Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 04/23/12
AREA FORECAST DISCUSSION
NWS ALBANY NY
149 PM EDT SAT APR 21 2012
.SYNOPSIS...
A MUCH NEEDED RAINFALL ON THE WAY. A COLD FRONT WILL GRADUALLY MOVE
EASTWARD ACROSS THE AREA TODAY...WHICH WILL BRING THE AREA ITS FIRST
WIDESPREAD MEASURABLE RAINFALL SINCE APRIL 1ST. AN AREA OF LOW
PRESSURE WILL APPROACH FROM THE SOUTH SUNDAY AND MOVE ACROSS THE
REGION MONDAY BRINGING A SOAKING RAINFALL.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM...CONVECTION IS DEVELOPING ACROSS EASTERN NY AS THIS
IS ALONG THE INSTABILITY GRADIENT PER THE HRRR/RUC13/LAPS. SURFACE
BASED PARCELS SUGGEST CAPES ARE APPROACHING 1K J/KG FROM THE
HUDSON RIVER VALLEY...INTO THE CATSKILLS. HRRR REFLECTIVITY IS
DOING VERY WELL AND EXPECTATION OF ADDITIONAL SCT-BKN LINE OF
CONVECTION TO SLOWLY MOVE ACROSS EASTERN NY COUNTIES THE REMAINDER
OF THE AFTERNOON. OTHERWISE...POST FRONTAL RAIN SHIELD WILL IMPACT
THE DACKS AND WESTERN MOHAWK VALLEY.
TEMPERATURE GRADIENT WILL BE QUITE IMPRESSIVE WITH TEMPERATURES
INTO THE UPPER 40S ACROSS PORTIONS OF THE DACKS WITH MID 70S INTO
THE MID HUDSON VALLEY AND LITCHFIELD COUNTY CT.
EXPECTING OUR FIRST WIDESPREAD MEASURABLE RAINFALL ACROSS THE
LOCAL AREA SINCE APRIL 1ST AS A COLD FRONTAL BOUNDARY GRADUALLY
MOVES EASTWARD ACROSS THE REGION. THIS BOUNDARY IS EXPECTED TO
BECOME NEARLY STATIONARY JUST OFFSHORE TONIGHT. THE ASSOCIATED
RAINFALL WILL OCCUR ALONG AND BEHIND THE BOUNDARY WITH WEAK WAVES
OF PRESSURE MOVE NORTHWARD ALONG IT. HAVE POPS DECREASING AFTER
MIDNIGHT TO UNDER LIKELY ACROSS ALL BUT THE SOUTHEAST PORTION OF
THE FORECAST AREA. EXPECTING 1/4 TO 3/4 INCHES OF RAINFALL TODAY
AND TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THE TIMING AND TRACK ON THE
SURFACE LOW UP THE SOUTHEAST COAST ALONG THE STALLED BOUNDARY. THE
GFSENSEMBLE MEMBERS AND OPERATIONAL RUNS ARE TIGHTLY CLUSTERED ALONG
THE MID ATLANTIC COAST SUNDAY NIGHT AND BRING THE LOW OVER NEW YORK
CITY MONDAY MORNING. THE ENSEMBLE SPREAD THEN INCREASES AS THE LOW
HEADS NORTH-NORTHWESTWARD ACROSS NEW YORK STATE MONDAY AFTERNOON AND
NIGHT AS ITS DRAWN UNDER THE UPPER LOW WHICH DEVELOPS OVER THE OHIO
VALLEY BY SUNDAY EVENING.
LULL IN THE RAINFALL IS EXPECTED SUNDAY MORNING ACROSS MOST OF THE
FORECAST AREA...ESPECIALLY THE NORTHERN AND WESTERN PORTIONS.
HOWEVER...THE RAIN WILL SPREAD BACK NORTHWARD SUNDAY AFTERNOON
BECOMING HEAVY AT TIMES SUNDAY EVENING AS THE SURFACE LOW APPROACHES
AND ITS ASSOCIATED STRONG LOW LEVEL JET MOVES INTO THE REGION.
AT THIS TIME...THE THERMAL PROFILES WILL SUPPORT SNOW ACROSS SOME OF
THE HIGHER TERRAIN OF THE FORECAST AREA SUNDAY NIGHT (MAINLY AFTER
MIDNIGHT) INTO EARLY MONDAY MORNING. MAINLY ABOVE 1500 FEET AND
PARTICULARLY ACROSS THE SOUTHERN ADIRONDACKS WHERE A LIGHT
ACCUMULATION IS POSSIBLE.
THE RAIN WILL LIGHTEN UP ON MONDAY AS THE LOW PASSES OVER THE AREA.
THE SYSTEM IS EXPECTED TO BECOME VERTICALLY STACKED MONDAY NIGHT AS
IT HEADS INTO CANADA.
AN ADDITIONAL 1 TO 3 INCHES OF RAINFALL IS EXPECTED WITH THE LOW
SUNDAY THROUGH MONDAY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
THE EXTENDED FORECAST PERIOD BEGINS WITH THE OCCLUDED CYCLONE
RESPONSIBLE FOR ALL THE ACTIVE WEATHER IN THE SHORT TERM SLOWLY
LIFTING N/NE INTO SE ONTARIO...AND SW QUEBEC. SHORT-WAVE ENERGY WILL
CONTINUE TO PIVOT AROUND THE UPPER LEVEL LOW WITH A MIX OF RAIN AND
SNOW SHOWERS IN THE MORNING. THE BETTER COLD AIR ADVECTION...AND
STEEPER LAPSE RATES ASSOCIATED WITH THE MID LEVEL COLD POOL ALOFT
WILL BE FROM THE HUDSON RIVER VALLEY WESTWARD. SOME LIGHT SNOW
ACCUMULATIONS OF A COATING TO AN INCH OR TWO IN THE MOUNTAINS...AND
ON THE GRASSY SURFACES IN THE VALLEYS...WILL BE POSSIBLE WEST OF
ALBANY. INSTABILITY SHOWERS WILL CONTINUE INTO THE AFTERNOON WITH
HIGHS IN U40S TO M50S OVER THE VALLEYS AND HILLS...AND U30S TO U40S
OVER THE MTNS.
TUESDAY NIGHT INTO WEDNESDAY...THE STACKED SYSTEM CONTINUES TO LIFT
AND MIGRATE N/NW TOWARDS JAMES BAY. A SERIES OF SFC TROUGHS WILL
MOVE ACROSS THE REGION WITH THE THREAT OF RAIN/SNOW SHOWERS AT
NIGHT...WITH THE BETTER CHC OF SNOW SHOWERS OVER THE MTNS...AND A
CHANCE OF SHOWERS DURING THE DAY. THE REGION WILL BE UNDER THE
INFLUENCE OF W/NW FLOW ALOFT...BUT LOW AND MID LEVEL TEMPS SLIGHTLY
MODERATE WITH H850 TEMPS RISING ABOVE 0C ACROSS MOST OF THE FCST
AREA BY WED PM...AND WITH A LATE APRIL SUN ANGLE...DOWNSLOPING AND
DEEPER MIXING...MAX TEMPS COULD REBOUND INTO THE MID 50S TO NEAR 60F
FROM THE CAPITAL REGION SOUTH AND EAST OVER THE BERKS...LITCHFIELD
HILLS...AND MID HUDSON VALLEY...WITH M40S TO L50S NORTH AND WEST OF
THE THE TRI CITIES. THIS WILL BE AFTER A CHILLY START WITH TEMPS IN
THE U20S TO L30S OVER THE MTNS...AND MID TO U30S IN THE VALLEYS.
WEDNESDAY NIGHT INTO FRIDAY...THE BROAD NEGATIVELY TILTED UPPER
TROUGH OVER THE EAST COAST WEAKENS...AS THE MID LEVEL FLOW FLATTENS
AND BECOMES MORE ZONAL BRIEFLY WED NIGHT INTO EARLY THU...AS A
CLIPPER LOW APPROACHES FROM THE MIDWEST. THE MEDIUM RANGE GUIDANCE
DIVERGENCES ON THE TIMING AND PLACEMENT OF THIS SYSTEM FOR THU. THE
ECMWF IS MUCH FURTHER SOUTH THAN THE GFS. THE GFS AMPLIFIES THE
LONGWAVE UPPER TROUGH...AS THE SFC WAVE LIFTS N/NE TOWARDS LONG
ISLAND...AND SRN NEW ENGLAND BY 12Z THU. CRITICAL THICKNESSES AND
THERMAL PROFILES INDICATE MAINLY RAIN FOR THE LOWER
ELEVATIONS...THOUGH SOME WET SNOW MAY BE POSSIBLE OVER THE HIGHER
TERRAIN...ONCE AGAIN...IF THE GFS IS RIGHT WITH THE PLACEMENT AND
TRACK. HPC LEANED CLOSER TO THE GFS...AND WE HAVE SIDED WITH IT FOR
NOW. THURSDAY NIGHT INTO FRIDAY...THE SFC WAVE DEEPENS AND
INTENSIFIES OVER THE CANADIAN MARITIMES...AS THE LONGWAVE TROUGH
AMPLIFIES OVER THE NORTHEAST...GREAT LAKES REGION...AND SE CANADA.
A CHILLY CANADIAN HIGH STARTS TO RIDGE IN FROM THE W-CNTRL GREAT
LAKES REGION TO CLOSE THE WEEK. THERE IS MAINLY A SLIGHT CHC OF A
SHOWER WITH AN UPPER LEVEL DISTURBANCE MOVING THROUGH ON FRI WHICH
WILL BE IN THE GRIDDED FCSTS. TEMPS DURING THIS TIME FRAME WILL BE
RUNNING A LITTLE COLDER THAN NORMAL WITH 50S TO L60S IN THE
VALLEYS...AND 40S TO L50S OVER THE MTNS. LOWS WILL BE IN THE U20S TO
30S FOR ERN NY AND WRN NEW ENGLAND.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A COLD FRONT WILL SLOWLY MOVE S/SE ACROSS THE REGION THROUGH THIS
EVENING WITH A WAVE OF LOW PRESSURE MOVING ALONG IT BRINGING
RAIN...HEAVY AT TIMES...TO THE REGION THROUGH MUCH OF TONIGHT.
VFR CONDITIONS THROUGH MUCH OF THIS AFTERNOON AT THE TAF SITES WILL
GIVE WAY TO MVFR/IFR CONDITIONS TONIGHT WITH A RETURN TO VFR
CONDITIONS FOR A TIME AROUND MID MORNING ON SUNDAY. STRONG LOW-LEVEL
CONVERGENCE ALONG THE FRONT WILL CONTINUE TO INCREASES THE CHANCE
OF RAIN STARTING AT KGFL ARND 18Z...KALB ARND 20Z AND KPOU BTWN 22Z
AND 00Z. THERE IS A POSSIBILITY OF ISOLATE THUNDERSTORMS...HOWEVER
PROBABILITY LOW ENOUGH TO LEAVE OUT OF THE TAFS AT THIS TIME. IN THE
WAKE OF THE COLD FRONT THE WINDS ARE EXPECTED TO SHIFT FROM S/SW TO
W/NW. AFTER 00Z...THE WINDS WILL CONTINUE TO VEER TO THE N/NW WITH A
STEADIER BAND OF RAIN.
THE WINDS WILL BE FROM THE S/SW AT AROUND 10 KTS UNTIL LATE THIS
AFTERNOON. THE WINDS WILL SHIFT TO W/NW AT 8-12 KTS LATE THIS
AFTERNOON...AND GENERALLY BE AROUND 10 KTS OR LESS OVERNIGHT INTO
SUNDAY MORNING.
.OUTLOOK...
SUN AFT-MON...VFR/MVFR...CHC IFR IN RAIN/HVY RAIN.
MON NT-WED NT...VFR/MVFR...CHC -SHRAS.
THU...VFR. NO SIG WX.
&&
.FIRE WEATHER...
A MUCH NEEDED RAINFALL ON THE WAY. A COLD FRONT WILL GRADUALLY MOVE
EASTWARD ACROSS THE AREA TODAY...WHICH WILL BRING THE AREA ITS FIRST
WIDESPREAD MEASURABLE RAINFALL SINCE APRIL 1ST. AN AREA OF LOW
PRESSURE WILL APPROACH FROM THE SOUTH SUNDAY AND MOVE ACROSS THE
REGION MONDAY BRINGING A SOAKING RAINFALL.
&&
.HYDROLOGY...
MUCH NEEDED RAINFALL ON THE WAY WHICH HELP TO ALLEVIATE DROUGHT
CONDITIONS. A COLD FRONT WILL GRADUALLY MOVE EASTWARD ACROSS THE
AREA TODAY...WHICH WILL BRING THE AREA ITS FIRST WIDESPREAD
MEASURABLE RAINFALL SINCE APRIL 1ST. AN AREA OF LOW PRESSURE WILL
APPROACH FROM THE SOUTH SUNDAY AND MOVE ACROSS THE REGION MONDAY
BRINGING A SOAKING RAINFALL.
PRECIPITATION ASSOCIATED WITH THE PASSAGE OF THE FRONTAL BOUNDARY
TODAY AND TONIGHT IS EXPECTED TO BE 1/4 TO 3/4 INCHES. THE
PRECIPITATION ASSOCIATED WITH THE AREA OF LOW PRESSURE SUNDAY INTO
MONDAY IS EXPECTED TO BE 1 TO 3 INCHES. THE HIGHEST PRECIPITATION
RAINFALL AMOUNTS EXPECTED SOUTH AND EAST OF THE CAPITAL DISTRICT
ESPECIALLY ACROSS LITCHFIELD COUNTY.
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...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/BGM/11
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...11
FIRE WEATHER...IAA
HYDROLOGY...IAA
CLIMATE...IAA
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS MIAMI FL
1038 PM EDT SUN APR 22 2012
.UPDATE...WINDS OVER LAKE OKEECHOBEE CONTINUE AROUND 20 KT WITH
GUSTS TO AROUND 25 KT...SO EXTENDED THE SCA FOR THE LAKE UNTIL 6
AM MON. OTHERWISE, NO CHANGES TO THE FORECAST ARE NEEDED THIS
EVENING. HIGH PRESSURE WILL CONTINUE TO BUILD INTO FLORIDA FROM
THE NORTHWEST, RESULTING IN RATHER COOL AND DRY CONDITIONS OVER
THE NEXT FEW DAYS. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 734 PM EDT SUN APR 22 2012/
AVIATION...
REMNANT PRECIPITATION ASSOCIATED WITH THE DEPARTED UPPER LEVEL
SYSTEM IS ALL BUT GONE FROM THE SOUTH FLORIDA AREA. ONLY A FEW
SPRINKLES REMAIN AROUND KPBI BUT SHOULD MOVE ON QUICKLY. THE ONLY
FACTOR THROUGH THIS TAF PERIOD WILL BE THE GUSTY WESTERLY GRADIENT
WINDS IN THE WAKE OF THIS SYSTEM. WINDS SHOULD REMAIN GUSTY
THROUGH THE OVERNIGHT HOURS AT ALL SITES.
PREV DISCUSSION... /ISSUED 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-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 TAMPA BAY RUSKIN FL
910 PM EDT SUN APR 22 2012
.UPDATE )TONIGHT THROUGH MONDAY)...
23/00Z WATER VAPOR AND H4 RUC ANALYSIS SHOWS A HIGHLY AMPLIFIED
UPPER LEVEL PATTERN IN PLACE OVER THE CONUS. LONGWAVE PATTERN
CONSISTS OF RIDGING OVER THE WESTERN HALF OF THE NATION AND DEEP
TROUGHING OVER THE EASTERN STATES. EASTERN TROUGH IS ANCHORED BY A
545DM H5 UPPER LOW SPINNING OVER THE TN/OH VALLEYS. ROUNDING THE
BASE OF THE TROUGH AND BEGINNING TO ITS ADVANCE UP THE EASTERN
SEABOARD IS THE POTENT SHORTWAVE ENERGY WHICH CROSSED THE FL
PENINSULA SATURDAY NIGHT AND BROUGHT SEVERAL ROUNDS OF SHOWERS AND
STORMS TO THE REGION. LARGE SCALE SUBSIDENCE IN THE WAKE OF THIS
ENERGY HAS SIGNIFICANTLY DRIED OUT THE ATMOSPHERIC COLUMN OVER THE
FORECAST AREA AND SKIES ARE NOW RAPIDLY CLEARING. 00Z KTBW SOUNDING
PROFILE SHOWS THIS PATTERN WITH A WELL-DEFINED SUBSIDENCE INVERSION
ABOVE 800MB.
AT THE SURFACE...TIGHT PRESSURE GRADIENT IN PLACE OVER THE PENINSULA
AND EASTERN GULF IN THE WAKE OF RAPIDLY DEEPENING LOW PRESSURE OFF
THE CAROLINA COAST. THIS LOW WILL FOLLOW ITS PARENT UPPER LEVEL
ENERGY RAPIDLY UP THE EASTERN SEABOARD AND PROVIDE A RAINY/WINDY
NIGHT TO THE MID-ATLANTIC/NORTHEASTERN STATES. NO RAIN CHANCES FOR
OUR REGION AS THE DRYING ALOFT IS ALSO OCCURRING IN THE LOWER
LEVELS. THE DRIER AIR AND CONTINUED COLD AIR ADVECTION THROUGHOUT
THE NIGHT WILL RESULT IN NOTICEABLY COOLER TEMPERATURES BY SUNRISE.
LOOKING FOR INLAND LOW TEMPERATURES TO DIP DOWN INTO THE 50S...AND
EVEN A FEW UPPER 40S TOWARD INLAND LEVY/CITRUS COUNTIES. THE ONSHORE
FLOW WILL KEEP THE IMMEDIATE COAST A BIT WARMER...BUT STILL LOOKING
FOR LOWS TO DIP INTO THE LOWER 60S.
MONDAY...A FAIR AND COOL DAY FOR LATE APRIL ON TAP. MOSTLY SUNNY
SKIES WILL GIVE WAY TO A FEW AFTERNOON CLOUDS. THE UPPER TROUGH WILL
CONTINUE TO DIG/SHARPEN INTO THE SOUTHEASTERN STATES WITH CONTINUED
CAA THROUGH A DEEP LAYER. 850MB TEMPS BY THE EVENING ARE PROGGED TO
DROP AS LOW AS +2C OVER OUR NORTHERN ZONES AND +5C DOWN TOWARD FT.
MYERS. BOTH OF THESE VALUES ARE ON THE ORDER OF 2-3 STANDARD
DEVIATIONS BELOW CLIMATOLOGY FOR LATE APRIL. EVEN WITH EXCELLENT
DIURNAL MIXING...WE WILL ONLY MANAGE AFTERNOON HIGH TEMPS IN THE
LOWER 70S NORTH AND MIDDLE/UPPER 70S SOUTH.
&&
.AVIATION...
VFR CONDITIONS FOR THE NEXT 24 HOURS. SKIES WILL BECOME MOSTLY
CLEAR OVERNIGHT WITH WINDS DECREASING TO AROUND 10 KNOTS BY
MIDNIGHT. DAYTIME HEATING SUNDAY WILL CREATE SCATTERED STRATO-CU
040-050. GRADIENT WILL REMAIN TIGHT OVER THE AREA WITH NORTHWEST
WINDS GUSTING BETWEEN 20 TO 25 KNOTS THROUGH SUNDAY AFTERNOON.
&&
.MARINE...
A TIGHT PRESSURE GRADIENT IN THE WAKE OF THE DEPARTING UPPER AND
SURFACE LOWS WILL MAINTAIN SOLID SMALL CRAFT CONDITIONS OVER THE
ADJACENT GULF AND TAMPA BAY WATERS TONIGHT THROUGH MONDAY WITH
NORTHWEST WINDS IN THE 20 TO 25 KNOT RANGE WITH HIGHER GUSTS WITH
SEAS OF 5 TO 7 FEET NEAR SHORE...AND 7 TO 10 FEET OFFSHORE. GIVEN
CURRENT AND EXPECTED WIND AND SEA TRENDS WILL MAINTAIN SMALL CRAFT
AND HIGH SURF ADVISORY HEADLINES THROUGH MONDAY WITH HAZARDOUS
BOATING CONDITIONS EXPECTED. WIND AND SEAS WILL DIMINISH AND SUBSIDE
TUESDAY THROUGH FRIDAY AS SURFACE HIGH PRESSURE BUILDS IN OVER THE
GULF.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 59 74 52 72 / 0 0 0 0
FMY 61 79 56 76 / 0 0 0 0
GIF 54 76 51 72 / 0 0 0 0
SRQ 59 76 53 71 / 0 0 0 0
BKV 52 73 41 72 / 0 0 0 0
SPG 64 71 59 72 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY
EVENING FOR CHARLOTTE-CITRUS-DE SOTO-HARDEE-HERNANDO-
HIGHLANDS-HILLSBOROUGH-LEE-LEVY-MANATEE-PASCO-POLK-
SARASOTA-SUMTER.
HIGH SURF ADVISORY UNTIL 8 PM EDT MONDAY FOR CHARLOTTE-
CITRUS-HERNANDO-HILLSBOROUGH-LEE-LEVY-MANATEE-PASCO-
PINELLAS-SARASOTA.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 11 PM EDT MONDAY FOR BONITA
BEACH TO ENGLEWOOD OUT 20 NM-ENGLEWOOD TO TARPON
SPRINGS OUT 20 NM-TARPON SPRINGS TO SUWANNEE RIVER
OUT 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT TUESDAY FOR BONITA
BEACH TO ENGLEWOOD OUT 20 TO 60 NM-ENGLEWOOD TO
TARPON SPRINGS OUT 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 5 PM EDT MONDAY FOR TARPON
SPRINGS TO SUWANNEE RIVER OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
TAMPA BAY WATERS.
&&
$$
UPDATE...14/MROCZKA
AVIATION...13/OGLESBY
AREA FORECAST DISCUSSION
NWS MIAMI FL
734 PM EDT SUN APR 22 2012
.AVIATION...
REMNANT PRECIPITATION ASSOCIATED WITH THE DEPARTED UPPER LEVEL
SYSTEM IS ALL BUT GONE FROM THE SOUTH FLORIDA AREA. ONLY A FEW
SPRINKLES REMAIN AROUND KPBI BUT SHOULD MOVE ON QUICKLY. THE ONLY
FACTOR THROUGH THIS TAF PERIOD WILL BE THE GUSTY WESTERLY GRADIENT
WINDS IN THE WAKE OF THIS SYSTEM. WINDS SHOULD REMAIN GUSTY
THROUGH THE OVERNIGHT HOURS AT ALL SITES.
&&
.PREV DISCUSSION... /ISSUED 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.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
154 AM EDT SAT APR 21 2012
.AVIATION...
CERTAINLY NEED TO STRESS THE UNCERTAINTY IN THE FORECAST WITH THE
POTENTIAL FOR CONVECTION AND ASSOCIATED THUNDERSTORMS CONTINUING
THROUGH THE EARLY MORNING HOURS. FOR THE SHORT TERM...ASSIGNED
VCTS FOR TERMINAL KAPF WITH THE MOST ACTIVE AREA OF THUNDERSTORMS
REMAINING ACROSS THE LOCAL GULF WATERS. SHOWERS WILL LIKELY
CONTINUE TO AFFECT TERMINAL KAPF THROUGHOUT THE MORNING HOURS WITH
VISIBILITIES REDUCE TO PERHAPS 4 SM TO 5 SM WITH MODERATE SHOWERS
WITH OCCASIONALLY HEAVY SHOWERS POSSIBLE WITH PERIODS OF IFR
CONDITIONS POSSIBLE WITH HEAVY SHOWERS OR A THUNDERSTORM. FOR THE
EAST COAST TAFS,...FOR NOW CONVECTION HAS SUBSIDED WITH VFR
CONDITIONS PREVAILING. HOWEVER...GIVEN THE INSTABILITY ACROSS THE
AREA AND WITH LINGERING BOUNDARIES FROM EARLIER
CONVECTION...SHOWERS AND/OR THUNDERSTORMS COULD HAPPEN AT ANY TIME
WITH BRIEF PERIODS OF IFR CONDITIONS POSSIBLE. BY 12Z SATURDAY A
SURFACE LOW IS FORECAST TO BUILD INTO THE NORTHEAST GULF WHICH
WILL CONTRIBUTE TO THE CONTINUING POTENTIAL FOR CONVECTION AND
THUNDERSTORMS FOR ALL TAF SITES WITH BRIEF PERIODS OF IFR
CONDITIONS POSSIBLE WITH OCCURRENCE OF HEAVY SHOWERS AND THUNDERSTORMS.
60
&&
.PREV DISCUSSION... /ISSUED 1008 PM EDT FRI APR 20 2012/
UPDATE...
SOUTHWEST PROPAGATING OUTFLOW BOUNDARIES FROM EARLIER CONVECTION
ARE SPARKING FURTHER SHOWERS AND THUNDERSTORMS BACK ACROSS
INTERIOR AREAS AND TO THE GULF COAST. LATEST HRRR ALSO DEPICTS
CONVECTION IN THE CENTRAL AND WESTERN GULF OF MEXICO OUT AHEAD OF
THE LARGER H5 LOW TO PUSH ASHORE AROUND 05Z. INCREASED POPS TO
ADJUST FOR CURRENT RADAR TRENDS.
PREV DISCUSSION... /ISSUED 803 PM EDT FRI APR 20 2012/
UPDATE...
SENT UPDATE TO INCREASE POPS ACROSS ALL OF SOUTH FLORIDA THIS
EVENING...ESPECIALLY ACROSS PALM BEACH AND BROWARD COUNTIES AND
ACROSS LAKE OKEECHOBEE. SHOWERS AND THUNDERSTORMS CONTINUE TO PUSH
TO THE EAST BUT ARE ALSO BACK BUILDING. STRONGEST STORMS ARE IN A
WEAKENING PHASE AND SHOULD CONTINUE TO WEAKEN THROUGH THE LATE
EVENING HOURS.
PREV DISCUSSION... /ISSUED 747 PM EDT FRI APR 20 2012/
AVIATION...
ONGOING CONVECTION CONTINUES TO AFFECT EAST COAST TERMINALS WITH
THE EXCEPTION OF KMIA AND KTMB ATTM. ACTIVITY IS SLOWLY PUSHING TO THE
EAST BUT LATEST TRENDS DEPICT CB TOWERS BUILDING BACK TO THE WEST.
CONVECTION SHOULD WEAKEN SOMEWHAT DURING THE OVERNIGHT HOURS
BEFORE ANOTHER WAVE OF SHRAS/TSRAS BEGIN TO PUSH INTO SOUTH
FLORIDA SATURDAY MORNING. ACTIVITY DURING THE DAY ON SATURDAY AND
ESPECIALLY SATURDAY EVENING IS EXPECTED TO BE STRONGER AND MORE
EXTENSIVE.
PREV DISCUSSION... /ISSUED 215 PM EDT FRI APR 20 2012/
STRONG TO SEVERE STORMS POSSIBLE OVER S FLA THIS WEEKEND...
TWO ROUNDS OF THUNDERSTORM ACTIVITY FOR SOUTH FLORIDA...
AMPLIFYING UPPER RIDGE OVER THE RKY MTN CHAIN INTO S CANADA ALLOWING
A DEEPENING TROUGH OVER THE CENTRAL GREAT PLAINS TO PLUNGE INTO THE
LOWER MS RIVER VALLEY WITH A CLOSED LOW DEVELOPING OFF OF THE GULF
COAST DURING THE DAY SATURDAY. THIS CLOSED LOW WILL CONTINUE TO DIVE
SE INTO THE CENTRAL GULF BEFORE LIFTING TO THE NE SATURDAY EVENING
AND CROSSING N FLA SUNDAY MORNING AND THEN NE ALONG THE SE U.S.
COAST SUNDAY AFTERNOON. ANOTHER SHORT WAVE DIVING SE ACROSS THE
GREAT LAKES REGION ABSORBS THE E COAST LOW INTO A CLOSED LOW OVER
THE E OHIO RIVER VALLEY THAT MOVES NORTHWARD INTO S CANADA.
SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...AS THE UPPER TROUGH
CONTINUES TO DEVELOP...THE S FLA AREA WILL BE UNDER AN INCREASING
AND BECOMING DIVERGENT SW WIND FLOW ALOFT WITH EMBEDDED IMPULSES
GENERATING CONVECTION. THE DIURNAL CONVECTION TODAY WILL LINGER INTO
THE EVENING HOURS MAINLY NE BUT DEVELOPING ACTIVITY OVER THE S
CENTRAL GULF WILL SPREAD NE AND ONTO THE W COAST LATE TONIGHT AND
SPREAD ACROSS S FLA TO THE E COAST BY SATURDAY MORNING. ACTIVITY
COULD GET ACTIVE ESPECIALLY ON THE W COAST BUT WEAKEN SOME UPON
REACHING THE E COAST. WITH CLOUD COVER AND A SLIGHTLY MORE STABLE
ATMOSPHERE EARLY SATURDAY...HEAVY CONVECTION MAY BE LIMITED DURING
THE DAY BUT A LITTLE HEATING IN THE MOIST ATMOSPHERE ( BECOMING 2
STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR ) WITH
POSSIBLE LAKE/SEA BREEZES...SHOWER/THUNDERSTORM ACTIVITY CAN AGAIN
BE EXPECTED. WITH THE INCREASED MOISTURE IN THE ATMOSPHERE
POSSIBLE TRAINING OF ECHOES...LOCALLY HEAVY RAINS...WILL NOT BE
OUT OF THE QUESTION ESPECIALLY W. LATE SATURDAY AFTERNOON AND INTO
SATURDAY NIGHT....IT APPEARS THAT THE STRONGEST IMPULSE WILL MOVE
OVER S FLA. STRONG STORMS CAN BE EXPECTED TO DEVELOP IN THE GULF AND
ACROSS S FLA WITH EVEN SEVERE STORMS POSSIBLE. THE MAIN THREAT IS
EXPECTED TO BE DAMAGING WINDS BUT ISOLATED TORNADOES AND LARGE HAIL
ARE ALSO POSSIBLE. DECREASING CONVECTION EXPECTED SUNDAY WITH ALL
ACTIVITY ENDING SUNDAY NIGHT. UNCERTAINTY STILL EXISTS AS THE MODELS
HAVE BEEN WAFFLING ON THE TIMING BUT THIS IS THE CURRENT THINKING.
RESIDENTS AND VISITORS IN SOUTH FLORIDA ARE URGED TO KEEP ABREAST OF
THE LOCAL FORECAST AS THIS WEATHER SITUATION CONTINUES TO UNFOLD.
EXTENDED PERIOD...MONDAY THROUGH FRIDAY...A DRY NW WIND FLOW WILL
BE OVER S FLA THROUGH THE PERIOD WITH NO PRECIPITATION EXPECTED.
MAX/MIN TEMPS A BIT BELOW NORMAL FOR A COUPLE OF DAYS THEN A SLOW
WARMING REND TOWARD THE END OF THE WEEK.
MARINE...MARINE CONDITIONS REALLY BEGIN TO DETERIORATE AHEAD OF THE
APPROACHING LOW/FRONT SATURDAY AFTERNOON WITH WINDS INCREASING ABOVE
ADVISORY CRITERIA POSSIBLY AS EARLY AS SATURDAY NIGHT. THE INCREAS
-ING SW WIND FLOW WILL LEAD TO AN INCREASE IN THE RISK OF RIP
CURRENTS AND ROUGH SURF ALONG THE WEST COAST OF S FLA BEGINNING AS
EARLY AS SATURDAY AFTERNOON. SOME COASTAL FLOODING ALONG THE W
COAST OF S FLA WILL ALSO BE POSSIBLE. WATER LEVELS MAY REACH 1 TO 2
FT ABOVE THE REGULAR HIGH TIDE FROM LATE SATURDAY AFTERNOON THROUGH
SUNDAY AFTERNOON ANYWHERE FROM MARCO ISLAND TO EVERGLADES CITY. ANY
AREAS TYPICALLY VULNERABLE TO MINOR COASTAL FLOODING SHOULD CONTINUE
TO MONITOR THE LATEST FORECASTS AS THIS GULF LOW PRESSURE SYSTEM
DEVELOPS AND TRACKS EAST OVER THE FL PENINSULA.
FIRE WEATHER...NO CONCERNS AT THIS TIME BUT MUCH DRIER CONDITIONS
ARE EXPECTED TO SPREAD ACROSS S FLA EARLY NEXT WEEK WITH RH FALLING
AT OR BELOW 35%.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 70 85 65 / 80 70 50 20
FORT LAUDERDALE 82 71 86 67 / 80 70 50 20
MIAMI 83 70 85 67 / 80 70 50 20
NAPLES 82 69 81 66 / 80 70 50 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...47/RGH
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS DES MOINES IA
310 PM CDT SAT APR 21 2012
.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...21/18Z
BAND OF SHOWERS WITH MAINLY LOW VFR CIGS MOVING ACROSS ERN HALF OF
IA EARLY THIS AFTERNOON. THERE ARE A FEW SMALL PATCHES OF MVFR CIGS
AND MAY AFFECT KALO AS WELL. PARENT UPPER LOW IS STILL ALONG ND/MN
BORDER HOWEVER AND MOVING SE SO AFFECTS OF THIS SYSTEM WILL LINGER
INTO SUN. PRECIP TRENDS UNCERTAIN AND DO NOT WANT TO CARRY A LONG
PERIOD UNNECESSARILY SO NOTHING MORE THAN VCSH WORDING LATER TODAY
AND TONIGHT...MOST LIKELY PERIOD...UNTIL TRENDS BECOME CLEARER.
THERE ARE SOME MINIMAL THUNDER CHANCES BUT NOT ENOUGH TO MENTION
YET. EXPECT CIGS TO LIFT TOWARD THE END OF THE PERIOD AS SYSTEMS
EXIT.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...JOHNSON
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1020 PM CDT SUN APR 22 2012
.UPDATE...
ISSUED AT 1020 PM CDT SUN APR 22 2012
UPDATED FORECAST TO LESSEN THE MENTION OF FROST FROM /AREAS OF/ TO
/PATCHY/...AND ACROSS A SMALLER GEOGRAPHIC AREA. A NORTH BREEZE
IS EXPECTED TO KEEP TEMPERATURES A FEW DEGREES HIGHER THAN
ORIGINALLY THOUGHT OVERNIGHT...THUS LESSENING THE POTENTIAL FOR
SIGNIFICANT FROST FORMATION. PATCHY FROST IS STILL POSSIBLE
TOWARDS DAYBREAK...MAINLY IN LOCATIONS OF SOUTHERN ILLINOIS...
SOUTHEAST MISSOURI...AND FAR WESTERN KENTUCKY THAT ARE SHELTERED
FROM THE WIND.
&&
.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 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 644 PM CDT SUN APR 22 2012
AN AREA OF MORE SOLID CLOUDS WITH A FEW SCATTERED LIGHT SHOWERS
WILL SHIFT SOUTHWARD OUT OF THE KCGI AND KPAH AREAS BY 03Z THIS
EVENING...WHILE MORE SCATTERED CLOUDS IN THE SAME 5-8KFT LAYER
WILL ROTATE BACK ACROSS AREAS EAST OF THE MISSISSIPPI RIVER
THROUGH MUCH OF THE NIGHT. A FEW GUSTS ABOVE 20KTS WILL BE
POSSIBLE WITH ANY SHOWERS THIS EVENING. OTHERWISE WINDS SHOULD
SETTLE DOWN TO JUST UNDER 10KTS OVERNIGHT...PREVENTING ANY FOG
DEVELOPMENT.
MODEL SOUNDINGS INDICATE VERY DEEP AND STRONG MIXING FOR MONDAY.
THIS WILL KICK IN GUSTY NORTH WINDS AROUND 15Z...WITH EVEN
STRONGER WINDS IN THE AFTERNOON. THE DEEP MIXING WILL EVENTUALLY
LEAD TO A BROKEN LAYER OF CLOUDS AROUND 7KFT IN MOST AREAS FOR THE
MID AND LATE AFTERNOON. IN THE NORTHEAST WHERE THE MIXING WILL BE
DEEPEST...A FEW LIGHT SHOWERS WILL BE POSSIBLE NEAR THE END OF THE
PERIOD.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...RJP
SHORT TERM...SMITH
LONG TERM....CTN
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
644 PM CDT SUN APR 22 2012
.UPDATE...
ISSUED AT 644 PM CDT SUN APR 22 2012
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 00Z TAF ISSUANCE.
&&
.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 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 644 PM CDT SUN APR 22 2012
AN AREA OF MORE SOLID CLOUDS WITH A FEW SCATTERED LIGHT SHOWERS
WILL SHIFT SOUTHWARD OUT OF THE KCGI AND KPAH AREAS BY 03Z THIS
EVENING...WHILE MORE SCATTERED CLOUDS IN THE SAME 5-8KFT LAYER
WILL ROTATE BACK ACROSS AREAS EAST OF THE MISSISSIPPI RIVER
THROUGH MUCH OF THE NIGHT. A FEW GUSTS ABOVE 20KTS WILL BE
POSSIBLE WITH ANY SHOWERS THIS EVENING. OTHERWISE WINDS SHOULD
SETTLE DOWN TO JUST UNDER 10KTS OVERNIGHT...PREVENTING ANY FOG
DEVELOPMENT.
MODEL SOUNDINGS INDICATE VERY DEEP AND STRONG MIXING FOR MONDAY.
THIS WILL KICK IN GUSTY NORTH WINDS AROUND 15Z...WITH EVEN
STRONGER WINDS IN THE AFTERNOON. THE DEEP MIXING WILL EVENTUALLY
LEAD TO A BROKEN LAYER OF CLOUDS AROUND 7KFT IN MOST AREAS FOR THE
MID AND LATE AFTERNOON. IN THE NORTHEAST WHERE THE MIXING WILL BE
DEEPEST...A FEW LIGHT SHOWERS WILL BE POSSIBLE NEAR THE END OF THE
PERIOD.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...SMITH
LONG TERM....CTN
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1159 AM EDT SAT APR 21 2012
.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE WEST TODAY...THEN CROSS THE
REGION TONIGHT. ANOTHER LOW WILL LIFT NORTH ALONG THE COAST
SUNDAY...THEN TRACK SOUTHWEST OF THE REGION MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...LATEST HRRR CONTINUES TO DELAY THE ONSET OF THE STEADIER
RAINFALL INTO THE NW CWA UNTIL LATE AFTERNOON. CURRENT RADAR
CONFIRMS THIS WITH LITTLE IN THE WAY OF ANY PRECIP AT TIME.
THEREFORE...HAVE DECREASED THE CHANCE OF PRECIPITATION THROUGH EARLY
AFTERNOON. TEMPERATURES ACROSS THE NORTH HAVE BEEN TRICKY THUS
FAR AS THEY HAVE RISEN QUITE RAPIDLY WHERE THERE ARE BREAKS
HOWEVER AS CLOUDS FILL IN AHEAD THE FRONT TEMPERATURES WILL LEVEL
OFF. SOUTH WIND OFF THE GULF OF MAINE WILL HOLD TEMPERATURES DOWN
ALONG THE COAST THUS LOWERED HIGHS HERE.
PREVIOUS DISCUSSION... A FRONTAL BOUNDARY LOCATED
ACROSS NORTHERN MAINE THIS MORNING WILL BEGIN TO SINK SOUTH THIS
AFTERNOON WHILE LOW PRESSURE APPROACHES FROM THE WEST. THE BEST
CHANCES FOR RAIN TODAY WILL OCCUR ACROSS NORTHERN/NORTHWESTERN
PORTIONS OF THE FORECAST AREA. AFTER MORNING SHOWERS...RAIN
CHANCES WILL INCREASE DOWNEAST THIS AFTERNOON WITH THE APPROACH OF
THE LOW AND FRONT. THE LOW WILL CROSS THE FORECAST AREA
TONIGHT...DRAWING THE COLD FRONT SOUTH OF THE REGION. THE LOW AND
FRONT WILL BRING RAIN TO THE ENTIRE FORECAST AREA TONIGHT. ACROSS
NORTHERN/NORTHWESTERN PORTIONS OF THE FORECAST AREA...ENOUGH COLD
AIR COULD BE DRAWN SOUTHWARD TO ALLOW A RAIN/SNOW MIX TO DEVELOP
LATER TONIGHT THOUGH LITTLE OR NO SNOW ACCUMULATION IS EXPECTED.
HIGH TEMPERATURES ACROSS NORTHERN PORTIONS OF THE FORECAST AREA
TODAY WILL BE DEPENDENT ON THE LOCATION OF THE FRONTAL BOUNDARY
WITH READINGS GENERALLY RANGING THROUGH THE 50S. ACROSS
CENTRAL/INTERIOR DOWNEAST PORTIONS OF THE FORECAST AREA HIGH
TEMPERATURES ARE EXPECTED TO RANGE FROM AROUND 60 TO THE LOWER
60S. COOLER TEMPERATURES WILL OCCUR ALONG THE DOWNEAST COAST WHERE
ONSHORE WINDS WILL HELP KEEP TEMPERATURES IN THE MID TO UPPER 50S.
LOW TEMPERATURES TONIGHT ARE EXPECTED TO RANGE FROM THE MID TO
UPPER 30S NORTH...TO THE LOWER TO MID 40S DOWNEAST.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
EXPECT INITIAL AREA OF LOW PRESSURE MOVING NORTHEAST INTO
MARITIMES AND AWAY FROM THE REGION AT THE BEGINNING OF THIS
PERIOD. TRAILING COLD FRONT WILL BECOME STATIONARY OVER THE GULF
OF MAINE LATE SUNDAY AS WEAK HIGH PRESSURE BRIEFLY BUILDS IN FROM
WEST BEHIND THE FRONT. A SECOND AREA OF LOW PRESSURE WILL MOVE
NORTHWARD ALONG THE FRONT SUNDAY EVENING SPREADING MORE
PRECIPITATION ACROSS THE FORECAST AREA. THIS SYSTEM WILL MOVE
NORTHWARD AND PASS TO THE WEST OF NEW ENGLAND LATE MONDAY. MOST
OPERATIONAL RUNS AND INDIVIDUAL GFS ENSEMBLE MEMBERS NOW SUPPORT
THIS WESTERLY TRACK. WITH STRONG HIGH PRESSURE POSITIONED TO THE
NORTH EXPECT WINDY CONDITIONS SUNDAY NIGHT INTO MONDAY. ALSO WITH
LOW LEVEL COLD AIR DRAINAGE IN NORTHEAST FLOW COULD BE SOME MIXED
PRECIPITATION FAR NORTH SUNDAY NIGHT BUT EXPECT MOST PRECIPITATION
IN LIQUID FORM. HAVE BLENDED GFS40...NAM12 AND SREF FOR POPS AND
QPF. FOR WIND WILL BLEND THE NAM12 AND GMOS. HAVE USED 135 PERCENT
OF SUSTAINED WIND FOR GUSTS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
INTENSE LOW PRESSURE GRADUALLY WEAKENS MONDAY NIGHT INTO TUESDAY
AND MOVES NORTH INTO WESTERN QUEBEC PROVINCE. EXPECT COLDER AIR TO
FILTER IN BEHIND UPPER 500 MILLIBAR TROUGH DURING THE DAY
WEDNESDAY. ANOTHER AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP OFF
THE MID ATLANTIC STATES WEDNESDAY NIGHT THEN MOVE NORTHWARD INTO
GULF OF MAINE LATE THURSDAY. WITH COLDER AIR IN PLACE COULD BE
SOME SNOW/MIXED PRECIPITATION WITH THIS SYSTEM NORTH BUT RIGHT NOW
EXPECT MOSTLY LIQUID. WILL INITIALIZE GRIDS WITH GMOS. HAVE
ADJUSTED POPS...MINIMUM TEMPERATURES AND WIND GRIDS.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: OCCASIONAL MVFR CONDITIONS ARE EXPECTED ACROSS THE REGION
TODAY. MVFR/IFR CONDITIONS ARE EXPECTED ACROSS THE REGION TONIGHT.
SHORT TERM: IFR/MVFR CONDITIONS ARE POSSIBLE SUNDAY THROUGH
WEDNESDAY.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS REMAINS IN
EFFECT FOR MUCH OF THE WATERS...WITH THE EXCEPTION OF THE
INTRACOASTAL WATERS...TODAY THROUGH TONIGHT. VISIBILITIES WILL BE
REDUCED IN ANY SHOWERS OR RAIN TODAY...WITH RAIN AND PATCHY FOG
TONIGHT.
SHORT TERM: HAVE USED A BLEND OF NAM12 AND GFS40 SUNDAY AND MONDAY
THEN TRANSITION TO GMOS WINDS. FOR WAVES HAVE USED THE WNA/4. LONG
SOUTHERLY FETCH IN PLACE GULF OF MAINE SOUTHWARD SUNDAY AND MONDAY
WITH INTENSE LOW PRESSURE WEST OF NEW ENGLAND AND STRONG HIGH TO
EAST. SO EXPECT EXTENDED PERIOD OF LONG PERIOD WAVE TO PERSIST
THROUGH THIS FORECAST PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM EDT SUNDAY
FOR ANZ050-051.
&&
$$
NEAR TERM...DUDA/NORCROSS
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...DUDA/NORCROSS
MARINE...DUDA/NORCROSS/MIGNONE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1021 AM EDT SAT APR 21 2012
.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE WEST TODAY...THEN CROSS THE
REGION TONIGHT. ANOTHER LOW WILL LIFT NORTH ALONG THE COAST
SUNDAY...THEN TRACK SOUTHWEST OF THE REGION MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...HAVE UPDATED THE FORECAST TO BACK UP THE TIMING OF THE
STEADIER RAIN UNTIL LATER THIS AFTERNOON. LATEST HRRR INDICATING
THAT THE STEADIER RAIN WONT MAKE IT INTO THE FA UNTIL LATER THIS
AFTERNOON AND ONLY EXPECTING SCT SHOWERS UNTIL THEN. HAVE ALSO
INCLUDED PATCHY FOG FOR THE COAST.
PREVIOUS DISCUSSION...
A FRONTAL BOUNDARY LOCATED ACROSS NORTHERN MAINE THIS MORNING
WILL BEGIN TO SINK SOUTH THIS AFTERNOON WHILE LOW PRESSURE
APPROACHES FROM THE WEST. THE BEST CHANCES FOR RAIN TODAY WILL
OCCUR ACROSS NORTHERN/NORTHWESTERN PORTIONS OF THE FORECAST AREA.
AFTER MORNING SHOWERS...RAIN CHANCES WILL INCREASE DOWNEAST THIS
AFTERNOON WITH THE APPROACH OF THE LOW AND FRONT. THE LOW WILL
CROSS THE FORECAST AREA TONIGHT...DRAWING THE COLD FRONT SOUTH OF
THE REGION. THE LOW AND FRONT WILL BRING RAIN TO THE ENTIRE
FORECAST AREA TONIGHT. ACROSS NORTHERN/NORTHWESTERN PORTIONS OF
THE FORECAST AREA...ENOUGH COLD AIR COULD BE DRAWN SOUTHWARD TO
ALLOW A RAIN/SNOW MIX TO DEVELOP LATER TONIGHT THOUGH LITTLE OR NO
SNOW ACCUMULATION IS EXPECTED. HIGH TEMPERATURES ACROSS NORTHERN
PORTIONS OF THE FORECAST AREA TODAY WILL BE DEPENDENT ON THE
LOCATION OF THE FRONTAL BOUNDARY WITH READINGS GENERALLY RANGING
THROUGH THE 50S. ACROSS CENTRAL/INTERIOR DOWNEAST PORTIONS OF THE
FORECAST AREA HIGH TEMPERATURES ARE EXPECTED TO RANGE FROM AROUND
60 TO THE LOWER 60S. COOLER TEMPERATURES WILL OCCUR ALONG THE
DOWNEAST COAST WHERE ONSHORE WINDS WILL HELP KEEP TEMPERATURES IN
THE MID TO UPPER 50S. LOW TEMPERATURES TONIGHT ARE EXPECTED TO
RANGE FROM THE MID TO UPPER 30S NORTH...TO THE LOWER TO MID 40S
DOWNEAST.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
EXPECT INITIAL AREA OF LOW PRESSURE MOVING NORTHEAST INTO
MARITIMES AND AWAY FROM THE REGION AT THE BEGINNING OF THIS
PERIOD. TRAILING COLD FRONT WILL BECOME STATIONARY OVER THE GULF
OF MAINE LATE SUNDAY AS WEAK HIGH PRESSURE BRIEFLY BUILDS IN FROM
WEST BEHIND THE FRONT. A SECOND AREA OF LOW PRESSURE WILL MOVE
NORTHWARD ALONG THE FRONT SUNDAY EVENING SPREADING MORE
PRECIPITATION ACROSS THE FORECAST AREA. THIS SYSTEM WILL MOVE
NORTHWARD AND PASS TO THE WEST OF NEW ENGLAND LATE MONDAY. MOST
OPERATIONAL RUNS AND INDIVIDUAL GFS ENSEMBLE MEMBERS NOW SUPPORT
THIS WESTERLY TRACK. WITH STRONG HIGH PRESSURE POSITIONED TO THE
NORTH EXPECT WINDY CONDITIONS SUNDAY NIGHT INTO MONDAY. ALSO WITH
LOW LEVEL COLD AIR DRAINAGE IN NORTHEAST FLOW COULD BE SOME MIXED
PRECIPITATION FAR NORTH SUNDAY NIGHT BUT EXPECT MOST PRECIPITATION
IN LIQUID FORM. HAVE BLENDED GFS40...NAM12 AND SREF FOR POPS AND
QPF. FOR WIND WILL BLEND THE NAM12 AND GMOS. HAVE USED 135 PERCENT
OF SUSTAINED WIND FOR GUSTS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
INTENSE LOW PRESSURE GRADUALLY WEAKENS MONDAY NIGHT INTO TUESDAY
AND MOVES NORTH INTO WESTERN QUEBEC PROVINCE. EXPECT COLDER AIR TO
FILTER IN BEHIND UPPER 500 MILLIBAR TROUGH DURING THE DAY
WEDNESDAY. ANOTHER AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP OFF
THE MID ATLANTIC STATES WEDNESDAY NIGHT THEN MOVE NORTHWARD INTO
GULF OF MAINE LATE THURSDAY. WITH COLDER AIR IN PLACE COULD BE
SOME SNOW/MIXED PRECIPITATION WITH THIS SYSTEM NORTH BUT RIGHT NOW
EXPECT MOSTLY LIQUID. WILL INITIALIZE GRIDS WITH GMOS. HAVE
ADJUSTED POPS...MINIMUM TEMPERATURES AND WIND GRIDS.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: OCCASIONAL MVFR CONDITIONS ARE EXPECTED ACROSS THE REGION
TODAY. MVFR/IFR CONDITIONS ARE EXPECTED ACROSS THE REGION TONIGHT.
SHORT TERM: IFR/MVFR CONDITIONS ARE POSSIBLE SUNDAY THROUGH
WEDNESDAY.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS REMAINS IN
EFFECT FOR MUCH OF THE WATERS...WITH THE EXCEPTION OF THE
INTRACOASTAL WATERS...TODAY THROUGH TONIGHT. VISIBILITIES WILL BE
REDUCED IN ANY SHOWERS OR RAIN TODAY...WITH RAIN AND PATCHY FOG
TONIGHT.
SHORT TERM: HAVE USED A BLEND OF NAM12 AND GFS40 SUNDAY AND MONDAY
THEN TRANSITION TO GMOS WINDS. FOR WAVES HAVE USED THE WNA/4. LONG
SOUTHERLY FETCH IN PLACE GULF OF MAINE SOUTHWARD SUNDAY AND MONDAY
WITH INTENSE LOW PRESSURE WEST OF NEW ENGLAND AND STRONG HIGH TO
EAST. SO EXPECT EXTENDED PERIOD OF LONG PERIOD WAVE TO PERSIST
THROUGH THIS FORECAST PERIOD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 AM EDT SUNDAY
FOR ANZ050-051.
&&
$$
NEAR TERM...DUDA/NORCROSS
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...DUDA/NORCROSS
MARINE...DUDA/NORCROSS/MIGNONE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
652 PM EDT SAT APR 21 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 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 652 PM EDT SAT APR 21 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 MARQUETTE MI
427 PM EDT SAT APR 21 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 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 139 PM EDT SAT APR 21 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 THIS AFTN 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...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GLASGOW MT
844 PM MDT SUN APR 22 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
EVENING UPDATE...
DRY AND PARTLY CLOUDY CONDITIONS ARE EXPECTED TONIGHT. ONLY MINOR
TWEAKING WAS DONE BY APPLYING A WRF AND HRRR MESOSCALE MODEL MASK
TO WINDS AND REAPPLYING THIS WIND FIELD TO OVERNIGHT LOWS. RHS
WILL ALSO HAVE A SLIGHTLY HARDER TIME REBOUNDING OVERNIGHT ACROSS
THE SOUTHERN SECTIONS OF THE CWA THAN FIRST ANTICIPATED. GAH
PREVIOUS SHORT TERM DISCUSSION...
A HIGH PRESSURE AREA OVER THE SOUTHWESTERN STATES CONTINUES TO
ANCHOR A STRONG UPPER LEVEL RIDGE OVER THE WEST. WITH THE AXIS
OVER THE DIVIDE...NORTHEAST MONTANA REMAINS UNDER A NORTHWESTERLY
FLOW ALOFT. ALTHOUGH A PACIFIC TROUGH IS FEEDING MOISTURE THAT IS
RIDING OVER THE TOP OF THE RIDGE...ONLY A FEW HIGH PEAKS HAVE
GENERATED HIGH STRATUS TODAY. THE RESULT HAS BEEN SUNNY SKIES
TODAY.
WITH A CONTINUING INFLUX OF WARMER AIR FROM THE SOUTH...1000MB-
500MB THICKNESS HEIGHTS WHICH BEGIN AT AROUND 550DM TO 560DM AT
00Z MONDAY WILL RAMP UP TO AROUND 570DM ON 00Z TUESDAY. CLEAR
SKIES AND LIGHT WESTERLY WINDS WILL SEE WARM TEMPERATURES FOR
MONDAY. GUIDANCE SUGGESTS HIGHS IN THE HIGH 80S. THE STORM
PREDICTION CENTER PLACES OUR WESTERN ZONES IN THE CONVECTIVE
OUTLOOK FOR MONDAY. THIS SEEMS REASONABLE CONSIDERING THAT WEAK TO
MODERATE CAPE DEVELOPS AND THERE IS A SUBTLE FRONTAL BOUNDARY AND
A WEAK LEE SURFACE TROUGH. SO WILL MAINTAIN SLIGHT CHANCE POPS IN
THE WESTERN ZONES FOR THE AFTERNOON/EVENING FOR THUNDERSTORMS.
