Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 04/22/12
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1222 AM CDT FRI APR 20 2012
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION BELOW...
&&
.AVIATION...
THE SHRA/TSRA ONGOING ALONG COLD FRONT...CURRENTLY LOCATED FROM
SW MO INTO SOUTH CENTRAL OK...WILL MOVE SE INTO NWRN SECTIONS OF
THE STATE THIS MORNING. EXPECT CHANCES OF SHRA/TSRA TO PERSIST
ALONG AND AHEAD OF THIS FRONT AS IT PROGRESSES SE ACROSS THE STATE
THROUGH LATE THIS AFTERNOON. SOME MVFR CONDITIONS WILL BE POSSIBLE
UNDER THIS PRECIP ACTIVITY...WITH LESSER CONDITIONS UNDER STRONGER
THUNDERSTORMS. WINDS WILL SWITCH FROM THE SOUTH TO THE WEST AND NW
BEHIND THE FRONT. SOME GUSTS COULD BE SEEN BEHIND THE FRONT...WITH
GUSTS AROUND 20 KTS POSSIBLE. PRECIP ACTIVITY SHOULD MOVE OUT OF
THE STATE BY FRI EVENING AS THE FRONT MOVES TO THE SE OF AR.
&&
.PREV DISCUSSION... /ISSUED 914 PM CDT THU APR 19 2012/
UPDATE...
JUST SOME MINOR TWEAKS TO THE FORECAST FOR THE OVERNIGHT PERIOD.
SCATTERED THUNDERSTORMS HAVE DEVELOPED ALONG A FRONT IN CENTRAL
OKLAHOMA THIS EVENING...AND EXTEND NORTHEAST TO NEAR TULSA. RAPID
REFRESH RUC GUIDANCE SUGGESTS CONVECTION WILL CONTINUE ALONG THE
FRONT AND WILL EXPAND SOMEWHAT AS IT MOVES TOWARDS ARKANSAS. THIS
WOULD PUT SOME SHOWERS AND ISOLATED TSTMS IN THE NORTHWEST
COUNTIES BY AROUND DAYBREAK. HOWEVER...RUC GUIDANCE SUGGESTS MORE
DOMINANT/WIDESPREAD AREA OF PRECIP WILL APPROACH SOUTHWEST
ARKANSAS A FEW HOURS AFTER DAWN THANKS IN PART TO STRONGER SFC LOW
ALONG THE FRONT IN NE TEXAS. AS SUCH...LOWERED POPS JUST A TAD IN
THE NORTHWEST AFTER 12Z. STILL HAVE HIGH CHANCE VALUES UP
THERE...BUT LEFT THE LIKELY VALUES CONFINED TO AREAS SOUTH OF THE
I-40 CORRIDOR AND WEST OF CLARKSVILLE.
PER THE RUC AND LATEST 12KM NAM GUIDANCE...PRECIP WILL LIKELY
SLACKEN A BIT BETWEEN 12Z-18Z BUT WILL THEN PICK UP IN COVERAGE
AND INTENSITY DURING THE AFTERNOON HOURS. NORTHERN AREAS MAY NOT
SEE MUCH OUTSIDE OF SOME SHORT SPITS OF RAIN OR DRIZZLE FROM MID
TO LATE MORNING IF THE NAM VERIFIES. DECIDED NOT TO TRY AND TIME
SUCH DRY PERIODS THOUGH AND LEFT THE LATE MORNING AND
AFTERNOON/EVENING POP FORECASTS FOR TOMORROW ALONE.
OTHERWISE...FORECAST APPEARS TO BE ON TRACK AND NO OTHER CHANGES
WERE MADE.
PREV DISCUSSION... /ISSUED 240 PM CDT THU APR 19 2012/
SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
HIGH PRES RDG WAS SITUATED JUST E OF THE FA THIS AFTN...WITH A
GENERAL SELY WIND FLOW NOTED. WITH FAIRLY DRY AIR STILL IN PLACE
ACRS THE REGION...ABUNDANT SUNSHINE ALLOWED MID AFTN TEMPS TO CLIMB
INTO THE MID AND UPR 70S. MEANWHILE...LOW PRES CONTD TO DVLP OVR THE
SRN PLAINS AND WL EVENTUALLY AFFECT THE MID SOUTH OVR THE NEXT 24 TO
36 HRS.
MOISTURE LVLS WL START TO INCRS SIGNIFICANTLY FM THE W TNGT AND FRI
AS THE AFOREMENTIONED STORM SYS MOVES CLOSER TO AR. ASSOCD CDFNT
RMNS PROGGED TO ENTER NWRN AR FRI MRNG AND MOVE THRU THE REST OF THE
STATE BY FRI EVENING. A BAND OF MAINLY POST-FNTL SHRA/EMBEDDED TSRA
WL ACCOMPANY THE BNDRY...WITH A GENERAL 1/2 TO ONE INCH OF QPF
EXPECTED. PARTS OF SERN AR COULD SEE LOCALLY HIGHER AMTS.
CANNOT RULE OUT SOME LINGERING RAIN CHCS ACRS PARTS OF FAR SERN AR
EARLY ON SAT. OTHERWISE...NWLY WINDS WL USHER COOLER AND DRIER AIR
INTO THE REGION. TEMPS WL TREND DOWN TO BLW NORMAL LVLS IN THE
COMING DAYS.
LONG TERM...MONDAY THROUGH THURSDAY
RIDGING OVER THE HIGH PLAINS WILL PROVIDE NW UPR FLOW TO THE NATURAL
STATE FOR THE MAJORITY OF THE LONG TERM. THE NW FLOW WILL GRADUALLY
SHIFT EAST BY THURSDAY WHILE AT THE SAME TIME SFC HIGH PRESSURE
DRIFTS EAST OF THE STATE. THIS WILL ALLOW AN OVERALL WARMING TREND
THROUGH THE PD AS SRLY LOW LVL FLOW DEVELOPS.
OVERALL...VERY FEW CHANGES WERE MADE TO THE FCST AS PREDOMINATELY
DRY CONDS ARE EXPECTED. HOWEVER...GIVEN THAT NW UPR FLOW CAN AT
TIMES SURPRISE US WITH UNEXPECTED CLOUDS OR PRECIP DUE TO MODEL
UNDERFORECAST SHRTWVS...HAVE INCREASED CLOUD COVER FOR MUCH OF THE
MIDDLE PART OF THE WEEK GIVEN A FEW SHRTWVS DIVING INTO THE UPR
TROUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 44 63 43 72 / 50 10 0 0
CAMDEN AR 50 68 47 75 / 60 10 0 0
HARRISON AR 39 63 42 70 / 20 0 0 0
HOT SPRINGS AR 48 66 44 75 / 40 0 0 0
LITTLE ROCK AR 48 67 47 73 / 50 10 0 0
MONTICELLO AR 51 67 48 73 / 60 10 0 0
MOUNT IDA AR 47 66 43 75 / 30 0 0 0
MOUNTAIN HOME AR 40 64 42 71 / 20 0 0 0
NEWPORT AR 46 64 46 72 / 50 10 0 0
PINE BLUFF AR 50 66 47 73 / 60 10 0 0
RUSSELLVILLE AR 44 67 44 74 / 30 0 0 0
SEARCY AR 47 65 46 72 / 50 10 0 0
STUTTGART AR 49 66 48 73 / 60 10 0 0
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...62
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1005 AM MDT FRI APR 20 2012
.UPDATE...
&&
.SHORT TERM...SKIES HAVE CLEARED OUT NICELY OVER THE NORTHEAST
PLAINS THIS MORNING...WHILE CONSIDERABLE AMOUNT OF MOISTURE
REMAINS TRAPPED IN THE MOUNTAINS. WILL ADJUST CLOUD COVER TO
ACCOUNT FOR CLOUD TRENDS TODAY BUT SHOULD SEE SOME PARTIAL
CLEARING IN THE MOUNTAINS THIS AFTERNOON. OTHERWISE NO OTHER
ISSUES FOR TODAY.
.AVIATION...NO ISSUES TODAY WITH MOSTLY CLEAR SKIES WITH JUST A
FEW CUMULUS AROUND. SURFACE WINDS GENERALLY UNDER 12KT TODAY AND
CURRENTLY ARE SOUTHEAST AND SHOULD TREND TO THE EAST AND
NORTHEAST THIS AFTERNOON. THERE MAY BE SOME NW WINDS MIXING OUT
IN/NEAR THE FOOTHILLS BY LATE AFTERNOON BUT A BIT UNCLEAR IF THIS
WILL MAKE IT AS FAR EAST AS DEN/APA.
&&
.PREV DISCUSSION... /ISSUED 319 AM MDT FRI APR 20 2012/
SHORT TERM...INCREASING MID LEVEL QG DESCENT WILL BE OVER THE
CWFA THIS MORNING AS THE UPPER LEVEL JET SHIFTS TO THE EAST.
LINGERING SHOWERS OVER THE NORTHEAST PLAINS THIS MORNING ARE JET
INDUCED. THE HRRR AND RUC13 MDLS KILL OFF THE SHOWERS IN THE
12-15Z TIME FRAME SO WILL TREND THE FCST THAT WAY AS WELL. SOME
STRATUS HAS DEVELOPED AROUND THE DENVER AREA THIS MORNING
FOLLOWING THE FRONTAL PASSAGE. NOT MUCH IMMEDIATELY UPSTREAM SO DO
NOT EXPECT THE STRATUS TO LINGER FOR VERY LONG...SHUD SEE THE LOW
CLOUD LAYER START TO DECREASE AFTER 12Z. THERE WILL BE SOME
CLEARING LATER THIS MORNING BUT ENUF WEAK INSTBY THIS AFTERNOON
FOR CONVECTIVE CLOUD COVER TO REDEVELOP. WL GO WITH PRIMARILY
PARTLY CLOUDY FCST TODAY. SPATIAL CROSS-SECTIONS AND SIMULATED
STLT PRODUCTS APPEAR TO SUPPORT THIS THROUGH EARLY THIS EVENING.
CLEARING OVERNIGHT EXPECTED WITH SOME OCCASIONSL GUSTY DOWNSLOPE
WINDS ALONG THE FRONT RANGE FOOTHILLS OVERNIGHT
LONG TERM...AN UPPER LEVEL RIDGE WILL BE OVER THE AREA THRU THE
WEEKEND. THIS WILL LEAD TO MAINLY DRY CONDITIONS WITH ABV NORMAL
TEMPS. SOME MOISTURE MAY MOVE INTO THE MTNS ON SUN SO WILL MENTION
SOME ISOLD LATE AFTN/EVENING TSTMS OVER THE HIGHER TERRAIN. HIGHS
BOTH DAYS OVER NERN CO WILL BE IN THE 70S.
THE UPPER LEVEL RIDGE WILL REMAIN OVER THE AREA MON AND TUE
WITH CROSS-SECTIONS SHOWING LIMITED MOISTURE. ONCE AGAIN COULD SEE
SOME ISOLD CONVECTION OVER THE HIGHER TERRAIN IN THE LATE
AFTN/EARLY EVENING HOURS. HIGHS WILL REMAIN ABV NORMAL BOTH DAYS WITH
HIGHS POSSIBLY REACHING THE LOWER TO MID 80S ACROSS NERN CO BY
TUE.
FOR WED AND THU THERE IS NOT MUCH AGREEMENT BETWEEN THE ECMWF AND
THE GFS. THE ECMWF KEEPS A FLAT RIDGE OVER THE AREA WHILE THE GFS
SHOWS AN UPPER LEVEL LOW MOVING ACROSS SRN CO LATE WED INTO THU.
THE CANADIAN MODEL IS MORE IN LINE WITH THE ECMWF SO WILL TREND
FCST MORE TOWARDS THE ECMWF. THE ECMWF SHOWS A WK FNT MAY MOVE
INTO NERN CO ON WED WITH SOME INCREASE IN MOISTURE AS A WK
DISTURBANCE TRACKS ACROSS NRN CO BY WED AFTN OR NIGHT. THUS COULD
SEE AT LEAST A SLIGHT CHC OF AFTN/EVENING CONVECTION OVER NRN CO.
TEMPS ON WED MAY COOL DOWN BACK DOWN INTO THE 70S ACROSS NERN CO
BEHIND WK FNT. ON THU THE ECMWF STILL SHOWS ENOUGH MOISTURE AROUND
FOR A SLIGHT CHC OF AFN/EVENING CONVECTION OVER NRN CO WITH LITTLE
CHANGE TO TEMPS.
AVIATION...IFR/MVFR CIGS AROUND DENVER SHOULD START TO LIFT BY
12Z WITH VFR CONDITIONS AFTER 15Z. NORTHERLY WINDS THIS MORNING
WILL DECREASE AND BECOME MORE VARIABLE BY 15Z. AFTER 18Z WILL KEEP
THE MENTION OF AN E-SELY WIND IN THE TAFS FOR KDEN AND KAPA...
WITH A WEAK W-NWLY OR VRBL SFC WIND AT KBJC.
HYDROLOGY...NO PRECIPITATION IS EXPECTED FOR THE FOUR MILE
CANYON AREA TODAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....RPK
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
319 AM MDT FRI APR 20 2012
.SHORT TERM...INCREASING MID LEVEL QG DESCENT WILL BE OVER THE
CWFA THIS MORNING AS THE UPPER LEVEL JET SHIFTS TO THE EAST.
LINGERING SHOWERS OVER THE NORTHEAST PLAINS THIS MORNING ARE JET
INDUCED. THE HRRR AND RUC13 MDLS KILL OFF THE SHOWERS IN THE
12-15Z TIME FRAME SO WILL TREND THE FCST THAT WAY AS WELL. SOME
STRATUS HAS DEVELOPED AROUND THE DENVER AREA THIS MORNING
FOLLOWING THE FRONTAL PASSAGE. NOT MUCH IMMEDIATELY UPSTREAM SO DO
NOT EXPECT THE STRATUS TO LINGER FOR VERY LONG...SHUD SEE THE LOW
CLOUD LAYER START TO DECREASE AFTER 12Z. THERE WILL BE SOME
CLEARING LATER THIS MORNING BUT ENUF WEAK INSTBY THIS AFTERNOON
FOR CONVECTIVE CLOUD COVER TO REDEVELOP. WL GO WITH PRIMARILY
PARTLY CLOUDY FCST TODAY. SPATIAL CROSS-SECTIONS AND SIMULATED
STLT PRODUCTS APPEAR TO SUPPORT THIS THROUGH EARLY THIS EVENING.
CLEARING OVERNIGHT EXPECTED WITH SOME OCCASIONSL GUSTY DOWNSLOPE
WINDS ALONG THE FRONT RANGE FOOTHILLS OVERNIGHT
.LONG TERM...AN UPPER LEVEL RIDGE WILL BE OVER THE AREA THRU THE
WEEKEND. THIS WILL LEAD TO MAINLY DRY CONDITIONS WITH ABV NORMAL
TEMPS. SOME MOISTURE MAY MOVE INTO THE MTNS ON SUN SO WILL MENTION
SOME ISOLD LATE AFTN/EVENING TSTMS OVER THE HIGHER TERRAIN. HIGHS
BOTH DAYS OVER NERN CO WILL BE IN THE 70S.
THE UPPER LEVEL RIDGE WILL REMAIN OVER THE AREA MON AND TUE
WITH CROSS-SECTIONS SHOWING LIMITED MOISTURE. ONCE AGAIN COULD SEE
SOME ISOLD CONVECTION OVER THE HIGHER TERRAIN IN THE LATE
AFTN/EARLY EVENING HOURS. HIGHS WILL REMAIN ABV NORMAL BOTH DAYS WITH
HIGHS POSSIBLY REACHING THE LOWER TO MID 80S ACROSS NERN CO BY
TUE.
FOR WED AND THU THERE IS NOT MUCH AGREEMENT BETWEEN THE ECMWF AND
THE GFS. THE ECMWF KEEPS A FLAT RIDGE OVER THE AREA WHILE THE GFS
SHOWS AN UPPER LEVEL LOW MOVING ACROSS SRN CO LATE WED INTO THU.
THE CANADIAN MODEL IS MORE IN LINE WITH THE ECMWF SO WILL TREND
FCST MORE TOWARDS THE ECMWF. THE ECMWF SHOWS A WK FNT MAY MOVE
INTO NERN CO ON WED WITH SOME INCREASE IN MOISTURE AS A WK
DISTURBANCE TRACKS ACROSS NRN CO BY WED AFTN OR NIGHT. THUS COULD
SEE AT LEAST A SLIGHT CHC OF AFTN/EVENING CONVECTION OVER NRN CO.
TEMPS ON WED MAY COOL DOWN BACK DOWN INTO THE 70S ACROSS NERN CO
BEHIND WK FNT. ON THU THE ECMWF STILL SHOWS ENOUGH MOISTURE AROUND
FOR A SLIGHT CHC OF AFN/EVENING CONVECTION OVER NRN CO WITH LITTLE
CHANGE TO TEMPS.
&&
.AVIATION...IFR/MVFR CIGS AROUND DENVER SHOULD START TO LIFT BY
12Z WITH VFR CONDITIONS AFTER 15Z. NORTHERLY WINDS THIS MORNING
WILL DECREASE AND BECOME MORE VARIABLE BY 15Z. AFTER 18Z WILL KEEP
THE MENTION OF AN E-SELY WIND IN THE TAFS FOR KDEN AND KAPA...
WITH A WEAK W-NWLY OR VRBL SFC WIND AT KBJC.
&&
.HYDROLOGY...NO PRECIPITATION IS EXPECTED FOR THE FOUR MILE
CANYON AREA TODAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM....RPK
AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS ALBANY NY
1045 PM EDT SAT APR 21 2012
.SYNOPSIS...
MODERATE TO HEAVY RAINFALL IS ON THE WAY. A COLD FRONT
WILL GRADUALLY MOVE EAST OF THE AREA TONIGHT...WHICH WILL BRING THE
AREA ITS FIRST WIDESPREAD MEASURABLE RAINFALL SINCE APRIL FIRST. AN
INTENSIFYING AREA OF LOW PRESSURE WILL APPROACH FROM THE SOUTH
SUNDAY AND MOVE ACROSS THE REGION MONDAY BRINGING A SOAKING RAINFALL.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1030 PM...MODERATE TO EVEN LOCALIZED HEAVY RAIN HAS FALLEN
ACROSS
PORTIONS OF EASTERN NEW YORK. RADAR ESTIMATES AND GROUND TRUTH
INDICATED A STRIP OF OVER INCH HAD FALLEN IN THE NORTHWEST PORTION
OF THE GREATER CAPITAL DISTRICT AS WELL AS A SMALL AREAS IN CENTRAL
ULSTER COUNTY.
THE REMAINDER OF THE REGION HAD CLOSER TO HALF AN INCH...EXCEPT
LESSER AMOUNTS IN OUR FAR NW AND SE CORNERS WHERE A TENTH OF AN INCH
OR EVEN LESS HAS FALLEN. RAIN WAS JUST BEGINNING TO FALL TOWARD
POUGHKEEPSIE AT THIS HOUR.
HAD TO LOWER OVERNIGHT LOWS A CATEGORY MOST PLACES...AS TEMPERATURES
HAVE REALLY DROPPED WELL DOWN INTO THE 40S...WITH SOME UPPER 30S IN
OUR NORTHWESTERN ZONES. FINALLY...THE FRONT HAS CROSSED THROUGH
POUGHKEEPSIE AND TEMPERATURES HAVE DROPPED INTO THE 50S THERE. STILL
HAVE SOME 60S CONFINED IN LITCHFIELD COUNTY...BUT THEY WILL DROP
INTO 50S SOON.
H850 TEMPERATURES LOOK TO BE ABOVE 0C EVERYWHERE IN OUR REGION BASED
ON THE LATEST RUC ANALYSIS AND EVEN H925 MB TEMPS ARE ABOVE 0C.
RADAR RETURNS HAVE WEAKENED GENERALLY OVER THE PAST HOUR OR SO.
STILL PLENTY OF RAIN OUT THERE...BUT MOSTLY OF THE LIGHT TO MODERATE
VARIETY (AS BRIGHT BANDING HAS APPEARED TO THE WESTERN AREAS).
WILL START WITH RAIN MOST PLACES...BUT THEN OVERNIGHT TAPER TO
SCATTERED SHOWERS AS SOME DRIER AIR TEMPORARILY WORKS IN FROM THE
NORTHWEST. HOWEVER...EXPECT CLOUDS TO PERSIST.
LOOK FOR OVERNIGHT LOWS IN THE 40S MOST PLACES...BUT MID TO UPPER
30S WELL NORTH AND WEST OF ALBANY.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
A STRONG SPRING STORM TO IMPACT THE REGION...
ONLY CHANGE WAS TO SLOW DOWN THE ADVANCE OF RAINFALL A SMIDGEN BASED
ON HPC/AND THE LATEST NAM MODEL. THE NEW NAM DEFINITELY HAS CUT BACK
ON THE QPF A LITTLE BUT THE MIDNIGHT FORECASTERS WILL NEED TO LOOK
AT ALL DATA BEFORE MAKING ANY REAL CHANGES.
H2O VAPOR LOOP REVEALS THE WEATHER ELEMENTS...A POTENT UPPER LOW
THAT WAS TRACKING ACROSS THE GULF OF MEXICO. A 130+KT UPPER WAS
QUICKLY DIVING SOUTHEAST ACROSS THE PLAINS TOWARD THE MID
MISSISSIPPI RIVER VALLEY. AN ACTIVE COASTAL FRONT ALONG THE
ATLANTIC COASTLINE WAS ALSO IN PLACE TODAY. THESE SYSTEMS ARE
EXPECTED TO PHASE OVER THE SOUTHEAST CONUS WITH A DEEPENING
SURFACE LOW TRACKING NORTHEAST ALONG THE SEABOARD /A NOR`EASTER/.
BEFORE THIS SYSTEM IMPACTS THE REGION...THERE WILL BE A BRIEF LULL
IN THE PRECIP SUNDAY MORNING AS MAIN COLD FRONT IS EAST OF THE
AREA. WE WILL QUICKLY INCREASE THOSE POPS THROUGH THE DAY WITH
RAIN EVOLVING FROM SOUTH TO NORTH THROUGH THE DAY. PRESSURE
GRADIENT WILL BE ON THE INCREASE TOO AS SURFACE LOW DEEPENS FROM
NEAR 1000MB THIS EVENING ACROSS NORTHERN FLORIDA TO ~985MB BY 12Z
MONDAY. QPF FROM THE MODELS APPEAR TO BE SETTLING ALONG THE LINES
OF 1-3 INCHES WITH UPSLOPE ENHANCEMENTS PERHAPS ADDING ANOTHER
INCH TO THOSE TOTALS /SEE HYDRO SECTION BELOW FOR FURTHER DETAILS/.
OTHERWISE...STRONG QG FORCING AND FGEN WILL MAKE FOR BANDS OF
MODERATE TO PERHAPS HEAVY RAINFALL ACROSS THE ENTIRE REGION LATE
SUNDAY INTO EARLY MONDAY MORNING. DRY SLOT APPROACHES DURING THE
DAYLIGHT HOURS MONDAY WHICH WILL SERVE TO DECREASE THE PRECIP
COVERAGE AND INTENSITY ACROSS THE REGION. THE COMBINATION OF A
STRONG SOUTHEAST WIND...DOWNSLOPING COMPONENT COULD BRING A
COMBINATION OF A FEW BINOVCS AND WARMER TEMPERATURES FOR THE
HUDSON RIVER VALLEY.
REGARDING WINDS...AT THIS TIME NO HEADLINES DESPITE THE
STRENGTHENING SOUTH-SOUTHEAST WINDS. CLIMATOLOGY FAVORS PORTIONS
OF THE BERKS...SOUTHERN GREENS AND EASTERN CATSKILLS...BUT IT
SEEMS THE BEST JET CORE MAY REMAIN JUST TO OUR EAST AND WITHIN A
WARM ADVECTION REGIME...DIFFICULT TO MIX DOWN TO THE SURFACE. WE
WILL CONTINUE TO MONITOR TRENDS VERY CLOSELY.
AS THE SURFACE LOW TRACK NOW FURTHER INLAND ACROSS NY AND ACROSS
THE CATSKILLS...BOUNDARY LAYER TEMPERATURES APPEAR TO REMAIN AT OR
ABOVE FREEZING TO REDUCE THE THREAT OF MINOR ACCUMULATING SNOW FOR
THE HIGHER TERRAIN. THEREFORE...WE HAVE GREATLY REDUCED SNOWFALL
AMOUNTS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
CONDITIONS WILL ONLY GRADUALLY IMPROVE IN THE LONG TERM PERIOD AS
THE LOW PRESSURE SYSTEM RESPONSIBLE FOR ALL OF THE PRECIPITATION
WILL ONLY SLOWLY MOVE AWAY FROM OUR REGION. IT WILL LIKELY TAKE
UNTIL THURSDAY NIGHT AND FRIDAY BEFORE SIGNIFICANT IMPROVEMENT
OCCURS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...CUTOFF UPPER LOW OVER NORTHERN
PA MONDAY NIGHT IS EXPECTED TO DRIFT SLOWLY NORTH ACROSS WESTERN NEW
YORK AND INTO ONTARIO ON TUESDAY. MEANWHILE SURFACE LOW LIFTS FROM
WEST CENTRAL NEW YORK MONDAY EVENING TO SOUTHEAST OF JAMES BAY
TUESDAY EVENING AND THEN EAST OF HUDSON BAY LATE TUESDAY NIGHT.
EXPECT SCATTERED TO NUMEROUS RAIN AND SNOW SHOWERS WITH THE HIGHEST
POPS ACROSS THE NORTHWEST THIRD OF THE FA AND GREATEST CHANCE OF
SNOW SHOWERS AFTER MIDNIGHT MONDAY NIGHT AND TUESDAY NIGHT. LOWS ARE
EXPECTED TO BE IN THE 30S TO AROUND 40 WITH HIGHS ON TUESDAY IN THE
40S TO MID 50S.
WEDNESDAY THROUGH THURSDAY...STILL EXPECT CHANCE POPS AS A SECONDARY
TROUGH AXIS MOVES ACROSS THE AREA WHILE A FAST MOVING LOW PRESSURE
SYSTEM MOVES FROM THE CENTRAL MISSISSIPPI VALLEY WEDNESDAY MORNING
TO THE MID ATLANTIC COAST THURSDAY MORNING. ONCE AGAIN THERE WILL BE
SOME SNOW SHOWERS ACROSS THE NORTHERN MOUNTAINS ESPECIALLY AFTER
MIDNIGHT WEDNESDAY NIGHT. HIGHS WEDNESDAY AND THURSDAY ARE EXPECTED
TO BE IN THE MID 40S TO AROUND 60 WITH LOWS WEDNESDAY NIGHT IN THE
30S TO LOWER 40S...ALTHOUGH SOME UPPER 20S ARE POSSIBLE ACROSS THE
WESTERN ADIRONDACKS.
THURSDAY NIGHT AND FRIDAY...EXPECT GRADUAL IMPROVEMENT AS A RIDGE OF
HIGH PRESSURE SLOWLY BUILDS EAST INTO THE GREAT LAKES REGION. THERE
MAY STILL BE A FEW SCATTERED RAIN OR SNOW SHOWERS CONFINED TO THE
WESTERN ADIRONDACKS MAINLY THURSDAY NIGHT. EXPECT LOWS THURSDAY
NIGHT IN THE UPPER 20S TO AROUND 40 WITH HIGHS ON FRIDAY IN THE MID
40S TO AROUND 60.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
LOOKS AS IF MAINLY SUB-VFR CONDITIONS WILL BE THE RULE AT THE TAF
SITES THROUGH SUNDAY.
THE COLD FRONT HAS FINALLY MADE IT TO POUGHKEEPSIE SO NOW THEIR
CEILING SHOULD DROP INTO THE MVFR OR LOW MVFR RANGE. (DECIDED TO
REMOVE ANY MENTION OF IFR). NO CLOUD TO GROUND LIGHTNING LATELY SO
REMOVED THE MENTION OF THUNDER.
BEHIND THE FRONT...IFR CIGS LOOK TO HOLD AT KALB FOR AWHILE
TONIGHT...BEFORE POSSIBLE LIFTING BACK TO LOW MVFR (BELOW 2000
FEET). THAT THINKING IS NOT CERTAIN...ONLY A LITTLE BETTER THAN 50
PERCENT SO CHECK BACK IF YOU MUST INCLUDE IFR RESTRICTION LATER
TONIGHT AT KALB.
AT KGFL...IT APPEARS THAT A DOWNSLOPING NE WIND MIGHT POSSIBLY KEEP
CIGS AND EVEN VSBYS JUST ABOVE IFR. SO FAR THAT IDEA HAS WORKED.
HOWEVER...THIS IS NEARLY A 50/50 BET (WE LEANED A LITTLE HIGHER THAN
THAT) BUT KEPT THEM AT THE LOW MVFR RANGE THROUGH 08Z.
AS WE HEAD TOWARD THE MORNING PEAK ON SUNDAY...CONDITIONS LOOK TO
MARGINALLY IMPROVE AS CIGS ARE FORECAST TO LIFT BACK TO THE HIGH
LEVEL OF MVFR AND FOR AWHILE...ANY RAIN SHOULD END. ENOUGH OF A
NORTH WIND SHOULD PREVENT FOG FROM FORMING AND ANY DRIZZLE WOULD
LIKELY NOT IMPACT VSBYS OR EVEN CIGS TOO MUCH.
LATER ON SUNDAY...THE MAIN STORM WILL BEGIN TO PUSH ITS RAINSHIELD
TOWARD THE TAF SITES BY SUNDAY AFTERNOON. WE DROPPED THE TAFS BACK
FURTHER TOWARD MVFR FOR NOW...STILL JUST ABOVE THE 2000 FOOT MINIMUM
REQUIRED TO CARRY ADDITIONAL FUEL.
.OUTLOOK...
SUN NITE-MON...SUB-VFR CIG RAIN. CHC IFR IN HVY RAIN.
MON NT-WED NT...VFR CIG...CHC SUB-VFR -SHRAS.
THU...VFR. NO SIG WX.
&&
.FIRE WEATHER...
WIDESPREAD MEASURABLE RAINFALL EXPECTED ACROSS THE ENTIRE REGION
SINCE APRIL 1ST. AN AREA OF LOW PRESSURE WILL APPROACH FROM THE SOUTH
SUNDAY AND MOVE ACROSS THE REGION MONDAY BRINGING A SOAKING RAINFALL
WHICH WILL GREATLY DIMINISHING FIRE WEATHER CONCERNS.
&&
.HYDROLOGY...
PER THE DROUGHT MONITOR...OUR CWA RANGED FROM D0-D3. THE UPCOMING
RAINFALL EVENT OF 1 TO 3 INCHES...WITH UP TO 4 INCHES ACROSS
FAVORABLE UPSLOPE AREAS OF THE CATSKILLS...SOUTHERN GREENS AND
PORTIONS OF THE BERKS...DROUGHT CONDITIONS ARE EXPECTED TO BE
ALLEVIATED.
A CLOSER EXAMINATION THE MMEFS AND LATEST NERFC
GUIDANCE...SEVERAL RIVER POINTS ARE FORECAST TO RISE TOWARD AND
ABOVE FLOOD STAGE. COMBINE THIS WITH PORTIONS OF THE REGION
GROUNDS ABILITY TO ABSORB WATER IN QUESTION...WE WILL HOIST A
FLOOD WATCH FOR PORTIONS OF THE REGION /MAINLY SOUTH AND EAST OF
THE CAPITAL REGION/.
OTHERWISE ANTECEDENT CONDITIONS ARE VERY DRY...PRECIPITATION
DEFICITS ARE RUNNING 5 TO 10 INCHES BELOW NORMAL ACROSS EASTERN
NEW YORK AND WESTERN NEW ENGLAND. STREAMFLOW CONDITIONS ARE AT
WELL BELOW NORMAL AND RESERVOIR LEVELS ACROSS THE AREA REMAIN NEAR
TO SLIGHTLY BELOW NORMAL. THE FORECAST RAINFALL AMOUNTS ARE
EXPECTED TO PRODUCE SIGNIFICANT WITHIN BANK RISES WITH SOME MINOR
FLOODING A POSSIBILITY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
PRECIPITATION (DEPARTURE FROM NORMAL)
ALBANY NY:
MONTH TO DATE THROUGH THE 20TH: 0.14 INCHES (-2.00 INCHES)
SINCE MAR 1: 1.68 INCHES (-3.67 INCHES)
SINCE JAN 1: 4.94 INCHES (-5.20 INCHES)
GLENS FALLS NY:
MONTH TO DATE THROUGH THE 20TH: 0.32 INCHES (-1.63 INCHES)
SINCE MAR 1: 1.55 INCHES (-3.34 INCHES)
SINCE JAN 1: 4.49 INCHES (-5.34 INCHES)
POUGHKEEPSIE NY:
MONTH TO DATE THROUGH THE 20TH: 0.26 INCHES (-2.27 INCHES)
SINCE MAR 1: 1.45 INCHES (-4.65 INCHES)
SINCE JAN 1: 5.06 INCHES (-6.78 INCHES)
BENNINGTON VT:
MONTH TO DATE THROUGH THE 20TH: 0.47 INCHES (-1.79 INCHES)
SINCE MAR 1: 2.05 INCHES (-3.36 INCHES)
SINCE JAN 1: 4.55 INCHES (-5.85 INCHES)
PITTSFIELD MA:
MONTH TO DATE THROUGH THE 20TH: 0.38 INCHES (-2.47 INCHES)
SINCE MAR 1: 1.52 INCHES (-4.70 INCHES)
SINCE JAN 1: 5.73 INCHES (-6.09 INCHES)
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR
CTZ001-013.
NY...FLOOD WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR
NYZ043-047-053-054-058>061-063>066-084.
MA...FLOOD WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR
MAZ001-025.
VT...FLOOD WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR
VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...HWJIV/BGM
SHORT TERM...BGM/HWJIV
LONG TERM...11
AVIATION...HWJIV
FIRE WEATHER...BGM
HYDROLOGY...BGM/11
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
142 PM EDT FRI APR 20 2012
.SYNOPSIS...
A WEAK AREA OF HIGH PRESSURE ACROSS THE AREA EARLY TODAY WILL LOSE
ITS INFLUENCE OVER THE WEATHER TONIGHT. A LOW PRESSURE SYSTEM WILL
MOVE ACROSS THE GREAT LAKES TONIGHT AND THEN INTO NEW ENGLAND
SATURDAY. AN ATTACHED COLD FRONT WILL CROSS THE AREA SATURDAY. LOW
PRESSURE WILL DEEPEN NEAR FLORIDA SUNDAY AND THEN STRENGTHEN WHILE
MOVING NORTHWARD ALONG THE FRONT THROUGH MONDAY. THE STRONG LOW WILL
THEN TRACK NORTH OF THE AREA MONDAY THROUGH TUESDAY. HIGH PRESSURE
WILL EVENTUALLY BUILD BACK ACROSS THE AREA BY THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE STRATUS IS NOW GONE...AND THE FORECAST PROBLEM IS NOW BASED
ALMOST ENTIRELY ON THE CUMULUS/STRATOCUMULUS DECK COVERING MUCH
OF THE FORECAST AREA LATE THIS MORNING. THE LATEST RUC SUGGESTS
THAT THE AREA OF CLOUDINESS ACROSS SOUTHEAST PORTIONS CONSOLIDATES
EARLY THIS AFTERNOON...THEN MOVES NORTHEAST WITH THE BOUNDARY
LAYER FLOW.
THERE IS A BREAK DEVELOPING ACROSS THE SOUTHERN DELMARVA...BUT
THIS MAY NOT HAVE MUCH OF AN IMPACT ON THE SKY COVER ACROSS
EASTERN SECTIONS THIS AFTERNOON. BASED ON THE CLOUD COVER IN
PLACE...AND THE POTENTIAL FOR BREAKS THIS AFTERNOON...HIGH
TEMPERATURES WERE NUDGED DOWN ACROSS EASTERN SECTIONS. LESS
HEATING MAY MEAN LESS IN THE WAY OF SEA AND BAY BREEZES...AND
WINDS WERE ADJUSTED DOWN A BIT.
FURTHER WEST...THE CUMULUS IS MORE OR LESS BASED ON HEATING OF THE
MOISTENED BOUNDARY LAYER. THIS SHOULD MEAN MORE IN THE WAY OF
BREAK FOR SOUTHEAST PENNSYLVANIA THIS AFTERNOON...AND NOT AS MUCH
OF AN IMPACT FOR THE LEHIGH VALLEY AND THE HIGHER TERRAIN. IN
THESE AREAS...HIGH TEMPERATURES WERE NOT MODIFIED MUCH BASED ON
THE EXPECTED SUNSHINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
HERE WE WILL DEVIATE A BIT FROM THE WRF-NMMB AND TAKE AN AVERAGE OF
IT AND THE GFS. THE MOIST SERLY FLOW IS FORECAST TO PERSIST. AS SUCH
THE UPSLOPE, CONVERGENT FLOW SHOULD HELP DEVELOP CLOUDS. WE MIGHT BE
TOO FAST, BUT BELIEVE WE WILL GET THERE BEFORE THE NIGHT IS DONE.
BASED ON THE MODELS FORECASTING SOME LIGHT MEASURABLE, TOOK THIS AS
SOME UPSLOPING DRIZZLE OR LIGHT RAIN OCCURRING. WE KEPT A CHANCE IN
THE NORTHERN HALF OF OUR CWA. DO NOT THINK STAT GUIDANCE COULD GET
ANY CLOSER AND OTHER THAN PHL WHERE WE WENT ABOVE THEM BECAUSE OF
URBAN EFFECTS, PRETTY MUCH ACCEPTED IT.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
CLOUDS WILL BE INCREASING ACROSS THE AREA SATURDAY AS LOW PRESSURE
WILL BE TRACKING DOWN THE SAINT LAWRENCE VALLEY AND ITS ATTACHED
COLD FRONT WILL BE APPROACHING FROM THE WEST. SHOWERS AND SCATTERED
TSTMS WILL ACCOMPANY THE FRONT. THE NAM AND GFS ARE BOTH INDICATING
SOME SFC BASED CAPE IN THE 500 TO 1000 J/KG RANGE FOR SATURDAY...SO
WE WILL KEEP THE THUNDER IN THERE FOR NOW. SPC HAS A `SEE TEXT`
MENTION IN THE SWODY2 DISCUSSION FOR THE NORTHERN MIDDLE ATLANTIC
REGION. THE FRONT SLOWS AS IT MOVES EAST OF THE AREA SATURDAY NIGHT.
THIS WILL PROLONG THE PRECIP EVENT WITH LIGHTER AMOUNTS SAT NIGHT
AND HIGH CHC POPS.
THE MORE SIGNIFICANT EVENT IN THE EXTENDED WILL ARRIVE SUNDAY IN THE
FORM OF DEEP MOISTURE AND LIFT ASSOCIATED WITH THE STRENGTHENING LOW
MOVING NORTHWARD FROM FL. THE SHIELD OF RAIN WILL OVERSPREAD THE
AREA FROM THE SOUTH SUN MORNING AND PERSIST OVER THE AREA AT LEAST
UNTIL MON MORNING WITH THE POTENTIAL OF 1 TO 3 INCHES OF RAIN. THE
MODELS HAVE COME INTO BETTER AGREEMENT (COMPARED TO YESTERDAY) BUT
ARE STILL OFFERING DIFFERENT TRACK AFTER THEY ARRIVE AT OUR
LATITUDE. THE GFS TURNED THE DEEP SFC LOW MORE WESTWARD ACROSS PA
WHILE THE NAM AND 12Z EC TRACK THE SYSTEM NORTHWARD ACROSS THE
NEARSHORE WATERS. THE 12Z EC HOOKS THE LOW BACK WESTWARD ONCE IT
REACHES NYC HOWEVER. THE OVERNIGHT EXTENDED GRIDS HAVE BEEN MODIFIED
TO RESEMBLE THE NAM/12Z EC SOLUTIONS FOR THE MOST PART...NOT MUCH
DIFFERENT THE THE PREVIOUS FCST. HIGHER POPS AND NEW HPC QPF
GRAPHICS HAVE BEEN CREATED.
THE DEEP LOW WILL TRACK AWAY FROM THE AREA MON-WED. HIGH PRESSURE
WILL GRADUALLY BUILD BACK ACROSS THE AREA. WINDY AND COOL WEATHER
WILL BE ACROSS THE AREA MON-WED. POPS DECREASE BACK TO CHC LEVELS BY
MON AFTERNOON...THEN SLGT CHC FOR MON NIGHT AND TUE. TEMPERATURES
MAY BE LOW ENOUGH TO SUPPORT SOME SNOW ACROSS THE FAR NORTH...BUT IT
WILL BE VERY MARGINAL AND IT MAY BE A LOW ENOUGH PROBABILITY EVENT
TO NOT INCLUDE IN THE FCST ATTM.
WE ARE KEEPING A DRY FCST AT THE END OF THE EXTENDED PERIOD FOR NOW.
THE NEW EC HAS ARRIVED HOWEVER WITH ANOTHER SYNOPTIC SYSTEM ACROSS
THE AREA...WE`LL HAVE TO WATCH THIS FOR A FEW MORE MODEL RUNS TO SEE
IF HIGHER POPS WILL BE NEEDED.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE STRATUS HAS LIFTED INTO A CUMULUS/STRATOCUMULUS LAYER ACROSS
MUCH OF THE AREA EARLY THIS AFTERNOON. FROM KPHL NORTH AND
WEST...VFR CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE
AFTERNOON...WITH SOUTH WINDS NEAR 10 KNOTS. FOR KACY AND
KMIV...WHICH ARE CLOSER TO THE SOURCE OF THE MOISTURE FOR THE
CLOUDS...THE INVERSION IS LOWER...AND MVFR CONDITIONS ARE EXPECTED
INTO THE EARLY EVENING HOURS.
AFTER 0000 UTC...THE STRATUS AND FOG WILL RETURN FROM WEST TO
EAST...AS THE ONSHORE FLOW BRINGS MOISTURE BACK WEST. MVFR/IFR
CONDITIONS ARE EXPECTED AT KABE/KRDG...WHICH WILL BE FURTHEST FROM
THE MOISTURE SOURCE. MVFR CONDITIONS COULD RETURN TO THE KPHL METRO
AIRPORTS AS EARLY AFTER 0100 UTC SATURDAY...AS THE CLOUDINESS OVER
EASTERN NEW JERSEY GETS BACK WEST. IFR CONDITIONS ARE EXPECTED AFTER
0600 UTC FROM KPHL SOUTH AND EAST...WITH SOME LIFR CONDITIONS
POSSIBLE.
THE IFR/MVFR CONDITIONS SHOULD IMPROVE FROM WEST TO EAST BETWEEN 1300
UTC AND 1600 UTC SATURDAY. THE AIRMASS BECOMES MARGINALLY UNSTABLE
FROM WEST TO EAST...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS FROM THE I-95 CORRIDOR WEST. LOCAL MVFR CONDITIONS ARE
POSSIBLE WITH THE SHOWERS AND STORMS.
OUTLOOK...
SAT NIGHT...MVFR CONDITIONS DROPPING TO IFR. EVENING CONVECTION
SHOULD DIE OFF...BUT STEADIER RAIN IS POSSIBLE TOWARD 1200 UTC
SUNDAY.
SUN-MON...MOSTLY IFR CONDITIONS WITH LOW CIGS/VSBYS RAIN AND
GUSTY WINDS.
MON NGT-TUE...IMPROVEMENT TO VFR BY TUE ACROSS MOST AREAS BUT SCT SHOWERS
MAY CREATE LOWER CONDITIONS AT TIMES.
&&
.MARINE...
SUB SMALL CRAFT ADVISORY CONDITIONS ARE FORECAST TO CONTINUE TODAY
AND TONIGHT. WAVE WATCH GUIDANCE CONTINUES TO BE TOO HIGH WITH THE
EASTERLY SWELL AND WE ARE TAKING APPROXIMATELY A FOOT OFF THE
GUIDANCE. WINDS OVERALL TODAY SHOULD BE RELATIVELY LIGHT FROM THE
EAST AND SOUTHEAST. THERE WILL LIKELY BE AN INCREASE IN SPEED IN
DELAWARE BAY AGAIN LATER IN THE AFTERNOON AND EARLY IN THE EVENING
AS THE FLOW WILL BE UP THE BAY AGAIN.
WINDS SHOULD BACK MORE TO THE SOUTH TONIGHT, BUT OVERALL SPEEDS
SHOULD REMAIN LESS THAN 15KTS. SWELLS ARE NOT EXPECTED TO INCREASE
IN TIME TO CAUSE ANY SMALL CRAFT CONDITIONS.
OUTLOOK...
SMALL CRAFT CONDITIONS DEVELOPING SAT WITH GALES POSSIBLE SUN-MON.
A RETURN BACK TO SUB-SCA CONDITIONS BY TUE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...HAYES
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...HAYES
MARINE...GIGI
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1132 AM EDT FRI APR 20 2012
.SYNOPSIS...
A WEAK AREA OF HIGH PRESSURE ACROSS THE AREA EARLY TODAY WILL LOSE
ITS INFLUENCE OVER THE WEATHER TONIGHT. A LOW PRESSURE SYSTEM WILL
MOVE ACROSS THE GREAT LAKES TONIGHT AND THEN INTO NEW ENGLAND
SATURDAY. AN ATTACHED COLD FRONT WILL CROSS THE AREA SATURDAY. LOW
PRESSURE WILL DEEPEN NEAR FLORIDA SUNDAY AND THEN STRENGTHEN WHILE
MOVING NORTHWARD ALONG THE FRONT THROUGH MONDAY. THE STRONG LOW WILL
THEN TRACK NORTH OF THE AREA MONDAY THROUGH TUESDAY. HIGH PRESSURE
WILL EVENTUALLY BUILD BACK ACROSS THE AREA BY THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE STRATUS IS NOW GONE...AND THE FORECAST PROBLEM IS NOW BASED
ALMOST ENTIRELY ON THE CUMULUS/STRATOCUMULUS DECK COVERING MUCH
OF THE FORECAST AREA LATE THIS MORNING. THE LATEST RUC SUGGESTS
THAT THE AREA OF CLOUDINESS ACROSS SOUTHEAST PORTIONS CONSOLIDATES
EARLY THIS AFTERNOON...THEN MOVES NORTHEAST WITH THE BOUNDARY
LAYER FLOW.
THERE IS A BREAK DEVELOPING ACROSS THE SOUTHERN DELMARVA...BUT
THIS MAY NOT HAVE MUCH OF AN IMPACT ON THE SKY COVER ACROSS
EASTERN SECTIONS THIS AFTERNOON. BASED ON THE CLOUD COVER IN
PLACE...AND THE POTENTIAL FOR BREAKS THIS AFTERNOON...HIGH
TEMPERATURES WERE NUDGED DOWN ACROSS EASTERN SECTIONS. LESS
HEATING MAY MEAN LESS IN THE WAY OF SEA AND BAY BREEZES...AND
WINDS WERE ADJUSTED DOWN A BIT.
FURTHER WEST...THE CUMULUS IS MORE OR LESS BASED ON HEATING OF THE
MOISTENED BOUNDARY LAYER. THIS SHOULD MEAN MORE IN THE WAY OF
BREAK FOR SOUTHEAST PENNSYLVANIA THIS AFTERNOON...AND NOT AS MUCH
OF AN IMPACT FOR THE LEHIGH VALLEY AND THE HIGHER TERRAIN. IN
THESE AREAS...HIGH TEMPERATURES WERE NOT MODIFIED MUCH BASED ON
THE EXPECTED SUNSHINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
HERE WE WILL DEVIATE A BIT FROM THE WRF-NMMB AND TAKE AN AVERAGE OF
IT AND THE GFS. THE MOIST SERLY FLOW IS FORECAST TO PERSIST. AS SUCH
THE UPSLOPE, CONVERGENT FLOW SHOULD HELP DEVELOP CLOUDS. WE MIGHT BE
TOO FAST, BUT BELIEVE WE WILL GET THERE BEFORE THE NIGHT IS DONE.
BASED ON THE MODELS FORECASTING SOME LIGHT MEASURABLE, TOOK THIS AS
SOME UPSLOPING DRIZZLE OR LIGHT RAIN OCCURRING. WE KEPT A CHANCE IN
THE NORTHERN HALF OF OUR CWA. DO NOT THINK STAT GUIDANCE COULD GET
ANY CLOSER AND OTHER THAN PHL WHERE WE WENT ABOVE THEM BECAUSE OF
URBAN EFFECTS, PRETTY MUCH ACCEPTED IT.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
CLOUDS WILL BE INCREASING ACROSS THE AREA SATURDAY AS LOW PRESSURE
WILL BE TRACKING DOWN THE SAINT LAWRENCE VALLEY AND ITS ATTACHED
COLD FRONT WILL BE APPROACHING FROM THE WEST. SHOWERS AND SCATTERED
TSTMS WILL ACCOMPANY THE FRONT. THE NAM AND GFS ARE BOTH INDICATING
SOME SFC BASED CAPE IN THE 500 TO 1000 J/KG RANGE FOR SATURDAY...SO
WE WILL KEEP THE THUNDER IN THERE FOR NOW. SPC HAS A `SEE TEXT`
MENTION IN THE SWODY2 DISCUSSION FOR THE NORTHERN MIDDLE ATLANTIC
REGION. THE FRONT SLOWS AS IT MOVES EAST OF THE AREA SATURDAY NIGHT.
THIS WILL PROLONG THE PRECIP EVENT WITH LIGHTER AMOUNTS SAT NIGHT
AND HIGH CHC POPS.
THE MORE SIGNIFICANT EVENT IN THE EXTENDED WILL ARRIVE SUNDAY IN THE
FORM OF DEEP MOISTURE AND LIFT ASSOCIATED WITH THE STRENGTHENING LOW
MOVING NORTHWARD FROM FL. THE SHIELD OF RAIN WILL OVERSPREAD THE
AREA FROM THE SOUTH SUN MORNING AND PERSIST OVER THE AREA AT LEAST
UNTIL MON MORNING WITH THE POTENTIAL OF 1 TO 3 INCHES OF RAIN. THE
MODELS HAVE COME INTO BETTER AGREEMENT (COMPARED TO YESTERDAY) BUT
ARE STILL OFFERING DIFFERENT TRACK AFTER THEY ARRIVE AT OUR
LATITUDE. THE GFS TURNED THE DEEP SFC LOW MORE WESTWARD ACROSS PA
WHILE THE NAM AND 12Z EC TRACK THE SYSTEM NORTHWARD ACROSS THE
NEARSHORE WATERS. THE 12Z EC HOOKS THE LOW BACK WESTWARD ONCE IT
REACHES NYC HOWEVER. THE OVERNIGHT EXTENDED GRIDS HAVE BEEN MODIFIED
TO RESEMBLE THE NAM/12Z EC SOLUTIONS FOR THE MOST PART...NOT MUCH
DIFFERENT THE THE PREVIOUS FCST. HIGHER POPS AND NEW HPC QPF
GRAPHICS HAVE BEEN CREATED.
THE DEEP LOW WILL TRACK AWAY FROM THE AREA MON-WED. HIGH PRESSURE
WILL GRADUALLY BUILD BACK ACROSS THE AREA. WINDY AND COOL WEATHER
WILL BE ACROSS THE AREA MON-WED. POPS DECREASE BACK TO CHC LEVELS BY
MON AFTERNOON...THEN SLGT CHC FOR MON NIGHT AND TUE. TEMPERATURES
MAY BE LOW ENOUGH TO SUPPORT SOME SNOW ACROSS THE FAR NORTH...BUT IT
WILL BE VERY MARGINAL AND IT MAY BE A LOW ENOUGH PROBABILITY EVENT
TO NOT INCLUDE IN THE FCST ATTM.
WE ARE KEEPING A DRY FCST AT THE END OF THE EXTENDED PERIOD FOR NOW.
THE NEW EC HAS ARRIVED HOWEVER WITH ANOTHER SYNOPTIC SYSTEM ACROSS
THE AREA...WE`LL HAVE TO WATCH THIS FOR A FEW MORE MODEL RUNS TO SEE
IF HIGHER POPS WILL BE NEEDED.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE STRATUS/FOG CONTINUE TO ERODE...WITH THE IFR CONDITIONS EXPECTED
TO BE GONE BY 1430 UTC. THE NEXT PROBLEM IS THE CLOUDINESS EXTENDING
NORTHWEST FROM THE ATLANTIC INTO DELAWARE...NEW JERSEY AND SOUTHEAST
PENNSYLVANIA. FOR THE MOST PART...THE CEILINGS ARE VFR...BUT THERE
IS A BATCH OF MVFR CEILINGS EXTENDING FROM SOUTHERN DELAWARE INTO
SOUTHERN NEW JERSEY (KMIV) AND SOUTHEAST PENNSYLVANIA (NEAR KPHL).
WITH HEATING...THE CLOUD BASE SHOULD RISE...AND VFR CEILINGS ARE
EXPECTED THIS AFTERNOON. HOWEVER...MVFR CEILINGS COULD AFFECT
KMIV...KILG...KPHL AND POSSIBLY KPNE THROUGH ABOUT 1600 UTC. AFTER
THAT TIME...ALL CEILINGS ARE EXPECTED TO BE VFR.
WINDS ARE TRYING TO COME AROUND TO SEA AND BAY BREEZE CONFIGURATION...
AND FOR THE MOST PART WINDS ARE EXPECTED TO REMAIN BELOW 10
KNOTS.
FOR TONIGHT WE ARE FOLLOWING THE SUGGESTION OF ONE MODEL THAT A
MVFR CIG SHOULD DEVELOP AND OR MOVE IN FROM THE OCEAN AND BAY
DURING THE EVENING HOURS. CONFIDENCE ON THE EVOLUTION IS GREATER
THAN AVERAGE ALTHOUGH THE SPECIFIC TIMING OF OCCURRENCE WE ARE
LESS CONFIDENT. SOME VSBY RESTRICTIONS DUE TO FOG ARE ALSO
POSSIBLE. WINDS WILL REMAIN FROM THE SOUTHEAST, BUT BECOME
LIGHTER.
OUTLOOK...
SAT AND SAT NIGHT...DETERIORATING CONDITIONS EXPECTED SATURDAY WITH
PERIODS OF MVFR/IFR IN SHOWERS AND SCT TSTMS. CONDITIONS MOSTLY
SUB-VFR SAT NIGHT WITH LOW CIGS/VSBYS.
SUN-MON...MOSTLY IFR CONDITIONS WITH LOW CIGS/VSBYS RAIN AND
GUSTY WINDS.
MON NGT-TUE...IMPROVEMENT TO VFR BY TUE ACROSS MOST AREAS BUT SCT SHOWERS
MAY CREATE LOWER CONDITIONS AT TIMES.
&&
.MARINE...
SUB SMALL CRAFT ADVISORY CONDITIONS ARE FORECAST TO CONTINUE TODAY
AND TONIGHT. WAVE WATCH GUIDANCE CONTINUES TO BE TOO HIGH WITH THE
EASTERLY SWELL AND WE ARE TAKING APPROXIMATELY A FOOT OFF THE
GUIDANCE. WINDS OVERALL TODAY SHOULD BE RELATIVELY LIGHT FROM THE
EAST AND SOUTHEAST. THERE WILL LIKELY BE AN INCREASE IN SPEED IN
DELAWARE BAY AGAIN LATER IN THE AFTERNOON AND EARLY IN THE EVENING
AS THE FLOW WILL BE UP THE BAY AGAIN.
WINDS SHOULD BACK MORE TO THE SOUTH TONIGHT, BUT OVERALL SPEEDS
SHOULD REMAIN LESS THAN 15KTS. SWELLS ARE NOT EXPECTED TO INCREASE
IN TIME TO CAUSE ANY SMALL CRAFT CONDITIONS.
OUTLOOK...
SMALL CRAFT CONDITIONS DEVELOPING SAT WITH GALES POSSIBLE SUN-MON.
A RETURN BACK TO SUB-SCA CONDITIONS BY TUE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI/HAYES
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...GIGI/HAYES
MARINE...GIGI
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
835 AM EDT FRI APR 20 2012
.SYNOPSIS...
A WEAK AREA OF HIGH PRESSURE ACROSS THE AREA EARLY TODAY WILL LOSE
ITS INFLUENCE OVER THE WEATHER TONIGHT. A LOW PRESSURE SYSTEM WILL
MOVE ACROSS THE GREAT LAKES TONIGHT AND THEN INTO NEW ENGLAND
SATURDAY. AN ATTACHED COLD FRONT WILL CROSS THE AREA SATURDAY. LOW
PRESSURE WILL DEEPEN NEAR FLORIDA SUNDAY AND THEN STRENGTHEN WHILE
MOVING NORTHWARD ALONG THE FRONT THROUGH MONDAY. THE STRONG LOW WILL
THEN TRACK NORTH OF THE AREA MONDAY THROUGH TUESDAY. HIGH PRESSURE
WILL EVENTUALLY BUILD BACK ACROSS THE AREA BY THE MIDDLE OF NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE STRATUS/PATCHY DENSE FOG IS SLOWLY LIFTING ACROSS THE I-95
CORRIDOR...AS THE SUN ANGLE IS GETTING HIGH ENOUGH TO ALLOW THE
MOISTURE TO MIX OUT FROM UNDER THE INVERSION. THIS AREA SHOULD BE
GONE BEFORE 1000 AM...BASED ON CURRENT TRENDS.
THE NEXT PROBLEM IS THE CLOUDINESS EXTENDING NORTHWEST FROM THE
OCEAN. THE MASS IS NOW COVERING MUCH OF DELAWARE AND MUCH OF
SOUTHEAST NEW JERSEY. EVEN THOUGH THE CLOUDINESS IS NOT AS LOW AS
THE STRATUS IN PLACE NOW...IT WILL AFFECT THE CLOUD COVER
FORECAST...AS WELL AS THE TEMPERATURE FORECAST...FOR THE REST OF
THE MORNING AT LEAST.
THE LATEST RUC SUGGESTS THAT THE AREA OF CLOUDINESS ACROSS
SOUTHEAST PORTIONS CONSOLIDATES LATER THIS MORNING...THEN MOVES
NORTHEAST WITH THE BOUNDARY LAYER FLOW. THIS WOULD ALLOW SOME
IMPROVEMENT FOR DELAWARE AND SOUTHEAST NEW JERSEY THIS AFTERNOON.
BASED ON TRENDS...WILL NUDGE THE CLOUD FORECAST IN THIS DIRECTION.
STAT GUIDANCE IS AMAZINGLY UNIFORM AND A BLEND WAS USED. WE UPPED
MAXES THEN SLIGHTLY INLAND BECAUSE OF RECENT TRENDS AND OUR DRY
WEATHER. TRIED AGAIN TO SHOW AN EARLIER IN THE DAY MAX TEMP ALONG
THE COAST. DO NOT KNOW IF WE WILL SEE A SEA BREEZE FRONT PER SE ON
OUR RADARS TODAY, BUT THE GENERAL WIND FLOW WILL BE SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
HERE WE WILL DEVIATE A BIT FROM THE WRF-NMMB AND TAKE AN AVERAGE OF
IT AND THE GFS. THE MOIST SERLY FLOW IS FORECAST TO PERSIST. AS SUCH
THE UPSLOPE, CONVERGENT FLOW SHOULD HELP DEVELOP CLOUDS. WE MIGHT BE
TOO FAST, BUT BELIEVE WE WILL GET THERE BEFORE THE NIGHT IS DONE.
BASED ON THE MODELS FORECASTING SOME LIGHT MEASURABLE, TOOK THIS AS
SOME UPSLOPING DRIZZLE OR LIGHT RAIN OCCURRING. WE KEPT A CHANCE IN
THE NORTHERN HALF OF OUR CWA. DO NOT THINK STAT GUIDANCE COULD GET
ANY CLOSER AND OTHER THAN PHL WHERE WE WENT ABOVE THEM BECAUSE OF
URBAN EFFECTS, PRETTY MUCH ACCEPTED IT.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
CLOUDS WILL BE INCREASING ACROSS THE AREA SATURDAY AS LOW PRESSURE
WILL BE TRACKING DOWN THE SAINT LAWRENCE VALLEY AND ITS ATTACHED
COLD FRONT WILL BE APPROACHING FROM THE WEST. SHOWERS AND SCATTERED
TSTMS WILL ACCOMPANY THE FRONT. THE NAM AND GFS ARE BOTH INDICATING
SOME SFC BASED CAPE IN THE 500 TO 1000 J/KG RANGE FOR SATURDAY...SO
WE WILL KEEP THE THUNDER IN THERE FOR NOW. SPC HAS A `SEE TEXT`
MENTION IN THE SWODY2 DISCUSSION FOR THE NORTHERN MIDDLE ATLANTIC
REGION. THE FRONT SLOWS AS IT MOVES EAST OF THE AREA SATURDAY NIGHT.
THIS WILL PROLONG THE PRECIP EVENT WITH LIGHTER AMOUNTS SAT NIGHT
AND HIGH CHC POPS.
THE MORE SIGNIFICANT EVENT IN THE EXTENDED WILL ARRIVE SUNDAY IN THE
FORM OF DEEP MOISTURE AND LIFT ASSOCIATED WITH THE STRENGTHENING LOW
MOVING NORTHWARD FROM FL. THE SHIELD OF RAIN WILL OVERSPREAD THE
AREA FROM THE SOUTH SUN MORNING AND PERSIST OVER THE AREA AT LEAST
UNTIL MON MORNING WITH THE POTENTIAL OF 1 TO 3 INCHES OF RAIN. THE
MODELS HAVE COME INTO BETTER AGREEMENT (COMPARED TO YESTERDAY) BUT
ARE STILL OFFERING DIFFERENT TRACK AFTER THEY ARRIVE AT OUR
LATITUDE. THE GFS TURNED THE DEEP SFC LOW MORE WESTWARD ACROSS PA
WHILE THE NAM AND 12Z EC TRACK THE SYSTEM NORTHWARD ACROSS THE
NEARSHORE WATERS. THE 12Z EC HOOKS THE LOW BACK WESTWARD ONCE IT
REACHES NYC HOWEVER. THE OVERNIGHT EXTENDED GRIDS HAVE BEEN MODIFIED
TO RESEMBLE THE NAM/12Z EC SOLUTIONS FOR THE MOST PART...NOT MUCH
DIFFERENT THE THE PREVIOUS FCST. HIGHER POPS AND NEW HPC QPF
GRAPHICS HAVE BEEN CREATED.
THE DEEP LOW WILL TRACK AWAY FROM THE AREA MON-WED. HIGH PRESSURE
WILL GRADUALLY BUILD BACK ACROSS THE AREA. WINDY AND COOL WEATHER
WILL BE ACROSS THE AREA MON-WED. POPS DECREASE BACK TO CHC LEVELS BY
MON AFTERNOON...THEN SLGT CHC FOR MON NIGHT AND TUE. TEMPERATURES
MAY BE LOW ENOUGH TO SUPPORT SOME SNOW ACROSS THE FAR NORTH...BUT IT
WILL BE VERY MARGINAL AND IT MAY BE A LOW ENOUGH PROBABILITY EVENT
TO NOT INCLUDE IN THE FCST ATTM.
WE ARE KEEPING A DRY FCST AT THE END OF THE EXTENDED PERIOD FOR NOW.
THE NEW EC HAS ARRIVED HOWEVER WITH ANOTHER SYNOPTIC SYSTEM ACROSS
THE AREA...WE`LL HAVE TO WATCH THIS FOR A FEW MORE MODEL RUNS TO SEE
IF HIGHER POPS WILL BE NEEDED.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
WITH THE 06Z TAFS NOT VERY CONFIDENT ABOUT THE VSBY RESTRICTIONS
THIS MORNING. THAT PART RANG TRUE. EXPECT GENERALLY VFR
CONDITIONS LATER THIS MORNING AND AFTERNOON WITH CIGS AND VSBYS
LOWERING TONIGHT INTO MVFR LEVELS IF NOT LOWER.
THROUGH THIS MORNING MADE SOME ADJUSTMENTS BASED ON TEMP AND DEW
POINT SPREADS AND WENT MORE OPTIM WITH THE FOG NORTHWEST OF KPHL
AREA AIRPORTS AND MORE PESIM AT KMIV AND NOW KACY BECAUSE THEY
RADIATED. CLOUDS SWIRLING OFFSHORE ARE NOT MAKING ANY MOVEMENT
TOWARD THE COAST, WILL CONTINUE TO MONITOR FOR A CHANGE. THERE ARE
SOME BORDERLINE IFR STRATUS CLOUDS FORMING OFF OF DELAWARE BAY AND
WILL AFFECT KPHL EARLY. WINDS WILL BE LIGHT.
THE EXCELLENT RADIATIONAL COOLING CONDITIONS HAVE MADE IT EASY FOR
FOG TO FORM AND WE HAVE AMENDED MOST OF THE AIRPORTS DOWNWARD.
UNFORTUNATELY KPHL PROXIMITY TO THE DELAWARE RIVER HAS BROUGHT SOME
OF THE DENSEST FOG ALONG THE DELAWARE TO THE AIRPORT. STILL NOT
MANY CLOUDS ABOVE THE FOG AND STRATUS AND WE ARE STILL EXPECTING A
FAST IMPROVEMENT LATER THIS MORNING BY 13Z OR 14Z.
DURING THE DAY TODAY WE ARE EXPECTING ANY LOW CLOUDS AND VSBY
RESTRICTIONS TO BE GONE QUICKLY. A NON CIG CUMULUS DECK IS FORECAST
TO DEVELOP. LEAST CONFIDENCE ABOUT THE LACK OF A CIG SERN TERMINALS.
NOT SURE IF THERE WILL BE A DISCERNIBLE SEA BREEZE, BUT THE OVERALL
GRADIENT WINDS SHOULD BE SOUTHEAST TO SOUTH WITH SPEEDS AROUND 10
KTS.
FOR TONIGHT WE ARE FOLLOWING THE SUGGESTION OF ONE MODEL THAT A
MVFR CIG SHOULD DEVELOP AND OR MOVE IN FROM THE OCEAN AND BAY
DURING THE EVENING HOURS. CONFIDENCE ON THE EVOLUTION IS GREATER
THAN AVERAGE ALTHOUGH THE SPECIFIC TIMING OF OCCURRENCE WE ARE
LESS CONFIDENT. SOME VSBY RESTRICTIONS DUE TO FOG ARE ALSO
POSSIBLE. WINDS WILL REMAIN FROM THE SOUTHEAST, BUT BECOME
LIGHTER.
OUTLOOK...
SAT AND SAT NIGHT...DETERIORATING CONDITIONS EXPECTED SATURDAY WITH
PERIODS OF MVFR/IFR IN SHOWERS AND SCT TSTMS. CONDITIONS MOSTLY
SUB-VFR SAT NIGHT WITH LOW CIGS/VSBYS.
SUN-MON...MOSTLY IFR CONDITIONS WITH LOW CIGS/VSBYS RAIN AND
GUSTY WINDS.
MON NGT-TUE...IMPROVEMENT TO VFR BY TUE ACROSS MOST AREAS BUT SCT SHOWERS
MAY CREATE LOWER CONDITIONS AT TIMES.
&&
.MARINE...
SUB SMALL CRAFT ADVISORY CONDITIONS ARE FORECAST TO CONTINUE TODAY
AND TONIGHT. WAVE WATCH GUIDANCE CONTINUES TO BE TOO HIGH WITH THE
EASTERLY SWELL AND WE ARE TAKING APPROXIMATELY A FOOT OFF THE
GUIDANCE. WINDS OVERALL TODAY SHOULD BE RELATIVELY LIGHT FROM THE
EAST AND SOUTHEAST. THERE WILL LIKELY BE AN INCREASE IN SPEED IN
DELAWARE BAY AGAIN LATER IN THE AFTERNOON AND EARLY IN THE EVENING
AS THE FLOW WILL BE UP THE BAY AGAIN.
WINDS SHOULD BACK MORE TO THE SOUTH TONIGHT, BUT OVERALL SPEEDS
SHOULD REMAIN LESS THAN 15KTS. SWELLS ARE NOT EXPECTED TO INCREASE
IN TIME TO CAUSE ANY SMALL CRAFT CONDITIONS.
OUTLOOK...
SMALL CRAFT CONDITIONS DEVELOPING SAT WITH GALES POSSIBLE SUN-MON.
A RETURN BACK TO SUB-SCA CONDITIONS BY TUE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...O`HARA
NEAR TERM...GIGI/HAYES
SHORT TERM...GIGI
LONG TERM...O`HARA
AVIATION...GIGI
MARINE...GIGI
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
707 AM EDT FRI APR 20 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL LINGER ACROSS THE REGION TODAY. A STRONG
LOW PRESSURE SYSTEM WILL THEN TRACK OVER THE AREA OR JUST OFFSHORE
SATURDAY NIGHT INTO SUNDAY FOLLOWED BY A COOLER AND DRIER HIGH
PRESSURE SYSTEM THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONLY MINOR CHANGES WERE MADE TO THE GRIDDED AND TEXT FORECASTS
WITH THE UPDATE THAT WAS JUST ISSUED.
A PRONOUNCED WEDGING PATTERN REMAINS IN PLACE ACROSS SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA EARLY THIS MORNING. SURFACE
PRESSURES ARE BEGINNING TO FALL WITHIN THE CORE OF THE IN-SITU
WEDGE HIGH PER 20/11Z ISALLOBARIC ANALYSIS WHICH SUGGESTS THE
WEDGE CORE IS SHOWING THE INITIAL SIGNS OF BREAKING DOWN.
WIDESPREAD LOW CLOUDS DOMINATE MUCH OF THE REGION WITH CEILING
HOVERING BETWEEN 500-800 FT AT MOST OBSERVATION SITES.
AS IS TYPICALLY THE CASE IN COLD AIR DAMMING SITUATIONS...THE
MODELS ARE STRUGGLING WITH HOW QUICKLY THE WEDGE WILL ERODE TODAY.
WITH SURFACE PRESSURES ALREADY FALLING ACROSS THE CAROLINA
PIEDMONT...IT WOULD APPEAR CONDITIONS WILL FAVOR A FAIRLY
PROGRESSIVE EROSION THIS MORNING...ESPECIALLY IN THE ABSENCE OF
LIGHT RAIN INDUCING DIABATIC EFFECTS. CLOUDS WILL GRADUALLY SCOUR
OUT AS THE WEDGE BREAKS DOWN AND THE MID-LEVEL SYNOPTIC FLOW
VEERS TO THE SOUTHWEST...BUT FORECAST SOUNDINGS SUGGEST LOW CLOUDS
WILL LIKELY BE REPLACED WITH A FAIRLY HEALTHY CUMULUS FIELD WITH
DEWPOINTS HOLDING IN THE 60S. WILL HIGHLIGHT CLOUDY SKIES BECOMING
PARTLY CLOUDY BY AFTERNOON ALL AREAS WITH HIGHS RANGING FROM THE
UPPER 70S NORTH TO THE LOWER 80S SOUTH. ISOLATED SHOWERS WILL BE
POSSIBLE JUST ABOUT ANYWHERE TODAY WITH ACTIVITY GENERALLY
REMAINING CONFINED AHEAD OF THE SEA BREEZE THIS AFTERNOON. WILL
MAINTAIN SLIGHT CHANCE POPS AWAY FROM THE COASTAL AREAS TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
ANY LINGERING SHOWER/TSTM ACTIVITY WILL QUICKLY DISSIPATE AFTER
SUNSET WITH THE LOSS OF INSOLATION. CUMULUS SHOULD ALSO QUICKLY
DIMINISH AS SURFACE HEATING CEASES. IT REMAINS TO BE SEEN HOW MUCH
STRATUS WILL REDEVELOP OVERNIGHT WITHIN THE STRENGTHENING
SOUTHWEST FLOW AHEAD OF AN APPROACHING COLD FRONT. NEITHER THE GFS
OR NAM MOS PACKAGES ARE EAGER ON LOW CLOUDS DEVELOPMENT TONIGHT...
BUT WITH STILL QUITE A BIT OF MOISTURE FORECAST TO LINGER
UNDERNEATH THE NOCTURNAL INVERSION THE POTENTIAL FOR LOW CLOUDS CAN
NOT BE COMPLETELY RULED OUT. WILL FORECAST MOSTLY CLEAR AND PARTLY
CLOUDY SKIES FOR NOW WITH LOWS IN THE LOWER-MID 60S.
THE WEATHER PATTERN WILL BECOME MUCH MORE ACTIVE ACROSS THE
EASTERN UNITED STATES BY THE WEEKEND. A SOUTHERN STREAM UPPER LOW
WILL SWEEP ACROSS THE GULF OF MEXICO ON SATURDAY...AS AN ASSOCIATED
SURFACE SYSTEM DEVELOPS OFF THE GULF COAST OF FLORIDA. THE FORECAST
AREA WILL BECOME LOCATED BETWEEN TWO AREAS OF DEEP MOISTURE ON
SATURDAY. ONE SWATH WILL BE SPREADING NORTHWARD ALONG THE SOUTHEAST
AND MID ATLANTIC COASTLINE...WHILE ANOTHER APPROACHES FROM THE
WEST COINCIDENT WITH THE NARROW LONGWAVE TROUGH AXIS. THERE ARE
SOME INDICATIONS IN NUMERICAL MODEL SOLUTIONS THAT THE REGION WILL
FALL WITHIN A BRIEF DRY SLOT ON SATURDAY...SOMEWHAT LIMITING RAIN
COVERAGE UNTIL BOTH THE SURFACE AND UPPER LEVEL SYSTEM SHIFT
ACROSS FLORIDA AND UP THE SOUTHEAST COASTLINE EARLY SUNDAY.
CONSIDERING THAT THE SURFACE AND UPPER LEVEL LOW ARE EXPECTED TO
TRACK TO THE SOUTH AND THEN OFF THE COAST OF THE FORECAST
AREA...WILL INDICATE THE BEST POTENTIAL FOR RAIN OVER THE WATERS
AND ADJACENT COASTAL COUNTIES INTO SATURDAY EVENING. ONCE THE
SURFACE LOW SHIFTS TOWARD THE SOUTH CAROLINA AND NORTH CAROLINA
COASTLINES ON SUNDAY...WRAP AROUND MOISTURE BEHIND THE LOW CENTER
WILL ALLOW PRECIPITATION TO SPREAD FARTHER INTO THE INLAND SOUTH
CAROLINA ZONES. AN EXAMINATION OF INSTABILITY PARAMETERS AND WIND
FIELDS SUGGESTS THAT MOST OF THE ORGANIZED SEVERE POTENTIAL WILL
BE CONFINED SOUTH OF THE FORECAST AREA OVER THE WEEKEND...AS
WOULD BE EXPECTED WITH THE MORE SOUTHERN TRACK OF THIS SYSTEM.
HAVE THUS LIMITED MENTION OF THUNDER TO SLIGHT CHANCE SATURDAY AND
SUNDAY.
AS THE CLOSED UPPER LOW LIFTS TOWARD THE SOUTHEAST COASTLINE ON
SUNDAY...IT EVENTUALLY BECOMES ABSORBED INTO A LARGER UPPER TROUGH
MOVING SOUTHWARD FROM CENTRAL CANADA SUNDAY NIGHT. THE SURFACE LOW
SYSTEM WILL RAPIDLY MOVE UP THE EAST COAST AND OUT OF THE AREA BY
MONDAY MORNING. HAVE INDICATED DECREASING RAIN CHANCES THROUGH THE
DAY SUNDAY...WITH POPS BELOW 15 PERCENT BY MONDAY MORNING.
LOWERING HEIGHTS AND FAIRLY IMPRESSIVE COLD ADVECTION FOR THIS
TIME OF YEAR IS EXPECTED EARLY NEXT WEEK BEHIND THE COASTAL SYSTEM.
WHILE HIGH TEMPERATURES WILL BE ABOVE AVERAGE ON SATURDAY...REACHING
THE LOWER 80S INLAND...HIGH TEMPERATURES WILL BE SUPPRESSED AROUND
70 DEGREES FOLLOWING THE SYSTEM SUNDAY AND MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
A BROAD UPPER TROUGH WILL LINGER ACROSS THE EASTERN UNITED STATES
THROUGH TUESDAY...SUPPORTING COOLER HIGH TEMPERATURES IN THE LOWER
70S. ONCE THE TROUGH AXIS SHIFTS OFF THE COAST MID WEEK...UPPER
RIDGING WILL BEGIN TO BUILD EASTWARD. THIS WILL ALLOW FOR A
WARMING TREND THROUGH THE END OF THE WEEK...WITH HIGH TEMPERATURES
RETURNING TO THE LOWER 80S BY THURSDAY AND FRIDAY. THERE IS SOME
MODEL DISAGREEMENT REGARDING A POTENTIAL WEAK BACKDOOR FRONT
SLIPPING INTO THE REGION THURSDAY AND FRIDAY. PREFER TO KEEP RAIN
CHANCES BELOW 15 PERCENT THROUGH THE EXTENDED FORECAST PERIOD
UNTIL MODEL CONSISTENCY REGARDING THIS SCENARIO IMPROVES.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
INCOMING GUIDANCE AND RUC SOUNDINGS SUGGEST IFR CIGS WILL QUICKLY
BREAK BY 15-16Z THIS MORNING AS THE WEDGE HIGH STEADILY BREAKS
DOWN. EXPECT VFR CONDITIONS TO DOMINATE THEREAFTER. THERE ARE SOME
CONCERNS FOR STRATUS REDEVELOPING EARLY SATURDAY WITH ABUNDANT
MOISTURE LIKELY BECMG PINNED UNDERNEATH A NOCTURNAL INVERSION.
TABULAR GUIDANCE IS NOT OVERLY BULLISH ON LOW CLOUDS OVERNIGHT...
SO WILL KEEP CONDITIONS VFR FOR NOW.
EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CIGS/VSBYS ARE POSSIBLE
AT BOTH TERMINALS SATURDAY NIGHT THROUGH SUNDAY MORNING DUE TO
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A LOW PRESSURE SYSTEM
MOVING UP THE SOUTHEAST COASTLINE.
&&
.MARINE...
NORTHEAST WINDS WILL GRADUALLY VEER TO THE SOUTHEAST TODAY AS THE
INLAND WEDGE BREAKS DOWN AND TURN SOUTHWEST BY TONIGHT. BOTH WINDS
AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS...ALTHOUGH
SEAS WILL BE DOMINATED BY A NORTHEAST SWELL WITH PERIODS OF 11-13
SECONDS.
SATURDAY THROUGH TUESDAY...WINDS AND SEAS WILL INCREASE LATE
SATURDAY...AS A STRENGTHENING LOW PRESSURE SYSTEM TRACKS FROM THE
NORTHEAST GULF OF MEXICO OVER OR JUST EAST OF THE WATERS SUNDAY.
SMALL CRAFT ADVISORIES MAY BE NEEDED AS EARLY AS SATURDAY NIGHT
DUE TO BUILDING SEAS...WITH WINDS POSSIBLY REACHING CRITERIA
SUNDAY AND MONDAY WITHIN COLD ADVECTION AND A TIGHT GRADIENT
BEHIND THE SYSTEM. EXPECT GRADUALLY IMPROVING CONDITIONS INTO
TUESDAY AS COASTAL LOW PULLS AWAY TO THE NORTHEAST.
RIP CURRENTS...INCREASING SWELLS COMBINED WITH ONSHORE FLOW AND
ASTRONOMICAL INFLUENCES WILL YIELD AN ENHANCED RISK FOR RIP
CURRENTS TODAY. AN ENHANCED RISK FOR RIP CURRENTS WILL REMAIN
THROUGH THE WEEKEND.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...79
AVIATION...
MARINE...79
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1253 PM CDT FRI APR 20 2012
.DISCUSSION...
ISSUED 949 AM CDT FRI APR 20 2012
MAIN CONCERN THIS MORNING IS WITH TEMPERATURES. THE COLD FRONT WAS
ROUGHLY ALONG OR JUST WEST OF THE I-57 CORRIDOR AS OF 9 AM.
TEMPERATURES AHEAD OF THE FRONT WERE APPROACHING 70 DEGREES IN THE
EXTREME SOUTHEAST CWA...WHERE CLOUDS HAVE ONLY RECENTLY BEGAN TO
THICKEN. BEHIND THE FRONT...TEMPERATURES HAVE DIPPED INTO THE 40S.
LATEST HRRR SHOWS THE FRONT REACHING LAWRENCEVILLE IN THE NOON TO
1 PM TIME FRAME. COLD AIR ADVECTION AND EXTENSIVE CLOUDINESS
BEHIND THE FRONT WILL RESULT IN LITTLE OR NO RISE IN TEMPERATURES
THIS AFTERNOON ACROSS THE NORTHWEST HALF OF THE CWA...WITH FALLING
TEMPERATURES IN THE SOUTHEAST HALF.
RAIN SHOWERS CONTINUE TO ADVANCE ACROSS THE CWA IN ROUGHLY A 50
MILE WIDE BAND...SO PRECIPITATION HAS LARGELY ENDED WEST OF A
BLOOMINGTON TO TAYLORVILLE LINE. MOST OF THE PRECIPITATION SHOULD
BE OUT OF THE CWA BY MID AFTERNOON...EXCEPT IN THE FAR SOUTHEAST.
ZONE/GRID UPDATES WILL BE OUT AROUND 10 AM TO UPDATE THE
TEMPERATURE AND RAINFALL TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 1253 PM CDT FRI APR 20 2012
COLD FRONT HAS PASSED ALL THE TAF SITES...SO MAIN CONCERN IS WITH
MVFR AND BORDERLINE IFR CEILINGS THE NEXT SEVERAL HOURS. LOWEST
CEILINGS AROUND 700-800 FEET LINGERING AT KDEC/KCMI WHERE THERE
WILL ALSO BE SOME LOWER VISIBILITIES IN RAIN SHOWERS THROUGH ABOUT
21Z. SATELLITE IMAGERY SHOWING CLOUDS BELOW 3000 FEET AS FAR
NORTHWEST AS CENTRAL IOWA. CEILINGS WILL GRADUALLY RISE THROUGH
THE MVFR RANGE THIS AFTERNOON...WITH CLOUDS SCATTERING OUT EARLY
THIS EVENING. HOWEVER...IT MAY TAKE UNTIL AROUND 07-09Z OR SO FOR
THIS TO OCCUR FURTHER EAST TOWARD KCMI.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 309 AM CDT FRI APR 20 2012
SHORT TERM...TODAY THROUGH SUNDAY
COLD FRONT WILL PUSH EASTWARD ACROSS THE AREA TODAY...ACCOMPANIED
BY A BAND OF LIGHT SHOWERS. 00Z UPPER AIR ANALYSIS SHOWS LIMITED
MOISTURE FOR THE FRONT TO WORK WITH...WITH ONLY A NARROW RIBBON OF
5-10C 850MB DEWPOINTS EXTENDING FROM TEXAS NORTHEASTWARD INTO
IOWA. IN ADDITION...00Z KILX AND KDVN UPPER AIR SOUNDINGS FEATURED
A VERY DRY LOW-LEVEL AIRMASS BELOW 600MB. HRRR AND 4KM WRF-NMM
BOTH SUGGEST THE BAND OF SHOWERS WILL GRADUALLY DISSIPATE AS IT
WORKS ITS WAY INTO THE DRIER ENVIRONMENT ACROSS CENTRAL ILLINOIS
THIS MORNING. LATEST RADAR MOSAIC CONTINUES TO INDICATE A WEAKENING
TREND...WHILE IR SATELLITE SHOWS WARMING CLOUD TOPS. END RESULT
WILL BE A BRIEF PERIOD OF SCATTERED SHOWERS ALONG AND IMMEDIATELY
BEHIND THE FRONT. RAINFALL TOTALS WILL REMAIN LIGHT...GENERALLY
UNDER ONE TENTH OF AN INCH. ONCE THE FRONT PASSES...BREEZY AND
COOLER CONDITIONS WILL SPILL INTO THE REGION LATER THIS MORNING
INTO THE AFTERNOON. WITH OVERCAST CONDITIONS AND NORTHWESTERLY
WINDS GUSTING TO 25 MPH AT TIMES...TEMPS WILL HOVER IN THE LOWER
TO MIDDLE 50S BEHIND THE FRONT.
EXTENSIVE CLOUD COVER BEHIND THE BOUNDARY WILL ENSURE MOSTLY
CLOUDY CONDITIONS THROUGH EARLY EVENING...WITH CLEARING SKIES
DEVELOPING ACROSS THE ILLINOIS RIVER VALLEY TOWARD MIDNIGHT...THEN
FURTHER EAST ACROSS THE REMAINDER OF THE AREA OVERNIGHT. PATCHY
FROST WILL BE POSSIBLE ALONG AND NORTHWEST OF A RUSHVILLE TO
BLOOMINGTON-NORMAL LINE...WHERE SKIES WILL CLEAR EARLIEST AND
WINDS WILL DIMINISH TO LESS THAN 5 MPH. OVERNIGHT LOWS WILL RANGE
FROM THE MIDDLE 30S NORTHWEST...TO THE LOWER 40S FAR SOUTHEAST.
COOL/DRY WEATHER WILL BE ON TAP FOR SATURDAY...WITH HIGHS ONLY
REACHING THE MIDDLE TO UPPER 50S. LOW TEMPS SATURDAY NIGHT WILL
LIKELY BE A COUPLE OF DEGREES WARMER THAN TONIGHT DUE TO CLOUD
COVER FROM AN APPROACHING UPPER-LEVEL DISTURBANCE...SO CHANCES FOR
FROST WILL BE REDUCED. IN FACT...MODELS ARE TRYING TO SQUEEZE OUT
SOME LIGHT QPF WITH THE APPROACHING WAVE...HOWEVER THINK AIRMASS
WILL BE TOO DRY TO SUPPORT MEASURABLE PRECIP...SO HAVE MAINTAINED A
DRY FORECAST.
LONG TERM...MONDAY THROUGH THURSDAY
DEEP UPPER LOW IS EXPECTED TO DEVELOP OVER THE EASTERN CONUS EARLY
NEXT WEEK...WITH MODELS STILL VARYING ON ITS EVENTUAL DEPARTURE.
GIVEN HIGHLY AMPLIFIED NATURE OF THE FLOW...THINK SLOWER IS THE
WAY TO GO. END RESULT WILL BE COOL/DRY WEATHER THROUGH AT LEAST
TUESDAY...WITH A MARKED WARMING TREND BEGINNING BY THE MIDDLE OF
THE WEEK AS UPPER HEIGHTS BEGIN TO RISE. HIGH TEMPS WILL START OUT
IN THE LOWER 60S ON MONDAY...THEN WILL CLIMB WELL INTO THE 70S BY
WEDNESDAY AND THURSDAY. RAIN CHANCES THROUGH THE PERIOD APPEAR TO
BE RATHER MINIMAL...WITH THE BEST SHOT AT PRECIP OCCURRING ON
WEDNESDAY AS WARMER AIRMASS BEGINS TO MAKE ITS RETURN.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
949 AM CDT FRI APR 20 2012
.DISCUSSION...
ISSUED 949 AM CDT FRI APR 20 2012
MAIN CONCERN THIS MORNING IS WITH TEMPERATURES. THE COLD FRONT WAS
ROUGHLY ALONG OR JUST WEST OF THE I-57 CORRIDOR AS OF 9 AM.
TEMPERATURES AHEAD OF THE FRONT WERE APPROACHING 70 DEGREES IN THE
EXTREME SOUTHEAST CWA...WHERE CLOUDS HAVE ONLY RECENTLY BEGAN TO
THICKEN. BEHIND THE FRONT...TEMPERATURES HAVE DIPPED INTO THE 40S.
LATEST HRRR SHOWS THE FRONT REACHING LAWRENCEVILLE IN THE NOON TO
1 PM TIME FRAME. COLD AIR ADVECTION AND EXTENSIVE CLOUDINESS
BEHIND THE FRONT WILL RESULT IN LITTLE OR NO RISE IN TEMPERATURES
THIS AFTERNOON ACROSS THE NORTHWEST HALF OF THE CWA...WITH FALLING
TEMPERATURES IN THE SOUTHEAST HALF.
RAIN SHOWERS CONTINUE TO ADVANCE ACROSS THE CWA IN ROUGHLY A 50
MILE WIDE BAND...SO PRECIPITATION HAS LARGELY ENDED WEST OF A
BLOOMINGTON TO TAYLORVILLE LINE. MOST OF THE PRECIPITATION SHOULD
BE OUT OF THE CWA BY MID AFTERNOON...EXCEPT IN THE FAR SOUTHEAST.
ZONE/GRID UPDATES WILL BE OUT AROUND 10 AM TO UPDATE THE
TEMPERATURE AND RAINFALL TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 654 AM CDT FRI APR 20 2012
A COLD FRONT HAS CLEARED KPIA/KBMI/KSPI TERMINALS...AND WILL CLEAR
KDEC/CMI WITHIN THE NEXT FEW HOURS. LIGHT SHOWERS END QUICKLY IN
THE WAKE OF THE FRONT...THOUGH A FEW HOURS OF IFR CIGS ARE LIKELY
BETWEEN WHEN THE RAIN ENDS AND SOME DRIER LOW LEVEL AIR FILTERS
IN. HIGH PRESSURE WILL PUSH INTO THE AREA LATER TONIGHT...
RESULTING IN GRADUAL CLEARING. GUSTY NORTHWEST WINDS IN THE WAKE
OF THE FRONT WILL TREND NORTHERLY AND BECOME LIGHT TONIGHT AS THE
HIGH PRESSURE BUILDS IN.
BAK
&&
.PREV DISCUSSION...
ISSUED 309 AM CDT FRI APR 20 2012
SHORT TERM...TODAY THROUGH SUNDAY
COLD FRONT WILL PUSH EASTWARD ACROSS THE AREA TODAY...ACCOMPANIED
BY A BAND OF LIGHT SHOWERS. 00Z UPPER AIR ANALYSIS SHOWS LIMITED
MOISTURE FOR THE FRONT TO WORK WITH...WITH ONLY A NARROW RIBBON OF
5-10C 850MB DEWPOINTS EXTENDING FROM TEXAS NORTHEASTWARD INTO
IOWA. IN ADDITION...00Z KILX AND KDVN UPPER AIR SOUNDINGS FEATURED
A VERY DRY LOW-LEVEL AIRMASS BELOW 600MB. HRRR AND 4KM WRF-NMM
BOTH SUGGEST THE BAND OF SHOWERS WILL GRADUALLY DISSIPATE AS IT
WORKS ITS WAY INTO THE DRIER ENVIRONMENT ACROSS CENTRAL ILLINOIS
THIS MORNING. LATEST RADAR MOSAIC CONTINUES TO INDICATE A WEAKENING
TREND...WHILE IR SATELLITE SHOWS WARMING CLOUD TOPS. END RESULT
WILL BE A BRIEF PERIOD OF SCATTERED SHOWERS ALONG AND IMMEDIATELY
BEHIND THE FRONT. RAINFALL TOTALS WILL REMAIN LIGHT...GENERALLY
UNDER ONE TENTH OF AN INCH. ONCE THE FRONT PASSES...BREEZY AND
COOLER CONDITIONS WILL SPILL INTO THE REGION LATER THIS MORNING
INTO THE AFTERNOON. WITH OVERCAST CONDITIONS AND NORTHWESTERLY
WINDS GUSTING TO 25 MPH AT TIMES...TEMPS WILL HOVER IN THE LOWER
TO MIDDLE 50S BEHIND THE FRONT.
EXTENSIVE CLOUD COVER BEHIND THE BOUNDARY WILL ENSURE MOSTLY
CLOUDY CONDITIONS THROUGH EARLY EVENING...WITH CLEARING SKIES
DEVELOPING ACROSS THE ILLINOIS RIVER VALLEY TOWARD MIDNIGHT...THEN
FURTHER EAST ACROSS THE REMAINDER OF THE AREA OVERNIGHT. PATCHY
FROST WILL BE POSSIBLE ALONG AND NORTHWEST OF A RUSHVILLE TO
BLOOMINGTON-NORMAL LINE...WHERE SKIES WILL CLEAR EARLIEST AND
WINDS WILL DIMINISH TO LESS THAN 5 MPH. OVERNIGHT LOWS WILL RANGE
FROM THE MIDDLE 30S NORTHWEST...TO THE LOWER 40S FAR SOUTHEAST.
COOL/DRY WEATHER WILL BE ON TAP FOR SATURDAY...WITH HIGHS ONLY
REACHING THE MIDDLE TO UPPER 50S. LOW TEMPS SATURDAY NIGHT WILL
LIKELY BE A COUPLE OF DEGREES WARMER THAN TONIGHT DUE TO CLOUD
COVER FROM AN APPROACHING UPPER-LEVEL DISTURBANCE...SO CHANCES FOR
FROST WILL BE REDUCED. IN FACT...MODELS ARE TRYING TO SQUEEZE OUT
SOME LIGHT QPF WITH THE APPROACHING WAVE...HOWEVER THINK AIRMASS
WILL BE TOO DRY TO SUPPORT MEASURABLE PRECIP...SO HAVE MAINTAINED A
DRY FORECAST.
LONG TERM...MONDAY THROUGH THURSDAY
DEEP UPPER LOW IS EXPECTED TO DEVELOP OVER THE EASTERN CONUS EARLY
NEXT WEEK...WITH MODELS STILL VARYING ON ITS EVENTUAL DEPARTURE.
GIVEN HIGHLY AMPLIFIED NATURE OF THE FLOW...THINK SLOWER IS THE
WAY TO GO. END RESULT WILL BE COOL/DRY WEATHER THROUGH AT LEAST
TUESDAY...WITH A MARKED WARMING TREND BEGINNING BY THE MIDDLE OF
THE WEEK AS UPPER HEIGHTS BEGIN TO RISE. HIGH TEMPS WILL START OUT
IN THE LOWER 60S ON MONDAY...THEN WILL CLIMB WELL INTO THE 70S BY
WEDNESDAY AND THURSDAY. RAIN CHANCES THROUGH THE PERIOD APPEAR TO
BE RATHER MINIMAL...WITH THE BEST SHOT AT PRECIP OCCURRING ON
WEDNESDAY AS WARMER AIRMASS BEGINS TO MAKE ITS RETURN.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
654 AM CDT FRI APR 20 2012
.DISCUSSION...
ISSUED 309 AM CDT FRI APR 20 2012
SHORT TERM...TODAY THROUGH SUNDAY
COLD FRONT WILL PUSH EASTWARD ACROSS THE AREA TODAY...ACCOMPANIED
BY A BAND OF LIGHT SHOWERS. 00Z UPPER AIR ANALYSIS SHOWS LIMITED
MOISTURE FOR THE FRONT TO WORK WITH...WITH ONLY A NARROW RIBBON OF
5-10C 850MB DEWPOINTS EXTENDING FROM TEXAS NORTHEASTWARD INTO
IOWA. IN ADDITION...00Z KILX AND KDVN UPPER AIR SOUNDINGS FEATURED
A VERY DRY LOW-LEVEL AIRMASS BELOW 600MB. HRRR AND 4KM WRF-NMM
BOTH SUGGEST THE BAND OF SHOWERS WILL GRADUALLY DISSIPATE AS IT
WORKS ITS WAY INTO THE DRIER ENVIRONMENT ACROSS CENTRAL ILLINOIS
THIS MORNING. LATEST RADAR MOSAIC CONTINUES TO INDICATE A WEAKENING
TREND...WHILE IR SATELLITE SHOWS WARMING CLOUD TOPS. END RESULT
WILL BE A BRIEF PERIOD OF SCATTERED SHOWERS ALONG AND IMMEDIATELY
BEHIND THE FRONT. RAINFALL TOTALS WILL REMAIN LIGHT...GENERALLY
UNDER ONE TENTH OF AN INCH. ONCE THE FRONT PASSES...BREEZY AND
COOLER CONDITIONS WILL SPILL INTO THE REGION LATER THIS MORNING
INTO THE AFTERNOON. WITH OVERCAST CONDITIONS AND NORTHWESTERLY
WINDS GUSTING TO 25 MPH AT TIMES...TEMPS WILL HOVER IN THE LOWER
TO MIDDLE 50S BEHIND THE FRONT.
EXTENSIVE CLOUD COVER BEHIND THE BOUNDARY WILL ENSURE MOSTLY
CLOUDY CONDITIONS THROUGH EARLY EVENING...WITH CLEARING SKIES
DEVELOPING ACROSS THE ILLINOIS RIVER VALLEY TOWARD MIDNIGHT...THEN
FURTHER EAST ACROSS THE REMAINDER OF THE AREA OVERNIGHT. PATCHY
FROST WILL BE POSSIBLE ALONG AND NORTHWEST OF A RUSHVILLE TO
BLOOMINGTON-NORMAL LINE...WHERE SKIES WILL CLEAR EARLIEST AND
WINDS WILL DIMINISH TO LESS THAN 5 MPH. OVERNIGHT LOWS WILL RANGE
FROM THE MIDDLE 30S NORTHWEST...TO THE LOWER 40S FAR SOUTHEAST.
COOL/DRY WEATHER WILL BE ON TAP FOR SATURDAY...WITH HIGHS ONLY
REACHING THE MIDDLE TO UPPER 50S. LOW TEMPS SATURDAY NIGHT WILL
LIKELY BE A COUPLE OF DEGREES WARMER THAN TONIGHT DUE TO CLOUD
COVER FROM AN APPROACHING UPPER-LEVEL DISTURBANCE...SO CHANCES FOR
FROST WILL BE REDUCED. IN FACT...MODELS ARE TRYING TO SQUEEZE OUT
SOME LIGHT QPF WITH THE APPROACHING WAVE...HOWEVER THINK AIRMASS
WILL BE TOO DRY TO SUPPORT MEASURABLE PRECIP...SO HAVE MAINTAINED A
DRY FORECAST.
LONG TERM...MONDAY THROUGH THURSDAY
DEEP UPPER LOW IS EXPECTED TO DEVELOP OVER THE EASTERN CONUS EARLY
NEXT WEEK...WITH MODELS STILL VARYING ON ITS EVENTUAL DEPARTURE.
GIVEN HIGHLY AMPLIFIED NATURE OF THE FLOW...THINK SLOWER IS THE
WAY TO GO. END RESULT WILL BE COOL/DRY WEATHER THROUGH AT LEAST
TUESDAY...WITH A MARKED WARMING TREND BEGINNING BY THE MIDDLE OF
THE WEEK AS UPPER HEIGHTS BEGIN TO RISE. HIGH TEMPS WILL START OUT
IN THE LOWER 60S ON MONDAY...THEN WILL CLIMB WELL INTO THE 70S BY
WEDNESDAY AND THURSDAY. RAIN CHANCES THROUGH THE PERIOD APPEAR TO
BE RATHER MINIMAL...WITH THE BEST SHOT AT PRECIP OCCURRING ON
WEDNESDAY AS WARMER AIRMASS BEGINS TO MAKE ITS RETURN.
BARNES
&&
.AVIATION...
ISSUED 654 AM CDT FRI APR 20 2012
A COLD FRONT HAS CLEARED KPIA/KBMI/KSPI TERMINALS...AND WILL CLEAR
KDEC/CMI WITHIN THE NEXT FEW HOURS. LIGHT SHOWERS END QUICKLY IN
THE WAKE OF THE FRONT...THOUGH A FEW HOURS OF IFR CIGS ARE LIKELY
BETWEEN WHEN THE RAIN ENDS AND SOME DRIER LOW LEVEL AIR FILTERS
IN. HIGH PRESSURE WILL PUSH INTO THE AREA LATER TONIGHT...
RESULTING IN GRADUAL CLEARING. GUSTY NORTHWEST WINDS IN THE WAKE
OF THE FRONT WILL TREND NORTHERLY AND BECOME LIGHT TONIGHT AS THE
HIGH PRESSURE BUILDS IN.
BAK
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
309 AM CDT FRI APR 20 2012
.DISCUSSION...
ISSUED 309 AM CDT FRI APR 20 2012
SHORT TERM...TODAY THROUGH SUNDAY
COLD FRONT WILL PUSH EASTWARD ACROSS THE AREA TODAY...ACCOMPANIED
BY A BAND OF LIGHT SHOWERS. 00Z UPPER AIR ANALYSIS SHOWS LIMITED
MOISTURE FOR THE FRONT TO WORK WITH...WITH ONLY A NARROW RIBBON OF
5-10C 850MB DEWPOINTS EXTENDING FROM TEXAS NORTHEASTWARD INTO
IOWA. IN ADDITION...00Z KILX AND KDVN UPPER AIR SOUNDINGS FEATURED
A VERY DRY LOW-LEVEL AIRMASS BELOW 600MB. HRRR AND 4KM WRF-NMM
BOTH SUGGEST THE BAND OF SHOWERS WILL GRADUALLY DISSIPATE AS IT
WORKS ITS WAY INTO THE DRIER ENVIRONMENT ACROSS CENTRAL ILLINOIS
THIS MORNING. LATEST RADAR MOSAIC CONTINUES TO INDICATE A WEAKENING
TREND...WHILE IR SATELLITE SHOWS WARMING CLOUD TOPS. END RESULT
WILL BE A BRIEF PERIOD OF SCATTERED SHOWERS ALONG AND IMMEDIATELY
BEHIND THE FRONT. RAINFALL TOTALS WILL REMAIN LIGHT...GENERALLY
UNDER ONE TENTH OF AN INCH. ONCE THE FRONT PASSES...BREEZY AND
COOLER CONDITIONS WILL SPILL INTO THE REGION LATER THIS MORNING
INTO THE AFTERNOON. WITH OVERCAST CONDITIONS AND NORTHWESTERLY
WINDS GUSTING TO 25 MPH AT TIMES...TEMPS WILL HOVER IN THE LOWER
TO MIDDLE 50S BEHIND THE FRONT.
EXTENSIVE CLOUD COVER BEHIND THE BOUNDARY WILL ENSURE MOSTLY
CLOUDY CONDITIONS THROUGH EARLY EVENING...WITH CLEARING SKIES
DEVELOPING ACROSS THE ILLINOIS RIVER VALLEY TOWARD MIDNIGHT...THEN
FURTHER EAST ACROSS THE REMAINDER OF THE AREA OVERNIGHT. PATCHY
FROST WILL BE POSSIBLE ALONG AND NORTHWEST OF A RUSHVILLE TO
BLOOMINGTON-NORMAL LINE...WHERE SKIES WILL CLEAR EARLIEST AND
WINDS WILL DIMINISH TO LESS THAN 5 MPH. OVERNIGHT LOWS WILL RANGE
FROM THE MIDDLE 30S NORTHWEST...TO THE LOWER 40S FAR SOUTHEAST.
COOL/DRY WEATHER WILL BE ON TAP FOR SATURDAY...WITH HIGHS ONLY
REACHING THE MIDDLE TO UPPER 50S. LOW TEMPS SATURDAY NIGHT WILL
LIKELY BE A COUPLE OF DEGREES WARMER THAN TONIGHT DUE TO CLOUD
COVER FROM AN APPROACHING UPPER-LEVEL DISTURBANCE...SO CHANCES FOR
FROST WILL BE REDUCED. IN FACT...MODELS ARE TRYING TO SQUEEZE OUT
SOME LIGHT QPF WITH THE APPROACHING WAVE...HOWEVER THINK AIRMASS
WILL BE TOO DRY TO SUPPORT MEASURABLE PRECIP...SO HAVE MAINTAINED A
DRY FORECAST.
LONG TERM...MONDAY THROUGH THURSDAY
DEEP UPPER LOW IS EXPECTED TO DEVELOP OVER THE EASTERN CONUS EARLY
NEXT WEEK...WITH MODELS STILL VARYING ON ITS EVENTUAL DEPARTURE.
GIVEN HIGHLY AMPLIFIED NATURE OF THE FLOW...THINK SLOWER IS THE
WAY TO GO. END RESULT WILL BE COOL/DRY WEATHER THROUGH AT LEAST
TUESDAY...WITH A MARKED WARMING TREND BEGINNING BY THE MIDDLE OF
THE WEEK AS UPPER HEIGHTS BEGIN TO RISE. HIGH TEMPS WILL START OUT
IN THE LOWER 60S ON MONDAY...THEN WILL CLIMB WELL INTO THE 70S BY
WEDNESDAY AND THURSDAY. RAIN CHANCES THROUGH THE PERIOD APPEAR TO
BE RATHER MINIMAL...WITH THE BEST SHOT AT PRECIP OCCURRING ON
WEDNESDAY AS WARMER AIRMASS BEGINS TO MAKE ITS RETURN.
BARNES
&&
.AVIATION...
ISSUED 1154 PM CDT THU APR 19 2012...FOR THE 06Z TAFS
THE SURFACE LOW HAS ENTERED FAR NW IL...WITH THE COLD FRONT ALONG
THE IL BORDER AND INTO EASTERN MISSOURI. SHOWERS ARE MAINLY IN A
NARROW LINE EXTENDING ALONG THE BEHIND THE FRONT FOR 20-30 MILES.
OVERALL...OUR WINDOW OF CHANCE FOR MEASURABLE RAIN AT ANY TAF SITE
LOOKS TO BE AROUND 3-4 HOURS AT MOST. WE DECIDED TO STILL INCLUDE
SOME PREVAILING RAIN AT ALL SITES AT SOME POINT BETWEEN 07Z AT PIA AND
14Z AT CMI. IT NOW APPEARS LIKELY THAT IFR CONDITIONS WILL DEVELOP
FOR AT LEAST A COUPLE HOURS BEHIND THE FRONT. 500-600FT CIGS HAVE
DEVELOPED ACROSS E IOWA/E MO...AND THAT LOW STRATUS SHOULD
PROGRESS EASTWARD ACROSS C IL LATER TONIGHT AND INTO FRIDAY
MORNING. DAYTIME MIXING AND POST FRONTAL SUBSIDENCE SHOULD HELP TO
MIX DRIER AIR TOWARD THE SURFACE TO RAISE LIFTED CONDENSATION
LEVELS /LCL/ TO AT LEAST MVFR.
