Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 01/25/12
AREA FORECAST DISCUSSION
NWS PUEBLO CO
321 PM MST MON JAN 23 2012
.SHORT TERM...
(TONIGHT AND TUESDAY)
CURRENT WATER VAPOR IMAGERY AND RUC80 DATA SHOW THE APPROACHING
STORM SYSTEM OVER CENTRAL NEVADA AT THIS TIME. THE 12Z NAM12 AND
GFS FORECAST THE LOW TO MOVE SOUTH OF THE FOUR CORNERS AREA INTO
SOUTHWESTERN NEW MEXICO BY 18Z TUESDAY.
12Z NAM12 AND GFS AND THE 17Z HRRR SHOW SNOW BEGINNING IN THE
SOUTHWESTERN MOUNTAINS BETWEEN 01Z AND 02Z TUESDAY. I DECIDED TO
BLEND THE 12Z NAM12 AND GFS (THE NAM12 BEING THE HEAVIEST ON QPF AND
THE GFS BEING THE LIGHTEST)...AND HAVE ISSUED A WINTER WEATHER
ADVISORY FOR THE SAN JUAN MOUNTAINS BEGINNING AT 01Z. CURRENT TOTAL
SNOW GRID SHOWS FIVE TO SEVEN INCHES OF SNOW ON THE HIGHEST PEAKS OF
THE SAN JUANS. WITH THE UPPER LOW PASSING WELL TO THE SOUTH AND
SOUTHWEST UPLOPE FLOW ON THE WEAK SIDE...SNOW TOTALS ARE ON THE LOW
SIDE OF ADVISORY CRITERIA...BUT FEEL AT LEAST THE PEAKS WILL REACH
ADVISORY CRITERIA.
THE SANGRES...ESPECIALLY THE SOUTHERN PEAKS...WILL ALSO RECEIVE LIGHT
TO MODERATE SNOWS (3-5 INCHES)...BUT WILL REMAIN BELOW ADVISORY
CRITERIA DURING THIS EVENT...AS WILL THE EASTERN SAWATCH AND WESTERN
MOSQUITOES RANGES. THE SAN LUIS VALLEY WILL ONLY LIKELY SEE A DUSTING
OF SNOW.
THE INTERSTATE 25 CORRIDOR AND EASTERN PLAINS WILL LIKELY NOT SEE
ANY APPRECIABLE PRECIPITATION FROM THIS SYSTEM WITH ONLY 50 POPS IN
THE GRIDS FOR COS AND PUB AND ISOLATED POPS FOR THE EASTERN PLAINS.
PRECIPITATION WILL QUICKLY DISSIPATE FROM NORTH TO SOUTH AFTER 18Z
AS THE THEN CLOSED 500MB LOW MOVES WELL SOUTH OF THE FORECAST
AREA.
.LONG TERM...
(TUESDAY NIGHT THROUGH MONDAY)
TUESDAY NIGHT-THURSDAY...MODERATE NORTH TO NORTHWEST FLOW ALOFT
ACROSS THE REGION TUESDAY NIGHT AND WEDNESDAY BEHIND PASSING UPPER
TROUGH BECOMES MORE WESTERLY WEDNESDAY NIGHT AND THURSDAY AS UPPER
LEVEL RIDGING BUILDS ACROSS THE STATE. GENERALLY LIGHT PRECIPITATION
ONGOING ACROSS THE SOUTHEAST MOUNTAINS AND FAR SE PLAINS TUESDAY
AFTERNOON LOOKS TO DIMINISH TUESDAY EVENING WITH SKIES CLEARING FROM
WEST TO EAST TUESDAY NIGHT. THERE REMAINS SOME MODEL DIFFERENCES ON
NORTHERN EXTENT OF DEFORMATION BAND PRECIP SHIELD ASSOCIATED WITH
UPPER LOW MOVING EAST ACROSS CENTRAL NEW MEXICO...WITH THE LATEST
GFS AND ECMWF KEEPING ANY PRECIPITATION WELL SOUTH AND EAST OF THE
AREA. THE NAM CONTINUES TO DEVELOP PRECIP ACROSS THE WESTERN TX/OK
PANHANDLE WHICH SLIDES NORTH AND EAST INTO SOUTHEASTERN COLORADO
TUESDAY NIGHT. AT ANY RATE...HAVE KEPT SLIGHT POPS ACROSS MAINLY
SOUTHERN BACA COUNTY TO ACCOUNT FOR THIS...WHICH ALSO BLENDS BETTER
WITH SURROUNDING OFFICES. DRY WEATHER WITH ABOVE SEASONAL
TEMPERATURES IS THEN EXPECTED ACROSS THE AREA FOR WEDNESDAY AND
THURSDAY UNDER THE BUILDING RIDGE. THURSDAY STILL LOOKS TO BE THE
WARMEST DAY OF THE WEEK...THOUGH TEMPERATURES MAY BE TEMPERED BY
INCREASING HIGH LEVEL CLOUDS STREAMING ACROSS THE AREA THROUGH THE
AFTERNOON.
THURSDAY NIGHT-FRIDAY NIGHT...MODELS HAVE COME INTO BETTER AGREEMENT
OF WIDESPREAD SNOWFALL DEVELOPING ACROSS HIGHER TERRAIN AND
IMMEDIATE ADJACENT PLAINS THROUGH THIS PERIOD...AS A SHORT WAVE
EMBEDDED WITHIN THE MODERATE WESTERLY FLOW ALOFT MOVES ACROSS THE
ROCKIES. QUICK MOVEMENT OF SYSTEM LIMITS SNOW DURATION...THOUGH SHOULD
AT LEAST SEE SOME LIGHT ACCUMULATIONS ACROSS THE CENTRAL MTS
THROUGH THE EASTERN MTS...ALONG WITH THE PALMER DIVIDE AND RATON
MESA...AS NORTH TO NORTHEAST SFC-H7 FLOW DEVELOPS THROUGH THE DAY.
SYSTEM SENDS A FAIRLY STRONG COLD FRONT ACROSS THE AREA THURSDAY
NIGHT AND EARLY FRIDAY...WITH HIGHS FRIDAY LIKELY EARLY IN THE
MORNING WITH STEADY AND FALLING TEMPERATURES INTO THE AFTERNOON.
SATURDAY-MONDAY...MODERATE WEST TO NORTHWEST CONTINUES ACROSS THE
REGION THROUGH THE REST OF THE EXTENDED PERIOD WITH LATEST MODELS
STILL INDICATING DIFFERENCES IN HARD TIME SHORT WAVES TRANSLATING
THROUGH THE FLOW. WITH TIMING DIFFERENCES...HAVE KEPT CURRENT
ISOLATED POPS ACROSS MAINLY THE CENTRAL MTS THROUGH THE PERIOD ALONG
WITH AT OR ABOVE SEASONAL TEMPERATURES. -MW
&&
.AVIATION...
LOWERING CIGS EXPECTED TONIGHT...ESPECIALLY ACROSS THE WESTERN
MOUNTAINS AND SAN LUIS VALLEY WITH CIGS DROPPING INTO THE MVFR
CATEGORY AFTER 09Z AT KALS. -SHSN WILL BE POSSIBLE FROM
09Z-17Z...WITH ANY ACCUMULATIONS EXPECTED TO REMAIN UNDER AN
INCH.
FOR KCOS AND KPUB...VFR CIGS WILL SPREAD INTO BOTH TAF SITES LATE
TONIGHT WITH GUSTY NORTH WINDS 10-20 KTS ASSOCIATED WITH A COLD
FRONT SPREADING INTO KCOS AND KPUB BETWEEN 15-17Z TUES. CIGS WILL
CONTINUE TO LOWER FOR BOTH TAF SITES DURING THE LATE MORNING/EARLY
AFTERNOON...DROPPING INTO THE MVFR CATEGORY. MTN OBSCURATIONS ARE
EXPECTED FOR THE SE MTS BY AFTERNOON WITH ISOLATED LIGHT SNOW
SHOWERS POSSIBLE FOR LOCATIONS NEAR THE MTS. DUE TO LOW PROBABILITY
OF -SHSN AFFECTING THE TAF SITES...WILL KEEP VCSH IN KCOS AND KPUB
TAFS FOR NOW.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 11 AM MST
TUESDAY FOR COZ068.
&&
$$
81/23
AREA FORECAST DISCUSSION
NWS ALBANY NY
1244 PM EST MON JAN 23 2012
.SYNOPSIS...
AFTER SOME LIGHT ICING CONDITIONS THROUGH EARLY THIS AFTERNOON
ACROSS AREAS NORTH AND EAST OF ALBANY...TEMPERATURES WILL CLIMB TO
ABOVE FREEZING AND PRODUCE MAINLY RAIN SHOWERS THAT WILL ACCOMPANY A
FRONTAL BOUNDARY AS IT CROSSES THE REGION. SOMEWHAT COOLER AIR WILL
FILTER IN FOR TUESDAY WITH SOME LAKE EFFECT SNOW DOWNWIND OF LAKE
ONTARIO. THERE WILL BE TRANQUIL CONDITIONS FOR THE MID WEEK AS A
RIDGE OF HIGH PRESSURE TRACKS ACROSS THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD TEMPS PERSIST ACROSS WESTERN NEW ENGLAND ZONES SO HAVE EXTENDED
THE FREEZING RAIN ADVISORY THERE THROUGH 200 PM. TEMPS IN THE
IMMEDIATE CONNECTICUT VALLEY OF EASTERN WINDHAM COUNTY MAY STILL BE
BELOW FREEZING AT THAT TIME...BUT WILL WAIT UNTIL THEN TO DECIDE ON
ANY ADDITIONAL EXTENSIONS OF THE ADVISORY. ELSEWHWERE ADVISORIES
HAVE BEEND ALLOWED TO EXPITE ACROSS THE MOHAWK/SCHOHARIE VALLEYS...
EASTERN CATSKILLS...CAPITAL DISTRICT AND TACONICS. HAVE CANCELLED
THE ADVISORY ACROSS ALL OF HERKIMER COUNTY SINCE MESONET OBS
INDICATE THE FAR WESTERN ADIRONDACKS HAVE WARMED TO ABOVE FREEZING.
THE ADVISORY CONTINUES FOR THE REST OF THE ADIRONDACKS AND LAKE
GEORGE REGION THROUGH 200 PM.
****PREVIOUS DISCUSSION****
AS OF 11 AM EST...HAVE DROPPED FREEZING RAIN ADVISORY FOR THE MID
HUDSON VALLEY REGION...WHERE TEMPS HAVE WARMED ABOVE FREEZING.
ELSEWHERE...HAVE KEPT FREEZING RAIN ADVISORIES IN PLACE...ALTHOUGH
TEMPS NOW RISING TO NEAR OR ABOVE FREEZING ACROSS THE EASTERN
CATSKILLS...SCHOHARIE VALLEY...AND THE CAPITAL REGION.
FURTHER N AND E...COLD AIR HANGING TOUGH...FROM SE VT INTO THE
BERKSHIRES AND SOUTH INTO EASTERN LITCHFIELD COUNTY...WHERE
DRIZZLE PERSISTS. WE MAY NEED TO EXTEND THE ADVISORIES FOR
PORTIONS OF THESE AREAS...AS COLD AIR MAY REMAIN TOUGH TO
DISLODGE.
STEADIER RAIN SHOULD DEVELOP FROM W TO E DURING THE MID TO LATE
AFTERNOON HOURS. THERE IS SOME POSSIBILITY THAT POCKETS OF
SUBFREEZING TEMPS PERSIST IN PORTIONS OF SE VT AND/OR THE
BERKSHIRES WHEN THIS ARRIVES...SO WILL NEED TO MONITOR CLOSELY.
PREVIOUS DISCUSSION FOLLOWS...
AS OF 6 AM...DRIZZLE IS BEGINNING TO SHOW UP ACROSS THE TRI-STATE
REGION AND MID-HUDSON VALLEY INCLUDING OUR RADAR IN VCP31.
TEMPERATURES VARY BUT THEY DO HOVER AROUND THE FREEZING MARK WHERE
DRIZZLE IS BEING REPORTED. NCEP MODEL SUITE ALONG WITH THE
RUC13/HRRR NOT DOING THAT WELL...HOWEVER...THEY DO SUGGEST THIS
AREA OF DRIZZLE AND SATURATING BOUNDARY LAYER ADVANCES SLOWLY
NORTH THIS MORNING. WET BULB PROFILES ARE STILL BELOW FREEZING SO
WE WILL CONTINUE WITH THE ADVISORY AND REFRESH THE GRIDS AND
HOURLY TEMPS/DEWPTS. PER THE 06Z MOS AND HOURLY LAV/LAMP...MOST
AREAS WILL CLIMB ABOVE FREEZING AROUND THE NOON HOUR.
PREV DISC...
VERY CHALLENGING NEAR TERM FORECAST AS FZDZ HAS NOT
MATERIALIZED AT THIS TIME. PER METARS...THE CIGS REMAIN RATHER
HIGH AND DEWPOINT DEPRESSIONS ARE 5 DEGREES OR GREATER. WE DID
RECEIVE A REPORT OF FLURRIES IN LITCHFIELD COUNTY AND THIS CAN
ALSO BE CONFIRMED WITH SEVERAL METARS ACROSS THE NYC METRO AREA
REPORTING LIGHT SNOW. THIS MAY BE DUE TO THE OCEANIC EFFECT ADDING
ENOUGH NUCLEI TO RESULT IN THOSE OBS OF LIGHT SNOW. THE FORECAST
SOUNDINGS ACROSS OUR REGION STILL SUGGEST THE BOUNDARY LAYER WILL
MOISTEN UP BELOW THE -10C ISOTHERM INCLUDING THE SHEAR PROFILES
FOR SOME DRIZZLE FORMATION. RUC13 FORECAST SOUNDINGS DELAY THE
ONSET OF MOISTURE UNTIL THE 12-15Z TIME FRAME. BY THAT
TIME...TEMPERATURES ARE BEGINNING TO CLIMB TO AT OR ABOVE FREEZING
ALONG AND SOUTH OF I90. THE COLDER AIR IS EXPECTED TO REMAIN IN
PLACE LONGER ACROSS THE DACKS...LAKE GEORGE SARATOGA REGION AND
SOUTHERN VERMONT UNTIL ABOUT THE NOON HOUR. THE ADVISORY LOOKS
GOOD AT THIS TIME WITH NO CHANGES EXPECTED.
POTENT SHORT WAVE TRACKING NORTHWARD ALONG THE MISSISSIPPI RIVER
VALLEY INTO THE GREAT LAKES REGION WILL SEND A COLD FRONT EASTWARD
THIS AFTERNOON. A BAND OF BKN SHOWERS IS EXPECTED AND WE WILL
PLACE CATEGORICAL POPS FOR THE ENTIRE REGION. TIMING OF THIS FRONT
APPEARS TO BE AOA 21Z. AS FOR CONVECTIVE POTENTIAL /IE
THUNDER/...THE SHOWALTER INDEX IS EXPECTED TO DROP TOWARD 0C FOR
PORTIONS OF THE REGION WITH THE BEST UPPER SUPPORT FOR THE WESTERN
MOHAWK VALLEY AND DACKS. WHILE WE WILL NOT INCLUDE THUNDER...WOULD
NOT TOTALLY RULE OUT A RUMBLE OF THUNDER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
WITH FROPA...DRY SLOT QUICKLY APPROACHES THIS EARLY EVENING. SOME
LINGERING UPSLOPE SHOWERS ARE EXPECTED BUT THIS TOO SHOULD
DECREASE THROUGH TONIGHT. SEEMS THE INITIAL COLD ADVECTION WILL
REMAIN WEST OF THE HUDSON RIVER VALLEY WITH TEMPERATURES OVERNIGHT
REMAINING ABOVE FREEZING FOR A GOOD PORTION OF THE REGION. THE
EXCEPTION TO THIS WILL BE FOR PORTIONS OF THE DACKS. LAKE ONTARIO
CONTRIBUTION INCREASES A BIT...ALBEIT MARGINALLY...TO WARRANT
CHANCE POPS FOR RAIN/SNOW SHOWERS TRANSITIONING TO SNOW SHOWER
OVERNIGHT.
DUE TO A RELATIVELY MILDER START TO THE DAY TUESDAY...TEMPERATURES
FOR THE REGION SHOULD ONCE AGAIN CLIMB ABOVE THE FREEZING WITH MID
40S EXPECTED FOR THE MID HUDSON RIVER VALLEY AND NW CT. CYCLONIC
FLOW REMAINS OVER LAKE ONTARIO AND THE DACKS WITH A VEERING WIND
PROFILE TO TAKE WHAT BANDS OF LAKE EFFECT ACTIVITY FURTHER SOUTH.
SECONDARY COLD FRONT IS EXPECTED TO CLEAR THE REGION LATE TUESDAY
AFTERNOON WITH 850MB TEMPS EXPECTED TO PLUNGE BACK BELOW -10C FOR
THE ENTIRE CWA. THERE WILL BE A WINDOW OF OPPORTUNITY FOR A BRIEF
ORGANIZED LAKE EFFECT WITH CLIMBING INVERSION HEIGHTS TUESDAY
EVENING BEFORE FALLING ONCE AGAIN OVERNIGHT. AT THIS POINT...SEEMS
ACCUMULATIONS WILL BE LIMITED AND ISOLATED WITH GENERALLY AROUND 1
INCH. AS UPPER TROUGH SLIDES EAST OF THE REGION...INVERSION
HEIGHTS DROP QUICKLY AS DOES THE DRY AIR ADVECTION ACROSS NY
STATE.
A NARROW SURFACE RIDGE IS EXPECTED ACROSS THE REGION DESPITE
ANOTHER SHORT WAVE MOVING ACROSS THE NORTHERN TIER OF NY AND NEW
ENGLAND. WITH LIMITED MOISTURE...WE WILL KEEP SKIES PTCLOUDY AND
NO MENTION OF PRECIP. NEAR SEASONABLE TEMPERATURES ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD WILL START OUT WITH A RIDGE MOVING ACROSS THE REGION AT
THE SURFACE WITH THE FLOW ALOFT FLATTENING. THE MODELS ARE IN FAIRLY
GOOD AGREEMENT WITH THE LONGWAVE PATTERN...HOWEVER THERE ARE
DIFFERENCES IN THE TIMING AND TRACK OF THE SOUTHERN STREAM SYSTEM
WHICH ORIGINATES OVER THE SOUTHERN PLAINS AND HEADS OUR WAY LATE IN
THE WEEK. THERE IS A QUESTION OF HOW MUCH INTERACTION THERE WILL BE
WITH THE NORTHERN STREAM. AT THIS TIME...THIS SYSTEM IS EXPECTED TO
PASS TO SOUTH BRINGING THE CHANCES FOR PRECIPITATION TO THE AREA
THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL CONTINUE TO RUN ABOVE
NORMAL WITH THE LONGWAVE PATTERN KEEPING THE COLDER AIR TO OUR NORTH
THROUGH THE WORK WEEK. INDICATIONS ARE NORTHERN STREAM ENERGY WILL
DIVE INTO THE NORTHERN PLAINS CAUSING A TROUGH TO DIG OVER THE
EASTERN UNITED STATES OVER THE WEEKEND RETURNING MORE SEASONABLE AIR
TO THE REGION.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
CONDITIONS WILL REMAIN MAINLY IFR FOR VSBYS AND CIGS THROUGH THIS
EVENING...ALTHOUGH IT MAY TAKE ANOTHER HOUR OR TWO TO DROP INTO
IFR RANGE AT KGFL WHERE SOME DRIER LOW LEVEL AIR PERSISTS. EXPECT
MAINLY IFR CONDITIONS OVERNIGHT...LIFTING INTO MVFR TOWARD
OR AROUND DAYBREAK. CONDITIONS SHOULD IMPROVE TO VFR BY MID
MORNING TUESDAY.
AS FOR PRECIPITATION...AREAS OF DRIZZLE WILL CONTINUE THROUGH MID
AFTERNOON. THEN...LIGHT TO MODERATE RAIN SHOULD DEVELOP FROM W TO
E DURING THE MID TO LATE AFTERNOON...BEFORE ENDING FROM SW TO NE
THIS EVENING. ISOLATED RAIN SHOWERS MAY PERSIST UNTIL LATE TONIGHT.
WINDS WILL REMAIN LIGHT...MAINLY FROM THE SE TO S AT 5-10 KT BY
LATE AFTERNOON THROUGH OVERNIGHT. HOWEVER...A PERIOD OF LIGHT
NORTH WINDS MAY CONTINUE AT KPOU...AND POSSIBLY KGFL THROUGH MID
AFTERNOON UNTIL THE LOW LEVEL GRADIENT TIGHTENS. EXPECT WINDS TO
SHIFT INTO THE SW...THEN W TUE MORNING...AT 5-10 KT...ALTHOUGH
SOME GUSTS OF UP TO 20 KT WILL BE POSSIBLE.
LOW LEVEL WIND SHEAR IS LIKELY THROUGH EARLY TONIGHT...AS SFC
WINDS REMAIN LIGHT FROM THE SE AT LESS THAN 8 KT...WHILE WINDS
AROUND 2000 FT AGL INCREASE FROM THE S TO 30-40 KT.
OUTLOOK...
TUE-WED...VFR. NO SIG WX.
THU...MAINLY VFR. CHC -RA/-SN BY LATE IN THE AFTERNOON.
THU NIGHT-SAT..VFR/MVFR. CHC -SHSN/-SHRA.
&&
.HYDROLOGY...
A STORM SYSTEM WILL BRING MIXED PRECIPITATION CHANGING TO RAIN
TODAY. A QUICK SHOT OF MODERATE TO HEAVY RAIN IS POSSIBLE THIS
AFTERNOON WITH A COLD FRONT AS QPF VALUES ARE EXPECTED TO BE BETWEEN
ONE QUARTER TO ONE HALF INCH WITH LOCALIZED AMOUNTS AROUND AN INCH
POSSIBLE INTO THE HIGHER TERRAIN OF THE CATSKILLS...SOUTHERN VERMONT
AND BERKSHIRES.
WE MEASURED THE GROUND FROZEN TO A DEPTH OF 14 INCHES HERE AT THE
OFFICE ON SUNDAY. SOME LOCALIZED POOR DRAINAGE...URBAN AND SMALL
STREAM FLOODING MAY BE POSSIBLE LATER MONDAY DUE TO ENHANCED RUNOFF
FROM RAIN AND MELT ON FROZEN GROUND.
SOME SIGNIFICANT RISES ON MAIN STEM RIVERS ARE POSSIBLE MONDAY INTO
TUESDAY...BUT LARGER RIVER FLOODING IS NOT EXPECTED AT THIS TIME.
RISES WOULD BE ENOUGH TO BREAK UP WHAT RIVER ICE IS IN PLACE BUT ICE
IS NOT THICK ENOUGH TO CAUSE SIGNIFICANT ICE JAM PROBLEMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
CTZ001-013.
NY...FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
NYZ033-041>043-082>084.
MA...FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MAZ001-025.
VT...FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
VTZ013>015.
&&
$$
SYNOPSIS...KL/BGM
NEAR TERM...GJM/KL/BGM
SHORT TERM...BGM
LONG TERM...IAA
AVIATION...KL/IAA
HYDROLOGY...SND/BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
1225 PM EST MON JAN 23 2012
.SYNOPSIS...
AFTER SOME LIGHT ICING CONDITIONS THROUGH EARLY THIS AFTERNOON
ACROSS AREAS NORTH AND EAST OF ALBANY...TEMPERATURES WILL CLIMB TO
ABOVE FREEZING AND PRODUCE MAINLY RAIN SHOWERS THAT WILL ACCOMPANY A
FRONTAL BOUNDARY AS IT CROSSES THE REGION. SOMEWHAT COOLER AIR WILL
FILTER IN FOR TUESDAY WITH SOME LAKE EFFECT SNOW DOWNWIND OF LAKE
ONTARIO. THERE WILL BE TRANQUIL CONDITIONS FOR THE MID WEEK AS A
RIDGE OF HIGH PRESSURE TRACKS ACROSS THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD TEMPS PERSIST ACROSS WESTERN NEW ENGLAND ZONES SO HAVE EXTENDED
THE FREEZING RAIN ADVISORY THERE THROUGH 200 PM. TEMPS IN THE
IMMEDIATE CONNECTICUT VALLEY OF EASTERN WINDHAM COUNTY MAY STILL BE
BELOW FREEZING AT THAT TIME...BUT WILL WAIT UNTIL THEN TO DECIDE ON
ANY ADDITIONAL EXTENSIONS OF THE ADVISORY. ELSEWHWERE ADVISORIES
HAVE BEEND ALLOWED TO EXPITE ACROSS THE MOHAWK/SCHOHARIE VALLEYS...
EASTERN CATSKILLS...CAPITAL DISTRICT AND TACONICS. HAVE CANCELLED
THE ADVISORY ACROSS ALL OF HERKIMER COUNTY SINCE MESONET OBS
INDICATE THE FAR WESTERN ADIRONDACKS HAVE WARMED TO ABOVE FREEZING.
THE ADVISORY CONTINUES FOR THE REST OF THE ADIRONDACKS AND LAKE
GEORGE REGION THROUGH 200 PM.
****PREVIOUS DISCUSSION****
AS OF 11 AM EST...HAVE DROPPED FREEZING RAIN ADVISORY FOR THE MID
HUDSON VALLEY REGION...WHERE TEMPS HAVE WARMED ABOVE FREEZING.
ELSEWHERE...HAVE KEPT FREEZING RAIN ADVISORIES IN PLACE...ALTHOUGH
TEMPS NOW RISING TO NEAR OR ABOVE FREEZING ACROSS THE EASTERN
CATSKILLS...SCHOHARIE VALLEY...AND THE CAPITAL REGION.
FURTHER N AND E...COLD AIR HANGING TOUGH...FROM SE VT INTO THE
BERKSHIRES AND SOUTH INTO EASTERN LITCHFIELD COUNTY...WHERE
DRIZZLE PERSISTS. WE MAY NEED TO EXTEND THE ADVISORIES FOR
PORTIONS OF THESE AREAS...AS COLD AIR MAY REMAIN TOUGH TO
DISLODGE.
STEADIER RAIN SHOULD DEVELOP FROM W TO E DURING THE MID TO LATE
AFTERNOON HOURS. THERE IS SOME POSSIBILITY THAT POCKETS OF
SUBFREEZING TEMPS PERSIST IN PORTIONS OF SE VT AND/OR THE
BERKSHIRES WHEN THIS ARRIVES...SO WILL NEED TO MONITOR CLOSELY.
PREVIOUS DISCUSSION FOLLOWS...
AS OF 6 AM...DRIZZLE IS BEGINNING TO SHOW UP ACROSS THE TRI-STATE
REGION AND MID-HUDSON VALLEY INCLUDING OUR RADAR IN VCP31.
TEMPERATURES VARY BUT THEY DO HOVER AROUND THE FREEZING MARK WHERE
DRIZZLE IS BEING REPORTED. NCEP MODEL SUITE ALONG WITH THE
RUC13/HRRR NOT DOING THAT WELL...HOWEVER...THEY DO SUGGEST THIS
AREA OF DRIZZLE AND SATURATING BOUNDARY LAYER ADVANCES SLOWLY
NORTH THIS MORNING. WET BULB PROFILES ARE STILL BELOW FREEZING SO
WE WILL CONTINUE WITH THE ADVISORY AND REFRESH THE GRIDS AND
HOURLY TEMPS/DEWPTS. PER THE 06Z MOS AND HOURLY LAV/LAMP...MOST
AREAS WILL CLIMB ABOVE FREEZING AROUND THE NOON HOUR.
PREV DISC...
VERY CHALLENGING NEAR TERM FORECAST AS FZDZ HAS NOT
MATERIALIZED AT THIS TIME. PER METARS...THE CIGS REMAIN RATHER
HIGH AND DEWPOINT DEPRESSIONS ARE 5 DEGREES OR GREATER. WE DID
RECEIVE A REPORT OF FLURRIES IN LITCHFIELD COUNTY AND THIS CAN
ALSO BE CONFIRMED WITH SEVERAL METARS ACROSS THE NYC METRO AREA
REPORTING LIGHT SNOW. THIS MAY BE DUE TO THE OCEANIC EFFECT ADDING
ENOUGH NUCLEI TO RESULT IN THOSE OBS OF LIGHT SNOW. THE FORECAST
SOUNDINGS ACROSS OUR REGION STILL SUGGEST THE BOUNDARY LAYER WILL
MOISTEN UP BELOW THE -10C ISOTHERM INCLUDING THE SHEAR PROFILES
FOR SOME DRIZZLE FORMATION. RUC13 FORECAST SOUNDINGS DELAY THE
ONSET OF MOISTURE UNTIL THE 12-15Z TIME FRAME. BY THAT
TIME...TEMPERATURES ARE BEGINNING TO CLIMB TO AT OR ABOVE FREEZING
ALONG AND SOUTH OF I90. THE COLDER AIR IS EXPECTED TO REMAIN IN
PLACE LONGER ACROSS THE DACKS...LAKE GEORGE SARATOGA REGION AND
SOUTHERN VERMONT UNTIL ABOUT THE NOON HOUR. THE ADVISORY LOOKS
GOOD AT THIS TIME WITH NO CHANGES EXPECTED.
POTENT SHORT WAVE TRACKING NORTHWARD ALONG THE MISSISSIPPI RIVER
VALLEY INTO THE GREAT LAKES REGION WILL SEND A COLD FRONT EASTWARD
THIS AFTERNOON. A BAND OF BKN SHOWERS IS EXPECTED AND WE WILL
PLACE CATEGORICAL POPS FOR THE ENTIRE REGION. TIMING OF THIS FRONT
APPEARS TO BE AOA 21Z. AS FOR CONVECTIVE POTENTIAL /IE
THUNDER/...THE SHOWALTER INDEX IS EXPECTED TO DROP TOWARD 0C FOR
PORTIONS OF THE REGION WITH THE BEST UPPER SUPPORT FOR THE WESTERN
MOHAWK VALLEY AND DACKS. WHILE WE WILL NOT INCLUDE THUNDER...WOULD
NOT TOTALLY RULE OUT A RUMBLE OF THUNDER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
WITH FROPA...DRY SLOT QUICKLY APPROACHES THIS EARLY EVENING. SOME
LINGERING UPSLOPE SHOWERS ARE EXPECTED BUT THIS TOO SHOULD
DECREASE THROUGH TONIGHT. SEEMS THE INITIAL COLD ADVECTION WILL
REMAIN WEST OF THE HUDSON RIVER VALLEY WITH TEMPERATURES OVERNIGHT
REMAINING ABOVE FREEZING FOR A GOOD PORTION OF THE REGION. THE
EXCEPTION TO THIS WILL BE FOR PORTIONS OF THE DACKS. LAKE ONTARIO
CONTRIBUTION INCREASES A BIT...ALBEIT MARGINALLY...TO WARRANT
CHANCE POPS FOR RAIN/SNOW SHOWERS TRANSITIONING TO SNOW SHOWER
OVERNIGHT.
DUE TO A RELATIVELY MILDER START TO THE DAY TUESDAY...TEMPERATURES
FOR THE REGION SHOULD ONCE AGAIN CLIMB ABOVE THE FREEZING WITH MID
40S EXPECTED FOR THE MID HUDSON RIVER VALLEY AND NW CT. CYCLONIC
FLOW REMAINS OVER LAKE ONTARIO AND THE DACKS WITH A VEERING WIND
PROFILE TO TAKE WHAT BANDS OF LAKE EFFECT ACTIVITY FURTHER SOUTH.
SECONDARY COLD FRONT IS EXPECTED TO CLEAR THE REGION LATE TUESDAY
AFTERNOON WITH 850MB TEMPS EXPECTED TO PLUNGE BACK BELOW -10C FOR
THE ENTIRE CWA. THERE WILL BE A WINDOW OF OPPORTUNITY FOR A BRIEF
ORGANIZED LAKE EFFECT WITH CLIMBING INVERSION HEIGHTS TUESDAY
EVENING BEFORE FALLING ONCE AGAIN OVERNIGHT. AT THIS POINT...SEEMS
ACCUMULATIONS WILL BE LIMITED AND ISOLATED WITH GENERALLY AROUND 1
INCH. AS UPPER TROUGH SLIDES EAST OF THE REGION...INVERSION
HEIGHTS DROP QUICKLY AS DOES THE DRY AIR ADVECTION ACROSS NY
STATE.
A NARROW SURFACE RIDGE IS EXPECTED ACROSS THE REGION DESPITE
ANOTHER SHORT WAVE MOVING ACROSS THE NORTHERN TIER OF NY AND NEW
ENGLAND. WITH LIMITED MOISTURE...WE WILL KEEP SKIES PTCLOUDY AND
NO MENTION OF PRECIP. NEAR SEASONABLE TEMPERATURES ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD WILL START OUT WITH A RIDGE MOVING ACROSS THE REGION AT
THE SURFACE WITH THE FLOW ALOFT FLATTENING. THE MODELS ARE IN FAIRLY
GOOD AGREEMENT WITH THE LONGWAVE PATTERN...HOWEVER THERE ARE
DIFFERENCES IN THE TIMING AND TRACK OF THE SOUTHERN STREAM SYSTEM
WHICH ORIGINATES OVER THE SOUTHERN PLAINS AND HEADS OUR WAY LATE IN
THE WEEK. THERE IS A QUESTION OF HOW MUCH INTERACTION THERE WILL BE
WITH THE NORTHERN STREAM. AT THIS TIME...THIS SYSTEM IS EXPECTED TO
PASS TO SOUTH BRINGING THE CHANCES FOR PRECIPITATION TO THE AREA
THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL CONTINUE TO RUN ABOVE
NORMAL WITH THE LONGWAVE PATTERN KEEPING THE COLDER AIR TO OUR NORTH
THROUGH THE WORK WEEK. INDICATIONS ARE NORTHERN STREAM ENERGY WILL
DIVE INTO THE NORTHERN PLAINS CAUSING A TROUGH TO DIG OVER THE
EASTERN UNITED STATES OVER THE WEEKEND RETURNING MORE SEASONABLE AIR
TO THE REGION.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
CEILINGS HAVE LOWERED TO MVFR AS THE LOWEST LEVELS OF THE ATMOSPHERE
HAVE FINALLY MOISTEN UP. HAVE HAD REPORTS OF LIGHT DRIZZLE AND
TEMPERATURES ARE AT OR JUST BELOW FREEZING SO WE HAVE FREEZING
DRIZZLE. TEMPERATURES WILL RISE TO ABOVE THE FREEZING MARK BEFORE
THE STEADIER AND HEAVIER PRECIPITATION MOVES IN THIS AFTERNOON.
WIDESPREAD IFR CONDITIONS WILL DEVELOP. THE STEADY PRECIPITATION
WILL MOVE OFF TO THE EAST DURING THE EVENING...HOWEVER IFR
CONDITIONS ARE EXPECTED TO LINGER INTO THE EARLY MORNING HOURS. AN
IMPROVEMENT TO MVFR IS EXPECTED BEFORE SUNRISE WITH VFR DEVELOPING
AT KPOU.
OUTLOOK...
MON NIGHT...MVFR/IFR...IMPROVING TO MVFR/VFR. RAIN TAPERING OFF TO
SCATTERED SHOWERS.
TUE-WED...VFR. NO SIG WX.
THU...MAINLY VFR. CHC -RA/-SN BY LATE IN THE AFTERNOON.
THU NIGHT-FRI..VFR/MVFR. CHC -SHSN/-SHRA.
&&
.HYDROLOGY...
A STORM SYSTEM WILL BRING MIXED PRECIPITATION CHANGING TO RAIN
TODAY. A QUICK SHOT OF MODERATE TO HEAVY RAIN IS POSSIBLE THIS
AFTERNOON WITH A COLD FRONT AS QPF VALUES ARE EXPECTED TO BE BETWEEN
ONE QUARTER TO ONE HALF INCH WITH LOCALIZED AMOUNTS AROUND AN INCH
POSSIBLE INTO THE HIGHER TERRAIN OF THE CATSKILLS...SOUTHERN VERMONT
AND BERKSHIRES.
WE MEASURED THE GROUND FROZEN TO A DEPTH OF 14 INCHES HERE AT THE
OFFICE ON SUNDAY. SOME LOCALIZED POOR DRAINAGE...URBAN AND SMALL
STREAM FLOODING MAY BE POSSIBLE LATER MONDAY DUE TO ENHANCED RUNOFF
FROM RAIN AND MELT ON FROZEN GROUND.
SOME SIGNIFICANT RISES ON MAIN STEM RIVERS ARE POSSIBLE MONDAY INTO
TUESDAY...BUT LARGER RIVER FLOODING IS NOT EXPECTED AT THIS TIME.
RISES WOULD BE ENOUGH TO BREAK UP WHAT RIVER ICE IS IN PLACE BUT ICE
IS NOT THICK ENOUGH TO CAUSE SIGNIFICANT ICE JAM PROBLEMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL 2 PM EST TODAY FOR CTZ001-013.
NY...FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
NYZ033-041>043-082>084.
MA...FREEZING RAIN ADVISORY UNTIL 2 PM EST TODAY FOR MAZ001-025.
VT...FREEZING RAIN ADVISORY UNTIL 2 PM EST TODAY FOR VTZ013>015.
&&
$$
SYNOPSIS...GJM/KL/BGM
NEAR TERM...GJM/KL/BGM
SHORT TERM...BGM
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...SND/BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
1057 AM EST MON JAN 23 2012
.SYNOPSIS...
AFTER SOME LIGHT ICING CONDITIONS THIS MORNING...TEMPERATURES
WILL CLIMB ABOVE FREEZING THIS AFTERNOON FOR MAINLY RAIN SHOWERS
THAT WILL ACCOMPANY THE FRONTAL BOUNDARY. SOMEWHAT COOLER AIR WILL
FILTER IN FOR TUESDAY WITH SOME LAKE EFFECT SNOW DOWNWIND OF LAKE
ONTARIO. TRANQUIL CONDITIONS FOR THE MID WEEK AS A RIDGE OF HIGH
PRESSURE TRACKS ACROSS THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 11 AM EST...HAVE DROPPED FREEZING RAIN ADVISORY FOR THE MID
HUDSON VALLEY REGION...WHERE TEMPS HAVE WARMED ABOVE FREEZING.
ELSEWHERE...HAVE KEPT FREEZING RAIN ADVISORIES IN PLACE...ALTHOUGH
TEMPS NOW RISING TO NEAR OR ABOVE FREEZING ACROSS THE EASTERN
CATSKILLS...SCHOHARIE VALLEY...AND THE CAPITAL REGION.
FURTHER N AND E...COLD AIR HANGING TOUGH...FROM SE VT INTO THE
BERKSHIRES AND SOUTH INTO EASTERN LITCHFIELD COUNTY...WHERE
DRIZZLE PERSISTS. WE MAY NEED TO EXTEND THE ADVISORIES FOR
PORTIONS OF THESE AREAS...AS COLD AIR MAY REMAIN TOUGH TO
DISLODGE.
STEADIER RAIN SHOULD DEVELOP FROM W TO E DURING THE MID TO LATE
AFTERNOON HOURS. THERE IS SOME POSSIBILITY THAT POCKETS OF
SUBFREEZING TEMPS PERSIST IN PORTIONS OF SE VT AND/OR THE
BERKSHIRES WHEN THIS ARRIVES...SO WILL NEED TO MONITOR CLOSELY.
PREVIOUS DISCUSSION FOLLOWS...
AS OF 6 AM...DRIZZLE IS BEGINNING TO SHOW UP ACROSS THE TRI-STATE
REGION AND MID-HUDSON VALLEY INCLUDING OUR RADAR IN VCP31.
TEMPERATURES VARY BUT THEY DO HOVER AROUND THE FREEZING MARK WHERE
DRIZZLE IS BEING REPORTED. NCEP MODEL SUITE ALONG WITH THE
RUC13/HRRR NOT DOING THAT WELL...HOWEVER...THEY DO SUGGEST THIS
AREA OF DRIZZLE AND SATURATING BOUNDARY LAYER ADVANCES SLOWLY
NORTH THIS MORNING. WET BULB PROFILES ARE STILL BELOW FREEZING SO
WE WILL CONTINUE WITH THE ADVISORY AND REFRESH THE GRIDS AND
HOURLY TEMPS/DEWPTS. PER THE 06Z MOS AND HOURLY LAV/LAMP...MOST
AREAS WILL CLIMB ABOVE FREEZING AROUND THE NOON HOUR.
PREV DISC...
VERY CHALLENGING NEAR TERM FORECAST AS FZDZ HAS NOT
MATERIALIZED AT THIS TIME. PER METARS...THE CIGS REMAIN RATHER
HIGH AND DEWPOINT DEPRESSIONS ARE 5 DEGREES OR GREATER. WE DID
RECEIVE A REPORT OF FLURRIES IN LITCHFIELD COUNTY AND THIS CAN
ALSO BE CONFIRMED WITH SEVERAL METARS ACROSS THE NYC METRO AREA
REPORTING LIGHT SNOW. THIS MAY BE DUE TO THE OCEANIC EFFECT ADDING
ENOUGH NUCLEI TO RESULT IN THOSE OBS OF LIGHT SNOW. THE FORECAST
SOUNDINGS ACROSS OUR REGION STILL SUGGEST THE BOUNDARY LAYER WILL
MOISTEN UP BELOW THE -10C ISOTHERM INCLUDING THE SHEAR PROFILES
FOR SOME DRIZZLE FORMATION. RUC13 FORECAST SOUNDINGS DELAY THE
ONSET OF MOISTURE UNTIL THE 12-15Z TIME FRAME. BY THAT
TIME...TEMPERATURES ARE BEGINNING TO CLIMB TO AT OR ABOVE FREEZING
ALONG AND SOUTH OF I90. THE COLDER AIR IS EXPECTED TO REMAIN IN
PLACE LONGER ACROSS THE DACKS...LAKE GEORGE SARATOGA REGION AND
SOUTHERN VERMONT UNTIL ABOUT THE NOON HOUR. THE ADVISORY LOOKS
GOOD AT THIS TIME WITH NO CHANGES EXPECTED.
POTENT SHORT WAVE TRACKING NORTHWARD ALONG THE MISSISSIPPI RIVER
VALLEY INTO THE GREAT LAKES REGION WILL SEND A COLD FRONT EASTWARD
THIS AFTERNOON. A BAND OF BKN SHOWERS IS EXPECTED AND WE WILL
PLACE CATEGORICAL POPS FOR THE ENTIRE REGION. TIMING OF THIS FRONT
APPEARS TO BE AOA 21Z. AS FOR CONVECTIVE POTENTIAL /IE
THUNDER/...THE SHOWALTER INDEX IS EXPECTED TO DROP TOWARD 0C FOR
PORTIONS OF THE REGION WITH THE BEST UPPER SUPPORT FOR THE WESTERN
MOHAWK VALLEY AND DACKS. WHILE WE WILL NOT INCLUDE THUNDER...WOULD
NOT TOTALLY RULE OUT A RUMBLE OF THUNDER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
WITH FROPA...DRY SLOT QUICKLY APPROACHES THIS EARLY EVENING. SOME
LINGERING UPSLOPE SHOWERS ARE EXPECTED BUT THIS TOO SHOULD
DECREASE THROUGH TONIGHT. SEEMS THE INITIAL COLD ADVECTION WILL
REMAIN WEST OF THE HUDSON RIVER VALLEY WITH TEMPERATURES OVERNIGHT
REMAINING ABOVE FREEZING FOR A GOOD PORTION OF THE REGION. THE
EXCEPTION TO THIS WILL BE FOR PORTIONS OF THE DACKS. LAKE ONTARIO
CONTRIBUTION INCREASES A BIT...ALBEIT MARGINALLY...TO WARRANT
CHANCE POPS FOR RAIN/SNOW SHOWERS TRANSITIONING TO SNOW SHOWER
OVERNIGHT.
DUE TO A RELATIVELY MILDER START TO THE DAY TUESDAY...TEMPERATURES
FOR THE REGION SHOULD ONCE AGAIN CLIMB ABOVE THE FREEZING WITH MID
40S EXPECTED FOR THE MID HUDSON RIVER VALLEY AND NW CT. CYCLONIC
FLOW REMAINS OVER LAKE ONTARIO AND THE DACKS WITH A VEERING WIND
PROFILE TO TAKE WHAT BANDS OF LAKE EFFECT ACTIVITY FURTHER SOUTH.
SECONDARY COLD FRONT IS EXPECTED TO CLEAR THE REGION LATE TUESDAY
AFTERNOON WITH 850MB TEMPS EXPECTED TO PLUNGE BACK BELOW -10C FOR
THE ENTIRE CWA. THERE WILL BE A WINDOW OF OPPORTUNITY FOR A BRIEF
ORGANIZED LAKE EFFECT WITH CLIMBING INVERSION HEIGHTS TUESDAY
EVENING BEFORE FALLING ONCE AGAIN OVERNIGHT. AT THIS POINT...SEEMS
ACCUMULATIONS WILL BE LIMITED AND ISOLATED WITH GENERALLY AROUND 1
INCH. AS UPPER TROUGH SLIDES EAST OF THE REGION...INVERSION
HEIGHTS DROP QUICKLY AS DOES THE DRY AIR ADVECTION ACROSS NY
STATE.
A NARROW SURFACE RIDGE IS EXPECTED ACROSS THE REGION DESPITE
ANOTHER SHORT WAVE MOVING ACROSS THE NORTHERN TIER OF NY AND NEW
ENGLAND. WITH LIMITED MOISTURE...WE WILL KEEP SKIES PTCLOUDY AND
NO MENTION OF PRECIP. NEAR SEASONABLE TEMPERATURES ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD WILL START OUT WITH A RIDGE MOVING ACROSS THE REGION AT
THE SURFACE WITH THE FLOW ALOFT FLATTENING. THE MODELS ARE IN FAIRLY
GOOD AGREEMENT WITH THE LONGWAVE PATTERN...HOWEVER THERE ARE
DIFFERENCES IN THE TIMING AND TRACK OF THE SOUTHERN STREAM SYSTEM
WHICH ORIGINATES OVER THE SOUTHERN PLAINS AND HEADS OUR WAY LATE IN
THE WEEK. THERE IS A QUESTION OF HOW MUCH INTERACTION THERE WILL BE
WITH THE NORTHERN STREAM. AT THIS TIME...THIS SYSTEM IS EXPECTED TO
PASS TO SOUTH BRINGING THE CHANCES FOR PRECIPITATION TO THE AREA
THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL CONTINUE TO RUN ABOVE
NORMAL WITH THE LONGWAVE PATTERN KEEPING THE COLDER AIR TO OUR NORTH
THROUGH THE WORK WEEK. INDICATIONS ARE NORTHERN STREAM ENERGY WILL
DIVE INTO THE NORTHERN PLAINS CAUSING A TROUGH TO DIG OVER THE
EASTERN UNITED STATES OVER THE WEEKEND RETURNING MORE SEASONABLE AIR
TO THE REGION.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
CEILINGS HAVE LOWERED TO MVFR AS THE LOWEST LEVELS OF THE ATMOSPHERE
HAVE FINALLY MOISTEN UP. HAVE HAD REPORTS OF LIGHT DRIZZLE AND
TEMPERATURES ARE AT OR JUST BELOW FREEZING SO WE HAVE FREEZING
DRIZZLE. TEMPERATURES WILL RISE TO ABOVE THE FREEZING MARK BEFORE
THE STEADIER AND HEAVIER PRECIPITATION MOVES IN THIS AFTERNOON.
WIDESPREAD IFR CONDITIONS WILL DEVELOP. THE STEADY PRECIPITATION
WILL MOVE OFF TO THE EAST DURING THE EVENING...HOWEVER IFR
CONDITIONS ARE EXPECTED TO LINGER INTO THE EARLY MORNING HOURS. AN
IMPROVEMENT TO MVFR IS EXPECTED BEFORE SUNRISE WITH VFR DEVELOPING
AT KPOU.
OUTLOOK...
MON NIGHT...MVFR/IFR...IMPROVING TO MVFR/VFR. RAIN TAPERING OFF TO
SCATTERED SHOWERS.
TUE-WED...VFR. NO SIG WX.
THU...MAINLY VFR. CHC -RA/-SN BY LATE IN THE AFTERNOON.
