THE SURFACE HIGH. WARMING THEN OCCURS FOR FRIDAY INTO SATURDAY AS
THE SURFACE HIGH DEPARTS OFF TO THE EAST. REGARDING THE UPPER
TROUGH...02.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES ARE ALL IN
FAIRLY GOOD AGREEMENT EJECTING IT OUT INTO THE NORTHERN PLAINS ON
SATURDAY. THE MODELS THEN BEGIN TO DIFFER ON SPEED FROM THERE...
RESULTING IN LOWERED CONFIDENCE. IN ANY EVENT...IT APPEARS THE
TROUGH HAS SLOWED DOWN ENOUGH THAT ANY FORCING FOR PRECIPITATION
WILL STAY WEST OF THE FORECAST AREA FRIDAY NIGHT. MODEL CONSENSUS
SUGGESTS THAT A WARM CONVEYOR BELT AHEAD OF THE NORTHERN PLAINS
TROUGH WILL ENTER THE AREA SATURDAY. MEAGER INSTABILITY EXISTS...
JUST ENOUGH TO WARRANT A CHANCE OF THUNDERSTORMS. AFTER
SATURDAY...STAYED WITH THE MODEL CONSENSUS IDEA WHICH WOULD BE FOR A
DRYING TREND. THIS IS DUE TO THE COLD FRONT ASSOCIATED WITH THE
TROUGH MOVING THROUGH THE FORECAST AREA. AGAIN...LOW CONFIDENCE
HERE.
&&
.AVIATION...THROUGH 06Z TUESDAY
1149 PM CDT SUN APR 1 2012
WARM FRONT CURRENTLY RESIDES ACROSS IOWA...WITH BROAD EASTERLY
FLOW TO ITS NORTH OVER THE TAF SITES. SMALL BAND OF STRATUS WAS
SEEN FROM EASTERN IOWA INTO NORTH CENTRAL IOWA...JUST NORTH OF THE
WARM FRONT. 02.02Z RUC 925MB RELATIVE HUMIDITY FIELD DEPICTS THE
LOCATION ACCURATELY...BUT IS OVERDONE WITH THE SPATIAL COVERAGE.
TRENDS IN BOTH THE NAM AND RUC SHOW THIS MOISTURE TO CONTINUE TO
ADVECT NORTHWEST INTO SOUTHERN MINNESOTA THROUGH 12Z. IT LOOKS AS
THOUGH THIS WILL JUST MISS THE KRST TAF SITE...BUT DID CONTINUE TO
INCLUDE SOME SCATTERED STRATUS BETWEEN 08Z-16Z. EASTERLY FLOW WILL
CONTINUE THROUGHOUT THE REMAINDER OF THE PERIOD WITH THE PRESSURE
GRADIENT TIGHTENING MONDAY MORNING. COULD SEE SOME GUSTS TO 20 TO
25 KNOTS AT KRST BETWEEN 16Z-22Z...WITH SLIGHTLY LOWER GUSTS AT
KLSE. ALSO EXPECT VFR CEILINGS TO FORM WITH A BKN040-050KFT DECK
EXPECTED FROM 16Z ON. SURFACE LOW MOVES INTO IOWA BETWEEN 00Z-06Z
MONDAY. ANY CONVECTION THAT FIRES IS EXPECTED TO BE NORTH AND WEST
OF THE TAF SITES THROUGH 06Z THOUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CDT MON APR 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1149 PM CDT SUN APR 1 2012
.SHORT TERM...THROUGH TUESDAY NIGHT
303 PM CDT SUN APR 1 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES MONDAY THROUGH
TUESDAY.
SURFACE ANALYSIS THIS AFTERNOON SHOWS AN AREA OF LOW PRESSURE OVER
WESTERN NORTH AND SOUTH DAKOTA. A WARM FRONT EXTENDS SOUTHEAST
FROM THE LOW INTO CENTRAL ILLINOIS.
WATER VAPOR SATELLITE SHOWS UPPER LEVEL RIDGING OVER THE UPPER
MIDWEST TODAY AS THE NEXT STORM SYSTEM IS WORKING ACROSS THE ROCKY
MOUNTAINS. MODELS CONTINUE TO BE CONSISTENT IS SHOWING THE ENERGY
IN THE TROUGH SPLITTING INTO A PROGRESSIVE NORTHERN STREAM SYSTEM
AND A CUT OFF SOUTHERN STREAM UPPER LEVEL LOW. THE SPLIT OF THE
ENERGY HAS ALREADY STARTED AND WILL CONTINUE THROUGH THE NIGHT.
THE MODELS ALSO HAVE CONTINUED THEIR TREND OF BEING SLOWER PUSHING
THE UPPER LEVEL RIDGE OUT OF THE AREA AND NOW SUGGEST THIS MAY NOT
OCCUR UNTIL MONDAY NIGHT. THERE ALSO IS THE SUGGESTION THAT THE
NORTHERN STREAM SHORT WAVE TROUGH MAY BE A LITTLE BIT STRONGER
THAN PREVIOUSLY INDICATED BUT THE BULK OF THE FORCING FROM THIS
WAVE WILL STILL PASS BY TO THE NORTH. THE 01.12Z GFS ONLY SUGGEST
AROUND 4 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB LAYER
COULD POSSIBLY MOVE ACROSS NORTHERN WISCONSIN TUESDAY.
AS THE WHOLE SYSTEM ADVANCES EAST...THE SURFACE LOW IS EXPECTED TO
REFORM OVER NEBRASKA AND THEN MOVE EAST/NORTHEAST ALONG A COLD
FRONT. AS THE FRONT COMES THROUGH...WEAK FRONTOGENESIS SHOULD
OCCUR ACROSS MINNESOTA AND WISCONSIN CLOSER TO THE UPPER LEVEL
SUPPORT. A BROAD AREA OF WARM AIR ADVECTION WILL OCCUR AHEAD OF
THE COLD FRONT WHICH RESULTS IN 1 TO 3 UBARS/S OF UP GLIDE ON THE
305K ISENTROPIC SURFACE FOR MONDAY AND MONDAY NIGHT. WITH THE
SLOWER ARRIVAL OF THE FORCING...REMOVED THE RAIN CHANCES FOR
MONDAY MORNING AND LIMITED THEM TO THE FAR NORTHWEST SECTIONS OF
THE FORECAST AREA MONDAY AFTERNOON. THE BETTER FORCING THEN
ARRIVES MONDAY NIGHT AHEAD OF THE SHORT WAVE TROUGH WITH THE BEST
CHANCES FOR RAIN ACROSS THE NORTH CLOSER TO WHERE THE PV ADVECTION
WILL BE. NO CHANGES MADE TO THE MONDAY NIGHT FORECAST WITH UP TO A
50 PERCENT CHANCE ACROSS THE NORTH. ADDED IN SOME 20 TO 30 PERCENT
RAIN CHANCES FOR TUESDAY MORNING ACROSS THE SOUTHEAST TO ACCOUNT
FOR THE SLOWER MOVEMENT OF THE SYSTEM AND THE POSSIBILITY OF SOME
LINGERING SHOWERS. REMAIN CONCERNED THAT THE FORECAST REMAINS TOO
FAST BRINGING THIS SYSTEM INTO THE AREA AS THE ECMWF HAS
CONSISTENTLY BEEN SLOWER THAN EITHER THE NAM OR GFS. THE 31.00Z
AND 04.12Z RUNS OF ECMWF CONTINUE THIS TREND AND IF THIS SLOWER
SOLUTION VERIFIES...WOULD NOT BE SURPRISED TO SEE THE ENTIRE AREA
REMAINS DRY MONDAY WITH WARMER TEMPERATURES AS THE WARM AIR OVER
IOWA...NEBRASKA AND MISSOURI GETS DRAWN INTO THE REGION AHEAD OF
THE COLD FRONT. THIS COULD ALSO LEAD TO NEEDING RAIN CHANCES
FARTHER WEST TUESDAY MORNING POSSIBLY LINGERING INTO THE AFTERNOON
ACROSS THE SOUTHEAST.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
303 PM CDT SUN APR 1 2012
ONCE THE EARLY WEEK SYSTEM MOVES THROUGH...HIGH PRESSURE IS
EXPECTED TO SETTLE IN OVER THE REGION FOR THE REMAINDER OF THE
WORK WEEK. THIS HIGH WILL BRING THE POTENTIAL FOR CENTRAL
WISCONSIN TO POSSIBLY DIP INTO THE LOWER TO MIDDLE 30S SETTING UP
THE POTENTIAL FOR SOME FREEZING CONDITIONS OR FROST FORMATION.
ONCE THE HIGH MOVES OFF...THE NEXT SYSTEM WILL APPROACH FOR THE
WEEKEND. THERE CONTINUES TO BE A TREND OF SLOWING THIS SYSTEM DOWN
AND MOST OF THE AREA SHOULD REMAIN DRY FRIDAY NIGHT BEFORE THE
COLD FRONT MOVES IN WITH SOME RAIN CHANCES FOR SATURDAY AND
SATURDAY NIGHT.
&&
.AVIATION...THROUGH 06Z TUESDAY
1149 PM CDT SUN APR 1 2012
WARM FRONT CURRENTLY RESIDES ACROSS IOWA...WITH BROAD EASTERLY
FLOW TO ITS NORTH OVER THE TAF SITES. SMALL BAND OF STRATUS WAS
SEEN FROM EASTERN IOWA INTO NORTH CENTRAL IOWA...JUST NORTH OF THE
WARM FRONT. 02.02Z RUC 925MB RELATIVE HUMIDITY FIELD DEPICTS THE
LOCATION ACCURATELY...BUT IS OVERDONE WITH THE SPATIAL COVERAGE.
TRENDS IN BOTH THE NAM AND RUC SHOW THIS MOISTURE TO CONTINUE TO
ADVECT NORTHWEST INTO SOUTHERN MINNESOTA THROUGH 12Z. IT LOOKS AS
THOUGH THIS WILL JUST MISS THE KRST TAF SITE...BUT DID CONTINUE TO
INCLUDE SOME SCATTERED STRATUS BETWEEN 08Z-16Z. EASTERLY FLOW WILL
CONTINUE THROUGHOUT THE REMAINDER OF THE PERIOD WITH THE PRESSURE
GRADIENT TIGHTENING MONDAY MORNING. COULD SEE SOME GUSTS TO 20 TO
25 KNOTS AT KRST BETWEEN 16Z-22Z...WITH SLIGHTLY LOWER GUSTS AT
KLSE. ALSO EXPECT VFR CEILINGS TO FORM WITH A BKN040-050KFT DECK
EXPECTED FROM 16Z ON. SURFACE LOW MOVES INTO IOWA BETWEEN 00Z-06Z
MONDAY. ANY CONVECTION THAT FIRES IS EXPECTED TO BE NORTH AND WEST
OF THE TAF SITES THROUGH 06Z THOUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
303 PM CDT SUN APR 1 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1005 AM EDT MON APR 2 2012
.SYNOPSIS...
CANADIAN HIGH PRESSURE IS BUILDING INTO THE REGION TODAY INTO
TUESDAY AS DEEPENING LOW PRESSURE OVER THE ATLANTIC MOVES EAST. WEAK
LOW PRESSURE MOVING ACROSS SOUTHEAST CANADA TUESDAY NIGHT WILL
DRAG A TRAILING COLD FRONT ACROSS WEDNESDAY MORNING. CANADIAN HIGH
WILL THEN BUILD BACK IN THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ABUNDANT LOW LEVEL MOISTURE COMBINED WITH SFC HEATING IS ALLOWING
STRATOCUMULUS FIELD TO EXPAND AS IT MOVES SOUTH OUT OF SOUTHERN
NEW ENGLAND AND THE HUDSON VALLEY. SOME SPRINKLES WITH THE BAND
OVER NEW HAVEN THAT WILL MOVE SOUTH OVER CENTRAL LONG ISLAND
BETWEEN 10 AM AND NOON.
LATEST RUC AND 06Z NAM SUGGESTING THAT THIS MOISTURE MIXES OUT AND
SKIES CLEAR THIS AFTERNOON AS PER PREVIOUS FCST.
WIND...CURRENTLY GUSTING TO AROUND 25 MPH...INCREASE THIS AFTN
WITH ADDITIONAL MIXING TO 850 HPA. EXPECT FREQUENT GUSTS IN THE 25
TO 35 MPH RANGE AT WE MIX DOWN APPROX 80% OF THE 850 WIND.
TEMPS ON TRACK FOR LOWER 50S INTERIOR TO MID 50S CITY/COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
DEEP TROUGH AXIS GRADUALLY SLIDES EAST TONIGHT...WITH INTENSE SURFACE
LOW PUSHING OUT TO SEA. RIDGING SURFACE/ALOFT BUILDS IN ON
TUESDAY.
TIGHT GRADIENT AND GUSTY WINDS CONTINUE OVER THE REGION
TONIGHT...WITH SECONDARY SHOT OF CAA IN WAKE OF BACKSIDE SHORTWAVE.
TEMPS EXPECTED TO HOLD NEAR SEASONABLE WITH MIXED LOW-LEVELS DESPITE
CAA AND CLEAR SKIES.
TEMPS ARE EXPECTED TO FALL INTO THE UPPER 20S ACROSS INTERIOR
ZONES LATE TONIGHT. FOR COASTAL AREAS...TEMPS EXPECTED TO DROP
INTO THE LOWER TO MID 30S CITY/COAST. THE COLDEST SURGE OF AIR
SHOULD BE ACROSS EASTERN SECTIONS...WITH SE COASTAL CT HAVING THE
BEST CHANCE OF SUB-FREEZING AIR DRAINING TO THE COAST DOWN THE CT
RIVER VALLEY. AS OF 1 APRIL...WE ARE ISSUING FROST/FREEZE
WATCHES/WARNINGS/ADVISORIES FOR COASTAL SECTIONS. A FREEZE WATCH
FOR SE COASTAL CT IN CURRENTLY IN PLACE.
GUSTY NW WINDS TO START
THE DAY ON TUESDAY...GRADUALLY RELAXING THROUGH THE AFTERNOON.
OTHERWISE MOSTLY SUNNY SKIES...EXCEPT FOR SOME LATE DAY CIRRUS
AHEAD OF A NORTHERN STREAM SHORTWAVE. WITH MODERATING TEMPS ALOFT
AND GOOD MIXING...HIGH EXPECTED TO REBOUND TO ABOVE NORMAL
LEVELS...GENERALLY UPPER 50S INTERIOR TO LOWER 60S CITY/COAST.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
UPPER VORTEX WILL MEANDER ABOUT THE EASTERN CANADIAN
PROVINCES/MARITIMES THROUGH THE MIDDLE OF THE WEEK...BEFORE A CUTOFF
LOW APPROACHING FROM CENTRAL CANADA REINFORCES IT THU AND FRI.
MEANWHILE...A SPLIT FLOW DEVELOPS ACROSS NOAM EARLY IN THE WEEK WITH
A CUTOFF LOW DEVELOPING OVER THE SW AND AN AMPLIFIED RIDGE
DOWNSTREAM.
MOST OF THE DYNAMICS ASSOCIATED WITH THE CUTOFF LOW MOVING ACROSS SE
CANADA AND NEW ENGLAND TUE NIGHT/WED WILL REMAIN TO OUR N.
HOWEVER...ECMWF AND 21Z SREF MEAN BOTH CONTINUES TO PRODUCE SOME
LIGHT QPF ASSOCIATED WITH THE COLD FROPA LATE TUE NIGHT/EARLY WED
MORNING AND THERE COULD BE ENOUGH MOISTURE/LIFT FOR A FEW
SHOWERS...SO HAVE CONTINUED WITH SLIGHT CHANCE POP.
DEEP NW FLOW WILL THEN PREVAILS THROUGH FRI AS THE VORTEX OVER THE
CANADIAN MARITIMES SLOWLY DEPARTS AND RIDGING BUILDS IN FROM CANADA.
IT NOW APPEARS THAT THE NORTHERN BRANCH OF THE POLAR JET WILL BE
DOMINANT INTO LATE WEEK...SO HAVE HIGHER CONFIDENCE THAT HIGH
PRESSURE WITH DRY WEATHER SHOULD CONTINUE THROUGH THE WEEKEND...WITH
A GRADUAL WARMING TREND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE DEEPENING EAST OF THE DELMARVA COAST WILL CONTINUE TO
TRACK OUT TO SEA TODAY.
MAINLY VFR TODAY. THERE ARE SOME MVFR CIGS NORTH OF THE REGION
DROPPING SOUTH...WHICH COULD PRODUCE A BRIEF PERIOD OF MVFR CIGS.
ONCE THESE MVFR CIGS DROP SOUTH OF THE REGION...WE SHOULD REMAIN
VFR THROUGH THE DAY.
WINDS WILL CONTINUE TO RAMP UP THIS MORNING AS THE LOW INTENSIFIES.
NORTHWEST WINDS TODAY 20-30KT WITH SOME GUSTS TO AROUND 35KT. WINDS
DIMINISH SLIGHTLY AFT 23-00Z...THEN GUSTS END ROUGHLY IN THE 5-6Z
PERIOD.
IN THE EXTENDED TAFS...GUSTS KICK IN AGAIN AFT 12Z TUE.
ALL WIND DIRECTIONS N OF 310 TRUE TODAY.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
KLGA FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
KTEB FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
KHPN FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
KISP FCSTER COMMENTS: BRIEF PERIOD OF MVFR CIGS THIS MORNING. WINDS
INCREASE THIS MORNING WITH STRONGEST WINDS AFTER 16Z.
OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
.TUESDAY...VFR. NW GUSTS TO 25 KT POSSIBLE.
.WEDNESDAY...CHANCE OF CIGS BELOW 3FT EARLY...THEN VFR.
.THURSDAY...VFR.
.FRIDAY...VFR.
&&
.MARINE...
A TIGHT PRESSURE GRADIENT IN THE WAKE OF RAPIDLY DEEPENING LOW
PRESSURE WILL INCREASE GUSTS TO AROUND GALE FORCE THIS MORNING. A
GALE WARNING REMAINS IN EFFECT FOR ALL THE FORECAST WATERS THROUGH
THIS AFTERNOON. WINDS ALOFT APPEAR TO SUPPORT JUST MARGINAL
GALES...BUT DEEP MIXING SHOULD KEEP THE NEARSHORE THREAT THROUGH
THIS AFTERNOON. GUSTS EXPECTED TO FALL BELOW GALE LATE THIS
AFTERNOON...BUT SCA GUSTS STILL EXPECTED OVER ALL WATERS INTO LATE
TONIGHT WITH STILL TIGHT GRADIENT AND A SECONDARY SHOT OF CAA.
WINDS EXPECTED TO DIMINISH TO MARGINAL NEARSHORE SCA GUSTS TUESDAY
MORNING...CONTINUING THROUGH THE AFTERNOON. OCEAN SEAS FALLING
BELOW SCA TUESDAY MORNING.
QUIET TUE NIGHT INTO WED MORNING AS A COLD FRONT APPROACHES AND THEN
MOVES THROUGH. SCA CONDITIONS ARE LIKELY ON ALL WATERS AFTER FROPA
WED AFTERNOON AND ON THE OCEAN WED NIGHT...WITH A CHANCE THAT NEAR
SHORE GUSTS COULD REACH MINIMAL GALE FORCE WED AFTERNOON IN THE
HARBOR AND THE OCEAN/SOUND WATERS SURROUNDING NYC AND WESTERN LONG
ISLAND. QUIET THEREAFTER AS HIGH PRESSURE BUILDS FROM THE N.
&&
.FIRE WEATHER...
GENERALLY 1/4 TO 1/2 INCH OF RAIN AREA-WIDE OVER THIS WEEKEND
WILL ALLOW FOR INITIALLY MOIST FINE FUELS. AN ENHANCED THREAT OF
BRUSH FIRE GROWTH/SPREAD IS POSSIBLE THIS AFTERNOON WITH
SEASONABLY MILD TEMPS...HUMIDITY LEVELS LOWERING INTO THE 20
PERCENT RANGE ALONG WITH STRONG NORTHERLY WINDS HELPING TO DRY THE
FUELS. WILL HOLD OFF ON AN SPS...ALLOWING DAYSHIFT TO COORDINATE
ON FUEL CONDITIONS WITH OUR FIRE OFFICIALS.
ONCE FINE FUELS DRY OUT...ENHANCED THREAT OF BRUSH FIRE
GROWTH/SPREAD IS EXPECTED TUESDAY LATE MORNING/AFTERNOON WITH
MILD TEMPS...RH VALUES FALLING INTO THE LOWER 20S AND WINDS GUSTS
AROUND 25 MPH.
A COLD FRONTAL PASSAGE WILL PRODUCE SOME LIGHT PRECIP LATE TUE
NIGHT INTO EARLY WED MORNING...BUT THEN WX CONDITIONS SHOULD
BECOME CONDUCIVE TO FIRE GROWTH/SPREAD WED AFTERNOON...WITH NW
WINDS GUSTING TO 30-35 MPH AND RH LOWERING TO 25-30 PERCENT.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE REMAINDER OF
THE WEEK.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FREEZE WATCH FROM LATE TONIGHT THROUGH TUESDAY MORNING FOR
CTZ010>012.
NY...NONE.
NJ...NONE.
MARINE...GALE WARNING UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ330-335-338-
340-345-350-353-355.
&&
$$
SYNOPSIS...GOODMAN/NV
NEAR TERM...JST
SHORT TERM...NV
LONG TERM...GOODMAN
AVIATION...BC
MARINE...GOODMAN/NV
FIRE WEATHER...
HYDROLOGY...GOODMAN/NV
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1146 AM EDT MON APR 2 2012
.UPDATE...
HAVE UPDATED THE FORECAST THROUGHOUT THE MORNING TO INCREASE CLOUD
COVERAGE ACROSS THE SOUTHWEST PART OF THE CWA. HAVE ALSO SEEN
DEVELOPMENT ACROSS NORTH GEORGIA. OTHERWISE...ONLY MINOR TWEAKS TO
THE FORECAST.
BOTH HRRR AND LOCAL WRF SUGGEST CONVECTION ALONG THE EASTERN EDGE
OF THE CWA SO CONTINUED CURRENT POP FORECAST WHICH REFLECTS THIS.
ALSO AGREE WITH OVERALL THINKING THAT SOME OF THE STORMS COULD
BECOME STRONG. SPC HAS THE AREA IN A SEE TEXT WITH 5 PERCENT FOR
WIND AND HAIL.
11
&&
.PREV DISCUSSION...
SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
/ISSUED 435 AM EDT MON APR 2 2012/
RIDGE ALOFT CONTINUES OVER GEORGIA TODAY WITH PERSISTENT ABOVE
AVERAGE TEMPERATURES AND DRY CONDITIONS. A FRONT MOVING SOUTHWARD
THROUGH THE MID ATLANTIC STATES TODAY SHOULD MOVE INTO THE
SAVANNAH RIVER VALLEY BY TONIGHT. SOME UNCERTAINTY BETWEEN THE
MODELS ON HOW FAR WESTWARD THE FRONT WILL PUSH INTO THE CWA.
HOWEVER...EASTERLY WINDS ARE SHOWN FOR AHN OVERNIGHT AND INTO THE
EARLY MORNING OF TUESDAY. SO HAVE INCLUDED A SLIGHT CHANCE OF
THUNDERSTORMS FOR THE EXTREME NORTHEAST CORNER THIS
AFTERNOON...AND A SLIGHT CHANCE TONIGHT ALONG MUCH OF THE EASTERN
SIDE OF THE CWA. MEANWHILE...A SHORT WAVE FROM THE NORTHWEST GULF
MOVES INTO THE LOWER MISSISSIPPI VALLEY TONIGHT AND INTO THE OHIO
VALLEY ON TUESDAY. THIS WILL BRING A CHANCE OF THUNDERSTORMS INTO
THE REMAINDER OF THE CWA TUESDAY AND TUESDAY NIGHT. HAVE TAKEN A
COMPROMISE ON THE MAV/MET TEMPERATURES. WITH THE POSSIBILITY OF A
BACKDOOR FRONT AFFECTING THE EASTERN COUNTIES...HAVE TRENDED
TOWARD THE COOLER TEMPERATURES TUESDAY AND TUESDAY NIGHT IN THAT
AREA.
41
LONG TERM /WEDNESDAY THROUGH SUNDAY/...
/ISSUED 435 AM EDT MON APR 2 2012/
EXTENDED PROGS APPEAR TO BE COMING INTO SOMEWHAT BETTER AGREEMENT
WITH THE UPPER RIDGE BEGINNING TO FLATTEN OUT OVER THE SOUTHEAST
U.S. WEDNESDAY/THURSDAY AS AN UPPER TROUGH/CLOSED LOW COMPLEX MOVES
EAST FROM THE PLAINS. ECMWF CONTINUE TO BE A TAD SLOWER (AND
FARTHER SOUTH) WITH THIS SYSTEM MOVING EASTWARD. BY 12Z FRIDAY GFS
TAKES THE LOW ACROSS TENNESSEE AND INTO THE CAROLINAS BY THE END
OF THE DAY...WHILE THE ECMWF SHOWS THE LOW OVER ALABAMA MOVING
INTO EAST CENTRAL GEORGIA DURING THIS TIME PERIOD. BOTH SHOW THIS
SYSTEM EAST OF OUR AREA BY SATURDAY WITH A HIGH PRESSURE RIDGE
BEGINNING TO BUILD BACK ACROSS THE SOUTHEAST STATES. NONETHELESS
WILL CONTINUE PREVIOUS FORECAST TREND WITH CHANCE TO GOOD CHANCE
POPS MUCH OF THE AREA WEDNESDAY INTO FRIDAY...WITH SLIGHT CHANCE
POPS FRIDAY NIGHT...ENDING ALL PRECIP BY SATURDAY.
49
CLIMATE...
RECORDS FOR 04-02
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 89 1940 46 1915 63 1908 28 1924
KATL 88 1940 42 1915 63 1979 25 1881
1905
KCSG 86 1999 54 1993 67 2000 34 1992
1978 1961
KMCN 88 1940 48 1915 63 2000 32 1992
1935
RECORDS FOR 04-03
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 88 1934 47 1987 62 2007 26 1992
1974
KATL 86 1946 39 1987 65 1974 29 1992
1945
KCSG 88 1999 52 1987 70 1977 32 1962
1957
KMCN 89 1957 51 1901 69 1977 31 1993
1992
1971
AVIATION...
12Z UPDATE...
/ISSUED 740 AM EDT MON APR 2 2012/
AREA OF IFR STRATUS CONTINUES TO EXPAND NORTH AND EAST INTO AL AND
GA. LOOKS LIKE CLOUDS MAY HOLD TOGETHER TO REACH ATL AROUND 13Z AND
THEN GRADUALLY LIFT INTO MVFR WITH HEATING. EXPECTING VFR BY AROUND
17Z. CEILINGS MAY NOT MAKE IT INTO MCN AND AHN AS IFR BUT MAY LIFT
INTO MVFR. SOUTHWEST WINDS INCREASING TO 10 TO 15KT BY 15Z WITH SOME
GUSTS TO NEAR 20KT AFTER 17Z.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON STRATUS. HIGH CONFIDENCE ON AL OTHER ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 86 59 81 58 / 10 20 30 30
ATLANTA 84 65 84 63 / 5 10 20 30
BLAIRSVILLE 82 57 80 54 / 20 20 30 40
CARTERSVILLE 84 61 85 59 / 10 10 20 40
COLUMBUS 86 65 86 62 / 0 10 20 20
GAINESVILLE 85 61 81 60 / 10 20 30 40
MACON 87 62 86 61 / 0 10 20 20
ROME 85 58 86 60 / 10 10 20 40
PEACHTREE CITY 84 61 85 58 / 0 10 20 20
VIDALIA 85 64 84 65 / 10 10 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1129 AM EDT MON APR 2 2012
.UPDATE...
QUIET WEATHER FOR THIS AFTERNOON WITH MAIN FOCUS CONTINUING ON
TEMPERATURE TRENDS. TEMPERATURES HAVE BEEN VERY SLOW TO RISE THIS
MORNING DUE IN LARGE PART TO A VERY STRONG MORNING INVERSION NOTED
PER AMDAR SOUNDINGS WHICH WERE ONLY MIXED TO BETWEEN 1500-2000 FT
LATE THIS MORNING. SOME SUBTLE DIFFERENCES NOTED IN MIXED LAYER
DEPTHS BETWEEN NAM/RUC FOR THIS AFTERNOON WITH NAM SUGGESTING A
SLIGHTLY DEEPER MIXED LAYER THAT WOULD ALLOW FOR AFTERNOON HIGHS
CLOSE TO THOSE CURRENTLY FORECASTED. THESE HIGHS MAY REPRESENT A
BEST CASE SCENARIO IN TERMS OF MAX HEATING POTENTIAL
TODAY...ESPECIALLY IF MIXING HEIGHTS ARE A BIT MORE SHALLOW LIKE
THE RUC WOULD SUGGEST. WILL HOLD OFF ON ANY ADJUSTMENTS TO MAX
TEMPS AT THIS TIME AND JUST REFINE DIURNAL CURVE TO PUT MOST OF
TEMPERATURE INCREASE IN THE 17Z TO 20Z PERIOD DUE TO EFFECTS FROM
THE INVERSION. MORE SOLID STRATOCU DECK ACROSS NORTHWEST OHIO
SHOULD CONTINUE TO ERODE THROUGH THE AFTERNOON AND NOT PLAY A
MAJOR ROLE IN LIMITING AFTERNOON TEMP RISES. UPDATED FORECAST SENT
EARLIER THIS MORNING MAINLY TO REFINE SKY COVER TRENDS.
&&
.PREV DISCUSSION... /ISSUED 702 AM EDT MON APR 2 2012/
AVIATION.../12Z TAFS/
PATCHY STRATO CU WITH MVFR CIGS OVER NRN INDIANA EARLY THIS
MORNING... AND A LITTLE MORE WIDESPREAD UPSTREAM OVER NRN OH.
EXPECT WITH DIURNAL HEATING/MIXING THESE CLOUDS WILL DIMINISH
AFTER SUNRISE WITH JUST PATCHY ALTO CU OR CIRRUS THIS AFTN/EVE.
WK LOW WILL MOVE TOWARD THE AREA TONIGHT WITH LLJ TRANSPORTING
INCRSG MOISTURE AND RESULTANT ELEVATED INSTABILITY INTO THE AREA
LATE TONIGHT PSBLY LEADING TO SCT TS...THUS ADDED CB WITH LOW VFR
CIGS AT BOTH TERMINALS TOWARD THE END OF THE PERIOD. GRADIENT
BETWEEN SFC RIDGE MOVG TO LWR GRTLKS AND SF LOW/WARM FRONT MOVG
INTO THE MS VALLEY WILL RESULT IN FAIRLY STRONG ESE SFC WINDS AT
THE TERMINALS TODAY WITH GUSTS AROUND 22KT.
PREV DISCUSSION... /ISSUED 457 AM EDT MON APR 2 2012/
SHORT TERM.../TODAY-TUE NGT/
SHRTWV DROPPING SSE INTO MID ATLANTIC THIS MORNING HAS PUSHED A
BACKDOOR CDFNT THROUGH OUR AREA TO THE LOWER OH VALLEY. MID LEVEL
CONVERGENT FLOW WAS RESULTING IN A COUPLE OF BANDS OF SCT HIGH BASED
SHOWERS BEHIND THE FRONT... ONE OVER SWRN MI AND ANOTHER OVER ERN
INDIANA/SWRN OH. RIDGE ALOFT BUILDING EASTWARD THIS MORNING SHOULD
DIMINISH THIS ACTIVITY OVER THE NEXT 3-6HRS SO LEFT OUT OF TODAYS
FCST WITH SHOWERS FCST TO END BY 12Z IN OUR AREA. RIDGE EXTENDING
SOUTH FROM HUDSON BAY TO THE GRTLKS BEHIND THIS CDFNT SHOULD
PROVIDE FAIR WX TODAY. CDFNT TRANSITIONS TO A STNRY FRONT FROM SRN
IL TO LOW PRESSURE CENTERED OVER NEB/KS. THIS LOW ASSOCIATED WITH
CLOSING OFF UPR SYSTEM OVER AZ/NM AND SHOULD GRADUALLY WEAKEN
TODAY. NRN STREAM SHRTWV MOVG EAST ACROSS MT/SASK WILL RESULT IN
EASTWARD MOVEMENT OF THE WKNG SFC LOW THROUGH THE SHORT TERM
PERIOD. THIS WILL RESULT IN A RATHER TIGHT SFC PRESSURE GRADIENT
ACROSS OUR CWA WITH E-SE SFC WINDS OF 10-20MPH. THIS SHOULD
PROVIDE DECENT MIXING AND SUSPECT MODELS ARE A LITTLE TOO SHALLOW
WITH THE BOUNDARY LAYER THIS AFTN...THUS STAYED CLOSE TO PREVIOUS
FCST HIGHS FOR TODAY WHICH WERE GENERALLY AT OR A BIT ABOVE
LATEST MOS.
AS LOW MOVES CONTS SLOWLY EAST ACROSS IA TONIGHT STNRY FRONT WILL
LIFT SLOWLY NE INTO IL AS A WARM FRONT. H85 THETA-E ADVECTION NE
OF THE SFC WARM FRONT SPREADING INTO OUR AREA ALONG WITH ELEVATED
INSTABILITY IS EXPECTED TO RESULT IN SCT TSTMS DVLPG OVERNIGHT.
GIVEN EXPECTATION OF INCRSG CLOUDS AND SOME GRADIENT WINDS TONIGHT
LEANED TOWARD WARMER END OF GUIDANCE FOR LOWS WHICH ARE FCST TO
RANGE FROM THE U30S NE TO THE L50S SW.
WK LOW IS FCST SIMILARLY BY 00Z MODELS TO TRACK EASTWARD ACROSS OUR
CWA ON TUESDAY. THIS IS SLOWER THAN INDICATED BY EARLIER
NAM/GFS/SREF RUNS... ALLOWING WARMER/MORE MOIST AIRMASS TO SPREAD
INTO THE AREA DURING THE DAY TUE. DESTABILIZATION IS LIKELY WITH
CAPE EXPECTED TO INCREASE INTO THE 1500-2500J/KG RANGE. MOIST
CONVERGENCE ALONG THE WARM/CDFNT ASSOCIATED WITH THE LOW MOVG
THROUGH OUR AREA MAY PROVIDE SUFFICIENT FORCING FOR SCT TSTM
DEVELOPMENT. HWVR... WARM MID LEVEL TEMPS WILL RESULT IN A
CAPPING INVERSION WHICH MAY NOT BREAK UNTIL LATE AFTN OR EVE.
0-6KM SHEAR FCST TO BE WK DURING THIS PERIOD, BUT GIVEN POTENTIAL
DVLPG INSTABILITY, ISOLATED SVR STORMS ARE PSBL. WITH THE SLOWING
TREND OF MODELS TO MOVE LOW/CDFNT THROUGH THE AREA... 00Z RUNS
SUGGESTING HIGH TEMPS COULD BE 5-10F WARMER THAN OUR PREVIOUS
FCST... FOR NOW UTILIZED A BLEND OF 00Z MODEL CONSENSUS AND
PREVIOUS FCST TO TREND HIGHS UP ABOUT 3F. THE MODELS SLOWER TREND
ON MOVING LOW THROUGH THE AREA MAY ALSO IMPACT LOWS TUE NIGHT WITH
COLDER AIR PRBLY SLOWER TO ARRIVE IN OUR AREA. AGAIN JUST TRENDED
UP A FEW DEGREES ATTM.
LONG TERM...
WEDNESDAY THROUGH SUNDAY...THE MAIN CHALLENGES THIS PERIOD INCLUDE
THE CHANCES FOR FROST WEDNESDAY NIGHT THROUGH FRIDAY NIGHT AND THE
POSSIBILITY OF THUNDER OVER THE WEEKEND. FOR THIS PACKAGE...FAVORED
THE ECMWF AND CANADIAN GEM ENSEMBLES. AN UPPER LOW EMBEDDED IN A
RIDGE WILL DRIFT EAST AND WILL PASS SOUTH OF THE FORECAST AREA. KEPT
CONDITIONS DRY THROUGH SATURDAY. HAVE TRENDED TEMPERATURES DOWN MOST
PERIODS THROUGH FRIDAY NIGHT AS A CHILLY NORTH EAST TO EAST FETCH
PERSISTS OVER EASTERN CANADA INTO THE WESTERN GREAT LAKES REGION.
HAVE ADJUSTED THE TIMING OF FROST IN THE GRIDS AND HAZARDOUS WEATHER
OUTLOOK TO MATCH THIS SCENARIO...WITH THE BEST CHANCE FOR FROST
THURSDAY NIGHT. GUT FEELING IS HIGHS FRIDAY ARE STILL TOO WARM...AND
MAY NEED TO BE LOWERED 3 TO 6 MORE DEGREES. THE GFS MEX MOS HIGH OF
63F AT FT WAYNE DEFINITELY LOOKS TOO WARM. CORRESPONDINGLY...GFS MEX
DIURNAL SPREADS OF 30 AND 33 RESPECTIVELY FOR FRIDAY AND SATURDAY
ALSO LOOK TOO LARGE. THE CANADIAN GEM ENSEMBLES EPS GRAMS LOOK GOOD
WITH A TIGHT CLUSTER OF MEMBERS WITH LOWS JUST ABOVE FREEZING
THURSDAY NIGHT AND HIGHS FRIDAY AOB 53 AT FT WAYNE. OTHERWISE...KEPT
A CHANCE FOR THUNDER SATURDAY NIGHT INTO SUNDAY. MOISTURE IS LIMITED
AND FORCING APPEARS MARGINAL AS THE SURFACE LOW TRACKS FROM THE
UPPER MIDWEST INTO SOUTHERN CANADA DURING THIS PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...JT
UPDATE...MARSILI
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1120 AM EDT MON APR 2 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY AND DROP
TEMPERATURES NEAR FREEZING TONIGHT ACROSS PORTIONS OF THE AREA. A
FRONTAL BOUNDARY WILL APPROACH FROM THE SOUTHWEST TOMORROW, BRINGING
WARMER TEMPERATURES WITH THE CHANCE OF SHOWERS AND THUNDERSTORMS
LATE IN THE DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT
FOR THE LATEST TRENDS IN TEMPS AND SKY.
THE LATEST RUC 300MB ANALYSIS INDICATES RIDGING AND WEAK
WINDS ALOFT BEGINNING TO BUILD INTO THE OHIO VALLEY FROM THE WEST AS A
140KT JET SLIDES EAST OF THE AREA INTO THE NORTHEAST. A SWATH OF
DRY AIR ABOVE 850MB IS EVIDENT SLIDING SOUTHEASTWARD ACROSS
WESTERN PA. AT THE SURFACE, A 1025MB HIGH IS CENTERED OVER THE
HUDSON BAY WITH HIGH PRESSURE EXTENDING SOUTHEASTWARD INTO THE
GREAT LAKES. A NORTHEASTERLY LOW-LEVEL FLOW IS PUSHING
STRATOCUMULUS, WHICH IS DIMINISHING, SOUTHWEST OF THE PITTSBURGH
METRO.
TODAY AND TONIGHT...THERE IS OPERATIONAL MODEL AGREEMENT THAT THE
RIDGE WILL EDGE EASTWARD AND BECOME CENTERED OVER THE GREAT LAKES. A
NORTHWESTERLY FLOW ALOFT WILL ALLOW FOR HIGH PRESSURE TO SLIDE
FURTHER SOUTHWARD INTO THE UPPER OHIO VALLEY, BECOMING CENTERED
NORTHEAST OF PITTSBURGH BY 12Z TUESDAY. THUS, CLOUD COVERAGE WILL
CONTINUE TO DIMINISH EARLY TODAY WITH CLEARING ACROSS THE AREA.
TEMPS ARE IN LINE WITH THE PREVIOUS FORECAST, SO FORECAST HIGHS
CONTINUE TO BE A FEW DEGREES WARMER THAN A MAV/MET BLEND AND
SEASONAL NORMS. THE BEST RADIATIONAL COOLING TONIGHT WILL OCCUR
CLOSEST TO THE SURFACE HIGH, WHICH WILL BE NORTHEAST OF PITTSBURGH.
CURRENTLY, THE MOST CONFIDENCE IN A FREEZE IS ALONG THE I-80 CORRIDOR.
PATCHY FROST IS FORECAST FOR AREAS NORTHEAST OF PITTSBURGH AND
ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HAVE MAINTAINED A FORECAST OF CHANCE SHOWERS AND THUNDERSTORMS IN
THE WARM ADVECTION REGIME OF THE AFOREMENTIONED LOW PRESSURE SYSTEM
ON TUESDAY AFTERNOON AND WITH THE COLD FRONT ON TUESDAY NIGHT.
HIGH PRESSURE WILL FOLLOW WITH DRY AND COOLER CONDITIONS WEDNESDAY.
THE SHORT TERM TEMPERATURE FORECAST WAS COMPLETED USING A BLEND
OF GUIDANCE AND FEATURES READINGS FROM 5 TO 10 DEGREES ABOVE
NORMAL TUESDAY...AND NEAR NORMAL FOR WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
DRY WEATHER SHOULD PREVAIL ACROSS THE UPPER OHIO VALLEY REGION INTO
THE WEEKEND AS A LARGE AREA OF HIGH PRESSURE SLIDES SOUTHEAST ACROSS
THE GREAT LAKES.
A SLOW MOVING LOW PRESSURE SYSTEM WILL TRACK EASTWARD FROM THE LOWER
MS VALLEY TO OFF SOUTHEAST COAST LATE IN THE WEEK. THE BULK OF
ASSOCIATED MOISTURE IS PROGGED TO REMAIN SOUTH OF THE FORECAST AREA.
HPC GUIDANCE SHOWS THE NEXT COLD FRONT APPROACHING FROM THE WEST
WITH A CHANCE OF SHOWERS LATE SUNDAY.
TEMPERATURES ARE FORECAST TO BE NEAR NORMAL THROUGH FRIDAY...THEN
WARMING TO AROUND 10 DEGREES ABOVE NORMAL DURING THE WEEKEND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT POSTFRONTAL COLD
POOL STRATOCUMULUS CLOUD BANK TO CONTINUE TO ERODE THIS MORNING,
NORTHEAST TO SOUTHWEST. SO REMAINING MVFR CEILINGS SHOULD BE AT
VFR LEVELS BY 16Z AND DISSIPATED BY 17Z. EXPECT VFR CLEAR SKIES
TONIGHT.
SURFACE WINDS WILL BE FROM THE NORTH AND NORTHEAST NEAR 10 KTS
TODAY, THEN GO LIGHT TONIGHT.
OUTLOOK...TUESDAY THROUGH FRIDAY...
RESTRICTIONS POSSIBLE TUESDAY LATE AFTERNOON AND NIGHT WITH
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS. OTHERWISE VFR.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
633 AM EDT MON APR 2 2012
.SYNOPSIS...
ISSUED AT 515 AM EDT MON APR 2 2012
UPPER RIDGE BUILDS INTO THE AREA TODAY BUT MOISTURE ADVECTION AT
H85/H7 IS ALREADY SPAWNING SHRA/TSRA FM NORTHERN MN INTO NW WI AND
TOWARD FAR WESTERN UPR MI. WILL HAVE TO CONTEND WITH AT LEAST ISOLD
SHRA/TSRA TODAY MAINLY OVR WEST THIRD OF CWA. BETTER CHANCE FOR RAIN
ARRIVES LATER TONIGHT AS SFC LOW AND INVERTED TROUGH SLIDE ACROSS
UPR MI. SOME RAIN LINGERS ON TUESDAY MORNING BUT AFTER THAT DRY
WEATHER DOMINATES THE REST OF THE WEEK AS HIGH PRESSURE EXPANDS FM
HUDSON BAY ACROSS THE GREAT LAKES REGION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
TODAY...UPPER RIDGE CONTINUES TO BUILD FM THE PLAINS INTO THE
WESTERN GREAT LAKES THROUGH THE DAY WHILE AT THE SFC...HIGH OVR
HUDSON BAY WILL EXPAND A RIDGE AXIS ACROSS MUCH OF MICHIGAN. AT
FIRST GLANCE...DOES NOT APPEAR TO BE A FAVORABLE SETUP FOR MUCH
PRECIPITATION TODAY OVR UPR MI...BUT CERTAINLY CANNOT IGNORE
CLUSTER OF SHRA/TSRA THAT HAVE FORMED OVR NORTHERN MN INTO
NORTHWEST WI THE LAST FEW HOURS. SHRA/TSRA SEEM TO BE RUNNING ALONG
AND NORTH OF RIBBON OF HIGHER H7 DWPNTS AND ON NORTHERN EDGE OF
STEEPER H7-H5 LAPSE RATES FM MN INTO WI. ONLY 00Z GUIDANCE THAT
SHOWED TSRA AS FAR EAST AS IS CURRENTLY OCCURRING WAS HRRR. ALL
OTHER GUIDANCE KEPT GENESIS REGION FOR SHRA/TSRA OVR WESTERN MN
WHERE BETTER H85 THETA-E ADVECTION IS TAKING PLACE.
FOLLOWING RUC13/NAM H7 DWPNTS/WINDS SUGGESTS THAT AT LEAST ISOLD
TSRA WILL EASE INTO WESTERN THIRD OF CWA THIS MORNING BEFORE FADING
AWAY AS RIBBON OF HIGHER H7 DWPNT WEAKENS. WILL KEEP POPS IN OVR
WEST ALL DAY THOUGH AS RUC INDICATES HINT OF H7 MOISTURE AXIS COULD
PERSIST INTO EARLY AFTN. DESPITE RESERVOIR OF H7-H5 LAPSE RATES AOA
8C/KM UPSTREAM...MINIMAL LARGE SCALE FORCING AND MARGINAL 3-6KM
SHEAR /20KT OR SO/ SHOULD LEAD TO ONLY SLIM CHANCES OF SEEING
HAIL WITH THESE STORMS. WILL NEED TO MONITOR TRENDS THIS MORNING
THOUGH. BY LATE AFTN...EXPECT MAIN AREA OF SHRA/TSRA WEST OF UPR
MI IN AREA OF GREATEST H85 TEMP/MOISTURE ADVECTION.
OTHER ISSUE TODAY ESPECIALLY THIS MORNING IS FOG. FOR THE MOST PART
THE FOG IS OVR HIGHER TERRAIN OF NCNTRL CWA AND HIGHER TERRAIN OF
KEWEENAW. EVEN IN THESE AREAS MAIN IMPACT IS MORE OF STRATUS DECK
WITH VARIABLE VSBY. EXPECT DRY ADVECTION OVR EASTERN UPR MI TO
SPREAD EAST AND DIMINISH THE FOG BY MID MORNING /AS ALREADY HAS
OCCURRED AT ERY EARLY THIS MORNING/. COVERAGE OF CLOUDS /LOWER AND
MID/ BY MID AFTN COULD BE CHAOTIC WHICH WILL NO-DOUBT IMPACT HIGH
TEMPS. SE GRADIENT WIND OFF THE LAKES SHOULD KEEP TEMPS IN CHECK
EVEN IF DECENT AMOUNT OF SUNSHINE ENDS UP OCCURRING. EXPECT HIGHS TO
MAINLY TOP OUT IN THE 50S...COOLER NCNTRL WITH UPSLOPE FLOW. GIVEN
ENOUGH SUNSHINE SOME SPOTS MAY PUSH PAST 60 DEGREES...BUT NOT TOO
MUCH HIGHER.
TONIGHT...UPR RIDGE REMAINS IN TACT TO START THE EVENING THEN
OVERNIGHT NORTHERN STREAM SHORTWAVE MOVES FM MANITOBA INTO
NORTHWEST ONTARIO. AS THIS TROUGH APPROACHES...SFC LOW OVR THE
PLAINS WILL LIFT INTO WESTERN GREAT LAKES WITH INVERTED SFC TROUGH
AND H85 TROUGH SLIDING WEST TO EAST ACROSS UPR MI. MODELS HAVE
TRENDED A BIT SLOWER WITH ARRIVAL OF UPR AND SFC TROUGH. PREVIOUS
FCST HAD GOOD HANDLE ON TREND WITH HIGHER POPS OVERNIGHT. WHAT TO DO
WITH POP COVERAGE IS MAIN ISSUE. BASED ON EXPECTED LARGE SCALE
PATTERN AND FCST LOCATION OF HIGHER MUCAPE...WOULD FIGURE THAT
HIGHEST POPS WOULD BE OVER LK SUPERIOR AND MAINLY TO SOUTH OF CWA.
THOUGH CONVERGENCE FM INVERTED SFC TROUGH INTERSECTING S/SW FLOW AT
H85 /DPWNTS AOA +10C/ SUPPORTS HIGHER POPS OVR CWA AS WELL. KEPT
POPS HIGH CHANCE TO LIKELY AS THE INVERTED TROUGH SLIDES THROUGH CWA.
TSRA CHANCES SEEM MINIMAL BASED ON MAIN MUCAPE STAYING OVR WI AND
850-300MB THICKNESSES ORIENTED WNW TO ESE. HOWEVER...IF CONVECTION
MAINLY FIRES ON FAR NORTH EDGE OF HIGHER INSTABILITY /AS OCCURRED
THIS MORNING/ THEN IT IS FEASIBLE THERE COULD BE COMPLEX OF TSRA
AFFECTING PORTIONS OF CWA OVERNIGHT TONGIHT INTO EARLY TUESDAY
MORNING. LIKELY WILL NOT KNOW IF THIS IS THE CASE UNTIL MAYBE LATE
THIS EVENING OR OVERNIGHT TONIGHT.
TUESDAY...SLOWER TREND OF TROUGH PASSAGE CONTINUES TO SHOW UP INTO
TUESDAY AND HAVE DELAYED DIMINISHING POPS UNTIL EARLY TUESDAY AFTN.
AT THIS POINT /COULD BE FURTHER SLOWER TREND/ HIGHEST POPS ON
TUESDAY WILL BE THROUGH ROUGHLY 16Z /NOON EDT/ OVR EASTERN HALF OF
CWA MAINLY TO EAST OF MARQUETTE AND IRON MOUNTAIN. KEPT SMALL
CHANCES FOR TSRA IN PICTURE ALONG LK MICHIGAN IN THE MORNING UNTIL
H85 WINDS VEER WEST PUSHING THE HIGHER H85 DWPNTS/INSTABILITY TO
SOUTHEAST OF CWA. WINDS TURNING NORTH BEHIND THE TROUGH SHOULD KEEP
CLOUDS IN OVR MUCH CWA THROUGH MUCH OF AFTN. DECREASING CLOUDS
EXPECTED LATE AFTN THOUGH PER MODEL CONSENSUS OF RAPIDLY LOWERING
DWPNTS AT H85 AND PER FCST SOUNDINGS. POSSIBLE THAT SOME LOW CLOUDS
AND/OR FOG MAY TRY TO ADVECT ONSHORE SIMILAR TO WHAT OCCURRED SUNDAY
AFTN. LATER SHIFTS CAN ADDRESS THIS IN MORE DETAIL AND ADD IF IT
SEEMS REASONABLE. LOWERED TEMPS ESPECIALLY IN THE NORTH CWA DUE TO
LATER DEPARTURE OF PCPN AND CLOUDS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
HIGH PRESSURE SLIDING IN TUESDAY EVENING FROM MANITOBA AND EASTERN
ND/WESTERN MN WILL BRING ABOUT A PROLONGED PERIOD OF DRY WEATHER.
EXPECT THE HIGH TO PUSH OVER THE UPPER GREAT LAKES WEDNESDAY
AFTERNOON...BEFORE STRENGTHENING ACROSS THE AREA THROUGH FRIDAY.
GIVEN A SLIGHTLY SLOWER SOLUTION AND A LINGERING 500MB TROUGH
OVERHEAD THROUGH WEDNESDAY EVENING...WILL KEEP WITH LINGERING CLOUDS
EAST INITIALLY TUESDAY NIGHT...AND AFTERNOON CLOUDS DEVELOPING NEAR
900MB POSSIBLE CENTRAL AND EAST. EXPECT ONLY LIMITED CLOUDS AT THIS
TIME GIVEN OUR DRY ATMOSPHERE WITH PW VALUES ABOUT 60 PERCENT OF
NORMAL AROUND 0.26IN.
LOWERED DEW POINTS A COUPLE OF DEGREES FOR WEDNESDAY
AFTERNOON...MAINLY INTERIOR WEST...WITH RH VALUES ACROSS THIS AREA
BOTTOMING OUT AROUND 25 TO 30 PERCENT. WITH NO SIGNIFICANT INFLUX OF
MOISTURE...RH VALUES SHOULD FALL BETWEEN 25 AND 35 PERCENT THROUGH
FRIDAY /ONCE AGAIN MAINLY ACROSS THE INTERIOR WEST HALF/.
LOW PRESSURE DEVELOPING OFF THE NORTHERN ROCKIES MID WEEK SHOULD
PUSH ACROSS THE PLAINS STATES FRIDAY NIGHT...BEFORE SLIDING
DEEPENING TO OUR WEST SATURDAY...AND PUSHING UP AND ACROSS ONTARIO
SATURDAY NIGHT INTO SUNDAY. THE FORECAST MODELS LOOK TO BE IN FAIRLY
GOOD AGREEMENT UNTIL THE FOCUS SHIFTS TO THE NEARING LOW SATURDAY
AFTERNOON. AFTER SATURDAY...I HAVE ONLY MODERATE CONFIDENCE IN THE
ONGOING FORECAST /MAINLY WITH RESPECT TO TIMING AND PRECIPITATION
TYPE AS THE LOW EXITS/.
AFTERNOON TS SATURDAY MAY LINGER INTO SATURDAY NIGHT EAST. WHILE THE
QUICKER 01/12Z RUN OF THE ECMWF WOULD HAVE THEM OUT OF ERY BY 06Z
SUNDAY. WILL TAKE OUT ANY MENTION OF WRAP AROUND SHSN SUNDAY...BUT
IT MAY NEED TO BE ADDED BACK IN IF THE ECMWF VERIFIES WITH 850MB
TEMPS FALLING TO AROUND -3 OR -4C BY EARLY AFTERNOON WEST AND
CENTRAL. INSTEAD OF RUNNING A NON-DIURNAL TEMP TRACE FOR
SUNDAY...KEPT WITH TRADITIONAL RISING TEMPS DURING THE DAY /SIMILAR
TO THE GFS/. AS NOTED...THIS WILL LIKELY BE REVISED MORE THAN A FEW
TIMES BEFORE OVER THE NEXT FEW DAYS AS FCST MODELS MERGE ON A
SOLUTION...SO WILL NOT GET TOO SPECIFIC AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM EDT MON APR 2 2012
LOW CLOUDS AND SOME FOG WILL AFFECT CMX AND SAW THROUGH MID MORNING.
MAIN IMPACT WILL BE CIGS BLO ALTERNATE AIRPORT MINS BUT BRIEF VSBY
OF LIFR/IFR POSSIBLE AS WELL. PROBLEM AT IWD WILL BE SHRA/ISOLD TSRA
THROUGH MID MORNING. COULD SEE BRIEF VSBY REDUCTIONS BUT SHOULD ONLY
BE MVFR BASED ON UPSTREAM OBSERVATIONS AND SINCE SE WIND DIRECTION
IS NOT FAVORABLE FOR ANY ADDITIONAL LIFTING VIA UPSLOPE. EXPECT ALL
TAF SITES TO BE VFR BY EARLY AFTN WITH SCT-BKN MID CLOUDS. MAIN
FRONT AND SFC LOW COME ACROSS UPR MICHIGAN TONIGHT. SCT LINE OF SHRA
AND PERHAPS A TSRA AS WELL WILL SLIDE WEST-TO-EAST LATER IN THE
EVENING THROUGH THE OVERNIGHT HOURS. MODELS VARY ON EXACT DEPICTION
OF RAIN WITH FROPA SO KEPT WITH BROADBRUSHED DEPICTION FOR THE
TIMING OF THE RAIN. POTENTIAL FOR SIGNIFICANT REDUCTION TO CIGS/VSBY
WITH ANY SHOWERS DOES APPEAR REMOTE RIGHT NOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON APR 2 2012
WINDS SHOULD REMAIN BELOW 30KTS THROUGH AT LEAST FRIDAY. AN EXITING
RIDGE OVER LAKE HURON WILL DRIFT ACROSS THE LOWER GREAT LAKES TODAY.
IN ITS PLACE...A TROUGH WILL SLIDE IN FOR LATE TONIGHT INTO TUESDAY
MORNING. EXPECT A HIGH OVER THE NORTHERN PLAINS AND CENTRAL CANADA
TUESDAY TO SLOWLY SLIDE OVER LS WEDNESDAY...WHERE IT SHOULD REMAIN
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLA
SHORT TERM...JLA
LONG TERM...KF
AVIATION...JLA
MARINE...KF
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1027 AM CDT MON APR 2 2012
.UPDATE...
THE 12Z NAM AND 09Z SREF ARE REASONABLE IN THE PLACEMENT OF THE
CURRENT BAND OF ELEVATED THUNDERSTORMS STRETCHING FROM NEAR BIG
FORK TO CRANE LAKE IN THE NORTHWESTERN FA. THEREFORE...MADE
UPDATES TO POPS/WEATHER THROUGH THIS AFTERNOON THAT LEANED ON THE
NAM/SREF WHICH FOCUSES PCPN ACROSS THE NORTHERN AND WESTERN FA.
DOWNPLAYED THE EMPHASIS ON THE CHANCES OF THUNDER TO GIVE GREATER
EMPHASIS ON RAIN SHOWERS SINCE MODEL INDICES AND INSTABILITY DO
NOT APPEAR FAVORABLE FOR CONVECTION. AT THIS TIME...THE SPC
MESOANALYSIS PAGE INDICATES UP TO 5OO J/KG OF ELEVATED CAPE BY
THAT BAND OF THUNDERSTORMS...AND MOST UNSTABLE LIFTED INDICES
AROUND -2 TO -5. THERE HAVE BEEN SOME REPORTS OF MINOR HAIL WITH
THESE STORMS...AND THIS TREND OF PULSING STORMS WITH SMALL HAIL
WILL LIKELY CONTINUE FOR AT LEAST THE NEAR FUTURE. WHILE THE
UPDATES PULLED SOME EMPHASIS OF PCPN FROM THE SOUTHERN FA...WILL
NEED TO KEEP AN EYE ON A BOUNDARY STRETCHING FROM ABOUT HINCKLEY
TO NORTHERN CASS COUNTY THAT IS MOVING TO THE SOUTHWEST. SINCE
THERE IS GREATER INSTABILITY ACROSS THE SOUTHWESTERN FA...WILL
NEED TO SEE IF THIS BOUNDARY BECOMES A TRIGGER FOR STORMS. ONLY
MADE MINOR CHANGES TO THE TEMPERATURES AND WINDS.