MONDAY NIGHT AND TUESDAY WILL BEGIN A CHANGE WHEN A GULF OF ALASKA
LOW DROPS SOUTH WHICH DEPRESSES THE RIDGE. THIS SENDS THE
STATIONARY COLD BOUNDARY SOUTH WHICH MEETS A LEE TROUGH. LAPSE
RATES AND WEAK CAPE SHOULD RESULT IN OVERNIGHT AND MORNING LIGHT
SHOWERS...WITH THE POSSIBILITY OF THUNDER. WITH THICKNESS HEIGHTS
FALLING AND INCREASED CLOUD COVER FROM THE INSTABILITY AND SURFACE
WINDS BECOMING NORTHERLY...MAXIMUM TEMPERATURES WILL NOT BE AS
WARM AS MONDAY. SCT
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
TUESDAY NIGHT INTO WEDNESDAY WILL BRING A WEAK COLD FRONT
THROUGH...CREATING SOME POTENTIAL FOR SHOWERS AND THUNDERSTORMS.
GUSTY EASTERLY WINDS WILL ALSO DEVELOP AS HIGH PRESSURE DROPS
INTO NORTH DAKOTA. WEDNESDAY NIGHT INTO THURSDAY CONDITIONS WILL
DRY OUT AS THE UPPER RIDGE REBOUNDS BACK INTO THE NORTHERN HIGH
PLAINS.
THURSDAY NIGHT INTO SATURDAY NIGHT MODELS ARE NOW IN BETTER
AGREEMENT WITH BRINGING A POTENTIALLY WET AND WINDY UPPER LOW
THROUGH THE REGION. AT THIS POINT FRIDAY LOOKS LIKE THE WETTEST
PERIOD. BIGGEST CHANGES MADE FOR THIS AFTERNOONS PACKAGE WAS TO
TREND UP POPS AND WINDS DURING THIS TIMEFRAME. GILCHRIST
PREVIOUS DISCUSSION...CONTINUED GOOD MODEL AGREEMENT THROUGH MUCH
OF THE PERIOD AS EAST PACIFIC TROF MOVES ONSHORE AND REPLACES
RIDGE ACROSS THE ROCKIES BY LATE IN THE WEEK. AS THE UPPER RIDGE
AXIS SHIFTS FROM WESTERN MONTANA TO THE DAKOTAS LATE IN THE
WEEK...A STRONG LOW LEVEL JET DEVELOPS...STREAMING MOISTURE
NORTHWARD ACROSS THE HIGH PLAINS. WARM AND WINDY CONDITIONS
EXPECTED THURSDAY WITH THE RIDGE AXIS OVER EASTERN MONTANA. AS THE
RIDGE MOVES EAST...A SHORTWAVE LIFTING OUT OF THE GREAT BASIN WILL
SPIN UP A SURFACE LOW SOMEWHERE ALONG THE FRONT RANGE LEE TROF BY
FRIDAY. COOLING ALOFT WILL CREATE ENOUGH INSTABILITY FOR SHOWERS
THROUGH THE WEEKEND AS THE UPPER TROF MOVES LIFTS FROM THE GREAT
BASIN INTO THE PLAINS. EBERT
&&
.AVIATION...
VFR. MOSTLY CLEAR SKIES WITH A FEW HIGH CLOUDS WILL DOMINATE OVER
THE AREA UNTIL MONDAY AFTERNOON OR EVENING WITH UNLIMITED
VISIBILITY. KOLF WILL HAVE NEARLY CALM WINDS OVERNIGHT. KGGW WILL
HAVE A NOCTURNAL SOUTHEAST WIND AROUND 10 KTS TONIGHT WHILE KSDY
AND KGDV HAVE SOUTHERLY WINDS 5 TO 10 KNOTS DUE TO LOCAL EFFECTS.
BY MID MONDAY MORNING WESTERLY WINDS AT 8-12KTS WILL MIX DOWN AND
INCREASE TO AROUND 15 KNOTS IN THE AFTERNOON. ISOLATED SHOWERS AND
THUNDERSTORMS ARE POSSIBLE MONDAY EVENING AND NIGHT AHEAD OF A
COLD FRONT THAT WILL MOVE THROUGH THE AREA TUESDAY MORNING.
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BILLINGS MT
625 PM MDT SUN APR 22 2012
.SHORT TERM...VALID FOR MON AND TUE...
A MINOR UPDATE WAS MADE TO THE EVENING FORECAST IN ORDER TO EXPAND
MENTION OF ISOLATED SHOWERS AND THUNDERSTORMS THROUGH THE PARADISE
VALLEY AND LIVINGSTON...AND A BIT MORE OVER THE FOOTHILLS TOO. THE
CHANGE IS BASED ON RECENT RADAR TRENDS. RUC OBJECTIVE ANALYSES ARE
SHOWING UP TO 500 J/KG OF MLCAPE OVER THE HIGHER TERRAIN...BUT THE
AIR MASS IS QUITE DRY SO WE STILL DO NOT EXPECT MUCH IN THE WAY OF
COVERAGE TO THE EVENING CONVECTION. SCHULTZ
PREVIOUS DISCUSSION...ISSUED AT 329 PM MDT SUN APR 22 2012...
HIGH PRESSURE RIDGE WILL CONTINUE TO BUILD ACROSS THE ENTIRE
FORECAST AREA TONIGHT AND THROUGHOUT THE DAY MONDAY AND INTO
TUESDAY. 500MB HEIGHTS CLIMB TO AROUND 578DM BY MONDAY AFTERNOON.
IN ADDITION...SURFACE HIGH PRESSURE WILL BE SITUATED OVER THE
CENTRAL ROCKIES RESULTING IN SUBSIDENCE AND ALLOWING FOR MOSTLY
SUNNY SKIES AND VERY WARM TEMPERATURES WITH READINGS 20 TO 25
DEGREES ABOVE NORMAL BY MONDAY. RECORD HIGHS SET BACK IN 1943 OF
82 AND 81 DEGREES AT BILLINGS AND SHERIDAN RESPECTIVELY LIKELY
LOOK TO BE BROKEN WITH MILES CITY APPROACHING THE RECORD OF 86
DEGREES. HOWEVER...A FEW WEAK IMPULSES MAY UNDERCUT THE UPPER
RIDGE MONDAY INTO TUESDAY BRINGING A SLIGHT CHANCE FOR A SHOWER
OR THUNDERSTORM WITH THE BEST CHANCES OVER THE MOUNTAIN
LOCATIONS. EXPECT TEMPERATURES TO CLIMB WELL INTO THE 80S ON
MONDAY WITH READINGS A FEW DEGREES COOLER TUESDAY BUT STILL
AROUND THE 80 DEGREE MARK. HOOLEY
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
MODELS CONTINUE TO ADVERTISE A POTENTIALLY SIGNIFICANT CHANGE TO
THE WEATHER PATTERN LATE IN THE WEEK INTO THE WEEKEND. THIS
CHANGE HAS BEEN ON THE MODELS RADAR FOR MANY RUNS NOW...BUT THERE
HAVE BEEN SOME DIFFERENCES ON TIMING IN REGARDS TO PRECIPITATION
POTENTIAL. THE LAST SEVERAL RUNS HAVE BEEN RATHER WET FOR OUR
FORECAST AREA. BOTH THE GFS AND ECMWF WERE PAINTING UPWARDS OF AN
INCH OF QPF OVER PARTS OF SOUTH CENTRAL MONTANA FRIDAY INTO
FRIDAY NIGHT.
THE ECMWF HAS THE WESTERN UPPER TROUGH SPITTING ON THE SOUTH SIDE
AND CUTTING A LOW OFF OVER WYOMING ON FRIDAY. THE LOW FILLS AND
GRADUALLY MOVES EAST SATURDAY. THIS IS A VERY GOOD PRECIPITATION
PATTERN FOR US. THE GFS HAS A SIMILAR SOLUTION BUT CUTS THE UPPER
RIDGE CURRENTLY ON TOP OF US...OFF OVER SOUTH CENTRAL CANADA AND
FORCES A BLOCKING PATTERN WITH MONTANA ON THE COOL AND WET SIDE
OF THIS BLOCK. THE GFS SETS UP A STRONG SURFACE CONVERGENCE ZONE
RIGHT OVER BILLINGS WITH OVER AN INCH OF QPF FRIDAY AND FRIDAY
NIGHT. EITHER WAY...LOOKS LIKE A POSITIVE SCENARIO FOR POPS. ONLY
THING THAT HOLDS ME BACK FROM PUTTING IN LIKELY POPS ACROSS MOST
OF THE WESTERN AND CENTRAL ZONES IS MODEL TO MODEL CONTINUITY.
FOR EXAMPLE...THE GFS YESTERDAY WAS FARTHER WEST WITH THE
DYNAMICS. IF CURRENT TREND CONTINUES...SHOULD BE ABLE TO RAISE
POPS TO LIKELY QUITE EASILY...EVEN THIS FAR OUT. THIS LOOKS TO BE
A GOOD PRECIPITATION PATTERN FOR US.
WEDNESDAY AND THURSDAY WILL BE WARM AHEAD OF THE UPPER LOW WITH
AN INCREASING CHANCE OF CONVECTION. UPPER RIDGE AXIS IS PROGGED
TO BE CENTERED OVER EASTERN MONTANA ON WEDNESDAY...SO THAT
SUBSIDENCE SHOULD SQUELCH CONVECTION CHANCES. THURSDAY WOULD BE A
BETTER PATTERN WITH THE SOUTHERN UPPER LOW PUSHING INTO NORTHERN
COLORADO WITH UPPER DIFFLUENT FLOW INCREASING. EASTERLY LOW LEVEL
WINDS AND INCREASING CLOUD COVER SHOULD COOL THINGS DOWN EACH OF
THESE DAYS. ALREADY DISCUSSED THE POTENTIAL FOR SOAKING RAINS
FRIDAY AND FRIDAY NIGHT. LOWERED HIGHS QUITE A BIT FOR
FRIDAY...AND MAY HAVE TO GO LOWER IF PRECIPITATION STARTS EARLY.
PRECIPITATION CHANCES TAPER OFF LATE FRIDAY NIGHT INTO SATURDAY
AS DYNAMICS SHIFT AWAY. TWH
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH TONIGHT. AN ISOLATED SHOWER
OR THUNDERSTORM IS POSSIBLE IN AND NEAR THE MOUNTAINS THIS EVENING.
TWH
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 052/086 056/081 051/074 048/077 048/060 039/057 038/060
01/U 22/T 21/B 12/T 45/W 54/W 32/W
LVM 045/081 049/075 045/070 041/070 041/052 034/053 032/055
23/T 33/T 32/T 23/T 46/W 33/W 42/W
HDN 045/086 053/082 046/076 046/079 046/065 039/059 037/062
00/U 22/T 21/B 12/T 35/W 54/W 22/W
MLS 047/087 056/084 050/073 044/072 044/062 040/058 038/062
00/U 22/T 21/B 11/B 35/W 44/W 22/W
4BQ 043/085 051/083 047/073 044/072 043/064 038/057 036/060
00/U 12/T 21/B 11/B 44/W 54/W 32/W
BHK 040/083 052/082 049/070 040/065 039/058 036/056 035/059
00/U 12/T 21/B 11/N 24/W 44/W 32/W
SHR 043/084 051/080 048/070 044/074 043/063 037/055 035/058
01/U 22/T 21/B 12/T 45/W 55/W 33/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
156 PM EDT SAT APR 21 2012
.SYNOPSIS...
A COLD FRONT WILL PUSH THROUGH THE AREA TODAY BRINGING COOLER AIR
AND RAIN TO THE AREA. THE FRONT WILL STALL ALONG THE EAST COAST
TONIGHT. A INTENSE LOW WILL MOVE UP THE EAST COAST SUNDAY, AND
INTO UPSTATE NEW YORK MONDAY. THIS LOW WILL SPREAD RAIN BACK INTO
THE AREA SUNDAY NIGHT INTO MONDAY NIGHT. COLD AIR OVER WESTERN AND
CENTRAL NEW YORK AND NORTHERN PENNSYLVANIA, MAY SWITCH THE RAIN
TO SNOW AND BRING THOSE AREAS A FEW INCHES OF ACCUMULATION.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...A COLD FRONT CONTINUES TO MARCH ACROSS THE CWA ATTM
WITH THE MAIN SHIELD OF RAIN BEHIND THE FRONT...AND ONLY ISOLATED
SHOWERS JUST AHEAD OF IT. TEMP CHANGES ARE SHARP WITH KITH AND
KSYR NOW INTO THE UPPER 40S BEHIND THE FRONT...WITH LOWER 60S AT
TOWANDA...BINGHAMTON...AND HAMILTON JUST AHEAD OF THE FRONT.
EXPECT TEMPS TO COOL BACK INTO THE 40S AND 50S WITH THE FROPA THIS
AFTERNOON EXCEPT FOR THE FAR SE WHICH WON`T SEE THE FRONT UNTIL
LATER IN THE DAY.
TRIMMED BACK RAIN CHANCES A BIT ON THE FRONT EDGE. IT APPEARS OUR
MOST STEADY RAIN WILL HANG ACROSS THE WESTERN PART OF THE CWA
THROUGH EARLY AFTERNOON AND NOT MAKE HUGE PROGRESS EAST UNTIL
LATER TODAY. WE STILL REMAIN IN SEE TEXT ACROSS THE EXTREME FAR
SOUTHEAST FOR SEVERE WEATHER. A MARINE LAYER WHICH IS IN THE
PROCESS OF BURNING OFF WILL PUT A DAMPER ON OUR CHANCES. THIS IS
SHOWN NICELY BY THE RUC SHOWING CAPES ONLY IN THE 100 - 300 J/KG
RANGE THIS AFTERNOON AT MSV. THE NAM IS A BIT HIGHER BUT BOTH
MODELS SHOW A BIT OF A CAP BETWEEN 5000 AND 1000 FEET...WHICH WILL
FURTHER LIMIT ACTIVITY. IF WE SEE ANY STORMS FORM...THE BEST
CHANCE WILL BE ACROSS OUR EXTREME FAR SOUTHEAST AND THE
POTENTIAL WILL MAINLY BE FOR WIND WITH AN INVERTED V SOUNDING.
IT APPEARS OUR CHANCES FOR RAIN GO DOWN SHARPLY AFTER 06Z TONIGHT
SO I MADE THE ENTIRE AREA DRY LATE TONIGHT INTO EARLY SUNDAY TO
SHOW A BREAK IN BETWEEN OUR TWO SYSTEMS. MORE ON THE NEXT SYSTEM
LATER THIS AFTERNOON.
4 AM UPDATE... BIG CHANGES TO OUR RECENT MILD DRY PATTERN.
FIRST WITH A COLD FRONT AND RAIN SHOWERS TODAY THEN A STACKED LOW
WITH SNOW AND RAIN FOR SUNDAY TO TUESDAY.
ATTM A NE TO SW COLD ANAFRONT IS ACROSS NRN AND WRN NY. THIS WILL
MOVE SLOWLY EAST TODAY AND TO THE EAST COAST TONIGHT. SHOWERS
BEHIND THE FRONT WILL MOVE INTO CENTRAL NY THIS MORNING THEN INTO
NE PA AND THE CATSKILLS THIS AFTN. HIGHS WILL BE JUST AHEAD OF THE
SFC FRONT. THE HIGHEST TEMPS WILL BE ACROSS THE FAR SE WITH U60S
AND L70S. IN THIS AREA SOME ATLANTIC MOISTURE CAUSING LOW CLOUDS
BUT THIS WILL EXIT SO THAT SOME SUN IS POSSIBLE MIDDAY. ALSO MODEST
LOW LEVEL INSTABILITY COULD CAUSE A THUNDERSTORM THIS AFTN.
IN CENT NY TEMPERATURES WILL NOT BE WARM ENOUGH FOR THUNDERSTORMS.
THIS AFTN TEMPERATURES FALL THROUGH THE 40S AND INTO THE 30S
TONIGHT. IN THE SE TEMPS FALL INTO THE 40S.
SHOWERS WILL END IN NY LATE TODAY AND IN NE PA AND SULLIVAN COUNTY
NY THIS EVENING. RAINFALL BEHIND THE FRONT WILL BE A QUARTER TO
HALF AN INCH. POSSIBLY SOME HIGHER AMOUNTS IN THUNDERSTORMS. WITH
IT BEING SO DRY THIS MONTH LITTLE WILL RUN OFF.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
4 AM UPDATE...
A STRONG STORM WILL MOVE OUT OF THE GULF OF MEXICO AND UP THE EAST
COAST SUNDAY. THE SFC LOW INTENSIFIES THE WHOLE WAY. A DEEP UPPER
LEVEL TROF CLOSES OFF OVER THE OHIO VALLEY CAUSING THE SFC LOW TO
TURN NORTH THEN NE INTO UPSTATE NY. MONDAY NIGHT THE UPPER AND
SURFACE LOWS BECOME STACKED AND MOVE SLOWLY NORTH INTO SE CANADA.
MODELS IN BETTER AGREEMENT NOW WITH A SFC TRACK UP THE HUDSON
VALLEY. CENTRAL NY AND NE PA COULD GET 1 TO 2 INCHES LIQUID WITH
THIS STORM. RAIN MOVES IN AHEAD OF THE LOW LATE SUNDAY AND SUNDAY
NIGHT TO COVER THE WHOLE AREA. TEMPERATURES ARE WARM ENOUGH TO
START AS RAIN BUT ACROSS THE HIGHER TERRAIN ESPECIALLY IN NY WEST
OF THE CATSKILLS IT WILL MIX WITH SNOW. THE FURTHER WEST YOU GO
THE COLDER IT WILL BE SO THE COLDEST AIR WILL BE IN STEUBEN
COUNTY. PRECIP SHOULD CHANGE TO JUST SNOW LATE SUNDAY NIGHT.
MIDDAY MONDAY DAYTIME HEATING WILL CAUSE MOST OF THE PRECIP TO
CHANGE TO RAIN BEFORE CHANGING BACK TO A MIX OR SNOW MONDAY NIGHT.
LOW LEVELS CLOSE TO FREEZING SO ELEVATION WILL BE A FACTOR TOO.
SURFACE TEMPERATURES MOSTLY IN THE 30S SUNDAY NIGHT TO MONDAY
NIGHT. WITH THE WARMEST AIR OVER THE CATSKILLS AND POCONOS SNOW
AMOUNTS THERE ARE EXPECTED TO BE LESS THAN AN INCH. HIGH TEMPS
SUNDAY IN THE 50S AND AROUND 50 MONDAY. THE HIGHEST AMOUNTS OF
SEVERAL INCHES WILL BE ACROSS THE HIGHER TERRAIN IN CORTLAND
COUNTY...THE CENTRAL SOUTHERN TIER AND FINGER LAKES OF NY...AND
BRADFORD COUNTY PA. IN WESTERN STEUBEN COUNTY 6 TO 12 IS POSSIBLE.
EVEN WITH 1 TO 2 INCHES OF LIQUID RIVERS ARE NOT EXPECTED TO
FLOOD. VERY LOW RIVER LEVELS FOR APRIL. WILL NEED TO WATCH THE
DELAWARE BASINS SUNDAY NIGHT TO MONDAY WITH UP TO ONE INCH EACH 6
HOURS WITH TOTALS AROUND 3 INCHES. THIS AMOUNT WILL CAUSE RAPID
RISES ON THE STREAMS AND CREEKS. ONCE THE SFC LOW PASSES MONDAY
RAIN WILL END IN MOST OF NE PA AND THE CATSKILLS FOR MONDAY NIGHT.
WRAPAROUND MIXED PRECIP WILL CONTINUE IN CENTRAL AND WRN NY MONDAY
TO TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UPR LOW CONTS TO LFT SLOWLY NORTH AT THE BEGINNING OF THE PD BUT
THE FCST AREA REMAINS IN A BROAD UPR TROF WITH COOL AND DAMP
CONDS. SHRT WV DROPS INTO THE TROF LATE THU AND EARLY FRI WHICH
WILL INCRS THE CHANCE OF SHWRS. DRIER AIR ARRIVES FOR SAT BUT
MODELS SHOW A WRM FNT DVLPG OVER THE OH VLY AND PUSHING NORTH.
THIS SHD NOT GENERATE MUCH PCPN...BUT CONTD CLDS SEEM LIKELY WITH
THE FNT.
TEMPS WILL GNRLY BE BLOW NRML THU THE PD...LEADING TO A CHANCE OF
SOME SNOW MIXED IN THE WITH SHWRS...PRIMARILY LTR AT NGT AND EARLY
MRNG AS THE TEMPS HIT THEIR LOWS. NOT ENUF COLD AIR FOR ANY CNCRN
FOR ACCUMS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
COLD FNT CUTTING THRU THE ERN AREAS ATTM WITH ONLY AVP STILL ON
THE WRM SIDE. THERE IS THE THREAT OF A TRW FOR THENEXT FEW HRS AT
AVP UNTIL THE FNT PASSES ARND 22Z. BHD THE FNT IS A BRK BUT BACK
IN THE COLD AIR ABAND OF MAINLY LGT PCPN WITH MVFR AND IFR CIGS
AND VSBYS. PCPN SHD END IN MOPST AREAS SHRTLY AFT 00Z...BUT VERY
STABLE AND WET SNDG WILL KEEP LOW CLDS AND SOME VSBY RESTRICTIONS
IN THRU THE NGT. DRIER AIR BEGINS TO PUSH IN AFT 12Z SUN...ESP IN
THE NORTH SO HAVE FCSTD RISING CIGS AND VSBYS FOR THE END OF THE
TAF PD. SW WINDS AHD OF THE FNT AT AVP OTRW A LGT NLY FLOW IS
XPCTD BHD THE FNT THRU THE END OF THE PD.
.OUTLOOK...
SUN AFTN...MAINLY VFR.
SUN NGT-MON...MVFR AND IFR IN RA.
TUE INTO THU...VFR/MVFR BUT ISTLD IFR PSBL IN SCT RAIN AND NSOW
SHWRS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TAC
NEAR TERM...HEDEN/TAC
SHORT TERM...TAC
LONG TERM...DGM
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1000 AM EDT SAT APR 21 2012
.SYNOPSIS...
A COLD FRONT WILL PUSH THROUGH THE AREA TODAY BRINGING COOLER AIR
AND RAIN TO THE AREA. THE FRONT WILL STALL ALONG THE EAST COAST
TONIGHT. A INTENSE LOW WILL MOVE UP THE EAST COAST SUNDAY, AND
INTO UPSTATE NEW YORK MONDAY. THIS LOW WILL SPREAD RAIN BACK INTO
THE AREA SUNDAY NIGHT INTO MONDAY NIGHT. COLD AIR OVER WESTERN AND
CENTRAL NEW YORK AND NORTHERN PENNSYLVANIA, MAY SWITCH THE RAIN
TO SNOW AND BRING THOSE AREAS A FEW INCHES OF ACCUMULATION.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...A COLD FRONT CONTINUES TO MARCH ACROSS THE CWA ATTM
WITH THE MAIN SHIELD OF RAIN BEHIND THE FRONT...AND ONLY ISOLATED
SHOWERS JUST AHEAD OF IT. TEMP CHANGES ARE SHARP WITH KITH AND
KSYR NOW INTO THE UPPER 40S BEHIND THE FRONT...WITH LOWER 60S AT
TOWANDA...BINGHAMTON...AND HAMILTON JUST AHEAD OF THE FRONT.
EXPECT TEMPS TO COOL BACK INTO THE 40S AND 50S WITH THE FROPA THIS
AFTERNOON EXCEPT FOR THE FAR SE WHICH WON`T SEE THE FRONT UNTIL
LATER IN THE DAY.
TRIMMED BACK RAIN CHANCES A BIT ON THE FRONT EDGE. IT APPEARS OUR
MOST STEADY RAIN WILL HANG ACROSS THE WESTERN PART OF THE CWA
THROUGH EARLY AFTERNOON AND NOT MAKE HUGE PROGRESS EAST UNTIL
LATER TODAY. WE STILL REMAIN IN SEE TEXT ACROSS THE EXTREME FAR
SOUTHEAST FOR SEVERE WEATHER. A MARINE LAYER WHICH IS IN THE
PROCESS OF BURNING OFF WILL PUT A DAMPER ON OUR CHANCES. THIS IS
SHOWN NICELY BY THE RUC SHOWING CAPES ONLY IN THE 100 - 300 J/KG
RANGE THIS AFTERNOON AT MSV. THE NAM IS A BIT HIGHER BUT BOTH
MODELS SHOW A BIT OF A CAP BETWEEN 5000 AND 1000 FEET...WHICH WILL
FURTHER LIMIT ACTIVITY. IF WE SEE ANY STORMS FORM...THE BEST
CHANCE WILL BE ACROSS OUR EXTREME FAR SOUTHEAST AND THE
POTENTIAL WILL MAINLY BE FOR WIND WITH AN INVERTED V SOUNDING.
IT APPEARS OUR CHANCES FOR RAIN GO DOWN SHARPLY AFTER 06Z TONIGHT
SO I MADE THE ENTIRE AREA DRY LATE TONIGHT INTO EARLY SUNDAY TO
SHOW A BREAK IN BETWEEN OUR TWO SYSTEMS. MORE ON THE NEXT SYSTEM
LATER THIS AFTERNOON.
4 AM UPDATE... BIG CHANGES TO OUR RECENT MILD DRY PATTERN.
FIRST WITH A COLD FRONT AND RAIN SHOWERS TODAY THEN A STACKED LOW
WITH SNOW AND RAIN FOR SUNDAY TO TUESDAY.
ATTM A NE TO SW COLD ANAFRONT IS ACROSS NRN AND WRN NY. THIS WILL
MOVE SLOWLY EAST TODAY AND TO THE EAST COAST TONIGHT. SHOWERS
BEHIND THE FRONT WILL MOVE INTO CENTRAL NY THIS MORNING THEN INTO
NE PA AND THE CATSKILLS THIS AFTN. HIGHS WILL BE JUST AHEAD OF THE
SFC FRONT. THE HIGHEST TEMPS WILL BE ACROSS THE FAR SE WITH U60S
AND L70S. IN THIS AREA SOME ATLANTIC MOISTURE CAUSING LOW CLOUDS
BUT THIS WILL EXIT SO THAT SOME SUN IS POSSIBLE MIDDAY. ALSO MODEST
LOW LEVEL INSTABILITY COULD CAUSE A THUNDERSTORM THIS AFTN.
IN CENT NY TEMPERATURES WILL NOT BE WARM ENOUGH FOR THUNDERSTORMS.
THIS AFTN TEMPERATURES FALL THROUGH THE 40S AND INTO THE 30S
TONIGHT. IN THE SE TEMPS FALL INTO THE 40S.
SHOWERS WILL END IN NY LATE TODAY AND IN NE PA AND SULLIVAN COUNTY
NY THIS EVENING. RAINFALL BEHIND THE FRONT WILL BE A QUARTER TO
HALF AN INCH. POSSIBLY SOME HIGHER AMOUNTS IN THUNDERSTORMS. WITH
IT BEING SO DRY THIS MONTH LITTLE WILL RUN OFF.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
4 AM UPDATE...
A STRONG STORM WILL MOVE OUT OF THE GULF OF MEXICO AND UP THE EAST
COAST SUNDAY. THE SFC LOW INTENSIFIES THE WHOLE WAY. A DEEP UPPER
LEVEL TROF CLOSES OFF OVER THE OHIO VALLEY CAUSING THE SFC LOW TO
TURN NORTH THEN NE INTO UPSTATE NY. MONDAY NIGHT THE UPPER AND
SURFACE LOWS BECOME STACKED AND MOVE SLOWLY NORTH INTO SE CANADA.
MODELS IN BETTER AGREEMENT NOW WITH A SFC TRACK UP THE HUDSON
VALLEY. CENTRAL NY AND NE PA COULD GET 1 TO 2 INCHES LIQUID WITH
THIS STORM. RAIN MOVES IN AHEAD OF THE LOW LATE SUNDAY AND SUNDAY
NIGHT TO COVER THE WHOLE AREA. TEMPERATURES ARE WARM ENOUGH TO
START AS RAIN BUT ACROSS THE HIGHER TERRAIN ESPECIALLY IN NY WEST
OF THE CATSKILLS IT WILL MIX WITH SNOW. THE FURTHER WEST YOU GO
THE COLDER IT WILL BE SO THE COLDEST AIR WILL BE IN STEUBEN
COUNTY. PRECIP SHOULD CHANGE TO JUST SNOW LATE SUNDAY NIGHT.
MIDDAY MONDAY DAYTIME HEATING WILL CAUSE MOST OF THE PRECIP TO
CHANGE TO RAIN BEFORE CHANGING BACK TO A MIX OR SNOW MONDAY NIGHT.
LOW LEVELS CLOSE TO FREEZING SO ELEVATION WILL BE A FACTOR TOO.
SURFACE TEMPERATURES MOSTLY IN THE 30S SUNDAY NIGHT TO MONDAY
NIGHT. WITH THE WARMEST AIR OVER THE CATSKILLS AND POCONOS SNOW
AMOUNTS THERE ARE EXPECTED TO BE LESS THAN AN INCH. HIGH TEMPS
SUNDAY IN THE 50S AND AROUND 50 MONDAY. THE HIGHEST AMOUNTS OF
SEVERAL INCHES WILL BE ACROSS THE HIGHER TERRAIN IN CORTLAND
COUNTY...THE CENTRAL SOUTHERN TIER AND FINGER LAKES OF NY...AND
BRADFORD COUNTY PA. IN WESTERN STEUBEN COUNTY 6 TO 12 IS POSSIBLE.
EVEN WITH 1 TO 2 INCHES OF LIQUID RIVERS ARE NOT EXPECTED TO
FLOOD. VERY LOW RIVER LEVELS FOR APRIL. WILL NEED TO WATCH THE
DELAWARE BASINS SUNDAY NIGHT TO MONDAY WITH UP TO ONE INCH EACH 6
HOURS WITH TOTALS AROUND 3 INCHES. THIS AMOUNT WILL CAUSE RAPID
RISES ON THE STREAMS AND CREEKS. ONCE THE SFC LOW PASSES MONDAY
RAIN WILL END IN MOST OF NE PA AND THE CATSKILLS FOR MONDAY NIGHT.
WRAPAROUND MIXED PRECIP WILL CONTINUE IN CENTRAL AND WRN NY MONDAY
TO TUESDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
4 AM SAT UPDATE... NO CHANGES TO THE EXTENDED GRIDS ATTM.
00Z SAT NWP SUITE REMAINS IN FAIRLY GOOD AGREEMENT ON THE
LARGE-SCALE...WITH AN AMPLIFIED PATN IN PLACE TO START THE
PD...FEATURING A DEEP SERN CANADIAN/ERN CONUS TROUGH AXIS...HELD IN
PLACE BY HIGHER LAT BLOCKING EXTENDING INTO GREENLAND...AND ALSO A
WRN CONUS RIDGE. THERE IS DECENT CONSENSUS THAT MID TO UPR-LVL
HEIGHTS WILL GRADUALLY RISE OVER THE ERN U.S. BY LATER NEXT
WEEK...BUT THAT THE PRIMARY TROUGH AXIS WILL REMAIN IN PLACE. AS A
RESULT...WE CAN EXPECT A CHILLY PD OVERALL...WITH TEMPS AVERAGING
BELOW CLIMATOLOGICAL NORMS FOR LATE APRIL.
DAILY WX-WISE...MOIST CYCLONIC FLOW UNDERNEATH THE ABV MENTIONED
TROUGH FEATURE WILL KEEP OUR WX UNSETTLED THROUGH AT LEAST WED...AND
POSSIBLY INTO THU...WITH -SHRA IN THE FCST. BLYR TEMPS CONTINUE TO
LOOK COLD ENOUGH FOR -SHSN TO MIX DURG THE NIGHTTIME/EARLY MRNG
HRS...SPCLY OVER THE HIGHER TERRAIN. BY FRI...THERE IS SOME
INDICATION THAT DRIER AIR MAY PUSH DOWN INTO NY/PA OUT OF ERN
CANADA...AS A SFC RIDGE BUILDS SWD. TEMPS...THOUGH...SHOULD REMAIN
ON THE COOL SIDE.
PREVIOUS DISCUSSION...
MAJOR STORM WILL BE WINDING DOWN DURING THE BEGINNING OF THE
EXTENDED PERIOD. THE PERIOD BEGINS WITH VERTICALLY STACKED LOW
PRESSURE NEAR LAKE ONTARIO MONDAY NIGHT. MOISTURE WRAPPING AROUND
THIS SYSTEM WILL SPREAD SOME LIGHT RAIN AND SNOW SHOWERS ACROSS
THE AREA MONDAY NIGHT INTO TUESDAY EVENING ALONG WITH GUSTY
WESTERLY WINDS. DRYER... COOL WEATHER WILL FOLLOW IN THE WAKE OF
THIS SYSTEM TUESDAY NIGHT. OVERALL PATTERN LOOKS CONTINUED COOL
WEDNESDAY INTO SATURDAY. A CLIPPER SYSTEM COULD MOVE ACROSS THE
AREA AT SOME TIME DURING THIS TIME WITH A PERIOD OF SHOWERS.
TEMPERATURES WILL BE BELOW NORMAL WITH HIGHS GENERALLY IN THE
LOWER TO MID 50S AND LOWS MOSTLY IN THE 30S.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
12Z UPDATE... VFR SHOULD HANG ON A LTL LONGER...BUT RESTRICTIONS
ARE COMING INTO THE AREA THIS MRNG...AND WE SHOULD SEE DETERIORATING
CONDS FOR THE MAJORITY OF OUR TAF SITES BY 12-15Z. OUR BEST GUESS AT
THIS PT IS LOW MVFR TO SOME IFR...SPCLY THIS AFTN...WHEN STEADIER
-RA MOVES IN. THE MOST PROBABLE SITE TO SEE CONDS FALL BELOW ALT
MINS IS KITH.
THE EXCEPTION TO ALL OF THIS IS KAVP...WHERE VFR SHOULD PERSIST FOR A
GOOD PTN OF THE DAY...AS IT WILL TAKE THE APPROACHING FRNTL BNDRY
AND AXIS OF MOIST MUCH LONGER TO REACH HERE. HOWEVER...EVEN
HERE...MVFR SHOULD ULTIMATELY DEVELOP BY LATE AFTN...CONTINUING
INTO THE EVE. THERE COULD BE SCTD SHRA DEVELOPMENT ACRS NE PA THIS
AFTN...JUST PRIOR TO FROPA...WITH EVEN A LOW PROBABILITY FOR TSRA.
AT THIS JUNCTURE...THE TSRA THREAT DOESN`T YET JUSTIFY INCLUSION
IN THE TERMINAL FCST.
S TO SW WINDS EARLY THIS MRNG...WILL SWITCH INTO THE NW AND N FROM
ABT MID-MRNG ONWARD AT KITH/KBGM/KRME. AT KAVP...THOUGH...SW WINDS WILL PERSIST
TIL THIS AFTN...BEFORE THE WIND SHIFT TAKES PLACE.
TONIGHT...-RA WILL EXIT THE RGN FROM NW TO SE...IN THE 00-04Z TIME
FRAME. EVEN AFTER THE RAIN ENDS...THOUGH...MVFR CIGS ARE VERY
LIKELY TO LINGER.
.OUTLOOK...
SUN...MAINLY VFR...AT LEAST FOR THE AM HRS.
SUN NGT-MON...RESTRICTIONS WILL BECOME MORE LIKELY AGAIN...AS
STEADIER PCPN PROBABLY RE-DEVELOPS (COULD BE -RA OR -SN).
TUE INTO WED...RESTRICTIONS STILL PSBL (LINGERING CLDS/LWR CIGS...AND
PERHAPS -SHRA/-SHSN).
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TAC
NEAR TERM...HEDEN/TAC
SHORT TERM...TAC
LONG TERM...MLJ/MSE
AVIATION...MLJ/SLI
AREA FORECAST DISCUSSION
NWS BUFFALO NY
205 AM EDT SAT APR 21 2012
.SYNOPSIS...
A COLD FRONT IS CROSSING THE REGION TONIGHT...BRINGING A PERIOD OF
SHOWERS...THEN COOLER TEMPERATURES FOR SATURDAY. HIGH PRESSURE ACROSS
EASTERN CANADA WILL BRING DRY BUT COOL CONDITIONS SUNDAY. THEN
STRENGTHENING LOW PRESSURE IN THE MID ATLANTIC WILL CIRCLE BACK
INTO NEW YORK MONDAY WHICH WILL RESULT IN A SOAKING RAIN AND
POSSIBLY SOME SNOW.
&&
.NEAR TERM /THROUGH TODAY/...
WEAK LOW PRESSURE SHIFTING EAST ACROSS LAKE ONTARIO WITH A COLD
FRONT NOW CROSSING WESTERN NEW YORK. THERE IS A CHANCE FOR A SHOWER
AHEAD OF AND ALONG THE FRONT BUT THE STEADIEST RAIN SHOULD ARRIVE
POST-FRONTAL AFTER MIDNIGHT INTO SATURDAY MORNING.
HAVE OBSERVED A FEW STRIKES OF LIGHTNING EARLIER THIS EVENING IN WEAKLY
CONVECTIVE CELLS ALONG THE LEADING EDGE OF THE FRONT. DUE TO
THIS...SLIGHT CHANCE FOR THUNDER REMAINS IN THE WEATHER GRIDS
THROUGH AROUND 05Z. THE REGIONAL RADAR MOSAIC SHOWS THE STEADIER
SHOWERS ARE BEHIND THE COLD FRONT MOVING ACROSS SOUTHERN ONTARIO AND
OHIO. THE POST FRONTAL SHOWERS ARE LIKELY THE RESULT OF LIFT ALOFT
GENERATED BY THE UPPER TROF OVER THE CENTRAL US.
THE 00Z HRRR MODEL SHOWS STEADY RAIN ARRIVING IN NIAGARA
FRONTIER/WESTERN SOUTHERN TIER AROUND 2AM...GENESEE VALLEY AROUND
4AM AND WATERTOWN SOUTH THROUGH CENTRAL NY AROUND 8AM. MOST AREAS
WILL SEE A FEW HOURS OF RAIN WITH AN AREA AVERAGE QPF OF .10 TO .25
INCHES.
LOWS WILL RANGE FROM THE 40S WEST...TO THE LOWER 50S EAST. A DECENT
SOUTHERLY FLOW EXISTS EAST AND SOUTHEAST OF LAKE ONTARIO THIS
EVENING...WITH HIGHER TERRAIN ON THE TUG HILL AND VALLEYS FAVORABLE
TO FUNNELING LIKELY TO SEE GUSTS OF 20 TO 30 MPH.
THE FRONT WILL SLOWLY EXIT TO THE EAST ON SATURDAY...WITH SHOWERS
EXPECTED TO GRADUALLY TAPER OFF. NOT TO OPTIMISTIC ABOUT A
CLEARING DURING THE DAY...GIVEN THE SLOW MOVEMENT OF THE
FRONT...HOWEVER FAR WESTERN PORTIONS MAY SEE A FEW BREAKS OF SUN
LATE SATURDAY AFTERNOON. CLOUDS WILL LIKELY KEEP TEMPERATURES IN THE
UPPER 40S TO LOWER 50S ACROSS WESTERN NEW YORK...NOTABLY COOLER THAN
THE PAST FEW DAYS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
HIGH PRESSURE BRIEFLY NOSES SOUTHWARD FROM EASTERN ONTARIO ON
SATURDAY NIGHT WITH SKIES CLEARING FROM WEST TO EAST. COOLER AND
DRIER AIR WITH THE CLEARING SKIES WILL ALLOW TEMPS TO FALL TO THE
LOWER 30S ACROSS THE SOUTHERN TIER AND TUG HILL REGION.
THE REGION WILL SEE A PARTLY TO MOSTLY SUNNY START TO SUNDAY WITH
CHILLY MORNING TEMPS RISING TO THE MID 40S TO AROUND 50 DEGREES BY
MID AFTERNOON. THERE WILL BE AN INCREASE IN CLOUDINESS AS A STRONG
STORM SYSTEM LIFTS NORTHWARD FROM THE MID ATLANTIC.
DEEPENING LOW PRESSURE MOVES UP THE MID ATLANTIC COAST AND
RETROGRESSES TO NEW YORK STATE ON MONDAY. THIS IS WELL DEPICTED BY
GFS AND ECMWF...THE EC IS JUST A LITTLE SLOWER THAN GFS...BUT THE
RESULT IS ABOUT THE SAME.
TO PUT THIS INTO SOME PERSPECTIVE...THIS PATTERN IS ALMOST A FRAME
BY FRAME REPLAY OF AN EVENT WHICH OCCURRED ON THE 2ND AND 3RD OF
APRIL 2005. THERE WAS AN 8 INCH SNOWFALL AT KBUF WITH MORE THAN A
FOOT OF SNOW ALONG THE CHAUTAUQUA RIDGE...AND EVEN TWO FEET OF SNOW
ACROSS NORTHWESTERN PA AND NORTHEAST OHIO.
THE CURRENT GFS AND ECMWF INDICATE THE POTENTIAL FOR SIMILAR AMOUNT
OF SNOW IN VERY SIMILAR LOCATIONS. GLANCING AT A COMPARISON OF THE
2005 EVENT AND CURRENT BUFKIT SOUNDINGS...THE VERTICAL TEMP/DEWPOINT
PROFILE IS NEARLY EXACT WITH THE CURRENT DATA SHOWING EVEN MORE
MOISTURE ALOFT. THE 2005 EVENT HAD PRECIPITABLE WATER RANGING FROM
.45 INCH TO .55 INCH...THE CURRENT DATA SHOW PWS AT OR ABOVE .75
INCH. ADDITIONALLY...THE 850MB TEMPS ARE COLDER BY A DEGREE OR TWO
SOUTH OF BUFFALO TO WESTERN PENNSYLVANIA.
SPEAKING OF MOISTURE...THERE WILL BE SIGNIFICANT MOISTURE WRAPPED
ABOUT THIS STORM...QPF FOR CENTRAL NY THROUGH MONDAY EVENING WILL BE
ON THE ORDER OF 2.5 INCHES WITH 1.75 TO 2.00 INCHES ACROSS WESTERN
NY. THE TRANSITION FROM RAIN TO SNOW WILL BE SOMEWHERE BETWEEN SYR
AND ROC SOUTHWARD ALONG SENECA AND CAYUGA LAKES. THE HEAVIEST SNOW
WILL LIKELY BE CENTERED ACROSS ALLEGANY/WYOMING/CATTARAUGUS COUNTIES
WITH SNOW TOTAL EXCEEDING A FOOT...ENHANCED BY NORTHEASTERLY TO
NORTHERN WINDS AND THE UPLIFT ALONG THE WESTERN SLOPE OF THE GENESEE
VALLEY.
EXPECT RAIN ALONG THE SOUTH SHORE OF LAKE ONTARIO AND ACROSS CENTRAL
TO NORTHERN NY. THE NEAR DROUGHT CONDITIONS OF LATE WILL ABSORB THE
RAINFALL AS LONG AS IT IS NOT TOO MUCH TOO FAST...THEN THERE MAY BE
A RISK OF LOW IMPACT AND SHORT LIVED FLOODING.
IN TERMS OF HOW POTENTIALLY UNUSUAL THIS WHOLE EVENT COULD BE (ESP
THE SNOW ASPECT OF IT)...NEARLY ALL OF THE MAJOR FORECAST PARAMETERS
(H5/7 HGHTS...MSLP...H85 TEMPS...U AND V WIND COMPONENTS) ARE 4 TO 5
STANDARD DEVIATIONS FROM NORMAL. IT IS CERTAINLY SIGNIFICANT WHEN A
COUPLE FORECAST PARAMETERS ARE THAT ANOMALOUS...BUT WHEN NEARLY ALL
OF THE MAIN FACTORS ARE THIS FAR FROM NORMAL...THEN THE EVENT STARTS
TO RISE TO THAT OF A MEMORABLE OR EVEN HISTORIC STATURE. THAT BEING
SAID...THESE PARAMETERS HAVE TO COME TOGETHER IN THE PERFECT MIX AND
THAT IS STILL FAR FROM A CERTAINTY.
TEMPS SUNDAY NIGHT WILL ONCE AGAIN BE QUITE CHILLY WITH CONTINUED
NORTHERLY WINDS...MID 30S ALONG THE LAKESHORES AND THE NORTH
COUNTRY...AND UPPER 20S TO AROUND 30 DEGREES FOR THE GENESEE VALLEY
AND WESTERN SOUTHERN TIER WHERE DYNAMIC COOLING FROM THE ONSET OF
SNOW WILL LOWER TEMPS EVEN FURTHER.
THICK CLOUD COVER AND PRECIP WILL HOLD TEMPS DOWN DURING MONDAY.
EXPECT THE WARMER TEMPS IN THE UPPER 40S TO LOWER 50S ACROSS THE
NORTH COUNTRY AND CENTRAL NY CLOSER TO THE CENTER OF THE LOW
PRESSURE. COLDER TEMPS ARE EXPECTED FOR THE WEST AND ESPECIALLY
SOUTHERN COUNTIES WITH LOWER 40S ALONG THE LAKESHORES AND THE 30S
FOR THE GENESEE VALLEY AND SOUTHERN TIER...IN THE REGION OF
CONTINUED LIKELIHOOD OF SNOWFALL.
THE POPS WILL FALL FROM WEST TO EAST ON MONDAY NIGHT AS THE LOW
PRESSURE CENTER LIFT NORTHWARD INTO QUEBEC PROVINCE...BUT WILL
REMAIN AS A CHANCE OF SNOW OR A MIX OF RAIN AND SNOW. LOWS WILL BE
IN THE UPPER 20S TO LOWER 30S ACROSS WESTERN AND SOUTHERN NY WITH
LOWER TO MID 30S ELSEWHERE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
GFS AND ECMWF REMAIN IN FAIR AGREEMENT FOR MUCH OF THE REST OF THE
WEEK. WILL KEEP LOW CHANCE POPS IN FOR TUESDAY AS THE REMAINS OF THE
PREVIOUS STORM MOVE AWAY FROM THE REGION...AND CHANCE POPS THROUGH
THURSDAY AFTERNOON AS THE UPPER TROUGH OVER EASTERN CANADA STREAMS A
SERIES OF VORTICITY MAXIMA ACROSS THE GREAT LAKES REGION AND INTO
NEW YORK STATE.
TEMPS WILL MODERATE THROUGH THE REST OF THE WEEK WITH HIGHS ON
TUESDAY IN THE UPPER 30S AND LOWER 40S CLIMBING TO HIGHS IN THE MID
50S TO NEAR 60 ON FRIDAY. OVERNIGHT LOWS WILL STILL SHOW LOCAL
FLIRTATIONS WITH THE FREEZING MARK FOR THE INTERIOR COUNTIES...WITH
MID TO UPPER 30S ELSEWHERE.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A COLD FRONT IS CURRENTLY IN THE PROCESS OF CROSSING THE FORECAST
AREA WITH THE FRONTAL BOUNDARY CLEARLY DEMARCATED ALONG A LINE
RUNNING FROM KART TO BETWEEN KBFD/KJHW. WINDS ARE QUICKLY VEERING
FROM SOUTHERLY JUST AHEAD OF THE FRONT TO NORTHWESTERLY BEHIND THE
BOUNDARY. A SLOW MOVING BAND OF SHOWERS BEHIND THE FRONT IS CROSSING
LAKE ERIE AND THE NIAGARA PENINSULA AND WILL BE MOVING INTO FAR
WESTERN NEW YORK WITHIN THE NEXT COUPLE OF HOURS. CIGS WILL DROP
INTO MVFR TERRITORY WITH IFR POSSIBLE PARTICULARLY AT KJHW WHERE
UPSLOPE FLOW WILL AID IN LOWERING CIGS.
THIS BAND OF SHOWERS WILL SLOWLY MOVE EAST THROUGH THE REST OF THE
NIGHT AND INTO SATURDAY MORNING...ARRIVING AT KART BY AROUND 12Z.
PRECIP WILL TAPER OFF ACROSS FAR WESTERN NEW YORK BY LATE
MORNING...THOUGH MVFR CIGS WILL LIKELY HANG AROUND UNTIL
APPROXIMATELY 00Z. THE IMPROVING CONDITIONS WILL GRADUALLY WORK
THEIR WAY EAST WHILE IMPROVING TO VFR SATURDAY NIGHT.
OUTLOOK...
SATURDAY NIGHT AND SUNDAY...MAINLY VFR.
SUNDAY NIGHT...LOWERING TO MVFR IN LIKELY SHOWERS.
MONDAY...IFR/MVFR. RAIN OR SNOW LIKELY.
TUESDAY THROUGH THURSDAY...VFR/MVFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
A COLD FRONT WILL SLOWLY CROSS THE EASTERN LAKES TONIGHT. A DECENT
SOUTHERLY FLOW AHEAD OF THE FRONT HAS ALLOWED A FEW GUSTS TO 20KTS
ON EASTERN PORTIONS OF LAKE ONTARIO THIS EVENING WHICH ARE MARGINAL
SUB-SMALL CRAFT CRITERIA. WINDS WILL NOT BE STRONG BEHIND THE FRONT.
THE FRONT WILL SHIFT EAST SATURDAY MORNING WITH NO ANTICIPATED
MARINE IMPACTS EXPECTED SATURDAY AND SUNDAY.
STRONG LOW PRESSURE WILL DEVELOP IN THE MID ATLANTIC REGION SUNDAY
NIGHT...WITH AN INCREASING NE-N FLOW ON THE WATERS. THIS WILL LIKELY
RESULT IN SOME FLAGS ON THE WATERS...WITH GALES A GOOD
POSSIBILITY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...SMITH
SHORT TERM...RSH/WCH
LONG TERM...WCH
AVIATION...WOOD
MARINE...SMITH
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
955 AM CDT SAT APR 21 2012
.DISCUSSION...FORECAST CHALLENGE CONCERNS PCPN
COVERAGE/LOCATION...WIND AND TEMPERATURES.
WELL DEFINED COMPACT MID LEVEL CIRCULATION DROPPING SE THROUGH FA AT
THIS TIME FROM WATER VAPOR IMAGERY. ASSOCIATED SURFACE LOW BETWEEN
DVL AND GFK TO PROPAGATE SE REACHING WEST CENTRAL/SW MN BY EVENING.
MAIN BAND OF SHRA EXTEND FROM WEST CENTRAL MN ARCING NW AROUND
SURFACE LOW ACROSS FAR NORTHERN FA. WILL ADJUST POPS ACCORDINGLY
LOWERING CHANCES ACROSS SE NE FOR AT LEAST THE MORNING. THIS
AFTERNOON AS THE LOW CONTINUES TO SLIDE SE RUC INDICATING AIRMASS
BECOMING SLIGHTLY UNSTABLE ACROSS FAR SOUTHERN FA ALONG SURFACE
BOUNDARY. FAVORED CAPE LOOKS TO BE JUST SOUTH OF FA AND NOT SURE HOW
THICK APPROACHING SC DECK WILL BE AT THIS POINT SO WILL LEAVE OUT T
MENTION HOWEVER NOT OUT OF THE QUESTION. GOOD DARKENING FROM WATER
VAPOR IMAGERY ACROSS SW FA IN SW FLANK OF PASSING WAVE. BEING IN
FAVORED WIND ZONE RELATIVE TO WAVE THIS AREA COULD SEE SOME STRONGER
NW WINDS BEHIND SURFACE BOUNDARY. MODEL SOUNDINGS INDICATING FAIRLY
DEEP MIXED LAYER WITH AROUND 30KTS TO MIX DOWN. WINDS SHOULD REMAIN
BLO ADVISORY CRITERIA BUT WILL STILL BE WINDY. FAR SE FA SEEING SOME
SOLAR THIS AM HOWEVER SC CLOUD DECK TO OVERSPREAD TO A DEGREE. THIS
AREA WILL SEE WARMEST TEMPERATURES WITH N/NE FA COOLEST BEING UNDER
CLOUDS LONGEST.
&&
.AVIATION...
MVFR/IFR SC DECK SPREADING SE ON BACK SIDE OF SURFACE LOW. AS LOW
CONTINUES TO PROPAGATE SE TODAY EXPECT THESE LOWER CIGS TO SPREAD
ACROSS MOST OF FA HOWEVER HOPEFULLY WILL INCREASE TO MAINLY MVFR
LEVELS THIS AFTERNOON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
VOELKER/ROGERS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
750 PM EDT SUN APR 22 2012
.SYNOPSIS...
LOW PRESSURE ALONG THE NORTH CAROLINA COAST WILL TRACK NORTH
ACROSS CENTRAL PA MONDAY AND ACROSS WESTERN NY TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SCATTERED LIGHT RAIN SHOWERS HAVE BEEN ONGOING ACROSS NE OHIO LATE
THIS AFTERNOON. INSTABILITY IS MARGINAL OVER LAKE ERIE FOR SHOWERS
AND VISIBLE SATELLITE SHOWS DRIER AIR PUSHING SOUTH OUT OF CANADA.
REGIONAL RADARS DO SHOW SHOWERS INCREASING NEAR BUFFALO WITH FLOW
OFF LAKE ONTARIO COMBINING WITH INCREASING THETA-E ADVECTION IN THE
5-10K FOOT LAYER. THE RUC13 SHOWS THIS LOW LEVEL MOISTURE IN THE
VICINITY OF LAKE ONTARIO PUSHING SW ACROSS LAKE ERIE BY
MIDNIGHT...AND EXPECT TO SEE AN EXPANSION IN SHOWERS AGAIN AT THAT
TIME. WILL ADD SOME LIGHT SHOWERS TO THE FORECAST FOR THIS
EVENING...ALTHOUGH GENERALLY THINKING THAT THESE WILL DECREASE IN
COVERAGE WITH THE LOSS OF DAYTIME HEATING THROUGH ABOUT 10 PM BEFORE
SHOWING AN UPTICK LATER ON TONIGHT. NO CHANGES TO THE SNOW/WIND
HEADLINES AT THIS TIME.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
MODELS CONTINUE TO DEEPEN AND MOVE CAROLINA LOW NORTH ACROSS
CENTRAL PENNSYLVANIA ON MONDAY. COULD START AS A BRIEF PERIOD OF
RAIN BUT ONCE IT TRANSITIONS TO SNOW WILL REMAIN SNOW UNTIL LATE
TUESDAY...AS LOW LEVEL THICKNESSES SUPPORT ALL SNOW ON MONDAY.
ONLY CAVEAT TO THAT IS THE ERIE LAKESHORE. WITH A 50 DEGREE LAKE
AND A N FLOW OFF THE LAKE IMMEDIATELY NEAR THE LAKESHORE COULD SEE
PREDOMINATELY RAIN. BUT BUFKIT SOUNDING FOR ERIE SHOWS A VERY
SHALLOW WARM LAYER...SO EVEN THERE EXPECT PREDOMINATELY SNOW. EVEN
THOUGH IT WILL TAKE A LITTLE LONGER THERE TO TRANSITION TO SNOW.