WINDS WILL BE ON A NEARLY CONTINUOUS CHANGE THE REST OF THE NIGHT
AND FRIDAY MORNING...AS THEY SHIFT FROM SOUTHERLY TO SW...THEN TO
W-NW AFTER THE FRONT...WITH NORTH WINDS BY LATER AFTERNOON FRIDAY.
VFR CONDITIONS ARE EXPECTED TO DEVELOP FRI EVE FROM WEST TO
EAST...BUT CMI/DEC MAY NOT RAISE ABOVE MVFR BEFORE 06Z.
SHIMON
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
639 PM CDT SAT APR 21 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
PRIMARY CONCERN TONIGHT WILL BE THE EVOLUTION OF UPSTREAM SHORT
WAVE/PV ANOMALY...WHICH MODELS BRING RIGHT THROUGH IA LATER
TONIGHT. CURRENT MORE THERMODYNAMICALLY FORCED BAND OF PRECIP
SHOULD EXIT ERN FORECAST AREA BY 00Z FOLLOWED BY LINE OF SCATTERED
SHOWERS/STORMS FOCUSED ON LOW LEVEL CONVERGENCE WITH PASSAGE OF
TROUGH. 20Z SURFACE ANALYSIS PLACES ACTUAL COLD FRONT FROM LOW NEAR
FARGO BACK ALONG ND/SD BORDER. COULD SEE SOME BELOW SEVERE CRITERIA
HAIL/WIND WITH THESE STORMS NW...BUT DECREASING/INCREASING
MLCAPE/CIN RESPECTIVELY SHOULD GRADUALLY WEAKEN STORMS AS THEY GET
INTO CENTRAL IA. RUC MLCAPE APPEARS TO PEAK AT NO MORE THAN 300
J/KG AS IT ENTER FORECAST AREA. ATTENTION WILL THEN TURNS TO
FORCING AND MOISTURE 3KM AND BELOW ASSOCIATED WITH PASSAGE OF SHORT
WAVE WHICH MAINLY APPEARS TO AFFECT NERN HALF OF IA. HAVE HIGH
CHANCE/LIKELY POPS TONIGHT IN THESE AREAS...BUT FEEL THIS WILL BE
FOR A TRANSIENT LOW QPF EVENT.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
AMPLIFIED UPPER PATTERN OVER THE CONUS EARLY NEXT WEEK WITH UPPER
RIDGE CENTERED OVER THE CENTRAL ROCKIES AND A DEEP UPPER TROUGH OVER
THE EASTERN UNITED STATES. SHORTWAVE OVER THE UPPER MIDWEST TODAY IS
FORECAST TO CURVE OUT A DEEP UPPER LOW CENTERED NEAR THE EAST COAST
BY MONDAY. THIS WILL LEAVE CENTRAL IOWA IN INITIALLY NORTHERLY
UPPER FLOW WHICH SHOULD SLOWLY BECOME NORTHWESTERLY BY
TUESDAY/WEDNESDAY AS A SHORTWAVE FLATTENS THE UPPER RIDGE TO THE
WEST. THE MODELS SEEM TO BE IN FAIR AGREEMENT WITH THE GENERAL UPPER
PATTERN...BUT THERE ARE DIFFERENCES MID WEEK CONCERNING THE PASSAGE
OF A SIGNIFICANT COLD FRONT. THE 12Z OPERATIONAL GFS BRINGS A
STRONG CANADIAN HIGH DOWN INTO THE UPPER MIDWEST DURING THE
WEDNESDAY THROUGH FRIDAY TIME PERIOD. THE 12Z ECMWF IS SIMILAR TO
THE 12Z GFS CONCERNING THE PLACEMENT AND STRENGTH OF THE CANADIAN
HIGH.
12Z NAM/GFS BOTH LINGER PRECIPITATION OVER CENTRAL IOWA ON SUNDAY IN
THE VICINITY OF AN INVERTED TROUGH. THE TROUGH SHOULD WEAKEN DURING
THE DAY AS THE SURFACE RIDGE BUILDS IN. EXPECT CLOUDS ON SUNDAY
WITH SMALL SHOWER CHANCES THROUGH NOON. SKIES SHOULD CLEAR SUNDAY
NIGHT UNDER APPROACHING HIGH ALLOWING TEMPERATURES TO FALL NEAR
FREEZING IN SPOTS. CONDITIONS SHOULD BE FAVORABLE FOR FROST...LIGHT
WINDS AND CLEAR SKIES.
AS THE UPPER FLOW FLATTENS BY TUESDAY AND SURFACE AND LOW-LEVEL FLOW
BECOMES WEST SOUTHWEST WITH STRONG WARM ADVECTION...EXPECT
TEMPERATURES TO WARM INTO THE 80S OVER WESTERN IOWA.
MODEL UNCERTAINTY IN THE LONG RANGE...DAY SIX AND SEVEN...WILL
RESULT IN MODERATE POPS. NEXT WESTERN CONUS UPPER TROUGH AND
ACCOMPANYING SURFACE FEATURES SHOULD IMPACT CENTRAL IOWA DURING THIS
TIME PERIOD. IN ALL CASES...THE PATTERN SHOULD BECOME FAVORABLE FOR
THUNDERSTORMS BY THE END OF THE FORECAST PERIOD.
&&
.AVIATION...22/00Z
WEAK BROKEN LINE OF SHOWERS WILL QUICKLY PUSH EAST OVER THE NEXT
COUPLE OF HOURS. SHOULD BE EAST OF DSM AREA BY 01Z AT THE LATEST AND
THEN OTM/ALO AREAS BY AROUND 03Z. MAINLY EXPECTING A WIND SHIFT TO
THE WEST NORTHWEST WITH THE PASSING OF A WEAK TROUGH CAUSING THESE
SHOWERS. A COLD FRONT LOOKS TO SWING AROUND THE SHORTWAVE OVERNIGHT
NIGHT AND WILL BRING SOME IFR/MVFR CIGS PAST 06Z TO ALL TAF SITES.
925MB RH NEAR 100PERCENT THROUGH MID MORNING SUNDAY BEFORE SOME
MIXING HELPS LIFT THE CIGS TO VFR B/T 15-18Z SUNDAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...JOHNSON
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1225 PM CDT FRI APR 20 2012
.AVIATION...
MVFR CONDITIONS DUE TO CIGS AROUND 2KFT WILL GRADUALLY IMPROVE
TO VFR LATE THIS AFTERNOON AND EARLY THIS EVENING AS CLOUDS CLEAR
FROM WEST TO EAST. GUSTY NORTH WINDS WILL ALSO DIMINISH BY THIS
EVENING. WINDS WILL BECOME LIGHT SOUTH TO SOUTHEAST BY SATURDAY
MORNING.
A SURFACE RIDGE OVER THE NORTHERN PLAINS WILL MOVE SOUTHEAST AND
SHOULD BE CENTERED JUST WEST OF THE MISSISSIPPI RIVER BY SATURDAY
MORNING. CLEARING SKIES AND LIGHT WINDS ACCOMPANYING THE RIDGE WILL
CREATE FAVORABLE CONDITIONS FOR FROST LATE TONIGHT.
DLF
&&
.PREV DISCUSSION... /ISSUED 640 AM CDT FRI APR 20 2012/
UPDATE...
BASED ON RADAR AND RUC TRENDS THE THREAT OF MEASURABLE
PRECIPITATION FOR THE CWFA IS NOW OVER. RUC CONTINUES TO SHOW F
VECTOR CONVERGENCE AND REASONABLY LOW CONDENSATION PRESSURE
DEFICITS THIS MORNING WHICH MAY ALLOW PATCHY DRIZZLE OR SPRINKLES
TO BE SEEN. ANY PRECIP WILL END FROM WEST TO EAST DURING THE
MORNING HOURS.
DPROG/DT OF THE MODELS INDICATE HIGH LEVEL MOISTURE INCREASING
TONIGHT WHICH STRONGLY SUGGESTS THE CI/CS ASSOCIATED WITH THE
SHORTWAVE TOPPING THE RIDGE IN THE PAC NW WILL ARRIVE AFTER
MIDNIGHT. IF THIS TREND IS CORRECT...THE HIGH LEVEL CLOUD COVER
WOULD HAVE AN IMPACT ON TEMPERATURES TONIGHT WHICH WOULD THEN PLAY
SIGNIFICANTLY INTO ANY FROST AND FREEZE POTENTIAL.
AN UPDATE REFLECTING THE IMMEDIATE SHORT TERM TRENDS WILL BE
AVAILABLE SHORTLY. ..08..
AVIATION...
LIFR TO LOW MVFR CONDITIONS WILL SLOWLY IMPROVE TO VFR CONDITIONS
THROUGH 00Z/21 WITH GUSTY WINDS. PATCHY DRIZZLE OR SPRINKLES MAY BE
POSSIBLE THROUGH 18Z/20. AFT 00Z/21 WINDS WILL DIMINISH AS HIGH
PRESSURE QUICKLY MOVES THROUGH THE AREA. ..08..
PREV DISCUSSION... /ISSUED 345 AM CDT FRI APR 20 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS THE LOW JUST SOUTHEAST OF THE QUAD CITIES WITH
A WARM FRONT EAST TO THE SOUTH SUBURBS OF CHICAGO. THE COLD FRONT
RAN INTO SOUTHWEST MISSOURI. DEW POINTS AROUND THE FRONTS WERE IN
THE 50S WITH MAINLY 40S OVER MOST OF THE PLAINS AND MIDWEST. DEW
POINTS IN THE 30S WERE IN THE UPPER MIDWEST AND WESTERN GREAT LAKES.
RADAR TRENDS THE PAST SEVERAL HOURS SHOW A BACK EDGE OF THE MORE
SUBSTANTIAL PRECIPITATION FROM ROUGHLY KRFD TO KUIN. SFC OBS
REPORTED DZ OR VERY LIGHT RAIN BACK INTO EASTERN AND CENTRAL IOWA.
SHORT TERM...TODAY AND TONIGHT
RUC TRENDS WITH CONDENSATION PRESSURE DEFICITS HAVE BEEN USEFUL IN
DEPICTING PRECIPITATION TRENDS AND WERE USED FOR THE IMMEDIATE SHORT
TERM.
BASED ON RADAR AND RUC TRENDS...ANY MEASURABLE PRECIPITATION SHOULD
BE ACROSS THE FAR EAST AND SOUTHEAST PARTS OF THE CWFA AT 12Z. THE
REMAINDER OF THE AREA SHOULD SEE DRIZZLE/SPRINKLES DUE TO LOW
CONDENSATION PRESSURE DEFICITS COMBINED WITH FORCING AND F VECTOR
CONVERGENCE THROUGH MID MORNING. AS CONDENSATION PRESSURE DEFICITS
RISE THE PRECIPITATION WILL END FROM WEST TO EAST FROM LATE MORNING
THROUGH MID DAY.
CLOUD COVER AND INITIAL PRECIPITATION THIS MORNING WILL HOLD
TEMPERATURES DOWN BUT CLEARING DURING THE MID TO LATE AFTERNOON FROM
WEST TO EAST SHOULD ALLOW TEMPERATURES TO CLIMB INTO THE LOW TO MID
50S.
TONIGHT...QUIET AND CHILLY CONDITIONS WILL BE SEEN ACROSS THE AREA.
HIGH PRESSURE OVER THE AREA WILL ALLOW WINDS TO BECOME LIGHT WITH
FROST POSSIBLE. THE POSSIBILITY DOES EXIST THAT A FREEZE MAY OCCUR
ACROSS ABOUT THE NORTHERN QUARTER TO THIRD OF THE CWFA. HOWEVER...
THE MODELS ARE SHOWING INCREASES IN MOISTURE ALOFT AFTER MIDNIGHT
SUGGESTING CI/CS MOVING INTO THE AREA. IF THIS OCCURS TEMPERATURES
WOULD BE HELD UP...POSSIBLY ABOVE FREEZING.
GIVEN THIS UNCERTAINTY...ANY DECISION REGARDING FROST/FREEZE
HEADLINES WILL BE DEFERRED TO THE NEXT SHIFT. ..08..
LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
OUR NEXT PRECIPITATION CHANCES COME ON SATURDAY AND SATURDAY
NIGHT AS A WEAK SHORTWAVE WITH A WING OF WARM AIR ADVECTION AND
ISENTROPIC LIFT AHEAD OF THE SHORTWAVE. THERE IS JUST ENOUGH
MOISTURE FOR THIS TO SQUEEZE OUT SOME SHOWERS...THOUGH MODELS ARE
SHOWING SOME DIFFERENCES WITH THIS RELATIVELY WEAK FEATURE. NAM
IS THE ODD MODEL OUT THIS MORNING...AS IT IS FARTHER EAST AND
SLIGHTLY WEAKER THAN THE OTHER MODELS HAVE. HAVE IN GENERAL TRIED
TO FOLLOW A BLEND OF THE GFS/ECMWF/UKMET SOLUTIONS ON THIS
FEATURE. WHILE THE MID LEVEL CONVERGENCE SEEMS TO LINGER ON SUNDAY
AND SUNDAY NIGHT...IT DOES NOT APPEAR THAT THERE IS ENOUGH
MOISTURE TO GET ANY SHOWERS GOING AGAIN ON SUNDAY. FOR NOW THE
TIME RANGE WITH THE HIGHEST POTENTIAL FOR PRECIPITATION IS
SATURDAY NIGHT. TEMPERATURES TO BE A LITTLE COOLER ON SATURDAY
WITH THE BAND OF PRECIPITATION MOVING INTO THE AREA...BUT
GRADUALLY WARM FOR SUNDAY AS THE MID LEVEL WARM AIR ADVECTION SETS
BACK IN QUICKLY BEHIND THE SHORTWAVE.
WE REMAIN IN STRONG NORTHWEST FLOW ON MONDAY THROUGH AT LEAST
WEDNESDAY...WITH STRONGLY AMPLIFIED FLOW OVER THE CONUS...WITH THE
DEEP TROUGH OVER THE EAST AND STRONG RIDGE OUT WEST. IT IS
DIFFICULT TO GET A GULF FEED FROM A SOUTHWEST LOW LEVEL FEED OUT OF
THIS TYPE OF SYSTEM...SO MOST SYSTEMS ARE GOING TO HAVE TO DRAG IN
THEIR OWN MOISTURE FROM THE PACIFIC...AND THEN MAKE THEIR WAY OVER
THE RIDGE. TUESDAY AND WEDNESDAY HAVE ANOTHER CHANCE FOR
PRECIPITATION AS WE GET A SLIGHTLY STRONGER SHORTWAVE THROUGH HERE.
SOME MODELS ARE EVEN BRINGING A SURFACE LOW ACROSS THE REGION.
OTHERS SIMPLY SETTLE A TROUGH AXIS ACROSS THE AREA. TOUGH CALL FOR
NOW...AND HAVE MAINTAINED SLIGHT CHANCE OR EVEN LOW CHANCE POP FOR
THE SOUTHERN PORTIONS OF THE FORECAST AREA. AS MOISTURE IS A
LIMITING FACTOR FOR THIS STORM...DO NOT ANTICIPATE HAVING ENOUGH
MOISTURE TO ACT UPON...NOR CAN WE EXPECT A REINFORCING SYSTEM TO
MOVE THROUGH LATER ON IN THE EVENING. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
640 AM CDT FRI APR 20 2012
.UPDATE...
BASED ON RADAR AND RUC TRENDS THE THREAT OF MEASURABLE
PRECIPITATION FOR THE CWFA IS NOW OVER. RUC CONTINUES TO SHOW F
VECTOR CONVERGENCE AND REASONABLY LOW CONDENSATION PRESSURE
DEFICITS THIS MORNING WHICH MAY ALLOW PATCHY DRIZZLE OR SPRINKLES
TO BE SEEN. ANY PRECIP WILL END FROM WEST TO EAST DURING THE
MORNING HOURS.
DPROG/DT OF THE MODELS INDICATE HIGH LEVEL MOISTURE INCREASING
TONIGHT WHICH STRONGLY SUGGESTS THE CI/CS ASSOCIATED WITH THE
SHORTWAVE TOPPING THE RIDGE IN THE PAC NW WILL ARRIVE AFTER
MIDNIGHT. IF THIS TREND IS CORRECT...THE HIGH LEVEL CLOUD COVER
WOULD HAVE AN IMPACT ON TEMPERATURES TONIGHT WHICH WOULD THEN PLAY
SIGNIFICANTLY INTO ANY FROST AND FREEZE POTENTIAL.
AN UPDATE REFLECTING THE IMMEDIATE SHORT TERM TRENDS WILL BE
AVAILABLE SHORTLY. ..08..
&&
.AVIATION...
LIFR TO LOW MVFR CONDITIONS WILL SLOWLY IMPROVE TO VFR CONDITIONS
THROUGH 00Z/21 WITH GUSTY WINDS. PATCHY DRIZZLE OR SPRINKLES MAY BE
POSSIBLE THROUGH 18Z/20. AFT 00Z/21 WINDS WILL DIMINISH AS HIGH
PRESSURE QUICKLY MOVES THROUGH THE AREA. ..08..
&&
.PREV DISCUSSION... /ISSUED 345 AM CDT FRI APR 20 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS THE LOW JUST SOUTHEAST OF THE QUAD CITIES WITH
A WARM FRONT EAST TO THE SOUTH SUBURBS OF CHICAGO. THE COLD FRONT
RAN INTO SOUTHWEST MISSOURI. DEW POINTS AROUND THE FRONTS WERE IN
THE 50S WITH MAINLY 40S OVER MOST OF THE PLAINS AND MIDWEST. DEW
POINTS IN THE 30S WERE IN THE UPPER MIDWEST AND WESTERN GREAT LAKES.
RADAR TRENDS THE PAST SEVERAL HOURS SHOW A BACK EDGE OF THE MORE
SUBSTANTIAL PRECIPITATION FROM ROUGHLY KRFD TO KUIN. SFC OBS
REPORTED DZ OR VERY LIGHT RAIN BACK INTO EASTERN AND CENTRAL IOWA.
SHORT TERM...TODAY AND TONIGHT
RUC TRENDS WITH CONDENSATION PRESSURE DEFICITS HAVE BEEN USEFUL IN
DEPICTING PRECIPITATION TRENDS AND WERE USED FOR THE IMMEDIATE SHORT
TERM.
BASED ON RADAR AND RUC TRENDS...ANY MEASURABLE PRECIPITATION SHOULD
BE ACROSS THE FAR EAST AND SOUTHEAST PARTS OF THE CWFA AT 12Z. THE
REMAINDER OF THE AREA SHOULD SEE DRIZZLE/SPRINKLES DUE TO LOW
CONDENSATION PRESSURE DEFICITS COMBINED WITH FORCING AND F VECTOR
CONVERGENCE THROUGH MID MORNING. AS CONDENSATION PRESSURE DEFICITS
RISE THE PRECIPITATION WILL END FROM WEST TO EAST FROM LATE MORNING
THROUGH MID DAY.
CLOUD COVER AND INITIAL PRECIPITATION THIS MORNING WILL HOLD
TEMPERATURES DOWN BUT CLEARING DURING THE MID TO LATE AFTERNOON FROM
WEST TO EAST SHOULD ALLOW TEMPERATURES TO CLIMB INTO THE LOW TO MID
50S.
TONIGHT...QUIET AND CHILLY CONDITIONS WILL BE SEEN ACROSS THE AREA.
HIGH PRESSURE OVER THE AREA WILL ALLOW WINDS TO BECOME LIGHT WITH
FROST POSSIBLE. THE POSSIBILITY DOES EXIST THAT A FREEZE MAY OCCUR
ACROSS ABOUT THE NORTHERN QUARTER TO THIRD OF THE CWFA. HOWEVER...
THE MODELS ARE SHOWING INCREASES IN MOISTURE ALOFT AFTER MIDNIGHT
SUGGESTING CI/CS MOVING INTO THE AREA. IF THIS OCCURS TEMPERATURES
WOULD BE HELD UP...POSSIBLY ABOVE FREEZING.
GIVEN THIS UNCERTAINTY...ANY DECISION REGARDING FROST/FREEZE
HEADLINES WILL BE DEFERRED TO THE NEXT SHIFT. ..08..
LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
OUR NEXT PRECIPITATION CHANCES COME ON SATURDAY AND SATURDAY
NIGHT AS A WEAK SHORTWAVE WITH A WING OF WARM AIR ADVECTION AND
ISENTROPIC LIFT AHEAD OF THE SHORTWAVE. THERE IS JUST ENOUGH
MOISTURE FOR THIS TO SQUEEZE OUT SOME SHOWERS...THOUGH MODELS ARE
SHOWING SOME DIFFERENCES WITH THIS RELATIVELY WEAK FEATURE. NAM
IS THE ODD MODEL OUT THIS MORNING...AS IT IS FARTHER EAST AND
SLIGHTLY WEAKER THAN THE OTHER MODELS HAVE. HAVE IN GENERAL TRIED
TO FOLLOW A BLEND OF THE GFS/ECMWF/UKMET SOLUTIONS ON THIS
FEATURE. WHILE THE MID LEVEL CONVERGENCE SEEMS TO LINGER ON SUNDAY
AND SUNDAY NIGHT...IT DOES NOT APPEAR THAT THERE IS ENOUGH
MOISTURE TO GET ANY SHOWERS GOING AGAIN ON SUNDAY. FOR NOW THE
TIME RANGE WITH THE HIGHEST POTENTIAL FOR PRECIPITATION IS
SATURDAY NIGHT. TEMPERATURES TO BE A LITTLE COOLER ON SATURDAY
WITH THE BAND OF PRECIPITATION MOVING INTO THE AREA...BUT
GRADUALLY WARM FOR SUNDAY AS THE MID LEVEL WARM AIR ADVECTION SETS
BACK IN QUICKLY BEHIND THE SHORTWAVE.
WE REMAIN IN STRONG NORTHWEST FLOW ON MONDAY THROUGH AT LEAST
WEDNESDAY...WITH STRONGLY AMPLIFIED FLOW OVER THE CONUS...WITH THE
DEEP TROUGH OVER THE EAST AND STRONG RIDGE OUT WEST. IT IS
DIFFICULT TO GET A GULF FEED FROM A SOUTHWEST LOW LEVEL FEED OUT OF
THIS TYPE OF SYSTEM...SO MOST SYSTEMS ARE GOING TO HAVE TO DRAG IN
THEIR OWN MOISTURE FROM THE PACIFIC...AND THEN MAKE THEIR WAY OVER
THE RIDGE. TUESDAY AND WEDNESDAY HAVE ANOTHER CHANCE FOR
PRECIPITATION AS WE GET A SLIGHTLY STRONGER SHORTWAVE THROUGH HERE.
SOME MODELS ARE EVEN BRINGING A SURFACE LOW ACROSS THE REGION.
OTHERS SIMPLY SETTLE A TROUGH AXIS ACROSS THE AREA. TOUGH CALL FOR
NOW...AND HAVE MAINTAINED SLIGHT CHANCE OR EVEN LOW CHANCE POP FOR
THE SOUTHERN PORTIONS OF THE FORECAST AREA. AS MOISTURE IS A
LIMITING FACTOR FOR THIS STORM...DO NOT ANTICIPATE HAVING ENOUGH
MOISTURE TO ACT UPON...NOR CAN WE EXPECT A REINFORCING SYSTEM TO
MOVE THROUGH LATER ON IN THE EVENING. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
345 AM CDT FRI APR 20 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS THE LOW JUST SOUTHEAST OF THE QUAD CITIES WITH
A WARM FRONT EAST TO THE SOUTH SUBURBS OF CHICAGO. THE COLD FRONT
RAN INTO SOUTHWEST MISSOURI. DEW POINTS AROUND THE FRONTS WERE IN
THE 50S WITH MAINLY 40S OVER MOST OF THE PLAINS AND MIDWEST. DEW
POINTS IN THE 30S WERE IN THE UPPER MIDWEST AND WESTERN GREAT LAKES.
RADAR TRENDS THE PAST SEVERAL HOURS SHOW A BACK EDGE OF THE MORE
SUBSTANTIAL PRECIPITATION FROM ROUGHLY KRFD TO KUIN. SFC OBS
REPORTED DZ OR VERY LIGHT RAIN BACK INTO EASTERN AND CENTRAL IOWA.
&&
.SHORT TERM...TODAY AND TONIGHT
RUC TRENDS WITH CONDENSATION PRESSURE DEFICITS HAVE BEEN USEFUL IN
DEPICTING PRECIPITATION TRENDS AND WERE USED FOR THE IMMEDIATE SHORT
TERM.
BASED ON RADAR AND RUC TRENDS...ANY MEASURABLE PRECIPITATION SHOULD
BE ACROSS THE FAR EAST AND SOUTHEAST PARTS OF THE CWFA AT 12Z. THE
REMAINDER OF THE AREA SHOULD SEE DRIZZLE/SPRINKLES DUE TO LOW
CONDENSATION PRESSURE DEFICITS COMBINED WITH FORCING AND F VECTOR
CONVERGENCE THROUGH MID MORNING. AS CONDENSATION PRESSURE DEFICITS
RISE THE PRECIPITATION WILL END FROM WEST TO EAST FROM LATE MORNING
THROUGH MID DAY.
CLOUD COVER AND INITIAL PRECIPITATION THIS MORNING WILL HOLD
TEMPERATURES DOWN BUT CLEARING DURING THE MID TO LATE AFTERNOON FROM
WEST TO EAST SHOULD ALLOW TEMPERATURES TO CLIMB INTO THE LOW TO MID
50S.
TONIGHT...QUIET AND CHILLY CONDITIONS WILL BE SEEN ACROSS THE AREA.
HIGH PRESSURE OVER THE AREA WILL ALLOW WINDS TO BECOME LIGHT WITH
FROST POSSIBLE. THE POSSIBILITY DOES EXIST THAT A FREEZE MAY OCCUR
ACROSS ABOUT THE NORTHERN QUARTER TO THIRD OF THE CWFA. HOWEVER...
THE MODELS ARE SHOWING INCREASES IN MOISTURE ALOFT AFTER MIDNIGHT
SUGGESTING CI/CS MOVING INTO THE AREA. IF THIS OCCURS TEMPERATURES
WOULD BE HELD UP...POSSIBLY ABOVE FREEZING.
GIVEN THIS UNCERTAINTY...ANY DECISION REGARDING FROST/FREEZE
HEADLINES WILL BE DEFERRED TO THE NEXT SHIFT. ..08..
.LONG TERM...SATURDAY THROUGH NEXT THURSDAY...
OUR NEXT PRECIPITATION CHANCES COME ON SATURDAY AND SATURDAY
NIGHT AS A WEAK SHORTWAVE WITH A WING OF WARM AIR ADVECTION AND
ISENTROPIC LIFT AHEAD OF THE SHORTWAVE. THERE IS JUST ENOUGH
MOISTURE FOR THIS TO SQUEEZE OUT SOME SHOWERS...THOUGH MODELS ARE
SHOWING SOME DIFFERENCES WITH THIS RELATIVELY WEAK FEATURE. NAM
IS THE ODD MODEL OUT THIS MORNING...AS IT IS FARTHER EAST AND
SLIGHTLY WEAKER THAN THE OTHER MODELS HAVE. HAVE IN GENERAL TRIED
TO FOLLOW A BLEND OF THE GFS/ECMWF/UKMET SOLUTIONS ON THIS
FEATURE. WHILE THE MID LEVEL CONVERGENCE SEEMS TO LINGER ON SUNDAY
AND SUNDAY NIGHT...IT DOES NOT APPEAR THAT THERE IS ENOUGH
MOISTURE TO GET ANY SHOWERS GOING AGAIN ON SUNDAY. FOR NOW THE
TIME RANGE WITH THE HIGHEST POTENTIAL FOR PRECIPITATION IS
SATURDAY NIGHT. TEMPERATURES TO BE A LITTLE COOLER ON SATURDAY
WITH THE BAND OF PRECIPITATION MOVING INTO THE AREA...BUT
GRADUALLY WARM FOR SUNDAY AS THE MID LEVEL WARM AIR ADVECTION SETS
BACK IN QUICKLY BEHIND THE SHORTWAVE.
WE REMAIN IN STRONG NORTHWEST FLOW ON MONDAY THROUGH AT LEAST
WEDNESDAY...WITH STRONGLY AMPLIFIED FLOW OVER THE CONUS...WITH THE
DEEP TROUGH OVER THE EAST AND STRONG RIDGE OUT WEST. IT IS
DIFFICULT TO GET A GULF FEED FROM A SOUTHWEST LOW LEVEL FEED OUT OF
THIS TYPE OF SYSTEM...SO MOST SYSTEMS ARE GOING TO HAVE TO DRAG IN
THEIR OWN MOISTURE FROM THE PACIFIC...AND THEN MAKE THEIR WAY OVER
THE RIDGE. TUESDAY AND WEDNESDAY HAVE ANOTHER CHANCE FOR
PRECIPITATION AS WE GET A SLIGHTLY STRONGER SHORTWAVE THROUGH HERE.
SOME MODELS ARE EVEN BRINGING A SURFACE LOW ACROSS THE REGION.
OTHERS SIMPLY SETTLE A TROUGH AXIS ACROSS THE AREA. TOUGH CALL FOR
NOW...AND HAVE MAINTAINED SLIGHT CHANCE OR EVEN LOW CHANCE POP FOR
THE SOUTHERN PORTIONS OF THE FORECAST AREA. AS MOISTURE IS A
LIMITING FACTOR FOR THIS STORM...DO NOT ANTICIPATE HAVING ENOUGH
MOISTURE TO ACT UPON...NOR CAN WE EXPECT A REINFORCING SYSTEM TO
MOVE THROUGH LATER ON IN THE EVENING. ..LE..
&&
.AVIATION...
LIFR TO BORDERLINE MVFR CONDITIONS WILL BE SEEN THROUGH 18Z/20 WITH
CONDITIONS SLOWLY IMPROVING TO VFR. DZ OR SPRINKLES IS EXPECTED AT
ALL TAF SITES THROUGH 18Z/20 BEFORE ENDING. LIGHT WINDS AFT SUNSET
MAY RESULT IN FROST ON NON HANGARED ACFT AFT 06Z/21. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
333 AM CDT FRI APR 20 2012
.SYNOPSIS...
ISSUED AT 331 AM CDT FRI APR 20 2012
A LARGE TROUGH ACROSS THE CENTRAL PLAINS STATES WAS OBSERVED ON LAST
EVENING`S 00 UTC OBJECTIVE ANALYSIS. ALTHOUGH SOME RESPECTABLE
MOISTURE WAS PRESENT IN THE MID LEVELS, THE LOWER TO MIDDLE
TROPOSPHERE WAS QUITE DRY AS NOTED BY THE DRY INTRUSION ON THE 00
UTC KDDC SOUNDING. A NORTHERLY JET STREAK WAS CROSSING THE ROCKIES.
AT THE LEADING EDGE OF THIS JET STREAK WAS SOME ENHANCED CLOUD COVER
AND SCATTERED SHOWERS ASSOCIATED WITH THE FRONT LEFT UPPER DIVERGENT
FEATURE OF THE JET OVER WESTERN NEBRASKA AND NORTHWEST KANSAS.
SURFACE HIGH PRESSURE WAS ALSO SLIDING SOUTHWARD FROM THE NORTHERN
HIGH PLAINS, IN AN AIRMASS THAT SAW TEMPERATURES DIPPING INTO THE
40S ACROSS JUST ABOUT ALL OF WESTERN KANSAS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 331 AM CDT FRI APR 20 2012
CHANCES FOR LIGHT RAIN SHOWERS WILL DWINDLE TO NEAR NONEXISTENT AS
WE HEAD INTO THIS MORNING. THE FOCUSING MECHANISM WILL BE FATHER TO
THE EAST AND DEEP NORTHWEST FLOW WILL BECOME QUICKLY ESTABLISHED
OVER WESTERN KANSAS BY AROUND 15 UTC. AT THE SURFACE, NORTHERLY FLOW
WILL PERSIST THROUGH THE DAY AS SURFACE HIGH PRESSURE MOVES THROUGH
THE MISSOURI RIVER BASIN. AS WESTERN KANSAS ENDS UP ON THE WESTERN
DIES OF THE UPPER JET, PLENTY OS INSOLATION WILL BE AVAILABLE TODAY
AND TEMPERATURES WOULD WARM NICELY INTO THE 60S. THE ONLY CAVEAT
WILL BE TO WHAT EXTENT LOW STRATUS AFFECTS THE AREA IF AT ALL,
THROUGH THE MIDDLE MORNING. THERE WILL BE SOME SLIGHTLY DRIER AIR
ADVECTING INTO THE AREA, BUT THERE IS NOT A SIGNIFICANT AIRMASS
CHANGE TODAY AS THE FRONT THAT PASSED YESTERDAY MORNING REMAINS THE
FOCUS FOR THUNDERSTORMS OVER EASTERN OKLAHOMA. WINDS ARE GENERALLY
EXPECTED IN THE 10 TO 20 MPH RANGE THROUGH THE AFTERNOON. WESTERN
KANSAS ENDS UP FARTHER UNDER THE SURFACE RIDGE TONIGHT AS WINDS BACK
TO THE SOUTH AND BECOME LIGHT SOUTHWEST BY EARLY SATURDAY MORNING.
DEW POINTS IN THE UPPER 30S AND LOW 40S APPEAR HIGH ENOUGH THAT
SUFFICIENT COOLING FOR FROST IS NOT LIKELY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 246 AM CDT FRI APR 20 2012
AS THE EXTENDED FORECAST PERIOD STARTS OUT ON SATURDAY MORNING,
CLEAR SKIES, LIGHT SOUTHWEST WINDS AND COOL TEMPERATURES IN THE
UPPER 30S NORTH TO AROUND 40 DEGREES SOUTH CAN BE EXPECTED.
SATURDAY WILL SEE A SURFACE TROUGH MOVE ACROSS MOST OF THE CWA
AND WINDS WILL SHIFT TO THE NORTHWEST DURING SATURDAY AFTERNOON. A
FEW CIRRUS CLOUDS MAY PASS OVERHEAD IN THE NORTHERN CWA LATE
SATURDAY, BUT WILL NOT HAVE ANY SIGNIFICANT INFLUENCE ON MAX
TEMPS. HIGHS ON SATURDAY WILL BE IN THE MID 70S IN THE OUR NORTH
AND RANGE TO THE UPPER 70S IN OUR SOUTHWESTERN CWA. A LARGE UPPER
LEVEL HIGH PRESSURE SYSTEM WILL BEGIN TO BUILD OVER THE 4-CORNERS
AREA SUNDAY, AND THIS WILL ALLOW A SURFACE WARM FRONT TO PUSH
THROUGH WESTERN KANSAS SUNDAY INTO TUESDAY. MIN TEMPS SUNDAY
SHOULD BE IN THE MID 40S TO LOWER 50S, FOLLOWED BY HIGHS ON SUNDAY
IN THE UPPER 70S TO LOWER 80S. THEN ON MONDAY WE WILL BE WITHIN
THE WARM SECTOR OF THE WARM FRONT, ALLOWING SUNNY SKIES AND SOUTH
WINDS TO EVOLVE BY THE AFTERNOON. ONE OR BOTH MONDAY OR TUESDAY
AFTERNOON`S COULD BECOME BREEZY. MAX TEMPS MONDAY WILL TOP OUT IN
THE MID 70S TO NEAR 80 DEGREES. LOWS FOR BOTH TUESDAY AND
WEDNESDAY MORNINGS WILL BE IN THE MID TO UPPER 50S, AND WILL BE
VERY SIMILAR FOR THURSDAY AND FRIDAY. MAXIMUM TEMPERATURES FOR THE
TUESDAY THROUGH THURSDAY PERIOD WILL BE WARM, GENERALLY IN THE MID
TO UPPER 80S. A SOUTHERLY LOW LEVEL FLOW WILL EXIST TUESDAY
THROUGH THURSDAY, WITH MODEL PROGGED TEMPS IN THE 16C TO 24C RANGE
DURING THE AFTERNOONS.
BASICALLY, I SIMPLY LOADED THE CREXTENDFCST_INIT PROCEDURE AND WENT
WITH THOSE GRIDS. THERE WAS A SMALL BULLSEYE OF 20 PERCENT POPS
IN OUR SOUTHEASTERN CWA FOR THURSDAY, BUT I REDUCED THOSE POPS TO
LESS THAN 15 PERCENT AS THE MODELS DID NOT SUPPORT ANY RAIN THEN.
THUS, THE FORECAST WILL BE DRY SATURDAY THROUGH THURSDAY. STRONG
HIGH PRESSURE ANCHORED TO OUR WEST WILL DOMINATE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1242 AM CDT FRI APR 20 2012
WHAT APPEARS TO BE A SLOWLY EXPANDING AREA OF MVFR STRATUS IS MOVING
SOUTHWESTWARD FROM NORTH CENTRAL KANSAS AT THIS TIME. THE SURFACE
OBSERVATIONS INDICATE THE REGION REMAINS IN A WEAK NORTHEAST SURFACE
FLOW. THE RUC CEILING CLOUD FORECAST ARE INDICATING THIS AREA WOULD
EXPAND ACROSS THE LARGER PORTION OF WEST CENTRAL KANSAS BY AROUND 8
OR 9 UTC AS THE SURFACE HIGH PRESSURE RIDGE BUILDS OVER THE AREA.
THIS SOLUTION SEEMS REASONABLE GIVEN THE UPPER THICK CLOUD COVER
APPEARS SCATTERED AT BEST AND ADDITIONAL COOLING IS LIKELY. WE HAVE
RELATIVELY LOW CONFIDENCE IN HOW THE STRATUS FIELD WILL EVOLVE
OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 39 76 49 / 20 0 0 0
GCK 67 40 77 47 / 10 0 0 0
EHA 68 41 79 50 / 10 0 0 0
LBL 68 40 78 51 / 10 0 0 0
HYS 64 38 76 47 / 10 0 0 0
P28 66 41 75 49 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...BURKE
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
253 AM CDT FRI APR 20 2012
...UPDATED THE EXTENDED DISCUSSION...
.SYNOPSIS...
ISSUED AT 1219 PM CDT THU APR 19 2012
UPPER AIR ANALYSIS AT 12Z THURSDAY INDICATED AN UPPER LEVEL JET
EXTENDED FROM WASHINGTON STATE SOUTHEAST INTO NORTHEASTERN
NEVADA. NEAR THE LEFT EXIT REGION OF THIS JET A -26 TO -28C 500MB
THERMAL TROUGH WAS LOCATED OVER MONTANA. 40 TO 50 METER HEIGHT
FALLS WERE ALSO OBSERVED AT RAPID CITY SOUTH DAKOTA AND DENVER
COLORADO WHILE ACROSS ALONG THE PACIFIC NORTHWEST 50 TO 70 METER
HEIGHT RISES WERE OCCURRING. IN THE CENTRAL PLAINS AT 12Z THURSDAY
BOTH THE 850MB AND 700MB LEVELS INDICATED AN AREA OF MOISTURE WAS
LOCATED NEAR A 850-700MB BAROCLINIC ZONE THAT EXTENDED FROM
NORTHEAST COLORADO INTO CENTRAL NEBRASKA. AT 13Z A SURFACE A COLD
FRONT EXTENDED FROM JUST WEST OF HAYS SOUTH ACROSS THE DODGE CITY
AREA INTO THE PANHANDLE OF TEXAS AND OKLAHOMA.
&&
.UPDATE...
ISSUED AT 1134 PM CDT THU APR 19 2012
INFRARED SATELLITE IMAGERY AS WELL A REGIONAL RADAR AND METAR
OBSERVATIONS SHOW A PICTURE THIS EVENING OF SHOWERS BEING ABLE TO
MAKE PRECIPITATION REACH THE GROUND ACROSS WESTERN NEBRASKA AND
NORTHEAST COLORADO. THAT REGION WILL BE BEST CENTERED IN THE LEFT
FRONT QUADRANT OF THE UPPER LEVEL JET AS IT DIVES SOUTH OVERNIGHT.
A PERUSAL OF THE MODELS, INCLUDING THE LATEST ARW-WRF/NMM-WRF FOCUS
PRECIPITATION CHANCES WITH A COMPACT AREA OF LIFT PROBABLY
ASSOCIATED WITH THE THERMALLY INDIRECT TRANSVERSE CIRCULATION THAT
REMAINS BETTER TIED TO NORTHWEST KANSAS. ADDITIONALLY THE LAST FEW
HOURS, IT APPEAR THAT THE NAM AND OTHER MODELS HAVE SIGNIFICANTLY
OVER FORECAST THE QPF SO FAR THIS EVENING, PERHAPS OWING TO THE
NOTICEABLE DRY LAYER BETWEEN 800 AND 600 MB ON THE 00 UTC KDDC
SOUNDING. AS A RESULT, WE`LL CONTINUE THE THE DOWNTREND ON
PROBABILITIES FOR MEASURABLE PRECIPITATION OVERNIGHT WITH LESS THAN 20
PERCENT AREAL COVERAGE FOR SHOWERS, AS WEAK HIGH PRESSURE
CONTINUES TO SETTLE ACROSS THE AREA OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 152 PM CDT THU APR 19 2012
12Z NAM AND GFS REMAINS FAIRLY CONSISTENT WITH PREVIOUS RUNS IN
DEVELOPING CONVECTION LATE THIS AFTERNOON OVER THE HIGHER TERRAIN
OF COLORADO AS AN UPPER LEVEL JET APPROACHES THE ROCKIES. ANOTHER
AREA OF LATE DAY CONVECTION WILL ALSO BE POSSIBLE NEAR A COLD
FRONT WHICH WAS CROSSING SOUTH CENTRAL KANSAS AS OF 18Z. AT THIS
TIME IT APPEARS BASED ON THE HRRR AND NAM THIS FRONT WILL BE EAST
OF THE PRATT AND MEDICINE LODGE AREAS BY 00Z SO ANY PRECIPITATION
THAT WILL DEVELOP ALONG THIS BOUNDARY IS GOING TO OCCUR EAST OF
THESE LOCATIONS. FURTHER WEST BEHIND THIS FRONT THERE WILL STILL BE
SOME WEAK MID LEVEL INSTABILITY BASED ON MODEL SOUNDINGS EARLY
TONIGHT AND THE NAM EVEN GENERATES SOME VERY LIGHT QPF IN THIS AREA
OF INSTABILITY. AT THIS TIME GIVEN THE DRY AIR FORECAST BELOW THE
800MB LEVEL AM THINKING ONLY CLOUDS AND POSSIBLY VIRGA BUT WILL
CONTINUE TO MONITOR THIS AND ADJUST AS NEEDED FOR THE FIRST FEW
HOURS OF THE EVENING PERIOD.
CONVECTION DEVELOPING FURTHER WEST NEAR THE LEFT EXIT REGION OF
AN UPPER LEVEL JET APPEAR TO STAY WEST OF THE COLORADO BORDER
THROUGH 00Z. THESE STORMS ARE THEN FORECAST TO SPREAD EAST INTO
WESTERN KANSAS OVERNIGHT AS A 500MB THERMAL THROUGH WHICH WAS
LOCATED IN MONTANA AT 12Z THURSDAY MOVES SOUTHEAST INTO WESTERN
KANSAS. TRACK OF THIS UPPER TROUGH SUGGESTS PRECIPITATION CHANCES
WILL CONTINUE THROUGH EARLY FRIDAY AFTERNOON...ESPECIALLY EAST OF
HIGHWAY 283. THE PREVIOUS FORECAST HAS A DECENT HANDLE ON THE
EVOLUTION OF THIS PRECIPITATION SPREADING EAST ACROSS WESTERN
KANSAS LATER TONIGHT AND EARLY FRIDAY SO WILL STAY CLOSE TO THE
PREVIOUS TREND. DID HOWEVER POSTPONE THE ONSET OF THE
PRECIPITATION ACROSS THE FAR WEST UNTIL AFTER 00Z.
AS THE PRECIPITATION ENDS FROM WEST TO EAST THE SKIES ARE
EXPECTED TO CLEAR AS SUBSIDENCE DEVELOPS BEHIND THE UPPER LEVEL
TROUGH. BASED ON THE 18Z FRIDAY AND 00Z SATURDAY 925-950M
TEMPERATURES AND CLEARING SKIES WILL CONTINUE TO FAVOR HIGHS IN
THE MID 60S ACROSS MUCH OF WESTERN KANSAS. FURTHER EAST UPPER 50S
TO LOWER 60S APPEAR MORE REASONABLE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 246 AM CDT FRI APR 20 2012
AS THE EXTENDED FORECAST PERIOD STARTS OUT ON SATURDAY MORNING,
CLEAR SKIES, LIGHT SOUTHWEST WINDS AND COOL TEMPERATURES IN THE
UPPER 30S NORTH TO AROUND 40 DEGREES SOUTH CAN BE EXPECTED.
SATURDAY WILL SEE A SURFACE TROUGH MOVE ACROSS MOST OF THE CWA
AND WINDS WILL SHIFT TO THE NORTHWEST DURING SATURDAY AFTERNOON. A
FEW CIRRUS CLOUDS MAY PASS OVERHEAD IN THE NORTHERN CWA LATE
SATURDAY, BUT WILL NOT HAVE ANY SIGNIFICANT INFLUENCE ON MAX
TEMPS. HIGHS ON SATURDAY WILL BE IN THE MID 70S IN THE OUR NORTH
AND RANGE TO THE UPPER 70S IN OUR SOUTHWESTERN CWA. A LARGE UPPER
LEVEL HIGH PRESSURE SYSTEM WILL BEGIN TO BUILD OVER THE 4-CORNERS
AREA SUNDAY, AND THIS WILL ALLOW A SURFACE WARM FRONT TO PUSH
THROUGH WESTERN KANSAS SUNDAY INTO TUESDAY. MIN TEMPS SUNDAY
SHOULD BE IN THE MID 40S TO LOWER 50S, FOLLOWED BY HIGHS ON SUNDAY
IN THE UPPER 70S TO LOWER 80S. THEN ON MONDAY WE WILL BE WITHIN
THE WARM SECTOR OF THE WARM FRONT, ALLOWING SUNNY SKIES AND SOUTH
WINDS TO EVOLVE BY THE AFTERNOON. ONE OR BOTH MONDAY OR TUESDAY
AFTERNOON`S COULD BECOME BREEZY. MAX TEMPS MONDAY WILL TOP OUT IN
THE MID 70S TO NEAR 80 DEGREES. LOWS FOR BOTH TUESDAY AND
WEDNESDAY MORNINGS WILL BE IN THE MID TO UPPER 50S, AND WILL BE
VERY SIMILAR FOR THURSDAY AND FRIDAY. MAXIMUM TEMPERATURES FOR THE
TUESDAY THROUGH THURSDAY PERIOD WILL BE WARM, GENERALLY IN THE MID
TO UPPER 80S. A SOUTHERLY LOW LEVEL FLOW WILL EXIST TUESDAY
THROUGH THURSDAY, WITH MODEL PROGGED TEMPS IN THE 16C TO 24C RANGE
DURING THE AFTERNOONS.
BASICALLY, I SIMPLY LOADED THE CREXTENDFCST_INIT PROCEDURE AND WENT
WITH THOSE GRIDS. THERE WAS A SMALL BULLSEYE OF 20 PERCENT POPS
IN OUR SOUTHEASTERN CWA FOR THURSDAY, BUT I REDUCED THOSE POPS TO
LESS THAN 15 PERCENT AS THE MODELS DID NOT SUPPORT ANY RAIN THEN.
THUS, THE FORECAST WILL BE DRY SATURDAY THROUGH THURSDAY. STRONG
HIGH PRESSURE ANCHORED TO OUR WEST WILL DOMINATE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1242 AM CDT FRI APR 20 2012
WHAT APPEARS TO BE A SLOWLY EXPANDING AREA OF MVFR STRATUS IS MOVING
SOUTHWESTWARD FROM NORTH CENTRAL KANSAS AT THIS TIME. THE SURFACE
OBSERVATIONS INDICATE THE REGION REMAINS IN A WEAK NORTHEAST SURFACE
FLOW. THE RUC CEILING CLOUD FORECAST ARE INDICATING THIS AREA WOULD
EXPAND ACROSS THE LARGER PORTION OF WEST CENTRAL KANSAS BY AROUND 8
OR 9 UTC AS THE SURFACE HIGH PRESSURE RIDGE BUILDS OVER THE AREA.
THIS SOLUTION SEEMS REASONABLE GIVEN THE UPPER THICK CLOUD COVER
APPEARS SCATTERED AT BEST AND ADDITIONAL COOLING IS LIKELY. WE HAVE
RELATIVELY LOW CONFIDENCE IN HOW THE STRATUS FIELD WILL EVOLVE
OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 39 76 49 / 20 0 0 0
GCK 67 40 77 47 / 10 0 0 0
EHA 68 41 79 50 / 10 0 0 0
LBL 68 40 78 51 / 10 0 0 0
HYS 64 38 76 47 / 10 0 0 0
P28 66 41 75 49 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RUSSELL
SHORT TERM...BURGERT
LONG TERM...BURKE
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1244 AM CDT FRI APR 20 2012
...UPDATED FOR AVIATION...
.SYNOPSIS...
ISSUED AT 1219 PM CDT THU APR 19 2012
UPPER AIR ANALYSIS AT 12Z THURSDAY INDICATED AN UPPER LEVEL JET
EXTENDED FROM WASHINGTON STATE SOUTHEAST INTO NORTHEASTERN
NEVADA. NEAR THE LEFT EXIT REGION OF THIS JET A -26 TO -28C 500MB
THERMAL TROUGH WAS LOCATED OVER MONTANA. 40 TO 50 METER HEIGHT
FALLS WERE ALSO OBSERVED AT RAPID CITY SOUTH DAKOTA AND DENVER
COLORADO WHILE ACROSS ALONG THE PACIFIC NORTHWEST 50 TO 70 METER
HEIGHT RISES WERE OCCURRING. IN THE CENTRAL PLAINS AT 12Z THURSDAY
BOTH THE 850MB AND 700MB LEVELS INDICATED AN AREA OF MOISTURE WAS
LOCATED NEAR A 850-700MB BAROCLINIC ZONE THAT EXTENDED FROM
NORTHEAST COLORADO INTO CENTRAL NEBRASKA. AT 13Z A SURFACE A COLD
FRONT EXTENDED FROM JUST WEST OF HAYS SOUTH ACROSS THE DODGE CITY
AREA INTO THE PANHANDLE OF TEXAS AND OKLAHOMA.
&&
.UPDATE...
ISSUED AT 1134 PM CDT THU APR 19 2012
INFRARED SATELLITE IMAGERY AS WELL A REGIONAL RADAR AND METAR
OBSERVATIONS SHOW A PICTURE THIS EVENING OF SHOWERS BEING ABLE TO
MAKE PRECIPITATION REACH THE GROUND ACROSS WESTERN NEBRASKA AND
NORTHEAST COLORADO. THAT REGION WILL BE BEST CENTERED IN THE LEFT
FRONT QUADRANT OF THE UPPER LEVEL JET AS IT DIVES SOUTH OVERNIGHT.
A PERUSAL OF THE MODELS, INCLUDING THE LATEST ARW-WRF/NMM-WRF FOCUS
PRECIPITATION CHANCES WITH A COMPACT AREA OF LIFT PROBABLY
ASSOCIATED WITH THE THERMALLY INDIRECT TRANSVERSE CIRCULATION THAT
REMAINS BETTER TIED TO NORTHWEST KANSAS. ADDITIONALLY THE LAST FEW
HOURS, IT APPEAR THAT THE NAM AND OTHER MODELS HAVE SIGNIFICANTLY
OVER FORECAST THE QPF SO FAR THIS EVENING, PERHAPS OWING TO THE
NOTICEABLE DRY LAYER BETWEEN 800 AND 600 MB ON THE 00 UTC KDDC
SOUNDING. AS A RESULT, WE`LL CONTINUE THE THE DOWNTREND ON
PROBABILITIES FOR MEASURABLE PRECIPITATION OVERNIGHT WITH LESS THAN 20
PERCENT AREAL COVERAGE FOR SHOWERS, AS WEAK HIGH PRESSURE
CONTINUES TO SETTLE ACROSS THE AREA OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 152 PM CDT THU APR 19 2012
12Z NAM AND GFS REMAINS FAIRLY CONSISTENT WITH PREVIOUS RUNS IN
DEVELOPING CONVECTION LATE THIS AFTERNOON OVER THE HIGHER TERRAIN
OF COLORADO AS AN UPPER LEVEL JET APPROACHES THE ROCKIES. ANOTHER
AREA OF LATE DAY CONVECTION WILL ALSO BE POSSIBLE NEAR A COLD
FRONT WHICH WAS CROSSING SOUTH CENTRAL KANSAS AS OF 18Z. AT THIS
TIME IT APPEARS BASED ON THE HRRR AND NAM THIS FRONT WILL BE EAST
OF THE PRATT AND MEDICINE LODGE AREAS BY 00Z SO ANY PRECIPITATION
THAT WILL DEVELOP ALONG THIS BOUNDARY IS GOING TO OCCUR EAST OF
THESE LOCATIONS. FURTHER WEST BEHIND THIS FRONT THERE WILL STILL BE
SOME WEAK MID LEVEL INSTABILITY BASED ON MODEL SOUNDINGS EARLY
TONIGHT AND THE NAM EVEN GENERATES SOME VERY LIGHT QPF IN THIS AREA
OF INSTABILITY. AT THIS TIME GIVEN THE DRY AIR FORECAST BELOW THE
800MB LEVEL AM THINKING ONLY CLOUDS AND POSSIBLY VIRGA BUT WILL
CONTINUE TO MONITOR THIS AND ADJUST AS NEEDED FOR THE FIRST FEW
HOURS OF THE EVENING PERIOD.
CONVECTION DEVELOPING FURTHER WEST NEAR THE LEFT EXIT REGION OF
AN UPPER LEVEL JET APPEAR TO STAY WEST OF THE COLORADO BORDER
THROUGH 00Z. THESE STORMS ARE THEN FORECAST TO SPREAD EAST INTO
WESTERN KANSAS OVERNIGHT AS A 500MB THERMAL THROUGH WHICH WAS
LOCATED IN MONTANA AT 12Z THURSDAY MOVES SOUTHEAST INTO WESTERN
KANSAS. TRACK OF THIS UPPER TROUGH SUGGESTS PRECIPITATION CHANCES
WILL CONTINUE THROUGH EARLY FRIDAY AFTERNOON...ESPECIALLY EAST OF
HIGHWAY 283. THE PREVIOUS FORECAST HAS A DECENT HANDLE ON THE
EVOLUTION OF THIS PRECIPITATION SPREADING EAST ACROSS WESTERN
KANSAS LATER TONIGHT AND EARLY FRIDAY SO WILL STAY CLOSE TO THE
PREVIOUS TREND. DID HOWEVER POSTPONE THE ONSET OF THE
PRECIPITATION ACROSS THE FAR WEST UNTIL AFTER 00Z.
AS THE PRECIPITATION ENDS FROM WEST TO EAST THE SKIES ARE
EXPECTED TO CLEAR AS SUBSIDENCE DEVELOPS BEHIND THE UPPER LEVEL
TROUGH. BASED ON THE 18Z FRIDAY AND 00Z SATURDAY 925-950M
TEMPERATURES AND CLEARING SKIES WILL CONTINUE TO FAVOR HIGHS IN
THE MID 60S ACROSS MUCH OF WESTERN KANSAS. FURTHER EAST UPPER 50S
TO LOWER 60S APPEAR MORE REASONABLE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 245 PM CDT THU APR 19 2012
"WARM AND DRY" CAN DESCRIBE MOST OF THE EXTENDED PERIOD. WE WILL
SEE MODERATING TEMPERATURES OVER THE WEEKEND AS SURFACE LEE
TROUGHING STRENGTHENS. THE MAIN HEAT STORY BEGINS TUESDAY AND
CONTINUES THROUGH THE REST OF THE EXTENDED PERIOD AS 500 HPA
GEOPOTENTIAL HEIGHTS INCREASE IN RESPONSE TO AN AMPLIFIED RIDGE
BUILDING OVER THE ROCKIES. 850 HPA TEMPERATURES START AROUND 26-28
DEG C TUESDAY AND PEAK AROUND 28-30 DEG C BY THE END OF NEXT WEEK.
THIS SUPPORTS MIX DOWN TEMPERATURES WELL INTO THE 80S DEG F AND
MOST LIKELY SOME LOCATIONS WILL SEE >90 DEG F TEMPS. OVERNIGHT LOWS
THROUGH THE EXTENDED PERIOD WILL BE MILD AS MODERATE DEWPOINTS AND
SOUTHERLY WINDS CONTINUE. WILL KEEP SILENT POPS IN AS ANY UPPER LEVEL
FORCING REMAINS TO BE UNSEEN AND WEAK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1242 AM CDT FRI APR 20 2012
WHAT APPEARS TO BE A SLOWLY EXPANDING AREA OF MVFR STRATUS IS MOVING
SOUTHWESTWARD FROM NORTH CENTRAL KANSAS AT THIS TIME. THE SURFACE
OBSERVATIONS INDICATE THE REGION REMAINS IN A WEAK NORTHEAST SURFACE
FLOW. THE RUC CEILING CLOUD FORECAST ARE INDICATING THIS AREA WOULD
EXPAND ACROSS THE LARGER PORTION OF WEST CENTRAL KANSAS BY AROUND 8
OR 9 UTC AS THE SURFACE HIGH PRESSURE RIDGE BUILDS OVER THE AREA.
THIS SOLUTION SEEMS REASONABLE GIVEN THE UPPER THICK CLOUD COVER
APPEARS SCATTERED AT BEST AND ADDITIONAL COOLING IS LIKELY. WE HAVE
RELATIVELY LOW CONFIDENCE IN HOW THE STRATUS FIELD WILL EVOLVE
OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 76 49 80 / 0 0 0 0
GCK 40 77 47 81 / 0 0 0 0
EHA 41 79 50 82 / 0 0 0 0
LBL 40 78 51 82 / 0 0 0 0
HYS 38 76 47 77 / 0 0 0 0
P28 41 75 49 79 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RUSSELL
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1137 PM CDT THU APR 19 2012
...UPDATED FOR PRECIPITATION TRENDS...
.SYNOPSIS...
ISSUED AT 1219 PM CDT THU APR 19 2012
UPPER AIR ANALYSIS AT 12Z THURSDAY INDICATED AN UPPER LEVEL JET
EXTENDED FROM WASHINGTON STATE SOUTHEAST INTO NORTHEASTERN
NEVADA. NEAR THE LEFT EXIT REGION OF THIS JET A -26 TO -28C 500MB
THERMAL TROUGH WAS LOCATED OVER MONTANA. 40 TO 50 METER HEIGHT
FALLS WERE ALSO OBSERVED AT RAPID CITY SOUTH DAKOTA AND DENVER
COLORADO WHILE ACROSS ALONG THE PACIFIC NORTHWEST 50 TO 70 METER
HEIGHT RISES WERE OCCURRING. IN THE CENTRAL PLAINS AT 12Z THURSDAY
BOTH THE 850MB AND 700MB LEVELS INDICATED AN AREA OF MOISTURE WAS
LOCATED NEAR A 850-700MB BAROCLINIC ZONE THAT EXTENDED FROM
NORTHEAST COLORADO INTO CENTRAL NEBRASKA. AT 13Z A SURFACE A COLD
FRONT EXTENDED FROM JUST WEST OF HAYS SOUTH ACROSS THE DODGE CITY
AREA INTO THE PANHANDLE OF TEXAS AND OKLAHOMA.
&&
.UPDATE...
ISSUED AT 1134 PM CDT THU APR 19 2012
INFRARED SATELLITE IMAGERY AS WELL A REGIONAL RADAR AND METAR
OBSERVATIONS SHOW A PICTURE THIS EVENING OF SHOWERS BEING ABLE TO
MAKE PRECIPITATION REACH THE GROUND ACROSS WESTERN NEBRASKA AND
NORTHEAST COLORADO. THAT REGION WILL BE BEST CENTERED IN THE LEFT
FRONT QUADRANT OF THE UPPER LEVEL JET AS IT DIVES SOUTH OVERNIGHT.
A PERUSAL OF THE MODELS, INCLUDING THE LATEST ARW-WRF/NMM-WRF FOCUS
PRECIPITATION CHANCES WITH A COMPACT AREA OF LIFT PROBABLY
ASSOCIATED WITH THE THERMALLY INDIRECT TRANSVERSE CIRCULATION THAT
REMAINS BETTER TIED TO NORTHWEST KANSAS. ADDITIONALLY THE LAST FEW
HOURS, IT APPEAR THAT THE NAM AND OTHER MODELS HAVE SIGNIFICANTLY
OVER FORECAST THE QPF SO FAR THIS EVENING, PERHAPS OWING TO THE
NOTICEABLE DRY LAYER BETWEEN 800 AND 600 MB ON THE 00 UTC KDDC
SOUNDING. AS A RESULT, WE`LL CONTINUE THE THE DOWNTREND ON
PROBABILITIES FOR MEASURABLE PRECIPITATION OVERNIGHT WITH LESS THAN 20
PERCENT AREAL COVERAGE FOR SHOWERS, AS WEAK HIGH PRESSURE
CONTINUES TO SETTLE ACROSS THE AREA OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 152 PM CDT THU APR 19 2012
12Z NAM AND GFS REMAINS FAIRLY CONSISTENT WITH PREVIOUS RUNS IN
DEVELOPING CONVECTION LATE THIS AFTERNOON OVER THE HIGHER TERRAIN
OF COLORADO AS AN UPPER LEVEL JET APPROACHES THE ROCKIES. ANOTHER
AREA OF LATE DAY CONVECTION WILL ALSO BE POSSIBLE NEAR A COLD
FRONT WHICH WAS CROSSING SOUTH CENTRAL KANSAS AS OF 18Z. AT THIS
TIME IT APPEARS BASED ON THE HRRR AND NAM THIS FRONT WILL BE EAST
OF THE PRATT AND MEDICINE LODGE AREAS BY 00Z SO ANY PRECIPITATION
THAT WILL DEVELOP ALONG THIS BOUNDARY IS GOING TO OCCUR EAST OF
THESE LOCATIONS. FURTHER WEST BEHIND THIS FRONT THERE WILL STILL BE
SOME WEAK MID LEVEL INSTABILITY BASED ON MODEL SOUNDINGS EARLY
TONIGHT AND THE NAM EVEN GENERATES SOME VERY LIGHT QPF IN THIS AREA
OF INSTABILITY. AT THIS TIME GIVEN THE DRY AIR FORECAST BELOW THE
800MB LEVEL AM THINKING ONLY CLOUDS AND POSSIBLY VIRGA BUT WILL
CONTINUE TO MONITOR THIS AND ADJUST AS NEEDED FOR THE FIRST FEW
HOURS OF THE EVENING PERIOD.
CONVECTION DEVELOPING FURTHER WEST NEAR THE LEFT EXIT REGION OF
AN UPPER LEVEL JET APPEAR TO STAY WEST OF THE COLORADO BORDER
THROUGH 00Z. THESE STORMS ARE THEN FORECAST TO SPREAD EAST INTO
WESTERN KANSAS OVERNIGHT AS A 500MB THERMAL THROUGH WHICH WAS
LOCATED IN MONTANA AT 12Z THURSDAY MOVES SOUTHEAST INTO WESTERN
KANSAS. TRACK OF THIS UPPER TROUGH SUGGESTS PRECIPITATION CHANCES
WILL CONTINUE THROUGH EARLY FRIDAY AFTERNOON...ESPECIALLY EAST OF
HIGHWAY 283. THE PREVIOUS FORECAST HAS A DECENT HANDLE ON THE
EVOLUTION OF THIS PRECIPITATION SPREADING EAST ACROSS WESTERN
KANSAS LATER TONIGHT AND EARLY FRIDAY SO WILL STAY CLOSE TO THE
PREVIOUS TREND. DID HOWEVER POSTPONE THE ONSET OF THE
PRECIPITATION ACROSS THE FAR WEST UNTIL AFTER 00Z.
AS THE PRECIPITATION ENDS FROM WEST TO EAST THE SKIES ARE
EXPECTED TO CLEAR AS SUBSIDENCE DEVELOPS BEHIND THE UPPER LEVEL
TROUGH. BASED ON THE 18Z FRIDAY AND 00Z SATURDAY 925-950M
TEMPERATURES AND CLEARING SKIES WILL CONTINUE TO FAVOR HIGHS IN
THE MID 60S ACROSS MUCH OF WESTERN KANSAS. FURTHER EAST UPPER 50S
TO LOWER 60S APPEAR MORE REASONABLE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 245 PM CDT THU APR 19 2012
"WARM AND DRY" CAN DESCRIBE MOST OF THE EXTENDED PERIOD. WE WILL
SEE MODERATING TEMPERATURES OVER THE WEEKEND AS SURFACE LEE
TROUGHING STRENGTHENS. THE MAIN HEAT STORY BEGINS TUESDAY AND
CONTINUES THROUGH THE REST OF THE EXTENDED PERIOD AS 500 HPA
GEOPOTENTIAL HEIGHTS INCREASE IN RESPONSE TO AN AMPLIFIED RIDGE
BUILDING OVER THE ROCKIES. 850 HPA TEMPERATURES START AROUND 26-28
DEG C TUESDAY AND PEAK AROUND 28-30 DEG C BY THE END OF NEXT WEEK.
THIS SUPPORTS MIX DOWN TEMPERATURES WELL INTO THE 80S DEG F AND
MOST LIKELY SOME LOCATIONS WILL SEE >90 DEG F TEMPS. OVERNIGHT LOWS
THROUGH THE EXTENDED PERIOD WILL BE MILD AS MODERATE DEWPOINTS AND
SOUTHERLY WINDS CONTINUE. WILL KEEP SILENT POPS IN AS ANY UPPER LEVEL
FORCING REMAINS TO BE UNSEEN AND WEAK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 620 PM CDT THU APR 19 2012
MOSTLY CLOUDY SKIES ARE ANTICIPATED OVERNIGHT AS MID LEVEL
MOISTURE POOLS BEHIND A COLD FRONT DRAPED ACROSS OKLAHOMA AND THE
TEXAS PANHANDLE. MOSTLY CLOUDY SKIES AOA045 ARE FORECASTED BY
MIDNIGHT WITH A CHANCE OF LIGHT RAIN SHOWERS BEFORE SUNRISE
TOMORROW. WINDS WILL GENERALLY BE FROM THE NORTH AROUND 12 KNOTS
GUSTING TO OVER 15 KNOTS AT TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 44 61 39 76 / 20 20 0 0
GCK 43 62 40 77 / 20 10 0 0
EHA 45 66 41 79 / 30 10 0 0
LBL 45 65 40 78 / 30 10 0 0
HYS 41 60 38 76 / 20 10 0 0
P28 46 62 41 75 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RUSSELL
SHORT TERM...BURGERT
LONG TERM...SUGDEN
AVIATION...HOVORKA 42
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
829 AM EDT FRI APR 20 2012
.SYNOPSIS...
QUIET AND WARM CONDITIONS WILL CONTINUE TODAY. A SLOW MOVING COLD
FRONT WILL PROVIDE THE RISK FOR SHOWERS AND EVEN A FEW
THUNDERSTORMS TONIGHT AND SATURDAY. MUCH COOLER AIR WILL SETTLE IN
BEHIND THE FRONT ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SMALL UPDATES MADE TO CUT BACK CLOUD COVER EXPECTATIONS THIS
AFTERNOON. THE FIRST FEW FRAMES OF VISIBLE SATELLITE IMAGERY
INDICATE THE HIGH CLOUD COVERAGE IS NOT QUITE AS EXPANSIVE AS
WOULD BE SUGGESTED BY NWP. ADDITIONALLY...WITH CLEARER SKIES...850
MB TEMPERATURES SURGING ROUGHLY 2C FROM YESTERDAY...AND BETTER
MIXING LIKELY TODAY RELATIVE TO YESTERDAY...TEMPERATURES LOOK TO
BE AT LEAST 4F HIGHER TODAY THAN YESTERDAY. AS A
RESULT...TEMPERATURE EXPECTATIONS WERE ADJUSTED UPWARD A BIT FOR
THIS AFTERNOON. FRIES
PREVIOUS DISCUSSION...
SLOW MOVING ANA-FRONT WILL MOVE ACROSS THE MIDWEST THIS MORNING
AND INTO WESTERN OHIO BY LATE AFTERNOON. RELATIVELY DRY AIR WILL
REMAIN IN PLACE OVER THE UPPER OHIO VALLEY TODAY, SO EXPECT DRY
CONDITIONS AND DECENT AMOUNT OF SUNSHINE, DESPITE INCREASING HIGH
CLOUDS.
MADE SMALL ADJUSTMENTS TO THE COVERAGE OF THE INCREASING CLOUDS
PER RECENT SATELLITE DATA AND RUC MODEL OUTPUT. MADE SMALL
EXPECT HIGH TEMPERATURES THIS AFTERNOON TO BE MORE THAN 10 DEGREES
WARMER THAN NORMAL PER RECENT GFS AND NAM MOS AND HRRR MODEL
OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
FRONT WILL REACH THE WESTERN EDGE OF THE CWA THIS EVENING. SHOWERS
ASSOCIATED WITH THE BOUNDARY, ARE POSITIONED BEHIND THE FRONT WITH
THE MAIN UL SHORTWAVE. MODELS IN DECENT AGREEMENT SHOWING THE
FRONT LOSING SOME OF ITS BUNCH AS IT BEGINS TO ENCOUNTER THE DRIER
AND MORE STABLE AIR OVER THE UPPER OHIO VALLEY. CONFIDENCE IS LOW
ON HOW MUCH CONVECTION TO EXPECT LATER TODAY. THE LL DO DESTABILIZE
THIS AFTERNOON RIGHT AHEAD OF THE FRONT AS HIGHER SFC TDS SURGE
NORTHWARD. CURRENT FORECAST SOUNDINGS ARE INDICATING CONVECTIVE
TEMPS IN THE LOWER 80S, WHICH MAY BE JUST A BIT TOO HIGH, BUT IT
WILL BE CLOSE. ALL OF THE UL SUPPORT IS BEHIND THE FRONT AND THE
DEEP LAYERED MOISTURE IS BEHIND THE BOUNDARY AS WELL. FOR NOW WILL
LEAVE IN A MENTION FOR THE CHANCE FOR STORMS THIS EVENING, BUT
WILL REMOVE MENTION BY LATE EVENING AND EARLY SAT MORNING.
EXPECT AN AREA OF WIDESPREAD SHOWERS TO SLOWLY MOVE THROUGH LATE
TONIGHT, WITH EASTERN EDGES OF THE FORECAST AREA NOT SEEING MUCH
ACTIVITY UNTIL CLOSE TO DAWN.
SHOWER ACTIVITY WILL DIMINISH OVER THE WESTERN HALF OF THE AREA BY
LATE SAT MORNING, BUT WILL NOT EXIT THE EAST UNTIL THE EVENING.
DRAMATIC COOLING LOOKS SET FOR SATURDAY AS THE FRONT SLIDES EAST
OF THE AREA AND 850 MB TEMPERATURES DIVE FROM NEAR +10C IN THE
MORNING TO ABOUT +2C BY EVENING. WITH THIS KIND OF ADVECTION AT
850 MB...IT STANDS TO REASON THAT SURFACE PRESSURE GRADIENTS WILL
FAVOR STRONG/GUSTY NORTHWEST WINDS ON SATURDAY. THESE WINDS WILL
WEAKEN INTO SATURDAY NIGHT AND SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
VERY LOW CONFIDENCE FOR THE LONG TERM, AS MODEL SOLUTIONS ARE
BEGINNING TO GREATLY DIFFER. LATEST NAM/SREF/GEMS/CMC ARE SHOWING
AN EAST COAST LOW DEVELOPING EARLY NEXT WEEK, BUT REMAINING FAR
ENOUGH EAST TO HAVE LITTLE EFFECT ON THE AREA. HOWEVER THE OP
GFS/OP ECMWF ARE PROVIDING A MUCH DIFFERENT STORY DEVELOPING A
STRONG SFC LOW OFF THE CAROLINAS SUNDAY AFTERNOON AND THEN MOVING
IT NORTHWARD AND EVENTUALLY NORTHWESTWARD. AT THE SAME TIME, THE
LOW RAPIDLY DEEPENS. THIS WOULD MEAN A MUCH DIFFERENT FORECAST FOR
EARLY NEXT WEEK WITH RAIN, WINDY CONDITIONS, AND COLD TEMPS. HAVE
DECIDED TO MAKE LITTLE CHANGES TO THE LONG TERM, AS IT IS CLOSER
TO ENSEMBLE FORECAST AND FEEL FOR NOW THIS WOULD BE THE BEST WAY
TO GO.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
RECENT SURFACE AND SATELLITE DATA, COUPLED WITH SREF MODEL OUTPUT,
SHOW VFR CONTINUING ACROSS THE UPPER OHIO VALLEY INTO 06Z SATURDAY,
WITH LITTLE MORE SCATTERED DAYTIME CUMULUS AND BANDS OF ALTOCUMULUS
AND CIRRUS. SREF MODEL OUTPUT THEN SHOWS A COLD ANAFRONTAL BAND OF
MVFR RAIN SHOWERS MOVING EASTBOUND THROUGH THE AREA.
SURFACE WINDS WILL BE FROM THE SOUTH, WITH DAYTIME VERTICAL MIXING
CAUSING GUSTS TO 20 KTS THIS AFTERNOON.
OUTLOOK...SATURDAY THROUGH TUESDAY...
RESTRICTIONS LIKELY SATURDAY DUE TO LINGERING POSTFRONTAL SHOWERS
SATURDAY MORNING AND COLD POOL CLOUDINESS SATURDAY AFTERNOON AND
NIGHT. EXPECT TREND TOWARD VFR SUNDAY INTO TUESDAY, DESPITE
POSSIBLE LINGERING OF COLD POOL CLOUDINESS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
630 AM EDT FRI APR 20 2012
.SYNOPSIS...
QUIET AND WARM CONDITIONS WILL CONTINUE TODAY. A SLOW MOVING COLD
FRONT WILL PROVIDE THE RISK FOR SHOWERS AND EVEN A FEW
THUNDERSTORMS TONIGHT AND SATURDAY. MUCH COOLER AIR WILL SETTLE IN
BEHIND THE FRONT ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SLOW MOVING ANA-FRONT WILL MOVE ACROSS THE MIDWEST THIS MORNING
AND INTO WESTERN OHIO BY LATE AFTERNOON. RELATIVELY DRY AIR WILL
REMAIN IN PLACE OVER THE UPPER OHIO VALLEY TODAY, SO EXPECT DRY
CONDITIONS AND DECENT AMOUNT OF SUNSHINE, DESPITE INCREASING HIGH
CLOUDS.
MADE SMALL ADJUSTMENTS TO THE COVERAGE OF THE INCREASING CLOUDS
PER RECENT SATELLITE DATA AND RUC MODEL OUTPUT. MADE SMALL
EXPECT HIGH TEMPERATURES THIS AFTERNOON TO BE MORE THAN 10 DEGREES
WARMER THAN NORMAL PER RECENT GFS AND NAM MOS AND HRRR MODEL
OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
FRONT WILL REACH THE WESTERN EDGE OF THE CWA THIS EVENING. SHOWERS
ASSOCIATED WITH THE BOUNDARY, ARE POSITIONED BEHIND THE FRONT WITH
THE MAIN UL SHORTWAVE. MODELS IN DECENT AGREEMENT SHOWING THE
FRONT LOSING SOME OF ITS BUNCH AS IT BEGINS TO ENCOUNTER THE DRIER
AND MORE STABLE AIR OVER THE UPPER OHIO VALLEY. CONFIDENCE IS LOW
ON HOW MUCH CONVECTION TO EXPECT LATER TODAY. THE LL DO DESTABILIZE
THIS AFTERNOON RIGHT AHEAD OF THE FRONT AS HIGHER SFC TDS SURGE
NORTHWARD. CURRENT FORECAST SOUNDINGS ARE INDICATING CONVECTIVE
TEMPS IN THE LOWER 80S, WHICH MAY BE JUST A BIT TOO HIGH, BUT IT
WILL BE CLOSE. ALL OF THE UL SUPPORT IS BEHIND THE FRONT AND THE
DEEP LAYERED MOISTURE IS BEHIND THE BOUNDARY AS WELL. FOR NOW WILL
LEAVE IN A MENTION FOR THE CHANCE FOR STORMS THIS EVENING, BUT
WILL REMOVE MENTION BY LATE EVENING AND EARLY SAT MORNING.
EXPECT AN AREA OF WIDESPREAD SHOWERS TO SLOWLY MOVE THROUGH LATE
TONIGHT, WITH EASTERN EDGES OF THE FORECAST AREA NOT SEEING MUCH
ACTIVITY UNTIL CLOSE TO DAWN.
SHOWER ACTIVITY WILL DIMINISH OVER THE WESTERN HALF OF THE AREA BY
LATE SAT MORNING, BUT WILL NOT EXIT THE EAST UNTIL THE EVENING.
DRAMATIC COOLING LOOKS SET FOR SATURDAY AS THE FRONT SLIDES EAST
OF THE AREA AND 850 MB TEMPERATURES DIVE FROM NEAR +10C IN THE
MORNING TO ABOUT +2C BY EVENING. WITH THIS KIND OF ADVECTION AT
850 MB...IT STANDS TO REASON THAT SURFACE PRESSURE GRADIENTS WILL
FAVOR STRONG/GUSTY NORTHWEST WINDS ON SATURDAY. THESE WINDS WILL
WEAKEN INTO SATURDAY NIGHT AND SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
VERY LOW CONFIDENCE FOR THE LONG TERM, AS MODEL SOLUTIONS ARE
BEGINNING TO GREATLY DIFFER. LATEST NAM/SREF/GEMS/CMC ARE SHOWING
AN EAST COAST LOW DEVELOPING EARLY NEXT WEEK, BUT REMAINING FAR
ENOUGH EAST TO HAVE LITTLE EFFECT ON THE AREA. HOWEVER THE OP
GFS/OP ECMWF ARE PROVIDING A MUCH DIFFERENT STORY DEVELOPING A
STRONG SFC LOW OFF THE CAROLINAS SUNDAY AFTERNOON AND THEN MOVING
IT NORTHWARD AND EVENTUALLY NORTHWESTWARD. AT THE SAME TIME, THE
LOW RAPIDLY DEEPENS. THIS WOULD MEAN A MUCH DIFFERENT FORECAST FOR
EARLY NEXT WEEK WITH RAIN, WINDY CONDITIONS, AND COLD TEMPS. HAVE
DECIDED TO MAKE LITTLE CHANGES TO THE LONG TERM, AS IT IS CLOSER
TO ENSEMBLE FORECAST AND FEEL FOR NOW THIS WOULD BE THE BEST WAY
TO GO.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
RECENT SURFACE AND SATELLITE DATA, COUPLED WITH SREF MODEL OUTPUT,
SHOW VFR CONTINUING ACROSS THE UPPER OHIO VALLEY INTO 06Z SATURDAY,
WITH LITTLE MORE SCATTERED DAYTIME CUMULUS AND BANDS OF ALTOCUMULUS
AND CIRRUS. SREF MODEL OUTPUT THEN SHOWS A COLD ANAFRONTAL BAND OF
MVFR RAIN SHOWERS MOVING EASTBOUND THROUGH THE AREA.
SURFACE WINDS WILL BE FROM THE SOUTH, WITH DAYTIME VERTICAL MIXING
CAUSING GUSTS TO 20 KTS THIS AFTERNOON.
OUTLOOK...SATURDAY THROUGH TUESDAY...
RESTRICTIONS LIKELY SATURDAY DUE TO LINGERING POSTFRONTAL SHOWERS
SATURDAY MORNING AND COLD POOL CLOUDINESS SATURDAY AFTERNOON AND
NIGHT. EXPECT TREND TOWARD VFR SUNDAY INTO TUESDAY, DESPITE
POSSIBLE LINGERING OF COLD POOL CLOUDINESS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
210 PM EDT FRI APR 20 2012
.UPDATE...
ISSUED AT 1047 AM EDT FRI APR 20 2012
FCST IN FINE SHAPE. EXPECT TREND TOWARD IMPROVING WEATHER THROUGH
REST OF THE DAY. RADAR AND SFC OBS/WEB CAMS INDICATE BACK EDGE OF
PRECIPITATION FM NEAR ERY THROUGH ISQ AND ACROSS NORTHERN LK MICHIGAN
INTO DOOR COUNTY WISCONSIN. WV/RUC ANALYSIS SHOWS STRONGEST SHORTWAVE
OVR EASTERN CWA BUT ANOTHER WEAKER WAVE IS LIFTING OUT OF WI AS WELL.
BASED ON SHARPENING OF RADAR ECHOES LAST HR APPEARS THIS WAVE MAY BE
ENHANCING MID-LEVEL DEFORMATION OVR THE EASTERN CWA. RUC PICKS UP ON
THIS H7-H5 DEFORMATION AND SHOWS IT COLLAPSING 18Z-21Z AS SHORTWAVE
TROUGH MOVES EAST.
WEB CAMS SHOW MAINLY WET CONDITIONS OVR THE EAST THOUGH SOME SNOW
MAY BE MIXING IN AT TIMES WITH SFC TEMPS IN THE MIDDLE 30S. ANY SNOW
ACCUMS WILL BE MINIMAL REST OF THE MORNING. BY EARLY AFTN...PRECIP
IS EXPECTED TO BE MAINLY GONE AND SKIES SHOULD CLEAR OUT IN THE
CNTRL AND EAST. NORTHEAST WINDS PROVIDING UPSLOPE HELP AND IS HOLDING
IN POCKET OF LOWER CLOUDS OVR CNTRL CWA /SAW REPORTING OVC005 AT 14Z/
BUT ALL CLOUDS SHOULD FADE AWAY THROUGH AFTN AS LARGER SCALE FORCING
DEPARTS THE AREA. UPDATED/PUBLISHED GRIDS AND TEXT PRODUCTS ARE OUT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 543 AM EDT FRI APR 20 2012
WATER VAPOR LOOP SHOWS SHORTWAVE MOVING THROUGH WI WITH COUPLED UPR
JET STRUCTURE AND ASSOC FRONTOGENETIC FORCING SUPPORTING BAND OF
PCPN FROM NE WI INTO SCNTRL UPR MI AND NRN LOWER MI. REPORTS THUS
FAR FROM THIS PCPN BAND OVER NCNTRL/NE WI INTO MENOMINEE COUNTY
INDICATE A MIX OF RAIN AND SNOW. MOST SNOW ACCUMULATION APPEARS TO
BE LIGHT...LESS THAN AN INCH...ALTHOUGH THERE WAS A PUBLIC REPORT OF
2 INCHES IN DAGGETT...MAINLY IN GRASSY AREAS.
TODAY...GIVEN THE LACK OF ANY SIGNIFICANT SNOW ACCUMULATION REPORTS
AND THE FACT THAT PCPN UPSTREAM OVER WI APPEARS TO BE TAPERING OFF
AS NOTED ON RADAR LOOP...HAVE DECIDED TO DROP THE WINTER WX ADVISORY
FOR MENOMINEE COUNTY. MODELS SHOW UPR JET SUPPORT AND ASSOC FGEN
FORCING FALLING APART THROUGH THE MORNING HRS AS THE SYSTEM MOVES
EAST. ANY ADDITIONAL SNOW ACCUMULATION FROM THE SYSTEM OVER SCNTRL
AND ERN PORTIONS OF THE CWA WILL BE LESS THAN AN INCH BEFORE THE
PCPN ENDS LATER THIS MORNING.
THE REST OF THE CWA WILL BE QUIET AS SFC RDG BUILDS IN FROM THE WEST
IN THE WAKE OF THE LOW PRESSURE SYSTEM. MODEL SNDGS INDICATE Q-VECT
DIV SPREADING IN FROM THE WEST WITH ASSOC SHARP SUBSIDENCE/DRYING
WHICH SHOULD LEAD TO SUNSHINE FOR THE MAJORITY OF THE CWA BY LATE
MORNING/EARLY AFTN. DESPITE INCREASING SUNSHINE...LOOK FOR
TEMPERATURES TO ONLY RISE INTO THE LOWER TO MID 40S AS WE WILL BE
COLD ADVECTING IN A 10-20 KT N-NE FLOW.
TONIGHT INTO SATURDAY...HIGH PRESSURE BUILDING INTO NORTHERN ONTARIO
AND THE WESTERN GREAT LAKES WILL RESULT IN DRY BUT CONTINUED COOL
WEATHER. EXPECT IDEAL RADIATIONAL COOLING CONDITIONS TONIGHT OVER
WRN INTERIOR LOCATIONS AS THE SFC RDG AXIS MOVES OVER THE AREA AND
PCPN WATER VALUES FALL BLO .25 INCH. EXPECT LOWS RANGING FROM THE
LOWER 20S WRN INTERIOR TO THE UPR 20S/LOWER 30S EAST AND NEAR THE
GREAT LAKES. 850MB TEMPERATURES FALLING TO AROUND -6C ON SATURDAY IN
A WEAK N-NE FLOW WILL RESULT IN HIGH TEMPS ONLY IN THE 40S FOR MOST
AREAS...EXCEPT POSSIBLY APPROACHING 50F IN A FEW LOCATONS ALONG THE
WI BDR.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 543 AM EDT FRI APR 20 2012
HIGH PRESSURE WILL BE THE RULE AT THE SFC /AT LEAST MOST OF THIS
LONG RANGE/. HOWEVER...THE 500MB PATTERN WILL NOT ALLOW US A
COMPLETELY QUIET END TO OUR WEEKEND AND WEEK AHEAD WITH DOMINANT NW
FLOW ALOFT. THE 500MB OPEN WAVE/TROUGH WILL NOT MOVE FAR BY 00Z
SUNDAY...FROM W LAKE SUPERIOR THROUGH TX EARLY THIS MORNING...TO
LAKE HURON AND THE EASTERN GULF OF MEXICO. WHILE A COUPLE OF SMALLER
DISTURBANCES WILL SLIDE IN FROM THE WEST...KEEPING THE TROUGH
NEARBY...THE MAIN FEATURE OF INTEREST WILL BE WELL TO OUR SOUTH.
WILL DISMISS THE NAM SOLUTION FOR MUCH OF THIS FORECAST PERIOD....AS
IT LOOKS TO BE ON ITS OWN...PARTICULARLY AS WE MOVE INTO SATURDAY
NIGHT AND SUNDAY. THIS IS MAINLY DUE TO THE HANDLING OF THE A 500MB
WAVE EJECTING OUR WAY FROM THE LOW CURRENTLY SET UP OVER THE GULF OF
AK. THE NAM ATTEMPTS TO WRAP IT UP OVER THE CWA SUNDAY AFTERNOON
INSTEAD OF OVER THE CENTRAL APPALACHIANS/TN VALLEY AROUND THE SAME
TIME...LIKE THE CANADIAN/GFS/ECMWF. WIND WISE ON SUNDAY THE NAM IS
ROUGHLY 10KTS STRONGER THAN THE GFS FROM THE SFC UP THROUGH AT LEAST
500MB. THE 20/06Z RUN OF THE NAM EVEN ATTEMPTS TO SPIT OUT 0.25IN
RAIN WITH THIS FEATURE...WITH LITTLE MORE THAN A FEW ADDITIONAL
CLOUDS OFF THE REMAINING MODELS. WHILE THE LATEST 20/00Z LOOKS TO
PLAY UP THE MIDDLE GROUND BETWEEN THE QUICKER GFS AND NAM.
RH VALUES MAY BE TOO HIGH FOR SUNDAY...GIVEN THE MIXED DEWPOINT
VALUES IN THE TEENS EAST. LAKE BREEZES WILL BE THE MAIN CONCERN FIRE
WISE...IN THE LOW RH AREAS. STILL...WITH SLIGHTLY BELOW NORMAL
TEMPERATURES AND OVERALL LIGHT WINDS OVERALL WILL NOT HIGHLIGHT FIRE
WEATHER TOO MUCH.
WILL NOT GET INTO TOO MANY DETAILS OF THE LATTER PART OF THIS
FORECAST...WITH THE RETROGRADING STACKED SFC/500MB LOW SLIDING UP
THE EASTERN SEABOARD SUNDAY AND MONDAY...BEFORE SHIFTING ACROSS THE
LOWER GREAT LAKES AND WESTERN QUEBEC MONDAY AFTERNOON THROUGH MONDAY
NIGHT. AT THIS POINT...MUCH OF THE PRECIP AND EVEN CLOUD COVER LOOK
TO STAY TO OUR EAST. WE CAN STILL EXPECT SOME INCREASED COOL N/NNW
WINDS OFF LAKE SUPERIOR MONDAY AFTERNOON THROUGH AT LEAST TUESDAY
OVER THE EAST HALF OF THE CWA. EVEN WITH THIS FEATURE NEARING...LOOK
FOR A SLOW BUT STEADY WARMUP FROM MONDAY THROUGH THURSDAY...WITH
HIGH TEMPS IN THE MID 50S TO NEAR 60F BY THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 207 PM EDT FRI APR 20 2012
NORTH TO NORTHEAST WINDS REMAIN GUSTY AT THE TERMINALS THIS AFTN BUT
WILL DIMINISH THIS EVENING AS HIGH PRESSURE BUILDS IN FROM ONTARIO.
LINGERING SUB 2KFT STRATOCU AT SAW BUT VISIBLE SATELLITE SHOWS SIGNS
THIS SHOULD DISSIPATE BY LATE AFTN. LARGE SWATH OF LOW CLOUDS
UPSTREAM NORTH OF LK SUPERIOR MAY COME INTO THE AREA TONIGHT. PUT A
LOWER MVFR CIG IN AT SAW WITH UPSLOPE NORTHEAST WINDS AND ADDED
MOISTURE OFF LK SUPERIOR. ONLY SCT MVFR SHOULD OCCUR AT CMX OR IWD.
POTENTIAL THAT CIGS MAY GO LOWER AT SAW AS WHILE UPSLOPE MOISTENING
OCCURS...THERE COULD BE RADIATIONAL COOLING AS WELL /FAVORING
BUILDING DOWN OF CIGS/. LOW RISK ATTM...SO JUST WENT WITH CIGS OF
1KFT. LOWER CIGS SHOULD SCT OUT BY MID MORNING SATURDAY. SCT-BKN
MID CLOUDS WILL PUSH INTO CMX AND IWD THROUGH THE MORNING THOUGH.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 543 AM EDT FRI APR 20 2012
WINDS LESS THAN 30KTS WILL DOMINATE THE FORECAST PERIOD. AN EXITING
LOW TEMPORARILY ACROSS S LOWER LAKE MICHIGAN WILL PUSH ACROSS THE
LOWER GREAT LAKES THIS EVENING...MAKING WAY FOR A RIDGE TO BUILD
ACROSS THE UPPER GREAT LAKES FROM CANADA. EXPECT A STRONG LOW TO
PUSH NORTHWARD ACROSS THE EASTERN SEABOARD...MAKING ITS WAY NEAR
LAKE ONTARIO MONDAY AFTERNOON. THE RIDGE OVERHEAD WILL SLOWLY WEAKEN
AS A RESULT...AND SLOWLY BE REPLACED BY A TROUGH INVADING FROM THE
EAST MONDAY NIGHT INTO TUESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...JLA
MARINE...KF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
139 PM EDT FRI APR 20 2012
.SYNOPSIS...
ISSUED AT 400 AM EDT FRI APR 20 2012
LOW PRESSURE WILL MOVE ACROSS SOUTHERN LOWER MICHIGAN TODAY BRINGING
RAIN SHOWERS. A DRY AND COOLER WEEKEND IS EXPECTED WITH HIGHS IN THE
50S. TEMPERATURES WILL UNDERGO A SLIGHT MODERATING TREND TOWARD THE
MIDDLE PORTION OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1210 PM EDT FRI APR 20 2012
HAVE UPDATED FORECASTS TO REFINE TIMING OF PRECIPITATION EXITING
THE AREA THIS AFTERNOON AND EVENING. ALSO LOWERED HIGH
TEMPERATURES.
RADAR CURRENTLY SHOWS A SHARP BACK EDGE TO THE AREA OF
PRECIPITATION CREEPING SOUTHEAST THROUGH THE AREA. HRRR MODEL
GUIDANCE SUGGESTS THAT SOME SMALL AREAS OF RAIN COULD RE-DEVELOP
BEHIND THIS EDGE...WHICH MAKES SENSE GIVEN A WEAK POT VORT MAX
LIFTING NE TOWARDS THE CWFA AT THIS TIME. CLOUDS STILL ARE
EXPECTED TO ERODE FROM NW TO SE EARLY TONIGHT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON)
ISSUED AT 400 AM EDT FRI APR 20 2012
LOW PRESSURE WILL TRACK ENE FROM NEAR BEH AT 12Z THIS MORNING TO
NEAR TORONTO BY THIS EVENING BRINGING SHOWERS TO OUR FCST AREA
TODAY. CANNOT COMPLETELY RULE OUT AN ISOLATED RUMBLE OF THUNDER
LATER TODAY BUT GIVEN LACK OF INSTABILITY THE THREAT OF STORMS TODAY
IS QUITE LOW. SHOWERS WILL GRADUALLY TAPER OFF BY MID TO LATE AFTN
AND SOME WET SNOW FLAKES MAY TRY TO MIX IN ACROSS CENTRAL LOWER MI
THIS AFTERNOON AND EVENING BEFORE PRECIPITATION ENDS.
NORTHERLY FLOW CAA TONIGHT WITH GRADUAL CLEARING MAY POTENTIALLY SET
THE STAGE FOR SOME PATCHY FROST ACROSS PORTIONS OF OUR FCST AREA
DURING THE EARLY MORNING HOURS SATURDAY. LOW TEMPS MAY DIP INTO
THE UPPER 20S ACROSS OUR NORTHERN FCST AREA DURING THE EARLY MORNING
HOURS SATURDAY ON PURE CAA/CLEARING SKIES LATE. HOWEVER THE
WINDS/DECENT BOUNDARY LAYER MIXING SHOULD MITIGATE FROST POTENTIAL.
PARTLY SUNNY AND COOL CONDITIONS ON TAP FOR SATURDAY WITH MAX TEMPS
REACHING THE LOW TO MID 50S AFTER A COOL START TO THE DAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 400 AM EDT FRI APR 20 2012
UPPER TROUGH AXIS DEEPENS ACROSS THE GREAT LAKES OVER THE WEEKEND
BUT FAIR WEATHER EXPECTED UNDER SFC RIDGING. TEMPS FALL BELOW
FREEZING ONCE AGAIN SATURDAY AND SUNDAY MORNINGS ACROSS MUCH LOWER
MICHIGAN.
THE DEEPENING TROUGH AXIS RESULTS IN AN EAST COAST CYCLONE AND
EVENTUAL CUT OFF LOW THAT RETROGRADES TOWARDS THE EASTERN GREAT
LAKES BY EARLY NEXT WEEK. FOR MUCH OF NEXT WEEK THE CENTRAL GREAT
LAKES WILL BE IN BETWEEN THIS LOW AND A BIG UPPER LOW MOVING INTO
THE WESTERN CONUS. KEPT LOW CHANCE POPS IN THE FORECAST FOR TUESDAY
FOR NOW BUT CONFIDENCE IS LOW...AS THE 00Z GFS AND EURO SHOW THE
WESTERN EDGE OF THE PRECIP SHIELD BARELY REACHING THE EASTERN
FORECAST AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 140 PM EDT FRI APR 20 2012
FEW CHANGES TO PREVIOUS THINKING. IFR CIGS AND VSBYS ARE EXPECTED
BENEATH AND IMMEDIATELY BEHIND A NARROW BAND OF RAIN MOVING
SOUTHEAST THROUGH THE AREA. CIGS BEHIND THE BAND HAVE TRENDED
UPWARD OVERALL...BUT STILL EXPECT FUEL ALTERNATE CIGS BELOW 20KFT
TO PERSIST AT LEAST A FEW HOURS AFTER THE RAIN PASSES EACH
TERMINAL. STILL LOOKS LIKE RAPID CLEARING CAN BE EXPECTED ACROSS
THE AREA...MAINLY AFT 00Z.
&&
.MARINE...
ISSUED AT 1210 PM EDT FRI APR 20 2012
KEEPING GALE WARNING IN THE FORECAST. AREAS SOUTH OF MUSKEGON MAY
SEE SUSTAINED WINDS OF 20 TO 30 KNOTS...BUT FREQUENT GUSTS ABOVE
35 KNOTS WILL REMAIN POSSIBLE.
&&
.HYDROLOGY...
ISSUED AT 400 AM EDT FRI APR 20 2012
MORE SHOWERS ON THE WAY FOR LATER THIS MORNING INTO THE AFTERNOON
WITH QPF AMOUNTS UNDER A HALF AN INCH. THIS WILL NOT BE ENOUGH TO
RESULT IN ANY SIGNIFICANT HYDRO ISSUES WITH DRY WX ALSO ANTICIPATED
TONIGHT THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR LMZ844>849.
&&
$$
UPDATE...TJT
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...TJT
HYDROLOGY...LAURENS
MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1211 PM EDT FRI APR 20 2012
.SYNOPSIS...
ISSUED AT 400 AM EDT FRI APR 20 2012
LOW PRESSURE WILL MOVE ACROSS SOUTHERN LOWER MICHIGAN TODAY BRINGING
RAIN SHOWERS. A DRY AND COOLER WEEKEND IS EXPECTED WITH HIGHS IN THE
50S. TEMPERATURES WILL UNDERGO A SLIGHT MODERATING TREND TOWARD THE
MIDDLE PORTION OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1210 PM EDT FRI APR 20 2012
HAVE UPDATED FORECASTS TO REFINE TIMING OF PRECIPITATION EXITING
THE AREA THIS AFTERNOON AND EVENING. ALSO LOWERED HIGH
TEMPERATURES.
RADAR CURRENTLY SHOWS A SHARP BACK EDGE TO THE AREA OF
PRECIPITATION CREEPING SOUTHEAST THROUGH THE AREA. HRRR MODEL
GUIDANCE SUGGESTS THAT SOME SMALL AREAS OF RAIN COULD RE-DEVELOP
BEHIND THIS EDGE...WHICH MAKES SENSE GIVEN A WEAK POT VORT MAX
LIFTING NE TOWARDS THE CWFA AT THIS TIME. CLOUDS STILL ARE
EXPECTED TO ERODE FROM NW TO SE EARLY TONIGHT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY AFTERNOON)
ISSUED AT 400 AM EDT FRI APR 20 2012
LOW PRESSURE WILL TRACK ENE FROM NEAR BEH AT 12Z THIS MORNING TO
NEAR TORONTO BY THIS EVENING BRINGING SHOWERS TO OUR FCST AREA
TODAY. CANNOT COMPLETELY RULE OUT AN ISOLATED RUMBLE OF THUNDER
LATER TODAY BUT GIVEN LACK OF INSTABILITY THE THREAT OF STORMS TODAY
IS QUITE LOW. SHOWERS WILL GRADUALLY TAPER OFF BY MID TO LATE AFTN
AND SOME WET SNOW FLAKES MAY TRY TO MIX IN ACROSS CENTRAL LOWER MI
THIS AFTERNOON AND EVENING BEFORE PRECIPITATION ENDS.
NORTHERLY FLOW CAA TONIGHT WITH GRADUAL CLEARING MAY POTENTIALLY SET
THE STAGE FOR SOME PATCHY FROST ACROSS PORTIONS OF OUR FCST AREA
DURING THE EARLY MORNING HOURS SATURDAY. LOW TEMPS MAY DIP INTO
THE UPPER 20S ACROSS OUR NORTHERN FCST AREA DURING THE EARLY MORNING
HOURS SATURDAY ON PURE CAA/CLEARING SKIES LATE. HOWEVER THE
WINDS/DECENT BOUNDARY LAYER MIXING SHOULD MITIGATE FROST POTENTIAL.
PARTLY SUNNY AND COOL CONDITIONS ON TAP FOR SATURDAY WITH MAX TEMPS
REACHING THE LOW TO MID 50S AFTER A COOL START TO THE DAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 400 AM EDT FRI APR 20 2012
UPPER TROUGH AXIS DEEPENS ACROSS THE GREAT LAKES OVER THE WEEKEND
BUT FAIR WEATHER EXPECTED UNDER SFC RIDGING. TEMPS FALL BELOW
FREEZING ONCE AGAIN SATURDAY AND SUNDAY MORNINGS ACROSS MUCH LOWER
MICHIGAN.
THE DEEPENING TROUGH AXIS RESULTS IN AN EAST COAST CYCLONE AND
EVENTUAL CUT OFF LOW THAT RETROGRADES TOWARDS THE EASTERN GREAT
LAKES BY EARLY NEXT WEEK. FOR MUCH OF NEXT WEEK THE CENTRAL GREAT
LAKES WILL BE IN BETWEEN THIS LOW AND A BIG UPPER LOW MOVING INTO
THE WESTERN CONUS. KEPT LOW CHANCE POPS IN THE FORECAST FOR TUESDAY
FOR NOW BUT CONFIDENCE IS LOW...AS THE 00Z GFS AND EURO SHOW THE
WESTERN EDGE OF THE PRECIP SHIELD BARELY REACHING THE EASTERN
FORECAST AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 737 AM EDT FRI APR 20 2012
SOME MVFR CONDITIONS AND RAIN TODAY AS LOW PRESSURE MOVES THROUGH.
IFR IS POSSIBLE AT TIMES THIS AFTERNOON WITH CEILINGS BELOW 1000
FEET AGL. THE RAIN SHOULD MOVES EAST THIS AFTERNOON THEN NORTH
WINDS WILL GUST TO 20 KNOTS OR MORE THROUGH THE AFTERNOON. SOME
SLOW CLEARING SHOULD DEVELOP LATER TONIGHT AS THE LOW MOVES AWAY.
&&
.MARINE...
ISSUED AT 1210 PM EDT FRI APR 20 2012
KEEPING GALE WARNING IN THE FORECAST. AREAS SOUTH OF MUSKEGON MAY
SEE SUSTAINED WINDS OF 20 TO 30 KNOTS...BUT FREQUENT GUSTS ABOVE
35 KNOTS WILL REMAIN POSSIBLE.
&&
.HYDROLOGY...
ISSUED AT 400 AM EDT FRI APR 20 2012
MORE SHOWERS ON THE WAY FOR LATER THIS MORNING INTO THE AFTERNOON
WITH QPF AMOUNTS UNDER A HALF AN INCH. THIS WILL NOT BE ENOUGH TO
RESULT IN ANY SIGNIFICANT HYDRO ISSUES WITH DRY WX ALSO ANTICIPATED
TONIGHT THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING UNTIL 10 PM EDT THIS EVENING FOR LMZ844>849.
&&
$$
UPDATE...TJT
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...LAURENS
MARINE...TJT
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1049 AM EDT FRI APR 20 2012
.UPDATE...
ISSUED AT 1047 AM EDT FRI APR 20 2012
FCST IN FINE SHAPE. EXPECT TREND TOWARD IMPROVING WEATHER THROUGH
REST OF THE DAY. RADAR AND SFC OBS/WEB CAMS INDICATE BACK EDGE OF
PRECIPITATION FM NEAR ERY THROUGH ISQ AND ACROSS NORTHERN LK MICHIGAN
INTO DOOR COUNTY WISCONSIN. WV/RUC ANALYSIS SHOWS STRONGEST SHORTWAVE
OVR EASTERN CWA BUT ANOTHER WEAKER WAVE IS LIFTING OUT OF WI AS WELL.
BASED ON SHARPENING OF RADAR ECHOES LAST HR APPEARS THIS WAVE MAY BE
ENHANCING MID-LEVEL DEFORMATION OVR THE EASTERN CWA. RUC PICKS UP ON
THIS H7-H5 DEFORMATION AND SHOWS IT COLLAPSING 18Z-21Z AS SHORTWAVE
TROUGH MOVES EAST.
WEB CAMS SHOW MAINLY WET CONDITIONS OVR THE EAST THOUGH SOME SNOW
MAY BE MIXING IN AT TIMES WITH SFC TEMPS IN THE MIDDLE 30S. ANY SNOW
ACCUMS WILL BE MINIMAL REST OF THE MORNING. BY EARLY AFTN...PRECIP
IS EXPECTED TO BE MAINLY GONE AND SKIES SHOULD CLEAR OUT IN THE
CNTRL AND EAST. NORTHEAST WINDS PROVIDING UPSLOPE HELP AND IS HOLDING
IN POCKET OF LOWER CLOUDS OVR CNTRL CWA /SAW REPORTING OVC005 AT 14Z/
BUT ALL CLOUDS SHOULD FADE AWAY THROUGH AFTN AS LARGER SCALE FORCING
DEPARTS THE AREA. UPDATED/PUBLISHED GRIDS AND TEXT PRODUCTS ARE OUT.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 543 AM EDT FRI APR 20 2012
WATER VAPOR LOOP SHOWS SHORTWAVE MOVING THROUGH WI WITH COUPLED UPR
JET STRUCTURE AND ASSOC FRONTOGENETIC FORCING SUPPORTING BAND OF
PCPN FROM NE WI INTO SCNTRL UPR MI AND NRN LOWER MI. REPORTS THUS
FAR FROM THIS PCPN BAND OVER NCNTRL/NE WI INTO MENOMINEE COUNTY
INDICATE A MIX OF RAIN AND SNOW. MOST SNOW ACCUMULATION APPEARS TO
BE LIGHT...LESS THAN AN INCH...ALTHOUGH THERE WAS A PUBLIC REPORT OF
2 INCHES IN DAGGETT...MAINLY IN GRASSY AREAS.
TODAY...GIVEN THE LACK OF ANY SIGNIFICANT SNOW ACCUMULATION REPORTS
AND THE FACT THAT PCPN UPSTREAM OVER WI APPEARS TO BE TAPERING OFF
AS NOTED ON RADAR LOOP...HAVE DECIDED TO DROP THE WINTER WX ADVISORY
FOR MENOMINEE COUNTY. MODELS SHOW UPR JET SUPPORT AND ASSOC FGEN
FORCING FALLING APART THROUGH THE MORNING HRS AS THE SYSTEM MOVES
EAST. ANY ADDITIONAL SNOW ACCUMULATION FROM THE SYSTEM OVER SCNTRL
AND ERN PORTIONS OF THE CWA WILL BE LESS THAN AN INCH BEFORE THE
PCPN ENDS LATER THIS MORNING.
