Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/21/12
AREA FORECAST DISCUSSION
NWS DENVER CO
1207 PM MDT SAT MAY 19 2012
.SHORT TERM...THE UPPER TROUGH IS RIGHT OVER THE CWA AT THIS
TIME...WITH THE BEST CONVECTION OVER THE FOOTHILLS AND IMMEDIATE
PLAINS. WITH THE AMOUNT OF CLOUD COVER EXPECTED...WILL LOWER HIGH
TEMPERATURES A BIT. WILL MAKE MINOR ADJUSTMENTS TO POPS WITH REAL
CONDITIONS IN MIND.
.AVIATION...WILL HANG ON TO PRECIPITATION AND LOWER CEILINGS A BIT
LONGER THIS AFTERNOON WITH CURRENT SITUATION IN MIND. WILL GET
BACK TO NORMAL DIURNAL WIND PATTERNS AROUND 06Z TONIGHT. CEILINGS
WILL GET ABOVE 5000 AGL BETWEEN 03Z AND 04Z THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 353 AM MDT SAT MAY 19 2012/
SHORT TERM...WATER VAPOR IMAGERY SHOWING UPPER LOW NOW MOVING
ACROSS WESTERN COLORADO WITH SCATTERED SHOWERS INCREASING ACROSS
THE NORTHERN MOUNTAINS ATTM. RUC QG ANALYSIS SHOWING WEAK TO MODERATE
ASCENT NOW INTO THE MOUNTAINS AND THIS WILL SPREAD OVER INTO THE
NORTHEAST PLAINS THIS MORNING. MEANWHILE...COLD FRONT HAS MOVED
THROUGH ALL OF NORTHEAST COLORADO WITH SHALLOW N-NE UPSLOPE FLOW
DEVELOPING OVER THE PAST FEW HOURS. SURFACE DEWPOINTS HAVE BEEN
RISING INTO THE MID 40S AND WE SHOULD START SEEING SOME STRATUS
DEVELOPING BETWEEN 09-12Z ACROSS THE FRONT RANGE GIVEN THE ASCENT
AND UPSLOPE DEVELOPING. SHORT RANGE MODELS STILL SHOWING A
MOISTENING AIRMASS THIS MORNING WITH SHOWERS SPREADING OUT OVER THE
PLAINS. CURRENT LIKELY POPS STILL SEEM REASONABLE BUT AMOUNTS
STILL LOOK TO BE ON THE LOW SIDE AS THE TROF WILL MOVING MOVING
RIGHT ALONG AND NOT A TON OF DEEP MOISTURE DEVELOPING WITH THIS
QUICK MOVING SYSTEM. TEMPERATURES MUCH COOLER TODAY WITH READINGS
ONLY IN THE 50S AND LOWER 60S OVER THE PLAINS. MAY SEE SOME LIGHT
SNOW ACCUMULATIONS IN THE MOUNTAINS AND WITH THE MORE SCATTERED
NATURE DON`T SEEM MUCH MORE THAN 2-4 INCHES IN THE HIGHER
MOUNTAINS. POSSIBLY A BIT MORE IN THE HEAVIER EMBEDDED CONVECTIVE
SNOW SHOWER. BOTH NAM/GFS SEEM A BIT HIGH WITH LIQUID AMOUNTS OVER
AN INCH IN MOUNTAINS AND HIGHER EAST SLOPES.
THE LOW WILL HAVE MOVED INTO WESTERN KANSAS BY LATE IN THE DAY
WITH SUBSIDENCE SPREADING OVER THE PLAINS THIS AFTERNOON. HENCE A
DECREASE IN SHOWER ACTIVITY AND ENDING IN MOST LOCALES DURING THE
EVENING HOURS. GRADUAL CLEARING OVERNIGHT ACROSS THE ENTIRE AREA.
LONG TERM...NORTHEAST COLORADO UNDER WEST-NORTHWESTERLY FLOW ALOFT
WITH THE SHORTWAVE TROUGH CONTINUING ITS EASTWARD PROGRESSION
ACROSS THE CENTRAL GREAT PLAINS DURING THE DAY SUNDAY. SHOULD SEE
A WARMER DAY WITH A 2C WARMING AT 700 MBS. MODELS ALSO SHOW
S-SELY SFC WINDS ON THE PLAINS STEADILY STRENGTHENING DURING THE
DAY WHICH AIDS IN TRANSPORTING INCREASINGLY HUMID AIR NORTHWARD
UP ALONG THE FRONT RANGE. STEEP LAPSE RATES DUE TO STG DAYTIME
HEATING AND THE ARRIVAL OF THIS MOISTURE SHOULD SUPPORT AT LEAST
ISOLATED T-STORM DEVELOP OVER AND NEAR THE FRONT RANGE DURING THE
AFTERNOON AND EVENING HOURS. STORMS MOVING OUT ACROSS THE PLAINS
MAY LINGER WELL INTO THE EVENING WITH THIS MOIST SELY INFLOW.
ON MONDAY...FCST AREA BENEATH A STG 500 MB HIGH PRESSURE RIDGE WITH
TEMPERATURES ALOFT CONTINUING TO WARM. A BRISK SOUTHERLY LOW-
LEVEL FLOW ON THE PLAINS WILL CONTINUE TO ADVECT MOISTURE UP INTO
THE AREA. BY AFTERNOON...MODELS SHOW AN 850-700 THETA-E RIDGE AXIS
ALIGNED FM COLORADO SPRINGS TO JULESBURG. ALONG THIS AXIS SFC
BASED CAPES PROGGED IN THE 1200-2000 KG/J RANGE BY LATE IN THE
DAY. HOWEVER STG WARMING ALOFT AND WEAK CIN POSSIBLY ENOUGH TO
SUPPRESS CONVECTION. FOR NOW WILL LEAVE OUT MENTION OF T-STORMS ON
THE PLAINS...BUT CAN/T RULE THEM OUT ENTIRELY. WHEREAS WILL
MENTION AT LEAST A SLIGHT CHANCE OF T-STORMS OVER AND NEAR THE
FRONT RANGE FOR LATE IN THE DAY. GOING FOR TEMPERATURES ON MONDAY
IN THE LOWER-MID 80S AT LOWER ELEVATIONS WITH UPPER 50S- 70S IN
THE HIGH COUNTRY.
BY TUESDAY...UPPER RIDGE MOVES EAST OF THE STATE PLACING THE AREA
UNDER INCREASING SOUTHWESTERLY FLOW ALOFT. A DRIER MID-LEVEL WITH
SUBSIDENCE ON THE SOUTH SIDE OF AN APPROACHING UPPER AIR TROUGH
SHOULD RESULT IN PLENTY OF SUNSHINE DURING THE MORNING HOURS.
COMBINATION OF UNSEASONABLY WARM TEMPERATURES...LOW HUMIDITY AND
AND STEEP LAPSE RATES WILL LIKELY INCREASE THE WILDLAND FIRE
DANGER IN MANY AREAS. NOT UNTIL LATE IN THE DAY WHEN THE UPPER
TROUGH NEARS WILL SEE CONVECTION...MOST OF WHICH SHOULD BE
CONFINED TO THE HIGHER TERRAIN NORTH OF I-70. SHOULD SEE ANOTHER
DAY OF VERY WARM TEMPERATURES WITH HIGHS PUSHING THE 90 DEG MARK
ON THE PLAINS.
BY WEDNESDAY TEMPERATURES TURN COOLER WITH PASSAGE OF THE UPPER
TROUGH AND PASSAGE OF A COLD FRONT DURING THE DAY. SHOULD SEE THE
CHANCE FOR SHOWERS AND T-STORMS ALSO INCREASE. THE UPPER TROUGH
PASSES TO THE EAST OVERNIGHT RESULTING IN A SLIGHT MODERATION IN
TEMPERATURE AND A REDUCED CHANCE IN PRECIP. FOR LATER IN THE
WEEK...SHOULD SEE STEADY WARMING WITH THE RETURN OF RIDGING.
AVIATION...CEILINGS LOWERING BY DAYBREAK WITH MAINLY MVFR/ILS
APPROACHES THROUGH THIS MORNING WITH RAIN SHOWERS AND THEN
IMPROVING TRENDS DURING THE AFTERNOON. SURFACE WINDS SHOULD REMAIN
N-NE TODAY BEFORE SHIFTING SE-S BY LATER THIS EVENING AND A RETURN
TO DRAINAGE.
HYDROLOGY...RAINFALL AMOUNTS LOOK TO BE IN THE QUARTER TO HALF
INCH RANGE FOR TODAY WITH RAINFALL RATES GENERALLY A TENTH OF AN
INCH PER HOUR OR LESS WITH THE SHOWERS. ANY FLOODING POTENTIAL IN THE
BURN AREAS SEEM LOW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RJK/ENTREKIN
LONG TERM....BAKER
AVIATION...RJK/ENTREKIN
AREA FORECAST DISCUSSION
NWS DENVER CO
353 AM MDT SAT MAY 19 2012
.SHORT TERM...WATER VAPOR IMAGERY SHOWING UPPER LOW NOW MOVING
ACROSS WESTERN COLORADO WITH SCATTERED SHOWERS INCREASING ACROSS
THE NORTHERN MOUNTAINS ATTM. RUC QG ANALYSIS SHOWING WEAK TO MODERATE
ASCENT NOW INTO THE MOUNTAINS AND THIS WILL SPREAD OVER INTO THE
NORTHEAST PLAINS THIS MORNING. MEANWHILE...COLD FRONT HAS MOVED
THROUGH ALL OF NORTHEAST COLORADO WITH SHALLOW N-NE UPSLOPE FLOW
DEVELOPING OVER THE PAST FEW HOURS. SURFACE DEWPOINTS HAVE BEEN
RISING INTO THE MID 40S AND WE SHOULD START SEEING SOME STRATUS
DEVELOPING BETWEEN 09-12Z ACROSS THE FRONT RANGE GIVEN THE ASCENT
AND UPSLOPE DEVELOPING. SHORT RANGE MODELS STILL SHOWING A
MOISTENING AIRMASS THIS MORNING WITH SHOWERS SPREADING OUT OVER THE
PLAINS. CURRENT LIKELY POPS STILL SEEM REASONABLE BUT AMOUNTS
STILL LOOK TO BE ON THE LOW SIDE AS THE TROF WILL MOVING MOVING
RIGHT ALONG AND NOT A TON OF DEEP MOISTURE DEVELOPING WITH THIS
QUICK MOVING SYSTEM. TEMPERATURES MUCH COOLER TODAY WITH READINGS
ONLY IN THE 50S AND LOWER 60S OVER THE PLAINS. MAY SEE SOME LIGHT
SNOW ACCUMULATIONS IN THE MOUNTAINS AND WITH THE MORE SCATTERED
NATURE DON`T SEEM MUCH MORE THAN 2-4 INCHES IN THE HIGHER
MOUNTAINS. POSSIBLY A BIT MORE IN THE HEAVIER EMBEDDED CONVECTIVE
SNOW SHOWER. BOTH NAM/GFS SEEM A BIT HIGH WITH LIQUID AMOUNTS OVER
AN INCH IN MOUNTAINS AND HIGHER EAST SLOPES.
THE LOW WILL HAVE MOVED INTO WESTERN KANSAS BY LATE IN THE DAY
WITH SUBSIDENCE SPREADING OVER THE PLAINS THIS AFTERNOON. HENCE A
DECREASE IN SHOWER ACTIVITY AND ENDING IN MOST LOCALES DURING THE
EVENING HOURS. GRADUAL CLEARING OVERNIGHT ACROSS THE ENTIRE AREA.
.LONG TERM...NORTHEAST COLORADO UNDER WEST-NORTHWESTERLY FLOW ALOFT
WITH THE SHORTWAVE TROUGH CONTINUING ITS EASTWARD PROGRESSION
ACROSS THE CENTRAL GREAT PLAINS DURING THE DAY SUNDAY. SHOULD SEE
A WARMER DAY WITH A 2C WARMING AT 700 MBS. MODELS ALSO SHOW
S-SELY SFC WINDS ON THE PLAINS STEADILY STRENGTHENING DURING THE
DAY WHICH AIDS IN TRANSPORTING INCREASINGLY HUMID AIR NORTHWARD
UP ALONG THE FRONT RANGE. STEEP LAPSE RATES DUE TO STG DAYTIME
HEATING AND THE ARRIVAL OF THIS MOISTURE SHOULD SUPPORT AT LEAST
ISOLATED T-STORM DEVELOP OVER AND NEAR THE FRONT RANGE DURING THE
AFTERNOON AND EVENING HOURS. STORMS MOVING OUT ACROSS THE PLAINS
MAY LINGER WELL INTO THE EVENING WITH THIS MOIST SELY INFLOW.
ON MONDAY...FCST AREA BENEATH A STG 500 MB HIGH PRESSURE RIDGE WITH
TEMPERATURES ALOFT CONTINUING TO WARM. A BRISK SOUTHERLY LOW-
LEVEL FLOW ON THE PLAINS WILL CONTINUE TO ADVECT MOISTURE UP INTO
THE AREA. BY AFTERNOON...MODELS SHOW AN 850-700 THETA-E RIDGE AXIS
ALIGNED FM COLORADO SPRINGS TO JULESBURG. ALONG THIS AXIS SFC
BASED CAPES PROGGED IN THE 1200-2000 KG/J RANGE BY LATE IN THE
DAY. HOWEVER STG WARMING ALOFT AND WEAK CIN POSSIBLY ENOUGH TO
SUPPRESS CONVECTION. FOR NOW WILL LEAVE OUT MENTION OF T-STORMS ON
THE PLAINS...BUT CAN/T RULE THEM OUT ENTIRELY. WHEREAS WILL
MENTION AT LEAST A SLIGHT CHANCE OF T-STORMS OVER AND NEAR THE
FRONT RANGE FOR LATE IN THE DAY. GOING FOR TEMPERATURES ON MONDAY
IN THE LOWER-MID 80S AT LOWER ELEVATIONS WITH UPPER 50S- 70S IN
THE HIGH COUNTRY.
BY TUESDAY...UPPER RIDGE MOVES EAST OF THE STATE PLACING THE AREA
UNDER INCREASING SOUTHWESTERLY FLOW ALOFT. A DRIER MID-LEVEL WITH
SUBSIDENCE ON THE SOUTH SIDE OF AN APPROACHING UPPER AIR TROUGH
SHOULD RESULT IN PLENTY OF SUNSHINE DURING THE MORNING HOURS.
COMBINATION OF UNSEASONABLY WARM TEMPERATURES...LOW HUMIDITY AND
AND STEEP LAPSE RATES WILL LIKELY INCREASE THE WILDLAND FIRE
DANGER IN MANY AREAS. NOT UNTIL LATE IN THE DAY WHEN THE UPPER
TROUGH NEARS WILL SEE CONVECTION...MOST OF WHICH SHOULD BE
CONFINED TO THE HIGHER TERRAIN NORTH OF I-70. SHOULD SEE ANOTHER
DAY OF VERY WARM TEMPERATURES WITH HIGHS PUSHING THE 90 DEG MARK
ON THE PLAINS.
BY WEDNESDAY TEMPERATURES TURN COOLER WITH PASSAGE OF THE UPPER
TROUGH AND PASSAGE OF A COLD FRONT DURING THE DAY. SHOULD SEE THE
CHANCE FOR SHOWERS AND T-STORMS ALSO INCREASE. THE UPPER TROUGH
PASSES TO THE EAST OVERNIGHT RESULTING IN A SLIGHT MODERATION IN
TEMPERATURE AND A REDUCED CHANCE IN PRECIP. FOR LATER IN THE
WEEK...SHOULD SEE STEADY WARMING WITH THE RETURN OF RIDGING.
&&
.AVIATION...CEILINGS LOWERING BY DAYBREAK WITH MAINLY MVFR/ILS
APPROACHES THROUGH THIS MORNING WITH RAIN SHOWERS AND THEN
IMPROVING TRENDS DURING THE AFTERNOON. SURFACE WINDS SHOULD REMAIN
N-NE TODAY BEFORE SHIFTING SE-S BY LATER THIS EVENING AND A RETURN
TO DRAINAGE.
&&
.HYDROLOGY...RAINFALL AMOUNTS LOOK TO BE IN THE QUARTER TO HALF
INCH RANGE FOR TODAY WITH RAINFALL RATES GENERALLY A TENTH OF AN
INCH PER HOUR OR LESS WITH THE SHOWERS. ANY FLOODING POTENTIAL IN THE
BURN AREAS SEEM LOW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....BAKER
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1048 PM EDT SUN MAY 20 2012
.SYNOPSIS...
HIGH PRESSURE MOVES SLOWLY OFF THE NORTHEAST COAST TONIGHT THEN
DEPARTS MONDAY. MEANWHILE A WAVE OF LOW PRESSURE WILL MOVE TOWARD
THE AREA TONIGHT AND REMAIN INTO MONDAY BEFORE MOVING TO THE
NORTHEAST MONDAY NIGHT. A SERIES OF WEAK LOW PRESSURE SYSTEMS
WILL CREATE UNSETTLED CONDITIONS ACROSS THE TRI-STATE INTO
WEDNESDAY. A COLD FRONT WILL PUSH INTO THE REGION LATE
WEDNESDAY...THEN STALL OUT NEARBY INTO FRIDAY. ANOTHER COLD FRONT
APPROACHES FROM THE NORTHWEST FRIDAY NIGHT...THEN MOVES ACROSS THE
AREA SATURDAY AND SATURDAY EVENING. HIGH PRESSURE THEN BUILDS DOWN
FROM CANADA INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPDATES INCLUDE FURTHER ADJUSTMENTS TO MAINLY SKY/POP/TEMP AND
DEWPOINT GRIDS. NOW LOOKS CHANCES OF RAINFALL WILL BE LATE AT
NIGHT. LIKELIHOOD OF SHOWERS PROBABLY DOESN`T ARRIVE UNTIL AROUND
DAYBREAK FOR THE SOUTHERNMOST PORTIONS OF THE CWA...BUT ISOLATED TO
SCATTERED SHOWERS ARE EXPECTED TO BE IN THE VICINITY AFTER
MIDNIGHT. MOST RECENT RUNS OF THE HRRR AND RUC MODELS GENERALLY
AGREE WITH THIS TREND.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
TROPICAL STORM ALBERTO DOES NOT HAVE A DIRECT IMPACT TO THE LOCAL
AREA BASED ON THE LATEST MODEL GUIDANCE AND TRACK FORECAST FROM THE
NATIONAL HURRICANE CENTER. PLEASE REFER TO NHC FOR THE LATEST
ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING TROPICAL
STORM ALBERTO.
SYNOPTIC FEATURES REMAIN WEAK THROUGH MONDAY NIGHT AS BROAD UPPER
TROUGH REMAINS ALONG THE EASTERN PORTION OF THE COUNTRY. WAVES OF
LOW PRESSURE MOVE ALONG THE COAST THROUGH THE PERIOD. CURRENT
THINKING IS THE BEST CHANCE OF PRECIPITATION IS DURING THE DAY
MONDAY AND INTO THE EARLY EVENING WITH THE BEST SYNOPTIC
FORCING...ALTHOUGH WEAK. PRECIPITABLE WATER VALUES INCREASE TO
AROUND 1.5 INCHES DURING THIS PERIOD AND IS ABOUT 170 PERCENT OF
NORMAL. SO WENT WITH MODERATE SHOWERS. MARINE LAYER WILL BE IN
PLACE MONDAY AND MONDAY NIGHT WITH THE AREA STABLE SO WILL NOT
MENTION THUNDER.
WITH CLOUDS...EAST FLOW AND RAIN...LEANED TOWARD THE LOWER NAM
GUIDANCE FOR HIGHS MONDAY...AND USED A BLEND FOR MONDAY NIGHTS
LOWS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE MODELS ARE IN MUCH BETTER AGREEMENT THAN YESTERDAY FOR THE MID
TO LATE WEEK TIME FRAME. USED A BLEND OF THE NAM/SREF/ECMWF/GFS FOR
THE FORECAST TUESDAY-WEDNESDAY AND THE GFS/ECMWF/CMC-GLOBAL
WEDNESDAY NIGHT-SUNDAY.
T.S. ALBERTO IS EXPECTED TO HAVE NO DIRECT IMPACT ON THE
REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA
BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE
CENTER FOR THE LATEST INFORMATION ON ALBERTO.
A SERIES OF WEAK SHORTWAVES CROSS THE AREA TUESDAY-THURSDAY NIGHT.
DURING THIS TIME FRAME...WILL JUST BE IN A MOIST/RELATIVELY HUMID
ENVIRONMENT...WITH AN ONSHORE FLOW PROMOTING A MARINE LAYER AND
CLOUD COVER NEAR THE COAST...WITH LESS OF AN INFLUENCE/CLOUDS OVER
THE INTERIOR. WITH MORE INSTABILITY EXPECTED INLAND...HAVE GONE WITH
CHANCE POPS ACROSS THE INTERIOR AND SLIGHT CHANCE POPS OVER COASTAL
AREAS DURING THE DAY AND SLIGHT CHANCE POPS AT NIGHT. HAVE A CHANCE
OF THUNDER DURING THE DAY TUESDAY/WEDNESDAY ACROSS INTERIOR ZONES AS
WELL WITH SOME MARGINAL INSTABILITY EXPECTED. WITH A RATHER DIFFUSE
FRONT DISSIPATING OVER THE REGION FRIDAY...ONLY HAVE SLIGHT CHANCE
POPS OVER THE INTERIOR THEN.
WITH PERSISTENT ONSHORE FLOW EXPECTED INTO WEDNESDAY...HAVE FOG IN
EARLY TUESDAY MORNING...AND AGAIN FROM LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING.
WITH A SHORTWAVE FORECAST TO PASS THROUGH FRIDAY NIGHT...HAVE SLIGHT
CHANCE POPS THROUGHOUT. WITH THE APPROACH/PASSAGE OF A COLD FRONT
SATURDAY...HAVE A CHANCE OF THUNDER THROUGHOUT...TAPERING TO A DRY
FORECAST BY SUNDAY AS RIDGING BEGINS TO BUILD IN.
FOR TEMPERATURES...USED A BLEND OF MAV/MET GUIDANCE/NAM 2-METER
TEMPERATURES AND MIXING DOWN FROM 950 HPA FOR HIGHS ON
TUESDAY...WITH VALUES FORECAST SLIGHTLY ABOVE NORMAL. FOR LOWS
TUESDAY NIGHT USED A BLEND OF BIAS CORRECTED MAV GUIDANCE WITH MET
GUIDANCE AND NAM 2-METER TEMPERATURES...WHICH YIELDED VALUES AROUND
5 DEGREES ABOVE NORMAL. FOR HIGHS WEDNESDAY USED A BLEND OF MIXING
DOWN FROM 925 HPA NEAR THE COAST...850 HPA INLAND...WITH NAM 2-METER
TEMPERATURES...AND MEX GUIDANCE. THIS YIELDS VALUES 5 TO 10 DEGREES
ABOVE NORMAL. FROM WEDNESDAY NIGHT-SUNDAY BLENDED 18Z HPC GUIDANCE
WITH A MEX/MEX ENSEMBLE MEAN BLEND. THIS YIELDED ABOVE NORMAL
TEMPERATURES THROUGH THIS TIME FRAME.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE REMAINS JUST OFF THE NEW ENGLAND COAST AS WEAK LOW
PRESSURE DRIFTS NORTHWARD TONIGHT AND MONDAY.
1000-2000 FT CEILINGS HAVE ARRIVED OVER SOME OF THE SOUTHERN
TERMINALS. EXPECTING REST THE OF THE TERMINALS TO HAVE SIMILAR
CEILINGS BY 05Z-08Z...WITH IFR CEILINGS FOR AT LEAST KJFK AND KISP
BY THIS PERIOD. FORECAST TIMING OF OTHER TERMINALS DROPPING TO IFR
CONDITIONS MAY BE COUPLE HOURS TOO SLOW. AS FOR LIKELIHOOD OF
SHOWERS...LOOKS TO BE TOWARDS DAYBREAK FOR THE CITY/SOUTHERN
TERMINALS...BUT KJFK MAY PICK UP BRIEF MOMENTS OF DRIZZLE
BEFOREHAND.
.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
.MONDAY NIGHT...MVFR OR IFR IN RAIN.
.TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM
WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT.
.THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN
SHOWERS ON FRIDAY.
&&
.MARINE...
FORECAST APPEARS ON TRACK. A EAST TO SOUTHEAST SWELL WILL
CONTINUE ACROSS THE OCEAN WATERS THROUGH AT LEAST MONDAY NIGHT AS
LOW PRESSURE ALONG THE MID ATLANTIC COAST BEGINS TO MOVE TO THE
NORTHEAST MONDAY NIGHT. WINDS ACROSS THE FORECAST WATERS WILL
REMAIN BELOW SMALL CRAFT LEVELS THROUGH THE PERIOD WITH A WEAK
PRESSURE GRADIENT. THE SMALL CRAFT FOR HAZARDOUS SEAS REMAINS
EXTENDED THROUGH MONDAY NIGHT AS SEAS WILL REMAIN AROUND 5 FT
THROUGH THE TIME FRAME.
A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER
THE COASTAL OCEAN WATERS FROM TUESDAY INTO WEDNESDAY...BUT WITH THE
WINDS VEERING FROM SE ON TUESDAY TO S-SW BY WEDNESDAY...EXPECT SEAS
TO BEGIN TO DIMINISH STARTING TUESDAY NIGHT. OTHERWISE...WITH A
RELATIVELY LIGHT PRESSURE GRADIENT FORECAST ACROSS THE AREA EXPECT
CONDITIONS TO REMAIN WELL BELOW SCA THRESHOLDS FROM TUESDAY INTO
FRIDAY.
&&
.HYDROLOGY...
LIGHT PRECIPITATION MOVES TOWARDS DAYBREAK AND THEN CONTINUES
THROUGH AT LEAST MONDAY NIGHT. THE BULK OF THE PRECIPITATION WILL
LIKELY OCCUR DURING THE DAY MONDAY. TOTAL PRECIPITATION TONIGHT
THROUGH MONDAY NIGHT WILL RANGE FROM AROUND A THIRD OF AN INCH FAR
WESTERN SECTIONS TO AROUND TWO THIRDS OF AN INCH ACROSS MUCH OF
THE CWA.
THERE IS SOME POTENTIAL FOR SIGNIFICANT RAINFALL INTO THE MIDDLE OF
NEXT WEEK. THERE IS STILL QUITE A BIT OF UNCERTAINTY AS TO EXACTLY
HOW MUCH OF THIS TIME FRAME WILL ACTUALLY HAVE PRECIPITATION
FALL...AND HOW INTENSE IT WILL BE. IT IS APPEARING MORE LIKELY
THOUGH THAT IF THERE IS ANY HEAVY RAINFALL...IT MOST LIKELY WILL BE
FROM NYC ON N AND W. HOWEVER WITH PRECIPITABLE WATERS FORECAST TO BE
150-175% ABOVE NORMAL IN THIS TIME FRAME...AND THE POTENTIAL FOR
CONVECTION...AREAS OF LOCALLY HEAVY RAINFALL CANNOT BE RULED OUT ANY
WHERE ACROSS THE CWA.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT TUESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MALOIT/MET
NEAR TERM...JC/MALOIT/LN
SHORT TERM...MET
LONG TERM...MALOIT
AVIATION...JC
MARINE...MALOIT/MET
HYDROLOGY...MALOIT/MET
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1003 PM EDT SUN MAY 20 2012
.SYNOPSIS...
HIGH PRESSURE MOVES SLOWLY OFF THE NORTHEAST COAST TONIGHT THEN
DEPARTS MONDAY. MEANWHILE A WAVE OF LOW PRESSURE WILL MOVE TOWARD
THE AREA TONIGHT AND REMAIN INTO MONDAY BEFORE MOVING TO THE
NORTHEAST MONDAY NIGHT. A SERIES OF WEAK LOW PRESSURE SYSTEMS
WILL CREATE UNSETTLED CONDITIONS ACROSS THE TRI-STATE INTO
WEDNESDAY. A COLD FRONT WILL PUSH INTO THE REGION LATE
WEDNESDAY...THEN STALL OUT NEARBY INTO FRIDAY. ANOTHER COLD FRONT
APPROACHES FROM THE NORTHWEST FRIDAY NIGHT...THEN MOVES ACROSS THE
AREA SATURDAY AND SATURDAY EVENING. HIGH PRESSURE THEN BUILDS DOWN
FROM CANADA INTO SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
UPDATES INCLUDE FURTHER ADJUSTMENTS TO MAINLY SKY/POP/TEMP AND
DEWPOINT GRIDS. NOW LOOKS CHANCES OF RAINFALL WILL BE LATE AT
NIGHT. LIKELIHOOD OF SHOWERS PROBABLY DOESN`T ARRIVE UNTIL AROUND
DAYBREAK FOR THE SOUTHERNMOST PORTIONS OF THE CWA...BUT ISOLATED TO
SCATTERED SHOWERS ARE EXPECTED TO BE IN THE VICINITY AFTER
MIDNIGHT. MOST RECENT RUNS OF THE HRRR AND RUC MODELS GENERALLY
AGREE WITH THIS TREND.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
TROPICAL STORM ALBERTO DOES NOT HAVE A DIRECT IMPACT TO THE LOCAL
AREA BASED ON THE LATEST MODEL GUIDANCE AND TRACK FORECAST FROM THE
NATIONAL HURRICANE CENTER. PLEASE REFER TO NHC FOR THE LATEST
ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING TROPICAL
STORM ALBERTO.
SYNOPTIC FEATURES REMAIN WEAK THROUGH MONDAY NIGHT AS BROAD UPPER
TROUGH REMAINS ALONG THE EASTERN PORTION OF THE COUNTRY. WAVES OF
LOW PRESSURE MOVE ALONG THE COAST THROUGH THE PERIOD. CURRENT
THINKING IS THE BEST CHANCE OF PRECIPITATION IS DURING THE DAY
MONDAY AND INTO THE EARLY EVENING WITH THE BEST SYNOPTIC
FORCING...ALTHOUGH WEAK. PRECIPITABLE WATER VALUES INCREASE TO
AROUND 1.5 INCHES DURING THIS PERIOD AND IS ABOUT 170 PERCENT OF
NORMAL. SO WENT WITH MODERATE SHOWERS. MARINE LAYER WILL BE IN
PLACE MONDAY AND MONDAY NIGHT WITH THE AREA STABLE SO WILL NOT
MENTION THUNDER.
WITH CLOUDS...EAST FLOW AND RAIN...LEANED TOWARD THE LOWER NAM
GUIDANCE FOR HIGHS MONDAY...AND USED A BLEND FOR MONDAY NIGHTS
LOWS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE MODELS ARE IN MUCH BETTER AGREEMENT THAN YESTERDAY FOR THE MID
TO LATE WEEK TIME FRAME. USED A BLEND OF THE NAM/SREF/ECMWF/GFS FOR
THE FORECAST TUESDAY-WEDNESDAY AND THE GFS/ECMWF/CMC-GLOBAL
WEDNESDAY NIGHT-SUNDAY.
T.S. ALBERTO IS EXPECTED TO HAVE NO DIRECT IMPACT ON THE
REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA
BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE
CENTER FOR THE LATEST INFORMATION ON ALBERTO.
A SERIES OF WEAK SHORTWAVES CROSS THE AREA TUESDAY-THURSDAY NIGHT.
DURING THIS TIME FRAME...WILL JUST BE IN A MOIST/RELATIVELY HUMID
ENVIRONMENT...WITH AN ONSHORE FLOW PROMOTING A MARINE LAYER AND
CLOUD COVER NEAR THE COAST...WITH LESS OF AN INFLUENCE/CLOUDS OVER
THE INTERIOR. WITH MORE INSTABILITY EXPECTED INLAND...HAVE GONE WITH
CHANCE POPS ACROSS THE INTERIOR AND SLIGHT CHANCE POPS OVER COASTAL
AREAS DURING THE DAY AND SLIGHT CHANCE POPS AT NIGHT. HAVE A CHANCE
OF THUNDER DURING THE DAY TUESDAY/WEDNESDAY ACROSS INTERIOR ZONES AS
WELL WITH SOME MARGINAL INSTABILITY EXPECTED. WITH A RATHER DIFFUSE
FRONT DISSIPATING OVER THE REGION FRIDAY...ONLY HAVE SLIGHT CHANCE
POPS OVER THE INTERIOR THEN.
WITH PERSISTENT ONSHORE FLOW EXPECTED INTO WEDNESDAY...HAVE FOG IN
EARLY TUESDAY MORNING...AND AGAIN FROM LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING.
WITH A SHORTWAVE FORECAST TO PASS THROUGH FRIDAY NIGHT...HAVE SLIGHT
CHANCE POPS THROUGHOUT. WITH THE APPROACH/PASSAGE OF A COLD FRONT
SATURDAY...HAVE A CHANCE OF THUNDER THROUGHOUT...TAPERING TO A DRY
FORECAST BY SUNDAY AS RIDGING BEGINS TO BUILD IN.
FOR TEMPERATURES...USED A BLEND OF MAV/MET GUIDANCE/NAM 2-METER
TEMPERATURES AND MIXING DOWN FROM 950 HPA FOR HIGHS ON
TUESDAY...WITH VALUES FORECAST SLIGHTLY ABOVE NORMAL. FOR LOWS
TUESDAY NIGHT USED A BLEND OF BIAS CORRECTED MAV GUIDANCE WITH MET
GUIDANCE AND NAM 2-METER TEMPERATURES...WHICH YIELDED VALUES AROUND
5 DEGREES ABOVE NORMAL. FOR HIGHS WEDNESDAY USED A BLEND OF MIXING
DOWN FROM 925 HPA NEAR THE COAST...850 HPA INLAND...WITH NAM 2-METER
TEMPERATURES...AND MEX GUIDANCE. THIS YIELDS VALUES 5 TO 10 DEGREES
ABOVE NORMAL. FROM WEDNESDAY NIGHT-SUNDAY BLENDED 18Z HPC GUIDANCE
WITH A MEX/MEX ENSEMBLE MEAN BLEND. THIS YIELDED ABOVE NORMAL
TEMPERATURES THROUGH THIS TIME FRAME.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE REMAINS JUST OFF THE NEW ENGLAND COAST AS WEAK LOW
PRESSURE DRIFTS NORTHWARD TONIGHT AND MONDAY.
BASED ON LATEST OBSERVED TRENDS...HAVE DELAYED ONSET OF MVFR/IFR
CEILINGS/VSBYS FOR LATE TONIGHT INTO MONDAY MORNING BY A COUPLE OF
HOURS...AND HAVE DELAYED ONSET OF SHOWERS BY EVEN MORE. ONSET IN
ALL CASES COULD BE OFF BY A COUPLE OF HOURS. KJFK WOULD STAND THE
BEST CHANCE OF SEEING CEILINGS LOWER TO 3000 FT OR LOWER BEFORE
WHAT IS IN THE FORECAST.
.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
.MONDAY NIGHT...MVFR OR IFR IN RAIN.
.TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM
WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT.
.THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN
SHOWERS ON FRIDAY.
&&
.MARINE...
FORECAST APPEARS ON TRACK. A EAST TO SOUTHEAST SWELL WILL
CONTINUE ACROSS THE OCEAN WATERS THROUGH AT LEAST MONDAY NIGHT AS
LOW PRESSURE ALONG THE MID ATLANTIC COAST BEGINS TO MOVE TO THE
NORTHEAST MONDAY NIGHT. WINDS ACROSS THE FORECAST WATERS WILL
REMAIN BELOW SMALL CRAFT LEVELS THROUGH THE PERIOD WITH A WEAK
PRESSURE GRADIENT. THE SMALL CRAFT FOR HAZARDOUS SEAS REMAINS
EXTENDED THROUGH MONDAY NIGHT AS SEAS WILL REMAIN AROUND 5 FT
THROUGH THE TIME FRAME.
A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER
THE COASTAL OCEAN WATERS FROM TUESDAY INTO WEDNESDAY...BUT WITH THE
WINDS VEERING FROM SE ON TUESDAY TO S-SW BY WEDNESDAY...EXPECT SEAS
TO BEGIN TO DIMINISH STARTING TUESDAY NIGHT. OTHERWISE...WITH A
RELATIVELY LIGHT PRESSURE GRADIENT FORECAST ACROSS THE AREA EXPECT
CONDITIONS TO REMAIN WELL BELOW SCA THRESHOLDS FROM TUESDAY INTO
FRIDAY.
&&
.HYDROLOGY...
LIGHT PRECIPITATION MOVES TOWARDS DAYBREAK AND THEN CONTINUES
THROUGH AT LEAST MONDAY NIGHT. THE BULK OF THE PRECIPITATION WILL
LIKELY OCCUR DURING THE DAY MONDAY. TOTAL PRECIPITATION TONIGHT
THROUGH MONDAY NIGHT WILL RANGE FROM AROUND A THIRD OF AN INCH FAR
WESTERN SECTIONS TO AROUND TWO THIRDS OF AN INCH ACROSS MUCH OF
THE CWA.
THERE IS SOME POTENTIAL FOR SIGNIFICANT RAINFALL INTO THE MIDDLE OF
NEXT WEEK. THERE IS STILL QUITE A BIT OF UNCERTAINTY AS TO EXACTLY
HOW MUCH OF THIS TIME FRAME WILL ACTUALLY HAVE PRECIPITATION
FALL...AND HOW INTENSE IT WILL BE. IT IS APPEARING MORE LIKELY
THOUGH THAT IF THERE IS ANY HEAVY RAINFALL...IT MOST LIKELY WILL BE
FROM NYC ON N AND W. HOWEVER WITH PRECIPITABLE WATERS FORECAST TO BE
150-175% ABOVE NORMAL IN THIS TIME FRAME...AND THE POTENTIAL FOR
CONVECTION...AREAS OF LOCALLY HEAVY RAINFALL CANNOT BE RULED OUT ANY
WHERE ACROSS THE CWA.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT TUESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MALOIT/MET
NEAR TERM...JC/MALOIT/LN
SHORT TERM...MET
LONG TERM...MALOIT
AVIATION...JC
MARINE...MALOIT/MET
HYDROLOGY...MALOIT/MET
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
955 PM EDT Sun May 20 2012
.SYNOPSIS..
At the surface, RAP analysis shows Tropical Storm Alberto
to our northeast off the GA coast and ridging to our west over
Louisiana. This is providing northeasterly flow and clear skies.
00Z TAE sounding shows a significantly drier air mass in place below
800 mb.
At the upper levels, 500 mb analysis shows a trough over Wisconsin
and a ridge extending over the mountain west. As this trough slides
eastward it will begin to lift Alberto to the northeast. As the
trough digs in over the east coast by Tuesday it will give us our
first chance at seeing some rain.
Tonight, with a drier air mass being advected in from the NE, we
are looking at seeing lows ranging from the mid 50s to low 60s,
mostly clear skies and light winds. After sunrise, temperatures
will rebound quickly and are expected to reach into the lower 90s.
&&
.AVIATION...
VFR conditions are expected through the period with light offshore
winds tonight increasing to 5 to 10 mph after sunrise.
&&
.MARINE...
Light northeast winds 5 to 10 kts for tonight with seas one to two
feet and smooth in protected waters.
&&
.FIRE WEATHER...
Low relative humidity values are expected again on Monday afternoon.
Updated ERC values of 35 across portions of N FL necessitated
issuance of a RFW for Mon aftn. A small increase in moisture is
expected for the remainder of the week with relative humidity values
slightly moister than critical levels.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 86 57 91 63 88 / 10 0 0 20 40
Panama City 87 65 87 70 87 / 10 0 0 20 30
Dothan 86 61 93 65 89 / 0 0 10 20 30
Albany 86 58 92 64 89 / 0 0 10 20 40
Valdosta 84 57 92 61 88 / 10 10 0 20 40
Cross City 86 55 88 62 87 / 10 0 0 10 30
Apalachicola 84 61 84 68 86 / 10 0 0 20 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...Red Flag Warning from 1 PM EDT /Noon CDT/ to 7 PM EDT /6 PM CDT/
Monday for Central Walton-Coastal Bay-Coastal Wakulla-
Inland Bay-Inland Wakulla-Inland Walton-Leon-South Walton-
Washington.
GM...None.
&&
$$
Harrigan/Walsh/Block
AREA FORECAST DISCUSSION
NWS MIAMI FL
147 PM EDT SAT MAY 19 2012
.AVIATION...
CONVECTION HAS STARTED ACROSS THE SOUTH FLORIDA PENINSULA. THE
MOST ACTIVE REGION IS ACROSS THE EASTERN HALF WITH ALL TERMINALS
ASSIGNED VCTS. FOR TERMINAL KAPF...ALSO ASSIGNED VCTS WITH
CONVECTION STARTING JUST INLAND OF THE TERMINAL. THERE IS THE
POTENTIAL FOR SOME STRONG TO SEVERE THUNDERSTORMS THIS AFTERNOON
WITH THE EAST COAST TERMINALS BEING THE MOST LIKELY TO BE AFFECTED
WITH PERIODS OF MVFR TO IFR CONDITIONS POSSIBLE WITH OCCURRENCE OF
ANY SHOWERS OR THUNDERSTORMS. CONVECTION WILL LIKELY LINGER INTO
EVENING HOURS AND SUBSIDE THEREAFTER.
60
60
&&
.PREV DISCUSSION... /ISSUED 1015 AM EDT SAT MAY 19 2012/
UPDATE...UPDATED FORECAST PACKAGE TO MENTION POSSIBLE STRONG TO
SEVERE STORMS THIS AFTERNOON. 12Z SOUNDING PARAMETERS ALMOST
IDENTICAL TO FRIDAY`S VALUES. PW=1.72 INCHES, 500 MB TEMP AROUND
-10C TO -11C AND THE LIKELIHOOD OF WET MICROBURSTS AND LARGE HAIL. 850 MB
ANALYSIS ALSO SHOWS A WEAK TROUGH MOVING SLOWLY EASTWARD ACROSS
SOUTH FLORIDA. THIS COMBINED WITH PLENTY OF HEATING AND LEFT-OVER
OUTFLOW BOUNDARIES FROM YESTERDAY`S CONVECTIVE ACTIVITY WILL LEAD TO
THUNDERSTORMS DEVELOPING JUST ABOUT ANYWHERE IN S. FLORIDA. HOWEVER,
WESTERLY MID/UPPER LEVEL FLOW MAY STEER ANY STORM EASTWARD TOWARD
THE EASTERN INTERIOR AND EASTERN METRO AREAS.
AVIATION...
THE WINDS WILL REMAIN LIGHT EARLY THIS MORNING BEFORE BECOMING
SOUTHEAST AT 5 TO 10 KNOTS AFTER 13Z TODAY. THE ONLY EXCEPTION TO
THIS IS AT KAPF WHERE THE WINDS WILL BE EASTERLY THIS MORNING BEFORE
SWINGING TO A WESTERLY DIRECTION AROUND 16Z TODAY...DUE TO THE WEST
COAST SEA BREEZE DEVELOPING AND PUSHING INLAND. CONVECTION IS
EXPECTED ACROSS THE PENINSULA TODAY...WITH VCSH ASSIGNED ALL
TERMINALS THROUGH 15Z AND VCTS ASSIGNED ALL TERMINALS AT 16Z.
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL ALL TERMINALS THROUGH
15Z AND STARTING AT 16Z PERIODS OF SUB-VFR CONDITIONS AND BRIEF
PERIODS OF IFR CONDITIONS POSSIBLE WITH OCCURRENCE OF SHOWERS
AND/OR THUNDERSTORMS.
60
PREV DISCUSSION... /ISSUED 347 AM EDT SAT MAY 19 2012/
SHORT RANGE (TODAY-MONDAY)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A BROAD TROUGH CENTERED
OVER THE SOUTHEAST WITH A NOTABLE SHORTWAVE TROUGH EXTENDING
SOUTHWEST FROM THE FLORIDA PANHANDLE TO THE CENTRAL GULF AND PLENTY
OF MID/UPPER MOISTURE SPREADING EAST-NORTHEAST ACROSS SOUTH
FLORIDA...THE KEYS AND FLORIDA STRAITS. THE LATEST SURFACE ANALYSIS
SHOWED A WEAKNESS WITHIN THE SUBTROPICAL RIDGE ACROSS THE LOCAL AREA
WITH A TROUGH OR FRONTAL BOUNDARY EXTENDING SOUTHWEST FROM A LOW
PRESSURE CENTERED OFF THE CAROLINA COAST TO CENTRAL FL.
THE MODELS HAVE INITIALIZED WELL WITH THIS SYNOPTIC PATTERN AND
INDICATE ANOTHER POTENTIALLY ACTIVE DAY ACROSS THE FLORIDA
PENINSULA...SIMILAR TO YESTERDAY. THE AFOREMENTIONED SHORTWAVE
TROUGH WILL ROTATE EASTWARD AROUND THE BASE OF THE UPPER TROUGH
AND MOVE ACROSS THE AREA TODAY FROM WEST TO EAST...WHICH WILL LEAD
TO DECREASING UPPER HEIGHTS AND SOME COOLER MID-LEVEL AIR (-10 TO
-11 C 500 MB TEMPS) SPREADING OVER THE AREA THIS AFTERNOON. THIS
COMBINED WITH A WEAK SFC TROUGH AND LOW-LEVEL CONVERGENCE
ASSOCIATED WITH THE EAST/WEST COAST SEA BREEZES WILL BE ENOUGH TO
INITIATE ANOTHER ROUND OF AFTERNOON CONVECTION. THE ONE DIFFERENCE
TODAY COMPARED TO YESTERDAY IS THAT THE LOW-LEVEL FLOW WILL HAVE
MORE OF AN EASTERLY COMPONENT...WHICH SHOULD HELP CONCENTRATE THE
CONVECTIVE ACTIVITY OVER THE INTERIOR SECTIONS INITIALLY. THE
LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THIS AND
GENERALLY INDICATE CONVECTION BEGINNING BY 18Z OVER THESE INTERIOR
LOCATIONS. WITH THE DRIER/COOLER MID-LEVEL AIR EXPECTED...THE MAIN
THREATS WITH THE STRONGER STORMS THAT DEVELOP WILL BE DAMAGING
STRAIGHT LINE WINDS AND HAIL.
TONIGHT THROUGH MONDAY...SIMILAR CONDITIONS WILL BE EXPECTED EACH
DAY WITH SCATTERED AFTERNOON SHOWERS/TSTMS DEVELOPING OVER THE
INTERIOR SECTIONS ASSOCIATED WITH THE PERSISTENT UPPER TROUGH AND
AFTERNOON SEA BREEZES.
LONG RANGE (MONDAY NIGHT-FRIDAY)...
THE GFS/GFS ENSEMBLE MEAN/ECMWF GENERALLY ALL MAINTAIN THE
MID/UPPER TROUGH OVER THE SOUTHEAST REGION WITH DRY MID/UPPER
WESTERLY FLOW CONTINUING ACROSS THE FL PENINSULA. AT THE
SURFACE...ALTHOUGH THERE REMAINS SOME DIFFERENCES NOTED BETWEEN THE
MODEL SOLUTIONS...THE GFS/ECMWF GENERALLY INDICATE A WEAK TROUGH
EXTENDING NORTHEAST FROM A BROAD LOW CENTERED OVER THE WESTERN
CARIBBEAN ACROSS THE FLORIDA STRAITS...WHICH MAY HELP CONCENTRATE
ANY DEEP MOIST CONVECTION JUST SOUTH OF OUR LOCAL AREA ACROSS THE
KEYS AND STRAITS. OTHERWISE...MORE OF A SEASONAL PATTERN WITH 20-30
PERCENT RAINFALL CHANCES EACH DAY ASSOCIATED WITH THE AFTERNOON SEA
BREEZES WILL REMAIN IN THE FORECAST. TEMPERATURES WILL REMAIN AROUND
NORMAL THROUGH THIS TIME WITH HIGHS IN THE UPPER 80S AND LOWS IN THE
LOWER 70S.
MARINE...
A WEAK PRESSURE GRADIENT WILL RESULT IN LIGHT EASTERLY WINDS
AND LOW SEAS CONTINUING THROUGH THE WEEKEND AND INTO THE UPCOMING
WEEK. SCATTERED SHOWERS AND THUNDERSTORMS COULD LEAD TO BRIEF
PERIODS WITH LOCALLY HIGHER WINDS AND SEAS.
AVIATION...
THE WINDS WILL REMAIN LIGHT EARLY THIS MORNING BEFORE BECOMING
SOUTHEAST AT 5 TO 10 KNOTS AFTER 13Z TODAY. THE ONLY EXCEPTION TO
THIS IS AT KAPF WHERE THE WINDS WILL BE EASTERLY THIS MORNING
BEFORE SWINGING TO A WESTERLY DIRECTION AROUND 17Z TODAY...DUE TO
THE WEST COAST SEA BREEZE DEVELOPING AND PUSHING INLAND.
THE WEATHER WILL ALSO REMAIN DRY THROUGH 13Z TODAY...BEFORE VCSH
FOR ALL TAF SITES BETWEEN 13Z AND 17Z. THUNDERSTORMS WILL THEN
DEVELOP THIS AFTERNOON ALONG THE SEA BREEZE AND PUSH SLOWLY INLAND
OVER THE COAST AREAS...WHILE THE WEST COAST SEA BREEZE PUSHES MORE
INLAND. SO WILL INTRODUCE VCTS FOR THE EAST COAST TAF SITES
BETWEEN 17Z AND 23Z TODAY...WHILE THE KAPF TAF SITE REMAINS IN THE
VCSH FOR THE AFTERNOON HOURS. THE ACTIVITY WILL THEN DISSIPATE
BETWEEN 00Z AND 02Z TONIGHT OVER ALL OF THE TAF SITES...AS THE
HEATING OF THE DAY IS LOST. SO AFTER 02Z TONIGHT THE WEATHER WILL
BE DRY AGAIN.
THE CEILING AND VIS WILL REMAIN IN THE VFR CONDITIONS THROUGH
TODAY...DUE TO THE UNKNOWN TIMING OF THE SHOWERS AND THUNDERSTORMS
FOR TODAY.
FIRE WEATHER...
SOME STRONG TO SEVERE STORMS ARE POSSIBLE THIS AFTERNOON OVER
SOUTH FLORIDA ESPECIALLY WHERE THE EAST AND WEST COAST SEA BREEZES
COLLIDE OVER THE INTERIOR AREAS. THE PRIMARY IMPACTS FROM THE
STRONGEST STORMS WILL BE FREQUENT LIGHTNING STRIKES...GUSTY
WINDS...HAIL UP TO QUARTER SIZE...AND HEAVY RAINFALL. THE BEST
TIME TO SEE THE STORMS WILL IN THE AFTERNOON AND EARLY EVENING HOURS.
THE RELATIVE HUMIDITIES TODAY WILL REMAIN ABOVE THE 35 PERCENT
CRITICAL VALUE..AS THE DISPERSION INDEX WILL RANGE FROM THE 20S
INTERIOR AREAS TO 40 ALONG THE METRO AREAS. THE DISPERSION INDEX
FOR TONIGHT WILL BE LESS THAN 5. THIS MEANS THAT THE MIXING FOR
TODAY IS IN THE FAIR TO GOOD RANGE...WHILE TONIGHT IT IS IN THE
VERY POOR RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 71 85 73 86 / 40 30 20 30
FORT LAUDERDALE 72 86 74 86 / 40 30 20 30
MIAMI 73 86 73 87 / 40 30 20 30
NAPLES 70 86 71 87 / 20 40 20 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...47/RGH
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
1015 AM EDT SAT MAY 19 2012
.UPDATE...UPDATED FORECAST PACKAGE TO MENTION POSSIBLE STRONG TO
SEVERE STORMS THIS AFTERNOON. 12Z SOUNDING PARAMETERS ALMOST
IDENTICAL TO FRIDAY`S VALUES. PW=1.72 INCHES, 500 MB TEMP AROUND
-10C TO -11C AND THE LIKELIHOOD OF WET MICROBURSTS AND LARGE HAIL. 850 MB
ANALYSIS ALSO SHOWS A WEAK TROUGH MOVING SLOWLY EASTWARD ACROSS
SOUTH FLORIDA. THIS COMBINED WITH PLENTY OF HEATING AND LEFT-OVER
OUTFLOW BOUNDARIES FROM YESTERDAY`S CONVECTIVE ACTIVITY WILL LEAD TO
THUNDERSTORMS DEVELOPING JUST ABOUT ANYWHERE IN S. FLORIDA. HOWEVER,
WESTERLY MID/UPPER LEVEL FLOW MAY STEER ANY STORM EASTWARD TOWARD
THE EASTERN INTERIOR AND EASTERN METRO AREAS.
.AVIATION...
THE WINDS WILL REMAIN LIGHT EARLY THIS MORNING BEFORE BECOMING
SOUTHEAST AT 5 TO 10 KNOTS AFTER 13Z TODAY. THE ONLY EXCEPTION TO
THIS IS AT KAPF WHERE THE WINDS WILL BE EASTERLY THIS MORNING BEFORE
SWINGING TO A WESTERLY DIRECTION AROUND 16Z TODAY...DUE TO THE WEST
COAST SEA BREEZE DEVELOPING AND PUSHING INLAND. CONVECTION IS
EXPECTED ACROSS THE PENINSULA TODAY...WITH VCSH ASSIGNED ALL
TERMINALS THROUGH 15Z AND VCTS ASSIGNED ALL TERMINALS AT 16Z.
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL ALL TERMINALS THROUGH
15Z AND STARTING AT 16Z PERIODS OF SUB-VFR CONDITIONS AND BRIEF
PERIODS OF IFR CONDITIONS POSSIBLE WITH OCCURRENCE OF SHOWERS
AND/OR THUNDERSTORMS.
60
&&
.PREV DISCUSSION... /ISSUED 347 AM EDT SAT MAY 19 2012/
SHORT RANGE (TODAY-MONDAY)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A BROAD TROUGH CENTERED
OVER THE SOUTHEAST WITH A NOTABLE SHORTWAVE TROUGH EXTENDING
SOUTHWEST FROM THE FLORIDA PANHANDLE TO THE CENTRAL GULF AND PLENTY
OF MID/UPPER MOISTURE SPREADING EAST-NORTHEAST ACROSS SOUTH
FLORIDA...THE KEYS AND FLORIDA STRAITS. THE LATEST SURFACE ANALYSIS
SHOWED A WEAKNESS WITHIN THE SUBTROPICAL RIDGE ACROSS THE LOCAL AREA
WITH A TROUGH OR FRONTAL BOUNDARY EXTENDING SOUTHWEST FROM A LOW
PRESSURE CENTERED OFF THE CAROLINA COAST TO CENTRAL FL.
THE MODELS HAVE INITIALIZED WELL WITH THIS SYNOPTIC PATTERN AND
INDICATE ANOTHER POTENTIALLY ACTIVE DAY ACROSS THE FLORIDA
PENINSULA...SIMILAR TO YESTERDAY. THE AFOREMENTIONED SHORTWAVE
TROUGH WILL ROTATE EASTWARD AROUND THE BASE OF THE UPPER TROUGH
AND MOVE ACROSS THE AREA TODAY FROM WEST TO EAST...WHICH WILL LEAD
TO DECREASING UPPER HEIGHTS AND SOME COOLER MID-LEVEL AIR (-10 TO
-11 C 500 MB TEMPS) SPREADING OVER THE AREA THIS AFTERNOON. THIS
COMBINED WITH A WEAK SFC TROUGH AND LOW-LEVEL CONVERGENCE
ASSOCIATED WITH THE EAST/WEST COAST SEA BREEZES WILL BE ENOUGH TO
INITIATE ANOTHER ROUND OF AFTERNOON CONVECTION. THE ONE DIFFERENCE
TODAY COMPARED TO YESTERDAY IS THAT THE LOW-LEVEL FLOW WILL HAVE
MORE OF AN EASTERLY COMPONENT...WHICH SHOULD HELP CONCENTRATE THE
CONVECTIVE ACTIVITY OVER THE INTERIOR SECTIONS INITIALLY. THE
LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THIS AND
GENERALLY INDICATE CONVECTION BEGINNING BY 18Z OVER THESE INTERIOR
LOCATIONS. WITH THE DRIER/COOLER MID-LEVEL AIR EXPECTED...THE MAIN
THREATS WITH THE STRONGER STORMS THAT DEVELOP WILL BE DAMAGING
STRAIGHT LINE WINDS AND HAIL.
TONIGHT THROUGH MONDAY...SIMILAR CONDITIONS WILL BE EXPECTED EACH
DAY WITH SCATTERED AFTERNOON SHOWERS/TSTMS DEVELOPING OVER THE
INTERIOR SECTIONS ASSOCIATED WITH THE PERSISTENT UPPER TROUGH AND
AFTERNOON SEA BREEZES.
LONG RANGE (MONDAY NIGHT-FRIDAY)...
THE GFS/GFS ENSEMBLE MEAN/ECMWF GENERALLY ALL MAINTAIN THE
MID/UPPER TROUGH OVER THE SOUTHEAST REGION WITH DRY MID/UPPER
WESTERLY FLOW CONTINUING ACROSS THE FL PENINSULA. AT THE
SURFACE...ALTHOUGH THERE REMAINS SOME DIFFERENCES NOTED BETWEEN THE
MODEL SOLUTIONS...THE GFS/ECMWF GENERALLY INDICATE A WEAK TROUGH
EXTENDING NORTHEAST FROM A BROAD LOW CENTERED OVER THE WESTERN
CARIBBEAN ACROSS THE FLORIDA STRAITS...WHICH MAY HELP CONCENTRATE
ANY DEEP MOIST CONVECTION JUST SOUTH OF OUR LOCAL AREA ACROSS THE
KEYS AND STRAITS. OTHERWISE...MORE OF A SEASONAL PATTERN WITH 20-30
PERCENT RAINFALL CHANCES EACH DAY ASSOCIATED WITH THE AFTERNOON SEA
BREEZES WILL REMAIN IN THE FORECAST. TEMPERATURES WILL REMAIN AROUND
NORMAL THROUGH THIS TIME WITH HIGHS IN THE UPPER 80S AND LOWS IN THE
LOWER 70S.
MARINE...
A WEAK PRESSURE GRADIENT WILL RESULT IN LIGHT EASTERLY WINDS
AND LOW SEAS CONTINUING THROUGH THE WEEKEND AND INTO THE UPCOMING
WEEK. SCATTERED SHOWERS AND THUNDERSTORMS COULD LEAD TO BRIEF
PERIODS WITH LOCALLY HIGHER WINDS AND SEAS.
AVIATION...
THE WINDS WILL REMAIN LIGHT EARLY THIS MORNING BEFORE BECOMING
SOUTHEAST AT 5 TO 10 KNOTS AFTER 13Z TODAY. THE ONLY EXCEPTION TO
THIS IS AT KAPF WHERE THE WINDS WILL BE EASTERLY THIS MORNING
BEFORE SWINGING TO A WESTERLY DIRECTION AROUND 17Z TODAY...DUE TO
THE WEST COAST SEA BREEZE DEVELOPING AND PUSHING INLAND.
THE WEATHER WILL ALSO REMAIN DRY THROUGH 13Z TODAY...BEFORE VCSH
FOR ALL TAF SITES BETWEEN 13Z AND 17Z. THUNDERSTORMS WILL THEN
DEVELOP THIS AFTERNOON ALONG THE SEA BREEZE AND PUSH SLOWLY INLAND
OVER THE COAST AREAS...WHILE THE WEST COAST SEA BREEZE PUSHES MORE
INLAND. SO WILL INTRODUCE VCTS FOR THE EAST COAST TAF SITES
BETWEEN 17Z AND 23Z TODAY...WHILE THE KAPF TAF SITE REMAINS IN THE
VCSH FOR THE AFTERNOON HOURS. THE ACTIVITY WILL THEN DISSIPATE
BETWEEN 00Z AND 02Z TONIGHT OVER ALL OF THE TAF SITES...AS THE
HEATING OF THE DAY IS LOST. SO AFTER 02Z TONIGHT THE WEATHER WILL
BE DRY AGAIN.
THE CEILING AND VIS WILL REMAIN IN THE VFR CONDITIONS THROUGH
TODAY...DUE TO THE UNKNOWN TIMING OF THE SHOWERS AND THUNDERSTORMS
FOR TODAY.
FIRE WEATHER...
SOME STRONG TO SEVERE STORMS ARE POSSIBLE THIS AFTERNOON OVER
SOUTH FLORIDA ESPECIALLY WHERE THE EAST AND WEST COAST SEA BREEZES
COLLIDE OVER THE INTERIOR AREAS. THE PRIMARY IMPACTS FROM THE
STRONGEST STORMS WILL BE FREQUENT LIGHTNING STRIKES...GUSTY
WINDS...HAIL UP TO QUARTER SIZE...AND HEAVY RAINFALL. THE BEST
TIME TO SEE THE STORMS WILL IN THE AFTERNOON AND EARLY EVENING HOURS.
THE RELATIVE HUMIDITIES TODAY WILL REMAIN ABOVE THE 35 PERCENT
CRITICAL VALUE..AS THE DISPERSION INDEX WILL RANGE FROM THE 20S
INTERIOR AREAS TO 40 ALONG THE METRO AREAS. THE DISPERSION INDEX
FOR TONIGHT WILL BE LESS THAN 5. THIS MEANS THAT THE MIXING FOR
TODAY IS IN THE FAIR TO GOOD RANGE...WHILE TONIGHT IT IS IN THE
VERY POOR RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 85 71 85 73 / 50 40 30 20
FORT LAUDERDALE 85 72 86 74 / 50 40 30 20
MIAMI 86 73 86 73 / 50 40 30 20
NAPLES 86 70 86 71 / 40 20 40 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...47/RGH
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
730 AM EDT SAT MAY 19 2012
.AVIATION...
THE WINDS WILL REMAIN LIGHT EARLY THIS MORNING BEFORE BECOMING
SOUTHEAST AT 5 TO 10 KNOTS AFTER 13Z TODAY. THE ONLY EXCEPTION TO
THIS IS AT KAPF WHERE THE WINDS WILL BE EASTERLY THIS MORNING BEFORE
SWINGING TO A WESTERLY DIRECTION AROUND 16Z TODAY...DUE TO THE WEST
COAST SEA BREEZE DEVELOPING AND PUSHING INLAND. CONVECTION IS
EXPECTED ACROSS THE PENINSULA TODAY...WITH VCSH ASSIGNED ALL
TERMINALS THROUGH 15Z AND VCTS ASSIGNED ALL TERMINALS AT 16Z.
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL ALL TERMINALS THROUGH
15Z AND STARTING AT 16Z PERIODS OF SUB-VFR CONDITIONS AND BRIEF
PERIODS OF IFR CONDITIONS POSSIBLE WITH OCCURRENCE OF SHOWERS
AND/OR THUNDERSTORMS.
60
&&
.PREV DISCUSSION... /ISSUED 347 AM EDT SAT MAY 19 2012/
SHORT RANGE (TODAY-MONDAY)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A BROAD TROUGH CENTERED
OVER THE SOUTHEAST WITH A NOTABLE SHORTWAVE TROUGH EXTENDING
SOUTHWEST FROM THE FLORIDA PANHANDLE TO THE CENTRAL GULF AND PLENTY
OF MID/UPPER MOISTURE SPREADING EAST-NORTHEAST ACROSS SOUTH
FLORIDA...THE KEYS AND FLORIDA STRAITS. THE LATEST SURFACE ANALYSIS
SHOWED A WEAKNESS WITHIN THE SUBTROPICAL RIDGE ACROSS THE LOCAL AREA
WITH A TROUGH OR FRONTAL BOUNDARY EXTENDING SOUTHWEST FROM A LOW
PRESSURE CENTERED OFF THE CAROLINA COAST TO CENTRAL FL.
THE MODELS HAVE INITIALIZED WELL WITH THIS SYNOPTIC PATTERN AND
INDICATE ANOTHER POTENTIALLY ACTIVE DAY ACROSS THE FLORIDA
PENINSULA...SIMILAR TO YESTERDAY. THE AFOREMENTIONED SHORTWAVE
TROUGH WILL ROTATE EASTWARD AROUND THE BASE OF THE UPPER TROUGH
AND MOVE ACROSS THE AREA TODAY FROM WEST TO EAST...WHICH WILL LEAD
TO DECREASING UPPER HEIGHTS AND SOME COOLER MID-LEVEL AIR (-10 TO
-11 C 500 MB TEMPS) SPREADING OVER THE AREA THIS AFTERNOON. THIS
COMBINED WITH A WEAK SFC TROUGH AND LOW-LEVEL CONVERGENCE
ASSOCIATED WITH THE EAST/WEST COAST SEA BREEZES WILL BE ENOUGH TO
INITIATE ANOTHER ROUND OF AFTERNOON CONVECTION. THE ONE DIFFERENCE
TODAY COMPARED TO YESTERDAY IS THAT THE LOW-LEVEL FLOW WILL HAVE
MORE OF AN EASTERLY COMPONENT...WHICH SHOULD HELP CONCENTRATE THE
CONVECTIVE ACTIVITY OVER THE INTERIOR SECTIONS INITIALLY. THE
LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THIS AND
GENERALLY INDICATE CONVECTION BEGINNING BY 18Z OVER THESE INTERIOR
LOCATIONS. WITH THE DRIER/COOLER MID-LEVEL AIR EXPECTED...THE MAIN
THREATS WITH THE STRONGER STORMS THAT DEVELOP WILL BE DAMAGING
STRAIGHT LINE WINDS AND HAIL.
TONIGHT THROUGH MONDAY...SIMILAR CONDITIONS WILL BE EXPECTED EACH
DAY WITH SCATTERED AFTERNOON SHOWERS/TSTMS DEVELOPING OVER THE
INTERIOR SECTIONS ASSOCIATED WITH THE PERSISTENT UPPER TROUGH AND
AFTERNOON SEA BREEZES.
LONG RANGE (MONDAY NIGHT-FRIDAY)...
THE GFS/GFS ENSEMBLE MEAN/ECMWF GENERALLY ALL MAINTAIN THE
MID/UPPER TROUGH OVER THE SOUTHEAST REGION WITH DRY MID/UPPER
WESTERLY FLOW CONTINUING ACROSS THE FL PENINSULA. AT THE
SURFACE...ALTHOUGH THERE REMAINS SOME DIFFERENCES NOTED BETWEEN THE
MODEL SOLUTIONS...THE GFS/ECMWF GENERALLY INDICATE A WEAK TROUGH
EXTENDING NORTHEAST FROM A BROAD LOW CENTERED OVER THE WESTERN
CARIBBEAN ACROSS THE FLORIDA STRAITS...WHICH MAY HELP CONCENTRATE
ANY DEEP MOIST CONVECTION JUST SOUTH OF OUR LOCAL AREA ACROSS THE
KEYS AND STRAITS. OTHERWISE...MORE OF A SEASONAL PATTERN WITH 20-30
PERCENT RAINFALL CHANCES EACH DAY ASSOCIATED WITH THE AFTERNOON SEA
BREEZES WILL REMAIN IN THE FORECAST. TEMPERATURES WILL REMAIN AROUND
NORMAL THROUGH THIS TIME WITH HIGHS IN THE UPPER 80S AND LOWS IN THE
LOWER 70S.
MARINE...
A WEAK PRESSURE GRADIENT WILL RESULT IN LIGHT EASTERLY WINDS
AND LOW SEAS CONTINUING THROUGH THE WEEKEND AND INTO THE UPCOMING
WEEK. SCATTERED SHOWERS AND THUNDERSTORMS COULD LEAD TO BRIEF
PERIODS WITH LOCALLY HIGHER WINDS AND SEAS.
AVIATION...
THE WINDS WILL REMAIN LIGHT EARLY THIS MORNING BEFORE BECOMING
SOUTHEAST AT 5 TO 10 KNOTS AFTER 13Z TODAY. THE ONLY EXCEPTION TO
THIS IS AT KAPF WHERE THE WINDS WILL BE EASTERLY THIS MORNING
BEFORE SWINGING TO A WESTERLY DIRECTION AROUND 17Z TODAY...DUE TO
THE WEST COAST SEA BREEZE DEVELOPING AND PUSHING INLAND.
THE WEATHER WILL ALSO REMAIN DRY THROUGH 13Z TODAY...BEFORE VCSH
FOR ALL TAF SITES BETWEEN 13Z AND 17Z. THUNDERSTORMS WILL THEN
DEVELOP THIS AFTERNOON ALONG THE SEA BREEZE AND PUSH SLOWLY INLAND
OVER THE COAST AREAS...WHILE THE WEST COAST SEA BREEZE PUSHES MORE
INLAND. SO WILL INTRODUCE VCTS FOR THE EAST COAST TAF SITES
BETWEEN 17Z AND 23Z TODAY...WHILE THE KAPF TAF SITE REMAINS IN THE
VCSH FOR THE AFTERNOON HOURS. THE ACTIVITY WILL THEN DISSIPATE
BETWEEN 00Z AND 02Z TONIGHT OVER ALL OF THE TAF SITES...AS THE
HEATING OF THE DAY IS LOST. SO AFTER 02Z TONIGHT THE WEATHER WILL
BE DRY AGAIN.
THE CEILING AND VIS WILL REMAIN IN THE VFR CONDITIONS THROUGH
TODAY...DUE TO THE UNKNOWN TIMING OF THE SHOWERS AND THUNDERSTORMS
FOR TODAY.
FIRE WEATHER...
SOME STRONG TO SEVERE STORMS ARE POSSIBLE THIS AFTERNOON OVER
SOUTH FLORIDA ESPECIALLY WHERE THE EAST AND WEST COAST SEA BREEZES
COLLIDE OVER THE INTERIOR AREAS. THE PRIMARY IMPACTS FROM THE
STRONGEST STORMS WILL BE FREQUENT LIGHTNING STRIKES...GUSTY
WINDS...HAIL UP TO QUARTER SIZE...AND HEAVY RAINFALL. THE BEST
TIME TO SEE THE STORMS WILL IN THE AFTERNOON AND EARLY EVENING HOURS.
THE RELATIVE HUMIDITIES TODAY WILL REMAIN ABOVE THE 35 PERCENT
CRITICAL VALUE..AS THE DISPERSION INDEX WILL RANGE FROM THE 20S
INTERIOR AREAS TO 40 ALONG THE METRO AREAS. THE DISPERSION INDEX
FOR TONIGHT WILL BE LESS THAN 5. THIS MEANS THAT THE MIXING FOR
TODAY IS IN THE FAIR TO GOOD RANGE...WHILE TONIGHT IT IS IN THE
VERY POOR RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 85 71 85 73 / 50 40 30 20
FORT LAUDERDALE 85 72 86 74 / 50 40 30 20
MIAMI 86 73 86 73 / 50 40 30 20
NAPLES 86 70 86 71 / 40 20 40 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...47/RGH
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS MIAMI FL
347 AM EDT SAT MAY 19 2012
.SHORT RANGE (TODAY-MONDAY)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED A BROAD TROUGH CENTERED
OVER THE SOUTHEAST WITH A NOTABLE SHORTWAVE TROUGH EXTENDING
SOUTHWEST FROM THE FLORIDA PANHANDLE TO THE CENTRAL GULF AND PLENTY
OF MID/UPPER MOISTURE SPREADING EAST-NORTHEAST ACROSS SOUTH
FLORIDA...THE KEYS AND FLORIDA STRAITS. THE LATEST SURFACE ANALYSIS
SHOWED A WEAKNESS WITHIN THE SUBTROPICAL RIDGE ACROSS THE LOCAL AREA
WITH A TROUGH OR FRONTAL BOUNDARY EXTENDING SOUTHWEST FROM A LOW
PRESSURE CENTERED OFF THE CAROLINA COAST TO CENTRAL FL.
THE MODELS HAVE INITIALIZED WELL WITH THIS SYNOPTIC PATTERN AND
INDICATE ANOTHER POTENTIALLY ACTIVE DAY ACROSS THE FLORIDA
PENINSULA...SIMILAR TO YESTERDAY. THE AFOREMENTIONED SHORTWAVE
TROUGH WILL ROTATE EASTWARD AROUND THE BASE OF THE UPPER TROUGH
AND MOVE ACROSS THE AREA TODAY FROM WEST TO EAST...WHICH WILL LEAD
TO DECREASING UPPER HEIGHTS AND SOME COOLER MID-LEVEL AIR (-10 TO
-11 C 500 MB TEMPS) SPREADING OVER THE AREA THIS AFTERNOON. THIS
COMBINED WITH A WEAK SFC TROUGH AND LOW-LEVEL CONVERGENCE
ASSOCIATED WITH THE EAST/WEST COAST SEA BREEZES WILL BE ENOUGH TO
INITIATE ANOTHER ROUND OF AFTERNOON CONVECTION. THE ONE DIFFERENCE
TODAY COMPARED TO YESTERDAY IS THAT THE LOW-LEVEL FLOW WILL HAVE
MORE OF AN EASTERLY COMPONENT...WHICH SHOULD HELP CONCENTRATE THE
CONVECTIVE ACTIVITY OVER THE INTERIOR SECTIONS INITIALLY. THE
LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THIS AND
GENERALLY INDICATE CONVECTION BEGINNING BY 18Z OVER THESE INTERIOR
LOCATIONS. WITH THE DRIER/COOLER MID-LEVEL AIR EXPECTED...THE MAIN
THREATS WITH THE STRONGER STORMS THAT DEVELOP WILL BE DAMAGING
STRAIGHT LINE WINDS AND HAIL.
TONIGHT THROUGH MONDAY...SIMILAR CONDITIONS WILL BE EXPECTED EACH
DAY WITH SCATTERED AFTERNOON SHOWERS/TSTMS DEVELOPING OVER THE
INTERIOR SECTIONS ASSOCIATED WITH THE PERSISTENT UPPER TROUGH AND
AFTERNOON SEA BREEZES.
.LONG RANGE (MONDAY NIGHT-FRIDAY)...
THE GFS/GFS ENSEMBLE MEAN/ECMWF GENERALLY ALL MAINTAIN THE
MID/UPPER TROUGH OVER THE SOUTHEAST REGION WITH DRY MID/UPPER
WESTERLY FLOW CONTINUING ACROSS THE FL PENINSULA. AT THE
SURFACE...ALTHOUGH THERE REMAINS SOME DIFFERENCES NOTED BETWEEN THE
MODEL SOLUTIONS...THE GFS/ECMWF GENERALLY INDICATE A WEAK TROUGH
EXTENDING NORTHEAST FROM A BROAD LOW CENTERED OVER THE WESTERN
CARIBBEAN ACROSS THE FLORIDA STRAITS...WHICH MAY HELP CONCENTRATE
ANY DEEP MOIST CONVECTION JUST SOUTH OF OUR LOCAL AREA ACROSS THE
KEYS AND STRAITS. OTHERWISE...MORE OF A SEASONAL PATTERN WITH 20-30
PERCENT RAINFALL CHANCES EACH DAY ASSOCIATED WITH THE AFTERNOON SEA
BREEZES WILL REMAIN IN THE FORECAST. TEMPERATURES WILL REMAIN AROUND
NORMAL THROUGH THIS TIME WITH HIGHS IN THE UPPER 80S AND LOWS IN THE
LOWER 70S.
&&
.MARINE...
A WEAK PRESSURE GRADIENT WILL RESULT IN LIGHT EASTERLY WINDS
AND LOW SEAS CONTINUING THROUGH THE WEEKEND AND INTO THE UPCOMING
WEEK. SCATTERED SHOWERS AND THUNDERSTORMS COULD LEAD TO BRIEF
PERIODS WITH LOCALLY HIGHER WINDS AND SEAS.
&&
.AVIATION...
THE WINDS WILL REMAIN LIGHT EARLY THIS MORNING BEFORE BECOMING
SOUTHEAST AT 5 TO 10 KNOTS AFTER 13Z TODAY. THE ONLY EXCEPTION TO
THIS IS AT KAPF WHERE THE WINDS WILL BE EASTERLY THIS MORNING
BEFORE SWINGING TO A WESTERLY DIRECTION AROUND 17Z TODAY...DUE TO
THE WEST COAST SEA BREEZE DEVELOPING AND PUSHING INLAND.
THE WEATHER WILL ALSO REMAIN DRY THROUGH 13Z TODAY...BEFORE VCSH
FOR ALL TAF SITES BETWEEN 13Z AND 17Z. THUNDERSTORMS WILL THEN
DEVELOP THIS AFTERNOON ALONG THE SEA BREEZE AND PUSH SLOWLY INLAND
OVER THE COAST AREAS...WHILE THE WEST COAST SEA BREEZE PUSHES MORE
INLAND. SO WILL INTRODUCE VCTS FOR THE EAST COAST TAF SITES
BETWEEN 17Z AND 23Z TODAY...WHILE THE KAPF TAF SITE REMAINS IN THE
VCSH FOR THE AFTERNOON HOURS. THE ACTIVITY WILL THEN DISSIPATE
BETWEEN 00Z AND 02Z TONIGHT OVER ALL OF THE TAF SITES...AS THE
HEATING OF THE DAY IS LOST. SO AFTER 02Z TONIGHT THE WEATHER WILL
BE DRY AGAIN.
THE CEILING AND VIS WILL REMAIN IN THE VFR CONDITIONS THROUGH
TODAY...DUE TO THE UNKNOWN TIMING OF THE SHOWERS AND THUNDERSTORMS
FOR TODAY.
&&
.FIRE WEATHER...
SOME STRONG TO SEVERE STORMS ARE POSSIBLE THIS AFTERNOON OVER
SOUTH FLORIDA ESPECIALLY WHERE THE EAST AND WEST COAST SEA BREEZES
COLLIDE OVER THE INTERIOR AREAS. THE PRIMARY IMPACTS FROM THE
STRONGEST STORMS WILL BE FREQUENT LIGHTNING STRIKES...GUSTY
WINDS...HAIL UP TO QUARTER SIZE...AND HEAVY RAINFALL. THE BEST
TIME TO SEE THE STORMS WILL IN THE AFTERNOON AND EARLY EVENING HOURS.
THE RELATIVE HUMIDITIES TODAY WILL REMAIN ABOVE THE 35 PERCENT
CRITICAL VALUE..AS THE DISPERSION INDEX WILL RANGE FROM THE 20S
INTERIOR AREAS TO 40 ALONG THE METRO AREAS. THE DISPERSION INDEX
FOR TONIGHT WILL BE LESS THAN 5. THIS MEANS THAT THE MIXING FOR
TODAY IS IN THE FAIR TO GOOD RANGE...WHILE TONIGHT IT IS IN THE
VERY POOR RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 85 71 85 73 / 50 50 30 20
FORT LAUDERDALE 85 72 86 74 / 50 50 30 20
MIAMI 86 73 86 73 / 50 50 30 20
NAPLES 86 70 86 71 / 40 20 40 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...54/BNB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
636 AM CDT SAT MAY 19 2012
.UPDATE...
SEE THE CLIMATE SECTION REGARDING RECORD HIGHS FOR MAY 19TH.
A VERY MINOR TWEAK WAS DONE WITH THE HRLY TEMPERATURES TO BETTER
REFLECT CURRENT TRENDS. BASED ON FCST MAX TEMPERATURES TODAY SOME
SITES MAY BE NEAR RECORD TERRITORY. EVERYTHING WILL DEPEND UPON
THE AMOUNT OF CI/CS BLOW OFF FROM CONVECTION ALONG THE MISSOURI
RIVER. RAP TRENDS WITH THE LIFT TOOL INDICATES THAT THIS
CONVECTION WILL DISSIPATE DURING THE MORNING AS THE LLJ WEAKENS.
THE OUTFLOW BOUNDARY WOULD PROVIDE A FOCUS FOR DIURNAL CONVECTION
DURING THE AFTERNOON.
THE LIFT TOOL AND RAP TRENDS STILL INDICATE CONVECTION SHOULD FIRE
CLOSE TO THE MISSOURI RIVER THIS AFTERNOON BUT THERE MAY BE SOME
ISOLATED TO SCATTERED CONVECTION DEVELOPING ON THE REMNANT OUTFLOW
BOUNDARY IN CENTRAL IOWA LATE THIS AFTERNOON. THE LIFT TOOL STILL
SUGGESTS THE LATE AFTERNOON AND EVENING HOURS SHOULD BE DRY IN THE
CWFA. ..08..
&&
.AVIATION...
VFR WX WILL BE SEEN THROUGH 09Z/20. INVERSION SHOULD BREAK 15Z-
16Z/19 ALLOWING DEEPER MIXING TO OCCUR AND INCREASE WINDS. WINDS
SHOULD DROP OFF AROUND 00Z/20 AS THE INVERSION BECOMES RE-
ESTABLISHED. KCID HAS THE BEST CHANCE AT SEEING VCTS AFT 09Z/20
BUT CONVECTION MAY HOLD OFF UNTIL 12Z/20 OR LATER. IF CONVECTION
DOES OCCUR AT KCID THERE WOULD BE A POTENTIAL FOR MVFR CONDITIONS.
KDBQ/KMLI/KBRL ARE EXPECTED TO REMAIN VFR THROUGH 12Z/20. ..08..
&&
.CLIMATE...
RECORD HIGHS FOR MAY 19...
MOLINE.........93 IN 1962
CEDAR RAPIDS...93 IN 1975
DUBUQUE........93 IN 1934
BURLINGTON.....93 IN 1998
&&
.PREV DISCUSSION... /ISSUED 305 AM CDT SAT MAY 19 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS THE FRONT WITH LOW PRESSURE CENTERS ALONG IT
RUNNING FROM NORTHWEST MINNESOTA INTO NORTHERN COLORADO. A MESO HIGH
ASSOCIATED WITH A SMALL MCS WAS ACROSS NEBRASKA WHILE A DRY LINE RAN
FROM FROM NEAR KMCK TO KCVS. DEW POINTS WERE IN THE 40S ACROSS THE
GREAT LAKES WITH 50S OVER MUCH OF THE MIDWEST.