&&
.PREV DISCUSSION... /ISSUED 641 AM CDT MON APR 2 2012/
AVIATION...12Z TAFS.
BKN MID DECK DEVELOPING OVER NE MN AND NW WI WILL AFFECT THE TAF
SITES THROUGH THIS FORECAST CYCLE. SHOWERS FROM THE MN ARROWHEAD
INTO NW WI TO MOVE E AND DISSIPATE. SFC TROF IN THE RED RIVER
VALLEY WILL MOVE INTO THE FA ALONG WITH MID LEVEL INSTABILITY AXIS.
SOME SHOWERS MAY FORM BY 15Z NEAR KINL...HOLDING OFF UNTIL LATER
THIS AFTERNOON NEAR KHIB/KBRD. INSTABILITY AXIS ALIGNS ITSELF OVER
THE AREA BETWEEN 18Z-21Z AND ALONG WITH THE SFC TROF WILL BE THE
FOCUS FOR THUNDERSTORMS. USED VCTS AT KBRD/KHYR AS TIMING OF
STORMS IS IN QUESTION AND CONFIDENCE IS LOW. PCPN WILL DIMINISH
FROM NW TO SE THIS EVENING WITH LOSS OF SOLAR/INSTABILITY.
PREV DISCUSSION... /ISSUED 331 AM CDT MON APR 2 2012/
SHORT TERM...RUC ANALYSIS DOING GOOD JOB HIGHLIGHTING GENESIS
REGION OF CONVECTION THIS MORNING OVER WCTRL MN. MID LVL
INSTABILITY AXIS IS ALIGNED EAST ACROSS CWA FROM CASS LAKE TO TWIN
PORTS AND THEN SE TO NRN PRICE COUNTY. CONVECTION HAS TRAINED
ALONG THIS CORRIDOR WITH SMALL HAIL REPORTED AT TIMES. A
SECONDARY 70H THETAE MAX IS DEVELOPING ACROSS SRN KOOCH/NRN ITASCA
VICINITY AND NEW CONVECTION IS FORMING THERE AS WELL. AREA REMAINS
UNDER MID LVL RIDGE AXIS WITH A WEAK SHORTWAVE TROF LIFTING OVER
RIDGE AXIS.
TODAY...USED RUC AS SHORT TERM GUIDANCE FOR PLACING HIGHER POPS
ALONG AFOREMENTIONED INSTABILITY AXIS AS IT MOVES GRADUALLY NORTH
THIS MORNING. BY MIDDAY FOCUS OF CONVECTION MAY BE ALIGNED FROM
NWRN CWA TO NR ST LOUIS COUNTY AND THEN SE TO ERN WISC ZONES.
SMALL HAIL STILL POSSIBLE WITH SOME STORMS. AT THAT TIME... 85H
MSTR TRANSPORT AXIS IS FCST TO STRETCH FROM ST CROIX VALLEY TO
KOOCH COUNTY. WARM ADVECTION AT MID LVLS WILL TEND TO INHIBIT MOST
OF THE ACTIVITY ACROSS THE SRN CWA BY 18Z. WE SHOULD SEE A WELL
DEVELOPED BAND OF RAIN/THUNDERSTORMS FROM SE NDAK INTO NWRN MN.
THIS WILL BE OCCURRING ON NWRN SIDE OF SFC LOW IN AN AREA OF
DIVERGENCE ALOFT SUPPLIED BY RIGHT ENTRANCE REGION OF UPPER
JET.THIS CORRIDOR OF DEEP LAYER LIFT WILL TEND TO REMAIN OVER THE
SAME REGION THROUGH THE AFTERNOON. SIGNIFICANT RAINFALL MAY OCCUR
AND WE WILL NEED TO WATCH KOOCH/NWRN ITASCA COUNTY AREA FOR
ADDITIONAL UPDATES.
TONIGHT/TOMORROW...NRN BRANCH OF WESTERLIES WILL ADVANCE ACROSS CWA
OVERNIGHT. THIS WILL PUSH FRNTL SYSTEM THROUGH AS SFC HIGH BUILDS
INTO CWA FROM NRN PLAINS. DEEP LAYER DRYING REFLECTED IN
INTEGRATED RH PRODUCTS AND MDL XSECTS. SHOULD SEE MOSTLY SUNNY
SKIES ADVANCING ACROSS CWA AS DAY UNFOLDS. WITH INCREASED MIXING
DURING DAY...UNIDIRECTIONAL FLOW IN LOWEST 5K FT....SHOULD SEE
SOME GUSTY WINDS DEVELOPING. SFC DEWPOINTS MAY NEED LOWERING AS
MIX DOWN OF DRIER AIR OCCURS IN AFTN.
EXTENDED...TUESDAY NIGHT THROUGH SUNDAY...
UPPER LEVEL AND SFC RIDGING WILL COVER THE FA TUESDAY NIGHT THROUGH
FRIDAY. THE RIDGING MOVES JUST E OF THE AREA FRIDAY AFTERNOON
ALLOWING FOR A SOUTHERLY WAA/RETURN FLOW PATTERN TO BECOME
ESTABLISHED. A SHORT WAVE TROF WILL MOVE FROM THE NORTHERN PLAINS
FRIDAY NIGHT INTO THE GREAT LAKES SATURDAY NIGHT. IN THE
MEANTIME...AN ASSOCIATED SFC LOW MOVING THROUGH SOUTHERN CANADA WILL
PUSH A COLD FRONT THROUGH THE FA AND EXIT SATURDAY NIGHT. THIS
COMBINATION WARRANTS SOME POPS FRIDAY NIGHT THROUGH SUNDAY. BEST
INSTABILITY WILL BE FOUND OVER THE SOUTHERN THIRD OF THE AREA
SATURDAY AND HAVE A MENTION OF THUNDERSTORMS.
&&
.POINT TEMPS/POPS...
DLH 52 40 58 35 / 30 60 10 0
INL 52 36 58 30 / 60 60 10 0
BRD 63 41 61 34 / 40 60 10 0
HYR 63 42 61 33 / 10 60 20 0
ASX 58 41 57 34 / 30 60 20 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM....EOM
AREA FORECAST DISCUSSION
NWS DULUTH MN
641 AM CDT MON APR 2 2012
.AVIATION...12Z TAFS.
BKN MID DECK DEVELOPING OVER NE MN AND NW WI WILL AFFECT THE TAF
SITES THROUGH THIS FORECAST CYCLE. SHOWERS FROM THE MN ARROWHEAD
INTO NW WI TO MOVE E AND DISSIPATE. SFC TROF IN THE RED RIVER
VALLEY WILL MOVE INTO THE FA ALONG WITH MID LEVEL INSTABILITY AXIS.
SOME SHOWERS MAY FORM BY 15Z NEAR KINL...HOLDING OFF UNTIL LATER
THIS AFTERNOON NEAR KHIB/KBRD. INSTABILITY AXIS ALIGNS ITSELF OVER
THE AREA BETWEEN 18Z-21Z AND ALONG WITH THE SFC TROF WILL BE THE
FOCUS FOR THUNDERSTORMS. USED VCTS AT KBRD/KHYR AS TIMING OF
STORMS IS IN QUESTION AND CONFIDENCE IS LOW. PCPN WILL DIMINISH
FROM NW TO SE THIS EVENING WITH LOSS OF SOLAR/INSTABILITY.
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT MON APR 2 2012/
SHORT TERM...RUC ANALYSIS DOING GOOD JOB HIGHLIGHTING GENESIS
REGION OF CONVECTION THIS MORNING OVER WCTRL MN. MID LVL
INSTABILITY AXIS IS ALIGNED EAST ACROSS CWA FROM CASS LAKE TO TWIN
PORTS AND THEN SE TO NRN PRICE COUNTY. CONVECTION HAS TRAINED
ALONG THIS CORRIDOR WITH SMALL HAIL REPORTED AT TIMES. A
SECONDARY 70H THETAE MAX IS DEVELOPING ACROSS SRN KOOCH/NRN ITASCA
VICINITY AND NEW CONVECTION IS FORMING THERE AS WELL. AREA REMAINS
UNDER MID LVL RIDGE AXIS WITH A WEAK SHORTWAVE TROF LIFTING OVER
RIDGE AXIS.
TODAY...USED RUC AS SHORT TERM GUIDANCE FOR PLACING HIGHER POPS
ALONG AFOREMENTIONED INSTABILITY AXIS AS IT MOVES GRADUALLY NORTH
THIS MORNING. BY MIDDAY FOCUS OF CONVECTION MAY BE ALIGNED FROM
NWRN CWA TO NR ST LOUIS COUNTY AND THEN SE TO ERN WISC ZONES.
SMALL HAIL STILL POSSIBLE WITH SOME STORMS. AT THAT TIME... 85H
MSTR TRANSPORT AXIS IS FCST TO STRETCH FROM ST CROIX VALLEY TO
KOOCH COUNTY. WARM ADVECTION AT MID LVLS WILL TEND TO INHIBIT MOST
OF THE ACTIVITY ACROSS THE SRN CWA BY 18Z. WE SHOULD SEE A WELL
DEVELOPED BAND OF RAIN/THUNDERSTORMS FROM SE NDAK INTO NWRN MN.
THIS WILL BE OCCURRING ON NWRN SIDE OF SFC LOW IN AN AREA OF
DIVERGENCE ALOFT SUPPLIED BY RIGHT ENTRANCE REGION OF UPPER
JET.THIS CORRIDOR OF DEEP LAYER LIFT WILL TEND TO REMAIN OVER THE
SAME REGION THROUGH THE AFTERNOON. SIGNIFICANT RAINFALL MAY OCCUR
AND WE WILL NEED TO WATCH KOOCH/NWRN ITASCA COUNTY AREA FOR
ADDITIONAL UPDATES.
TONIGHT/TOMORROW...NRN BRANCH OF WESTERLIES WILL ADVANCE ACROSS CWA
OVERNIGHT. THIS WILL PUSH FRNTL SYSTEM THROUGH AS SFC HIGH BUILDS
INTO CWA FROM NRN PLAINS. DEEP LAYER DRYING REFLECTED IN
INTEGRATED RH PRODUCTS AND MDL XSECTS. SHOULD SEE MOSTLY SUNNY
SKIES ADVANCING ACROSS CWA AS DAY UNFOLDS. WITH INCREASED MIXING
DURING DAY...UNIDIRECTIONAL FLOW IN LOWEST 5K FT....SHOULD SEE
SOME GUSTY WINDS DEVELOPING. SFC DEWPOINTS MAY NEED LOWERING AS
MIX DOWN OF DRIER AIR OCCURS IN AFTN.
EXTENDED...TUESDAY NIGHT THROUGH SUNDAY...
UPPER LEVEL AND SFC RIDGING WILL COVER THE FA TUESDAY NIGHT THROUGH
FRIDAY. THE RIDGING MOVES JUST E OF THE AREA FRIDAY AFTERNOON
ALLOWING FOR A SOUTHERLY WAA/RETURN FLOW PATTERN TO BECOME
ESTABLISHED. A SHORT WAVE TROF WILL MOVE FROM THE NORTHERN PLAINS
FRIDAY NIGHT INTO THE GREAT LAKES SATURDAY NIGHT. IN THE
MEANTIME...AN ASSOCIATED SFC LOW MOVING THROUGH SOUTHERN CANADA WILL
PUSH A COLD FRONT THROUGH THE FA AND EXIT SATURDAY NIGHT. THIS
COMBINATION WARRANTS SOME POPS FRIDAY NIGHT THROUGH SUNDAY. BEST
INSTABILITY WILL BE FOUND OVER THE SOUTHERN THIRD OF THE AREA
SATURDAY AND HAVE A MENTION OF THUNDERSTORMS.
AVIATION...06Z TAFS
IFR/MVFR CEILINGS WILL OCCUR IN SPOTS THROUGH THE PERIOD...MOST LIKELY
AROUND LAKE SUPERIOR. SOME FOG WILL ALSO BE POSSIBLE...ALTHOUGH
SB`S HAVE INCREASED IN MOST AREAS DUE TO STRONG HIGH BUILDING
SOUTH THROUGH ONTARIO.
SHOWERS/STORMS WERE DEVELOPING JUST WEST OF KDLH...ON WEST TO NEAR
KDTL. PERSISTENT WAA/MOISTURE TRANSPORT SHOULD LEAD TO ADDITIONAL
SHOWER/STORM DEVELOPMENT OVERNIGHT INTO MONDAY. MVFR OR EVEN SOME
IFR CONDITIONS WILL BE POSSIBLE WITH ANY SHOWERS/STORMS. STORMS
SHOULD OCCUR MAINLY OVER NORTHEAST/NORTHERN MINNESOTA THROUGH
MUCH OF MONDAY...TRANSLATING EAST MONDAY NIGHT.
&&
.POINT TEMPS/POPS...
DLH 52 40 58 35 / 40 60 10 0
INL 51 36 58 30 / 60 60 10 0
BRD 63 41 61 34 / 40 60 10 0
HYR 62 42 61 33 / 20 60 20 0
ASX 57 41 57 34 / 50 60 20 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...CANNON
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1048 AM CDT MON APR 2 2012
.UPDATE...
UPDATED TO INCREASE HIGHS AHEAD OF FRONT SOME AREAS AND TO
REDUCE/DROP PRECIP CHCS THIS AFTERNOON.
&&
.DISCUSSION...
MORNING KOAX SOUNDING SHOWED VERY WARM TEMPERATURE LAYER CENTERED
ON H85 WITH WELL MIXED CAP ABOVE. QUESTION IS WHETHER FRONT CAN
BREAK CAP OVER NEBRASKA AND SOME CONFLICTING INFORMATION FROM
MODELS. LATEST RUC SOUNDING DID TO SOME DEGREE...EVEN IN ECNTRL
SECTIONS...WHILE 00Z GFS WAS MORE RESTRICTED TO SWRN FORECAST
AREA. SHORTER RANGE QPF FORECASTS FROM RUC/HRRR DEVELOPED NO
PRECIP OVER FORECAST AREA THROUGH 00Z WHILE LAST EVENINGS 4KM WRF
DID AS DID THE 06Z NAM/GFS. HOWEVER...12Z NAM REFRAINS FROM
SPREADING PRECIP INTO SRN ZONES UNTIL THIS EVENING. BASED ON
MORNING SOUNDING...FELT ANY CONVECTION THAT MAKES IT INTO
FORECAST AREA WILL EITHER DEVELOP LATE IN THE AFTN ON FRONT OVER
SWRN ZONES OR SW OF NEBRASKA AND THEN ATTEMPT TO BUILD INTO SERN
ZONES THIS EVENING. THUS POPS WERE DROPPED MUCH OF THE AREA N
THROUGH E OF OMA ALONG WITH FAR SERN NEBRASKA THIS AFTN AND
TRIMMED BACK ALL BUT SEVERAL SW COUNTIES FM OMAHA SWWD. ALSO
RAISED MAX TEMPS A BIT IN ERN ZONES BASED ON MORNING SOUNDING AND
BOOSTED WINDS A LITTLE BOTH AHEAD OF AND BEHIND FRONT.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 631 AM CDT MON APR 2 2012/
DISCUSSION...
WV IMAGERY SHOWING FEATURE OF CONCERN...DEEP LONGWAVE TROF...OVER THE
ROCKIES SLOWLY MIGRATING TO THE EAST THIS MORNING WHILE SFC LOW
PRESSURE WAS CENTERED IN NERN CO. MODELS IN DECENT AGREEMENT THAT THE
LONGWAVE TROF WILL FORM INTO A CLOSED LOW OVER THE SRN PLAINS AND
BECOME CUT OFF BY EARLY TUESDAY MORNING...THEN EVENTUALLY LIFTING
ACROSS THE CENTRAL PLAINS EARLY THURSDAY. FOR TODAY...ANTICIPATED
COLD FRONT WILL SWEEP INTO THE CENTRAL PLAINS AS CO SFC LOW TREKS
TOWARD THE MID MS VLY. VARIOUS TIME-SERIES PROGS PUT THE FRONT THRU
THE METRO-AREA SOMETIME EARLY THIS EVENING. PW VALUES AROUND 1.25"
AND KI 35-40 INDICATE ENVIRONMENT WILL BE MOISTURE RICH. THAT...IN
COMBINATION WITH FAVORABLE MUCAPE/EFF SRH/EFF BULK WIND DIFFERENCE
PARAMETERS SUGGEST LATE AFTN/EARLY EVENING SEVERE STORM DEVELOPMENT A
DISTINCT POSSIBILITY...PARTICULARLY AREAS SOUTH OF I-80.
FORTUNATELY...APPEARS THAT TOR THREAT WILL BE MINIMAL DUE TO ML LFC
PROGGED AOA 2200M.
PCPN CHANCES CONTINUE THEN TUESDAY THROUGH THURSDAY MAINLY SOUTH
AS AREA FALLS UNDER INFLUENCE OF CLOSED LOW DYNAMICS TREKKING
ACROSS KS.
OTHERWISE THIS COOLER AIRMASS FILTERING IN THIS WEEK WILL BRING
A NOTICEABLE CHANGE. NEVERTHELESS...NEAR NORMAL MAX TEMPS WILL BE
QUITE ATTAINABLE.
DEE
AVIATION...
12Z TAFS FOR KOFK...KLNK AND KOMA.
GUSTY SOUTH TO SOUTHWEST WINDS UP TO 25KTS WILL DEVELOP DURING THE
MORNING AHEAD OF A COLD FRONT MOVING INTO EASTERN NEBRASKA THIS
AFTERNOON. THAT FRONT SHOULD REACH KOFK AROUND 22Z...KLNK NEAR 01Z
AND KOMA NEAR 02Z. NORTHWEST WINDS GUSTING OVER 25KTS WILL FOLLOW
THE FRONT WITH CIGS DECREASING TO MVFR...WITH A GRADUAL LOWERING
TO BELOW FL020 AFTER 06Z. A FEW SHOWERS ARE ALSO POSSIBLE BEHIND
THE FRONT OVERNIGHT. THERE IS A SLIGHT CHANCE THUNDERSTORMS COULD
DEVELOP NEAR KOMA AND KLNK AFTER 21Z AS THE COLD FRONT APPROACHES.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
709 AM CDT MON APR 2 2012
.AVIATION...12Z KGRI TAF. OVERALL...CONFIDENCE IS A BIT LOWER THAN
USUAL WITH REGARD TO WIND AND CEILING TRENDS THROUGH THE PERIOD...AS
MODELS CONTINUE TO STRUGGLE WITH THE TIMING OF THE PRIMARY COLD
FRONTAL PASSAGE...AND IN GENERAL ARE SLOWING IT DOWN. AS A
RESULT...ANTICIPATE FAIRLY LIGHT SOUTH-SOUTHWESTERLY BREEZES
THIS MORNING...BEFORE NORTHWEST WINDS FINALLY KICK IN DURING THE
EARLY TO MID AFTERNOON HOURS BEHIND THE INITIAL FRONTAL PASSAGE.
HOWEVER...IT MAY BE UNTIL LATE AFTERNOON/EARLY EVENING BEFORE
POTENTIAL GUSTS TO AROUND 30KT OR HIGHER ARE FINALLY REALIZED.
MOVING TO CEILING AND PRECIPITATION TRENDS...KEPT THEME FROM
PREVIOUS FORECAST OF A FAIRLY SOLID CEILING IN THE 2000-3000 FT
RANGE SETTLING IN DURING THE EVENING AND OVERNIGHT HOURS...BUT
TIMING COULD EASILY BE OFF BY A FEW HOURS. FINALLY...REGARDING
PRECIPITATION CHANCES...THE EVENING HOURS COULD SEE LEGITIMATE
STRONG THUNDERSTORM ACTIVITY WITHIN 50-75 MILES SOUTH-SOUTHEAST OF
KGRI...BUT AT THIS TIME EXPECT THIS TO STAY FAR ENOUGH AWAY TO
OMIT A MENTION. DID HOWEVER INTRODUCE A VICINITY SHOWER MENTION
FOR THE LATE NIGHT HOURS. STAY TUNED FOR PLENTY OF POTENTIAL
TWEAKING TO THE TAF OVER THE NEXT 24 HOURS...
&&
.PREV DISCUSSION... /ISSUED 419 AM CDT MON APR 2 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT. THE PATTERN ALOFT
REVEALED AN UPPER TROUGH IN THE ROCKIES WITH THE MID/UPPER
CIRCULATION CLOSING OFF NEAR THE FOUR CORNERS REGION. AHEAD OF THIS
SYSTEM...SOUTHWEST FLOW WAS IN PLACE ACROSS THE CENTRAL PLAINS WHILE
UPPER RIDGE HAD SHIFTED EAST OF THE MISSOURI RIVER. AT THE
SURFACE...LOW PRESSURE WAS CENTERED IN FAR NORTHWEST KANSAS...WITH
COOL FRONTAL BOUNDARY EXTENDING FROM VTN TO KSNY...AND DRYLINE
EXTENDED ACROSS EASTERN CO. PRESSURE RISES BEHIND THE FRONT BEHIND
THE FRONT AVERAGED 3-5MB.
THERE HAVE BEEN SOME DISTINCT CHANGES IN FRONTAL TIMING...WINDS AND
POTENTIAL FOR CONVECTION TODAY. SURFACE FRONT STILL ENTERS OUR
WESTERN CWA AROUND 12Z...BUT SLOWS AND STALLS ACROSS OUR SOUTHEAST
CWA AROUND MID AFTERNOON. INSTABILITY PROGS INDICATE MUCAPE AROUND
1500 J/KG IN OUR FAR SOUTHEAST CWA FOR A FEW HOURS WITH HIGHER CAPE
AXIS FARTHER SOUTHEAST AHEAD OF THE BOUNDARY...AND A BRIEF PERIOD OF
EFFECTIVE SHEAR OF 30 TO 40KTS RESIDE ALONG THE BOUNDARY...GENERALLY
BETWEEN 21 AND 00Z. AS THE BOUNDARY STALLS IN OUR SOUTHEAST...CAN
NO LONGER RULE OUT CONVECTIVE POTENTIAL AND A WINDOW OF
OPPORTUNITY FOR SEVERE WEATHER WITH STORMS CAPABLE OF PRODUCING
LARGE HAIL/DAMAGING WINDS. 4KM SPC WRF DEVELOPS CONVECTION ACROSS
OUR SOUTHERN CWA IN VCNTY OF BOUNDARY AND WITH CONTINUING TRENDS
OF FRONT SLOWING DOWN...HAVE RETURNED TSTMS TO FORECAST.
ALSO DUE TO SLOWER FRONTAL PROGRESSION TODAY...THIS ALSO HAS AN
IMPACT ON STRENGTH OF WINDS ACROSS OUR REGION. THE CORRIDOR OF
STRONGEST PRESSURE RISES THIS MORNING SLIDE SOUTH FROM WESTERN
NEBRASKA INTO WESTERN KANSAS AND SFC GRADIENT REMAINS TIGHTEST
ACROSS THE WESTERN HALF OF NEBRASKA INTO NW KANSAS. FRONT DOES NOT
REACH OUR EASTERN AND SOUTHEAST COUNTIES UNTIL THIS AFTERNOON OR
EARLY EVENING AND WINDS WILL INITIALLY BE GUSTY OUT OF THE SOUTH BUT
NOT AT WIND ADVISORY CRITERIA. AS FRONT PUSHES THRU OUR SOUTHEAST
CWA IN THE EVENING...A SECONDARY SURGE OF PRESSURE RISES AND
CORRIDOR OF 40KT MID LEVEL WINDS MOVE THRU BEGINNING GENERALLY
AROUND 00Z AND LINGERING/SPREADING SOUTHWARD UNTIL AROUND
MIDNIGHT. WHAT THIS MEANS IS THAT REACHING WIND ADVISORY CRITERIA
ESPECIALLY IN OUR EAST/SOUTHEAST IS LOOKING LESS LIKELY UNTIL
POTENTIALLY CLOSER TO 00Z WITH SECONDARY SURGE OF FRONT/PRESSURE RISES.
OUR WESTERN COUNTIES WILL STILL STAND A BETTER CHC FOR WIND
ADVISORY CRITERIA BUT IN ESSENCE MAY BE MORE OF A BUFFER TO THE
EVEN HIGHER WINDS ACROSS WESTERN NEBRASKA AND KANSAS. FOR
HEADLINE...OPTIONS ARE TO EITHER CANCEL EASTERN/SOUTHEAST PORTION
OR HOLD OFF ON TIMING UNTIL THE EVENING HOURS. HAVE OPTED TO
REMOVE WIND ADVISORY IN THE EAST AND MAINTAIN A BUFFER IN THE
WEST. LATEST HRRR SUGGESTS STRONGER WINDS COULD HOLD OFF EVEN IN
OUR WEST UNTIL AFTN WHILE THE INITIALLY STRONGER WINDS WILL BE FM
THE SOUTH IN OUR EASTERN COUNTIES.
OTHER CHANGE IN MODELS...WHICH HAS BEEN A GENERAL TREND AS WELL...IS
THE FARTHER NORTH TRACK OF THE UPPER LOW AS IT LIFTS FM THE TX/OK
PANHANDLES TUESDAY. GENERAL CONSENSUS IS THAT LOW WILL LIFT AND
TRACK ACROSS KANSAS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AND THE
ECMWF REMAINS SLOWER WITH PROGRESSION WHICH COULD POTENTIALLY LINGER
PCPN CHCS BEYOND WEDNESDAY NIGHT. LATEST TRACK PROMISES TO PROVIDE
A DECENT RAIN EVENT ACROSS THE CENTRAL PLAINS MAINLY FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. POPS HAVE BEEN TRENDED UPWARD INTO
LIKELY CATEGORY...AND SOME DECENT SPRING RAINFALL TOTALS ARE
POSSIBLE WITH PRECIPITABLE WATER VALUES AVERAGING 0.75 TO JUST OVER
AN INCH. HAVE KEPT THUNDER WORDING OUT AS INSTABILITY PARAMETERS
ARE RATHER MEAGER BUT WOULD NOT BE SURPRISED TO SEE AN OUTSIDE
LIGHTNING STRIKE HERE OR THERE...ESPECIALLY IN OUR SOUTHEAST WHERE
MUCAPES ARE NOT ZERO...JUST RATHER LOW.
LONG TERM...THURSDAY THROUGH SUNDAY. PRIMARY FOCUS THROUGH THIS
4-DAY PERIOD IS THE RISK FOR THUNDERSTORMS IN THE FRI-SAT TIME
FRAME...BUT MAINLY CENTERED FRIDAY NIGHT AND NOT EVEN IN LIKELY
POP TERRITORY YET. ALTHOUGH NOT NEARLY AS WARM AS LATELY...HIGH
TEMPS THROUGH THIS PERIOD SHOULD NONETHELESS AVERAGE SOLIDLY IN THE
60S MOST AREAS...OR STILL SLIGHTLY ABOVE NORMAL FOR EARLY APRIL. AS
FOR OVERNIGHT LOWS...WILL HAVE TO KEEP AN EYE OUT AS EARLY AS SAT
NIGHT FOR POSSIBLE FROST POTENTIAL.
STARTING OFF THURSDAY...00Z ECMWF/GFS RUNS ARE IN DECENT AGREEMENT
DEPICTING A DEPARTING MID LEVEL CLOSED LOW GENERALLY WANDERING
SOMEWHERE OVER MO. AT THE SAME TIME...A FAIRLY EXPANSIVE UPSTREAM
TROUGH WILL BE CENTERED OVER THE WESTERN 1/3 OF THE CONUS. AT
LEAST FOR NOW...LEFT THURSDAY DAYTIME DRY...ALTHOUGH THERE ARE
SOME HINTS THAT AT LEAST SOME EASTERN AREAS COULD STILL BE PRONE
TO SOME LINGERING LIGHT RAIN SHOWERS. FOR NOW THOUGH WILL STAY THE
COURSE AND REMAIN TRUE TO THE DRY FCST INITIALIZED BY THE ALLBLEND
MODEL PROCEDURE. FOR HIGH TEMPS...NUDGED DOWN A FEW DEGREES MOST
AREAS GIVEN PREDOMINANT EASTERLY LOW LEVEL FLOW...WITH THE
MAJORITY OF THE CWA IN THE 62-65 RANGE. KEPT THURS NIGHT DRY AS
PRIMARY LOW LEVEL JET AXIS AND RESULTANT FOCUS FOR POSSIBLE
CONVECTION APPEARS TO REMAIN AT LEAST SLIGHTLY WEST OF THE CWA.
FRIDAY/FRIDAY NIGHT...THIS 24 HOUR PERIOD APPEARS TO FEATURE THE
PRIMARY RISK FOR THUNDERSTORMS IN THE LONG TERM...ESPECIALLY ON
FRIDAY NIGHT. DURING THE DAY...SOUTHEAST WINDS WILL PICK UP INTO
BREEZY TERRITORY AS PRESSURES FALL OVER THE HIGH PLAINS...BUT AT
THIS TIME SPEEDS LOOK TO REMAIN BELOW ADVISORY CRITERIA. ALLBLEND
PROCEDURE INTRODUCED A SLIGHT CHANCE OF STORMS DURING THE DAY
ACROSS WESTERN COUNTIES...AND OPTED TO RUN WITH IT...ALTHOUGH
CONFIDENCE IS RATHER LOW GIVEN EXPECTATION OF WEAK FORCING AND
SOME CAPPING...DESPITE THE ECMWF AND GFS BOTH ADVERTISING A
NARROW...FAIRLY WEAK INSTABILITY AXIS SETTING UP NEAR THE
SOUTHERN/WESTERN EDGES OF THE CWA THROUGH THE DAY. IN ALL HONESTY
THOUGH...THESE SLIGHT CHANCES DURING THE DAY ARE ALREADY ON
SOMEWHAT SHAKY GROUND RIGHT OUT OF THE GATE. BETTER
CHANCES...ALTHOUGH STILL ONLY IN THE 30-40 PERCENT RANGE AT THIS
TIME...ARRIVE FRIDAY NIGHT AS FORCING FROM THE LEADING SHORTWAVE
EMANATING FROM THE WESTERN CONUS TROUGH SWINGS ALONG A TRACK FROM
WY/NORTHERN CO ACROSS WESTERN NE INTO SD. ALTHOUGH THIS TAKES THE
BULK OF THE LARGE SCALE FORCING NORTH OF THE CWA...BOTH MODELS
GENERATE QPF...WITH THE GFS ADVERTISING A SURGE OF INSTABILITY
DURING THE NIGHT...WITH MUCAPE VALUES CLIMBING TO AROUND 1500 J/KG
IN THE PRESENCE OF AT LEAST 40KT OF DEEP LAYER SHEAR. FOR NOW WILL
INTRODUCE A STRONG STORM MENTION IN THE HWO...BUT WILL NEED TO
KEEP A CLOSE EYE ON SEVERE POTENTIAL OVER NEXT FEW DAYS.
SATURDAY...MID RANGE MODELS CONTINUE TO AGREE ON THE LARGER SCALE
PATTERN...WITH THE MAIN MID LEVEL WAVE CROSSING THE DAKOTAS TOWARD
MN...WHILE A SURFACE COLD FRONT TRACKS ACROSS THE CWA AND USHERS
IN DRIER/MORE STABLE AIR. ALLBLEND MODEL KEPT SOME TOKEN SLIGHT
POPS ACROSS FAR NORTHEAST AND SOUTHEAST PORTIONS OF THE CWA DURING
THE DAY...AND WILL LET IT RIDE FOR NOW.
SAT NIGHT/SUNDAY...CONFIDENCE IS RATHER HIGH AT THIS TIME RANGE
THAT DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE DEPARTING
WAVE...ALTHOUGH MODELS START TO DIVERGE ALOFT WITH THE ECMWF
ADVERTISING BROAD WEST-NORTHWEST FLOW WHILE THE GFS IS MORE WEST-
SOUTHWEST. DOWN LOW HOWEVER...THERE IS A DECENT SIGNAL FOR HIGH
PRESSURE TO RULE THE SCENE ON SATURDAY NIGHT WITH FAIRLY LIGHT
WINDS. ALTHOUGH CURRENT FORECAST KEEPS LOWS UP IN THE UPPER 30S-
LOW 40S FOR MOST OF THE CWA...WILL HAVE TO MONITOR FOR THE
POTENTIAL FOR A MORE WIDESPREAD LOW-MID 30S...WHICH COULD AT LEAST
BRING SOME FROST POTENTIAL INTO PLAY. CERTAINLY TOO EARLY AT THIS
TIME TO FORMALLY PUT IT IN THE FORECAST. PEEKING AHEAD A BIT INTO
THE WEEK OF APRIL 9TH...COULD BE A FEW MORE RISKS FOR OVERNIGHT
TEMPS DROPPING DOWN INTO AT LEAST THE FROST POSSIBILITY
RANGE...WHICH IS RIGHT IN LINE WITH CLIMATOLOGY FOR MID APRIL.
AVIATION...06Z KGRI TAF. WIND WILL BE THE BIGGEST FACTOR FOR THIS
FORECAST. EAST TO SOUTHEAST WIND WILL PREVAIL OVERNIGHT AND WILL
CONTINUE TO BE A BIT ON THE BREEZY SIDE. A COLD FRONT WILL MOVE IN
TOWARD MID-MORNING AND WILL SWITCH WIND DIRECTION TO THE NORTH
NORTHWEST AND WILL BECOME VERY GUSTY FROM STRONG HEIGHT
RISES...ESPECIALLY TOWARD EVENING. ANY PRECIPITATION SHOULD HOLD
OFF TO THE SOUTH AND WELL AFTER THE FRONT PASSES THROUGH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 11 PM CDT THIS EVENING
FOR NEZ061-073-083.
WIND ADVISORY FROM 11 AM THIS MORNING TO 11 PM CDT THIS EVENING
FOR NEZ039-046-060-072-082.
KS...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 11 PM CDT THIS EVENING
FOR KSZ005-017.
&&
$$
SHORT TERM...FAY
LONG TERM/AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
657 AM EDT MON APR 2 2012
.SYNOPSIS...
SKIES WILL GRADUALLY CLEAR TODAY AS HIGH PRESSURE BUILDS ACROSS THE
REGION FROM CANADA. TEMPERATURES WILL DROP BELOW FREEZING ACROSS THE
REGION UNDERNEATH THE HIGH PRESSURE RIDGE. THEN A WEAK SYSTEM WILL
BRING A SMALL CHANCE OF SHOWERS TUESDAY BEFORE DRY WEATHER RETURNS
FOR THE REST OF THE WEEK ALONG WITH SEASONABLE TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
FOR TODAY...THE MAIN FORECAST CHALLENGE WILL BE DETERMINING EXACTLY
WHEN SKIES WILL CLEAR OUT. AT DAYBREAK SKIES ARE VARIABLE...WITH
PATCHES OF LOW CLOUDS AND CLEARING. THERE IS ALSO SOME PATCHY FOG
IN AREAS WHICH HAVE CLEARED. EXPECT LAKE ONTARIO AND THE IMMEDIATE
SHORELINE TO STAY CLEAR. A BIT SOUTH OF THIS...THERE IS STILL
QUITE A BIT OF MOISTURE...SO CLOUDS MAY FILL BACK IN TO SOME
EXTENT THROUGH THE MORNING HOURS...BEFORE A MORE COMPREHENSIVE
CLEARING THIS AFTERNOON. THE NAM/GFS HAVE BEEN TOO QUICK TO CLEAR
THINGS OUT...WITH THE RUC BUFKIT SHOWING LINGERING MOISTURE UNTIL
LATE MORNING WHEN DRIER AIR BUILDS IN. EXPECT HIGHS TO RANGE FROM THE
UPPER 40S TO AROUND 50.
FOR TONIGHT...HIGH PRESSURE WILL BUILD ACROSS THE REGION...AND WITH
DRIER AIR IN PLACE...SEE NO REASON WHY WE WILL NOT EXPERIENCE GOOD
RADIATIONAL COOLING CONDITIONS. WITH CONFIDENCE IN RADIATIONAL
COOLING...WILL FAVOR THE COLDER MOS NUMBERS OVER BIAS CORRECTED
GRIDS FOR LOWS TONIGHT. THIS SHOULD RESULT IN FREEZING TEMPERATURES
ACROSS THE REGION...WITH MANY SPOTS FURTHER FROM THE LAKE SHORE
LIKELY TO DROP INTO THE 20S. BECAUSE OF THIS...WILL TRANSITION THE
FREEZE WATCH INTO A FREEZE WARNING.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AFTER A COLD AND FROSTY START TO THE DAY...TUESDAY WILL FEATURE A
GRADUAL INCREASE IN MID AND HIGH LEVEL CLOUDS AS A WEAK SURFACE
TROUGH MOVES EAST TOWARD THE LOWER GREAT LAKES. THE MODELS CONTINUE
TO SUGGEST THAT THE DEEPEST LOW LEVEL MOISTURE WILL REMAIN WELL
SOUTH OF NEW YORK STATE...WHILE THE BEST UPPER LEVEL SUPPORT STAYS
TO OUR NORTH IN THE VICINITY OF THE DIGGING UPPER LEVEL TROUGH
OVER ONTARIO PROVINCE. THIS CONFIRMS THE TREND OF PREVIOUS MODEL
RUNS OF A DRY FORECAST.
WARM ADVECTION IN ADVANCE OF THE TROUGH WILL BRING SOME MODERATION
IN TEMPERATURES ON TUESDAY...WITH HIGH TEMPERATURES LIKELY RANGING
FROM THE LOWER TO MID 50S ACROSS THE NORTH COUNTRY TO THE LOWER 60S
ACROSS THE SOUTHERN TIER AND UPPER GENESEE VALLEY.
AS THE TROUGH CROSSES THE AREA TUESDAY NIGHT...IT LOOKS LIKE IT WILL
TAP SOME OF THE DEEPER MOISTURE TO OUR SOUTH AND PRODUCE A FEW
SHOWERS. MODEST COOL AIR ADVECTION WILL TAKE PLACE BEHIND THE TROUGH
AND ALLOW TEMPERATURES TO INTO THE 30S. THIS COULD RESULT IN A MIX
OF RAIN AND SNOW SHOWERS FOR A BRIEF TIME ACROSS THE NORTH COUNTRY
WHERE TEMPERATURES ALOFT WILL BE COOLING FASTER.
ON WEDNESDAY...THE UPPER LEVEL TROUGH IS FORECAST DEEPEN OVER
SOUTHERN QUEBEC AND NORTHERN NEW ENGLAND...WITH A FAIRLY SIGNIFICANT
VORT LOBE DROPPING SOUTHEAST ACROSS CENTRAL AND EASTERN NEW YORK.
WITH JUST ENOUGH MOISTURE IN PLACE...THE LIFT ASSOCIATED WITH THIS
FEATURE MAY BE JUST ENOUGH TO SQUEEZE OUT A FEW SHOWERS ACROSS THE
NORTH COUNTRY AND PERHAPS THE EASTERN FINGER LAKES. FARTHER TO THE
WEST...A DRIER AIRMASS WILL BE IN PLACE. THIS SHOULD RESULT IN
MAINLY DRY CONDITIONS. ONGOING COLD AIR ADVECTION ASSOCIATED WITH
THE DEEPENING UPPER LEVEL TROUGH WILL RESULT IN A NOTICEABLY COOLER
AND MORE SEASONABLE DAY THAN TUESDAY...WITH DAYTIME HIGH
TEMPERATURES REACHING THE MID 40S TO LOWER 50S.
ANY SHOWERS SHOULD THEN DIE OUT FAIRLY QUICKLY WITH THE DEPARTURE OF
THE VORT LOBE AND LOSS OF HEATING WEDNESDAY EVENING...LEAVING BEHIND
A DRY BUT ALSO CHILLY NIGHT...WITH WIDESPREAD LOWS IN THE UPPER 20S
TO LOWER 30S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
IN THE EXTENDED PERIOD...THE GUIDANCE REMAINS IN GOOD AGREEMENT THAT
THE MAIN UPPER LEVEL TROUGH WILL LINGER ACROSS THE REGION INTO
FRIDAY...BEFORE FINALLY SLIDING OFF TO THE EAST NEXT WEEKEND AND
ALLOWING UPPER-LEVEL RIDGING TO GRADUALLY BUILD EAST FROM THE UPPER
MIDWEST/ WESTERN GREAT LAKES. MEANWHILE AT THE SURFACE...HIGH
PRESSURE AND DRIER AIR WILL CONTINUE TO BUILD SOUTHEAST FROM CENTRAL
CANADA... EVENTUALLY CRESTING ACROSS THE AREA ON SUNDAY.
UNDER THIS PATTERN...DRY AND SEASONABLY COOL WEATHER SHOULD REMAIN
THE GENERAL RULE FOR BOTH THURSDAY AND FRIDAY. TEMPERATURES SHOULD
AVERAGE OUT CLOSE TO OR A LITTLE BELOW SEASONAL NORMALS BOTH
DAYS...WITH A WIDESPREAD FROST OR FREEZE POSSIBLE BOTH THURSDAY AND
FRIDAY NIGHTS.
THEREAFTER...DRY WEATHER SHOULD CONTINUE THROUGH NEXT WEEKEND...
ALONG WITH A WARMING TREND AS RIDGING BUILDS ACROSS THE AREA AT ALL
LEVELS. WITH THE MEDIUM RANGE GUIDANCE CONTINUING TO SHOW BOTH
RUN-TO-RUN AND MODEL-TO-MODEL INCONSISTENCIES WITH THE EXTENT OF
THIS WARMING TREND...FOR NOW WILL CONTINUE TO AIM A BIT ON THE
CONSERVATIVE SIDE FOR TEMPS...INDICATING HIGHS REACHING INTO THE MID
AND UPPER 50S BY SATURDAY...AND THE UPPER 50S TO LOWER 60S BY SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
THROUGH THIS MORNING...MOISTURE STILL LINGERS IN THE BOUNDARY
LAYER. THROUGH 15Z MAY SEE A BRIEF LOWERING OF CONDITIONS IN
CIGS/VSBY WITH SUNRISE...BUT EXPECT DRIER AIR TO MOVE IN LATE
MORNING...WHICH WILL SCATTER OUT CLOUDS...GIVING WAY TO SKC THIS AFTERNOON.
VFR CONDITIONS TONIGHT UNDER A STRONG HIGH PRESSURE RIDGE.
OUTLOOK...
TUESDAY...VFR.
TUESDAY NIGHT...VFR/MVFR WITH CHANCE SHOWERS.
WEDNESDAY...MAINLY VFR WITH CHANCE SHOWERS ACROSS THE NORTH COUNTRY.
THURSDAY AND FRIDAY...VFR.
&&
.MARINE...
NW WINDS AROUND 15 KTS ON THE EASTERN HALF OF LAKE ONTARIO WILL
RESULT IN MARGINAL SMALL CRAFT CONDITIONS. STRONGEST FLOW WILL BE
THROUGH 12Z...SO WILL HANG ONTO THE SCA HEADLINE ON THE EASTERN HALF
OF THE LAKE FOR NOW...BUT MAY BE ABLE TO DROP EARLY IF WINDS DO NOT
INCREASE A BIT.
AFTER THIS...HIGH PRESSURE BUILDS IN...WITH A FAIRLY EXTENDED PERIOD
OF GENERALLY LIGHT WINDS ON THE LAKES EXPECTED. PERSISTENT RIDGING
MAY KEEP THE WATERS FREE OF HEADLINES THROUGH THE END OF THE WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT TUESDAY FOR
NYZ001>006-010-011-013-014-019-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LOZ043-
044.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/TJP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1039 AM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1039 AM MONDAY...
UPDATE: CLEARING ALONG THE I-40 CORRIDOR HAS ALLOWED TEMPS TO REACH
THE LOW TO MID 70S IN THAT AREA. CLOUD COVER ACROSS THE SOUTHWEST
AND ALONG THE NC/VA BORDER HAVE KEPT TEMPS IN THE MID 60S. AS OF 14Z
THE BACKDOOR COLD FRONT WAS STRETCHED FROM DANVILLE VA SOUTH AND
EAST ACROSS THE AREA...HANGING OUT JUST EAST OF RDU... SMITHFIELD...
AND GOLDSBORO. DEWPOINTS BEHIND THE FRONT ARE CRASHING INTO THE 40S
AND LOW 50S...WITH TEMPS IN THE LOW TO MID 60S. SOME LIGHT SHOWERS
HAVE STARTED IMPINGE ON THE SOUTHWESTERN EXTENT OF THE AREA. THIS
CLOUD COVER AND SHOWERS MAY ACT TO KEEP TEMPS FROM RISING AS HIGH AS
PREVIOUSLY THOUGHT...THUS HAVE LOWERED HIGH ACROSS THE SOUTHWEST TO
AROUND 81 DEGREES. WITH THE CLEARING ACROSS THE I-40 CORRIDOR AND
TEMPS ALREADY IN THE LOW 70S HAVE INCREASED HIGHS SLIGHTLY TO THE
MID 70S.
PREVIOUS DISCUSSION:
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. GIVEN WARM ADVECTION OVERNIGHT...EXPECT LOWS IN THE MID
TO UPPER 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 635 AM MONDAY...
24-HR TAF PERIOD:
A BACKDOOR COLD FRONT WILL APPROACH THE AREA FROM THE NORTH THROUGH
12Z...THEN PROGRESS SOUTHWEST THROUGH CENTRAL NC TODAY. THE FRONT IS
EXPECTED TO STALL OUT OVER WESTERN NC/SC LATER THIS EVENING. EXPECT
A POTENTIAL FOR MVFR CONDITIONS ASSOC/W ISOLD CONVECTION THIS
MORNING (BETWEEN ROUGHLY 12-17Z) AND A PERIOD OF MVFR CEILINGS
ALONG/BEHIND THE BACKDOOR COLD FRONT BETWEEN 13-19Z. OTHERWISE...
EXPECT VFR CONDITIONS TO PREDOMINATE. SOUTHWESTERLY WINDS AT 5-10 KT
AT THE BEGINNING OF THE TAF PERIOD WILL BECOME WESTERLY BY OR
SHORTLY AFTER 12Z...THEN VEER TO THE NORTH/NORTHEAST AND INCREASE TO
10-15 KT WITH GUSTS UP TO 20 KT IN ASSOC/W THE BACKDOOR COLD FRONTAL
PASSAGE BETWEEN ROUGHLY 13-18Z. WINDS WILL BECOME EASTERLY AT ~5 KT
OR LIGHT/VARIABLE FROM SUNSET THIS EVENING THROUGH SUNRISE TUE
MORNING.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
THERE IS A GOOD PROBABILITY THAT MVFR CEILINGS WILL OVERSPREAD THE
AREA FROM SW-NE OR W-E AS THE STALLED FRONT LIFTS BACK THROUGH
CENTRAL NC AS A WARM FRONT DURING THE DAY TUE. A PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE EARLY WED MORNING (06-12Z) IN ASSOC/W WARM
ADVECTION UNDER THE NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND
STORMS ARE EXPECTED DURING THE DAY WED IN ADVANCE OF ANOTHER
BACKDOOR COLD FRONT APPROACHING THE AREA FROM THE NORTH. A PROLONGED
PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN
ASSOC/W LOW-LEVEL NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED
COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC/VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
639 AM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 325 AM MONDAY...
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. GIVEN WARM ADVECTION OVERNIGHT...EXPECT LOWS IN THE MID
TO UPPER 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 635 AM MONDAY...
24-HR TAF PERIOD:
A BACKDOOR COLD FRONT WILL APPROACH THE AREA FROM THE NORTH THROUGH
12Z...THEN PROGRESS SOUTHWEST THROUGH CENTRAL NC TODAY. THE FRONT IS
EXPECTED TO STALL OUT OVER WESTERN NC/SC LATER THIS EVENING. EXPECT
A POTENTIAL FOR MVFR CONDITIONS ASSOC/W ISOLD CONVECTION THIS
MORNING (BETWEEN ROUGHLY 12-17Z) AND A PERIOD OF MVFR CEILINGS
ALONG/BEHIND THE BACKDOOR COLD FRONT BETWEEN 13-19Z. OTHERWISE...
EXPECT VFR CONDITIONS TO PREDOMINATE. SOUTHWESTERLY WINDS AT 5-10 KT
AT THE BEGINNING OF THE TAF PERIOD WILL BECOME WESTERLY BY OR
SHORTLY AFTER 12Z...THEN VEER TO THE NORTH/NORTHEAST AND INCREASE TO
10-15 KT WITH GUSTS UP TO 20 KT IN ASSOC/W THE BACKDOOR COLD FRONTAL
PASSAGE BETWEEN ROUGHLY 13-18Z. WINDS WILL BECOME EASTERLY AT ~5 KT
OR LIGHT/VARIABLE FROM SUNSET THIS EVENING THROUGH SUNRISE TUE
MORNING.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
THERE IS A GOOD PROBABILITY THAT MVFR CEILINGS WILL OVERSPREAD THE
AREA FROM SW-NE OR W-E AS THE STALLED FRONT LIFTS BACK THROUGH
CENTRAL NC AS A WARM FRONT DURING THE DAY TUE. A PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE EARLY WED MORNING (06-12Z) IN ASSOC/W WARM
ADVECTION UNDER THE NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND
STORMS ARE EXPECTED DURING THE DAY WED IN ADVANCE OF ANOTHER
BACKDOOR COLD FRONT APPROACHING THE AREA FROM THE NORTH. A PROLONGED
PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN
ASSOC/W LOW-LEVEL NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED
COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...VINCENT
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
636 AM CDT MON APR 2 2012
.DISCUSSION.../ISSUED AT 500 AM CDT/
CURRENTLY SEEING A COLD FRONT PUSHING INTO OUR WESTERN CWA...HAVING
JUST PUSHED THROUGH CHAMBERLAIN...AND A WARM FRONT DRAPED FROM EAST
OF HURON SOUTH ACROSS SIOUX FALLS INTO NORTHWEST IOWA. EXPECTATION
IS THAT THIS WARM FRONT WILL CONTINUE TO SLOWLY DRIFT
SOUTHWEST...WITH THE AREA OF LOW STRATUS ACCOMPANYING IT. GUIDANCE
CONTINUES TO SLOW DOWN THE PROGRESSION OF THE COLD FRONT. MODELS
COMING INTO AGREEMENT THAT IT WILL WILL SLOWLY PUSH EAST THROUGH THE
DAY...NOT PASSING THROUGH SIOUX FALLS UNTIL 20-22Z...AND THE EASTERN
EDGE OF THE CWA 2-4Z. THIS WILL IMPACT TODAYS TEMPERATURE AND WIND
POTENTIAL.
TEMPERATURES ARE A BIG QUESTION MARK WITH A LARGE SPREAD IN THE
GUIDANCE TODAY. WITH THE SLOWER ARRIVAL OF THE COLD FRONT...RAISED
TEMPERATURES SEVERAL DEGREES IN THE WEST. MEANWHILE...FROM SIOUX
FALLS TO SIOUX CITY AND POINTS EAST...TEMPERATURES DEPEND ON
PROGRESSION OF THE WARM FRONT AND ATTENDANT LOW CLOUDS. THE HRRR HAS
PERFORMED FAIRLY WELL THE PAST COUPLE DAYS WITH THE EVOLUTION OF
THE WARM FRONT AND CLOUDS. IT LIFTS THE FRONT NORTH ALMOST THROUGH
THE ENTIRE CWA...RESULTING IN HIGHS IN THE 80S FROM YANKTON TO SIOUX
FALLS AND POINTS EAST...WITH NEAR 90 ONCE AGAIN IN SIOUX CITY. THIS
IS THE WARMEST MODEL SOLUTION...BUT THE NAM AND ECMWF ARE ONLY A FEW
DEGREES COOLER. THE LOW LEVEL MOISTURE AND STRATUS WILL BE A BIT
DEEPER THIS MORNING COMPARED TO LAST...SO THINK IT MAY TAKE A BIT
LONGER FOR CLOUDS TO ERODE. BUT GIVEN WHAT HAS HAPPENED THE PAST FEW
DAYS...THE SLOWER COLD FRONT...AND MODEL AGREEMENT...CURRENT
THINKING IS THAT THEY DO INDEED ERODE...ALLOWING FOR ANOTHER VERY
WARM DAY WITH HIGHS IN THE UPPER 70S TO MID 80S ACROSS EXTREME
SOUTHEAST SOUTH DAKOTA AND NORTHWEST IOWA. GIVEN UNCERTAINTY...DID
NOT GO QUITE AS WARM AS WARMEST SOLUTIONS...BUT WOULD NOT BE
SURPRISED IF TEMPS END UP A FEW DEGREES WARMER THAN CURRENT
FORECAST. ON THE OTHER HAND...IF THE LOW CLOUDS STAY LOCKED IN
TEMPERATURES WILL BE MUCH COOLER THAN FORECAST...ALTHOUGH SEE THIS
AS A LOWER PROBABILITY EVENT AT THIS TIME.
NEXT UP IS THE WINDS. WINDS WILL BECOME STRONG BEHIND THE COLD
FRONT. 900MB WINDS ARE EXPECTED TO BE IN THE 30 TO 40 KTS RANGE. THE
COMBINATION OF DECENT LOW LEVEL CAA AND PRESSURE RISES WILL HELP
PROMOTE MIXING AND THE TRANSFER OF THESE WINDS TO THE SURFACE. A
BORDERLINE WIND ADVISORY EVENT...BUT WILL KEEP THE CURRENT ADVISORY
MAINLY AS IS...WITH SUSTAINED WINDS APPROACHING 30 MPH FOR A PERIOD
IN THE WEST...WITH A FEW GUSTS AROUND 40 MPH. DID CUT ONE ROW OF
COUNTIES OFF THE ADVISORY GIVEN THE SLOWER MOVEMENT OF THE FRONT AND
A SLIGHTLY WEAKER CORE OF LOW LEVEL WINDS.
PRECIP CHANCES LOOK TO BE CLOSE TO ZERO OUT AHEAD OF THE FRONT. SOME
ELEVATED CAPE IN OUR FAR NORTHWEST...BUT A STRONG CAPPING INVERSION
AROUND 750MB WILL PREVENT ANY ELEVATED CONVECTION. DEEP LOW LEVEL
MOISTURE BEHIND THE FRONT WILL ALLOW FOR DRIZZLE AND LIGHT
SHOWERS...MAINLY NORTH OF INTERSTATE 90 AND WEST OF INTERSTATE 29.
EXPECT THIS AREA OF DRIZZLE TO BEGIN TO DISSIPATE TONIGHT AS THE
MOISTURE LAYER BECOMES SHALLOW AND BEGINS TO ERODE AWAY FROM WEST TO
EAST. NAM AND GFS BOTH SHOWING DECENT ELEVATED CAPE BEHIND THE COLD
FRONT FROM PARCELS UP AROUND 750MB. IT LOOKS LIKE WE SHOULD REMAIN
CAPPED...HOWEVER STRONG LOW LEVEL LIFT GENERATED BY THE DEVELOPING
LOW PRESSURE AND THETAE ADVECTION MAY ATTEMPT TO BREAK THIS CAP. AND
WITH MOISTURE UP TO 750MB...NOT OUT OF THE QUESTION THAT THOSE
PARCELS GO AND WE GET A THUNDERSTORM. BEST CHANCE OF THIS APPEARS TO
BE ACROSS SOUTHWEST MINNESOTA BETWEEN 0Z AND 6Z...WHERE THE LIFT IS
STRONGEST AND MOISTURE DEEPEST. OTHER CONCERN IS ACROSS NORTHWEST
IOWA. WITH THE VERY WARM TEMPERATURES WILL LIKELY SEE CAPES AROUND
2000 J/KG THIS AFTERNOON. HOWEVER EXPECT THE STRONG MID LEVEL CAP TO
HOLD. IF WE GET HOTTER THAN FORECAST THE DEEPER MIXING SHOULD RESULT
IN LOWER DEWPOINTS...WITH THE NET RESULT OF BEING CAPPED STAYING THE
SAME. THIS IS SUPPORTED BY THE NAM AND HRRR.
SHORTWAVE RIDGING SHOULD PROVIDE A DRY DAY TUESDAY. OUR NEXT WEATHER
FEATURE IS A CUT OFF LOW ACROSS THE SOUTHERN PLAINS. NAM...GFS AND
ECMWF HAVE SIMILAR TRACKS OF THE UPPER LEVEL LOW ACROSS KANSAS. THIS
SHOULD PUT AT LEAST OUR SOUTHERN CWA IN DECENT QG FORCING LATE
TUESDAY NIGHT INTO WEDNESDAY. MODELS DIVERGE ON HOW THEY HANDLE
MOISTURE ADVECTION INTO THE AREA. WITH STRONGER SHORTWAVE RIDGING
AND HIGH PRESSURE TO THE NORTH...ECMWF AND SREF KEEP THE DEEPER
MOISTURE AND PRECIP TO OUR SOUTH...WHILE THE GFS AND NAM PUSH IT UP
TO INTERSTATE 90 ON WEDNESDAY. GIVEN MODEL UNCERTAINTY WILL BLEND
THE TWO SOLUTIONS...TRENDING A BIT CLOSER TO THE ECMWF AND SREF
SOLUTIONS.
THURSDAY AND MOST OF FRIDAY SHOULD REMAIN DRY WITH AN UPPER LEVEL
RIDGE OVERHEAD. ANOTHER SHORTWAVE WILL PUSH ACROSS LATER FRIDAY INTO
SATURDAY BRINGING OUR NEXT CHANCE OF SHOWERS AND POSSIBLY A
THUNDERSTORM.
HIGH TEMPERATURES TUESDAY THROUGH SUNDAY LOOK GENERALLY IN THE UPPER
50S TO LOWER 60S...WITH MODELS IN FAIRLY GOOD AGREEMENT WITH THESE
VALUES. LOW TEMPERATURES SHOULD BE IN THE UPPER 30S TO LOWER 40S.