THU NIGHT-FRI..VFR/MVFR. CHC -SHSN/-SHRA.
&&
.HYDROLOGY...
A STORM SYSTEM WILL BRING MIXED PRECIPITATION CHANGING TO RAIN
TODAY. A QUICK SHOT OF MODERATE TO HEAVY RAIN IS POSSIBLE THIS
AFTERNOON WITH A COLD FRONT AS QPF VALUES ARE EXPECTED TO BE BETWEEN
ONE QUARTER TO ONE HALF INCH WITH LOCALIZED AMOUNTS AROUND AN INCH
POSSIBLE INTO THE HIGHER TERRAIN OF THE CATSKILLS...SOUTHERN VERMONT
AND BERKSHIRES.
WE MEASURED THE GROUND FROZEN TO A DEPTH OF 14 INCHES HERE AT THE
OFFICE ON SUNDAY. SOME LOCALIZED POOR DRAINAGE...URBAN AND SMALL
STREAM FLOODING MAY BE POSSIBLE LATER MONDAY DUE TO ENHANCED RUNOFF
FROM RAIN AND MELT ON FROZEN GROUND.
SOME SIGNIFICANT RISES ON MAIN STEM RIVERS ARE POSSIBLE MONDAY INTO
TUESDAY...BUT LARGER RIVER FLOODING IS NOT EXPECTED AT THIS TIME.
RISES WOULD BE ENOUGH TO BREAK UP WHAT RIVER ICE IS IN PLACE BUT ICE
IS NOT THICK ENOUGH TO CAUSE SIGNIFICANT ICE JAM PROBLEMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR CTZ001-013.
NY...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ039-040-
047>054-058-061-063-066.
FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
NYZ032-033-038-041>043-082>084.
MA...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR MAZ001-025.
VT...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR VTZ013>015.
&&
$$
SYNOPSIS...KL/BGM
NEAR TERM...KL/BGM
SHORT TERM...BGM
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...SND/BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
642 AM EST MON JAN 23 2012
.SYNOPSIS...
MOISTURE WILL CONTINUE TO INCREASE AND PROVIDE THE
REGION WITH SOME LIGHT ICING CONDITIONS THIS MORNING. TEMPERATURES
WILL CLIMB ABOVE FREEZING THIS AFTERNOON FOR MAINLY RAIN SHOWERS
THAT WILL ACCOMPANY THE FRONTAL BOUNDARY. SOMEWHAT COOLER AIR WILL
FILTER IN FOR TUESDAY WITH SOME LAKE EFFECT SNOW DOWNWIND OF LAKE
ONTARIO. TRANQUIL CONDITIONS FOR THE MID WEEK AS A RIDGE OF HIGH
PRESSURE TRACKS ACROSS THE AREA.
&&
.NEAR TERM /UNTIL NOON TODAY/...
AS OF 6 AM...DRIZZLE IS BEGINNING TO SHOW UP ACROSS THE TRI-STATE
REGION AND MID-HUDSON VALLEY INCLUDING OUR RADAR IN VCP31.
TEMPERATURES VARY BUT THEY DO HOVER AROUND THE FREEZING MARK WHERE
DRIZZLE IS BEING REPORTED. NCEP MODEL SUITE ALONG WITH THE
RUC13/HRRR NOT DOING THAT WELL...HOWEVER...THEY DO SUGGEST THIS
AREA OF DRIZZLE AND SATURATING BOUNDARY LAYER ADVANCES SLOWLY
NORTH THIS MORNING. WET BULB PROFILES ARE STILL BELOW FREEZING SO
WE WILL CONTINUE WITH THE ADVISORY AND REFRESH THE GRIDS AND
HOURLY TEMPS/DEWPTS. PER THE 06Z MOS AND HOURLY LAV/LAMP...MOST
AREAS WILL CLIMB ABOVE FREEZING AROUND THE NOON HOUR.
PREV DISC...
VERY CHALLENGING NEAR TERM FORECAST AS FZDZ HAS NOT
MATERIALIZED AT THIS TIME. PER METARS...THE CIGS REMAIN RATHER
HIGH AND DEWPOINT DEPRESSIONS ARE 5 DEGREES OR GREATER. WE DID
RECEIVE A REPORT OF FLURRIES IN LITCHFIELD COUNTY AND THIS CAN
ALSO BE CONFIRMED WITH SEVERAL METARS ACROSS THE NYC METRO AREA
REPORTING LIGHT SNOW. THIS MAY BE DUE TO THE OCEANIC EFFECT ADDING
ENOUGH NUCLEI TO RESULT IN THOSE OBS OF LIGHT SNOW. THE FORECAST
SOUNDINGS ACROSS OUR REGION STILL SUGGEST THE BOUNDARY LAYER WILL
MOISTEN UP BELOW THE -10C ISOTHERM INCLUDING THE SHEAR PROFILES
FOR SOME DRIZZLE FORMATION. RUC13 FORECAST SOUNDINGS DELAY THE
ONSET OF MOISTURE UNTIL THE 12-15Z TIME FRAME. BY THAT
TIME...TEMPERATURES ARE BEGINNING TO CLIMB TO AT OR ABOVE FREEZING
ALONG AND SOUTH OF I90. THE COLDER AIR IS EXPECTED TO REMAIN IN
PLACE LONGER ACROSS THE DACKS...LAKE GEORGE SARATOGA REGION AND
SOUTHERN VERMONT UNTIL ABOUT THE NOON HOUR. THE ADVISORY LOOKS
GOOD AT THIS TIME WITH NO CHANGES EXPECTED.
&&
.SHORT TERM /NOON TODAY THROUGH WEDNESDAY/...
POTENT SHORT WAVE TRACKING NORTHWARD ALONG THE MISSISSIPPI RIVER
VALLEY INTO THE GREAT LAKES REGION WILL SEND A COLD FRONT EASTWARD
THIS AFTERNOON. A BAND OF BKN SHOWERS IS EXPECTED AND WE WILL
PLACE CATEGORICAL POPS FOR THE ENTIRE REGION. TIMING OF THIS FRONT
APPEARS TO BE AOA 21Z. AS FOR CONVECTIVE POTENTIAL /IE
THUNDER/...THE SHOWALTER INDEX IS EXPECTED TO DROP TOWARD 0C FOR
PORTIONS OF THE REGION WITH THE BEST UPPER SUPPORT FOR THE WESTERN
MOHAWK VALLEY AND DACKS. WHILE WE WILL NOT INCLUDE THUNDER...WOULD
NOT TOTALLY RULE OUT A RUMBLE OF THUNDER.
WITH FROPA...DRY SLOT QUICKLY APPROACHES THIS EARLY EVENING. SOME
LINGERING UPSLOPE SHOWERS ARE EXPECTED BUT THIS TOO SHOULD
DECREASE THROUGH TONIGHT. SEEMS THE INITIAL COLD ADVECTION WILL
REMAIN WEST OF THE HUDSON RIVER VALLEY WITH TEMPERATURES OVERNIGHT
REMAINING ABOVE FREEZING FOR A GOOD PORTION OF THE REGION. THE
EXCEPTION TO THIS WILL BE FOR PORTIONS OF THE DACKS. LAKE ONTARIO
CONTRIBUTION INCREASES A BIT...ALBEIT MARGINALLY...TO WARRANT
CHANCE POPS FOR RAIN/SNOW SHOWERS TRANSITIONING TO SNOW SHOWER
OVERNIGHT.
DUE TO A RELATIVELY MILDER START TO THE DAY TUESDAY...TEMPERATURES
FOR THE REGION SHOULD ONCE AGAIN CLIMB ABOVE THE FREEZING WITH MID
40S EXPECTED FOR THE MID HUDSON RIVER VALLEY AND NW CT. CYCLONIC
FLOW REMAINS OVER LAKE ONTARIO AND THE DACKS WITH A VEERING WIND
PROFILE TO TAKE WHAT BANDS OF LAKE EFFECT ACTIVITY FURTHER SOUTH.
SECONDARY COLD FRONT IS EXPECTED TO CLEAR THE REGION LATE TUESDAY
AFTERNOON WITH 850MB TEMPS EXPECTED TO PLUNGE BACK BELOW -10C FOR
THE ENTIRE CWA. THERE WILL BE A WINDOW OF OPPORTUNITY FOR A BRIEF
ORGANIZED LAKE EFFECT WITH CLIMBING INVERSION HEIGHTS TUESDAY
EVENING BEFORE FALLING ONCE AGAIN OVERNIGHT. AT THIS POINT...SEEMS
ACCUMULATIONS WILL BE LIMITED AND ISOLATED WITH GENERALLY AROUND 1
INCH. AS UPPER TROUGH SLIDES EAST OF THE REGION...INVERSION
HEIGHTS DROP QUICKLY AS DOES THE DRY AIR ADVECTION ACROSS NY
STATE.
A NARROW SURFACE RIDGE IS EXPECTED ACROSS THE REGION DESPITE
ANOTHER SHORT WAVE MOVING ACROSS THE NORTHERN TIER OF NY AND NEW
ENGLAND. WITH LIMITED MOISTURE...WE WILL KEEP SKIES PTCLOUDY AND
NO MENTION OF PRECIP. NEAR SEASONABLE TEMPERATURES ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD WILL START OUT WITH A RIDGE MOVING ACROSS THE REGION AT
THE SURFACE WITH THE FLOW ALOFT FLATTENING. THE MODELS ARE IN FAIRLY
GOOD AGREEMENT WITH THE LONGWAVE PATTERN...HOWEVER THERE ARE
DIFFERENCES IN THE TIMING AND TRACK OF THE SOUTHERN STREAM SYSTEM
WHICH ORIGINATES OVER THE SOUTHERN PLAINS AND HEADS OUR WAY LATE IN
THE WEEK. THERE IS A QUESTION OF HOW MUCH INTERACTION THERE WILL BE
WITH THE NORTHERN STREAM. AT THIS TIME...THIS SYSTEM IS EXPECTED TO
PASS TO SOUTH BRINGING THE CHANCES FOR PRECIPITATION TO THE AREA
THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL CONTINUE TO RUN ABOVE
NORMAL WITH THE LONGWAVE PATTERN KEEPING THE COLDER AIR TO OUR NORTH
THROUGH THE WORK WEEK. INDICATIONS ARE NORTHERN STREAM ENERGY WILL
DIVE INTO THE NORTHERN PLAINS CAUSING A TROUGH TO DIG OVER THE
EASTERN UNITED STATES OVER THE WEEKEND RETURNING MORE SEASONABLE AIR
TO THE REGION.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
CEILINGS HAVE LOWERED TO MVFR AS THE LOWEST LEVELS OF THE ATMOSPHERE
HAVE FINALLY MOISTEN UP. HAVE HAD REPORTS OF LIGHT DRIZZLE AND
TEMPERATURES ARE AT OR JUST BELOW FREEZING SO WE HAVE FREEZING
DRIZZLE. TEMPERATURES WILL RISE TO ABOVE THE FREEZING MARK BEFORE
THE STEADIER AND HEAVIER PRECIPITATION MOVES IN THIS AFTERNOON.
WIDESPREAD IFR CONDITIONS WILL DEVELOP. THE STEADY PRECIPITATION
WILL MOVE OFF TO THE EAST DURING THE EVENING...HOWEVER IFR
CONDITIONS ARE EXPECTED TO LINGER INTO THE EARLY MORNING HOURS. AN
IMPROVEMENT TO MVFR IS EXPECTED BEFORE SUNRISE WITH VFR DEVELOPING
AT KPOU.
OUTLOOK...
MON NIGHT...MVFR/IFR...IMPROVING TO MVFR/VFR. RAIN TAPERING OFF TO
SCATTERED SHOWERS.
TUE-WED...VFR. NO SIG WX.
THU...MAINLY VFR. CHC -RA/-SN BY LATE IN THE AFTERNOON.
THU NIGHT-FRI..VFR/MVFR. CHC -SHSN/-SHRA.
&&
.HYDROLOGY...
A STORM SYSTEM WILL BRING MIXED PRECIPITATION CHANGING TO RAIN
TODAY. A QUICK SHOT OF MODERATE TO HEAVY RAIN IS POSSIBLE THIS
AFTERNOON WITH A COLD FRONT AS QPF VALUES ARE EXPECTED TO BE BETWEEN
ONE QUARTER TO ONE HALF INCH WITH LOCALIZED AMOUNTS AROUND AN INCH
POSSIBLE INTO THE HIGHER TERRAIN OF THE CATSKILLS...SOUTHERN VERMONT
AND BERKSHIRES.
WE MEASURED THE GROUND FROZEN TO A DEPTH OF 14 INCHES HERE AT THE
OFFICE ON SUNDAY. SOME LOCALIZED POOR DRAINAGE...URBAN AND SMALL
STREAM FLOODING MAY BE POSSIBLE LATER MONDAY DUE TO ENHANCED RUNOFF
FROM RAIN AND MELT ON FROZEN GROUND.
SOME SIGNIFICANT RISES ON MAIN STEM RIVERS ARE POSSIBLE MONDAY INTO
TUESDAY...BUT LARGER RIVER FLOODING IS NOT EXPECTED AT THIS TIME.
RISES WOULD BE ENOUGH TO BREAK UP WHAT RIVER ICE IS IN PLACE BUT ICE
IS NOT THICK ENOUGH TO CAUSE SIGNIFICANT ICE JAM PROBLEMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR CTZ001-013.
NY...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ039-040-
047>054-058>061-063>066.
FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
NYZ032-033-038-041>043-082>084.
MA...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR MAZ001-025.
VT...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...SND/BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
619 AM EST MON JAN 23 2012
.SYNOPSIS...
MOISTURE WILL CONTINUE TO INCREASE AND PROVIDE THE
REGION WITH SOME LIGHT ICING CONDITIONS THIS MORNING. TEMPERATURES
WILL CLIMB ABOVE FREEZING THIS AFTERNOON FOR MAINLY RAIN SHOWERS
THAT WILL ACCOMPANY THE FRONTAL BOUNDARY. SOMEWHAT COOLER AIR WILL
FILTER IN FOR TUESDAY WITH SOME LAKE EFFECT SNOW DOWNWIND OF LAKE
ONTARIO. TRANQUIL CONDITIONS FOR THE MID WEEK AS A RIDGE OF HIGH
PRESSURE TRACKS ACROSS THE AREA.
&&
.NEAR TERM /UNTIL NOON TODAY/...
AS OF 6 AM...DRIZZLE IS BEGINNING TO SHOW UP ACROSS THE TRI-STATE
REGION AND MID-HUDSON VALLEY INCLUDING OUR RADAR IN VCP31.
TEMPERATURES VARY BUT THEY DO HOVER AROUND THE FREEZING MARK WHERE
DRIZZLE IS BEING REPORTED. NCEP MODEL SUITE ALONG WITH THE
RUC13/HRRR NOT DOING THAT WELL...HOWEVER...THEY DO SUGGEST THIS
AREA OF DRIZZLE AND SATURATING BOUNDARY LAYER ADVANCES SLOWLY
NORTH THIS MORNING. WET BULB PROFILES ARE STILL BELOW FREEZING SO
WE WILL CONTINUE WITH THE ADVISORY AND REFRESH THE GRIDS AND
HOURLY TEMPS/DEWPTS. PER THE 06Z MOS AND HOURLY LAV/LAMP...MOST
AREAS WILL CLIMB ABOVE FREEZING AROUND THE NOON HOUR.
PREV DISC...
VERY CHALLENGING NEAR TERM FORECAST AS FZDZ HAS NOT
MATERIALIZED AT THIS TIME. PER METARS...THE CIGS REMAIN RATHER
HIGH AND DEWPOINT DEPRESSIONS ARE 5 DEGREES OR GREATER. WE DID
RECEIVE A REPORT OF FLURRIES IN LITCHFIELD COUNTY AND THIS CAN
ALSO BE CONFIRMED WITH SEVERAL METARS ACROSS THE NYC METRO AREA
REPORTING LIGHT SNOW. THIS MAY BE DUE TO THE OCEANIC EFFECT ADDING
ENOUGH NUCLEI TO RESULT IN THOSE OBS OF LIGHT SNOW. THE FORECAST
SOUNDINGS ACROSS OUR REGION STILL SUGGEST THE BOUNDARY LAYER WILL
MOISTEN UP BELOW THE -10C ISOTHERM INCLUDING THE SHEAR PROFILES
FOR SOME DRIZZLE FORMATION. RUC13 FORECAST SOUNDINGS DELAY THE
ONSET OF MOISTURE UNTIL THE 12-15Z TIME FRAME. BY THAT
TIME...TEMPERATURES ARE BEGINNING TO CLIMB TO AT OR ABOVE FREEZING
ALONG AND SOUTH OF I90. THE COLDER AIR IS EXPECTED TO REMAIN IN
PLACE LONGER ACROSS THE DACKS...LAKE GEORGE SARATOGA REGION AND
SOUTHERN VERMONT UNTIL ABOUT THE NOON HOUR. THE ADVISORY LOOKS
GOOD AT THIS TIME WITH NO CHANGES EXPECTED.
&&
.SHORT TERM /NOON TODAY THROUGH WEDNESDAY/...
POTENT SHORT WAVE TRACKING NORTHWARD ALONG THE MISSISSIPPI RIVER
VALLEY INTO THE GREAT LAKES REGION WILL SEND A COLD FRONT EASTWARD
THIS AFTERNOON. A BAND OF BKN SHOWERS IS EXPECTED AND WE WILL
PLACE CATEGORICAL POPS FOR THE ENTIRE REGION. TIMING OF THIS FRONT
APPEARS TO BE AOA 21Z. AS FOR CONVECTIVE POTENTIAL /IE
THUNDER/...THE SHOWALTER INDEX IS EXPECTED TO DROP TOWARD 0C FOR
PORTIONS OF THE REGION WITH THE BEST UPPER SUPPORT FOR THE WESTERN
MOHAWK VALLEY AND DACKS. WHILE WE WILL NOT INCLUDE THUNDER...WOULD
NOT TOTALLY RULE OUT A RUMBLE OF THUNDER.
WITH FROPA...DRY SLOT QUICKLY APPROACHES THIS EARLY EVENING. SOME
LINGERING UPSLOPE SHOWERS ARE EXPECTED BUT THIS TOO SHOULD
DECREASE THROUGH TONIGHT. SEEMS THE INITIAL COLD ADVECTION WILL
REMAIN WEST OF THE HUDSON RIVER VALLEY WITH TEMPERATURES OVERNIGHT
REMAINING ABOVE FREEZING FOR A GOOD PORTION OF THE REGION. THE
EXCEPTION TO THIS WILL BE FOR PORTIONS OF THE DACKS. LAKE ONTARIO
CONTRIBUTION INCREASES A BIT...ALBEIT MARGINALLY...TO WARRANT
CHANCE POPS FOR RAIN/SNOW SHOWERS TRANSITIONING TO SNOW SHOWER
OVERNIGHT.
DUE TO A RELATIVELY MILDER START TO THE DAY TUESDAY...TEMPERATURES
FOR THE REGION SHOULD ONCE AGAIN CLIMB ABOVE THE FREEZING WITH MID
40S EXPECTED FOR THE MID HUDSON RIVER VALLEY AND NW CT. CYCLONIC
FLOW REMAINS OVER LAKE ONTARIO AND THE DACKS WITH A VEERING WIND
PROFILE TO TAKE WHAT BANDS OF LAKE EFFECT ACTIVITY FURTHER SOUTH.
SECONDARY COLD FRONT IS EXPECTED TO CLEAR THE REGION LATE TUESDAY
AFTERNOON WITH 850MB TEMPS EXPECTED TO PLUNGE BACK BELOW -10C FOR
THE ENTIRE CWA. THERE WILL BE A WINDOW OF OPPORTUNITY FOR A BRIEF
ORGANIZED LAKE EFFECT WITH CLIMBING INVERSION HEIGHTS TUESDAY
EVENING BEFORE FALLING ONCE AGAIN OVERNIGHT. AT THIS POINT...SEEMS
ACCUMULATIONS WILL BE LIMITED AND ISOLATED WITH GENERALLY AROUND 1
INCH. AS UPPER TROUGH SLIDES EAST OF THE REGION...INVERSION
HEIGHTS DROP QUICKLY AS DOES THE DRY AIR ADVECTION ACROSS NY
STATE.
A NARROW SURFACE RIDGE IS EXPECTED ACROSS THE REGION DESPITE
ANOTHER SHORT WAVE MOVING ACROSS THE NORTHERN TIER OF NY AND NEW
ENGLAND. WITH LIMITED MOISTURE...WE WILL KEEP SKIES PTCLOUDY AND
NO MENTION OF PRECIP. NEAR SEASONABLE TEMPERATURES ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD WILL START OUT WITH A RIDGE MOVING ACROSS THE REGION AT
THE SURFACE WITH THE FLOW ALOFT FLATTENING. THE MODELS ARE IN FAIRLY
GOOD AGREEMENT WITH THE LONGWAVE PATTERN...HOWEVER THERE ARE
DIFFERENCES IN THE TIMING AND TRACK OF THE SOUTHERN STREAM SYSTEM
WHICH ORIGINATES OVER THE SOUTHERN PLAINS AND HEADS OUR WAY LATE IN
THE WEEK. THERE IS A QUESTION OF HOW MUCH INTERACTION THERE WILL BE
WITH THE NORTHERN STREAM. AT THIS TIME...THIS SYSTEM IS EXPECTED TO
PASS TO SOUTH BRINGING THE CHANCES FOR PRECIPITATION TO THE AREA
THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL CONTINUE TO RUN ABOVE
NORMAL WITH THE LONGWAVE PATTERN KEEPING THE COLDER AIR TO OUR NORTH
THROUGH THE WORK WEEK. INDICATIONS ARE NORTHERN STREAM ENERGY WILL
DIVE INTO THE NORTHERN PLAINS CAUSING A TROUGH TO DIG OVER THE
EASTERN UNITED STATES OVER THE WEEKEND RETURNING MORE SEASONABLE AIR
TO THE REGION.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL LOWER TO MVFR EARLY THIS MORNING AS THE LOW
LEVELS OF THE ATMOSPHERE MOISTEN UP AHEAD OF AN APPROACHING LOW
PRESSURE SYSTEM. THE CHANCES FOR FREEZING DRIZZLE WILL THEN
INCREASE. TEMPERATURES ARE EXPECTED TO RISE TO ABOVE THE FREEZING
MARK BEFORE THE STEADIER AND HEAVIER PRECIPITATION MOVES IN THIS
AFTERNOON WITH CONDITIONS LOWERING TO IFR. THE STEADY PRECIPITATION
WILL MOVE OFF TO THE EAST DURING THE EVENING HOWEVER IFR CONDITIONS
ARE EXPECTED TO LINGER.
OUTLOOK...
MON NIGHT...MVFR/IFR...IMPROVING TO MVFR/VFR. RAIN TAPERING OFF TO
SCATTERED SHOWERS.
TUE-WED...VFR. NO SIG WX.
THU...MAINLY VFR. CHC -RA/-SN BY LATE IN THE AFTERNOON.
THU NIGHT-FRI..VFR/MVFR. CHC -SHSN/-SHRA.
&&
.HYDROLOGY...
A STORM SYSTEM WILL BRING MIXED PRECIPITATION CHANGING TO RAIN
TODAY. A QUICK SHOT OF MODERATE TO HEAVY RAIN IS POSSIBLE THIS
AFTERNOON WITH A COLD FRONT AS QPF VALUES ARE EXPECTED TO BE BETWEEN
ONE QUARTER TO ONE HALF INCH WITH LOCALIZED AMOUNTS AROUND AN INCH
POSSIBLE INTO THE HIGHER TERRAIN OF THE CATSKILLS...SOUTHERN VERMONT
AND BERKSHIRES.
WE MEASURED THE GROUND FROZEN TO A DEPTH OF 14 INCHES HERE AT THE
OFFICE ON SUNDAY. SOME LOCALIZED POOR DRAINAGE...URBAN AND SMALL
STREAM FLOODING MAY BE POSSIBLE LATER MONDAY DUE TO ENHANCED RUNOFF
FROM RAIN AND MELT ON FROZEN GROUND.
SOME SIGNIFICANT RISES ON MAIN STEM RIVERS ARE POSSIBLE MONDAY INTO
TUESDAY...BUT LARGER RIVER FLOODING IS NOT EXPECTED AT THIS TIME.
RISES WOULD BE ENOUGH TO BREAK UP WHAT RIVER ICE IS IN PLACE BUT ICE
IS NOT THICK ENOUGH TO CAUSE SIGNIFICANT ICE JAM PROBLEMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR CTZ001-013.
NY...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ039-040-
047>054-058>061-063>066.
FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
NYZ032-033-038-041>043-082>084.
MA...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR MAZ001-025.
VT...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...SND/BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
454 AM EST MON JAN 23 2012
.SYNOPSIS...
MOISTURE WILL CONTINUE TO INCREASE AND PROVIDE THE
REGION WITH SOME LIGHT ICING CONDITIONS THIS MORNING. TEMPERATURES
WILL CLIMB ABOVE FREEZING THIS AFTERNOON FOR MAINLY RAIN SHOWERS
THAT WILL ACCOMPANY THE FRONTAL BOUNDARY. SOMEWHAT COOLER AIR WILL
FILTER IN FOR TUESDAY WITH SOME LAKE EFFECT SNOW DOWNWIND OF LAKE
ONTARIO. TRANQUIL CONDITIONS FOR THE MID WEEK AS A RIDGE OF HIGH
PRESSURE TRACKS ACROSS THE AREA.
&&
.NEAR TERM /UNTIL NOON TODAY/...
VERY CHALLENGING NEAR TERM FORECAST AS FZDZ HAS NOT MATERIALIZED
AT THIS TIME. PER METARS...THE CIGS REMAIN RATHER HIGH AND
DEWPOINT DEPRESSIONS ARE 5 DEGREES OR GREATER. WE DID RECEIVE A
REPORT OF FLURRIES IN LITCHFIELD COUNTY AND THIS CAN ALSO BE
CONFIRMED WITH SEVERAL METARS ACROSS THE NYC METRO AREA REPORTING
LIGHT SNOW. THIS MAY BE DUE TO THE OCEANIC EFFECT ADDING ENOUGH
NUCLEI TO RESULT IN THOSE OBS OF LIGHT SNOW. THE FORECAST
SOUNDINGS ACROSS OUR REGION STILL SUGGEST THE BOUNDARY LAYER WILL
MOISTEN UP BELOW THE -10C ISOTHERM INCLUDING THE SHEAR PROFILES
FOR SOME DRIZZLE FORMATION. RUC13 FORECAST SOUNDINGS DELAY THE
ONSET OF MOISTURE UNTIL THE 12-15Z TIME FRAME. BY THAT
TIME...TEMPERATURES ARE BEGINNING TO CLIMB TO AT OR ABOVE
FREEZING ALONG AND SOUTH OF I90. THE COLDER AIR IS EXPECTED TO
REMAIN IN PLACE LONGER ACROSS THE DACKS...LAKE GEORGE SARATOGA
REGION AND SOUTHERN VERMONT UNTIL ABOUT THE NOON HOUR. THE
ADVISORY LOOKS GOOD AT THIS TIME WITH NO CHANGES EXPECTED.
&&
.SHORT TERM /NOON TODAY THROUGH WEDNESDAY/...
POTENT SHORT WAVE TRACKING NORTHWARD ALONG THE MISSISSIPPI RIVER
VALLEY INTO THE GREAT LAKES REGION WILL SEND A COLD FRONT EASTWARD
THIS AFTERNOON. A BAND OF BKN SHOWERS IS EXPECTED AND WE WILL
PLACE CATEGORICAL POPS FOR THE ENTIRE REGION. TIMING OF THIS FRONT
APPEARS TO BE AOA 21Z. AS FOR CONVECTIVE POTENTIAL /IE
THUNDER/...THE SHOWALTER INDEX IS EXPECTED TO DROP TOWARD 0C FOR
PORTIONS OF THE REGION WITH THE BEST UPPER SUPPORT FOR THE WESTERN
MOHAWK VALLEY AND DACKS. WHILE WE WILL NOT INCLUDE THUNDER...WOULD
NOT TOTALLY RULE OUT A RUMBLE OF THUNDER.
WITH FROPA...DRY SLOT QUICKLY APPROACHES THIS EARLY EVENING. SOME
LINGERING UPSLOPE SHOWERS ARE EXPECTED BUT THIS TOO SHOULD
DECREASE THROUGH TONIGHT. SEEMS THE INITIAL COLD ADVECTION WILL
REMAIN WEST OF THE HUDSON RIVER VALLEY WITH TEMPERATURES OVERNIGHT
REMAINING ABOVE FREEZING FOR A GOOD PORTION OF THE REGION. THE
EXCEPTION TO THIS WILL BE FOR PORTIONS OF THE DACKS. LAKE ONTARIO
CONTRIBUTION INCREASES A BIT...ALBEIT MARGINALLY...TO WARRANT
CHANCE POPS FOR RAIN/SNOW SHOWERS TRANSITIONING TO SNOW SHOWER
OVERNIGHT.
DUE TO A RELATIVELY MILDER START TO THE DAY TUESDAY...TEMPERATURES
FOR THE REGION SHOULD ONCE AGAIN CLIMB ABOVE THE FREEZING WITH MID
40S EXPECTED FOR THE MID HUDSON RIVER VALLEY AND NW CT. CYCLONIC
FLOW REMAINS OVER LAKE ONTARIO AND THE DACKS WITH A VEERING WIND
PROFILE TO TAKE WHAT BANDS OF LAKE EFFECT ACTIVITY FURTHER SOUTH.
SECONDARY COLD FRONT IS EXPECTED TO CLEAR THE REGION LATE TUESDAY
AFTERNOON WITH 850MB TEMPS EXPECTED TO PLUNGE BACK BELOW -10C FOR
THE ENTIRE CWA. THERE WILL BE A WINDOW OF OPPORTUNITY FOR A BRIEF
ORGANIZED LAKE EFFECT WITH CLIMBING INVERSION HEIGHTS TUESDAY
EVENING BEFORE FALLING ONCE AGAIN OVERNIGHT. AT THIS POINT...SEEMS
ACCUMULATIONS WILL BE LIMITED AND ISOLATED WITH GENERALLY AROUND 1
INCH. AS UPPER TROUGH SLIDES EAST OF THE REGION...INVERSION
HEIGHTS DROP QUICKLY AS DOES THE DRY AIR ADVECTION ACROSS NY
STATE.
A NARROW SURFACE RIDGE IS EXPECTED ACROSS THE REGION DESPITE
ANOTHER SHORT WAVE MOVING ACROSS THE NORTHERN TIER OF NY AND NEW
ENGLAND. WITH LIMITED MOISTURE...WE WILL KEEP SKIES PTCLOUDY AND
NO MENTION OF PRECIP. NEAR SEASONABLE TEMPERATURES ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE PERIOD WILL START OUT WITH A RIDGE MOVING ACROSS THE REGION AT
THE SURFACE WITH THE FLOW ALOFT FLATTENING. THE MODELS ARE IN FAIRLY
GOOD AGREEMENT WITH THE LONGWAVE PATTERN...HOWEVER THERE ARE
DIFFERENCES IN THE TIMING AND TRACK OF THE SOUTHERN STREAM SYSTEM
WHICH ORIGINATES OVER THE SOUTHERN PLAINS AND HEADS OUR WAY LATE IN
THE WEEK. THERE IS A QUESTION OF HOW MUCH INTERACTION THERE WILL BE
WITH THE NORTHERN STREAM. AT THIS TIME...THIS SYSTEM IS EXPECTED TO
PASS TO SOUTH BRINGING THE CHANCES FOR PRECIPITATION TO THE AREA
THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL CONTINUE TO RUN ABOVE
NORMAL WITH THE LONGWAVE PATTERN KEEPING THE COLDER AIR TO OUR NORTH
THROUGH THE WORK WEEK. INDICATIONS ARE NORTHERN STREAM ENERGY WILL
DIVE INTO THE NORTHERN PLAINS CAUSING A TROUGH TO DIG OVER THE
EASTERN UNITED STATES OVER THE WEEKEND RETURNING MORE SEASONABLE AIR
TO THE REGION.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL LOWER TO MVFR EARLY THIS MORNING AS THE LOW
LEVELS OF THE ATMOSPHERE MOISTEN UP AHEAD OF AN APPROACHING LOW
PRESSURE SYSTEM. THE CHANCES FOR FREEZING DRIZZLE WILL THEN
INCREASE. TEMPERATURES ARE EXPECTED TO RISE TO ABOVE THE FREEZING
MARK BEFORE THE STEADIER AND HEAVIER PRECIPITATION MOVES IN THIS
AFTERNOON WITH CONDITIONS LOWERING TO IFR. THE STEADY PRECIPITATION
WILL MOVE OFF TO THE EAST DURING THE EVENING HOWEVER IFR CONDITIONS
ARE EXPECTED TO LINGER.
OUTLOOK...
MON NIGHT...MVFR/IFR...IMPROVING TO MVFR/VFR. RAIN TAPERING OFF TO
SCATTERED SHOWERS.
TUE-WED...VFR. NO SIG WX.
THU...MAINLY VFR. CHC -RA/-SN BY LATE IN THE AFTERNOON.
THU NIGHT-FRI..VFR/MVFR. CHC -SHSN/-SHRA.
&&
.HYDROLOGY...
A STORM SYSTEM WILL BRING MIXED PRECIPITATION CHANGING TO RAIN
TODAY. A QUICK SHOT OF MODERATE TO HEAVY RAIN IS POSSIBLE THIS
AFTERNOON WITH A COLD FRONT AS QPF VALUES ARE EXPECTED TO BE BETWEEN
ONE QUARTER TO ONE HALF INCH WITH LOCALIZED AMOUNTS AROUND AN INCH
POSSIBLE INTO THE HIGHER TERRAIN OF THE CATSKILLS...SOUTHERN VERMONT
AND BERKSHIRES.
WE MEASURED THE GROUND FROZEN TO A DEPTH OF 14 INCHES HERE AT THE
OFFICE ON SUNDAY. SOME LOCALIZED POOR DRAINAGE...URBAN AND SMALL
STREAM FLOODING MAY BE POSSIBLE LATER MONDAY DUE TO ENHANCED RUNOFF
FROM RAIN AND MELT ON FROZEN GROUND.
SOME SIGNIFICANT RISES ON MAIN STEM RIVERS ARE POSSIBLE MONDAY INTO
TUESDAY...BUT LARGER RIVER FLOODING IS NOT EXPECTED AT THIS TIME.
RISES WOULD BE ENOUGH TO BREAK UP WHAT RIVER ICE IS IN PLACE BUT ICE
IS NOT THICK ENOUGH TO CAUSE SIGNIFICANT ICE JAM PROBLEMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR CTZ001-013.
NY...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ039-040-
047>054-058>061-063>066.
FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
NYZ032-033-038-041>043-082>084.
MA...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR MAZ001-025.
VT...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...SND/BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
426 AM EST MON JAN 23 2012
.SYNOPSIS...
MOISTURE WILL CONTINUE TO INCREASE AND PROVIDE THE
REGION WITH SOME LIGHT ICING CONDITIONS THIS MORNING. TEMPERATURES
WILL CLIMB ABOVE FREEZING THIS AFTERNOON FOR MAINLY RAIN SHOWERS
THAT WILL ACCOMPANY THE FRONTAL BOUNDARY. SOMEWHAT COOLER AIR WILL
FILTER IN FOR TUESDAY WITH SOME LAKE EFFECT SNOW DOWNWIND OF LAKE
ONTARIO. TRANQUIL CONDITIONS FOR THE MID WEEK AS A RIDGE OF HIGH
PRESSURE TRACKS ACROSS THE AREA.
&&
.NEAR TERM /UNTIL NOON TODAY/...
VERY CHALLENGING NEAR TERM FORECAST AS FZDZ HAS NOT MATERIALIZED
AT THIS TIME. PER METARS...THE CIGS REMAIN RATHER HIGH AND
DEWPOINT DEPRESSIONS ARE 5 DEGREES OR GREATER. WE DID RECEIVE A
REPORT OF FLURRIES IN LITCHFIELD COUNTY AND THIS CAN ALSO BE
CONFIRMED WITH SEVERAL METARS ACROSS THE NYC METRO AREA REPORTING
LIGHT SNOW. THIS MAY BE DUE TO THE OCEANIC EFFECT ADDING ENOUGH
NUCLEI TO RESULT IN THOSE OBS OF LIGHT SNOW. THE FORECAST
SOUNDINGS ACROSS OUR REGION STILL SUGGEST THE BOUNDARY LAYER WILL
MOISTEN UP BELOW THE -10C ISOTHERM INCLUDING THE SHEAR PROFILES
FOR SOME DRIZZLE FORMATION. RUC13 FORECAST SOUNDINGS DELAY THE
ONSET OF MOISTURE UNTIL THE 12-15Z TIME FRAME. BY THAT
TIME...TEMPERATURES ARE BEGINNING TO CLIMB TO AT OR ABOVE
FREEZING ALONG AND SOUTH OF I90. THE COLDER AIR IS EXPECTED TO
REMAIN IN PLACE LONGER ACROSS THE DACKS...LAKE GEORGE SARATOGA
REGION AND SOUTHERN VERMONT UNTIL ABOUT THE NOON HOUR. THE
ADVISORY LOOKS GOOD AT THIS TIME WITH NO CHANGES EXPECTED.
&&
.SHORT TERM /NOON TODAY THROUGH WEDNESDAY/...
POTENT SHORT WAVE TRACKING NORTHWARD ALONG THE MISSISSIPPI RIVER
VALLEY INTO THE GREAT LAKES REGION WILL SEND A COLD FRONT EASTWARD
THIS AFTERNOON. A BAND OF BKN SHOWERS IS EXPECTED AND WE WILL
PLACE CATEGORICAL POPS FOR THE ENTIRE REGION. TIMING OF THIS FRONT
APPEARS TO BE AOA 21Z. AS FOR CONVECTIVE POTENTIAL /IE
THUNDER/...THE SHOWALTER INDEX IS EXPECTED TO DROP TOWARD 0C FOR
PORTIONS OF THE REGION WITH THE BEST UPPER SUPPORT FOR THE WESTERN
MOHAWK VALLEY AND DACKS. WHILE WE WILL NOT INCLUDE THUNDER...WOULD
NOT TOTALLY RULE OUT A RUMBLE OF THUNDER.
WITH FROPA...DRY SLOT QUICKLY APPROACHES THIS EARLY EVENING. SOME
LINGERING UPSLOPE SHOWERS ARE EXPECTED BUT THIS TOO SHOULD
DECREASE THROUGH TONIGHT. SEEMS THE INITIAL COLD ADVECTION WILL
REMAIN WEST OF THE HUDSON RIVER VALLEY WITH TEMPERATURES OVERNIGHT
REMAINING ABOVE FREEZING FOR A GOOD PORTION OF THE REGION. THE
EXCEPTION TO THIS WILL BE FOR PORTIONS OF THE DACKS. LAKE ONTARIO
CONTRIBUTION INCREASES A BIT...ALBEIT MARGINALLY...TO WARRANT
CHANCE POPS FOR RAIN/SNOW SHOWERS TRANSITIONING TO SNOW SHOWER
OVERNIGHT.
DUE TO A RELATIVELY MILDER START TO THE DAY TUESDAY...TEMPERATURES
FOR THE REGION SHOULD ONCE AGAIN CLIMB ABOVE THE FREEZING WITH MID
40S EXPECTED FOR THE MID HUDSON RIVER VALLEY AND NW CT. CYCLONIC
FLOW REMAINS OVER LAKE ONTARIO AND THE DACKS WITH A VEERING WIND
PROFILE TO TAKE WHAT BANDS OF LAKE EFFECT ACTIVITY FURTHER SOUTH.
SECONDARY COLD FRONT IS EXPECTED TO CLEAR THE REGION LATE TUESDAY
AFTERNOON WITH 850MB TEMPS EXPECTED TO PLUNGE BACK BELOW -10C FOR
THE ENTIRE CWA. THERE WILL BE A WINDOW OF OPPORTUNITY FOR A BRIEF
ORGANIZED LAKE EFFECT WITH CLIMBING INVERSION HEIGHTS TUESDAY
EVENING BEFORE FALLING ONCE AGAIN OVERNIGHT. AT THIS POINT...SEEMS
ACCUMULATIONS WILL BE LIMITED AND ISOLATED WITH GENERALLY AROUND 1
INCH. AS UPPER TROUGH SLIDES EAST OF THE REGION...INVERSION
HEIGHTS DROP QUICKLY AS DOES THE DRY AIR ADVECTION ACROSS NY
STATE.
A NARROW SURFACE RIDGE IS EXPECTED ACROSS THE REGION DESPITE
ANOTHER SHORT WAVE MOVING ACROSS THE NORTHERN TIER OF NY AND NEW
ENGLAND. WITH LIMITED MOISTURE...WE WILL KEEP SKIES PTCLOUDY AND
NO MENTION OF PRECIP. NEAR SEASONABLE TEMPERATURES ARE EXPECTED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FORTHCOMING...
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL LOWER TO MVFR EARLY THIS MORNING AS THE LOW
LEVELS OF THE ATMOSPHERE MOISTEN UP AHEAD OF AN APPROACHING LOW
PRESSURE SYSTEM. THE CHANCES FOR FREEZING DRIZZLE WILL THEN
INCREASE. TEMPERATURES ARE EXPECTED TO RISE TO ABOVE THE FREEZING
MARK BEFORE THE STEADIER AND HEAVIER PRECIPITATION MOVES IN THIS
AFTERNOON WITH CONDITIONS LOWERING TO IFR. THE STEADY PRECIPITATION
WILL MOVE OFF TO THE EAST DURING THE EVENING HOWEVER IFR CONDITIONS
ARE EXPECTED TO LINGER.
OUTLOOK...
MON NIGHT...MVFR/IFR...RA LIKELY EARLY...THEN VFR/MVFR WITH SCT
-SHRA/-SHSN LATE.
TUE-WED...VFR...NO SIG WX.
THU-FRI. VFR. SLIGHT CHC -SHSN/-SHRA.
&&
.HYDROLOGY...
A STORM SYSTEM WILL BRING MIXED PRECIPITATION CHANGING TO RAIN
TODAY. A QUICK SHOT OF MODERATE TO HEAVY RAIN IS POSSIBLE THIS AFTERNOON
WITH A COLD FRONT AS QPF VALUES ARE EXPECTED TO BE BETWEEN ONE
QUARTER TO ONE HALF INCH WITH LOCALIZED AMOUNTS AROUND AN INCH
POSSIBLE INTO THE HIGHER TERRAIN OF THE CATSKILLS...SOUTHERN
VERMONT AND BERKSHIRES.
WE MEASURED THE GROUND FROZEN TO A DEPTH OF 14 INCHES HERE AT THE
OFFICE ON SUNDAY. SOME LOCALIZED POOR DRAINAGE...URBAN AND SMALL
STREAM FLOODING MAY BE POSSIBLE LATER MONDAY DUE TO ENHANCED RUNOFF
FROM RAIN AND MELT ON FROZEN GROUND.
SOME SIGNIFICANT RISES ON MAIN STEM RIVERS ARE POSSIBLE MONDAY INTO
TUESDAY...BUT LARGER RIVER FLOODING IS NOT EXPECTED AT THIS TIME.
RISES WOULD BE ENOUGH TO BREAK UP WHAT RIVER ICE IS IN PLACE BUT ICE
IS NOT THICK ENOUGH TO CAUSE SIGNIFICANT ICE JAM PROBLEMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR CTZ001-013.
NY...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ039-040-
047>054-058>061-063>066.
FREEZING RAIN ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
NYZ032-033-038-041>043-082>084.
MA...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR MAZ001-025.
VT...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...SND/BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1104 AM EST MON JAN 23 2012
.SYNOPSIS...
THE SURFACE WEDGE WILL REMAIN ACROSS THE REGION THIS AFTERNOON. A
WEAK FRONT WILL SLOWLY MOVE ACROSS THE REGION TONIGHT AND TUESDAY
MORNING. FAIR WEATHER EXPECTED TUESDAY INTO WEDNESDAY...THEN
RETURNING MOISTURE AND THE APPROACH OF ANOTHER WEATHER SYSTEM WILL
PROVIDE A CHANCE OF PRECIPITATION LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DENSE FOG DEVELOPING ACROSS THE CENTRAL AND SOUTH MIDLANDS/CSRA.
WILL ISSUE DENSE FOG ADVISORY UNTIL 300 PM.
LATEST RUC MODEL SUGGEST WEDGE WILL NOT BREAK DOWN THIS
AFTERNOON...MODELS USUALLY BREAK WEDGE TOO QUICKLY...SO WILL LOWER
MAXIMUM TEMPERATURES ABOUT 10 DEGREES.
AS ISENTROPIC LIFT CONTINUES WITH STRONG LOW LEVEL SOUTH FLOW...RAIN
SPREADING IN FROM NORTH CENTRAL GEORGIA...MAINLY ADVECTING INTO
WESTERN MIDLANDS AND CSRA. INCREASED POPS IN THOSE AREAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE COLD FRONT WILL BE SLOW TO PASS THROUGH THE REGION TONIGHT.
HOWEVER IT APPEARS MOISTURE WILL BE LIMITED...AND MUCH OF THE
UPPER ENERGY WILL HAVE PASSED NORTH OF THE REGION. HAVE ELECTED TO
GO WITH A DRY FORECAST TONIGHT. DID PUT MENTION OF FOG IN FOR NOW.
THE FRONT WILL STALL OUT SOUTH OF THE FORECAST AREA TUESDAY AND
TUESDAY NIGHT. DRY WEATHER EXPECTED THROUGH THAT PERIOD. EVEN
THOUGH THE FRONT WILL BE SOUTH...MORE SUNSHINE ON TUESDAY WILL
ALLOW TEMPERATURES TO CLIMB INTO THE 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
LITTLE TO NO CHANGES WERE MADE IN THE LONG TERM. PREVIOUS
DISCUSSION FOLLOWS. GFS/ECMWF CLOSE OFF UPPER LOW AND MOVE IT
SLOWLY EAST ACROSS TEXAS WED/THU. MEANWHILE SURFACE HIGH CENTER
RIDES BY TO OUR NORTH...AND WEAK FRONT LIFTS SLOWLY BACK NORTH
ACROSS OUR REGION. THIS COULD PROVIDE SLIGHT CHANCE POPS...WITH
WEAK ISENTROPIC LIFT BY THURSDAY. BOTH GFS/ECMWF OPEN THE UPPER
LOW AND SHIFT IT EAST ACROSS OUR REGION...BUT DIFFERENCE IN
SOLUTIONS REGARDS TIMING. ECMWF RUN OPENS IT UP EARLIER THAN GFS.
WILL INDICATE HIGH END CHANCE POPS THU NT THRU FRI NT. HIGH
PRESSURE TO BUILD IN BEHIND FRONT LATE IN THE FORECAST PERIOD.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
COLD AIR DAMMING PERSISTS ACROSS THE REGION WITH IFR CIGS/VSBYS
EARLY THIS MORNING UNTIL AROUND 14Z-15Z THIS MORNING AS MOISTURE
FLUX AND INCREASE ISENTROPIC LIFT OVER REGION PRODUCING EITHER
DRIZZLE OR PATCHY LIGHT RAIN ALONG WITH AREAS OF FOG.
WARM FRONT IS EXPECTED TO APPROACH AND BUT REMAIN SOUTH OF THE
AREA THROUGH MOST OF THE AFTERNOON. 17Z- 18Z SCATTERED SHOWERS.
CIGS IFR AND MAY BE MVFR BY LATER THIS AFTERNOON CONTINUING INTO
THE EVENING HOURS. ALSO...WITH INCREASING LOW LEVEL WINDS
SOUTHWEST AROUND 30 KNOTS AT 1-2 KFT WITH WARM FRONT LATER THIS
AFTERNOON MAY LEAD TO LOW LEVEL WIND SHEAR MONDAY AFTERNOON AS THE
WEDGE BEGINS TO BREAK DOWN. ISOLD STORMS MAY BE POSSIBLE DURING
THE AFTERNOON AS WELL BUT WILL JUST USE VCSH IN THE TAFS FOR NOW
GIVEN CURRENT UNCERTAINTIES. CIGS RISE TO AROUND 4 KFT BY AROUND
01Z TUESDAY AS WARM AIR ADVECTION AHEAD OF THE COLD FRONT
INCREASES. AFTER FROPA THIS EVENING...WITH SW FLOW ALOFT...MVFR-
IFR CIGS/VSBYS POSSIBLE UNTIL THE END OF THE TAF PERIOD.