SHORT TERM...TODAY AND TONIGHT
VERY WARM AND BREEZY CONDITIONS WILL BE SEEN ACROSS THE AREA TODAY.
IF THE SAME NEAR 30 DEGREE DIURNAL SWING TAKES PLACE TODAY THEN MAX
TEMPS WOULD BE IN THE LOW TO MID 90S. THE OVERALL WAA AND DEPTH OF
DEEP MIXING JUST DOES NOT SUPPORT TEMPERATURES THAT WARM. HOWEVER...
PERSISTENCE PLUS SEVERAL DEGREES WOULD SUPPORT UPPER 80S TO LOWER
90S FOR MAX TEMPS. DEW POINTS WILL BE ROUGHLY 10 DEGREES WARMER THAN
YESTERDAY BUT HUMIDITY LEVELS WILL STILL BE LOW.
TONIGHT...THE EVENING HOURS WILL BE DRY. MCS AND LIFT TOOLS INDICATE
CONVECTION WILL FIRE LATE THIS AFTERNOON/EVENING IN WESTERN IOWA
PROBABLY NOT FAR FROM THE MISSOURI RIVER. THE QUESTION IS WHETHER
SAID CONVECTION WILL MAKE IT INTO THE CWFA PRIOR TO SUNRISE.
INTERESTINGLY...ALL MODELS WEAKEN THE CONVERGENCE AFTER MIDNIGHT
ACROSS THE AREA. MCS...LIFT...AND HEAVY RAIN TOOLS OFFER MIXED
SIGNALS ON PRECIPITATION POTENTIAL. WHEN THE LIFT TOOL IS APPLIED TO
ALL THE MODELS...A WEAK BUT CONSISTENT SIGNAL EMERGES SUGGESTING THE
POSSIBILITY OF CONVECTION ENTERING THE FAR WESTERN CWFA JUST PRIOR
TO DAWN. SO...WILL CONFINE ANY PRECIP TO VERY LATE TONIGHT OVER THE
WESTERN QUARTER OR SO OF THE CWFA. HOWEVER...THE CONSISTENT
WEAKENING OF THE OVERALL CONVERGENCE BY THE MODELS DOES QUESTION THE
POTENTIAL FOR ANY PRECIPITATION ENTERING THE CWFA. ..08..
LONG TERM...SUNDAY THROUGH NEXT FRIDAY
SUNDAY THROUGH SUNDAY EVENING CONTINUES TO REPRESENT A FRONTAL
PASSAGE...WITH MODEST AT BEST MOISTURE...AND WEAK FORCING. THE
TIMING APPEARS TO HAVE SLOWED JUST ENOUGH TO HAVE THE FRONT WITHIN
EASTERN IOWA AT 18 TO 00Z...AND THUS A DIURNAL INCREASE IN
CONVECTION SHOULD AFFECT OUR CWA UNLESS THE TIMING SPEEDS UP AGAIN.
THE 18Z TO 00Z FROPA IS CONSISTENT IN MODEL GUIDANCE OTHER THAN THE
NAM...WHICH REMAINS 3 HOURS FASTER. QPF SHOULD BE GENERALLY
LIGHT...WITH BENEFICIAL AMOUNTS SPOTTY IN EXCESS OF A QUARTER INCH.
ANY STRONG STORMS WILL DEPEND GREATLY ON CAPE...AND AT THIS
POINT...WE ARE EXPECTING HIGHS IN THE LOWER TO MID 80S...WITH
DEWPOINTS AROUND 60. THIS WILL BE SUFFICIENT FOR THUNDER...BUT
DEPENDING ON WARM MID LEVEL TEMPS...WE MAY NOT SEE A LARGE CAPE
POOL.
BY LATER SUNDAY NIGHT...CAA AND DRY AIR SHOULD SWEEP IN...ENDING ANY
RAINFALL THREAT. MONDAY THROUGH TUESDAY...COOLER CANADIAN AIR SHOULD
BE OVER THE REGION...WITH HIGHS IN THE LOWER TO MID 70S...AND LOWS
IN THE LOWER TO MID 50S. THIS TWO DAY PERIOD REPRESENTS THE COOLEST
PORTION OF THE EXTENDED.
WEDNESDAY NIGHT THROUGH FRIDAY...THERE REMAIN LARGE DIFFERENCES IN
MODEL DATA. THE GFS CONTINUES TO SHIFT THE TROF/RIDGE EAST FAR
ENOUGH DURING THIS PERIOD TO WARRANT SHOWERS AND THUNDERSTORMS IN
OUR CWA BEGINNING THURSDAY. SHOULD THE GFS BE CORRECT...WITH SOME
SUPPORT FROM THE UKMET AS WELL...THIS MAY BE THE BEGINNING OF A 2 TO
4 DAY PERIOD OF ACTIVE STORMS. HOWEVER...CAPPING IS MOST CERTAINLY
GOING TO BE AN ISSUE...WITH THE ECMWF...CONSISTENTLY...SHOWING THE
ENTIRE PERIOD BEING HOT AND COMPLETELY DRY. WHILE BOTH
POSSIBILITIES REMAIN POSSIBLE...IT IS HARD TO IGNORE SUCH A STRONG
ECMWF SIGNAL TOWARDS SUNSHINE AND HOT AIR.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
305 AM CDT SAT MAY 19 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS THE FRONT WITH LOW PRESSURE CENTERS ALONG IT
RUNNING FROM NORTHWEST MINNESOTA INTO NORTHERN COLORADO. A MESO HIGH
ASSOCIATED WITH A SMALL MCS WAS ACROSS NEBRASKA WHILE A DRY LINE RAN
FROM FROM NEAR KMCK TO KCVS. DEW POINTS WERE IN THE 40S ACROSS THE
GREAT LAKES WITH 50S OVER MUCH OF THE MIDWEST.
&&
.SHORT TERM...TODAY AND TONIGHT
VERY WARM AND BREEZY CONDITIONS WILL BE SEEN ACROSS THE AREA TODAY.
IF THE SAME NEAR 30 DEGREE DIURNAL SWING TAKES PLACE TODAY THEN MAX
TEMPS WOULD BE IN THE LOW TO MID 90S. THE OVERALL WAA AND DEPTH OF
DEEP MIXING JUST DOES NOT SUPPORT TEMPERATURES THAT WARM. HOWEVER...
PERSISTENCE PLUS SEVERAL DEGREES WOULD SUPPORT UPPER 80S TO LOWER
90S FOR MAX TEMPS. DEW POINTS WILL BE ROUGHLY 10 DEGREES WARMER THAN
YESTERDAY BUT HUMIDITY LEVELS WILL STILL BE LOW.
TONIGHT...THE EVENING HOURS WILL BE DRY. MCS AND LIFT TOOLS INDICATE
CONVECTION WILL FIRE LATE THIS AFTERNOON/EVENING IN WESTERN IOWA
PROBABLY NOT FAR FROM THE MISSOURI RIVER. THE QUESTION IS WHETHER
SAID CONVECTION WILL MAKE IT INTO THE CWFA PRIOR TO SUNRISE.
INTERESTINGLY...ALL MODELS WEAKEN THE CONVERGENCE AFTER MIDNIGHT
ACROSS THE AREA. MCS...LIFT...AND HEAVY RAIN TOOLS OFFER MIXED
SIGNALS ON PRECIPITATION POTENTIAL. WHEN THE LIFT TOOL IS APPLIED TO
ALL THE MODELS...A WEAK BUT CONSISTENT SIGNAL EMERGES SUGGESTING THE
POSSIBILITY OF CONVECTION ENTERING THE FAR WESTERN CWFA JUST PRIOR
TO DAWN. SO...WILL CONFINE ANY PRECIP TO VERY LATE TONIGHT OVER THE
WESTERN QUARTER OR SO OF THE CWFA. HOWEVER...THE CONSISTENT
WEAKENING OF THE OVERALL CONVERGENCE BY THE MODELS DOES QUESTION THE
POTENTIAL FOR ANY PRECIPITATION ENTERING THE CWFA. ..08..
.LONG TERM...SUNDAY THROUGH NEXT FRIDAY
SUNDAY THROUGH SUNDAY EVENING CONTINUES TO REPRESENT A FRONTAL
PASSAGE...WITH MODEST AT BEST MOISTURE...AND WEAK FORCING. THE
TIMING APPEARS TO HAVE SLOWED JUST ENOUGH TO HAVE THE FRONT WITHIN
EASTERN IOWA AT 18 TO 00Z...AND THUS A DIURNAL INCREASE IN
CONVECTION SHOULD AFFECT OUR CWA UNLESS THE TIMING SPEEDS UP AGAIN.
THE 18Z TO 00Z FROPA IS CONSISTENT IN MODEL GUIDANCE OTHER THAN THE
NAM...WHICH REMAINS 3 HOURS FASTER. QPF SHOULD BE GENERALLY
LIGHT...WITH BENEFICIAL AMOUNTS SPOTTY IN EXCESS OF A QUARTER INCH.
ANY STRONG STORMS WILL DEPEND GREATLY ON CAPE...AND AT THIS
POINT...WE ARE EXPECTING HIGHS IN THE LOWER TO MID 80S...WITH
DEWPOINTS AROUND 60. THIS WILL BE SUFFICIENT FOR THUNDER...BUT
DEPENDING ON WARM MID LEVEL TEMPS...WE MAY NOT SEE A LARGE CAPE
POOL.
BY LATER SUNDAY NIGHT...CAA AND DRY AIR SHOULD SWEEP IN...ENDING ANY
RAINFALL THREAT. MONDAY THROUGH TUESDAY...COOLER CANADIAN AIR SHOULD
BE OVER THE REGION...WITH HIGHS IN THE LOWER TO MID 70S...AND LOWS
IN THE LOWER TO MID 50S. THIS TWO DAY PERIOD REPRESENTS THE COOLEST
PORTION OF THE EXTENDED.
WEDNESDAY NIGHT THROUGH FRIDAY...THERE REMAIN LARGE DIFFERENCES IN
MODEL DATA. THE GFS CONTINUES TO SHIFT THE TROF/RIDGE EAST FAR
ENOUGH DURING THIS PERIOD TO WARRANT SHOWERS AND THUNDERSTORMS IN
OUR CWA BEGINNING THURSDAY. SHOULD THE GFS BE CORRECT...WITH SOME
SUPPORT FROM THE UKMET AS WELL...THIS MAY BE THE BEGINNING OF A 2 TO
4 DAY PERIOD OF ACTIVE STORMS. HOWEVER...CAPPING IS MOST CERTAINLY
GOING TO BE AN ISSUE...WITH THE ECMWF...CONSISTENTLY...SHOWING THE
ENTIRE PERIOD BEING HOT AND COMPLETELY DRY. WHILE BOTH
POSSIBILITIES REMAIN POSSIBLE...IT IS HARD TO IGNORE SUCH A STRONG
ECMWF SIGNAL TOWARDS SUNSHINE AND HOT AIR.
ERVIN
&&
.AVIATION...
VFR WX WILL CONTINUE THROUGH 08Z/20. RADAR PROFILES SUGGEST THE
POTENTIAL FOR LLWS THROUGH SUNRISE BUT THE RAP MODEL TRENDS HAVE
LOWER WIND SPEEDS IN THE 1-2KFT AGL LAYER. WINDS WILL PICK UP AROUND
15Z/19 AS THE INVERSION BREAKS AND WILL DROP AGAIN AROUND SUNSET.
AFT 08Z/20 CONVECTION IN THE FORM OF SHRA/TSRA MAY AFFECT KCID.
CONDITIONS SHOULD REMAIN VFR BUT IF TSRA DO AFFECT KCID THERE IS A
POTENTIAL FOR MVFR CONDITIONS. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
314 PM CDT SAT MAY 19 2012
.DISCUSSION...
SYNOPSIS...SURFACE LOW PRESSURE WAS CENTERED NEAR GREAT BEND AT
18Z. THIS LOW WAS PART OF A COLD FRONT THAT EXTENDED FROM CENTRAL
MINNESOTA /AND AREAS FURTHER NORTH/...TO THE TEXAS PANHANDLE.
A STRONG UPPER LEVEL DISTURBANCE WAS ADVANCING NORTHEASTWARD ACROSS
SOUTHWEST NEBRASKA. THIS WILL BRING DESTABILIZING COOLER AIR IN THE
MID LEVELS TO THE REGION...CAUSING SHOWERS AND THUNDERSTORMS TO
DEVELOP ALONG THE FRONT. THESE ARE ALSO A BIG PART OF THE STORMS
ONGOING ACROSS WESTERN KANSAS AND WESTERN NEBRASKA. AS OF
1945Z...THE LEADING EDGE OF THIS CAN BE SEEN WELL ON WATER VAPOR
MOVING ACROSS WESTERN KANSAS.
TONIGHT...
THE FRONT WILL CONTINUE MOVING SOUTHEAST THIS EVENING. RUC SHOWING
SIGNIFICANT COLD ADVECTION ONGOING WITH THE APPROACHING
DISTURBANCE. DURING THE DAY...THE CONVERGENCE ALONG THE FRONT HAS HAD A
HARD TIME GETTING GOING AS THE WINDS HAVE VEERED AHEAD OF THE
FRONT. THIS HAS ADDED TO THE UNCERTAINTY OF WHEN CONVECTION IS
EXPECTED TO DEVELOP...BUT SHOULD BE BY 23Z. 0-6KM SHEAR IS MARGINAL
FOR ORGANIZED CONVECTION...WITH VALUES RANGING FROM 30-35 KNOTS.
THAT SAID...THERE IS ENOUGH INSTABILITY FOR SOME OF THE STORMS TO
BECOME SEVERE.
SUNDAY...THE FRONT SHOULD MAKE IT WELL INTO SOUTHEAST KANSAS. WITH
THE MAIN UPPER LEVEL SUPPORT FAR REMOVED FROM THE FRONT...ORGANIZED
SEVERE STORMS LOOK UNLIKELY AT THIS TIME...THOUGH SOME SCATTERED
STORMS EXPECTED.
MONDAY-SATURDAY...
HIGH PRESSURE WILL REMAIN ACROSS THE REGION THROUGH TUESDAY. THE
FRONT THAT JUST MOVED THROUGH WILL RETREAT NORTHWARD AS A WARM
FRONT. LEE CYCLOGENESIS TAKES PLACE AND BY WEDNESDAY...STRONG
SOUTHWESTERLY WINDS DEVELOP AGAIN AT THE SURFACE. THIS WILL ALL
RESULT IN A WARMING TREND IN THE MIDDLE AND LATTERN PORTION OF THE
WEEK. BY FRIDAY...A DEEP UPPER LEVEL TROUGH DEVELOPS OVER THE
PACIFIC COAST WITH RIDGING OVER THE SOUTHEAST. THIS WILL KEEP ALL
OF THE SIGNIFICANT PRECIPITATION WELL TO THE NORTH.
COOK
&&
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MAIN HAZARDS: WINDS AHEAD OF/BEHIND COLD FRONT...AND THUNDERSTORMS.
S-SWRLY GUSTS 25-35KT WILL PERSIST AHEAD OF FRONT THIS PM/EARLY
EVE. COLD FRONT SHOULD REACH RSL AROUND 20-21Z...SLN/HUT
01-02Z...AND ICT ~03-04Z. SCATTERED-BROKEN LINE OF THUNDERSTORMS
SHOULD DEVELOP ALONG THE FRONT LATE THIS PM/EVE WHICH COULD
PRODUCE OUTFLOW AHEAD OF ACTUAL FRONT. WIND GUSTS 40-50 KT AND
HAIL WOULD BE THE MAIN THREATS FROM THESE STORMS. WILL CARRY TEMPO
TS AT HUT/SLN SITES WITH HIGHEST CONFIDENCE OF STORMS AFFECTING
THOSE SITES...AND VCTS AT ICT. WIND SHIFT TO NW WITH SOME GUSTS
20-25 KT THIS EVE IN CENTRAL/SOUTH CENTRAL KS.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 58 79 57 80 / 50 20 10 0
HUTCHINSON 56 78 54 80 / 50 10 0 0
NEWTON 57 77 53 78 / 50 20 10 0
ELDORADO 59 78 54 79 / 40 20 10 0
WINFIELD-KWLD 61 79 58 80 / 40 30 20 10
RUSSELL 52 77 51 81 / 20 10 0 0
GREAT BEND 53 78 52 81 / 20 10 0 0
SALINA 56 78 51 80 / 50 10 0 0
MCPHERSON 57 77 52 79 / 50 10 0 0
COFFEYVILLE 65 81 59 79 / 30 40 30 10
CHANUTE 64 79 57 78 / 40 40 10 10
IOLA 64 78 57 77 / 30 40 10 10
PARSONS-KPPF 65 80 58 78 / 30 40 20 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
619 PM EDT SAT MAY 19 2012
.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR DRY AND UNSEASONABLY WARM WEATHER TO
CONTINUE INTO EARLY MONDAY. THE CHANCE OF SHOWERS AND THUNDERSTORMS
WILL RETURN AS A LOW PULLS MOISTURE INTO THE AREA FROM THE SOUTHEAST
AND A FRONTAL BOUNDARY APPROACHES FROM THE WEST.
&&
.NEAR TERM /THROUGH SUNDAY/...
MINOR CHANGES TO PREVIOUS FORECAST, INCREASED OVERNIGHT LOWS A
COUPLE OF DEGREES AND MADE TWEAKS TO CLOUD COVER.
PREVIOUS DISCUSSION...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE
EXTENDING FROM THE THE OHIO VALLEY INTO NEW ENGLAND WITH ITS
ASSOCIATED WEAK ANTI-CYCLONIC FLOW CENTERED ACROSS THE OHIO
VALLEY. MEANWHILE, A CLOSED LOW IS LOCATED OFF THE CAROLINA COAST.
AT THE SURFACE, A BROAD AREA OF HIGH PRESSURE IS CENTERED ACROSS
THE NORTHEAST, EXTENDING SOUTHWESTWARD INTO THE REGION.
THE RIDGE WILL SHIFT FURTHER NORTHEAST TONIGHT AND TOMORROW,
ALLOWING FOR DRY WEATHER TO CONTINUE WITH UNSEASONABLY WARM
HIGH TEMPS. SKIES WILL BE MOSTLY CLEAR THROUGH THIS
PERIOD, ASIDE FROM SOME HIGH CIRRUS SPILLING INTO THE AREA AHEAD
OF THE LOW TO THE SOUTHEAST. DESPITE TEMPS IN THE LOW TO MID 80S
FOR HIGHS, DRY AIR IN PLACE ALONG WITH NEAR CALM WINDS AND MOSTLY
CLEAR SKIES OVERNIGHT WILL ALLOW FOR ANOTHER NIGHT OF DECENT
RADIATIONAL COOLING. THUS, LOWS ARE A MAV/MET BLEND, DROPPING TO
NEAR NORMAL SEASONAL VALUES, IN THE LOW TO MID 50S ACROSS THE
AREA. THE GFS INDICATES 850 TEMPS AROUND 15C TOMORROW. THIS WILL
CONTRIBUTE TO YET ANOTHER DAY WITH HIGHS 10-15 DEGREES ABOVE
NORMAL, RANGING FROM THE MID 80S ACROSS THE LOWLANDS TO THE MID
70S ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
GFS/ECMWF INDICATE THE RIDGE AXIS BECOMING PINCHED OFF SUNDAY NIGHT
INTO MONDAY AS THE UPPER LOW MOVES INTO VIRGINIA AND A TROUGH MOVES
INTO THE UPPER MIDWEST. THE CLOSED LOW WILL SERVE TO DRAW MOISTURE
INTO THE AREA FROM THE ATLANTIC. WITH THIS IN MIND, THE CHANCE OF
SHOWERS BEGINS SOUTHEAST OF PITTSBURGH ON MONDAY MORNING. IN
ASSOCIATION WITH THE TROUGH, A FRONTAL BOUNDARY WILL CROSS THE OHIO
VALLEY ON MONDAY AFTERNOON. INCREASING MOISTURE AND INSTABILITY
AHEAD OF THIS FEATURE WILL LEAD TO THE CHANCE OF SHOWERS AND
THUNDERSTORMS MONDAY AFTERNOON THROUGH THE EVENING. INCREASED
CLOUD COVERAGE AND COOLER TEMPS ALOFT ASSOCIATED WITH THE LOW
APPROACHING FROM THE SOUTHEAST WILL ALLOW FOR A SLIGHT COOLER DAY
ON MONDAY, WITH HIGH TEMPS AT 5 TO 10 DEGREES ABOVE NORMAL,
RANGING FROM THE LOWER 80S ACROSS EASTERN OHIO TO NEAR 70 ACROSS
THE EASTERN RIDGES.
SOME MODEL UNCERTAINTY ENTERS THE FORECAST IN REGARDS TO THE TROUGH
MOVING INTO THE AREA FROM THE UPPER MIDWEST. ECMWF/NAM SOLUTIONS
MERGE THE UPPER LOW TO THE SOUTHEAST WITH THIS FEATURE INTO A MORE
AMPLIFIED TROUGH ACROSS THE AREA. MEANWHILE, THE GFS MOVES THE UPPER
LOW UP THE EAST COAST AND BRINGS A WEAKER TROUGH ACROSS THE AREA. WITH
THIS UNCERTAINTY IN MIND AND THE SLOW PASSAGE OF A FRONTAL
BOUNDARY, FORECAST IS A BLEND OF THE SOLUTIONS, CONTINUING A
CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY NIGHT INTO TUESDAY.
WITH INCREASED CLOUD COVERAGE WITH SHOWERS AND THUNDERSTORMS,
HIGHS ON TUESDAY WILL BE SLIGHTLY COOLER IN COMPARISON TO THE
WEEKEND AND MONDAY, ALTHOUGH STILL AROUND 5 DEGREES ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
12Z GFS/00Z ECMWF HAVE DIFFERENT DEPICTIONS IN THE EXTENDED...AND
THEREFORE CONFIDENCE IS BELOW AVERAGE. BOTH MODELS SHOW GENERAL
AGREEMENT THAT THERE WILL BE A NEARLY STATIONARY UPPER LEVEL
LOW/TROUGH NEAR THE CAROLINAS. HOWEVER...MULTIPLE RUNS OF THE GFS
KEEPS THIS FEATURE OVER THE ATLANTIC OCEAN WITH JUST SOME CLOUDS
LOCALLY...WHILE THE ECMWF HAS THE FEATURE INLAND ALONG THE EAST
COAST AND SPREADS RAIN AS FAR WEST AS WEST VIRGINIA AND EASTERN
OHIO. WITH NAEFS AND ECMWF ENSEMBLE KEEPING THE PATTERN A LITTLE
DRIER...HAVE ALSO STUCK WITH A DRIER FORECAST. IF THIS HOLDS...AND
THE GFS FORECAST VERIFIES...THIS PERIOD WILL BE QUITE WARM. GFS
BIAS-CORRECTED GRIDS AND NAEFS METEOGRAMS SUGGEST THAT 90 DEGREES IS
NOT OUT OF THE QUESTION FOR THE START OF THE MEMORIAL DAY WEEKEND.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL KEEP SKIES MOSTLY CLEAR AND WINDS BELOW 10 KTS
FOR NEXT 24 HOURS. THE ONLY CLOUDS THAT ARE EXPECTED WILL BE WITH
BLOWOFF FROM POSSIBLE TROPICAL SYSTEM OFF CAROLINAS.
.OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
SUNDAY NIGHT SHOULD REMAIN DRY BEFORE COLD FRONT APPROACHES FROM THE
WEST ON MONDAY. CONVECTION WILL ALSO INCREASE FROM THE EAST. SLOW
MOVING FRONT WILL BRING A CONTINUED CHANCE FOR SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY. PRECIPITATION SHOULD THEN SHIFT
EAST OF THE AREA BY WEDNESDAY NIGHT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
342 PM EDT SAT MAY 19 2012
.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR DRY AND UNSEASONABLY WARM WEATHER TO
CONTINUE INTO EARLY MONDAY. THE CHANCE OF SHOWERS AND THUNDERSTORMS
WILL RETURN AS A LOW PULLS MOISTURE INTO THE AREA FROM THE SOUTHEAST
AND A FRONTAL BOUNDARY APPROACHES FROM THE WEST.
&&
.NEAR TERM /THROUGH SUNDAY/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE
EXTENDING FROM THE THE OHIO VALLEY INTO NEW ENGLAND WITH ITS
ASSOCIATED WEAK ANTI-CYCLONIC FLOW CENTERED ACROSS THE OHIO
VALLEY. MEANWHILE, A CLOSED LOW IS LOCATED OFF THE CAROLINA COAST.
AT THE SURFACE, A BROAD AREA OF HIGH PRESSURE IS CENTERED ACROSS
THE NORTHEAST, EXTENDING SOUTHWESTWARD INTO THE REGION.
THE RIDGE WILL SHIFT FURTHER NORTHEAST TONIGHT AND TOMORROW,
ALLOWING FOR DRY WEATHER TO CONTINUE WITH UNSEASONABLY WARM
HIGH TEMPS. SKIES WILL BE MOSTLY CLEAR THROUGH THIS
PERIOD, ASIDE FROM SOME HIGH CIRRUS SPILLING INTO THE AREA AHEAD
OF THE LOW TO THE SOUTHEAST. DESPITE TEMPS IN THE LOW TO MID 80S
FOR HIGHS, DRY AIR IN PLACE ALONG WITH NEAR CALM WINDS AND MOSTLY
CLEAR SKIES OVERNIGHT WILL ALLOW FOR ANOTHER NIGHT OF DECENT
RADIATIONAL COOLING. THUS, LOWS ARE A MAV/MET BLEND, DROPPING TO
NEAR NORMAL SEASONAL VALUES, IN THE LOW TO MID 50S ACROSS THE
AREA. THE GFS INDICATES 850 TEMPS AROUND 15C TOMORROW. THIS WILL
CONTRIBUTE TO YET ANOTHER DAY WITH HIGHS 10-15 DEGREES ABOVE
NORMAL, RANGING FROM THE MID 80S ACROSS THE LOWLANDS TO THE MID
70S ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
GFS/ECMWF INDICATE THE RIDGE AXIS BECOMING PINCHED OFF SUNDAY NIGHT
INTO MONDAY AS THE UPPER LOW MOVES INTO VIRGINIA AND A TROUGH MOVES
INTO THE UPPER MIDWEST. THE CLOSED LOW WILL SERVE TO DRAW MOISTURE
INTO THE AREA FROM THE ATLANTIC. WITH THIS IN MIND, THE CHANCE OF
SHOWERS BEGINS SOUTHEAST OF PITTSBURGH ON MONDAY MORNING. IN
ASSOCIATION WITH THE TROUGH, A FRONTAL BOUNDARY WILL CROSS THE OHIO
VALLEY ON MONDAY AFTERNOON. INCREASING MOISTURE AND INSTABILITY
AHEAD OF THIS FEATURE WILL LEAD TO THE CHANCE OF SHOWERS AND
THUNDERSTORMS MONDAY AFTERNOON THROUGH THE EVENING. INCREASED
CLOUD COVERAGE AND COOLER TEMPS ALOFT ASSOCIATED WITH THE LOW
APPROACHING FROM THE SOUTHEAST WILL ALLOW FOR A SLIGHT COOLER DAY
ON MONDAY, WITH HIGH TEMPS AT 5 TO 10 DEGREES ABOVE NORMAL,
RANGING FROM THE LOWER 80S ACROSS EASTERN OHIO TO NEAR 70 ACROSS
THE EASTERN RIDGES.
SOME MODEL UNCERTAINTY ENTERS THE FORECAST IN REGARDS TO THE TROUGH
MOVING INTO THE AREA FROM THE UPPER MIDWEST. ECMWF/NAM SOLUTIONS
MERGE THE UPPER LOW TO THE SOUTHEAST WITH THIS FEATURE INTO A MORE
AMPLIFIED TROUGH ACROSS THE AREA. MEANWHILE, THE GFS MOVES THE UPPER
LOW UP THE EAST COAST AND BRINGS A WEAKER TROUGH ACROSS THE AREA. WITH
THIS UNCERTAINTY IN MIND AND THE SLOW PASSAGE OF A FRONTAL
BOUNDARY, FORECAST IS A BLEND OF THE SOLUTIONS, CONTINUING A
CHANCE OF SHOWERS AND THUNDERSTORMS MONDAY NIGHT INTO TUESDAY.
WITH INCREASED CLOUD COVERAGE WITH SHOWERS AND THUNDERSTORMS,
HIGHS ON TUESDAY WILL BE SLIGHTLY COOLER IN COMPARISON TO THE
WEEKEND AND MONDAY, ALTHOUGH STILL AROUND 5 DEGREES ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
12Z GFS/00Z ECMWF HAVE DIFFERENT DEPICTIONS IN THE EXTENDED...AND
THEREFORE CONFIDENCE IS BELOW AVERAGE. BOTH MODELS SHOW GENERAL
AGREEMENT THAT THERE WILL BE A NEARLY STATIONARY UPPER LEVEL
LOW/TROUGH NEAR THE CAROLINAS. HOWEVER...MULTIPLE RUNS OF THE GFS
KEEPS THIS FEATURE OVER THE ATLANTIC OCEAN WITH JUST SOME CLOUDS
LOCALLY...WHILE THE ECMWF HAS THE FEATURE INLAND ALONG THE EAST
COAST AND SPREADS RAIN AS FAR WEST AS WEST VIRGINIA AND EASTERN
OHIO. WITH NAEFS AND ECMWF ENSEMBLE KEEPING THE PATTERN A LITTLE
DRIER...HAVE ALSO STUCK WITH A DRIER FORECAST. IF THIS HOLDS...AND
THE GFS FORECAST VERIFIES...THIS PERIOD WILL BE QUITE WARM. GFS
BIAS-CORRECTED GRIDS AND NAEFS METEOGRAMS SUGGEST THAT 90 DEGREES IS
NOT OUT OF THE QUESTION FOR THE START OF THE MEMORIAL DAY WEEKEND.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL KEEP SKIES MOSTLY CLEAR AND WINDS BELOW 10 KTS
FOR NEXT 24 HOURS. THE ONLY CLOUDS THAT ARE EXPECTED WILL BE WITH
BLOWOFF FROM POSSIBLE TROPICAL SYSTEM OFF CAROLINAS.
.OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
SUNDAY NIGHT SHOULD REMAIN DRY BEFORE COLD FRONT APPROACHES FROM THE
WEST ON MONDAY. CONVECTION WILL ALSO INCREASE FROM THE EAST. SLOW
MOVING FRONT WILL BRING A CONTINUED CHANCE FOR SHOWERS AND
THUNDERSTORMS THROUGH WEDNESDAY. PRECIPITATION SHOULD THEN SHIFT
EAST OF THE AREA BY WEDNESDAY NIGHT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
159 PM EDT SAT MAY 19 2012
.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR DRY AND UNSEASONABLY WARM WEATHER TO
CONTINUE INTO EARLY MONDAY. THE CHANCE OF SHOWERS AND THUNDERSTORMS
WILL RETURN AS A LOW PULLS MOISTURE INTO THE AREA FROM THE SOUTHEAST
AND A FRONTAL BOUNDARY APPROACHES FROM THE WEST.
&&
.NEAR TERM /THROUGH SUNDAY/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED WITH MINOR
CHANGES TO THE GOING FORECAST TO ADJUST SKY GRIDS AS THIN CIRRUS
CONTINUES TO FILTER INTO THE AREA WELL AHEAD OF A LOW CENTER OFF THE
CAROLINA COAST.
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A 500MB RIDGE
EXTENDING FROM THE THE OHIO VALLEY INTO NEW ENGLAND WITH ITS
ASSOCIATED WEAK ANTI-CYCLONIC FLOW CENTERED ACROSS THE OHIO
VALLEY. MEANWHILE, A CLOSED LOW IS LOCATED OFF THE CAROLINA COAST.
AT THE SURFACE, A BROAD AREA OF HIGH PRESSURE IS CENTERED ACROSS
THE NORTHEAST, EXTENDING SOUTHWESTWARD INTO THE REGION.
THE RIDGE WILL SHIFT FURTHER NORTHEAST TONIGHT AND TOMORROW,
ALLOWING FOR DRY AND UNSEASONABLY WARM WEATHER TO CONTINUE. SKIES
WILL BE MOSTLY CLEAR THROUGH THIS PERIOD, ASIDE FROM SOME HIGH
CIRRUS SPILLING INTO THE AREA AHEAD OF THE LOW TO THE SOUTHEAST.
DESPITE TEMPS IN THE LOW TO MID 80S FOR HIGHS, DRY AIR IN PLACE
ALONG WITH NEAR CALM WINDS AND MOSTLY CLEAR SKIES OVERNIGHT WILL
ALLOW FOR ANOTHER NIGHT OF DECENT RADIATIONAL COOLING. THUS, LOWS
ARE A MAV/MET BLEND, DROPPING TO NEAR NORMAL SEASONAL VALUES, IN THE
LOW TO MID 50S ACROSS THE AREA. THE GFS INDICATES 850 TEMPS AROUND
15C TOMORROW. THIS WILL CONTRIBUTE TO YET ANOTHER DAY WITH HIGHS 10-15
DEGREES ABOVE NORMAL, RANGING FROM THE MID 80S ACROSS THE LOWLANDS
TO THE MID 70S ACROSS THE EASTERN RIDGES.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
MODELS CONTINUE TO STRUGGLE WITH THE INTERACTION OF THE CUTOFF LOW
OVER THE SOUTHEAST THROUGH AND THE TROUGH ACROSS THE UPPER
MIDWEST. AT THIS POINT...THE 500HPA RIDGE SHOULD BEGIN TO PINCH
OFF SUNDAY NIGHT AND AS IT TRANSFERS TO THE COAST THE UPSTREAM
TROUGH ACTUALLY HELPS TO BRING THE CUTOFF LOW FURTHER WEST.
THE ECMWF/GFS CONTINUE TO BE FAVORED THROUGH THIS TIME PERIOD AS
THE NAM KEEPS THE LOW SLIGHTLY FARTHER SOUTH. GRADUALLY INCREASE
PRECIP CHANCES FROM BOTH THE EAST AND WEST MONDAY AS WE ARE
SQUEEZED BETWEEN THE COLD FRONT AND THE CUTOFF LOW AND MAINTAIN
THOSE CHANCES THROUGH TUESDAY.
TEMPERATURES SHOULD CONTINUE TO REMAIN 10 DEGREES ABOVE NORMAL
SUNDAY AND 5-10 DEGREES ABOVE NORMAL MONDAY DESPITE INCREASING
CLOUD COVER AND PRECIPITATION CHANCES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
MODELS CONTINUE TO DISAGREE SOMEWHAT WITH REGARD TO TIMING OF THE
FRONT APPROACHING FROM THE WEST AND ON THE EXTENT OF
RETROGRESSION OF EAST COAST LOW EARLY NEXT WEEK.
STAYED CLOSE TO HPC GUIDANCE WHICH STILL LEANS TOWARD FASTER GFS
TIMING WITH THE FRONT AND PUSHES THE MAIN AREA OF PRECIPITATION
EAST OF THE REGION BY WEDNESDAY NIGHT.
A WEAK SURFACE RIDGE SHOULD PROVIDE GENERALLY DRY WEATHER FOR
THURSDAY INTO FRIDAY FOR MUCH OF THE FORECAST AREA. MOIST SOUTHEAST
FLOW FROM THE ATLANTIC DEPICTED BY THE ECMWF COULD MAINTAIN
SCATTERED PRECIPITATION OVER THE RIDGES ON THURSDAY NIGHT AND
FRIDAY.
TEMPERATURES ARE FORECAST TO RANGE FROM 5 TO 10 DEGREES ABOVE NORMAL
THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS AND LIGHT EAST WINDS WILL PREVAIL THROUGH THE TAF
PERIOD AS A SURFACE RIDGE HOLDS ALONG THE APPALACHIANS.
.OUTLOOK...SUNDAY THROUGH WEDNESDAY...
THE SURFACE RIDGE WILL MAINTAIN VFR WEATHER THROUGH SUNDAY NIGHT.
A FRONT WILL APPROACH FROM THE WEST LATE MONDAY WHILE A LOW
PRESSURE SYSTEM MOVES INLAND FROM THE CAROLINA COAST. MOISTURE
WILL INCREASE ACROSS THE REGION BY EARLY MONDAY ALONG WITH THE
POTENTIAL FOR RESTRICTIONS IN SHOWERS AND THUNDERSTORMS. SCATTERED
PRECIPITATION SHOULD PERSIST THROUGH WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
133 PM EDT SAT MAY 19 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 508 AM EDT SAT MAY 19 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER THE
GREAT LAKES DOWNSTREAM OF TROF IN THE ROCKIES. CWA IS IN THE WARM
SECTOR E OF SFC-H85 TROF/COLD FNT AND S OF WARM FNT OVER NRN LK SUP/
ADJOINING ONTARIO. WITH DRYNESS SHOWN ON LOCAL 00Z RAOBS /H925 DEWPT
DEPRESSIONS ARE 15 TO 25C ON THE MPX/GRB RAOBS AND THE H85 DEWPT
DEPRESSION AT GRB WAS 49C/...SKIES ARE MOCLR OVER UPR MI. DESPITE
THE CLEAR SKIES/DRY AIR AND LOCAL DECOUPLING... TEMPS ARE WELL ABV
NORMAL WITH STEADY SW FLOW AT H925 LIMITING THE OVERALL DIURNAL TEMP
DROP. SOME SHRA/TS DID IMPACT MUCH OF MN THIS PAST EVNG DESPITE
FAIRLY DRY AIR.AS SHRTWV LIFTED NNEWD WELL E OF THE MAIN TROF TO THE
W...BUT THESE ARE TENDING TO WEAKEN AND STAY W OF EVEN LK SUP. MORE
WIDESPREAD SHRA/TS ARE LOCATED IN THE PLAINS CLOSER TO H85 COLD FNT.
MAIN FCST CONCERNS TDAY ARE FOCUSED ON FIRE WX. FOCUS FOR TNGT THRU
SUN SHIFTS TO SHRA/TS CHCS ASSOCIATED WITH SLOWLY APRCHG UPR TROF/
COLD FNT.
TDAY...CWA WL REMAIN UNDER WARM SW FLOW AS COLD FNT TO THE W SLIDES
EWD THRU MN. ALTHOUGH H85 TEMPS ARE FCST TO AVG ABOUT A DEGREE LOWER
THAN YDAY...VERY DEEP MIXING SHOWN ON THE 00Z MPX RAOB SHOULD
SUPPORT MAX TEMPS NEARLY SIMILAR TO WHAT OCCURRED ON FRI PER
UPSTREAM OBSVD SFC HI TEMPS...WITH SOME PLACES OVER THE W HALF
SEEING THE MERCURY REACH 90. GOING FCST SHOWING THESE HIER TEMPS IN
THE DOWNSLOPE AREAS FM ONTONAGON TO BARAGA LOOK ON TRACK. AREAS OVER
THE E HALF SHOULD SEE SOME MODERATION OFF LK MI. SOME LK MODERATION
MAY SLIP A BIT FARTHER W INTO THE CNTRL IF FCST BACKING WINDS TO
MORE DUE S DRAGS THE LK MI MODERATION INTO THAT AREA. SEE FIRE WX
SECTION BLO FOR A DISCUSSION OF FIRE WX CONCERNS.
TNGT...WITH BLDG UPR RDG FCST OVER THE ERN GRT LKS...OPTED TO FOLLOW
THE SOMEWHAT SLOWER 12Z ECMWF/00Z CNDN MODELS FOR THE TIMING OF THE
COLD FNT...ESPECIALLY SINCE A SHRTWV LIFTING NEWD OUT OF THE ROCKIES
WL INDUCE A LOW PRES TO DVLP ON THIS BNDRY OVER THE PLAINS TDAY.
THIS LO IS FCST TO MOVE INTO MN BY 12Z SUN. THE 00Z NAM HAS TRENDED
IN THIS DIRECTION AS WELL. IN FACT...THE 12Z ECMWF/0Z CNDN MODELS
INDICATE THE BULK OF ANY PCPN WL BE ON THE COLD SIDE OF THE FNT
AND STAY W OF IWD THRU 12Z. THIS FCST IS REASONABLE CONSIDERING THE
DRYNESS OF THE WARM SECTOR AIRMASS AND FCST DEEP LYR QVECTOR CNVGC
BEING FOCUSED UNDER THE SHARPER DPVA ASSOCIATED WITH THE SHRTWV ON
THE COLD SIDE OF THE FNT IN MN EVEN AS LATE AS 12Z SUN. STEADY SW
FLOW IN THE WARM SECTOR SHOULD ONCE AGAIN LIMIT THE DIURNAL FALL OF
TEMP...SO MINS WL BE WELL ABV NORMAL AGAIN.
SUN...SINCE THE FAVORED 12Z ECMWF/00Z CNDN MODELS SHOW BULK OF DEEP
LYR QVECTOR CNVGC SHIFTING NEWD THRU WRN LK SUP TOWARD ONTARIO...
SUSPECT THE HIER POPS WL BE OVER THE NW CWA...WITH PCPN TENDING TO
DIMINISH AS THE FNT SHIFTS TO THE E INTO THE CENTRAL CWA BY LATE
AFTN. HOWEVER...DAYTIME HEATING MAY OFFSET THE LOSS OF BEST
DYNAMICS...ESPECIALLY SINCE THE CNDN MODEL SHOWS HIER H85 DWPTS UP
TO 12C SURGING NEWD RIGHT ALONG THE FNT. HOWEVER...THIS SOMEWHAT
HIER MSTR IS STILL RELATIVELY LO COMPARED TO H85 TEMPS FCST ARND
16C. SO THE LLVLS WL STILL BE RATHER DRY PER THE MODEL FCST
SDNGS...LIMITING DESTABILIZATION. OPTED TO GO WITH LIKELY POPS OVER
THE NW CWA...DIMINISHING TO CHC FARTHER TO THE E. RAISED FCST HI
TEMPS WELL INTO THE 80S OVER THE E AND CNTRL AWAY FM LK MI
MODERATION TO ACCOUNT FOR SLOWER ARRIVAL OF COLD FNT.
SUN NGT...EXPECT COLD FNT TO PUSH THRU THE REST OF THE CWA
ACCOMPANIED BY CHC POPS AS MAIN SHRTWV/SHARPEST DEEP LYR QVECTOR
CNVGC EXITS TO THE NE AND ANY HELP FM DIURNAL HEATING WANES. SINCE
GUIDANCE HINTS AT THE ARPCH OF A SECOND SHRTWV FM MN...MAINTAINED
THE CHC POPS HANGING WELL BACK BEHIND THE COLD FNT AS HINTED AT BY
00Z NAM/12Z ECWMF AND SHOWN IN PREVIOUS FCST DESPITE MID LVL DRYING
IN THE WAKE OF THE INITIAL DISTURBANCE. IF THIS TRAILING SHRTWV IS
WEAKER...THE DRYING BEHIND THE FIRST STRONGER SHRTWV MAY END THE
POPS FASTER THAN FCST AS FCST BY THE 00Z CNDN. THE ARRIVAL OF H85
TEMPS AOB 5C OVER THE W BY 12Z MON WL BRING A RETURN OF MORE
SEASONABLE TEMPS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 508 AM EDT SAT MAY 19 2012
A SLOWLY TRANSITIONING WX PATTERN...WITH MUCH OF THE PERIOD
CONTINUING TO BE DOMINATED BY SOUTHERLY WINDS.
INITIALLY WE WILL HAVE THE EXITING COLD FRONT TO OUR EAST...AND HIGH
PRESSURE PUSHING IN FROM THE CENTRAL AND N PLAINS. AS A
RESULT...EXPECT TEMPS TO BE 10 TO 15 DEGREES COOLER THAN SUNDAY.
850MB TEMPS WILL BE 4-5C. WITH THE COOL TEMPS WILL COME DRY
AIR...WITH LOWER DEWPOINTS MONDAY AFTERNOON INTO THE MID 30S OVER
THE W HALF. WOULD NOT BE COMPLETELY SHOCKED TO SEE VALUES CLOSER TO
30F...WHICH WOULD GIVE RH VALUES NEAR 25 PERCENT.
THE SFC HIGH WILL BE DIRECTLY OVERHEAD TUESDAY MORNING...BEFORE
SLIDING E. EXPECT THE RETURN OF S WINDS...AND A LITTLE BETTER
MOISTURE. WE WILL SEE STRONGER SOUTHERLY WINDS RETURN BRIEFLY
WEDNESDAY AFTERNOON. ADJUSTED MAX TEMPS UP OVER THE TRADITIONAL
DOWNSLOPE AREAS NEAR LAKE SUPERIOR...WITH 850MB TEMPS RISING TO 11
TO 15C WITH THE COOLEST VALUES EAST.
WENT ABOVE CONSENSUS FOR HIGH TEMPS THURSDAY...ONCE AGAIN WITH A
MORE SIGNIFICANT INCREASE TO DOWNSLOPE AREAS. 850MB WINDS PEG OUT
BETWEEN 45 AND 60KTS...AND TEMPS JUMP UP TO 15-18C. THE 19/00Z GFS
IS ONE OF THE COOLEST SOLUTIONS.
WILL BE INTERESTING HOW THE END OF THE WORK WEEK PANS OUT...AND IF
THE FRONTAL BOUNDARY SETS UP AND STALLS OVER THE W CWA LIKE THE
19/00Z ECMWF...OR BLOWS THROUGH OUR AREA THURSDAY NIGHT BEFORE
STALLING OVER LOWER MI FRIDAY INTO SATURDAY. WILL NOT GET TOO FANCY
WITH THE FORECAST THAT FAR OUT...AND WILL KEEP THE SLIGHT CHANCE/LOW
CHANCE POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 133 PM EDT SAT MAY 19 2012
EXPECT VFR CONDITIONS FOR MOST OF THE FORECAST PERIOD AT THE TAF
SITES. A COLD FRONT APPROACHING THE AREA LATE TONIGHT INTO
TOMORROW WILL BRING INCREASING CLOUD COVER AND A CHANCE OF SHOWERS
AND POSSIBLY A THUNDERSTORM TO KIWD/KCMX. STILL SOME UNCERTAINTY
ON INTENSITY OF THE SHOWERS...SO HAVE LEFT VSBYS AT VFR. ONE FINAL
ITEM OF NOTE IS THE POTENTIAL FOR CIGS TO DROP AT KIWD/KCMX LATE IN
THE PERIOD IF FOG DEVELOPS OVER WRN LK SUPERIOR LATE TONIGHT INTO
TOMORROW MORNING. WINDS TURNING TO THE WNW BEHIND THE FRONT WOULD
PUSH THE FOG ONSHORE AND EFFECT BOTH SITES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 508 AM EDT SAT MAY 19 2012
WINDS SHOULD REMAIN BELOW 30KTS THROUGH THE PERIOD. LOW PRESSURE
STRETCHING FROM SOUTHWESTERN QUEBEC TO NEBRASKA WILL SHIFT
NORTHEASTWARD...FILLING SLIGHTLY AS IT CROSSES LAKE SUPERIOR SUNDAY
INTO SUNDAY EVENING. BEHIND THIS FEATURE...HIGH PRESSURE WILL BUILD
ACROSS THE UPPER GREAT LAKES MONDAY AND MONDAY NIGHT. EXPECT THE
HIGH TO SLOWLY EXIT NORTHEASTWARD THROUGH MID WEEK...IN RESPONSE TO
A STRONGER LOW NEARING FROM SOUTH CENTRAL CANADA THROUGH THE CENTRAL
PLAINS. EXPECT THE LOW TO OUR WEST TO MOVE OVER ONTARIO ON
THURSDAY...BEFORE EDGING ACROSS LAKE SUPERIOR THURSDAY NIGHT.
&&
.FIRE WEATHER...
ISSUED AT 508 AM EDT SAT MAY 19 2012
AFTER AN OVERNGT OF RELATIVELY POOR RH RECOVERY...EXPECT ANOTHER DAY
OF AT LEAST NEAR CRITICAL FIRE WX PARAMETERS. MAX TEMPS THIS AFTN
WILL BE SIMILAR TO WHAT WAS OBSVD YDAY...BUT DEEPER MIXING SHOWN
ESPECIALLY ON THE 00Z MPX RAOB MIGHT TAP INTO LOWER DEWPTS. IN
FACT...SFC DEWPTS WERE AS LO AS 35 TO 45 UPSTREAM YDAY AFTN IN WRN
WI/SRN MN. BLENDED MIXED DEWPT TOOL VALUES WITH THE PREVIOUS FCST
DEWPTS TO COME UP WITH READINGS DIPPING AS LO AS 43 OR SO. WITH
WINDS ALOFT TDAY ALSO NEARLY SIMILAR TO YDAY AND DEEP MIXING RELATED
TO DAYTIME HEATING... SUSTAINED WINDS AS HI AS 10 TO 20 MPH WITH
GUSTS TO 30 MPH AT THE MORE EXPOSED LOCATIONS ARE LIKELY. OPTED TO
ISSUE RFW FOR AN ARK FROM IWD/ONTONAGON TO BARAGA/MQT
COUNTIES...AREAS THAT SAW THE POOREST RH RECOVERY EARLY THIS MRNG
AND WHERE STRONGER WINDS/HIER DAYTIME HI TEMPS ARE MOST LIKELY. WL
ISSUE RFD FOR THE OTHER COUNTIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
RED FLAG WARNING UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR
MIZ002-004-005-009-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...SRF
MARINE...KF
FIRE WEATHER...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
753 AM EDT SAT MAY 19 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 508 AM EDT SAT MAY 19 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER THE
GREAT LAKES DOWNSTREAM OF TROF IN THE ROCKIES. CWA IS IN THE WARM
SECTOR E OF SFC-H85 TROF/COLD FNT AND S OF WARM FNT OVER NRN LK SUP/
ADJOINING ONTARIO. WITH DRYNESS SHOWN ON LOCAL 00Z RAOBS /H925 DEWPT
DEPRESSIONS ARE 15 TO 25C ON THE MPX/GRB RAOBS AND THE H85 DEWPT
DEPRESSION AT GRB WAS 49C/...SKIES ARE MOCLR OVER UPR MI. DESPITE
THE CLEAR SKIES/DRY AIR AND LOCAL DECOUPLING... TEMPS ARE WELL ABV
NORMAL WITH STEADY SW FLOW AT H925 LIMITING THE OVERALL DIURNAL TEMP
DROP. SOME SHRA/TS DID IMPACT MUCH OF MN THIS PAST EVNG DESPITE
FAIRLY DRY AIR.AS SHRTWV LIFTED NNEWD WELL E OF THE MAIN TROF TO THE
W...BUT THESE ARE TENDING TO WEAKEN AND STAY W OF EVEN LK SUP. MORE
WIDESPREAD SHRA/TS ARE LOCATED IN THE PLAINS CLOSER TO H85 COLD FNT.
MAIN FCST CONCERNS TDAY ARE FOCUSED ON FIRE WX. FOCUS FOR TNGT THRU
SUN SHIFTS TO SHRA/TS CHCS ASSOCIATED WITH SLOWLY APRCHG UPR TROF/
COLD FNT.
TDAY...CWA WL REMAIN UNDER WARM SW FLOW AS COLD FNT TO THE W SLIDES
EWD THRU MN. ALTHOUGH H85 TEMPS ARE FCST TO AVG ABOUT A DEGREE LOWER
THAN YDAY...VERY DEEP MIXING SHOWN ON THE 00Z MPX RAOB SHOULD
SUPPORT MAX TEMPS NEARLY SIMILAR TO WHAT OCCURRED ON FRI PER
UPSTREAM OBSVD SFC HI TEMPS...WITH SOME PLACES OVER THE W HALF
SEEING THE MERCURY REACH 90. GOING FCST SHOWING THESE HIER TEMPS IN
THE DOWNSLOPE AREAS FM ONTONAGON TO BARAGA LOOK ON TRACK. AREAS OVER
THE E HALF SHOULD SEE SOME MODERATION OFF LK MI. SOME LK MODERATION
MAY SLIP A BIT FARTHER W INTO THE CNTRL IF FCST BACKING WINDS TO
MORE DUE S DRAGS THE LK MI MODERATION INTO THAT AREA. SEE FIRE WX
SECTION BLO FOR A DISCUSSION OF FIRE WX CONCERNS.
TNGT...WITH BLDG UPR RDG FCST OVER THE ERN GRT LKS...OPTED TO FOLLOW
THE SOMEWHAT SLOWER 12Z ECMWF/00Z CNDN MODELS FOR THE TIMING OF THE
COLD FNT...ESPECIALLY SINCE A SHRTWV LIFTING NEWD OUT OF THE ROCKIES
WL INDUCE A LOW PRES TO DVLP ON THIS BNDRY OVER THE PLAINS TDAY.
THIS LO IS FCST TO MOVE INTO MN BY 12Z SUN. THE 00Z NAM HAS TRENDED
IN THIS DIRECTION AS WELL. IN FACT...THE 12Z ECMWF/0Z CNDN MODELS
INDICATE THE BULK OF ANY PCPN WL BE ON THE COLD SIDE OF THE FNT
AND STAY W OF IWD THRU 12Z. THIS FCST IS REASONABLE CONSIDERING THE
DRYNESS OF THE WARM SECTOR AIRMASS AND FCST DEEP LYR QVECTOR CNVGC
BEING FOCUSED UNDER THE SHARPER DPVA ASSOCIATED WITH THE SHRTWV ON
THE COLD SIDE OF THE FNT IN MN EVEN AS LATE AS 12Z SUN. STEADY SW
FLOW IN THE WARM SECTOR SHOULD ONCE AGAIN LIMIT THE DIURNAL FALL OF
TEMP...SO MINS WL BE WELL ABV NORMAL AGAIN.
SUN...SINCE THE FAVORED 12Z ECMWF/00Z CNDN MODELS SHOW BULK OF DEEP
LYR QVECTOR CNVGC SHIFTING NEWD THRU WRN LK SUP TOWARD ONTARIO...
SUSPECT THE HIER POPS WL BE OVER THE NW CWA...WITH PCPN TENDING TO
DIMINISH AS THE FNT SHIFTS TO THE E INTO THE CENTRAL CWA BY LATE
AFTN. HOWEVER...DAYTIME HEATING MAY OFFSET THE LOSS OF BEST
DYNAMICS...ESPECIALLY SINCE THE CNDN MODEL SHOWS HIER H85 DWPTS UP
TO 12C SURGING NEWD RIGHT ALONG THE FNT. HOWEVER...THIS SOMEWHAT
HIER MSTR IS STILL RELATIVELY LO COMPARED TO H85 TEMPS FCST ARND
16C. SO THE LLVLS WL STILL BE RATHER DRY PER THE MODEL FCST
SDNGS...LIMITING DESTABILIZATION. OPTED TO GO WITH LIKELY POPS OVER
THE NW CWA...DIMINISHING TO CHC FARTHER TO THE E. RAISED FCST HI
TEMPS WELL INTO THE 80S OVER THE E AND CNTRL AWAY FM LK MI
MODERATION TO ACCOUNT FOR SLOWER ARRIVAL OF COLD FNT.
SUN NGT...EXPECT COLD FNT TO PUSH THRU THE REST OF THE CWA
ACCOMPANIED BY CHC POPS AS MAIN SHRTWV/SHARPEST DEEP LYR QVECTOR
CNVGC EXITS TO THE NE AND ANY HELP FM DIURNAL HEATING WANES. SINCE
GUIDANCE HINTS AT THE ARPCH OF A SECOND SHRTWV FM MN...MAINTAINED
THE CHC POPS HANGING WELL BACK BEHIND THE COLD FNT AS HINTED AT BY
00Z NAM/12Z ECWMF AND SHOWN IN PREVIOUS FCST DESPITE MID LVL DRYING
IN THE WAKE OF THE INITIAL DISTURBANCE. IF THIS TRAILING SHRTWV IS
WEAKER...THE DRYING BEHIND THE FIRST STRONGER SHRTWV MAY END THE
POPS FASTER THAN FCST AS FCST BY THE 00Z CNDN. THE ARRIVAL OF H85
TEMPS AOB 5C OVER THE W BY 12Z MON WL BRING A RETURN OF MORE
SEASONABLE TEMPS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 508 AM EDT SAT MAY 19 2012
A SLOWLY TRANSITIONING WX PATTERN...WITH MUCH OF THE PERIOD
CONTINUING TO BE DOMINATED BY SOUTHERLY WINDS.
INITIALLY WE WILL HAVE THE EXITING COLD FRONT TO OUR EAST...AND HIGH
PRESSURE PUSHING IN FROM THE CENTRAL AND N PLAINS. AS A
RESULT...EXPECT TEMPS TO BE 10 TO 15 DEGREES COOLER THAN SUNDAY.
850MB TEMPS WILL BE 4-5C. WITH THE COOL TEMPS WILL COME DRY
AIR...WITH LOWER DEWPOINTS MONDAY AFTERNOON INTO THE MID 30S OVER
THE W HALF. WOULD NOT BE COMPLETELY SHOCKED TO SEE VALUES CLOSER TO
30F...WHICH WOULD GIVE RH VALUES NEAR 25 PERCENT.
THE SFC HIGH WILL BE DIRECTLY OVERHEAD TUESDAY MORNING...BEFORE
SLIDING E. EXPECT THE RETURN OF S WINDS...AND A LITTLE BETTER
MOISTURE. WE WILL SEE STRONGER SOUTHERLY WINDS RETURN BRIEFLY
WEDNESDAY AFTERNOON. ADJUSTED MAX TEMPS UP OVER THE TRADITIONAL
DOWNSLOPE AREAS NEAR LAKE SUPERIOR...WITH 850MB TEMPS RISING TO 11
TO 15C WITH THE COOLEST VALUES EAST.
WENT ABOVE CONSENSUS FOR HIGH TEMPS THURSDAY...ONCE AGAIN WITH A
MORE SIGNIFICANT INCREASE TO DOWNSLOPE AREAS. 850MB WINDS PEG OUT
BETWEEN 45 AND 60KTS...AND TEMPS JUMP UP TO 15-18C. THE 19/00Z GFS
IS ONE OF THE COOLEST SOLUTIONS.
WILL BE INTERESTING HOW THE END OF THE WORK WEEK PANS OUT...AND IF
THE FRONTAL BOUNDARY SETS UP AND STALLS OVER THE W CWA LIKE THE
19/00Z ECMWF...OR BLOWS THROUGH OUR AREA THURSDAY NIGHT BEFORE
STALLING OVER LOWER MI FRIDAY INTO SATURDAY. WILL NOT GET TOO FANCY
WITH THE FORECAST THAT FAR OUT...AND WILL KEEP THE SLIGHT CHANCE/LOW
CHANCE POPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 752 AM EDT SAT MAY 19 2012
VFR CONDITIONS WILL REMAIN...WITH HIGH CLOUDS SLOWLY INVADING FROM THE
WEST AND LOWERING LOWER THE NEXT 24HRS. WINDS WILL CONTINUE TO BE THE
MAIN STORY...WITH 30-40KT WINDS JUST ABOVE THE SFC AND MIXED LAYER
THIS AFTERNOON...PARTICULARLY AT SAW AND IWD GIVEN THE FAVORABLE
DOWNSLOPE FLOW. WHILE THERE IS A SMALL POSSIBILITY OF A SHOWER OR TS
AT IWD JUST PRIOR TO DAYBREAK...BUT TOO SMALL OF A CHANCE TO INCLUDE
IN THE TAFS QUITE YET. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 508 AM EDT SAT MAY 19 2012
WINDS SHOULD REMAIN BELOW 30KTS THROUGH THE PERIOD. LOW PRESSURE
STRETCHING FROM SOUTHWESTERN QUEBEC TO NEBRASKA WILL SHIFT
NORTHEASTWARD...FILLING SLIGHTLY AS IT CROSSES LAKE SUPERIOR SUNDAY
INTO SUNDAY EVENING. BEHIND THIS FEATURE...HIGH PRESSURE WILL BUILD
ACROSS THE UPPER GREAT LAKES MONDAY AND MONDAY NIGHT. EXPECT THE
HIGH TO SLOWLY EXIT NORTHEASTWARD THROUGH MID WEEK...IN RESPONSE TO
A STRONGER LOW NEARING FROM SOUTH CENTRAL CANADA THROUGH THE CENTRAL
PLAINS. EXPECT THE LOW TO OUR WEST TO MOVE OVER ONTARIO ON
THURSDAY...BEFORE EDGING ACROSS LAKE SUPERIOR THURSDAY NIGHT.
&&
.FIRE WEATHER...
ISSUED AT 508 AM EDT SAT MAY 19 2012
AFTER AN OVERNGT OF RELATIVELY POOR RH RECOVERY...EXPECT ANOTHER DAY
OF AT LEAST NEAR CRITICAL FIRE WX PARAMETERS. MAX TEMPS THIS AFTN
WILL BE SIMILAR TO WHAT WAS OBSVD YDAY...BUT DEEPER MIXING SHOWN
ESPECIALLY ON THE 00Z MPX RAOB MIGHT TAP INTO LOWER DEWPTS. IN
FACT...SFC DEWPTS WERE AS LO AS 35 TO 45 UPSTREAM YDAY AFTN IN WRN
WI/SRN MN. BLENDED MIXED DEWPT TOOL VALUES WITH THE PREVIOUS FCST
DEWPTS TO COME UP WITH READINGS DIPPING AS LO AS 43 OR SO. WITH
WINDS ALOFT TDAY ALSO NEARLY SIMILAR TO YDAY AND DEEP MIXING RELATED
TO DAYTIME HEATING... SUSTAINED WINDS AS HI AS 10 TO 20 MPH WITH
GUSTS TO 30 MPH AT THE MORE EXPOSED LOCATIONS ARE LIKELY. OPTED TO
ISSUE RFW FOR AN ARK FROM IWD/ONTONAGON TO BARAGA/MQT
COUNTIES...AREAS THAT SAW THE POOREST RH RECOVERY EARLY THIS MRNG
AND WHERE STRONGER WINDS/HIER DAYTIME HI TEMPS ARE MOST LIKELY. WL
ISSUE RFD FOR THE OTHER COUNTIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
RED FLAG WARNING FROM 1 PM EDT /NOON CDT/ THIS AFTERNOON TO 8 PM
EDT /7 PM CDT/ THIS EVENING FOR MIZ002-004-005-009-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...KF
MARINE...KF
FIRE WEATHER...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
509 AM EDT SAT MAY 19 2012
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 508 AM EDT SAT MAY 19 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER THE
GREAT LAKES DOWNSTREAM OF TROF IN THE ROCKIES. CWA IS IN THE WARM
SECTOR E OF SFC-H85 TROF/COLD FNT AND S OF WARM FNT OVER NRN LK SUP/
ADJOINING ONTARIO. WITH DRYNESS SHOWN ON LOCAL 00Z RAOBS /H925 DEWPT
DEPRESSIONS ARE 15 TO 25C ON THE MPX/GRB RAOBS AND THE H85 DEWPT
DEPRESSION AT GRB WAS 49C/...SKIES ARE MOCLR OVER UPR MI. DESPITE
THE CLEAR SKIES/DRY AIR AND LOCAL DECOUPLING... TEMPS ARE WELL ABV
NORMAL WITH STEADY SW FLOW AT H925 LIMITING THE OVERALL DIURNAL TEMP
DROP. SOME SHRA/TS DID IMPACT MUCH OF MN THIS PAST EVNG DESPITE
FAIRLY DRY AIR.AS SHRTWV LIFTED NNEWD WELL E OF THE MAIN TROF TO THE
W...BUT THESE ARE TENDING TO WEAKEN AND STAY W OF EVEN LK SUP. MORE
WIDESPREAD SHRA/TS ARE LOCATED IN THE PLAINS CLOSER TO H85 COLD FNT.
MAIN FCST CONCERNS TDAY ARE FOCUSED ON FIRE WX. FOCUS FOR TNGT THRU
SUN SHIFTS TO SHRA/TS CHCS ASSOCIATED WITH SLOWLY APRCHG UPR TROF/
COLD FNT.
TDAY...CWA WL REMAIN UNDER WARM SW FLOW AS COLD FNT TO THE W SLIDES
EWD THRU MN. ALTHOUGH H85 TEMPS ARE FCST TO AVG ABOUT A DEGREE LOWER
THAN YDAY...VERY DEEP MIXING SHOWN ON THE 00Z MPX RAOB SHOULD
SUPPORT MAX TEMPS NEARLY SIMILAR TO WHAT OCCURRED ON FRI PER
UPSTREAM OBSVD SFC HI TEMPS...WITH SOME PLACES OVER THE W HALF
SEEING THE MERCURY REACH 90. GOING FCST SHOWING THESE HIER TEMPS IN
THE DOWNSLOPE AREAS FM ONTONAGON TO BARAGA LOOK ON TRACK. AREAS OVER
THE E HALF SHOULD SEE SOME MODERATION OFF LK MI. SOME LK MODERATION
MAY SLIP A BIT FARTHER W INTO THE CNTRL IF FCST BACKING WINDS TO
MORE DUE S DRAGS THE LK MI MODERATION INTO THAT AREA. SEE FIRE WX
SECTION BLO FOR A DISCUSSION OF FIRE WX CONCERNS.
TNGT...WITH BLDG UPR RDG FCST OVER THE ERN GRT LKS...OPTED TO FOLLOW
THE SOMEWHAT SLOWER 12Z ECMWF/00Z CNDN MODELS FOR THE TIMING OF THE
COLD FNT...ESPECIALLY SINCE A SHRTWV LIFTING NEWD OUT OF THE ROCKIES
WL INDUCE A LOW PRES TO DVLP ON THIS BNDRY OVER THE PLAINS TDAY.
THIS LO IS FCST TO MOVE INTO MN BY 12Z SUN. THE 00Z NAM HAS TRENDED
IN THIS DIRECTION AS WELL. IN FACT...THE 12Z ECMWF/0Z CNDN MODELS
INDICATE THE BULK OF ANY PCPN WL BE ON THE COLD SIDE OF THE FNT
AND STAY W OF IWD THRU 12Z. THIS FCST IS REASONABLE CONSIDERING THE
DRYNESS OF THE WARM SECTOR AIRMASS AND FCST DEEP LYR QVECTOR CNVGC
BEING FOCUSED UNDER THE SHARPER DPVA ASSOCIATED WITH THE SHRTWV ON
THE COLD SIDE OF THE FNT IN MN EVEN AS LATE AS 12Z SUN. STEADY SW
FLOW IN THE WARM SECTOR SHOULD ONCE AGAIN LIMIT THE DIURNAL FALL OF
TEMP...SO MINS WL BE WELL ABV NORMAL AGAIN.
SUN...SINCE THE FAVORED 12Z ECMWF/00Z CNDN MODELS SHOW BULK OF DEEP
LYR QVECTOR CNVGC SHIFTING NEWD THRU WRN LK SUP TOWARD ONTARIO...
SUSPECT THE HIER POPS WL BE OVER THE NW CWA...WITH PCPN TENDING TO
DIMINISH AS THE FNT SHIFTS TO THE E INTO THE CENTRAL CWA BY LATE
AFTN. HOWEVER...DAYTIME HEATING MAY OFFSET THE LOSS OF BEST
DYNAMICS...ESPECIALLY SINCE THE CNDN MODEL SHOWS HIER H85 DWPTS UP
TO 12C SURGING NEWD RIGHT ALONG THE FNT. HOWEVER...THIS SOMEWHAT
HIER MSTR IS STILL RELATIVELY LO COMPARED TO H85 TEMPS FCST ARND
16C. SO THE LLVLS WL STILL BE RATHER DRY PER THE MODEL FCST
SDNGS...LIMITING DESTABILIZATION. OPTED TO GO WITH LIKELY POPS OVER
THE NW CWA...DIMINISHING TO CHC FARTHER TO THE E. RAISED FCST HI
TEMPS WELL INTO THE 80S OVER THE E AND CNTRL AWAY FM LK MI
MODERATION TO ACCOUNT FOR SLOWER ARRIVAL OF COLD FNT.
SUN NGT...EXPECT COLD FNT TO PUSH THRU THE REST OF THE CWA
ACCOMPANIED BY CHC POPS AS MAIN SHRTWV/SHARPEST DEEP LYR QVECTOR
CNVGC EXITS TO THE NE AND ANY HELP FM DIURNAL HEATING WANES. SINCE
GUIDANCE HINTS AT THE ARPCH OF A SECOND SHRTWV FM MN...MAINTAINED
THE CHC POPS HANGING WELL BACK BEHIND THE COLD FNT AS HINTED AT BY
00Z NAM/12Z ECWMF AND SHOWN IN PREVIOUS FCST DESPITE MID LVL DRYING
IN THE WAKE OF THE INITIAL DISTURBANCE. IF THIS TRAILING SHRTWV IS
WEAKER...THE DRYING BEHIND THE FIRST STRONGER SHRTWV MAY END THE
POPS FASTER THAN FCST AS FCST BY THE 00Z CNDN. THE ARRIVAL OF H85
TEMPS AOB 5C OVER THE W BY 12Z MON WL BRING A RETURN OF MORE
SEASONABLE TEMPS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 508 AM EDT SAT MAY 19 2012
A SLOWLY TRANSITIONING WX PATTERN...WITH MUCH OF THE PERIOD
CONTINUING TO BE DOMINATED BY SOUTHERLY WINDS.
INITIALLY WE WILL HAVE THE EXITING COLD FRONT TO OUR EAST...AND HIGH
PRESSURE PUSHING IN FROM THE CENTRAL AND N PLAINS. AS A
RESULT...EXPECT TEMPS TO BE 10 TO 15 DEGREES COOLER THAN SUNDAY.
850MB TEMPS WILL BE 4-5C. WITH THE COOL TEMPS WILL COME DRY
AIR...WITH LOWER DEWPOINTS MONDAY AFTERNOON INTO THE MID 30S OVER
THE W HALF. WOULD NOT BE COMPLETELY SHOCKED TO SEE VALUES CLOSER TO
30F...WHICH WOULD GIVE RH VALUES NEAR 25 PERCENT.
THE SFC HIGH WILL BE DIRECTLY OVERHEAD TUESDAY MORNING...BEFORE
SLIDING E. EXPECT THE RETURN OF S WINDS...AND A LITTLE BETTER
MOISTURE. WE WILL SEE STRONGER SOUTHERLY WINDS RETURN BRIEFLY
WEDNESDAY AFTERNOON. ADJUSTED MAX TEMPS UP OVER THE TRADITIONAL
DOWNSLOPE AREAS NEAR LAKE SUPERIOR...WITH 850MB TEMPS RISING TO 11
TO 15C WITH THE COOLEST VALUES EAST.
WENT ABOVE CONSENSUS FOR HIGH TEMPS THURSDAY...ONCE AGAIN WITH A
MORE SIGNIFICANT INCREASE TO DOWNSLOPE AREAS. 850MB WINDS PEG OUT
BETWEEN 45 AND 60KTS...AND TEMPS JUMP UP TO 15-18C. THE 19/00Z GFS
IS ONE OF THE COOLEST SOLUTIONS.
WILL BE INTERESTING HOW THE END OF THE WORK WEEK PANS OUT...AND IF
THE FRONTAL BOUNDARY SETS UP AND STALLS OVER THE W CWA LIKE THE
19/00Z ECMWF...OR BLOWS THROUGH OUR AREA THURSDAY NIGHT BEFORE
STALLING OVER LOWER MI FRIDAY INTO SATURDAY. WILL NOT GET TOO FANCY
WITH THE FORECAST THAT FAR OUT...AND WILL KEEP THE SLIGHT CHANCE/LOW
CHANCE POPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 135 AM EDT SAT MAY 19 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. EASTERN EDGE OF LLJ
CENTERED OVER NE MN WILL CREATE LLWS ON THE ORDER OF 30 TO 35 KTS
OVER THE LOWEST 1KFT TONIGHT...WITH THE MOST PROMINENT SHEAR AT IWD.
LLWS IS EXPECTED TO SUBSIDE AFTER DAYBREAK SUNDAY AS MIXING IS
ESTABLISHED...BUT THIS WILL ALLOW FOR GUSTY SOUTHERLY WINDS AT ALL
SITES...ESPECIALLY AT IWD AND SAW. MID-LEVEL CLOUD COVER THICKENS
LATE SATURDAY. SHOWERS AND POSSIBLY A THUNDERSTORM COULD BEGIN TO
AFFECT IWD BY THE END OF THE PERIOD AS A TROUGH/COLD FRONT APPROACH
THE AREA...THOUGH THEY WILL LIKELY REMAIN TO THE WEST UNTIL AFTER
06Z. LLWS ALSO REEMERGES AT SAW AS THE LLJ REDEVELOPS FURTHER EAST
THAN TONIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 508 AM EDT SAT MAY 19 2012
WINDS SHOULD REMAIN BELOW 30KTS THROUGH THE PERIOD. LOW PRESSURE
STRETCHING FROM SOUTHWESTERN QUEBEC TO NEBRASKA WILL SHIFT
NORTHEASTWARD...FILLING SLIGHTLY AS IT CROSSES LAKE SUPERIOR SUNDAY
INTO SUNDAY EVENING. BEHIND THIS FEATURE...HIGH PRESSURE WILL BUILD
ACROSS THE UPPER GREAT LAKES MONDAY AND MONDAY NIGHT. EXPECT THE
HIGH TO SLOWLY EXIT NORTHEASTWARD THROUGH MID WEEK...IN RESPONSE TO
A STRONGER LOW NEARING FROM SOUTH CENTRAL CANADA THROUGH THE CENTRAL
PLAINS. EXPECT THE LOW TO OUR WEST TO MOVE OVER ONTARIO ON
THURSDAY...BEFORE EDGING ACROSS LAKE SUPERIOR THURSDAY NIGHT.
&&
.FIRE WEATHER...
ISSUED AT 508 AM EDT SAT MAY 19 2012
AFTER AN OVERNGT OF RELATIVELY POOR RH RECOVERY...EXPECT ANOTHER DAY
OF AT LEAST NEAR CRITICAL FIRE WX PARAMETERS. MAX TEMPS THIS AFTN
WILL BE SIMILAR TO WHAT WAS OBSVD YDAY...BUT DEEPER MIXING SHOWN
ESPECIALLY ON THE 00Z MPX RAOB MIGHT TAP INTO LOWER DEWPTS. IN
FACT...SFC DEWPTS WERE AS LO AS 35 TO 45 UPSTREAM YDAY AFTN IN WRN
WI/SRN MN. BLENDED MIXED DEWPT TOOL VALUES WITH THE PREVIOUS FCST
DEWPTS TO COME UP WITH READINGS DIPPING AS LO AS 43 OR SO. WITH
WINDS ALOFT TDAY ALSO NEARLY SIMILAR TO YDAY AND DEEP MIXING RELATED
TO DAYTIME HEATING... SUSTAINED WINDS AS HI AS 10 TO 20 MPH WITH
GUSTS TO 30 MPH AT THE MORE EXPOSED LOCATIONS ARE LIKELY. OPTED TO
ISSUE RFW FOR AN ARK FROM IWD/ONTONAGON TO BARAGA/MQT
COUNTIES...AREAS THAT SAW THE POOREST RH RECOVERY EARLY THIS MRNG
AND WHERE STRONGER WINDS/HIER DAYTIME HI TEMPS ARE MOST LIKELY. WL
ISSUE RFD FOR THE OTHER COUNTIES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
RED FLAG WARNING FROM 1 PM EDT /NOON CDT/ THIS AFTERNOON TO 8 PM
EDT /7 PM CDT/ THIS EVENING FOR MIZ002-004-005-009-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...TK
MARINE...KF
FIRE WEATHER...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1255 PM CDT SAT MAY 19 2012
.UPDATE...
UPDATED FOR AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
/ISSUED 429 AM CDT SAT MAY 19 2012/
WATER VAPOR IMAGERY AND RUC H5 ANALYSIS SHOWS A RATHER EXPANSIVE
RIDGE IN PLACE THIS MORNING EAST OF THE MS RIVER...WITH A RATHER
COMPLEX TROUGH MOVING INTO THE HIGH PLAINS...WITH SEVERAL
SHORTWAVES EMBEDDED WITHIN IT. THE TWO PRIMARY ONES ARE CURRENTLY
OVER ERN SODAK AND MOVING FROM CO UP INTO SRN NEB. AT THE
SFC...A COUPLE OF AREAS OF LOW PRESSURE COULD BE FOUND OVER FAR NW
ONTARIO...WITH ANOTHER NEAR THE CO/NEB/KS BORDER. A COLD FRONT IS
ANALYZED BETWEEN THESE LOWS ACROSS THE ERN DAKOTAS.
FOR THE H5 PATTERN...THE RIDGING NOW MOVING ON TO THE HIGH PLAINS
WILL SLOWLY BEAT DOWN THE ERN RIDGE...WITH THE TROUGH CURRENTLY
COMING OUT OF CO WORKING ACROSS THE MPX CWA SUN INTO SUN EVENING.
FOR MON/TUE...RIDGING WILL BE BUILDING IN ACROSS CENTRAL NOAM AS A
SIGNIFICANT TROUGH DIGS INTO THE PAC NW. AS WE HEAD THROUGH THE
SECOND HALF OF NEXT WEEK...THIS PATTERN LOOKS BECOME QUITE
AMPLIFIED...AS VERY HIGH HEIGHTS SET UP INTO THE GREAT
LAKES...WITH A QUASI-STATIONARY DEEP TROUGH TAKING HOLD ACROSS
THE NRN ROCKIES...SETTING THE UPPER MIDWEST UP INTO A POTENTIAL
ACTIVE PATTERN.
AT THE SFC...THE COLD FRONT WILL WORK INTO WRN MN BY THIS
AFTERNOON...AND CLEAR THE MPX WI COUNTIES SUN AFTERNOON. THE LOW
CENTER CURRENTLY NEAR THE CO/NEB/KS WILL TRACK ACROSS SOUTH
CENTRAL MN INTO THE WRN TIP OF THE U.P. OF MICH SAT NIGHT/SUN.
HIGH PRESSURE WILL THEN SLIDE ACROSS THE AREA MON/TUE...BEFORE LEE
SIDE TROUGHING REESTABLISHES ITSELF OVER THE NRN HIGH PLAINS WED.
NEXT FRONT STILL ON TAP TO MOVE INTO MN WED NIGHT...AND WITH UPPER
RIDGE AMPLIFYING OVER THE GREAT LAKES THE LATTER HALF OF NEXT
WEEK...THIS FRONT STILL LOOKS TO STALL OUT THEN MEANDER AROUND THE
UPPER MS VALLEY INTO THE HOLIDAY WEEKEND.
THIS MORNING...STRONG WAA OUT AHEAD OF THE ERN SODAK SHORTWAVE
HAS RESULTED IN THE DEVELOPMENT OF AN AREA OF TSRA OVER WRN
MN...RADAR TRENDS MATCH WELL WITH THE IDEA THE RUC IS
SHOWING...WITH THIS WAA AND ASSOCIATED ACTIVITY BASICALLY GOING
DUE NORTH INTO NW MN. DO EXPECT CONDITIONS TO BE FAIRLY QUIET
THROUGH THE MORNING...WITH THE SODAK SHORTWAVE AND COLD FRONT
EXPECTED TO REMAIN WEST OF THE AREA. ONE CAVEAT IS THE LLJ AND
STRONG MOISTURE TRANSPORT IN PLACE ACROSS THE WEST. THIS MAY KEEP
SCT SHRA/TSRA ACTIVITY GOING THROUGH THE MORNING OUT WEST...BUT
DID NOT PLAY THIS IDEA UP TO MUCH IN THE GRIDS. INSTEAD...WAITED
UNTIL THE AFTERNOON TO REALLY GET POPS GOING. BY THEN THE COLD
FRONT WILL BE WORKING INTO WRN MN AS UPPER ENERGY BEGINS TO WORK
IN OVERHEAD. LOOKING AT HIRES REFLECTIVITY FORECASTS...SEEMS TO BE
GOOD AGREEMENT WITH STORMS INITIATING NEAR A RWF TO LONG PRAIRIE
LINE BETWEEN 20 AND 22Z...WITH ACTIVITY WORKING EAST TOWARD THE
I-35 CORRIDOR SHORTLY AFTER 00Z. FORECAST SOUNDINGS AGAIN SHOW
NICE INVERTED-V STRUCTURE THIS AFTERNOON...WITH MLCAPE AGAIN
PUSHING UP TO AROUND 1500 J/KG. IN ADDITION...UNLIKE
YESTERDAY...BULK SHEAR WILL BE IN THE 30-40 KT RANGE...INDICATING
SOME BETTER ORGANIZATION IN CONVECTION IS POSSIBLE. GIVEN LESS
FAVORABLE CONDITIONS MANAGED A FEW 60-70 MPH WIND GUSTS AND GOLF
BALL SIZE HAIL FRIDAY...DO NOT SEE WHY WE DO NOT HAVE A SIMILAR
THREAT FOR SEVERE WEATHER TODAY. IF ANYTHING...WOULD SUSPECT THE
WIND THREAT IS A BIT HIGHER AS BETTER SHEAR AND FAVORABLE
CONDITIONS FOR COLD POOL GENERATION MAY SUPPORT THE DEVELOPMENT OF
ORGANIZED LINE SEGMENTS. BESIDE THE PRECIP...SHOULD BE ANOTHER
WARM DAY...THOUGH NOT EXPECTING WIDESPREAD 90S LIKE FRIDAY. TWO
LIMITING FACTORS FOR HIGHS TODAY WILL BE MORE CLOUD COVER AND
ABOUT A 4 DEG C DROP IN H85 TEMPS. WITH THAT SAID...GUIDANCE HAS
HAD A PRETTY STRONG COLD BIAS IN THIS HEAT WAVE...SO CONTINUED TO
RUN WITH HIGHS A BIT HIGHER THAN WHAT MOST GUIDANCE WOULD SUGGEST.