BUFKIT CONTINUES TO SHOW VERY DEEP LAYER OF SNOW GROWTH SO
SUBSTANTIAL AMOUNTS OF SNOW VERY REALISTIC. ONLY DOUBT IN MY MIND
IS HOW FAR WEST THE SNOW SHIELD WILL EXTEND. NAM CONTINUES TO BE
SLIGHTLY FURTHER TO THE WEST WITH THE LOW...AND THUS THE SNOW. HPC
LEANING TOWARD THE GFS TRACK SO TRENDED MY FORECAST TO THE GFS
SOLUTION. THE 850 TEMPS DIP TO MINUS 6C TOMORROW...SO NOT ONLY
WILL THERE BE SYNOPTIC BUT ALSO LAKE ENHANCED SNOW. WITH THE WET
HEAVY SNOW AND WINDS GUSTING TO NEAR 50 MPH TOMORROW AFTERNOON
POTENTIAL THREAT FOR TREES AND POWER LINES TOMORROW.
AM SKEPTICAL ABOUT HOW FAST CONDITIONS WILL WARM ON TUESDAY BUT
FOR NOW WILL CONTINUE WARMING TREND ON TUESDAY.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A STORM SYSTEM WILL MOVE ACROSS THE REGION ON THURSDAY AND WILL SEE
SOME SHOWERS ACROSS THE AREA. HAVE BUMPED PRECIP CHANCES UP A
LITTLE MOST AREAS. THURSDAY NIGHT THROUGH SATURDAY WILL BE DRY.
WILL START TO SEE AN INCREASE IN MOISTURE FROM THE W AND SW SATURDAY
NIGHT INTO SUNDAY. WILL PUT A SMALL MENTION OF PRECIP IN THE WEST
FOR SUNDAY BUT WILL KEEP THE EAST DRY. TEMPS DURING THE PERIOD WILL
AVERAGE BELOW NORMAL.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MVFR CEILINGS WILL LIKELY IMPROVE TO VFR MUCH OF THE NIGHT AS
SOME DRY AIR WRAPS ACROSS THE AREA. NORTH WINDS WILL BE GUSTY AT
TIMES.
THE STORM SYSTEM ALONG THE EAST COAST WILL PLOW NORTH ACROSS NEW
YORK STATE ON MONDAY AND THE PRECIPITATION SHIELD WILL SPREAD
WESTWARD ACROSS NORTHWEST PA AND PARTS OF NORTHEAST OH. IT WILL BE
COLD ENOUGH THAT AREAS THAT GET HEAVY PRECIPITATION WILL SEE MOSTLY
SNOW WITH IFR CONDITIONS (KERI AND KYNG). THERE WILL BE A SHARP
CUT OFF THOUGH AT THE WESTERN EDGE OF THE PRECIPITATION SO THERE
IS SOME UNCERTAINTY TO THE FORECAST AROUND KCLE AND KCAK ON HOW
MUCH PRECIPITATION WILL OCCUR. IF IT DOES GET TO KCLE AND KCAK IT
WILL PROBABLY BE SNOW FOR A WHILE WITH MVFR OR PERHAPS IFR CONDITIONS.
NW OHIO WILL STAY VFR ON MONDAY. ALL TAF SITES WILL HAVE STRONG
AND GUSTY NORTH TO NORTHWEST WINDS ON MONDAY.
.OUTLOOK...NON VFR EASTERN OH/NW PA MONDAY NIGHT INTO TUESDAY.
NON VFR LIKELY AGAIN THURSDAY INTO FRIDAY.
&&
.MARINE...
WILL GO WITH A GALE FOR ALL OF LAKE ERIE STARTING AT 10 PM THIS
EVENING. NORTHERLY FLOW WILL TAKE ON A NW COMPONENT MONDAY.
EXPECT WIND SPEEDS TO DIMINISH ON MONDAY NIGHT. WILL HOWEVER
LIKELY NEED SMALL CRAFT ADVISORIES FOR THE NEARSHORE THROUGH
TUESDAY. A RIDGE WILL CROSS THE LAKE ON WEDNESDAY CAUSING THE FLOW
TO RETURN TO THE SW. A FAST MOVING SYSTEM WILL MOVE ACROSS THE
REGION ON THURSDAY WITH THE FLOW BECOMING NW TO N. HIGH PRESSURE
WILL BUILD ACROSS THE AREA ON FRIDAY WITH THE FLOW BECOMING LIGHT
BY FRIDAY NIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 8 AM TO 8 PM EDT MONDAY FOR OHZ003-006>013-
018>022.
WINTER STORM WARNING FROM 4 AM MONDAY TO 3 PM EDT TUESDAY FOR
OHZ014-023-033-089.
PA...WINTER STORM WARNING FROM 4 AM MONDAY TO 3 PM EDT TUESDAY FOR
PAZ001>003.
MARINE...GALE WARNING UNTIL 10 PM EDT MONDAY FOR LEZ061-142>149-162>169.
&&
$$
SYNOPSIS...DJB
NEAR TERM...KEC
SHORT TERM...DJB
LONG TERM...KUBINA
AVIATION...KOSARIK
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
723 PM EDT SUN APR 22 2012
.SYNOPSIS...
LOW PRESSURE ALONG THE NORTH CAROLINA COAST WILL TRACK NORTH
ACROSS CENTRAL PA MONDAY AND ACROSS WESTERN NY TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SCATTERED LIGHT RAIN SHOWERS HAVE BEEN ONGOING ACROSS NE OHIO LATE
THIS AFTERNOON. INSTABILITY IS MARGINAL OVER LAKE ERIE FOR SHOWERS
AND VISIBLE SATELLITE SHOWS DRIER AIR PUSHING SOUTH OUT OF CANADA.
REGIONAL RADARS DO SHOW SHOWERS INCREASING NEAR BUFFALO WITH FLOW
OFF LAKE ONTARIO COMBINING WITH INCREASING THETA-E ADVECTION IN THE
5-10K FOOT LAYER. THE RUC13 SHOWS THIS LOW LEVEL MOISTURE IN THE
VICINITY OF LAKE ONTARIO PUSHING SW ACROSS LAKE ERIE BY
MIDNIGHT...AND EXPECT TO SEE AN EXPANSION IN SHOWERS AGAIN AT THAT
TIME. WILL ADD SOME LIGHT SHOWERS TO THE FORECAST FOR THIS
EVENING...ALTHOUGH GENERALLY THINKING THAT THESE WILL DECREASE IN
COVERAGE WITH THE LOSS OF DAYTIME HEATING THROUGH ABOUT 10 PM BEFORE
SHOWING AN UPTICK LATER ON TONIGHT. NO CHANGES TO THE SNOW/WIND
HEADLINES AT THIS TIME.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
MODELS CONTINUE TO DEEPEN AND MOVE CAROLINA LOW NORTH ACROSS
CENTRAL PENNSYLVANIA ON MONDAY. COULD START AS A BRIEF PERIOD OF
RAIN BUT ONCE IT TRANSITIONS TO SNOW WILL REMAIN SNOW UNTIL LATE
TUESDAY...AS LOW LEVEL THICKNESSES SUPPORT ALL SNOW ON MONDAY.
ONLY CAVEAT TO THAT IS THE ERIE LAKESHORE. WITH A 50 DEGREE LAKE
AND A N FLOW OFF THE LAKE IMMEDIATELY NEAR THE LAKESHORE COULD SEE
PREDOMINATELY RAIN. BUT BUFKIT SOUNDING FOR ERIE SHOWS A VERY
SHALLOW WARM LAYER...SO EVEN THERE EXPECT PREDOMINATELY SNOW. EVEN
THOUGH IT WILL TAKE A LITTLE LONGER THERE TO TRANSITION TO SNOW.
BUFKIT CONTINUES TO SHOW VERY DEEP LAYER OF SNOW GROWTH SO
SUBSTANTIAL AMOUNTS OF SNOW VERY REALISTIC. ONLY DOUBT IN MY MIND
IS HOW FAR WEST THE SNOW SHIELD WILL EXTEND. NAM CONTINUES TO BE
SLIGHTLY FURTHER TO THE WEST WITH THE LOW...AND THUS THE SNOW. HPC
LEANING TOWARD THE GFS TRACK SO TRENDED MY FORECAST TO THE GFS
SOLUTION. THE 850 TEMPS DIP TO MINUS 6C TOMORROW...SO NOT ONLY
WILL THERE BE SYNOPTIC BUT ALSO LAKE ENHANCED SNOW. WITH THE WET
HEAVY SNOW AND WINDS GUSTING TO NEAR 50 MPH TOMORROW AFTERNOON
POTENTIAL THREAT FOR TREES AND POWER LINES TOMORROW.
AM SKEPTICAL ABOUT HOW FAST CONDITIONS WILL WARM ON TUESDAY BUT
FOR NOW WILL CONTINUE WARMING TREND ON TUESDAY.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A STORM SYSTEM WILL MOVE ACROSS THE REGION ON THURSDAY AND WILL SEE
SOME SHOWERS ACROSS THE AREA. HAVE BUMPED PRECIP CHANCES UP A
LITTLE MOST AREAS. THURSDAY NIGHT THROUGH SATURDAY WILL BE DRY.
WILL START TO SEE AN INCREASE IN MOISTURE FROM THE W AND SW SATURDAY
NIGHT INTO SUNDAY. WILL PUT A SMALL MENTION OF PRECIP IN THE WEST
FOR SUNDAY BUT WILL KEEP THE EAST DRY. TEMPS DURING THE PERIOD WILL
AVERAGE BELOW NORMAL.
&&
.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
THE CALM BEFORE THE STORM. MUCH OF THE AREA IS VFR THIS AFTERNOON00N
BUT SOME PATCHES OF MVFR AND SPRINKLES CONTINUE IN THE EAST. CIGS
SHOULD LIFT TO VFR ALL AREAS BY LATE AFTERNOON. VFR WEATHER IS
MAINLY EXPECTED TONIGHT. DO EXPECT CIGS TO BEGIN TO LOWER IN THE
EAST AFTER MIDNIGHT. NEW MODELS CONTINUE TO SUGGEST PRECIP
REACHING KYNG AND KERI AROUND DAYBREAK. TEMP PROFILE SUGGESTS A
MIX OF RAIN AND SNOW OR ALL SNOW. KERI MAY ACTUALLY SEE MORE RAIN
THAN SNOW GIVEN FLOW OFF OF 50 DEGREE LAKE ERIE. EXPECT PRECIP TO
REACH KCAK DURING THE MORNING HOURS. RIGHT NOW THINK THE PRECIP
WILL BE JUST EAST OF KMFD AND KCLE AT 18Z MONDAY. CIGS WILL DIP TO
MVFR SHORTLY AFTER THE PRECIP ENDS AND EXPECT IFR CONDITIONS BY
THE END OF THE PERIOD AT KYNG. WINDS WILL BE THE OTHER STORY WITH
NE TO N FLOW TONIGHT. LATE TONIGHT THE WINDS WILL BECOME MORE NW
AND COULD SEE GUSTS TO 35 KNOTS BY MIDDAY MONDAY.
.OUTLOOK...NON VFR EASTERN OH/NW PA MONDAY AFTERNOON THROUGH
TUESDAY WITH ACCUMULATING SNOW. SOME NON VFR POSSIBLE LATE
WEDNESDAY INTO THURSDAY AREA-WIDE.
&&
.MARINE...
WILL GO WITH A GALE FOR ALL OF LAKE ERIE STARTING AT 10 PM THIS EVENING.
NORTHERLY FLOW WILL TAKE ON A NW COMPONENT LATE TONIGHT AND
MONDAY. EXPECT WIND SPEEDS TO DIMINISH ON MONDAY NIGHT. WILL
HOWEVER LIKELY NEED SMALL CRAFT ADVISORIES FOR THE NEARSHORE
THROUGH TUESDAY. A RIDGE WILL CROSS THE LAKE ON WEDNESDAY CAUSING
THE FLOW TO RETURN TO THE SW. A FAST MOVING SYSTEM WILL MOVE
ACROSS THE REGION ON THURSDAY WITH THE FLOW BECOMING NW TO N. HIGH
PRESSURE WILL RETURN FOR FRIDAY WITH THE FLOW TAKING ON AN
EASTERLY COMPONENT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY FROM 8 AM TO 8 PM EDT MONDAY FOR OHZ003-006>013-
018>022.
WINTER STORM WARNING FROM 4 AM MONDAY TO 3 PM EDT TUESDAY FOR
OHZ014-023-033-089.
PA...WINTER STORM WARNING FROM 4 AM MONDAY TO 3 PM EDT TUESDAY FOR
PAZ001>003.
MARINE...GALE WARNING UNTIL 10 PM EDT MONDAY FOR LEZ061-142>149-162>169.
&&
$$
SYNOPSIS...DJB
NEAR TERM...KEC
SHORT TERM...DJB
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1128 PM EDT SUN APR 22 2012
.SYNOPSIS...
LOW PRESSURE CENTERED JUST EAST OF NORFOLK VIRGINIA THIS EVENING
GRADUALLY INTENSIFY AS IT PUSHES TO THE NORTH THEN NORTHWEST
OVERNIGHT AND MONDAY...REACHING THE FINGER LAKES REGION OF NEW
YORK STATE LATE MONDAY. COLDER AIR BEING PULLED SOUTH INTO
WESTERN AND CENTRAL PENNSYLVANIA WILL CHANGE THE RAIN OVER TO
HEAVY WET SNOW ACROSS THE NORTHWEST HALF OF THE STATE DURING THE
OVERNIGHT HOURS. THE HEAVIEST SNOW IS EXPECTED ON THE HIGHER
ELEVATIONS OF NORTH CENTRAL AND NORTHWESTERN PENNSYLVANIA...AND
THE LAUREL HIGHLANDS. HEAVY WET ACCUMULATIONS OF SNOW WILL PRODUCE
WIDESPREAD TREE DAMAGE AND LEAD TO POWER OUTAGES. IMPROVING...BUT
STILL UNSETTLED CONDITIONS WILL FOLLOW FOR TUESDAY AND WEDNESDAY
AS THE COLDEST AIR RETREATS NORTHWARD AND A FAST WESTERLY FLOW
ALOFT DEVELOPS.
&&
.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
AN EXTENSIVE SHIELD OF RAIN /SOME HEAVY/ WAS PIVOTING TO THE
NORTHWEST AHEAD OF A POTENT SHORTWAVE PUSHING NORTH ALONG THE
I-95 CORRIDOR.
DUAL POL CORRELATION COEFFICIENT PRODUCT NICELY INDICATES THAT THE
PRECIP HAS CHANGED OVER TO WET SNOW AT THE BEAM HEIGHT OF
2500-3000 MSL JUST TO THE EAST OF THE RDA...WHILE THIS CC PRODUCT
AND SFC OBS INDICATES THAT THE CHANGEOVER HAS REACHED THE GROUND
ACROSS THE NW MTNS. KDUJ AND KBFD CHANGED TO SNOW BETWEEN 00Z AND
01Z...WHILE KFIG AND KJST JUST WENT OVER TO ALL SNOW WITHIN THE PAST
30 MINUTES. SOME WET SNOW FLAKES HAVE BECOME MIXED IN AROUND THE
HAPPY VALLEY AREA...AND A CHANGOVER TO HEAVY WET SNOW SHOULD OCCUR
FROM KAOO TO KUNV BETWEEN 03Z-05Z BASED ON THE 01Z RUC FCST OF MEAN
925-850 MB WET BULB TEMPS DIPPING SLIGHTLY TO JUST -0.5 TO -1C.
MIXED PHASE PRECIP IS NOTED AT ELEVATIONS AS LOW AS 4500 FT MSL TO
THE EAST THROUGH SSE /AT FURTHER DISTANCES AWAY FROM THE RADAR
SITE/...HIGHLIGHTING THE STRONG EAST TO WEST MID LEVEL TEMP GRADIENT
FROM THE CENTRAL MTNS TO THE SUSQ VALLEY.
THE SLOWLY DEEPENING AND DIGGING UPPER LOW HEADED OUT OF THE MID
OHIO RIVER VALLEY IS BEGINNING TO CAPTURE DEEP MOISTURE FROM THIS
LEAD SHORT WAVE...AS THE FLOW ALOFT CONTINUES TO BACK THROUGH THE
SOUTH AND BECOMES SERLY.
THE BACK /SWRN EDGE/ EDGE OF THIS CURRENT PRECIP SHIELD WILL
LIKELY EXPAND TO THE SW...AND PIVOT SLOWLY WWD ACROSS THE
COMMONWEALTH OVERNIGHT AND TUESDAY MORNING WITH PRECIP RATES BEING
MAINTAINED OR EVEN INCREASING ACROSS THE CENTRAL MTNS AND
ALLEGHENY PLATEAU...LEADING TO HEAVY WET SNOW WITHIN A FEW
QUASI-SNTRY BANDS OF MDT TO STG FRONTOGENESIS.
NO APPRECIABLE CHANGE WAS MADE TO THE GRIDDED FCST DATABASE WITH
RESPECT TO THE TIMING OF THE RAIN TO SNOW CHANGEOVER...AND
RESULTANT SNOW ACCUMS BY 12Z MONDAY. WILL BE KEEPING A WATCHFUL
EYE THOUGH ON THE HIGH TERRAIN OF SULLIVAN COUNTY /NE OF
KIPT/...SINCE THEY/RE CURRENTLY ONLY IN THE MID 30S WITH WEAK LLVL
COLD ADVECTION CONTINUING. HOWEVER...WARMER AIR SURGING IN ALOFT
FROM THE SSE SHOULD LIMIT ANY CHANGEOVER FOR MUCH OF THE NIGHT TO
JUST A MIX OF WET SNOW AND SLEET AT BEST.
THE RAINFALL IN THE EAST HAS BEEN A STEADY/MODERATELY HEAVY COLD
RAIN FALLING AT A RATE OF GENERALLY 102 TENTHS OF AN INCH PER
HOUR. THE VERY DRY ANTECEDENT CONDITIONS AND EARLY GREEN-UP WILL
ABLE TO EASILY HANDLE THIS RATE...AND TOTAL FCST RAINFALL OF 1-2
INCHES...WITH MINOR TO AT MOST MODERATE RISES ON SMALLER STREAMS
OVER...AND TO THE EAST OF THE SUSQ MAINSTEM.
THE RAIN WILL BE TAPERING OFF IN THE EAST BETWEEN 05Z AND 09Z
MONDAY.
LOW TEMPS OVERNIGHT WILL RANGE FROM THE LOWER 40S IN THE SE
ZONES...TO AROUND 30 ACROSS THE HIGHEST TERRAIN OF THE WEST.
&&
.SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
PERIODS OF MDT TO HEAVY WET SNOW WILL PERSIST ACROSS THE NW MTNS
AND LAUREL HIGHLANDS FOR MUCH OF MONDAY AS THE UPPER LOW TURNS NE
AND LIFTS ACROSS CENTRAL PENN. A MIX OF WET SNOW...AND RAIN IS
STILL EXPECTED IN THE LOWER ELEVS OF THE RIDGE AND VALLEY REGION.
THE SFC/BLYR TEMPS ARE THE TRICK TO THIS FCST - WITH THE SNOW
ACCUMS ALMOST ENTIRELY ELEV /AND SNOWFALL RATE/ DEPENDENT. THE
TIMES OF HEAVY SNOW WILL BE TOUGH TO PINPOINT...AND WILL KEEP IT
BROAD BRUSHED. WILL MAINTAIN THE GOING FCST AS THERE IS NO REASON
TO CHANGE. TEMPS WILL HOVER IN THE LOWER AND MID 30S IN THE
CENTRAL MTS...BUT 30-33 IN THE WRN AND NRN HIGHLANDS. THE ODDITY
OF THIS FCST WILL BE THE RELATIVELY WARM AND DRY AIR THAT GETS
INTO SULLIVAN AND TIOGA COS. ONLY MINOR TWEAKS TO THE SNOW ACCUMS
ARE EXPECTED.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
DEEP TROUGH AND POWERFUL UPPER LOW WILL BE CENTERED OVER THE PA/NY
BORDER MON NIGHT...WITH 500 MB HEIGHTS BELOW 530 FORECAST SOLIDLY BY
THE ECMWF GFS AND NAM. LOW GRADUALLY LIFTS STRAIGHT NORTHWARD AS IT
DEEPENS A BIT FURTHER THROUGH 12Z TUE...THEN BEGINS TO FILL IN ON
TUE UPON ARRIVING IN S CANADA. 987MB SFC LOW ALSO PUSHING NORTHWARD
INTO S NY STATE MON NIGHT WILL FOCUS PRECIP ON ITS COLD SIDE AS 50+
KT COLD CONVEYOR BELT WRAPS AROUND FROM THE NW...WITH LITTLE PRECIP
INDICATED FOR EASTERN HALF OF CWA. SO...ONGOING WINTER WEATHER EVENT
ACROSS WESTERN HALF OF CWA WILL CONTINUE TO BE INTENSE HEADING INTO
MON NIGHT...AND GRADUALLY LESSEN ITS GRIP AS NIGHT PROGRESSES AS
COLD CONVEYOR BELT LIFTS NORTHWARD...RESULTING IN JUST A LIGHTER
SNOW BY 12Z TUE - WHICH WILL LINGER IN THE NORTHERN MTNS POSS INTO
WED.
THE WINTER STORM WARNING/ADVISORY DURATION THROUGH MON NIGHT LOOKS
JUSTIFIED BASED ON QPF FORECASTS/IMPACTS. STORM TOTAL SNOWFALL
OVER MUCH OF THE ALLEGHENIES SHOULD EASILY EXCEED 8 INCHES...WITH
SOME 12-16 INCH AMOUNTS PAINTED IN. SNOWFALL TAPERS OFF FAIRLY
SHARPLY HEADING EAST ACROSS C MTNS...WITH A STRIPE OF 2 TO 5
INCHES IN THE CENTRAL MOUNTAINS - ACCUMULATING MAINLY ON THE
GRASSY SURFACES WITH A LESSER IMPACT ON ROADS. LITTLE ACCUM
EXPECTED IN SUSQ VALLEY...THOUGH SOME SNOW COULD MIX IN ON
OCCASION WITH THE PREDOMINANT PRECIP TYPE OF RAIN - EVEN AS IT
TAPERS TO SHOWERS MON NIGHT INTO TUES.
THE DEEP UPPER TROF LIFTS TO THE NE WED-WED NIGHT...BUT NORTHWEST
FLOW PERSISTS AS ADDITIONAL WEAKER DISTURBANCES ROTATE ACROSS THE
REGION THROUGH THE REMAINDER OF THE WEEK...KEEPING WEATHER SOMEWHAT
UNSETTLED INTO FRI BEFORE A DRIER REGIME MOVES IN. TEMPS LOOK TO BE
BELOW NORMAL FOR MUCH OF THE WEEK.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
STRENGTHENING LOW PRES PASSING JUST EAST OF PA OVERNIGHT WILL
BRING SNOW WITH LOW CIGS/VSBYS AND GUSTY NW WINDS ACROSS THE W
MTNS OVERNIGHT AND MONDAY. AOO AND UNV ARE ALSO LIKELY TO BECOME
IFR AS RAIN CHANGES TO ALL SNOW AFTER MIDNIGHT. A DRY SLOT IS
EXPECTED TO WORK INTO EASTERN PA BTWN 05Z-08Z...CAUSING THE RAIN
TO TAPER OFF OVR THE SUSQ VALLEY. HOWEVER...MVFR CIGS AND SCT
-SHRA SHOULD PERSIST THRU THE NIGHT AT IPT/MDT/LNS.
AS THE STORM SYSTEM PASSES JUST TO OUR EAST...EXPECT GUSTY NW
WINDS TO BUFFET THE AREA ON MONDAY...ESP OVR THE LAUREL HIGHLANDS
WHERE BUFKIT SOUNDINGS SUPPORT GUSTS TO NR 30KTS AT JST. THE
COLD...MOIST...UPSLOPING FLOW WILL PRODUCE SNOW AND LOW VSBYS/CIGS
AT BFD/JST. SOMEWHAT BETTER CONDS LIKELY AT AOO/UNV...BUT OCNL
SNOW COULD PRODUCE IFR VSBYS AT TIMES. MOST FAVORABLE CONDS WILL
BE ACROSS THE SUSQ VALLEY...WHERE DRYING...DOWNSLOPING FLOW RESULT
IN ONLY SCT -SHRA AND MVFR CIGS.
OUTLOOK...
TUE...LOW CIGS/VSBYS POSS AT BFD IN OCNL SHSN.
WED...NO SIG WX EXPECTED.
THU...RAIN/LOW CIGS POSS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON EDT TUESDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041.
WINTER WEATHER ADVISORY UNTIL 6 AM EDT TUESDAY FOR PAZ019-025-
026-034-035-045.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION...CORRECTED NEAR TERM SECTION
NWS STATE COLLEGE PA
1019 PM EDT SUN APR 22 2012
.SYNOPSIS...
LOW PRESSURE CENTERED JUST EAST OF NORFOLK VIRGINIA THIS EVENING
GRADUALLY INTENSIFY AS IT PUSHES TO THE NORTH THEN NORTHWEST
OVERNIGHT AND MONDAY...REACHING THE FINGER LAKES REGION OF NEW
YORK STATE LATE MONDAY. COLDER AIR BEING PULLED SOUTH INTO
WESTERN AND CENTRAL PENNSYLVANIA WILL CHANGE THE RAIN OVER TO
HEAVY WET SNOW ACROSS THE NORTHWEST HALF OF THE STATE DURING THE
OVERNIGHT HOURS. THE HEAVIEST SNOW IS EXPECTED ON THE HIGHER
ELEVATIONS OF NORTH CENTRAL AND NORTHWESTERN PENNSYLVANIA...AND
THE LAUREL HIGHLANDS. HEAVY WET ACCUMULATIONS OF SNOW WILL PRODUCE
WIDESPREAD TREE DAMAGE AND LEAD TO POWER OUTAGES. IMPROVING...BUT
STILL UNSETTLED CONDITIONS WILL FOLLOW FOR TUESDAY AND WEDNESDAY
AS THE COLDEST AIR RETREATS NORTHWARD AND A FAST WESTERLY FLOW
ALOFT DEVELOPS.
&&
.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
AN EXTENSIVE SHIELD OF RAIN /SOME HEAVY/ WAS PIVOTING TO THE
NORTHWEST AHEAD OF A POTENT SHORTWAVE PUSHING NORTH ALONG THE
I-95 CORRIDOR.
DUAL POL CORRELATION COEFFICIENT PRODUCT NICELY INDICATES THAT THE
PRECIP HAS CHANGED OVER TO WET SNOW AT THE BEAM HEIGHT OF
2500-3000 MSL JUST TO THE EAST OF THE RDA...WHILE THIS CC PRODUCT
AND SFC OBS INDICATES THAT THE CHANGEOVER HAS REACHED THE GROUND
ACROSS THE NW MTNS. KDUJ AND KBFD CHANGED TO SNOW BETWEEN 00Z AND
01Z...WHILE KFIG AND KJST JUST WENT OVER TO ALL SNOW WITHIN THE PAST
30 MINUTES. SOME WET SNOW FLAKES HAVE BECOME MIXED IN AROUND THE
HAPPY VALLEY AREA...AND A CHANGOVER TO HEAVY WET SNOW SHOULD OCCUR
FROM KAOO TO KUNV BETWEEN 03Z-05Z BASED ON THE 01Z RUC FCST OF MEAN
925-850 MB WET BULB TEMPS DIPPING SLIGHTLY TO JUST -0.5 TO -1C.
MIXED PHASE PRECIP IS NOTED AT ELEVATIONS AS LOW AS 4500 FT MSL TO
THE EAST THROUGH SSE /AT FURTHER DISTANCES AWAY FROM THE RADAR
SITE/...HIGHLIGHTING THE STRONG EAST TO WEST MID LEVEL TEMP GRADIENT
FROM THE CENTRAL MTNS TO THE SUSQ VALLEY.
THE SLOWLY DEEPENING AND DIGGING UPPER LOW HEADED OUT OF THE MID
OHIO RIVER VALLEY IS BEGINNING TO CAPTURE DEEP MOISTURE FROM THIS
LEAD SHORT WAVE...AS THE FLOW ALOFT CONTINUES TO BACK THROUGH THE
SOUTH AND BECOMES SERLY.
THE BACK /SWRN EDGE/ EDGE OF THIS CURRENT PRECIP SHIELD WILL
LIKELY EXPAND TO THE SW...AND PIVOT SLOWLY WWD ACROSS THE
COMMONWEALTH OVERNIGHT AND TUESDAY MORNING WITH PRECIP RATES BEING
MAINTAINED OR EVEN INCREASING ACROSS THE CENTRAL MTNS AND
ALLEGHENY PLATEAU...LEADING TO HEAVY WET SNOW WITHIN A FEW
QUASI-SNTRY BANDS OF MDT TO STG FRONTOGENESIS.
NO APPRECIABLE CHANGE WAS MADE TO THE GRIDDED FCST DATABASE WITH
RESPECT TO THE TIMING OF THE RAIN TO SNOW CHANGEOVER...AND
RESULTANT SNOW ACCUMS BY 12Z MONDAY. WILL BE KEEPING A WATCHFUL
EYE THOUGH ON THE HIGH TERRAIN OF SULLIVAN COUNTY /NE OF
KIPT/...SINCE THEY/RE CURRENTLY ONLY IN THE MID 30S WITH WEAK LLVL
COLD ADVECTION CONTINUING. HOWEVER...WARMER AIR SURGING IN ALOFT
FROM THE SSE SHOULD LIMIT ANY CHANGEOVER FOR MUCH OF THE NIGHT TO
JUST A MIX OF WET SNOW AND SLEET AT BEST.
THE RAINFALL IN THE EAST HAS BEEN A STEADY/MODERATELY HEAVY COLD
RAIN FALLING AT A RATE OF GENERALLY 102 TENTHS OF AN INCH PER
HOUR. THE VERY DRY ANTECEDENT CONDITIONS AND EARLY GREEN-UP WILL
ABLE TO EASILY HANDLE THIS RATE...AND TOTAL FCST RAINFALL OF 1-2
INCHES...WITH MINOR TO AT MOST MODERATE RISES ON SMALLER STREAMS
OVER...AND TO THE EAST OF THE SUSQ MAINSTEM.
THE RAIN WILL BE TAPERING OFF IN THE EAST BETWEEN 05Z AND 09Z
MONDAY.
LOW TEMPS OVERNIGHT WILL RANGE FROM THE LOWER 40S IN THE SE
ZONES...TO AROUND 30 ACROSS THE HIGHEST TERRAIN OF THE WEST.
&&
.SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
PERIODS OF MDT TO HEAVY WET SNOW WILL PERSIST ACROSS THE NW MTNS
AND LAUREL HIGHLANDS FOR MUCH OF MONDAY AS THE UPPER LOW TURNS NE
AND LIFTS ACROSS CENTRAL PENN. A MIX OF WET SNOW...AND RAIN IS
STILL EXPECTED IN THE LOWER ELEVS OF THE RIDGE AND VALLEY REGION.
THE SFC/BLYR TEMPS ARE THE TRICK TO THIS FCST - WITH THE SNOW
ACCUMS ALMOST ENTIRELY ELEV /AND SNOWFALL RATE/ DEPENDENT. THE
TIMES OF HEAVY SNOW WILL BE TOUGH TO PINPOINT...AND WILL KEEP IT
BROAD BRUSHED. WILL MAINTAIN THE GOING FCST AS THERE IS NO REASON
TO CHANGE. TEMPS WILL HOVER IN THE LOWER AND MID 30S IN THE
CENTRAL MTS...BUT 30-33 IN THE WRN AND NRN HIGHLANDS. THE ODDITY
OF THIS FCST WILL BE THE RELATIVELY WARM AND DRY AIR THAT GETS
INTO SULLIVAN AND TIOGA COS. ONLY MINOR TWEAKS TO THE SNOW ACCUMS
ARE EXPECTED.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
DEEP TROUGH AND POWERFUL UPPER LOW WILL BE CENTERED OVER THE PA/NY
BORDER MON NIGHT...WITH 500 MB HEIGHTS BELOW 530 FORECAST SOLIDLY BY
THE ECMWF GFS AND NAM. LOW GRADUALLY LIFTS STRAIGHT NORTHWARD AS IT
DEEPENS A BIT FURTHER THROUGH 12Z TUE...THEN BEGINS TO FILL IN ON
TUE UPON ARRIVING IN S CANADA. 987MB SFC LOW ALSO PUSHING NORTHWARD
INTO S NY STATE MON NIGHT WILL FOCUS PRECIP ON ITS COLD SIDE AS 50+
KT COLD CONVEYOR BELT WRAPS AROUND FROM THE NW...WITH LITTLE PRECIP
INDICATED FOR EASTERN HALF OF CWA. SO...ONGOING WINTER WEATHER EVENT
ACROSS WESTERN HALF OF CWA WILL CONTINUE TO BE INTENSE HEADING INTO
MON NIGHT...AND GRADUALLY LESSEN ITS GRIP AS NIGHT PROGRESSES AS
COLD CONVEYOR BELT LIFTS NORTHWARD...RESULTING IN JUST A LIGHTER
SNOW BY 12Z TUE - WHICH WILL LINGER IN THE NORTHERN MTNS POSS INTO
WED.
THE WINTER STORM WARNING/ADVISORY DURATION THROUGH MON NIGHT LOOKS
JUSTIFIED BASED ON QPF FORECASTS/IMPACTS. STORM TOTAL SNOWFALL
OVER MUCH OF THE ALLEGHENIES SHOULD EASILY EXCEED 8 INCHES...WITH
SOME 12-16 INCH AMOUNTS PAINTED IN. SNOWFALL TAPERS OFF FAIRLY
SHARPLY HEADING EAST ACROSS C MTNS...WITH A STRIPE OF 2 TO 5
INCHES IN THE CENTRAL MOUNTAINS - ACCUMULATING MAINLY ON THE
GRASSY SURFACES WITH A LESSER IMPACT ON ROADS. LITTLE ACCUM
EXPECTED IN SUSQ VALLEY...THOUGH SOME SNOW COULD MIX IN ON
OCCASION WITH THE PREDOMINANT PRECIP TYPE OF RAIN - EVEN AS IT
TAPERS TO SHOWERS MON NIGHT INTO TUES.
THE DEEP UPPER TROF LIFTS TO THE NE WED-WED NIGHT...BUT NORTHWEST
FLOW PERSISTS AS ADDITIONAL WEAKER DISTURBANCES ROTATE ACROSS THE
REGION THROUGH THE REMAINDER OF THE WEEK...KEEPING WEATHER SOMEWHAT
UNSETTLED INTO FRI BEFORE A DRIER REGIME MOVES IN. TEMPS LOOK TO BE
BELOW NORMAL FOR MUCH OF THE WEEK.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
STRENGTHENING LOW PRES MOVING UP THE E COAST WILL SPREAD RAIN AND
INCREASINGLY GUSTY NNW WINDS ACROSS CENTRAL PA THIS EVENING. OVR
THE HIGHER TERRAIN OF WESTERN PA...THE RAIN WILL CHANGE TO SNOW
LATER THIS EVENING...ADDING LOW VSBYS TO THE ALREADY POOR FLYING
CONDS.
AT 00Z...BFD AND JST WERE THE ONLY CENTRAL PA AIRFIELDS REPORTING
IFR CIGS. HOWEVER...DETERIORATING CIGS EXPECTED OVERNIGHT ACROSS
THE CENTRAL MTNS...AS HEAVIER PRECIP OVERSPREADS THE AREA WITH IFR
CIGS LIKELY AT BOTH UNV AND AOO. AFTER 06Z...EXPECT A DRY SLOT TO
WORK INTO EASTERN PA...CAUSING THE RAIN TO TAPER OFF AT MDT AND
LNS. HOWEVER...SNOW WILL CONTINUE TO FALL AT BFD/JST WITH LIFR
VSBYS/CIGS QUITE POSSIBLE. ACROSS THE RIDGE/VALLEY REGION...AOO
AND UNV WILL LIKELY BE ON THE DIVIDING LINE BTWN RAIN/SNOW LATE
TONIGHT...BUT EITHER WAY...IFR CONDS APPEAR VERY LIKELY DUE TO LOW
CIGS.
AS THE STORM SYSTEM PASSES JUST TO OUR EAST...EXPECT GUSTY NW
WINDS TO BUFFET THE AREA ON MONDAY...ESP OVR THE LAUREL HIGHLANDS
WHERE BUFKIT SOUNDINGS SUPPORT GUSTS TO NR 30KTS AT JST. THE
COLD...MOIST...UPSLOPING FLOW WILL PRODUCE SNOW AND LOW VSBYS/CIGS
AT BFD/JST. SOMEWHAT BETTER CONDS LIKELY AT AOO/UNV...BUT OCNL
SNOW COULD PRODUCE IFR VSBYS AT TIMES. MOST FAVORABLE CONDS WILL
BE ACROSS THE SUSQ VALLEY...WHERE DRYING...DOWNSLOPING FLOW RESULT
IN ONLY SCT -SHRA AND MVFR CIGS.
OUTLOOK...
TUE...LOW CIGS/VSBYS POSS AT BFD IN OCNL SHSN.
WED...NO SIG WX EXPECTED.
THU...RAIN/LOW CIGS POSS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON EDT TUESDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041.
WINTER WEATHER ADVISORY UNTIL 6 AM EDT TUESDAY FOR PAZ019-025-
026-034-035-045.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1013 PM EDT SUN APR 22 2012
.SYNOPSIS...
LOW PRESSURE CENTERED JUST EAST OF NORFOLK VIRGINIA THIS EVENING
GRADUALLY INTENSIFY AS IT PUSHES TO THE NORTH THEN NORTHWEST
OVERNIGHT AND MONDAY...REACHING THE FINGER LAKES REGION OF NEW
YORK STATE LATE MONDAY. COLDER AIR BEING PULLED SOUTH INTO
WESTERN AND CENTRAL PENNSYLVANIA WILL CHANGE THE RAIN OVER TO
HEAVY WET SNOW ACROSS THE NORTHWEST HALF OF THE STATE DURING THE
OVERNIGHT HOURS. THE HEAVIEST SNOW IS EXPECTED ON THE HIGHER
ELEVATIONS OF NORTH CENTRAL AND NORTHWESTERN PENNSYLVANIA...AND
THE LAUREL HIGHLANDS. HEAVY WET ACCUMULATIONS OF SNOW WILL PRODUCE
WIDESPREAD TREE DAMAGE AND LEAD TO POWER OUTAGES. IMPROVING...BUT
STILL UNSETTLED CONDITIONS WILL FOLLOW FOR TUESDAY AND WEDNESDAY
AS THE COLDEST AIR RETREATS NORTHWARD AND A FAST WESTERLY FLOW
ALOFT DEVELOPS.
&&
.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
AN EXTENSIVE SHIELD OF RAIN /SOME HEAVY/ WAS PIVOTING TO THE
NORTHWEST AHEAD OF A POTENT SHORTWAVE PUSHING NORTH ALONG THE
I-95 CORRIDOR.
DUAL POL CORRELATION COEFFICIENT PRODUCT NICELY INDICATES THAT THE
PRECIP HAS CHANGED OVER TO WET SNOW AT THE BEAM HEIGHT OF
2500-3000 MSL JUST TO THE EAST OF THE RDA...WHILE THIS CC PRODUCT
AND SFC OBS INDICATES THAT THE CHANGEOVER HAS REACHED THE GROUND
ACROSS THE NW MTNS. KDUJ AND KBFD CHANGED TO SNOW ABOUT BETWEEN
00Z AND 01Z...WHILE KFIG AND KJST JUST WENT OVER TO ALL SNOW
WITHIN THE PAST 30 MINUTES. SOME WET SNOWFLAKES HAVE BECOME MIXED
IN AROUND THE HAPPY VALLEY AREA...AND A CHANGOVER TO HEAVY WET
SNOW SHOULD OCCUR FROM KAOO TO KUNV BETWEEN 03Z-05Z BASED ON THE
01Z RUC FCST OF MEAN 925-850 MB WET BULB TEMPS DIPPING SLIGHTLY
TO JUST -0.5 TO -1C.
MIXED PHASE PRECIP IS NOTED AT ELEVATIONS AS LOW AS 4500 FT MSL TO
THE EAST THROUGH SSE AT FURTHER DISTANCES AWAY FROM THE RADAR
SITE...HIGHLIGHTING THE STRONG EAST TO WEST MID LEVEL TEMP
GRADIENT FROM THE CENTRAL MTNS TO THE SUSQ VALLEY.
THE SLOWLY DEEPENING AND DIGGING UPPER LOW HEADED OUT OF THE MID
OHIO RIVER VALLEY IS BEGINNING TO CAPTURE DEEP MOISTURE FROM THIS
LEAD SHORT WAVE...AS THE FLOW ALOFT CONTINUES TO BACK THROUGH THE
SOUTH AND BECOMES SERLY.
THE BACK /SWRN EDGE/ EDGE OF THIS CURRENT PRECIP SHIELD WILL
LIKELY EXPAND TO THE SW...AND PIVOT SLOWLY WWD ACROSS THE
COMMONWEALTH OVERNIGHT AND TUESDAY MORNING WITH PRECIP RATES BEING
MAINTAINED OR EVEN INCREASING ACROSS THE CENTRAL MTNS AND
ALLEGHENY PLATEAU...LEADING TO HEAVY WET SNOW WITHIN A FEW
QUASI-SNTRY BANDS OF MDT TO STG FRONTOGENESIS.
NO APPRECIABLE CHANGE WAS MADE TO THE GRIDDED FCST DATABASE WITH
RESPECT TO THE TIMING OF THE RAIN TO SNOW CHANGEOVER...AND
RESULTANT SNOW ACCUMS BY 12Z MONDAY. WILL BE KEEPING A WATCHFUL
EYE THOUGH ON THE HIGH TERRAIN OF SULLIVAN COUNTY /NE OF
KIPT/...SINCE THEY/RE CURRENTLY ONLY IN THE MID 30S WITH WEAK LLVL
COLD ADVECTION CONTINUING. HOWEVER...WARMER AIR SURGING IN ALOFT
FROM THE SSE SHOULD LIMIT ANY CHANGEOVER FOR MUCH OF THE NIGHT TO
JUST A MIX OF WET SNOW AND SLEET AT BEST.
THE RAINFALL IN THE EAST HAS BEEN A STEADY/MODERATELY HEAVY COLD
RAIN FALLING AT A RATE OF GENERALLY 102 TENTHS OF AN INCH PER
HOUR. THE VERY DRY ANTECEDENT CONDITIONS AND EARLY GREEN-UP WILL
ABLE TO EASILY HANDLE THIS RATE...AND TOTAL FCST RAINFALL OF 1-2
INCHES...WITH MINOR TO AT MOST MODERATE RISES ON SMALLER STREAMS
OVER...AND TO THE EAST OF THE SUSQ MAINSTEM.
THE RAIN WILL BE TAPERING OFF IN THE EAST BETWEEN 05Z AND 09Z
MONDAY.
LOW TEMPS OVERNIGHT WILL RANGE FROM THE LOWER 40S IN THE SE
ZONES...TO AROUND 30 ACROSS THE HIGHEST TERRAIN OF THE WEST.
&&
.SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
PERIODS OF MDT TO HEAVY WET SNOW WILL PERSIST ACROSS THE NW MTNS
AND LAUREL HIGHLANDS FOR MUCH OF MONDAY AS THE UPPER LOW TURNS NE
AND LIFTS ACROSS CENTRAL PENN. A MIX OF WET SNOW...AND RAIN IS
STILL EXPECTED IN THE LOWER ELEVS OF THE RIDGE AND VALLEY REGION.
THE SFC/BLYR TEMPS ARE THE TRICK TO THIS FCST - WITH THE SNOW
ACCUMS ALMOST ENTIRELY ELEV /AND SNOWFALL RATE/ DEPENDENT. THE
TIMES OF HEAVY SNOW WILL BE TOUGH TO PINPOINT...AND WILL KEEP IT
BROAD BRUSHED. WILL MAINTAIN THE GOING FCST AS THERE IS NO REASON
TO CHANGE. TEMPS WILL HOVER IN THE LOWER AND MID 30S IN THE
CENTRAL MTS...BUT 30-33 IN THE WRN AND NRN HIGHLANDS. THE ODDITY
OF THIS FCST WILL BE THE RELATIVELY WARM AND DRY AIR THAT GETS
INTO SULLIVAN AND TIOGA COS. ONLY MINOR TWEAKS TO THE SNOW ACCUMS
ARE EXPECTED.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
DEEP TROUGH AND POWERFUL UPPER LOW WILL BE CENTERED OVER THE PA/NY
BORDER MON NIGHT...WITH 500 MB HEIGHTS BELOW 530 FORECAST SOLIDLY BY
THE ECMWF GFS AND NAM. LOW GRADUALLY LIFTS STRAIGHT NORTHWARD AS IT
DEEPENS A BIT FURTHER THROUGH 12Z TUE...THEN BEGINS TO FILL IN ON
TUE UPON ARRIVING IN S CANADA. 987MB SFC LOW ALSO PUSHING NORTHWARD
INTO S NY STATE MON NIGHT WILL FOCUS PRECIP ON ITS COLD SIDE AS 50+
KT COLD CONVEYOR BELT WRAPS AROUND FROM THE NW...WITH LITTLE PRECIP
INDICATED FOR EASTERN HALF OF CWA. SO...ONGOING WINTER WEATHER EVENT
ACROSS WESTERN HALF OF CWA WILL CONTINUE TO BE INTENSE HEADING INTO
MON NIGHT...AND GRADUALLY LESSEN ITS GRIP AS NIGHT PROGRESSES AS
COLD CONVEYOR BELT LIFTS NORTHWARD...RESULTING IN JUST A LIGHTER
SNOW BY 12Z TUE - WHICH WILL LINGER IN THE NORTHERN MTNS POSS INTO
WED.
THE WINTER STORM WARNING/ADVISORY DURATION THROUGH MON NIGHT LOOKS
JUSTIFIED BASED ON QPF FORECASTS/IMPACTS. STORM TOTAL SNOWFALL
OVER MUCH OF THE ALLEGHENIES SHOULD EASILY EXCEED 8 INCHES...WITH
SOME 12-16 INCH AMOUNTS PAINTED IN. SNOWFALL TAPERS OFF FAIRLY
SHARPLY HEADING EAST ACROSS C MTNS...WITH A STRIPE OF 2 TO 5
INCHES IN THE CENTRAL MOUNTAINS - ACCUMULATING MAINLY ON THE
GRASSY SURFACES WITH A LESSER IMPACT ON ROADS. LITTLE ACCUM
EXPECTED IN SUSQ VALLEY...THOUGH SOME SNOW COULD MIX IN ON
OCCASION WITH THE PREDOMINANT PRECIP TYPE OF RAIN - EVEN AS IT
TAPERS TO SHOWERS MON NIGHT INTO TUES.
THE DEEP UPPER TROF LIFTS TO THE NE WED-WED NIGHT...BUT NORTHWEST
FLOW PERSISTS AS ADDITIONAL WEAKER DISTURBANCES ROTATE ACROSS THE
REGION THROUGH THE REMAINDER OF THE WEEK...KEEPING WEATHER SOMEWHAT
UNSETTLED INTO FRI BEFORE A DRIER REGIME MOVES IN. TEMPS LOOK TO BE
BELOW NORMAL FOR MUCH OF THE WEEK.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
STRENGTHENING LOW PRES MOVING UP THE E COAST WILL SPREAD RAIN AND
INCREASINGLY GUSTY NNW WINDS ACROSS CENTRAL PA THIS EVENING. OVR
THE HIGHER TERRAIN OF WESTERN PA...THE RAIN WILL CHANGE TO SNOW
LATER THIS EVENING...ADDING LOW VSBYS TO THE ALREADY POOR FLYING CONDS.
AT 00Z...BFD AND JST WERE THE ONLY CENTRAL PA AIRFIELDS REPORTING
IFR CIGS. HOWEVER...DETERIORATING CIGS EXPECTED OVERNIGHT ACROSS
THE CENTRAL MTNS...AS HEAVIER PRECIP OVERSPREADS THE AREA WITH IFR
CIGS LIKELY AT BOTH UNV AND AOO. AFTER 06Z...EXPECT A DRY SLOT TO
WORK INTO EASTERN PA...CAUSING THE RAIN TO TAPER OFF AT MDT AND
LNS. HOWEVER...SNOW WILL CONTINUE TO FALL AT BFD/JST WITH LIFR
VSBYS/CIGS QUITE POSSIBLE. ACROSS THE RIDGE/VALLEY REGION...AOO
AND UNV WILL LIKELY BE ON THE DIVIDING LINE BTWN RAIN/SNOW LATE
TONIGHT...BUT EITHER WAY...IFR CONDS APPEAR VERY LIKELY DUE TO LOW
CIGS.
AS THE STORM SYSTEM PASSES JUST TO OUR EAST...EXPECT GUSTY NW
WINDS TO BUFFET THE AREA ON MONDAY...ESP OVR THE LAUREL HIGHLANDS
WHERE BUFKIT SOUNDINGS SUPPORT GUSTS TO NR 30KTS AT JST. THE
COLD...MOIST...UPSLOPING FLOW WILL PRODUCE SNOW AND LOW VSBYS/CIGS
AT BFD/JST. SOMEWHAT BETTER CONDS LIKELY AT AOO/UNV...BUT OCNL
SNOW COULD PRODUCE IFR VSBYS AT TIMES. MOST FAVORABLE CONDS WILL
BE ACROSS THE SUSQ VALLEY...WHERE DRYING...DOWNSLOPING FLOW RESULT
IN ONLY SCT -SHRA AND MVFR CIGS.
OUTLOOK...
TUE...LOW CIGS/VSBYS POSS AT BFD IN OCNL SHSN.
WED...NO SIG WX EXPECTED.
THU...RAIN/LOW CIGS POSS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON EDT TUESDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041.
WINTER WEATHER ADVISORY UNTIL 6 AM EDT TUESDAY FOR PAZ019-025-
026-034-035-045.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
654 PM CDT SUN APR 22 2012
.UPDATE...FOR 00Z TAFS.
&&
.AVIATION...
UPPER LEVEL LOW CONTINUES TO DEEPEN THIS EVENING AS ITS MOVES
JUST NORTHEAST OF THE MID-STATE. COLD TEMPS ALOFT AND THE
PRESENCE OF SOME LOW/MID LEVEL MOISTURE CREATING MAINLY VFR
BKN CEILINGS AND ISO-SCT SHOWERS. A DIRECT HIT MAY BRIEFLY
REDUCE VSBYS AS WELL AS BRING VERY SMALL HAIL. THESE SHOWERS
WILL DISSIPATE EARLY THIS EVENING BUT POSSIBLY HANG NEAR THE
PLATEAU LATER TONIGHT. PCPN NOT EXPECTED MONDAY BUT WINDS WILL
AGAIN BECOME QUITE GUSTY. OVERALL...VFR CONDITIONS WILL BE THE
RULE THROUGH THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 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.
&&
$$
07
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1210 PM CDT SAT APR 21 2012
.DISCUSSION...SEE 18Z AVIATION DISCUSSION AND MARINE UPDATE. NO
CHANGES NEEDED AT THIS TIME TO PUBLIC PRODUCTS.
&&
.AVIATION...P6SM SKC. NORTH WINDS DIMINISH AROUND SUNSET THEN
BECOMING EASTERLY DURING THE PERIOD...FIRST AT KLRD THEN ELSEWEHRE
BUT WINDS BELOW 11 KNOTS. NOT MUCH ELSE TO SAY. GFS-MOS SHOWING
4SM BR AT KVCT...WILL HOLD OFF AS CONFIDENCE NOT HIGH.
&&
.MARINE...DECIDED TO GO WITH SCA FOR NORTHERN BAYS AS WINDS AOA 20
KNOTS ESPECIALLY AT PORT OCONNOR AND PALACIOS. WINDS EXPECTED TO
DIMINISH LATE...BUT WILL WATCH AS RUC13 STILL HAD WINDS UP IN THAT
AREA.
&&
.PREV DISCUSSION... /ISSUED 625 AM CDT SAT APR 21 2012/
DISCUSSION...UPDATED FOR 12Z AVIATION.
AVIATION...VFR CONDITIONS WILL PERSIST THROUGH THE PERIOD. GUSTY
WINDS WILL DEVELOP THIS AFTERNOON...BUT THEN DECREASE TO LIGHT
LEVELS ONCE AGAIN TONIGHT.
PREV DISCUSSION... /ISSUED 408 AM CDT SAT APR 21 2012/
SHORT TERM (TODAY THROUGH SUNDAY)...HIGH PRESSURE BUILDING IN WILL KEEP
A GENERALLY QUIET SHORT TERM FORECAST PERIOD. SHOULD BE A RATHER
PLEASANT DAY ACROSS THE AREA...BUT WITH A BIT OF A NORTHEAST
BREEZE...MORE SO ALONG THE BAYS AND OFFSHORE. TEMPERATURES WILL BE
A FEW DEGREES COOLER THAN RECENT DAYS...BUT STILL INTO THE 80S FOR
MOST OF THE AREA. DRIER AIR AND LIGHT WINDS SHOULD ALLOW TEMPS
TONIGHT TO COOL INTO THE 50S FOR MOST OF THE AREA. TEMPERATURES
WARM A FEW DEGREES MORE FOR SUNDAY.
LONG TERM (SUNDAY NIGHT THROUGH SATURDAY)...THE EXTENDED PART OF
THE FORECAST WILL BEGIN WITH UPPER LEVEL RIDGE OVER THE ROCKIES.
THIS WILL MAINTAIN A DRY NORTH NORTHWEST FLOW ACROSS SOUTH TEXAS...
WITH QUIET WEATHER INTO NEXT WEEK. AT THE SURFACE...HIGH PRESSURE
WILL BE BUILDING SOUTHWARD INTO SOUTH TEXAS. LIGHT WINDS AND CLEAR
SKIES SUNDAY NIGHT WILL LEAD TO A COOLER NIGHT WITH TEMPS IN THE MID
AND UPPER 50S IN MOST LOCATIONS. SURFACE HIGH WILL MOVE INTO THE
GULF BY TUESDAY...WHICH WILL BRING A RETURN TO ONSHORE FLOW. A
GRADUAL WARMING TREND WILL OCCUR THROUGH THE WEEK WITH ABOVE NORMAL
NORMAL TEMPERATURES BY TUESDAY/WEDNESDAY. PROSPECTS FOR SHOWERS AND
STORMS WILL BE LOW FOR THE UPCOMING WEEK AS UPPER RIDGING WILL BE
THE DOMINANT WEATHER FEATURE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 79 56 83 60 83 / 0 0 0 0 0
VICTORIA 76 51 81 56 81 / 0 0 0 0 0
LAREDO 85 58 90 64 90 / 0 0 0 0 0
ALICE 81 53 86 57 86 / 0 0 0 0 0
ROCKPORT 76 58 79 62 79 / 0 0 0 0 0
COTULLA 82 53 87 57 87 / 0 0 0 0 0
KINGSVILLE 81 54 85 59 85 / 0 0 0 0 0
NAVY CORPUS 77 62 79 64 80 / 0 0 0 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 3 PM CDT THIS AFTERNOON FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM PORT ARANSAS TO
PORT O`CONNOR.