DEPENDING ON WHAT EXACTLY HAPPENS WITH THE UPPER LOW ON
WEDNESDAY...TEMPERATURES MAY NEED TO BE ADJUSTED UP A FEW DEGREES IF
THE SOUTHERN SOLUTION PANS OUT...OR DOWN IF THE SHOWERS ARE MORE
WIDESPREAD. /CHENARD
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
ONCE AGAIN...STRATUS IS A CONCERN...AT LEAST THROUGH OUR NORTHERN
AND EASTERN ZONES. WIDESPREAD LIFR TO IFR CONDITIONS WILL BE FOUND
ALONG AND EAST OF AROUND A HURON SD...TO SIOUX FALLS...TO JUST EAST
OF SIOUX CITY LINE...AT LEAST THROUGH LATE MORNING. SOME OF THIS
STRATUS MAY LINGER RIGHT INTO EARLY AFTERNOON BEFORE MIXING OUT TO A
HIGHER LEVEL. DUE TO BREEZY WINDS...THE VISIBILITIES WILL NOT BE AS
BAD THIS MORNING AS IN PREVIOUS MORNINGS. BUT STILL MANY CEILINGS
WILL BE AT OR BELOW 500 FEET AGL. IT IS PROBLEMATIC WHETHER THE VERY
LOW CEILINGS WILL MAKE IT INTO THE KHON TAF. AS OF THIS TIME...
VARIOUS MODELS ARE HINTING AT SOME TEMPORARY STRATUS DEVELOPMENT AT
HURON A LITTLE LATER THIS MORNING...BUT A BIT HIGHER AT JUST INSIDE
THE MVFR CATEGORY. THIS WILL HAVE TO BE MONITORED CLOSELY. IN
ADDITION...ALL INDICATIONS ARE THAT THE STRATUS WILL NOT MAKE IT TO
KSUX. BUT WOULD NOT BE SURPRISED TO SEE A FEW SHREDS OF STRATUS IN
THE SCATTERED CATEGORY AFTER SUNRISE.
THE COLD FRONT WILL ADVANCE ACROSS OUR SD COUNTIES VERY SLOWLY
TODAY...AND SLOWED DOWN THE WIND SHIFT AT KFSD AND KSUX. SOME MVFR
CEILINGS MAY BE FOUND IN OUR WESTERN ZONES BEHIND THE FRONT ALL
AFTERNOON WITH LIGHT SHOWERS...WHICH WILL LIKELY IMPACT THE KHON
TAF. MVFR CEILINGS WILL PROBABLY THEN WORK THEIR WAY FROM WEST TO
EAST TONIGHT AND ENCOMPASS MOST OF THE FORECAST AREA IN DOING SO.
NORTHERLY WINDS WILL ALSO BE STRONG BEHIND THE FRONT...MAINLY ALONG
AND WEST OF THE JAMES RIVER VALLEY...AVERAGING 25 TO 35 KNOTS...WITH
SOME GUSTS OF 40 TO 45 KNOTS AS YOU APPROACH CENTRAL SD. THE WINDS
WILL DECREASE SOME TONIGHT. LASTLY...IT WILL BECOME QUITE WARM AGAIN
TODAY THROUGHOUT NORTHWEST IOWA. THIS HEATING MAY BE ENOUGH TO BREAK
CAPPING IN THOSE ZONES PRODUCING AN ISOLATED LATE AFTERNOON OR EARLY
EVENING THUNDERSTORM. /MJF
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...WIND ADVISORY FROM 10 AM TO 9 PM CDT MONDAY FOR SDZ038-039-
052>054-058>061-064>066-068-069.
WIND ADVISORY FROM 7 AM TO 9 PM CDT MONDAY FOR SDZ050-057-063.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
500 AM CDT MON APR 2 2012
.DISCUSSION.../ISSUED AT 500 AM CDT/
CURRENTLY SEEING A COLD FRONT PUSHING INTO OUR WESTERN CWA...HAVING
JUST PUSHED THROUGH CHAMBERLAIN...AND A WARM FRONT DRAPED FROM EAST
OF HURON SOUTH ACROSS SIOUX FALLS INTO NORTHWEST IOWA. EXPECTATION
IS THAT THIS WARM FRONT WILL CONTINUE TO SLOWLY DRIFT
SOUTHWEST...WITH THE AREA OF LOW STRATUS ACCOMPANYING IT. GUIDANCE
CONTINUES TO SLOW DOWN THE PROGRESSION OF THE COLD FRONT. MODELS
COMING INTO AGREEMENT THAT IT WILL WILL SLOWLY PUSH EAST THROUGH THE
DAY...NOT PASSING THROUGH SIOUX FALLS UNTIL 20-22Z...AND THE EASTERN
EDGE OF THE CWA 2-4Z. THIS WILL IMPACT TODAYS TEMPERATURE AND WIND
POTENTIAL.
TEMPERATURES ARE A BIG QUESTION MARK WITH A LARGE SPREAD IN THE
GUIDANCE TODAY. WITH THE SLOWER ARRIVAL OF THE COLD FRONT...RAISED
TEMPERATURES SEVERAL DEGREES IN THE WEST. MEANWHILE...FROM SIOUX
FALLS TO SIOUX CITY AND POINTS EAST...TEMPERATURES DEPEND ON
PROGRESSION OF THE WARM FRONT AND ATTENDANT LOW CLOUDS. THE HRRR HAS
PERFORMED FAIRLY WELL THE PAST COUPLE DAYS WITH THE EVOLUTION OF
THE WARM FRONT AND CLOUDS. IT LIFTS THE FRONT NORTH ALMOST THROUGH
THE ENTIRE CWA...RESULTING IN HIGHS IN THE 80S FROM YANKTON TO SIOUX
FALLS AND POINTS EAST...WITH NEAR 90 ONCE AGAIN IN SIOUX CITY. THIS
IS THE WARMEST MODEL SOLUTION...BUT THE NAM AND ECMWF ARE ONLY A FEW
DEGREES COOLER. THE LOW LEVEL MOISTURE AND STRATUS WILL BE A BIT
DEEPER THIS MORNING COMPARED TO LAST...SO THINK IT MAY TAKE A BIT
LONGER FOR CLOUDS TO ERODE. BUT GIVEN WHAT HAS HAPPENED THE PAST FEW
DAYS...THE SLOWER COLD FRONT...AND MODEL AGREEMENT...CURRENT
THINKING IS THAT THEY DO INDEED ERODE...ALLOWING FOR ANOTHER VERY
WARM DAY WITH HIGHS IN THE UPPER 70S TO MID 80S ACROSS EXTREME
SOUTHEAST SOUTH DAKOTA AND NORTHWEST IOWA. GIVEN UNCERTAINTY...DID
NOT GO QUITE AS WARM AS WARMEST SOLUTIONS...BUT WOULD NOT BE
SURPRISED IF TEMPS END UP A FEW DEGREES WARMER THAN CURRENT
FORECAST. ON THE OTHER HAND...IF THE LOW CLOUDS STAY LOCKED IN
TEMPERATURES WILL BE MUCH COOLER THAN FORECAST...ALTHOUGH SEE THIS
AS A LOWER PROBABILITY EVENT AT THIS TIME.
NEXT UP IS THE WINDS. WINDS WILL BECOME STRONG BEHIND THE COLD
FRONT. 900MB WINDS ARE EXPECTED TO BE IN THE 30 TO 40 KTS RANGE. THE
COMBINATION OF DECENT LOW LEVEL CAA AND PRESSURE RISES WILL HELP
PROMOTE MIXING AND THE TRANSFER OF THESE WINDS TO THE SURFACE. A
BORDERLINE WIND ADVISORY EVENT...BUT WILL KEEP THE CURRENT ADVISORY
MAINLY AS IS...WITH SUSTAINED WINDS APPROACHING 30 MPH FOR A PERIOD
IN THE WEST...WITH A FEW GUSTS AROUND 40 MPH. DID CUT ONE ROW OF
COUNTIES OFF THE ADVISORY GIVEN THE SLOWER MOVEMENT OF THE FRONT AND
A SLIGHTLY WEAKER CORE OF LOW LEVEL WINDS.
PRECIP CHANCES LOOK TO BE CLOSE TO ZERO OUT AHEAD OF THE FRONT. SOME
ELEVATED CAPE IN OUR FAR NORTHWEST...BUT A STRONG CAPPING INVERSION
AROUND 750MB WILL PREVENT ANY ELEVATED CONVECTION. DEEP LOW LEVEL
MOISTURE BEHIND THE FRONT WILL ALLOW FOR DRIZZLE AND LIGHT
SHOWERS...MAINLY NORTH OF INTERSTATE 90 AND WEST OF INTERSTATE 29.
EXPECT THIS AREA OF DRIZZLE TO BEGIN TO DISSIPATE TONIGHT AS THE
MOISTURE LAYER BECOMES SHALLOW AND BEGINS TO ERODE AWAY FROM WEST TO
EAST. NAM AND GFS BOTH SHOWING DECENT ELEVATED CAPE BEHIND THE COLD
FRONT FROM PARCELS UP AROUND 750MB. IT LOOKS LIKE WE SHOULD REMAIN
CAPPED...HOWEVER STRONG LOW LEVEL LIFT GENERATED BY THE DEVELOPING
LOW PRESSURE AND THETAE ADVECTION MAY ATTEMPT TO BREAK THIS CAP. AND
WITH MOISTURE UP TO 750MB...NOT OUT OF THE QUESTION THAT THOSE
PARCELS GO AND WE GET A THUNDERSTORM. BEST CHANCE OF THIS APPEARS TO
BE ACROSS SOUTHWEST MINNESOTA BETWEEN 0Z AND 6Z...WHERE THE LIFT IS
STRONGEST AND MOISTURE DEEPEST. OTHER CONCERN IS ACROSS NORTHWEST
IOWA. WITH THE VERY WARM TEMPERATURES WILL LIKELY SEE CAPES AROUND
2000 J/KG THIS AFTERNOON. HOWEVER EXPECT THE STRONG MID LEVEL CAP TO
HOLD. IF WE GET HOTTER THAN FORECAST THE DEEPER MIXING SHOULD RESULT
IN LOWER DEWPOINTS...WITH THE NET RESULT OF BEING CAPPED STAYING THE
SAME. THIS IS SUPPORTED BY THE NAM AND HRRR.
SHORTWAVE RIDGING SHOULD PROVIDE A DRY DAY TUESDAY. OUR NEXT WEATHER
FEATURE IS A CUT OFF LOW ACROSS THE SOUTHERN PLAINS. NAM...GFS AND
ECMWF HAVE SIMILAR TRACKS OF THE UPPER LEVEL LOW ACROSS KANSAS. THIS
SHOULD PUT AT LEAST OUR SOUTHERN CWA IN DECENT QG FORCING LATE
TUESDAY NIGHT INTO WEDNESDAY. MODELS DIVERGE ON HOW THEY HANDLE
MOISTURE ADVECTION INTO THE AREA. WITH STRONGER SHORTWAVE RIDGING
AND HIGH PRESSURE TO THE NORTH...ECMWF AND SREF KEEP THE DEEPER
MOISTURE AND PRECIP TO OUR SOUTH...WHILE THE GFS AND NAM PUSH IT UP
TO INTERSTATE 90 ON WEDNESDAY. GIVEN MODEL UNCERTAINTY WILL BLEND
THE TWO SOLUTIONS...TRENDING A BIT CLOSER TO THE ECMWF AND SREF
SOLUTIONS.
THURSDAY AND MOST OF FRIDAY SHOULD REMAIN DRY WITH AN UPPER LEVEL
RIDGE OVERHEAD. ANOTHER SHORTWAVE WILL PUSH ACROSS LATER FRIDAY INTO
SATURDAY BRINGING OUR NEXT CHANCE OF SHOWERS AND POSSIBLY A
THUNDERSTORM.
HIGH TEMPERATURES TUESDAY THROUGH SUNDAY LOOK GENERALLY IN THE UPPER
50S TO LOWER 60S...WITH MODELS IN FAIRLY GOOD AGREEMENT WITH THESE
VALUES. LOW TEMPERATURES SHOULD BE IN THE UPPER 30S TO LOWER 40S.
DEPENDING ON WHAT EXACTLY HAPPENS WITH THE UPPER LOW ON
WEDNESDAY...TEMPERATURES MAY NEED TO BE ADJUSTED UP A FEW DEGREES IF
THE SOUTHERN SOLUTION PANS OUT...OR DOWN IF THE SHOWERS ARE MORE
WIDESPREAD. /CHENARD
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
EXPECT REDEVELOPMENT OF STRATUS/FOG OVER NORTHEAST HALF OF THE AREA
THROUGH THE REMAINDER OF TONIGHT/EARLY MONDAY. POTENTIAL FOR LIFR
VISIBILITY...ESPECIALLY IN HIGHER ELEVATIONS ACROSS SOUTHWEST MN AS
STRATUS CURRENTLY DEVELOPING ACROSS NORTHERN IOWA ADVECTS INTO OUR
FORECAST AREA ON PERSISTENT EAST-SOUTHEAST LOW LEVEL FLOW. THESE
IFR-LIFR CONDITIONS EXPECTED TO ADVECT WESTWARD THROUGH INTERSTATE
29 CORRIDOR AFTER 09Z-10Z...WITH IFR-LIFR CONDITIONS PERSISTING
THROUGH 14Z-15Z. WHILE VISIBILITY EXPECTED TO IMPROVE THEREAFTER...
CONTINUED EAST-SOUTHEAST FLOW WILL LIKELY LOCK STRATUS IN PLACE INTO
THE EARLY-MID AFTERNOON.
LATEST MODELS SLOWER WITH EASTWARD PUSH OF COLD FRONT...WHICH WILL
BE NEEDED TO COMPLETELY SCOUR OUT THE LOW LEVEL MOISTURE. BEHIND THE
FRONT...WESTERN AREAS WILL SEE INCREASING NORTHERLY WINDS BEGIN TO
GUST OVER 25KTS BY 14Z-16Z...WITH SCATTERED LIGHT SHOWERS ALONG WITH
BROKEN MVFR CEILINGS MORE LIKELY IN POST-FRONTAL AIRMASS THAN AHEAD
OF THE BOUNDARY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...WIND ADVISORY FROM 10 AM TO 9 PM CDT MONDAY FOR SDZ038-039-
052>054-058>061-064>066-068-069.
WIND ADVISORY FROM 7 AM TO 9 PM CDT MONDAY FOR SDZ050-057-063.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
635 AM CDT MON APR 2 2012
.AVIATION...
AN MCS PROPAGATING UP THE COASTAL PLAIN FROM MATAGORDA BAY WILL
LIKELY AFFECT THE AIRPORTS FROM KCXO SOUTH TO THE COAST THIS
MORNING THROUGH 15Z. GIVEN THE UNSTABLE AIR MASS AND THE LOCATION
OF THE STRONGEST WINDS AT 1130Z...INDICATED WIND GUSTS TO 35 KNOTS
POSSIBLE FOR KLBX AND KGLS. HOWEVER...MAY NEED TO ADJUST THESE
FURTHER INLAND.
THE MODEL FORECASTS DIFFERED FOR TODAY. THE 4 KM NCEP WRF
INITIALIZED AND HAS HANDLED THE MCS WELL THIS MORNING. COMBINED
THE WRF AND RUC FOR THE THUNDERSTORM FORECAST FOR TODAY. OUTSIDE
OF STORMS...VFR IS EXPECTED THIS AFTERNOON ALONG WITH BREEZY
WINDS.
MVFR IS EXPECTED TO DEVELOP BY AROUND 06Z INLAND AND AFTER 03Z
TOWARD AND ALONG THE COAST. IFR IS POSSIBLE MAINLY OVERNIGHT
TONIGHT...ESPECIALLY IF A GIVEN LOCATION RECEIVES RAINFALL TODAY.
40
&&
.PREV DISCUSSION... /ISSUED 408 AM CDT MON APR 2 2012/
DISCUSSION...
A WEAK UPPER LEVEL CIRCULATION WAS SPINNING NORTH OF MATAGORDA BAY
THIS MORNING. THIS FEATURE WILL SLOWLY MOVE NORTH NORTHEAST INTO
NORTHWEST LOUISIANA BY EVENING. ANOTHER UPPER LEVEL DISTURBANCE
OVER SOUTH TEXAS IS TRIGGERING SHOWERS AND THUNDERSTORMS OVER
SOUTH TEXAS AND THE MIDDLE TEXAS COAST. THIS DISTURBANCE IS MOVING
EAST AND THE ASSOCIATED PRECIP SHOULD BEGIN TO MOVE OVER PARTS OF
THE CWA BY 5 AM. MODELS ARE NOT DOING A GREAT JOB WITH THE SMALL
SCALE DETAILS AND SHORT TERM GUIDANCE HAS INITIALIZED POORLY. THAT
SAID...FEEL THE DEEPER MOISTURE WILL REMAIN EAST OF THE UPPER
CIRCULATION NORTH OF MATAGORDA BAY. BEST RAIN CHANCES SHOULD LIE
TO THE EAST OF THE I-45 CORRIDOR AND SOUTH OF HWY 105. THE SYSTEM
WILL STRENGTHEN THIS AFTERNOON AND HEAVIER RAIN WILL BEGIN TO
DEVELOP AND HEAD TOWARD LOUISIANA. IF THE SYSTEM TRACKS FURTHER
WEST THAN CURRENTLY FCST...SOME OF THE MORE ORGANIZED HEAVIER RAIN
WILL ALSO SHIFT WEST AND INTO HOUSTON.
LOOKING SOUTH...THE LINE OF STORMS OVER SOUTH TEXAS IS MAKING
STEADY PROGRESS EAST THIS MORNING. SHORT TERM GUIDANCE IS WELL
BEHIND THE CURVE WITH THE PLACEMENT OF THE PRECIP. THE 06Z RUC IS
BEGINNING TO CATCH ON AND IT BRINGS A WEAK LINE OF SHOWERS INTO
THE REGION...WEST OF I-45 BY 15Z. THE 4KM WRF SEEMS TO BE DOING A
GOOD JOB WITH THIS AREA OF CONVECTION (COMPLETELY MISSED THE
PRECIP OVER LOUISIANA). THE WRF BRINGS THIS LINE OF STORMS
INTO AND ACROSS SOUTHEAST TEXAS THIS MORNING...EXITING THE THE
REGION BY 19Z. WILL HEDGE MY BETS AND GO WITH CHANCE POPS SOUTH
AND SLIGHT CHANCE NORTH. WILL WATCH TRENDS AND POPS MAY BE NUDGED
UPWARD LATER THIS MORNING IF TRENDS WARRANT. SPC HAS OUTLOOKED THE
EXTREME NORTHERN PORTION OF SE TX IN SLIGHT RISK FOR THIS
AFTERNOON AND EVENING. FCST SOUNDINGS SHOW A GREAT DEAL OF
INSTABILITY (CAPE ABOVE 3000 AND LI`S AROUND -10)...BUT THERE IS
STILL SOME WEAK CAPPING TO OVERCOME. THE PROBABILITY OF OCCURRENCE
SHOULD REMAIN SLIGHT BUT THERE IS SOME POTENTIAL FOR STORMS TO
PRODUCE DAMAGING WINDS AND LARGE HAIL. THE THREAT AREA IS NORTH OF
A BRENHAM TO HUNTSVILLE TO CLEVELAND LINE.
THERE SHOULD BE A BREAK IN THE PRECIP TONIGHT AS THE MORNING
SYSTEM IS EAST OF THE REGION AND THE NEXT STRONG UPPER LEVEL
SYSTEM IS STILL OVER NEW MEXICO. THE UPPER LEVEL LOW OUT WEST WILL
MOVE NORTHEAST ON TUESDAY. NAM AND GFS DIFFER WITH MOISTURE
PROFILES BUT CAPPING IS WEAK AND UPPER LEVEL WINDS BECOME
INCREASINGLY DIVERGENT. WILL GO WITH HIGH END CHANCE POPS FOR
TUESDAY/TUES NIGHT. NOT SURE WHEN THINGS WILL CLEAR. THE
ECMWF...NAM AND CANADIAN HOLD ONTO THE PRECIP THROUGH WEDNESDAY
MORNING WHILE THE GFS CLEARS THINGS OUT RATHER QUICKLY. PREFER THE
SLOWER CLEARING SINCE THE DRY LINE/WEAK FRONT NEVER REALLY CLEARS
THE COAST. THE UPPER LEVEL LOW WILL BE EAST OF THE REGION ON
THURSDAY AND AN UPPER LEVEL RIDGE WILL BEGIN TO AMPLIFY OVER THE
SOUTHERN PLAINS. PRECIP SHOULD REMAIN NORTH AND WEST OF THE REGION
THURSDAY THROUGH SATURDAY WITH ANOTHER WARM UP UNDERWAY. MAX TEMPS
TOWARD THE END OF THE WEEK WILL BE BACK INTO THE MID/UPPER 80S. 43
MARINE...
AS AN UPPER LOW MOVES ACROSS THE INLAND AREAS...THUNDERSTORMS WILL
BE POSSIBLE TODAY OVER THE BAYS AND COASTAL WATERS. ALTHOUGH THE
FORECAST MODELS DIFFERED...THERE WAS ENOUGH SIMILARITIES TO SUGGEST
MODERATE ONSHORE WINDS WILL AFFECT THE MARINE AREAS TODAY THROUGH
TUESDAY. A COLD FRONT SHOULD APPROACH THE COAST FROM THE NORTHWEST
LATE TUESDAY AND EARLY WEDNESDAY MORNING. FOR NOW IT APPEARS THAT
THE FRONT MAY WELL STAY INLAND OR MOVE JUST OFFSHORE BEFORE
RETURNING BACK TO THE NORTH LATE WEDNESDAY AND THURSDAY. AM
EXPECTING ONSHORE WINDS TO THEN RETURN AND PERSIST THROUGH THE END
OF THE WEEK.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 83 70 80 64 82 / 30 20 50 50 10
HOUSTON (IAH) 84 71 83 67 85 / 30 20 50 50 20
GALVESTON (GLS) 81 73 81 71 81 / 40 20 50 50 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
642 AM CDT MON APR 2 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
330 AM CDT MON APR 2 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES THROUGH TUESDAY
AND TEMPERATURES.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ALONG THE WEST COAST OF THE U.S....
TROUGHING SPLITTING INTO TWO FROM WESTERN MONTANA INTO ARIZONA...AND
STRONG RIDGING ACROSS THE ENTIRE MISSISSIPPI RIVER VALLEY NORTH INTO
WESTERN HUDSON BAY. STRONG WARM ADVECTION PATTERN TAKING PLACE UNDER
THE UPPER RIDGE WITH SOUTHWEST 850MB WINDS OF 30-60 KT FROM KANSAS
INTO SOUTHERN MINNESOTA PER PROFILER/VWP DATA. 00Z SOUNDINGS AT MPX
AND ABR SAW THEIR 850MB TEMPS RISE 3C COMPARED TO THEIR PREVIOUS 12Z
ONES...NOW AT 15C AND 20C RESPECTIVELY. TIGHT THERMAL GRADIENT
REMAINS...THOUGH...WITH GRB AND INL REPORTING AROUND 5C AND APX AT
-1C AT 00Z. THE WARM ADVECTION ALOFT PLUS PLENTY OF DRY AIR SEEN ON
THE 00Z MPX AND OAX SOUNDINGS HAS KEPT THE ATMOSPHERE CAPPED TO
CONVECTION. NEAREST CONVECTION IS NEAR DULUTH INTO FAR NORTHERN
WISCONSIN...ON THE NOSE OF THAT 850MB JET. BELOW THE WARM ADVECTION
SEEN AT 850MB...A COOL/DRY LOW LEVEL EASTERLY FLOW CONTINUES...
BETWEEN HIGH PRESSURE SITUATED OVER NORTHEAST ONTARIO AND A SURFACE
WARM FRONT THAT STRETCHES FROM NEAR ABERDEEN SD TO JUST SOUTH OF DES
MOINES IA AND ST LOUIS MO. AN AREA OF STRATUS LEFTOVER FROM
YESTERDAY AFTERNOON IN NORTHERN ILLINOIS HAS ADVECTED ON
EAST-SOUTHEAST WINDS...NOW ENCOMPASSING SOUTHWEST MINNESOTA INTO
NORTH CENTRAL IOWA. TEMPERATURES SO FAR HAVE FALLEN INTO THE MID 40S
TO MID 50S. SOUTH AND WEST OF THE AFOREMENTIONED WARM FRONT...
READINGS ARE IN THE MID TO UPPER 60S.
TODAY AND TONIGHT...WHAT LOOKED LIKE IN PREVIOUS DAYS OF 500MB
HEIGHTS FALLING THROUGHOUT THIS PERIOD NOW IS COMPLETELY REVERSED.
ALL MODELS NOW SHOW THE CURRENT UPPER RIDGE BUILDING OVER THE
FORECAST AREA TODAY AND EVEN INTO THIS EVENING. A LOT OF THIS HAS TO
DO WITH THE WESTERN TROUGH...WHICH IS SPLITTING APART EARLIER AND
THE NORTHERN PORTION ONLY ENDS UP REACHING NORTHWEST MINNESOTA BY
12Z TUESDAY. THE CHANGE SYNOPTICALLY HAS A BIG IMPACT ON THE
FORECAST. FIRST...NOW THAT THE AREA IS UNDERNEATH BUILDING HEIGHTS
AT 500MB INDUCING SUBSIDENCE...A DRIER FORECAST IS ON TAP. HAVE
REMOVED ALL PRECIPITATION CHANCES FOR TODAY AND LOWERED THEM DOWN TO
AT MOST 20 FOR THIS EVENING. THE 02.00Z GFS IS BASICALLY THE ONLY
MODEL THAT SHOWS PRECIPITATION TODAY...WHICH IS A RESULT OF DRIZZLE
BELOW A CAP. THIS SEEMS VERY SUSPECT AND THE GFS HAS BEEN KNOWN TO
OVERDO THESE DRIZZLE SCENARIOS AS SEEN BACK DURING THE UNPRECEDENTED
WARM SPELL IN MARCH. RUC/NAM SOUNDINGS LOOK MORE REPRESENTATIVE.
THERE STILL ARE INDICATIONS FOR PRECIPITATION AFTER 06Z TONIGHT...
ESPECIALLY NORTH OF I-90 WHERE ISENTROPIC LIFT SEEN ON THE 305K
SURFACE CAN INITIATE CONVECTION. NOTE...THOUGH...THE 02.00Z GEM AND
01.12Z ECMWF INITIATE THIS CONVECTION EVEN FARTHER NORTH OVER
NORTHERN WISCONSIN. SINCE THE 02.00Z ECMWF LOOKS MORE LIKE THE
NAM/GFS VERSUS ITS PREVIOUS RUN...HAVE LEFT THE PREVIOUS FORECAST
CHANCES ALONE AFTER 06Z. IF CONVECTION GOES TONIGHT...1-6 KM SHEAR
IS MOSTLY LESS THAN 15 KTS. THEREFORE...ANTICIPATING IT TO BE
DISORGANIZED AND NOT PRESENT MUCH OF A SEVERE THREAT. TEMPERATURES
ARE ANOTHER PROBLEM. HUDSON BAY HIGH PRESSURE LOOKS TO REMAIN
ANCHORED NOW TODAY...CAUSED IN PART BY THE BUILDING UPPER
RIDGING...WHICH HELPS TO MAINTAIN A FEED OF LOWER LEVEL COLD AIR SUB
850MB. FOR THE MOST PART EXPECTING HIGHS TODAY SIMILAR TO THOSE OF
YESTERDAY...THOUGH COLD ADVECTION OCCURRING AT 925MB TOWARDS CENTRAL
WISCONSIN COULD RESULT IN HIGHS A FEW DEGREES COLDER THERE. WITH A
SLOWER PROGRESSION OF THE UPPER RIDGE...AS WELL WITH AN INVERTED
SURFACE TROUGH MOVING WEST TO EAST ACROSS MINNESOTA...HAVE RAISED
LOWS UP DRAMATICALLY WEST OF THE MISSISSIPPI RIVER.
TUESDAY AND TUESDAY NIGHT...THE CHANGES KEEP COMING. MAJORITY OF THE
ENERGY WITH THE NORTHERN PORTION OF THE WESTERN TROUGH LOOKS TO LIFT
INTO NORTHEAST ONTARIO. HOWEVER...A SHORTWAVE EXTENDING
SOUTHWESTWARD IS PROGGED TO MOVE INTO NORTHERN WISCONSIN BY 00Z
WEDNESDAY...THEN DROP SOUTHEAST THROUGH THE AREA TUESDAY NIGHT. THIS
SHORTWAVE IS IMPORTANT AS THERE APPEARS TO BE AN AREA OF LOW TO
MID-LEVEL STRATUS AHEAD OF IT. ONCE THE SHORTWAVE PASSES THEN SKIES
CAN CLEAR OUT. HAVE HAD TO INCREASE CLOUD COVER FOR TUESDAY TO
ACCOUNT FOR THE STRATUS...WHICH IN COMBINATION WITH LOW LEVEL COLD
ADVECTION HAS RESULTED IN LOWERING HIGHS FOR SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN A FEW DEGREES. ON THE OTHER HAND...THE
SLOWER PROGRESSION NOTED IN THE TODAY/TONIGHT DISCUSSION WITH THE
INVERTED TROUGH WILL ALLOW FAR SOUTHWEST WISCONSIN TO WARM UP MORE.
WOULD NOT BE SURPRISED IF TEMPERATURES MAY TRY TO FALL IN THE WAKE
OF THAT INVERTED TROUGH. REGARDING PRECIPITATION CHANCES ON
TUESDAY...FORCING IS VERY WEAK GIVEN LIMITED 500MB HEIGHT FALLS AND
FRONTOGENESIS BEHIND THE PASSING INVERTED TROUGH WEAKENING. IN
FACT...THE 02.00Z NAM/CANADIAN BOTH SUGGEST DRY. THEREFORE...CHANCES
ON TUESDAY ARE ONLY 20 PERCENT...AND CONFINED TO THE MORNING. LOWS
TUESDAY NIGHT ARE KIND OF TRICKY. THE 02.00Z NAM SUGGESTS THE LOW TO
MID LEVEL STRATUS REALLY DOES NOT CLEAR OUT...PARTICULARLY ALONG AND
SOUTH OF I-90. HOWEVER..THE 02.00Z GFS/CANADIAN/ECMWF ARE ALL
CLEARING SKIES OUT. HAVE CONSIDERED THE NAM AN OUTLIER FOR NOW AND
HAVE KEPT THE PREVIOUS FORECAST AND MAJORITY CONSENSUS OF CLEARING
SKIES. ANOTHER PROBLEM IS THAT THE EAST WINDS LOOK A LITTLE STRONGER
BECAUSE OF THE HIGH PRESSURE AREA BUILDING IN ONLY REACHING NORTHERN
MINNESOTA. IN THE END...KEPT LOWS PRETTY CLOSE TO THE PREVIOUS
FORECAST. LOOKS LIKE POTENTIAL EXISTS FOR FREEZE CONDITIONS NORTH OF
I-94. NO FROST ANTICIPATED...THOUGH...GIVEN DEWPOINTS EXPECTED TO
FALL INTO THE 20S AND WINDS STAYING UP.
WEDNESDAY AND WEDNESDAY NIGHT...A COUPLE OF BATTLING FEATURES ARE
FORECAST DURING THIS PERIOD. THE SOUTHERN END OF THE CURRENT WESTERN
TROUGH IS PROGGED TO CLOSE OFF INTO AN UPPER LOW...THEN LIFT THROUGH
KANSAS AND MISSOURI DURING THIS PERIOD. MEANWHILE...WE HAVE THAT
HIGH PRESSURE AREA BUILDING IN FROM NORTHWEST MINNESOTA...WHICH ENDS
UP CONSOLIDATING WITH A CANADIAN HIGH DROPPING DOWN INTO NORTHERN
ONTARIO. DRY AIR ASSOCIATED WITH THIS SURFACE HIGH PLUS UPPER
RIDGING NORTH AND NORTHEAST OF THE UPPER LOW SHOULD BE SUFFICIENT TO
HOLD OFF ANY PRECIPITATION FROM COMING INTO THE FORECAST AREA. COULD
SEE A FEW MID/HIGH CLOUDS TRY TO APPROACH NORTHEAST IOWA...BUT
ANTICIPATING MOST CLOUDS TO STAY SOUTH OF THE AREA TOO. WITH PLENTY
OF SUN AND 850MB TEMPS OF 2-4C...SHOULD SEE TEMPERATURES CLIMB INTO
THE LOW 60S. BETTER 925-850MB COOLING COMES IN WEDNESDAY NIGHT ON
EASTERLY WINDS...LIKELY WITH THAT CANADIAN HIGH COMING DOWN. A
SUSTAINED 5 TO 10 MPH WIND LOOKS LIKELY WEDNESDAY NIGHT...WHICH
SHOULD HELP TEMPERATURES FROM PLUMMETING TOO MUCH. STILL...READINGS
IN THE 30S ARE EXPECTED...COOLEST IN CENTRAL WISCONSIN CLOSER TO THE
COLD ADVECTION.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
330 AM CDT MON APR 2 2012
FOCUS OF THE LONG TERM FORECAST IS ON DEEP TROUGHING THAT IS ALONG
THE WEST COAST THURSDAY MORNING. UPPER RIDGING DOWNSTREAM OF THE
TROUGH SHOULD STAY NEAR OR OVER THE FORECAST AREA THROUGH FRIDAY
EVENING...MAINTAINING DRY CONDITIONS. THURSDAY INTO THURSDAY NIGHT
WILL LIKELY BE THE COOLEST PERIOD AS THE CANADIAN HIGH SLIDES DOWN
INTO EASTERN WISCONSIN ON THE EAST SIDE OF THE UPPER RIDGE. IF THERE
IS GOING TO BE A WIDESPREAD FREEZE...THINKING THURSDAY NIGHT WILL BE
THE BEST SHOT. WISCONSIN AREAS LOOK MOST SUSCEPTIBLE BEING CLOSER TO
THE SURFACE HIGH. WARMING THEN OCCURS FOR FRIDAY INTO SATURDAY AS
THE SURFACE HIGH DEPARTS OFF TO THE EAST. REGARDING THE UPPER
TROUGH...02.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES ARE ALL IN
FAIRLY GOOD AGREEMENT EJECTING IT OUT INTO THE NORTHERN PLAINS ON
SATURDAY. THE MODELS THEN BEGIN TO DIFFER ON SPEED FROM THERE...
RESULTING IN LOWERED CONFIDENCE. IN ANY EVENT...IT APPEARS THE
TROUGH HAS SLOWED DOWN ENOUGH THAT ANY FORCING FOR PRECIPITATION
WILL STAY WEST OF THE FORECAST AREA FRIDAY NIGHT. MODEL CONSENSUS
SUGGESTS THAT A WARM CONVEYOR BELT AHEAD OF THE NORTHERN PLAINS
TROUGH WILL ENTER THE AREA SATURDAY. MEAGER INSTABILITY EXISTS...
JUST ENOUGH TO WARRANT A CHANCE OF THUNDERSTORMS. AFTER
SATURDAY...STAYED WITH THE MODEL CONSENSUS IDEA WHICH WOULD BE FOR A
DRYING TREND. THIS IS DUE TO THE COLD FRONT ASSOCIATED WITH THE
TROUGH MOVING THROUGH THE FORECAST AREA. AGAIN...LOW CONFIDENCE
HERE.
&&
.AVIATION...TODAY AND TONIGHT
641 AM CDT MON APR 2 2012
MVFR CONDITIONS CAN BE EXPECTED AT KRST EARLY THIS MORNING AS A
STRATUS DECK JUST BRUSHES THE TAF SITE PRODUCING CEILINGS AROUND 2
KFT. CONDITIONS SHOULD QUICKLY IMPROVE TO VFR BY MID MORNING. VFR
CONDITIONS ARE EXPECTED AT KLSE THROUGH THE AFTERNOON HOURS. A MID
LEVEL CLOUD DECK WILL PRODUCE CEILINGS AROUND 6 KFT AT KLSE
THROUGH 14Z...THEN SCATTERED OUT DURING THE MID TO LATE MORNING
HOURS. SOUTHEAST WINDS OF 13 TO 20 KTS WILL PERSIST THROUGH THE
DAY TODAY. WIND GUSTS UP TO 30 KTS ARE POSSIBLE ESPECIALLY AT
KRST. A WARM FRONT CURRENTLY POSITIONED ACROSS CENTRAL IOWA...WILL
LIFT NORTHWARD INTO NORTHERN IOWA/SOUTHERN WISCONSIN AS SURFACE
LOW PRESSURE MOVES INTO NORTHEAST IOWA THIS AFTERNOON. LOW LEVEL
MOISTURE WILL BE PUMPED NORTHWARD INTO THE REGION THIS EVENING
INTO THE OVERNIGHT HOURS...LEADING TO THE DEVELOPMENT OF SHOWERS
AND THUNDERSTORMS. PLAN ON CEILINGS LOWERING INTO THE 3 TO 4 KFT
RANGE THIS EVENING AS THE WARM FRONT MOVES IN. FORECAST MODELS
SHOWING SOME DIFFERENCES ON EXACTLY WHERE THE SHOWERS AND
THUNDERSTORMS WILL DEVELOP. THERE ARE SIGNALS THAT THE ACTIVITY
COULD DEVELOP ALONG THE INTERSTATE 90 CORRIDOR...WHILE THERE ARE
OTHERS THAT SUGGEST THE THUNDERSTORMS COULD DEVELOP ACROSS
NORTHERN WISCONSIN. GIVEN THE UNCERTAINTY ON TIMING AND LOCATION
OF THE THUNDERSTORMS DECIDED TO INCLUDE CB MENTION IN THE
TAF...STARTING AT 08Z AT KRST AND 10Z AT KRST...WITH A FORECAST
MODEL CONSENSUS OF THE THUNDERSTORMS FIRING AFTER 06Z. CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL PERSIST THROUGH 12 Z...BEFORE A
COLD FRONT MOVES THROUGH WITH WINDS SHIFTING TO THE NORTH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CDT MON APR 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....WETENKAMP
AREA FORECAST DISCUSSION
NWS PUEBLO CO
400 PM MDT MON APR 2 2012
.SHORT TERM...
(TONIGHT AND TUESDAY)
...STRONG SPRING STORM TAKING AIM ON SOUTH CENTRAL AND SOUTHEAST
COLORADO...
MODELS IN REMARKABLE AGREEMENT WITH THE OVERALL DETAILS OF CLOSED
UPPER LOW ACROSS EAST CENTRAL NEW MEXICO SHIFTING EASTWARD THEN
NORTHEASTWARD INTO THE TX/OK PANHANDLE BY TUES AFTERNOON. FRONT HAS
ALREADY SLAMMED THROUGH EASTERN CO EARLIER TODAY...WITH PEAK GUSTS
IN EXCESS OF 60 MPH ACROSS PORTIONS OF EL PASO COUNTY. HRRR AND
LOCAL 4 KM WRF INDICATED TWO PERIODS OF STRONGER WINDS...ONE THIS
MORNING...AND ANOTHER THIS AFTERNOON INTO EARLY THIS EVENING. JUST
PICKED UP A GUST TO 50 KTS AT KPUB AIRPORT AROUND 230 PM...SO
PERHAPS THE SHORT RANGE MODELS DO HAVE A HANDLE ON THIS.
THUS...WILL MAINTAIN HIGH WIND WARNINGS THROUGH 03Z.
INTERESTINGLY...HRRR SUGGESTS CORE OF STRONGER WINDS MAY EXPAND
ACROSS MORE OF THE SOUTHEAST PLAINS AND CONTINUE THROUGH
06Z...HOWEVER WITH TIGHTEST PRESSURE GRADIENT ALREADY PAST...WILL
LEAVE CURRENT EXPIRATION AT 03Z AND LET LATER SHIFTS MONITOR THE
TRENDS TO DECIDE IF EXTENSION IN TIME...OR EXPANSION IN AREA IS
NECESSARY. LOCAL 4 KM WRF BACKED OFF SOME ON WIND GUSTS AFTER 03Z
FOR ALL BUT PERHAPS EASTERN EL PASO COUNTY. OTHER AREA OF CONCERN
FOR HIGH WINDS CONTINUES ALONG THE EASTERN SIDE OF THE SAN LUIS
VALLEY AS WINDS ACCELERATE THROUGH THE PASSES IN THE SANGRES AND
SPILLS INTO THE VALLEY. HRRR AND 12Z 4KM WRF STILL PAINT THIS
SCENARIO IN THE LATEST RUNS...WITH PEAK WINDS OCCURRING NOW THROUGH
00Z...WITH GUSTS STARTING TO TAIL OFF BY 03Z. ALS HAD A WIND GUST
TO 54 MPH AFTER NOON...WHICH IS VERY CLOSE. SUSPECT LOCAL AREAS TO
THE WEST HAD HIGHER GUSTS. AGAIN...WRF KEEPS GUSTS UP AROUND 70 MPH
THROUGH 03Z BEFORE TAILING OFF...SO CURRENT HIGHLIGHT LOOKS ON
TARGET.
FIRST LOBE OF ENERGY WILL ROTATE AROUND THE CLOSED LOW INTO
SOUTHEAST COLORADO THIS EVENING. SNOW IS ALREADY OCCURRING ACROSS
THE EAST FACING SLOPES OF THE SANGRES/WETS...THOUGH ITS BEEN PRETTY
LIGHT SO FAR AS MOISTURE LAYER REMAINS SHALLOW. HOWEVER...RADARS TO
THE SOUTH SHOW ECHOES EXPANDING ACROSS NORTHEAST NM WITH SOME
EMBEDDED CONVECTION EVIDENT VIA LIGHTNING STRIKES. SHOULD SEE THIS
BAND OF SHOWERS SPREAD NORTHWARD THROUGH THE EVENING WITH SNOW
SPREADING NORTHWARD AND RAMPING UP ACROSS THE PIKES PEAK AREA AFTER
03-06Z. NICE ISENTROPIC UPGLIDE EVIDENT IN BOTH NAM AND GFS ON THE
300K SFC...AND MODELS IN GOOD AGREEMENT WITH HEAVY QPF AMOUNTS
ACROSS A LARGE PORTION OF THE SOUTHEAST PLAINS THROUGH
TUESDAY...PARTICULARLY NEAR THE MOUNTAINS. SNOW LEVELS WILL START OFF
AROUND 7000 FEET...BUT DROP TO AROUND 5000 FEET OVERNIGHT. TIMING
OF THE DROP IN TEMPERATURES AND THE RESIDUAL WARMTH OF THE GROUND
WILL PLAY A BIG ROLE IN HOW MUCH SNOW ACCUMULATES ACROSS THE LOWER
ELEVATIONS OF THE I-25 CORRIDOR SUCH AS SOUTHERN EL PASO AND PUEBLO
COUNTIES. HOWEVER...WITH GOOD MODEL CONSENSUS AND IMPRESSIVE TROWAL
ALOFT EXPECTED TO OVERWHELM DOWNSLOPE OFF THE PALMER AT LEAST
THROUGH THE 06Z TO 15Z WINDOW...HAVE OPTED TO ISSUE A WINTER WEATHER
ADVISORY FOR THE LOWER ELEVATIONS OF THE I-25 CORRIDOR...INCLUDING
COLORADO SPRINGS AND PUEBLO. SNOWFALL AMOUNTS WILL LIKELY EXHIBIT A
WIDE RANGE WITH SOME MELTING OFF ROAD SURFACES AT TIMES...BUT
ANYWHERE FROM 2 INCHES ON THE GRASS...TO AROUND 6 INCHES NEAR THE
MOUNTAINS SEEMS PLAUSIBLE. WITH A PERIOD OF EAST TO NORTHEAST WINDS
FUNNELING UP THE ARKANSAS RIVER...AND UPSLOPING ALONG THE WEST SIDE
OF THE LA GARITAS/AND EASTERN SAN JUANS...WILL INCLUDE THESE AREAS
IN A WINTER WEATHER ADVISORY AND RUN IT THROUGH 00Z. BIGGEST WINNER
IN THIS EVENT WILL BE THE EAST SLOPES OF THE SANGRES AND WETS 40 TO
50 KTS OF NORTHEAST UPSLOPE WILL RESULT IN 1 TO 2 FEET OF
SNOW...WITH HIGHER AMOUNTS ( UP TO 30 INCHES) ACROSS THE HIGHER
ELEVATIONS. REMAINDER OF THE HEADLINES IN GOOD SHAPE. TROWAL
EVENTUALLY PULLS OFF TO THE NORTHEAST ON TUESDAY WITH SNOW WINDING
DOWN FROM SOUTHWEST TO NORTHEAST DURING THE DAY ON TUESDAY. -KT
.LONG TERM...
(TUESDAY NIGHT-MONDAY)
...TIMING AND LOCATION OF UPPER LEVEL STORM LIFTING OUT ACROSS THE
SE PLAINS TUESDAY NIGHT THE MAIN FORECAST PROBLEM...
TUESDAY NIGHT-WEDNESDAY...SLIGHT MODEL DIFFERENCES ON TIMING AND
LOCATION OF UPPER LOW LIFTING OUT ACROSS THE SE PLAINS CONTINUE AND
HAVE TAILORED FORECAST TOWARDS THE NAM AND EC WHICH HAVE THE LOW
ACROSS EXTREME NORTHEAST NEW MEXICO AT 00Z WED AND THEN SLOWLY LIFT
IT OUT ACROSS WESTERN OKLAHOMA INTO CENTRAL OKLAHOMA THROUGH THE DAY
ON WEDNESDAY. ONGOING WRAP AROUND PRECIPITATION ACROSS THE EASTERN
MTS AND I-25 CORRIDOR TUESDAY AFTERNOON SLOWLY SHIFTS EAST AND
DIMINISHES FROM WEST TO EAST OVERNIGHT...AS UPPER LEVEL FLOW BECOMES
MORE NORTHWEST. COULD SEE SOME ADDITIONAL LIGHT ACCUMULATIONS OF A
COUPLE OF INCHES ACROSS THE NORTH AND EAST FACING SLOPES OF THE
EASTERN MTS AND ALONG WITH PALMER DVD AND RATON MESA TUESDAY EVENING
WITH THINGS WINDING INTO WEDNESDAY MORNING. TEMPERATURES ALOFT WARM
FROM WEST TO EAST THROUGH THE DAY ON WEDNESDAY...AS UPPER LEVEL
RIDGING BUILDS INTO THE STATE WITH HIGHS WARMING BACK TO AT OR
SLIGHTLY ABOVE SEASONAL AVERAGES...THOUGH HAVE TAPERED BACK HIGHS A
TAD IN EXPECTED SNOW COVERED AREAS.
WEDNESDAY NIGHT-MONDAY...WARMER AND DRIER WEATHER CONTINUES TO BE
PROGGED THROUGH THE PERIOD...WITH MODERATE TO STRONG WESTERLY FLOW
EXPECTED ACROSS THE REGION AS SEVERAL SHORT WAVES MOVE ACROSS THE
NORTHERN ROCKIES. ONE WAVE MOVES ACROSS THE REGION THURSDAY NIGHT
AND FRIDAY...WITH BREEZY TO WINDY CONDITIONS AND POSSIBLE CRITICAL
FIRE WEATHER CONDITIONS ON FRIDAY...DEPENDING ON HOW MUCH PRECIP
FALLS. PASSING WAVE SENDS A DRY COLD FRONT ACROSS THE PLAINS FRIDAY
WITH SLIGHTLY COOLER TEMPERATURES ACROSS THE AREA ON SATURDAY.
ANOTHER WAVE POSSIBLE MOVES ACROSS THE NORTHERN ROCKIES ON SUNDAY
NIGHT...WITH A BACKDOOR COLD FRONT POSSIBLE BRINGING IN ENOUGH LOW
LEVEL MOISTURE FOR A FEW SHOWERS ACROSS THE EASTERN PLAINS ON
MONDAY. HOWEVER...WILL KEEP A DRY FORECAST IN TACT THROUGH THE
PERIOD. -MW
&&
.AVIATION...
IFR CIGS/VIS EXPECTED TO AFFECT THE TAF SITES TONIGHT AS STRONG
SYSTEM MOVES ACROSS NORTHERN NEW MEXICO. STRONG NORTH WINDS IN THE
30 TO 45 KT RANGE WILL CONTINUE AT KCOS AND KPUB BEFORE DECREASING
TOWARDS 06Z. KALS WILL CONTINUE TO SEE EAST WINDS IN THE 25 TO 40
KT RANGE THROUGH EARLY EVENING WITH PERIODS OF BLDU. HEAVIEST SNOW
WILL IMPACT KCOS AND KPUB BETWEEN 06Z-18Z PERIOD WITH POTENTIAL FOR
A COUPLE INCHES OF SNOW...MAINLY ON GRASSY SURFACES AT KPUB...TO
AROUND 2 TO 5 INCHES AT KCOS. WITH WARM GROUND...THERE WILL BE SOME
MELTING AT TIMES AT KCOS...BUT PAVED SURFACES COULD BECOME SLUSHY
AND SNOWPACKED UNDER THE HEAVIER SNOW BANDS. KALS COULD SEE AN INCH
OR TWO AS WELL. RAIN/SNOW SWITCH OVER WILL OCCUR AROUND 03Z FOR
KCOS AND KALS...AND AROUND 06Z FOR KPUB. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ069>071-
084>086-089-093.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM MDT TUESDAY
FOR COZ078-087-088.
WINTER STORM WARNING UNTIL 6 PM MDT TUESDAY FOR COZ072>075-079-
080.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 6 PM MDT
TUESDAY FOR COZ058-060>063-076-077.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON MDT
TUESDAY FOR COZ083-085-086.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM MDT
TUESDAY FOR COZ066>068.
WINTER STORM WARNING FROM 9 PM THIS EVENING TO 6 PM MDT TUESDAY
FOR COZ081-082-084.
&&
$$
31/23
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1136 AM MDT MON APR 2 2012
.AVIATION...
STRONG WINTER STORM WILL CONTINUE AFFECTING THE REGION THROUGH
EARLY WEDNESDAY. AT KCOS AND KPUB...STRONG NORTHERLY WINDS WILL
CONTINUE THROUGH AT LEAST MIDDAY TUESDAY..WITH A MODEST DECREASE IN
WIND SPEEDS MONDAY EVENING. ISENTROPIC UPGLIDE WILL BE STRONG
ENOUGH TONIGHT TO OVERCOME THE DOWNGLIDE RESULTING FROM THE STRONG
NORTHERLY WINDS. TAFS HAVE SNOW WITH IFR CEILINGS AND VISIBILITIES
FROM MONDAY EVENING THROUGH AROUND 12Z TUESDAY. ACCUMULATIONS OF 2
TO 5 INCHES ARE FORECAST FOR KCOS. AT KPUB ACCUMULATIONS WILL BE
LIMITED TO AN INCH OR TWO ON GRASSY SURFACES. AFTER 12Z
TUESDAY...DOWNGLIDE FROM STRONG NORTHERLY WINDS WILL LIMIT
PRECIPITATION AT KCOS AND KPUB. HOWEVER...HEAVY PRECIPITATION IS
LIKELY NORTH OF KCOS AND SOUTH OF KPUB. AT KALS...STRONG EASTERLY
WINDS WILL WEAKEN DURING THE EVENING. UPPER LEVEL FORCING SHOULD
BE STRONG ENOUGH TO PRODUCE SNOW AT KALS OVERNIGHT...WITH CHANCES
FOR SNOW DECREASING AFTER 12Z TUESDAY. --PGW--
&&
.PREV DISCUSSION... /ISSUED 1017 AM MDT MON APR 2 2012/
UPDATE...
LATEST HRRR AND LOCAL 4 KM WRF ALSO SHOWING ANOTHER INCREASE IN
THE WIND GUSTS LATER THIS AFTERNOON THROUGH THIS EVENING
ALONG/SOUTH OF THE PALMER DIVIDE. THUS WILL BE EXTENDING THE HIGH
WIND WARNING THROUGH 03Z. -KT
PREV DISCUSSION... /ISSUED 1007 AM MDT MON APR 2 2012/
UPDATE...
HIGH RES MODELS...HRRR...LOCAL 4 KM WRF ALL POINTING TO POTENTIAL
HIGH WIND EVENT FOR THE EASTERN PORTIONS OF THE SAN LUIS VALLEY
WHERE EASTERLY WINDS WILL POUR THROUGH THE GAPS AND VALLEYS OF THE
SANGRES. GIVEN THE STRONG PRESSURE GRADIENT BEHIND THE
FRONT...THIS SEEMS PLAUSIBLE...AND HAVE PUT OUT A HIGH WIND
WARNING FOR THE SAN LUIS VALLEY TO ACCOUNT FOR THIS. HRRR AND
LOCAL 4 KM WRF ALL INDICATE POTENTIAL FOR GUSTS IN EXCESS OF 60 TO
EVEN 70 MPH. SUSPECT THIS WILL BE FAIRLY LOCALIZED TO THE EASTERN
FRINGES OF THE SAN LUIS VALLEY. HIGH WIND WARING ALREADY OUT.
UPDATED GRIDS AND FORECAST TO FOLLOW SHORTLY. -KT
PREV DISCUSSION... /ISSUED 428 AM MDT MON APR 2 2012/
SHORT TERM...
(TODAY AND TONIGHT)
MAJOR SPRING STORM TO AFFECT OUR AREA...
IRONICALLY...IT LOOKS LIKE THE BIGGEST STORM OF THIS SEASON WILL
COME IN SPRING THIS YEAR. A STRONG COLD FRONT HAS ALREADY MOVED
THROUGH THE NRN TIER OF OUR CWA THIS MORN..WITH GUSTS TO 40 KT
ALREADY BEING REPORTED AT KCOS. THESE WINDS WILL CONTINUE TO
INCREASE THROUGH THE MORNING HOURS...WITH SUSTAINED WINDS OF 30-40
KT LIKELY AND SOME GUSTS IN THE 50-60 KT RANGE POSSIBLE. WILL
CONTINUE THE HIGH WIND WARNING...AND EXTEND THROUGH THIS AFTERNOON
AS IT NOW LOOKS LIKE SUSTAINED WINDS COULD MEET HIGH WIND CRITERIA
FOR AT LEAST SOME OF THIS AREA THROUGH THE DAY.
STILL SEEING VERY DRY AND MILD CONDITIONS ACROSS THE PLAINS. TEMPS
HAVE BEEN CLIMBING STEADILY AT KPUB WITH FRONTAL SUBSIDENCE. DEWPOINTS
ARE RISING CONSIDERABLY BEHIND THE FRONT...BUT REAL MOIST AIR WILL
HOLD OFF TIL LATER TODAY. SKIES ARE STILL CLR THIS MORN AND LOW
CLOUDS IN THE SAT FOG PRODUCT ARE CONFINED TO NW CO ATTM. HAVE SEEN
CONTINUED LIGHT-MDT ECHOES OVR WRN CO ALL MORNING...AND WHILE OBS
ARE RATHER DEVOID OF PRECIP...SUSPECT THE HIGHER PEAKS ARE SEEING
SOME PRECIP THIS MORN.
THE FRONT WILL SET THE STAGE FOR A VERY DYNAMIC SYSTEM THAT IS NOW
MOVING INTO THE 4 CORNERS REGION. THIS SYSTEM WILL CONTINUE TO STRONGLY
INTENSIFY AS A VERY STRONG MID LEVEL JET STREAK MOVES THROUGH SRN
NM. THE UPPER LOW WILL TRACK JUST S OF KABQ THIS AFTERNOON...AS A
CLASSIC AND INFAMOUS `ALBUQUERQUE LOW`. WILL SEE TEMPS HOLD STEADY OR
FALL LATER TODAY AS COLD AIR CONTINUES TO POUR IN BEHIND THE
FRONT...AND H7 TEMPS FALL TO MINUS 8 TO MINUS 10 BY THIS EVE.
MAIN ACTION WITH THIS STORM WILL BE TONIGHT...AS THE JET BEGINS TO
ROUND THE TROUGH BASE AND THE UPPER LOW MAKE A MOVE TO THE NE. THIS
IS THE TRACK THAT HAS BEEN FAVORED BY THE GFS AND ECMWF FOR THE LAST
COUPLE OF DAYS...AND THE NAM HAS FINALLY CAUGHT ON TO THIS SOLUTION
IN A BIG WAY. TIMING WILL BE PERFECT FOR A HEAVY SNOW
EVENT...ESPECIALLY OVER THE HIGHER ELEVATIONS...AND COULD EVEN SEE
SOME SNOW AT THE LOWER ELEVATIONS DUE TO THE FAVORABLE OVERNIGHT
TIMING AND PRIMED CONDITIONS. WET BULB ZERO WILL FALL STEADILY FROM
AROUND 6500 FT TODAY TO AS LOW AS 4500 FEET TONIGHT. EXPECT THAT
MOST LOCATIONS ABOVE 6000 FEET...INCLUDING KCOS...WILL SEE SOME
SNOW. OF COURSE...WITH VERY WARM GROUND MUCH OF THE EARLY SNOWFALL
WILL FAIL TO ACCUMULATE INITIALLY...BUT WITH A GOOD 8-12 H PERIOD OF
SNOW COULD SEE SOME LIGHT ACCUMS FOR THE I-25 CORRIDOR. KCOS LOOKS
TO BE SOLIDLY BELOW FZG FOR THE MAIN EVENT...AS THE TROWAL REALLY
KICKS IN FROM 03Z TO 12Z OVERNIGHT. ANY PRECIP BEFORE 03Z WILL
LIKELY BE RAIN OR A RN/SN MIX. N WINDS MAY LIMIT PRECIP FOR S EL
PASO AND N PUEBLO COUNTIES...BUT VERY STRONG ISENTROPIC LIFT MAY
OVERCOME SOME OF THE DOWNSLOPE DRYING EFFECT.