THE REST OF THE CWA WILL BE QUIET AS SFC RDG BUILDS IN FROM THE WEST
IN THE WAKE OF THE LOW PRESSURE SYSTEM. MODEL SNDGS INDICATE Q-VECT
DIV SPREADING IN FROM THE WEST WITH ASSOC SHARP SUBSIDENCE/DRYING
WHICH SHOULD LEAD TO SUNSHINE FOR THE MAJORITY OF THE CWA BY LATE
MORNING/EARLY AFTN. DESPITE INCREASING SUNSHINE...LOOK FOR
TEMPERATURES TO ONLY RISE INTO THE LOWER TO MID 40S AS WE WILL BE
COLD ADVECTING IN A 10-20 KT N-NE FLOW.
TONIGHT INTO SATURDAY...HIGH PRESSURE BUILDING INTO NORTHERN ONTARIO
AND THE WESTERN GREAT LAKES WILL RESULT IN DRY BUT CONTINUED COOL
WEATHER. EXPECT IDEAL RADIATIONAL COOLING CONDITIONS TONIGHT OVER
WRN INTERIOR LOCATIONS AS THE SFC RDG AXIS MOVES OVER THE AREA AND
PCPN WATER VALUES FALL BLO .25 INCH. EXPECT LOWS RANGING FROM THE
LOWER 20S WRN INTERIOR TO THE UPR 20S/LOWER 30S EAST AND NEAR THE
GREAT LAKES. 850MB TEMPERATURES FALLING TO AROUND -6C ON SATURDAY IN
A WEAK N-NE FLOW WILL RESULT IN HIGH TEMPS ONLY IN THE 40S FOR MOST
AREAS...EXCEPT POSSIBLY APPROACHING 50F IN A FEW LOCATONS ALONG THE
WI BDR.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 543 AM EDT FRI APR 20 2012
HIGH PRESSURE WILL BE THE RULE AT THE SFC /AT LEAST MOST OF THIS
LONG RANGE/. HOWEVER...THE 500MB PATTERN WILL NOT ALLOW US A
COMPLETELY QUIET END TO OUR WEEKEND AND WEEK AHEAD WITH DOMINANT NW
FLOW ALOFT. THE 500MB OPEN WAVE/TROUGH WILL NOT MOVE FAR BY 00Z
SUNDAY...FROM W LAKE SUPERIOR THROUGH TX EARLY THIS MORNING...TO
LAKE HURON AND THE EASTERN GULF OF MEXICO. WHILE A COUPLE OF SMALLER
DISTURBANCES WILL SLIDE IN FROM THE WEST...KEEPING THE TROUGH
NEARBY...THE MAIN FEATURE OF INTEREST WILL BE WELL TO OUR SOUTH.
WILL DISMISS THE NAM SOLUTION FOR MUCH OF THIS FORECAST PERIOD....AS
IT LOOKS TO BE ON ITS OWN...PARTICULARLY AS WE MOVE INTO SATURDAY
NIGHT AND SUNDAY. THIS IS MAINLY DUE TO THE HANDLING OF THE A 500MB
WAVE EJECTING OUR WAY FROM THE LOW CURRENTLY SET UP OVER THE GULF OF
AK. THE NAM ATTEMPTS TO WRAP IT UP OVER THE CWA SUNDAY AFTERNOON
INSTEAD OF OVER THE CENTRAL APPALACHIANS/TN VALLEY AROUND THE SAME
TIME...LIKE THE CANADIAN/GFS/ECMWF. WIND WISE ON SUNDAY THE NAM IS
ROUGHLY 10KTS STRONGER THAN THE GFS FROM THE SFC UP THROUGH AT LEAST
500MB. THE 20/06Z RUN OF THE NAM EVEN ATTEMPTS TO SPIT OUT 0.25IN
RAIN WITH THIS FEATURE...WITH LITTLE MORE THAN A FEW ADDITIONAL
CLOUDS OFF THE REMAINING MODELS. WHILE THE LATEST 20/00Z LOOKS TO
PLAY UP THE MIDDLE GROUND BETWEEN THE QUICKER GFS AND NAM.
RH VALUES MAY BE TOO HIGH FOR SUNDAY...GIVEN THE MIXED DEWPOINT
VALUES IN THE TEENS EAST. LAKE BREEZES WILL BE THE MAIN CONCERN FIRE
WISE...IN THE LOW RH AREAS. STILL...WITH SLIGHTLY BELOW NORMAL
TEMPERATURES AND OVERALL LIGHT WINDS OVERALL WILL NOT HIGHLIGHT FIRE
WEATHER TOO MUCH.
WILL NOT GET INTO TOO MANY DETAILS OF THE LATTER PART OF THIS
FORECAST...WITH THE RETROGRADING STACKED SFC/500MB LOW SLIDING UP
THE EASTERN SEABOARD SUNDAY AND MONDAY...BEFORE SHIFTING ACROSS THE
LOWER GREAT LAKES AND WESTERN QUEBEC MONDAY AFTERNOON THROUGH MONDAY
NIGHT. AT THIS POINT...MUCH OF THE PRECIP AND EVEN CLOUD COVER LOOK
TO STAY TO OUR EAST. WE CAN STILL EXPECT SOME INCREASED COOL N/NNW
WINDS OFF LAKE SUPERIOR MONDAY AFTERNOON THROUGH AT LEAST TUESDAY
OVER THE EAST HALF OF THE CWA. EVEN WITH THIS FEATURE NEARING...LOOK
FOR A SLOW BUT STEADY WARMUP FROM MONDAY THROUGH THURSDAY...WITH
HIGH TEMPS IN THE MID 50S TO NEAR 60F BY THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 543 AM EDT FRI APR 20 2012
MAIN CONCERN OF THE FORECAST PERIOD WILL FOCUS ON TIMING OF LOW
CLOUD DECK LIFTING AT KSAW WHICH SHOULD OCCUR BY EARLY AFTERNOON.
PCPN SHOULD GENERALLY STAY SOUTH AND EAST OF KSAW SO DID NOT MENTION
ANYTHING IN TAF. EXPECT VFR CONDITIONS AT KIWD AND KCMX THROUGH THE
PERIOD UNDER INFLUENCE OF SFC RDG BUILDING IN FM THE WEST. NORTH TO
NORTHEAST WINDS COULD GET A BIT GUSTY (AOA 20 KT AT TIMES) BY LATE
MORNING/AFTERNOON...ESPECIALLY AT KSAW...WITH TIGHT PRES GRAD BTWN
DEPARTING LOW AND BUILDING HIGH FROM THE WEST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 543 AM EDT FRI APR 20 2012
WINDS LESS THAN 30KTS WILL DOMINATE THE FORECAST PERIOD. AN EXITING
LOW TEMPORARILY ACROSS S LOWER LAKE MICHIGAN WILL PUSH ACROSS THE
LOWER GREAT LAKES THIS EVENING...MAKING WAY FOR A RIDGE TO BUILD
ACROSS THE UPPER GREAT LAKES FROM CANADA. EXPECT A STRONG LOW TO
PUSH NORTHWARD ACROSS THE EASTERN SEABOARD...MAKING ITS WAY NEAR
LAKE ONTARIO MONDAY AFTERNOON. THE RIDGE OVERHEAD WILL SLOWLY WEAKEN
AS A RESULT...AND SLOWLY BE REPLACED BY A TROUGH INVADING FROM THE
EAST MONDAY NIGHT INTO TUESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
201 AM EDT FRI APR 20 2012
.SYNOPSIS...
ISSUED AT 433 PM EDT THU APR 19 2012
A STORM SYSTEM ORGANIZING OVER THE PLAINS...WILL LIFT TOWARD THE
OHIO VALLEY TONIGHT...BEFORE EXITING EAST INTO LAKE ONTARIO FRIDAY.
RAIN WILL OVERSPREAD THE STATE THIS EVENING...IN ADVANCE OF THE
APPROACHING SYSTEM. THE RAIN WILL CHANGE TO SNOW ACROSS EAST UPPER
AND THE STRAITS REGION OVERNIGHT...AS COLDER AIR FILTERS INTO THE
NORTHERN GREAT LAKES. COLD AIR WILL CONTINUE TO PUSH ACROSS THE STATE
FRIDAY...GENERATING SNOW FOR MUCH OF NORTHERN MICHIGAN.
HIGH PRESSURE FROM THE UPPER MIDWEST AND CENTRAL CANADA...WILL BUILD
INTO THE GREAT LAKES FRIDAY NIGHT...ON THE BACKSIDE OF THE EXITING
OHIO VALLEY SYSTEM. HIGH PRESSURE WILL THEN LINGER OVER THE STATE
INTO THE BEGINNING OF THE UPCOMING WORK WEEK. THIS PATTERN WILL
GENERATE SOME SUN AND MILD TEMPERATURES THROUGH THE WEEKEND.
&&
.UPDATE...
ISSUED AT 140 AM EDT FRI APR 20 2012
ONGOING PRECIPITATION IS BEHAVING AS PLANNED...WITH STEADY AND
HEAVIEST RAINFALL OCCURRING WITHIN LOW TO MID LEVEL FGEN AND MAX
DEEP LAYER -DIVQ...FROM NRN LEELANAU COUNTY THROUGH CHARLEVOIX
AND NRN LAKE HURON. H8 WINDS ARE VEERING IN RESPONSE TO
APPROACHING LOW PRESSURE...THUS WAA IS CONTINUING ACROSS NRN LOWER
AND KEEPING ANY LIQUID FROM CHANGING TO SNOW. THE DOWNWARD BRANCH
OF THE FGEN CIRCULATION IS OBVIOUSLY AFFECTING EASTERN UPPER
MICHIGAN. CEILINGS WERE STILL ONLY 6KFT AT KINROSS AND 10KFT AT
SSM. MOST OF THE HEAVIER RAINFALL WILL CONTINUE THROUGH ROUGHLY
11Z-12Z WHEN THE STRONG FGEN SIGNAL WILL LIFT EAST OF US AND THE
LLJ BEGINS TO WEAKEN. THE SUBSEQUENTLY WEAKENED DOWNWARD BRANCH OF
THE FGEN CIRCULATION WILL LOOSEN IT`S GRIP ON EASTERN UPPER...AND
LIGHT PRECIPITATION WILL START TO FALL. THIS SHOULD BE MIXED WITH
SNOW...EARLY ON...BUT AS COLDER AIR THEN FILTERS IN BEHIND THE
DEPARTING H8 LOW...A CHANGEOVER TO SNOW WILL OCCUR FROM NW TO SE
THROUGH THE MORNING. SNOW AMOUNTS MAY NEED TO BE LOWERED A TOUCH
MORE...BUT THIS WILL HAVE TO BE BASED HEAVILY ON CHANGEOVER TIMES
BY WATCHING OBS/DUAL POL RADAR IMAGERY.
PRECIPITATION IS EXPECTED TO MAKE A SLIGHTLY QUICKER EXIT WITH
ONLY SOME CHANCE/SLIGHT CHANCE STUFF FOR THE GREATER PART OF THE
AFTERNOON.
UPDATE ISSUED AT 1023 PM EDT THU APR 19 2012
WILL GO AHEAD AND ADD EMMET...CHEBOYGAN...PRESQUE ISLE COUNTIES TO
THE ADVISORY WITH THIS ISSUANCE BASED ON RECENT OBSERVATIONAL
TRENDS...AS WELL AS NEW 00Z NAM...AS WELL AS OUR IN HOUSE LOCAL
WRF AND HRRR. DUAL POL DATA CONFIRMS THAT THE MELTING LAYER IS AT
ABOUT 3-4KFT AT APX...AND HAS DIPPED DOWN BELOW 2KFT AT TIMES.
OBSERVATIONS FROM ACROSS LAKE MICHIGAN ARE SHOWING RAIN CHANGING
TO SNOW AT WAUSAU...WITH TEMPERATURES FALLING QUICKLY UNDER
DEVELOPING BANDED PRECIPITATION IN FGEN/DEFORMATION BULLSEYE IN
THE H85-H7 LEVEL.
HRRR/LOCAL WRF ARE VERY AGGRESSIVE SHOWIGN COOLING OVER THE TIP OF
THE MITT AFTER 9Z...WITH SNOW REACHING AS FAR SOUTH AS GAYLORD BY
DAYBREAK IN THESE SOLUTIONS. NEW 00Z NAM TRENDED HEAVILY IN THIS
DIRECTION...AND WHILE I THINK THE COOLING RATES ARE A LITTLE
OVERDONE...I WILL TREND THE FORECAST SLIGHTLY COOLER...AND A
LITTLE SNOWIER BEFORE DAYBREAK. GIVEN THAT CONFIDENCE IS NOW
INCREASING THAT A CHANGEOVER TO SNOW WILL OCCUR TOWARDS DAYBREAK
/WITH AMPLE PRECIPITATION LIKELY AFTER THIS POINT/ FEEL THAT THE
EXPANDED ADVISORY IS WARRANTED.
HAVE ALSO BROUGHT A DECREASE IN POPS /TO SCT SHRAS/ TO SOUTHERN
AREAS FOR A TIME TONIGHT AS BACK EDGE TO INITIAL WARM ADVECTION
SURGE PUSHES EAST...WITH A BREAK BEFORE THE FGEN-BAND SAGS SOUTH
AND EAST WELL AFTER MIDNIGHT.
UPDATE ISSUED AT 652 PM EDT THU APR 19 2012
PRIMARY UPDATE AT THIS TIME IS TO REFINE LEADING EDGE OF PRECIP
FIELD THAT IS NOW ADVANCING NORTHEAST INTO THE CWA. SURFACE LOW
NOW OVER SOUTHEASTERN IOWA WITH IMPRESSIVE WARM ADVECTION PLUME AS
BAND OF ONE INCH PWATS SURGE NORTH OVER TIGHTENING FRONTAL BOUNDARY.
OTHER FIELDS NEED VERY LITTLE IN THE WAY OF UPDATING.
DUAL POL PRODUCTS SUGGESTING A MELTING LEVEL AROUND 4KFT AGL
ATTM...SOMEWHAT BELOW NEAR TERM GUIDANCE. STILL SAFELY STARING AS
RAIN...BUT WILL BE WATCHING THESE TRENDS /AND UPCOMING 00Z APX
RAOB/ FOR MORE CLUES TO THE LLEVEL THERMAL FIELDS AS LLEVEL
AGEOSTROPHIC NORTHERLIES SLOWLY COOL THE BOUNDARY LAYER.
AM A LITTLE CONCERNED GIVEN PLACEMENT OF RUC H85-H7 FGEN SIGNATURE
/WHICH RIGHT NOW IS LINING UP BETTER WITH PRECIP PLACEMENT THAN FN
CONVERGENCE/ ALONG WITH RECENT HRRR TRENDS THAT SUGGEST THAT THE
SOUTHERN EDGE OF THE PRECIPITATION SHIELD MAY ADVANCE A BIT
FURTHER NORTH THAN CURRENTLY INDICATED...ESPECIALLY AFTER
MIDNIGHT. WILL NOT MAKE CHANGES TO THIS PORTION OF THE FORECAST
JUST YET...BUT THIS WOULD MEAN SOME REDUCED RAINFALL TOTALS SE OF
A CAD-APN LINE IF THE TRENDS HOLD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY) ISSUED AT 433 PM EDT
THU APR 19 2012
EARLY AFTERNOON SURFACE ANALYSIS SHOWS 1005MB SURFACE WAVE OVER
NORTHEAST KANSAS...WARM/STATIONARY FRONT EXTENDS EAST ACROSS THE
SOUTHERN HALF OF IOWA/FAR NORTHERN ILLINOIS AND UP INTO SOUTHERN
LOWER MICHIGAN. LOW LEVEL ANTICYCLONIC FLOW ACROSS NORTHERN
MICHIGAN KEEPING WINDS OUT OF THE NORTH AND KEEPING TEMPERATURES
COOLER...PERSISTENT DIURNALLY ENHANCED STRATOCUMULUS DECK ACROSS
EASTERN UPPER ALSO HELPING KEEP TEMPERATURES IN THE LOWER-MID 40S.
BAROCLINIC ZONE COMBINED WITH WELL DEFINED VORTICITY CENTER HEADED
TOWARD THE NEBRASKA/IOWA BORDER IS SPREADING RAIN SHOWERS
EAST-NORTHEAST ACROSS IOWA/SOUTHERN MINNESOTA/SOUTHERN WISCONSIN...
WITH AN AXIS OF 1+ INCH PRECIPITABLE WATER VALUES POOLED ALONG THE
FRONT.
KANSAS SURFACE LOW FORECAST TO TRACK EAST-NORTHEAST AND INTO FAR
SOUTHWEST LOWER MICHIGAN BY FRIDAY MORNING...WITH ASSOCIATED
EAST-WEST BAROCLINIC ZONE ALSO NUDGING NORTHWARD WITH A TIGHT
THERMAL GRADIENT SETTING UP ACROSS LOWER MICHIGAN. LOOKING LIKE A
GOOD SETUP FOR A MODERATE-HEAVY PRECIPITATION EVENT...AS WARM
ADVECTION NORTH OF FRONTAL ZONE COMBINES WITH STRONGLY SLOPED
FRONTOGENETIC RESPONSE AND RIGHT ENTRANCE REGION DYNAMICS FROM
DEVELOPING JET STREAK TO THE NORTH AND NORTHEAST OF LAKE SUPERIOR.
CURRENT EXPECTATION IS THAT HEAVIEST QPF WILL SET UP ACROSS FAR
NORTHWEST LOWER MICHIGAN AND THE STRAITS REGION BASED ON LOCATION OF
STRONGEST FORCING...WILL LIKELY BE A TIGHT GRADIENT TO THE NORTH
GIVEN MID LEVEL DEFORMATION AND LOWER LAYER SUBSIDENCE IN DESCENDING
BRANCH OF FRONTOGENETIC CIRCULATION. PRECIPITATION AMOUNTS IN
EXCESS OF AN INCH APPEAR POSSIBLE WITHIN A MBL-TVC-PLN AXIS (WILL
CARRY A HEAVY RAIN MENTION IN THESE AREAS). RAINFALL IS MAKING
STEADY PROGRESS ACROSS WISCONSIN...AND WILL SPREAD INTO THE FORECAST
AREA FROM THE SOUTHWEST THIS EVENING. MAIN PROBLEM IS GOING TO BE
PRECIPITATION TYPE...AS "COLDEST" AIR BUMPS UP AGAINST NORTHERN QPF
GRADIENT ACROSS EASTERN UPPER. TEMPERATURES IN THE MID 40S/DEW
POINTS IN THE MID 30S WILL ENSURE PRECIPITATION STARTS AS RAIN FROM
THE STRAITS NORTHWARD...AFTER MIDNIGHT SOME LOW LEVEL COLD ADVECTION
FROM THE NORTHEAST AND COOLING DUE TO MELTING/EVAPORATION FORECAST
TO GRADUALLY ERODE AWAY SURFACE BASED WARM LAYER. NOT EXPECTING
SURFACE TEMPERATURES TO FALL BELOW FREEZING...BUT WARM LAYER MAY
SHRINK ENOUGH TO ALLOW PRECIP TO TRANSITION TOWARD SNOW ACROSS
EASTERN UPPER AND POSSIBLY INTO THE TIP OF THE MITT COUNTIES AS
WELL. SNOW AMOUNTS OVERNIGHT WILL ALL DEPEND ON HOW QUICKLY THIS
PROCESS OCCURS (IF IT OCCURS AT ALL...WHICH IS ALSO A POSSIBILITY).
ASSUMING A LATER TRANSITION WENT WITH UP TO 2 INCHES NORTH OF THE
BRIDGE BY DAYBREAK.
SURFACE WAVE FORECAST TO HEAD EAST FROM SOUTHERN LOWER MICHIGAN AND
INTO THE LOWER GREAT LAKES DURING THE DAY FRIDAY. UPWARD FORCING
WILL STILL BE PRETTY STRONG ACROSS NORTHERN LOWER MICHIGAN TO START
THE DAY...SHIFTING EAST DURING THE MORNING WHICH WILL PULL HEAVIER
PRECIPITATION EASTWARD WITH IT. THERMAL FIELDS ACROSS EASTERN UPPER
AND FAR NORTHERN LOWER WILL STILL BE MARGINAL WITH REGARD TO PRECIP
TYPE...ESPECIALLY ALONG M-32 CORRIDOR WHERE GUIDANCE OFFERING UP
DIFFERING IDEAS. WILL PLAY WITH THE IDEA OF ALL SNOW ACROSS EASTERN
UPPER AND ALONG THE M-68 CORRIDOR...WITH A WINTRY MIX OF RAIN/
SLEET/SNOW POSSIBLE ALONG THE M-32 CORRIDOR. SEVERAL INCHES OF SNOW
POSSIBLE ACROSS THE TIP OF THE MITT AND FAR SOUTHEAST UPPER
MICHIGAN...CURRENT FORECAST WILL HAVE A BAND OF 3-5 INCHES OF SNOW
ALONG/NORTH OF M-68...HIGHLY SUBJECT TO CHANGE AND WILL BE DEPENDENT
ON HOW THERMAL PROFILE EVOLVES. SINCE IT APPEARS THAT EASTERN UPPER
MICHIGAN WILL BE MOST LIKELY TO SEE MORE PERSISTENT SNOWFALL OUT OF
THIS EVENT...WILL GO AHEAD AND ISSUE A WINTER WEATHER ADVISORY FOR
CHIPPEWA/MACKINAC COUNTIES FOR LATE TONIGHT INTO FRIDAY MORNING. IF
COLDER AIR ARRIVES EARLY ENOUGH...HEADLINES WILL NEED TO BE EXPANDED
SOUTH INTO AT LEAST THE TIP OF THE MITT COUNTIES. BUT NOT CONFIDENT
ENOUGH ON TIMING YET...AND HAVE SOME TIME TO HOLD OFF SINCE GREATEST
THREAT FOR SNOWFALL ACROSS FAR NORTHERN LOWER WILL BE FRIDAY
MORNING.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY) ISSUED AT 433 PM EDT
THU APR 19 2012
CURRENT QUASI-ZONAL FLOW PATTERN OVER THE LOWER 48 ABOUT SET TO GO
THROUGH DEEP AMPLIFICATION...COURTESY OF RAPID UPPER JET
INTENSIFICATION TODAY OVER ONTARIO...WITH SECONDARY STRONG UPPER JET
STREAK CUTTING INTO THE PACIFIC NORTHWEST. COMBO OF THESE WILL CARVE
OUT A DEEP EASTERN TROUGH THIS WEEKEND INTO EARLY NEXT WEEK...ITSELF
BOOKENDED BY AMPLIFYING INTERMOUNTAIN WEST AND DAVIS STRAITS
RIDGING. SAID CONFIGURATION PLACES NORTHERN MICHIGAN IN SOMEWHAT
PROLONGED PERIOD OF MAINLY DRY AND SEASONABLY COOL NORTH TO EAST
FLOW THOUGH EARLY NEXT WEEK. FORECAST CONCERNS CENTER ON TEMPERATURE
TRENDS AND PERIODIC LOW END RAIN CHANCES AS WEAK MOISTURE STARVED
WAVES ADVANCE THROUGH BACKSIDE OF EASTERN TROUGH.
FIRST THINGS FIRST...AND MAY STILL BE DEALING WITH A FEW RAIN/SNOW
SHOWERS EARLY FRIDAY EVENING AS LAST VESTIGES OF TONIGHTS/FRIDAY
SYSTEM (SEE SHORT TERM DISCUSSION) EXIT STAGE RIGHT. INFILTRATION OF
NORTH FLOW DEEP LAYER DRYING AND SURFACE HIGH PRESSURE SHOULD BRING
A QUICK END TO ANY PRECIP...LEAVING OVERNIGHT FRIDAY RIGHT THROUGH
SATURDAY NIGHT DRY WITH GRADUALLY DECREASING CLOUD COVER. WHILE
INCREASING AMOUNTS OF SUNSHINE SATURDAY WILL PARTIALLY OFFSET
MAINTENANCE OF COOL NORTH WINDS...CLEAR SKIES AND QUICK DECOUPLING
OFF LOW LEVEL WINDS WILL ALLOW TEMPERATURES TO DROP RAPIDLY SATURDAY
EVENING. LAST FEW WEEKS HAVE SEEN PLENTY OF SIMILAR SCENARIOS...AND
EACH HAVE RESULTED IN COLDER READINGS THAN GUIDANCE INITIALLY
ANTICIPATED. EXPECT THIS TO BE THE CASE ONCE AGAIN...AND HAVE GONE
AHEAD A CUT LOWS BY SEVERAL DEGREES...WITH MOST INLAND AREAS DOWN
INTO THE 20S BY EARLY SUNDAY MORNING (IF CURRENT TRENDS CONTINUE...
COULD EVEN SEE THE NEED TO LOWER TEMPERATURES A FEW MORE DEGREES IN
THE TYPICAL ICE BOX LOCATIONS).
SOME UNCERTAINTY FOR THE REMAINDER OF THE WEEKEND INTO THE MIDDLE
PORTIONS OF NEXT WEEK...MAINLY CENTERING ON LIGHT PRECIP POTENTIAL
SUNDAY WITH MOISTURE STARVED NORTHERN STREAM WAVE...AND WITH
ADDITIONAL RAIN CHANCES TUESDAY AND WEDNESDAY. AS FOR THE
FORMER...POSITION OF AFOREMENTIONED LARGE SCALE FEATURES SUGGEST
"BEST" DYNAMICS AND WAA FORCED ASCENT REMAINING TO OUR WEST ON
SUNDAY. DRY NORTHEAST LOW LEVEL FLOW ALSO SUGGESTS DRY WEATHER
CONTINUING THROUGH SUNDAY. MAINTENANCE OF NEAR STATIONARY SURFACE
HIGH STILL SUPPORTS A DRY BEGINNING TO NEXT WORK WEEK UNDER MOSTLY
CLEAR TO PARTLY CLOUDY SKIES. TYPICAL SPRINGTIME AIRMASS
MODIFICATION RESULTS IN SOME SLOW WARMING...WITH HIGHS MOSTLY IN THE
LOWER 50S BY MONDAY (A TOUCH COOLER NEAR THE BIG LAKES AND ACROSS
EASTERN UPPER). MUCH UNCERTAINTY REMAINS WITH THE MID WEEK RAIN
POTENTIAL...WITH LATEST (AND RATHER ROCK STEADY) ECMWF SHOWING MUCH
MORE AMPLIFIED AND SLOWER TO LEAVE EASTERN LAKES/EASTERN US TROUGH
THAN OTHER GUIDANCE. ECMWF SOLUTION WOULD EVEN SUGGEST SOME ATLANTIC
MOISTURE PINWHEELING BACK WEST...BRINGING AT LEAST THE THREAT OF
SOME RAINS TO OUR EASTERN AREAS TUESDAY AND TUESDAY NIGHT. THIS DOES
SEEM A TOUCH EXTREME...ALTHOUGH FEEL ITS DEPICTION OF A MORE
AGGRESSIVE EASTERN TROUGH IS VERY PLAUSIBLE. OTHER PROGS...
ESPECIALLY THE SOMEWHAT MORE PROGRESSIVE GFS...WOULD SUGGEST A MID
WEEK SHOWER THREAT VIA ADDITIONAL NORTHERN STREAM ENERGY DROPPING ON
BACKSIDE OF SLOWLY DEPARTING EAST CANADA TROUGH AXIS. CONFIDENCE ON
HOW THIS WILL PLAY OUT REMAINS EXCEPTIONALLY LOW...AND WILL SIMPLY
RIDE WITH A MODEL BLEND APPROACH...FEATURING LOW END RAIN CHANCES
TUESDAY NIGHT INTO WEDNESDAY. TEMPERATURES WILL ALSO BE HIGHLY
DEPENDENT ON HOW THE ABOVE UNFOLDS...WITH SOME POTENTIAL FOR COOL
NORTHERLY FLOW TO CONTINUE. WILL SHOW A SLOW WARMING TREND...BUT
WOULD NOT BE SURPRISED IF THIS...AND RAIN POTENTIAL...SEES
SIGNIFICANT CHANGES IN THE COMING DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 140 AM EDT FRI APR 20 2012
APPROACHING LOW PRESSURE WILL CONTINUE TO PRODUCE NEAR STEADY
RAINFALL WITH MVFR VSBYS THROUGH THE MORNING...WITH IFC CIGS
THROUGH A GOOD CHUNK OF THE DAY. GUSTIER NE WINDS DEVELOP THROUGH
THE DAY AS THE LOW PRESSURE BEGINS TO DEPART THROUGH THE THUMB OF
LOWER MICHIGAN. VFR CONDITIONS DEVELOP BY THIS EVENING WITH MUCH
DRIER AIR ARRIVING AHEAD OF HIGH PRESSURE POKING INTO THE NW GREAT
LAKES.
&&
.MARINE...
ISSUED AT 433 PM EDT THU APR 19 2012
INCREASINGLY GUSTY NORTHEAST WINDS NORTH OF PASSING SOUTHERN LAKES
LOW PRESSURE WILL RESULT IN SCA/S ACROSS MOST NEARSHORE WATERS
BORDERING NORTHERN LOWER MICHIGAN TONIGHT INTO FRIDAY AFTERNOON.
STRONGEST WINDS EXPECTED OVER NORTHERN LAKE HURON LATE TONIGHT INTO
FRIDAY...WITH GALE FORCE WIND GUSTS EXPECTED FROM NEAR THE STRAITS
DOWN TO STURGEON POINT. CONDITIONS WILL IMPROVE FRIDAY NIGHT INTO
THE WEEKEND AS HIGH PRESSURE BUILDS OVERHEAD.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL NOON EDT TODAY FOR MIZ008-015>018.
LH...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LHZ345-
346-349.
GALE WARNING FROM 5 AM EARLY THIS MORNING TO 5 PM EDT THIS
AFTERNOON FOR LHZ347-348.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ323-
341-342-344>346.
LS...NONE.
&&
$$
UPDATE...SD
SYNOPSIS...SR
SHORT TERM...JB
LONG TERM...MB
AVIATION...SD
MARINE...MB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1129 PM CDT THU APR 19 2012
.UPDATE...
06Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
PRIMARY WEATHER FEATURES OF CONCERN ARE THE SHORTWAVE AND
ASSOCIATED SURFACE LOW CURRENTLY MOVING BY TO OUR SOUTH... AND
ANOTHER SHORTWAVE WHICH WILL BE EMBEDDED IN NORTHWEST UPPER FLOW
THAT WILL MOVE THROUGH THE REGION ON SATURDAY. OVERALL... THE
LARGE SCALE PATTERN WILL EVOLVE FROM ITS FAIRLY ZONAL FLOW AT THE
MOMENT TO A MUCH MORE AMPLIFIED PATTERN AS WE WORK THROUGH THE
UPCOMING WEEK. THE NUMERICAL GUIDANCE IS IN GOOD AGREEMENT ON THE
INITIAL AMPLIFICATION OF THE UPPER FLOW... BUT DIVERGES QUITE A
BIT IN HOW THINGS WILL THEN EVOLVE DURING THE MIDDLE PART OF NEXT
WEEK. GENERALLY FOLLOWED A NAM/GFS BLEND THROUGH THE NEXT FEW
DAYS... THEN STEADILY WORKED WITH MORE OF AN ECMWF/GFS BLEND
BEYOND THAT WITH A BIT MORE WEIGHT ON THE ECMWF BY THE MIDDLE OF
NEXT WEEK. OVERALL... CONFIDENCE IS FAIRLY LOW IN THE DETAILS OF
THE TUESDAY THROUGH THURSDAY TIME PERIOD NEXT WEEK... SINCE MUCH
WILL DEPEND ON IF/WHEN THE RIDGE WILL BREAK DOWN. THE ECMWF
MAINTAINS THE RIDGE MUCH MORE THAN THE GFS... WHICH PUSHES AN
UPPER LOW SOUTH TOWARD THE REGION FROM CENTRAL CANADA.
SURFACE LOW CURRENTLY OVER FAR NORTHEAST KANSAS WILL CONTINUE TO
PUSH EAST-NORTHEAST THIS EVENING AS THE UPPER SHORTWAVE WORKS INTO
THE MID-MISSISSIPPI VALLEY. THE BEST ISENTROPIC LIFT AND MID-LEVEL
FRONTOGENESIS WILL BE ACROSS THE SOUTHERN PART OF OUR CWFA AND
INTO NORTHERN IOWA AND SOUTHWEST WISCONSIN. DECENT PCPN TOTALS CAN
BE EXPECTED SOUTH OF A LINE FROM MANKATO TO EAU CLAIRE AS THE
SYSTEM PUSHES THROUGH THIS AFTERNOON AND EVENING. THE BACK EDGE OF
THE PCPN MAY MIX WITH AND/OR CHANGE TO SOME SNOW THIS EVENING AS
COLDER AIR WORKS IN BEHIND THE UPPER WAVE. FORECAST SOUNDINGS FROM
THE NAM... GFS... AND RUC SUGGEST ONLY A BRIEF WINDOW OF SNOW
POTENTIAL ACROSS OUR AREA... MAINLY OVER PARTS OF WEST CENTRAL
WISCONSIN. BETTER ACCUMULATION POTENTIAL EXISTS EAST AND SOUTHEAST
OF OUR AREA... WHERE THERE LOOKS TO BE A LONGER DURATION OF A SUB-
FREEZING PROFILE... DEEP MOISTURE... AND LIFT. A WEAK RIDGE OF
HIGH PRESSURE WILL WORK ACROSS THE REGION LATE TONIGHT THROUGH
FRIDAY... WITH DRY WEATHER EXPECTED. THE RIDGE WILL STILL BE IN
PLACE ACROSS THE EASTERN FORECAST AREA FRIDAY NIGHT... WHICH COULD
LEAD TO SOME FROST/FREEZE ISSUES. INCLUDED A MENTION OF PATCHY
FROST IN THOSE AREAS FOR NOW TO ACCOUNT FOR THAT POSSIBILITY.
RETURN FLOW AND WARM ADVECTION WILL START TO ENCROACH ON THE
WESTERN PORTION OF THE AREA FRIDAY NIGHT... SO INCLUDED A CHANCE
OF SHRA OUT THERE FOR THE OVERNIGHT HOURS. THAT CHANCE FOR PCPN
THEN MIGRATES EASTWARD ACROSS THE AREA ON SATURDAY AS THE ZONE OF
ISENTROPIC LIFT WORKS ACROSS THE CWFA WITH AN EMBEDDED SHORTWAVE
IN NORTHWEST FLOW DROPPING THROUGH AT THE SAME TIME. THE MOST
PERSISTENT AND SUBSTANTIAL PCPN LOOKS LIKE IT SHOULD FOCUS MAINLY
TO OUR NORTH... BUT WOULD EXPECT MOST LOCATIONS TO SEE AT LEAST A
BRIEF WINDOW OF SOME PCPN ON SATURDAY INTO SATURDAY NIGHT. PCPN
CHANCES MAY LINGER ACROSS THE EAST ON SUNDAY ON THE BACKSIDE OF
THE UPPER TROUGH BEFORE MORE PRONOUNCED UPPER AND SURFACE RIDGING
ARE ABLE TO WORK INTO THE AREA.
FOR THE MONDAY THROUGH THURSDAY PERIOD... CONFIDENCE IS QUITE LOW
IN THE FORECAST DETAILS AS ELUDED TO EARLIER. TRIED TO SIDE A BIT
MORE WITH THE ECMWF... ALTHOUGH IT SHOULD BE NOTED THAT ITS 12Z
SOLUTION DID TREND SLIGHTLY TOWARD THE GFS IN THE IDEA OF
SQUASHING THE EAST SIDE OF THE UPPER RIDGE A BIT BY WEDNESDAY-
THURSDAY. GIVEN THE UNCERTAINTY AND SPREAD IN SOLUTIONS... WENT
WITH A BLENDED APPROACH WHICH RESULTS IN A LONGER PERIOD OF CHANCE
POPS THAN WHAT WILL LIKELY OCCUR. HOPEFULLY SUBSEQUENT FORECASTS
WILL BE ABLE TO REFINE THE MOST LIKELY LOCATIONS AND TIME PERIODS
FOR PCPN DURING THE PERIOD.
&&
.AVIATION.../06Z TAF ISSUANCE/
SYSTEM THAT BROUGHT RA TO THE AREA THROUGH THIS PAST EVENING
PULLING EAST TONIGHT...WITH PCPN LIKELY OUT OF EAU BY 06Z. MAY BE
A BRIEF MVFR CIG FOR THE FIRST HOUR OR TWO AT EAU...OTHERWISE VFR
CONDITIONS WILL DOMINATE. SFC RIDGE MOVING ACROSS MN WILL LEAD TO
FAIRLY LIGHT WINDS...WITH STRONGEST WINDS EXPECTED INTO THE EARLY
AFTERNOON OVER WI...WHERE CLOSER PROXIMITY TO THE SFC LOW WILL
KEEP THE PRESSURE GRADIENT A BIT STRONGER. OUT IN WRN MN...MID
CLOUDS CURRENTLY OVER NODAK WILL DRIFT INTO WRN MN THROUGH THE
MORNING...WITH 5K TO 10K FT CIGS POSSIBLE THROUGH MUCH OF THE DAY
AT AXN. NEXT SYSTEM WILL BE APPROACHING WRN TERMINALS LATE FRIDAY
NIGHT...WITH NEXT TAF NEEDING TO START THINKING ABOUT PCPN FOR AXN
AND MSP TOWARD THE END OF THEIR RESPECTIVE 12Z TAF PERIODS. WINDS
WILL BASICALLY BE OUT OF THE NORTH THROUGH THE DAY...THOUGH RETURN
FLOW SE WINDS WILL START DEVELOPING OVER MN AFTER 00Z.
KMSP...NO ISSUES EXPECTED THIS TAF PERIOD...WITH MUCH OF THE
AFTERNOON INTO EVENING EXPECTED TO BE SPENT WITH SKC CONDITIONS.
BIGGEST CHALLENGE THIS TAF PERIOD WILL BE TIMING WIND SHIFT OVER
TO THE SE...THOUGH THIS LOOKS TO OCCUR BEFORE TRAFFIC PICKS UP SAT
MORNING.
//OUTLOOK...SATURDAY THROUGH TUESDAY...
SAT...PERIODS OF -SHRA WITH MVFR CIGS/VIS POSSIBLE.
SUN...IFR/MVFR CIGS POSSIBLE THROUGH THE MORNING.
MON-TUE...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/MPG
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1135 PM CDT THU APR 19 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
/640 PM CDT THU APR 19 2012/
Have made adjustments to timing/areal coverage of evening/overnight
convection based on latest short range convective models and radar
trends. Minimal severe threat this evening. Have updated/adjusted
HWO. SPC meso page still shows decent amount of CIN while surface-
based CAPE in 250-500 range are pretty meager while 0-6km bulk shear
is below marginal values along the frontal boundary. Scattered
elevated showers forming over north central MO should build back to
the southwest with time and become more organized as the region of
elevated lift shifts east.
MJ
&&
.PREV DISCUSSION...
/419 PM CDT Thu Apr 19 2012/
Short Range (Tonight through Saturday)...
Satellite imagery from this afternoon shows the nation under the
influence of a progressive pattern, though some buckling of the
flow is apparent as a trough is seen exiting the Rocky Mountains.
Closer to home, a small shortwave ejected into the Plains ahead of
the primary trough exiting the mountainous west, and helped focus
the morning low level jet across northeast Kansas and northwest
Missouri, which resulted in some morning thunderstorms. Those storms
have since dissipated, leaving our attention focused back to our
west, where a cold front is advancing east across Kansas tied to the
leading shortwave.
Currently the front is located along a line from the tip of
northwest Missouri to Wichita, with a fair amount of cumulus cloud
cover bubbling up ahead of the front. Early afternoon soundings show
little in the way of available CAPE across our section of eastern
Kansas and Missouri, as RUC based analysis indicates there is only
about 500 J/KG of SBCAPE, and given the dry layer at the 700mb level
noted off an early afternoon sounding at KMCI, there was no ability
for the model to evaluate MLCAPE. The lack of instability looks to be
from both the cloud cover in advance of the front, and due to lower
than expected dew points, which have struggled to clime beyond the
low 50s. However, with the front advancing across Kansas, frontogenic
forcing is still expected to use what little CAPE is available late
this afternoon/early this evening to generate some scattered storms
in eastern Kansas. The storms should move northeast, but the line
will struggle to fill in unless more quality moisture can quickly
advect ahead of the front. Shear parameters for this evening are
more than sufficient to generate concerns for severe weather, but
given the lack of instability, and the way surface winds veer off as
the front moves through, and it is looking increasingly difficult for
us to realize any storms that could support much more than marginal
severe weather, which would be limited to large hail and damaging
straight line winds. Heavy rain may occur with some of these storms,
but at this time the lack of quality moisture and the progressive
nature of the front should preclude any widespread flooding threat.
With the continued consensus of the various short range operational
and ensemble models, have persisted in quickly moving the storms to
the east, leaving most of the forecast area dry after 12Z Friday.
Being behind the front Friday will allow for something we have not
seen a whole lot of in the past several months, cold air advection.
The breezy north wind behind the front will actually keep afternoon
highs below normal Friday. However, this cool trend will quickly
fade as southwest winds return for Saturday bringing highs in the 60s
back.
Cutter
Medium Range (Sunday through Thursday)...
No major changes planned to going medium range forecast. Upper
ridge axis forecast to strengthen over western US during early part
of next week while area of surface high pressure builds into
forecast area. By mid-week the upper feature shifts into the
central US. This combined with increasing southerly flow as surface
high moves to the east should provide for a gradual warm up.
Appears that temperatures could approach the 80 degree mark by
Wednesday and then again on Thursday. ECMWF, GFS, and GEM models
hinting at weak mid-level shortwave topping ridge in upper
Mississippi Valley in the Wednesday/Thursday time frame. Not out of
the realm of possibility to see some scattered precipitation over
northern Missouri with this feature. However there are enough
inconsistencies in the timing and geographic placement of the QPF
that dry forecast still appears to be the best way to go at this
time.
MJM
&&
.AVIATION...
For the 06 TAFs...In the wake of the cold frontal passage a large
area of MVFR cigs have overspread all 3 terminals. These cigs will
remain in place through around mid morning before cigs gradually
improve with breaks in the overcast, finally reaching VFR category
by around the noon hour. Gusty northerly winds expected until late
afternoon when clouds clear out and the pressure gradient relaxes.
MJ
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
622 AM CDT FRI APR 20 2012
.UPDATE...
.AVIATION...
MIXED VFR/MVFR/IFR SHOULD IMPROVE TO MOSTLY VFR BY LATE MORNING.
THE RUC CONTINUES TO INDICATE A SMALL AREA OF MVFR THROUGH MID
AFTERNOON NEAR KANW-KBBW. VFR IS EXPECTED ALL AREAS BY 21Z AND
CONTINUING THROUGH 12Z SATURDAY. AN UPPER LEVEL DISTURBANCE
TRACKING THROUGH THE UPPER MIDWEST IS EXPECTED TO SPREAD BKN-
OVC100 CIGS THROUGH THE FCST AREA TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 349 AM CDT FRI APR 20 2012/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
A PATTERN CHANGE IS IN STORE FOR NEBRASKA THROUGH THIS TIME
PERIOD...GOING FROM FAST FLOW WITH SYSTEMS MOVING THROUGH ALMOST
DAILY TO A BUILDING RIDGE LEADING TO DRIER AND WARMER CONDITIONS.
AT 20.08Z WATER VAPOR IMAGERY SHOWED A SHORTWAVE TROUGH OVER THE
NEBRASKA PANHANDLE WITH RIDGING UPSTREAM IN SOUTHWEST CANADA AND
ANOTHER SHORTWAVE TROUGH PUSHING INTO BRITISH COLUMBIA. GOOD
SUBSIDENCE AND DARKENING WAS SEEN BEHIND THE NEBRASKA
SHORTWAVE...AND WHEN LOOKING AT IR IMAGERY EARLY THIS
MORNING...DID SEE CLEARING SKIES ACROSS THE PANHANDLE AND FAR
WESTERN NEBRASKA. CLOUDS...ALONG WITH SHOWERS REMAINED ACROSS THE
AREA FROM SOUTHWEST TO NORTHEAST...AHEAD OF THE SHORTWAVE.
FOR TODAY THE UPPER LEVEL SHORTWAVE TROUGH WILL DIG
SOUTHEAST OF THE FORECAST AREA...ALLOWING RIDGING TO START BUILDING
INTO THE FORECAST AREA. WITH DECENT SUBSIDENCE BEHIND THE
SHORTWAVE...SHOULD CONTINUE TO SEE SKIES CLEAR...ALTHOUGH IT MAY
TAKE MUCH OF THE MORNING IN SOME PLACES AS LOW LEVEL MOISTURE BELOW
THE INVERSION MAY TAKE SOME TIME TO SCOUR OUT. WITH THE CLOUD
COVER AND WITH TEMPERATURES ALOFT BEING SLOW TO WARM UP...DON/T
EXPECT TEMPERATURES TO RISE TOO HIGH TODAY. LOOKING FOR
HIGHS...EVEN WITH SUN AROUND 60 DEGREES.
ANOTHER DISTURBANCE /THE SHORTWAVE MOVING INTO BRITISH COLUMBIA/
WILL PUSH OVER THE RIDGE TONIGHT AND ON SATURDAY. DUE TO THE RIDGE
BUILDING EAST...THE STORM TRACK WITH THIS NEXT DISTURBANCE SHOULD
STAY NORTH AND EAST OF THE FORECAST AREA. MAY GET SOME CLOUDY
SKIES LATER IN THE DAY AND INTO THE DAY SATURDAY ACROSS NORTH
CENTRAL NEBRASKA. A COLD FRONT WILL BE PUSHED SOUTHEAST ACROSS THE
AREA ON SATURDAY ASSOCIATED WITH THIS SYSTEM. BUT...WITH MOISTURE
STAYING CLOSER TO THE SURFACE LOW OVER THE DAKOTAS AND IOWA...DO
NOT ANTICIPATE THE NEED FOR ANY RAIN CHANCES IN THE FORECAST FOR
TONIGHT OR SATURDAY. THIS WILL NEED TO BE WATCHED THOUGH AS THERE
HAS BEEN THE SUGGESTION FROM A MODEL HERE AND THERE THAT SHOWERS
COULD SNEAK SOUTHWARD AND INTO THE AREA ON SATURDAY.
EVEN WITH THE PASSING OF THE COLD FRONT...TEMPERATURES ALOFT /AT
850MB/ INCREASE BY 4 TO 6 DEGREES FROM 21.00Z TO 22.00Z. SO
LOOKING AT WARMER TEMPERATURES ON SATURDAY...LIKELY IN THE UPPER
60S AND 70S ACROSS THE FORECAST AREA. CLOUD COVER OVER THE
NORTHEAST MAY SLOW WARMING UP AND MAY KEEP HIGHS A BIT
COOLER...BUT LESSER CLOUDS ARE EXPECTED OVER THE SOUTH AND WESTERN
AREAS. SOMETHING IN FAVOR OF WARMING IS THE NORTHWEST SURFACE
FLOW...CAUSING A DOWNSLOPE AND WARMING EFFECT...TO HELP WARMING
INTO THE 70S. WINDS DO LOOK TO BE A BIT BREEZY BEHIND THE PASSING
FRONT ON SATURDAY...BUT SHOULD DIMINISH BY EVENING AS HIGH
PRESSURE BUILDS IN.
THE UPPER LEVEL FLOW AMPLIFIES FURTHER ON SUNDAY AS THE TROUGH
OVER THE EASTERN CONUS DIGS INTO THE DEEP SOUTH AND THE RIDGE
BUILDS OVER THE ROCKIES. TEMPERATURES AT 850MB WILL SEE A DECENTLY
SHARP GRADIENT...VARYING FROM 6C TO 20C AT 23.00Z FROM EASTERN TO
WESTERN NEBRASKA RESPECTIVELY.
LONG TERM...MONDAY THROUGH THURSDAY
THE WORK WEEK BEGINS WILL WELL ABOVE NORMAL TEMPERATURES AS THE
MODELS CONTINUE TO HAVE A SIMILAR HANDLE ON THE UPPER LEVEL
PATTERN THROUGH TUESDAY. THROUGH THIS TIME...HIGHLY AMPLIFIED FLOW
EXISTS WITH UPPER LOWS OVER BOTH THE EASTERN CONUS AND THE EASTERN
PACIFIC...WITH STRONG RIDGING ACROSS THE WESTERN AND CENTRAL
CONUS.
GFS ENSEMBLE STANDARDIZED ANOMALIES CONTINUE TO SHOW STRONG
SIGNALS FOR WELL ABOVE NORMAL TEMPERATURES FOR MONDAY AND
TUESDAY...WITH TEMPERATURES AT 2 TO 3 STANDARD DEVIATIONS ABOVE
NORMAL FROM MONDAY THROUGH WEDNESDAY. AS STATED LAST NIGHT...DON/T
ANTICIPATE RECORD HIGHS BUT WELL ABOVE NORMAL FOR THIS TIME OF
YEAR. THE SIGNAL IS STILL THERE FOR WEDNESDAY...BUT WITH LESSER
CONFIDENCE DUE TO MODELS BEGINNING TO DIVERGE. DIFFERENCES BEYOND
TUESDAY INCLUDE THE GFS WANTING TO MOVE THE CLOSED UPPER LEVEL LOW
ACROSS THE GREAT BASIN AND INTO THE SOUTHERN PLAINS BY
THURSDAY...WHILE THE ECMWF...GEM AND GFS ENSEMBLE MEAN KEEPS THE
CLOSED LOW OFF THE CALIFORNIA COAST. MEANWHILE IN THE NORTHERN
STREAM...FOR WEDNESDAY SEVERAL SOLUTIONS WOULD SUGGEST A SLIGHT
FLATTENING OF THE RIDGE MEANING THE POSSIBILITY FOR SOME COLD AIR
ADVECTION...AND COOLER TEMPERATURES FOR WEDNESDAY. WILL TAKE A
CONSENSUS APPROACH FOR TEMPERATURES THROUGH THIS TIME AND WILL
KEEP THE FORECAST DRY THROUGH THIS TIME WITH LITTLE CONFIDENCE ON
THE TIMING OF ANY SHORTWAVE MOVING OVER THE RIDGE WITH ENOUGH
STRENGTH TO PUSH PRECIPITATION INTO NEBRASKA.
AVIATION...
THE BANK OF MVFR/LOCAL IFR CIGS ACROSS NCNTL NEB IS EXPECTED TO
CONTINUE TO ERODE THROUGH 18Z THIS MORNING. VFR IS GENERALLY
EXPECTED AFTER 18Z THROUGH 12Z SATURDAY MORNING.
ONE CAVEAT IS THAT THE RUC WHICH RUNS THROUGH ONLY 18Z THIS MORNING
SHOWS A NARROW AREA OF MVFR ALONG HWY 83 LINGERING AT 18Z. THE OTHER
MODELS SUGGEST VFR AT THIS TIME. THUS LOCAL MVFR CONDITIONS ARE
POSSIBLE 18Z THROUGH 21Z WITH VFR THEREAFTER.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...CDC
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
349 AM CDT FRI APR 20 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
A PATTERN CHANGE IS IN STORE FOR NEBRASKA THROUGH THIS TIME
PERIOD...GOING FROM FAST FLOW WITH SYSTEMS MOVING THROUGH ALMOST
DAILY TO A BUILDING RIDGE LEADING TO DRIER AND WARMER CONDITIONS.
AT 20.08Z WATER VAPOR IMAGERY SHOWED A SHORTWAVE TROUGH OVER THE
NEBRASKA PANHANDLE WITH RIDGING UPSTREAM IN SOUTHWEST CANADA AND
ANOTHER SHORTWAVE TROUGH PUSHING INTO BRITISH COLUMBIA. GOOD
SUBSIDENCE AND DARKENING WAS SEEN BEHIND THE NEBRASKA
SHORTWAVE...AND WHEN LOOKING AT IR IMAGERY EARLY THIS
MORNING...DID SEE CLEARING SKIES ACROSS THE PANHANDLE AND FAR
WESTERN NEBRASKA. CLOUDS...ALONG WITH SHOWERS REMAINED ACROSS THE
AREA FROM SOUTHWEST TO NORTHEAST...AHEAD OF THE SHORTWAVE.
FOR TODAY THE UPPER LEVEL SHORTWAVE TROUGH WILL DIG
SOUTHEAST OF THE FORECAST AREA...ALLOWING RIDGING TO START BUILDING
INTO THE FORECAST AREA. WITH DECENT SUBSIDENCE BEHIND THE
SHORTWAVE...SHOULD CONTINUE TO SEE SKIES CLEAR...ALTHOUGH IT MAY
TAKE MUCH OF THE MORNING IN SOME PLACES AS LOW LEVEL MOISTURE BELOW
THE INVERSION MAY TAKE SOME TIME TO SCOUR OUT. WITH THE CLOUD
COVER AND WITH TEMPERATURES ALOFT BEING SLOW TO WARM UP...DON/T
EXPECT TEMPERATURES TO RISE TOO HIGH TODAY. LOOKING FOR
HIGHS...EVEN WITH SUN AROUND 60 DEGREES.
ANOTHER DISTURBANCE /THE SHORTWAVE MOVING INTO BRITISH COLUMBIA/
WILL PUSH OVER THE RIDGE TONIGHT AND ON SATURDAY. DUE TO THE RIDGE
BUILDING EAST...THE STORM TRACK WITH THIS NEXT DISTURBANCE SHOULD
STAY NORTH AND EAST OF THE FORECAST AREA. MAY GET SOME CLOUDY
SKIES LATER IN THE DAY AND INTO THE DAY SATURDAY ACROSS NORTH
CENTRAL NEBRASKA. A COLD FRONT WILL BE PUSHED SOUTHEAST ACROSS THE
AREA ON SATURDAY ASSOCIATED WITH THIS SYSTEM. BUT...WITH MOISTURE
STAYING CLOSER TO THE SURFACE LOW OVER THE DAKOTAS AND IOWA...DO
NOT ANTICIPATE THE NEED FOR ANY RAIN CHANCES IN THE FORECAST FOR
TONIGHT OR SATURDAY. THIS WILL NEED TO BE WATCHED THOUGH AS THERE
HAS BEEN THE SUGGESTION FROM A MODEL HERE AND THERE THAT SHOWERS
COULD SNEAK SOUTHWARD AND INTO THE AREA ON SATURDAY.
EVEN WITH THE PASSING OF THE COLD FRONT...TEMPERATURES ALOFT /AT
850MB/ INCREASE BY 4 TO 6 DEGREES FROM 21.00Z TO 22.00Z. SO
LOOKING AT WARMER TEMPERATURES ON SATURDAY...LIKELY IN THE UPPER
60S AND 70S ACROSS THE FORECAST AREA. CLOUD COVER OVER THE
NORTHEAST MAY SLOW WARMING UP AND MAY KEEP HIGHS A BIT
COOLER...BUT LESSER CLOUDS ARE EXPECTED OVER THE SOUTH AND WESTERN
AREAS. SOMETHING IN FAVOR OF WARMING IS THE NORTHWEST SURFACE
FLOW...CAUSING A DOWNSLOPE AND WARMING EFFECT...TO HELP WARMING
INTO THE 70S. WINDS DO LOOK TO BE A BIT BREEZY BEHIND THE PASSING
FRONT ON SATURDAY...BUT SHOULD DIMINISH BY EVENING AS HIGH
PRESSURE BUILDS IN.
THE UPPER LEVEL FLOW AMPLIFIES FURTHER ON SUNDAY AS THE TROUGH
OVER THE EASTERN CONUS DIGS INTO THE DEEP SOUTH AND THE RIDGE
BUILDS OVER THE ROCKIES. TEMPERATURES AT 850MB WILL SEE A DECENTLY
SHARP GRADIENT...VARYING FROM 6C TO 20C AT 23.00Z FROM EASTERN TO
WESTERN NEBRASKA RESPECTIVELY.
.LONG TERM...MONDAY THROUGH THURSDAY
THE WORK WEEK BEGINS WILL WELL ABOVE NORMAL TEMPERATURES AS THE
MODELS CONTINUE TO HAVE A SIMILAR HANDLE ON THE UPPER LEVEL
PATTERN THROUGH TUESDAY. THROUGH THIS TIME...HIGHLY AMPLIFIED FLOW
EXISTS WITH UPPER LOWS OVER BOTH THE EASTERN CONUS AND THE EASTERN
PACIFIC...WITH STRONG RIDGING ACROSS THE WESTERN AND CENTRAL
CONUS.
GFS ENSEMBLE STANDARDIZED ANOMALIES CONTINUE TO SHOW STRONG
SIGNALS FOR WELL ABOVE NORMAL TEMPERATURES FOR MONDAY AND
TUESDAY...WITH TEMPERATURES AT 2 TO 3 STANDARD DEVIATIONS ABOVE
NORMAL FROM MONDAY THROUGH WEDNESDAY. AS STATED LAST NIGHT...DON/T
ANTICIPATE RECORD HIGHS BUT WELL ABOVE NORMAL FOR THIS TIME OF
YEAR. THE SIGNAL IS STILL THERE FOR WEDNESDAY...BUT WITH LESSER
CONFIDENCE DUE TO MODELS BEGINNING TO DIVERGE. DIFFERENCES BEYOND
TUESDAY INCLUDE THE GFS WANTING TO MOVE THE CLOSED UPPER LEVEL LOW
ACROSS THE GREAT BASIN AND INTO THE SOUTHERN PLAINS BY
THURSDAY...WHILE THE ECMWF...GEM AND GFS ENSEMBLE MEAN KEEPS THE
CLOSED LOW OFF THE CALIFORNIA COAST. MEANWHILE IN THE NORTHERN
STREAM...FOR WEDNESDAY SEVERAL SOLUTIONS WOULD SUGGEST A SLIGHT
FLATTENING OF THE RIDGE MEANING THE POSSIBILITY FOR SOME COLD AIR
ADVECTION...AND COOLER TEMPERATURES FOR WEDNESDAY. WILL TAKE A
CONSENSUS APPROACH FOR TEMPERATURES THROUGH THIS TIME AND WILL
KEEP THE FORECAST DRY THROUGH THIS TIME WITH LITTLE CONFIDENCE ON
THE TIMING OF ANY SHORTWAVE MOVING OVER THE RIDGE WITH ENOUGH
STRENGTH TO PUSH PRECIPITATION INTO NEBRASKA.
&&
.AVIATION...
THE BANK OF MVFR/LOCAL IFR CIGS ACROSS NCNTL NEB IS EXPECTED TO
CONTINUE TO ERODE THROUGH 18Z THIS MORNING. VFR IS GENERALLY
EXPECTED AFTER 18Z THROUGH 12Z SATURDAY MORNING.
ONE CAVEAT IS THAT THE RUC WHICH RUNS THROUGH ONLY 18Z THIS MORNING
SHOWS A NARROW AREA OF MVFR ALONG HWY 83 LINGERING AT 18Z. THE OTHER
MODELS SUGGEST VFR AT THIS TIME. THUS LOCAL MVFR CONDITIONS ARE
POSSIBLE 18Z THROUGH 21Z WITH VFR THEREAFTER.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...BROOKS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
131 AM EDT FRI APR 20 2012
.SYNOPSIS...
A NEARLY STATIONARY FRONT LOCATED JUST OFFSHORE WILL DISSIPATE
FRIDAY. LOW PRESSURE IS EXPECTED TO DEVELOP IN THE NORTHERN GULF OF
MEXICO SATURDAY...MOVING UP THE SOUTHEAST ATLANTIC COAST ON SUNDAY
WITH A SIGNIFICANT RAIN EVENT POSSIBLE FOR AT LEAST THE COASTAL
CAROLINAS. HIGH PRESSURE WILL BUILD IN FROM THE WEST THROUGH THE
MIDDLE OF NEXT WEEK WITH DRY WEATHER AND BELOW-NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH 6 AM EDT FRIDAY/...
AS OF 130 AM FRIDAY...PREVIOUS FORECAST REMAINS IN EXCELLENT SHAPE
AND FEW CHANGES WERE NEEDED EARLY THIS MORNING. PREVIOUS DISCUSSION
FROM 10 PM FOLLOWS...
LATEST 88D PCPN COVERAGE WIDELY SCATTERED AT THE MOMENT. COASTAL
COUNTIES WILL REMAIN UNDER THE THREAT FOR SHRA INTO THE PRE-DAWN HRS
OF FRIDAY. THE HRRR SEEMS TO BE HANDLING THIS PCPN MUCH BETTER THAN
ORIGINALLY THOUGHT. THE WEAK MID LEVEL S/W MOVING OFFSHORE JUST
SOUTH OF THE ILM CWA SEEMS TO HAVE THE AVAILABLE DYNAMICS TO AID IN
THE GENERATION OF PCPN ALONG THE IMMEDIATE COAST AND THEIR ADJACENT
ATL WATERS. 00Z MHX AND CHS RAOBS ILLUSTRATE NEARLY SATURATED
CONDITIONS SFC THRU 800MB. THE OVERCAST LOW LEVEL STRATUS CLOUD DECK
TO BECOME THE DOMINATE SKY CONDITION FOR THE REMAINDER OF THE
OVERNIGHT. WITH REFERENCE TO FOG POTENTIAL...THE GFS MODEL MOS
GUIDANCE INDICATES WIDESPREAD FOG WITH POCKETS OF DENSE...AND IS
FAVORED OVER THE NAM MOS WHICH INDICATES A MUCH LOWER THREAT FOR
FOG.
LOOKING AT LOW LEVEL PROGGED PARTIAL THICKNESSES AND 8H PROGGED
TEMPS...NO ADDITIONAL CAA IS EXPECTED...IN FACT IT FAVORS A NEUTRAL
TEMP ADVECTION DURING THE REMAINDER OF THE OVERNIGHT. TONIGHTS MINS
REMAIN UNCHANGED...WHICH REMAINS ON THE HIGHER SIDE OF MOS
GUIDANCE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2 PM THURSDAY...A FLAT H5 RIDGE ACROSS THE SOUTHEASTERN UNITED
STATES ON FRIDAY WILL LIFT EAST ON SATURDAY AS A LARGE UPPER LOW
BEGINS TO TAKE SHAPE OVER THE NORTHERN GULF OF MEXICO. THE LOW WILL
EJECT AN IMPULSE UP THE COAST SATURDAY NIGHT RESULTING IN INCREASING
CHANCES FOR CONVECTION...ESPECIALLY LATER IN THE SHORT TERM PERIOD.
AT THE SURFACE...LOW PRESSURE IS EXPECTED TO RIDE UP JUST OFF THE
COAST SATURDAY NIGHT...THUS THE HIGHEST QPF AMOUNTS ARE EXPECTED TO
BE ALONG THE COASTAL COUNTIES. MAV/MET NUMBERS ARE RELATIVELY CLOSE
THROUGH THE PERIOD...AND SAW NO REASON AT THIS TIME TO STRAY TOO FAR
FROM THEM. THESE TEMPERATURES WILL RANGE ABOVE NORMAL EACH PERIOD
AHEAD OF THE AFOREMENTIONED DEVELOPING UPPER LOW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 2 PM THURSDAY...MEDIUM RANGE MODELS APPEAR TO BE DIVIDING INTO
TWO CAMPS REGARDING THE SIGNIFICANT SYSTEM FOR LATE IN THE WEEKEND
EXTENDING INTO EARLY NEXT WEEK. THE OPERATIONAL GFS IS ADVERTISING
AN EVER INCREASING PROGRESSIVE TREND WITH THE MID LEVEL LOW WHILE
THE GFS PARALLEL (GFS EXPERIMENTAL MODEL) IS SLOWER AND MORE IN LINE
WITH THE ECMWF SUITE OF PRODUCTS.
WILL CONTINUE TO FOLLOW THE HPC FAVORED SLOWER SOLUTION AS IT OFFERS
MORE CONTINUITY WITH PREVIOUS FORECAST. LARGE SWATH OF MOISTURE
EXPECTED TO INUNDATE THE FORECAST AREA SUNDAY WITH MID LEVEL
DEFORMATION BEING THE DRIVING FORCE.
THE REMAINDER OF THE FORECAST...FROM MONDAY ON IS DRY WITH
TEMPERATURES BELOW CLIMATOLOGY AT LEAST THROUGH WEDNESDAY. MIXED
BOUNDARY LAYER SHOULD KEEP TEMPERATURES IN THE MIDDLE 40S TUESDAY
MORNING WITH A MODIFYING AIRMASS BUT MORE CONDUCIVE RADIATIONAL
CONDITIONS YIELDING A DEGREE OR TWO LOWER WEDNESDAY MORNING. DAYTIME
HIGHS...SOMEWHAT BELOW CLIMATOLOGY EARLY WILL QUICKLY MODERATE TO
SEASONAL NORMALS BY WEDNEDAY AND THURSDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...A RATHER DIFFICULT AND LOW-CONFIDENCE FORECAST SHAPING
UP THROUGH THIS MORNING. MVFR STRATUS COVERS MUCH OF THE EASTERN
CAROLINAS CURRENTLY. WE ARE ON THE "COLD" SIDE OF A WEAK STATIONARY
FRONT THAT IS DISSIPATING ABOUT 60-100 MILES OFFSHORE. 00Z MODEL
GUIDANCE INITIALIZED POORLY AS IT SHOWS WE SHOULD HAVE WIDESPREAD
IFR CIGS CURRENTLY. THE STRATUS BASES SHOULD DROP SLOWLY OVER THE
NEXT FEW HOURS WITH IFR CIGS POTENTIALLY DEVELOPING BETWEEN
07-10Z...FIRST AT ILM THEN SPREADING SOUTH AND WEST THROUGH THE
MYRTLE BEACH VICINITY AND EVENTUALLY TO FLO. OUR CONFIDENCE REMAINS
LOW HOWEVER AS LOCAL CLIMATE TOOLS SHOW LIGHT NE SFC WINDS AND MVFR
CIGS DO NOT OFTEN RESULT IN WIDESPREAD IFR THIS TIME OF YEAR.
AFTER DAYBREAK ANY IFR CIGS WILL RISE TO AN MVFR BKN LAYER BY
15Z...THEN SCATTERING OUT THIS AFTERNOON AS EAST AND SOUTHEAST SFC
WINDS DEVELOP THROUGHOUT THE REGION FORMERLY OCCUPIED BY THE OLD
DECAYED FRONT.
EXTENDED OUTLOOK...MVFR/POSSIBLE IFR CONDITIONS FRI NIGHT IN FOG AND
LOW STRATUS...THEN AGAIN IN SCATTERED SHOWERS SATURDAY. NUMEROUS
SHOWERS/TEMPO IFR POSSIBLE SUNDAY...MAINLY NEAR THE COAST. VFR
MONDAY AND TUESDAY WITH ISOLATED SHOWERS MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM FRIDAY...VIRTUALLY NO CHANGES TO THE PREVIOUS FORECAST
WHICH IS IN EXCELLENT SHAPE EARLY THIS MORNING. PREVIOUS DISCUSSION
FROM 10 PM FOLLOWS...
COLD FRONT LIES NEARLY STATIONARY JUST E AND S OF THE ILM COASTAL
WATERS. NORTHEAST TO EAST 10-15 KT WINDS WILL PREMIERE ACROSS ALL
ILM WATERS OVERNIGHT...WITH A BRIEF WINDOW OF SUSTAINED 15 KT DUE TO
THE SLIGHTLY PINCHED SFC PRESSURE GRADIENT. SIGNIFICANT SEAS WILL
PRIMARILY BE DRIVEN TONIGHT BY A SOLID EASTERLY 1-2 FOOT GROUND
SWELL EXHIBITING 12 TO 14 SECOND PERIODS. THE ADDITION OF THE
LOCALLY PRODUCED WIND DRIVEN WAVES TO SIGNIFICANT SEAS...WILL
COMBINE WITH THE SWELL TO YIELD AN OVERALL 2 TO 4 FT SIG. SEAS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2 PM THURSDAY...THE WEAK FRONT OVER THE WATERS FRIDAY MORNING
WILL GRADUALLY DISSIPATE. THE FLOW WILL BECOME SOUTHERLY DURING THE
AFTERNOON AFTER THE FRONT DISSOLVES. THE SOUTHERLY PRESSURE GRADIENT
WILL KEEP SOUTHERLY FLOW AROUND 15 KNOTS OR LESS SATURDAY INTO
SATURDAY EVENING. THEN WITH POSSIBLE LOW BEGINNING TO RIDE UP THE
COAST THE FLOW MAY BACK OVERNIGHT SATURDAY NIGHT. SEAS WILL BE
DOMINATED BY AN EASTERLY SWELLS FRIDAY. THE SWELLS WILL GRADUALLY
WEAKEN AND BECOME OVERTAKEN BY HIGHER FREQUENCY SOUTHERLY WAVES
SATURDAY.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 2 PM THURSDAY...MAIN FORECAST CHALLENGE WILL BE WIND
DIRECTIONS EARLY IN THE PERIOD AS A COASTAL FRONT WILL BE MEANDERING
SOMEWHERE IN THE AREA. VIA HPC GRAPHICS...START OUT THE PERIOD WITH
SOUTH TO SOUTHEAST WINDS QUICKLY BACKING TO NORTHEAST BY THE EARLY
AFTERNOON SUNDAY AS LOW PRESSURE MOVES OFFSHORE AND UP THE COAST.
NORTH TO NORTHWEST WINDS FROM LATE SUNDAY ON WITH SPEEDS GENERALLY
AROUND 15 KNOTS. A SECONDARY SHORTWAVE IN THE NORTHWEST FLOW ALOFT
WILL INCREASE WINDS SLIGHTLY LATE TUESDAY. WAVEWATCH SEAS LOOK GOOD
WITH 3-5 FEET EARLY DECREASING TO 2-4 FEET MONDAY AND TUESDAY WITH
THE OFFSHORE FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/TRA
SHORT TERM...SRP
LONG TERM...SHK
AVIATION...TRA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
133 PM EDT FRI APR 20 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA LATE THIS AFTERNOON AND
EVENING. A RIDGE OF HIGH PRESSURE WILL TRY TO BUILD INTO THE AREA
SATURDAY NIGHT AND THEN WEAKEN SUNDAY. A SURFACE LOW AND UPPER LOW WILL
MOVE SOUTH TO NORTH OVER THE EASTERN UNITED STATES EARLY NEXT WEEK
AND THIS WILL AFFECT THE WEATHER ESPECIALLY OVER NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST IN REASONABLE SHAPE THIS AFTERNOON WITH INCREASING MID
AND HIGH CLOUDS ACROSS THE AREA. CU DEVELOPING ACROSS SOUTHERN
OHIO AND EXPECTING CU FIELD TO CONTINUE EXPANDING NORTHWARD. LINE
OF RAINFALL ALONG THE FRONT WELL TO THE WEST HAS MADE LITTLE
PROGRESS DURING THE MORNING HOURS. WILL LEAVE POPS ALONG FOR THE
FAR WEST WITH INCREASING CHC POPS LATE AFTERNOON. EXPECTING MUCH OF
THE AREA TO REMAIN DRY THROUGH THE AFTERNOON AND EARLY EVENING
WITH EXCEPTION OF THE FAR WEST. TEMPS LOOK REASONABLE. PREVIOUS
DISCUSSION BELOW.
THE ISSUE FOR THIS AFTERNOON IS THE TIMING OF THE PRECIPITATION. THE
MODELS AND CURRENT CONDITIONS INDICATE THAT THE BEST CHANCE FOR
PRECIPITATION WILL BE VERY CLOSE TO THE FRONT AND BEHIND IT. THE
FRONT IS EXPECTED TO BE FROM TOL TO FDY AROUND 20Z...CLE TO MFD AT
00Z AND ERI TO YNG BY 03Z. THE HRRR MODEL IS TRYING TO INDICATE SOME
SHOWERS DEVELOPING WAY AHEAD OF THE FRONT. MOST OF THE MODELS ARE
NOT INDICATING THIS...SO PLAYED THE FORECAST THAT WAY. SPC HAS SOME
OF THE AREA IN SEE TEXT FOR POSSIBLE SEVERE THUNDERSTORMS. EXPECTING
A FAIR AMOUNT OF CUMULUS CLOUDS THIS AFTERNOON...WE SHOULD HAVE SOME
SUNSHINE TO HELP INCREASE THE CAPES TOO MUCH. WILL MENTION IN THE HWO
STRONG TO AN ISOLATED SEVERE THUNDERSTORM COULD BE POSSIBLE. THE
BEST CHANCE FOR THUNDERSTORMS WILL BE WITHIN A FEW HOURS OF
FRONTAL PASSAGE. WITH THE SOUTHWEST FLOW AND SOME SUNSHINE WENT
TOWARD THE WARMEST GUIDANCE. ATTM WITH NOT 100% SUNSHINE WE SHOULD
NOT BREAK ANY RECORDS...THE RECORD HIGHS FOR TODAY ARE IN THE
LOWER TO MID 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE GFS/ECMWF HANG UNTO THE SHOWERS MUCH LONGER THAN THE OTHER
MODELS. THIS SEEMS REASONABLE WITH A FAIR AMOUNT OF OMEGA AND THE
UPPER TROF MOVING THROUGH TONIGHT AND SATURDAY. HIGH PRESSURE
RIDGE TRIES TO BUILD IN SATURDAY NIGHT AND WEAKEN BY SUNDAY...SO
SATURDAY NIGHT AND SUNDAY SHOULD BE DRY. MAY HAVE TO WORRY ABOUT
SOME FROST SATURDAY NIGHT IF THE WINDS DECREASE ENOUGH AND THE
CLOUDS COVER IS NOT TOO THICK. THE BEST CHANCE FOR DECREASING
CLOUDS WILL BE NORTHWEST OHIO. WITH SOME UNCERTAINTY DID NOT
MENTION FROST ATTM IN THE GRIDS/ZONES...ONLY THE HWO.
SUNDAY NIGHT THROUGH MONDAY NIGHT ARE INTERESTING WITH THE SURFACE LOW
AND UPPER LOW MOVING SOUTH TO NORTH OVER THE EASTERN UNITED
STATES. INTRODUCING CHANCE POPS OVER THE EASTERN PORTION OF THE
FORECAST AREA AND WITH THE AIR COLD ENOUGH A CHANCE OF RAIN OR
SNOW. NORTHWEST OHIO SHOULD REMAIN MAINLY DRY FROM THE
SYSTEM...THIS WILL HAVE TO BE WATCHED.
TENDED ON THE COOLER SIDE FOR THE TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
A LOT OF UNCERTAINTY FROM TUESDAY ONWARD WITH THE FORECAST. TUESDAY
WILL DEPEND ON WHAT ENDS UP HAPPENING WITH THE EAST COAST LOW THAT
IS FORECAST TO CROSS NEW ENGLAND. HOW MUCH COLD/COOL AIR WILL BE
DRAWN SOUTHWARD WITH THIS. WITH A COUPLE RUNS WITH THIS GENERAL
SOLUTION HAVE LOWERED HIGH TEMPS ON TUESDAY AND WEDNESDAY AND THEY
WILL BE SITTING 5 TO 10 DEGREES BELOW NORMAL. THERE IS A LOT OF
SWING IN WHICH WAY THIS WILL TURN OUT. EVENTUALLY TOWARD MID WEEK WE
WILL BE IMPROVING AS WE START TO GET SOME RIDGING BUILD TOWARD THE
AREA.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THE COLD FRONT OVER EASTERN IN HAS MADE ONLY SLOW PROGRESS TODAY. A
BAND OF PRECIP REMAINS JUST TO THE WEST OF THE FRONT. NEW MODELS
SUGGEST THE FRONT WILL MAKE IT TO KTOL AND KFDY TOWARD 00Z WITH
PRECIP FOLLOWING SHORTLY AFTER. WILL TRY TO TIME THESE FEATURES
ACROSS THE REMAINDER OF THE AREA THIS EVENING. EXPECT CIGS TO DIP
TO MVFR AN HOUR OR TWO AFTER THE FROPA AND LIKELY TO IFR AN HOUR
OR TWO AFTER THAT. MUCH OF THE AREA WILL THEN REMAIN NO BETTER
THAN MVFR THROUGH THE END OF THE TAF PERIOD. IT IS POSSIBLE THAT
KTOL AND KFDY COULD JUMP TO VFR LATE. MOST AREAS SHOULD SEE A 4 TO
6 HOUR PERIOD OF MAINLY LIGHT PRECIP. THERE IS AN OUTSIDE SHOT FOR
SOME THUNDER IN NW OH BUT THE REMAINDER OF THE AREA WILL SEE JUST
RAIN. GUSTY SW FLOW WILL BECOME W AND THEN NW BEHIND THE FRONT.
SOME GUSTS TO 25 KNOTS POSSIBLE FOR SEVERAL HOURS BEHIND THE
FROPA.
.OUTLOOK...NON VFR LIKELY FRIDAY NIGHT INTO SATURDAY MORNING AND
AGAIN FOR THE EAST MONDAY INTO TUESDAY.
&&
.MARINE...
COLD FRONT TO COME ACROSS THE LAKE THIS EVENING. SOUTHERLY FLOW
ACROSS A STABLE LAKE WILL KEEP CONDITIONS BELOW SMALL CRAFT CRITERIA
FOR TODAY. ENOUGH POST-FRONTAL WIND TO MAKE FOR A CHOPPY NEARSHORE
LATE TONIGHT THROUGH SATURDAY MORNING...AND A SMALL CRAFT ADV WILL
LIKELY BE NEEDED THEN. HIGH PRESSURE THEN SETTLES OVER THE NORTHERN
PLAINS/WESTERN LAKES INTO EARLY NEXT WEEK WHILE AN EAST COAST LOW
TRACKS TOWARD AND ACROSS NEW ENGLAND. THIS WILL AT LEAST TIGHTEN UP
THE GRADIENT AND WILL LIKELY HAVE ANOTHER PERIOD OF SMALL CRAFT
CONDITIONS FROM MONDAY INTO TUESDAY. NORTHERLY FLOW THIS WEEKEND AND
DEPENDING ON TRACK OF THE EAST COAST LOW...POSSIBLY BACKING TO
NORTHWEST FOR EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...ABE/KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...OUDEMAN
AVIATION...KUBINA
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1256 PM EDT FRI APR 20 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA LATE THIS AFTERNOON AND
EVENING. A RIDGE OF HIGH PRESSURE WILL TRY TO BUILD INTO THE AREA
SATURDAY NIGHT AND THEN WEAKEN SUNDAY. A SURFACE LOW AND UPPER LOW WILL
MOVE SOUTH TO NORTH OVER THE EASTERN UNITED STATES EARLY NEXT WEEK
AND THIS WILL AFFECT THE WEATHER ESPECIALLY OVER NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST IN REASONABLE SHAPE THIS AFTERNOON WITH INCREASING MID
AND HIGH CLOUDS ACROSS THE AREA. CU DEVELOPING ACROSS SOUTHERN
OHIO AND EXPECTING CU FIELD TO CONTINUE EXPANDING NORTHWARD. LINE
OF RAINFALL ALONG THE FRONT WELL TO THE WEST HAS MADE LITTLE
PROGRESS DURING THE MORNING HOURS. WILL LEAVE POPS ALONG FOR THE
FAR WEST WITH INCREASING CHC POPS LATE AFTERNOON. EXPECTING MUCH OF
THE AREA TO REMAIN DRY THROUGH THE AFTERNOON AND EARLY EVENING
WITH EXCEPTION OF THE FAR WEST. TEMPS LOOK REASONABLE. PREVIOUS
DISCUSSION BELOW.
THE ISSUE FOR THIS AFTERNOON IS THE TIMING OF THE PRECIPITATION. THE
MODELS AND CURRENT CONDITIONS INDICATE THAT THE BEST CHANCE FOR
PRECIPITATION WILL BE VERY CLOSE TO THE FRONT AND BEHIND IT. THE
FRONT IS EXPECTED TO BE FROM TOL TO FDY AROUND 20Z...CLE TO MFD AT
00Z AND ERI TO YNG BY 03Z. THE HRRR MODEL IS TRYING TO INDICATE SOME
SHOWERS DEVELOPING WAY AHEAD OF THE FRONT. MOST OF THE MODELS ARE
NOT INDICATING THIS...SO PLAYED THE FORECAST THAT WAY. SPC HAS SOME
OF THE AREA IN SEE TEXT FOR POSSIBLE SEVERE THUNDERSTORMS. EXPECTING
A FAIR AMOUNT OF CUMULUS CLOUDS THIS AFTERNOON...WE SHOULD HAVE SOME
SUNSHINE TO HELP INCREASE THE CAPES TOO MUCH. WILL MENTION IN THE HWO
STRONG TO AN ISOLATED SEVERE THUNDERSTORM COULD BE POSSIBLE. THE
BEST CHANCE FOR THUNDERSTORMS WILL BE WITHIN A FEW HOURS OF
FRONTAL PASSAGE. WITH THE SOUTHWEST FLOW AND SOME SUNSHINE WENT
TOWARD THE WARMEST GUIDANCE. ATTM WITH NOT 100% SUNSHINE WE SHOULD
NOT BREAK ANY RECORDS...THE RECORD HIGHS FOR TODAY ARE IN THE
LOWER TO MID 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE GFS/ECMWF HANG UNTO THE SHOWERS MUCH LONGER THAN THE OTHER
MODELS. THIS SEEMS REASONABLE WITH A FAIR AMOUNT OF OMEGA AND THE
UPPER TROF MOVING THROUGH TONIGHT AND SATURDAY. HIGH PRESSURE
RIDGE TRIES TO BUILD IN SATURDAY NIGHT AND WEAKEN BY SUNDAY...SO
SATURDAY NIGHT AND SUNDAY SHOULD BE DRY. MAY HAVE TO WORRY ABOUT
SOME FROST SATURDAY NIGHT IF THE WINDS DECREASE ENOUGH AND THE
CLOUDS COVER IS NOT TOO THICK. THE BEST CHANCE FOR DECREASING
CLOUDS WILL BE NORTHWEST OHIO. WITH SOME UNCERTAINTY DID NOT
MENTION FROST ATTM IN THE GRIDS/ZONES...ONLY THE HWO.
SUNDAY NIGHT THROUGH MONDAY NIGHT ARE INTERESTING WITH THE SURFACE LOW
AND UPPER LOW MOVING SOUTH TO NORTH OVER THE EASTERN UNITED
STATES. INTRODUCING CHANCE POPS OVER THE EASTERN PORTION OF THE
FORECAST AREA AND WITH THE AIR COLD ENOUGH A CHANCE OF RAIN OR
SNOW. NORTHWEST OHIO SHOULD REMAIN MAINLY DRY FROM THE
SYSTEM...THIS WILL HAVE TO BE WATCHED.
TENDED ON THE COOLER SIDE FOR THE TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
A LOT OF UNCERTAINTY FROM TUESDAY ONWARD WITH THE FORECAST. TUESDAY
WILL DEPEND ON WHAT ENDS UP HAPPENING WITH THE EAST COAST LOW THAT
IS FORECAST TO CROSS NEW ENGLAND. HOW MUCH COLD/COOL AIR WILL BE
DRAWN SOUTHWARD WITH THIS. WITH A COUPLE RUNS WITH THIS GENERAL
SOLUTION HAVE LOWERED HIGH TEMPS ON TUESDAY AND WEDNESDAY AND THEY
WILL BE SITTING 5 TO 10 DEGREES BELOW NORMAL. THERE IS A LOT OF
SWING IN WHICH WAY THIS WILL TURN OUT. EVENTUALLY TOWARD MID WEEK WE
WILL BE IMPROVING AS WE START TO GET SOME RIDGING BUILD TOWARD THE
AREA.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
VFR THROUGH DUSK WITH INTERVALS OF MID/HIGH CLOUDS. SHOULD
DEVELOP SOME 5K CU FOR THIS AFTERNOON. GUSTS WILL PICK UP LATE
MORNING AND WILL BE AROUND 25 KNOTS TODAY...WITH A FEW 30 KNOT
GUSTS POSSIBLE. THE THE BULK OF THE SHOWERS/RAIN WILL BE
IMMEDIATELY BEHIND THE FRONT TO CROSS THE AREA LATE THIS AFTERNOON
AND EVENING. THERE IS SOME CHANCE OF A FEW ISOLATED SHRA/TS
DEVELOPING AHEAD OF THE FRONT WEST OF CLE/MFD IN PEAK
HEATING...BUT FOCUSED TAFS ON THE MORE WIDESPREAD CONDITIONS
BEHIND THE FRONT. WILL HAVE TO WATCH THE TIMING OF THE FRONT AS IT
APPEARS THAT IT WILL BE SLOWING AS IT MOVES EAST. DEFINITE
MVFR...WITH GOOD CHANCES OF IFR TOO. EMBEDDED THUNDER ALSO
POSSIBLE AT LEAST INITIALLY/EARLY. RAIN WILL TAKE MOST OF THE
NIGHT TO GET THROUGH CLE AND INTO SATURDAY MORNING FURTHER EAST.
WINDS TO COME AROUND TO THE NORTH OVERNIGHT.
.OUTLOOK...NON VFR LIKELY FRIDAY NIGHT INTO SATURDAY MORNING AND
AGAIN FOR THE EAST MONDAY INTO TUESDAY.
&&
.MARINE...
COLD FRONT TO COME ACROSS THE LAKE THIS EVENING. SOUTHERLY FLOW
ACROSS A STABLE LAKE WILL KEEP CONDITIONS BELOW SMALL CRAFT CRITERIA
FOR TODAY. ENOUGH POST-FRONTAL WIND TO MAKE FOR A CHOPPY NEARSHORE
LATE TONIGHT THROUGH SATURDAY MORNING...AND A SMALL CRAFT ADV WILL
LIKELY BE NEEDED THEN. HIGH PRESSURE THEN SETTLES OVER THE NORTHERN
PLAINS/WESTERN LAKES INTO EARLY NEXT WEEK WHILE AN EAST COAST LOW
TRACKS TOWARD AND ACROSS NEW ENGLAND. THIS WILL AT LEAST TIGHTEN UP
THE GRADIENT AND WILL LIKELY HAVE ANOTHER PERIOD OF SMALL CRAFT
CONDITIONS FROM MONDAY INTO TUESDAY. NORTHERLY FLOW THIS WEEKEND AND
DEPENDING ON TRACK OF THE EAST COAST LOW...POSSIBLY BACKING TO
NORTHWEST FOR EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...ABE/KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
950 AM EDT FRI APR 20 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA LATE THIS AFTERNOON AND
EVENING. A RIDGE OF HIGH PRESSURE WILL TRY TO BUILD INTO THE AREA
SATURDAY NIGHT AND THEN WEAKEN SUNDAY. A SURFACE LOW AND UPPER LOW WILL
MOVE SOUTH TO NORTH OVER THE EASTERN UNITED STATES EARLY NEXT WEEK
AND THIS WILL AFFECT THE WEATHER ESPECIALLY OVER NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MADE ADJUSTMENTS TO SKY COVER THIS MORNING BASED ON SATELLITE
SHOWING JUST SOME THIN MID LEVEL CLOUDS ACROSS THE AREA. THICKER
CLOUD COVER CLOSER TO THE FRONT WITH THE PRECIP BACK IN
INDIANA/ILLINOIS THIS MORNING. CONTINUING TO EXPECT SOME CU TO
DEVELOP THIS AFTERNOON BUT LEANED MORE A BIT MORE SUNSHINE. LATEST
RUNS OF THE HRRR STILL TRYING TO SHOW SOME ISOLATED SHOWERS
EARLIER IN THE AFTERNOON FOR CENTRAL PORTIONS OF THE FORECAST AREA
BUT CONTINUED TO LEAN AGAINST THAT. INCREASED TEMPS SLIGHTLY
ESPECIALLY ACROSS THE EAST. KEPT LOCATIONS BELOW RECORDS BUT WILL
CONTINUE TO WATCH THIS. PREVIOUS DISCUSSION BELOW.
THE ISSUE FOR THIS AFTERNOON IS THE TIMING OF THE PRECIPITATION. THE
MODELS AND CURRENT CONDITIONS INDICATE THAT THE BEST CHANCE FOR
PRECIPITATION WILL BE VERY CLOSE TO THE FRONT AND BEHIND IT. THE
FRONT IS EXPECTED TO BE FROM TOL TO FDY AROUND 20Z...CLE TO MFD AT
00Z AND ERI TO YNG BY 03Z. THE HRRR MODEL IS TRYING TO INDICATE SOME
SHOWERS DEVELOPING WAY AHEAD OF THE FRONT. MOST OF THE MODELS ARE
NOT INDICATING THIS...SO PLAYED THE FORECAST THAT WAY. SPC HAS SOME
OF THE AREA IN SEE TEXT FOR POSSIBLE SEVERE THUNDERSTORMS. EXPECTING
A FAIR AMOUNT OF CUMULUS CLOUDS THIS AFTERNOON...WE SHOULD HAVE SOME
SUNSHINE TO HELP INCREASE THE CAPES TOO MUCH. WILL MENTION IN THE HWO
STRONG TO AN ISOLATED SEVERE THUNDERSTORM COULD BE POSSIBLE. THE
BEST CHANCE FOR THUNDERSTORMS WILL BE WITHIN A FEW HOURS OF
FRONTAL PASSAGE. WITH THE SOUTHWEST FLOW AND SOME SUNSHINE WENT
TOWARD THE WARMEST GUIDANCE. ATTM WITH NOT 100% SUNSHINE WE SHOULD
NOT BREAK ANY RECORDS...THE RECORD HIGHS FOR TODAY ARE IN THE
LOWER TO MID 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE GFS/ECMWF HANG UNTO THE SHOWERS MUCH LONGER THAN THE OTHER
MODELS. THIS SEEMS REASONABLE WITH A FAIR AMOUNT OF OMEGA AND THE
UPPER TROF MOVING THROUGH TONIGHT AND SATURDAY. HIGH PRESSURE
RIDGE TRIES TO BUILD IN SATURDAY NIGHT AND WEAKEN BY SUNDAY...SO
SATURDAY NIGHT AND SUNDAY SHOULD BE DRY. MAY HAVE TO WORRY ABOUT
SOME FROST SATURDAY NIGHT IF THE WINDS DECREASE ENOUGH AND THE
CLOUDS COVER IS NOT TOO THICK. THE BEST CHANCE FOR DECREASING
CLOUDS WILL BE NORTHWEST OHIO. WITH SOME UNCERTAINTY DID NOT
MENTION FROST ATTM IN THE GRIDS/ZONES...ONLY THE HWO.
SUNDAY NIGHT THROUGH MONDAY NIGHT ARE INTERESTING WITH THE SURFACE LOW
AND UPPER LOW MOVING SOUTH TO NORTH OVER THE EASTERN UNITED
STATES. INTRODUCING CHANCE POPS OVER THE EASTERN PORTION OF THE
FORECAST AREA AND WITH THE AIR COLD ENOUGH A CHANCE OF RAIN OR
SNOW. NORTHWEST OHIO SHOULD REMAIN MAINLY DRY FROM THE
SYSTEM...THIS WILL HAVE TO BE WATCHED.
TENDED ON THE COOLER SIDE FOR THE TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
A LOT OF UNCERTAINTY FROM TUESDAY ONWARD WITH THE FORECAST. TUESDAY
WILL DEPEND ON WHAT ENDS UP HAPPENING WITH THE EAST COAST LOW THAT
IS FORECAST TO CROSS NEW ENGLAND. HOW MUCH COLD/COOL AIR WILL BE
DRAWN SOUTHWARD WITH THIS. WITH A COUPLE RUNS WITH THIS GENERAL
SOLUTION HAVE LOWERED HIGH TEMPS ON TUESDAY AND WEDNESDAY AND THEY
WILL BE SITTING 5 TO 10 DEGREES BELOW NORMAL. THERE IS A LOT OF
SWING IN WHICH WAY THIS WILL TURN OUT. EVENTUALLY TOWARD MID WEEK WE
WILL BE IMPROVING AS WE START TO GET SOME RIDGING BUILD TOWARD THE
AREA.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH DUSK WITH INTERVALS OF MID/HIGH CLOUDS. SHOULD
DEVELOP SOME 5K CU FOR THIS AFTERNOON. GUSTS WILL PICK UP LATE
MORNING AND WILL BE AROUND 25 KNOTS TODAY...WITH A FEW 30 KNOT
GUSTS POSSIBLE. THE THE BULK OF THE SHOWERS/RAIN WILL BE
IMMEDIATELY BEHIND THE FRONT TO CROSS THE AREA LATE THIS AFTERNOON
AND EVENING. THERE IS SOME CHANCE OF A FEW ISOLATED SHRA/TS
DEVELOPING AHEAD OF THE FRONT WEST OF CLE/MFD IN PEAK
HEATING...BUT FOCUSED TAFS ON THE MORE WIDESPREAD CONDITIONS
BEHIND THE FRONT. WILL HAVE TO WATCH THE TIMING OF THE FRONT AS IT
APPEARS THAT IT WILL BE SLOWING AS IT MOVES EAST. DEFINITE
MVFR...WITH GOOD CHANCES OF IFR TOO. EMBEDDED THUNDER ALSO
POSSIBLE AT LEAST INITIALLY/EARLY. RAIN WILL TAKE MOST OF THE
NIGHT TO GET THROUGH CLE AND INTO SATURDAY MORNING FURTHER EAST.
WINDS TO COME AROUND TO THE NORTH OVERNIGHT.
.OUTLOOK...NON VFR LIKELY FRIDAY NIGHT INTO SATURDAY MORNING AND
AGAIN FOR THE EAST MONDAY INTO TUESDAY.
&&
.MARINE...
COLD FRONT TO COME ACROSS THE LAKE THIS EVENING. SOUTHERLY FLOW
ACROSS A STABLE LAKE WILL KEEP CONDITIONS BELOW SMALL CRAFT CRITERIA
FOR TODAY. ENOUGH POST-FRONTAL WIND TO MAKE FOR A CHOPPY NEARSHORE
LATE TONIGHT THROUGH SATURDAY MORNING...AND A SMALL CRAFT ADV WILL
LIKELY BE NEEDED THEN. HIGH PRESSURE THEN SETTLES OVER THE NORTHERN
PLAINS/WESTERN LAKES INTO EARLY NEXT WEEK WHILE AN EAST COAST LOW
TRACKS TOWARD AND ACROSS NEW ENGLAND. THIS WILL AT LEAST TIGHTEN UP
THE GRADIENT AND WILL LIKELY HAVE ANOTHER PERIOD OF SMALL CRAFT
CONDITIONS FROM MONDAY INTO TUESDAY. NORTHERLY FLOW THIS WEEKEND AND
DEPENDING ON TRACK OF THE EAST COAST LOW...POSSIBLY BACKING TO
NORTHWEST FOR EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...ABE/KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
711 AM EDT FRI APR 20 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA LATE THIS AFTERNOON AND
EVENING. A RIDGE OF HIGH PRESSURE WILL TRY TO BUILD INTO THE AREA
SATURDAY NIGHT AND THEN WEAKEN SUNDAY. A SURFACE LOW AND UPPER LOW WILL
MOVE SOUTH TO NORTH OVER THE EASTERN UNITED STATES EARLY NEXT WEEK
AND THIS WILL AFFECT THE WEATHER ESPECIALLY OVER NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONLY MADE MINOR ADJUSTMENTS TO THE SKY COVER GRIDS AND
TEMPERATURES. ANY THREAT OF SPRINKLES THE REMAINDER OF THE
MORNING WILL BE SMALL. OTHERWISE THE FORECAST SEEMS TO BE ON TARGET.
THE ISSUE FOR THIS AFTERNOON IS THE TIMING OF THE PRECIPITATION. THE
MODELS AND CURRENT CONDITIONS INDICATE THAT THE BEST CHANCE FOR
PRECIPITATION WILL BE VERY CLOSE TO THE FRONT AND BEHIND IT. THE
FRONT IS EXPECTED TO BE FROM TOL TO FDY AROUND 20Z...CLE TO MFD AT
00Z AND ERI TO YNG BY 03Z. THE HRRR MODEL IS TRYING TO INDICATE SOME
SHOWERS DEVELOPING WAY AHEAD OF THE FRONT. MOST OF THE MODELS ARE
NOT INDICATING THIS...SO PLAYED THE FORECAST THAT WAY. SPC HAS SOME
OF THE AREA IN SEE TEXT FOR POSSIBLE SEVERE THUNDERSTORMS. EXPECTING
A FAIR AMOUNT OF CUMULUS CLOUDS THIS AFTERNOON...WE SHOULD HAVE SOME
SUNSHINE TO HELP INCREASE THE CAPES TOO MUCH. WILL MENTION IN THE HWO
STRONG TO AN ISOLATED SEVERE THUNDERSTORM COULD BE POSSIBLE. THE
BEST CHANCE FOR THUNDERSTORMS WILL BE WITHIN A FEW HOURS OF
FRONTAL PASSAGE. WITH THE SOUTHWEST FLOW AND SOME SUNSHINE WENT
TOWARD THE WARMEST GUIDANCE. ATTM WITH NOT 100% SUNSHINE WE SHOULD
NOT BREAK ANY RECORDS...THE RECORD HIGHS FOR TODAY ARE IN THE
LOWER TO MID 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE GFS/ECMWF HANG UNTO THE SHOWERS MUCH LONGER THAN THE OTHER
MODELS. THIS SEEMS REASONABLE WITH A FAIR AMOUNT OF OMEGA AND THE
UPPER TROF MOVING THROUGH TONIGHT AND SATURDAY. HIGH PRESSURE
RIDGE TRIES TO BUILD IN SATURDAY NIGHT AND WEAKEN BY SUNDAY...SO
SATURDAY NIGHT AND SUNDAY SHOULD BE DRY. MAY HAVE TO WORRY ABOUT
SOME FROST SATURDAY NIGHT IF THE WINDS DECREASE ENOUGH AND THE
CLOUDS COVER IS NOT TOO THICK. THE BEST CHANCE FOR DECREASING
CLOUDS WILL BE NORTHWEST OHIO. WITH SOME UNCERTAINTY DID NOT
MENTION FROST ATTM IN THE GRIDS/ZONES...ONLY THE HWO.
SUNDAY NIGHT THROUGH MONDAY NIGHT ARE INTERESTING WITH THE SURFACE LOW
AND UPPER LOW MOVING SOUTH TO NORTH OVER THE EASTERN UNITED
STATES. INTRODUCING CHANCE POPS OVER THE EASTERN PORTION OF THE
FORECAST AREA AND WITH THE AIR COLD ENOUGH A CHANCE OF RAIN OR
SNOW. NORTHWEST OHIO SHOULD REMAIN MAINLY DRY FROM THE
SYSTEM...THIS WILL HAVE TO BE WATCHED.
TENDED ON THE COOLER SIDE FOR THE TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
A LOT OF UNCERTAINTY FROM TUESDAY ONWARD WITH THE FORECAST. TUESDAY
WILL DEPEND ON WHAT ENDS UP HAPPENING WITH THE EAST COAST LOW THAT
IS FORECAST TO CROSS NEW ENGLAND. HOW MUCH COLD/COOL AIR WILL BE
DRAWN SOUTHWARD WITH THIS. WITH A COUPLE RUNS WITH THIS GENERAL
SOLUTION HAVE LOWERED HIGH TEMPS ON TUESDAY AND WEDNESDAY AND THEY
WILL BE SITTING 5 TO 10 DEGREES BELOW NORMAL. THERE IS A LOT OF
SWING IN WHICH WAY THIS WILL TURN OUT. EVENTUALLY TOWARD MID WEEK WE
WILL BE IMPROVING AS WE START TO GET SOME RIDGING BUILD TOWARD THE
AREA.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH DUSK WITH INTERVALS OF MID/HIGH CLOUDS. SHOULD
DEVELOP SOME 5K CU FOR THIS AFTERNOON. GUSTS WILL PICK UP LATE
MORNING AND WILL BE AROUND 25 KNOTS TODAY...WITH A FEW 30 KNOT
GUSTS POSSIBLE. THE THE BULK OF THE SHOWERS/RAIN WILL BE
IMMEDIATELY BEHIND THE FRONT TO CROSS THE AREA LATE THIS AFTERNOON
AND EVENING. THERE IS SOME CHANCE OF A FEW ISOLATED SHRA/TS
DEVELOPING AHEAD OF THE FRONT WEST OF CLE/MFD IN PEAK
HEATING...BUT FOCUSED TAFS ON THE MORE WIDESPREAD CONDITIONS
BEHIND THE FRONT. WILL HAVE TO WATCH THE TIMING OF THE FRONT AS IT
APPEARS THAT IT WILL BE SLOWING AS IT MOVES EAST. DEFINITE
MVFR...WITH GOOD CHANCES OF IFR TOO. EMBEDDED THUNDER ALSO
POSSIBLE AT LEAST INITIALLY/EARLY. RAIN WILL TAKE MOST OF THE
NIGHT TO GET THROUGH CLE AND INTO SATURDAY MORNING FURTHER EAST.
WINDS TO COME AROUND TO THE NORTH OVERNIGHT.
.OUTLOOK...NON VFR LIKELY FRIDAY NIGHT INTO SATURDAY MORNING AND
AGAIN FOR THE EAST MONDAY INTO TUESDAY.
&&
.MARINE...
COLD FRONT TO COME ACROSS THE LAKE THIS EVENING. SOUTHERLY FLOW
ACROSS A STABLE LAKE WILL KEEP CONDITIONS BELOW SMALL CRAFT CRITERIA
FOR TODAY. ENOUGH POST-FRONTAL WIND TO MAKE FOR A CHOPPY NEARSHORE
LATE TONIGHT THROUGH SATURDAY MORNING...AND A SMALL CRAFT ADV WILL
LIKELY BE NEEDED THEN. HIGH PRESSURE THEN SETTLES OVER THE NORTHERN
PLAINS/WESTERN LAKES INTO EARLY NEXT WEEK WHILE AN EAST COAST LOW
TRACKS TOWARD AND ACROSS NEW ENGLAND. THIS WILL AT LEAST TIGHTEN UP
THE GRADIENT AND WILL LIKELY HAVE ANOTHER PERIOD OF SMALL CRAFT
CONDITIONS FROM MONDAY INTO TUESDAY. NORTHERLY FLOW THIS WEEKEND AND
DEPENDING ON TRACK OF THE EAST COAST LOW...POSSIBLY BACKING TO
NORTHWEST FOR EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
649 AM EDT FRI APR 20 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA LATE THIS AFTERNOON AND
EVENING. A RIDGE OF HIGH PRESSURE WILL TRY TO BUILD INTO THE AREA
SATURDAY NIGHT AND THEN WEAKEN SUNDAY. A SURFACE LOW AND UPPER LOW WILL
MOVE SOUTH TO NORTH OVER THE EASTERN UNITED STATES EARLY NEXT WEEK
AND THIS WILL AFFECT THE WEATHER ESPECIALLY OVER NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONLY MADE MINOR ADJUSTMENTS TO THE SKY COVER GRIDS AND
TEMPERATURES. ANY THREAT OF SPRINKLES THE REMAINDER OF THE
MORNING WILL BE SMALL. OTHERWISE THE FORECAST SEEMS TO BE ON TARGET.
THE ISSUE FOR THIS AFTERNOON IS THE TIMING OF THE PRECIPITATION. THE
MODELS AND CURRENT CONDITIONS INDICATE THAT THE BEST CHANCE FOR
PRECIPITATION WILL BE VERY CLOSE TO THE FRONT AND BEHIND IT. THE
FRONT IS EXPECTED TO BE FROM TOL TO FDY AROUND 20Z...CLE TO MFD AT
00Z AND ERI TO YNG BY 03Z. THE HRRR MODEL IS TRYING TO INDICATE SOME
SHOWERS DEVELOPING WAY AHEAD OF THE FRONT. MOST OF THE MODELS ARE
NOT INDICATING THIS...SO PLAYED THE FORECAST THAT WAY. SPC HAS SOME
OF THE AREA IN SEE TEXT FOR POSSIBLE SEVERE THUNDERSTORMS. EXPECTING
A FAIR AMOUNT OF CUMULUS CLOUDS THIS AFTERNOON...WE SHOULD HAVE SOME
SUNSHINE TO HELP INCREASE THE CAPES TOO MUCH. WILL MENTION IN THE HWO
STRONG TO AN ISOLATED SEVERE THUNDERSTORM COULD BE POSSIBLE. THE
BEST CHANCE FOR THUNDERSTORMS WILL BE WITHIN A FEW HOURS OF
FRONTAL PASSAGE. WITH THE SOUTHWEST FLOW AND SOME SUNSHINE WENT
TOWARD THE WARMEST GUIDANCE. ATTM WITH NOT 100% SUNSHINE WE SHOULD
NOT BREAK ANY RECORDS...THE RECORD HIGHS FOR TODAY ARE IN THE
LOWER TO MID 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE GFS/ECMWF HANG UNTO THE SHOWERS MUCH LONGER THAN THE OTHER
MODELS. THIS SEEMS REASONABLE WITH A FAIR AMOUNT OF OMEGA AND THE
UPPER TROF MOVING THROUGH TONIGHT AND SATURDAY. HIGH PRESSURE
RIDGE TRIES TO BUILD IN SATURDAY NIGHT AND WEAKEN BY SUNDAY...SO
SATURDAY NIGHT AND SUNDAY SHOULD BE DRY. MAY HAVE TO WORRY ABOUT
SOME FROST SATURDAY NIGHT IF THE WINDS DECREASE ENOUGH AND THE
CLOUDS COVER IS NOT TOO THICK. THE BEST CHANCE FOR DECREASING
CLOUDS WILL BE NORTHWEST OHIO. WITH SOME UNCERTAINTY DID NOT
MENTION FROST ATTM IN THE GRIDS/ZONES...ONLY THE HWO.