&&
$$
GW/86...SHORT TERM/AVIATION
TT/89...LONG TERM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
615 PM CDT SUN APR 22 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.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...A 5000 FOOT MID LEVEL CIG WILL BRUSH OVER CENTRAL AND
EAST CENTRAL WISCONSIN MAINLY THIS EVENING...OTHERWISE VFR
CONDITIONS EXPECTED TONIGHT INTO MONDAY. A DEEPENING LOW PRESSURE
SYSTEM WORKING OVER THE EASTERN SEABOARD OF THE U.S. WILL GENERATE
GUSTY NORTH WINDS OVER THE STATE ON MONDAY.
TDH
&&
.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.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
250 PM CDT SAT APR 21 2012
.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 WEAK LOW PRESSURE SYSTEM WILL DROP SOUTHEAST ALONG THE
MISSISSIPPI RIVER VALLEY. DRY EAST FLOW WILL KEEP THE SHOWERS FROM
THE SYSTEM WEST OF THE TAF SITES...BUT WILL SEE SCT-BKN 5-6KFT
CLOUDS MOVE INTO CENTRAL AND NORTH-CENTRAL WISCONSIN THIS AFTERNOON
THROUGH MUCH OF TOMORROW. WILL HAVE A FAIRLY DEEP SATURATED LAYER
OVER N-C WISCONSIN TOMORROW AFTERNOON AND MAY SEE A SPRINKLE OUT OF
IT...BUT CHANCES TOO LOW AT THE MOMENT TO INCLUDE IN THE TAFS.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
104 PM CDT SAT APR 21 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
342 AM CDT SAT APR 21 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TODAY THROUGH
SUNDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING ACROSS MUCH OF THE WESTERN U.S....TROUGHING
ENCOMPASSING MUCH OF THE WESTERN GREAT LAKES REGION...AND AN UPPER
LOW NEAR THE SOUTHWEST LOUISIANA COAST. COMING INTO THE UPPER
TROUGHING WAS A SHORTWAVE OVER NORTHERN NORTH DAKOTA. A LARGE AMOUNT
OF MID AND HIGH CLOUDS WERE PRESENT AHEAD OF THE SHORTWAVE...
STREAMING INTO THE WESTERN PART OF THE FORECAST AREA. RADAR AND
SURFACE OBS SHOW SHOWERS OCCURRING ACROSS EASTERN NORTH DAKOTA...IN
AN AREA OF DPVA AHEAD OF THE SHORTWAVE...WARM ADVECTION NOTED BY
SOUTHWEST WINDS OF 20-25 KT AT 850MB ON ABR AND FGF RADARS...AND
UPPER DIVERGENCE IN THE LEFT EXIT REGION OF A 100 KT JET STREAK OVER
SOUTH DAKOTA. RUC CROSS-SECTIONS SHOW A NICE LOW TO MID-LEVEL
FRONTOGENESIS ZONE THERE TOO WITH A FRONTOLYSIS/FRONTOGENESIS
COUPLET. PRECIPITABLE WATER UP IN EASTERN NORTH DAKOTA AROUND 0.5
INCH PER 00Z SOUNDINGS FROM BIS AND ABR. CLOSER TO THE FORECAST
AREA...A SURFACE HIGH PRESSURE RIDGE IS IN PLACE. MAINLY CLEAR SKIES
UNTIL RECENTLY COMBINED WITH DRY AIR NOTED BY PRECIPITABLE WATER OF
0.24 INCHES ON THE 00Z GRB SOUNDING HAS ALLOWED TEMPERATURES TO DROP
INTO MOSTLY THE 30S...COLDEST OVER CENTRAL WISCONSIN WHERE A FEW
UPPER 20S HAVE OCCURRED.
REGARDING CURRENT FROST/FREEZE HEADLINES...HAVE DROPPED THE FROST
ADVISORY AS CLOUDS SEEM TO BE HAMPERING TEMPS FROM DROPPING ENOUGH
TO PRODUCE WIDESPREAD FROST. CONSIDERED DROPPING FREEZE WARNING TOO
GIVEN CURRENT READINGS...BUT WITH ONLY THE TYPICAL COLD SPOTS IN
CENTRAL WISCONSIN BELOW FREEZING...WILL LET IT CONTINUE FOR NOW.
TODAY AND TONIGHT...FOCUS IS ON THE SHORTWAVE OVER NORTH DAKOTA.
GOOD MODEL AGREEMENT EXISTS OF THE SHORTWAVE TRACKING SOUTHEAST INTO
WESTERN IOWA BY THIS EVENING AND INTO SOUTHERN ILLINOIS LATE
TONIGHT. LOW PRESSURE AREA ACCOMPANYING THE SHORTWAVE TAKES PRETTY
MUCH THE SAME TRACK...WITH AN INVERTED TROUGH LINGERING BACK INTO
SOUTHWEST MINNESOTA AT THE SURFACE AFTER IT PASSES. ALTHOUGH THE
SHORTWAVE AND SURFACE FEATURES ARE TRACKING WEST OF HERE...WE STILL
SEE 30-40 METER 500MB HEIGHT FALLS TODAY...UPPER DIVERGENCE IN THE
LEFT EXIT REGION OF THAT 100 KT JET THIS AFTERNOON...AND THAT
FRONTOGENESIS/FRONTOLYSIS COUPLET IN THE LOW TO MID LEVELS MOVE
THROUGH WESTERN SECTIONS OF THE FORECAST AREA THIS AFTERNOON AND
EVENING. WITH A SURGE OF PRECIPITABLE WATER ACCOMPANYING THE
SYSTEM...UP TO 0.5 INCH OR SO...PRECIPITATION SEEMS TO BE A PRETTY
GOOD BET. HAVE RAISED CHANCES UP TO 100 FOR LOCATIONS MAINLY WEST OF
THE MISSISSIPPI RIVER FOR THIS AFTERNOON AND EVENING. FOR LOCATIONS
NORTH AND EAST OF I-94...THEY ARE ON THE WRONG / SUBSIDENT SIDE OF
THE FRONTOGENETICAL CIRCULATION. THEREFORE...DRY CONDITIONS ARE
MOSTLY EXPECTED THERE. TOTAL QPF AMOUNTS COULD BE UPWARDS OF 0.30
INCHES...A FAR CRY FROM THURSDAY. LOOK FOR PRECIPITATION TO DIMINISH
AFTER MIDNIGHT AS FORCING WEAKENS AND/OR SHIFTS SOUTHEAST OF HERE.
WITH A LOT OF CLOUDS TODAY AND EVENTUALLY RAIN COMING IN THIS
AFTERNOON FOR SOME AREAS...AS WELL AS 850MB TEMPS OF 0 TO -2C...
EXPECTING COOLER TEMPERATURES TODAY. STAYED ON THE COOL SIDE OF
GUIDANCE OUT WEST THEN A BLEND ELSEWHERE. MAY SEE A LITTLE DROP IN
TEMPS IN THE AFTERNOON WHERE IT RAINS DUE TO EVAPORATIVE COOLING. A
BLEND OF GUIDANCE SEEMS REASONABLE FOR LOWS TONIGHT BEING UNDER
PERSISTENT CLOUDS.
SUNDAY AND SUNDAY NIGHT...500MB HEIGHTS PROGGED TO RISE OVER THE
FORECAST AREA DURING MUCH OF THIS PERIOD IN THE WAKE OF
TODAY/TONIGHTS SHORTWAVE...THOUGH SOLIDLY REMAINING IN NORTHWEST
FLOW ALOFT. AS THE HEIGHTS RISE...THE INVERTED TROUGH OVER SOUTHWEST
MINNESOTA WEAKENS AND PUSHES EAST TOWARDS THE MISSISSIPPI RIVER BY
00Z. LOW LEVEL CONVERGENCE ON THIS TROUGH IN CONJUNCTION WITH
DAYTIME HEATING COULD BE ENOUGH TO PRODUCE A FEW SHOWERS...THOUGH
CONFIDENCE IS PRETTY LOW GIVEN THAT CLOUD COVER MAY PERSIST THROUGH
MUCH OF THE DAY. PLUS...AN EASTERLY FLOW IS PROGGED TO DEVELOP OVER
WISCONSIN AHEAD OF HIGH PRESSURE DROPPING DOWN INTO LAKE SUPERIOR.
THIS EASTERLY FLOW WILL DRIVE DRY AIR INTO THE AREA. MOST MODELS
ARE EITHER DRY OR CLOSE TO IT WITH QPF FIELDS. THEREFORE...HAVE
REDUCED PRECIPITATION CHANCES BY 10 PERCENT AND SHIFTED THE MAX AREA
WESTWARD CLOSER TO THE INVERTED TROUGH. ANY PRECIP WILL END BY 00Z
MONDAY AS THE SURFACE RIDGE BUILDS INTO THE AREA. TEMPERATURES ARE A
LITTLE TRICKY FOR SUNDAY NIGHT AS MODELS NOW SUGGEST SOME CLOUDS
UP AROUND THE DULUTH AREA DROPPING SOUTH WITH THE SURFACE RIDGE. AS
SUCH...FOR NOW LEANED A LITTLE CLOSER TO A MODEL CONSENSUS...SAME
TOO FOR HIGHS ON SUNDAY. CERTAINLY IF WE CLEAR OUT MORE THAN
EXPECTED...FROST/FREEZE CONDITIONS MAY BECOME A WORRY FOR SUNDAY
NIGHT.
MONDAY AND MONDAY NIGHT...THE FORECAST AREA IS EXPECTED TO BE STUCK
BETWEEN STRONG RIDGING IN THE WESTERN U.S. AND DEEP TROUGHING OVER
THE EASTERN U.S.. THE POSITION FAVORS HIGH PRESSURE AT THE
SURFACE...WHICH HOLDS TRUE FOR THE DAY MONDAY. THERE ARE SUGGESTIONS
OF A SLIGHT EASTWARD PUSH OF THE UPPER RIDGE MONDAY NIGHT...WHICH IN
TURN CAUSES A WARM ADVECTION SURGE INTO THE FORECAST AREA. 850MB
TEMPS CLIMB FROM 2-4C AT 00Z TUESDAY TO 6-10C AT 12Z TUESDAY. THE
21.00Z GFS/NAM DEVELOP QPF WITH THIS SURGE OF WARM ADVECTION OVER
NORTHERN AND EASTERN WISCONSIN...POSSIBLY CLIPPING TAYLOR AND ADAMS
COUNTIES. FOR NOW HAVE DECIDED TO KEEP IT DRY IN AGREEMENT WITH THE
ECMWF AND PREVIOUS FORECASTS...THINKING TOO THAT THERE IS NOT MUCH
MOISTURE TO WORK WITH AFTER BEING UNDER THE SURFACE HIGH PRESSURE
RIDGE. SOMETHING TO WATCH...THOUGH. WITH MAINLY SUNNY SKIES ON
MONDAY AND THE WARMING 850MB TEMPS...DEEP MIXING SHOULD OCCUR WITH
HIGHS TOPPING OUT IN THE UPPER 50S/LOW 60S. INCREASING SOUTHWEST
FLOW AHEAD OF A SURFACE TROUGH DROPPING DOWN INTO NORTHERN WISCONSIN
MONDAY NIGHT AND THE WARMER 850MB TEMPS COMING IN SHOULD HELP TO
PRODUCE A WARMER NIGHT.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
342 AM CDT SAT APR 21 2012
BETTER AGREEMENT EXISTS WITH THE 21.00Z ECMWF/GFS/CANADIAN AND GFS
ENSEMBLES TODAY THAN SEEN YESTERDAY. THE WESTERN RIDGE AND EASTERN
TROUGH PATTERN SEEN RECENTLY LOOKS TO CONTINUE THROUGH MUCH OF THE
LONG TERM FORECAST...THOUGH TOWARDS FRIDAY SOME FAIRLY DEEP
TROUGHING DEVELOPS ALONG THE WEST COAST OF THE U.S. TO HELP PUSH
THAT WESTERN RIDGE EASTWARD. WE GET A BRIEF TASTE OF THE WARM AIR
OUT OF THE UPPER RIDGE TUESDAY AND TUESDAY NIGHT...AHEAD OF A LOW
PRESSURE AREA DEEPENING OVER THE DAKOTAS AND SLIDING DOWN INTO IOWA.
WARM ADVECTION AHEAD OF THIS LOW SHOULD PRODUCE SOME SHOWERS AND
POSSIBLY THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY. LOCATIONS WEST
OF THE MISSISSIPPI RIVER SEEM MOST FAVORABLE RIGHT NOW FOR
PRECIPITATION. HIGH PRESSURE THEN DROPS IN FROM CANADA FOR WEDNESDAY
NIGHT THROUGH FRIDAY NIGHT...WITH MAYBE A BRIEF DRY COLD FRONT
MOVING THROUGH BETWEEN THEN ON THURSDAY NIGHT. THEREFORE...WHEN IT
COMES TO TEMPERATURES...WARMEST READINGS ARE EXPECTED ON TUESDAY AND
WEDNESDAY. MAY HAVE TO DEAL WITH FROST/FREEZE CONDITIONS THURSDAY
NIGHT OR FRIDAY NIGHT OVER CENTRAL WISCONSIN. SOMETHING TO WATCH.
&&
.AVIATION...THROUGH 18Z SUNDAY
104 PM CDT SAT APR 21 2012
AS OF 18Z SATURDAY...BAND OF MOSTLY VFR CEILINGS WITH SCATTERED
RAIN SHOWERS ALONG THE I-35 CORRIDOR IN MINNESOTA...MOVING SLOWLY
EASTWARD TOWARDS KRST/KLSE..ALL ASSOCIATED WITH SURFACE LOW IN
NORTHWEST MINNESOTA. EXPECT PRECIPITATION TO MAKE IT TO KRST BY MID
AFTERNOON...WHILE DRIER AIR IN THE LOW LEVELS ALONG AND EAST OF
THE MISSISSIPPI RIVER SHOULD KEEP BULK OF PRECIPITATION AWAY FROM
KLSE SO KEPT A SMALL WINDOW OF SHOWERS TONIGHT AND CONTINUED THE
VFR CONDITIONS.
THE SURFACE LOW SLIDES SOUTHEAST TONIGHT...BRINGING MVFR CEILINGS
AT KRST...IN THE 1500 TO 2000 FT RANGE. THERE IS A CHANCE FOR A
PERIOD OF IFR CEILINGS...BUT CONFIDENCE IS LOW FOR AN EXTENDED
PERIOD...AS DRIER AIR BUILDS SLIGHTLY WEST AND WILL TRY TO
COUNTERACT ANY CEILING LOWERING. SOMETHING TO MONITOR THIS
AFTERNOON/EVENING.
FOR SUNDAY...HIGH PRESSURE BUILDS IN AND CEILINGS WILL LIFT TO
VFR AT KRST. LATEST MODEL RH FIELDS SUGGEST BAND OF LOW CLOUDS POSSIBLE
TO THE WEST ACROSS SOUTHWEST MINNESOTA ASSOCIATED WITH THE
DEPARTING LOW...BUT FOR NOW FEEL THE DRY AIR PUSH SHOULD KEEP
THESE CLOUDS TO THE WEST OF THE TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
342 AM CDT SAT APR 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....ZT
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1101 AM CDT SAT APR 21 2012
.UPDATE...
LAKE CLOUDS FORMED ALONG A CONVERGENCE ZONE NEAR THE LAKESHORE
THIS MORNING. EXPECT THESE CLOUDS TO MIX OUT NEAR THE SHORELINE
AND ADVECT INLAND UP TO THE KETTLE MORRAINE LATE THIS
MORNING...THEN MIX OUT AFTER 18Z. CU RULE GENERALLY SUPPORTIVE OF
SCATTERED TO BROKEN CLOUDS DURING THE AFTERNOON FOR INLAND
LOCATIONS...EXCEPT FOR THE NAM. RUC SNDGS ALSO SHOW POTENTIAL FOR
SCATTERED CU ACROSS MUCH OF SOUTH CENTRAL WI.
MAX TEMPS LOOK TO BE ON TRACK FOR TODAY...WITH HIGHS IN THE UPPER
40S NEAR THE LAKE AND MID 50S WELL INLAND. MODIFIED CLOUD COVER A
BIT FOR TODAY BUT OTHERWISE NO MAJOR CHANGES TO THE GOING FORECAST.
STILL EXPECTING MID CLOUDS TO SPREAD INTO SOUTH CENTRAL WI THIS
EVENING AS LOW PRESSURE TRACKS FROM MN TO EASTERN IOWA. 12Z MODEL
GUIDANCE IS CONTINUING TO KEEP CHANCES FOR RAIN WITH THAT SYSTEM
VERY SLIM IN THE WESTERN FORECAST AREA TONIGHT. MAY BE ABLE TO CUT
BACK ON THOSE SMALL CHANCES EVEN MORE.
&&
.AVIATION/18Z TAFS/...
LAKE CLOUDS WILL SPREAD INLAND TO THE KETTLE MORRAINE LATE THIS
MORNING...THEN GRADUALLY MIX OUT BY OR SHORTLY AFTER NOON. DIURNAL
CUMULUS CLOUDS SHOULD DEVELOP INLAND THIS AFTERNOON. UNCERTAINTY OF
BROKEN OR SCATTERED...BUT THEY WILL BE WELL INTO THE VFR CATEGORY.
LOW PRESSURE WILL CROSS MN AND EASTERN IOWA TODAY AND TONIGHT. MID
CLOUDS MAY SPREAD INTO SOUTH CENTRAL WI AND REACH MSN THIS
EVENING...BUT PRECIP CHANCES WILL BE IN FAR WESTERN WI AND TAF SITES
WILL REMAIN DRY THROUGH THE PERIOD DUE TO THE DRY EASTERLY FLOW AND
HIGH PRESSURE RIDGE IN PLACE.
CHANCE FOR VFR BROKEN DIURNAL CUMULUS CLOUDS ONCE AGAIN SUNDAY SOUTH
CENTRAL. NORTHEAST TO EAST WINDS WILL BE A LITTLE HIGHER NEAR THE
SHORELINE ON SUNDAY THAN TODAY.
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT SAT APR 21 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM TO HIGH.
TEMPERATURES HAVE NOT FALLEN OFF AS QUICKLY AS EXPECTED...AND WITH
CLOUDS MOVING IN...DO NO THINK WE WILL RADIATE OUT TO 28F OR LESS
SO WILL CANCEL THE FREEZE WARNING.
BETTER PRECIPITATION CHANCES TIED TO SURFACE MOISTURE AXIS ALONG AND
JUST TO THE EAST OF THE TRACK OF THE SURFACE LOW...AND 850-700MB
LAYER FRONTOGENETIC FORCING AND ISENTROPIC LIFT OVER BAROCLINIC ZONE
THAT STAYS ALONG AND WEST OF THE MISSISSIPPI RIVER TODAY AND
TONIGHT. HIGHEST 850-700 MB Q-VECTOR CONVERGENCE REFLECTING WARM AIR
ADVECTION AS MAIN CONTRIBUTOR IN THIS LAYER WITH FOCUSED
CROSS-ISOTHERM FLOW JUST AHEAD OF SHORT WAVE. WILL LIMIT SLIGHT
CHANCE/CHANCE POPS TO FAR WEST.
SOME OMEGA ABOVE 600 MB OVER THE REMAINDER OF SOUTHERN WISCONSIN
CENTERED AROUND 00Z SUNDAY WITH WEAK UPPER DIVERGENCE WITH LEFT EXIT
REGION NOTED ON GFS AROUND 00Z SUNDAY...AS WELL AS Q-VECTOR
CONVERGENCE ABOVE 700 MB DUE TO DIFFERENTIAL VORTICITY ADVECTION.
HOWEVER DRY EASTERLY FLOW KEEPS LAYER BELOW 800 MB DRY AS FAR WEST
AS MADISON WITH LIFT DROPPING SOUTH OUT OF THE STATE BY MID-EVENING.
NORTHEAST TO EAST WINDS OFF THE LAKE WILL HOLD HIGHS IN THE MID TO
UPPER 40S EAST OF THE KETTLE MORAINE...WITH MODEL SOUNDINGS AND 925
MB TEMPERATURES SUPPORTING LOW TO MID 50S INLAND WITH THE WARMEST
TEMPERATURES IN THE WEST UNDER THE THERMAL RIDGE AHEAD OF THE SHORT
WAVE.
SUNDAY - CONFIDENCE...MEDIUM
LOW LEVEL EASTERLY FLOW BECOMES NORTHEAST WITH TIME. UPPER FLOW NNW
AND BROADLY CYCLONIC. DELTA T VALUES NOT HIGH ENOUGH TO GET EXCITED
ABOUT LAKE CLOUDS. WEAK RIPPLE IN THE FLOW. HARD TO LATCH ONTO MUCH
IN THE BUFKIT SOUNDINGS. MID LEVELS MOISTEN UP A BIT MORE SUNDAY
NIGHT. GUID POPS ARE SINGLE DIGITS AND WILL MAINTAIN DRY FORECAST.
MONDAY - CONFIDENCE...MEDIUM
A BIT MORE NVA BUILDS IN WITHIN THE NNW 500 MILLIBAR FLOW. 850 TEMPS
MODIFY A SMIDGE AND LOW LEVEL FLOW TURNS MORE NORTHWEST. GRADIENT
WEAK ENOUGH TO BELIEVE WINDS MAY BECOME ONSHORE.
TUESDAY AND WEDNESDAY - CONFIDENCE...LOW TO MEDIUM
BEST POTENTIAL FOR SOME UNSETTLED CONDITIONS. UPPER FLOW BECOMES
NORTHWEST AND WARM AIR ADVECTION INCREASES TUESDAY. 500 MILLIBAR
SHORT WAVE THEN AFFECTS THE AREA WEDNESDAY. BUFKIT SOUNDINGS DO NOT
LOOK OVERLY UNSTABLE AND GIVEN THE NORTHWEST FLOW AND AND LACK OF A
FAVORABLE MOISTURE RETURN INTO SOUTHERN WI THIS SEEMS REASONABLE.
BULK OF MODELS KEEP HEAVIEST PRECIP TO OUR SOUTH THE WAVE...THOUGH
00Z GEMNH A BIT MORE ROBUST FOR SRN WI.
THURSDAY - CONFIDENCE...LOW
NORTHWEST UPPER FLOW PERSISTS WITH 00Z ECMWF SUGGESTING A MUCH
SLOWER FROPA THAN WHAT THE GFS IS SUGGESTING. 5-7C DIFFERENCE IN 850
TEMPS. ECMWF DOES COOL THINGS DOWN THEN FOR THURSDAY NIGHT. APPEARS
TO BE A DRY DAY WHETHER LOOKING AT THE GFS OR ECMWF.
FRIDAY - CONFIDENCE...LOW
00Z ECMWF MUCH MORE AGGRESSIVE WITH RETURN WAA PRECIP. GFS HOLDS
THEN BACK FURTHER TO THE WEST. DPROG FOR THIS TIME FRAME SHOWS THE
GFS BEING A BIT MORE CONSISTENT WITH HIGH PRESSURE IN CONTROL...WHILE
THE ECMWF HAS BEEN A BIT MORE CHAOTIC. WILL STICK WITH THE QUIET
ALLBLEND POPS FOR NOW AND SEE IF THE ECMWF TAKES ON MORE OF A
CONSISTENT LOOK WITH THIS QUICK RETURN OF WAA PRECIP.
AVIATION/12Z TAFS/...WILL KEEP PRECIPITATION OUT OF TAF SITES WITH
SHORT WAVE AS BETTER FORCING AND SATURATION STAYS TO THE WEST
CLOSER TO THE MISSISSIPPI RIVER. WILL SEE AN INCREASE IN MID TO
HIGH LEVEL CLOUDS TODAY ...WITH SOME LOWER CU AT KMSN THIS EVENING
BUT REMAINING AT VFR LEVELS.
MARINE...WILL BE CANCELLING THE SMALL CRAFT ADVISORY FOR NORTHERN ZONES...
AND WILL PROBABLY END THE ADVISORY IN THE SOUTHERN ZONES EARLY AS
WINDS ARE EASING AND WAVES SUBSIDING A BIT FASTER THAN EARLIER
EXPECTED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...COLLAR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
632 AM CDT SAT APR 21 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
342 AM CDT SAT APR 21 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TODAY THROUGH
SUNDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING ACROSS MUCH OF THE WESTERN U.S....TROUGHING
ENCOMPASSING MUCH OF THE WESTERN GREAT LAKES REGION...AND AN UPPER
LOW NEAR THE SOUTHWEST LOUISIANA COAST. COMING INTO THE UPPER
TROUGHING WAS A SHORTWAVE OVER NORTHERN NORTH DAKOTA. A LARGE AMOUNT
OF MID AND HIGH CLOUDS WERE PRESENT AHEAD OF THE SHORTWAVE...
STREAMING INTO THE WESTERN PART OF THE FORECAST AREA. RADAR AND
SURFACE OBS SHOW SHOWERS OCCURRING ACROSS EASTERN NORTH DAKOTA...IN
AN AREA OF DPVA AHEAD OF THE SHORTWAVE...WARM ADVECTION NOTED BY
SOUTHWEST WINDS OF 20-25 KT AT 850MB ON ABR AND FGF RADARS...AND
UPPER DIVERGENCE IN THE LEFT EXIT REGION OF A 100 KT JET STREAK OVER
SOUTH DAKOTA. RUC CROSS-SECTIONS SHOW A NICE LOW TO MID-LEVEL
FRONTOGENESIS ZONE THERE TOO WITH A FRONTOLYSIS/FRONTOGENESIS
COUPLET. PRECIPITABLE WATER UP IN EASTERN NORTH DAKOTA AROUND 0.5
INCH PER 00Z SOUNDINGS FROM BIS AND ABR. CLOSER TO THE FORECAST
AREA...A SURFACE HIGH PRESSURE RIDGE IS IN PLACE. MAINLY CLEAR SKIES
UNTIL RECENTLY COMBINED WITH DRY AIR NOTED BY PRECIPITABLE WATER OF
0.24 INCHES ON THE 00Z GRB SOUNDING HAS ALLOWED TEMPERATURES TO DROP
INTO MOSTLY THE 30S...COLDEST OVER CENTRAL WISCONSIN WHERE A FEW
UPPER 20S HAVE OCCURRED.
REGARDING CURRENT FROST/FREEZE HEADLINES...HAVE DROPPED THE FROST
ADVISORY AS CLOUDS SEEM TO BE HAMPERING TEMPS FROM DROPPING ENOUGH
TO PRODUCE WIDESPREAD FROST. CONSIDERED DROPPING FREEZE WARNING TOO
GIVEN CURRENT READINGS...BUT WITH ONLY THE TYPICAL COLD SPOTS IN
CENTRAL WISCONSIN BELOW FREEZING...WILL LET IT CONTINUE FOR NOW.
TODAY AND TONIGHT...FOCUS IS ON THE SHORTWAVE OVER NORTH DAKOTA.
GOOD MODEL AGREEMENT EXISTS OF THE SHORTWAVE TRACKING SOUTHEAST INTO
WESTERN IOWA BY THIS EVENING AND INTO SOUTHERN ILLINOIS LATE
TONIGHT. LOW PRESSURE AREA ACCOMPANYING THE SHORTWAVE TAKES PRETTY
MUCH THE SAME TRACK...WITH AN INVERTED TROUGH LINGERING BACK INTO
SOUTHWEST MINNESOTA AT THE SURFACE AFTER IT PASSES. ALTHOUGH THE
SHORTWAVE AND SURFACE FEATURES ARE TRACKING WEST OF HERE...WE STILL
SEE 30-40 METER 500MB HEIGHT FALLS TODAY...UPPER DIVERGENCE IN THE
LEFT EXIT REGION OF THAT 100 KT JET THIS AFTERNOON...AND THAT
FRONTOGENESIS/FRONTOLYSIS COUPLET IN THE LOW TO MID LEVELS MOVE
THROUGH WESTERN SECTIONS OF THE FORECAST AREA THIS AFTERNOON AND
EVENING. WITH A SURGE OF PRECIPITABLE WATER ACCOMPANYING THE
SYSTEM...UP TO 0.5 INCH OR SO...PRECIPITATION SEEMS TO BE A PRETTY
GOOD BET. HAVE RAISED CHANCES UP TO 100 FOR LOCATIONS MAINLY WEST OF
THE MISSISSIPPI RIVER FOR THIS AFTERNOON AND EVENING. FOR LOCATIONS
NORTH AND EAST OF I-94...THEY ARE ON THE WRONG / SUBSIDENT SIDE OF
THE FRONTOGENETICAL CIRCULATION. THEREFORE...DRY CONDITIONS ARE
MOSTLY EXPECTED THERE. TOTAL QPF AMOUNTS COULD BE UPWARDS OF 0.30
INCHES...A FAR CRY FROM THURSDAY. LOOK FOR PRECIPITATION TO DIMINISH
AFTER MIDNIGHT AS FORCING WEAKENS AND/OR SHIFTS SOUTHEAST OF HERE.
WITH A LOT OF CLOUDS TODAY AND EVENTUALLY RAIN COMING IN THIS
AFTERNOON FOR SOME AREAS...AS WELL AS 850MB TEMPS OF 0 TO -2C...
EXPECTING COOLER TEMPERATURES TODAY. STAYED ON THE COOL SIDE OF
GUIDANCE OUT WEST THEN A BLEND ELSEWHERE. MAY SEE A LITTLE DROP IN
TEMPS IN THE AFTERNOON WHERE IT RAINS DUE TO EVAPORATIVE COOLING. A
BLEND OF GUIDANCE SEEMS REASONABLE FOR LOWS TONIGHT BEING UNDER
PERSISTENT CLOUDS.
SUNDAY AND SUNDAY NIGHT...500MB HEIGHTS PROGGED TO RISE OVER THE
FORECAST AREA DURING MUCH OF THIS PERIOD IN THE WAKE OF
TODAY/TONIGHTS SHORTWAVE...THOUGH SOLIDLY REMAINING IN NORTHWEST
FLOW ALOFT. AS THE HEIGHTS RISE...THE INVERTED TROUGH OVER SOUTHWEST
MINNESOTA WEAKENS AND PUSHES EAST TOWARDS THE MISSISSIPPI RIVER BY
00Z. LOW LEVEL CONVERGENCE ON THIS TROUGH IN CONJUNCTION WITH
DAYTIME HEATING COULD BE ENOUGH TO PRODUCE A FEW SHOWERS...THOUGH
CONFIDENCE IS PRETTY LOW GIVEN THAT CLOUD COVER MAY PERSIST THROUGH
MUCH OF THE DAY. PLUS...AN EASTERLY FLOW IS PROGGED TO DEVELOP OVER
WISCONSIN AHEAD OF HIGH PRESSURE DROPPING DOWN INTO LAKE SUPERIOR.
THIS EASTERLY FLOW WILL DRIVE DRY AIR INTO THE AREA. MOST MODELS
ARE EITHER DRY OR CLOSE TO IT WITH QPF FIELDS. THEREFORE...HAVE
REDUCED PRECIPITATION CHANCES BY 10 PERCENT AND SHIFTED THE MAX AREA
WESTWARD CLOSER TO THE INVERTED TROUGH. ANY PRECIP WILL END BY 00Z
MONDAY AS THE SURFACE RIDGE BUILDS INTO THE AREA. TEMPERATURES ARE A
LITTLE TRICKY FOR SUNDAY NIGHT AS MODELS NOW SUGGEST SOME CLOUDS
UP AROUND THE DULUTH AREA DROPPING SOUTH WITH THE SURFACE RIDGE. AS
SUCH...FOR NOW LEANED A LITTLE CLOSER TO A MODEL CONSENSUS...SAME
TOO FOR HIGHS ON SUNDAY. CERTAINLY IF WE CLEAR OUT MORE THAN
EXPECTED...FROST/FREEZE CONDITIONS MAY BECOME A WORRY FOR SUNDAY
NIGHT.
MONDAY AND MONDAY NIGHT...THE FORECAST AREA IS EXPECTED TO BE STUCK
BETWEEN STRONG RIDGING IN THE WESTERN U.S. AND DEEP TROUGHING OVER
THE EASTERN U.S.. THE POSITION FAVORS HIGH PRESSURE AT THE
SURFACE...WHICH HOLDS TRUE FOR THE DAY MONDAY. THERE ARE SUGGESTIONS
OF A SLIGHT EASTWARD PUSH OF THE UPPER RIDGE MONDAY NIGHT...WHICH IN
TURN CAUSES A WARM ADVECTION SURGE INTO THE FORECAST AREA. 850MB
TEMPS CLIMB FROM 2-4C AT 00Z TUESDAY TO 6-10C AT 12Z TUESDAY. THE
21.00Z GFS/NAM DEVELOP QPF WITH THIS SURGE OF WARM ADVECTION OVER
NORTHERN AND EASTERN WISCONSIN...POSSIBLY CLIPPING TAYLOR AND ADAMS
COUNTIES. FOR NOW HAVE DECIDED TO KEEP IT DRY IN AGREEMENT WITH THE
ECMWF AND PREVIOUS FORECASTS...THINKING TOO THAT THERE IS NOT MUCH
MOISTURE TO WORK WITH AFTER BEING UNDER THE SURFACE HIGH PRESSURE
RIDGE. SOMETHING TO WATCH...THOUGH. WITH MAINLY SUNNY SKIES ON
MONDAY AND THE WARMING 850MB TEMPS...DEEP MIXING SHOULD OCCUR WITH
HIGHS TOPPING OUT IN THE UPPER 50S/LOW 60S. INCREASING SOUTHWEST
FLOW AHEAD OF A SURFACE TROUGH DROPPING DOWN INTO NORTHERN WISCONSIN
MONDAY NIGHT AND THE WARMER 850MB TEMPS COMING IN SHOULD HELP TO
PRODUCE A WARMER NIGHT.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
342 AM CDT SAT APR 21 2012
BETTER AGREEMENT EXISTS WITH THE 21.00Z ECMWF/GFS/CANADIAN AND GFS
ENSEMBLES TODAY THAN SEEN YESTERDAY. THE WESTERN RIDGE AND EASTERN
TROUGH PATTERN SEEN RECENTLY LOOKS TO CONTINUE THROUGH MUCH OF THE
LONG TERM FORECAST...THOUGH TOWARDS FRIDAY SOME FAIRLY DEEP
TROUGHING DEVELOPS ALONG THE WEST COAST OF THE U.S. TO HELP PUSH
THAT WESTERN RIDGE EASTWARD. WE GET A BRIEF TASTE OF THE WARM AIR
OUT OF THE UPPER RIDGE TUESDAY AND TUESDAY NIGHT...AHEAD OF A LOW
PRESSURE AREA DEEPENING OVER THE DAKOTAS AND SLIDING DOWN INTO IOWA.
WARM ADVECTION AHEAD OF THIS LOW SHOULD PRODUCE SOME SHOWERS AND
POSSIBLY THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY. LOCATIONS WEST
OF THE MISSISSIPPI RIVER SEEM MOST FAVORABLE RIGHT NOW FOR
PRECIPITATION. HIGH PRESSURE THEN DROPS IN FROM CANADA FOR WEDNESDAY
NIGHT THROUGH FRIDAY NIGHT...WITH MAYBE A BRIEF DRY COLD FRONT
MOVING THROUGH BETWEEN THEN ON THURSDAY NIGHT. THEREFORE...WHEN IT
COMES TO TEMPERATURES...WARMEST READINGS ARE EXPECTED ON TUESDAY AND
WEDNESDAY. MAY HAVE TO DEAL WITH FROST/FREEZE CONDITIONS THURSDAY
NIGHT OR FRIDAY NIGHT OVER CENTRAL WISCONSIN. SOMETHING TO WATCH.
&&
.AVIATION...TODAY AND TONIGHT
632 AM CDT SAT APR 21 2012
SFC LOW AND MID LEVEL SHORTWAVE OVER THE EASTERN DAKOTAS THIS
MORNING WILL DROP SOUTHEAST ACROSS MN/IA TODAY/TONIGHT...ENDING UP
IN EASTERN MO BY 12Z SUN. MOISTURE/CLOUDS WILL INCREASE OVER THE
AREA TODAY AND CIGS WILL GRADUALLY LOWER THRU THE DAY. STRONGER
OF THE LOWER LEVEL FORCING/LIFT AND DEEPER MOISTURE WITH THIS SYSTEM
DROPS SOUTHEAST ACROSS MN INTO EASTERN IA TODAY/TONIGHT...STAYING
MAINLY ALONG/WEST OF THE MS RIVER. A DRIER SOUTHEAST SFC-925MB FLOW
PERSISTS ACROSS MUCH OF WI/IL EAST OF THE MS RIVER. THIS SETS UP
KLSE AS A BATTLE ZONE BETWEEN THE INCREASING MOISTURE/LIFT TO THE
WEST AND DRIER AIR TO THE EAST...MAKING FOR A MORE DIFFICULT...LOWER
CONFIDENCE TAF. DID BRING SOME -SHRA INTO KLSE FOR THE LATE
AFTERNOON/EVENING HOURS WITH MINOR VSBY RESTRICTION EARLY THIS
EVENING...WITH THE DRIER SFC-925MB FLOW EXPECTED TO KEEP THE CIGS
VFR AT KLSE. KRST ENDS UP UNDER SOME OF THE STRONGER LIFT/DEEPER
MOISTURE LATER THIS AFTERNOON/EVENING WITH MVFR CIGS/VSBYS EXPECTED
IN -SHRA/BR THRU THE LATE AFTERNOON/EVENING HOURS. THE STRONGER OF
THE LIFT PASSES SOUTH OF THE AREA AFTER MIDNIGHT WITH THE DRIER LOW
LEVEL EAST TO SOUTHEAST FLOW LOOKING TO THEN PUSH WESTWARD ACROSS
THE AREA...WITH IMPROVING CIGS/VSBYS OVERNIGHT INTO SUN MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
342 AM CDT SAT APR 21 2012
WI...FREEZE WARNING UNTIL 8 AM CDT THIS MORNING 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
342 AM CDT SAT APR 21 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
342 AM CDT SAT APR 21 2012
MAIN FORECAST CONCERNS ARE ON PRECIPITATION CHANCES TODAY THROUGH
SUNDAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING ACROSS MUCH OF THE WESTERN U.S....TROUGHING
ENCOMPASSING MUCH OF THE WESTERN GREAT LAKES REGION...AND AN UPPER
LOW NEAR THE SOUTHWEST LOUISIANA COAST. COMING INTO THE UPPER
TROUGHING WAS A SHORTWAVE OVER NORTHERN NORTH DAKOTA. A LARGE AMOUNT
OF MID AND HIGH CLOUDS WERE PRESENT AHEAD OF THE SHORTWAVE...
STREAMING INTO THE WESTERN PART OF THE FORECAST AREA. RADAR AND
SURFACE OBS SHOW SHOWERS OCCURRING ACROSS EASTERN NORTH DAKOTA...IN
AN AREA OF DPVA AHEAD OF THE SHORTWAVE...WARM ADVECTION NOTED BY
SOUTHWEST WINDS OF 20-25 KT AT 850MB ON ABR AND FGF RADARS...AND
UPPER DIVERGENCE IN THE LEFT EXIT REGION OF A 100 KT JET STREAK OVER
SOUTH DAKOTA. RUC CROSS-SECTIONS SHOW A NICE LOW TO MID-LEVEL
FRONTOGENESIS ZONE THERE TOO WITH A FRONTOLYSIS/FRONTOGENESIS
COUPLET. PRECIPITABLE WATER UP IN EASTERN NORTH DAKOTA AROUND 0.5
INCH PER 00Z SOUNDINGS FROM BIS AND ABR. CLOSER TO THE FORECAST
AREA...A SURFACE HIGH PRESSURE RIDGE IS IN PLACE. MAINLY CLEAR SKIES
UNTIL RECENTLY COMBINED WITH DRY AIR NOTED BY PRECIPITABLE WATER OF
0.24 INCHES ON THE 00Z GRB SOUNDING HAS ALLOWED TEMPERATURES TO DROP
INTO MOSTLY THE 30S...COLDEST OVER CENTRAL WISCONSIN WHERE A FEW
UPPER 20S HAVE OCCURRED.
REGARDING CURRENT FROST/FREEZE HEADLINES...HAVE DROPPED THE FROST
ADVISORY AS CLOUDS SEEM TO BE HAMPERING TEMPS FROM DROPPING ENOUGH
TO PRODUCE WIDESPREAD FROST. CONSIDERED DROPPING FREEZE WARNING TOO
GIVEN CURRENT READINGS...BUT WITH ONLY THE TYPICAL COLD SPOTS IN
CENTRAL WISCONSIN BELOW FREEZING...WILL LET IT CONTINUE FOR NOW.
TODAY AND TONIGHT...FOCUS IS ON THE SHORTWAVE OVER NORTH DAKOTA.
GOOD MODEL AGREEMENT EXISTS OF THE SHORTWAVE TRACKING SOUTHEAST INTO
WESTERN IOWA BY THIS EVENING AND INTO SOUTHERN ILLINOIS LATE
TONIGHT. LOW PRESSURE AREA ACCOMPANYING THE SHORTWAVE TAKES PRETTY
MUCH THE SAME TRACK...WITH AN INVERTED TROUGH LINGERING BACK INTO
SOUTHWEST MINNESOTA AT THE SURFACE AFTER IT PASSES. ALTHOUGH THE
SHORTWAVE AND SURFACE FEATURES ARE TRACKING WEST OF HERE...WE STILL
SEE 30-40 METER 500MB HEIGHT FALLS TODAY...UPPER DIVERGENCE IN THE
LEFT EXIT REGION OF THAT 100 KT JET THIS AFTERNOON...AND THAT
FRONTOGENESIS/FRONTOLYSIS COUPLET IN THE LOW TO MID LEVELS MOVE
THROUGH WESTERN SECTIONS OF THE FORECAST AREA THIS AFTERNOON AND
EVENING. WITH A SURGE OF PRECIPITABLE WATER ACCOMPANYING THE
SYSTEM...UP TO 0.5 INCH OR SO...PRECIPITATION SEEMS TO BE A PRETTY
GOOD BET. HAVE RAISED CHANCES UP TO 100 FOR LOCATIONS MAINLY WEST OF
THE MISSISSIPPI RIVER FOR THIS AFTERNOON AND EVENING. FOR LOCATIONS
NORTH AND EAST OF I-94...THEY ARE ON THE WRONG / SUBSIDENT SIDE OF
THE FRONTOGENETICAL CIRCULATION. THEREFORE...DRY CONDITIONS ARE
MOSTLY EXPECTED THERE. TOTAL QPF AMOUNTS COULD BE UPWARDS OF 0.30
INCHES...A FAR CRY FROM THURSDAY. LOOK FOR PRECIPITATION TO DIMINISH
AFTER MIDNIGHT AS FORCING WEAKENS AND/OR SHIFTS SOUTHEAST OF HERE.
WITH A LOT OF CLOUDS TODAY AND EVENTUALLY RAIN COMING IN THIS
AFTERNOON FOR SOME AREAS...AS WELL AS 850MB TEMPS OF 0 TO -2C...
EXPECTING COOLER TEMPERATURES TODAY. STAYED ON THE COOL SIDE OF
GUIDANCE OUT WEST THEN A BLEND ELSEWHERE. MAY SEE A LITTLE DROP IN
TEMPS IN THE AFTERNOON WHERE IT RAINS DUE TO EVAPORATIVE COOLING. A
BLEND OF GUIDANCE SEEMS REASONABLE FOR LOWS TONIGHT BEING UNDER
PERSISTENT CLOUDS.
SUNDAY AND SUNDAY NIGHT...500MB HEIGHTS PROGGED TO RISE OVER THE
FORECAST AREA DURING MUCH OF THIS PERIOD IN THE WAKE OF
TODAY/TONIGHTS SHORTWAVE...THOUGH SOLIDLY REMAINING IN NORTHWEST
FLOW ALOFT. AS THE HEIGHTS RISE...THE INVERTED TROUGH OVER SOUTHWEST
MINNESOTA WEAKENS AND PUSHES EAST TOWARDS THE MISSISSIPPI RIVER BY
00Z. LOW LEVEL CONVERGENCE ON THIS TROUGH IN CONJUNCTION WITH
DAYTIME HEATING COULD BE ENOUGH TO PRODUCE A FEW SHOWERS...THOUGH
CONFIDENCE IS PRETTY LOW GIVEN THAT CLOUD COVER MAY PERSIST THROUGH
MUCH OF THE DAY. PLUS...AN EASTERLY FLOW IS PROGGED TO DEVELOP OVER
WISCONSIN AHEAD OF HIGH PRESSURE DROPPING DOWN INTO LAKE SUPERIOR.
THIS EASTERLY FLOW WILL DRIVE DRY AIR INTO THE AREA. MOST MODELS
ARE EITHER DRY OR CLOSE TO IT WITH QPF FIELDS. THEREFORE...HAVE
REDUCED PRECIPITATION CHANCES BY 10 PERCENT AND SHIFTED THE MAX AREA
WESTWARD CLOSER TO THE INVERTED TROUGH. ANY PRECIP WILL END BY 00Z
MONDAY AS THE SURFACE RIDGE BUILDS INTO THE AREA. TEMPERATURES ARE A
LITTLE TRICKY FOR SUNDAY NIGHT AS MODELS NOW SUGGEST SOME CLOUDS
UP AROUND THE DULUTH AREA DROPPING SOUTH WITH THE SURFACE RIDGE. AS
SUCH...FOR NOW LEANED A LITTLE CLOSER TO A MODEL CONSENSUS...SAME
TOO FOR HIGHS ON SUNDAY. CERTAINLY IF WE CLEAR OUT MORE THAN
EXPECTED...FROST/FREEZE CONDITIONS MAY BECOME A WORRY FOR SUNDAY
NIGHT.
MONDAY AND MONDAY NIGHT...THE FORECAST AREA IS EXPECTED TO BE STUCK
BETWEEN STRONG RIDGING IN THE WESTERN U.S. AND DEEP TROUGHING OVER
THE EASTERN U.S.. THE POSITION FAVORS HIGH PRESSURE AT THE
SURFACE...WHICH HOLDS TRUE FOR THE DAY MONDAY. THERE ARE SUGGESTIONS
OF A SLIGHT EASTWARD PUSH OF THE UPPER RIDGE MONDAY NIGHT...WHICH IN
TURN CAUSES A WARM ADVECTION SURGE INTO THE FORECAST AREA. 850MB
TEMPS CLIMB FROM 2-4C AT 00Z TUESDAY TO 6-10C AT 12Z TUESDAY. THE
21.00Z GFS/NAM DEVELOP QPF WITH THIS SURGE OF WARM ADVECTION OVER
NORTHERN AND EASTERN WISCONSIN...POSSIBLY CLIPPING TAYLOR AND ADAMS
COUNTIES. FOR NOW HAVE DECIDED TO KEEP IT DRY IN AGREEMENT WITH THE
ECMWF AND PREVIOUS FORECASTS...THINKING TOO THAT THERE IS NOT MUCH
MOISTURE TO WORK WITH AFTER BEING UNDER THE SURFACE HIGH PRESSURE
RIDGE. SOMETHING TO WATCH...THOUGH. WITH MAINLY SUNNY SKIES ON
MONDAY AND THE WARMING 850MB TEMPS...DEEP MIXING SHOULD OCCUR WITH
HIGHS TOPPING OUT IN THE UPPER 50S/LOW 60S. INCREASING SOUTHWEST
FLOW AHEAD OF A SURFACE TROUGH DROPPING DOWN INTO NORTHERN WISCONSIN
MONDAY NIGHT AND THE WARMER 850MB TEMPS COMING IN SHOULD HELP TO
PRODUCE A WARMER NIGHT.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
342 AM CDT SAT APR 21 2012
BETTER AGREEMENT EXISTS WITH THE 21.00Z ECMWF/GFS/CANADIAN AND GFS
ENSEMBLES TODAY THAN SEEN YESTERDAY. THE WESTERN RIDGE AND EASTERN
TROUGH PATTERN SEEN RECENTLY LOOKS TO CONTINUE THROUGH MUCH OF THE
LONG TERM FORECAST...THOUGH TOWARDS FRIDAY SOME FAIRLY DEEP
TROUGHING DEVELOPS ALONG THE WEST COAST OF THE U.S. TO HELP PUSH
THAT WESTERN RIDGE EASTWARD. WE GET A BRIEF TASTE OF THE WARM AIR
OUT OF THE UPPER RIDGE TUESDAY AND TUESDAY NIGHT...AHEAD OF A LOW
PRESSURE AREA DEEPENING OVER THE DAKOTAS AND SLIDING DOWN INTO IOWA.
WARM ADVECTION AHEAD OF THIS LOW SHOULD PRODUCE SOME SHOWERS AND
POSSIBLY THUNDERSTORMS TUESDAY NIGHT AND WEDNESDAY. LOCATIONS WEST
OF THE MISSISSIPPI RIVER SEEM MOST FAVORABLE RIGHT NOW FOR
PRECIPITATION. HIGH PRESSURE THEN DROPS IN FROM CANADA FOR WEDNESDAY
NIGHT THROUGH FRIDAY NIGHT...WITH MAYBE A BRIEF DRY COLD FRONT
MOVING THROUGH BETWEEN THEN ON THURSDAY NIGHT. THEREFORE...WHEN IT
COMES TO TEMPERATURES...WARMEST READINGS ARE EXPECTED ON TUESDAY AND
WEDNESDAY. MAY HAVE TO DEAL WITH FROST/FREEZE CONDITIONS THURSDAY
NIGHT OR FRIDAY NIGHT OVER CENTRAL WISCONSIN. SOMETHING TO WATCH.
&&
.AVIATION...
1100 PM CDT FRI APR 20 2012
HIGH CLOUDS WILL BE ON THE INCREASE OVERNIGHT...AHEAD OF AN UPPER
LEVEL SHORTWAVE TROUGH DROPPING OVER THE NORTHERN PLAINS. THE CLOUDS
WILL CONTINUE TO INCREASE AND LOWER ON SAT...ALTHOUGH EXPECTATIONS
ARE THAT VFR CONDITIONS WILL PERSIST THROUGH MUCH OF THE AFTERNOON.
THAT SAID...THE TRACK OF THE SFC LOW IS TO THE WEST...AND CLOSER TO
KRST. THINK MVFR CIGS WILL MOVE IN FOR SAT NIGHT...AS BUFKIT
SOUNDINGS AND RH FIELDS ARE SATURATED TO THE SFC. ALONG WITH THIS
LOWERING OF THE CLOUD DECK WILL COME AREAS OF -SHRA. LATEST TRACK
VIA THE GFS40/ECMWF SUGGEST THE BEST PCPN CHANCES WILL BE ACROSS
MN/IA...MOSTLY FROM THE MISSISSIPPI RIVER WESTWARD. THE 00Z NAM12 IS
SIMILAR. WILL CONTINUE PCPN MENTION AT KRST/KLSE...WITH SOME
REDUCTION IN VSBY AFTER 00Z.
ANOTHER CONCERN FOR TONIGHT IS THE POSSIBILITY OF FOG. DECENT SETUP
WITH SOAKING RAINS THE PREVIOUS DAY...AND CLEAR SKIES/LIGHT WINDS
OVERNIGHT. HOWEVER...BUFKIT SOUNDINGS POINT TO AN INCREASE IN WINDS
JUST OFF THE SFC TOWARD 12Z AS AN AREA OF HIGH PRESSURE SLIPS TO THE
EAST. IN ADDITION...THERE IS THE INCREASE IN HIGH CLOUDS FROM THE
WEST. AT THIS TIME...DON/T FEEL THE POTENTIAL FOR BR IS HIGH ENOUGH
TO INCLUDE IN THE TAFS. KLSE WOULD HAVE THE HIGHER THREAT...AND OBS
AND CONDITIONS WILL HAVE TO BE MONITORED THROUGH THE NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
342 AM CDT SAT APR 21 2012
WI...FREEZE WARNING UNTIL 8 AM CDT THIS MORNING FOR WIZ017-029-034-
042>044-053-055.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MIAMI FL
144 AM EDT MON APR 23 2012
.AVIATION...
WESTERLY TO NORTHWESTERLY FLOW IN THE 10 TO 15 KNOT RANGE WITH
GUSTS TO NEAR 24 KNOTS POSSIBLE WILL CONTINUE ACROSS THE REGION
THROUGH MOST THE FORECAST PERIOD. VFR CONDITIONS EXPECTED TO
PREVAIL THROUGH FORECAST PERIOD WITH LITTLE CHANCE OF PRECIP
EXCEPT FOR TERMINAL KAPF WHERE A FEW LIGHT SHOWERS MAY COME OFF
ADJACENT GULF WATERS FROM TIME TO TIME.
60
&&
.PREV DISCUSSION... /ISSUED 1038 PM EDT SUN APR 22 2012/
UPDATE...WINDS OVER LAKE OKEECHOBEE CONTINUE AROUND 20 KT WITH
GUSTS TO AROUND 25 KT...SO EXTENDED THE SCA FOR THE LAKE UNTIL 6
AM MON. OTHERWISE, NO CHANGES TO THE FORECAST ARE NEEDED THIS
EVENING. HIGH PRESSURE WILL CONTINUE TO BUILD INTO FLORIDA FROM
THE NORTHWEST, RESULTING IN RATHER COOL AND DRY CONDITIONS OVER
THE NEXT FEW DAYS. /GREGORIA
PREV DISCUSSION... /ISSUED 734 PM EDT SUN APR 22 2012/
AVIATION...
REMNANT PRECIPITATION ASSOCIATED WITH THE DEPARTED UPPER LEVEL
SYSTEM IS ALL BUT GONE FROM THE SOUTH FLORIDA AREA. ONLY A FEW
SPRINKLES REMAIN AROUND KPBI BUT SHOULD MOVE ON QUICKLY. THE ONLY
FACTOR THROUGH THIS TAF PERIOD WILL BE THE GUSTY WESTERLY GRADIENT
WINDS IN THE WAKE OF THIS SYSTEM. WINDS SHOULD REMAIN GUSTY
THROUGH THE OVERNIGHT HOURS AT ALL SITES.
PREV DISCUSSION... /ISSUED 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 81 57 74 52 / 0 0 0 0
FORT LAUDERDALE 83 59 76 58 / 0 0 0 0
MIAMI 82 59 76 59 / 0 0 0 0
NAPLES 81 57 73 53 / 0 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK UNTIL 11 AM EDT THIS 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 EARLY THIS MORNING FOR
BISCAYNE BAY-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.
&&
$$
DISCUSSION/MARINE/FIRE...47/RGH
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1152 PM CDT SUN APR 22 2012
.UPDATE...