AS FOR `WINTER` HEADLINES...HAVE CONVERTED OUR WATCH TO A
WARNING...AND ADDED THE WET MOUNTAIN VALLEY AS WELL. WOULD NOT BE
SURPRISED TO SEE IN EXCESS OF 2 FEET FOR THE HIGHEST ELEVATIONS OF
THE WETS/SANGRES...IF CURRENT PROGS PAN OUT AS EXPECTED. RATON PASS
WILL BE PARTICULARLY PROBLEMATIC TONIGHT AND TUE AS STRONG N WINDS
COMBINE WITH SN TO PRODUCE WHITE OUT CONDITIONS AT TIMES. CONSIDERED
UPGRADING TO A BLIZZARD WARNING FOR THE RATON...BUT CURRENTLY DOES NOT
LOOK LIKE WINDS WILL BE SUSTAINED LONG ENOUGH...AND HEAVIEST PRECIP
OCCURS AFTER THE STRONGEST WINDS. HOWEVER...WILL NEED TO WATCH THIS
AREA CLOSELY. ALSO HAVE INTRODUCED A WINTER STORM WATCH FOR TELLER
AND N EL PASO FOR TONIGHT AND TUE. COULD GET PRETTY NASTY OVER
MONUMENT HILL BY TUE. HOPEFULLY THIS STORM WILL PUT A DENT IN THE
DROUGHT. LET IT SNOW! 44
LONG TERM...
(TUESDAY - SUNDAY)
BENEFICIAL PRECIP AT THE BEGINNING OF THE PD THEN DRYING OUT
AGAIN...
MODELS IN THE EARLY PART OF THIS FCST PD HAVE COME INTO GOOD AGREEMENT
BRINGING THE CUTOFF LOW NORTHEASTWARD ACROSS SE CO.
BY 12Z TUESDAY...SNOW AND RAIN SHOULD BE ONGOING ACROSS A GOOD PART
OF THE REGION...WITH THE BEST CHANCE OF PRECIP OVER THE EAST FACING
SLOPES OF THE MTNS ADJ TO THE PLAINS...AND THE RATON MESA AND PALMER
DVD REGIONS. THE RAIN/SNOW LINE AT 12Z WILL LIKELY BE AROUND 5000
FEET. FOR THE MORNING RUSH HOUR...SNOW WILL LIKELY NOT ACCUMULATE
MUCH ON ROAD SURFACES BETWEEN 5000 AND 6500 FEET...BUT ANYTHING
ABOVE 6500 FEET WILL LIKELY BECOME SLUSHY. GRASSY SFCS BETWEEN THE
AFOREMENTIONED ELEVATIONS WILL LIKELY ACCUMULATE SOME SNOW...SO
THE PUEBLO AREA MAY SEE AN INCH OF MEASURABLE SNOW. OVERALL...TWO
TO THREE INCHES OF SNOW WILL LIKELY OCCUR ACROSS THE EASTERN
MTNS/RATON MESA AND PALMER DVD...WITH LOCALLY HEAVY ACCUMS ACROSS
PIKES PEAK AND THE HIGHER ELEVATIONS OF THE EAST SLOPES OF THE
WETS/SANGRES.
BY MIDDAY TUESDAY...THE LOW CENTER ALOFT WILL LIKELY BE IN THE SE
CO AREA AND 700 MB FLOW WILL BECOME MORE NORTHERLY ACROSS THE
WETS/SANGRES. THIS SHOULD ALLOW THE SNOW TO DECREASE ACROSS THESE
REGIONS AS THE FLOW WILL NOT BE AS FAVORABLE...BUT FARTHER NORTH
ACROSS THE GREATER PIKES PEAK REGION MODEST NE 700 MB FLOW WILL BE
ONGOING. LIKEWISE...THE PALMER DVD REGION AND RAMPARTS/PIKES PEAK
WILL LIKELY SEE SNOW CONTINUING. THE RAIN/SNOW LINE SHOULD
INCREASE A BIT DURING THE DAY...BUT NOT BY MUCH.
BY LATE IN THE DAY TUESDAY THE RAIN/SNOW SHOULD PRETTY MUCH BE OVER
ACROSS THE PLAINS...HOWEVER BOTH NAM/GFS SHOW WRAP AROUND PRECIP
CONTINUING OVER THE HIGHER TRRN OF THE MTNS..ESPECIALLY THE SANGRES
AND SAN JUANS. FOR THIS REASON I HAVE INCREASED POPS OVER THESE
REGIONS DURING THIS TIME. NOTE THAT THE WINTER STORM WARNING FOR THE
SANGRES EXPIRES AT 00Z WED. IF THE MODELS ARE CORRECT...THIS WARNING
MAY NEED TO BE EXTENDED FOR THIS MTN RANGE BY ABOUT 6 HOURS OR SO.
AS FOR HIGH TEMPERATURES ON TUESDAY...I HAVE DECREASED THEM...WITH
TEMPS REACHING ABOUT 40F ALONG THE I-25 CORRIDOR REGION...AND
THESE VALUES MAY BE A BIT TOO HIGH IF THE MODEL SOUNDINGS ARE CORRECT.
OVER THE FAR E PLAINS AND SAN LUIS VALLEY...HIGHS SHOULD BE ABOUT
50F.
AS FOR THE REST OF THE FCST...WE WILL BE RETURNING TO A DRY PATTERN
AGAIN AS SW FLOW GRADUALLY RAMPS UP ONCE AGAIN. IF WE DO GET AS MUCH
PRECIP AS THE MODELS ARE INDICATING...THEN FIRE WX CONCERNS SHOULD
DROP SIGNIFICANTLY ACROSS THE FCST AREA. ATTM...THE WARMEST TEMPS
SHOULD BE DURING THE FRI-SAT TIME FRAME WITH A DRY PAC FRONT COMING
ACROSS THE REGION SAT NITE. TEMPS WILL COOL AGAIN ON SUNDAY.
THE NEXT CHANCE OF PRECIP...ACCORDING TO THE GFS WILL BE
MONDAY...BUT THE EC SIMULATION IS DRY FROM WED THROUGH NEXT WEEK.
/34
AVIATION...
STRONG N WINDS BEHIND A COLD FRONT WILL CONTINUE TO AFFECT KCOS AND KPUB
THROUGH THE NEXT 6-12 H. SUSTAINED WINDS FORM 30-40 KTS WITH HIGHER GUSTS
WILL BE POSSIBLE. WINDS WILL GRADUALLY DIMINISH THIS
EVE...HOWEVER...PRECIP IS EXPECTED TO BECOME MORE LIKELY
OVERNIGHT...WITH A GOOD CHANE OF SN AT KCOS AND A RAIN-SNOW MIX
POSSIBLE AT KPUB LATER TONIGHT. ALONG WITH GUSTY WINDS VIS IS
EXPECTED TO BE LOW OVERNIGHT IN PARTICULAR. KALS WILL ALSO SEE GUSTY
NE WINDS AND THE CHANCE OF SOME SHSN...BUT THE WORST CONDITIONS WILL
BE ALONG AND W OF I-25. 44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ069>071-
084>086-089-093.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM MDT TUESDAY
FOR COZ078-087-088.
WINTER STORM WARNING UNTIL 6 PM MDT TUESDAY FOR COZ072>075-079-
080.
WINTER STORM WATCH FROM 9 PM MDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR COZ081-082-084.
&&
$$
06/06
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
1017 AM MDT MON APR 2 2012
.UPDATE...
LATEST HRRR AND LOCAL 4 KM WRF ALSO SHOWING ANOTHER INCREASE IN
THE WIND GUSTS LATER THIS AFTERNOON THROUGH THIS EVENING
ALONG/SOUTH OF THE PALMER DIVIDE. THUS WILL BE EXTENDING THE HIGH
WIND WARNING THROUGH 03Z. -KT
&&
.PREV DISCUSSION... /ISSUED 1007 AM MDT MON APR 2 2012/
UPDATE...
HIGH RES MODELS...HRRR...LOCAL 4 KM WRF ALL POINTING TO POTENTIAL
HIGH WIND EVENT FOR THE EASTERN PORTIONS OF THE SAN LUIS VALLEY
WHERE EASTERLY WINDS WILL POUR THROUGH THE GAPS AND VALLEYS OF THE
SANGRES. GIVEN THE STRONG PRESSURE GRADIENT BEHIND THE
FRONT...THIS SEEMS PLAUSIBLE...AND HAVE PUT OUT A HIGH WIND
WARNING FOR THE SAN LUIS VALLEY TO ACCOUNT FOR THIS. HRRR AND
LOCAL 4 KM WRF ALL INDICATE POTENTIAL FOR GUSTS IN EXCESS OF 60 TO
EVEN 70 MPH. SUSPECT THIS WILL BE FAIRLY LOCALIZED TO THE EASTERN
FRINGES OF THE SAN LUIS VALLEY. HIGH WIND WARING ALREADY OUT.
UPDATED GRIDS AND FORECAST TO FOLLOW SHORTLY. -KT
PREV DISCUSSION... /ISSUED 428 AM MDT MON APR 2 2012/
SHORT TERM...
(TODAY AND TONIGHT)
.MAJOR SPRING STORM TO AFFECT OUR AREA...
IRONICALLY...IT LOOKS LIKE THE BIGGEST STORM OF THIS SEASON WILL
COME IN SPRING THIS YEAR. A STRONG COLD FRONT HAS ALREADY MOVED
THROUGH THE NRN TIER OF OUR CWA THIS MORN..WITH GUSTS TO 40 KT
ALREADY BEING REPORTED AT KCOS. THESE WINDS WILL CONTINUE TO
INCREASE THROUGH THE MORNING HOURS...WITH SUSTAINED WINDS OF 30-40
KT LIKELY AND SOME GUSTS IN THE 50-60 KT RANGE POSSIBLE. WILL
CONTINUE THE HIGH WIND WARNING...AND EXTEND THROUGH THIS AFTERNOON
AS IT NOW LOOKS LIKE SUSTAINED WINDS COULD MEET HIGH WIND CRITERIA
FOR AT LEAST SOME OF THIS AREA THROUGH THE DAY.
STILL SEEING VERY DRY AND MILD CONDITIONS ACROSS THE PLAINS. TEMPS
HAVE BEEN CLIMBING STEADILY AT KPUB WITH FRONTAL SUBSIDENCE. DEWPOINTS
ARE RISING CONSIDERABLY BEHIND THE FRONT...BUT REAL MOIST AIR WILL
HOLD OFF TIL LATER TODAY. SKIES ARE STILL CLR THIS MORN AND LOW
CLOUDS IN THE SAT FOG PRODUCT ARE CONFINED TO NW CO ATTM. HAVE SEEN
CONTINUED LIGHT-MDT ECHOES OVR WRN CO ALL MORNING...AND WHILE OBS
ARE RATHER DEVOID OF PRECIP...SUSPECT THE HIGHER PEAKS ARE SEEING
SOME PRECIP THIS MORN.
THE FRONT WILL SET THE STAGE FOR A VERY DYNAMIC SYSTEM THAT IS NOW
MOVING INTO THE 4 CORNERS REGION. THIS SYSTEM WILL CONTINUE TO STRONGLY
INTENSIFY AS A VERY STRONG MID LEVEL JET STREAK MOVES THROUGH SRN
NM. THE UPPER LOW WILL TRACK JUST S OF KABQ THIS AFTERNOON...AS A
CLASSIC AND INFAMOUS `ALBUQUERQUE LOW`. WILL SEE TEMPS HOLD STEADY OR
FALL LATER TODAY AS COLD AIR CONTINUES TO POUR IN BEHIND THE
FRONT...AND H7 TEMPS FALL TO MINUS 8 TO MINUS 10 BY THIS EVE.
MAIN ACTION WITH THIS STORM WILL BE TONIGHT...AS THE JET BEGINS TO
ROUND THE TROUGH BASE AND THE UPPER LOW MAKE A MOVE TO THE NE. THIS
IS THE TRACK THAT HAS BEEN FAVORED BY THE GFS AND ECMWF FOR THE LAST
COUPLE OF DAYS...AND THE NAM HAS FINALLY CAUGHT ON TO THIS SOLUTION
IN A BIG WAY. TIMING WILL BE PERFECT FOR A HEAVY SNOW
EVENT...ESPECIALLY OVER THE HIGHER ELEVATIONS...AND COULD EVEN SEE
SOME SNOW AT THE LOWER ELEVATIONS DUE TO THE FAVORABLE OVERNIGHT
TIMING AND PRIMED CONDITIONS. WET BULB ZERO WILL FALL STEADILY FROM
AROUND 6500 FT TODAY TO AS LOW AS 4500 FEET TONIGHT. EXPECT THAT
MOST LOCATIONS ABOVE 6000 FEET...INCLUDING KCOS...WILL SEE SOME
SNOW. OF COURSE...WITH VERY WARM GROUND MUCH OF THE EARLY SNOWFALL
WILL FAIL TO ACCUMULATE INITIALLY...BUT WITH A GOOD 8-12 H PERIOD OF
SNOW COULD SEE SOME LIGHT ACCUMS FOR THE I-25 CORRIDOR. KCOS LOOKS
TO BE SOLIDLY BELOW FZG FOR THE MAIN EVENT...AS THE TROWAL REALLY
KICKS IN FROM 03Z TO 12Z OVERNIGHT. ANY PRECIP BEFORE 03Z WILL
LIKELY BE RAIN OR A RN/SN MIX. N WINDS MAY LIMIT PRECIP FOR S EL
PASO AND N PUEBLO COUNTIES...BUT VERY STRONG ISENTROPIC LIFT MAY
OVERCOME SOME OF THE DOWNSLOPE DRYING EFFECT.
AS FOR `WINTER` HEADLINES...HAVE CONVERTED OUR WATCH TO A
WARNING...AND ADDED THE WET MOUNTAIN VALLEY AS WELL. WOULD NOT BE
SURPRISED TO SEE IN EXCESS OF 2 FEET FOR THE HIGHEST ELEVATIONS OF
THE WETS/SANGRES...IF CURRENT PROGS PAN OUT AS EXPECTED. RATON PASS
WILL BE PARTICULARLY PROBLEMATIC TONIGHT AND TUE AS STRONG N WINDS
COMBINE WITH SN TO PRODUCE WHITE OUT CONDITIONS AT TIMES. CONSIDERED
UPGRADING TO A BLIZZARD WARNING FOR THE RATON...BUT CURRENTLY DOES NOT
LOOK LIKE WINDS WILL BE SUSTAINED LONG ENOUGH...AND HEAVIEST PRECIP
OCCURS AFTER THE STRONGEST WINDS. HOWEVER...WILL NEED TO WATCH THIS
AREA CLOSELY. ALSO HAVE INTRODUCED A WINTER STORM WATCH FOR TELLER
AND N EL PASO FOR TONIGHT AND TUE. COULD GET PRETTY NASTY OVER
MONUMENT HILL BY TUE. HOPEFULLY THIS STORM WILL PUT A DENT IN THE
DROUGHT. LET IT SNOW! 44
LONG TERM...
(TUESDAY - SUNDAY)
.BENEFICIAL PRECIP AT THE BEGINNING OF THE PD THEN DRYING OUT
AGAIN...
MODELS IN THE EARLY PART OF THIS FCST PD HAVE COME INTO GOOD AGREEMENT
BRINGING THE CUTOFF LOW NORTHEASTWARD ACROSS SE CO.
BY 12Z TUESDAY...SNOW AND RAIN SHOULD BE ONGOING ACROSS A GOOD PART
OF THE REGION...WITH THE BEST CHANCE OF PRECIP OVER THE EAST FACING
SLOPES OF THE MTNS ADJ TO THE PLAINS...AND THE RATON MESA AND PALMER
DVD REGIONS. THE RAIN/SNOW LINE AT 12Z WILL LIKELY BE AROUND 5000
FEET. FOR THE MORNING RUSH HOUR...SNOW WILL LIKELY NOT ACCUMULATE
MUCH ON ROAD SURFACES BETWEEN 5000 AND 6500 FEET...BUT ANYTHING
ABOVE 6500 FEET WILL LIKELY BECOME SLUSHY. GRASSY SFCS BETWEEN THE
AFOREMENTIONED ELEVATIONS WILL LIKELY ACCUMULATE SOME SNOW...SO
THE PUEBLO AREA MAY SEE AN INCH OF MEASURABLE SNOW. OVERALL...TWO
TO THREE INCHES OF SNOW WILL LIKELY OCCUR ACROSS THE EASTERN
MTNS/RATON MESA AND PALMER DVD...WITH LOCALLY HEAVY ACCUMS ACROSS
PIKES PEAK AND THE HIGHER ELEVATIONS OF THE EAST SLOPES OF THE
WETS/SANGRES.
BY MIDDAY TUESDAY...THE LOW CENTER ALOFT WILL LIKELY BE IN THE SE
CO AREA AND 700 MB FLOW WILL BECOME MORE NORTHERLY ACROSS THE
WETS/SANGRES. THIS SHOULD ALLOW THE SNOW TO DECREASE ACROSS THESE
REGIONS AS THE FLOW WILL NOT BE AS FAVORABLE...BUT FARTHER NORTH
ACROSS THE GREATER PIKES PEAK REGION MODEST NE 700 MB FLOW WILL BE
ONGOING. LIKEWISE...THE PALMER DVD REGION AND RAMPARTS/PIKES PEAK
WILL LIKELY SEE SNOW CONTINUING. THE RAIN/SNOW LINE SHOULD
INCREASE A BIT DURING THE DAY...BUT NOT BY MUCH.
BY LATE IN THE DAY TUESDAY THE RAIN/SNOW SHOULD PRETTY MUCH BE OVER
ACROSS THE PLAINS...HOWEVER BOTH NAM/GFS SHOW WRAP AROUND PRECIP
CONTINUING OVER THE HIGHER TRRN OF THE MTNS..ESPECIALLY THE SANGRES
AND SAN JUANS. FOR THIS REASON I HAVE INCREASED POPS OVER THESE
REGIONS DURING THIS TIME. NOTE THAT THE WINTER STORM WARNING FOR THE
SANGRES EXPIRES AT 00Z WED. IF THE MODELS ARE CORRECT...THIS WARNING
MAY NEED TO BE EXTENDED FOR THIS MTN RANGE BY ABOUT 6 HOURS OR SO.
AS FOR HIGH TEMPERATURES ON TUESDAY...I HAVE DECREASED THEM...WITH
TEMPS REACHING ABOUT 40F ALONG THE I-25 CORRIDOR REGION...AND
THESE VALUES MAY BE A BIT TOO HIGH IF THE MODEL SOUNDINGS ARE CORRECT.
OVER THE FAR E PLAINS AND SAN LUIS VALLEY...HIGHS SHOULD BE ABOUT
50F.
AS FOR THE REST OF THE FCST...WE WILL BE RETURNING TO A DRY PATTERN
AGAIN AS SW FLOW GRADUALLY RAMPS UP ONCE AGAIN. IF WE DO GET AS MUCH
PRECIP AS THE MODELS ARE INDICATING...THEN FIRE WX CONCERNS SHOULD
DROP SIGNIFICANTLY ACROSS THE FCST AREA. ATTM...THE WARMEST TEMPS
SHOULD BE DURING THE FRI-SAT TIME FRAME WITH A DRY PAC FRONT COMING
ACROSS THE REGION SAT NITE. TEMPS WILL COOL AGAIN ON SUNDAY.
THE NEXT CHANCE OF PRECIP...ACCORDING TO THE GFS WILL BE
MONDAY...BUT THE EC SIMULATION IS DRY FROM WED THROUGH NEXT WEEK.
/34
AVIATION...
STRONG N WINDS BEHIND A COLD FRONT WILL CONTINUE TO AFFECT KCOS AND KPUB
THROUGH THE NEXT 6-12 H. SUSTAINED WINDS FORM 30-40 KTS WITH HIGHER GUSTS
WILL BE POSSIBLE. WINDS WILL GRADUALLY DIMINISH THIS
EVE...HOWEVER...PRECIP IS EXPECTED TO BECOME MORE LIKELY
OVERNIGHT...WITH A GOOD CHANE OF SN AT KCOS AND A RAIN-SNOW MIX
POSSIBLE AT KPUB LATER TONIGHT. ALONG WITH GUSTY WINDS VIS IS
EXPECTED TO BE LOW OVERNIGHT IN PARTICULAR. KALS WILL ALSO SEE GUSTY
NE WINDS AND THE CHANCE OF SOME SHSN...BUT THE WORST CONDITIONS WILL
BE ALONG AND W OF I-25. 44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ069>071-
084>086-089-093.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM MDT TUESDAY
FOR COZ078-087-088.
WINTER STORM WARNING UNTIL 6 PM MDT TUESDAY FOR COZ072>075-079-
080.
WINTER STORM WATCH FROM 9 PM MDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR COZ081-082-084.
&&
$$
31/23
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1007 AM MDT MON APR 2 2012
.UPDATE...
HIGH RES MODELS...HRRR...LOCAL 4 KM WRF ALL POINTING TO POTENTIAL
HIGH WIND EVENT FOR THE EASTERN PORTIONS OF THE SAN LUIS VALLEY
WHERE EASTERLY WINDS WILL POUR THROUGH THE GAPS AND VALLEYS OF THE
SANGRES. GIVEN THE STRONG PRESSURE GRADIENT BEHIND THE
FRONT...THIS SEEMS PLAUSIBLE...AND HAVE PUT OUT A HIGH WIND
WARNING FOR THE SAN LUIS VALLEY TO ACCOUNT FOR THIS. HRRR AND
LOCAL 4 KM WRF ALL INDICATE POTENTIAL FOR GUSTS IN EXCESS OF 60 TO
EVEN 70 MPH. SUSPECT THIS WILL BE FAIRLY LOCALIZED TO THE EASTERN
FRINGES OF THE SAN LUIS VALLEY. HIGH WIND WARING ALREADY OUT.
UPDATED GRIDS AND FORECAST TO FOLLOW SHORTLY. -KT
&&
.PREV DISCUSSION... /ISSUED 428 AM MDT MON APR 2 2012/
SHORT TERM...
(TODAY AND TONIGHT)
..MAJOR SPRING STORM TO AFFECT OUR AREA...
IRONICALLY...IT LOOKS LIKE THE BIGGEST STORM OF THIS SEASON WILL
COME IN SPRING THIS YEAR. A STRONG COLD FRONT HAS ALREADY MOVED
THROUGH THE NRN TIER OF OUR CWA THIS MORN..WITH GUSTS TO 40 KT
ALREADY BEING REPORTED AT KCOS. THESE WINDS WILL CONTINUE TO
INCREASE THROUGH THE MORNING HOURS...WITH SUSTAINED WINDS OF 30-40
KT LIKELY AND SOME GUSTS IN THE 50-60 KT RANGE POSSIBLE. WILL
CONTINUE THE HIGH WIND WARNING...AND EXTEND THROUGH THIS AFTERNOON
AS IT NOW LOOKS LIKE SUSTAINED WINDS COULD MEET HIGH WIND CRITERIA
FOR AT LEAST SOME OF THIS AREA THROUGH THE DAY.
STILL SEEING VERY DRY AND MILD CONDITIONS ACROSS THE PLAINS. TEMPS
HAVE BEEN CLIMBING STEADILY AT KPUB WITH FRONTAL SUBSIDENCE. DEWPOINTS
ARE RISING CONSIDERABLY BEHIND THE FRONT...BUT REAL MOIST AIR WILL
HOLD OFF TIL LATER TODAY. SKIES ARE STILL CLR THIS MORN AND LOW
CLOUDS IN THE SAT FOG PRODUCT ARE CONFINED TO NW CO ATTM. HAVE SEEN
CONTINUED LIGHT-MDT ECHOES OVR WRN CO ALL MORNING...AND WHILE OBS
ARE RATHER DEVOID OF PRECIP...SUSPECT THE HIGHER PEAKS ARE SEEING
SOME PRECIP THIS MORN.
THE FRONT WILL SET THE STAGE FOR A VERY DYNAMIC SYSTEM THAT IS NOW
MOVING INTO THE 4 CORNERS REGION. THIS SYSTEM WILL CONTINUE TO STRONGLY
INTENSIFY AS A VERY STRONG MID LEVEL JET STREAK MOVES THROUGH SRN
NM. THE UPPER LOW WILL TRACK JUST S OF KABQ THIS AFTERNOON...AS A
CLASSIC AND INFAMOUS `ALBUQUERQUE LOW`. WILL SEE TEMPS HOLD STEADY OR
FALL LATER TODAY AS COLD AIR CONTINUES TO POUR IN BEHIND THE
FRONT...AND H7 TEMPS FALL TO MINUS 8 TO MINUS 10 BY THIS EVE.
MAIN ACTION WITH THIS STORM WILL BE TONIGHT...AS THE JET BEGINS TO
ROUND THE TROUGH BASE AND THE UPPER LOW MAKE A MOVE TO THE NE. THIS
IS THE TRACK THAT HAS BEEN FAVORED BY THE GFS AND ECMWF FOR THE LAST
COUPLE OF DAYS...AND THE NAM HAS FINALLY CAUGHT ON TO THIS SOLUTION
IN A BIG WAY. TIMING WILL BE PERFECT FOR A HEAVY SNOW
EVENT...ESPECIALLY OVER THE HIGHER ELEVATIONS...AND COULD EVEN SEE
SOME SNOW AT THE LOWER ELEVATIONS DUE TO THE FAVORABLE OVERNIGHT
TIMING AND PRIMED CONDITIONS. WET BULB ZERO WILL FALL STEADILY FROM
AROUND 6500 FT TODAY TO AS LOW AS 4500 FEET TONIGHT. EXPECT THAT
MOST LOCATIONS ABOVE 6000 FEET...INCLUDING KCOS...WILL SEE SOME
SNOW. OF COURSE...WITH VERY WARM GROUND MUCH OF THE EARLY SNOWFALL
WILL FAIL TO ACCUMULATE INITIALLY...BUT WITH A GOOD 8-12 H PERIOD OF
SNOW COULD SEE SOME LIGHT ACCUMS FOR THE I-25 CORRIDOR. KCOS LOOKS
TO BE SOLIDLY BELOW FZG FOR THE MAIN EVENT...AS THE TROWAL REALLY
KICKS IN FROM 03Z TO 12Z OVERNIGHT. ANY PRECIP BEFORE 03Z WILL
LIKELY BE RAIN OR A RN/SN MIX. N WINDS MAY LIMIT PRECIP FOR S EL
PASO AND N PUEBLO COUNTIES...BUT VERY STRONG ISENTROPIC LIFT MAY
OVERCOME SOME OF THE DOWNSLOPE DRYING EFFECT.
AS FOR `WINTER` HEADLINES...HAVE CONVERTED OUR WATCH TO A
WARNING...AND ADDED THE WET MOUNTAIN VALLEY AS WELL. WOULD NOT BE
SURPRISED TO SEE IN EXCESS OF 2 FEET FOR THE HIGHEST ELEVATIONS OF
THE WETS/SANGRES...IF CURRENT PROGS PAN OUT AS EXPECTED. RATON PASS
WILL BE PARTICULARLY PROBLEMATIC TONIGHT AND TUE AS STRONG N WINDS
COMBINE WITH SN TO PRODUCE WHITE OUT CONDITIONS AT TIMES. CONSIDERED
UPGRADING TO A BLIZZARD WARNING FOR THE RATON...BUT CURRENTLY DOES NOT
LOOK LIKE WINDS WILL BE SUSTAINED LONG ENOUGH...AND HEAVIEST PRECIP
OCCURS AFTER THE STRONGEST WINDS. HOWEVER...WILL NEED TO WATCH THIS
AREA CLOSELY. ALSO HAVE INTRODUCED A WINTER STORM WATCH FOR TELLER
AND N EL PASO FOR TONIGHT AND TUE. COULD GET PRETTY NASTY OVER
MONUMENT HILL BY TUE. HOPEFULLY THIS STORM WILL PUT A DENT IN THE
DROUGHT. LET IT SNOW! 44
LONG TERM...
(TUESDAY - SUNDAY)
..BENEFICIAL PRECIP AT THE BEGINNING OF THE PD THEN DRYING OUT
AGAIN...
MODELS IN THE EARLY PART OF THIS FCST PD HAVE COME INTO GOOD AGREEMENT
BRINGING THE CUTOFF LOW NORTHEASTWARD ACROSS SE CO.
BY 12Z TUESDAY...SNOW AND RAIN SHOULD BE ONGOING ACROSS A GOOD PART
OF THE REGION...WITH THE BEST CHANCE OF PRECIP OVER THE EAST FACING
SLOPES OF THE MTNS ADJ TO THE PLAINS...AND THE RATON MESA AND PALMER
DVD REGIONS. THE RAIN/SNOW LINE AT 12Z WILL LIKELY BE AROUND 5000
FEET. FOR THE MORNING RUSH HOUR...SNOW WILL LIKELY NOT ACCUMULATE
MUCH ON ROAD SURFACES BETWEEN 5000 AND 6500 FEET...BUT ANYTHING
ABOVE 6500 FEET WILL LIKELY BECOME SLUSHY. GRASSY SFCS BETWEEN THE
AFOREMENTIONED ELEVATIONS WILL LIKELY ACCUMULATE SOME SNOW...SO
THE PUEBLO AREA MAY SEE AN INCH OF MEASURABLE SNOW. OVERALL...TWO
TO THREE INCHES OF SNOW WILL LIKELY OCCUR ACROSS THE EASTERN
MTNS/RATON MESA AND PALMER DVD...WITH LOCALLY HEAVY ACCUMS ACROSS
PIKES PEAK AND THE HIGHER ELEVATIONS OF THE EAST SLOPES OF THE
WETS/SANGRES.
BY MIDDAY TUESDAY...THE LOW CENTER ALOFT WILL LIKELY BE IN THE SE
CO AREA AND 700 MB FLOW WILL BECOME MORE NORTHERLY ACROSS THE
WETS/SANGRES. THIS SHOULD ALLOW THE SNOW TO DECREASE ACROSS THESE
REGIONS AS THE FLOW WILL NOT BE AS FAVORABLE...BUT FARTHER NORTH
ACROSS THE GREATER PIKES PEAK REGION MODEST NE 700 MB FLOW WILL BE
ONGOING. LIKEWISE...THE PALMER DVD REGION AND RAMPARTS/PIKES PEAK
WILL LIKELY SEE SNOW CONTINUING. THE RAIN/SNOW LINE SHOULD
INCREASE A BIT DURING THE DAY...BUT NOT BY MUCH.
BY LATE IN THE DAY TUESDAY THE RAIN/SNOW SHOULD PRETTY MUCH BE OVER
ACROSS THE PLAINS...HOWEVER BOTH NAM/GFS SHOW WRAP AROUND PRECIP
CONTINUING OVER THE HIGHER TRRN OF THE MTNS..ESPECIALLY THE SANGRES
AND SAN JUANS. FOR THIS REASON I HAVE INCREASED POPS OVER THESE
REGIONS DURING THIS TIME. NOTE THAT THE WINTER STORM WARNING FOR THE
SANGRES EXPIRES AT 00Z WED. IF THE MODELS ARE CORRECT...THIS WARNING
MAY NEED TO BE EXTENDED FOR THIS MTN RANGE BY ABOUT 6 HOURS OR SO.
AS FOR HIGH TEMPERATURES ON TUESDAY...I HAVE DECREASED THEM...WITH
TEMPS REACHING ABOUT 40F ALONG THE I-25 CORRIDOR REGION...AND
THESE VALUES MAY BE A BIT TOO HIGH IF THE MODEL SOUNDINGS ARE CORRECT.
OVER THE FAR E PLAINS AND SAN LUIS VALLEY...HIGHS SHOULD BE ABOUT
50F.
AS FOR THE REST OF THE FCST...WE WILL BE RETURNING TO A DRY PATTERN
AGAIN AS SW FLOW GRADUALLY RAMPS UP ONCE AGAIN. IF WE DO GET AS MUCH
PRECIP AS THE MODELS ARE INDICATING...THEN FIRE WX CONCERNS SHOULD
DROP SIGNIFICANTLY ACROSS THE FCST AREA. ATTM...THE WARMEST TEMPS
SHOULD BE DURING THE FRI-SAT TIME FRAME WITH A DRY PAC FRONT COMING
ACROSS THE REGION SAT NITE. TEMPS WILL COOL AGAIN ON SUNDAY.
THE NEXT CHANCE OF PRECIP...ACCORDING TO THE GFS WILL BE
MONDAY...BUT THE EC SIMULATION IS DRY FROM WED THROUGH NEXT WEEK.
/34
AVIATION...
STRONG N WINDS BEHIND A COLD FRONT WILL CONTINUE TO AFFECT KCOS AND KPUB
THROUGH THE NEXT 6-12 H. SUSTAINED WINDS FORM 30-40 KTS WITH HIGHER GUSTS
WILL BE POSSIBLE. WINDS WILL GRADUALLY DIMINISH THIS
EVE...HOWEVER...PRECIP IS EXPECTED TO BECOME MORE LIKELY
OVERNIGHT...WITH A GOOD CHANE OF SN AT KCOS AND A RAIN-SNOW MIX
POSSIBLE AT KPUB LATER TONIGHT. ALONG WITH GUSTY WINDS VIS IS
EXPECTED TO BE LOW OVERNIGHT IN PARTICULAR. KALS WILL ALSO SEE GUSTY
NE WINDS AND THE CHANCE OF SOME SHSN...BUT THE WORST CONDITIONS WILL
BE ALONG AND W OF I-25. 44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 6 PM MDT THIS EVENING FOR COZ084>086-089-
093.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM MDT TUESDAY
FOR COZ078-087-088.
WINTER STORM WARNING UNTIL 6 PM MDT TUESDAY FOR COZ072>075-079-
080.
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ069>071.
WINTER STORM WATCH FROM 9 PM MDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR COZ081-082-084.
&&
$$
31/23
AREA FORECAST DISCUSSION...CORRECTED
NWS CHARLESTON SC
308 PM EDT MON APR 2 2012
.SYNOPSIS...
A WEAK FRONT WILL DROP SOUTH INTO THE REGION TONIGHT AND LINGER
THROUGH TUESDAY BEFORE LIFTING NORTH TUESDAY NIGHT. ANOTHER COLD
FRONT WILL MOVE INTO THE AREA THURSDAY AND STALL INTO FRIDAY AS
WEAK WAVES OF LOW PRESSURE MOVE ALONG IT. COOLER HIGH PRESSURE
WILL RETURN NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
02/19Z MESOANALYSIS AND KLTX/KRAX REFLECTIVITY DATA SHOWED THE
BACKDOOR COLD FRONT EXTENDING FROM ROUGHLY CAPE FEAR ARCHING BACK
TO SOUTHERN PINES...LEXINGTON AND WINSTON SALEM. THE FRONT IS
STEADILY DROPPING SOUTH ALONG THE NORTH CAROLINA COAST AIDED BY
POST-FRONTAL ISALLOBARIC RISES OF 3-4MB/3HRS. A VERY WARM AND
SOMEWHAT HUMID AIRMASS IS IN PLACE ACROSS COASTAL SOUTH CAROLINA
AND GEORGIA AHEAD OF THE FRONT WITH TEMPERATURES SOARING WELL INTO
THE 80S TO NEAR 90 DEGREES. CURRENT AWIPS TIMING TOOLS AND RUC
DATA SUPPORT THE FRONT REACHING THE CHARLESTON METRO AREA BY VERY
LATE AFTERNOON AND THE SAVANNAH AREA BY MID-EVENING. THE PRIMARY
CONCERNS THIS EVENING IS THE POTENTIAL FOR ISOLATED SEVERE TSTMS.
THE AIRMASS ACROSS SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA
IS SLOWLY DESTABILIZING DESPITE STIFF DOWNSLOPE FLOW CONDITIONS.
EARLIER CAPPING NOTED ON RUC SOUNDINGS IS QUICKLY ERODING AS
TEMPERATURES REACH NEAR 90 DEGREES. SBCAPE IS APPROACHING 1500
J/KG WITH LIFTED INDICES AS LOW AS -5C. VISIBLE SATELLITE IMAGERY
ALREADY SHOW LINES OF CUMULUS BEGINNING TO BUILD ALONG VARIOUS
MESOSCALE BOUNDARIES SUCH AS THE MATURING LAKE BREEZE CIRCULATIONS
AROUND THE PERIPHERY OF LAKES MOULTRIE AND MARION AS WELL AS
DIFFERENTIAL HEATING BOUNDARIES CREATED FROM EARLIER CLOUD COVER
NORTH OF THE SOUTH SANTEE RIVER. THE VARIOUS HIGH RESOLUTION MODEL
PACKAGES REMAIN SIMILAR IN THE DEPICTION OF ISOLATED SHOWERS/TSTMS
INITIATING ALONG AND AHEAD OF THE SOUTHWARD MOVING BACKDOOR FRONT
OVER THE NEXT FEW HOURS AS WEAK H7-H5 PERTURBATIONS CROSS THE REGION
WHILE SLIDING DOWN THE EASTERN AXIS OF THE UPPER RIDGE. WILL
MAINTAIN SLIGHT CHANCE POPS FOR ALL ZONES THROUGH THE EVENING WITH
THE HIGHEST GRIDDED POPS WORKING SLOWLY NORTH-SOUTH WITH THE FRONT.
LOCALIZED HIGHER POPS MAY BE NEEDED LATER THIS AFTERNOON OR EVENING
ONCE CONVECTIVE TRENDS ARE ESTABLISHED.
DCAPES NEAR 1200 J/KG AND WBZ HEIGHTS NEAR 10 KFT WILL SUPPORT A
RISK FOR DAMAGING WINDS AND MARGINALLY SEVERE HAIL...BUT THE LACK
OF DEEP LAYERED SHEAR SUGGESTS ANY SUCH ACTIVITY WILL REMAIN
LOOSELY ORGANIZED AT BEST. WILL CONTINUE HIGHLIGHT ISOLATED SEVERE
TSTMS IN THE HAZARDOUS WEATHER OUTLOOK. ANY RISK FOR SEVERE TSTMS
SHOULD DIMINISH BY LATE EVENING AS INSTABILITY WANES AND UPPER
RIDGE BUILDS EAST.
CLOUD COVER WILL BE HEAVILY INFLUENCES BY THE AMOUNT OF CONVECTION
THAT FIRES. ALTHOUGH THERE WILL BE PERIODS OF MOSTLY CLOUDY SKIES
THIS EVENING WITH TSTMS...EXPECT PARTLY CLOUDY SKIES TO DOMINATE
OVERALL. LOWS WILL RANGE FROM THE LOWER 60S NORTH TO MID 60S
SOUTH.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
A RATHER CONVOLUTED PATTERN WILL CONTINUE FOR THE FORESEEABLE
FUTURE. THE UPPER RIDGE WILL BREAK DOWN ON TUESDAY ALLOWING
NUMEROUS SHORTWAVES TO MOVE THROUGH THE SOUTHEAST UNITED STATES
THROUGH THURSDAY. A STALLED FRONT DRAPED ACROSS THE AREA ON
TUESDAY WILL CREATE A SUBSTANTIAL TEMPERATURE GRADIENT. INTERIOR
SOUTHEAST GA WILL RISE INTO THE LOWER-MID 80S WHILE THE TRI-COUNTY
REGION IN SC WILL STAY IN THE UPPER 70S. ISOLATED TO SCATTERED
SHOWERS/STORMS ARE EXPECTED BUT COVERAGE SHOULD BE SOMEWHAT
LIMITED BY THE MID-LEVEL CAPPING.
THE FRONT WILL ERODE TUESDAY NIGHT BUT ANOTHER BACKDOOR FRONT WILL
BE KNOCKING ON THE NORTHERN DOOR ON WEDNESDAY. DEEP WEST-SOUTHWEST
FLOW AND SOME PRE-FRONTAL COMPRESSION WILL PUSH HIGH TEMPS WELL INTO
THE 80S. ISOLATED/SCATTERED CONVECTION IS EXPECTED BUT THE WESTERLY
SUBSIDENT FLOW SHOULD LIMIT COVERAGE YET AGAIN.
THE FRONT WILL MOVE INTO THE AREA ON THURSDAY AND SEVERAL RIPPLES OF
LOW PRESSURE WILL MOVE ALONG IT. A MORE FAVORABLE MID-LEVEL
ENVIRONMENT AND LOW-LEVEL INSTABILITY WILL SUPPORT BETTER COVERAGE
OF SHOWERS AND THUNDERSTORMS. THE COOLER AIRMASS COUPLED WITH
EXTENSIVE CLOUD COVER WILL KEEP TEMPS CLOSER TO 80 DEGREES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AT LEAST ONE AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA ALONG
THE LINGERING SURFACE FRONT...FINALLY PUSHING OFFSHORE FRIDAY NIGHT
IN ACCORDANCE WITH THE ATTENDANT UPPER TROUGH OF LOW PRESSURE. HIGH
PRESSURE WILL THEN BUILD FROM THE NORTH BRINGING A MUCH MORE
SEASONAL AIR MASS TO AREA FOR THE WEEKEND WITH A SLIGHT MODERATION
EARLY NEXT WEEK.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
VFR FOR THE NEXT 24 HOURS. BACKDOOR COLD FRONT IS MOVING STEADILY
SOUTH OUT OF NORTH CAROLINA AND WILL APPROACH KCHS BY LATE
AFTERNOON...POSSIBLY ACCOMPANIED BY ISOLATED TSTMS. GIVEN THE
LIMITED SPATIAL COVERAGE THAT IS EXPECTED...NO MENTION WILL BE
INCLUDED IN THE KCHS TAF. CB/S WILL BE CONTINUED. TSTMS SHOULD BE
SOUTH OF THE TERMINAL BY 00Z WITH LINGERING CLOUD COVER. FALLING
DEWPOINTS IN THE WAKE OF THE FRONT WILL PREVENT FOG FROM BECOMING
AN ISSUE OVERNIGHT.
THE FRONT WILL APPROACH THE KSAV TERMINAL BY MID-EVENING. STILL
COULD SEE ISOLATED TSTMS WITH THE FRONT...BUT GUIDANCE SUGGESTS
ANY FRONTAL ACTIVITY WILL REMAIN NORTH. TRENDS WILL BE MONITORED
HOWEVER...BUT NO MENTION OF TSTMS WILL BE INCLUDED GIVEN THE
LIMITED SPATIAL COVERAGE. THICKER CLOUD COVER WILL LINGER AT KSAV
OVERNIGHT...BUT CIGS WILL REMAIN VFR. LOOKS LIKE THERE WILL BE
ENOUGH WIND TO PRECLUDE SIGNIFICANT FOG DEVELOPMENT.
EXTENDED AVIATION OUTLOOK...OCCASIONAL REDUCED CIG/VSBY IN SCATTERED
SHRA/TSRA TUESDAY THROUGH FRIDAY NIGHT. MVFR/IFR CIGS/VSBYS POSSIBLE
DURING THE NIGHTTIME PERIODS IN LOW CEILINGS AND/OR FOG.
&&
.MARINE...
WINDS WILL TURN EAST/NORTHEAST BEHIND THE SOUTHWARD MOVING FRONT
THIS EVENING. THE HIGHEST WINDS LOOK TO OCCUR ACROSS THE SOUTH
CAROLINA WATERS WHERE A SURGE AS HIGH AS 15-20 KT CAN BE EXPECTED.
WINDS WILL BE SLIGHTLY LESS ACROSS THE GEORGIA WATERS. SEAS WILL
BUILD SLIGHTLY WITH THE FAVORABLE NORTHEAST FETCH...BUILDING TO
3-4 FT ALONG THE CHARLESTON COUNTY COASTAL WATERS WITH 2-3 FT
ELSEWHERE.
TUESDAY THROUGH SATURDAY...A COLD FRONT WILL STALL OVER THE WATERS
TUESDAY WHILE DISSIPATING. ANOTHER COLD FRONT WILL APPROACH FROM THE
NORTH WEDNESDAY/WEDNESDAY NIGHT AND PUSH INTO THE WATERS THURSDAY.
THE FRONT WILL THEN STALL INTO FRIDAY WHILE AT LEAST ONE AREA OF LOW
PRESSURE MOVES EAST ALONG IT...FINALLY PUSHING OFFSHORE FRIDAY
NIGHT. HIGH PRESSURE WILL THEN BUILD FROM THE NORTH SATURDAY.
CONDITIONS SHOULD REMAIN BELOW ADVISORY LEVELS THROUGH THE PERIOD
UNTIL SATURDAY WHEN INCREASING NE WINDS PUSH SEAS TO AT LEAST 6 FT.
&&
.CLIMATE...
AS OF 3 PM...THE RECORD AT THE CHARLESTON AIRPORT HAS BEEN TIED AT
90 DEGREES. THERE IS A CHANCE FOR EVEN WARMER CONDITIONS PRIOR TO
SUNSET.
RECORD HIGHS FOR TODAY...APRIL 2ND...
CHARLESTON AIRPORT..... 90 SET IN 2006
DOWNTOWN CHARLESTON.... 89 SET IN 1910
SAVANNAH AIRPORT....... 91 SET IN 1940
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...
MARINE... /JRL
CLIMATE...
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS PEACHTREE CITY GA
142 PM EDT MON APR 2 2012
.UPDATE...
/ISSUED AT 1146 AM EDT MON APR 2 2012/
HAVE UPDATED THE FORECAST THROUGHOUT THE MORNING TO INCREASE CLOUD
COVERAGE ACROSS THE SOUTHWEST PART OF THE CWA. HAVE ALSO SEEN
DEVELOPMENT ACROSS NORTH GEORGIA. OTHERWISE...ONLY MINOR TWEAKS TO
THE FORECAST.
BOTH HRRR AND LOCAL WRF SUGGEST CONVECTION ALONG THE EASTERN EDGE
OF THE CWA SO CONTINUED CURRENT POP FORECAST WHICH REFLECTS THIS.
ALSO AGREE WITH OVERALL THINKING THAT SOME OF THE STORMS COULD
BECOME STRONG. SPC HAS THE AREA IN A SEE TEXT WITH 5 PERCENT FOR
WIND AND HAIL.
11
&&
.PREV DISCUSSION...
SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
/ISSUED 435 AM EDT MON APR 2 2012/
RIDGE ALOFT CONTINUES OVER GEORGIA TODAY WITH PERSISTENT ABOVE
AVERAGE TEMPERATURES AND DRY CONDITIONS. A FRONT MOVING SOUTHWARD
THROUGH THE MID ATLANTIC STATES TODAY SHOULD MOVE INTO THE
SAVANNAH RIVER VALLEY BY TONIGHT. SOME UNCERTAINTY BETWEEN THE
MODELS ON HOW FAR WESTWARD THE FRONT WILL PUSH INTO THE CWA.
HOWEVER...EASTERLY WINDS ARE SHOWN FOR AHN OVERNIGHT AND INTO THE
EARLY MORNING OF TUESDAY. SO HAVE INCLUDED A SLIGHT CHANCE OF
THUNDERSTORMS FOR THE EXTREME NORTHEAST CORNER THIS
AFTERNOON...AND A SLIGHT CHANCE TONIGHT ALONG MUCH OF THE EASTERN
SIDE OF THE CWA. MEANWHILE...A SHORT WAVE FROM THE NORTHWEST GULF
MOVES INTO THE LOWER MISSISSIPPI VALLEY TONIGHT AND INTO THE OHIO
VALLEY ON TUESDAY. THIS WILL BRING A CHANCE OF THUNDERSTORMS INTO
THE REMAINDER OF THE CWA TUESDAY AND TUESDAY NIGHT. HAVE TAKEN A
COMPROMISE ON THE MAV/MET TEMPERATURES. WITH THE POSSIBILITY OF A
BACKDOOR FRONT AFFECTING THE EASTERN COUNTIES...HAVE TRENDED
TOWARD THE COOLER TEMPERATURES TUESDAY AND TUESDAY NIGHT IN THAT
AREA.
41
LONG TERM /WEDNESDAY THROUGH SUNDAY/...
/ISSUED 435 AM EDT MON APR 2 2012/
EXTENDED PROGS APPEAR TO BE COMING INTO SOMEWHAT BETTER AGREEMENT
WITH THE UPPER RIDGE BEGINNING TO FLATTEN OUT OVER THE SOUTHEAST
U.S. WEDNESDAY/THURSDAY AS AN UPPER TROUGH/CLOSED LOW COMPLEX MOVES
EAST FROM THE PLAINS. ECMWF CONTINUE TO BE A TAD SLOWER (AND
FARTHER SOUTH) WITH THIS SYSTEM MOVING EASTWARD. BY 12Z FRIDAY GFS
TAKES THE LOW ACROSS TENNESSEE AND INTO THE CAROLINAS BY THE END
OF THE DAY...WHILE THE ECMWF SHOWS THE LOW OVER ALABAMA MOVING
INTO EAST CENTRAL GEORGIA DURING THIS TIME PERIOD. BOTH SHOW THIS
SYSTEM EAST OF OUR AREA BY SATURDAY WITH A HIGH PRESSURE RIDGE
BEGINNING TO BUILD BACK ACROSS THE SOUTHEAST STATES. NONETHELESS
WILL CONTINUE PREVIOUS FORECAST TREND WITH CHANCE TO GOOD CHANCE
POPS MUCH OF THE AREA WEDNESDAY INTO FRIDAY...WITH SLIGHT CHANCE
POPS FRIDAY NIGHT...ENDING ALL PRECIP BY SATURDAY.
49
CLIMATE...
RECORDS FOR 04-02
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 89 1940 46 1915 63 1908 28 1924
KATL 88 1940 42 1915 63 1979 25 1881
1905
KCSG 86 1999 54 1993 67 2000 34 1992
1978 1961
KMCN 88 1940 48 1915 63 2000 32 1992
1935
RECORDS FOR 04-03
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 88 1934 47 1987 62 2007 26 1992
1974
KATL 86 1946 39 1987 65 1974 29 1992
1945
KCSG 88 1999 52 1987 70 1977 32 1962
1957
KMCN 89 1957 51 1901 69 1977 31 1993
1992
1971
&&
.AVIATION...
18Z UPDATE...
SCT MID LEVEL CU-TCU AND WNW WINDS GUSTING TO AROUND 20KTS WILL
PREVAIL THIS AFTERNOON. MODELS AGREE ON A BACKDOOR FRONT SAGGING
INTO ATLANTA AREA BY 12-15Z TUE. AS A RESULT...EXPECT SCT025 TO
ADVECT INTO ATL BY 12Z...THEN GO BKN040 BY 15Z WITH SOME DAYTIME
HEATING AND THE FRONT IN THE AREA. WINDS SWING MORE NW BY 12Z
TUE...THEN OVER NE BY 15Z TUE BEHIND THE BACKDOOR FRONT. THE FRONT
RETREATS BACK NORTH BY 18Z TUE...RESULTING IN WINDS SWINGING BACK NW
BY 18Z. SPEEDS DIMINISHING BY 00Z THIS EVENING TO 5-7KTS AND EXPECT
MAYBE 6-8KTS ON TUE. CURRENT THINKING IS THE TSTM THREAT WILL BE
MAINLY NORTH AND EAST OF ATL ON TUE...BUT WILL MENTION PROB30 19-23Z
AT AHN FOR NOW.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF MID LEVEL CIGS AND WINDS SWINGING NE
EARLY TUE MORNING. HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 86 59 81 58 / 10 20 30 30
ATLANTA 84 65 84 63 / 5 10 20 30
BLAIRSVILLE 82 57 80 54 / 20 20 30 40
CARTERSVILLE 84 61 85 59 / 10 10 20 40
COLUMBUS 86 65 86 62 / 0 10 20 20
GAINESVILLE 85 61 81 60 / 10 20 30 40
MACON 87 62 86 61 / 0 10 20 20
ROME 85 58 86 60 / 10 10 20 40
PEACHTREE CITY 84 61 85 58 / 0 10 20 20
VIDALIA 85 64 84 65 / 10 10 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
326 PM EDT MON APR 2 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
CHANCES OF MORE THUNDERSTORMS LATE TONIGHT THROUGH TUESDAY EVENING
AND WARMER TEMPERATURES FOR TUESDAY WILL BE THE MAIN SHORT TERM
CONCERNS.
FOR TONIGHT...MOSTLY CLEAR SKIES EXPECTED ACROSS MUCH OF THE AREA
THIS EVENING WITH SOME INCREASING IN MID LEVEL CLOUDINESS WITH MID
LEVEL FRONTAL ZONE EXTENDING FROM NORTHERN LOWER MICHIGAN INTO
NORTHWEST OHIO. SOME LOWER BASED CLOUDS HAVE ALSO BEEN DEVELOPING
ALONG A LINE FROM NORTHWEST ILLINOIS INTO WEST CENTRAL ILLINOIS
WHICH SEEM TO CORRELATE WELL WITH RUC 900/850 HPA LAYER
FRONTOGENESIS FIELDS THIS AFTERNOON. THIS AXIS WILL GRADUALLY SHIFT
EASTWARD LATER THIS EVENING WITH INCREASE IN CLOUDINESS LATER THIS
EVENING FROM WEST TO EAST. WATER VAPOR IMAGERY NOT DEPICTING ANY
IMMEDIATE SHORT WAVES OF CONSEQUENCE FOR THE LOCAL AREA TONIGHT BUT
CONSISTENT SIGNAL OVER THE PAST FEW DAYS HAS BEEN FOR DEVELOPMENT OF
30 KNOT SOUTHWESTERLY LOW LEVEL JET NOSING INTO FAR NORTH CENTRAL
INDIANA/SOUTHERN LOWER MICHIGAN...PERHAPS A BIT MORE DELAYED IN THE
LAST FEW MODEL CYCLES. SEE LITTLE TO DEVIATE FROM PREVIOUS FORECAST
FOR TONIGHT AT THIS POINT WITH MID CHANCE POPS NORTH AND LOW CHANCE
POPS SOUTH...WITH THE HIGHER TSRA POPS LINING UP BETTER WITH 850 HPA
MOISTURE CONVERGENCE ACROSS SOUTHERN LOWER MICHIGAN AND FAR NORTHERN
INDIANA AFTER 06Z AS STRONG LOW LEVEL THETAE ADVECTION SPREADS FROM
WEST TO EAST.
ELEVATED MIXED LAYER ADVECTING INTO THE AREA LATER TONIGHT DOES POSE
SOME UNCERTAINTY WITH MAGNITUDE OF ELEVATED INSTABILITY. TAKING A
900 HPA BASED PARCEL FROM 12Z NAM BUFFER SOUNDINGS YIELDS BETWEEN
1000-1500 J/KG OF ELEVATED CAPE AFTER 06Z. 12Z GFS BUFFER SOUNDINGS
REMAIN A BIT MORE PRONOUNCED WITH THIS ELEVATED MIXED LAYER AND MID
LEVEL WARM LAYER THAT WOULD RESULT IN LESSER INSTABILITY THAN
INDICATED BY THE NAM. EFFECTIVE SHEAR FOR THESE ELEVATED PARCELS
SHOULD DECREASE STEADILY OVERNIGHT HOWEVER WHICH SHOULD TEND TO
LIMIT POTENTIAL FOR CONVECTIVE ORGANIZATION/SEVERE THREAT. PREVIOUS
FORECAST IDEA OF ISOLATED LARGE HAIL THREAT STILL SEEMS IN
ORDER...BUT SHIFTED A BIT LATER AFTER 06Z BASED ON TREND OF SLIGHTLY
SLOWER MODEL DEPICTION OF LOW LEVEL JET AXIS SHIFTING INTO THE AREA.
LINGERING ELEVATED CONVECTION SHOULD DIMINISH EARLY TUESDAY AS LOW
LEVEL JET VEERS AND MOISTURE CONVERGENCE WEAKENS. A CONVECTIVELY
ENHANCED VORT MAX ACROSS EASTERN TEXAS THIS AFTERNOON SHOULD LIFT
NORTHWARD INTO MID MS RVR VALLEY LATE TUESDAY AFTERNOON...BUT
OVERALL CONVECTIVE THREAT APPEARS TO BE LOW FOR LATE
MORNING/AFTERNOON HOURS WITH FCST SOUNDINGS SUGGEST SOME CAPPING
CONCERNS. THUS...HAVE LOWERED AFTERNOON TSRA POPS AND MAINTAINED
HIGHEST CHANCE ACROSS THE WEST WHERE FORCING FROM THIS VORT MAX WILL
LIKELY BE MAXIMIZED. BEST CHANCE OF SHOWERS AND THUNDERSTORMS LOOKS
TO BE FOR THE EVENING HOURS AS ANOTHER SOUTHERN CANADIAN UPPER LEVEL
SHORT WAVE PROVIDES IMPETUS FOR SFC LOW/FRONT TO SHIFT SOUTHEAST
THROUGH THE AREA. LOW LEVEL FRONTOGENESIS ALSO TO STRENGTHEN AS
STRONGER NORTHERLY FLOW INTERACTS WITH THIS BOUNDARY DURING THE
EARLY EVENING. SEVERE POTENTIAL APPEARS TO BE RELATIVELY LOW AT THIS
TIME DUE TO CONTINUED MARGINAL TO WEAK SHEAR PROFILES. HAVE ALSO
INCREASED MAX TEMPS FOR TUESDAY WITH CONFIDENCE INCREASING THAT MOST
IF NOT ALL OF FORECAST AREA WILL GET INTO WARM SECTOR AGAIN BEFORE
FRONTAL PASSAGE IN THE FAR NORTHWEST MID TO LATE AFTERNOON. RECORD
HIGHS IN THE UPPER 70S FOR FORT WAYNE AND SOUTH BEND COULD ONCE
AGAIN BE AT RISK OF BEING BROKEN.
&&
.LONG TERM...
WEDNESDAY THROUGH MONDAY
MAIN FOCUS OF LONG TERM PERIOD IS COOLER TEMPERATURES AND FROST
POTENTIAL WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.
LONG TERM PERIOD BEGINS WEDNESDAY WITH SURFACE HIGH PRESSURE
CENTERED NORTHWEST OF THE REGION BUILDING SOUTHEASTWARD INTO THE
LOWER GREAT LAKES...AND A FRONTAL BOUNDARY SITUATED ALONG THE OHIO
RIVER VALLEY. CUTOFF UPPER LOW OVER PANHANDLE REGION WILL SLOWLY
TRACK EASTWARD TOWARDS MID MISSISSIPPI VALLEY. DRY CONDITIONS ARE
EXPECTED WEDNESDAY AND WEDNESDAY NIGHT. KEPT PATCHY FROST MENTION IN
THE NE PORTION OF THE FA...BUT INCREASED GRADIENT OF LOW TEMPS FROM
NE TO SW AS CUTOFF LOW AND AFOREMENTIONED BOUNDARY PASS JUST SOUTH
OF THE FA.
CUTOFF LOW WILL CONTINUE EASTWARD INTO LOWER OHIO VALLEY ON
THURSDAY. 12Z GFS INDICATED PRECIP POTENTIAL ACROSS THE FAR SW
PORTIONS OF THE FA AS FRONTAL BOUNDARY SLIDES EASTWARD.