FOR TONIGHT...WITH THE ARRIVAL OF THE UPPER TROUGH AND ATTENDANT
SFC LOW...WE CONTINUE TO SEE A STRONG SIGNAL FOR THE FORMATION OF
A DEFORMATION BAND OF PRECIP JUST TO THE WEST OF THE SFC LOW
TRACK. BLENDED THE ECMWF/GEM/SREF FOR PRECIP TONIGHT...WITH
HEAVIEST BAND OF PRECIP EXPECTED TO SETUP BETWEEN THE WRN TWIN
CITIES METRO AND MARSHALL/ALEXANDRIA. WITH THE SFC LOW COMING
THROUGH...THIS REALLY SLOWS DOWN THE PRECIP...AND CONTINUED TO
LEAN TIMING OF POPS ON SUN CLOSE TO THE ECMWF. THE ECMWF ALONG THE
NAM/SREF WOULD INDICATE SUNDAY BEING CLOUDY/RAINY FOR MOST OF THE
DAY SUNDAY ACROSS MOST OF THE MN MPX AREA...WITH HIGHS LIKELY NOT
LEAVING THE LOWER 60S. FURTHER EAST...THE COLD FRONT/LOW SHOULD BE
NEAR AN EAU/LADYSMITH LINE BY 18Z...SO SEVERE THREAT CERTAINLY
LOOKS BETTER EAST...THOUGH A MARGINAL TREAT FOR SEVERE WEATHER CAN
NOT BE RULED OUT IN THE FAR EAST.
MON THROUGH WED STILL LOOK DRY AS HIGH PRESSURE SLIDES ACROSS THE
AREA. BIGGEST THING TO WATCH WILL BE LOWS MONDAY MORNING. IF HIGHS
ONLY TOP OUT AROUND 60 IN CENTRAL MN...WE COULD SEE LOWS MONDAY
MORNING MAKE A RUN AT THE UPPER 30S AS HIGH PRESSURES MOVES IN AND
SKIES CLEAR OUT. OTHER THAN THAT...ITS OFF TO WAITING FOR THE NEXT
FRONT WEDNESDAY NIGHT. THE ONLY SIGNIFICANT CHANGE NOTED IN THE
MODELS WITH THIS FRONT IS THE 19.00 ECMWF BASICALLY HALTS ITS EWRD
PROGRESSION ACROSS WRN MN...WITH THE RAIN NOT MAKING IT TO ERN
AREAS. AT ANY RATE...CONTINUED TO MENTION HIGH CHANCE/LIKELY
POPS...ESPECIALLY WEST WED NIGHT. AFTER THAT...THE QUESTION
BECOMES WHERE DOES THE FRONT SET UP. WHERE EVER IT DOES SETUP...NORTH
OF THE BOUNDARY THROUGH THE WEEKEND IS LOOKING LIKE IT COULD BE A
BREEDING GROUND FOR SOME ACTIVE WEATHER...CERTAINLY SOMETHING TO
KEEP A CLOSE EYE ON AS WE HEAD INTO THE BUSY HOLIDAY WEEKEND.
&&
.AVIATION.../18Z TAF ISSUANCE/
THE MAIN AVIATION CONCERNS REMAIN...TIMING OF THUNDER THIS
AFTERNOON/TONIGHT AND DEVELOPMENT OF MVFR/IFR CEILINGS. COLD FRONT
PUSHING INTO WEST CENTRAL MINNESOTA AT THIS TIME...MOVED THROUGH
KAXN AS OF 18Z. THIS SHOULD DISSIPATE ANY SIGNIFICANT THREAT OF
THUNDER THERE THIS AFTERNOON. STILL INCLUDED TEMPO FOR A FEW HOURS
LATE THE AFTERNOON...AS IT REMAINS CLOSE TO FRONT. REMAINDER OF
AREA REMAINS TIMING ISSUE. INITIAL SHORT WAVE APPEARS TO BE MOVING
THROUGH EAST CENTRAL MN AT THIS TIME. SHOWERS DISSIPATED PER MODEL
TRENDS. STILL SOME THREAT OF REDEVELOPMENT EAST CENTRAL INTO
WISCONSIN THIS AFTERNOON...WHERE HIGH INSTABILITY REMAINS. BETTER
LIFT LOOKS TO ARRIVE LATER THIS AFTERNOON INTO THE EVENING WITH
TEMPO THUNDER CONTINUED AHEAD OF THE FRONT TONIGHT. EXPECT MVFR
CEILINGS INTO KAXN THIS AFTERNOON...AND THEN LOWERING TOWARD
KSTC-KRWF TONIGHT WITH POST-FRONTAL RAIN. BEST CHANCE FOR IFR WILL
BE THE KRWF TO KSTC AREA. THIS ALL SPREADS EAST OVERNIGHT/SUNDAY
MORNING AND SHOULD END IN EASTERN MN THROUGH 14Z AND BEFORE 19Z IN
WEST CENTRAL WISCONSIN.
KMSP...WEAK WAVE MOVING ACROSS AREA EARLY...MAY INITIATE
SHOWERS/STORMS INTO WESTERN WISCONSIN. OTHERWISE...WILL HAVE TO WAIT
FOR COLD FRONT AS IT MOVES INTO THE AREA THIS EVENING. SHOULD MOVE
THROUGH BY 06Z WITH THUNDER THREAT ENDING THEN. LINGERING SHRA AND
MVFR CEILINGS BEHIND FRONT THROUGH ABOUT 12Z...BECOMING VFR AGAIN
AFTER 15Z SUNDAY.
OUTLOOK...
SUN...SHRA AND SOME TSRA POSSIBLE IN THE MORNING FAR EASTERN MN AND
WESTERN WI WITH MVFR/IFR POSSIBLE THEN IMPROVING CONDITIONS BY
SUNDAY AFTERNOON ALL BUT WESTERN WISCONSIN.
SUN NIGHT MON-TUE...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/TDK
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
708 AM CDT SAT MAY 19 2012
.UPDATE...
UPDATED FOR AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
/ISSUED 429 AM CDT SAT MAY 19 2012/
WATER VAPOR IMAGERY AND RUC H5 ANALYSIS SHOWS A RATHER EXPANSIVE
RIDGE IN PLACE THIS MORNING EAST OF THE MS RIVER...WITH A RATHER
COMPLEX TROUGH MOVING INTO THE HIGH PLAINS...WITH SEVERAL
SHORTWAVES EMBEDDED WITHIN IT. THE TWO PRIMARY ONES ARE CURRENTLY
OVER ERN SODAK AND MOVING FROM CO UP INTO SRN NEB. AT THE
SFC...A COUPLE OF AREAS OF LOW PRESSURE COULD BE FOUND OVER FAR NW
ONTARIO...WITH ANOTHER NEAR THE CO/NEB/KS BORDER. A COLD FRONT IS
ANALYZED BETWEEN THESE LOWS ACROSS THE ERN DAKOTAS.
FOR THE H5 PATTERN...THE RIDGING NOW MOVING ON TO THE HIGH PLAINS
WILL SLOWLY BEAT DOWN THE ERN RIDGE...WITH THE TROUGH CURRENTLY
COMING OUT OF CO WORKING ACROSS THE MPX CWA SUN INTO SUN EVENING.
FOR MON/TUE...RIDGING WILL BE BUILDING IN ACROSS CENTRAL NOAM AS A
SIGNIFICANT TROUGH DIGS INTO THE PAC NW. AS WE HEAD THROUGH THE
SECOND HALF OF NEXT WEEK...THIS PATTERN LOOKS BECOME QUITE
AMPLIFIED...AS VERY HIGH HEIGHTS SET UP INTO THE GREAT
LAKES...WITH A QUASI-STATIONARY DEEP TROUGH TAKING HOLD ACROSS
THE NRN ROCKIES...SETTING THE UPPER MIDWEST UP INTO A POTENTIAL
ACTIVE PATTERN.
AT THE SFC...THE COLD FRONT WILL WORK INTO WRN MN BY THIS
AFTERNOON...AND CLEAR THE MPX WI COUNTIES SUN AFTERNOON. THE LOW
CENTER CURRENTLY NEAR THE CO/NEB/KS WILL TRACK ACROSS SOUTH
CENTRAL MN INTO THE WRN TIP OF THE U.P. OF MICH SAT NIGHT/SUN.
HIGH PRESSURE WILL THEN SLIDE ACROSS THE AREA MON/TUE...BEFORE LEE
SIDE TROUGHING REESTABLISHES ITSELF OVER THE NRN HIGH PLAINS WED.
NEXT FRONT STILL ON TAP TO MOVE INTO MN WED NIGHT...AND WITH UPPER
RIDGE AMPLIFYING OVER THE GREAT LAKES THE LATTER HALF OF NEXT
WEEK...THIS FRONT STILL LOOKS TO STALL OUT THEN MEANDER AROUND THE
UPPER MS VALLEY INTO THE HOLIDAY WEEKEND.
THIS MORNING...STRONG WAA OUT AHEAD OF THE ERN SODAK SHORTWAVE
HAS RESULTED IN THE DEVELOPMENT OF AN AREA OF TSRA OVER WRN
MN...RADAR TRENDS MATCH WELL WITH THE IDEA THE RUC IS
SHOWING...WITH THIS WAA AND ASSOCIATED ACTIVITY BASICALLY GOING
DUE NORTH INTO NW MN. DO EXPECT CONDITIONS TO BE FAIRLY QUIET
THROUGH THE MORNING...WITH THE SODAK SHORTWAVE AND COLD FRONT
EXPECTED TO REMAIN WEST OF THE AREA. ONE CAVEAT IS THE LLJ AND
STRONG MOISTURE TRANSPORT IN PLACE ACROSS THE WEST. THIS MAY KEEP
SCT SHRA/TSRA ACTIVITY GOING THROUGH THE MORNING OUT WEST...BUT
DID NOT PLAY THIS IDEA UP TO MUCH IN THE GRIDS. INSTEAD...WAITED
UNTIL THE AFTERNOON TO REALLY GET POPS GOING. BY THEN THE COLD
FRONT WILL BE WORKING INTO WRN MN AS UPPER ENERGY BEGINS TO WORK
IN OVERHEAD. LOOKING AT HIRES REFLECTIVITY FORECASTS...SEEMS TO BE
GOOD AGREEMENT WITH STORMS INITIATING NEAR A RWF TO LONG PRAIRIE
LINE BETWEEN 20 AND 22Z...WITH ACTIVITY WORKING EAST TOWARD THE
I-35 CORRIDOR SHORTLY AFTER 00Z. FORECAST SOUNDINGS AGAIN SHOW
NICE INVERTED-V STRUCTURE THIS AFTERNOON...WITH MLCAPE AGAIN
PUSHING UP TO AROUND 1500 J/KG. IN ADDITION...UNLIKE
YESTERDAY...BULK SHEAR WILL BE IN THE 30-40 KT RANGE...INDICATING
SOME BETTER ORGANIZATION IN CONVECTION IS POSSIBLE. GIVEN LESS
FAVORABLE CONDITIONS MANAGED A FEW 60-70 MPH WIND GUSTS AND GOLF
BALL SIZE HAIL FRIDAY...DO NOT SEE WHY WE DO NOT HAVE A SIMILAR
THREAT FOR SEVERE WEATHER TODAY. IF ANYTHING...WOULD SUSPECT THE
WIND THREAT IS A BIT HIGHER AS BETTER SHEAR AND FAVORABLE
CONDITIONS FOR COLD POOL GENERATION MAY SUPPORT THE DEVELOPMENT OF
ORGANIZED LINE SEGMENTS. BESIDE THE PRECIP...SHOULD BE ANOTHER
WARM DAY...THOUGH NOT EXPECTING WIDESPREAD 90S LIKE FRIDAY. TWO
LIMITING FACTORS FOR HIGHS TODAY WILL BE MORE CLOUD COVER AND
ABOUT A 4 DEG C DROP IN H85 TEMPS. WITH THAT SAID...GUIDANCE HAS
HAD A PRETTY STRONG COLD BIAS IN THIS HEAT WAVE...SO CONTINUED TO
RUN WITH HIGHS A BIT HIGHER THAN WHAT MOST GUIDANCE WOULD SUGGEST.
FOR TONIGHT...WITH THE ARRIVAL OF THE UPPER TROUGH AND ATTENDANT
SFC LOW...WE CONTINUE TO SEE A STRONG SIGNAL FOR THE FORMATION OF
A DEFORMATION BAND OF PRECIP JUST TO THE WEST OF THE SFC LOW
TRACK. BLENDED THE ECMWF/GEM/SREF FOR PRECIP TONIGHT...WITH
HEAVIEST BAND OF PRECIP EXPECTED TO SETUP BETWEEN THE WRN TWIN
CITIES METRO AND MARSHALL/ALEXANDRIA. WITH THE SFC LOW COMING
THROUGH...THIS REALLY SLOWS DOWN THE PRECIP...AND CONTINUED TO
LEAN TIMING OF POPS ON SUN CLOSE TO THE ECMWF. THE ECMWF ALONG THE
NAM/SREF WOULD INDICATE SUNDAY BEING CLOUDY/RAINY FOR MOST OF THE
DAY SUNDAY ACROSS MOST OF THE MN MPX AREA...WITH HIGHS LIKELY NOT
LEAVING THE LOWER 60S. FURTHER EAST...THE COLD FRONT/LOW SHOULD BE
NEAR AN EAU/LADYSMITH LINE BY 18Z...SO SEVERE THREAT CERTAINLY
LOOKS BETTER EAST...THOUGH A MARGINAL TREAT FOR SEVERE WEATHER CAN
NOT BE RULED OUT IN THE FAR EAST.
MON THROUGH WED STILL LOOK DRY AS HIGH PRESSURE SLIDES ACROSS THE
AREA. BIGGEST THING TO WATCH WILL BE LOWS MONDAY MORNING. IF HIGHS
ONLY TOP OUT AROUND 60 IN CENTRAL MN...WE COULD SEE LOWS MONDAY
MORNING MAKE A RUN AT THE UPPER 30S AS HIGH PRESSURES MOVES IN AND
SKIES CLEAR OUT. OTHER THAN THAT...ITS OFF TO WAITING FOR THE NEXT
FRONT WEDNESDAY NIGHT. THE ONLY SIGNIFICANT CHANGE NOTED IN THE
MODELS WITH THIS FRONT IS THE 19.00 ECMWF BASICALLY HALTS ITS EWRD
PROGRESSION ACROSS WRN MN...WITH THE RAIN NOT MAKING IT TO ERN
AREAS. AT ANY RATE...CONTINUED TO MENTION HIGH CHANCE/LIKELY
POPS...ESPECIALLY WEST WED NIGHT. AFTER THAT...THE QUESTION
BECOMES WHERE DOES THE FRONT SET UP. WHERE EVER IT DOES SETUP...NORTH
OF THE BOUNDARY THROUGH THE WEEKEND IS LOOKING LIKE IT COULD BE A
BREEDING GROUND FOR SOME ACTIVE WEATHER...CERTAINLY SOMETHING TO
KEEP A CLOSE EYE ON AS WE HEAD INTO THE BUSY HOLIDAY WEEKEND.
&&
.AVIATION.../12Z TAF ISSUANCE/
TWO MAIN ISSUES...TIMING OF STORMS TODAY/TONIGHT AND EVENTUAL MVFR/IFR
LATER TONIGHT. SIGNIFICANT INFLUX OF MOISTURE IN WESTERN MN AHEAD
OF FRONT. NEXT LOBE OF STORMS JUST ENTERING SW MN ASSOCIATED WITH WEAK
SHORT WAVE. RWF/AXN/STC AT RISK FOR THUNDER LATE THIS MORNING INTO
THE EARLY AFTERNOON FROM THIS. WEAKENING OF SYSTEM COULD RESULT IN
ONLY SHOWERS BY THE TIME IT REACHES EASTERN MN DURING MIDDAY.
BETTER LIFT LOOKS TO ARRIVE LATER THIS AFTERNOON AND HAVE ADDED
THUNDER TO EASTERN MN AND WESTERN WI. CONFIDENCE IS ABOVE AVERAGE
ON EXISTENCE OF STORMS... BUT BELOW AVERAGE ON TIMING...
ESPECIALLY ON STORMS MID AFTERNOON INTO THE EVENING. EXPECT MVFR
CEILINGS AND MAYBE VISIBILITIES TONIGHT WITH POST-FRONTAL RAIN.
BEST CHANCE FOR IFR WILL BE THE KRWF TO KSTC AREA.
KMSP...SHOWERS AND A FEW STORMS IN FAR SWRN MN INTO WESTERN IOWA
AT THIS TIME. THINK THESE WILL WEAKEN BY THE TIME THEY REACH KMSP
AND RESULT IN JUST SOME SCATTERED SHOWERS DURING MIDDAY...WITH A BELOW
AVERAGE CHANCE THAT THERE WILL STILL BE THUNDER BY THE TIME PRECIP
GETS HERE AROUND 18Z-19Z. BETTER CHANCE FOR THUNDER LATE AFTERNOON
WITH NEXT WAVE. TIMING OF INCOMING COLD FRONT LOOKS TO BE AROUND
02Z-06Z FOLLOWED BY MVFR CEILINGS IN PRECIP.
OUTLOOK...
SUN...SHRA AND SOME TSRA POSSIBLE IN THE MORNING WITH MVFR/IFR
POSSIBLE THEN IMPROVING CONDITIONS LATER ON SUNDAY.
SUN NIGHT MON-TUE...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/TDK
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
429 AM CDT SAT MAY 19 2012
.DISCUSSION...
WATER VAPOR IMAGERY AND RUC H5 ANALYSIS SHOWS A RATHER EXPANSIVE
RIDGE IN PLACE THIS MORNING EAST OF THE MS RIVER...WITH A RATHER
COMPLEX TROUGH MOVING INTO THE HIGH PLAINS...WITH SEVERAL
SHORTWAVES EMBEDDED WITHIN IT. THE TWO PRIMARY ONES ARE CURRENTLY
OVER ERN SODAK AND MOVING FROM CO UP INTO SRN NEB. AT THE
SFC...A COUPLE OF AREAS OF LOW PRESSURE COULD BE FOUND OVER FAR SW
ONTARIO...WITH ANOTHER NEAR THE CO/NEB/KS BORDER. A COLD FRONT IS
ANALYZED BETWEEN THESE LOWS ACROSS THE ERN DAKOTAS.
FOR THE H5 PATTERN...THE RIDGING NOW MOVING ON TO THE HIGH PLAINS
WILL SLOWLY BEAT DOWN THE ERN RIDGE...WITH THE TROUGH CURRENTLY
COMING OUT OF CO WORKING ACROSS THE MPX CWA SUN INTO SUN EVENING.
FOR MON/TUE...RIDGING WILL BE BUILDING IN ACROSS CENTRAL NOAM AS A
SIGNIFICANT TROUGH DIGS INTO THE PAC NW. AS WE HEAD THROUGH THE
SECOND HALF OF NEXT WEEK...THIS PATTERN LOOKS BECOME QUITE
AMPLIFIED...AS VERY HIGH HEIGHTS SET UP INTO THE GREAT
LAKES...WITH A QUASI-STATIONARY DEEP TROUGH TAKING HOLD ACROSS
THE NRN ROCKIES...SETTING THE UPPER MIDWEST UP INTO A POTENTIAL
ACTIVE PATTERN.
AT THE SFC...THE COLD FRONT WILL WORK INTO WRN MN BY THIS
AFTERNOON...AND CLEAR THE MPX WI COUNTIES SUN AFTERNOON. THE LOW
CENTER CURRENTLY NEAR THE CO/NEB/KS WILL TRACK ACROSS SOUTH
CENTRAL MN INTO THE WRN TIP OF THE U.P. OF MICH SAT NIGHT/SUN.
HIGH PRESSURE WILL THEN SLIDE ACROSS THE AREA MON/TUE...BEFORE LEE
SIDE TROUGHING REESTABLISHES ITSELF OVER THE NRN HIGH PLAINS WED.
NEXT FRONT STILL ON TAP TO MOVE INTO MN WED NIGHT...AND WITH UPPER
RIDGE AMPLIFYING OVER THE GREAT LAKES THE LATTER HALF OF NEXT
WEEK...THIS FRONT STILL LOOKS TO STALL OUT THEN MEANDER AROUND THE
UPPER MS VALLEY INTO THE HOLIDAY WEEKEND.
THIS MORNING...STRONG WAA OUT AHEAD OF THE ERN SODAK SHORTWAVE
HAS RESULTED IN THE DEVELOPMENT OF AN AREA OF TSRA OVER WRN
MN...RADAR TRENDS MATCH WELL WITH THE IDEA THE RUC IS
SHOWING...WITH THIS WAA AND ASSOCIATED ACTIVITY BASICALLY GOING
DUE NORTH INTO NW MN. DO EXPECT CONDITIONS TO BE FAIRLY QUIET
THROUGH THE MORNING...WITH THE SODAK SHORTWAVE AND COLD FRONT
EXPECTED TO REMAIN WEST OF THE AREA. ONE CAVEAT IS THE LLJ AND
STRONG MOISTURE TRANSPORT IN PLACE ACROSS THE WEST. THIS MAY KEEP
SCT SHRA/TSRA ACTIVITY GOING THROUGH THE MORNING OUT WEST...BUT
DID NOT PLAY THIS IDEA UP TO MUCH IN THE GRIDS. INSTEAD...WAITED
UNTIL THE AFTERNOON TO REALLY GET POPS GOING. BY THEN THE COLD
FRONT WILL BE WORKING INTO WRN MN AS UPPER ENERGY BEGINS TO WORK
IN OVERHEAD. LOOKING AT HIRES REFLECTIVITY FORECASTS...SEEMS TO BE
GOOD AGREEMENT WITH STORMS INITIATING NEAR A RWF TO LONG PRAIRIE
LINE BETWEEN 20 AND 22Z...WITH ACTIVITY WORKING EAST TOWARD THE
I-35 CORRIDOR SHORTLY AFTER 00Z. FORECAST SOUNDINGS AGAIN SHOW
NICE INVERTED-V STRUCTURE THIS AFTERNOON...WITH MLCAPE AGAIN
PUSHING UP TO AROUND 1500 J/KG. IN ADDITION...UNLIKE
YESTERDAY...BULK SHEAR WILL BE IN THE 30-40 KT RANGE...INDICATING
SOME BETTER ORGANIZATION IN CONVECTION IS POSSIBLE. GIVEN LESS
FAVORABLE CONDITIONS MANAGED A FEW 60-70 MPH WIND GUSTS AND GOLF
BALL SIZE HAIL FRIDAY...DO NOT SEE WHY WE DO NOT HAVE A SIMILAR
THREAT FOR SEVERE WEATHER TODAY. IF ANYTHING...WOULD SUSPECT THE
WIND THREAT IS A BIT HIGHER AS BETTER SHEAR AND FAVORABLE
CONDITIONS FOR COLD POOL GENERATION MAY SUPPORT THE DEVELOPMENT OF
ORGANIZED LINE SEGMENTS. BESIDE THE PRECIP...SHOULD BE ANOTHER
WARM DAY...THOUGH NOT EXPECTING WIDESPREAD 90S LIKE FRIDAY. TWO
LIMITING FACTORS FOR HIGHS TODAY WILL BE MORE CLOUD COVER AND
ABOUT A 4 DEG C DROP IN H85 TEMPS. WITH THAT SAID...GUIDANCE HAS
HAD A PRETTY STRONG COLD BIAS IN THIS HEAT WAVE...SO CONTINUED TO
RUN WITH HIGHS A BIT HIGHER THAN WHAT MOST GUIDANCE WOULD SUGGEST.
FOR TONIGHT...WITH THE ARRIVAL OF THE UPPER TROUGH AND ATTENDANT
SFC LOW...WE CONTINUE TO SEE A STRONG SIGNAL FOR THE FORMATION OF
A DEFORMATION BAND OF PRECIP JUST TO THE WEST OF THE SFC LOW
TRACK. BLENDED THE ECMWF/GEM/SREF FOR PRECIP TONIGHT...WITH
HEAVIEST BAND OF PRECIP EXPECTED TO SETUP BETWEEN THE WRN TWIN
CITIES METRO AND MARSHALL/ALEXANDRIA. WITH THE SFC LOW COMING
THROUGH...THIS REALLY SLOWS DOWN THE PRECIP...AND CONTINUED TO
LEAN TIMING OF POPS ON SUN CLOSE TO THE ECMWF. THE ECMWF ALONG THE
NAM/SREF WOULD INDICATE SUNDAY BEING CLOUDY/RAINY FOR MOST OF THE
DAY SUNDAY ACROSS MOST OF THE MN MPX AREA...WITH HIGHS LIKELY NOT
LEAVING THE LOWER 60S. FURTHER EAST...THE COLD FRONT/LOW SHOULD BE
NEAR AN EAU/LADYSMITH LINE BY 18Z...SO SEVERE THREAT CERTAINLY
LOOKS BETTER EAST...THOUGH A MARGINAL TREAT FOR SEVERE WEATHER CAN
NOT BE RULED OUT IN THE FAR EAST.
MON THROUGH WED STILL LOOK DRY AS HIGH PRESSURE SLIDES ACROSS THE
AREA. BIGGEST THING TO WATCH WILL BE LOWS MONDAY MORNING. IF HIGHS
ONLY TOP OUT AROUND 60 IN CENTRAL MN...WE COULD SEE LOWS MONDAY
MORNING MAKE A RUN AT THE UPPER 30S AS HIGH PRESSURES MOVES IN AND
SKIES CLEAR OUT. OTHER THAN THAT...ITS OFF TO WAITING FOR THE NEXT
FRONT WEDNESDAY NIGHT. THE ONLY SIGNIFICANT CHANGE NOTED IN THE
MODELS WITH THIS FRONT IS THE 19.00 ECMWF BASICALLY HALTS ITS EWRD
PROGRESSION ACROSS WRN MN...WITH THE RAIN NOT MAKING IT TO ERN
AREAS. AT ANY RATE...CONTINUED TO MENTION HIGH CHANCE/LIKELY
POPS...ESPECIALLY WEST WED NIGHT. AFTER THAT...THE QUESTION
BECOMES WHERE DOES THE FRONT SET UP. WHERE EVER IT DOES SETUP...NORTH
OF THE BOUNDARY THROUGH THE WEEKEND IS LOOKING LIKE IT COULD BE A
BREEDING GROUND FOR SOME ACTIVE WEATHER...CERTAINLY SOMETHING TO
KEEP A CLOSE EYE ON AS WE HEAD INTO THE BUSY HOLIDAY WEEKEND.
&&
.AVIATION.../06Z TAF ISSUANCE/
OVER THE NEXT 48 HOURS...THUNDERSTORM CHANCES WILL BE THE MAIN
FORECAST CHALLENGE. ONGOING THUNDERSTORM ACTIVITY WAS ASSOCIATED
WITH AN UPPER LEVEL DISTURBANCE THAT HAD MOVE INTO MN LATE FRIDAY
AFTERNOON. THE THUNDERSTORMS CONTINUE TO DEVELOP ALONG A MOIST PLUME
THAT EXTENDS OVER NORTHERN MISSOURI INTO MINNESOTA. THE MAIN
THUNDERSTORM ACTIVITY WILL CONTINUE TO DEVELOP ALONG AND JUST AHEAD
OF NEARLY STATIONARY FRONTAL BOUNDARY OVER THE NORTHERN PLAINS.
EXPECT THUNDERSTORMS TO WANE DOWN OVERNIGHT OVER CENTRAL MN...AND
PERSIST OVER WESTERN MINNESOTA THROUGH SATURDAY MORNING. BASES OF
THE THUNDERSTORMS WILL BE AT OR ABOVE 4000 FEET AGL. BY MID
AFTERNOON SATURDAY...EXPECT MORE WIDESPREAD THUNDERSTORMS OVER MUCH
OF WESTERN MN...AND OVER THE EAST CENTRAL MN AND WESTERN
WISCONSIN...MAINLY AFTER MIDNIGHT TOMORROW NIGHT. WEATHER CONDITIONS
WILL REMAIN VFR FOR THE MOST PART...EXCEPT IN AND NEAR THE VICINITY
OF THUNDERSTORMS. SOUTH-SOUTHEAST WINDS INCREASING TO 20 TO 30 KNOTS
OVER EASTERN HALF OF THE FORECAST AREA SATURDAY. WINDS SHIFTING TO
THE NORTHWEST OVER WESTERN MN DURING THE AFTERNOON.
KMSP...VFR CONDITIONS PREVAILING THROUGH SATURDAY AFTERNOON/EVENING.
SCATTERED THUNDERSTORMS DEVELOPING DURING THE EVENING...WITH
THUNDERSTORMS BECOMING MORE LIKELY AROUND MIDNIGHT AND OVERNIGHT
SATURDAY NIGHT. SOUTH WINDS INCREASING TO 15 TO 25 KNOTS BY MID
MORNING SATURDAY.
OUTLOOK...
SAT NIGHT-SUN...SHRA/TSRA LIKELY WITH BRIEF MVFR/IFR POSSIBLE AS A
COLD FRONT PUSHES THROUGH.
MON-TUE...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/JVM
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1132 PM CDT FRI MAY 18 2012
.DISCUSSION...
MOSTLY SUNNY SKIES AND STRONG SOUTHERLY WINDS ACROSS THE UPPER
MIDWEST AHEAD OF A SURFACE TROUGH LOCATED OVER THE HIGH PLAINS
ALLOWED FOR NEAR RECORD WARMTH THIS AFTERNOON IN MINNESOTA AND
WISCONSIN. THE TROUGH OF LOW PRESSURE WILL GRADUALLY SLIDE
EASTWARD IN RESPONSE TO THE UPPER LEVEL FORCING...LEADING TO
SHOWERS AND THUNDERSTORMS CHANCES FOR THE WEEKEND. THERE WILL BE A
BRIEF DRY PERIOD MONDAY AND TUESDAY...WITH ON AND OFF THUNDERSTORM
CHANCES RETURNING FOR THE LATTER HALF OF THE PERIOD.
TODAY THROUGH SUNDAY...
LATEST WATERVAPOR IMAGERY COMBINED WITH 500MB HEIGHTS AND WINDS
SHOWED A BROAD LONGWAVE ACROSS THE GREAT BASIN...WITH UPPER LEVEL
DIVERGENCE DOWNSTREAM OVER THE HIGH PLAINS. THIS DIVERGENCE CAN BE
SEEN IDENTIFIED BY BOTH THE WIDESPREAD CLOUD FIELD AND SURFACE
PRESSURE TROUGH OVER THE HIGH PLAINS OF EASTERN MONTANA AND THE
WESTERN DAKOTAS. WITHIN THIS FLOW WERE A FEW FEATURES OF INTEREST.
THE FIRST OF WHICH IS A SHORTWAVE CROSSING THE MISSOURI RIVER
VALLEY INTO WESTERN IOWA. AN ADDITIONAL WAVE IS OFF THE BRITISH
COLUMBIA COAST...ALONG WITH A FEW EMBEDDED SHORTAVES IN THE
LONGWAVE THROUGH NEAR THE 4 CORNERS REGION. THE FIRST WAVE IS
ENOUGH TO SPARK A FEW ISOLATED SHOWERS ACROSS THE SOUTHWESTERN
CWA...AS INDICATED BY THE LAST FEW HRRR RUNS...AND CU FIELD. THE
MAIN CHANCE FOR PRECIP WILL BE LATER TOMORROW BEGINNING OUT WEST
AND SPREADING ACROSS THE THE REGION FOR SATURDAY NIGHT INTO
SUNDAY. LARGE SCALE ASCENT ASSOCIATED WITH THE UPPER LEVEL TROUGH
WILL BEGIN TO OVERTAKE THE REGION...WITH A FEW FOCUSED AREAS OF
PRECIP AS 3 DIFFERENT IDENTIFIABLE SHORTWAVES MOVE ACROSS THE
REGION. IS LOOKS LIKE THE BEST CHANCE FOR RAIN WILL BE SATURDAY
NIGHT INTO SUNDAY MORNING...AND HAVE INCREASED THE POPS AND QPF
DURING THIS TIME FRAME. FORECAST SOUNDINGS SHOW SOME DIRECTIONAL
SHEAR...BUT OVERALL THE WINDSPEEDS ARE LESS THAN 50KTS. THE SHEAR
INCREASES SATURDAY NIGHT AS THE LOW LEVEL JET STRENGTHENS...BUT
THE UPPER LEVEL WINDS REMAIN LESS THAN 50KTS. SOUNDINGS ALSO
INDICATE 1500 TO 2000 J/KG OF CAPE. SO BOTTOM LINE IS THE
POTENTIAL FOR SEVERE WEATHER DOES EXIST...BUT IT SHOULD BE
SPORADIC IN NATURE. IT LOOKS LIKE WE SHOULD SEE SOME GOOD SOAKING
RAINS WITH MULTIPLE ROUNDS OF PRECIP AS EACH WAVE MOVES
THROUGH
MONDAY THROUGH FRIDAY....DRY WEATHER IS EXPECTED AS HIGH PRESSURE
WILL BUILD ACROSS THE REGION FOR MONDAY AND TUESDAY. ON WEDNESDAY
A POWERFUL 120-140KT JET WILL CROSS THE WEST COAST AND MOVE
INLAND. AS IT DIGS OVER THE WESTCENTRAL US...IT WILL TAKE ON A
NEGATIVE TILT. THIS SETUP WILL DEVELOP A CYCLONE ACROSS THE HIGH
PLAINS...AND HAS THE POTENTIAL TO PRODUCE SOME SEVERE WEATHER FOR
THE LATTER HALF OF NEXT WEEK OVER THE GREAT PLAINS REGION. IT IS
TOO EARLY TO TELL THE EXACT TIMING AND PLACEMENT OF SEVERE
STORMS...BUT AS OF NOW CHOSE TO GO WITH A BLEND OF THE
GFS...ECMWF...AND PREVIOUS FORECAST...AND HAVE CHANCE POPS
THROUGHOUT THE EXTENDED PERIOD.
&&
.AVIATION.../06Z TAF ISSUANCE/
OVER THE NEXT 48 HOURS...THUNDERSTORM CHANCES WILL BE THE MAIN
FORECAST CHALLENGE. ONGOING THUNDERSTORM ACTIVITY WAS ASSOCIATED
WITH AN UPPER LEVEL DISTURBANCE THAT HAD MOVE INTO MN LATE FRIDAY
AFTERNOON. THE THUNDERSTORMS CONTINUE TO DEVELOP ALONG A MOIST PLUME
THAT EXTENDS OVER NORTHERN MISSOURI INTO MINNESOTA. THE MAIN
THUNDERSTORM ACTIVITY WILL CONTINUE TO DEVELOP ALONG AND JUST AHEAD
OF NEARLY STATIONARY FRONTAL BOUNDARY OVER THE NORTHERN PLAINS.
EXPECT THUNDERSTORMS TO WANE DOWN OVERNIGHT OVER CENTRAL MN...AND
PERSIST OVER WESTERN MINNESOTA THROUGH SATURDAY MORNING. BASES OF
THE THUNDERSTORMS WILL BE AT OR ABOVE 4000 FEET AGL. BY MID
AFTERNOON SATURDAY...EXPECT MORE WIDESPREAD THUNDERSTORMS OVER MUCH
OF WESTERN MN...AND OVER THE EAST CENTRAL MN AND WESTERN
WISCONSIN...MAINLY AFTER MIDNIGHT TOMORROW NIGHT. WEATHER CONDITIONS
WILL REMAIN VFR FOR THE MOST PART...EXCEPT IN AND NEAR THE VICINITY
OF THUNDERSTORMS. SOUTH-SOUTHEAST WINDS INCREASING TO 20 TO 30 KNOTS
OVER EASTERN HALF OF THE FORECAST AREA SATURDAY. WINDS SHIFTING TO
THE NORTHWEST OVER WESTERN MN DURING THE AFTERNOON.
KMSP...VFR CONDITIONS PREVAILING THROUGH SATURDAY AFTERNOON/EVENING.
SCATTERED THUNDERSTORMS DEVELOPING DURING THE EVENING...WITH
THUNDERSTORMS BECOMING MORE LIKELY AROUND MIDNIGHT AND OVERNIGHT
SATURDAY NIGHT. SOUTH WINDS INCREASING TO 15 TO 25 KNOTS BY MID
MORNING SATURDAY.
OUTLOOK...
SAT NIGHT-SUN...SHRA/TSRA LIKELY WITH BRIEF MVFR/IFR POSSIBLE AS A
COLD FRONT PUSHES THROUGH.
MON-TUE...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON MS
1030 AM CDT SAT MAY 19 2012
.UPDATE...
A MOSTLY DRY FORECAST STILL LOOKS ON TRACK FOR THIS AFTERNOON...BUT HAVE
ADDED MENTION OF ISOLATED TSTMS TO THE FORECAST BASED ON MORNING KJAN
SOUNDING AND LATEST LOCAL-WRF AND HRRR GUIDANCE. EVEN THOUGH SYNOPTIC
FEATURES CONTROLLING CONVECTIVE POTENTIAL TODAY ARE SUBTLE...WEAK
CYCLONIC MID LEVEL FLOW IS IN PLACE WITH H500 TEMPERATURES ~ -12 C
AND ACCAS IS APPARENT OVER SOUTHWEST MS. DEEP LAYER MOISTURE IS
LIMITED WITH PRECIPITABLE WATER ~1.2 IN...BUT SFC DEWPOINTS AROUND
60F AND SFC TEMPS APPROACHING 90F WILL YIELD SFC-BASED CAPE EXCEEDING
2000 J/KG. HIGH RESOLUTION GUIDANCE SHOWING STRAY TSTM POTENTIAL
LOOKS REASONABLE AND WILL RAISE POPS SLIGHTLY. SHOULD A FEW TSTMS
DEVELOP...30-40 MPH WIND GUSTS WOULD BE A POSSIBILITY GIVEN DEEP SUB-
CLOUD LAYER AND STEEP LOW LEVEL LAPSE RATES DCAPE VALUES > 1000 J/KG.
AS SUGGESTED EARLIER THIS MORNING...THE AREAS ALONG AND NW OF THE
NATCHEZ TRACE PARKWAY ARE MOST FAVORABLE FOR GETTING STORMS. THE
UPDATED AVIATION DISCUSSION IS BELOW. /EC/
&&
.PREV DISCUSSION... /ISSUED 359 AM CDT SAT MAY 19 2012/
DISCUSSION...SHORT TERM(TODAY THROUGH SUNDAY NIGHT) THIS WEEKEND
WILL BE CHARACTERIZED BY WARM TEMPERATURES AND MAINLY DRY CONDITIONS.
THE REGION SITS UNDER HIGH PRESSURE AT THE SFC WITH A DEVELOPING LOW
PRESSURE SYSTEM ACROSS THE PANHANDLE OF TEXAS. ALOFT...THE REGION
SITS BETWEEN BROAD TROUGHING TO THE EAST AND BUILDING RIDGING TO THE
WEST.
CONDITIONS TODAY AND SUNDAY WILL BE SIMILAR TO PREVIOUS DAYS WITH
CONTINUED WARM SUMMERLIKE TEMPERATURES...PERHAPS JUST A DEGREE OR
TWO WARMER EACH DAY INTO THE UPPER 80S AND LOWER 90S. RAIN CHANCES
WILL BE RATHER SLIM GIVEN INCREASED RIDGING IN THE WEST...LOW
MOISTURE PER MODEL PW VALUES(THOUGH THAT HAS NOT SEEMED TO MATTER
THE LAST FEW DAYS WITH VALUES LESS THAN 1 INCH AND STILL GENERATING
SHOWERS)...AND NO DISCERNIBLE FORCING MECHANISM OTHER THAN DAYTIME
HEATING. I CANNOT COMPLETELY RULE OUT SOME RAIN SHOWERS BUT
PINPOINTING EXACTLY WHERE WILL BE DIFFICULT. SOME WRF AND HI-RES
MODELS INDICATE MORE SHOWER ACTIVITY IN THE WEST THIS AFTERNOON BUT
THIS IS ALSO WHERE THE BETTER RIDGING EXISTS. OVERNIGHT LOWS WILL BE
IN THE UPPER 50S/LOWER 60S ACROSS THE REGION.
COME SUNDAY NIGHT...A COLD FRONT WILL CONTINUE TO MAKE ITS WAY SOUTH
TOWARD THE AREA. MOST OF THE RAIN SHOULD REMAIN OUT OF THE CWA
THROUGH THE NIGHT BUT CLOSER TO DAYBREAK THERE COULD BE SOME SLIGHT
CHANCES FOR THE DELTA AND HAVE INCREASED POPS IN THIS REGION JUST A
LITTLE TO INTRODUCE SLIGHT CHANCE WORDING FOR THE PRE-DAWN HOURS./28/
LONGER TERM(MONDAY THROUGH SATURDAY)...SEVERAL FACTORS COMING
TOGETHER FOR AT LEAST DECENT RAIN CHANCES MONDAY THROUGH TUESDAY TO
START THE WORK WEEK. A MID-UPPER LEVEL TROUGH DRIVES SEWD DOWN THE MO
RIVER VALLEY INTO THE TN VALLEY BY MONDAY NIGHT. THE TROUGH PUSHES AN
AXIS OF 1.5 INCH PWAT AIR ALONG THE INCOMING FRONT THAT COMBINES WITH
14-1600J/KG MLCAPES AND NEAR 7C 7-500MB LAPSE RATES FOR A COUPLE OF
ROUNDS OF SCATTERED TSRA MOSTLY TRIGGERED BY DAYTIME HEATING. THE
FIRST ROUND GETS GOING ACROSS THE I-40 CORRIDOR EARLY MONDAY MORNING
AND SAGS INTO OUR NRN CWFA BY MIDDAY WHEN K INDEXES REACH THE M30S.
RATHER WEAK LOW AND MID LEVEL FLOW OF 15-25KTS WILL LIMIT INTENSITIES
OF THE THESE SEWD- MOVING STORMS HOWEVER INTERACTING PREFRONTAL
BOUNDARIES IN A RIBBON OF 330K THETA E 850MB AIR COULD PRODUCE A FEW
STRONG STORMS MONDAY AFTERNOON GENERALLY N OF I-20. WILL MENTION THIS
POTENTIAL IN THE HWOJAN.
THEN...THE LEFTOVER ACTIVITY GRADUALLY WEAKENS MONDAY NIGHT BUT AT
LEAST SOME SHRA PROBABLY PERSISTING. ONCE TUESDAY ARRIVES...THE BEST
INSTABILITY REDEVELOPS ACROSS OUR SRN SECTIONS MAINLY S OF HIGHWAY 84
DURING THE MIDDAY AND AFTERNOON HOURS. THE COOLEST DAYTIME MAXES IN
THE M-U80S FOR THE COMING WEEK SHOULD OCCUR AND AS A RESULT...WILL
KEEP HIGHER POPS SHIFTED SWD TO THOSE LOCATIONS WITH THE FRONT
PUSHING ALL THE WAY TO NEAR THE COAST TUESDAY EVENING. DRYING AIR
SINKS INTO OUR N PORTIONS WHERE PWATS DROP BELOW 1 INCH LATE TUESDAY
THROUGH TUESDAY NIGHT.
THE AXIS OF HIGHER PWATS NEAR 1.4 INCHES PIVOTS BACK INTO THE REGION
WEDNESDAY AFTERNOON HELPING TO SET OFF AT LEAST ISOLATED SHRA/TSRA.
THE RETURNING WARM FRONT FEATURES NEAR 2K J/KG MLCAPES AND 335K THETA
E 850MB AIR BUT GENERALLY EVEN WEAKER WIND PROFILES. WILL KEEP SMALL
POPS FOR DAYTIME HEATING OF THE MOISTURE RETURN AS LOW LEVEL
CONVERGENCE REMAINS WEAK. THEREAFTER...BUILDING MID LEVEL RIDGE
ACROSS THE MID SOUTH AND TN VALLEY YIELDS 592DM 500MB HEIGHTS AND
WARMING LOW LEVELS THAT PUSH 850MB TEMPS TO THE 17-19C RANGE FRIDAY
AND SATURDAY. OVERNIGHT LOWS WILL STAY PREDOMINANTLY IN THE 60S WHILE
EVEN MORE DAYTIME LOWER 90S SHOULD BE IN THE PICTURE JUST IN TIME
FOR THE MEMORIAL DAY WEEKEND./40/
&&
.AVIATION...ISOLATED SHOWERS NOT OUT OF THE QUESTION AGAIN TODAY BUT
CONFIDENCE IN AFFECTING A TAF SITE IS LOW AND WILL NOT BE INCLUDED IN
THE FORECAST AT THIS POINT. EXPECT SCATTERED CUMULUS BASES DEVELOPING
MIDDAY THROUGH AFTERNOON IN THE 6 TO 9 KFT RANGE. WINDS WILL BE FROM
THE EAST THROUGH SOUTH AT 5 TO 10 KTS. TONIGHT WILL SEE SOME MORE
SCATTERED MIST (MVFR LEVEL) LATE THAT WILL DISSIPATE BY 9 AM SUNDAY
MORNING. CHANCES FOR RAIN SUNDAY AFTERNOON AGAIN APPEAR GENERALLY LOW
WITH WINDS LIGHT. /BB/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1216 AM CDT SAT MAY 19 2012
.AVIATION...
COLD FRONT WILL CONTINUE TO MOVE EAST ACROSS WESTERN AND CENTRAL
NEBRASKA THROUGH THE EARLY MORNING HOURS. THUNDERSTORMS WILL MOVE
OUT OF WESTERN NEBRASKA THROUGH 1909Z. ABUNDANT LOW LEVEL MOISTURE
BEHIND THE FRONT WILL BRING AREAS OF PATCHY DRIZZLE WITH MVFR
CEILINGS AFTER SUNRISE AND POSSIBLY SOME IFR CEILINGS AT BOTH KLBF
AND KVTN TAF SITES. STRONG NORTHWEST WINDS WILL CONTINUE BEHIND THE
FRONT THROUGH THE DAY. AS NEXT MID LEVEL WAVE PUSHES THROUGH THIS
AFTERNOON CEILINGS TO RISE WITH SHOWERS DEVELOPING. SHOWERS WILL END
THROUGH EARLY EVENING WITH WINDS SUBSIDING.
&&
.PREV DISCUSSION... /ISSUED 842 PM CDT FRI MAY 18 2012/
UPDATE...
UPDATED WIND FORECAST. WEATHER FORECAST ON TRACK. THUNDERSTORMS
NOT PUTTING OUT MUCH IN WAY OF RAIN BUT SOME WIND AND MOSTLY SMALL
HAIL. NUMEROUS LIGHTNING STRIKES WITH CLUSTER IN GARDEN GRANT AND
ARTHUR COUNTIES. LOOKS TO BE JUST ENOUGH TREAT TO DIMINISH FIRE
THREAT.
&&
.PREV DISCUSSION... /ISSUED 842 PM CDT FRI MAY 18 2012/
AVIATION...
STRONG STORMS MOVING ACROSS WESTERN NEBRASKA THIS EVENING. HAVE
INCLUDED TEMPO GROUP FOR KVTN THROUGH 4Z. NORTHWEST WINDS BUILDING
INTO THE NORTHWEST PANHANDLE. FROPA EXPECTED AT KVTN AROUND 1906Z
AND KLBF 1911Z. STRATUS AND CEILINGS LOWERING INTO THE IFR CATEGORIES
WITH DRIZZLE EXPECTED TO BUILD IN AFTER FROPA AND THEN LIGHT TO
MODERATE RAIN DEVELOPING THROUGH THE AFTERNOON WITH CEILINGS LIFTING
INTO MVFR.
PREV DISCUSSION... /ISSUED 330 PM CDT FRI MAY 18 2012/
DISCUSSION...
A POWERFUL UPPER LEVEL DISTURBANCE ACROSS COLO WILL MOVE SLOWLY
EAST TONIGHT AND SATURDAY PRODUCING SCATTERED TSTMS...MAINLY
ACROSS NORTH AND WEST PARTS OF THE FCST AREA WHICH WILL BE CLOSER
TO THE BEST DYNAMICS. SUPER ENSEMBLE FCST QPF SUGGESTS AROUND 1/4 INCH
OF RAIN NEAR NORTH PLATE AND CLOSE TO 3/4 OF AN INCH NEAR VALENTINE.
FOR THIS EVENING THE THREAT OF HIGH BASED TSTMS CAPABLE OF GUSTY
OR PERHAPS ISOLATED DAMAGING DOWNBURSTS WILL CONTINUE AS SFC RH IS
OPERATING BELOW 40 PERCENT. ONCE THE COLD FRONT SWEEPS SOUTH
LATER TONIGHT THE WIND THREAT SHOULD DIMINISH. THE ECM CONTINUES
TO BE SLOWER WITH COLD FRONT HOLDING IT UP SOME SATURDAY AFTERNOON
ACROSS THE ERN ZONES. THIS WAS INCORPORATED IN THE TEMP FORECAST
FOR HIGHS IN THE 70S EAST...BUT UPPER 50S TO AROUND 60 WEST.
THE UPPER LEVEL DISTURBANCE SHOULD CLEAR THE FCST AREA SATURDAY
NIGHT WITH STRONG HIGH PRESSURE BUILDING IN SUNDAY FOR NEARLY
CLEAR SKIES AND HIGHS IN THE 60S TO AROUND 70S. THE SFC HIGH WILL
MOVE OFF EAST QUICKLY MONDAY WITH SOUTHERLY RETURN FLOW DEVELOPING
AND A STRONG THERMAL RIDGE DEVELOPING ACROSS THE HIGH PLAINS AND
CNTL ROCKIES BY LATE MONDAY AFTERNOON. THIS THERMAL RIDGE SHOULD
MIGRATE EAST INTO THE NEB PANHANDLE TUESDAY AFTERNOON. MIX DOWN
TOOLS FROM 700 MB SUGGESTS HIGHS IN THE LOWER 90S. FOR NOW 80S
WILL OPERATE. ALL MODELS EXCEPT THE SLOWER AND VERY WARM GEM THEN
SWEEP A COLD FRONT THROUGH WEDNESDAY LOWERING TEMPS ABOUT 10
DEGREES. THE FRONT WILL THEN LIFT SLOWLY NORTH THROUGH KS AND
BECOME STATIONARY ACROSS SWRN NEB FRIDAY. ALL ALONG A DEEP UPPER
LEVEL TROF WILL DROP INTO THE WRN U.S. AND WINDS ALOFT WILL
BECOME SOUTHWEST AND INCREASE IN SPEED. SFC LOW PRESSURE WILL DEEPEN TO
BELOW 990 MB ACROSS WRN KS SUPPORTING WINDY CONDITIONS...SHARP
MOISTURE GRADIENTS AND A STRONG CAP...PERHAPS AS STRONG AS 12C
ACROSS SRN NEB. GIVEN THE FAST FLOW ALOFT AND FOCUS OF THE SFC
LOW...ISOLATED AND LOW-CHC POPS ARE IN PLACE LATE TUESDAY THROUGH
THURSDAY.
FIRE WEATHER...
A FAIRLY SHARP DRYLINE HAS FORMED NEAR WRAY AND HOLYOKE COLO THIS
AFTN WHERE RH IS RUNNING 11 TO 15 PERCENT. THE RUC SHOWS THIS
DRYLINE PUSHING EAST INTO SWRN NEB LATE THIS AFTERNOON AS THE SFC
LOW MOVES EAST TO NEAR BURLINGTON COLO. THE RED FLAG WARNING WILL
CONTINUE IN EFFECT THIS EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
158 AM EDT SAT MAY 19 2012
.SYNOPSIS...
STALLED LOW PRESSURE WILL CONTINUE TO BRUSH THE COAST...BRINGING
RAIN AND A FEW THUNDERSTORMS INTO THE MIDDLE OF NEXT WEEK. LOW
PRESSURE WILL FINALLY BEGIN TO MOVE NORTHEAST AND AWAY FROM THE AREA
WITH DRIER WEATHER FOR THE END OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM FRIDAY...LATEST HRRR CONSOLIDATES THE BROAD SFC LOWS
OFF THE CAROLINA COASTS TO 1 INTENSE CONCENTRIC LOOKING LOW JUST
OFFSHORE FROM THE CAROLINA COASTS OVERNIGHT INTO SATURDAY. LATEST
NAM ALSO FAVORS THIS SOLUTION. SO WITH EGG ON MY FACE...HAVE UPDATED
THE ZONES WITH STRONGER NORTH TO NORTHEAST ACROSS THE FA WITH THE
ADDITION OF GUSTS UP TO AND OVER 20 KT ACROSS THE COASTAL COUNTIES.
BASED ON SURROUNDING 88DS INCLUDING OURS...THE CURRENT LOCATION OF
THE SFC LOW IS ROUGHLY 85 MILES SOUTHEAST OF BALD HEAD ISLAND. LIGHT
RAIN WILL CONTINUE TO TRACK WESTWARD AND PLAGUE THE COASTAL
COUNTIES...WITH THE MAIN CONVECTION STAYING NEAR THE SFC LOW ITSELF.
DO NOT ANTICIPATE ANY ONSHORE MOVEMENT OF THIS CONVECTION.
IN ADDITION TO UPPING THE WINDS...HAVE LOWERED TONIGHTS MINS BY
ATLEAST A CATEGORY. THIS BASED ON LATEST TEMP AND DEWPOINT TRENDS
AND A QUICK LOOK-SEE AT THE 00Z MODEL GUIDANCE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 245 PM FRIDAY...BROAD UPPER LOW NOW CENTERED DIRECTLY OVER THE
COASTAL CAROLINAS WILL BE THE DRIVER FOR THE WEATHER IN THE SHORT
TERM. VARIOUS MID-RANGE GUIDANCE IN GOOD ACCORD AS TO THE CHARACTER
OF THE UPPER LOWS MOVEMENT...A SLOW SPIRAL OFFSHORE ON
SATURDAY...THEN A DRIFT TO THE NORTHWEST AND ONSHORE ON SUNDAY.
GUIDANCE A LITTLE LESS CLEAR AS TO THE PRECIPITATION CONSEQUENCES
AND SURFACE REFLECTIONS FOR THIS FEATURE...ESPECIALLY ON SATURDAY.
NAM IS THE WET SOLUTION WHILE ECMWF AND GFS KEEP THE EASTERN
CAROLINAS ON THE DRY SIDE ON SATURDAY. HAVE LEANED MORE TOWARDS THE
CONSENSUS DRYER SOLUTION FOR SATURDAY...WITH ISOLATED SHOWERS FOR
THE COASTAL COUNTIES AND MINIMAL QPF...YET WITH EXTENSIVE CLOUD
COVER. MORE AGREEMENT BETWEEN GUIDANCE AND HIGHER CONFIDENCE THAT
SUNDAY WILL BE THE WETTER DAY AS THE UPPER LOW AND ITS SURFACE
REFLECTION TRACK BACK NORTHWEST OVER LAND. OMEGA FIELDS SUGGEST WE
COULD ALSO SEE THUNDERSTORMS DEVELOP SUNDAY AFTERNOON AND EVENING AS
CORE OF UPPER LOW MOVES OVERHEAD.
EXTENSIVE CLOUDINESS ON BOTH DAYS AND A STEADY NORTH TO
NORTHEASTERLY FLOW THROUGH THE PERIOD WILL HELP KEEP DAYTIME
TEMPERATURES BELOW NORMAL OVER THE WEEKEND...WITH HIGHS IN THE LOWER
TO MID 70S ALONG THE COAST AND MID TO UPPER 70S INLAND.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...MID TO UPPER LOW SITTING DIRECTLY OVERHEAD
EARLY MONDAY WILL LIFT OFF TO THE NORTHEAST MON NIGHT NIGHT INTO
TUES AS ANOTHER SHORTWAVE TROUGH DIGS DOWN OVER THE SOUTHEAST. THIS
TROUGH WILL PUSH A COLD FRONT THROUGH AREA TUES NIGHT INTO WED.
DEPENDING ON TIMING OF EXITING LOW...WE SHOULD SEE A PERIOD OF
SUBSIDENCE BEFORE NEXT SYSTEM COMES. AT THIS POINT IT LOOKS LIKE
TUES MORNING MAY BE DRY WITH A BRIEF PERIOD OF DEEPER NW FLOW AND
SUBSIDENCE ON BACK END OF LOW. PCP WATER DROPS FROM 1.8 INCHES DOWN
TO JUST BELOW 1.5 INCHES BEFORE INCREASING AGAIN IN CONVECTION AHEAD
OF COLD FRONT LATE TUES INTO EARLY WED. ONCE THIS FRONT CLEARS THE
COAST ON WEDNESDAY...IT LOOKS LIKE WEAK HIGH PRESSURE WILL SETTLE
OVER THE AREA THURS AND FRI WITH ONLY LOCALIZED SEA BREEZE
CONVECTION POSSIBLE. DEEP DRY NORTHERLY FLOW ALOFT WILL VEER AROUND
THURS THROUGH FRI WITH MOISTURE MAINLY CONFINED TO 5K FT AND BELOW
FROM THURS INTO NEXT WEEKEND.
WITH CLOUDS AND DEEP LAYER MOISTURE OVER AREA THE FIRST HALF OF THE
WEEK...AND H5 HEIGHTS AROUND 575 DEM...EXPECT TEMPS TO REMAIN BELOW
NORMAL UNTIL LOW LIFTS OFF AND FRONT PASSES BY ON WED. WARMING TREND
WILL BEGIN WED WITH TEMPS REACHING ABOVE NORMAL AS RIDGE BUILDS OVER
THE CAROLINAS FRI THROUGH NEXT WEEKEND.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...EXPECT VFR THROUGH VALID PERIOD...WITH EXCEPTION OF
POTENTIAL FOR LOW MVFR CEILINGS EARLY THIS MORNING AT KILM/KMYR/
KCRE.
A STALLED AREA OF LOW PRESSURE WILL CONTINUE TO SPIN OFF THE
CAROLINA COAST. RAIN WILL CONTINUE TO MOVE ONSHORE...WITH WIND GUSTS
NEAR 20 KT FOR THE COASTAL TERMINALS. THE INLAND TERMINALS WILL
REMAIN DRY WITH OVC MID LEVEL CLOUDS TENDING TO THIN THROUGH THE DAY.
THROUGHOUT THE DAY...MAY SEE SOME BREAKS IN THE CLOUDS...BUT OVERALL
EXPECT SCT/BKN MID TO HIGH CLOUDS TO LINGER AS LOW PRESSURE STAYS
JUST OFFSHORE. AFTER SUNSET...GUSTS WILL SUBSIDE ALLOWING FOR
NORTHEAST FLOW AOB 10 KTS TO PREVAIL.
EXTENDED OUTLOOK...MORNING STRATUS POSSIBLE THROUGH SUNDAY...MOSTLY
OVER THE NORTHERN HALF OF THE CWA
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 11 PM FRIDAY...STRONG SCA FOR ALL WATERS CONTINUES THROUGH
SATURDAY AFTERNOON. HAVE UPPED WINDS ACROSS ALL WATERS BASED ON THE
LATEST NAM/HRRR GUIDANCE WHICH ILLUSTRATE A CONSOLIDATED LOW. THE
KLTX 88D INDICATES THIS LOW NOW 85 MILES SOUTHEAST OF BALD HEAD
ISLAND. THE SFC PRESSURE PATTERN AND GRADIENT WILL YIELD NORTH TO
NORTHEAST WINDS 15 TO 25 KT WITH GUSTS UP TO 30 KT INTO SATURDAY
AFTERNOON. THE LATEST HRRR WIND OUTPUT NO LONGER LOOKS OVERDONE WITH
30 TO 40 KT SUSTAINED WINDS OFFSHORE AND CLOSER TO THE SFC LOW.
CORRESPONDING SEAS WILL RANGE FROM 4 TO 7 FT...UP TO 8 AND 9 FT
ACROSS THE OUTER WATERS OFF CAPE FEAR.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 245 PM FRIDAY...A GENERALLY NORTHERLY FLOW WILL PREVAIL
THROUGH THE PERIOD AS A TROUGH OF LOW PRESSURE LINGERS EAST OF THE
WATERS. LOW PRESSURE CENTERS DEVELOPING WITHIN THIS TROUGH WILL
TIGHTEN GRADIENTS ENOUGH TO BUMP WINDS UP INTO THE 15 TO 20 KT RANGE
THROUGH DAYTIME SUNDAY. WINDS WILL MODERATE LATER ON SUNDAY AS A LOW
PRESSURE SYSTEM MOVES OVERHEAD. SEAS WILL BE HIGHEST EARLIEST IN THE
PERIOD...WITH 6 FOOTERS LIKELY OVER THE OUTER FRINGES OF OUR WATERS.
WILL KEEP SMALL CRAFT ADVISORY HEADLINES FOR DAYTIME SATURDAY AS A
RESULT. OTHERWISE...SEE 3 TO 5 FT SEAS FOR MUCH OF THE SHORT
TERM...WITH SEAS SUBSIDING LATE ON SUNDAY AS WINDS MODERATE.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...WINDS MAY BE A BIT TRICKY ON MONDAY AS LOW
PRESSURE SITS OVERHEAD. MAY RETROGRADE JUST ENOUGH TO THE WEST TO
PRODUCE A LIGHT S-SW FLOW. THIS LOW WILL LIFT OFF TO THE NORTHEAST
LATE MON INTO EARLY TUES WITH A BRIEF VEERING OF THE WINDS BEFORE
NEXT SYSTEM MOVES IN. THE WINDS SHOULD BACK AROUND THROUGH TUES AND
INCREASE SLIGHTLY OUT OF THE W-SW AS COLD FRONT APPROACHES FROM THE
NW. LOOKS LIKE THIS COLD FRONT WILL NOT MAKE A CLEAN SWEEP AND MAY
BECOME WASHED OUT ACROSS THE AREA WITH WEAK GRADIENT FLOW SETTING UP
BY THURS. WINDS WILL MOST LIKELY BE DRIVEN MORE BY LAND/SEA BREEZE
BY THURS. OVERALL EXPECT WINDS 10 KTS OR LESS THROUGH MOST OF THE
PERIOD...EXCEPT UP TO 15 KTS IN TIGHTENED GRADIENT FLOW LATE TUES
THROUGH EARLY WED. SEAS WILL RUN 2 TO 3 FT EXCEPT ON TUES WHEN THEY
INCREASE UP AROUND 4 FT IN OUTER WATERS TUES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR AMZ250-252-
254-256.
&&
$$
NEAR TERM...DCH
SHORT TERM...REK
LONG TERM...RGZ
AVIATION...RJD/SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 AM EDT SAT MAY 19 2012
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND SOUTHWARD INTO THE CENTRAL CAROLINAS
THROUGH THE WEEKEND...WHILE A LOW PRESSURE SYSTEM STALLS OUT AND
MEANDERS JUST OFFSHORE THE CAROLINA COAST.
&&
.NEAR TERM /TODAY THROUGH SATURDAY NIGHT/...
AS OF 10 PM FRIDAY...
TONIGHT:
SURFACE HIGH PRESSURE CONTINUES TO BUILD/EXTEND INTO CENTRAL NC FROM
THE NORTHEAST THIS EVENING... WHILE A GENERALLY STACK LOW PRESSURE
SYSTEM IS LOCATED OFF THE COAST OF THE CAROLINAS. THIS SETUP AS
ALLOWED DRIER AIR IN THE LOW LEVELS OF THE ATMOSPHERE TO FILTER INTO
THE AREA IN MAINLY NORTH TO NORTHEASTERLY FLOW. MEANWHILE... MAINLY
HIGH LEVEL CLOUD COVER IS STREAMING INTO THE AREA ALOFT FROM SHOWERS
ANS STORMS THE OFFSHORE LOW PRESSURE SYSTEM. GIVEN THE RATHER DRY
AIR CONTINUING TO BUILD INTO THE AREA IN THE LOW LEVELS OF THE
ATMOSPHERE EXPECT DRY CONDITIONS FOR MOST IF NOT ALL OF THE CWA. THE
ONE EXCEPTION MAY BE FROM A FEW VERY LIGHT SHOWERS SKIRTING SOUTHERN
SAMPSON COUNTY THIS EVENING IN ASSOCIATED WITH THE OFFSHORE LOW.
HOWEVER... GIVEN THE LATEST RAP SOUNDINGS FOR SOUTHERN SAMPSON
COUNTIES STILL INDICATE A FAIRLY DRY SUB-CLOUD LAYER BELOW 750 MB
(WITH A DRYING TREND BELOW 750 MB EXPANDING THROUGHOUT THE EVENING)
WILL KEEP THE FORECAST DRY FOR THE ENTIRE AREA. THUS THE MAIN
FORECAST PROBLEM CONTINUES TO BE THE HIGH LEVEL CLOUD COVER AND THE
EFFECTS ON TEMPERATURES. HAVE INCREASED CLOUD COVER FROM THE
PREVIOUS FORECAST AND INCREASED LOW A DEGREE OR TWO... GIVEN CURRENT
OBSERVATIONAL DATA NAM AND GFS FORECAST SOUNDINGS. THIS YIELDS
GENERALLY PARTLY TO MOSTLY CLOUDY SKIES FOR A GOOD PART OF THE
NIGHT... WITH PERHAPS SOME MOSTLY CLEAR CONDITIONS ACROSS THE
WESTERN/NORTHWESTERN PIEDMONT. THUS... WILL GO WITH LOW TEMPS
GENERALLY IN THE LOWER TO MID 50S... WHICH IS NOW GENERALLY IN THE
MIDDLE OF THE STATISTICAL GUIDANCE RANGE.
SATURDAY AND SATURDAY NIGHT:
THE AFOREMENTIONED UPPER LEVEL LOW AND ATTENDANT SURFACE LOW ARE
PROGGED TO STALL JUST OFFSHORE THE CAROLINA COAST THROUGH 12Z SUNDAY
MORNING. MODEL GUIDANCE CONTINUES TO HAVE A DIFFICULT TIME WITH THE
PRECISE EVOLUTION OF THESE FEATURES...THOUGH NEITHER MODEL INDICATES
MORE THAN A TRACE OF PRECIP IN THE FAR EAST/SE COASTAL PLAIN THROUGH
SUNRISE SUNDAY MORNING. HOWEVER...THIS SYSTEM IS EXPECTED TO BECOME
MORE PROGRESSIVE DURING THE DAY SUNDAY...RETROGRADING ONSHORE INTO
EASTERN NC...AND IF THE SURFACE/UPPER LEVEL LOW RETROGRADE A BIT
SOONER THAN CURRENTLY PROGGED...LIGHT SHOWERS WOULD BE POSSIBLE EAST
OF THE I-95 CORRIDOR PRIOR TO SUNRISE SUNDAY MORNING. WITH THE ABOVE
IN MIND...WILL KEEP THE FCST DRY ON SATURDAY...AND WILL INDICATE A
SLIGHT CHANCE OF SHOWERS OR SPRINKLES IN THE COASTAL PLAIN AFTER
MIDNIGHT. THE AIRMASS ACROSS CENTRAL NC WILL VARY FROM VERY DRY IN
THE WESTERN PIEDMONT (0.50" PWAT AT GSO) TO MOIST IN THE COASTAL
PLAIN (PWAT 1.15" AT RWI) ON SATURDAY. EXPECT SUNNY OR MOSTLY SUNNY
SKIES IN THE WEST...AND PARTLY CLOUDY TO MOSTLY CLOUDY SKIES IN THE
EAST. EXPECT HIGHS ON SATURDAY TO BE SLIGHTLY WARMER THAN TODAY IN
THE WESTERN PIEDMONT (MID/UPPER 70S)...AND SIMILAR OR SLIGHTLY
COOLER THAN TODAY IN THE FAR EASTERN COASTAL PLAIN (LOWER 70S). LOWS
SAT NIGHT IN THE LOWER/MID 50S. -VINCENT
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 100 PM FRIDAY...
THE FORECAST WILL HINGE ON THE EVENTUAL FATE/EVOLUTION OF THE
MEANDERING CLOSED UPPER LOW AND ASSOCIATED LOW PRESSURE CENTER OFF
THE NORTH CAROLINA COAST. OVERALL...THE GUIDANCE ENVELOPE HAS
SHIFTED SLIGHTLY WESTWARD/INLAND FOR SUNDAY AND MONDAY...BUT THERE
REMAINS SIGNIFICANT SPREAD WITH THE TIMING AND HOW FAR INLAND THIS
SYSTEM WILL RETROGRADE.
IF CURRENT TRENDS HOLD UP...EXPECT THICKENING CLOUD COVER WITH
INCREASING RAIN CHANCES SUNDAY AFTERNOON/EVENING...AND CONTINUING
INTO THE DAY ON MONDAY AS THE EASTERLY ATLANTIC MARITIME FEED WILL
ADVECT HIGH PWATS ON THE ORDER 1.5-1.6"(2 SD ABOVE NORMAL)INLAND AS
THE CIRCULATION CENTER WOBBLES WESTWARD OVER THE FORECAST AREA.
EXPECT THAT WE WILL SEE A DIURNAL ENHANCEMENT IN POPS/CONVECTION...
SUNDAY AFTERNOON/EVENING AND AGAIN MONDAY AFTERNOON BEFORE THE
LOW BEGINS TO FINALLY TRANSLATE EASTWARD MONDAY EVENING/NIGHT WITH
THE APPROACH OF THE NORTHERN STREAM TROUGH FROM THE WEST. THERE
REMAINS TOO MUCH UNCERTAINTY AT THIS TIME TO DISCUSS IN DETAIL
ABOUT ANY SEVERE/HEAVY RAIN THREAT...BUT WILL NEED TO MONITOR
THE NEXT DAY OR TWO GIVEN RECENT HEAVY RAINS ACROSS CENTRAL AND
EASTERN NC. FOR THE SAME REASONS...WILL KEEP POPS IN THE SLIGHT TO
CHANCE CATEGORIES FOR NOW...WITH HIGHEST POPS IN THE EAST. WITH
TIME...BUT IF LATER MODEL RUNS START TO EXHIBIT BETTER CONTINUITY...
SUNDAY NIGHT AND INTO MONDAY COULD BE A WET PERIOD WITH LIKELY TO
CATEGORICAL POPS.
SEASONABLE TEMPERATURES SUNDAY THROUGH MONDAY...HIGHLY DEPENDENT ON
THE UPPER LOW AND ASSOCIATED RAIN CHANCES. GIVEN THE WESTWARD TREND
WITH THE LOW PRESSURE SYSTEM WILL NUDGE FORECAST HIGHS SUNDAY
AND MONDAY DOWN A BIT...HIGHS GENERALLY IN THE MID TO UPPER 70S.
LOWS 55 TO 60. -CBL
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 245 PM FRIDAY...
THERE ARE SOME PRETTY GLARING DIFFERENCES WITH THE TIMING AND
AMPLITUDE OF THE NEXT SHORTWAVE TROUGH AND ATTENDANT SURFACE FRONT
MOVING EAST THROUGH THE REGION DURING THE TUESDAY THROUGH
WEDNESDAY PERIOD. THE GFS IS UP TO ITS USUAL TRICKS/BIAS...
RACING THE OPEN WAVE TROUGH EASTWARD THROUGH THE AREA TUESDAY
EVENING/NIGHT...WHILE THE EC IS MORE SLOWER TO ADVANCE THE SYSTEM
EASTWARD...DEVELOPING INTO A CLOSED LOW INVOF OF THE OHIO/TN VALLEY
BEFORE FINALLY CROSSING THE AREA ON THURSDAY. UNTIL THERE IS BETTER
MODEL AGREEMENT WILL BROAD BRUSH SLIGHT TO SMALL CHANCE POPS ACROSS
THE AREA TUESDAY-WEDNESDAY WITH DRY CONDITIONS AFTERWORDS.
MODERATING TEMPERATURES IN THE LOW-LEVEL SWLY FLOW. HIGHS IN THE
LOWER TO MID 80S. LOWS IN THE 60S.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 140 AM SATURDAY...
HIGH CLOUDS ARE ABUNDANT OVER CENTRAL NC THIS MORNING AS A WEAK LOW
PRESSURE SYSTEM LINGERS OFF THE CAROLINA COAST. HOWEVER...
SIGNIFICANTLY DIRER AIR IS POURING IN FROM THE NORTHEAST AND
HELPING TO KEEP ANY STRATUS CONFINED TO THE COAST...THOUGH THE
STRATUS MAY WORK INLAND AND BE JUST EAST OF KFAY AND KRWI AROUND
12Z. VFR CONDITIONS ARE EXPECTED TO CONTINUE TODAY...WITH A
GENERALLY LIGHT NORTHEASTERLY WIND THAT MAY APPROACH 10KT IN THE
EAST. AS THE LOW PRESSURE OFFSHORE SLOWLY BEGINS TO STRENGTHEN
TONIGHT...LOW LEVEL MOISTURE IS FORECAST TO SURGE FURTHER WESTWARD.
BASED ON POOR AGREEMENT AMONG MODELS...THERE IS LOW CONFIDENCE IN
LOW CEILINGS REACHING KFAY AND KRWI BY 06Z SUNDAY MORNING...THOUGH
THE PROBABILITY OF MVFR AND IFR CEILINGS WILL BE INCREASING THROUGH
SUNDAY MORNING.
LOOKING AHEAD:
THERE WILL BE INCREASING CHANCES FOR SHOWERS AND LOW CEILINGS SUNDAY
AS A LOW PRESSURE SYSTEM DRIFTS WESTWARD ONSHORE SOMEWHERE OVER
NC/VA. THERE IS QUITE A BIT OF UNCERTAINTY REGARDING WHERE THE LOW
WILL TRACK AND EXACTLY WHEN POOR AVIATION CONDITIONS WILL BE MOST
WIDESPREAD...BUT CONDITIONS SHOULD GENERALLY BE WORSE OVER A MORE
PROLONGED PERIOD OVER EASTERN NC SUNDAY AND MONDAY. ANOTHER LOW
PRESSURE SYSTEM IS THEN FORECAST TO MOVE INTO THE AREA FROM THE WEST
ON TUESDAY...WITH CONTINUED UNSETTLED CONDITIONS POSSIBLE THROUGH
MIDWEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...BSD/VINCENT
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
125 AM EDT SAT MAY 19 2012
.SYNOPSIS...
A WARM AND TRANQUIL WEEKEND IS IN STORE FOR THE AREA AS A DEEP
LAYERED RIDGE OF HIGH PRESSURE MOVES ACROSS OHIO INTO INTERIOR NEW
ENGLAND BY LATER ON SUNDAY. WEAK EASTERLY FLOW AT THE SURFACE WILL
HOLD DEEPER MOISTURE AT BAY...BUT HUMIDITIES WILL BE ON THE
INCREASE OVER WHAT HAS BEEN EXPERIENCED THE PREVIOUS FEW DAYS. A
WEAKENING WEATHER SYSTEM SHIFTING THROUGH THE WESTERN GREAT LAKES
SUNDAY NIGHT WILL SLOW AS IT MOVES INTO THE OHIO VALLEY...BRINGING
THE NEXT THREAT OF SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
DESPITE VERY WEAK NEAR-SURFACE WIND FLOW...MOISTURE IS INCREASING
FROM SOUTHEAST TO NORTHWEST ACROSS THE FORECAST AREA AT THIS TIME.
WITH THE MOSTLY CALM WINDS AND CLEAR SKIES...SOME FOG SEEMS LIKELY
IN PRONE AREAS...AND PATCHY REDUCED VISIBILITIES ARE POSSIBLE
ELSEWHERE AS WELL. ADDED SLIGHTLY MORE LOW-ELEVATION FOG THAN THE
PREVIOUS FORECAST...AND MADE SOME MINOR ADJUSTMENTS TO MIN TEMPS
AS WELL.
PREVIOUS DISCUSSION >
AMPLE SUNSHINE AGAIN TODAY WITH LOW DEWPOINTS /30S AND
40S/...THANKS TO DEEP LAYERED RIDGE OF HIGH PRESSURE OVER THE
AREA. 18.19Z RUC ANALYSIS INDICATED A CLOSED-CONTOUR 580DM
ANTICYCLONE OVER NRN INDIANA...ATOP A CLOSED-CONTOUR 576DM CYCLONE
JUST OFF THE SOUTH CAROLINA COAST. NOT OVER STRONG/IMPRESSIVE
SYSTEMS...BUT THIS REX BLOCK TYPE STRUCTURE WILL CONTINUE TO
DOMINATE OUR WEEKEND WEATHER PATTERN...WITH WEAK EASTERLY FLOW OUT
OF A SURFACE HIGH PRESSURE SYSTEM IN NEW ENGLAND /RATHER BAGGY
PRESSURE GRADIENT/ CONTINUING TO HOLD DEEPER BOUNDARY LAYER
MOISTURE /60S DEWPOINTS/ WELL SOUTH AND WEST OF THE AREA.
IN THE UPCOMING 12-15 HOURS...EXPECT VERY LITTLE SYNOPTIC SCALE
CHANGE AS THE MID-LEVEL HIGH DRIFTS THROUGH NRN OHIO AND
STRENGTHENS SLIGHTLY WHILE THE LOW OVER THE WRN ATL ELONGATES SOME
BEGINS SPLITTING INTO TWO DISTINCT CYCLONIC CIRCULATION
CENTERS...ONE IN ERN GA AND THE OTHER OFF THE NC COAST.
VERY WEAK SFC FLOW WILL QUICKLY GO CALM THIS EVENING UNDER RAPIDLY
STRENGTHENING INVERSION AND DECOUPLING OF THE SHALLOWING BOUNDARY
LAYER. THIS SHOULD FOSTER A RAPID EVENING TEMP DROP WITH CLEAR
SKIES. RAN A GENERAL BLEND OF THE PREVIOUS FORECAST AND 12Z
ECMWF/GFS/NAM MOS...THOUGH TWEAKED A TOUCH DOWNWARD IN THE COOL
SPOTS GIVEN IDEAL RADIATIONAL COOLING REGIME. ALSO FOGGED UP THE
OHIO AND ADJACENT RIVER VALLEYS LATER IN THE NIGHT...AS BOUNDARY
LAYER MOISTURE FROM KY WILL BE SEEPING NWRD OVERNIGHT AS MINOR SLY
COMPONENT TO THE GENERAL EASTERLY FLOW WILL ALLOW AN INCREASE IN
LLVL MOISTURE. WOULD NOT BE SURPRISED IS FOG BECOMES A LITTLE MORE
WIDESPREAD THAN FORECAST ESP OVER NRN KY/SRN OH/SERN IND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
VERY LITTLE CHANGE TO THE PATTERN ALOFT ON SATURDAY...THOUGH THE
LOW LEVELS WILL BEGIN TO UNDERGO SOME MOISTURE ADVECTION...ESPECIALLY
ACROSS SRN/SWRN FORECAST AREA. 18.12Z WRF/GFS INDICATE LOWEST 1KM
SPECIFIC HUMIDITIES DOUBLING IN COMPARISON TO FRIDAY...SO BROUGHT
DEWPOINTS UP A BIT IN THE SOUTH/SOUTHWEST...PERHAPS NOT ENOUGH.
FEEL 18.12Z NAM-WRF SFC DWPTS ABOUT 10F TOO HIGH AS HAS BEEN A
PROBLEM THIS SPRING...SO DISCOUNTING THE RATHER STRONG INSTBY THAT
DEVELOPS UNDERNEATH THE MID LEVEL RIDGE SATURDAY AFTERNOON. EVEN
SO...ADDITIONAL MOISTURE AND A FAVORABLE LAPSE RATE WILL NO DOUBT
YIELD SOME DEEPER CUMULUS ACROSS THE SOUTH/SOUTHWEST...BUT THINK
NIL FORCING AND CONTINUED RISING HEIGHTS WILL MITIGATE A NEED FOR
A RAIN CHANCE AT THIS TIME. A WARM DAY...AND MOS SHOULD PERFORM
WELL IN THIS RATHER PREDICTABLE REGIME...SO AGAIN BLENDED PREVIOUS
FORECAST WITH MOST RECENT VALUES. SPOT CHECK OF LOW LEVEL
THICKNESS CONSIDERATIONS AND MIXING TO 850-825MB /DESPITE VERY
WEAK FLOW/ SUGGESTS WIDESPREAD LOWER TO MIDDLE 80S...VERY MUCH IN
LINE WITH THE BLEND.
LIKELY A REPEAT SCENARIO SATURDAY NIGHT WITH VALLEY FOG...AND
LOWS IN THE 50S.
SUNDAY IS A CARBON-COPY OF SATURDAY. DISTINCT CIRCULATION CENTERS
ATTENDANT TO THE SOUTHEAST CONUS TROUGH RECOMBINE OVER THE OUTER
BANKS OF NC WHILE THE MID LEVEL ANTICYCLONE CONTINUES TO DEEPEN TO
585DM OVER INTERIOR NEW ENGLAND. THIS WILL REINFORCE A LOW LEVEL
EASTERLY TRAJECTORY...THUS DON/T EXPECT MUCH /IF ANY/ DEWPOINT
RISE ON SUNDAY...AND TEMPERATURES SHOULD HOLD VERY SIMILAR TO
SATURDAY/S READINGS. PROBABLY A THICKER CIRRUS SHIELD PER BUFR
SOUNDINGS...BUT THAT WOULD BE ABOUT THE EXTENT OF SENSIBLE
WEATHER.
SUNDAY NIGHT BEGINS TO SEE SOME CHANGE AS A TROUGH OF LOW PRESSURE
/DAMPENING OUT AND SLOWING AS IT ENCOUNTERS THE BLOCKY FLOW ALONG THE
EAST COAST/ APPROACHES THE GREAT LAKES. HAVE KEPT THE NIGHTTIME
DRY AT THIS POINT AS 18.12Z GUIDANCE WAFFLING ON WEAK/MID LEVEL-
BASED SHOWERS AND STORM PLACEMENT AS FORCING SLOWLY INCREASES
LATER IN THE NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
PERIOD OF DRY WEATHER MAY COME TO AN END MONDAY AS MOISTURE AND
INSTABILITY INCREASE AHEAD OF AN UPPER TROUGH. WITH THE ECMWF AND
GFS COMING INTO FAIR AGREEMENT...KEPT A CHANCE OF THUNDERSTORMS FOR
MONDAY...MAINLY IN WESTERN COUNTIES THAT WILL BE AFFECTED MORE BY
SURFACE CONVERGENCE AND COOLER AIR ALOFT.