EXTENDED AVIATION OUTLOOK...CEILINGS/VISIBILITIES BECOMING VFR
TUESDAY MORNING. WIDESPREAD IFR CONDITION MAY OCCUR WEDNESDAY NIGHT
THROUGH THURSDAY ASSOCIATED WITH ANOTHER FRONTAL SYSTEM.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR SCZ018-
020-025>028-030-031-035>038-041.
GA...DENSE FOG ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR GAZ040-
063>065-077.
&&
$$
SYNOPSIS...77
NEAR TERM...77
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
928 AM EST MON JAN 23 2012
.SYNOPSIS...
THE SURFACE WEDGE WILL SLOWLY SHIFT NORTH/NORTHWEST DURING TODAY.
A WEAK FRONT WILL SLOWLY MOVE ACROSS THE REGION TONIGHT AND
TUESDAY MORNING. FAIR WEATHER EXPECTED TUESDAY INTO WEDNESDAY...THEN
RETURNING MOISTURE AND THE APPROACH OF ANOTHER WEATHER SYSTEM WILL
PROVIDE A CHANCE OF PRECIPITATION LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DENSE FOG DEVELOPING ACROSS THE CENTRAL AND SOUTH MIDLANDS/CSRA.
WILL ISSUE DENSE FOG ADVISORY UNTIL 300 PM.
LATEST RUC MODEL SUGGEST WEDGE WILL NOT BREAK DOWN THIS
AFTERNOON...MODELS USUALLY BREAK WEDGE TOO QUICKLY...SO WILL LOWER
MAXIMUM TEMPERATURES ABOUT 10 DEGREES.
THE MORNING DRIZZLE WILL GIVE WAY TO A CHANCE OF SHOWERS AS THE
WEDGE BREAKS AHEAD OF AN APPROACHING COLD FRONT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE COLD FRONT WILL BE SLOW TO PASS THROUGH THE REGION TONIGHT.
HOWEVER IT APPEARS MOISTURE WILL BE LIMITED...AND MUCH OF THE
UPPER ENERGY WILL HAVE PASSED NORTH OF THE REGION. HAVE ELECTED TO
GO WITH A DRY FORECAST TONIGHT. DID PUT MENTION OF FOG IN FOR NOW.
THE FRONT WILL STALL OUT SOUTH OF THE FORECAST AREA TUESDAY AND
TUESDAY NIGHT. DRY WEATHER EXPECTED THROUGH THAT PERIOD. EVEN
THOUGH THE FRONT WILL BE SOUTH...MORE SUNSHINE ON TUESDAY WILL
ALLOW TEMPERATURES TO CLIMB INTO THE 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
LITTLE TO NO CHANGES WERE MADE IN THE LONG TERM. PREVIOUS
DISCUSSION FOLLOWS. GFS/ECMWF CLOSE OFF UPPER LOW AND MOVE IT
SLOWLY EAST ACROSS TEXAS WED/THU. MEANWHILE SURFACE HIGH CENTER
RIDES BY TO OUR NORTH...AND WEAK FRONT LIFTS SLOWLY BACK NORTH
ACROSS OUR REGION. THIS COULD PROVIDE SLIGHT CHANCE POPS...WITH
WEAK ISENTROPIC LIFT BY THURSDAY. BOTH GFS/ECMWF OPEN THE UPPER
LOW AND SHIFT IT EAST ACROSS OUR REGION...BUT DIFFERENCE IN
SOLUTIONS REGARDS TIMING. ECMWF RUN OPENS IT UP EARLIER THAN GFS.
WILL INDICATE HIGH END CHANCE POPS THU NT THRU FRI NT. HIGH
PRESSURE TO BUILD IN BEHIND FRONT LATE IN THE FORECAST PERIOD.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
COLD AIR DAMMING PERSISTS ACROSS THE REGION WITH IFR CIGS/VSBYS
EARLY THIS MORNING UNTIL AROUND 14Z-15Z THIS MORNING AS MOISTURE
FLUX AND INCREASE ISENTROPIC LIFT OVER REGION PRODUCING EITHER
DRIZZLE OR PATCHY LIGHT RAIN ALONG WITH AREAS OF FOG.
WARM FRONT IS EXPECTED TO APPROACH AND BUT REMAIN SOUTH OF THE
AREA THROUGH MOST OF THE AFTERNOON. 17Z- 18Z SCATTERED SHOWERS.
CIGS IFR AND MAY BE MVFR BY LATER THIS AFTERNOON CONTINUING INTO
THE EVENING HOURS. ALSO...WITH INCREASING LOW LEVEL WINDS
SOUTHWEST AROUND 30 KNOTS AT 1-2 KFT WITH WARM FRONT LATER THIS
AFTERNOON MAY LEAD TO LOW LEVEL WIND SHEAR MONDAY AFTERNOON AS THE
WEDGE BEGINS TO BREAK DOWN. ISOLD STORMS MAY BE POSSIBLE DURING
THE AFTERNOON AS WELL BUT WILL JUST USE VCSH IN THE TAFS FOR NOW
GIVEN CURRENT UNCERTAINTIES. CIGS RISE TO AROUND 4 KFT BY AROUND
01Z TUESDAY AS WARM AIR ADVECTION AHEAD OF THE COLD FRONT
INCREASES. AFTER FROPA THIS EVENING...WITH SW FLOW ALOFT...MVFR-
IFR CIGS/VSBYS POSSIBLE UNTIL THE END OF THE TAF PERIOD.
EXTENDED AVIATION OUTLOOK...CEILINGS/VISIBILITIES BECOMING VFR
TUESDAY MORNING. WIDESPREAD IFR CONDITION MAY OCCUR WEDNESDAY NIGHT
THROUGH THURSDAY ASSOCIATED WITH ANOTHER FRONTAL SYSTEM.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR SCZ018-
020-025>028-030-031-035>038-041.
GA...DENSE FOG ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR GAZ040-
063>065-077.
&&
$$
SYNOPSIS...77
NEAR TERM...77
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
741 AM EST MON JAN 23 2012
.SYNOPSIS...
THE SURFACE WEDGE WILL SLOWLY SHIFT NORTH/NORTHWEST DURING TODAY.
A WEAK FRONT WILL SLOWLY MOVE ACROSS THE REGION TONIGHT AND
TUESDAY MORNING. FAIR WEATHER EXPECTED TUESDAY INTO WEDNESDAY...THEN
RETURNING MOISTURE AND THE APPROACH OF ANOTHER WEATHER SYSTEM WILL
PROVIDE A CHANCE OF PRECIPITATION LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST RUC MODEL SUGGEST WEDGE WILL NOT BREAK DOWN THIS
AFTERNOON...MODELS USUALLY BREAK WEDGE TOO QUICKLY...SO WILL
LOWER MAXIMUM TEMPERATURES ABOUT 10 DEGREES.
THE MORNING DRIZZLE WILL GIVE WAY TO A CHANCE OF SHOWERS AS THE
WEDGE BREAKS AHEAD OF AN APPROACHING COLD FRONT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE COLD FRONT WILL BE SLOW TO PASS THROUGH THE REGION TONIGHT.
HOWEVER IT APPEARS MOISTURE WILL BE LIMITED...AND MUCH OF THE
UPPER ENERGY WILL HAVE PASSED NORTH OF THE REGION. HAVE ELECTED TO
GO WITH A DRY FORECAST TONIGHT. DID PUT MENTION OF FOG IN FOR NOW.
THE FRONT WILL STALL OUT SOUTH OF THE FORECAST AREA TUESDAY AND
TUESDAY NIGHT. DRY WEATHER EXPECTED THROUGH THAT PERIOD. EVEN
THOUGH THE FRONT WILL BE SOUTH...MORE SUNSHINE ON TUESDAY WILL
ALLOW TEMPERATURES TO CLIMB INTO THE 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
LITTLE TO NO CHANGES WERE MADE IN THE LONG TERM. PREVIOUS
DISCUSSION FOLLOWS. GFS/ECMWF CLOSE OFF UPPER LOW AND MOVE IT
SLOWLY EAST ACROSS TEXAS WED/THU. MEANWHILE SURFACE HIGH CENTER
RIDES BY TO OUR NORTH...AND WEAK FRONT LIFTS SLOWLY BACK NORTH
ACROSS OUR REGION. THIS COULD PROVIDE SLIGHT CHANCE POPS...WITH
WEAK ISENTROPIC LIFT BY THURSDAY. BOTH GFS/ECMWF OPEN THE UPPER
LOW AND SHIFT IT EAST ACROSS OUR REGION...BUT DIFFERENCE IN
SOLUTIONS REGARDS TIMING. ECMWF RUN OPENS IT UP EARLIER THAN GFS.
WILL INDICATE HIGH END CHANCE POPS THU NT THRU FRI NT. HIGH
PRESSURE TO BUILD IN BEHIND FRONT LATE IN THE FORECAST PERIOD.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
COLD AIR DAMMING PERSISTS ACROSS THE REGION WITH IFR CIGS/VSBYS
EARLY THIS MORNING UNTIL AROUND 14Z-15Z THIS MORNING AS MOISTURE
FLUX AND INCREASE ISENTROPIC LIFT OVER REGION PRODUCING EITHER
DRIZZLE OR PATCHY LIGHT RAIN ALONG WITH AREAS OF FOG.
WARM FRONT IS EXPECTED TO APPROACH AND BUT REMAIN SOUTH OF THE
AREA THROUGH MOST OF THE AFTERNOON. 17Z- 18Z SCATTERED SHOWERS.
CIGS IFR AND MAY BE MVFR BY LATER THIS AFTERNOON CONTINUING INTO
THE EVENING HOURS. ALSO...WITH INCREASING LOW LEVEL WINDS
SOUTHWEST AROUND 30 KNOTS AT 1-2 KFT WITH WARM FRONT LATER THIS
AFTERNOON MAY LEAD TO LOW LEVEL WIND SHEAR MONDAY AFTERNOON AS THE
WEDGE BEGINS TO BREAK DOWN. ISOLD STORMS MAY BE POSSIBLE DURING
THE AFTERNOON AS WELL BUT WILL JUST USE VCSH IN THE TAFS FOR NOW
GIVEN CURRENT UNCERTAINTIES. CIGS RISE TO AROUND 4 KFT BY AROUND
01Z TUESDAY AS WARM AIR ADVECTION AHEAD OF THE COLD FRONT
INCREASES. AFTER FROPA THIS EVENING...WITH SW FLOW ALOFT...MVFR-
IFR CIGS/VSBYS POSSIBLE UNTIL THE END OF THE TAF PERIOD.
EXTENDED AVIATION OUTLOOK...CEILINGS/VISIBILITIES BECOMING VFR
TUESDAY MORNING. WIDESPREAD IFR CONDITION MAY OCCUR WEDNESDAY NIGHT
THROUGH THURSDAY ASSOCIATED WITH ANOTHER FRONTAL SYSTEM.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...77
NEAR TERM...77
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
245 AM CST MON JAN 23 2012
.DISCUSSION...
910 PM CST
NOT MUCH CHANGE TO THE GOING FORECAST THIS EVENING. TRENDS ARE
PANNING OUT AS EXPECTED AND ARE IN A MONITOR MODE WITH THE
CONVECTION TO THE SOUTH. ACROSS THE AREA...VAD WIND PROFILE SHOW
WINDS AT 1KFT GENERALLY OUT OF THE SOUTHEAST AT 20 OR SO KT...AND
AT 3KFT...SOUTH TO SOUTHWEST AT 50 TO 55KT. MODEL PROGS SHOW THAT
THE LLJ WILL CONTINUE TO INCREASE AND WILL GIVE ANY STORMS THAT
WORK THROUGH...THE POTENTIAL BE STRONG. MID LEVEL LAPSE RATES HAD
BEEN PROGGED TO RANGE FROM 6-7.5 C/KM THIS EVE...BUT RUC ANALYSIS
SHOWED THAT BEING ON THE WANE AS OF 03Z...WITH THE HIGHEST VALUES
SHIFTING EAST. DESPITE THE SURGE OF WARMTH AND
MOISTURE...CONVECTION WILL HAVE TO STRUGGLE AGAINST A STABLE
SURFACE AIRMASS. THE BEST FOCUS STILL SET TO REMAIN SOUTH FOR
SEVERE ACTIVITY...WITH THE BEST FOCUS LOCALLY...GENERALLY EAST OF
THE I-57 CORRIDOR THROUGH THE MIDNIGHT HOUR WHERE A FEW RUMBLES OF
THUNDER MAY BE HEARD. LATEST GRIDS AND ZONES ARE OUT. SHEA
//PREV DISCUSSION...
357 PM CST
JUST 48 HOURS AFTER A WINTER STORM...THE WEATHER WILL SWING
VIGOROUSLY THE OTHER WAY ACROSS THE MIDDLE OF THE COUNTRY
TONIGHT. MUCH OF THE ATTENTION ON THE FORECAST WAS SPENT ON THE
PRESENT THROUGH MONDAY...WITH CONCERNS ON DENSE FOG...INITIAL
FREEZING DRIZZLE...CONVECTION...GUSTY WINDS...AND SOME SNOW TO
ROUND IT OUT DURING MONDAY.
SYNOPSIS...THE WELL-DEFINED UPPER LOW IS TAKING BETTER SHAPE OVER
THE CENTRAL PLAINS THIS AFTERNOON...WITH SIGNS OF A STRONG MID-
LEVEL JET AND DRY SLOT DEVELOPING INTO THE OZARKS. THE SURFACE LOW
AT 992 MB OVER EASTERN KS HAS BEEN SLIGHTLY DEEPER THAN SOME OF
THE MODELS HAD INDICATED FOR THIS AFTERNOON. THE PRIMARY SURFACE
THETA-E GRADIENT IS DRAPED FROM NORTHERN MO INTO SOUTHERN IL.
LOW-LEVEL FLOW HAS BEEN INCREASING OVER THE FORECAST AREA...WHICH
IN PLACES HAS CAUSED SOME BLOWING AND DRIFTING OF THE LIGHT AND
FLUFFY SNOW SEEN THIS PAST FRIDAY. TEMPERATURES HAVE RESPONDED TO
THE RETURN FLOW AS WELL...CLIMBING INTO THE MID 30S ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA. INCREASING SURFACE
TEMPERATURES AND DEW POINTS WILL CONTINUE INTO TONIGHT...WITH THE
PRIMARY GRADIENT MARCHING MORE QUICKLY NORTH THROUGH IL AND IN
THAN IT HAD TODAY AS CYCLOGENESIS FURTHER OCCURS. THE SURFACE LOW
WILL SHIFT NORTHEAST TO NEAR THE QUAD CITIES BY 3 AM AS THE UPPER
TROUGH BECOMES NEGATIVELY TILED. THE COLD FRONT WILL PUSH QUICKLY
FROM SOUTHWEST TO NORTHEAST ACROSS THE FORECAST AREA BETWEEN 3 AM
AND 7 AM...WITH LIKELY AN AREA OF SHOWERS AND CONVECTION AHEAD OF
IT BETWEEN 10 PM AND 3 AM. THE LOW WILL THEN SHIFT ON TO THE
NORTHERN PART OF LAKE MICHIGAN BY LATE MONDAY...KEEPING WESTERLY
WINDS GUSTY HERE.
DRIZZLE/FOG/BLOWING SNOW TONIGHT...THE EXPANSION OF DRIZZLE
ACROSS THE AREA EARLY THIS AFTERNOON LINED UP WELL WITH SATURATION
AND SOME WEAK ADIABATIC OMEGA ON THE 275K AND 280K SURFACES.
CONTINUING TO LOOK AT NEAR-SURFACE LAYERS INTO TONIGHT ON THE
RUC...THE PROJECTION IS FOR THE GREATER LIFT IN SATURATION TO MOVE
NORTH OF THE AREA BY EARLY TO MID EVENING. IN ADDITION...THE
SURFACE TEMPERATURES ARE EXPECTED TO BE ABOVE FREEZING IN ALL
AREAS BY 6 PM. IN THE DIRECT PATH OF THE LOW...TOWARDS
NORTHWEST/NORTH CENTRAL IL...THE WINDS WILL ACTUALLY BEGIN TO
DECREASE WITHIN THE INFLECTION IN THE PRESSURE PATTERN. THIS MAY
ALLOW CURRENT VISIBILITY TO FURTHER REDUCE FOR SOME DENSE FOG. AT
THIS POINT HAVE JUST HIGHLIGHTED WITH AREAS OF FOG TONIGHT. EXPECT
THAT WITH THE WINDS FORECAST TONIGHT SOME OF THIS SHALLOW
BLOWING/DRIFTING WILL CONTINUE IN RURAL AREAS. WILL MENTION IN THE
FORECAST AND MONITOR CLOSELY.
THUNDERSTORM CHANCES TONIGHT...AFTER A PRECIPITABLE WATER OF ONLY
0.20 ON THE MORNING ILX SOUNDING...A SIGNIFICANT REBOUND TO NEAR
1.1 INCHES IS EXPECTED TONIGHT ACROSS CENTRAL AND EASTERN IL INTO
IN. THIS IS PART OF AN ANOMALOUSLY STRONG LOW LEVEL JET...WHICH THE
22.12 NAM HAD AT SEVEN STANDARDIZED ANOMALIES ABOVE NORMAL. THIS
STRONG WIND FIELD IS WHAT WOULD GIVE ANY THUNDERSTORMS THE CHANCE
TO BE SEVERE...COMPENSATING FOR LIMITED LOW-LEVEL
INSTABILITY/FAVORABLE LAPSE RATES. MARGINAL INSTABILITY ALOFT IS
PRESENT...AT 500-1000 J/KG IN THE FAR SOUTHEAST/...HELPED BY
STRONG DIFFERENTIAL THETA-E ADVECTION WITH THE DRY SLOT INTRUSION.
THIS OVERRIDES THE SURFACE FOCUS OF A COLD FRONT /AND POSSIBLY A
PRE-FRONTAL TROUGH JUST AHEAD OF THIS/...WHICH SHOULD HELP
CONVECTION TO DEVELOP AND EVOLVE DURING THE 7 PM TO 10 PM TIME
ACROSS SOUTHWEST INTO CENTRAL IL.
BOUNDARY LAYER DEW POINTS IN EXCESS OF 50F ARE PROJECTED BY THE
NAM/GFS TO BE NEAR THE SOUTHEAST FORECAST AREA EDGE...WHICH WILL
KEEP THE LOWER PROFILES MOIST BASED ON FORECAST SOUNDINGS. GIVEN
THE VERY CLOSE PROXIMITY OF THE SNOW COVER EDGE BASED ON THIS
MORNINGS OBSERVATIONS...EVEN HIGHER TEMPERATURE AND DEW POINTS
/BUT WITH THE SAME LOW TEMP AND DEW POINT SPREADS/ MAY BE SEEN
INTO THE SOUTHEAST FORECAST AREA. THIS SETUP WOULD FURTHER HELP
FOR WINDS TO PUNCH THE INVERSION AND MAKE IT TO THE SURFACE WITHIN
SHOWERS AND ESPECIALLY ORGANIZED THUNDERSTORMS. FORECAST NAM
SOUNDINGS AT CHAMPAIGN SHOW ALMOST 70 KTS AND 3000 FT...SO PLENTY
AVAILABLE TO MIX DOWN. THIS SETUP WILL NEED TO BE WATCHED TOO FOR
THE CHANCE OF A TORNADO AS FAR NORTH AS OUR SOUTHEAST FORECAST
AREA...AS FORECAST PROFILES AND SYNOPTICS APPROACH THOSE THAT CAN
PRODUCE COOL SEASON EPISODES.
TO THE NORTH OF THE SEVERE CONVECTIVE THREAT...RAIN SHOWERS ARE
EXPECTED WITH POTENTIAL THUNDER. SOME OF THE RAINFALL RATES COULD
BE TEMPORARILY HEAVY...WHICH COULD FURTHER AGGRAVATE RUNOFF
ALREADY HEIGHTENED FROM SNOW MELT TONIGHT.
MONDAY...THE COLD AIR ADVECTION WILL WRAP IN QUICKLY BEHIND THE
FRONT. PARAMETERS FOR GUSTY WINDS...SUCH AS STEEPENED LOW-LEVEL
LAPSE RATES AND STRONG LOW-LEVEL Q-VECTOR DIVERGENCE...ARE BEST
SEEN IN THE SOUTHERN FORECAST AREA. WIND GUSTS TO NEAR 40 MPH ARE
EXPECTED AND IT IS POSSIBLE A WIND ADVISORY WILL BE NEEDED IN
TIME. THE SOUTHERN PART OF THE OVERALL UPPER TROUGH WILL MOVE
ACROSS THE AREA...LIKELY PRODUCING SOME SNOW FOR NORTHERN AREAS.
SOME MINOR ACCUMULATION UP TO POSSIBLY AN INCH COULD OCCUR NEAR
THE STATE LINE. BY MID TO LATE AFTERNOON...DEEP NVA IS FORECAST
WHICH SHOULD END ANY LIGHT SNOW/FLURRIES. CLOUDS WILL BE SLOWER TO
CLEAR...WITH SOME STILL HOLDING ON IN NORTHERN AND EASTERN AREAS
ON TUESDAY MORNING.
BEYOND...LITTLE CHANGES MADE TO THIS PORTION OF THE
FORECAST...WHICH LOOKS RELATIVE QUIET COMPARED TO THE PAST TEN
DAYS. A BLEND OF THE BETTER PERFORMING MODELS AND THE GOING FORECAST
WAS PRUDENT AT THIS TIME.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* VARIABLE CIGS/VSBY WITH PERIOD OF MVFR/VFR OCCURRING NOW BUT
IFR/LIFR EXPECTED TO RETURN...BUT TIMING IS NOT CLEAR.
* ANOTHER ROUND OF TS POSSIBLE STARTING AROUND 10Z.
* WINDS BECOMING LIGHT SSE WITH APPROACH OF SFC LOW LATE TONIGHT.
* WINDS BECOMING WEST AND GUSTING TO/ABOVE 30 KTS AT TIMES MONDAY
AFTERNOON.
* GRADUAL IMPROVEMENT IN CIG/VIS TRENDS MONDAY...THOUGH SNOW
SHOWERS POSSIBLE THROUGH MID AFTERNOON.
MDB
//DISCUSSION...UPDATED 08Z...
BULK OF THE SHRA/TSRA NOW OFF TO THE EAST OF THE TERMINALS BUT HAS
CAUSED HAVOC WITH CIGS/VSBY IN ITS WAKE. CORRIDOR OF MVFR AND EVEN
VFR CIGS/VSBY NOW EXTENDS EAST OF A LINE FROM APPROX SPI-PNT-ORD
WITH LIFR/VLIFR TO THE WEST. EXPECT THAT IFR/LIFR CONDITIONS WILL
RETURN TO ORD/MDW/GYY AT SOME POINT IN THE NEXT FEW HOURS GIVEN
THE APPROACH OF THE LOW AND WEAKENING LOW SURFACE FLOW ALLOWING
FOG/CIGS TO REDEVELOP/EXPAND BACK EAST. HOWEVER IT IS NOT CLEAR
HOW LONG THIS WILL TAKE. ANOTHER ROUND OF SHRA/TSRA IS CURRENTLY
APPROACHING RFD AND THE EXTREME WESTERN CHI METRO AT 0840Z AND
WILL QUICKLY LIFT NORTHEASTWARD. COVERAGE IS MUCH MORE SCATTERED
THAN EARLIER ROUND BUT BRIEF TS MAY OCCUR.
FROM 06Z...
RATHER COMPLICATED AVIATION WEATHER SCENARIO THROUGH MONDAY
MORNING AS STRONG LOW PRESSURE SYSTEM MOVES ACROSS THE FORECAST
AREA. LOW CIGS...REDUCED VSBY IN FOG...RA/TSRA ALL FACTORS FOR
TERMINALS THROUGH DAYBREAK.
DEEP LOW PRESSURE WAS LOCATED OVER FAR NORTHEAST MISSOURI AT
05Z...IN ASSOCIATION WITH A STRONG UPPER LEVEL DISTURBANCE LIFTING
THROUGH THE MID-MISSISSIPPI VALLEY. UNSEASONABLY WARM/MOIST AIR
CONTINUED TO SURGE NORTH INTO THE FORECAST AREA ALONG AND SOUTH OF A
WARM FRONT WHICH EXTENDED ACROSS CENTRAL/NORTHERN IL AND IND. THIS
WARM/MOIST AIR LIFTING ACROSS COLD GROUND AND SNOW COVER ACROSS
THE REGION HAS LED TO DEVELOPMENT OF EXTENSIVE IFR/LIFR STRATUS
AND FOG...AND HAS RESULTED IN SUFFICIENT ELEVATED INSTABILITY TO
PRODUCE THUNDERSTORMS AS FAR NORTH AS NORTHEAST ILLINOIS AND
SOUTHERN LAKE MICHIGAN.
SURFACE LOW IS EXPECTED TO LIFT NORTHEAST ACROSS NORTHERN ILLINOIS
THROUGH THE REMAINDER OF THE OVERNIGHT HOURS...PASSING JUST NORTH
OF CHICAGO AROUND SUNRISE. THIS WILL KEEP MUCH OF FORECAST AREA IN
VERY MOIST LOW LEVEL ENVIRONMENT THROUGH MORNING...SUPPORTING
CONTINUED LOW CIGS AND FOG. WELL-ORGANIZED AREA OF RAIN AND
EMBEDDED THUNDERSTORMS OVER EASTERN IL AND IL/IN STATE LINE REGION
AT THIS TIME SHOULD CONTINUE TO MOVE EAST/NORTHEAST OVER THE NEXT
FEW HOURS...AND MAY ACTUALLY IMPROVE VISIBILITY FOR A TIME AT TAF
SITES. AM CONCERNED HOWEVER THAT AS RAIN WEAKENS DURING THE PRE-
DAWN HOURS THAT CIGS/VIS MAY AGAIN LOWER INTO SOLID LIFR...
ESPECIALLY WITH WINDS DECREASING IN THE WEAKER PRESSURE GRADIENT
NEAR THE CENTER OF THE APPROACHING SFC LOW. ALSO...A SMALL BUT
PERSISTENT AREA OF SHRA/TSRA OVER NORTHEAST MO WITH THE UPPER LOW
CENTER WILL LIKELY LIFT NORTHEAST ACROSS FAR NORTHERN IL WITH THE
LOW THROUGH 12Z OR SO. THIS MAY BRING ANOTHER ROUND OF MORE
ISOLATED TS TO NORTHERN IL TERMINALS TOWARD MORNING.
ONCE SFC LOW PASSES EARLY MONDAY MORNING...WINDS WILL SHIFT TO THE
WEST AND BEGIN TO INCREASE...AS THE GRADIENT TIGHTENS BEHIND THE
DEPARTING LOW AND COLD ADVECTION STRENGTHENS. THIS WILL ALLOW FOR
GRADUAL IMPROVEMENT IN VIS AND CIGS TO MVFR RANGE DURING THE DAY.
ANY LINGERING LIGHT RAIN/SHOWERS WILL LIKELY CHANGE TO LIGHT SNOW
BY LATE MORNING/MIDDAY...AND MAY LAST THROUGH MID AFTERNOON OR SO
BEFORE DIMINISHING TO FLURRIES AND ENDING. STEEPENING LOW LEVEL
LAPSE RATES IN COLDER AIR COMBINED WITH STRONG PRESSURE GRADIENT
IS EXPECTED TO RESULT IN WINDY CONDITIONS MONDAY...WITH GUSTS
INCREASING TO AROUND OR JUST ABOVE 30 KTS BY MONDAY AFTERNOON.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* MEDIUM CONFIDENCE THAT IFR/LIFR WILL RETURN AT SOME POINT IN THE
NEXT FEW HOURS BUT LOW CONFIDENCE IN TIMING.
* MEDIUM CONFIDENCE IN ADDITIONAL TSRA STARTING AROUND 10Z.
* MEDIUM CONFIDENCE IN WIND DETAILS EARLY MONDAY NEAR SFC LOW CENTER.
* MEDIUM-HIGH CONFIDENCE IN IMPROVING CIG/VIS MONDAY AND GUSTY
WEST WINDS AND LIGHT SNOW SHOWERS.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...SLIGHT CHANCE OF SNOW SHOWERS LATE...MAINLY VFR.
SATURDAY...VFR.
RATZER
&&
.MARINE...
240 PM CST
DEEP AREA OF LOW PRESSURE WILL LIFT NORTH ACROSS LAKE MICHIGAN
OVERNIGHT WITH STRONG SOUTHERLY WINDS AHEAD OF THE LOW BECOMING
SOUTHWEST AS THE LOW SWEEPS ACROSS THE LAKE. LOW END GALES ARE
POSSIBLE ACROSS CENTRAL PORTIONS OF THE LAKE THROUGH THIS
EVENING...AND WILL ADVECT MOIST DEWPOINTS OVER THE LAKE SETTING UP
THE POTENTIAL FOR DENSE FOG...AS WELL AS THUNDERSTORMS ACROSS THE
SOUTHERN PORTIONS OF THE LAKE. EXPECT A BRIEF LULL IN THE GALES AS
THE PRESSURE GRADIENT BECOMES MORE BAGGY NEAR THE LOW CENTER...
BEFORE STRONGER GALES RESUME MONDAY MORNING. COLD AIR SWEEPING
ACROSS THE LAKE WILL ALLOW FOR DEEP MIXING AND 40 TO 45 KT GALES ARE
EXPECTED...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE. REPLACED
THE SMALL CRAFT ADVISORY FOR THE NEARSHORE WATERS WITH A GALE WATCH
FOR MONDAY. WINDS BEGIN TO COME DOWN EARLY TUESDAY AS THE LOW LIFTS
AWAY FROM THE GREAT LAKES INTO QUEBEC AND HIGH PRESSURE BEGINS TO
BUILD INTO THE WESTERN GREAT LAKES REGION. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM MONDAY.
GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...2 PM MONDAY TO 2 AM TUESDAY.
GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ868...8 PM MONDAY TO 2 AM
TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1143 PM CST SUN JAN 22 2012
.DISCUSSION...
910 PM CST
NOT MUCH CHANGE TO THE GOING FORECAST THIS EVENING. TRENDS ARE
PANNING OUT AS EXPECTED AND ARE IN A MONITOR MODE WITH THE
CONVECTION TO THE SOUTH. ACROSS THE AREA...VAD WIND PROFILE SHOW
WINDS AT 1KFT GENERALLY OUT OF THE SOUTHEAST AT 20 OR SO KT...AND
AT 3KFT...SOUTH TO SOUTHWEST AT 50 TO 55KT. MODEL PROGS SHOW THAT
THE LLJ WILL CONTINUE TO INCREASE AND WILL GIVE ANY STORMS THAT
WORK THROUGH...THE POTENTIAL BE STRONG. MID LEVEL LAPSE RATES HAD
BEEN PROGGED TO RANGE FROM 6-7.5 C/KM THIS EVE...BUT RUC ANALYSIS
SHOWED THAT BEING ON THE WANE AS OF 03Z...WITH THE HIGHEST VALUES
SHIFTING EAST. DESPITE THE SURGE OF WARMTH AND
MOISTURE...CONVECTION WILL HAVE TO STRUGGLE AGAINST A STABLE
SURFACE AIRMASS. THE BEST FOCUS STILL SET TO REMAIN SOUTH FOR
SEVERE ACTIVITY...WITH THE BEST FOCUS LOCALLY...GENERALLY EAST OF
THE I-57 CORRIDOR THROUGH THE MIDNIGHT HOUR WHERE A FEW RUMBLES OF
THUNDER MAY BE HEARD. LATEST GRIDS AND ZONES ARE OUT. SHEA
//PREV DISCUSSION...
357 PM CST
JUST 48 HOURS AFTER A WINTER STORM...THE WEATHER WILL SWING
VIGOROUSLY THE OTHER WAY ACROSS THE MIDDLE OF THE COUNTRY
TONIGHT. MUCH OF THE ATTENTION ON THE FORECAST WAS SPENT ON THE
PRESENT THROUGH MONDAY...WITH CONCERNS ON DENSE FOG...INITIAL
FREEZING DRIZZLE...CONVECTION...GUSTY WINDS...AND SOME SNOW TO
ROUND IT OUT DURING MONDAY.
SYNOPSIS...THE WELL-DEFINED UPPER LOW IS TAKING BETTER SHAPE OVER
THE CENTRAL PLAINS THIS AFTERNOON...WITH SIGNS OF A STRONG MID-
LEVEL JET AND DRY SLOT DEVELOPING INTO THE OZARKS. THE SURFACE LOW
AT 992 MB OVER EASTERN KS HAS BEEN SLIGHTLY DEEPER THAN SOME OF
THE MODELS HAD INDICATED FOR THIS AFTERNOON. THE PRIMARY SURFACE
THETA-E GRADIENT IS DRAPED FROM NORTHERN MO INTO SOUTHERN IL.
LOW-LEVEL FLOW HAS BEEN INCREASING OVER THE FORECAST AREA...WHICH
IN PLACES HAS CAUSED SOME BLOWING AND DRIFTING OF THE LIGHT AND
FLUFFY SNOW SEEN THIS PAST FRIDAY. TEMPERATURES HAVE RESPONDED TO
THE RETURN FLOW AS WELL...CLIMBING INTO THE MID 30S ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA. INCREASING SURFACE
TEMPERATURES AND DEW POINTS WILL CONTINUE INTO TONIGHT...WITH THE
PRIMARY GRADIENT MARCHING MORE QUICKLY NORTH THROUGH IL AND IN
THAN IT HAD TODAY AS CYCLOGENESIS FURTHER OCCURS. THE SURFACE LOW
WILL SHIFT NORTHEAST TO NEAR THE QUAD CITIES BY 3 AM AS THE UPPER
TROUGH BECOMES NEGATIVELY TILED. THE COLD FRONT WILL PUSH QUICKLY
FROM SOUTHWEST TO NORTHEAST ACROSS THE FORECAST AREA BETWEEN 3 AM
AND 7 AM...WITH LIKELY AN AREA OF SHOWERS AND CONVECTION AHEAD OF
IT BETWEEN 10 PM AND 3 AM. THE LOW WILL THEN SHIFT ON TO THE
NORTHERN PART OF LAKE MICHIGAN BY LATE MONDAY...KEEPING WESTERLY
WINDS GUSTY HERE.
DRIZZLE/FOG/BLOWING SNOW TONIGHT...THE EXPANSION OF DRIZZLE
ACROSS THE AREA EARLY THIS AFTERNOON LINED UP WELL WITH SATURATION
AND SOME WEAK ADIABATIC OMEGA ON THE 275K AND 280K SURFACES.
CONTINUING TO LOOK AT NEAR-SURFACE LAYERS INTO TONIGHT ON THE
RUC...THE PROJECTION IS FOR THE GREATER LIFT IN SATURATION TO MOVE
NORTH OF THE AREA BY EARLY TO MID EVENING. IN ADDITION...THE
SURFACE TEMPERATURES ARE EXPECTED TO BE ABOVE FREEZING IN ALL
AREAS BY 6 PM. IN THE DIRECT PATH OF THE LOW...TOWARDS
NORTHWEST/NORTH CENTRAL IL...THE WINDS WILL ACTUALLY BEGIN TO
DECREASE WITHIN THE INFLECTION IN THE PRESSURE PATTERN. THIS MAY
ALLOW CURRENT VISIBILITY TO FURTHER REDUCE FOR SOME DENSE FOG. AT
THIS POINT HAVE JUST HIGHLIGHTED WITH AREAS OF FOG TONIGHT. EXPECT
THAT WITH THE WINDS FORECAST TONIGHT SOME OF THIS SHALLOW
BLOWING/DRIFTING WILL CONTINUE IN RURAL AREAS. WILL MENTION IN THE
FORECAST AND MONITOR CLOSELY.
THUNDERSTORM CHANCES TONIGHT...AFTER A PRECIPITABLE WATER OF ONLY
0.20 ON THE MORNING ILX SOUNDING...A SIGNIFICANT REBOUND TO NEAR
1.1 INCHES IS EXPECTED TONIGHT ACROSS CENTRAL AND EASTERN IL INTO
IN. THIS IS PART OF AN ANOMALOUSLY STRONG LOW LEVEL JET...WHICH THE
22.12 NAM HAD AT SEVEN STANDARDIZED ANOMALIES ABOVE NORMAL. THIS
STRONG WIND FIELD IS WHAT WOULD GIVE ANY THUNDERSTORMS THE CHANCE
TO BE SEVERE...COMPENSATING FOR LIMITED LOW-LEVEL
INSTABILITY/FAVORABLE LAPSE RATES. MARGINAL INSTABILITY ALOFT IS
PRESENT...AT 500-1000 J/KG IN THE FAR SOUTHEAST/...HELPED BY
STRONG DIFFERENTIAL THETA-E ADVECTION WITH THE DRY SLOT INTRUSION.
THIS OVERRIDES THE SURFACE FOCUS OF A COLD FRONT /AND POSSIBLY A
PRE-FRONTAL TROUGH JUST AHEAD OF THIS/...WHICH SHOULD HELP
CONVECTION TO DEVELOP AND EVOLVE DURING THE 7 PM TO 10 PM TIME
ACROSS SOUTHWEST INTO CENTRAL IL.
BOUNDARY LAYER DEW POINTS IN EXCESS OF 50F ARE PROJECTED BY THE
NAM/GFS TO BE NEAR THE SOUTHEAST FORECAST AREA EDGE...WHICH WILL
KEEP THE LOWER PROFILES MOIST BASED ON FORECAST SOUNDINGS. GIVEN
THE VERY CLOSE PROXIMITY OF THE SNOW COVER EDGE BASED ON THIS
MORNINGS OBSERVATIONS...EVEN HIGHER TEMPERATURE AND DEW POINTS
/BUT WITH THE SAME LOW TEMP AND DEW POINT SPREADS/ MAY BE SEEN
INTO THE SOUTHEAST FORECAST AREA. THIS SETUP WOULD FURTHER HELP
FOR WINDS TO PUNCH THE INVERSION AND MAKE IT TO THE SURFACE WITHIN
SHOWERS AND ESPECIALLY ORGANIZED THUNDERSTORMS. FORECAST NAM
SOUNDINGS AT CHAMPAIGN SHOW ALMOST 70 KTS AND 3000 FT...SO PLENTY
AVAILABLE TO MIX DOWN. THIS SETUP WILL NEED TO BE WATCHED TOO FOR
THE CHANCE OF A TORNADO AS FAR NORTH AS OUR SOUTHEAST FORECAST
AREA...AS FORECAST PROFILES AND SYNOPTICS APPROACH THOSE THAT CAN
PRODUCE COOL SEASON EPISODES.
TO THE NORTH OF THE SEVERE CONVECTIVE THREAT...RAIN SHOWERS ARE
EXPECTED WITH POTENTIAL THUNDER. SOME OF THE RAINFALL RATES COULD
BE TEMPORARILY HEAVY...WHICH COULD FURTHER AGGRAVATE RUNOFF
ALREADY HEIGHTENED FROM SNOW MELT TONIGHT.
MONDAY...THE COLD AIR ADVECTION WILL WRAP IN QUICKLY BEHIND THE
FRONT. PARAMETERS FOR GUSTY WINDS...SUCH AS STEEPENED LOW-LEVEL
LAPSE RATES AND STRONG LOW-LEVEL Q-VECTOR DIVERGENCE...ARE BEST
SEEN IN THE SOUTHERN FORECAST AREA. WIND GUSTS TO NEAR 40 MPH ARE
EXPECTED AND IT IS POSSIBLE A WIND ADVISORY WILL BE NEEDED IN
TIME. THE SOUTHERN PART OF THE OVERALL UPPER TROUGH WILL MOVE
ACROSS THE AREA...LIKELY PRODUCING SOME SNOW FOR NORTHERN AREAS.
SOME MINOR ACCUMULATION UP TO POSSIBLY AN INCH COULD OCCUR NEAR
THE STATE LINE. BY MID TO LATE AFTERNOON...DEEP NVA IS FORECAST
WHICH SHOULD END ANY LIGHT SNOW/FLURRIES. CLOUDS WILL BE SLOWER TO
CLEAR...WITH SOME STILL HOLDING ON IN NORTHERN AND EASTERN AREAS
ON TUESDAY MORNING.
BEYOND...LITTLE CHANGES MADE TO THIS PORTION OF THE
FORECAST...WHICH LOOKS RELATIVE QUIET COMPARED TO THE PAST TEN
DAYS. A BLEND OF THE BETTER PERFORMING MODELS AND THE GOING FORECAST
WAS PRUDENT AT THIS TIME.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LIFR CIG/VIS CONDITIONS...THOUGH SOME INCREASE IN VSBY WITH
HEAVIER SHRA/TSRA.
* A COUPLE PERIODS OF TSRA POSSIBLE THRU ABOUT 07-08Z...AND AGAIN
TOWARD 12Z.
* WINDS BECOMING LIGHT SSE WITH APPROACH OF SFC LOW LATE TONIGHT.
* WINDS BECOMING WEST AND GUSTING TO/ABOVE 30 KTS AT TIMES MONDAY
AFTERNOON.
* GRADUAL IMPROVEMENT IN CIG/VIS TRENDS MONDAY...THOUGH SNOW
SHOWERS POSSIBLE THROUGH MID AFTERNOON.
RATZER
//DISCUSSION...UPDATED 06Z...
RATHER COMPLICATED AVIATION WEATHER SCENARIO THROUGH MONDAY
MORNING AS STRONG LOW PRESSURE SYSTEM MOVES ACROSS THE FORECAST
AREA. LOW CIGS...REDUCED VSBY IN FOG...RA/TSRA ALL FACTORS FOR
TERMINALS THROUGH DAYBREAK.
DEEP LOW PRESSURE WAS LOCATED OVER FAR NORTHEAST MISSOURI AT
05Z...IN ASSOCIATION WITH A STRONG UPPER LEVEL DISTURBANCE LIFTING
THROUGH THE MID-MISSISSIPPI VALLEY. UNSEASONABLY WARM/MOIST AIR
CONTINUED TO SURGE NORTH INTO THE FORECAST AREA ALONG AND SOUTH OF A
WARM FRONT WHICH EXTENDED ACROSS CENTRAL/NORTHERN IL AND IND. THIS
WARM/MOIST AIR LIFTING ACROSS COLD GROUND AND SNOW COVER ACROSS
THE REGION HAS LED TO DEVELOPMENT OF EXTENSIVE IFR/LIFR STRATUS
AND FOG...AND HAS RESULTED IN SUFFICIENT ELEVATED INSTABILITY TO
PRODUCE THUNDERSTORMS AS FAR NORTH AS NORTHEAST ILLINOIS AND
SOUTHERN LAKE MICHIGAN.
SURFACE LOW IS EXPECTED TO LIFT NORTHEAST ACROSS NORTHERN ILLINOIS
THROUGH THE REMAINDER OF THE OVERNIGHT HOURS...PASSING JUST NORTH
OF CHICAGO AROUND SUNRISE. THIS WILL KEEP MUCH OF FORECAST AREA IN
VERY MOIST LOW LEVEL ENVIRONMENT THROUGH MORNING...SUPPORTING
CONTINUED LOW CIGS AND FOG. WELL-ORGANIZED AREA OF RAIN AND
EMBEDDED THUNDERSTORMS OVER EASTERN IL AND IL/IN STATE LINE REGION
AT THIS TIME SHOULD CONTINUE TO MOVE EAST/NORTHEAST OVER THE NEXT
FEW HOURS...AND MAY ACTUALLY IMPROVE VISIBILITY FOR A TIME AT TAF
SITES. AM CONCERNED HOWEVER THAT AS RAIN WEAKENS DURING THE PRE-
DAWN HOURS THAT CIGS/VIS MAY AGAIN LOWER INTO SOLID LIFR...
ESPECIALLY WITH WINDS DECREASING IN THE WEAKER PRESSURE GRADIENT
NEAR THE CENTER OF THE APPROACHING SFC LOW. ALSO...A SMALL BUT
PERSISTENT AREA OF SHRA/TSRA OVER NORTHEAST MO WITH THE UPPER LOW
CENTER WILL LIKELY LIFT NORTHEAST ACROSS FAR NORTHERN IL WITH THE
LOW THROUGH 12Z OR SO. THIS MAY BRING ANOTHER ROUND OF MORE
ISOLATED TS TO NORTHERN IL TERMINALS TOWARD MORNING.
ONCE SFC LOW PASSES EARLY MONDAY MORNING...WINDS WILL SHIFT TO THE
WEST AND BEGIN TO INCREASE...AS THE GRADIENT TIGHTENS BEHIND THE
DEPARTING LOW AND COLD ADVECTION STRENGTHENS. THIS WILL ALLOW FOR
GRADUAL IMPROVEMENT IN VIS AND CIGS TO MVFR RANGE DURING THE DAY.
ANY LINGERING LIGHT RAIN/SHOWERS WILL LIKELY CHANGE TO LIGHT SNOW
BY LATE MORNING/MIDDAY...AND MAY LAST THROUGH MID AFTERNOON OR SO
BEFORE DIMINISHING TO FLURRIES AND ENDING. STEEPENING LOW LEVEL
LAPSE RATES IN COLDER AIR COMBINED WITH STRONG PRESSURE GRADIENT
IS EXPECTED TO RESULT IN WINDY CONDITIONS MONDAY...WITH GUSTS
INCREASING TO AROUND OR JUST ABOVE 30 KTS BY MONDAY AFTERNOON.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN IFR/OCNL LIFR CONDITIONS OVERNIGHT...THOUGH
LOW CONFIDENCE IN DETAILS OF VARIABLE CIG/VIS IN SHRA/TSRA.
* MEDIUM-LOW CONFIDENCE IN ADDITIONAL TSRA THROUGH 12Z MONDAY.
* MEDIUM CONFIDENCE IN WIND DETAILS EARLY MONDAY NEAR SFC LOW CENTER.
* MEDIUM-HIGH CONFIDENCE IN IMPROVING CIG/VIS MONDAY AND GUSTY
WEST WINDS AND LIGHT SNOW SHOWERS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...SLIGHT CHANCE OF SNOW SHOWERS LATE...MAINLY VFR.
SATURDAY...VFR.
RATZER
&&
.MARINE...
240 PM CST
DEEP AREA OF LOW PRESSURE WILL LIFT NORTH ACROSS LAKE MICHIGAN
OVERNIGHT WITH STRONG SOUTHERLY WINDS AHEAD OF THE LOW BECOMING
SOUTHWEST AS THE LOW SWEEPS ACROSS THE LAKE. LOW END GALES ARE
POSSIBLE ACROSS CENTRAL PORTIONS OF THE LAKE THROUGH THIS
EVENING...AND WILL ADVECT MOIST DEWPOINTS OVER THE LAKE SETTING UP
THE POTENTIAL FOR DENSE FOG...AS WELL AS THUNDERSTORMS ACROSS THE
SOUTHERN PORTIONS OF THE LAKE. EXPECT A BRIEF LULL IN THE GALES AS
THE PRESSURE GRADIENT BECOMES MORE BAGGY NEAR THE LOW CENTER...
BEFORE STRONGER GALES RESUME MONDAY MORNING. COLD AIR SWEEPING
ACROSS THE LAKE WILL ALLOW FOR DEEP MIXING AND 40 TO 45 KT GALES ARE
EXPECTED...ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE. REPLACED
THE SMALL CRAFT ADVISORY FOR THE NEARSHORE WATERS WITH A GALE WATCH
FOR MONDAY. WINDS BEGIN TO COME DOWN EARLY TUESDAY AS THE LOW LIFTS
AWAY FROM THE GREAT LAKES INTO QUEBEC AND HIGH PRESSURE BEGINS TO
BUILD INTO THE WESTERN GREAT LAKES REGION. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM MONDAY.
GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...2 PM MONDAY TO 2 AM TUESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...8 PM MONDAY TO 4 AM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
545 PM CST TUE JAN 24 2012
.AVIATION...
GENERALLY VFR CONDITIONS WITH PERIODS OF MVFR AND POSSIBLY BRIEF
INTERVALS IFR CONDITIONS DUE TO GROUND FOG BETWEEN 02-14Z TONIGHT.