HOWEVER...CONFIDENCE IS LOW AS 12Z GFS RUN OPENS LOW INTO POSITIVELY
TILTED WAVE QUICKER AND DIVES MORE SOUTHEASTERLY THAN PREVIOUS
RUN...MORE IN LINE WITH 00Z ECMWF. THURSDAY NIGHT LOOKS TO BE THE
COOLEST NIGHT IN THE EXTENDED PERIOD AS SFC RIDGE AXIS SLIDES
OVERHEAD. KEPT THE AREAS OF FROST MENTION IN ROUGHLY THE SAME AREAS
AS PREVIOUS FCST. WILL CONTINUE TO MONITOR THIS PD OVER THE NEXT FEW
FORECASTS WITH POSSIBLE NEED FOR HEADLINES...WITH LOWS NEARING 32-33
ACROSS MUCH OF THE FA.
SFC RIDGE WILL CONTINUE TO SLIDE EAST ACROSS GREAT LAKES AS UPPER
RIDGE AXIS MOVES ACROSS THE REGION. FRIDAY WILL AGAIN BE COOLER WITH
EASTERLY WINDS AND SLOWLY MODERATING AIRMASS. KEPT PATCHY FROST
MENTION IN FCST FRI NIGHT AS RIDGE AXIS WILL BE JUST EAST OF FA AND
LIGHTER WINDS. SATURDAY WILL BE CONSIDERABLY WARM WITH UPPER RIDGE
OVER THE AREA AND SFC HIGH EAST...RESULTING IN SOUTHERLY WINDS AND
WAA. RAISED TEMPS A FEW DEGREES FROM PREVIOUS FCST/ALLBLEND.
NEXT PRECIP CHANCES RETURN SAT NIGHT/SUN AS DEEPENING SFC
LOW/EJECTING WRN CONUS TROF ENERGY ACROSS NRN TIER BRINGS A COLD
FRONT THROUGH THE REGION. KEPT POPS CHANCE/SLIGHT CHANCE AS BEST
FORCING REMAINS NORTH AND BEST MOISTURE/INSTABILITY REMAINS SOUTH.
&&
.AVIATION...
18Z TAFS...MAIN AVIATION FORECAST CONCERN WILL BE POTENTIAL OF
THUNDERSTORMS LATE TONIGHT INTO TUESDAY. IN THE MEANTIME...QUIET
AVIATION CONDITIONS IN STORE WITH EASTERLY WINDS CONTINUING TO THE
NORTH OF THE SFC BOUNDARY WHICH TRACKED ACROSS THE AREA YESTERDAY.
MIXING HEIGHTS NOT PARTICULARLY DEEP...BUT GUSTS TO AROUND 20
KNOTS ARE EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE
AFTERNOON. FOR TONIGHT...A LOW LEVEL JET ACROSS THE MID MS VALLEY
IS EXPECTED TO SHIFT INTO THE SOUTHERN GREAT LAKES REGION
RESULTING IN STRENGTHENING WARM AIR ADVECTION. THIS FORCING MAY BE
ENOUGH FOR SCATTERED THUNDERSTORM DEVELOPMENT
OVERNIGHT...ESPECIALLY AFTER 06Z. CONFIDENCE IS LOW IN THIS
SCENARIO ESPECIALLY AT KFWA WHICH MAY END UP JUST SOUTH OF THIS
LOW LEVEL JET AXIS. DID ADD VCTS MENTION AT KSBN DURING THIS TIME
PERIOD WITH THE EXPECTATION OF AT LEAST SCATTERED CONVECTION IN
THE AREA...BUT LOW ENOUGH CONFIDENCE AT THIS POINT TO NOT INCLUDE
TS IN THE FORECAST FOR TERMINAL. LULL IN PRECIP IS POSSIBLE
TUESDAY LATE MORNING INTO AFTERNOON WITH LITTLE FORCING TO FOCUS
ADDITIONAL STORMS AND HAVE KEPT FORECAST DRY THROUGH END OF THE
PERIOD. SFC WINDS TO VEER MORE SOUTHERLY AFTER 14Z AS SFC LOW
PRESSURE TRACKS INTO EASTERN IOWA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...MARSILI
LONG TERM...NG
AVIATION...MARSILI
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
141 PM EDT MON APR 2 2012
.AVIATION...
18Z TAFS...MAIN AVIATION FORECAST CONCERN WILL BE POTENTIAL OF
THUNDERSTORMS LATE TONIGHT INTO TUESDAY. IN THE MEANTIME...QUIET
AVIATION CONDITIONS IN STORE WITH EASTERLY WINDS CONTINUING TO THE
NORTH OF THE SFC BOUNDARY WHICH TRACKED ACROSS THE AREA YESTERDAY.
MIXING HEIGHTS NOT PARTICULARLY DEEP...BUT GUSTS TO AROUND 20
KNOTS ARE EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE
AFTERNOON. FOR TONIGHT...A LOW LEVEL JET ACROSS THE MID MS VALLEY
IS EXPECTED TO SHIFT INTO THE SOUTHERN GREAT LAKES REGION
RESULTING IN STRENGTHENING WARM AIR ADVECTION. THIS FORCING MAY BE
ENOUGH FOR SCATTERED THUNDERSTORM DEVELOPMENT
OVERNIGHT...ESPECIALLY AFTER 06Z. CONFIDENCE IS LOW IN THIS
SCENARIO ESPECIALLY AT KFWA WHICH MAY END UP JUST SOUTH OF THIS
LOW LEVEL JET AXIS. DID ADD VCTS MENTION AT KSBN DURING THIS TIME
PERIOD WITH THE EXPECTATION OF AT LEAST SCATTERED CONVECTION IN
THE AREA...BUT LOW ENOUGH CONFIDENCE AT THIS POINT TO NOT INCLUDE
TS IN THE FORECAST FOR TERMINAL. LULL IN PRECIP IS POSSIBLE
TUESDAY LATE MORNING INTO AFTERNOON WITH LITTLE FORCING TO FOCUS
ADDITIONAL STORMS AND HAVE KEPT FORECAST DRY THROUGH END OF THE
PERIOD. SFC WINDS TO VEER MORE SOUTHERLY AFTER 14Z AS SFC LOW
PRESSURE TRACKS INTO EASTERN IOWA.
&&
.PREV DISCUSSION... /ISSUED 1129 AM EDT MON APR 2 2012/
UPDATE...
QUIET WEATHER FOR THIS AFTERNOON WITH MAIN FOCUS CONTINUING ON
TEMPERATURE TRENDS. TEMPERATURES HAVE BEEN VERY SLOW TO RISE THIS
MORNING DUE IN LARGE PART TO A VERY STRONG MORNING INVERSION NOTED
PER AMDAR SOUNDINGS WHICH WERE ONLY MIXED TO BETWEEN 1500-2000 FT
LATE THIS MORNING. SOME SUBTLE DIFFERENCES NOTED IN MIXED LAYER
DEPTHS BETWEEN NAM/RUC FOR THIS AFTERNOON WITH NAM SUGGESTING A
SLIGHTLY DEEPER MIXED LAYER THAT WOULD ALLOW FOR AFTERNOON HIGHS
CLOSE TO THOSE CURRENTLY FORECASTED. THESE HIGHS MAY REPRESENT A
BEST CASE SCENARIO IN TERMS OF MAX HEATING POTENTIAL
TODAY...ESPECIALLY IF MIXING HEIGHTS ARE A BIT MORE SHALLOW LIKE
THE RUC WOULD SUGGEST. WILL HOLD OFF ON ANY ADJUSTMENTS TO MAX
TEMPS AT THIS TIME AND JUST REFINE DIURNAL CURVE TO PUT MOST OF
TEMPERATURE INCREASE IN THE 17Z TO 20Z PERIOD DUE TO EFFECTS FROM
THE INVERSION. MORE SOLID STRATOCU DECK ACROSS NORTHWEST OHIO
SHOULD CONTINUE TO ERODE THROUGH THE AFTERNOON AND NOT PLAY A
MAJOR ROLE IN LIMITING AFTERNOON TEMP RISES. UPDATED FORECAST SENT
EARLIER THIS MORNING MAINLY TO REFINE SKY COVER TRENDS.
&&
PREV DISCUSSION... /ISSUED 702 AM EDT MON APR 2 2012/
AVIATION.../12Z TAFS/
PATCHY STRATO CU WITH MVFR CIGS OVER NRN INDIANA EARLY THIS
MORNING... AND A LITTLE MORE WIDESPREAD UPSTREAM OVER NRN OH.
EXPECT WITH DIURNAL HEATING/MIXING THESE CLOUDS WILL DIMINISH
AFTER SUNRISE WITH JUST PATCHY ALTO CU OR CIRRUS THIS AFTN/EVE.
WK LOW WILL MOVE TOWARD THE AREA TONIGHT WITH LLJ TRANSPORTING
INCRSG MOISTURE AND RESULTANT ELEVATED INSTABILITY INTO THE AREA
LATE TONIGHT PSBLY LEADING TO SCT TS...THUS ADDED CB WITH LOW VFR
CIGS AT BOTH TERMINALS TOWARD THE END OF THE PERIOD. GRADIENT
BETWEEN SFC RIDGE MOVG TO LWR GRTLKS AND SF LOW/WARM FRONT MOVG
INTO THE MS VALLEY WILL RESULT IN FAIRLY STRONG ESE SFC WINDS AT
THE TERMINALS TODAY WITH GUSTS AROUND 22KT.
PREV DISCUSSION... /ISSUED 457 AM EDT MON APR 2 2012/
SHORT TERM.../TODAY-TUE NGT/
SHRTWV DROPPING SSE INTO MID ATLANTIC THIS MORNING HAS PUSHED A
BACKDOOR CDFNT THROUGH OUR AREA TO THE LOWER OH VALLEY. MID LEVEL
CONVERGENT FLOW WAS RESULTING IN A COUPLE OF BANDS OF SCT HIGH BASED
SHOWERS BEHIND THE FRONT... ONE OVER SWRN MI AND ANOTHER OVER ERN
INDIANA/SWRN OH. RIDGE ALOFT BUILDING EASTWARD THIS MORNING SHOULD
DIMINISH THIS ACTIVITY OVER THE NEXT 3-6HRS SO LEFT OUT OF TODAYS
FCST WITH SHOWERS FCST TO END BY 12Z IN OUR AREA. RIDGE EXTENDING
SOUTH FROM HUDSON BAY TO THE GRTLKS BEHIND THIS CDFNT SHOULD
PROVIDE FAIR WX TODAY. CDFNT TRANSITIONS TO A STNRY FRONT FROM SRN
IL TO LOW PRESSURE CENTERED OVER NEB/KS. THIS LOW ASSOCIATED WITH
CLOSING OFF UPR SYSTEM OVER AZ/NM AND SHOULD GRADUALLY WEAKEN
TODAY. NRN STREAM SHRTWV MOVG EAST ACROSS MT/SASK WILL RESULT IN
EASTWARD MOVEMENT OF THE WKNG SFC LOW THROUGH THE SHORT TERM
PERIOD. THIS WILL RESULT IN A RATHER TIGHT SFC PRESSURE GRADIENT
ACROSS OUR CWA WITH E-SE SFC WINDS OF 10-20MPH. THIS SHOULD
PROVIDE DECENT MIXING AND SUSPECT MODELS ARE A LITTLE TOO SHALLOW
WITH THE BOUNDARY LAYER THIS AFTN...THUS STAYED CLOSE TO PREVIOUS
FCST HIGHS FOR TODAY WHICH WERE GENERALLY AT OR A BIT ABOVE
LATEST MOS.
AS LOW MOVES CONTS SLOWLY EAST ACROSS IA TONIGHT STNRY FRONT WILL
LIFT SLOWLY NE INTO IL AS A WARM FRONT. H85 THETA-E ADVECTION NE
OF THE SFC WARM FRONT SPREADING INTO OUR AREA ALONG WITH ELEVATED
INSTABILITY IS EXPECTED TO RESULT IN SCT TSTMS DVLPG OVERNIGHT.
GIVEN EXPECTATION OF INCRSG CLOUDS AND SOME GRADIENT WINDS TONIGHT
LEANED TOWARD WARMER END OF GUIDANCE FOR LOWS WHICH ARE FCST TO
RANGE FROM THE U30S NE TO THE L50S SW.
WK LOW IS FCST SIMILARLY BY 00Z MODELS TO TRACK EASTWARD ACROSS OUR
CWA ON TUESDAY. THIS IS SLOWER THAN INDICATED BY EARLIER
NAM/GFS/SREF RUNS... ALLOWING WARMER/MORE MOIST AIRMASS TO SPREAD
INTO THE AREA DURING THE DAY TUE. DESTABILIZATION IS LIKELY WITH
CAPE EXPECTED TO INCREASE INTO THE 1500-2500J/KG RANGE. MOIST
CONVERGENCE ALONG THE WARM/CDFNT ASSOCIATED WITH THE LOW MOVG
THROUGH OUR AREA MAY PROVIDE SUFFICIENT FORCING FOR SCT TSTM
DEVELOPMENT. HWVR... WARM MID LEVEL TEMPS WILL RESULT IN A
CAPPING INVERSION WHICH MAY NOT BREAK UNTIL LATE AFTN OR EVE.
0-6KM SHEAR FCST TO BE WK DURING THIS PERIOD, BUT GIVEN POTENTIAL
DVLPG INSTABILITY, ISOLATED SVR STORMS ARE PSBL. WITH THE SLOWING
TREND OF MODELS TO MOVE LOW/CDFNT THROUGH THE AREA... 00Z RUNS
SUGGESTING HIGH TEMPS COULD BE 5-10F WARMER THAN OUR PREVIOUS
FCST... FOR NOW UTILIZED A BLEND OF 00Z MODEL CONSENSUS AND
PREVIOUS FCST TO TREND HIGHS UP ABOUT 3F. THE MODELS SLOWER TREND
ON MOVING LOW THROUGH THE AREA MAY ALSO IMPACT LOWS TUE NIGHT WITH
COLDER AIR PRBLY SLOWER TO ARRIVE IN OUR AREA. AGAIN JUST TRENDED
UP A FEW DEGREES ATTM.
&&
LONG TERM...
WEDNESDAY THROUGH SUNDAY...THE MAIN CHALLENGES THIS PERIOD INCLUDE
THE CHANCES FOR FROST WEDNESDAY NIGHT THROUGH FRIDAY NIGHT AND THE
POSSIBILITY OF THUNDER OVER THE WEEKEND. FOR THIS PACKAGE...FAVORED
THE ECMWF AND CANADIAN GEM ENSEMBLES. AN UPPER LOW EMBEDDED IN A
RIDGE WILL DRIFT EAST AND WILL PASS SOUTH OF THE FORECAST AREA. KEPT
CONDITIONS DRY THROUGH SATURDAY. HAVE TRENDED TEMPERATURES DOWN MOST
PERIODS THROUGH FRIDAY NIGHT AS A CHILLY NORTH EAST TO EAST FETCH
PERSISTS OVER EASTERN CANADA INTO THE WESTERN GREAT LAKES REGION.
HAVE ADJUSTED THE TIMING OF FROST IN THE GRIDS AND HAZARDOUS WEATHER
OUTLOOK TO MATCH THIS SCENARIO...WITH THE BEST CHANCE FOR FROST
THURSDAY NIGHT. GUT FEELING IS HIGHS FRIDAY ARE STILL TOO WARM...AND
MAY NEED TO BE LOWERED 3 TO 6 MORE DEGREES. THE GFS MEX MOS HIGH OF
63F AT FT WAYNE DEFINITELY LOOKS TOO WARM. CORRESPONDINGLY...GFS MEX
DIURNAL SPREADS OF 30 AND 33 RESPECTIVELY FOR FRIDAY AND SATURDAY
ALSO LOOK TOO LARGE. THE CANADIAN GEM ENSEMBLES EPS GRAMS LOOK GOOD
WITH A TIGHT CLUSTER OF MEMBERS WITH LOWS JUST ABOVE FREEZING
THURSDAY NIGHT AND HIGHS FRIDAY AOB 53 AT FT WAYNE. OTHERWISE...KEPT
A CHANCE FOR THUNDER SATURDAY NIGHT INTO SUNDAY. MOISTURE IS LIMITED
AND FORCING APPEARS MARGINAL AS THE SURFACE LOW TRACKS FROM THE
UPPER MIDWEST INTO SOUTHERN CANADA DURING THIS PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...MARSILI
UPDATE...MARSILI
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
346 PM EDT MON APR 2 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH AND DROP TEMPERATURES
TO NEAR FREEZING ACROSS PORTIONS OF THE AREA TONIGHT. A FRONTAL
BOUNDARY WILL APPROACH FROM THE SOUTHWEST TOMORROW, BRINGING
WARMER TEMPERATURES WITH THE CHANCE OF SHOWERS AND THUNDERSTORMS
TOMORROW NIGHT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE LATEST RUC 300MB ANALYSIS INDICATES RIDGING AND WEAK WINDS
ALOFT BEGINNING TO BUILD INTO THE OHIO VALLEY FROM THE WEST AS A
140KT JET SLIDES EAST OF THE AREA INTO THE NORTHEAST. A SWATH OF
DRY AIR IS EVIDENT SLIDING SOUTHEASTWARD ACROSS WESTERN PA. AT THE
SURFACE, A 1025MB HIGH IS CENTERED OVER THE HUDSON BAY WITH HIGH
PRESSURE EXTENDING SOUTHEASTWARD INTO THE GREAT LAKES.
TONIGHT...THERE IS OPERATIONAL MODEL AGREEMENT THAT THE RIDGE
WILL EDGE EASTWARD AND BECOME CENTERED OVER THE GREAT LAKES. A
NORTHWESTERLY FLOW ALOFT WILL ALLOW FOR HIGH PRESSURE TO SLIDE
FURTHER SOUTHWARD INTO THE UPPER OHIO VALLEY, BECOMING CENTERED
NORTHEAST OF PITTSBURGH BY 12Z TUESDAY. THUS, CLEAR SKIES CAN BE
EXPECTED UNTIL NEAR DAWN WHEN CIRRUS BEGINS TO SPILL INTO THE AREA
FROM THE WEST.
FOR TEMPS, A MAV/MET BLEND SEEMED REASONABLE WITH THE BEST
RADIATIONAL COOLING TONIGHT CLOSEST TO THE SURFACE HIGH
NORTHEAST OF PITTSBURGH. A FREEZE WARNING HAS BEEN ISSUED FOR
AREAS NORTHEAST OF PITTSBURGH AND ACROSS THE EASTERN RIDGES.
PATCHY FROST IS ALSO FORECAST FOR THE PITTSBURGH METRO.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
THERE IS NAM/ECMWF AGREEMENT THAT A MID-LEVEL SHORT WAVE ALONG WITH A
WEAK SURFACE LOW WILL MOVE FROM THE MISSOURI VALLEY ACROSS THE OHIO
VALLEY ON TUESDAY. THIS WILL ALLOW FOR A WARM FRONT TO APPROACH FROM
THE SOUTHWEST DURING THE DAY. MODELS INDICATE THE SHORT WAVE
DE-AMPLIFYING AND THE SURFACE LOW BECOMING POORLY DEFINED AS THE
PAIR MOVE INTO THE AREA IN THE 00Z-06Z WEDNESDAY TIME FRAME. WITH
THIS IN MIND, HAVE SLOWED POPS AND WILL KEEP THE FORECAST DRY
UNTIL 21Z WHEN WEAK ELEVATED INSTABILITY BEGINS TO MOVE INTO
EASTERN OHIO AND BRINGS THE POSSIBILITY OF THUNDERSTORMS.
LINGERING WAVE ENERGY WILL PUSH ACROSS THE AREA AS THE FRONTAL
BOUNDARY BECOMES STATIONARY. THUS, THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS WILL BE TUESDAY NIGHT.
DESPITE THE FRONTAL BOUNDARY BEING SLOW TO APPROACH FROM THE
SOUTHWEST, WARM AIR ADVECTION ALOFT WILL ALLOW FOR 850 TEMPS TO
WARM INTO THE 10-14C RANGE BY 00Z WEDNESDAY. HIGHS TUESDAY ARE
FORECAST AT 10 DEGREES ABOVE NORMAL. TUESDAY NIGHT TEMPS WILL BE SLOW
TO DECREASE AS THE BOUNDARY MOVES NORTH INTO THE AREA. LOWS WILL
RANGE FROM THE LOWER 50S ACROSS NORTH-CENTRAL WV TO NEAR 40 NORTH
OF THE I-80 CORRIDOR.
WEDNESDAY THROUGH THURSDAY...THE FRONTAL BOUNDARY WILL BEGIN TO SAG
SOUTHWARD ON WEDNESDAY, WITH THE CHANCE OF SHOWERS ENDING ACROSS
THE SOUTH BY THE AFTERNOON. HIGH PRESSURE WILL THEN BUILD IN FROM
THE NORTH WITH A DRY FORECAST THROUGH THURSDAY. TEMPERATURES
THROUGH THIS PERIOD WILL BE NEAR SEASONAL VALUES WITH THE
POTENTIAL FOR ANOTHER FREEZE NORTHEAST OF PITTSBURGH ON WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS HIGH PRESSURE
OVER THE EASTERN U.S. PROVIDING DRY CONDITIONS ACROSS THE UPPER OHIO
VALLEY INTO DAYTIME SUNDAY. CONSENSUS OF MODELS THEN SHOW THE UPPER
LEVEL JET STREAM PATTERN BECOMING MORE ZONAL WITH A SOUTHWEST
ORIENTATION. THIS ZONAL UPPER FLOW WILL STEER A COLD FRONTAL BAND OF
SHOWERS EASTWARD THROUGH THE UPPER OHIO VALLEY SUNDAY NIGHT INTO
MONDAY.
FORECASTED TEMPERATURES, USING BLEND OF GFS AND NAEFS MODEL OUTPUT,
TO BE NEAR NORMAL FRIDAY, FOLLOWED BY A PREFRONTAL WARM UP SATURDAY
AND SUNDAY TO VALUES UP TO 10 DEGREES ABOVE NORMAL. TEMPERATURES
MONDAY SHOULD BE CLOSER TO NORMAL DUE TO CLOUDS AND SHOWERS AND
POTENTIAL POSTFRONTAL COOLING, ALTHOUGH THE LATTER WILL BE LIMITED
BY THE SOUTHWEST WINDS ALOFT.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT MAINLY CLEAR SKIES
TONIGHT.
SURFACE WINDS WILL BE FROM THE NORTH AND NORTHEAST AT NO MORE THAN 8
KTS THROUGH EARLY EVENING, THEN BECOME LIGHT TONIGHT.
OUTLOOK...TUESDAY THROUGH SATURDAY...
RESTRICTIONS POSSIBLE TUESDAY LATE AFTERNOON AND NIGHT WITH
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS. VFR WEDNESDAY THROUGH
SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 2 AM TO 8 AM EDT TUESDAY FOR MDZ001.
OH...NONE.
PA...FREEZE WARNING FROM 2 AM TO 8 AM EDT TUESDAY FOR PAZ007>009-
013>016-022-023-074-076.
WV...FREEZE WARNING FROM 2 AM TO 8 AM EDT TUESDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
158 PM EDT MON APR 2 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY AND DROP
TEMPERATURES NEAR FREEZING TONIGHT ACROSS PORTIONS OF THE AREA. A
FRONTAL BOUNDARY WILL APPROACH FROM THE SOUTHWEST TOMORROW, BRINGING
WARMER TEMPERATURES WITH THE CHANCE OF SHOWERS AND THUNDERSTORMS
TOMORROW NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO CLEAR
OUT THE SKY GRIDS THROUGH THE PRE-DAWN HOURS ON TUESDAY.
THE LATEST RUC 300MB ANALYSIS INDICATES RIDGING AND WEAK
WINDS ALOFT BEGINNING TO BUILD INTO THE OHIO VALLEY FROM THE WEST AS A
140KT JET SLIDES EAST OF THE AREA INTO THE NORTHEAST. A SWATH OF
DRY AIR IS EVIDENT SLIDING SOUTHEASTWARD ACROSS WESTERN PA. AT
THE SURFACE, A 1025MB HIGH IS CENTERED OVER THE HUDSON BAY WITH
HIGH PRESSURE EXTENDING SOUTHEASTWARD INTO THE GREAT LAKES.
TODAY AND TONIGHT...THERE IS OPERATIONAL MODEL AGREEMENT THAT THE
RIDGE WILL EDGE EASTWARD AND BECOME CENTERED OVER THE GREAT LAKES. A
NORTHWESTERLY FLOW ALOFT WILL ALLOW FOR HIGH PRESSURE TO SLIDE
FURTHER SOUTHWARD INTO THE UPPER OHIO VALLEY, BECOMING CENTERED
NORTHEAST OF PITTSBURGH BY 12Z TUESDAY. THUS, CLEAR SKIES CAN BE
EXPECTED THROUGH THIS PERIOD.
TEMPS ARE IN LINE WITH THE PREVIOUS FORECAST, SO FORECAST HIGHS
CONTINUE TO BE A FEW DEGREES WARMER THAN A MAV/MET BLEND AND
SEASONAL NORMS. THE BEST RADIATIONAL COOLING TONIGHT WILL OCCUR
CLOSEST TO THE SURFACE HIGH, WHICH WILL BE NORTHEAST OF PITTSBURGH.
CURRENTLY, THE MOST CONFIDENCE IN A FREEZE IS ALONG THE I-80 CORRIDOR.
PATCHY FROST IS FORECAST FOR AREAS NORTHEAST OF PITTSBURGH AND
ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
HAVE MAINTAINED A FORECAST OF CHANCE SHOWERS AND THUNDERSTORMS IN
THE WARM ADVECTION REGIME OF THE AFOREMENTIONED LOW PRESSURE SYSTEM
ON TUESDAY AFTERNOON AND WITH THE COLD FRONT ON TUESDAY NIGHT.
HIGH PRESSURE WILL FOLLOW WITH DRY AND COOLER CONDITIONS WEDNESDAY.
THE SHORT TERM TEMPERATURE FORECAST WAS COMPLETED USING A BLEND
OF GUIDANCE AND FEATURES READINGS FROM 5 TO 10 DEGREES ABOVE
NORMAL TUESDAY...AND NEAR NORMAL FOR WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
DRY WEATHER SHOULD PREVAIL ACROSS THE UPPER OHIO VALLEY REGION INTO
THE WEEKEND AS A LARGE AREA OF HIGH PRESSURE SLIDES SOUTHEAST ACROSS
THE GREAT LAKES.
A SLOW MOVING LOW PRESSURE SYSTEM WILL TRACK EASTWARD FROM THE LOWER
MS VALLEY TO OFF SOUTHEAST COAST LATE IN THE WEEK. THE BULK OF
ASSOCIATED MOISTURE IS PROGGED TO REMAIN SOUTH OF THE FORECAST AREA.
HPC GUIDANCE SHOWS THE NEXT COLD FRONT APPROACHING FROM THE WEST
WITH A CHANCE OF SHOWERS LATE SUNDAY.
TEMPERATURES ARE FORECAST TO BE NEAR NORMAL THROUGH FRIDAY...THEN
WARMING TO AROUND 10 DEGREES ABOVE NORMAL DURING THE WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT NO MORE THAN FEW VFR
CUMULUS THIS AFTERNOON, THEN NO MORE THAN FEW CIRRUS TONIGHT.
SURFACE WINDS WILL BE FROM THE NORTH AND NORTHEAST NO MORE THAN 10
KTS THIS AFTERNOON, GOING LIGHT TONIGHT.
OUTLOOK...TUESDAY THROUGH SATURDAY...
RESTRICTIONS POSSIBLE TUESDAY LATE AFTERNOON AND NIGHT WITH
SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS. OTHERWISE VFR.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
145 PM EDT MON APR 2 2012
.UPDATE...
ISSUED AT 1228 PM EDT MON APR 2 2012
BASED ON 12Z RAOB FROM KINL AND LOOKING AT NAM SNDG FOR KIWD FOR
THIS AFTERNOON...I AM SKEPTICAL ABOUT SHRA/TSRA CHCS THIS AFTERNOON.
DESPITE INCREASE IN WAA AT NOSE OF 30 KT 850 MB JET AND INCREASE IN
8H THETA-E VALUES BY LATE AFTERNOON...NAM MODEL SNDG FOR KIWD LIFTED
AT 800 MB STILL INDICATED A CAP AT AROUND 650 MB WITH OVER 25 J/KG
OF CIN AND LESS THAN 200 J/KG. THIS CAP IS ALSO REFLECTED IN 12Z
KINL SNDG. AS A RESULT OF INSTABILITY BEING MARGINAL AT BEST...HAVE
DECIDED TO TRIM BACK POPS TO SLIGHT CHC FOR GOGEBIC AND ONTONAGON
THIS AFTERNOON AND REMOVE POPS FARTHER TO THE EAST.
&&
.SYNOPSIS...
ISSUED AT 515 AM EDT MON APR 2 2012
UPPER RIDGE BUILDS INTO THE AREA TODAY BUT MOISTURE ADVECTION AT
H85/H7 IS ALREADY SPAWNING SHRA/TSRA FM NORTHERN MN INTO NW WI AND
TOWARD FAR WESTERN UPR MI. WILL HAVE TO CONTEND WITH AT LEAST ISOLD
SHRA/TSRA TODAY MAINLY OVR WEST THIRD OF CWA. BETTER CHANCE FOR RAIN
ARRIVES LATER TONIGHT AS SFC LOW AND INVERTED TROUGH SLIDE ACROSS
UPR MI. SOME RAIN LINGERS ON TUESDAY MORNING BUT AFTER THAT DRY
WEATHER DOMINATES THE REST OF THE WEEK AS HIGH PRESSURE EXPANDS FM
HUDSON BAY ACROSS THE GREAT LAKES REGION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
TODAY...UPPER RIDGE CONTINUES TO BUILD FM THE PLAINS INTO THE
WESTERN GREAT LAKES THROUGH THE DAY WHILE AT THE SFC...HIGH OVR
HUDSON BAY WILL EXPAND A RIDGE AXIS ACROSS MUCH OF MICHIGAN. AT
FIRST GLANCE...DOES NOT APPEAR TO BE A FAVORABLE SETUP FOR MUCH
PRECIPITATION TODAY OVR UPR MI...BUT CERTAINLY CANNOT IGNORE
CLUSTER OF SHRA/TSRA THAT HAVE FORMED OVR NORTHERN MN INTO
NORTHWEST WI THE LAST FEW HOURS. SHRA/TSRA SEEM TO BE RUNNING ALONG
AND NORTH OF RIBBON OF HIGHER H7 DWPNTS AND ON NORTHERN EDGE OF
STEEPER H7-H5 LAPSE RATES FM MN INTO WI. ONLY 00Z GUIDANCE THAT
SHOWED TSRA AS FAR EAST AS IS CURRENTLY OCCURRING WAS HRRR. ALL
OTHER GUIDANCE KEPT GENESIS REGION FOR SHRA/TSRA OVR WESTERN MN
WHERE BETTER H85 THETA-E ADVECTION IS TAKING PLACE.
FOLLOWING RUC13/NAM H7 DWPNTS/WINDS SUGGESTS THAT AT LEAST ISOLD
TSRA WILL EASE INTO WESTERN THIRD OF CWA THIS MORNING BEFORE FADING
AWAY AS RIBBON OF HIGHER H7 DWPNT WEAKENS. WILL KEEP POPS IN OVR
WEST ALL DAY THOUGH AS RUC INDICATES HINT OF H7 MOISTURE AXIS COULD
PERSIST INTO EARLY AFTN. DESPITE RESERVOIR OF H7-H5 LAPSE RATES AOA
8C/KM UPSTREAM...MINIMAL LARGE SCALE FORCING AND MARGINAL 3-6KM
SHEAR /20KT OR SO/ SHOULD LEAD TO ONLY SLIM CHANCES OF SEEING
HAIL WITH THESE STORMS. WILL NEED TO MONITOR TRENDS THIS MORNING
THOUGH. BY LATE AFTN...EXPECT MAIN AREA OF SHRA/TSRA WEST OF UPR
MI IN AREA OF GREATEST H85 TEMP/MOISTURE ADVECTION.
OTHER ISSUE TODAY ESPECIALLY THIS MORNING IS FOG. FOR THE MOST PART
THE FOG IS OVR HIGHER TERRAIN OF NCNTRL CWA AND HIGHER TERRAIN OF
KEWEENAW. EVEN IN THESE AREAS MAIN IMPACT IS MORE OF STRATUS DECK
WITH VARIABLE VSBY. EXPECT DRY ADVECTION OVR EASTERN UPR MI TO
SPREAD EAST AND DIMINISH THE FOG BY MID MORNING /AS ALREADY HAS
OCCURRED AT ERY EARLY THIS MORNING/. COVERAGE OF CLOUDS /LOWER AND
MID/ BY MID AFTN COULD BE CHAOTIC WHICH WILL NO-DOUBT IMPACT HIGH
TEMPS. SE GRADIENT WIND OFF THE LAKES SHOULD KEEP TEMPS IN CHECK
EVEN IF DECENT AMOUNT OF SUNSHINE ENDS UP OCCURRING. EXPECT HIGHS TO
MAINLY TOP OUT IN THE 50S...COOLER NCNTRL WITH UPSLOPE FLOW. GIVEN
ENOUGH SUNSHINE SOME SPOTS MAY PUSH PAST 60 DEGREES...BUT NOT TOO
MUCH HIGHER.
TONIGHT...UPR RIDGE REMAINS IN TACT TO START THE EVENING THEN
OVERNIGHT NORTHERN STREAM SHORTWAVE MOVES FM MANITOBA INTO
NORTHWEST ONTARIO. AS THIS TROUGH APPROACHES...SFC LOW OVR THE
PLAINS WILL LIFT INTO WESTERN GREAT LAKES WITH INVERTED SFC TROUGH
AND H85 TROUGH SLIDING WEST TO EAST ACROSS UPR MI. MODELS HAVE
TRENDED A BIT SLOWER WITH ARRIVAL OF UPR AND SFC TROUGH. PREVIOUS
FCST HAD GOOD HANDLE ON TREND WITH HIGHER POPS OVERNIGHT. WHAT TO DO
WITH POP COVERAGE IS MAIN ISSUE. BASED ON EXPECTED LARGE SCALE
PATTERN AND FCST LOCATION OF HIGHER MUCAPE...WOULD FIGURE THAT
HIGHEST POPS WOULD BE OVER LK SUPERIOR AND MAINLY TO SOUTH OF CWA.
THOUGH CONVERGENCE FM INVERTED SFC TROUGH INTERSECTING S/SW FLOW AT
H85 /DPWNTS AOA +10C/ SUPPORTS HIGHER POPS OVR CWA AS WELL. KEPT
POPS HIGH CHANCE TO LIKELY AS THE INVERTED TROUGH SLIDES THROUGH CWA.
TSRA CHANCES SEEM MINIMAL BASED ON MAIN MUCAPE STAYING OVR WI AND
850-300MB THICKNESSES ORIENTED WNW TO ESE. HOWEVER...IF CONVECTION
MAINLY FIRES ON FAR NORTH EDGE OF HIGHER INSTABILITY /AS OCCURRED
THIS MORNING/ THEN IT IS FEASIBLE THERE COULD BE COMPLEX OF TSRA
AFFECTING PORTIONS OF CWA OVERNIGHT TONGIHT INTO EARLY TUESDAY
MORNING. LIKELY WILL NOT KNOW IF THIS IS THE CASE UNTIL MAYBE LATE
THIS EVENING OR OVERNIGHT TONIGHT.
TUESDAY...SLOWER TREND OF TROUGH PASSAGE CONTINUES TO SHOW UP INTO
TUESDAY AND HAVE DELAYED DIMINISHING POPS UNTIL EARLY TUESDAY AFTN.
AT THIS POINT /COULD BE FURTHER SLOWER TREND/ HIGHEST POPS ON
TUESDAY WILL BE THROUGH ROUGHLY 16Z /NOON EDT/ OVR EASTERN HALF OF
CWA MAINLY TO EAST OF MARQUETTE AND IRON MOUNTAIN. KEPT SMALL
CHANCES FOR TSRA IN PICTURE ALONG LK MICHIGAN IN THE MORNING UNTIL
H85 WINDS VEER WEST PUSHING THE HIGHER H85 DWPNTS/INSTABILITY TO
SOUTHEAST OF CWA. WINDS TURNING NORTH BEHIND THE TROUGH SHOULD KEEP
CLOUDS IN OVR MUCH CWA THROUGH MUCH OF AFTN. DECREASING CLOUDS
EXPECTED LATE AFTN THOUGH PER MODEL CONSENSUS OF RAPIDLY LOWERING
DWPNTS AT H85 AND PER FCST SOUNDINGS. POSSIBLE THAT SOME LOW CLOUDS
AND/OR FOG MAY TRY TO ADVECT ONSHORE SIMILAR TO WHAT OCCURRED SUNDAY
AFTN. LATER SHIFTS CAN ADDRESS THIS IN MORE DETAIL AND ADD IF IT
SEEMS REASONABLE. LOWERED TEMPS ESPECIALLY IN THE NORTH CWA DUE TO
LATER DEPARTURE OF PCPN AND CLOUDS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
HIGH PRESSURE SLIDING IN TUESDAY EVENING FROM MANITOBA AND EASTERN
ND/WESTERN MN WILL BRING ABOUT A PROLONGED PERIOD OF DRY WEATHER.
EXPECT THE HIGH TO PUSH OVER THE UPPER GREAT LAKES WEDNESDAY
AFTERNOON...BEFORE STRENGTHENING ACROSS THE AREA THROUGH FRIDAY.
GIVEN A SLIGHTLY SLOWER SOLUTION AND A LINGERING 500MB TROUGH
OVERHEAD THROUGH WEDNESDAY EVENING...WILL KEEP WITH LINGERING CLOUDS
EAST INITIALLY TUESDAY NIGHT...AND AFTERNOON CLOUDS DEVELOPING NEAR
900MB POSSIBLE CENTRAL AND EAST. EXPECT ONLY LIMITED CLOUDS AT THIS
TIME GIVEN OUR DRY ATMOSPHERE WITH PW VALUES ABOUT 60 PERCENT OF
NORMAL AROUND 0.26IN.
LOWERED DEW POINTS A COUPLE OF DEGREES FOR WEDNESDAY
AFTERNOON...MAINLY INTERIOR WEST...WITH RH VALUES ACROSS THIS AREA
BOTTOMING OUT AROUND 25 TO 30 PERCENT. WITH NO SIGNIFICANT INFLUX OF
MOISTURE...RH VALUES SHOULD FALL BETWEEN 25 AND 35 PERCENT THROUGH
FRIDAY /ONCE AGAIN MAINLY ACROSS THE INTERIOR WEST HALF/.
LOW PRESSURE DEVELOPING OFF THE NORTHERN ROCKIES MID WEEK SHOULD
PUSH ACROSS THE PLAINS STATES FRIDAY NIGHT...BEFORE SLIDING
DEEPENING TO OUR WEST SATURDAY...AND PUSHING UP AND ACROSS ONTARIO
SATURDAY NIGHT INTO SUNDAY. THE FORECAST MODELS LOOK TO BE IN FAIRLY
GOOD AGREEMENT UNTIL THE FOCUS SHIFTS TO THE NEARING LOW SATURDAY
AFTERNOON. AFTER SATURDAY...I HAVE ONLY MODERATE CONFIDENCE IN THE
ONGOING FORECAST /MAINLY WITH RESPECT TO TIMING AND PRECIPITATION
TYPE AS THE LOW EXITS/.
AFTERNOON TS SATURDAY MAY LINGER INTO SATURDAY NIGHT EAST. WHILE THE
QUICKER 01/12Z RUN OF THE ECMWF WOULD HAVE THEM OUT OF ERY BY 06Z
SUNDAY. WILL TAKE OUT ANY MENTION OF WRAP AROUND SHSN SUNDAY...BUT
IT MAY NEED TO BE ADDED BACK IN IF THE ECMWF VERIFIES WITH 850MB
TEMPS FALLING TO AROUND -3 OR -4C BY EARLY AFTERNOON WEST AND
CENTRAL. INSTEAD OF RUNNING A NON-DIURNAL TEMP TRACE FOR
SUNDAY...KEPT WITH TRADITIONAL RISING TEMPS DURING THE DAY /SIMILAR
TO THE GFS/. AS NOTED...THIS WILL LIKELY BE REVISED MORE THAN A FEW
TIMES BEFORE OVER THE NEXT FEW DAYS AS FCST MODELS MERGE ON A
SOLUTION...SO WILL NOT GET TOO SPECIFIC AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 143 PM EDT MON APR 2 2012
SUNSHINE AND ASSOC MIXING OVER THE TAF SITES TODAY ALONG WITH AN
INCREASE IN MID CLOUD COVER FROM THE WEST THIS EVENING SHOULD
PREVENT THE DEVELOPMENT OF LOW CLOUDS AND FOG TONIGHT. EXPECT VFR
CONDITIONS TO CONTINUE AT ALL THE TAF SITES UNTIL LATE TONIGHT INTO
WEDNESDAY WHEN WINDS COME AROUND TO THE NNW BEHIND FRONTAL BOUNDARY
MOVING THROUGH THE AREA. DUE TO WEAK FORCING ALONG THE FRONTAL
BOUNDARY...SHOWER COVERAGE WILL LIKELY BE SCATTERED AND FAIRLY
LIGHT. ALSO THERE IS LESS CERTAINTY THAT SHOWERS WILL BE THE
PREVAILING CONDITION AT THE TAF SITES TONIGHT INTO WEDNESDAY EXCEPT
FOR MAYBE KIWD WHICH COULD SEE SOME AFTERNOON CONVECTION MOVE IN
THERE THIS EVENING. AT KCMX AND KSAW WILL CONTINUE MENTION OF JUST
VICINITY SHRA IN TAF. NOT EXPECTING MUCH REDUCTION IN VSBY FROM ANY
OF THE SHOWERS...BUT COULD SEE AN MVFR CLOUD DECK DEVELOP IN THE
WAKE OF THE FRONTAL BOUNDARY LATE TONIGHT AND WED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON APR 2 2012
WINDS SHOULD REMAIN BELOW 30KTS THROUGH AT LEAST FRIDAY. AN EXITING
RIDGE OVER LAKE HURON WILL DRIFT ACROSS THE LOWER GREAT LAKES TODAY.
IN ITS PLACE...A TROUGH WILL SLIDE IN FOR LATE TONIGHT INTO TUESDAY
MORNING. EXPECT A HIGH OVER THE NORTHERN PLAINS AND CENTRAL CANADA
TUESDAY TO SLOWLY SLIDE OVER LS WEDNESDAY...WHERE IT SHOULD REMAIN
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...VOSS
SYNOPSIS...JLA
SHORT TERM...JLA
LONG TERM...KF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1230 PM EDT MON APR 2 2012
.UPDATE...
ISSUED AT 1228 PM EDT MON APR 2 2012
BASED ON 12Z RAOB FROM KINL AND LOOKING AT NAM SNDG FOR KIWD FOR
THIS AFTERNOON...I AM SKEPTICAL ABOUT SHRA/TSRA CHCS THIS AFTERNOON.
DESPITE INCREASE IN WAA AT NOSE OF 30 KT 850 MB JET AND INCREASE IN
8H THETA-E VALUES BY LATE AFTERNOON...NAM MODEL SNDG FOR KIWD LIFTED
AT 800 MB STILL INDICATED A CAP AT AROUND 650 MB WITH OVER 25 J/KG
OF CIN AND LESS THAN 200 J/KG. THIS CAP IS ALSO REFLECTED IN 12Z
KINL SNDG. AS A RESULT OF INSTABILITY BEING MARGINAL AT BEST...HAVE
DECIDED TO TRIM BACK POPS TO SLIGHT CHC FOR GOGEBIC AND ONTONAGON
THIS AFTERNOON AND REMOVE POPS FARTHER TO THE EAST.
&&
.SYNOPSIS...
ISSUED AT 515 AM EDT MON APR 2 2012
UPPER RIDGE BUILDS INTO THE AREA TODAY BUT MOISTURE ADVECTION AT
H85/H7 IS ALREADY SPAWNING SHRA/TSRA FM NORTHERN MN INTO NW WI AND
TOWARD FAR WESTERN UPR MI. WILL HAVE TO CONTEND WITH AT LEAST ISOLD
SHRA/TSRA TODAY MAINLY OVR WEST THIRD OF CWA. BETTER CHANCE FOR RAIN
ARRIVES LATER TONIGHT AS SFC LOW AND INVERTED TROUGH SLIDE ACROSS
UPR MI. SOME RAIN LINGERS ON TUESDAY MORNING BUT AFTER THAT DRY
WEATHER DOMINATES THE REST OF THE WEEK AS HIGH PRESSURE EXPANDS FM
HUDSON BAY ACROSS THE GREAT LAKES REGION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
TODAY...UPPER RIDGE CONTINUES TO BUILD FM THE PLAINS INTO THE
WESTERN GREAT LAKES THROUGH THE DAY WHILE AT THE SFC...HIGH OVR
HUDSON BAY WILL EXPAND A RIDGE AXIS ACROSS MUCH OF MICHIGAN. AT
FIRST GLANCE...DOES NOT APPEAR TO BE A FAVORABLE SETUP FOR MUCH
PRECIPITATION TODAY OVR UPR MI...BUT CERTAINLY CANNOT IGNORE
CLUSTER OF SHRA/TSRA THAT HAVE FORMED OVR NORTHERN MN INTO
NORTHWEST WI THE LAST FEW HOURS. SHRA/TSRA SEEM TO BE RUNNING ALONG
AND NORTH OF RIBBON OF HIGHER H7 DWPNTS AND ON NORTHERN EDGE OF
STEEPER H7-H5 LAPSE RATES FM MN INTO WI. ONLY 00Z GUIDANCE THAT
SHOWED TSRA AS FAR EAST AS IS CURRENTLY OCCURRING WAS HRRR. ALL
OTHER GUIDANCE KEPT GENESIS REGION FOR SHRA/TSRA OVR WESTERN MN
WHERE BETTER H85 THETA-E ADVECTION IS TAKING PLACE.
FOLLOWING RUC13/NAM H7 DWPNTS/WINDS SUGGESTS THAT AT LEAST ISOLD
TSRA WILL EASE INTO WESTERN THIRD OF CWA THIS MORNING BEFORE FADING
AWAY AS RIBBON OF HIGHER H7 DWPNT WEAKENS. WILL KEEP POPS IN OVR
WEST ALL DAY THOUGH AS RUC INDICATES HINT OF H7 MOISTURE AXIS COULD
PERSIST INTO EARLY AFTN. DESPITE RESERVOIR OF H7-H5 LAPSE RATES AOA
8C/KM UPSTREAM...MINIMAL LARGE SCALE FORCING AND MARGINAL 3-6KM
SHEAR /20KT OR SO/ SHOULD LEAD TO ONLY SLIM CHANCES OF SEEING
HAIL WITH THESE STORMS. WILL NEED TO MONITOR TRENDS THIS MORNING
THOUGH. BY LATE AFTN...EXPECT MAIN AREA OF SHRA/TSRA WEST OF UPR
MI IN AREA OF GREATEST H85 TEMP/MOISTURE ADVECTION.
OTHER ISSUE TODAY ESPECIALLY THIS MORNING IS FOG. FOR THE MOST PART
THE FOG IS OVR HIGHER TERRAIN OF NCNTRL CWA AND HIGHER TERRAIN OF
KEWEENAW. EVEN IN THESE AREAS MAIN IMPACT IS MORE OF STRATUS DECK
WITH VARIABLE VSBY. EXPECT DRY ADVECTION OVR EASTERN UPR MI TO
SPREAD EAST AND DIMINISH THE FOG BY MID MORNING /AS ALREADY HAS
OCCURRED AT ERY EARLY THIS MORNING/. COVERAGE OF CLOUDS /LOWER AND
MID/ BY MID AFTN COULD BE CHAOTIC WHICH WILL NO-DOUBT IMPACT HIGH
TEMPS. SE GRADIENT WIND OFF THE LAKES SHOULD KEEP TEMPS IN CHECK
EVEN IF DECENT AMOUNT OF SUNSHINE ENDS UP OCCURRING. EXPECT HIGHS TO
MAINLY TOP OUT IN THE 50S...COOLER NCNTRL WITH UPSLOPE FLOW. GIVEN
ENOUGH SUNSHINE SOME SPOTS MAY PUSH PAST 60 DEGREES...BUT NOT TOO
MUCH HIGHER.
TONIGHT...UPR RIDGE REMAINS IN TACT TO START THE EVENING THEN
OVERNIGHT NORTHERN STREAM SHORTWAVE MOVES FM MANITOBA INTO
NORTHWEST ONTARIO. AS THIS TROUGH APPROACHES...SFC LOW OVR THE
PLAINS WILL LIFT INTO WESTERN GREAT LAKES WITH INVERTED SFC TROUGH
AND H85 TROUGH SLIDING WEST TO EAST ACROSS UPR MI. MODELS HAVE
TRENDED A BIT SLOWER WITH ARRIVAL OF UPR AND SFC TROUGH. PREVIOUS
FCST HAD GOOD HANDLE ON TREND WITH HIGHER POPS OVERNIGHT. WHAT TO DO
WITH POP COVERAGE IS MAIN ISSUE. BASED ON EXPECTED LARGE SCALE
PATTERN AND FCST LOCATION OF HIGHER MUCAPE...WOULD FIGURE THAT
HIGHEST POPS WOULD BE OVER LK SUPERIOR AND MAINLY TO SOUTH OF CWA.
THOUGH CONVERGENCE FM INVERTED SFC TROUGH INTERSECTING S/SW FLOW AT
H85 /DPWNTS AOA +10C/ SUPPORTS HIGHER POPS OVR CWA AS WELL. KEPT
POPS HIGH CHANCE TO LIKELY AS THE INVERTED TROUGH SLIDES THROUGH CWA.
TSRA CHANCES SEEM MINIMAL BASED ON MAIN MUCAPE STAYING OVR WI AND
850-300MB THICKNESSES ORIENTED WNW TO ESE. HOWEVER...IF CONVECTION
MAINLY FIRES ON FAR NORTH EDGE OF HIGHER INSTABILITY /AS OCCURRED
THIS MORNING/ THEN IT IS FEASIBLE THERE COULD BE COMPLEX OF TSRA
AFFECTING PORTIONS OF CWA OVERNIGHT TONGIHT INTO EARLY TUESDAY
MORNING. LIKELY WILL NOT KNOW IF THIS IS THE CASE UNTIL MAYBE LATE
THIS EVENING OR OVERNIGHT TONIGHT.
TUESDAY...SLOWER TREND OF TROUGH PASSAGE CONTINUES TO SHOW UP INTO
TUESDAY AND HAVE DELAYED DIMINISHING POPS UNTIL EARLY TUESDAY AFTN.
AT THIS POINT /COULD BE FURTHER SLOWER TREND/ HIGHEST POPS ON
TUESDAY WILL BE THROUGH ROUGHLY 16Z /NOON EDT/ OVR EASTERN HALF OF
CWA MAINLY TO EAST OF MARQUETTE AND IRON MOUNTAIN. KEPT SMALL
CHANCES FOR TSRA IN PICTURE ALONG LK MICHIGAN IN THE MORNING UNTIL
H85 WINDS VEER WEST PUSHING THE HIGHER H85 DWPNTS/INSTABILITY TO
SOUTHEAST OF CWA. WINDS TURNING NORTH BEHIND THE TROUGH SHOULD KEEP
CLOUDS IN OVR MUCH CWA THROUGH MUCH OF AFTN. DECREASING CLOUDS
EXPECTED LATE AFTN THOUGH PER MODEL CONSENSUS OF RAPIDLY LOWERING
DWPNTS AT H85 AND PER FCST SOUNDINGS. POSSIBLE THAT SOME LOW CLOUDS
AND/OR FOG MAY TRY TO ADVECT ONSHORE SIMILAR TO WHAT OCCURRED SUNDAY
AFTN. LATER SHIFTS CAN ADDRESS THIS IN MORE DETAIL AND ADD IF IT
SEEMS REASONABLE. LOWERED TEMPS ESPECIALLY IN THE NORTH CWA DUE TO
LATER DEPARTURE OF PCPN AND CLOUDS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 515 AM EDT MON APR 2 2012
HIGH PRESSURE SLIDING IN TUESDAY EVENING FROM MANITOBA AND EASTERN
ND/WESTERN MN WILL BRING ABOUT A PROLONGED PERIOD OF DRY WEATHER.
EXPECT THE HIGH TO PUSH OVER THE UPPER GREAT LAKES WEDNESDAY
AFTERNOON...BEFORE STRENGTHENING ACROSS THE AREA THROUGH FRIDAY.
GIVEN A SLIGHTLY SLOWER SOLUTION AND A LINGERING 500MB TROUGH
OVERHEAD THROUGH WEDNESDAY EVENING...WILL KEEP WITH LINGERING CLOUDS
EAST INITIALLY TUESDAY NIGHT...AND AFTERNOON CLOUDS DEVELOPING NEAR
900MB POSSIBLE CENTRAL AND EAST. EXPECT ONLY LIMITED CLOUDS AT THIS
TIME GIVEN OUR DRY ATMOSPHERE WITH PW VALUES ABOUT 60 PERCENT OF
NORMAL AROUND 0.26IN.
LOWERED DEW POINTS A COUPLE OF DEGREES FOR WEDNESDAY
AFTERNOON...MAINLY INTERIOR WEST...WITH RH VALUES ACROSS THIS AREA
BOTTOMING OUT AROUND 25 TO 30 PERCENT. WITH NO SIGNIFICANT INFLUX OF
MOISTURE...RH VALUES SHOULD FALL BETWEEN 25 AND 35 PERCENT THROUGH
FRIDAY /ONCE AGAIN MAINLY ACROSS THE INTERIOR WEST HALF/.
LOW PRESSURE DEVELOPING OFF THE NORTHERN ROCKIES MID WEEK SHOULD
PUSH ACROSS THE PLAINS STATES FRIDAY NIGHT...BEFORE SLIDING
DEEPENING TO OUR WEST SATURDAY...AND PUSHING UP AND ACROSS ONTARIO
SATURDAY NIGHT INTO SUNDAY. THE FORECAST MODELS LOOK TO BE IN FAIRLY
GOOD AGREEMENT UNTIL THE FOCUS SHIFTS TO THE NEARING LOW SATURDAY
AFTERNOON. AFTER SATURDAY...I HAVE ONLY MODERATE CONFIDENCE IN THE
ONGOING FORECAST /MAINLY WITH RESPECT TO TIMING AND PRECIPITATION
TYPE AS THE LOW EXITS/.
AFTERNOON TS SATURDAY MAY LINGER INTO SATURDAY NIGHT EAST. WHILE THE
QUICKER 01/12Z RUN OF THE ECMWF WOULD HAVE THEM OUT OF ERY BY 06Z
SUNDAY. WILL TAKE OUT ANY MENTION OF WRAP AROUND SHSN SUNDAY...BUT
IT MAY NEED TO BE ADDED BACK IN IF THE ECMWF VERIFIES WITH 850MB
TEMPS FALLING TO AROUND -3 OR -4C BY EARLY AFTERNOON WEST AND
CENTRAL. INSTEAD OF RUNNING A NON-DIURNAL TEMP TRACE FOR
SUNDAY...KEPT WITH TRADITIONAL RISING TEMPS DURING THE DAY /SIMILAR
TO THE GFS/. AS NOTED...THIS WILL LIKELY BE REVISED MORE THAN A FEW
TIMES BEFORE OVER THE NEXT FEW DAYS AS FCST MODELS MERGE ON A
SOLUTION...SO WILL NOT GET TOO SPECIFIC AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM EDT MON APR 2 2012
LOW CLOUDS AND SOME FOG WILL AFFECT CMX AND SAW THROUGH MID MORNING.
MAIN IMPACT WILL BE CIGS BLO ALTERNATE AIRPORT MINS BUT BRIEF VSBY
OF LIFR/IFR POSSIBLE AS WELL. PROBLEM AT IWD WILL BE SHRA/ISOLD TSRA
THROUGH MID MORNING. COULD SEE BRIEF VSBY REDUCTIONS BUT SHOULD ONLY
BE MVFR BASED ON UPSTREAM OBSERVATIONS AND SINCE SE WIND DIRECTION
IS NOT FAVORABLE FOR ANY ADDITIONAL LIFTING VIA UPSLOPE. EXPECT ALL
TAF SITES TO BE VFR BY EARLY AFTN WITH SCT-BKN MID CLOUDS. MAIN
FRONT AND SFC LOW COME ACROSS UPR MICHIGAN TONIGHT. SCT LINE OF SHRA
AND PERHAPS A TSRA AS WELL WILL SLIDE WEST-TO-EAST LATER IN THE
EVENING THROUGH THE OVERNIGHT HOURS. MODELS VARY ON EXACT DEPICTION
OF RAIN WITH FROPA SO KEPT WITH BROADBRUSHED DEPICTION FOR THE
TIMING OF THE RAIN. POTENTIAL FOR SIGNIFICANT REDUCTION TO CIGS/VSBY
WITH ANY SHOWERS DOES APPEAR REMOTE RIGHT NOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 AM EDT MON APR 2 2012
WINDS SHOULD REMAIN BELOW 30KTS THROUGH AT LEAST FRIDAY. AN EXITING
RIDGE OVER LAKE HURON WILL DRIFT ACROSS THE LOWER GREAT LAKES TODAY.
IN ITS PLACE...A TROUGH WILL SLIDE IN FOR LATE TONIGHT INTO TUESDAY
MORNING. EXPECT A HIGH OVER THE NORTHERN PLAINS AND CENTRAL CANADA
TUESDAY TO SLOWLY SLIDE OVER LS WEDNESDAY...WHERE IT SHOULD REMAIN
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...VOSS
SYNOPSIS...JLA
SHORT TERM...JLA
LONG TERM...KF
AVIATION...JLA
MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
330 PM CDT MON APR 2 2012
.DISCUSSION...
SEVERE WEATHER THREAT REMAINS MAIN FOCUS FOR THE EVENING. LATEST
AVAILABLE RUC INDICATING WARM SECTOR TO WORK INTO SOUTH CENTRAL
MINNESOTA THIS EVENING. MLCIN DROP OFF MARKEDLY AS WELL...BUT
BELIEVE CAP WILL HOLD FOR ANY REAL SURFACE BASED CONVECTION.