STAYED CLOSE TO ECMWF SOLUTION FOR TUESDAY SINCE IT CONTINUES TO
SHOW A CLOSED UPPER LOW FORMING AS OPPOSED TO THE FASTER OPEN WAVE
DEPICTED ON THE GFS. AS THE UPPER LOW FORMS NEAR CVG...THERE WILL BE
A GOOD CHANCE FOR THUNDERSTORMS UNDER A COOL POOL ALOFT COUPLED WITH
DEEP MOISTURE ADVECTION FROM THE SOUTH.
THUNDERSTORMS CHANCES WILL DIMINISH ON WEDNESDAY AS THE CLOSED UPPER
LOW SLIPS EAST ALLOWING DRIER AND MORE STABLE AIR TO WORK IN. THE
DRY CONDITIONS ARE EXPECTED TO CONTINUE ON THURSDAY AND FRIDAY WHEN
RIDGING ALOFT IS FORECAST TO MOVE BACK IN.
HIGH TEMPERATURES WILL BE MAINLY IN THE 80S MONDAY ON THE EAST SIDE
OF THE UPPER TROUGH. COOLER READINGS IN THE 70S ARE FORECAST AS THE
CLOSED LOW MAKES ITS WAY ACROSS THE AREA WITH ASSOCIATED CLOUD COVER
AND COLD ADVECTION. LOOK FOR A REBOUND TO THE 80S BY FRIDAY AS
SUNSHINE AND WARM ADVECTION RETURN.
&&
.AVIATION /05Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS THE TAF SITES
THROUGH THE TAF PERIOD. VFR CONDITIONS WILL START OUT THE TAF
PERIOD HOWEVER SOME FOG WILL BE POSSIBLE AT KLUK...KCVG...AND KILN
OVERNIGHT. VFR CONDITIONS WILL RETURN TO THE TAF SITES DURING THE
DAY ON SATURDAY. CU WILL DEVELOP ACROSS THE AREA DURING MAINLY THE
AFTERNOON HOURS. WINDS WILL BE LESS THAN 10 KNOTS.
OUTLOOK...THUNDERSTORMS ARE POSSIBLE MONDAY AND TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU/HATZOS
SHORT TERM...BINAU
LONG TERM...CONIGLIO
AVIATION...NOVAK
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1125 PM CDT FRI MAY 18 2012
.AVIATION...
CONCERNS REMAIN TRAJECTORY OF MVFR STRATUS OVERNIGHT. HAVE
CONTINUED WITH THE RUC OPS/BAK40 SOUNDINGS AND NAM12 BOUNDARY
LAYER RH/BUFR SOUNDINGS WITH CIGS REMAINING JUST SOUTH THROUGH
WEST OF THE METROPLEX...THOUGH SCATTERED STRATO-CU MAY BE AROUND
RIGHT AFTER SUNRISE SATURDAY MORNING.
FOR WACO...MAINTAINED A TREND OF MVFR CIGS BETWEEN 11Z AND
15Z...THEN VFR AFTERWARD.
CONFIDENCE ON STRATUS TRAJECTORY IS NOT HIGH WITH LITTLE OR NO
DEVELOPMENT AS OF 05Z UPSTREAM ALONG THE TX COASTAL BEND/LOWER TX
COAST/OR NORTHERN MEXICO YET.
OTHERWISE...SSE WINDS AROUND 10 KTS...WILL BECOME SLY NEAR 15 KTS
BY LATE MORNING SATURDAY WITH GUSTS TO OR IN EXCESS OF 25 KTS
POSSIBLE WITH VFR CONDITIONS. LOOK FOR GUSTS TO SETTLE DOWN BY 00Z
SUNDAY AS BOUNDARY LAYER SEMI DECOUPLES.
05/
&&
.UPDATE...
GRIDS IN EXCELLENT SHAPE. NO UPDATE NEEDED.
25
&&
.PREV DISCUSSION... /ISSUED 326 PM CDT FRI MAY 18 2012/
LOW LEVEL WARM AIR ADVECTION WILL CONTINUE ACROSS THE REGION
TONIGHT THROUGH SUNDAY AS SURFACE LOW PRESSURE MOVES EASTWARD
FROM THE HIGH PLAINS. A RELATIVELY TIGHT PRESSURE GRADIENT WILL
RESULT IN BREEZY CONDITIONS THIS EVENING AND AGAIN ON SATURDAY.
AS THE SURFACE LOW MOVES EAST...SURFACE HIGH PRESSURE WILL BUILD
SOUTHWARD AND A COLD FRONT WILL APPROACH THE RED RIVER SUNDAY
MORNING. A FEW SHOWERS AND THUNDERSTORMS WILL ACCOMPANY THE COLD
FRONT...WITH THE BEST CHANCE OF STORMS NORTH OF THE RED RIVER.
THE FRONT SHOULD STALL DURING THE DAYTIME HOURS DUE TO VIGOROUS
MIXING ALONG THE LEADING EDGE...BUT WILL BEGIN TO MOVE SOUTH
AGAIN SUNDAY NIGHT/MONDAY. THE BEST PUSH BEHIND THE FRONT WILL BE
EAST OF THE REGION. THEREFORE...THE FRONT WILL MOST LIKELY STALL
ACROSS THE NORTHERN PORTIONS OF NORTH TEXAS MONDAY AFTERNOON. THE
ATMOSPHERE WILL BE UNSTABLE ENOUGH FOR SCATTERED SHOWERS AND
THUNDERSTORMS ALONG AND NORTH OF THE FRONT. SEVERE STORMS ARE
UNLIKELY DUE TO A WEAK SHEAR PROFILE. THE COLD FRONT WILL LIFT
QUICKLY NORTH OF THE REGION MONDAY NIGHT/TUESDAY AS THE UPPER
PATTERN BECOMES MORE ZONAL AND RESULTS IN A THE DEVELOPMENT OF A
LEE TROUGH. THIS PATTERN WILL KEEP NORTH TEXAS WARM AND HUMID
NEXT WEEK WITH HIGHS MAINLY IN THE UPPER 80S AND LOW 90S AND LOWS
GENERALLY IN THE 60S.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 65 87 65 86 65 / 0 5 5 10 10
WACO, TX 65 87 65 87 66 / 0 5 5 5 10
PARIS, TX 62 85 64 86 66 / 0 5 5 10 10
DENTON, TX 63 87 64 85 64 / 0 5 5 10 10
MCKINNEY, TX 61 87 64 86 65 / 0 5 5 10 10
DALLAS, TX 64 87 64 88 65 / 0 5 5 10 10
TERRELL, TX 63 88 63 86 64 / 0 5 5 10 10
CORSICANA, TX 64 88 65 87 67 / 0 5 5 5 10
TEMPLE, TX 64 86 64 86 65 / 0 5 5 5 10
MINERAL WELLS, TX 63 89 65 86 63 / 0 5 5 10 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1054 PM CDT SUN MAY 20 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...SHOULD HAVE JUST CANCELLED THE WATCH FOR DOOR WITH THE
LAST UPDATE...BUT WL GO AHEAD AND DO THAT NOW. WITH THE SVR THREAT
GONE...MAIN ISSUE IS R-/L- FALLING OUT OF LOW DECK ACRS THE NW
PART OF THE FCST AREA. THAT WL CONT FOR A TIME AS BEST UPR SUPPORT
SWINGS ACRS THAT RGN...BUT IT SHOULD END DURING THE LATE EVENING.
WHAT WL HOPEFULLY BE THE LAST UPDATE FOR A WHILE WL BE OUT
SHORTLY.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 557 PM CDT SUN MAY 20 2012...
UPDATE...STORMS OVER FAR NE WI STILL FLIRTING WITH SVR CRITERIA
AT TIMES. SITN OVER E-C WI STILL MARGINAL AT BEST. FRONTAL
BOUNDARY SHOWING UP AS FINE-LINE ON RADAR. THE SVR RISK IS OVER
FOR AREAS BEHIND THE FINE-LINE. STILL A LITTLE NERVOUS ABOUT AREAS
TO THE E...AND IT/S NOT OUT OF THE QUESTION YET THAT SOMETHING
COULD DEVELOP FARTHER E WHEN FINE-LINE STARTS TO INTERACT WITH THE LAKE
BREEZE. ADMITTEDLY...THE CHCS OF THIS KICKING OFF A SVR STORM ARE
RATHER LOW. BUT HARD TO CANCEL WATCH WITH THIS MESO-SCALE
BOUNDARY INTERACTING STILL LURKING OUT THERE. PLAN TO JUST KEEP
NIPPING AWAY AT THE WESTERN EDGE OF THE WATCH FOR NOW.
SKOWRONSKI
DISCUSSION ISSUED AT 456 PM CDT SUN MAY 20 2012...
UPDATE...SVR THREAT CONTINUES OVER NERN WI. STORMS OVER NE WI ARE
IN THE AREA OF STRONGEST MOISTURE CONVERGENCE...AND ARE LIKELY TO
POSE A RISK OF SVR UNTIL THEY EXIT THE AREA. LOCAL MESO PLOTS
SUGGEST SOME INHIBITION STILL EXISTS FM DOOR CO NWD...SO WL SEE
HOW STORMS BEHAVE AS THEY NEAR THE LAKE.
SITN OVER E-C WI LESS CLEAR CUT. STILL SOME INSTABILITY AND INCRG
MOISTURE CONVERGENCE. BUT NOT MUCH HAS HAPPENED IN THIS AREA YET.
QG FORCING SWINGING THROUGH THE AREA AND INCREASED LOW-LEVEL
CONVERGENCE SUPPORT HOLDING ONTO THE WATCH FOR A WHILE LONGER
DESPITE LIMITED DEVELOPMENT THUS FAR. SVR THREAT MAY NOT BE AS
GREAT AS IT APPEARED EARLIER...BUT NOT COMFORTABLE CANCELING THE
WATCH UNTIL FRONT GOES THROUGH AND WINDS SHIFT W.
SKOWRONSKI
DISCUSSION ISSUED AT 419 PM CDT SUN MAY 20 2012...
UPDATE...SVR THREAT ENDING BEHIND ONGOING STORMS. WL BE CLEARING
THE SWRN/FAR WRN PART OF THE FCST AREA.
ALSO ADDED SC.Y TO THE NEARSHORE WATERS. WINDS MAY NOT BE QUITE AS
GUSTY OVER THE LAKE RIGHT NOW DUE TO STABILITY CONCERNS AND SLY
FLOW UP THE LENGTH OF THE LAKE...BUT SHOULD BE QUITE STG ON THE
BAY. SHOULD SEE A BRIEF PERIOD OF G30-35 KTS WINDS RIGHT BEHIND
THE COLD FRONT...AND WLY FLOW THEN SHOULD DRIVE STRONGER GUSTS OUT
OVER THE NSH WATERS.
SKOWRONSKI
DISCUSSION ISSUED AT 238 PM CDT SUN MAY 20 2012...
SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
MOVING NORTHEAST OVER CENTRAL WISCONSIN EARLY THIS AFTERNOON...JUST
AHEAD OF A SHORTWAVE TROUGH OVER EASTERN MINNESOTA. LINES OF
CONVECTION DEVELOPED AHEAD OF THIS SHORTWAVE TROUGH OVER
NORTH-CENTRAL AND NORTHWEST WISCONSIN BY MIDDAY WHERE WIND DAMAGE
AND HALF INCH HAIL OCCURRED EARLIER. INTENSIFICATION OF THE STORMS
REMAINS POSSIBLE THROUGH THE AFTERNOON...AS THE STORMS ENCOUNTER THE
INSTABILITY AXIS FROM WAUSHARA TO LAND O LAKES WHERE ML CAPES RANGE
FROM 1000-1500 J/KG. CAPES MAY NOT GET AS HIGH AS PREVIOUSLY
THOUGHT...SINCE SOME DRIER AIR IS MIXING DOWN TO THE SURFACE. DEEP
LAYER SHEAR REMAINS ABOUT 30-35 KTS...THOUGH THE VAD IS PICKING UP
ON 40KTS AT 2KFT. DAMAGING WIND GUSTS AND LARGE HAIL WILL REMAIN
THE PRIMARY THREATS WITH THE STORMS UNTIL THE SURFACE LOW AND COLD
FRONT DEPART EARLY THIS EVENING.
TONIGHT...LOW PRESSURE WILL MOVE NORTHEAST TONIGHT FROM FAR
NORTHEAST WISCONSIN TO EASTERN LAKE SUPERIOR. THE FRONT WILL STILL
HAVE TO CLEAR DOOR COUNTY AND WILL LEAVE LIKELY POPS FOR THE FIRST
PART OF THE EVENING. BEHIND THE FRONT...THINK WILL SEE SCATTERED
SHOWERS AND ISOLD THUNDERSTORMS EARLY THIS EVENING...THEN LIGHT
SHOWERS THROUGH MIDNIGHT AS COLDER AIR ARRIVES BEHIND THE
FRONT...AND A WIDESPREAD LOW STRATUS DECK SPREADS ACROSS THE AREA.
NORTHERN WISCONSIN MAY SEE THE LIGHT SHOWER ACTIVITY CONTINUE INTO
THE EARLY OVERNIGHT HOURS AS SOUNDINGS STILL LOOK SATURATED UP TO
ABOUT 700MB AT 06Z...BUT WILL GO DRY TO LINE UP WITH SURROUNDING
OFFICES. AT LEAST PARTIAL CLEARING WILL ARRIVE INTO NORTH-CENTRAL
WISCONSIN LATE TONIGHT WHEN DRIER AIR MOVES INTO THAT REGION. LOW
TEMPS RANGING FROM THE LOW 40S NORTH TO LOW 50S SE.
MONDAY...LOW STRATUS WILL PROBABLY HANG ON OVER EASTERN WISCONSIN TO
START THE DAY BUT SHOULD QUICKLY MOVE TO THE EAST DUE TO THE ARRIVAL
OF A MUCH DRIER AIRMASS AND REBOUNDING LOW LEVEL TEMPS. AS SKIES
TURN MOSTLY CLEAR TO PARTLY CLOUDY EVERYWHERE BY LATE IN THE
MORNING...HIGHS WILL REACH FROM THE MIDDLE 60S NORTH TO LOW 70S
SOUTH.
LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. A COOL SURFACE HIGH
PRESSURE SYSTEM WITH UPPER RIDGE WILL SETTLE INTO THE AREA FOR THE
FIRST HALF OF THE WORK WEEK WITH QUIET WEATHER AND COMFORTABLE
TEMPERATURES. THE PREVIOUS FORECAST RUN LOWERED TEMPS FOR MONDAY
NIGHT TO WARRANT NON HEADLINE FROST WORDING FOR NORTHERN
WISCONSIN. LATEST RUNS INDICATE LIGHT RETURN FLOW PCPN ALREADY
NEAR THE MN/WI BORDER AT 12Z TUESDAY. CLOUDS MAY ADVANCE INTO
NROTHERN WISCONSIN OVERNIGHT IN THE WESTERLY FLOW TO LIMIT TEMPS
FALLING. THIS TREND SUGGESTS LESS OF A TREND TOWARD ANY FROST
ADVISORY AT THIS TIME SO WILL CONTINUE WITH THE GOING FORECAST.
MAIN FORECAST CHALLENGE ARRIVES LATER IN THE NEW WORK WEEK AS A
BROAD UPPER TROUGH WORKS INTO THE WESTERN STATES AND NORTHERN
PLAINS. MEDIUM RANGE MODELS RUNS IN BETTER AGREEMENT WITH
CONFINING BEST POTENTIAL OF CONVECTION WITH THE RETURN FLOW OVER
THE NORTHERN PLAINS WITH PERHAPS BRUSHING NORTHWEST THIRD OF THE
STATE WEDNESDAY THROUGH WEDNESDAY NIGHT. SHORT WAVE TROUGH WITH
FRONTAL SYSTEM IS PROGGED TO SLIDE OVER STATE SOMETIME FROM
THURSDAY INTO THURSDAY NIGHT TO WARRANT THE HIGHEST PCPN CHC
DURING THIS PERIOD.
FRIDAY INTO SUNDAY...THE REGION WILL BE ON THE NORTHERN PERIPHERY
OF BROAD UPPER RIDGE OVER THE SOUTHERN PLAINS INTO THE SOUTHEAST
STATES. HOWEVER MODELS DIVERT ON CRITICAL LOCATION OF SURFACE
BOUNDARY SEPARATING DEEPER MOISTURE TO THE SOUTH FROM CONTINUED
DRIER CANADA AIR. 00Z ECMWF MAINLY POSITIONS THIS BOUNDARY ALONG
THE WISCONSIN ILLINOIS BORDER WHILE THE GFS IS FURTHER SOUTH. THE
12Z GFS KEEPS THE PCPN SOUTH...WHILE DEVELOPING CONVECTION THIS
SUNDAY AFTERNOON WILL LIKELY PREVENT A CHANCE TO LOOK AT THE
LATEST ECMWF RUN.
&&
.AVIATION...FOR 06Z TAF ISSUANCE. LOW CLDS HAVE SPREAD ACRS MOST
OF THE AREA. CIGS MAINLY IN MVFR CATEGORY...AND THE SOMEWHAT LOWER
CIGS THAT WERE ACRS THE NW PART OF THE AREA HAVE MIXED OUT.
ANTICIPATE MAINLY MVFR CIGS UNTIL THE BACK EDGE OF THE CLDS...NOW
ENTERING THE FCST AREA...WORKS E LATER TNGT. CAA SHOULD RESULT IN
ENOUGH MIXING TO KEEP LLWS FROM BEING NEEDED IN THE TAFS TNGT...SO
WL REMOVE WITH THE NEW ISSUANCE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1053 PM CDT SUN MAY 20 2012
.UPDATE...COOLEST AIRMASS BEHIND THE EXITING FRONT WILL SLIDE
THROUGH SOUTHERN WISCONSIN TONIGHT...WITH 925 MB TEMPS DROPPING TO
AROUND 6-8C. SHOULD SEE STRATUS UNDER THIS COOLER AIRMASS THROUGH
MUCH OF THE NIGHT...WITH SOME CLEARING WEST OF MADISON TOWARD
MORNING. BUMPED UP SKY COVER FOR OVERNIGHT INTO MONDAY MORNING
GIVEN LATEST MODELS AND SATELLITE. OTHERWISE...FORECAST LOOKS ON
TRACK WITH TEMPS FALLING ALL THE WAY INTO THE UPPER 40S AND LOW
50S.
&&
.AVIATION/06Z TAFS/...CLOUDY SKIES EXPECTED FOR MUCH OF THE NIGHT
UNDER A MUCH COOLER AIRMASS. ALREADY SEEING MVFR CIGS IN THE NORTH
AND WEST FORECAST AREA...AND EXPECT MOST AREAS WILL BE MVFR BY
06Z. STILL THINK CIGS COULD DROP AS LOW AS 1500 FT...CURRENTLY
SUPPORTED BY A FEW UPSTREAM OBS. SHOULD SEE SOME CLEARING WEST OF
MADISON TOWARD MORNING...WITH THE LOW CLOUDS EXITING THE SOUTHEAST
BY MID TO LATE MONDAY MORNING. SHOULD SEE SOME AFTERNOON CUMULUS
THEN DEVELOP...THOUGH CLOUD BASES WILL BE VFR.
&&
.PREV DISCUSSION... /ISSUED 358 PM CDT SUN MAY 20 2012/
..THIS AFTERNOON INTO EARLY EVENING...FORECAST CONFIDENCE MEDIUM.
SURFACE CONVERGENCE RIGHT ALONG THE PRE-FRONTAL TROUGH LOCATED NEAR
MADISON AND JANESVILLE AT 230 PM...IDENTIFIED BY A WIND SHIFT IN THE
SURFACE OBS...WILL BE THE FOCUS FOR SOME INITIAL CONVECTION PRIOR TO
THE MAIN FRONTAL BOUNDARY LOCATED IN THE FAR WESTERN FORECAST AREA
/CWA/...WHERE THERE IS ANOTHER WIND SHIFT. A FEW QUICK-MOVING POP-UP
SHOWERS WITH ISOLATED THUNDER ARE DEVELOPING JUST AHEAD OF THE
PRE-FRONTAL TROUGH EARLY THIS AFTERNOON AS WELL. THESE ARE A RESULT
AS GENERAL INSTABILITY WITH MIXED LAYER CAPE AROUND 1000 J/KG.
STEEP LOW LEVEL LAPSE RATES WITH A WELL-MIXED LAYER UP TO 7000 FEET
ARE ALLOWING FOR WINDS GUSTING UP TO 30 KNOTS. EXPECT HIGHER GUSTS
BENEATH SHOWERS WITH VIRGA.
EXPECT MORE THUNDERSTORM DEVELOPMENT OVER THE NEXT TWO HOURS IN THE
CENTRAL CWA...ESPECIALLY BETWEEN THE PRE-FRONTAL TROUGH AND MAIN
TROUGH WHERE THERE IS A PLUME OF HIGHER CAPE VALUES PER LATEST SPC
MESOSCALE ANALYSIS. POTENTIAL FOR SEVERE STORMS IS HIGHEST AS THIS
CORRIDOR SHIFTS INTO SOUTHEAST WI BETWEEN 21Z AND 00Z THIS
AFTERNOON. VERY ISOLATED ONE-INCH HAIL AND DAMAGING WIND GUSTS TO 60
MPH WOULD BE THE SEVERE THREAT. THERE IS NOT ENOUGH 6KM BULK SHEAR
OR LOW LEVEL SHEAR TO SUPPORT WELL-ORGANIZED SUPERCELLS OR
LONG-LIVED STORMS THAT WOULD PRODUCE WIDESPREAD SEVERE STORMS.
17Z HRRR CONTINUES TO SHOW A N-S ORIENTED UNORGANIZED LINE OF
THUNDERSTORMS THAT DEVELOP EAST OF MADISON AT 20Z AND TRACK DUE EAST
TO THE SHORELINE AT 23Z. MODELS AGREE ON ALL TSTORMS OUT OF CWA BY
00Z. LEFT SMALL CHANCE POPS IN THE FAR EAST THROUGH 03Z TO ACCOUNT
FOR POSSIBLE SLOWER MOVEMENT...THEN DRY WEATHER FOR THE REST OF THE
NIGHT.
TONIGHT AND MONDAY...FORECAST CONFIDENCE HIGH.
VISIBLE SATELLITE AND SURFACE OBSERVATIONS SHOW PLENTY OF CLOUDS
BEHIND THE COLD FRONT THIS AFTERNOON...BUT THESE MIGHT SCATTER OUT
THIS EVENING WITH THE LOSS OF DAYTIME HEATING AND THE STEEP LOW
LEVEL LAPSE RATES...IN COMBINATION WITH SUBSIDENCE BEHIND THE FRONT.
THIS MEANS THAT THERE IS AN OUTSIDE CHANCE THAT PEOPLE IN SOUTHERN
WI COULD VIEW THE PARTIAL SOLAR ECLIPSE EARLY THIS EVENING...
FILTERED THROUGH THE THINNER CLOUDS.
A SECONDARY 500MB TROUGH WILL TRACK ACROSS WI BETWEEN MIDNIGHT
TONIGHT AND NOON MONDAY. TOO DRY FOR PRECIP. A PERIOD OF LOW STRATUS
IS EXPECTED WITH THIS FEATURE IN COMBINATION WITH COLD AIR
ADVECTION...AND THEN SKIES SHOULD CLEAR FROM WEST TO EAST JUST AFTER
SUNRISE MONDAY MORNING. EXPECT DIURNAL CUMULUS CLOUDS TO DEVELOP IN
THE EARLY AFTERNOON.
WINDS WILL BE GUSTY OUT OF THE NORTH MONDAY MORNING WITH THE COLD
AIR ADVECTION AND STEEP LOW LEVEL LAPSE RATES. WINDS WILL TAPER OFF
IN THE AFTERNOON AS HIGH PRESSURE MOVES OVER WISCONSIN. A LAKE
BREEZE WILL DEVELOP WITH THE WEAKENING PRESSURE GRADIENT AND KEEP
AREAS NEAR THE LAKE IN THE LOWER 60S/POSSIBLY UPPER 50S. INLAND
TEMPS SHOULD MAKE IT UP TO AROUND 70.
MONDAY NIGHT THROUGH WEDNESDAY...FORECAST CONFIDENCE IS HIGH.
HIGH PRESSURE MOVES OVERHEAD MONDAY NIGHT...SLIPPING SOUTHEAST OF
WISCONSIN BY EARLY TUESDAY EVENING WITH RETURN FLOW BRINGING
WARMER TEMPS TO THE AREA ON WEDNESDAY. DRY THROUGH THIS PERIOD. A
LAKE BREEZE WILL BE FELT TUESDAY AND WEDNESDAY FOR COOLER READINGS
ALONG THE LAKE MICHIGAN SHORE. DWPNTS SHOULD MIX OUT DURING THE
DAY...SETTING UP SOME DECENT COOLING POTENTIAL BOTH MONDAY NIGHT
AND TUESDAY NIGHT.
THURSDAY THROUGH SATURDAY...FORECAST CONFIDENCE LOW TO MEDIUM.
THE ECMWF/GFS/CANADIAN NH ARE GETTING INTO BETTER AGREEMENT WITH
THE LATE WEEK/MEMORIAL DAY WEEKEND PERIOD...AND IT IS THE
ECMWF/CANADIAN THAT ARE COMING IN LINE WITH THE GFS. THERE ARE
TIMING DIFFERENCES...BUT THEY ALL EVENTUALLY BRING A FRONT THROUGH
THE AREA...PUTTING A DAMPER ON THE ONCE EXPECTED VERY WARM
WEEKEND...AT LEAST FOR THE START OF IT. WILL HAVE A SMALL CHANCE
OF SHOWERS AND STORMS REACHING THE FORECAST AREA ON THURSDAY...BASED
ON THE FASTER GFS/CANADIAN WITH THE APPROACHING TROF/FRONT. THE
ECMWF IS DRY FOR THURSDAY...THAT MAY WELL BE TRUE.
THE ASSOCIATED LOW PRESSURE SYSTEM WITH THIS SYSTEM WILL LIFT
NORTHEAST OF THE AREA...DRAGGING A COLD FRONT THROUGH SOUTHERN
WISCONSIN PROBABLY BY FRIDAY MORNING. THIS WILL PUSH THE WARM/HOT
TEMPS SOUTH OF THE BORDER...PUTTING US IN A COOLER NORTHERLY
FLOW. THE BOUNDARY REMAINS TO THE SOUTH OF WISCONSIN THROUGH
SATURDAY WITH A COOL EAST TO NORTHEAST SETTLING IN KEEPING THE
STATIONARY SFC FRONT SOUTH OF WISCONSIN FOR THE FIRST PART OF THE
WEEKEND. IN ADDITION...WITH THE BAROCLINIC ZONE IN THE VCNTY...WE
COULD SEE SOME SHOWERS AND STORMS FROM TIME TO TIME THROUGH FRIDAY
NIGHT.
THE FRONT COULD LIFT NORTH BY SUNDAY AS SOUTHERLY WINDS INCREASE
WITH LOW PRESSURE DEVELOPING WEST OF WISCONSIN. THIS WOULD BRING
THE WARM SECTOR BACK IN FOR WARMER AND DRY CONDITIONS FOR SUNDAY
AND MEMORIAL DAY.
AVIATION/00Z TAFS/...
CONVECTION AHEAD OF A COLD FRONT MOVING ACROSS WI THIS AFTERNOON.
BULK OF THUNDERSTORMS WILL BE EAST OF MADISON BETWEEN 21Z AND
23Z...EXITING FAR EASTERN WI BY 00Z. THERE IS UNCERTAINTY ABOUT
COVERAGE OF THESE THUNDERSTORMS...AS STRONGEST FORCING WILL BE NORTH
AND SOUTH OF THE TAF SITES. SHORT TERM MODELS SUGGEST AN UNORGANIZED
LINE OF MULTI-CELL THUNDERSTORMS ORIENTED NORTH-SOUTH TRACKING
STRAIGHT EAST.
WEAK SHEAR SHOULD INHIBIT STRONG AND LONG-LASTING THUNDERSTORM
DEVELOPMENT THIS AFTERNOON...HOWEVER SHORT BURSTS OF MARGINALLY
SEVERE HAIL AND DAMAGING WINDS ARE NOT OUT OF THE QUESTION WITH ANY
STRONGER STORMS.
WEST WINDS WILL DECREASE DURING THE EVENING AND BECOME NORTH BY
MONDAY MORNING. THE NORTH WINDS WILL BE GUSTY DURING THE MORNING
HOURS WITH COLD AIR ADVECTION BEHIND DEPARTING LOW PRESSURE SYSTEM.
THEN WINDS WILL DECREASE IN THE AFTERNOON AS HIGH PRESSURE SETTLES
INTO WI.
CLOUDS SHOULD SCATTER OUT FOR A PERIOD OF TIME BEHIND THE FRONT
EARLY THIS EVENING. THEN A PERIOD OF LOW STRATUS IN THE FUEL
ALTERNATE CATEGORY IS EXPECTED WITH THIS FEATURE IN COMBINATION WITH
COLD AIR ADVECTION...AND THEN SKIES SHOULD CLEAR FROM WEST TO EAST
JUST AFTER SUNRISE MONDAY MORNING. EXPECT VFR DIURNAL CUMULUS CLOUDS
TO DEVELOP IN THE EARLY AFTERNOON.
MARINE...
WINDS HAVE POTENTIAL TO FREQUENTLY GUST TO 25 KNOTS FOR A 4 TO 6
HOUR PERIOD OF TIME MONDAY MORNING IN THE WAKE OF THE DEPARTING LOW
PRESSURE SYSTEM. HIGHEST RISK OF SMALL CRAFT ADVISORY CONDITIONS
WILL BE FROM THE NORTH POINT LIGHT AND SOUTHWARD. TOO MARGINAL AT
THIS TIME TO ISSUE A HEADLINE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...DDV
TONIGHT/MONDAY AND AVIATION/MARINE...MRC
MONDAY NIGHT THROUGH SUNDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1049 PM CDT SUN MAY 20 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
321 PM CDT SUN MAY 20 2012
AFTER AN ACTIVE EARLY AFTERNOON...MAIN FORECAST CONCERNS SWITCH TO
TEMPERATURES THROUGH THE ENTIRE SHORT TERM PERIOD.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP OVER THE WESTERN U.S....A SHORTWAVE
TROUGH OVER MINNESOTA INTO WESTERN WISCONSIN...AND UPPER RIDGING
OVER THE EASTERN GREAT LAKES. DPVA AHEAD OF THE SHORTWAVE TROUGH...
COMBINED WITH INSTABILITY AND A SURFACE COLD FRONT TO ACT AS A
TRIGGER MECHANISM...HAS LED TO THE DEVELOPMENT OF A LINE OF SHOWERS
AND THUNDERSTORMS. THIS LINE AND COLD FRONT STRETCHES ALONG I-39 IN
WISCONSIN. MLCAPE VALUES OF 1000-1500 J/KG ARE PRESENT AHEAD OF THE
COLD FRONT. OTHER SHOWERS WERE PRESENT OVER NORTHWEST WISCONSIN...IN
AN AREA OF DEFORMATION ON THE NORTHWEST SIDE OF A SURFACE LOW IN
NORTHEAST WISCONSIN. MUCH OF THE FORECAST AREA NOW LIES IN COLD
ADVECTION BEHIND THE COLD FRONT...ALONG WITH A LOT OF STRATUS STUCK
IN THE FRONTAL INVERSION AS INDICATED ON THE 12Z MPX SOUNDING AT
915MB. A LITTLE LIGHT SHOWER/DRIZZLE ACTIVITY IS OCCURRING FROM
THESE CLOUDS TOO. TEMPERATURES HAVE FALLEN INTO THE UPPER 50S ACROSS
MUCH OF SOUTHEAST MINNESOTA...ABOUT 30 DEGREES COLDER THAN THIS TIME
YESTERDAY! CLOUDS CLEAR OUT BACK OVER WESTERN MINNESOTA AND THE
DAKOTAS WHERE DRIER AIR IS PRESENT...SEEN ON THE 12Z BIS AND ABR
SOUNDINGS. 850MB TEMPS DROP OFF QUITE A BIT TOO OVER THE
DAKOTAS...AROUND 6C AT BIS AND ABR COMPARED TO 16C AT GRB AND DVN
PER 12Z SOUNDINGS.
TONIGHT AND MONDAY...HIGH PRESSURE OVER THE DAKOTAS WILL SLIDE EAST
INTO THE FORECAST AREA ON MONDAY...IN THE WAKE OF THE CURRENT
SHORTWAVE TROUGH MOVING INTO MICHIGAN. SUBSIDENCE IN THE WAKE OF THE
TROUGH COMBINED WITH DRY AIR ADVECTION WILL ALLOW THE CLOUDS TO
GRADUALLY CLEAR OUT TONIGHT. MAY STILL BE DEALING WITH SOME
DEFORMATION LIGHT SHOWERS OVER TAYLOR AND CLARK COUNTIES THIS
EVENING...BUT EXPECT THESE TO END AS WELL WITH THE EASTWARD MOVEMENT
OF THE TROUGH. THIS LEAVES TEMPERATURES THE MAIN CONCERN. LOWS THIS
MORNING UNDER THE SURFACE HIGH WERE IN THE UPPER 30S. SINCE THE
HIGH REALLY DOES NOT BUILD INTO THE AREA TONIGHT...NOT
ANTICIPATING THE LOWS TO GET QUITE THAT COOL. HOWEVER...LOW TO
MIDDLE 40S DO SEEM LIKELY. PLENTY OF SUN ON MONDAY...COMBINED WITH
850MB TEMPS AROUND 6C AT MID DAY AND DRY AIR FOR GOOD MIXING
SUPPORT HIGHS REACHING THE LOWER 70S IN MOST LOCATIONS.
MONDAY NIGHT AND TUESDAY...UPPER RIDGING THAT HAS BEEN BUILDING OVER
THE WESTERN U.S. IS FORECAST TO BUILD INTO THE FORECAST AREA ON
TUESDAY...IN RESPONSE TO SOME FAIRLY DEEP TROUGHING DROPPING DOWN
INTO THE PACIFIC NORTHWEST. ALL MODELS AGREE THAT A DEEP LOW AROUND
OR JUST BELOW 990MB FORMS IN THE DAKOTAS DOWNSTREAM OF THIS
TROUGHING. STRENGTHENING WARM ADVECTION AHEAD OF THIS LOW AND
RIDGING BUILDING IN IS LIKELY TO RESULT IN AN EXPANSIVE AREA OF
ALTOSTRATUS AND CIRROSTRATUS. GOOD AGREEMENT EXISTS THAT THESE
CLOUDS WILL SPREAD INTO THE FORECAST AREA MONDAY NIGHT...THEN SLOWLY
SHIFT OFF TO THE EAST ON TUESDAY. RAISED CLOUD COVER CONSIDERABLY
GIVEN THE GOOD MODEL AGREEMENT ON THIS MOISTURE/CLOUDS. NO
ISENTROPIC LIFT IS NOTED WHERE THE CLOUD DECK EXISTS...THEREFORE
HAVE KEPT THE FORECAST DRY. TEMPERATURES ARE DEFINITELY
TRICKY...ESPECIALLY MONDAY NIGHT OVER WISCONSIN. WITH HIGH PRESSURE
AND DRY AIR IN PLACE OVER WISCONSIN MONDAY NIGHT...COULD SEE
TEMPERATURES DROP QUICKLY. THE CLOUDS THEN MOVE IN LATE IN THE
NIGHT. HAVE ONLY DROPPED LOWS TO NEAR 40 IN THE TYPICAL COLD SPOTS
OF WISCONSIN. SHOULD THE CLOUDS BE DELAYED...SOME FROST MENTION
WOULD BE NEEDED. TEMPERATURES MAY RISE LATE IN THE NIGHT OUT IN
SOUTHEAST MINNESOTA AS THE HIGH DEPARTS. STRENGTHENING SOUTHERLY
WINDS ON TUESDAY DUE TO A TIGHTENING PRESSURE GRADIENT...INCREASING
SUNSHINE ESPECIALLY WEST OF THE MISSISSIPPI RIVER...AND 850MB TEMPS
CLIMBING TO 10-14C BY 00Z SUPPORT HIGHS IN THE LOW 70S EAST TO NEAR
80 FAR WEST.
TUESDAY NIGHT AND WEDNESDAY...TROUGHING IS PROGGED TO CONTINUE TO
DEEPEN OVER THE WESTERN U.S. DURING THIS PERIOD...WHILE A MULTITUDE
OF SHORTWAVES EJECT OUT OF THIS TROUGH TOWARDS SOUTH CENTRAL CANADA.
THESE SHORTWAVES WILL HELP TO PUSH THE LOW INTO SOUTHEAST MANITOBA
BY 00Z THURSDAY...AND DRAG ITS COLD FRONT AT LEAST TO NEAR I-35...IF
NOT SLIGHTLY FARTHER EAST AS PROGGED BY THE 20.12Z NAM. A BIG HEAT
PLUME DEVELOPS UNDER THE LOW ON TUESDAY WHICH GETS SHUNTED EAST OVER
OUR AREA ON WEDNESDAY. 850MB TEMPS CLIMB TO AT LEAST 16-18C...IF NOT
HIGHER. IF PLENTY OF SUN OCCURS ON WEDNESDAY...GIVEN A TIGHT
PRESSURE GRADIENT IN PLACE TO MAINTAIN STRONG WINDS FOR MIXING...WE
COULD PUSH 90 AGAIN. HOWEVER...UPPER LEVEL RH PROGS SUGGEST WE MAY
BE DEALING WITH A LOT OF CIRRUS...TEMPERING THE HIGHS SOME.
CERTAINLY TUESDAY NIGHT WILL BE ABOVE NORMAL GIVEN THE BREEZY
SOUTHERLY FLOW FORECAST. LEANED TOWARD THE HIGH SIDE OF GUIDANCE FOR
LOWS. REGARDING PRECIPITATION CHANCES...WE WILL HAVE TO WAIT FOR THE
FRONT TO APPROACH GIVEN THE AREA BEING IN THE WARM SECTOR. SOME
CONCERN EXISTS THAT THE FRONT MAY NOT EVEN GET HERE AS REFERENCED
EARLIER...WITH EVEN THE 20.12Z ECMWF SLOWER STILL. THEREFORE...HAVE
KEPT PRECIPITATION CHANCES MAINLY TO THE AFTERNOON...DOWN NEAR 20
PERCENT...AND FOR WESTERN PORTIONS OF SOUTHEAST MINNESOTA ONLY.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
321 PM CDT SUN MAY 20 2012
THE LONG TERM FORECAST CONTINUES TO REMAIN PROBLEMATIC...WITH ISSUES
ON WHEN THE FRONT FROM WEDNESDAY MOVES INTO THE FORECAST AREA...THEN
POSSIBLE SUMMER HEAT FOR THE WEEKEND.
GOOD MODEL AGREEMENT EXISTS THAT ANOTHER SHORTWAVE EJECTING OUT OF
THE WESTERN TROUGH WILL DEVELOP A SURFACE LOW IN WESTERN KANSAS
WEDNESDAY EVENING. AS THIS SHORTWAVE LIFTS NORTHEAST...SO DOES THE
LOW...CAUSING THE WEDNESDAYS COLD FRONT EASTWARD PROGRESS TO STALL.
THE 20.12Z GEM IS BY FAR THE FASTEST BRINGING THIS SYSTEM
NORTHEAST...CROSSING THE AREA BY 18Z THURSDAY. MEANWHILE...THE GFS
JUST HAS IT GETTING INTO SOUTHEAST MINNESOTA AT 18Z THURSDAY AND THE
NEW 20.12Z ECMWF STILL HAS IT BACK IN NORTHWEST IOWA. THE VARIOUS
SPEEDS HAVE A GREAT IMPACT ON BOTH TEMPERATURES AND WHEN DPVA AND
POSSIBLY FRONTAL FORCED SHOWERS AND THUNDERSTORMS MOVE THROUGH. FOR
NOW...HAVE WENT TOWARDS A CONSENSUS SOLUTION WITH A SLIGHT LEAN
TOWARDS THE SLOWER GFS/ECMWF. THE ECMWF HAS BEEN VARYING BACK AND
FORTH TOO ON THE SPEED OF THIS SYSTEM.
NEXT PROBLEM FOR THURSDAY NIGHT AND RIGHT INTO THE WEEKEND IS THE
LOW PRESSURE SYSTEMS COLD FRONT AND HOW FAR SOUTH IT ENDS UP.
THIS ALL DEPENDS ON HOW FAST/MUCH RIDGING BUILDS OVER THE
MID-MISSISSIPPI VALLEY DOWNSTREAM OF A WELL AGREED UPON DEEP TROUGH
THAT FORMS NEAR CALIFORNIA. THE NEW 20.12Z ECMWF IS STRONGER THAN
ITS PREVIOUS RUN WITH THIS RIDGING...ALLOWING THE FRONT TO ONLY
STALL IN SOUTHERN IOWA BY FRIDAY EVENING. THE 20.12Z GEM IS SIMILAR.
ON THE OTHER HAND...THE GFS REMAINS FARTHER SOUTH DROPPING INTO
SOUTHERN MISSOURI. A CONSENSUS OF THE LAST 6 ECMWF RUNS AND TRENDS
IN THE CFSV2 MODEL SUGGEST A LEAN TOWARDS THE STRONGER RIDGING WOULD
BE PRUDENT. THEREFORE...THE FORECAST FROM THURSDAY NIGHT AND BEYOND
FOLLOWS AN OVERALL MODEL CONSENSUS WITH A LEAN TOWARDS THE 20.12Z
ECMWF. NO MATTER WHAT SOLUTION IS FOLLOWED...THE FRONT WILL MOVE
BACK NORTH AS A WARM FRONT AS THE WESTERN TROUGH SLOWLY PUSHES EAST.
MUCH OF THE EXTENDED HAS 20-40 PERCENT CHANCES FOR PRECIPITATION...
DUE TO TIMING ISSUES WITH THE WEDNESDAY NIGHT/THURSDAY/THURSDAY
NIGHT SYSTEM AND THEN THE FRONTAL BOUNDARY EVENTUALLY LIFTING BACK
NORTH FOR THE WEEKEND. IT DOES APPEAR THAT THE FRONTAL BOUNDARY MAY
GET CAPPED OFF TOWARDS SATURDAY NIGHT...ESPECIALLY SOUTH OF
I-90...SO A DRIER FORECAST IS IN PLACE THERE. TEMPERATURES SHOULD
STAY ABOVE NORMAL...AND POSSIBLY IF THE ECMWF IS RIGHT TO CLIMB INTO
THE 90S FOR SUNDAY. WILL NOT GO THAT HIGH BECAUSE OF THE VARYING
MODEL DIFFERENCES THAT EXIST.
&&
.AVIATION...THROUGH 06Z TUESDAY
1049 PM CDT SUN MAY 20 2012
HIGH PRESSURE WILL SETTLE ACROSS THE REGION THROUGH TODAY AND THEN
BEGIN TO SLIDE OFF TO THE EAST AFTER 00Z TUESDAY. VFR CONDITIONS
WITH CLEAR SKIES EXPECTED THROUGH THE TAF PERIOD. AS THE HIGH
SLIDES EAST...WINDS WILL BECOME MORE SOUTHERLY AFTER 00Z
TUESDAY...BUT REMAIN LIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
321 PM CDT SUN MAY 20 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
734 PM CDT SUN MAY 20 2012
.UPDATE...SHOULD HAVE JUST CANCELLED THE WATCH FOR DOOR WITH THE
LAST UPDATE...BUT WL GO AHEAD AND DO THAT NOW. WITH THE SVR THREAT
GONE...MAIN ISSUE IS R-/L- FALLING OUT OF LOW DECK ACRS THE NW
PART OF THE FCST AREA. THAT WL CONT FOR A TIME AS BEST UPR SUPPORT
SWINGS ACRS THAT RGN...BUT IT SHOULD END DURING THE LATE EVENING.
WHAT WL HOPEFULLY BE THE LAST UPDATE FOR A WHILE WL BE OUT
SHORTLY.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 557 PM CDT SUN MAY 20 2012...
UPDATE...STORMS OVER FAR NE WI STILL FLIRTING WITH SVR CRITERIA
AT TIMES. SITN OVER E-C WI STILL MARGINAL AT BEST. FRONTAL
BOUNDARY SHOWING UP AS FINE-LINE ON RADAR. THE SVR RISK IS OVER
FOR AREAS BEHIND THE FINE-LINE. STILL A LITTLE NERVOUS ABOUT AREAS
TO THE E...AND IT/S NOT OUT OF THE QUESTION YET THAT SOMETHING
COULD DEVELOP FARTHER E WHEN FINE-LINE STARTS TO INTERACT WITH THE LAKE
BREEZE. ADMITTEDLY...THE CHCS OF THIS KICKING OFF A SVR STORM ARE
RATHER LOW. BUT HARD TO CANCEL WATCH WITH THIS MESO-SCALE
BOUNDARY INTERACTING STILL LURKING OUT THERE. PLAN TO JUST KEEP
NIPPING AWAY AT THE WESTERN EDGE OF THE WATCH FOR NOW.
SKOWRONSKI
DISCUSSION ISSUED AT 456 PM CDT SUN MAY 20 2012...
UPDATE...SVR THREAT CONTINUES OVER NERN WI. STORMS OVER NE WI ARE
IN THE AREA OF STRONGEST MOISTURE CONVERGENCE...AND ARE LIKELY TO
POSE A RISK OF SVR UNTIL THEY EXIT THE AREA. LOCAL MESO PLOTS
SUGGEST SOME INHIBITION STILL EXISTS FM DOOR CO NWD...SO WL SEE
HOW STORMS BEHAVE AS THEY NEAR THE LAKE.
SITN OVER E-C WI LESS CLEAR CUT. STILL SOME INSTABILITY AND INCRG
MOISTURE CONVERGENCE. BUT NOT MUCH HAS HAPPENED IN THIS AREA YET.
QG FORCING SWINGING THROUGH THE AREA AND INCREASED LOW-LEVEL
CONVERGENCE SUPPORT HOLDING ONTO THE WATCH FOR A WHILE LONGER
DESPITE LIMITED DEVELOPMENT THUS FAR. SVR THREAT MAY NOT BE AS
GREAT AS IT APPEARED EARLIER...BUT NOT COMFORTABLE CANCELING THE
WATCH UNTIL FRONT GOES THROUGH AND WINDS SHIFT W.
SKOWRONSKI
DISCUSSION ISSUED AT 419 PM CDT SUN MAY 20 2012...
UPDATE...SVR THREAT ENDING BEHIND ONGOING STORMS. WL BE CLEARING
THE SWRN/FAR WRN PART OF THE FCST AREA.
ALSO ADDED SC.Y TO THE NEARSHORE WATERS. WINDS MAY NOT BE QUITE AS
GUSTY OVER THE LAKE RIGHT NOW DUE TO STABILITY CONCERNS AND SLY
FLOW UP THE LENGTH OF THE LAKE...BUT SHOULD BE QUITE STG ON THE
BAY. SHOULD SEE A BRIEF PERIOD OF G30-35 KTS WINDS RIGHT BEHIND
THE COLD FRONT...AND WLY FLOW THEN SHOULD DRIVE STRONGER GUSTS OUT
OVER THE NSH WATERS.
SKOWRONSKI
DISCUSSION ISSUED AT 238 PM CDT SUN MAY 20 2012...
SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
MOVING NORTHEAST OVER CENTRAL WISCONSIN EARLY THIS AFTERNOON...JUST
AHEAD OF A SHORTWAVE TROUGH OVER EASTERN MINNESOTA. LINES OF
CONVECTION DEVELOPED AHEAD OF THIS SHORTWAVE TROUGH OVER
NORTH-CENTRAL AND NORTHWEST WISCONSIN BY MIDDAY WHERE WIND DAMAGE
AND HALF INCH HAIL OCCURRED EARLIER. INTENSIFICATION OF THE STORMS
REMAINS POSSIBLE THROUGH THE AFTERNOON...AS THE STORMS ENCOUNTER THE
INSTABILITY AXIS FROM WAUSHARA TO LAND O LAKES WHERE ML CAPES RANGE
FROM 1000-1500 J/KG. CAPES MAY NOT GET AS HIGH AS PREVIOUSLY
THOUGHT...SINCE SOME DRIER AIR IS MIXING DOWN TO THE SURFACE. DEEP
LAYER SHEAR REMAINS ABOUT 30-35 KTS...THOUGH THE VAD IS PICKING UP
ON 40KTS AT 2KFT. DAMAGING WIND GUSTS AND LARGE HAIL WILL REMAIN
THE PRIMARY THREATS WITH THE STORMS UNTIL THE SURFACE LOW AND COLD
FRONT DEPART EARLY THIS EVENING.
TONIGHT...LOW PRESSURE WILL MOVE NORTHEAST TONIGHT FROM FAR
NORTHEAST WISCONSIN TO EASTERN LAKE SUPERIOR. THE FRONT WILL STILL
HAVE TO CLEAR DOOR COUNTY AND WILL LEAVE LIKELY POPS FOR THE FIRST
PART OF THE EVENING. BEHIND THE FRONT...THINK WILL SEE SCATTERED
SHOWERS AND ISOLD THUNDERSTORMS EARLY THIS EVENING...THEN LIGHT
SHOWERS THROUGH MIDNIGHT AS COLDER AIR ARRIVES BEHIND THE
FRONT...AND A WIDESPREAD LOW STRATUS DECK SPREADS ACROSS THE AREA.
NORTHERN WISCONSIN MAY SEE THE LIGHT SHOWER ACTIVITY CONTINUE INTO
THE EARLY OVERNIGHT HOURS AS SOUNDINGS STILL LOOK SATURATED UP TO
ABOUT 700MB AT 06Z...BUT WILL GO DRY TO LINE UP WITH SURROUNDING
OFFICES. AT LEAST PARTIAL CLEARING WILL ARRIVE INTO NORTH-CENTRAL
WISCONSIN LATE TONIGHT WHEN DRIER AIR MOVES INTO THAT REGION. LOW
TEMPS RANGING FROM THE LOW 40S NORTH TO LOW 50S SE.
MONDAY...LOW STRATUS WILL PROBABLY HANG ON OVER EASTERN WISCONSIN TO
START THE DAY BUT SHOULD QUICKLY MOVE TO THE EAST DUE TO THE ARRIVAL
OF A MUCH DRIER AIRMASS AND REBOUNDING LOW LEVEL TEMPS. AS SKIES
TURN MOSTLY CLEAR TO PARTLY CLOUDY EVERYWHERE BY LATE IN THE
MORNING...HIGHS WILL REACH FROM THE MIDDLE 60S NORTH TO LOW 70S
SOUTH.
LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. A COOL SURFACE HIGH
PRESSURE SYSTEM WITH UPPER RIDGE WILL SETTLE INTO THE AREA FOR THE
FIRST HALF OF THE WORK WEEK WITH QUIET WEATHER AND COMFORTABLE
TEMPERATURES. THE PREVIOUS FORECAST RUN LOWERED TEMPS FOR MONDAY
NIGHT TO WARRANT NON HEADLINE FROST WORDING FOR NORTHERN
WISCONSIN. LATEST RUNS INDICATE LIGHT RETURN FLOW PCPN ALREADY
NEAR THE MN/WI BORDER AT 12Z TUESDAY. CLOUDS MAY ADVANCE INTO
NROTHERN WISCONSIN OVERNIGHT IN THE WESTERLY FLOW TO LIMIT TEMPS
FALLING. THIS TREND SUGGESTS LESS OF A TREND TOWARD ANY FROST
ADVISORY AT THIS TIME SO WILL CONTINUE WITH THE GOING FORECAST.
MAIN FORECAST CHALLENGE ARRIVES LATER IN THE NEW WORK WEEK AS A
BROAD UPPER TROUGH WORKS INTO THE WESTERN STATES AND NORTHERN
PLAINS. MEDIUM RANGE MODELS RUNS IN BETTER AGREEMENT WITH
CONFINING BEST POTENTIAL OF CONVECTION WITH THE RETURN FLOW OVER
THE NORTHERN PLAINS WITH PERHAPS BRUSHING NORTHWEST THIRD OF THE
STATE WEDNESDAY THROUGH WEDNESDAY NIGHT. SHORT WAVE TROUGH WITH
FRONTAL SYSTEM IS PROGGED TO SLIDE OVER STATE SOMETIME FROM
THURSDAY INTO THURSDAY NIGHT TO WARRANT THE HIGHEST PCPN CHC
DURING THIS PERIOD.
FRIDAY INTO SUNDAY...THE REGION WILL BE ON THE NORTHERN PERIPHERY
OF BROAD UPPER RIDGE OVER THE SOUTHERN PLAINS INTO THE SOUTHEAST
STATES. HOWEVER MODELS DIVERT ON CRITICAL LOCATION OF SURFACE
BOUNDARY SEPARATING DEEPER MOISTURE TO THE SOUTH FROM CONTINUED
DRIER CANADA AIR. 00Z ECMWF MAINLY POSITIONS THIS BOUNDARY ALONG
THE WISCONSIN ILLINOIS BORDER WHILE THE GFS IS FURTHER SOUTH. THE
12Z GFS KEEPS THE PCPN SOUTH...WHILE DEVELOPING CONVECTION THIS
SUNDAY AFTERNOON WILL LIKELY PREVENT A CHANCE TO LOOK AT THE
LATEST ECMWF RUN.
&&
.AVIATION...FOR 00Z TAF ISSUANCE. LOW CLDS WL WORK SE ACRS THE
AREA THIS EVENING...QUESTION IS HOW FAR. WL CONT TO CARRY AT WRN
TAF SITES...BUT HOLD OUT OF THE E FOR NOW. WL TAKE ANOTHER LOOK AT
THAT LATER.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
633 PM CDT SUN MAY 20 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
321 PM CDT SUN MAY 20 2012
AFTER AN ACTIVE EARLY AFTERNOON...MAIN FORECAST CONCERNS SWITCH TO
TEMPERATURES THROUGH THE ENTIRE SHORT TERM PERIOD.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP OVER THE WESTERN U.S....A SHORTWAVE
TROUGH OVER MINNESOTA INTO WESTERN WISCONSIN...AND UPPER RIDGING
OVER THE EASTERN GREAT LAKES. DPVA AHEAD OF THE SHORTWAVE TROUGH...
COMBINED WITH INSTABILITY AND A SURFACE COLD FRONT TO ACT AS A
TRIGGER MECHANISM...HAS LED TO THE DEVELOPMENT OF A LINE OF SHOWERS
AND THUNDERSTORMS. THIS LINE AND COLD FRONT STRETCHES ALONG I-39 IN
WISCONSIN. MLCAPE VALUES OF 1000-1500 J/KG ARE PRESENT AHEAD OF THE
COLD FRONT. OTHER SHOWERS WERE PRESENT OVER NORTHWEST WISCONSIN...IN
AN AREA OF DEFORMATION ON THE NORTHWEST SIDE OF A SURFACE LOW IN
NORTHEAST WISCONSIN. MUCH OF THE FORECAST AREA NOW LIES IN COLD
ADVECTION BEHIND THE COLD FRONT...ALONG WITH A LOT OF STRATUS STUCK
IN THE FRONTAL INVERSION AS INDICATED ON THE 12Z MPX SOUNDING AT
915MB. A LITTLE LIGHT SHOWER/DRIZZLE ACTIVITY IS OCCURRING FROM
THESE CLOUDS TOO. TEMPERATURES HAVE FALLEN INTO THE UPPER 50S ACROSS
MUCH OF SOUTHEAST MINNESOTA...ABOUT 30 DEGREES COLDER THAN THIS TIME
YESTERDAY! CLOUDS CLEAR OUT BACK OVER WESTERN MINNESOTA AND THE
DAKOTAS WHERE DRIER AIR IS PRESENT...SEEN ON THE 12Z BIS AND ABR
SOUNDINGS. 850MB TEMPS DROP OFF QUITE A BIT TOO OVER THE
DAKOTAS...AROUND 6C AT BIS AND ABR COMPARED TO 16C AT GRB AND DVN
PER 12Z SOUNDINGS.
TONIGHT AND MONDAY...HIGH PRESSURE OVER THE DAKOTAS WILL SLIDE EAST
INTO THE FORECAST AREA ON MONDAY...IN THE WAKE OF THE CURRENT
SHORTWAVE TROUGH MOVING INTO MICHIGAN. SUBSIDENCE IN THE WAKE OF THE
TROUGH COMBINED WITH DRY AIR ADVECTION WILL ALLOW THE CLOUDS TO
GRADUALLY CLEAR OUT TONIGHT. MAY STILL BE DEALING WITH SOME
DEFORMATION LIGHT SHOWERS OVER TAYLOR AND CLARK COUNTIES THIS
EVENING...BUT EXPECT THESE TO END AS WELL WITH THE EASTWARD MOVEMENT
OF THE TROUGH. THIS LEAVES TEMPERATURES THE MAIN CONCERN. LOWS THIS
MORNING UNDER THE SURFACE HIGH WERE IN THE UPPER 30S. SINCE THE
HIGH REALLY DOES NOT BUILD INTO THE AREA TONIGHT...NOT
ANTICIPATING THE LOWS TO GET QUITE THAT COOL. HOWEVER...LOW TO
MIDDLE 40S DO SEEM LIKELY. PLENTY OF SUN ON MONDAY...COMBINED WITH
850MB TEMPS AROUND 6C AT MID DAY AND DRY AIR FOR GOOD MIXING
SUPPORT HIGHS REACHING THE LOWER 70S IN MOST LOCATIONS.
MONDAY NIGHT AND TUESDAY...UPPER RIDGING THAT HAS BEEN BUILDING OVER
THE WESTERN U.S. IS FORECAST TO BUILD INTO THE FORECAST AREA ON
TUESDAY...IN RESPONSE TO SOME FAIRLY DEEP TROUGHING DROPPING DOWN
INTO THE PACIFIC NORTHWEST. ALL MODELS AGREE THAT A DEEP LOW AROUND
OR JUST BELOW 990MB FORMS IN THE DAKOTAS DOWNSTREAM OF THIS
TROUGHING. STRENGTHENING WARM ADVECTION AHEAD OF THIS LOW AND
RIDGING BUILDING IN IS LIKELY TO RESULT IN AN EXPANSIVE AREA OF
ALTOSTRATUS AND CIRROSTRATUS. GOOD AGREEMENT EXISTS THAT THESE
CLOUDS WILL SPREAD INTO THE FORECAST AREA MONDAY NIGHT...THEN SLOWLY
SHIFT OFF TO THE EAST ON TUESDAY. RAISED CLOUD COVER CONSIDERABLY
GIVEN THE GOOD MODEL AGREEMENT ON THIS MOISTURE/CLOUDS. NO
ISENTROPIC LIFT IS NOTED WHERE THE CLOUD DECK EXISTS...THEREFORE
HAVE KEPT THE FORECAST DRY. TEMPERATURES ARE DEFINITELY
TRICKY...ESPECIALLY MONDAY NIGHT OVER WISCONSIN. WITH HIGH PRESSURE
AND DRY AIR IN PLACE OVER WISCONSIN MONDAY NIGHT...COULD SEE
TEMPERATURES DROP QUICKLY. THE CLOUDS THEN MOVE IN LATE IN THE
NIGHT. HAVE ONLY DROPPED LOWS TO NEAR 40 IN THE TYPICAL COLD SPOTS
OF WISCONSIN. SHOULD THE CLOUDS BE DELAYED...SOME FROST MENTION
WOULD BE NEEDED. TEMPERATURES MAY RISE LATE IN THE NIGHT OUT IN
SOUTHEAST MINNESOTA AS THE HIGH DEPARTS. STRENGTHENING SOUTHERLY
WINDS ON TUESDAY DUE TO A TIGHTENING PRESSURE GRADIENT...INCREASING
SUNSHINE ESPECIALLY WEST OF THE MISSISSIPPI RIVER...AND 850MB TEMPS
CLIMBING TO 10-14C BY 00Z SUPPORT HIGHS IN THE LOW 70S EAST TO NEAR
80 FAR WEST.
TUESDAY NIGHT AND WEDNESDAY...TROUGHING IS PROGGED TO CONTINUE TO
DEEPEN OVER THE WESTERN U.S. DURING THIS PERIOD...WHILE A MULTITUDE
OF SHORTWAVES EJECT OUT OF THIS TROUGH TOWARDS SOUTH CENTRAL CANADA.
THESE SHORTWAVES WILL HELP TO PUSH THE LOW INTO SOUTHEAST MANITOBA
BY 00Z THURSDAY...AND DRAG ITS COLD FRONT AT LEAST TO NEAR I-35...IF
NOT SLIGHTLY FARTHER EAST AS PROGGED BY THE 20.12Z NAM. A BIG HEAT
PLUME DEVELOPS UNDER THE LOW ON TUESDAY WHICH GETS SHUNTED EAST OVER
OUR AREA ON WEDNESDAY. 850MB TEMPS CLIMB TO AT LEAST 16-18C...IF NOT
HIGHER. IF PLENTY OF SUN OCCURS ON WEDNESDAY...GIVEN A TIGHT
PRESSURE GRADIENT IN PLACE TO MAINTAIN STRONG WINDS FOR MIXING...WE
COULD PUSH 90 AGAIN. HOWEVER...UPPER LEVEL RH PROGS SUGGEST WE MAY
BE DEALING WITH A LOT OF CIRRUS...TEMPERING THE HIGHS SOME.
CERTAINLY TUESDAY NIGHT WILL BE ABOVE NORMAL GIVEN THE BREEZY
SOUTHERLY FLOW FORECAST. LEANED TOWARD THE HIGH SIDE OF GUIDANCE FOR
LOWS. REGARDING PRECIPITATION CHANCES...WE WILL HAVE TO WAIT FOR THE
FRONT TO APPROACH GIVEN THE AREA BEING IN THE WARM SECTOR. SOME
CONCERN EXISTS THAT THE FRONT MAY NOT EVEN GET HERE AS REFERENCED
EARLIER...WITH EVEN THE 20.12Z ECMWF SLOWER STILL. THEREFORE...HAVE
KEPT PRECIPITATION CHANCES MAINLY TO THE AFTERNOON...DOWN NEAR 20
PERCENT...AND FOR WESTERN PORTIONS OF SOUTHEAST MINNESOTA ONLY.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
321 PM CDT SUN MAY 20 2012
THE LONG TERM FORECAST CONTINUES TO REMAIN PROBLEMATIC...WITH ISSUES
ON WHEN THE FRONT FROM WEDNESDAY MOVES INTO THE FORECAST AREA...THEN
POSSIBLE SUMMER HEAT FOR THE WEEKEND.
GOOD MODEL AGREEMENT EXISTS THAT ANOTHER SHORTWAVE EJECTING OUT OF
THE WESTERN TROUGH WILL DEVELOP A SURFACE LOW IN WESTERN KANSAS
WEDNESDAY EVENING. AS THIS SHORTWAVE LIFTS NORTHEAST...SO DOES THE
LOW...CAUSING THE WEDNESDAYS COLD FRONT EASTWARD PROGRESS TO STALL.
THE 20.12Z GEM IS BY FAR THE FASTEST BRINGING THIS SYSTEM
NORTHEAST...CROSSING THE AREA BY 18Z THURSDAY. MEANWHILE...THE GFS
JUST HAS IT GETTING INTO SOUTHEAST MINNESOTA AT 18Z THURSDAY AND THE
NEW 20.12Z ECMWF STILL HAS IT BACK IN NORTHWEST IOWA. THE VARIOUS
SPEEDS HAVE A GREAT IMPACT ON BOTH TEMPERATURES AND WHEN DPVA AND
POSSIBLY FRONTAL FORCED SHOWERS AND THUNDERSTORMS MOVE THROUGH. FOR
NOW...HAVE WENT TOWARDS A CONSENSUS SOLUTION WITH A SLIGHT LEAN
TOWARDS THE SLOWER GFS/ECMWF. THE ECMWF HAS BEEN VARYING BACK AND
FORTH TOO ON THE SPEED OF THIS SYSTEM.
NEXT PROBLEM FOR THURSDAY NIGHT AND RIGHT INTO THE WEEKEND IS THE
LOW PRESSURE SYSTEMS COLD FRONT AND HOW FAR SOUTH IT ENDS UP.
THIS ALL DEPENDS ON HOW FAST/MUCH RIDGING BUILDS OVER THE
MID-MISSISSIPPI VALLEY DOWNSTREAM OF A WELL AGREED UPON DEEP TROUGH
THAT FORMS NEAR CALIFORNIA. THE NEW 20.12Z ECMWF IS STRONGER THAN
ITS PREVIOUS RUN WITH THIS RIDGING...ALLOWING THE FRONT TO ONLY
STALL IN SOUTHERN IOWA BY FRIDAY EVENING. THE 20.12Z GEM IS SIMILAR.
ON THE OTHER HAND...THE GFS REMAINS FARTHER SOUTH DROPPING INTO
SOUTHERN MISSOURI. A CONSENSUS OF THE LAST 6 ECMWF RUNS AND TRENDS
IN THE CFSV2 MODEL SUGGEST A LEAN TOWARDS THE STRONGER RIDGING WOULD
BE PRUDENT. THEREFORE...THE FORECAST FROM THURSDAY NIGHT AND BEYOND
FOLLOWS AN OVERALL MODEL CONSENSUS WITH A LEAN TOWARDS THE 20.12Z
ECMWF. NO MATTER WHAT SOLUTION IS FOLLOWED...THE FRONT WILL MOVE
BACK NORTH AS A WARM FRONT AS THE WESTERN TROUGH SLOWLY PUSHES EAST.
MUCH OF THE EXTENDED HAS 20-40 PERCENT CHANCES FOR PRECIPITATION...
DUE TO TIMING ISSUES WITH THE WEDNESDAY NIGHT/THURSDAY/THURSDAY
NIGHT SYSTEM AND THEN THE FRONTAL BOUNDARY EVENTUALLY LIFTING BACK
NORTH FOR THE WEEKEND. IT DOES APPEAR THAT THE FRONTAL BOUNDARY MAY
GET CAPPED OFF TOWARDS SATURDAY NIGHT...ESPECIALLY SOUTH OF
I-90...SO A DRIER FORECAST IS IN PLACE THERE. TEMPERATURES SHOULD
STAY ABOVE NORMAL...AND POSSIBLY IF THE ECMWF IS RIGHT TO CLIMB INTO
THE 90S FOR SUNDAY. WILL NOT GO THAT HIGH BECAUSE OF THE VARYING
MODEL DIFFERENCES THAT EXIST.
&&
.AVIATION...TONIGHT AND MONDAY
633 PM CDT SUN MAY 20 2012
HIGH PRESSURE OVER THE HIGH PLAINS WILL BUILD INTO THE AREA
OVERNIGHT TONIGHT. AS A RESULT...SKIES WILL CLEAR OUT BETWEEN 00Z-
03Z THIS EVENING AT BOTH SITES...WITH VFR CONDITIONS IN ITS WAKE.
NORTHWEST WINDS WILL DECREASE THIS EVENING...TO UNDER 12 KNOTS BY
03Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
321 PM CDT SUN MAY 20 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...JLR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
345 PM CDT SAT MAY 19 2012
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
353 PM CDT SAT MAY 19 2012
AT 3 PM...A COLD FRONT EXTENDED FROM INTERNATIONAL FALLS MINNESOTA
TO SIOUX CITY IOWA. TEMPERATURES AHEAD OF THIS FRONT WERE IN THE
80S AND 90S. LA CROSSE WISCONSIN HAS REACHED 91 DEGREES. THIS WAS
THEIR FIRST 90-DEGREE TEMPERATURE OF 2012. BEHIND THIS FRONT...
TEMPERATURES WERE IN THE 50S AND 60S. WATER VAPOR AND PROFILERS
INDICATE A WEAK SHORT WAVE TROUGH MOVING THROUGH EASTERN MINNESOTA
AND WESTERN MINNESOTA. THIS SYSTEM IS PRODUCING SOME MID AND HIGH
CLOUDS. IN ADDITION...A FEW ISOLATED SHOWERS NEAR RED WING.
THE 19.18Z RAP AND 19.15Z HRRR CONTINUE TO SUGGEST THAT SCATTERED
SHOWERS AND THUNDERSTORMS WILL REMAIN MAINLY NORTHWEST OF A
PRESTON MINNESOTA TO NEILLSVILLE WISCONSIN LINE THIS EVENING.
WHILE THE 0-6KM SHEAR IS INCREASING TO GREATER THAN 40 KNOTS BY
20.06Z...THE ML SHEAR IS RAPIDLY DECREASING. AS A RESULT...THE
SEVERE WEATHER THREAT LOOKS VERY LOW. IF SOMETHING DID HAPPEN TO
OCCUR...DAMAGING WINDS WOULD BE THE MAIN THREAT. THIS IS MAINLY A
RESULT OF THE DRY AIR LOCATED BELOW THE CLOUD LAYER.
FROM LATE TONIGHT THROUGH EARLY SUNDAY AFTERNOON...THE COLD FRONT
WILL QUICKLY TRANSITION EASTWARD ACROSS THE FORECAST AREA. THIS IS
VERY SIMILAR TO SPEED THAT WAS SHOWN IN THE 18.12Z GFS. WITH THIS
TIMING...IT WILL BE MOVING THROUGH THE REGION DURING A TIME WHEN
THE ML CAPES WILL BE AT THEIR MINIMUM /GENERALLY LESS THAN 1000 J/KG/.
AS THE POSITIVELY TILTED TROUGH MOVES AWAY FROM THE AREA DURING
THE MORNING...THE BEST MOISTURE TRANSPORT AND 0-6 KM SHEAR WILL
MOVE NORTH AWAY FROM THE REGION. DUE TO THIS...THE AREAL COVERAGE
LOOKS TO BE SCATTERED AT BEST AND THE SEVERE WEATHER THREAT LOOKS
VERY SMALL. WITH A FASTER MOTION...THE AFTERNOON PRECIPITATION
CHANCES WERE LOWERED ACROSS THE AREA. IN ADDITION...A CLEARING
TREND IN THE CLOUDS WAS INTRODUCED. THIS LOOKS TO BE FAST ENOUGH
THAT MOST AREAS WILL GET AN OPPORTUNITY TO SEE THE ANNULAR ECLIPSE
ON SUNDAY EVENING. TEMPERATURES ACROSS NORTHEAST IOWA AND
SOUTHEAST MINNESOTA WILL LIKELY REMAIN STEADY THROUGHOUT THE DAY...
AND FALL DURING THE LATE MORNING AND AFTERNOON ACROSS WESTERN
WISCONSIN. THIS NON-DIURNAL TREND WAS INTRODUCED BY THE MIDNIGHT
CREW AND KEPT IN THE HOURLY TEMPERATURE GRIDS.
ON MONDAY...THE 850 MB TEMPERATURES LOOKS TO BE ABOUT 2C WARMER
THAN THE PREVIOUS MODELS. AS A RESULT...THE MAXIMUM TEMPERATURES
WERE RAISED ANYWHERE FROM 3 TO 5F.
.LONG TERM...TUESDAY THROUGH SATURDAY
353 PM CDT SAT MAY 19 2012
NEGATIVE OUTGOING LONG WAVE RADIATION ACROSS THE WESTERN
EQUATORIAL PACIFIC CONTINUES TO SHOW A RETROGRESSION TOWARD
INDONESIA. WITH SEA SURFACE TEMPERATURES IN THE EXCESS OF
26C...THIS AREA IS FAVORABLE TO SUPPORT STRONG TROPICAL FORCING.
NORMALLY WHEN THE CONVECTION IS ROBUST IN THIS AREA...A NEGATIVE
PACIFIC NORTH-AMERICAN TELECONNECTION DEVELOPS /WESTERN TROUGH AND
AN AMPLIFICATION OF AN EASTERN RIDGE/ ACROSS THE NORTH AMERICAN
CONTINENT. AT THE SAME TIME...ANOTHER AREA OF NEGATIVE OUTGOING
LONG WAVE RADIATION OVER THE EASTERN PACIFIC AND CENTRAL AMERICA
IS EXPECTED TO MOVE SLOWLY EAST ACROSS THE ATLANTIC. AS THIS
OCCURS...THE PERSISTENT TROUGH FROM THE MID-ATLANTIC SOUTH INTO
THE YUCATAN PENINSULA WILL MOVE EAST INTO THE CARIBBEAN.
OVERALL...THE 19.12Z MODELS SEEM TO HAVE A FAIRLY GOOD HANDLE ON
THIS SITUATION. THEY ARE IN GOOD AGREEMENT THAT A COLD FRONT WILL
MOVE SOUTHWARD INTO THE FORECAST AREA ON WEDNESDAY NIGHT...AND
THEN IT BECOMES STATIONARY FOR THURSDAY AND THURSDAY NIGHT. THIS
FRONT THEN MOVES NORTHWARD AS A WARM FRONT ON FRIDAY AS THE UPPER
LEVEL RIDGE BUILDS. THIS FRONT WILL BE THE FOCUS FOR SCATTERED
SHOWERS AND THUNDERSTORMS. IT WAS THE CONSENSUS THAT THE
OPERATIONAL GFS WAS TOO FAR SOUTH WITH THIS FRONT FROM FRIDAY INTO
SATURDAY NIGHT...THEREFORE...THE FORECAST WAS TRENDED MORE TOWARD
A BLEND OF THE ECMWF...GEM...AND A MAJORITY OF THE GFS SOLUTIONS.
BY DOING THIS...THE PRECIPITATION CHANCES WERE REMOVED SOUTH OF
THE INTERSTATE 90 CORRIDOR ON FRIDAY...AND ACROSS THE ENTIRE AREA
FROM FRIDAY NIGHT INTO SATURDAY NIGHT. IN ADDITION...THE
TEMPERATURES WERE RAISED FOR THIS TIME PERIOD. IF THE 19.12Z ECMWF
IS CORRECT ON SATURDAY...TEMPERATURES COULD BE WELL INTO THE MID
AND UPPER 90S.
&&
.AVIATION...THIS AFTERNOON THROUGH SUNDAY
1230 PM CDT SAT MAY 19 2012
THE GENERALLY DRY LOWER LEVELS AND BREEZY SOUTH FLOW WILL KEEP
CONDITIONS VFR AT BOTH KLSE AND KRST INTO THIS EVENING. WINDS WILL
AGAIN BE 10-20KTS G20-30KTS THIS AFTERNOON...STRONGEST AT THE HIGHER
TERRAIN/OPEN COUNTRY LOCATIONS...DIMINISHING QUICKLY THIS EVENING.
MOISTURE WILL CONTINUE TO INCREASE TONIGHT...AHEAD OF A COLD FRONT
DUE TO MOVE ACROSS THE AREA VERY LATE TONIGHT/MON MORNING. FRONT
LOOKS TO MOVE ACROSS KRST AROUND 12Z AND KLSE AROUND 15Z...WITH
WINDS SHIFTING TO THE NORTHWEST BEHIND IT. FRONT WILL ACT AS A FOCUS
FOR SHRA/TSRA DEVELOPMENT AS IT MOVES ACROSS THE AREA LATE TONIGHT/
SUN MORNING. FORCING IS ON THE WEAK SIDE AND WITH CONVECTION
EXPECTED TO BE SCT AS THE FRONT MOVES THRU...LEFT CIGS/VSBYS LATE
TONIGHT/SUN MORNING VFR. MAY YET NEED A TEMPO OR PREVAILING PERIOD
OF MVFR CIG/VSBY IN THE 09Z-15Z TIME-FRAME ONCE A MORE PRECISE
TIMING OF THE FRONT CAN BE DETERMINED...OR IF IT APPEARS A BKN LINE
OF CONVECTION WITH SOME STRONGER CELLS/TSRA WILL MOVE ACROSS THE TAF
SITES. GIVE LOWER PROBABILITY OF THIS AT THIS TIME...LEFT MVFR
MENTION CENTERED ON 12Z SUN OUT OF TAFS FOR NOW. DRIER NORTHWEST
FLOW/HIGH PRESSURE WILL BUILD ACROSS THE AREA BEHIND THE FRONT...
WITH GOOD VFR CONDITIONS EXPECTED BY LATE SUN MORNING/SUN AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
253 PM CDT SAT MAY 19 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
218 PM CDT SAT MAY 19 2012
.SHORT TERM...TONIGHT AND SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD FRONT
MOVING ACROSS THE NORTHERN MISSISSIPPI VALLEY AND HIGH PRESSURE
CENTERED OVER THE APPALACHIANS. THE FRONT HAS BEEN MOSTLY INACTIVE
SO FAR TODAY...THOUGH CONVECTION IS EXPECTED TO DEVELOP LATER THIS
AFTERNOON OVER MINNESOTA. EARLIER SHOWERS AND STORMS ALONG A
305-310K MOISTURE GRADIENT HAVE FIZZLED...AND THE LEFT OVER CIRRUS
SHIELD IS NOW ADVANCING INTO SW WISCONSIN. MOISTURE HAS BEEN
INCREASING TODAY ACROSS THE AREA AS EVIDENT BY RISING SURFACE
DEWPOINTS AND CU FORMATION. AS A SHORTWAVE OVER THE PLAINS PUSHES
THE FRONT TO THE EAST OVER THE NEXT 24 HOURS...PRECIP AND SEVERE
WEATHER CHANCES ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE COLD FRONT EXTENDING FROM THE NORTHERN MISSISSIPPI
VALLEY TO THE TEXAS PANHANDLE WILL SLOWLY MOVE EAST TONIGHT ACROSS
EASTERN MINNESOTA AND NW WISCONSIN. BEHIND THE FRONT...RIGHT REAR
QUAD OF THE JET...DPVA FROM THE SHORTWAVE...AND MID-LEVEL FGEN WILL
PROVIDE A CHANCE OF PRECIP. HAVE CONFINED POPS OVERNIGHT TO CENTRAL
AND NORTH-CENTRAL WISCONSIN IN CASE UPSTREAM PRECIP SNEAKS FARTHER
EAST.
NOT QUITE AS CONFIDENT ABOUT THIS EVENING HOWEVER. BAND OF PRECIP
THAT STRETCHED FROM SOUTHERN MINNESOTA TO MISSOURI DISSIPATED BY
MIDDAY...POSSIBLY AS A RESULT OF DIMINISHING MID-LEVEL CONVERGENCE.
MOISTURE ADVECTION ON THE 305-310K ISENTROPIC SURFACES...WHICH WAS
ALIGNED WITH THE BAND OF PRECIP...WILL MOVE ACROSS THE FORECAST AREA
THIS EVENING...UNDER MID-LEVEL LAPSE RATES OF 7.5-8 C/KM. PROGGED
SOUNDINGS INDICATE ELEVATED CAPES BETWEEN 500-1000 J/KG ARRIVE WITH
THE MOISTURE ADVECTION. DO NOT SEE THE MID-LEVEL CONVERGENCE
RETURNING...BUT DO NOT NECESSARILY TRUST GOING DRY EITHER. SINCE THE
CLOUD BAND HAS BEEN THINNING AND CLOUD TOPS WARMING...HAVE DECIDED
TO GO DRY THIS EVENING.
SUNDAY...THE SHORTWAVE TROUGH WILL MOVE ACROSS CENTRAL AND
NORTH-CENTRAL WISCONSIN DURING THE MORNING...AND NORTHEAST WISCONSIN
IN THE AFTERNOON. WITH FORCING BEHIND THE FRONT HOLDING
TOGETHER...SHOULD SEE SCT SHOWERS AND THUNDERSTORMS MOVE EAST ACROSS
THE FORECAST AREA THROUGH THE DAY. AN UPTICK OF SHOWERS AND STORMS
WILL BE POSSIBLE IN THE AFTERNOON OVER NORTHEAST WISCONSIN WHERE
THERE WILL BE HIGHER DAYTIME INSTABILITY. ASSUMING CLOUD COVER
ALLOWS SUFFICIENT SUNSHINE...BOTH THE NAM AND GFS INDICATE 1000-1500
J/KG OF ML CAPE DEVELOPING BY MIDDAY...USING A SURFACE PARCEL OF
80F/61F. HIGHER WINDS ALOFT WILL EXIST BEHIND THE FRONT...BUT 0-6KM
BULK SHEAR VALUES OF 25-30KT...WEAK CONVERGENCE ALONG THE
FRONT...AND A FAIRLY UNIDIRECTIONAL WIND PROFILE SUGGESTS AN
ISOLATED THREAT FOR SEVERE STORMS FOR WINDS AND HAIL AHEAD OF THE
FRONT OVER NE WISCONSIN IN THE AFTERNOON. WILL KEEP A MENTION IN
THE HWO. MORNING PRECIP WILL HOLD BACK TEMPS OVER CENTRAL AND
NORTH-CENTRAL WISCONSIN IN THE MID 70S...WHILE NORTHEAST WISCONSIN
COULD POSSIBLY REACH INTO THE LOWER TO MID 80S.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. TIMING OF PCPN
CHANCES WILL BE THE PRIMARY CHALLENGE.
MAIN CHANGE FOR SUNDAY EVENING IS THE FASTER FROPA AND BEST
INSTABILITY IS DIMINISHING QUICKLY. WILL HANG ONTO A LINGERING
CHANCE OF LIGHT CONVECTION FOR EASTERN WISCONSIN AS A MID LEVEL
TROUGH WILL TRAIL THE SURFACE COLD FRONT SLIGHTLY.