SCATTERED TO BROKEN COVERAGE OF MID TO HIGH CLOUDS TO STREAM ACROSS
THE AREA INTO WEDNESDAY FROM SOUTH PLAINS DISTURBANCE. WINDS TO BE
VERY LIGHT TO CALM THAT SUPPORTS SOME TERMINALS TONIGHT TO DROP TO
2-5 MILES IN FOG. VEIL OF HIGH CLOUDS SUGGESTS DENSE FOG UNLIKELY
BY NOT ALLOWING FOR GOOD RADIATIONAL COOLING. VISIBILITIES TO
IMPROVE BY MID TO LATE MORNING IF NOT ALREADY 7 MILES TO 7 PLUS
MILES AS SE TO E WINDS OF 5-10 MPH OCCUR. ..NICHOLS..
&&
.PREV DISCUSSION... /ISSUED 310 PM CST MON JAN 24 2012/
SYNOPSIS...
12Z UA ANALYSIS HAS AN OCCLUDED EXTRATROPICAL CYCLONE OVER JAMES BAY
WITH AN 850MB COLD FRONT INTO THE OHIO VALLEY AND BACK INTO NORTHERN
MISSOURI. A RESPECTABLE SHORTWAVE WAS MOVING EAST OUT OF THE CENTRAL
ROCKIES WHILE ANOTHER STRONG STORM SYSTEM ORGANIZES OVER NEW MEXICO.
SATELLITE TRENDS THROUGH MID AFTERNOON SHOW CLEARING BEHIND A
DEPARTING SHORTWAVE ACROSS THE WESTERN GREAT LAKES WHILE MOISTURE
REMAINS TRAPPED UNDER THE INVERSION ACROSS IOWA. HIGH AND MID CLOUDS
WERE STREAMING EAST FROM THE PLAINS IN ADVANCE OF THE SYSTEMS IN THE
CENTRAL AND SOUTHERN ROCKIES.
18Z SFC ANALYSIS HAS HIGH PRESSURE FROM MINNESOTA THROUGH CENTRAL
IOWA AND THEN INTO THE LOWER MISSISSIPPI VALLEY. A WEAK LOW WAS
NORTH OF KVTN WITH TROFS EXTENDING NORTH AND SOUTH OF IT. THE
SOUTHERN STREAM STORM SYSTEM WAS IN THE BIG BEND OF TEXAS. DEW
POINTS WERE IN THE TEENS AND 20S ACROSS MUCH OF THE MIDWEST AND
PLAINS WITH 30S AND HIGH DEW POINTS FROM THE OHIO VALLEY WEST INTO
THE SOUTHERN PLAINS.
SHORT TERM...TONIGHT AND WEDNESDAY...
BASED ON SATELLITE CLOUDS TRENDS...THOSE AREAS THAT ARE STILL CLOUDY
WILL LIKELY REMAIN SO THROUGH SUNSET. THE PROXIMITY OF THE SFC RIDGE
COMBINED WITH THE ARRIVAL OF HIGH CLOUDS SHOULD KEEP THOSE CLOUDS IN
PLACE THROUGH SUNSET.
UNFORTUNATELY...THE STRAIGHT FORWARD FCST OF DRY CONDITIONS FOR
TONIGHT/WEDNESDAY HAS BECOME MORE COMPLICATED.
STRONG WAA FROM THE SFC TO 850MB IS OCCURRING IN THE PLAINS FROM A
LLJ WHICH IS RESULTING IN CONVERGENCE ACROSS NORTHERN KS/SOUTHERN NE
WHICH IS AIDING IN CLOUD DEVELOPMENT. RUC TRENDS IN WHICH THE
WRF/GFS AGREE SHOWS 850-700MB AND EVENTUALLY 1000-850MB CONDENSATION
PRESSURE DEFICITS LOWERING LATER THIS AFTERNOON DUE TO STRONG
FRONTOGENETICAL FORCING INDICATING PRECIPITATION. TRENDS FROM THE
RUC AND OTHER MODELS ARE TO MOVE THIS WING OF WAA PRECIPITATION INTO
IOWA THIS EVENING WITH A NORTHEAST MOVEMENT OVERNIGHT. THE HEAVY
RAIN AND LIFT TOOLS SHOW A SIMILAR SIGNAL. IF SUCH A SCENARIO WAS
OCCURRING ROUGHLY 5 MONTHS FROM NOW THESE SIGNALS WOULD POINT TO AN
MCS DEVELOPING IN THE PLAINS AND MOVING NORTHEAST.
THE WRF/GFS SHOW THE LOWEST 850-700MB CONDENSATION PRESSURE DEFICITS
JUST MISSING THE CWFA VERY LATE TONIGHT AND WEDNESDAY MORNING. THE
1000-850MB CONDENSATION PRESSURE DEFICITS ARE HIGHER SUGGESTING
ENOUGH DRY AIR WOULD BE IN PLACE TO PREVENT ANY PRECIPITATION FROM
HAPPENING. HOWEVER...SINCE THE MODELS ARE NOT HANDLING THE CURRENT
LOW CLOUDS ONE MUST BE CAUTIOUS ON THIS ASSUMPTION. GIVEN THE TRENDS
OF THE 18Z WRF RUN...WILL GO WITH THE IDEA THAT THE CWFA WILL REMAIN
DRY TONIGHT. HOWEVER...I WOULD NOT BE SURPRISED IF FLURRIES
DEVELOPED FROM HWY 20 ON NORTH AFTER 3 AM.
TEMPERATURES SHOULD QUICKLY DROP WITH SUNSET IN THE CLEAR AREAS THIS
EVENING. AS THE HIGH AND MID LEVEL CLOUDS ARRIVE THE DROP OFF SHOULD
LEVEL OFF AND MAY EVEN BEGIN A SLOW RISE THROUGH SUNRISE.
WEDNESDAY...FLURRIES MAY OR MAY NOT BE OCCURRING ALONG/NORTH OF HWY
20 DURING THE MORNING HOURS. OTHERWISE...DRY CONDITIONS WILL BE SEEN
THROUGH THE MORNING WITH PLENTY OF CLOUDS. WEDNESDAY AFTERNOON...THE
PRECIPITATION SHIELD FROM THE SOUTHERN STREAM SYSTEM WILL APPROACH
THE CWFA. CONDENSATION PRESSURE DEFICITS AND THE OVERALL FORCING
SUGGESTS THE NORTHERN LIMIT OF PRECIPITATION SHOULD BE FROM JUST
SOUTH OF KUIN TO ABOUT KAAA IN CENTRAL ILLINOIS. THUS DRY CONDITIONS
ARE EXPECTED ACROSS THE AREA DURING THE AFTERNOON HOURS.
.08..
LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY...FORECAST FOCUS
ON A SERIES OF SHORT WAVES MOVING THROUGH THE NORTHWEST FLOW BUT NO
SIGNIFICANT PRECIPITATION EXPECTED AT THIS TIME. TEMPERATURES TO
REMAIN A BIT ABOVE NORMAL BUT A SHOT OF COLDER AIR THIS WEEKEND.
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...SPLIT FLOW INITIALLY KEEPS
SOUTHERN STORM SYSTEM SOUTH OF THE DVN CWA AT MID WEEK.
ECM/GFS/NAM/GEM/UKMET ALL KEEP THE PRECIPITATION ASSOCIATED WITH
THIS SYSTEM SOUTH AND EAST OF THE CWA. PHASING TAKES PLACE CRANKING
UP A DECENT CYCLONE MOVING THROUGH THE OHIO VALLEY AND INTO NEW
ENGLAND LATE THIS WEEK. IN THE WAKE OF THIS SYSTEM NORTHWEST FLOW
TAKES OVER WITH A STRONG TROUGH DIVING INTO THE REGION FRIDAY AND
FRIDAY NIGHT. MOISTURE WILL BE LIMITED BUT ECM/NAM PAINTS THE
POTENTIAL FOR UP TO AN INCH OF SNOWFALL IN OUR SOUTHERN CWA. THE
GFS/GEM ARE MUCH DRIER. HOWEVER THE LOCATION OF THE AXIS OF THIS
SNOWFALL MAY CHANGE DEPENDING ON THE TRACK AND INTENSITY OF A STRONG
VORT MAX EXPECTED TO TRACK ACROSS THE AREA. MAX TEMPERATURES DURING
THIS TIME FRAME SHOULD BE IN THE 30S TO AROUND 40.
THIS WEEKEND...FOLLOWING THE PASSAGE OF THIS TROUGH COLDER AIR DUMPS
INTO THE MIDWEST. WILL BE BRISK ON SATURDAY WITH NORTHWEST WINDS
GUSTING TO 30 MPH PUTTING A BITE IN THE AIR. ANOTHER STRONG TROUGH
AND VORT MAX ARRIVES SATURDAY NIGHT BUT MOISTURE WILL BE EVEN MORE
LIMITED. HOWEVER SCATTERED FLURRIES ARE POSSIBLE DUE TO THE STRENGTH
OF THE SYSTEM BUT FOR NOW WILL NOT MENTION IN THE GRIDS WITH LOW
CONFIDENCE. MIN TEMPS SATURDAY NIGHT WILL DIP TO AROUND 10 ABOVE AT
INDEPENDENCE WITH MOST LOCATIONS IN THE TEENS. COLD ON SUNDAY WITH
MAX TEMPS ONLY IN THE 20S...BUT LOWER 30S IN OUR FAR SOUTH.
EARLY NEXT WEEK...ZONAL FLOW RETURNS WITH MILDER TEMPERATURES
REACHING INTO THE MID 30S NORTH TO MID 40S SOUTH. WAVE IN THE FLOW
TUESDAY INTO TUESDAY NIGHT MAY BRING A ROUND OF LIGHT RAIN TO THE
CWA...POSSIBLY CHANGING TO LIGHT SNOW AT THE TAIL END. THIS IS A
WEEK AWAY SO CONFIDENCE IN THE INTENSITY/TIMING AND QPF IS LOW.
.HAASE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
715 PM EST TUE JAN 24 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRING QUIET WEATHER FOR THE NEXT 24 HOURS BEFORE
A STORM SYSTEM MOVES IN FROM THE GULF COAST FOR WEDNESDAY NIGHT INTO
FRIDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
FOR THE EARLY EVENING UPDATE, OUR LATEST SOUNDING INDICATING LL
INVERSION HOLDING STRONG. MODEL DATA SHOWING NOTHING TO REALLY
ALLOW THE INVERSION TO BREAK DOWN OVERNIGHT. CURRENT HRRR MODEL
DATA KEEPS IN THE LOW CLOUDS AND DRIFTS THEM SOUTHWARD OVERNIGHT.
SO INCREASED THE COVERAGE OF THE LOW CLOUDS TO THE SOUTH. BECAUSE
OF THIS, ALSO RAISED THE OVERNIGHT LOWS A COUPLE OF DEGREES.
LOW CLOUD DECK SHOULD RETREAT NORTHWARD WED MORNING, AS WEAK
MID/UPPER LEVEL RIDGE MOVES OVER THE UPPER OHIO VALLEY. MID
LEVEL CLOUDS WILL THEN MOVE IN WEDNESDAY AFTERNOON. TEMPERATURES
NEAR CLIMATOLOGY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
LOW PRESSURE CURRENTLY OVER THE SOUTH CENTRAL UNITED STATES WILL
MAKE SLOW PROGRESS TO THE NORTHEAST WEDNESDAY NIGHT. AHEAD OF THE
SYSTEM...PRECIPITATION WILL BEGIN TO MOVE IN FROM THE SOUTHWEST.
MOST PRECIPITATION SHOULD REMAIN SOUTH OF THE MASON-DIXON LINE UNTIL
THURSDAY MORNING. MODEL SOUNDINGS SHOW TEMPERATURES CLOSE TO
FREEZING THROUGHOUT MOST OF THE PROFILE. AM CONCERNED THAT BETWEEN
CLOUD TOP TEMPERATURES ABOVE -10C AND SMALL WARM WEDGE SLIGHTLY
ABOVE THE SURFACE...PRECIPITATION MAY START AS FREEZING
RAIN...PRIMARILY NORTH OF THE MASON-DIXON LINE. AT THIS
POINT...STILL THINK THIS RISK IS RELATIVELY LOW...AND THAT FREEZING
RAIN WOULD NOT LAST MORE THAN A COUPLE OF HOURS IN ANY LOCATION.
TEMPERATURES WILL RISE INTO THE 40S...AND ALL PRECIPITATION WILL
CHANGE TO RAIN BY LATE MORNING.
LOW PRESSURE MOVING ACROSS CANADA WILL DRAG A COLD FRONT INTO THE
REGION...ENHANCING PRECIPITATION FROM THE SOUTH. PRECIPITATION
WILL CONTINUE INTO THURSDAY NIGHT...AND SHOULD COME TO AN END ON
FRIDAY. INVERSION LEVELS APPEAR TO BE TOO LOW TO SUPPORT LAKE
EFFECT/ENHANCED SNOW FRIDAY AFTERNOON.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BLEND OF ECMWF AND NAEFS MODEL OUTPUT SHOW PACIFIC COAST RIDGING IN
THE UPPER LEVEL JETSTREAM CAUSING TROUGHING ACROSS THE CANADIAN
PLAINS THIS WEEKEND. SO EXPECT UPPER OHIO VALLEY TEMPERATURES TO GO
COLDER THAN NORMAL SUNDAY IN THE WAKE OF THE PLAINS-BRED COLD
FRONTAL PASSAGE SATURDAY. SO THE COLD FRONTAL PASSAGE SATURDAY WILL
BE ACCOMPANIED BY BOTH RAIN AND SNOW SHOWERS, BUT THEN FOLLOWED BY
SCATTERED SNOW SHOWERS SUNDAY.
EARLY NEXT WEEK, THE MODELS SHOW THE SOUTHERN JETSTREAM BRANCH
GAINING MORE INFLUENCE, AND THIS IS REFLECTED IN UPPER OHIO VALLEY
TEMPERATURES MODERATING TUESDAY AHEAD OF AN INCOMING OKLAHOMA-BRED
LOW PRESSURE SYSTEM. HENCE THE SYSTEM`S WARM FRONTAL PASSAGE TUESDAY
MAY BE ACCOMPANIED BY MIXED PRECIPITATION.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
COLD POOL STRATOCU RMND ENTRENCHED OVR UPR OH VALLEY AS FAR SOUTH AS
THE I-70 CORRIDOR THIS EVE. GIVEN THE EXTENT OF THE MVFR BLANKET TO
THE N AND W...IN CONJUNCTION WITH NAM/RUC PROGGED CONTINUATION OF
NW FLOW ABOVE THE BNDRY LYR/MAINTENANCE OF THE INVERSION...WL
PERSIST WITH MVFR CONDITIONS/IFR FOR NRN ZONES THRU THE NGT.
BACKING WIND WL HERALD IMPROVEMENT BY MID MORNING ON WEDNESDAY.
OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...
VFR CONDITION ARE ANTICIPATED AS HIGH PRESSURE SLIDES ACRS THE
REGION AS TROUGH DVLPS OVR THE LOWER OHIO. MIXED PCPN/WIDESPREAD
RESTRICTIONS ARE EXPECTED FOR THURSDAY AND FRIDAY AS THAT TROUGH
MOVS E/NEWD. MORE RESTRICTIONS ARE POSSIBLE FOR THE WEEKEND AS THE
SYSTEMS CDFNT GENERATES SHRA AND SHSN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
519 PM EST MON JAN 23 2012
.SYNOPSIS...
RAIN SHOWERS WILL END THIS EVENING, WITH THE PASSAGE OF A STRONG
COLD FRONT. GUSTY WINDS WILL SUBSIDE LATER TONIGHT. MIDWEST HIGH
PRESSURE WILL FOLLOW WITH DRY, CHILLY CONDITIONS TUESDAY AND WEDNESDAY.
A COLD FRONT COMING EAST FROM THE ROCKIES WILL BRING A MIX OF RAIN
AND SNOW THURSDAY, AND COLDER TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
USED RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR MODEL OUTPUT
TO ADJUST TIMING OF COLD FRONTAL PASSAGE, AND ITS ASSOCIATED
BANDS OF SHOWERS, AND WIND GUST VALUES.
ONCE THE FRONT PASSES...TEMPERATURES WILL FALL QUICKLY
TONIGHT, AS ADJUSTED USING RECENT GFS LAMP AND HRRR MODEL OUTPUT.
BY LATE TONIGHT, ONLY REMAINING SHOWERS WILL ISOLATED ACROSS THE
I-80 CORRIDOR AND MOUNTAINS. INDICATED THESE CAN BE SNOW SHOWERS,
BUT AN INVERSION ALOFT MAY PRECLUDE ICE NUCLEATION.
HIGH PRESSURE WILL BEGIN TO MOVE IN FROM THE SOUTHWEST ON
TUESDAY...WHICH WILL KEEP WINDS OUT OF THE WEST-SOUTHWEST. HAVE GONE
WITH A SLOW DECREASING TREND FOR CLOUDS DURING THE DAY...SINCE
MODELS SEEM TO BE CLEARING CONDITIONS OUT TOO QUICKLY. HIGHS WILL BE
BETWEEN 10-20 DEGREES COLDER TOMORROW...ALTHOUGH THOSE VALUES WILL
BE NEAR CLIMATOLOGY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE WILL BE OVERHEAD TUESDAY NIGHT...BRINGING CALM AND
CLEAR CONDITIONS.
CLOUDS WILL BE ON THE INCREASE WEDNESDAY AS LOW PRESSURE DEVELOPS
OVER THE GULF COAST. 12Z GFS IS THE FAST OUTLIER WITH BRINGING IN
PRECIPITATION BY WEDNESDAY AFTERNOON...AND WILL STICK WITH MORE
CONSENSUS...SLOWER SOLUTIONS.
MODELS ARE IN GOOD AGREEMENT THAT MODEL PROFILES WILL BE NEAR
FREEZING MOST OF WEDNESDAY NIGHT...BUT THERE IS THE POTENTIAL FOR
SOME FREEZING PRECIPITATION OVERNIGHT. HOWEVER...NOT ENOUGH
CONFIDENCE TO GO WITH ANYTHING OTHER THAN RAIN/SNOW IN THE
FORECAST FOR NOW.
PRECIPITATION WILL SPREAD FROM SOUTH TO NORTH ON THURSDAY...AND
WILL GENERALLY GO WITH HIGH CHANCE POPS DURING THE DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
CONCURRING WITH HPC GUIDANCE, MADE FORECAST WITH MORE PREFERENCE TO
ECMWF MODEL OUTPUT. HENCE EXPECT MIXED PRECIPITATION THURSDAY NIGHT
TO BECOME SHOWERY FRIDAY AS TEXAS-BRED LOW PRESSURE SYSTEM PHASES
WITH PLAINS-BRED COLD FRONT IN THEIR EASTWARD PASSAGE THROUGH
THROUGH THE UPPER OHIO VALLEY THURSDAY NIGHT.
WITH THE UPPER-LEVEL JETSTREAM, DEVELOPING A COLD TROUGH OVER
CENTRAL CANADA THIS WEEKEND, THE NORTHERN JETSTREAM BRANCH WILL
PROMOTE ADDITIONAL PLAINS-BRED COLD FRONTS TO MOVE EASTWARD
THROUGH THE UPPER OHIO VALLEY SATURDAY AND MONDAY.
REGARDING TEMPERATURE DETAILS, PER RECENT HPC GUIDANCE AND NAEFS
MODEL OUTPUT, FORECASTED A COOL DOWN IN TEMPERATURES IN THE WAKE OF
THURSDAY NIGHT`S SYSTEMS, WITH VALUES PERHAPS AS COLD AS 5 TO 10
DEGREES COLDER THAN NORMAL IN THE WAKE OF SATURDAY`S COLD FRONTAL
PASSAGE. HENCE WHATEVER PRECIPITATION COMES SUNDAY INTO EARLY
MONDAY, IT WILL BE SHOWERS OF SNOW RATHER THAN RAIN.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
RECENT RADAR AND SURFACE DATA, COUPLED WITH HRRR MODEL OUTPUT,
SHOW TWO NARROW COLD FRONTAL BAND OF MVFR SHOWERS WILL CONTINUE TO
MOVE EASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH 00Z. SURFACE
WIND GUSTS CAN REACH 35-40 KTS. CONVECTION WILL BE GENERALLY TOO
SHALLOW FOR CLOUD TOPS TO REACH TEMPERATURES OF -20C. SO NO MORE
THUNDER FORECASTED.
ENSUING POSTFRONTAL COOL DOWN, BEST DEPICTED BY NAM MODEL
PROFILES, WILL PROMOTE A WELL-MIXED SURFACE LAYER TONIGHT, WHICH
WILL MAINTAIN MVFR STRATOCUMULUS AND SURFACE WIND GUSTS TO 25-30
KTS. A DEVELOPING CAPPING TEMPERATURE INVERSION NEAR 5 KFT AGL
SHOULD RESTRICT INSTABILITY SHOWER DEVELOPMENT. BY DAYTIME TUESDAY,
SURFACE WINDS SHOULD EASE TO 15-20 KTS AND STRATOCUMULUS CEILINGS
COULD LIFT TO VFR LEVELS BY AFTERNOON.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
VFR TUESDAY NIGHT AND WEDNESDAY. MIXED PRECIPITATION AND RESTRICTIONS
POSSIBLE THURSDAY AND FRIDAY, AS LOW PRESSURE MOVES NORTHEAST FROM
TEXAS. AN ADDITIONAL PERIOD OF RESTRICTIONS IS POSSIBLE WITH A COLD
FRONTAL BAND OF SHOWERS SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
339 PM EST MON JAN 23 2012
.SYNOPSIS...
AS A COLD FRONT MOVES THROUGH THE REGION TONIGHT...EXPECT ONE LAST
ROUND OF SHOWERS ALONG WITH GUSTY WINDS. CONDITIONS SHOULD THEN BE
GENERALLY DRY UNTIL WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TUESDAY/...
COLD FRONT WILL MOVE EAST DURING THE EVENING HOURS...WHICH AS OF MID
AFTERNOON IS ACROSS EASTERN OHIO. MANY LOCATIONS ARE EXPERIENCING
GUSTS UP TO 40-45 MPH IN SHOWERS AS THE COLD FRONT MOVES THROUGH.
CONSIDERING WIND GUSTS ARE ONLY IN CONVECTIVE SHOWERS...STRONG
WINDS WILL BE HANDLED BY SEVERE THUNDERSTORM WARNINGS AS
NECESSARY. ONCE THE FRONT PASSES...TEMPERATURES WILL FALL QUICKLY
TONIGHT...EVEN THOUGH CLOUD COVER WILL REMAIN ACROSS THE AREA.
WILL CONTINUE TO GO SLIGHTLY BELOW MODEL GUIDANCE FOR
TEMPERATURES...ALTHOUGH MANY LOCATIONS HAVE SEEN A RAPID DECREASE
IN SNOW COVER TODAY.
HIGH PRESSURE WILL BEGIN TO MOVE IN FROM THE SOUTHWEST ON
TUESDAY...WHICH WILL KEEP WINDS OUT OF THE WEST-SOUTHWEST. HAVE GONE
WITH A SLOW DECREASING TREND FOR CLOUDS DURING THE DAY...SINCE
MODELS SEEM TO BE CLEARING CONDITIONS OUT TOO QUICKLY. HIGHS WILL BE
BETWEEN 10-20 DEGREES COLDER TOMORROW...ALTHOUGH THOSE VALUES WILL
BE NEAR CLIMATOLOGY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE WILL BE OVERHEAD TUESDAY NIGHT...BRINGING CALM AND
CLEAR CONDITIONS. CLOUDS WILL BE ON THE INCREASE WEDNESDAY AS LOW
PRESSURE DEVELOPS OVER THE GULF COAST. 12Z GFS IS THE FAST OUTLIER
WITH BRINGING IN PRECIPITATION BY WEDNESDAY AFTERNOON...AND WILL
STICK WITH MORE CONSENSUS...SLOWER SOLUTIONS. MODELS ARE IN GOOD
AGREEMENT THAT MODEL PROFILES WILL BE NEAR FREEZING MOST OF
WEDNESDAY NIGHT...BUT THERE IS THE POTENTIAL FOR SOME FREEZING
PRECIPITATION OVERNIGHT. HOWEVER...NOT ENOUGH CONFIDENCE TO GO WITH
ANYTHING OTHER THAN RAIN/SNOW IN THE FORECAST FOR NOW. PRECIPITATION
WILL SPREAD FROM SOUTH TO NORTH ON THURSDAY...AND WILL GENERALLY GO
WITH HIGH CHANCE POPS DURING THE DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
CONCURRING WITH HPC GUIDANCE, MADE FORECAST WITH MORE PREFERENCE TO
ECMWF MODEL OUTPUT. HENCE EXPECT MIXED PRECIPITATION THURSDAY NIGHT
TO BECOME SHOWERY FRIDAY AS TEXAS-BRED LOW PRESSURE SYSTEM PHASES
WITH PLAINS-BRED COLD FRONT IN THEIR EASTWARD PASSAGE THROUGH
THROUGH THE UPPER OHIO VALLEY THURSDAY NIGHT.
WITH THE UPPER-LEVEL JETSTREAM, DEVELOPING A COLD TROUGH OVER
CENTRAL CANADA THIS WEEKEND, THE NORTHERN JETSTREAM BRANCH WILL
PROMOTE ADDITIONAL PLAINS-BRED COLD FRONTS TO MOVE EASTWARD
THROUGH THE UPPER OHIO VALLEY SATURDAY AND MONDAY.
REGARDING TEMPERATURE DETAILS, PER RECENT HPC GUIDANCE AND NAEFS
MODEL OUTPUT, FORECASTED A COOL DOWN IN TEMPERATURES IN THE WAKE OF
THURSDAY NIGHT`S SYSTEMS, WITH VALUES PERHAPS AS COLD AS 5 TO 10
DEGREES COLDER THAN NORMAL IN THE WAKE OF SATURDAY`S COLD FRONTAL
PASSAGE. HENCE WHATEVER PRECIPITATION COMES SUNDAY INTO EARLY
MONDAY, IT WILL BE SHOWERS OF SNOW RATHER THAN RAIN.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
RECENT SURFACE AND SATELLITE DATA SHOW STRATOCUMULUS HAS LIFTED TO
MVFR LEVELS ACROSS THE I-80 CORRIDOR, WHILE PREFRONTAL SCATTERED TO
BROKEN VFR STRATOCUMULUS HAVE SHIFTED EASTWARD FROM EASTERN OHIO
INTO WESTERN PENNSYLVANIA AND NORTHERN WEST VIRGINIA. DESPITE THE
SURFACE LAYER REMAINING RATHER STABLE, SURFACE WIND GUSTS CAN REACH
25-30 KTS.
RECENT RADAR AND SURFACE DATA, COUPLED WITH HRRR MODEL OUTPUT, SHOW
A NARROW COLD FRONTAL BAND OF MVFR SHOWERS WILL CONTINUE TO MOVE
EASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH 00Z. SURFACE WIND
GUSTS CAN REACH 35-40 KTS. CONVECTION WILL BE TOO SHALLOW FOR CLOUD
TOPS TO REACH TEMPERATURES OF -20C. SO NO THUNDER FORECASTED.
ENSUING POSTFRONTAL COOL DOWN, BEST DEPICTED BY NAM MODEL
PROFILES, WILL PROMOTE A WELL-MIXED SURFACE LAYER TONIGHT, WHICH
WILL MAINTAIN MVFR STRATOCUMULUS AND SURFACE WIND GUSTS TO 25-30
KTS. A DEVELOPING CAPPING TEMPERATURE INVERSION NEAR 5 KFT AGL
SHOULD RESTRICT INSTABILITY SHOWER DEVELOPMENT. BY DAYTIME TUESDAY,
SURFACE WINDS SHOULD EASE TO 15-20 KTS AND STRATOCUMULUS CEILINGS
COULD LIFT TO VFR LEVELS BY AFTERNOON.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
VFR TUESDAY NIGHT AND WEDNESDAY. MIXED PRECIPITATION AND RESTRICTIONS
POSSIBLE THURSDAY AND FRIDAY, AS LOW PRESSURE MOVES NORTHEAST FROM
TEXAS. AN ADDITIONAL PERIOD OF RESTRICTIONS IS POSSIBLE WITH A COLD
FRONTAL BAND OF SHOWERS SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
101 PM EST MON JAN 23 2012
.SYNOPSIS...
EASTBOUND COLD FRONT WILL BRING PERIODS OF RAIN SHOWERS AND GUSTY
WINDS THIS AFTERNOON.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF EARLY AFTERNOON...RAIN HAS MOVED EAST OF THE AREA...WITH A
SMALL AREA OF CLEARING BEHIND THE RAIN AND AHEAD OF ADVANCING COLD
FRONT CURRENTLY IN WESTERN OHIO.
A LINE OF SHALLOW CONVECTION IS DEVELOPING ALONG THE COLD FRONT.
THIS WILL BRING ANOTHER ROUND OF SHOWERS...THIS TIME BRINGING SOME
GUSTY WINDS. MANY OBSERVING SITES ARE GUSTING TO 30-40 MPH AS THE
FRONT MOVES THROUGH. WILL KEEP AN EYE ON THE LINE OF SHOWERS AS IT
APPROACHES THE AREA. THIS LINE SHOULD CLEAR THE AREA BY EARLY
EVENING. WARM AIR IS SURGING NORTH OF THE FRONT...ESPECIALLY WHERE
SKIES HAVE CLEARED.
OVERCAST CONDITIONS REMAIN ALONG I-80 WITH TEMPS CURRENTLY IN THE
MID 30S...BUT MORGANTOWN WAS 59 DEGREES AT NOON. WHEN THE COLD
FRONT COMES THROUGH...TEMPERATURES WILL BE NOTICEABLY COLDER.
AS WINDS BECOME WESTERLY BEHIND THE FRONT...SOME ISOLATED LAKE
ENHANCED SHOWERS WILL REMAIN NEAR INTERSTATE 80 AND ALONG THE
RIDGES. COLDER TEMPERATURES WILL ALLOW FOR RAIN TO CHANGE OVER TO
SNOW...WITH VERY LIGHT ACCUMULATIONS POSSIBLE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS LOW PRESSURE HEADS EAST TO NEW ENGLAND TUESDAY WEAK SURFACE
RIDGE WILL BUILD INTO REGION INTO WEDNESDAY WITH SEASONABLE
TEMPERATURES AND GENERAL DRY CONDITIONS. MODELS NOW IN MORE
AGREEMENT FOR A FASTER ARRIVAL OF DEEP MOISTURE AHEAD OF A
SHORTWAVE IN THE NORTHERN BRANCH AND A CLOSED LOW ACROSS TEXAS.
RAISED POPS AND WENT WITH A MIX OF RAIN AND SNOW FOR WEDNESDAY
NIGHT INTO THURSDAY. THIS SYSTEM COULD GET MESSY BUT AMOUNT OF
COLD AIR AVAILABLE IN DOUBT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE WILL MOVE TO THE EAST COAST THURSDAY NIGHT INTO FRIDAY
WITH CHANCE POPS FOR MIXED RAIN AND SNOW DIMINISHING DURING THE
DAY FRIDAY. ANOTHER FAST MOVING SYSTEM WILL ARRIVE SATURDAY FOR A
CHANCE OF SHOWERS WITH COLDER TEMPERATURES AND POSSIBLE SNOW
SHOWERS SUNDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
RECENT SURFACE AND SATELLITE DATA SHOW STRATUS LINGERING ACROSS
THE I-80 CORRIDOR, WHILE PREFRONTAL SCATTERED TO BROKEN VFR
STRATOCUMULUS HAVE SHIFTED EASTWARD FROM EASTERN OHIO INTO WESTERN
PENNSYLVANIA AND NORTHERN WEST VIRGINIA. DESPITE THE SURFACE LAYER
REMAINING RATHER STABLE, SURFACE WIND GUSTS CAN REACH 25-30 KTS.
RECENT RADAR AND SURFACE DATA, COUPLED WITH HRRR MODEL OUTPUT,
SHOW A NARROW COLD FRONTAL BAND OF MVFR SHOWERS WILL MOVE EASTWARD
THROUGH THE UPPER OHIO VALLEY 19Z-24Z. SURFACE WIND GUSTS CAN
REACH 35-40 KTS. CONVECTION WILL BE TOO SHALLOW FOR CLOUD TOPS TO
REACH TEMPERATURES OF -20C. SO NO THUNDER FORECASTED.
ENSUING POSTFRONTAL COOL DOWN, BEST DEPICTED BY NAM MODEL
PROFILES, WILL PROMOTE A WELL-MIXED SURFACE LAYER TONIGHT, WHICH
WILL MAINTAIN MVFR STRATOCUMULUS AND SURFACE WIND GUSTS TO 25-30
KTS. A DEVELOPING CAPPING TEMPERATURE INVERSION NEAR 5 KFT AGL
SHOULD RESTRICT INSTABILITY SHOWER DEVELOPMENT. BY DAYTIME TUESDAY,
SURFACE WINDS SHOULD EASE TO 15-20 KTS AND STRATOCUMULUS CEILINGS
COULD LIFT TO VFR LEVELS BY AFTERNOON.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
VFR TUESDAY NIGHT AND WEDNESDAY. MIXED PRECIPITATION AND RESTRICTIONS
POSSIBLE THURSDAY AND FRIDAY, AS LOW PRESSURE MOVES NORTHEAST FROM
TEXAS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
111 AM EST MON JAN 23 2012
UPDATED AVIATION DISCUSSION FOR 06Z TAFS
.UPDATE...
WV IMAGERY AND RUC ANALYSIS INDICATED A VIGOROUS SHRTWV MOVING INTO
WRN MO. TRENDS FROM THE 18Z MDLS AND 00Z NAM/RUC SUGGEST THAT THE
PROMINENT SHRTWV WILL SUPPORT A STRENGTHENING LOW A BIT FARTHER
SOUTH THAN PREVIOUS FCSTS. THE 00Z NAM HAS SHIFTED THE BULK OF THE
WAA/ISENTROPIC LIFT PCPN LATE TONIGHT INTO EARLY MON WELL TO THE
EAST COMPARED TO THE 18Z RUN WHILE THE 00Z RUC CONTINUES TO SUGGEST
THAT THE WAA SURGE WILL MOVE INTO CNTRL UPPER MI LATE TONIGHT BUT
WITH THE THERMAL GRADIENT ALSO SHIFTED A BIT TO THE EAST.
DIFFICULTIES HANDLING THE EXTENSIVE LINE OF CONVECTION MOVING INTO
ALSO LEADS TO GREATER UNCERTAINTY WITH THE MODELS SOLUTIONS.
SO...WITH CONFLICTING SIGNALS FROM MODEL OUTPUT...WILL NOT CHANGE
GOING HEADLINES AT THIS TIME. HOWEVER...HAVE TRIMMED ICE
ACCUMULATION AMOUNTS FOR LOCATIONS NEAR LAKE SUPERIOR AND LAKE
MICHIGAN WHERE TEMPS ARE EXPECTED TO CLIMB AOA FREEZING BY MORNING.
LARGER CHANGES MAY BE NEEDED WITH SNOW/ICE AMOUNTS LOCATION WHEN
ADDITIONAL INFORMATION IS AVAILABLE.
&&
.SHORT TERM TO 00Z TUE...
UPPER AIR PATTERN CONSISTS OF A 500 MB TROUGH OVER THE ROCKIES AND A
TROUGH OFF THE SE COAST. THERE IS ALSO A SHORTWAVE TROUGH OVER THE
NORTHERN PLAINS EMBEDDED IN THE ROCKIES TROUGH WITH A POTENT
SHORTWAVE OVER THE SOUTHERN ROCKIES. THIS POTENT SHORTWAVE EVEN HAS
SOME LIGHTNING WITH IT NEAR DENVER THIS MORNING. THE TWO SHORTWAVES
WILL AFFECT THE WEATHER AND BRING WINTRY PCPN WITH THEM.
NAM SHOWS THE SOUTHERN BRANCH SYSTEM FORMING A CLOSED 500 MB LOW AND
THIS LOW HEADS NORTHEAST AND COMBINES WITH THE NORTHERN BRANCH
SHORTWAVE IN THE NORTHERN PLAINS. NAM ALSO SHOWS SOME 850-500 MB
Q-VECTOR CONVERGENCE WITH DEEPER MOISTURE THROUGH MONDAY WITH
ISENTROPIC LIFT AND MOISTURE ON THE I280K-I295K SURFACES AS WELL.
GFS SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE THROUGH MONDAY AS
WELL. COMPARING MODELS...00Z ECMWF AT 18Z MONDAY IS THE FURTHEST NW
WITH THE UPPER LEVEL LOW WHILE THE GFS...NAM AND CANADIAN ARE MORE
TOWARDS NE WI FOR THE 500 MB LOW PLACEMENT.
TOUGH FORECAST FOR THIS PERIOD AS TO WHAT TYPES OF PCPN WILL
FALL...WHERE IT WILL FALL AND HOW MUCH. NAM CONTINUES TO SHOW THE
CUTOFF LINE FROM SNOW WEST OF A LINE FROM MARQUETTE TO IRON
MOUNTAIN. 12Z SOUNDINGS FROM KGRB AND KAPX SHOW DRY IN THE LOW TO
MID LEVELS AND THIS HAS PREVENTED PCPN FROM REACHING THE GROUND OVER
THE CWA TODAY. THE QUESTION IS HOW LONG THIS DRY AIR STICKS AROUND.
FOR ONE THING...THE DRY AIR SHOULD TAKE ANY ABOVE ZERO TEMPERATURES
ALOFT BACK BELOW ZERO WITH WET BULB COOLING AND KEEP THE PCPN AS
SNOW OR FREEZING DRIZZLE TODAY AND NOT SLEET.
NOT REAL CONFIDENT IN THIS FORECAST AS MODELS STILL HAVE A PROBLEM
WITH HOW MUCH WARM AIR IS COMING UP AND QPF TOTALS ARE DIFFERENT AS
WELL. WENT WITH A NAM ECMWF BLEND FOR THIS FORECAST WITH MORE
WEIGHTING ON THE MORE DETAILED NAM MODEL. NAM SHOWS THE 850 MB 0C
LINE STAYING AROUND THE IMT TO MQT AREA TONIGHT INTO EARLY MONDAY
AFTERNOON. TOP DOWN SOUNDING METHOD OF FORECASTING SHOWED PCPN
STAYING MOSTLY AS SNOW ACROSS THE FAR WESTERN CWA AND THEY COULD SEE
UP TO 7 INCHES OF SNOW ON MONDAY OUT BY ONTONAGON AND IRONWOOD AND
WENT WITH A WINTER STORM WARNING THERE FOR THE SNOW AMOUNTS. HEAVIER
PCPN DOES NOT ARRIVE UNTIL AFTER 06Z TONIGHT FOR THE CWA. THERE WILL
ALSO BE SOME FREEZING RAIN THAT COULD MIX IN WITH THE SNOW THERE AS
WELL. WENT WITH AN ICE STORM WARNING FOR MARQUETTE...DICKINSON AND
MENOMINEE COUNTIES AS THE 850 MB 0C LINE IS RIGHT ACROSS THIS AREA.
LOOKED LIKE PCPN WOULD BE A BIT OF SNOW...BUT MOSTLY FREEZING RAIN
FOR TONIGHT AND ALSO FOR MONDAY MORNING. TO THE EAST...FREEZING RAIN
IS A BIT LESS FOR AMOUNTS AND WENT WITH A FREEZING RAIN ADVISORY AS
TEMPERATURES WILL BE WARMER THERE AND WILL GET ABOVE FREEZING ON
MONDAY. TO THE WEST BETWEEN THE WARNINGS...WENT WITH A WINTER
WEATHER ADVISORY FOR MIXED PCPN. NOT ENOUGH SNOW ACCUMULATIONS OR
FREEZING RAIN FOR WARNINGS...SO WINTER WEATHER ADVISORY LOOKED GOOD.
HAD ALL THE HEADLINES START AT 06Z TONIGHT. COLD AIR COMES IN ON
MONDAY AFTERNOON AND SWITCHES THE PCPN OVER TO ALL SNOW MONDAY
AFTERNOON. DID NOT CHANGE MUCH FOR TEMPERATURES AS THEY DID NOT
REALLY WARM UP TODAY. ENDED UP LOWERING HIGH TEMPERATURES A BIT
TODAY AND HAVE THE LOW TEMPERATURES TONIGHT EARLY IN THE EVENING
WITH SLOWLY RISING TEMPERATURES TONIGHT INTO MONDAY MORNING WITH A
NON-DIURNAL CURVE. QPF FROM THIS EVENT LOOKS TO BE 0.40 TO 0.67 INCH
WITH FREEZING RAIN THE MAIN PCPN TYPE OVER THE CENTRAL CWA AND SNOW
IN THE WEST. IF THE WARMER AIR MOVES A BIT FURTHER WEST...THE
HEADLINES AND FREEZING RAIN AMOUNTS WILL NEED TO BE ADJUSTED
FURTHER. ICE STORM WARNINGS AND FREEZING RAIN ADVISORIES WERE ALSO
ISSUED BECAUSE PAVEMENT TEMPERATURES WILL STILL BE BELOW FREEZING
FOR A WHILE AND EVEN IF AIR TEMPERATURES GET ABOVE FREEZING...IT
WILL FREEZE ON THE PAVEMENTS WITH BELOW FREEZING TEMPERATURES ON THE
ROAD SURFACES WHICH WOULD JUSTIFY THE ICE STORM WARNING AND FREEZING
RAIN ADVISORIES.
.LONG TERM /MONDAY NIGHT THROUGH NEXT SUNDAY/...
MONDAY NIGHT AND TUESDAY...MESSY PRECIPITATION PRODUCING SYSTEM WILL
BE ON ITS WAY OUT OF THE CWA MONDAY EVENING. HIGH POPS ALL AREAS IN
THE EVENING AS DEFORMATION PRECIP COLLAPSES FM WEST TO EAST ACROSS
CWA. SOUNDINGS INDICATE FAR EAST CWA MAY STILL BE CONTENDING WITH
RAIN EARLY IN THE EVENING...BUT SWITCHED OVR TO SNOW ALL AREAS BY
LATE EVENING. ADDITIONAL SNOW AMOUNTS AFT 00Z TUESDAY ARE KIND OF
QUESTIONABLE. DEEP MOISTURE TO H7 REMAINS ENTRENCHED OVR THE AREA
BUT LARGER SCALE UVM IS LACKING. ONSHORE WINDS MAY ENHANCE SNOW OVR
FAR WEST AND WITH H85 TEMPS DROPPING BLO -10C THERE COULD ALSO BE
LAKE ENHANCEMENT. LAKE SNOW PARAMETER IS PRETTY MUCH MAX OUT OVR
MUCH OF THE WESTERN CWA...BUT THIS IS LIKELY DUE TO ALL THE MID
LEVEL MOISTURE STILL PRESENT. BEST CHANCE FOR DECENT SNOW AMOUNTS
WILL BE IN THE FAR WEST DUE TO TERRAIN AIDED LIFTING. BLSN/DRSN WILL
BECOME ISSUE ALONG SHORELINE OF LK SUPERIOR IN THE WEST THIRD OF CWA
MUCH OF THE NIGHT DUE TO DEVELOPING GUSTY NW WINDS OVR 30 MPH. KEPT
HIGHER POPS FOR LK EFFECT OVR NW FLOW AREAS EAST OF MARQUETTE ON
TUESDAY. DEEP MOISTURE DEPARTING AND LOWERING INVERSIONS/MARGINAL
INSTABILITY SHOULD KEEP SNOW ACCUMS LIMITED ON TUESDAY. THOUGH
COOLER THAN MONDAY IN MOST AREAS...MAX TEMPS ON TUESDAY WILL STILL
BE A BIT ABOVE NORMAL.
LK EFFECT GRADUALLY DIMINISHES/ENDS TUESDAY NIGHT OVR EASTERN CWA
WITH WARMING TEMPS AT H9 AND BACKING LOW-LEVEL WINDS. WEAK SFC
RIDGE POKES INTO WESTERN INTERIOR OVERNIGHT ALONG WITH PWAT MIN.
FAVORED LOWER END OF GUIDANCE FOR TEMPS WHICH RESULTED IN MINS ZERO
TO 5 ABOVE IN THE INTERIOR SW. MAY SEE SOME MID CLOUDS STREAMING IN
AHEAD OF NEXT SYSTEM BUT OTHERWISE WEDNESDAY SHOULD BE QUIET. TEMPS
IN SOME AREAS WILL REACH ABOVE FREEZING...THIS TIME WITHOUT THE
MESSY MIX OF RAIN AND SNOW.
IN THE EXTENDED...MEDIUM RANGE MODELS IN PRETTY GOOD AGREEMENT WITH
UPPER AIR/SFC PATTERN INTO NEXT WEEKEND. GIVEN FCST OF FAIRLY FAST
WEST TO EAST PACIFIC FLOW...THE AGREEMENT IN THE MODELS LENDS HIGHER
CONFIDENCE TO THE FORECAST. MAIN SYSTEMS TO AFFECT THE UPR LAKES
REGION ARE WEDNESDAY NIGHT INTO THURSDAY THEN AGAIN FRIDAY AND
FRIDAY NIGHT. BOTH SYSTEMS ARE LACKING MOISTURE AS HIGHER PWATS
REMAIN OVR CNTRL AND SOUTHERN STATES CLOSER TO MORE ACTIVE JET
STREAM. ONLY REAL CHANCE OF SNOW WILL BE LATER WEDNESDAY NIGHT INTO
THURSDAY OVER LK SUPERIOR AND PERHAPS INTO THE EASTERN CWA. COLD AIR
IS LACKING OVR THE UPR LAKES WITH TEMPS THURSDAY AND FRIDAY FCST TO
BE ABOVE NORMAL FOR DAYTIME HIGHS AND NIGHTTIME LOWS. LACK OF COLD
AIR LEADS TO MINIMAL LK EFFECT CONCERNS AS WELL. PUT SOME POPS FOR
NW FLOW LK EFFECT IN FOR NEXT WEEKEND THOUGH AS MODELS SHOW H85
TEMPS BLO -10C IN WAKE OF TROUGH PASSING THROUGH ON FRIDAY. IN A
NUTSHELL...NO REAL SIGNIFICANT WEATHER CONCERNS ARE EXPECTED FOR THE
NEXT WEEK BEYOND THE EVENT ENDING MONDAY NIGHT.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
LOW PRESSURE CURRENTLY CENTERED OVER NORTHEAST MISSOURI IS ALLOWING
MOISTURE TO FLOW INTO THE AREA PROVIDING FOR LOWER CEILINGS AS WELL
AS DECREASED VISIBILITIES AT ALL TAF SITES. SNOW SHOWERS SHOULD
BEGIN TO DEVELOP OVER CMX AND IWD BY 10Z THEREFORE HAVE INCLUDED
-SHSN IN THE TEMPO GROUP. SURFACE OBSERVATIONS UPSTREAM FROM THESE
SITES INDICATE CEILING AROUND 500FT MOVING INTO THE AREA BUT WOULD
NOT BE OUT OF THE QUESTION TO HAVE SOME LIFR CEILINGS. SURFACE OBS
ALSO INDICATE VIS IN THE IFR RANGE. HAVE KEPT A MIX OF -FZDZSN IN
THE FORECAST FOR SAW AS SOUNDINGS ARE STILL NEARLY ISOTHERMIC ALONG
THE 0 DEGREE ISOTHERM THROUGH AT LEAST 15Z. WILL HAVE TO MONITOR AS
SOME MODELS ARE HINTING THAT COLDER AIR MAY DOMINATE EARLIER
CHANGING THE PRECIP TO SNOW QUICKER THAN EXPECTED. CEILINGS NEAR
TERM FOR SAW WERE KEPT IN THE LIFR RANGE AS UPSTREAM OBS WERE AT
400-600FT AND WITH UPSLOPE FLOW FROM THE SSE VLIFR CEILINGS WOULD
NOT BE OUT OF THE QUESTION. VISIBILITIES SHOULD REMAIN IN THE IFR
RANGE.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
GALES WILL BE WINDING DOWN LATE THIS AFTERNOON OVER THE EAST HALF OF
LAKE SUPERIOR. THE PRESSURE GRADIENT WILL RELAX SOME TONIGHT INTO
MON MORNING AS THE PLAINS LOW MOVES NE TOWARD THE UPPER LAKES. AS
THE LOW MOVES ACROSS EASTERN LAKE SUPERIOR MON AFTN AND THEN INTO
ONTARIO MON NIGHT...IT APPEARS NORTHWESTERLY GALES WILL DEVELOP IN
ITS WAKE ACROSS CNTRL AND EASTERN PORTIONS OF THE LAKE. WINDS WILL
DIMINISH W TO E TUE AFTN/NIGHT WITH THE APPROACH OF A HIGH PRES
RIDGE. ALTHOUGH ANOTHER LOW PRES MAY IMPACT THE LAKE THU...NO
ADDITIONAL GALES APPEAR LIKELY ATTM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING
FOR MIZ001-003-004-010-084.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ007-
014-085.