SHOULD SEE ELEVATED ACTIVITY INITIATE OVER SOUTHWEST MINNESOTA NEAR
REDWOOD FALLS...AND THEN MOVE EAST DURING THE EVENING...AFFECTING
SOUTH CENTRAL MINNESOTA. MOST ALL DETERMINISTIC RUNS INDICATE THIS
AS WELL. VERY STEEP/UNSTABLE MID LEVEL LAPSE RATES IN EXCESS OF
8C/KM WITH ELEVATED CAPE AROUND 1200 J/KG MOVING...SHOULD BE
ENOUGH TO GENERATE THE CONVECTION. HAIL WILL BE THE MAIN THREAT
WITH SOME WIND POSSIBLE AS WELL.
UPPER TROUGH MOVES ACROSS THE CWA OVERNIGHT...AND IS SLOWER THAN
WHAT MODELS WERE SHOWING YESTERDAY. WILL HAVE TO LINGER SOME
SLIGHT CHANCE POPS OVER THE SOUTHERN CWA INTO TUESDAY MORNING...
WITH CLEARING EXPECTED THEREAFTER. COOLER TEMPERATURES EXPECTED
THEN FOR THE NEXT SEVERAL DAYS...BUT STILL RANGING ABOVE NORMAL.
NORTHERLY WINDS WILL INCREASE TONIGHT BEHIND DEPARTING SYSTEM AND
WILL REMAIN BREEZY INTO TUESDAY AS THE COLDER AIR MOVES IN.
WINDS WILL DIMINISH TUESDAY EVENING AND WITH LARGE HIGH PRESSURE DROPPING
SOUTH OVER THE AREA...WILL LIKELY SEE SOME FROST DEVELOP INTO WEDNESDAY
MORNING. PREVIOUS FORECAST HAD THIS MENTIONED AND STILL LOOKS GOOD.
THERE WILL BE ANOTHER OPPORTUNITY FOR FROST...MAINLY OVER WEST
CENTRAL WISCONSIN WEDNESDAY NIGHT/THURSDAY MORNING AS THE HIGH
RETREATS TO THE EAST.
LONG RANGE MODELS CONTINUE TO TREND ANOTHER WAVE ACROSS THE AREA
LATER FRIDAY NIGHT INTO SATURDAY SATURDAY NIGHT TIME FRAME. EVEN
COLDER AIR TO FOLLOW THIS FRONT...POSSIBLE MAKING TEMPERATURES
CLOSER TO NORMAL FOR THIS TIME OF THE YEAR.
&&
.AVIATION.../18Z TAF ISSUANCE/
SFC LOW PRESSURE OVER SE SD WILL SHIFT ENE OVER SRN MN INTO WRN WI
THROUGH TONIGHT...DRAGGING A CDFNT WITH IT. LOW CLOUDS ARE
CONTINUING TO ERODE OVER SW AND W MN WHILE CENTRAL AND ERN MN INTO
WRN WI ARE DEALING WITH SCT COVERAGE OF HIGHER CLOUDS. GUSTY SE
WINDS WILL PERSIST THROUGH THIS EVENING THEN SETTLE DOWN A BIT
OVERNIGHT...BUT NOT EXPECTING MUCH BELOW 10 KT. AS THE SFC LOW
SHIFTS E...CHCS INCREASE FOR SHWRS WITH A FEW ISOLD TSTMS. BETTER
PROSPECTS FOR THUNDER OVER NRN MN AND IA...BUT ISOLD TS CANNOT BE
RULED OUT FOR ANY OF THE TAF SITES. THAT SAID...EVEN THE SHORT-
TERM MODELS ARE SHOWING DIFFERING SCENARIOS AS TO THE
LOCATION/TIMING OF THUNDER. HAVE TWEAKED THE TIMING OF THE TEMPO
GROUPS AT EACH SITE TO REFLECT BEST TIMING OF PRECIP BUT HAVE ONLY
USED MENTION OF CB TO INDICATE CONVECTION. FELT THIS WAS THE
BETTER WAY TO GO RATHER THAN TRYING TO PIN DOWN TS WITH LOW
CONFIDENCE. ONCE THE PRECIP CEASES DURING THE EARLY MRNG HOURS...
MVFR CIGS WILL LINGER THROUGH DAYBREAK. INCREASED LOW LEVEL
JETTING WILL PREVENT CIGS FROM GETTING DOWN TO IFR LEVELS OR
HAVING ANY SIGNIFICANT FOG DEVELOPING...BUT THERE SHOULD BE SOME
PERIODS OF MVFR VSBYS AFTER THE RAIN ENDS. AS THE LOW SHIFTS E AND
HIGH PRESSURE SLOWLY ENTERS FROM THE NW TMRW...CLOUDS WILL LIFT
AND SCATTER OUT...LEADING TO VFR CONDS BY MIDDAY TMRW. WINDS WILL
ALSO INCREASE AND BECOME GUSTY AGAIN AS THE PRESSURE GRADIENT
TIGHTENS WITH THE INCOMING HIGH PRESSURE.
MSP...VFR CONDS EXPECTED TO PREVAIL THROUGH THIS EVENING THOUGH
THERE MAY BE SOME BOUNCING BETWEEN SCT AND BKN COVERAGE WITH BASES
ARND 4000 FT. COVERAGE BECOMES DECIDEDLY BKN LATE THIS EVE AS THE
FRONTAL SYSTEM APPROACHES. BEST TIMING FOR PRECIP ONSET LOOKS TO
BE AROUND 06Z THEN CONTINUING TO SHORTLY BEFORE DAYBREAK. AM NOT
LOOKING FOR A PROLONGED DURATION OF PRECIP SINCE THIS IS MORE OF A
CONVECTIVELY-BASED EVENT RATHER THAN STRATIFORM...BUT ALTHOUGH MSP
TAF ADVERTISES NO PRECIP AFTER 10Z...SOME SHOWERS GOING INTO
SUNRISE CANNOT BE RULED OUT. THUNDER CHCS ARE RATHER LOW BUT WITH
ISOLD TSTMS POSSIBLE...CB MENTION LOOKS TO COVER THINGS.
CONDITIONS IMPROVE LATE MRNG INTO THE EARLY AFTN HOURS...BECOMING
VFR BY EARLY AFTN. GUSTY CONDITIONS THIS AFTN SETTLE DOWN A BIT
OVERNIGHT THEN RETURN TMRW WITH THE INCOMING HIGH PRESSURE.
OUTLOOK...
/TUE NIGHT-FRI/...VFR AS HIGH PRESSURE MOVES ACROSS.
/SAT-SUN/...POSSIBLE FRONTAL SYSTEM MOVES OVER THE NORTHERN PLAINS
INTO THE UPPER MISSISSIPPI RIVER VALLEY. MVFR CONDS POSSIBLE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
DWE/JPC
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1244 PM CDT MON APR 2 2012
.AVIATION...04/02/18Z ISSUANCE...
VFR IN BROKEN CLOUDS...WITH AREAS OF SCATTERED CLOUDS ACROSS
NORTHWEST WISCONSIN. ISOLATED INTENSE THUNDERSTORMS WITH HAIL...
JUST SOUTH OF INL...SHOULD SLOWLY WEAKEN AND PASS NORTHEAST INTO
CANADA NEAR RAINY LAKE LATE THIS AFTERNOON. SCATTERED MVFR IN
SHOWERS AND A FEW THUNDERSTORMS WILL DEVELOP OVER OUR AREA...WEST
OF A CENTRAL LAKE SUPERIOR TROUGH...THIS EVENING. VFR AND CLEARING
WILL SPREAD TOWARD THE SOUTHEAST BEGINNING IN NORTHEAST MINNESOTA
EARLY TUESDAY AND CONTINUING THROUGH NORTHWEST WISCONSIN AROUND
MIDDAY TUESDAY.
&&
.PREV DISCUSSION... /ISSUED 1027 AM CDT MON APR 2 2012/
UPDATE...
THE 12Z NAM AND 09Z SREF ARE REASONABLE IN THE PLACEMENT OF THE
CURRENT BAND OF ELEVATED THUNDERSTORMS STRETCHING FROM NEAR BIG
FORK TO CRANE LAKE IN THE NORTHWESTERN FA. THEREFORE...MADE
UPDATES TO POPS/WEATHER THROUGH THIS AFTERNOON THAT LEANED ON THE
NAM/SREF WHICH FOCUSES PCPN ACROSS THE NORTHERN AND WESTERN FA.
DOWNPLAYED THE EMPHASIS ON THE CHANCES OF THUNDER TO GIVE GREATER
EMPHASIS ON RAIN SHOWERS SINCE MODEL INDICES AND INSTABILITY DO
NOT APPEAR FAVORABLE FOR CONVECTION. AT THIS TIME...THE SPC
MESOANALYSIS PAGE INDICATES UP TO 5OO J/KG OF ELEVATED CAPE BY
THAT BAND OF THUNDERSTORMS...AND MOST UNSTABLE LIFTED INDICES
AROUND -2 TO -5. THERE HAVE BEEN SOME REPORTS OF MINOR HAIL WITH
THESE STORMS...AND THIS TREND OF PULSING STORMS WITH SMALL HAIL
WILL LIKELY CONTINUE FOR AT LEAST THE NEAR FUTURE. WHILE THE
UPDATES PULLED SOME EMPHASIS OF PCPN FROM THE SOUTHERN FA...WILL
NEED TO KEEP AN EYE ON A BOUNDARY STRETCHING FROM ABOUT HINCKLEY
TO NORTHERN CASS COUNTY THAT IS MOVING TO THE SOUTHWEST. SINCE
THERE IS GREATER INSTABILITY ACROSS THE SOUTHWESTERN FA...WILL
NEED TO SEE IF THIS BOUNDARY BECOMES A TRIGGER FOR STORMS. ONLY
MADE MINOR CHANGES TO THE TEMPERATURES AND WINDS.
PREV DISCUSSION... /ISSUED 331 AM CDT MON APR 2 2012/
SHORT TERM...RUC ANALYSIS DOING GOOD JOB HIGHLIGHTING GENESIS
REGION OF CONVECTION THIS MORNING OVER WCTRL MN. MID LVL
INSTABILITY AXIS IS ALIGNED EAST ACROSS CWA FROM CASS LAKE TO TWIN
PORTS AND THEN SE TO NRN PRICE COUNTY. CONVECTION HAS TRAINED
ALONG THIS CORRIDOR WITH SMALL HAIL REPORTED AT TIMES. A
SECONDARY 70H THETAE MAX IS DEVELOPING ACROSS SRN KOOCH/NRN ITASCA
VICINITY AND NEW CONVECTION IS FORMING THERE AS WELL. AREA REMAINS
UNDER MID LVL RIDGE AXIS WITH A WEAK SHORTWAVE TROF LIFTING OVER
RIDGE AXIS.
TODAY...USED RUC AS SHORT TERM GUIDANCE FOR PLACING HIGHER POPS
ALONG AFOREMENTIONED INSTABILITY AXIS AS IT MOVES GRADUALLY NORTH
THIS MORNING. BY MIDDAY FOCUS OF CONVECTION MAY BE ALIGNED FROM
NWRN CWA TO NR ST LOUIS COUNTY AND THEN SE TO ERN WISC ZONES.
SMALL HAIL STILL POSSIBLE WITH SOME STORMS. AT THAT TIME... 85H
MSTR TRANSPORT AXIS IS FCST TO STRETCH FROM ST CROIX VALLEY TO
KOOCH COUNTY. WARM ADVECTION AT MID LVLS WILL TEND TO INHIBIT MOST
OF THE ACTIVITY ACROSS THE SRN CWA BY 18Z. WE SHOULD SEE A WELL
DEVELOPED BAND OF RAIN/THUNDERSTORMS FROM SE NDAK INTO NWRN MN.
THIS WILL BE OCCURRING ON NWRN SIDE OF SFC LOW IN AN AREA OF
DIVERGENCE ALOFT SUPPLIED BY RIGHT ENTRANCE REGION OF UPPER
JET.THIS CORRIDOR OF DEEP LAYER LIFT WILL TEND TO REMAIN OVER THE
SAME REGION THROUGH THE AFTERNOON. SIGNIFICANT RAINFALL MAY OCCUR
AND WE WILL NEED TO WATCH KOOCH/NWRN ITASCA COUNTY AREA FOR
ADDITIONAL UPDATES.
TONIGHT/TOMORROW...NRN BRANCH OF WESTERLIES WILL ADVANCE ACROSS CWA
OVERNIGHT. THIS WILL PUSH FRNTL SYSTEM THROUGH AS SFC HIGH BUILDS
INTO CWA FROM NRN PLAINS. DEEP LAYER DRYING REFLECTED IN
INTEGRATED RH PRODUCTS AND MDL XSECTS. SHOULD SEE MOSTLY SUNNY
SKIES ADVANCING ACROSS CWA AS DAY UNFOLDS. WITH INCREASED MIXING
DURING DAY...UNIDIRECTIONAL FLOW IN LOWEST 5K FT....SHOULD SEE
SOME GUSTY WINDS DEVELOPING. SFC DEWPOINTS MAY NEED LOWERING AS
MIX DOWN OF DRIER AIR OCCURS IN AFTN.
EXTENDED...TUESDAY NIGHT THROUGH SUNDAY...
UPPER LEVEL AND SFC RIDGING WILL COVER THE FA TUESDAY NIGHT THROUGH
FRIDAY. THE RIDGING MOVES JUST E OF THE AREA FRIDAY AFTERNOON
ALLOWING FOR A SOUTHERLY WAA/RETURN FLOW PATTERN TO BECOME
ESTABLISHED. A SHORT WAVE TROF WILL MOVE FROM THE NORTHERN PLAINS
FRIDAY NIGHT INTO THE GREAT LAKES SATURDAY NIGHT. IN THE
MEANTIME...AN ASSOCIATED SFC LOW MOVING THROUGH SOUTHERN CANADA WILL
PUSH A COLD FRONT THROUGH THE FA AND EXIT SATURDAY NIGHT. THIS
COMBINATION WARRANTS SOME POPS FRIDAY NIGHT THROUGH SUNDAY. BEST
INSTABILITY WILL BE FOUND OVER THE SOUTHERN THIRD OF THE AREA
SATURDAY AND HAVE A MENTION OF THUNDERSTORMS.
&&
.POINT TEMPS/POPS...
DLH 52 40 58 35 / 30 60 10 0
INL 52 36 58 30 / 60 60 10 0
BRD 63 41 61 34 / 40 60 10 0
HYR 63 42 61 33 / 10 60 20 0
ASX 58 41 57 34 / 30 60 20 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM....EOM
AVIATION...EOM
AREA FORECAST DISCUSSION
NWS JACKSON MS
457 PM CDT MON APR 2 2012
.UPDATE...HAVE EXPANDED THE AREAL COVERAGE OF SVR WATCH 128 TO
INCLUDE THE AREA FROM GRENADA TO KEMPER AND POINTS SWWD AS THE LINE
OF SEVERE STORMS CONTINUES TO TRACK TO THE NE THIS EVENING.
LOCATIONS IN THE EXPANDED AREA ARE IN A REGION OF PRESSURE FALLS AND
-4 TO -5 LIFTED INDICES. ALSO CLEARED A FEW COUNTIES FROM THE WATCH
OVER SWRN ZONES IN THE STRATIFORM RAIN SHIELD BEHIND THE LINE.
&&
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...COMPLICATED FORECAST
IN THE SHORT TERM AS SEVERAL POTENTIAL ROUNDS OF STORMS WILL BE
POSSIBLE OVER THE NEXT FEW DAYS.
CURRENT RADARS SHOW BROKEN LINE OF SHOWERS AND THUNDERSTORMS MOVING
NORTHWARD THROUGH THE CWA...GENERALLY FROM BASTROP TO THE JACKSON
METRO AREA TO JUST NORTH OF HATTIESBURG. THERE ARE ALSO SOME STORMS
BEHIND THIS LINE MOVING NORTH FROM PIKE AND AMITE COUNTIES IN
LOUISIANA. THIS MAIN LINE IS PRODUCING SEVERE WIND DAMAGE WITH MOST
REPORTS BEING TREES COMING DOWN AND SOME QUARTER SIZE HAIL AS IT
CONTINUES NORTH THROUGH AN UNSTABLE ATMOSPHERE CHARACTERIZED BY
3500-4000 J/KG SBCAPE...2000-2600 J/KG MLCAPE...28-29C VERTICAL
TOTALS...AND -8 TO -12 SFC LI PER RUC ANALYSIS. THIS UNSTABLE
AIRMASS HAS HELPED TO SUSTAIN THE SEVERITY OF THE LINE OF STORMS AS
IT MOVED OUT OF THE LAKE CHARLES LOUISIANA AREA EARLIER THIS
MORNING. THIS LINE IS EXPECTED TO REMAIN SEVERE AS IT CONTINUES TO
THE NORTH AND EAST UNTIL DAYTIME HEATING IS ABLE TO REDUCE
INSTABILITY OVER THE AREA. SEVERE THUNDERSTORM WATCH CONTINUES FOR
PORTIONS OF THE AREA...AND WAS EVEN EXPANDED TO INCLUDE MORE OF THE
PINE BELT REGION THROUGH 8PM.
HI-RES WRF MODELS AS WELL AS GLOBAL MODELS INDICATE THAT THIS
ACTIVITY WILL BE WANING THROUGH THE EVENING AND OVERNIGHT AS
INSTABILITY WANES AND THE SHORTWAVE TROUGH LIFTS OFF TO THE NORTH.
THERE IS SOME POTENTIAL FOR PATCHY FOG TONIGHT SOUTH OF I-20 AS
MOISTURE CONTINUES TO BUILD INTO THE REGION AND WINDS DIMINISH LATER
IN THE NIGHT.
FOR TUESDAY...THERE REMAINS SOME UNCERTAINTY AS TO HOW STORMS WILL
EVOLVE. MODELS SHOW SHORTWAVE RIDGING MOVING INTO THE AREA...WHICH
SHOULD SUPPRESS MOST CONVECTION. IN ADDITION...THERE IS SOME CONCERN
AS TO HOW THE SYSTEM GOING THROUGH TODAY WILL POTENTIALLY AFFECT
TOMORROW. THERE WILL BE ENOUGH INSTABILITY AS TEMPERATURES REACH
INTO THE 80S ONCE AGAIN. MUCAPE VALUES ARE PROGGED TO BE AROUND
1800-2000J/KG...28-29C VERTICAL TOTALS...BUT WIND SHEAR WILL AGAIN
BE RATHER WEAK AS WELL AS MID LEVEL FLOW. WHATEVER BOUNDARIES THIS
SYSTEM TODAY LEAVES AROUND COULD BE A FOCUS FOR ANY ADDITIONAL
SHOWERS AND THUNDERSTORMS TOMORROW. GIVEN THE WEAK FLOW...THESE
STORMS WOULD BE OF PULSE TYPE VARIETY. HAVE GONE WITH SLIGHT CHANCE
POPS FOR TOMORROW GIVEN UNCERTAINTY IN STORM COVERAGE.
THE BETTER POTENTIAL FOR SHOWERS AND STORMS STILL LOOKS TO BE ON
WEDNESDAY. THERE STILL REMAINS UNCERTAINTY IN TIMING AND HOW MUCH
COVERAGE WE WILL SEE. HOWEVER...PARAMETERS LOOK BETTER IN TERMS OF
WIND SHEAR...MID LEVEL FLOW...LAPSE RATES THAN THEY HAVE FOR THE
PREVIOUS DAYS. WHILE VALUES OF SHEAR ARE STILL NOT OVERLY IMPRESSIVE
WHICH COULD PRECLUDE ORGANIZED THUNDERSTORM ACTIVITY...GIVEN THE
FORCING AND LIFT FROM THE UPPER LOW TRACKING CLOSER...WE COULD SEE
ADDITIONAL STRONG TO SEVERE STORMS AND WILL CONTINUE TO MENTION THIS
IN THE HWO/GRAPHICS. THE BEST LIFT SHOULD CONTINUE TO MOVE EAST OF
THE AREA BY THURSDAY MORNING...AND END MOST OF THE THUNDERSTORM
ACTIVITY. /28/
.LONG TERM...THURSDAY THROUGH MONDAY...DEPENDING ON THE
TRACK OF THE MID LEVEL LOW...THERE COULD BE ENOUGH
INSTABILITY THURSDAY INTO THURSDAY NIGHT TO GET REDEVELOPMENT OF
MOSTLY DIURNAL SHOWER/ISOLATED THUNDERSTORM ACTIVITY...PARTICULARLY
OVER NE PORTIONS OF THE FORECAST AREA. OTHERWISE...IN THE WAKE OF
THE DEPARTING LOW...EXPECT THE STUBBORN MID LEVEL RIDGE TO REBUILD
OVER THE FORECAST AREA AS WE GO INTO NEXT WEEKEND RESULTING IN MORE
WARM AND DRY CONDITIONS. /EC/
&&
.AVIATION...VFR CONDITIONS ONGOING THIS AFTERNOON BUT SHOWERS AND
THUNDERSTORMS MOVING NORTH THROUGH THE AREA BRINGING LOCALIZED MVFR
TO IFR CONDITIONS FOR LOW CEILINGS AND VIS. THESE STORMS BRINGING
GUSTY WINDS UP TO 60 MPH AND POTENTIAL FOR LARGE HAIL TO GOLFBALL
SIZE. THE RISK FOR THUNDERSTORMS AND RAIN WILL WANE THROUGH THE
EVENING AFTER 01-02Z. AREAS OF MVFR/IFR STRATUS/FOG WILL REDEVELOP
AGAIN LATE TONIGHT INTO EARLY TUESDAY MORNING BEFORE DISSIPATING
AFTER ABOUT 15Z TUESDAY. /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 62 85 65 82 / 51 20 22 55
MERIDIAN 61 87 61 81 / 43 23 12 46
VICKSBURG 62 86 64 82 / 40 16 33 58
HATTIESBURG 64 88 65 83 / 41 17 18 50
NATCHEZ 64 85 66 83 / 21 16 38 63
GREENVILLE 64 85 65 85 / 51 17 44 55
GREENWOOD 65 85 66 84 / 46 23 36 55
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
28/EC/03
AREA FORECAST DISCUSSION
NWS JACKSON MS
410 PM CDT MON APR 2 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...COMPLICATED FORECAST
IN THE SHORT TERM AS SEVERAL POTENTIAL ROUNDS OF STORMS WILL BE
POSSIBLE OVER THE NEXT FEW DAYS.
CURRENT RADARS SHOW BROKEN LINE OF SHOWERS AND THUNDERSTORMS MOVING
NORTHWARD THROUGH THE CWA...GENERALLY FROM BASTROP TO THE JACKSON
METRO AREA TO JUST NORTH OF HATTIESBURG. THERE ARE ALSO SOME STORMS
BEHIND THIS LINE MOVING NORTH FROM PIKE AND AMITE COUNTIES IN
LOUISIANA. THIS MAIN LINE IS PRODUCING SEVERE WIND DAMAGE WITH MOST
REPORTS BEING TREES COMING DOWN AND SOME QUARTER SIZE HAIL AS IT
CONTINUES NORTH THROUGH AN UNSTABLE ATMOSPHERE CHARACTERIZED BY
3500-4000 J/KG SBCAPE...2000-2600 J/KG MLCAPE...28-29C VERTICAL
TOTALS...AND -8 TO -12 SFC LI PER RUC ANALYSIS. THIS UNSTABLE
AIRMASS HAS HELPED TO SUSTAIN THE SEVERITY OF THE LINE OF STORMS AS
IT MOVED OUT OF THE LAKE CHARLES LOUISIANA AREA EARLIER THIS
MORNING. THIS LINE IS EXPECTED TO REMAIN SEVERE AS IT CONTINUES TO
THE NORTH AND EAST UNTIL DAYTIME HEATING IS ABLE TO REDUCE
INSTABILITY OVER THE AREA. SEVERE THUNDERSTORM WATCH CONTINUES FOR
PORTIONS OF THE AREA...AND WAS EVEN EXPANDED TO INCLUDE MORE OF THE
PINE BELT REGION THROUGH 8PM.
HI-RES WRF MODELS AS WELL AS GLOBAL MODELS INDICATE THAT THIS
ACTIVITY WILL BE WANING THROUGH THE EVENING AND OVERNIGHT AS
INSTABILITY WANES AND THE SHORTWAVE TROUGH LIFTS OFF TO THE NORTH.
THERE IS SOME POTENTIAL FOR PATCHY FOG TONIGHT SOUTH OF I-20 AS
MOISTURE CONTINUES TO BUILD INTO THE REGION AND WINDS DIMINISH LATER
IN THE NIGHT.
FOR TUESDAY...THERE REMAINS SOME UNCERTAINTY AS TO HOW STORMS WILL
EVOLVE. MODELS SHOW SHORTWAVE RIDGING MOVING INTO THE AREA...WHICH
SHOULD SUPPRESS MOST CONVECTION. IN ADDITION...THERE IS SOME CONCERN
AS TO HOW THE SYSTEM GOING THROUGH TODAY WILL POTENTIALLY AFFECT
TOMORROW. THERE WILL BE ENOUGH INSTABILITY AS TEMPERATURES REACH
INTO THE 80S ONCE AGAIN. MUCAPE VALUES ARE PROGGED TO BE AROUND
1800-2000J/KG...28-29C VERTICAL TOTALS...BUT WIND SHEAR WILL AGAIN
BE RATHER WEAK AS WELL AS MID LEVEL FLOW. WHATEVER BOUNDARIES THIS
SYSTEM TODAY LEAVES AROUND COULD BE A FOCUS FOR ANY ADDITIONAL
SHOWERS AND THUNDERSTORMS TOMORROW. GIVEN THE WEAK FLOW...THESE
STORMS WOULD BE OF PULSE TYPE VARIETY. HAVE GONE WITH SLIGHT CHANCE
POPS FOR TOMORROW GIVEN UNCERTAINTY IN STORM COVERAGE.
THE BETTER POTENTIAL FOR SHOWERS AND STORMS STILL LOOKS TO BE ON
WEDNESDAY. THERE STILL REMAINS UNCERTAINTY IN TIMING AND HOW MUCH
COVERAGE WE WILL SEE. HOWEVER...PARAMETERS LOOK BETTER IN TERMS OF
WIND SHEAR...MID LEVEL FLOW...LAPSE RATES THAN THEY HAVE FOR THE
PREVIOUS DAYS. WHILE VALUES OF SHEAR ARE STILL NOT OVERLY IMPRESSIVE
WHICH COULD PRECLUDE ORGANIZED THUNDERSTORM ACTIVITY...GIVEN THE
FORCING AND LIFT FROM THE UPPER LOW TRACKING CLOSER...WE COULD SEE
ADDITIONAL STRONG TO SEVERE STORMS AND WILL CONTINUE TO MENTION THIS
IN THE HWO/GRAPHICS. THE BEST LIFT SHOULD CONTINUE TO MOVE EAST OF
THE AREA BY THURSDAY MORNING...AND END MOST OF THE THUNDERSTORM
ACTIVITY. /28/
.LONG TERM...THURSDAY THROUGH MONDAY...DEPENDING ON THE
TRACK OF THE MID LEVEL LOW...THERE COULD BE ENOUGH
INSTABILITY THURSDAY INTO THURSDAY NIGHT TO GET REDEVELOPMENT OF
MOSTLY DIURNAL SHOWER/ISOLATED THUNDERSTORM ACTIVITY...PARTICULARLY
OVER NE PORTIONS OF THE FORECAST AREA. OTHERWISE...IN THE WAKE OF
THE DEPARTING LOW...EXPECT THE STUBBORN MID LEVEL RIDGE TO REBUILD
OVER THE FORECAST AREA AS WE GO INTO NEXT WEEKEND RESULTING IN MORE
WARM AND DRY CONDITIONS. /EC/
&&
.AVIATION...VFR CONDITIONS ONGOING THIS AFTERNOON BUT SHOWERS AND
THUNDERSTORMS MOVING NORTH THROUGH THE AREA BRINGING LOCALIZED MVFR
TO IFR CONDITIONS FOR LOW CEILINGS AND VIS. THESE STORMS BRINGING
GUSTY WINDS UP TO 60 MPH AND POTENTIAL FOR LARGE HAIL TO GOLFBALL
SIZE. THE RISK FOR THUNDERSTORMS AND RAIN WILL WANE THROUGH THE
EVENING AFTER 01-02Z. AREAS OF MVFR/IFR STRATUS/FOG WILL REDEVELOP
AGAIN LATE TONIGHT INTO EARLY TUESDAY MORNING BEFORE DISSIPATING
AFTER ABOUT 15Z TUESDAY. /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 62 85 65 82 / 51 20 22 55
MERIDIAN 61 87 61 81 / 43 23 12 46
VICKSBURG 62 86 64 82 / 40 16 33 58
HATTIESBURG 64 88 65 83 / 41 17 18 50
NATCHEZ 64 85 66 83 / 21 16 38 63
GREENVILLE 64 85 65 85 / 51 17 44 55
GREENWOOD 65 85 66 84 / 46 23 36 55
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
28/EC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
448 PM CDT MON APR 2 2012
.UPDATE...
SFC LOW PRESSURE APPEARS TO BE TRACKING TOO CLOSE TO EASTERN
PORTIONS OF NCNTL NEB FOR STRONG WINDS TO DEVELOP. SO THAT PORTION
OF THE WIND ADZY HAS BEEN CANCELLED. NEITHER THE RUC NOR THE HRRR
INDICATE 45 MPH GUST BECOMING WIDESPREAD.
&&
.PREV DISCUSSION... /ISSUED 315 PM CDT MON APR 2 2012/
DISCUSSION...
A DECISION MAY NEED TO BE MADE ON WHETHER TO CONTINUE THE WIND
ADVISORY ALONG HWY 281. THE MODELS ARE TRACKING THE SFC LOW FAR
ENOUGH WEST TO PERHAPS PREVENT STRONG WINDS FROM DEVELOPING IN
THAT REGION. OTHERWISE THE HIGH WIND WARNING CAN CONTINUE
OPERATING ACROSS PARTS OF WRN NEB. HIGH WINDS MIGHT DEVELOP
EASTWARD UNTIL 00Z AS MERRIMAN PROFILER SHOWS 2 GATES OF 55KT AT
19Z. WITH CYCLOGENESIS DEVELOPING TONIGHT ACROSS TX AND THE MODELS
INDICATING REDEVELOPMENT OF STRATUS ACROSS THE FCST AREA...WIND
ADVISORY CONDITIONS ARE EXPECTED TO CONTINUE OVERNIGHT ACROSS
PARTS OF SWRN NEB.
AN UPPER LEVEL LOW DEVELOPING ACROSS ERN NM/NW TEXAS TONIGHT IS
EXPECTED TO SHOOT A BAND OF WARM AIR ADVECTION DRIVEN SHOWERS NORTHWARD
INTO SRN NEB. THE MODELS INDICATE THIS BAND OF SHOWERS WILL FALL
APART FAIRLY QUICKLY AS IT MOVES NORTH. A MORE SUBSTANTIAL BAND OF
SHOWERS SHOULD DEVELOP TUESDAY NIGHT WHICH IS PROGGED TO SWEEP
INTO PARTS OF WRN AND NCNTL NEB PRODUCING AROUND 1/2 TO 3/4 OF AN
INCH OF RAIN ON WEDNESDAY. THE GFS APPEARS TO SUFFERING QPF FEEDBACK
PROBLEMS. TIME HEIGHTS SHOW 20 UBARS OF LIFT EXTENDING UPWARD TO
OVER 500 MB AND THE QPF LOOKS OVERDONE. A 4-WAY BLEND OF
NAM...GEM...ECM AND GFS WAS USED AS A BASIS FOR QPF AND POPS WHICH
SUGGESTED DEFINITE RAIN CHANCES WEDNESDAY.
THE STORM SYSTEM SHOULD CLEAR THE FCST AREA LATE WEDNESDAY NIGHT
WITH CLEARING SKIES ON THURSDAY. THEREAFTER A PERIOD OF WARM AIR
ADVECTION DEVELOPS FRIDAY AHEAD OF A DEEP UPPER LEVEL TROF
SITUATED ACROSS THE WRN U.S.. STRATUS AND SHOWERS ARE POSSIBLE
EARLY FRIDAY MORNING. A STRONG DISTURBANCE WILL LIFT THROUGH THE
NRN HIGH PLAINS FRIDAY AFTN AND FRIDAY NIGHT. TSTMS ARE POSSIBLE
ACROSS NORTHERN PORTIONS OF THE FCST AREA AS THIS DISTURBANCE LIFT
THROUGH THE PLAINS. A PV15 ANOMALY WILL BE OPERATING IN TANDEM
WITH THE DISTURBANCE AND A DRYLINE BULGE SHOULD DEVELOP FOLLOWED
BY A STRONG PACIFIC COLD FRONT.
HIGH PRESSURE AND COOL WEATHER IS EXPECTED SATURDAY THROUGH MONDAY
WITH HIGHS IN THE 50S TO LOWER 60S.
AVIATION...
WIND SPEEDS ARE EXPECTED TO DECREASE THIS EVENING...HOWEVER GUSTS
ARE EXPECTED TO STAY AT OR ABOVE 25KTS THROUGH THE OVERNIGHT HOURS
AND MUCH OF TUESDAY MORNING. LOCATIONS ACROSS SOUTHWEST INTO CENTRAL
NEBRASKA /FROM KOGA TO KTIF TO KONL/ WILL SEE THE HIGHER WINDS
PERSIST THE LONGEST...WITH GUSTS OVER 30KTS.
MODELS INDICATE LOW LEVEL MOISTURE WILL INCREASE THIS EVENING
LEADING TO FURTHER DEVELOPMENT OF STRATUS AND MVFR CEILINGS. THERE
ARE MIXED SIGNALS ON THE HEIGHT OF THIS CLOUD LAYER. SO ALTHOUGH
FAIRLY CONFIDENT ON STRATUS ACROSS THE AREA...DO HAVE A CONSIDERATE
AMOUNT OF UNCERTAINTY ON THE CLOUD HEIGHT. NAM WOULD SAY IFR
CEILINGS WHILE OTHER SOLUTIONS WOULD ACTUALLY RAISE THE CEILINGS TO
ABOUT 5K FEET. AT THIS TIME...KEPT A STABLE FORECAST WITH CEILINGS
AT BOTH KVTN AND KLBF AT 2500 FT THROUGH TUESDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY UNTIL 7 AM CDT
/6 AM MDT/ TUESDAY FOR NEZ057-058-069-070.
WIND ADVISORY UNTIL 10 PM CDT /9 PM MDT/ THIS EVENING FOR NEZ005-
006-008-009-024>027-036>038-059.
HIGH WIND WARNING UNTIL 6 PM MDT THIS EVENING FOR NEZ004-022-023-
056-094.
WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR NEZ004-094.
WIND ADVISORY UNTIL 6 AM MDT TUESDAY FOR NEZ056.
WIND ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR NEZ022-023.
WIND ADVISORY UNTIL 1 AM CDT /MIDNIGHT MDT/ TUESDAY FOR NEZ035-
071.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
346 PM CDT MON APR 2 2012
.SHORT TERM...TONIGHT AND TUESDAY. MAIN FORECAST CONCERN WILL BE
CHANCE FOR SHOWERS AND THUNDERSTORMS.
SURFACE ANALYSIS AND SURFACE OBSERVATIONS INDICATE A COLD FRONT
ACROSS THE EASTERN PART OF THE FORECAST AREA THIS AFTERNOON. AHEAD
OF THE COLD FRONT TEMPERATURES HAVE JUMPED AND ARE QUITE WARM.
COOLER TEMPERATURES ARE BEHIND THE FRONT. SATELLITE SHOWS SOME
STRATUS ACROSS THE FAR NORTHERN PART OF THE FORECAST AREA. THIS WAS
SPREADING FURTHER SOUTH THIS MORNING...BUT HAS HELD OFF DURING THE
AFTERNOON.
WINDS HAVE FINALLY STARTED TO INCREASE TO THE WEST AND WILL CONTINUE
TO INCREASE THIS AFTERNOON FOR THE FAR WEST. WILL LEAVE THE WIND
ADVISORY AS IS.
THE POSITION OF THE FRONT IS KEY THIS AFTERNOON FOR THUNDERSTORM
DEVELOPMENT. MODELS HAVE THUNDERSTORMS DEVELOPING ALONG THE FRONT
DURING THE LATE AFTERNOON AND EARLY EVENING. WITH THE CURRENT
LOCATION OF THE FRONT EXPECT THUNDERSTORMS TO BE IN THE SOUTHEAST
PART OF THE FORECAST AREA. THE HRRR KEEPS THE PRECIPITATION IN THE
FAR SOUTHEAST THROUGH THE EVENING WHILE THE NAM AND GFS HAVE IT A
BIT FURTHER TO THE NORTHWEST. THE BEST MUCAPES ARE IN THE FAR
SOUTHEAST PART OF THE FORECAST AREA WITH THE OVER 1000J/KG CAPES FAR
IN THE SOUTHEASTERN PART OF THE FORECAST AREA.
LATER THIS EVENING AND OVERNIGHT AN UPPER LEVEL LOW DEVELOPING ON
THE SOUTHERN HIGH PLAINS STARTS TO DRIFT TO THE NORTH AND PUSHES
PRECIPITATION TO THE NORTH BEHIND THE FRONT. MOST OF THE
PRECIPITATION SHOULD BE IN THE SOUTHERN PART OF THE FORECAST AREA.
THE UPPER LEVEL LOW CONTINUES TO DRIFT THROUGH THE SOUTHERN HIGH
PLAINS ON TUESDAY AND THE CHANCE FOR SHOWERS CONTINUES MAINLY IN THE
SOUTH/SOUTHWEST.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY. PRIMARY FORECAST CONCERN LIES WITH
PRECIPITATION CHANCES EARLY ON IN THE PERIOD.
LOOKING AT THE TIME FRAME STARTING TUESDAY NIGHT AND CONTINUING
THROUGH WEDNESDAY NIGHT...THE MAIN STORY LIES WITH THE IMPACT ACROSS
THE REGION FROM A PASSING UPPER LEVEL LOW PRESSURE SYSTEM AND
ASSOCIATED PRECIPITATION CHANCES. LATEST MODELS RUNS ARE IN PRETTY
GOOD AGREEMENT AT THE START OF THE PERIOD...SHOWING THE LOW CENTERED
OVER THE PANHANDLES OF TX/OK...BUT MORE VARIANCES START TO SHOW UP
THROUGH THE OVERNIGHT HOURS AND INTO WEDNESDAY. THE SYSTEM DOESNT
MAKE A WHOLE LOT OF EASTWARD PROGRESS...WITH A RIDGE AXIS TO THE
EAST EXTENDING FROM THE GULF COAST REGION UP INTO THE ERN
DAKOTAS...AND BY WEDNESDAY EVENING LOOKS TO RANGE IN LOCATION FROM
SC KS TO WRN OK. INCREASED LIFT OUT AHEAD OF THE LOW PRESSURE
SYSTEM WILL HELP WITH THE NORTHWARD SPREAD OF PRECIPITATION FROM THE
SRN PLAINS INTO THE CWA TUESDAY EVENING/OVERNIGHT...WHICH WILL
CONTINUE ON INTO THE DAYTIME HOURS ON WEDNESDAY AS INCREASED LOW/MID
LEVEL FRONTOGENETICAL ON THE NORTHERN SIDE OF THE LOW SHIFTS INTO
THE CWA. DECIDED TO INSERT A MENTION OF ISOLATED THUNDER WED
EVENING...WITH SOME OF THE MODELS/SREF PROBS SHOWING THE POTENTIAL
LINGERING AROUND THE SOUTHEASTERN CORNER OF THE CWA. EXPECTING
PLENTY OF CLOUD COVER AND GENERALLY N/NE WINDS AS THE MAIN SFC LOW
SLIDES TO THE SOUTH OF THE CWA...WITH HIGHS TOPPING OUT IN THE
LOW/MID 50S. MODELS ARE A LITTLE SLOWER THURSDAY EVENING/NIGHT
PUSHING PRECIPITATION CHANCES EAST OF THE CWA AS THE UPPER LEVEL LOW
MAKES ITS WAY TOWARD THE MO RIVER...AND PUSHED POPS BACK WEST TO
INCLUDE ALL COUNTIES.
UPPER LEVEL SHORTWAVE RIDGING BUILDING INTO THE PLAINS IN THE WAKE
OF THIS LATEST SYSTEM IS EXPECTED TO KEEP THURSDAY AND THURSDAY
NIGHT DRY. SEE A SLIGHT BUMP IN HIGHS BUT TEMPS REMAIN ON THE
RELATIVELY COOL SIDE /COMPARED TO THE LAST FEW DAYS...BUT STILL NEAR
OR ABOVE AVG/...WITH THE CWA REMAINING ON THE WRN/SRN FRINGE OF SFC
HIGH PRESSURE OVER THE WRN GREAT LAKES...AND AM EXPECTING LOWER 60S.
NEXT CHANCE FOR PRECIPITATION IS EXPECTED TO COME TO WESTERN
PORTIONS OF THE CWA DURING THE DAY ON FRIDAY AND EXPAND FURTHER EAST
FRIDAY NIGHT...AS ANOTHER SHORTWAVE TROUGH AXIS LOOKS TO SWING
THROUGH THE NORTHERN/CENTRAL PLAINS. MODELS VARY SOME THROUGH THIS
TIMEFRAME...WITH THE GFS SHOWING THIS ENERGY ASSOCIATED WITH AN
ELONGATED LOW OVER WRN/CENTRAL CANADA...WHILE THE EC SHOWS ANY LOW
LOCATED OFF THE PAC NW COAST. KEPT THE HIGHER POPS ACROSS THE NORTH
WHERE THERE IS BETTER AGREEMENT BETWEEN THE MODELS...BUT POPS GO ALL
THE WAY SOUTH TROUGH THE CWA WITH THE GFS CONTINUING TO SHOW MORE
COVERAGE. THE MAIN INSTABILITY AXIS LOOKS TO SET UP JUST WEST OF
THE CWA DURING THE DAY...AND PUSH THROUGH DURING THE OVERNIGHT
HOURS...WITH MUCAPE VALUES UPWARDS OF 7-800 J/KG...SO THREAT OF SOME
STRONG STORMS WILL REMAIN...BUT WILL CONTINUE TO KEEP AN EYE ON THE
POTENTIAL FOR SEVERE STORMS.
KEPT THE FORECAST FOR THE UPCOMING WEEKEND AND INTO MONDAY
DRY...THOUGH THE GFS TRIES TO LINGER SOME POPS IN THE EAST EARLY ON
SAT MORNING. AN ACCOMPANYING SURFACE COLD FRONT IS EXPECTED TO BE ON
ITS WAY THROUGH THE CWA SATURDAY MORNING...BUT MODELS DO VARY SOME
ON THE TIMING. EC IS ON THE QUICKER SIDE...WITH THE FRONT CLEARING
THE CWA SAT MORNING...WHILE THE GFS WOULD BE MORE INTO THE
AFTERNOON. LOOKS TO BE BREEZY DAY ON SATURDAY...WITH NORTHWEST
WINDS PICKING UP BEHIND THE FRONT. MORE ZONAL/NORTHWESTERLY FLOW
SETS UP IN THE UPPER LEVELS FOR SUN/MON WITH A RIDGE SET UP OVER THE
SRN/SWRN CONUS...WITH NO NOTABLE SYSTEM LOOKING TO PASS THROUGH.
BEHIND THE SFC FRONT...HIGH PRESSURE BUILDS IN AND IS THE DOMINANT
FEATURE ON SUNDAY...BRINGING A PLEASANT WITH LIGHT WINDS AND HIGHS
TOPPING OUT IN THE LOWER/MID 60S. MONDAY COULD SEE AN INCREASE IN
WINDS DEPENDING ON THE MODEL...BUT STILL EXPECTING ANOTHER NICE DAY
WITH HIGHS SIMILAR TO SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 1234 PM CDT MON APR 2 2012/
AVIATION...18Z TAF. A COLD FRONT IS NEARLY ON TOP OF THE KGRI
TERMINAL AT THIS TIME AND WILL CONTINUE TO MOVE TO THE EAST. THIS
WILL TURN THE WINDS TO THE NORTH AND INCREASE THEM THROUGH THE
AFTERNOON AND EVENING. THE WINDS WILL WEAKEN THIS EVENING A
LITTLE...BUT EXPECT THAT THEY WILL CONTINUE THROUGH THE NIGHT.
THERE IS A LITTLE CHANCE THERE WILL BE SOME SHOWERS AROUND THE
AREA BUT DO NOT EXPECT A LOT. THERE WILL BE SOME MVFR CEILINGS
LATE TONIGHT INTO TUESDAY MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR NEZ039-046-060-
061-072-073-082-083.
KS...WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR KSZ005-017.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
336 PM CDT MON APR 2 2012
.DISCUSSION...
THE SHORT TERM CONCERNS WILL BE THE POTENTIAL FOR THUNDERSTORMS
AND SEVERE WEATHER AND IF A WIND ADVISORY WILL BE NEEDED.
AT 20Z...THE COLD FRONT HAD FINALLY MADE IT INTO NORFOLK AND THEIR
TEMPERATURES WERE BEGINNING TO FALL. AHEAD OF THE
FRONT...TEMPERATURES TOPPED OUT IN THE 80S TO LOWER 90S. THE LOW
CLOUDS HAD MADE IT INTO THE THE ONEILL AREA AND TEMPERATURES WERE
ONLY IN THE 50S. WINDS IN THE WEST CENTRAL PART OF NEBRASKA WERE
QUITE STRONG WITH GUSTS IN THE 40 TO 50 MPH IN SPOTS.
TONIGHT...THE SURFACE COLD FRONT WILL BE MOVING ACROSS THE REST OF
EASTERN NEBRASKA AND SOUTHWEST IOWA. THE HIGHER UPPER 50S AND
LOWER 60S DEGREE DEWPOINTS AT 20Z EXTENDED FROM BEATRICE TO OMAHA
AND THESE WILL SHIFT EASTWARD WITH TIME. THE 4KM WRF HAD
THUNDERSTORMS ALONG THE FRONT...WHILE THE 18Z NAM WAS DRY...THE
LATEST RUC HAD SOME STORMS DEVELOPING TOWARD FAIRBURY AND THE GFS
HAD AN AREA SIMILAR TO THE 4KM WRF...BUT SHIFTED FARTHER SOUTHEAST
AND MAINLY ALONG AND SOUTH OF I80. THERE IS THE POTENTIAL
FOR THUNDERSTORMS THIS EVENING AHEAD OF AND ALONG THE FRONT AND
WILL MAINTAIN ISOLATED TO SCATTERED THUNDERSTORM CHANCES MAINLY
ALONG AND SOUTH OF I80. THE ATMOSPHERE HAS GOOD INSTABILITY AND
STEEP LAPSE RATES TO WORK WITH...HOWEVER THE SHEAR PARAMETERS DO
NOT APPEAR AS FAVORABLE IN THIS AREA. SPC HAS A SLIGHT RISK AND
THE SLIGHT RISK APPEARS WARRANTED BASED ON CONDITIONAL FACTORS AS
SHOULD THUNDERSTORMS GET GOING THEY COULD CONTAIN SOME HAIL AND
DAMAGING WINDS. BEHIND THE FRONT...ESPECIALLY ACROSS NORTHEAST
NEBRASKA THE WINDS WILL BE STRONG. AT THIS TIME WILL HAVE WINDY
CONDITIONS AT 20 TO 30 MPH WITH GUSTS TO 45...BUT HAVE NOT GONE
WITH A WIND ADVISORY AT THIS TIME. BEHIND THE FRONT...WITH THE LOW
CLOUDS THERE MAY BE SOME SHOWERS IN NORTHEAST NEBRASKA AND SOME OF
THESE MAY LINGER INTO TUESDAY.
THE SOUTHERN ENERGY WITH THIS STORM SYSTEM WILL CLOSE OFF AND LIFT
NORTH. THIS WILL RETURN THE CHANCE FOR SHOWERS AND THUNDERSTORMS
TUESDAY NIGHT AND WEDNESDAY AND WEDNESDAY NIGHT AND THEN MOVE OUT
THURSDAY.
THURSDAY NIGHT THROUGH MONDAY....THE STORM SYSTEM THAT WILL
AFFECT US FOR MUCH OF THE WEEK WILL BE OVER SOUTHERN MISSOURI AT
THE START OF THE EXTENDED WITH DRY CONDITIONS...SOUTHEAST BREEZES
AND COMFORTABLE TEMPERATURES IN THE 60S FRIDAY. FRIDAY NIGHT...THE
TROF OVER THE PACIFIC NORTHWEST WILL PUSH FAR ENOUGH EASTWARD TO
PUSH TO FRONT INTO PARTS OF EASTERN NEBRASKA BY 12Z SATURDAY.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AHEAD OF AND ALONG THE
COLD FRONT FRIDAY NIGHT AND SATURDAY. AS THIS SYSTEM MOVES OUT OF
THE AREA...MID LEVEL RIDGING BUILDS IN AND DRY WEATHER AND MORE
SEASONABLE WEATHER IS FORECAST FOR SATURDAY AND SUNDAY.
&&
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
COLD FRONT WILL BE CROSSING ERN NEBRASKA LATER THIS AFTERNOON
THROUGH EARLY EVENING WITH SOME RISK OF CONVECTION ALONG
IT...ESPECIALLY SW OF KLNK. ANY ACTIVITY THAT
DEVELOPS...HOWEVER...WILL MOVE NORTHEAST TOWARD KLNK AND KOMA. DID
NOT MENTION TSTM IN 18Z TAF...ALTHOUGH SOME POP/TEMPO GROUP WITH
CB WAS INCLUDED. MVFR CIGS SHOULD SPREAD IN BEHIND
FRONT...ALTHOUGH DAYTIME HEATING COULD RESTRICT THEIR SE MOVEMENT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY/CHERMOK
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1234 PM CDT MON APR 2 2012
.AVIATION...18Z TAF. A COLD FRONT IS NEARLY ON TOP OF THE KGRI
TERMINAL AT THIS TIME AND WILL CONTINUE TO MOVE TO THE EAST. THIS
WILL TURN THE WINDS TO THE NORTH AND INCREASE THEM THROUGH THE
AFTERNOON AND EVENING. THE WINDS WILL WEAKEN THIS EVENING A
LITTLE...BUT EXPECT THAT THEY WILL CONTINUE THROUGH THE NIGHT.
THERE IS A LITTLE CHANCE THERE WILL BE SOME SHOWERS AROUND THE
AREA BUT DO NOT EXPECT A LOT. THERE WILL BE SOME MVFR CEILINGS
LATE TONIGHT INTO TUESDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 419 AM CDT MON APR 2 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT. THE PATTERN ALOFT
REVEALED AN UPPER TROUGH IN THE ROCKIES WITH THE MID/UPPER
CIRCULATION CLOSING OFF NEAR THE FOUR CORNERS REGION. AHEAD OF THIS
SYSTEM...SOUTHWEST FLOW WAS IN PLACE ACROSS THE CENTRAL PLAINS WHILE
UPPER RIDGE HAD SHIFTED EAST OF THE MISSOURI RIVER. AT THE
SURFACE...LOW PRESSURE WAS CENTERED IN FAR NORTHWEST KANSAS...WITH
COOL FRONTAL BOUNDARY EXTENDING FROM VTN TO KSNY...AND DRYLINE
EXTENDED ACROSS EASTERN CO. PRESSURE RISES BEHIND THE FRONT BEHIND
THE FRONT AVERAGED 3-5MB.
THERE HAVE BEEN SOME DISTINCT CHANGES IN FRONTAL TIMING...WINDS AND
POTENTIAL FOR CONVECTION TODAY. SURFACE FRONT STILL ENTERS OUR
WESTERN CWA AROUND 12Z...BUT SLOWS AND STALLS ACROSS OUR SOUTHEAST
CWA AROUND MID AFTERNOON. INSTABILITY PROGS INDICATE MUCAPE AROUND
1500 J/KG IN OUR FAR SOUTHEAST CWA FOR A FEW HOURS WITH HIGHER CAPE
AXIS FARTHER SOUTHEAST AHEAD OF THE BOUNDARY...AND A BRIEF PERIOD OF
EFFECTIVE SHEAR OF 30 TO 40KTS RESIDE ALONG THE BOUNDARY...GENERALLY
BETWEEN 21 AND 00Z. AS THE BOUNDARY STALLS IN OUR SOUTHEAST...CAN
NO LONGER RULE OUT CONVECTIVE POTENTIAL AND A WINDOW OF
OPPORTUNITY FOR SEVERE WEATHER WITH STORMS CAPABLE OF PRODUCING
LARGE HAIL/DAMAGING WINDS. 4KM SPC WRF DEVELOPS CONVECTION ACROSS
OUR SOUTHERN CWA IN VCNTY OF BOUNDARY AND WITH CONTINUING TRENDS
OF FRONT SLOWING DOWN...HAVE RETURNED TSTMS TO FORECAST.
ALSO DUE TO SLOWER FRONTAL PROGRESSION TODAY...THIS ALSO HAS AN
IMPACT ON STRENGTH OF WINDS ACROSS OUR REGION. THE CORRIDOR OF
STRONGEST PRESSURE RISES THIS MORNING SLIDE SOUTH FROM WESTERN
NEBRASKA INTO WESTERN KANSAS AND SFC GRADIENT REMAINS TIGHTEST
ACROSS THE WESTERN HALF OF NEBRASKA INTO NW KANSAS. FRONT DOES NOT
REACH OUR EASTERN AND SOUTHEAST COUNTIES UNTIL THIS AFTERNOON OR
EARLY EVENING AND WINDS WILL INITIALLY BE GUSTY OUT OF THE SOUTH BUT
NOT AT WIND ADVISORY CRITERIA. AS FRONT PUSHES THRU OUR SOUTHEAST
CWA IN THE EVENING...A SECONDARY SURGE OF PRESSURE RISES AND
CORRIDOR OF 40KT MID LEVEL WINDS MOVE THRU BEGINNING GENERALLY
AROUND 00Z AND LINGERING/SPREADING SOUTHWARD UNTIL AROUND
MIDNIGHT. WHAT THIS MEANS IS THAT REACHING WIND ADVISORY CRITERIA
ESPECIALLY IN OUR EAST/SOUTHEAST IS LOOKING LESS LIKELY UNTIL
POTENTIALLY CLOSER TO 00Z WITH SECONDARY SURGE OF FRONT/PRESSURE RISES.
OUR WESTERN COUNTIES WILL STILL STAND A BETTER CHC FOR WIND
ADVISORY CRITERIA BUT IN ESSENCE MAY BE MORE OF A BUFFER TO THE
EVEN HIGHER WINDS ACROSS WESTERN NEBRASKA AND KANSAS. FOR
HEADLINE...OPTIONS ARE TO EITHER CANCEL EASTERN/SOUTHEAST PORTION
OR HOLD OFF ON TIMING UNTIL THE EVENING HOURS. HAVE OPTED TO
REMOVE WIND ADVISORY IN THE EAST AND MAINTAIN A BUFFER IN THE
WEST. LATEST HRRR SUGGESTS STRONGER WINDS COULD HOLD OFF EVEN IN
OUR WEST UNTIL AFTN WHILE THE INITIALLY STRONGER WINDS WILL BE FM
THE SOUTH IN OUR EASTERN COUNTIES.
OTHER CHANGE IN MODELS...WHICH HAS BEEN A GENERAL TREND AS WELL...IS
THE FARTHER NORTH TRACK OF THE UPPER LOW AS IT LIFTS FM THE TX/OK
PANHANDLES TUESDAY. GENERAL CONSENSUS IS THAT LOW WILL LIFT AND
TRACK ACROSS KANSAS TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...AND THE
ECMWF REMAINS SLOWER WITH PROGRESSION WHICH COULD POTENTIALLY LINGER
PCPN CHCS BEYOND WEDNESDAY NIGHT. LATEST TRACK PROMISES TO PROVIDE
A DECENT RAIN EVENT ACROSS THE CENTRAL PLAINS MAINLY FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. POPS HAVE BEEN TRENDED UPWARD INTO
LIKELY CATEGORY...AND SOME DECENT SPRING RAINFALL TOTALS ARE
POSSIBLE WITH PRECIPITABLE WATER VALUES AVERAGING 0.75 TO JUST OVER
AN INCH. HAVE KEPT THUNDER WORDING OUT AS INSTABILITY PARAMETERS
ARE RATHER MEAGER BUT WOULD NOT BE SURPRISED TO SEE AN OUTSIDE
LIGHTNING STRIKE HERE OR THERE...ESPECIALLY IN OUR SOUTHEAST WHERE
MUCAPES ARE NOT ZERO...JUST RATHER LOW.
LONG TERM...THURSDAY THROUGH SUNDAY. PRIMARY FOCUS THROUGH THIS
4-DAY PERIOD IS THE RISK FOR THUNDERSTORMS IN THE FRI-SAT TIME
FRAME...BUT MAINLY CENTERED FRIDAY NIGHT AND NOT EVEN IN LIKELY
POP TERRITORY YET. ALTHOUGH NOT NEARLY AS WARM AS LATELY...HIGH
TEMPS THROUGH THIS PERIOD SHOULD NONETHELESS AVERAGE SOLIDLY IN THE
60S MOST AREAS...OR STILL SLIGHTLY ABOVE NORMAL FOR EARLY APRIL. AS
FOR OVERNIGHT LOWS...WILL HAVE TO KEEP AN EYE OUT AS EARLY AS SAT
NIGHT FOR POSSIBLE FROST POTENTIAL.
STARTING OFF THURSDAY...00Z ECMWF/GFS RUNS ARE IN DECENT AGREEMENT
DEPICTING A DEPARTING MID LEVEL CLOSED LOW GENERALLY WANDERING
SOMEWHERE OVER MO. AT THE SAME TIME...A FAIRLY EXPANSIVE UPSTREAM
TROUGH WILL BE CENTERED OVER THE WESTERN 1/3 OF THE CONUS. AT
LEAST FOR NOW...LEFT THURSDAY DAYTIME DRY...ALTHOUGH THERE ARE
SOME HINTS THAT AT LEAST SOME EASTERN AREAS COULD STILL BE PRONE
TO SOME LINGERING LIGHT RAIN SHOWERS. FOR NOW THOUGH WILL STAY THE
COURSE AND REMAIN TRUE TO THE DRY FCST INITIALIZED BY THE ALLBLEND
MODEL PROCEDURE. FOR HIGH TEMPS...NUDGED DOWN A FEW DEGREES MOST
AREAS GIVEN PREDOMINANT EASTERLY LOW LEVEL FLOW...WITH THE
MAJORITY OF THE CWA IN THE 62-65 RANGE. KEPT THURS NIGHT DRY AS
PRIMARY LOW LEVEL JET AXIS AND RESULTANT FOCUS FOR POSSIBLE
CONVECTION APPEARS TO REMAIN AT LEAST SLIGHTLY WEST OF THE CWA.