SUNDAY NIGHT THROUGH MONDAY NIGHT ARE INTERESTING WITH THE SURFACE LOW
AND UPPER LOW MOVING SOUTH TO NORTH OVER THE EASTERN UNITED
STATES. INTRODUCING CHANCE POPS OVER THE EASTERN PORTION OF THE
FORECAST AREA AND WITH THE AIR COLD ENOUGH A CHANCE OF RAIN OR
SNOW. NORTHWEST OHIO SHOULD REMAIN MAINLY DRY FROM THE
SYSTEM...THIS WILL HAVE TO BE WATCHED.
TENDED ON THE COOLER SIDE FOR THE TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
A LOT OF UNCERTAINTY FROM TUESDAY ONWARD WITH THE FORECAST. TUESDAY
WILL DEPEND ON WHAT ENDS UP HAPPENING WITH THE EAST COAST LOW THAT
IS FORECAST TO CROSS NEW ENGLAND. HOW MUCH COLD/COOL AIR WILL BE
DRAWN SOUTHWARD WITH THIS. WITH A COUPLE RUNS WITH THIS GENERAL
SOLUTION HAVE LOWERED HIGH TEMPS ON TUESDAY AND WEDNESDAY AND THEY
WILL BE SITTING 5 TO 10 DEGREES BELOW NORMAL. THERE IS A LOT OF
SWING IN WHICH WAY THIS WILL TURN OUT. EVENTUALLY TOWARD MID WEEK WE
WILL BE IMPROVING AS WE START TO GET SOME RIDGING BUILD TOWARD THE
AREA.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH THE FIRST HALF OF THE TAF WITH INTERVALS OF MID/HIGH
CLOUDS. SHOULD DEVELOP SOME 5K CU FOR THIS AFTERNOON. GUSTS WILL
PICK UP LATE MORNING AND WILL BE AROUND 25 KNOTS TODAY...WITH A
FEW 30 KNOT GUSTS POSSIBLE. THE THE BULK OF THE SHOWERS/RAIN WILL
BE IMMEDIATELY BEHIND THE FRONT TO CROSS THE AREA LATE THIS
AFTERNOON AND EVENING. THERE IS SOME CHANCE OF A FEW
ISOLATED/SCATTERED SHRA/TS DEVELOPING AHEAD OF THE FRONT WEST OF
CLE/MFD IN PEAK HEATING...BUT FOCUSED TAFS ON THE MORE WIDESPREAD
CONDITIONS BEHIND THE FRONT. DEFINITE MVFR...WITH GOOD CHANCES OF
IFR TOO. EMBEDDED THUNDER ALSO POSSIBLE AT LEAST INITIALLY/EARLY.
FRONT SLOWS WITH TIME AND RAIN WILL TAKE MOST OF THE NIGHT TO GET
THROUGH CLE AND INTO SATURDAY MORNING FURTHER EAST.
.OUTLOOK...NON VFR LIKELY FRIDAY NIGHT INTO SATURDAY MORNING AND
AGAIN FOR THE EAST MONDAY INTO TUESDAY.
&&
.MARINE...
COLD FRONT TO COME ACROSS THE LAKE THIS EVENING. SOUTHERLY FLOW
ACROSS A STABLE LAKE WILL KEEP CONDITIONS BELOW SMALL CRAFT CRITERIA
FOR TODAY. ENOUGH POST-FRONTAL WIND TO MAKE FOR A CHOPPY NEARSHORE
LATE TONIGHT THROUGH SATURDAY MORNING...AND A SMALL CRAFT ADV WILL
LIKELY BE NEEDED THEN. HIGH PRESSURE THEN SETTLES OVER THE NORTHERN
PLAINS/WESTERN LAKES INTO EARLY NEXT WEEK WHILE AN EAST COAST LOW
TRACKS TOWARD AND ACROSS NEW ENGLAND. THIS WILL AT LEAST TIGHTEN UP
THE GRADIENT AND WILL LIKELY HAVE ANOTHER PERIOD OF SMALL CRAFT
CONDITIONS FROM MONDAY INTO TUESDAY. NORTHERLY FLOW THIS WEEKEND AND
DEPENDING ON TRACK OF THE EAST COAST LOW...POSSIBLY BACKING TO
NORTHWEST FOR EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
643 AM EDT FRI APR 20 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA LATE THIS AFTERNOON AND
EVENING. A RIDGE OF HIGH PRESSURE WILL TRY TO BUILD INTO THE AREA
SATURDAY NIGHT AND THEN WEAKEN SUNDAY. A SURFACE LOW AND UPPER LOW WILL
MOVE SOUTH TO NORTH OVER THE EASTERN UNITED STATES EARLY NEXT WEEK
AND THIS WILL AFFECT THE WEATHER ESPECIALLY OVER NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONLY MADE MINOR ADJUSTMENTS TO THE SKY COVER GRIDS AND
TEMPERATURES. ANY THREAT OF SPRINKLES THE REMAINDER OF THE
MORNING WILL BE SMALL. OTHERWISE THE FORECAST SEEMS TO BE ON TARGET.
THE ISSUE FOR THIS AFTERNOON IS THE TIMING OF THE PRECIPITATION. THE
MODELS AND CURRENT CONDITIONS INDICATE THAT THE BEST CHANCE FOR
PRECIPITATION WILL BE VERY CLOSE TO THE FRONT AND BEHIND IT. THE
FRONT IS EXPECTED TO BE FROM TOL TO FDY AROUND 20Z...CLE TO MFD AT
00Z AND ERI TO YNG BY 03Z. THE HRRR MODEL IS TRYING TO INDICATE SOME
SHOWERS DEVELOPING WAY AHEAD OF THE FRONT. MOST OF THE MODELS ARE
NOT INDICATING THIS...SO PLAYED THE FORECAST THAT WAY. SPC HAS SOME
OF THE AREA IN SEE TEXT FOR POSSIBLE SEVERE THUNDERSTORMS. EXPECTING
A FAIR AMOUNT OF CUMULUS CLOUDS THIS AFTERNOON...WE SHOULD HAVE SOME
SUNSHINE TO HELP INCREASE THE CAPES TOO MUCH. WILL MENTION IN THE HWO
STRONG TO AN ISOLATED SEVERE THUNDERSTORM COULD BE POSSIBLE. THE
BEST CHANCE FOR THUNDERSTORMS WILL BE WITHIN A FEW HOURS OF
FRONTAL PASSAGE. WITH THE SOUTHWEST FLOW AND SOME SUNSHINE WENT
TOWARD THE WARMEST GUIDANCE. ATTM WITH NOT 100% SUNSHINE WE SHOULD
NOT BREAK ANY RECORDS...THE RECORD HIGHS FOR TODAY ARE IN THE
LOWER TO MID 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE GFS/ECMWF HANG UNTO THE SHOWERS MUCH LONGER THAN THE OTHER
MODELS. THIS SEEMS REASONABLE WITH A FAIR AMOUNT OF OMEGA AND THE
UPPER TROF MOVING THROUGH TONIGHT AND SATURDAY. HIGH PRESSURE
RIDGE TRIES TO BUILD IN SATURDAY NIGHT AND WEAKEN BY SUNDAY...SO
SATURDAY NIGHT AND SUNDAY SHOULD BE DRY. MAY HAVE TO WORRY ABOUT
SOME FROST SATURDAY NIGHT IF THE WINDS DECREASE ENOUGH AS THE
CLOUDS WILL DECREASE.
SUNDAY NIGHT THROUGH MONDAY NIGHT ARE INTERESTING WITH THE SURFACE LOW
AND UPPER LOW MOVING SOUTH TO NORTH OVER THE EASTERN UNITED
STATES. INTRODUCING CHANCE POPS OVER THE EASTERN PORTION OF THE
FORECAST AREA AND WITH THE AIR COLD ENOUGH A CHANCE OF RAIN OR
SNOW. NORTHWEST OHIO SHOULD REMAIN MAINLY DRY FROM THE
SYSTEM...THIS WILL HAVE TO BE WATCHED.
TENDED ON THE COOLER SIDE FOR THE TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
A LOT OF UNCERTAINTY FROM TUESDAY ONWARD WITH THE FORECAST. TUESDAY
WILL DEPEND ON WHAT ENDS UP HAPPENING WITH THE EAST COAST LOW THAT
IS FORECAST TO CROSS NEW ENGLAND. HOW MUCH COLD/COOL AIR WILL BE
DRAWN SOUTHWARD WITH THIS. WITH A COUPLE RUNS WITH THIS GENERAL
SOLUTION HAVE LOWERED HIGH TEMPS ON TUESDAY AND WEDNESDAY AND THEY
WILL BE SITTING 5 TO 10 DEGREES BELOW NORMAL. THERE IS A LOT OF
SWING IN WHICH WAY THIS WILL TURN OUT. EVENTUALLY TOWARD MID WEEK WE
WILL BE IMPROVING AS WE START TO GET SOME RIDGING BUILD TOWARD THE
AREA.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH THE FIRST HALF OF THE TAF WITH INTERVALS OF MID/HIGH
CLOUDS. SHOULD DEVELOP SOME 5K CU FOR THIS AFTERNOON. GUSTS WILL
PICK UP LATE MORNING AND WILL BE AROUND 25 KNOTS TODAY...WITH A
FEW 30 KNOT GUSTS POSSIBLE. THE THE BULK OF THE SHOWERS/RAIN WILL
BE IMMEDIATELY BEHIND THE FRONT TO CROSS THE AREA LATE THIS
AFTERNOON AND EVENING. THERE IS SOME CHANCE OF A FEW
ISOLATED/SCATTERED SHRA/TS DEVELOPING AHEAD OF THE FRONT WEST OF
CLE/MFD IN PEAK HEATING...BUT FOCUSED TAFS ON THE MORE WIDESPREAD
CONDITIONS BEHIND THE FRONT. DEFINITE MVFR...WITH GOOD CHANCES OF
IFR TOO. EMBEDDED THUNDER ALSO POSSIBLE AT LEAST INITIALLY/EARLY.
FRONT SLOWS WITH TIME AND RAIN WILL TAKE MOST OF THE NIGHT TO GET
THROUGH CLE AND INTO SATURDAY MORNING FURTHER EAST.
.OUTLOOK...NON VFR LIKELY FRIDAY NIGHT INTO SATURDAY MORNING AND
AGAIN FOR THE EAST MONDAY INTO TUESDAY.
&&
.MARINE...
COLD FRONT TO COME ACROSS THE LAKE THIS EVENING. SOUTHERLY FLOW
ACROSS A STABLE LAKE WILL KEEP CONDITIONS BELOW SMALL CRAFT CRITERIA
FOR TODAY. ENOUGH POST-FRONTAL WIND TO MAKE FOR A CHOPPY NEARSHORE
LATE TONIGHT THROUGH SATURDAY MORNING...AND A SMALL CRAFT ADV WILL
LIKELY BE NEEDED THEN. HIGH PRESSURE THEN SETTLES OVER THE NORTHERN
PLAINS/WESTERN LAKES INTO EARLY NEXT WEEK WHILE AN EAST COAST LOW
TRACKS TOWARD AND ACROSS NEW ENGLAND. THIS WILL AT LEAST TIGHTEN UP
THE GRADIENT AND WILL LIKELY HAVE ANOTHER PERIOD OF SMALL CRAFT
CONDITIONS FROM MONDAY INTO TUESDAY. NORTHERLY FLOW THIS WEEKEND AND
DEPENDING ON TRACK OF THE EAST COAST LOW...POSSIBLY BACKING TO
NORTHWEST FOR EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
406 AM EDT FRI APR 20 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA LATE THIS AFTERNOON AND
EVENING. A RIDGE OF HIGH PRESSURE WILL TRY TO BUILD INTO THE AREA
SATURDAY NIGHT AND THEN WEAKEN SUNDAY. A SURFACE LOW AND UPPER LOW WILL
MOVE SOUTH TO NORTH OVER THE EASTERN UNITED STATES EARLY NEXT WEEK
AND THIS WILL AFFECT THE WEATHER ESPECIALLY OVER NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE SPRINKLES THAT ARE OVER NORTHWEST OHIO AND NORTH OF LAKE ERIE ARE
DECREASING AS THEY MOVE EAST. WILL NOT MENTION THEM IN THE
ZONES/GRIDS. WILL ISSUE A NOWCAST AS NEEDED.
THE ISSUE FOR THIS AFTERNOON IS THE TIMING OF THE PRECIPITATION. THE
MODELS AND CURRENT CONDITIONS INDICATE THAT THE BEST CHANCE FOR
PRECIPITATION WILL BE VERY CLOSE TO THE FRONT AND BEHIND IT. THE
FRONT IS EXPECTED TO BE FROM TOL TO FDY AROUND 20Z...CLE TO MFD AT
00Z AND ERI TO YNG BY 03Z. THE HRRR MODEL IS TRYING TO INDICATE SOME
SHOWERS DEVELOPING WAY AHEAD OF THE FRONT. MOST OF THE MODELS ARE
NOT INDICATING THIS...SO PLAYED THE FORECAST THAT WAY. SPC HAS SOME
OF THE AREA IN SEE TEXT FOR POSSIBLE SEVERE THUNDERSTORMS. EXPECTING
A FAIR AMOUNT OF CUMULUS CLOUDS THIS AFTERNOON...WE SHOULD HAVE SOME
SUNSHINE TO HELP INCREASE THE CAPES TOO MUCH. WILL MENTION IN THE HWO
STRONG TO AN ISOLATED SEVERE THUNDERSTORM COULD BE POSSIBLE. THE
BEST CHANCE FOR THUNDERSTORMS WILL BE WITHIN A FEW HOURS OF
FRONTAL PASSAGE. WITH THE SOUTHWEST FLOW AND SOME SUNSHINE WENT
TOWARD THE WARMEST GUIDANCE. ATTM WITH NOT 100% SUNSHINE WE SHOULD
NOT BREAK ANY RECORDS...THE RECORD HIGHS FOR TODAY ARE IN THE
LOWER TO MID 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THE GFS/ECMWF HANG UNTO THE SHOWERS MUCH LONGER THAN THE OTHER
MODELS. THIS SEEMS REASONABLE WITH A FAIR AMOUNT OF OMEGA AND THE
UPPER TROF MOVING THROUGH TONIGHT AND SATURDAY. HIGH PRESSURE
RIDGE TRIES TO BUILD IN SATURDAY NIGHT AND WEAKEN BY SUNDAY...SO
SATURDAY NIGHT AND SUNDAY SHOULD BE DRY. MAY HAVE TO WORRY ABOUT
SOME FROST SATURDAY NIGHT IF THE WINDS DECREASE ENOUGH AS THE
CLOUDS WILL DECREASE.
SUNDAY NIGHT THROUGH MONDAY NIGHT ARE INTERESTING WITH THE SURFACE LOW
AND UPPER LOW MOVING SOUTH TO NORTH OVER THE EASTERN UNITED
STATES. INTRODUCING CHANCE POPS OVER THE EASTERN PORTION OF THE
FORECAST AREA AND WITH THE AIR COLD ENOUGH A CHANCE OF RAIN OR
SNOW. NORTHWEST OHIO SHOULD REMAIN MAINLY DRY FROM THE
SYSTEM...THIS WILL HAVE TO BE WATCHED.
TENDED ON THE COOLER SIDE FOR THE TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
A LOT OF UNCERTAINTY FROM TUESDAY ONWARD WITH THE FORECAST. TUESDAY
WILL DEPEND ON WHAT ENDS UP HAPPENING WITH THE EAST COAST LOW THAT
IS FORECAST TO CROSS NEW ENGLAND. HOW MUCH COLD/COOL AIR WILL BE
DRAWN SOUTHWARD WITH THIS. WITH A COUPLE RUNS WITH THIS GENERAL
SOLUTION HAVE LOWERED HIGH TEMPS ON TUESDAY AND WEDNESDAY AND THEY
WILL BE SITTING 5 TO 10 DEGREES BELOW NORMAL. THERE IS A LOT OF
SWING IN WHICH WAY THIS WILL TURN OUT. EVENTUALLY TOWARD MID WEEK WE
WILL BE IMPROVING AS WE START TO GET SOME RIDGING BUILD TOWARD THE
AREA.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
VFR THROUGH THE FIRST HALF OF THE TAF WITH INTERVALS OF MID/HIGH
CLOUDS. SHOULD DEVELOP SOME 5K CU FOR THIS AFTERNOON. GUSTS WILL
PICK UP LATE MORNING AND WILL BE AROUND 25 KNOTS TODAY...WITH A
FEW 30 KNOT GUSTS POSSIBLE. THE THE BULK OF THE SHOWERS/RAIN WILL
BE IMMEDIATELY BEHIND THE FRONT TO CROSS THE AREA LATE THIS
AFTERNOON AND EVENING. THERE IS SOME CHANCE OF A FEW
ISOLATED/SCATTERED SHRA/TS DEVELOPING AHEAD OF THE FRONT WEST OF
CLE/MFD IN PEAK HEATING...BUT FOCUSED TAFS ON THE MORE WIDESPREAD
CONDITIONS BEHIND THE FRONT. DEFINITE MVFR...WITH GOOD CHANCES OF
IFR TOO. EMBEDDED THUNDER ALSO POSSIBLE AT LEAST INITIALLY/EARLY.
FRONT SLOWS WITH TIME AND RAIN WILL TAKE MOST OF THE NIGHT TO GET
THROUGH CLE AND INTO SATURDAY MORNING FURTHER EAST.
.OUTLOOK...NON VFR LIKELY FRIDAY NIGHT INTO SATURDAY MORNING AND
AGAIN FOR THE EAST MONDAY INTO TUESDAY.
&&
.MARINE...
COLD FRONT TO COME ACROSS THE LAKE THIS EVENING. SOUTHERLY FLOW
ACROSS A STABLE LAKE WILL KEEP CONDITIONS BELOW SMALL CRAFT CRITERIA
FOR TODAY. ENOUGH POST-FRONTAL WIND TO MAKE FOR A CHOPPY NEARSHORE
LATE TONIGHT THROUGH SATURDAY MORNING...AND A SMALL CRAFT ADV WILL
LIKELY BE NEEDED THEN. HIGH PRESSURE THEN SETTLES OVER THE NORTHERN
PLAINS/WESTERN LAKES INTO EARLY NEXT WEEK WHILE AN EAST COAST LOW
TRACKS TOWARD AND ACROSS NEW ENGLAND. THIS WILL AT LEAST TIGHTEN UP
THE GRADIENT AND WILL LIKELY HAVE ANOTHER PERIOD OF SMALL CRAFT
CONDITIONS FROM MONDAY INTO TUESDAY. NORTHERLY FLOW THIS WEEKEND AND
DEPENDING ON TRACK OF THE EAST COAST LOW...POSSIBLY BACKING TO
NORTHWEST FOR EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...OUDEMAN
AVIATION...OUDEMAN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
125 PM CDT FRI APR 20 2012
.DISCUSSION...NOTE AVIATION DISCUSSION BELOW.
&&
.AVIATION...COMBINATION OF MVFR/VFR CEILINGS ANTICIPATED IN
ADVANCE OF A COLD FRONT EXPECTED TO MOVE ACRS SOUTH TEXAS THIS
AFTN AND OFFSHORE BY EVENING/EARLY TONIGHT. IN ADVANCE OF/ALONG
FRONT...ISOLD/SCT IFR CONDITIONS EXPECTED NEAR/DRG SHOWER/
THUNDERSTORM ACTIVITY. VFR CONDITIONS ARE EXPECTED AFTER AROUND
02Z OVER LAND WITH MODERATE NORTH/NORTHEAST WIND. EXPECT WIND TO
BECOME LGT OVER LAND BY 06Z SAT...YET INCREASE TO MODERATE/BREEZY
OVER LAND GENERALLY EAST OF US281 BY MID MORNING SAT.
&&
.PREV DISCUSSION... /ISSUED 627 AM CDT FRI APR 20 2012/
DISCUSSION...UPDATED FOR 12Z AVIATION.
AVIATION...CLOUDS WILL BEGIN TO BUILD IN THIS MORNING AHEAD OF AN
APPROACHING COLD FRONT. THIS FRONT WILL PUSH THROUGH THE TAF SITES
THIS AFTERNOON WITH THUNDERSTORM CHANCES JUST AHEAD OF AND ALONG
THE FRONT. SOME STORMS...ESPECIALLY FOR EASTERN SITES MAY BE
SEVERE THIS EVENING. GUSTY NORTHERLY WINDS ARE EXPECTED TO DEVELOP
BEHIND THE FRONT AND LINGER OVERNIGHT. VFR CONDITIONS WILL RETURN
FOR SATURDAY.
PREV DISCUSSION... /ISSUED 416 AM CDT FRI APR 20 2012/
SHORT TERM (TODAY THROUGH SATURDAY)...MAIN FORECAST CONCERN IS
WITH THUNDER AND SEVERE POTENTIAL TODAY. SURFACE LOW CURRENTLY
OVER NORTHERN ILLINOIS WITH COLD FRONT DRAPED INTO WEST TEXAS
WILL PROGRESS EASTWARD TODAY. AHEAD OF THE FRONT SOUTH TO
SOUTHEAST SURFACE WINDS AND SOUTH TO SOUTHWEST WINDS AT H850 WILL
ALLOW FOR GOOD HEATING TODAY. H850 WINDS WILL ALSO KEEP A PRETTY
STRONG CAP IN PLACE FOR MUCH OF THE DAY...HAMPERING PRECIPITATION.
ANYTHING THAT WOULD DEVELOP THIS MORNING AND EARLY AFTERNOON
SHOULD JUST REMAIN SHOWER ACTIVITY. THE FRONT MOVES IN BY MID
AFTERNOON WIPING OUT THE CAP AND BRINGING A BRIEF WINDOW FOR
SEVERE WEATHER POTENTIAL. MOST MODELS ARE PEAKING CAPE ACROSS THE
AREA AROUND 1500-2000 J/KG THIS AFTERNOON...ALTHOUGH THE RUC AND
SOME MESO MODELS ARE A BIT HIGHER THAN THIS...ESPECIALLY EAST.
CONSENSUS FOR CONVECTIVE INITIATION SEEMS TO BE IN THE 20-21Z TIME
FRAME ALONG THE COLD FRONT WHERE CIN RAPIDLY DECREASES. LAPSE
700-500 LAPSE RATES LOOK FAVORABLE AND LI VALUES DECREASE TO AS
MUCH AS -8 DEPENDING ON THE MODEL. THE BIGGEST DETERRENT THOUGH MAY
BE THE SOUTHWESTERLY 850 MB WINDS. THIS COULD POTENTIALLY MAKE THE
CAP STRONG ENOUGH TO NOT ERODE BEFORE THE UPPER TROUGH MOVES
THROUGH...AND IT COULD ALSO BRING TOO MUCH DRY AIR IN...DEPENDING
ON THE DEPTH OF THESE SOUTHWEST WINDS. ADDITIONALLY...PWAT VALUES
ARE LESS THAN IMPRESSIVE FOR THE ENTIRE AREA...WITH MAINLY 1 TO
1.5 INCH VALUES EXPECTED.
WHILE THE ENTIRE FORECAST AREA HAS THE CHANCE TO SEE SEVERE
WEATHER...MAINLY A WIND AND HAIL THREAT...THE BEST CHANCE WILL BE
IN THE NORTHEAST PORTION OF THE FORECAST AREA...AND BETWEEN 21 AND
00Z.
THE UPPER TROUGH HANGS BACK A BIT, BUT SHOULD STILL MOVE
THROUGH BETWEEN 00 AND 06Z QUICKLY ENDING PRECIP CHANCES ACROSS
THE AREA. ONCE THE UPPER TROUGH GETS OUT OF HERE PLEASANT...BUT
BREEZY CONDITIONS WILL FILTER IN. TEMPERATURES SHOULD COOL NICELY
OVERNIGHT FRIDAY NIGHT INTO SATURDAY MORNING WITH TEMPS DECREASING
INTO THE 50S FOR MUCH OF THE AREA. SATURDAY LOOKS TO WARM BACK
INTO THE UPPER 70S AND 80S...BUT WITH MUCH LOWER DEWPOINTS.
MARINE...BEHIND THE COLD FRONT FRIDAY NIGHT STRONG OFFSHORE FLOW
WILL DEVELOP. WITH WARM SURFACE WATER TEMPERATURES GUSTS SHOULD
MIX DOWN PRETTY EASILY. THIS WILL LIKELY BRING NEAR GALE FORCE
GUSTS TO THE AREA BETWEEN 06Z AND 18Z SATURDAY. WILL HOLD OFF ON
ISSUING A GALE WATCH AT THIS TIME...BUT ONE MAY BE NEEDED LATER
TODAY. AT LEAST A SMALL CRAFT ADVISORY IS LIKELY.
LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)...UPPER LEVEL TROUGH WILL
BE EAST OF THE AREA TO START THE EXTENDED PART OF THE FORECAST.
DRIER AIR WILL BE ENTRENCHED OVER SOUTH TEXAS AS PRECIPITABLE WATER
VALUES FALL BELOW 0.75 INCHES. WITH WINDS BECOMING LIGHTER INLAND
AND THE DRY AIR...ANTICIPATE DECENT RADIATIONAL COOLING SATURDAY
NIGHT WITH TEMPS FALLING INTO THE LOWER/MID 50S ACROSS MUCH OF THE
REGION. A DRY NORTHWEST FLOW ALOFT WILL PREVAIL INTO EARLY NEXT WEEK
AS UPPER LEVEL RIDGE BECOMES ESTABLISHED ACROSS THE ROCKIES. SURFACE
HIGH WILL SHIFT TO THE EAST ON TUESDAY WITH ONSHORE FLOW RETURNING.
TEMPS WILL MODERATE THROUGH THE WEEK...WITH LOWER 90S ACROSS THE
WEST TO LOWER/MID 80S NEAR THE COAST WEDNESDAY THROUGH FRIDAY.
LATEST RUN OF THE GFS BREAKS THE UPPER RIDGE DOWN ON THURSDAY BUT
THE EURO KEEPS UPPER TROUGH OUT WEST THROUGH THE PERIOD. FORECAST
WILL CONTINUE TO FAVOR AMPLIFIED UPPER RIDGE SOLUTION FOR THE TIME
BEING. NO SIGNIFICANT CHANGES MADE TO THE EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 58 78 53 82 61 / 30 0 0 0 0
VICTORIA 54 76 50 79 57 / 30 0 0 0 0
LAREDO 63 85 58 89 61 / 10 0 0 0 0
ALICE 55 81 52 83 57 / 20 0 0 0 0
ROCKPORT 60 79 57 78 62 / 40 0 0 0 0
COTULLA 55 82 50 85 57 / 10 0 0 0 0
KINGSVILLE 58 79 52 83 59 / 30 0 0 0 0
NAVY CORPUS 62 78 61 78 65 / 40 0 0 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
WC/87...SHORT TERM
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
104 PM CDT FRI APR 20 2012
.UPDATE...
FOR SEVERE THUNDERSTORM WATCH 184.
&&
.DISCUSSION...
ISOLATED ELEVATED CONVECTION HAS BEGUN TO DEVELOP ACROSS EASTERN
PORTIONS OF THE CWA. ADDITIONAL DESTABILIZATION IS EXPECTED
THROUGH THE AFTERNOON HOURS ACROSS AREAS GENERALLY SOUTHEAST OF
THE I-35 CORRIDOR...WHERE ISOLATED SEVERE THUNDERSTORMS WITH LARGE
HAIL AND DAMAGING WINDS ARE POSSIBLE. SEVERE THUNDERSTORM WATCH
NUMBER 184 IS IN EFFECT FOR ERN/SERN PORTIONS OF THE CWA UNTIL 8
PM.
&&
.PREV DISCUSSION... /ISSUED 1210 PM CDT FRI APR 20 2012/
AVIATION...
COLD FRONT APPROACHING THE I-35 CORRIDOR LATE THIS MORNING WITH
DEVELOPING LINE OF SHRA/TSRA JUST BEHIND THE FRONT MOVING EASTWARD
AT 30 KNOTS. LINE OF CONVECTION WILL INCREASE IN INTENSITY AS IT
MOVES OVER I-35 OVER NEXT COUPLE HOURS AND THEN ON EAST OF I-35
DURING THE AFTERNOON AND EARLY EVENING/01Z. THERE REMAINS A SLIGHT
RISK OF SEVERE STORMS GENERALLY EAST OF I35/I37 THIS AFTERNOON
WITH LARGE HAIL/DAMAGING WINDS(1+ INCH/50+ KNOTS). BRIEF IFR
CONDITIONS MAINLY ASSOCIATED WITH THE SHRA/TSRA ALONG...OTHERWISE
BECOMING VFR CONDITIONS BEHIND THE FRONT AS DRY NLY WINDS OF 10-20
KNOTS DEVELOP. CLEARING-PREVAILING VFR CONDITIONS TONIGHT AND SATURDAY
BEHIND THE COLD FRONT AS IT CONTINUES SEWD TO JUST OFF THE MIDDLE
TX COAST BY 00Z. NLY WINDS OF 10-20 KNOTS PREVAILING TONIGHT AND
SATURDAY.
PREV DISCUSSION... /ISSUED 1055 AM CDT FRI APR 20 2012/
DISCUSSION...
SURFACE WINDS HAVE ALREADY BEGUN TO SHIFT TO THE NORTH ACROSS THE
CWA...BUT THE TRUE COLD FRONT IS STRETCHED ACROSS CENTRAL TEXAS/HILL
COUNTRY. THE FRONT IS STILL EXPECTED TO REACH THE I-35 CORRIDOR
AT AROUND NOON. AS THE FRONTAL BOUNDARY APPROACHES...SFC PRESSURE
GRADIENTS WILL TIGHTEN LEADING TO WINDS INCREASING TO 15 TO 20 MPH
WITH GUSTS OF 25 TO 30 MPH. SCATTERED SHOWERS WILL CONTINUE THROUGH
THIS MORNING AHEAD OF THE FRONT...WITH A BROKEN LINE OF SHOWERS
AND THUNDERSTORMS ALONG THE FRONTAL BOUNDARY. HAVE EXTENDED POPS A
LITTLE FURTHER WEST AND SOUTHWEST GIVEN THE CURRENT DEVELOPMENT
ALONG THE TAIL-END OF THE FRONT. WINDS AND WIND GUSTS WERE ALSO
INCREASED THROUGH THIS EVENING PER 12Z NAM/15Z RUC SUGGESTIONS AND
16Z SFC OBS. OTHERWISE HAVE ONLY MADE MINOR ADJUSTMENTS TO ACCOUNT
FOR HOURLY TRENDS.
PREV DISCUSSION... /ISSUED 713 AM CDT FRI APR 20 2012/
AVIATION...
AT 12Z COLD FRONT EXTENDED FROM COMANCHE TO BROWNWOOD TO SONORA
MOVING SOUTHEAST. THE COLD FRONT WILL PUSH INTO THE HILL COUNTRY
BY LATE MORNING AND PUSH RAPIDLY SOUTH ALONG THE I-35 CORRIDOR BY
EARLY AFTERNOON. AN UPPER DISTURBANCE INTERACTING WITH THE FRONT
WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
A FEW STORMS MAY BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS
THIS AFTERNOON ALONG AND EAST OF THE I-35 CORRIDOR...INCLUDING THE
KSAT...KSSF AND KAUS TERMINALS. I-35 CORRIDOR TERMINALS MVFR AND
BRIEF IFR CIGS EARLY THIS MORNING BECOMING MVFR CIGS BY LATE
MORNING WITH SCTD SHOWERS LOCALLY LOWERING VSBYS. LOW VFR CIGS
BY LATE MORNING WITH SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING LATE MORNING THROUGH MID AFTERNOON LOCALLY LOWERING
CIGS AND VSBYS. DECREASING CLOUDS LATE AFTERNOON BECOMING MOSTLY
CLEAR BY EVENING. I-35 CORRIDOR WINDS LIGHT AND VARIABLE TO LIGHT
SOUTHEAST TO EAST BECOMING NORTH 15 TO 20 KTS BY LATE MORNING.
NORTH WINDS LOWERING TO AROUND 10 KTS BY MIDNIGHT. KDRT TERMINAL
VARIABLE VFR CLOUDS BECOMING CLEAR THIS EVENING. EAST WIND 5 TO 10
KTS BECOMING NORTHWEST NEAR 15 KTS BY LATE MORNING. KDRT WINDS
BECOMING LIGHT NORTHEAST BY DARK.
PREV DISCUSSION... /ISSUED 347 AM CDT FRI APR 20 2012/
DISCUSSION...
AT 08Z THE COLD FRONT EXTENDED FROM PECOS TO SAN ANGELO TO SHERMAN
MOVING SOUTHEASTWARD. THE FRONT WILL ENTER THE HILL COUNTRY AROUND
9 AM AND WILL BE LOCATED ALONG THE I-35 CORRIDOR AROUND NOONTIME.
ISOLATED WARM SECTOR SHOWERS WILL OCCUR THIS MORNING UNDER THE CAP
IN ADVANCE OF THE FROPA AND LAGGING UPPER LEVEL TROF. THE SPC DAY
ONE CONVECTIVE OUTLOOK HAS OUR CWFA IN THE SLIGHT RISK AREA ALONG
AND EAST OF A LINE FROM LEXINGTON TO SAN MARCOS TO SAN ANTONIO TO
DILLEY AND WE AGREE WITH THIS DELINEATION. CONVECTION ALONG AND
BEHIND THE SHALLOW FRONTAL BOUNDARY WILL INCREASE AS THE SFC
FRONT NEARS THE I-35 CORRIDOR. THE PRIMARY SEVERE WEATHER THREATS
WILL BE LARGE HAIL AND DAMAGING WINDS ASSOCIATED WITH ACCELERATING
BOW SEGMENTS. THE SAN ANTONIO AND AUSTIN METRO AREAS ARE ON THE
WESTERN EDGE OF THE SLIGHT RISK AREA WHERE THE SEVERE STORMS MAY
FIRST INITIATE. THE CONVECTIVE COMPLEX WILL EXIT OUR SOUTHEAST
COUNTIES AROUND MIDNIGHT. HIGHS THIS AFTERNOON WILL RANGE FROM THE
MID 70S ACROSS OUR NORTHEAST COUNTIES TO UPPER 80S SOUTHWEST.
A DRY AIRMASS WILL OVERSPREAD SOUTH CENTRAL TEXAS IN THE WAKE OF
TODAYS FROPA. THIS WILL RESULT IN COOL NIGHTS FOLLOWED BY MILD
AFTERNOONS OVER THE WEEKEND. OVERNIGHT LOWS WILL FALL INTO THE
MID TO UPPER 40S ACROSS THE HILL COUNTRY. AFTERNOON HIGHS WILL BE
AROUND SEASONAL NORMALS.
A DRY NORTHWEST FLOW ALOFT WILL PREVAIL THRU THE MIDDLE OF NEXT
WEEK KEEPING SOUTH CENTRAL TEXAS RAIN FREE. THE UPPER LEVEL RIDGE
AXIS OVER NORTHERN MEXICO/SOUTHWESTERN U.S. WILL SHIFT EASTWARD
INTO TEXAS BY THE END OF NEXT WEEK. LOW LEVEL MOISTURE WILL BEGIN
TO RETURN TO SOUTH CENTRAL TEXAS TUESDAY NIGHT INTO WEDNESDAY
MORNING AS THE SFC HIGH MOVES OVER THE NORTHERN GULF OF MEXICO.
PATCHY MORNING FOG WILL BE POSSIBLE SOUTH AND EAST OF THE I-35
CORRIDOR WEDNESDAY MORNING AS THE AIRMASS BEGINS ITS TRANSITION
FROM CONTINENTAL TO GULF/MARITIME.
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS ARE POSSIBLE SATURDAY AFTERNOON
ACROSS THE EDWARDS PLATEAU AND RIO GRANDE PLAINS DUE TO LOW
RELATIVE HUMIDITIES. MINIMUM AFTERNOON RELATIVE HUMIDITIES WILL
FALL BELOW 25 PERCENT WEST OF A LINE FROM MOUNTAIN HOME TO HONDO
TO COTULLA WITH AROUND 20 PERCENT EXPECTED ALONG THE RIO GRANDE.
20-FOOT WINDS WILL BE NORTHERLY AT 5 TO 10 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 53 76 53 83 / 50 10 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 75 50 76 48 82 / 50 10 0 0 0
NEW BRAUNFELS MUNI AIRPORT 78 53 78 49 82 / 40 10 0 0 0
BURNET MUNI AIRPORT 74 49 75 48 81 / 40 - 0 0 0
DEL RIO INTL AIRPORT 86 55 83 54 87 / 10 - 0 0 0
GEORGETOWN MUNI AIRPORT 75 47 75 47 81 / 50 10 0 0 0
HONDO MUNI AIRPORT 82 50 80 48 84 / 30 - 0 0 0
SAN MARCOS MUNI AIRPORT 76 52 77 49 82 / 40 10 0 0 0
LA GRANGE - FAYETTE REGIONAL 76 54 75 53 80 / 60 10 0 0 0
SAN ANTONIO INTL AIRPORT 79 53 78 52 82 / 30 10 0 0 0
STINSON MUNI AIRPORT 80 55 79 53 83 / 30 10 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...01
SYNOPTIC/GRIDS...25
PUBLIC SERVICE/DATA COLLECTION...32
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1210 PM CDT FRI APR 20 2012
.AVIATION...
COLD FRONT APPROACHING THE I-35 CORRIDOR LATE THIS MORNING WITH
DEVELOPING LINE OF SHRA/TSRA JUST BEHIND THE FRONT MOVING EASTWARD
AT 30 KNOTS. LINE OF CONVECTION WILL INCREASE IN INTENSITY AS IT
MOVES OVER I-35 OVER NEXT COUPLE HOURS AND THEN ON EAST OF I-35
DURING THE AFTERNOON AND EARLY EVENING/01Z. THERE REMAINS A SLIGHT
RISK OF SEVERE STORMS GENERALLY EAST OF I35/I37 THIS AFTERNOON
WITH LARGE HAIL/DAMAGING WINDS(1+ INCH/50+ KNOTS). BRIEF IFR
CONDITIONS MAINLY ASSOCIATED WITH THE SHRA/TSRA ALONG...OTHERWISE
BECOMING VFR CONDITIONS BEHIND THE FRONT AS DRY NLY WINDS OF 10-20
KNOTS DEVELOP. CLEARING-PREVAILING VFR CONDITIONS TONIGHT AND SATURDAY
BEHIND THE COLD FRONT AS IT CONTINUES SEWD TO JUST OFF THE MIDDLE
TX COAST BY 00Z. NLY WINDS OF 10-20 KNOTS PREVAILING TONIGHT AND
SATURDAY.
&&
.PREV DISCUSSION... /ISSUED 1055 AM CDT FRI APR 20 2012/
DISCUSSION...
SURFACE WINDS HAVE ALREADY BEGUN TO SHIFT TO THE NORTH ACROSS THE
CWA...BUT THE TRUE COLD FRONT IS STRETCHED ACROSS CENTRAL TEXAS/HILL
COUNTRY. THE FRONT IS STILL EXPECTED TO REACH THE I-35 CORRIDOR
AT AROUND NOON. AS THE FRONTAL BOUNDARY APPROACHES...SFC PRESSURE
GRADIENTS WILL TIGHTEN LEADING TO WINDS INCREASING TO 15 TO 20 MPH
WITH GUSTS OF 25 TO 30 MPH. SCATTERED SHOWERS WILL CONTINUE THROUGH
THIS MORNING AHEAD OF THE FRONT...WITH A BROKEN LINE OF SHOWERS
AND THUNDERSTORMS ALONG THE FRONTAL BOUNDARY. HAVE EXTENDED POPS A
LITTLE FURTHER WEST AND SOUTHWEST GIVEN THE CURRENT DEVELOPMENT
ALONG THE TAIL-END OF THE FRONT. WINDS AND WIND GUSTS WERE ALSO
INCREASED THROUGH THIS EVENING PER 12Z NAM/15Z RUC SUGGESTIONS AND
16Z SFC OBS. OTHERWISE HAVE ONLY MADE MINOR ADJUSTMENTS TO ACCOUNT
FOR HOURLY TRENDS.
PREV DISCUSSION... /ISSUED 713 AM CDT FRI APR 20 2012/
AVIATION...
AT 12Z COLD FRONT EXTENDED FROM COMANCHE TO BROWNWOOD TO SONORA
MOVING SOUTHEAST. THE COLD FRONT WILL PUSH INTO THE HILL COUNTRY
BY LATE MORNING AND PUSH RAPIDLY SOUTH ALONG THE I-35 CORRIDOR BY
EARLY AFTERNOON. AN UPPER DISTURBANCE INTERACTING WITH THE FRONT
WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
A FEW STORMS MAY BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS
THIS AFTERNOON ALONG AND EAST OF THE I-35 CORRIDOR...INCLUDING THE
KSAT...KSSF AND KAUS TERMINALS. I-35 CORRIDOR TERMINALS MVFR AND
BRIEF IFR CIGS EARLY THIS MORNING BECOMING MVFR CIGS BY LATE
MORNING WITH SCTD SHOWERS LOCALLY LOWERING VSBYS. LOW VFR CIGS
BY LATE MORNING WITH SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING LATE MORNING THROUGH MID AFTERNOON LOCALLY LOWERING
CIGS AND VSBYS. DECREASING CLOUDS LATE AFTERNOON BECOMING MOSTLY
CLEAR BY EVENING. I-35 CORRIDOR WINDS LIGHT AND VARIABLE TO LIGHT
SOUTHEAST TO EAST BECOMING NORTH 15 TO 20 KTS BY LATE MORNING.
NORTH WINDS LOWERING TO AROUND 10 KTS BY MIDNIGHT. KDRT TERMINAL
VARIABLE VFR CLOUDS BECOMING CLEAR THIS EVENING. EAST WIND 5 TO 10
KTS BECOMING NORTHWEST NEAR 15 KTS BY LATE MORNING. KDRT WINDS
BECOMING LIGHT NORTHEAST BY DARK.
PREV DISCUSSION... /ISSUED 347 AM CDT FRI APR 20 2012/
DISCUSSION...
AT 08Z THE COLD FRONT EXTENDED FROM PECOS TO SAN ANGELO TO SHERMAN
MOVING SOUTHEASTWARD. THE FRONT WILL ENTER THE HILL COUNTRY AROUND
9 AM AND WILL BE LOCATED ALONG THE I-35 CORRIDOR AROUND NOONTIME.
ISOLATED WARM SECTOR SHOWERS WILL OCCUR THIS MORNING UNDER THE CAP
IN ADVANCE OF THE FROPA AND LAGGING UPPER LEVEL TROF. THE SPC DAY
ONE CONVECTIVE OUTLOOK HAS OUR CWFA IN THE SLIGHT RISK AREA ALONG
AND EAST OF A LINE FROM LEXINGTON TO SAN MARCOS TO SAN ANTONIO TO
DILLEY AND WE AGREE WITH THIS DELINEATION. CONVECTION ALONG AND
BEHIND THE SHALLOW FRONTAL BOUNDARY WILL INCREASE AS THE SFC
FRONT NEARS THE I-35 CORRIDOR. THE PRIMARY SEVERE WEATHER THREATS
WILL BE LARGE HAIL AND DAMAGING WINDS ASSOCIATED WITH ACCELERATING
BOW SEGMENTS. THE SAN ANTONIO AND AUSTIN METRO AREAS ARE ON THE
WESTERN EDGE OF THE SLIGHT RISK AREA WHERE THE SEVERE STORMS MAY
FIRST INITIATE. THE CONVECTIVE COMPLEX WILL EXIT OUR SOUTHEAST
COUNTIES AROUND MIDNIGHT. HIGHS THIS AFTERNOON WILL RANGE FROM THE
MID 70S ACROSS OUR NORTHEAST COUNTIES TO UPPER 80S SOUTHWEST.
A DRY AIRMASS WILL OVERSPREAD SOUTH CENTRAL TEXAS IN THE WAKE OF
TODAYS FROPA. THIS WILL RESULT IN COOL NIGHTS FOLLOWED BY MILD
AFTERNOONS OVER THE WEEKEND. OVERNIGHT LOWS WILL FALL INTO THE
MID TO UPPER 40S ACROSS THE HILL COUNTRY. AFTERNOON HIGHS WILL BE
AROUND SEASONAL NORMALS.
A DRY NORTHWEST FLOW ALOFT WILL PREVAIL THRU THE MIDDLE OF NEXT
WEEK KEEPING SOUTH CENTRAL TEXAS RAIN FREE. THE UPPER LEVEL RIDGE
AXIS OVER NORTHERN MEXICO/SOUTHWESTERN U.S. WILL SHIFT EASTWARD
INTO TEXAS BY THE END OF NEXT WEEK. LOW LEVEL MOISTURE WILL BEGIN
TO RETURN TO SOUTH CENTRAL TEXAS TUESDAY NIGHT INTO WEDNESDAY
MORNING AS THE SFC HIGH MOVES OVER THE NORTHERN GULF OF MEXICO.
PATCHY MORNING FOG WILL BE POSSIBLE SOUTH AND EAST OF THE I-35
CORRIDOR WEDNESDAY MORNING AS THE AIRMASS BEGINS ITS TRANSITION
FROM CONTINENTAL TO GULF/MARITIME.
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS ARE POSSIBLE SATURDAY AFTERNOON
ACROSS THE EDWARDS PLATEAU AND RIO GRANDE PLAINS DUE TO LOW
RELATIVE HUMIDITIES. MINIMUM AFTERNOON RELATIVE HUMIDITIES WILL
FALL BELOW 25 PERCENT WEST OF A LINE FROM MOUNTAIN HOME TO HONDO
TO COTULLA WITH AROUND 20 PERCENT EXPECTED ALONG THE RIO GRANDE.
20-FOOT WINDS WILL BE NORTHERLY AT 5 TO 10 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 53 76 53 83 / 50 10 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 75 50 76 48 82 / 50 10 0 0 0
NEW BRAUNFELS MUNI AIRPORT 78 53 78 49 82 / 40 10 0 0 0
BURNET MUNI AIRPORT 74 49 75 48 81 / 40 - 0 0 0
DEL RIO INTL AIRPORT 86 55 83 54 87 / 10 - 0 0 0
GEORGETOWN MUNI AIRPORT 75 47 75 47 81 / 50 10 0 0 0
HONDO MUNI AIRPORT 82 50 80 48 84 / 30 - 0 0 0
SAN MARCOS MUNI AIRPORT 76 52 77 49 82 / 40 10 0 0 0
LA GRANGE - FAYETTE REGIONAL 76 54 75 53 80 / 60 10 0 0 0
SAN ANTONIO INTL AIRPORT 79 53 78 52 82 / 30 10 0 0 0
STINSON MUNI AIRPORT 80 55 79 53 83 / 30 10 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...01
SYNOPTIC/GRIDS...25
PUBLIC SERVICE/DATA COLLECTION...32
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1055 AM CDT FRI APR 20 2012
.DISCUSSION...
SURFACE WINDS HAVE ALREADY BEGUN TO SHIFT TO THE NORTH ACROSS THE
CWA...BUT THE TRUE COLD FRONT IS STRETCHED ACROSS CENTRAL TEXAS/HILL
COUNTRY. THE FRONT IS STILL EXPECTED TO REACH THE I-35 CORRIDOR
AT AROUND NOON. AS THE FRONTAL BOUNDARY APPROACHES...SFC PRESSURE
GRADIENTS WILL TIGHTEN LEADING TO WINDS INCREASING TO 15 TO 20 MPH
WITH GUSTS OF 25 TO 30 MPH. SCATTERED SHOWERS WILL CONTINUE THROUGH
THIS MORNING AHEAD OF THE FRONT...WITH A BROKEN LINE OF SHOWERS
AND THUNDERSTORMS ALONG THE FRONTAL BOUNDARY. HAVE EXTENDED POPS A
LITTLE FURTHER WEST AND SOUTHWEST GIVEN THE CURRENT DEVELOPMENT
ALONG THE TAIL-END OF THE FRONT. WINDS AND WIND GUSTS WERE ALSO
INCREASED THROUGH THIS EVENING PER 12Z NAM/15Z RUC SUGGESTIONS AND
16Z SFC OBS. OTHERWISE HAVE ONLY MADE MINOR ADJUSTMENTS TO ACCOUNT
FOR HOURLY TRENDS.
&&
.PREV DISCUSSION... /ISSUED 713 AM CDT FRI APR 20 2012/
AVIATION...
AT 12Z COLD FRONT EXTENDED FROM COMANCHE TO BROWNWOOD TO SONORA
MOVING SOUTHEAST. THE COLD FRONT WILL PUSH INTO THE HILL COUNTRY
BY LATE MORNING AND PUSH RAPIDLY SOUTH ALONG THE I-35 CORRIDOR BY
EARLY AFTERNOON. AN UPPER DISTURBANCE INTERACTING WITH THE FRONT
WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
A FEW STORMS MAY BECOME SEVERE WITH LARGE HAIL AND DAMAGING WINDS
THIS AFTERNOON ALONG AND EAST OF THE I-35 CORRIDOR...INCLUDING THE
KSAT...KSSF AND KAUS TERMINALS. I-35 CORRIDOR TERMINALS MVFR AND
BRIEF IFR CIGS EARLY THIS MORNING BECOMING MVFR CIGS BY LATE
MORNING WITH SCTD SHOWERS LOCALLY LOWERING VSBYS. LOW VFR CIGS
BY LATE MORNING WITH SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING LATE MORNING THROUGH MID AFTERNOON LOCALLY LOWERING
CIGS AND VSBYS. DECREASING CLOUDS LATE AFTERNOON BECOMING MOSTLY
CLEAR BY EVENING. I-35 CORRIDOR WINDS LIGHT AND VARIABLE TO LIGHT
SOUTHEAST TO EAST BECOMING NORTH 15 TO 20 KTS BY LATE MORNING.
NORTH WINDS LOWERING TO AROUND 10 KTS BY MIDNIGHT. KDRT TERMINAL
VARIABLE VFR CLOUDS BECOMING CLEAR THIS EVENING. EAST WIND 5 TO 10
KTS BECOMING NORTHWEST NEAR 15 KTS BY LATE MORNING. KDRT WINDS
BECOMING LIGHT NORTHEAST BY DARK.
PREV DISCUSSION... /ISSUED 347 AM CDT FRI APR 20 2012/
DISCUSSION...
AT 08Z THE COLD FRONT EXTENDED FROM PECOS TO SAN ANGELO TO SHERMAN
MOVING SOUTHEASTWARD. THE FRONT WILL ENTER THE HILL COUNTRY AROUND
9 AM AND WILL BE LOCATED ALONG THE I-35 CORRIDOR AROUND NOONTIME.
ISOLATED WARM SECTOR SHOWERS WILL OCCUR THIS MORNING UNDER THE CAP
IN ADVANCE OF THE FROPA AND LAGGING UPPER LEVEL TROF. THE SPC DAY
ONE CONVECTIVE OUTLOOK HAS OUR CWFA IN THE SLIGHT RISK AREA ALONG
AND EAST OF A LINE FROM LEXINGTON TO SAN MARCOS TO SAN ANTONIO TO
DILLEY AND WE AGREE WITH THIS DELINEATION. CONVECTION ALONG AND
BEHIND THE SHALLOW FRONTAL BOUNDARY WILL INCREASE AS THE SFC
FRONT NEARS THE I-35 CORRIDOR. THE PRIMARY SEVERE WEATHER THREATS
WILL BE LARGE HAIL AND DAMAGING WINDS ASSOCIATED WITH ACCELERATING
BOW SEGMENTS. THE SAN ANTONIO AND AUSTIN METRO AREAS ARE ON THE
WESTERN EDGE OF THE SLIGHT RISK AREA WHERE THE SEVERE STORMS MAY
FIRST INITIATE. THE CONVECTIVE COMPLEX WILL EXIT OUR SOUTHEAST
COUNTIES AROUND MIDNIGHT. HIGHS THIS AFTERNOON WILL RANGE FROM THE
MID 70S ACROSS OUR NORTHEAST COUNTIES TO UPPER 80S SOUTHWEST.
A DRY AIRMASS WILL OVERSPREAD SOUTH CENTRAL TEXAS IN THE WAKE OF
TODAYS FROPA. THIS WILL RESULT IN COOL NIGHTS FOLLOWED BY MILD
AFTERNOONS OVER THE WEEKEND. OVERNIGHT LOWS WILL FALL INTO THE
MID TO UPPER 40S ACROSS THE HILL COUNTRY. AFTERNOON HIGHS WILL BE
AROUND SEASONAL NORMALS.
A DRY NORTHWEST FLOW ALOFT WILL PREVAIL THRU THE MIDDLE OF NEXT
WEEK KEEPING SOUTH CENTRAL TEXAS RAIN FREE. THE UPPER LEVEL RIDGE
AXIS OVER NORTHERN MEXICO/SOUTHWESTERN U.S. WILL SHIFT EASTWARD
INTO TEXAS BY THE END OF NEXT WEEK. LOW LEVEL MOISTURE WILL BEGIN
TO RETURN TO SOUTH CENTRAL TEXAS TUESDAY NIGHT INTO WEDNESDAY
MORNING AS THE SFC HIGH MOVES OVER THE NORTHERN GULF OF MEXICO.
PATCHY MORNING FOG WILL BE POSSIBLE SOUTH AND EAST OF THE I-35
CORRIDOR WEDNESDAY MORNING AS THE AIRMASS BEGINS ITS TRANSITION
FROM CONTINENTAL TO GULF/MARITIME.
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS ARE POSSIBLE SATURDAY AFTERNOON
ACROSS THE EDWARDS PLATEAU AND RIO GRANDE PLAINS DUE TO LOW
RELATIVE HUMIDITIES. MINIMUM AFTERNOON RELATIVE HUMIDITIES WILL
FALL BELOW 25 PERCENT WEST OF A LINE FROM MOUNTAIN HOME TO HONDO
TO COTULLA WITH AROUND 20 PERCENT EXPECTED ALONG THE RIO GRANDE.
20-FOOT WINDS WILL BE NORTHERLY AT 5 TO 10 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 53 76 53 83 / 50 10 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 75 50 76 48 82 / 50 10 0 0 0
NEW BRAUNFELS MUNI AIRPORT 78 53 78 49 82 / 40 10 0 0 0
BURNET MUNI AIRPORT 74 49 75 48 81 / 40 - 0 0 0
DEL RIO INTL AIRPORT 86 55 83 54 87 / 10 - 0 0 0
GEORGETOWN MUNI AIRPORT 75 47 75 47 81 / 50 10 0 0 0
HONDO MUNI AIRPORT 82 50 80 48 84 / 30 - 0 0 0
SAN MARCOS MUNI AIRPORT 76 52 77 49 82 / 40 10 0 0 0
LA GRANGE - FAYETTE REGIONAL 76 54 75 53 80 / 60 10 0 0 0
SAN ANTONIO INTL AIRPORT 79 53 78 52 82 / 30 10 0 0 0
STINSON MUNI AIRPORT 80 55 79 53 83 / 30 10 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...01
SYNOPTIC/GRIDS...25
PUBLIC SERVICE/DATA COLLECTION...32
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
627 AM CDT FRI APR 20 2012
.DISCUSSION...UPDATED FOR 12Z AVIATION.
&&
.AVIATION...CLOUDS WILL BEGIN TO BUILD IN THIS MORNING AHEAD OF AN
APPROACHING COLD FRONT. THIS FRONT WILL PUSH THROUGH THE TAF SITES
THIS AFTERNOON WITH THUNDERSTORM CHANCES JUST AHEAD OF AND ALONG
THE FRONT. SOME STORMS...ESPECIALLY FOR EASTERN SITES MAY BE
SEVERE THIS EVENING. GUSTY NORTHERLY WINDS ARE EXPECTED TO DEVELOP
BEHIND THE FRONT AND LINGER OVERNIGHT. VFR CONDITIONS WILL RETURN
FOR SATURDAY.
&&
.PREV DISCUSSION... /ISSUED 416 AM CDT FRI APR 20 2012/
SHORT TERM (TODAY THROUGH SATURDAY)...MAIN FORECAST CONCERN IS
WITH THUNDER AND SEVERE POTENTIAL TODAY. SURFACE LOW CURRENTLY
OVER NORTHERN ILLINOIS WITH COLD FRONT DRAPED INTO WEST TEXAS
WILL PROGRESS EASTWARD TODAY. AHEAD OF THE FRONT SOUTH TO
SOUTHEAST SURFACE WINDS AND SOUTH TO SOUTHWEST WINDS AT H850 WILL
ALLOW FOR GOOD HEATING TODAY. H850 WINDS WILL ALSO KEEP A PRETTY
STRONG CAP IN PLACE FOR MUCH OF THE DAY...HAMPERING PRECIPITATION.
ANYTHING THAT WOULD DEVELOP THIS MORNING AND EARLY AFTERNOON
SHOULD JUST REMAIN SHOWER ACTIVITY. THE FRONT MOVES IN BY MID
AFTERNOON WIPING OUT THE CAP AND BRINGING A BRIEF WINDOW FOR
SEVERE WEATHER POTENTIAL. MOST MODELS ARE PEAKING CAPE ACROSS THE
AREA AROUND 1500-2000 J/KG THIS AFTERNOON...ALTHOUGH THE RUC AND
SOME MESO MODELS ARE A BIT HIGHER THAN THIS...ESPECIALLY EAST.
CONSENSUS FOR CONVECTIVE INITIATION SEEMS TO BE IN THE 20-21Z TIME
FRAME ALONG THE COLD FRONT WHERE CIN RAPIDLY DECREASES. LAPSE
700-500 LAPSE RATES LOOK FAVORABLE AND LI VALUES DECREASE TO AS
MUCH AS -8 DEPENDING ON THE MODEL. THE BIGGEST DETERRENT THOUGH MAY
BE THE SOUTHWESTERLY 850 MB WINDS. THIS COULD POTENTIALLY MAKE THE
CAP STRONG ENOUGH TO NOT ERODE BEFORE THE UPPER TROUGH MOVES
THROUGH...AND IT COULD ALSO BRING TOO MUCH DRY AIR IN...DEPENDING
ON THE DEPTH OF THESE SOUTHWEST WINDS. ADDITIONALLY...PWAT VALUES
ARE LESS THAN IMPRESSIVE FOR THE ENTIRE AREA...WITH MAINLY 1 TO
1.5 INCH VALUES EXPECTED.
WHILE THE ENTIRE FORECAST AREA HAS THE CHANCE TO SEE SEVERE
WEATHER...MAINLY A WIND AND HAIL THREAT...THE BEST CHANCE WILL BE
IN THE NORTHEAST PORTION OF THE FORECAST AREA...AND BETWEEN 21 AND
00Z.
THE UPPER TROUGH HANGS BACK A BIT, BUT SHOULD STILL MOVE
THROUGH BETWEEN 00 AND 06Z QUICKLY ENDING PRECIP CHANCES ACROSS
THE AREA. ONCE THE UPPER TROUGH GETS OUT OF HERE PLEASANT...BUT
BREEZY CONDITIONS WILL FILTER IN. TEMPERATURES SHOULD COOL NICELY
OVERNIGHT FRIDAY NIGHT INTO SATURDAY MORNING WITH TEMPS DECREASING
INTO THE 50S FOR MUCH OF THE AREA. SATURDAY LOOKS TO WARM BACK
INTO THE UPPER 70S AND 80S...BUT WITH MUCH LOWER DEWPOINTS.
MARINE...BEHIND THE COLD FRONT FRIDAY NIGHT STRONG OFFSHORE FLOW
WILL DEVELOP. WITH WARM SURFACE WATER TEMPERATURES GUSTS SHOULD
MIX DOWN PRETTY EASILY. THIS WILL LIKELY BRING NEAR GALE FORCE
GUSTS TO THE AREA BETWEEN 06Z AND 18Z SATURDAY. WILL HOLD OFF ON
ISSUING A GALE WATCH AT THIS TIME...BUT ONE MAY BE NEEDED LATER
TODAY. AT LEAST A SMALL CRAFT ADVISORY IS LIKELY.
LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)...UPPER LEVEL TROUGH WILL
BE EAST OF THE AREA TO START THE EXTENDED PART OF THE FORECAST.
DRIER AIR WILL BE ENTRENCHED OVER SOUTH TEXAS AS PRECIPITABLE WATER
VALUES FALL BELOW 0.75 INCHES. WITH WINDS BECOMING LIGHTER INLAND
AND THE DRY AIR...ANTICIPATE DECENT RADIATIONAL COOLING SATURDAY
NIGHT WITH TEMPS FALLING INTO THE LOWER/MID 50S ACROSS MUCH OF THE
REGION. A DRY NORTHWEST FLOW ALOFT WILL PREVAIL INTO EARLY NEXT WEEK
AS UPPER LEVEL RIDGE BECOMES ESTABLISHED ACROSS THE ROCKIES. SURFACE
HIGH WILL SHIFT TO THE EAST ON TUESDAY WITH ONSHORE FLOW RETURNING.
TEMPS WILL MODERATE THROUGH THE WEEK...WITH LOWER 90S ACROSS THE
WEST TO LOWER/MID 80S NEAR THE COAST WEDNESDAY THROUGH FRIDAY.
LATEST RUN OF THE GFS BREAKS THE UPPER RIDGE DOWN ON THURSDAY BUT
THE EURO KEEPS UPPER TROUGH OUT WEST THROUGH THE PERIOD. FORECAST
WILL CONTINUE TO FAVOR AMPLIFIED UPPER RIDGE SOLUTION FOR THE TIME
BEING. NO SIGNIFICANT CHANGES MADE TO THE EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 81 58 78 53 82 / 40 30 0 0 0
VICTORIA 80 54 76 50 79 / 50 30 0 0 0
LAREDO 90 63 85 58 89 / 20 10 0 0 0
ALICE 85 55 81 52 83 / 30 20 0 0 0
ROCKPORT 79 60 79 57 78 / 40 40 0 0 0
COTULLA 87 55 82 50 85 / 20 10 0 0 0
KINGSVILLE 83 58 79 52 83 / 40 30 0 0 0
NAVY CORPUS 79 62 78 61 78 / 40 40 0 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...SHORT TERM
TB/78...LONG TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
416 AM CDT FRI APR 20 2012
.SHORT TERM (TODAY THROUGH SATURDAY)...MAIN FORECAST CONCERN IS
WITH THUNDER AND SEVERE POTENTIAL TODAY. SURFACE LOW CURRENTLY
OVER NORTHERN ILLINOIS WITH COLD FRONT DRAPED INTO WEST TEXAS
WILL PROGRESS EASTWARD TODAY. AHEAD OF THE FRONT SOUTH TO
SOUTHEAST SURFACE WINDS AND SOUTH TO SOUTHWEST WINDS AT H850 WILL
ALLOW FOR GOOD HEATING TODAY. H850 WINDS WILL ALSO KEEP A PRETTY
STRONG CAP IN PLACE FOR MUCH OF THE DAY...HAMPERING PRECIPITATION.
ANYTHING THAT WOULD DEVELOP THIS MORNING AND EARLY AFTERNOON
SHOULD JUST REMAIN SHOWER ACTIVITY. THE FRONT MOVES IN BY MID
AFTERNOON WIPING OUT THE CAP AND BRINGING A BRIEF WINDOW FOR
SEVERE WEATHER POTENTIAL. MOST MODELS ARE PEAKING CAPE ACROSS THE
AREA AROUND 1500-2000 J/KG THIS AFTERNOON...ALTHOUGH THE RUC AND
SOME MESO MODELS ARE A BIT HIGHER THAN THIS...ESPECIALLY EAST.
CONSENSUS FOR CONVECTIVE INITIATION SEEMS TO BE IN THE 20-21Z TIME
FRAME ALONG THE COLD FRONT WHERE CIN RAPIDLY DECREASES. LAPSE
700-500 LAPSE RATES LOOK FAVORABLE AND LI VALUES DECREASE TO AS
MUCH AS -8 DEPENDING ON THE MODEL. THE BIGGEST DETERRENT THOUGH MAY
BE THE SOUTHWESTERLY 850 MB WINDS. THIS COULD POTENTIALLY MAKE THE
CAP STRONG ENOUGH TO NOT ERODE BEFORE THE UPPER TROUGH MOVES
THROUGH...AND IT COULD ALSO BRING TOO MUCH DRY AIR IN...DEPENDING
ON THE DEPTH OF THESE SOUTHWEST WINDS. ADDITIONALLY...PWAT VALUES
ARE LESS THAN IMPRESSIVE FOR THE ENTIRE AREA...WITH MAINLY 1 TO
1.5 INCH VALUES EXPECTED.
WHILE THE ENTIRE FORECAST AREA HAS THE CHANCE TO SEE SEVERE
WEATHER...MAINLY A WIND AND HAIL THREAT...THE BEST CHANCE WILL BE
IN THE NORTHEAST PORTION OF THE FORECAST AREA...AND BETWEEN 21 AND
00Z.
THE UPPER TROUGH HANGS BACK A BIT, BUT SHOULD STILL MOVE
THROUGH BETWEEN 00 AND 06Z QUICKLY ENDING PRECIP CHANCES ACROSS
THE AREA. ONCE THE UPPER TROUGH GETS OUT OF HERE PLEASANT...BUT
BREEZY CONDITIONS WILL FILTER IN. TEMPERATURES SHOULD COOL NICELY
OVERNIGHT FRIDAY NIGHT INTO SATURDAY MORNING WITH TEMPS DECREASING
INTO THE 50S FOR MUCH OF THE AREA. SATURDAY LOOKS TO WARM BACK
INTO THE UPPER 70S AND 80S...BUT WITH MUCH LOWER DEWPOINTS.
&&
.MARINE...BEHIND THE COLD FRONT FRIDAY NIGHT STRONG OFFSHORE FLOW
WILL DEVELOP. WITH WARM SURFACE WATER TEMPERATURES GUSTS SHOULD
MIX DOWN PRETTY EASILY. THIS WILL LIKELY BRING NEAR GALE FORCE
GUSTS TO THE AREA BETWEEN 06Z AND 18Z SATURDAY. WILL HOLD OFF ON
ISSUING A GALE WATCH AT THIS TIME...BUT ONE MAY BE NEEDED LATER
TODAY. AT LEAST A SMALL CRAFT ADVISORY IS LIKELY.
&&
.LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)...UPPER LEVEL TROUGH WILL
BE EAST OF THE AREA TO START THE EXTENDED PART OF THE FORECAST.
DRIER AIR WILL BE ENTRENCHED OVER SOUTH TEXAS AS PRECIPITABLE WATER
VALUES FALL BELOW 0.75 INCHES. WITH WINDS BECOMING LIGHTER INLAND
AND THE DRY AIR...ANTICIPATE DECENT RADIATIONAL COOLING SATURDAY
NIGHT WITH TEMPS FALLING INTO THE LOWER/MID 50S ACROSS MUCH OF THE
REGION. A DRY NORTHWEST FLOW ALOFT WILL PREVAIL INTO EARLY NEXT WEEK
AS UPPER LEVEL RIDGE BECOMES ESTABLISHED ACROSS THE ROCKIES. SURFACE
HIGH WILL SHIFT TO THE EAST ON TUESDAY WITH ONSHORE FLOW RETURNING.
TEMPS WILL MODERATE THROUGH THE WEEK...WITH LOWER 90S ACROSS THE
WEST TO LOWER/MID 80S NEAR THE COAST WEDNESDAY THROUGH FRIDAY.
LATEST RUN OF THE GFS BREAKS THE UPPER RIDGE DOWN ON THURSDAY BUT
THE EURO KEEPS UPPER TROUGH OUT WEST THROUGH THE PERIOD. FORECAST
WILL CONTINUE TO FAVOR AMPLIFIED UPPER RIDGE SOLUTION FOR THE TIME
BEING. NO SIGNIFICANT CHANGES MADE TO THE EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 81 58 78 53 82 / 40 30 0 0 0
VICTORIA 80 54 76 50 79 / 50 30 0 0 0
LAREDO 90 63 85 58 89 / 20 10 0 0 0
ALICE 85 55 81 52 83 / 30 20 0 0 0
ROCKPORT 79 60 79 57 78 / 40 40 0 0 0
COTULLA 87 55 82 50 85 / 20 10 0 0 0
KINGSVILLE 83 58 79 52 83 / 40 30 0 0 0
NAVY CORPUS 79 62 78 61 78 / 40 40 0 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...SHORT TERM
TB/78...LONG TERM
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1141 PM CDT THU APR 19 2012
.AVIATION...
OUTFLOW FROM STORMS OVER NORTHWEST COUNTIES PUSHED INTO THE METROPLEX
WHILE WEAKENING WITH TIME. AFTER A BRIEF SHIFT AROUND TO
THE NORTH...WINDS SHOULD PICK BACK UP OUT OF THE SOUTH TO
SOUTHEAST AHEAD OF A COLD FRONT. THE FRONT CONTINUES TO TRUDGE
SOUTHEAST THROUGH OKLAHOMA AND NORTHWEST TEXAS...AND IS EXPECTED
TO REACH THE DALLAS-FORT WORTH METROPLEX AROUND 8 AM....AND THE
WACO AREA A COUPLE OF HOURS LATER. STORMS REMAIN ACTIVE ALONG AND
IMMEDIATELY BEHIND THE FRONT...AIDED BY A SHARPENING TROUGH WHICH
CONTINUES TO DIVE SOUTHEAST THROUGH THE CENTRAL PLAINS.
ISOLATED SHOWERS AND STORMS ARE A SLIM POSSIBILITY OVERNIGHT ASSOCIATED
WITH MESOSCALE BOUNDARIES AHEAD OF THE MAIN FRONT. WILL NEED TO
KEEP AN EYE ON NEW ACTIVITY DEVELOPING OVER WESTERN COUNTIES AS IT
WOULD APPROACH THE FORT WORTH AREA FROM THE WEST IN A FEW HOURS IF
IT HOLDS TOGETHER. WILL KEEP AT LEAST A VCSH FOR MUCH OF THE
OVERNIGHT HOURS...WITH THE POSSIBILITY OF ADDING THUNDER IF NEW
CELLS TO THE WEST CONTINUE TO INTENSIFY. WILL ALSO MENTION THUNDER
AROUND THE TIME OF FROPA IN THE MORNING. WINDS WILL SHIFT TO THE
NORTH BEHIND THE FRONT AND BECOME A BIT GUSTY BY MIDDAY. VFR
CONDITIONS AND LIGHTER WINDS CAN THEN BE EXPECTED FRIDAY EVENING
AS HIGH PRESSURE SLIDES IN ACROSS THE REGION.
30
&&
.UPDATE...
DUE TO THE NEARLY DRY ADIABATIC LAPSE RATES AND THE STRONG FORCING
THAT WILL BE OVERSPREADING THE REGION FROM THE NORTHWEST
TONIGHT...THE CONVECTIVE FORECAST IS HIGHLY SENSITIVE TO THE
AMOUNT OF MOISTURE AVAILABLE IN THE MID LEVELS...SPECIFICALLY
MOISTURE NEAR 700 MB. THE 00Z SOUNDING DATA FROM AROUND THE REGION
SHOWED THE MID LEVELS TOO DRY FOR CONVECTION AT FWD/DRT/MAF...BUT
INDICATED AMPLE MOISTURE AT AMA. TONIGHT/S FORECAST WOULD BE EASIER
IF WE HAD ANOTHER SOUNDING NEAR ABILENE...BUT WE DO NOT...SO WE
WILL HAVE TO INFER THAT GIVEN THE EXTENSIVE ACCUS FIELD THAT
DEVELOPED EARLIER...THAT THE MOISTURE IS AVAILABLE. THE RUC IS
PARTICULARLY AGGRESSIVE WITH INDICATING A POCKET OF MOISTURE FROM
SJT-ABI-SPS THAT WILL MOVE EASTWARD INTO THE WESTERN AND CENTRAL
ZONES LATER TONIGHT. THIS SOLUTION IS ALSO SUPPORTED BY THE HRRR.
THUS I THINK THERE ARE ENOUGH INDICATIONS THAT THIS POCKET OF
700MB MOISTURE DOES EXIST...AND AS IT ARRIVES INTO THE AREA LATER
TONIGHT...SHOULD RESULT IN AN INCREASE IN ELEVATED SHOWERS AND
STORMS ACROSS THE WESTERN ZONES. ACTIVITY SHOULD SPREAD EAST INTO
THE CENTRAL ZONES EARLY FRIDAY MORNING. HAVE INCREASED POPS TO
30-40 PERCENT ACROSS THE WESTERN AND CENTRAL ZONES. MARGINALLY
SEVERE HAIL WILL BE POSSIBLE WITH THE STRONGEST CELLS.
OTHERWISE...SMALL LINE SEGMENT OF STRONG/SEVERE CONVECTION OVER
THE NW ZONES WILL CONTINUE TO TRACK EAST ACROSS THE NORTHERN TWO
ROWS OF COUNTIES THROUGH THE LATE EVENING HOURS. AGAIN MARGINALLY
SEVERE HAIL IS THE MAIN THREAT WITH THESE ELEVATED STORMS...BUT
SUB CLOUD EVAPORATION MAY PROMOTE A LOW WIND THREAT AS WELL.
TR.92
&&
.PREV DISCUSSION... /ISSUED 315 PM CDT THU APR 19 2012/
THE NEXT 24 HOURS APPEAR TO BE THE MOST ACTIVE OVER THE NEXT 7
DAYS. THIS AFTERNOON A COLD FRONT EXTENDS ACROSS CENTRAL KANSAS
INTO WESTERN OKLAHOMA AND INTO THE TEXAS PANHANDLE. A DRYLINE IS
LOCATED ALONG A LINE FROM A SURFACE LOW NEAR CHILDRESS TO BIG
SPRING AND INTO THE BIG BEND REGION. A S/W TROF CURRENTLY DIGGING
ACROSS MONTANA AND WYOMING WILL DEEPEN OVER THE NEXT 12 HOURS IN
RESPONSE TO UPSTREAM RIDGE AMPLIFICATION OVER THE WEST COAST.
LATER TONIGHT...THE COLD FRONT WILL SLIDE FARTHER SOUTH AS MAIN
SURFACE LOW OVER THE MIDWEST CONTINUES NORTHEAST. THE ATMOSPHERE
ACROSS NORTH TEXAS AND SOUTHERN OKLAHOMA IS UNSTABLE HOWEVER IT
REMAINS STRONGLY CAPPED TO SURFACE BASED CONVECTION AND IS
EXPECTED TO REMAIN SO FOR MUCH OF THE EVENING. AS HEIGHT
FALLS/LARGE SCALE FORCING FOR ASCENT CONTINUES TO OVERSPREAD THE
SOUTHERN PLAINS TONIGHT...FORCING ALONG THE FRONT IS EXPECTED TO
INCREASE AND BECOME SUFFICIENT FOR THUNDERSTORMS TO DEVELOP
PRIMARILY ACROSS THE FAR NORTHWEST COUNTIES. FORECAST SOUNDINGS
ACROSS NORTHWEST PORTIONS OF THE CWA INDICATE THAT PARCELS FORCED
BETWEEN 800-700MB WILL HAVE LITTLE INHIBITION BETWEEN 10 PM AND
MIDNIGHT. SHEAR PROFILES WILL SUPPORT SUPERCELL STRUCTURES WITH
ANY STORMS THAT CAN DEVELOP DURING THIS TIME...HOWEVER THE PRIMARY
SEVERE WEATHER THREAT WILL BE LARGE HAIL GIVEN THE NEARLY DRY
ADIABATIC MID LEVEL LAPSE RATES AND HIGH LCL/S. FARTHER SOUTH NEAR
THE METROPLEX...STRONG INHIBITION WILL LIKELY REMAIN IN PLACE AND
CONVECTION WILL LIKELY HAVE TO WAIT ON THE FRONT. WILL HAVE THE
HIGHEST POPS RIGHT ALONG THE RED RIVER TAPERING OFF QUICKLY TO THE
SOUTH FOR TONIGHT.
COLD FRONT WILL MOVE THROUGH NORTH TEXAS TOMORROW MORNING WITH
CAPPING ERODING BY THIS TIME. SCATTERED SHOWERS AND THUNDERSTORMS
ARE EXPECTED RIGHT ALONG AND BEHIND THE FRONT. BEST CHANCES WILL
BE ACROSS THE NORTHEAST AND EAST DURING THE MORNING...THEN SHIFT
TO THE SOUTHEAST COUNTIES BY EARLY AFTERNOON AS THE FRONT
PROGRESSES SOUTHWARD. RAIN AND THUNDERSTORMS WILL CLEAR THE CWA BY
TOMORROW EVENING WITH HIGH PRESSURE BUILDING IN AND COOLER
TEMPERATURES EXPECTED. HIGHS ON SATURDAY WILL ONLY BE IN THE LOW
70S WITH LOWS IN THE MID TO UPPER 40S.
THE WEEKEND AND MUCH OF NEXT WEEK LOOKS VERY QUIET WITH LITTLE
CHANCE FOR RAIN AND PLEASANT TEMPERATURES. MID LEVEL RIDGING LOOKS
LIKE IT WILL REMAIN IN PLACE FOR SEVERAL DAYS. THE GFS DOES INDICATE
AN AXIS OF MOISTURE AND INSTABILITY WORKING NORTH INTO THE SOUTHERN
PLAINS BY MIDWEEK WITH MODERATE NORTHWEST FLOW ALOFT. AT THIS TIME
SEE NO SIGNIFICANT SYSTEM THAT WILL BE SUFFICIENT TO INITIATE
CONVECTION BUT WILL CONTINUE TO MONITOR.
DUNN
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 60 70 47 71 50 / 30 60 5 0 0
WACO, TX 62 71 45 73 44 / 20 50 5 0 0
PARIS, TX 58 66 46 69 47 / 50 60 10 0 0
DENTON, TX 58 67 45 69 48 / 40 50 5 0 0
MCKINNEY, TX 60 68 46 70 48 / 40 60 5 0 0
DALLAS, TX 61 70 47 71 50 / 30 60 5 0 0
TERRELL, TX 60 69 45 72 46 / 20 60 5 0 0
CORSICANA, TX 62 71 47 73 48 / 20 60 10 0 0
TEMPLE, TX 62 74 46 74 46 / 20 50 10 0 0
MINERAL WELLS, TX 58 70 44 72 46 / 40 40 5 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/92
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1024 PM EDT SAT APR 21 2012
.SYNOPSIS...
A DEEP AREA OF LOW PRESSURE ALOFT AND AT THE SURFACE WILL MOVE
FROM THE SOUTHEAST U.S. NORTHWARD ALONG THE EAST COAST THROUGH
MONDAY. A VARIETY OF INCLEMENT WEATHER WILL ACCOMPANY THIS SYSTEM
DURING THE NEXT SEVERAL DAYS...CONSISTING OF SHOWERS AND STORMS
ACROSS THE PIEDMONT TONIGHT...THEN WIDESPREAD RAIN SUNDAY.
CONSIDERABLY COLDER AIR WILL WRAP AROUND THE BACK SIDE OF THE
SYSTEM...WITH ACCUMULATING SNOW POSSIBLE BY EARLY MONDAY ACROSS
THE CENTRAL AND NORTHERN APPALACHIANS.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 815 PM EDT SATURDAY...
NOT A LOT OF CHANGE TO THE GOING FORECAST TONIGHT WITH THE SURFACE
COLD FRONT NOW ACROSS THE FAR SE WHERE THE PRE-FRONTAL BAND OF
CONVECTION HAS BASICALLY COME TO A HALT. LATEST HRRR AND LOCAL WRF
TEND TO DEVELOP THIS AXIS OF SHRA/TSRA A LITTLE MORE TO THE SE
THRU MIDNIGHT BEFORE BACKING STARTS OVERRUNNING THE BOUNDARY
OVERNIGHT AS THE GULF LOW STARTS TO WORK NE UP THE COAST BY
MORNING. ALTHO CONVECTION REMAINS RATHER SHALLOW OVER THE
SE...WILL NEED TO WATCH FOR TRAINING OF CELLS PENDING JUST HOW
MUCH THE COVERAGE DECREASES WITH LOSS OF HEATING AS LATEST SPC
MESO ANALYSIS SHOWS BEST CAPE NOW JUST SE OF THE CWA. THUS DID ADD
A COUPLE HOURS OF HVY RAIN MENTION...MAINLY ACROSS SOUTHSIDE VA/NW
NC PIEDMONT INTO LATE THIS EVENING...WITH POPS LOWERING TO LIKELYS
BEFORE RATCHETING BACK UP TO CATEGORICAL AS PRECIP STARTS TO HEAD
BACK TO THE NNW AFTER MIDNIGHT. MAINLY RUNNING WITH CHANCE TO
SLIGHT POPS ELSW WITH A FEW SHRA/ISOLD -TSRA BANDS LEFTOVER ALONG
THE SRN BLUE RIDGE PER A WEAK SURFACE WAVE NEAR CLT IN BETWEEN
THE SFC AND 85H FRONT STILL BACK IN SE WVA. APPEARS STEADIER RAIN
WONT REDEVELOP OUTSIDE OF THE SE UNTIL TOWARD DAYBREAK WHEN DEEPER
EASTERLY FLOW ESTABLISHES WITH THE HEAVIEST CLOSER TO THE RESIDUAL
FRONT AND PERHAPS IN A DEFORMATION ZONE FARTHER WEST ACROSS THE
MOUNTAINS. OTRW GOING LOW TEMPS LOOK ABOUT ON TRACK AS LOW LEVEL
COOL ADVECTION OOZES IN ALLOWING MOST LOCATIONS EXCEPT THE FAR SE
TO FALL INTO THE 40S BY MORNING.
PREVIOUS DISCUSSION AS OF 350 PM EDT SATURDAY...
SCATTERED SHOWERS AND STORMS WILL CONTINUE MOVING EAST THROUGH
THIS AFTERNOON...EVENTUALLY TO BE REPLACED BY A MORE STEADY
STRATIFORM BEHIND THE COLD FRONT WHICH HAS SLOWED DOWN
CONSIDERABLY OVER THE NEW RIVER AND ROANOKE VALLEYS. WINDS MAY
GUST TO 30 MPH WITH ANY THUNDERSTORMS. BEST CHANCE FOR STRONG
STORMS REMAINS IN THE LYH/DAN/SIF CORRIDOR AS THOSE SPOTS GOT
CLOSE TO 80F TODAY BEFORE CLOUDS ARRIVED WITH MID 50S DEWPOINTS.
SOME OF THE CLUSTERS NOW MERGING IN NW NC MAY STRENGTHEN AS THEY
TOUCH THE 1K J/KG CAPE AND 35 M/S 0-6 KM SHEAR WHICH RESIDES EAST
OF THE BLUE RIDGE. BIGGEST THREAT WILL BE GUSTY WINDS...ALTHOUGH
SOME PEA SIZED HAIL WAS REPORTED WITH STORMS OVER HILLSVILLE A FEW
HOURS AGO. INSTABILITY WANES THIS EVENING AS FRONT SLIDES
EAST...WITH A BREAK IN THE PRECIP. BUT STRONG SURFACE LOW WITH
STOUT UPPER WAVE MOVES UP THE COAST SPREADING STRATIFORM RAIN
ACROSS THE ENTIRE CWA BY 12Z/8A SUNDAY. RAIN MAY BE HVY AT TIMES
LYH/DAN AND POINTS EAST WITH POSSIBLY AN INCH OF RAIN DURING THE
DAYTIME HOURS SUNDAY. PUT HVY RAIN IN THE WX GRIDS. ALSO TIGHT
PRESSURE GRADIENT COULD CAUSE LYH TO GUST TO 30 MPH FROM THE NE
MIDDAY. INC POPS ACROSS THE CWA. MORNING TEMPS WILL LIKELY BE
HIGHS FOR THE DAY...SO WENT WITH TEMPS SLOWLY FALLING DURING THE
DAY WITH IMPRESSIVE DEEP N TO NE FLOW AND PRECIP AL DAY. TEMPS
WILL PROBABLY BE IN THE MID TO UPPER 40S TOMORROW AFTERNOON AFTER
MORNING MAX T...ALTHOUGH WARMER MARITIME AIR MAY KEEP SOUTHSIDE IN
THE 50S DURING THE DAY. NW WINDS DEVELOPING LATE AND DOWNSLOPING
COULD ALSO ALLOW NW NC TO GUST TO 30 MPH LATE DAY. AN INCH OR TWO
OF RAIN MAY FALL TOTAL TONIGHT THROUGH SUN NIGHT IN THE PIEDMONT
AND SOUTHSIDE.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 315 PM EDT SATURDAY...
GOING TO SEE A TRANSITION TO COLDER AND WINDY WEATHER THIS PERIOD.
MODELS SHOW ENOUGH AGREEMENT IN TRACK OF THE SFC/UPPER LOW THAT
SUNDAY EVENING SHOWERS WILL BE FALLING ACROSS A GOOD DEAL OF THE
AREA...BUT STARTING TO DRY OUT IN THE SOUTHWEST. AS THE UPPER LOW
DEEPENS OVER WRN VIRGINIA LATE SUNDAY NIGHT...8H TEMPS DROP TO -2 IN
THE MTNS WHERE RAIN SHOWERS WILL CHANGE TO SNOW SHOWERS. ATTM...MADE
SOME UPWARD ADJUSTMENTS ON ACCUMULATION...BUT EXPECT IT TO STAY
BELOW ANY ADVISORY LEVELS...AS THE GROUND WILL BE WARM...AND SPEED
OF SYSTEM MAY LIMIT PERIOD OF STRONG LIFT/COLDER TEMPS STAYING
OVERHEAD. ATTM...WILL SEE AN INCH OR MORE ACROSS THE HIGHER
ELEVATIONS (ABOVE 4000 FEET) LATE SUNDAY NIGHT-MONDAY MORNING. THIS
INCLUDES MOUNT ROGERS...BURKES GARDEN AREA...AND THE HIGHLANDS OF
BATH...WEST INTO GREENBRIER COUNTY. GIVEN AMOUNT OF QPF...WRN
GREENBRIER STANDS THE BEST SHOT OF SEEING SEVERAL INCHES OF WET
SNOW.
THIS SYSTEM SWINGS INLAND SOME MONDAY AND DEEPENS TO A 986 LOW ACROSS
NEW YORK. MODELS SHOW ENOUGH OF A TIGHT GRADIENT AND 8H WINDS OF
45-50 KNOTS THAT WILL BE BUMPING WIND GUSTS UP TO 30+ KNOTS. WOULD
NOT BE SURPRISED TO SEE A WIND ADVISORY...MAYBE A HIGH WIND WARNING
FOR A PERIOD OF TIME MONDAY....BUT WILL WAIT FOR MORE CONSISTENCY IN
MODELS AND ANOTHER RUN OR TWO BEFORE ISSUING HEADLINES IF NEEDED.
THE SNOW THREAT/WIND THREAT IS MENTIONED IN THE HAZARDOUS WEATHER
OUTLOOK.
THE SHOWERY CONDITIONS WILL BE STARTING TO WIND DOWN DURING THE AFTN
MONDAY AS MOISTURE STARTS TO BECOME MORE LIMITED. ANOTHER VORT
TAKING A SEWD TURN AROUND THE UPPER LOW MONDAY NIGHT WILL KEEP A FEW
RAIN/SNOW SHOWERS FALLING INTO THE MTNS OF SE WV. TEMPS SLIP INTO
THE UPPER 20S MON NIGHT IN THE MTNS TO THE MID TO UPPER 30S OUT
EAST. WINDS WILL FROST FROM FORMING...BUT DEFINITELY COULD SEE A
FREEZE IN THE MOUNTAINS.
TUESDAY...THERE STILL EXISTS A GRADIENT BETWEEN THE DEPARTING LOW
INTO CANADA AND HIGH PRESSURE IN THE GULF OF MEXICO. ANOTHER
SHORTWAVE MOVES ACROSS TUESDAY AFTN AND COULD SEE WEST WINDS GUSTING
TO 25 - 35 MPH AT TIMES.
AS FOR TEMPS...MADE IT COOLER IN THE MOUNTAINS MONDAY WITH
40S...SOME UPPER 30S HIGHER ELEVATIONS TO 50S EAST PER DOWNSLOPE.
TUESDAY WILL BE MILDER IN THE EAST WITH 60S AND FLOW TURNING MORE
WEST...WHILE THE MOUNTAINS STAY IN THE 50S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 130 PM EDT SATURDAY...
THE ECMWF AND GFS DEPICT A CLIPPER TRACKING SOUTHEASTWARD FROM THE
UPPER MIDWEST TO THE OHIO RIVER VALLEY FOR TUESDAY NIGHT INTO
WEDNESDAY. SOME SHOWERS MAY SPREAD AHEAD OF IT AND REACH THE WESTERN
PART OF THE CWA BY WEDNESDAY MORNING...AND THE PIEDMONT LATER IN
THE DAY. THE CLIPPER WILL PASS OVER THE CWA DURING WEDNESDAY NIGHT
INTO THURSDAY...BUT THE MODELS DIVERGE SIGNIFICANTLY WITH THE
DETAILS. THE ECMWF SHOWS EASTERLY SFC WINDS AND HIGHER QPF FROM
THE CLIPPER...WHILE THE GFS SHOWS WESTERLY SFC WINDS AND LOWER QPF.
IF THE ECMWF VERIFIES...A COLD WEDGE WOULD FORM...AND CAUSE THURSDAY
TEMPERATURES TO BE 10 TO 20 DEGREES COOLER THAN THE GFS. GIVEN THIS
LARGE DISCREPANCY...CHANCE POPS WERE INTRODUCED FOR THURSDAY...AND
TEMPERATURES WERE BUMPED DOWNWARD BUT KEPT IN THE MIDDLE OF BOTH
SOLUTIONS UNTIL BETTER AGREEMENT IS ESTABLISHED IN FUTURE RUNS.
THE CLIPPER SHOULD EXIT THE CWA AND HEAD SOUTHWARD THROUGH THE
CAROLINAS BY FRIDAY. MEANWHILE...HIGH PRESSURE WILL BUILD OVER THE
MID ATLANTIC FROM THE NORTHWEST. THIS SITUATION SHOULD ALLOW
PLEASANT AND SEASONABLE CONDITIONS FOR THE START OF NEXT WEEKEND.
BOTH THE ECMWF AND GFS KEEP THIS AREA OF HIGH PRESSURE NORTH OF THE
CWA AND SLIDE IT OFF THE EAST COAST BY SUNDAY...WHICH WILL PROMPT A
WARMING TREND AND INCREASING DEWPOINTS FROM RETURN SOUTHERLY FLOW.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
AS OF 645 PM EDT SATURDAY...
LEADING EDGE OF CONVECTION ALONG THE FRONT NOW WORKING TOWARD KDAN
AND EXPECT A FEW STRONGER CELLS TO AFFECT LOCATIONS FROM SOUTH OF
KLYH TO AROUND KDAN IN THE NEXT HOUR OR TWO. COULD SEE WIND GUSTS
TO 35 KTS AROUND KDAN BEFORE DARK AS THE STORMS PASS THROUGH. ELSW
STILL LOOKING AT CLUSTERS OF SHRA/-RA AROUND KLYH WITH SOME SPOTTY
RESIDUAL SHRA LIKELY TO AFFECT KROA IN THE NEXT COUPLE OF HOURS...
BUT MAINLY VFR OUTSIDE OF ANY HEAVIER LINGERING SHRA.
OTRW SHRA WILL TREND TO SPOTTY -RA OR JUST CLOUDY SKIES BEHIND
THE FRONT THIS EVENING AS THE MAIN BAND OF PRE-FROTNAL COVECTION
HEADS TO THE SE. EXPECT CIGS TO REMAIN MOSTLY VFR BEHIND THE FRONT
EXCEPT AT KBLF WHERE UPSLOPE FLOW WILL TEND TO KEEP PERSISTENT
MVFR TO IFR LOW CIGS IN PLACE. THEN...A LARGE RAIN SHIELD WILL
SPREAD FROM KDAN/KLYH...TO KROA/KBCB LATE TONIGHT AS STRONG LOW
PRESSURE MOVES UP THE COAST. THE DEVELOPING EASTERLY COMPONENT
SHOULD SEND CIGS TO IFR AT ALL TERMINALS SUNDAY MORNING. IFR
CONDS...WITH POSSIBLY HVY RAIN AT TIMES KLYH/KDAN WILL PERSIST
THROUGH MUCH OF SUNDAY THEN ENDING SUNDAY NIGHT. WINDS WILL BACK
TO THE N THEN NW AND BECOME GUSTY SUNDAY INTO SUNDAY NIGHT WHICH
SHOULD BEGIN TO IMPROVE THE PERSISTENT IFR CIGS. A MIX OF RAIN AND
SNOW SHOWERS WILL AFFECT THE KLWB/KBLF CORRIDOR LATE SUNDAY NIGHT
AND INTO MONDAY. SOME 40-45 KT WIND GUSTS ARE NOT OUT OF THE
QUESTION KROA/KBCB WITH STRNG DOWNSLOPING FLOW INTO MONDAY. CONDS
IMPROVE INTO THE MIDDLE OF NEXT WEEK WITH A CHC FOR RAIN AND A
POTENTIAL WEDGE INTO THURSDAY WITH IFR CIGS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KM/RAB
NEAR TERM...JH/KM
SHORT TERM...WP
LONG TERM...PM
AVIATION...JH/KM/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
911 PM EDT SAT APR 21 2012
.SYNOPSIS...
A DEEP AREA OF LOW PRESSURE ALOFT AND AT THE SURFACE WILL MOVE
FROM THE SOUTHEAST U.S. NORTHWARD ALONG THE EAST COAST THROUGH
MONDAY. A VARIETY OF INCLEMENT WEATHER WILL ACCOMPANY THIS SYSTEM
DURING THE NEXT SEVERAL DAYS...CONSISTING OF SHOWERS AND STORMS
ACROSS THE PIEDMONT TONIGHT...THEN WIDESPREAD RAIN SUNDAY.
CONSIDERABLY COLDER AIR WILL WRAP AROUND THE BACK SIDE OF THE
SYSTEM...WITH ACCUMULATING SNOW POSSIBLE BY EARLY MONDAY ACROSS
THE CENTRAL AND NORTHERN APPALACHIANS.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 815 PM EDT SATURDAY...
NOT A LOT OF CHANGE TO THE GOING FORECAST TONIGHT WITH THE SURFACE
COLD FRONT NOW ACROSS THE FAR SE WHERE THE PRE-FRONTAL BAND OF
CONVECTION HAS BASICALLY COME TO A HALT. LATEST HRRR AND LOCAL WRF
TEND TO DRIFT THIS AXIS OF SHRA/TSRA A LITTLE MORE TO THE SE THRU
MIDNIGHT BEFORE BACKING STARTS OVERRUNNING THE BOUNDARY OVERNIGHT
AS THE GULF LOW STARTS TO WORK NE UP THE COAST BY MORNING. ALTHO
CONVECTION REMAINS RATHER SHALLOW OVER THE SE...WILL NEED TO
WATCH FOR TRAINING OF CELLS PENDING JUST HOW MUCH THE COVERAGE
DECREASES WITH LOSS OF HEATING AS LATEST SPC MESO ANALYSIS SHOWS
BEST CAPE NOW JUST SE OF THE CWA. THUS DID ADD A COUPLE HOURS OF
HVY RAIN MENTION...MAINLY ACROSS SOUTHSIDE VA/NW NC PIEDMONT INTO
LATE THIS EVENING...WITH POPS LOWERING TO LIKELYS BEFORE
RATCHETING BACK UP TO CATEGORICAL AS PRECIP STARTS TO HEAD BACK TO
THE NNW AFTER MIDNIGHT. MAINLY RUNNING WITH CHANCE TO SLIGHT POPS
ELSW WITH A FEW SHRA/ISOLD -TSRA BANDS LEFTOVER ALONG THE SRN BLUE
RIDGE IN BETWEEN THE SFC AND 85H FRONT STILL BACK IN SE WVA.
APPEARS STEADIER RAIN WONT REDEVELOP OUTSIDE OF THE SE UNTIL
TOWARD DAYBREAK WHEN DEEPER EASTERLY FLOW ESTABLISHES WITH THE
HEAVIEST CLOSER TO THE RESIDUAL FRONT. GOING LOW TEMPS LOOK ABOUT
ON TRACK AS LOW LEVEL COOL ADVECTION OOZES IN ALLOWING MOST
LOCATIONS EXCEPT THE FAR SE TO FALL INTO THE 40S BY MORNING.
PREVIOUS DISCUSSION AS OF 350 PM EDT SATURDAY...
SCATTERED SHOWERS AND STORMS WILL CONTINUE MOVING EAST THROUGH
THIS AFTERNOON...EVENTUALLY TO BE REPLACED BY A MORE STEADY
STRATIFORM BEHIND THE COLD FRONT WHICH HAS SLOWED DOWN
CONSIDERABLY OVER THE NEW RIVER AND ROANOKE VALLEYS. WINDS MAY
GUST TO 30 MPH WITH ANY THUNDERSTORMS. BEST CHANCE FOR STRONG
STORMS REMAINS IN THE LYH/DAN/SIF CORRIDOR AS THOSE SPOTS GOT
CLOSE TO 80F TODAY BEFORE CLOUDS ARRIVED WITH MID 50S DEWPOINTS.
SOME OF THE CLUSTERS NOW MERGING IN NW NC MAY STRENGTHEN AS THEY
TOUCH THE 1K J/KG CAPE AND 35 M/S 0-6 KM SHEAR WHICH RESIDES EAST
OF THE BLUE RIDGE. BIGGEST THREAT WILL BE GUSTY WINDS...ALTHOUGH
SOME PEA SIZED HAIL WAS REPORTED WITH STORMS OVER HILLSVILLE A FEW
HOURS AGO. INSTABILITY WANES THIS EVENING AS FRONT SLIDES
EAST...WITH A BREAK IN THE PRECIP. BUT STRONG SURFACE LOW WITH
STOUT UPPER WAVE MOVES UP THE COAST SPREADING STRATIFORM RAIN
ACROSS THE ENTIRE CWA BY 12Z/8A SUNDAY. RAIN MAY BE HVY AT TIMES
LYH/DAN AND POINTS EAST WITH POSSIBLY AN INCH OF RAIN DURING THE
DAYTIME HOURS SUNDAY. PUT HVY RAIN IN THE WX GRIDS. ALSO TIGHT
PRESSURE GRADIENT COULD CAUSE LYH TO GUST TO 30 MPH FROM THE NE
MIDDAY. INC POPS ACROSS THE CWA. MORNING TEMPS WILL LIKELY BE
HIGHS FOR THE DAY...SO WENT WITH TEMPS SLOWLY FALLING DURING THE
DAY WITH IMPRESSIVE DEEP N TO NE FLOW AND PRECIP AL DAY. TEMPS
WILL PROBABLY BE IN THE MID TO UPPER 40S TOMORROW AFTERNOON AFTER
MORNING MAX T...ALTHOUGH WARMER MARITIME AIR MAY KEEP SOUTHSIDE IN
THE 50S DURING THE DAY. NW WINDS DEVELOPING LATE AND DOWNSLOPING
COULD ALSO ALLOW NW NC TO GUST TO 30 MPH LATE DAY. AN INCH OR TWO
OF RAIN MAY FALL TOTAL TONIGHT THROUGH SUN NIGHT IN THE PIEDMONT
AND SOUTHSIDE.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 315 PM EDT SATURDAY...
GOING TO SEE A TRANSITION TO COLDER AND WINDY WEATHER THIS PERIOD.
MODELS SHOW ENOUGH AGREEMENT IN TRACK OF THE SFC/UPPER LOW THAT
SUNDAY EVENING SHOWERS WILL BE FALLING ACROSS A GOOD DEAL OF THE
AREA...BUT STARTING TO DRY OUT IN THE SOUTHWEST. AS THE UPPER LOW
DEEPENS OVER WRN VIRGINIA LATE SUNDAY NIGHT...8H TEMPS DROP TO -2 IN
THE MTNS WHERE RAIN SHOWERS WILL CHANGE TO SNOW SHOWERS. ATTM...MADE
SOME UPWARD ADJUSTMENTS ON ACCUMULATION...BUT EXPECT IT TO STAY
BELOW ANY ADVISORY LEVELS...AS THE GROUND WILL BE WARM...AND SPEED
OF SYSTEM MAY LIMIT PERIOD OF STRONG LIFT/COLDER TEMPS STAYING
OVERHEAD. ATTM...WILL SEE AN INCH OR MORE ACROSS THE HIGHER
ELEVATIONS (ABOVE 4000 FEET) LATE SUNDAY NIGHT-MONDAY MORNING. THIS
INCLUDES MOUNT ROGERS...BURKES GARDEN AREA...AND THE HIGHLANDS OF
BATH...WEST INTO GREENBRIER COUNTY. GIVEN AMOUNT OF QPF...WRN
GREENBRIER STANDS THE BEST SHOT OF SEEING SEVERAL INCHES OF WET
SNOW.
THIS SYSTEM SWINGS INLAND SOME MONDAY AND DEEPENS TO A 986 LOW ACROSS
NEW YORK. MODELS SHOW ENOUGH OF A TIGHT GRADIENT AND 8H WINDS OF
45-50 KNOTS THAT WILL BE BUMPING WIND GUSTS UP TO 30+ KNOTS. WOULD
NOT BE SURPRISED TO SEE A WIND ADVISORY...MAYBE A HIGH WIND WARNING
FOR A PERIOD OF TIME MONDAY....BUT WILL WAIT FOR MORE CONSISTENCY IN
MODELS AND ANOTHER RUN OR TWO BEFORE ISSUING HEADLINES IF NEEDED.
THE SNOW THREAT/WIND THREAT IS MENTIONED IN THE HAZARDOUS WEATHER
OUTLOOK.
THE SHOWERY CONDITIONS WILL BE STARTING TO WIND DOWN DURING THE AFTN
MONDAY AS MOISTURE STARTS TO BECOME MORE LIMITED. ANOTHER VORT
TAKING A SEWD TURN AROUND THE UPPER LOW MONDAY NIGHT WILL KEEP A FEW
RAIN/SNOW SHOWERS FALLING INTO THE MTNS OF SE WV. TEMPS SLIP INTO
THE UPPER 20S MON NIGHT IN THE MTNS TO THE MID TO UPPER 30S OUT
EAST. WINDS WILL FROST FROM FORMING...BUT DEFINITELY COULD SEE A
FREEZE IN THE MOUNTAINS.
TUESDAY...THERE STILL EXISTS A GRADIENT BETWEEN THE DEPARTING LOW
INTO CANADA AND HIGH PRESSURE IN THE GULF OF MEXICO. ANOTHER
SHORTWAVE MOVES ACROSS TUESDAY AFTN AND COULD SEE WEST WINDS GUSTING
TO 25 - 35 MPH AT TIMES.
AS FOR TEMPS...MADE IT COOLER IN THE MOUNTAINS MONDAY WITH
40S...SOME UPPER 30S HIGHER ELEVATIONS TO 50S EAST PER DOWNSLOPE.
TUESDAY WILL BE MILDER IN THE EAST WITH 60S AND FLOW TURNING MORE
WEST...WHILE THE MOUNTAINS STAY IN THE 50S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 130 PM EDT SATURDAY...
THE ECMWF AND GFS DEPICT A CLIPPER TRACKING SOUTHEASTWARD FROM THE
UPPER MIDWEST TO THE OHIO RIVER VALLEY FOR TUESDAY NIGHT INTO
WEDNESDAY. SOME SHOWERS MAY SPREAD AHEAD OF IT AND REACH THE WESTERN
PART OF THE CWA BY WEDNESDAY MORNING...AND THE PIEDMONT LATER IN
THE DAY. THE CLIPPER WILL PASS OVER THE CWA DURING WEDNESDAY NIGHT
INTO THURSDAY...BUT THE MODELS DIVERGE SIGNIFICANTLY WITH THE
DETAILS. THE ECMWF SHOWS EASTERLY SFC WINDS AND HIGHER QPF FROM
THE CLIPPER...WHILE THE GFS SHOWS WESTERLY SFC WINDS AND LOWER QPF.
IF THE ECMWF VERIFIES...A COLD WEDGE WOULD FORM...AND CAUSE THURSDAY
TEMPERATURES TO BE 10 TO 20 DEGREES COOLER THAN THE GFS. GIVEN THIS
LARGE DISCREPANCY...CHANCE POPS WERE INTRODUCED FOR THURSDAY...AND
TEMPERATURES WERE BUMPED DOWNWARD BUT KEPT IN THE MIDDLE OF BOTH
SOLUTIONS UNTIL BETTER AGREEMENT IS ESTABLISHED IN FUTURE RUNS.
THE CLIPPER SHOULD EXIT THE CWA AND HEAD SOUTHWARD THROUGH THE
CAROLINAS BY FRIDAY. MEANWHILE...HIGH PRESSURE WILL BUILD OVER THE
MID ATLANTIC FROM THE NORTHWEST. THIS SITUATION SHOULD ALLOW
PLEASANT AND SEASONABLE CONDITIONS FOR THE START OF NEXT WEEKEND.
BOTH THE ECMWF AND GFS KEEP THIS AREA OF HIGH PRESSURE NORTH OF THE
CWA AND SLIDE IT OFF THE EAST COAST BY SUNDAY...WHICH WILL PROMPT A
WARMING TREND AND INCREASING DEWPOINTS FROM RETURN SOUTHERLY FLOW.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AS OF 645 PM EDT SATURDAY...
LEADING EDGE OF CONVECTION ALONG THE FRONT NOW WORKING TOWARD KDAN
AND EXPECT A FEW STRONGER CELLS TO AFFECT LOCATIONS FROM SOUTH OF
KLYH TO AROUND KDAN IN THE NEXT HOUR OR TWO. COULD SEE WIND GUSTS
TO 35 KTS AROUND KDAN BEFORE DARK AS THE STORMS PASS THROUGH. ELSW
STILL LOOKING AT CLUSTERS OF SHRA/-RA AROUND KLYH WITH SOME SPOTTY
RESIDUAL SHRA LIKELY TO AFFECT KROA IN THE NEXT COUPLE OF HOURS...
BUT MAINLY VFR OUTSIDE OF ANY HEAVIER LINGERING SHRA.