ISSUED AT 1152 PM CDT SUN APR 22 2012
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 06Z TAF ISSUANCE.
UPDATE ISSUED AT 1020 PM CDT SUN APR 22 2012
UPDATED FORECAST TO LESSEN THE MENTION OF FROST FROM /AREAS OF/ TO
/PATCHY/...AND ACROSS A SMALLER GEOGRAPHIC AREA. A NORTH BREEZE
IS EXPECTED TO KEEP TEMPERATURES A FEW DEGREES HIGHER THAN
ORIGINALLY THOUGHT OVERNIGHT...THUS LESSENING THE POTENTIAL FOR
SIGNIFICANT FROST FORMATION. PATCHY FROST IS STILL POSSIBLE
TOWARDS DAYBREAK...MAINLY IN LOCATIONS OF SOUTHERN ILLINOIS...
SOUTHEAST MISSOURI...AND FAR WESTERN KENTUCKY THAT ARE SHELTERED
FROM THE WIND.
&&
.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 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1152 PM CDT SUN APR 22 2012
SKIES CLEARING OUT NICELY LATE THIS EVENING. COULD STILL SEE A FEW
CLOUDS AROUND 7KFT OR SOME CIRRUS IN THE EAST OVERNIGHT...BUT
OTHERWISE IT WILL BE CLEAR. NORTH WINDS SHOULD SETTLE TO JUST UNDER
10KTS THROUGHOUT THE AREA OVERNIGHT.
DEEP MIXING IS EXPECTED TO DEVELOP MONDAY...WITH GUSTY NORTH WINDS
EXPECTED TO DESCEND AROUND 15Z. STRONGER GUSTS TO AROUND 25KTS
WILL BE POSSIBLE FROM 18Z TIL SUNSET. CEILINGS ARE LIKELY TO
DEVELOP IN THE 5-7KFT LAYER AGAIN IN THE MID TO LATE AFTERNOON
MONDAY. THERE MAY BE ENOUGH OF AN UNSTABLE LAYER TO SUPPORT SOME
LIGHT SHOWERS IN THE EARLY EVENING AT KEVV AND KOWB...SO DECIDED
TO INSERT A VFR SHOWER AT EACH SITE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...SMITH
LONG TERM....CTN
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
156 AM EDT MON APR 23 2012
.SYNOPSIS...
LOW PRESSURE CENTERED JUST EAST OF NORFOLK VIRGINIA THIS EVENING
GRADUALLY INTENSIFY AS IT PUSHES TO THE NORTH THEN NORTHWEST
OVERNIGHT AND MONDAY...REACHING THE FINGER LAKES REGION OF NEW
YORK STATE LATE MONDAY. COLDER AIR BEING PULLED SOUTH INTO
WESTERN AND CENTRAL PENNSYLVANIA WILL CHANGE THE RAIN OVER TO
HEAVY WET SNOW ACROSS THE NORTHWEST HALF OF THE STATE DURING THE
OVERNIGHT HOURS. THE HEAVIEST SNOW IS EXPECTED ON THE HIGHER
ELEVATIONS OF NORTH CENTRAL AND NORTHWESTERN PENNSYLVANIA...AND
THE LAUREL HIGHLANDS. HEAVY WET ACCUMULATIONS OF SNOW WILL PRODUCE
WIDESPREAD TREE DAMAGE AND LEAD TO POWER OUTAGES. IMPROVING...BUT
STILL UNSETTLED CONDITIONS WILL FOLLOW FOR TUESDAY AND WEDNESDAY
AS THE COLDEST AIR RETREATS NORTHWARD AND A FAST WESTERLY FLOW
ALOFT DEVELOPS.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
EVENT QPF WILL BE LESS DUE TO MORE PROGRESSIVE EVOLUTION OF
NEGATIVE TILT CUTOFF...AND SFC LOW TRACK TO THE CATSKILLS BY 18Z MON.
COLD CONVEYOR BELT SNOWS NOT AS IMPRESSIVE AS A RESULT...AND HAVE
BEGUN THE PROCESS OF CUTTING BACK AMOUNTS OVER THE LAURELS... WEST
CENTRAL MOUNTAINS AND NORTHWEST MOUNTAINS. LOWER END AMOUNTS
REMAIN THE SAME FOR NOW...BUT WILL WATCH EVOLUTION OVERNIGHT AND
BE PREPARED FOR MORE CHANGES IN THE PRE DAWN HOURS.
DUAL POL CORRELATION COEFFICIENT PRODUCT NICELY INDICATES THAT THE
PRECIP HAS CHANGED OVER TO WET SNOW AT THE BEAM HEIGHT OF
2500-3000 MSL JUST TO THE EAST OF THE RDA...WHILE THIS CC PRODUCT
AND SFC OBS INDICATES THAT THE CHANGEOVER HAS REACHED THE GROUND
ACROSS THE NW MTNS. KDUJ AND KBFD CHANGED TO SNOW BETWEEN 00Z AND
01Z...WHILE KFIG AND KJST JUST WENT OVER TO ALL SNOW WITHIN THE PAST
30 MINUTES. SOME WET SNOW FLAKES HAVE BECOME MIXED IN AROUND THE
HAPPY VALLEY AREA...AND A CHANGOVER TO HEAVY WET SNOW SHOULD OCCUR
FROM KAOO TO KUNV BETWEEN 03Z-05Z BASED ON THE 01Z RUC FCST OF MEAN
925-850 MB WET BULB TEMPS DIPPING SLIGHTLY TO JUST -0.5 TO -1C.
MIXED PHASE PRECIP IS NOTED AT ELEVATIONS AS LOW AS 4500 FT MSL TO
THE EAST THROUGH SSE /AT FURTHER DISTANCES AWAY FROM THE RADAR
SITE/...HIGHLIGHTING THE STRONG EAST TO WEST MID LEVEL TEMP GRADIENT
FROM THE CENTRAL MTNS TO THE SUSQ VALLEY.
THE BACK /SWRN EDGE/ EDGE OF THIS CURRENT PRECIP SHIELD WILL
LIKELY EXPAND TO THE SW...AND PIVOT SLOWLY WWD ACROSS THE
COMMONWEALTH OVERNIGHT AND TUESDAY MORNING WITH PRECIP RATES BEING
MAINTAINED OR EVEN INCREASING ACROSS THE CENTRAL MTNS AND
ALLEGHENY PLATEAU...LEADING TO HEAVY WET SNOW WITHIN A FEW
QUASI-SNTRY BANDS OF MDT TO STG FRONTOGENESIS.
NO APPRECIABLE CHANGE WAS MADE TO THE GRIDDED FCST DATABASE WITH
RESPECT TO THE TIMING OF THE RAIN TO SNOW CHANGEOVER...AND
RESULTANT SNOW ACCUMS BY 12Z MONDAY. WILL BE KEEPING A WATCHFUL
EYE THOUGH ON THE HIGH TERRAIN OF SULLIVAN COUNTY /NE OF
KIPT/...SINCE THEY/RE CURRENTLY ONLY IN THE MID 30S WITH WEAK LLVL
COLD ADVECTION CONTINUING. HOWEVER...WARMER AIR SURGING IN ALOFT
FROM THE SSE SHOULD LIMIT ANY CHANGEOVER FOR MUCH OF THE NIGHT TO
JUST A MIX OF WET SNOW AND SLEET AT BEST.
THE RAINFALL IN THE EAST HAS BEEN A STEADY/MODERATELY HEAVY COLD
RAIN FALLING AT A RATE OF GENERALLY 102 TENTHS OF AN INCH PER
HOUR. THE VERY DRY ANTECEDENT CONDITIONS AND EARLY GREEN-UP WILL
ABLE TO EASILY HANDLE THIS RATE...AND TOTAL FCST RAINFALL OF 1-2
INCHES...WITH MINOR TO AT MOST MODERATE RISES ON SMALLER STREAMS
OVER...AND TO THE EAST OF THE SUSQ MAINSTEM.
THE RAIN WILL BE TAPERING OFF IN THE EAST BETWEEN 05Z AND 09Z
MONDAY.
LOW TEMPS OVERNIGHT WILL RANGE FROM THE LOWER 40S IN THE SE
ZONES...TO AROUND 30 ACROSS THE HIGHEST TERRAIN OF THE WEST.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM TUESDAY/...
PERIODS OF MDT TO HEAVY WET SNOW WILL PERSIST ACROSS THE NW MTNS
AND LAUREL HIGHLANDS FOR MUCH OF MONDAY AS THE UPPER LOW TURNS NE
AND LIFTS ACROSS CENTRAL PENN. A MIX OF WET SNOW...AND RAIN IS
STILL EXPECTED IN THE LOWER ELEVS OF THE RIDGE AND VALLEY REGION.
THE SFC/BLYR TEMPS ARE THE TRICK TO THIS FCST - WITH THE SNOW
ACCUMS ALMOST ENTIRELY ELEV /AND SNOWFALL RATE/ DEPENDENT. THE
TIMES OF HEAVY SNOW WILL BE TOUGH TO PINPOINT...AND WILL KEEP IT
BROAD BRUSHED. WILL MAINTAIN THE GOING FCST AS THERE IS NO REASON
TO CHANGE. TEMPS WILL HOVER IN THE LOWER AND MID 30S IN THE
CENTRAL MTS...BUT 30-33 IN THE WRN AND NRN HIGHLANDS. THE ODDITY
OF THIS FCST WILL BE THE RELATIVELY WARM AND DRY AIR THAT GETS
INTO SULLIVAN AND TIOGA COS. ONLY MINOR TWEAKS TO THE SNOW ACCUMS
ARE EXPECTED.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
DEEP TROUGH AND POWERFUL UPPER LOW WILL BE CENTERED OVER THE PA/NY
BORDER MON NIGHT...WITH 500 MB HEIGHTS BELOW 530 FORECAST SOLIDLY BY
THE ECMWF GFS AND NAM. LOW GRADUALLY LIFTS STRAIGHT NORTHWARD AS IT
DEEPENS A BIT FURTHER THROUGH 12Z TUE...THEN BEGINS TO FILL IN ON
TUE UPON ARRIVING IN S CANADA. 987MB SFC LOW ALSO PUSHING NORTHWARD
INTO S NY STATE MON NIGHT WILL FOCUS PRECIP ON ITS COLD SIDE AS 50+
KT COLD CONVEYOR BELT WRAPS AROUND FROM THE NW...WITH LITTLE PRECIP
INDICATED FOR EASTERN HALF OF CWA. SO...ONGOING WINTER WEATHER EVENT
ACROSS WESTERN HALF OF CWA WILL CONTINUE TO BE INTENSE HEADING INTO
MON NIGHT...AND GRADUALLY LESSEN ITS GRIP AS NIGHT PROGRESSES AS
COLD CONVEYOR BELT LIFTS NORTHWARD...RESULTING IN JUST A LIGHTER
SNOW BY 12Z TUE - WHICH WILL LINGER IN THE NORTHERN MTNS POSS INTO
WED.
THE WINTER STORM WARNING/ADVISORY DURATION THROUGH MON NIGHT LOOKS
JUSTIFIED BASED ON QPF FORECASTS/IMPACTS. STORM TOTAL SNOWFALL
OVER MUCH OF THE ALLEGHENIES SHOULD EASILY EXCEED 8 INCHES...WITH
SOME 12-16 INCH AMOUNTS PAINTED IN. SNOWFALL TAPERS OFF FAIRLY
SHARPLY HEADING EAST ACROSS C MTNS...WITH A STRIPE OF 2 TO 5
INCHES IN THE CENTRAL MOUNTAINS - ACCUMULATING MAINLY ON THE
GRASSY SURFACES WITH A LESSER IMPACT ON ROADS. LITTLE ACCUM
EXPECTED IN SUSQ VALLEY...THOUGH SOME SNOW COULD MIX IN ON
OCCASION WITH THE PREDOMINANT PRECIP TYPE OF RAIN - EVEN AS IT
TAPERS TO SHOWERS MON NIGHT INTO TUES.
THE DEEP UPPER TROF LIFTS TO THE NE WED-WED NIGHT...BUT NORTHWEST
FLOW PERSISTS AS ADDITIONAL WEAKER DISTURBANCES ROTATE ACROSS THE
REGION THROUGH THE REMAINDER OF THE WEEK...KEEPING WEATHER SOMEWHAT
UNSETTLED INTO FRI BEFORE A DRIER REGIME MOVES IN. TEMPS LOOK TO BE
BELOW NORMAL FOR MUCH OF THE WEEK.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
STRENGTHENING LOW PRES PASSING JUST EAST OF PA OVERNIGHT WILL
BRING SNOW WITH LOW CIGS/VSBYS AND GUSTY NORTH WINDS ACROSS THE
WESTERN MTNS INTO MONDAY NIGHT. AOO AND UNV ARE ALSO GETTING SOME
SNOW MIXED WITH THE RAIN.
A DRY SLOT IS WORKING INTO SE PA AT THE CURRENT TIME...CAUSING
THE RAIN TO TAPER OFF TO SPOTTY LIGHT OVR THE LWR SUSQ VALLEY.
HOWEVER...MVFR CIGS AND SCT -SHRA SHOULD PERSIST THRU THE NIGHT
AND MONDAY AT IPT/MDT/LNS.
AS THE STORM SYSTEM PASSES JUST TO OUR EAST...EXPECT GUSTY NW
WINDS TO BUFFET THE AREA ON MONDAY...ESP OVR THE LAUREL HIGHLANDS
WHERE BUFKIT SOUNDINGS SUPPORT GUSTS TO NR 30KTS AT JST. THE
COLD...MOIST...UPSLOPING FLOW WILL PRODUCE SNOW AND LOW VSBYS/CIGS
AT BFD/JST. SOMEWHAT BETTER CONDS LIKELY AT AOO/UNV...BUT OCNL
SNOW COULD PRODUCE IFR VSBYS AT TIMES. MOST FAVORABLE CONDS WILL
BE ACROSS THE SUSQ VALLEY...WHERE DRYING...DOWNSLOPING FLOW RESULT
IN ONLY SCT -SHRA.
OUTLOOK...
TUE...LOW CIGS/VSBYS POSS AT BFD IN OCNL SHSN.
WED...NO SIG WX EXPECTED.
THU...RAIN/LOW CIGS POSS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON EDT TUESDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041.
WINTER WEATHER ADVISORY UNTIL 6 AM EDT TUESDAY FOR PAZ019-025-
026-034-035-045.
&&
$$
SYNOPSIS...DANGELO/DEVOIR/LAMBERT
NEAR TERM...DANGELO/DEVOIR/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1258 AM EDT MON APR 23 2012
.SYNOPSIS...
LOW PRESSURE CENTERED JUST EAST OF NORFOLK VIRGINIA THIS EVENING
GRADUALLY INTENSIFY AS IT PUSHES TO THE NORTH THEN NORTHWEST
OVERNIGHT AND MONDAY...REACHING THE FINGER LAKES REGION OF NEW
YORK STATE LATE MONDAY. COLDER AIR BEING PULLED SOUTH INTO
WESTERN AND CENTRAL PENNSYLVANIA WILL CHANGE THE RAIN OVER TO
HEAVY WET SNOW ACROSS THE NORTHWEST HALF OF THE STATE DURING THE
OVERNIGHT HOURS. THE HEAVIEST SNOW IS EXPECTED ON THE HIGHER
ELEVATIONS OF NORTH CENTRAL AND NORTHWESTERN PENNSYLVANIA...AND
THE LAUREL HIGHLANDS. HEAVY WET ACCUMULATIONS OF SNOW WILL PRODUCE
WIDESPREAD TREE DAMAGE AND LEAD TO POWER OUTAGES. IMPROVING...BUT
STILL UNSETTLED CONDITIONS WILL FOLLOW FOR TUESDAY AND WEDNESDAY
AS THE COLDEST AIR RETREATS NORTHWARD AND A FAST WESTERLY FLOW
ALOFT DEVELOPS.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
EVENT QPF WILL BE LESS DUE TO MORE PROGRESSIVE EVOLUTION OF
NEGATIVE TILT CUTOFF...AND SFC LOW TRACK TO THE CATSKILLS BY 18Z MON.
COLD CONVEYOR BELT SNOWS NOT AS IMPRESSIVE AS A RESULT...AND HAVE
BEGUN THE PROCESS OF CUTTING BACK AMOUNTS OVER THE LAURELS... WEST
CENTRAL MOUNTAINS AND NORTHWEST MOUNTAINS. LOWER END AMOUNTS
REMAIN THE SAME FOR NOW...BUT WILL WATCH EVOLUTION OVERNIGHT AND
BE PREPARED FOR MORE CHANGES IN THE PRE DAWN HOURS.
DUAL POL CORRELATION COEFFICIENT PRODUCT NICELY INDICATES THAT THE
PRECIP HAS CHANGED OVER TO WET SNOW AT THE BEAM HEIGHT OF
2500-3000 MSL JUST TO THE EAST OF THE RDA...WHILE THIS CC PRODUCT
AND SFC OBS INDICATES THAT THE CHANGEOVER HAS REACHED THE GROUND
ACROSS THE NW MTNS. KDUJ AND KBFD CHANGED TO SNOW BETWEEN 00Z AND
01Z...WHILE KFIG AND KJST JUST WENT OVER TO ALL SNOW WITHIN THE PAST
30 MINUTES. SOME WET SNOW FLAKES HAVE BECOME MIXED IN AROUND THE
HAPPY VALLEY AREA...AND A CHANGOVER TO HEAVY WET SNOW SHOULD OCCUR
FROM KAOO TO KUNV BETWEEN 03Z-05Z BASED ON THE 01Z RUC FCST OF MEAN
925-850 MB WET BULB TEMPS DIPPING SLIGHTLY TO JUST -0.5 TO -1C.
MIXED PHASE PRECIP IS NOTED AT ELEVATIONS AS LOW AS 4500 FT MSL TO
THE EAST THROUGH SSE /AT FURTHER DISTANCES AWAY FROM THE RADAR
SITE/...HIGHLIGHTING THE STRONG EAST TO WEST MID LEVEL TEMP GRADIENT
FROM THE CENTRAL MTNS TO THE SUSQ VALLEY.
THE BACK /SWRN EDGE/ EDGE OF THIS CURRENT PRECIP SHIELD WILL
LIKELY EXPAND TO THE SW...AND PIVOT SLOWLY WWD ACROSS THE
COMMONWEALTH OVERNIGHT AND TUESDAY MORNING WITH PRECIP RATES BEING
MAINTAINED OR EVEN INCREASING ACROSS THE CENTRAL MTNS AND
ALLEGHENY PLATEAU...LEADING TO HEAVY WET SNOW WITHIN A FEW
QUASI-SNTRY BANDS OF MDT TO STG FRONTOGENESIS.
NO APPRECIABLE CHANGE WAS MADE TO THE GRIDDED FCST DATABASE WITH
RESPECT TO THE TIMING OF THE RAIN TO SNOW CHANGEOVER...AND
RESULTANT SNOW ACCUMS BY 12Z MONDAY. WILL BE KEEPING A WATCHFUL
EYE THOUGH ON THE HIGH TERRAIN OF SULLIVAN COUNTY /NE OF
KIPT/...SINCE THEY/RE CURRENTLY ONLY IN THE MID 30S WITH WEAK LLVL
COLD ADVECTION CONTINUING. HOWEVER...WARMER AIR SURGING IN ALOFT
FROM THE SSE SHOULD LIMIT ANY CHANGEOVER FOR MUCH OF THE NIGHT TO
JUST A MIX OF WET SNOW AND SLEET AT BEST.
THE RAINFALL IN THE EAST HAS BEEN A STEADY/MODERATELY HEAVY COLD
RAIN FALLING AT A RATE OF GENERALLY 102 TENTHS OF AN INCH PER
HOUR. THE VERY DRY ANTECEDENT CONDITIONS AND EARLY GREEN-UP WILL
ABLE TO EASILY HANDLE THIS RATE...AND TOTAL FCST RAINFALL OF 1-2
INCHES...WITH MINOR TO AT MOST MODERATE RISES ON SMALLER STREAMS
OVER...AND TO THE EAST OF THE SUSQ MAINSTEM.
THE RAIN WILL BE TAPERING OFF IN THE EAST BETWEEN 05Z AND 09Z
MONDAY.
LOW TEMPS OVERNIGHT WILL RANGE FROM THE LOWER 40S IN THE SE
ZONES...TO AROUND 30 ACROSS THE HIGHEST TERRAIN OF THE WEST.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM TUESDAY/...
PERIODS OF MDT TO HEAVY WET SNOW WILL PERSIST ACROSS THE NW MTNS
AND LAUREL HIGHLANDS FOR MUCH OF MONDAY AS THE UPPER LOW TURNS NE
AND LIFTS ACROSS CENTRAL PENN. A MIX OF WET SNOW...AND RAIN IS
STILL EXPECTED IN THE LOWER ELEVS OF THE RIDGE AND VALLEY REGION.
THE SFC/BLYR TEMPS ARE THE TRICK TO THIS FCST - WITH THE SNOW
ACCUMS ALMOST ENTIRELY ELEV /AND SNOWFALL RATE/ DEPENDENT. THE
TIMES OF HEAVY SNOW WILL BE TOUGH TO PINPOINT...AND WILL KEEP IT
BROAD BRUSHED. WILL MAINTAIN THE GOING FCST AS THERE IS NO REASON
TO CHANGE. TEMPS WILL HOVER IN THE LOWER AND MID 30S IN THE
CENTRAL MTS...BUT 30-33 IN THE WRN AND NRN HIGHLANDS. THE ODDITY
OF THIS FCST WILL BE THE RELATIVELY WARM AND DRY AIR THAT GETS
INTO SULLIVAN AND TIOGA COS. ONLY MINOR TWEAKS TO THE SNOW ACCUMS
ARE EXPECTED.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
DEEP TROUGH AND POWERFUL UPPER LOW WILL BE CENTERED OVER THE PA/NY
BORDER MON NIGHT...WITH 500 MB HEIGHTS BELOW 530 FORECAST SOLIDLY BY
THE ECMWF GFS AND NAM. LOW GRADUALLY LIFTS STRAIGHT NORTHWARD AS IT
DEEPENS A BIT FURTHER THROUGH 12Z TUE...THEN BEGINS TO FILL IN ON
TUE UPON ARRIVING IN S CANADA. 987MB SFC LOW ALSO PUSHING NORTHWARD
INTO S NY STATE MON NIGHT WILL FOCUS PRECIP ON ITS COLD SIDE AS 50+
KT COLD CONVEYOR BELT WRAPS AROUND FROM THE NW...WITH LITTLE PRECIP
INDICATED FOR EASTERN HALF OF CWA. SO...ONGOING WINTER WEATHER EVENT
ACROSS WESTERN HALF OF CWA WILL CONTINUE TO BE INTENSE HEADING INTO
MON NIGHT...AND GRADUALLY LESSEN ITS GRIP AS NIGHT PROGRESSES AS
COLD CONVEYOR BELT LIFTS NORTHWARD...RESULTING IN JUST A LIGHTER
SNOW BY 12Z TUE - WHICH WILL LINGER IN THE NORTHERN MTNS POSS INTO
WED.
THE WINTER STORM WARNING/ADVISORY DURATION THROUGH MON NIGHT LOOKS
JUSTIFIED BASED ON QPF FORECASTS/IMPACTS. STORM TOTAL SNOWFALL
OVER MUCH OF THE ALLEGHENIES SHOULD EASILY EXCEED 8 INCHES...WITH
SOME 12-16 INCH AMOUNTS PAINTED IN. SNOWFALL TAPERS OFF FAIRLY
SHARPLY HEADING EAST ACROSS C MTNS...WITH A STRIPE OF 2 TO 5
INCHES IN THE CENTRAL MOUNTAINS - ACCUMULATING MAINLY ON THE
GRASSY SURFACES WITH A LESSER IMPACT ON ROADS. LITTLE ACCUM
EXPECTED IN SUSQ VALLEY...THOUGH SOME SNOW COULD MIX IN ON
OCCASION WITH THE PREDOMINANT PRECIP TYPE OF RAIN - EVEN AS IT
TAPERS TO SHOWERS MON NIGHT INTO TUES.
THE DEEP UPPER TROF LIFTS TO THE NE WED-WED NIGHT...BUT NORTHWEST
FLOW PERSISTS AS ADDITIONAL WEAKER DISTURBANCES ROTATE ACROSS THE
REGION THROUGH THE REMAINDER OF THE WEEK...KEEPING WEATHER SOMEWHAT
UNSETTLED INTO FRI BEFORE A DRIER REGIME MOVES IN. TEMPS LOOK TO BE
BELOW NORMAL FOR MUCH OF THE WEEK.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
STRENGTHENING LOW PRES PASSING JUST EAST OF PA OVERNIGHT WILL
BRING SNOW WITH LOW CIGS/VSBYS AND GUSTY NW WINDS ACROSS THE W
MTNS OVERNIGHT AND MONDAY. AOO AND UNV ARE ALSO LIKELY TO BECOME
IFR AS RAIN CHANGES TO ALL SNOW AFTER MIDNIGHT. A DRY SLOT IS
EXPECTED TO WORK INTO EASTERN PA BTWN 05Z-08Z...CAUSING THE RAIN
TO TAPER OFF OVR THE SUSQ VALLEY. HOWEVER...MVFR CIGS AND SCT
-SHRA SHOULD PERSIST THRU THE NIGHT AT IPT/MDT/LNS.
AS THE STORM SYSTEM PASSES JUST TO OUR EAST...EXPECT GUSTY NW
WINDS TO BUFFET THE AREA ON MONDAY...ESP OVR THE LAUREL HIGHLANDS
WHERE BUFKIT SOUNDINGS SUPPORT GUSTS TO NR 30KTS AT JST. THE
COLD...MOIST...UPSLOPING FLOW WILL PRODUCE SNOW AND LOW VSBYS/CIGS
AT BFD/JST. SOMEWHAT BETTER CONDS LIKELY AT AOO/UNV...BUT OCNL
SNOW COULD PRODUCE IFR VSBYS AT TIMES. MOST FAVORABLE CONDS WILL
BE ACROSS THE SUSQ VALLEY...WHERE DRYING...DOWNSLOPING FLOW RESULT
IN ONLY SCT -SHRA AND MVFR CIGS.
OUTLOOK...
TUE...LOW CIGS/VSBYS POSS AT BFD IN OCNL SHSN.
WED...NO SIG WX EXPECTED.
THU...RAIN/LOW CIGS POSS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON EDT TUESDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041.
WINTER WEATHER ADVISORY UNTIL 6 AM EDT TUESDAY FOR PAZ019-025-
026-034-035-045.
&&
$$
SYNOPSIS...DANGELO/DEVOIR/LAMBERT
NEAR TERM...DANGELO/DEVOIR/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
346 AM CDT MON APR 23 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
346 AM CDT MON APR 23 2012
MAIN FORECAST CONCERNS THIS PACKAGE...WARMING TEMPERATURES TODAY/
TUE...PRECIPITATION CHANCES FROM TUE NIGHT THROUGH WED NIGHT.
06Z SURFACE ANALYSIS HAD A BROAD AREA OF HIGH PRESSURE OVER MUCH
OF THE CENTRAL CONUS...CENTERED OVER EASTERN NEB. WITH THE HIGH
RATHER SPRAWLING WITH WEAK GRADIENTS OVER THE REGION WINDS WERE ON
THE LIGHT SIDE. FOG-PRODUCT IMAGERY INDICATED A COUPLE SMALLER
AREAS OF ALTO-CUMULUS DRIFTING SOUTHEAST ACROSS MN/WI. OTHERWISE
SKIES WERE CLEAR OVER THE UPPER MIDWEST EARLY THIS MORNING WITH
TEMPERATURES NEAR LATE APRIL NORMALS.
23.00Z MODELS HAVE INITIALIZED WITHOUT MAJOR ERRORS AND OFFER QUITE
SIMILAR SOLUTIONS FOR TODAY THRU WED NIGHT. SOME DIFFERENCES WITH
TIMING/AMOUNT OF PRECIP WITH THE NORTHWEST FLOW SYSTEM TO MOVE
ACROSS THE AREA LATER TUE NIGHT THRU WED EVENING...BUT THIS TO BE
EXPECTED WITH THE SHORTWAVE OF INTEREST STILL ON THE WEST SIDE OF
THE RIDGE AXIS. DPROG/DT OF 500MB HGTS AT 23.00Z SHOWED MODEL RUNS
OF 21.00Z AND 22.00Z VERIFIED WELL ACROSS NOAM/EASTERN PAC. MODELS
MARCHING TOWARD A TIGHTER CONSENSUS TODAY THRU WED NIGHT AS ONE
UPPER LOW LIFTS NORTH THRU THE EASTERN CONUS/CAN AND THE NEXT
TROUGHING MOVES ONTO THE WEST COAST. TREND TENDS TO FAVOR SLOWER OF
EARLIER RUNS WITH THE EASTERN NOAM TROUGH AND A COMPROMISE WITH THE
TROUGHING TO MOVE ONTO THE WEST COAST. CHECK OF OBS VS. MODEL DATA
AT 06Z SHOWED MODELS GOOD WITH THE HIGH OVER THE CENTRAL CONUS AND
THE STRONG LOW MOVING UP THE EAST COAST. PER WV IMAGERY ALL LOOKED
VERY REASONABLE WITH THE SHORTWAVE DETAILS ACROSS NOAM/EASTERN PAC.
NO CLEAR MODEL FAVORITE THIS CYCLE. WITH THE TREND TOWARD A
COMPROMISE IN THE EAST/WESTERN TROUGHS...WILL FAVOR A COMPROMISE
WITH THE SHORTWAVE TO TOP THE RIDGE AND IMPACT THE AREA TUE NIGHT
INTO WED NIGHT. OVERALL SHORT-TERM FCST CONFIDENCE AVERAGE TO GOOD
THIS CYCLE.
IN THE SHORT TERM...QUIET WEATHER TODAY THRU TUE AS A PORTION OF THE
SFC RIDGE AXIS REMAINS OVER THE REGION...SANDWICHED BETWEEN THE LOW
LIFTING FROM NJ TO WESTERN QUEBEC AND LOW PRESSURE DEVELOPING IN
THE NORTHERN PLAINS. SFC GRADIENT WINDS WILL REMAIN LIGHT...BUT
MODEL SOUNDINGS INDICATE RATHER DEEP MIXING TODAY UNDER PARTLY
CLOUDY TO SUNNY SKIES AND 850MB TEMPS A COUPLE DEGREES EITHER SIDE
OF 0C. 925-850MB WINDS IN THE 15-20KT RANGE TODAY SO SOME INCREASE
OF WINDS/GUSTINESS EXPECTED FOR THE AFTERNOON. MODELS WITH A RATHER
CONSISTENT SIGNAL FOR SOME MOISTURE AROUND 700MB AND WEAK VERTICAL
MOTION TO SPREAD ACROSS THE AREA TONIGHT THEN LINGER INTO TUE.
EVEN WITH THE HIGH OVER THE REGION...PARTLY TO MOSTLY CLOUDY SKIES
EXPECTED TONIGHT. 925-850MB RIDGE AXIS IS CLOSER/OVER THE AREA
TUE...FOR THE WINDS TO REMAIN LIGHT. TIGHTER MODEL CONSENSUS
BEGINNING TO FOCUS THE RAIN CHANCES TUE NIGHT INTO WED NIGHT.
INCREASE OF MOISTURE/LIFT INTO THE AREA WITH THE HGT FALLS AND LOWER
LEVEL THERMO-DYNAMIC FORCING AHEAD OF THE SHORTWAVE AND NORTHERN
PLAINS LOW ARRIVES LATER TUE NIGHT. REMOVED -SHRA/TSRA CHANCE
FROM TUE EVENING. STRONGEST OF LIFT/DEEPEST OF MOISTURE TRANSLATES
ACROSS THE AREA WED...HOWEVER BULK OF MOISTURE/LIFT IS ABOVE 700MB.
THIS MAY BE WHY MODELS ARE SOMEWHAT INCONSISTENT PUTTING PRECIP ON
THE GROUND AS THIS WAVE AND THE FORCING PASS. DID RAISE SHRA/TSRA
CHANCES ON WED TO AROUND 50 PERCENT FOR NOW. NOT CONVINCED OF TSRA
CENTERED ON WED BUT WITH MODELS SHOWING AT LEAST MOIST ADIABATIC
LAPSE RATES ABOVE 700MB AND AROUND 1000 J/KG OF MU CAPE IN THE
INFLOW AIRMASS...LEFT CHANCES OF TSRA IN GRIDS FOR NOW. IMPROVING
MODEL CONSENSUS HAS THE WAVE/FORCING/LIFT PASSING WED NIGHT WITH
SUBSIDENCE/DRYING OF THE COLUMN SPREADING SOUTHEAST ACROSS THE FCST
AREA LATER IN THE EVENING AND OVERNIGHT. CONTINUED A 20-30 PERCENT
CHANCE OF SHRA OVER THE SOUTHEAST HALF OF THE FCST AREA WED EVENING
AND REMOVED RAIN CHANCES FROM LATER WED NIGHT.
TRENDED TOWARD A BLEND OF THE NUMERICAL GUIDANCE HIGHS/LOWS FOR
TODAY...TONIGHT...TUE NIGHT. TEMPERED THE TUE WARM-UP A BIT WITH
POTENTIAL FOR SOME MID CLOUDS AND STRONGER OF 925-850MB WARMING
REMAINING WEST OF THE AREA. FAVORED COOLER OF GUIDANCE HIGHS WED
WITH PLENTY OF CLOUDS EXPECTED...SCT -SHRA/TSRA POSSIBLE MUCH OF THE
DAY AND THE DRIER SFC-925MB LAYER FOR EVAPORATIVE COOLING IN/AROUND
ANY RAIN. WITH SOME CLEARING/DRYING AND STRONGER SFC-850MB COLD
ADVECTION BY/AFTER MIDNIGHT...FAVORED COOLER OF GUIDANCE LOWS FOR
WED NIGHT.
.LONG TERM...THURSDAY THROUGH SUNDAY
346 AM CDT MON APR 23 2012
AGREEMENT IMPROVING AMONG MEDIUM RANGE MODELS WITH THE 23.00Z RUNS.
UPPER FLOW AMPLIFIES FOR THU WITH STRONG/COLD CAN HIGH PRESSURE
SETTLING INTO THE UPPER MIDWEST FOR THU/THU NIGHT. THU NIGHT LOOKS
QUITE COLD AND MAY YET NEED ANOTHER ROUND OF FROST/FREEZE HEADLINES
FOR MUCH OF THE FCST AREA LATE THU NIGHT/FRI MORNING. NEEDLESS TO
SAY TEMPS TO END THE WEEK...AND THE WEEKEND...TREND BELOW NORMAL.
TROUGHING MOVING THRU THE WESTERN CONUS INTO THE PLAINS BEGINS TO
SEND ENERGY AND MOISTURE TOWARD THE AREA ALREADY LATER THRU NIGHT
AND FRI. PLENTY OF MODEL DETAIL/SHORTWAVE TIMING DIFFERENCES BY THIS
TIME. TREND OF MODELS FRI/SAT IS STRONGER/FURTHER NORTH WITH THE SFC
LOW AND THE LEAD ENERGY WITH THE TROUGH LIFTING INTO THE CENTRAL
PLAINS AND TOWARD THE AREA. MODELS FURTHER NORTH/ STRONGER WITH THE
LOWER LEVEL FORCING/LIFT/MOISTURE TO MOVE ACROSS THE MID/UPPER MS
VALLEY. 20-40 PERCENT SHRA CHANCES FOR MUCH OF FRI INTO SUN...
HIGHEST ACROSS THE SOUTH...LOOK GOOD FOR NOW UNTIL MODEL
TIMING/LATITUDE DETAILS SETTLE DOWN. DID LIMIT TSRA CHANCES FOR MUCH
OF FRI-SAT TO NORTHEAST IA/FAR SOUTHWEST WI CLOSER TO CURRENT
EXPECTED WARM FRONT/LOW TRACK. MODEL CONSENSUS DATA IN FCST GRIDS
FOR THU-SUN APPEARS WELL TRENDED FOR NOW.
&&
.AVIATION...THROUGH 06Z TUESDAY NIGHT
1105 PM CDT SUN APR 22 2012
A WEAK UPPER LEVEL SHORTWAVE TROUGH WILL KEEP A DECK OF 6-8 KFT
CLOUDS ACROSS THE TAF SITES THROUGH 07-08Z...SCATTERING OUT AFTER
THAT. HOWEVER...THE 00Z NAM12/GFS40 AND LATEST RUC13 ALL POINT TO A
SWATH OF SOMEWHAT LOWER SATURATION SLIDING ACROSS WESTERN WI BETWEEN
09-12Z. THIS LOOKS ASSOCIATED WITH SOME 3-6 KFT CEILINGS NEAR THE
TIP OF LAKE SUPERIOR. WILL ADD SOME MENTION OF BKN CIGS IN THIS TIME
FRAME FOR KLSE...BUT WILL KEEP OUT OF KRST FOR NOW. OVERALL
THOUGH...VFR CONDITIONS SHOULD PERSIST INTO MONDAY NIGHT.
WINDS WILL STAY FROM A NORTHERN DIRECTION THROUGH MONDAY. GOOD
MIXING WILL LEAD TO SOME LATE MORNING/AFTERNOON GUSTINESS UPWARDS OF
20+ KTS. WINDS SHOULD DIE OFF VERY QUICKLY MONDAY EVENING AS THE
NOCTURNAL INVERSION SETS UP AND HIGH PRESSURE INFLUENCES THE REGION.
LOOK FOR A RETURN OF SOME HIGH LEVEL CLOUDS BEFORE MIDNIGHT AS MORE
MOISTURE SPILLS ACROSS THE UPPER LEVEL RIDGE AND ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY.
&&
.FIRE WEATHER...THIS AFTERNOON
346 AM CDT MON APR 23 2012
LITTLE HAS CHANGED WITH CRITICAL FIRE WEATHER POTENTIAL ACROSS
CENTRAL...NORTH CENTRAL...AND PORTIONS OF SOUTHWEST WI THIS
AFTERNOON. MODEL SOUNDINGS CONTINUE TO INDICATED DEEP MIXING THIS
AFTERNOON WITH DEW POINTS ALONG/EAST OF ROUGHLY A KOVS-BLACK RIVER
FALLS LINE LOWERING INTO THE MID/UPPER 20S AND MINIMUM RELATIVE
HUMIDITY VALUES FALLING INTO THE 20 TO 25 PERCENT RANGE. THE DEEP
MIXING WILL ALSO ALLOW FOR 15-25 MPH WINDS ALOFT TO MIX TO THE
SFC...MAKING FOR GUSTY NORTHWEST TO NORTH WINDS DURING THE PEAK
HEATING PART OF THE DAY. THE WINDS WILL QUICKLY DIMINISH THIS
EVENING AS SURFACE HEATING DECREASES. ALONG/WEST OF THE MISSISSIPPI
RIVER...LIGHTER WINDS ARE EXPECTED ALONG WITH MINIMUM RELATIVE
HUMIDITY VALUES IN THE 28 TO 34 PERCENT RANGE...BUT CONDITIONS IN
THESE AREAS THIS AFTERNOON WILL HAVE TO BE WATCHED AS WELL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
346 AM CDT MON APR 23 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM.....RRS
LONG TERM......RRS
AVIATION.......RIECK
FIRE WEATHER...RRS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1200 AM CDT MON APR 23 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.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...A DECREASING 7000-9000 FEET MID LEVEL CIG WILL
CONTINUE TO DRIFT OVER PART OF THE REGION OVERNIGHT...OTHERWISE
VFR CONDITIONS EXPECTED THROUGH MONDAY. A DEEPENING LOW PRESSURE
SYSTEM WORKING OVER THE EASTERN SEABOARD OF THE U.S. WILL GENERATE
GUSTY NORTH WINDS OVER THE STATE ON MONDAY.
TDH
&&
.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.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 PM CDT SUN APR 22 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
300 PM CDT SUN APR 22 2012
MAIN FORECAST CONCERN IS ON TEMPERATURES IN THE NEAR TERM...THEN
PRECIPITATION CHANCES FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.
18Z SURFACE ANALYSIS SHOWS A WEAK TROUGH EXTENDING NORTHWARD THROUGH
CENTRAL IOWA INTO CENTRAL MINNESOTA. CLOUDS CONTINUED TO BE FOUND IN
THIS AREA...BUT A DRIER EASTERLY FLOW HAS KEPT MUCH OF THE FORECAST
AREA UNDER SUNNY TO PARTLY CLOUDY SKIES...AS SURFACE DEW POINTS WERE
IN THE LOW TO MID 20S OVER MUCH OF WISCONSIN.
IN THE NEAR TERM...HIGH PRESSURE WILL DROP INTO THE AREA TONIGHT.
WINDS WILL BE LIGHT AND SOME CONCERN FOR FREEZING TEMPERATURES.
HOWEVER...22.12Z NAM AND GFS IS SHOWING SOME 850MB-700MB MOISTURE
SWINGING ACROSS THE AREA OVERNIGHT AND SHOULD KEEP TEMPERATURES FROM
BOTTOMING OUT. WITH THESE CLOUDS...DID GO SLIGHTLY ABOVE GUIDANCE
NUMBERS.
UPPER RIDGE WILL CONTINUE TO BUILD ACROSS THE AREA MONDAY AND
TUESDAY AS SURFACE RIDGE MOVES EASTWARD. AS WINDS TURN SOUTH ON
BACKSIDE OF THE HIGH...WARM ADVECTION WILL BEGIN TO SPREAD INTO THE
AREA FROM THE WEST. 850MB TEMPERATURES OF AROUND +2 TO +3
CELSIUS MONDAY AFTERNOON CLIMBS INTO THE TEENS ACROSS SOUTHEAST
MINNESOTA AND NORTHEAST IOWA BY TUESDAY AFTERNOON...AND THUS
EXPECT HIGHS MONDAY IN THE UPPER 50S TO LOWER 60S...RISING INTO
THE 60S TO LOWER 70S BY TUESDAY. IN ADDITION...MONDAY AFTERNOON
BUFKIT SOUNDINGS SHOW MIXING TO BETWEEN 800MB-750MB TAPPING INTO
TO SOME HIGHER WINDS ALOFT...ESPECIALLY OVER THE EASTERN SECTIONS
OF THE FORECAST AREA. AND WITH THIS MIXING LOWER DEW POINTS ARE
EXPECTED THAN WHAT THE MODELS ARE GIVING RESULTING IN SOME FIRE
WEATHER CONCERNS (SEE FIRE WEATHER SECTION BELOW FOR THE DETAILS)
NEXT SHORTWAVE THEN FLATTENS THE RIDGE TUESDAY NIGHT INTO WEDNESDAY.
MOISTURE NOT OVERLY IMPRESSIVE...BUT PRECIPITABLE WATER DO INCREASE
TO BETWEEN THREE QUARTERS OF AN INCH TO ONE INCH BY WEDNESDAY.
MODELS STILL STRUGGLING A BIT ON PLACEMENT AND TIMING AND THUS
CONTINUED THE MID RANGE PROBABILITIES. 22.12Z GFS A BIT MORE
AGREEMENT WITH MOST UNSTABLE CAPES...WHILE NAM CONFINES 500 J/KG
ACROSS MAINLY THE SOUTHERN SECTIONS. WILL CONTINUE TO MENTION
THUNDER IN THIS TIME FRAME...BUT SEVERE WEATHER IS NOT EXPECTED.
.LONG TERM...THURSDAY THROUGH SUNDAY
300 PM CDT SUN APR 22 2012
MEDIUM RANGE MODELS IN AGREEMENT WITH BUILDING A COOL SURFACE HIGH
INTO THE AREA ON THURSDAY AND WITH THE CLEAR SKIES POTENTIAL EXISTS
FOR SOME FREEZING TEMPERATURES THURSDAY NIGHT...ESPECIALLY ACROSS
THE EASTERN SECTIONS OF THE FORECAST AREA. SURFACE HIGH MOVES EAST
FRIDAY...WITH SHORTWAVE TROUGH PUSHING THROUGH THE PLAINS.
PRECIPITATION WILL BATTLE DRIER AIR NEAR THE HIGH OVER
WISCONSIN...WITH PRECIPITATION PROBABILITIES CONFINED TO THE FAR
SOUTHWEST SECTIONS OF THE FORECAST AREA FRIDAY/FRIDAY NIGHT. STILL
SOME UNCERTAINTY FOR SATURDAY AND SUNDAY...AS GFS WANTS TO BUILD
HIGH BACK INTO THE AREA...WHILE ECMWF SHOVES HIGH EASTWARD ALLOWING
FOR MOISTURE/PRECIPITATION TO MOVE INTO THE AREA FROM THE SOUTHWEST.
FOR NOW WILL KEEP PROBABILITIES IN FOR THIS TIME FRAME BASED ON A
MODEL CONSENSUS.
&&
.AVIATION...
1105 PM CDT SUN APR 22 2012
A WEAK UPPER LEVEL SHORTWAVE TROUGH WILL KEEP A DECK OF 6-8 KFT
CLOUDS ACROSS THE TAF SITES THROUGH 07-08Z...SCATTERING OUT AFTER
THAT. HOWEVER...THE 00Z NAM12/GFS40 AND LATEST RUC13 ALL POINT TO A
SWATH OF SOMEWHAT LOWER SATURATION SLIDING ACROSS WESTERN WI BETWEEN
09-12Z. THIS LOOKS ASSOCIATED WITH SOME 3-6 KFT CEILINGS NEAR THE
TIP OF LAKE SUPERIOR. WILL ADD SOME MENTION OF BKN CIGS IN THIS TIME
FRAME FOR KLSE...BUT WILL KEEP OUT OF KRST FOR NOW. OVERALL
THOUGH...VFR CONDITIONS SHOULD PERSIST INTO MONDAY NIGHT.
WINDS WILL STAY FROM A NORTHERN DIRECTION THROUGH MONDAY. GOOD
MIXING WILL LEAD TO SOME LATE MORNING/AFTERNOON GUSTINESS UPWARDS OF
20+ KTS. WINDS SHOULD DIE OFF VERY QUICKLY MONDAY EVENING AS THE
NOCTURNAL INVERSION SETS UP AND HIGH PRESSURE INFLUENCES THE REGION.
LOOK FOR A RETURN OF SOME HIGH LEVEL CLOUDS BEFORE MIDNIGHT AS MORE
MOISTURE SPILLS ACROSS THE UPPER LEVEL RIDGE AND ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY.
&&
.FIRE WEATHER...
300 PM CDT SUN APR 22 2012
NEAR CRITICAL FIRE WEATHER CONDITIONS POSSIBLE ACROSS CENTRAL...
NORTH CENTRAL...AND PORTIONS OF SOUTHWEST WISCONSIN MONDAY
AFTERNOON. DEEP MIXING MONDAY AFTERNOON WILL ALLOW DEW POINTS TO
PLUMMET...WITH MINIMUM RELATIVE HUMIDITY VALUES FALLING INTO THE 20
TO 25 PERCENT RANGE. IN ADDITION...A TIGHT PRESSURE GRADIENT IS
EXPECTED TO BE IN PLACE EAST OF THE MISSISSIPPI RIVER LEADING TO
NORTH/NORTHWEST WINDS IN THE 10 TO 15 MPH RANGE...WITH GUSTS AROUND
28 MPH POSSIBLE DURING AFTERNOON PEAK HEATING. THE WINDS ARE
EXPECTED TO QUICKLY DIMINISH MONDAY EVENING AS SURFACE HEATING
DECREASES. LOOK FOR HUMIDITIES TO RECOVER QUICKLY AND WINDS TO
RAPIDLY DIMINISH AS HIGH PRESSURE BUILDS IN FROM THE WEST MONDAY
EVENING INTO MONDAY NIGHT. WEST OF THE MISSISSIPPI RIVER...LIGHTER
WINDS ARE EXPECTED ALONG WITH MINIMUM RELATIVE HUMIDITY VALUES IN
THE 28 TO 34 PERCENT RANGE...SO NEAR CRITICAL FIRE WEATHER
CONDITIONS ARE NOT EXPECTED IN THESE AREAS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 PM CDT SUN APR 22 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM.....RABERDING
LONG TERM......RABERDING
AVIATION.......RIECK
FIRE WEATHER...RABERDING/WETENKAMP
AREA FORECAST DISCUSSION
NWS DENVER CO
925 AM MDT MON APR 23 2012
.UPDATE...CURRENT FORECAST ON TRACK. ENOUGH MOISTURE ACROSS
MOUNTAINS AND FOOTHILLS FOR PERHAPS A FEW SHOWERS OR STORMS THIS
AFTERNOON AND EVENING WITH THE BEST CHANCE ALONG THE FOOTHILLS OF
BOULDER AND JEFFERSON COUNTIES WHERE LATEST RUC SHOWS CAPES
INCHING TOWARD 500 J/KG. FORECAST SOUNDINGS SHOW INVERTED-V TYPE
PROFILE...SO THE ACTIVITY HAS THE POTENTIAL TO PRODUCE GUSTY
WINDS...IF THERE IS DEVELOPMENT. OTHERWISE DRY AND WARM CONDITIONS
WILL PREVAIL.
&&
.AVIATION...CURRENT TAF TRENDS LOOK ON TRACK. ANY SHOWERS OR
STORMS THAT DO DEVELOP THIS AFTERNOON WILL BE WEST OF THE DENVER
AREA...SHOULD NOT AFFECT THE AIRPORTS.
&&
.HYDROLOGY...SLIGHT CHANCE FOR SHOWERS OR STORMS OVER THE
MOUNTAINS AND FOOTHILLS THIS AFTERNOON AND EVENING. IF THE
ACTIVITY DOES DEVELOP...RAINFALL WILL BE LESS THAN A TENTH OF AN
INCH.
&&
.PREV DISCUSSION... /ISSUED 420 AM MDT MON APR 23 2012/
SHORT TERM...A WEAK NORTHWEST FLOW ALOFT WILL PREVAIL TODAY AS
THE CENTER OF AN UPPER LEVEL RESIDES OVER UTAH AND WESTERN
COLORADO. WARMER AIR WILL MOVE INTO THE AIR TODAY WITH HIGHS
CLIMBING ABOVE 80 DEGREES ACROSS MOST OF NORTHEAST COLORADO. SKIES
WILL START OFF CLEAR THIS MORNING. AS THE AIRMASS DESTABILIZES OVER
THE MOUNTAINS...CUMULUS CLOUDS WILL FORM. SLIGHT CHANCE FOR ENOUGH
MOISTURE AND INSTABILITY TO PRODUCE A FEW WEAK SHOWERS OR
THUNDERSTORMS OVER THE HIGHER TERRAIN. FOR THE FRONT RANGE AND
EASTWARD...AIRMASS WILL BE TOO DRY AND STABLE FOR ANY SHOWERS OR
THUNDERSTORMS.
LONG TERM...HIGH AMPLITUDE WAVE PATTERN OVER NORTH AMERICA DURING
THE FIRST HALF OF THE WEEK BREAKS DOWN ALLOWING A LONGWAVE UPPER
LEVEL TROUGH TO MOVE OVER WEST COAST LATE ON WEDNESDAY ACCORDING
TO A CONSENSUS OF THE MODELS...AND EVENTUALLY OVER THE CENTRAL
ROCKY MTN REGION BY LATE IN THE DAY THURSDAY AND FRIDAY. 582
DECAMETER HEIGHTS ASSOCIATED WITH THE BROAD UPPER RIDGE OVER
COLORADO ON TUESDAY WILL LIKELY RESULT IN NEAR RECORD
TEMPERATURES...AND POSSIBLY RECORD BREAKING TEMPERATURES. HOWEVER
MID-LEVEL MOISTURE TRAPPED WITHIN THIS RIDGE COUPLED WITH STEEP
LAPSE RATES GENERATED BY VERY WARM BNDRY LAYER TEMPERATURES COULD
SPAWN ISOLATED TO SCATTERED SHOWERS/T-STORMS OVER AND NEAR THE
MOUNTAINS AND FRONT RANGE FOOTHILLS LATE IN THE DAY TUESDAY.
CONVECTION MOVED OFF THE HIGH TERRAIN BY LIGHT WESTERLY TRANSPORT
WINDS WILL PROBABLY GENERATE MORE WIND THAN RAINFALL OVER THE
ADJACENT PLAINS. HENCE THE LOW PRECIP CHANCES IN THIS AREA.
BY WEDNESDAY MODELS SHOW THE UPPER RIDGE WEAKENING SOME AS IT
CONTINUES TO DRIFT EASTWARD OVER THE CENTRAL AND SOUTHERN GREAT
PLAINS. TEMPERATURES STILL QUITE WARM ON WEDNESDAY BUT WITH
COOLING ALOFT AND AN INCREASE IN CLOUD COVER...HIGH TEMPERATURES
ARE EXPECTED TO BE 2-3C COOLER THAN THE DAY BEFORE. AN INCREASE
IN MOISTURE BOTH AT THE SFC AND ALOFT COUPLED WITH STRONG DIABATIC
HEATING IS EXPECTED TO GENERATE A BIT MORE CONVECTION/THUNDERSTORM
ACTIVITY/AREAWIDE. STILL PRECIPITATION LOOKS TO BE ON THE LIGHT
SIDE.
BY THURSDAY...MEDIUM RANGE MODELS GENERALLY SHOW THE UPPER TROUGH
WITH A CLOSED 500MB LOW PASSING OVER THE FOUR CORNERS AREA DURING
THE DAY THURSDAY...THEN SWINGING OUT OVER THE ERN PLAINS OF
COLORADO SOMETIME THURSDAY NIGHT OR EARLY FRIDAY MORNING. THIS
WOULD SET THE STAGE FOR A 24-36 HOUR PD OF COOLER AND UNSETTLED
WEATHER FOR THE CWA. PRIOR TO TROUGH PASSAGE...STIFF SOUTHEASTERLY
FLOW ON THURSDAY USHER IN 50-60F DEWPT TEMPS ON THE PLAINS
ACCORDING TO THE GFS WHICH MODEL SOUNDINGS INDICATE AFTERNOON/
EARLY EVENING CAPE VALUES WELL OVER A 1000 J/KG ACROSS THE
NORTHEAST CORNER OF THE STATE. COULD SEE ISOLATED SUPERCELLS OUT
THERE PRODUCING SEVERE WX...INCLUDING LARGE HAIL.
TROUGH SLOWLY MOVES OUT BY THE WEEKEND. HOWEVER WITH LINGERING
INSTABILITY AND MOISTURE WILL NEED TO HOLD ONTO AT LEAST A SLIGHT
CHANCE OF AFTERNOON AND EVENING SHOWERS/T-STORMS THROUGH SUNDAY.
SHOULD ALSO SEE A GRADUAL WARMUP OVER THE WEEKEND.