FRIDAY/FRIDAY NIGHT...THIS 24 HOUR PERIOD APPEARS TO FEATURE THE
PRIMARY RISK FOR THUNDERSTORMS IN THE LONG TERM...ESPECIALLY ON
FRIDAY NIGHT. DURING THE DAY...SOUTHEAST WINDS WILL PICK UP INTO
BREEZY TERRITORY AS PRESSURES FALL OVER THE HIGH PLAINS...BUT AT
THIS TIME SPEEDS LOOK TO REMAIN BELOW ADVISORY CRITERIA. ALLBLEND
PROCEDURE INTRODUCED A SLIGHT CHANCE OF STORMS DURING THE DAY
ACROSS WESTERN COUNTIES...AND OPTED TO RUN WITH IT...ALTHOUGH
CONFIDENCE IS RATHER LOW GIVEN EXPECTATION OF WEAK FORCING AND
SOME CAPPING...DESPITE THE ECMWF AND GFS BOTH ADVERTISING A
NARROW...FAIRLY WEAK INSTABILITY AXIS SETTING UP NEAR THE
SOUTHERN/WESTERN EDGES OF THE CWA THROUGH THE DAY. IN ALL HONESTY
THOUGH...THESE SLIGHT CHANCES DURING THE DAY ARE ALREADY ON
SOMEWHAT SHAKY GROUND RIGHT OUT OF THE GATE. BETTER
CHANCES...ALTHOUGH STILL ONLY IN THE 30-40 PERCENT RANGE AT THIS
TIME...ARRIVE FRIDAY NIGHT AS FORCING FROM THE LEADING SHORTWAVE
EMANATING FROM THE WESTERN CONUS TROUGH SWINGS ALONG A TRACK FROM
WY/NORTHERN CO ACROSS WESTERN NE INTO SD. ALTHOUGH THIS TAKES THE
BULK OF THE LARGE SCALE FORCING NORTH OF THE CWA...BOTH MODELS
GENERATE QPF...WITH THE GFS ADVERTISING A SURGE OF INSTABILITY
DURING THE NIGHT...WITH MUCAPE VALUES CLIMBING TO AROUND 1500 J/KG
IN THE PRESENCE OF AT LEAST 40KT OF DEEP LAYER SHEAR. FOR NOW WILL
INTRODUCE A STRONG STORM MENTION IN THE HWO...BUT WILL NEED TO
KEEP A CLOSE EYE ON SEVERE POTENTIAL OVER NEXT FEW DAYS.
SATURDAY...MID RANGE MODELS CONTINUE TO AGREE ON THE LARGER SCALE
PATTERN...WITH THE MAIN MID LEVEL WAVE CROSSING THE DAKOTAS TOWARD
MN...WHILE A SURFACE COLD FRONT TRACKS ACROSS THE CWA AND USHERS
IN DRIER/MORE STABLE AIR. ALLBLEND MODEL KEPT SOME TOKEN SLIGHT
POPS ACROSS FAR NORTHEAST AND SOUTHEAST PORTIONS OF THE CWA DURING
THE DAY...AND WILL LET IT RIDE FOR NOW.
SAT NIGHT/SUNDAY...CONFIDENCE IS RATHER HIGH AT THIS TIME RANGE
THAT DRY CONDITIONS WILL PREVAIL IN THE WAKE OF THE DEPARTING
WAVE...ALTHOUGH MODELS START TO DIVERGE ALOFT WITH THE ECMWF
ADVERTISING BROAD WEST-NORTHWEST FLOW WHILE THE GFS IS MORE WEST-
SOUTHWEST. DOWN LOW HOWEVER...THERE IS A DECENT SIGNAL FOR HIGH
PRESSURE TO RULE THE SCENE ON SATURDAY NIGHT WITH FAIRLY LIGHT
WINDS. ALTHOUGH CURRENT FORECAST KEEPS LOWS UP IN THE UPPER 30S-
LOW 40S FOR MOST OF THE CWA...WILL HAVE TO MONITOR FOR THE
POTENTIAL FOR A MORE WIDESPREAD LOW-MID 30S...WHICH COULD AT LEAST
BRING SOME FROST POTENTIAL INTO PLAY. CERTAINLY TOO EARLY AT THIS
TIME TO FORMALLY PUT IT IN THE FORECAST. PEEKING AHEAD A BIT INTO
THE WEEK OF APRIL 9TH...COULD BE A FEW MORE RISKS FOR OVERNIGHT
TEMPS DROPPING DOWN INTO AT LEAST THE FROST POSSIBILITY
RANGE...WHICH IS RIGHT IN LINE WITH CLIMATOLOGY FOR MID APRIL.
AVIATION...06Z KGRI TAF. WIND WILL BE THE BIGGEST FACTOR FOR THIS
FORECAST. EAST TO SOUTHEAST WIND WILL PREVAIL OVERNIGHT AND WILL
CONTINUE TO BE A BIT ON THE BREEZY SIDE. A COLD FRONT WILL MOVE IN
TOWARD MID-MORNING AND WILL SWITCH WIND DIRECTION TO THE NORTH
NORTHWEST AND WILL BECOME VERY GUSTY FROM STRONG HEIGHT
RISES...ESPECIALLY TOWARD EVENING. ANY PRECIPITATION SHOULD HOLD
OFF TO THE SOUTH AND WELL AFTER THE FRONT PASSES THROUGH.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR NEZ061-073-083.
WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR NEZ039-046-060-
072-082.
KS...WIND ADVISORY UNTIL 11 PM CDT THIS EVENING FOR KSZ005-017.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1223 PM CDT MON APR 2 2012
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
COLD FRONT WILL BE CROSSING ERN NEBRASKA LATER THIS AFTERNOON
THROUGH EARLY EVENING WITH SOME RISK OF CONVECTION ALONG
IT...ESPECIALLY SW OF KLNK. ANY ACTIVITY THAT
DEVELOPS...HOWEVER...WILL MOVE NORTHEAST TOWARD KLNK AND KOMA. DID
NOT MENTION TSTM IN 18Z TAF...ALTHOUGH SOME POP/TEMPO GROUP WITH
CB WAS INCLUDED. MVFR CIGS SHOULD SPREAD IN BEHIND
FRONT...ALTHOUGH DAYTIME HEATING COULD RESTRICT THEIR SE MOVEMENT.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 1048 AM CDT MON APR 2 2012/
UPDATE...
UPDATED TO INCREASE HIGHS AHEAD OF FRONT SOME AREAS AND TO
REDUCE/DROP PRECIP CHCS THIS AFTERNOON.
DISCUSSION...
MORNING KOAX SOUNDING SHOWED VERY WARM TEMPERATURE LAYER CENTERED
ON H85 WITH WELL MIXED CAP ABOVE. QUESTION IS WHETHER FRONT CAN
BREAK CAP OVER NEBRASKA AND SOME CONFLICTING INFORMATION FROM
MODELS. LATEST RUC SOUNDING DID TO SOME DEGREE...EVEN IN ECNTRL
SECTIONS...WHILE 00Z GFS WAS MORE RESTRICTED TO SWRN FORECAST
AREA. SHORTER RANGE QPF FORECASTS FROM RUC/HRRR DEVELOPED NO
PRECIP OVER FORECAST AREA THROUGH 00Z WHILE LAST EVENINGS 4KM WRF
DID AS DID THE 06Z NAM/GFS. HOWEVER...12Z NAM REFRAINS FROM
SPREADING PRECIP INTO SRN ZONES UNTIL THIS EVENING. BASED ON
MORNING SOUNDING...FELT ANY CONVECTION THAT MAKES IT INTO
FORECAST AREA WILL EITHER DEVELOP LATE IN THE AFTN ON FRONT OVER
SWRN ZONES OR SW OF NEBRASKA AND THEN ATTEMPT TO BUILD INTO SERN
ZONES THIS EVENING. THUS POPS WERE DROPPED MUCH OF THE AREA N
THROUGH E OF OMA ALONG WITH FAR SERN NEBRASKA THIS AFTN AND
TRIMMED BACK ALL BUT SEVERAL SW COUNTIES FM OMAHA SWWD. ALSO
RAISED MAX TEMPS A BIT IN ERN ZONES BASED ON MORNING SOUNDING AND
BOOSTED WINDS A LITTLE BOTH AHEAD OF AND BEHIND FRONT.
CHERMOK
PREV DISCUSSION... /ISSUED 631 AM CDT MON APR 2 2012/
DISCUSSION...
WV IMAGERY SHOWING FEATURE OF CONCERN...DEEP LONGWAVE TROF...OVER THE
ROCKIES SLOWLY MIGRATING TO THE EAST THIS MORNING WHILE SFC LOW
PRESSURE WAS CENTERED IN NERN CO. MODELS IN DECENT AGREEMENT THAT THE
LONGWAVE TROF WILL FORM INTO A CLOSED LOW OVER THE SRN PLAINS AND
BECOME CUT OFF BY EARLY TUESDAY MORNING...THEN EVENTUALLY LIFTING
ACROSS THE CENTRAL PLAINS EARLY THURSDAY. FOR TODAY...ANTICIPATED
COLD FRONT WILL SWEEP INTO THE CENTRAL PLAINS AS CO SFC LOW TREKS
TOWARD THE MID MS VLY. VARIOUS TIME-SERIES PROGS PUT THE FRONT THRU
THE METRO-AREA SOMETIME EARLY THIS EVENING. PW VALUES AROUND 1.25"
AND KI 35-40 INDICATE ENVIRONMENT WILL BE MOISTURE RICH. THAT...IN
COMBINATION WITH FAVORABLE MUCAPE/EFF SRH/EFF BULK WIND DIFFERENCE
PARAMETERS SUGGEST LATE AFTN/EARLY EVENING SEVERE STORM DEVELOPMENT A
DISTINCT POSSIBILITY...PARTICULARLY AREAS SOUTH OF I-80.
FORTUNATELY...APPEARS THAT TOR THREAT WILL BE MINIMAL DUE TO ML LFC
PROGGED AOA 2200M.
PCPN CHANCES CONTINUE THEN TUESDAY THROUGH THURSDAY MAINLY SOUTH
AS AREA FALLS UNDER INFLUENCE OF CLOSED LOW DYNAMICS TREKKING
ACROSS KS.
OTHERWISE THIS COOLER AIRMASS FILTERING IN THIS WEEK WILL BRING
A NOTICEABLE CHANGE. NEVERTHELESS...NEAR NORMAL MAX TEMPS WILL BE
QUITE ATTAINABLE.
DEE
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
317 PM EDT MON APR 2 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT TONIGHT THROUGH
EARLY TUESDAY BEFORE IT MOVES OFFSHORE. UNSETTLED CONDITIONS WILL
PERSIST THROUGH MID WEEK AS THIS FRONT RETURNS NORTH AS A WARM FRONT
ON TUESDAY. ANOTHER COLD FRONT WILL TRACK SOUTH THROUGH THE AREA
WEDNESDAY NIGHT INTO THURSDAY FOLLOWED BY A REINFORCING SHOT OF COLD
AIR FRIDAY NIGHT INTO SATURDAY AS STRONG HIGH PRESSURE BUILDS DOWN
ACROSS THE SOUTHEAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM MONDAY...COLD FRONT CLEARLY EVIDENT ON VISIBLE IMAGERY
THIS AFTN IS CURRENTLY STRETCHED EAST TO WEST FROM WILMINGTON...TO
ELIZABETHTOWN...TO ALBEMARLE. THIS HAS NOT BEEN PROGRESSING AS
QUICKLY AS GUIDANCE INDICATED...AND THUS TEMPS HAVE SOARED INTO THE
LOW 80S MOST LOCATIONS. THE EXCEPTION HAS BEEN ACROSS THE BORDER
COUNTIES WHERE A BAND OF PREFRONTAL CLOUDINESS...REMNANTS OF LAST
NIGHTS CONVECTION...HAS SIGNIFICANTLY LIMITED HEATING. STILL EXPECT
MOST LOCATIONS WILL ECLIPSE 80 THIS AFTN AHEAD OF THE COLD FRONT.
CONCERN THOUGH TONIGHT IS CONVECTIVE POTENTIAL ALONG THE BOUNDARY.
HAVE SEEN VERY LITTLE IN THE WAY OF CU ON THE SATELLITE THIS
AFTN...WHICH IS A BIT SURPRISING. HOWEVER...SPC STILL HAS ALL OF SC
OUTLINED FOR POTENTIAL TSTMS ALONG AND AHEAD OF THIS COLD FRONT.
LATEST RUC SOUNDINGS DEPICT SLIGHTLY WEAKER CONVECTIVE INDICES THAN
EXPECTED THIS MORNING...INCLUDING A SUBTLE DECREASE IN MID LEVEL
LAPSE RATES...WHICH MAY BE CONTRIBUTING TO THE LACK OF DIURNAL CU.
ADDITIONALLY...VERY DRY AIR ABOVE 500MB IS LIMITING DEEP UPDRAFTS.
STILL...WILL KEEP SCHC...ALBEIT WITH LOWER ABSOLUTE POP
VALUES...ACROSS SC UNTIL COLD FROPA OCCURS. FEEL THIS IS WARRANTED
SINCE SOME AGITATED CU HAS SHOWN UP IMMEDIATELY ALONG THE
FRONT...AND LOW LEVEL LAPSE RATES WILL BECOME SUPER-ADIABATIC
THROUGH THIS AFTN ACROSS SC ZONES. DO NOT ANTICIPATE TSTMS IN THE NC
COUNTIES WHERE FRONTAL INVERSION WILL SQUELCH ANY SURFACE BASED
INSTABILITY...BUT A SHOWER OR TWO IS POSSIBLE. SEVERE THREAT IS
QUITE LIMITED...BUT AN ISOLATED DAMAGING WIND GUST IS STILL
POSSIBLE...ESPECIALLY ACROSS EXTREME SOUTHERN ZONES.
FROPA WILL MOVE SOUTH OF THE CWA BY SUNSET...FOLLOWED BY GUSTY N/NE
WINDS FOR A FEW HOURS BEFORE GRADIENT SLACKENS AND WINDS EASE. HIGH
PRESSURE BUILDS SOUTHWARD AND SKY CONDITIONS WILL CLEAR...SO
RADIATIONAL COOLING WILL BE DEPENDENT ON HOW QUICKLY WINDS CAN EASE
AFTER SUNSET...TO ALLOW FOR A STEEPER NOCTURNAL INVERSION. HAVE
DROPPED MINS ABOUT A DEGREE ACROSS THE NORTHERN ZONES...LEFT STATUS
QUO ACROSS SC...WITH UPPER 40S IN NC...TO MID 50S NEAR THE BERKLEY
COUNTY LINE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...BACKDOOR COLD FRONT OFF TO THE SOUTH WILL ALLOW
RIDGE OF HIGH PRESSURE TO NOSE INTO THE CAROLINAS FROM THE NORTH
EARLY TUESDAY. THIS AIRMASS WILL QUICKLY SLIDE OFF THE COAST BY
AFTERNOON. SOME MOISTURE RETURN WILL BE ENSUE FROM WEST TO EAST
ACROSS THE CAROLINAS. IN THE UPPER LEVELS A SHORT AMPLITUDE RIDGE
WILL HOLD ON FOR THE MOST PART. MODELS STRUGGLING WITH SOME
CONVECTIVELY INDUCED VORT CENTERS EMANATING FROM TEXAS...AND
DEEPENING ON THE TRACK AND STRENGTH OF THESE FEATURES THEY MAY BE
ABLE TO SERVE AS SOME WEAK FORCING LOCALLY. BARRING THIS POSSIBILITY
MOST OF THE AREA LOOKS TO REMAIN RAIN-FREE WITH NEAR SEASONABLE
TEMPERATURES. ADVECTION OF WARMTH AND MOISTURE WILL CONTINUE FOR
THE REMAINDER OF THE PERIOD KEEPING TUESDAY NIGHT VERY MILD
ESPECIALLY DUE TO THE INCREASED CLOUD COVER. THE UPPER RIDGE WILL
CONTINUE TO BE WEAKENED ON WEDNESDAY ALLOWING CLEARER PASSAGE OF
SOME WEAK VORTICITY CENTERS. A PREFRONTAL PIEDMONT TROUGH WILL TEND
TO FOCUS MOST OF THE SCATTERED CONVECTION OVER WESTERN ZONES
INITIALLY. HOWEVER SINCE STORMS WILL HAVE A WELL DEFINED EASTWARD
MOTION THERE WILL BE ONLY A SLIGHT GRADIENT IN FCST POPS AT THIS
TIME. QPF WILL BE HIGHER OVER WRN ZONES (ALTHOUGH STILL QUITE LOW).
DESPITE THE CLOUD COVER MOST PLACES SHOULD HAVE NO TROUBLE SEEING A
HIGH IN THE LOW 80S. COLD FRONT ARRIVES LATE WEDNESDAY NIGHT AND
LOOKS QUITE MOISTURE-CHALLENGED.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...PROGRESSIVE PATTERN WILL PREVAIL THROUGH THE
EXTENDED AS A MID LEVEL CYCLONE MOVES ACROSS EARLY FOLLOWED BY BRIEF
RIDGING. FINALLY...AT THE END OF THE PERIOD SUBTLE TROUGHING WILL
MOVE ACROSS. THE FORECAST CHALLENGES CONTINUE TO CENTER AROUND
TIMING AND MAGNITUDE FOR FRIDAY TRANSITIONING TO A TEMPERATURE
FORECAST FOR THE WEEKEND.
STILL SOME UNCERTAINTY WITH REGARDS TO THE CHARACTERISTIC OF THE
SYSTEM FRIDAY AS THE LATEST GFS...AND PAST COUPLE OF CYCLES FOR THAT
MATTER SHOW A CLOSED MID LEVEL CYCLONE MOVING ACROSS THE UPSTATE OF
SOUTH CAROLINA THEN OPENING UP AND MOVING OFF QUICKLY. THE ECMWF AND
ENSEMBLES ARE SIMILAR BUT A BIT FURTHER SOUTH. I HAVE INCREASED POPS
TO LIKELY FOR FRIDAY MATCHING HPC AND INCREASED POPS INTO SATURDAY
MORNING TO ADDRESS SLOWER TIMING WITH A SYSTEM THAT REMAINS CLOSED
FOR A LONGER PERIOD OF TIME.
TEMPERATURES DROP TO JUST BELOW CLIMATOLOGY SATURDAY AND SUNDAY
BEFORE REBOUNDING QUICKLY WITH A SOUTHWEST FLOW MONDAY. SUNDAY
SHOULD BE THE COOLEST MORNING COUPLED WITH THE BEST RADIATIONAL
CONDITIONS WITH MID TO UPPER 40S CWA WIDE. SOME CLIMATOLOGICALLY
FAVORED AREAS COULD SEE A DEGREE OR TWO BELOW 45.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...THE COLD FRONT CAN CLEARLY BE SEEN IN VISIBLE SATELLITE
IMAGERY AND CONTINUITY WAS USED FOR TIMING OF PASSAGE AT THE
TERMINALS. SOME PATCHY LIGHT RAIN FROM MAINLY MID-LEVEL CLOUDS IS
OCCURRING BUT RADAR LOOPS INDICATES A DECREASING TREND. ANY
MID-LEVEL CEILINGS WILL DECREASE THIS AFTERNOON WITH SCATTERED SKIES
EXPECTED BY LATE AFTERNOON AT ALL TERMINALS. THERE IS HIGH
CONFIDENCE OF VFR AT ALL TERMINALS THROUGH THIS TAF VALID PERIOD. NO
THUNDERSTORMS ARE EXPECTED TO AFFECT THE TERMINALS THIS
AFTERNOON...ALTHOUGH THERE COULD BE SOME ACTIVITY DEVELOP ALONG THE
FRONT SOUTH OF THE FLO/MYR TERMINALS BY LATE AFTERNOON. IF THIS
OCCURS THE STORMS SHOULD MOVE WELL SOUTH OF FLO/LBT BY EVENING.
THIS EVENING WIND SPEEDS DECREASE AND BECOME NORTHEAST TO EAST AS
HIGH PRESSURE SETTLES IN. VFR LEVEL LOW CEILINGS WILL RE-DEVELOP AT
THE SOUTHERNMOST TERMINALS OVERNIGHT AND SPREAD TO THE ILM/LBT
TERMINALS AFTER SUNRISE. MODELS ARE HINTING THAT LIGHT RAIN COULD
RE-DEVELOP AFTER MIDNIGHT...MAINLY WEST AND SOUTH OF FLO.
EXTENDED OUTLOOK...VFR TUESDAY. LOW CONFIDENCE ISOLATED SHOWERS AND
THUNDERSTORMS WITH TEMPO MVFR WEDNESDAY THROUGH THURSDAY NIGHT. A
GOOD CHANCE OF SHOWERS/EMBEDDED THUNDERSTORMS WITH WIDESPREAD IFR
FRIDAY. VFR SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM MONDAY...COLD FRONT CROSSING AMZ250 PRESENTLY...AND
THIS WILL CONTINUE ITS TREK SOUTH THROUGH TONIGHT. WINDS AND SEAS
HAVE EASED A BIT AT THE LOCAL BUOYS...BUT NOTICED STRONG GUSTY WINDS
ACROSS WATERS TO OUR NORTH...AND THUS HAVE EXTENDED THE SCEC THROUGH
6PM FOR THE NORTHERN 2 COASTAL WATER ZONES. EXPECT WINDS TO TURN TO
THE N/NE...FIRST ACROSS AMZ250...LASTLY IN AMZ256...AND GUST TO
AROUND 25 KTS. THIS WILL HELP REBUILD SEAS TO 3-5 FT...ALTHOUGH THE
5 FTERS WILL BE ISOLATED NEAR THE OUTER 20NM BOUNDARY. WINDS EASE
FOR A FEW HOURS AFTER SUNSET AS GRADIENT RELAXES SLIGHTLY IN ADVANCE
OF HIGH PRESSURE...BUT A NE SURGE LATE WILL ONCE AGAIN RAISE WINDS
TO 15-20 KTS KEEPING SEAS AT 2-4 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...NORTHEAST WINDS ON TUESDAY WITH A BACKDOOR FRONT
OFF TO THE SOUTH AND HIGH PRESSURE BUILDING IN FROM THE NORTH EARLY
TUESDAY. THIS HIGH WILL MOVE OFF THE COAST BY AFTERNOON BRINGING
VEERING AND PERHAPS DECREASING WINDS. VEERING CONTINUES TUESDAY
NIGHT BRINGING A MORE DEFINED SOUTHERLY COMPONENT. NO REAL SWELL
ENERGY ON THE RADAR SO SEAS GENERALLY 2 TO 3 FT THROUGHOUT.
WEDNESDAY BRINGS A PREFRONTAL SOUTHWESTERLY FLOW REGIME WITH A
TIGHTENING GRADIENT. THIS SHOULD ADD ABOUT A FOOT TO THE PREDOMINANT
WAVE HEIGHT.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...NORTHEAST FLOW INITIALLY WILL VEER A BIT TO MORE
TO AN EASTERLY DIRECTION EARLY FRIDAY AS LOW PRESSURE DROPS WELL TO
THE SOUTH. STILL SOME UNCERTAINTY OF THE EXACT TIMING AND PLACEMENT
OF THE SYSTEM SO WE COULD SEE WINDS VEER EVEN MORE THROUGH FRIDAY
THAN THE CURRENT FORECAST ADVERTISES. NORTHEASTERLY FLOW LATE FRIDAY
THROUGH SATURDAY AS HIGH PRESSURE BUILDS IN BEHIND THE SYSTEM. AS
USUAL SURGES ARE DIFFICULT TO TIME BUT SHOULD SEE SEVERAL HOURS OF
SPEEDS NEAR 20 KNOTS ACROSS THE OUTER WATERS. WAVEWATCH SEAS
INCREASE FROM 2-4 FEET EARLY TO 4-7 FEET LATE IN THE PERIOD WITH THE
STRONGER FETCH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...MBB
LONG TERM...SHK
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
304 PM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA THIS
AFTERNOON... BEFORE STALLING OVER THE MOUNTAINS... AND NEAR THE
SOUTH CAROLINA BORDER TONIGHT. THE FRONT WILL THEN TURN BACK
NORTHWARD AS A WARM FRONT TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1039 AM MONDAY...
UPDATE: CLEARING ALONG THE I-40 CORRIDOR HAS ALLOWED TEMPS TO REACH
THE LOW TO MID 70S IN THAT AREA. CLOUD COVER ACROSS THE SOUTHWEST
AND ALONG THE NC/VA BORDER HAVE KEPT TEMPS IN THE MID 60S. AS OF 14Z
THE BACKDOOR COLD FRONT WAS STRETCHED FROM DANVILLE VA SOUTH AND
EAST ACROSS THE AREA...HANGING OUT JUST EAST OF RDU... SMITHFIELD...
AND GOLDSBORO. DEWPOINTS BEHIND THE FRONT ARE CRASHING INTO THE 40S
AND LOW 50S...WITH TEMPS IN THE LOW TO MID 60S. SOME LIGHT SHOWERS
HAVE STARTED IMPINGE ON THE SOUTHWESTERN EXTENT OF THE AREA. THIS
CLOUD COVER AND SHOWERS MAY ACT TO KEEP TEMPS FROM RISING AS HIGH AS
PREVIOUSLY THOUGHT...THUS HAVE LOWERED HIGH ACROSS THE SOUTHWEST TO
AROUND 81 DEGREES. WITH THE CLEARING ACROSS THE I-40 CORRIDOR AND
TEMPS ALREADY IN THE LOW 70S HAVE INCREASED HIGHS SLIGHTLY TO THE
MID 70S.
PREVIOUS DISCUSSION:
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 235 PM MONDAY...
A WARM ADVECTION PATTERN WILL BE UNDERWAY ACROSS CENTRAL NORTH
CAROLINA TUESDAY EVENING AS THE WARM FRONT WILL BE NORTH OF THE
REGION. THE LATEST MODELS GENERALLY AGREE IN THAT THE CHANCE OF
SHOWERS/ISOLATED THUNDERSTORMS WILL BE OF A DIURNAL NATURE IN THE
WARM SECTOR LATE TUESDAY/TUESDAY EVENING... SHOULD BE CONFINED TO
THE MOUNTAINS INTO THE EVENING HOURS BEFORE WEAKENING. THE CURRENT
THINKING IS THAT THERE MAY BE AN ISOLATED SHOWER OR THUNDERSTORM
MAINLY OVER THE WESTERN PIEDMONT BUT CENTRAL NORTH CAROLINA SHOULD
REMAIN LARGELY DRY TUESDAY NIGHT. SINCE WE WILL IN THE WARM
SECTOR... A SW BREEZE AROUND 10 MPH WILL KEEP TEMPERATURES UP
TUESDAY NIGHT WITH LOWS EXPECTED TO BE MOSTLY IN THE UPPER 50S TO
LOWER 60S.
WEDNESDAY AND WEDNESDAY NIGHT...
INCREASING INSTABILITY ALONG WITH STRONG SURFACE HEATING AND AN
APPROACHING UPPER LEVEL DISTURBANCE IN THE NW FLOW ALOFT WILL
INCREASE THE CHANCE OF THUNDERSTORMS WEDNESDAY AFTERNOON. THE BEST
CHANCE OF THUNDERSTORMS SHOULD BE ALONG OR NEAR 1)A PIEDMONT TROUGH
THAT IS FORECAST TO ALIGN FROM SW TO NE ACROSS OUR REGION... AND 2)
THE ASSOCIATED SURFACE BOUNDARY THAT IS FORECAST TO DIP SOUTH INTO
THE REGION DURING THE LATE AFTERNOON INTO THE EVENING. PARTLY SUNNY
SKIES SHOULD LEAD TO EXCELLENT HEATING AS HIGHS REACH THE 80-85
RANGE... WITH SOME UPPER 80S POSSIBLE IN THE SANDHILLS.
INCREASING WINDS IN THE MID AND UPPER LEVELS SHOULD HELP WITH STORM
ORGANIZATION. MLCAPES OF NEAR 1500+ J/KG ARE EXPECTED TO LEAD TO AT
LEAST SCATTERED THUNDERSTORMS BY EARLY AFTERNOON ALONG THE PIEDMONT
TROUGH... WITH ADDITIONAL CONVECTION EXPECTED TO FIRE ALONG THE
SOUTHWARD MOVING COLD FRONT LATER IN THE AFTERNOON NEAR THE NC/VA
BORDER. THE LATTER MAY EVENTUALLY EVOLVE INTO A LINE OF SHOWERS AND
THUNDERSTORMS. A FEW OF THE STORMS MAY BECOME SEVERE WITH THE MAIN
THREATS BEING STRONG WIND GUSTS TO NEAR SEVERE LIMITS AND POSSIBLY
MARGINALLY SEVERE HAIL (UP TO THE SIZE OF QUARTERS). THE THREAT OF
STRONG STORMS SHOULD PERSIST WELL INTO THE EVENING AND POSSIBLY
OVERNIGHT (IN THE SOUTHERN ZONES). OTHERWISE... HIGHS ARE EXPECTED
TO REACH 80-85 WITH POTENTIALLY SOME UPPER 80S OVER THE SANDHILLS.
WEAK HIGH PRESSURE IS EXPECTED TO PUSH SOUTHWARD FROM THE
MID-ATLANTIC STATES INTO NE SECTIONS OF THE AREA WEDNESDAY NIGHT...
OTHERWISE A WEAK BOUNDARY WILL STALL OVER WESTERN AND SOUTHERN
ZONES. UNDER VARIABLY CLOUDY SKIES... THERE WILL STILL BE A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY IN THE SOUTH AND
SOUTHWEST PIEDMONT OVERNIGHT. LOWS WILL BE COOLEST NE AND WARMEST SW
(LOWER 50S TO LOWER 60S).
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 304 PM MONDAY...
THE LATEST MODELS CONTINUE TO ADVERTISE THAT AN APPROACHING
MID-UPPER LEVEL LOW FROM THE SOUTHERN PLAINS STATES WILL GRADUALLY
WEAKEN AND DIP MORE SOUTHERLY ACROSS THE TENNESSEE VALLEY AND OVER
GA/SC THURSDAY THROUGH FRIDAY. THE COMBINATION OF A WEAK SURFACE
HIGH NEAR THE NC/VA COAST COMBINED WITH A WARM FRONT WELL TO OUR
SOUTH SHOULD LEAD TO A MOSTLY CLOUDY DAY THURSDAY. A MOIST EASTERLY
LOW LEVEL FLOW WILL BRING INCREASING ATLANTIC MOISTURE ACROSS OUR
REGION. THIS COMBINED WITH THE APPROACHING UPPER LEVEL LOW WILL
CREATE AT LEAST A CHANCE OF SHOWERS (MAINLY WEST) THURSDAY. AS THE
MID-UPPER LOW DAMPENS AND SLIDES MORE SE... THE BEST CHANCE OF RAIN
WILL LIKELY BE OVER WESTERN AND SOUTHERN NC... WITH THE LEAST CHANCE
ACROSS THE NE ZONES. HOWEVER... UNCERTAINTY STILL ABOUNDS WITH THE
STRENGTH AND TRACK OF THIS UPPER SYSTEM. IF THE CURRENT MODELS ARE
CORRECT... THEN MUCH OF THE HEAVY RAIN SHOULD BE CONFINED JUST TO
OUR SW AS OUR SYSTEM DIVES SE. IF THE SYSTEM REMAINS STRONGER THAN
CURRENTLY FORECAST... THEN IT IS ENTIRELY POSSIBLE THAT IT WOULD
CONTINUE MOVING EAST AND BRING THE HEAVIER RAIN NORTHEASTWARD OVER
CENTRAL NC. AT THE VERY LEAST... THIS LOOKS TO BE A COOL/CLOUDY
PERIOD (THU-FRI)... WITH QPF OF 0.25 TO 0.50 SW... LESSER AMOUNTS
AROUND 0.10 NE. LOWS 50-60 NE TO SW. HIGHS NEAR 60 NORTH TO LOWER
70S SOUTH EXPECTED THURSDAY... POSSIBLY COOLER FRIDAY DEPENDING ON
THE TRACK OF THE SYSTEM AND AMOUNT OF RAIN.
SATURDAY THROUGH MONDAY... MUCH COOLER AND DRIER AIR IS FORECAST
BASED ON THE GENERAL MODEL CONSENSUS OF 1025+ MB SURFACE HIGH
PRESSURE BUILDING SOUTH INTO NC/SC FROM NEW ENGLAND. ANOTHER COLD
FRONT WILL BRING ADDITIONAL COOLING MONDAY NIGHT AND TUESDAY.
LOWS SAT-SUN SHOULD AVERAGE IN THE UPPER 30S TO MID 40S WITH SOME
MID 30S POSSIBLE IN THE NE. HIGHS GENERALLY IN THE MID 60S TO LOWER
70S SAT-SUN... AND 70S MONDAY.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
AS OF 145 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. AHEAD OF THE
BACKDOOR COLD FRONT WINDS WILL BE NNW AT 5-10 KT...WITH WINDS BEHIND
THE FRONT NNE AT 10-15 KT GUSTING UP TO 20 KT. EXPECT GUSTS TO DIE
DOWN AROUND SUNSET...WITH MAINLY EASTERLY WINDS AT 5 KTS OR LESS
ACROSS ALL TERMINALS THROUGH SUNRISE. SKIES WILL BE MAINLY CLEAR
OVERNIGHT WITH THE EXCEPTION OF SOME SCATTERED CLOUDS AT KINT AND
KGSO. SHOULD SEE SOME BROKEN CIGS AROUND 3500 FT MOVING INTO THE
AREA FROM WEST TO EAST...STARTING AROUND 08Z AT KINT AND KGSO AND
MAKING IT TOWARD KRWI AT THE END OF THE TAF PERIOD.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
MVFR CEILINGS MAY MAKE THEIR WAY INTO THE AREA FROM SW-NE OR W-E AS
THE STALLED FRONT LIFTS BACK THROUGH CENTRAL NC AS A WARM FRONT
DURING THE DAY TUE. A PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE
EARLY WED MORNING (06-12Z) IN ASSOC/W WARM ADVECTION UNDER THE
NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND STORMS ARE EXPECTED
DURING THE DAY WED IN ADVANCE OF ANOTHER BACKDOOR COLD FRONT
APPROACHING THE AREA FROM THE NORTH. A PROLONGED PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN ASSOC/W LOW-LEVEL
NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...KC/VINCENT
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...KC/VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
207 PM EDT MON APR 2 2012
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH ACROSS THE AREA TODAY AND MAY RESULT IN
SOME STRONG STORMS ACROSS PORTIONS OF THE AREA THIS AFTERNOON. WEAK
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT TONIGHT THROUGH EARLY
TUESDAY BEFORE IT MOVES OFFSHORE. UNSETTLED CONDITIONS WILL PERSIST
THROUGH MID WEEK AS THIS FRONT RETURNS NORTH AS A WARM FRONT ON
TUESDAY. ANOTHER COLD FRONT WILL TRACK SOUTH THROUGH THE AREA
WEDNESDAY NIGHT INTO THURSDAY FOLLOWED BY A REINFORCING SHOT OF COLD
AIR FRIDAY NIGHT INTO SATURDAY AS STRONG HIGH PRESSURE BUILDS DOWN
ACROSS THE SOUTHEAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM MONDAY...COLD FRONT CLEARLY EVIDENT ON VISIBLE IMAGERY
THIS AFTN IS CURRENTLY STRETCHED EAST TO WEST FROM WILMINGTON...TO
ELIZABETHTOWN...TO ALBERMARLE. THIS HAS NOT BEEN PROGRESSING AS
QUICKLY AS GUIDANCE INDICATED...AND THUS TEMPS HAVE SOARED INTO THE
LOW 80S MOST LOCATIONS. THE EXCEPTION HAS BEEN ACROSS THE BORDER
COUNTIES WHERE A BAND OF PREFRONTAL CLOUDINESS...REMNANTS OF LAST
NIGHTS CONVECTION...HAS SIGNIFICANTLY LIMITED HEATING. STILL EXPECT
MOST LOCATIONS WILL ECLIPSE 80 THIS AFTN AHEAD OF THE COLD FRONT.
CONCERN THOUGH TONIGHT IS CONVECTIVE POTENTIAL ALONG THE BOUNDARY.
HAVE SEEN VERY LITTLE IN THE WAY OF CU ON THE SATELLITE THIS
AFTN...WHICH IS A BIT SURPRISING. HOWEVER...SPC STILL HAS ALL OF SC
OUTLINED FOR POTENTIAL TSTMS ALONG AND AHEAD OF THIS COLD FRONT.
LATEST RUC SOUNDINGS DEPICT SLIGHTLY WEAKER CONVECTIVE INDICES THAN
EXPECTED THIS MORNING...INCLUDING A SUBTLE DECREASE IN MID LEVEL
LAPSE RATES...WHICH MAY BE CONTRIBUTING TO THE LACK OF DIURNAL CU.
ADDITIONALLY...VERY DRY AIR ABOVE 500MB IS LIMITING DEEP UPDRAFTS.
STILL...WILL KEEP SCHC...ALBEIT WITH LOWER ABSOLUTE POP
VALUES...ACROSS SC UNTIL COLD FROPA OCCURS. FEEL THIS IS WARRANTED
SINCE SOME AGITATED CU HAS SHOWN UP IMMEDIATELY ALONG THE
FRONT...AND LOW LEVEL LAPSE RATES WILL BECOME SUPER-ADIABATIC
THROUGH THIS AFTN ACROSS SC ZONES. DO NOT ANTICIPATE TSTMS IN THE NC
COUNTIES WHERE FRONTAL INVERSION WILL SQUELCH ANY SURFACE BASED
INSTABILITY...BUT A SHOWER OR TWO IS POSSIBLE. SEVERE THREAT IS
QUITE LIMITED...BUT AN ISOLATED DAMAGING WIND GUST IS STILL
POSSIBLE...ESPECIALLY ACROSS EXTREME SOUTHERN ZONES.
FROPA WILL MOVE SOUTH OF THE CWA BY SUNSET...FOLLOWED BY GUSTY N/NE
WINDS FOR A FEW HOURS BEFORE GRADIENT SLACKENS AND WINDS EASE. HIGH
PRESSURE BUILDS SOUTHWARD AND SKY CONDITIONS WILL CLEAR...SO
RADIATIONAL COOLING WILL BE DEPENDENT ON HOW QUICKLY WINDS CAN EASE
AFTER SUNSET...TO ALLOW FOR A STEEPER NOCTURNAL INVERSION. HAVE
DROPPED MINS ABOUT A DEGREE ACROSS THE NORTHERN ZONES...LEFT STATUS
QUO ACROSS SC...WITH UPPER 40S IN NC...TO MID 50S NEAR THE BERKELY
COUNTY LINE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...WITH SURFACE FRONT JUST SOUTH A COOLER
NORTHEASTERLY FLOW WILL KEEP TEMPS AROUND CLIMO. WEAK HIGH PRESSURE
SHIFTING OFF SHORE WILL ALLOW A RETURN FLOW TO SET UP AT THE SFC BY
LATER ON TUES...WITH DRIER AIR STILL PRESENT ALOFT. THIS WILL ALLOW
OLD BOUNDARY TO THE SOUTH TO GET PUSHED BACK NORTH AS A WARM FRONT
WITH WEAK LIFT GIVING POSSIBILITY OF PCP MAINLY OVER SC ZONES BY
LATE TUES. BY TUES NIGHT A SHORTWAVE WILL TRACK AROUND THE MID TO
UPPER RIDGE ACROSS LOCAL AREA. THIS HELPS TO FLATTEN OUT THE RIDGE
OVER THE SOUTHEAST. EXPECT INCREASING CLOUDS AND CHC OF PCP AS THIS
IMPULSE RIDES THROUGH TUES NIGHT. THIS WILL HELP TO KEEP TEMPS UP
TUES NIGHT. PCP WATER INCREASES UP TO 1.5 INCHES OVERNIGHT TUES INTO
WED. ANOTHER SURFACE COLD FRONT WILL TRACK SOUTH ON WED AND WILL
REACH AREA BY WED EVENING AS MOISTURE IN THE MID TO UPPER LEVELS
INCREASES FROM THE WEST AHEAD OF ANOTHER SYSTEM TRACKING EAST ACROSS
THE TENNESSEE VALLEY. WILL REMAIN IN WARM SECTOR IN A WARMER AND
MORE UNSTABLE ATMOSPHERE AHEAD OF COLD FRONT TRACKING APPROACHING
THE CAROLINAS BY AFTN. OVERALL EXPECT A FAIR AMOUNT OF CLOUDS A CHC
OF SHWRS/TSTMS ON WED. TEMPS SHOULD WARM TO AROUND 80 TO 85 WED IN A
WARMER AND MOISTER SOUTHWEST TO WESTERLY FLOW AHEAD OF NEXT COLD
FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...BACK DOOR COLD FRONT WILL TRACK THROUGH AREA ON
THURS. THIS SHALLOW COOLER AIR WILL ADVECT IN WITH NE TO E FLOW AND
WEST SOUTHWEST FLOW ABOVE IT. GFS SHOWING BEST LIFT EARLY THURS AND
PCP WATER VALUES UP AROUND 1.5 INCHES. EXPECT UNSETTLED WEATHER WITH
CLOUDS AND CHC OF PCP THROUGH THURS INTO FRI BEFORE MID TO UPPER
TROUGH PUSHES A COLD FRONT THROUGH BY SAT. THIS WILL SCOUR OUT ANY
MOISTURE LEFT AND COOLER AND DRIER HIGH PRESSURE WILL BUILD IN FOR
THE WEEKEND IN A DEEPER NORTHERLY FLOW SAT THROUGH SUNDAY. LATEST
GFS NOT AS AGGRESSIVE WITH COLD AIR BUT DOES BRING 850 TEMPS DOWN
FROM 14 C MID WEEK TO 5 C ON SATURDAY. H5 HEIGHTS BOTTOM OUT AS MID
TO UPPER TROUGH AXIS MOVES THROUGH AREA LATE FRI AND THEN RIDGE
BUILDS UP THE EAST COAST WITH HEIGHTS REACHING UP AROUND 580 DEM BY
SUNDAY. PCP WATER VALUES FALL TO LESS THAN A HALF INCH BY SAT AFTN
AND DECREASE FURTHER THROUGH THE REMAINDER OF THE WEEKEND IN DEEP
NORTHEASTERLY FLOW. TEMPS WILL REMAIN AT OR BELOW CLIMO THROUGH THE
LONG TERM PERIOD. INITIALLY ON THURS AND FRI...A SHALLOW COOL POOL
WITH CLOUDS AND PCP WILL HOLD TEMPS DOWN CLOSER TO 70 AND THEN COOL
AND DRY AIR WILL ADVECT IN BEHIND FRONT FOR THE WEEKEND. THIS WILL
KEEP TEMPS AROUND 70 THROUGH THE WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...THE COLD FRONT CAN CLEARLY BE SEEN IN VISIBLE SATELLITE
IMAGERY AND CONTINUITY WAS USED FOR TIMING OF PASSAGE AT THE
TERMINALS. SOME PATCHY LIGHT RAIN FROM MAINLY MID-LEVEL CLOUDS IS
OCCURRING BUT RADAR LOOPS INDICATES A DECREASING TREND. ANY
MID-LEVEL CEILINGS WILL DECREASE THIS AFTERNOON WITH SCATTERED SKIES
EXPECTED BY LATE AFTERNOON AT ALL TERMINALS. THERE IS HIGH
CONFIDENCE OF VFR AT ALL TERMINALS THROUGH THIS TAF VALID PERIOD. NO
THUNDERSTORMS ARE EXPECTED TO AFFECT THE TERMINALS THIS
AFTERNOON...ALTHOUGH THERE COULD BE SOME ACTIVITY DEVELOP ALONG THE
FRONT SOUTH OF THE FLO/MYR TERMINALS BY LATE AFTERNOON. IF THIS
OCCURS THE STORMS SHOULD MOVE WELL SOUTH OF FLO/LBT BY EVENING.
THIS EVENING WIND SPEEDS DECREASE AND BECOME NORTHEAST TO EAST AS
HIGH PRESSURE SETTLES IN. VFR LEVEL LOW CEILINGS WILL RE-DEVELOP AT
THE SOUTHERNMOST TERMINALS OVERNIGHT AND SPREAD TO THE ILM/LBT
TERMINALS AFTER SUNRISE. MODELS ARE HINTING THAT LIGHT RAIN COULD
RE-DEVELOP AFTER MIDNIGHT...MAINLY WEST AND SOUTH OF FLO.
EXTENDED OUTLOOK...VFR TUESDAY. LOW CONFIDENCE ISOLATED SHOWERS AND
THUNDERSTORMS WITH TEMPO MVFR WEDNESDAY THROUGH THURSDAY NIGHT. A
GOOD CHANCE OF SHOWERS/EMBEDDED THUNDERSTORMS WITH WIDESPREAD IFR
FRIDAY. VFR SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM MONDAY...COLD FRONT CROSSING AMZ250 PRESENTLY...AND
THIS WILL CONTINUE ITS TREK SOUTH THROUGH TONIGHT. WINDS AND SEAS
HAVE EASED A BIT AT THE LOCAL BUOYS...BUT NOTICED STRONG GUSTY WINDS
ACROSS WATERS TO OUR NORTH...AND THUS HAVE EXTENDED THE SCEC THROUGH
6PM FOR THE NORTHERN 2 COASTAL WATER ZONES. EXPECT WINDS TO TURN TO
THE N/NE...FIRST ACROSS AMZ250...LASTLY IN AMZ256...AND GUST TO
AROUND 25 KTS. THIS WILL HELP REBUILD SEAS TO 3-5 FT...ALTHOUGH THE
5 FTERS WILL BE ISOLATED NEAR THE OUTER 20NM BOUNDAY. WINDS EASE FOR
A FEW HOURS AFTER SUNSET AS GRADIENT RELAXES SLIGHTLY IN ADVANCE OF
HIGH PRESSURE...BUT A NE SURGE LATE WILL ONCE AGAIN RAISE WINDS TO
15-20 KTS KEEPING SEAS AT 2-4 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...LINGERING SURFACE COLD FRONT SHOULD BE JUST
SOUTH OF LOCAL WATERS TUES MORNING WITH A LIGHT NE TO E FLOW.
WEAK HIGH PRESSURE BEHIND FRONT WILL SHIFT OFF SHORE AS WINDS
CONTINUE TO VEER AROUND TO THE E-SE BEFORE RETURN FLOW SETS UP
THROUGH LATE TUES WITH WINDS INCREASING OUT OF THE S-SW THROUGH
EARLY WED. WINDS WILL CONTINUE TO VEER ON WED TO THE SW TO W AHEAD
OF COLD FRONT APPROACHING THE CAROLINAS FROM THE NW. SEAS WILL
MAINLY BE 2 TO 3 FT DECREASING SLIGHTLY INITIALLY ON TUES IN
WEAKENING FLOW AND THEN INCREASING IN INCREASING W-SW FLOW ON WED.
THE OFF SHORE COMPONENT TO THE FLOW WILL MAINLY AFFECT THE OUTER
WATERS WITH AN INCREASE IN SEAS UP TO 3 TO 4 FT WED INTO WED
NIGHT.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...COLD FRONT WILL MAKE ITS WAY SOUTH ON THURS WITH
WINDS VEERING AROUND FROM THE W-NW TO N-NE THROUGH THE DAY. WINDS
WILL CONTINUE OUT OF THE NE THROUGH FRI AND WILL THEN INCREASE UP
TO 15 TO 25 KTS BY LATE FRI INTO SAT AS SURGE TAKES PLACE BEHIND
FRONT. THESE INCREASING NE WINDS FRI NIGHT WILL TIP SEAS INTO SCA
THRESHOLDS BY FRI EVENING AND COULD REACH AS HIGH AS 7 TO 8 FT IN
OUTER WATERS IN FLOW REMAINING MAINLY PARALLEL TO THE COAST
BY SAT MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
149 PM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1039 AM MONDAY...
UPDATE: CLEARING ALONG THE I-40 CORRIDOR HAS ALLOWED TEMPS TO REACH
THE LOW TO MID 70S IN THAT AREA. CLOUD COVER ACROSS THE SOUTHWEST
AND ALONG THE NC/VA BORDER HAVE KEPT TEMPS IN THE MID 60S. AS OF 14Z
THE BACKDOOR COLD FRONT WAS STRETCHED FROM DANVILLE VA SOUTH AND
EAST ACROSS THE AREA...HANGING OUT JUST EAST OF RDU... SMITHFIELD...
AND GOLDSBORO. DEWPOINTS BEHIND THE FRONT ARE CRASHING INTO THE 40S
AND LOW 50S...WITH TEMPS IN THE LOW TO MID 60S. SOME LIGHT SHOWERS
HAVE STARTED IMPINGE ON THE SOUTHWESTERN EXTENT OF THE AREA. THIS
CLOUD COVER AND SHOWERS MAY ACT TO KEEP TEMPS FROM RISING AS HIGH AS
PREVIOUSLY THOUGHT...THUS HAVE LOWERED HIGH ACROSS THE SOUTHWEST TO
AROUND 81 DEGREES. WITH THE CLEARING ACROSS THE I-40 CORRIDOR AND
TEMPS ALREADY IN THE LOW 70S HAVE INCREASED HIGHS SLIGHTLY TO THE
MID 70S.
PREVIOUS DISCUSSION:
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. GIVEN WARM ADVECTION OVERNIGHT...EXPECT LOWS IN THE MID
TO UPPER 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
AS OF 145 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. AHEAD OF THE
BACKDOOR COLD FRONT WINDS WILL BE NNW AT 5-10 KT...WITH WINDS BEHIND
THE FRONT NNE AT 10-15 KT GUSTING UP TO 20 KT. EXPECT GUSTS TO DIE
DOWN AROUND SUNSET...WITH MAINLY EASTERLY WINDS AT 5 KTS OR LESS
ACROSS ALL TERMINALS THROUGH SUNRISE. SKIES WILL BE MAINLY CLEAR
OVERNIGHT WITH THE EXCEPTION OF SOME SCATTERED CLOUDS AT KINT AND
KGSO. SHOULD SEE SOME BROKEN CIGS AROUND 3500 FT MOVING INTO THE
AREA FROM WEST TO EAST...STARTING AROUND 08Z AT KINT AND KGSO AND
MAKING IT TOWARD KRWI AT THE END OF THE TAF PERIOD.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
MVFR CEILINGS MAY MAKE THEIR WAY INTO THE AREA FROM SW-NE OR W-E AS
THE STALLED FRONT LIFTS BACK THROUGH CENTRAL NC AS A WARM FRONT
DURING THE DAY TUE. A PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE
EARLY WED MORNING (06-12Z) IN ASSOC/W WARM ADVECTION UNDER THE
NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND STORMS ARE EXPECTED
DURING THE DAY WED IN ADVANCE OF ANOTHER BACKDOOR COLD FRONT
APPROACHING THE AREA FROM THE NORTH. A PROLONGED PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN ASSOC/W LOW-LEVEL
NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC/VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...KC/VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
149 AM EDT MON APR 2 2012
.SYNOPSIS...
A BACK DOOR COLD FRONT WILL PUSH SOUTHWEST THROUGH THE AREA TODAY
BEFORE STALLING OUT OVER THE WESTERN CAROLINAS TONIGHT. THE STALLED
BOUNDARY WILL LIFT NORTHEAST THROUGH CENTRAL NORTH CAROLINA AS A
WARM FRONT DURING THE DAY TUESDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1039 AM MONDAY...
UPDATE: CLEARING ALONG THE I-40 CORRIDOR HAS ALLOWED TEMPS TO REACH
THE LOW TO MID 70S IN THAT AREA. CLOUD COVER ACROSS THE SOUTHWEST
AND ALONG THE NC/VA BORDER HAVE KEPT TEMPS IN THE MID 60S. AS OF 14Z
THE BACKDOOR COLD FRONT WAS STRETCHED FROM DANVILLE VA SOUTH AND
EAST ACROSS THE AREA...HANGING OUT JUST EAST OF RDU... SMITHFIELD...
AND GOLDSBORO. DEWPOINTS BEHIND THE FRONT ARE CRASHING INTO THE 40S
AND LOW 50S...WITH TEMPS IN THE LOW TO MID 60S. SOME LIGHT SHOWERS
HAVE STARTED IMPINGE ON THE SOUTHWESTERN EXTENT OF THE AREA. THIS
CLOUD COVER AND SHOWERS MAY ACT TO KEEP TEMPS FROM RISING AS HIGH AS
PREVIOUSLY THOUGHT...THUS HAVE LOWERED HIGH ACROSS THE SOUTHWEST TO
AROUND 81 DEGREES. WITH THE CLEARING ACROSS THE I-40 CORRIDOR AND
TEMPS ALREADY IN THE LOW 70S HAVE INCREASED HIGHS SLIGHTLY TO THE
MID 70S.
PREVIOUS DISCUSSION:
OVERVIEW:
SURFACE HIGH PRESSURE WILL STRENGTHEN OVER THE OH VALLEY AND
MID-ATLANTIC TODAY/TONIGHT AS AN AMPLIFYING UPPER LEVEL TROUGH DIGS
SOUTHEAST OFF THE MID-ATLANTIC COAST AND AN UPPER LEVEL RIDGE
PROGRESSES FROM THE MS RIVER VALLEY INTO THE APPALACHIANS. PRESSURE
RISES UPSTREAM OF THE AREA WILL HELP PUSH A BACK DOOR COLD FRONT
(EXTENDING WEST-EAST THROUGH THE OH VALLEY AND NORTHERN VIRGINIAS AT
06Z) SOUTH/SW THROUGH CENTRAL NC TODAY...BEFORE STALLING OUT IN FAR
WESTERN NC AND UPSTATE SC TONIGHT.
PRECIPITATION CHANCES:
UPSTREAM CONVECTION OVER KY/WV/VA AT 06Z APPEARS TO BE DRIVEN BY A
COMBINATION OF WEAK LOW-LEVEL CONVERGENCE (IN VICINITY OF) AND WARM
ADVECTION (JUST AHEAD OF) THE AFOREMENTIONED FRONTAL ZONE...WITH
LITTLE OR NO HELP ALOFT. 06Z SPC MESOANALYSIS INDICATED NO MORE THAN
100-250 J/KG OF MUCAPE OVER CENTRAL NC...WITH THE BEST INSTABILITY
(~1000 J/KG MUCAPE) OVER CENTRAL TN/KY IN THE PRESENCE OF MORE
FAVORABLE BOUNDARY LAYER MOISTURE (SFC DEWPOINTS UPPER 50S) AND
STEEPER MID-LEVEL LAPSE RATES (7-8 C/KM). AS A RESULT...EXPECT
CONVECTION UPSTREAM OF THE AREA TO GENERALLY WEAKEN THROUGH 09Z AS
SPEEDY NORTHWEST FLOW ALOFT PUSHES ACTIVITY AWAY FROM THE BEST
LOW-LEVEL FORCING AND INTO A GENERALLY UNFAVORABLE THERMODYNAMIC
ENVIRONMENT OVER THE NC PIEDMONT. HOWEVER...A RESPECTABLE (25 KFT
ECHO TOPS) CONVECTIVE CELL THAT DEVELOPED JUST SOUTH OF DANVILLE
~07Z SUGGESTS THAT SUBTLE UPPER LEVEL FORCING IS PRESENT...AND/OR
THAT DEEP-LAYER SHEAR (40-50 KT) SUPPORTIVE OF UPDRAFT ROTATION MAY
BE ENHANCING UPDRAFTS. AS THE BACK DOOR COLD FRONT APPROACHES THE
AREA FROM THE N/NE THROUGH 12Z...LOW-LEVEL MOISTURE WILL BEGIN TO
INCREASE...AND SOME MARGINAL DESTABILIZATION IS EXPECTED.
DESTABILIZATION WILL BE MOST PROMINENT IN THE FAR SOUTHWEST PIEDMONT
(PERHAPS 500-750 J/KG MLCAPE) WHERE DIURNAL HEATING IS MOST LIKELY
TO BE A CONTRIBUTING FACTOR IN ADVANCE OF THE AFOREMENTIONED FROPA.
THE LATEST WRF-NMM SIMULATED REFLECTIVITY PRODUCT INDICATES A
BROKEN LINE OF CONVECTION DEVELOPING NEAR OR JUST SOUTH OF THE VA
BORDER AND PROGRESSING SOUTH/SW THROUGH CENTRAL NC IN ADVANCE OF THE
BACK DOOR FRONT BETWEEN ROUGHLY 09-12Z. WITH THE ABOVE IN MIND...
WILL INDICATE ISOLD TO SCT SHOWERS/STORMS ACROSS THE AREA THROUGH
~15Z...WITH THE BEST CHANCE IN THE NORTHERN PIEDMONT EARLY THIS
MORNING...TRANSITIONING TO THE WEST/SW PIEDMONT BY MID MORNING.
AFTER ~15Z...A COOL/STABLE AIRMASS ADVECTING INTO THE AREA FROM THE
NORTHEAST IN THE WAKE OF THE FRONT WILL EFFECTIVELY END PRECIP
CHANCES. HOWEVER...DEPENDING ON THE SPEED/PROGRESS OF THE BACK DOOR
FRONT...ISOLD CONVECTION MAY REMAIN POSSIBLE INTO THE AFTERNOON IN
THE FAR WEST/SW PIEDMONT AT THE EASTERN FRINGE OF THE INSTABILITY
GRADIENT. EXPECT PRECIP CHANCES NEAR ~0 EVEN IN THE WEST/SW PIEDMONT
BY 00Z THIS EVENING THROUGH SUNRISE TUE MORNING.