WINTER STORM WARNING UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
MIZ002-009.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ006-
013.
ICE STORM WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR
MIZ005-011-012.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 9 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING FROM 7 PM THIS EVENING TO 9 AM EST TUESDAY FOR
LSZ243>250-264>266.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE... - NONE -
SHORT TERM...07
LONG TERM...JLA
AVIATION...KEC
MARINE...07
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
552 PM CST TUE JAN 24 2012
.UPDATE...
.AVIATION.../00Z TAF ISSUANCE/
A BIT OF A TRICKY FORECAST WITH THE IFR/MVFR CIGS IN...AND THE
VCNTY OF THE FORECAST AREA. SOME OF THE MVFR CIGS REMAIN TRAPPED
UNDER THE SURFACE HIGH PRESSURE RIDGE FROM NEAR KMSP INTO WEST
CENTRAL WI. EXPECT THESE CIGS TO REMAIN IN PLACE THROUGH MID
MORNING WEDNESDAY AS SURFACE WINDS TURN SOUTH. IFR CIGS LIKELY TO
OUR SOUTH. OTHERWISE...AN UPPER AIR TROUGH TO OUR WEST WILL MOVE
ACROSS THE AREA TONIGHT AND WEDNESDAY MORNING...AND THERE WILL BE
A MIX OF LOW END VFR AND MVFR CIGS ASSOCIATED WITH THIS FEATURE.
HAVE INDICATED IFR CIGS AT KRWF LATER TONIGHT THOUGH. THERE WILL
BE A CHANCE OF LIGHT SNOW OVER PORTIONS OF WEST CENTRAL INTO SOUTH
CENTRAL MN BUT THE BETTER CHANCE WILL BE TO THE SOUTH OF OUR TAF
SITES. HAVE INDICATED VCSH EXCEPT FOR A CHANCE OF 3SM AT KRWF.
WILL NEED TO WATCH THE TRENDS OVER SOUTHWEST MN LATER THIS
EVENING. EXPECTING VFR CONDITIONS TO DEVELOP AT LEAST WESTERN TAF
SITES LATE MORNING OR EARLY AFTERNOON AND THEN IN THE EVENING EAST
AS A WARM FRONT APPROACHES.
KMSP...AS MENTIONED ABOVE WILL KEEP MVFR CIGS IN PLACE THROUGH
WED MORNING...LIKELY BELOW 017. THE UPPER TROUGH TO OUR WEST MAY
BRING SOME LIGHT SNOW TO THE AREA. CURRENTLY EXPECTING ACTIVITY TO
BE SCT OR MAINLY TO THE SOUTH...BUT WILL HAVE TO WATCH TRENDS FOR
A POSSIBLE CHANGE TO VSBY RESTRICTIONS. EXPECTING AN IMPROVEMENT TO
VFR WED AFTERNOON.
&&
.DISCUSSION...
OVERALL THE LARGE SCALE PATTERN IS FAIRLY BENIGN WITH RESPECT TO
ITS IMPACT ON SENSIBLE WEATHER IN OUR AREA OVER THE UPCOMING WEEK.
WEST TO NORTHWEST UPPER FLOW WILL PREDOMINATE... BRINGING PERIODIC
MOISTURE DEFICIENT SHORTWAVES THROUGH OUR AREA WHICH WILL
GENERALLY AMPLIFY ONCE THEY GET EAST OF OUR LONGITUDE.
TEMPERATURES LOOK TO BE A BIT ABOVE NORMAL FOR THE MOST PART...
WITH THE COLDEST PERIOD AND PERHAPS SOME BELOW NORMAL READINGS IN
STORE FOR SATURDAY INTO MONDAY. LATEST SATELLITE IMAGERY AND RADAR
DATA SHOW CLOUDS STREAMING IN FROM THE WEST AT THE CURRENT TIME...
AHEAD OF A SHORTWAVE TROUGH WHICH CAN BE SEEN ON WATER VAPOR
MOVING INTO THE DAKOTAS. THERE HAVE BEEN A FEW OBSERVATIONS OF
LIGHT RAIN AND SNOW AHEAD OF THIS FEATURE... ALTHOUGH MUCH OF THE
ACTIVITY IS STILL ALOFT AT THE CURRENT TIME. GIVEN THE LACK OF
GOOD MOISTURE RETURN AHEAD OF THIS FEATURE... THE 12Z GUIDANCE
FROM THE GFS AND NAM ARE UNDERSTANDABLY UNDERWHELMING IN THEIR
PRODUCTION OF PCPN AS THIS SYSTEM MOVES THROUGH THE AREA TONIGHT
INTO WEDNESDAY MORNING... ALTHOUGH ALL MANAGE TO SQUEEZE OUT A
LITTLE BIT OF PCPN GIVEN THE COMBINATION OF SOME DECENT ISENTROPIC
LIFT AND DPVA AHEAD OF THE TROUGH. THE HIGH RESOLUTION
SOLUTIONS... INCLUDING THE HRRR... ALSO SUGGEST A PERIOD OF SOME
LIGHT PCPN TONIGHT INTO MONDAY MORNING... WITH A BETTER CO-LOCATION
OF SATURATION AND FORCING OVER THE SOUTHERN PART OF THE CWFA.
RAISED POPS SOME WITH THIS SYSTEM... BUT KEPT THEM IN THE CHANCE
RANGE SINCE ALTHOUGH IT SEEMS LIKELY THAT IT WILL PRECIPITATE IT
IS STILL QUESTIONABLE AS TO WHETHER OR NOT IT WILL MEASURE.
ANOTHER SMALL CONCERN AS THE SYSTEM MOVES THOUGH TONIGHT IS
WHETHER THE ELEVATED WARM NOSE... WHICH LOOKS LIKE IT WILL BE
AROUND 900-925MB... WILL BE SUFFICIENT TO CAUSE MELTING OF
HYDROMETEORS AS THEY DESCEND TO THE SURFACE. THE NAM IS THE MOST
BULLISH IN WARMING TEMPERATURES ALOFT... WHILE THE GFS AND RUC ARE
NOT AS STRONG WITH THE WARMING. THE UPSTREAM 12Z SOUNDING AT OMAHA
DEFINITELY SHOWED AN ABOVE FREEZING LAYER... SO THE QUESTION WILL
BE WHETHER IT IS ABLE TO COOL MUCH TOWARD THE WET BULB GIVEN THE
DRYNESS IN THE LAYER... OR IF MOISTURE ADVECTION OVERWHELMS THINGS
AND WE SIMPLY SEE THE WARM NOSE SATURATE WITH LITTLE CHANGE IN
TEMPERATURE. LOOKING AT THE UPSTREAM MIXING RATIOS IN THE
SOUTHWEST-NORTHEAST ORIENTED AXIS AHEAD OF THE TROUGH... FEEL
THERE SHOULD BE A TENDENCY TO MOISTEN IN THAT LAYER QUITE A BIT...
SO THINK THERE WILL BE POTENTIAL FOR AN ABOVE FREEZING WARM LAYER
FOR A TIME TONIGHT AS THE PCPN MOVES THROUGH... PARTICULARLY ALONG
AND SOUTH OF I-90. WITH THAT IN MIND... INCLUDING A MENTION OF
SOME IP ALONG WITH SN OVER THE SOUTHERN PART OF THE AREA FOR TONIGHT.
ONCE TONIGHT/S SYSTEM GETS OUT OF OUR HAIR... THINGS LOOK TO BE
FAIR AND DRY THROUGH THURSDAY... WITH THE NEXT CHANCE FOR ANY
MEANINGFUL PCPN HOLDING OFF UNTIL FRIDAY. WARM ADVECTION WILL
INCREASE ACROSS THE AREA TOMORROW AFTERNOON INTO TOMORROW
EVENING... WITH A FRONTAL SLIDING ACROSS THE STATE TOMORROW NIGHT.
THIS FRONT IS THE ONE POTENTIAL PCPN PRODUCER PRIOR TO FRIDAY...
BUT AT THIS TIME IT LOOKS LIKE WE WILL BE HARD PRESSED TO SEE
SUFFICIENT MOISTURE WORK INTO THE AREA PRIOR TO ITS PASSAGE TO
WRING OUT ANY PCPN. IT/S POSSIBLE THAT LATER FORECASTS WILL NEED
TO INCLUDE SOME FLURRIES OVER THE NORTHERN PART OF THE CWFA FOR
TOMORROW NIGHT... BUT FOR NOW THE MOST LIKELY SCENARIO STILL LOOKS
TO BE A DRY FROPA. A BRIEF COOL DOWN IS EXPECTED THURSDAY THROUGH
THURSDAY NIGHT AS HIGH PRESSURE DROPS SOUTHEAST INTO THE CENTRAL
PLAINS AND NORTHWEST FLOW BRINGS A QUICK SHOT OF SOME MODIFIED
ARCTIC AIR INTO THE REGION. A SHORTWAVE THEN LOOKS TO SWING
THROUGH THE AREA ON FRIDAY... WITH THE ECMWF AND GFS AND
REASONABLE AGREEMENT... ALTHOUGH THE ECMWF SOLUTION IS A BIT MORE
AMPLIFIED AND THEREFORE SLOWER AND ACCOMPANIED BY MORE IN THE WAY
OF PCPN. IN EITHER CASE... THERE LOOKS TO BE ENOUGH FORCING AND
DEEP LAYER SATURATION TO SUPPORT A MENTION OF POPS. UNFORTUNATELY
THE DIFFERENCES IN TIMING AND UNCERTAINTY REQUIRE BLANKETING A
LONGER PERIOD OF TIME WITH POPS THAN WHAT WILL EVENTUALLY OCCUR IN
REALITY... SO INCLUDED SOME CHANCE POPS FOR SNOW FROM FRIDAY INTO
SATURDAY FROM WEST TO EAST ACROSS THE AREA. LATER FORECASTS SHOULD
CERTAINLY BE ABLE TO NARROW AND FOCUS THIS TEMPORAL WINDOW ONCE
THINGS COME INTO BETTER AGREEMENT.
A DECENT SLUG OF COLD AIR LOOKS TO DROP INTO THE REGION AFTER
SATURDAY/S SYSTEM MOVES BY... BUT IT WILL BE SHORT-LIVED AS THE
GFS... ECMWF... AND THEIR RESPECTIVE ENSEMBLE ALL SUPPORT THE IDEA
OF A SUBSTANTIAL RIDGE BUILDING TO OUR WEST BY THE SUNDAY-MONDAY
TIME FRAME. RETURN FLOW WILL START TO BRING IN WARMER TEMPERATURES
ASSOCIATED WITH THIS RIDGE BY THE SUNDAY NIGHT INTO MONDAY TIME
FRAME... WITH SOME PCPN POSSIBLY DEVELOPING IN THE AREA OF
ISENTROPIC ASCENT DURING THAT TIME FRAME. A SOMEWHAT UNSETTLED
PATTERN THEN LOOKS TO PERSIST INTO TUESDAY AS THE NEXT SHORTWAVE
AND ASSOCIATED COLD FRONT WORK TOWARD THE AREA. ALL OF THIS WINDS
UP LEADING TO THE INCLUSION OF SOME CHANCE POPS FOR MUCH OF THE
PERIOD FROM SUNDAY NIGHT INTO TUESDAY... PARTICULARLY OVER THE
NORTHERN AND EASTERN PART OF THE CWFA WHERE BETTER SATURATION
ALONG THE SLOPED FRONTAL ZONE IS MORE LIKELY TO TAKE PLACE. IN
ADDITION... THINGS COULD CERTAINLY WARM ENOUGH BY MONDAY NIGHT OR
TUESDAY FOR SOME PTYPE ISSUES... SO INCLUDED SOME RN/SN MENTION BY
TUESDAY TO HIGHLIGHT THAT POSSIBILITY.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/JPR
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
614 AM CST MON JAN 23 2012
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
THE MAIN FORECAST CHALLENGE TODAY...IS TRYING TO DETERMINE HOW MUCH
SNOWFALL IS EXPECTED THROUGH THIS AFTERNOON. A CLOSED LOW
PRESSURE AREA OVER ERN IOWA WILL PIVOT NORTHEAST OVER THE WRN
GREAT LAKES AND ONTARIO CANADA TODAY. A COUPLE OF SEEDER- FEEDER
BANDS OF ENHANCED CLOUDS WERE OCCURRING OVER THE FORECAST AREA AS
PV ANOMALY LIFTS NORTHEASTWARD. EXPECT SNOW TO CONTINUE TO
INTENSIFY OVER WESTERN WISCONSIN AND EAST CENTRAL MN THIS
MORNING...BEFORE DIMINISHING THIS AFTERNOON. EXPECT A FEW MORE
TENTHS OF AN INCH OVER WESTERN MINNESOTA THIS MORNING WITH TOTAL
NEW SNOW AMOUNTS FROM ONE TO THREE INCHES FROM THE TWIN CITIES
EASTWARD. EVEN THOUGH ONE TO TWO INCHES OF SNOW IS ANTICIPATED BY
THE END OF THE MORNING COMMUTE...AFTER A LONG DURATION OF FREEZING
DRIZZLE...UNTREATED ROADS AND EXIT/ENTRANCE RAMPS WILL BE VERY
SLICK. WILL CONTINUE THE WINTER WEATHER ADVISORY THROUGH NOON MOST
AREAS...EXCEPT FOR A SMALL AREA OVER WEST CENTRAL WISCONSIN INTO
THE AFTERNOON TODAY. CLOUDS WILL GRADUALLY CLEAR OVER THE AREA
TONIGHT AS DRIER AIR BEGINS TO FILTER BEHIND THE EXITING LOW
PRESSURE SYSTEM.
UPPER RIDGE BUILDS OVER THE UPPER MIDWEST TONIGHT AND TUESDAY. BY
MID WEEK...THE UPPER AIRFLOW BECOMES MORE ZONAL ACROSS THE NORTHERN
TIER OF THE CONUS. ALTHOUGH...THERE COULD BE A FEW WEAK UPPER
LEVEL DISTURBANCE PASSING OVER THE FORECAST AREA. NO SIGNIFICANT
PRECIPITATION OR WEATHER IS EXPECTED OVER THE NEXT SEVERAL DAYS.
IT WILL TURN COLDER OVER THE WEEKEND AS AN UPPER LEVEL TROUGH CARVES
OUT OVER THE UPPER GREAT LAKES AND MIDWEST. THIS COLD AIRMASS WILL
BE SHORT LIVE AS IT SLIDES OVER TO THE EASTERN SEABOARD NEXT
WEEK.
&&
.AVIATION.../12Z TAF ISSUANCE/
FLIGHT CONDITIONS REMAIN RATHER UGLY THIS MORNING...THOUGH ALL
AREAS HAVE FINALLY CROSSED THE THRESHOLD FROM FZDZ TO SN. UPPER
LOW NOW OVER THE SE TIP OF MN AND IS HEADING FOR NRN WI. OUT
AHEAD OF THIS FEATURE...HAVE SEEN A STRONGER BAND OF SNOW DEVELOP
FROM SE MN INTO WRN WI. BACK WEST EXISTING DEFORMATION BAND THAT
HAS SLOWLY TRUDGED EAST OVERNIGHT NOW INTO TWIN CITIES METRO AND
MOVING THROUGH STC. FOR THE MOST PART CIGS ARE IFR...THOUGH THERE
ARE A COUPLE OF VFR POCKETS AROUND STC/RWF/RNH THAT WILL LEAD TO
SOME VARIABILITY IN CIGS THROUGH THE MORNING AT THESE LOCATIONS.
THESE HIGHER CIGS MAY ALSO GIVE MSP A BRIEF BREAK FROM SUB 017
CIGS THIS MORNING BEFORE THINGS FILL BACK IN. HRRR REFLECTIVITY
AND SREF PROBS FOR VIS LESS THAN 3SM BOTH HANDLING CURRENT SNOW
WELL...SO FOLLOWED TIMING FROM THOSE SOURCES TO MOVE SNOW EAST
ACROSS THE TERMINALS INTO THE AFTERNOON. THOUGH SNOW CURRENTLY
COMES TO AN END AROUND THE SODAK BORDER...EXTENSIVE CLOUD COVER
EXISTS ALL THE WAY OUT TO THE CENTRAL DAKOTAS. 925-850 RH FROM THE
GFS WAS HITTING THE CLOUD LOCATION WELL THIS MORNING...SO USED IT
TO TIME CLEARING THROUGH MN TERMINALS AT THE END OF THE TAFS. ONLY
CHANGE MADE TO GOING WIND FORECAST WAS TO BACK WINDS A BIT FASTER
THIS MORNING...STILL LOOKS GOOD FOR GUSTS OVER 20 KTS BY LATE
MORNING.
KMSP...CAN FINALLY SAY FZDZ IS DONE WITH CONFIDENCE...WITH ANY
PRECIP FROM NOW ON TO FALL AS SN. OBS TO THE WEST WITH BAND COMING
IN HAVE SHOWN THE LOW END OF THE OBSERVED VSBY AT 1SM...SO BROUGHT
TEMPO GROUP ONLY DOWN TO THERE. EXPECT SUB 1SM VSBYS TO REMAIN
EAST OF THE TERMINAL...CLOSER TO THE TRACK OF THE UPPER LOW. FOR
ENDING THE SNOW...EXPECT IFR CONDITION TO LAST THROUGH ABOUT
16Z...BUT MVFR SNOWS COULD LINGER OUT TO AS LATE AS 21Z. AREA OF
MIXED IFR TO VFR CIGS HAS BEEN SLOWLY DRIFTING SE TOWARD THE TWIN
CITIES OVERNIGHT...SO DO EXPECT SOME VARIABILITY WITH CIG HEIGHTS
IN THE SNOW...THOUGH CIGS BELOW 017 SHOULD DOMINATE. TREND THIS
WINTER FROM MODELS AND TAFS HAS BEEN TO BE TO AGGRESSIVE WITH
CLEARING CIGS OUT BEHIND SYSTEMS...SO KEPT RESTRICTED CIGS IN A
BIT LONGER THAN GUIDANCE WOULD SUGGEST.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR ANOKA-BENTON-
BLUE EARTH-BROWN-CARVER-CHISAGO-DAKOTA-FARIBAULT-FREEBORN-
GOODHUE-HENNEPIN-ISANTI-KANABEC-KANDIYOHI-LE SUEUR-MARTIN-
MCLEOD-MEEKER-MILLE LACS-MORRISON-NICOLLET-RAMSEY-REDWOOD-
RENVILLE-RICE-SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE-WASECA-
WASHINGTON-WATONWAN-WRIGHT.
WI...WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR BARRON-DUNN-
PEPIN-PIERCE-POLK-ST. CROIX.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR CHIPPEWA-
EAU CLAIRE-RUSK.
&&
$$
JVM/MPG
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1145 PM CST SUN JAN 22 2012
.DISCUSSION...
/316 PM CST SUN JAN 22 2012/
MAIN CONCERN CONTINUES TO BE THE POTENTIAL FOR SEVERE THUNDERSTORMS
OVER THE AREA THIS EVENING. MOST RECENT SURFACE ANALYSIS IS SHOWING
AN OCCLUDING SURFACE LOW OVER KANSAS WITH A WARM FRONT EXTENDING
FROM CENTRAL OKLAHOMA INTO THE MID SOUTH. TEMPERATURES AND DEWPOINTS
HAVE BEEN SLOWLY RISING OVER THE CWA TODAY AND WILL CONTINUE TO DO
SO INTO EARLY THIS EVENING AS THETA-E ADVECTION INCREASES FROM THE
SOUTH IN RESPONSE TO CENTRAL PLAINS UPPER TROUGH. STILL APPEARS
THAT SHOWERS AND THUNDERSTORMS MAY DEVELOP OVER SOUTHEAST MISSOURI
INTO SOUTHERN ILLINOIS BETWEEN 22-02Z IN AREA OF STRONG 925-850MB
MOISTURE ADVECTION. MAIN CHANCE FOR SEVERE THUNDERSTORMS WILL LIKELY
OCCUR THIS EVENING WHEN VERY STRONG/DEEP ASCENT CAUSED BY THE NEGATIVELY
TILTING MID LEVEL TROUGH WILL COINCIDE WITH MODEST INSTABILITY AND
VERY STRONG DEEP LAYER SHEAR. HRRR RUNS HAVE BEEN CONSISTENT TODAY
AND REASONABLY DEPICT A LINE OF STORMS DEVELOPING QUICKLY AROUND
02Z OVER SOUTHEASTERN MISSOURI THAT MOVES NORTHEASTWARD INTO THE
FAR EASTERN CWA BY 04Z. RUC SOUNDINGS DEPICT THAT THE LOW LEVEL
INVERSION WILL WEAKEN DURING THIS PERIOD WHICH SHOULD ALLOW FOR A
DAMAGING WIND THREAT WITH THE LINE. THERE IS ALSO SOME TORNADO
THREAT WITHIN THE LINE GIVEN 0-1KM BULK SHEAR VALUES BETWEEN
0-1KM.
PRECIPITATION WILL QUICKLY MOVE OUT OF THE AREA AFTER 06Z AS THE TROUGH/
SURFACE FRONT MOVES EAST OF THE AREA. LEFT THE CHANCE OF FLURRIES OVER
NORTHERN MISSOURI INTO WEST CENTRAL ILLINOIS LATE TONIGHT INTO LATE
MORNING MONDAY ON THE SOUTH SIDE OF THE DEEPENING UPPER LOW. THEN
EXPECT DRY WEATHER UNTIL EARLY WEDNESDAY. 12Z GFS BROUGHT STRONGER
ASCENT ALONG WITH SOME QPF UP TO I-70 DURING THE DAY WEDNESDAY.
THE 12Z NAM SUPPRESSED WITH PRECIPITATION TO THE SOUTH...MOST LIKELY
BECAUSE IT IS BRINGING A NORTHERN STREAM SHORTWAVE ACROSS THE
GREAT LAKES TOO QUICKLY. THE 18Z VERSION OF THE NAM AND THE 12Z
ECMWF FAVOR THE NORTHERN PLACEMENT. PRECIPITATION ON THE NORTHERN
FRINGE OF THIS SYSTEM WILL BE LIGHT AS THERE WILL BE STEADY DRY
AIR ADVECTING INTO IT. THIS WILL ALSO LIKELY ALLOW THE RAIN TO MIX
WITH OR CHANGEOVER TO SNOW AT TIMES AS THE WET BULB REMAINS NEAR
OR BELOW ZERO.
BRITT/KANOFSKY
&&
.AVIATION...
/1132 PM CST SUN JAN 22 2012/
COLD FRONT IS MOVING THROUGH WESTERN MISSOURI TOWARD OUR REGION.
CIGS BEHIND THE FRONT ARE BETWEEN 1000-2000FT AGL GENERALLY
SPEAKING...SO AM EXPECTING THESE CONDITIONS TO OVERSPREAD OUR
AREA. THINK LOWER IFR CIGS WILL CONTINUE TO STAY OVER NORTHEAST
MO/WEST CENTRAL IL AS THE WARM FRONT WILL LIKELY NEVER PASS
THROUGH THERE BEFORE THE COLD FRONT SWEEPS THROUGH. WIND WILL
INCREASE FROM THE WEST TO 20-30KTS. EXPECT LOW MVFR CIGS TO HANG
AROUND THROUGH THE MORNING WITH CIGS RISING AND SCATTERING DURING
THE AFTERNOON. WINDS WILL REMAIN STRONG AND GUSTY BUT SHOULD
DIMINISH BY SUNSET.
SPECIFICS FOR KSTL...
VFR CIGS WILL DROP BACK TO BETWEEN 1000-2000FT AS THE COLD FRONT
APPROACHES AROUND 10Z. WIND WILL INCREASE FROM THE WEST TO
20-30KTS BEHIND THE FRONT AND LOW-END MVFR CIGS WILL PREVAIL
THROUGH THE MORNING. SHOULD SEE CIGS LIFT ABOVE 2000FT DURING THE
EARLY AFTERNOON AND SCATTER BY SUNSET WITH DIMINISHING WINDS.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1131 PM CST Sun Jan 22 2012
...UPDATED AVIATION DISCUSSION...
.UPDATE...
/651 PM CST Sun Jan 22 2012/
A localized area of strong low-level convergence is developing close
to the surface low which is tracking across the southern KC metro at
this time. Increasing winds around 2000 ft AGL are bringing in a
surge of low-level theta-e advection, enough to bring MUCAPE values
to between 500 and 900 J/kg per latest RUC analysis. 00Z TOP sounding
shows WBZ height of only 6000 ft so small hail will be easily
attainable in the stronger cells this evening. Have already received
numerous reports of pea-size hail across southern portions of the KC
metro, with hail as large as nickel size reported in Johnson Co KS.
While hail should generally remain below severe limits, low-level
helicity values are just high enough to allow for a few rotating
updrafts in the stronger cells. Will keep a close eye on any cell
that can attain any degree of mid-level rotation as this could
enhance updraft strength enough to get hail stones approaching
quarter size.
Hawblitzel
.DISCUSSION...
Short range (Tonight through Tuesday night)...
The main focus for this time frame deals with the tonight period as
a powerful storm system moves across the region.
Per latest water vapor satellite imagery a strong PV anomaly was
digging into the Red River area of Oklahoma and Texas. A deep
surface low was positioned on the northern tip of this anomaly
through Kansas with an inverted surface trough nosing up the
Missouri River Valley through Iowa and Nebraska. Very warm
temperatures aloft allowed temperatures, despite limited mixing
depth, to climb into the upper 50s and perhaps low 60s across
southern and western portions of the forecast area. 12Z UA analysis
showed cold air poised just to our north ready to spill into the
area as the system shifts east this evening and tonight. The system
itself appears to be digging deeper than previously thought and with
that in mind the chances for precipitation should shift south as
well. Have therefore increased POPs quite a bit across the northern
half of the forecast area and continued to taper them to slight
chance pops across our south. As the cold air spills into the region
rain/rain showers will transition into snow from northwest to east
throughout the evening. This system should be fast moving and it
looks like by the time the deepest cold air will reach most of the
forecast area, the low will have lifted away and we end up with
relatively light, wrap around precipitation. So with the far
northwest portions of the forecast area transitioning earliest, the
snow amounts in that area are expected to the highest, which is
still expected to be around an inch or less. The limited duration
of the event elsewhere will limit accumulations to just a few tenths
of inch to around half an inch and this should mainly be confined to
northern Missouri, generally along and north of highway 36.
Once this system sweeps north and east of the forecast area quiet
weather should prevail through Tuesday. There is no real surge of
cold air at the surface in the wake of this system so for areas that
did not receive any snow temperatures should climb back to above
normal values with readings in the low to mid 40s. Temperatures may
struggle a bit in northern Missouri due to possible snow cover and
longer presence of cloud cover limiting daytime heating.
Another system will move into the Southern Plains Tuesday night and
warm advection ahead of the system may bring small chances for
rain/showers into southern sections of the forecast area. The best
chances will remain to our south and could see future updates remove
the already low POPs entirely.
CDB
Medium range (Wednesday through Sunday)...
Operational and ensemble models continue to agree on the overall
synoptic regime through the medium range with a negative height
anomaly over the middle Rio Grande valley becoming temporarily
separated from the main northerly jet; then opening up to help form
a mean longwave trough over the eastern conus as the Hudson Bay
vortex depresses equatorward and higher amplitude ridging develops
over the northeast Pacific basin. However, several important details
regarding the depth, location, and speed at which this cutoff
feature ejects eastward lead to larger uncertainty through the
period. In general, the medium range will likely be categorized by
above average temperatures into the weekend, followed by a cooling
trend to near average temperatures (then quite possible a period of
below average at an just beyond this time frame given the
hemispheric pattern).
Recent ECMWF solutions have lacked dependable continuity and have
generally been deeper and more connected to northern stream flow
with regards to the southern cut off system. However, the 12Z EC
iteration has trended significantly towards the GFS, though remains
deeper than other models and thrusts more moisture north and
displaces the sfc high pressure over the lower Missouri River
valley. GEFS members are primarily towards the slower and more
cutoff end of the spectrum keeping the system trapped into SW Texas
longer; thus have hedged closer to the operational GFS which appears
to be a good compromise. With this thinking, have kept the forecast
area dry with moisture limited to the I-44 corridor. Forecast
thicknesses and H9-H8 temperatures would suggest high temps above
average through Friday, though selectively toned back some of the
forecast given uncertainty in cloud cover, insolation, and mixing
depth. Cooler sfc high pressure will dive southeast from western
Canada through the weekend, with the bulk of the coldest air focused
into the Great Lakes. Consensus output yielded temperatures near or
slightly above average for the end of the period, yet pattern
recognition would suggest this is too warm. However, given the
inherent uncertainty for the end of the medium range, could not
justify making major revisions as of yet.
21
&&
.AVIATION...
For the 06Z TAFs...Band of light rain/snow is showing steady
weakening as it approaches northwest Missouri. Southern edge of this
band will track very close to MCI over the next 2 hours. For now
expect precip to narrowly miss MCI so that the TAF was kept dry, but
will keep a close eye on radar trends. Any precipitation that does
impact MCI or STJ will be very light and impacts should be minimal.
Lingering stratocumulus will provide periods of MVFR cigs through the
remainder of the early morning before ceilings lift and scatter
through early afternoon. Northwesterly gusts may exceed 25 kts
overnight before steadily weakening through the day.
Hawblitzel
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1130 PM CST SUN JAN 22 2012
.UPDATE...
WILL LET ADVISORY REMAIN IN EFFECT. BEST LIFT HAD SHIFTED OVER
INTO WESTERN IOWA AND EXTREME EASTERN NEBRASKA AS OF 1130 PM.
RADAR STILL SHOWED SOME AREAS OF LIGHT SNOW SHOWERS OFF TO OUR
WEST THAT WILL MOVE THROUGH DURING THE EARLY MORNING. MOST OF
THE MEASUREABLE PRECIPITATION SHOULD END BY AROUND 3 OR 4 AM.
00Z MODELS SHOWED LOW LEVEL MOISTURE BELOW 3000 FEET AGL SHOULD
LINGER UNTIL LATE MONDAY MORNING OR EARLY MONDAY AFTERNOON.
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
GENERALLY EXPECTED MVFR CEILINGS TO CONTINUE INTO MONDAY MORNING
WITH VISIBILITIES INCREASING AS THE NIGHT GOES ON AT BOTH KOFK
AND KOMA. STILL MAY HAVE SOME AREAS IFR VISIBILITIES AND CEILINGS
PRIOR TO SUNRISE...BUT STRONGEST RADAR RETURNS HAVE SHIFTED EAST.
FOR KLNK...SOME DRIER LOW LEVEL AIR HAS WORKED IN...WITH VFR
CEILINGS. THINK THERE COULD BE SOME TEMPORARY MVFR CONDITIONS AT
KLNK OVERNIGHT.
AS HIGH PRESSURE BUILDS IN FROM THE WEST MONDAY...EXPECT NORTHWEST
WINDS TO DECREASE.
MILLER
&&
PREV DISCUSSION... /ISSUED 310 PM CST SUN JAN 22 2012/
SHORT TERM...TONIGHT THROUGH WEDNESDAY.
MAIN FORECAST CHALLENGE AND CONCERN CENTERS AROUND SNOW AND
BLOWING SNOW OVERNIGHT.
STRONG MID/UPPER LEVEL TROF AXIS NOW EXTENDS ACROSS THE CENTRAL
PLAINS WITH A WEAKER SECONDARY SHORTWAVE AXIS EXTENDING ACROSS
ERN MT INTO ERN WY. AT THE SFC...LOW PRESSURE IS QUICKLY MOVING
EAST ACROSS CENTRAL KANSAS WITH AN INVERTED TROF/CDFNT EXTENDING
UP THE MISSOURI RIVER VALLEY AT 21Z. REGIONAL MOSIAC RADAR LOOP
SHOWS A WIDENING NARROW MID LEVEL FRONTOGENETICAL BAND OF LIGHT TO
MODERATE PCPN OCCURING JUST BEHIND THE BOUNDARY WITH
LIGHTER/WIDESPREAD SNOWFALL OCCURING IN BROADSCALE VERTICAL MOTION
ASSOCIATED DEFORMATION ZONE BEHIND THE FRONTOGENETIC BAND. THE DRY
SLOT OVER PORTIONS OF SOUTHEAST NEB AS EVIDENT ON SATELLITE
IMAGERY CONTINUES TO SLOWLY FILL IN THIS AFTERNOON. TEMPERATURES
AHEAD OF THE BOUNDARY HAVE JUMPED INTO THE MID TO UPPER 40S WITH
LOWER TO MID 50S IN EXTREME SOUTHEAST NEBRASKA. COLD POCKET AT
850MB IS DIRECTLY TO OUR NORTH ACROSS ERN SD PER UPPER AIR
ANALYSIS AND RUC GUIDANCE. THIS COLD POCKET WILL CONTINUE TO DRIFT
SOUTH INTO THE FORECAST AREA THROUGH EARLY EVENING...AIDING IN
QUICKLY DROPPING SFC TEMPS BELOW FREEZING BEHIND THE BOUNDARY.
PCPN WILL CONTINUE TO INCREASE FROM WEST TO EAST ACROSS THE CWA AS
THE MID/UPPER LEVEL TROF CONTINUES TO DRIFT EWD AND
BECOMES NEGATIVELY TILTED AS IT MOVES TOWARD THE MISSISSIPPI VALLEY.
FIRST PUSH IS ALREADY APPROACHING OUR FAR NWRN COUNTIES IN WELL
DEFINED MID LEVEL FRONTOGENETIC BAND EXTENDING FROM NERN NEB INTO
WRN KS. PCPN TYPE WITH THIS WILL BE TRICKY BUT AS WE LOOSE DAYLIGHT
AND ABOVE MENTIONED COLD PUSH FROM ERN SD ADVECTS DOWN...WE SHOULD
BEGIN TO TURN ANY LIQUID PCPN OVER TO SNOW RATHER QUICKLY AS WE
PROGRESS THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS. SECOND
PUSH OF LIGHT SNOW WILL COME WITH THE MORE BROADSCALE LIFT BEHIND
THE TROF IN DEFORMATION AREA. LINGERING PCPN WILL LIKELY OCCUR
AHEAD OF THE SECONDARY NRN HIGH PLAINS SHORTWAVE THROUGH THE EARLY
MONDAY MORNING HOURS.
QPF AMOUNTS ARE GENERALLY LESS THAN 0.20" IN THE NORTH AT
MOST...WITH LESS THAN 0.10" IN OUR SOUTH. GOING FORECAST HAS A
GOOD HANDLE ON SNOWFALL AMOUNTS AND CONTINUE TO THINK THAT A 1-2"
SWATH ACROSS THE NORTHERN COUNTIES WITH ABOUT 0.5" TOWARD THE I-80
CORRIDOR.
NORTHWEST WINDS WILL PICK UP BEHIND THE BOUNDARY AFTER SUNSET WITH
GUSTS NEAR 40 MPH LIKELY INTO THE OVERNIGHT. IN THE NORTH...THIS
WILL CREATE AREAS OF BLOWING SNOW AND SO GOING WINTER WEATHER
ADVISORY FOR SNOW AND BLOWING SNOW THRU 12Z STILL LOOKS GOOD. HAVE
EXPANDED THE ADVISORY SLIGHTLY SOUTH AND EAST. WITH NEAR OR LESS
THAN AN INCH OF SNOW TO THE SOUTH OF THE ADVISORY AREA...WILL HOLD
OFF ON ANY ADVISORY BUT ROADS MAY STILL BECOME SLICK WITH JUST
MINOR SNOWFALL ACCUMULATIONS.
THE SYSTEM MOVES EAST OF THE AREA ON MONDAY AND FORECAST AREA
LOOKS DRY AS WEAK UPPER RIDGING MOVES OVERHEAD. PATTERN EVOLVES
INTO A SPLIT FLOW REGIME BY TUESDAY NIGHT WITH SOUTHERN CLOSED
LOW MOVING ACROSS TEXAS AND A WEAK SHORTWAVE AXIS CROSSING THE
FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY. HAVE REMOVED POPS
TUESDAY NIGHT AS SOUTHERN STREAM SYSTEM APPEARS TO BE FAR REMOVED
FROM THE FORECAST AREA TO INDUCE ANY PCPN.
KERN
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY.
PATTERN IN THE EXTENDED PERIOD BEGINS MILD AND APPEARS IT
WILL BECOME MORE NORTHWESTERLY AND COOLER TOWARD NEXT
WEEKEND...ALTHOUGH SOME QUESTION ON WHETHER IT WILL BEGIN TO
MODERATE BY DAY 7. FORECAST GENERALLY LOOKS DRY...ALTHOUGH A SMALL
PRECIP CHANCE WILL BE CARRIED IN FRIDAY PERIOD NERN ZONES. VERY
GOOD AGREEMENT EXISTED BETWEEN 12Z GFS/CMC AND 12Z/00Z ECMWF WITH A
SHORTWAVE THROUGH DRIVING A COLD FRONT ACROSS FORECAST AREA
EARLY FRIDAY. EVEN 00Z GFS ENSEMBLE MEAN WAS IN ACCORDANCE. SEVERAL
DIFFERENCES EXISTED...HOWEVER...IN EXACTLY HOW WARM WILL THURSDAY
BE...WITH CANADIAN EXCEPTIONALLY MILD...CLOSE TO +10 DEG C AT H85.
MEANWHILE 00Z ECMWF HAD FLIPPED TO A LITTLE BELOW ZERO FROM WARMER
SOLUTION YESTERDAY AND THEN BACK TO A WARMER ONE THIS MORNING. GFS
APPEARED TO BE A DECENT COMPROMISE AND COULD YIELD READINGS PER
PREVIOUS FORECAST AND LITTLE CHANGES WERE MADE. MILD TEMPERATURES
ALOFT AHEAD OF FRONT FRIDAY COULD MIX DOWN JUST AHEAD OF OR WITH
FROPA. SO ALTHOUGH MAX TEMPS WILL PROBABLY BE COOLER THAN
THURSDAY...GENERALLY LEFT HIGHS MOSTLY ABOVE 12Z MEX NUMBERS.
COOLING TREND WAS CONTINUED INTO SATURDAY AND TO SOME DEGREE INTO
SUNDAY EVEN THOUGH LATEST GFS/ECMWF SUGGESTED MODERATION BY DAY 7.
WITH UPPER FLOW STARTING NEXT WEEKEND NORTHWESTERLY...DIDN/T WANT TO
BE OVERLY OPTIMISTIC JUST YET WAITING FOR A MODERATING WAVE TO SHIFT
FLOW TO MORE WESTERLY.
CHERMOK
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR NEZ011-012-
015>018-030>034-042-043.
IA...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR IAZ043.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
422 PM EST MON JAN 23 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS WESTERN NEW YORK TONIGHT BRINGING
SHOWERS ALONG WITH STRONG GUSTY WINDS. LAKE EFFECT EFFECT SHOWERS
DEVELOPING IN THE WAKE OF THE FRONT ON TUESDAY WILL BRING LIGHT SNOW
ACCUMULATIONS TO THE NORTH COUNTRY WITH LITTLE OR NO ACCUMULATION
EAST OF LAKE ERIE. HIGH PRESSURE WILL BRING A BRIEF RETURN TO QUIET
WEATHER ON WEDNESDAY BEFORE THE NEXT SYSTEM BRINGS ANOTHER CHANCE OF
PRECIPITATION THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
THE PRIMARY WEATHER MAKER FOR WESTERN NEW YORK WILL BE A MATURE LOW
PRESSURE SYSTEM CURRENTLY CENTERED OVER THE EASTERN END OF
MICHIGAN/S UPPER PENINSULA. THE LOW WILL LIFT INTO WESTERN QUEBEC
TONIGHT AS WHILE COLD AIR WRAPPING INTO THE LOW WILL SWEEP A STRONG
COLD FRONT ACROSS WESTERN NEW YORK MAKING STRONG WINDS AND FALLING
TEMPERATURES THE MAIN FORECAST CONCERNS FOR TONIGHT.
AS THE AFOREMENTIONED COLD FRONT MOVES ACROSS THE REGION
TONIGHT...EXPECT STRONGER WINDS ALOFT TO MIX DOWN TO THE SURFACE
CREATING GUSTY WINDS TONIGHT ACROSS WESTERN NEW YORK. LATEST MODEL
GUIDANCE SUGGESTS THAT THE CORE OF THE SOUTHWESTERLY LOW LEVEL JET
WILL STAY ACROSS AND TO THE WEST OF THE NIAGARA
FRONTIER...SUGGESTING THAT ADVISORY LEVEL WINDS WITH GUSTS TO AROUND
50 MPH WILL BE LIMITED TO THE WESTERNMOST COUNTIES IN NEW YORK. THE
JET LIFTS NORTH ACROSS LAKE ONTARIO OVERNIGHT SPARING THE NORTH
COUNTRY FROM THE STRONGEST WINDS. EXPECT TEMPERATURES TO DROP
MARKEDLY BEHIND THE FRONT WITH LOWS BOTTOMING OUT IN THE UPPER 20S
TO NEAR 30 ACROSS FAR WESTERN NEW YORK AND THE SOUTHERN TIER. THE
COLD AIR WILL TAKE A LITTLE LONGER TO REACH AREAS EAST OF LAKE
ONTARIO WHERE TEMPERATURES SHOULD REMAIN JUST ABOVE FREEZING.
REGARDING THE PRECIPITATION FORECAST FOR TONIGHT...CURRENT RADAR OBS
INDICATE ANOTHER BAND OF SHOWERS WITH ISOLATED THUNDER OVER
WESTERN OHIO ASSOCIATED WITH FRONTAL FORCING ALONG THE COLD
FRONTAL BOUNDARY WITH ADDITIONAL ENHANCEMENT FROM INCREASED
INSOLATION/DIABATIC HEATING DUE TO A DRY SLOT MOVING ACROSS THAT
REGION. HRRR MODEL CURRENTLY HAS A GOOD HANDLE ON THE SHOWER
ACTIVITY...BRINGING IT INTO THE NIAGARA FRONTIER BY EARLY EVENING
AND QUICKLY FALLING APART BY THE TIME IT REACHES THE GENESEE
VALLEY AS INSTABILITY AND SYNOPTIC FORCING WEAKENS. WILL CARRY
LIKELY TO CATEGORICAL POPS FOR THE WESTERN COUNTIES WITH A SLIGHT
CHANCE OF THUNDER THIS EVENING TRANSITIONING TO CHANCE POPS FOR
THE EASTERN HALF OF THE FORECAST AREA.
COLD AIR FILTERING IN BEHIND THE COLD FRONT NECESSITATES A
DISCUSSION OF LAKE EFFECT POTENTIAL ON TUESDAY. WHILE 850MB TEMPS
GET NOMINALLY COLD ENOUGH FOR LAKE EFFECT...AROUND -10C TO -12C
ACROSS LAKE ERIE WITH A FAVORABLE WEST-SOUTHWEST WIND AND LOW
SHEAR...THE PRESENCE OF SUBSTANTIAL DRY AIR IN THE DENDRITIC GROWTH
ZONE AND AN INVERSION LEVEL RUNNING AT 5KFT OR LOWER IS NOT
IMPRESSIVE. THE REGIONAL GEM MODEL KEEPS THE DEEPER MOISTURE A
LITTLE FARTHER SOUTH...RESULTING IN A SLIGHTLY MORE FAVORABLE
PROFILE FOR SNOW. GIVEN THIS UNCERTAINTY...WILL KEEP POPS LIMITED TO
CHANCE EAST OF LAKE ERIE AND KEEP WEATHER LIMITED TO FLURRIES. EAST
OF LAKE ONTARIO...LONGER FETCH OFF OF THE LAKE AND SLIGHTLY COLDER
AIR IN THE LOWER LEVELS MAY RAISE THE INVERSION JUST ENOUGH TO
GENERATE SOME LIGHT SNOW SHOWERS...MAINLY ACROSS JEFFERSON AND LEWIS
COUNTIES...THOUGH ACCUMULATIONS WILL GENERALLY RUN IN THE
NEIGHBORHOOD OF 1-3 INCHES AT BEST.
PLENTY OF COLD AIR AND LAKE INDUCED CLOUD COVER IN PLACE WILL MAKE
FOR A TYPICAL DAY...FOR LATE JANUARY...WITH HIGHS RANGING FROM THE
UPPER 20S TO LOWER 30S ACROSS THE FORECAST AREA.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
A PROGRESSIVE PATTERN WILL BE IN PLACE ACROSS NORTH AMERICA DURING
THIS PERIOD AS THE BROAD POLAR VORTEX THAT HAS BEEN IN PLACE OVER
CANADA WILL RETROGRADE TO ALASKA. THIS WILL KEEP A STRONG ZONAL JET
OVER THE GULF OF ALASKA AND PACIFIC NORTHWEST...WHICH WILL RESULT IN
A CONTINUAL FEED OF PACIFIC MODIFIED AIR OVER THE LOWER 48. OUR
TEMPERATURES WILL AVERAGE ABOVE NORMAL AS A RESULT...WITH LITTLE IN
THE WAY OF SIGNIFICANT WEATHER. THE DETAILS...
A SECONDARY COLD FRONT WILL DROP ACROSS THE LOWER GREAT LAKES ON
TUESDAY NIGHT...AND WHILE A VERY SHORT LIVED POCKET OF -10C H85 AIR
WILL SUPPORT SOME LAKE EFFECT EAST OF LK ONTARIO...SNOWFALL AMOUNTS
WILL NOT BE SIGNIFICANT. LAKE INDUCED CONVECTION EARLY ON SHOULD
DISINTEGRATE AS PACIFIC BASED AIR MOVES IN AND PUMPS H85`S TO -4C.
OTHERWISE...ANY NUISANCE SNOW SHOWERS ASSOCIATED WITH THE FRONTAL
PASSAGE WILL QUICKLY GIVE WAY TO CLEARING SKIES AS HIGH PRESSURE
WILL BUILD ACROSS ALL OF THE GREAT LAKES REGION.
WEDNESDAY SHOULD BE A FAIRLY NICE DAY ACROSS THE REGION AS A LARGE
AREA OF HIGH PRESSURE WILL DRIFT ACROSS PENNSYLVANIA. WILL BUMP MAX
TEMPS UP A BIT FROM CONTINUITY...AS H85`S ARE EXPECTED TO MODERATE
TO AROUND ZERO/-2C. THIS SHOULD SUPPORT AFTERNOON READINGS IN THE
MID 30S ACROSS THE LOWER ELEVATIONS...WHILE THE NORTH COUNTRY WILL
EXPERIENCE HIGHS CLOSER TO THE SEASONAL NORM IN THE UPPER 20S.
A WEAKLY DIVERGENT FLOW WILL ACCOMPANY A JET STREAK ACROSS THE LOWER
GREAT LAKES ON WEDNESDAY NIGHT...AND THIS WILL LIKELY LEAD TO AN
INCREASE IN CLOUD COVER. GIVEN THE DEARTH OF MOISTURE AND OVERALL
SYNOPTIC LIFT...WILL ONLY CARRY SLGT CHC POPS.
A POTENT SHORTWAVE WILL THEN DIG ACROSS THE UPPER MISSISSIPPI VALLEY
ON THURSDAY...AND THIS WILL HELP TO AMPLIFY AN ALREADY BULGING
SHORTWAVE RIDGE OVER OUR FORECAST AREA. WHILE THIS WILL PROMOTE FAIR
WEATHER ACROSS OUR REGION FOR THE BULK OF THE DAY...WE WILL
EXPERIENCE AN INCREASE IN CLOUD COVER AS LOW LEVEL MOISTURE WILL
POOL IN ADVANCE OF THE NEXT FRONTAL SYSTEM. THERE COULD EVEN BE A
COUPLE LIGHT RAIN SHOWERS IN THE AFTERNOON OVER THE FAR WESTERN
COUNTIES.