AVIATION...AN UPPER LEVEL RIDGE MOVING INTO COLORADO TODAY WILL
BRINGING MOSTLY CLEAR SKIES AND LIGHT WINDS TODAY AND TONIGHT. MAY
BE ENOUGH MOISTURE AND INSTABILITY TO SQUEEZE OUT A FEW WEAK
SHOWERS OR THUNDERSTORMS OVER THE HIGH COUNTRY WEST OF DENVER.
THE DENVER AREA AND EASTWARD WILL BE TOO DRY AND STABLE FOR ANY
SHOWERS OR THUNDERSTORMS.
HYDROLOGY...A FEW WEAK SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE
OVER THE MOUNTAINS AND FOOTHILLS THIS AFTERNOON AND EVENING. IF
ANY ACTIVITY FORMS...IT WILL BE LIGHT AND SHORT LIVED.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....BAKER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1124 AM EDT MON APR 23 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 333 AM EDT MON APR 23 2012
HIGH PRESSURE OVER PLAINS AND DEEP LOW PRESSURE ALONG MID ATLANTIC
COAST MAINTAINING BRISK CONDITIONS ACROSS CENTRAL INDIANA AGAIN
TODAY. WHILE EAST COAST LOW WINDS BACK TO LAKE ONTARIO...WEAK
SHORT WAVES TOPPING WESTERN US RIDGE WILL BRING A FEW PATCHES OF
CLOUD TO WESTERN INDIANA...POSSIBLY WITH SOME LIGHT SHOWERS BY
LATE TUESDAY. FLATTENING UPPER PATTERN AND OPENING OF EAST COAST
UPPER LOW ALLOWS LOW PRESSURE TO WORK ITS WAY INTO GREAT LAKES AND
OHIO VALLEY WEDNESDAY WITH BETTER CHANCES OF SHOWERS AND SOME
STORMS. REMAINING PART OF WEEK WEATHER DEPENDENT ON HOW FAR SOUTH
FRONT WILL PUSH AND CANADIAN HIGH PRESSURE BUILDS IN.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1123 AM EDT MON APR 23 2012
MOSTLY TO COMPLETELY SUNNY SKIES ACROSS THE AREA THIS MORNING WITH
ONLY A FEW WISPY CIRRUS IN PLACES. TEMPERATURES ESPECIALLY IN
THE WESTERN COUNTIES ARE RISING A BIT FASTER THAN FORECAST AND
BASED ON 850 ADVECTION THINK THIS WILL CONTINUE INTO THE AFTERNOON
AND RESULT IN HIGHS A COUPLE DEGREES WARMER THAN EARLIER FORECAST
YIELDING UPPER 50S IN THE EAST TO LOW 60S IN THE WEST. RUC AND
HRRR ARE SHOWING WIND GUSTS A BIT STRONGER THAN GOING FORECAST AS
WELL SO BUMPED THOSE UP ESPECIALLY IN THE EAST WHERE THE GRADIENT
WILL BE TIGHTER TO 30-35 KTS DURING THE AFTERNOON. WITH THIS IN
MIND WILL ALSO ISSUE AN SPS MOMENTARILY TO HIGHLIGHT THESE GUSTY
WINDS. MOST DEW POINTS WERE ON TRACK BUT TWEAKED THOSE THAT WERE
A BIT HIGHER/LOWER TO MATCH CURRENT CONDITIONS AND WILL HAVE TO
WATCH THESE THIS AFTERNOON IF THEY MIX DOWN FURTHER AND UPDATE IF
THIS HAPPENS DUE TO THE EFFECT ON FIRE WEATHER THREAT.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 333 AM EDT MON APR 23 2012
PRIMARY ISSUE IS PRECIPITATION CHANCES BEGINNING LATE TUESDAY.
ANOTHER VERY COOL NIGHT EXPECTED TONIGHT BUT WITH WINDS REMAINING
UP ENOUGH TO PREVENT ANY FROST. WILL ALSO BE FLIRTING WITH
FREEZING TEMPERATURES ACROSS NORTHERN COUNTIES TONIGHT BUT WITH
MAXS TODAY TAD WARMER THAN SUNDAY AND WITH MIXING THROUGH THE
NIGHT EXPECT MINS TO STAY 33 OR 34 DEGREES AT COLDEST.
CLOUDS INCREASE ESPECIALLY ACROSS WESTERN COUNTIES TUESDAY
AFTERNOON AS WEAK SHORT WAVE DROPS SOUTHEAST FROM CANADA. NAM AND
GFS ALSO DEVELOP ENOUGH LIFT FOR SLIGHT RAIN CHANCES SO HAVE ADDED
CHANCE OF SHOWERS TO SOUTHERN COUNTIES. MAX TEMPERATURES WITH
HIGHER THICKNESSES SHOULD TOP OUT A CATEGORY HIGHER AT LEAST TUESDAY
WITH LOWER TO MIDDLE 60S MOST AREAS.
AS SFC WARM FRONT BEGINS TO SET UP JUST SOUTH OF FORECAST
AREA...CONTINUED LOW THREAT FOR SHOWERS INTO TUESDAY NIGHT.
CLOUDIER SKIES AND WARM ADVECTION WILL ALSO KEEP MIN TEMPS IN LOWER
TO MIDDLE 40S.
COMBINATION OF SURFACE TROUGH IN AREA AND SOMEWHAT STRONGER SHORT
WAVE DROPPING SOUTHEAST IN NORTHWEST UPPER FLOW...SCATTERED
SHOWERS AND THUNDERSTORMS APPEAR PRETTY GOOD BET FOR WEDNESDAY AND
WEDNESDAY NIGHT. MILDER MAX TEMPS IN 70S AND MINS IN 50S SHOULD
ACCOMPANY THIS SYSTEM BEFORE COOL HIGH BEGINS TO BUILD IN AGAIN BY
THURSDAY. OUTSIDE POTENTIAL FOR SOME LOCALLY HEAVY RAIN WEDNESDAY
NIGHT BUT TOO EARLY TO DETERMINE WHERE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/
DISAGREEMENT BETWEEN GFS AND EURO IS MAKING POPS CHALLENGING FOR
MOST OF THE EXTENDED PERIOD. AT THIS TIME...THE EURO IS PULLING
POPS OUT OF THE AREA ON THURSDAY MORNING FASTER THAN THE GFS.
SO...IT/S REALLY A MATTER OF WHICH MODEL YOU CHOOSE...AND AM NOT
PARTIAL TO ONE OR THE OTHER AT THIS TIME. SO...WILL STAY WITH LATEST
INITIALIZATION OF SLIGHT CHANCE POPS ACROSS THE SOUTHERN HALF OF
FORECAST AREA THROUGH THURSDAY MORNING.
DRY CONDITIONS WILL PREVAIL ON THURSDAY AND THURSDAY NIGHT...BUT IT
WILL BE SHORT-LIVED AS THE NEXT LOW EJECTS OUT OF THE CENTRAL PLAINS
AT THE END OF THE WEEK. ONCE AGAIN...SIGNIFICANT MODEL UNCERTAINTY
WITH THE GFS BEING MORE PROGRESSIVE THAN EURO. INITIALIZATION SEEMS
TO BE BEST BET AT THIS TIME WITH SLIGHT CHANCE POPS ON FRIDAY
MORNING AND AFTERNOON...AND THEN INCREASING TO CHANCE POPS ON FRIDAY
EVENING. TOO MUCH VARIATION IN TIMING AND INTENSITY OF PRECIP TO GO
ANY HIGHER THAN CHANCE POPS THROUGH THE WEEKEND...BUT MODELS DO
AGREE ON KEEPING PRECIP AROUND THROUGH SUNDAY NIGHT.
TEMPS...DEVIATED FROM INITIALIZATION NUMBERS ON SATURDAY/S HIGHS.
TRENDED ON THE WARM SIDE DUE TO IMPENDING WARM FRONT WITH
AFOREMENTIONED LOW PRESSURE SYSTEM.
&&
.AVIATION /DISCUSSION FOR THE 231200Z TAF ISSUANCE/...
ISSUED AT 1052 AM EDT MON APR 23 2012
1030Z UPDATE...NO UPDATES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS...
ISSUED AT 653 AM EDT MON APR 23 2012
VFR CONDITIONS WILL PREVAIL FOR ENTIRE TAF PERIOD WITH LARGE RIDGE
OF HIGH PRESSURE ANCHORED OVER THE CENTRAL U.S.
HOWEVER...A TIGHT PRESSURE GRADIENT BETWEEN THE AFOREMENTIONED
RIDGE AND DEEP TROUGH OVER THE NORTHEAST U.S. WILL RESULT IN GUSTY
NORTH/NORTHWESTERLY WINDS THROUGH THIS EVENING. WINDS WILL START
INCREASING AROUND MID TO LATE MORNING AND CONTINUE TO STRENGTHEN
THROUGH MIDDAY. SUSTAINED SPEEDS WILL RANGE BETWEEN 18 TO 20 KTS
WITH GUSTS TO 30 KTS AT KLAF AND KIND. WINDS WILL BE A TAD LIGHTER
AT KHUF AND KBMG WHERE THE GRADIENT WON/T BE AS TIGHT. SUSTAINED
SPEEDS AT THOSE SITES WILL RANGE FROM 10 TO 14 KTS WITH GUSTS TO
25 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TUCEK
NEAR TERM...CP
SHORT TERM...TUCEK
LONG TERM....TDUD
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1037 AM EDT MON APR 23 2012
.SYNOPSIS...
BREEZY AND COOL CONDITIONS WILL PREVAIL TODAY AS CANADIAN HIGH
PRESSURE BUILDS INTO THE AREA. BELOW NORMAL TEMPERATURES THROUGH
EARLY WEDNESDAY WILL BE FOLLOWED BY A WARMING TREND LATE IN THE
WEEK AHEAD OF AN APPROACHING COLD FRONT. A WEAK FRONT ON FRIDAY
MAY BE FOLLOWED BY A STRONGER COLD FRONT NEXT SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10:30 AM MONDAY...COLD POOL ALOFT AND ATTENDANT STEEP LAPSE
RATES ARE COMBINING WITH LOWER LEVEL MOISTURE TO FORM A RATHER
EXTENSIVE CU FIELD...ESPECIALLY OVER OUR NORTHERN COUNTIES WHERE
IT IS THICKENING UP NICELY. LATEST HRRR RUN AND SOME OTHER
GUIDANCE SHOWS ISOLATED AFTERNOON SHOWERS OVER THESE AREAS OF
GREATEST CLOD COVER IS STILL A POSSIBILITY FOR THIS AFTERNOON.
WILD CARD COULD BE WHETHER WE GET TOO MUCH CLOUD COVER...THUS
KEEPING SURFACE TEMPS TOO LOW FOR CONVECTION. WIND PROFILES SHOW
ANY SHOWERS THAT DO FORM COULD PULL DOWN SOME HEFTY GUSTS.
PREVIOUS DISCUSSION FOLLOWS:
SEVERAL OF THE RAPID UPDATE MODELS ARE NOW POINTING TO MID-LATE
AFTERNOON SHOWERS BENEATH THE COLD POOL ALOFT DESPITE THE DRY SUB-
CLOUD AIR. HAVE UPDATED ZONES TO ACCOUNT FOR THIS POTENTIAL. ANY
SHOWERS WILL BE CAPABLE OF IMPARTING GUSTY W AND WNW WINDS TO THE
SURFACE...DUE TO THE INVERTED-V PROFILE OF AFTN SOUNDINGS. THE
PREVIOUS MORNING DISCUSSION FOLLOWS.
PICTURES FROM SPACE EARLY THIS MORNING SHOW STRONG LOW PRESSURE
SLAMMING INTO THE SOUTHERN NEW ENGLAND COAST DRIVEN BY A COLD POOL
ALOFT MOVING INTO THE CENTRAL APPALACHIANS. THESE FEATURES
INTERACTING WITH BUILDING HIGH PRESSURE FROM THE MISSISSIPPI VALLEY
WILL DRIVE A BRISK WNW WIND FLOW TODAY ACROSS THE AREA. SURFACE
ANALYSIS SHOWS FALLING DEWPOINTS PUSHING SE OVER MUCH OF THE SE AND
MID-ATLC...WITH BOTH NAM-12 AND THE EURO MODEL SHOWING TD VALUES IN
THE 30S BY MID AFTERNOON OVER OUR AREA.
MAXIMUMS LOW-MID 60S THIS AFTN...POSSIBLY MILDEST OVER EASTERN ZONES
WHERE DOWNSLOPE COMPONENT TRAVELS FARTHEST. AFTER CLEARING WE WILL
LIKELY SEE AFTERNOON CUMULUS BENEATH THE COLD POOL AMID SHARP LAPSE
RATES. THE CU COULD BECOME MODERATE AND CAPABLE OF GENERATING A FEW
SHOWERS IN GUSTY WINDS BETWEEN 3-6 PM.
PATCHY FROST REMAINS A THREAT EARLY TUESDAY...WITH LOWS IN THE
MIDDLE TO UPPER 30S OVER PROTECTED AREAS FROM W WIND FLOW. NO
FROST ADVISORY PLANNED THIS PACKAGE SINCE VAST UNCERTAINTY
EXISTS ON SPATIAL COVERAGE OF FROST...BUT A COURTESY SPS AT A
MINIMUM WOULD SEEM APPROPRIATE LATER TODAY.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3:00 AM MONDAY...DEEP EAST COAST TROUGH WILL CONTINUE TO BE
THE STORY AT LEAST FOR ONE MORE DAY BEFORE LIFTING OUT AS THE
PATTERN FLATTENS BY EARLY THURSDAY.
MAIN FORECAST CHALLENGE EVOLVES AROUND POPS FOR LATE TUESDAY INTO
WEDNESDAY AM WITH THE LAST OF THE FORMIDABLE EMBEDDED SHORTWAVES
MOVING ACROSS. NWP GUIDANCE HAS BEEN TRENDING A BIT MORE AGGRESSIVE
WITH THIS FEATURE AND HAVE ADDED SLIGHT CHANCE POPS CENTERED AROUND
0600 UTC WEDNESDAY FROM SOUTH TO NORTH FOLLOWING THE GFS. THE NAM
HAS THE FEATURE BUT DEVELOPS ACTIVITY A BIT MORE OFFSHORE. WEDNESDAY
SHOULD BE SUNNY ALTHOUGH IT IS WORTH NOTING THE NAM HAS YET ANOTHER
SHORTWAVE THAT WOULD CERTAINLY CHANGE THE FORECAST IF IT VERIFIES.
TEMPERATURE GUIDANCE IS STABLE WITH THE ONLY REAL CHALLENGE BEING
WEDNESDAY MORNING LOWS WHERE I CONTINUED TO GO SLIGHTLY ABOVE
GUIDANCE WITH A MIXED BOUNDARY LAYER.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3:00 AM MONDAY...EXTENDED WARRANTS FEW CHANGES
THIS MORNING AS THE MEDIUM RANGE MODELS ARE RELATIVELY UNCHANGED.
INITIAL OMEGA PATTERN WILL DEVELOP INTO A MODEST RIDGE BY THE END
OF THE PERIOD OVER THE SOUTHEAST. ONLY SURFACE FEATURE OF NOTE IS
THE BACKDOOR FRONT SLATED FOR A LATE THURSDAY/EARLY FRIDAY PASSAGE
ACROSS OUR AREA. MAINTAINED THE SLIGHT CHANCE POPS FOR THIS FEATURE
THURSDAY AND THROUGH SATURDAY AS THE ECMWF...THE PREFERRED SOLUTION
FROM HPC SHOWS INDICATIONS OF THE BOUNDARY LINGERING ACROSS SOUTHERN
ZONES. NO CHANGES TO TEMPERATURE GUIDANCE WHICH SHOW THE LARGEST
DEVIATION FROM NORMAL...ON THE WARM SIDE FRIDAY MORNING...OTHERWISE
NOTHING REALLY OUT OF THE ORDINARY.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...PRECIP ASSOCIATED WITH A TROUGH ROTATING AROUND THE
UPPER LOW HAVE MOVED OFFSHORE. COLD CORE WILL MOVE OVERHEAD THIS
AFTERNOON. MODELS INDICATE THERE WILL BE ENOUGH MOISTURE TO PRODUCE
INSTABILITY SHOWERS THIS AFTERNOON...BEGINNING NEAR MAX HEATING.
COVERAGE WILL BE LIMITED...SO ONLY A VCSH MENTION. IF A TERMINAL
MANAGES TO GET A SHOWER...TEMPERATURE COULD DROP BY TEN DEGREES OR
MORE WITH SQUALLY TYPE WINDS. EVEN WITHOUT THE CONVECTION...WINDS
WILL GUST WELL INTO THE TWENTIES TODAY...DIMINISHING THIS EVENING.
EXTENDED OUTLOOK...VFR WITH LOW CHANCES OF PRECIPITATION THROUGH THE
PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10:30 AM MONDAY...CONDITIONS OVER THE WATERS CONTINUE TO BE
JUST BAD ENOUGH TO WARRANT A SMALL CRAFT ADVISORY. COLD SURGE OVER
THE WATERS CREATING FREQUENT GUSTS UP AROUND 25 KTS. COASTAL AND
BUOY OBS SHOW SEAS IN THE 4 TO 6 FT RANGE. NO CHANGES TO EARLIER
THINKING...WHICH IS DETAILED IN PREVIOUS DISCUSSION BELOW:
ADVISORIES WILL BE NEEDED TODAY FOR GUSTY NW WINDS BEHIND AN
EXITING COLD FRONT. GUSTS TO 25-30 KT SHOULD BE EXPECTED
TODAY...AND INTO VERY EARLY EVENING OVER OUR NORTHERN WATERS WHERE
THE PRESSURE GRADIENT WILL BE A BIT MORE CRAMPED. INSHORE SEA-
HEIGHTS WILL SUBSIDE AS THE OFFSHORE FLOW PREVAILS. NO TSTMS
EXPECTED ON THE 0-20NM WATERS AS DRIER AIR SPREADS OVER THE AREA.
PATCHY DZ EARLY WILL TRACK ACROSS THE WATERS INTO DAWN. RESIDUAL
SE WAVES WILL CO-MINGLE WITH NW WIND-WAVES TODAY MAKING FOR A
BUMPY AND HAZARDOUS SEAS TODAY.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3:00 AM MONDAY...BLUSTERY CONDITIONS CONTINUE FOR AT LEAST ONE
MORE DAY FOR THE MARINE COMMUNITY AS A STRONG SHORTWAVE MOVES ACROSS
IN THE MEAN FLOW LATE TUESDAY. EXPECT WEST TO SOUTHWEST WINDS OF
15-20 KNOTS FOR MOST OF THE DAY TUESDAY TURNING TO NORTHWEST BY
WEDNESDAY MORNING AS THE ASSOCIATED SURFACE TROUGH MOVES ACROSS.
PATTERN RELAXES A BIT WEDNESDAY AND WIND DROP TO WESTERLY AROUND
TEN KNOTS. THE HIGHER SEAS...FIVE FEET...REMAIN CONFINED TO OFFSHORE
WATERS WITH 2-4 FEET ACROSS THE COASTAL ZONES. BY WEDNESDAY EVENING
SEAS SHOULD BE AROUND TWO FEET ACROSS ALL WATERS.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3:00 AM MONDAY...THURSDAY THROUGH FRIDAY...MAIN FEATURE WILL BE
THE FRONT MOVING ACROSS THE WATERS EARLY FRIDAY WITH A WIND SHIFT
FROM SOUTHWEST TO NORTHWEST. WINDS VEER FURTHER TO THE EAST LATER
FRIDAY BUT SPEEDS SHOULD REMAIN TEPID AS THERE IS LITTLE COLD AIR
ADVECTION. SEAS INCREASE FROM 3-5 FEET EARLY TO 5-7 FEET MOSTLY
CONFINED TO THE OUTER WATERS LATE THURSDAY AS A STRONG SOUTHWEST
FLOW DEVELOPS AHEAD OF THE PREVIOUSLY MENTIONED BOUNDARY. SEAS DROP
APPRECIABLY LATER FRIDAY WITH THE CHANGE IN FETCH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR AMZ254-
256.
SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR AMZ250-
252.
&&
$$
SYNOPSIS...REK/SHK
NEAR TERM...MJC/REK
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
MARINE...MJC/REK/SHK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
653 AM EDT MON APR 23 2012
.SYNOPSIS...
DEVELOPING LOW PRESSURE SYSTEM MOVES NORTH ALONG THE MID ATLANTIC
COAST THROUGH TODAY. UPPER LEVEL LOW MOVES SOUTHEAST THIS MORNING. A
CLIPPER LIKE SYSTEM WILL AFFECT THE AREA BY MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGES SHOW A BATCH OF MAINLY RAIN UNDER TEMPERATURES ABOVE
35 DEGREES...MOVING FROM CENTRAL TO SOUTHEAST WV EARLY THIS
MORNING. SFC OBS OVER HIGHER ELEVATIONS INDICATE TEMPERATURES
BELOW 33 DEGREES REPORTING SNOW. THE HIGH RESOLUTION HRRR MODEL
DEPICTS THIS FEATURE VERY GOOD. IT ALSO INDICATE A SECOND BATCH OF
PCPN DIGGING SOUTH ACROSS THE EASTERN HALF OF THE AREA BY 16-17Z.
WITH TEMPERATURES STAYING BELOW FREEZING...EXPECT RELAY ON THIS
MODEL...SUPPORTED BY THE RUC13 ON THIS SECOND BATCH OF SNOW FOR
THE EASTERN MOUNTAINS.
HIGHEST ELEVATIONS OF POCAHONTAS COUNTY ALREADY WITH ONE INCH OF
SNOW DEPTH. EXPECT HEAVY WET SNOW TO REALLY PICK UP OF THE THE
WARNING COUNTIES FROM 8 AM TO 4 PM THIS AFTERNOON...AS SUGGESTED
BY MODELS.
MINOR CHANGES MADE TO POPS/WEATHER GRIDS. NO CHANGES MADE TO
WINTER WARNING AND ADVISORIES.
EXPECT A TEMPERATURE GRADIENT FROM THE LOWER 50S NEARBY HTS...AND
NORTHEAST KY...RANGING TO THE LOWER 30S NORTHEAST MOUNTAINS FOR
HIGHS TODAY.
COLD TEMPERATURES TONIGHT MAY NEED A FREEZE WARNING FOR EASTERN
MOUNTAINS AND PORTIONS OF NORTHERN WV.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
GENERALLY WENT WITH GFS/SREF/ECMWF MODEL BLEND THROUGH THIS
PERIOD...WITH NAM BEING THE OUTLIER. SFC LOW OVER NORTHERN GREAT
LAKES WILL CONTINUE TO MOVE NORTHWARD AND ITS AFFECTS WILL DEPART
WITH IT...BUT KEPT SOME LINGERING MOISTURE AND POPS IN THE
NORTHERN MOUNTAIN ZONES DURNING THE DAY ON TUESDAY...WITH GRADUAL
DECREASE. A WEAK UPPER LEVEL SYSTEM SLIDES SOUTH OF THE CWA ON
TUESDAY AS WELL...WITH MOST OF THE ENERGY STAYING SOUTH OF CWA. IN
ANY CASE KEPT SLGHT CHC POPS ACROSS EXTREME SW AND SRN PORTION OF
CWA ON TUESDAY AS WELL. BRIEF BREAK BEFORE MORE VIGOROUS SYSTEM
MOVES DOWN FROM THE UPPER MIDWEST AND TRACKS ACROSS THE CWA
WENDESDAY NIGHT AND THURSDAY. TEMPERATURES WILL GRADUALLY WARM
TRHOUGH THE PERIOD AS SOUTHERLY FLOW WILL INCREASE ON TUESDAY AND
WEDNESDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
UNSETTLED WEATHER EXPECTED IN THE LONG TERM. CLIPPER TYPE SYSTEM
WILL MOVE THROUGH THE REGION ON THURSDAY...BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. COLD FRONT ASSOCIATED WITH THIS SYSTEM
WILL PUSH THROUGH THE AREA LATE THURSDAY...BEFORE STALLING TO OUR
SOUTH ON FRIDAY AS HIGH PRESSURE BRIEFLY BUILDS IN FROM THE
NORTH...PROVIDING A BRIEF BREAK IN THE WEATHER. AS USUAL...QUITE A
BIT OF UNCERTAINTY IN THE LATTER PART OF THE EXTENDED...BUT APPEARS
AS THOUGH ANOTHER WAVE OF LOW PRESSURE WILL PUSH THROUGH THE AREA BY
SUNDAY...BRINGING YET ANOTHER ROUND OF PRECIPITATION TO THE AREA.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
TRIED TO PINPOINT PCPN TRANSITION FROM RAIN...TO MIXED WITH
SNOW...TO ALL SNOW ACROSS EKN...PKB AND BKW MONDAY MORNING. SNOW
SHOWERS WILL AFFECT THESE SITES THROUGH AT LEAST 21Z MONDAY. OTHER
SITES WILL EXPERIENCE VFR/MVFR DRIZZLE WITH OCCASIONAL WEST TO
NORTHWEST FLOW...THROUGH THE PERIOD.
INCORPORATED SREF PROBABILITIES FOR IFR/LIFR LOW CEILINGS ACROSS
THE MOUNTAINS REFINING WITH MESOSCALE AND MICROCLIMATE EFFECTS
OVER HIGHEST ELEVATIONS AND UPSLOPE AREAS. HAVE WORST CONDITIONS
AT CKB...EKN AND BKW FROM 12-149Z. BUT CONTINUING AT EKN AND CKB
THROUGH 21Z UNDER SNOW SHOWERS.
IN THE LOWLANDS...CONDITIONS WILL START TO IMPROVE TO VFR MON AFTERNOON AS
THE PRECIPITATION TAPERS OFF.
IN THE MOUNTAINS...HIGH RESOLUTION MODELS INDICATED A SECOND BATCH
OF PCPN MOSTLY SNOW SHOWERS OVER THE EASTERN MOUNTAINS BY 17Z. CONDITIONS
MAY START TO IMPROVE TO MVFR AS RAIN AND SNOW MIXED STARTS TO
TAPER OFF LATE THIS EVENING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: HEAVIER SNOW SHOWERS MAY CAUSE FURTHER
REDUCTION IN CIG AND VSBY VALUES. TIMING OF PRECIP ONSET AND IFR /
LIFR IN SNOW MAY VARY.
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.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EDT 1HRLY 07 08 09 10 11 12 13 14 15 16 17 18
CRW CONSISTENCY M M H H H H H M H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M M M M M L M L L M M M
EKN CONSISTENCY M M M M M M M M L L L L
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY M M H L H H L M L M M M
AFTER 12Z TUESDAY...
IFR CONDITIONS IN MOUNTAIN SNOW AND LINGERING LOW CLOUDS MON
NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR WVZ032-
037>040.
WINTER STORM WARNING UNTIL MIDNIGHT EDT TONIGHT FOR WVZ046-047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JS/ARJ
NEAR TERM...ARJ
SHORT TERM...JS
LONG TERM...SL
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS TUCSON AZ
255 PM MST MON APR 23 2012
.SYNOPSIS...HIGH PRESSURE WILL WEAKEN AND RESULT IN SLIGHTLY COOLER
TEMPERATURES THROUGH THURSDAY. A LOW PRESSURE SYSTEM WILL TRACK
THROUGH THE GREAT BASIN ON THURSDAY BRINGING COOLER
TEMPERATURES...BREEZY TO WINDY CONDITIONS AND SCATTERED SHOWERS.
THEREAFTER...DRY NORTHWESTERLY FLOW WILL KEEP DAYTIME TEMPERATURES
RIGHT AROUND NORMAL.
&&
.DISCUSSION...LATEST WATER VAPOR SATELLITE IMAGERY SHOWS SHORTWAVE
MOVING ACROSS NORTHERN BAJA INTO SOUTHERN CALI/SOUTHEAST AZ. PRECIP
WATERS AROUND HALF AN INCH MIXING WITH A VERY UNSTABLE AIRMASS HAS
ALLOWED AFTERNOON BUILDUPS ACROSS MUCH OF SOUTHEAST ARIZONA AND
ALONG THE MOGOLLON RIM. A FEW LIGHTNING STRIKES HAVE BEEN OBSERVED
ACROSS EXTREME NORTHWEST CHIHUAHUA AND WESTERN NEW MEXICO...BUT
CURRENTLY NO STRIKES IN SOUTHEAST ARIZONA. LATEST HRRR SOLUTION
SUPPORTS CURRENT THINKING OF SOME ENHANCEMENT OF CLOUD COVER AS
SHORTWAVE APPROACHES BUT STILL ONLY A SLIGHT CHANCE OF CONVECTION.
SO FAR RADAR REMAINS ECHO FREE. INCREASING SOUTHWEST WINDS HAVE
ALLOWED STRONG MIXING AGAIN THIS AFTERNOON WITH TUCSON RETURNING TO
THE CENTURY MARK BREAKING THE MAX TEMPERATURE RECORD FOR TODAY.
HIGH PRESSURE PROGGED TO WEAKEN THE NEXT SEVERAL DAYS AS AN AREA OF
LOW PRESSURE APPROACHES THE WESTERN COAST. THIS WILL RESULT IN A
SLIGHT BREAK IN THE HEAT WITH VALLEY TEMPERATURES RETURNING TO THE
UPPER 80S/LOW 90S...STILL A FEW DEGREES ABOVE NORMAL.
SOME MODEL DISAGREEMENT STILL EXISTS WITH APPROACHING SYSTEM.
NAM/SREF/DGEX SOLUTIONS BRING UPPER LEVEL LOW ONSHORE ABOUT 6 HOURS
EARLIER THAN GFS/EUROPEAN SOLUTIONS...WITH THE UKMET BEING EVEN
SLOWER THAN THE GFS/EURO. AS A RESULT...NAM/SREF/DGEX SOLUTIONS
BRING COLD FRONT THROUGH SOUTHERN ARIZONA WITH ASSOCIATED PRECIP 6
TO 12 HOURS EARLIER THAN GFS/EURO SOLUTIONS. BASED ON RUN TO RUN
CONTINUITY AND PAST PERFORMANCE...HAVE TRENDED FORECAST TO MORE OF A
GFS/EUROPEAN BLEND. POSITIONING AND TRAJECTORY OF THE LOW WILL TAP
ABUNDANT MOISTURE...PRECIP WATERS IN EXCESS OF ONE INCH...IN THE
PACIFIC AND RESULT IN GOOD MOISTURE ADVECTION ACROSS THE REGION.
SHOWERS SHOULD START ALONG THE COLD FRONT ACROSS THE WESTERN DESERTS
WEDNESDAY NIGHT/THURSDAY MORNING AND PUSH NORTHEAST. BEST MOISTURE
SOURCE WILL REMAIN NORTH OF THE AREA WITH PRECIP WATERS IN PHOENIX
REACHING UP TO AN INCH AND A QUARTER...WHILE TUCSON WILL BE AROUND
ONE INCH. DOUGLAS PRECIP WATERS WILL BE ONLY AROUND HALF AN INCH.
SHOWERS WILL BE MOSTLY TIED TO THE FRONT ACROSS SOUTHERN
ARIZONA...SO EXPECT ONLY AN HOUR OR TWO OF PRECIP AS THE FRONT
QUICKLY PUSHES THROUGH THURSDAY LATE MORNING/EARLY AFTERNOON.
MOISTURE WILL BE LIMITED ACROSS EXTREME SOUTHEAST ARIZONA...SO ITS
POSSIBLE LOCATIONS ALONG THE INTERNATIONAL BORDER MAY BE LEFT OUT OF
THIS EVENT. THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE ALONG THE
FRONT DUE TO ADDITIONAL LIFT IN AN UNSTABLE AND MOIST AIRMASS. GOOD
UPSLOPE FLOW WILL ALSO ENHANCE ANY PRECIP ACROSS THE HIGHER TERRAIN.
RAISED POPS TO SCATTERED CATEGORY...BUT WILL PROBABLY NEED TO
FURTHER RAISE POPS ONCE MODELS COME INTO BETTER AGREEMENT. STRONG
SOUTHWEST WINDS WILL ALSO PERSIST IN ADVANCE OF THE FRONT WITH
BREEZY TO WINDY CONDITIONS POSSIBLE TUCSON EWD. TEMPERATURES
THURSDAY WILL RANGE FROM THE UPPER 70S/LOW 80S IN THE VALLEYS
THURSDAY DUE TO CLOUD COVER AND PRECIP BUT WILL QUICKLY REBOUND
FRIDAY.
DRY NORTHWESTERLY FLOW WILL USHER IN BEHIND THE STORM SYSTEM
ALLOWING TEMPERATURES TO RETURN TO SLIGHTLY ABOVE NORMAL...BUT NOT
BACK TO THE HIGH TEMPERATURES WE HAVE SEEN THE PAST SEVERAL
DAYS.
&&
.AVIATION...MID LEVEL MOISTURE ACROSS THE EASTERN HALF OF SOUTHEAST
ARIZONA WILL RESULT IN A FEW AFTERNOON BUILDUPS TODAY AND TUESDAY.
FROM KTUS EASTWARD EXPECT SCT CLOUDS AT 8-11K FT AGL...AND SCT-BKN
CLOUDS AOA 20K FT AGL THRU 24/04Z...THEN AFT 24/04Z FEW-SCT CLOUDS
AOA 20K FT AGL. FROM KTUS WESTWARD...EXPECT SCT-BKN CLOUDS AOA 20K
FT AGL THRU 24/02Z...THEN SKC CONDITIONS. SLY/SWLY SURFACE WIND AT
10-15 KTS WITH GUSTS TO AROUND 25 KTS THRU 24/03Z...WITH STRONGEST
WINDS EAST OF KTUS...THEN SURFACE WIND GENERALLY LESS THAN 10 KTS
THRU 24/15Z. SWLY/WLY SURFACE WIND AT 8-13 KTS WITH GUSTS TO AROUND
22 KTS LATE TUESDAY MORNING AND TUESDAY AFTERNOON. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES WILL
CONTINUE THROUGH WEDNESDAY. A FEW AFTERNOON AND EARLY EVENING
BUILDUPS WILL BE POSSIBLE OVER THE EASTERN HALF OF SOUTHEAST ARIZONA
TODAY AND TUESDAY...WITH THE POSSIBILITY OF A DRY LIGHTNING STRIKE
OR TWO. ALSO EXPECT SOME AFTERNOON AND EARLY EVENING BREEZES TODAY
AND TUESDAY. A STRONG STORM SYSTEM WILL THEN APPROACH THE REGION ON
WEDNESDAY...RESULTING IN STRONG AND GUSTY WINDS. THIS SYSTEM WILL
MOVE ACROSS THE STATE ON THURSDAY...WITH MUCH COOLER TEMPERATURES
AND A CHANCE OF SHOWERS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
MINNICK
WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1125 AM MDT MON APR 23 2012
.UPDATE...
ISSUED AT 1124 AM MDT MON APR 23 2012
HAVE MADE SOME MINOR ADJUSTMENTS TO POPS FIELD TO FIT CURRENT
TRENDS IN BOTH THE HRRR-3KM AND RUC13 MODELS. CURRENT CU FIELD
BUILDING OVER THE HIGH COUNTRY THIS MORNING AND INCREASING HEAT
AND INSTABILITY WILL ALLOW A FEW HIGH BASED STORMS TO DEVELOP
LATER TODAY. FOCUS WILL BE ACROSS THE SAN JUAN MOUNTAINS. HOURLY
POP GRIDS HAVE BEEN UPDATED AND NEW POINT AND CLICK FORECASTS WILL
REFLECT THESE ADJUSTMENTS. MAIN ZONE PACKAGE WILL NOT BE UPDATED
ATTM.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 322 AM MDT MON APR 23 2012
A HUGE RIDGE WILL DOMINATE THE WEATHER OVER THE WESTERN U.S. FOR
THE NEXT SEVERAL DAYS. THE MAIN MESSAGE FOR TODAY WILL BE NEAR
RECORD TO RECORD HIGH TEMPERATURES AGAIN TODAY. 700 MB TEMPS
CONTINUE TO RISE...REACHING PLUS 10 TO 12 DEGREES LATE THIS
AFTERNOON. THIS MORNING A STRING OF WEAK VORT MAXES FLOWING
BENEATH DIVERGENCE ALOFT WILL PRODUCE A STRONG OF SHOWERS
EXTENDING ACROSS SRN ID AND SW WY WITH A LINE OF MID AND HI CLOUDS
RIDING OVER THE CREST OF THE RIDGE AND INTO NE UT AND WRN CO. THE
TRAJECTORY OF THE VORT MAXES SHOULD TAKE THEM NORTH AND NORTHEAST
INTO ID AND WY...SO BELIEVE ON THESE WILL NO AFFECT THE FORECAST
AREA.
THE FIRST IN A SERIES SMALLISH WAVES WILL AFFECT THE AREA LATE
TONIGHT INTO TUE MORNING AS THE UPPER RIDGE BEGINS TO SLIDE EAST
AND DE-AMPLIFY. THIS FIRST WAVE WAS CURRENTLY SOUTHWEST OF SRN CA
AND IS EXPECTED TO REACH THE 4 CORNERS BY 12Z TUE BUT WILL BE
WEAKENING AS IT ENCOUNTERS THE RIDGE...BUT COULD STILL GENERATE
SOME ISOLATED SHOWER OR THUNDERSTORM THROUGH TUE MORNING. BOTH
NAM/GFS HAVE IT CROSSING WRN CO MIDDAY TUE. MOISTURE NOT
GREAT...BUT ENOUGH MID-LEVEL MOISTURE LIKELY TO BE PRESENT FOR
ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS TUE AFTERNOON. ACTUAL
PRECIPITATION AT THE SURFACE LOOKS TO BE LITTLE OR NONE...HOWEVER.
MAIN STORY TUESDAY WILL BE THE ADDITION OF A LITTLE MORE WIND TO THE
CONTINUED MUCH ABOVE NORMAL TEMPS AND LOW DAYTIME HUMIDITIES. DEEP
MIXING FROM DAYTIME HEATING AND SOME STRENGTHENING OF THE SW FLOW
BEHIND THE RIDGE AXIS SHOULD LEAD TO SOME GUSTY WINDS TUE AFTERNOON
ESPECIALLY FROM NW CO TO NRN SAN JUAN COUNTY UTAH. THE FIRE WEATHER
WATCH FOR PORTIONS OF NW CO AND NE UT STILL STILL LOOKS ON TRACK.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 322 AM MDT MON APR 23 2012
TUESDAY NIGHT-WEDNESDAY NIGHT: SOME BRIEF DRYING INDICATED IN THE
700-500 MB LAYER SPECIFIC HUMIDITY TUE EVENING BEHIND THAT FIRST
WAVE...BUT THE GENERAL TREND STILL LOOKS TO BE GRADUALLY INCREASING
MOISTURE FOR WED. ANOTHER UPPER WAVE PASSES TUE NIGHT THAT COULD
KEEP ISOLATED SHOWERS PRESENT AND MAY COOL THINGS A FEW DEGREES ON
WED. CLOUDS ON THE INCREASE FROM THE SOUTHWEST WED NIGHT AS A MORE
SIGNIFICANT UPPER TROUGH APPROACHES.
BY THURSDAY MORNING THE MAIN PACIFIC TROUGH WILL BE MOVING
ONSHORE AND THE NAM12 SHOWS A STRONG SHORTWAVE TROUGH EJECTING
TROUGH SRN CA AND NW AZ...THEN REACHING THE FOUR CORNERS BY NOON.
THE GFS SHOWS THIS TROUGH MUCH STRONGER AND CLOSED OFF OVER SRN CA
THU MORNING. IT MOVES THIS FEATURE MORE SLOWLY THRU AZ AND KEEPS
IT CLOSED AS IT MOVES INTO WESTERN NM LATE THU AFTERNOON. THE
CONSENSUS IN THE MODELS CALLS FOR INCREASING CLOUDS...A BETTER
CHANCE OF PRECIPITATION AND COOLER TEMPS THU. THE BEST CHANCE OF
PRECIP SHOULD BE LATE THU AFTERNOON THRU THU NIGHT. MODEL
SOLUTIONS FOR FRIDAY HAVE THE MAIN TROUGH LINE EAST OF THE AREA...
WITH NW WINDS AND COOL ADVECTION OVER WRN CO AND ERN UT. SAT AND
SUN LOOK LIKE RELATIVELY DRY NORTHWEST FLOW OVER THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1107 AM MDT MON APR 23 2012
VFR CONDITIONS WILL PREVAIL ACROSS THE FORECAST AREA. ISOLATED
HIGH-BASED THUNDERSTORMS WILL DEVELOP OVER THE MOUNTAINS THIS
AFTERNOON AND DRIFT ACROSS THE HIGHER VALLEYS THIS EVENING. LITTLE
OR NO RAIN WILL REACH THE GROUND WITH THESE STORMS...ALTHOUGH GUSTY
OUTFLOW WINDS TO NEAR 50 MPH WILL BE POSSIBLE.
&&
.FIRE WEATHER...
ISSUED AT 322 AM MDT MON APR 23 2012
RECORD TO NEAR RECORD WARMTH WILL CONTINUE TODAY THROUGH TUESDAY.
AFTERNOON HUMIDITY WILL DROP TO THE LOWER TEENS AND SINGLE DIGITS
OVER MANY VALLEY LOCATIONS MONDAY AND TUESDAY. VERTICAL MIXING
WILL BE STRONG...LEADING TO GUSTY AFTERNOON WINDS...STRONGER NEAR
HIGH-BASED THUNDERSTORMS THAT ARE POSSIBLE OVER RIDGES THIS
AFTERNOON. AREAL COVERAGE OF THUNDERSTORMS AND BRIEF WIND GUSTS
WILL LIMIT CRITICAL FIRE WEATHER CONDITIONS TODAY. ON TUESDAY
HOWEVER...WINDS ALOFT WILL INCREASE AND THE CHANCE OF SUSTAINED
WINDS AND GUSTS OVER 25 MPH WILL INCREASE. BECAUSE OF THIS...A
FIRE WEATHER WATCH HAS BEEN CONTINUED FOR CO FIRE ZONES 200 AND
202 AND UT FIRE ZONE 444 FOR CRITICAL FUELS...GUSTY WINDS...AND
LOW HUMIDITIES. COOLER AND MORE MOIST CONDITIONS CAN BE EXPECTED
THROUGH LATE WEEK AS PRECIPITATION CHANCES ALSO INCREASE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR COZ200-202.
UT...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR UTZ444.
&&
$$
UPDATE...JDC
SHORT TERM...CJC/JAD
LONG TERM...JAD/CJC
AVIATION...JDC
FIRE WEATHER...CC
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
127 PM EDT MON APR 23 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 333 AM EDT MON APR 23 2012
HIGH PRESSURE OVER PLAINS AND DEEP LOW PRESSURE ALONG MID ATLANTIC
COAST MAINTAINING BRISK CONDITIONS ACROSS CENTRAL INDIANA AGAIN
TODAY. WHILE EAST COAST LOW WINDS BACK TO LAKE ONTARIO...WEAK
SHORT WAVES TOPPING WESTERN US RIDGE WILL BRING A FEW PATCHES OF
CLOUD TO WESTERN INDIANA...POSSIBLY WITH SOME LIGHT SHOWERS BY
LATE TUESDAY. FLATTENING UPPER PATTERN AND OPENING OF EAST COAST
UPPER LOW ALLOWS LOW PRESSURE TO WORK ITS WAY INTO GREAT LAKES AND
OHIO VALLEY WEDNESDAY WITH BETTER CHANCES OF SHOWERS AND SOME
STORMS. REMAINING PART OF WEEK WEATHER DEPENDENT ON HOW FAR SOUTH
FRONT WILL PUSH AND CANADIAN HIGH PRESSURE BUILDS IN.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1123 AM EDT MON APR 23 2012
MOSTLY TO COMPLETELY SUNNY SKIES ACROSS THE AREA THIS MORNING WITH
ONLY A FEW WISPY CIRRUS IN PLACES. TEMPERATURES ESPECIALLY IN
THE WESTERN COUNTIES ARE RISING A BIT FASTER THAN FORECAST AND
BASED ON 850 ADVECTION THINK THIS WILL CONTINUE INTO THE AFTERNOON
AND RESULT IN HIGHS A COUPLE DEGREES WARMER THAN EARLIER FORECAST
YIELDING UPPER 50S IN THE EAST TO LOW 60S IN THE WEST. RUC AND
HRRR ARE SHOWING WIND GUSTS A BIT STRONGER THAN GOING FORECAST AS
WELL SO BUMPED THOSE UP ESPECIALLY IN THE EAST WHERE THE GRADIENT
WILL BE TIGHTER TO 30-35 KTS DURING THE AFTERNOON. WITH THIS IN
MIND WILL ALSO ISSUE AN SPS MOMENTARILY TO HIGHLIGHT THESE GUSTY
WINDS. MOST DEW POINTS WERE ON TRACK BUT TWEAKED THOSE THAT WERE
A BIT HIGHER/LOWER TO MATCH CURRENT CONDITIONS AND WILL HAVE TO
WATCH THESE THIS AFTERNOON IF THEY MIX DOWN FURTHER AND UPDATE IF
THIS HAPPENS DUE TO THE EFFECT ON FIRE WEATHER THREAT.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 333 AM EDT MON APR 23 2012
PRIMARY ISSUE IS PRECIPITATION CHANCES BEGINNING LATE TUESDAY.
ANOTHER VERY COOL NIGHT EXPECTED TONIGHT BUT WITH WINDS REMAINING
UP ENOUGH TO PREVENT ANY FROST. WILL ALSO BE FLIRTING WITH
FREEZING TEMPERATURES ACROSS NORTHERN COUNTIES TONIGHT BUT WITH
MAXS TODAY TAD WARMER THAN SUNDAY AND WITH MIXING THROUGH THE
NIGHT EXPECT MINS TO STAY 33 OR 34 DEGREES AT COLDEST.
CLOUDS INCREASE ESPECIALLY ACROSS WESTERN COUNTIES TUESDAY
AFTERNOON AS WEAK SHORT WAVE DROPS SOUTHEAST FROM CANADA. NAM AND
GFS ALSO DEVELOP ENOUGH LIFT FOR SLIGHT RAIN CHANCES SO HAVE ADDED
CHANCE OF SHOWERS TO SOUTHERN COUNTIES. MAX TEMPERATURES WITH
HIGHER THICKNESSES SHOULD TOP OUT A CATEGORY HIGHER AT LEAST TUESDAY
WITH LOWER TO MIDDLE 60S MOST AREAS.
AS SFC WARM FRONT BEGINS TO SET UP JUST SOUTH OF FORECAST
AREA...CONTINUED LOW THREAT FOR SHOWERS INTO TUESDAY NIGHT.
CLOUDIER SKIES AND WARM ADVECTION WILL ALSO KEEP MIN TEMPS IN LOWER
TO MIDDLE 40S.
COMBINATION OF SURFACE TROUGH IN AREA AND SOMEWHAT STRONGER SHORT
WAVE DROPPING SOUTHEAST IN NORTHWEST UPPER FLOW...SCATTERED
SHOWERS AND THUNDERSTORMS APPEAR PRETTY GOOD BET FOR WEDNESDAY AND
WEDNESDAY NIGHT. MILDER MAX TEMPS IN 70S AND MINS IN 50S SHOULD
ACCOMPANY THIS SYSTEM BEFORE COOL HIGH BEGINS TO BUILD IN AGAIN BY
THURSDAY. OUTSIDE POTENTIAL FOR SOME LOCALLY HEAVY RAIN WEDNESDAY
NIGHT BUT TOO EARLY TO DETERMINE WHERE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/
DISAGREEMENT BETWEEN GFS AND EURO IS MAKING POPS CHALLENGING FOR
MOST OF THE EXTENDED PERIOD. AT THIS TIME...THE EURO IS PULLING
POPS OUT OF THE AREA ON THURSDAY MORNING FASTER THAN THE GFS.
SO...IT/S REALLY A MATTER OF WHICH MODEL YOU CHOOSE...AND AM NOT
PARTIAL TO ONE OR THE OTHER AT THIS TIME. SO...WILL STAY WITH LATEST
INITIALIZATION OF SLIGHT CHANCE POPS ACROSS THE SOUTHERN HALF OF
FORECAST AREA THROUGH THURSDAY MORNING.
DRY CONDITIONS WILL PREVAIL ON THURSDAY AND THURSDAY NIGHT...BUT IT
WILL BE SHORT-LIVED AS THE NEXT LOW EJECTS OUT OF THE CENTRAL PLAINS
AT THE END OF THE WEEK. ONCE AGAIN...SIGNIFICANT MODEL UNCERTAINTY
WITH THE GFS BEING MORE PROGRESSIVE THAN EURO. INITIALIZATION SEEMS
TO BE BEST BET AT THIS TIME WITH SLIGHT CHANCE POPS ON FRIDAY
MORNING AND AFTERNOON...AND THEN INCREASING TO CHANCE POPS ON FRIDAY
EVENING. TOO MUCH VARIATION IN TIMING AND INTENSITY OF PRECIP TO GO
ANY HIGHER THAN CHANCE POPS THROUGH THE WEEKEND...BUT MODELS DO
AGREE ON KEEPING PRECIP AROUND THROUGH SUNDAY NIGHT.
TEMPS...DEVIATED FROM INITIALIZATION NUMBERS ON SATURDAY/S HIGHS.
TRENDED ON THE WARM SIDE DUE TO IMPENDING WARM FRONT WITH
AFOREMENTIONED LOW PRESSURE SYSTEM.
&&
.AVIATION /DISCUSSION FOR THE 231800Z TAF ISSUANCE/...
ISSUED AT 118 PM EDT MON APR 23 2012
VFR CONDITIONS WILL PREVAIL FOR ENTIRE TAF PERIOD (THOUGH IT
CONTINUE TO BE QUITE GUSTY THROUGH THIS AFTERNOON) WITH A LARGE
RIDGE OF HIGH PRESSURE ANCHORED OVER THE CENTRAL U.S.
A TIGHT PRESSURE GRADIENT BETWEEN THE AFOREMENTIONED RIDGE AND
DEEP TROUGH OVER THE NORTHEAST U.S. WILL ALLOW GUSTY
NORTH/NORTHWESTERLY WINDS THROUGH EARLY THIS EVENING. SUSTAINED
SPEEDS WILL RANGE BETWEEN 18 TO 20 KTS WITH GUSTS TO 30-33 KTS AT
KLAF AND KIND. WINDS WILL BE A TAD LIGHTER AT KHUF AND KBMG WHERE
THE GRADIENT IS NOT QUITE AT STRONG. WINDS WILL DECREASE AND GUSTS
WILL DROP OFF TONIGHT...BUT STILL STAY AOA 5-7 KT OVERNIGHT. WINDS
PICK BACK UP TO AROUND 10 KT TUE MORNING AROUND 15Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TUCEK
NEAR TERM...CP
SHORT TERM...TUCEK
LONG TERM....TDUD
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1206 PM EDT MON APR 23 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 333 AM EDT MON APR 23 2012
HIGH PRESSURE OVER PLAINS AND DEEP LOW PRESSURE ALONG MID ATLANTIC
COAST MAINTAINING BRISK CONDITIONS ACROSS CENTRAL INDIANA AGAIN
TODAY. WHILE EAST COAST LOW WINDS BACK TO LAKE ONTARIO...WEAK
SHORT WAVES TOPPING WESTERN US RIDGE WILL BRING A FEW PATCHES OF
CLOUD TO WESTERN INDIANA...POSSIBLY WITH SOME LIGHT SHOWERS BY
LATE TUESDAY. FLATTENING UPPER PATTERN AND OPENING OF EAST COAST
UPPER LOW ALLOWS LOW PRESSURE TO WORK ITS WAY INTO GREAT LAKES AND
OHIO VALLEY WEDNESDAY WITH BETTER CHANCES OF SHOWERS AND SOME
STORMS. REMAINING PART OF WEEK WEATHER DEPENDENT ON HOW FAR SOUTH
FRONT WILL PUSH AND CANADIAN HIGH PRESSURE BUILDS IN.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1123 AM EDT MON APR 23 2012
MOSTLY TO COMPLETELY SUNNY SKIES ACROSS THE AREA THIS MORNING WITH
ONLY A FEW WISPY CIRRUS IN PLACES. TEMPERATURES ESPECIALLY IN
THE WESTERN COUNTIES ARE RISING A BIT FASTER THAN FORECAST AND
BASED ON 850 ADVECTION THINK THIS WILL CONTINUE INTO THE AFTERNOON
AND RESULT IN HIGHS A COUPLE DEGREES WARMER THAN EARLIER FORECAST
YIELDING UPPER 50S IN THE EAST TO LOW 60S IN THE WEST. RUC AND
HRRR ARE SHOWING WIND GUSTS A BIT STRONGER THAN GOING FORECAST AS
WELL SO BUMPED THOSE UP ESPECIALLY IN THE EAST WHERE THE GRADIENT
WILL BE TIGHTER TO 30-35 KTS DURING THE AFTERNOON. WITH THIS IN
MIND WILL ALSO ISSUE AN SPS MOMENTARILY TO HIGHLIGHT THESE GUSTY
WINDS. MOST DEW POINTS WERE ON TRACK BUT TWEAKED THOSE THAT WERE
A BIT HIGHER/LOWER TO MATCH CURRENT CONDITIONS AND WILL HAVE TO
WATCH THESE THIS AFTERNOON IF THEY MIX DOWN FURTHER AND UPDATE IF
THIS HAPPENS DUE TO THE EFFECT ON FIRE WEATHER THREAT.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 333 AM EDT MON APR 23 2012
PRIMARY ISSUE IS PRECIPITATION CHANCES BEGINNING LATE TUESDAY.
ANOTHER VERY COOL NIGHT EXPECTED TONIGHT BUT WITH WINDS REMAINING
UP ENOUGH TO PREVENT ANY FROST. WILL ALSO BE FLIRTING WITH
FREEZING TEMPERATURES ACROSS NORTHERN COUNTIES TONIGHT BUT WITH
MAXS TODAY TAD WARMER THAN SUNDAY AND WITH MIXING THROUGH THE
NIGHT EXPECT MINS TO STAY 33 OR 34 DEGREES AT COLDEST.
CLOUDS INCREASE ESPECIALLY ACROSS WESTERN COUNTIES TUESDAY
AFTERNOON AS WEAK SHORT WAVE DROPS SOUTHEAST FROM CANADA. NAM AND
GFS ALSO DEVELOP ENOUGH LIFT FOR SLIGHT RAIN CHANCES SO HAVE ADDED
CHANCE OF SHOWERS TO SOUTHERN COUNTIES. MAX TEMPERATURES WITH
HIGHER THICKNESSES SHOULD TOP OUT A CATEGORY HIGHER AT LEAST TUESDAY
WITH LOWER TO MIDDLE 60S MOST AREAS.
AS SFC WARM FRONT BEGINS TO SET UP JUST SOUTH OF FORECAST
AREA...CONTINUED LOW THREAT FOR SHOWERS INTO TUESDAY NIGHT.