TEMPERATURES:
CHALLENGING TEMPERATURE FCST WITH A POTENTIAL TO BUST HIGHS BY
5-10F. HIGHS TODAY WILL DEPEND ENTIRELY ON THE TIMING OF THE
BACKDOOR COLD FRONTAL PASSAGE. THE LATEST 00Z GUIDANCE INDICATES
HIGHS RANGING FROM THE LOWER/MID 60S IN NORTHEAST NC (I.E. ELIZABETH
CITY/AHOSKIE) TO THE LOWER/MID 80S IN WEST/SOUTHWEST NC. WILL
INDICATE HIGHS RANGING FROM THE UPPER 60S/NEAR 70F IN THE FAR
NORTHEAST COASTAL PLAIN TO THE LOWER/MID 80S IN THE FAR SW PIEDMONT.
LOWS TONIGHT WILL BE EQUALLY CHALLENGING GIVEN THAT THE FRONT IS
EXPECTED TO STALL JUST WEST OF CENTRAL NC. EXPECT LOWS TO RANGE FROM
THE UPPER 30S/LOWER 40S IN THE E/NE COASTAL PLAIN TO THE LOWER 50S
IN THE WEST/SW PIEDMONT.
SEVERE THREAT:
0-6KM BULK SHEAR VALUES IN THE 40-50 KT RANGE ARE SUPPORTIVE OF
SUPERCELLS...THOUGH SEVERE WEATHER APPEARS UNLIKELY THROUGH SUNRISE
GIVEN BAD DIURNAL TIMING AND LITTLE IN THE WAY OF INSTABILITY. IN
FACT...STRONG NW FLOW ALOFT WILL LIKELY SHEAR APART ANY CONVECTION
THAT DEVELOPS PRIOR TO SUNRISE. HOWEVER...AN ISOLD SEVERE THREAT
(HAIL/WIND) WILL BE POSSIBLE IN THE SW PIEDMONT BETWEEN 12-18Z WHERE
INCREASING BOUNDARY LAYER MOISTURE AND DIURNAL HEATING IN ADVANCE OF
THE BACK DOOR FRONT WILL ALLOW MARGINAL DESTABILIZATION TO OCCUR IN
THE PRESENCE OF 0-6KM BULK SHEAR VALUES SUPPORTIVE OF SUPERCELLS.
ALTHOUGH 07Z SPC MESOANALYSIS INDICATED 300-400 M2/S2 OF 0-1 KM SRH
OVER CENTRAL NC...THE LATEST RUC GUIDANCE SHOWS 0-1KM SRH RAPIDLY
DIMINISHING TO LESS THAN 100 M2/S2 AFTER SUNRISE. THE RELATIVE BEST
CHANCE OF SEVERE WEATHER IS EXPECTED TO REMAIN SOUTH AND WEST OF THE
AREA IN SC AND SOUTHWEST NC TODAY...WHERE A MORE DIURNALLY FAVORABLE
FROPA WILL OCCUR. -VINCENT
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE STALLED FRONTAL ZONE WEST OF THE AREA WILL PROGRESS BACK TO THE
NORTHEAST AS A WARM FRONT ON TUE...AND EXPECT HIGHS TO BE MORE
HOMOGENEOUS THAN TODAY. GIVEN THE LIKELY PRESENCE OF SCT/BKN CLOUD
COVER BETWEEN 2000-4000 FT AGL IN ASSOC/W WARM ADVECTION...AND THAT
THE WARM FRONT WILL PROGRESS THROUGH THE AREA FROM SW-NE...EXPECT
HIGHS RANGING FROM THE MID 70S IN THE WEST/SW PIEDMONT TO THE UPPER
60S/LOWER 70S IN THE COASTAL PLAIN...THOUGH THIS WILL HIGHLY DEPEND
ON CLOUD COVER AND THE TIMING OF THE WARM FRONTAL PASSAGE. GIVEN THE
CLOSE PROXIMITY OF THE AFOREMENTIONED UPPER LEVEL RIDGE JUST WEST OF
CENTRAL NC AND A SUBSIDENCE INVERSION IN PLACE...IT MAY BE DIFFICULT
FOR CONVECTION TO DEVELOP DURING THE DAY TUE. HOWEVER...THE RIDGE IS
EXPECTED TO WEAKEN TUE NIGHT...WITH A POTENTIAL FOR UPPER LEVEL
DISTURBANCES PROGRESSING INTO THE AREA VIA W/NW FLOW ALOFT. AS A
RESULT...WILL CONTINUE TO INDICATE A SLIGHT CHANCE OF SHOWERS/STORMS
TUE NIGHT. GIVEN WARM ADVECTION OVERNIGHT...EXPECT LOWS IN THE MID
TO UPPER 50S. -VINCENT
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
ANOTHER UPPER TROUGH WILL DEVELOP OVER THE NORTHEAST US
WEDNESDAY...WHILE AN UPPER LOW OVER THE SOUTHWEST LIFTS NORTHEAST
BELOW THE UPPER RIDGE. THE WARM FROM FORECAST TO LIFT THROUGH
CENTRAL NC TUESDAY WILL STALL AND SHOULD STRETCH FROM THE MIDWEST
ACROSS THE MID ATLANTIC STATES WEDNESDAY MORNING...THEN
BEGIN TO PUSH SOUTH THROUGH VA WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED UPPER TROUGH DIGS ACROSS NEW ENGLAND. AHEAD OF THE
FRONT...DEEP LAYER WESTERLY FLOW SHOULD KEEP MUCH CENTRAL NC DRY
WEDNESDAY...BUT THE PRESENCE OF A PREFRONTAL LEE TROUGH AND THE
POTENTIAL FOR A WEAK UPPER DISTURBANCE ALOFT AND CONVECTIVE
OUTFLOW BOUNDARIES FROM THE NORTH WARRANTS AT LEAST A LOW END CHANCE
POP. FORECAST SOUNDINGS SHOW RELATIVELY WEAK MID LEVEL LAPSE RATES
AND DEEP LAYER SHEAR...BUT LOW LEVEL LAPSE RATES WILL LIKELY BE
RATHER STEEP AND COULD SUPPORT AN ISOLATED STRONG TO SEVERE WIND
THREAT.
THE WESTERLY FLOW WILL ALSO PUSH TEMPS THEIR HIGHEST VALUES
OF THE WEEK WEDNESDAY. DEEPER MIXING TO 850MB OR ABOVE WOULD YIELD
HIGHS IN THE LOW TO MID 80S...WHICH STATISTICAL GUIDANCE HAS BEEN
CREEPING TOWARD OVER THE PAST FEW RUNS. RECORD HIGHS FOR WEDNESDAY
ARE 86/87 AT GSO/RDU AND MAY BE JUST OUT OF REACH.
MODELS ARE IN DECENT AGREEMENT ON THE FRONT PUSHING BACKDOOR THROUGH
THE CWA WEDNESDAYS NIGHT AS HIGH PRESSURE BUILDS SOUTH OVER THE
GREAT LAKES. HOW FAR SOUTH THE FRONT FINALLY SETTLES WILL
DETERMINE WHETHER OR NOT THERE IS SUFFICIENT INSTABILITY TO SUPPORT
CONVECTION THURSDAY INTO FRIDAY AS THE UPPER LOW DRIFTING EAST
BENEATH THE RIDGE MOVES TOWARD THE TN VALLEY REGION. THE UPPER LOW
IS FORECAST TO WEAKEN AND DROP SOUTHEAST ACROSS GA/SC ON
FRIDAY...WHILE GFS FORECAST SOUNDINGS SHOW THE POTENTIAL FOR A WEAK
DAMMING EVENT OVER NC. THE GREAT LAKES HIGH IS FORECAST TO BE
MODESTLY STRONG AT 1025+ MB WHILE IT SHIFTS EAST ACROSS NEW
ENGLAND...SO WE SHOULD SE A PERIOD OF AT OR SLIGHTLY BELOW NORMAL
TEMPS THURSDAY THROUGH SATURDAY..WITH A WARMING TREND THROUGH THE
END OF THE WEEKEND AS THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE NORTH CENTRAL US. WE WILL KEEP POPS MOSTLY IN LINE WITH HPC
THURSDAY AND FRIDAY WITH HIGHER CHANCES TO THE SOUTH.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
AS OF 145 PM MONDAY...
24-HR TAF PERIOD:
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. AHEAD OF THE
BACKDOOR COLD FRONT WINDS WILL BE NNW AT 5-10 KT...WITH WINDS BEHIND
THE FRONT NNE AT 10-15 KT GUSTING UP TO 20 KT. EXPECT GUSTS TO DIE
DOWN AROUND SUNSET...WITH MAINLY EASTERLY WINDS AT 5 KTS OR LESS
ACROSS ALL TERMINALS THROUGH SUNRISE. SKIES WILL BE MAINLY CLEAR
OVERNIGHT WITH THE EXCEPTION OF SOME SCATTERED CLOUDS AT KINT AND
KGSO. SHOULD SEE SOME BROKEN CIGS AROUND 3500 FT MOVING INTO THE
AREA FROM WEST TO EAST...STARTING AROUND 08Z AT KINT AND KGSO AND
MAKING IT TOWARD KRWI AT THE END OF THE TAF PERIOD.
LOOKING AHEAD:
MVFR CEILINGS ARE PROGGED TO DEVELOP EARLY TUE MORNING (06-12Z) IN
VICINITY OF THE STALLED FRONT OVER UPSTATE SC AND SOUTHWEST NC.
MVFR CEILINGS MAY MAKE THEIR WAY INTO THE AREA FROM SW-NE OR W-E AS
THE STALLED FRONT LIFTS BACK THROUGH CENTRAL NC AS A WARM FRONT
DURING THE DAY TUE. A PERIOD OF MVFR/IFR CEILINGS WILL BE POSSIBLE
EARLY WED MORNING (06-12Z) IN ASSOC/W WARM ADVECTION UNDER THE
NOCTURNAL INVERSION. ISOLD TO SCT SHOWERS AND STORMS ARE EXPECTED
DURING THE DAY WED IN ADVANCE OF ANOTHER BACKDOOR COLD FRONT
APPROACHING THE AREA FROM THE NORTH. A PROLONGED PERIOD OF MVFR/IFR
CEILINGS WILL BE POSSIBLE THU THROUGH FRI IN ASSOC/W LOW-LEVEL
NORTHEAST FLOW IN THE WAKE OF THE AFOREMENTIONED COLD FRONT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...KC/VINCENT
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...KC/VINCENT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1254 PM CDT MON APR 2 2012
.DISCUSSION...MINOR UPDATES TO TEMPERATURES AND PRECIPITATION.
ADJUSTED TEMPERATURES LOWER ONCE AGAIN...WITH HIGHS MAINLY IN THE
UPPER 40S TO LOWER 50S. CLOUD DECK IS SLOW TO ERODE FROM THE
WEST...THUS KEEPING TEMPERATURES DOWN. THE FAR WEST WILL LIKELY
SEE SUNSHINE IN THE NEXT HOUR OR TWO AS THE CLOUD SHIELD MOVES
SLOWLY EAST...THUS THE FAR WEST MAY SEE SOME MIDDLE 50S.
LATEST HIGH RESOLUTION RUC LIFTS CURRENT CONVECTION NORTHWARD
THROUGH THE AFTERNOON...AS THE ENTIRE SYSTEM TRACKS SLOWLY EAST.
LOWERED POPS OVER THE FAR SOUTHEAST...KEEPING HIGHEST POPS FROM
WESTERN MCINTOSH THROUGH STUTSMAN COUNTIES. ALSO MENTIONED
SCATTERED SPRINKLES INTO THE EVENING OVER CENTRAL NORTH DAKOTA.
THERE HAVE BEEN SOME SPRINKLES REACHING THE GROUND UNDER THE
ELEVATED REFLECTIVITIES ACROSS THE WEST.
&&
.AVIATION...TROUGH OF LOW PRESSURE EXTENDING NORTH THROUGH THE
EASTERN DAKOTAS WILL CONTINUE TO RESULT IN EXTENSIVE VFR
CLOUDINESS THROUGH THIS AFTERNOON ACROSS CENTRAL AND EASTERN
PORTIONS OF NORTH DAKOTA. SHOULD SEE SKIES TRENDING TOWARDS SCT-
SKC AFTER 21Z WEST...THEN SCT-SKC CENTRAL 02-05Z. -SHRA WILL END
BY 20Z SOUTHWEST AND CENTRAL AROUND 00Z. LINE OF ENHANCED SHOWERS
AND THUNDERSTORMS AND MVFR CIGS FROM KMBG TO KJMS WILL SLOWLY LIFT
NORTH WITH TIME THIS AFTERNOON. WILL CONTINUE TO MENTION VCTS AT
KJMS THROUGH 01Z. STRONG NORTH WINDS WITH GUSTS BETWEEN 30-40KTS
EXPECTED AT KBIS AND KJMS THROUGH 23-00Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CDT /6 PM MDT/ THIS EVENING FOR NDZ020-
034>037-042-045>048-050-051.
WIND ADVISORY UNTIL 3 PM MDT THIS AFTERNOON FOR NDZ033-040-041-
043-044.
&&
$$
SHORT TERM...TWH
AVIATION...NH
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1133 AM CDT MON APR 2 2012
.DISCUSSION.../ISSUED AT 1133 AM CDT/
SLOW MOVING COLD FRONT ACROSS OUR FAR WESTERN ZONES IS NEARLY
STATIONARY THIS MORNING AND THE SURFACE LOW BUILDS NORTHWARD OVER
THE CWA. EXPECT THIS FRONT TO REMAIN NEARLY STATIONARY INTO THE
EARLY AFTERNOON BEFORE FINALLY TRACKING EASTWARD MID AFTERNOON INTO
THE LATE EVENING. MEANWHILE STRATUS HAS FINALLY BEGUN TO RAPIDLY
ERODE ACROSS OUR NORTHEASTERN THIRD. TEMPERATURES RAPIDLY JUMPING
IN THE CLEAR AREA BETWEEN THESE STRATUS FIELDS WITH TEMPERATURES
ALREADY IN THE UPPER 70S INTO OUR EXTREME SOUTHEASTERN ZONES.
UPDATED TEMPERATURES ACROSS NW IA AND INTO THE I29 CORRIDOR WHERE
SKIES WILL REMAIN PREDOMINATELY CLEAR INTO THE AFTERNOON AND THETA E
ADVECTION IS PRETTY STRONG. COULD SEE ANOTHER DAY WELL INTO THE 80S
IN PARTS OF THIS AREA. ALSO UPDATED TO SLOW DOWN THE DEVELOPMENT OF
THE ISOLATED SHOWERS/SPRINKLES WITH THE SLOWER FRONTAL PROGRESSION.
AHEAD OF THE FRONT...STRONG CAP LOOKS TO DOMINATE OUR EASTERN HALF
WHICH WILL MAKE THUNDERSTORM DEVELOPMENT PROBLEMATIC THROUGH AT
LEAST LATE THIS AFTERNOON. STILL...CANNOT RULE OUT SOME ISOLATED
ELEVATED THUNDERSTORM DEVELOPMENT IN THE LATE AFTERNOON AND EARLY
EVENING ACROSS OUR FAR EASTERN AREAS. WITH GOOD
INSTABILITY...ENHANCEMENT OF THE LOW LEVEL JET AND GOOD MID LEVEL
LAPSE RATES A FEW MARGINALLY SEVERE STORMS ARE A POSSIBILITY IF
DEVELOPMENT DOES OCCUR.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/
IFR/MVFR STRATUS AND AREAS OF FOG ACROSS THE EASTERN AND NORTH
CENTRAL ZONES QUICKLY LIFTING LATE THIS MORNING. VISIBILITY AND
CEILINGS WILL IMPROVE TO VFR FROM WEST TO EAST IN THIS AREA INTO THE
EARLY AFTERNOON. MEANWHILE A SLOW MOVING FRONT ACROSS CENTRAL SOUTH
DAKOTA WILL GRADUALLY TRACK EASTWARD ACROSS THE FORECAST AREA
THROUGH THE LATE EVENING. STRATUS WILL FOLLOW BEHIND THIS FRONT
ALONG WITH A SMALL POTENTIAL FOR LIGHT RAIN SHOWERS OR SPRINKLES.
WINDS WILL FLIP TO THE NORTH NORTHWEST BEHIND THE FRONT AND BECOME
QUITE STRONG THIS AFTERNOON AND EVENING...AROUND 25 TO 35 KT WITH
POSSIBLY A FEW GUSTS AROUND 40 KT IN THE JAMES VALLEY AND WESTWARD.
ELSEWHERE...WINDS WILL BECOME BREEZY BEHIND THE FRONT THIS EVENING
AND OVERNIGHT. THERE IS A SMALL POTENTIAL FOR SOME THUNDERSTORM
DEVELOPMENT THIS EVENING ACROSS PARTS OF NORTHWEST IOWA TOWARDS
SOUTH CENTRAL MINNESOTA.
&&
.PREV DISCUSSION.../ISSUED AT 500 AM CDT/
CURRENTLY SEEING A COLD FRONT PUSHING INTO OUR WESTERN CWA...HAVING
JUST PUSHED THROUGH CHAMBERLAIN...AND A WARM FRONT DRAPED FROM EAST
OF HURON SOUTH ACROSS SIOUX FALLS INTO NORTHWEST IOWA. EXPECTATION
IS THAT THIS WARM FRONT WILL CONTINUE TO SLOWLY DRIFT
SOUTHWEST...WITH THE AREA OF LOW STRATUS ACCOMPANYING IT. GUIDANCE
CONTINUES TO SLOW DOWN THE PROGRESSION OF THE COLD FRONT. MODELS
COMING INTO AGREEMENT THAT IT WILL WILL SLOWLY PUSH EAST THROUGH THE
DAY...NOT PASSING THROUGH SIOUX FALLS UNTIL 20-22Z...AND THE EASTERN
EDGE OF THE CWA 2-4Z. THIS WILL IMPACT TODAYS TEMPERATURE AND WIND
POTENTIAL.
TEMPERATURES ARE A BIG QUESTION MARK WITH A LARGE SPREAD IN THE
GUIDANCE TODAY. WITH THE SLOWER ARRIVAL OF THE COLD FRONT...RAISED
TEMPERATURES SEVERAL DEGREES IN THE WEST. MEANWHILE...FROM SIOUX
FALLS TO SIOUX CITY AND POINTS EAST...TEMPERATURES DEPEND ON
PROGRESSION OF THE WARM FRONT AND ATTENDANT LOW CLOUDS. THE HRRR HAS
PERFORMED FAIRLY WELL THE PAST COUPLE DAYS WITH THE EVOLUTION OF
THE WARM FRONT AND CLOUDS. IT LIFTS THE FRONT NORTH ALMOST THROUGH
THE ENTIRE CWA...RESULTING IN HIGHS IN THE 80S FROM YANKTON TO SIOUX
FALLS AND POINTS EAST...WITH NEAR 90 ONCE AGAIN IN SIOUX CITY. THIS
IS THE WARMEST MODEL SOLUTION...BUT THE NAM AND ECMWF ARE ONLY A FEW
DEGREES COOLER. THE LOW LEVEL MOISTURE AND STRATUS WILL BE A BIT
DEEPER THIS MORNING COMPARED TO LAST...SO THINK IT MAY TAKE A BIT
LONGER FOR CLOUDS TO ERODE. BUT GIVEN WHAT HAS HAPPENED THE PAST FEW
DAYS...THE SLOWER COLD FRONT...AND MODEL AGREEMENT...CURRENT
THINKING IS THAT THEY DO INDEED ERODE...ALLOWING FOR ANOTHER VERY
WARM DAY WITH HIGHS IN THE UPPER 70S TO MID 80S ACROSS EXTREME
SOUTHEAST SOUTH DAKOTA AND NORTHWEST IOWA. GIVEN UNCERTAINTY...DID
NOT GO QUITE AS WARM AS WARMEST SOLUTIONS...BUT WOULD NOT BE
SURPRISED IF TEMPS END UP A FEW DEGREES WARMER THAN CURRENT
FORECAST. ON THE OTHER HAND...IF THE LOW CLOUDS STAY LOCKED IN
TEMPERATURES WILL BE MUCH COOLER THAN FORECAST...ALTHOUGH SEE THIS
AS A LOWER PROBABILITY EVENT AT THIS TIME.
NEXT UP IS THE WINDS. WINDS WILL BECOME STRONG BEHIND THE COLD
FRONT. 900MB WINDS ARE EXPECTED TO BE IN THE 30 TO 40 KTS RANGE. THE
COMBINATION OF DECENT LOW LEVEL CAA AND PRESSURE RISES WILL HELP
PROMOTE MIXING AND THE TRANSFER OF THESE WINDS TO THE SURFACE. A
BORDERLINE WIND ADVISORY EVENT...BUT WILL KEEP THE CURRENT ADVISORY
MAINLY AS IS...WITH SUSTAINED WINDS APPROACHING 30 MPH FOR A PERIOD
IN THE WEST...WITH A FEW GUSTS AROUND 40 MPH. DID CUT ONE ROW OF
COUNTIES OFF THE ADVISORY GIVEN THE SLOWER MOVEMENT OF THE FRONT AND
A SLIGHTLY WEAKER CORE OF LOW LEVEL WINDS.
PRECIP CHANCES LOOK TO BE CLOSE TO ZERO OUT AHEAD OF THE FRONT. SOME
ELEVATED CAPE IN OUR FAR NORTHWEST...BUT A STRONG CAPPING INVERSION
AROUND 750MB WILL PREVENT ANY ELEVATED CONVECTION. DEEP LOW LEVEL
MOISTURE BEHIND THE FRONT WILL ALLOW FOR DRIZZLE AND LIGHT
SHOWERS...MAINLY NORTH OF INTERSTATE 90 AND WEST OF INTERSTATE 29.
EXPECT THIS AREA OF DRIZZLE TO BEGIN TO DISSIPATE TONIGHT AS THE
MOISTURE LAYER BECOMES SHALLOW AND BEGINS TO ERODE AWAY FROM WEST TO
EAST. NAM AND GFS BOTH SHOWING DECENT ELEVATED CAPE BEHIND THE COLD
FRONT FROM PARCELS UP AROUND 750MB. IT LOOKS LIKE WE SHOULD REMAIN
CAPPED...HOWEVER STRONG LOW LEVEL LIFT GENERATED BY THE DEVELOPING
LOW PRESSURE AND THETAE ADVECTION MAY ATTEMPT TO BREAK THIS CAP. AND
WITH MOISTURE UP TO 750MB...NOT OUT OF THE QUESTION THAT THOSE
PARCELS GO AND WE GET A THUNDERSTORM. BEST CHANCE OF THIS APPEARS TO
BE ACROSS SOUTHWEST MINNESOTA BETWEEN 0Z AND 6Z...WHERE THE LIFT IS
STRONGEST AND MOISTURE DEEPEST. OTHER CONCERN IS ACROSS NORTHWEST
IOWA. WITH THE VERY WARM TEMPERATURES WILL LIKELY SEE CAPES AROUND
2000 J/KG THIS AFTERNOON. HOWEVER EXPECT THE STRONG MID LEVEL CAP TO
HOLD. IF WE GET HOTTER THAN FORECAST THE DEEPER MIXING SHOULD RESULT
IN LOWER DEWPOINTS...WITH THE NET RESULT OF BEING CAPPED STAYING THE
SAME. THIS IS SUPPORTED BY THE NAM AND HRRR.
SHORTWAVE RIDGING SHOULD PROVIDE A DRY DAY TUESDAY. OUR NEXT WEATHER
FEATURE IS A CUT OFF LOW ACROSS THE SOUTHERN PLAINS. NAM...GFS AND
ECMWF HAVE SIMILAR TRACKS OF THE UPPER LEVEL LOW ACROSS KANSAS. THIS
SHOULD PUT AT LEAST OUR SOUTHERN CWA IN DECENT QG FORCING LATE
TUESDAY NIGHT INTO WEDNESDAY. MODELS DIVERGE ON HOW THEY HANDLE
MOISTURE ADVECTION INTO THE AREA. WITH STRONGER SHORTWAVE RIDGING
AND HIGH PRESSURE TO THE NORTH...ECMWF AND SREF KEEP THE DEEPER
MOISTURE AND PRECIP TO OUR SOUTH...WHILE THE GFS AND NAM PUSH IT UP
TO INTERSTATE 90 ON WEDNESDAY. GIVEN MODEL UNCERTAINTY WILL BLEND
THE TWO SOLUTIONS...TRENDING A BIT CLOSER TO THE ECMWF AND SREF
SOLUTIONS.
THURSDAY AND MOST OF FRIDAY SHOULD REMAIN DRY WITH AN UPPER LEVEL
RIDGE OVERHEAD. ANOTHER SHORTWAVE WILL PUSH ACROSS LATER FRIDAY INTO
SATURDAY BRINGING OUR NEXT CHANCE OF SHOWERS AND POSSIBLY A
THUNDERSTORM.
HIGH TEMPERATURES TUESDAY THROUGH SUNDAY LOOK GENERALLY IN THE UPPER
50S TO LOWER 60S...WITH MODELS IN FAIRLY GOOD AGREEMENT WITH THESE
VALUES. LOW TEMPERATURES SHOULD BE IN THE UPPER 30S TO LOWER 40S.
DEPENDING ON WHAT EXACTLY HAPPENS WITH THE UPPER LOW ON
WEDNESDAY...TEMPERATURES MAY NEED TO BE ADJUSTED UP A FEW DEGREES IF
THE SOUTHERN SOLUTION PANS OUT...OR DOWN IF THE SHOWERS ARE MORE
WIDESPREAD. /CHENARD
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...WIND ADVISORY FROM 10 AM TO 9 PM CDT MONDAY FOR SDZ038-039-
052>054-058>061-064>066-068-069.
WIND ADVISORY FROM 7 AM TO 9 PM CDT MONDAY FOR SDZ050-057-063.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
519 PM CDT MON APR 2 2012
.UPDATE...
A QUICK UPDATE WAS SENT TO REMOVE WW127...THE SEVERE THUNDERSTORM
WATCH THAT COVERED SOME OF THE EASTERN NORTH TEXAS UNTIL 7 PM.
SHOWERS AND THUNDERSTORMS NORTHEAST OF A SHERMAN TO SULPHUR
SPRINGS LINE WILL CONTINUE TO MOVE NORTHEAST AND SEVERE WEATHER
IS NOT EXPECTED TO DEVELOP ACROSS THE AREA PREVIOUSLY IN WW127.
OUR EYES WILL NOW BE TRAINED ALONG THE DRYLINE WHERE ACTIVITY IS
EXPECTED TO DEVELOP DURING THE NEXT HOUR.
58
&&
.PREV DISCUSSION... /ISSUED 307 PM CDT MON APR 2 2012/
MAIN UPPER LOW FEATURE SITS ACROSS CENTRAL NEW MEXICO. WEAK LOBE
THAT WAS NEAR TX COAST YESTERDAY HAS ROTATED NORTH AND SITS OVER
THE DFW METROPLEX. CIRCULATION AROUND THE WEAK LOW AND ASSOCIATED
SHORT WAVE HAS FIRED OFF SEVERE STORMS IN EASTERN NORTH
TEXAS...BUT AS THIS SYSTEM MOVES ON NORTH WE FEEL THAT THE DRY
LINE WILL BECOME THE MAIN PLAYER FOR TONIGHT AND TOMORROW.
GUIDANCE AGREES ON A GENERAL SOLUTION OF THE UPPER LOW PUSHING
EAST AND THEN NORTHEAST TO LIE OVER THE TX/OK PANHANDLES ON
TUESDAY. THE UPPER LOW MOVEMENT PUSHES THE DRY LINE ACROSS NORTH
TEXAS ON TUESDAY AS WELL. THE DISAGREEMENT IS ABOUT HOW
CONVECTION WILL EVOLVE WITH THE SYSTEM.
THE LATEST RUC ACTIVATES THE DRY LINE EARLY THIS EVENING. THE NAM
INITIATES DRY LINE CONVECTION WELL AFTER MIDNIGHT AS DOES THE
LATEST HRRR. WITH SOME CU ALREADY DEVELOPING WEST OF THE
CWA...WILL STICK WITH OUR PREVIOUS SOLUTION WHICH AGREES WITH THE
RUC AND THE GFS FOR DRY LINE CONVECTION THIS AFTERNOON/EVENING
MOVING INTO NORTHWEST COUNTIES.
EITHER CONVECTION WILL MAINTAIN IN SOME FORM OVERNIGHT AND
REINVIGORATE TOMORROW WITH DAYTIME HEATING...OR IT MAY DIE OUT
AND REGENERATE TOMORROW. EITHER WAY...WE HAVE HIGHER CONFIDENCE
OF A LINEAR FEATURE DEVELOPING DURING THE DAY TOMORROW AS THE DRY
LINE PUSHES EAST. WITH STEEP LAPSE RATES LARGE HAIL AND DAMAGING
WINDS ARE LIKELY TO OCCUR. STORMS SHOULD SWEEP EAST OF THE AREA
BY LATE EVENING OR EARLY WEDNESDAY MORNING...AND POPS END SUNRISE
WEDNESDAY. THE NAM IS AN OUTLIER...HOLDING THE DRY LINE BACK
ABOUT 8 HOURS BEHIND THE GFS...AND IF THIS OCCURS WE WOULD HAVE
TO ADD POPS FOR WEDNESDAY MORNING.
SHORT WAVE RIDGING MOVES IN WEDNESDAY AFTERNOON...AND NORTH TX
SHOULD REMAIN DRY THROUGH SUNDAY MORNING...WHEN A NEW FRONT IS
EXPECTED TO DROP INTO THE AREA AND INCREASE THE POPS A BIT. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 66 81 54 80 55 / 40 60 40 5 0
WACO, TX 67 79 54 83 55 / 20 60 30 5 0
PARIS, TX 65 79 59 81 54 / 20 50 60 10 0
DENTON, TX 65 79 54 78 54 / 40 60 30 5 0
MCKINNEY, TX 66 81 54 80 55 / 30 60 40 5 0
DALLAS, TX 66 82 55 81 55 / 30 60 40 5 0
TERRELL, TX 66 80 60 80 55 / 20 60 50 10 0
CORSICANA, TX 67 81 61 81 55 / 20 60 50 10 0
TEMPLE, TX 67 78 58 84 55 / 20 60 30 5 0
MINERAL WELLS, TX 64 77 53 81 52 / 50 40 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/58
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
307 PM CDT MON APR 2 2012
.DISCUSSION...
MAIN UPPER LOW FEATURE SITS ACROSS CENTRAL NEW MEXICO. WEAK LOBE
THAT WAS NEAR TX COAST YESTERDAY HAS ROTATED NORTH AND SITS OVER
THE DFW METROPLEX. CIRCULATION AROUND THE WEAK LOW AND ASSOCIATED
SHORT WAVE HAS FIRED OFF SEVERE STORMS IN EASTERN NORTH
TEXAS...BUT AS THIS SYSTEM MOVES ON NORTH WE FEEL THAT THE DRY
LINE WILL BECOME THE MAIN PLAYER FOR TONIGHT AND TOMORROW.
GUIDANCE AGREES ON A GENERAL SOLUTION OF THE UPPER LOW PUSHING
EAST AND THEN NORTHEAST TO LIE OVER THE TX/OK PANHANDLES ON
TUESDAY. THE UPPER LOW MOVEMENT PUSHES THE DRY LINE ACROSS NORTH
TEXAS ON TUESDAY AS WELL. THE DISAGREEMENT IS ABOUT HOW
CONVECTION WILL EVOLVE WITH THE SYSTEM.
THE LATEST RUC ACTIVATES THE DRY LINE EARLY THIS EVENING. THE NAM
INITIATES DRY LINE CONVECTION WELL AFTER MIDNIGHT AS DOES THE
LATEST HRRR. WITH SOME CU ALREADY DEVELOPING WEST OF THE
CWA...WILL STICK WITH OUR PREVIOUS SOLUTION WHICH AGREES WITH THE
RUC AND THE GFS FOR DRY LINE CONVECTION THIS AFTERNOON/EVENING
MOVING INTO NORTHWEST COUNTIES.
EITHER CONVECTION WILL MAINTAIN IN SOME FORM OVERNIGHT AND
REINVIGORATE TOMORROW WITH DAYTIME HEATING...OR IT MAY DIE OUT
AND REGENERATE TOMORROW. EITHER WAY...WE HAVE HIGHER CONFIDENCE
OF A LINEAR FEATURE DEVELOPING DURING THE DAY TOMORROW AS THE DRY
LINE PUSHES EAST. WITH STEEP LAPSE RATES LARGE HAIL AND DAMAGING
WINDS ARE LIKELY TO OCCUR. STORMS SHOULD SWEEP EAST OF THE AREA
BY LATE EVENING OR EARLY WEDNESDAY MORNING...AND POPS END SUNRISE
WEDNESDAY. THE NAM IS AN OUTLIER...HOLDING THE DRY LINE BACK
ABOUT 8 HOURS BEHIND THE GFS...AND IF THIS OCCURS WE WOULD HAVE
TO ADD POPS FOR WEDNESDAY MORNING.
SHORT WAVE RIDGING MOVES IN WEDNESDAY AFTERNOON...AND NORTH TX
SHOULD REMAIN DRY THROUGH SUNDAY MORNING...WHEN A NEW FRONT IS
EXPECTED TO DROP INTO THE AREA AND INCREASE THE POPS A BIT. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 66 81 54 80 55 / 40 60 40 5 0
WACO, TX 67 79 54 83 55 / 20 60 30 5 0
PARIS, TX 65 79 59 81 54 / 20 50 60 10 0
DENTON, TX 65 79 54 78 54 / 40 60 30 5 0
MCKINNEY, TX 66 81 54 80 55 / 30 60 40 5 0
DALLAS, TX 66 82 55 81 55 / 30 60 40 5 0
TERRELL, TX 66 80 60 80 55 / 20 60 50 10 0
CORSICANA, TX 67 81 61 81 55 / 20 60 50 10 0
TEMPLE, TX 67 78 58 84 55 / 20 60 30 5 0
MINERAL WELLS, TX 64 77 53 81 52 / 50 40 10 5 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
249 PM CDT MON APR 2 2012
.SHORT TERM...THROUGH WEDNESDAY NIGHT
249 PM CDT MON APR 2 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TONIGHT INTO
TUESDAY.
SURFACE ANALYSIS THIS AFTERNOON SHOWS AN AREA OF LOW PRESSURE OVER
SOUTHEAST SOUTH DAKOTA. A WARM FRONT EXTENDED SOUTHEAST FROM THE
LOW ACROSS IOWA INTO CENTRAL ILLINOIS.
WATER VAPOR SATELLITE SHOWS UPPER LEVEL RIDGING REMAINS OVER THE
UPPER MIDWEST TODAY. THE CONCERN FOR TONIGHT IS WHAT IS GOING TO
HAPPEN TO THIS RIDGE. THE CONSENSUS OF THE 02.12Z MODELS IS THAT
IT IS PRETTY MUCH GOING TO STAY IN PLACE AS IT IS BLOCKED FROM
MOVING EAST BY A LONG WAVE TROUGH JUST OFF THE EAST COAST.
HOWEVER...THE NORTHERN EXTENT OF THE RIDGE SHOULD GET FLATTENED
SOME AS THE NORTHERN STREAM SYSTEM OVER SOUTHERN CANADA CONTINUES
TO MOVE EAST PRODUCING SOME HEIGHT FALLS OVER NORTHERN MINNESOTA
AND WISCONSIN. THE 02.00Z ECMWF HAS BEEN THE MOST CONSISTENT WITH
THE HANDLING OF THIS SYSTEM AND THE 02.12Z NAM NOW HAS COME INTO
GOOD AGREEMENT WITH THE ECMWF. AS THE SHORT WAVE TROUGH MOVES BY
LATE TONIGHT...IT WILL PRODUCE THOSE MINOR HEIGHT FALLS WITH
POSSIBLY UP TO 2 PVU/S OF VORTICITY ADVECTION IN THE 500-300 MB
LAYER ACROSS NORTHERN WISCONSIN. THE SURFACE LOW IS EXPECTED TO
EITHER TRACK ACROSS SOUTHERN MINNESOTA OR NORTHERN IOWA AS IT
MOVES TOWARD NORTHERN ILLINOIS BY TUESDAY MORNING. THIS SHOULD
ALLOW THE WARM FRONT TO GET LIFTED INTO THE SOUTHERN PORTIONS OF
THE FORECAST AREA WITH WEAK TO MODERATE FRONTOGENESIS OCCURRING
NORTH OF THE FRONT LATE TONIGHT. THE WARM AIR ADVECTION OVER THE
WARM FRONT WILL PRODUCE PERSISTENT UP GLIDE OF 1 TO 4 UBAR/S ON
THE 305K ISENTROPIC SURFACE. A LOT OF THIS UP GLIDE WILL INITIALLY
GO INTO SATURATION AND BY THE TIME SATURATION OCCURS THE BEST UP
GLIDE WILL BE MOVING OFF TO THE EAST OF THE AREA.
THE WILD CARD IN WHERE THE CONVECTION WILL DEVELOP TONIGHT IS THE
WARM FRONT. THE 02.12Z GFS HAS BEEN CONSISTENTLY FARTHER SOUTH
WITH THE NOSE OF THE MOISTURE TRANSPORT AND LOW LEVEL JET INTO THE
FRONT AROUND THE I90 CORRIDOR. THE NAM AND ECMWF INDICATE THE LOW
LEVEL JET AND MOISTURE TRANSPORT WILL CONTINUE PAST THE FRONT AND
CONTINUE FARTHER NORTH CLOSER TO THE SHORT WAVE TROUGH. THIS
SCENARIO HAS MOST OF THE CONVECTION DEVELOPING ACROSS THE NORTHERN
PARTS OF THE AREA INTO NORTHERN WISCONSIN AND THEN TRANSLATING
INTO NORTHEAST AND EASTERN WISCONSIN AS THE LOW LEVEL JET BENDS
OVER TO THE EAST. THE NAM SUGGESTS THERE COULD BE AROUND 750 J/KG
OF ELEVATED CAPE ABOVE 2KM FOR THE STORMS TO WORK WITH. THE 0-3KM
SHEAR SHOULD BE AROUND 30 TO 35 KNOTS BUT TAKING OUT THE LOWEST
1KM OF THIS SINCE THE STORMS WILL BE ELEVATED BRINGS THIS DOWN TO
15 TO 20 KNOTS. THIS IS NOT EXPECTED TO BE ENOUGH SHEAR TO ALLOW
THE STORMS THAT FORM TO PRODUCE ANY SEVERE WEATHER BUT WITH
PRECIPITABLE WATERS EXPECTED TO BE 200-250 PERCENT OF NORMAL...CAN
NOT RULE OUT SOME LOCALIZED HEAVY RAINS.
THE 02.12Z HIRES ARW AND NMM ALONG WITH THE 02.16Z HRRR ARE IN
VERY GOOD AGREEMENT WITH THE NAM AND ECMWF INITIATING THE
CONVECTION THIS EVENING FARTHER TO THE NORTH AS THE MOISTURE
TRANSPORT OVERRUNS THE WARM FRONT. HAVE THUS MAINTAINED THE IDEA
THAT THE BEST CHANCES FOR CONVECTION WILL BE ACROSS THE NORTHERN
PARTS OF THE AREA AND AFTER MIDNIGHT AS THE WEAK FORCING FROM THE
SHORT WAVE TROUGH APPROACHES. WILL KEEP A SMALL CHANCE OF RAIN IN
THE FORECAST FOR THIS EVENING AS THE WARM FRONT APPROACHES ACROSS
MOST OF THE AREA. MAINTAINED THE 30 TO 50 PERCENT CHANCES FOR
AFTER MIDNIGHT TAPERING BACK TO JUST A 20 PERCENT CHANCE ACROSS
THE EAST TUESDAY MORNING FOR ANY LINGERING SHOWERS. THE FRONT
SHOULD BE FAR ENOUGH SOUTH TO HAVE A DRY TUESDAY AFTERNOON. AFTER
THAT...HIGH PRESSURE WILL BUILD IN TO BRING SOME COOLER
TEMPERATURES AND DRIER AIR. DID NOT ADD ANY FROST TO THE FORECAST
FOR TUESDAY NIGHT OR WEDNESDAY NIGHT AS TEMPERATURES AND DEW POINTS
ARE EXPECTED TO MAINTAIN A 5 TO 10 DEGREE SPREAD. THERE SHOULD
ALSO BE SOME WINDS BOTH NIGHT TO CREATE SOME MIXING AND THE
COMBINATION OF THE WINDS AND DRIER AIR SHOULD PRECLUDE FROST
FORMATION. PORTIONS OF CENTRAL WISCONSIN NORTH OF THE I94 CORRIDOR
COULD POSSIBLY SEE SOME FREEZING TEMPERATURES BOTH OF THESE NIGHTS.
.LONG TERM...THURSDAY THROUGH MONDAY
249 PM CDT MON APR 2 2012
THE HIGH WILL REMAIN OVER THE REGION THROUGH FRIDAY MAINTAINING THE
POSSIBILITY OF SOME FROST AND FREEZING TEMPERATURES AT NIGHT FOR
THE END OF THE WEEK. THE HIGH WILL THEN MOVE OFF FOR THE WEEKEND
AS THE NEXT SYSTEM COMES INTO THE AREA. SOME TIMING DIFFERENCES
BETWEEN THE 02.12Z GFS...ECMWF AND GEM WITH THE COLD FRONT COMING
ACROSS. THE ECMWF AND GEM ARE A LITTLE FASTER BUT ALL SHOW AT
LEAST A CHANCE FOR SOME RAIN SATURDAY INTO SATURDAY NIGHT BEFORE
IT MOVES OFF TO THE EAST FOR SUNDAY. SOME DIFFERENCES FOR NEXT
MONDAY WITH THE ECMWF DROPPING ANOTHER SHORT WAVE TROUGH OVER THE
AREA FOR THE POSSIBILITY OF SOME SHOWERS WHILE THE GFS IS DRY WITH
HIGH PRESSURE BUILDING IN. WILL HONOR THE ECMWF WITH A SMALL RAIN
CHANCE FOR MONDAY.
&&
.AVIATION...THROUGH 18Z TUESDAY
1233 AM CDT MON APR 2 2012
MAIN FORECAST CHALLENGE IS ON CEILING HEIGHTS THROUGH THE TAF
PERIOD AND CONVECTIVE POTENTIAL TONIGHT. A NARROW BAND OF VFR
CLOUDS WAS PUSHING THROUGH THE KLSE TAF SITE AND SHOULD PUSH OUT
BY EARLY AFTERNOON. VFR CONDITIONS THEN EXPECTED THROUGH MUCH OF
THE NIGHT TONIGHT. AN AREA OF LOW PRESSURE WILL MOVE INTO NORTHERN
IOWA TONIGHT. MOISTURE TRANSPORT FOCUSES INTO NORTHERN MINNESOTA
THIS EVENING AND THEN NORTHERN WISCONSIN OVERNIGHT AHEAD OF THE
LOW. EXPECT CONVECTION TO DEVELOP IN THESE AREAS...BUT AT THIS
POINT LOOKS LIKE IT SHOULD REMAIN NORTH OF THE TAF SITES. DID ADD
MENTION OF VCSH FROM 10Z-15Z DUE TO THE UNCERTAINTY. SURFACE
BOUNDARY LOOKS TO MOVE THROUGH THE TAF SITES 11-12Z ACCOMPANIED
BY LOWER MVFR CEILINGS...WHICH WILL PERSIST THROUGH 18Z TUESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
249 PM CDT MON APR 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1233 PM CDT MON APR 2 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
330 AM CDT MON APR 2 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES THROUGH TUESDAY
AND TEMPERATURES.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP ALONG THE WEST COAST OF THE U.S....
TROUGHING SPLITTING INTO TWO FROM WESTERN MONTANA INTO ARIZONA...AND
STRONG RIDGING ACROSS THE ENTIRE MISSISSIPPI RIVER VALLEY NORTH INTO
WESTERN HUDSON BAY. STRONG WARM ADVECTION PATTERN TAKING PLACE UNDER
THE UPPER RIDGE WITH SOUTHWEST 850MB WINDS OF 30-60 KT FROM KANSAS
INTO SOUTHERN MINNESOTA PER PROFILER/VWP DATA. 00Z SOUNDINGS AT MPX
AND ABR SAW THEIR 850MB TEMPS RISE 3C COMPARED TO THEIR PREVIOUS 12Z
ONES...NOW AT 15C AND 20C RESPECTIVELY. TIGHT THERMAL GRADIENT
REMAINS...THOUGH...WITH GRB AND INL REPORTING AROUND 5C AND APX AT
-1C AT 00Z. THE WARM ADVECTION ALOFT PLUS PLENTY OF DRY AIR SEEN ON
THE 00Z MPX AND OAX SOUNDINGS HAS KEPT THE ATMOSPHERE CAPPED TO
CONVECTION. NEAREST CONVECTION IS NEAR DULUTH INTO FAR NORTHERN
WISCONSIN...ON THE NOSE OF THAT 850MB JET. BELOW THE WARM ADVECTION
SEEN AT 850MB...A COOL/DRY LOW LEVEL EASTERLY FLOW CONTINUES...
BETWEEN HIGH PRESSURE SITUATED OVER NORTHEAST ONTARIO AND A SURFACE
WARM FRONT THAT STRETCHES FROM NEAR ABERDEEN SD TO JUST SOUTH OF DES
MOINES IA AND ST LOUIS MO. AN AREA OF STRATUS LEFTOVER FROM
YESTERDAY AFTERNOON IN NORTHERN ILLINOIS HAS ADVECTED ON
EAST-SOUTHEAST WINDS...NOW ENCOMPASSING SOUTHWEST MINNESOTA INTO
NORTH CENTRAL IOWA. TEMPERATURES SO FAR HAVE FALLEN INTO THE MID 40S
TO MID 50S. SOUTH AND WEST OF THE AFOREMENTIONED WARM FRONT...
READINGS ARE IN THE MID TO UPPER 60S.
TODAY AND TONIGHT...WHAT LOOKED LIKE IN PREVIOUS DAYS OF 500MB
HEIGHTS FALLING THROUGHOUT THIS PERIOD NOW IS COMPLETELY REVERSED.
ALL MODELS NOW SHOW THE CURRENT UPPER RIDGE BUILDING OVER THE
FORECAST AREA TODAY AND EVEN INTO THIS EVENING. A LOT OF THIS HAS TO
DO WITH THE WESTERN TROUGH...WHICH IS SPLITTING APART EARLIER AND
THE NORTHERN PORTION ONLY ENDS UP REACHING NORTHWEST MINNESOTA BY
12Z TUESDAY. THE CHANGE SYNOPTICALLY HAS A BIG IMPACT ON THE
FORECAST. FIRST...NOW THAT THE AREA IS UNDERNEATH BUILDING HEIGHTS
AT 500MB INDUCING SUBSIDENCE...A DRIER FORECAST IS ON TAP. HAVE
REMOVED ALL PRECIPITATION CHANCES FOR TODAY AND LOWERED THEM DOWN TO
AT MOST 20 FOR THIS EVENING. THE 02.00Z GFS IS BASICALLY THE ONLY
MODEL THAT SHOWS PRECIPITATION TODAY...WHICH IS A RESULT OF DRIZZLE
BELOW A CAP. THIS SEEMS VERY SUSPECT AND THE GFS HAS BEEN KNOWN TO
OVERDO THESE DRIZZLE SCENARIOS AS SEEN BACK DURING THE UNPRECEDENTED
WARM SPELL IN MARCH. RUC/NAM SOUNDINGS LOOK MORE REPRESENTATIVE.
THERE STILL ARE INDICATIONS FOR PRECIPITATION AFTER 06Z TONIGHT...
ESPECIALLY NORTH OF I-90 WHERE ISENTROPIC LIFT SEEN ON THE 305K
SURFACE CAN INITIATE CONVECTION. NOTE...THOUGH...THE 02.00Z GEM AND
01.12Z ECMWF INITIATE THIS CONVECTION EVEN FARTHER NORTH OVER
NORTHERN WISCONSIN. SINCE THE 02.00Z ECMWF LOOKS MORE LIKE THE
NAM/GFS VERSUS ITS PREVIOUS RUN...HAVE LEFT THE PREVIOUS FORECAST
CHANCES ALONE AFTER 06Z. IF CONVECTION GOES TONIGHT...1-6 KM SHEAR
IS MOSTLY LESS THAN 15 KTS. THEREFORE...ANTICIPATING IT TO BE
DISORGANIZED AND NOT PRESENT MUCH OF A SEVERE THREAT. TEMPERATURES
ARE ANOTHER PROBLEM. HUDSON BAY HIGH PRESSURE LOOKS TO REMAIN
ANCHORED NOW TODAY...CAUSED IN PART BY THE BUILDING UPPER
RIDGING...WHICH HELPS TO MAINTAIN A FEED OF LOWER LEVEL COLD AIR SUB
850MB. FOR THE MOST PART EXPECTING HIGHS TODAY SIMILAR TO THOSE OF
YESTERDAY...THOUGH COLD ADVECTION OCCURRING AT 925MB TOWARDS CENTRAL
WISCONSIN COULD RESULT IN HIGHS A FEW DEGREES COLDER THERE. WITH A
SLOWER PROGRESSION OF THE UPPER RIDGE...AS WELL WITH AN INVERTED
SURFACE TROUGH MOVING WEST TO EAST ACROSS MINNESOTA...HAVE RAISED
LOWS UP DRAMATICALLY WEST OF THE MISSISSIPPI RIVER.
TUESDAY AND TUESDAY NIGHT...THE CHANGES KEEP COMING. MAJORITY OF THE
ENERGY WITH THE NORTHERN PORTION OF THE WESTERN TROUGH LOOKS TO LIFT
INTO NORTHEAST ONTARIO. HOWEVER...A SHORTWAVE EXTENDING
SOUTHWESTWARD IS PROGGED TO MOVE INTO NORTHERN WISCONSIN BY 00Z
WEDNESDAY...THEN DROP SOUTHEAST THROUGH THE AREA TUESDAY NIGHT. THIS
SHORTWAVE IS IMPORTANT AS THERE APPEARS TO BE AN AREA OF LOW TO
MID-LEVEL STRATUS AHEAD OF IT. ONCE THE SHORTWAVE PASSES THEN SKIES
CAN CLEAR OUT. HAVE HAD TO INCREASE CLOUD COVER FOR TUESDAY TO
ACCOUNT FOR THE STRATUS...WHICH IN COMBINATION WITH LOW LEVEL COLD
ADVECTION HAS RESULTED IN LOWERING HIGHS FOR SOUTHEAST MINNESOTA
INTO NORTH CENTRAL WISCONSIN A FEW DEGREES. ON THE OTHER HAND...THE
SLOWER PROGRESSION NOTED IN THE TODAY/TONIGHT DISCUSSION WITH THE
INVERTED TROUGH WILL ALLOW FAR SOUTHWEST WISCONSIN TO WARM UP MORE.
WOULD NOT BE SURPRISED IF TEMPERATURES MAY TRY TO FALL IN THE WAKE
OF THAT INVERTED TROUGH. REGARDING PRECIPITATION CHANCES ON
TUESDAY...FORCING IS VERY WEAK GIVEN LIMITED 500MB HEIGHT FALLS AND
FRONTOGENESIS BEHIND THE PASSING INVERTED TROUGH WEAKENING. IN
FACT...THE 02.00Z NAM/CANADIAN BOTH SUGGEST DRY. THEREFORE...CHANCES
ON TUESDAY ARE ONLY 20 PERCENT...AND CONFINED TO THE MORNING. LOWS
TUESDAY NIGHT ARE KIND OF TRICKY. THE 02.00Z NAM SUGGESTS THE LOW TO
MID LEVEL STRATUS REALLY DOES NOT CLEAR OUT...PARTICULARLY ALONG AND
SOUTH OF I-90. HOWEVER..THE 02.00Z GFS/CANADIAN/ECMWF ARE ALL
CLEARING SKIES OUT. HAVE CONSIDERED THE NAM AN OUTLIER FOR NOW AND
HAVE KEPT THE PREVIOUS FORECAST AND MAJORITY CONSENSUS OF CLEARING
SKIES. ANOTHER PROBLEM IS THAT THE EAST WINDS LOOK A LITTLE STRONGER
BECAUSE OF THE HIGH PRESSURE AREA BUILDING IN ONLY REACHING NORTHERN
MINNESOTA. IN THE END...KEPT LOWS PRETTY CLOSE TO THE PREVIOUS
FORECAST. LOOKS LIKE POTENTIAL EXISTS FOR FREEZE CONDITIONS NORTH OF
I-94. NO FROST ANTICIPATED...THOUGH...GIVEN DEWPOINTS EXPECTED TO
FALL INTO THE 20S AND WINDS STAYING UP.
WEDNESDAY AND WEDNESDAY NIGHT...A COUPLE OF BATTLING FEATURES ARE
FORECAST DURING THIS PERIOD. THE SOUTHERN END OF THE CURRENT WESTERN
TROUGH IS PROGGED TO CLOSE OFF INTO AN UPPER LOW...THEN LIFT THROUGH
KANSAS AND MISSOURI DURING THIS PERIOD. MEANWHILE...WE HAVE THAT
HIGH PRESSURE AREA BUILDING IN FROM NORTHWEST MINNESOTA...WHICH ENDS
UP CONSOLIDATING WITH A CANADIAN HIGH DROPPING DOWN INTO NORTHERN
ONTARIO. DRY AIR ASSOCIATED WITH THIS SURFACE HIGH PLUS UPPER
RIDGING NORTH AND NORTHEAST OF THE UPPER LOW SHOULD BE SUFFICIENT TO
HOLD OFF ANY PRECIPITATION FROM COMING INTO THE FORECAST AREA. COULD
SEE A FEW MID/HIGH CLOUDS TRY TO APPROACH NORTHEAST IOWA...BUT
ANTICIPATING MOST CLOUDS TO STAY SOUTH OF THE AREA TOO. WITH PLENTY
OF SUN AND 850MB TEMPS OF 2-4C...SHOULD SEE TEMPERATURES CLIMB INTO
THE LOW 60S. BETTER 925-850MB COOLING COMES IN WEDNESDAY NIGHT ON
EASTERLY WINDS...LIKELY WITH THAT CANADIAN HIGH COMING DOWN. A
SUSTAINED 5 TO 10 MPH WIND LOOKS LIKELY WEDNESDAY NIGHT...WHICH
SHOULD HELP TEMPERATURES FROM PLUMMETING TOO MUCH. STILL...READINGS
IN THE 30S ARE EXPECTED...COOLEST IN CENTRAL WISCONSIN CLOSER TO THE
COLD ADVECTION.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
330 AM CDT MON APR 2 2012
FOCUS OF THE LONG TERM FORECAST IS ON DEEP TROUGHING THAT IS ALONG
THE WEST COAST THURSDAY MORNING. UPPER RIDGING DOWNSTREAM OF THE
TROUGH SHOULD STAY NEAR OR OVER THE FORECAST AREA THROUGH FRIDAY
EVENING...MAINTAINING DRY CONDITIONS. THURSDAY INTO THURSDAY NIGHT
WILL LIKELY BE THE COOLEST PERIOD AS THE CANADIAN HIGH SLIDES DOWN
INTO EASTERN WISCONSIN ON THE EAST SIDE OF THE UPPER RIDGE. IF THERE
IS GOING TO BE A WIDESPREAD FREEZE...THINKING THURSDAY NIGHT WILL BE
THE BEST SHOT. WISCONSIN AREAS LOOK MOST SUSCEPTIBLE BEING CLOSER TO
THE SURFACE HIGH. WARMING THEN OCCURS FOR FRIDAY INTO SATURDAY AS
THE SURFACE HIGH DEPARTS OFF TO THE EAST. REGARDING THE UPPER
TROUGH...02.00Z ECMWF/CANADIAN/GFS AND GFS ENSEMBLES ARE ALL IN
FAIRLY GOOD AGREEMENT EJECTING IT OUT INTO THE NORTHERN PLAINS ON
SATURDAY. THE MODELS THEN BEGIN TO DIFFER ON SPEED FROM THERE...
RESULTING IN LOWERED CONFIDENCE. IN ANY EVENT...IT APPEARS THE
TROUGH HAS SLOWED DOWN ENOUGH THAT ANY FORCING FOR PRECIPITATION
WILL STAY WEST OF THE FORECAST AREA FRIDAY NIGHT. MODEL CONSENSUS
SUGGESTS THAT A WARM CONVEYOR BELT AHEAD OF THE NORTHERN PLAINS
TROUGH WILL ENTER THE AREA SATURDAY. MEAGER INSTABILITY EXISTS...
JUST ENOUGH TO WARRANT A CHANCE OF THUNDERSTORMS. AFTER
SATURDAY...STAYED WITH THE MODEL CONSENSUS IDEA WHICH WOULD BE FOR A
DRYING TREND. THIS IS DUE TO THE COLD FRONT ASSOCIATED WITH THE
TROUGH MOVING THROUGH THE FORECAST AREA. AGAIN...LOW CONFIDENCE
HERE.
&&
.AVIATION...THROUGH 18Z TUESDAY
1233 AM CDT MON APR 2 2012
MAIN FORECAST CHALLENGE IS ON CEILING HEIGHTS THROUGH THE TAF
PERIOD AND CONVECTIVE POTENTIAL TONIGHT. A NARROW BAND OF VFR
CLOUDS WAS PUSHING THROUGH THE KLSE TAF SITE AND SHOULD PUSH OUT
BY EARLY AFTERNOON. VFR CONDITIONS THEN EXPECTED THROUGH MUCH OF
THE NIGHT TONIGHT. AN AREA OF LOW PRESSURE WILL MOVE INTO NORTHERN
IOWA TONIGHT. MOISTURE TRANSPORT FOCUSES INTO NORTHERN MINNESOTA
THIS EVENING AND THEN NORTHERN WISCONSIN OVERNIGHT AHEAD OF THE
LOW. EXPECT CONVECTION TO DEVELOP IN THESE AREAS...BUT AT THIS
POINT LOOKS LIKE IT SHOULD REMAIN NORTH OF THE TAF SITES. DID ADD
MENTION OF VCSH FROM 10Z-15Z DUE TO THE UNCERTAINTY. SURFACE
BOUNDARY LOOKS TO MOVE THROUGH THE TAF SITES 11-12Z ACCOMPANIED
BY LOWER MVFR CEILINGS...WHICH WILL PERSIST THROUGH 18Z TUESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
330 AM CDT MON APR 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION...RABERDING