OTHERWISE HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN LATER
SUNDAY NIGHT INTO WEDNESDAY. UPPER RIDGE BUILDS INTO THE NORTHERN
PLAINS BY THE MIDDLE OF THE NEXT WEEK. MEDIUM RANGE RUNS DIVERT ON
LOCATION OF RETURN FLOW AHEAD OF A LOW PRESSURE SYSTEM OVER THE
NORTHERN PLAINS. THE GFS ATTEMPTS TO DEVELOP SMALL CHC POPS OVER
NORTH CENTRAL WISCONSIN CLOSER TO THE RETURN FLOW. MEDIUM RANGE
MODEL RUNS DIVERT AFTER THURSDAY AND THEREFORE RESOLUTION OF THE
FORECAST DIMINISHES. THE GFS BREAKS DOWN THE UPPER RIDGE FASTER
FOR LATER NEXT WEEK AND DRAGS THE FRONTAL SYSTEM OVER FASTER VS
THE SLOWER ECMWF. THE ECMWF ALSO BUILDS THE RIDGE AGAIN FOR A
WARMER NEXT WEEKEND. BLEND OF THE RUNS PRODUCING WIDESPREAD
SLIGHT CHANCES IN THE FORECAST DUE TO THIS TIMING ISSUE. THIS
TIMING OF THE BREAKDOWN OF THE WARM RIDGE ALSO IMPACT THE
TEMPERATURE MAX/MIN`S.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH AT LEAST
TONIGHT. THERE IS A VERY SMALL CHANCE OF A SHOWER THIS
EVENING...BUT SCT PRECIP OVER THE PLAINS IS DIMINISHING AS IT MOVES
NORTHEAST. SO NOT WORTH INCLUDING IN THE TAFS AT THIS TIME. GUSTY
SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH EARLY THIS EVENING
BEFORE DIMINISHING. LLWS TO DEVELOP OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN TONIGHT AS A COLD FRONT MOVES INTO THE STATE. THIS FRONT
WILL HAVE POTENTIAL TO CREATE SHOWERS AND THUNDERSTORMS THROUGH THE
DAY ON SUNDAY.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/TDH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
243 AM CDT SAT MAY 19 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
243 AM CDT SAT MAY 19 2012
THE MAIN FOCUS THROUGH THE WEEKEND AND EARLY NEXT WEEK IS WITH THE
SHOWER/THUNDERSTORM CHANCES TONIGHT INTO SUNDAY ALONG WITH
TEMPERATURES AND WINDS FOR TODAY.
AN ELONGATED TROUGH OF SURFACE LOW PRESSURE CONTINUES TO DRIFT
EAST ACROSS THE CENTRAL PLAINS WITH MUCH OF THE UPPER MISSISSIPPI
RIVER VALLEY IN THE WARM SECTOR OF THIS SYSTEM. THE MAIN LOW
IS GETTING ORGANIZED ACROSS EASTERN COLORADO/SOUTHWEST NEBRASKA
WHICH IS AHEAD OF A DIGGING MID LEVEL TROUGH STILL OUT IN THE
ROCKIES. IN THE NEAR TERM...JUST DEALING WITH SOME HIGH LEVEL
CLOUD COVER AND A DECOUPLED ATMOSPHERE. STORMS IN CENTRAL TO
NORTHERN MINNESOTA WILL CONTINUE TO LIFT TO THE NORTH AHEAD OF A
MID LEVEL SHORTWAVE TROF WHICH WILL TAKE A SIMILAR PATH. THE
SOUTHERN EXTENT OF THIS TROUGH WAS VISIBLE ACROSS IOWA VIA IR
SATELLITE EARLIER...BUT HAS SINCE DISSIPATED.
THREE MAIN FORECAST ISSUES FOR TODAY INCLUDE HOW WARM
TEMPERATURES WILL GET...HOW STRONG WILL THE WINDS BECOME...AND
WHEN WILL CONVECTION MOVE INTO THE REGION.
TEMPERATURE-WISE...THE 19.00Z NAM/GFS/ECMWF/GEM DO NOT SHOW MUCH
IN THE WAY OF THE AIR MASS MODERATING ACROSS THE REGION TODAY WITH
850MB TEMPERATURES LINGERING AROUND +16C. YESTERDAY...THESE 850MB
TEMPERATURES WERE A BIT HIGHER IN WESTERN MINNESOTA AND IOWA AT
ABOUT +20C TO +22C. WITH FULL MIXING IT BROUGHT SURFACE
TEMPERATURES INTO THE MID 90S WHILE DEW POINTS ACTUALLY HELD ON
INTO THE LOW 50S. WITH A SIMILAR DAY OF FULL MIXING LOCALLY...EXPECT
THAT TEMPERATURES SHOULD BE PRETTY CLOSE TO WHERE WE ENDED UP
TODAY WITH MOST LOCATIONS IN THE UPPER 80S AND SOME SPOTS GETTING
INTO THE 90S.
AS FOR THE WINDS...A TIGHT SURFACE PRESSURE GRADIENT WILL REMAIN
IN PLACE THROUGH THIS AFTERNOON DUE TO THE DEEPENING SURFACE LOW
IN THE SOUTHERN PLAINS AND RIDGE OFF TO THE EAST. 19.00Z NAM
BUFKIT SOUNDINGS FROM RST SHOW MIXING FROM THE SURFACE ON UP TO
AROUND 800MB WITH WINDS OF ABOUT 40KTS AT THE BASE OF THE
INVERSION AROUND 800MB. MOMENTUM TRANSFER SHOWS THAT THE GUSTS
SHOULD BE AROUND 30-35KTS WITH LESSER AMOUNTS AS YOU MOVE INTO THE
LOWER TERRAIN TO THE EAST. CONSIDERED A WIND ADVISORY FOR
PORTIONS OF SOUTHEAST MINNESOTA AND NORTHEAST IOWA FOR TODAY...BUT
CONFIDENCE WAS NOT HIGH ENOUGH TO DO SO GIVEN THAT THE ADVISORY
CRITERIA GUSTS WOULD BE FAIRLY LOCALIZED AND NOT WIDESPREAD/LONG
LASTING.
PRECIPITATION CHANCES WILL BE ON THE INCREASE AS THE TROUGH/COLD
FRONT INCH EASTWARD THIS EVENING AND OVERNIGHT ACROSS EASTERN
MINNESOTA...CENTRAL IOWA AND NORTHWEST WISCONSIN. MUCH OF THE
FOCUS FOR LIFT WILL COME AS A MID LEVEL TROUGH TRACKS NORTHEAST
THROUGH THE SOUTHWESTERLY FLOW. THE 19.00Z NAM/GFS/GEM SHOW THIS
MAIN MID LEVEL TROUGH LIFTING NORTHEAST ALONG THE BOUNDARY EARLY
SUNDAY MORNING WITH THE SURFACE COLD FRONT MOVING THROUGH IN THE
AFTERNOON. THERE IS SOME CONCERN FOR SEVERE WEATHER ON SUNDAY DUE
TO A MID LEVEL JET STREAK MOVING THROUGH WITH THE TROUGH AND
BUILDING INSTABILITY AHEAD OF THE SURFACE COLD FRONT/LOW. THE
TIMING OF THE FRONT AND/OR PRE-FRONTAL SURFACE TROUGH IS IDEAL FOR
MAXIMIZING PEAK HEATING...BUT IT APPEARS THAT THE BETTER DEEP WIND
SHEAR COMES THROUGH IN THE MORNING AS THE TROUGH MOVES THROUGH
WITH THE 40-50KT JET STREAK NORTH OF LAKE SUPERIOR BY AFTERNOON.
IF THE SOUTHERN PORTION OF THE MID LEVEL JET STREAK CAN LINGER
INTO THE AFTERNOON...IT MAY PROVIDE SOME BETTER 0-6KM SHEAR TO
WORK WITH SOME SURFACE BASED INSTABILITY OF 1000-2000J/KG TO
PRODUCE SOME ORGANIZED CONVECTION. THESE STORMS/SHOWERS SHOULD
EXIT THE REGION SUNDAY NIGHT WITH HIGH PRESSURE AND COOLER AIR
DROPPING DOWN BEHIND THE SYSTEM.
.LONG TERM...TUESDAY THROUGH FRIDAY
243 AM CDT SAT MAY 19 2012
QUIET START TO THE EXTENDED PERIOD AS A RIDGE OF HIGH PRESSURE
MOVES ACROSS THE REGION OVER THE MIDDLE OF THE WEEK. THE NEXT
FEATURE TO POSSIBLY BRING SOME PRECIPITATION TO THE REGION COMES
IN ON WEDNESDAY AFTERNOON IS A COLD FRONT THAT WILL DROP INTO
MINNESOTA. SOME FAIRLY SIGNIFICANT DIFFERENCES CROP UP BETWEEN THE
19.00Z GFS/ECMWF/GEM WITH THIS FRONT AND HOW MUCH PROGRESS IT
MAKES TO THE EAST GOING INTO THE LATER PORTION OF THE WEEK. THE
GFS HAS BEEN PRETTY CONSISTENT WITH SWINGING THE COLD FRONT
THROUGH THE REGION AND THEN SETTING IT UP TO THE SOUTH WITH COOL
AIR MOVING IN BEHIND IT. MEANWHILE...THE ECMWF HAS BEEN BOUNCING
BACK AND FORTH WITH WHETHER THE FRONT EVEN MAKES IT INTO THE
REGION ON THURSDAY. OVER THE PAST TWO DAYS...THE 12Z RUNS HAVE
BEEN TAKING THE FRONT FURTHER EAST AND BRINGING PRECIPITATION IN
WHILE THE 00Z RUNS HAVE KEPT US MAINLY DRY. THE GEM DOES SOMETHING
SIMILAR TO THE 00Z ECMWF RUNS WITH KEEPING THE FRONT OFF TO THE
WEST AS WELL. WHILE THE 19.00Z GFS APPEARS TO BE AN OUTLIER AT
THIS POINT...CAN NOT RULE OUT THE POSSIBILITY OF CONVECTION
GETTING INTO THE REGION AND HAVE LEFT SOME CHANCES OUT IN THE
EXTENDED PERIOD THOUGH CONFIDENCE IS NOT VERY HIGH WITH THEM.
THE MOST NOTEWORTHY FEATURE IN THE EXTENDED PERIOD IS WITH THE
HEAT WAVE THAT THE 19.00Z ECMWF IS FORECASTING FROM THURSDAY
ONWARD INTO MEMORIAL DAY WEEKEND AS THE FRONT STALLS AND IS FORCED
UP TO THE NORTH AS SOUTHERLY LOW LEVEL FLOW BRINGS WARM AIR BACK
INTO THE REGION. THE 19.00Z ECMWF IS FORECASTING HIGH TEMPERATURES
OF 85-95F FROM THURSDAY THROUGH MONDAY WHILE THE 19.00Z GFS
REMAINS MUCH COOLER. AS PREVIOUSLY MENTIONED...CONFIDENCE IS NOT
HIGH WITH WHAT MODEL IS THE TREND SETTER...BUT IF THE ECMWF IS THE
TREND THEN WE ARE WAY UNDER DOING TEMPERATURES GOING INTO NEXT
WEEKEND.
&&
.AVIATION...THROUGH 06Z SUNDAY
1145 PM CDT FRI MAY 18 2012
SOUTHERLY FLOW WILL CONTINUE AT THE TAF SITES THROUGH THE PERIOD.
VFR CONDITIONS ARE EXPECTED THOUGH 06Z SATURDAY. WINDS HAVE
DECOUPLED AT KLSE WITH SURFACE WINDS AROUND 10 KNOTS. KARX VAD
WIND PROFILER SHOWS 2000 FOOT WINDS AT 40 KNOTS AND BOTH THE
19.02Z RAP AND 19.00Z NAM BUFKIT SOUNDINGS SHOWING 35 TO 40 KNOT
WINDS CONTINUING JUST OFF THE SURFACE. THUS DID INCLUDE LLWS AT
THE KLSE SITE THROUGH 14Z. LOW LEVEL WINDS AT KRST WILL BE MARGINAL
FOR LLWS AND WILL NOT INCLUDE. WINDS WILL PICK UP ONCE AGAIN
SATURDAY WITH SOME GUSTS TO 30 KNOTS AT KRST AND NEAR 25 KNOTS AT
KLSE. A COLD FRONT WILL THEN MOVE INTO WESTERN MINNESOTA DURING
THE AFTERNOON AND EVENING HOURS. DID MENTION VCSH AT KRST AFTER
01Z AS FRONT APPROACHES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
243 AM CDT SAT MAY 19 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1146 PM CDT FRI MAY 18 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
343 PM CDT FRI MAY 18 2012
AT 3 PM...A TIGHT SURFACE PRESSURE GRADIENT HAS DEVELOPED BETWEEN
A HIGH PRESSURE SYSTEM OVER NEW ENGLAND AND A LOW PRESSURE SYSTEM
OVER SOUTH DAKOTA. THIS GRADIENT WAS PRODUCING SUSTAINED WINDS IN
THE 15 TO 25 MPH RANGE AND WIND GUSTS AROUND 35 MPH. THE HIGHEST
WIND GUSTS WERE 37 MPH AT THE ROCHESTER ASOS AND NEAR DEXTER
MINNESOTA. THE COMBINATION OF SOUTHERLY WINDS AND ABUNDANT SUNSHINE
HAS ALLOWED TEMPERATURES TO CLIMB TO AROUND 90 ACROSS NORTHEAST
IOWA AND SOUTHEAST MINNESOTA...AND FROM THE MID TO LOWER 90S ACROSS
WESTERN WISCONSIN. THIS MAKES IT THE WARMEST DAY OF THIS YEAR IN
MOST LOCATIONS. SO FAR THIS AFTERNOON...THE WARMEST TEMPERATURE
REPORTED WAS 94 DEGREES FROM EYOTA /MINNESOTA DOT/.
FOR TONIGHT...THE 18.12Z MODELS ARE IN VERY GOOD AGREEMENT THAT
A POSITIVELY TILTED SHORT WAVE TROUGH WILL MOVE NORTHEAST THROUGH
THE REGION. BUFKIT SOUNDINGS SHOW THAT THE AIR MASS BELOW 600 MB
WILL REMAIN RATHER DRY. AS A RESULT...ONLY EXPECTING A SCATTERED
TO OCCASIONALLY BROKEN DECK OF MID AND HIGH CLOUDS TO MOVE THROUGH
THE REGION. THE GREATEST PERCENTAGE OF THESE CLOUDS WILL WEST OF
THE MISSISSIPPI RIVER.
ON SATURDAY...THE MAXIMUM TEMPERATURE FORECAST IS RATHER TRICKY.
THIS IS DUE TO THE UNCERTAINTY ON HOW WARM THE TEMPERATURES WILL
BE ALOFT /NAM HAS THE SAME TEMPERATURES AS TODAY AND THE GFS IS 2C
COOLER/ AND MORE AFTERNOON CLOUDS ACROSS THE REGION. DUE TO THE
LATTER...TRENDED THE FORECAST A COUPLE OF DEGREES COOLER.
THE GFS DOES GENERATE PRECIPITATION NORTH OF THE INTERSTATE 94
CORRIDOR ON SATURDAY AFTERNOON. THIS IS DUE TO A STRONG PV ANOMALY
MOVING NORTHEAST THROUGH THE REGION. MEANWHILE THE NAM/ECMWF/GEM
HAVE A MUCH WEAKER PV ANOMALY. SINCE THE GFS IS TYPICALLY TO
ROBUST WITH THESE ANOMALIES...SO OPTED TO KEEP THE FORECAST DRY.
ANOTHER FORECAST ISSUE ON SATURDAY AFTERNOON WILL BE THE DEW
POINTS. ALL OF THE MODELS ARE SHOWING THAT THE DEW POINTS WILL
CLIMB INTO THE LOWER 60S. THIS LOOKS TO BE TOO HIGH WHEN ONE
TAKES IN ACCOUNT THE DRY AIR ALOFT. THE DEW POINT MIX DOWN TOOL
SUGGESTS THAT THE DEW POINTS WILL BE MORE IN THE LOWER AND MID
50S. THIS SEEMS MUCH MORE REALISTIC...THUS...WENT AT LEAST 5 TO 8F
LOWER THAN THE MOS VALUES.
FROM SATURDAY NIGHT INTO SUNDAY...THE MODELS CONTINUE TO STRUGGLE
WITH THE TIMING OF THE COLD FRONT THROUGH THE REGION. THE GFS
CONTINUES TO THE FASTEST...AND IT HAS THE FRONT THROUGH THE ENTIRE
AREA BY EARLY AFTERNOON. MEANWHILE THE OTHER MODELS SUGGEST THAT
THIS WILL NOT OCCUR UNTIL SUNDAY EVENING. THE MAIN DIFFERENCE IS
HOW FAST THEY MOVE THE POSITIVELY TILTED SHORTWAVE TROUGH THE
REGION. WITH THE GFS BEING FASTER WITH THIS FEATURE...IT MAKES
SENSE THAT ITS FRONT WOULD MOVE THROUGH THE REGION FASTER. DUE TO
THIS WENT WITH MORE OF BLEND FOR THE WINDS...PRECIPITATION
CHANCES...AND TEMPERATURES. WITH ALL OF THE MODELS HINTING THAT
THE BEST MOISTURE TRANSPORT WOULD BE MAINLY NORTH AND NORTHWEST OF
THE FORECAST AREA...AS A RESULT TRENDED THE HIGHEST PRECIPITATION
CHANCES FOR THESE AREAS. WHILE ML CAPES CLIMB INTO THE 1500 TO
2500 J/KG...THE 0-6 KM BULK SHEAR IS LESS THAN 30 KNOTS...SO STILL
NOT THINKING THAT THERE WILL ANY SEVERE WEATHER FROM ANY OF THESE
STORMS.
.LONG TERM...MONDAY THROUGH FRIDAY
343 PM CDT FRI MAY 18 2012
THE 18.12Z MODELS ARE STARTING TO BECOME MORE IN AGREEMENT. THEY
SHOW THAT A COLD FRONT WILL SAG SOUTHWARD INTO THE AREA ON WEDNESDAY
NIGHT AND THEN LINGER ACROSS THE AREA THROUGH FRIDAY MORNING...AND
THEN MOVE NORTH AS A WARM FRONT ON FRIDAY AFTERNOON AND NIGHT.
THE LATTER IS ASSOCIATED WITH A RIDGE BUILDING ACROSS THE EASTERN
UNITED STATES. SINCE THE LATTER HAS BEEN VERY CONSISTENT IN THE
ECMWF...THERE WAS ENOUGH CONFIDENCE TO RAISE THE TEMPERATURES A
COUPLE OF DEGREES ABOVE THE CONSALL FOR LATE NEXT WEEK.
&&
.AVIATION...THROUGH 06Z SUNDAY
1145 PM CDT FRI MAY 18 2012
SOUTHERLY FLOW WILL CONTINUE AT THE TAF SITES THROUGH THE PERIOD.
VFR CONDITIONS ARE EXPECTED THOUGH 06Z SATURDAY. WINDS HAVE
DECOUPLED AT KLSE WITH SURFACE WINDS AROUND 10 KNOTS. KARX VAD
WIND PROFILER SHOWS 2000 FOOT WINDS AT 40 KNOTS AND BOTH THE
19.02Z RAP AND 19.00Z NAM BUFKIT SOUNDINGS SHOWING 35 TO 40 KNOT
WINDS CONTINUING JUST OFF THE SURFACE. THUS DID INCLUDE LLWS AT
THE KLSE SITE THROUGH 14Z. LOW LEVEL WINDS AT KRST WILL BE MARGINAL
FOR LLWS AND WILL NOT INCLUDE. WINDS WILL PICK UP ONCE AGAIN
SATURDAY WITH SOME GUSTS TO 30 KNOTS AT KRST AND NEAR 25 KNOTS AT
KLSE. A COLD FRONT WILL THEN MOVE INTO WESTERN MINNESOTA DURING
THE AFTERNOON AND EVENING HOURS. DID MENTION VCSH AT KRST AFTER
01Z AS FRONT APPROACHES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
253 PM CDT FRI MAY 18 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS NEW YORK NY
554 AM EDT MON MAY 21 2012
.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH
TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY...FOLLOWED
BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS
THEREAFTER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR INDICATES MODERATE TO HEAVY SHOWERS MOVING FROM SOUTHEAST TO
NORTHWEST...CLIPPING PORTIONS OF THE AREA NEAR STATEN ISLAND..AND
ESSEX/UNION COUNTIES OF NJ. JUST ENOUGH INSTABILITY ALOFT TO
WARRANT THUNDER MENTION...MAINLY WESTERN PORTIONS OF THE CWA.
HRRR AND RAP IN THE NEAR TERM SHOWS SHOWER COVERAGE EVER SO SLOWLY
INCREASES FROM THE SOUTH THIS MORNING. COULD TAKE SOMETIME FOR
INTERIOR ZONES TO SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL
LIKELY COVERAGE IS WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA.
OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES
SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150
TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT
EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT
WILL RESULT IN SHOWERS TODAY...POSSIBLE THUNDER...AND PLENTY OF
CLOUDS.
MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND
FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. 00Z NAM
SOLUTION WAS DISCARDED FOR THIS FORECAST. 00Z NAM FORECASTS A
DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN
ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY.
QUICK LOOK AT 06Z NAM...THE LOW HAS SHIFTED EAST CLOSER TO OTHER
MODEL SOLUTIONS.
IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE
THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL
HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK
FORECASTS AND DISCUSSIONS REGARDING ALBERTO.
ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE
FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE
TONIGHT/EARLY TUESDAY.
BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK
TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN
COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES
NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY
HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE
JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR.
BACKING UP A BIT...IF 00Z NAM PROVES TO BE CORRECT...HEAVIER RAIN
WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY
TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME.
TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE
FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD
REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR
THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES
THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY
STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE
ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD
FRONT LATE FRIDAY.
T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT
FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE
LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST
INFORMATION ON ALBERTO.
WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER
THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY
LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG
DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE
OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD
FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF
INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS
THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL
CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT
EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO
LOWER 80S DESPITE THE CLOUDS/MORNING FOG.
WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE
MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF
THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS
TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK
SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS
INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER.
THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD.
NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE
REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD
THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL
OFFSHORE. CIGS OF MVFR TO IFR WILL TREND MORE IFR THIS MORNING
AS SHOWER COVERAGE INCREASES. LOOKING FOR THIS TO STAY WITH A
CHANCE OF IMPROVEMENT TO LOW END MVFR...1-2KFT IN THE AFTERNOON
FOR SOME TERMINALS AWAY FROM THE COAST BUT THINK THIS IS QUITE LOW
AT THE MOMENT. THEREFORE IFR CONTINUES IN THE TAFS WITH PERIODIC
SHOWERS TODAY. VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM
FORECAST. FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR
TODAY.
NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT.
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)
KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KEWR FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN
FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN
SHOWERS COULD OCCASIONALLY DROP TO IFR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN
FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN
SHOWERS COULD OCCASIONALLY DROP TO IFR.
KHPN FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN
FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN
SHOWERS COULD OCCASIONALLY DROP TO IFR.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
.TONIGHT...MVFR OR IFR IN RAIN/FOG. LOWER CONDITIONS POSSIBLE.
.TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM
WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT.
.THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN
SHOWERS ON FRIDAY.
&&
.MARINE...
SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN
WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND
SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE
HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE.
A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER
THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN
TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON
TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA.
&&
.HYDROLOGY...
OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH
ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY.
SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD
RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY
HEAVIER SHOWERS.
AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR
LOCATION CONTINUE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MPS/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...MPS
AVIATION...JM
MARINE...MPS/PW
HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
511 AM EDT MON MAY 21 2012
.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH
TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY...FOLLOWED
BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS
THEREAFTER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HRRR AND RAP IN THE NEAR TERM SHOWS SHOWER COVERAGE EVER SO SLOWLY
INCREASES FROM THE SOUTH THIS MORNING. COULD TAKE SOMETIME FOR
INTERIOR ZONES TO SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL
LIKELY COVERAGE IS WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA.
OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES
SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150
TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT
EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT
WILL RESULT IN SHOWERS TODAY...AND PLENTY OF CLOUDS.
MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND
FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. NAM SOLUTION
WAS DISCARDED FOR THIS FORECAST. NAM FORECASTS A DEEPER MID LEVEL
LOW...AND TRACKS THE SFC LOW FROM THE WESTERN ATLANTIC TO JUST EAST
OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY. IT IS IMPORTANT TO NOTE
THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE THE LATEST ADVISORIES
REGARDING ALBERTO FROM THE NATIONAL HURRICANE CENTER. REFER TO NHC
FOR THE LATEST ADVISORIES...TRACK FORECASTS AND DISCUSSIONS
REGARDING ALBERTO.
ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE
FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE
TONIGHT/EARLY TUESDAY.
BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK
TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN
COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES
NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY
HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE
JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR.
BACKING UP A BIT...IF NAM PROVES TO BE CORRECT...HEAVIER RAIN WILL
MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY TUESDAY...BUT
AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME.
TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE
FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD
REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR
THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES
THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY
STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE
ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD
FRONT LATE FRIDAY.
T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT
FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE
LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST
INFORMATION ON ALBERTO.
WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER
THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY
LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG
DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE
OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD
FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF
INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS
THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL
CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT
EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO
LOWER 80S DESPITE THE CLOUDS/MORNING FOG.
WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE
MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF
THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS
TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK
SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS
INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER.
THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD.
NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE
REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD
THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL
OFFSHORE. CIGS OF MVFR TO IFR WILL TREND MORE IFR THIS MORNING
AS SHOWER COVERAGE INCREASES. LOOKING FOR THIS TO STAY WITH A
CHANCE OF IMPROVEMENT TO LOW END MVFR...1-2KFT IN THE AFTERNOON
FOR SOME TERMINALS AWAY FROM THE COAST BUT THINK THIS IS QUITE LOW
AT THE MOMENT. THEREFORE IFR CONTINUES IN THE TAFS WITH PERIODIC
SHOWERS TODAY. VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM
FORECAST. FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR
TODAY.
NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT.
...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)
KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KEWR FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN
FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN
SHOWERS COULD OCCASIONALLY DROP TO IFR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN
FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN
SHOWERS COULD OCCASIONALLY DROP TO IFR.
KHPN FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN
FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN
SHOWERS COULD OCCASIONALLY DROP TO IFR.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
.TONIGHT...MVFR OR IFR IN RAIN/FOG. LOWER CONDITIONS POSSIBLE.
.TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM
WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT.
.THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN
SHOWERS ON FRIDAY.
&&
.MARINE...
SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN
WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND
SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE
HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE.
A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER
THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN
TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON
TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA.
&&
.HYDROLOGY...
OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH
ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY.
SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD
RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY
HEAVIER SHOWERS.
AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR
LOCATION CONTINUE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MPS/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...MPS
AVIATION...JM
MARINE...MPS/PW
HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
327 AM EDT MON MAY 21 2012
.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH
TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY...FOLLOWED
BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS
THEREAFTER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HRRR AND RAP IN THE NEAR TERM SHOWS SHOWER COVERAGE EVER SO SLOWLY
INCREASES FROM THE SOUTH THIS MORNING. COULD TAKE SOMETIME FOR
INTERIOR ZONES TO SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL
LIKELY COVERAGE IS WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA.
OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES
SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150
TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT
EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT
WILL RESULT IN SHOWERS TODAY...AND PLENTY OF CLOUDS.
MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND
FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. NAM SOLUTION
WAS DISCARDED FOR THIS FORECAST. NAM FORECASTS A DEEPER MID LEVEL
LOW...AND TRACKS THE SFC LOW FROM THE WESTERN ATLANTIC TO JUST EAST
OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY. IT IS IMPORTANT TO NOTE
THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE THE LATEST ADVISORIES
REGARDING ALBERTO FROM THE NATIONAL HURRICANE CENTER. REFER TO NHC
FOR THE LATEST ADVISORIES...TRACK FORECASTS AND DISCUSSIONS
REGARDING ALBERTO.
ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE
FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE
TONIGHT/EARLY TUESDAY.
BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK
TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN
COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES
NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY
HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE
JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR.
BACKING UP A BIT...IF NAM PROVES TO BE CORRECT...HEAVIER RAIN WILL
MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY TUESDAY...BUT
AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME.
TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE
FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD
REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR
THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES
THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY
STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE
ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD
FRONT LATE FRIDAY.
T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT
FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE
LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST
INFORMATION ON ALBERTO.
WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER
THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY
LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG
DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE
OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD
FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF
INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS
THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL
CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT
EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO
LOWER 80S DESPITE THE CLOUDS/MORNING FOG.
WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE
MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF
THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS
TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK
SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS
INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER.
THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD.
NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE
REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD
THROUGH TODAY. CIGS OF MVFR TO ISOLATED IFR WILL TREND MORE IFR
TOWARDS DAYBREAK NEAR THE ONSET OF SHOWERS. LOOKING FOR THIS TO
STAY WITH A CHANCE OF IMPROVEMENT TO LOW END MVFR...1-2KFT IN THE
AFTERNOON BUT THINK THIS IS QUITE LOW AT THE MOMENT. THEREFORE IFR
CONTINUES IN THE TAFS WITH PERIODIC SHOWERS. VSBYS LARGE UNCERTAINTY
WITHIN SHOWERS AND COULD VARY BY A FEW MILES FROM FORECAST. FORECAST
HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY. TIMING OF
ONSET OF SHOWERS HAS A 1 TO 2 HOUR UNCERTAINTY.
WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT FROM THE EAST ON
AVERAGE.
.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
.TONIGHT...MVFR OR IFR IN RAIN. LOWER CONDITIONS POSSIBLE.
.TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM
WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT.
.THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN
SHOWERS ON FRIDAY.
&&
.MARINE...
SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN
WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND
SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE
HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE.
A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER
THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN
TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON
TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA.
&&
.HYDROLOGY...
OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH
ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY.
SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD
RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY
HEAVIER SHOWERS.
AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR
LOCATION CONTINUE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MPS/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...MPS
AVIATION...JM
MARINE...MPS/PW
HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
206 AM EDT MON MAY 21 2012
.SYNOPSIS...
HIGH PRESSURE DEPARTS TODAY. A WAVE OF LOW PRESSURE WILL MOVE
TOWARD THE AREA AND REMAIN LATER TODAY BEFORE MOVING TO THE
NORTHEAST TONIGHT. A SERIES OF WEAK LOW PRESSURE SYSTEMS WILL
CREATE UNSETTLED CONDITIONS ACROSS THE TRI-STATE INTO WEDNESDAY.
A COLD FRONT WILL PUSH INTO THE REGION LATE WEDNESDAY...THEN STALL
OUT NEARBY INTO FRIDAY. ANOTHER COLD FRONT APPROACHES FROM THE
NORTHWEST FRIDAY NIGHT...THEN MOVES ACROSS THE AREA SATURDAY AND
SATURDAY EVENING. HIGH PRESSURE THEN BUILDS DOWN FROM CANADA INTO
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATES INCLUDE FURTHER ADJUSTMENTS TO MAINLY SKY/POP/TEMP AND
DEWPOINT GRIDS. NOW LOOKS CHANCES OF RAINFALL WILL BE LATE AT
NIGHT. LIKELIHOOD OF SHOWERS PROBABLY DOESN`T ARRIVE UNTIL AROUND
DAYBREAK FOR THE SOUTHERNMOST PORTIONS OF THE CWA...BUT ISOLATED TO
SCATTERED SHOWERS ARE EXPECTED TO BE IN THE VICINITY AFTER
MIDNIGHT. MOST RECENT RUNS OF THE HRRR AND RUC MODELS GENERALLY
AGREE WITH THIS TREND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
TROPICAL STORM ALBERTO DOES NOT HAVE A DIRECT IMPACT TO THE LOCAL
AREA BASED ON THE LATEST MODEL GUIDANCE AND TRACK FORECAST FROM THE
NATIONAL HURRICANE CENTER. PLEASE REFER TO NHC FOR THE LATEST
ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING TROPICAL
STORM ALBERTO.
SYNOPTIC FEATURES REMAIN WEAK THROUGH MONDAY NIGHT AS BROAD UPPER
TROUGH REMAINS ALONG THE EASTERN PORTION OF THE COUNTRY. WAVES OF
LOW PRESSURE MOVE ALONG THE COAST THROUGH THE PERIOD. CURRENT
THINKING IS THE BEST CHANCE OF PRECIPITATION IS DURING THE DAY
MONDAY AND INTO THE EARLY EVENING WITH THE BEST SYNOPTIC
FORCING...ALTHOUGH WEAK. PRECIPITABLE WATER VALUES INCREASE TO
AROUND 1.5 INCHES DURING THIS PERIOD AND IS ABOUT 170 PERCENT OF
NORMAL. SO WENT WITH MODERATE SHOWERS. MARINE LAYER WILL BE IN
PLACE MONDAY AND MONDAY NIGHT WITH THE AREA STABLE SO WILL NOT
MENTION THUNDER.
WITH CLOUDS...EAST FLOW AND RAIN...LEANED TOWARD THE LOWER NAM
GUIDANCE FOR HIGHS MONDAY...AND USED A BLEND FOR MONDAY NIGHTS
LOWS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MODELS ARE IN MUCH BETTER AGREEMENT THAN YESTERDAY FOR THE MID
TO LATE WEEK TIME FRAME. USED A BLEND OF THE NAM/SREF/ECMWF/GFS FOR
THE FORECAST TUESDAY-WEDNESDAY AND THE GFS/ECMWF/CMC-GLOBAL
WEDNESDAY NIGHT-SUNDAY.
T.S. ALBERTO IS EXPECTED TO HAVE NO DIRECT IMPACT ON THE
REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA
BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE
CENTER FOR THE LATEST INFORMATION ON ALBERTO.
A SERIES OF WEAK SHORTWAVES CROSS THE AREA TUESDAY-THURSDAY NIGHT.
DURING THIS TIME FRAME...WILL JUST BE IN A MOIST/RELATIVELY HUMID
ENVIRONMENT...WITH AN ONSHORE FLOW PROMOTING A MARINE LAYER AND
CLOUD COVER NEAR THE COAST...WITH LESS OF AN INFLUENCE/CLOUDS OVER
THE INTERIOR. WITH MORE INSTABILITY EXPECTED INLAND...HAVE GONE WITH
CHANCE POPS ACROSS THE INTERIOR AND SLIGHT CHANCE POPS OVER COASTAL
AREAS DURING THE DAY AND SLIGHT CHANCE POPS AT NIGHT. HAVE A CHANCE
OF THUNDER DURING THE DAY TUESDAY/WEDNESDAY ACROSS INTERIOR ZONES AS
WELL WITH SOME MARGINAL INSTABILITY EXPECTED. WITH A RATHER DIFFUSE
FRONT DISSIPATING OVER THE REGION FRIDAY...ONLY HAVE SLIGHT CHANCE
POPS OVER THE INTERIOR THEN.
WITH PERSISTENT ONSHORE FLOW EXPECTED INTO WEDNESDAY...HAVE FOG IN
EARLY TUESDAY MORNING...AND AGAIN FROM LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING.
WITH A SHORTWAVE FORECAST TO PASS THROUGH FRIDAY NIGHT...HAVE SLIGHT
CHANCE POPS THROUGHOUT. WITH THE APPROACH/PASSAGE OF A COLD FRONT
SATURDAY...HAVE A CHANCE OF THUNDER THROUGHOUT...TAPERING TO A DRY
FORECAST BY SUNDAY AS RIDGING BEGINS TO BUILD IN.
FOR TEMPERATURES...USED A BLEND OF MAV/MET GUIDANCE/NAM 2-METER
TEMPERATURES AND MIXING DOWN FROM 950 HPA FOR HIGHS ON
TUESDAY...WITH VALUES FORECAST SLIGHTLY ABOVE NORMAL. FOR LOWS
TUESDAY NIGHT USED A BLEND OF BIAS CORRECTED MAV GUIDANCE WITH MET
GUIDANCE AND NAM 2-METER TEMPERATURES...WHICH YIELDED VALUES AROUND
5 DEGREES ABOVE NORMAL. FOR HIGHS WEDNESDAY USED A BLEND OF MIXING
DOWN FROM 925 HPA NEAR THE COAST...850 HPA INLAND...WITH NAM 2-METER
TEMPERATURES...AND MEX GUIDANCE. THIS YIELDS VALUES 5 TO 10 DEGREES
ABOVE NORMAL. FROM WEDNESDAY NIGHT-SUNDAY BLENDED 18Z HPC GUIDANCE
WITH A MEX/MEX ENSEMBLE MEAN BLEND. THIS YIELDED ABOVE NORMAL
TEMPERATURES THROUGH THIS TIME FRAME.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD
THROUGH TODAY. CIGS OF MVFR TO ISOLATED IFR WILL TREND MORE IFR
TOWARDS DAYBREAK NEAR THE ONSET OF SHOWERS. LOOKING FOR THIS TO
STAY WITH A CHANCE OF IMPROVEMENT TO LOW END MVFR...1-2KFT IN THE
AFTERNOON BUT THINK THIS IS QUITE LOW AT THE MOMENT. THEREFORE IFR
CONTINUES IN THE TAFS WITH PERIODIC SHOWERS. VSBYS LARGE UNCERTAINTY
WITHIN SHOWERS AND COULD VARY BY A FEW MILES FROM FORECAST. FORECAST
HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY. TIMING OF
ONSET OF SHOWERS HAS A 1 TO 2 HOUR UNCERTAINTY.
WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT FROM THE EAST ON
AVERAGE.
.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
.TONIGHT...MVFR OR IFR IN RAIN. LOWER CONDITIONS POSSIBLE.
.TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM
WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT.
.THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN
SHOWERS ON FRIDAY.
&&
.MARINE...
FORECAST APPEARS ON TRACK. A EAST TO SOUTHEAST SWELL WILL
CONTINUE ACROSS THE OCEAN WATERS THROUGH AT LEAST TONIGHT AS
LOW PRESSURE ALONG THE MID ATLANTIC COAST BEGINS TO MOVE TO THE
NORTHEAST. WINDS ACROSS THE FORECAST WATERS WILL REMAIN BELOW
SMALL CRAFT LEVELS THROUGH THE PERIOD WITH A WEAK PRESSURE
GRADIENT. THE SMALL CRAFT FOR HAZARDOUS SEAS REMAINS EXTENDED
THROUGH TONIGHT AS SEAS WILL REMAIN AROUND 5 FT THROUGH THE TIME
FRAME.
A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER
THE COASTAL OCEAN WATERS FROM TUESDAY INTO WEDNESDAY...BUT WITH THE
WINDS VEERING FROM SE ON TUESDAY TO S-SW BY WEDNESDAY...EXPECT SEAS
TO BEGIN TO DIMINISH STARTING TUESDAY NIGHT. OTHERWISE...WITH A
RELATIVELY LIGHT PRESSURE GRADIENT FORECAST ACROSS THE AREA EXPECT
CONDITIONS TO REMAIN WELL BELOW SCA THRESHOLDS FROM TUESDAY INTO
FRIDAY.
&&
.HYDROLOGY...
GENERALLY LIGHT PRECIPITATION IS EXPECTED TODAY AND CONTINUES
THROUGH AT LEAST TONIGHT. THE BULK OF THE PRECIPITATION WILL LIKELY
OCCUR DURING THE DAY MONDAY. TOTAL PRECIPITATION THROUGH TONIGHT
WILL RANGE FROM AROUND A THIRD OF AN INCH FAR WESTERN SECTIONS TO
AROUND TWO THIRDS OF AN INCH ACROSS MUCH OF THE CWA.
THERE IS SOME POTENTIAL FOR SIGNIFICANT RAINFALL INTO THE MIDDLE OF
THE WEEK. THERE IS STILL QUITE A BIT OF UNCERTAINTY AS TO EXACTLY
HOW MUCH OF THIS TIME FRAME WILL ACTUALLY HAVE PRECIPITATION
FALL...AND HOW INTENSE IT WILL BE. IT IS APPEARING MORE LIKELY
THOUGH THAT IF THERE IS ANY HEAVY RAINFALL...IT MOST LIKELY WILL
BE FROM NYC ON N AND W. HOWEVER WITH PRECIPITABLE WATERS FORECAST
TO BE 150-175% ABOVE NORMAL IN THIS TIME FRAME...AND THE POTENTIAL
FOR CONVECTION...AREAS OF LOCALLY HEAVY RAINFALL CANNOT BE RULED
OUT ANY WHERE ACROSS THE CWA.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT TUESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MALOIT/MET
NEAR TERM...JC/MALOIT/LN
SHORT TERM...MET
LONG TERM...MALOIT
AVIATION...JM
MARINE...MALOIT/MET
HYDROLOGY...MALOIT/MET
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1244 AM EDT MON MAY 21 2012
.SYNOPSIS...
HIGH PRESSURE DEPARTS TODAY. A WAVE OF LOW PRESSURE WILL MOVE
TOWARD THE AREA AND REMAIN LATER TODAY BEFORE MOVING TO THE
NORTHEAST TONIGHT. A SERIES OF WEAK LOW PRESSURE SYSTEMS WILL
CREATE UNSETTLED CONDITIONS ACROSS THE TRI-STATE INTO WEDNESDAY.
A COLD FRONT WILL PUSH INTO THE REGION LATE WEDNESDAY...THEN STALL
OUT NEARBY INTO FRIDAY. ANOTHER COLD FRONT APPROACHES FROM THE
NORTHWEST FRIDAY NIGHT...THEN MOVES ACROSS THE AREA SATURDAY AND
SATURDAY EVENING. HIGH PRESSURE THEN BUILDS DOWN FROM CANADA INTO
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATES INCLUDE FURTHER ADJUSTMENTS TO MAINLY SKY/POP/TEMP AND
DEWPOINT GRIDS. NOW LOOKS CHANCES OF RAINFALL WILL BE LATE AT
NIGHT. LIKELIHOOD OF SHOWERS PROBABLY DOESN`T ARRIVE UNTIL AROUND
DAYBREAK FOR THE SOUTHERNMOST PORTIONS OF THE CWA...BUT ISOLATED TO
SCATTERED SHOWERS ARE EXPECTED TO BE IN THE VICINITY AFTER
MIDNIGHT. MOST RECENT RUNS OF THE HRRR AND RUC MODELS GENERALLY
AGREE WITH THIS TREND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
TROPICAL STORM ALBERTO DOES NOT HAVE A DIRECT IMPACT TO THE LOCAL
AREA BASED ON THE LATEST MODEL GUIDANCE AND TRACK FORECAST FROM THE
NATIONAL HURRICANE CENTER. PLEASE REFER TO NHC FOR THE LATEST
ADVISORIES...TRACK FORECASTS AND DISCUSSIONS REGARDING TROPICAL
STORM ALBERTO.
SYNOPTIC FEATURES REMAIN WEAK THROUGH MONDAY NIGHT AS BROAD UPPER
TROUGH REMAINS ALONG THE EASTERN PORTION OF THE COUNTRY. WAVES OF
LOW PRESSURE MOVE ALONG THE COAST THROUGH THE PERIOD. CURRENT
THINKING IS THE BEST CHANCE OF PRECIPITATION IS DURING THE DAY
MONDAY AND INTO THE EARLY EVENING WITH THE BEST SYNOPTIC
FORCING...ALTHOUGH WEAK. PRECIPITABLE WATER VALUES INCREASE TO
AROUND 1.5 INCHES DURING THIS PERIOD AND IS ABOUT 170 PERCENT OF
NORMAL. SO WENT WITH MODERATE SHOWERS. MARINE LAYER WILL BE IN
PLACE MONDAY AND MONDAY NIGHT WITH THE AREA STABLE SO WILL NOT
MENTION THUNDER.
WITH CLOUDS...EAST FLOW AND RAIN...LEANED TOWARD THE LOWER NAM
GUIDANCE FOR HIGHS MONDAY...AND USED A BLEND FOR MONDAY NIGHTS
LOWS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MODELS ARE IN MUCH BETTER AGREEMENT THAN YESTERDAY FOR THE MID
TO LATE WEEK TIME FRAME. USED A BLEND OF THE NAM/SREF/ECMWF/GFS FOR
THE FORECAST TUESDAY-WEDNESDAY AND THE GFS/ECMWF/CMC-GLOBAL
WEDNESDAY NIGHT-SUNDAY.
T.S. ALBERTO IS EXPECTED TO HAVE NO DIRECT IMPACT ON THE
REGION...EXCEPT FOR LONG PERIOD SWELLS INCREASING SURF AT AREA
BEACHES. REFER TO THE LATEST FORECASTS FROM THE NATIONAL HURRICANE
CENTER FOR THE LATEST INFORMATION ON ALBERTO.
A SERIES OF WEAK SHORTWAVES CROSS THE AREA TUESDAY-THURSDAY NIGHT.
DURING THIS TIME FRAME...WILL JUST BE IN A MOIST/RELATIVELY HUMID
ENVIRONMENT...WITH AN ONSHORE FLOW PROMOTING A MARINE LAYER AND
CLOUD COVER NEAR THE COAST...WITH LESS OF AN INFLUENCE/CLOUDS OVER
THE INTERIOR. WITH MORE INSTABILITY EXPECTED INLAND...HAVE GONE WITH
CHANCE POPS ACROSS THE INTERIOR AND SLIGHT CHANCE POPS OVER COASTAL
AREAS DURING THE DAY AND SLIGHT CHANCE POPS AT NIGHT. HAVE A CHANCE
OF THUNDER DURING THE DAY TUESDAY/WEDNESDAY ACROSS INTERIOR ZONES AS
WELL WITH SOME MARGINAL INSTABILITY EXPECTED. WITH A RATHER DIFFUSE
FRONT DISSIPATING OVER THE REGION FRIDAY...ONLY HAVE SLIGHT CHANCE
POPS OVER THE INTERIOR THEN.
WITH PERSISTENT ONSHORE FLOW EXPECTED INTO WEDNESDAY...HAVE FOG IN
EARLY TUESDAY MORNING...AND AGAIN FROM LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING.
WITH A SHORTWAVE FORECAST TO PASS THROUGH FRIDAY NIGHT...HAVE SLIGHT
CHANCE POPS THROUGHOUT. WITH THE APPROACH/PASSAGE OF A COLD FRONT
SATURDAY...HAVE A CHANCE OF THUNDER THROUGHOUT...TAPERING TO A DRY
FORECAST BY SUNDAY AS RIDGING BEGINS TO BUILD IN.
FOR TEMPERATURES...USED A BLEND OF MAV/MET GUIDANCE/NAM 2-METER
TEMPERATURES AND MIXING DOWN FROM 950 HPA FOR HIGHS ON
TUESDAY...WITH VALUES FORECAST SLIGHTLY ABOVE NORMAL. FOR LOWS
TUESDAY NIGHT USED A BLEND OF BIAS CORRECTED MAV GUIDANCE WITH MET
GUIDANCE AND NAM 2-METER TEMPERATURES...WHICH YIELDED VALUES AROUND
5 DEGREES ABOVE NORMAL. FOR HIGHS WEDNESDAY USED A BLEND OF MIXING
DOWN FROM 925 HPA NEAR THE COAST...850 HPA INLAND...WITH NAM 2-METER
TEMPERATURES...AND MEX GUIDANCE. THIS YIELDS VALUES 5 TO 10 DEGREES
ABOVE NORMAL. FROM WEDNESDAY NIGHT-SUNDAY BLENDED 18Z HPC GUIDANCE
WITH A MEX/MEX ENSEMBLE MEAN BLEND. THIS YIELDED ABOVE NORMAL
TEMPERATURES THROUGH THIS TIME FRAME.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE REMAINS JUST OFF THE NEW ENGLAND COAST AS WEAK LOW
PRESSURE DRIFTS NORTHWARD TONIGHT AND MONDAY.
1000-2000 FT CEILINGS HAVE ARRIVED OVER SOME OF THE SOUTHERN
TERMINALS. EXPECTING REST THE OF THE TERMINALS TO HAVE SIMILAR
CEILINGS BY 05Z-08Z...WITH IFR CEILINGS FOR AT LEAST KJFK AND KISP
BY THIS PERIOD. FORECAST TIMING OF OTHER TERMINALS DROPPING TO IFR
CONDITIONS MAY BE COUPLE HOURS TOO SLOW. AS FOR LIKELIHOOD OF
SHOWERS...LOOKS TO BE TOWARDS DAYBREAK FOR THE CITY/SOUTHERN
TERMINALS...BUT KJFK MAY PICK UP BRIEF MOMENTS OF DRIZZLE
BEFOREHAND.
.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
.MONDAY NIGHT...MVFR OR IFR IN RAIN.
.TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM
WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT.
.THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN
SHOWERS ON FRIDAY.
&&
.MARINE...
FORECAST APPEARS ON TRACK. A EAST TO SOUTHEAST SWELL WILL
CONTINUE ACROSS THE OCEAN WATERS THROUGH AT LEAST TONIGHT AS
LOW PRESSURE ALONG THE MID ATLANTIC COAST BEGINS TO MOVE TO THE
NORTHEAST. WINDS ACROSS THE FORECAST WATERS WILL REMAIN BELOW
SMALL CRAFT LEVELS THROUGH THE PERIOD WITH A WEAK PRESSURE
GRADIENT. THE SMALL CRAFT FOR HAZARDOUS SEAS REMAINS EXTENDED
THROUGH TONIGHT AS SEAS WILL REMAIN AROUND 5 FT THROUGH THE TIME
FRAME.
A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER
THE COASTAL OCEAN WATERS FROM TUESDAY INTO WEDNESDAY...BUT WITH THE
WINDS VEERING FROM SE ON TUESDAY TO S-SW BY WEDNESDAY...EXPECT SEAS
TO BEGIN TO DIMINISH STARTING TUESDAY NIGHT. OTHERWISE...WITH A
RELATIVELY LIGHT PRESSURE GRADIENT FORECAST ACROSS THE AREA EXPECT
CONDITIONS TO REMAIN WELL BELOW SCA THRESHOLDS FROM TUESDAY INTO
FRIDAY.
&&
.HYDROLOGY...
GENERALLY LIGHT PRECIPITATION IS EXPECTED TODAY AND CONTINUES
THROUGH AT LEAST TONIGHT. THE BULK OF THE PRECIPITATION WILL LIKELY
OCCUR DURING THE DAY MONDAY. TOTAL PRECIPITATION THROUGH TONIGHT
WILL RANGE FROM AROUND A THIRD OF AN INCH FAR WESTERN SECTIONS TO
AROUND TWO THIRDS OF AN INCH ACROSS MUCH OF THE CWA.
THERE IS SOME POTENTIAL FOR SIGNIFICANT RAINFALL INTO THE MIDDLE OF
THE WEEK. THERE IS STILL QUITE A BIT OF UNCERTAINTY AS TO EXACTLY
HOW MUCH OF THIS TIME FRAME WILL ACTUALLY HAVE PRECIPITATION
FALL...AND HOW INTENSE IT WILL BE. IT IS APPEARING MORE LIKELY
THOUGH THAT IF THERE IS ANY HEAVY RAINFALL...IT MOST LIKELY WILL
BE FROM NYC ON N AND W. HOWEVER WITH PRECIPITABLE WATERS FORECAST
TO BE 150-175% ABOVE NORMAL IN THIS TIME FRAME...AND THE POTENTIAL
FOR CONVECTION...AREAS OF LOCALLY HEAVY RAINFALL CANNOT BE RULED
OUT ANY WHERE ACROSS THE CWA.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM EDT TUESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MALOIT/MET
NEAR TERM...JC/MALOIT/LN
SHORT TERM...MET
LONG TERM...MALOIT
AVIATION...JC
MARINE...MALOIT/MET
HYDROLOGY...MALOIT/MET
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
422 AM EDT MON MAY 21 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 338 AM EDT MON MAY 21 2012
SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY
WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH
PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR
TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL
BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL
BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE
WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE
HOTTEST TEMPERATURES OF THE YEAR SO FAR.
&&
.NEAR TERM /TODAY/...
ISSUED AT 338 AM EDT MON MAY 21 2012
WELL DEFINED OUTFLOW FROM EARLIER CONVECTION MOVING INTO WESTERN
OHIO AS OF 07Z WITH WEAKENING SCATTERED CONVECTION LEFT IN ITS WAKE
OVER THE FORECAST AREA. ACTUAL COLD FRONT STILL WEST OF THE REGION
OVER CENTRAL ILLINOIS EARLY THIS MORNING. TEMPS WERE IN THE 60S AS
OF 07Z.
AS MENTIONED ABOVE...THE FRONTAL BOUNDARY APPEARS TO BE ALIGNED
ROUGHLY FROM JUST EAST OF KORD SOUTHWEST TO NEAR KSTL. THE PASSAGE
OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT TO NORTHWEST
WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA DURING THE
COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO DIMINISH EARLY
THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT IS LIMITED.
CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL DECREASE OVER
THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY ALONG AND AHEAD
OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY BY MID/LATE MORNING
OVER THE EASTERN HALF OF THE FORECAST AREA. HAVE FOCUSED HIGHEST
POPS SOUTH AND EAST OF THE INDY METRO WHERE COMBINATION OF THE
INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD PROMOTE LARGELY
DISORGANIZED AND SCATTERED CONVECTION INTO THE AFTERNOON.
WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO
ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES
INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE
AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING
INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL
ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST
INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE
FORECAST AREA.
TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE
FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH
LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS
AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 338 AM EDT MON MAY 21 2012
FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING
TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT.
UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT...
EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST
STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD
OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO
WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS.
THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD
COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW
LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK
SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA...
INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH
MOSTLY SUNNY SKIES EXPECTED.
RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND
WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN
APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE
OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE
ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES
WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT
WILL CONTINUE THROUGH THE REST OF THE WEEK.
TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH
TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS
WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP
INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES
WITH 50S ELSEWHERE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON MAY 21 2012
MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT
GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN
BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN
KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE
PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT
WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH
THIS PACKAGE.
THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND
REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND
DEWPOINTS AND SKY COVER AS NECESSARY.
UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO
THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY
WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT
INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD
SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM
REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO.
&&
.AVIATION /DISCUSSION FOR THE 210830Z TAF UPDATE/...
ISSUED AT 422 AM EDT MON MAY 21 2012
TS HAS ENDED ACROSS THE AREA SO REMOVED MENTION IN THE TAF. THERE
WILL STILL BE SCATTERED LIGHT SHOWERS...BUT STILL EXPECT VFR
CONDITIONS IN THEM. WINDS HAVE BECOME LIGHT AND VARIABLE AHEAD OF
THE COLD FRONT...BUT THEY WILL STILL BECOME NORTHWEST LATER THIS
MORNING AS THE FRONT MOVES THROUGH.
RELEVANT PORTION OF PREVIOUS DISCUSSION FOLLOWS...
LOWER END VFR CEILINGS SHOULD DEVELOP AT ALL SITES OVERNIGHT AND
THEN PERSIST INTO THE DAY MONDAY AS COLD FRONT PASSES. DRIER AIR
WILL THEN SCATTER OUT THE CLOUDS DURING THE AFTERNOON.
WIND DIRECTION WILL GENERALLY BE OUT OF THE NORTHWEST. THERE COULD
BE SOME VARIATION EARLY IN THE PERIOD UNTIL ACTUAL COLD FRONT
PASSES. WIND SPEEDS WILL REMAIN AT 10 TO 15KT THROUGH THE DAY
MONDAY...DIMINISHING SOME AFTER SUNSET.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....50
AVIATION...TDUD/50
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
338 AM EDT MON MAY 21 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 338 AM EDT MON MAY 21 2012
SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY
WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH
PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR
TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL
BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL
BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE
WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE
HOTTEST TEMPERATURES OF THE YEAR SO FAR.
&&
.NEAR TERM /TODAY/...
ISSUED AT 338 AM EDT MON MAY 21 2012
WELL DEFINED OUTFLOW FROM EARLIER CONVECTION MOVING INTO WESTERN
OHIO AS OF 07Z WITH WEAKENING SCATTERED CONVECTION LEFT IN ITS WAKE
OVER THE FORECAST AREA. ACTUAL COLD FRONT STILL WEST OF THE REGION
OVER CENTRAL ILLINOIS EARLY THIS MORNING. TEMPS WERE IN THE 60S AS
OF 07Z.
AS MENTIONED ABOVE...THE FRONTAL BOUNDARY APPEARS TO BE ALIGNED
ROUGHLY FROM JUST EAST OF KORD SOUTHWEST TO NEAR KSTL. THE PASSAGE
OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT TO NORTHWEST
WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA DURING THE
COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO DIMINISH EARLY
THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT IS LIMITED.
CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL DECREASE OVER
THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY ALONG AND AHEAD
OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY BY MID/LATE MORNING
OVER THE EASTERN HALF OF THE FORECAST AREA. HAVE FOCUSED HIGHEST
POPS SOUTH AND EAST OF THE INDY METRO WHERE COMBINATION OF THE
INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD PROMOTE LARGELY
DISORGANIZED AND SCATTERED CONVECTION INTO THE AFTERNOON.
WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO
ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES
INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE
AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING
INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL
ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST
INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE
FORECAST AREA.
TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE
FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH
LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS
AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 338 AM EDT MON MAY 21 2012
FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING
TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT.
UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT...
EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST
STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD
OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO
WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS.
THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD
COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW
LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK
SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA...
INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH
MOSTLY SUNNY SKIES EXPECTED.
RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND
WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN
APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE
OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE
ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES
WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT
WILL CONTINUE THROUGH THE REST OF THE WEEK.
TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH
TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS
WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP
INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES
WITH 50S ELSEWHERE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON MAY 21 2012
MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT
GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN
BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN
KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE
PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT
WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH
THIS PACKAGE.
THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND
REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND
DEWPOINTS AND SKY COVER AS NECESSARY.
UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO
THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY
WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT
INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD
SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM
REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO.
&&
.AVIATION /DISCUSSION FOR THE 210600Z TAFS/...
ISSUED AT 105 AM EDT MON MAY 21 2012
CONVECTION SHOULD IMPACT KIND AND KBMG EARLY IN THE PERIOD BEFORE IT
DIMINISHES OVERNIGHT. LOOKS LIKE MVFR CONDITIONS IN TSRA HERE WITH
VFR OUTSIDE OF TSRA. CANNOT RULE OUT BRIEF PERIOD OF IFR IF A
HEAVIER CELL HITS AN AIRPORT.
AT KLAF/KHUF ONLY SCATTERED SHOWERS LOOK TO BE AROUND EARLY IN THE
PERIOD.
LOWER END VFR CEILINGS SHOULD THEN DEVELOP AT ALL SITES OVERNIGHT
AND THEN PERSIST INTO THE DAY MONDAY AS COLD FRONT PASSES. DRIER AIR
WILL THEN SCATTER OUT THE CLOUDS DURING THE AFTERNOON.
WIND DIRECTION WILL GENERALLY BE OUT OF THE NORTHWEST. THERE COULD
BE SOME VARIATION EARLY IN THE PERIOD UNTIL ACTUAL COLD FRONT
PASSES. WIND SPEEDS WILL REMAIN AT 10 TO 15KT THROUGH THE DAY
MONDAY...DIMINISHING SOME AFTER SUNSET.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....50
AVIATION...TDUD/50
AREA FORECAST DISCUSSION
NWS HASTINGS NE
447 AM CDT MON MAY 21 2012
.SHORT TERM...ALTHOUGH THE MAJORITY OF THE NEXT 72 HOURS SHOULD
REMAIN DRY...WILL HAVE TO DEAL WITH AT LEAST SOME SPRINKLES/BRIEF
SHOWERS THIS MORNING MAINLY IN THE NORTH...AND EVENTUALLY WHAT
SHOULD BE A MORE WIDESPREAD THUNDERSTORM RISK IN SOME AREAS
WEDNESDAY EVENING/NIGHT. ALSO OF CONCERN IS POSSIBLE
ADVISORY-LEVEL SOUTHERLY WIND ON TUESDAY.
08Z OBJECTIVE SURFACE ANALYSIS PLACES A BROAD 1025MB RIDGE AXIS
ACROSS EASTERN NEB...PROVIDING NEAR CALM TO VERY LIGHT
EAST/SOUTHEAST BREEZES TO THE CWA. ALTHOUGH MID LEVEL CLOUDS WILL
BE ON THE INCREASE THROUGH SUNRISE...MAINLY CLEAR SKIES THUS FAR
TONIGHT HAVE RESULTED IN AN EFFICIENT COOL DOWN INTO THE MID/UPPER
40S IN MOST AREAS. SPEAKING OF THOSE INCOMING MID CLOUDS AND
INCORPORATING RADAR TRENDS...SURE ENOUGH AND AS SUSPECTED HERE 24
HOURS AGO...A NARROW NORTH-SOUTH BAND OF MID-LEVEL THETA-E
ADVECTION EVIDENT AT 700MB HAS SPARKED AN AREA OF AT THE VERY
LEAST SCATTERED SPRINKLES/LIGHT SHOWERS AND EVEN A FEW WEAK
THUNDERSTORMS THAT HAVE SO FAR LARGELY STAYED JUST OUTSIDE THE CWA
ALONG AN AXIS FROM NEAR VALENTINE TO NORTH PLATTE. WATER VAPOR
IMAGERY CONFIRMS BROAD NORTHWEST FLOW ALOFT OVER THE CENTRAL
PLAINS...AS THE REGION LIES ALONG THE NORTHEAST PERIPHERY OF A
BUILDING MID/UPPER RIDGE AXIS EXTENDING ALL THE WAY BACK TO THE
PACIFIC NORTHWEST...WHERE THE NEXT LARGER SCALE SHORTWAVE/UPPER
JET STREAK OF INTEREST IS ARRIVING ON THE SCENE.
THE IMMEDIATE ISSUE THROUGH AT LEAST THE NEXT 4-6 HOURS IS THE
EVOLUTION OF DEVELOPING SHOWER ACTIVITY THIS MORNING. THIS NARROW
CORRIDOR OF HIGH BASED CONVECTION IS CLASSICALLY LOCATED ALONG THE
LEADING EDGE OF 700MB THETA-E ADVECTION...AND IMMEDIATELY EAST OF
THE CORE OF THE 850MB LOW LEVEL JET CURRENTLY CENTERED FROM FAR
WESTERN KS INTO WESTERN NEB. AS USUAL...DETERMINISTIC MODELS SUCH
AS NAM/GFS/ECMWF ARE STRUGGLING TO FULLY CAPTURE THIS ACTIVITY IN
THEIR QPF FIELDS...WHILE HIGHER RESOLUTION SHORT TERM MODELS SUCH
AS THE HRRR AND 0Z 4KM WRF-NMM ARE PROVING BETTER. OBJECTIVE RUC
ANALYSIS AND 06Z NAM CONFIRM THAT ELEVATED MUCAPE VALUES MAINLY IN
THE 800-650MB LAYER ARE ONLY RUNNING A MEAGER 100 J/KG OR SO.
FOLLOWING THE 06Z NAM...THIS BAND OF MID LEVEL THETA-E ADVECTION
SHOULD CONTINUE TO STEADILY TRACK EAST MAINLY ACROSS THE NORTHERN
1/2 OF NEB THROUGH THE MORNING HOURS...AT LEAST PUTTING PARTS OF
THE NORTHERN CWA IN LINE FOR NUISANCE AND UNFORTUNATELY PREVIOUSLY
UN-ADVERTISED PRECIPITATION. HAVE DEBATED BETWEEN GOING WITH A
MEASURABLE POP/SHOWER AND MAYBE EVEN AN ISOLATED THUNDERSTORM
MENTION...BUT AT LEAST TO START OUT WITH THIS MORNING WILL
TRY...REPEAT TRY...TO GET AWAY WITH ONLY SCATTERED SPRINKLE
MENTION ALONG AND NORTH OF I-80 WITH EXPECTATION THAT MEASURABLE
PRECIP SHOULD NOT BE OVERLY WIDESPREAD. STAY TUNED FOR POSSIBLE
UPDATES HOWEVER AS RADAR TRENDS EVOLVE. OBVIOUSLY EVEN IF ANY
ROGUE LIGHTNING STRIKES TO MANAGE TO SNEAK IN...WOULD NOT
ANTICIPATE ANYTHING CLOSE TO BEING SEVERE...WITH EVEN SMALL HAIL
HARD TO COME BY. WITH EXPECTATION OF THIS BEING A MORNING-ONLY
ISSUE...HAVE NO PRECIP MENTION WITHIN THE CWA BEYOND 17Z...AS THE
AFTERNOON HOURS WILL FEATURE THE PRIMARY LOWER LEVEL INSTABILITY
AXIS SETTING UP WEST OF THE CWA ALONG AN AXIS FROM FAR WESTERN KS
NORTHWARD INTO WESTERN NEB. MEANWHILE...SOUTH/SOUTHEAST WIND WILL
BE ON THE INCREASE AS THE DAY WEARS ON...AS THE SURFACE RIDGE AXIS
DEPARTS EAST INTO IA/MO. AS A RESULT...THE AFTERNOON HOURS WILL
FEATURE SUSTAINED SPEEDS RANGING FROM NEAR 15 MPH IN FAR EASTERN
COUNTIES...TO 20-25 MPH IN SOME WESTERN AREAS ALONG WITH GUSTS TO
AROUND 30 MPH. TEMP WISE TODAY...CHANGED HIGHS LITTLE FROM
PREVIOUS FORECAST...AND FOLLOWED 0Z NAM RAW TEMPS QUITE CLOSELY.
ALTHOUGH PASSING MID LEVEL CLOUDS THIS MORNING COULD PUT A
TEMPORARY DELAY ON THE DIURNAL CLIMB...HAVE AIMED MOST OF THE CWA
INTO THE 77-81 RANGE FOR EVENTUAL HIGHS.
THIS EVENING/TONIGHT...ANY STORMS THAT MANAGE TO FORM OUT IN
WESTERN NEB LATE THIS AFTERNOON WITHIN THE INSTABILITY AXIS SHOULD
STEADILY FADE AWAY LONG BEFORE MAKING IT INTO THE CWA. THAT BEING
SAID...HAVE OPTED TO DISREGARD THE 00Z GFS SOLUTION WHICH BREAKS
OUT WIDESPREAD QPF TONIGHT MAINLY IN SOUTHWEST/CENTRAL KS...BUT
ALSO BRUSHING UP INTO THE KS ZONES OF OUR CWA. WITH THE NAM/ECMWF
AND 4KM WRF-NMM ESSENTIALLY SHOWING NOTHING OF THIS NATURE...IT
JUST SEEMS TOO MUCH AN OUTLIER AND HAVE KEPT THE ENTIRE CWA
PRECIP-FREE TONIGHT. ALOFT...THE HEART OF THE MID/UPPER RIDGE AXIS
WILL SET UP OVER THE CENTRAL PLAINS TONIGHT...AS THE UPSTREAM
TROUGH/JET STREAK START CROSSING THE NORTHERN ROCKIES. AT THE
SURFACE...STEADY SOUTHERLY BREEZES SHOULD HELP HOLD TEMPS UP ABOUT
10 DEGREES WARMER THAN THOSE THIS MORNING...AND HAVE MOST OF THE
CWA IN THE 55-58 RANGE FOR LOWS...WHICH IS VERY SLIGHTLY WARMER
THAN PREVIOUS FORECAST.
TUESDAY IS STILL SHAPING UP TO BE THE WARMEST DAY OF THE
WEEK...WITH PLENTY OF SOUTHERLY WIND TO GO WITH IT. STARTING WITH
STORM CHANCES...HAVE KEPT IT STORM FREE THROUGH THE DAY...AS EVEN
THOUGH DEWPOINTS WILL BE IN THE INCREASE INTO THE 50S IN MOST
AREAS WITH A CORRESPONDING INCREASE IN LOW LEVEL INSTABILITY...MID
LEVEL TEMPS WILL ALSO BE ON THE INCREASE...WITH NAM SOUNDINGS
CONFIRMING A DECENT CAPPING INVERSION. BY LATE AFTERNOON...THE
NAM/GFS/ECMWF ARE IN GENERAL AGREEMENT SETTING UP A 990-994MB LOW
IN FAR WESTERN NEBRASKA...WITH PRESSURE FALLS DURING THE DAY
SETTING UP QUITE A HEALTHY EAST-WEST SURFACE PRESSURE GRADIENT
DURING THE DAY. THIS GRADIENT...IN TANDEM WITH SHOULD BE PLENTY OF
SUN AND MIXING TO AT LEAST THE 800MB LEVEL SHOULD HELP CRANK UP
THE SOUTHERLY WIND. TAKING A CONSENSUS OF 00Z MET/MAV GUIDANCE FOR
SPEEDS...HAVE MOST OF THE CWA CURRENTLY TOPPING OUT IN THE 25-30
MPH RANGE FOR SUSTAINED SPEEDS...WHICH IF IT WERE TO HOLD WOULD
GENERALLY FALL JUST SHORT OF WIND ADVISORY CRITERIA.
HOWEVER...COULD EASILY FORESEE AT LEAST WESTERN PORTIONS OF THE
CWA ENDING UP WITH HIGHER SPEEDS OVER 30 MPH...AND ALTHOUGH WILL
FOREGO ANY HEADLINE ISSUANCE STILL BEING 3 PERIODS OUT...WILL
CONTINUE TO HIGHLIGHT AT LEAST NEAR-ADVISORY SPEEDS IN THE HWO.
CERTAINLY GUSTS TO AROUND 40 MPH SHOULD BE COMMON NO MATTER WHAT
DURING THE AFTERNOON. TEMP-WISE...AGAIN LEANED HEAVILY ON RAW 0Z
NAM NUMBERS...WHICH RESULTED IN LITTLE CHANGE FROM PREVIOUS ACROSS
EASTERN ZONES...BUT ACTUALLY A SLIGHT LOWERING IN WESTERN AREAS.
THIS RESULTS IN MOST AREAS TOPPING OUT BETWEEN 87-90...WHICH IS
STILL AT LEAST A FEW DEGREES ABOVE MET GUIDANCE. IF SURFACE
DEWPOINTS MANAGE TO MIX DOWN FURTHER THAN CURRENTLY THOUGHT...THEN
COULD EASILY SEE PARTS OF THE SOUTHWEST CWA TRY TO MAKE A RUN AT
MID 90S BUT WILL KEEP IT BELOW THIS FOR NOW.
TUESDAY NIGHT...KEPT IT STORM FREE DESPITE THE LEADING EDGE
FORCING FROM THE INCOMING SHORTWAVE/JET STREAK STARTING TO IMPINGE
ON WESTERN PORTIONS OF THE REGION. ALTHOUGH THE LOW LEVEL JET WILL
REALLY RAMP UP OVER THE CWA DURING THE NIGHT...SPEED CONVERGENCE
IS NOT REALLY PRESENT AND MORE IMPORTANTLY...VERY WARM MID LEVEL
TEMPS AS EVIDENCED BY 700MB TEMPS CLIMBING INTO AT LEAST THE
12-14C RANGE SHOULD PROVIDE A VERY STOUT CAP EVEN TO ELEVATED
PARCELS. EVEN WITH THE APPROACH OF A SURFACE-850MB COLD FRONT
AFTER MIDNIGHT ACROSS WESTERN NEB...JUST NOT SEEING THIS CAP
BREAKING WITH LARGE SCALE FORCING STILL LIMITED. TEMP
WISE...SHOULD BE A SEASONABLY MILD NIGHT AND LEFT LOWS PRETTY MUCH
ALONE IN THE LOW-MID 60S.
WEDNESDAY DAYTIME...OPTED TO STAY CONSISTENT WITH PREVIOUS
FORECAST AND LEAVE OUT STORM MENTION...BUT WILL SAY THAT WOULD NOT
BE SURPRISED IF AT LEAST A SLIGHT POP COULD BE ADDED AT SOME
POINT. THE MAIN THING HOLDING BACK A LEGITIMATE DAYTIME STORM THREAT
IS CONTINUED STRONG CAPPING...WITH THE LATEST 06Z NAM FINALLY
FALLING IN LINE WITH THE GFS/ECWMF SOLUTIONS IN KEEPING FAIRLY
TOASTY 700MB TEMPS IN PLACE THROUGH THE DAY...DESPITE THE INVASION
OF A SURFACE COLD FRONT INTO NORTHWEST PARTS OF THE CWA. EVEN THE
LATEST RUN OF THE SREF THUNDER PROBABILITIES HAS BACKED OFF A BIT
ON THE FAIRLY SLIM RISK OF PRE-00Z CONVECTIVE INITIATION. ASSUMING
THAT IT REMAINS STORM-FREE...THE MAIN ISSUE FOR WEDNESDAY IS A
TRICKY HIGH TEMP FORECAST...AS ALTHOUGH THE SOUTHEAST 1/2 OR SO OF
THE CWA SHOULD REMAIN FIRMLY IN THE WARM SECTOR...NORTHWEST ZONES
COULD SEE AT LEAST WEAK COLD AIR ADVECTION/NORTHEAST WIND. OPTED
TO WARM UP MOST AREAS 2-3 DEGREES FROM PREVIOUS FORECAST SIDING
WITH SLOWER INVASION OF COOLER AIR...NOW ADVERTISING A RANGE FROM
NEAR 80 FAR NORTHWEST TO LOW 90S SOUTHEAST.
WEDNESDAY NIGHT...THIS IS CLEARLY THE MOST FAVORED PERIOD FOR
POTENTIALLY...REPEATING POTENTIALLY WIDESPREAD THUNDERSTORM
ACTIVITY...AS MID LEVEL TEMPS SHOULD BE ABLE TO COOL ENOUGH AT
LEAST IN NORTHWEST ZONES TO ALLOW INITIATION. ON THE LARGER
SCALE...LEGITIMATE FORCING FINALLY ARRIVES IN THE FORM OF AN OPEN
MID LEVEL SHORTWAVE AND THE EXIT REGION OF A 300MB JET STREAK
APPROACHING FROM THE CENTRAL ROCKIES. THAT BEING SAID...LATEST
MODEL CONSENSUS IS TO REALLY LIMIT STORM DEVELOPMENT ACROSS
SOUTHEAST ZONES...WHILE MAINLY TARGETING NORTHWEST ZONES WITH
CONVECTION...AND LEAVING CENTRAL PLACES INCLUDING THE TRI CITIES A
BIT IN LIMBO. FOR NOW...OPTED TO KEEP POPS SIMILAR TO PREVIOUS
FORECAST...RANGING FROM LIKELY 60S IN THE NORTHWEST TO NO STORM
MENTION FAR SOUTHEAST...AND A GRADUAL GRADIENT OF SLIGHT CHANCE TO
CHANCE POPS IN BETWEEN. THE POTENTIAL IS CERTAINLY THERE FOR
A WIDESPREAD FLARE UP OF STORMS...AS THE NAM ADVERTISES
CONSIDERABLE CONVERGENCE ACROSS A SHARP 850MB FRONT...WITH A LOW
LEVEL JET POTENTIALLY IN EXCESS OF 60KT BLASTING INTO THIS
BOUNDARY. WITH ELEVATED INSTABILITY POTENTIALLY INTO THE 1000-2000
J/KG RANGE IN THE EVENING...ALONG WITH DEEP LAYER SHEAR ON THE
ORDER OF 50-70KT...A ROUND OF SEVERE STORMS WITH HAIL/WIND IS VERY
POSSIBLE...AGAIN MAINLY FAVORING THE LESS-CAPPED NORTHWEST ZONES.
CERTAINLY PLENTY OF DETAILS TO IRON OUT OVER THE NEXT FEW DAYS
THOUGH.
.LONG TERM...STARTING 12Z THURSDAY. GUIDANCE CONTINUES TO SUGGEST MID
AND UPPER LEVEL JET ENERGY WILL PERSIST OVER THE CENTRAL PLAINS
THROUGH MUCH OF THE LONG TERM FORECAST PERIOD. AT THE SURFACE A
RIDGE HIGH PRESSURE IS EXPECTED TO DOMINATE THE LOW LEVELS
THURSDAY THROUGH MUCH OF FRIDAY...WITH LOW LEVEL RETURN FLOW
MATERIALIZING ACROSS THE AREA LATE FRIDAY ONWARD.
THE OPERATIONAL GFS AND EC BOTH ADVERTISE MID LEVEL PERTURBATIONS
WILL PUSH OVER THE AREA DURING THE DAY THURSDAY...WITH PERHAPS
ENOUGH OMEGA AND MOISTURE FOR PRECIPITATION PRODUCTION ACROSS
NORTHERN PORTIONS OF THE CWA. THE RIGHT-REAR QUADRANT OF A ~70KT MID
LEVEL JET STREAK IS THEN EXPECTED TO PROMOTE ENOUGH OF A DIRECT
THERMAL CIRCULATION FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE
CWA THURSDAY NIGHT INTO FRIDAY MORNING. AN OVERALL LACK IN KINEMATIC
FORCING IS THEN EXPECTED TO BRING DRY CONDITIONS TO THE AREA DURING
THE DAY FRIDAY...WITH THE EMERGENCE OF A ~40KT LOW LEVEL JET
BRINGING ANOTHER POSSIBILITY OF PRECIPITATION TO THE AREA FRIDAY
NIGHT INTO SATURDAY MORNING. ONE MORE ROUND OF NOCTURNAL
PRECIPITATION THEN APPEARS POSSIBLE SATURDAY NIGHT INTO SUNDAY
MORNING AS A STRONGER LOW LEVEL JET INFILTRATES THE AREA.
LOW LEVEL MOISTURE REMAINS LESS THAN IMPRESSIVE THROUGH FRIDAY AS
SURFACE RIDGING REMAINS ENTRENCHED ACROSS THE AREA AND AS A
RESULT...INSTABILITY SUFFERS GREATLY. CONTEMPLATED TAKEN THUNDER OUT
OF THE FORECAST ALTOGETHER THURSDAY AND THURSDAY NIGHT BUT WITH THE
OPERATIONAL GFS AND EC BOTH SUGGESTING MAYBE AROUND 100J/KG DEEP
LAYER MUCAPE VALUES...WENT AHEAD WITH ISOLATED THUNDER MENTION FOR
THAT TIME BEING. LOW LEVEL MOISTURE FLUX INTO THE AREA VIA LOW LEVEL
RETURN FLOW SHOULD ALLOW FOR INCREASING INSTABILITY VALUES HEADING
INTO THE WEEKEND...WITH 1000-2000J/KG DEEP LAYER MUCAPE VALUES BEING
ADVERTISED BY THE OPERATIONAL GFS AND EC.
NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES ARE STILL EXPECTED
THURSDAY AS SURFACE RIDGING REMAINS OVER THE AREA. LOW LEVEL RETURN
FLOW WILL THEN PROMOTE A WARMING TREND...WITH TEMPERATURES CLIMBING
TO LEVELS WELL ABOVE-NORMAL FOR THIS TIME OF YEAR ACROSS OUR SOUTH
ON FRIDAY...AND ACROSS THE ENTIRE CWA SATURDAY ONWARD.
&&
.PREV DISCUSSION... /ISSUED 1151 PM CDT SUN MAY 20 2012/
AVIATION...06Z KGRI TAF. THE WIND WILL BE LIGHT AND VARIABLE THROUGH
THE NIGHT. THERE WILL BE AN INCREASE IN THE SOUTHEASTERLY WIND BY
MID MORNING BUT NOTHING TOO GUSTY. VFR CONDITIONS WILL PREVAIL
THROUGHOUT THE PERIOD. THERE WILL BE FEW TO SCATTERED HIGH CLOUDS
BUT THERE SHOULD BE NO WEATHER RELATED AVIATION CONCERNS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...BRYANT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
550 AM EDT MON MAY 21 2012
.SYNOPSIS...
AN UPPER LOW OVER THE SOUTHEAST COAST WILL OPEN UP AND LIFT
NORTHEAST TODAY AND TONIGHT. A DEEPENING SHORTWAVE WILL SLOW DOWN
AND CUT OFF OVR THE CENTRAL APPALACHIANS DURING THE MIDDLE OF THE
WEEK. PENNSYLVANIA WILL BE ON THE EDGE OF A BUILDING 500 HPA RIDGE
ACROSS THE OHIO VALLEY BY THE END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LOW OVER THE CAROLINA COAST WILL LIFT NORTH ALONG THE E
COAST DURING THE NEXT 24HRS. ASSOCIATED MOIST...EASTERLY LL JET AND
UPPER LVL DIVERGENCE PRECEDING THE UPPER LOW WILL BRING SHOWERS
TO MOST OF CENTRAL PA TODAY. RADAR SHOWS SCT SHOWERS HAVE ALREADY
OVERSPREAD THE LOWER SUSQ VALLEY AS OF 09Z AND LATEST RUC AND 4KM
NAM SUGGEST NORTHERN EDGE OF SHOWERS/DRIZZLE WILL REACH FROM ARND
JST TO IPT BY LATE MORNING.
CLOUD COVER...PRECIP AND EASTERLY FLOW OFF THE ATLANTIC WILL
RESULT IN MUCH COOLER TEMPS TODAY WITH MAXIMUMS ONLY ARND 70F.
BLEND OF OPER AND ENSEMBLE QPF INDICATES LIKELY RAINFALL AMTS
TODAY OF BTWN 0.1 AND 0.2 INCHES.
DOWNSLOPING SE FLOW WILL RESULT IN PARTIAL SUNSHINE AND A
SOMEWHAT WARMER MONDAY OVR WARREN COUNTY...WHERE A LATE DAY
TSRA IS POSSIBLE. OPER GFS/NAM INDICATE CAPE VALUES NR 1000JK-1
ACROSS WARREN CO BY THIS EVENING. FURTHER EAST...A COOLER MORE
STABLE EASTERLY FLOW WILL LIKELY PRECLUDE THUNDER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
SCT SHRA WILL CONTINUE TO FALL OVER CENTRAL PA TONIGHT...AS MOIST
EASTERLY LL JET AND UPPER LVL DIVERGENCE REMAIN OVR THE AREA IN
ADVANCE OF UPPER LOW. A GENERAL DECREASE IN SHOWER ACTIVITY IS
EXPECTED LATE TONIGHT AS UPPER LOW OPENS UP AND LIFTS NE. BIGGER
STORY LATE TONIGHT COULD BE AREAS OF POTENTIALLY DENSE FOG. PLENTY
OF LL MOISTURE AND A NEARLY CALM WIND WILL BE FAVORABLE FOR FOG.