OTRW SHRA WILL TREND TO SPOTTY -RA OR JUST CLOUDY SKIES BEHIND
THE FRONT THIS EVENING AS THE MAIN BAND OF PRE-FROTNAL COVECTION
HEADS TO THE SE. EXPECT CIGS TO REMAIN MOSTLY VFR BEHIND THE FRONT
EXCEPT AT KBLF WHERE UPSLOPE FLOW WILL TEND TO KEEP PERSISTENT
MVFR TO IFR LOW CIGS IN PLACE. THEN...A LARGE RAIN SHIELD WILL
SPREAD FROM KDAN/KLYH...TO KROA/KBCB LATE TONIGHT AS STRONG LOW
PRESSURE MOVES UP THE COAST. THE DEVELOPING EASTERLY COMPONENT
SHOULD SEND CIGS TO IFR AT ALL TERMINALS SUNDAY MORNING. IFR
CONDS...WITH POSSIBLY HVY RAIN AT TIMES KLYH/KDAN WILL PERSIST
THROUGH MUCH OF SUNDAY THEN ENDING SUNDAY NIGHT. WINDS WILL BACK
TO THE N THEN NW AND BECOME GUSTY SUNDAY NIGHT WHICH SHOULD BEGIN
TO IMPROVE THE PERSISTENT IFR CIGS. A MIX OF RAIN AND SNOW SHOWERS
WILL AFFECT THE KLWB/KBLF CORRIDOR LATE SUNDAY NIGHT AND INTO
MONDAY. SOME 40-45 KT WIND GUSTS ARE NOT OUT OF THE QUESTION
KROA/KBCB WITH STRNG DOWNSLOPING FLOW INTO MONDAY. CONDS IMPROVE
INTO THE MIDDLE OF NEXT WEEK WITH A CHC FOR RAIN AND A POTENTIAL
WEDGE INTO THURSDAY WITH IFR CIGS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KM/RAB
NEAR TERM...JH/KM
SHORT TERM...WP
LONG TERM...PM
AVIATION...JH/KM/RAB
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1040 PM PDT Thu Apr 19 2012
.SYNOPSIS...
Widespread light rain will overspread the region tonight...with
unsettled...breezy and showery conditions lingering through
Friday. Warmer than average temperatures are expected over the
weekend with mostly dry conditions Saturday but with the
possibility of afternoon thunderstorms by Sunday and Monday. A
return to more seasonal temperatures is expected as a cold front
arrives Tuesday.
&&
.DISCUSSION...
Evening Update: A very moist storm system is bearing down on
the Inland NW with a 1.2" precipitable water fetch slamming into
the coast and warm sector rain already observed or soon to be
observed at most observations. The heaviest rainfall as of 830PM
was noted across the central Columbia Basin along the leading warm
front where we are observing rainfall rates of 0.02-0.05"/hour.
The 02z RUC appeared to capture this enhanced pcpn well on its
295K isentropic charts which in conjunction with the latest radar
loop will continue to expand and march toward the Idaho Panhandle
well before 06z. As such, forecast PoPs have been raised into the
80-100% range with QPF amts incr near a tenth across the eastern
Columbia Basin...Palouse...and West Plains. Behind the warm front,
there is some midlevel drying and backing of winds more to the sw
from s allowing a pseudo rain shadow in the lee of the central
Cascades and Wenatchee area and despite the continued rain
falling, ceilings have been on the rise during the last few hours.
This shadow will continue to incr overnight as pressure falls
strengthen over southern Alberta we incr the westerly component to
midlevel flow...however with the main surface low driving this
moisture and frontal structures into the region lifting northward
along the central BC coast...the main cool occlusion never really
dips south of highway 2 and basically gets hung up across the
region in a sw to ne fashion leading to low confidence that
communities in the lee of the Cascades will remain completely dry.
There is strong agreement that the incr west/southwest flow will
lead to a very wet 6-12z period for the Idaho Panhandle and far
eastern reaches of WA due to enhanced upsloping component. As
such, I have trend QPF amts and PoPs upward. The good news is that
we remain in a relative warm sector through much of the event and
we are not expecting surprising convective bands capable of the
1.00" or greater QPF amts were saw with a flooding event over the
Palouse on March 25/26. On that same note, snow levels which are
roughly 5K north to 6-7K ft south are expected to continue to rise
enhancing snowmelt processes...which will lead to rises across
most basins; especially the St Joe where an RVS has been issued.
/sb
&&
.AVIATION...
06Z TAFs: Satellite reveals a rich tap of subtropical moisture
aimed into the region this eveing with rain and IFR/MVFR cigs
likely for most eastern terminals (KGEG-KCOE-KSFF-KCOE).
Steady rain has ended frm KMWH-KEAT but strengthening W flow will
continue to slop light showers across the Cascade crest and
across these terminals through early morning. The main cold front
with this system becomes draped across the region in a sw to ne
fashion on friday making very little progression toward the south
keeping plenty of mid and high level moisure streaming through the
region. In the lower-levels...low pressure deepens east of the
Divide incr sw pressure gradients yielding abundant upsloping
showers frm KCQV-KPUW and all points east. Additionally...strong
to gusty winds winds of 12-22kts with gusts 24-29kts are expected
through much of the aftn. Improving conditions and lighter winds
expected across the region aft 03z. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 43 61 43 65 44 75 / 90 50 20 10 0 10
Coeur d`Alene 43 61 42 65 41 75 / 100 60 20 10 10 10
Pullman 43 62 45 66 42 76 / 90 60 30 20 10 10
Lewiston 48 69 50 73 48 81 / 100 30 20 10 10 10
Colville 42 65 40 67 41 77 / 100 70 10 0 0 0
Sandpoint 42 61 40 62 39 72 / 100 90 20 10 10 10
Kellogg 41 58 42 63 42 73 / 100 90 50 20 10 10
Moses Lake 45 68 43 71 45 79 / 100 10 0 0 0 10
Wenatchee 46 67 45 69 48 76 / 70 10 0 0 0 10
Omak 42 68 35 69 41 77 / 70 10 0 0 0 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1050 PM CDT SAT APR 21 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
MOVING SOUTHEAST OVER THE RED RIVER VALLEY EARLY THIS AFTERNOON...AS
A STRONG SHORTWAVE WITHIN THE LEFT EXIT REGION OF A JET STREAK DIVES
OVER THE NORTHERN MISSISSIPPI VALLEY. ALONG THE 850MB WARM
FRONT...A BAND OF RAIN IS CROSSING THE MINNESOTA/WISCONSIN STATE
BORDER WHILE A MID-LEVEL CLOUD DECK IS MOVING INTO CENTRAL AND
NORTH-CENTRAL WISCONSIN. DRY EAST FLOW OVER THE EASTERN HALF OF THE
STATE HAS BEEN DELAYING THE PROGRESS OF THESE CLOUDS UP UNTIL NOW.
AS THE SURFACE LOW TRACKS SOUTHEAST...SMALL PRECIP CHANCES AND CLOUD
TRENDS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...DECENT SHORTWAVE TROUGH WILL DIVE SE WITHIN THE LEFT EXIT
REGION OF A JET STREAK AND DRIVE A SURFACE LOW OVER THE NORTHERN AND
CENTRAL MISSISSIPPI RIVER VALLEY. THE 850MB THETAE GRADIENT WILL
REMAIN WELL WEST OF THE REGION FOR ANY PRECIP THREAT...BUT WILL SEE
MID AND HIGH CLOUDS ON THE INCREASE FOR THE REST OF THIS AFTERNOON
INTO THIS EVENING. DURING THE OVERNIGHT PERIOD...NE WINDS WILL
ADVECT DRY AIR OUT OF A HUDSON BAY HIGH ACROSS NORTHEAST AND INTO
CENTRAL WISCONSIN...WHERE SHOULD SEE PARTIAL CLEARING AS THE
MID-DECK IS ERODED. IN THE END THOUGH...WILL GO WITH PARTLY TO
MOSTLY CLOUDY SKIES WITH LOWS RANGING FROM THE UPPER 20S NORTH TO
MID 30S SOUTH.
SUNDAY...BEHIND THE DEPARTING SURFACE LOW...A SURFACE TROUGH WILL
HANG BACK ACROSS THE NORTHERN MISSISSIPPI VALLEY. NE WINDS EAST OF
THE SURFACE TROUGH WILL CONTINUE TO FUNNEL IN DRY AIR OVER NORTHEAST
AND CENTRAL WISCONSIN FOR MUCH OF THE MORNING. BUT DURING THE
AFTERNOON...NW WINDS ALOFT WILL START TO PUSH RESIDUAL MOISTURE
ALONG THE TROUGH INTO CENTRAL AND N-C WISCONSIN. SATURATION BECOMES
200-300MB DEEP IN THE AFTERNOON OVER THIS REGION...BUT PROGGED
SOUNDINGS DO NOT SHOW ANY MID-LEVEL INSTABILITY. IN
ADDITION...CANNOT FIND A TRIGGER AND IT ACTUALLY LOOKS LIKE
SHORTWAVE RIDGING TRIES TO BUILD OVER NORTHERN WISCONSIN IN THE
AFTERNOON. AS A RESULT...WILL STICK WITH A DRY FORECAST DESPITE THE
WIDESPREAD SHOWER ACTIVITY UPSTREAM. HIGH TEMPS WILL BE SIMILAR TO
TODAY...MAYBE A DEGREE OR TWO WARMER OVER NE WISCONSIN.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY...TRYING TO SORT OUT
MODEL DIFFERENCES WITH MINOR PCPN CHANCES IS THE MAIN FCST CHALLENGE.
A HIGH AMPLITUDE RIDGE OVER THE ROCKIES AND UPPER LOW OVER THE
EASTERN GREAT LAKES AND NE U.S. WILL DOMINATE THE WEATHER PATTERN FOR
THE BEGINNING OF THE PERIOD. WISCONSIN WILL BE BETWEEN THESE TWO
FEATURES...WITH N-NW FLOW ALOFT. THE PATTERN IS EXPECTED TO
DEAMPLIFY BRIEFLY BY THE MIDDLE OF NEXT WEEK...THEN AMPLIFY AGAIN
LATE IN THE WORK WEEK WITH A STG UPPER RIDGE MOVG INTO THE
NORTHERN PLAINS.
HAVE IGNORED THE SPOTTY QPF SHOWN BY THE MODELS OVER NC WI ON SUNDAY
EVG...AS THERE DOESN`T APPEAR TO BE ANY REAL TRIGGER TO LATCH ONTO.
MODEL TIMESECTIONS DO SHOW QUITE A BIT OF MOISTURE IN THE 850-700 MB
RANGE...SO MOSTLY CLOUDY SKIES LOOK LIKE A GOOD BET. DRY CONDITIONS
WITH PARTLY TO MOSTLY CLOUDY SKIES SHOULD PREVAIL THROUGH MONDAY NIGHT.
ON TUESDAY...HAVE BACKED OFF A BIT ON PCPN CHCS FROM THE PREVIOUS FCST...
BUT DID KEEP A SLIGHT CHC OVER THE SW HALF OF THE CWA. MODELS SHOW
LOW PRESSURE DROPPING SE OUT OF THE NORTHERN PLAINS...WITH A STG
BAROCLINIC ZONE AND SOME INSTABILITY SETTING UP JUST TO OUR SOUTHWEST.
WEAK SFC RIDGING WILL STILL BE IN PLACE OVER NE WI...ALONG WITH VERY
DRY AIR AT 850 MB...SO PULLED POPS THERE ON TUESDAY. CONTINUED
LOW-END POPS ON TUESDAY NIGHT AND WEDNESDAY...AS THE PATTERN DOESN`T
CHANGE MUCH. IF THE RIDGING OVER NE WI ENDS UP BEING A LITTLE
STRONGER...THIS COULD TURN INTO A DRY FCST. EXPECT SEASONABLE
TEMPERATURES DURING THIS PERIOD.
CANADIAN HIGH PRESSURE IS EXPECTED TO DOMINATE ON THU/FRI...WITH DRY
CONDITIONS AND TEMPS A LITTLE BLO NORMAL.
MODEL BLEND GIVES US A CHANCE OF SHOWERS ON FRIDAY NIGHT/SATURDAY...
BUT THE LATEST RUN OF THE ECMWF SEEMS TO BACK OFF ON THIS...AND
CHANGES MAY BE NEEDED WITH SUBSEQUENT FCSTS. CONFIDENCE IS VERY LOW
FOR THIS PORTION OF THE FCST.
&&
.AVIATION...A LOW PRESSURE SYSTEM TRACKING SOUTHEASTWARD OVER
MINNESOTA AND IOWA TONIGHT INTO SUNDAY WILL BE THE FOCUS OF
CONVECTION OVER THE NORTHERN GREAT LAKES AND UPPER MISSISSIPPI
VALLEY REGION. DRY EAST FLOW FROM A HIGH PRESSURE SYSTEM
NORTHEAST OF WISCONSIN WILL CONTINUE TO KEEP PCPN CONFINED OVER
FAR WESTERN WISCONSIN AND AREAS TO THE WEST. A VFR CIG WILL
CONTINUE TO DRIFT INTO CENTRAL WISCONSIN OVERNIGHT AND INTO
SUNDAY...WITH VFR CONDITIONS OVER EASTERN WISCONSIN.
TDH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1000 PM CDT SAT APR 21 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
305 PM CDT SAT APR 21 2012
MAIN FORECAST CHALLENGE IS ON PRECIPITATION CHANCES TONIGHT INTO
EARLY SUNDAY...AND ITS EASTWARD EXTENT INTO WISCONSIN.
18Z WATER VAPOR IMAGERY SHOWS WELL DEFINED SHORTWAVE OVER EASTERN
NORTH DAKOTA...WHILE A SURFACE LOW RESIDES IN THE SAME AREA...WITH A
COLD FRONT TRAILING TO THE SOUTH INTO EASTERN SOUTH DAKOTA AND
EASTERN NEBRASKA. PLUME OF SHOWERS OUT AHEAD OF THIS WAS OCCURRING
FROM THE ARROWHEAD OF MINNESOTA...SOUTHWARD INTO SOUTH CENTRAL
MINNESOTA AND CENTRAL IOWA. SHOWERS HAVE MADE VERY SLOW PROGRESS
EASTWARD WITH A RATHER DRY EASTERLY SURFACE TO 925 MB FLOW.
21.12Z MODELS OFFER SIMILAR SOLUTIONS THROUGH THE PERIOD. IN THE
NEAR TERM...RUC/NAM/GFS ALL SHOW 900MB-700MB BAND OF FRONTOGENETIC
FORCING TO APPROACH THE MISSISSIPPI RIVER THIS EVENING AND THEN
WEAKEN OVERNIGHT AS IT SLIDES SOUTHEAST. ASSOCIATED PRECIPITATION
WILL CONTINUE TO ENCOUNTER DRY LOW LEVEL EASTERLY FLOW OVER
WISCONSIN WHICH WILL LIMIT THE EASTWARD MOVEMENT OF THE SHOWERS.
HIGHEST PROBABILITIES STILL LOOK TO BE WEST OF THE MISSISSIPPI RIVER
TONIGHT...WITH A RATHER SHARP PRECIPITATION GRADIENT ALONG AND JUST
EAST OF THE RIVER. WITH FORCING WEAKENING OVERNIGHT...DID LOWER
PROBABILITIES AFTER MIDNIGHT.
AS UPPER WAVE/SURFACE LOW MOVES AWAY FROM THE AREA SUNDAY...A
LINGERING SURFACE TROUGH WILL EXTEND NORTHWARD INTO SOUTH CENTRAL
MINNESOTA DURING THE MORNING HOURS. WILL KEEP LOWER END
PROBABILITIES ACROSS THE FAR WEST DURING THE MORNING HOURS...BUT
KEEP THINGS DRY AFTER 18Z. UPPER LEVEL RIDGING THEN BUILDS ACROSS
THE AREA MONDAY AND TUESDAY AS SURFACE HIGH MOVES INTO THE AREA.
EVEN WITH THE HIGH OVERHEAD...BOTH THE NAM AND GFS DO SHOW
CONSIDERABLE 700MB MOISTURE TO WORK ITS WAY ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY REGION. THUS EXPECT SOME MID AND HIGH LEVEL
CLOUDINESS. NONE THE LESS...WITH BUILDING 500MB
HEIGHTS...TEMPERATURES WILL BE ON THE UPSWING.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
305 PM CDT SAT APR 21 2012
MEDIUM RANGE MODELS CONSISTENT IN THEIR SOLUTIONS FROM TUESDAY NIGHT
THROUGH THURSDAY...BUT BEGIN TO DIVERGE FOR FRIDAY AND SATURDAY.
NORTHWEST FLOW WILL CONTINUE THROUGH THE FIRST PART OF THE
PERIOD...WITH BOTH THE GFS AND ECMWF DROPPING A SHORTWAVE THROUGH
THE FLOW TUESDAY NIGHT INTO WEDNESDAY WITH A BAND OF PRECIPITATION
WORKING ITS WAY SOUTHEAST ACROSS THE AREA. HIGHEST PROBABILITIES
STILL LOOK TO BE ON WEDNESDAY. SURFACE HIGH THEN SETTLES IN FOR
THURSDAY AND THURSDAY NIGHT FOR QUIET BUT COOL WEATHER. IN THE
FRIDAY/SATURDAY TIME FRAME...ECMWF PUSHES RIDGE OFF TO THE EAST
FASTER...ALLOWING FOR A SHORTWAVE OVER THE PLAINS TO MOVE
EASTWARD...WHICH WOULD RESULT IN CONVECTION ACROSS THE AREA
HOWEVER...GFS HOLDS HIGH IN PLACE AND KEEPS CONVECTION WEST OF THE
AREA UNTIL LATER SATURDAY. WITH THESE DIFFERENCES...DID KEEP THE
PROBABILITIES FROM THE ALL BLEND SOLUTION FOR FRIDAY AND SATURDAY.
AS FOR TEMPERATURES...READINGS LOOK TO REMAIN SEASONAL THROUGH THE
PERIOD.
&&
.AVIATION...
1000 PM CDT SAT APR 21 2012
LOW CONFIDENCE WITH RELATION TO CIGS AS A COMPLEX SCENARIO MAKES
REFINING THE FORECAST DIFFICULT.
SOME CLARITY THOUGH WITH THE LATEST RUC13 AND 00Z NAM12 KEEPING ANY
DEEPER SATURATION...AND MVFR CIGS...WEST OF KLSE. HOWEVER...BOTH
SUGGEST THAT THE TRACK OF THE SOUTHEAST DEPARTING LOW WILL PLACE
KRST ON THE EASTERN FRINGE OF MVFR CIGS OVERNIGHT. WILL ADD SOME
MENTION FOR KRST.
IN ADDITION TO THE CLOUDS...AN INVERTED SFC TROUGH HANGING NORTH OF
THE LOW WILL BE THE FOCUS FOR SCT -SHRA OVERNIGHT. PROBABLY LIGHT
ENOUGH WHERE VSBYS ARE NOT IMPACTED...WITH MINIMAL ACCUMULATIONS.
THE TROUGH COULD REMAIN A FOCUS FOR SOME -SHRA DEVELOPMENT ON
SUNDAY...BUT ALL MESO MODELS ARE SOUR ON THIS POTENTIAL. DEEP
SATURATION REMAINS AROUND THIS FEATURE...BUT A FETCH OF DRIER MID
LEVEL AIR WILL WORK WEST INTO THE MISSISSIPPI RIVER...HELPING TO
CLEAR AT LEAST SOME OF THE LOW CLOUDS OUT.
LOOK FOR WINDS TO TURN SOUTHEAST THIS EVENING...SWINGING TO THE
NORTH BY 00Z MON. HIGH PRESSURE BUILDS ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY LATE MONDAY...AND SHOULD HELP CLEAR MORE OF THE
MOISTURE/CLOUDS OUT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 PM CDT SAT APR 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM....RABERDING
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
618 PM CDT SAT APR 21 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
MOVING SOUTHEAST OVER THE RED RIVER VALLEY EARLY THIS AFTERNOON...AS
A STRONG SHORTWAVE WITHIN THE LEFT EXIT REGION OF A JET STREAK DIVES
OVER THE NORTHERN MISSISSIPPI VALLEY. ALONG THE 850MB WARM
FRONT...A BAND OF RAIN IS CROSSING THE MINNESOTA/WISCONSIN STATE
BORDER WHILE A MID-LEVEL CLOUD DECK IS MOVING INTO CENTRAL AND
NORTH-CENTRAL WISCONSIN. DRY EAST FLOW OVER THE EASTERN HALF OF THE
STATE HAS BEEN DELAYING THE PROGRESS OF THESE CLOUDS UP UNTIL NOW.
AS THE SURFACE LOW TRACKS SOUTHEAST...SMALL PRECIP CHANCES AND CLOUD
TRENDS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...DECENT SHORTWAVE TROUGH WILL DIVE SE WITHIN THE LEFT EXIT
REGION OF A JET STREAK AND DRIVE A SURFACE LOW OVER THE NORTHERN AND
CENTRAL MISSISSIPPI RIVER VALLEY. THE 850MB THETAE GRADIENT WILL
REMAIN WELL WEST OF THE REGION FOR ANY PRECIP THREAT...BUT WILL SEE
MID AND HIGH CLOUDS ON THE INCREASE FOR THE REST OF THIS AFTERNOON
INTO THIS EVENING. DURING THE OVERNIGHT PERIOD...NE WINDS WILL
ADVECT DRY AIR OUT OF A HUDSON BAY HIGH ACROSS NORTHEAST AND INTO
CENTRAL WISCONSIN...WHERE SHOULD SEE PARTIAL CLEARING AS THE
MID-DECK IS ERODED. IN THE END THOUGH...WILL GO WITH PARTLY TO
MOSTLY CLOUDY SKIES WITH LOWS RANGING FROM THE UPPER 20S NORTH TO
MID 30S SOUTH.
SUNDAY...BEHIND THE DEPARTING SURFACE LOW...A SURFACE TROUGH WILL
HANG BACK ACROSS THE NORTHERN MISSISSIPPI VALLEY. NE WINDS EAST OF
THE SURFACE TROUGH WILL CONTINUE TO FUNNEL IN DRY AIR OVER NORTHEAST
AND CENTRAL WISCONSIN FOR MUCH OF THE MORNING. BUT DURING THE
AFTERNOON...NW WINDS ALOFT WILL START TO PUSH RESIDUAL MOISTURE
ALONG THE TROUGH INTO CENTRAL AND N-C WISCONSIN. SATURATION BECOMES
200-300MB DEEP IN THE AFTERNOON OVER THIS REGION...BUT PROGGED
SOUNDINGS DO NOT SHOW ANY MID-LEVEL INSTABILITY. IN
ADDITION...CANNOT FIND A TRIGGER AND IT ACTUALLY LOOKS LIKE
SHORTWAVE RIDGING TRIES TO BUILD OVER NORTHERN WISCONSIN IN THE
AFTERNOON. AS A RESULT...WILL STICK WITH A DRY FORECAST DESPITE THE
WIDESPREAD SHOWER ACTIVITY UPSTREAM. HIGH TEMPS WILL BE SIMILAR TO
TODAY...MAYBE A DEGREE OR TWO WARMER OVER NE WISCONSIN.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY...TRYING TO SORT OUT
MODEL DIFFERENCES WITH MINOR PCPN CHANCES IS THE MAIN FCST CHALLENGE.
A HIGH AMPLITUDE RIDGE OVER THE ROCKIES AND UPPER LOW OVER THE
EASTERN GREAT LAKES AND NE U.S. WILL DOMINATE THE WEATHER PATTERN FOR
THE BEGINNING OF THE PERIOD. WISCONSIN WILL BE BETWEEN THESE TWO
FEATURES...WITH N-NW FLOW ALOFT. THE PATTERN IS EXPECTED TO
DEAMPLIFY BRIEFLY BY THE MIDDLE OF NEXT WEEK...THEN AMPLIFY AGAIN
LATE IN THE WORK WEEK WITH A STG UPPER RIDGE MOVG INTO THE
NORTHERN PLAINS.
HAVE IGNORED THE SPOTTY QPF SHOWN BY THE MODELS OVER NC WI ON SUNDAY
EVG...AS THERE DOESN`T APPEAR TO BE ANY REAL TRIGGER TO LATCH ONTO.
MODEL TIMESECTIONS DO SHOW QUITE A BIT OF MOISTURE IN THE 850-700 MB
RANGE...SO MOSTLY CLOUDY SKIES LOOK LIKE A GOOD BET. DRY CONDITIONS
WITH PARTLY TO MOSTLY CLOUDY SKIES SHOULD PREVAIL THROUGH MONDAY NIGHT.
ON TUESDAY...HAVE BACKED OFF A BIT ON PCPN CHCS FROM THE PREVIOUS FCST...
BUT DID KEEP A SLIGHT CHC OVER THE SW HALF OF THE CWA. MODELS SHOW
LOW PRESSURE DROPPING SE OUT OF THE NORTHERN PLAINS...WITH A STG
BAROCLINIC ZONE AND SOME INSTABILITY SETTING UP JUST TO OUR SOUTHWEST.
WEAK SFC RIDGING WILL STILL BE IN PLACE OVER NE WI...ALONG WITH VERY
DRY AIR AT 850 MB...SO PULLED POPS THERE ON TUESDAY. CONTINUED
LOW-END POPS ON TUESDAY NIGHT AND WEDNESDAY...AS THE PATTERN DOESN`T
CHANGE MUCH. IF THE RIDGING OVER NE WI ENDS UP BEING A LITTLE
STRONGER...THIS COULD TURN INTO A DRY FCST. EXPECT SEASONABLE
TEMPERATURES DURING THIS PERIOD.
CANADIAN HIGH PRESSURE IS EXPECTED TO DOMINATE ON THU/FRI...WITH DRY
CONDITIONS AND TEMPS A LITTLE BLO NORMAL.
MODEL BLEND GIVES US A CHANCE OF SHOWERS ON FRIDAY NIGHT/SATURDAY...
BUT THE LATEST RUN OF THE ECMWF SEEMS TO BACK OFF ON THIS...AND
CHANGES MAY BE NEEDED WITH SUBSEQUENT FCSTS. CONFIDENCE IS VERY LOW
FOR THIS PORTION OF THE FCST.
&&
.AVIATION...A LOW PRESSURE SYSTEM TRACKING SOUTHEASTWARD OVER
MINNESOTA AND IOWA TONIGHT INTO SUNDAY WILL BE THE FOCUS OF
CONVECTION OVER THE NORTHERN GREAT LAKES AND UPPER MISSISSIPPI
VALLEY REGION. DRY EAST FLOW FROM A HIGH PRESSURE SYSTEM NORTHEAST
OF WISCONSIN WILL CONTINUE TO KEEP PCPN CONFINED OVER FAR WESTERN
WISCONSIN AND AREAS TO THE WEST. A VFR CIG WILL CONTINUE TO DRIFT INTO
CENTRAL WISCONSIN OVERNIGHT AND INTO SUNDAY...WITH VFR CONDITIONS
OVER EASTERN WISCONSIN.
TDH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
605 PM CDT SAT APR 21 2012
.SHORT TERM...TONIGHT THROUGH TUESDAY
305 PM CDT SAT APR 21 2012
MAIN FORECAST CHALLENGE IS ON PRECIPITATION CHANCES TONIGHT INTO
EARLY SUNDAY...AND ITS EASTWARD EXTENT INTO WISCONSIN.
18Z WATER VAPOR IMAGERY SHOWS WELL DEFINED SHORTWAVE OVER EASTERN
NORTH DAKOTA...WHILE A SURFACE LOW RESIDES IN THE SAME AREA...WITH A
COLD FRONT TRAILING TO THE SOUTH INTO EASTERN SOUTH DAKOTA AND
EASTERN NEBRASKA. PLUME OF SHOWERS OUT AHEAD OF THIS WAS OCCURRING
FROM THE ARROWHEAD OF MINNESOTA...SOUTHWARD INTO SOUTH CENTRAL
MINNESOTA AND CENTRAL IOWA. SHOWERS HAVE MADE VERY SLOW PROGRESS
EASTWARD WITH A RATHER DRY EASTERLY SURFACE TO 925 MB FLOW.
21.12Z MODELS OFFER SIMILAR SOLUTIONS THROUGH THE PERIOD. IN THE
NEAR TERM...RUC/NAM/GFS ALL SHOW 900MB-700MB BAND OF FRONTOGENETIC
FORCING TO APPROACH THE MISSISSIPPI RIVER THIS EVENING AND THEN
WEAKEN OVERNIGHT AS IT SLIDES SOUTHEAST. ASSOCIATED PRECIPITATION
WILL CONTINUE TO ENCOUNTER DRY LOW LEVEL EASTERLY FLOW OVER
WISCONSIN WHICH WILL LIMIT THE EASTWARD MOVEMENT OF THE SHOWERS.
HIGHEST PROBABILITIES STILL LOOK TO BE WEST OF THE MISSISSIPPI RIVER
TONIGHT...WITH A RATHER SHARP PRECIPITATION GRADIENT ALONG AND JUST
EAST OF THE RIVER. WITH FORCING WEAKENING OVERNIGHT...DID LOWER
PROBABILITIES AFTER MIDNIGHT.
AS UPPER WAVE/SURFACE LOW MOVES AWAY FROM THE AREA SUNDAY...A
LINGERING SURFACE TROUGH WILL EXTEND NORTHWARD INTO SOUTH CENTRAL
MINNESOTA DURING THE MORNING HOURS. WILL KEEP LOWER END
PROBABILITIES ACROSS THE FAR WEST DURING THE MORNING HOURS...BUT
KEEP THINGS DRY AFTER 18Z. UPPER LEVEL RIDGING THEN BUILDS ACROSS
THE AREA MONDAY AND TUESDAY AS SURFACE HIGH MOVES INTO THE AREA.
EVEN WITH THE HIGH OVERHEAD...BOTH THE NAM AND GFS DO SHOW
CONSIDERABLE 700MB MOISTURE TO WORK ITS WAY ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY REGION. THUS EXPECT SOME MID AND HIGH LEVEL
CLOUDINESS. NONE THE LESS...WITH BUILDING 500MB
HEIGHTS...TEMPERATURES WILL BE ON THE UPSWING.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
305 PM CDT SAT APR 21 2012
MEDIUM RANGE MODELS CONSISTENT IN THEIR SOLUTIONS FROM TUESDAY NIGHT
THROUGH THURSDAY...BUT BEGIN TO DIVERGE FOR FRIDAY AND SATURDAY.
NORTHWEST FLOW WILL CONTINUE THROUGH THE FIRST PART OF THE
PERIOD...WITH BOTH THE GFS AND ECMWF DROPPING A SHORTWAVE THROUGH
THE FLOW TUESDAY NIGHT INTO WEDNESDAY WITH A BAND OF PRECIPITATION
WORKING ITS WAY SOUTHEAST ACROSS THE AREA. HIGHEST PROBABILITIES
STILL LOOK TO BE ON WEDNESDAY. SURFACE HIGH THEN SETTLES IN FOR
THURSDAY AND THURSDAY NIGHT FOR QUIET BUT COOL WEATHER. IN THE
FRIDAY/SATURDAY TIME FRAME...ECMWF PUSHES RIDGE OFF TO THE EAST
FASTER...ALLOWING FOR A SHORTWAVE OVER THE PLAINS TO MOVE
EASTWARD...WHICH WOULD RESULT IN CONVECTION ACROSS THE AREA
HOWEVER...GFS HOLDS HIGH IN PLACE AND KEEPS CONVECTION WEST OF THE
AREA UNTIL LATER SATURDAY. WITH THESE DIFFERENCES...DID KEEP THE
PROBABILITIES FROM THE ALL BLEND SOLUTION FOR FRIDAY AND SATURDAY.
AS FOR TEMPERATURES...READINGS LOOK TO REMAIN SEASONAL THROUGH THE
PERIOD.
&&
.AVIATION...
605 PM CDT SAT APR 21 2012
FORECAST CONFIDENCE IS LOW TONIGHT WITH RELATION TO CIGS AS A
COMPLEX SCENARIO MAKES REFINING THE FORECAST DIFFICULT.
BAND OF -SHRA MOVING INTO WESTERN WI CURRENTLY...BUT RUNNING INTO
DRIER AIR. MOSTLY VFR TO SOME MVFR CIGS WITH THIS PCPN. A BROKEN
LINE OF SHRA/TS WAS MOVING OUT AHEAD OF A COLD FRONT RUNNING NORTH
SOUTH ACROSS WESTERN MN/IA. INSTABILITY WILL WANE AS THE STORMS
APPROACH KRST...AND THE THREAT SHOULD BE LOW FOR THUNDER. WILL HAVE
TO KEEP A CLOSE EYE ON THIS THOUGH. MOSTLY VFR CIGS ASSOCIATED WITH
THIS ACTIVITY.
FARTHER NORTH...AROUND AND NORTH OF A SFC LOW OVER WESTERN MN...A
LOT OF 1-2 KFT CIGS. LATEST NAM12 SUGGESTS THAT THESE WILL STAY WEST
OF KRST/KLSE...WHILE THE RUC13 HINTS THAT THERE COULD BE SOME
REDEVELOPMENT OVER THE AREA OVERNIGHT. HAVE OPTED TO LEAN ON VFR
CONDITIONS...BUT AGAIN...CONFIDENCE IS NOT HIGH.
THE SFC LOW WILL SINK SOUTHEAST TONIGHT....LEAVING A NORTHWARD
RUNNING INVERTED TROUGH HANGING ACROSS MN SUNDAY...ALONG WITH DEEP
SATURATION. HOWEVER...A FETCH OF DRIER MID LEVEL AIR WILL WORK WEST
INTO THE MISSISSIPPI RIVER...HELPING TO CLEAR AT LEAST SOME OF THE
LOW CLOUDS OUT. COULD SEE A FEW MORE -SHRA DEVELOP AROUND THE
TROUGH.
LOOK FOR WINDS TO TURN SOUTHEAST THIS EVENING...SWINGING TO THE
NORTH BY 00Z MON. HIGH PRESSURE BUILDS ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY LATE MONDAY...AND SHOULD HELP CLEAR MORE OF THE
MOISTURE/CLOUDS OUT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
305 PM CDT SAT APR 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM....RABERDING
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
323 PM CDT FRI APR 20 2012
.SHORT TERM...TONIGHT THROUGH MONDAY
323 PM CDT FRI APR 20 2012
MAIN FORECAST CONCERNS ARE ON FROST/FREEZE POTENTIAL TONIGHT AND
RAIN SHOWER CHANCES SATURDAY THROUGH SUNDAY.
LATEST SURFACE OBSERVATIONS SHOWED AN AREA OF HIGH PRESSURE
EXTENDING FROM THE ARROWHEAD OF MINNESOTA...SOUTH ACROSS EASTERN
MINNESOTA INTO CENTRAL IOWA. LOOK FOR THE HIGH TO SHIFT EAST OVER
THE FORECAST AREA TONIGHT.
COOL HIGH PRESSURE WILL SLIDE OVER THE UPPER MISSISSIPPI RIVER
VALLEY TONIGHT WITH LIGHT AND VARIABLE WINDS EXPECTED. LOOK FOR
TEMPERATURES TO FALL INTO THE MID 20S ACROSS NORTH CENTRAL INTO
CENTRAL WISCONSIN. SLIGHTLY WARMER TEMPERATURES ARE ANTICIPATED FOR
LOCATIONS NEAR AND ALONG THE MISSISSIPPI RIVER WITH LOWS FALLING TO
AROUND FREEZING OR SLIGHTLY BELOW. LOCATIONS FURTHER WEST...ACROSS
SOUTHEAST MINNESOTA INTO NORTHEAST IOWA...LOOK FOR LOWS TO FALL INTO
THE LOWER 30S. WILL CONTINUE FREEZE WARNING ACROSS PORTIONS OF
SOUTHWEST...CENTRAL...AND NORTH CENTRAL WISCONSIN. HAVE DECIDED TO
HOIST A FROST ADVISORY FOR COUNTIES ALONG THE MISSISSIPPI RIVER
WHERE TEMPERATURES WILL FALL INTO THE LOWER 30S AND AREAS OF FROST
ARE EXPECTED. THE FROST ADVISORY WILL RUN FROM 1 AM THOUGH 8 AM
SATURDAY. IN ADDITION...SOME PATCHY FOG IS POSSIBLE ACROSS THE
AREA TONIGHT...BUT LOOKING AT SURFACE OBSERVATIONS UPSTREAM ACROSS
CENTRAL MINNESOTA INTO NORTHERN MINNESOTA...DEWPOINTS ARE FALLING
INTO THE MID 20S TO LOWER TEENS. IN ADDITION...WINDS ALOFT LOOK TO
INCREASE TONIGHT FROM JUST ABOVE THE SURFACE THROUGH 1 KFT. WILL
HAVE TO KEEP A CLOSE WATCH ON THE POTENTIAL FOR VALLEY FOG ALONG
THE MISSISSIPPI RIVER AND WISCONSIN RIVER VALLEYS. GIVEN THE DRY
NATURE OF THE AIR MASS AND WINDS INCREASING ALOFT...FEEL OVERALL
FOG COVERAGE WILL BE LIMITED. ANOTHER CONCERN IS HIGH CLOUDS
MOVING INTO THE AREA AROUND 06Z TONIGHT. WILL HAVE TO KEEP A CLOSE
WATCH ON THIS CLOUD SHIELD WITH THE POTENTIAL FOR TEMPERATURES TO
STAY JUST ABOVE FREEZING ALONG AND WEST OF THE MISSISSIPPI RIVER.
A SHORTWAVE TROUGH WILL PUSH INTO MINNESOTA EARLY ON SATURDAY WITH
SHOWERS SPREADING FROM WEST TO EAST ACROSS MINNESOTA INTO NORTHEAST
IOWA. THE BULK OF THE SHOWER ACTIVITY IS EXPECTED TO STAY WEST OF
THE MISSISSIPPI RIVER UNTIL LATE SATURDAY AFTERNOON THEN SPREAD INTO
WESTERN WISCONSIN DURING THE EARLY EVENING. FORECAST MODELS HAVE
BEEN VERY CONSISTENT WITH THIS FEATURE...BUT SOME SMALL TIMING
DIFFERENCES REMAIN. A MAJORITY OF THE GUIDANCE SIDES WITH KEEPING
THE RAIN MAINLY WEST OF THE MISSISSIPPI RIVER THROUGH LATE AFTERNOON
SO DECIDED TO LEAN THAT DIRECTION AND INCREASE PRECIPITATION
CHANCES. MOST LOCATIONS SHOULD SEE AT LEAST A FEW HUNDREDTHS OF AN
INCH OF RAINFALL OUT OF THIS SYSTEM..WITH SOME AREAS RECEIVING A
FEW TENTHS. LOOK FOR SHOWERS TO PERSIST INTO SUNDAY EVENING BEFORE
TAPERING OFF LATE IN THE NIGHT. PLAN ON HIGH TEMPERATURES IN THE
LOWER TO MIDDLE 50S. LOOK FOR OVERNIGHT LOWS TO FALL INTO THE LOWER
30S ACROSS NORTH CENTRAL WISCONSIN...AND INTO THE UPPER 30S TO LOWER
40S ACROSS NORTHEAST IOWA.
ANOTHER SHORTWAVE IS EXPECTED TO PUSH ACROSS THE REGION ON SUNDAY
AND DRAGS A FRONTAL BOUNDARY ACROSS THE FORECAST AREA. LOOK FOR
SCATTERED SHOWERS ACROSS THE AREA AS THE WAVE MOVES IN. IN
ADDITION...PLAN ON WINDS SWITCHING TO THE NORTHWEST...BECOMING GUSTY
AT TIMES ESPECIALLY UNDER ANY RAIN SHOWERS. THE STRONGEST WINDS ARE
EXPECTED ALONG AND WEST OF THE MISSISSIPPI RIVER WHERE THE PRESSURE
GRADIENT WILL BE THE TIGHTEST. PLAN ON NORTHWEST WINDS OF 10 TO 20
MPH...GUSTING TO AROUND 35 MPH UNDER THE RAIN SHOWERS. PLAN ON HIGHS
ON SUNDAY RANGING FROM THE LOWER 50S ACROSS NORTH CENTRAL WISCONSIN
TO MID TO UPPER 50S ACROSS NORTHEAST IOWA. SURFACE HIGH PRESSURE IS
EXPECTED TO SETTLE OVER THE AREA SUNDAY NIGHT INTO MONDAY PROVIDING
COOL AND QUIET CONDITIONS. LOW PRESSURE OVER THE EASTERN GREAT LAKES
WILL LIFT NORTHWARD AND RETROGRADE TOWARD HUDSON BAY. PLAN ON HIGHS
ONCE AGAIN MAINLY IN THE 50S ON MONDAY.
.LONG TERM...TUESDAY THROUGH FRIDAY
323 PM CDT FRI APR 20 2012
20.12 FORECAST MODELS IN BETTER AGREEMENT THIS RUN SHOWING A FAST
MOVING SHORTWAVE CLIPPING THE REGION TUESDAY NIGHT INTO WEDNESDAY.
THIS WAVE ALONG WITH A BAROCLINIC ZONE EDGING IN FROM THE
WEST...WILL BRING CHANCES FOR SHOWERS AND THUNDERSTORMS TO THE AREA.
A DEEP UPPER LEVEL TROUGH IS EXPECTED TO DIVE INTO THE UPPER
MISSISSIPPI RIVER VALLEY THURSDAY INTO THURSDAY NIGHT BRINGING A
CHANCE OF SHOWERS TO THE AREA. THE ECMWF OFFERS A COLDER SOLUTION
OVER THE GFS THURSDAY NIGHT THROUGH FRIDAY...KEEPING A HIGH
AMPLITUDE RIDGE OVER THE CENTRAL CONUS EXTENDING NORTHWEST THROUGH
CENTRAL MANITOBA/SASKATCHEWAN. THE GFS ATTEMPTS TO SLIDE THIS RIDGE
EAST INTO THE REGION...WHICH WOULD FAVOR WARMER TEMPERATURES. GIVEN
THE MODEL DIFFERENCES DECIDED TO LEAN TOWARD A MODEL CONSENSUS
BLEND. LOOK FOR HIGH TEMPERATURES ON THURSDAY IN THE LOWER
60S...WITH LOWS FALLING INTO THE UPPER 30S TO LOWER 40S THURSDAY
NIGHT. THESE LOW COULD BE 5 DEGREES COOLER IF THE ECMWF SOLUTIONS
HOLDS. HAVE INCLUDED A CHANCE OF SHOWERS ACROSS SOUTHWEST THROUGH
CENTRAL AND NORTH CENTRAL WISCONSIN...WITH THE MAIN FORCING FROM
THE UPPER LEVEL TROUGH MOVING THROUGH THESE AREAS.
&&
.AVIATION...THROUGH 18Z SATURDAY
1232 PM CDT FRI APR 20 2012
BIGGEST CONCERN IS ON FOG POTENTIAL TONIGHT AND ITS IMPACT AT THE
TAF SITES. CLOUDS DECREASED AT TAF SITES LATE THIS MORNING...BUT
WITH COLD AIR ALOFT...CUMULUS WAS REFORMING WITH A SCT-BKN DECK.
BASES EXPECTED TO REMAIN IN THE 3K-4K FOOT RANGE THROUGHOUT THE
DAY...BEFORE DIMINISHING THIS EVENING DUE TO LOSS OF HEATING.
TRANSIENT SURFACE RIDGE BUILDS ACROSS THE AREA TONIGHT WITH WINDS
BECOMING LIGHT AND SKIES MAINLY CLEAR...AT LEAST THROUGH 06Z.
POTENTIAL EXISTS FOR SOME FOG FORMATION WITH THE RECENT
RAINS...BUT THERE ARE SOME NEGATIVE FACTORS THAT LOWERS
CONFIDENCE. THOSE NEGATIVE FACTORS ARE AN INCREASE IN HIGH LEVEL
CLOUDS AFTER 06Z...ALONG WITH THE SURFACE RIDGE PUSHING EAST WITH
WINDS BECOMING MORE SOUTHERLY. 20.12Z NAM BUFKIT SOUNDS SHOWING
WINDS STRENGTHENING ABOVE THE BOUNDARY LAYER LATE TONIGHT...WITH
THE 20.15Z RUC NOT QUITE AS AGGRESSIVE WITH THESE WINDS. FEEL
BIGGEST THEREAT FOR FOG WOULD BE AT KLSE...WHERE CLOUDS/WINDS
DELAYED IN GETTING IN THERE. THUS DID INTRODUCE BCFG IN THE TAF.
THIS WILL HAVE TO BE MONITORED CLOSELY DURING THE EVENING.
NEXT SHORTWAVE DROPS THROUGH THE FLOW SATURDAY MORNING...WITH THE
GFS/GEM SHOWING PRECIPITATION ENTERING SOUTHEAST MINNESOTA BETWEEN
15Z-18Z...WHILE NAM HOLDS IT OFF UNTIL AFTER 18Z. DID INTRODUCE
VCSH AT KRST...WITH KLSE REMAINING DRY. CEILINGS EXPECTED TO
REMAIN VFR AT BOTH SITES...ALTHOUGH LOWERING TO AROUND 8K FEET AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
313 PM CDT FRI APR 20 2012
WI...FROST ADVISORY FROM 1 AM TO 8 AM CDT SATURDAY FOR WIZ032-033-041-
054-061.
FREEZE WARNING FROM 1 AM TO 8 AM CDT SATURDAY FOR WIZ017-029-034-
042>044-053-055.
MN...FROST ADVISORY FROM 1 AM TO 8 AM CDT SATURDAY FOR MNZ079-088-096.
IA...FROST ADVISORY FROM 1 AM TO 8 AM CDT SATURDAY FOR IAZ011-030.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1232 PM CDT FRI APR 20 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
333 AM CDT FRI APR 20 2012
MAIN FORECAST CONCERNS ARE ON FROST/FREEZE TONIGHT AND NEXT EXPECTED
RAIN SATURDAY/SATURDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP OVER THE WESTERN U.S....TROUGHING FROM
MINNESOTA SOUTH INTO TEXAS...AND RIDGING ALONG THE EAST COAST OF THE
U.S. WITHIN THE TROUGHING...MAIN FEATURES OF NOTE INCLUDE SHORTWAVES
OVER THE EASTERN SIDE OF THE FORECAST AREA AND BACK OVER WESTERN
SOUTH DAKOTA INTO NORTHWEST NEBRASKA. THE LATTER SHORTWAVE HAS
HELPED PUSH THE LOW TO MID LEVEL FRONTOGENESIS ZONE AND DEEP
MOISTURE SEEN ON THE 00Z GRB SOUNDING EASTWARD. REGARDING THAT
FRONTOGENESIS ZONE...THIS IS EASILY SEEN IN 00Z RAOBS AT 850MB WITH
0C AT MPX...3C AT GRB AND 12C AT DVN. IN ADDITION...AN UPPER JET
STREAK OF 100-110 KT IN EASTERN ONTARIO LAST EVENING...AIDING IN
FORCING FOR PRECIPITATION ACROSS WISCONSIN...HAS BEEN PUSHED
EASTWARD BY THE SHORTWAVE. LATEST RADAR MOSAIC SHOWS JUST A LITTLE
LIGHT RAIN/SNOW IN A WEAKENING COLD CONVEYOR BELT IN CENTRAL
WISCONSIN. TO THE WEST...SUBSIDENCE AND DRYING HAS BEEN CLEARING
SKIES OUT ACROSS MINNESOTA. A SURFACE RIDGE OF HIGH PRESSURE HAS
ALSO BEEN DROPPING SOUTH INTO THE DAKOTAS AND WESTERN MINNESOTA.
FARTHER WEST...A FEW SHOWERS CONTINUE BACK OVER CENTRAL SOUTH
DAKOTA AHEAD OF THE SHORTWAVE THERE. LAST ITEM OF NOTE IS A
SHORTWAVE ON WATER VAPOR COMING INTO SOUTHERN BRITISH COLUMBIA.
TODAY AND TONIGHT...UPPER TROUGHING OVER MINNESOTA WILL SLIDE EAST
ACROSS THE THE FORECAST AREA TODAY...ALLOWING THE SURFACE RIDGE OF
HIGH PRESSURE TO BUILD INTO THE FORECAST AREA THIS EVENING. THIS
SHOULD ALLOW FOR CLEARING AND DRYING. TEMPERATURES ARE LIKELY TO NOT
END UP MUCH HIGHER THAN YESTERDAY BECAUSE 850MB TEMPS ARE -2 TO
-3C...BUT MORE SUN AND THE LACK OF RAIN WILL MAKE IT FEEL WARMER.
QUESTION TONIGHT IS FROST/FREEZE. HAVING THE SURFACE RIDGE OVER
THE AREA IN THE EVENING IS GOOD FOR GETTING COLD...BUT THERE IS AN
ISSUE LURKING UPSTREAM. THE SHORTWAVE COMING INTO SOUTHERN BRITISH
COLUMBIA MODELS SHOW TOPPING THE WESTERN U.S. RIDGE TODAY...THEN
DROPPING INTO THE EASTERN DAKOTAS BY 12Z SATURDAY. ANTICIPATING A
STREAM OF MID AND HIGH LEVEL CLOUD COVER TO SPREAD DOWNSTREAM
AHEAD OF THIS SHORTWAVE...MOVING INTO THE FORECAST AREA AFTER
MIDNIGHT. IT APPEARS LOCATIONS ACROSS SOUTHWEST INTO CENTRAL
WISCONSIN WILL STAY THE CLEAREST THE LONGEST...AND THE SURFACE
RIDGE IS EXPECTED TO STAY IN PLACE THERE TOO. THEREFORE... FEEL
THIS AREA HAS THE BEST POTENTIAL FOR FREEZE CONDITIONS WITH
AREAS/WIDESPREAD FROST. FREEZE WARNINGS NOTED IN THE WWA SECTION
BELOW. ANOTHER POTENTIAL ISSUE TO CONTEND WITH MIGHT BE FOG GIVEN
RECENT RAINS. NOT VERY CONFIDENT TO INCLUDE FOG AT THIS TIME...
EITHER FOR RADIATIONAL INDUCED OR IN THE VALLEYS...AS THERE SHOULD
BE DECENT DRYING TODAY.
SATURDAY AND SATURDAY NIGHT...SHORTWAVE OVER THE EASTERN DAKOTAS
LOOKS TO CONTINUE ITS SOUTHEASTWARD TREK DOWN THE UPPER RIDGE. THE
20.00Z NAM IS AN OUTLIER WITH ITS TRACK...MOVING INTO WISCONSIN
TONIGHT. THE 20.00Z GFS/UKMET/ECMWF ALL TAKE A FARTHER WEST TRACK
THROUGH SOUTHEAST MINNESOTA AND NORTHEAST IOWA TONIGHT WHICH SEEMS
MORE REASONABLE. ISENTROPIC LIFT ASSOCIATED WITH THE SHORTWAVE...
BEST SEEN ON 290-300K SURFACES...WILL MOVE INTO SOUTHEAST MINNESOTA
AND NORTHEAST IOWA ON SATURDAY. SHOULD EVENTUALLY SEE RAIN DEVELOP
AS LOW LEVELS MOISTEN. AFTERNOON SEEMS MOST LIKELY TO SEE RAIN.
ANOTHER FAVORABLE FORCING MECHANISM IS A 120KT UPPER JET DROPPING
DOWN INTO SOUTHWEST MINNESOTA...PLACING LOCATIONS WEST OF THE
MISSISSIPPI RIVER IN UPPER DIVERGENCE. NICE LOW TO MID LEVEL
FRONTOGENESIS/FRONTOLYSIS COUPLET SHOWS UP TOO. BOTH THE ISENTROPIC
LIFT AND UPPER JET FORCING DIMINISHES SATURDAY NIGHT...WHICH WOULD
SUGGEST PRECIPITATION SHOULD DIMINISH. THE LOW TO MID LEVEL
FRONTOGENESIS LINGERS...THOUGH...NOTED TOO BY AN INVERTED TROUGH AT
THE SURFACE LINGERING BACK INTO WESTERN MINNESOTA. THEREFORE...
SHOULD STILL SEE SOME LIGHT PRECIPITATION AFTER MIDNIGHT. GIVEN THE
STRONG FORCING SIGNALS...HAVE RAISED PRECIPITATION CHANCES
UP...ESPECIALLY WEST OF THE MISSISSIPPI RIVER. PRECIPITABLE WATER
VALUES ARE NOT THAT IMPRESSIVE...0.5-0.6 INCHES...WHICH MEANS WE
SHOULD NOT SEE MUCH QPF. ONLY CONCERN THAT EXISTS IS THE
PRECIPITATION COULD SHIFT WESTWARD OVER THE NEXT 24-48 HOURS SEEING
MODEL TRENDS. WITH PLENTY OF CLOUDS SPREADING IN SATURDAY MORNING
AND 850MB TEMPS OF 0 TO -2C ON SATURDAY...ANTICIPATING COOL
TEMPERATURES. ONLY 5 TO 10 DEGREES OF COOLING EXPECTED SATURDAY
NIGHT THANKS TO CLOUDS REMAINING IN PLACE.
SUNDAY AND SUNDAY NIGHT...20.00Z GFS/NAM/UKMET/ECMWF/CANADIAN ALL
SHOW ANOTHER SHORTWAVE DROPPING DOWN THE EAST SIDE OF THE WESTERN
U.S. RIDGE. AGAIN...THE MODELS DIFFER WITH THE TRACK...UKMET
FARTHEST WEST NEAR I-35 WITH THE NAM FARTHEST EAST OVER SOUTHWEST
WISCONSIN. IN ANY EVENT...THIS SHORTWAVE COMES THROUGH DURING THE
DAYTIME HOURS. WITH THAT INVERTED SURFACE TROUGH IN PLACE AND
DAYTIME HEATING...SHOULD SEE SOME ISOLATED/SCATTERED SHOWERS
DEVELOP. IF THERE IS ANYTHING GOING AGAINST PRECIPITATION IS A
NORTHEAST TO SOUTHWEST ORIENTED SURFACE RIDGE PROGGED TO BUILD INTO
THE AREA DURING THE AFTERNOON. A DRYING NORTHEAST FLOW COULD LIMIT
SOME OF THE AREAL COVERAGE OF PRECIPITATION...AS SUGGESTED IN 20.00Z
GFS OUTPUT. THEREFORE...FOR NOW CHANCES ARE ONLY 20-30. THE DRYING
FLOW PLUS DAYTIME MIXING SHOULD ALLOW FOR SOME DECREASE IN
CLOUDS...THOUGH A BETTER SHOT OF CLEARING SHOULD COME SUNDAY NIGHT
WITH SUBSIDENCE IN THE WAKE OF THE SHORTWAVE. REGARDING
TEMPERATURES...850MB READINGS ON SUNDAY ARE SIMILAR TO SATURDAY...0
TO -2C. WITH OVERALL LIMITED SUN...ANTICIPATE ANOTHER RELATIVELY
COOL DAY WITH HIGHS IN THE 50S. IF MORE SUN OCCURS THAN
EXPECTED...READINGS MAY GET INTO THE 60S. WITH CLEARING SUNDAY NIGHT
AND THE RIDGE SETTLING IN...COULD SEE YET ANOTHER FROST/FREEZE
NIGHT...ESPECIALLY FOR SOUTHWEST AND CENTRAL WISCONSIN.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
333 AM CDT FRI APR 20 2012
DIFFICULT LONG TERM FORECAST...ESPECIALLY GETTING INTO THE MIDDLE OF
NEXT WEEK WHERE MODELS ARE ALL OVER THE PLACE WITH THE HANDLING OF
THE UPPER LEVEL PATTERN OVER THE UPPER MISSISSIPPI RIVER VALLEY
REGION. THROUGH ABOUT TUESDAY...MODELS ARE IN GOOD AGREEMENT
MAINTAINING WESTERN RIDGING AND TROUGHING OVER THE EAST COAST OF THE
U.S.. 500MB HEIGHTS DO RISE MONDAY THROUGH TUESDAY WHICH WILL HELP
TO BRING WARMER AIR INTO THE FORECAST AREA. BY 00Z WEDNESDAY...850MB
TEMPS CLIMB TO 4-8C...IF NOT A LITTLE HIGHER. STILL HAVING TO
MAINTAIN SOME CHANCES OF PRECIPITATION TUESDAY NIGHT...DUE TO A
SHORTWAVE PROGGED TO COME THROUGH THE NORTHWEST FLOW. 20.00Z
ECMWF/GEM ARE PRETTY ACTIVE WITH THIS SHORTWAVE TOO...RESULTING FROM
FAVORABLE DYNAMICAL FORCING. WHAT HAPPENS IN THE WAKE OF THIS
FEATURE IS ANYONES GUESS RIGHT NOW. THE 20.00Z ECMWF IS STUCK WITH
TROUGHING FROM HUDSON BAY DOWN INTO THE EASTERN GREAT LAKES...
MAINTAIN A COOL NORTHWEST FLOW. WOULD PROBABLY END UP WITH
PERIODIC RAIN SHOWERS WITH SHORTWAVES MOVING THROUGH IN THE ECMWF
SCENARIO. ON THE OTHER HAND...THE 20.00Z GFS/GFS ENSEMBLES SAY
WEDNESDAY THROUGH THURSDAY THE WESTERN RIDGE TRIES TO BUILD
TOWARDS THE AREA...BEING PUSHED MORE BY TROUGHING COMING INTO THE
WEST COAST. IF THIS HAPPENS...PERIODIC SHOWER AND THUNDERSTORMS
CHANCES WOULD RESULT AS A WARM FRONT APPROACHES THE REGION. THE
SOLUTIONS ALSO ARE MUCH WARMER THAN THE ECMWF. FOR NOW...HAVE
SPLIT THE DIFFERENCE BETWEEN THE TWO SOLUTIONS. NEEDLESS TO
SAY...CONFIDENCE ON THE PRECIPITATION AND TEMPERATURE FORECASTS IS
LOW.
&&
.AVIATION...THROUGH 18Z SATURDAY
1232 PM CDT FRI APR 20 2012
BIGGEST CONCERN IS ON FOG POTENTIAL TONIGHT AND ITS IMPACT AT THE
TAF SITES. CLOUDS DECREASED AT TAF SITES LATE THIS MORNING...BUT
WITH COLD AIR ALOFT...CUMULUS WAS REFORMING WITH A SCT-BKN DECK.
BASES EXPECTED TO REMAIN IN THE 3K-4K FOOT RANGE THROUGHOUT THE
DAY...BEFORE DIMINISHING THIS EVENING DUE TO LOSS OF HEATING.
TRANSIENT SURFACE RIDGE BUILDS ACROSS THE AREA TONIGHT WITH WINDS
BECOMING LIGHT AND SKIES MAINLY CLEAR...AT LEAST THROUGH 06Z.
POTENTIAL EXISTS FOR SOME FOG FORMATION WITH THE RECENT
RAINS...BUT THERE ARE SOME NEGATIVE FACTORS THAT LOWERS
CONFIDENCE. THOSE NEGATIVE FACTORS ARE AN INCREASE IN HIGH LEVEL
CLOUDS AFTER 06Z...ALONG WITH THE SURFACE RIDGE PUSHING EAST WITH
WINDS BECOMING MORE SOUTHERLY. 20.12Z NAM BUFKIT SOUNDS SHOWING
WINDS STRENGTHENING ABOVE THE BOUNDARY LAYER LATE TONIGHT...WITH
THE 20.15Z RUC NOT QUITE AS AGGRESSIVE WITH THESE WINDS. FEEL
BIGGEST THEREAT FOR FOG WOULD BE AT KLSE...WHERE CLOUDS/WINDS
DELAYED IN GETTING IN THERE. THUS DID INTRODUCE BCFG IN THE TAF.
THIS WILL HAVE TO BE MONITORED CLOSELY DURING THE EVENING.
NEXT SHORTWAVE DROPS THROUGH THE FLOW SATURDAY MORNING...WITH THE
GFS/GEM SHOWING PRECIPITATION ENTERING SOUTHEAST MINNESOTA BETWEEN
15Z-18Z...WHILE NAM HOLDS IT OFF UNTIL AFTER 18Z. DID INTRODUCE
VCSH AT KRST...WITH KLSE REMAINING DRY. CEILINGS EXPECTED TO
REMAIN VFR AT BOTH SITES...ALTHOUGH LOWERING TO AROUND 8K FEET AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
333 AM CDT FRI APR 20 2012
WI...FREEZE WARNING FROM 1 AM TO 8 AM CDT SATURDAY FOR
WIZ017-029-034-042>044-053-055.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
626 AM CDT FRI APR 20 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
333 AM CDT FRI APR 20 2012
MAIN FORECAST CONCERNS ARE ON FROST/FREEZE TONIGHT AND NEXT EXPECTED
RAIN SATURDAY/SATURDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP OVER THE WESTERN U.S....TROUGHING FROM
MINNESOTA SOUTH INTO TEXAS...AND RIDGING ALONG THE EAST COAST OF THE
U.S. WITHIN THE TROUGHING...MAIN FEATURES OF NOTE INCLUDE SHORTWAVES
OVER THE EASTERN SIDE OF THE FORECAST AREA AND BACK OVER WESTERN
SOUTH DAKOTA INTO NORTHWEST NEBRASKA. THE LATTER SHORTWAVE HAS
HELPED PUSH THE LOW TO MID LEVEL FRONTOGENESIS ZONE AND DEEP
MOISTURE SEEN ON THE 00Z GRB SOUNDING EASTWARD. REGARDING THAT
FRONTOGENESIS ZONE...THIS IS EASILY SEEN IN 00Z RAOBS AT 850MB WITH
0C AT MPX...3C AT GRB AND 12C AT DVN. IN ADDITION...AN UPPER JET
STREAK OF 100-110 KT IN EASTERN ONTARIO LAST EVENING...AIDING IN
FORCING FOR PRECIPITATION ACROSS WISCONSIN...HAS BEEN PUSHED
EASTWARD BY THE SHORTWAVE. LATEST RADAR MOSAIC SHOWS JUST A LITTLE
LIGHT RAIN/SNOW IN A WEAKENING COLD CONVEYOR BELT IN CENTRAL
WISCONSIN. TO THE WEST...SUBSIDENCE AND DRYING HAS BEEN CLEARING
SKIES OUT ACROSS MINNESOTA. A SURFACE RIDGE OF HIGH PRESSURE HAS
ALSO BEEN DROPPING SOUTH INTO THE DAKOTAS AND WESTERN MINNESOTA.
FARTHER WEST...A FEW SHOWERS CONTINUE BACK OVER CENTRAL SOUTH
DAKOTA AHEAD OF THE SHORTWAVE THERE. LAST ITEM OF NOTE IS A
SHORTWAVE ON WATER VAPOR COMING INTO SOUTHERN BRITISH COLUMBIA.
TODAY AND TONIGHT...UPPER TROUGHING OVER MINNESOTA WILL SLIDE EAST
ACROSS THE THE FORECAST AREA TODAY...ALLOWING THE SURFACE RIDGE OF
HIGH PRESSURE TO BUILD INTO THE FORECAST AREA THIS EVENING. THIS
SHOULD ALLOW FOR CLEARING AND DRYING. TEMPERATURES ARE LIKELY TO NOT
END UP MUCH HIGHER THAN YESTERDAY BECAUSE 850MB TEMPS ARE -2 TO
-3C...BUT MORE SUN AND THE LACK OF RAIN WILL MAKE IT FEEL WARMER.
QUESTION TONIGHT IS FROST/FREEZE. HAVING THE SURFACE RIDGE OVER
THE AREA IN THE EVENING IS GOOD FOR GETTING COLD...BUT THERE IS AN
ISSUE LURKING UPSTREAM. THE SHORTWAVE COMING INTO SOUTHERN BRITISH
COLUMBIA MODELS SHOW TOPPING THE WESTERN U.S. RIDGE TODAY...THEN
DROPPING INTO THE EASTERN DAKOTAS BY 12Z SATURDAY. ANTICIPATING A
STREAM OF MID AND HIGH LEVEL CLOUD COVER TO SPREAD DOWNSTREAM
AHEAD OF THIS SHORTWAVE...MOVING INTO THE FORECAST AREA AFTER
MIDNIGHT. IT APPEARS LOCATIONS ACROSS SOUTHWEST INTO CENTRAL
WISCONSIN WILL STAY THE CLEAREST THE LONGEST...AND THE SURFACE
RIDGE IS EXPECTED TO STAY IN PLACE THERE TOO. THEREFORE... FEEL
THIS AREA HAS THE BEST POTENTIAL FOR FREEZE CONDITIONS WITH
AREAS/WIDESPREAD FROST. FREEZE WARNINGS NOTED IN THE WWA SECTION
BELOW. ANOTHER POTENTIAL ISSUE TO CONTEND WITH MIGHT BE FOG GIVEN
RECENT RAINS. NOT VERY CONFIDENT TO INCLUDE FOG AT THIS TIME...
EITHER FOR RADIATIONAL INDUCED OR IN THE VALLEYS...AS THERE SHOULD
BE DECENT DRYING TODAY.
SATURDAY AND SATURDAY NIGHT...SHORTWAVE OVER THE EASTERN DAKOTAS
LOOKS TO CONTINUE ITS SOUTHEASTWARD TREK DOWN THE UPPER RIDGE. THE
20.00Z NAM IS AN OUTLIER WITH ITS TRACK...MOVING INTO WISCONSIN
TONIGHT. THE 20.00Z GFS/UKMET/ECMWF ALL TAKE A FARTHER WEST TRACK
THROUGH SOUTHEAST MINNESOTA AND NORTHEAST IOWA TONIGHT WHICH SEEMS
MORE REASONABLE. ISENTROPIC LIFT ASSOCIATED WITH THE SHORTWAVE...
BEST SEEN ON 290-300K SURFACES...WILL MOVE INTO SOUTHEAST MINNESOTA
AND NORTHEAST IOWA ON SATURDAY. SHOULD EVENTUALLY SEE RAIN DEVELOP
AS LOW LEVELS MOISTEN. AFTERNOON SEEMS MOST LIKELY TO SEE RAIN.
ANOTHER FAVORABLE FORCING MECHANISM IS A 120KT UPPER JET DROPPING
DOWN INTO SOUTHWEST MINNESOTA...PLACING LOCATIONS WEST OF THE
MISSISSIPPI RIVER IN UPPER DIVERGENCE. NICE LOW TO MID LEVEL
FRONTOGENESIS/FRONTOLYSIS COUPLET SHOWS UP TOO. BOTH THE ISENTROPIC
LIFT AND UPPER JET FORCING DIMINISHES SATURDAY NIGHT...WHICH WOULD
SUGGEST PRECIPITATION SHOULD DIMINISH. THE LOW TO MID LEVEL
FRONTOGENESIS LINGERS...THOUGH...NOTED TOO BY AN INVERTED TROUGH AT
THE SURFACE LINGERING BACK INTO WESTERN MINNESOTA. THEREFORE...
SHOULD STILL SEE SOME LIGHT PRECIPITATION AFTER MIDNIGHT. GIVEN THE
STRONG FORCING SIGNALS...HAVE RAISED PRECIPITATION CHANCES
UP...ESPECIALLY WEST OF THE MISSISSIPPI RIVER. PRECIPITABLE WATER
VALUES ARE NOT THAT IMPRESSIVE...0.5-0.6 INCHES...WHICH MEANS WE
SHOULD NOT SEE MUCH QPF. ONLY CONCERN THAT EXISTS IS THE
PRECIPITATION COULD SHIFT WESTWARD OVER THE NEXT 24-48 HOURS SEEING
MODEL TRENDS. WITH PLENTY OF CLOUDS SPREADING IN SATURDAY MORNING
AND 850MB TEMPS OF 0 TO -2C ON SATURDAY...ANTICIPATING COOL
TEMPERATURES. ONLY 5 TO 10 DEGREES OF COOLING EXPECTED SATURDAY
NIGHT THANKS TO CLOUDS REMAINING IN PLACE.
SUNDAY AND SUNDAY NIGHT...20.00Z GFS/NAM/UKMET/ECMWF/CANADIAN ALL
SHOW ANOTHER SHORTWAVE DROPPING DOWN THE EAST SIDE OF THE WESTERN
U.S. RIDGE. AGAIN...THE MODELS DIFFER WITH THE TRACK...UKMET
FARTHEST WEST NEAR I-35 WITH THE NAM FARTHEST EAST OVER SOUTHWEST
WISCONSIN. IN ANY EVENT...THIS SHORTWAVE COMES THROUGH DURING THE
DAYTIME HOURS. WITH THAT INVERTED SURFACE TROUGH IN PLACE AND
DAYTIME HEATING...SHOULD SEE SOME ISOLATED/SCATTERED SHOWERS
DEVELOP. IF THERE IS ANYTHING GOING AGAINST PRECIPITATION IS A
NORTHEAST TO SOUTHWEST ORIENTED SURFACE RIDGE PROGGED TO BUILD INTO
THE AREA DURING THE AFTERNOON. A DRYING NORTHEAST FLOW COULD LIMIT
SOME OF THE AREAL COVERAGE OF PRECIPITATION...AS SUGGESTED IN 20.00Z
GFS OUTPUT. THEREFORE...FOR NOW CHANCES ARE ONLY 20-30. THE DRYING
FLOW PLUS DAYTIME MIXING SHOULD ALLOW FOR SOME DECREASE IN
CLOUDS...THOUGH A BETTER SHOT OF CLEARING SHOULD COME SUNDAY NIGHT
WITH SUBSIDENCE IN THE WAKE OF THE SHORTWAVE. REGARDING
TEMPERATURES...850MB READINGS ON SUNDAY ARE SIMILAR TO SATURDAY...0
TO -2C. WITH OVERALL LIMITED SUN...ANTICIPATE ANOTHER RELATIVELY
COOL DAY WITH HIGHS IN THE 50S. IF MORE SUN OCCURS THAN
EXPECTED...READINGS MAY GET INTO THE 60S. WITH CLEARING SUNDAY NIGHT
AND THE RIDGE SETTLING IN...COULD SEE YET ANOTHER FROST/FREEZE
NIGHT...ESPECIALLY FOR SOUTHWEST AND CENTRAL WISCONSIN.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
333 AM CDT FRI APR 20 2012
DIFFICULT LONG TERM FORECAST...ESPECIALLY GETTING INTO THE MIDDLE OF
NEXT WEEK WHERE MODELS ARE ALL OVER THE PLACE WITH THE HANDLING OF
THE UPPER LEVEL PATTERN OVER THE UPPER MISSISSIPPI RIVER VALLEY
REGION. THROUGH ABOUT TUESDAY...MODELS ARE IN GOOD AGREEMENT
MAINTAINING WESTERN RIDGING AND TROUGHING OVER THE EAST COAST OF THE
U.S.. 500MB HEIGHTS DO RISE MONDAY THROUGH TUESDAY WHICH WILL HELP
TO BRING WARMER AIR INTO THE FORECAST AREA. BY 00Z WEDNESDAY...850MB
TEMPS CLIMB TO 4-8C...IF NOT A LITTLE HIGHER. STILL HAVING TO
MAINTAIN SOME CHANCES OF PRECIPITATION TUESDAY NIGHT...DUE TO A
SHORTWAVE PROGGED TO COME THROUGH THE NORTHWEST FLOW. 20.00Z
ECMWF/GEM ARE PRETTY ACTIVE WITH THIS SHORTWAVE TOO...RESULTING FROM
FAVORABLE DYNAMICAL FORCING. WHAT HAPPENS IN THE WAKE OF THIS
FEATURE IS ANYONES GUESS RIGHT NOW. THE 20.00Z ECMWF IS STUCK WITH
TROUGHING FROM HUDSON BAY DOWN INTO THE EASTERN GREAT LAKES...
MAINTAIN A COOL NORTHWEST FLOW. WOULD PROBABLY END UP WITH
PERIODIC RAIN SHOWERS WITH SHORTWAVES MOVING THROUGH IN THE ECMWF
SCENARIO. ON THE OTHER HAND...THE 20.00Z GFS/GFS ENSEMBLES SAY
WEDNESDAY THROUGH THURSDAY THE WESTERN RIDGE TRIES TO BUILD
TOWARDS THE AREA...BEING PUSHED MORE BY TROUGHING COMING INTO THE
WEST COAST. IF THIS HAPPENS...PERIODIC SHOWER AND THUNDERSTORMS
CHANCES WOULD RESULT AS A WARM FRONT APPROACHES THE REGION. THE
SOLUTIONS ALSO ARE MUCH WARMER THAN THE ECMWF. FOR NOW...HAVE
SPLIT THE DIFFERENCE BETWEEN THE TWO SOLUTIONS. NEEDLESS TO
SAY...CONFIDENCE ON THE PRECIPITATION AND TEMPERATURE FORECASTS IS
LOW.
&&
.AVIATION...TODAY INTO SATURDAY
626 AM CDT FRI APR 20 2012
SYSTEM RESPONSIBLE FOR THE MVFR/IFR CONDITIONS/RAIN THU AFTERNOON/
EVENING WILL MOVE EAST/SOUTH OF THE TAF SITES THIS MORNING WITH GOOD
VFR EXPECTED AT BOTH SITES BY 15Z. WITH THE RECENT RAINS AND COOLER
HIGH PRESSURE BUILDING INTO THE AREA AND DEEP MIXING/STEEP SFC TO
850-800MB LAPSE RATES FOR THE AFTERNOON...FEW-SCT VFR CUMULUS
EXPECTED THRU THE AFTERNOON. THE DEEP MIXING WILL ALLOW FOR SOME
18-22KT WIND GUSTS AS WELL DURING THE AFTERNOON HOURS. WINDS QUICKLY
DIMINISH THIS EVENING AS THE BOUNDARY LAYER COOLS AND SFC RIDGE AXIS
BUILDING INTO THE AREA. SFC RIDGE AXIS MOVES QUICKLY ACROSS THE
AREA...WITH ONLY A BRIEF PERIOD OF LIGHT/VARIABLE OR CALM WINDS
EXPECTED. WITH WINDS RATHER QUICKLY BECOMING SOUTHEAST LATE
TONIGHT...THIS WILL LIMIT THE THREAT OF BR/FG AT BOTH KRST/KLSE LATE
TONIGHT/EARLY SAT MORNING. MID/HIGH LEVEL MOISTURE AHEAD OF THE NEXT
LOW/SHORTWAVE SPREADS INTO THE AREA LATE TONIGHT/SAT MORNING. BULK
OF THIS AT OR ABOVE 600MB /12K FT/ THRU 12Z SAT. MOISTURE INCREASES/
LOWERS THRU THE DAY SAT AS THE NEXT LOW/SHORTWAVE MOVE EAST INTO THE
REGION...WITH SCT -SHRA IN/AROUND THE AREA BY SAT AFTERNOON. CIGS/
VSBYS EXPECTED TO REMAIN VFR THRU MID-DAY SAT...WITH SCT MVFR
CIGS/VSBYS IN -SHRA SAT AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
333 AM CDT FRI APR 20 2012
WI...FREEZE WARNING FROM 1 AM TO 8 AM CDT SATURDAY FOR
WIZ017-029-034-042>044-053-055.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
334 AM CDT FRI APR 20 2012
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
333 AM CDT FRI APR 20 2012
MAIN FORECAST CONCERNS ARE ON FROST/FREEZE TONIGHT AND NEXT EXPECTED
RAIN SATURDAY/SATURDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING BUILDING UP OVER THE WESTERN U.S....TROUGHING FROM
MINNESOTA SOUTH INTO TEXAS...AND RIDGING ALONG THE EAST COAST OF THE
U.S. WITHIN THE TROUGHING...MAIN FEATURES OF NOTE INCLUDE SHORTWAVES
OVER THE EASTERN SIDE OF THE FORECAST AREA AND BACK OVER WESTERN
SOUTH DAKOTA INTO NORTHWEST NEBRASKA. THE LATTER SHORTWAVE HAS
HELPED PUSH THE LOW TO MID LEVEL FRONTOGENESIS ZONE AND DEEP
MOISTURE SEEN ON THE 00Z GRB SOUNDING EASTWARD. REGARDING THAT
FRONTOGENESIS ZONE...THIS IS EASILY SEEN IN 00Z RAOBS AT 850MB WITH
0C AT MPX...3C AT GRB AND 12C AT DVN. IN ADDITION...AN UPPER JET
STREAK OF 100-110 KT IN EASTERN ONTARIO LAST EVENING...AIDING IN
FORCING FOR PRECIPITATION ACROSS WISCONSIN...HAS BEEN PUSHED
EASTWARD BY THE SHORTWAVE. LATEST RADAR MOSAIC SHOWS JUST A LITTLE
LIGHT RAIN/SNOW IN A WEAKENING COLD CONVEYOR BELT IN CENTRAL
WISCONSIN. TO THE WEST...SUBSIDENCE AND DRYING HAS BEEN CLEARING
SKIES OUT ACROSS MINNESOTA. A SURFACE RIDGE OF HIGH PRESSURE HAS
ALSO BEEN DROPPING SOUTH INTO THE DAKOTAS AND WESTERN MINNESOTA.
FARTHER WEST...A FEW SHOWERS CONTINUE BACK OVER CENTRAL SOUTH
DAKOTA AHEAD OF THE SHORTWAVE THERE. LAST ITEM OF NOTE IS A
SHORTWAVE ON WATER VAPOR COMING INTO SOUTHERN BRITISH COLUMBIA.
TODAY AND TONIGHT...UPPER TROUGHING OVER MINNESOTA WILL SLIDE EAST
ACROSS THE THE FORECAST AREA TODAY...ALLOWING THE SURFACE RIDGE OF
HIGH PRESSURE TO BUILD INTO THE FORECAST AREA THIS EVENING. THIS
SHOULD ALLOW FOR CLEARING AND DRYING. TEMPERATURES ARE LIKELY TO NOT
END UP MUCH HIGHER THAN YESTERDAY BECAUSE 850MB TEMPS ARE -2 TO
-3C...BUT MORE SUN AND THE LACK OF RAIN WILL MAKE IT FEEL WARMER.
QUESTION TONIGHT IS FROST/FREEZE. HAVING THE SURFACE RIDGE OVER
THE AREA IN THE EVENING IS GOOD FOR GETTING COLD...BUT THERE IS AN
ISSUE LURKING UPSTREAM. THE SHORTWAVE COMING INTO SOUTHERN BRITISH
COLUMBIA MODELS SHOW TOPPING THE WESTERN U.S. RIDGE TODAY...THEN
DROPPING INTO THE EASTERN DAKOTAS BY 12Z SATURDAY. ANTICIPATING A
STREAM OF MID AND HIGH LEVEL CLOUD COVER TO SPREAD DOWNSTREAM
AHEAD OF THIS SHORTWAVE...MOVING INTO THE FORECAST AREA AFTER
MIDNIGHT. IT APPEARS LOCATIONS ACROSS SOUTHWEST INTO CENTRAL
WISCONSIN WILL STAY THE CLEAREST THE LONGEST...AND THE SURFACE
RIDGE IS EXPECTED TO STAY IN PLACE THERE TOO. THEREFORE... FEEL
THIS AREA HAS THE BEST POTENTIAL FOR FREEZE CONDITIONS WITH
AREAS/WIDESPREAD FROST. FREEZE WARNINGS NOTED IN THE WWA SECTION
BELOW. ANOTHER POTENTIAL ISSUE TO CONTEND WITH MIGHT BE FOG GIVEN
RECENT RAINS. NOT VERY CONFIDENT TO INCLUDE FOG AT THIS TIME...
EITHER FOR RADIATIONAL INDUCED OR IN THE VALLEYS...AS THERE SHOULD
BE DECENT DRYING TODAY.
SATURDAY AND SATURDAY NIGHT...SHORTWAVE OVER THE EASTERN DAKOTAS
LOOKS TO CONTINUE ITS SOUTHEASTWARD TREK DOWN THE UPPER RIDGE. THE
20.00Z NAM IS AN OUTLIER WITH ITS TRACK...MOVING INTO WISCONSIN
TONIGHT. THE 20.00Z GFS/UKMET/ECMWF ALL TAKE A FARTHER WEST TRACK
THROUGH SOUTHEAST MINNESOTA AND NORTHEAST IOWA TONIGHT WHICH SEEMS
MORE REASONABLE. ISENTROPIC LIFT ASSOCIATED WITH THE SHORTWAVE...
BEST SEEN ON 290-300K SURFACES...WILL MOVE INTO SOUTHEAST MINNESOTA
AND NORTHEAST IOWA ON SATURDAY. SHOULD EVENTUALLY SEE RAIN DEVELOP
AS LOW LEVELS MOISTEN. AFTERNOON SEEMS MOST LIKELY TO SEE RAIN.
ANOTHER FAVORABLE FORCING MECHANISM IS A 120KT UPPER JET DROPPING
DOWN INTO SOUTHWEST MINNESOTA...PLACING LOCATIONS WEST OF THE
MISSISSIPPI RIVER IN UPPER DIVERGENCE. NICE LOW TO MID LEVEL
FRONTOGENESIS/FRONTOLYSIS COUPLET SHOWS UP TOO. BOTH THE ISENTROPIC
LIFT AND UPPER JET FORCING DIMINISHES SATURDAY NIGHT...WHICH WOULD
SUGGEST PRECIPITATION SHOULD DIMINISH. THE LOW TO MID LEVEL
FRONTOGENESIS LINGERS...THOUGH...NOTED TOO BY AN INVERTED TROUGH AT
THE SURFACE LINGERING BACK INTO WESTERN MINNESOTA. THEREFORE...
SHOULD STILL SEE SOME LIGHT PRECIPITATION AFTER MIDNIGHT. GIVEN THE
STRONG FORCING SIGNALS...HAVE RAISED PRECIPITATION CHANCES
UP...ESPECIALLY WEST OF THE MISSISSIPPI RIVER. PRECIPITABLE WATER
VALUES ARE NOT THAT IMPRESSIVE...0.5-0.6 INCHES...WHICH MEANS WE
SHOULD NOT SEE MUCH QPF. ONLY CONCERN THAT EXISTS IS THE
PRECIPITATION COULD SHIFT WESTWARD OVER THE NEXT 24-48 HOURS SEEING
MODEL TRENDS. WITH PLENTY OF CLOUDS SPREADING IN SATURDAY MORNING
AND 850MB TEMPS OF 0 TO -2C ON SATURDAY...ANTICIPATING COOL
TEMPERATURES. ONLY 5 TO 10 DEGREES OF COOLING EXPECTED SATURDAY
NIGHT THANKS TO CLOUDS REMAINING IN PLACE.
SUNDAY AND SUNDAY NIGHT...20.00Z GFS/NAM/UKMET/ECMWF/CANADIAN ALL
SHOW ANOTHER SHORTWAVE DROPPING DOWN THE EAST SIDE OF THE WESTERN
U.S. RIDGE. AGAIN...THE MODELS DIFFER WITH THE TRACK...UKMET
FARTHEST WEST NEAR I-35 WITH THE NAM FARTHEST EAST OVER SOUTHWEST
WISCONSIN. IN ANY EVENT...THIS SHORTWAVE COMES THROUGH DURING THE
DAYTIME HOURS. WITH THAT INVERTED SURFACE TROUGH IN PLACE AND
DAYTIME HEATING...SHOULD SEE SOME ISOLATED/SCATTERED SHOWERS
DEVELOP. IF THERE IS ANYTHING GOING AGAINST PRECIPITATION IS A
NORTHEAST TO SOUTHWEST ORIENTED SURFACE RIDGE PROGGED TO BUILD INTO
THE AREA DURING THE AFTERNOON. A DRYING NORTHEAST FLOW COULD LIMIT
SOME OF THE AREAL COVERAGE OF PRECIPITATION...AS SUGGESTED IN 20.00Z
GFS OUTPUT. THEREFORE...FOR NOW CHANCES ARE ONLY 20-30. THE DRYING
FLOW PLUS DAYTIME MIXING SHOULD ALLOW FOR SOME DECREASE IN
CLOUDS...THOUGH A BETTER SHOT OF CLEARING SHOULD COME SUNDAY NIGHT
WITH SUBSIDENCE IN THE WAKE OF THE SHORTWAVE. REGARDING
TEMPERATURES...850MB READINGS ON SUNDAY ARE SIMILAR TO SATURDAY...0
TO -2C. WITH OVERALL LIMITED SUN...ANTICIPATE ANOTHER RELATIVELY
COOL DAY WITH HIGHS IN THE 50S. IF MORE SUN OCCURS THAN
EXPECTED...READINGS MAY GET INTO THE 60S. WITH CLEARING SUNDAY NIGHT
AND THE RIDGE SETTLING IN...COULD SEE YET ANOTHER FROST/FREEZE
NIGHT...ESPECIALLY FOR SOUTHWEST AND CENTRAL WISCONSIN.
.LONG TERM...MONDAY THROUGH THURSDAY NIGHT
333 AM CDT FRI APR 20 2012
DIFFICULT LONG TERM FORECAST...ESPECIALLY GETTING INTO THE MIDDLE OF
NEXT WEEK WHERE MODELS ARE ALL OVER THE PLACE WITH THE HANDLING OF
THE UPPER LEVEL PATTERN OVER THE UPPER MISSISSIPPI RIVER VALLEY
REGION. THROUGH ABOUT TUESDAY...MODELS ARE IN GOOD AGREEMENT
MAINTAINING WESTERN RIDGING AND TROUGHING OVER THE EAST COAST OF THE
U.S.. 500MB HEIGHTS DO RISE MONDAY THROUGH TUESDAY WHICH WILL HELP
TO BRING WARMER AIR INTO THE FORECAST AREA. BY 00Z WEDNESDAY...850MB
TEMPS CLIMB TO 4-8C...IF NOT A LITTLE HIGHER. STILL HAVING TO
MAINTAIN SOME CHANCES OF PRECIPITATION TUESDAY NIGHT...DUE TO A
SHORTWAVE PROGGED TO COME THROUGH THE NORTHWEST FLOW. 20.00Z
ECMWF/GEM ARE PRETTY ACTIVE WITH THIS SHORTWAVE TOO...RESULTING FROM
FAVORABLE DYNAMICAL FORCING. WHAT HAPPENS IN THE WAKE OF THIS
FEATURE IS ANYONES GUESS RIGHT NOW. THE 20.00Z ECMWF IS STUCK WITH
TROUGHING FROM HUDSON BAY DOWN INTO THE EASTERN GREAT LAKES...
MAINTAIN A COOL NORTHWEST FLOW. WOULD PROBABLY END UP WITH
PERIODIC RAIN SHOWERS WITH SHORTWAVES MOVING THROUGH IN THE ECMWF
SCENARIO. ON THE OTHER HAND...THE 20.00Z GFS/GFS ENSEMBLES SAY
WEDNESDAY THROUGH THURSDAY THE WESTERN RIDGE TRIES TO BUILD
TOWARDS THE AREA...BEING PUSHED MORE BY TROUGHING COMING INTO THE
WEST COAST. IF THIS HAPPENS...PERIODIC SHOWER AND THUNDERSTORMS
CHANCES WOULD RESULT AS A WARM FRONT APPROACHES THE REGION. THE
SOLUTIONS ALSO ARE MUCH WARMER THAN THE ECMWF. FOR NOW...HAVE
SPLIT THE DIFFERENCE BETWEEN THE TWO SOLUTIONS. NEEDLESS TO
SAY...CONFIDENCE ON THE PRECIPITATION AND TEMPERATURE FORECASTS IS
LOW.
&&
.AVIATION...
1100 PM CDT THU APR 19 2012
THE MAIN AREA OF RAIN WAS ALREADY EAST OF KRST AND WILL BE EAST OF
KLSE BEFORE 06Z. SOME LIGHT RAIN HAS DEVELOPED ON THE BACKSIDE OF
THIS LARGER RAIN SHIELD THOUGH...BUT VSBYS HAVE TRENDED TOWARD P6SM.
KRST/KLSE WILL HAVE TO DEAL WITH THIS THROUGH ABOUT 09-10Z.
LOW CIGS SHOULD GIVE WAY TO VFR CONDITIONS BETWEEN 14-16Z...WITH
THESE CONDITIONS PERSISTING THROUGH FRIDAY NIGHT. WINDS WILL STAY UP
THROUGH THE OVERNIGHT AS THE TIGHT PRESSURE GRADIENT WITH THE
EXITING LOW PRESSURE SYSTEM REMAINS. EVENTUAL SUNSHINE ON FRIDAY
WILL PROMOTE MIXING AND LIKELY SOME GUSTINESS FROM LATE MORNING
THROUGH THE AFTERNOON. LOOK FOR LIGHTER WINDS FRIDAY NIGHT WITH
DECOUPLING AND AN AREA OF HIGH PRESSURE BUILDING IN FROM THE WEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
333 AM CDT FRI APR 20 2012
WI...FREEZE WARNING FROM 1 AM TO 8 AM CDT SATURDAY FOR WIZ017-029-034-
042>044-053-055.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
316 AM CST SUN APR 22 2012
.SYNOPSIS...
06Z SFC ANALYSIS HAS WEAK LOWS FROM SOUTHERN MINNESOTA INTO SOUTH
CENTRAL IOWA. AN INVERTED TROF RAN FROM A LOW NEAR KMCW SOUTHEAST TO
KSPI. DEW POINTS WERE IN THE 40S AROUND THE INVERTED TROF WITH 30S
OVER MOST OF THE GREAT LAKES AND NORTHERN PLAINS.
RADAR TRENDS THE PAST SEVERAL HOURS SHOW A GENERAL WEAKENING OF THE
PRECIPITATION WITH MAINLY LIGHT RAIN AND SPRINKLES AROUND THE
INVERTED TROF.
&&
.SHORT TERM...TODAY AND TONIGHT
SFC DATA AND RUC TRENDS INDICATE MOST OF THE PRECIPITATION ACROSS
THE CWFA IS ASSOCIATED WITH THE INVERTED TROF. THE RUC DOES HAVE
STRONG FORCING ON THE 295K THETA SFC WHICH APPEARS IS RESPONSIBLE
FOR THE WEAK BAND OF SPRINKLES/-RA TO THE EAST OF THE INVERTED TROF.
RUC TRENDS SHOW THIS FORCING WEAKENING THROUGH SUNRISE AS THE
INVERTED TROF SLOWLY MOVES TO THE SOUTH AND WEST. THUS ANY
PRECIPITATION SHOULD BE CONFINED TO ROUGHLY THE SOUTHWEST HALF OF
THE CWFA AFTER SUNRISE.
THE INVERTED TROF GENERALLY EXITS THE CWFA BY MID MORNING AND THE
OVERALL FORCING/CONVERGENCE WEAKENS FURTHER. THUS MOST IF NOT ALL
THE PRECIPITATION SHOULD BE OVER BEFORE MID DAY. QUIET AND THEN
MAINLY DRY CONDITIONS SHOULD BE SEEN ACROSS THE AREA DURING THE
AFTERNOON.
TONIGHT...QUIET CONDITIONS WILL BE SEEN ACROSS THE CWFA.
INTERESTINGLY...THE HEAVY RAIN AND MCS TOOLS BRING CONVERGENCE AND
HIGHER RH DOWN ACROSS THE AREA. THE RH IS TRACEABLE TO THE LOW AND
MID CLOUDS CURRENTLY ACROSS NORTHERN MINNESOTA. SO...IT IS
CONCEIVABLE THAT A SUBTLE SHORTWAVE TOPPING THE RIDGE MAY BRING DOWN
THESE CLOUDS INTO THE AREA. IF CORRECT...THE CLOUDS SHOULD BREAK UP
SOMEWHAT DUE TO THE SUBSIDENCE OVER THE WESTERN GREAT LAKES IN THE
WAKE OF THE DEVELOPING EAST COAST STORM. ..08..
.LONG TERM...MONDAY THROUGH NEXT SATURDAY
MONDAY WE REMAIN IN THE STRONG NORTHWEST FLOW AS THE STORM SYSTEM
OVER THE EAST COAST DEEPENS AND CAUSES THE FLOW TO AMPLIFY STRONGLY
OVER THE CONUS. THIS WILL ACT TO FUNNEL COOLER THAN NORMAL AIR DOWN
INTO THE REGION INTO TUESDAY. THERE IS SOME POTENTIAL FOR SOME
DIURNALLY DRIVEN SHOWERS ON MONDAY AFTERNOON WITH THE SURFACE RIDGE
STILL TO THE WEST AND SOME WEAK CONVERGENCE TO HELP START THEM OFF.
BY TUESDAY THE SURFACE RIDGE WILL HAVE SHIFTED EAST OF THE AREA SO
THIS IS LESS OF A CONCERN AND HAVE PUT IN A DRY FORECAST AND WARMER
TEMPERATURES.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. A SHORTWAVE MOVES OVER THE
TOP OF THE UPPER LEVEL RIDGE TO OUR WEST DROPS DOWN IN THE NORTHWEST
FLOW. THIS...COMBINED WITH THE BAROCLINIC ZONE OVER THE AREA AS A
RESULT OF THE COLD AIR POOL TO OUR EAST SHOULD ACT TO GENERATE SOME
FRONTOGENESIS AS THIS FEATURES MOVES ON BY. TUESDAY NIGHT THE WARM
AIR ADVECTION/ISENTROPIC LIFT SHOWERS SHOULD BE MOVING INTO THE
AREA. THE SURFACE LOW MOVES ACROSS IOWA DURING THE DAY ON
WEDNESDAY...AND WE WILL HAVE THE COLD SIDE OF THE SYSTEM MOVE ACROSS
WEDNESDAY NIGHT. THERE ARE SOME CONCERNS THAT THE BULK OF THIS
SYSTEM WILL AFFECT AREAS NORTHEAST OF THE CWA DEPENDING ON THE
MODEL YOU LOOK AT...SO THE FORECAST IS STILL FOR JUST CHANCE POPS.
TEMPERATURES WITH THIS SYSTEM WILL BE WARMER THAN NORMAL TUESDAY
NIGHT AND WEDNESDAY...WITH COLDER TEMPS FOR WEDNESDAY NIGHT AS THE
TRAILING COLD FRONT MOVES THROUGH. THURSDAY TO BE COLDER AGAIN
BEHIND THE EXITING SYSTEM.
THURSDAY NIGHT THROUGH NEXT SATURDAY...HERE MORE QUESTION MARKS
ENTER THE FORECAST WITH MORE DIFFERENCES IN THE MODELS. THE UPPER
LEVEL RIDGE TO OUR WEST DURING THE MIDDLE OF THE WEAK BECOMES RATHER
PINCHED...AND IT GETS BODILY SHOVED EAST AS A FAIRLY POTENT UPPER
LOW SWINGS ACROSS THE FOUR CORNERS STATES. BY SATURDAY MORNING THE
MODELS ARE PUSHING A WARM AIR ADVECTION WING OF PRECIPITATION INTO
THE FORECAST AREA. WOULD NOT BE TOO SURPRISED TO SEE THIS SLOW DOWN
SOME...THOUGH THE MODELS HAVE BEEN FAIRLY CONSISTENT SO FAR.
LE
&&
.AVIATION...
MODELS SHOW THE OVERALL FORCING WILL CONTINUE TO WEAKEN THROUGH
12Z/22. THUS VFR CONDITIONS SHOULD BE SEEN FOR ALL TAF SITES. THERE
MAY BE SOME VERY BRIEF PERIODS OF MARGINAL MVFR CONDITIONS AT
KCID/KBRL THROUGH 15Z/22 AND THIS WILL BE EVALUATED FURTHER FOR THE
12Z TAFS. AFT 00Z/23 THE MODELS SHOW GENERALLY LIGHT WINDS WITH A
WEAK AREA OF CONVERGENCE AT THE SURFACE. THIS CONVERGENCE MAY BE A
SIGNAL FOR POTENTIAL MVFR VSBYS DVLPG AFT 06Z/23. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1138 PM CDT SAT APR 21 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
PRIMARY CONCERN TONIGHT WILL BE THE EVOLUTION OF UPSTREAM SHORT
WAVE/PV ANOMALY...WHICH MODELS BRING RIGHT THROUGH IA LATER
TONIGHT. CURRENT MORE THERMODYNAMICALLY FORCED BAND OF PRECIP
SHOULD EXIT ERN FORECAST AREA BY 00Z FOLLOWED BY LINE OF SCATTERED
SHOWERS/STORMS FOCUSED ON LOW LEVEL CONVERGENCE WITH PASSAGE OF
TROUGH. 20Z SURFACE ANALYSIS PLACES ACTUAL COLD FRONT FROM LOW NEAR
FARGO BACK ALONG ND/SD BORDER. COULD SEE SOME BELOW SEVERE CRITERIA
HAIL/WIND WITH THESE STORMS NW...BUT DECREASING/INCREASING
MLCAPE/CIN RESPECTIVELY SHOULD GRADUALLY WEAKEN STORMS AS THEY GET
INTO CENTRAL IA. RUC MLCAPE APPEARS TO PEAK AT NO MORE THAN 300
J/KG AS IT ENTER FORECAST AREA. ATTENTION WILL THEN TURNS TO
FORCING AND MOISTURE 3KM AND BELOW ASSOCIATED WITH PASSAGE OF SHORT
WAVE WHICH MAINLY APPEARS TO AFFECT NERN HALF OF IA. HAVE HIGH
CHANCE/LIKELY POPS TONIGHT IN THESE AREAS...BUT FEEL THIS WILL BE
FOR A TRANSIENT LOW QPF EVENT.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
AMPLIFIED UPPER PATTERN OVER THE CONUS EARLY NEXT WEEK WITH UPPER
RIDGE CENTERED OVER THE CENTRAL ROCKIES AND A DEEP UPPER TROUGH OVER
THE EASTERN UNITED STATES. SHORTWAVE OVER THE UPPER MIDWEST TODAY IS
FORECAST TO CURVE OUT A DEEP UPPER LOW CENTERED NEAR THE EAST COAST
BY MONDAY. THIS WILL LEAVE CENTRAL IOWA IN INITIALLY NORTHERLY
UPPER FLOW WHICH SHOULD SLOWLY BECOME NORTHWESTERLY BY
TUESDAY/WEDNESDAY AS A SHORTWAVE FLATTENS THE UPPER RIDGE TO THE
WEST. THE MODELS SEEM TO BE IN FAIR AGREEMENT WITH THE GENERAL UPPER
PATTERN...BUT THERE ARE DIFFERENCES MID WEEK CONCERNING THE PASSAGE
OF A SIGNIFICANT COLD FRONT. THE 12Z OPERATIONAL GFS BRINGS A
STRONG CANADIAN HIGH DOWN INTO THE UPPER MIDWEST DURING THE
WEDNESDAY THROUGH FRIDAY TIME PERIOD. THE 12Z ECMWF IS SIMILAR TO
THE 12Z GFS CONCERNING THE PLACEMENT AND STRENGTH OF THE CANADIAN
HIGH.
12Z NAM/GFS BOTH LINGER PRECIPITATION OVER CENTRAL IOWA ON SUNDAY IN
THE VICINITY OF AN INVERTED TROUGH. THE TROUGH SHOULD WEAKEN DURING
THE DAY AS THE SURFACE RIDGE BUILDS IN. EXPECT CLOUDS ON SUNDAY
WITH SMALL SHOWER CHANCES THROUGH NOON. SKIES SHOULD CLEAR SUNDAY
NIGHT UNDER APPROACHING HIGH ALLOWING TEMPERATURES TO FALL NEAR
FREEZING IN SPOTS. CONDITIONS SHOULD BE FAVORABLE FOR FROST...LIGHT
WINDS AND CLEAR SKIES.
AS THE UPPER FLOW FLATTENS BY TUESDAY AND SURFACE AND LOW-LEVEL FLOW
BECOMES WEST SOUTHWEST WITH STRONG WARM ADVECTION...EXPECT
TEMPERATURES TO WARM INTO THE 80S OVER WESTERN IOWA.
MODEL UNCERTAINTY IN THE LONG RANGE...DAY SIX AND SEVEN...WILL
RESULT IN MODERATE POPS. NEXT WESTERN CONUS UPPER TROUGH AND
ACCOMPANYING SURFACE FEATURES SHOULD IMPACT CENTRAL IOWA DURING THIS
TIME PERIOD. IN ALL CASES...THE PATTERN SHOULD BECOME FAVORABLE FOR
THUNDERSTORMS BY THE END OF THE FORECAST PERIOD.
&&
.AVIATION...22/06Z
SHORTWAVE WILL CONTINUE TO PRESS FURTHER EAST OVERNIGHT. FAIRLY
SHARP PRESSURE PRESSURE GRADIENT SHOULD CAUSE SOME GUSTY WINDS AT
FOD/MCW/DSM AREAS BY AROUND 08Z...WITH MVFR CIGS MOVING IN WITH THE
CAA. HAVE MENTION OF MVFR CIGS AT FOD/MCW/DSM/ALO B/T 07-10Z...BUT
KEPT WINDS DOWN AT ALO AS TROUGH LOOKS TO PUSH THROUGH SUNDAY
MORNING. CONFIDENT STRATUS WILL STICK AROUND UNTIL AT LEAST NEXT
FORECAST UPDATE...AND LIKELY INTO THE LATE MORNING HOURS SUNDAY.
HAVE CONDITIONS IMPROVING AFTER 15Z SUNDAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...JOHNSON
AVIATION...PODRAZIK
AREA FORECAST DISCUSSION
NWS ALBANY NY
149 AM EDT SUN APR 22 2012
.SYNOPSIS...
A COLD FRONT CONTINUES TO MOVE SOUTHEAST OF SOUTHERN NEW YORK AND
NEW ENGLAND THIS MORNING...AS A WAVE OF LOW PRESSURE MOVING ALONG IT
CONTINUES TO BRING THE FIRST WIDESPREAD MEASURABLE RAINFALL SINCE
APRIL FIRST. A BRIEF LULL IN THE RAIN WILL OCCUR SUNDAY MORNING. AN
INTENSIFYING AREA OF LOW PRESSURE WILL APPROACH FROM THE MID
ATLANTIC REGION SUNDAY AFTERNOON...AND MOVE ACROSS THE REGION MONDAY
BRINGING A WIDESPREAD SOAKING RAINFALL AND BREEZY CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 105 AM...LATEST RUC40 SHOWS SFC LOW MOVING ACROSS RI AND ERN
MA ALONG THE FRONTAL BOUNDARY THAT HAS CLEARED MOST OF THE FCST
AREA. COLDER AIR CONTINUES TO OOZE IN FROM THE NORTHWEST WITH SOME
SNOW BEING REPORTED ON KSLK. THE LATEST REGIONAL AND LOCAL KENX
RADAR IMAGERY SHOWS THE BACK EDGE OF THE PCPN MOVING ACROSS THE
SRN DACKS AND THE WRN MOHAWK VALLEY. THIS SEEMS IN IN SYNC WITH
THE LATEST HRRR 3-KM REF PRODUCT AND THE 00Z NAM. THE HOURLY POPS
WERE RETRENDED ACROSS THE REGION WITH THE PCPN DIMINISHING BTWN
06Z- 09Z...EXCEPT FOR SOME LIGHT RAIN REMAINING OVER THE E/SE
ZONES FROM THE CAPITAL REGION. WE WENT INTO MID-DAY SUNDAY TO
RETREND AND SLOW DOWN THE RAIN RETURNING UNTIL THE AFTERNOON.
THE CURRENT PCPN WAS ENHANCED BY THE LEFT FRONT QUADRANT OF AH
H250 JET STREAK OF 100-120 KTS MOVING ACROSS CNTRL-ERN NY.
RAINFALL REPORTS HAVE RANGED FROM A HALF AN INCH TO UP TO AN INCH
A THIRD FROM THE ERN CATSKILLS NORTHEAST THROUGH THE CAPITAL
REGION...SARATOGA REGION...AND INTO THE NRN TACONICS. THIS IS A
BENEFICIAL RAINFALL AFTER THE PERSISTENT DRY WEATHER THE PAST 3 TO
6 WEEKS. MORE IS ON THE WAVE WITH AN IMPRESSIVE COASTAL WAVE LATER
TODAY THROUGH MONDAY.
LOOK FOR OVERNIGHT LOWS IN THE U30S TO M40S IN MOST PLACES...BUT
LOWER TO MID 30S WELL NORTH AND WEST OF ALBANY OVER THE ADIRONDACK
PARK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
...A STRONG SPRING STORM TO IMPACT THE REGION...
H2O VAPOR LOOP REVEALS THE WEATHER ELEMENTS...A POTENT UPPER LOW
THAT WAS TRACKING ACROSS THE GULF OF MEXICO. A 130+KT UPPER WAS
QUICKLY DIVING SOUTHEAST ACROSS THE PLAINS TOWARD THE MID
MISSISSIPPI RIVER VALLEY. AN ACTIVE COASTAL FRONT ALONG THE
ATLANTIC COASTLINE WAS ALSO IN PLACE TODAY. THESE SYSTEMS ARE
EXPECTED TO PHASE OVER THE SOUTHEAST CONUS WITH A DEEPENING
SURFACE LOW TRACKING NORTHEAST ALONG THE SEABOARD /A NOR`EASTER/.
BEFORE THIS SYSTEM IMPACTS THE REGION...THERE WILL BE A BRIEF LULL
IN THE PRECIP SUNDAY MORNING AS MAIN COLD FRONT IS EAST OF THE
AREA. WE WILL QUICKLY INCREASE THOSE POPS THROUGH THE DAY WITH
RAIN EVOLVING FROM SOUTH TO NORTH THROUGH THE DAY. PRESSURE
GRADIENT WILL BE ON THE INCREASE TOO AS SURFACE LOW DEEPENS FROM
NEAR 1000MB THIS EVENING ACROSS NORTHERN FLORIDA TO ~985MB BY 12Z
MONDAY. QPF FROM THE MODELS APPEAR TO BE SETTLING ALONG THE LINES
OF 1-3 INCHES WITH UPSLOPE ENHANCEMENTS PERHAPS ADDING ANOTHER
INCH TO THOSE TOTALS /SEE HYDRO SECTION BELOW FOR FURTHER DETAILS/.