CLOUDIER SKIES AND WARM ADVECTION WILL ALSO KEEP MIN TEMPS IN LOWER
TO MIDDLE 40S.
COMBINATION OF SURFACE TROUGH IN AREA AND SOMEWHAT STRONGER SHORT
WAVE DROPPING SOUTHEAST IN NORTHWEST UPPER FLOW...SCATTERED
SHOWERS AND THUNDERSTORMS APPEAR PRETTY GOOD BET FOR WEDNESDAY AND
WEDNESDAY NIGHT. MILDER MAX TEMPS IN 70S AND MINS IN 50S SHOULD
ACCOMPANY THIS SYSTEM BEFORE COOL HIGH BEGINS TO BUILD IN AGAIN BY
THURSDAY. OUTSIDE POTENTIAL FOR SOME LOCALLY HEAVY RAIN WEDNESDAY
NIGHT BUT TOO EARLY TO DETERMINE WHERE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/
DISAGREEMENT BETWEEN GFS AND EURO IS MAKING POPS CHALLENGING FOR
MOST OF THE EXTENDED PERIOD. AT THIS TIME...THE EURO IS PULLING
POPS OUT OF THE AREA ON THURSDAY MORNING FASTER THAN THE GFS.
SO...IT/S REALLY A MATTER OF WHICH MODEL YOU CHOOSE...AND AM NOT
PARTIAL TO ONE OR THE OTHER AT THIS TIME. SO...WILL STAY WITH LATEST
INITIALIZATION OF SLIGHT CHANCE POPS ACROSS THE SOUTHERN HALF OF
FORECAST AREA THROUGH THURSDAY MORNING.
DRY CONDITIONS WILL PREVAIL ON THURSDAY AND THURSDAY NIGHT...BUT IT
WILL BE SHORT-LIVED AS THE NEXT LOW EJECTS OUT OF THE CENTRAL PLAINS
AT THE END OF THE WEEK. ONCE AGAIN...SIGNIFICANT MODEL UNCERTAINTY
WITH THE GFS BEING MORE PROGRESSIVE THAN EURO. INITIALIZATION SEEMS
TO BE BEST BET AT THIS TIME WITH SLIGHT CHANCE POPS ON FRIDAY
MORNING AND AFTERNOON...AND THEN INCREASING TO CHANCE POPS ON FRIDAY
EVENING. TOO MUCH VARIATION IN TIMING AND INTENSITY OF PRECIP TO GO
ANY HIGHER THAN CHANCE POPS THROUGH THE WEEKEND...BUT MODELS DO
AGREE ON KEEPING PRECIP AROUND THROUGH SUNDAY NIGHT.
TEMPS...DEVIATED FROM INITIALIZATION NUMBERS ON SATURDAY/S HIGHS.
TRENDED ON THE WARM SIDE DUE TO IMPENDING WARM FRONT WITH
AFOREMENTIONED LOW PRESSURE SYSTEM.
&&
.AVIATION /DISCUSSION FOR THE 231200Z TAF ISSUANCE/...
ISSUED AT 1203 PM EDT MON APR 23 2012
1600Z UPDATE...WINDS ARE PICKING UP AND GUSTING VERY STRONG AN
HOUR OR TWO THAN EARLIER EXPECTED...AND ARE ACTUALLY A LITTLE
STRONGER AT LOCATIONS SUCH AS KIND. ALL TAFS HAVE BEEN UPDATED TO
REFLECT THIS STRONGER GUSTY TREND FOR THE REST OF THIS ATFTERNOON.
PREVIOUS DISCUSSIONS FOLLOW...
ISSUED AT 1052 AM EDT MON APR 23 2012
1030Z UPDATE...NO UPDATES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS...
ISSUED AT 653 AM EDT MON APR 23 2012
VFR CONDITIONS WILL PREVAIL FOR ENTIRE TAF PERIOD WITH LARGE RIDGE
OF HIGH PRESSURE ANCHORED OVER THE CENTRAL U.S.
HOWEVER...A TIGHT PRESSURE GRADIENT BETWEEN THE AFOREMENTIONED
RIDGE AND DEEP TROUGH OVER THE NORTHEAST U.S. WILL RESULT IN GUSTY
NORTH/NORTHWESTERLY WINDS THROUGH THIS EVENING. WINDS WILL START
INCREASING AROUND MID TO LATE MORNING AND CONTINUE TO STRENGTHEN
THROUGH MIDDAY. SUSTAINED SPEEDS WILL RANGE BETWEEN 18 TO 20 KTS
WITH GUSTS TO 30 KTS AT KLAF AND KIND. WINDS WILL BE A TAD LIGHTER
AT KHUF AND KBMG WHERE THE GRADIENT WON/T BE AS TIGHT. SUSTAINED
SPEEDS AT THOSE SITES WILL RANGE FROM 10 TO 14 KTS WITH GUSTS TO
25 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TUCEK
NEAR TERM...CP
SHORT TERM...TUCEK
LONG TERM....TDUD
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
358 PM EDT MON APR 23 2012
.SYNOPSIS...
DEEP LOW PRESSURE, MOVING SLOWLY NORTHWARD THROUGH NEW YORK STATE,
CAN STILL CAUSE GUSTY WINDS AND A MIX OF RAIN AND SNOW SHOWERS
TONIGHT. THE HIGHER MOUNTAINS CAN YET GET ADDITIONAL
ACCUMULATIONS OF WET SNOW. MIDWEST HIGH PRESSURE WILL COME
SLOWLY EASTBOUND TO PROVIDE DRY CONDITIONS AND MODERATING
TEMPERATURES BY WEDNESDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
PER RECENT SURFACE AND RADAR DATA, HAVE RAISED WIND GUST VALUES TO
OVER 45 MPH ACROSS EAST CENTRAL OHIO AND THE WEST VIRGINIA
NORTHERN PANHANDLE, AND SO HAVE ISSUED A WIND ADVISORY FOR THOSE
PARTS THROUGH EARLY EVENING. FURTHER EAST, WINDS CAN GUST TO 40
MPH, AS THE STRONG LOW PRESSURE SYSTEM CONTINUES TO MOVE NORTHWARD
THROUGH NEW YORK STATE.
RECENT RADAR DATA CONTINUES TO SHOW THE ASSOCIATED FRONTOGENETICALLY-
FORCED WRAP-AROUND PRECIPITATION SHIELD AFFECTING THE HIGHER
MOUNTAINS AND NORTHWEST PENNSYLVANIA I-80 CORRIDOR. WET SNOW
ACCUMULATIONS CAN OCCUR WHERE TEMPERATURES ARE COLDER THAN 34
DEGREES. TRENDS IN RADAR DATA AND HRRR AND NAM MODEL OUTPUT SHOW
THE PRECIPITATION BAND WILL BECOME MORE NORTHWEST TO SOUTHEAST
ORIENTED THIS EVENING, AND THEN SLOWLY EXIT NORTH LATE TONIGHT AND
TUESDAY MORNING.
HAVE MAINTAINED WINTER STORM WARNING THROUGH EARLY TONIGHT, AS
EXPECT ANY NEW WET SNOW ACCUMULATIONS WILL BE RESTRICTED TO THE
HIGHER MOUNTAINS.
FORECASTED LOW TEMPERATURES TONIGHT USING BLEND OF GFS AND NAM
MOS, WHICH SHOWED LOWS NO LOWER THAN THE UPPER 20S ACROSS THE
HIGHER MOUNTAINS AND NO WARMER THAN THE THE MID 30S ELSEWHERE.
TEMPERATURES WILL MODERATE DAYTIME TUESDAY, BUT AFTERNOON HIGHS
WILL BE MORE THAN 10 DEGREES COLDER THAN NORMAL PER RECENT GFS AND
NAM MOS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT SHOWS A SLOW EASTBOUND HIGH PRESSURE
SYSTEM PROVIDING THE UPPER OHIO VALLEY WITH A DRY BREAK TUESDAY
NIGHT INTO WEDNESDAY EVENING. THEN A LOW PRESSURE, COMING
SOUTHEAST FROM THE CANADIAN PRAIRIES, WILL BRING SHOWERS LATE
WEDNESDAY NIGHT AND POSSIBLY THUNDERSTORMS DAYTIME THURSDAY.
FORECASTED TEMPERATURES TO BE CLOSER TO SEASONABLE VALUES BASED ON
BLEND OF RECENT GFS AND NAM MOS AND SREF MEAN VALUES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
DRY WEATHER IS EXPECTED FRIDAY AND SATURDAY AS SURFACE HIGH PRESSURE
BUILDS SOUTHEASTWARD OVER THE GREAT LAKES. MEDIUM RANGE MODELS SHOW
A LOW PRESSURE SYSTEM TRACKING EAST FROM THE PLAINS AND ACROSS THE
OHIO VALLEY SUNDAY...BRINGING SCATTERED SHOWERS. SURFACE HIGH
PRESSURE SHOULD REBUILD BEHIND THIS SYSTEM TO PROVIDE DRY WEATHER
FOR MONDAY.
TEMPERATURES ARE FORECAST TO REMAIN BETWEEN 5 AND 10 DEGREES BELOW
NORMAL THROUGH THE EXTENDED PERIOD.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
SURFACE LOW PRESSURE WILL CONTINUE TO TRACK SLOWLY NORTH INTO
SOUTHERN ONTARIO BY LATE TUESDAY. MVFR RESTRICTIONS AND AREAS OF IFR
WILL LIKELY PERSIST IN MIX OF RAIN AND SNOW ACROSS THE WESTERN PA
AND NORTHERN WEST VIRGINIA TERMINALS THROUGH TONIGHT. CONDITIONS ARE
EXPECTED TO IMPROVE TO VFR AT ALL TERMINALS EXCEPT KFKL AND KDUJ BY
LATE TUESDAY MORNING. CONDITIONS WILL REMAIN VFR AT KZZV THROUGH THE
TAF PERIOD.
NORTHWEST SURFACE WINDS WILL GUST TO 30 TO 35KT AT TIMES THROUGH
EARLY EVENING...THEN GRADUALLY SUBSIDE TO 15 TO 25KT OVERNIGHT.
.OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
A LOW PRESSURE SYSTEM PROGGED TO CROSS THE UPPER OHIO VALLEY WILL
BRING SCATTERED SHOWERS AND THE POTENTIAL FOR RESTRICTIONS LATE
WEDNESDAY NIGHT AND THURSDAY. BUILDING HIGH PRESSURE SHOULD SUPPORT
VFR WEATHER FOR FRIDAY AND SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 2 AM EDT TUESDAY FOR MDZ001.
OH...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ039>041-
048>050-057>059-068-069.
PA...WINTER STORM WARNING UNTIL 2 AM EDT TUESDAY FOR PAZ009-016-023-
074-076.
WV...WIND ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ001>004-012.
WINTER STORM WARNING UNTIL 2 AM EDT TUESDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
636 PM EDT MON APR 23 2012
.SYNOPSIS...
ISSUED AT 414 PM EDT MON APR 23 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITH
A MID/UPPER LEVEL RIDGE OVER THE WRN CONUS AND A TROUGH OVER THE
EAST RESULTING IN CONFLUENT NRLY FLOW THROUGH THE UPPER GREAT LAKES.
AN UPSTREAM SHORTWAVE TROUGH MOVING INTO NRN MANITOBA SUPPORTED AN
EXTENSIVE AREA OF CLOUDS AND A FEW LIGHT SHOWERS. AT THE SFC...THE
GRADIENT WAS INCREASING BTWN LOW PRESSURE OVER ERN NY AND A RIDGE
OVER THE UPPER MS VALLEY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 414 PM EDT MON APR 23 2012
AS THE SHORTWAVE TROUGH MOVES TOWARD THE AREA...EXPECT MID CLOUDS TO
INCREASE LATE TONIGHT. THE GFS WAS MORE AGGRESSIVE WITH 290K
ISENTROPIC LIFT AND PCPN POTENTIAL COMPARED TO THE REST OF THE
MODELS. SO...GIVEN THE LACK OF MOISTURE AVBL AND THE RELATIVELY
MODEST DYNAMICS...ONLY SLIGHT CHANCE POPS WERE INCLUDED OVER WEST.
SOME INLAND TEMPS MAY FALL TO NEAR FREEZING BUT SOUNDINGS SUGGEST
THAT PCPN TYPE WOULD BE RAIN.
RELATIVELY POOR RH RECOVERY IS EXPECTED OVERNIGHT ACROSS THE
AREA...BUT MOST SIGNIFICANTLY OVER THE EASTERN HALF. EVEN WITH THE
LOSS OF DAYTIME HEATING/MIXING 9250 MB WINDS IN THE 40 TO 45 KT
RANGE...FROM 03Z TO 15Z TUESDAY. AFTER AREAS OF CLOUDS WITH THE
SHRTWV MOVE OUT BY AFTERNOON...SUNSHINE AND MIXING SHOULD AGAIN DROP
DEWPOINTS BLO GUIDANCE TO AROUND 20F. WITH TEMPERATURES INTO THE MID
AND UPPER 50S...RH VALUES NEAR 25 PCT WILL AGAIN LEAD TO ELEVATED WILD
FIRE RISK.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 414 PM EDT MON APR 23 2012
LOW PRESSURE SYSTEM CURRENTLY OVER NEW YORK WILL BE LOCATED OVER
WRN QUEBEC AT THE START OF THE PERIOD AND WILL PUSH N AND WEAKEN
WHILE THE UPPER RIDGE THAT HAS BEEN OVER THE WRN CONUS APPROACHES
THE WRN GREAT LKS. WEAK SHORTWAVE MOVING THROUGH THE NW FLOW ALOFT
ON TUES NIGHT INTO WED...WHILE ASSOCIATED SFC LOW SLIDES FROM THE
DAKOTAS TOWARDS THE LOWER GREAT LAKES. BROAD H850-500 WAA...Q-VECTOR
CONV...AND MOISTURE PUSHING IN SLOWLY TUES EVENING AND CONTINUES
THROUGH WED. ECMWF FARTHEST SW WITH THE BEST WAA...WHILE NAM/GFS/GEM
ALL TRY TO FOCUS A STRONGER AREA OF WAA OVER THE NRN CWA ON WED.
THESE DIFFERENCES LEAD TO SOME UNCERTAINTY ON THE EXACT LOCATION OF
THE RAIN. IN ADDITION...DRY AIR BELOW H800 WILL TRY TO LIMIT PCPN
CHANCES THROUGH MUCH OF THE OVERNIGHT HOURS OVER THE FAR WRN CWA.
ATMO DOESN/T REALLY SEEM TO MOISTEN UP UNTIL DAYLIGHT HOURS ON WED.
THIS DELAYED MOISTENING WILL LIMIT PCPN ACROSS THE REST OF THE CWA
FOR THE FIRST PART OF WED. HAVE TRIED TO PUT SOME TIMING IN FOR THIS
DRY AIR HOLDING OFF PCPN. EVEN WITH THE DRY AIR...SEEM TO HAVE
ENOUGH SIGNALS TO BUMP CHANCE POPS UP A LITTLE MORE...ESPECIALLY
OVER THE WRN CWA DURING THE DAY WED. THE INITIAL DRY AIR AND
POSITIONING OF THE PCPN PROVIDES A LITTLE TOO MUCH UNCERTAINTY TO
BUMP THEM UP TO LIKELY VALES.
MUCH STRONGER WAVE AND ASSOCIATED HEIGHT FALLS ARRIVES LATE WED
NIGHT AND THURS MORNING...WHICH BRING THE MUCH COOLER H850 TEMPS TO
THE AREA. THE COLD AIR ON THE BACK SIDE OF THE SYSTEM COULD LEAD TO
LK ENHANCED CLOUDS/PCPN LINGERING BEHIND THE WAVE INTO THURS
MORNING. NAM HOLDING ON TO THE LLVL MOISTURE THROUGH THE MORNING
HOURS BEFORE THE DRIER AIR AND SUBSIDENCE FROM THE HIGH PRESSURE
RIDGE START TO TAKE OVER. WITH THE NRLY FLOW OVER THE AREA DURING
THE MORNING...COMBINING WITH A BRIEF OVERLAP OF THE H850 TEMPS TO
-8C AND MOISTURE...THINK THERE WILL BE A BRIEF PERIOD OF STRONGER
RAIN/SNOW SHOWERS OVER THE NCNTRL UPSLOPE LOCATIONS MAINLY FROM
06-15Z. MAIN CONCERN WITH SNOW IS THAT THE LLVL TEMPS MIGHT NOT GET
COLD ENOUGH TO SUPPORT SNOW UNTIL THE BEST MOISTURE DEPARTS.
THUS...DELAYED THE SNOW CHANGE OVER TO OCCUR LATER IN THE NIGHT AND
DURING THE FIRST PART OF THURS MORNING. SNOW WILL OCCUR A LITTLE
EARLY OVER THE NW HALF OF THE CWA...BUT BOTH CASES WILL NEED A
LITTLE WHILE TO COOL CLOUD TEMPS AND GET ICE CRYSTALS BACK IN THE
CLOUD DUE TO THE DRY H750 AIR ARRIVING WED EVENING.
WITH THE HIGH PRESSURE RIDGE QUICKLY MOVING IN ON THURS AND LLVL
MOISTURE DEPARTING FOR ALL BUT FAR ERN UPPER MI...WILL DECREASE THE
CLOUDS ACROSS THE AREA EVEN THOUGH H850 TEMPS ARE STILL AROUND -6
OR -7C. COULD BE A LITTLE GUSTY WITH THE STRONG PRESSURE GRADIENT
LATE WED NIGHT INTO THURS. WITH THE COLD AIR ARRIVING AND H925
WINDS TO 30KTS...SHOULD SEE GUSTS IN THE 30-35MPH RANGE NEAR LK
SUPERIOR IN THE MORNING AND THEN DIMINISHING FORM WEST TO EAST
THROUGH THE DAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 635 PM EDT MON APR 23 2012
THE STRENGTHENING PRESSURE GRADIENT BETWEEN THE RETROGRADING
HIGH...AND ATLANTIC LOW PUSHING ACROSS THE LOWER GREAT LAKES THIS
EVENING WILL RESULT IN INCREASED NW WINDS AT CMX AND ESPECIALLY SAW.
VFR CONDITIONS SHOULD REMAIN THROUGH THE NEXT 24 HOURS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 414 PM EDT MON APR 23 2012
A STRONG LOW PRESSURE SYSTEM WILL MOVE NNE INTO THE ERN GREAT LAKES
BY THIS EVENING. THIS HAS RESULTED IN INCREASING NNW WINDS...UP TO
30KTS OVER ERN LK SUPERIOR WHICH WILL CONTINUE INTO TUESDAY MORNING.
A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE UPPER LAKES ON WED WHILE
BEFORE STRONG HIGH PRESSURE BUILDS FROM CENTRAL CANADA INTO THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY. THE STRONG GRADIENT
BETWEEN THESE SYSTEMS WILL LEAD TO NORTHERLY GUSTS UP TO 30KTS
OVER CENTRAL AND EASTERN LAKE SUPERIOR WEDNESDAY NIGHT INTO THURSDAY
MORNING. A FEW GALE FORCE GUSTS TO 35KTS ARE ALSO POSSIBLE DURING
THIS TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR MIZ006>008-
013>015-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
EXTENDED...JMW
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 PM EDT MON APR 23 2012
.SYNOPSIS...
ISSUED AT 414 PM EDT MON APR 23 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITH
A MID/UPPER LEVEL RIDGE OVER THE WRN CONUS AND A TROUGH OVER THE
EAST RESULTING IN CONFLUENT NRLY FLOW THROUGH THE UPPER GREAT LAKES.
AN UPSTREAM SHORTWAVE TROUGH MOVING INTO NRN MANITOBA SUPPORTED AN
EXTENSIVE AREA OF CLOUDS AND A FEW LIGHT SHOWERS. AT THE SFC...THE
GRADIENT WAS INCREASING BTWN LOW PRESSURE OVER ERN NY AND A RIDGE
OVER THE UPPER MS VALLEY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 414 PM EDT MON APR 23 2012
AS THE SHORTWAVE TROUGH MOVES TOWARD THE AREA...EXPECT MID CLOUDS TO
INCREASE LATE TONIGHT. THE GFS WAS MORE AGGRESSIVE WITH 290K
ISENTROPIC LIFT AND PCPN POTENTIAL COMPARED TO THE REST OF THE
MODELS. SO...GIVEN THE LACK OF MOISTURE AVBL AND THE RELATIVELY
MODEST DYNAMICS...ONLY SLIGHT CHANCE POPS WERE INCLUDED OVER WEST.
SOME INLAND TEMPS MAY FALL TO NEAR FREEZING BUT SOUNDINGS SUGGEST
THAT PCPN TYPE WOULD BE RAIN.
RELATIVELY POOR RH RECOVERY IS EXPECTED OVERNIGHT ACROSS THE
AREA...BUT MOST SIGNIFICANTLY OVER THE EASTERN HALF. EVEN WITH THE
LOSS OF DAYTIME HEATING/MIXING 9250 MB WINDS IN THE 40 TO 45 KT
RANGE...FROM 03Z TO 15Z TUESDAY. AFTER AREAS OF CLOUDS WITH THE
SHRTWV MOVE OUT BY AFTERNOON...SUNSHINE AND MIXING SHOULD AGAIN DROP
DEWPOINTS BLO GUIDANCE TO AROUND 20F. WITH TEMPERATURES INTO THE MID
AND UPPER 50S...RH VALUES NEAR 25 PCT WILL AGAIN LEAD TO ELEVATED WILD
FIRE RISK.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 414 PM EDT MON APR 23 2012
LOW PRESSURE SYSTEM CURRENTLY OVER NEW YORK WILL BE LOCATED OVER
WRN QUEBEC AT THE START OF THE PERIOD AND WILL PUSH N AND WEAKEN
WHILE THE UPPER RIDGE THAT HAS BEEN OVER THE WRN CONUS APPROACHES
THE WRN GREAT LKS. WEAK SHORTWAVE MOVING THROUGH THE NW FLOW ALOFT
ON TUES NIGHT INTO WED...WHILE ASSOCIATED SFC LOW SLIDES FROM THE
DAKOTAS TOWARDS THE LOWER GREAT LAKES. BROAD H850-500 WAA...Q-VECTOR
CONV...AND MOISTURE PUSHING IN SLOWLY TUES EVENING AND CONTINUES
THROUGH WED. ECMWF FARTHEST SW WITH THE BEST WAA...WHILE NAM/GFS/GEM
ALL TRY TO FOCUS A STRONGER AREA OF WAA OVER THE NRN CWA ON WED.
THESE DIFFERENCES LEAD TO SOME UNCERTAINTY ON THE EXACT LOCATION OF
THE RAIN. IN ADDITION...DRY AIR BELOW H800 WILL TRY TO LIMIT PCPN
CHANCES THROUGH MUCH OF THE OVERNIGHT HOURS OVER THE FAR WRN CWA.
ATMO DOESN/T REALLY SEEM TO MOISTEN UP UNTIL DAYLIGHT HOURS ON WED.
THIS DELAYED MOISTENING WILL LIMIT PCPN ACROSS THE REST OF THE CWA
FOR THE FIRST PART OF WED. HAVE TRIED TO PUT SOME TIMING IN FOR THIS
DRY AIR HOLDING OFF PCPN. EVEN WITH THE DRY AIR...SEEM TO HAVE
ENOUGH SIGNALS TO BUMP CHANCE POPS UP A LITTLE MORE...ESPECIALLY
OVER THE WRN CWA DURING THE DAY WED. THE INITIAL DRY AIR AND
POSITIONING OF THE PCPN PROVIDES A LITTLE TOO MUCH UNCERTAINTY TO
BUMP THEM UP TO LIKELY VALES.
MUCH STRONGER WAVE AND ASSOCIATED HEIGHT FALLS ARRIVES LATE WED
NIGHT AND THURS MORNING...WHICH BRING THE MUCH COOLER H850 TEMPS TO
THE AREA. THE COLD AIR ON THE BACK SIDE OF THE SYSTEM COULD LEAD TO
LK ENHANCED CLOUDS/PCPN LINGERING BEHIND THE WAVE INTO THURS
MORNING. NAM HOLDING ON TO THE LLVL MOISTURE THROUGH THE MORNING
HOURS BEFORE THE DRIER AIR AND SUBSIDENCE FROM THE HIGH PRESSURE
RIDGE START TO TAKE OVER. WITH THE NRLY FLOW OVER THE AREA DURING
THE MORNING...COMBINING WITH A BRIEF OVERLAP OF THE H850 TEMPS TO
-8C AND MOISTURE...THINK THERE WILL BE A BRIEF PERIOD OF STRONGER
RAIN/SNOW SHOWERS OVER THE NCNTRL UPSLOPE LOCATIONS MAINLY FROM
06-15Z. MAIN CONCERN WITH SNOW IS THAT THE LLVL TEMPS MIGHT NOT GET
COLD ENOUGH TO SUPPORT SNOW UNTIL THE BEST MOISTURE DEPARTS.
THUS...DELAYED THE SNOW CHANGE OVER TO OCCUR LATER IN THE NIGHT AND
DURING THE FIRST PART OF THURS MORNING. SNOW WILL OCCUR A LITTLE
EARLY OVER THE NW HALF OF THE CWA...BUT BOTH CASES WILL NEED A
LITTLE WHILE TO COOL CLOUD TEMPS AND GET ICE CRYSTALS BACK IN THE
CLOUD DUE TO THE DRY H750 AIR ARRIVING WED EVENING.
WITH THE HIGH PRESSURE RIDGE QUICKLY MOVING IN ON THURS AND LLVL
MOISTURE DEPARTING FOR ALL BUT FAR ERN UPPER MI...WILL DECREASE THE
CLOUDS ACROSS THE AREA EVEN THOUGH H850 TEMPS ARE STILL AROUND -6
OR -7C. COULD BE A LITTLE GUSTY WITH THE STRONG PRESSURE GRADIENT
LATE WED NIGHT INTO THURS. WITH THE COLD AIR ARRIVING AND H925
WINDS TO 30KTS...SHOULD SEE GUSTS IN THE 30-35MPH RANGE NEAR LK
SUPERIOR IN THE MORNING AND THEN DIMINISHING FORM WEST TO EAST
THROUGH THE DAY.
&&
FOR THE EXTENDED...
MODELS ARE STILL IN FAIRLY GOOD AGREEMENT IN THE PLACEMENT OF A
MID/UPPER LEVEL RIDGE OVER THE PLAINS THROUGH THE DAY FRIDAY...WITH
THE ASSOCIATED SURFACE HIGH PRESSURE DOMINATING THE UPPER GREAT
LAKES REGION THROUGH SATURDAY. THIS WILL KEEP DRY WEATHER WITH
PREDOMINATE LIGHT N/NERLY WINDS THROUGH THIS TIME PERIOD.
SUNNY/PARTLY CLOUDY SKIES WILL KEEP TEMPERATURES FAIRLY STEADY /AT
OR SLIGHTLY BELOW NORMAL/...WITH COOLEST TEMPERATURES NEAR LAKE
SUPERIOR DUE TO NORTHERLY WINDS OFF THE LAKE.
MODEL CONSENSUS ALSO SHOWS A SHORTWAVE DEVELOPING ON THE BACKSIDE OF
THE RIDGE...HOWEVER DISAGREEMENTS COME IN TO PLAY ON THE PATH THIS
SHORTWAVE WILL TAKE. GFS AND GEM SOLUTIONS HAVE THE SHORTWAVE
DEVELOPING OVER THE PLAINS ON SATURDAY...THEN GETTING PUSHED TO THE
SOUTHEAST UNDER THE INFLUENCE OF THE HIGH PRESSURE RIDGE AND DRY AIR
ALREADY IN PLACE. THIS SOLUTION SEEMS THE MOST REASONABLE. ECMWF
SOLUTION ON THE OTHER HAND CONTINUES TO BE MORE AGGRESSIVE WITH THIS
SYSTEM...MOVING IT NORTHEAST ALONG THE BACKSIDE OF THE RIDGE AND
REACHING THE UPPER GREAT LAKES BY SATURDAY AFTERNOON. WITH THE
GFS/GEM...UPPER MI SHOULD REMAIN DRY. HOWEVER WILL KEEP SLIGHT
CHANCES NEAR THE WI BORDER SATURDAY AFTERNOON...SPREADING FURTHER
INLAND SATURDAY NIGHT AND SUNDAY TO ACCOUNT FOR ECMWF SOLUTION. WITH
THE INCREASE IN CLOUD COVER ASSOCIATED WITH THIS SYSTEM...EXPECT LOW
TEMPERATURES SAT NIGHT TO BE SLIGHTLY WARMER THAN PREVIOUS...BUT
STILL HOVERING ON THE FREEZING LINE...SO SNOW COULD MIX IN WITH RAIN
IN AFFECTED AREAS. PRECIP SHOULD DISSIPATE BY SUNDAY NIGHT AS
SHORTWAVE MOVES TO THE SOUTHEAST AND HIGH PRESSURE BEGINS TO BUILD
IN FROM CANADA THROUGH THE DAY MONDAY.
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 137 PM EDT MON APR 23 2012
THE STRENGTHENING PRESSURE GRADIENT BETWEEN THE RETROGRADING
HIGH...AND ATLANTIC LOW PUSHING ACROSS THE LOWER GREAT LAKES THIS
EVENING WILL RESULT IN INCREASED NW WINDS AT CMX AND ESPECIALLY SAW.
VFR CEILINGS AND VIS SHOULD REMAIN THROUGH THE NEXT 24 HOURS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 414 PM EDT MON APR 23 2012
A STRONG LOW PRESSURE SYSTEM WILL MOVE NNE INTO THE ERN GREAT LAKES
BY THIS EVENING. THIS HAS RESULTED IN INCREASING NNW WINDS...UP TO
30KTS OVER ERN LK SUPERIOR WHICH WILL CONTINUE INTO TUESDAY MORNING.
A LOW PRESSURE SYSTEM WILL MOVE ACROSS THE UPPER LAKES ON WED WHILE
BEFORE STRONG HIGH PRESSURE BUILDS FROM CENTRAL CANADA INTO THE
GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY. THE STRONG GRADIENT
BETWEEN THESE SYSTEMS WILL LEAD TO NORTHERLY GUSTS UP TO 30KTS
OVER CENTRAL AND EASTERN LAKE SUPERIOR WEDNESDAY NIGHT INTO THURSDAY
MORNING. A FEW GALE FORCE GUSTS TO 35KTS ARE ALSO POSSIBLE DURING
THIS TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
RED FLAG WARNING UNTIL 8 PM EDT THIS EVENING FOR MIZ006>008-
013>015-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...SRF
EXTENDED...JMW
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
353 PM EDT MON APR 23 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CONTINUE TO PRODUCE UNSETTLED WEATHER
OVER THE NORTHEAST TODAY THROUGH MID-WEEK AS IT TRACKS NORTHWEST
TOWARD THE EASTERN GREAT LAKES. A SLOT OF DRIER AIR WILL MOVE INTO
THE NORTH COUNTRY...ALLOWING FOR SOME BREAKS IN PRECIPITATION TODAY AND
TONIGHT. THIS SYSTEM WILL MOVE OUT OF THE AREA WEDNESDAY...FOLLOWED
BY A BRIEF PERIOD OF HIGH PRESSURE WEDNESDAY NIGHT. MORE UNSETTLE
WEATHER WILL ARRIVE THURSDAY AS AN UPPER LEVEL TROUGH APPROACHES
THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 106 PM EDT MONDAY...UPDATED TO TWEAK TEMPS BASED ON CRNT OBS
AND DECREASE POPS TO SCHC/CHC ENTIRE CWA...AS WELL DEFINED DRY
SLOT MOVES ACRS OUR REGION. TEMPS WL RANGE FROM NEAR 40F MSS TO
U50S TO NEAR 60F NEAR RUTLAND TODAY. RUC13 HAS BEEN USED TO DEPICT
MAX TEMPS TODAY IN THE GRIDS. REST OF FCST IN GOOD SHAPE.
UPDATED TO REMOVE WIND ADVISORY SLV AND ADJUSTED PRECIP TIMING
BASED ON RADAR. WINDS ACRS THE SLV WL BE 15 TO 25 MPH WITH GUSTS
TO 35 MPH THRU THIS AFTN...BUT WL FALL SHORT OF ADVISORY CRITERIA.
OTHERWISE...AREAS OF LIGHT RAIN/DRIZZLE ESPECIALLY ACRS THE TRRN
WL CONT THRU THIS AFTN...BUT ADDITIONAL QPF WL BE UNDER 0.10".
TEMPS WL BE TRICKY AS STATED BEFORE WITH SOME CLRING DEVELOPING
ACRS THE SOUTHERN CPV AND TEMPS ALREADY AT 52F AT RUTLAND AND 60
AT KDDH. THIS WARMER AIR WL ADVECT NORTH INTO THE EASTERN
CPV/WESTERN SLOPES THIS AFTN. OTHERWISE...COOL NE FLW ACRS THE SLV
WL RESULT IN TEMPS ONLY IN THE U30S TO L40S. ALSO...SOME COOLER
TEMPS ANTICIPATED OVER THE SE UPSLOPE REGIONS OF THE GREENS.
INTERESTING EVENT LAST NIGHT WITH A DUSTING TO 4 INCHES OF SNOW
ACRS THE DACKS WITH SOME ICE ACCUMULATION ON POWERLINES AND TREES.
HAD SEVERAL REPORTS FROM POLICE AND MEDIA OF ISOLATED POWER
OUTAGES AND TREES DOWN DUE TO THE COMBINATION OF SNOW/ICE AND
GUSTY WINDS. SEE LATEST PNSBTV FOR FURTHER DETAILS.
QUICK UPDATE THIS MORNING TO FINE TUNE TIMING OF BACK EDGE OF
STEADIER/HEAVIER PRECIP ENDING ACRS OUR CENTRAL/NORTHERN CWA. CRNT
RADAR SHOWS STEADIER PRECIP ENDING ACRS CENTRAL VT INTO PARTS OF
THE DACKS...WHICH SHOULD CONT TO WORK NORTH TWD THE INTERNATIONAL
BORDER BY NOON. WL USE 100 POPS NORTH TO CHC POPS SOUTH THRU
NOON...THEN MENTION CHC POPS FOR THE REST OF THE DAY. TEMPS WL BE
TRICKY AND HIGHLY DEPEND UPON WINDS AND AMOUNT OF CLRING. VIS SATL
PIC SHOWS SOME BREAKS ACRS SOUTHERN VT ASSOCIATED WITH DRY SLOT
AND DEVELOPING DOWNSLOPE FLOW. THIS WL RESULT IN TEMPS WARMING
ALONG THE WESTERN SLOPES INTO THE 50S TO NEAR 60F...BUT COOL NE
FLW ACRS THE SLV WL KEEP THEM IN THE L/M40S. FOR THE CPV WL
MENTION HIGHS IN THE L/M50S AS WINDS SLOWLY SHIFT TO THE SE...WITH
MAINLY 40S FOR THE MTNS/CENTRAL VT.
HAVE CANCELLED THE WINTER WEATHER ADVISORY FOR THE NORTHERN
ADIRONDACKS AS DRY SLOT CONTINUES TO PROGRESS INTO NORTHERN NEW
YORK AND TEMPERATURES ARE SLOWLY WARMING FROM WARM AIR ADVECTION
ON THE NORTHEAST SIDE OF THE SFC LOW. FEW POCKETS OF RAIN/SNOW
MIX...AND POSSIBLY FREEZING RAIN MAY PERSIST...BUT LITTLE TO NO
ACCUMULATIONS EXPECTED AS TEMPERATURES WARM THIS MORNING.
DOWNSLOPING WINDS ON THE WESTERN SLOPES OF THE GREEN MOUNTAINS
HAS NOT COME TO FRUITION AS WINDS HAVE REMAINED 5 KTS OR LESS.
MODEL GUIDANCE SHOWS THAT THE 850MB JET HAS WEAKENED AND MOVED
NORTH...HAVE THEREFORE CANCELLED THE WIND ADVISORY FOR THAT AREA.
SUMMITS MAY STILL SEE STRONG GUSTS THIS MORNING INTO THE
AFTERNOON. ST. LAWRENCE VALLEY MAY STILL SEE SOME STRONG WIND
GUSTS AS 925MB JET HAS WEAKENED TO 30-45 KTS...BUT REMAINS OVER
THAT AREA THROUGH THE MORNING HOURS. HAVE KEPT THE WIND ADVISORY
OVER THE ST. LAWRENCE VALLEY FOR NOW.
OTHERWISE...PRECIPITATION MOVING INTO SOUTHERN VERMONT AND THE
CHAMPLAIN VALLEY MORE SHOWERY IN NATURE.
PREVIOUS DISCUSSION...ENHANCED CLOUD TOPS AND STRONG RADAR
REFLECTIVITIES OVER ADIRONDACKS IN NORTHERN NEW YORK WELL PROGGED
BY GFS FGEN. NAM SHOWING BEST FGEN MORE EAST...BUT BOTH MODELS
SHOW THIS FEATURE MOVING NORTH OUT OF THE AREA AS IT WEAKENS THIS
MORNING. WINTRY MIX AFFECTING THE NORTHERN ADIRONDACKS WITH
MAINLY SNOW OR RAIN AFFECTING THE ST LAWRENCE VALLEY.
TEMPERATURES GENERALLY WARMER AS YOU HEAD EAST...WITH RAIN
AFFECTING THE CHAMPLAIN VALLEY AND MOST OF VERMONT. TEMPS WILL
GRADUALLY WARM THIS MORNING WITH ANY WINTRY PRECIP CHANGING TO
ALL RAIN DURING THE DAY.
DRY SLOT SLOWLY ADVANCING NORTH FROM EASTERN NY THIS MORNING WILL
LEAD TO FEW BREAKS AND GENERALLY DECREASING POPS OVER THE NORTH
COUNTRY. AS SFC LOW SLOWS NEAR LAKE ONTARIO...NORTHERN NY LIKELY
TO SEE MORE PRECIP TODAY.
TYX RADAR WIND PROFILE SHOWING 40 KTS AT LOWEST LEVELS PERSISTING
EARLY THIS MORNING. LLJ OVER THE ST LAWRENCE VALLEY WEAKENING
DURING THE DAY WITH GUSTS IN THE MORNING OF 30-40 KTS DECREASING
TO LESS THAN 30 KTS THIS AFTERNOON. WIND NOT MIXING DOWN OFF THE
GREENS THIS MORNING WITH 850MB JET PROGGED TO WEAKEN QUICKLY
EARLY TODAY. LLJ ALSO LOOKS TO SHIFT MORE SOUTHERLY
TODAY...LIMITING DOWNSLOPING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 502 AM EDT MONDAY...POTENTIAL FOR GUSTY WINDS EXISTS THROUGH
TUESDAY...BUT LLJ MUCH WEAKER. SFC LOW WILL PIVOT LATE TONIGHT
INTO TUESDAY...BRINGING A SURGE OF PRECIP OVER NORTHERN NY. THIS
WILL ALSO BRING IN COOLER TEMPERATURES...ESPECIALLY ALOFT...WITH
NEGATIVE SINGLE DIGIT TEMPS AT 850MB AND 925MB OVER NORTHERN NY
AND EDGING INTO VERMONT TONIGHT. WITH THESE COOLER TEMPS...CAN
EXPECT GREATER CHANCE FOR ANY PRECIP OVERNIGHT TO BE RAIN/SNOW MIX
TO ALL SNOW OVER THE ADIRONDACKS. SNOWFALL AMOUNTS OVERNIGHT WILL
RANGE FROM A DUSTING TO LESS THAN ONE INCH. THE COOLER AIR ALOFT
WILL LEAD TO COOLER MAX TEMPS ON TUESDAY...WITH HIGHS IN THE 40S
TO LOW 50S.
THE FAIRLY STACKED LOW WILL GAIN MOMENTUM NORTHWARD LATE TUESDAY
AND TUESDAY NIGHT WITH DECREASING CHANCES FOR PRECIP AS THE
DAY/NIGHT GO ON. THERES STILL A CHANCE FOR SNOW SHOWERS TUESDAY
NIGHT MAINLY OVER THE HIGHER TERRAIN WITH LESS THAN ONE INCH
ACCUMULATION EXPECTED AT THIS TIME.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 340 PM EDT MONDAY...COOL AND MOSTLY WET PATTERN ON TAP FOR
THE EXTENDED PERIOD. THIS WILL BE SET UP BY BROAD UPPER LOW
PRESSURE SYSTEM THAT WILL REMAIN OVER EASTERN CANADA. FIRST SYSTEM
WILL PIVOT AROUND UPPER LOW THURSDAY AS IS PUSHES THRU THE GREAT
LKS REGION...THEN THRU THE REGION BY FRIDAY. NNW FLOW BEHIND THIS
EXITING SYSTEM WILL KEEP CHANCE FOR LGT PRECIP OVER NORTHERN ZONES
THRU FRIDAY...BFR WK RIDGE BUILDS OVER AREA FOR SATURDAY. ANOTHER
LOW COMING ACROSS THE CENTRAL PLAINS LATE SATURDAY WILL GET CAUGHT
IN THE UPPER LOW CIRCULATION. MDLS DO DIFFER AS TO EXTENT OF
PRECIP COMING INTO CWA...WITH ECMWF SWINGING THIS SYSTEM JUST
SOUTH OF THE REGION...WHILE THE GFS SWINGS PRECIP THRU...AIDED BY
DEVELOPMENT OF MIDLEVEL CUTOFF LEVEL. WILL SPLIT DIFFERENCE OF
THESE TWO W/ BULK OF PRECIP STAYING SOUTH. HIGHEST POPS OVER
SOUTHERN ZONES. W/ CWA UNDER BROAD NW FLOW DURING THIS TIME...NOT
EXPECTING MAJOR SWINGS IN TEMPS DURING THE DAYTIME HRS...AND WILL
KEEP CLOSE TO MDL GUIDANCE IN THE 50S W/ SOME 40S IN THE HILLS OF
DACKS/NE VT. FOR OVERNGT LOWS...CD AIR INTRUSION WILL ALLOW FOR
MIX WITH/CHANGE TO -SW ESPECIALLY OVER HIR TRRN...W/ LITTLE ACCUM.
GOING FOR 30S IN VALLEYS AND 20S IN THE DACKS/GREEN MTNS.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
THROUGH 18Z TUESDAY...LOW PRESSURE SYSTEM MVG WNW THRU NY ATTM
WILL ALLOW FOR BREAKS IN CLD COVER THRU 00Z TUESDAY. LOOKING FOR
MAINLY A MIX OF MVFR TO LIFR SKY COND DURING THIS TIME WITH
CEILINGS DIPPING DOWN TO BLW OVC010. GRADUAL INCR OF CEILINGS
OVERNGT THRU 18Z TUESDAY AS WINDS SHIFT WITH LOW OVER SOUTHERN
ONTARIO. MAINLY IFR/MVFR CEILINGS WITH SOME VFR AFT 13Z TUESDAY.
PRECIP POSSIBLE DUE TO LOW CEILINGS. BEST CHANCES IN MSS/SLK WHERE
RW/SW POSSIBLE. SOME FG FORMATION OVERNGT HAMPERED OVERALL BY
STRONG WINDS SHIFTING FROM MAINLY NNE TO SSW 10-20KTS...WITH GUSTS
TO 25KTS AFT 14Z.
OUTLOOK 18Z TUESDAY THROUGH SATURDAY...
18Z TUESDAY THROUGH 00Z THURSDAY...VFR WITH PERIODS OF MVFR/IFR IN
SCATTERED RAIN/SNOW SHOWERS WITH UPPER LEVEL LOW...ESPECIALLY AT
SLK/MPV.
00Z THURSDAY THROUGH 12Z THURSDAY...PRIMARILY VFR BETWEEN
STORM SYSTEMS.
12Z THURSDAY THROUGH SATURDAY...VFR WITH PERIODS OF MVFR/IFR IN
RAIN/SNOW SHOWERS WITH FRONTAL SYSTEM...ESPECIALLY SLK/MPV.
&&
.MARINE...
AS OF 350 PM EDT MONDAY...A LAKE WIND ADVISORY WILL GO INTO EFFECT
AFTER MIDNIGHT TONIGHT. NORTH WINDS THIS AFTERNOON AND EVENING
FROM 5 TO 15 KNOTS WILL TURN SOUTHERLY OVERNIGHT AND INCREASE TO
15 TO 25 KNOTS LATE TONIGHT. THE ADVISORY WILL LIKELY NEED TO BE
CONTINUED THROUGH TUESDAY AS WINDS ARE EXPECTED TO INCREASE
FURTHER TO 20 TO 30 KNOTS. WAVES OF 1 TO 3 FEET TONIGHT WILL
BUILD TO 2 TO 4 FEET ON TUESDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KM
NEAR TERM...KM/TABER
SHORT TERM...KM
LONG TERM...JN
AVIATION...JN/SLW
MARINE...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
340 PM EDT MON APR 23 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CONTINUE TO PRODUCE UNSETTLED WEATHER
OVER THE NORTHEAST TODAY THROUGH MID-WEEK AS IT TRACKS NORTHWEST
TOWARD THE EASTERN GREAT LAKES. A SLOT OF DRIER AIR WILL MOVE INTO
THE NORTH COUNTRY...ALLOWING FOR SOME BREAKS IN PRECIPITATION TODAY AND
TONIGHT. THIS SYSTEM WILL MOVE OUT OF THE AREA WEDNESDAY...FOLLOWED
BY A BRIEF PERIOD OF HIGH PRESSURE WEDNESDAY NIGHT. MORE UNSETTLE
WEATHER WILL ARRIVE THURSDAY AS AN UPPER LEVEL TROUGH APPROACHES
THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 106 PM EDT MONDAY...UPDATED TO TWEAK TEMPS BASED ON CRNT OBS
AND DECREASE POPS TO SCHC/CHC ENTIRE CWA...AS WELL DEFINED DRY
SLOT MOVES ACRS OUR REGION. TEMPS WL RANGE FROM NEAR 40F MSS TO
U50S TO NEAR 60F NEAR RUTLAND TODAY. RUC13 HAS BEEN USED TO DEPICT
MAX TEMPS TODAY IN THE GRIDS. REST OF FCST IN GOOD SHAPE.
UPDATED TO REMOVE WIND ADVISORY SLV AND ADJUSTED PRECIP TIMING
BASED ON RADAR. WINDS ACRS THE SLV WL BE 15 TO 25 MPH WITH GUSTS
TO 35 MPH THRU THIS AFTN...BUT WL FALL SHORT OF ADVISORY CRITERIA.
OTHERWISE...AREAS OF LIGHT RAIN/DRIZZLE ESPECIALLY ACRS THE TRRN
WL CONT THRU THIS AFTN...BUT ADDITIONAL QPF WL BE UNDER 0.10".
TEMPS WL BE TRICKY AS STATED BEFORE WITH SOME CLRING DEVELOPING
ACRS THE SOUTHERN CPV AND TEMPS ALREADY AT 52F AT RUTLAND AND 60
AT KDDH. THIS WARMER AIR WL ADVECT NORTH INTO THE EASTERN
CPV/WESTERN SLOPES THIS AFTN. OTHERWISE...COOL NE FLW ACRS THE SLV
WL RESULT IN TEMPS ONLY IN THE U30S TO L40S. ALSO...SOME COOLER
TEMPS ANTICIPATED OVER THE SE UPSLOPE REGIONS OF THE GREENS.
INTERESTING EVENT LAST NIGHT WITH A DUSTING TO 4 INCHES OF SNOW
ACRS THE DACKS WITH SOME ICE ACCUMULATION ON POWERLINES AND TREES.
HAD SEVERAL REPORTS FROM POLICE AND MEDIA OF ISOLATED POWER
OUTAGES AND TREES DOWN DUE TO THE COMBINATION OF SNOW/ICE AND
GUSTY WINDS. SEE LATEST PNSBTV FOR FURTHER DETAILS.
QUICK UPDATE THIS MORNING TO FINE TUNE TIMING OF BACK EDGE OF
STEADIER/HEAVIER PRECIP ENDING ACRS OUR CENTRAL/NORTHERN CWA. CRNT
RADAR SHOWS STEADIER PRECIP ENDING ACRS CENTRAL VT INTO PARTS OF
THE DACKS...WHICH SHOULD CONT TO WORK NORTH TWD THE INTERNATIONAL
BORDER BY NOON. WL USE 100 POPS NORTH TO CHC POPS SOUTH THRU
NOON...THEN MENTION CHC POPS FOR THE REST OF THE DAY. TEMPS WL BE
TRICKY AND HIGHLY DEPEND UPON WINDS AND AMOUNT OF CLRING. VIS SATL
PIC SHOWS SOME BREAKS ACRS SOUTHERN VT ASSOCIATED WITH DRY SLOT
AND DEVELOPING DOWNSLOPE FLOW. THIS WL RESULT IN TEMPS WARMING
ALONG THE WESTERN SLOPES INTO THE 50S TO NEAR 60F...BUT COOL NE
FLW ACRS THE SLV WL KEEP THEM IN THE L/M40S. FOR THE CPV WL
MENTION HIGHS IN THE L/M50S AS WINDS SLOWLY SHIFT TO THE SE...WITH
MAINLY 40S FOR THE MTNS/CENTRAL VT.
HAVE CANCELLED THE WINTER WEATHER ADVISORY FOR THE NORTHERN
ADIRONDACKS AS DRY SLOT CONTINUES TO PROGRESS INTO NORTHERN NEW
YORK AND TEMPERATURES ARE SLOWLY WARMING FROM WARM AIR ADVECTION
ON THE NORTHEAST SIDE OF THE SFC LOW. FEW POCKETS OF RAIN/SNOW
MIX...AND POSSIBLY FREEZING RAIN MAY PERSIST...BUT LITTLE TO NO
ACCUMULATIONS EXPECTED AS TEMPERATURES WARM THIS MORNING.
DOWNSLOPING WINDS ON THE WESTERN SLOPES OF THE GREEN MOUNTAINS
HAS NOT COME TO FRUITION AS WINDS HAVE REMAINED 5 KTS OR LESS.
MODEL GUIDANCE SHOWS THAT THE 850MB JET HAS WEAKENED AND MOVED
NORTH...HAVE THEREFORE CANCELLED THE WIND ADVISORY FOR THAT AREA.
SUMMITS MAY STILL SEE STRONG GUSTS THIS MORNING INTO THE
AFTERNOON. ST. LAWRENCE VALLEY MAY STILL SEE SOME STRONG WIND
GUSTS AS 925MB JET HAS WEAKENED TO 30-45 KTS...BUT REMAINS OVER
THAT AREA THROUGH THE MORNING HOURS. HAVE KEPT THE WIND ADVISORY
OVER THE ST. LAWRENCE VALLEY FOR NOW.
OTHERWISE...PRECIPITATION MOVING INTO SOUTHERN VERMONT AND THE
CHAMPLAIN VALLEY MORE SHOWERY IN NATURE.
PREVIOUS DISCUSSION...ENHANCED CLOUD TOPS AND STRONG RADAR
REFLECTIVITIES OVER ADIRONDACKS IN NORTHERN NEW YORK WELL PROGGED
BY GFS FGEN. NAM SHOWING BEST FGEN MORE EAST...BUT BOTH MODELS
SHOW THIS FEATURE MOVING NORTH OUT OF THE AREA AS IT WEAKENS THIS
MORNING. WINTRY MIX AFFECTING THE NORTHERN ADIRONDACKS WITH
MAINLY SNOW OR RAIN AFFECTING THE ST LAWRENCE VALLEY.
TEMPERATURES GENERALLY WARMER AS YOU HEAD EAST...WITH RAIN
AFFECTING THE CHAMPLAIN VALLEY AND MOST OF VERMONT. TEMPS WILL
GRADUALLY WARM THIS MORNING WITH ANY WINTRY PRECIP CHANGING TO
ALL RAIN DURING THE DAY.
DRY SLOT SLOWLY ADVANCING NORTH FROM EASTERN NY THIS MORNING WILL
LEAD TO FEW BREAKS AND GENERALLY DECREASING POPS OVER THE NORTH
COUNTRY. AS SFC LOW SLOWS NEAR LAKE ONTARIO...NORTHERN NY LIKELY
TO SEE MORE PRECIP TODAY.
TYX RADAR WIND PROFILE SHOWING 40 KTS AT LOWEST LEVELS PERSISTING
EARLY THIS MORNING. LLJ OVER THE ST LAWRENCE VALLEY WEAKENING
DURING THE DAY WITH GUSTS IN THE MORNING OF 30-40 KTS DECREASING
TO LESS THAN 30 KTS THIS AFTERNOON. WIND NOT MIXING DOWN OFF THE
GREENS THIS MORNING WITH 850MB JET PROGGED TO WEAKEN QUICKLY
EARLY TODAY. LLJ ALSO LOOKS TO SHIFT MORE SOUTHERLY
TODAY...LIMITING DOWNSLOPING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
AS OF 502 AM EDT MONDAY...POTENTIAL FOR GUSTY WINDS EXISTS THROUGH
TUESDAY...BUT LLJ MUCH WEAKER. SFC LOW WILL PIVOT LATE TONIGHT
INTO TUESDAY...BRINGING A SURGE OF PRECIP OVER NORTHERN NY. THIS
WILL ALSO BRING IN COOLER TEMPERATURES...ESPECIALLY ALOFT...WITH
NEGATIVE SINGLE DIGIT TEMPS AT 850MB AND 925MB OVER NORTHERN NY
AND EDGING INTO VERMONT TONIGHT. WITH THESE COOLER TEMPS...CAN
EXPECT GREATER CHANCE FOR ANY PRECIP OVERNIGHT TO BE RAIN/SNOW MIX
TO ALL SNOW OVER THE ADIRONDACKS. SNOWFALL AMOUNTS OVERNIGHT WILL
RANGE FROM A DUSTING TO LESS THAN ONE INCH. THE COOLER AIR ALOFT
WILL LEAD TO COOLER MAX TEMPS ON TUESDAY...WITH HIGHS IN THE 40S
TO LOW 50S.