FOR THURSDAY NIGHT...OUR REGION WILL FIND ITSELF STRADDLED BY A PAIR
OF STORM SYSTEMS. THE AFOREMENTIONED UPPER MISSISSIPPI VALLEY SHORT
WAVE WILL TRACK ACROSS SOUTHERN ONTARIO WHILE A SFC LOW GENERATED IN
THE SOUTHERN BRANCH IS EXPECTED TO MAKE ITS WAY ACROSS THE
APPALACHIANS TO VIRGINIA. A PACIFIC BASED COLD FRONT STRETCHING
BETWEEN THE TWO WILL CROSS OUR FORECAST AREA DURING THE COURSE OF
THE NIGHT. SINCE FORCING BETWEEN THE TWO SYSTEMS SHOULD NOT BE VERY
STRONG...LIGHT LOW QPF SHOWERY PCPN COULD PROVE TO BE PROBLEMATIC AS
A WINTRY MIX WILL BE POSSIBLE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
WHILE TEMPERATURES WILL AVERAGE ABOVE NORMAL FOR THE WEEKEND...IT
LOOKS AS IF WE WILL GET A SHOT OF SEASONABLY COLD AIR BY THE END OF
THIS PERIOD. KEEP IN MIND THAT THIS IS LOOKING OUT TO DAY 7...BUT
THERE IS A SUGGESTION BY THE MEDIUM RANGE PACKAGES THAT A
SIGNIFICANT SHORTWAVE WILL HELP TO AMPLIFY AN ALREADY EXISTING
TROUGH OVER THE EASTERN U.S.
THE ORIGINS OF THIS SHORTWAVE CAN BE SEEN IN WV IMAGERY OVER
NORTHERN SIBERIA. AS THIS IMPRESSIVE FEATURE WEAKENS...ENERGY WILL
BE EJECTED ACROSS THE HIGH ARCTIC TO ALASKA WHERE IT IS FORECAST TO
DISLODGE A CLOSED LOW. THE RESULTING SHORTWAVE WILL THEN DROP `DOWN
THE CHUTE` ACROSS BRITISH COLUMBIA TO THE CENTRAL U.S. AT THE START
OF THIS PERIOD...AND OVER THE NATIONS MID SECTION OVER THE COURSE OF
THE WEEKEND.
THIS WILL DEEPEN AND ENERGIZE THE EASTERN U.S. TROUGH WITH COLDER
AIR SETTLING OVER OUR REGION LATE IN THE WEEKEND AND EARLY NEXT
WEEK. SUCH A PATTERN WOULD ALSO LIKELY SPAWN A COASTAL STORM...BUT
THAT WOULD NOT BE AN ISSUE FOR OUR REGION. NOW...LETS LOOK AT THE
DETAILS ON A MORE LOCAL LEVEL.
SFC BASED RIDGING WILL MOVE ACROSS OUR REGION ON FRIDAY. THIS WILL
CLEAR OUT THE PCPN FROM WEST TO EAST WITH THE ONLY REMAINING MENTION
OF PCPN BEING OVER THE EASTERN LAKE ONTARIO REGION. H85 TEMPS IN THE
VCNTY OF -4C WILL SUPPORT AFTERNOON TEMPS IN THE 30S TO NEAR 40F.
THE RIDGE WILL MOVE EAST ON SATURDAY AS A DIGGING TROUGH WILL BE
FOUND OVER THE MISSISSIPPI VALLEY AND UPPER GREAT LAKES. THE
LOWERING HGTS ACROSS THE GREAT LAKES WILL HELP SOME COLDER AIR TO
SAG ACROSS THE FORECAST AREA WITH WINDS FRESHENING AS A RESULT OF
STRONGER WINDS BELOW H85.
IT WILL BECOME SOMEWHAT UNSETTLED SATURDAY NIGHT AND SUNDAY AS THE
BASE OF THE SHARPENED H5 TROUGH WILL SWING ACROSS THE LOWER GREAT
LAKES. IT WILL BECOME COLDER WITH SCATTERED SNOW SHOWERS AND
CONCENTRATED LAKE SNOWS SOUTHEAST OF THE LAKES.
FINALLY FOR SUNDAY NIGHT AND MONDAY...THE CORE OF THE COOLEST AIR
WILL BE MOVING ACROSS EASTERN CANADA WITH H85 TEMPS GENERALLY IN THE
MINUS TEENS FOR OUR FORECAST AREA. WHILE THIS WOULD PROMOTE SOME
LAKE EFFECT SNOWS...LOW LEVEL RIDGING SHOULD LIMIT ACCUMULATIONS.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
ALL TAF SITES EXCEPT JHW REMAIN AT VFR AS OF 21Z. JHW UNDER MVFR
CIGS AS A LOW LEVEL INVERSION WILL CONTINUE TO KEEP LOW LEVEL
MOISTURE TRAPPED NEAR THE SFC THERE.
SOME CONVECTIVE SHOWERS HAVE RECENTLY DEVELOPED AHEAD OF THE COLD
FRONT OFF TO THE WEST WHERE ISOLATED LIGHTNING HAS BEEN OBSERVED.
THE TAFS HAVE BEEN AMENDED FOR TIMING OF ARRIVAL OF SHOWERS
ASSOCIATED ALONG THE FRONT AND ANY SCT ACTIVITY PREFRONTAL. FRONT
WILL BE PASSING FORECAST AREA IN THE 23Z-02Z TIME FRAME. ADDED CB
TO JHW/BUF/IAG AS AN ISOLATED STROKE OF LIGHTNING IS POSSIBLE WITH
WEAK INSTABILITY ALONG THE FRONT. CIGS WERE LOWERED TO MVFR DURING
FRONTAL SHOWER ACTIVITY AT ALL SITES.
WIND SHEAR STILL REMAINS AN ISSUE INTO AHEAD OF THE FRONT AS MODEL TIME
SECTIONS SHOW LOW LEVEL JET OF 50+ KTS AT 1-2 KFT. WINDS WILL
VEER TO SW WITH COLD ADVECTION OCCURRING BEHIND THE FRONT. THIS
WILL ERODE THE PRESENT INVERSION IN PLACE OVER THE AREA AND HIGHER
WINDS WILL BE ABLE TO MIX DOWN TO THE SURFACE WITH GUSTS TO 40KTS
POSSIBLE DURING THE EVENING POST FRONTAL. CONDITIONS WILL NOT
CHANGE MUCH FOR THE SECOND HALF OF THE TAF PERIOD WITH MVFR CIGS
AND GUSTY SW WINDS EXPECTED.
ANOTHER CONCERN THAT WILL HAVE TO BE WATCHED EARLY TUESDAY IS THE
CHANCE FOR ZDR 09Z-12Z. RECENT NAM MODEL INDICATED SATURATED LOW
LEVELS WITH SUB-FREEZING TEMPS BUT DRY AIR IN THE SNOW GROWTH ZONE
COLD YIELD SOME PATCHY ZDR.
OUTLOOK...
WEDNESDAY...VFR.
THURSDAY AND FRIDAY...MAINLY VFR WITH A CHANCE OF RAIN/SNOW SHOWERS.
SATURDAY...VFR WITH CHANCE FOR SNOW SHOWERS.
&&
.MARINE...
A COLD FRONT WILL SWEEP ACROSS THE LAKES TONIGHT BRINGING FRESH
SOUTHWESTERLIES WITH A FEW GUSTS TO GALE FORCE POSSIBLE ACROSS
EASTERN LAKE ERIE. STRONG WINDS MIXING DOWN TO THE SURFACE MAY BRING
GALES TO THE OPEN WATERS OF WESTERN LAKE ONTARIO OVERNIGHT AS WELL.
SMALL CRAFT ADVISORY LEVEL WESTERLIES WILL REMAIN IN PLACE ACROSS
THE LAKES THROUGH MUCH OF TUESDAY NIGHT BEFORE HIGH PRESSURE BUILDS
ACROSS THE REGION WEDNESDAY...BRINGING A PERIOD OF CALMER WINDS AND
WAVES THAT WILL LAST INTO THURSDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WIND ADVISORY UNTIL 5 AM EST TUESDAY FOR NYZ001-002-010-011-
019-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 6 PM EST TUESDAY FOR LEZ020.
GALE WARNING FROM 9 PM THIS EVENING TO 7 AM EST
TUESDAY FOR LOZ062.
SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR
LOZ042>045.
&&
$$
SYNOPSIS...WOOD
NEAR TERM...WOOD
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...SMITH
MARINE...WOOD
AREA FORECAST DISCUSSION
NWS BUFFALO NY
350 PM EST MON JAN 23 2012
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS WESTERN NEW YORK TONIGHT BRINGING
SHOWERS ALONG WITH STRONG GUSTY WINDS. LAKE EFFECT EFFECT SHOWERS
DEVELOPING IN THE WAKE OF THE FRONT ON TUESDAY WILL BRING LIGHT SNOW
ACCUMULATIONS TO THE NORTH COUNTRY WITH LITTLE OR NO ACCUMULATION
EAST OF LAKE ERIE. HIGH PRESSURE WILL BRING A BRIEF RETURN TO QUIET
WEATHER ON WEDNESDAY BEFORE THE NEXT SYSTEM BRINGS ANOTHER CHANCE OF
PRECIPITATION THURSDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
THE PRIMARY WEATHER MAKER FOR WESTERN NEW YORK WILL BE A MATURE LOW
PRESSURE SYSTEM CURRENTLY CENTERED OVER THE EASTERN END OF
MICHIGAN/S UPPER PENINSULA. THE LOW WILL LIFT INTO WESTERN QUEBEC
TONIGHT AS WHILE COLD AIR WRAPPING INTO THE LOW WILL SWEEP A STRONG
COLD FRONT ACROSS WESTERN NEW YORK MAKING STRONG WINDS AND FALLING
TEMPERATURES THE MAIN FORECAST CONCERNS FOR TONIGHT.
AS THE AFOREMENTIONED COLD FRONT MOVES ACROSS THE REGION
TONIGHT...EXPECT STRONGER WINDS ALOFT TO MIX DOWN TO THE SURFACE
CREATING GUSTY WINDS TONIGHT ACROSS WESTERN NEW YORK. LATEST MODEL
GUIDANCE SUGGESTS THAT THE CORE OF THE SOUTHWESTERLY LOW LEVEL JET
WILL STAY ACROSS AND TO THE WEST OF THE NIAGARA
FRONTIER...SUGGESTING THAT ADVISORY LEVEL WINDS WITH GUSTS TO AROUND
50 MPH WILL BE LIMITED TO THE WESTERNMOST COUNTIES IN NEW YORK. THE
JET LIFTS NORTH ACROSS LAKE ONTARIO OVERNIGHT SPARING THE NORTH
COUNTRY FROM THE STRONGEST WINDS. EXPECT TEMPERATURES TO DROP
MARKEDLY BEHIND THE FRONT WITH LOWS BOTTOMING OUT IN THE UPPER 20S
TO NEAR 30 ACROSS FAR WESTERN NEW YORK AND THE SOUTHERN TIER. THE
COLD AIR WILL TAKE A LITTLE LONGER TO REACH AREAS EAST OF LAKE
ONTARIO WHERE TEMPERATURES SHOULD REMAIN JUST ABOVE FREEZING.
REGARDING THE PRECIPITATION FORECAST FOR TONIGHT...CURRENT RADAR OBS
INDICATE ANOTHER BAND OF SHOWERS WITH ISOLATED THUNDER OVER
WESTERN OHIO ASSOCIATED WITH FRONTAL FORCING ALONG THE COLD
FRONTAL BOUNDARY WITH ADDITIONAL ENHANCEMENT FROM INCREASED
INSOLATION/DIABATIC HEATING DUE TO A DRY SLOT MOVING ACROSS THAT
REGION. HRRR MODEL CURRENTLY HAS A GOOD HANDLE ON THE SHOWER
ACTIVITY...BRINGING IT INTO THE NIAGARA FRONTIER BY EARLY EVENING
AND QUICKLY FALLING APART BY THE TIME IT REACHES THE GENESEE
VALLEY AS INSTABILITY AND SYNOPTIC FORCING WEAKENS. WILL CARRY
LIKELY TO CATEGORICAL POPS FOR THE WESTERN COUNTIES WITH A SLIGHT
CHANCE OF THUNDER THIS EVENING TRANSITIONING TO CHANCE POPS FOR
THE EASTERN HALF OF THE FORECAST AREA.
COLD AIR FILTERING IN BEHIND THE COLD FRONT NECESSITATES A
DISCUSSION OF LAKE EFFECT POTENTIAL ON TUESDAY. WHILE 850MB TEMPS
GET NOMINALLY COLD ENOUGH FOR LAKE EFFECT...AROUND -10C TO -12C
ACROSS LAKE ERIE WITH A FAVORABLE WEST-SOUTHWEST WIND AND LOW
SHEAR...THE PRESENCE OF SUBSTANTIAL DRY AIR IN THE DENDRITIC GROWTH
ZONE AND AN INVERSION LEVEL RUNNING AT 5KFT OR LOWER IS NOT
IMPRESSIVE. THE REGIONAL GEM MODEL KEEPS THE DEEPER MOISTURE A
LITTLE FARTHER SOUTH...RESULTING IN A SLIGHTLY MORE FAVORABLE
PROFILE FOR SNOW. GIVEN THIS UNCERTAINTY...WILL KEEP POPS LIMITED TO
CHANCE EAST OF LAKE ERIE AND KEEP WEATHER LIMITED TO FLURRIES. EAST
OF LAKE ONTARIO...LONGER FETCH OFF OF THE LAKE AND SLIGHTLY COLDER
AIR IN THE LOWER LEVELS MAY RAISE THE INVERSION JUST ENOUGH TO
GENERATE SOME LIGHT SNOW SHOWERS...MAINLY ACROSS JEFFERSON AND LEWIS
COUNTIES...THOUGH ACCUMULATIONS WILL GENERALLY RUN IN THE
NEIGHBORHOOD OF 1-3 INCHES AT BEST.
PLENTY OF COLD AIR AND LAKE INDUCED CLOUD COVER IN PLACE WILL MAKE
FOR A TYPICAL DAY...FOR LATE JANUARY...WITH HIGHS RANGING FROM THE
UPPER 20S TO LOWER 30S ACROSS THE FORECAST AREA.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
A PROGRESSIVE PATTERN WILL BE IN PLACE ACROSS NORTH AMERICA DURING
THIS PERIOD AS THE BROAD POLAR VORTEX THAT HAS BEEN IN PLACE OVER
CANADA WILL RETROGRADE TO ALASKA. THIS WILL KEEP A STRONG ZONAL JET
OVER THE GULF OF ALASKA AND PACIFIC NORTHWEST...WHICH WILL RESULT IN
A CONTINUAL FEED OF PACIFIC MODIFIED AIR OVER THE LOWER 48. OUR
TEMPERATURES WILL AVERAGE ABOVE NORMAL AS A RESULT...WITH LITTLE IN
THE WAY OF SIGNIFICANT WEATHER. THE DETAILS...
A SECONDARY COLD FRONT WILL DROP ACROSS THE LOWER GREAT LAKES ON
TUESDAY NIGHT...AND WHILE A VERY SHORT LIVED POCKET OF -10C H85 AIR
WILL SUPPORT SOME LAKE EFFECT EAST OF LK ONTARIO...SNOWFALL AMOUNTS
WILL NOT BE SIGNIFICANT. LAKE INDUCED CONVECTION EARLY ON SHOULD
DISINTEGRATE AS PACIFIC BASED AIR MOVES IN AND PUMPS H85`S TO -4C.
OTHERWISE...ANY NUISANCE SNOW SHOWERS ASSOCIATED WITH THE FRONTAL
PASSAGE WILL QUICKLY GIVE WAY TO CLEARING SKIES AS HIGH PRESSURE
WILL BUILD ACROSS ALL OF THE GREAT LAKES REGION.
WEDNESDAY SHOULD BE A FAIRLY NICE DAY ACROSS THE REGION AS A LARGE
AREA OF HIGH PRESSURE WILL DRIFT ACROSS PENNSYLVANIA. WILL BUMP MAX
TEMPS UP A BIT FROM CONTINUITY...AS H85`S ARE EXPECTED TO MODERATE
TO AROUND ZERO/-2C. THIS SHOULD SUPPORT AFTERNOON READINGS IN THE
MID 30S ACROSS THE LOWER ELEVATIONS...WHILE THE NORTH COUNTRY WILL
EXPERIENCE HIGHS CLOSER TO THE SEASONAL NORM IN THE UPPER 20S.
A WEAKLY DIVERGENT FLOW WILL ACCOMPANY A JET STREAK ACROSS THE LOWER
GREAT LAKES ON WEDNESDAY NIGHT...AND THIS WILL LIKELY LEAD TO AN
INCREASE IN CLOUD COVER. GIVEN THE DEARTH OF MOISTURE AND OVERALL
SYNOPTIC LIFT...WILL ONLY CARRY SLGT CHC POPS.
A POTENT SHORTWAVE WILL THEN DIG ACROSS THE UPPER MISSISSIPPI VALLEY
ON THURSDAY...AND THIS WILL HELP TO AMPLIFY AN ALREADY BULGING
SHORTWAVE RIDGE OVER OUR FORECAST AREA. WHILE THIS WILL PROMOTE FAIR
WEATHER ACROSS OUR REGION FOR THE BULK OF THE DAY...WE WILL
EXPERIENCE AN INCREASE IN CLOUD COVER AS LOW LEVEL MOISTURE WILL
POOL IN ADVANCE OF THE NEXT FRONTAL SYSTEM. THERE COULD EVEN BE A
COUPLE LIGHT RAIN SHOWERS IN THE AFTERNOON OVER THE FAR WESTERN
COUNTIES.
FOR THURSDAY NIGHT...OUR REGION WILL FIND ITSELF STRADDLED BY A PAIR
OF STORM SYSTEMS. THE AFOREMENTIONED UPPER MISSISSIPPI VALLEY SHORT
WAVE WILL TRACK ACROSS SOUTHERN ONTARIO WHILE A SFC LOW GENERATED IN
THE SOUTHERN BRANCH IS EXPECTED TO MAKE ITS WAY ACROSS THE
APPALACHIANS TO VIRGINIA. A PACIFIC BASED COLD FRONT STRETCHING
BETWEEN THE TWO WILL CROSS OUR FORECAST AREA DURING THE COURSE OF
THE NIGHT. SINCE FORCING BETWEEN THE TWO SYSTEMS SHOULD NOT BE VERY
STRONG...LIGHT LOW QPF SHOWERY PCPN COULD PROVE TO BE PROBLEMATIC AS
A WINTRY MIX WILL BE POSSIBLE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
WHILE TEMPERATURES WILL AVERAGE ABOVE NORMAL FOR THE WEEKEND...IT
LOOKS AS IF WE WILL GET A SHOT OF SEASONABLY COLD AIR BY THE END OF
THIS PERIOD. KEEP IN MIND THAT THIS IS LOOKING OUT TO DAY 7...BUT
THERE IS A SUGGESTION BY THE MEDIUM RANGE PACKAGES THAT A
SIGNIFICANT SHORTWAVE WILL HELP TO AMPLIFY AN ALREADY EXISTING
TROUGH OVER THE EASTERN U.S.
THE ORIGINS OF THIS SHORTWAVE CAN BE SEEN IN WV IMAGERY OVER
NORTHERN SIBERIA. AS THIS IMPRESSIVE FEATURE WEAKENS...ENERGY WILL
BE EJECTED ACROSS THE HIGH ARCTIC TO ALASKA WHERE IT IS FORECAST TO
DISLODGE A CLOSED LOW. THE RESULTING SHORTWAVE WILL THEN DROP `DOWN
THE CHUTE` ACROSS BRITISH COLUMBIA TO THE CENTRAL U.S. AT THE START
OF THIS PERIOD...AND OVER THE NATIONS MID SECTION OVER THE COURSE OF
THE WEEKEND.
THIS WILL DEEPEN AND ENERGIZE THE EASTERN U.S. TROUGH WITH COLDER
AIR SETTLING OVER OUR REGION LATE IN THE WEEKEND AND EARLY NEXT
WEEK. SUCH A PATTERN WOULD ALSO LIKELY SPAWN A COASTAL STORM...BUT
THAT WOULD NOT BE AN ISSUE FOR OUR REGION. NOW...LETS LOOK AT THE
DETAILS ON A MORE LOCAL LEVEL.
SFC BASED RIDGING WILL MOVE ACROSS OUR REGION ON FRIDAY. THIS WILL
CLEAR OUT THE PCPN FROM WEST TO EAST WITH THE ONLY REMAINING MENTION
OF PCPN BEING OVER THE EASTERN LAKE ONTARIO REGION. H85 TEMPS IN THE
VCNTY OF -4C WILL SUPPORT AFTERNOON TEMPS IN THE 30S TO NEAR 40F.
THE RIDGE WILL MOVE EAST ON SATURDAY AS A DIGGING TROUGH WILL BE
FOUND OVER THE MISSISSIPPI VALLEY AND UPPER GREAT LAKES. THE
LOWERING HGTS ACROSS THE GREAT LAKES WILL HELP SOME COLDER AIR TO
SAG ACROSS THE FORECAST AREA WITH WINDS FRESHENING AS A RESULT OF
STRONGER WINDS BELOW H85.
IT WILL BECOME SOMEWHAT UNSETTLED SATURDAY NIGHT AND SUNDAY AS THE
BASE OF THE SHARPENED H5 TROUGH WILL SWING ACROSS THE LOWER GREAT
LAKES. IT WILL BECOME COLDER WITH SCATTERED SNOW SHOWERS AND
CONCENTRATED LAKE SNOWS SOUTHEAST OF THE LAKES.
FINALLY FOR SUNDAY NIGHT AND MONDAY...THE CORE OF THE COOLEST AIR
WILL BE MOVING ACROSS EASTERN CANADA WITH H85 TEMPS GENERALLY IN THE
MINUS TEENS FOR OUR FORECAST AREA. WHILE THIS WOULD PROMOTE SOME
LAKE EFFECT SNOWS...LOW LEVEL RIDGING SHOULD LIMIT ACCUMULATIONS.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
ALL TAF SITES EXCEPT JHW REMAIN AT VFR AS OF 18Z. KART VIS MAY DROP
INTO MVFR WITH LINE OF RAIN SHOWERS MOVING THROUGH BUT REMAIN VFR
OTHERWISE. JHW UNDER IFR CIGS AS A LOW LEVEL INVERSION WILL CONTINUE TO
KEEP LOW LEVEL MOISTURE TRAPPED NEAR THE SFC THERE.
WIND SHEAR STILL REMAINS AN ISSUE INTO THE AFTERNOON AS MODEL TIME
SECTIONS SHOW LOW LEVEL JET OF 50+ KTS AT 1-2 KFT. LLWS WILL REMAIN
POSSIBLE EVEN WITH GUSTY SURFACE WINDS DUE TO STRENGTH OF LLJ. A
COLD FRONT TO THE WEST OVER WESTERN OH WILL WORK ITS WAY EASTWARD
TOWARD THE AREA THIS EVENING. THE FRONT WILL BRING A SECOND AREA OF
RAIN SHOWERS ALONG THE BOUNDARY THEN VEERING WINDS TO SW WITH
COLD ADVECTION OCCURRING ALOFT. THIS WILL ERODE THE INVERSION AND
HIGHER WINDS WILL BE ABLE TO MIX DOWN TO THE SURFACE WITH GUSTS TO
40KTS POSSIBLE DURING THE EVENING POST FRONTAL. THE FRONT SHOULD
ALSO HELP TO IMPROVE JHW TO MVFR. CONDITIONS WILL NOT CHANGE MUCH
FOR THE SECOND HALF OF THE TAF PERIOD WITH MVFR CIGS AND GUSTY SW
WINDS EXPECTED.
ANOTHER CONCERN THAT WILL HAVE TO BE WATCHED EARLY TUESDAY IS THE
CHANCE FOR ZDR 09Z-12Z. RECENT NAM MODEL INDICATED SATURATED LOW
LEVELS WITH SUB-FREEZING TEMPS BUT DRY AIR IN THE SNOW GROWTH ZONE
COLD YIELD SOME PATCHY ZDR.
OUTLOOK...
WEDNESDAY...VFR.
THURSDAY AND FRIDAY...MAINLY VFR WITH A CHANCE OF RAIN/SNOW SHOWERS.
SATURDAY...VFR WITH CHANCE FOR SNOW SHOWERS.
&&
.MARINE...
A COLD FRONT WILL SWEEP ACROSS THE LAKES TONIGHT BRINGING FRESH
SOUTHWESTERLIES WITH A FEW GUSTS TO GALE FORCE POSSIBLE ACROSS
EASTERN LAKE ERIE. STRONG WINDS MIXING DOWN TO THE SURFACE MAY BRING
GALES TO THE OPEN WATERS OF WESTERN LAKE ONTARIO OVERNIGHT AS WELL.
SMALL CRAFT ADVISORY LEVEL WESTERLIES WILL REMAIN IN PLACE ACROSS
THE LAKES THROUGH MUCH OF TUESDAY NIGHT BEFORE HIGH PRESSURE BUILDS
ACROSS THE REGION WEDNESDAY...BRINGING A PERIOD OF CALMER WINDS AND
WAVES THAT WILL LAST INTO THURSDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WIND ADVISORY UNTIL 5 AM EST TUESDAY FOR NYZ001-002-010-011-
019-085.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 6 PM EST TUESDAY FOR LEZ020.
GALE WARNING FROM 9 PM THIS EVENING TO 7 AM EST
TUESDAY FOR LOZ062.
SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR
LOZ042>045.
&&
$$
SYNOPSIS...WOOD
NEAR TERM...WOOD
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...SMITH
MARINE...WOOD
AREA FORECAST DISCUSSION
NWS BUFFALO NY
427 AM EST MON JAN 23 2012
.SYNOPSIS...
A STRONG AREA OF LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES
REGION TODAY WITH GUSTY WINDS AND A PERIOD OF SHOWERS. THERE
IS EVEN A CHANCE OF A THUNDERSTORM IN A FEW SPOTS AS TEMPERATURES
BRIEFLY WARM TO WELL ABOVE AVERAGE. COOLER AIR WILL FILTER BACK IN
TONIGHT INTO TUESDAY ON CONTINUED GUSTY WINDS FOLLOWING A COLD FRONT
WITH A FEW RAIN AND SNOW SHOWERS. HIGH PRESSURE WILL BUILD INTO THE
REGION WEDNESDAY WITH A DRY DAY BEFORE THE NEXT SYSTEM BRINGS A
CHANCE OF RAIN OR SNOW ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A STRONG AREA OF LOW PRESSURE WILL TRACK ACROSS THE UPPER LAKE
TODAY. THIS WILL RESULT IN ACTIVE WEATHER FOR WESTERN NEW YORK
TODAY...WITH SEVERAL FORECAST ISSUES TO CONSIDER.
FOR TODAY...THE MOST CRITICAL FORECAST CONCERN IS THE POTENTIAL FOR
STRONG WIND GUSTS. A 50 KT LOW LEVEL JET DOWN TO ABOUT 2000 FEET
WILL CONTINUE TO SPREAD EAST ACROSS THE REGION. INITIALLY...EXPECT
THIS TO ONLY MIX PARTIALLY...WITH HIGHER TERRAIN LIKELY TO SEE GUSTS
TO 40 MPH OR SO...WHILE WINDS REMAIN RELATIVELY CALM FROM BUF-ROC
NORTHWARD...WHERE THE SOUTHERLY FLOW WILL INITIALLY STRUGGLE TO MIX
DOWN. THESE CONDITIONS SHOULD PERSIST UNTIL AROUND MID-MORNING.
THE POTENTIAL FOR GUSTY WINDS WILL INCREASE LATE MORNING INTO THIS
AFTERNOON...AS THE CORE OF THE LOW LEVEL JET MOVES ACROSS THE
REGION. WHILE MODELS DIFFER A BIT ON STRENGTH AND TIMING...THE
NAM12/RUC/RGEM/GFS ALL SHOW A QUITE IMPRESSIVE LOW LEVEL JET OF 55
TO 70 KTS CROSSING THE REGION. A LINE OF SHOWERS AND THUNDERSTORMS
HAVE DEVELOPED ALONG THIS. THE NAM12/RGEM ARE IN GENERAL SUPPORT OF
THE HRRR...ALL OF WHICH DO A FAIRLY GOOD JOB CAPTURING THIS LINE.
USING THIS GUIDANCE...EXPECT BOTH THE LLJ AND LINE OF SHOWERS WITH
EMBEDDED THUNDERSTORMS TO ENTER WESTERN NEW YORK MID TO LATE
MORNING. BY THIS TIME...EXPECT THE LINE TO BE WEAKER THAN IT IS
NOW...WITH THE LINE LIKELY TO WEAKEN ACROSS THE FINGER LAKES
REGION...AS THE LINE SPLITS INTO TWO SEGMENTS AS IT CROSSES THE CWA
EARLY AFTERNOON. BY ITS OWN RIGHT...THE STRONG FLOW ALOFT IS LIKELY
TO BRING STRONG WINDS TO HIGHER TERRAIN TODAY. IN ADDITION TO
THIS...IT WILL NOT TAKE MUCH TO MIX STRONG WINDS ALOFT DOWN WITH
THIS...AS WINDS TO 40 KTS WILL ONLY BE 1000 FT ALOFT. SO WHILE THE
LINE IS NOT LIKELY TO BE IMPRESSIVE BY SUMMER STANDARDS...IT WILL
BEAR WATCHING TODAY...AS IT MAY HELP TO BRIEFLY MIX DOWN STRONG
WINDS ALOFT...POTENTIALLY RESULTING IN DAMAGING WINDS. FOR
NOW...WILL EXPAND THE WIND ADVISORY TO INCLUDE THE NIAGARA
FRONTIER...WHERE THIS LINE MAY STILL BE ORGANIZED ENOUGH TO HELP
WINDS MIX DOWN LATE THIS MORNING AND EARLY AFTERNOON. WILL KEEP
GUSTS AT AROUND 50 MPH...AND WILL ALLOW SHORT FUSED PRODUCTS HANDLE
THE POTENTIAL FOR LOCALLY HIGHER AND/OR DAMAGING GUSTS.
BY THIS AFTERNOON...EXPECT THE LINE OF SHOWERS TO HAVE SPLIT INTO A
NORTHERN PORTION...WHICH WILL TRACK ACROSS LAKE ONTARIO...AND A
SOUTHERN PORTION...WHICH SHOULD TRACK SOUTH AND EAST OF THE CWA.
WILL HAVE TO CONTINUE TO WATCH THE NORTHERN SEGMENT FOR GUSTY
WINDS...WHILE LOCATIONS WEST OF ROCHESTER MAY ACTUALLY GET A LULL IN
THE ACTION. THE HRRR IS SUPPORTED BY NAM12/RGEM IN A PERIOD WITH
JUST SCATTERED SHOWERS BEHIND THE LLJ...BUT STILL AHEAD OF THE
SURFACE FRONT.
THE SURFACE FRONT SHOULD CROSS THE REGION THIS EVENING...WITH WINDS
SHIFTING TO THE SOUTHWEST. TODAY/S 00Z RUNS ARE STRONGER THAN LAST
NIGHT WITH THE POST FRONTAL WINDS...WITH THE NAM SHOWING A PERIOD OF
50 KTS AT 925 MB...IN A SWELL ALIGNED SW FLOW. EXPECT THIS WILL
BRING ANOTHER ROUND OF GUSTY WINDS TO THE NIAGARA FRONTIER...AND
ALONG THE IMMEDIATE LAKE ERIE SHORELINE. FOR THIS REASON...WILL
EXTEND THE WIND ADVISORY TO CAPTURE POST-FRONTAL WINDS IN THESE
LOCATIONS. THE COLD FRONT MAY BRING SOME ADDITIONAL SHOWERS AS
WELL...WITH THIS LIKELY TO BE MOST ORGANIZED EAST OF LAKE ONTARIO.
WHILE ALL THIS GOES ON...TEMPERATURES HAVE RISEN ABOVE FREEZING IN
MOST LOCATIONS...THOUGH THERE ARE A FEW SPOTS STILL NEAR THE
FREEZING MARK. TEMPERATURES WILL CONTINUE TO RISE SLOWLY THROUGH
MID-MORNING. EXPECT THE PASSAGE OF THE STRONG WINDS ALOFT TO KEY
MIXING...AND A RATHER ABRUPT RISE IN TEMPERATURES INTO THE UPPER 40S
TO LOWER 50S. TEMPERATURES WILL REMAIN QUITE WARM UNTIL THE COLD
FRONT CROSSES THIS EVENING. ANY LINGERING SHOWERS LATE TONIGHT
SHOULD CHANGE OVER TO SNOW SHOWERS. EXPECT THESE TO BE QUITE
WIDESPREAD...WITH NO ACCUMULATION.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
A WEST TO SOUTHWEST FLOW OF COLDER AIR WILL BUILD ACROSS THE AREA
TUESDAY AS LOW PRESSURE TRACKS EAST ACROSS QUEBEC. SYNOPTIC MOISTURE
WRAPPING IN BEHIND THE LOW WILL BRING A CHANCE OF SNOW SHOWERS TO
THE ENTIRE AREA...AND THERE MAY BE A LIMITED RESPONSE FROM THE LAKES
WITH THE NAM NOW SHOWING COLDER AIR (AVERAGING AROUND -12C)
ADVECTING ACROSS THE AREA DURING THE AFTERNOON. THE POTENTIAL FOR
SOME LAKE ENHANCED SNOW LOOKS TO BE GREATER EAST OF LAKE ONTARIO
WHERE THE NAM SHOWS DEEPER MOISTURE...MORE FAVORABLE SNOW GROWTH AND
GREATER LAKE INDUCED INSTABILITY. SNOW ACCUMULATIONS WILL LIKELY
REMAIN UNDER ADVISORY CRITERIA...HOWEVER.
BREEZY TO WINDY CONDITIONS WILL PERSIST ON TUESDAY...ESPECIALLY
DOWNWIND OF THE LAKES WHERE AN ADDITIONAL INFLUENCE FROM FUNNELING
WILL COME INTO PLAY.
AS THE SURFACE LOW HEADS EAST TOWARD THE CANADIAN MARITIMES TUESDAY
NIGHT...A SECONDARY TROUGH WILL DROP SOUTH ACROSS NEW YORK STATE.
WEAK CONVERGENCE ALONG THIS BOUNDARY...COMBINED WITH ADDITIONAL LIFT
FROM A PASSING UPPER LEVEL TROUGH MAY GENERATE A FEW MORE SNOW
SHOWERS DURING THE FIRST HALF OF THE NIGHT...WHILE SOME LAKE
ENHANCED SNOW LINGERS EAST OF LAKE ONTARIO. DURING THE SECOND HALF
OF THE NIGHT...DRIER AIR WILL BE WORKING IN FROM THE WEST AS HIGH
PRESSURE BUILDS EAST TOWARD THE LOWER LAKES. TEMPERATURES ALOFT WILL
ALSO BEGIN TO MODERATE AS THE CORE OF THE COLDEST AIR SHIFTS EAST
INTO NORTHERN NEW ENGLAND WITH THE DEPARTING UPPER LEVEL TROUGH.
THEREAFTER...SURFACE RIDGING WILL BUILD ACROSS THE AREA WEDNESDAY
...BRINGING PROGRESSIVELY DRIER AIR. THIS WILL HELP TO END ANY
UPSLOPE/LAKE-ENHANCED SNOW SHOWERS THAT MAY LINGER EAST OF LAKE
ONTARIO DURING THE MORNING. EXPECT DRY CONDITIONS TO CONTINUE
WEDNESDAY NIGHT AS THE SURFACE HIGH CRESTS OVER NEW YORK AND
PA. SOME INCREASE IN CLOUDS IS LIKELY LATER WEDNESDAY NIGHT AS
MOISTURE BEGINS TO WORK NORTH ALONG AN INVERTED TROUGH THAT IS
FORECAST TO EXTEND NORTH FROM A DEVELOPING LOWER MISSISSIPPI VALLEY
LOW.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AFTER THE SURFACE RIDGE DRIFTS OFF THE EAST COAST WEDNESDAY NIGHT...
THE MEDIUM RANGE MODELS INDICATE THAT A DOUBLE-BARRELED LOW PRESSURE
MAY IMPACT OUR AREA LATE IN THE WORK WEEK. THE VARIOUS GUIDANCE
PACKAGES HAVE STARTED TO COME MORE IN LINE IN THEIR HANDLING OF THIS
SYSTEM WITH THE 12Z/22 CYCLE... WITH THE GFS/GEM GLOBAL AND ECMWF
NOW ALL INDICATING A NORTHERN STREAM WAVE THAT PASSES BY WELL TO OUR
NORTH ACROSS ONTARIO AND QUEBEC THURSDAY INTO FRIDAY...WHILE A MUCH
WEAKER INITIAL SOUTHERN STREAM WAVE PASSES BY WELL TO OUR SOUTH. IN
BETWEEN IS A WEAK CONNECTING TROUGH WITH ONLY VERY MEAGER ASSOCIATED
QPF SUGGESTED BY ALL THREE MODELS...THOUGH I SUSPECT THAT THIS IS
PROBABLY A LITTLE UNDERDONE. ACCORDINGLY...WILL CONTINUE TO CARRY A
ROUND OF BROADBRUSH LOW CHANCE POPS FOR THIS PERIOD...WHILE KEEPING
PTYPE AT LEAST A A RAIN/SNOW MIX OR EVEN JUST PLAIN RAIN GIVEN THE
RATHER MILD NATURE OF OUR AIRMASS.
FOLLOWING THE PASSAGE OF THIS SYSTEM...INCREASING RIDGING/DRYING
SHOULD THEN ONCE AGAIN TAKE HOLD AND BRING A RETURN TO MAINLY DRY
WEATHER FOR LATER FRIDAY AFTERNOON AND/OR FRIDAY NIGHT. AFTER
THAT...THE GFS/ECMWF BOTH SUGGEST THAT INCREASING LARGE-SCALE
TROUGHING WILL BRIEFLY DIG SOUTHEAST INTO THE GREAT LAKES AND
NORTHEAST NEXT WEEKEND. AT THE SURFACE...THIS WILL BE REFLECTED BY
THE PASSAGE OF YET ANOTHER COMPLEX AREA OF LOW PRESSURE...WITH A
POTENTIALLY MORE SIGNIFICANT SOUTHERN STREAM WAVE LARGELY MISSING
OUR AREA TO THE SOUTHEAST...WHILE A NORTHERN STREAM CLIPPER-TYPE
SYSTEM WORKS ACROSS OUR AREA...FOLLOWED BY A BRIEF SHOT OF
SEASONABLY COLDER CANADIAN AIR AND POSSIBLE LAKE EFFECT FOR SATURDAY
NIGHT AND SUNDAY. WILL COVER ALL OF THIS WITH ANOTHER ROUND OF
CHANCE POPS...WHILE BRINGING TEMPERATURES BACK TO SLIGHTLY BELOW
NORMAL LEVELS BY THE END OF THE PERIOD.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
STRONG LOW PRESSURE WILL LIFT ACROSS THE UPPER LAKES TODAY. THIS
WILL BRING SOME VERY ACTIVE WEATHER TO WESTERN AND NORTH CENTRAL
NEW YORK IN THE PROCESS...AS OUR REGION WILL INITIALLY EXPERIENCE
LOW LEVEL WIND SHEAR ISSUES BUT THAT WILL BE FOLLOWED BY GUSTY
SURFACE WINDS AND THERE WILL EVEN BE THE THREAT FOR SOME
CONVECTION.
THROUGH MID-MORNING...LLWS WILL BE THE MAIN AVIATION CONCERN.
WINDS ALOFT WILL INCREASE THROUGH MID-MORNING...WITH SHEAR LIKELY
TO GET STRONGER DURING THIS TIME. SCATTERED IFR/MFVR CIGS ARE
POSSIBLE...BUT THESE SHOULD LARGELY REMAIN ACROSS HIGHER TERRAIN.
A LINE OF SHOWERS WITH EMBEDDED THUNDERSTORMS WILL MOVE ACROSS THE
REGION MID TO LATE MORNING THROUGH EARLY AFTERNOON. THIS WILL
LIKELY BRING A COUPLE HOURS OF RAIN SHOWERS...AND POSSIBLY A
THUNDERSTORMS. SURFACE WINDS ARE ALSO LIKELY TO INCREASE WITH THIS
AS WELL.
OTHERWISE...IT MAY BE DRY FOR A GOOD PORTION OF THE AFTERNOON
BEHIND THIS FEATURE...WITH LLWS LAXING AS WINDS ALOFT MIX DOWN
BETTER.
A COLD FRONT WILL CROSS THIS EVENING...SHIFTING WINDS TO THE SW.
THIS WILL BRING ANOTHER ROUND OF GUSTY WINDS TO BUF-IAG. CIGS IN
THE WAKE OF THIS FRONT WILL DROP TO BETWEEN 1500 AND 2500 FEET FOR
THE EVENING HOURS...THEN TO IFR LEVELS OVERNIGHT.
OUTLOOK...
TUESDAY...AREAS OF MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR.
THURSDAY AND FRIDAY...MAINLY VFR WITH A CHANCE OF RAIN/SNOW SHOWERS.
&&
.MARINE...
EXPECT GUSTY SOUTHERLY WINDS TODAY...WITH SMALL CRAFT ADVISORIES IN
PLACE ACROSS THE REGION. THIS STILL LOOKS ON TRACK...WITH BRIEFLY
HIGHER GUSTS POSSIBLE AS A LINE OF SHOWERS AND THUNDERSTORMS MOVES
ACROSS LAKE ERIE MID AND LATE MORNING...AND ACROSS LAKE ONTARIO LATE
MORNING THROUGH THIS AFTERNOON. BRIEF PERIODS OF GUSTY WINDS TO GALE
FORCE ARE POSSIBLE IN THUNDERSTORMS.
A COLD FRONT WILL CROSS THE WATERS THIS EVENING...SHIFTING WINDS TO
THE SW. EXPECT NEAR GALE CONDITIONS ON LAKE ERIE LATE EVENING AND
OVERNIGHT...AS 925 MB WINDS INCREASE TO 50 KTS. SURFACE TEMPERATURES
BEHIND THE FRONT ARE NOT THAT COLD...WHICH WILL SOMEWHAT LIMIT
MIXING. THIS SAID...IT IS POSSIBLE THAT THE ADVISORY WILL NEED TO BE
UPGRADED TO GALES ON LAKE ERIE TONIGHT.
AFTER THIS...WINDS WILL GRADUALLY SHIFT TO THE WEST BEHIND THE
FRONT...WITH A FAIRLY PROLONGED PERIOD OF SMALL CRAFT ADVISORY CONDITIONS
EXPECTED TO LAST INTO WEDNESDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WIND ADVISORY FROM 9 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR NYZ007-008.
WIND ADVISORY FROM 9 AM THIS MORNING TO 4 AM EST TUESDAY FOR
NYZ001>003-010-011.
WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NYZ012>014-020-
021.
WIND ADVISORY UNTIL 4 AM EST TUESDAY FOR NYZ019-085.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 PM EST
TUESDAY FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR LEZ040-
041.
SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 PM
EST TUESDAY FOR LOZ030.
SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR
LOZ043>045.
SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 5 AM EST
WEDNESDAY FOR LOZ042.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
349 AM EST MON JAN 23 2012
.SYNOPSIS...
A STRONG AREA OF LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES
REGION TODAY WITH GUSTY WINDS AND A PERIOD OF SHOWERS. THERE
IS EVEN A CHANCE OF A THUNDERSTORM IN A FEW SPOTS AS TEMPERATURES
BRIEFLY WARM TO WELL ABOVE AVERAGE. COOLER AIR WILL FILTER BACK IN
TONIGHT INTO TUESDAY ON CONTINUED GUSTY WINDS FOLLOWING A COLD FRONT
WITH A FEW RAIN AND SNOW SHOWERS. HIGH PRESSURE WILL BUILD INTO THE
REGION WEDNESDAY WITH A DRY DAY BEFORE THE NEXT SYSTEM BRINGS A
CHANCE OF RAIN OR SNOW ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
A STRONG AREA OF LOW PRESSURE WILL TRACK ACROSS THE UPPER LAKE
TODAY. THIS WILL RESULT IN ACTIVE WEATHER FOR WESTERN NEW YORK
TODAY...WITH SEVERAL FORECAST ISSUES TO CONSIDER.
FOR TODAY...THE MOST CRITICAL FORECAST CONCERN IS THE POTENTIAL FOR
STRONG WIND GUSTS. A 50 KT LOW LEVEL JET DOWN TO ABOUT 2000 FEET
WILL CONTINUE TO SPREAD EAST ACROSS THE REGION. INITIALLY...EXPECT
THIS TO ONLY MIX PARTIALLY...WITH HIGHER TERRAIN LIKELY TO SEE GUSTS
TO 40 MPH OR SO...WHILE WINDS REMAIN RELATIVELY CALM FROM BUF-ROC
NORTHWARD...WHERE THE SOUTHERLY FLOW WILL INITIALLY STRUGGLE TO MIX
DOWN. THESE CONDITIONS SHOULD PERSIST UNTIL AROUND MID-MORNING.
THE POTENTIAL FOR GUSTY WINDS WILL INCREASE LATE MORNING INTO THIS
AFTERNOON...AS THE CORE OF THE LOW LEVEL JET MOVES ACROSS THE
REGION. WHILE MODELS DIFFER A BIT ON STRENGTH AND TIMING...THE
NAM12/RUC/RGEM/GFS ALL SHOW A QUITE IMPRESSIVE LOW LEVEL JET OF 55
TO 70 KTS CROSSING THE REGION. A LINE OF SHOWERS AND THUNDERSTORMS
HAVE DEVELOPED ALONG THIS. THE NAM12/RGEM ARE IN GENERAL SUPPORT OF
THE HRRR...ALL OF WHICH DO A FAIRLY GOOD JOB CAPTURING THIS LINE.
USING THIS GUIDANCE...EXPECT BOTH THE LLJ AND LINE OF SHOWERS WITH
EMBEDDED THUNDERSTORMS TO ENTER WESTERN NEW YORK MID TO LATE
MORNING. BY THIS TIME...EXPECT THE LINE TO BE WEAKER THAN IT IS
NOW...WITH THE LINE LIKELY TO WEAKEN ACROSS THE FINGER LAKES
REGION...AS THE LINE SPLITS INTO TWO SEGMENTS AS IT CROSSES THE CWA
EARLY AFTERNOON. BY ITS OWN RIGHT...THE STRONG FLOW ALOFT IS LIKELY
TO BRING STRONG WINDS TO HIGHER TERRAIN TODAY. IN ADDITION TO
THIS...IT WILL NOT TAKE MUCH TO MIX STRONG WINDS ALOFT DOWN WITH
THIS...AS WINDS TO 40 KTS WILL ONLY BE 1000 FT ALOFT. SO WHILE THE
LINE IS NOT LIKELY TO BE IMPRESSIVE BY SUMMER STANDARDS...IT WILL
BEAR WATCHING TODAY...AS IT MAY HELP TO BRIEFLY MIX DOWN STRONG
WINDS ALOFT...POTENTIALLY RESULTING IN DAMAGING WINDS. FOR
NOW...WILL EXPAND THE WIND ADVISORY TO INCLUDE THE NIAGARA
FRONTIER...WHERE THIS LINE MAY STILL BE ORGANIZED ENOUGH TO HELP
WINDS MIX DOWN LATE THIS MORNING AND EARLY AFTERNOON. WILL KEEP
GUSTS AT AROUND 50 MPH...AND WILL ALLOW SHORT FUSED PRODUCTS HANDLE
THE POTENTIAL FOR LOCALLY HIGHER AND/OR DAMAGING GUSTS.
BY THIS AFTERNOON...EXPECT THE LINE OF SHOWERS TO HAVE SPLIT INTO A
NORTHERN PORTION...WHICH WILL TRACK ACROSS LAKE ONTARIO...AND A
SOUTHERN PORTION...WHICH SHOULD TRACK SOUTH AND EAST OF THE CWA.