OTHERWISE...STRONG QG FORCING AND FGEN WILL MAKE FOR BANDS OF
MODERATE TO PERHAPS HEAVY RAINFALL ACROSS THE ENTIRE REGION LATE
SUNDAY INTO EARLY MONDAY MORNING. DRY SLOT APPROACHES DURING THE
DAYLIGHT HOURS MONDAY WHICH WILL SERVE TO DECREASE THE PRECIP
COVERAGE AND INTENSITY ACROSS THE REGION. THE COMBINATION OF A
STRONG SOUTHEAST WIND...DOWNSLOPING COMPONENT COULD BRING A
COMBINATION OF A FEW BINOVCS AND WARMER TEMPERATURES FOR THE
HUDSON RIVER VALLEY.
REGARDING WINDS...AT THIS TIME NO HEADLINES DESPITE THE
STRENGTHENING SOUTH-SOUTHEAST WINDS. CLIMATOLOGY FAVORS PORTIONS
OF THE BERKS...SOUTHERN GREENS AND EASTERN CATSKILLS...BUT IT
SEEMS THE BEST JET CORE MAY REMAIN JUST TO OUR EAST AND WITHIN A
WARM ADVECTION REGIME...DIFFICULT TO MIX DOWN TO THE SURFACE. WE
WILL CONTINUE TO MONITOR TRENDS VERY CLOSELY.
AS THE SURFACE LOW TRACK NOW FURTHER INLAND ACROSS NY AND ACROSS
THE CATSKILLS...BOUNDARY LAYER TEMPERATURES APPEAR TO REMAIN AT OR
ABOVE FREEZING TO REDUCE THE THREAT OF MINOR ACCUMULATING SNOW FOR
THE HIGHER TERRAIN. THEREFORE...WE HAVE GREATLY REDUCED SNOWFALL
AMOUNTS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
CONDITIONS WILL ONLY GRADUALLY IMPROVE IN THE LONG TERM PERIOD AS
THE LOW PRESSURE SYSTEM RESPONSIBLE FOR ALL OF THE PRECIPITATION
WILL ONLY SLOWLY MOVE AWAY FROM OUR REGION. IT WILL LIKELY TAKE
UNTIL THURSDAY NIGHT AND FRIDAY BEFORE SIGNIFICANT IMPROVEMENT
OCCURS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...CUTOFF UPPER LOW OVER NORTHERN
PA MONDAY NIGHT IS EXPECTED TO DRIFT SLOWLY NORTH ACROSS WESTERN NEW
YORK AND INTO ONTARIO ON TUESDAY. MEANWHILE SURFACE LOW LIFTS FROM
WEST CENTRAL NEW YORK MONDAY EVENING TO SOUTHEAST OF JAMES BAY
TUESDAY EVENING AND THEN EAST OF HUDSON BAY LATE TUESDAY NIGHT.
EXPECT SCATTERED TO NUMEROUS RAIN AND SNOW SHOWERS WITH THE HIGHEST
POPS ACROSS THE NORTHWEST THIRD OF THE FA AND GREATEST CHANCE OF
SNOW SHOWERS AFTER MIDNIGHT MONDAY NIGHT AND TUESDAY NIGHT. LOWS ARE
EXPECTED TO BE IN THE 30S TO AROUND 40 WITH HIGHS ON TUESDAY IN THE
40S TO MID 50S.
WEDNESDAY THROUGH THURSDAY...STILL EXPECT CHANCE POPS AS A SECONDARY
TROUGH AXIS MOVES ACROSS THE AREA WHILE A FAST MOVING LOW PRESSURE
SYSTEM MOVES FROM THE CENTRAL MISSISSIPPI VALLEY WEDNESDAY MORNING
TO THE MID ATLANTIC COAST THURSDAY MORNING. ONCE AGAIN THERE WILL BE
SOME SNOW SHOWERS ACROSS THE NORTHERN MOUNTAINS ESPECIALLY AFTER
MIDNIGHT WEDNESDAY NIGHT. HIGHS WEDNESDAY AND THURSDAY ARE EXPECTED
TO BE IN THE MID 40S TO AROUND 60 WITH LOWS WEDNESDAY NIGHT IN THE
30S TO LOWER 40S...ALTHOUGH SOME UPPER 20S ARE POSSIBLE ACROSS THE
WESTERN ADIRONDACKS.
THURSDAY NIGHT AND FRIDAY...EXPECT GRADUAL IMPROVEMENT AS A RIDGE OF
HIGH PRESSURE SLOWLY BUILDS EAST INTO THE GREAT LAKES REGION. THERE
MAY STILL BE A FEW SCATTERED RAIN OR SNOW SHOWERS CONFINED TO THE
WESTERN ADIRONDACKS MAINLY THURSDAY NIGHT. EXPECT LOWS THURSDAY
NIGHT IN THE UPPER 20S TO AROUND 40 WITH HIGHS ON FRIDAY IN THE MID
40S TO AROUND 60.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THE FRONTAL BOUNDARY IS TO THE EAST OF THE LOCAL AREA WITH A WEAK
WAVE OF LOW PRESSURE MOVING ALONG IT. THE WAVE WILL MOVE OFF AND
DISSIPATE AND THE BOUNDARY WILL BECOME STALLED JUST OFF THE EAST
COAST OF NEW ENGLAND. PRECIPITATION ACROSS THE AREA WILL DIMINISH
EARLY THIS MORNING CAN SEE SIGNS OF THIS ON RADAR ALREADY. AT KGFL
AND KALB EXPECTED CEILINGS REMAIN LOW...IFR-MVFR THROUGH THE EARLY
MORNING HOURS...WITH MVFR/VFR AT KPOU. WIDESPREAD MVFR ARE EXPECTED
DURING THE DAY INTO THE EVENING.
A STRENGTHEN LOW WILL HEAD NORTHWARD ALONG THE STALLED BOUNDARY UP
THE SOUTHEAST COAST TODAY. THE LOW WILL THEN MOVE NORTHWESTWARD
TONIGHT AS ITS DRAWN IN UNDER THE UPPER LOW THAT WILL HAVE DEVELOPED
DURING THE DAY. THE SYSTEM WILL BECOME VERTICALLY STACKED OVER
CENTRAL PENNSYLVANIA OVERNIGHT. AS THE LOW APPROACHES A WIDESPREAD
RAIN WILL MOVE INTO THE REGION. THE RAIN WILL COME DOWN HEAVY AT
TIMES ESPECIALLY DURING THE EVENING LOWERING CONDITIONS TO
WIDESPREAD IFR.
NORTHERLY WINDS OF AROUND KNOTS TODAY WILL BECOME NORTHEASTERLY
TONIGHT. MAY NEED TO ADD LOW LEVEL WIND SHEAR TO TAF WITH NEXT
ISSUANCE AS A STRONG LOW LEVEL JET MOVES INTO REGION JUST IN ADVANCE
OF THE APPROACHING LOW.
.OUTLOOK...
MON...MVFR/IFR. RAIN SHOWERS IN THE MORNING BECOMING SCATTERED IN
THE AFTERNOON AND IMPROVING TO MVFR/VFR.
MON NIGHT-THU...VFR/MVFR WITH CHANCE OF SHOWERS.
&&
.FIRE WEATHER...
FIRST WIDESPREAD MEASURABLE RAINFALL EXPECTED ACROSS THE ENTIRE
REGION SINCE APRIL 1ST. AN AREA OF LOW PRESSURE WILL APPROACH FROM
THE SOUTH SUNDAY AND MOVE ACROSS THE REGION MONDAY BRINGING A
SOAKING RAINFALL WHICH WILL GREATLY DIMINISHING FIRE WEATHER
CONCERNS.
&&
.HYDROLOGY...
PER THE DROUGHT MONITOR...OUR CWA RANGED FROM D0-D3. THE UPCOMING
RAINFALL EVENT OF 1 TO 3 INCHES...WITH UP TO 4 INCHES ACROSS
FAVORABLE UPSLOPE AREAS OF THE CATSKILLS...SOUTHERN GREENS AND
PORTIONS OF THE BERKS...DROUGHT CONDITIONS ARE EXPECTED TO BE
ALLEVIATED.
A CLOSER EXAMINATION THE MMEFS AND LATEST NERFC GUIDANCE...SEVERAL
RIVER POINTS ARE FORECAST TO RISE TOWARD AND ABOVE FLOOD STAGE.
COMBINE THIS WITH PORTIONS OF THE REGION GROUNDS ABILITY TO ABSORB
WATER IN QUESTION...WE WILL HOIST A FLOOD WATCH FOR PORTIONS OF THE
REGION /MAINLY SOUTH AND EAST OF THE CAPITAL REGION/.
OTHERWISE ANTECEDENT CONDITIONS ARE VERY DRY...PRECIPITATION
DEFICITS ARE RUNNING 5 TO 10 INCHES BELOW NORMAL ACROSS EASTERN
NEW YORK AND WESTERN NEW ENGLAND. STREAMFLOW CONDITIONS ARE AT
WELL BELOW NORMAL AND RESERVOIR LEVELS ACROSS THE AREA REMAIN NEAR
TO SLIGHTLY BELOW NORMAL. THE FORECAST RAINFALL AMOUNTS ARE
EXPECTED TO PRODUCE SIGNIFICANT WITHIN BANK RISES WITH SOME MINOR
FLOODING A POSSIBILITY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
PRECIPITATION (DEPARTURE FROM NORMAL)
ALBANY NY:
MONTH TO DATE THROUGH THE 20TH: 0.14 INCHES (-2.00 INCHES)
SINCE MAR 1: 1.68 INCHES (-3.67 INCHES)
SINCE JAN 1: 4.94 INCHES (-5.20 INCHES)
GLENS FALLS NY:
MONTH TO DATE THROUGH THE 20TH: 0.32 INCHES (-1.63 INCHES)
SINCE MAR 1: 1.55 INCHES (-3.34 INCHES)
SINCE JAN 1: 4.49 INCHES (-5.34 INCHES)
POUGHKEEPSIE NY:
MONTH TO DATE THROUGH THE 20TH: 0.26 INCHES (-2.27 INCHES)
SINCE MAR 1: 1.45 INCHES (-4.65 INCHES)
SINCE JAN 1: 5.06 INCHES (-6.78 INCHES)
BENNINGTON VT:
MONTH TO DATE THROUGH THE 20TH: 0.47 INCHES (-1.79 INCHES)
SINCE MAR 1: 2.05 INCHES (-3.36 INCHES)
SINCE JAN 1: 4.55 INCHES (-5.85 INCHES)
PITTSFIELD MA:
MONTH TO DATE THROUGH THE 20TH: 0.38 INCHES (-2.47 INCHES)
SINCE MAR 1: 1.52 INCHES (-4.70 INCHES)
SINCE JAN 1: 5.73 INCHES (-6.09 INCHES)
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
CTZ001-013.
NY...FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
NYZ043-047-053-054-058>061-063>066-084.
MA...FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
MAZ001-025.
VT...FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
VTZ013>015.
&&
$$
SYNOPSIS...BGM/WASULA
NEAR TERM...WASULA
SHORT TERM...BGM
LONG TERM...11
AVIATION...IAA
FIRE WEATHER...BGM
HYDROLOGY...BGM/11
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
107 AM EDT SUN APR 22 2012
.SYNOPSIS...
A COLD FRONT CONTINUES TO MOVE SOUTHEAST OF SOUTHERN NEW
YORK AND NEW ENGLAND THIS MORNING...AS A WAVE OF LOW PRESSURE MOVING
ALONG IT CONTINUES TO BRING THE FIRST WIDESPREAD MEASURABLE RAINFALL
SINCE APRIL FIRST. A BRIEF LULL IN THE RAIN WILL OCCUR SUNDAY
MORNING. AN INTENSIFYING AREA OF LOW PRESSURE WILL APPROACH FROM
THE MID ATLANTIC REGION SUNDAY AFTERNOON...AND MOVE ACROSS THE
REGION MONDAY BRINGING A WIDESPREAD SOAKING RAINFALL AND BREEZY
CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 105 AM...LATEST RUC40 SHOWS SFC LOW MOVING ACROSS RI AND ERN
MA ALONG THE FRONTAL BOUNDARY THAT HAS CLEARED MOST OF THE FCST
AREA. COLDER AIR CONTINUES TO OOZE IN FROM THE NORTHWEST WITH SOME
SNOW BEING REPORTED ON KSLK. THE LATEST REGIONAL AND LOCAL KENX
RADAR IMAGERY SHOWS THE BACK EDGE OF THE PCPN MOVING ACROSS THE
SRN DACKS AND THE WRN MOHAWK VALLEY. THIS SEEMS IN IN SYNC WITH
THE LATEST HRRR 3-KM REF PRODUCT AND THE 00Z NAM. THE HOURLY POPS
WERE RETRENDED ACROSS THE REGION WITH THE PCPN DIMINISHING BTWN
06Z- 09Z...EXCEPT FOR SOME LIGHT RAIN REMAINING OVER THE E/SE
ZONES FROM THE CAPITAL REGION. WE WENT INTO MID-DAY SUNDAY TO
RETREND AND SLOW DOWN THE RAIN RETURNING UNTIL THE AFTERNOON.
THE CURRENT PCPN WAS ENHANCED BY THE LEFT FRONT QUADRANT OF AH
H250 JET STREAK OF 100-120 KTS MOVING ACROSS CNTRL-ERN NY.
RAINFALL REPORTS HAVE RANGED FROM A HALF AN INCH TO UP TO AN INCH
A THIRD FROM THE ERN CATSKILLS NORTHEAST THROUGH THE CAPITAL
REGION...SARATOGA REGION...AND INTO THE NRN TACONICS. THIS IS A
BENEFICIAL RAINFALL AFTER THE PERSISTENT DRY WEATHER THE PAST 3 TO
6 WEEKS. MORE IS ON THE WAVE WITH AN IMPRESSIVE COASTAL WAVE LATER
TODAY THROUGH MONDAY.
LOOK FOR OVERNIGHT LOWS IN THE U30S TO M40S IN MOST PLACES...BUT
LOWER TO MID 30S WELL NORTH AND WEST OF ALBANY OVER THE ADIRONDACK
PARK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
A STRONG SPRING STORM TO IMPACT THE REGION...
H2O VAPOR LOOP REVEALS THE WEATHER ELEMENTS...A POTENT UPPER LOW
THAT WAS TRACKING ACROSS THE GULF OF MEXICO. A 130+KT UPPER WAS
QUICKLY DIVING SOUTHEAST ACROSS THE PLAINS TOWARD THE MID
MISSISSIPPI RIVER VALLEY. AN ACTIVE COASTAL FRONT ALONG THE
ATLANTIC COASTLINE WAS ALSO IN PLACE TODAY. THESE SYSTEMS ARE
EXPECTED TO PHASE OVER THE SOUTHEAST CONUS WITH A DEEPENING
SURFACE LOW TRACKING NORTHEAST ALONG THE SEABOARD /A NOR`EASTER/.
BEFORE THIS SYSTEM IMPACTS THE REGION...THERE WILL BE A BRIEF LULL
IN THE PRECIP SUNDAY MORNING AS MAIN COLD FRONT IS EAST OF THE
AREA. WE WILL QUICKLY INCREASE THOSE POPS THROUGH THE DAY WITH
RAIN EVOLVING FROM SOUTH TO NORTH THROUGH THE DAY. PRESSURE
GRADIENT WILL BE ON THE INCREASE TOO AS SURFACE LOW DEEPENS FROM
NEAR 1000MB THIS EVENING ACROSS NORTHERN FLORIDA TO ~985MB BY 12Z
MONDAY. QPF FROM THE MODELS APPEAR TO BE SETTLING ALONG THE LINES
OF 1-3 INCHES WITH UPSLOPE ENHANCEMENTS PERHAPS ADDING ANOTHER
INCH TO THOSE TOTALS /SEE HYDRO SECTION BELOW FOR FURTHER DETAILS/.
OTHERWISE...STRONG QG FORCING AND FGEN WILL MAKE FOR BANDS OF
MODERATE TO PERHAPS HEAVY RAINFALL ACROSS THE ENTIRE REGION LATE
SUNDAY INTO EARLY MONDAY MORNING. DRY SLOT APPROACHES DURING THE
DAYLIGHT HOURS MONDAY WHICH WILL SERVE TO DECREASE THE PRECIP
COVERAGE AND INTENSITY ACROSS THE REGION. THE COMBINATION OF A
STRONG SOUTHEAST WIND...DOWNSLOPING COMPONENT COULD BRING A
COMBINATION OF A FEW BINOVCS AND WARMER TEMPERATURES FOR THE
HUDSON RIVER VALLEY.
REGARDING WINDS...AT THIS TIME NO HEADLINES DESPITE THE
STRENGTHENING SOUTH-SOUTHEAST WINDS. CLIMATOLOGY FAVORS PORTIONS
OF THE BERKS...SOUTHERN GREENS AND EASTERN CATSKILLS...BUT IT
SEEMS THE BEST JET CORE MAY REMAIN JUST TO OUR EAST AND WITHIN A
WARM ADVECTION REGIME...DIFFICULT TO MIX DOWN TO THE SURFACE. WE
WILL CONTINUE TO MONITOR TRENDS VERY CLOSELY.
AS THE SURFACE LOW TRACK NOW FURTHER INLAND ACROSS NY AND ACROSS
THE CATSKILLS...BOUNDARY LAYER TEMPERATURES APPEAR TO REMAIN AT OR
ABOVE FREEZING TO REDUCE THE THREAT OF MINOR ACCUMULATING SNOW FOR
THE HIGHER TERRAIN. THEREFORE...WE HAVE GREATLY REDUCED SNOWFALL
AMOUNTS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
CONDITIONS WILL ONLY GRADUALLY IMPROVE IN THE LONG TERM PERIOD AS
THE LOW PRESSURE SYSTEM RESPONSIBLE FOR ALL OF THE PRECIPITATION
WILL ONLY SLOWLY MOVE AWAY FROM OUR REGION. IT WILL LIKELY TAKE
UNTIL THURSDAY NIGHT AND FRIDAY BEFORE SIGNIFICANT IMPROVEMENT
OCCURS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...CUTOFF UPPER LOW OVER NORTHERN
PA MONDAY NIGHT IS EXPECTED TO DRIFT SLOWLY NORTH ACROSS WESTERN NEW
YORK AND INTO ONTARIO ON TUESDAY. MEANWHILE SURFACE LOW LIFTS FROM
WEST CENTRAL NEW YORK MONDAY EVENING TO SOUTHEAST OF JAMES BAY
TUESDAY EVENING AND THEN EAST OF HUDSON BAY LATE TUESDAY NIGHT.
EXPECT SCATTERED TO NUMEROUS RAIN AND SNOW SHOWERS WITH THE HIGHEST
POPS ACROSS THE NORTHWEST THIRD OF THE FA AND GREATEST CHANCE OF
SNOW SHOWERS AFTER MIDNIGHT MONDAY NIGHT AND TUESDAY NIGHT. LOWS ARE
EXPECTED TO BE IN THE 30S TO AROUND 40 WITH HIGHS ON TUESDAY IN THE
40S TO MID 50S.
WEDNESDAY THROUGH THURSDAY...STILL EXPECT CHANCE POPS AS A SECONDARY
TROUGH AXIS MOVES ACROSS THE AREA WHILE A FAST MOVING LOW PRESSURE
SYSTEM MOVES FROM THE CENTRAL MISSISSIPPI VALLEY WEDNESDAY MORNING
TO THE MID ATLANTIC COAST THURSDAY MORNING. ONCE AGAIN THERE WILL BE
SOME SNOW SHOWERS ACROSS THE NORTHERN MOUNTAINS ESPECIALLY AFTER
MIDNIGHT WEDNESDAY NIGHT. HIGHS WEDNESDAY AND THURSDAY ARE EXPECTED
TO BE IN THE MID 40S TO AROUND 60 WITH LOWS WEDNESDAY NIGHT IN THE
30S TO LOWER 40S...ALTHOUGH SOME UPPER 20S ARE POSSIBLE ACROSS THE
WESTERN ADIRONDACKS.
THURSDAY NIGHT AND FRIDAY...EXPECT GRADUAL IMPROVEMENT AS A RIDGE OF
HIGH PRESSURE SLOWLY BUILDS EAST INTO THE GREAT LAKES REGION. THERE
MAY STILL BE A FEW SCATTERED RAIN OR SNOW SHOWERS CONFINED TO THE
WESTERN ADIRONDACKS MAINLY THURSDAY NIGHT. EXPECT LOWS THURSDAY
NIGHT IN THE UPPER 20S TO AROUND 40 WITH HIGHS ON FRIDAY IN THE MID
40S TO AROUND 60.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
LOOKS AS IF MAINLY SUB-VFR CONDITIONS WILL BE THE RULE AT THE TAF
SITES THROUGH SUNDAY.
THE COLD FRONT HAS FINALLY MADE IT TO POUGHKEEPSIE SO NOW THEIR
CEILING SHOULD DROP INTO THE MVFR OR LOW MVFR RANGE. (DECIDED TO
REMOVE ANY MENTION OF IFR). NO CLOUD TO GROUND LIGHTNING LATELY SO
REMOVED THE MENTION OF THUNDER.
BEHIND THE FRONT...IFR CIGS LOOK TO HOLD AT KALB FOR AWHILE
TONIGHT...BEFORE POSSIBLE LIFTING BACK TO LOW MVFR (BELOW 2000
FEET). THAT THINKING IS NOT CERTAIN...ONLY A LITTLE BETTER THAN 50
PERCENT SO CHECK BACK IF YOU MUST INCLUDE IFR RESTRICTION LATER
TONIGHT AT KALB.
AT KGFL...IT APPEARS THAT A DOWNSLOPING NE WIND MIGHT POSSIBLY KEEP
CIGS AND EVEN VSBYS JUST ABOVE IFR. SO FAR THAT IDEA HAS WORKED.
HOWEVER...THIS IS NEARLY A 50/50 BET (WE LEANED A LITTLE HIGHER THAN
THAT) BUT KEPT THEM AT THE LOW MVFR RANGE THROUGH 08Z.
AS WE HEAD TOWARD THE MORNING PEAK ON SUNDAY...CONDITIONS LOOK TO
MARGINALLY IMPROVE AS CIGS ARE FORECAST TO LIFT BACK TO THE HIGH
LEVEL OF MVFR AND FOR AWHILE...ANY RAIN SHOULD END. ENOUGH OF A
NORTH WIND SHOULD PREVENT FOG FROM FORMING AND ANY DRIZZLE WOULD
LIKELY NOT IMPACT VSBYS OR EVEN CIGS TOO MUCH.
LATER ON SUNDAY...THE MAIN STORM WILL BEGIN TO PUSH ITS RAINSHIELD
TOWARD THE TAF SITES BY SUNDAY AFTERNOON. WE DROPPED THE TAFS BACK
FURTHER TOWARD MVFR FOR NOW...STILL JUST ABOVE THE 2000 FOOT MINIMUM
REQUIRED TO CARRY ADDITIONAL FUEL.
.OUTLOOK...
SUN NITE-MON...SUB-VFR CIG RAIN. CHC IFR IN HVY RAIN.
MON NT-WED NT...VFR CIG...CHC SUB-VFR -SHRAS.
THU...VFR. NO SIG WX.
&&
.FIRE WEATHER...
WIDESPREAD MEASURABLE RAINFALL EXPECTED ACROSS THE ENTIRE REGION
SINCE APRIL 1ST. AN AREA OF LOW PRESSURE WILL APPROACH FROM THE SOUTH
SUNDAY AND MOVE ACROSS THE REGION MONDAY BRINGING A SOAKING RAINFALL
WHICH WILL GREATLY DIMINISHING FIRE WEATHER CONCERNS.
&&
.HYDROLOGY...
PER THE DROUGHT MONITOR...OUR CWA RANGED FROM D0-D3. THE UPCOMING
RAINFALL EVENT OF 1 TO 3 INCHES...WITH UP TO 4 INCHES ACROSS
FAVORABLE UPSLOPE AREAS OF THE CATSKILLS...SOUTHERN GREENS AND
PORTIONS OF THE BERKS...DROUGHT CONDITIONS ARE EXPECTED TO BE
ALLEVIATED.
A CLOSER EXAMINATION THE MMEFS AND LATEST NERFC
GUIDANCE...SEVERAL RIVER POINTS ARE FORECAST TO RISE TOWARD AND
ABOVE FLOOD STAGE. COMBINE THIS WITH PORTIONS OF THE REGION
GROUNDS ABILITY TO ABSORB WATER IN QUESTION...WE WILL HOIST A
FLOOD WATCH FOR PORTIONS OF THE REGION /MAINLY SOUTH AND EAST OF
THE CAPITAL REGION/.
OTHERWISE ANTECEDENT CONDITIONS ARE VERY DRY...PRECIPITATION
DEFICITS ARE RUNNING 5 TO 10 INCHES BELOW NORMAL ACROSS EASTERN
NEW YORK AND WESTERN NEW ENGLAND. STREAMFLOW CONDITIONS ARE AT
WELL BELOW NORMAL AND RESERVOIR LEVELS ACROSS THE AREA REMAIN NEAR
TO SLIGHTLY BELOW NORMAL. THE FORECAST RAINFALL AMOUNTS ARE
EXPECTED TO PRODUCE SIGNIFICANT WITHIN BANK RISES WITH SOME MINOR
FLOODING A POSSIBILITY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
PRECIPITATION (DEPARTURE FROM NORMAL)
ALBANY NY:
MONTH TO DATE THROUGH THE 20TH: 0.14 INCHES (-2.00 INCHES)
SINCE MAR 1: 1.68 INCHES (-3.67 INCHES)
SINCE JAN 1: 4.94 INCHES (-5.20 INCHES)
GLENS FALLS NY:
MONTH TO DATE THROUGH THE 20TH: 0.32 INCHES (-1.63 INCHES)
SINCE MAR 1: 1.55 INCHES (-3.34 INCHES)
SINCE JAN 1: 4.49 INCHES (-5.34 INCHES)
POUGHKEEPSIE NY:
MONTH TO DATE THROUGH THE 20TH: 0.26 INCHES (-2.27 INCHES)
SINCE MAR 1: 1.45 INCHES (-4.65 INCHES)
SINCE JAN 1: 5.06 INCHES (-6.78 INCHES)
BENNINGTON VT:
MONTH TO DATE THROUGH THE 20TH: 0.47 INCHES (-1.79 INCHES)
SINCE MAR 1: 2.05 INCHES (-3.36 INCHES)
SINCE JAN 1: 4.55 INCHES (-5.85 INCHES)
PITTSFIELD MA:
MONTH TO DATE THROUGH THE 20TH: 0.38 INCHES (-2.47 INCHES)
SINCE MAR 1: 1.52 INCHES (-4.70 INCHES)
SINCE JAN 1: 5.73 INCHES (-6.09 INCHES)
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
CTZ001-013.
NY...FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
NYZ043-047-053-054-058>061-063>066-084.
MA...FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
MAZ001-025.
VT...FLOOD WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
VTZ013>015.
&&
$$
SYNOPSIS...BGM/WASULA
NEAR TERM...WASULA
SHORT TERM...BGM
LONG TERM...11
AVIATION...HWJIV
FIRE WEATHER...BGM
HYDROLOGY...BGM/11
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
133 AM EDT SUN APR 22 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 425 PM EDT SAT APR 21 2012
THE AMPLIFYING RIDGE OVER THE WRN CONUS AND THE STRENGTHENING UPPER
LOW OVER THE GULF WILL LEAD TO THE NRN STREAM TROUGH AMPLIFYING
OVER THE UPPER GREAT LKS. THIS WILL ALLOW THE NRN STREAM JET TO
STRETCH FROM SASK/ALBERTA SE INTO THE SE CONUS. WITH THIS
AMPLIFICATION AND THE SHORTWAVE NOW PUSHING INTO WRN MN AND SE INTO
ILLINOIS TONIGHT...EXPECT THE SFC LOW AND ASSOCIATED WARM FRONT PCPN
OVER WRN MN TO FOCUS FARTHER S...WHILE H850-700 WAA PCPN OVER
NERN MN WILL DIMINISH WITH THE WEAKENING LOW/WAA. THIS REFOCUSING TO
THE SE IS SEEN WELL IN THE NAM/GFS H850-500 Q-VECTOR CONV
AREAS...ALONG WITH THEIR MOISTURE FIELDS. 17Z RUC ALSO HAS A GOOD
HANDLE ON THE PCPN IN THE SHORT TERM AND WILL USE THOSE FOR THE
EVOLUTION THIS EVENING. ALL IN ALL...EXPECT THE PCPN TO STAY JUST W
OF THE CWA...DUE TO THE DRY SFC TO H850 AIR ROTATING AROUND THE
HIGH IN ONTARIO. BUT STILL EXPECT MID/HIGH CLOUDS TO CONTINUE TO
SLOWLY PUSH E OVER THE WRN THIRD OF THE CWA AND REMAIN THROUGH THE
NIGHT. ELSEWHERE...EXPECT THE DIURNAL CU TO DISSIPATE AND A MOSTLY
CLEAR NIGHT IS EXPECTED.
THE EXACT LOCATION OF THE CLOUDS WILL LARGELY DETERMINE TEMPS OVER
THE WRN HALF OF THE CWA. DID KEEP LOWS UP SOME WITH THE EXPECTED
CLOUD COVER...TOWARDS FREEZING OVER THE FAR W AND MID/UPPER 20S
TOWARDS THE W-CNTRL. LIGHT WINDS OVER THE CNTRL/EAST AND PWAT VALUES
OF 35-40 PERCENT OF NORMAL WILL LEAD TO A GOOD RADIATIONAL COOLING
NIGHT. HAVE LOWERED TEMPS OVER THE E BASED OFF LOWS LAST NIGHT AND
AFTN DEWPOINTS FALLING INTO THE UPPER TEENS AND LOWER 20S. WENT A
FEW DEGREES BELOW GUIDANCE OVER THE INTERIOR COLD SPOTS...MAINLY IN
THE LOWER 20S.
SUNDAY...SFC LOW WILL MOVE OUT OF THE GULF ON SUN AND UP THE
ATLANTIC SEABOARD...WHILE THE UPPER RIDGE CONTINUES TO AMPLIFY OVER
THE WRN CONUS AND CANADIAN ROCKIES. THIS WILL KEEP HIGH PRESSURE
OVER THE UPPER GREAT LKS REGION...ALTHOUGH IT WILL GRADUALLY WEAKEN
AS IT FOCUSES OVER WRN LK SUPERIOR. NAM/GFS/ECMWF SHOWING WEAK
SHORTWAVE AND PV LOBE MOVING ACROSS THE AREA DURING THE
MORNING...BUT DRY LOW LEVELS WILL LIMIT PCPN CHANCES OVER THE W.
MODELS CONSISTENT ON H850-500 MOISTURE TO BE STUCK OVER THE WRN
THIRD OF THE CWA TOMORROW...WHICH WITH LIGHT WINDS AT THAT
LEVEL...WENT WITH PARTLY-MOSTLY CLOUDY SKIES. ELSEWHERE...LLVLS ARE
STILL FAIRLY DRY WITH THE HIGH PRESSURE RIDGE...SO EXPECT A MOSTLY
SUNNY SKY. WITH THE SUN OVER THE CNTRL/EAST...EXPECT MIXING TO H800
AND HAVE BUMPED TEMPS UP A DEGREE OR TWO FROM THE GOING
FORECAST...WITH LOW 50S AWAY FROM LK SUPERIOR INFLUENCES. THE LIGHT
NRLY FLOW SHOULD ALLOW THE LK SUPERIOR BREEZE TO DOMINATE AND BRING
SLIGHTLY COOLER TEMPS NEAR LK SUPERIOR THROUGH THE AFTN.
SURPRISINGLY...MODELS NOT PICKING UP ON MUCH COOL DOWN UNTIL AFTER
21Z...SO WILL FOLLOW THAT TREND NEAR LK SUPERIOR FOR NOW.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 425 PM EDT SAT APR 21 2012
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT ON THE BIG PICTURE FOR
THE NEXT 7 DAYS AS PATTERN WILL FEATURE A WRN NAMERICA RIDGE AND
ERN TROF...RESULTING IN NW FLOW DOMINATING THE UPPER GREAT LAKES
REGION. ERN TROF WILL BE MOST AMPLIFIED MON/TUE...AND WRN RIDGE WILL
BEGIN TO DRIFT E DURING THE LAST HALF OF THE WEEK WITH AXIS REACHING
THE MISSISSIPPI VALLEY TO MANITOBA BY SAT. OVERALL...THIS IS A DRY
PATTERN FOR THE FCST AREA. PCPN CHANCES WILL BE LIMITED...AND IF
ANY PCPN OCCURS...IT WILL LIKELY BE LIGHT. NW FLOW SHOULD KEEP TEMPS
ON THE COOLER SIDE OF NORMAL AND PROBABLY TREND MORE BLO NORMAL
LATER IN THE WEEK AS ENERGY DROPPING INTO ERN TROF USHERS COLDER AIR
INTO THE UPPER LAKES. AFTN TEMPS NEAR LAKE SUPERIOR WILL BE CHILLY
WITH ONSHORE WINDS EVERY DAY.
BEGINNING SUN NIGHT THRU TUE...WITHIN THE DEEP ERN TROF...A
MID/UPPER LEVEL LOW WILL BE LIFTING N THRU THE CNTRL APPALACHIANS...
REACHING WRN NY EARLY TUE AND SW QUEBEC TUE EVENING. MEDIUM RANGE
GUIDANCE CONTINUES TO KEEP THIS SYSTEM FAR ENOUGH E SO THAT ITS
DEFORMATION PCPN SHIELD WILL NOT AFFECT THE FCST AREA. THREAT OF ANY
PCPN WOULD COME FROM SHORTWAVES DROPPING THRU THE AREA UNDER NW FLOW
AS THERMAL GRADIENT WILL BE TIGHTENING TOWARD THE UPPER LAKES MON
AND ESPECIALLY TUE. THE GFS/GLOBAL GEM ARE A LITTLE FARTHER E WITH
THE TIGHTER THERMAL GRADIENT THAN THE ECMWF. AS A RESULT...
GFS/GLOBAL GEM HAVE PCPN STREAKING ACROSS MAINLY WRN UPPER MI TUE.
AT THIS POINT...WILL CARRY DRY WEATHER SUN NIGHT THRU MON NIGHT THEN
MAINTAIN SLIGHT CHC POPS LATER TUE/TUE NIGHT OVER ALL BUT THE E.
TIMING/TRACKS OF SHORTWAVES DROPPING INTO THE ERN TROF REMAIN
UNCERTAIN MIDWEEK. THE LAST SEVERAL RUNS OF THE ECMWF HAD BEEN
INSISTENT ON DROPPING A STRONG SHORTWAVE INTO THE UPPER LAKES LATE
THU...BUT THE 12Z RUN IS BEGINNING TO TREND TOWARD THE FASTER
GFS/GLOBAL GEM IDEA. WHETHER THIS WAVE CAN LINK UP/DRAW TIGHT
THERMAL GRADIENT FARTHER NE LIKE THE GFS/GLOBAL GEM TO RESULT IN A
PERIOD OF PCPN ACROSS THE FCST AREA INTO WED REMAINS TO BE SEEN.
BEHIND THE WAVE...850MB TEMPS COULD FALL TO AROUND -10C THU/EARLY
FRI. MIGHT BE ENOUGH FOR A LITTLE LIGHT LES AT NIGHT/EARLY MORNING
IF AIRMASS IS NOT TOO DRY.
FRI INTO SAT...WITH MID/UPPER LEVEL RIDGE MOVING CLOSER TO THE UPPER
LAKES...ASSOCIATED SFC HIGH PRES WILL DOMINATE THE AREA. THIS WILL
KEEP DRY WEATHER INTO THE FIRST HALF OF THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EDT SUN APR 22 2012
VFR CONDITIONS EXPECTED FOR THE TAF SITES THROUGH THE PERIOD...AS A
HIGH IN ONTARIO PUSHES DRY LOW LEVEL AIR INTO UPPER MICHIGAN.
MOISTURE FROM LOW CURRENTLY CENTERED OVER NW MN WILL BRUSH KIWD AND
POTENTIALLY KCMX THROUGH SUN...AS IT WEAKENS AND SLIDES SE THROUGH
SOUTHERN MN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 425 PM EDT SAT APR 21 2012
HIGH PRESSURE NEAR HUDSON BAY WILL KEEP LIGHT NORTHERLY WINDS OVER
MUCH OF LAKE SUPERIOR. A LOW PRESSURE SYSTEM OVER ERN ND IS EXPECTED
TO WEAKEN WHILE QUICKLY SLIDING SE TONIGHT. THIS WILL DIMINISH THE
NE WINDS OF 20-25KTS OVER FAR WRN LAKE SUPERIOR. EXPECT NORTHERLY
WINDS TO REMAIN BELOW 25KTS THROUGH THE FIRST PART OF NEXT WEEK...AS
A LOW PRESSURE SYSTEM MOVES UP THE ATLANTIC SEABOARD TOMORROW AND
INTO QUEBEC BY TUESDAY. COLDER AIR FILTERING INTO THE AREA TOWARDS
MID WEEK COULD LEAD TO SOME STRONGER NORTHERLY WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...07
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
338 AM CDT SUN APR 22 2012
.SHORT TERM...
TEMPERATURES THROUGHOUT THE PERIOD AND WHAT HAPPENS WITH THE
SYSTEM COMING OUT ON TUESDAY WILL BE THE PRIMARY FORECAST PROBLEMS
FOR THE SHORT TERM.
CONDITIONS WILL BE MUCH MORE QUIET TODAY AND TOMORROW AS
NORTHWESTERLY FLOW ALOFT SETS UP BEHIND THE DEPARTING UPPER LOW
AND AHEAD OF THE RIDGE BUILDING OVER THE ROCKIES. SFC HIGH
PRESSURE WILL STRETCH FROM ONTARIO INTO THE PLAINS TODAY. 850MB
TEMPS IN THE EASTERN CWA WILL STILL BE FAIRLY COOL AND THERE WILL
NOT BE A HUGE AMOUNT OF MIXING UNDER THE LIGHT WINDS. ON THE OTHER
HAND...THERE SHOULD BE A FAIR AMOUNT OF SUNSHINE AND SOME WESTERLY
WINDS START MOVING SOME WARMER AIR INTO THE FAR WESTERN CWA THIS
AFTERNOON. DESPITE THE FAIRLY COLD START AROUND FREEZING...THINK
WE SHOULD STILL SEE ENOUGH WARMING TODAY TO GET INTO THE
50S...WITH SOME 60S POSSIBLE IN THE NORTHWEST.
SFC HIGH PRESSURE WILL MOVE SLOWLY OFF TO THE SOUTHEAST
TONIGHT...WITH THE DEVELOPING LOW OVER SASKATCHEWAN SHIFTING WINDS
BACK TO THE SOUTHWEST BY TOMORROW MORNING. LOWS WILL BE A BIT MORE
MILD OVER ALL BUT THE FAR EASTERN COUNTIES WHICH WILL BE HANGING
ONTO LIGHT WINDS A BIT LONGER. THE WARM AIR ADVECTION WILL
CONTINUE INTO MONDAY...WITH WINDS CONTINUING TO PICK UP OUT OF THE
SOUTH TO SOUTHWEST. WITH THE SOUTHWESTERLY WINDS GIVING US SOME
GOOD MIXING AND 850MB TEMPS GETTING BACK INTO THE TEENS C...ALONG
WITH PLENTY OF SUN THINK THAT MOST LOCATIONS WILL SEE THE 60S ON
MONDAY WITH A FEW SPOTS IN THE WEST REACHING THE 70S.
UPPER HEIGHTS WILL START TO COME DOWN A BIT MONDAY NIGHT AND SFC
LOW PRESSURE STARTS TO MOVE INTO THE NORTHERN PLAINS. THE MODELS
HAVE BEEN REALLY STRUGGLING WITH HOW THEY HANDLE THE POSITION OF
THE SFC LOW INTO TUESDAY. THE NAM AND GFS ARE PRETTY FAR NORTH
WITH THE SYSTEM AND HAVE MUCH OF THE CWA IN THE WARM SECTOR OF THE
SFC LOW. THE ECMWF ON THE OTHER HAND...IS FURTHER SOUTH WITH THE
POSITION OF THE LOW AND HAS MUCH OF THE CWA ON THE COOLER EASTERLY
FLOW. CONFIDENCE IS NOT VERY HIGH...SO KEPT POPS IN THE 20-30
PERCENT RANGE WE HAD GOING FOR TUESDAY AND TUESDAY NIGHT. HIGHS IN
THE SOUTHWESTERN COUNTIES COULD GET UP TO OR EVEN ABOVE 80 IF THE
FURTHER NORTH DOMESTIC MODELS VERIFY...WITH THE ECMWF OF COURSE
MUCH COOLER. INCREASED TUESDAY HIGH TEMPS A BIT IN THE WESTERN
COUNTIES...ALTHOUGH DUE TO THE UNCERTAINTY WITH THE POSITION OF
THE LOW DID NOT GET QUITE AS WARM AS THE GFS AND THE NAM.
.LONG TERM...
MODELS HAVE BEEN TRENDING WITH MORE DRIER EASTERLY WINDS FOR
FRIDAY NIGHT...SO LOWERED ALLBLEND POPS IN THE EASTERN COUNTIES.
OTHERWISE NO MAJOR CHANGES. TEMPS WILL COOL BACK TOWARDS SEASONAL
AVERAGES OR SLIGHTLY BELOW.
&&
.AVIATION...
IFR CEILINGS HAVE BEEN HANGING AROUND KBJI AND MOVING BACK INTO
THE KTVF AREA DURING THE LAST FEW HOURS...AND THE HRRR SHOWS SIGNS
THAT THIS WILL CONTINUE. KFAR AT THE EDGE OF THE STRATUS DECK HAS
STAYED MVFR. WILL KEEP THE MVFR/IFR CONDITIONS GOING IN THE
EASTERN TAF SITES THROUGH THE NEXT FEW HOURS...THEN CONDITIONS
SHOULD IMPROVE TO VFR BY MORNING. THE WESTERN TAF SITES WILL STAY
MOSTLY CLEAR...ALTHOUGH WILL HAVE TO WATCH FOR PATCHY FOG
FORMATION. WINDS WILL REMAIN LIGHT FOR MUCH OF THE
DAY...INCREASING OUT OF THE WEST AT AROUND 8 KTS BY AFTERNOON FOR
KDVL.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
JR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
531 AM EDT SUN APR 22 2012
.SYNOPSIS...
POTENT UPPER LOW SWINGS ACROSS THE AREA THROUGH TONIGHT. DEVELOPING
LOW PRESSURE SYSTEM MOVES NORTH ALONG THE MID ATLANTIC COAST THROUGH
MONDAY. A CLIPPER LIKE SYSTEM AFFECT THE AREA BY MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN FORECAST CONCERN OBVIOUSLY WILL BE THE SYSTEM TAKING SHAPE OVER
THE MID-ATLANTIC REGION OVER THE COURSE OF THE NEXT COUPLE OF DAYS
WITH SUBSEQUENT RAIN/SNOW CHANCES FOR THE FORECAST AREA.
NORTHERN STREAM UPPER TROUGH PROGGED TO CLOSE OFF AT H5 BY 18Z
AROUND THE KY/IN/OH AREA. NAM IS COMING INTO BETTER AGREEMENT WITH
THE DEEPER GFS SOLUTION. MEANWHILE THE SOUTHERN STREAM TROUGH
CONTINUES TO FILL AS IT GETS ABSORBED BY STRENGTHENING UPPER LOW OVER
OHIO RIVER VALLEY. SFC LOW MOVING UP THE COAST IN RESPONSE TO
DEVELOPMENT TO ITS WEST WILL BE LOCATED ROUGHLY OVER THE NORTH
CAROLINA COAST BY 18Z...WITH BOTH NAM AND GFS DEPICTING DEEPER LOW
PRESSURE VERSUS PREVIOUS RUNS. VAD PROFILER AT CRW SHOWING DRYING
ABOVE 4KFT OR ABOUT 850MB WHICH RUC SOUNDING SEEMS TO HAVE A DECENT
HANDLE ON. REALLY DON/T BELIEVE THERE WILL BE ANY ONGOING PRECIP
AROUND THE INTERSTATE 79 CORRIDOR AT 15Z BUT CAN/T COMPLETELY RULE
IT OUT SO WILL KEEP SLIGHT CHANCE POPS HERE AT THIS TIME WITH LOW
CHANCE POPS FURTHER SOUTH/EAST ALONG HIGHER TERRAIN...WITH LOW
CHANCE POPS ALONG THE I79 CORRIDOR BY 18Z AS BETTER LLVL MOISTURE
AND WAA WITH GOOD LARGE SCALE FORCING FOR ASCENT BEGIN TO ARRIVE.
LARGE SCALE ASCENT CONTINUES TO INCREASE DURING THE AFTERNOON HOURS
AS H5 UPPER LOW MOVES SE-WARD TOWARDS THE SW PART OF OUR FCST AREA.
990MB ATTENDANT SFC LOW WILL BE LOCATED AROUND THE SOUTHERN DELMARVA
PENINSULA AREA BY 00Z MON. SFC WINDS IN RESPONSE WILL BEGIN TO
SHIFT TO MORE OF A NNW TRAJECTORY WHICH BEGINS TO ENHANCE UPSLOPE
FLOW AGAINST HIGHER TERRAIN. IN ADDITION...GOOD ISENTROPIC LIFT
PARTICULARLY I79 CORRIDOR AND POINTS EAST ON 290K-295K SURFACES WITH
ABUNDANT LLVL MOISTURE UP TO ROUGHLY 500MB WILL ALL MEAN GOOD
CHANCES FOR PRECIP BY 21Z-00Z EASTERN HALF OF FORECAST AREA. ALSO
UNDERCUT LATEST GUIDANCE AND DECREASED MAX TEMPS TODAY BY SEVERAL
DEGREES. WITH ABUNDANT CLOUD COVER...PRECIP RAMPING UP IN THE
AFTERNOON...AND MORNING TEMPS IN THE LOW 40S ACROSS THE
AREA...THINKING THAT TEMPS MAY STRUGGLE TO GET ABOVE 50 AT MOST
LOWLAND LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
COLDER THAN NORMAL TEMPERATURES UNDER NORTHERLY FLOW WILL BRING
FREEZING TEMPERATURES ACROSS THE MOUNTAINS...AND JUST ABOVE
FREEZING LOWLANDS TONIGHT.
A DEVELOPING SFC LOW PRESSURE SYSTEM WILL MOVE NORTH ALONG THE MID
ATLANTIC THROUGH TONIGHT...TO TRANSPORT JUICY GULF STREAM
MOISTURE WEST INTO THE APPALACHIANS. THIS MOISTURE WILL WRAP AROUND
THE MID LATITUDE CYCLONE AS A TROWAL FEATURE EVIDENT IN THE
EQUIVALENT POTENTIAL TEMPERATURE TRAJECTORY FROM THE LOW TO MID
LEVELS INTO THE PORTIONS OF WV TONIGHT AND MONDAY.
AT THE SAME TIME...A POTENT UPPER LEVEL LOW WILL SWING EAST ACROSS
THE OH VALLEY AND WV TONIGHT...AND THEN NORTH INTO THE NORTHEAST
STATES LATE MONDAY. THIS SECOND FEATURE WILL BRING STRONG FORCING
AS SEEN ON H3 TO H4 Q-VECTOR CONVERGENCE. SOME MODELS SUGGEST AXIS
OF 2-D FRONTOGENETICAL FORCING AT H6 TO H7 LAYER.
THESE TWO SYSTEM WILL INTERACT TO PRODUCE COLD TEMPERATURES AND
ASSOCIATED SNOW ACCUMULATIONS MAINLY OVER THE NORTHEAST MOUNTAINS
STARTING TONIGHT...AND CONTINUING INTO EARLY TUESDAY.
FLOW BECOMES NORTHWEST MONDAY...IDEAL FOR UPSLOPE SNOW TO BE
ADDED TO THE SYNOPTIC SNOWS. THEREFORE...INCREASE POPS AND SNOW
AMOUNTS ACROSS THE HIGHER ELEVATIONS...RANGING FROM 5 INCHES LOWER
VALLEYS TO AROUND 10 INCHES AT HIGHEST PEAKS. WARM SOIL
TEMPERATURES WILL PROBABLY MELT THE FIRST SNOWS UPON CONTACT...BUT
EVENTUALLY HEAVY WET SNOW WILL START STICKING ON SURFACES AND
VEGETATION... ESPECIALLY OVER TREE BRANCHES...CAUSING TREE DAMAGES
AND POSSIBLY AFFECTING NEARBY POWER LINES. THEREFORE...A WINTER
STORM WATCH CONTINUES IN EFFECT THROUGH MONDAY MORNING FOR
POCAHONTAS AND RANDOLPH COUNTIES...MAINLY FOR HIGH IMPACT EVENT
FOR SCHOOLS...COMMUTE...AND POWER LINES FLUCTUATIONS OR
INTERRUPTIONS.
IN ADDITION...STRONG GUSTY WINDS COULD EXCEED 40 KNOTS EVIDENT UNDER
280-290K ISENTROPIC CHARTS ON MONDAY. A WIND ADVISORY MAY BE
REQUIRED.
THE UPPER LOW EXITS MONDAY NIGH...BUT THE STRONG NORTHWEST FLOW
COULD KEEP UPSLOPE SNOW FALLING OVER OUR EASTERN MOUNTAINS THROUGH
EARLY TUESDAY. THEREFORE...DELAYED THE ENDING OF POPS OVER THESE
AREAS...WHERE MODELS STILL SHOW DENDRITE GROWTH ZONE AND OMEGA
CROSS HAIL SIGNATURE THROUGH THIS TIME FRAME.
LOWER LOW TEMPS TONIGHT PER STRONGER H850 FLOW...ALTHOUGH MODELS
SHOW CONSISTENCY ON MINUS 4C AT THIS LEVEL FROM PREVIOUS RUNS. AS
THE AFOREMENTIONED SYNOPTIC SYSTEMS LIFT NORTH AWAY FROM THE
AREA...MODELS SUGGEST A 2 DEGREE WARM ADVECTION AT H850. WITH THE
EXPECTED SNOW COVER AND HIGH ELEVATIONS EFFECTS...CODED A SFC
TEMPERATURE GRADIENT RANGING FROM THE LOWER 50S PORTIONS OF SE OH
AND NORTHEAST KY...TO THE LOWER 30S NORTHEAST HIGHEST PEAKS.
ACCUMULATION COULD GREATLY CHANGE DEPENDING ON THE SURFACE LOW
TRACK...WITH HIGHER AMOUNTS POSSIBLE IF THE LOW TRACKS FARTHER
WEST.
WESTERLY FLOW WILL BRING WARM ADVECTION AT H850 TO KEEP ANY PCPN AS
LIQUID FROM OTHER DISTURBANCES APPROACHING ON TUESDAY. MINOR
TEMPERATURE CHANGES NOTED THROUGH THIS TIME PERIODS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
WARM ADVECTION PRECIPITATION AHEAD OF CLIPPER SYSTEM RACES INTO THE
AREA TUE NT. SURFACE LOW CENTER DOES NOT CROSS UNTIL WED NT...AND
IT WILL TAKE UNTIL LATE THU OR THU NT FOR THE PRECIPITATION TO EXIT
THE AREA TO THE SE. MODELS ARE IN BETTER AGREEMENT WITH THE
SCENARIO ALTHOUGH ECMWF CONTINUES TO SHOW A MORE SRN TRACK THAN THE
GFS WITH DEEPER LONG WAVE TROF ALONG E COAST. HPC SOLN IS CLOSEST
TO MORE NORTHERN SOLN AND SO ARE THE GRIDS.
BLENDED IN HPC FOR THE MOST PART FOR TEMPERATURES ALTHOUGH TRENDED
MORE TOWARD A BLEND ALL LATE IN THE PERIOD. HAVE SLIGHTLY HIGHER
LOWS IN THE WARM ADVECTION AHEAD OF THE CLIPPER TUE NT...AND THEN
HAVE TEMPERATURES A BIT LOWER IN THE PRECIPITATION ASSOCIATED WITH
THE CLIPPER AS WELL AS IN THE COOLER AIR BEHIND IT.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
06Z SUNDAY THROUGH 06Z MONDAY... SOLID VLIFR-IFR FLIGHT CONDITIONS
WILL PREVAIL OVERNIGHT...WITH INTERMITTENT MVFR CIGS. IMPROVEMENT
TO MVFR OR LOW VFR AFTER 15Z SUNDAY ACROSS MUCH OF THE LOWLANDS...WITH
MVFR/IFR CONTINUING TO LINGER ACROSS THE HIGHER TERRAIN. A RETURN
TO IFR CONDITIONS CAN BE EXPECTED BY 06Z MONDAY WITH PERHAPS LOW
MVFR CIGS HANGING ON AT WESTERN SITES SUCH AS HTS AND PKB.
A STRONG LOW PRESSURE SYSTEM WILL MOVE NORTH ALONG THE COAST ON
SUNDAY. THIS WILL SPREAD PRECIPITATION BACK INTO THE AREA...PARTICULARLY
ACROSS NORTHERN/CENTRAL WV AFTER 18-21Z. PRECIPITATION IS EXPECTED
TO REMAIN IN THE FORM OF RAIN BEFORE 21Z SUN...BUT WILL BEGIN TO
TRANSITION TO SNOW ACROSS THE NORTHERN MOUNTAINS INCLUDING EKN
BTWN 21Z-00Z...WITH SNOW EXPECTED AT EKN BY 00Z MON AND
DRASTICALLY REDUCING VIS AT THIS POINT. IN ADDITION...GUSTY NORTH TO
NORTHEAST WINDS WILL DEVELOP AFTER 15Z SUNDAY...WITH GUSTS OF UP
TO 22KTS ACROSS THE LOWLANDS...AND UP TO 30 KTS ACROSS THE HIGHER
TERRAIN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: IMPROVEMENT IN CEILINGS MAY VARY BY A COUPLE
OF HOURS ON SUNDAY. EXPECTED IFR CEILINGS 00Z-15Z WILL LINGER
NEAR THRESHOLD OF MVFR LEAVING SMALL MARGIN FOR ERROR.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SUN 04/22/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY M M M M M M M M L H H H
HTS CONSISTENCY H H H M M M M L L H H H
BKW CONSISTENCY M M M M M M L L M L L L
EKN CONSISTENCY L M M M M M M M L L L L
PKB CONSISTENCY M M M M M H L M L L L L
CKB CONSISTENCY M M H H H M L H L H H H
AFTER 12Z MONDAY...
IFR EXPECTED IN MOUNTAIN SNOW SUNDAY NIGHT THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WATCH FROM LATE TONIGHT THROUGH MONDAY EVENING
FOR WVZ046-047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...50
SHORT TERM...ARJ
LONG TERM...TRM
AVIATION...50
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
457 AM EDT SUN APR 22 2012
.SYNOPSIS...
POTENT UPPER LOW SWINGS ACROSS THE AREA THROUGH TONIGHT. DEVELOPING
LOW PRESSURE SYSTEM MOVES NORTH ALONG THE MID ATLANTIC COAST THROUGH
MONDAY. A CLIPPER LIKE SYSTEM AFFECT THE AREA BY MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN FORECAST CONCERN OBVIOUSLY WILL BE THE SYSTEM TAKING SHAPE OVER
THE MID-ATLANTIC REGION OVER THE COURSE OF THE NEXT COUPLE OF DAYS
WITH SUBSEQUENT RAIN/SNOW CHANCES FOR THE FORECAST AREA.
NORTHERN STREAM UPPER TROUGH PROGGED TO CLOSE OFF AT H5 BY 18Z
AROUND THE KY/IN/OH AREA. NAM IS COMING INTO BETTER AGREEMENT WITH
THE DEEPER GFS SOLUTION. MEANWHILE THE SOUTHERN STREAM TROUGH
CONTINUES TO FILL AS IT GETS ABSORBED BY STRENGTHENING UPPER LOW OVER
OHIO RIVER VALLEY. SFC LOW MOVING UP THE COAST IN RESPONSE TO
DEVELOPMENT TO ITS WEST WILL BE LOCATED ROUGHLY OVER THE NORTH
CAROLINA COAST BY 18Z...WITH BOTH NAM AND GFS DEPICTING DEEPER LOW
PRESSURE VERSUS PREVIOUS RUNS. VAD PROFILER AT CRW SHOWING DRYING
ABOVE 4KFT OR ABOUT 850MB WHICH RUC SOUNDING SEEMS TO HAVE A DECENT
HANDLE ON. REALLY DON/T BELIEVE THERE WILL BE ANY ONGOING PRECIP
AROUND THE INTERSTATE 79 CORRIDOR AT 15Z BUT CAN/T COMPLETELY RULE
IT OUT SO WILL KEEP SLIGHT CHANCE POPS HERE AT THIS TIME WITH LOW
CHANCE POPS FURTHER SOUTH/EAST ALONG HIGHER TERRAIN...WITH LOW
CHANCE POPS ALONG THE I79 CORRIDOR BY 18Z AS BETTER LLVL MOISTURE
AND WAA WITH GOOD LARGE SCALE FORCING FOR ASCENT BEGIN TO ARRIVE.
LARGE SCALE ASCENT CONTINUES TO INCREASE DURING THE AFTERNOON HOURS
AS H5 UPPER LOW MOVES SE-WARD TOWARDS THE SW PART OF OUR FCST AREA.
990MB ATTENDANT SFC LOW WILL BE LOCATED AROUND THE SOUTHERN DELMARVA
PENINSULA AREA BY 00Z MON. SFC WINDS IN RESPONSE WILL BEGIN TO
SHIFT TO MORE OF A NNW TRAJECTORY WHICH BEGINS TO ENHANCE UPSLOPE
FLOW AGAINST HIGHER TERRAIN. IN ADDITION...GOOD ISENTROPIC LIFT
PARTICULARLY I79 CORRIDOR AND POINTS EAST ON 290K-295K SURFACES WITH
ABUNDANT LLVL MOISTURE UP TO ROUGHLY 500MB WILL ALL MEAN GOOD
CHANCES FOR PRECIP BY 21Z-00Z EASTERN HALF OF FORECAST AREA. ALSO
UNDERCUT LATEST GUIDANCE AND DECREASED MAX TEMPS TODAY BY SEVERAL
DEGREES. WITH ABUNDANT CLOUD COVER...PRECIP RAMPING UP IN THE
AFTERNOON...AND MORNING TEMPS IN THE LOW 40S ACROSS THE
AREA...THINKING THAT TEMPS MAY STRUGGLE TO GET ABOVE 50 AT MOST
LOWLAND LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
COLDER THAN NORMAL TEMPERATURES UNDER NORTHERLY FLOW WILL BRING
FREEZING TEMPERATURES ACROSS THE MOUNTAINS...AND JUST ABOVE
FREEZING LOWLANDS TONIGHT.
A DEVELOPING SFC LOW PRESSURE SYSTEM WILL MOVE NORTH ALONG THE MID
ATLANTIC THROUGH TONIGHT...TO TRANSPORT JUICY GULF STREAM
MOISTURE WEST INTO THE APPALACHIANS. THIS MOISTURE WILL WRAP AROUND
THE MID LATITUDE CYCLONE AS A TROWAL FEATURE EVIDENT IN THE
EQUIVALENT POTENTIAL TEMPERATURE TRAJECTORY FROM THE LOW TO MID
LEVELS INTO THE PORTIONS OF WV TONIGHT AND MONDAY.
AT THE SAME TIME...A POTENT UPPER LEVEL LOW WILL SWING EAST ACROSS
THE OH VALLEY AND WV TONIGHT...AND THEN NORTH INTO THE NORTHEAST
STATES LATE MONDAY. THIS SECOND FEATURE WILL BRING STRONG FORCING
AS SEEN ON H3 TO H4 Q-VECTOR CONVERGENCE. SOME MODELS SUGGEST AXIS
OF 2-D FRONTOGENETICAL FORCING AT H6 TO H7 LAYER.
THESE TWO SYSTEM WILL INTERACT TO PRODUCE COLD TEMPERATURES AND
ASSOCIATED SNOW ACCUMULATIONS MAINLY OVER THE NORTHEAST MOUNTAINS
STARTING TONIGHT...AND CONTINUING INTO EARLY TUESDAY.
FLOW BECOMES NORTHWEST MONDAY...IDEAL FOR UPSLOPE SNOW TO BE
ADDED TO THE SYNOPTIC SNOWS. THEREFORE...INCREASE POPS AND SNOW
AMOUNTS ACROSS THE HIGHER ELEVATIONS...RANGING FROM 5 INCHES LOWER
VALLEYS TO AROUND 10 INCHES AT HIGHEST PEAKS. WARM SOIL
TEMPERATURES WILL PROBABLY MELT THE FIRST SNOWS UPON CONTACT...BUT
EVENTUALLY HEAVY WET SNOW WILL START STICKING ON SURFACES AND
VEGETATION... ESPECIALLY OVER TREE BRANCHES...CAUSING TREE DAMAGES
AND POSSIBLY AFFECTING NEARBY POWER LINES. THEREFORE...A WINTER
STORM WATCH CONTINUES IN EFFECT THROUGH MONDAY MORNING FOR
POCAHONTAS AND RANDOLPH COUNTIES...MAINLY FOR HIGH IMPACT EVENT
FOR SCHOOLS...COMMUTE...AND POWER LINES FLUCTUATIONS OR
INTERRUPTIONS.
THE UPPER LOW EXITS MONDAY NIGH...BUT THE STRONG NORTHWEST FLOW
COULD KEEP UPSLOPE SNOW FALLING OVER OUR EASTERN MOUNTAINS THROUGH
EARLY TUESDAY. THEREFORE...DELAYED THE ENDING OF POPS OVER THESE
AREAS...WHERE MODELS STILL SHOW DENDRITE GROWTH ZONE AND OMEGA
CROSS HAIL SIGNATURE THROUGH THIS TIME FRAME.
LOWER LOW TEMPS TONIGHT PER STRONGER H850 FLOW...ALTHOUGH MODELS
SHOW CONSISTENCY ON MINUS 4C AT THIS LEVEL FROM PREVIOUS RUNS. AS
THE AFOREMENTIONED SYNOPTIC SYSTEMS LIFT NORTH AWAY FROM THE
AREA...MODELS SUGGEST A 2 DEGREE WARM ADVECTION AT H850. WITH THE
EXPECTED SNOW COVER AND HIGH ELEVATIONS EFFECTS...CODED A SFC
TEMPERATURE GRADIENT RANGING FROM THE LOWER 50S PORTIONS OF SE OH
AND NORTHEAST KY...TO THE LOWER 30S NORTHEAST HIGHEST PEAKS.
ACCUMULATION COULD GREATLY CHANGE DEPENDING ON THE SURFACE LOW
TRACK...WITH HIGHER AMOUNTS POSSIBLE IF THE LOW TRACKS FARTHER
WEST.
WESTERLY FLOW WILL BRING WARM ADVECTION AT H850 TO KEEP ANY PCPN AS
LIQUID FROM OTHER DISTURBANCES APPROACHING ON TUESDAY NIGHT
THROUGH WEDNESDAY. MINOR TEMPERATURE CHANGES NOTED THROUGH THIS
TIME PERIODS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
WARM ADVECTION PRECIPITATION AHEAD OF CLIPPER SYSTEM RACES INTO THE
AREA TUE NT. SURFACE LOW CENTER DOES NOT CROSS UNTIL WED NT...AND
IT WILL TAKE UNTIL LATE THU OR THU NT FOR THE PRECIPITATION TO EXIT
THE AREA TO THE SE. MODELS ARE IN BETTER AGREEMENT WITH THE
SCENARIO ALTHOUGH ECMWF CONTINUES TO SHOW A MORE SRN TRACK THAN THE
GFS WITH DEEPER LONG WAVE TROF ALONG E COAST. HPC SOLN IS CLOSEST
TO MORE NORTHERN SOLN AND SO ARE THE GRIDS.
BLENDED IN HPC FOR THE MOST PART FOR TEMPERATURES ALTHOUGH TRENDED
MORE TOWARD A BLEND ALL LATE IN THE PERIOD. HAVE SLIGHTLY HIGHER
LOWS IN THE WARM ADVECTION AHEAD OF THE CLIPPER TUE NT...AND THEN
HAVE TEMPERATURES A BIT LOWER IN THE PRECIPITATION ASSOCIATED WITH
THE CLIPPER AS WELL AS IN THE COOLER AIR BEHIND IT.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
06Z SUNDAY THROUGH 06Z MONDAY... SOLID VLIFR-IFR FLIGHT CONDITIONS
WILL PREVAIL OVERNIGHT...WITH INTERMITTENT MVFR CIGS. IMPROVEMENT
TO MVFR OR LOW VFR AFTER 15Z SUNDAY ACROSS MUCH OF THE LOWLANDS...WITH
MVFR/IFR CONTINUING TO LINGER ACROSS THE HIGHER TERRAIN. A RETURN
TO IFR CONDITIONS CAN BE EXPECTED BY 06Z MONDAY WITH PERHAPS LOW
MVFR CIGS HANGING ON AT WESTERN SITES SUCH AS HTS AND PKB.
A STRONG LOW PRESSURE SYSTEM WILL MOVE NORTH ALONG THE COAST ON
SUNDAY. THIS WILL SPREAD PRECIPITATION BACK INTO THE AREA...PARTICULARLY
ACROSS NORTHERN/CENTRAL WV AFTER 18-21Z. PRECIPITATION IS EXPECTED
TO REMAIN IN THE FORM OF RAIN BEFORE 21Z SUN...BUT WILL BEGIN TO
TRANSITION TO SNOW ACROSS THE NORTHERN MOUNTAINS INCLUDING EKN
BTWN 21Z-00Z...WITH SNOW EXPECTED AT EKN BY 00Z MON AND
DRASTICALLY REDUCING VIS AT THIS POINT. IN ADDITION...GUSTY NORTH TO
NORTHEAST WINDS WILL DEVELOP AFTER 15Z SUNDAY...WITH GUSTS OF UP
TO 22KTS ACROSS THE LOWLANDS...AND UP TO 30 KTS ACROSS THE HIGHER
TERRAIN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: IMPROVEMENT IN CEILINGS MAY VARY BY A COUPLE
OF HOURS ON SUNDAY. EXPECTED IFR CEILINGS 00Z-15Z WILL LINGER
NEAR THRESHOLD OF MVFR LEAVING SMALL MARGIN FOR ERROR.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SUN 04/22/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY M M M M M M M M L H H H
HTS CONSISTENCY H H H M M M M L L H H H
BKW CONSISTENCY M M M M M M L L M L L L
EKN CONSISTENCY L M M M M M M M L L L L
PKB CONSISTENCY M M M M M H L M L L L L
CKB CONSISTENCY M M H H H M L H L H H H
AFTER 06Z MONDAY...
IFR EXPECTED IN MOUNTAIN SNOW SUNDAY NIGHT THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WATCH FROM LATE TONIGHT THROUGH MONDAY EVENING
FOR WVZ046-047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...50
SHORT TERM...ARJ
LONG TERM...TRM
AVIATION...50
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
150 AM EDT SUN APR 22 2012
.SYNOPSIS...
A DEEP AREA OF LOW PRESSURE ALOFT AND AT THE SURFACE WILL MOVE
FROM THE SOUTHEAST U.S. NORTHWARD ALONG THE EAST COAST THROUGH
MONDAY. A VARIETY OF INCLEMENT WEATHER WILL ACCOMPANY THIS SYSTEM
DURING THE NEXT SEVERAL DAYS...CONSISTING OF SHOWERS AND STORMS
ACROSS THE PIEDMONT TONIGHT...THEN WIDESPREAD RAIN SUNDAY.
CONSIDERABLY COLDER AIR WILL WRAP AROUND THE BACK SIDE OF THE
SYSTEM...WITH ACCUMULATING SNOW POSSIBLE BY EARLY MONDAY ACROSS
THE CENTRAL AND NORTHERN APPALACHIANS.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 815 PM EDT SATURDAY...
NOT A LOT OF CHANGE TO THE GOING FORECAST TONIGHT WITH THE SURFACE
COLD FRONT NOW ACROSS THE FAR SE WHERE THE PRE-FRONTAL BAND OF
CONVECTION HAS BASICALLY COME TO A HALT. LATEST HRRR AND LOCAL WRF
TEND TO DEVELOP THIS AXIS OF SHRA/TSRA A LITTLE MORE TO THE SE
THRU MIDNIGHT BEFORE BACKING STARTS OVERRUNNING THE BOUNDARY
OVERNIGHT AS THE GULF LOW STARTS TO WORK NE UP THE COAST BY
MORNING. ALTHO CONVECTION REMAINS RATHER SHALLOW OVER THE
SE...WILL NEED TO WATCH FOR TRAINING OF CELLS PENDING JUST HOW
MUCH THE COVERAGE DECREASES WITH LOSS OF HEATING AS LATEST SPC
MESO ANALYSIS SHOWS BEST CAPE NOW JUST SE OF THE CWA. THUS DID ADD
A COUPLE HOURS OF HVY RAIN MENTION...MAINLY ACROSS SOUTHSIDE VA/NW
NC PIEDMONT INTO LATE THIS EVENING...WITH POPS LOWERING TO LIKELYS
BEFORE RATCHETING BACK UP TO CATEGORICAL AS PRECIP STARTS TO HEAD
BACK TO THE NNW AFTER MIDNIGHT. MAINLY RUNNING WITH CHANCE TO
SLIGHT POPS ELSW WITH A FEW SHRA/ISOLD -TSRA BANDS LEFTOVER ALONG
THE SRN BLUE RIDGE PER A WEAK SURFACE WAVE NEAR CLT IN BETWEEN
THE SFC AND 85H FRONT STILL BACK IN SE WVA. APPEARS STEADIER RAIN
WONT REDEVELOP OUTSIDE OF THE SE UNTIL TOWARD DAYBREAK WHEN DEEPER
EASTERLY FLOW ESTABLISHES WITH THE HEAVIEST CLOSER TO THE RESIDUAL
FRONT AND PERHAPS IN A DEFORMATION ZONE FARTHER WEST ACROSS THE
MOUNTAINS. OTRW GOING LOW TEMPS LOOK ABOUT ON TRACK AS LOW LEVEL
COOL ADVECTION OOZES IN ALLOWING MOST LOCATIONS EXCEPT THE FAR SE
TO FALL INTO THE 40S BY MORNING.
PREVIOUS DISCUSSION AS OF 350 PM EDT SATURDAY...
SCATTERED SHOWERS AND STORMS WILL CONTINUE MOVING EAST THROUGH
THIS AFTERNOON...EVENTUALLY TO BE REPLACED BY A MORE STEADY
STRATIFORM BEHIND THE COLD FRONT WHICH HAS SLOWED DOWN
CONSIDERABLY OVER THE NEW RIVER AND ROANOKE VALLEYS. WINDS MAY
GUST TO 30 MPH WITH ANY THUNDERSTORMS. BEST CHANCE FOR STRONG
STORMS REMAINS IN THE LYH/DAN/SIF CORRIDOR AS THOSE SPOTS GOT
CLOSE TO 80F TODAY BEFORE CLOUDS ARRIVED WITH MID 50S DEWPOINTS.
SOME OF THE CLUSTERS NOW MERGING IN NW NC MAY STRENGTHEN AS THEY
TOUCH THE 1K J/KG CAPE AND 35 M/S 0-6 KM SHEAR WHICH RESIDES EAST
OF THE BLUE RIDGE. BIGGEST THREAT WILL BE GUSTY WINDS...ALTHOUGH
SOME PEA SIZED HAIL WAS REPORTED WITH STORMS OVER HILLSVILLE A FEW
HOURS AGO. INSTABILITY WANES THIS EVENING AS FRONT SLIDES
EAST...WITH A BREAK IN THE PRECIP. BUT STRONG SURFACE LOW WITH
STOUT UPPER WAVE MOVES UP THE COAST SPREADING STRATIFORM RAIN
ACROSS THE ENTIRE CWA BY 12Z/8A SUNDAY. RAIN MAY BE HVY AT TIMES
LYH/DAN AND POINTS EAST WITH POSSIBLY AN INCH OF RAIN DURING THE
DAYTIME HOURS SUNDAY. PUT HVY RAIN IN THE WX GRIDS. ALSO TIGHT
PRESSURE GRADIENT COULD CAUSE LYH TO GUST TO 30 MPH FROM THE NE
MIDDAY. INC POPS ACROSS THE CWA. MORNING TEMPS WILL LIKELY BE
HIGHS FOR THE DAY...SO WENT WITH TEMPS SLOWLY FALLING DURING THE
DAY WITH IMPRESSIVE DEEP N TO NE FLOW AND PRECIP AL DAY. TEMPS
WILL PROBABLY BE IN THE MID TO UPPER 40S TOMORROW AFTERNOON AFTER
MORNING MAX T...ALTHOUGH WARMER MARITIME AIR MAY KEEP SOUTHSIDE IN
THE 50S DURING THE DAY. NW WINDS DEVELOPING LATE AND DOWNSLOPING
COULD ALSO ALLOW NW NC TO GUST TO 30 MPH LATE DAY. AN INCH OR TWO
OF RAIN MAY FALL TOTAL TONIGHT THROUGH SUN NIGHT IN THE PIEDMONT
AND SOUTHSIDE.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 315 PM EDT SATURDAY...
GOING TO SEE A TRANSITION TO COLDER AND WINDY WEATHER THIS PERIOD.
MODELS SHOW ENOUGH AGREEMENT IN TRACK OF THE SFC/UPPER LOW THAT
SUNDAY EVENING SHOWERS WILL BE FALLING ACROSS A GOOD DEAL OF THE
AREA...BUT STARTING TO DRY OUT IN THE SOUTHWEST. AS THE UPPER LOW
DEEPENS OVER WRN VIRGINIA LATE SUNDAY NIGHT...8H TEMPS DROP TO -2 IN
THE MTNS WHERE RAIN SHOWERS WILL CHANGE TO SNOW SHOWERS. ATTM...MADE
SOME UPWARD ADJUSTMENTS ON ACCUMULATION...BUT EXPECT IT TO STAY
BELOW ANY ADVISORY LEVELS...AS THE GROUND WILL BE WARM...AND SPEED
OF SYSTEM MAY LIMIT PERIOD OF STRONG LIFT/COLDER TEMPS STAYING
OVERHEAD. ATTM...WILL SEE AN INCH OR MORE ACROSS THE HIGHER
ELEVATIONS (ABOVE 4000 FEET) LATE SUNDAY NIGHT-MONDAY MORNING. THIS
INCLUDES MOUNT ROGERS...BURKES GARDEN AREA...AND THE HIGHLANDS OF
BATH...WEST INTO GREENBRIER COUNTY. GIVEN AMOUNT OF QPF...WRN
GREENBRIER STANDS THE BEST SHOT OF SEEING SEVERAL INCHES OF WET
SNOW.
THIS SYSTEM SWINGS INLAND SOME MONDAY AND DEEPENS TO A 986 LOW
ACROSS NEW YORK. MODELS SHOW ENOUGH OF A TIGHT GRADIENT AND 8H WINDS
OF 45-50 KNOTS THAT WILL BE BUMPING WIND GUSTS UP TO 30+ KNOTS.
WOULD NOT BE SURPRISED TO SEE A WIND ADVISORY...MAYBE A HIGH WIND
WARNING FOR A PERIOD OF TIME MONDAY....BUT WILL WAIT FOR MORE
CONSISTENCY IN MODELS AND ANOTHER RUN OR TWO BEFORE ISSUING
HEADLINES IF NEEDED.
THE SNOW THREAT/WIND THREAT IS MENTIONED IN THE HAZARDOUS WEATHER
OUTLOOK.
THE SHOWERY CONDITIONS WILL BE STARTING TO WIND DOWN DURING THE AFTN
MONDAY AS MOISTURE STARTS TO BECOME MORE LIMITED. ANOTHER VORT
TAKING A SEWD TURN AROUND THE UPPER LOW MONDAY NIGHT WILL KEEP A FEW
RAIN/SNOW SHOWERS FALLING INTO THE MTNS OF SE WV. TEMPS SLIP INTO
THE UPPER 20S MON NIGHT IN THE MTNS TO THE MID TO UPPER 30S OUT
EAST. WINDS WILL FROST FROM FORMING...BUT DEFINITELY COULD SEE A
FREEZE IN THE MOUNTAINS.
TUESDAY...THERE STILL EXISTS A GRADIENT BETWEEN THE DEPARTING LOW
INTO CANADA AND HIGH PRESSURE IN THE GULF OF MEXICO. ANOTHER
SHORTWAVE MOVES ACROSS TUESDAY AFTN AND COULD SEE WEST WINDS GUSTING
TO 25 - 35 MPH AT TIMES.
AS FOR TEMPS...MADE IT COOLER IN THE MOUNTAINS MONDAY WITH
40S...SOME UPPER 30S HIGHER ELEVATIONS TO 50S EAST PER DOWNSLOPE.
TUESDAY WILL BE MILDER IN THE EAST WITH 60S AND FLOW TURNING MORE
WEST...WHILE THE MOUNTAINS STAY IN THE 50S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 130 PM EDT SATURDAY...
THE ECMWF AND GFS DEPICT A CLIPPER TRACKING SOUTHEASTWARD FROM THE
UPPER MIDWEST TO THE OHIO RIVER VALLEY FOR TUESDAY NIGHT INTO
WEDNESDAY. SOME SHOWERS MAY SPREAD AHEAD OF IT AND REACH THE WESTERN
PART OF THE CWA BY WEDNESDAY MORNING...AND THE PIEDMONT LATER IN
THE DAY. THE CLIPPER WILL PASS OVER THE CWA DURING WEDNESDAY NIGHT
INTO THURSDAY...BUT THE MODELS DIVERGE SIGNIFICANTLY WITH THE
DETAILS. THE ECMWF SHOWS EASTERLY SFC WINDS AND HIGHER QPF FROM
THE CLIPPER...WHILE THE GFS SHOWS WESTERLY SFC WINDS AND LOWER QPF.
IF THE ECMWF VERIFIES...A COLD WEDGE WOULD FORM...AND CAUSE THURSDAY
TEMPERATURES TO BE 10 TO 20 DEGREES COOLER THAN THE GFS. GIVEN THIS
LARGE DISCREPANCY...CHANCE POPS WERE INTRODUCED FOR THURSDAY...AND
TEMPERATURES WERE BUMPED DOWNWARD BUT KEPT IN THE MIDDLE OF BOTH
SOLUTIONS UNTIL BETTER AGREEMENT IS ESTABLISHED IN FUTURE RUNS.
THE CLIPPER SHOULD EXIT THE CWA AND HEAD SOUTHWARD THROUGH THE
CAROLINAS BY FRIDAY. MEANWHILE...HIGH PRESSURE WILL BUILD OVER THE
MID ATLANTIC FROM THE NORTHWEST. THIS SITUATION SHOULD ALLOW
PLEASANT AND SEASONABLE CONDITIONS FOR THE START OF NEXT WEEKEND.
BOTH THE ECMWF AND GFS KEEP THIS AREA OF HIGH PRESSURE NORTH OF THE
CWA AND SLIDE IT OFF THE EAST COAST BY SUNDAY...WHICH WILL PROMPT A
WARMING TREND AND INCREASING DEWPOINTS FROM RETURN SOUTHERLY FLOW.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 150 AM EDT SUNDAY...
FIRST WAVE OF FRONTAL SHRA/TSRA HAS MOVED EAST OUT OF THE CWA...BUT
SHRA AND EVEN AN ISOLD TSRA OR TWO SPREADING BACK NORTHWARD FROM NC
INTO SW/SC VA IN ASSOCIATION WITH DEEPENING/PHASING UPPER LOW AND
DEVELOPING MID-ATLANTIC COASTAL LOW. EXPECT WIDESPREAD -RA TO SPREAD
ACROSS THE CWA FROM S-N THROUGH 12Z...ESPECIALLY ALONG EAST OF THE
WV/VA LINE OR THE ALLEGHANYS. HEAVIEST/STEADIEST RAIN WILL AFFECT
AREAS ALONG-EAST OF THE BLUE RIDGE...INCLUDING DAN/LYH. CIGS NOW
GENERALLY VFR...BUT WITHIN AN HOUR OR TWO OF THE ONSET OF THE
STEADIER RAIN...EXPECT CIGS TO DROP INTO THE MVFR RANGE...THEN TO
IFR BY 12Z...HOLDING THERE THROUGHOUT MUCH OF THE DAY. VSBYS
GENERALLY MVFR 3-5SM -RA BR ONCE THE STEADIER SETS IN BY 08Z AND
BEYOND. EXCEPTION TO THIS PATTERN WILL BE BLF-LWB...ON BACK SIDE OF
ALLEGHANYS WHERE VSBYS EXPECTED TO REMAIN MVFR -RA BR...BUT WITH
CIGS LOWERING/REMAINING MVFR-IFR. WINDS...NW-NNW AT MOST TAF SITES
AT THE CURRENT TIME. PROGRESSION OF COASTAL LOW SHOULD RESULT IN
WINDS GENERALLY VEERING TO NNE-NE EAST OF THE ALLEGHANYS AND WITH
SLOWLY INCREASING SPEEDS THROUGHOUT THE DAY. AS THE LOW REACHES THE
DELMARVA REGION THIS EVENING...WINDS WILL BACK TO NNW-NW AT ALL TAF
SITES. SPEEDS 10-12KTS WITH GUSTS TO 20KTS THROUGH THE EVENING
HOURS. STRONGER NW WINDS ARE EXPECTED MON...WNW-NW 15-25KTS WITH
GUSTS 30-35KTS AFT 12Z MON.
A MIX OF RAIN AND SNOW SHOWERS WILL AFFECT THE KLWB/KBLF CORRIDOR
LATE SUNDAY NIGHT AND INTO MONDAY. SOME 40-45 KT WIND GUSTS ARE NOT
OUT OF THE QUESTION KROA/KBCB WITH STRONG DOWNSLOPING FLOW INTO
MONDAY. CONDS IMPROVE INTO THE MIDDLE OF NEXT WEEK WITH A CHC FOR
RAIN AND A POTENTIAL WEDGE INTO THURSDAY WITH IFR CIGS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KM/RAB
NEAR TERM...JH/KM
SHORT TERM...WP
LONG TERM...PM
AVIATION...KM/JH/RAB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
300 AM CDT SUN APR 22 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
300 AM CDT SUN APR 22 2012
MAIN FORECAST CONCERNS ARE ON THE NEXT PRECIPITATION CHANCES FOR
TUESDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED STRONG RIDGING OVER THE WESTERN U.S. BUILDING INTO SOUTHWEST
CANADA...WHILE TROUGHING WAS PRESENT FROM THE WESTERN GREAT LAKES
REGION SOUTH INTO FLORIDA. MAIN FEATURES OF NOTE TRAVERSING THROUGH
THE TROUGH INCLUDE: AN UPPER LOW NEAR FLORIDA...A POTENT SHORTWAVE
OVER SOUTHWEST IOWA...AND ANOTHER SHORTWAVE IN EASTERN NORTH DAKOTA.
THE POTENT SHORTWAVE HAS BEEN RESPONSIBLE FOR MUCH OF THE
PRECIPITATION AFFECTING THE WESTERN PORTION OF THE FORECAST AREA THE
PAST 18 HOURS...AN IN PARTICULAR A LOW TO MID LEVEL FRONTOGENESIS
ZONE AHEAD OF IT. RUC ANALYSIS SHOWED THIS FRONTOGENESIS HAS DROPPED
SOUTH INTO EASTERN IOWA...AND AS SUCH THE SHOWERS HAVE BEEN
WEAKENING OVER THE FORECAST AREA OVERNIGHT. ANOTHER FEATURE ALLOWING
PRECIPITATION TO WEAKEN IS AN AREA OF HIGH PRESSURE OVER NORTHEAST
ONTARIO. EASTERLY WINDS ARE ADVECTING DRIER AIR OUT OF THE HIGH INTO
THE FORECAST AREA...PARTICULARLY WISCONSIN. 00Z GRB SOUNDING HAD A
PRECIPITABLE WATER OF 0.26 INCHES. THE EASTERLY WINDS STOP AT AN
INVERTED TROUGH WHICH EXTENDS FROM JUST WEST OF MINNEAPOLIS SOUTH
INTO SOUTHEAST IOWA. AIRMASS REMAINS SEASONABLY COOL OVER THE AREA
WITH 850MB TEMPS BETWEEN 0 AND -2C PER 00Z RAOB ANALYSIS.
TODAY THROUGH MONDAY...OVER THE NEXT 24 TO 36 HOURS...A FAIRLY DEEP
TROUGH IS GOING TO FORM OVER THE EASTERN THIRD OF THE U.S....IN
RESPONSE TO THE CURRENT POTENT SHORTWAVE IN IOWA PHASING WITH THE
UPPER LOW IN FLORIDA. IN RESPONSE TO THIS PHASING...A STRONG SPRING
STORM WILL FORM OVER THE NORTHEAST. FOR THE FORECAST AREA...PLAN ON
MAINLY QUIET WEATHER AS HIGH PRESSURE OVER NORTHERN ONTARIO SLOWLY
SINKS SOUTH. THERE ARE STILL SOME ISSUES TO DEAL WITH...THOUGH. THE
FIRST OF WHICH IS THE LINGERING PRECIPITATION AND INVERTED TROUGH.
AS TODAY WEARS ON...THE INVERTED TROUGH SHOULD CONTINUE TO WEAKEN...
ESPECIALLY THIS EVENING WHEN THE SHORTWAVE OVER EASTERN NORTH DAKOTA
SLIDES SOUTH OF THE AREA. ISOLATED/SCATTERED SHOWERS SEEM POSSIBLE
TODAY NEAR THE INVERTED TROUGH...AIDED BY FOCUSED LOW LEVEL
CONVERGENCE AND MOISTURE. MAINTAINED SOME 20 PERCENT CHANCES IN THE
VERY FAR WESTERN PORTION OF THE FORECAST AREA THIS MORNING...IN
AGREEMENT WITH THE 22.00Z NAM/GFS AND LATEST HRRR RUNS. FOR THE REST
OF THE FORECAST AREA TODAY...AN INCREASING NORTHEAST FLOW WILL HELP
BRING IN LOW LEVEL DRY AIR. SOME CLEARING IS POSSIBLE...ESPECIALLY
OVER THE SOUTHEAST END OF THE AREA. TONIGHT...ALTHOUGH THE HIGH
PRESSURE AREA IS MOVING IN...THE NORTHWEST FLOW ALOFT SHOULD HELP
CARRY LOW TO MID LEVEL STRATUS SEEN OVER THE DULUTH AREA SOUTH
ACROSS THE FORECAST AREA. THESE CLOUDS SHOULD BE ENOUGH TO PREVENT
TEMPERATURES FROM REACHING A FROST/FREEZE SITUATION. SKIES ARE
EXPECTED TO CLEAR OUT MONDAY MORNING...THEN ANOTHER SURGE OF MID TO
HIGH CLOUDS ENTER THE PICTURE FROM THE NORTH IN THE AFTERNOON. THIS
IS ASSOCIATED WITH A SMALL PORTION OF THE WESTERN UPPER RIDGE THAT
IS PROGGED TO BUILD TOWARDS THE FORECAST AREA. WE WILL FEEL THIS TOO
BY AN INCREASE IN TEMPERATURES. 850MB TEMPS ARE ONLY 0 TO -2C
TODAY...RESULTING IN HIGHS ONLY IN THE MID 50S. HOWEVER...BY 00Z
TUESDAY...THEY CLIMB TO 2-4C...ALLOWING FOR HIGHS IN THE UPPER 50S
TO LOW 60S.
MONDAY NIGHT THROUGH TUESDAY NIGHT...FOCUS TURNS TO A LOW PRESSURE
SYSTEM PROGGED TO DEVELOP OVER SOUTH CENTRAL SASKATCHEWAN AT 00Z
TUESDAY...ON TOP OF THE UPPER RIDGE. VERY GOOD MODEL AGREEMENT
EXISTS THAT THE UPPER RIDGE WILL FLATTEN AND GET PUSHED SOUTH...IN
RESPONSE TO A SHORTWAVE ROUNDING THE RIDGE WHICH IS LOCATED OFF BAJA
CALIFORNIA RIGHT NOW. AS THE RIDGE FLATTENS...THE LOW PRESSURE
SYSTEM GETS SENT SOUTHEASTWARD INTO WESTERN IOWA BY 12Z WEDNESDAY.
WARM ADVECTION IS FORECAST AHEAD OF THE LOW OVER THE FORECAST AREA
DURING THE ENTIRE MONDAY NIGHT THROUGH TUESDAY NIGHT. 850MB TEMPS
RESPOND BY CLIMBING TO 6 TO 12C BY 00Z WEDNESDAY...WARMEST IN THE
FAR WESTERN PORTION OF THE FORECAST AREA. EVEN MORE WARMING IS
POSSIBLE TUESDAY NIGHT. THE BIGGER QUESTION...THOUGH...IS WHEN/IF
PRECIPITATION WILL OCCUR. PRECIPITABLE WATER VALUES START OFF FAIRLY
LOW AT 00Z TUESDAY...NEAR A 0.5 INCH. GOOD AGREEMENT EXISTS THAT
THESE WILL SLOWLY CLIMB TO NEAR AN INCH BY 00Z WEDNESDAY.
STILL...ISENTROPIC LIFT IS NOT ALL THAT IMPRESSIVE...SUGGESTING MUCH
OF THE WARM ADVECTION IS JUST GOING INTO WARMING. LIKELY TO SEE AN
INCREASE IN MID AND HIGH CLOUDS...THOUGH. THESE CLOUDS WILL HELP TO
KEEP TEMPERATURES UP MONDAY NIGHT. WITH A WARMER START TO
TUESDAY...INCREASING 850MB TEMPS AND FILTERED SUN...ANTICIPATING
HIGHS AT LEAST IN THE 60S AND POSSIBLY LOW 70S IN THE FAR WEST. BY
TUESDAY NIGHT...WITH THE LOW APPROACHING...THERE IS SOME SUGGESTION
OF LOW TO MID LEVEL FRONTOGENESIS INCREASING. THEREFORE...CHANCES OF
PRECIPITATION ARE NECESSARY TUESDAY NIGHT. DO NOT HAVE CONFIDENCE AT
THIS TIME TO GO HIGHER THAN 50 PERCENT AS WOULD LIKE TO SEE STRONGER
FORCING SIGNALS. WILL CONTINUE TO MENTION THUNDER WITH A PLUME OF
500-1000 J/KG OF MUCAPE ADVECTING INTO THE FRONTOGENESIS ZONE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
300 AM CDT SUN APR 22 2012
22.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN PRETTY GOOD
AGREEMENT THROUGH THE ENTIRE LONG TERM PERIOD WITH BOTH THE UPPER
LEVEL AND SURFACE PATTERNS. FOR MUCH OF THE LONG TERM PERIOD...THE
FORECAST AREA IS UNDER THE INFLUENCE OF A CANADIAN HIGH PRESSURE
AREA WHICH DROPS DOWN INTO THE WESTERN GREAT LAKES REGION THURSDAY
MORNING. PRIOR TO THEN...THE LOW PRESSURE SYSTEM FROM TUESDAY NIGHT
AND THE FRONTOGENESIS ZONE AHEAD OF IT OVER THE AREA SHOULD REMAIN
MOSTLY IN PLACE ON WEDNESDAY...THEN HEAD OFF TO THE EAST WEDNESDAY
NIGHT. MAINTAINED 20-40 PERCENT CHANCES ON WEDNESDAY...HIGHEST
ALONG/SOUTH OF I-90...THEN JUST A 20 PERCENT CHANCE WEDNESDAY NIGHT
FOR THE DEPARTING PRECIPITATION. DRY AND COOLER CONDITIONS
ANTICIPATED FOR THURSDAY THROUGH FRIDAY WITH THAT CANADIAN HIGH
BUILDING DOWN. WENT TOWARDS THE COLD SIDE OF GUIDANCE FOR LOWS
THURSDAY NIGHT...WHERE FREEZE CONDITIONS SEEM LIKELY ALONG AND
NORTH OF I-94. WILL REALLY HAVE TO WATCH THIS NIGHT TEMPERATURE
WISE...GIVEN DEWPOINTS THAT ARE LIKELY TO DROP INTO THE 20S AND
MAYBE EVEN UPPER TEENS. AN UPPER RIDGE ON THE WEST SIDE OF THE
SURFACE HIGH IS ALSO A FEATURE TO WATCH. RIGHT NOW GOOD AGREEMENT
EXISTS THAT THIS UPPER RIDGE GET PUSHED INTO THE AREA ON SATURDAY
AS TROUGHING DEVELOPS OVER MUCH OF THE WESTERN U.S.. WILL SEE IF
THAT PROGRESSION STAYS...BUT WITH THAT RIDGE MOVING IN MEANS WARM
ADVECTION...AND THEREFORE CHANCES OF SHOWERS AND THUNDERSTORMS
ENTER THE PICTURE. SEEMS LIKE THE BETTER CHANCES FOR RAIN WOULD
COME SATURDAY NIGHT AND SUNDAY AS SHORTWAVES EJECT OUT OF THE
WESTERN TROUGH AND MOVE INTO THE AREA.
&&
.AVIATION...
1000 PM CDT SAT APR 21 2012
LOW CONFIDENCE WITH RELATION TO CIGS AS A COMPLEX SCENARIO MAKES
REFINING THE FORECAST DIFFICULT.
SOME CLARITY THOUGH WITH THE LATEST RUC13 AND 00Z NAM12 KEEPING ANY
DEEPER SATURATION...AND MVFR CIGS...WEST OF KLSE. HOWEVER...BOTH
SUGGEST THAT THE TRACK OF THE SOUTHEAST DEPARTING LOW WILL PLACE
KRST ON THE EASTERN FRINGE OF MVFR CIGS OVERNIGHT. WILL ADD SOME
MENTION FOR KRST.
IN ADDITION TO THE CLOUDS...AN INVERTED SFC TROUGH HANGING NORTH OF
THE LOW WILL BE THE FOCUS FOR SCT -SHRA OVERNIGHT. PROBABLY LIGHT
ENOUGH WHERE VSBYS ARE NOT IMPACTED...WITH MINIMAL ACCUMULATIONS.
THE TROUGH COULD REMAIN A FOCUS FOR SOME -SHRA DEVELOPMENT ON
SUNDAY...BUT ALL MESO MODELS ARE SOUR ON THIS POTENTIAL. DEEP
SATURATION REMAINS AROUND THIS FEATURE...BUT A FETCH OF DRIER MID
LEVEL AIR WILL WORK WEST INTO THE MISSISSIPPI RIVER...HELPING TO
CLEAR AT LEAST SOME OF THE LOW CLOUDS OUT.
LOOK FOR WINDS TO TURN SOUTHEAST THIS EVENING...SWINGING TO THE
NORTH BY 00Z MON. HIGH PRESSURE BUILDS ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY LATE MONDAY...AND SHOULD HELP CLEAR MORE OF THE
MOISTURE/CLOUDS OUT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 AM CDT SUN APR 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
1113 AM EDT SUN APR 22 2012
.SYNOPSIS...
A POTENT LOW PRESSURE SYSTEM APPROACHES CONTINUES TO STRENGTHEN
AND APPROACH FROM THE SOUTH THROUGH TONIGHT TO NORTHEAST
PENNSYLVANIA BY MONDAY MORNING...THEN TRACKS NORTHWEST INTO SOUTHEASTERN
ONTARIO BY TUESDAY MORNING. THIS LOW THEN SLOWLY DRIFTS INTO
QUEBEC AS IT WEAKENS INTO WEDNESDAY. ANOTHER STORM SYSTEM
APPROACHES FROM THE WEST WEDNESDAY NIGHT...THEN TRACKS JUST TO OUR
SOUTH ON THURSDAY...BEFORE HEADING TO THE CANADIAN MARITIMES BY
FRIDAY MORNING. HIGH PRESSURE THEN BUILDS IN TO CLOSE THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOOKING AT WATER VAPOR IMAGERY...A STRONG NORTHERN STREAM
SHORTWAVE OVER THE LOWER OHIO VALLEY WAS RACING SE AND CATCHING UP
WITH A SOUTHERN STREAM SYSTEM OVER NORTHERN FLORIDA. THE
INTERACTION BETWEEN THESE TWO UPPER SYSTEMS WILL SERVE TO
STRENGTHEN AND DRAW NORTHWARD AN AREA OF SURFACE LOW PRESSURE OFF
THE CAROLINA COAST.
LIGHT RAIN...WELL AHEAD OF THIS SYSTEM IS BEGINNING TO WORK ITS
WAY INTO THE TRI-STATE. LATEST SREF AND HRRR SEEM TO HAVE A FAIRLY
GOOD HANDLE ON THIS...SO ADJUSTED POPS TODAY ACCORDINGLY. APPEARS
MODERATE-HEAVY RAINFALL WILL HOLD OFF TIL MID-LATE AFTERNOON WHEN
STRONGER FRONTOGENETIC AND Q-G FORCING BEGIN TO REACH THE REGION.
GIVEN CLOUD COVER AND DEVELOPING RAINFALL...DO NOT EXPECT
TEMPERATURES TO RISE MUCH MORE THAN 5 DEGREES OR SO FROM CURRENT
LEVELS. THIS IS ALSO CONSISTENT WITH A BLEND OF MAV/LAV/MET
GUIDANCE WITH NAM 2-METER TEMPERATURES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
CLOSED STACKED LOW TO THE WEST WILL SLOWLY MOVE NORTHWARD IN TIME.
THIS WILL ALLOW A DEEP SOUTHERLY FLOW TO PREVAIL. PLENTY OF WARM AIR
ADVECTION...AND ABUNDANT MOISTURE GETS TRANSPORTED NORTHWARD AND
WILL SET THE STAGE FOR QUITE A BIT OF RAIN TONIGHT ACROSS THE AREA.
MID LEVEL FRONTOGENESIS REMAINS TO THE NW OF THE AREA...BUT DEEP
SOUTHERLY FETCH AND THETA ADVECTION WILL ENSURE RAIN HEAVY AT TIMES
THROUGH MUCH OF THE NIGHT.
THE MODELS ARE IN GENERAL AGREEMENT OF STEERING THE SFC LOW ACROSS
NJ AND TO OUR WEST. PRESSURE GRADIENT TIGHTENS...AND NAM REMAINS ONE
OF THE DEEPER SOLUTIONS WITH REGARD TO THE SFC LOW INITIALLY. EAST
WINDS INCREASE...BUT DO NOT HAVE THE CONFIDENCE TO ISSUE ANY WIND
RELATED HEADLINES AT THIS TIME. MY BEST GUESS IS FOR A FEW REPORTS
CLOSE TO ADVISORY CRITERIA ACROSS PORTIONS OF LONG ISLAND AND
POSSIBLY COASTAL CT. HOWEVER...H8 JET STRENGTH NOT QUITE WHAT I WOULD
WANT IT TO BE FOR WIND ADVISORY LEVEL WINDS VERIFYING HERE...AND
THAT IS ACCORDING TO STRONGER NAM. GFS AND ECMWF ADVERTISE A MUCH
WEAKER JET LOCATED TO THE EAST.
LATEST 6Z NAM DOES FORECAST A 75 KT H8 JET OVER ERN LONG ISLAND AND
SE CT. THESE EASTERN LOCATIONS WILL NEED TO BE WATCHED.
THE MAIN ISSUE WILL BE RAINFALL AMOUNTS. LATEST PRECIPITATION RUN
ACCUMULATIONS FROM 00Z/06Z MODEL SUITE SUGGESTS SLIGHTLY LOWER
AMOUNTS FROM PREVIOUS RUNS. HOWEVER...STILL HAVE ENOUGH SUPPORT TO
CONTINUE THE FLOOD WATCH. AS MENTIONED...RAIN WILL TAPER OFF
MONDAY AS DRIER AIR ALOFT MOVES IN. THE BULK OF THE RAIN WILL BE
FROM THIS AFTERNOON INTO EARLY MONDAY MORNING...SO FLOOD WATCH
TIMING LOOKS GOOD. SEE THE HYDROLOGY SECTION FOR FURTHER
DETAILS.
TEMPS CLOSE TO MOS THROUGH THIS TIME FRAME...WITH SMALLER DIURNAL
DIFFERENCES NOTED DUE TO CLOUDS AND ONSHORE WINDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
UNSETTLED WEATHER REMAINS IN THE FORECAST FOR THE START OF THE LONG
TERM PERIOD. DEEP...ELONGATED UPPER TROUGH REMAINS ALONG THE EASTERN
SEABOARD AND WILL BE SLOW TO DEPART. NORTHERLY FLOW WILL USER A
RELATIVELY DRY AIR MASS TO THE REGION...HOWEVER...WITH WITH SEVERAL
STRONG SHORTWAVES ROTATING THROUGH THE REGION ASSOCIATED WITH THE
UPPER LOW...WILL KEEP AT LEAST A CHANCE FOR PRECIP IN THE FORECAST
THROUGH TUESDAY NIGHT. ENOUGH COLD AIR MAY GET WRAPPED INTO THE
REGION TUESDAY NIGHT TO ALLOW FOR SOME SNOW SHOWERS TO MIX WITH THE
RAIN ACROSS WESTERN PORTIONS OF ORANGE COUNTY.
A WEAK CLIPPER SYSTEM APPROACHES FROM THE WEST WEDNESDAY. WITH
TIMING UNCERTAINTIES AND TO KEEP FORECAST CONTINUITY HAVE KEPT
CHANCE POPS THROUGH WEDNESDAY...AND THEN BACK TO CHANCE LATE
WEDNESDAY INTO THURSDAY.
UPPER TROUGH MOVES TO THE EAST THURSDAY NIGHT INTO THE WEEKEND AS
RIDGE BUILDS TO THE WEST. SURFACE HIGH BUILDS FROM THE NORTH. DEEP
NORTHWEST FLOW ACROSS THE AREA LATE IN THE WEEK AND INTO THE
UPCOMING WEEKEND WILL KEEP TEMPERATURES COOL.
FOR WEDNESDAY THROUGH SATURDAY USED A BLEND OF THE GFS AND HPC
GUIDANCE.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
DEEPENING LOW PRES WILL TRACK ALONG THE EASTERN SEABOARD LATER
TODAY...PASSING JUST WEST OF THE NYC METRO AREA EARLY MON
MORNING...AND THEN MOVING INTO CENTRAL PA/NY LATER MON.
RAIN SHIELD NOW PAST NYC METRO AND WILL MOVE INLAND AND TO THE CT
COAST LATE THIS MORNING. EXPECT MAINLY VFR CONDS TO START...BUT
BAND OF MODERATE RAIN JUST OFF THE NJ COAST COULD BRING IFR
CONDITIONS TO KISP/KBDR EARLY THIS AFTERNOON.
IFR CONDITIONS SHOULD ENCOMPASS THE ENTIRE REGION BY LATE DAY...
WITH INCREASING E WINDS. HEAVY RAIN WILL MOVE IN AFTER DARK...
WITH IFR/LIFR CONDITIONS.
N WINDS AT OR JUST UNDER 10 KT THIS MORNING SHOULD VEER NE AND
INCREASE SLIGHTLY THIS AFTERNOON...THEN VEER MORE E-NE AND INCREASE
TO 15-20 KT WITH 20-30 KT GUSTS BY TONIGHT. WINDS WILL INCREASE
FURTHER THIS EVENING TO 20-30 KT WITH 30+ KT GUSTS. STRONG LOW
LEVEL JET WILL CAUSE LLWS LATER TONIGHT.
OUTLOOK FOR 12Z MON THROUGH THU...
.MON...WINDS DIMINISH AND SHIFT TO THE SE IN THE MORNING...THEN TO
THE SW AND INCREASE ONCE AGAIN TO 15-25 KT WITH 30-35 KT GUSTS.
CONDS IMPROVE TO VFR BY AFTERNOON.
.MON NIGHT-WED...VFR. GUSTY WINDS.
.WED NIGHT-THU...MVFR OR LOWER POSSIBLE.
&&
.MARINE...
MINOR CHANGES TO GRIDS THIS MORNING...WITH MAIN CHANGE TO DELAY
SLIGHTLY ONSET OF STRONGER WINDS PER LATEST TRENDS IN OBSERVATIONS
AND GUIDANCE.
NORTHERLY WINDS EARLY THIS MORNING WILL TURN TOWARD THE EAST AND
INCREASE THIS AFTERNOON AS LOW PRESSURE APPROACHES FROM THE SOUTH.
THIS LOW DEEPENS AS IT PASSES TO THE WEST OF THE WATERS TONIGHT.
EASTERLY GALES CAN BE EXPECTED TONIGHT. THESE WINDS THEN SHIFT TO
THE SOUTH BY MONDAY MORNING. THERE WILL BE A LULL IN THE WINDS AS
THE LOW NEARS THE WATERS LATE TONIGHT THROUGH MONDAY MORNING. THEN
SOUTHERLY WINDS INCREASE MONDAY AFTERNOON AND COULD APPROACH GALE
FORCE ONCE AGAIN BY LATE IN THE DAY. HOWEVER THE TIME BETWEEN GALE
FORCE WINDS TONIGHT AND LATE MONDAY IS TOO GREAT TO EXTEND THE GALE
WARNING AT THIS TIME.
SEAS WILL BUILD TODAY AND TONIGHT...WITH ROUGH CONDITIONS
ANTICIPATED THROUGH MONDAY.
STRONG SCA CONDITIONS...POSSIBLY APPROACHING GALES AT TIMES ON THE
OCEAN WATERS...WILL PERSIST THROUGH TUESDAY NIGHT...THEN CONDITIONS
GRADUALLY SUBSIDE TO SUB-SCA CRITERIA.
NORTHWEST WINDS BEHIND DEPARTING LOW THURSDAY NIGHT MAY AGAIN COME
UP TO SMALL CRAFT ACROSS THE WATERS...ESPECIALLY ON THE OCEAN.
&&
.HYDROLOGY...
HEAVY RAIN MOVES IN FROM THE SOUTH THIS AFTERNOON AND CONTINUES
TONIGHT BEFORE TAPERING OFF MONDAY. RAINFALL AMOUNTS SHOULD RANGE
FROM 2 TO 3.5 INCHES. LOCALLY HIGHER AMOUNTS CANNOT BE RULED OUT.