AS E COAST UPPER LOW OPENS UP AND LIFTS INTO THE CANADIAN
MARITIMES...UPSTREAM SHORTWAVE WILL DEEPEN AND CUT OFF OVR THE
TENN VALLEY ON TUESDAY. LG SCALE FORCING AHEAD OF THIS FEATURE
WILL PRODUCE MORE SHRA/TSRA TUESDAY. GEFS/SREF DATA BOTH SUGGEST
BEST CHC OF SHRA/TSRA WILL BE ALONG THE SPINE OF THE APPALACHIANS.
OVERCAST SKIES AND VERY LGT WINDS ALOFT SUGGEST THERE WILL BE VERY
LITTLE THREAT OF SVR WX. BLEND OF GEFS/SREF QPF RANGES FROM 0.2 TO
0.3 INCHES TONIGHT AND TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
RELATIVELY GOOD AGREEMENT AMONG MED RANGE GUIDANCE LATER THIS
WEEK...ALL OF WHICH INDICATES UPPER LOW SLOWLY LIFTING NORTH ALONG
THE CENTRAL APPALACHIANS. THIS SCENARIO SUPPORTS THE CHC OF
DIURNALLY ENHANCED SHRA/TSRA WED-THU AND POSSIBLY EVEN FRIDAY. NEARLY
ALL MDL DATA TRACKS TS ALBERTO WELL EAST OFF THE MID ATLANTIC
COAST TUE NIGHT WITH NO DIRECT IMPACT ON PA.
TEMPS THIS WEEK LOOK TO BE ABOVE NORMAL...MAINLY DUE TO WARM
OVERNIGHT LOWS. DEEP SOUTHERLY FLOW AHEAD OF UPPER LOW WILL
TRANSPORT ABOVE NORMAL MOISTURE NORTH ALONG THE E COAST...RESULTING
IN THE WARM NIGHTS.
EVEN WARMER WX APPEARS VERY LIKELY BY NEXT WEEKEND WHEN ALL MDL
DATA INDICATES A BUILDING UPPER LVL RIDGE OVER THE OHIO VALLEY.
HOWEVER...PA MAY BE ON PERIPHERY OF THIS FEATURE...PLACING AT
LEAST NORTHERN PA IN RING OF FIRE WITH CHC OF PM CONVECTION.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE NOW MOVING OFF TO THE NORTHEAST. AN INCREASING MOIST
EAST TO SOUTHEAST FLOW HAS ALREADY BEGUN TO PUSH ATLANTIC MOISTURE
INTO CENTRAL PA...RESULTING IN MVFR CIGS ALREADY WORKING INTO THE
LOWER SUSQ. THESE LOWER CLOUDS WILL CONTINUE TO GRADUALLY SPREAD
NW THROUGH THE MORNING HOURS...EVENTUALLY ENCOMPASSING ALL TAF
SITES EXCEPT KBFD...AND LOWERING CIGS IN THE LOWER SUSQ /KMDT-
KLNS/ TO IFR. SHOWERS WILL ALSO INCREASE FROM THE SE DURING THE
DAY TODAY.
CIGS MAY RECOVER TO MVFR THIS AFTERNOON...WITH A TSTM EMBEDDED IN
THE NUMEROUS SHOWERS. BUT CIGS DROP AGAIN AND WILL BECOME IFR
AREAWIDE OVERNIGHT AS AS AN UPPER LEVEL TROF APPROACHES FROM THE
GREAT LAKES.
OUTLOOK...
MON NIGHT-WED...WIDESPREAD MVFR/IFR CIGS AND VSBYS LIKELY IN
SHOWERS AND SCT TSRA.
THU...PRIMARILY VFR. SCT SHRA/TSTM POSS MAINLY SE.
FRI...PRIMARILY VFR. ISOLD SHRA/TSTM POSS MAINLY SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...JUNG/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
221 AM EDT MON MAY 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL PUSH WELL OFF THE COASTAL NEW ENGLAND WATERS
TONIGHT. AN INCREASING MOIST EAST TO SOUTHEAST FLOW WILL PUSH
ATLANTIC MOISTURE INTO CENTRAL PENNSYLVANIA EARLY MONDAY MORNING...AS
AN UPPER LEVEL TROF MOVES TO THE CENTRAL GREAT LAKES ON MONDAY.
THIS WILL BRING AN INCREASING CHANCE OF SHOWERS TO ALL OF CENTRAL
PA ON MONDAY. AN UPPER LEVEL LOW OVER THE SOUTHEAST WILL SLOWLY
TRACK NORTHEASTWARD THROUGH MID WEEK...KEEPING UNSETTLED WEATHER
ALONG THE EASTERN SEABOARD...AND A DAILY CHANCE OF SHOWERS AND
THUNDERSTORMS OVER CENTRAL PENNSYLVANIA. PENNSYLVANIA WILL BE ON
THE EDGE OF A BUILDING A LARGE UPPER HIGH ACROSS THE TENNESSEE
RIVER VALLEY AND SOUTHEASTERN STATES BY THE END OF THIS WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
STRATUS AND SCT SHRA OVERSPREADING SOUTHEAST PA EARLY THIS
MORNING...AS UPPER LOW AND ATTENDANT MOIST...EASTERLY LL JET
LIFTS UP THE E COAST. LATEST RUC AND 4KM NAM SUGGEST NORTHERN EDGE
OF SHOWERS/DRIZZLE WILL REACH FROM ARND BEDFORD TO SELINSGROVE BY
DAWN. INCREASING DWPTS AND CLOUD COVER WILL RESULT IN A MUCH
MILDER NIGHT THAN WE/VE SEEN RECENTLY WITH MIN TEMPS RANGING FROM
THE M50S ACROSS THE ALLEGHENY MTNS...TO THE L60S ACROSS THE LOWER
SUSQ VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
NO CHANGES TO THE THINKING ON MONDAY AS UPPER LOW OVER THE
SOUTHEAST CONUS WILL LIFT NORTH ALONG THE E COAST. ASSOCIATED
MOIST...EASTERLY LL JET AND UPPER LVL DIVERGENCE PRECEDING THE
UPPER LOW WILL LIKELY BRING SCT SHOWERS TO CENTRAL PA BEGINNING
LATE TONIGHT ACROSS THE SOUTHEAST ZONES AND OVERSPREADING THE
REST OF CENTRAL PA DURING MONDAY. CLOUD COVER...PRECIP AND
EASTERLY FLOW OFF THE ATLANTIC WILL RESULT IN A MUCH COOLER
MONDAY WITH MAX TEMPS ONLY ARND 70F. GEFS DATA SHOWING HIGHEST
PWATS ACROSS SOUTHEAST PA...WHERE THE BEST CHC OF MEASURABLE
RAINFALL IS EXPECTED SUN NITE/MONDAY.
DOWNSLOPING SE FLOW WILL RESULT IN PARTIAL SUNSHINE AND A
SOMEWHAT WARMER MONDAY OVR WARREN COUNTY...WHERE A LATE DAY
TSRA IS POSSIBLE. CAPE VALUES IN THE 600 TO 800JK-1 RANGE
ACROSS WARREN CO MON EVENING. FURTHER EAST...A COOLER MORE
STABLE EASTERLY FLOW SHOULD PRECLUDE THUNDER.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
NOT A LOT OF CHANGE FROM THE FCST PACKAGE YESTERDAY.
STILL LOOKS LIKE NORTHERN SYSTEM OFF THE COAST WILL PIVOT AROUND
ALBERTO AND MOVE WESTWARD...BRINGING SHOWERS TO THE AREA ON TUE.
MAIN CHC WILL BE MONDAY INTO TUE.
DID UP TEMPS SOME ON TUE...ALSO SOME CHC OF A THUNDERSTORM WITH
THE WARMER TEMPS.
SHOWERS COULD LINGER INTO WED...ESPECIALLY ACROSS THE SE WITH
THE FRONT.
TRIED TO GO WITH THE MID SHIFT FCST AND HAVE SOME PERIODS OF
DRY WEATHER. HARD TO FIND A LOT OF DRY PERIODS...AS REMAINS OF
CUTOFF COULD KEEP A FEW SHOWERS ACROSS EASTERN AREAS...WHERE
FAR NW AREAS COULD SEE SOME FROM THE COLD FRONT LATE IN THE
WEEK.
WENT WITH A DRY FCST FOR SUNDAY...IT WILL BE CLOSE...HARD TO
SEE THE EAST...WEST COLD FRONT DROPPING TOO FAR SOUTH.
TEMPS WILL BE WARM THROUGHOUT THE PERIOD...ABOVE NORMAL.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE NOW MOVING OFF TO THE NORTHEAST. AN INCREASING MOIST
EAST TO SOUTHEAST FLOW HAS ALREADY BEGUN TO PUSH ATLANTIC MOISTURE
INTO CENTRAL PA...RESULTING IN MVFR CIGS ALREADY WORKING INTO THE
LOWER SUSQ. THESE LOWER CLOUDS WILL CONTINUE TO GRADUALLY SPREAD
NW THROUGH THE MORNING HOURS...EVENTUALLY ENCOMPASSING ALL TAF
SITES EXCEPT KBFD...AND LOWERING CIGS IN THE LOWER SUSQ /KMDT-
KLNS/ TO IFR. SHOWERS WILL ALSO INCREASE FROM THE SE DURING THE
DAY TODAY.
CIGS MAY RECOVER TO MVFR THIS AFTERNOON...WITH A TSTM EMBEDDED IN
THE NUMEROUS SHOWERS. BUT CIGS DROP AGAIN AND WILL BECOME IFR
AREAWIDE OVERNIGHT AS AS AN UPPER LEVEL TROF APPROACHES FROM THE
GREAT LAKES.
OUTLOOK...
MON NIGHT-WED...WIDESPREAD MVFR/IFR CIGS AND VSBYS LIKELY IN
SHOWERS AND SCT TSRA.
THU...PRIMARILY VFR. SCT SHRA/TSTM POSS MAINLY SE.
FRI...PRIMARILY VFR. ISOLD SHRA/TSTM POSS MAINLY SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...JUNG/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
145 AM EDT MON MAY 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL PUSH WELL OFF THE COASTAL NEW ENGLAND WATERS
TONIGHT. AN INCREASING MOIST EAST TO SOUTHEAST FLOW WILL PUSH
ATLANTIC MOISTURE INTO CENTRAL PENNSYLVANIA EARLY MONDAY MORNING...AS
AN UPPER LEVEL TROF MOVES TO THE CENTRAL GREAT LAKES ON MONDAY.
THIS WILL BRING AN INCREASING CHANCE OF SHOWERS TO ALL OF CENTRAL
PA ON MONDAY. AN UPPER LEVEL LOW OVER THE SOUTHEAST WILL SLOWLY
TRACK NORTHEASTWARD THROUGH MID WEEK...KEEPING UNSETTLED WEATHER
ALONG THE EASTERN SEABOARD...AND A DAILY CHANCE OF SHOWERS AND
THUNDERSTORMS OVER CENTRAL PENNSYLVANIA. PENNSYLVANIA WILL BE ON
THE EDGE OF A BUILDING A LARGE UPPER HIGH ACROSS THE TENNESSEE
RIVER VALLEY AND SOUTHEASTERN STATES BY THE END OF THIS WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
STRATUS AND SCT SHRA OVERSPREADING SOUTHEAST PA EARLY THIS
MORNING...AS UPPER LOW AND ATTENDANT MOIST...EASTERLY LL JET
LIFTS UP THE E COAST. LATEST RUC AND 4KM NAM SUGGEST NORTHERN EDGE
OF SHOWERS/DRIZZLE WILL REACH FROM ARND BEDFORD TO SELINSGROVE BY
DAWN. INCREASING DWPTS AND CLOUD COVER WILL RESULT IN A MUCH
MILDER NIGHT THAN WE/VE SEEN RECENTLY WITH MIN TEMPS RANGING FROM
THE M50S ACROSS THE ALLEGHENY MTNS...TO THE L60S ACROSS THE LOWER
SUSQ VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
NO CHANGES TO THE THINKING ON MONDAY AS UPPER LOW OVER THE
SOUTHEAST CONUS WILL LIFT NORTH ALONG THE E COAST. ASSOCIATED
MOIST...EASTERLY LL JET AND UPPER LVL DIVERGENCE PRECEDING THE
UPPER LOW WILL LIKELY BRING SCT SHOWERS TO CENTRAL PA BEGINNING
LATE TONIGHT ACROSS THE SOUTHEAST ZONES AND OVERSPREADING THE
REST OF CENTRAL PA DURING MONDAY. CLOUD COVER...PRECIP AND
EASTERLY FLOW OFF THE ATLANTIC WILL RESULT IN A MUCH COOLER
MONDAY WITH MAX TEMPS ONLY ARND 70F. GEFS DATA SHOWING HIGHEST
PWATS ACROSS SOUTHEAST PA...WHERE THE BEST CHC OF MEASURABLE
RAINFALL IS EXPECTED SUN NITE/MONDAY.
DOWNSLOPING SE FLOW WILL RESULT IN PARTIAL SUNSHINE AND A
SOMEWHAT WARMER MONDAY OVR WARREN COUNTY...WHERE A LATE DAY
TSRA IS POSSIBLE. CAPE VALUES IN THE 600 TO 800JK-1 RANGE
ACROSS WARREN CO MON EVENING. FURTHER EAST...A COOLER MORE
STABLE EASTERLY FLOW SHOULD PRECLUDE THUNDER.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
NOT A LOT OF CHANGE FROM THE FCST PACKAGE YESTERDAY.
STILL LOOKS LIKE NORTHERN SYSTEM OFF THE COAST WILL PIVOT AROUND
ALBERTO AND MOVE WESTWARD...BRINGING SHOWERS TO THE AREA ON TUE.
MAIN CHC WILL BE MONDAY INTO TUE.
DID UP TEMPS SOME ON TUE...ALSO SOME CHC OF A THUNDERSTORM WITH
THE WARMER TEMPS.
SHOWERS COULD LINGER INTO WED...ESPECIALLY ACROSS THE SE WITH
THE FRONT.
TRIED TO GO WITH THE MID SHIFT FCST AND HAVE SOME PERIODS OF
DRY WEATHER. HARD TO FIND A LOT OF DRY PERIODS...AS REMAINS OF
CUTOFF COULD KEEP A FEW SHOWERS ACROSS EASTERN AREAS...WHERE
FAR NW AREAS COULD SEE SOME FROM THE COLD FRONT LATE IN THE
WEEK.
WENT WITH A DRY FCST FOR SUNDAY...IT WILL BE CLOSE...HARD TO
SEE THE EAST...WEST COLD FRONT DROPPING TOO FAR SOUTH.
TEMPS WILL BE WARM THROUGHOUT THE PERIOD...ABOVE NORMAL.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS PREVAIL ACROSS CENTRAL PENNSYLVANIA. MID CLOUDS
STARTING TO STREAM INTO SOUTHERN TIER COUNTIES AND MAKING THEIR
WAY INTO CENTRAL PA...WITH CIGS 050 TO 100.
EASTERLY FLOW WILL PERSIST OVERNIGHT...AND BRING WITH IT A GRADUAL
INCREASE CLOUDS SPREADING IN FROM THE SOUTHWEST. BY 06Z MVFR CIGS
EXPECTED OVER KMDT AND KLNS...AND BY MONDAY MORNING /12Z/ EXPECT
MVFR CIGS TO OVERSPREAD MUCH OF SOUTHEAST PENNSYLVANIA INTO THE
LAURELS. MOISTURE WILL CONTINUE TO INCREASE ACROSS THE REGION ON
SOUTHEAST LOW LEVEL FLOW...AS DEEP LOW LIFTS INTO THE REGION. MVFR
TO IFR CIGS EXPECTED TO OVERSPREAD MOST OF CENTRAL PENNSYLVANIA BY
14-16Z...WITH INCREASING SHOWERS. EXCEPTION MAY BE FAR NW /KBFD/
WHERE VFR CONDITIONS MAY LINGER INTO LATER AFTERNOON.
OUTLOOK...
MON NIGHT-WED...WIDESPREAD MVFR/IFR CIGS AND VSBYS LIKELY IN
SHOWERS AND SCT TSRA.
THU...PRIMARILY VFR. SCT SHRA/TSTM POSS MAINLY SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...JUNG/DEVOIR
AREA FORECAST DISCUSSION
NWS NEW YORK NY
931 AM EDT MON MAY 21 2012
.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH
TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY...
FOLLOWED BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS
THEREAFTER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW CLOUDS AND FOG DEVELOPED ACROSS THE COASTAL SECTIONS...WITH
PATCHY DRIZZLE...EARLY THIS MORNING. VISIBILITIES HAVE LOWERED
QUICKLY. UPDATED TO INCLUDE THE FOG AND DRIZZLE THIS MORNING.
WILL CONFINE SHOWERS TO NYC AND AREAS JUST TO THE WEST OF THE
CITY FOR SEVERAL HOURS THIS MORNING...THEN SHOWERS INCREASE IN
COVERAGE SLOWLY FROM SW TO NE. THIS REFLECTS WELL IN THE HRRR AND
RAP IN THE NEAR TERM. COULD TAKE SOMETIME FOR INTERIOR ZONES TO
SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL LIKELY COVERAGE IS
WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA.
OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES
SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150
TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT
EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT
WILL RESULT IN SHOWERS TODAY...POSSIBLE THUNDER...AND PLENTY OF
CLOUDS.
MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND
FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. 00Z NAM
SOLUTION WAS DISCARDED FOR THIS FORECAST. 00Z NAM FORECASTS A
DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN
ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY.
QUICK LOOK AT 06Z NAM...THE LOW HAS SHIFTED EAST CLOSER TO OTHER
MODEL SOLUTIONS.
IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE
THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL
HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK
FORECASTS AND DISCUSSIONS REGARDING ALBERTO.
ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE
FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE
TONIGHT/EARLY TUESDAY.
BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK
TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN
COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES
NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY
HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE
JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR.
BACKING UP A BIT...IF 00Z NAM PROVES TO BE CORRECT...HEAVIER RAIN
WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY
TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME.
TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE
FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD
REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR
THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES
THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY
STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE
ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD
FRONT LATE FRIDAY.
T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT
FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE
LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST
INFORMATION ON ALBERTO.
WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER
THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY
LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG
DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE
OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD
FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF
INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS
THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL
CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT
EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO
LOWER 80S DESPITE THE CLOUDS/MORNING FOG.
WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE
MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF
THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS
TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK
SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS
INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER.
THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD.
NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE
REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD
THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL
OFFSHORE. MOST TERMINALS IFR RANGE WITH SOME IN LIFR WITH RESPECT
TO CIGS AND MORE VARIABLE WITH VSBYS. LOW CHANCE OF ANY
IMPROVEMENT. EXPECTING IFR AT BEST THIS AFTERNOON. SHOWERS ARE
PERIODIC TODAY BUT TRIED TO INDICATE A LULL BY INCREASING VSBYS IN
THE AFTERNOON. CONDITIONS EXPECTED DROP BACK DOWN TO AT LEAST IFR
AND LOWER IN SPOTS WITH RAIN/FOG TONIGHT.
VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM FORECAST.
FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY.
NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT....TURNING MORE
SOUTHEASTERLY ON TUESDAY.
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)
KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR VARYING CEILINGS AND
VSBYS IN HEAVIER SHOWERS AND POSSIBLE THUNDER.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR VARYING CEILINGS AND
VSBYS IN HEAVIER SHOWERS AND THUNDER.
KEWR FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR VARYING CEILINGS AND
VSBYS IN HEAVIER SHOWERS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
.OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
.TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM
WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT.
.THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN
SHOWERS ON FRIDAY.
&&
.MARINE...
UPDATED FOR WEATHER THIS MORNING TO INCLUDE FOG AND DRIZZLE ACROSS
THE FORECAST WATERS.
SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN
WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND
SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE
HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE.
A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER
THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN
TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON
TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA.
&&
.HYDROLOGY...
OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH
ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY.
SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD
RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY
HEAVIER SHOWERS.
AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR
LOCATION CONTINUE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MPS/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...MPS
AVIATION...IRD
MARINE...MPS/PW
HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
851 AM EDT MON MAY 21 2012
.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH
TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY...
FOLLOWED BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS
THEREAFTER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW CLOUDS AND FOG DEVELOPED ACROSS THE COASTAL SECTIONS...WITH
PATCHY DRIZZLE...EARLY THIS MORNING. VISIBILITIES HAVE LOWERED
QUICKLY. UPDATED TO INCLUDE THE FOG AND DRIZZLE THIS MORNING.
WILL CONFINE SHOWERS TO NYC AND AREAS JUST TO THE WEST OF THE
CITY FOR SEVERAL HOURS THIS MORNING...THEN SHOWERS INCREASE IN
COVERAGE SLOWLY FROM SW TO NE. THIS REFLECTS WELL IN THE HRRR AND
RAP IN THE NEAR TERM. COULD TAKE SOMETIME FOR INTERIOR ZONES TO
SEE PRECIP AS ENOUGH DRY AIR REMAINS. FEEL LIKELY COVERAGE IS
WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA.
OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES
SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150
TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT
EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT
WILL RESULT IN SHOWERS TODAY...POSSIBLE THUNDER...AND PLENTY OF
CLOUDS.
MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND
FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. 00Z NAM
SOLUTION WAS DISCARDED FOR THIS FORECAST. 00Z NAM FORECASTS A
DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN
ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY.
QUICK LOOK AT 06Z NAM...THE LOW HAS SHIFTED EAST CLOSER TO OTHER
MODEL SOLUTIONS.
IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE
THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL
HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK
FORECASTS AND DISCUSSIONS REGARDING ALBERTO.
ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE
FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE
TONIGHT/EARLY TUESDAY.
BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK
TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN
COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES
NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY
HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE
JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR.
BACKING UP A BIT...IF 00Z NAM PROVES TO BE CORRECT...HEAVIER RAIN
WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY
TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME.
TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE
FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD
REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR
THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES
THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY
STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE
ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD
FRONT LATE FRIDAY.
T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT
FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE
LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST
INFORMATION ON ALBERTO.
WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER
THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY
LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG
DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE
OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD
FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF
INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS
THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL
CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT
EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO
LOWER 80S DESPITE THE CLOUDS/MORNING FOG.
WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE
MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF
THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS
TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK
SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS
INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER.
THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD.
NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE
REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD
THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL
OFFSHORE. MOST TERMINALS IFR RANGE WITH SOME IN LIFR WITH RESPECT
TO CIGS AND MORE VARIABLE WITH VSBYS. LOW CHANCE OF ANY
IMPROVEMENT. EXPECTING IFR AT BEST THIS AFTERNOON. SHOWERS ARE
PERIODIC TODAY BUT TRIED TO INDICATE A LULL BY INCREASING VSBYS IN
THE AFTERNOON. CONDITIONS EXPECTED DROP BACK DOWN TO AT LEAST IFR
AND LOWER IN SPOTS WITH RAIN/FOG TONIGHT.
VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM FORECAST.
FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY.
NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT....TURNING MORE
SOUTHEASTERLY ON TUESDAY.
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)
KJFK FCSTER COMMENTS: A BRIEF THUNDERSTORM POSSIBLE BEFORE 13Z.
AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD
OCCASIONALLY DROP TO IFR.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. LIFR COULD LAST
LONGER THAN FORECAST.
KEWR FCSTER COMMENTS: A BRIEF THUNDERSTORM POSSIBLE BEFORE 13Z.
AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD
OCCASIONALLY DROP TO IFR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. LIFR CIGS COULD
LAST LONGER THAN FORECAST.
.OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
.TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM
WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT.
.THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN
SHOWERS ON FRIDAY.
&&
.MARINE...
UPDATED FOR WEATHER THIS MORNING TO INCLUDE FOG AND DRIZZLE ACROSS
THE FORECAST WATERS.
SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN
WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND
SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE
HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE.
A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER
THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN
TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON
TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA.
&&
.HYDROLOGY...
OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH
ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY.
SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD
RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY
HEAVIER SHOWERS.
AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR
LOCATION CONTINUE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ350-353-355.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
759 AM EDT MON MAY 21 2012
.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH
TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY...
FOLLOWED BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS
THEREAFTER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WILL CONFINE SHOWERS TO NYC AND AREAS JUST TO THE WEST OF THE CITY
FOR SEVERAL HOURS THIS MORNING...THEN SHOWERS INCREASE IN COVERAGE
SLOWLY FROM SW TO NE. THIS REFLECTS WELL IN THE HRRR AND RAP IN
THE NEAR TERM. COULD TAKE SOMETIME FOR INTERIOR ZONES TO SEE
PRECIP AS ENOUGH DRY AIR REMAINS. FEEL LIKELY COVERAGE IS
WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA.
OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES
SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150
TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT
EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT
WILL RESULT IN SHOWERS TODAY...POSSIBLE THUNDER...AND PLENTY OF
CLOUDS.
MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND
FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. 00Z NAM
SOLUTION WAS DISCARDED FOR THIS FORECAST. 00Z NAM FORECASTS A
DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN
ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY.
QUICK LOOK AT 06Z NAM...THE LOW HAS SHIFTED EAST CLOSER TO OTHER
MODEL SOLUTIONS.
IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE
THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL
HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK
FORECASTS AND DISCUSSIONS REGARDING ALBERTO.
ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE
FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE
TONIGHT/EARLY TUESDAY.
BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK
TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN
COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES
NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY
HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE
JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR.
BACKING UP A BIT...IF 00Z NAM PROVES TO BE CORRECT...HEAVIER RAIN
WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY
TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME.
TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE
FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD
REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR
THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES
THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY
STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE
ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD
FRONT LATE FRIDAY.
T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT
FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE
LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST
INFORMATION ON ALBERTO.
WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER
THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY
LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG
DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE
OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD
FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF
INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS
THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL
CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT
EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO
LOWER 80S DESPITE THE CLOUDS/MORNING FOG.
WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE
MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF
THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS
TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK
SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS
INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER.
THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD.
NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE
REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD
THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL
OFFSHORE. MOST TERMINALS IFR RANGE WITH SOME IN LIFR WITH RESPECT
TO CIGS AND MORE VARIABLE WITH VSBYS. LOW CHANCE OF ANY
IMPROVEMENT. EXPECTING IFR AT BEST THIS AFTERNOON. SHOWERS ARE
PERIODIC TODAY BUT TRIED TO INDICATE A LULL BY INCREASING VSBYS IN
THE AFTERNOON. CONDITIONS EXPECTED DROP BACK DOWN TO AT LEAST IFR
AND LOWER IN SPOTS WITH RAIN/FOG TONIGHT.
VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM FORECAST.
FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR TODAY.
NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT....TURNING MORE
SOUTHEASTERLY ON TUESDAY.
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)
KJFK FCSTER COMMENTS: A BRIEF THUNDERSTORM POSSIBLE BEFORE 13Z.
AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD
OCCASIONALLY DROP TO IFR.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. LIFR COULD LAST
LONGER THAN FORECAST.
KEWR FCSTER COMMENTS: A BRIEF THUNDERSTORM POSSIBLE BEFORE 13Z.
AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN SHOWERS COULD
OCCASIONALLY DROP TO IFR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KHPN FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR. LIFR CIGS COULD
LAST LONGER THAN FORECAST.
.OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY...
.TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM
WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT.
.THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN
SHOWERS ON FRIDAY.
&&
.MARINE...
SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN
WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND
SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE
HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE.
A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER
THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN
TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON
TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA.
&&
.HYDROLOGY...
OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH
ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY.
SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD
RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY
HEAVIER SHOWERS.
AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR
LOCATION CONTINUE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MPS/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...MPS
AVIATION...JM
MARINE...MPS/PW
HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
714 AM EDT MON MAY 21 2012
.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS WILL IMPACT THE AREA THROUGH
TUESDAY. A COLD FRONT MOVES THROUGH THE REGION ON WEDNESDAY...
FOLLOWED BY ANOTHER COLD FRONT ON SATURDAY. HIGH PRESSURE RETURNS
THEREAFTER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WILL CONFINE SHOWERS TO NYC AND AREAS JUST TO THE WEST OF THE CITY
FOR SEVERAL HOURS THIS MORNING...THEN SHOWERS INCREASE IN COVERAGE
SLOWLY FROM SW TO NE. THIS REFLECTS WELL IN THE HRRR AND RAP IN
THE NEAR TERM. COULD TAKE SOMETIME FOR INTERIOR ZONES TO SEE
PRECIP AS ENOUGH DRY AIR REMAINS. FEEL LIKELY COVERAGE IS
WARRANTED BY AFTERNOON ACROSS MUCH OF THE AREA.
OVERALL...PERSISTENT EASTERLY FLOW PREVAILS AS ATMOSPHERE BECOMES
SATURATED. OPERATIONAL MODELS STILL SHOW PRECIPITABLE WATERS OF 150
TO 175 PERCENT ABOVE NORMAL AS THE DAY PROGRESSES. WEAK LIFT
EMBEDDED IN THE MID LEVELS...ALONG WITH INCREASING ISENTROPIC LIFT
WILL RESULT IN SHOWERS TODAY...POSSIBLE THUNDER...AND PLENTY OF
CLOUDS.
MOIST MARINE AIR WILL KEEP TEMPS IN THE 60S...WITH A MOS BLEND
FOLLOWED. LEANED TOWARD COOLER MET MOS WHERE APPROPRIATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MODELS STILL DIFFER THIS TIME FRAME ON SUBTLE FEATURES. 00Z NAM
SOLUTION WAS DISCARDED FOR THIS FORECAST. 00Z NAM FORECASTS A
DEEPER MID LEVEL LOW...AND TRACKS THE SFC LOW FROM THE WESTERN
ATLANTIC TO JUST EAST OF MONTAUK POINT LATE TONIGHT/EARLY TUESDAY.
QUICK LOOK AT 06Z NAM...THE LOW HAS SHIFTED EAST CLOSER TO OTHER
MODEL SOLUTIONS.
IT IS IMPORTANT TO NOTE THAT THIS WAVE IS NOT ALBERTO. PLEASE SEE
THE LATEST ADVISORIES REGARDING ALBERTO FROM THE NATIONAL
HURRICANE CENTER. REFER TO NHC FOR THE LATEST ADVISORIES...TRACK
FORECASTS AND DISCUSSIONS REGARDING ALBERTO.
ANYWAY...LEANED TOWARD A SREF/ECMWF SOLUTIONS WITH REGARD TO THE
FORECAST WITH A SLIGHTLY WEAKER AND FURTHER EAST LOW FOR LATE
TONIGHT/EARLY TUESDAY.
BY TUESDAY...THIS WAVE MOVES TO THE NORTHEAST AS A GENERAL WEAK
TROUGH APPROACHES FROM THE WEST. LIKELY POPS EARLY TONIGHT...THEN
COVERAGE BECAUSE MORE SCATTERED IN NATURE AS MID LEVEL FORCING MOVES
NORTHEAST. WILL CAP POPS IN THE CHANCE RANGE TUESDAY...WITH SLIGHTLY
HIGHER POPS OVER WESTERN SECTIONS CLOSER TO THE TROUGH. COULD BE
JUST ENOUGH INSTABILITY ALOFT FOR THUNDER...MAINLY NW INTERIOR.
BACKING UP A BIT...IF 00Z NAM PROVES TO BE CORRECT...HEAVIER RAIN
WILL MOVE ACROSS EASTERN HALF OF THE CWA LATE TONIGHT/EARLY
TUESDAY...BUT AGAIN THIS SOLUTION HAS BEEN DISCARDED AT THIS TIME.
TEMPERATURES DO NOT FALL MUCH TONIGHT DUE TO CLOUDS AND ONSHORE
FLOW. IF ANY SUN BREAKS OUT TUESDAY...ESPECIALLY WEST...TEMPS COULD
REBOUND NICELY...AND FORECAST IS UNDERDONE. THINKING AROUND 70 NEAR
THE COAST...AND MIDDLE TO UPPER 70S WEST FOR HIGHS TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
MODELS IN DECENT AGREEMENT WITH LONG-TERM OUTLOOK. COLD FRONT MOVES
THROUGH THE REGION WEDNESDAY AFTERNOON...THEN BECOMES NEARLY
STATIONARY EAST OF THE AREA. SEVERAL UPPER LEVEL DISTURBANCES MOVE
ACROSS THE REGION THURSDAY THROUGH FRIDAY...FOLLOWED BY ANOTHER COLD
FRONT LATE FRIDAY.
T.S. ALBERTO IS NOT EXPECTED DIRECTLY IMPACT ON THE REGION...EXCEPT
FOR LONG PERIOD SWELLS INCREASING SURF AT AREA BEACHES. REFER TO THE
LATEST FORECASTS FROM THE NATIONAL HURRICANE CENTER FOR THE LATEST
INFORMATION ON ALBERTO.
WITH PERSISTENT ONSHORE FLOW...WARM AND HUMID AIRMASS REMAINS OVER
THE AREA TUESDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT. ANY
LINGERING SHOWERS TAPER OFF IN THE EVENING...THEN AREAS OF FOG
DEVELOP AFTER MIDNIGHT...WITH LOCALLY DENSE FOG POSSIBLE IN THE
OUTLYING AREAS. FOG SHOULD BURN OFF THROUGH WEDNESDAY MORNING. COLD
FRONT THEN MOVES ACROSS THE AREA THROUGHOUT THE DAY. MODEL QPF
INDICATING BEST CHANCES FOR PRECIP WILL BE OVER WESTERN ZONES...AS
THE FRONT SEEMS TO WASH OUT AS IT MOVES THROUGH THE REGION. WILL
CARRY HIGHEST POPS OVER WESTERN ZONES...WITH LOW CHANCE POPS OUT
EAST IN THE AFTERNOON. HIGHS WEDNESDAY TOP OFF IN THE UPPER 70S TO
LOWER 80S DESPITE THE CLOUDS/MORNING FOG.
WEDNESDAY NIGHT...A CUTOFF H5 LOW BECOMES NEARLY STATIONARY OVER THE
MID-ATLANTIC AREA AND WILL GRADUALLY TRACK NORTH THROUGH THE END OF
THE WEEK. THAT LOW FINALLY DEPARTS FRIDAY NIGHT. DURING THIS
TIME...ISOLATED TO SCATTERED SHOWERS WILL DEVELOP AS SEVERAL WEAK
SHORTWAVES SPIN OFF THAT LOW. ONSHORE FLOW WILL USHER A MILD AIRMASS
INTO THE REGION...KEEPING TEMPS IN THE 70S DESPITE CLOUD COVER.
THESE TEMPS WILL BE ABOVE NORMAL THROUGH THE PERIOD.
NEXT COLD FRONT APPROACHES ON SATURDAY AND WILL MOVE THROUGH THE
REGION SATURDAY NIGHT. HIGH PRES RETURNS ON SUNDAY.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
WEAK LOW PRESSURE DRIFTS NORTHWARD ALONG THE EASTERN SEABOARD
THROUGH TODAY. A LARGER LOW APPROACHES BY TONIGHT BUT STAYS WELL
OFFSHORE. CIGS OF MVFR TO IFR WILL TREND MORE IFR THIS MORNING
AS SHOWER COVERAGE INCREASES. LOOKING FOR THIS TO STAY WITH A
CHANCE OF IMPROVEMENT TO LOW END MVFR...1-2KFT IN THE AFTERNOON
FOR SOME TERMINALS AWAY FROM THE COAST BUT THINK THIS IS QUITE LOW
AT THE MOMENT. THEREFORE IFR CONTINUES IN THE TAFS WITH PERIODIC
SHOWERS TODAY. VSBYS WITHIN SHOWERS COULD VARY BY A FEW MILES FROM
FORECAST. FORECAST HAS VSBYS LOWERING TO MVFR WITH THE SHOWERS FOR
TODAY.
NE-E WINDS IN THE TAF PERIOD NEAR OR BELOW 10 KT.
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)
KJFK FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KLGA FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
KEWR FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN
FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN
SHOWERS COULD OCCASIONALLY DROP TO IFR.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN
FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN
SHOWERS COULD OCCASIONALLY DROP TO IFR.
KHPN FCSTER COMMENTS: IFR CIGS COULD ARRIVE 1-2 HRS LATER THAN
FORECAST. AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS. VSBYS IN
SHOWERS COULD OCCASIONALLY DROP TO IFR.
KISP FCSTER COMMENTS: AMENDMENTS POSSIBLE FOR TIMING OF SHOWERS.
VSBYS IN SHOWERS COULD OCCASIONALLY DROP TO IFR.
.OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY...
.TONIGHT...MVFR OR IFR IN RAIN/FOG. LOWER CONDITIONS POSSIBLE.
.TUESDAY-WEDNESDAY...MVFR WITH IFR POSSIBLE. ISOLATED THUNDERSTORM
WEST OF THE HUDSON TUESDAY AFTERNOON. FOG POSSIBLE TUESDAY NIGHT.
.THURSDAY AND FRIDAY...MAINLY VFR...BUT MVFR OR IFR POSSIBLE IN
SHOWERS ON FRIDAY.
&&
.MARINE...
SMALL CRAFT ADVISORY REMAINS UP FOR SEAS ACROSS THE OCEAN
WATERS...DUE TO THE COMBINATION OF A PERSISTENT EASTERLY FETCH AND
SWELL. THESE HIGHER SEAS CONTINUE THROUGH TUESDAY. FOR THE
HARBORS/BAYS AND SOUND...SUB SCA CONDITIONS CONTINUE.
A PERSISTENT ONSHORE FLOW SHOULD MAINTAIN SEAS AT SCA LEVELS OVER
THE COASTAL OCEAN WATERS THROUGH WEDNESDAY...BUT SEAS SHOULD BEGIN
TO SUBSIDE WEDNESDAY NIGHT AS SWELLS DEPART. LIGHT SOUTHERLY FLOW ON
TAP INTO NEXT WEEKEND WILL KEEP CONDS BELOW SCA CRITERIA.
&&
.HYDROLOGY...
OVERALL...EXPECT ABOUT A HALF AN INCH TO THREE QUARTERS OF ANY INCH
ON AVERAGE FOR SCATTERED TO NUMEROUS SHOWERS TODAY THROUGH TUESDAY.
SOME AREAS MAY OBSERVE VERY LITTLE QPF...WHILE OTHER AREAS COULD
RECEIVE IN EXCESS OF AN INCH...DEPENDING ON THE LOCATION OF ANY
HEAVIER SHOWERS.
AS SUCH...HIGHLY UNCERTAIN RAINFALL AMOUNTS FOR ANY PARTICULAR
LOCATION CONTINUE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT TUESDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MPS/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...MPS
AVIATION...JM
MARINE...MPS/PW
HYDROLOGY...PW
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
901 AM CDT MON MAY 21 2012
.PREV DISCUSSION...
345 AM CDT
08Z SURFACE ANALYSIS DEPICTS LOW PRESSURE NORTHEAST OF THE LAKES
ACROSS EASTERN ONTARIO...WITH ITS COLD FRONT TRAILING THROUGH
INDIANA AND INTO THE BOOTHEEL OF MISSOURI. RAIN CONTINUES TO WEAKEN
AND ERODE THROUGH THE FRONTAL ZONE...WITH JUST A FEW SCATTERED
SHOWERS LINGERING ACROSS THE IL/IND STATE LINE INTO NORTHWEST
INDIANA AT THIS TIME. SHORT TERM HIGH-RES GUIDANCE INDICATES PRECIP
WILL CONTINUE TO WEAKEN AND DRIFT OFF TO THE EAST EARLY THIS MORNING
WITH CLOUDS ALSO SLOWLY MOVING EAST. THUS WILL START OF THE FORECAST
WITH A LOW POP ACROSS NORTHWEST INDIANA FOR LINGERING EARLY SHOWERS
AND WILL HAVE MOSTLY CLOUDY THIS AM/BECOMING MOSTLY SUNNY LATER FOR
MOST AREAS. AFTER HIGHS IN THE LOWER 90S AGAIN SUNDAY...TODAY WILL
BE MUCH COOLER WITH TEMPS A GOOD 20-25 DEGREES LOWER. WINDS TURNING
NORTH-NORTHEAST LATER THIS MORNING SHOULD LIMIT AREAS ALONG THE LAKE
TO THE LOW-MID 60S...WITH LOWER 70S ACROSS THE FAR WESTERN CWA.
AN ELONGATED AREA OF SURFACE HIGH PRESSURE WILL SPREAD SLOWLY
EAST-SOUTHEAST FROM THE UPPER MIDWEST ACROSS THE WESTERN GREAT LAKES
THROUGH TUESDAY...PROVIDING DRY/PLEASANT WEATHER WITH COOL
NIGHTTIME TEMPS IN THE MID 40S-LOWER 50S...AND DAYTIME HIGHS IN THE
LOW-MID 70S WITH 60S AGAIN ALONG THE LAKE. SOUTH-SOUTHEAST WINDS
WILL STRENGTHEN TUESDAY NIGHT INTO WEDNESDAY AS THE SURFACE RIDGE
MOVES OFF TO THE EAST AND AN AREA OF LOW PRESSURE LIFTS NORTHEAST
ACROSS THE NORTHERN PLAINS. BREEZY WARM ADVECTION WILL PUSH TEMPS
BACK INTO THE UPPER 70S/LOW 80S WEDNESDAY AND INTO THE MID-UPPER 80S
THURSDAY AS BROAD UPPER TROUGH DEVELOPS OVER THE WESTERN CONUS AND
DEVELOPS DEEP SOUTH-SOUTHWEST FLOW ALOFT. BOTH DAYS WILL FEATURE
SOME MODEST LAKE COOLING ALONG THE NORTH SHORE...AS SFC WINDS
MAINTAIN A SOUTHEASTERLY COMPONENT.
LONGER RANGE MODELS ARE IN GOOD AGREEMENT IN DEPICTING A FAIRLY
STOUT SHORT WAVE TROUGH AND ASSOCIATED SURFACE LOW WHICH EMERGE FROM
THE WESTERN TROUGH AND LIFT ACROSS THE UPPER MIDWEST/NORTHERN LAKES
IN THE LATE THURSDAY/FRIDAY PERIOD...AND EVENTUALLY TRAIL A COLD
FRONT INTO THE FORECAST AREA FRIDAY. THERE ARE SOME DIFFERENCES AS
TO HOW QUICKLY THIS OCCURS AND JUST HOW FAR SOUTH THE FRONT SETTLES
BEFORE STALLING OUT FRIDAY NIGHT/SATURDAY. OVERALL HAVE BASED
FORECAST ON SLIGHTLY SLOWER ECMWF RATHER THAN FASTER GFS SOLUTION
AND THUS HAVE GENERALLY LOW CHANCE POPS THURSDAY NIGHT/FRIDAY ACROSS
THE NORTHERN PORTIONS OF THE FORECAST AREA...AND COOLER TEMPS MAINLY
FAR NORTH/ALONG THE LAKE FRIDAY. SATURDAY FEATURES A RELATIVELY
LARGE THERMAL SPREAD WITH NORTHEAST FLOW OFF THE LAKE WITH FRONT
STALLED OUT ACROSS CENTRAL IL/IND...WITH TEMPS RANGING FROM NEAR 90
FAR SOUTH CLOSE TO THE BOUNDARY TO THE MID 60S RIGHT AT THE LAKE
SHORE.
UPPER RIDGE THEN BEGINS TO BUILD ALOFT AS LOW LEVEL FRONT STALLS
OUT...WITH FORECAST SOUNDINGS INDICATING RELATIVELY STRONG CAPPING
WITH WARMING TEMPS ALOFT. FOR THIS REASON HAVE FOLLOWED THE DRIER
ECMWF WITH RESPECT TO PRECIP/LACK THEREOF IN THE SATURDAY/SUNDAY
PERIOD. WARM FRONT THEN LIFTS BACK NORTH/NORTHEAST SUNDAY...THOUGH
MODELS DIFFER IN JUST HOW QUICKLY THIS OCCURS. WITH SOMEWHAT LOW
CONFIDENCE AT THIS GREAT DISTANCE HAVE USED A BLEND OF ECMWF-GFS
FRONTAL POSITION SUNDAY WHICH RESULTS IN KEEPING A SOUTHEASTERLY
COMPONENT TO SFC WINDS ALONG NORTH SHORE ONCE AGAIN. WARM LOW LEVEL
THERMAL FIELDS SUPPORT UPPER 80S/LOW 90S...WITH COOLER TEMPS ALONG
THE IL LAKE SHORE.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* GUSTY NORTHWEST WINDS
* MORNING MVFR CIGS
ZEBIC
//DISCUSSION...UPDATED 12Z...
SURFACE COLD FRONT CONTINUES TO SHIFT THROUGH THE REGION THIS
EVENING...ENDING PRECIP AND FLIPPING TO WINDS AROUND TO THE
NORTH. MVFR CIGS ARE NOTED ACROSS MOST OF THE TRACON THIS
MORNING...AND NOT EXPECTING ANYTING TO FALL LOWER THAN THE 023 TO
025 RANGE. DRY AIR IS QUICKLY ADVANCING...AND DESPITE A SUBSIDENCE
INVERSION...SHOULD SEE THESE QUICKLY BREAK UP THIS MORNING IN THE
14 TO 15Z HOUR. WINDS ARE PROGGED TO REMAIN NORTHERLY AND FLOP TO
THE NORTHEAST. CLIMATOLOGICALLY SPEAKING...WINDS TYPICALLY WONT
STAY OUT OF THE NORTH...BUT SHIFT EAST OF NORTH. NOT THE MOST
CONFIDENT IT WILL HAPPEN AT 15Z...BUT MORE CONFIDENT WITH WINDS
TURNING TOWARDS 040 BY 20Z. LATEST RAP AND HRRR DATA ARE
INDICATING HIGHER WIND GUSTS AND SUSPECT THAT ORD WILL SEE LOW 20
KT GUSTS THIS AFTERNOON WHILE GYY IS FLIRTING WITH 30 KT.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MODERATE TO HIGH CONFIDENCE ON CIG FORECAST
* MODERATE TO HIGH CONFIDENCE IN WIND FORECAST
* HIGH CONFIDENCE IN DRY FORECAST
ZEBIC
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
WEDNESDAY...VFR.
THURSDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA LATE.
FRIDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA.
SATURDAY AND SUNDAY...VFR.
SHEA
&&
.MARINE...
334 AM CDT
LOW PRESSURE CONTINUES TO LIFT INTO ONTARIO THIS MORNING...AND A
COLD FRONT MOVED THROUGH. SHOWERS AND THUNDERSTORMS HAVE COME TO
AN END AND SURFACE HIGH PRESSURE WILL BE SWINGING OVERHEAD. THE
PRESSURE GRADIENT WILL REMAIN HIGH THROUGH THE MORNING HOURS AND
ALLOW WIND GUSTS TO APPROACH 25 KT FOR MOST OF THE INDIANA
NEARSHORE WATERS. NOT FULLY CONFIDENT THAT THE ILLINOIS ZONES WILL
BE SPARED AND WILL INCLUDE LMZ742 /NORTHERLY ISLAND/ THROUGH
MICHIGAN CITY. WINDS WILL ABATE THIS AFTERNOON BUT WAVES ARE
EXPECTED TO REMAIN ABOVE CRITERIA THROUGH TOMORROW MORNING. HIGH
PRESSURE WILL THEN DOMINATE THE PATTERN THROUGH MID WEEK...BEFORE
STRONG SOUTHERLY FLOW RETURNS.
SHEA
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ742-LMZ743-LMZ744-LMZ745...1 PM MONDAY
TO 10 AM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
652 AM CDT MON MAY 21 2012
.DISCUSSION...
345 AM CDT
08Z SURFACE ANALYSIS DEPICTS LOW PRESSURE NORTHEAST OF THE LAKES
ACROSS EASTERN ONTARIO...WITH ITS COLD FRONT TRAILING THROUGH
INDIANA AND INTO THE BOOTHEEL OF MISSOURI. RAIN CONTINUES TO WEAKEN
AND ERODE THROUGH THE FRONTAL ZONE...WITH JUST A FEW SCATTERED
SHOWERS LINGERING ACROSS THE IL/IND STATE LINE INTO NORTHWEST
INDIANA AT THIS TIME. SHORT TERM HIGH-RES GUIDANCE INDICATES PRECIP
WILL CONTINUE TO WEAKEN AND DRIFT OFF TO THE EAST EARLY THIS MORNING
WITH CLOUDS ALSO SLOWLY MOVING EAST. THUS WILL START OF THE FORECAST
WITH A LOW POP ACROSS NORTHWEST INDIANA FOR LINGERING EARLY SHOWERS
AND WILL HAVE MOSTLY CLOUDY THIS AM/BECOMING MOSTLY SUNNY LATER FOR
MOST AREAS. AFTER HIGHS IN THE LOWER 90S AGAIN SUNDAY...TODAY WILL
BE MUCH COOLER WITH TEMPS A GOOD 20-25 DEGREES LOWER. WINDS TURNING
NORTH-NORTHEAST LATER THIS MORNING SHOULD LIMIT AREAS ALONG THE LAKE
TO THE LOW-MID 60S...WITH LOWER 70S ACROSS THE FAR WESTERN CWA.
AN ELONGATED AREA OF SURFACE HIGH PRESSURE WILL SPREAD SLOWLY
EAST-SOUTHEAST FROM THE UPPER MIDWEST ACROSS THE WESTERN GREAT LAKES
THROUGH TUESDAY...PROVIDING DRY/PLEASANT WEATHER WITH COOL
NIGHTTIME TEMPS IN THE MID 40S-LOWER 50S...AND DAYTIME HIGHS IN THE
LOW-MID 70S WITH 60S AGAIN ALONG THE LAKE. SOUTH-SOUTHEAST WINDS
WILL STRENGTHEN TUESDAY NIGHT INTO WEDNESDAY AS THE SURFACE RIDGE
MOVES OFF TO THE EAST AND AN AREA OF LOW PRESSURE LIFTS NORTHEAST
ACROSS THE NORTHERN PLAINS. BREEZY WARM ADVECTION WILL PUSH TEMPS
BACK INTO THE UPPER 70S/LOW 80S WEDNESDAY AND INTO THE MID-UPPER 80S
THURSDAY AS BROAD UPPER TROUGH DEVELOPS OVER THE WESTERN CONUS AND
DEVELOPS DEEP SOUTH-SOUTHWEST FLOW ALOFT. BOTH DAYS WILL FEATURE
SOME MODEST LAKE COOLING ALONG THE NORTH SHORE...AS SFC WINDS
MAINTAIN A SOUTHEASTERLY COMPONENT.
LONGER RANGE MODELS ARE IN GOOD AGREEMENT IN DEPICTING A FAIRLY
STOUT SHORT WAVE TROUGH AND ASSOCIATED SURFACE LOW WHICH EMERGE FROM
THE WESTERN TROUGH AND LIFT ACROSS THE UPPER MIDWEST/NORTHERN LAKES
IN THE LATE THURSDAY/FRIDAY PERIOD...AND EVENTUALLY TRAIL A COLD
FRONT INTO THE FORECAST AREA FRIDAY. THERE ARE SOME DIFFERENCES AS
TO HOW QUICKLY THIS OCCURS AND JUST HOW FAR SOUTH THE FRONT SETTLES
BEFORE STALLING OUT FRIDAY NIGHT/SATURDAY. OVERALL HAVE BASED
FORECAST ON SLIGHTLY SLOWER ECMWF RATHER THAN FASTER GFS SOLUTION
AND THUS HAVE GENERALLY LOW CHANCE POPS THURSDAY NIGHT/FRIDAY ACROSS
THE NORTHERN PORTIONS OF THE FORECAST AREA...AND COOLER TEMPS MAINLY
FAR NORTH/ALONG THE LAKE FRIDAY. SATURDAY FEATURES A RELATIVELY
LARGE THERMAL SPREAD WITH NORTHEAST FLOW OFF THE LAKE WITH FRONT
STALLED OUT ACROSS CENTRAL IL/IND...WITH TEMPS RANGING FROM NEAR 90
FAR SOUTH CLOSE TO THE BOUNDARY TO THE MID 60S RIGHT AT THE LAKE
SHORE.
UPPER RIDGE THEN BEGINS TO BUILD ALOFT AS LOW LEVEL FRONT STALLS
OUT...WITH FORECAST SOUNDINGS INDICATING RELATIVELY STRONG CAPPING
WITH WARMING TEMPS ALOFT. FOR THIS REASON HAVE FOLLOWED THE DRIER
ECMWF WITH RESPECT TO PRECIP/LACK THEREOF IN THE SATURDAY/SUNDAY
PERIOD. WARM FRONT THEN LIFTS BACK NORTH/NORTHEAST SUNDAY...THOUGH
MODELS DIFFER IN JUST HOW QUICKLY THIS OCCURS. WITH SOMEWHAT LOW
CONFIDENCE AT THIS GREAT DISTANCE HAVE USED A BLEND OF ECMWF-GFS
FRONTAL POSITION SUNDAY WHICH RESULTS IN KEEPING A SOUTHEASTERLY
COMPONENT TO SFC WINDS ALONG NORTH SHORE ONCE AGAIN. WARM LOW LEVEL
THERMAL FIELDS SUPPORT UPPER 80S/LOW 90S...WITH COOLER TEMPS ALONG
THE IL LAKE SHORE.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* GUSTY NORTHWEST WINDS
* MORNING MVFR CIGYS
SHEA
//DISCUSSION...UPDATED 12Z...
SURFACE COLD FRONT CONTINUES TO SHIFT THROUGH THE REGION THIS
EVENING...ENDING PRECIP AND FLIPPING TO WINDS AROUND TO THE
NORTH. MVFR CIGS ARE NOTED ACROSS MOST OF THE TRACON THIS
MORNING...AND NOT EXPECTING ANYTING TO FALL LOWER THAN THE 023 TO
025 RANGE. DRY AIR IS QUICKLY ADVANCING...AND DESPITE A SUBSIDENCE
INVERSION...SHOULD SEE THESE QUICKLY BREAK UP THIS MORNING IN THE
14 TO 15Z HOUR. WINDS ARE PROGGED TO REMAIN NORTHERLY AND FLOP TO
THE NORTHEAST. CLIMATOLOGICALLY SPEAKING...WINDS TYPICALLY WONT
STAY OUT OF THE NORTH...BUT SHIFT EAST OF NORTH. NOT THE MOST
CONFIDENT IT WILL HAPPEN AT 15Z...BUT MORE CONFIDENT WITH WINDS
TURNING TOWARDS 040 BY 20Z. LATEST RAP AND HRRR DATA ARE
INDICATING HIGHER WIND GUSTS AND SUSPECT THAT ORD WILL SEE LOW 20
KT GUSTS THIS AFTERNOON WHILE GYY IS FLIRTING WITH 30 KT.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE ON CIG FORECAST
* MODERATE TO HIGH CONFIDENCE IN WIND FORECAST
* HIGH CONFIDENCE IN DRY FORECAST
SHEA
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
WEDNESDAY...VFR.
THURSDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA LATE.
FRIDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA.
SATURDAY AND SUNDAY...VFR.
SHEA
&&
.MARINE...
334 AM CDT
LOW PRESSURE CONTINUES TO LIFT INTO ONTARIO THIS MORNING...AND A
COLD FRONT MOVED THROUGH. SHOWERS AND THUNDERSTORMS HAVE COME TO
AN END AND SURFACE HIGH PRESSURE WILL BE SWINGING OVERHEAD. THE
PRESSURE GRADIENT WILL REMAIN HIGH THROUGH THE MORNING HOURS AND
ALLOW WIND GUSTS TO APPROACH 25 KT FOR MOST OF THE INDIANA
NEARSHORE WATERS. NOT FULLY CONFIDENT THAT THE ILLINOIS ZONES WILL
BE SPARED AND WILL INCLUDE LMZ742 /NORTHERLY ISLAND/ THROUGH
MICHIGAN CITY. WINDS WILL ABATE THIS AFTERNOON BUT WAVES ARE
EXPECTED TO REMAIN ABOVE CRITERIA THROUGH TOMORROW MORNING. HIGH
PRESSURE WILL THEN DOMINATE THE PATTERN THROUGH MID WEEK...BEFORE
STRONG SOUTHERLY FLOW RETURNS.
SHEA
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ742-745...1 PM MONDAY TO 10 AM
TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1032 AM EDT MON MAY 21 2012
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 338 AM EDT MON MAY 21 2012
SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY
WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH
PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR
TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL
BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL
BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE
WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE
HOTTEST TEMPERATURES OF THE YEAR SO FAR.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 922 AM EDT MON MAY 21 2012
ANALYSIS AS OF 915AM THIS MORING DEPICTS A SURFACE COLD FRONT
MOVING ACROSS THE WESTERN COUNTIES OF THE CWA EARLY THIS MORNING...
THE PASSAGE OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT
TO NORTHWEST WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA
DURING THE COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO
DIMINISH EARLY THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT
IS LIMITED. CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL
DECREASE OVER THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY
ALONG AND AHEAD OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY
BY MID/LATE MORNING OVER THE EASTERN HALF OF THE FORECAST AREA.
HAVE FOCUSED HIGHEST POPS SOUTH AND EAST OF THE INDY METRO WHERE
COMBINATION OF THE INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD
PROMOTE LARGELY DISORGANIZED AND SCATTERED CONVECTION INTO THE
AFTERNOON.
WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO
ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES
INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE
AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING
INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL
ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST
INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE
FORECAST AREA.
TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE
FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH
LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS
AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 338 AM EDT MON MAY 21 2012
FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING
TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT.
UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT...
EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST
STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD
OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO
WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS.
THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD
COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW
LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK
SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA...
INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH
MOSTLY SUNNY SKIES EXPECTED.
RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND
WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN
APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE
OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE
ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES
WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT
WILL CONTINUE THROUGH THE REST OF THE WEEK.
TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH
TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS
WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP
INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES
WITH 50S ELSEWHERE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON MAY 21 2012
MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT
GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN
BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN
KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE
PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT
WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH
THIS PACKAGE.
THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND
REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND
DEWPOINTS AND SKY COVER AS NECESSARY.
UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO
THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY
WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT
INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD
SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM
REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO.
&&
.AVIATION /DISCUSSION FOR THE 211500Z KIND TAF UPDATE/...
ISSUED AT 1032 AM EDT MON MAY 21 2012
MINOR TEAKS MADE TO KIND TAF PER OBSERVATIONS UPSTREAM.
OTHERWISE...NO OTHER CHANGES NEEDED AT THIS TIME. PREVIOUS AVIATION
DISCUSSION FOLLOWS...
MOSTLY VFR CONDITIONS THIS PERIOD...BUT MVFR POSSIBLE THROUGH THE
FIRST SEVERAL HOURS OF THE TAF PERIOD.
A COLD FRONT WILL SLOWLY WORK ACROSS THE SITES TODAY FROM WEST TO
EAST. UNTIL IT PASSES...SCATTERED SHOWERS ARE POSSIBLE. PLACED VCSH
AT KIND/KBMG WHERE BEST CHANCES FOR SHOWERS WILL BE.
CURRENT LOCAL AND UPSTREAM OBSERVATIONS SHOW PATCHY MVFR CEILINGS
AND VISIBILITIES IN FOG. DO NOT SEE WIDESPREAD CONDITIONS AT THE
MOMENT...SO WILL NOT PUT MVFR AS PREDOMINANT IN THE FORECAST.
HOWEVER POTENTIAL EXISTS FOR PERIODS OF CEILINGS AROUND 2000FT EARLY
IN THE TAF PERIOD.
CLOUDS WILL SCATTER OUT THIS AFTERNOON AS DRIER AIR WORKS IN.
OVERNIGHT IT APPEARS SOME MOISTURE MAY RETURN TO THE EASTERN
SITES...SO KEPT A SCATTERED LAYER AROUND 3000FT.
WINDS WILL BECOME NORTH-NORTHWEST AND INCREASE INTO THE 10-15KT
RANGE TODAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/SMF
SHORT TERM...RYAN
LONG TERM....50
AVIATION...50/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
926 AM EDT MON MAY 21 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 338 AM EDT MON MAY 21 2012
SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY
WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH
PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR
TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL
BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL
BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE
WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE
HOTTEST TEMPERATURES OF THE YEAR SO FAR.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 922 AM EDT MON MAY 21 2012
ANALYSIS AS OF 915AM THIS MORING DEPICTS A SURFACE COLD FRONT
MOVING ACROSS THE WESTERN COUNTIES OF THE CWA EARLY THIS MORNING...
THE PASSAGE OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT
TO NORTHWEST WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA
DURING THE COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO
DIMINISH EARLY THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT
IS LIMITED. CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL
DECREASE OVER THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY
ALONG AND AHEAD OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY
BY MID/LATE MORNING OVER THE EASTERN HALF OF THE FORECAST AREA.
HAVE FOCUSED HIGHEST POPS SOUTH AND EAST OF THE INDY METRO WHERE
COMBINATION OF THE INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD
PROMOTE LARGELY DISORGANIZED AND SCATTERED CONVECTION INTO THE
AFTERNOON.
WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO
ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES
INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE
AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING
INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL
ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST
INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE
FORECAST AREA.
TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE
FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH
LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS
AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 338 AM EDT MON MAY 21 2012
FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING
TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT.
UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT...
EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST
STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD
OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO
WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS.
THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD
COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW
LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK
SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA...
INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH
MOSTLY SUNNY SKIES EXPECTED.
RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND
WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN
APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE
OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE
ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES
WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT
WILL CONTINUE THROUGH THE REST OF THE WEEK.
TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH
TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS
WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP
INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES
WITH 50S ELSEWHERE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON MAY 21 2012
MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT
GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN
BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN
KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE
PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT
WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH
THIS PACKAGE.
THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND
REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND
DEWPOINTS AND SKY COVER AS NECESSARY.
UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO
THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY
WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT
INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD
SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM
REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO.
&&
.AVIATION /DISCUSSION FOR THE 211200Z TAFS/...
ISSUED AT 615 AM EDT MON MAY 21 2012
MOSTLY VFR CONDITIONS THIS PERIOD...BUT MVFR POSSIBLE THROUGH THE
FIRST SEVERAL HOURS OF THE TAF PERIOD.
A COLD FRONT WILL SLOWLY WORK ACROSS THE SITES TODAY FROM WEST TO
EAST. UNTIL IT PASSES...SCATTERED SHOWERS ARE POSSIBLE. PLACED VCSH
AT KIND/KBMG WHERE BEST CHANCES FOR SHOWERS WILL BE.
CURRENT LOCAL AND UPSTREAM OBSERVATIONS SHOW PATCHY MVFR CEILINGS
AND VISIBILITIES IN FOG. DO NOT SEE WIDESPREAD CONDITIONS AT THE
MOMENT...SO WILL NOT PUT MVFR AS PREDOMINANT IN THE FORECAST.
HOWEVER POTENTIAL EXISTS FOR PERIODS OF CEILINGS AROUND 2000FT EARLY
IN THE TAF PERIOD.
CLOUDS WILL SCATTER OUT THIS AFTERNOON AS DRIER AIR WORKS IN.
OVERNIGHT IT APPEARS SOME MOISTURE MAY RETURN TO THE EASTERN
SITES...SO KEPT A SCATTERED LAYER AROUND 3000FT.
WINDS WILL BECOME NORTH-NORTHWEST AND INCREASE INTO THE 10-15KT
RANGE TODAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/SMF
SHORT TERM...RYAN
LONG TERM....50
AVIATION...50
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
615 AM EDT MON MAY 21 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 338 AM EDT MON MAY 21 2012
SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY
WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH
PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR
TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL
BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL
BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE
WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE
HOTTEST TEMPERATURES OF THE YEAR SO FAR.
&&
.NEAR TERM /TODAY/...
ISSUED AT 338 AM EDT MON MAY 21 2012
WELL DEFINED OUTFLOW FROM EARLIER CONVECTION MOVING INTO WESTERN
OHIO AS OF 07Z WITH WEAKENING SCATTERED CONVECTION LEFT IN ITS WAKE
OVER THE FORECAST AREA. ACTUAL COLD FRONT STILL WEST OF THE REGION
OVER CENTRAL ILLINOIS EARLY THIS MORNING. TEMPS WERE IN THE 60S AS
OF 07Z.
AS MENTIONED ABOVE...THE FRONTAL BOUNDARY APPEARS TO BE ALIGNED
ROUGHLY FROM JUST EAST OF KORD SOUTHWEST TO NEAR KSTL. THE PASSAGE
OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT TO NORTHWEST
WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA DURING THE
COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO DIMINISH EARLY
THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT IS LIMITED.
CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL DECREASE OVER
THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY ALONG AND AHEAD
OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY BY MID/LATE MORNING
OVER THE EASTERN HALF OF THE FORECAST AREA. HAVE FOCUSED HIGHEST
POPS SOUTH AND EAST OF THE INDY METRO WHERE COMBINATION OF THE
INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD PROMOTE LARGELY
DISORGANIZED AND SCATTERED CONVECTION INTO THE AFTERNOON.
WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO
ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES
INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE
AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING
INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL
ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST
INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE
FORECAST AREA.
TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE
FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH
LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS
AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 338 AM EDT MON MAY 21 2012
FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING
TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT.
UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT...
EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST
STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD
OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO
WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS.
THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD
COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW
LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK
SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA...
INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH
MOSTLY SUNNY SKIES EXPECTED.
RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND
WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN
APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE
OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE
ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES
WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT
WILL CONTINUE THROUGH THE REST OF THE WEEK.
TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH
TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS
WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP
INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES
WITH 50S ELSEWHERE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON MAY 21 2012
MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT
GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN
BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN
KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE
PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT
WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH
THIS PACKAGE.
THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND
REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND
DEWPOINTS AND SKY COVER AS NECESSARY.
UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO
THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY
WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT
INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD
SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM
REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO.
&&
.AVIATION /DISCUSSION FOR THE 211200Z TAFS/...
ISSUED AT 615 AM EDT MON MAY 21 2012
MOSTLY VFR CONDITIONS THIS PERIOD...BUT MVFR POSSIBLE THROUGH THE
FIRST SEVERAL HOURS OF THE TAF PERIOD.
A COLD FRONT WILL SLOWLY WORK ACROSS THE SITES TODAY FROM WEST TO
EAST. UNTIL IT PASSES...SCATTERED SHOWERS ARE POSSIBLE. PLACED VCSH
AT KIND/KBMG WHERE BEST CHANCES FOR SHOWERS WILL BE.
CURRENT LOCAL AND UPSTREAM OBSERVATIONS SHOW PATCHY MVFR CEILINGS
AND VISIBILITIES IN FOG. DO NOT SEE WIDESPREAD CONDITIONS AT THE
MOMENT...SO WILL NOT PUT MVFR AS PREDOMINANT IN THE FORECAST.
HOWEVER POTENTIAL EXISTS FOR PERIODS OF CEILINGS AROUND 2000FT EARLY
IN THE TAF PERIOD.
CLOUDS WILL SCATTER OUT THIS AFTERNOON AS DRIER AIR WORKS IN.
OVERNIGHT IT APPEARS SOME MOISTURE MAY RETURN TO THE EASTERN
SITES...SO KEPT A SCATTERED LAYER AROUND 3000FT.
WINDS WILL BECOME NORTH-NORTHWEST AND INCREASE INTO THE 10-15KT
RANGE TODAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....50
AVIATION...50
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1000 AM EDT MON MAY 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST OF THE REGION TODAY. A WARM FRONT
WILL THEN MOVE NORTH...SPREADING SHOWERS INTO NORTHERN NEW
ENGLAND. A COLD FRONT WILL MOVE SLOWLY EAST AND SPARK SHOWERS AND
THUNDERSTORMS TUESDAY AND WEDNESDAY. HIGH PRESSURE WILL BE IN
CONTROL THURSDAY AND FRIDAY. A COLD FRONT WILL TRIGGER SHOWERS AND
STORMS ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.UPDATE...
STRATUS DECK HAS REACHED SOUTHERN NH AND IS SLOWING DOWN THANKS TO
DIURNAL HEATING. AREA OF CONVECTION IS WELL SOUTH OF THE AREA OVER
LONG ISLAND. THE HRRR INITIALIZES WELL WITH SHOWERS BREAKING UP
LATER IN THE DAY AS THEY MOVE NORTH INTO STRONG RIDGING. DRIZZLE
LOOKS LESS LIKELY AND HAVE REMOVED IT FROM THE FORECAST. RAIN
LOOKS TO ARRIVE CLOSER TO 03-06Z IN NH AND WORK NORTH. ALSO
ADJUSTED TEMPERATURES UP SLIGHTLY ESPECIALLY OVER SOUTHERN
SECTIONS.
&&
PREVIOUS DISCUSSION...SFC RIDGING REMAINS IN CONTROL OF THE
CWA...AT LEAST FOR THE EARLY PART OF THE DAY. WARM FNT IS LAYING
ALONG THE S COAST OF NEW ENGLAND ATTM...AND SLOWLY LIFTING NWD. AS
IT REACHES THE SRN CWA EARLY THIS AFTN...ONSHORE FLOW WILL PROMOTE
LOW CLOUD AND FOG DEVELOPMENT. WEAK LIFT IN THE LWR LVLS WILL ALSO
MEAN PATCHY DZ IS PSBL UNTIL DEEPER MOISTURE ARRIVES LATE IN THE
AFTN AND EVE. EXPECT COOLER TEMPS TODAY AS A RESULT OF INCREASING
CLOUDS. THE COOLEST LOCATIONS WILL BE ALONG THE COAST AND IN SRN
NH WHERE CLOUDS AND ONSHORE FLOW BEGIN EARLIEST. EARLY SUN IN THE
NRN HALF OF THE AREA WILL ALLOW HIGHS TO CLIMB INTO THE 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
NOCTURNAL COOLING WILL LEAD TO FURTHER LOWERING OF THE CLOUDS AND
MORE FOG/DZ SE OF THE MTNS. SHRA WILL BE MOST LIKELY ALONG THE
COAST. ABUNDANT CLOUD COVER WILL KEEP TNGT MILD...WITH LOWS
STAYING MAINLY IN THE 50S.
LOW PRES DEVELOPING S OF NEW ENGLAND WILL LIFT NWD...AND PASS
OFFSHORE AS A COLD FNT APPROACHES FROM THE W. SW FLOW ALOFT AHEAD
OF THE FNT WILL ENCOURAGE TROPICAL MOISTURE TO THE E OF T.S.
ALBERTO TO SURGE TOWARDS THE REGION. PWAT VALUES WILL INCREASE
LATE TNGT INTO TUE...NEARING 1.5 INCHES AT TIMES. THESE TYPES OF
VALUES ARE APPROACHING +2SD FOR THIS AREA...AND COUPLED WITH WARM
CLOUD DEPTHS IN EXCESS OF 10KFT...BRIEF PDS OF HEAVY RAFL WILL BE
PSBL. MODEL GUIDANCE HAS BEEN SLOW TO LATCH ONTO HEAVIER QPF...BUT
THE 20/12Z ECMWF HAS ENHANCED PCPN TO THE N OF THE COASTAL LOW
PRES. IT ALSO SEEMED A LITTLE TOO AGGRESSIVE ON LOW PRES
DEVELOPMENT...SO A COMPROMISE WAS USED. WITH DEEP MOISTURE AND
COLD FNT APPROACHING FROM THE W...STILL FEEL THAT HEAVIER RAIN
WILL GET SQUEEZED OUT OF THE SYSTEM SOMEWHERE. THE PROGRESSIVE
NATURE OF THE FEATURES WILL PRECLUDE ANY HYDRO ISSUES AS THINGS
STAND RIGHT NOW.
AHEAD OF THE COLD FNT...SOME DIURNAL HEATING AND STEEPER LAPSE
RATES COULD PRODUCE ENOUGH INSTABILITY FOR THUNDER. MOST LIKELY
AREAS WOULD BE IN THE CT RIVER VALLEY AND NRN MTNS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
A BROAD SOUTHEAST FLOW BOTH AT THE SURFACE AND ALOFT WILL CONTINUE
FROM WELL OUT INTO THE OPEN ATLANTIC EARLY TUESDAY EVENING. THIS WILL
ALLOW FOR MOISTURE TO CONT TO POOL ACROSS THE REGION...WITH THE
THICKEST CLOUD COVER AND POSSIBLY SOME PATCHY FOG RIGHT ALONG THE
SHORELINE.
BY LATE TUESDAY NIGHT...A WEAK TROUGH OF LOW PRESSURE
WILL PASS TO OUR EAST. THIS WILL BRING SLIGHTLY DRIER AIR INTO OUR
REGION...ALLOWING FOR OUR POPS TO LOWER AS WELL. HOWEVER DURING
THE DAY WEDNESDAY...THE FLOW BECOMES ALIGNED OUT OF THE SSE ONCE
AGAIN. THIS WILL ALLOW FOR WARM...MUGGY CONDS WITH INCREASING DEW
POINTS AND JUST A SLGT CHC FOR A SHOWER DURING THE PERIOD. THIS
WILL HOLD TRUE FOR THU AND FRI. THEREAFTER...A STG COLD FRONT
ENTERS THE REGION BY SATURDAY. HAVE ADDED A CHC FOR A TSTM DURING
THIS PERIOD AS THE ATMOS BECOMES MORE UNSTABLE WITH TIME.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
SHORT TERM...WARM FNT WILL LIFT INTO THE AREA DURING THE DAY
TODAY. VFR CONDS WILL GIVE WAY TO MVFR...AND EVENTUALLY IFR OR
LOWER CONDS AS LOW CLOUDS AND FOG MOVE ONSHORE IN SE FLOW. EXPECT
KCON AND ESPECIALLY KPSM TO DETERIORATE IN THE EARLY AFTN...WITH
KPWM/KAUG/KRKD FOLLOWING IN THE LATE AFTN/EVE. KLEB AND KHIE WILL
REMAIN VFR THE LONGEST...WITH MVFR CONDS PSBL LATE TNGT.
LONG TERM...MVFR CEILINGS AND VISIBILITIES ARE POSSIBLE TUESDAY NIGHT
AND WEDNESDAY IN SHOWERS AND FOG AS A FRONT MOVES THROUGH THE
AREA. VFR CONDITIONS ARE EXPECTED THURSDAY THROUGH FRIDAY.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS EXPECTED TO REMAIN BLO SCA THRESHOLDS
TODAY. LOW PRES PASSING SE OF THE WATERS TUE WILL BUILD SEAS ABOVE
5 FT ON THE OUTER WATERS DURING THE DAY. WINDS MAY BRIEFLY
APPROACHING 25 KT IF LOW PRES CAN TRACK FURTHER INTO GULF OF
MAINE.
LONG TERM...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA
THROUGH THURSDAY.
&&
.FIRE WEATHER...
SUNNY AND DRY START TO THE DAY WILL GIVE WAY TO INCREASING CLOUDS
AND MOISTURE AS A WARM FRONT LIFTS NORTH INTO THE AREA. SCATTERED
SHOWERS AND HIGH RELATIVE HUMIDITIES WILL LAST UNTIL WEDNESDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1034 AM CDT MON MAY 21 2012
.UPDATE...LIGHT SHOWERS HAVE BEGUN TO DISSIPATE ACROSS THE
FORECAST AREA.
&&
.PREV DISCUSSION... /ISSUED 550 AM CDT MON MAY 21 2012/
AVIATION...12Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT THE
TERMINAL THROUGH THE NEXT 24 HOURS. MID TO HIGH LEVEL CLOUDS WILL
BE NOTED TODAY...BUT NOTHING BELOW 10000FT AGL. SURFACE WINDS WILL
REMAIN FROM THE SOUTH...INCREASING TO AROUND 15KTS LATER TODAY.
VISIBILITY RESTRICTIONS ARE NOT ANTICIPATED THROUGH THE NEXT 24
HOURS.
PREV DISCUSSION... /ISSUED 447 AM CDT MON MAY 21 2012/
SHORT TERM...ALTHOUGH THE MAJORITY OF THE NEXT 72 HOURS SHOULD
REMAIN DRY...WILL HAVE TO DEAL WITH AT LEAST SOME SPRINKLES/BRIEF
SHOWERS THIS MORNING MAINLY IN THE NORTH...AND EVENTUALLY WHAT
SHOULD BE A MORE WIDESPREAD THUNDERSTORM RISK IN SOME AREAS
WEDNESDAY EVENING/NIGHT. ALSO OF CONCERN IS POSSIBLE
ADVISORY-LEVEL SOUTHERLY WIND ON TUESDAY.
08Z OBJECTIVE SURFACE ANALYSIS PLACES A BROAD 1025MB RIDGE AXIS
ACROSS EASTERN NEB...PROVIDING NEAR CALM TO VERY LIGHT
EAST/SOUTHEAST BREEZES TO THE CWA. ALTHOUGH MID LEVEL CLOUDS WILL
BE ON THE INCREASE THROUGH SUNRISE...MAINLY CLEAR SKIES THUS FAR
TONIGHT HAVE RESULTED IN AN EFFICIENT COOL DOWN INTO THE MID/UPPER
40S IN MOST AREAS. SPEAKING OF THOSE INCOMING MID CLOUDS AND
INCORPORATING RADAR TRENDS...SURE ENOUGH AND AS SUSPECTED HERE 24
HOURS AGO...A NARROW NORTH-SOUTH BAND OF MID-LEVEL THETA-E
ADVECTION EVIDENT AT 700MB HAS SPARKED AN AREA OF AT THE VERY
LEAST SCATTERED SPRINKLES/LIGHT SHOWERS AND EVEN A FEW WEAK
THUNDERSTORMS THAT HAVE SO FAR LARGELY STAYED JUST OUTSIDE THE CWA
ALONG AN AXIS FROM NEAR VALENTINE TO NORTH PLATTE. WATER VAPOR
IMAGERY CONFIRMS BROAD NORTHWEST FLOW ALOFT OVER THE CENTRAL
PLAINS...AS THE REGION LIES ALONG THE NORTHEAST PERIPHERY OF A
BUILDING MID/UPPER RIDGE AXIS EXTENDING ALL THE WAY BACK TO THE
PACIFIC NORTHWEST...WHERE THE NEXT LARGER SCALE SHORTWAVE/UPPER
JET STREAK OF INTEREST IS ARRIVING ON THE SCENE.
THE IMMEDIATE ISSUE THROUGH AT LEAST THE NEXT 4-6 HOURS IS THE
EVOLUTION OF DEVELOPING SHOWER ACTIVITY THIS MORNING. THIS NARROW
CORRIDOR OF HIGH BASED CONVECTION IS CLASSICALLY LOCATED ALONG THE
LEADING EDGE OF 700MB THETA-E ADVECTION...AND IMMEDIATELY EAST OF
THE CORE OF THE 850MB LOW LEVEL JET CURRENTLY CENTERED FROM FAR
WESTERN KS INTO WESTERN NEB. AS USUAL...DETERMINISTIC MODELS SUCH
AS NAM/GFS/ECMWF ARE STRUGGLING TO FULLY CAPTURE THIS ACTIVITY IN
THEIR QPF FIELDS...WHILE HIGHER RESOLUTION SHORT TERM MODELS SUCH
AS THE HRRR AND 0Z 4KM WRF-NMM ARE PROVING BETTER. OBJECTIVE RUC
ANALYSIS AND 06Z NAM CONFIRM THAT ELEVATED MUCAPE VALUES MAINLY IN
THE 800-650MB LAYER ARE ONLY RUNNING A MEAGER 100 J/KG OR SO.
FOLLOWING THE 06Z NAM...THIS BAND OF MID LEVEL THETA-E ADVECTION
SHOULD CONTINUE TO STEADILY TRACK EAST MAINLY ACROSS THE NORTHERN
1/2 OF NEB THROUGH THE MORNING HOURS...AT LEAST PUTTING PARTS OF
THE NORTHERN CWA IN LINE FOR NUISANCE AND UNFORTUNATELY PREVIOUSLY
UN-ADVERTISED PRECIPITATION. HAVE DEBATED BETWEEN GOING WITH A
MEASURABLE POP/SHOWER AND MAYBE EVEN AN ISOLATED THUNDERSTORM
MENTION...BUT AT LEAST TO START OUT WITH THIS MORNING WILL
TRY...REPEAT TRY...TO GET AWAY WITH ONLY SCATTERED SPRINKLE
MENTION ALONG AND NORTH OF I-80 WITH EXPECTATION THAT MEASURABLE
PRECIP SHOULD NOT BE OVERLY WIDESPREAD. STAY TUNED FOR POSSIBLE
UPDATES HOWEVER AS RADAR TRENDS EVOLVE. OBVIOUSLY EVEN IF ANY
ROGUE LIGHTNING STRIKES TO MANAGE TO SNEAK IN...WOULD NOT
ANTICIPATE ANYTHING CLOSE TO BEING SEVERE...WITH EVEN SMALL HAIL
HARD TO COME BY. WITH EXPECTATION OF THIS BEING A MORNING-ONLY
ISSUE...HAVE NO PRECIP MENTION WITHIN THE CWA BEYOND 17Z...AS THE
AFTERNOON HOURS WILL FEATURE THE PRIMARY LOWER LEVEL INSTABILITY
AXIS SETTING UP WEST OF THE CWA ALONG AN AXIS FROM FAR WESTERN KS
NORTHWARD INTO WESTERN NEB. MEANWHILE...SOUTH/SOUTHEAST WIND WILL
BE ON THE INCREASE AS THE DAY WEARS ON...AS THE SURFACE RIDGE AXIS
DEPARTS EAST INTO IA/MO. AS A RESULT...THE AFTERNOON HOURS WILL
FEATURE SUSTAINED SPEEDS RANGING FROM NEAR 15 MPH IN FAR EASTERN
COUNTIES...TO 20-25 MPH IN SOME WESTERN AREAS ALONG WITH GUSTS TO
AROUND 30 MPH. TEMP WISE TODAY...CHANGED HIGHS LITTLE FROM
PREVIOUS FORECAST...AND FOLLOWED 0Z NAM RAW TEMPS QUITE CLOSELY.