WILL HAVE TO CONTINUE TO WATCH THE NORTHERN SEGMENT FOR GUSTY
WINDS...WHILE LOCATIONS WEST OF ROCHESTER MAY ACTUALLY GET A LULL IN
THE ACTION. THE HRRR IS SUPPORTED BY NAM12/RGEM IN A PERIOD WITH
JUST SCATTERED SHOWERS BEHIND THE LLJ...BUT STILL AHEAD OF THE
SURFACE FRONT.
THE SURFACE FRONT SHOULD CROSS THE REGION THIS EVENING...WITH WINDS
SHIFTING TO THE SOUTHWEST. TODAY/S 00Z RUNS ARE STRONGER THAN LAST
NIGHT WITH THE POST FRONTAL WINDS...WITH THE NAM SHOWING A PERIOD OF
50 KTS AT 925 MB...IN A SWELL ALIGNED SW FLOW. EXPECT THIS WILL
BRING ANOTHER ROUND OF GUSTY WINDS TO THE NIAGARA FRONTIER...AND
ALONG THE IMMEDIATE LAKE ERIE SHORELINE. FOR THIS REASON...WILL
EXTEND THE WIND ADVISORY TO CAPTURE POST-FRONTAL WINDS IN THESE
LOCATIONS. THE COLD FRONT MAY BRING SOME ADDITIONAL SHOWERS AS
WELL...WITH THIS LIKELY TO BE MOST ORGANIZED EAST OF LAKE ONTARIO.
WHILE ALL THIS GOES ON...TEMPERATURES HAVE RISEN ABOVE FREEZING IN
MOST LOCATIONS...THOUGH THERE ARE A FEW SPOTS STILL NEAR THE
FREEZING MARK. TEMPERATURES WILL CONTINUE TO RISE SLOWLY THROUGH
MID-MORNING. EXPECT THE PASSAGE OF THE STRONG WINDS ALOFT TO KEY
MIXING...AND A RATHER ABRUPT RISE IN TEMPERATURES INTO THE UPPER 40S
TO LOWER 50S. TEMPERATURES WILL REMAIN QUITE WARM UNTIL THE COLD
FRONT CROSSES THIS EVENING. ANY LINGERING SHOWERS LATE TONIGHT
SHOULD CHANGE OVER TO SNOW SHOWERS. EXPECT THESE TO BE QUITE
WIDESPREAD...WITH NO ACCUMULATION.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
A WEST TO SOUTHWEST FLOW OF COLDER AIR WILL BUILD ACROSS THE AREA
TUESDAY AS LOW PRESSURE TRACKS EAST ACROSS QUEBEC. SYNOPTIC MOISTURE
WRAPPING IN BEHIND THE LOW WILL BRING A CHANCE OF SNOW SHOWERS TO
THE ENTIRE AREA...AND THERE MAY BE A LIMITED RESPONSE FROM THE LAKES
WITH THE NAM NOW SHOWING COLDER AIR (AVERAGING AROUND -12C)
ADVECTING ACROSS THE AREA DURING THE AFTERNOON. THE POTENTIAL FOR
SOME LAKE ENHANCED SNOW LOOKS TO BE GREATER EAST OF LAKE ONTARIO
WHERE THE NAM SHOWS DEEPER MOISTURE...MORE FAVORABLE SNOW GROWTH AND
GREATER LAKE INDUCED INSTABILITY. SNOW ACCUMULATIONS WILL LIKELY
REMAIN UNDER ADVISORY CRITERIA...HOWEVER.
BREEZY TO WINDY CONDITIONS WILL PERSIST ON TUESDAY...ESPECIALLY
DOWNWIND OF THE LAKES WHERE AN ADDITIONAL INFLUENCE FROM FUNNELING
WILL COME INTO PLAY.
AS THE SURFACE LOW HEADS EAST TOWARD THE CANADIAN MARITIMES TUESDAY
NIGHT...A SECONDARY TROUGH WILL DROP SOUTH ACROSS NEW YORK STATE.
WEAK CONVERGENCE ALONG THIS BOUNDARY...COMBINED WITH ADDITIONAL LIFT
FROM A PASSING UPPER LEVEL TROUGH MAY GENERATE A FEW MORE SNOW
SHOWERS DURING THE FIRST HALF OF THE NIGHT...WHILE SOME LAKE
ENHANCED SNOW LINGERS EAST OF LAKE ONTARIO. DURING THE SECOND HALF
OF THE NIGHT...DRIER AIR WILL BE WORKING IN FROM THE WEST AS HIGH
PRESSURE BUILDS EAST TOWARD THE LOWER LAKES. TEMPERATURES ALOFT WILL
ALSO BEGIN TO MODERATE AS THE CORE OF THE COLDEST AIR SHIFTS EAST
INTO NORTHERN NEW ENGLAND WITH THE DEPARTING UPPER LEVEL TROUGH.
THEREAFTER...SURFACE RIDGING WILL BUILD ACROSS THE AREA WEDNESDAY
...BRINGING PROGRESSIVELY DRIER AIR. THIS WILL HELP TO END ANY
UPSLOPE/LAKE-ENHANCED SNOW SHOWERS THAT MAY LINGER EAST OF LAKE
ONTARIO DURING THE MORNING. EXPECT DRY CONDITIONS TO CONTINUE
WEDNESDAY NIGHT AS THE SURFACE HIGH CRESTS OVER NEW YORK AND
PA. SOME INCREASE IN CLOUDS IS LIKELY LATER WEDNESDAY NIGHT AS
MOISTURE BEGINS TO WORK NORTH ALONG AN INVERTED TROUGH THAT IS
FORECAST TO EXTEND NORTH FROM A DEVELOPING LOWER MISSISSIPPI VALLEY
LOW.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AFTER THE SURFACE RIDGE DRIFTS OFF THE EAST COAST WEDNESDAY NIGHT...
THE MEDIUM RANGE MODELS INDICATE THAT A DOUBLE-BARRELED LOW PRESSURE
MAY IMPACT OUR AREA LATE IN THE WORK WEEK. THE VARIOUS GUIDANCE
PACKAGES HAVE STARTED TO COME MORE IN LINE IN THEIR HANDLING OF THIS
SYSTEM WITH THE 12Z/22 CYCLE... WITH THE GFS/GEM GLOBAL AND ECMWF
NOW ALL INDICATING A NORTHERN STREAM WAVE THAT PASSES BY WELL TO OUR
NORTH ACROSS ONTARIO AND QUEBEC THURSDAY INTO FRIDAY...WHILE A MUCH
WEAKER INITIAL SOUTHERN STREAM WAVE PASSES BY WELL TO OUR SOUTH. IN
BETWEEN IS A WEAK CONNECTING TROUGH WITH ONLY VERY MEAGER ASSOCIATED
QPF SUGGESTED BY ALL THREE MODELS...THOUGH I SUSPECT THAT THIS IS
PROBABLY A LITTLE UNDERDONE. ACCORDINGLY...WILL CONTINUE TO CARRY A
ROUND OF BROADBRUSH LOW CHANCE POPS FOR THIS PERIOD...WHILE KEEPING
PTYPE AT LEAST A A RAIN/SNOW MIX OR EVEN JUST PLAIN RAIN GIVEN THE
RATHER MILD NATURE OF OUR AIRMASS.
FOLLOWING THE PASSAGE OF THIS SYSTEM...INCREASING RIDGING/DRYING
SHOULD THEN ONCE AGAIN TAKE HOLD AND BRING A RETURN TO MAINLY DRY
WEATHER FOR LATER FRIDAY AFTERNOON AND/OR FRIDAY NIGHT. AFTER
THAT...THE GFS/ECMWF BOTH SUGGEST THAT INCREASING LARGE-SCALE
TROUGHING WILL BRIEFLY DIG SOUTHEAST INTO THE GREAT LAKES AND
NORTHEAST NEXT WEEKEND. AT THE SURFACE...THIS WILL BE REFLECTED BY
THE PASSAGE OF YET ANOTHER COMPLEX AREA OF LOW PRESSURE...WITH A
POTENTIALLY MORE SIGNIFICANT SOUTHERN STREAM WAVE LARGELY MISSING
OUR AREA TO THE SOUTHEAST...WHILE A NORTHERN STREAM CLIPPER-TYPE
SYSTEM WORKS ACROSS OUR AREA...FOLLOWED BY A BRIEF SHOT OF
SEASONABLY COLDER CANADIAN AIR AND POSSIBLE LAKE EFFECT FOR SATURDAY
NIGHT AND SUNDAY. WILL COVER ALL OF THIS WITH ANOTHER ROUND OF
CHANCE POPS...WHILE BRINGING TEMPERATURES BACK TO SLIGHTLY BELOW
NORMAL LEVELS BY THE END OF THE PERIOD.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A DEEP BUT MATURE CYCLONE FOUND OVER MISSOURI AT 04Z WILL LIFT UP
ACROSS THE UPPER GREAT LAKES ON MONDAY. THIS WILL BRING SOME VERY
ACTIVE WEATHER TO WESTERN AND NORTH CENTRAL NEW YORK IN THE
PROCESS...AS OUR REGION WILL INITIALLY EXPERIENCE LOW LEVEL WIND
SHEAR ISSUES BUT THAT WILL BE FOLLOWED BY GUSTY SURFACE WINDS AND
THERE WILL EVEN BE THE THREAT FOR SOME CONVECTION.
FOR THE REST OF THE OVERNIGHT THOUGH...THE MAIN CONCERN WILL BE THE
AFOREMENTIONED WIND SHEAR. LOW LEVEL WIND SHEAR WILL INCREASE
OVERNIGHT AND MONDAY WITH A STRONG 60-65 KNOT LOW LEVEL JET
PROPAGATING ACROSS THE REGION. THE STRONG WINDS ALOFT WILL EXTEND
DOWN VERY CLOSE TO THE SURFACE...JUST 1000-1500 FEET UP. THAT
COMBINED WITH A 5 TO 8 DEG C LOW LEVEL INVERSION WILL CREATE RAPID
CHANGES IN WIND SPEED AND DIRECTION OVER A SHORT VERTICAL DISTANCE
ON FINAL APPROACHES AND DEPARTURES. AS MENTIONED...LOW LEVEL WIND
SHEAR WILL LIKELY BE AN ISSUE THROUGH MONDAY.
OF LESSER CONCERN OVERNIGHT WILL BE SOME MVFR CIGS THAT WILL BE
SQUEEZING IN ON THE WESTERN COUNTIES. WHILE CIGS WILL LARGELY BE VFR
OVERNIGHT...MVFR CIGS WILL BE POSSIBLE AS THE NIGHT PROGRESSES WITH
SOME IFR CIGS ACROSS PARTS OF THE SRN TIER.
ON MONDAY...THINGS WILL BECOME EVEN MORE INTERESTING AS A PRE
FRONTAL TROUGH WILL CROSS THE REGION DURING THE MORNING AND MIDDAY.
THERE WILL BE THE CHANCE FOR SOME BROKEN CONVECTION WITH THIS
TROUGH...SO HAVE INCLUDED THE MENTION OF CB`S IN THE FAR WRN TAFS.
CIGS WILL ALSO DROP TO MVFR LEVELS WITH THE PASSAGE OF THIS
TROUGH...THEN A BRIEF PERIOD OF VFR CIGS ARE EXPECTED AHEAD OF THE
MAIN COLD FRONT. THIS FRONT WILL PASS EARLY IN THE EVENING.
CIGS IN THE WAKE OF THIS FRONT WILL DROP TO BETWEEN 1500 AND 2500
FEET FOR THE EVENING HOURS...THEN TO IFR LEVELS OVERNIGHT.
OUTLOOK...
TUESDAY...AREAS OF MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR.
THURSDAY AND FRIDAY...MAINLY VFR WITH A CHANCE OF RAIN/SNOW SHOWERS.
&&
.MARINE...
EXPECT GUSTY SOUTHERLY WINDS TODAY...WITH SMALL CRAFT ADVISORIES IN
PLACE ACROSS THE REGION. THIS STILL LOOKS ON TRACK...WITH BRIEFLY
HIGHER GUSTS POSSIBLE AS A LINE OF SHOWERS AND THUNDERSTORMS MOVES
ACROSS LAKE ERIE MID AND LATE MORNING...AND ACROSS LAKE ONTARIO LATE
MORNING THROUGH THIS AFTERNOON. BRIEF PERIODS OF GUSTY WINDS TO GALE
FORCE ARE POSSIBLE IN THUNDERSTORMS.
A COLD FRONT WILL CROSS THE WATERS THIS EVENING...SHIFTING WINDS TO
THE SW. EXPECT NEAR GALE CONDITIONS ON LAKE ERIE LATE EVENING AND
OVERNIGHT...AS 925 MB WINDS INCREASE TO 50 KTS. SURFACE TEMPERATURES
BEHIND THE FRONT ARE NOT THAT COLD...WHICH WILL SOMEWHAT LIMIT
MIXING. THIS SAID...IT IS POSSIBLE THAT THE ADVISORY WILL NEED TO BE
UPGRADED TO GALES ON LAKE ERIE TONIGHT.
AFTER THIS...WINDS WILL GRADUALLY SHIFT TO THE WEST BEHIND THE
FRONT...WITH A FAIRLY PROLONGED PERIOD OF SMALL CRAFT ADVISORY CONDITIONS
EXPECTED TO LAST INTO WEDNESDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WIND ADVISORY FROM 9 AM THIS MORNING TO 7 PM EST THIS EVENING
FOR NYZ007-008.
WIND ADVISORY FROM 9 AM THIS MORNING TO 4 AM EST TUESDAY FOR
NYZ001>003-010-011.
WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NYZ012>014-020-
021.
WIND ADVISORY UNTIL 4 AM EST TUESDAY FOR NYZ019-085.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 PM EST
TUESDAY FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR LEZ040-
041.
SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 PM
EST TUESDAY FOR LOZ030.
SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR
LOZ043>045.
SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 5 AM EST
WEDNESDAY FOR LOZ042.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...TJP
LONG TERM...JJR
AVIATION...RSH
MARINE...APFFEL
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
240 AM EST MON JAN 23 2012
.SYNOPSIS...
LOW PRESSURE OVER THE WESTERN GREAT LAKES WILL PUSH A COLD FRONT
INTO THE AREA LATE MONDAY. AHEAD OF THE FRONT...MILDER AIR
WILL ARRIVE AND BRING LIGHT RAIN AND DRIZZLE. SURFACES TONIGHT AND
EARLY MONDAY WILL LIKELY BE BELOW FREEZING SO SOME ICING IS
LIKELY. COOLER AND DRIER AIR WILL COME IN BEHIND THE FRONT MONDAY
NIGHT AND TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1030 PM UPDATE...
STILL SEEING SOME VERY LIGHT RETURNS ON RADAR AND THESE CONTINUE
TO BE CONFIRMED AS JUST SNOW FLURRIES PER THE SUSQUEHANNA COUNTY
911 CENTER...AND OBS HERE AT THE NWS OFFICE...SCRANTON...AND MOUNT
POCONO. LOOKING AT RUC MODEL SOUNDINGS...ON FIRST GLANCE IT LOOKS
LIKE A CLASSIC DRIZZLE SOUNDING WITH DRY AIR IN THE MID AND UPPER
LEVELS (NO ICE CRYSTALS). HOWEVER WE HAVE MOISTURE NEAR THE
SURFACE IN THE LOWEST FEW THOUSAND FEET AND WE ARE JUST COLD
ENOUGH (-5C) TO PRODUCE SOME ICE CRYSTALS FOR FLURRIES. AFTER 06Z
WE SHOULD WARM ENOUGH JUST ABOVE THE SURFACE TO CHANGE ANY PRECIP
OVER TO DRIZZLE. WITH SURFACE TEMPS BELOW FREEZING THROUGH
DAYBREAK...AREAS OF FREEZING DRIZZLE IN THE CURRENT FREEZING RAIN
ADVISORY AREA LOOKS ON TRACK. HIGHEST PROBABILITY FOR SOME LIGHT
ICE ACCUMS WILL BE ACROSS THE HIGHER TERRAIN OF NEPA AND THE
WESTERN CATSKILLS. BASED ON LAV GUIDANCE SHOWING KAVP NEAR
FREEZING THROUGH 13Z AND MONTICELLO THROUGH 15Z...EXTENDED THE END
TIME FROM 8 AM TO 11 AM.
ONE LAST THING...OUTSIDE OF THE ADVISORY AREA I STILL THINK THAT
SOME PATCHY FREEZING DRIZZLE IS POSSIBLE ACROSS
CHEMUNG...TIOGA...BROOME...AND SOUTHERN CHENANGO
COUNTIES...ESPECIALLY THE HIGHER UP IN ELEVATION YOU LIVE. CHOSE NOT
TO EXPAND THE ADVISORY BECAUSE THE SOUTHEAST FLOW MAY BE JUST
ENOUGH OF A DOWN SLOPING FACTOR TO LIMIT THE IMPACT OF ANY
FREEZING DRIZZLE. THE OVERNIGHT SHIFT WILL HAVE TO MONITOR THE
RADAR TRENDS JUST TO BE SAFE. THE PREVIOUS AFD IS BELOW...
7 PM UPDATE...AN INTERESTING DEVELOPMENT OVER THE LAST
HOUR OR SO AS THE KBGM RADAR HAS SHOWN SOME VERY LIGHT RETURNS
OVER NORTHERN PA SNEAKING INTO THE SOUTHERN TIER OF NY. THIS IS
CONFIRMED BY WILLIAMSPORT REPORTING VERY LIGHT SNOW AT LAST OB.
OUR HIGHLY SENSITIVE WEB CAM AT THE OFFICE IS SHOWING VERY LIGHT
AND BRIEF PRECIPITATION...BUT WHEN YOU STEP OUTSIDE YOU HAVE TO
STARE AT THE PARKING LOT LIGHTS FOR AT LEAST A MINUTE BEFORE YOU
SEE ANYTHING. WE MAY BE SEEING A FEW FLURRIES ATTM (RUC SOUNDINGS
SHOWING -5C IN THE MOIST LAYER)...BUT IF TRENDS CONTINUE TO
INCREASE AND IT BECOMES MORE APPARENT THAT IT IS FREEING DRIZZLE
THE ADVISORY IN PLACE MAY HAVE TO BE EXPANDED NORTHWEST. FOR NOW
WILL HOLD WITH THE GOING FORECAST AND WILL MONITOR TRENDS TO SEE
IF THIS VERY FINE DRIZZLE OR AREA OF FLURRIES PICKS UP IN
INTENSITY BECAUSE RIGHT NOW IT IS JUST TOO LIGHT TO HAVE AN
IMPACT. THE PREVIOUS AFD IS BELOW...
MARINE LYR HAS SLOWLY BEEN CREEPING NWRD THIS MRNG. ADVANCE
SHD ACCELERATE THIS EVE WITH THE LOSS OF THE SUN AND TIGHTENING OF
THE GRADIENT AHD OF THE LOW. THIS SHALLOW LYR WILL BE THE MOISTURE
SOURCE FOR ANY FREEZING RAIN AND DRIZZLE OVERNIGHT AS MOISTURE AHD
OF THE FNT IS STILL SVRL HRS AWAY. MODELS CONT TO BE VERY LGT WITH
THE QPF...REALLY JUST A FEW HUNDREDTHS AT MOST. CRNT AREA OF THE
ADVISORY DOES SHOW THE BEST AREA WELL SO WILL LEAVE AS IS EVEN
THOUGH IT LOOKS LIKE ICING WILL BE VERY LGT. TEMPS HAVE REALLY
STRUGGLED TO RISE DESPITE THE HAZY SUN...ALONG WITH DEW PTS STILL
IN THE TEENS AND EVEN SINGLE NUMBERS. THERE/S PTNL FOR THE TEMPS
TO DROP A FEW HRS AFT DARK...ESP OVER THE WRN CATS. NAM CONTS TO
SHOW A GOOD DAMMING SIGNITURE...SO...ANY PCPN THAT DOES FALL WILL
CERTAINLY FREEZE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
FAST MVG OCCLUSION PASSES THRU MON ARND 18Z WITH SHWRS AND GUSTY
WINDS...ALTHOUGH DEEP INV SHD HELP KEEP THE HIGHEST WINDS ABV THE
SFC...SO NO WIND FLAGS NEEDED. CAA DOES NOT REALLY BEGIN UNTIL
LTR MON NGT AND WITH THE MODIFIED AIR...POST FNTL TEMPS STILL ABV
NRML ON TUE. SW FLOW WILL ALSO KEEP ANY WEAK LE CONFINED TO THE
XTRM NORTH...IF AT ALL. SO...MUCH OF THE FCST AREA WILL ENJOY ABV
NRML TEMPS WITH GUSTY WINDS INTO TUE.
UPR TROF AXIS PASSES EARLY WED WHICH WILL BE FLWD BY BRIEF RISING
HGTS AND MILDER AIR ON WED. ANOTHER WEAK WV APRCHS LATE IN THE
PD...BUT WITH LTL IF ANY PCPN.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
230 AM MON UPDATE... NO SIG CHANGES MADE TO THE CURRENT EXTENDED
GRIDS...AS THE INCOMING 00Z MON GUIDANCE IS CONSISTENT...FOR THE
MOST PART...FROM ITS PREVIOUS RUNS.
THE BIGGEST UNCERTAINTY REMAINS WITH THE SRN STREAM LOW OVER TX LATER
THIS WEEK...AND HOW THIS SYSTEM EVOLVES TWDS NEXT WEEKEND. AS
MENTIONED BELOW IN THE PREV DISC...MODEL DISCREPANCY CONTS WITH
THIS PATN. THE EC CONTINUES TO BE THE MOST AGGRESSIVE...BRINGING
PCPN (LIKELY SOME KIND OF MIXED PTYPES...GIVEN THE INITIAL LACK OF
MUCH COLD AIR) FARTHER NWD...WHILE THE GFS IS MORE SUPPRESSED/PROGRESSIVE.
BOTH MODELS WOULD SUGGEST A TREND TWDS COLDER WX BY NEXT
SUN/MON...WITH THE GFS BEING THE COLDEST SOLUTION.
AGAIN...GIVEN LACK OF CONFIDENCE FROM ABT FRI ONWARD...WE SIMPLY
STUCK WITH CONTINUITY/PREV SET OF GRIDS.
PREV DISC... MODELS ARE IN FAIR AGREEMENT WITH MEDIUM RANGE WHICH
INCLUDES TWO NORTHERN STREAM SFC TROFS AND A FAIRLY SIGNIFICANT
SOUTHERN STREAM SYSTEM PASSING TO OUR SOUTH. OVERALL TEMPS WILL
RANGE 5 TO 10 DEGREES ABOVE NORMAL AS WE RESIDE IN THE
CLIMATOLOGICAL COLDEST PERIOD OF THE WINTER SEASON.
WEDNESDAY NIGHT WILL BE DRY WITH SFC HIGH PRES IN THE AREA.
ON THURSDAY, SFC LOW PRES IN THE UPPER GREAT LAKES MAY PRODUCE
SOME MIXED WINTRY PRECIP DURING THE MORNING BEFORE TEMPS WARM
ENOUGH FOR JUST PLAIN RAIN. SYSTEM IS NOT VERY STRONG WITH
LIMITED MOISTURE THEREFORE JUST LOW CHC POPS. THURSDAY NIGHT THE
TRAILING COLD FRONT WILL PUSH THROUGH WITH CHC POPS FOR MIXED
RAIN/SNOW SHOWERS CHANGING TO ALL SNOW SHOWERS. ON FRIDAY SOME
LINGERING POST FRONTAL SNOW SHOWERS ARE POSSIBLE DURING THE
MORNING OTHERWISE DRY.
FRIDAY NIGHT THROUGH SATURDAY, A SOUTHERN STREAM LOW PRES SYSTEM
LIFTS FROM THE GULF STATES INTO THE MID ATLANTIC REGION THEN OFF
THE COAST. THE ECMWF BRINGS THIS FEATURE FURTHER NORTH SPREADING
PRECIP ACROSS THE ENTIRE CWA WHILE THE GFS IS MUCH FURTHER SOUTH
WITH NO IMPACT HERE. WILL FOLLOW HPC GUIDANCE WHICH HAS CHC POPS
NE PA FRIDAY NIGHT THEN CHC POPS ENTIRE FA ON SATURDAY. FOR NOW
THE COLUMN LOOKS COLD ENOUGH FOR PRIMARILY ALL SNOW, BUT THERE
COULD BE A RAIN/SNOW MIX SATURDAY MIDDAY OVER FAR SOUTHERN FA.
BEHIND THIS SYSTEM A NORTHERN STREAM SFC TROF WILL PASS THROUGH
THE REGION SATURDAY NIGHT WITH CHC POPS FOR SNOW SHOWERS. ON
SUNDAY A COLDER AIRMASS ALONG WITH WESTERLY FLOW WILL CONTINUE CHC
POPS FOR SNOW SHOWERS ESPECIALLY NRN CWA.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
UPDATED AS OF 1250 AM MON... LOWER CIGS HAVE OVERSPREAD NE PA AND
MOST OF CNY ATTM...AND SHOULD PERSIST THROUGHOUT THE VALID TAF PD.
THUS...LOOK FOR MVFR RESTRICTIONS TO BE PREVALENT. AT KBGM AND
KITH...IFR CIGS COULD OCCASIONALLY SNEAK IN EARLY THIS MRNG.
PATCHY DZ/FZDZ IS LIKELY OVER THE HILLS TO THE E AND SE OF KAVP
AND KBGM THIS MRNG...BUT WE DON`T EXPECT THIS ACTIVITY TO PRESENT
MUCH OF AN IMPACT AT THE TERMINAL SITES THEMSELVES.
A RELATIVELY BRIEF PD OF STEADY RAIN IS ANTICIPATED LATER THIS
AFTN INTO THE EARLY EVE (GENERALLY 21-03Z). ONCE AGN...KBGM/KITH
WILL BE THE MOST LIKELY CANDIDATES FOR PERIODIC IFR.
PERHAPS THE MOST SIG AVIATION ISSUE TODAY WILL BE LLWS. SE WINDS
NEAR THE SFC GENERALLY 5-15 KT...WILL BE TOPPED BY VERY STG FLOW
OF 45-60 KT FROM THE SW...JUST ABV THE SFC LYR (BASICALLY
1500-2500 FT AGL). THESE SHEAR CONDS ARE VERY LIKELY TO PERSIST A
GOOD PTN OF THE DAY...LIKELY NOT ABATING TIL LATER IN THE AFTN (18-21Z).
.OUTLOOK...
TUE/WED...PATCHY MVFR CNTRL NY...MAINLY VFR NE PA.
THU/FRI...MVFR IN RAIN/SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR
PAZ038>040-043-044-047-048-072.
NY...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ057-
062.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/HEDEN
SHORT TERM...DGM
LONG TERM...MLJ/RRM
AVIATION...HEDEN/MLJ
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1258 AM EST MON JAN 23 2012
.SYNOPSIS...
LOW PRESSURE OVER THE WESTERN GREAT LAKES WILL PUSH A COLD FRONT
INTO THE AREA LATE MONDAY. AHEAD OF THE FRONT...MILDER AIR
WILL ARRIVE AND BRING LIGHT RAIN AND DRIZZLE. SURFACES TONIGHT AND
EARLY MONDAY WILL LIKELY BE BELOW FREEZING SO SOME ICING IS
LIKELY. COOLER AND DRIER AIR WILL COME IN BEHIND THE FRONT MONDAY
NIGHT AND TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1030 PM UPDATE...
STILL SEEING SOME VERY LIGHT RETURNS ON RADAR AND THESE CONTINUE
TO BE CONFIRMED AS JUST SNOW FLURRIES PER THE SUSQUEHANNA COUNTY
911 CENTER...AND OBS HERE AT THE NWS OFFICE...SCRANTON...AND MOUNT
POCONO. LOOKING AT RUC MODEL SOUNDINGS...ON FIRST GLANCE IT LOOKS
LIKE A CLASSIC DRIZZLE SOUNDING WITH DRY AIR IN THE MID AND UPPER
LEVELS (NO ICE CRYSTALS). HOWEVER WE HAVE MOISTURE NEAR THE
SURFACE IN THE LOWEST FEW THOUSAND FEET AND WE ARE JUST COLD
ENOUGH (-5C) TO PRODUCE SOME ICE CRYSTALS FOR FLURRIES. AFTER 06Z
WE SHOULD WARM ENOUGH JUST ABOVE THE SURFACE TO CHANGE ANY PRECIP
OVER TO DRIZZLE. WITH SURFACE TEMPS BELOW FREEZING THROUGH
DAYBREAK...AREAS OF FREEZING DRIZZLE IN THE CURRENT FREEZING RAIN
ADVISORY AREA LOOKS ON TRACK. HIGHEST PROBABILITY FOR SOME LIGHT
ICE ACCUMS WILL BE ACROSS THE HIGHER TERRAIN OF NEPA AND THE
WESTERN CATSKILLS. BASED ON LAV GUIDANCE SHOWING KAVP NEAR
FREEZING THROUGH 13Z AND MONTICELLO THROUGH 15Z...EXTENDED THE END
TIME FROM 8 AM TO 11 AM.
ONE LAST THING...OUTSIDE OF THE ADVISORY AREA I STILL THINK THAT
SOME PATCHY FREEZING DRIZZLE IS POSSIBLE ACROSS
CHEMUNG...TIOGA...BROOME...AND SOUTHERN CHENANGO
COUNTIES...ESPECIALLY THE HIGHER UP IN ELEVATION YOU LIVE. CHOSE NOT
TO EXPAND THE ADVISORY BECAUSE THE SOUTHEAST FLOW MAY BE JUST
ENOUGH OF A DOWN SLOPING FACTOR TO LIMIT THE IMPACT OF ANY
FREEZING DRIZZLE. THE OVERNIGHT SHIFT WILL HAVE TO MONITOR THE
RADAR TRENDS JUST TO BE SAFE. THE PREVIOUS AFD IS BELOW...
7 PM UPDATE...AN INTERESTING DEVELOPMENT OVER THE LAST
HOUR OR SO AS THE KBGM RADAR HAS SHOWN SOME VERY LIGHT RETURNS
OVER NORTHERN PA SNEAKING INTO THE SOUTHERN TIER OF NY. THIS IS
CONFIRMED BY WILLIAMSPORT REPORTING VERY LIGHT SNOW AT LAST OB.
OUR HIGHLY SENSITIVE WEB CAM AT THE OFFICE IS SHOWING VERY LIGHT
AND BRIEF PRECIPITATION...BUT WHEN YOU STEP OUTSIDE YOU HAVE TO
STARE AT THE PARKING LOT LIGHTS FOR AT LEAST A MINUTE BEFORE YOU
SEE ANYTHING. WE MAY BE SEEING A FEW FLURRIES ATTM (RUC SOUNDINGS
SHOWING -5C IN THE MOIST LAYER)...BUT IF TRENDS CONTINUE TO
INCREASE AND IT BECOMES MORE APPARENT THAT IT IS FREEING DRIZZLE
THE ADVISORY IN PLACE MAY HAVE TO BE EXPANDED NORTHWEST. FOR NOW
WILL HOLD WITH THE GOING FORECAST AND WILL MONITOR TRENDS TO SEE
IF THIS VERY FINE DRIZZLE OR AREA OF FLURRIES PICKS UP IN
INTENSITY BECAUSE RIGHT NOW IT IS JUST TOO LIGHT TO HAVE AN
IMPACT. THE PREVIOUS AFD IS BELOW...
MARINE LYR HAS SLOWLY BEEN CREEPING NWRD THIS MRNG. ADVANCE
SHD ACCELERATE THIS EVE WITH THE LOSS OF THE SUN AND TIGHTENING OF
THE GRADIENT AHD OF THE LOW. THIS SHALLOW LYR WILL BE THE MOISTURE
SOURCE FOR ANY FREEZING RAIN AND DRIZZLE OVERNIGHT AS MOISTURE AHD
OF THE FNT IS STILL SVRL HRS AWAY. MODELS CONT TO BE VERY LGT WITH
THE QPF...REALLY JUST A FEW HUNDREDTHS AT MOST. CRNT AREA OF THE
ADVISORY DOES SHOW THE BEST AREA WELL SO WILL LEAVE AS IS EVEN
THOUGH IT LOOKS LIKE ICING WILL BE VERY LGT. TEMPS HAVE REALLY
STRUGGLED TO RISE DESPITE THE HAZY SUN...ALONG WITH DEW PTS STILL
IN THE TEENS AND EVEN SINGLE NUMBERS. THERE/S PTNL FOR THE TEMPS
TO DROP A FEW HRS AFT DARK...ESP OVER THE WRN CATS. NAM CONTS TO
SHOW A GOOD DAMMING SIGNITURE...SO...ANY PCPN THAT DOES FALL WILL
CERTAINLY FREEZE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
FAST MVG OCCLUSION PASSES THRU MON ARND 18Z WITH SHWRS AND GUSTY
WINDS...ALTHOUGH DEEP INV SHD HELP KEEP THE HIGHEST WINDS ABV THE
SFC...SO NO WIND FLAGS NEEDED. CAA DOES NOT REALLY BEGIN UNTIL
LTR MON NGT AND WITH THE MODIFIED AIR...POST FNTL TEMPS STILL ABV
NRML ON TUE. SW FLOW WILL ALSO KEEP ANY WEAK LE CONFINED TO THE
XTRM NORTH...IF AT ALL. SO...MUCH OF THE FCST AREA WILL ENJOY ABV
NRML TEMPS WITH GUSTY WINDS INTO TUE.
UPR TROF AXIS PASSES EARLY WED WHICH WILL BE FLWD BY BRIEF RISING
HGTS AND MILDER AIR ON WED. ANOTHER WEAK WV APRCHS LATE IN THE
PD...BUT WITH LTL IF ANY PCPN.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MODELS ARE IN FAIR AGREEMENT WITH MEDIUM RANGE WHICH INCLUDES TWO
NORTHERN STREAM SFC TROFS AND A FAIRLY SIGNIFICANT SOUTHERN
STREAM SYSTEM THAT PASSING TO OUR SOUTH. OVERALL TEMPS WILL RANGE
5 TO 10 DEGREES ABOVE NORMAL AS WE RESIDE IN THE CLIMATOLOGICAL
COLDEST PERIOD OF THE WINTER SEASON.
WEDNESDAY NIGHT WILL BE DRY WITH SFC HIGH PRES IN THE AREA.
ON THURSDAY, SFC LOW PRES IN THE UPPER GREAT LAKES MAY PRODUCE
SOME MIXED WINTRY PRECIP DURING THE MORNING BEFORE TEMPS WARM
ENOUGH FOR JUST PLAIN RAIN. SYSTEM IS NOT VERY STRONG WITH
LIMITED MOISTURE THEREFORE JUST LOW CHC POPS. THURSDAY NIGHT THE
TRAILING COLD FRONT WILL PUSH THROUGH WITH CHC POPS FOR MIXED
RAIN/SNOW SHOWERS CHANGING TO ALL SNOW SHOWERS. ON FRIDAY SOME
LINGERING POST FRONTAL SNOW SHOWERS ARE POSSIBLE DURING THE
MORNING OTHERWISE DRY.
FRIDAY NIGHT THROUGH SATURDAY, A SOUTHERN STREAM LOW PRES SYSTEM
LIFTS FROM THE GULF STATES INTO THE MID ATLANTIC REGION THEN OFF
THE COAST. THE ECMWF BRINGS THIS FEATURE FURTHER NORTH SPREADING
PRECIP ACROSS THE ENTIRE CWA WHILE THE GFS IS MUCH FURTHER SOUTH
WITH NO IMPACT HERE. WILL FOLLOW HPC GUIDANCE WHICH HAS CHC POPS
NE PA FRIDAY NIGHT THEN CHC POPS ENTIRE FA ON SATURDAY. FOR NOW
THE COLUMN LOOKS COLD ENOUGH FOR PRIMARILY ALL SNOW, BUT THERE
COULD BE A RAIN/SNOW MIX SATURDAY MIDDAY OVER FAR SOUTHERN FA.
BEHIND THIS SYSTEM A NORTHERN STREAM SFC TROF WILL PASS THROUGH
THE REGION SATURDAY NIGHT WITH CHC POPS FOR SNOW SHOWERS. ON
SUNDAY A COLDER AIRMASS ALONG WITH WESTERLY FLOW WILL CONTINUE CHC
POPS FOR SNOW SHOWERS ESPECIALLY NRN CWA.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
UPDATED AS OF 1250 AM MON... LOWER CIGS HAVE OVERSPREAD NE PA AND
MOST OF CNY ATTM...AND SHOULD PERSIST THROUGHOUT THE VALID TAF PD.
THUS...LOOK FOR MVFR RESTRICTIONS TO BE PREVALENT. AT KBGM AND
KITH...IFR CIGS COULD OCCASIONALLY SNEAK IN EARLY THIS MRNG.
PATCHY DZ/FZDZ IS LIKELY OVER THE HILLS TO THE E AND SE OF KAVP
AND KBGM THIS MRNG...BUT WE DON`T EXPECT THIS ACTIVITY TO PRESENT
MUCH OF AN IMPACT AT THE TERMINAL SITES THEMSELVES.
A RELATIVELY BRIEF PD OF STEADY RAIN IS ANTICIPATED LATER THIS
AFTN INTO THE EARLY EVE (GENERALLY 21-03Z). ONCE AGN...KBGM/KITH
WILL BE THE MOST LIKELY CANDIDATES FOR PERIODIC IFR.
PERHAPS THE MOST SIG AVIATION ISSUE TODAY WILL BE LLWS. SE WINDS
NEAR THE SFC GENERALLY 5-15 KT...WILL BE TOPPED BY VERY STG FLOW
OF 45-60 KT FROM THE SW...JUST ABV THE SFC LYR (BASICALLY
1500-2500 FT AGL). THESE SHEAR CONDS ARE VERY LIKELY TO PERSIST A
GOOD PTN OF THE DAY...LIKELY NOT ABATING TIL LATER IN THE AFTN (18-21Z).
.OUTLOOK...
TUE/WED...PATCHY MVFR CNTRL NY...MAINLY VFR NE PA.
THU/FRI...MVFR IN RAIN/SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR
PAZ038>040-043-044-047-048-072.
NY...FREEZING RAIN ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ057-
062.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/HEDEN
SHORT TERM...DGM
LONG TERM...RRM
AVIATION...HEDEN/MLJ
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
901 PM CST TUE JAN 24 2012
.DISCUSSION...
AREA OF SNOW WHICH BRUSHED FAR SE ND NOW INTO WEST CENTRAL MN WITH
-SN AT ELBOW LAKE AND FOR A BRIEF TIME AS FAR NORTH AS FERGUS
FALLS. AREA SHIFTING EAST SLOWLY AND SHOULD EXIT FCST AREA BY 06Z.
MAIN CONCERN OVERNIGHT IS CLOUD COVER IN THAT FAR SE ND INTO
WCNTRL MN REGION.
WATER VAPOR SHOWS TWO MAIN VORTS. ONE IN EASTERN MANITOBA MOVING
INTO NW ONTARIO AND THERE HAS BEEN FAST CLEARING OF THE HIGH-MID
LEVEL CLOUDS EASTWARD THIS EVENING WITH CLEARING LINE REACHING A
BDE-TVF-CKN LINE AT 0230Z. SRN EDGE IS SLOWER TO CLEAR OUT AS
SECOND VORT MAX NOW IN WRN NEBRASKA MOVES EAST...WITH CLOUD-
CLEARING LINE RUNNING FROM CKN TO JUST WEST OF FARGO TO ABOUT
ELLENDALE ND. AREA OF LOW CLDS AND SOME FOG FORMING IN SOUTH
DAKOTA WEST OF ABERDEEN IN THE MISSOURI RIVER VALLEY...AND SOME
CONCERN THAT NRN EDGE OF SOME STRATUS WILL INDEED MOVE OR DEVELOP
NORTHWARD INTO FAR SE ND AND WCNTRL MN AND STAY THERE THROUGH THE
EARLY MORNING. ALREADY SEEING SOME IDEAS OF THIS AT GWINNER AWOS
AND WHAPETON AWOS. THUS BUMPED UP SKY COVER AND LOWS TO ACCOUNT
FOR THIS IDEA. LATEST HRRR INDICATES NRN EDGE OF SOME LOWER CLOUDS
MAY REACH FARGO OVERNIGHT.
.AVIATION...
VFR OVERNIGHT INTO WEDNDESDAY MORNING. NOT OUT OF THE QUESTION
SOME PATCHY GROUND FORMS IN CLEAR AREA DUE TO LIGHT SOUTHERLY
WINDS. MAIN ISSUE IS FARGO AREA AS SOME POTENTIAL FOR LOW END MVFR
OR EVEN IFR CIGS TO SPREAD NORTH INTO FARGO AREA OVERNIGHT INTO
EARLY WED AM. CONFIDENCE IS LOW THOUGH. WILL BE ABLE TO SEE BETTER
ONCE HIGH CLOUDS EXIT. WINDS WILL PICK UP FROM THE SOUTH TO SOUTH-
SOUTHWEST WEDNESDAY BY LATE MORNING WITH GUSTS TO 25 KTS AT
TIMES.
&&
.PREV DISCUSSION... /ISSUED 256 PM CST TUE JAN 24 2012/
SHORT TERM...
PRECIP CHANCES AND TYPE WILL BE THE PRIMARY FORECAST PROBLEM FOR
THE PERIOD.
WV LOOP AND UPPER AIR OBS SHOW THE TROUGH OVER THE ROCKIES
STARTING TO SPLIT WITH THE NORTHERN BRANCH SHORTWAVE ENTERING ND.
THIS SHORTWAVE SHOULD MOVE QUICKLY OFF TO THE EAST TONIGHT. THE
SFC TROUGH OVER SOUTHERN CANADA SHOULD DEEPEN AND SOUTHWEST WINDS
WILL INCREASE TOWARDS MORNING. RADAR SHOWS A DECENT PRECIP BAND
ALONG THE 700MB BAROCLINIC ZONE IN SD THIS AFTERNOON. THE MODELS
BRING THE EDGE OF THE BEST 700MB FRONTOGENESIS INTO OUR FAR
SOUTHERN COUNTIES. OBS HAVE NOT SHOW MUCH REACHING THE
GROUND...BUT THE BAND HAS BEEN PRETTY NARROW AND IS MISSING QUITE
A FEW AUTOMATED SITES. CURRENTLY HAVE JUST A FLURRY MENTION IN OUR
FAR SOUTH...BUT WILL TAKE ONE LAST LOOK AT WEBCAMS BEFORE SENDING
OUT THE FORECAST AND MAY UPGRADE TO 20 POPS THIS EVENING.
WARM AIR ADVECTION WILL CONTINUE THROUGH TONIGHT AND SHOULD HELP
KEEP THE WESTERN COUNTIES IN THE TEENS OVERNIGHT. THE NEXT WEAK
SHORTWAVE TROUGH WILL TRACK ALONG THE INTERNATIONAL BORDER
TOMORROW. THE MAIN SFC TROUGH AXIS WILL MOVE INTO THE CWA WITH THE
THERMAL RIDGE AT 850MB OVER THE SOUTHERN CWA BY 00Z. MODELS ARE
ALL OVER THE PLACE AS FAR AS BREAKING PRECIP OUT ALONG THE TROUGH
AXIS. THE 12Z NAM WAS COMPLETELY DRY...WHILE THE 18Z IS SHOWING A
SMALL AMOUNT TOMORROW AFTERNOON IN THE FAR WEST. THE GFS HAS SOME
PRECIP ACROSS A LARGER PORTION OF THE CWA...BUT VERY LIGHT QPF.
THE ECMWF IS THE MOST BULLISH ON PRECIP AT THIS POINT. GIVEN THE
WEAK SYSTEM AND UNCERTAINTY...WILL KEEP POPS AROUND 30 PERCENT.
MODEL SOUNDINGS CONTINUE TO SHOW A FAIRLY WARM LAYER
ALOFT...ALTHOUGH THERE IS SOME VARIATION AS TO HOW WARM THE SFC
WILL BE AND IF WE GET COMPLETELY SATURATED. WILL CONTINUE TO KEEP
A RA/FZRA MENTION FOR WEDNESDAY AFTERNOON EVENTUALLY TRANSITIONING
TO SNOW OVERNIGHT AS COLD AIR COMES DOWN BEHIND THE SHORTWAVE
DIGGING INTO MN.
NORTHWESTERLY FLOW ALOFT WILL SET UP FOR THURSDAY AND THURSDAY
NIGHT. THE SFC HIGH WILL BE CENTERED TO OUR SOUTH AND WEST....WITH
LOW PRESSURE TO THE NORTHEAST OVER ONTARIO. THE PREVAILING SFC
WINDS WILL BE FROM THE WEST...AND WITH DECREASING CLOUDS WE SHOULD
SEE TEMPS CONTINUED ABOVE AVERAGE FOR THIS TIME OF YEAR FOR
THURSDAY AND FRIDAY. ANOTHER WEAK SHORTWAVE WILL DIG DOWN INTO THE
REGION ON THURSDAY NIGHT AND FRIDAY. THE NAM CONTINUES TO BE THE
DRIEST MODEL...BUT THE GFS AND ECMWF SHOW SOME DECENT PRECIP
COMING OUT WITH THE SHORTWAVE. ENSEMBLES SHOW SOME SMALL
PROBABILITIES OF MORE THAN 0.05 INCHES OF QPF...SO WILL INCLUDE
SOME 30 POPS FOR FRIDAY FOR THE TIME BEING. WITH CLOUDS AND PRECIP
THINK THAT TEMPS WILL BE SLIGHTLY COOLER IN THE 20S TO AROUND 30 AND
PRECIP TYPE SHOULD BE ALL SNOW.
LONG TERM... /FRI NIGHT THROUGH TUE/
NORTHWEST FLOW UPPER LEVEL PATTERN WILL SET UP SERIES OF WEAK WAVES
PROPAGATING THROUGH AREA. MODELS...HOWEVER...IN DISAGREEMENT ON
PLACEMENTS OF SFC FEATURES AND MOISTURE. RIGHT NOW ECMWF SHOWING A
CLIPPER TYPE SYSTEM GIVING LOW CHANCE FOR SNOW SUN INTO SUN
NIGHT...FOLLOWED BY ANOTHER SNOW POTENTIAL OVER EASTERN ZONES
TUESDAY. LOW CONFIDENCE AT THIS POINT FOR SNOW OCCURRING DURING ANY
SPECIFIC PERIOD. COLDEST NIGHT APPEARS TO BE SAT NIGHT AS RIDGE OF
HIGH PRESSURE MOVES OVER EARLY SUN MORNING...ALLOWING TEMPS TO DROP
TO AROUND OR JUST BELOW ZERO FOR MUCH OF THE AREA.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
RIDDLE/JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
236 PM CST MON JAN 23 2012
.SHORT TERM... /TONIGHT THROUGH THURSDAY/
THE FORECAST CHALLENGE FOR THE IMMEDIATE SHORT TERM WILL BE
TEMPERATURES AND SKY COVER...ESPECIALLY CHALLENGING OVER EASTERN
NORTH DAKOTA. THE CURRENT VISIBLE IMAGERY SHOWING THE DVL LAKE
BASIN IS CLEARING OUT AND WORKING ITS WAY DOWN THE SHEYENNE RIVER
BASIN. QUESTION IS HOW MUCH CONTRIBUTION HIGHER WINDS WILL MAKE
PRIOR TO SUNSET AS WINDS LIGHTEN UP. THE CURRENT NAM AND RUC H900
RH VALUES HAVE AN OKAY HANDLE ON THE CLEARING...BUT COULD BE
BETTER. THUS...QUESTION IS WHEN WILL THINGS CLEAR OUT AND HOW MUCH
TIME WILL TEMPS HAVE TO DIVE ESP IN AREAS OF FRESH SNOWFALL.