MAIN STEM RIVERS SHOULD NOT HAVE ANY PROBLEMS. EVEN 4 INCH AMOUNTS
KEEP RIVER LEVELS BELOW THEIR RESPECTIVE FLOOD STAGES.
HOWEVER...FLASHY SMALL STREAMS COULD FLOOD. SIGNIFICANT URBAN AND
POOR DRAINAGE FLOODING IS POSSIBLE. HARD DRY GROUND DUE TO LACK
OF RECENT RAINFALL...AND STORM DRAINS THAT HAVE NOT YET BEEN
CLEARED OF WINTER DEBRIS...MAY ACTUALLY CONTRIBUTE TO RUNOFF.
THIS RAIN WILL HELP ALLEVIATE THE MODERATE TO SEVERE DROUGHT
CONDITIONS.
MONDAY NIGHT AND TUESDAY...UP TO A TENTH OF AN INCH IN POSSIBLE IN
SCATTERED SHOWERS.
&&
.TIDES/COASTAL FLOODING...
WITH THE REGION AROUND A NEW MOON IN THE LUNAR CYCLE...AND STRONG
EASTERLY WINDS FORECAST LATE TODAY AND TONIGHT...IT APPEARS THAT
MINOR COASTAL FLOOD BENCHMARKS COULD BE REACHED ON WESTERN LONG
ISLAND SOUND AROUND THE TIME OF HIGH TIDE. HIGH TIDE OCCURS AFTER
MIDNIGHT TONIGHT. HOWEVER...LATEST COASTAL FLOODING GUIDANCE
INDICATES TIDE LEVELS FALL SHORT. MY FEELING IS THAT THIS GUIDANCE
IS UNDERDONE. HOWEVER...I DO NOT HAVE THE CONFIDENCE NEEDED TO ISSUE
A COASTAL FLOOD ADVISORY AT THIS TIME.
BECAUSE THE HIGH TIDE FOR NY HARBOR/SOUTH SHORE BAYS OF LONG
ISLAND/NYC OCCURS THIS EVENING...THE WINDS LIKELY WILL NOT BE
STRONG ENOUGH BY THEN TO ACHIEVE THE AROUND 1.5 FT DEPARTURES
NEEDED FOR MINOR COASTAL FLOODING.
FOR THE MONDAY MORNING/EARLY AFTERNOON HIGH TIDE CYCLE...THE WINDS
WILL BE INCREASING OUT OF THE SOUTH...AND THIS WILL HELP KEEP TIDAL
DEPARTURES UP IN THE SOUTH SHORE BAYS...WHILE ALLOWING TIDAL PILING
TO DISSIPATE IN THE SOUND AND HARBOR. AS A RESULT...CURRENTLY ONLY
SEE THE POTENTIAL FOR MINOR COASTAL FLOODING...IF ANY...IN THE SOUTH
SHORE BAYS OF NYC/NASSAU COUNTY ON MONDAY MORNING. TIDAL DEPARTURES
OF 2-2.5 ARE NEEDED TO REACH COASTAL FLOOD BENCHMARKS FOR THE MONDAY
MORNING HIGH TIDE.
HIGH SURF IS POSSIBLE ALONG THE BEACHES TONIGHT AS SEAS BECOME QUITE
ROUGH AND SWELLS INCREASE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH MONDAY MORNING FOR CTZ005>012.
NY...FLOOD WATCH THROUGH MONDAY MORNING FOR NYZ067>075-078>081-
176>179.
NJ...FLOOD WATCH THROUGH MONDAY MORNING FOR NJZ002-004-006-103>108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345-350-353-355.
GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EDT MONDAY FOR
ANZ330-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...MALOIT/MPS/PW
NEAR TERM...MALOIT
SHORT TERM...PW
LONG TERM...MPS
AVIATION...GOODMAN/MPS
MARINE...MALOIT/MPS/PW
HYDROLOGY...PW
TIDES/COASTAL FLOODING...PW
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1100 AM EDT SUN APR 22 2012
.SYNOPSIS...
A POTENT LOW PRESSURE SYSTEM APPROACHES CONTINUES TO STRENGTHEN
AND APPROACH FROM THE SOUTH THROUGH TONIGHT TO NORTHEAST
PENNSYLVANIA BY MONDAY MORNING...THEN TRACKS NORTHWEST INTO SOUTHEASTERN
ONTARIO BY TUESDAY MORNING. THIS LOW THEN SLOWLY DRIFTS INTO
QUEBEC AS IT WEAKENS INTO WEDNESDAY. ANOTHER STORM SYSTEM
APPROACHES FROM THE WEST WEDNESDAY NIGHT...THEN TRACKS JUST TO OUR
SOUTH ON THURSDAY...BEFORE HEADING TO THE CANADIAN MARITIMES BY
FRIDAY MORNING. HIGH PRESSURE THEN BUILDS IN TO CLOSE THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOOKING AT WATER VAPOR IMAGERY...A STRONG NORTHERN STREAM
SHORTWAVE OVER THE LOWER OHIO VALLEY WAS RACING SE AND CATCHING UP
WITH A SOUTHERN STREAM SYSTEM OVER NORTHERN FLORIDA. THE
INTERACTION BETWEEN THESE TWO UPPER SYSTEMS WILL SERVE TO
STRENGTHEN AND DRAW NORTHWARD AN AREA OF SURFACE LOW PRESSURE OFF
THE CAROLINA COAST.
LIGHT RAIN...WELL AHEAD OF THIS SYSTEM IS BEGINNING TO WORK ITS
WAY INTO THE TRI-STATE. LATEST SREF AND HRRR SEEM TO HAVE A FAIRLY
GOOD HANDLE ON THIS...SO ADJUSTED POPS TODAY ACCORDINGLY. APPEARS
MODERATE-HEAVY RAINFALL WILL HOLD OFF TIL MID-LATE AFTERNOON WHEN
STRONGER FRONTOGENETIC AND Q-G FORCING BEGIN TO REACH THE REGION.
GIVEN CLOUD COVER AND DEVELOPING RAINFALL...DO NOT EXPECT
TEMPERATURES TO RISE MUCH MORE THAN 5 DEGREES OR SO FROM CURRENT
LEVELS. THIS IS ALSO CONSISTENT WITH A BLEND OF MAV/LAV/MET
GUIDANCE WITH NAM 2-METER TEMPERATURES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
CLOSED STACKED LOW TO THE WEST WILL SLOWLY MOVE NORTHWARD IN TIME.
THIS WILL ALLOW A DEEP SOUTHERLY FLOW TO PREVAIL. PLENTY OF WARM AIR
ADVECTION...AND ABUNDANT MOISTURE GETS TRANSPORTED NORTHWARD AND
WILL SET THE STAGE FOR QUITE A BIT OF RAIN TONIGHT ACROSS THE AREA.
MID LEVEL FRONTOGENESIS REMAINS TO THE NW OF THE AREA...BUT DEEP
SOUTHERLY FETCH AND THETA ADVECTION WILL ENSURE RAIN HEAVY AT TIMES
THROUGH MUCH OF THE NIGHT.
THE MODELS ARE IN GENERAL AGREEMENT OF STEERING THE SFC LOW ACROSS
NJ AND TO OUR WEST. PRESSURE GRADIENT TIGHTENS...AND NAM REMAINS ONE
OF THE DEEPER SOLUTIONS WITH REGARD TO THE SFC LOW INITIALLY. EAST
WINDS INCREASE...BUT DO NOT HAVE THE CONFIDENCE TO ISSUE ANY WIND
RELATED HEADLINES AT THIS TIME. MY BEST GUESS IS FOR A FEW REPORTS
CLOSE TO ADVISORY CRITERIA ACROSS PORTIONS OF LONG ISLAND AND
POSSIBLY COASTAL CT. HOWEVER...H8 JET STRENGTH NOT QUITE WHAT I WOULD
WANT IT TO BE FOR WIND ADVISORY LEVEL WINDS VERIFYING HERE...AND
THAT IS ACCORDING TO STRONGER NAM. GFS AND ECMWF ADVERTISE A MUCH
WEAKER JET LOCATED TO THE EAST.
LATEST 6Z NAM DOES FORECAST A 75 KT H8 JET OVER ERN LONG ISLAND AND
SE CT. THESE EASTERN LOCATIONS WILL NEED TO BE WATCHED.
THE MAIN ISSUE WILL BE RAINFALL AMOUNTS. LATEST PRECIPITATION RUN
ACCUMULATIONS FROM 00Z/06Z MODEL SUITE SUGGESTS SLIGHTLY LOWER
AMOUNTS FROM PREVIOUS RUNS. HOWEVER...STILL HAVE ENOUGH SUPPORT TO
CONTINUE THE FLASH FLOOD WATCH. SEE THE HYDROLOGY SECTION FOR
FURTHER DETAILS.
AS MENTIONED...RAIN WILL TAPER OFF MONDAY AS DRIER AIR ALOFT MOVES
IN. THE BULK OF THE RAIN WILL BE FROM THIS AFTERNOON INTO EARLY
MONDAY MORNING...SO FLOOD WATCH TIMING LOOKS GOOD.
TEMPS CLOSE TO MOS THROUGH THIS TIME FRAME...WITH SMALLER DIURNAL
DIFFERENCES NOTED DUE TO CLOUDS AND ONSHORE WINDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
UNSETTLED WEATHER REMAINS IN THE FORECAST FOR THE START OF THE LONG
TERM PERIOD. DEEP...ELONGATED UPPER TROUGH REMAINS ALONG THE EASTERN
SEABOARD AND WILL BE SLOW TO DEPART. NORTHERLY FLOW WILL USER A
RELATIVELY DRY AIR MASS TO THE REGION...HOWEVER...WITH WITH SEVERAL
STRONG SHORTWAVES ROTATING THROUGH THE REGION ASSOCIATED WITH THE
UPPER LOW...WILL KEEP AT LEAST A CHANCE FOR PRECIP IN THE FORECAST
THROUGH TUESDAY NIGHT. ENOUGH COLD AIR MAY GET WRAPPED INTO THE
REGION TUESDAY NIGHT TO ALLOW FOR SOME SNOW SHOWERS TO MIX WITH THE
RAIN ACROSS WESTERN PORTIONS OF ORANGE COUNTY.
A WEAK CLIPPER SYSTEM APPROACHES FROM THE WEST WEDNESDAY. WITH
TIMING UNCERTAINTIES AND TO KEEP FORECAST CONTINUITY HAVE KEPT
CHANCE POPS THROUGH WEDNESDAY...AND THEN BACK TO CHANCE LATE
WEDNESDAY INTO THURSDAY.
UPPER TROUGH MOVES TO THE EAST THURSDAY NIGHT INTO THE WEEKEND AS
RIDGE BUILDS TO THE WEST. SURFACE HIGH BUILDS FROM THE NORTH. DEEP
NORTHWEST FLOW ACROSS THE AREA LATE IN THE WEEK AND INTO THE
UPCOMING WEEKEND WILL KEEP TEMPERATURES COOL.
FOR WEDNESDAY THROUGH SATURDAY USED A BLEND OF THE GFS AND HPC
GUIDANCE.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
DEEPENING LOW PRES WILL TRACK ALONG THE EASTERN SEABOARD LATER
TODAY...PASSING JUST WEST OF THE NYC METRO AREA EARLY MON
MORNING...AND THEN MOVING INTO CENTRAL PA/NY LATER MON.
RAIN SHIELD NOW PAST NYC METRO AND WILL MOVE INLAND AND TO THE CT
COAST LATE THIS MORNING. EXPECT MAINLY VFR CONDS TO START...BUT
BAND OF MODERATE RAIN JUST OFF THE NJ COAST COULD BRING IFR
CONDITIONS TO KISP/KBDR EARLY THIS AFTERNOON.
IFR CONDITIONS SHOULD ENCOMPASS THE ENTIRE REGION BY LATE DAY...
WITH INCREASING E WINDS. HEAVY RAIN WILL MOVE IN AFTER DARK...
WITH IFR/LIFR CONDITIONS.
N WINDS AT OR JUST UNDER 10 KT THIS MORNING SHOULD VEER NE AND
INCREASE SLIGHTLY THIS AFTERNOON...THEN VEER MORE E-NE AND INCREASE
TO 15-20 KT WITH 20-30 KT GUSTS BY TONIGHT. WINDS WILL INCREASE
FURTHER THIS EVENING TO 20-30 KT WITH 30+ KT GUSTS. STRONG LOW
LEVEL JET WILL CAUSE LLWS LATER TONIGHT.
OUTLOOK FOR 12Z MON THROUGH THU...
.MON...WINDS DIMINISH AND SHIFT TO THE SE IN THE MORNING...THEN TO
THE SW AND INCREASE ONCE AGAIN TO 15-25 KT WITH 30-35 KT GUSTS.
CONDS IMPROVE TO VFR BY AFTERNOON.
.MON NIGHT-WED...VFR. GUSTY WINDS.
.WED NIGHT-THU...MVFR OR LOWER POSSIBLE.
&&
.MARINE...
MINOR CHANGES TO GRIDS THIS MORNING...WITH MAIN CHANGE TO DELAY
SLIGHTLY ONSET OF STRONGER WINDS PER LATEST TRENDS IN OBSERVATIONS
AND GUIDANCE.
NORTHERLY WINDS EARLY THIS MORNING WILL TURN TOWARD THE EAST AND
INCREASE THIS AFTERNOON AS LOW PRESSURE APPROACHES FROM THE SOUTH.
THIS LOW DEEPENS AS IT PASSES TO THE WEST OF THE WATERS TONIGHT.
EASTERLY GALES CAN BE EXPECTED TONIGHT. THESE WINDS THEN SHIFT TO
THE SOUTH BY MONDAY MORNING. THERE WILL BE A LULL IN THE WINDS AS
THE LOW NEARS THE WATERS LATE TONIGHT THROUGH MONDAY MORNING. THEN
SOUTHERLY WINDS INCREASE MONDAY AFTERNOON AND COULD APPROACH GALE
FORCE ONCE AGAIN BY LATE IN THE DAY. HOWEVER THE TIME BETWEEN GALE
FORCE WINDS TONIGHT AND LATE MONDAY IS TOO GREAT TO EXTEND THE GALE
WARNING AT THIS TIME.
SEAS WILL BUILD TODAY AND TONIGHT...WITH ROUGH CONDITIONS
ANTICIPATED THROUGH MONDAY.
STRONG SCA CONDITIONS...POSSIBLY APPROACHING GALES AT TIMES ON THE
OCEAN WATERS...WILL PERSIST THROUGH TUESDAY NIGHT...THEN CONDITIONS
GRADUALLY SUBSIDE TO SUB-SCA CRITERIA.
NORTHWEST WINDS BEHIND DEPARTING LOW THURSDAY NIGHT MAY AGAIN COME
UP TO SMALL CRAFT ACROSS THE WATERS...ESPECIALLY ON THE OCEAN.
&&
.HYDROLOGY...
HEAVY RAIN MOVES IN FROM THE SOUTH THIS AFTERNOON AND CONTINUES
TONIGHT BEFORE TAPERING OFF MONDAY. RAINFALL AMOUNTS SHOULD RANGE
FROM 2 TO 3.5 INCHES. LOCALLY HIGHER AMOUNTS CANNOT BE RULED OUT.
MAIN STEM RIVERS SHOULD NOT HAVE ANY PROBLEMS. EVEN 4 INCH AMOUNTS
KEEP RIVER LEVELS BELOW THEIR RESPECTIVE FLOOD STAGES.
HOWEVER...FLASHY SMALL STREAMS COULD FLOOD. SIGNIFICANT URBAN AND
POOR DRAINAGE FLOODING IS POSSIBLE. HARD DRY GROUND DUE TO LACK
OF RECENT RAINFALL...AND STORM DRAINS THAT HAVE NOT YET BEEN
CLEARED OF WINTER DEBRIS...MAY ACTUALLY CONTRIBUTE TO RUNOFF.
THIS RAIN WILL HELP ALLEVIATE THE MODERATE TO SEVERE DROUGHT
CONDITIONS.
MONDAY NIGHT AND TUESDAY...UP TO A TENTH OF AN INCH IN POSSIBLE IN
SCATTERED SHOWERS.
&&
.TIDES/COASTAL FLOODING...
WITH THE REGION AROUND A NEW MOON IN THE LUNAR CYCLE...AND STRONG
EASTERLY WINDS FORECAST LATE TODAY AND TONIGHT...IT APPEARS THAT
MINOR COASTAL FLOOD BENCHMARKS COULD BE REACHED ON WESTERN LONG
ISLAND SOUND AROUND THE TIME OF HIGH TIDE. HIGH TIDE OCCURS AFTER
MIDNIGHT TONIGHT. HOWEVER...LATEST COASTAL FLOODING GUIDANCE
INDICATES TIDE LEVELS FALL SHORT. MY FEELING IS THAT THIS GUIDANCE
IS UNDERDONE. HOWEVER...I DO NOT HAVE THE CONFIDENCE NEEDED TO ISSUE
A COASTAL FLOOD ADVISORY AT THIS TIME.
BECAUSE THE HIGH TIDE FOR NY HARBOR/SOUTH SHORE BAYS OF LONG
ISLAND/NYC OCCURS THIS EVENING...THE WINDS LIKELY WILL NOT BE
STRONG ENOUGH BY THEN TO ACHIEVE THE AROUND 1.5 FT DEPARTURES
NEEDED FOR MINOR COASTAL FLOODING.
FOR THE MONDAY MORNING/EARLY AFTERNOON HIGH TIDE CYCLE...THE WINDS
WILL BE INCREASING OUT OF THE SOUTH...AND THIS WILL HELP KEEP TIDAL
DEPARTURES UP IN THE SOUTH SHORE BAYS...WHILE ALLOWING TIDAL PILING
TO DISSIPATE IN THE SOUND AND HARBOR. AS A RESULT...CURRENTLY ONLY
SEE THE POTENTIAL FOR MINOR COASTAL FLOODING...IF ANY...IN THE SOUTH
SHORE BAYS OF NYC/NASSAU COUNTY ON MONDAY MORNING. TIDAL DEPARTURES
OF 2-2.5 ARE NEEDED TO REACH COASTAL FLOOD BENCHMARKS FOR THE MONDAY
MORNING HIGH TIDE.
HIGH SURF IS POSSIBLE ALONG THE BEACHES TONIGHT AS SEAS BECOME QUITE
ROUGH AND SWELLS INCREASE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH THROUGH MONDAY MORNING FOR CTZ005>012.
NY...FLOOD WATCH THROUGH MONDAY MORNING FOR NYZ067>075-078>081-
176>179.
NJ...FLOOD WATCH THROUGH MONDAY MORNING FOR NJZ002-004-006-103>108.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
335-338-340-345-350-353-355.
GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EDT MONDAY FOR
ANZ330-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...MALOIT/MPS/PW
NEAR TERM...MALOIT
SHORT TERM...PW
LONG TERM...MPS
AVIATION...GOODMAN/MPS
MARINE...MALOIT/MPS/PW
HYDROLOGY...PW
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MIAMI FL
950 AM EDT SUN APR 22 2012
.UPDATE...
THE 12Z SOUNDING THIS MORNING SHOWED 110 KT UPPER JET STREAK OVER
THE REGION...BUT DRIER AND WARMER AIR ALOFT AND COOLER AIR IN THE
LOW LEVELS. WINDS AROUND 1 KFT WERE 30 KNOTS...SO THE LEFTOVER
SHOWERS THIS MORNING COULD PRODUCE SOME WINDS AROUND 40 MPH. AN
ISOLATED THUNDERSTORM IS POSSIBLE THIS MORNING BUT EXPECT MAINLY
ISOLATED TO SCATTERED SHOWERS BEFORE THE FRONT MOVES THROUGH.
VISIBLE SATELLITE THIS MORNING SHOWED STABLY STRATIFIED AIR OVER
THE NORTHERN GULF. THE SQUALL LINE THAT MOVED ACROSS SOUTH
FLORIDA EARLY THIS MORNING HAD MOVED ACROSS THE BAHAMAS. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOWED THE UPPER LOW OVER THE
EASTERN GULF AND NORTH FLORIDA LIFTING OUT TO THE NORTHEAST AND
WEAKENING AS A STRONG VORT WAS DIVING DOWN ACROSS THE MIDWEST.
SURFACE LOW PRESSURE OVER THE FAR WESTERN ATLANTIC IS EXPECTED TO
ACCELERATE TO THE NORTHEAST AND BE OFF THE NORTHEAST COAST BY
TONIGHT.
SURFACE ANALYSIS THIS MORNING SHOWED THAT THE COLD FRONT WAS
STILL HANGING BACK OVER THE EASTERN GULF THIS MORNING...JUST TO
THE WEST OF THE NAPLES AREA. THIS FRONT IS EXPECTED TO MOVE
THROUGH THE REGION TODAY...WITH WINDY CONDITIONS THIS AFTERNOON.
GUSTS UP TO 40 MPH ARE POSSIBLE ACROSS BROWARD...MIAMI
DADE...MAINLAND MONROE AND COASTAL COLLIER COUNTY BEHIND THE FRONT
WHERE A WIND ADVISORY IS IN EFFECT FROM 11 AM THROUGH 8 PM THIS
EVENING. WITH EXCELLENT MIXING DUE TO STRONG WESTERLY WINDS AND
WITH AT LEAST DECENT DAYTIME HEATING EXPECTED...SOME LOCATIONS
ALONG THE EAST COAST COULD REACH THE MIDDLE 80S. SO BUMPED UP
TEMPERATURES A COUPLE DEGREES FOR THE EAST COAST METROS TO 84-85
DEGREES.
THERE IS A HIGH RISK OF RIP CURRENTS AT THE GULF COAST BEACHES
TODAY DUE TO THE STRONG WESTERLY FLOW. THERE ALSO MAY BE SOME
MINOR COASTAL FLOODING ALONG THE COLLIER COUNTY COAST AT HIGH TIDE
THIS AFTERNOON AS WATER LEVELS REACH 1-2 FEET ABOVE NORMAL HIGH
TIDE. THE ONLY OTHER CHANGE TO THE GOING FORECAST WAS TO LOWER SKY
COVER THIS MORNING TO ACCOUNT FOR CURRENT CONDITIONS.
&&
.PREV DISCUSSION... /ISSUED 803 AM EDT SUN APR 22 2012/
AVIATION...A STRONG COLD FRONT WILL PASS THROUGH THE REGION THIS
MORNING. WIND SPEEDS WILL BE THE PRIMARY CONCERN WITH FREQUENT
GUSTS OF 20 TO 30 KNOTS EXPECTED AFTER 14Z. A FEW SHOWERS WILL
ALSO PROGRESS ACROSS THE AREA, PERHAPS PERSISTING INTO THE
AFTERNOON WITH VCSH ASSIGNED. BRIEF MVFR-IFR CONDITIONS POSSIBLE
IN ANY SHRA, OTHERWISE VFR. WINDS WILL GRADUALLY DECREASE THIS
EVENING, ALTHOUGH WILL REMAIN GUSTY UNTIL AT LEAST 00Z.
PREV DISCUSSION... /ISSUED 620 AM EDT SUN APR 22 2012/
SHORT TERM...
CURRENTLY (07Z)...A SQUALL LINE EXTENDING FROM LAKE OKEECHOBEE
SOUTHWEST TO MAINLAND MONROE MOVING EAST AT 35 MPH. LOCAL
ESTIMATES HAVE THIS LINE REACHING PALM BEACH BEFORE 5 AM AND METRO
AREAS OF BROWARD AND MIAMI-DADE COUNTIES RIGHT ABOUT 5 AM THIS
MORNING. SEVERAL ELEMENTS ALONG THIS LINE SHOW BROAD AND WEAK
CIRCULATION SIGNATURES, BUT MAINLY RADAR ESTIMATES OF 40-50 MPH. A
TORNADO WATCH REMAINS IN EFFECT FOR ALL OF SOUTH FLORIDA AT LEAST
THROUGH 7 AM. AT THAT TIME THE LINE IS EXPECTED TO HAVE MOVE OVER
THE NEAR SHORE ATLANTIC WATERS.
TODAY THROUGH TUESDAY...VIGOROUS SHORT WAVE TROUGH AND ASSOCIATED
SFC LOW/COLD FRONT SHOULD MOVE RAPIDLY EASTWARD AND BE EAST OF THE
PENINSULA BY THIS EVENING WITH SIGNIFICANTLY DRY CONDITIONS BEHIND
IT. A RATHER TIGHT PRESS GRADIENT SHOULD DEVELOP BETWEEN THE SFC
LOW AND A RIDGE BUILDING OVER THE GOM RESULTING IN VERY WINDY
CONDITIONS ACROSS S. FLA THIS AFTERNOON. SOME PORTIONS OF S.
FLA...NAMELY COASTAL COLLIER, MAINLAND MONROE AND METRO AREAS OF
MIAMI-DADE AND BROWARD COULD SEE WIND GUSTS TO 35 MPH OR HIGHER
FROM MID-MORNING THROUGH THIS AFTERNOON. BASED ON THIS...DECIDED TO
ISSUED A WIND ADVISORY FOR THOSE AREAS FROM 15Z TO 24Z TODAY.
THE GULF OF MEX RIDGE SHOULD CONTINUE TO BUILD EAST THROUGH THE
EARLY PART OF NEXT WEEK WITH DRY CONDITIONS CONTINUING. A COOL
AIRMASS SHOULD ALSO SPREAD SOUTH ACROSS THE AREA WITH BOTH MIN/MAX
TEMPS A GOOD 7 TO 10 DEGREES BELOW SEASONAL VALUES.
A STRONG WESTERLY FLOW WILL ALSO RESULT IN VERY ROUGH SURF
CONDITIONS AND HIGH RISK OF RIP CURRENTS ALONG THE SOUTHWEST COAST
BEACHES TODAY.
LONG TERM...WEDNESDAY THROUGH SATURDAY...A DEEP LAYER RIDGE WILL
REMAIN POSITIONED OVER THE REGION KEEPING ANY SIGNIFICANT FEATURE
FROM APPROACHING THE LOCAL AREA AND DRY CONDITIONS PREVAILING
THROUGH THIS PERIOD. ALTHOUGH MILD AND PLEASANT CONDITIONS ARE
EXPECTED WITH SLIGHTLY COOLER THAN SEASONAL TEMPS, A GRADUAL
WARMING TREND SHOULD BEGIN BY MID WEEK WITH MAX AFTERNOON
TEMPS REACHING THE MID 80S BY THE WEEKEND.
MARINE...TIGHTENING OF THE PRESSURE GRADIENT BEHIND THE SFC
LOW/CD FRONT WILL KEEP SFC WINDS WELL ABOVE ADVISORY CRITERIA
ACROSS ALL LOCAL WATERS AT LEAST TONIGHT WITH A GRADUAL
IMPROVEMENT BY MONDAY MORNING.
FIRE WEATHER...A VERY DRY AIRMASS SHOULD SPREAD SOUTH WITH RH
VALUES POSSIBLY FALLING BELOW 35% ACROSS A GOOD PORTION OF SOUTH
FLORIDA BY MONDAY AFTERNOON AND ACROSS ALL OF THE AREA BY TUESDAY.
AT THIS TIME...A FIRE WEATHER WATCH IS NOT BEING CONTEMPLATED AT
THIS TIME...HOWEVER IF THIS TREND CONTINUES A WATCH COULD BE
ISSUED IN FURTHER FORECAST ISSUANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 63 80 60 / 30 10 - -
FORT LAUDERDALE 83 65 81 61 / 30 10 - -
MIAMI 83 65 81 61 / 30 10 - -
NAPLES 81 65 79 60 / 30 10 - -
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR COASTAL BROWARD-
COASTAL COLLIER-COASTAL MIAMI DADE-FAR SOUTH MIAMI DADE-
INLAND MIAMI DADE-MAINLAND MONROE-METRO BROWARD-METRO MIAMI
DADE.
HIGH RIP CURRENT RISK THROUGH MONDAY MORNING FOR COASTAL COLLIER.
AM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR BISCAYNE BAY-
COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT
20 NM-COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH,
FL OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE
BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
EXTENDING FROM 20 NM TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LAKE
OKEECHOBEE.
GM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR COASTAL WATERS
FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM-COASTAL
WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT 20 NM-
GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING
FROM 20 TO 60 NM.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...14/MJB
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1047 AM EDT SUN APR 22 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 248 AM EDT SUN APR 22 2012
A STRONG LOW PRESSURE SYSTEM MOVING ALONG THE EAST COAST WILL
DOMINATE INDIANA WEATHER INTO TUESDAY. AT THAT POINT...ANOTHER LOW
PRESSURE SYSTEM TRAVELING FROM THE NORTH PLAINS TO THE OHIO VALLEY
WILL TAKE CHARGE OF HOOSIER WEATHER. FINALLY...A LARGE AREA OF
HIGH PRESSURE WILL MOVE IN THURSDAY AND STICK AROUND INTO THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1046 AM EDT SUN APR 22 2012
DRY FORECAST FOR TODAY STILL LOOKS GOOD WITH ONLY PRECIPITATION
OVER SOUTHERN ILLINOIS CURRENTLY MOVING TO THE SOUTHEAST. INCREASED
PERCENTAGE OF SKY COVER TO BETTER MATCH SATELLITE LOOP BUT THIS
DID NOT RESULT IN ANY CHANGE TO THE ZFP WORDING. HIGH TEMPERATURES
IN THE LOW 50S EAST TO AROUND 60 SOUTHWEST STILL LOOK REASONABLE
AND WITH HRRR GOING WARMER BUT RUC AND SREFS GOING COLDER THINK
LEAVING HIGHS ALONE AT THIS POINT IS THE BEST BET. COULD SEE SOME
WIND GUSTS AROUND 20-25KTS THIS AFTERNOON/EVENING BASED ON
FORECAST SOUNDINGS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 248 AM EDT SUN APR 22 2012
BIGGEST PROBLEM IS IF ANY POPS NEEDED TUESDAY NIGHT.
DONT SEE NEED FOR ANY BEFORE THEN. MAIN MODEL FIELDS CLOSE ON BIG
LOW ALOFT SLOWLY PULLING AWAY. CAN NOT SEE ANYTHING THAT WOULD
JUSTIFY ON AND OFF SLGT CHANCE MET HAS MONDAY NIGHT OR
TUESDAY...SO GOING WITH MAV. PROBABLY MOSTLY CLEAR TOMORROW AND
TOMORROW NIGHT. MAY SEE SOME CLOUDS IN WARM ADVECTION ON TUESDAY.
RETURNING TO TUESDAY NIGHT...LATEST MEX HAS BACKED AWAY FROM
CHANCE POPS IT HAD EARLIER. THIS SEEMS LOGICAL SINCE LARGE RIDGE
SHOULD STILL BE TO OUR WEST. FOR JUST ONE RUN THAT FAR OUT I AM
NOT WILLING TO GO ALL THE WAY FROM CHANCE TO TOTALLY DRY...BUT
WILL CUT BACK TO SLIGHT CHANCE.
GUIDANCE TEMPS VERY CLOSE...WHICH MAKES SENSE CONSIDERING
SIMILARITY OF PARENT MODELS. TO EXTENT THEY DIFFER USING
CONSENSUS TO CAPTURE BEST OF BOTH.
AS PER DISCUSSION WITH NEIGHBORS...TEMPS MAY NOT QUITE MAKE IT TO
FREEZING TONIGHT...BUT WILL BE CLOSE ENOUGH SO A WATCH IS
INDICATED TO HIGHLIGHT THE POSSIBILITY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 248 AM EDT SUN APR 22 2012
LATEST INITIALIZATION IS SHOWING LIKELY POPS ACROSS MOST OF FORECAST
AREA ON WEDNESDAY AS SURFACE LOW AND ASSOCIATED FRONT MOVE ACROSS
CENTRAL INDIANA. HOWEVER...PRECIP WILL QUICKLY EXIT THE AREA BY
THURSDAY MORNING AS FRONT MOVES SOUTH AND ISENTROPIC LIFT
DECREASES. MODELS ARE IN LINE WITH THAT FORECAST...SO WILL NOT
DEVIATE FROM INITIALIZATION.
HIGH PRESSURE WILL QUICKLY BUILD INTO CENTRAL INDIANA ON
THURSDAY...BRINGING DRY CONDITIONS UNTIL SATURDAY. AFTER
THAT...MODELS EJECT ANOTHER LOW OUT OF THE CENTRAL PLAINS ON SUNDAY
MORNING...BUT THERE IS TOO MUCH UNCERTAINTY AT THIS TIME TO MAKE ANY
ADJUSTMENTS TO DAY 7.
TEMPS WILL BE KIND OF COOL...BUT WHAT IS ACTUALLY NORMAL FOR THIS
TIME OF YEAR. INITIALIZATION IS HANDLING THE PATTERN WELL...SO NO
DEVIATIONS.
&&
.AVIATION /DISCUSSION FOR THE 22/1200Z TAF ISSUANCE/...
ISSUED AT 1022 AM EDT SUN APR 22 2012
1030Z UPDATE...FEW UPDATES TO TAFS TO ACCOUNT FOR LATEST TRENDS.
BELIEVE THE GUSTIER WINDS WILL NOT ARRIVE UNTIL CLOSER TO 18Z THIS
AFTERNOON...THOUGH THEY WILL PICK UP TO 10-12 KT IN THE NEXT HOUR
OR TWO AND MAY GUST AROUND 20 KT BEFORE THEN. THIS WAS ACCOUNTED
FOR IN THE TAFS. MADE SOME MINOR ADJUSTMENTS TO SKY COVER. KIND
AND A FEW OTHER NON-FORECAST SITES ARE REPORTING SOME MVFR CEILINGS
AROUND 3K FT. THIS SHOULD BE BRIEF AND WILL LIFT/MIX OUT IN THE
NEXT HR OR SO.
PREVIOUS DISCUSSION FOLLOWS...
ISSUED AT 733 AM EDT SUN APR 22 2012
THE TAF PERIOD WILL START OUT WITH SCATTERED TO BROKEN MID LEVEL
CLOUD DECKS...AND GRADUALLY CLEAR OUT BY TONIGHT. SO...VFR
CONDITIONS WILL BE THE PREVAILING FLIGHT CATEGORY FOR DURATION OF
TAF PERIOD. THE MAIN THREAT THOUGH WILL BE THE STRONG WINDS. THE
CURRENT EASTERLY WINDS WILL BACK TO THE NORTHEAST BY MID MORNING
AND INCREASE TO SUSTAINED SPEEDS OF 12 TO 14 KTS WITH GUSTS UP TO
25 KTS FOR THE REMAINDER OF THE DAY. GUSTS WILL TAPER OFF THIS
EVENING...BUT WINDS WILL RETAIN THEIR NORTHERLY COMPONENT AND
REMAIN BREEZY THROUGH THE NIGHT. TOMORROW MORNING...NORTH WINDS
WILL INCREASE ONCE AGAIN WITH GUSTS UP TO 30 KTS AS PRESSURE
GRADIENT TIGHTENS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR INZ021-
028>031-035>049-051>057-060>065-070>072.
&&
$$
SYNOPSIS...JK
NEAR TERM...CP
SHORT TERM...JK
LONG TERM....TDUD
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
636 AM CDT SUN APR 22 2012
.UPDATE...
RADAR TRENDS SHOW A GENERAL DECREASE IN AREAL COVERAGE AND
INTENSITY OF THE PRECIP OVER THE PAST 3 HRS. RUC TRENDS INDICATE
THE SUPPORT HELPING TO GENERATE THE PRECIPITATION WILL DISSIPATE
OVER THE NEXT 3-4 HRS. RECEIVED A SPOTTER REPORT OF SLEET IN JO
DAVIESS COUNTY SHORTLY AFT 09Z. INITIALLY THERE WAS NOTHING
SUPPORTING THIS IN OBS OR RADAR BUT AROUND 0930Z THERE WAS A NOTED
INCREASE IN REFLECTIVITY MOVING INTO CARROLL COUNTY. THUS IT IS
POSSIBLE THE RADAR WAS PARTIALLY OVERSHOOTING THE PRECIPITATION IN
THAT AREA.
PRECIPITATION IN THE NORTHEAST PART OF THE CWFA IS RAPIDLY FALLING
APART AS THE BETTER FORCING/CONVERGENCE SHIFTS TO THE SOUTH AND
WEST. SOME SPRINKLES MAY BE POSSIBLE OVER THE NORTHEAST THIRD TO
40 PERCENT OF THE CWFA SHORTLY AFT 12Z BUT THEY SHOULD DISSIPATE
BY 8 AM.
OVERALL...THE CURRENT FCST STILL LOOKS TO BE ON TRACK WITH NO
UPDATED PLANNED ATTM. ..08..
&&
.AVIATION...
RADAR TRENDS THE PAST SEVERAL HOURS SHOW A GENERAL DECREASE IN
REGARDS TO INTENSITY AND AREAL COVERAGE OF PRECIPITATION. VCSH
WILL BE POSSIBLE AT ALL TAF SITES THROUGH 14Z/22 AS RUC TRENDS
INDICATES THE OVERALL LIFT SUPPORTING SHRA ACTIVITY WILL THEN
DISSIPATE. OTHERWISE EXPECT VFR CONDITIONS THROUGH 06Z/23. IT IS
STILL UNCERTAIN WHETHER MVFR VSBYS CONDITIONS WILL DVLP AFT
06Z/23. AS A RESULT THEY WERE NOT INCLUDED IN THE 12Z TAFS. ..08..
&&
.PREV DISCUSSION... /ISSUED 316 AM CST SUN APR 22 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS WEAK LOWS FROM SOUTHERN MINNESOTA INTO SOUTH
CENTRAL IOWA. AN INVERTED TROF RAN FROM A LOW NEAR KMCW SOUTHEAST TO
KSPI. DEW POINTS WERE IN THE 40S AROUND THE INVERTED TROF WITH 30S
OVER MOST OF THE GREAT LAKES AND NORTHERN PLAINS.
RADAR TRENDS THE PAST SEVERAL HOURS SHOW A GENERAL WEAKENING OF THE
PRECIPITATION WITH MAINLY LIGHT RAIN AND SPRINKLES AROUND THE
INVERTED TROF.
SHORT TERM...TODAY AND TONIGHT
SFC DATA AND RUC TRENDS INDICATE MOST OF THE PRECIPITATION ACROSS
THE CWFA IS ASSOCIATED WITH THE INVERTED TROF. THE RUC DOES HAVE
STRONG FORCING ON THE 295K THETA SFC WHICH APPEARS IS RESPONSIBLE
FOR THE WEAK BAND OF SPRINKLES/-RA TO THE EAST OF THE INVERTED TROF.
RUC TRENDS SHOW THIS FORCING WEAKENING THROUGH SUNRISE AS THE
INVERTED TROF SLOWLY MOVES TO THE SOUTH AND WEST. THUS ANY
PRECIPITATION SHOULD BE CONFINED TO ROUGHLY THE SOUTHWEST HALF OF
THE CWFA AFTER SUNRISE.
THE INVERTED TROF GENERALLY EXITS THE CWFA BY MID MORNING AND THE
OVERALL FORCING/CONVERGENCE WEAKENS FURTHER. THUS MOST IF NOT ALL
THE PRECIPITATION SHOULD BE OVER BEFORE MID DAY. QUIET AND THEN
MAINLY DRY CONDITIONS SHOULD BE SEEN ACROSS THE AREA DURING THE
AFTERNOON.
TONIGHT...QUIET CONDITIONS WILL BE SEEN ACROSS THE CWFA.
INTERESTINGLY...THE HEAVY RAIN AND MCS TOOLS BRING CONVERGENCE AND
HIGHER RH DOWN ACROSS THE AREA. THE RH IS TRACEABLE TO THE LOW AND
MID CLOUDS CURRENTLY ACROSS NORTHERN MINNESOTA. SO...IT IS
CONCEIVABLE THAT A SUBTLE SHORTWAVE TOPPING THE RIDGE MAY BRING DOWN
THESE CLOUDS INTO THE AREA. IF CORRECT...THE CLOUDS SHOULD BREAK UP
SOMEWHAT DUE TO THE SUBSIDENCE OVER THE WESTERN GREAT LAKES IN THE
WAKE OF THE DEVELOPING EAST COAST STORM. ..08..
LONG TERM...MONDAY THROUGH NEXT SATURDAY
MONDAY WE REMAIN IN THE STRONG NORTHWEST FLOW AS THE STORM SYSTEM
OVER THE EAST COAST DEEPENS AND CAUSES THE FLOW TO AMPLIFY STRONGLY
OVER THE CONUS. THIS WILL ACT TO FUNNEL COOLER THAN NORMAL AIR DOWN
INTO THE REGION INTO TUESDAY. THERE IS SOME POTENTIAL FOR SOME
DIURNALLY DRIVEN SHOWERS ON MONDAY AFTERNOON WITH THE SURFACE RIDGE
STILL TO THE WEST AND SOME WEAK CONVERGENCE TO HELP START THEM OFF.
BY TUESDAY THE SURFACE RIDGE WILL HAVE SHIFTED EAST OF THE AREA SO
THIS IS LESS OF A CONCERN AND HAVE PUT IN A DRY FORECAST AND WARMER
TEMPERATURES.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. A SHORTWAVE MOVES OVER THE
TOP OF THE UPPER LEVEL RIDGE TO OUR WEST DROPS DOWN IN THE NORTHWEST
FLOW. THIS...COMBINED WITH THE BAROCLINIC ZONE OVER THE AREA AS A
RESULT OF THE COLD AIR POOL TO OUR EAST SHOULD ACT TO GENERATE SOME
FRONTOGENESIS AS THIS FEATURES MOVES ON BY. TUESDAY NIGHT THE WARM
AIR ADVECTION/ISENTROPIC LIFT SHOWERS SHOULD BE MOVING INTO THE
AREA. THE SURFACE LOW MOVES ACROSS IOWA DURING THE DAY ON
WEDNESDAY...AND WE WILL HAVE THE COLD SIDE OF THE SYSTEM MOVE ACROSS
WEDNESDAY NIGHT. THERE ARE SOME CONCERNS THAT THE BULK OF THIS
SYSTEM WILL AFFECT AREAS NORTHEAST OF THE CWA DEPENDING ON THE
MODEL YOU LOOK AT...SO THE FORECAST IS STILL FOR JUST CHANCE POPS.
TEMPERATURES WITH THIS SYSTEM WILL BE WARMER THAN NORMAL TUESDAY
NIGHT AND WEDNESDAY...WITH COLDER TEMPS FOR WEDNESDAY NIGHT AS THE
TRAILING COLD FRONT MOVES THROUGH. THURSDAY TO BE COLDER AGAIN
BEHIND THE EXITING SYSTEM.
THURSDAY NIGHT THROUGH NEXT SATURDAY...HERE MORE QUESTION MARKS
ENTER THE FORECAST WITH MORE DIFFERENCES IN THE MODELS. THE UPPER
LEVEL RIDGE TO OUR WEST DURING THE MIDDLE OF THE WEAK BECOMES RATHER
PINCHED...AND IT GETS BODILY SHOVED EAST AS A FAIRLY POTENT UPPER
LOW SWINGS ACROSS THE FOUR CORNERS STATES. BY SATURDAY MORNING THE
MODELS ARE PUSHING A WARM AIR ADVECTION WING OF PRECIPITATION INTO
THE FORECAST AREA. WOULD NOT BE TOO SURPRISED TO SEE THIS SLOW DOWN
SOME...THOUGH THE MODELS HAVE BEEN FAIRLY CONSISTENT SO FAR.
LE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1102 AM CDT SUN APR 22 2012
.UPDATE...MAIN ISSUE TODAY IS DISSIPATION RATE OF LARGE STRATUS
CLOUD FIELD LEFT IN WAKE OF DEPARTED SYSTEM. RUC13 85/70H LAYER
IS 90 PERCENT OR MORE OVER MOST OF ARROWHEAD/RANGE/BRD LAKES/TWIN
PORTS REGION. EROSION OF CLOUD DECK SHOULD OCCUR OVER NWRN CWA
SLOWLY TODAY ALTHOUGH INSTABILITY CU MAY REDEVELOP IN AFTERNOON
SUNSHINE. DEEP LAYER MOISTURE SHOULD ADVECT SLOWLY EAST INTO
WISCONSIN BY LATE AFTN. VERY LITTLE FORCING EVIDENT AT THIS TIME
AND 88D RETURNS HAVE BEEN DECREASING WITH TIME THIS MORNING. PTYPE
PLAYING THE BDRY LYR MERRY GO ROUND WITH RAIN/SNOW AT TIMES ACROSS
NRN MN ZONES. WILL KEEP IDEA THAT EVENTUALLY ANYTHING DESCENDING
THIS AFTN FROM THE CLOUDS WILL BE LIQUID.
&&
.PREV DISCUSSION... /ISSUED 625 AM CDT SUN APR 22 2012/
AVIATION...12Z TAFS
LIGHT RAIN OR SNOW CONTINUED OVER WESTERN AND NORTHERN
AREAS...IMPACTING KBRD...AND AREAS JUST NORTH OF KHIB. SOME
LOCALLY VERY DRY LOW LEVEL AIR COVERED THE NORTH SHORE DOWN INTO
KDLH...AND ALLOWED CEILINGS TO REMAIN VFR AND KEEPING ANY PRECIP
AWAY. MVFR CEILINGS WERE OCCURRING FROM KBRD...NORTH AND EAST INTO
FAR NORTHERN MINNESOTA. THESE CEILINGS WILL CONTINUE THIS
MORNING...POSSIBLY OCCURRING AT KHIB/KDLH AS WELL. THE MVFR
CEILINGS WILL RISE THIS AFTERNOON...WITH THE CLOUDS DIMINISHING IN
SPOTS. HOWEVER...SOUNDINGS SUGGEST ANY CLEAR AREAS WILL SEE
CUMULUS DEVELOP WITH HEATING OF THE DAY...WITH CEILINGS FROM
2500-4000FT DEPENDING ON LOW LEVEL MOISTURE.
CLOUDS WILL DIMINISH FURTHER THIS EVENING...THEN INCREASE AGAIN LATE
OVER THE FAR NORTH.
PREV DISCUSSION... /ISSUED 408 AM CDT SUN APR 22 2012/
SHORT TERM...LATEST REGIONAL SURFACE ANALYSIS SHOWS THE DEPARTING
LOW PRESSURE SYSTEM NOW OVER IOWA EARLY THIS MORNING...WITH A
WEAK INVERTED TROUGH EXTENDING NORTH OF THE LOW OVER MINNESOTA TO
NEAR PARK RAPIDS. THERE IS ALSO A RIDGE OF HIGH PRESSURE EXTENDING
FROM NWRN ONTARIO SWWD ACROSS NWRN MN AND THE DAKOTAS...WHICH IS
SLOWLY BUILDING SWRD. HOWEVER WATER VAPOR SATELLITE IMAGERY
SHOWS A SECOND UPPER LEVEL VORTMAX OVER THE BORDER REGION...WHICH
IS PRODUCING ENOUGH LIFT FOR AREAS OF LIGHT PRECIP...MAINLY IN THE
FORM OF SNOW...ACROSS AREAS NORTHWEST OF THE IRON RANGE. FARTHER
SOUTH ACROSS THE BRAINERD LAKES REGION AND SAINT CROIX RIVER
VALLEY...AREAS OF LIGHT RAIN AND DRIZZLE CONTINUE TO FALL.
DUE TO THE WEAK SFC FEATURES COMBINED WITH ABUNDANT LOW LEVEL
MOISTURE...THE NWP MODELS SHOW SOME DIFFERENCES IN HOW THE THESE
AREAS OF PRECIP WILL EVOLVE ACROSS OUR CWA TODAY. HOWEVER THE
GENERALLY PATTERN IS TO GRADUALLY MOVE THE MAIN AXIS OF PRECIP
GRADUALLY EWD...WITH THE PRECIP COVERAGE DECREASING DURING THE
DAY. BY THIS EVENING...MAINLY DRY CONDITIONS ARE EXPECTED AS THE
RIDGE OF HIGH PRESSURE MOVES OVER THE NORTHLAND AND DRIER AIR
SPREADS SEWD ACROSS THE FCST AREA. THE RIDGE WILL REMAIN OVER THE
UPPER MIDWEST ON MONDAY AS A STRONG STORM SYSTEM LIFTS NEWD
ACROSS THE ERN THIRD OF THE COUNTRY. TEMPERATURES WILL MODERATE
TODAY...ALTHOUGH THE CLOUD COVER WILL KEEP TEMPS AT BELOW NORMAL
LEVELS. WARMER TEMPS ARE EXPECTED ON MONDAY AS SKIES BECOME
PARTLY CLOUDY AND WINDS TURN OUT OF A LIGHT WRLY DIRECTION.
LONG TERM...MONDAY NIGHT THROUGH SATURDAY.
AN UPPER LEVEL RIDGE WILL EXTEND NORTH FROM NEW MEXICO INTO THE
MT/SK EARLY IN THE PERIOD...WITH AN UPPER LOW OVER THE EASTERN
GREAT LAKES. THE MODELS ARE IN GOOD AGREEMENT ON THIS. HOWEVER...A
SURFACE LOW OVER THE NORTHERN PLAINS IS HANDLED QUITE DIFFERENTLY
BETWEEN THE GFS/ECMWF. THE GFS IS FASTER AND A BIT DEEPER WITH THE
LOW AND TAKES A FAR DIFFERENT TRACK COMPARED WITH THE ECMWF/GEM.
WE WENT CLOSER TO THE ECMWF. WE HAVE CHANCES FOR RAIN MONDAY NIGHT
INTO WEDNESDAY. A NICE BAROCLINIC ZONE IS ALSO FORECAST TO BE OVER
THE CWA...WITH THE MODELS SHOWING SOME FGEN DURING THIS PERIOD AS
WELL.
AS THE UPPER RIDGE MOVES EAST MID-LATE WEEK...A STRONG SURFACE HIGH
WILL DEVELOP BETWEEN THE UPPER RIDGE AND A TROUGH/LOW OVER QUEBEC/NE
CONUS. THIS HIGH WILL BRING IN SOME DRY AIR FOR THURSDAY THROUGH
FRIDAY NIGHT.
THE UPPER LEVEL RIDGE WILL PASS EAST OF THE REGION OVER THE
WEEKEND...ALLOWING A TROUGH TO BRING A CHANCE FOR PRECIP TO THE
NORTHLAND. THE GFS IS QUICKER BRINGING MOISTURE BACK INTO THE
NORTHLAND...AND WE DELAYED THE ARRIVAL IN THE NORTHEASTERN HALF OF
THE CWA UNTIL SATURDAY NIGHT.
WE EXPECT TEMPS FROM THE UPPER FIFTIES TO UPPER SIXTIES
TUESDAY...EXCEPT COOLER READING AROUND LAKE SUPERIOR...WITH MAINLY
FIFTIES FOR THE REMAINDER OF THE PERIOD. LOWS THURSDAY NIGHT AND
FRIDAY NIGHT COULD BE QUITE COOL WITH THE HIGH CREATING MAINLY CLEAR
SKIES AND LIGHT WINDS.
&&
.POINT TEMPS/POPS...
DLH 45 32 60 39 / 40 10 10 10
INL 51 29 62 36 / 40 10 10 20
BRD 51 32 64 40 / 50 10 0 10
HYR 52 30 62 37 / 30 10 0 10
ASX 49 32 58 36 / 20 10 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1035 AM CDT SUN APR 22 2012
.DISCUSSION...
CHALLENGE THIS MORNING IS FOG...LOW CLOUDS AND TEMPERATURES. WILL
FOLLOW LATEST RUC GUIDANCE...WHICH SEEMS TO BE HANDLING CURRENT
SITUATION THE BEST.
LOW STRATUS DECK ALONG AND SOUTHEAST OF A LINE FROM FARGO TO
FOSSTON TO BAUDETTE WILL ERODE FROM NORTHWEST TO SOUTHEAST LATE
THIS MORNING AND AFTERNOON AS WEST-NORTHWEST WIND INCREASES. SOME
THERMAL CUMULUS RE-DEVELOPMENT IS POSSIBLE ALONG THE CLEARING
EDGE WITH CONVECTIVE TEMPERATURES NEAR FORECAST HIGHS. EXPECT MORE
SUN THAN CLOUDS BY MID TO LATE AFTERNOON. ADJUSTED SKY COVER GRIDS
TO REFLECT THESE TRENDS.
CLOUD COVER HAS DAMPENED TEMPERATURE RECOVERY DESPITE WEAK WARM
AIR ADVECTION...SO ADJUSTED HIGHS DOWNWARD A COUPLE DEGREES ACROSS
PORTIONS OF WEST CENTRAL MN. SOME SPOTS MAY STRUGGLE TO BREAK THE
50 DEGREE MARK IF CLOUD COVER IS SLOWER TO MOVE OUT...BUT MOST OF
THE FORECAST AREA WILL TOP OUT IN THE LOWER TO UPPER 50S.
ADDED PATCHY FOG MENTION UNTIL 18 UTC FOR THE NORTHERN VALLEY FROM
BUXTON TO GRAND FORKS TO ROSEAU. VISIBILITY HAS IMPROVED TO 1/2
MILE OR MORE...SO EXPECT FOG TO FULLY DISSIPATE BY THE NOON HOUR.
&&
.AVIATION...
IFR/MVFR STRATUS DECK ALONG AND EAST OF THE VALLEY SHOULD BEGIN TO
LIFT AND SLOWLY DISSIPATE FROM NORTHWEST TO SOUTHEAST LATER THIS
AFTERNOON AS WEST-NORTHWEST WIND INCREASES. MULTIPLE TAF UPDATES
ARE POSSIBLE AS TIMING OF CEILINGS IS DIFFICULT. FOG AT GFK SHOULD
DISSIPATE BY 17 UTC.
&&
.PREV DISCUSSION... /ISSUED 338 AM CDT SUN APR 22 2012/
SHORT TERM...
TEMPERATURES THROUGHOUT THE PERIOD AND WHAT HAPPENS WITH THE
SYSTEM COMING OUT ON TUESDAY WILL BE THE PRIMARY FORECAST PROBLEMS
FOR THE SHORT TERM.
CONDITIONS WILL BE MUCH MORE QUIET TODAY AND TOMORROW AS
NORTHWESTERLY FLOW ALOFT SETS UP BEHIND THE DEPARTING UPPER LOW
AND AHEAD OF THE RIDGE BUILDING OVER THE ROCKIES. SFC HIGH
PRESSURE WILL STRETCH FROM ONTARIO INTO THE PLAINS TODAY. 850MB
TEMPS IN THE EASTERN CWA WILL STILL BE FAIRLY COOL AND THERE WILL
NOT BE A HUGE AMOUNT OF MIXING UNDER THE LIGHT WINDS. ON THE OTHER
HAND...THERE SHOULD BE A FAIR AMOUNT OF SUNSHINE AND SOME WESTERLY
WINDS START MOVING SOME WARMER AIR INTO THE FAR WESTERN CWA THIS
AFTERNOON. DESPITE THE FAIRLY COLD START AROUND FREEZING...THINK
WE SHOULD STILL SEE ENOUGH WARMING TODAY TO GET INTO THE
50S...WITH SOME 60S POSSIBLE IN THE NORTHWEST.
SFC HIGH PRESSURE WILL MOVE SLOWLY OFF TO THE SOUTHEAST
TONIGHT...WITH THE DEVELOPING LOW OVER SASKATCHEWAN SHIFTING WINDS
BACK TO THE SOUTHWEST BY TOMORROW MORNING. LOWS WILL BE A BIT MORE
MILD OVER ALL BUT THE FAR EASTERN COUNTIES WHICH WILL BE HANGING
ONTO LIGHT WINDS A BIT LONGER. THE WARM AIR ADVECTION WILL
CONTINUE INTO MONDAY...WITH WINDS CONTINUING TO PICK UP OUT OF THE
SOUTH TO SOUTHWEST. WITH THE SOUTHWESTERLY WINDS GIVING US SOME
GOOD MIXING AND 850MB TEMPS GETTING BACK INTO THE TEENS C...ALONG
WITH PLENTY OF SUN THINK THAT MOST LOCATIONS WILL SEE THE 60S ON
MONDAY WITH A FEW SPOTS IN THE WEST REACHING THE 70S.
UPPER HEIGHTS WILL START TO COME DOWN A BIT MONDAY NIGHT AND SFC
LOW PRESSURE STARTS TO MOVE INTO THE NORTHERN PLAINS. THE MODELS
HAVE BEEN REALLY STRUGGLING WITH HOW THEY HANDLE THE POSITION OF
THE SFC LOW INTO TUESDAY. THE NAM AND GFS ARE PRETTY FAR NORTH
WITH THE SYSTEM AND HAVE MUCH OF THE CWA IN THE WARM SECTOR OF THE
SFC LOW. THE ECMWF ON THE OTHER HAND...IS FURTHER SOUTH WITH THE
POSITION OF THE LOW AND HAS MUCH OF THE CWA ON THE COOLER EASTERLY
FLOW. CONFIDENCE IS NOT VERY HIGH...SO KEPT POPS IN THE 20-30
PERCENT RANGE WE HAD GOING FOR TUESDAY AND TUESDAY NIGHT. HIGHS IN
THE SOUTHWESTERN COUNTIES COULD GET UP TO OR EVEN ABOVE 80 IF THE
FURTHER NORTH DOMESTIC MODELS VERIFY...WITH THE ECMWF OF COURSE
MUCH COOLER. INCREASED TUESDAY HIGH TEMPS A BIT IN THE WESTERN
COUNTIES...ALTHOUGH DUE TO THE UNCERTAINTY WITH THE POSITION OF
THE LOW DID NOT GET QUITE AS WARM AS THE GFS AND THE NAM.
LONG TERM...
MODELS HAVE BEEN TRENDING WITH MORE DRIER EASTERLY WINDS FOR
FRIDAY NIGHT...SO LOWERED ALLBLEND POPS IN THE EASTERN COUNTIES.
OTHERWISE NO MAJOR CHANGES. TEMPS WILL COOL BACK TOWARDS SEASONAL
AVERAGES OR SLIGHTLY BELOW.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/JR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
631 AM CDT SUN APR 22 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
300 AM CDT SUN APR 22 2012
MAIN FORECAST CONCERNS ARE ON THE NEXT PRECIPITATION CHANCES FOR
TUESDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED STRONG RIDGING OVER THE WESTERN U.S. BUILDING INTO SOUTHWEST
CANADA...WHILE TROUGHING WAS PRESENT FROM THE WESTERN GREAT LAKES
REGION SOUTH INTO FLORIDA. MAIN FEATURES OF NOTE TRAVERSING THROUGH
THE TROUGH INCLUDE: AN UPPER LOW NEAR FLORIDA...A POTENT SHORTWAVE
OVER SOUTHWEST IOWA...AND ANOTHER SHORTWAVE IN EASTERN NORTH DAKOTA.
THE POTENT SHORTWAVE HAS BEEN RESPONSIBLE FOR MUCH OF THE
PRECIPITATION AFFECTING THE WESTERN PORTION OF THE FORECAST AREA THE
PAST 18 HOURS...AN IN PARTICULAR A LOW TO MID LEVEL FRONTOGENESIS
ZONE AHEAD OF IT. RUC ANALYSIS SHOWED THIS FRONTOGENESIS HAS DROPPED
SOUTH INTO EASTERN IOWA...AND AS SUCH THE SHOWERS HAVE BEEN
WEAKENING OVER THE FORECAST AREA OVERNIGHT. ANOTHER FEATURE ALLOWING
PRECIPITATION TO WEAKEN IS AN AREA OF HIGH PRESSURE OVER NORTHEAST
ONTARIO. EASTERLY WINDS ARE ADVECTING DRIER AIR OUT OF THE HIGH INTO
THE FORECAST AREA...PARTICULARLY WISCONSIN. 00Z GRB SOUNDING HAD A
PRECIPITABLE WATER OF 0.26 INCHES. THE EASTERLY WINDS STOP AT AN
INVERTED TROUGH WHICH EXTENDS FROM JUST WEST OF MINNEAPOLIS SOUTH
INTO SOUTHEAST IOWA. AIRMASS REMAINS SEASONABLY COOL OVER THE AREA
WITH 850MB TEMPS BETWEEN 0 AND -2C PER 00Z RAOB ANALYSIS.
TODAY THROUGH MONDAY...OVER THE NEXT 24 TO 36 HOURS...A FAIRLY DEEP
TROUGH IS GOING TO FORM OVER THE EASTERN THIRD OF THE U.S....IN
RESPONSE TO THE CURRENT POTENT SHORTWAVE IN IOWA PHASING WITH THE
UPPER LOW IN FLORIDA. IN RESPONSE TO THIS PHASING...A STRONG SPRING
STORM WILL FORM OVER THE NORTHEAST. FOR THE FORECAST AREA...PLAN ON
MAINLY QUIET WEATHER AS HIGH PRESSURE OVER NORTHERN ONTARIO SLOWLY
SINKS SOUTH. THERE ARE STILL SOME ISSUES TO DEAL WITH...THOUGH. THE
FIRST OF WHICH IS THE LINGERING PRECIPITATION AND INVERTED TROUGH.
AS TODAY WEARS ON...THE INVERTED TROUGH SHOULD CONTINUE TO WEAKEN...
ESPECIALLY THIS EVENING WHEN THE SHORTWAVE OVER EASTERN NORTH DAKOTA
SLIDES SOUTH OF THE AREA. ISOLATED/SCATTERED SHOWERS SEEM POSSIBLE
TODAY NEAR THE INVERTED TROUGH...AIDED BY FOCUSED LOW LEVEL
CONVERGENCE AND MOISTURE. MAINTAINED SOME 20 PERCENT CHANCES IN THE
VERY FAR WESTERN PORTION OF THE FORECAST AREA THIS MORNING...IN
AGREEMENT WITH THE 22.00Z NAM/GFS AND LATEST HRRR RUNS. FOR THE REST
OF THE FORECAST AREA TODAY...AN INCREASING NORTHEAST FLOW WILL HELP
BRING IN LOW LEVEL DRY AIR. SOME CLEARING IS POSSIBLE...ESPECIALLY
OVER THE SOUTHEAST END OF THE AREA. TONIGHT...ALTHOUGH THE HIGH
PRESSURE AREA IS MOVING IN...THE NORTHWEST FLOW ALOFT SHOULD HELP
CARRY LOW TO MID LEVEL STRATUS SEEN OVER THE DULUTH AREA SOUTH
ACROSS THE FORECAST AREA. THESE CLOUDS SHOULD BE ENOUGH TO PREVENT
TEMPERATURES FROM REACHING A FROST/FREEZE SITUATION. SKIES ARE
EXPECTED TO CLEAR OUT MONDAY MORNING...THEN ANOTHER SURGE OF MID TO
HIGH CLOUDS ENTER THE PICTURE FROM THE NORTH IN THE AFTERNOON. THIS
IS ASSOCIATED WITH A SMALL PORTION OF THE WESTERN UPPER RIDGE THAT
IS PROGGED TO BUILD TOWARDS THE FORECAST AREA. WE WILL FEEL THIS TOO
BY AN INCREASE IN TEMPERATURES. 850MB TEMPS ARE ONLY 0 TO -2C
TODAY...RESULTING IN HIGHS ONLY IN THE MID 50S. HOWEVER...BY 00Z
TUESDAY...THEY CLIMB TO 2-4C...ALLOWING FOR HIGHS IN THE UPPER 50S
TO LOW 60S.
MONDAY NIGHT THROUGH TUESDAY NIGHT...FOCUS TURNS TO A LOW PRESSURE
SYSTEM PROGGED TO DEVELOP OVER SOUTH CENTRAL SASKATCHEWAN AT 00Z
TUESDAY...ON TOP OF THE UPPER RIDGE. VERY GOOD MODEL AGREEMENT
EXISTS THAT THE UPPER RIDGE WILL FLATTEN AND GET PUSHED SOUTH...IN
RESPONSE TO A SHORTWAVE ROUNDING THE RIDGE WHICH IS LOCATED OFF BAJA
CALIFORNIA RIGHT NOW. AS THE RIDGE FLATTENS...THE LOW PRESSURE
SYSTEM GETS SENT SOUTHEASTWARD INTO WESTERN IOWA BY 12Z WEDNESDAY.
WARM ADVECTION IS FORECAST AHEAD OF THE LOW OVER THE FORECAST AREA
DURING THE ENTIRE MONDAY NIGHT THROUGH TUESDAY NIGHT. 850MB TEMPS
RESPOND BY CLIMBING TO 6 TO 12C BY 00Z WEDNESDAY...WARMEST IN THE
FAR WESTERN PORTION OF THE FORECAST AREA. EVEN MORE WARMING IS
POSSIBLE TUESDAY NIGHT. THE BIGGER QUESTION...THOUGH...IS WHEN/IF
PRECIPITATION WILL OCCUR. PRECIPITABLE WATER VALUES START OFF FAIRLY
LOW AT 00Z TUESDAY...NEAR A 0.5 INCH. GOOD AGREEMENT EXISTS THAT
THESE WILL SLOWLY CLIMB TO NEAR AN INCH BY 00Z WEDNESDAY.
STILL...ISENTROPIC LIFT IS NOT ALL THAT IMPRESSIVE...SUGGESTING MUCH
OF THE WARM ADVECTION IS JUST GOING INTO WARMING. LIKELY TO SEE AN
INCREASE IN MID AND HIGH CLOUDS...THOUGH. THESE CLOUDS WILL HELP TO
KEEP TEMPERATURES UP MONDAY NIGHT. WITH A WARMER START TO
TUESDAY...INCREASING 850MB TEMPS AND FILTERED SUN...ANTICIPATING
HIGHS AT LEAST IN THE 60S AND POSSIBLY LOW 70S IN THE FAR WEST. BY
TUESDAY NIGHT...WITH THE LOW APPROACHING...THERE IS SOME SUGGESTION
OF LOW TO MID LEVEL FRONTOGENESIS INCREASING. THEREFORE...CHANCES OF
PRECIPITATION ARE NECESSARY TUESDAY NIGHT. DO NOT HAVE CONFIDENCE AT
THIS TIME TO GO HIGHER THAN 50 PERCENT AS WOULD LIKE TO SEE STRONGER
FORCING SIGNALS. WILL CONTINUE TO MENTION THUNDER WITH A PLUME OF
500-1000 J/KG OF MUCAPE ADVECTING INTO THE FRONTOGENESIS ZONE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
300 AM CDT SUN APR 22 2012
22.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN PRETTY GOOD
AGREEMENT THROUGH THE ENTIRE LONG TERM PERIOD WITH BOTH THE UPPER
LEVEL AND SURFACE PATTERNS. FOR MUCH OF THE LONG TERM PERIOD...THE
FORECAST AREA IS UNDER THE INFLUENCE OF A CANADIAN HIGH PRESSURE
AREA WHICH DROPS DOWN INTO THE WESTERN GREAT LAKES REGION THURSDAY
MORNING. PRIOR TO THEN...THE LOW PRESSURE SYSTEM FROM TUESDAY NIGHT
AND THE FRONTOGENESIS ZONE AHEAD OF IT OVER THE AREA SHOULD REMAIN
MOSTLY IN PLACE ON WEDNESDAY...THEN HEAD OFF TO THE EAST WEDNESDAY
NIGHT. MAINTAINED 20-40 PERCENT CHANCES ON WEDNESDAY...HIGHEST
ALONG/SOUTH OF I-90...THEN JUST A 20 PERCENT CHANCE WEDNESDAY NIGHT
FOR THE DEPARTING PRECIPITATION. DRY AND COOLER CONDITIONS
ANTICIPATED FOR THURSDAY THROUGH FRIDAY WITH THAT CANADIAN HIGH
BUILDING DOWN. WENT TOWARDS THE COLD SIDE OF GUIDANCE FOR LOWS
THURSDAY NIGHT...WHERE FREEZE CONDITIONS SEEM LIKELY ALONG AND
NORTH OF I-94. WILL REALLY HAVE TO WATCH THIS NIGHT TEMPERATURE
WISE...GIVEN DEWPOINTS THAT ARE LIKELY TO DROP INTO THE 20S AND
MAYBE EVEN UPPER TEENS. AN UPPER RIDGE ON THE WEST SIDE OF THE
SURFACE HIGH IS ALSO A FEATURE TO WATCH. RIGHT NOW GOOD AGREEMENT
EXISTS THAT THIS UPPER RIDGE GET PUSHED INTO THE AREA ON SATURDAY
AS TROUGHING DEVELOPS OVER MUCH OF THE WESTERN U.S.. WILL SEE IF
THAT PROGRESSION STAYS...BUT WITH THAT RIDGE MOVING IN MEANS WARM
ADVECTION...AND THEREFORE CHANCES OF SHOWERS AND THUNDERSTORMS
ENTER THE PICTURE. SEEMS LIKE THE BETTER CHANCES FOR RAIN WOULD
COME SATURDAY NIGHT AND SUNDAY AS SHORTWAVES EJECT OUT OF THE
WESTERN TROUGH AND MOVE INTO THE AREA.
&&
.AVIATION...TODAY AND TONIGHT
631 AM CDT SUN APR 22 2012
RATHER QUIET VFR WEATHER PERIOD TODAY/TONIGHT WITH HIGH PRESSURE
SLOWLY BUILDING SOUTH INTO THE AREA. DRIER EAST/NORTHEAST LOW LEVEL
FLOW WILL SLOWLY ERODE THE CLOUDS WITH RISING SCT-BKN CLOUD LAYERS
TODAY. WITH STEEP LOW LEVEL LAPSE RATES AND SOME LINGERING MOISTURE
THIS AFTERNOON...SCT 5K-6K FT CU/STRATO-CU EXPECTED FOR THE LATE
MORNING/ AFTERNOON HOURS. BKN MID CLOUD DECKS WILL COVER THE AREA
THIS EVENING AS SOME MID LEVEL MOISTURE STUCK IN THE WEAK NORTHERLY
FLOW DRIFTS SOUTH ACROSS THE AREA. DEEPER/DRIER AIR PUSHES SOUTH
ACROSS THE AREA LATER TONIGHT AS SOME STRONGER NORTHERLY MID LEVEL
FLOW AND 850-500MB SHORTWAVE RIDGING BUILDS INTO THE UPPER MIDWEST.
DRYING NORTHEAST TO NORTH BOUNDARY LAYER WINDS FLOW PERSISTS
TONIGHT...LIMITING/PREVENTING ANY LATE NIGHT/EARLY MORNING BR INTO
MON MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 AM CDT SUN APR 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
920 AM PDT SUN APR 22 2012
.SHORT TERM DISCUSSION...
STRONG UPPER RIDGE OVER THE AREA WILL SHIFT EAST OVER THE GREAT
BASIN TODAY AND OVER THE ROCKIES ON MONDAY. THIS WILL PROVIDE ONE
MORE DAY OF MUCH ABOVE NORMAL TEMPERATURES FOR NORTH CENTRAL
CALIFORNIA. CLEAR SKIES PREVAIL OVER ALL OF THE AREA THIS MORNING.
TEMPERATURES WERE IN THE MID TO UPPER 70`S AT MOST VALLEY
LOCATIONS...WHICH IS SLIGHTLY WARMER COMPARED TO YESTERDAY AT
THIS TIME. TEMPERATURE FORECAST CHALLENGE FOR TODAY CENTERS AROUND
TIMING OF DELTA BREEZE AND ITS IMPACT ON AFTERNOON HIGH
TEMPERATURES. HRRR AND WRF BRING DELTA BREEZE INTO THE CENTRAL
VALLEY AROUND 4 PM. CURRENT FORECAST HAS MOST VALLEY AREAS
REACHING NEAR 90 DEGS WHICH IS SLIGHTLY COOLER THAN YESTERDAYS
HIGH TEMPERATURES...ALTHOUGH WE ARE RUNNING WARMER VERSUS
YESTERDAY AT THIS TIME. MAY NEED TO ADD A FEW DEGREES TO CURRENT
FORECASTED HIGH TEMPS IF THIS TREND CONTINUES THIS MORNING.
SECOND CHALLENGE WILL BE CONVECTION THIS AFTERNOON INTO EARLY THIS
COMING WEEK. NOT MUCH IN THE WAY OF CONVECTION DEVELOPED YESTERDAY
AND WHAT LITTLE THERE WAS OCCURRED ON THE EAST SIDE OF THE SIERRA.
FEEL CONDITIONS ARE VERY SIMILAR TODAY...NAM SHOWS CONVECTION OVER
THE SRN SIERRA...WRF IS CONVECTION FREE OVER THE SIERRA BUT HAS
SOME ACTIVITY OVER THE COASTAL RANGE AND SHASTA COUNTY...HRRR IS
CONVECTION FREE OVER ALL OF THE CWA. THE WRF DOES SHOW SOME
INCREASE IN ACTIVITY OVER THE COASTAL RANGE COMPARED TO YESTERDAYS
RUNS AND CURRENT FORECAST REFLECTS THIS THINKING. BETTER PRECIP
CHANCES FOR MONDAY AS WEAK SHORT WAVE IN INCREASING SOUTHWEST FLOW
WILL ACT TO TRIGGER ACTIVITY OVER THE SIERRA.
.EXTENDED DISCUSSION (THURSDAY THROUGH SUNDAY)
THERE IS INCREASING CONFIDENCE IN A WET EVENT FOR WEDNESDAY NIGHT
AND THURSDAY. THERE IS ALSO BETTER TIMING FOR A CUTOFF UPPER LOW
OFF OF THE COAST OF SOUTHERN CALIFORNIA MOVING INLAND LATE
WEDNESDAY. THIS IS FOLLOWED BY A STRONGER ELONGATED LOW TO THE
NORTH EXTENDING INLAND AND PHASING WITH THE FIRST LOW ON THURSDAY.
PW LEVELS INITIALLY WILL BE OVER AN INCH AND THEN DROP OFF THROUGH
THE EVENT. DYNAMIC LIFT WILL BE ENHANCED WITH THE AREA BEING IN
THE EXIT REGION OF A 110 KT JET. SNOW LEVELS WILL INITIALLY BE
OVER 8000 FEET THEN DROPPING TO AROUND 6000 FEET BY THURSDAY
AFTERNOON. SNOW LEVELS WILL FALL FURTHER OVERNIGHT THURSDAY BUT
PRECIPITATION SHOULD BE WINDING DOWN BY EARLY FRIDAY MORNING. IT
IS TOO FAR OUT FOR A PRECISE ESTIMATE OF THE TOTAL QPF AT THIS
POINT BUT AN INCH OR TWO OF LIQUID EQUIVALENT IN THE MOUNTAINS
SEEMS REASONABLE.
TEMPERATURES WILL BE UNSEASONABLY COOL ON THURSDAY AND MAY NOT
EXCEED THE LOWER 60S IN SOME VALLEY LOCATIONS. FRIDAY SHOULD WARM
TO JUST A LITTLE BELOW NORMAL WITH LINGERING SHOWERS...MAINLY IN THE
MOUNTAINS. DRIER AND WARMING WEATHER IS EXPECTED NEXT WEEKEND AS
PACIFIC RIDGING EXTENDS EASTWARD. EK
&&
.AVIATION...
GENERALLY VFR CONDITIONS EXPECTED THROUGH SUNDAY AS HIGH PRESSURE
SHIFTS SLOWLY TO THE EAST SUNDAY. SCATTERED CUMULUS ARE POSSIBLE
OVER THE MOUNTAINS SUNDAY AFTERNOON WITH ISOLATED THUNDERSTORMS
POSSIBLE OVER THE COASTAL RANGE AND SHASTA COUNTY MOUNTAINS. WINDS
SHOULD BE GENERALLY LIGHT EXCEPT FOR SOUTHWEST WINDS OVER THE
DELTA INCREASING IN THE AFTERNOON WITH GUSTS TO AROUND 30 KT.
EK/DANG
&&
.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
350 PM EDT SUN APR 22 2012
.SYNOPSIS...
A STRENGTHENING LOW PRESSURE CENTER WILL TRACK ACROSS THE REGION
TONIGHT. A PERIOD OF MODERATE TO HEAVY RAINFALL WILL ACCOMPANY
THIS STORM TONIGHT ACCOMPANIED BY STRONG WINDS ACROSS THE HIGHER
TERRAIN. IN THE WAKE OF THIS STORM...A COOL AND UNSETTLED WEATHER
PATTERN TO REMAIN FOR THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
LOW PRESSURE CENTER WAS OVER THE OUTER BANKS OF NORTH CAROLINA
WITH A CURRENT MSLP OF 995MB. 3HR ISALLOBARIC FALLS OF 6MBS WAS
ANALYZED JUST OFFSHORE OF KNTU WITH A CONTINUED ACTIVE COASTAL
FRONT OVER THE GULF STREAM. IR SATELLITE REPRESENTATION DOES
SUGGEST A BAROCLINIC LEAF WAS EVOLVING AS THE CENTER OF THE UPPER
LOW WAS EXITING THE NORTHERN FLORIDA COAST.
NCEP MODEL SUITE AN INTERNATIONAL GUIDANCE HAVE FINALLY COME INTO
AGREEMENT THAT THE SURFACE LOW WILL TRACK ALONG THE MID ATLANTIC
COAST THEN INLAND ACROSS NJ/PA/NY LATE TONIGHT. IMPRESSIVE THETA-E
ADVECTION /TROWAL/ AND 2-D FGEN WILL TRANSVERSE THE CWA TONIGHT
WITH FORECAST PWATS OF 2-3 STANDARD DEVIATIONS ABOVE NORMAL PER MID
APRIL CLIMATOLOGY. UPSLOPE ENHANCEMENTS ACROSS THE CATSKILLS AND
OUR ADJACENT WESTERN NEW ENGLAND COUNTIES WILL ADD TO THE RAINFALL
FORECAST WITH A GENERAL 1-3 INCHES AND ISOLATED 4 INCH AMOUNTS
STILL EXPECTED. THIS WILL BE ON TOP OF NEARLY 1 INCH OF RAIN THAT
OCCURRED LAST NIGHT WITH EMBEDDED CONVECTIVE ELEMENTS. SO WE WILL
CONTINUE WITH THE FLOOD WATCH FOR THOSE PREDETERMINED COUNTIES
/SEE HYDRO SECTION FOR FURTHER DETAILS/.
WIND POTENTIAL WAS CLOSELY EVALUATED AND COLLABORATED TODAY. THE
FORECAST 925-850MB WINDS AND TRAJECTORIES ARE PROGGED TO BE
BETWEEN 40-50KTS WITH EVEN HIGHER VALUES PER THE HIRES HRRR AND
BUFR PROFILES. IT APPEARS THE HIGHER MAGNITUDES ARE AT ELEVATIONS
AT AND ABOVE 1500 FEET WHERE WE WILL PLACE WIND ADVISORIES AT THIS
TIME.
THE SHOWALTER VALUES LOWERING CLOSE TO 0C OVER PORTIONS OF THE
BERKSHIRES...AND NW CT...AS THE H850-700 FRONTOGENESIS INTENSIFIES
AHEAD OF THE POTENT WAVE. THERE COULD BE A RUMBLE OF THUNDER
AROUND...BUT WE DID NOT INCLUDE IN THE GRIDDED FORECASTS AT THIS
TIME.
AS FOR TEMPERATURES...WE WILL HOLD TEMPERATURES NEARLY STEADY
OVERNIGHT WITH MOST AREAS REMAINING ABOVE FREEZING. THERE COULD BE
A LITTLE SNOW FOR THE HIGHEST TERRAIN OF THE DACKS LATE TONIGHT AS
AGEOSTROPHIC FLOW INCREASES IN THE LOW LEVELS BUT NOT EXPECTING
TOO MUCH ACCUMULATIONS...LESS THAN 1 INCH.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
MONDAY...THE DEEP AND INTENSE SFC CYCLONE GETS CAPTURED BY THE
CLOSED 500MB LOW OVER PENNSYLVANIA BY DAYBREAK. THE STORM GETS STEERED
SOUTHWEST OF THE REGION...WITH THE DRY SLOT QUICKLY BLASTING IN
FROM THE SOUTHEAST. THE DRY SLOT WILL SHUT DOWN THE MODERATE TO
HEAVY PRECIPITATION OVER MOST OF THE REGION. WE ACCOUNTED FOR THE
DRY SLOT WITH LOWER POPS IN THE AFTERNOON. THE POPS WERE REDUCED
TO SLIGHT AND LOW CHANCE VALUES FROM THE HUDSON RIVER VALLEY
EAST...WITH SLIGHTLY HIGHER POPS FOR THE FAVORED UPSLOPE REGIONS.
THE H850 TEMPS RISE TO +6C TO +8C EARLY ON....BUT COLDER AIR
WRAPS IN FROM THE SOUTH AND WEST DURING THE AFTERNOON. THE COLD
ADVECTION WILL LOWER TEMPS AT THAT LEVEL FROM -1C TO +3C FROM SOUTH
TO NORTH. HIGHS WILL BE IN THE 50S TO L60S ACROSS MOST OF THE
REGION...WITH SOME 40S OVER THE SRN DACKS...AND ERN CATSKILLS.
MONDAY NIGHT INTO TUESDAY...THE STORM BECOMES VERTICALLY STACKED
OVER W-CNTRL NY AND NRN PA. SPOKES OF SHORT-WAVE ENERGY WILL WRAP
AROUND THE STORM BRINGING SHOWERS TO THE REGION. THERE COULD BE
SOME SNOW SHOWERS OVER THE HIGHER TERRAIN WEST OF THE HUDSON RIVER
VALLEY MONDAY NIGHT...THOUGH THE HEAVIEST SNOW CHANCES WILL BE
WELL WEST OF THE REGION OVER WRN NY AND PERHAPS DOWNWIND OF LAKE
ONTARIO. MINOR LAKE ENHANCEMENT AS DELTA T/S INCREASE TO GREATER
THAN 13C WITH FAVORABLE WESTERLY FLOW IN THE BOUNDARY LAYER AND
CYCLONIC FLOW ALOFT. AT THIS TIME...WE WILL PLACE LIGHT
ACCUMULATIONS OF SNOW ACROSS NORTHERN HERKIMER AND HAMILTON
COUNTIES. LOWS MONDAY NIGHT WILL BE IN THE U30S TO L40S IN THE
VALLEYS...AND 30S OVER THE MTNS. THE CYCLONIC VORTICITY ADVECTION
ASSOCIATED WITH THE OCCLUDED SYSTEM WILL BRING A CHANCE OF SHOWERS
TO MOST OF THE REGION ON TUESDAY. THE MID LEVEL LAPSE RATES WILL
BE STEEP WITH H500 TEMPS CLOSE TO -26C. LIKELY POPS WERE UTILIZED
FOR THE WRN ZONES...WHERE THE BEST QG LIFT OCCURS WITH THE
DIFFERENTIAL CYCLONIC VORTICITY ADVECTION AND UPSLOPE ENHANCEMENTS...AS
THE CUTOFF SLOWLY MOVES NORTH OF THE BORDER. MAX TEMPS WILL RUN
ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR LATE APRIL.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
HAVE GONE WITH AN HPC/ECMWF SOLUTION.
THE PERIOD LOOKS TO START OFF WITH A TROUGH OVER THE NORTHEASTERN
CONUS THIS TROUGH WILL HOLD TOUGH THROUGH MUCH OF THE PERIOD...BUT
LOOKS TO BEGIN TO LIFT OUT AT THE VERY END OF THE PERIOD.
A CLIPPER TYPE SYSTEM MIGHT BRING SOME ADDITIONAL LIGHTER
PRECIPITATION TO THE REGION THURSDAY. IF THIS SYSTEM WERE TRACK BIT
FURTHER NORTH (IMPLIED BY THE 12Z GFS) TEMPERATURES WOULD WARM...AT
LEAST IN OUR SOUTHERN AREAS AND THERE WOULD BE MIGHT EVEN BE A
THUNDER THREAT. HOWEVER...THE ECMWF AND HPC SOLUTION TRACKS THIS
SYSTEM MAINLY ACROSS SOUTHERN NEW YORK WHICH WOULD KEEP ALL OF OUR
REGION ON THE COOL SIDE OF THE SYSTEM. THIS IS THE SOLUTION WE WENT
FOR. IN FACT...TEMPERATURES COULD BE MARGINALLY COLD ENOUGH FOR SOME
SNOW TO MIX OVER THE NORTHERN MOUNTAINS DURING THE NIGHTTIME HOURS.
AS THIS STORM PULLS AWAY...THE ECMWF INDICATES ANOTHER UPPER LEVEL
CUTOFF LOW TO DUMBBELL DOWN FROM THE GREAT LAKES AND KEEP OUR
WEATHER SOMEWHAT UNSETTLED INTO FRIDAY AS MOVES ACROSS OUR REGION.
SOME SNOW SHOWERS ARE POSSIBLE ACROSS ANY OF THE HIGHER
TERRAIN..MAINLY EARLY AND LATE IN THE DAY.
SATURDAY LOOKS DRY BUT BRISK AS LOW PRESSURE AND ITS UPPER AIR LOW
SUPPORT SHOULD BE INTO THE CANADIAN MARITIMES.
BY SUNDAY...THE LATEST ECMWF HINTS OF ANOTHER DISTURBANCE AND ITS
WARM FRONT TO POSSIBLY BRING SOME PRECIPITATION TO MAINLY OUR
SOUTHERN AREAS. FOR NOW...JUST INTRODUCED SLIGHT CHANCES FOR SHOWERS
ON SUNDAY.
OVERALL...TEMPERATURES LOOK TO RUN ACTUALLY A LITTLE BELOW NORMAL
DURING THIS TIME FRAME. LOOK FOR HIGHS MAINLY IN THE 50S IN THE
VALLEYS EACH DAY...ONLY 40S ACROSS THE HIGHER TERRAIN. OVERNIGHT
LOWS WILL GENERALLY BE IN THE 30S...BUT DOWN INTO THE 20S ACROSS THE
HIGHER ELEVATION ON ALL BUT WED/THU OVERNIGHT.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
A STRENGTHENING LOW WILL HEAD NORTHWARD ALONG THE STALLED BOUNDARY UP
THE EASTERN SEABOARD THROUGH THIS EVENING. WHEN THE LOW REACHES THE
MID ATLANTIC REGION LATER THIS EVENING IT WILL BEGIN TO MOVE
NORTHWESTWARD AS ITS DRAWN IN UNDER THE UPPER LOW THAT WILL HAVE
DEVELOPED DURING THE DAY. THE SYSTEM WILL BECOME VERTICALLY STACKED
OVER CENTRAL PENNSYLVANIA OVERNIGHT. AS THE LOW APPROACHES A
WIDESPREAD RAIN WILL MOVE INTO THE REGION AND WILL COME DOWN HEAVY
AT TIMES ESPECIALLY FROM LATER THIS AFTERNOON THROUGH MUCH OF THE
OVERNIGHT PERIOD. WIDESPREAD MVFR CONDITIONS ARE EXPECTED TO PERSIST
TODAY AND AS THE HEAVIER RAIN MOVES IN IFR CONDITIONS WILL DEVELOP.
NORTH-NORTHEAST WINDS WILL INCREASE AND BECOME GUSTY TONIGHT. AT
KPOU HAVE LOW LEVEL WIND SHEAR BTWN 02Z AND 08Z AS THE STRONG LOW
LEVEL JET MOVES INTO REGION IN ADVANCE OF THE APPROACHING LOW.
.OUTLOOK...
MON...MVFR/IFR. RAIN SHOWERS IN THE MORNING BECOMING SCATTERED IN
THE AFTERNOON WITH CONDITIONS IMPROVING TO MVFR/VFR.
MON NIGHT-FRI...VFR/MVFR WITH CHANCE OF SHOWERS.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS THE NEXT SEVERAL DAYS WITH A SOAKING
MODERATE TO HEAVY RAINFALL TONIGHT.
COOL AND DAMP CONDITIONS WILL CONTINUE INTO THE MID WEEK PERIOD
&&
.HYDROLOGY...
THE LATEST DROUGHT MONITOR HAS OUR FORECAST AREA IN D0-D2. THE
WORST DROUGHT AREA IS OUR SOUTHERN MOST PORTION OF THE HYDRO
SERVICE AREA. ADDITIONAL MODERATE TO HEAVY RAINFALL IS ON THE
WAY...WHICH WILL ALLEVIATE THE DRY CONDITIONS OVER THE PAST
SEVERAL WEEKS. OUR LATEST QPF FORECAST IS BASED ON HPC WITH
OROGRAPHIC ENHANCEMENTS ADDED ALONG THE EAST FACING SLOPES OF THE
CATSKILLS...SRN GREENS...BERKSHIRES...AND LITCHFIELD HILLS. 1 TO 3
INCHES OF RAINFALL IS EXPECTED WITH SOME LOCALLY HIGHER AMOUNTS TO
4 INCHES.
PER THE LATEST NERFC FORECASTS...SEVERAL RIVER POINTS ACROSS OUR
ADJACENT WESTERN NEW ENGLAND COUNTIES ARE EXPECTED TO EXCEED MINOR
FLOOD STAGE. WE WILL CONTINUE TO MONITOR THE CATSKILLS AS SEVERAL
OF THESE RIVER POINTS WILL CLIMB BUT ARE EXPECTED TO REMAIN JUST
BELOW FLOOD STAGE AT THE PRESENT TIME. SO THE FLOOD WATCH FOR
PORTIONS OF THE CATSKILLS...MID HUDSON VALLEY...TACONICS AND
ADJACENT WESTERN NEW ENGLAND WILL REMAIN IN EFFECT OVERNIGHT.
OTHERWISE...ANTECEDENT CONDITIONS ARE VERY DRY...PRECIPITATION
DEFICITS ARE RUNNING 5 TO 10 INCHES BELOW NORMAL ACROSS EASTERN
NEW YORK AND WESTERN NEW ENGLAND. STREAMFLOW CONDITIONS ARE BELOW
NORMAL AND RESERVOIR LEVELS ACROSS THE AREA REMAIN NEAR TO
SLIGHTLY BELOW NORMAL. THE RESERVOIRS WILL PROVIDE STORAGE
CAPACITY FOR THE MAIN STEM RIVERS. THE FORECAST RAINFALL AMOUNTS
ARE EXPECTED TO PRODUCE SIGNIFICANT WITHIN BANK RISES WITH THE
POTENTIAL OF SOME VERY MINOR FLOODING ON A FEW ISOLATED MAIN STEM
RIVER POINTS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM 6 PM EDT THIS EVENING THROUGH MONDAY MORNING
FOR CTZ001-013.
NY...FLOOD WATCH FROM 6 PM EDT THIS EVENING THROUGH MONDAY MORNING
FOR NYZ043-047-053-054-058>061-063>066-084.
MA...FLOOD WATCH FROM 6 PM EDT THIS EVENING THROUGH MONDAY MORNING
FOR MAZ001-025.
VT...FLOOD WATCH FROM 6 PM EDT THIS EVENING THROUGH MONDAY MORNING
FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...HWJIV
AVIATION...11
FIRE WEATHER...BGM
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
134 PM EDT SUN APR 22 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM JUST OFF THE SOUTH CAROLINA COAST WILL INTENSIFY
AS IT MOVES NORTH PASSING THROUGH THE AREA LATE TONIGHT AND MONDAY.
THE LOW WILL THEN DRIFT NORTH INTO NEW YORK AND CANADA AS IT SLOWLY
WEAKENS. ANOTHER LOW PRESSURE SYSTEM FROM THE GREAT PLAINS SHOULD
PASS JUST SOUTH OF THE REGION WEDNESDAY NIGHT AND THURSDAY. A HIGH
PRESSURE SYSTEM FROM CENTRAL CANADA IS EXPECTED TO BUILD INTO THE
AREA FOR THE END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE HEAVY RAIN IS EASING INTO SOUTHERN DELAWARE...WITH MORE HEAVY
RAIN ACROSS SOUTHERN VIRGINIA AND OFF THE NORTH CAROLINA COAST. AS
THE THETA E RICH AIR CONTINUES TO RIDE NORTH AHEAD OF THE BOTTOM
OF THE NEGATIVELY TITLED LONG WAVE TROUGH...HEAVY RAIN WILL
CONTINUE TO MOVE NORTH. THE 1200 UTC NAM IS STILL SHOWING NEARLY
2.5O INCHES OF RAIN FALLING IN THE BASINS OF THE FASTER REACTING
STREAMS OF SOUTHEAST PENNSYLVANIA AND NORTHERN DELAWARE. THIS
NUMBER IS ABOUT WHAT WOULD BE NEEDED TO PUSH SOME OF THE FASTER
RESPONDERS OVER THEIR BANKS. THE FLOOD WATCH WILL REMAIN IN
EFFECT...THOUGH IT COULD BE THAT THE NORTHEAST PART OF THE WATCH
MAY NOT SEE ENOUGH RAIN FOR FLOODING OF SMALL RAIN...BASED ON 1200
UTC NAM AND TRENDS. HOWEVER...THE FLOOD WATCH STAYS AS IT IS NOT
CLEAR THAT A SHIFT IN THE QPF MAXIMUM WOULD NOT PUT THESE
LOCATIONS IN POSITION FOR FLOODING OF STREAM AND CREEKS.
THE WIND FORECAST REMAINS UNCHANGED. THE LATEST HRRR SHOWS THE
BEST GRADIENT AND ASSOCIATED WIND FIELD REACHING SOUTHERN DELAWARE
AND SOUTHERNMOST NEW JERSEY TOWARD 2300 UTC. THE STRONGEST WINDS
SHOULD OCCUR LATE AFTERNOON ACROSS SOUTHERN AREAS...AND EXIT NEW
JERSEY BEFORE 0600 UTC.
WITH THE NORTHEAST LOW LEVEL FLOW...TEMPERATURES PROBABLY DO NOT
RISE ALL THAT MUCH TODAY. THIS THINKING HAS BEEN REFLECTED IN THE
HIGH TEMPERATURE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HEAVY RAINS WILL CONTINUE THIS EVENING...THEN END FROM SOUTH TO
NORTH. THE LOW WILL PASS ACROSS NJ THEN CURVE NW BACK TOWARD THE
POCONOS BY 12Z MON. DRIER AIR WILL WRAP AROUND FROM THE WEST AND
MOVE ACROSS THE SRN HALF OF THE REGION...ENDING THE HEAVY RAINS.
WINDS WILL REMAIN GUSTY...SHIFTING TO WRLY OR SWRLY BEHIND THE
DEPARTING LOW. THE STRONGEST WINDS WILL SUBSIDE AFTER MIDNIGHT...SO
THE WIND ADVISORY HAS BEEN ISSUED UNTIL 400 AM FOR NOW...IT CAN BE
ADJUSTED ON UPCOMING FCSTS. OVERNIGHT LOWS WILL DROP 5 TO 10 DEGREES
FROM SUNDAYS HIGHS...REACHING THE LOW 40S OVER THE SRN POCONOS AND
MID 40S ELSEWHERE.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
THE GFS AND WRF-NMMB INITIALIZATION LOOKED ABOUT EVEN BUT NOT
PERFECT WITH THE TROF IN THE OH AND TN VALLEYS AND GULF COAST, IF
ANYTHING SUGGESTING A SLIGHTLY SLOWER EVOLUTION. CONVERSELY AT
850MB AND 925MB THE GFS LOOKED BETTER THAN THE WRF-NMMB.
AT THE START OF MONDAY MORNING, THE HEAVY RAIN SHOULD BE JUST
ABOUT EXITING IF NOT ALREADY EXITED OUR CWA. THEN INTO TUESDAY WE
ARE STUCK WITH THE METEOROLOGICAL HANGOVER FROM THIS INTENSE
SYSTEM AS IT SLOWLY WEAKENS AND DRIFTS AWAY FROM THE NERN CONUS.
GIVEN THAT THE GFS IS LIKELY TOO FAST WITH THE SFC LOW, IT IS LIKELY
TOO FAST WITH ADVECTING THE COLD AIR IN FROM THE SOUTHWEST ON
MONDAY. SMALL CONSOLATION AS BOTH IT AND THE WRF-NMMB ARE IN SELF
DESTRUCT SUNSHINE MODE WITH THE COLD POOL ALOFT IN PLACE. PTYPE
SHOULD BE RAIN SHOWERS AS WE SHOULD STILL BE TOO WARM IN THE
BOUNDARY LAYER. IT WILL BE A WINDY DAY AND GUSTS WILL LIKELY
EXCEED 30 MPH. THE GFS IS SLIGHTLY MORE ROBUST WITH THE WINDS AND
TAKE US CLOSE TO WIND ADVY CRITERIA. BECAUSE THE GFS IS LIKELY TOO
FAST, WE COMPROMISED ON THE STAT GUIDANCE FOR MAX TEMPS.
WHILE WE WILL LOSE WHAT APPEARS TO BE LIMITED SUN ON MONDAY, THERE
WILL STILL BE SOME SHORT WAVES ROTATING AROUND THE SLOW TO DEPART
CLOSED LOW MONDAY NIGHT. DEEPEST MOISTURE IS NW WHERE WE KEPT
POPS THRU THE NIGHT. BY MONDAY NIGHT SOME SNOW SHOWERS ARE
POSSIBLE NW OVER THE HIGHER TERRAIN. A TOBYHANNA ACCUMULATION
WOULD NOT BE A SHOCKER BY TUESDAY MORNING.
TUESDAY LOOKS TO BE A REPEAT OF MONDAY WITH SLIGHTLY LESS WIND AND A
FEW LESS SHOWERS AROUND. MEASURABLE POPS ARE FORECAST TO BE 20 TO 40
PCT LESS THAN MONDAY AND ANY AMOUNTS SHOULD ALSO BE LIGHTER WITH
HEIGHTS STARTING TO RECOVER ALOFT AND COLDER TEMPERATURES AT
850MB. HERE THE GFS AIR MASS RECOVERY MAY BE A BIT TOO FAST AND WE
COMPROMISED ON THE STAT GUIDANCE IN THE OPPOSITE DIRECTION.
THE WEAKENING TROF AXIS SHOULD CLEAR OUR CWA BY TUESDAY NIGHT, JUST
IN TIME FOR THE NEXT SYSTEM TO START ARRIVING. WE MAINTAINED
CONTINUITY IN THE REST OF THE LONG TERM EMPHASIZING WEDNESDAY NIGHT
AS THE MOST LIKELY PERIOD FOR THE NEXT PCPN SHOT WITH CHILLIER THAN
NORMAL, BUT FAIR WEATHER FOR THE END OF THE WEEK.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
CONDITIONS HAVE BEEN SLOW TO DROP TO (OR STAY) AT MVFR AT KRDG AND
KABE...BUT THIS SHOULD BE TRANSIENT AS THE LOWER INVERSION SHOULD
ENSURE MVFR CONDITIONS THERE SOON. ELSEWHERE...CONDITIONS ARE
TRANSITING FROM IFR TO LIFR (MAINLY DUE TO CEILINGS). ONCE CEILINGS
DROP TO LIFR...THEY WILL STAY THERE THROUGH THE PASSAGE OF THE LOW
LATER TONIGHT.
WINDS WILL START TO BECOME AN ISSUE FOR ALL TERMINALS AFTER 2200 UTC
AND THE SURFACE LOW APPROACHES. FOR MOST LOCATIONS...WIND GUSTS
BETWEEN 25 AND 34 KNOTS ARE EXPECTED (HIGHEST EAST AND LOWEST WEST)
BETWEEN 0000 UTC AND 0600 UTC. THERE IS SOME SPREAD ON JUST WHERE
THE SURFACE LOW PASSES...AND THIS WILL HAVE A SIGNIFICANT IMPACT ON
WIND DIRECTION AFTER 0600 UTC. FORTUNATELY...BY THAT TIME...THE WIND
SPEEDS SHOULD COME DOWN AND NOT BE AS MUCH OF A FACTOR.
AS THE SURFACE LOW PULLS FURTHER INTO PENNSYLVANIA AND NEW YORK
STATE MONDAY MORNING...WINDS SHOULD SHIFT TO SOUTHWEST JUST ABOUT
EVERYWHERE. GUSTS WILL BEGIN AFTER 1500 UTC...AND GUSTS AS HIGH AS
30 KNOTS ARE POSSIBLE AFTER 1700 UTC. CEILINGS WILL START LIFR IN
ALL LOCATION. IMPROVEMENT WILL BE SLOW...AND IFR CONDITIONS ARE
EXPECTED FROM SOUTHWEST TO NORTHEAST DURING THE MORNING. MVFR
CONDITIONS ARE POSSIBLE AFTER 1800 UTC...BUT CONFIDENCE IN THIS IS
LOW.
OUTLOOK...
TUE...VFR CONDITIONS ARE EXPECTED. LOCAL MVFR CONDITIONS ARE
POSSIBLE IN ISOLATED TO SCATTERED SHOWERS...BUT CONFIDENCE IN THIS
IS LOW.
WED...VFR CONDITIONS ARE EXPECTED. MVFR CONDITIONS ARE POSSIBLE
WEDNESDAY NIGHT...ESPECIALLY SOUTH IN POSSIBLE RAIN.
THU...MVFR CONDITIONS ARE POSSIBLE...ESPECIALLY SOUTH IN THE
MORNING. VFR CONDITIONS ARE EXPECTED IN THE AFTERNOON AND AT
NIGHT.
&&
.MARINE...
WINDS AND SEAS SHOULD REMAIN SUB-SCA THIS MORNING...THEN RAMP UP
TO GALES BY LATE AFTERNOON OVER THE WATERS. A GALE WAS ALSO ISSUED
FOR THE NRN DEL BAY...WHERE SOME G40 WILL LIKELY AFFECT SJSN4. THE
GALES CONTINUE OVER THE DEL BAY AND SRN COASTAL WATERS THRU 06Z MON
AND CONTINUE THRU 09Z MON FOR THE NRN 2 COASTAL WATERS ZONES. SCA
FLAGS WILL LIKELY BE ISSUED ONCE THE GALE FLAGS ARE TAKEN DOWN.
OUTLOOK...
WE MIGHT HAVE ANOTHER PERIOD OF GALE FORCE WIND GUSTS ON MONDAY IN
THE WESTERLY FLOW. AIR TEMPERATURES ARE GOING TO BE RELATIVELY HIGH,
SO CONFIDENCE NOT HIGH. AT THE LEAST SMALL CRAFT ADVISORY CRITERIA
WINDS SHOULD PERSIST INTO TUESDAY DAY UNTIL THE LOW PRESSURE SYSTEM
FINALLY DEPARTS FROM THE REGION. WINDS AND SEAS SHOULD BE BELOW
SMALL CRAFT ADVISORY CRITERIA ON WEDNESDAY, BUT DEPENDING UPON HOW
STRONG THAT CLIPPER TYPE LOW PRESSURE SYSTEM IS, WE MIGHT REACH
SMALL CRAFT ADVISORY CRITERIA AGAIN WEDNESDAY NIGHT OR THURSDAY.
&&
.HYDROLOGY...
THE FLOOD WATCH REMAINS IN EFFECT. PCPN AMOUNTS FROM THE COLD
FRONTAL PASSAGE THUNDERSTORMS AVERAGED BETWEEN ONE QUARTER AND
HALF AN INCH.
WHILE WE HAVE BEEN DRY...ALL OF THE INGREDIENTS FOR HEAVY RAIN ARE
COMING TOGETHER FOR MUCH OF THE AREA. THE SOURCE OF THE AIR RIDING
UP THE FRONT OF THE MID LEVEL TROUGH IS THE EASTERN GULF STATES...
AND PRECIPITABLE WATER VALUES APPROACH 1.50 INCHES LATER SUNDAY INTO
SUNDAY NIGHT. THE HIGHEST PRECIPITABLE WATER VALUES ARE SUPERIMPOSED
WITH THE LOW TO MID LEVEL THETA E RIDGE POKING INTO EASTERN
PENNSYLVANIA AND NORTHERN NEW JERSEY DURING ROUGHLY THE SAME TIME.
STORM TOTAL RAINFALL AMOUNTS OF 2 TO 3.5 INCHES OF RAIN ARE
EXPECTED. THE INITIAL SHOT OF HEAVY RAIN AFFECTS SOUTHERN AREAS
DURING THE AFTERNOON. RAINFALL AMOUNTS IN THIS SHOT COULD APPROACH
2.5 INCHES ACROSS PORTIONS OF NORTHERN DELAWARE AND SOUTHEAST
PENNSYLVANIA. THESE QPF NUMBERS PUSH SOME OF THE FLASHIER STREAMS
AND SMALL RIVERS (SUCH AS THE CHRISTINA) ABOVE THEIR BANKS.
THIS IS THE REASON NORTHERN DELAWARE AND MUCH OF SOUTHEAST
PENNSYLVANIA WERE INCLUDED IN THE WATCH.
FARTHER NORTH...WHERE THE RICH THETA RICH AIR PUSHES IN DURING
THE LATE AFTERNOON AND EARLY EVENING...HIGHER QPF VALUES ARE
EXPECTED. IN THESE AREAS...STORM TOTAL RAINFALL VALUES CLOSE TO
3.5 INCHES ARE POSSIBLE IN PLACES IN MORRIS COUNTY. WHILE THIS
MUCH RAIN DOES NOT RESULT IN MAINSTEM RIVER FLOODING...SMALLER
RIVERS AND STREAMS (SUCH AS THOSE IN MORRIS COUNTY) SHOULD RESPOND
QUICKLY TO THESE AMOUNTS. IF CLOSER TO 4 INCHES OF RAIN FALLS IN
THE PASSAIC BASIN...MAINSTEM FLOODING COULD BECOME POSSIBLE.
THE HEAVIEST RAIN TAPERS OFF FROM SOUTHWEST TO NORTHEAST LATE SUNDAY
EVENING INTO EARLY MONDAY MORNING. THE FLOOD WATCH WAS EXTENDED
THROUGH MUCH OF THE NIGHT TO ALLOW FOR THE RAINFALL TO WORK ITS WAY
THROUGH THE SYSTEM.
RUNNING SOME CONTINGENT FORECASTS AND USING SOME MMEFS DATA, THESE
ARE SOME NUMBERS TO WATCH FOR (BASIN-WIDE AVERAGES) FOR POTENTIAL
FLOODING...