THE FAIRLY STACKED LOW WILL GAIN MOMENTUM NORTHWARD LATE TUESDAY
AND TUESDAY NIGHT WITH DECREASING CHANCES FOR PRECIP AS THE
DAY/NIGHT GO ON. THERES STILL A CHANCE FOR SNOW SHOWERS TUESDAY
NIGHT MAINLY OVER THE HIGHER TERRAIN WITH LESS THAN ONE INCH
ACCUMULATION EXPECTED AT THIS TIME.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 340 PM EDT MONDAY...COOL AND MOSTLY WET PATTERN ON TAP FOR
THE EXTENDED PERIOD. THIS WILL BE SET UP BY BROAD UPPER LOW
PRESSURE SYSTEM THAT WILL REMAIN OVER EASTERN CANADA. FIRST SYSTEM
WILL PIVOT AROUND UPPER LOW THURSDAY AS IS PUSHES THRU THE GREAT
LKS REGION...THEN THRU THE REGION BY FRIDAY. NNW FLOW BEHIND THIS
EXITING SYSTEM WILL KEEP CHANCE FOR LGT PRECIP OVER NORTHERN ZONES
THRU FRIDAY...BFR WK RIDGE BUILDS OVER AREA FOR SATURDAY. ANOTHER
LOW COMING ACROSS THE CENTRAL PLAINS LATE SATURDAY WILL GET CAUGHT
IN THE UPPER LOW CIRCULATION. MDLS DO DIFFER AS TO EXTENT OF
PRECIP COMING INTO CWA...WITH ECMWF SWINGING THIS SYSTEM JUST
SOUTH OF THE REGION...WHILE THE GFS SWINGS PRECIP THRU...AIDED BY
DEVELOPMENT OF MIDLEVEL CUTOFF LEVEL. WILL SPLIT DIFFERENCE OF
THESE TWO W/ BULK OF PRECIP STAYING SOUTH. HIGHEST POPS OVER
SOUTHERN ZONES. W/ CWA UNDER BROAD NW FLOW DURING THIS TIME...NOT
EXPECTING MAJOR SWINGS IN TEMPS DURING THE DAYTIME HRS...AND WILL
KEEP CLOSE TO MDL GUIDANCE IN THE 50S W/ SOME 40S IN THE HILLS OF
DACKS/NE VT. FOR OVERNGT LOWS...CD AIR INTRUSION WILL ALLOW FOR
MIX WITH/CHANGE TO -SW ESPECIALLY OVER HIR TRRN...W/ LITTLE ACCUM.
GOING FOR 30S IN VALLEYS AND 20S IN THE DACKS/GREEN MTNS.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
THROUGH 18Z TUESDAY...LOW PRESSURE SYSTEM MVG WNW THRU NY ATTM
WILL ALLOW FOR BREAKS IN CLD COVER THRU 00Z TUESDAY. LOOKING FOR
MAINLY A MIX OF MVFR TO LIFR SKY COND DURING THIS TIME WITH
CEILINGS DIPPING DOWN TO BLW OVC010. GRADUAL INCR OF CEILINGS
OVERNGT THRU 18Z TUESDAY AS WINDS SHIFT WITH LOW OVER SOUTHERN
ONTARIO. MAINLY IFR/MVFR CEILINGS WITH SOME VFR AFT 13Z TUESDAY.
PRECIP POSSIBLE DUE TO LOW CEILINGS. BEST CHANCES IN MSS/SLK WHERE
RW/SW POSSIBLE. SOME FG FORMATION OVERNGT HAMPERED OVERALL BY
STRONG WINDS SHIFTING FROM MAINLY NNE TO SSW 10-20KTS...WITH GUSTS
TO 25KTS AFT 14Z.
OUTLOOK 18Z TUESDAY THROUGH SATURDAY...
18Z TUESDAY THROUGH 00Z THURSDAY...VFR WITH PERIODS OF MVFR/IFR IN
SCATTERED RAIN/SNOW SHOWERS WITH UPPER LEVEL LOW...ESPECIALLY AT
SLK/MPV.
00Z THURSDAY THROUGH 12Z THURSDAY...PRIMARILY VFR BETWEEN
STORM SYSTEMS.
12Z THURSDAY THROUGH SATURDAY...VFR WITH PERIODS OF MVFR/IFR IN
RAIN/SNOW SHOWERS WITH FRONTAL SYSTEM...ESPECIALLY SLK/MPV.
&&
.MARINE...
AS OF 445 AM EDT MONDAY...LAKE WIND ADVISORY IS IN EFFECT FOR
TODAY...ESPECIALLY THE MORNING.
NORTH WINDS OF 15 TO 25 WILL CONTINUE THROUGH MID-MORNING BEFORE
DECREASING TO 10 KNOTS THIS AFTERNOON.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KM
NEAR TERM...KM/TABER
SHORT TERM...KM
LONG TERM...JN
AVIATION...JN/SLW
MARINE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
136 PM EDT MON APR 23 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CONTINUE TO PRODUCE UNSETTLED WEATHER
OVER THE NORTHEAST TODAY THROUGH MID-WEEK AS IT TRACKS NORTHWEST
TOWARD THE EASTERN GREAT LAKES. A SLOT OF DRIER AIR WILL MOVE INTO
THE NORTH COUNTRY...ALLOWING FOR SOME BREAKS IN PRECIPITATION TODAY AND
TONIGHT. THIS SYSTEM WILL MOVE OUT OF THE AREA WEDNESDAY...FOLLOWED
BY A BRIEF PERIOD OF HIGH PRESSURE WEDNESDAY NIGHT. MORE UNSETTLE
WEATHER WILL ARRIVE THURSDAY AS AN UPPER LEVEL TROUGH APPROACHES
THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 106 PM EDT MONDAY...UPDATED TO TWEAK TEMPS BASED ON CRNT OBS
AND DECREASE POPS TO SCHC/CHC ENTIRE CWA...AS WELL DEFINED DRY
SLOT MOVES ACRS OUR REGION. TEMPS WL RANGE FROM NEAR 40F MSS TO
U50S TO NEAR 60F NEAR RUTLAND TODAY. RUC13 HAS BEEN USED TO DEPICT
MAX TEMPS TODAY IN THE GRIDS. REST OF FCST IN GOOD SHAPE.
UPDATED TO REMOVE WIND ADVISORY SLV AND ADJUSTED PRECIP TIMING
BASED ON RADAR. WINDS ACRS THE SLV WL BE 15 TO 25 MPH WITH GUSTS
TO 35 MPH THRU THIS AFTN...BUT WL FALL SHORT OF ADVISORY CRITERIA.
OTHERWISE...AREAS OF LIGHT RAIN/DRIZZLE ESPECIALLY ACRS THE TRRN
WL CONT THRU THIS AFTN...BUT ADDITIONAL QPF WL BE UNDER 0.10".
TEMPS WL BE TRICKY AS STATED BEFORE WITH SOME CLRING DEVELOPING
ACRS THE SOUTHERN CPV AND TEMPS ALREADY AT 52F AT RUTLAND AND 60
AT KDDH. THIS WARMER AIR WL ADVECT NORTH INTO THE EASTERN
CPV/WESTERN SLOPES THIS AFTN. OTHERWISE...COOL NE FLW ACRS THE SLV
WL RESULT IN TEMPS ONLY IN THE U30S TO L40S. ALSO...SOME COOLER
TEMPS ANTICIPATED OVER THE SE UPSLOPE REGIONS OF THE GREENS.
INTERESTING EVENT LAST NIGHT WITH A DUSTING TO 4 INCHES OF SNOW
ACRS THE DACKS WITH SOME ICE ACCUMULATION ON POWERLINES AND TREES.
HAD SEVERAL REPORTS FROM POLICE AND MEDIA OF ISOLATED POWER
OUTAGES AND TREES DOWN DUE TO THE COMBINATION OF SNOW/ICE AND
GUSTY WINDS. SEE LATEST PNSBTV FOR FURTHER DETAILS.
QUICK UPDATE THIS MORNING TO FINE TUNE TIMING OF BACK EDGE OF
STEADIER/HEAVIER PRECIP ENDING ACRS OUR CENTRAL/NORTHERN CWA. CRNT
RADAR SHOWS STEADIER PRECIP ENDING ACRS CENTRAL VT INTO PARTS OF
THE DACKS...WHICH SHOULD CONT TO WORK NORTH TWD THE INTERNATIONAL
BORDER BY NOON. WL USE 100 POPS NORTH TO CHC POPS SOUTH THRU
NOON...THEN MENTION CHC POPS FOR THE REST OF THE DAY. TEMPS WL BE
TRICKY AND HIGHLY DEPEND UPON WINDS AND AMOUNT OF CLRING. VIS SATL
PIC SHOWS SOME BREAKS ACRS SOUTHERN VT ASSOCIATED WITH DRY SLOT
AND DEVELOPING DOWNSLOPE FLOW. THIS WL RESULT IN TEMPS WARMING
ALONG THE WESTERN SLOPES INTO THE 50S TO NEAR 60F...BUT COOL NE
FLW ACRS THE SLV WL KEEP THEM IN THE L/M40S. FOR THE CPV WL
MENTION HIGHS IN THE L/M50S AS WINDS SLOWLY SHIFT TO THE SE...WITH
MAINLY 40S FOR THE MTNS/CENTRAL VT.
HAVE CANCELLED THE WINTER WEATHER ADVISORY FOR THE NORTHERN
ADIRONDACKS AS DRY SLOT CONTINUES TO PROGRESS INTO NORTHERN NEW
YORK AND TEMPERATURES ARE SLOWLY WARMING FROM WARM AIR ADVECTION
ON THE NORTHEAST SIDE OF THE SFC LOW. FEW POCKETS OF RAIN/SNOW
MIX...AND POSSIBLY FREEZING RAIN MAY PERSIST...BUT LITTLE TO NO
ACCUMULATIONS EXPECTED AS TEMPERATURES WARM THIS MORNING.
DOWNSLOPING WINDS ON THE WESTERN SLOPES OF THE GREEN MOUNTAINS
HAS NOT COME TO FRUITION AS WINDS HAVE REMAINED 5 KTS OR LESS.
MODEL GUIDANCE SHOWS THAT THE 850MB JET HAS WEAKENED AND MOVED
NORTH...HAVE THEREFORE CANCELLED THE WIND ADVISORY FOR THAT AREA.
SUMMITS MAY STILL SEE STRONG GUSTS THIS MORNING INTO THE
AFTERNOON. ST. LAWRENCE VALLEY MAY STILL SEE SOME STRONG WIND
GUSTS AS 925MB JET HAS WEAKENED TO 30-45 KTS...BUT REMAINS OVER
THAT AREA THROUGH THE MORNING HOURS. HAVE KEPT THE WIND ADVISORY
OVER THE ST. LAWRENCE VALLEY FOR NOW.
OTHERWISE...PRECIPITATION MOVING INTO SOUTHERN VERMONT AND THE
CHAMPLAIN VALLEY MORE SHOWERY IN NATURE.
PREVIOUS DISCUSSION...ENHANCED CLOUD TOPS AND STRONG RADAR
REFLECTIVITIES OVER ADIRONDACKS IN NORTHERN NEW YORK WELL PROGGED
BY GFS FGEN. NAM SHOWING BEST FGEN MORE EAST...BUT BOTH MODELS
SHOW THIS FEATURE MOVING NORTH OUT OF THE AREA AS IT WEAKENS THIS
MORNING. WINTRY MIX AFFECTING THE NORTHERN ADIRONDACKS WITH
MAINLY SNOW OR RAIN AFFECTING THE ST LAWRENCE VALLEY.
TEMPERATURES GENERALLY WARMER AS YOU HEAD EAST...WITH RAIN
AFFECTING THE CHAMPLAIN VALLEY AND MOST OF VERMONT. TEMPS WILL
GRADUALLY WARM THIS MORNING WITH ANY WINTRY PRECIP CHANGING TO
ALL RAIN DURING THE DAY.
DRY SLOT SLOWLY ADVANCING NORTH FROM EASTERN NY THIS MORNING WILL
LEAD TO FEW BREAKS AND GENERALLY DECREASING POPS OVER THE NORTH
COUNTRY. AS SFC LOW SLOWS NEAR LAKE ONTARIO...NORTHERN NY LIKELY
TO SEE MORE PRECIP TODAY.
TYX RADAR WIND PROFILE SHOWING 40 KTS AT LOWEST LEVELS PERSISTING
EARLY THIS MORNING. LLJ OVER THE ST LAWRENCE VALLEY WEAKENING
DURING THE DAY WITH GUSTS IN THE MORNING OF 30-40 KTS DECREASING
TO LESS THAN 30 KTS THIS AFTERNOON. WIND NOT MIXING DOWN OFF THE
GREENS THIS MORNING WITH 850MB JET PROGGED TO WEAKEN QUICKLY
EARLY TODAY. LLJ ALSO LOOKS TO SHIFT MORE SOUTHERLY
TODAY...LIMITING DOWNSLOPING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
AS OF 502 AM EDT MONDAY...POTENTIAL FOR GUSTY WINDS EXISTS THROUGH
TUESDAY...BUT LLJ MUCH WEAKER. SFC LOW WILL PIVOT LATE TONIGHT
INTO TUESDAY...BRINGING A SURGE OF PRECIP OVER NORTHERN NY. THIS
WILL ALSO BRING IN COOLER TEMPERATURES...ESPECIALLY ALOFT...WITH
NEGATIVE SINGLE DIGIT TEMPS AT 850MB AND 925MB OVER NORTHERN NY
AND EDGING INTO VERMONT TONIGHT. WITH THESE COOLER TEMPS...CAN
EXPECT GREATER CHANCE FOR ANY PRECIP OVERNIGHT TO BE RAIN/SNOW MIX
TO ALL SNOW OVER THE ADIRONDACKS. SNOWFALL AMOUNTS OVERNIGHT WILL
RANGE FROM A DUSTING TO LESS THAN ONE INCH. THE COOLER AIR ALOFT
WILL LEAD TO COOLER MAX TEMPS ON TUESDAY...WITH HIGHS IN THE 40S
TO LOW 50S.
THE FAIRLY STACKED LOW WILL GAIN MOMENTUM NORTHWARD LATE TUESDAY
AND TUESDAY NIGHT WITH DECREASING CHANCES FOR PRECIP AS THE
DAY/NIGHT GO ON. THERES STILL A CHANCE FOR SNOW SHOWERS TUESDAY
NIGHT MAINLY OVER THE HIGHER TERRAIN WITH LESS THAN ONE INCH
ACCUMULATION EXPECTED AT THIS TIME.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 434 AM EDT MONDAY...SIMILAR TO THINKING SUNDAY AT THIS
TIME...MONDAY/S CLOSED SYSTEM WEAKENING AND BECOMING ABSORBED BY
CLOSED LOW IN JAMES BAY BUT WILL EVENTUALLY RETURN IN A DIFFERENT
FASHION LATER THIS WEEK AND EARLY NEXT WEEKEND. WINTER IN LATE
APRIL AFTER SUMMER IN MID-MARCH...GO FIGURE?!
AGAIN...TROFINESS HANGS ON WED WITH LESSENING CHC OF -SHRA EACH
MOMENT. OVERALL FLOW PATTERN STILL NW AND CYCLONIC BACKING
TOWARD W AND SW AHEAD OF NEXT STG S/W ROTATING ARD HUDSON BAY CLOSED
LOW WHICH WILL BRING A SERIES OF COLD FRONTS AND -SHRA THREAT ON
THU/THU NGT AND PSBLY FRI. THERE/S BEEN A ONGOING CHANGE HERE...
ALL MODELS ARE COMING INTO PHASE OF A STG NRN STREAM S/W ROTATING
INTO FA WITH SFC LOW DEVELOPMENT THU AFTN-FRI WHICH WILL BRING MORE
OF A STEADY PCPN VS SHOWERY WITH PERHAPS SOME SNOW AS WELL.
THEREAFTER...COLD NNW FLOW AND SFC HIGH DIRECTLY FM POLAR REGIONS
MOVES INTO FA FOR SAT/SUN. MIN/MAX TEMPS FOR FRI/SAT ARE FCST 10+
DEGS BLO NORMAL (DAYS 6/7) WHICH MEANS CUD BE COLDER.
THERE ARE STILL QUESTIONS FOR SUNDAY AS A LEFTOVER BOUNDARY FM
THU/FRI SYSTEM LIES JUST S OF SNE WITH ANOTHER NRN STREAM S/W
ROTATING SE TOWARD GRT LAKES AND POSSIBLE SFC LOW DVLPMNT ALG THIS
BOUNDARY WITH A THREAT OF RAIN ACRS SRN FA.
FROST/FREEZE PROGRAM BEGINS IN CHAMPL VLY/ST LWRNC VLY APRIL
25TH...APPROX 10 DAYS EARLY DUE TO ABNORMALLY WARM WINTER/SPRING AND
HORTICULUTURE SEASON RUNNING WEEKS EARLY.
BEGINNING/ENDING FROST/FREEZE PROGRAM IS ALWAYS PROBLEMATIC DUE TO
DIFFERENT CLIMATE REGIONS ACROSS CWA. IT WILL ACTUALLY BE COLDER IN
INTERIOR VERMONT AND NORTHERN NY YET DUE TO THE START OF THE PROGRAM
BEING MAY 5TH AND MAY 15TH THERE WUD BE NO HEADLINES.
HEADLINES OR NOT...IF TEMPERATURES GET INTO THE 20S/L30S PROTECTION
OF ANY CROPS/PLANTS NEED TO BE TAKEN. APPLE ORCHARDS AND WINE
VINEYARDS ARE AT A SUSCEPTIBLE POINT WITH TEMPS IN THE M20S POSSIBLY
CAUSING DEVASTATING EFFECTS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
THROUGH 18Z TUESDAY...LOW PRESSURE SYSTEM MVG WNW THRU NY ATTM
WILL ALLOW FOR BREAKS IN CLD COVER THRU 00Z TUESDAY. LOOKING FOR
MAINLY A MIX OF MVFR TO LIFR SKY COND DURING THIS TIME WITH
CEILINGS DIPPING DOWN TO BLW OVC010. GRADUAL INCR OF CEILINGS
OVERNGT THRU 18Z TUESDAY AS WINDS SHIFT WITH LOW OVER SOUTHERN
ONTARIO. MAINLY IFR/MVFR CEILINGS WITH SOME VFR AFT 13Z TUESDAY.
PRECIP POSSIBLE DUE TO LOW CEILINGS. BEST CHANCES IN MSS/SLK WHERE
RW/SW POSSIBLE. SOME FG FORMATION OVERNGT HAMPERED OVERALL BY
STRONG WINDS SHIFTING FROM MAINLY NNE TO SSW 10-20KTS...WITH GUSTS
TO 25KTS AFT 14Z.
OUTLOOK 18Z TUESDAY THROUGH SATURDAY...
18Z TUESDAY THROUGH 00Z THURSDAY...VFR WITH PERIODS OF MVFR/IFR IN
SCATTERED RAIN/SNOW SHOWERS WITH UPPER LEVEL LOW...ESPECIALLY AT
SLK/MPV.
00Z THURSDAY THROUGH 12Z THURSDAY...PRIMARILY VFR BETWEEN
STORM SYSTEMS.
12Z THURSDAY THROUGH SATURDAY...VFR WITH PERIODS OF MVFR/IFR IN
RAIN/SNOW SHOWERS WITH FRONTAL SYSTEM...ESPECIALLY SLK/MPV.
&&
.MARINE...
AS OF 445 AM EDT MONDAY...LAKE WIND ADVISORY IS IN EFFECT FOR
TODAY...ESPECIALLY THE MORNING.
NORTH WINDS OF 15 TO 25 WILL CONTINUE THROUGH MID-MORNING BEFORE
DECREASING TO 10 KNOTS THIS AFTERNOON.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KM
NEAR TERM...KM/TABER
SHORT TERM...KM
LONG TERM...SLW
AVIATION...JN/SLW
MARINE...NWS BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
109 PM EDT MON APR 23 2012
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CONTINUE TO PRODUCE UNSETTLED WEATHER
OVER THE NORTHEAST TODAY THROUGH MID-WEEK AS IT TRACKS NORTHWEST
TOWARD THE EASTERN GREAT LAKES. A SLOT OF DRIER AIR WILL MOVE INTO
THE NORTH COUNTRY...ALLOWING FOR SOME BREAKS IN PRECIPITATION TODAY AND
TONIGHT. THIS SYSTEM WILL MOVE OUT OF THE AREA WEDNESDAY...FOLLOWED
BY A BRIEF PERIOD OF HIGH PRESSURE WEDNESDAY NIGHT. MORE UNSETTLE
WEATHER WILL ARRIVE THURSDAY AS AN UPPER LEVEL TROUGH APPROACHES
THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 106 PM EDT MONDAY...UPDATED TO TWEAK TEMPS BASED ON CRNT OBS
AND DECREASE POPS TO SCHC/CHC ENTIRE CWA...AS WELL DEFINED DRY
SLOT MOVES ACRS OUR REGION. TEMPS WL RANGE FROM NEAR 40F MSS TO
U50S TO NEAR 60F NEAR RUTLAND TODAY. RUC13 HAS BEEN USED TO DEPICT
MAX TEMPS TODAY IN THE GRIDS. REST OF FCST IN GOOD SHAPE.
UPDATED TO REMOVE WIND ADVISORY SLV AND ADJUSTED PRECIP TIMING
BASED ON RADAR. WINDS ACRS THE SLV WL BE 15 TO 25 MPH WITH GUSTS
TO 35 MPH THRU THIS AFTN...BUT WL FALL SHORT OF ADVISORY CRITERIA.
OTHERWISE...AREAS OF LIGHT RAIN/DRIZZLE ESPECIALLY ACRS THE TRRN
WL CONT THRU THIS AFTN...BUT ADDITIONAL QPF WL BE UNDER 0.10".
TEMPS WL BE TRICKY AS STATED BEFORE WITH SOME CLRING DEVELOPING
ACRS THE SOUTHERN CPV AND TEMPS ALREADY AT 52F AT RUTLAND AND 60
AT KDDH. THIS WARMER AIR WL ADVECT NORTH INTO THE EASTERN
CPV/WESTERN SLOPES THIS AFTN. OTHERWISE...COOL NE FLW ACRS THE SLV
WL RESULT IN TEMPS ONLY IN THE U30S TO L40S. ALSO...SOME COOLER
TEMPS ANTICIPATED OVER THE SE UPSLOPE REGIONS OF THE GREENS.
INTERESTING EVENT LAST NIGHT WITH A DUSTING TO 4 INCHES OF SNOW
ACRS THE DACKS WITH SOME ICE ACCUMULATION ON POWERLINES AND TREES.
HAD SEVERAL REPORTS FROM POLICE AND MEDIA OF ISOLATED POWER
OUTAGES AND TREES DOWN DUE TO THE COMBINATION OF SNOW/ICE AND
GUSTY WINDS. SEE LATEST PNSBTV FOR FURTHER DETAILS.
QUICK UPDATE THIS MORNING TO FINE TUNE TIMING OF BACK EDGE OF
STEADIER/HEAVIER PRECIP ENDING ACRS OUR CENTRAL/NORTHERN CWA. CRNT
RADAR SHOWS STEADIER PRECIP ENDING ACRS CENTRAL VT INTO PARTS OF
THE DACKS...WHICH SHOULD CONT TO WORK NORTH TWD THE INTERNATIONAL
BORDER BY NOON. WL USE 100 POPS NORTH TO CHC POPS SOUTH THRU
NOON...THEN MENTION CHC POPS FOR THE REST OF THE DAY. TEMPS WL BE
TRICKY AND HIGHLY DEPEND UPON WINDS AND AMOUNT OF CLRING. VIS SATL
PIC SHOWS SOME BREAKS ACRS SOUTHERN VT ASSOCIATED WITH DRY SLOT
AND DEVELOPING DOWNSLOPE FLOW. THIS WL RESULT IN TEMPS WARMING
ALONG THE WESTERN SLOPES INTO THE 50S TO NEAR 60F...BUT COOL NE
FLW ACRS THE SLV WL KEEP THEM IN THE L/M40S. FOR THE CPV WL
MENTION HIGHS IN THE L/M50S AS WINDS SLOWLY SHIFT TO THE SE...WITH
MAINLY 40S FOR THE MTNS/CENTRAL VT.
HAVE CANCELLED THE WINTER WEATHER ADVISORY FOR THE NORTHERN
ADIRONDACKS AS DRY SLOT CONTINUES TO PROGRESS INTO NORTHERN NEW
YORK AND TEMPERATURES ARE SLOWLY WARMING FROM WARM AIR ADVECTION
ON THE NORTHEAST SIDE OF THE SFC LOW. FEW POCKETS OF RAIN/SNOW
MIX...AND POSSIBLY FREEZING RAIN MAY PERSIST...BUT LITTLE TO NO
ACCUMULATIONS EXPECTED AS TEMPERATURES WARM THIS MORNING.
DOWNSLOPING WINDS ON THE WESTERN SLOPES OF THE GREEN MOUNTAINS
HAS NOT COME TO FRUITION AS WINDS HAVE REMAINED 5 KTS OR LESS.
MODEL GUIDANCE SHOWS THAT THE 850MB JET HAS WEAKENED AND MOVED
NORTH...HAVE THEREFORE CANCELLED THE WIND ADVISORY FOR THAT AREA.
SUMMITS MAY STILL SEE STRONG GUSTS THIS MORNING INTO THE
AFTERNOON. ST. LAWRENCE VALLEY MAY STILL SEE SOME STRONG WIND
GUSTS AS 925MB JET HAS WEAKENED TO 30-45 KTS...BUT REMAINS OVER
THAT AREA THROUGH THE MORNING HOURS. HAVE KEPT THE WIND ADVISORY
OVER THE ST. LAWRENCE VALLEY FOR NOW.
OTHERWISE...PRECIPITATION MOVING INTO SOUTHERN VERMONT AND THE
CHAMPLAIN VALLEY MORE SHOWERY IN NATURE.
PREVIOUS DISCUSSION...ENHANCED CLOUD TOPS AND STRONG RADAR
REFLECTIVITIES OVER ADIRONDACKS IN NORTHERN NEW YORK WELL PROGGED
BY GFS FGEN. NAM SHOWING BEST FGEN MORE EAST...BUT BOTH MODELS
SHOW THIS FEATURE MOVING NORTH OUT OF THE AREA AS IT WEAKENS THIS
MORNING. WINTRY MIX AFFECTING THE NORTHERN ADIRONDACKS WITH
MAINLY SNOW OR RAIN AFFECTING THE ST LAWRENCE VALLEY.
TEMPERATURES GENERALLY WARMER AS YOU HEAD EAST...WITH RAIN
AFFECTING THE CHAMPLAIN VALLEY AND MOST OF VERMONT. TEMPS WILL
GRADUALLY WARM THIS MORNING WITH ANY WINTRY PRECIP CHANGING TO
ALL RAIN DURING THE DAY.
DRY SLOT SLOWLY ADVANCING NORTH FROM EASTERN NY THIS MORNING WILL
LEAD TO FEW BREAKS AND GENERALLY DECREASING POPS OVER THE NORTH
COUNTRY. AS SFC LOW SLOWS NEAR LAKE ONTARIO...NORTHERN NY LIKELY
TO SEE MORE PRECIP TODAY.
TYX RADAR WIND PROFILE SHOWING 40 KTS AT LOWEST LEVELS PERSISTING
EARLY THIS MORNING. LLJ OVER THE ST LAWRENCE VALLEY WEAKENING
DURING THE DAY WITH GUSTS IN THE MORNING OF 30-40 KTS DECREASING
TO LESS THAN 30 KTS THIS AFTERNOON. WIND NOT MIXING DOWN OFF THE
GREENS THIS MORNING WITH 850MB JET PROGGED TO WEAKEN QUICKLY
EARLY TODAY. LLJ ALSO LOOKS TO SHIFT MORE SOUTHERLY
TODAY...LIMITING DOWNSLOPING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
AS OF 502 AM EDT MONDAY...POTENTIAL FOR GUSTY WINDS EXISTS THROUGH
TUESDAY...BUT LLJ MUCH WEAKER. SFC LOW WILL PIVOT LATE TONIGHT
INTO TUESDAY...BRINGING A SURGE OF PRECIP OVER NORTHERN NY. THIS
WILL ALSO BRING IN COOLER TEMPERATURES...ESPECIALLY ALOFT...WITH
NEGATIVE SINGLE DIGIT TEMPS AT 850MB AND 925MB OVER NORTHERN NY
AND EDGING INTO VERMONT TONIGHT. WITH THESE COOLER TEMPS...CAN
EXPECT GREATER CHANCE FOR ANY PRECIP OVERNIGHT TO BE RAIN/SNOW MIX
TO ALL SNOW OVER THE ADIRONDACKS. SNOWFALL AMOUNTS OVERNIGHT WILL
RANGE FROM A DUSTING TO LESS THAN ONE INCH. THE COOLER AIR ALOFT
WILL LEAD TO COOLER MAX TEMPS ON TUESDAY...WITH HIGHS IN THE 40S
TO LOW 50S.
THE FAIRLY STACKED LOW WILL GAIN MOMENTUM NORTHWARD LATE TUESDAY
AND TUESDAY NIGHT WITH DECREASING CHANCES FOR PRECIP AS THE
DAY/NIGHT GO ON. THERES STILL A CHANCE FOR SNOW SHOWERS TUESDAY
NIGHT MAINLY OVER THE HIGHER TERRAIN WITH LESS THAN ONE INCH
ACCUMULATION EXPECTED AT THIS TIME.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 434 AM EDT MONDAY...SIMILAR TO THINKING SUNDAY AT THIS
TIME...MONDAY/S CLOSED SYSTEM WEAKENING AND BECOMING ABSORBED BY
CLOSED LOW IN JAMES BAY BUT WILL EVENTUALLY RETURN IN A DIFFERENT
FASHION LATER THIS WEEK AND EARLY NEXT WEEKEND. WINTER IN LATE
APRIL AFTER SUMMER IN MID-MARCH...GO FIGURE?!
AGAIN...TROFINESS HANGS ON WED WITH LESSENING CHC OF -SHRA EACH
MOMENT. OVERALL FLOW PATTERN STILL NW AND CYCLONIC BACKING
TOWARD W AND SW AHEAD OF NEXT STG S/W ROTATING ARD HUDSON BAY CLOSED
LOW WHICH WILL BRING A SERIES OF COLD FRONTS AND -SHRA THREAT ON
THU/THU NGT AND PSBLY FRI. THERE/S BEEN A ONGOING CHANGE HERE...
ALL MODELS ARE COMING INTO PHASE OF A STG NRN STREAM S/W ROTATING
INTO FA WITH SFC LOW DEVELOPMENT THU AFTN-FRI WHICH WILL BRING MORE
OF A STEADY PCPN VS SHOWERY WITH PERHAPS SOME SNOW AS WELL.
THEREAFTER...COLD NNW FLOW AND SFC HIGH DIRECTLY FM POLAR REGIONS
MOVES INTO FA FOR SAT/SUN. MIN/MAX TEMPS FOR FRI/SAT ARE FCST 10+
DEGS BLO NORMAL (DAYS 6/7) WHICH MEANS CUD BE COLDER.
THERE ARE STILL QUESTIONS FOR SUNDAY AS A LEFTOVER BOUNDARY FM
THU/FRI SYSTEM LIES JUST S OF SNE WITH ANOTHER NRN STREAM S/W
ROTATING SE TOWARD GRT LAKES AND POSSIBLE SFC LOW DVLPMNT ALG THIS
BOUNDARY WITH A THREAT OF RAIN ACRS SRN FA.
FROST/FREEZE PROGRAM BEGINS IN CHAMPL VLY/ST LWRNC VLY APRIL
25TH...APPROX 10 DAYS EARLY DUE TO ABNORMALLY WARM WINTER/SPRING AND
HORTICULUTURE SEASON RUNNING WEEKS EARLY.
BEGINNING/ENDING FROST/FREEZE PROGRAM IS ALWAYS PROBLEMATIC DUE TO
DIFFERENT CLIMATE REGIONS ACROSS CWA. IT WILL ACTUALLY BE COLDER IN
INTERIOR VERMONT AND NORTHERN NY YET DUE TO THE START OF THE PROGRAM
BEING MAY 5TH AND MAY 15TH THERE WUD BE NO HEADLINES.
HEADLINES OR NOT...IF TEMPERATURES GET INTO THE 20S/L30S PROTECTION
OF ANY CROPS/PLANTS NEED TO BE TAKEN. APPLE ORCHARDS AND WINE
VINEYARDS ARE AT A SUSCEPTIBLE POINT WITH TEMPS IN THE M20S POSSIBLY
CAUSING DEVASTATING EFFECTS.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
THROUGH 12Z TUESDAY...WIDESPREAD MVFR/IFR CONDITIONS EXPECTED
THROUGH THE PERIOD. HEAVIEST PCPN BEHIND US BUT STILL LOW CIGS.
NORTHEAST-EAST WINDS WILL BE PEAKING THRU 12-15Z THEN GRADUALLY
DECREASING WITH STRONGEST AT KMSS WITH SOME 25-30 KNOT GUSTS
POSSIBLE.
WEAK UPR LEVEL FLOW WITH CLOSED LOW TONIGHT WILL LIKELY MEAN
PERSISTENT OR SLIGHTLY LOWERING CIGS IFR/MVFR AS WELL AS POSSIBLE
MVFR/IFR VSBY.
OUTLOOK 12Z TUESDAY THROUGH FRIDAY...
12Z TUESDAY THROUGH 00Z THURSDAY...VFR WITH PERIODS OF MVFR/IFR IN
SCATTERED RAIN/SNOW SHOWERS WITH UPPER LEVEL LOW...ESPECIALLY AT
SLK/MPV.
00Z THURSDAY THROUGH 12Z THURSDAY...PRIMARILY VFR BETWEEN
STORM SYSTEMS.
12Z THURSDAY THROUGH FRIDAY...VFR WITH PERIODS OF MVFR/IFR IN
RAIN/SNOW SHOWERS WITH FRONTAL SYSTEM...ESPECIALLY SLK/MPV.
&&
.MARINE...
AS OF 445 AM EDT MONDAY...LAKE WIND ADVISORY IS IN EFFECT FOR
TODAY...ESPECIALLY THE MORNING.
NORTH WINDS OF 15 TO 25 WILL CONTINUE THROUGH MID-MORNING BEFORE
DECREASING TO 10 KNOTS THIS AFTERNOON.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KM
NEAR TERM...KM/TABER
SHORT TERM...KM
LONG TERM...SLW
AVIATION...RJS/SLW
MARINE...
AREA FORECAST DISCUSSION
NWS PORTLAND OR
220 PM PDT MON APR 23 2012
.SYNOPSIS...NEAR RECORD WARMTH THIS AFTERNOON AND ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS NEAR THE CASCADE CREST WILL GIVE
WAY TO COOLER AND MORE SHOWERY WEATHER ON TUESDAY. AN UPPER LEVEL
TROUGH WILL BRING HEAVIER AND PERSISTENT SHOWERS AT TIMES...AND
COOLER THAN NORMAL TEMPERATURES TO WESTERN OREGON AND WASHINGTON LATE
WEDNESDAY INTO THURSDAY. COOL WEATHER AND LIGHT SHOWERS WILL LIKELY
PERSIST INTO THE WEEKEND.
&&
.SHORT TERM...VISIBLE SATELLITE IMAGERY SHOWS CUMULUS BEGINNING TO
POP ACROSS SOUTHWESTERN OREGON. MUCH OF THE FORECAST AREA REMAINS
CLEAR AND CAPPED...BUT THIS SHOULD CHANGE IN THE NEXT FEW
HOURS...PARTICULARLY SOUTH AND EAST OF EUGENE WHERE THUNDERSTORMS
SHOULD BEGIN TO DEVELOP. STORMS WILL GENERALLY MOVE IN A
NORTH-NORTHEASTERLY DIRECTION AND TREND INTO PENDLETONS FORECAST
AREA EAST OF THE CASCADES THIS EVENING. NONETHELESS...A SEVERE STORM
OR TWO WILL BE POSSIBLE ON OUR SIDE OF THE MOUNTAINS BEFORE CROSSING
EAST OF THE CASCADES GIVEN THE INSTABILITY AND SHEAR.
A PUSH OF COOLER...MORE STABLE MARITIME AIR WILL SPILL INTO THE
WILLAMETTE VALLEY THIS EVENING. HRRR CONTINUES TO BRING THIS INTO THE
VALLEY BETWEEN 5-7PM. THIS BOUNDARY MAY PROVIDE ENOUGH LIFT TO POP A
THUNDERSTORM OUT AHEAD OF THE MAIN ACTION THAT DEVELOPS TO THE SOUTH
AND EAST OF EUGENE. ALTHOUGH...NONE OF THE CURRENT MODEL RUNS DEPICT
THIS HAPPENING AT THIS TIME. THE HRRR WOULD SUGGEST THE BEST THREAT
FOR AN OUTFLOW FROM AN EXISTING STORM TO INITIATE A NEW STORM OVER
THE NORTHERN WILLAMETTE VALLEY WOULD BE LATE THIS EVENING...BUT
CONFIDENCE IS VERY LOW IN THIS ACTUALLY OCCURRING.
LOW CLOUDS AND LIGHT SHOWERS WILL BE THE NORM FOR TUESDAY AS ONSHORE
FLOW STRENGTHENS. A LOW PRESSURE IN THE GULF OF ALASKA WILL THEN DROP
SOUTHWARD AND AN ELONGATED FRONT WILL APPROACH THE REGION ON
WEDNESDAY. SOUTHWEST FLOW AHEAD OF THE MAIN FRONTAL BAND WILL BRING
RAIN SHOWERS TO THE REGION...BEGINNING TUESDAY NIGHT INTO WEDNESDAY.
A THIRD TO TWO THIRDS OF AN INCH OF RAIN APPEARS PROBABLE ACROSS THE
VALLEYS BY THURSDAY. COOLER THAN NORMAL TEMPERATURES WILL RETURN BY
THURSDAY AS WELL. /NEUMAN
.LONG TERM...THURSDAY EVENING THROUGH SUNDAY...MODELS AGREE ON THE
DEVELOPMENT OF A FLAT UPPER LEVEL RIDGE OVER THE EASTERN PACIFIC AT
THE END OF THE WEEK AND THROUGH THE WEEKEND. A SYSTEM CRESTS THE
RIDGE AND MOVES INTO THE PACIFIC NORTHWEST LATE FRIDAY WITH SHOWERS
LINGERING THROUGH THE SATURDAY. THOUGH TIMING DIFFERENCES EXIST...
THE GFS AND THE ECMWF BOTH SHOW A POSSIBILITY OF DRIER WEATHER
SUNDAY...AND THE CANADIAN TO A LESSER EXTENT. THE FLATTENED RIDGE
ALLOWS ANOTHER SYSTEM TO APPROACH THE PACIFIC NORTHWEST AND BRING
RAIN EARLY NEXT WEEK. KELSON
&&
.AVIATION...IFR STRATUS AND FOG HAS DISSIPATED ALONG THE NORTHERN
COAST AND HAS DISSIPATED TO THE BEACHES ALONG THE CENTRAL COAST. THE
FOG/LOW STRATUS IS EXPECTED TO RETURN THIS EVENING AS LOW MVFR/IFR
CIGS. INLAND AREAS...VFR CONDITIONS THIS AFTERNOON/EVENING. SOMEWHAT
UNSTABLE CONDITIONS WITH LOW CHANCES OF THUNDERSTORMS OVER THE
INLAND VALLEYS WITH GREATER CHANCES OVER THE CASCADES AND COAST
RANGE. SOUTHWEST ONSHORE FLOW INCREASES TONIGHT...WITH THE MARINE
AIR MASS SPREADING INLAND GIVING MVFR CIGS AROUND 2000 FEET.
KPDX AND APPROACHES...VFR CONDITIONS THIS AFTERNOON/EVENING WITH
ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS. MVFR CIGS EXPECTED
AFTER 10Z TUE AS MARINE STRATUS MOVES INLAND.
&&
.MARINE...NORTHERLY WINDS INCREASING AS A RIDGE OF HIGH PRES BUILDS
OVER THE OFFSHORE WATERS. WINDS AND SEAS RATHER BENIGN THROUGH
TUE...WITH WINDS UNDER 20 KT AND SEAS REMAINING UNDER 7 FT. NEXT
THREAT FOR SMALL CRAFT WINDS COMES WED WHEN A COLD FRONT APPROACHES.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
525 PM CDT MON APR 23 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY.
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM THE SOUTHERN GREAT PLAINS...ACROSS THE
WESTERN GREAT LAKES TO WESTERN HUDSON BAY EARLY THIS AFTERNOON.
VERY DRY AIR JUST OFF THE SURFACE PER 12Z GRB RAOB HAS LED TO
DEWPOINTS PLUMMETING INTO THE SINGLE DIGITS OVER SOME OF THE SANDY
SOIL AREAS OF FAR NE AND NORTH-CENTRAL WISCONSIN. UPSTREAM...PLENTY
OF MID AND HIGH CLOUDS OVER NORTHERN MINNESOTA INTO MANITOBA WHERE
ISENTROPIC ASCENT IS OCCURRING ON THE 295-300K SURFACES. MAIN
FORECAST CONCERNS INCLUDE CLOUD COVERAGE AND PRECIP CHANCES AS THE
UPSTREAM ISENTROPIC ASCENT MOVES INTO WISCONSIN TONIGHT INTO TUESDAY.
TONIGHT...LOW PRESSURE WILL MOVE NORTHEAST INTO SOUTHEAST ONTARIO
WHILE A WEAK AREA OF HIGH PRESSURE WILL REMAINED ANCHORED FROM
HUDSON BAY...ACROSS THE WESTERN GREAT LAKES...TO THE GULF COAST.
MOISTURE WILL CONTINUE TO SPILL OVER TOP OF THE RIDGE CENTERED OVER
THE ROCKIES AND FILTER ACROSS THE STATE FROM WEST TO EAST TONIGHT.
WILL HAVE INCREASING CLOUDS AS A RESULT...BUT NOT ENOUGH TO GO MORE
THAN PARTLY CLOUDY WEST TO MOSTLY CLEAR IN THE EAST. LOWS ARE
TRICKY DUE TO THE DRY AIRMASS IN PLACE YET WILL HAVE INCREASING
CLOUDS. WILL GO WITH LOWS RANGING FROM THE UPPER 20S NORTH TO UPPER
30S SOUTHEAST.
TUESDAY...850MB WARM FRONT WILL MOVE INTO THE NORTHERN MISSISSIPPI
VALLEY WHILE MID-LEVEL MOISTURE FROM THE LAKE WINNIPEG REGION WILL
SLIDE SOUTHEAST ACROSS THE AREA DURING THE MORNING. AS DIURNAL
HEATING OCCURS...WILL SEE CAPES BETWEEN 50-100 J/KG DEVELOP THAT
SHOULD HELP FILL IN WHATEVER HOLES THERE ARE IN THE CLOUD DECK.
WOULDNT BE SURPRISED TO SEE MOSTLY CLOUDY CONDITIONS DEVELOP BY
MIDDAY...BUT WILL GO WITH PARTLY SUNNY WORDING INSTEAD TO BLEND WITH
SURROUNDING OFFICES. BOTH THE NAM AND GFS TRIGGER LIGHT QPF OVER EASTERN
WISCONSIN. THINK THIS IS A TOO PESSIMISTIC...AS ITS TOUGH TO FIND A
TRIGGER...AND INSTABILITY IS PRETTY MEAGER. SO WILL STAY WITH A DRY
FORECAST. DRIER AIR DOES RETURN FROM THE NORTH DURING THE
AFTERNOON...SO SHOULD SEE AT LEAST PARTIAL CLEARING ARRIVE. HIGHS
ROUGHLY ABOUT 4 DEGREES WARMER THAN TODAY...FROM THE UPPER 50S NORTH
TO MIDDLE 60S SOUTH.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY...MAIN FCST CONCERNS
ARE PCPN TRENDS FOR THE MIDWEEK PERIOD AND NEXT WEEKEND.
LOW PRESSURE OVER THE NORTHERN PLAINS ON TUESDAY EVG IS EXPECTED TO
SHIFT SE TOWARD ILLINOIS ON WEDNESDAY. A FAIRLY STG BAROCLINIC
ZONE WILL SET UP OVER THE REGION...WITH ISENT LIFT DEVELOPING LATE
TUESDAY NIGHT INTO WEDNESDAY AS LLVL FLOW BECOMES SW AHEAD OF AN
APPROACHING COLD FRONT. IN ADDITION...SOME SHORT-WAVE ENERGY AND THE
RRQ OF AN UPPER JET STREAK WILL BE PULLING THROUGH THE AREA. HAVE
KEPT CHC POPS FOR OUR SW COUNTIES AFTER MIDNIGHT TUESDAY NIGHT...
THEN ADJUSTED PCPN TRENDS AS PCPN SPREADS NORTHEAST ON WEDNESDAY.
RAISED POPS INTO THE LIKELY CATEGORY OVER ABOUT THE SW TWO-THIRDS
OF THE CWA ON WEDS. ALSO ADDED A CHC OF TSTMS ON WEDS AFTERNOON AS
MODELS SHOW A BAND OF INSTABILITY DEVELOPING IN ADVANCE OF THE
COLD FRONT. THIS FRONT SHOULD GENERATE SOME SHOWERS INTO WEDS
NIGHT...ESPECIALLY DURING THE EVG.
CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION IN THE WAKE OF
THE COLD FRONT ON THURSDAY AND FRIDAY...BRINGING DRY AND COOLER
CONDITIONS. SUB-FREEZING TEMPERATURES WILL ONCE AGAIN BE POSSIBLE ON
THURSDAY NIGHT.
A BATTLE OF THE AIR MASSES IS SETTING UP FOR THE WEEKEND...WITH
DRY CANADIAN HIGH PRESSURE STILL RIDGED TO OUR NORTH...AND LOW
PRESSURE AND ABUNDANT MOISTURE TRACKING THROUGH THE UPPER MIDWEST.
AS THE LOW PASSES TO OUR SOUTH...EXPECT NE WINDS TO INCREASE...
WHICH SHOULD REINFORCE THE DRY AIR OVER AT LEAST NORTHERN WI.
WILL CARRY SOME LOW CHANCE POPS OVER MAINLY OUR SOUTHERN COUNTIES
SATURDAY INTO SUNDAY...BUT WOULD NOT BE SURPRISED IF THE DRY AIR
EVENTUALLY WINS THIS BATTLE.
THE CANADIAN HIGH IS EXPECTED TO SAG SOUTH OVER THE REGION AGAIN
LATER SUNDAY INTO MONDAY...WITH ASSOCIATED DRY CONDITIONS.
&&
.AVIATION...A VFR CIG WILL SPREAD OVER THE AREA LATE TONIGHT AND
CONTINUE INTO TUESDAY. A DEEP LOW PRESSURE SYSTEM OVER THE EASTERN
SEABOARD REGION WILL CONTINUE TO PRODUCE GUSTY NORTH WINDS THIS
EVENING OVER EASTERN WISCONSIN. WINDS WILL DIMINISH OVERNIGHT INTO
TUESDAY MORNING...HOWEVER GUSTY NORTHWEST WINDS MAY OCCUR AGAIN
TUESDAY AFTERNOON.
TDH
&&
.MARINE...A TIGHTENING PRESSURE GRADIENT WILL LEAD TO NEAR SMALL
CRAFT ADVISORY WIND GUSTS OVER THE NEARSHORE WATERS THIS EVENING.
THE AREA AROUND DEATHS DOOR WILL BE THE MOST PRONE FOR THESE HIGHER
GUSTS.
&&
.FIRE WEATHER...DRY AIR JUST OFF THE SURFACE PER 12Z GRB RAOB HAS
LED TO RH/S CRASHING TO THE 10-15 PCT RANGE OVER MUCH OF FAR
NORTHEAST AND NORTH-CENTRAL WISCONSIN. WITH WIND GUSTS UP TO 20
KTS...WILL CONTINUE TO MENTION AN ELEVATED FIRE DANGER IN THE HWO.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
258 PM CDT MON APR 23 2012
.SHORT TERM...TONIGHT AND TUESDAY.
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM THE SOUTHERN GREAT PLAINS...ACROSS THE
WESTERN GREAT LAKES TO WESTERN HUDSON BAY EARLY THIS AFTERNOON.
VERY DRY AIR JUST OFF THE SURFACE PER 12Z GRB RAOB HAS LED TO
DEWPOINTS PLUMMETING INTO THE SINGLE DIGITS OVER SOME OF THE SANDY
SOIL AREAS OF FAR NE AND NORTH-CENTRAL WISCONSIN. UPSTREAM...PLENTY
OF MID AND HIGH CLOUDS OVER NORTHERN MINNESOTA INTO MANITOBA WHERE
ISENTROPIC ASCENT IS OCCURRING ON THE 295-300K SURFACES. MAIN
FORECAST CONCERNS INCLUDE CLOUD COVERAGE AND PRECIP CHANCES AS THE
UPSTREAM ISENTROPIC ASCENT MOVES INTO WISCONSIN TONIGHT INTO TUESDAY.
TONIGHT...LOW PRESSURE WILL MOVE NORTHEAST INTO SOUTHEAST ONTARIO
WHILE A WEAK AREA OF HIGH PRESSURE WILL REMAINED ANCHORED FROM
HUDSON BAY...ACROSS THE WESTERN GREAT LAKES...TO THE GULF COAST.
MOISTURE WILL CONTINUE TO SPILL OVER TOP OF THE RIDGE CENTERED OVER
THE ROCKIES AND FILTER ACROSS THE STATE FROM WEST TO EAST TONIGHT.
WILL HAVE INCREASING CLOUDS AS A RESULT...BUT NOT ENOUGH TO GO MORE
THAN PARTLY CLOUDY WEST TO MOSTLY CLEAR IN THE EAST. LOWS ARE
TRICKY DUE TO THE DRY AIRMASS IN PLACE YET WILL HAVE INCREASING
CLOUDS. WILL GO WITH LOWS RANGING FROM THE UPPER 20S NORTH TO UPPER
30S SOUTHEAST.
TUESDAY...850MB WARM FRONT WILL MOVE INTO THE NORTHERN MISSISSIPPI
VALLEY WHILE MID-LEVEL MOISTURE FROM THE LAKE WINNIPEG REGION WILL
SLIDE SOUTHEAST ACROSS THE AREA DURING THE MORNING. AS DIURNAL
HEATING OCCURS...WILL SEE CAPES BETWEEN 50-100 J/KG DEVELOP THAT
SHOULD HELP FILL IN WHATEVER HOLES THERE ARE IN THE CLOUD DECK.
WOULDNT BE SURPRISED TO SEE MOSTLY CLOUDY CONDITIONS DEVELOP BY
MIDDAY...BUT WILL GO WITH PARTLY SUNNY WORDING INSTEAD TO BLEND WITH
SURROUNDING OFFICES. BOTH THE NAM AND GFS TRIGGER LIGHT QPF OVER EASTERN
WISCONSIN. THINK THIS IS A TOO PESSIMISTIC...AS ITS TOUGH TO FIND A
TRIGGER...AND INSTABILITY IS PRETTY MEAGER. SO WILL STAY WITH A DRY
FORECAST. DRIER AIR DOES RETURN FROM THE NORTH DURING THE
AFTERNOON...SO SHOULD SEE AT LEAST PARTIAL CLEARING ARRIVE. HIGHS
ROUGHLY ABOUT 4 DEGREES WARMER THAN TODAY...FROM THE UPPER 50S NORTH
TO MIDDLE 60S SOUTH.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY...MAIN FCST CONCERNS
ARE PCPN TRENDS FOR THE MIDWEEK PERIOD AND NEXT WEEKEND.
LOW PRESSURE OVER THE NORTHERN PLAINS ON TUESDAY EVG IS EXPECTED TO
SHIFT SE TOWARD ILLINOIS ON WEDNESDAY. A FAIRLY STG BAROCLINIC
ZONE WILL SET UP OVER THE REGION...WITH ISENT LIFT DEVELOPING LATE
TUESDAY NIGHT INTO WEDNESDAY AS LLVL FLOW BECOMES SW AHEAD OF AN
APPROACHING COLD FRONT. IN ADDITION...SOME SHORT-WAVE ENERGY AND THE
RRQ OF AN UPPER JET STREAK WILL BE PULLING THROUGH THE AREA. HAVE
KEPT CHC POPS FOR OUR SW COUNTIES AFTER MIDNIGHT TUESDAY NIGHT...
THEN ADJUSTED PCPN TRENDS AS PCPN SPREADS NORTHEAST ON WEDNESDAY.
RAISED POPS INTO THE LIKELY CATEGORY OVER ABOUT THE SW TWO-THIRDS
OF THE CWA ON WEDS. ALSO ADDED A CHC OF TSTMS ON WEDS AFTERNOON AS
MODELS SHOW A BAND OF INSTABILITY DEVELOPING IN ADVANCE OF THE
COLD FRONT. THIS FRONT SHOULD GENERATE SOME SHOWERS INTO WEDS
NIGHT...ESPECIALLY DURING THE EVG.
CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION IN THE WAKE OF
THE COLD FRONT ON THURSDAY AND FRIDAY...BRINGING DRY AND COOLER
CONDITIONS. SUB-FREEZING TEMPERATURES WILL ONCE AGAIN BE POSSIBLE ON
THURSDAY NIGHT.
A BATTLE OF THE AIR MASSES IS SETTING UP FOR THE WEEKEND...WITH
DRY CANADIAN HIGH PRESSURE STILL RIDGED TO OUR NORTH...AND LOW
PRESSURE AND ABUNDANT MOISTURE TRACKING THROUGH THE UPPER MIDWEST.
AS THE LOW PASSES TO OUR SOUTH...EXPECT NE WINDS TO INCREASE...
WHICH SHOULD REINFORCE THE DRY AIR OVER AT LEAST NORTHERN WI.
WILL CARRY SOME LOW CHANCE POPS OVER MAINLY OUR SOUTHERN COUNTIES
SATURDAY INTO SUNDAY...BUT WOULD NOT BE SURPRISED IF THE DRY AIR
EVENTUALLY WINS THIS BATTLE.
THE CANADIAN HIGH IS EXPECTED TO SAG SOUTH OVER THE REGION AGAIN
LATER SUNDAY INTO MONDAY...WITH ASSOCIATED DRY CONDITIONS.
&&
.AVIATION...VFR CONDITIONS TODAY THOUGH WILL HAVE INCREASING AND
GUSTY NORTH WINDS THROUGH EARLY THIS EVENING. BKN MID AND HIGH
CLOUDS WILL DRIFT ACROSS THE TAF SITES FROM THE NORTH TONIGHT...AND
LOWER TO ABOUT 5-7KFT TUESDAY MORNING. PARTIAL CLEARING IS
ANTICIPATED BY LATE TUESDAY AFTERNOON.
MPC
&&
.MARINE...A TIGHTENING PRESSURE GRADIENT WILL LEAD TO NEAR SMALL
CRAFT ADVISORY WIND GUSTS OVER THE NEARSHORE WATERS THIS EVENING.
THE AREA AROUND DEATHS DOOR WILL BE THE MOST PRONE FOR THESE HIGHER
GUSTS.
&&
.FIRE WEATHER...DRY AIR JUST OFF THE SURFACE PER 12Z GRB RAOB HAS
LED TO RH/S CRASHING TO THE 10-15 PCT RANGE OVER MUCH OF FAR
NORTHEAST AND NORTH-CENTRAL WISCONSIN. WITH WIND GUSTS UP TO 20
KTS...WILL CONTINUE TO MENTION AN ELEVATED FIRE DANGER IN THE HWO.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/KIECKBUSCH