ALTHOUGH PASSING MID LEVEL CLOUDS THIS MORNING COULD PUT A
TEMPORARY DELAY ON THE DIURNAL CLIMB...HAVE AIMED MOST OF THE CWA
INTO THE 77-81 RANGE FOR EVENTUAL HIGHS.
THIS EVENING/TONIGHT...ANY STORMS THAT MANAGE TO FORM OUT IN
WESTERN NEB LATE THIS AFTERNOON WITHIN THE INSTABILITY AXIS SHOULD
STEADILY FADE AWAY LONG BEFORE MAKING IT INTO THE CWA. THAT BEING
SAID...HAVE OPTED TO DISREGARD THE 00Z GFS SOLUTION WHICH BREAKS
OUT WIDESPREAD QPF TONIGHT MAINLY IN SOUTHWEST/CENTRAL KS...BUT
ALSO BRUSHING UP INTO THE KS ZONES OF OUR CWA. WITH THE NAM/ECMWF
AND 4KM WRF-NMM ESSENTIALLY SHOWING NOTHING OF THIS NATURE...IT
JUST SEEMS TOO MUCH AN OUTLIER AND HAVE KEPT THE ENTIRE CWA
PRECIP-FREE TONIGHT. ALOFT...THE HEART OF THE MID/UPPER RIDGE AXIS
WILL SET UP OVER THE CENTRAL PLAINS TONIGHT...AS THE UPSTREAM
TROUGH/JET STREAK START CROSSING THE NORTHERN ROCKIES. AT THE
SURFACE...STEADY SOUTHERLY BREEZES SHOULD HELP HOLD TEMPS UP ABOUT
10 DEGREES WARMER THAN THOSE THIS MORNING...AND HAVE MOST OF THE
CWA IN THE 55-58 RANGE FOR LOWS...WHICH IS VERY SLIGHTLY WARMER
THAN PREVIOUS FORECAST.
TUESDAY IS STILL SHAPING UP TO BE THE WARMEST DAY OF THE
WEEK...WITH PLENTY OF SOUTHERLY WIND TO GO WITH IT. STARTING WITH
STORM CHANCES...HAVE KEPT IT STORM FREE THROUGH THE DAY...AS EVEN
THOUGH DEWPOINTS WILL BE IN THE INCREASE INTO THE 50S IN MOST
AREAS WITH A CORRESPONDING INCREASE IN LOW LEVEL INSTABILITY...MID
LEVEL TEMPS WILL ALSO BE ON THE INCREASE...WITH NAM SOUNDINGS
CONFIRMING A DECENT CAPPING INVERSION. BY LATE AFTERNOON...THE
NAM/GFS/ECMWF ARE IN GENERAL AGREEMENT SETTING UP A 990-994MB LOW
IN FAR WESTERN NEBRASKA...WITH PRESSURE FALLS DURING THE DAY
SETTING UP QUITE A HEALTHY EAST-WEST SURFACE PRESSURE GRADIENT
DURING THE DAY. THIS GRADIENT...IN TANDEM WITH SHOULD BE PLENTY OF
SUN AND MIXING TO AT LEAST THE 800MB LEVEL SHOULD HELP CRANK UP
THE SOUTHERLY WIND. TAKING A CONSENSUS OF 00Z MET/MAV GUIDANCE FOR
SPEEDS...HAVE MOST OF THE CWA CURRENTLY TOPPING OUT IN THE 25-30
MPH RANGE FOR SUSTAINED SPEEDS...WHICH IF IT WERE TO HOLD WOULD
GENERALLY FALL JUST SHORT OF WIND ADVISORY CRITERIA.
HOWEVER...COULD EASILY FORESEE AT LEAST WESTERN PORTIONS OF THE
CWA ENDING UP WITH HIGHER SPEEDS OVER 30 MPH...AND ALTHOUGH WILL
FOREGO ANY HEADLINE ISSUANCE STILL BEING 3 PERIODS OUT...WILL
CONTINUE TO HIGHLIGHT AT LEAST NEAR-ADVISORY SPEEDS IN THE HWO.
CERTAINLY GUSTS TO AROUND 40 MPH SHOULD BE COMMON NO MATTER WHAT
DURING THE AFTERNOON. TEMP-WISE...AGAIN LEANED HEAVILY ON RAW 0Z
NAM NUMBERS...WHICH RESULTED IN LITTLE CHANGE FROM PREVIOUS ACROSS
EASTERN ZONES...BUT ACTUALLY A SLIGHT LOWERING IN WESTERN AREAS.
THIS RESULTS IN MOST AREAS TOPPING OUT BETWEEN 87-90...WHICH IS
STILL AT LEAST A FEW DEGREES ABOVE MET GUIDANCE. IF SURFACE
DEWPOINTS MANAGE TO MIX DOWN FURTHER THAN CURRENTLY THOUGHT...THEN
COULD EASILY SEE PARTS OF THE SOUTHWEST CWA TRY TO MAKE A RUN AT
MID 90S BUT WILL KEEP IT BELOW THIS FOR NOW.
TUESDAY NIGHT...KEPT IT STORM FREE DESPITE THE LEADING EDGE
FORCING FROM THE INCOMING SHORTWAVE/JET STREAK STARTING TO IMPINGE
ON WESTERN PORTIONS OF THE REGION. ALTHOUGH THE LOW LEVEL JET WILL
REALLY RAMP UP OVER THE CWA DURING THE NIGHT...SPEED CONVERGENCE
IS NOT REALLY PRESENT AND MORE IMPORTANTLY...VERY WARM MID LEVEL
TEMPS AS EVIDENCED BY 700MB TEMPS CLIMBING INTO AT LEAST THE
12-14C RANGE SHOULD PROVIDE A VERY STOUT CAP EVEN TO ELEVATED
PARCELS. EVEN WITH THE APPROACH OF A SURFACE-850MB COLD FRONT
AFTER MIDNIGHT ACROSS WESTERN NEB...JUST NOT SEEING THIS CAP
BREAKING WITH LARGE SCALE FORCING STILL LIMITED. TEMP
WISE...SHOULD BE A SEASONABLY MILD NIGHT AND LEFT LOWS PRETTY MUCH
ALONE IN THE LOW-MID 60S.
WEDNESDAY DAYTIME...OPTED TO STAY CONSISTENT WITH PREVIOUS
FORECAST AND LEAVE OUT STORM MENTION...BUT WILL SAY THAT WOULD NOT
BE SURPRISED IF AT LEAST A SLIGHT POP COULD BE ADDED AT SOME
POINT. THE MAIN THING HOLDING BACK A LEGITIMATE DAYTIME STORM THREAT
IS CONTINUED STRONG CAPPING...WITH THE LATEST 06Z NAM FINALLY
FALLING IN LINE WITH THE GFS/ECWMF SOLUTIONS IN KEEPING FAIRLY
TOASTY 700MB TEMPS IN PLACE THROUGH THE DAY...DESPITE THE INVASION
OF A SURFACE COLD FRONT INTO NORTHWEST PARTS OF THE CWA. EVEN THE
LATEST RUN OF THE SREF THUNDER PROBABILITIES HAS BACKED OFF A BIT
ON THE FAIRLY SLIM RISK OF PRE-00Z CONVECTIVE INITIATION. ASSUMING
THAT IT REMAINS STORM-FREE...THE MAIN ISSUE FOR WEDNESDAY IS A
TRICKY HIGH TEMP FORECAST...AS ALTHOUGH THE SOUTHEAST 1/2 OR SO OF
THE CWA SHOULD REMAIN FIRMLY IN THE WARM SECTOR...NORTHWEST ZONES
COULD SEE AT LEAST WEAK COLD AIR ADVECTION/NORTHEAST WIND. OPTED
TO WARM UP MOST AREAS 2-3 DEGREES FROM PREVIOUS FORECAST SIDING
WITH SLOWER INVASION OF COOLER AIR...NOW ADVERTISING A RANGE FROM
NEAR 80 FAR NORTHWEST TO LOW 90S SOUTHEAST.
WEDNESDAY NIGHT...THIS IS CLEARLY THE MOST FAVORED PERIOD FOR
POTENTIALLY...REPEATING POTENTIALLY WIDESPREAD THUNDERSTORM
ACTIVITY...AS MID LEVEL TEMPS SHOULD BE ABLE TO COOL ENOUGH AT
LEAST IN NORTHWEST ZONES TO ALLOW INITIATION. ON THE LARGER
SCALE...LEGITIMATE FORCING FINALLY ARRIVES IN THE FORM OF AN OPEN
MID LEVEL SHORTWAVE AND THE EXIT REGION OF A 300MB JET STREAK
APPROACHING FROM THE CENTRAL ROCKIES. THAT BEING SAID...LATEST
MODEL CONSENSUS IS TO REALLY LIMIT STORM DEVELOPMENT ACROSS
SOUTHEAST ZONES...WHILE MAINLY TARGETING NORTHWEST ZONES WITH
CONVECTION...AND LEAVING CENTRAL PLACES INCLUDING THE TRI CITIES A
BIT IN LIMBO. FOR NOW...OPTED TO KEEP POPS SIMILAR TO PREVIOUS
FORECAST...RANGING FROM LIKELY 60S IN THE NORTHWEST TO NO STORM
MENTION FAR SOUTHEAST...AND A GRADUAL GRADIENT OF SLIGHT CHANCE TO
CHANCE POPS IN BETWEEN. THE POTENTIAL IS CERTAINLY THERE FOR
A WIDESPREAD FLARE UP OF STORMS...AS THE NAM ADVERTISES
CONSIDERABLE CONVERGENCE ACROSS A SHARP 850MB FRONT...WITH A LOW
LEVEL JET POTENTIALLY IN EXCESS OF 60KT BLASTING INTO THIS
BOUNDARY. WITH ELEVATED INSTABILITY POTENTIALLY INTO THE 1000-2000
J/KG RANGE IN THE EVENING...ALONG WITH DEEP LAYER SHEAR ON THE
ORDER OF 50-70KT...A ROUND OF SEVERE STORMS WITH HAIL/WIND IS VERY
POSSIBLE...AGAIN MAINLY FAVORING THE LESS-CAPPED NORTHWEST ZONES.
CERTAINLY PLENTY OF DETAILS TO IRON OUT OVER THE NEXT FEW DAYS
THOUGH.
LONG TERM...STARTING 12Z THURSDAY. GUIDANCE CONTINUES TO SUGGEST MID
AND UPPER LEVEL JET ENERGY WILL PERSIST OVER THE CENTRAL PLAINS
THROUGH MUCH OF THE LONG TERM FORECAST PERIOD. AT THE SURFACE A
RIDGE HIGH PRESSURE IS EXPECTED TO DOMINATE THE LOW LEVELS
THURSDAY THROUGH MUCH OF FRIDAY...WITH LOW LEVEL RETURN FLOW
MATERIALIZING ACROSS THE AREA LATE FRIDAY ONWARD.
THE OPERATIONAL GFS AND EC BOTH ADVERTISE MID LEVEL PERTURBATIONS
WILL PUSH OVER THE AREA DURING THE DAY THURSDAY...WITH PERHAPS
ENOUGH OMEGA AND MOISTURE FOR PRECIPITATION PRODUCTION ACROSS
NORTHERN PORTIONS OF THE CWA. THE RIGHT-REAR QUADRANT OF A ~70KT MID
LEVEL JET STREAK IS THEN EXPECTED TO PROMOTE ENOUGH OF A DIRECT
THERMAL CIRCULATION FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE
CWA THURSDAY NIGHT INTO FRIDAY MORNING. AN OVERALL LACK IN KINEMATIC
FORCING IS THEN EXPECTED TO BRING DRY CONDITIONS TO THE AREA DURING
THE DAY FRIDAY...WITH THE EMERGENCE OF A ~40KT LOW LEVEL JET
BRINGING ANOTHER POSSIBILITY OF PRECIPITATION TO THE AREA FRIDAY
NIGHT INTO SATURDAY MORNING. ONE MORE ROUND OF NOCTURNAL
PRECIPITATION THEN APPEARS POSSIBLE SATURDAY NIGHT INTO SUNDAY
MORNING AS A STRONGER LOW LEVEL JET INFILTRATES THE AREA.
LOW LEVEL MOISTURE REMAINS LESS THAN IMPRESSIVE THROUGH FRIDAY AS
SURFACE RIDGING REMAINS ENTRENCHED ACROSS THE AREA AND AS A
RESULT...INSTABILITY SUFFERS GREATLY. CONTEMPLATED TAKEN THUNDER OUT
OF THE FORECAST ALTOGETHER THURSDAY AND THURSDAY NIGHT BUT WITH THE
OPERATIONAL GFS AND EC BOTH SUGGESTING MAYBE AROUND 100J/KG DEEP
LAYER MUCAPE VALUES...WENT AHEAD WITH ISOLATED THUNDER MENTION FOR
THAT TIME BEING. LOW LEVEL MOISTURE FLUX INTO THE AREA VIA LOW LEVEL
RETURN FLOW SHOULD ALLOW FOR INCREASING INSTABILITY VALUES HEADING
INTO THE WEEKEND...WITH 1000-2000J/KG DEEP LAYER MUCAPE VALUES BEING
ADVERTISED BY THE OPERATIONAL GFS AND EC.
NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES ARE STILL EXPECTED
THURSDAY AS SURFACE RIDGING REMAINS OVER THE AREA. LOW LEVEL RETURN
FLOW WILL THEN PROMOTE A WARMING TREND...WITH TEMPERATURES CLIMBING
TO LEVELS WELL ABOVE-NORMAL FOR THIS TIME OF YEAR ACROSS OUR SOUTH
ON FRIDAY...AND ACROSS THE ENTIRE CWA SATURDAY ONWARD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
550 AM CDT MON MAY 21 2012
.AVIATION...12Z KGRI TAF. VFR CONDITIONS TO CONTINUE AT THE
TERMINAL THROUGH THE NEXT 24 HOURS. MID TO HIGH LEVEL CLOUDS WILL
BE NOTED TODAY...BUT NOTHING BELOW 10000FT AGL. SURFACE WINDS WILL
REMAIN FROM THE SOUTH...INCREASING TO AROUND 15KTS LATER TODAY.
VISIBILITY RESTRICTIONS ARE NOT ANTICIPATED THROUGH THE NEXT 24
HOURS.
&&
.PREV DISCUSSION... /ISSUED 447 AM CDT MON MAY 21 2012/
SHORT TERM...ALTHOUGH THE MAJORITY OF THE NEXT 72 HOURS SHOULD
REMAIN DRY...WILL HAVE TO DEAL WITH AT LEAST SOME SPRINKLES/BRIEF
SHOWERS THIS MORNING MAINLY IN THE NORTH...AND EVENTUALLY WHAT
SHOULD BE A MORE WIDESPREAD THUNDERSTORM RISK IN SOME AREAS
WEDNESDAY EVENING/NIGHT. ALSO OF CONCERN IS POSSIBLE
ADVISORY-LEVEL SOUTHERLY WIND ON TUESDAY.
08Z OBJECTIVE SURFACE ANALYSIS PLACES A BROAD 1025MB RIDGE AXIS
ACROSS EASTERN NEB...PROVIDING NEAR CALM TO VERY LIGHT
EAST/SOUTHEAST BREEZES TO THE CWA. ALTHOUGH MID LEVEL CLOUDS WILL
BE ON THE INCREASE THROUGH SUNRISE...MAINLY CLEAR SKIES THUS FAR
TONIGHT HAVE RESULTED IN AN EFFICIENT COOL DOWN INTO THE MID/UPPER
40S IN MOST AREAS. SPEAKING OF THOSE INCOMING MID CLOUDS AND
INCORPORATING RADAR TRENDS...SURE ENOUGH AND AS SUSPECTED HERE 24
HOURS AGO...A NARROW NORTH-SOUTH BAND OF MID-LEVEL THETA-E
ADVECTION EVIDENT AT 700MB HAS SPARKED AN AREA OF AT THE VERY
LEAST SCATTERED SPRINKLES/LIGHT SHOWERS AND EVEN A FEW WEAK
THUNDERSTORMS THAT HAVE SO FAR LARGELY STAYED JUST OUTSIDE THE CWA
ALONG AN AXIS FROM NEAR VALENTINE TO NORTH PLATTE. WATER VAPOR
IMAGERY CONFIRMS BROAD NORTHWEST FLOW ALOFT OVER THE CENTRAL
PLAINS...AS THE REGION LIES ALONG THE NORTHEAST PERIPHERY OF A
BUILDING MID/UPPER RIDGE AXIS EXTENDING ALL THE WAY BACK TO THE
PACIFIC NORTHWEST...WHERE THE NEXT LARGER SCALE SHORTWAVE/UPPER
JET STREAK OF INTEREST IS ARRIVING ON THE SCENE.
THE IMMEDIATE ISSUE THROUGH AT LEAST THE NEXT 4-6 HOURS IS THE
EVOLUTION OF DEVELOPING SHOWER ACTIVITY THIS MORNING. THIS NARROW
CORRIDOR OF HIGH BASED CONVECTION IS CLASSICALLY LOCATED ALONG THE
LEADING EDGE OF 700MB THETA-E ADVECTION...AND IMMEDIATELY EAST OF
THE CORE OF THE 850MB LOW LEVEL JET CURRENTLY CENTERED FROM FAR
WESTERN KS INTO WESTERN NEB. AS USUAL...DETERMINISTIC MODELS SUCH
AS NAM/GFS/ECMWF ARE STRUGGLING TO FULLY CAPTURE THIS ACTIVITY IN
THEIR QPF FIELDS...WHILE HIGHER RESOLUTION SHORT TERM MODELS SUCH
AS THE HRRR AND 0Z 4KM WRF-NMM ARE PROVING BETTER. OBJECTIVE RUC
ANALYSIS AND 06Z NAM CONFIRM THAT ELEVATED MUCAPE VALUES MAINLY IN
THE 800-650MB LAYER ARE ONLY RUNNING A MEAGER 100 J/KG OR SO.
FOLLOWING THE 06Z NAM...THIS BAND OF MID LEVEL THETA-E ADVECTION
SHOULD CONTINUE TO STEADILY TRACK EAST MAINLY ACROSS THE NORTHERN
1/2 OF NEB THROUGH THE MORNING HOURS...AT LEAST PUTTING PARTS OF
THE NORTHERN CWA IN LINE FOR NUISANCE AND UNFORTUNATELY PREVIOUSLY
UN-ADVERTISED PRECIPITATION. HAVE DEBATED BETWEEN GOING WITH A
MEASURABLE POP/SHOWER AND MAYBE EVEN AN ISOLATED THUNDERSTORM
MENTION...BUT AT LEAST TO START OUT WITH THIS MORNING WILL
TRY...REPEAT TRY...TO GET AWAY WITH ONLY SCATTERED SPRINKLE
MENTION ALONG AND NORTH OF I-80 WITH EXPECTATION THAT MEASURABLE
PRECIP SHOULD NOT BE OVERLY WIDESPREAD. STAY TUNED FOR POSSIBLE
UPDATES HOWEVER AS RADAR TRENDS EVOLVE. OBVIOUSLY EVEN IF ANY
ROGUE LIGHTNING STRIKES TO MANAGE TO SNEAK IN...WOULD NOT
ANTICIPATE ANYTHING CLOSE TO BEING SEVERE...WITH EVEN SMALL HAIL
HARD TO COME BY. WITH EXPECTATION OF THIS BEING A MORNING-ONLY
ISSUE...HAVE NO PRECIP MENTION WITHIN THE CWA BEYOND 17Z...AS THE
AFTERNOON HOURS WILL FEATURE THE PRIMARY LOWER LEVEL INSTABILITY
AXIS SETTING UP WEST OF THE CWA ALONG AN AXIS FROM FAR WESTERN KS
NORTHWARD INTO WESTERN NEB. MEANWHILE...SOUTH/SOUTHEAST WIND WILL
BE ON THE INCREASE AS THE DAY WEARS ON...AS THE SURFACE RIDGE AXIS
DEPARTS EAST INTO IA/MO. AS A RESULT...THE AFTERNOON HOURS WILL
FEATURE SUSTAINED SPEEDS RANGING FROM NEAR 15 MPH IN FAR EASTERN
COUNTIES...TO 20-25 MPH IN SOME WESTERN AREAS ALONG WITH GUSTS TO
AROUND 30 MPH. TEMP WISE TODAY...CHANGED HIGHS LITTLE FROM
PREVIOUS FORECAST...AND FOLLOWED 0Z NAM RAW TEMPS QUITE CLOSELY.
ALTHOUGH PASSING MID LEVEL CLOUDS THIS MORNING COULD PUT A
TEMPORARY DELAY ON THE DIURNAL CLIMB...HAVE AIMED MOST OF THE CWA
INTO THE 77-81 RANGE FOR EVENTUAL HIGHS.
THIS EVENING/TONIGHT...ANY STORMS THAT MANAGE TO FORM OUT IN
WESTERN NEB LATE THIS AFTERNOON WITHIN THE INSTABILITY AXIS SHOULD
STEADILY FADE AWAY LONG BEFORE MAKING IT INTO THE CWA. THAT BEING
SAID...HAVE OPTED TO DISREGARD THE 00Z GFS SOLUTION WHICH BREAKS
OUT WIDESPREAD QPF TONIGHT MAINLY IN SOUTHWEST/CENTRAL KS...BUT
ALSO BRUSHING UP INTO THE KS ZONES OF OUR CWA. WITH THE NAM/ECMWF
AND 4KM WRF-NMM ESSENTIALLY SHOWING NOTHING OF THIS NATURE...IT
JUST SEEMS TOO MUCH AN OUTLIER AND HAVE KEPT THE ENTIRE CWA
PRECIP-FREE TONIGHT. ALOFT...THE HEART OF THE MID/UPPER RIDGE AXIS
WILL SET UP OVER THE CENTRAL PLAINS TONIGHT...AS THE UPSTREAM
TROUGH/JET STREAK START CROSSING THE NORTHERN ROCKIES. AT THE
SURFACE...STEADY SOUTHERLY BREEZES SHOULD HELP HOLD TEMPS UP ABOUT
10 DEGREES WARMER THAN THOSE THIS MORNING...AND HAVE MOST OF THE
CWA IN THE 55-58 RANGE FOR LOWS...WHICH IS VERY SLIGHTLY WARMER
THAN PREVIOUS FORECAST.
TUESDAY IS STILL SHAPING UP TO BE THE WARMEST DAY OF THE
WEEK...WITH PLENTY OF SOUTHERLY WIND TO GO WITH IT. STARTING WITH
STORM CHANCES...HAVE KEPT IT STORM FREE THROUGH THE DAY...AS EVEN
THOUGH DEWPOINTS WILL BE IN THE INCREASE INTO THE 50S IN MOST
AREAS WITH A CORRESPONDING INCREASE IN LOW LEVEL INSTABILITY...MID
LEVEL TEMPS WILL ALSO BE ON THE INCREASE...WITH NAM SOUNDINGS
CONFIRMING A DECENT CAPPING INVERSION. BY LATE AFTERNOON...THE
NAM/GFS/ECMWF ARE IN GENERAL AGREEMENT SETTING UP A 990-994MB LOW
IN FAR WESTERN NEBRASKA...WITH PRESSURE FALLS DURING THE DAY
SETTING UP QUITE A HEALTHY EAST-WEST SURFACE PRESSURE GRADIENT
DURING THE DAY. THIS GRADIENT...IN TANDEM WITH SHOULD BE PLENTY OF
SUN AND MIXING TO AT LEAST THE 800MB LEVEL SHOULD HELP CRANK UP
THE SOUTHERLY WIND. TAKING A CONSENSUS OF 00Z MET/MAV GUIDANCE FOR
SPEEDS...HAVE MOST OF THE CWA CURRENTLY TOPPING OUT IN THE 25-30
MPH RANGE FOR SUSTAINED SPEEDS...WHICH IF IT WERE TO HOLD WOULD
GENERALLY FALL JUST SHORT OF WIND ADVISORY CRITERIA.
HOWEVER...COULD EASILY FORESEE AT LEAST WESTERN PORTIONS OF THE
CWA ENDING UP WITH HIGHER SPEEDS OVER 30 MPH...AND ALTHOUGH WILL
FOREGO ANY HEADLINE ISSUANCE STILL BEING 3 PERIODS OUT...WILL
CONTINUE TO HIGHLIGHT AT LEAST NEAR-ADVISORY SPEEDS IN THE HWO.
CERTAINLY GUSTS TO AROUND 40 MPH SHOULD BE COMMON NO MATTER WHAT
DURING THE AFTERNOON. TEMP-WISE...AGAIN LEANED HEAVILY ON RAW 0Z
NAM NUMBERS...WHICH RESULTED IN LITTLE CHANGE FROM PREVIOUS ACROSS
EASTERN ZONES...BUT ACTUALLY A SLIGHT LOWERING IN WESTERN AREAS.
THIS RESULTS IN MOST AREAS TOPPING OUT BETWEEN 87-90...WHICH IS
STILL AT LEAST A FEW DEGREES ABOVE MET GUIDANCE. IF SURFACE
DEWPOINTS MANAGE TO MIX DOWN FURTHER THAN CURRENTLY THOUGHT...THEN
COULD EASILY SEE PARTS OF THE SOUTHWEST CWA TRY TO MAKE A RUN AT
MID 90S BUT WILL KEEP IT BELOW THIS FOR NOW.
TUESDAY NIGHT...KEPT IT STORM FREE DESPITE THE LEADING EDGE
FORCING FROM THE INCOMING SHORTWAVE/JET STREAK STARTING TO IMPINGE
ON WESTERN PORTIONS OF THE REGION. ALTHOUGH THE LOW LEVEL JET WILL
REALLY RAMP UP OVER THE CWA DURING THE NIGHT...SPEED CONVERGENCE
IS NOT REALLY PRESENT AND MORE IMPORTANTLY...VERY WARM MID LEVEL
TEMPS AS EVIDENCED BY 700MB TEMPS CLIMBING INTO AT LEAST THE
12-14C RANGE SHOULD PROVIDE A VERY STOUT CAP EVEN TO ELEVATED
PARCELS. EVEN WITH THE APPROACH OF A SURFACE-850MB COLD FRONT
AFTER MIDNIGHT ACROSS WESTERN NEB...JUST NOT SEEING THIS CAP
BREAKING WITH LARGE SCALE FORCING STILL LIMITED. TEMP
WISE...SHOULD BE A SEASONABLY MILD NIGHT AND LEFT LOWS PRETTY MUCH
ALONE IN THE LOW-MID 60S.
WEDNESDAY DAYTIME...OPTED TO STAY CONSISTENT WITH PREVIOUS
FORECAST AND LEAVE OUT STORM MENTION...BUT WILL SAY THAT WOULD NOT
BE SURPRISED IF AT LEAST A SLIGHT POP COULD BE ADDED AT SOME
POINT. THE MAIN THING HOLDING BACK A LEGITIMATE DAYTIME STORM THREAT
IS CONTINUED STRONG CAPPING...WITH THE LATEST 06Z NAM FINALLY
FALLING IN LINE WITH THE GFS/ECWMF SOLUTIONS IN KEEPING FAIRLY
TOASTY 700MB TEMPS IN PLACE THROUGH THE DAY...DESPITE THE INVASION
OF A SURFACE COLD FRONT INTO NORTHWEST PARTS OF THE CWA. EVEN THE
LATEST RUN OF THE SREF THUNDER PROBABILITIES HAS BACKED OFF A BIT
ON THE FAIRLY SLIM RISK OF PRE-00Z CONVECTIVE INITIATION. ASSUMING
THAT IT REMAINS STORM-FREE...THE MAIN ISSUE FOR WEDNESDAY IS A
TRICKY HIGH TEMP FORECAST...AS ALTHOUGH THE SOUTHEAST 1/2 OR SO OF
THE CWA SHOULD REMAIN FIRMLY IN THE WARM SECTOR...NORTHWEST ZONES
COULD SEE AT LEAST WEAK COLD AIR ADVECTION/NORTHEAST WIND. OPTED
TO WARM UP MOST AREAS 2-3 DEGREES FROM PREVIOUS FORECAST SIDING
WITH SLOWER INVASION OF COOLER AIR...NOW ADVERTISING A RANGE FROM
NEAR 80 FAR NORTHWEST TO LOW 90S SOUTHEAST.
WEDNESDAY NIGHT...THIS IS CLEARLY THE MOST FAVORED PERIOD FOR
POTENTIALLY...REPEATING POTENTIALLY WIDESPREAD THUNDERSTORM
ACTIVITY...AS MID LEVEL TEMPS SHOULD BE ABLE TO COOL ENOUGH AT
LEAST IN NORTHWEST ZONES TO ALLOW INITIATION. ON THE LARGER
SCALE...LEGITIMATE FORCING FINALLY ARRIVES IN THE FORM OF AN OPEN
MID LEVEL SHORTWAVE AND THE EXIT REGION OF A 300MB JET STREAK
APPROACHING FROM THE CENTRAL ROCKIES. THAT BEING SAID...LATEST
MODEL CONSENSUS IS TO REALLY LIMIT STORM DEVELOPMENT ACROSS
SOUTHEAST ZONES...WHILE MAINLY TARGETING NORTHWEST ZONES WITH
CONVECTION...AND LEAVING CENTRAL PLACES INCLUDING THE TRI CITIES A
BIT IN LIMBO. FOR NOW...OPTED TO KEEP POPS SIMILAR TO PREVIOUS
FORECAST...RANGING FROM LIKELY 60S IN THE NORTHWEST TO NO STORM
MENTION FAR SOUTHEAST...AND A GRADUAL GRADIENT OF SLIGHT CHANCE TO
CHANCE POPS IN BETWEEN. THE POTENTIAL IS CERTAINLY THERE FOR
A WIDESPREAD FLARE UP OF STORMS...AS THE NAM ADVERTISES
CONSIDERABLE CONVERGENCE ACROSS A SHARP 850MB FRONT...WITH A LOW
LEVEL JET POTENTIALLY IN EXCESS OF 60KT BLASTING INTO THIS
BOUNDARY. WITH ELEVATED INSTABILITY POTENTIALLY INTO THE 1000-2000
J/KG RANGE IN THE EVENING...ALONG WITH DEEP LAYER SHEAR ON THE
ORDER OF 50-70KT...A ROUND OF SEVERE STORMS WITH HAIL/WIND IS VERY
POSSIBLE...AGAIN MAINLY FAVORING THE LESS-CAPPED NORTHWEST ZONES.
CERTAINLY PLENTY OF DETAILS TO IRON OUT OVER THE NEXT FEW DAYS
THOUGH.
LONG TERM...STARTING 12Z THURSDAY. GUIDANCE CONTINUES TO SUGGEST MID
AND UPPER LEVEL JET ENERGY WILL PERSIST OVER THE CENTRAL PLAINS
THROUGH MUCH OF THE LONG TERM FORECAST PERIOD. AT THE SURFACE A
RIDGE HIGH PRESSURE IS EXPECTED TO DOMINATE THE LOW LEVELS
THURSDAY THROUGH MUCH OF FRIDAY...WITH LOW LEVEL RETURN FLOW
MATERIALIZING ACROSS THE AREA LATE FRIDAY ONWARD.
THE OPERATIONAL GFS AND EC BOTH ADVERTISE MID LEVEL PERTURBATIONS
WILL PUSH OVER THE AREA DURING THE DAY THURSDAY...WITH PERHAPS
ENOUGH OMEGA AND MOISTURE FOR PRECIPITATION PRODUCTION ACROSS
NORTHERN PORTIONS OF THE CWA. THE RIGHT-REAR QUADRANT OF A ~70KT MID
LEVEL JET STREAK IS THEN EXPECTED TO PROMOTE ENOUGH OF A DIRECT
THERMAL CIRCULATION FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE
CWA THURSDAY NIGHT INTO FRIDAY MORNING. AN OVERALL LACK IN KINEMATIC
FORCING IS THEN EXPECTED TO BRING DRY CONDITIONS TO THE AREA DURING
THE DAY FRIDAY...WITH THE EMERGENCE OF A ~40KT LOW LEVEL JET
BRINGING ANOTHER POSSIBILITY OF PRECIPITATION TO THE AREA FRIDAY
NIGHT INTO SATURDAY MORNING. ONE MORE ROUND OF NOCTURNAL
PRECIPITATION THEN APPEARS POSSIBLE SATURDAY NIGHT INTO SUNDAY
MORNING AS A STRONGER LOW LEVEL JET INFILTRATES THE AREA.
LOW LEVEL MOISTURE REMAINS LESS THAN IMPRESSIVE THROUGH FRIDAY AS
SURFACE RIDGING REMAINS ENTRENCHED ACROSS THE AREA AND AS A
RESULT...INSTABILITY SUFFERS GREATLY. CONTEMPLATED TAKEN THUNDER OUT
OF THE FORECAST ALTOGETHER THURSDAY AND THURSDAY NIGHT BUT WITH THE
OPERATIONAL GFS AND EC BOTH SUGGESTING MAYBE AROUND 100J/KG DEEP
LAYER MUCAPE VALUES...WENT AHEAD WITH ISOLATED THUNDER MENTION FOR
THAT TIME BEING. LOW LEVEL MOISTURE FLUX INTO THE AREA VIA LOW LEVEL
RETURN FLOW SHOULD ALLOW FOR INCREASING INSTABILITY VALUES HEADING
INTO THE WEEKEND...WITH 1000-2000J/KG DEEP LAYER MUCAPE VALUES BEING
ADVERTISED BY THE OPERATIONAL GFS AND EC.
NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES ARE STILL EXPECTED
THURSDAY AS SURFACE RIDGING REMAINS OVER THE AREA. LOW LEVEL RETURN
FLOW WILL THEN PROMOTE A WARMING TREND...WITH TEMPERATURES CLIMBING
TO LEVELS WELL ABOVE-NORMAL FOR THIS TIME OF YEAR ACROSS OUR SOUTH
ON FRIDAY...AND ACROSS THE ENTIRE CWA SATURDAY ONWARD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
AVIATION/LONG TERM...BRYANT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
748 AM EDT MON MAY 21 2012
.SYNOPSIS...
AN UPPER LOW OVER THE SOUTHEAST COAST WILL OPEN UP AND LIFT
NORTHEAST TODAY AND TONIGHT. A DEEPENING SHORTWAVE WILL SLOW DOWN
AND CUT OFF OVR THE CENTRAL APPALACHIANS DURING THE MIDDLE OF THE
WEEK. PENNSYLVANIA WILL BE ON THE EDGE OF THE REBUILDING UPPER RIDGE
ACROSS THE OHIO VALLEY BY THE END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LOW OVER THE CAROLINA COAST WILL LIFT NORTH ALONG THE E
COAST DURING THE NEXT 24HRS. ASSOCIATED MOIST...EASTERLY LL JET AND
UPPER LVL DIVERGENCE PRECEDING THE UPPER LOW WILL BRING SHOWERS
TO MOST OF CENTRAL PA TODAY. RADAR SHOWS SCT SHOWERS HAVE ALREADY
OVERSPREAD THE LOWER SUSQ VALLEY AS OF 09Z AND LATEST RUC AND 4KM
NAM SUGGEST NORTHERN EDGE OF SHOWERS/DRIZZLE WILL REACH FROM ARND
JST TO IPT BY LATE MORNING.
CLOUD COVER...PRECIP AND EASTERLY FLOW OFF THE ATLANTIC WILL
RESULT IN MUCH COOLER TEMPS TODAY WITH MAXIMUMS ONLY ARND 70F.
BLEND OF OPER AND ENSEMBLE QPF INDICATES LIKELY RAINFALL AMTS
TODAY OF BTWN 0.1 AND 0.2 INCHES.
DOWNSLOPING SE FLOW WILL RESULT IN PARTIAL SUNSHINE AND A
SOMEWHAT WARMER MONDAY OVR WARREN COUNTY...WHERE A LATE DAY
TSRA IS POSSIBLE. OPER GFS/NAM INDICATE CAPE VALUES NR 1000JK-1
ACROSS WARREN CO BY THIS EVENING. FURTHER EAST...A COOLER MORE
STABLE EASTERLY FLOW WILL LIKELY PRECLUDE THUNDER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
SCT SHRA WILL CONTINUE TO FALL OVER CENTRAL PA TONIGHT...AS MOIST
EASTERLY LL JET AND UPPER LVL DIVERGENCE REMAIN OVR THE AREA IN
ADVANCE OF UPPER LOW. A GENERAL DECREASE IN SHOWER ACTIVITY IS
EXPECTED LATE TONIGHT AS UPPER LOW OPENS UP AND LIFTS NE. BIGGER
STORY LATE TONIGHT COULD BE AREAS OF POTENTIALLY DENSE FOG. PLENTY
OF LL MOISTURE AND A NEARLY CALM WIND WILL BE FAVORABLE FOR FOG.
AS E COAST UPPER LOW OPENS UP AND LIFTS INTO THE CANADIAN
MARITIMES...UPSTREAM SHORTWAVE WILL DEEPEN AND CUT OFF OVR THE
TENN VALLEY ON TUESDAY. LG SCALE FORCING AHEAD OF THIS FEATURE
WILL PRODUCE MORE SHRA/TSRA TUESDAY. GEFS/SREF DATA BOTH SUGGEST
BEST CHC OF SHRA/TSRA WILL BE ALONG THE SPINE OF THE APPALACHIANS.
OVERCAST SKIES AND VERY LGT WINDS ALOFT SUGGEST THERE WILL BE VERY
LITTLE THREAT OF SVR WX. BLEND OF GEFS/SREF QPF RANGES FROM 0.2 TO
0.3 INCHES TONIGHT AND TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
RELATIVELY GOOD AGREEMENT AMONG MED RANGE GUIDANCE LATER THIS
WEEK...ALL OF WHICH INDICATES UPPER LOW SLOWLY LIFTING NORTH ALONG
THE CENTRAL APPALACHIANS. THIS SCENARIO SUPPORTS THE CHC OF
DIURNALLY ENHANCED SHRA/TSRA WED-THU AND POSSIBLY EVEN FRIDAY. NEARLY
ALL MDL DATA TRACKS TS ALBERTO WELL EAST OFF THE MID ATLANTIC
COAST TUE NIGHT WITH NO DIRECT IMPACT ON PA.
TEMPS THIS WEEK LOOK TO BE ABOVE NORMAL...MAINLY DUE TO WARM
OVERNIGHT LOWS. DEEP SOUTHERLY FLOW AHEAD OF UPPER LOW WILL
TRANSPORT ABOVE NORMAL MOISTURE NORTH ALONG THE E COAST...RESULTING
IN THE WARM NIGHTS.
EVEN WARMER WX APPEARS VERY LIKELY BY NEXT WEEKEND WHEN ALL MDL
DATA INDICATES A BUILDING UPPER LVL RIDGE OVER THE OHIO VALLEY.
HOWEVER...PA MAY BE ON PERIPHERY OF THIS FEATURE...PLACING AT
LEAST NORTHERN PA IN RING OF FIRE WITH CHC OF PM CONVECTION.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AN UPPER LOW OVER THE SOUTHEAST COAST WILL OPEN UP AND LIFT
NORTHEAST TODAY AND TONIGHT...AND AN INCREASING LL JET WILL
BRING MOIST SOUTHEAST FLOW AND GENERALLY POOR FLYING CONDITIONS
TO THE REGION OVER THE NEXT SEVERAL DAYS.
INCREASING MOISTURE HAS ALREADY RESULTED IN LOWERING CIGS ACROSS
MUCH OF CENTRAL PA. IFR CIGS PREVALENT IN THE LOWER SUSQ...WITH
MVFR GRADUALLY SPREADING NW ACROSS CENTRAL MTNS. SHOWERS WILL ALSO
INCREASE FROM THE SE DURING THE DAY TODAY...WITH NORTHERN EDGE OF
SHOWERS REACHING FROM AROUND JST-UNV-IPT BY LATE MORNING.
CIGS DETERIORATE FURTHER OVERNIGHT...BECOMING IFR AS AN UPPER
LEVEL TROF APPROACHES FROM THE GREAT LAKES.
OUTLOOK...
MON NIGHT-WED...WIDESPREAD MVFR/IFR CIGS AND VSBYS LIKELY IN
SHOWERS AND SCT TSRA.
THU...PRIMARILY VFR. SCT SHRA/TSTM POSS MAINLY SE.
FRI...PRIMARILY VFR. ISOLD SHRA/TSTM POSS MAINLY SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1034 AM EDT MON MAY 21 2012
.SYNOPSIS...
TROPICAL STORM ALBERTO WILL LINGER OFF THE CAROLINA COAST TODAY
BEFORE BEGINNING TO PULL AWAY TO THE NORTHEAST ON TUESDAY. A COLD
FRONT AND AN UPPER LEVEL LOW PRESSURE SYSTEM WILL MOVE INTO THE AREA
FROM THE WEST TONIGHT THROUGH TUESDAY. THE LOW PRESSURE WILL
STEADILY LIFT NORTHEAST THROUGH MID WEEK...REPLACED BY BUILDING HIGH
PRESSURE AND UNSEASONABLY WARM TEMPERATURES LATE THIS WEEK THROUGH
THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1030 AM...VISIBLE SATELLITE PICS INDICATE MAINLY CLEAR CONDITIONS
OUTSIDE OF THE MOUNTAINS WITH SCATTERED CLOUDS OVER THE MOUNTAINS.
WITH AMPLE INSOLATION THIS MORNING...SO NO REASON TO DISCOUNT
MESOSCALE MODELS LIKE THE HRRR AND LOCAL WRF`S THAT DEVELOP
SCATTERED THUDNERSTORMS OVER THE MOUNTAINS EARLY IN THE
AFTERNOON...WITH SOME STORMS SPILLING OUT INTO THE PIEDMONT LATE
AFTERNOON INTO THE EVENING. MADE SOME MOSTLY MINOR ADJUSTMENTS TO
POP/SKY/THERMAL FIELDS FOR TODAY.
FORECAST SOUNDINGS DEPICT A VERY DEEP MIXED LAYER/STRONG LOW-MID
LEVEL LAPSE RATES THIS AFTERNOON ACROSS THE MTNS. THIS SHOULD YIELD
CAPES IN EXCESS OF 1500 J/KG ACROSS THE HIGHER TERRAIN. FREEZING
LEVELS SHOULD BE LOW ENOUGH AND DCAPE SUFFICIENTLY ADEQUATE TO
PERHAPS SUPPORT A FEW PULSE SEVERE STORMS. ADJUSTED POPS OVERNIGHT
BASED ON 12Z NAM WHICH ALLOWS CONVECTION TO END OVER THE PIEDMONT
WITH NEW DEVELOPMENT OVER THE MOUNTAINS LATE TONIGHT AS UPPER
TROUGH APPROACHES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT MONDAY...FAIRLY GOOD MODEL CONSENSUS EXISTS THAT A
DIGGING TROUGH WILL CLOSE OFF AN UPPER LEVEL LOW PRESSURE CENTER IN
OR NEAR THE SOUTHERN APPALCHIANS TUESDAY. AN ASSOCIATED SFC COLD
FRONT WILL MOVE INTO THE AREA FROM THE WEST ON TUESDAY AS WELL...BUT
WITH THE CONTRAST ALONG THE BOUNDARY SLOWLY BEING LOST THROUGH THE
DAY. NUMEROUS MTN TO SCATTERED PIEDMONT CONVECTIVE COVERAGE EARLY
SHOULD STEADILY INCREASE TO NUMEROUS COVERAGE THROUGHOUT DURING THE
AFTN AND EARLY EVENING HOURS. MODEL PROFILES SUGGEST THAT WINDS WILL
BE FAIRLY LIGHT UP THE COLUMN WITH THE PASSAGE OF THE BEST UPPER
SUPPORT. LAPSE RATES WILL STEEPEN A BIT...BUT WITH THE COLDEST POOL
OF 500 MB TEMPS ALOFT PASSING BY JUST SE OF THE AREA. THE SEVERE
WEATHER POTENTIAL...THEREFORE...IS NOT TERRIBLY IMPRESSIVE.
THE UPPER LOW CENTER WILL LIFT SLOWLY NORTHEASTWARD TUE NIGHT
THROUGH WED AND GRADUALLY FILL. LOW LEVEL FLOW WILL RETURN TO
SOUTHERLY AND BOUNDARY LAYER MOISTURE SHOULD LINGER ENOUGH TO PERMIT
SCATTERED CONVECTIVE COVERAGE TO RETURN WED AFTN AND EVENING.
TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE
PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 AM EDT MONDAY...AS THE FILLING LOW PRES SYSTEM PULLS AWAY
TO THE NE ON THU...LOW LEVEL SW FLOW WILL PERSIST ACROSS THE REGION
AND HEIGHTS WILL START RISING ALOFT. TEMPERATURES SHOULD WARM INTO
THE MID 80S MOST LOCATIONS OUTSIDE OF THE MTNS THU AFTN...WITH SOME
LOWER 80S IN THE LOWER MTN VALLEYS. ISOLATED...MAINLY MTN...DIURNAL
POPS ARE INDICATED IN THE WARM AIRMASS. DOMINANT RIDGING WILL THEN
START BUILDING OVER THE ERN CONUS ON FRI...WITH TEMPERATURES GAINING
ANOTHER CATEGORY BY FRIDAY AFTN. VERY LITTLE CAPE IS EVIDENT IN THE
WARM PROFILES ALOFT...BUT LINGERING BL MOISTURE WILL WARRANT A
SLIGHT CHC TSTM MENTION ALONG THE HIGHER TERRAIN FRI AFTN/EVENING.
STRONG HIGH PRESSURE WILL COME TO DOMINATE THE ENTIRE ERN CONUS BY
SAT...WITH MAXES AS MUCH AS 10 DEGREES ABOVE NORMAL. ISOLD TO SCT
RIDGE TOP CONVECTION WILL ONCE AGAIN BE POSSIBLE LATE IN THE DAY.
850 MB TEMPS MAY THEN COOL VERY SLIGHTLY ON SUNDAY AS THE RIDGE
RETROGRADES WEST...BUT TEMPS WILL STAY WELL ABOVE AVERAGE. ANOTHER
ROUND OF ISOLATED DIURNALLY DRIVEN MOUNTAIN CONVECTION WILL BE
POSSIBLE UNDER THE RIDGE SUNDAY AFTN. CONVECTIVE INITIATION MAY
FOCUS SLIGHTLY MORE TOWARD THE ERN SLOPES IF AN EASTERLY COMPONENT
IN THE BOUNDARY LAYER FLOW DEVELOPS UNDER THE RIDGE AS EXPECTED.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...MVFR STRATOCU OVER CENTRAL NC MAY MAKE A RUN
AT KCLT THIS MORNING...BUT CONFIDENCE IS LOW THAT THIS WILL OCCUR...
AND IT SHOULD BE BRIEF IF IT DOES OCCUR. OTHERWISE...ALL TERMINALS
WILL SEE VFR CONDITIONS THROUGH AT LEAST THIS EVENING...BARRING ANY
CONVECTIVE OCCURRENCE. SPEAKING OF WHICH...SCATTERED CONVECTION WILL
DEVELOP OVER THE MOUNTAINS THIS AFTERNOON...AND A TEMPO WILL BE
INCLUDED AT KAVL EARLY THIS AFTERNOON...FOLLOWED BY A PROB30 FOR THE
REMAINDER OF THE AFTERNOON AND EARLY EVENING. ISOLATED TO WIDELY
SCATTERED CONVECTION MAY EXTEND INTO THE PIEDMONT AND FOOTHILLS LATE
THIS AFTERNOON AND EVENING. A PROB 30 WILL BE CARRIED AT KHKY TO
ACCOUNT FOR THIS. ANY FOG/CIG RESTRICTIONS LATE TONIGHT WILL DEPEND
LARGELY UPON RAIN OCCURRENCE AT THE TERMINALS THIS AFTERNOON/
EVENING. OTHER THAN MVFR FOG AT KAVL...RESTRICTIONS WILL BE WITHHELD
FROM THE FORECASTS ATTM.
OUTLOOK...DIURNAL SHOWER AND TSTM CHANCES WILL INCREASE TUESDAY AS A
WEAK COLD FRONT ARRIVES FROM THE WEST. AN UPPER LOW IS EXPECTED TO
DEVELOP OVER THE CAROLINAS BY MID-WEEK...AND THIS WILL KEEP CHANCES
FOR AT LEAST ISOLATED SHOWERS AND THUNDERSTORMS IN THE FORECAST FOR
MOST AFTERNOONS/EVENING THROUGH THE WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...HG
NEAR TERM...LG
SHORT TERM...HG
LONG TERM...HG
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1105 AM CDT MON MAY 21 2012
.PREV DISCUSSION...
345 AM CDT
08Z SURFACE ANALYSIS DEPICTS LOW PRESSURE NORTHEAST OF THE LAKES
ACROSS EASTERN ONTARIO...WITH ITS COLD FRONT TRAILING THROUGH
INDIANA AND INTO THE BOOTHEEL OF MISSOURI. RAIN CONTINUES TO WEAKEN
AND ERODE THROUGH THE FRONTAL ZONE...WITH JUST A FEW SCATTERED
SHOWERS LINGERING ACROSS THE IL/IND STATE LINE INTO NORTHWEST
INDIANA AT THIS TIME. SHORT TERM HIGH-RES GUIDANCE INDICATES PRECIP
WILL CONTINUE TO WEAKEN AND DRIFT OFF TO THE EAST EARLY THIS MORNING
WITH CLOUDS ALSO SLOWLY MOVING EAST. THUS WILL START OF THE FORECAST
WITH A LOW POP ACROSS NORTHWEST INDIANA FOR LINGERING EARLY SHOWERS
AND WILL HAVE MOSTLY CLOUDY THIS AM/BECOMING MOSTLY SUNNY LATER FOR
MOST AREAS. AFTER HIGHS IN THE LOWER 90S AGAIN SUNDAY...TODAY WILL
BE MUCH COOLER WITH TEMPS A GOOD 20-25 DEGREES LOWER. WINDS TURNING
NORTH-NORTHEAST LATER THIS MORNING SHOULD LIMIT AREAS ALONG THE LAKE
TO THE LOW-MID 60S...WITH LOWER 70S ACROSS THE FAR WESTERN CWA.
AN ELONGATED AREA OF SURFACE HIGH PRESSURE WILL SPREAD SLOWLY
EAST-SOUTHEAST FROM THE UPPER MIDWEST ACROSS THE WESTERN GREAT LAKES
THROUGH TUESDAY...PROVIDING DRY/PLEASANT WEATHER WITH COOL
NIGHTTIME TEMPS IN THE MID 40S-LOWER 50S...AND DAYTIME HIGHS IN THE
LOW-MID 70S WITH 60S AGAIN ALONG THE LAKE. SOUTH-SOUTHEAST WINDS
WILL STRENGTHEN TUESDAY NIGHT INTO WEDNESDAY AS THE SURFACE RIDGE
MOVES OFF TO THE EAST AND AN AREA OF LOW PRESSURE LIFTS NORTHEAST
ACROSS THE NORTHERN PLAINS. BREEZY WARM ADVECTION WILL PUSH TEMPS
BACK INTO THE UPPER 70S/LOW 80S WEDNESDAY AND INTO THE MID-UPPER 80S
THURSDAY AS BROAD UPPER TROUGH DEVELOPS OVER THE WESTERN CONUS AND
DEVELOPS DEEP SOUTH-SOUTHWEST FLOW ALOFT. BOTH DAYS WILL FEATURE
SOME MODEST LAKE COOLING ALONG THE NORTH SHORE...AS SFC WINDS
MAINTAIN A SOUTHEASTERLY COMPONENT.
LONGER RANGE MODELS ARE IN GOOD AGREEMENT IN DEPICTING A FAIRLY
STOUT SHORT WAVE TROUGH AND ASSOCIATED SURFACE LOW WHICH EMERGE FROM
THE WESTERN TROUGH AND LIFT ACROSS THE UPPER MIDWEST/NORTHERN LAKES
IN THE LATE THURSDAY/FRIDAY PERIOD...AND EVENTUALLY TRAIL A COLD
FRONT INTO THE FORECAST AREA FRIDAY. THERE ARE SOME DIFFERENCES AS
TO HOW QUICKLY THIS OCCURS AND JUST HOW FAR SOUTH THE FRONT SETTLES
BEFORE STALLING OUT FRIDAY NIGHT/SATURDAY. OVERALL HAVE BASED
FORECAST ON SLIGHTLY SLOWER ECMWF RATHER THAN FASTER GFS SOLUTION
AND THUS HAVE GENERALLY LOW CHANCE POPS THURSDAY NIGHT/FRIDAY ACROSS
THE NORTHERN PORTIONS OF THE FORECAST AREA...AND COOLER TEMPS MAINLY
FAR NORTH/ALONG THE LAKE FRIDAY. SATURDAY FEATURES A RELATIVELY
LARGE THERMAL SPREAD WITH NORTHEAST FLOW OFF THE LAKE WITH FRONT
STALLED OUT ACROSS CENTRAL IL/IND...WITH TEMPS RANGING FROM NEAR 90
FAR SOUTH CLOSE TO THE BOUNDARY TO THE MID 60S RIGHT AT THE LAKE
SHORE.
UPPER RIDGE THEN BEGINS TO BUILD ALOFT AS LOW LEVEL FRONT STALLS
OUT...WITH FORECAST SOUNDINGS INDICATING RELATIVELY STRONG CAPPING
WITH WARMING TEMPS ALOFT. FOR THIS REASON HAVE FOLLOWED THE DRIER
ECMWF WITH RESPECT TO PRECIP/LACK THEREOF IN THE SATURDAY/SUNDAY
PERIOD. WARM FRONT THEN LIFTS BACK NORTH/NORTHEAST SUNDAY...THOUGH
MODELS DIFFER IN JUST HOW QUICKLY THIS OCCURS. WITH SOMEWHAT LOW
CONFIDENCE AT THIS GREAT DISTANCE HAVE USED A BLEND OF ECMWF-GFS
FRONTAL POSITION SUNDAY WHICH RESULTS IN KEEPING A SOUTHEASTERLY
COMPONENT TO SFC WINDS ALONG NORTH SHORE ONCE AGAIN. WARM LOW LEVEL
THERMAL FIELDS SUPPORT UPPER 80S/LOW 90S...WITH COOLER TEMPS ALONG
THE IL LAKE SHORE.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* GUSTY NORTHWEST WINDS
* MORNING MVFR CIGS
ZEBIC
//DISCUSSION...UPDATED 12Z...
SURFACE COLD FRONT CONTINUES TO SHIFT THROUGH THE REGION THIS
EVENING...ENDING PRECIP AND FLIPPING TO WINDS AROUND TO THE
NORTH. MVFR CIGS ARE NOTED ACROSS MOST OF THE TRACON THIS
MORNING...AND NOT EXPECTING ANYTING TO FALL LOWER THAN THE 023 TO
025 RANGE. DRY AIR IS QUICKLY ADVANCING...AND DESPITE A SUBSIDENCE
INVERSION...SHOULD SEE THESE QUICKLY BREAK UP THIS MORNING IN THE
14 TO 15Z HOUR. WINDS ARE PROGGED TO REMAIN NORTHERLY AND FLOP TO
THE NORTHEAST. CLIMATOLOGICALLY SPEAKING...WINDS TYPICALLY WONT
STAY OUT OF THE NORTH...BUT SHIFT EAST OF NORTH. NOT THE MOST
CONFIDENT IT WILL HAPPEN AT 15Z...BUT MORE CONFIDENT WITH WINDS
TURNING TOWARDS 040 BY 20Z. LATEST RAP AND HRRR DATA ARE
INDICATING HIGHER WIND GUSTS AND SUSPECT THAT ORD WILL SEE LOW 20
KT GUSTS THIS AFTERNOON WHILE GYY IS FLIRTING WITH 30 KT.
SHEA
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MODERATE TO HIGH CONFIDENCE ON CIG FORECAST
* HIGH CONFIDENCE IN WIND FORECAST
* HIGH CONFIDENCE IN DRY FORECAST
ZEBIC
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
WEDNESDAY...VFR.
THURSDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA LATE.
FRIDAY...VFR. SLIGHT CHANCE OF SHRA/TSRA.
SATURDAY AND SUNDAY...VFR.
SHEA
&&
.MARINE...
334 AM CDT
LOW PRESSURE CONTINUES TO LIFT INTO ONTARIO THIS MORNING...AND A
COLD FRONT MOVED THROUGH. SHOWERS AND THUNDERSTORMS HAVE COME TO
AN END AND SURFACE HIGH PRESSURE WILL BE SWINGING OVERHEAD. THE
PRESSURE GRADIENT WILL REMAIN HIGH THROUGH THE MORNING HOURS AND
ALLOW WIND GUSTS TO APPROACH 25 KT FOR MOST OF THE INDIANA
NEARSHORE WATERS. NOT FULLY CONFIDENT THAT THE ILLINOIS ZONES WILL
BE SPARED AND WILL INCLUDE LMZ742 /NORTHERLY ISLAND/ THROUGH
MICHIGAN CITY. WINDS WILL ABATE THIS AFTERNOON BUT WAVES ARE
EXPECTED TO REMAIN ABOVE CRITERIA THROUGH TOMORROW MORNING. HIGH
PRESSURE WILL THEN DOMINATE THE PATTERN THROUGH MID WEEK...BEFORE
STRONG SOUTHERLY FLOW RETURNS.
SHEA
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 10 AM
TUESDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO NORTHERLY IS UNTIL 11 PM MONDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1259 PM EDT MON MAY 21 2012
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 338 AM EDT MON MAY 21 2012
SCATTERED SHOWERS AND THUNDERSTORMS WILL GRADUALLY SHIFT EAST TODAY
WITH A WEAK COLD FRONT...WITH DRY WEATHER RETURNING TONIGHT AS HIGH
PRESSURE REESTABLISHES OVER THE REGION. AFTER A BRIEF COOLDOWN FOR
TODAY AND TUESDAY...ARRIVAL OF RIDGING ALOFT AND SOUTHERLY FLOW WILL
BRING A WARMING TREND BEGINNING ON WEDNESDAY. THE UPPER RIDGE WILL
BECOME THE DOMINANT WEATHER FEATURE FOR THE OHIO VALLEY FOR LATE
WEEK AND THE UPCOMING HOLIDAY WEEKEND...WITH DRY WEATHER AND THE
HOTTEST TEMPERATURES OF THE YEAR SO FAR.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 922 AM EDT MON MAY 21 2012
ANALYSIS AS OF 915AM THIS MORNING DEPICTS A SURFACE COLD FRONT
MOVING ACROSS THE WESTERN COUNTIES OF THE CWA EARLY THIS MORNING...
THE PASSAGE OF THE FRONT WILL USHER IN MUCH DRIER AIR AND A SHIFT
TO NORTHWEST WINDS AS IT PROGRESSES EAST THROUGH THE FORECAST AREA
DURING THE COURSE OF THE DAY. CONVECTIVE COVERAGE CONTINUES TO
DIMINISH EARLY THIS MORNING AS INSTABILITY WANES AND FORCING ALOFT
IS LIMITED. CURRENT RAP INDICATING THAT CONVECTIVE COVERAGE WILL
DECREASE OVER THE NEXT FEW HOURS...WITH RENEWED DEVELOPMENT MAINLY
ALONG AND AHEAD OF THE INSTABILITY GRADIENT AND FRONTAL BOUNDARY
BY MID/LATE MORNING OVER THE EASTERN HALF OF THE FORECAST AREA.
HAVE FOCUSED HIGHEST POPS SOUTH AND EAST OF THE INDY METRO WHERE
COMBINATION OF THE INSTABILITY AND DEEPEST MOISTURE AXIS SHOULD
PROMOTE LARGELY DISORGANIZED AND SCATTERED CONVECTION INTO THE
AFTERNOON.
WILL MAINTAIN LOW CHANCE POPS OVER WESTERN COUNTIES THIS MORNING TO
ACCOUNT FOR ANY ISOLATED DEVELOPMENT ALONG THE FRONT AS IT MOVES
INTO THE AREA. HOWEVER...EXPECT AN OVERALL DRYING TREND FOR THE
AFTERNOON AS MODEL GUIDANCE IN AGREEMENT ON MUCH DRIER AIR ADVECTING
INTO THE REGION FROM THE WEST WITH A CAPPING INVERSION BECOMING WELL
ESTABLISHED BY LATE DAY. AXIS OF DEEPER MOISTURE WILL SHIFT EAST
INTO OHIO BY EARLY EVENING WITH ANY LINGERING PRECIP DEPARTING THE
FORECAST AREA.
TEMPS...COOLER DAY SETTING UP AS COLD ADVECTION COMMENCES WITH THE
FRONTAL PASSAGE. CONSALL AND MAVMOS GUIDANCE MATCHED UP WELL WITH
LOW LEVEL THERMALS WITH MOST LOCATIONS REMAINING IN THE 70S THIS
AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 338 AM EDT MON MAY 21 2012
FORECAST CHALLENGES FOCUS ON TEMPS THROUGH THE PERIOD AS A WARMING
TREND COMMENCES BY WEDNESDAY WITH THE RETURN OF RIDGING ALOFT.
UPPER TROUGH WILL SHARPEN AS IT PASSES THE FORECAST AREA TONIGHT...
EVENTUALLY DEVELOPING AN UPPER LOW THAT WILL DIVE INTO THE SOUTHEAST
STATES BY TUESDAY NIGHT. THIS WILL CAUSE DEEPER MOISTURE TO HOLD
OVER THE EASTERN OHIO VALLEY AND THE SOUTHERN APPALACHIANS INTO
WEDNESDAY AS THE UPPER LOW SLOWLY PINWHEELS EAST INTO THE CAROLINAS.
THE ONLY IMPACTS TO CENTRAL INDIANA WILL BE TO ACCENTUATE CLOUD
COVER INTO TUESDAY OVER EASTERN COUNTIES WHERE PRESENCE OF A LOW
LEVEL THERMAL TROUGH LIKELY TO ENABLE A HEALTHY CU FIELD ON THE BACK
SIDE OF THE MOISTURE PLUME. FURTHER WEST ACROSS THE FORECAST AREA...
INCREASINGLY DEEPER SUBSIDENCE WILL FUNNEL INTO THE REGION WITH
MOSTLY SUNNY SKIES EXPECTED.
RIDGING ALOFT WILL STEADILY EXPAND INTO THE REGION TUESDAY NIGHT AND
WEDNESDAY AS THE UPPER LOW MOVES EAST ACROSS THE SOUTHERN
APPALACHIANS. PROGRESSIVELY DEEPER SUBSIDENCE WILL EXPAND ACROSS THE
OHIO VALLEY ON WEDNESDAY AS RETURN SOUTHERLY FLOW SIGNALS THE
ARRIVAL OF WARM ADVECTION. RESULT WILL BE MAINLY CLEAR SKIES
WEDNESDAY AND WEDNESDAY NIGHT AND THE BEGINNING OF A WARMUP THAT
WILL CONTINUE THROUGH THE REST OF THE WEEK.
TEMPS...MOS GUIDANCE AND CONSALL MATCHED UP WELL ON TUESDAY WITH
TEMPERATURES MAINLY IN THE MID 70S. LEANED CLOSER TO WARMER MAVMOS
WEDNESDAY AS HIGHS RETURN TO THE 80S. POTENTIAL FOR TEMPS TO SLIP
INTO THE UPPER 40S BOTH TONIGHT AND TUESDAY NIGHT IN RURAL LOCALES
WITH 50S ELSEWHERE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 338 AM EDT MON MAY 21 2012
MODELS STILL DIFFER IN THE EXTENDED ON HOW FAR SOUTH A COLD FRONT
GETS INTO THE AREA FRIDAY AND SATURDAY. GFS IS THE OUTLIER AGAIN IN
BRINGING IN THE COLD FRONT FARTHER SOUTH. EVEN GFS ENSEMBLE MEAN
KEEPS FRONT TO THE NORTH...AND EXPERIMENTAL GFS ENSEMBLE CONFIDENCE
PLOTS SHOW LOW TO VERY LOW CONFIDENCE IN GFS TEMPERATURES BY NEXT
WEEKEND. THUS WILL THROW OUT GFS AND GO CLOSER TO ECMWF AGAIN WITH
THIS PACKAGE.
THE ABOVE MEANS RAISING ALLBLEND TEMPERATURES NEXT WEEKEND AND
REMOVING ANY CHANCES FOR RAIN THAT IT GIVES. ALSO ADJUSTED ALLBLEND
DEWPOINTS AND SKY COVER AS NECESSARY.
UPPER HIGH WILL MOVE INTO THE AREA LATE IN THE WEEK AND PERSIST INTO
THE WEEKEND. THIS WILL RESULT IN HOT CONDITIONS FOR THE HOLIDAY
WEEKEND WITH NO RAIN EXPECTED. DEWPOINTS AND THUS RESULTANT HEAT
INDEX VALUES ARE MORE UNCERTAIN DUE TO LACK OF WIDESPREAD
SIGNIFICANT RAINFALL RECENTLY. CONDITIONS WILL STILL BE VERY WARM
REGARDLESS SO WILL CONTINUE TO MENTION HEAT IN HWO.
&&
.AVIATION /DISCUSSION FOR THE 211800Z TAFS ISSUANCE/...
ISSUED AT 1259 PM EDT MON MAY 21 2012
COLD FRONT CURRENTLY OVER EASTERN CENTRAL AND SOUTHERN INDIANA WILL
WILL CONTINUE MOVING EAST. AREAS OF MVFR CEILINGS HAVE DEVELOPED
BEHIND COLD FRONT AND WAS CURRENTLY LIMITING CEILINGS ALL EXCEPT
KIND.
WITH SOME DAYTIME HEATING...EXPECT CEILINGS TO RISE TO VFR CATEGORY
IN A FEW HOURS. BUT CEILINGS MAY REMAIN BARELY ABOVE 3 THOUSAND FEET
AS THERE IS AN EXTENSIVE AREA OF CU UPSTREAM ACROSS EASTERN
ILLINOIS.
DRIER AIR WILL SPREAD INTO WESTERN SECTIONS BY EVENING AND OVER MOST
OF THE REMAINING AREA LATER TONIGHT. EXPECT CLOUDS TO SCATTER OUT
MOST AREAS BY EVENING AND EVEN BECOME CLEAR AT KHUF AND KLAF BY
MIDNIGHT. MODELS KEEP SOME LOW LEVEL MOISTURE ACROSS THE SOUTHEAST
HALF OF INDIANA INDIANA INTO TUESDAY...SO ANY CLEARING AT KIND AND
KBMG MAY NOT OCCUR UNTIL NEAR OR AFTER THE END OF THE FORECAST
PERIOD.
NORTH TO NORTHWEST WINDS WILL INCREASE TO 10 TO 15 KNOTS THIS
AFTERNOON AND DROP TO 8 KNOTS OR LESS TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/SMF
SHORT TERM...RYAN
LONG TERM....50
AVIATION...JH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
237 PM MDT MON MAY 21 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 121 PM MDT MON MAY 21 2012
16Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED BROAD RIDGING IN
PLACE ACROSS THE CENTRAL ROCKIES AND ADJACENT HIGH PLAINS...WITH
TROUGH APPROACHING THE PACIFIC NORTHWEST. AT THE SFC...TROUGH WAS IN
PLACE ACROSS CENTRAL AND EASTERN COLORADO ...ROUGHLY BETWEEN KDNR
AND KAKO. TO THE EAST OF THIS TROUGH...MOISTURE ADVECTION WAS
INCREASING WITH AN AREA OF DEWPOINTS AT OR ABOVE 50 F FROM KLIC
SOUTHEAST INTO THE OKLAHOMA PANHANDLE. 12Z RAOBS AT DNR AND DDC
INDICATED AREA OF STEEP MID LEVEL LAPSE RATES BETWEEN H7 AND
H6...WITH A MUCH DEEPER LAYER NOTED AT DNR.
MAIN CONCERN FOR THE SHORT TERM PERIODS WILL BE CONVECTIVE
INITIATION CHANCES TODAY AND TEMPS/RH/FIRE WX TOMORROW.
REST OF THE AFTERNOON-TONIGHT...WITH AFOREMENTIONED MOISTURE
ADVECTION ALREADY ONGOING PER SFC OBS...AND NOSE OF STEEP MID LEVEL
LAPSE RATES IN PLACE ALONG SFC TROUGH ACROSS EASTERN COLORADO
CONFIDENCE INCREASING IN CONVECTIVE INITIATION ALONG SFC TROUGH THIS
AFTERNOON...ESPECIALLY GIVEN THAT MIXED LAYER TDS ARE VERY SIMILAR
TO FORECAST SFC VALUES INDICATING SOME DEPTH TO THE MOISTURE
PROFILE. WHILE CONFIDENCE IN DEVELOPMENT OF THUNDERSTORMS IS
HIGHER...HIGHER RES MODELS KEEPING COVERAGE FAIRLY SPARSE AND WITH
LATEST HRRR JUMPING AROUND QUITE A BIT WITH TIMING AND LOCATION...DO
NOT THINK POPS ABOVE THE 20-30 PERCENT RANGE WARRANTED JUST YET.
WITH A LOT OF UNCERTAINTY IN THE DETAILS...HAVE GENERALLY WENT WITH
BROADER COVERAGE OF POPS STARTING FIRST AROUND SFC TROUGH AROUND 20Z
AND GRADUALLY SHIFTING EAST AND DIMINISHING. SOME ELEVATED
INSTABILITY REMAINS THROUGH THE NIGHT WITH SOME WEAK ASCENT EXPECTED
TO THE WEST OF H7 THERMAL RIDGE. PROBABILISTIC GUIDANCE NOT REALLY
SUPPORTING MUCH OF A PRECIP THREAT AT THIS POINT...BUT CANNOT
TOTALLY RULE OUT SOME ELEVATED OVERNIGHT STORMS AND WILL GENERALLY
KEEP PREVIOUS FORECAST IN THIS REGARD. GIVEN ALREADY OBSERVED
MOISTURE TRANSPORT...DO HAVE SOME CONCERNS ABOUT THE DEVELOPMENT OF
FOG OVERNIGHT. WINDS SHOULD GENERALLY STAY UP WHICH WILL MINIMIZE
THE THREAT SOME WHAT...BUT GIVEN EXPECTED MOISTURE PROFILE AND SREF
INDICATING A SMALL THREAT FOR FOG THINK AT LEAST A PATCHY MENTION IS
IN ORDER.
TUESDAY...H5 RIDGE AXIS WILL SHIFT TO THE EAST THROUGH THE
DAY...WITH CWA UNDER THE INFLUENCE OF LARGE SCALE FORCING FOR
SUBSIDENCE THROUGH MUCH OF THE DAY. WHILE SYNOPTIC SCALE SUPPORT IS
LACKING...FAIRLY STRONG AND PERSISTENT CONVERGENCE EXPECTED ALONG
DRYLINE THAT WILL DEVELOP ACROSS AREA DURING THE AFTERNOON. COULD
POTENTIALLY SEE A STORM OR TWO DEVELOP IN THIS AREA...BUT GIVEN
LARGE SCALE PATTERN...POTENTIAL FOR A STRONG CAP AND VERY LOW
PROBABILITIES FROM THE NORMALLY WET SREF DATABASE...CONFIDENCE NOT
HIGH ENOUGH TO INCLUDE THUNDERSTORM THREAT AT THIS TIME. MIXED LAYER
TEMPS STILL SUPPORT TEMPS IN THE 90S ACROSS MUCH OF THE
AREA...ALTHOUGH THERE DOES APPEAR TO BE SOME DISCREPANCIES FOR HOW
WARM THINGS WILL GET WITH SREF INDICATING A RANGE BETWEEN 97 AND
AROUND 88 FOR GLD. GIVEN OVERALL PATTERN AND POTENTIAL TO BE ON MUCH
DRIER SIDE OF THE DRYLINE THINK WARMER SOLUTIONS THE WAY TO AND MADE
ONLY MINOR CHANGES TO GOING FORECAST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 236 PM MDT MON MAY 21 2012
A COLD FRONT WILL DROP SOUTH TOWARDS OUR CWA TUESDAY NIGHT AS A
SHORTWAVE TROUGH MOVES ACROSS THE NORTHERN PLAINS. WITH AIRMASS OVER
CWA GENERALLY STABILIZING TUESDAY EVENING THUNDERSTORM CHANCES
REMAIN MINIMAL AND WILL BE TIED MAINLY TO WHAT DEVELOPS DURING THE
AFTERNOON. MODEL DIFFERENCES IN THE TIMING/POSITION OF THE FRONT
WILL HAVE A LARGER IMPACT ON THE TEMPERATURE FORECAST WEDNESDAY WHEN
IT WILL STALL OVER THE CWA AND THEN LIFT NORTH AS A WARM FRONT.
ECMWF AND GFS TEND TO BE THE QUICKEST IN DEVELOPING A STRONG LEE
TROUGH OVER EASTERN COLORADO...PUSHING THE FRONT NORTH BY MIDDAY.
CURRENT HIGH TEMP FORECAST FOR WEDNESDAY REFLECTS A BLEND OF
SOLUTIONS WITH UPPER 90S OVER SW PART OF THE CWA...AND UPPER 70S IN
THE NORTHWEST. WERE THE FRONT TO LIFT QUICKER...MID-UPPER 90S COULD
BE EXPECTED ACROSS A MUCH LARGER PART OF THE CWA. WITH THE SURFACE
TROUGH EXPECTED TO BE OVER THE CWA BY MIDDAY...STRONGEST SURFACE
GRADIENT SHOULD REMAIN EAST...SO WINDS SHOULD REMAIN BELOW RED FLAG
CRITERIA.
LARGE SCALE TROUGH DEVELOPS OVER THE GREAT BASIN/NORTHERN ROCKIES BY
WEDNESDAY AFTERNOON...WITH A SERIES OF WEAK SHORTWAVE TROUGH MOVING
JUST NORTH AND WEST OF THE CWA THROUGH NEXT WEEKEND. THE FIRST
SHORTWAVE ARRIVES BY WEDNESDAY NIGHT...WITH THUNDERSTORMS POSSIBLY
INITIATING OVER NORTHEAST COLORADO. BEST CHANCES WILL BE ACROSS THE
NORTH AFTER MIDNIGHT WEDNESDAY NIGHT WHEN A COLD FRONT WILL MOVE
INTO SOUTHWEST NEBRASKA AND STALL. I HAVE LESS CONFIDENCE FURTHER
SOUTH AND EAST...HOWEVER WITH AT LEAST SOME GUIDANCE SHOWING
DEVELOPMENT TOWARDS THE I-70 CORRIDOR...I FELT COMFORTABLE KEEPING
SLIGHT CHANCE/CHANCE POPS IN PLACE.
BY THURSDAY THIS INITIAL SHORTWAVE WILL MOVE TO THE EAST WITH
SUBSIDENCE BUILDING IN OVER THE CWA IN IT WAKE. AT THE SAME TIME
ANOTHER WEAK DISTURBANCE WILL BE MOVING IN FROM THE WEST BY THURSDAY
AFTERNOON/NIGHT...WITH POPS INCREASING ONCE AGAIN FROM THE
WEST...AND CHANCES LIMITED TO NORTH OF INTERSTATE 70.
FRIDAY-MONDAY...LARGE SCALE TROUGH REMAINS IN PLACE ACROSS THE
WESTERN CONUS...EVENTUALLY BREAKING DOWN AND TRANSITIONING TO A
WESTERLY ZONAL PATTERN BY EARLY NEXT WEEK. RESULT WILL BE A FAIRLY
ACTIVE PATTERN...WITH STORM TRACK FAVORING NORTHERN PORTIONS OF OUR
CWA FOR SHOWER/THUNDERSTORM CHANCES. CONFIDENCE WAS TOO LOW TO RAISE
POPS BEYOND 20/30 RANGE...CONSIDERING DIFFERENCE IN TIMING OF THESE
FEATURES...AND DIFFERENCES IN POSITION OF SURFACE FEATURES AS
HANDLED BY GUIDANCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1132 AM MDT MON MAY 21 2012
VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS AT BOTH LOCATIONS AS
DEVELOPING SFC TROUGH WILL KEEP WINDS OUT OF THE SOUTH IN THE 15
TO 20 KT RANGE THROUGH THE BULK OF THE PERIOD ALTHOUGH WINDS
SHOULD DIE DOWN A BIT IN THE OVERNIGHT HOURS. POTENTIAL FOR
ISOLATED THUNDERSTORMS BTWN 22 AND 2Z MAINLY AT GLD AS STORMS FORM
ALONG SFC TROUGH AND DRIFT EAST...BUT PROBABILITIES TOO LOW TO
INCLUDE IN TAFS ATTM.
&&
.FIRE WEATHER...
ISSUED AT 121 PM MDT MON MAY 21 2012
VERY WARM AND DRY WEATHER IS EXPECTED ACROSS MUCH OF THE AREA ON
TUESDAY...WITH AFTERNOON HUMIDITIES BELOW 15 PERCENT EXPECTED
ALONG AND EAST OF THE COLORADO AND KANSAS STATE LINE. WESTERLY
WINDS WILL GRADUALLY INCREASE IN THIS AREA TO AROUND 15 MPH IN THE
AFTERNOON. WITH RECENT RAINFALL AND WINDS NOT EXPECTED TO INCREASE
TO LATE IN THE AFTERNOON...OVERALL CONFIDENCE IN CRITICAL FIRE
WEATHER CONDITIONS IS TOO LOW TO WARRANT A WATCH OR WARNING AT
THIS POINT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...DR
AVIATION...JRM
FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
125 PM MDT MON MAY 21 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 121 PM MDT MON MAY 21 2012
16Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED BROAD RIDGING IN
PLACE ACROSS THE CENTRAL ROCKIES AND ADJACENT HIGH PLAINS...WITH
TROUGH APPROACHING THE PACIFIC NORTHWEST. AT THE SFC...TROUGH WAS IN
PLACE ACROSS CENTRAL AND EASTERN COLORADO ...ROUGHLY BETWEEN KDNR
AND KAKO. TO THE EAST OF THIS TROUGH...MOISTURE ADVECTION WAS
INCREASING WITH AN AREA OF DEWPOINTS AT OR ABOVE 50 F FROM KLIC
SOUTHEAST INTO THE OKLAHOMA PANHANDLE. 12Z RAOBS AT DNR AND DDC
INDICATED AREA OF STEEP MID LEVEL LAPSE RATES BETWEEN H7 AND
H6...WITH A MUCH DEEPER LAYER NOTED AT DNR.
MAIN CONCERN FOR THE SHORT TERM PERIODS WILL BE CONVECTIVE INITIATION
CHANCES TODAY AND TEMPS/RH/FIRE WX TOMORROW.
REST OF THE AFTERNOON-TONIGHT...WITH AFOREMENTIONED MOISTURE
ADVECTION ALREADY ONGOING PER SFC OBS...AND NOSE OF STEEP MID LEVEL
LAPSE RATES IN PLACE ALONG SFC TROUGH ACROSS EASTERN COLORADO
CONFIDENCE INCREASING IN CONVECTIVE INITIATION ALONG SFC TROUGH THIS
AFTERNOON...ESPECIALLY GIVEN THAT MIXED LAYER TDS ARE VERY SIMILAR
TO FORECAST SFC VALUES INDICATING SOME DEPTH TO THE MOISTURE
PROFILE. WHILE CONFIDENCE IN DEVELOPMENT OF THUNDERSTORMS IS
HIGHER...HIGHER RES MODELS KEEPING COVERAGE FAIRLY SPARSE AND WITH
LATEST HRRR JUMPING AROUND QUITE A BIT WITH TIMING AND LOCATION...DO
NOT THINK POPS ABOVE THE 20-30 PERCENT RANGE WARRANTED JUST YET.
WITH A LOT OF UNCERTAINTY IN THE DETAILS...HAVE GENERALLY WENT WITH
BROADER COVERAGE OF POPS STARTING FIRST AROUND SFC TROUGH AROUND 20Z
AND GRADUALLY SHIFTING EAST AND DIMINISHING. SOME ELEVATED
INSTABILITY REMAINS THROUGH THE NIGHT WITH SOME WEAK ASCENT EXPECTED
TO THE WEST OF H7 THERMAL RIDGE. PROBABILISTIC GUIDANCE NOT REALLY
SUPPORTING MUCH OF A PRECIP THREAT AT THIS POINT...BUT CANNOT
TOTALLY RULE OUT SOME ELEVATED OVERNIGHT STORMS AND WILL GENERALLY
KEEP PREVIOUS FORECAST IN THIS REGARD. GIVEN ALREADY OBSERVED
MOISTURE TRANSPORT...DO HAVE SOME CONCERNS ABOUT THE DEVELOPMENT OF
FOG OVERNIGHT. WINDS SHOULD GENERALLY STAY UP WHICH WILL MINIMIZE
THE THREAT SOME WHAT...BUT GIVEN EXPECTED MOISTURE PROFILE AND SREF
INDICATING A SMALL THREAT FOR FOG THINK AT LEAST A PATCHY MENTION IS
IN ORDER.