QUICK RESPONDERS ACROSS SE PA AND NRN DE...2.25 TO 2.50"
SLOWER RESPONDERS ACROSS SE PA...3.00"
RANCOCAS BASIN...3.00"
RARITAN BASIN...3.75"
PASSAIC BASIN...4.00"
LEHIGH BASIN...4.00+"
POCONOS...4.00+"
&&
.TIDES/COASTAL FLOODING...
WE WILL ISSUE A COASTAL FLOOD ADVISORY FOR THE OCEAN, DELAWARE BAY
AND TIDAL SECTIONS OF THE DELAWARE RIVER FOR TONIGHT`S HIGH TIDE
CYCLE. WHILE THE SURGE GUIDANCE HAS OUR AREA JUST GETTING OR
FALLING A BIT SHORT OF THE NEEDED CRITERIA, OUR LOCAL STUDY PROGRAM
TAKES TIDAL DEPARTURES HALFWAY INTO THE MINOR TIDAL FLOODING
CRITERIA SOUTH WITH LESS DEPARTURES FARTHER NORTH. SO LEAST
CONFIDENCE UP TOWARD NYC, WILL DEPEND UPON HOW QUICKLY WINDS
INCREASE LEADING INTO THE HIGH TIDE CYCLE. THE ADDED COMPLICATION
WILL BE THAT HEAVY RAIN WILL BE ONGOING DURING THE HIGH TIDE CYCLE.
WE ARE GOING TO HOLD OFF ON CHESAPEAKE BAY AS THE HIGHER
ASTRONOMICAL TIDE IS DURING THE DAY ON MONDAY. THE CBOFS
GUIDANCE IS FORECASTING MINOR TIDAL FLOODING, BUT IT TENDS TO RUN A
BIT TOO HIGH.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ067>071.
COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EDT
MONDAY FOR PAZ070-071.
NJ...FLOOD WATCH THROUGH LATE TONIGHT FOR NJZ008>010-012-015.
WIND ADVISORY UNTIL 4 AM EDT MONDAY FOR NJZ012>027.
COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR NJZ012>014-020-022>027.
COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EDT
MONDAY FOR NJZ016>019-021.
DE...FLOOD WATCH THROUGH LATE TONIGHT FOR DEZ001.
WIND ADVISORY UNTIL 4 AM EDT MONDAY FOR DEZ001>004.
COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR DEZ003-004.
COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EDT
MONDAY FOR DEZ001-002.
MD...NONE.
MARINE...GALE WARNING FROM 5 PM THIS AFTERNOON TO 2 AM EDT MONDAY FOR
ANZ430-431-452>455.
GALE WARNING FROM 5 PM THIS AFTERNOON TO 5 AM EDT MONDAY FOR
ANZ450-451.
&&
$$
SYNOPSIS...GIGI/HAYES
NEAR TERM...HAYES
SHORT TERM...O`HARA
LONG TERM...GIGI/HAYES
AVIATION...GIGI/HAYES/O`HARA
MARINE...HAYES/O`HARA
HYDROLOGY...GIGI
TIDES/COASTAL FLOODING...GIGI
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1215 PM EDT SUN APR 22 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM JUST OFF THE SOUTH CAROLINA COAST WILL INTENSIFY
AS IT MOVES NORTH PASSING THROUGH THE AREA LATE TONIGHT AND MONDAY.
THE LOW WILL THEN DRIFT NORTH INTO NEW YORK AND CANADA AS IT SLOWLY
WEAKENS. ANOTHER LOW PRESSURE SYSTEM FROM THE GREAT PLAINS SHOULD
PASS JUST SOUTH OF THE REGION WEDNESDAY NIGHT AND THURSDAY. A HIGH
PRESSURE SYSTEM FROM CENTRAL CANADA IS EXPECTED TO BUILD INTO THE
AREA FOR THE END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE HEAVY RAIN IS EASING INTO SOUTHERN DELAWARE...WITH MORE HEAVY
RAIN ACROSS SOUTHERN VIRGINIA AND OFF THE NORTH CAROLINA COAST. AS
THE THETA E RICH AIR CONTINUES TO RIDE NORTH AHEAD OF THE BOTTOM
OF THE NEGATIVELY TITLED LONG WAVE TROUGH...HEAVY RAIN WILL
CONTINUE TO MOVE NORTH. THE 1200 UTC NAM IS STILL SHOWING NEARLY
2.5O INCHES OF RAIN FALLING IN THE BASINS OF THE FASTER REACTING
STREAMS OF SOUTHEAST PENNSYLVANIA AND NORTHERN DELAWARE. THIS
NUMBER IS ABOUT WHAT WOULD BE NEEDED TO PUSH SOME OF THE FASTER
RESPONDERS OVER THEIR BANKS. THE FLOOD WATCH WILL REMAIN IN
EFFECT...THOUGH IT COULD BE THAT THE NORTHEAST PART OF THE WATCH
MAY NOT SEE ENOUGH RAIN FOR FLOODING OF SMALL RAIN...BASED ON 1200
UTC NAM AND TRENDS. HOWEVER...THE FLOOD WATCH STAYS AS IT IS NOT
CLEAR THAT A SHIFT IN THE QPF MAXIMUM WOULD NOT PUT THESE
LOCATIONS IN POSITION FOR FLOODING OF STREAM AND CREEKS.
THE WIND FORECAST REMAINS UNCHANGED. THE LATEST HRRR SHOWS THE
BEST GRADIENT AND ASSOCIATED WIND FIELD REACHING SOUTHERN DELAWARE
AND SOUTHERNMOST NEW JERSEY TOWARD 2300 UTC. THE STRONGEST WINDS
SHOULD OCCUR LATE AFTERNOON ACROSS SOUTHERN AREAS...AND EXIT NEW
JERSEY BEFORE 0600 UTC.
WITH THE NORTHEAST LOW LEVEL FLOW...TEMPERATURES PROBABLY DO NOT
RISE ALL THAT MUCH TODAY. THIS THINKING HAS BEEN REFLECTED IN THE
HIGH TEMPERATURE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HEAVY RAINS WILL CONTINUE THIS EVENING...THEN END FROM SOUTH TO
NORTH. THE LOW WILL PASS ACROSS NJ THEN CURVE NW BACK TOWARD THE
POCONOS BY 12Z MON. DRIER AIR WILL WRAP AROUND FROM THE WEST AND
MOVE ACROSS THE SRN HALF OF THE REGION...ENDING THE HEAVY RAINS.
WINDS WILL REMAIN GUSTY...SHIFTING TO WRLY OR SWRLY BEHIND THE
DEPARTING LOW. THE STRONGEST WINDS WILL SUBSIDE AFTER MIDNIGHT...SO
THE WIND ADVISORY HAS BEEN ISSUED UNTIL 400 AM FOR NOW...IT CAN BE
ADJUSTED ON UPCOMING FCSTS. OVERNIGHT LOWS WILL DROP 5 TO 10 DEGREES
FROM SUNDAYS HIGHS...REACHING THE LOW 40S OVER THE SRN POCONOS AND
MID 40S ELSEWHERE.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
THE GFS AND WRF-NMMB INITIALIZATION LOOKED ABOUT EVEN BUT NOT
PERFECT WITH THE TROF IN THE OH AND TN VALLEYS AND GULF COAST, IF
ANYTHING SUGGESTING A SLIGHTLY SLOWER EVOLUTION. CONVERSELY AT
850MB AND 925MB THE GFS LOOKED BETTER THAN THE WRF-NMMB.
AT THE START OF MONDAY MORNING, THE HEAVY RAIN SHOULD BE JUST
ABOUT EXITING IF NOT ALREADY EXITED OUR CWA. THEN INTO TUESDAY WE
ARE STUCK WITH THE METEOROLOGICAL HANGOVER FROM THIS INTENSE
SYSTEM AS IT SLOWLY WEAKENS AND DRIFTS AWAY FROM THE NERN CONUS.
GIVEN THAT THE GFS IS LIKELY TOO FAST WITH THE SFC LOW, IT IS LIKELY
TOO FAST WITH ADVECTING THE COLD AIR IN FROM THE SOUTHWEST ON
MONDAY. SMALL CONSOLATION AS BOTH IT AND THE WRF-NMMB ARE IN SELF
DESTRUCT SUNSHINE MODE WITH THE COLD POOL ALOFT IN PLACE. PTYPE
SHOULD BE RAIN SHOWERS AS WE SHOULD STILL BE TOO WARM IN THE
BOUNDARY LAYER. IT WILL BE A WINDY DAY AND GUSTS WILL LIKELY
EXCEED 30 MPH. THE GFS IS SLIGHTLY MORE ROBUST WITH THE WINDS AND
TAKE US CLOSE TO WIND ADVY CRITERIA. BECAUSE THE GFS IS LIKELY TOO
FAST, WE COMPROMISED ON THE STAT GUIDANCE FOR MAX TEMPS.
WHILE WE WILL LOSE WHAT APPEARS TO BE LIMITED SUN ON MONDAY, THERE
WILL STILL BE SOME SHORT WAVES ROTATING AROUND THE SLOW TO DEPART
CLOSED LOW MONDAY NIGHT. DEEPEST MOISTURE IS NW WHERE WE KEPT
POPS THRU THE NIGHT. BY MONDAY NIGHT SOME SNOW SHOWERS ARE
POSSIBLE NW OVER THE HIGHER TERRAIN. A TOBYHANNA ACCUMULATION
WOULD NOT BE A SHOCKER BY TUESDAY MORNING.
TUESDAY LOOKS TO BE A REPEAT OF MONDAY WITH SLIGHTLY LESS WIND AND A
FEW LESS SHOWERS AROUND. MEASURABLE POPS ARE FORECAST TO BE 20 TO 40
PCT LESS THAN MONDAY AND ANY AMOUNTS SHOULD ALSO BE LIGHTER WITH
HEIGHTS STARTING TO RECOVER ALOFT AND COLDER TEMPERATURES AT
850MB. HERE THE GFS AIR MASS RECOVERY MAY BE A BIT TOO FAST AND WE
COMPROMISED ON THE STAT GUIDANCE IN THE OPPOSITE DIRECTION.
THE WEAKENING TROF AXIS SHOULD CLEAR OUR CWA BY TUESDAY NIGHT, JUST
IN TIME FOR THE NEXT SYSTEM TO START ARRIVING. WE MAINTAINED
CONTINUITY IN THE REST OF THE LONG TERM EMPHASIZING WEDNESDAY NIGHT
AS THE MOST LIKELY PERIOD FOR THE NEXT PCPN SHOT WITH CHILLIER THAN
NORMAL, BUT FAIR WEATHER FOR THE END OF THE WEEK.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
CONDITIONS ARE DROPPING TO MVFR (AFTER A COUPLE OF HOURS OF VFR
CEILINGS). THE STEADIER RAIN IS ABOUT TO MOVE INTO THE KPHL METRO
AREA AIRPORTS. BASED ON UPSTREAM OBSERVATIONS...IT SHOULD TAKE
ABOUT 2 HOURS AFTER THE ONSET OF STEADY RAIN TO DROP VISIBILITY
VALUES TO MVFR.
AGAIN...BASED ON THE TRENDS TO THE SOUTH...CEILINGS SHOULD DROP
TO IFR AFTER 1800 UTC...PROBABLY REACHING KPHL AFTER 1900 UTC.
ONCE CONDITIONS DROP TO IFR...THEY WILL LIKELY STAY IN THAT
CATEGORY FOR THE REST OF TONIGHT AND MUCH OF TONIGHT.
WINDS WILL START TO BECOME AN ISSUE AFTER 2100 UTC. GUSTS OVER 25
KNOTS PROBABLY BEGIN AFTER 1900 UTC...AND WITH GUSTS TO 35 KNOTS
AT KACY AND KMIV POSSIBLY AFTER 2300 UTC. AT THIS TIME...IT
APPEARS AS THOUGH THE STRONGEST WINDS GUSTS AFFECT KACY AND KMIV
BETWEEN 2300 UTC AND 0300 UTC.
OUTLOOK...
MON...IFR CONDITIONS EARLY IN THE MORNING..IMPROVING TO MVFR AND
VFR BY THE AFTERNOON. SW TO W WINDS COULD GUST TO 30 KNOTS...ESPECIALLY
DURING THE AFTERNOON AND EVENING.
TUE...VFR CONDITIONS ARE EXPECTED. LOCAL MVFR CONDITIONS ARE
POSSIBLE IN ISOLATED TO SCATTERED SHOWERS...BUT CONFIDENCE IN THIS
IS LOW.
WED...VFR CONDITIONS ARE EXPECTED. MVFR CONDITIONS ARE POSSIBLE
WEDNESDAY NIGHT...ESPECIALLY SOUTH IN POSSIBLE RAIN.
THU...MVFR CONDITIONS ARE POSSIBLE...ESPECIALLY SOUTH IN THE
MORNING. VFR CONDITIONS ARE EXPECTED IN THE AFTERNOON AND AT
NIGHT.
&&
.MARINE...
WINDS AND SEAS SHOULD REMAIN SUB-SCA THIS MORNING...THEN RAMP UP
TO GALES BY LATE AFTERNOON OVER THE WATERS. A GALE WAS ALSO ISSUED
FOR THE NRN DEL BAY...WHERE SOME G40 WILL LIKELY AFFECT SJSN4. THE
GALES CONTINUE OVER THE DEL BAY AND SRN COASTAL WATERS THRU 06Z MON
AND CONTINUE THRU 09Z MON FOR THE NRN 2 COASTAL WATERS ZONES. SCA
FLAGS WILL LIKELY BE ISSUED ONCE THE GALE FLAGS ARE TAKEN DOWN.
OUTLOOK...
WE MIGHT HAVE ANOTHER PERIOD OF GALE FORCE WIND GUSTS ON MONDAY IN
THE WESTERLY FLOW. AIR TEMPERATURES ARE GOING TO BE RELATIVELY HIGH,
SO CONFIDENCE NOT HIGH. AT THE LEAST SMALL CRAFT ADVISORY CRITERIA
WINDS SHOULD PERSIST INTO TUESDAY DAY UNTIL THE LOW PRESSURE SYSTEM
FINALLY DEPARTS FROM THE REGION. WINDS AND SEAS SHOULD BE BELOW
SMALL CRAFT ADVISORY CRITERIA ON WEDNESDAY, BUT DEPENDING UPON HOW
STRONG THAT CLIPPER TYPE LOW PRESSURE SYSTEM IS, WE MIGHT REACH
SMALL CRAFT ADVISORY CRITERIA AGAIN WEDNESDAY NIGHT OR THURSDAY.
&&
.HYDROLOGY...
THE FLOOD WATCH REMAINS IN EFFECT. PCPN AMOUNTS FROM THE COLD
FRONTAL PASSAGE THUNDERSTORMS AVERAGED BETWEEN ONE QUARTER AND
HALF AN INCH.
WHILE WE HAVE BEEN DRY...ALL OF THE INGREDIENTS FOR HEAVY RAIN ARE
COMING TOGETHER FOR MUCH OF THE AREA. THE SOURCE OF THE AIR RIDING
UP THE FRONT OF THE MID LEVEL TROUGH IS THE EASTERN GULF STATES...
AND PRECIPITABLE WATER VALUES APPROACH 1.50 INCHES LATER SUNDAY INTO
SUNDAY NIGHT. THE HIGHEST PRECIPITABLE WATER VALUES ARE SUPERIMPOSED
WITH THE LOW TO MID LEVEL THETA E RIDGE POKING INTO EASTERN
PENNSYLVANIA AND NORTHERN NEW JERSEY DURING ROUGHLY THE SAME TIME.
STORM TOTAL RAINFALL AMOUNTS OF 2 TO 3.5 INCHES OF RAIN ARE
EXPECTED. THE INITIAL SHOT OF HEAVY RAIN AFFECTS SOUTHERN AREAS
DURING THE AFTERNOON. RAINFALL AMOUNTS IN THIS SHOT COULD APPROACH
2.5 INCHES ACROSS PORTIONS OF NORTHERN DELAWARE AND SOUTHEAST
PENNSYLVANIA. THESE QPF NUMBERS PUSH SOME OF THE FLASHIER STREAMS
AND SMALL RIVERS (SUCH AS THE CHRISTINA) ABOVE THEIR BANKS.
THIS IS THE REASON NORTHERN DELAWARE AND MUCH OF SOUTHEAST
PENNSYLVANIA WERE INCLUDED IN THE WATCH.
FARTHER NORTH...WHERE THE RICH THETA RICH AIR PUSHES IN DURING
THE LATE AFTERNOON AND EARLY EVENING...HIGHER QPF VALUES ARE
EXPECTED. IN THESE AREAS...STORM TOTAL RAINFALL VALUES CLOSE TO
3.5 INCHES ARE POSSIBLE IN PLACES IN MORRIS COUNTY. WHILE THIS
MUCH RAIN DOES NOT RESULT IN MAINSTEM RIVER FLOODING...SMALLER
RIVERS AND STREAMS (SUCH AS THOSE IN MORRIS COUNTY) SHOULD RESPOND
QUICKLY TO THESE AMOUNTS. IF CLOSER TO 4 INCHES OF RAIN FALLS IN
THE PASSAIC BASIN...MAINSTEM FLOODING COULD BECOME POSSIBLE.
THE HEAVIEST RAIN TAPERS OFF FROM SOUTHWEST TO NORTHEAST LATE SUNDAY
EVENING INTO EARLY MONDAY MORNING. THE FLOOD WATCH WAS EXTENDED
THROUGH MUCH OF THE NIGHT TO ALLOW FOR THE RAINFALL TO WORK ITS WAY
THROUGH THE SYSTEM.
RUNNING SOME CONTINGENT FORECASTS AND USING SOME MMEFS DATA, THESE
ARE SOME NUMBERS TO WATCH FOR (BASIN-WIDE AVERAGES) FOR POTENTIAL
FLOODING...
QUICK RESPONDERS ACROSS SE PA AND NRN DE...2.25 TO 2.50"
SLOWER RESPONDERS ACROSS SE PA...3.00"
RANCOCAS BASIN...3.00"
RARITAN BASIN...3.75"
PASSAIC BASIN...4.00"
LEHIGH BASIN...4.00+"
POCONOS...4.00+"
&&
.TIDES/COASTAL FLOODING...
WE WILL ISSUE A COASTAL FLOOD ADVISORY FOR THE OCEAN, DELAWARE BAY
AND TIDAL SECTIONS OF THE DELAWARE RIVER FOR TONIGHT`S HIGH TIDE
CYCLE. WHILE THE SURGE GUIDANCE HAS OUR AREA JUST GETTING OR
FALLING A BIT SHORT OF THE NEEDED CRITERIA, OUR LOCAL STUDY PROGRAM
TAKES TIDAL DEPARTURES HALFWAY INTO THE MINOR TIDAL FLOODING
CRITERIA SOUTH WITH LESS DEPARTURES FARTHER NORTH. SO LEAST
CONFIDENCE UP TOWARD NYC, WILL DEPEND UPON HOW QUICKLY WINDS
INCREASE LEADING INTO THE HIGH TIDE CYCLE. THE ADDED COMPLICATION
WILL BE THAT HEAVY RAIN WILL BE ONGOING DURING THE HIGH TIDE CYCLE.
WE ARE GOING TO HOLD OFF ON CHESAPEAKE BAY AS THE HIGHER
ASTRONOMICAL TIDE IS DURING THE DAY ON MONDAY. THE CBOFS
GUIDANCE IS FORECASTING MINOR TIDAL FLOODING, BUT IT TENDS TO RUN A
BIT TOO HIGH.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FLOOD WATCH THROUGH LATE TONIGHT FOR PAZ067>071.
COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EDT
MONDAY FOR PAZ070-071.
NJ...FLOOD WATCH THROUGH LATE TONIGHT FOR NJZ008>010-012-015.
WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM EDT MONDAY FOR
NJZ012>027.
COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR NJZ012>014-020-022>027.
COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EDT
MONDAY FOR NJZ016>019-021.
DE...FLOOD WATCH THROUGH LATE TONIGHT FOR DEZ001.
WIND ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM EDT MONDAY FOR
DEZ001>004.
COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR DEZ003-004.
COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EDT
MONDAY FOR DEZ001-002.
MD...NONE.
MARINE...GALE WARNING FROM 5 PM THIS AFTERNOON TO 2 AM EDT MONDAY FOR
ANZ430-431-452>455.
GALE WARNING FROM 5 PM THIS AFTERNOON TO 5 AM EDT MONDAY FOR
ANZ450-451.
&&
$$
SYNOPSIS...GIGI/HAYES
NEAR TERM...HAYES
SHORT TERM...O`HARA
LONG TERM...GIGI/HAYES
AVIATION...GIGI/HAYES/O`HARA
MARINE...HAYES/O`HARA
HYDROLOGY...GIGI
TIDES/COASTAL FLOODING...GIGI
AREA FORECAST DISCUSSION
NWS MIAMI FL
649 PM EDT SUN APR 22 2012
.UPDATE...WINDS HAVE SUBSIDED SO THE WIND ADVISORY WAS CANCELLED.
JUST A FEW SMALL SHOWERS NEAR LAKE OKEECHOBEE. WILL UPDATE
FORECAST SOON TO TAKE OUT MENTION OF SHOWERS AS COOLER AND DRIER
AIR WILL CONTINUE TO MOVE INTO SOUTH FL TONIGHT. FOR ADDITIONAL
FORECAST DETAILS, SEE PREVIOUS DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 307 PM EDT SUN APR 22 2012/
DISCUSSION...
COLD FRONT MOVING THROUGH SOUTH FLORIDA THIS AFTERNOON. ALMOST ALL
SHOWERS THAT MOVED ACROSS THE REGION PRODUCED GUSTS OF 35-45
MPH...WITH ONE LONE THUNDERSTORM PRODUCING WINDS TO 54 MPH AT
KFXE. ONLY A FEW LINGERING SHOWERS WERE ACROSS THE EAST COAST
METRO AREAS AND THESE SHOULD END OVER THE NEXT HOUR OR TWO. STRONG
WESTERLY WINDS WILL CONTINUE...HOWEVER...ACROSS BROWARD...MIAMI
DADE...MAINLAND MONROE AND COASTAL COLLIER COUNTIES AND FREQUENT
GUSTS TO 40 MPH ARE EXPECTED THROUGH EARLY THIS EVENING. SO THE
WIND ADVISORY WILL REMAIN IN EFFECT THROUGH 8 PM THIS EVENING.
WATER VAPOR AND RUC ANALYSIS THIS AFTERNOON SHOWED SURFACE HIGH
PRESSURE NEAR THE NORTH CAROLINA COAST RACING OFF TO THE
NORTHEAST. AN UPPER LEVEL TROUGH AND CUTOFF UPPER LOW WERE DIGGING
SOUTHEAST ACROSS KENTUCKY THIS AFTERNOON. DRIER AIR IS EXPECTED TO
BEGIN FILTERING INTO THE REGION STARTING AROUND MIDNIGHT BEHIND
THE FRONT...WITH PWATS FALLING BELOW 0.75 INCHES. BREEZY
CONDITIONS WILL CONTINUE THROUGH THE EVENING FOR MUCH OF THE
REGION AND INTO THE OVERNIGHT HOURS FOR AREAS ALONG THE COAST.
COOLER CONDITIONS ARE EXPECTED TONIGHT WITH LOWS IN THE 50S AROUND
THE LAKE TO THE LOW TO MID 60S FOR THE EAST COAST METRO AREAS.
A SECONDARY SURGE OF DRIER AND COOLER AIR IS EXPECTED ON MONDAY AS
THE STRONG TROUGH OF LOW PRESSURE DIGS INTO THE SOUTHEAST AND
FLORIDA. THIS WILL INCREASE THE WINDS ACROSS THE REGION MONDAY
AFTERNOON...AND BREEZY TO WINDY CONDITIONS CAN BE EXPECTED...
ESPECIALLY TOWARDS THE GULF COAST. TEMPERATURES ON MONDAY WILL
RISE INTO THE UPPER 70S TO LOWER 80S.
MUCH COOLER AND EVEN DRIER AIR WILL BEGIN TO FILTER INTO THE
REGION...WITH PWATS FALLING BELOW 0.5 INCHES BY TUESDAY MORNING.
LOWS AND HIGHS TUESDAY THROUGH WEDNESDAY ARE EXPECTED TO BE 7-12
DEGREES BELOW NORMAL. 1000-850MB THICKNESS VALUES TUESDAY MORNING
ARE EXPECTED TO BE AROUND 1340M. SO TEMPERATURES MAY FALL INTO THE
MID/UPPER 40S NEAR THE LAKE...NEAR 50 ACROSS THE REST OF THE
INTERIOR...AND 50S TO AROUND 60 FOR THE EAST COAST METRO AREAS.
HIGHS ON TUESDAY ARE EXPECTED TO ONLY GET INTO THE LOW TO MID 70S
ACROSS THE REGION. FOR WEDNESDAY MORNING...ALTHOUGH THICKNESS
VALUES WILL INCREASE...DEWPOINTS TUESDAY AFTERNOON ARE EXPECTED TO
DROP INTO THE 30S ACROSS THE REGION. HIGH PRESSURE IS ALSO
EXPECTED TO MOVE DIRECTLY OVERHEAD. SO WITH LIGHT WINDS AND
EXCELLENT RADIATIONAL COOLING...TEMPERATURES WILL GET NEAR THE
SAME OR EVEN COLDER THAN TUESDAY MORNING.
SURFACE HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER
THROUGH THE END OF THE WEEK. TEMPERATURES ARE EXPECTED TO SLOWLY
REBOUND TO NEAR NORMAL.
AVIATION...
SHOWERS STILL LINGER OVER EASTERN PORTIONS OF THE
REGION AS A COLD FRONT PASSES. VCSH IS CARRIED FOR THE EAST COAST
TERMINALS THROUGH 20Z. BRIEF CEILING AND VISIBILITY REDUCTIONS
ARE POSSIBLE IN ANY SHRA. OTHERWISE, WIND SPEEDS REMAIN THE
PRIMARY CONCERN WITH GUSTS OF 25 TO 30 KNOTS POSSIBLE THROUGH AT
LEAST 00Z. PREVAILING VFR EXPECTED THIS EVENING AND OVERNIGHT.
MARINE...
HAZARDOUS MARINE CONDITIONS WILL CONTINUE OVER THE ATLANTIC AND
GULF WATERS THROUGH LATE TONIGHT AND START TO SUBSIDE.
HOWEVER...AS A STRONG UPPER LEVEL TROUGH DIGS INTO THE
SOUTHEAST...A SECONDARY PUSH OF STRONG NORTHWESTERLY WINDS ARE
EXPECTED ACROSS THE LOCAL WATERS LATE MONDAY MORNING THROUGH
MONDAY NIGHT.
FIRE WEATHER...
A VERY DRY AIRMASS SHOULD SPREAD SOUTH WITH RH VALUES FALLING
BELOW 35% FOR SEVERAL HOURS ACROSS A GOOD PORTION OF SOUTH
FLORIDA BY MONDAY AFTERNOON AND ACROSS ALL OF THE AREA ON TUESDAY
AND WEDNESDAY. WINDS WILL INCREASE ON MONDAY AS A SECONDARY SURGE
OF DRIER AIR MOVES ACROSS THE REGION...WITH WINDS ACROSS THE WEST
COAST EXPECTED TO BE ABOVE 15 MPH. HOWEVER...WITH THE RECENT
RAINFALL...ERC VALUES ARE EXPECTED TO REMAIN BELOW 20. SO A FIRE
WEATHER WATCH IS NOT GOING TO BE ISSUED AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 62 81 57 74 / - 0 0 0
FORT LAUDERDALE 64 83 59 76 / - 0 0 0
MIAMI 64 82 59 76 / - 0 0 0
NAPLES 64 81 57 73 / - 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH MONDAY MORNING FOR COASTAL COLLIER.
AM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR COASTAL WATERS
FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-COASTAL
WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM-
WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING
FROM 20 NM TO THE TERRITORIAL WATERS OF THE BAHAMAS-WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20
NM TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR BISCAYNE BAY.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LAKE
OKEECHOBEE.
GM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR COASTAL WATERS
FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM-COASTAL
WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT 20 NM-
GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING
FROM 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
307 PM EDT SUN APR 22 2012
.DISCUSSION...
COLD FRONT MOVING THROUGH SOUTH FLORIDA THIS AFTERNOON. ALMOST ALL
SHOWERS THAT MOVED ACROSS THE REGION PRODUCED GUSTS OF 35-45
MPH...WITH ONE LONE THUNDERSTORM PRODUCING WINDS TO 54 MPH AT
KFXE. ONLY A FEW LINGERING SHOWERS WERE ACROSS THE EAST COAST
METRO AREAS AND THESE SHOULD END OVER THE NEXT HOUR OR TWO. STRONG
WESTERLY WINDS WILL CONTINUE...HOWEVER...ACROSS BROWARD...MIAMI
DADE...MAINLAND MONROE AND COASTAL COLLIER COUNTIES AND FREQUENT
GUSTS TO 40 MPH ARE EXPECTED THROUGH EARLY THIS EVENING. SO THE
WIND ADVISORY WILL REMAIN IN EFFECT THROUGH 8 PM THIS EVENING.
WATER VAPOR AND RUC ANALYSIS THIS AFTERNOON SHOWED SURFACE HIGH
PRESSURE NEAR THE NORTH CAROLINA COAST RACING OFF TO THE
NORTHEAST. AN UPPER LEVEL TROUGH AND CUTOFF UPPER LOW WERE DIGGING
SOUTHEAST ACROSS KENTUCKY THIS AFTERNOON. DRIER AIR IS EXPECTED TO
BEGIN FILTERING INTO THE REGION STARTING AROUND MIDNIGHT BEHIND
THE FRONT...WITH PWATS FALLING BELOW 0.75 INCHES. BREEZY
CONDITIONS WILL CONTINUE THROUGH THE EVENING FOR MUCH OF THE
REGION AND INTO THE OVERNIGHT HOURS FOR AREAS ALONG THE COAST.
COOLER CONDITIONS ARE EXPECTED TONIGHT WITH LOWS IN THE 50S AROUND
THE LAKE TO THE LOW TO MID 60S FOR THE EAST COAST METRO AREAS.
A SECONDARY SURGE OF DRIER AND COOLER AIR IS EXPECTED ON MONDAY AS
THE STRONG TROUGH OF LOW PRESSURE DIGS INTO THE SOUTHEAST AND
FLORIDA. THIS WILL INCREASE THE WINDS ACROSS THE REGION MONDAY
AFTERNOON...AND BREEZY TO WINDY CONDITIONS CAN BE EXPECTED...
ESPECIALLY TOWARDS THE GULF COAST. TEMPERATURES ON MONDAY WILL
RISE INTO THE UPPER 70S TO LOWER 80S.
MUCH COOLER AND EVEN DRIER AIR WILL BEGIN TO FILTER INTO THE
REGION...WITH PWATS FALLING BELOW 0.5 INCHES BY TUESDAY MORNING.
LOWS AND HIGHS TUESDAY THROUGH WEDNESDAY ARE EXPECTED TO BE 7-12
DEGREES BELOW NORMAL. 1000-850MB THICKNESS VALUES TUESDAY MORNING
ARE EXPECTED TO BE AROUND 1340M. SO TEMPERATURES MAY FALL INTO THE
MID/UPPER 40S NEAR THE LAKE...NEAR 50 ACROSS THE REST OF THE
INTERIOR...AND 50S TO AROUND 60 FOR THE EAST COAST METRO AREAS.
HIGHS ON TUESDAY ARE EXPECTED TO ONLY GET INTO THE LOW TO MID 70S
ACROSS THE REGION. FOR WEDNESDAY MORNING...ALTHOUGH THICKNESS
VALUES WILL INCREASE...DEWPOINTS TUESDAY AFTERNOON ARE EXPECTED TO
DROP INTO THE 30S ACROSS THE REGION. HIGH PRESSURE IS ALSO
EXPECTED TO MOVE DIRECTLY OVERHEAD. SO WITH LIGHT WINDS AND
EXCELLENT RADIATIONAL COOLING...TEMPERATURES WILL GET NEAR THE
SAME OR EVEN COLDER THAN TUESDAY MORNING.
SURFACE HIGH PRESSURE WILL REMAIN IN CONTROL OF THE WEATHER
THROUGH THE END OF THE WEEK. TEMPERATURES ARE EXPECTED TO SLOWLY
REBOUND TO NEAR NORMAL.
&&
.AVIATION...
SHOWERS STILL LINGER OVER EASTERN PORTIONS OF THE
REGION AS A COLD FRONT PASSES. VCSH IS CARRIED FOR THE EAST COAST
TERMINALS THROUGH 20Z. BRIEF CEILING AND VISIBILITY REDUCTIONS
ARE POSSIBLE IN ANY SHRA. OTHERWISE, WIND SPEEDS REMAIN THE
PRIMARY CONCERN WITH GUSTS OF 25 TO 30 KNOTS POSSIBLE THROUGH AT
LEAST 00Z. PREVAILING VFR EXPECTED THIS EVENING AND OVERNIGHT.
&&
.MARINE...
HAZARDOUS MARINE CONDITIONS WILL CONTINUE OVER THE ATLANTIC AND
GULF WATERS THROUGH LATE TONIGHT AND START TO SUBSIDE.
HOWEVER...AS A STRONG UPPER LEVEL TROUGH DIGS INTO THE
SOUTHEAST...A SECONDARY PUSH OF STRONG NORTHWESTERLY WINDS ARE
EXPECTED ACROSS THE LOCAL WATERS LATE MONDAY MORNING THROUGH
MONDAY NIGHT.
&&
.FIRE WEATHER...
A VERY DRY AIRMASS SHOULD SPREAD SOUTH WITH RH VALUES FALLING
BELOW 35% FOR SEVERAL HOURS ACROSS A GOOD PORTION OF SOUTH
FLORIDA BY MONDAY AFTERNOON AND ACROSS ALL OF THE AREA ON TUESDAY
AND WEDNESDAY. WINDS WILL INCREASE ON MONDAY AS A SECONDARY SURGE
OF DRIER AIR MOVES ACROSS THE REGION...WITH WINDS ACROSS THE WEST
COAST EXPECTED TO BE ABOVE 15 MPH. HOWEVER...WITH THE RECENT
RAINFALL...ERC VALUES ARE EXPECTED TO REMAIN BELOW 20. SO A FIRE
WEATHER WATCH IS NOT GOING TO BE ISSUED AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 62 81 57 74 / - 0 0 0
FORT LAUDERDALE 64 83 59 76 / - 0 0 0
MIAMI 64 82 59 76 / - 0 0 0
NAPLES 64 81 57 73 / - 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR COASTAL BROWARD-
COASTAL COLLIER-COASTAL MIAMI DADE-FAR SOUTH MIAMI DADE-
INLAND MIAMI DADE-MAINLAND MONROE-METRO BROWARD-METRO MIAMI
DADE.
HIGH RIP CURRENT RISK THROUGH MONDAY MORNING FOR COASTAL COLLIER.
AM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR COASTAL WATERS
FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT 20 NM-COASTAL
WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT MONDAY FOR WATERS FROM
DEERFIELD BEACH TO OCEAN REEF, FL EXTENDING FROM 20 NM TO
THE TERRITORIAL WATERS OF THE BAHAMAS.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR BISCAYNE BAY.
SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR WATERS
FROM JUPITER INLET TO DEERFIELD BEACH, FL EXTENDING FROM 20
NM TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LAKE
OKEECHOBEE.
GM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR COASTAL WATERS
FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM-GULF WATERS
FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING FROM 20 TO
60 NM.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT MONDAY FOR COASTAL WATERS
FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT 20 NM.
&&
$$
DISCUSSION/MARINE/FIRE...84/AK
AVIATION/RADAR...14/MJB
AREA FORECAST DISCUSSION
NWS MIAMI FL
230 PM EDT SUN APR 22 2012
.AVIATION...SHOWERS STILL LINGER OVER EASTERN PORTIONS OF THE
REGION AS A COLD FRONT PASSES. VCSH IS CARRIED FOR THE EAST COAST
TERMINALS THROUGH 20Z. BRIEF CEILING AND VISIBILITY REDUCTIONS
ARE POSSIBLE IN ANY SHRA. OTHERWISE, WIND SPEEDS REMAIN THE
PRIMARY CONCERN WITH GUSTS OF 25 TO 30 KNOTS POSSIBLE THROUGH AT
LEAST 00Z. PREVAILING VFR EXPECTED THIS EVENING AND OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 950 AM EDT SUN APR 22 2012/
UPDATE...
THE 12Z SOUNDING THIS MORNING SHOWED 110 KT UPPER JET STREAK OVER
THE REGION...BUT DRIER AND WARMER AIR ALOFT AND COOLER AIR IN THE
LOW LEVELS. WINDS AROUND 1 KFT WERE 30 KNOTS...SO THE LEFTOVER
SHOWERS THIS MORNING COULD PRODUCE SOME WINDS AROUND 40 MPH. AN
ISOLATED THUNDERSTORM IS POSSIBLE THIS MORNING BUT EXPECT MAINLY
ISOLATED TO SCATTERED SHOWERS BEFORE THE FRONT MOVES THROUGH.
VISIBLE SATELLITE THIS MORNING SHOWED STABLY STRATIFIED AIR OVER
THE NORTHERN GULF. THE SQUALL LINE THAT MOVED ACROSS SOUTH
FLORIDA EARLY THIS MORNING HAD MOVED ACROSS THE BAHAMAS. WATER
VAPOR IMAGERY AND RUC ANALYSIS SHOWED THE UPPER LOW OVER THE
EASTERN GULF AND NORTH FLORIDA LIFTING OUT TO THE NORTHEAST AND
WEAKENING AS A STRONG VORT WAS DIVING DOWN ACROSS THE MIDWEST.
SURFACE LOW PRESSURE OVER THE FAR WESTERN ATLANTIC IS EXPECTED TO
ACCELERATE TO THE NORTHEAST AND BE OFF THE NORTHEAST COAST BY
TONIGHT.
SURFACE ANALYSIS THIS MORNING SHOWED THAT THE COLD FRONT WAS
STILL HANGING BACK OVER THE EASTERN GULF THIS MORNING...JUST TO
THE WEST OF THE NAPLES AREA. THIS FRONT IS EXPECTED TO MOVE
THROUGH THE REGION TODAY...WITH WINDY CONDITIONS THIS AFTERNOON.
GUSTS UP TO 40 MPH ARE POSSIBLE ACROSS BROWARD...MIAMI
DADE...MAINLAND MONROE AND COASTAL COLLIER COUNTY BEHIND THE FRONT
WHERE A WIND ADVISORY IS IN EFFECT FROM 11 AM THROUGH 8 PM THIS
EVENING. WITH EXCELLENT MIXING DUE TO STRONG WESTERLY WINDS AND
WITH AT LEAST DECENT DAYTIME HEATING EXPECTED...SOME LOCATIONS
ALONG THE EAST COAST COULD REACH THE MIDDLE 80S. SO BUMPED UP
TEMPERATURES A COUPLE DEGREES FOR THE EAST COAST METROS TO 84-85
DEGREES.
THERE IS A HIGH RISK OF RIP CURRENTS AT THE GULF COAST BEACHES
TODAY DUE TO THE STRONG WESTERLY FLOW. THERE ALSO MAY BE SOME
MINOR COASTAL FLOODING ALONG THE COLLIER COUNTY COAST AT HIGH TIDE
THIS AFTERNOON AS WATER LEVELS REACH 1-2 FEET ABOVE NORMAL HIGH
TIDE. THE ONLY OTHER CHANGE TO THE GOING FORECAST WAS TO LOWER SKY
COVER THIS MORNING TO ACCOUNT FOR CURRENT CONDITIONS.
PREV DISCUSSION... /ISSUED 803 AM EDT SUN APR 22 2012/
AVIATION...A STRONG COLD FRONT WILL PASS THROUGH THE REGION THIS
MORNING. WIND SPEEDS WILL BE THE PRIMARY CONCERN WITH FREQUENT
GUSTS OF 20 TO 30 KNOTS EXPECTED AFTER 14Z. A FEW SHOWERS WILL
ALSO PROGRESS ACROSS THE AREA, PERHAPS PERSISTING INTO THE
AFTERNOON WITH VCSH ASSIGNED. BRIEF MVFR-IFR CONDITIONS POSSIBLE
IN ANY SHRA, OTHERWISE VFR. WINDS WILL GRADUALLY DECREASE THIS
EVENING, ALTHOUGH WILL REMAIN GUSTY UNTIL AT LEAST 00Z.
PREV DISCUSSION... /ISSUED 620 AM EDT SUN APR 22 2012/
SHORT TERM...
CURRENTLY (07Z)...A SQUALL LINE EXTENDING FROM LAKE OKEECHOBEE
SOUTHWEST TO MAINLAND MONROE MOVING EAST AT 35 MPH. LOCAL
ESTIMATES HAVE THIS LINE REACHING PALM BEACH BEFORE 5 AM AND METRO
AREAS OF BROWARD AND MIAMI-DADE COUNTIES RIGHT ABOUT 5 AM THIS
MORNING. SEVERAL ELEMENTS ALONG THIS LINE SHOW BROAD AND WEAK
CIRCULATION SIGNATURES, BUT MAINLY RADAR ESTIMATES OF 40-50 MPH. A
TORNADO WATCH REMAINS IN EFFECT FOR ALL OF SOUTH FLORIDA AT LEAST
THROUGH 7 AM. AT THAT TIME THE LINE IS EXPECTED TO HAVE MOVE OVER
THE NEAR SHORE ATLANTIC WATERS.
TODAY THROUGH TUESDAY...VIGOROUS SHORT WAVE TROUGH AND ASSOCIATED
SFC LOW/COLD FRONT SHOULD MOVE RAPIDLY EASTWARD AND BE EAST OF THE
PENINSULA BY THIS EVENING WITH SIGNIFICANTLY DRY CONDITIONS BEHIND
IT. A RATHER TIGHT PRESS GRADIENT SHOULD DEVELOP BETWEEN THE SFC
LOW AND A RIDGE BUILDING OVER THE GOM RESULTING IN VERY WINDY
CONDITIONS ACROSS S. FLA THIS AFTERNOON. SOME PORTIONS OF S.
FLA...NAMELY COASTAL COLLIER, MAINLAND MONROE AND METRO AREAS OF
MIAMI-DADE AND BROWARD COULD SEE WIND GUSTS TO 35 MPH OR HIGHER
FROM MID-MORNING THROUGH THIS AFTERNOON. BASED ON THIS...DECIDED TO
ISSUED A WIND ADVISORY FOR THOSE AREAS FROM 15Z TO 24Z TODAY.
THE GULF OF MEX RIDGE SHOULD CONTINUE TO BUILD EAST THROUGH THE
EARLY PART OF NEXT WEEK WITH DRY CONDITIONS CONTINUING. A COOL
AIRMASS SHOULD ALSO SPREAD SOUTH ACROSS THE AREA WITH BOTH MIN/MAX
TEMPS A GOOD 7 TO 10 DEGREES BELOW SEASONAL VALUES.
A STRONG WESTERLY FLOW WILL ALSO RESULT IN VERY ROUGH SURF
CONDITIONS AND HIGH RISK OF RIP CURRENTS ALONG THE SOUTHWEST COAST
BEACHES TODAY.
LONG TERM...WEDNESDAY THROUGH SATURDAY...A DEEP LAYER RIDGE WILL
REMAIN POSITIONED OVER THE REGION KEEPING ANY SIGNIFICANT FEATURE
FROM APPROACHING THE LOCAL AREA AND DRY CONDITIONS PREVAILING
THROUGH THIS PERIOD. ALTHOUGH MILD AND PLEASANT CONDITIONS ARE
EXPECTED WITH SLIGHTLY COOLER THAN SEASONAL TEMPS, A GRADUAL
WARMING TREND SHOULD BEGIN BY MID WEEK WITH MAX AFTERNOON
TEMPS REACHING THE MID 80S BY THE WEEKEND.
MARINE...TIGHTENING OF THE PRESSURE GRADIENT BEHIND THE SFC
LOW/CD FRONT WILL KEEP SFC WINDS WELL ABOVE ADVISORY CRITERIA
ACROSS ALL LOCAL WATERS AT LEAST TONIGHT WITH A GRADUAL
IMPROVEMENT BY MONDAY MORNING.
FIRE WEATHER...A VERY DRY AIRMASS SHOULD SPREAD SOUTH WITH RH
VALUES POSSIBLY FALLING BELOW 35% ACROSS A GOOD PORTION OF SOUTH
FLORIDA BY MONDAY AFTERNOON AND ACROSS ALL OF THE AREA BY TUESDAY.
AT THIS TIME...A FIRE WEATHER WATCH IS NOT BEING CONTEMPLATED AT
THIS TIME...HOWEVER IF THIS TREND CONTINUES A WATCH COULD BE
ISSUED IN FURTHER FORECAST ISSUANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 62 81 57 74 / - 0 0 0
FORT LAUDERDALE 64 83 59 76 / - 0 0 0
MIAMI 64 82 59 76 / - 0 0 0
NAPLES 64 81 57 73 / - 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR COASTAL BROWARD-
COASTAL COLLIER-COASTAL MIAMI DADE-FAR SOUTH MIAMI DADE-
INLAND MIAMI DADE-MAINLAND MONROE-METRO BROWARD-METRO MIAMI
DADE.
HIGH RIP CURRENT RISK THROUGH MONDAY MORNING FOR COASTAL COLLIER.
AM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR BISCAYNE BAY-
COASTAL WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL OUT
20 NM-COASTAL WATERS FROM JUPITER INLET TO DEERFIELD BEACH,
FL OUT 20 NM-WATERS FROM DEERFIELD BEACH TO OCEAN REEF, FL
EXTENDING FROM 20 NM TO THE TERRITORIAL WATERS OF THE
BAHAMAS-WATERS FROM JUPITER INLET TO DEERFIELD BEACH, FL
EXTENDING FROM 20 NM TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LAKE
OKEECHOBEE.
GM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR COASTAL WATERS
FROM CHOKOLOSKEE TO BONITA BEACH, FL OUT 20 NM-COASTAL
WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE, FL OUT 20 NM-
GULF WATERS FROM CHOKOLOSKEE TO BONITA BEACH, FL EXTENDING
FROM 20 TO 60 NM.
&&
$$
AVIATION...14/MJB
AREA FORECAST DISCUSSION...CORRECTED
NWS INDIANAPOLIS IN
116 PM EDT SUN APR 22 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 248 AM EDT SUN APR 22 2012
A STRONG LOW PRESSURE SYSTEM MOVING ALONG THE EAST COAST WILL
DOMINATE INDIANA WEATHER INTO TUESDAY. AT THAT POINT...ANOTHER LOW
PRESSURE SYSTEM TRAVELING FROM THE NORTH PLAINS TO THE OHIO VALLEY
WILL TAKE CHARGE OF HOOSIER WEATHER. FINALLY...A LARGE AREA OF
HIGH PRESSURE WILL MOVE IN THURSDAY AND STICK AROUND INTO THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1046 AM EDT SUN APR 22 2012
DRY FORECAST FOR TODAY STILL LOOKS GOOD WITH ONLY PRECIPITATION
OVER SOUTHERN ILLINOIS CURRENTLY MOVING TO THE SOUTHEAST. INCREASED
PERCENTAGE OF SKY COVER TO BETTER MATCH SATELLITE LOOP BUT THIS
DID NOT RESULT IN ANY CHANGE TO THE ZFP WORDING. HIGH TEMPERATURES
IN THE LOW 50S EAST TO AROUND 60 SOUTHWEST STILL LOOK REASONABLE
AND WITH HRRR GOING WARMER BUT RUC AND SREFS GOING COLDER THINK
LEAVING HIGHS ALONE AT THIS POINT IS THE BEST BET. COULD SEE SOME
WIND GUSTS AROUND 20-25KTS THIS AFTERNOON/EVENING BASED ON
FORECAST SOUNDINGS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 248 AM EDT SUN APR 22 2012
BIGGEST PROBLEM IS IF ANY POPS NEEDED TUESDAY NIGHT.
DONT SEE NEED FOR ANY BEFORE THEN. MAIN MODEL FIELDS CLOSE ON BIG
LOW ALOFT SLOWLY PULLING AWAY. CAN NOT SEE ANYTHING THAT WOULD
JUSTIFY ON AND OFF SLGT CHANCE MET HAS MONDAY NIGHT OR
TUESDAY...SO GOING WITH MAV. PROBABLY MOSTLY CLEAR TOMORROW AND
TOMORROW NIGHT. MAY SEE SOME CLOUDS IN WARM ADVECTION ON TUESDAY.
RETURNING TO TUESDAY NIGHT...LATEST MEX HAS BACKED AWAY FROM
CHANCE POPS IT HAD EARLIER. THIS SEEMS LOGICAL SINCE LARGE RIDGE
SHOULD STILL BE TO OUR WEST. FOR JUST ONE RUN THAT FAR OUT I AM
NOT WILLING TO GO ALL THE WAY FROM CHANCE TO TOTALLY DRY...BUT
WILL CUT BACK TO SLIGHT CHANCE.
GUIDANCE TEMPS VERY CLOSE...WHICH MAKES SENSE CONSIDERING
SIMILARITY OF PARENT MODELS. TO EXTENT THEY DIFFER USING
CONSENSUS TO CAPTURE BEST OF BOTH.
AS PER DISCUSSION WITH NEIGHBORS...TEMPS MAY NOT QUITE MAKE IT TO
FREEZING TONIGHT...BUT WILL BE CLOSE ENOUGH SO A WATCH IS
INDICATED TO HIGHLIGHT THE POSSIBILITY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 248 AM EDT SUN APR 22 2012
LATEST INITIALIZATION IS SHOWING LIKELY POPS ACROSS MOST OF FORECAST
AREA ON WEDNESDAY AS SURFACE LOW AND ASSOCIATED FRONT MOVE ACROSS
CENTRAL INDIANA. HOWEVER...PRECIP WILL QUICKLY EXIT THE AREA BY
THURSDAY MORNING AS FRONT MOVES SOUTH AND ISENTROPIC LIFT
DECREASES. MODELS ARE IN LINE WITH THAT FORECAST...SO WILL NOT
DEVIATE FROM INITIALIZATION.
HIGH PRESSURE WILL QUICKLY BUILD INTO CENTRAL INDIANA ON
THURSDAY...BRINGING DRY CONDITIONS UNTIL SATURDAY. AFTER
THAT...MODELS EJECT ANOTHER LOW OUT OF THE CENTRAL PLAINS ON SUNDAY
MORNING...BUT THERE IS TOO MUCH UNCERTAINTY AT THIS TIME TO MAKE ANY
ADJUSTMENTS TO DAY 7.
TEMPS WILL BE KIND OF COOL...BUT WHAT IS ACTUALLY NORMAL FOR THIS
TIME OF YEAR. INITIALIZATION IS HANDLING THE PATTERN WELL...SO NO
DEVIATIONS.
&&
.AVIATION /DISCUSSION FOR THE 221800Z TAF ISSUANCE/...
ISSUED AT 108 PM EDT SUN APR 22 2012
VFR CONDITIONS FOR THE PERIOD...HOWEVER WINDY AT
TIMES...ESPECIALLY MONDAY.
THIS AFTERNOON CAN BE CHARACTERIZED BY PLENTY OF BKN-OVC
LOW/MID/HIGH LEVEL CLOUD COVER MOVING ACROSS THE STATE. TRIED BEST
TO DEPICT THE MORE PREVALENT CLOUD DECKS...AROUND 5K FT AND 12K
FT...HOWEVER COVERAGE WILL VARY. BY LATE THIS EVENING THE SKIES
CLEAR OUT AND WILL REMAIN CLEAR FOR THE REST OF THE FORECAST
PERIOD. INTEREST THEN TURNS TO WIND FORECAST AS FORMERLY EASTERLY
WINDS HAVE BACKED TO THE NORTH/NORTHEAST AND INCREASED TO
SUSTAINED SPEEDS OF 12 TO 14 KTS WITH GUSTS UP TO 25 KTS FOR THE
REMAINDER OF THE DAY. GUSTS ARE STILL EXPECTED TO TAPER OFF THIS
EVENING...BUT SUSTAINED WINDS WILL REMAIN AROUND 10 KT ALL
LOCATIONS AND THEN PICK BACK UP WITH A TIGHTENING PRESSURE
GRADIENT EARLY TOMORROW MORNING WHERE BETWEEN 15 TO 17Z MANY
SUSTAINED WINDS WILL INCREASE TO 15+ KT WITH GUSTS NEAR 30 KT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR INZ021-
028>031-035>049-051>057-060>065-070>072.
&&
$$
SYNOPSIS...JK
NEAR TERM...CP
SHORT TERM...JK
LONG TERM....TDUD
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
115 PM EDT SUN APR 22 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 248 AM EDT SUN APR 22 2012
A STRONG LOW PRESSURE SYSTEM MOVING ALONG THE EAST COAST WILL
DOMINATE INDIANA WEATHER INTO TUESDAY. AT THAT POINT...ANOTHER LOW
PRESSURE SYSTEM TRAVELING FROM THE NORTH PLAINS TO THE OHIO VALLEY
WILL TAKE CHARGE OF HOOSIER WEATHER. FINALLY...A LARGE AREA OF
HIGH PRESSURE WILL MOVE IN THURSDAY AND STICK AROUND INTO THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1046 AM EDT SUN APR 22 2012
DRY FORECAST FOR TODAY STILL LOOKS GOOD WITH ONLY PRECIPITATION
OVER SOUTHERN ILLINOIS CURRENTLY MOVING TO THE SOUTHEAST. INCREASED
PERCENTAGE OF SKY COVER TO BETTER MATCH SATELLITE LOOP BUT THIS
DID NOT RESULT IN ANY CHANGE TO THE ZFP WORDING. HIGH TEMPERATURES
IN THE LOW 50S EAST TO AROUND 60 SOUTHWEST STILL LOOK REASONABLE
AND WITH HRRR GOING WARMER BUT RUC AND SREFS GOING COLDER THINK
LEAVING HIGHS ALONE AT THIS POINT IS THE BEST BET. COULD SEE SOME
WIND GUSTS AROUND 20-25KTS THIS AFTERNOON/EVENING BASED ON
FORECAST SOUNDINGS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ISSUED AT 248 AM EDT SUN APR 22 2012
BIGGEST PROBLEM IS IF ANY POPS NEEDED TUESDAY NIGHT.
DONT SEE NEED FOR ANY BEFORE THEN. MAIN MODEL FIELDS CLOSE ON BIG
LOW ALOFT SLOWLY PULLING AWAY. CAN NOT SEE ANYTHING THAT WOULD
JUSTIFY ON AND OFF SLGT CHANCE MET HAS MONDAY NIGHT OR
TUESDAY...SO GOING WITH MAV. PROBABLY MOSTLY CLEAR TOMORROW AND
TOMORROW NIGHT. MAY SEE SOME CLOUDS IN WARM ADVECTION ON TUESDAY.
RETURNING TO TUESDAY NIGHT...LATEST MEX HAS BACKED AWAY FROM
CHANCE POPS IT HAD EARLIER. THIS SEEMS LOGICAL SINCE LARGE RIDGE
SHOULD STILL BE TO OUR WEST. FOR JUST ONE RUN THAT FAR OUT I AM
NOT WILLING TO GO ALL THE WAY FROM CHANCE TO TOTALLY DRY...BUT
WILL CUT BACK TO SLIGHT CHANCE.
GUIDANCE TEMPS VERY CLOSE...WHICH MAKES SENSE CONSIDERING
SIMILARITY OF PARENT MODELS. TO EXTENT THEY DIFFER USING
CONSENSUS TO CAPTURE BEST OF BOTH.
AS PER DISCUSSION WITH NEIGHBORS...TEMPS MAY NOT QUITE MAKE IT TO
FREEZING TONIGHT...BUT WILL BE CLOSE ENOUGH SO A WATCH IS
INDICATED TO HIGHLIGHT THE POSSIBILITY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 248 AM EDT SUN APR 22 2012
LATEST INITIALIZATION IS SHOWING LIKELY POPS ACROSS MOST OF FORECAST
AREA ON WEDNESDAY AS SURFACE LOW AND ASSOCIATED FRONT MOVE ACROSS
CENTRAL INDIANA. HOWEVER...PRECIP WILL QUICKLY EXIT THE AREA BY
THURSDAY MORNING AS FRONT MOVES SOUTH AND ISENTROPIC LIFT
DECREASES. MODELS ARE IN LINE WITH THAT FORECAST...SO WILL NOT
DEVIATE FROM INITIALIZATION.
HIGH PRESSURE WILL QUICKLY BUILD INTO CENTRAL INDIANA ON
THURSDAY...BRINGING DRY CONDITIONS UNTIL SATURDAY. AFTER
THAT...MODELS EJECT ANOTHER LOW OUT OF THE CENTRAL PLAINS ON SUNDAY
MORNING...BUT THERE IS TOO MUCH UNCERTAINTY AT THIS TIME TO MAKE ANY
ADJUSTMENTS TO DAY 7.
TEMPS WILL BE KIND OF COOL...BUT WHAT IS ACTUALLY NORMAL FOR THIS
TIME OF YEAR. INITIALIZATION IS HANDLING THE PATTERN WELL...SO NO
DEVIATIONS.
&&
.AVIATION /DISCUSSION FOR THE 221800Z TAF ISSUANCE/...
ISSUED AT 108 PM EDT SUN APR 22 2012
VFR CONDITIONS FOR THE PERIOD...HOWEVER WINDY AT
TIMES...ESPECIALLY MONDAY.
THIS AFTERNOON CAN BE CHARACTERIZED BY PLENTY OF BKN-OVC
LOW/MID/HIGH LEVEL CLUD COVER MOVING ACROSS THE STATE. TRIED BEST
TO DEPICT THE MORE PREVALENT CLOUD DECKS...AROUND 5K FT AND 12K
FT...HOWEVER COVERAGE WILL VARY. BY LATE THIS EVENING THE SKIES
CLEAR OUT AND WILL REMAIN CLEAR FOR THE REST OF THE FORECAST
PERIOD. INTEREST THEN TURNS TO WIND FORECAST AS FORMERLY EASTERLY
WINDS HAVE BACKED TO THE NORTH/NORTHEAST AND INCREASED TO
SUSTAINED SPEEDS OF 12 TO 14 KTS WITH GUSTS UP TO 25 KTS FOR THE
REMAINDER OF THE DAY. GUSTS ARE STILL EXPECTED TO TAPER OFF THIS
EVENING...BUT SUSTAINED WINDS WILL REMAIN AROUND 10 KT ALL
LOCATIONS AND THEN PICK BACK UP WITH A TIGHTENING PRESSURE
GRADIENT EARLY TOMORROW MORNING WHERE BETWEEN 15-17Z MANY
SUSTAINED WINDS WILL INCREASE TO 15+ KT WITH GUSTS NEAR 30 KT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE TONIGHT THROUGH MONDAY MORNING FOR INZ021-
028>031-035>049-051>057-060>065-070>072.
&&
$$
SYNOPSIS...JK
NEAR TERM...CP
SHORT TERM...JK
LONG TERM....TDUD
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1234 PM CDT SUN APR 22 2012
.AVIATION...
CLEAR TO MOSTLY CLEAR CONDITIONS WILL PERSIST ALONG WITH VFR
VISIBILITIES THROUGH AT LEAST 24/00Z. HIGH PRESSURE FROM ONTARIO
WILL BRING COOL AIR INTO THE AREA ON NE WINDS OF 5 TO 15 MPH
THROUGH MONDAY AFTERNOON. NICHOLS
&&
.PREV DISCUSSION... /ISSUED 636 AM CDT SUN APR 22 2012/
UPDATE...
RADAR TRENDS SHOW A GENERAL DECREASE IN AREAL COVERAGE AND
INTENSITY OF THE PRECIP OVER THE PAST 3 HRS. RUC TRENDS INDICATE
THE SUPPORT HELPING TO GENERATE THE PRECIPITATION WILL DISSIPATE
OVER THE NEXT 3-4 HRS. RECEIVED A SPOTTER REPORT OF SLEET IN JO
DAVIESS COUNTY SHORTLY AFT 09Z. INITIALLY THERE WAS NOTHING
SUPPORTING THIS IN OBS OR RADAR BUT AROUND 0930Z THERE WAS A NOTED
INCREASE IN REFLECTIVITY MOVING INTO CARROLL COUNTY. THUS IT IS
POSSIBLE THE RADAR WAS PARTIALLY OVERSHOOTING THE PRECIPITATION IN
THAT AREA.
PRECIPITATION IN THE NORTHEAST PART OF THE CWFA IS RAPIDLY FALLING
APART AS THE BETTER FORCING/CONVERGENCE SHIFTS TO THE SOUTH AND
WEST. SOME SPRINKLES MAY BE POSSIBLE OVER THE NORTHEAST THIRD TO
40 PERCENT OF THE CWFA SHORTLY AFT 12Z BUT THEY SHOULD DISSIPATE
BY 8 AM.
OVERALL...THE CURRENT FCST STILL LOOKS TO BE ON TRACK WITH NO
UPDATED PLANNED ATTM. 08
PREV DISCUSSION... /ISSUED 316 AM CST SUN APR 22 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS WEAK LOWS FROM SOUTHERN MINNESOTA INTO SOUTH
CENTRAL IOWA. AN INVERTED TROF RAN FROM A LOW NEAR KMCW SOUTHEAST TO
KSPI. DEW POINTS WERE IN THE 40S AROUND THE INVERTED TROF WITH 30S
OVER MOST OF THE GREAT LAKES AND NORTHERN PLAINS.
RADAR TRENDS THE PAST SEVERAL HOURS SHOW A GENERAL WEAKENING OF THE
PRECIPITATION WITH MAINLY LIGHT RAIN AND SPRINKLES AROUND THE
INVERTED TROF.
SHORT TERM...TODAY AND TONIGHT
SFC DATA AND RUC TRENDS INDICATE MOST OF THE PRECIPITATION ACROSS
THE CWFA IS ASSOCIATED WITH THE INVERTED TROF. THE RUC DOES HAVE
STRONG FORCING ON THE 295K THETA SFC WHICH APPEARS IS RESPONSIBLE
FOR THE WEAK BAND OF SPRINKLES/-RA TO THE EAST OF THE INVERTED TROF.
RUC TRENDS SHOW THIS FORCING WEAKENING THROUGH SUNRISE AS THE
INVERTED TROF SLOWLY MOVES TO THE SOUTH AND WEST. THUS ANY
PRECIPITATION SHOULD BE CONFINED TO ROUGHLY THE SOUTHWEST HALF OF
THE CWFA AFTER SUNRISE.
THE INVERTED TROF GENERALLY EXITS THE CWFA BY MID MORNING AND THE
OVERALL FORCING/CONVERGENCE WEAKENS FURTHER. THUS MOST IF NOT ALL
THE PRECIPITATION SHOULD BE OVER BEFORE MID DAY. QUIET AND THEN
MAINLY DRY CONDITIONS SHOULD BE SEEN ACROSS THE AREA DURING THE
AFTERNOON.
TONIGHT...QUIET CONDITIONS WILL BE SEEN ACROSS THE CWFA.
INTERESTINGLY...THE HEAVY RAIN AND MCS TOOLS BRING CONVERGENCE AND
HIGHER RH DOWN ACROSS THE AREA. THE RH IS TRACEABLE TO THE LOW AND
MID CLOUDS CURRENTLY ACROSS NORTHERN MINNESOTA. SO...IT IS
CONCEIVABLE THAT A SUBTLE SHORTWAVE TOPPING THE RIDGE MAY BRING DOWN
THESE CLOUDS INTO THE AREA. IF CORRECT...THE CLOUDS SHOULD BREAK UP
SOMEWHAT DUE TO THE SUBSIDENCE OVER THE WESTERN GREAT LAKES IN THE
WAKE OF THE DEVELOPING EAST COAST STORM. 08
LONG TERM...MONDAY THROUGH NEXT SATURDAY
MONDAY WE REMAIN IN THE STRONG NORTHWEST FLOW AS THE STORM SYSTEM
OVER THE EAST COAST DEEPENS AND CAUSES THE FLOW TO AMPLIFY STRONGLY
OVER THE CONUS. THIS WILL ACT TO FUNNEL COOLER THAN NORMAL AIR DOWN
INTO THE REGION INTO TUESDAY. THERE IS SOME POTENTIAL FOR SOME
DIURNALLY DRIVEN SHOWERS ON MONDAY AFTERNOON WITH THE SURFACE RIDGE
STILL TO THE WEST AND SOME WEAK CONVERGENCE TO HELP START THEM OFF.
BY TUESDAY THE SURFACE RIDGE WILL HAVE SHIFTED EAST OF THE AREA SO
THIS IS LESS OF A CONCERN AND HAVE PUT IN A DRY FORECAST AND WARMER
TEMPERATURES.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT. A SHORTWAVE MOVES OVER THE
TOP OF THE UPPER LEVEL RIDGE TO OUR WEST DROPS DOWN IN THE NORTHWEST
FLOW. THIS...COMBINED WITH THE BAROCLINIC ZONE OVER THE AREA AS A
RESULT OF THE COLD AIR POOL TO OUR EAST SHOULD ACT TO GENERATE SOME
FRONTOGENESIS AS THIS FEATURES MOVES ON BY. TUESDAY NIGHT THE WARM
AIR ADVECTION/ISENTROPIC LIFT SHOWERS SHOULD BE MOVING INTO THE
AREA. THE SURFACE LOW MOVES ACROSS IOWA DURING THE DAY ON
WEDNESDAY...AND WE WILL HAVE THE COLD SIDE OF THE SYSTEM MOVE ACROSS
WEDNESDAY NIGHT. THERE ARE SOME CONCERNS THAT THE BULK OF THIS
SYSTEM WILL AFFECT AREAS NORTHEAST OF THE CWA DEPENDING ON THE
MODEL YOU LOOK AT...SO THE FORECAST IS STILL FOR JUST CHANCE POPS.
TEMPERATURES WITH THIS SYSTEM WILL BE WARMER THAN NORMAL TUESDAY
NIGHT AND WEDNESDAY...WITH COLDER TEMPS FOR WEDNESDAY NIGHT AS THE
TRAILING COLD FRONT MOVES THROUGH. THURSDAY TO BE COLDER AGAIN
BEHIND THE EXITING SYSTEM.
THURSDAY NIGHT THROUGH NEXT SATURDAY...HERE MORE QUESTION MARKS
ENTER THE FORECAST WITH MORE DIFFERENCES IN THE MODELS. THE UPPER
LEVEL RIDGE TO OUR WEST DURING THE MIDDLE OF THE WEAK BECOMES RATHER
PINCHED...AND IT GETS BODILY SHOVED EAST AS A FAIRLY POTENT UPPER
LOW SWINGS ACROSS THE FOUR CORNERS STATES. BY SATURDAY MORNING THE
MODELS ARE PUSHING A WARM AIR ADVECTION WING OF PRECIPITATION INTO
THE FORECAST AREA. WOULD NOT BE TOO SURPRISED TO SEE THIS SLOW DOWN
SOME...THOUGH THE MODELS HAVE BEEN FAIRLY CONSISTENT SO FAR.
LE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
326 PM CDT SUN APR 22 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 305 PM CDT SUN APR 22 2012
THE SHORT TERM CONCERN FOR TONIGHT WILL BE THE DEVELOPMENT OF FROST
AFTER MIDNIGHT. IT WAS A TOUGH CALL TO DETERMINE WHETHER THE
DURATION/INTENSITY OF ANY FROST DEVELOPMENT WOULD BE ENOUGH TO
WARRANT THE ISSUANCE OF A FROST ADVISORY FOR PARTS OF THE WFO PAH
FORECAST AREA. DESPITE THE CLIMATOLOGICAL ABILITY FOR WINDS TO
DECOUPLE IN THE WFO PAH FORECAST AREA...THE ENTIRE SUITE OF HIGH
RESOLUTION AND STATISTICAL NUMERICAL GUIDANCE IS LEADING CREDENCE
THAT THE WIND GRADIENT WILL REMAIN STRONG ENOUGH TO KEEP MIXING IN
PLACE FOR MOST LOCATIONS. THIS WOULD LIMIT THE DEVELOPMENT OF
FROST TO THOSE SITES THAT ARE NORMALLY WELL PROTECTED FROM WINDS.
HOWEVER...GIVE THE UNCERTAINTY ON THE CONSISTENCY OF WINDS SPEEDS
OVER THE ENTIRE PERIOD FROM MIDNIGHT THROUGH 8 AM CDT...A SPECIAL
WEATHER STATEMENT HAS BEEN ISSUED FOR THE ENTIRE FORECAST AREA. AN
ADDITIONAL MENTION WILL BE MADE IN THE HAZARDOUS WEATHER OUTLOOK
THIS AFTERNOON. THE EVENING FORECAST WILL NEED TO MONITOR WINDS
THIS EVENING...SHOULD THE GRADIENT RELAX FASTER THAN ANTICIPATED
AT THIS TIME.
THE CURRENT CONVECTION OVER THE WFO PAH FORECAST AREA SHOULD
LESSEN WITH THE LOSS OF INSOLATION AND TRANSLATION OF THE PRIMARY
CHANNELED VORTICITY OUT OF THE AREA TONIGHT. THE POTENTIAL FOR ANY
FURTHER ENHANCED CONVECTION /THUNDERSTORMS/ OVER SOUTHEAST MO/WEST
KENTUCKY SHOULD DROP OFF MARKEDLY BEFORE 5 PM CDT...WITH ANY
SHOWER ACTIVITY DIMINISHING BEFORE 8 PM CDT. THE 3KM HRRR AND 12KM
NAM-WRF DID A FAIRLY GOOD JOB OF DEPICTING THE
LOCATION/COVERAGE/INTENSITY OF THE CONVECTION TODAY AND WAS USED
AS A TEMPLATE IN PREPARING THE GRIDDED FORECAST UPDATES.
THERE WILL STILL BE SOME MINOR COLD AIR ADVECTION AND LIFT IN THE
DEPARTING CYCLONIC FLOW ON MONDAY...SO COLLABORATED WITH WFO ST.
LOUIS IN BEING MORE AGGRESSIVE WITH DIURNALLY-BASED COLD AIR
STRATOCUMULUS DEVELOPMENT DURING THE LATE MORNING AND AFTERNOON HOURS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 PM CDT SUN APR 22 2012
NOT MUCH CHANGE TO THE EXTENDED. PREFER TO STAY THE COURSE WITH ONLY
MINOR MODIFICATIONS VS. WHAT SOME OF THE NEW GUIDANCE...IN PARTICULAR
THE GFS IS DEPICTING. IT HAS SLOWED THE FRONTAL PASSAGE CONSIDERABLY
WEDNESDAY NIGHT THROUGH THURSDAY. IT HANGS THE FRONT UP ACROSS THE
AREA AND SUGGESTS THE CHANCE OF CONVECTION WILL NOT CLEAR THE AREA.
THIS IS IN STARK CONTRAST TO WHAT IT WAS SHOWING PRIOR. THE OTHER
MODELS CONTINUE TO PUSH THE FRONT ON THROUGH...ALTHOUGH PERHAPS NOT
QUITE AS FAR TO THE SOUTH AS PREVIOUSLY ADVERTISED. THE NEW 12Z
ECMWF CONTINUES TO PUSH THE FRONT ON THROUGH WITH TIME. BEST CHANCE
POPS WILL CONTINUE TO BE WEDNESDAY NIGHT IN CLOSE PROXIMITY TO THE
FRONT. SHRA/TSRA HIGH CHANCE TO LOW END LIKELY POPS WILL BE USED.
THE CHANCE OF ISOLATED SEVERE IS STILL UP FOR DEBATE AT THIS POINT AS
THE PARAMETERS ARE MARGINAL. HARD TO RULE OUT LOW END CHANCE POPS
FROM LATE FRIDAY ON INTO THE WEEKEND GIVEN THE UNSETTLED LOOK TO THE
PATTERN...ONCE THE MID LEVEL RIDGE PASSES BY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 121 PM CDT SUN APR 22 2012
MAIN CHALLENGE WITH THE 18Z SUNDAY ROUTINE TAF ISSUANCE WAS THE TIMING
OF THE THE MEAN CLOUD COVERAGE/HEIGHTS ASSOCIATED WITH THE RAPID
SOUTHEAST MOVING SYSTEM THROUGH THE WFO PAH TAF SITES. ATTEMPTED
TO KEEP VFR CEILINGS AS THE PREDOMINANT CLOUD COVER THROUGH THE
REMAINDER OF THIS AFTERNOON FOR KCGI/KPAH...AND THIS EVENING FOR
KEVV/KOWB. ALSO...WITH THIS PACKAGE...ATTEMPTED TO PIN DOWN THE
MOST LIKELY TIME FOR CONVECTIVE SHOWER ACTIVITY IN AND NEAR EACH
TAF SITE...BASED ON CURRENT AND PROJECTED TRENDS THIS AFTERNOON.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM....CTN
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS DULUTH MN
1246 PM CDT SUN APR 22 2012
.AVIATION...18Z TAF ISSUANCE...
MVFR AND LOW END VFR CIGS WILL LINGER THROUGH THIS AFTERNOON OVER
NORTHEASTERN MINNESOTA AND NORTHWESTERN WISCONSIN TODAY IN THE
WAKE OF A LOW PRESSURE SYSTEM. THERE MAY BE SHORT PERIODS OF IFR
CIGS. AT KDLH/KHIB/KBRD. SCATTERED RAIN AND SNOW SHOWERS WILL
AFFECT KDLH AND KBRD THROUGH AT LEAST THE EARLY AFTERNOON...BUT
THE PCPN SHOULD BEGIN TO DISSIPATE MID AFTERNOON. THE CIGS SHOULD
LIFT AND BEGIN TO SCATTER MID TO LATE AFTERNOON...WITH KINL
CLEARING FIRST. VFR CIGS ARE EXPECTED BY MID EVENING AS WEAK HIGH
PRESSURE ASSERTS ITSELF OVER THE REGION. MID TO HIGH CLOUDS WILL
FILL IN LATER TONIGHT AND TOMORROW MORNING...WITH LIGHT
SOUTHWESTERLY WINDS DEVELOPING AROUND DAWN.
&&
.PREV DISCUSSION... /ISSUED 1102 AM CDT SUN APR 22 2012/
UPDATE...MAIN ISSUE TODAY IS DISSIPATION RATE OF LARGE STRATUS
CLOUD FIELD LEFT IN WAKE OF DEPARTED SYSTEM. RUC13 85/70H LAYER
IS 90 PERCENT OR MORE OVER MOST OF ARROWHEAD/RANGE/BRD LAKES/TWIN
PORTS REGION. EROSION OF CLOUD DECK SHOULD OCCUR OVER NWRN CWA
SLOWLY TODAY ALTHOUGH INSTABILITY CU MAY REDEVELOP IN AFTERNOON
SUNSHINE. DEEP LAYER MOISTURE SHOULD ADVECT SLOWLY EAST INTO
WISCONSIN BY LATE AFTN. VERY LITTLE FORCING EVIDENT AT THIS TIME
AND 88D RETURNS HAVE BEEN DECREASING WITH TIME THIS MORNING. PTYPE
PLAYING THE BDRY LYR MERRY GO ROUND WITH RAIN/SNOW AT TIMES ACROSS
NRN MN ZONES. WILL KEEP IDEA THAT EVENTUALLY ANYTHING DESCENDING
THIS AFTN FROM THE CLOUDS WILL BE LIQUID.
PREV DISCUSSION... /ISSUED 408 AM CDT SUN APR 22 2012/
SHORT TERM...LATEST REGIONAL SURFACE ANALYSIS SHOWS THE DEPARTING
LOW PRESSURE SYSTEM NOW OVER IOWA EARLY THIS MORNING...WITH A
WEAK INVERTED TROUGH EXTENDING NORTH OF THE LOW OVER MINNESOTA TO
NEAR PARK RAPIDS. THERE IS ALSO A RIDGE OF HIGH PRESSURE EXTENDING
FROM NWRN ONTARIO SWWD ACROSS NWRN MN AND THE DAKOTAS...WHICH IS
SLOWLY BUILDING SWRD. HOWEVER WATER VAPOR SATELLITE IMAGERY
SHOWS A SECOND UPPER LEVEL VORTMAX OVER THE BORDER REGION...WHICH
IS PRODUCING ENOUGH LIFT FOR AREAS OF LIGHT PRECIP...MAINLY IN THE
FORM OF SNOW...ACROSS AREAS NORTHWEST OF THE IRON RANGE. FARTHER
SOUTH ACROSS THE BRAINERD LAKES REGION AND SAINT CROIX RIVER
VALLEY...AREAS OF LIGHT RAIN AND DRIZZLE CONTINUE TO FALL.
DUE TO THE WEAK SFC FEATURES COMBINED WITH ABUNDANT LOW LEVEL
MOISTURE...THE NWP MODELS SHOW SOME DIFFERENCES IN HOW THE THESE
AREAS OF PRECIP WILL EVOLVE ACROSS OUR CWA TODAY. HOWEVER THE
GENERALLY PATTERN IS TO GRADUALLY MOVE THE MAIN AXIS OF PRECIP
GRADUALLY EWD...WITH THE PRECIP COVERAGE DECREASING DURING THE
DAY. BY THIS EVENING...MAINLY DRY CONDITIONS ARE EXPECTED AS THE
RIDGE OF HIGH PRESSURE MOVES OVER THE NORTHLAND AND DRIER AIR
SPREADS SEWD ACROSS THE FCST AREA. THE RIDGE WILL REMAIN OVER THE
UPPER MIDWEST ON MONDAY AS A STRONG STORM SYSTEM LIFTS NEWD
ACROSS THE ERN THIRD OF THE COUNTRY. TEMPERATURES WILL MODERATE
TODAY...ALTHOUGH THE CLOUD COVER WILL KEEP TEMPS AT BELOW NORMAL
LEVELS. WARMER TEMPS ARE EXPECTED ON MONDAY AS SKIES BECOME
PARTLY CLOUDY AND WINDS TURN OUT OF A LIGHT WRLY DIRECTION.
LONG TERM...MONDAY NIGHT THROUGH SATURDAY.
AN UPPER LEVEL RIDGE WILL EXTEND NORTH FROM NEW MEXICO INTO THE
MT/SK EARLY IN THE PERIOD...WITH AN UPPER LOW OVER THE EASTERN
GREAT LAKES. THE MODELS ARE IN GOOD AGREEMENT ON THIS. HOWEVER...A
SURFACE LOW OVER THE NORTHERN PLAINS IS HANDLED QUITE DIFFERENTLY
BETWEEN THE GFS/ECMWF. THE GFS IS FASTER AND A BIT DEEPER WITH THE
LOW AND TAKES A FAR DIFFERENT TRACK COMPARED WITH THE ECMWF/GEM.
WE WENT CLOSER TO THE ECMWF. WE HAVE CHANCES FOR RAIN MONDAY NIGHT
INTO WEDNESDAY. A NICE BAROCLINIC ZONE IS ALSO FORECAST TO BE OVER
THE CWA...WITH THE MODELS SHOWING SOME FGEN DURING THIS PERIOD AS
WELL.
AS THE UPPER RIDGE MOVES EAST MID-LATE WEEK...A STRONG SURFACE HIGH
WILL DEVELOP BETWEEN THE UPPER RIDGE AND A TROUGH/LOW OVER QUEBEC/NE
CONUS. THIS HIGH WILL BRING IN SOME DRY AIR FOR THURSDAY THROUGH
FRIDAY NIGHT.
THE UPPER LEVEL RIDGE WILL PASS EAST OF THE REGION OVER THE
WEEKEND...ALLOWING A TROUGH TO BRING A CHANCE FOR PRECIP TO THE
NORTHLAND. THE GFS IS QUICKER BRINGING MOISTURE BACK INTO THE
NORTHLAND...AND WE DELAYED THE ARRIVAL IN THE NORTHEASTERN HALF OF
THE CWA UNTIL SATURDAY NIGHT.
WE EXPECT TEMPS FROM THE UPPER FIFTIES TO UPPER SIXTIES
TUESDAY...EXCEPT COOLER READING AROUND LAKE SUPERIOR...WITH MAINLY
FIFTIES FOR THE REMAINDER OF THE PERIOD. LOWS THURSDAY NIGHT AND
FRIDAY NIGHT COULD BE QUITE COOL WITH THE HIGH CREATING MAINLY CLEAR
SKIES AND LIGHT WINDS.
&&
.POINT TEMPS/POPS...
DLH 45 32 60 38 / 40 10 10 10
INL 51 29 60 35 / 40 10 10 20
BRD 51 32 63 39 / 50 10 0 10
HYR 52 30 60 36 / 30 10 0 10
ASX 49 32 59 35 / 20 10 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...CANNON
LONG TERM....GROCHOCINSKI
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
604 PM CDT SUN APR 22 2012
.UPDATE...
UPPER DISTURBANCE UPSTREAM CONTINUES TO PRODUCE A FEW SHOWERS
ACROSS SOUTHERN KY. LATEST GFS AND RUC SOLUTIONS CONTINUE TO
ENDORSE THE CONTINUATION OF A FEW LIGHT SHOWERS FOR THE MID STATE
INTO EARLY EVENING. OTW...REMAINDER OF FCST APPEARS TO BE IN GOOD
SHAPE WITH A SLIGHT DECREASE IN WIND SPEEDS...DECREASING CLOUD
COVER AND FALLING TEMPS WITH PATCHY LATE NIGHT FROST.
FOR THE UPDATE...WILL INCLUDE ISOL POPS FOR SHOWERS THROUGH EARLY
EVENING. THIS WILL THEREBY CALL FOR AN ADDITIONAL UPDATE BY 9 PM
OR SO.
UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 242 PM CDT SUN APR 22 2012/
DISCUSSION...CLOUDS WERE INCREASING ACROSS MID TN THIS AFTERNOON
AND A FEW SHOWERS WERE DEVELOPING OVER OUR WESTERN COUNTIES. MORE
SHOWERS WERE INDICATED OVER WEST KY AND SE MO...MOVING TOWARD WEST
SECTIONS OF THE MID STATE. TEMPERATURES WERE COOL...IN THE 50S TO
LOWER 60S...WITH A NW BREEZE TO 25 MPH AT TIMES.
A COUPLE OF MID/UPPER LOWS WERE OBSERVED...ONE MOVING NE FROM FL
AND THE OTHER DROPPING ACROSS THE OH VALLEY. THESE SYSTEMS WILL
BE COMING TOGETHER AS A NOR`EASTER FORMS AND BRINGS SIGNIFICANT WX
TO THE EAST COAST. THE MAIN FEATURE OF INTEREST FOR MID TN IS THE
UPPER LOW DROPPING ACROSS THE OH VALLEY THIS AFTERNOON. STEEP LAPSE
RATES WERE DEVELOPING...CAUSING INCREASING CLOUDS AND A FEW SHOWERS. AS
ADDITIONAL SHORTWAVE ENERGY SPINS AROUND THIS LOW...WE WILL
CONTINUE TO SEE A FEW SHOWERS...PERHAPS EVEN SOME
THUNDER...DEVELOP THROUGH LATE AFTERNOON. MODELS CONTINUE TO FOCUS
MOST ACTIVITY WEST OF I 65. THIS ACTIVITY IS LARGELY HEAT
DRIVEN...SO CONVECTION WILL DISSIPATE QUICKLY WITH SUNSET. WE WILL
POST LOW POPS FOR TONIGHT...BUT THAT APPLIES AFTER 00Z. ZONES WILL
INDICATE A LATE AFTERNOON PERIOD FOR MENTION OF POSSIBLE SHOWERS
OR THUNDERSTORMS (20-30 POPS) VALID FROM NOW UNTIL 00Z WHEN
ACTIVITY IS EXPECTED TO FIZZLE. LATER TONIGHT...CLEARING SKIES AND
CHILLY AIR WILL ALLOW TEMPERATURES TO FALL INTO THE 30S. WE WILL
MENTION PATCHY FROST IN THE FORECAST...BUT THIS REALLY ONLY
APPLIES OT THE MOST SHELTERED LOCATIONS. A PERSISTENT WIND THROUGH
THE NIGHT WILL NOT BE CONDUCIVE FOR FROST IN MOST AREAS.
ON MONDAY...SKIES WILL VARY FROM MOSTLY TO PARTLY SUNNY. IT WILL
BE ANOTHER CHILLY AND BREEZY DAY THANKS TO NW FLOW AND A TIGHT
PRESSURE GRADIENT ASSOCIATED WITH DEEP EAST COAST LOW PRESSURE
SYSTEM. TEMPS WILL BE AROUND 10 DEGREES BELOW NORMAL WITH NW WIND
GUSTS TO 30 MPH AT TIMES.
MONDAY NIGHT WILL BE CLEAR TO PARTLY CLOUDY AND CHILLY AGAIN. MANY
AREAS WILL DROP INTO THE 30S. THERE IS A GREATER RISK FOR FROST
MONDAY NIGHT...ALTHOUGH STILL NOT IDEAL FOR WIDESPREAD FROST.
FOR TUESDAY AND TUESDAY NIGHT...DIRTY NW FLOW WILL KEEP CONDITIONS
COOL WITH INTERVALS OF CLOUDS. A SMALL CHANCE FOR SHOWERS CANNOT
BE RULED OUT...BUT NOTHING SPECIFIC TO BASE POPS ON AT THIS TIME.
RAIN CHANCES WILL RAMP UP LATE WEDNESDAY INTO THURSDAY AS A FRONT
APPROACHES. MODELS HAVE BEEN INCONSISTENT ON THE EXACT PLACEMENT
OF THIS FRONT AS IT SETTLES ACROSS THE TN VALLEY AREA...STALLS...THEN
EVENTUALLY RETURNS NORTH LATE WEEK. THE EXACT LOCATION OF THE FRONT
WILL GREATLY INFLUENCE ALL FORECAST ELEMENTS. BECAUSE OF THE
UNCERTAINTY...WE WILL BROAD BRUSH MID TO LATE WEEK WITH CHANCES
FOR SHOWERS AND STORMS EACH DAY AND A MODEL BLEND FOR
TEMPERATURES.
13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
302 PM CDT SUN APR 22 2012
.SHORT TERM...TONIGHT AND MONDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A LOW PRESSURE
SYSTEM MOVING NORTH ALONG THE MID-ATLANTIC COASTLINE...WHILE SURFACE
HIGH PRESSURE STRETCHES FROM NORTHERN QUEBEC TO LAKE SUPERIOR...AND
SOUTH ACROSS THE GREAT PLAINS. A SURFACE TROUGH HAS REMAINED NEARLY
STATIONARY FROM NORTHERN MINNESOTA TO THE CENTRAL MISSISSIPPI RIVER
VALLEY...WHERE BKN-OVC LOW AND MID CLOUDS RESIDE. DRY NE WINDS
HAVE ERODED MUCH OF THE CLOUD COVER OVER NORTH-CENTRAL WISCONSIN
LEAVING ONLY FEW TO SCT CONDITIONS FROM WAUSAU TO LAND O LAKES.
WITH SURFACE FEATURES MOVING VERY LITTLE OVER THE NEXT 24
HOURS...CLOUD COVER AND TEMPS AND HUMIDITIES ARE THE MAIN FORECAST
CONCERNS.
TONIGHT...CLOSED UPPER LOW OVER THE OHIO VALLEY WILL SWING EAST TO
THE MID-ATLANTIC STATES TONIGHT. MEANWHILE...AREA OF HIGH PRESSURE
STRETCHING FROM THE NORTHERN PLAINS TO JAMES BAY WILL DRIFT SLIGHTLY
SOUTHWARD OVER THE WESTERN GREAT LAKES. PESKY AREA OF MID AND HIGH
CLOUDS OVER THE NORTHERN MISSISSIPPI VALLEY WILL ALSO SINK SOUTH AND
WILL PROVIDE SCT TO BKN CONDITIONS OVER THE WESTERN HALF OF THE
FORECAST AREA. NO REAL THREAT OF PRECIP FROM THESE CLOUDS.
OTHERWISE...QUIET CONDITIONS WITH LIGHT WINDS WILL BE IN PLACE. LOW
TEMPS RANGING FROM THE UPPER 20S NORTH TO MID 30S SOUTH.
MONDAY...HIGH PRESSURE WILL REMAIN IN PLACE ACROSS THE AREA...BUT
THE PRESSURE GRADIENT WILL TIGHTEN AS A RESULT OF LOW PRESSURE
MOVING NE ACROSS NEW ENGLAND. WILL SEE MOSTLY SUNNY AND WARMER
CONDITIONS...THOUGH WITH A GUSTY NORTH WINDS DEVELOPING IN THE
AFTERNOON. HIGHS MID 50S NORTH TO AROUND 60 DEGREES SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY...MAIN FCST CONCERNS
ARE PCPN TRENDS FOR THE MIDWEEK PERIOD AND NEXT WEEKEND.
NW FLOW WILL PREVAIL OVER WISCONSIN EARLY IN THE PERIOD...WITH A
STRONG UPPER RIDGE OVER THE ROCKIES AND AN UPPER LOW LIFTING FROM THE
EASTERN GREAT LAKES INTO QUEBEC. WEAK SFC HIGH PRESSURE SHOULD KEEP
GRB CWA DRY MONDAY NIGHT AND TUESDAY.
LOW PRESSURE OVER THE NORTHERN PLAINS ON TUESDAY EVG IS EXPECTED TO
SHIFT SE INTO ILLINOIS ON WEDNESDAY. A COUPLE JET STREAKS WILL
PASS OVER WI...PUTTING PART OF THE FCST AREA IN THE RRQ. A FAIRLY
STG BAROCLINIC ZONE WILL SET UP OVER THE REGION...WITH ISENT LIFT
DEVELOPING AS LLVL FLOW BECOMES S-SW AHEAD OF AN APPROACHING COLD
FRONT. HAVE CONTINUED WITH THE TREND OF HIGHEST POPS OVER OUR SW
COUNTIES...WHERE BEST MOISTURE...LIFT AND INSTABILITY IS EXPECTED.
WEAK HIGH PRESSURE AND ASSOCIATED DRY AIR WILL ALSO BE SLOW TO
PULL OUT OF NE WI. ALTHOUGH TIMING OF THE MAIN COLD FRONT IS A
QUESTION MARK RIGHT NOW...THE GENERAL CONCENSUS IS THAT IT SHOULD
MOVE THROUGH THE AREA WEDS AFTERNOON AND EVENING. SOME SHOWERS
MAY ALSO BE GENERATED WITH THIS FEATURE.
STRONG CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION ON
THURSDAY...AND LIKELY LINGER INTO AT LEAST THE EARLY PART OF THE
WEEKEND. FREEZING TEMPERATURES WILL ONCE AGAIN BE POSSIBLE...WITH
THE BEST CHANCE OCCURRING ON THURSDAY NIGHT.
MODELS ARE HAVING DIFFICULTY DETERMINING HOW LONG THE CANADIAN HIGH
WILL PERSIST OVER THE REGION...AND THE TIMING OF AN UPPER TROF
APPROACHING FROM THE PLAINS. THE ECMWF HAS BEEN MORE AGGRESSIVE
BRINGING PCPN INTO THE REGION OVER THE PAST COUPLE DAYS. FOR NOW...
HAVE REMOVED ANY POPS FROM THE SATURDAY FCST...AND KEPT LOW POPS
SAT NGT INTO SUNDAY.
&&
.AVIATION... SCT TO BKN MID AND HIGH CLOUDS WILL GRADUALLY SINK
SOUTH ACROSS WESTERN AND CENTRAL WISCONSIN THROUGH THIS EVENING
BEFORE DEPARTING LATE TONIGHT. THE PRESSURE GRADIENT WILL TIGHTEN
UP ON MONDAY AS DEEP LOW PRESSURE MOVES NORTH OVER THE
APPALACHIANS. WILL SEE NORTH WINDS STRENGTHEN AND BECOME GUSTY BY
MIDDAY ON MONDAY BUT CONDITIONS TO REMAIN VFR THROUGH MONDAY
AFTERNOON.
MPC
&&
.MARINE...THE PRESSURE GRADIENT WILL TIGHTEN TOMORROW AFTERNOON
BETWEEN HIGH PRESSURE OVER THE NORTHERN PLAINS AND LOW PRESSURE OVER
NEW ENGLAND. DO NOT HAVE MUCH INSTABILITY OVER NORTHERN LAKE
MICHIGAN...BUT THE PRESSURE GRADIENT ALONE MAY BE ABLE TO CREATE
SMALL CRAFT CRITERIA WINDS TOMORROW AFTERNOON.
&&
.FIRE WEATHER...AS LOW PRESSURE MOVES NE OVER NEW ENGLAND
TOMORROW...GUSTY NORTH WINDS WILL DEVELOP MONDAY AFTERNOON. THE
PRESSURE GRADIENT WILL BE TIGHTER OVER EASTERN WISCONSIN...WHERE
GUSTS TO AROUND 25 KTS WILL BE POSSIBLE. HIGHER DEWPOINTS FROM
WESTERN WISCONSIN WILL MIGRATE INTO CENTRAL WISCONSIN TOMORROW
AFTERNOON...WHILE NE WISCONSIN WILL SEE THE BEST MIXING AND HAVE
ACCESS TO THE DRIEST AIR. HUMIDITIES MAY FALL INTO THE 15-20 PCT
RANGE OVER THE SANDY SOIL AREAS OF NE WISCONSIN IN THE AFTERNOON
WHERE CRITICAL LEVELS WILL BE REACH FOR HUMIDITY AND WINDS.
TEMPERATURES WILL OBVIOUSLY FALL WELL SHORT EVERYWHERE. AFTER
COORDINATING WITH THE FOREST SERVICE...CONDITIONS ARE A BIT OF
STRETCH FOR A FIRE WEATHER WATCH TOMORROW AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1236 PM CDT SUN APR 22 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
300 AM CDT SUN APR 22 2012
MAIN FORECAST CONCERNS ARE ON THE NEXT PRECIPITATION CHANCES FOR
TUESDAY NIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED STRONG RIDGING OVER THE WESTERN U.S. BUILDING INTO SOUTHWEST
CANADA...WHILE TROUGHING WAS PRESENT FROM THE WESTERN GREAT LAKES
REGION SOUTH INTO FLORIDA. MAIN FEATURES OF NOTE TRAVERSING THROUGH
THE TROUGH INCLUDE: AN UPPER LOW NEAR FLORIDA...A POTENT SHORTWAVE
OVER SOUTHWEST IOWA...AND ANOTHER SHORTWAVE IN EASTERN NORTH DAKOTA.
THE POTENT SHORTWAVE HAS BEEN RESPONSIBLE FOR MUCH OF THE
PRECIPITATION AFFECTING THE WESTERN PORTION OF THE FORECAST AREA THE
PAST 18 HOURS...AN IN PARTICULAR A LOW TO MID LEVEL FRONTOGENESIS
ZONE AHEAD OF IT. RUC ANALYSIS SHOWED THIS FRONTOGENESIS HAS DROPPED
SOUTH INTO EASTERN IOWA...AND AS SUCH THE SHOWERS HAVE BEEN
WEAKENING OVER THE FORECAST AREA OVERNIGHT. ANOTHER FEATURE ALLOWING
PRECIPITATION TO WEAKEN IS AN AREA OF HIGH PRESSURE OVER NORTHEAST
ONTARIO. EASTERLY WINDS ARE ADVECTING DRIER AIR OUT OF THE HIGH INTO
THE FORECAST AREA...PARTICULARLY WISCONSIN. 00Z GRB SOUNDING HAD A
PRECIPITABLE WATER OF 0.26 INCHES. THE EASTERLY WINDS STOP AT AN
INVERTED TROUGH WHICH EXTENDS FROM JUST WEST OF MINNEAPOLIS SOUTH
INTO SOUTHEAST IOWA. AIRMASS REMAINS SEASONABLY COOL OVER THE AREA
WITH 850MB TEMPS BETWEEN 0 AND -2C PER 00Z RAOB ANALYSIS.
TODAY THROUGH MONDAY...OVER THE NEXT 24 TO 36 HOURS...A FAIRLY DEEP
TROUGH IS GOING TO FORM OVER THE EASTERN THIRD OF THE U.S....IN
RESPONSE TO THE CURRENT POTENT SHORTWAVE IN IOWA PHASING WITH THE
UPPER LOW IN FLORIDA. IN RESPONSE TO THIS PHASING...A STRONG SPRING
STORM WILL FORM OVER THE NORTHEAST. FOR THE FORECAST AREA...PLAN ON
MAINLY QUIET WEATHER AS HIGH PRESSURE OVER NORTHERN ONTARIO SLOWLY
SINKS SOUTH. THERE ARE STILL SOME ISSUES TO DEAL WITH...THOUGH. THE
FIRST OF WHICH IS THE LINGERING PRECIPITATION AND INVERTED TROUGH.
AS TODAY WEARS ON...THE INVERTED TROUGH SHOULD CONTINUE TO WEAKEN...
ESPECIALLY THIS EVENING WHEN THE SHORTWAVE OVER EASTERN NORTH DAKOTA
SLIDES SOUTH OF THE AREA. ISOLATED/SCATTERED SHOWERS SEEM POSSIBLE
TODAY NEAR THE INVERTED TROUGH...AIDED BY FOCUSED LOW LEVEL
CONVERGENCE AND MOISTURE. MAINTAINED SOME 20 PERCENT CHANCES IN THE
VERY FAR WESTERN PORTION OF THE FORECAST AREA THIS MORNING...IN
AGREEMENT WITH THE 22.00Z NAM/GFS AND LATEST HRRR RUNS. FOR THE REST
OF THE FORECAST AREA TODAY...AN INCREASING NORTHEAST FLOW WILL HELP
BRING IN LOW LEVEL DRY AIR. SOME CLEARING IS POSSIBLE...ESPECIALLY
OVER THE SOUTHEAST END OF THE AREA. TONIGHT...ALTHOUGH THE HIGH
PRESSURE AREA IS MOVING IN...THE NORTHWEST FLOW ALOFT SHOULD HELP
CARRY LOW TO MID LEVEL STRATUS SEEN OVER THE DULUTH AREA SOUTH
ACROSS THE FORECAST AREA. THESE CLOUDS SHOULD BE ENOUGH TO PREVENT
TEMPERATURES FROM REACHING A FROST/FREEZE SITUATION. SKIES ARE
EXPECTED TO CLEAR OUT MONDAY MORNING...THEN ANOTHER SURGE OF MID TO
HIGH CLOUDS ENTER THE PICTURE FROM THE NORTH IN THE AFTERNOON. THIS
IS ASSOCIATED WITH A SMALL PORTION OF THE WESTERN UPPER RIDGE THAT
IS PROGGED TO BUILD TOWARDS THE FORECAST AREA. WE WILL FEEL THIS TOO
BY AN INCREASE IN TEMPERATURES. 850MB TEMPS ARE ONLY 0 TO -2C
TODAY...RESULTING IN HIGHS ONLY IN THE MID 50S. HOWEVER...BY 00Z
TUESDAY...THEY CLIMB TO 2-4C...ALLOWING FOR HIGHS IN THE UPPER 50S
TO LOW 60S.
MONDAY NIGHT THROUGH TUESDAY NIGHT...FOCUS TURNS TO A LOW PRESSURE
SYSTEM PROGGED TO DEVELOP OVER SOUTH CENTRAL SASKATCHEWAN AT 00Z
TUESDAY...ON TOP OF THE UPPER RIDGE. VERY GOOD MODEL AGREEMENT
EXISTS THAT THE UPPER RIDGE WILL FLATTEN AND GET PUSHED SOUTH...IN
RESPONSE TO A SHORTWAVE ROUNDING THE RIDGE WHICH IS LOCATED OFF BAJA
CALIFORNIA RIGHT NOW. AS THE RIDGE FLATTENS...THE LOW PRESSURE
SYSTEM GETS SENT SOUTHEASTWARD INTO WESTERN IOWA BY 12Z WEDNESDAY.
WARM ADVECTION IS FORECAST AHEAD OF THE LOW OVER THE FORECAST AREA
DURING THE ENTIRE MONDAY NIGHT THROUGH TUESDAY NIGHT. 850MB TEMPS
RESPOND BY CLIMBING TO 6 TO 12C BY 00Z WEDNESDAY...WARMEST IN THE
FAR WESTERN PORTION OF THE FORECAST AREA. EVEN MORE WARMING IS
POSSIBLE TUESDAY NIGHT. THE BIGGER QUESTION...THOUGH...IS WHEN/IF
PRECIPITATION WILL OCCUR. PRECIPITABLE WATER VALUES START OFF FAIRLY
LOW AT 00Z TUESDAY...NEAR A 0.5 INCH. GOOD AGREEMENT EXISTS THAT
THESE WILL SLOWLY CLIMB TO NEAR AN INCH BY 00Z WEDNESDAY.
STILL...ISENTROPIC LIFT IS NOT ALL THAT IMPRESSIVE...SUGGESTING MUCH
OF THE WARM ADVECTION IS JUST GOING INTO WARMING. LIKELY TO SEE AN
INCREASE IN MID AND HIGH CLOUDS...THOUGH. THESE CLOUDS WILL HELP TO
KEEP TEMPERATURES UP MONDAY NIGHT. WITH A WARMER START TO
TUESDAY...INCREASING 850MB TEMPS AND FILTERED SUN...ANTICIPATING
HIGHS AT LEAST IN THE 60S AND POSSIBLY LOW 70S IN THE FAR WEST. BY
TUESDAY NIGHT...WITH THE LOW APPROACHING...THERE IS SOME SUGGESTION
OF LOW TO MID LEVEL FRONTOGENESIS INCREASING. THEREFORE...CHANCES OF
PRECIPITATION ARE NECESSARY TUESDAY NIGHT. DO NOT HAVE CONFIDENCE AT
THIS TIME TO GO HIGHER THAN 50 PERCENT AS WOULD LIKE TO SEE STRONGER
FORCING SIGNALS. WILL CONTINUE TO MENTION THUNDER WITH A PLUME OF
500-1000 J/KG OF MUCAPE ADVECTING INTO THE FRONTOGENESIS ZONE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY NIGHT
300 AM CDT SUN APR 22 2012
22.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES ARE IN PRETTY GOOD
AGREEMENT THROUGH THE ENTIRE LONG TERM PERIOD WITH BOTH THE UPPER
LEVEL AND SURFACE PATTERNS. FOR MUCH OF THE LONG TERM PERIOD...THE
FORECAST AREA IS UNDER THE INFLUENCE OF A CANADIAN HIGH PRESSURE
AREA WHICH DROPS DOWN INTO THE WESTERN GREAT LAKES REGION THURSDAY
MORNING. PRIOR TO THEN...THE LOW PRESSURE SYSTEM FROM TUESDAY NIGHT
AND THE FRONTOGENESIS ZONE AHEAD OF IT OVER THE AREA SHOULD REMAIN
MOSTLY IN PLACE ON WEDNESDAY...THEN HEAD OFF TO THE EAST WEDNESDAY
NIGHT. MAINTAINED 20-40 PERCENT CHANCES ON WEDNESDAY...HIGHEST
ALONG/SOUTH OF I-90...THEN JUST A 20 PERCENT CHANCE WEDNESDAY NIGHT
FOR THE DEPARTING PRECIPITATION. DRY AND COOLER CONDITIONS
ANTICIPATED FOR THURSDAY THROUGH FRIDAY WITH THAT CANADIAN HIGH
BUILDING DOWN. WENT TOWARDS THE COLD SIDE OF GUIDANCE FOR LOWS
THURSDAY NIGHT...WHERE FREEZE CONDITIONS SEEM LIKELY ALONG AND
NORTH OF I-94. WILL REALLY HAVE TO WATCH THIS NIGHT TEMPERATURE
WISE...GIVEN DEWPOINTS THAT ARE LIKELY TO DROP INTO THE 20S AND
MAYBE EVEN UPPER TEENS. AN UPPER RIDGE ON THE WEST SIDE OF THE
SURFACE HIGH IS ALSO A FEATURE TO WATCH. RIGHT NOW GOOD AGREEMENT
EXISTS THAT THIS UPPER RIDGE GET PUSHED INTO THE AREA ON SATURDAY
AS TROUGHING DEVELOPS OVER MUCH OF THE WESTERN U.S.. WILL SEE IF
THAT PROGRESSION STAYS...BUT WITH THAT RIDGE MOVING IN MEANS WARM
ADVECTION...AND THEREFORE CHANCES OF SHOWERS AND THUNDERSTORMS
ENTER THE PICTURE. SEEMS LIKE THE BETTER CHANCES FOR RAIN WOULD
COME SATURDAY NIGHT AND SUNDAY AS SHORTWAVES EJECT OUT OF THE
WESTERN TROUGH AND MOVE INTO THE AREA.
&&
.AVIATION...THROUGH 18Z MONDAY
1236 PM CDT SUN APR 22 2012
HIGH PRESSURE WILL MAINTAIN VFR CONDITIONS AT THE TAF SITES
THROUGH THE FORECAST PERIOD. LOOK FOR SCT-BKN CUMULUS CLOUDS TODAY
WITH CLOUD BASES AROUND 5 KFT. A WEAK MID LEVEL IMPULSE WILL DRIFT
SOUTH ACROSS THE AREA THIS EVENING BRINGING A BROKEN STRATUS DECK
ACROSS THE TAF SITES WITH CLOUDS BASES IN THE 5 TO 7 KFT RANGE.
LOOK FOR THESE CLOUDS TO BECOME SCATTERED AFTER 07Z. LOW PRESSURE
WILL EDGE INTO EASTERN LOWER MICHIGAN AS A SURFACE RIDGE OF HIGH
PRESSURE REMAINS ANCHORED ACROSS CENTRAL MINNESOTA INTO NORTHERN
MISSOURI. LOOK FOR WINDS TO SWITCH TO THE NORTH/NORTHWEST LATE
TONIGHT INTO MONDAY...INTO THE 10 TO 13 KT RANGE. WIND GUSTS TO
AROUND 20 KTS ARE POSSIBLE AT KLSE LATE MONDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 AM CDT SUN APR 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....WETENKAMP