TUESDAY...H5 RIDGE AXIS WILL SHIFT TO THE EAST THROUGH THE
DAY...WITH CWA UNDER THE INFLUENCE OF LARGE SCALE FORCING FOR
SUBSIDENCE THROUGH MUCH OF THE DAY. WHILE SYNOPTIC SCALE SUPPORT IS
LACKING...FAIRLY STRONG AND PERSISTENT CONVERGENCE EXPECTED ALONG
DRYLINE THAT WILL DEVELOP ACROSS AREA DURING THE AFTERNOON. COULD
POTENTIALLY SEE A STORM OR TWO DEVELOP IN THIS AREA...BUT GIVEN
LARGE SCALE PATTERN...POTENTIAL FOR A STRONG CAP AND VERY LOW
PROBABILITIES FROM THE NORMALLY WET SREF DATABASE...CONFIDENCE NOT
HIGH ENOUGH TO INCLUDE THUNDERSTORM THREAT AT THIS TIME. MIXED LAYER
TEMPS STILL SUPPORT TEMPS IN THE 90S ACROSS MUCH OF THE
AREA...ALTHOUGH THERE DOES APPEAR TO BE SOME DISCREPANCIES FOR HOW
WARM THINGS WILL GET WITH SREF INDICATING A RANGE BETWEEN 97 AND
AROUND 88 FOR GLD. GIVEN OVERALL PATTERN AND POTENTIAL TO BE ON MUCH
DRIER SIDE OF THE DRYLINE THINK WARMER SOLUTIONS THE WAY TO AND MADE
ONLY MINOR CHANGES TO GOING FORECAST.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 230 AM MDT MON MAY 21 2012
TUESDAY NIGHT-WEDNESDAY NIGHT...DRY TUESDAY NIGHT WITH A CHANCE
FOR THUNDERSTORMS WEDNESDAY AFTERNOON ACROSS THE NORTHWEST PORTION
OF THE AREA WHERE BETTER MOISTURE AND JET DYNAMICS OCCUR. THIS
AREA OF FAVORABLE MOISTURE AND DYNAMICS REMAINS GENERALLY NORTH OF
INTERSTATE 70 WHERE HIGHEST POPS WILL REMAIN.
TOUGH CALL ON WEDNESDAYS HIGH TEMPERATURES. MODELS REMAIN
INCONSISTENT IN THE HANDLING OF THE COLD FRONT. DIDNT MAKE ANY
LARGE CHANGES FROM PREVIOUS FORECASTS AT THIS TIME AND WILL
CONTINUE TO ADVERTISE LOW 80S ACROSS THE NORTH...NEAR 90 ACROSS
THE SOUTH.
THURSDAY THROUGH SUNDAY...A NUMBER OF SHORTWAVE TROUGHS WILL
APPROACH AND MOVE OVER THE REGION AS A LONGWAVE TROUGH SLOWLY SHIFTS
EASTWARD OVER THE WESTERN CONUS. THE LONGWAVE TROUGH WILL DIG
SOUTHWARD FOR MUCH OF THE PERIOD BEFORE BEGINNING TO LIFT NORTHWARD
DURING THE DAYTIME ON SATURDAY. THE SHORTWAVE TROUGHS WILL BRING THE
POTENTIAL FOR SHOWERS AND THUNDERSTORMS TO THE AREA FOR MUCH OF THE
PERIOD.
FEEL INCREASINGLY CONFIDENT ABOUT PRECIP CHANCES ON THURSDAY MORNING
AS A COLD FRONT MOVES IN FROM THE NORTHWEST. GUIDANCE IS TRENDING
COOLER IN NORTHEASTERN COLORADO...WHICH MAKES SENSE GIVEN THE TIMING
OF THE FRONT...SO DECREASED MAX TEMPERATURES ON THURSDAY ALONG WITH
NEIGHBORING OFFICES. THE POTENTIAL FOR PRECIP ON FRIDAY NIGHT INTO
SATURDAY MORNING IS ALSO LOOKING BETTER AS A WARM FRONT LIFTS
NORTHWARD. CONDITIONS SHOULD BE WINDY ON SATURDAY AS A SURFACE LOW
DEEPENS OVER EASTERN COLORADO...BUT GUIDANCE NOW SHOWS HIGHER
RELATIVE HUMIDITIES COMPARED TO YESTERDAY...SO POTENTIAL FOR FIRE
WEATHER CONDITIONS LOOKS MORE LIKELY ON SUNDAY THAN SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1132 AM MDT MON MAY 21 2012
VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS AT BOTH LOCATIONS AS
DEVELOPING SFC TROUGH WILL KEEP WINDS OUT OF THE SOUTH IN THE 15
TO 20 KT RANGE THROUGH THE BULK OF THE PERIOD ALTHOUGH WINDS
SHOULD DIE DOWN A BIT IN THE OVERNIGHT HOURS. POTENTIAL FOR
ISOLATED THUNDERSTORMS BTWN 22 AND 2Z MAINLY AT GLD AS STORMS FORM
ALONG SFC TROUGH AND DRIFT EAST...BUT PROBABILITIES TOO LOW TO
INCLUDE IN TAFS ATTM.
&&
.FIRE WEATHER...
ISSUED AT 121 PM MDT MON MAY 21 2012
VERY WARM AND DRY WEATHER IS EXPECTED ACROSS MUCH OF THE AREA ON
TUESDAY...WITH AFTERNOON HUMIDITIES BELOW 15 PERCENT EXPECTED
ALONG AND EAST OF THE COLORADO AND KANSAS STATE LINE. WESTERLY
WINDS WILL GRADUALLY INCREASE IN THIS AREA TO AROUND 15 MPH IN THE
AFTERNOON. WITH RECENT RAINFALL AND WINDS NOT EXPECTED TO INCREASE
TO LATE IN THE AFTERNOON...OVERALL CONFIDENCE IN CRITICAL FIRE
WEATHER CONDITIONS IS TOO LOW TO WARRANT A WATCH OR WARNING AT
THIS POINT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...007/CJS
AVIATION...JRM
FIRE WEATHER...JRM
AREA FORECAST DISCUSSION
NWS GRAY ME
335 PM EDT MON MAY 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST TONIGHT AS LOW PRESSURE TRAVELS UP
THE EAST COAST. A COLD FRONT WILL APPROACH FROM THE WEST TOMORROW
TRIGGERING SHOWERS AND THUNDERSTORMS. THE REMAINDER OF THE WEEK WILL
BE WARM AND UNSETTLED WITH A CHANCE OF SHOWERS EACH DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL WEAKEN OVER THE AREA TONIGHT AS LOW PRESSURE
NEAR THE CAROLINA COAST MOVES NORTH. THE HIGH PRESSURE AS WELL AS
DIURNAL HEATING HAS BEEN ABLE TO SUPPRESS/SLOW DOWN THE STRATUS
DECK TO OUR SOUTH FOR THE MOST PART TODAY...BUT AS WE LOSE DAYTIME
HEATING THIS EVENING THE WARM FRONT WILL SURGE NORTHWARD. DRIZZLE
WILL START SOON AFTER ALONG THE COAST WITH TRUE RAIN MOVING IN
TONIGHT. THE HRRR IS HANDLING THIS SYSTEM BETTER THAN THE NAM
AND SO AM GOING CLOSER TO ITS SOLUTION IN THE FIRST FEW HOURS. AM
NOT EXPECTING MUCH QPF REALLY UNTIL AFTER MIDNIGHT IN NH AND
TOWARDS DAYBREAK IN MAINE. CLOUD COVER WILL KEEP OVERNIGHT LOWS IN
THE MID 50S MOST SPOTS.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
PW VALUES WILL BE AROUND +2 STANDARD DEVIATIONS ABOVE NORMAL
TOMORROW AS LOW PRESSURE PASSES BY TO OUR EAST DRAGGING TROPICAL
MOISTURE WITH IT. A COLD FRONT WILL APPROACH OUR NORTHERN BORDERS
LATE IN THE MORNING AND MOVE THROUGH NORTHERN NEW ENGLAND
THROUGHOUT THE DAY. THIS WILL HELP FOCUS THE MOISTURE AND WE
SHOULD SEE SOME HEAVY RAINFALL AT TIMES WITH URBAN FLOODING AT
TIMES. MODELS ARE DEPICTING MORE MUCAPE THAN SURFACE BASED CAPE
BUT STILL SHOULD HAVE A GOOD CHANCE AT CONVECTION. HIGH
TEMPERATURES WILL RANGE FROM THE LOWER TO MID 60S NORTH TO LOWER
70S SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A MILD AND AT TIMES UNSETTLED PATTERN THROUGH THIS PERIOD. UPPER
LEVEL RIDGE OVER THE REGION WITH A FEW DISTURBANCES MOVING
NORTHEAST IN THE FLOW. WITH INCREASE TEMPS AND MOISTURE THESE
DISTURBANCES SHOULD SET OFF A FEW SHOWERS. THE INCREASE IN TEMPS AND
MOISTURE SHOULD ALSO RESULT IN AREAS OF FOG AND DRIZZLE ESPECIALLY
ALONG COASTAL REGIONS AT NIGHT. LI`S AT OR SLIGHTLY BELOW ZERO WED
AFTERNOON. ISOLATED CONVECTION POSSIBLE. BEST CHANCE OF
THUNDERSTORMS APPEARS TO BE SATURDAY AHEAD OF A COLD FRONT THAT
CROSSES THE AREA.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
SHORT TERM...VFR CONDITIONS WILL DETERIORATE QUICKLY AFTER DARK AS
A WARM FRONT SURGES NORTH AND DRIZZLE...RAIN...AND FOG FOLLOW.
CEILINGS WILL DROP AS LOW AS LIFR. VISIBILITIES WILL BE WORSE
ALONG THE COAST THAN INLAND. IMPROVEMENT TO MVFR OR BETTER IS
LIKELY BY AFTERNOON TUESDAY.
LONG TERM...AREAS OF MVFR DURING THE DAY AND IFR NIGHT AS LOW
LEVEL MOISTURE INCREASES.
&&
.MARINE...
SHORT TERM...SEAS WILL APPROACH SMALL CRAFT CONDITIONS TOMORROW
NIGHT IN THE OUTER WATERS AS A COLD FRONT PUSHES OFFSHORE.
LONG TERM...WIND AND SEAS EXPECTED TO REMAIN BELOW SCA LEVELS.
&&
.FIRE WEATHER...
CLOUDS AND MOISTURE WILL INCREASE TONIGHT AS A WARM FRONT LIFTS
NORTH INTO THE AREA. SCATTERED SHOWERS AND HIGH RELATIVE HUMIDITIES
WILL LAST UNTIL WEDNESDAY. THERE WILL BE A CHANCE OF SHOWERS
WEDNESDAY THROUGH FRIDAY WITH A COLD FRONTAL PASSAGE AND MORE
SUBSTANTIAL RAINS SATURDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
HANES/LULOFS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1221 PM CDT MON MAY 21 2012
.AVIATION...18Z KGRI TAF. VFR CONDITIONS ARE EXPECTED THROUGHOUT
THE ENTIRE TAF PERIOD. THE MAIN CONCERN FOR THE PERIOD WILL FOCUS
ON INCREASED SOUTHERLY WINDS DURING THE MORNING AND AFTERNOON
HOURS TUESDAY. DEVELOPING LOW PRESSURE ALONG THE FRONT RANGE OF
THE ROCKIES MOUNTAINS WILL SLIDE EASTWARD OVERNIGHT TONIGHT. THIS
WILL HELP INCREASE THE PRESSURE GRADIENT ACROSS THE PLAINS.
COMBINED WITH BOUNDARY LAYER MIXING...SUSTAINED SOUTH WINDS NEAR
20 TO 25 KTS WILL BE POSSIBLE WITH GUSTS NEAR 30 KTS. OVERNIGHT
THIS EVENING...THE LOW LEVEL JET WILL ALSO KICK UP ACROSS THE
PLAINS. THIS MIGHT PROVIDE A WIND SHEAR THREAT DURING THE
OVERNIGHT HOURS. HOWEVER...AT THIS TIME DECIDED TO KEEP MENTION OF
LOW LEVEL WIND SHEAR OUT OF THE TAF...AS WINDS OVERNIGHT ARE
EXPECTED TO REMAIN AROUND 10 TO 15 KTS.
&&
.PREV DISCUSSION... /ISSUED 1034 AM CDT MON MAY 21 2012/
UPDATE...LIGHT SHOWERS HAVE BEGUN TO DISSIPATE ACROSS THE
FORECAST AREA.
PREV DISCUSSION... /ISSUED 447 AM CDT MON MAY 21 2012/
SHORT TERM...ALTHOUGH THE MAJORITY OF THE NEXT 72 HOURS SHOULD
REMAIN DRY...WILL HAVE TO DEAL WITH AT LEAST SOME SPRINKLES/BRIEF
SHOWERS THIS MORNING MAINLY IN THE NORTH...AND EVENTUALLY WHAT
SHOULD BE A MORE WIDESPREAD THUNDERSTORM RISK IN SOME AREAS
WEDNESDAY EVENING/NIGHT. ALSO OF CONCERN IS POSSIBLE
ADVISORY-LEVEL SOUTHERLY WIND ON TUESDAY.
08Z OBJECTIVE SURFACE ANALYSIS PLACES A BROAD 1025MB RIDGE AXIS
ACROSS EASTERN NEB...PROVIDING NEAR CALM TO VERY LIGHT
EAST/SOUTHEAST BREEZES TO THE CWA. ALTHOUGH MID LEVEL CLOUDS WILL
BE ON THE INCREASE THROUGH SUNRISE...MAINLY CLEAR SKIES THUS FAR
TONIGHT HAVE RESULTED IN AN EFFICIENT COOL DOWN INTO THE MID/UPPER
40S IN MOST AREAS. SPEAKING OF THOSE INCOMING MID CLOUDS AND
INCORPORATING RADAR TRENDS...SURE ENOUGH AND AS SUSPECTED HERE 24
HOURS AGO...A NARROW NORTH-SOUTH BAND OF MID-LEVEL THETA-E
ADVECTION EVIDENT AT 700MB HAS SPARKED AN AREA OF AT THE VERY
LEAST SCATTERED SPRINKLES/LIGHT SHOWERS AND EVEN A FEW WEAK
THUNDERSTORMS THAT HAVE SO FAR LARGELY STAYED JUST OUTSIDE THE CWA
ALONG AN AXIS FROM NEAR VALENTINE TO NORTH PLATTE. WATER VAPOR
IMAGERY CONFIRMS BROAD NORTHWEST FLOW ALOFT OVER THE CENTRAL
PLAINS...AS THE REGION LIES ALONG THE NORTHEAST PERIPHERY OF A
BUILDING MID/UPPER RIDGE AXIS EXTENDING ALL THE WAY BACK TO THE
PACIFIC NORTHWEST...WHERE THE NEXT LARGER SCALE SHORTWAVE/UPPER
JET STREAK OF INTEREST IS ARRIVING ON THE SCENE.
THE IMMEDIATE ISSUE THROUGH AT LEAST THE NEXT 4-6 HOURS IS THE
EVOLUTION OF DEVELOPING SHOWER ACTIVITY THIS MORNING. THIS NARROW
CORRIDOR OF HIGH BASED CONVECTION IS CLASSICALLY LOCATED ALONG THE
LEADING EDGE OF 700MB THETA-E ADVECTION...AND IMMEDIATELY EAST OF
THE CORE OF THE 850MB LOW LEVEL JET CURRENTLY CENTERED FROM FAR
WESTERN KS INTO WESTERN NEB. AS USUAL...DETERMINISTIC MODELS SUCH
AS NAM/GFS/ECMWF ARE STRUGGLING TO FULLY CAPTURE THIS ACTIVITY IN
THEIR QPF FIELDS...WHILE HIGHER RESOLUTION SHORT TERM MODELS SUCH
AS THE HRRR AND 0Z 4KM WRF-NMM ARE PROVING BETTER. OBJECTIVE RUC
ANALYSIS AND 06Z NAM CONFIRM THAT ELEVATED MUCAPE VALUES MAINLY IN
THE 800-650MB LAYER ARE ONLY RUNNING A MEAGER 100 J/KG OR SO.
FOLLOWING THE 06Z NAM...THIS BAND OF MID LEVEL THETA-E ADVECTION
SHOULD CONTINUE TO STEADILY TRACK EAST MAINLY ACROSS THE NORTHERN
1/2 OF NEB THROUGH THE MORNING HOURS...AT LEAST PUTTING PARTS OF
THE NORTHERN CWA IN LINE FOR NUISANCE AND UNFORTUNATELY PREVIOUSLY
UN-ADVERTISED PRECIPITATION. HAVE DEBATED BETWEEN GOING WITH A
MEASURABLE POP/SHOWER AND MAYBE EVEN AN ISOLATED THUNDERSTORM
MENTION...BUT AT LEAST TO START OUT WITH THIS MORNING WILL
TRY...REPEAT TRY...TO GET AWAY WITH ONLY SCATTERED SPRINKLE
MENTION ALONG AND NORTH OF I-80 WITH EXPECTATION THAT MEASURABLE
PRECIP SHOULD NOT BE OVERLY WIDESPREAD. STAY TUNED FOR POSSIBLE
UPDATES HOWEVER AS RADAR TRENDS EVOLVE. OBVIOUSLY EVEN IF ANY
ROGUE LIGHTNING STRIKES TO MANAGE TO SNEAK IN...WOULD NOT
ANTICIPATE ANYTHING CLOSE TO BEING SEVERE...WITH EVEN SMALL HAIL
HARD TO COME BY. WITH EXPECTATION OF THIS BEING A MORNING-ONLY
ISSUE...HAVE NO PRECIP MENTION WITHIN THE CWA BEYOND 17Z...AS THE
AFTERNOON HOURS WILL FEATURE THE PRIMARY LOWER LEVEL INSTABILITY
AXIS SETTING UP WEST OF THE CWA ALONG AN AXIS FROM FAR WESTERN KS
NORTHWARD INTO WESTERN NEB. MEANWHILE...SOUTH/SOUTHEAST WIND WILL
BE ON THE INCREASE AS THE DAY WEARS ON...AS THE SURFACE RIDGE AXIS
DEPARTS EAST INTO IA/MO. AS A RESULT...THE AFTERNOON HOURS WILL
FEATURE SUSTAINED SPEEDS RANGING FROM NEAR 15 MPH IN FAR EASTERN
COUNTIES...TO 20-25 MPH IN SOME WESTERN AREAS ALONG WITH GUSTS TO
AROUND 30 MPH. TEMP WISE TODAY...CHANGED HIGHS LITTLE FROM
PREVIOUS FORECAST...AND FOLLOWED 0Z NAM RAW TEMPS QUITE CLOSELY.
ALTHOUGH PASSING MID LEVEL CLOUDS THIS MORNING COULD PUT A
TEMPORARY DELAY ON THE DIURNAL CLIMB...HAVE AIMED MOST OF THE CWA
INTO THE 77-81 RANGE FOR EVENTUAL HIGHS.
THIS EVENING/TONIGHT...ANY STORMS THAT MANAGE TO FORM OUT IN
WESTERN NEB LATE THIS AFTERNOON WITHIN THE INSTABILITY AXIS SHOULD
STEADILY FADE AWAY LONG BEFORE MAKING IT INTO THE CWA. THAT BEING
SAID...HAVE OPTED TO DISREGARD THE 00Z GFS SOLUTION WHICH BREAKS
OUT WIDESPREAD QPF TONIGHT MAINLY IN SOUTHWEST/CENTRAL KS...BUT
ALSO BRUSHING UP INTO THE KS ZONES OF OUR CWA. WITH THE NAM/ECMWF
AND 4KM WRF-NMM ESSENTIALLY SHOWING NOTHING OF THIS NATURE...IT
JUST SEEMS TOO MUCH AN OUTLIER AND HAVE KEPT THE ENTIRE CWA
PRECIP-FREE TONIGHT. ALOFT...THE HEART OF THE MID/UPPER RIDGE AXIS
WILL SET UP OVER THE CENTRAL PLAINS TONIGHT...AS THE UPSTREAM
TROUGH/JET STREAK START CROSSING THE NORTHERN ROCKIES. AT THE
SURFACE...STEADY SOUTHERLY BREEZES SHOULD HELP HOLD TEMPS UP ABOUT
10 DEGREES WARMER THAN THOSE THIS MORNING...AND HAVE MOST OF THE
CWA IN THE 55-58 RANGE FOR LOWS...WHICH IS VERY SLIGHTLY WARMER
THAN PREVIOUS FORECAST.
TUESDAY IS STILL SHAPING UP TO BE THE WARMEST DAY OF THE
WEEK...WITH PLENTY OF SOUTHERLY WIND TO GO WITH IT. STARTING WITH
STORM CHANCES...HAVE KEPT IT STORM FREE THROUGH THE DAY...AS EVEN
THOUGH DEWPOINTS WILL BE IN THE INCREASE INTO THE 50S IN MOST
AREAS WITH A CORRESPONDING INCREASE IN LOW LEVEL INSTABILITY...MID
LEVEL TEMPS WILL ALSO BE ON THE INCREASE...WITH NAM SOUNDINGS
CONFIRMING A DECENT CAPPING INVERSION. BY LATE AFTERNOON...THE
NAM/GFS/ECMWF ARE IN GENERAL AGREEMENT SETTING UP A 990-994MB LOW
IN FAR WESTERN NEBRASKA...WITH PRESSURE FALLS DURING THE DAY
SETTING UP QUITE A HEALTHY EAST-WEST SURFACE PRESSURE GRADIENT
DURING THE DAY. THIS GRADIENT...IN TANDEM WITH SHOULD BE PLENTY OF
SUN AND MIXING TO AT LEAST THE 800MB LEVEL SHOULD HELP CRANK UP
THE SOUTHERLY WIND. TAKING A CONSENSUS OF 00Z MET/MAV GUIDANCE FOR
SPEEDS...HAVE MOST OF THE CWA CURRENTLY TOPPING OUT IN THE 25-30
MPH RANGE FOR SUSTAINED SPEEDS...WHICH IF IT WERE TO HOLD WOULD
GENERALLY FALL JUST SHORT OF WIND ADVISORY CRITERIA.
HOWEVER...COULD EASILY FORESEE AT LEAST WESTERN PORTIONS OF THE
CWA ENDING UP WITH HIGHER SPEEDS OVER 30 MPH...AND ALTHOUGH WILL
FOREGO ANY HEADLINE ISSUANCE STILL BEING 3 PERIODS OUT...WILL
CONTINUE TO HIGHLIGHT AT LEAST NEAR-ADVISORY SPEEDS IN THE HWO.
CERTAINLY GUSTS TO AROUND 40 MPH SHOULD BE COMMON NO MATTER WHAT
DURING THE AFTERNOON. TEMP-WISE...AGAIN LEANED HEAVILY ON RAW 0Z
NAM NUMBERS...WHICH RESULTED IN LITTLE CHANGE FROM PREVIOUS ACROSS
EASTERN ZONES...BUT ACTUALLY A SLIGHT LOWERING IN WESTERN AREAS.
THIS RESULTS IN MOST AREAS TOPPING OUT BETWEEN 87-90...WHICH IS
STILL AT LEAST A FEW DEGREES ABOVE MET GUIDANCE. IF SURFACE
DEWPOINTS MANAGE TO MIX DOWN FURTHER THAN CURRENTLY THOUGHT...THEN
COULD EASILY SEE PARTS OF THE SOUTHWEST CWA TRY TO MAKE A RUN AT
MID 90S BUT WILL KEEP IT BELOW THIS FOR NOW.
TUESDAY NIGHT...KEPT IT STORM FREE DESPITE THE LEADING EDGE
FORCING FROM THE INCOMING SHORTWAVE/JET STREAK STARTING TO IMPINGE
ON WESTERN PORTIONS OF THE REGION. ALTHOUGH THE LOW LEVEL JET WILL
REALLY RAMP UP OVER THE CWA DURING THE NIGHT...SPEED CONVERGENCE
IS NOT REALLY PRESENT AND MORE IMPORTANTLY...VERY WARM MID LEVEL
TEMPS AS EVIDENCED BY 700MB TEMPS CLIMBING INTO AT LEAST THE
12-14C RANGE SHOULD PROVIDE A VERY STOUT CAP EVEN TO ELEVATED
PARCELS. EVEN WITH THE APPROACH OF A SURFACE-850MB COLD FRONT
AFTER MIDNIGHT ACROSS WESTERN NEB...JUST NOT SEEING THIS CAP
BREAKING WITH LARGE SCALE FORCING STILL LIMITED. TEMP
WISE...SHOULD BE A SEASONABLY MILD NIGHT AND LEFT LOWS PRETTY MUCH
ALONE IN THE LOW-MID 60S.
WEDNESDAY DAYTIME...OPTED TO STAY CONSISTENT WITH PREVIOUS
FORECAST AND LEAVE OUT STORM MENTION...BUT WILL SAY THAT WOULD NOT
BE SURPRISED IF AT LEAST A SLIGHT POP COULD BE ADDED AT SOME
POINT. THE MAIN THING HOLDING BACK A LEGITIMATE DAYTIME STORM THREAT
IS CONTINUED STRONG CAPPING...WITH THE LATEST 06Z NAM FINALLY
FALLING IN LINE WITH THE GFS/ECWMF SOLUTIONS IN KEEPING FAIRLY
TOASTY 700MB TEMPS IN PLACE THROUGH THE DAY...DESPITE THE INVASION
OF A SURFACE COLD FRONT INTO NORTHWEST PARTS OF THE CWA. EVEN THE
LATEST RUN OF THE SREF THUNDER PROBABILITIES HAS BACKED OFF A BIT
ON THE FAIRLY SLIM RISK OF PRE-00Z CONVECTIVE INITIATION. ASSUMING
THAT IT REMAINS STORM-FREE...THE MAIN ISSUE FOR WEDNESDAY IS A
TRICKY HIGH TEMP FORECAST...AS ALTHOUGH THE SOUTHEAST 1/2 OR SO OF
THE CWA SHOULD REMAIN FIRMLY IN THE WARM SECTOR...NORTHWEST ZONES
COULD SEE AT LEAST WEAK COLD AIR ADVECTION/NORTHEAST WIND. OPTED
TO WARM UP MOST AREAS 2-3 DEGREES FROM PREVIOUS FORECAST SIDING
WITH SLOWER INVASION OF COOLER AIR...NOW ADVERTISING A RANGE FROM
NEAR 80 FAR NORTHWEST TO LOW 90S SOUTHEAST.
WEDNESDAY NIGHT...THIS IS CLEARLY THE MOST FAVORED PERIOD FOR
POTENTIALLY...REPEATING POTENTIALLY WIDESPREAD THUNDERSTORM
ACTIVITY...AS MID LEVEL TEMPS SHOULD BE ABLE TO COOL ENOUGH AT
LEAST IN NORTHWEST ZONES TO ALLOW INITIATION. ON THE LARGER
SCALE...LEGITIMATE FORCING FINALLY ARRIVES IN THE FORM OF AN OPEN
MID LEVEL SHORTWAVE AND THE EXIT REGION OF A 300MB JET STREAK
APPROACHING FROM THE CENTRAL ROCKIES. THAT BEING SAID...LATEST
MODEL CONSENSUS IS TO REALLY LIMIT STORM DEVELOPMENT ACROSS
SOUTHEAST ZONES...WHILE MAINLY TARGETING NORTHWEST ZONES WITH
CONVECTION...AND LEAVING CENTRAL PLACES INCLUDING THE TRI CITIES A
BIT IN LIMBO. FOR NOW...OPTED TO KEEP POPS SIMILAR TO PREVIOUS
FORECAST...RANGING FROM LIKELY 60S IN THE NORTHWEST TO NO STORM
MENTION FAR SOUTHEAST...AND A GRADUAL GRADIENT OF SLIGHT CHANCE TO
CHANCE POPS IN BETWEEN. THE POTENTIAL IS CERTAINLY THERE FOR
A WIDESPREAD FLARE UP OF STORMS...AS THE NAM ADVERTISES
CONSIDERABLE CONVERGENCE ACROSS A SHARP 850MB FRONT...WITH A LOW
LEVEL JET POTENTIALLY IN EXCESS OF 60KT BLASTING INTO THIS
BOUNDARY. WITH ELEVATED INSTABILITY POTENTIALLY INTO THE 1000-2000
J/KG RANGE IN THE EVENING...ALONG WITH DEEP LAYER SHEAR ON THE
ORDER OF 50-70KT...A ROUND OF SEVERE STORMS WITH HAIL/WIND IS VERY
POSSIBLE...AGAIN MAINLY FAVORING THE LESS-CAPPED NORTHWEST ZONES.
CERTAINLY PLENTY OF DETAILS TO IRON OUT OVER THE NEXT FEW DAYS
THOUGH.
LONG TERM...STARTING 12Z THURSDAY. GUIDANCE CONTINUES TO SUGGEST MID
AND UPPER LEVEL JET ENERGY WILL PERSIST OVER THE CENTRAL PLAINS
THROUGH MUCH OF THE LONG TERM FORECAST PERIOD. AT THE SURFACE A
RIDGE HIGH PRESSURE IS EXPECTED TO DOMINATE THE LOW LEVELS
THURSDAY THROUGH MUCH OF FRIDAY...WITH LOW LEVEL RETURN FLOW
MATERIALIZING ACROSS THE AREA LATE FRIDAY ONWARD.
THE OPERATIONAL GFS AND EC BOTH ADVERTISE MID LEVEL PERTURBATIONS
WILL PUSH OVER THE AREA DURING THE DAY THURSDAY...WITH PERHAPS
ENOUGH OMEGA AND MOISTURE FOR PRECIPITATION PRODUCTION ACROSS
NORTHERN PORTIONS OF THE CWA. THE RIGHT-REAR QUADRANT OF A ~70KT MID
LEVEL JET STREAK IS THEN EXPECTED TO PROMOTE ENOUGH OF A DIRECT
THERMAL CIRCULATION FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE
CWA THURSDAY NIGHT INTO FRIDAY MORNING. AN OVERALL LACK IN KINEMATIC
FORCING IS THEN EXPECTED TO BRING DRY CONDITIONS TO THE AREA DURING
THE DAY FRIDAY...WITH THE EMERGENCE OF A ~40KT LOW LEVEL JET
BRINGING ANOTHER POSSIBILITY OF PRECIPITATION TO THE AREA FRIDAY
NIGHT INTO SATURDAY MORNING. ONE MORE ROUND OF NOCTURNAL
PRECIPITATION THEN APPEARS POSSIBLE SATURDAY NIGHT INTO SUNDAY
MORNING AS A STRONGER LOW LEVEL JET INFILTRATES THE AREA.
LOW LEVEL MOISTURE REMAINS LESS THAN IMPRESSIVE THROUGH FRIDAY AS
SURFACE RIDGING REMAINS ENTRENCHED ACROSS THE AREA AND AS A
RESULT...INSTABILITY SUFFERS GREATLY. CONTEMPLATED TAKEN THUNDER OUT
OF THE FORECAST ALTOGETHER THURSDAY AND THURSDAY NIGHT BUT WITH THE
OPERATIONAL GFS AND EC BOTH SUGGESTING MAYBE AROUND 100J/KG DEEP
LAYER MUCAPE VALUES...WENT AHEAD WITH ISOLATED THUNDER MENTION FOR
THAT TIME BEING. LOW LEVEL MOISTURE FLUX INTO THE AREA VIA LOW LEVEL
RETURN FLOW SHOULD ALLOW FOR INCREASING INSTABILITY VALUES HEADING
INTO THE WEEKEND...WITH 1000-2000J/KG DEEP LAYER MUCAPE VALUES BEING
ADVERTISED BY THE OPERATIONAL GFS AND EC.
NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES ARE STILL EXPECTED
THURSDAY AS SURFACE RIDGING REMAINS OVER THE AREA. LOW LEVEL RETURN
FLOW WILL THEN PROMOTE A WARMING TREND...WITH TEMPERATURES CLIMBING
TO LEVELS WELL ABOVE-NORMAL FOR THIS TIME OF YEAR ACROSS OUR SOUTH
ON FRIDAY...AND ACROSS THE ENTIRE CWA SATURDAY ONWARD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
343 PM EDT MON MAY 21 2012
.SYNOPSIS...
TROPICAL STORM ALBERTO WILL LINGER OFF THE CAROLINA COAST TONIGHT
BEFORE BEGINNING TO PULL AWAY TO THE NORTHEAST ON TUESDAY. AN UPPER
LEVEL LOW PRESSURE AND ASSOCIATED A COLD FRONT WILL MOVE THROUGH
THE REGION ON TUESDAY. THE LOW PRESSURE WILL STEADILY LIFT NORTHEAST
THROUGH MID WEEK...REPLACED BY BUILDING HIGH PRESSURE AND
UNSEASONABLY WARM TEMPERATURES LATE THIS WEEK THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
AT 130 PM...VISIBLE SATELLITE PICS SHOW SOME ENHANCED CUMULUS OVER
THE MOUNTAINS AND RADAR SHOWS THAT SOME WIDELY SCATTERED SHOWERS
HAVE DEVELOPED. EXPECT COVERAGE TO INCREASE TO SOLID SCATTERED
COVERAGE BY MID AFTERNOON OVER THE MOUNTAINS. MESOSCALE MODELS LIKE
THE HRRR STILL SUGGEST THAT SOME SCATTERED
SHOWERS/THUNDERSTORMS WILL MOVE OUT INTO THE FOOTHILLS/PIEDMONT BY
LATE AFTERNOON PROBABLY ALONG OUTFLOW BOUNDARIES. AT THE SAME
TIME...A WEAK FRONT ALSO LOOKS LIKE IT WILL MOVE INTO THE
MOUNTAINS BY LATE AFTENROON AND PERHAPS MERGE WITH THE OUTFLOW
BOUDARIES SO THAT IT MOVES OUT INTO THE PIEDMONT DURING THE
EVENING HOURS. HOWEVER...SURFACE CONVERGENCE WILL BE QUITE LIMITED
SO EXPECT THAT CONVECTION WILL WANE WITH COOLING. CURRENT POP
FIELD HANDLES THIS WELL.
FOR THE OVERNIGHT...AN UPPER TROUGH WILL SLOWLY APPROACH FROM THE
WEST BY LATE TONIGHT. FALLING HEIGHTS AND WEAK UPSLOPE SHOULD
TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS
LATE TONIGHT. USED A MOS BLEND FOR TEMPS.
ON TUE...THE UPPER TROUGH IS FORECAST TO ONLY MOVE MARGINALLY
EASTWARD WITH ITS AXIS PERHAPS REACHING THE MOUNTAINS LATE IN THE
DAY. WEAK UPPER DIFFLUENCE AND THE STALLED SURFACE BOUNDARY SHOULD
BE ENOUGH TO TRIGGER SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS TUE AFTERNOON. A GUIDANCE BLEND PUTS TEMPS NEAR
AVERAGE.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM MONDAY...MODELS ARE IN FAIR AGREEMENT SLOWING DOWN THE
PROGRESSION OF THE UPPER TROF/LOW CENTER MOVG NE TUE NIGHT-WED BUT
THE WEAK SFC FRONT SHOULD STILL MOVE SLOWLY E OF THE AREA BEFORE
WASHING OUT DURING THE DAY WED. RETURNING LOW LVL S FLOW WILL BRING
MOISTURE OVER THE REGION AND KEEP A CHC OF SCT SHWRS/TSTMS WED
AFTN-EVE...ESP OVER THE MTNS IN AREAS OF BEST UPSLOPE. THE UPPER LOW
MEANDERS OVER THE SE US WED NIGHT-THU WITH A SERIES OF WEAK UPPER
DISTURBANCES ROTATING AROUND IT AND OVER THE AREA...WHILE ENOUGH LOW
LVL MOISTURE REMAINS OVER THE CWA FOR A CONTINUING CHC OF SHWRS AND
TSTMS THU...ESP OVER THE MTNS WITH AFTN HEATING. LOOK FOR TEMPS NEAR
TO SLIGHTLY ABOVE AVG THRU THE PD.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM MONDAY...THE LATEST MODELS ARE IN GOOD AGREEMENT WITH
THE STRONG UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDING OVER THE
EASTERN CONUS AND REMAIN PREDOMINANT LATE THURSDAY INTO SATURDAY.
EXPECT UNSEASONABLY WARM TEMPERATURES AND MOSTLY DRY CONDITIONS
ACROSS MUCH OF PIEDMONT/VALLEYS DURING THE PERIOD. HOWEVER...A
COMBINATION OF UPSLOPE FLOW(SE TO E) AND DIURNAL INSTABILITY MAY
SUPPORT THE DEVELOPMENT OF AFTERNOON ISOLATED/SCATTERED
THUNDERSTORMS ALONG THE BLUE RIDGE MOUNTAINS EACH DAY. SO HAVE KEPT
SLIGHT CHANCE POPS THERE WITH DRY ELSEWHERE. DAYTIME HIGHS OVER THE
PIEDMONT WILL BE IN THE UPPER 80S THU/FRI AND WARMING INTO THE LOW
90S SATURDAY.
SUNDAY AND MONDAY...CONFIDENCE IS LOW AS THE MODELS SHOW DIFFERENT
SOLUTIONS. THE CANADIAN MODEL SHOWS A CUT OFF LOW FORMING OFF THE
NORTH CAROLINA COAST BY EARLY SUNDAY AND LINGERS INTO MONDAY WHILE
THE GFS AND THE ECMWF SUGGEST A TROPICAL WAVE OVER THE ATLANTIC
OCEAN MOVING WEST INTO THE GA/SC COAST BY SUNDAY. DUE TO THE
TROPICAL MOISTURE INFLUX FROM THE SE AND DIURNAL INSTABILITY...WILL
CARRY SLIGHT CHANCE POPS ACROSS MUCH OF OUR CWA. DAYTIME HIGHS WILL
REMAIN 5-10 DEGREES ABOVE NORMALS SUN/MON.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AT KCLT...MAIN QUESTION FPR THE NEAR TERM IS WHETHER ANY CONVECTION
WILL AFFECT THE AIRFIELD LATE THIS AFTERNOON INTO EARLY EVENING. THE
HRRR SUGGESTS THAT THERE WILL BE SCATTERED CONVECTION IN THE
VICINITY OF THE AIRFIELD CIRCA 00Z. FOR NOW WILL JUST HAVE A VCSH
FROM 00Z-02Z. FOR THE OVERNIGHT JUST A MID LEVEL CEILING IS EXPECTED
WITH PERHAPS SOME LIGHT FOG AROUND DAYBREAK RESTRICTING THE VSBY TO
AROUND 5SM. LOOKS LIKE TUE`S CONVECTION SHOULD HOLD OFF UNTIL AFTER
THE END OF THIS TAF PERIOD.
ELSEWHERE...SCT TO NUMEROUS SHOWERS/THUNDERSTORMS ARE FORECAST TO
DEVELOP OVER THE MOUNTAINS BY 20Z. WILL CARRY A TEMPO AT KAVL FOR
THUNDER AND MVFR RESTRICTIONS FROM 20-22Z. MESOSCALE MODELS SUGGEST
THAT CONVECTION WILL MOVE INTO THE FOOTHILLS/PIEDMONT LATE THIS
AFTERNOON AND EVENING. HENCE...WUILL CARRY A VCTS AT KHKY AND KGSP.
THE PREPONDERANCE OF GUIDANCE IS FORCASTING AT LEAST MVFR VSBY
RESTRICTIONS IN FOG AROUND DAYBREAK TUE...WITH IFR POSSIBLE AT KAVL.
CONVECTION WILL GET AN EARLY START ON TUE WITH A CHANCE OF THUNDER
AT KAVL BY 18Z.
OUTLOOK...SHOWER AND TSTM CHANCES WILL DIMINSH DIURNALLY TUE NIGHT
BUT RE-DEVELOP AGAIN WED AFTERNOON MOST AREAS. DIURNAL THUNDERSTORMS
TOWARD THE END OF THE WEEK WILL BE MORE LIKELY CONFINED TO THE
MOUNTAINS AND FOOTHILLS. EARLY MORNING RESTRICTIONS DUE TO FOG ARE A
GOOD BET MAINLY IN THE MOUNTAIN VALLEYS EACH MORNING.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...LG
SHORT TERM...RB
LONG TERM...JOH
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
239 PM EDT MON MAY 21 2012
.SYNOPSIS...
TROPICAL STORM ALBERTO WILL LINGER OFF THE CAROLINA COAST TONIGHT
BEFORE BEGINNING TO PULL AWAY TO THE NORTHEAST ON TUESDAY. AN UPPER
LEVEL LOW PRESSURE AND ASSOCIATED A COLD FRONT WILL MOVE THROUGH
THE REGION ON TUESDAY. THE LOW PRESSURE WILL STEADILY LIFT NORTHEAST
THROUGH MID WEEK...REPLACED BY BUILDING HIGH PRESSURE AND
UNSEASONABLY WARM TEMPERATURES LATE THIS WEEK THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
AT 130 PM...VISIBLE SATELLITE PICS SHOW SOME ENHANCED CUMULUS OVER
THE MOUNTAINS AND RADAR SHOWS THAT SOME WIDELY SCATTERED SHOWERS
HAVE DEVELOPED. EXPECT COVERAGE TO INCREASE TO SOLID SCATTERED
COVERAGE BY MID AFTERNOON OVER THE MOUNTAINS. MESOSCALE MODELS LIKE
THE HRRR STILL SUGGEST THAT SOME SCATTERED
SHOWERS/THUNDERSTORMS WILL MOVE OUT INTO THE FOOTHILLS/PIEDMONT BY
LATE AFTERNOON PROBABLY ALONG OUTFLOW BOUNDARIES. AT THE SAME
TIME...A WEAK FRONT ALSO LOOKS LIKE IT WILL MOVE INTO THE
MOUNTAINS BY LATE AFTENROON AND PERHAPS MERGE WITH THE OUTFLOW
BOUDARIES SO THAT IT MOVES OUT INTO THE PIEDMONT DURING THE
EVENING HOURS. HOWEVER...SURFACE CONVERGENCE WILL BE QUITE LIMITED
SO EXPECT THAT CONVECTION WILL WANE WITH COOLING. CURRENT POP
FIELD HANDLES THIS WELL.
FOR THE OVERNIGHT...AN UPPER TROUGH WILL SLOWLY APPROACH FROM THE
WEST BY LATE TONIGHT. FALLING HEIGHTS AND WEAK UPSLOPE SHOULD
TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS
LATE TONIGHT. USED A MOS BLEND FOR TEMPS.
ON TUE...THE UPPER TROUGH IS FORECAST TO ONLY MOVE MARGINALLY
EASTWARD WITH ITS AXIS PERHAPS REACHING THE MOUNTAINS LATE IN THE
DAY. WEAK UPPER DIFFLUENCE AND THE STALLED SURFACE BOUNDARY SHOULD
BE ENOUGH TO TRIGGER SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS TUE AFTERNOON. A GUIDANCE BLEND PUTS TEMPS NEAR
AVERAGE.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM MONDAY...MODELS ARE IN FAIR AGREEMENT SLOWING DOWN THE
PROGRESSION OF THE UPPER TROF/LOW CENTER MOVG NE TUE NIGHT-WED BUT
THE WEAK SFC FRONT SHOULD STILL MOVE SLOWLY E OF THE AREA BEFORE
WASHING OUT DURING THE DAY WED. RETURNING LOW LVL S FLOW WILL BRING
MOISTURE OVER THE REGION AND KEEP A CHC OF SCT SHWRS/TSTMS WED
AFTN-EVE...ESP OVER THE MTNS IN AREAS OF BEST UPSLOPE. THE UPPER LOW
MEANDERS OVER THE SE US WED NIGHT-THU WITH A SERIES OF WEAK UPPER
DISTURBANCES ROTATING AROUND IT AND OVER THE AREA...WHILE ENOUGH LOW
LVL MOISTURE REMAINS OVER THE CWA FOR A CONTINUING CHC OF SHWRS AND
TSTMS THU...ESP OVER THE MTNS WITH AFTN HEATING. LOOK FOR TEMPS NEAR
TO SLIGHTLY ABOVE AVG THRU THE PD.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 200 PM MONDAY...THE LATEST MODELS ARE IN GOOD AGREEMENT WITH
THE STRONG UPPER LEVEL RIDGE OF HIGH PRESSURE BUILDING OVER THE
EASTERN CONUS AND REMAIN PREDOMINANT LATE THURSDAY INTO SATURDAY.
EXPECT UNSEASONABLY WARM TEMPERATURES AND MOSTLY DRY CONDITIONS
ACROSS MUCH OF PIEDMONT/VALLEYS DURING THE PERIOD. HOWEVER...A
COMBINATION OF UPSLOPE FLOW(SE TO E) AND DIURNAL INSTABILITY MAY
SUPPORT THE DEVELOPMENT OF AFTERNOON ISOLATED/SCATTERED
THUNDERSTORMS ALONG THE BLUE RIDGE MOUNTAINS EACH DAY. SO HAVE KEPT
SLIGHT CHANCE POPS THERE WITH DRY ELSEWHERE. DAYTIME HIGHS OVER THE
PIEDMONT WILL BE IN THE UPPER 80S THU/FRI AND WARMING INTO THE LOW
90S SATURDAY.
SUNDAY AND MONDAY...CONFIDENCE IS LOW AS THE MODELS SHOW DIFFERENT
SOLUTIONS. THE CANADIAN MODEL SHOWS A CUT OFF LOW FORMING OFF THE
NORTH CAROLINA COAST BY EARLY SUNDAY AND LINGERS INTO MONDAY WHILE
THE GFS AND THE ECMWF SUGGEST A TROPICAL WAVE OVER THE ATLANTIC
OCEAN MOVING WEST INTO THE GA/SC COAST BY SUNDAY. WITH THAT
SAID...HAVE KEPT SLIGHT CHANCE POPS OVER MUCH OF OUR CWA DURING THE
PERIOD.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AT KCLT...MAIN QUESTION FPR THE NEAR TERM IS WHETHER ANY CONVECTION
WILL AFFECT THE AIRFIELD LATE THIS AFTERNOON INTO EARLY EVENING. THE
HRRR SUGGESTS THAT THERE WILL BE SCATTERED CONVECTION IN THE
VICINITY OF THE AIRFIELD CIRCA 00Z. FOR NOW WILL JUST HAVE A VCSH
FROM 00Z-02Z. FOR THE OVERNIGHT JUST A MID LEVEL CEILING IS EXPECTED
WITH PERHAPS SOME LIGHT FOG AROUND DAYBREAK RESTRICTING THE VSBY TO
AROUND 5SM. LOOKS LIKE TUE`S CONVECTION SHOULD HOLD OFF UNTIL AFTER
THE END OF THIS TAF PERIOD.
ELSEWHERE...SCT TO NUMEROUS SHOWERS/THUNDERSTORMS ARE FORECAST TO
DEVELOP OVER THE MOUNTAINS BY 20Z. WILL CARRY A TEMPO AT KAVL FOR
THUNDER AND MVFR RESTRICTIONS FROM 20-22Z. MESOSCALE MODELS SUGGEST
THAT CONVECTION WILL MOVE INTO THE FOOTHILLS/PIEDMONT LATE THIS
AFTERNOON AND EVENING. HENCE...WUILL CARRY A VCTS AT KHKY AND KGSP.
THE PREPONDERANCE OF GUIDANCE IS FORCASTING AT LEAST MVFR VSBY
RESTRICTIONS IN FOG AROUND DAYBREAK TUE...WITH IFR POSSIBLE AT KAVL.
CONVECTION WILL GET AN EARLY START ON TUE WITH A CHANCE OF THUNDER
AT KAVL BY 18Z.
OUTLOOK...SHOWER AND TSTM CHANCES WILL DIMINSH DIURNALLY TUE NIGHT
BUT RE-DEVELOP AGAIN WED AFTERNOON MOST AREAS. DIURNAL THUNDERSTORMS
TOWARD THE END OF THE WEEK WILL BE MORE LIKELY CONFINED TO THE
MOUNTAINS AND FOOTHILLS. EARLY MORNING RESTRICTIONS DUE TO FOG ARE A
GOOD BET MAINLY IN THE MOUNTAIN VALLEYS EACH MORNING.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...LG
SHORT TERM...RB
LONG TERM...JOH
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
146 PM EDT MON MAY 21 2012
.SYNOPSIS...
TROPICAL STORM ALBERTO WILL LINGER OFF THE CAROLINA COAST TONIGHT
BEFORE BEGINNING TO PULL AWAY TO THE NORTHEAST ON TUESDAY. AN UPPER
LEVEL LOW PRESSURE AND ASSOCIATED A COLD FRONT WILL MOVE THROUGH
THE REGION ON TUESDAY. THE LOW PRESSURE WILL STEADILY LIFT NORTHEAST
THROUGH MID WEEK...REPLACED BY BUILDING HIGH PRESSURE AND
UNSEASONABLY WARM TEMPERATURES LATE THIS WEEK THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
AT 130 PM...VISIBLE SATELLITE PICS SHOW SOME ENHANCED CUMULUS OVER
THE MOUNTAINS AND RADAR SHOWS THAT SOME WIDELY SCATTERED SHOWERS
HAVE DEVELOPED. EXPECT COVERAGE TO INCREASE TO SOLID SCATTERED
COVERAGE BY MID AFTERNOON OVER THE MOUNTAINS. MESOSCALE MODELS
LIKE THE HRRR STILL SUGGEST THAT SOME SCATTERED
SHOWERS/THUNDERSTORMS WILL MOVE OUT INTO THE FOOTHILLS/PIEDMONT BY
LATE AFTERNOON PROBABLY ALONG OUTFLOW BOUNDARIES. AT THE SAME
TIME...A WEAK FRONT ALSO LOOKS LIKE IT WILL MOVE INTO THE
MOUNTAINS BY LATE AFTENROON AND PERHAPS MERGE WITH THE OUTFLOW
BOUDARIES SO THAT IT MOVES OUT INTO THE PIEDMONT DURING THE
EVENING HOURS. HOWEVER...SURFACE CONVERGENCE WILL BE QUITE LIMITED
SO EXPECT THAT CONVECTION WILL WANE WITH COOLING. CURRENT POP
FIELD HANDLES THIS WELL.
FOR THE OVERNIGHT...AN UPPER TROUGH WILL SLOWLY APPROACH FROM THE
WEST BY LATE TONIGHT. FALLING HEIGHTS AND WEAK UPSLOPE SHOULD
TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS
LATE TONIGHT. USED A MOS BLEND FOR TEMPS.
ON TUE...THE UPPER TROUGH IS FORECAST TO ONLY MOVE MARGINALLY
EASTWARD WITH ITS AXIS PERHAPS REACHING THE MOUNTAINS LATE IN THE
DAY. WEAK UPPER DIFFLUENCE AND THE STALLED SURFACE BOUNDARY SHOULD
BE ENOUGH TO TRIGGER SCATTER TO NUMEROUS SHOWERS AND
THUNDERSTORMS TUE AFTERNOON. A GUIDANCE BLEND PUTS TEMPS NEAR
AVERAGE.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT MONDAY...FAIRLY GOOD MODEL CONSENSUS EXISTS THAT A
DIGGING TROUGH WILL CLOSE OFF AN UPPER LEVEL LOW PRESSURE CENTER IN
OR NEAR THE SOUTHERN APPALCHIANS TUESDAY. AN ASSOCIATED SFC COLD
FRONT WILL MOVE INTO THE AREA FROM THE WEST ON TUESDAY AS WELL...BUT
WITH THE CONTRAST ALONG THE BOUNDARY SLOWLY BEING LOST THROUGH THE
DAY. NUMEROUS MTN TO SCATTERED PIEDMONT CONVECTIVE COVERAGE EARLY
SHOULD STEADILY INCREASE TO NUMEROUS COVERAGE THROUGHOUT DURING THE
AFTN AND EARLY EVENING HOURS. MODEL PROFILES SUGGEST THAT WINDS WILL
BE FAIRLY LIGHT UP THE COLUMN WITH THE PASSAGE OF THE BEST UPPER
SUPPORT. LAPSE RATES WILL STEEPEN A BIT...BUT WITH THE COLDEST POOL
OF 500 MB TEMPS ALOFT PASSING BY JUST SE OF THE AREA. THE SEVERE
WEATHER POTENTIAL...THEREFORE...IS NOT TERRIBLY IMPRESSIVE.
THE UPPER LOW CENTER WILL LIFT SLOWLY NORTHEASTWARD TUE NIGHT
THROUGH WED AND GRADUALLY FILL. LOW LEVEL FLOW WILL RETURN TO
SOUTHERLY AND BOUNDARY LAYER MOISTURE SHOULD LINGER ENOUGH TO PERMIT
SCATTERED CONVECTIVE COVERAGE TO RETURN WED AFTN AND EVENING.
TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE
PERIOD.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 AM EDT MONDAY...AS THE FILLING LOW PRES SYSTEM PULLS AWAY
TO THE NE ON THU...LOW LEVEL SW FLOW WILL PERSIST ACROSS THE REGION
AND HEIGHTS WILL START RISING ALOFT. TEMPERATURES SHOULD WARM INTO
THE MID 80S MOST LOCATIONS OUTSIDE OF THE MTNS THU AFTN...WITH SOME
LOWER 80S IN THE LOWER MTN VALLEYS. ISOLATED...MAINLY MTN...DIURNAL
POPS ARE INDICATED IN THE WARM AIRMASS. DOMINANT RIDGING WILL THEN
START BUILDING OVER THE ERN CONUS ON FRI...WITH TEMPERATURES GAINING
ANOTHER CATEGORY BY FRIDAY AFTN. VERY LITTLE CAPE IS EVIDENT IN THE
WARM PROFILES ALOFT...BUT LINGERING BL MOISTURE WILL WARRANT A
SLIGHT CHC TSTM MENTION ALONG THE HIGHER TERRAIN FRI AFTN/EVENING.
STRONG HIGH PRESSURE WILL COME TO DOMINATE THE ENTIRE ERN CONUS BY
SAT...WITH MAXES AS MUCH AS 10 DEGREES ABOVE NORMAL. ISOLD TO SCT
RIDGE TOP CONVECTION WILL ONCE AGAIN BE POSSIBLE LATE IN THE DAY.
850 MB TEMPS MAY THEN COOL VERY SLIGHTLY ON SUNDAY AS THE RIDGE
RETROGRADES WEST...BUT TEMPS WILL STAY WELL ABOVE AVERAGE. ANOTHER
ROUND OF ISOLATED DIURNALLY DRIVEN MOUNTAIN CONVECTION WILL BE
POSSIBLE UNDER THE RIDGE SUNDAY AFTN. CONVECTIVE INITIATION MAY
FOCUS SLIGHTLY MORE TOWARD THE ERN SLOPES IF AN EASTERLY COMPONENT
IN THE BOUNDARY LAYER FLOW DEVELOPS UNDER THE RIDGE AS EXPECTED.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AT KCLT...MAIN QUESTION FPR THE NEAR TERM IS WHETHER ANY CONVECTION
WILL AFFECT THE AIRFIELD LATE THIS AFTERNOON INTO EARLY EVENING. THE
HRRR SUGGESTS THAT THERE WILL BE SCATTERED CONVECTION IN THE
VICINITY OF THE AIRFIELD CIRCA 00Z. FOR NOW WILL JUST HAVE A VCSH
FROM 00Z-02Z. FOR THE OVERNIGHT JUST A MID LEVEL CEILING IS EXPECTED
WITH PERHAPS SOME LIGHT FOG AROUND DAYBREAK RESTRICTING THE VSBY TO
AROUND 5SM. LOOKS LIKE TUE`S CONVECTION SHOULD HOLD OFF UNTIL AFTER
THE END OF THIS TAF PERIOD.
ELSEWHERE...SCT TO NUMEROUS SHOWERS/THUNDERSTORMS ARE FORECAST TO
DEVELOP OVER THE MOUNTAINS BY 20Z. WILL CARRY A TEMPO AT KAVL FOR
THUNDER AND MVFR RESTRICTIONS FROM 20-22Z. MESOSCALE MODELS SUGGEST
THAT CONVECTION WILL MOVE INTO THE FOOTHILLS/PIEDMONT LATE THIS
AFTERNOON AND EVENING. HENCE...WUILL CARRY A VCTS AT KHKY AND KGSP.
THE PREPONDERANCE OF GUIDANCE IS FORCASTING AT LEAST MVFR VSBY
RESTRICTIONS IN FOG AROUND DAYBREAK TUE...WITH IFR POSSIBLE AT KAVL.
CONVECTION WILL GET AN EARLY START ON TUE WITH A CHANCE OF THUNDER
AT KAVL BY 18Z.
OUTLOOK...SHOWER AND TSTM CHANCES WILL DIMINSH DIURNALLY TUE NIGHT
BUT RE-DEVELOP AGAIN WED AFTERNOON MOST AREAS. DIURNAL
THUNDERSTORMS TOWARD THE END OF THE WEEK WILL BE MORE LIKELY
CONFINED TO THE MOUNTAINS AND FOOTHILLS. EARLY MORNING
RESTRICTIONS DUE TO FOG ARE A GOOD BET MAINLY IN THE MOUNTAIN
VALLEYS EACH MORNING.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...LG
SHORT TERM...HG
LONG TERM...HG
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
445 PM CDT MON MAY 21 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE STRETCHING FROM TEXAS TO WESTERN ONTARIO THIS AFTERNOON.
MID AND HIGH CLOUDS ARE ADVANCING TO THE EAST OVER THE NORTHERN
PLAINS AND INTO THE NORTHERN MISSISSIPPI VALLEY...BUT DRY AIR ACROSS
THE REGION IS DISSIPATING THE CLOUDS ON THE LEADING EDGE. MUCH
COOLER AND DRIER CONDITIONS ARE PRESENT ACROSS THE REGION TODAY WITH
ONLY SOME DIURNAL CU DEVELOPING OVER EASTERN WISCONSIN. WITH A DRY
AIRMASS IN PLACE...TEMPS AND FROST HEADLINES ARE THE MAIN FORECAST
CONCERNS.
TONIGHT...HIGH PRESSURE WILL BE DRAPED ACROSS THE REGION
TONIGHT...WHICH WILL KEEP A DRY AIRMASS IN PLACE BELOW 700MB.
THETAE ADVECTION ABOVE THIS LEVEL MAY BRING FEW/SCT CLOUDS FROM THE
NORTHERN MISSISSIPPI VALLEY INTO NORTH-CENTRAL WISCONSIN...THOUGH
IMPACT ON TEMPS SHOULD BE MINIMAL. GOOD RADIATIVE COOLING
CONDITIONS WILL SUPPORT TEMPS FALLING FROM THE MID 30S NORTH TO LOW
40S SOUTH. TEMPS WILL FALL LOCALLY COOLER WITHIN THE SANDY SOIL
AREAS OF NORTH-CENTRAL AND FAR NORTHEAST WISCONSIN WHERE TEMPS MAY
EVEN FALL TO THE UPPER 20S. WILL HOIST A FROST ADVISORY NORTH OF A
LINCOLN TO NORTHERN MARINETTE LINE.
TUESDAY...HIGH PRESSURE WILL DRIFT FROM EASTERN WISCONSIN TO THE
CENTRAL GREAT LAKES. RELATIVELY THIN MID AND HIGH CLOUDS WILL MOVE
OVERHEAD DURING THE COURSE OF THE DAY...WHICH SHOULD KEEP SKY
CONDITIONS MOSTLY CLEAR TO PARTLY CLOUDY. A WARM FRONT WILL BE
STRETCHED ALONG THE US-CANADIAN BORDER AND PRECIP CHANCES SHOULD
REMAIN NORTHWEST OF THE FORECAST AREA. 925MB TEMPS ARE A DEGREE OR
TWO WARMER TOMORROW...SO WILL GO WITH HIGHS IN THE LOW TO MID 70S.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY.
MAIN FORECAST CHALLENGE FOR THIS PERIOD IS TRYING TO ADD SOME
RESOLUTION TO THE VARIOUS PCPN CHANCES STARTING LATER THIS
WEEK...ALONG WITH ADJUSTING ANY MAX TEMPS DUE TO VARIOUS SOLUTIONS
OF BOUNDARY LOCATIONS.
SURFACE HIGH PRESSURE WITH UPPER RIDGE WILL CONTINUE TO PROVIDE
QUIET WEATHER TO THE AREA TUESDAY NIGHT INTO THURSDAY FOR MOST
LOCATIONS. CONVECTION WILL BE CONFINED TO THE NORTHWEST STATES
AND NORTHERN PLAINS AS A BROAD UPPER TROUGH SETTLES INTO THIS
AREA. WILL CONFINE ANY SMALL PCPN MENTION AND MORE CLOUDS WEST OF
A RHI TO AUW LINE DUE TO THE POSSIBILITY OF ANY NORTHERN PLAINS
CONVECTION BRUSHING NORTHWEST WISCONSIN.
WILL THEN FOCUS ON THE HIGHER END CHC POPS FOR THE THURSDAY NIGHT
INTO FRIDAY MORNING PERIOD AS A SHORT WAVE SLIDES OVER THE STATE
WITH SURFACE FROPA. WILL DIMINISH PCPN LATER FRIDAY BUT STILL
UNKNOWN HOW FAR SOUTH THE FRONT WILL SETTLE AS THE UPPER FLOW
REMAINS SOUTHWEST. WILL ALSO KEEP CHC POPS GOING DUE TO A BAROCLINIC
ZONE LINGERING OVER THE STATE IN THE COOL SECTOR. WITH COOLER
TEMPS AND LITTLE INSTABILITY...DOWNPLAYED TSRA MENTION TO SHOWERS
FRIDAY NIGHT. INSTABILITY INCREASES AGAIN LATER SATURDAY. MEDIUM
MODEL RUNS BEGINNING TO SHOW SOME CONSENSUS OF THE FRONTAL
BOUNDARY LIFTING NORTH AGAIN IN RESPONSE TO THE WESTERN STATES
TROUGH DEEPENING AND EASTERN STATES UPPER RIDGE BUILDING. AGAIN
ANOTHER WAVE WITH FRONTAL SYSTEM ATTEMPTS TO SLIDE OVER THE REGION
LATER SUNDAY NIGHT INTO MONDAY FOR A FIRST STAB AT THE TIMING.
WENT WITH COOLER TEMPS SATURDAY WITH LAGGING BAROCLINIC ZONE BUT
WARMER SUNDAY MAX TEMPS AS UPPER HEIGHTS BUILD AND THE FRONT LIFTS
NORTH AS A WARM FRONT.
&&
.AVIATION...FOR 00Z TAF ISSUANCE. VFR CONDITIONS EXPECTED
THROUGH THE NEXT 24 HRS AS SFC RIDGE SLOWLY CROSSES THE RGN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 2 AM TO 7 AM CDT TUESDAY FOR WIZ005-010>013-
018-019-021.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
325 PM CDT MON MAY 21 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
325 PM CDT MON MAY 21 2012
MAIN FORECAST CONCERNS ARE FROST POTENTIAL TONIGHT AND PRECIPITATION
CHANCES AS WELL AS TEMPERATURES WEDNESDAY INTO THURSDAY.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING FROM THE DESERT SOUTHWEST INTO ALBERTA AND WEAK
TROUGHING OVER THE WESTERN GREAT LAKES REGION. HIGH PRESSURE
DOMINATES AT THE SURFACE ON THE BACK SIDE OF THE WEAK TROUGHING...
ENCOMPASSING THE ENTIRE FORECAST AREA. DRY AIR...SEEN ON THE 12Z
MPX...GRB AND DVN SOUNDINGS HAS RESULTED IN A SUNNY DAY ACROSS THE
FORECAST AREA. MIXING UP THROUGH 850MB WHERE TEMPS ARE AROUND 6C HAS
YIELDED TEMPERATURES MAINLY IN THE 70S...AND DEWPOINTS MOSTLY DOWN
INTO THE LOW TO MID 30S. TO THE WEST...AN AREA OF MID LEVEL CLOUDS
HAVE BEEN EXPANDING ACROSS NORTH DAKOTA AND INTO WESTERN MINNESOTA.
THESE CLOUDS ARE IN RESPONSE TO WARM ADVECTION AND MOISTURE RETURN
ON THE BACK SIDE OF THE SURFACE HIGH AND AHEAD OF THE UPPER RIDGE
AXIS. THERE WAS A LITTLE LIGHT SHOWER ACTIVITY ON THE WESTERN SIDE
OF THE CLOUDS...ASSOCIATED WITH 305 K ISENTROPIC LIFT...BUT THIS HAS
SINCE DISSIPATED. 12Z SOUNDINGS SHOWED MUCH WARMER AIR OVER THE
DAKOTAS...WITH 850MB TEMPS OF 10-15C ON AVERAGE WITH RAPID CITY AT
19C.
TONIGHT AND TUESDAY...UPPER RIDGING OVER THE NORTHERN ROCKIES WILL
SHIFT EAST INTO THE FORECAST AREA ON TUESDAY...PUSHED ALONG BY
TROUGHING CURRENTLY OFF THE PACIFIC NORTHWEST MOVING INLAND. IN
RESPONSE...A SURFACE LOW DEEPENS ACROSS THE DAKOTAS...INCREASING THE
WARM ADVECTION DOWNSTREAM INTO THE FORECAST AREA. WITH THIS WARM
ADVECTION WE SHOULD SEE SOME OF THOSE MID CLOUDS OVER WESTERN
MINNESOTA MOVE ACROSS. TRENDS IN MODEL RH FIELDS SUGGEST SOME
DISSIPATION OF THE MID CLOUDS AS THEY PUSH EAST...ESPECIALLY DURING
THE DAY TUESDAY. THIS MATCHES THE PREVIOUS FORECAST. IN ADDITION...
IT APPEARS MOST OF THE MID CLOUDS WILL STAY WEST OF THE MISSISSIPPI
RIVER TONIGHT. THIS IS CRITICAL BECAUSE THE SURFACE RIDGE SHOULD BE
CENTERED OVER WISCONSIN MUCH OF TONIGHT...LEADING TO FAVORABLE
RADIATIONAL COOLING CONDITIONS. SINCE BLACK RIVER FALLS AND SPARTA
DROPPED INTO THE LOW TO MID 30S LAST NIGHT...SEE NO REASON WHY THAT
WILL NOT HAPPEN AGAIN. THIS MEANS THAT OUR TYPICAL WISCONSIN COLD
SPOTS COULD SEE SOME FROST. NOT ENOUGH OF AN EXPANSIVE AREA OF COLD
TEMPS IS FORECAST TO WARRANT A FROST ADVISORY...THOUGH. WEST OF THE
MISSISSIPPI RIVER...INCREASING WINDS SHOULD ALLOW TEMPERATURES TO
STAY WARMER THERE. WITH INCREASING SUNSHINE AND SOUTHERLY WINDS ON
TUESDAY...AS WELL AS 850MB TEMPS CLIMBING TO AROUND 10C BY
18Z...SHOULD ALLOW FOR HIGHS WELL INTO THE 70S. WARMEST TEMPS LIKELY
WEST.
TUESDAY NIGHT AND WEDNESDAY...THE UPPER TROUGHING OVER THE NORTHWEST
U.S. IS PROGGED TO DEEPEN DURING THIS PERIOD. A FAIRLY POTENT
SHORTWAVE EJECTING OUT OF THIS TROUGH THROUGH THE DAKOTAS WILL CAUSE
THE LOW PRESSURE AREA THERE TO LIFT INTO NORTHWEST ONTARIO BY 00Z
THURSDAY. ITS ASSOCIATED COLD FRONT APPEARS TO BE TRENDING
SLOWER...NOW ONLY REACHING WESTERN MINNESOTA BY 00Z THURSDAY. THE
ECMWF HAS BEEN SUGGESTING THIS FOR QUITE AWHILE. ONLY MODEL THAT HAS
THE FRONT APPROACHING THE FORECAST AREA IS THE 21.12Z NAM...AND EVEN
IT HAS TRENDED SLOWER FROM ITS PREVIOUS RUNS. THEREFORE...HAVE
CONSIDERED THE NAM A FAST OUTLIER. ANY CONVECTION IS LIKELY TO BE
HIGHLY TIED TO THE FRONT...GIVEN CAPPING PRESENT IN THE WARM SECTOR
AHEAD OF IT. THEREFORE...HAVE DRIED OUT MUCH OF THE FORECAST EXCEPT
FOR A SMALL AREA IN SOUTHEAST MINNESOTA WHICH IS CLOSEST TO THE
FRONTAL BOUNDARY. THESE SMALL CHANCES MAY BE ABLE TO BE PULLED IN
LATER FORECASTS. A BREEZY SOUTH WIND WILL HELP KEEP TEMPERATURES UP
TUESDAY NIGHT INTO THE 50S IN MOST LOCATIONS. SOME OF SOUTHEAST MN
MAY NOT DROP BELOW 60...MEANWHILE THE COLD SPOTS OF WISCONSIN COULD
DECOUPLE AND DROP INTO THE UPPER 40S. MUCH WARMER 850MB TEMPS ARE
PROGGED FOR WEDNESDAY...ON THE ORDER OF 16-18C. NORMALLY THIS COULD
PRODUCE HIGHS OF 85 TO 90. HOWEVER...THERE IS INCREASING CIRRUS
THROUGH THE DAY TO TEMPER HIGHS SOMEWHAT.
WEDNESDAY NIGHT AND THURSDAY...ANOTHER SURFACE LOW IS PROGGED TO
FORM OVER SOUTHEAST COLORADO LATE WEDNESDAY. A POTENT SHORTWAVE
EJECTING OUT OF THE DEEPENING WESTERN TROUGH WILL LIFT THIS LOW
NORTHEAST...RIDING UP THE COLD FRONT AND CROSSING CENTRAL MINNESOTA
ON THURSDAY. THE 21.12Z GFS/UKMET BOTH DEPICT SOME QPF WEDNESDAY
NIGHT OVER WISCONSIN...BUT THESE SEEM ODD GIVEN OUR FORECAST AREA IS
UNDERNEATH THE MAIN MOISTURE TRANSPORT STREAM WITHOUT MOISTURE
CONVERGENCE...AS WELL AS CAPPING ALOFT TO ELEVATED CONVECTION.
THEREFORE...FOR WEDNESDAY NIGHT...KEPT ALL PRECIPITATION CHANCES
OVER FAR NORTHWEST SECTIONS OF THE FORECAST AREA. THESE CHANCES ARE
STILL LOW...20-30...BECAUSE THE FRONTOGENETICAL ZONE ASSOCIATED WITH
THE COLD FRONT LOOKS TO STAY ACTIVE ALONG AND NORTHWEST OF
IT...WHICH KEEPS THE BULK OF THE PRECIPITATION MORE FROM SOUTHWEST
MINNESOTA INTO THE DULUTH AREA. BETTER SHOT EXISTS FOR THE COLD
FRONT TO COME IN ON THURSDAY...IN THIS CASE ASSOCIATED WITH THE NEW
LOW COMING UP. THE 21.12Z GFS REMAINS THE FASTEST MODEL TO DO
SO...WITH THE ECMWF AND ESPECIALLY GEM SUGGESTING SLOWER. LEANED
TOWARDS THE SLOWER PASSAGE...WHICH KEEPS ALL PRECIPITATION CHANCES
OVER THE NORTHWEST HALF OF THE FORECAST AREA. TEMPERATURES BOTH
WEDNESDAY NIGHT AND ESPECIALLY THURSDAY HAVE BEEN WARMED UP...DUE TO
THE SLOWER FRONTAL PASSAGE AND MAINTAINING A LONGER PERIOD OF BREEZY
SOUTH WINDS. THURSDAY COULD TOUCH 90...ESPECIALLY IN THE SOUTHEAST
WHERE MORE SUN IS PRESENT TO COMBINE WITH 850MB TEMPS UP POSSIBLY
NEAR 20C.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
325 PM CDT MON MAY 21 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES AND WHEN THE
HEAT UP WILL COME.
MODELS ARE BECOMING IN MUCH BETTER AGREEMENT ON THE LONG TERM
FORECAST...SO CONFIDENCE IS INCREASING ON WHAT WILL HAPPEN. IN
GENERAL...TROUGHING LOOKS TO REMAIN IN THE WESTERN U.S....
INTENSIFYING BY SATURDAY MORNING. WITH THE DEEPENING TROUGH OUT
WEST...THE RESPONSE IS TO BUILD SOME PRETTY STRONG RIDGING TO THE
EAST. THEREFORE...AFTER WHAT LOOKS TO BE A COLD FRONTAL PASSAGE
THURSDAY NIGHT...THAT COLD FRONT WILL NOT BE ABLE TO DROP TOO FAR
SOUTH. MAINTAINED SOME CHANCES OF SHOWERS AND THUNDERSTORMS FOR
THURSDAY NIGHT...AND THESE MAY NEED TO BE INCREASED OVER WESTERN
SECTIONS WITH A SHORTWAVE PROGGED TO COME OUT. IN FACT...IF THE
21.12Z ECMWF/GEM ARE CORRECT...SOME OF THE STORMS THURSDAY NIGHT
COULD BE SEVERE. WESTERN SECTIONS OF THE AREA LOOK TO GET A BREAK
FROM PRECIPITATION ON FRIDAY WITH THE FRONT PASSED...BUT STILL
MAINTAINED A CHANCE ELSEWHERE SINCE THE FRONT IS STILL MOVING
THROUGH. DEFINITELY COOLER ON FRIDAY BEHIND THE FRONT...BUT STILL
SEASONABLE. FRONT SHOULD LAY UP IN SOUTHERN IOWA FRIDAY NIGHT AND
THEN BEGIN TO RETREAT NORTH AS A WARM FRONT AS THE UPPER RIDGE
STRENGTHENS. MOISTURE TRANSPORT NORTH OF THE FRONT COULD YIELD
CONVECTION FRIDAY NIGHT THROUGH SATURDAY. CANNOT RULE OUT SOME OF
THIS BEING SEVERE TOO. 850MB TEMPS CLIMB TO 20C OR HIGHER SOUTH OF
THE FRONT...WHICH MEANS ON SATURDAY THERE IS POTENTIAL FOR A 20
DEGREE OR MORE SPREAD ACROSS THE FORECAST AREA.
MODELS AGREE THAT THE WESTERN TROUGH BEGINS EJECTING OUT SATURDAY
NIGHT...ALLOWING THE RIDGE AND WARM SECTOR TO BUILD OVER THE
FORECAST AREA. THIS MEANS THE CONVECTION SHOULD SLOWLY SHIFT
NORTH...ALLOWING FOR HEAT AND LIKELY SOME HUMIDITY TO MOVE IN.
RAISED HIGHS ON SUNDAY TO THE MID 80S TO NEAR 90...BUT FURTHER
INCREASES COULD BE NEEDED. SAME GOES FOR LOWS SATURDAY NIGHT AND
SUNDAY NIGHT WHERE POTENTIAL EXISTS FOR TEMPERATURES TO NOT DIP
BELOW 70. LAST ISSUE IS A COLD FRONT PROGGED TO COME AT THE AREA FOR
SUNDAY NIGHT AND MONDAY...ASSOCIATED WITH THE EJECTING WESTERN
TROUGH. THE GFS IS THE FASTEST ON THIS FRONT...WHEREAS THE 21.12Z
ECMWF HAS SLOWED DOWN FROM ITS PREVIOUS RUN. FOR NOW HAVE FOLLOWED A
CONSENSUS AND INCLUDED 20-40 PERCENT CHANCES FOR SUNDAY NIGHT AND
MONDAY. HOWEVER...WOULD NOT BE SURPRISED IF THE SLOWER FRONTAL
TIMING PANS OUT...RESULTING IN A WARMER AND DRIER FORECAST.
IN SUMMARY...SOME POTENTIAL FOR SEVERE STORMS THURSDAY NIGHT AND
FRIDAY NIGHT/SATURDAY...THEN HEATING UP FOR THE END OF MEMORIAL DAY
WEEKEND.
&&
.AVIATION...THROUGH 18Z TUESDAY
1233 PM CDT MON MAY 21 2012
HIGH PRESSURE WILL BE ENTRENCHED ACROSS THE UPPER MIDWEST REGION THROUGH
TUESDAY MORNING AND PROVIDE LIGHT WINDS AND VFR CONDITIONS AT BOTH
RST AND LSE TAF SITES. AS THE HIGH PRESSURE SYSTEM BUILDS EAST OF
THE AREA...THE PRESSURE GRADIENT BEGINS TO TIGHTEN AND ALLOWS FOR
SOUTHERLY WINDS TO INCREASE...ESPECIALLY OVER SOUTHEAST MINNESOTA
AND NORTHEAST IOWA. WIND SPEEDS ARE EXPECTED TO BE AROUND 15 KNOTS
WITH GUSTS UP TO 23 KNOTS AT KRST BY 14Z TUESDAY AND SUSTAINED AT
12 KNOTS AT LSE BY 15Z TUESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
325 PM CDT MON MAY 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
218 PM CDT MON MAY 21 2012
.SHORT TERM...TONIGHT AND TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE STRETCHING FROM TEXAS TO WESTERN ONTARIO THIS AFTERNOON.
MID AND HIGH CLOUDS ARE ADVANCING TO THE EAST OVER THE NORTHERN
PLAINS AND INTO THE NORTHERN MISSISSIPPI VALLEY...BUT DRY AIR ACROSS
THE REGION IS DISSIPATING THE CLOUDS ON THE LEADING EDGE. MUCH
COOLER AND DRIER CONDITIONS ARE PRESENT ACROSS THE REGION TODAY WITH
ONLY SOME DIURNAL CU DEVELOPING OVER EASTERN WISCONSIN. WITH A DRY
AIRMASS IN PLACE...TEMPS AND FROST HEADLINES ARE THE MAIN FORECAST
CONCERNS.
TONIGHT...HIGH PRESSURE WILL BE DRAPED ACROSS THE REGION
TONIGHT...WHICH WILL KEEP A DRY AIRMASS IN PLACE BELOW 700MB.
THETAE ADVECTION ABOVE THIS LEVEL MAY BRING FEW/SCT CLOUDS FROM THE
NORTHERN MISSISSIPPI VALLEY INTO NORTH-CENTRAL WISCONSIN...THOUGH
IMPACT ON TEMPS SHOULD BE MINIMAL. GOOD RADIATIVE COOLING
CONDITIONS WILL SUPPORT TEMPS FALLING FROM THE MID 30S NORTH TO LOW
40S SOUTH. TEMPS WILL FALL LOCALLY COOLER WITHIN THE SANDY SOIL
AREAS OF NORTH-CENTRAL AND FAR NORTHEAST WISCONSIN WHERE TEMPS MAY
EVEN FALL TO THE UPPER 20S. WILL HOIST A FROST ADVISORY NORTH OF A
LINCOLN TO NORTHERN MARINETTE LINE.
TUESDAY...HIGH PRESSURE WILL DRIFT FROM EASTERN WISCONSIN TO THE
CENTRAL GREAT LAKES. RELATIVELY THIN MID AND HIGH CLOUDS WILL MOVE
OVERHEAD DURING THE COURSE OF THE DAY...WHICH SHOULD KEEP SKY
CONDITIONS MOSTLY CLEAR TO PARTLY CLOUDY. A WARM FRONT WILL BE
STRETCHED ALONG THE US-CANADIAN BORDER AND PRECIP CHANCES SHOULD
REMAIN NORTHWEST OF THE FORECAST AREA. 925MB TEMPS ARE A DEGREE OR
TWO WARMER TOMORROW...SO WILL GO WITH HIGHS IN THE LOW TO MID 70S.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY.
MAIN FORECAST CHALLENGE FOR THIS PERIOD IS TRYING TO ADD SOME
RESOLUTION TO THE VARIOUS PCPN CHANCES STARTING LATER THIS
WEEK...ALONG WITH ADJUSTING ANY MAX TEMPS DUE TO VARIOUS SOLUTIONS
OF BOUNDARY LOCATIONS.
SURFACE HIGH PRESSURE WITH UPPER RIDGE WILL CONTINUE TO PROVIDE
QUIET WEATHER TO THE AREA TUESDAY NIGHT INTO THURSDAY FOR MOST
LOCATIONS. CONVECTION WILL BE CONFINED TO THE NORTHWEST STATES
AND NORTHERN PLAINS AS A BROAD UPPER TROUGH SETTLES INTO THIS
AREA. WILL CONFINE ANY SMALL PCPN MENTION AND MORE CLOUDS WEST OF
A RHI TO AUW LINE DUE TO THE POSSIBILITY OF ANY NORTHERN PLAINS
CONVECTION BRUSHING NORTHWEST WISCONSIN.
WILL THEN FOCUS ON THE HIGHER END CHC POPS FOR THE THURSDAY NIGHT
INTO FRIDAY MORNING PERIOD AS A SHORT WAVE SLIDES OVER THE STATE
WITH SURFACE FROPA. WILL DIMINISH PCPN LATER FRIDAY BUT STILL
UNKNOWN HOW FAR SOUTH THE FRONT WILL SETTLE AS THE UPPER FLOW
REMAINS SOUTHWEST. WILL ALSO KEEP CHC POPS GOING DUE TO A BAROCLINIC
ZONE LINGERING OVER THE STATE IN THE COOL SECTOR. WITH COOLER
TEMPS AND LITTLE INSTABILITY...DOWNPLAYED TSRA MENTION TO SHOWERS
FRIDAY NIGHT. INSTABILITY INCREASES AGAIN LATER SATURDAY. MEDIUM
MODEL RUNS BEGINNING TO SHOW SOME CONSENSUS OF THE FRONTAL
BOUNDARY LIFTING NORTH AGAIN IN RESPONSE TO THE WESTERN STATES
TROUGH DEEPENING AND EASTERN STATES UPPER RIDGE BUILDING. AGAIN
ANOTHER WAVE WITH FRONTAL SYSTEM ATTEMPTS TO SLIDE OVER THE REGION
LATER SUNDAY NIGHT INTO MONDAY FOR A FIRST STAB AT THE TIMING.
WENT WITH COOLER TEMPS SATURDAY WITH LAGGING BAROCLINIC ZONE BUT
WARMER SUNDAY MAX TEMPS AS UPPER HEIGHTS BUILD AND THE FRONT LIFTS
NORTH AS A WARM FRONT.
&&
.AVIATION...HIGH PRESSURE WILL MOVE ACROSS THE REGION OVER THE NEXT
24 HOURS. OTHER THAN AREAS OF FROST DEVELOPING LATE TONIGHT OVER
PARTS OF CENTRAL AND MOST OF NORTH-CENTRAL WISCONSIN...A SCT
MID-DECK WILL ARRIVE LATE TONIGHT INTO TOMORROW.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 2 AM TO 7 AM CDT TUESDAY FOR WIZ005-010>013-
018-019-021.
&&
$$
MPC/TDH