TONIGHT...CONTINUED TOWARD SLOWER CLEARING OF THE SKIES...WITH
MOST UNCERTAINTY OVER EASTERN ND WHERE SKIES ARE CURRENTLY CLEARING
OUT. SFC HIGH CURRENTLY OVER W CNTRL SD AND WILL DRIFT
EASTWARD...KEEPING ANY COMPLETE DECOUPLING AND THEREFORE COLDEST
TEMPERATURES IN SD. DO NOT EXPECT WINDS TO COMPLETELY DECOUPLE
OVER FGF CWA...WITH LIGHT NW WINDS BECOMING LIGHT AND SW OVER
NIGHT. SHOULD SKIES CLEAR OUT WHERE THE RIDGE AXIS/LIGHTEST WINDS
ARE...WILL NEED TO DROP TEMPS QUITE A BIT. BUT HAVE BUMPED UP
TEMPS QUITE A BIT ESP OVER NW AND W CNTRL MN...WHERE STRATUS IS
EXPECTED TO LINGER INTO TUE AM HOURS.
TUE AND TUE NIGHT...DRY UPPER WAVE WILL MOVE ACROSS CWA. TEMPS WILL BE
VERY DEPENDENT ON TONIGHTS LOWS AND STRATUS SITUATION TOMORROW
MORNING. CURRENTLY THINK FAR EASTERN ZONES WILL STILL BE OVC BUT
SCT OUT BY NOON...WITH REST OF CWA SEEING SOME DEG OF SOLAR. TEMPS
SHOULD RISE INTO 20S...WARMEST IN THE WEST.
WED AND WED NIGHT...LOW WILL MOVE ACROSS SOUTHERN CANADA...WITH
SFC BOUNDARY MOVING ACROSS NORTHERN TIES OF CONUS. LOOKS FOR
STRONGER SOUTHWESTERLY WINDS BECOMING WESTERLY WED NIGHT. THIS
WILL HELP BRING TEMPS UP INTO 30S...AND STRONG OVERNIGHT TEMPS
SHOULD KEEP WED NIGHT LOWS IN THE 20S. THERE IS A SLIGHT CHANCE
OVER SNOWFALL ACROSS NORTHERN ZONES WED AFTN INTO WED
NIGHT...HOWEVER WITH SFC LOW WELL NORTH OF CWA EXPECT ANY
ACCUMULATIONS TO BE MINIMAL. ALSO A CHANCE OF SOME LIQUID
PRECIP...BUT WITH LATEST THICKNESS VALUES HAVE CHANGED BACK TO ALL SNOW.
THU...WESTERLY WINDS THROUGHOUT DAY...WITH A CHANCE FOR SOME
LINGERING SNOW ACTIVITY IN FAR NORTHEAST AS LOW PRESSURE MOVES
INTO ONTARIO...AND OVER DVL REGION AS NEXT UPPER WAVE COMES
ACROSS. TEMPS SHOULD RISE INTO 30S GIVEN WARMER WED NIGHT LOWS.
.LONG TERM... /THU NIGHT THROUGH MONDAY/
MODELS CONTINUE TO BE IN FAIRLY DECENT AGREEMENT ON BRINGING WEAK
SHORTWAVES THROUGH THE NORTHWESTERLY FLOW...ALTHOUGH THERE ARE OF
COURSE MINOR DIFFERENCES IN TIMING. GIVEN THE UNCERTAINTY OF SUCH
MINOR SHORTWAVES AND WITH THE ENSEMBLE PRECIP PROBABILITIES
REMAINING FAIRLY LOW...WILL CONTINUE TO KEEP THE LOW POPS THAT
ALLBLEND GIVES US. AFTER SOME FAIRLY WARM TEMPERATURES AT THE
START OF THE PERIOD...THE DETERMINISTIC MODELS ARE IN GOOD
AGREEMENT ON BRINGING DOWN A DECENT COLD SURGE FOR THE WEEKEND AS
ONE OF THE SHORTWAVES HELPS TO AMPLIFY THE UPPER TROUGH TO OUR
EAST. TEMPS SHOULD RETURN CLOSER TO WHAT IS AVERAGE FOR THIS TIME
OF YEAR.
&&
.AVIATION...
SAT LOOP SHOWS THE CLEARING LINE AS MOVED EAST OF KDVL AND EXPECT
THAT IT WILL CONTINUE TO PUSH VERY SLOWLY EASTWARD OVERNIGHT. IFR
CEILINGS SHOULD GO UP TO MVFR BEFORE THE BACK EDGE OF THE CLOUDS
ARRIVE. THINK THAT KGFK AND KFAR SHOULD CLEAR OUT SOMETIME JUST
BEFORE 06Z WITH THE EASTERN TAF SITES NOT CLEARING OUT UNTIL THE
EARLY MORNING HOURS...IF THEY CLEAR OUT AT ALL. NORTHWEST WINDS
WILL DROP BELOW 12 KTS AND BECOME SOUTHERLY BY MORNING.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SPEICHER/JR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
635 PM EST TUE JAN 24 2012
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT OVER THE REGION TONIGHT. A DEVELOPING
AREA OF LOW PRESSURE OVER THE SOUTHERN PLAINS WILL LIFT NORTHEAST
WEDNESDAY INTO THURSDAY...BRINGING WIDESPREAD PRECIPITATION TO THE
OHIO VALLEY. A COLD FRONT WILL SWEEP THROUGH THE REGION THURSDAY
NIGHT AND THEN HIGH PRESSURE AND DRIER AIR WILL RETURN ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A STUBBORN AREA OF LOW STRATUS WILL LINGER OVER THE REGION FOR AT
LEAST THE NEXT FEW HOURS. LATEST RUC GUIDANCE INDICATES THAT THESE
CLOUDS SHOULD BEGIN TO GRADUALLY ERODE LATER THIS EVENING AS A 500
MB RIDGE CURRENTLY OVER THE MS VALLEY PUSHES A SHORTWAVE TROUGH
OVER EASTERN CANADA FURTHER DOWNSTREAM. MEANWHILE...SFC HIGH
PRESSURE AND DRIER LOW LEVEL AIR WILL BUILD INTO THE OHIO VALLEY
THIS EVENING...AND THE HIGH WILL REMAIN PARKED OVER THE REGION
OVERNIGHT.
SOME AREAS MAY EVEN BECOME MOSTLY CLEAR FOR A SHORT TIME TONIGHT
AND WINDS WILL BE LIGHT AS THE HIGH DRIFTS OVERHEAD. THUS...
EXPECTING DECENT RADIATIONAL COOLING OVERNIGHT AND STUCK CLOSE TO
MOS GUIDANCE FOR LOW TEMPS WITH READINGS IN THE LOWER 20S IN THE
NORTH AND IN THE UPPER 20S ACROSS THE FAR SOUTH.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
MID AND HIGH LEVEL CLOUDS WILL RAPIDLY ADVANCE INTO THE REGION
WEDNESDAY MORNING AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM OFF TO
THE SOUTHWEST. DESPITE A COOL START TO THE DAY AND SKIES BECOMING
MOSTLY CLOUDY BY AFTERNOON...TEMPERATURES SHOULD BE A BIT WARMER
THAN ON TUESDAY AS WEAK WARM AIR ADVECTION BEGINS. STUCK CLOSE TO
MOS GUIDANCE AGAIN FOR HIGHS WITH READINGS IN THE UPPER 30S NORTH
TO LOWER 40S SOUTH.
INTRODUCED SLIGHT CHANCE POPS IN THE FAR SOUTHWEST CWA BY 18Z
WEDNESDAY AS LATEST MODEL GUIDANCE CONTINUES TO PUSH PRECIP INTO
THE AREA WELL AHEAD OF THE ACTUAL LOW PRESSURE SYSTEM. HOWEVER...BEST
CHANCE FOR PRECIP WILL HOLD OFF UNTIL LATE WEDNESDAY INTO THURSDAY
AS ISENTROPIC LIFT STRENGTHENS AND A SLOW MOVING FRONT MOVES
ACROSS THE REGION. PRECIPITATION WILL SPREAD NORTHEAST ACROSS THE AREA
WEDNESDAY NIGHT INTO THURSDAY AS THE LOW APPROACHES...AND THE
LATEST ECMWF...NAM AND GFS ARE IN AGREEMENT WITH THE LOW TRACKING
NORTHEAST ACROSS SOUTHERN OH INTO WESTERN PA BY THURSDAY NIGHT.
HIGHEST QPF IS PLACED ACROSS SOUTHERN HALF OF CWA WITH THE LATEST
NAM/GFS BOTH SUGGESTING AROUND AN INCH. AREAS ALONG AND SOUTH OF
THE OHIO RIVER WILL LIKELY SEE LOCALLY HIGHER AMOUNTS UP TO AROUND
1.25 INCHES. THERE STILL REMAINS SOME UNCERTAINTY WITH REGARD TO
PRECIPITATION AMOUNTS...BUT WITH THE GROUND STILL VERY MOIST FROM
RECENT RAINFALL...MINOR FLOODING OF SOME AREA CREEKS AND STREAMS
WOULD BE POSSIBLE NEAR THE AXIS OF HEAVIEST RAINFALL.
TEMPERATURE PROFILES INDICATE THAT PRECIPITATION WILL FALL AS RAIN
IN THE SOUTH...BUT AREAS NORTH OF I-70 COULD SEE A BIT OF LIGHT
SNOW MIX IN WITH THE RAIN WEDNESDAY NIGHT. FORECAST SOUNDINGS SHOW
A NEARLY ISOTHERMAL LOW LEVEL TEMPERATURE PROFILE HOVERING RIGHT
AROUND FREEZING IN THE FAR NORTH WEDNESDAY NIGHT...SO A VERY BRIEF
PERIOD OF LIGHT FREEZING RAIN CANNOT BE RULED OUT ENTIRELY AT
THIS POINT FOR SOME AREAS IN THE FAR NORTH. DID NOT INCLUDE
MENTION IN THE FORECAST AT THIS POINT DUE TO LINGERING UNCERTAINTY.
AS TEMPERATURES DROP BELOW FREEZING BEHIND A COLD FRONT THURSDAY
NIGHT...ANY LINGERING RAIN WILL LIKELY MIX WITH AND CHANGE OVER TO
SOME LIGHT SNOW.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
PRECIPITATION WILL COME TO AN END EARLY FRIDAY WITH THE LOW MOVING
RAPIDLY EASTWARD AWAY FROM OUR AREA. A WEAK RIDGE WILL BUILD IN
PLACE BRIEFLY ON FRIDAY THROUGH FRIDAY NIGHT. AFTER THAT...A DEEP
UPPER LOW WILL SPIN SOUTHEASTWARD OVER ONTARIO. THIS WILL HELP
USHER IS AN ARCTIC AIRMASS OVER OUR REGION. MODELS ARE IN GOOD
AGREEMENT ON THIS SCENARIO...WHILE KEEPING THE LOW NEARLY STATIONARY
OVER SOUTHERN CANADA THROUGH THE WEEKEND. THIS WILL RESULT IN A
BREEZY AND COLD WEEKEND FOR OUR FORECAST AREA...WITH BELOW NORMAL
TEMPERATURES. WEAK SHORTWAVES WILL PIVOT AROUND THE LOW...WHICH
COULD PRODUCE INTERMITTENT LIGHT SNOW SHOWERS ACROSS THE NORTHERN
HALF OF THE FORECAST AREA SATURDAY AFTERNOON THROUGH SUNDAY.
THE LOW OVER SOUTHERN CANADA IS EXPECTED TO SHIFT EASTWARD BY
MONDAY. RIDGING WILL THEN BUILD IN ITS PLACE...WITH A WARMING TREND
AND FAIR WEATHER MONDAY INTO MONDAY NIGHT. A STORM SYSTEM
APPROACHING FROM THE PLAINS MAY BRING CHANCES FOR PRECIPITATION ON
TUESDAY.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
MVFR STRATUS DECK IS STILL HANGING IN ACROSS THE AREA THIS
EVENING AND HAS NOT SHOWN MUCH IN THE WAY OF MOVEMENT OVER THE
LAST SEVERAL HOURS AS CLEARING LINE HAS REMAINED JUST SOUTHEAST OF
KCVG/KLUK. WE ARE SEEING SOME EROSION ON THE WESTERN EDGE BACK
ACROSS CENTRAL INDIANA AND SOME 925 MB DRYING IS FORECAST TO
PUSH IN FROM THE NORTHWEST THROUGH THIS EVENING. THIS SHOULD ALSO
BE AIDED BY A TRANSITION TO SOME LOW LEVEL WAA OVERNIGHT AS
SURFACE HIGH PRESSURE AXIS BEGINS TO PUSH EAST. DESPITE THIS...AM
HESITANT TO CLEAR THINGS OUT TOO QUICKLY GIVEN HOW PERSISTENT THIS
STRATUS DECK HAS BEEN. WILL THEREFORE LINGER IT A BIT LONGER THAN
SUGGESTED BY MODELS AND SEE HOW THINGS PLAY OUT. IF WE DO CLEAR
OUT EARLY ENOUGH...WE COULD SEE SOME FOG DEVELOP GIVEN LIGHT WINDS AND
RELATIVELY MOIST GROUND. HAVE HEDGED NOW WITH JUST SOME MVFR
BR LATER TONIGHT...BUT DEPENDING ON TIMING OF ANY CLEARING...WE COULD
SEE SOME LOWER VSBYS DUE TO FOG. ANY REMAINING LOW CLOUDS SHOULD
EVENTUALLY CLEAR OUT THROUGH WEDNESDAY MORNING AS WE TRANSITION
INTO A BETTER WAA PATTERN. HIGH AND MID LEVEL CLOUDS WILL BE ON
THE INCREASE THROUGH THE DAY AHEAD OF THE NEXT SYSTEM APPROACHING
FROM THE SOUTHWEST...WITH LOWER CIGS AND PCPN SPREADING INTO THE
AREA TOWARD THE END OF THE TAF PERIOD.
OUTLOOK...MVFR CIGS/VSBYS POSSIBLE WEDNESDAY NIGHT...WITH
CONDITIONS AS LOW AS IFR POSSIBLE THURSDAY AND THURSDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...KURZ
NEAR TERM...KURZ
SHORT TERM...KURZ
LONG TERM...LATTO
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1233 PM EST MON JAN 23 2012
.SYNOPSIS...
STRONG COLD FRONT WHIPS THROUGH THIS AFTERNOON AND EARLY EVENING.
HIGH PRESSURE IN CONTROL TUESDAY AFTERNOON INTO WEDNESDAY. ANOTHER
SYSTEM PROVIDES RAIN WEDNESDAY NIGHT INTO THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
MUCH OF THE SHOWER ACTIVITY HAS DECREASED FROM WEST TO EAST.
COLD FRONT STILL REMAINS WELL TO THE WEST ACROSS INDIANA. BOTH
RADAR AND HRRR MODEL SEEM TO BE INDICATING ANOTHER LINE OF
CONVECTION DEVELOPING OUT AHEAD OF THIS FRONT AS IT PUSHES EAST
INTO THE AREA. SPC HAS SOUTHEAST OHIO IN A SEE TEXT. STILL SOME
UNCERTAINTY AS TO WHETHER THUNDERSTORMS WILL BE ABLE TO
DEVELOP...OR JUST CONVECTIVE SHOWERS...DUE TO WARM AIR ALOFT. FOR
NOW...ADDED ISOLD THUNDER...MAINLY TO SOUTHEAST OHIO ZONES FOR
THIS AFTERNOON AS THE FRONT PUSHES TOWARDS THE REGION. IF ANY
DEEPER CONVECTION IS ABLE TO FORM...STRONGER WINDS ALOFT MAY BE
ABLE TO MIX DOWN TOWARDS THE SURFACE. WILL LET THE WIND ADVISORY
RIDE FOR NOW...AND WILL PROBABLY JUST LET EVENING SHIFT DECIDE
WHETHER TO CANCEL IT EARLY. OTHERWISE...MADE NO MAJOR CHANGES TO
THE FORECAST.
PREVIOUS DISCUSSION...
ALL EYES ARE ON THE LONG LINE OF CONVECTION NOW MOVING ACROSS THE
TENNESSEE AND LOWER OHIO VALLEYS. THIS LINE IS IN ADVANCE OF A COLD
FRONT...WHICH WILL CROSS A BIT LATER THAN THOUGHT PREVIOUSLY...
SOMETHING LIKE THE 20Z TO 03Z RANGE. BEFORE THEN...HAVE SOLID 100
POPS WITH THE MAIN PRECIP LINE...WHICH MOVES THROUGH BETWEEN 10Z AND
15Z. NUMBER OF LIGHTNING STRIKES IS INCHING DOWNWARD...STILL PLENTY
ENOUGH FOR MAINTAINING THUNDER MENTION.
MAIN CONCERN TODAY WILL BE WIND GUSTS. H850 JET OF 60-70
KNOTS WILL REACH THE TRI-STATE AREA BY 12Z...BEFORE WEAKENING AS THE
SURFACE/UPPER LOWS ROTATE NORTH INTO THE GREAT LAKES. STILL SEEING
A FAIRLY STOUT LOW LEVEL INVERSION WHICH WILL KEEP THE STRONGEST OF
THE WINDS ALOFT...KEEPING THE RISK OF SEVERE CONVECTIVE GUSTS IN
CHECK. HOWEVER...LINE OF SHRA/TSRA MAY BE ENOUGH TO DRAG DOWN 30-40
KNOT GUSTS ALONG AND IMMEDIATELY BEHIND THE LINE...AND PLAYED IT
THIS WAY IN THE GRIDS. ONCE INVERSION MIXES OUT LATER
TODAY...SHOULD CONTINUE TO SEE 20-30 KNOT GUSTS. GOING TO CONTINUE
WITH WIND ADVISORY...ALTHOUGH COULD SEE IT BEING CANCELLED BEFORE
EXPIRATION AT 02Z.
DID GO AHEAD AND CANCEL THE FREEZING RAIN ADVISORY FOR THE EASTERN
SLOPES EARLY. WITH TEMPERATURES STRUGGLING TO STAY BELOW FREEZING
AND LACK OF PRECIPITATION...ICE ACCRETION THREAT IS LOOKING MINOR.
STILL COULD SEE A FEW POCKETS AROUND SUNRISE THOUGH.
BEHIND THE MAIN CONVECTIVE LINE...SCATTERED SHOWERS MAY
LINGER...ESPECIALLY ACROSS THE NORTH...AS MAIN H500 TROUGH AXIS/VORT
MAX SKIRTS THE AREA. LINGERING MOISTURE PLUS PEDESTRIAN COLD
ADVECTION MAY BE ENOUGH TO CONTINUE SHRA INTO THE EVENING BEFORE
FROPA. LIMITED POPS TO CHANCE WITH THIS ACTIVITY.
HIGH PRESSURE MOVES FROM THE ARKLATEX INTO THE TENNESSEE VALLEY
TONIGHT...WITH SOUTHWEST FLOW PUSHING DRIER AIR INTO THE REGION.
CLOUDS WILL LINGER ACROSS THE NORTH WHILE SKIES CLEAR ELSEWHERE
ESPECIALLY SOUTH/WEST OF I-64. PRECIPITATION MAY END AS SNOWFLAKES
ON THE HIGHEST RIDGES OVERNIGHT...CANNOT RULE OUT FLURRIES THROUGH 12Z.
DID NOT CHANGE TEMPERATURES TOO MUCH FROM PREVIOUS FORECAST. DID
GENERALLY NUDGE TOWARD LOWER MOS NUMBERS TODAY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
WAS A BIT COOLER ON MAXIMUM TEMPERATURES ON TUESDAY...EVEN THOUGH
SOUTHERN AND WESTERN COUNTIES SHOULD SEE PLENTY OF AFTERNOON
SUNSHINE...THE 850 MB THERMAL TROF HANGS OVER US THROUGH 18Z. DID
INCREASE THE STRATOCUMULUS CLOUDS ON TUESDAY...ESPECIALLY NE OF
CRW. INCLUDED SOME SPRINKLES OR FLURRIES IN THE CKB TO EKN AND
CNTRL WV MOUNTAIN CORRIDOR INTO TUESDAY AFTERNOON. WINDS SHOULD
STILL BE QUITE NOTICEABLE DURING THE DAY.
PEACEFUL TUESDAY NIGHT STILL EXPECTED.
HIGH CLOUDS INCREASE WEDNESDAY...AND WITH LIGHT WINDS...HELD DOWN
TEMPERATURES A FEW DEGREES.
TIMING THE INITIAL PCPN STILL UNCERTAIN...SO NO REASON TO ADJUST
MUCH WITH WEDNESDAY NIGHT.
THE 00Z ECWMF HAS COME MORE IN LINE WITH THE GFS ON SPEED OF
SOUTHERN 500 MB TROF MOVING EAST. CANADIAN STILL A BIT SLOWER.
A GOOD SSW 850 MB FEED OF DEW POINTS AROUND 8C INTO AN EAST TO WEST
BAROCLINIC ZONE OVER US. SO A BIT CONCERNED AT THIS DISTANCE IN
TIME...ON SOME HEAVIER RAIN AND MAYBE WATER ISSUES. WILL INCREASE
POPS THURSDAY INTO THURSDAY EVENING TO LIKELY ESPECIALLY FOR MUCH OF
THE CWA.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
LOTS OF VARIABILITY BETWEEN MODELS IN THIS PERIOD...LEADING TO A
LOW CONFIDENCE FORECAST. USED A BLEND OF THE GFS AND UKMET FOR
THURSDAY AND FRIDAY...THEN WENT MORE TOWARD THE GFS FOR SATURDAY AND
SUNDAY. THIS WOULD PROVIDE A SOUTHERN STREAM SYSTEM FOR WEDNESDAY
NIGHT AND THURSDAY...FOLLOWED BY ANOTHER FRIDAY NIGHT AND SATURDAY.
BEHIND THE SATURDAY SYSTEM...COLDER AIR MAY MOVE INTO THE REGION.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
18Z MONDAY THROUGH 18Z TUESDAY...
ANOTHER ROUND OF CONVECTION IS APPROACHING THE AREA FROM THE WEST.
THIS WILL PRIMARILY AFFECT SOUTHEAST OHIO...EASTERN KENTUCKY...AND
NORTHERN WEST VIRGINIA. THERE IS THE POSSIBILITY OF STRONG WIND
GUSTS OF UP TO 50 KTS WITH ANY CONVECTION. BRIEF MVFR CAN ALSO BE
EXPECTED IN CONVECTION. ANY SHOWER/STORM ACTIVITY SHOULD START TO
DIE DOWN AFTER 00-03Z AS THE COLD FRONTAL BOUNDARY PUSHES THROUGH
THE AREA.
IN ADDITION TO ANY SHOWER/STORM ACTIVITY...STRONG WINDS ALOFT MAY MIX
DOWN THIS AFTERNOON...WITH GUSTS OF UP TO 40 KTS POSSIBLE.
OCCASIONAL GUSTS OF OVER 40 KTS MAY BE POSSIBLE OVER THE HIGHER
TERRAIN.
HIGH PRESSURE WILL BUILD IN FROM THE WEST LATE TONIGHT...FOR A
GRADUAL CLEARING TREND FROM SOUTHWEST TO NORTHEAST...AND FOR A
GRADUAL DECREASE IN WINDS OVERNIGHT. WINDS WILL BE GUSTY AGAIN
TOMORROW...MAINLY AFTER 15Z...WITH THE ONSET OF DAYTIME HEATING.
HOWEVER...WINDS ARE NOT EXPECTED TO BE AS GUSTY...WITH GUSTS IN
THE TEEN TO 20 KT RANGE EXPECTED.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: THERE MAY BE MORE WIDESPREAD CONVECTION THAN
CURRENTLY FORECAST. WINDS MAY NOT BE AS STRONG AS CURRENTLY
FORECAST.
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 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY M M M M M M L H H H H H
HTS CONSISTENCY M M M M M H H H H H H H
BKW CONSISTENCY L L M M L L L H H H H H
EKN CONSISTENCY M M M L L L L M M H H H
PKB CONSISTENCY M M M M M M M H H H H H
CKB CONSISTENCY H H H H M M M H H H H H
AFTER 18Z TUESDAY...
IFR POSSIBLE WEDNESDAY NIGHT INTO THURSDAY NIGHT IN LOW
CLOUDS...RAIN...AND FOG.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR WVZ005>011-
013>020-024>040-046-047.
OH...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR OHZ066-067-075-
076-083>087.
KY...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR KYZ101>103-105.
VA...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR VAZ003-004.
&&
$$
SYNOPSIS...KTB/CL
NEAR TERM...CL/SL
SHORT TERM...KTB
LONG TERM...RPY
AVIATION...SL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1029 AM EST MON JAN 23 2012
.SYNOPSIS...
STRONG COLD FRONT WHIPS THROUGH THIS AFTERNOON AND EARLY EVENING.
HIGH PRESSURE IN CONTROL TUESDAY AFTERNOON INTO WEDNESDAY. ANOTHER
SYSTEM PROVIDES RAIN WEDNESDAY NIGHT INTO THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
MUCH OF THE SHOWER ACTIVITY HAS DECREASED FROM WEST TO EAST.
COLD FRONT STILL REMAINS WELL TO THE WEST ACROSS INDIANA. BOTH
RADAR AND HRRR MODEL SEEM TO BE INDICATING ANOTHER LINE OF
CONVECTION DEVELOPING OUT AHEAD OF THIS FRONT AS IT PUSHES EAST
INTO THE AREA. SPC HAS SOUTHEAST OHIO IN A SEE TEXT. STILL SOME
UNCERTAINTY AS TO WHETHER THUNDERSTORMS WILL BE ABLE TO
DEVELOP...OR JUST CONVECTIVE SHOWERS...DUE TO WARM AIR ALOFT. FOR
NOW...ADDED ISOLD THUNDER...MAINLY TO SOUTHEAST OHIO ZONES FOR
THIS AFTERNOON AS THE FRONT PUSHES TOWARDS THE REGION. IF ANY
DEEPER CONVECTION IS ABLE TO FORM...STRONGER WINDS ALOFT MAY BE
ABLE TO MIX DOWN TOWARDS THE SURFACE. WILL LET THE WIND ADVISORY
RIDE FOR NOW...AND WILL PROBABLY JUST LET EVENING SHIFT DECIDE
WHETHER TO CANCEL IT EARLY. OTHERWISE...MADE NO MAJOR CHANGES TO
THE FORECAST.
PREVIOUS DISCUSSION...
ALL EYES ARE ON THE LONG LINE OF CONVECTION NOW MOVING ACROSS THE
TENNESSEE AND LOWER OHIO VALLEYS. THIS LINE IS IN ADVANCE OF A COLD
FRONT...WHICH WILL CROSS A BIT LATER THAN THOUGHT PREVIOUSLY...
SOMETHING LIKE THE 20Z TO 03Z RANGE. BEFORE THEN...HAVE SOLID 100
POPS WITH THE MAIN PRECIP LINE...WHICH MOVES THROUGH BETWEEN 10Z AND
15Z. NUMBER OF LIGHTNING STRIKES IS INCHING DOWNWARD...STILL PLENTY
ENOUGH FOR MAINTAINING THUNDER MENTION.
MAIN CONCERN TODAY WILL BE WIND GUSTS. H850 JET OF 60-70
KNOTS WILL REACH THE TRI-STATE AREA BY 12Z...BEFORE WEAKENING AS THE
SURFACE/UPPER LOWS ROTATE NORTH INTO THE GREAT LAKES. STILL SEEING
A FAIRLY STOUT LOW LEVEL INVERSION WHICH WILL KEEP THE STRONGEST OF
THE WINDS ALOFT...KEEPING THE RISK OF SEVERE CONVECTIVE GUSTS IN
CHECK. HOWEVER...LINE OF SHRA/TSRA MAY BE ENOUGH TO DRAG DOWN 30-40
KNOT GUSTS ALONG AND IMMEDIATELY BEHIND THE LINE...AND PLAYED IT
THIS WAY IN THE GRIDS. ONCE INVERSION MIXES OUT LATER
TODAY...SHOULD CONTINUE TO SEE 20-30 KNOT GUSTS. GOING TO CONTINUE
WITH WIND ADVISORY...ALTHOUGH COULD SEE IT BEING CANCELLED BEFORE
EXPIRATION AT 02Z.
DID GO AHEAD AND CANCEL THE FREEZING RAIN ADVISORY FOR THE EASTERN
SLOPES EARLY. WITH TEMPERATURES STRUGGLING TO STAY BELOW FREEZING
AND LACK OF PRECIPITATION...ICE ACCRETION THREAT IS LOOKING MINOR.
STILL COULD SEE A FEW POCKETS AROUND SUNRISE THOUGH.
BEHIND THE MAIN CONVECTIVE LINE...SCATTERED SHOWERS MAY
LINGER...ESPECIALLY ACROSS THE NORTH...AS MAIN H500 TROUGH AXIS/VORT
MAX SKIRTS THE AREA. LINGERING MOISTURE PLUS PEDESTRIAN COLD
ADVECTION MAY BE ENOUGH TO CONTINUE SHRA INTO THE EVENING BEFORE
FROPA. LIMITED POPS TO CHANCE WITH THIS ACTIVITY.
HIGH PRESSURE MOVES FROM THE ARKLATEX INTO THE TENNESSEE VALLEY
TONIGHT...WITH SOUTHWEST FLOW PUSHING DRIER AIR INTO THE REGION.
CLOUDS WILL LINGER ACROSS THE NORTH WHILE SKIES CLEAR ELSEWHERE
ESPECIALLY SOUTH/WEST OF I-64. PRECIPITATION MAY END AS SNOWFLAKES
ON THE HIGHEST RIDGES OVERNIGHT...CANNOT RULE OUT FLURRIES THROUGH 12Z.
DID NOT CHANGE TEMPERATURES TOO MUCH FROM PREVIOUS FORECAST. DID
GENERALLY NUDGE TOWARD LOWER MOS NUMBERS TODAY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
WAS A BIT COOLER ON MAXIMUM TEMPERATURES ON TUESDAY...EVEN THOUGH
SOUTHERN AND WESTERN COUNTIES SHOULD SEE PLENTY OF AFTERNOON
SUNSHINE...THE 850 MB THERMAL TROF HANGS OVER US THROUGH 18Z. DID
INCREASE THE STRATOCUMULUS CLOUDS ON TUESDAY...ESPECIALLY NE OF
CRW. INCLUDED SOME SPRINKLES OR FLURRIES IN THE CKB TO EKN AND
CNTRL WV MOUNTAIN CORRIDOR INTO TUESDAY AFTERNOON. WINDS SHOULD
STILL BE QUITE NOTICEABLE DURING THE DAY.
PEACEFUL TUESDAY NIGHT STILL EXPECTED.
HIGH CLOUDS INCREASE WEDNESDAY...AND WITH LIGHT WINDS...HELD DOWN
TEMPERATURES A FEW DEGREES.
TIMING THE INITIAL PCPN STILL UNCERTAIN...SO NO REASON TO ADJUST
MUCH WITH WEDNESDAY NIGHT.
THE 00Z ECWMF HAS COME MORE IN LINE WITH THE GFS ON SPEED OF
SOUTHERN 500 MB TROF MOVING EAST. CANADIAN STILL A BIT SLOWER.
A GOOD SSW 850 MB FEED OF DEW POINTS AROUND 8C INTO AN EAST TO WEST
BAROCLINIC ZONE OVER US. SO A BIT CONCERNED AT THIS DISTANCE IN
TIME...ON SOME HEAVIER RAIN AND MAYBE WATER ISSUES. WILL INCREASE
POPS THURSDAY INTO THURSDAY EVENING TO LIKELY ESPECIALLY FOR MUCH OF
THE CWA.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
LOTS OF VARIABILITY BETWEEN MODELS IN THIS PERIOD...LEADING TO A
LOW CONFIDENCE FORECAST. USED A BLEND OF THE GFS AND UKMET FOR
THURSDAY AND FRIDAY...THEN WENT MORE TOWARD THE GFS FOR SATURDAY AND
SUNDAY. THIS WOULD PROVIDE A SOUTHERN STREAM SYSTEM FOR WEDNESDAY
NIGHT AND THURSDAY...FOLLOWED BY ANOTHER FRIDAY NIGHT AND SATURDAY.
BEHIND THE SATURDAY SYSTEM...COLDER AIR MAY MOVE INTO THE REGION.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
WEAKENED CONVECTIVE LINE NOW APPROACHING THE TRI-STATE AREA.
LIGHTNING STRIKES HAVE DIMINISHED GREATLY...BUT THERE IS STILL
POTENTIAL FOR 30-40 KNOT GUSTS AS THE LINE PASSES. HAVE A 2 HOUR
WINDOW OF STRONG WIND GUSTS/TEMPO IFR CONDITIONS AT HTS/CRW/PKB/CKB
FOR THE CONVECTIVE LINE. THINK WINDS MIGHT WEAKEN A BIT AND DID NOT
PUT THE STRONG GUSTS IN EKN/BKW AT THIS TIME.
BEHIND THIS LINE...WINDS WILL CONTINUE TO GUST BETWEEN 20 AND 30
KNOTS IN ADVANCE OF ACTUAL COLD FRONT WHICH CROSSES DURING THE LATE
AFTERNOON AND EARLY EVENING HOURS. A FEW SCATTERED SHOWERS WILL
LINGER UNTIL FROPA. CIGS SHOULD IMPROVE TO LOW END VFR BY AFTERNOON
BEHIND THE INITIAL CONVECTION...AND IMPROVE FURTHER THIS EVENING AS
HIGH PRESSURE AND DRIER AIR WORK IN FROM THE SOUTHWEST.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: MVFR CIGS COULD LINGER A BIT LONGER THAN
CURRENTLY FORECAST. STRONG WIND GUSTS MAY NOT YET MATERIALIZE.
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 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY L M M H M M M M H H H H
HTS CONSISTENCY L L L L L L M M H H H H
BKW CONSISTENCY L M L L M H H H M H M H
EKN CONSISTENCY L M L M H H M M M H M M
PKB CONSISTENCY L L M L L L L L H H H H
CKB CONSISTENCY L M M M H H M M H H M M
AFTER 18Z TUESDAY...
IFR POSSIBLE WEDNESDAY NIGHT AND THURSDAY IN LOW CLOUDS...RAIN...AND
FOG.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR WVZ005>011-
013>020-024>040-046-047.
OH...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR OHZ066-067-075-
076-083>087.
KY...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR KYZ101>103-105.
VA...WIND ADVISORY UNTIL 9 PM EST THIS EVENING FOR VAZ003-004.
&&
$$
SYNOPSIS...KTB/CL
NEAR TERM...CL/SL
SHORT TERM...KTB
LONG TERM...RPY
AVIATION...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
728 PM EST TUE JAN 24 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE MIDWESTERN STATES WILL BUILD EAST ACROSS
PENNSYLVANIA ON WEDNESDAY...ACCOMPANIED BY DRY CONDITIONS AND
ABOVE NORMAL TEMPERATURES.
AN APPROACHING FRONTAL SYSTEM WILL BRING A RETURN OF UNSETTLED
WEATHER WEDNESDAY NIGHT AND THURSDAY BEFORE COLDER WEATHER RETURNS
FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AN EXTENSIVE SHIELD OF STRATO-CU CONTINUES TO BLANKET ALL OF
PENN...EXCEPT FOR ABOUT THE SOUTHERN 1/4 OF THE STATE.
THIS CLOUD DECK WILL BE SLOW TO ERODE ACROSS CENTRAL AND NRN PENN
OVER THE NEXT 6-8 HOURS...AS THE 850 MB FLOW REMAINS WEAKLY
CYCLONIC AND SLIGHT COOLING OF THE MEAN 850-700MB LAYER DRIFTS SE
ACROSS THE REGION. 23Z RUC MODEL INDICATES THAT THIS WEAK MID
LEVEL THERMAL TROUGH WILL SLIDE EAST OF PENNSYLVANIA BY 06Z.
SINCE THE 850 MB RIDGE AXIS WILL STILL BE OFF TO THE WEST OF PENN
BY DAYBREAK...BKN-OVC STRATO CU COULD BE QUITE STUBBORN TO LEAVE
THE REGION NEAR AND TO THE NORTH OF INTERSTATE 80.
WILL KEEP A CLOSE EYE ON THE CLOUD TRENDS OVER THE NEXT FEW HOURS
SINCE IT WILL BE A KEY FACTOR IN THE OVERNIGHT LOWS.
A FEW FLURRIES COULD OCCUR ACROSS THE FAR NW ZONES...BUT THAT/S
ABOUT IT IN THE PRECIP DEPT.
THE CLOUDS WILL HELP KEEP OVERNIGHT LOWS WARMER THAN NORMAL BY
SOME 5-10 DEG.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
LOOKS LIKE A FAIR AMOUNT OF LOW CLOUDS WILL HANG TOUGH OVER
WESTERN AREAS DURING THE DAY WEDNESDAY...EVEN AS SFC HIGH PRESSURE
BUILDS IN. EXPECT THE MOST CLOUDS NORTH AND WEST...AND GREATEST
AMOUNT OF SUN ACROSS THE SOUTH AND EAST...WITH HIGHS A COUPLE TO
SEVERAL DEG ABOVE NORMAL.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
FLAT NORTHERN STREAM WAVE CROSSES THE REGION WEDNESDAY NIGHT INTO
THURSDAY BEFORE A STRONGER SOUTHERN STREAM TROF LIFTS INTO THE EAST
U.S. LATE IN THE WEEK. NORTHERN STREAM ENERGY ON THE HEELS OF THE
SRN TROF LOOKS TO FORM A LARGE BUT PROGRESSIVE UPPER TROF OVER THE
NERN NOAM BY THE END OF THE PERIOD.
RIDGING WILL SUPPORT DRY CONDS WED INTO EARLY THURS BEFORE THE
APPROACHING SRN STREAM TROF LIFTS TOWARD THE REGION...WITH A SFC
LOW EXPECTED NEAR DC BY FRIDAY MORNING. GIVEN CLIMATOLOGICALLY
COLD AIR IN PLACE A SNOWSTORM WOULD BE PRETTY LIKELY...BUT AGAIN
THIS TIME AROUND AT LEAST SOME OF THE AREA WILL BE ALL RAIN WITH A
MIX OVER MOST OF CENTRAL PA. THE NORTHERN STREAM WAVE WILL PULL A
COLD FRONT ACROSS THE STATE ON SATURDAY. THE RESULTING UPPER LOW
OVER NERN NOAM WILL KEEP A COLD WESTERLY TO NWRLY FLOW OVER PA
FROM SUNDAY INTO MONDAY WITH SCTD SNOW SHOWERS MAINLY IN THE MTNS.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
WESTERLY FLOW CONTINUES POST COLD FRONT...KEEPING EXTENSIVE
SHIELD OF LOW CLOUDS ALL THE WAY BACK TO THE GREAT LAKES...
EXTENDING INTO HIGHER TERRAIN IN MY WESTERN AND NORTHERN CWA.
EXPECT CEILINGS TO REMAIN IN THE 1000-2000FT RANGE WITH PERHAPS A
FEW FLURRIES FROM JST NORTH THRU BFD...WHILE CENTRAL MTNS
EXPERIENCE CIGS IN THE 2500-3500FT RANGE OVERNIGHT. VFR CIGS IN
THE EAST FROM KIPT TO KLNS...THOUGH JUST A SMALL CHANCE OF VISBY
BEING REDUCED FOR A TIME LATER TONIGHT WITH A BIT OF FOG.
IMPROVING CONDITIONS ON WED AS SFC HIGH PRESSURE BUILDS
IN...BREAKING INVERSION AND IMPROVING CIGS BY LATE MORNING. SO
EVENTUALLY A VFR DAY FOR MOST...WITH MVFR HANGING IN THE LONGEST
IN THE NW MTNS /KBFD/.
OUTLOOK...
WED...MVFR/SNOW SHOWERS NW POSSIBLE. NO SIG WX ELSEWHERE.
THU...MVFR/IFR DEVELOPING WITH RAIN OR POSSIBLE WINTRY MIX OF
PRECIP.
FRI...VFR MOST OF THE AREA...BUT MVFR AND IFR ACROSS THE WESTERN
MOUNTAINS WITH SNOW SHOWERS...ESPECIALLY EARLY.
SAT/SUN...MAINLY VFR...BUT MVFR POSSIBLE AT JST AND BFD WITH
LOWER CLDS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT/LA CORTE
LONG TERM...DEVOIR/GARTNER
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
602 PM EST MON JAN 23 2012
.SYNOPSIS...
AN OCCLUDED FRONT WILL PUSH ACROSS CENTRAL PA TONIGHT. HIGH
PRESSURE WILL BRING DRIER CONDITIONS AND ABOVE NORMAL TEMPERATURES
FOR THE MID WEEK PERIOD.
THE NEXT SYSTEM SLATED TO BRING UNSETTLED WEATHER SHOULD ARRIVE
LATER THURSDAY OR FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
COLD FRONT MOVING INTO WESTERN PA THIS EVENING...ACCOMPANIED BY A
BROKEN LINE OF SHRA AND EVEN A FEW LIGHTNING STRIKES ACROSS THE NW
MTNS. RUC STABILITY INDICES SUGGEST THE NW MTNS ARE THE ONLY AREA
SUSCEPTIBLE TO LIGHTNING BTWN 23Z-01Z. ELSEWHERE...EXPECT SHOWERS TO
DWINDLE AS THEY MOVE INTO THE STABLE AIR MASS ENTRENCHED EAST OF
THE ALLEGHENIES. EVENING POPS RANGE FROM NR 100 PCT ACROSS THE NW
MTNS...TO ARND 10 PCT LOWER SUSQ VALLEY.
FRONT WILL COME THRU THE CENTRAL COUNTIES LATER THIS
EVENING...ACCOMPANIED BY THE CHC OF A -SHRA AND BRIEFLY RISING
TEMPS AS LOW LVL INVERSION BREAKS. FURTHER EAST...AREAS OF FOG
WILL BE THE BIGGEST CONCERN THIS EVENING OVR THE SUSQ VALLEY /HARRISBURG
DOWN TO 1/2SM AT 22Z/. HOWEVER...ARRIVAL OF OCCLUDED FRONT WILL
BRING DRIER WESTERLY FLOW AND LIKELY DISPERSE THE FOG LATE
TONIGHT.
BEHIND THE FRONT WE WILL TRANSITION TO A MORE TYPICAL COOL AIR
ADVECTION REGIME. RESIDUAL LOW LVL MOISTURE ASCENDING THE
ALLEGHENIES ON WSW FLOW WILL LIKELY PRODUCE SCT -SHSN LATER
TONIGHT. MDL QPF SUGGESTS A LIGHT DUSTING IS POSSIBLE OVR THE NW
MTNS BY DAWN.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
WEST TO WEST-SOUTHWEST SFC WINDS WILL GUST IN THE 20 TO 25 MPH
RANGE TUESDAY BEFORE DIMINISHING AS THE DAY WEARS ON. SOME SNOW
SHOWER ACTIVITY CAN BE EXPECTED OVER WESTERN HIGH TERRAIN BUT THE
POST FRONTAL AIR ISN`T TERRIBLY COLD SO WE ARE NOT EXPECTING MORE
THAN NUISANCE ACCUMS OF SNOW OVER THE LAURELS AND NW MOUNTAINS.
MAX TEMPS IN THE WAKE OF THE COLD/OCCLUDED FRONT WILL NOT BE ALL
THAT COLD. IN FACT...AFTERNOON HIGHS TUESDAY WILL BE SOME 5-8F
ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
WEAK NORTHERN-SOUTHERN STREAM COUPLED RIDGING OVER THE MID ATLC AT
THE START OF THE PERIOD WILL GIVE WAY TO FLAT NORTHERN STREAM
FLOW FOR A DAY OR TWO BEFORE A STRONGER SOUTHERN STREAM TROF
LIFTS INTO THE EAST U.S. LATE IN THE WEEK. NORTHERN STREAM ENERGY
ON THE HEELS OF THE SRN TROF LOOKS TO FORM A LARGE BUT PROGRESSIVE
UPPER TROF OVER THE NERN NOAM BY THE END OF THE PERIOD.
RIDGING WILL SUPPORT DRY CONDS WED INTO EARLY THURS BEFORE THE
APPROACHING SRN STREAM TROF LIFTS TOWARD THE REGION...WITH A SFC
LOW EXPECTED NEAR DC BY FRIDAY MORNING. GIVEN CLIMATOLOGICALLY
COLD AIR IN PLACE A SNOWSTORM WOULD BE PRETTY LIKELY...BUT AGAIN
THIS TIME AROUND AT LEAST SOME OF THE AREA WILL BE ALL RAIN WITH A
MIX OVER MOST OF CENTRAL PA. THE NORTHERN STREAM WAVE WILL PULL A
COLD FRONT ACROSS THE STATE ON SATURDAY. THE RESULTING UPPER LOW
OVER NERN NOAM WILL KEEP A COLD WESTERLY TO NWRLY FLOW OVER PA
FROM SUNDAY INTO MONDAY WITH SCTD SNOW SHOWERS MAINLY IN THE MTNS.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS EXPECTED...FAR WESTERN AREAS CLEAR NOW...STILL SLOW TO MOVE
LOW CLDS OUT AT AOO AND UNV. DID NOT EXPECT LOW CLDS TO CLEAR
PRIOR TO 00Z ACROSS THE EAST. LLWS WILL CONTINUE TO BE AN ISSUE
FOR A FEW MORE HOURS...ALONG WITH LOW CLDS.
ALSO SOME CHC OF A HEAVY SHOWER...EVEN A RUMBLE OF THUNDER
ACROSS THE FAR WEST.
MDT RIGHT AT FREEZING...TEMP SHOULD SLOWLY EDGE UP FEW
DEGREES THERE THE NEXT FEW HOURS.
21Z TAFS ADJUSTED.
EARLIER DISCUSSION BELOW.
WIDESPREAD IFR WILL CONTINUE UNTIL THE FRONT APPROACHES AND
GUSTY WEST WINDS ALLOW FOR SOME MIXING AND DRYING. THE TIME FRAME
FOR WIDESPREAD IMPROVEMENT WILL BE LATER THIS EVENING AND
OVERNIGHT WITH COLD AIR DAMMING EXPECTED TO HOLD TOUGH FOR THE
REMAINDER OF THE DAYLIGHT HOURS.
BFD/JST ACTUALLY MAY BENEFIT FROM THE DRY SLOT RACING INTO WRN
PA THIS AFTERNOON...POSSIBLY ALLOWING THEM TO QUICKLY SHOOT UP TO
VFR...BUT TIMING THIS IS NEXT TO IMPOSSIBLE AS CLOUDS TEND TO WANT
TO STAY LOCKED IN EAST OF THE MOUNTAINS.
AFTER THE FRONT PASSES WE WILL THEN TRANSITION INTO A FAMILIAR
COLD SEASON PATTERN WHERE WESTERN HIGH TERRAIN REMAINS MVFR/IFR
WITH SCATTERED SNOW SHOWERS...AND MUCH OF THE REMAINDER OF THE
REGION IMPROVES TO VFR.
OUTLOOK...
TONIGHT...COLD FROPA/GUSTY WIND SHIFT TO THE WEST. IMPROVING
CONDITIONS OVER ALL BUT THE WESTERN HIGH TERRAIN.
TUESDAY...MVFR IN -SHSN N/W...VFR E OF MTNS.
WED...MVFR/SNOW SHOWERS NW POSSIBLE. NO SIG WX ELSEWHERE.
THU...MVFR/IFR DEVELOPING WITH POSSIBLE WINTRY MIX OF PRECIP.
FRI...VFR MOST OF THE AREA...BUT MVFR AND IFR ACROSS THE WESTERN
MOUNTAINS WITH SNOW SHOWERS...ESPECIALLY EARLY.
SAT...MAINLY VFR...BUT MVFR POSSIBLE AT JST AND BFD WITH
LOWER CLDS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/GARTNER
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1125 AM CST MON JAN 23 2012
.DISCUSSION.../ISSUED AT 955 AM CST/
SNOW IS NOW WELL TO THE EAST OF OUR AREA LATE THIS MORNING. MAIN
CHALLENGE FOR THE REMAINDER OF THE DAY WILL BE CLOUD COVER AND HOW
QUICKLY WINDS WILL TAPER DOWN. NOW THINKING CLOUDS WILL HOLD FOR
MUCH OF THE DAY...WITH A SOLID STRATUS DECK PRESENTLY HANGING BACK
INTO CENTRAL SOUTH DAKOTA...AND RUC RH TIME SECTIONS INDICATING HIGH
925/850 MB RH HOLDING UNTIL 21Z THEN MOVING OUT FROM WEST TO EAST.
WINDS ARE BEGINNING TO SHOW SIGNS OF DIMINISHING FROM THE WEST...AND
WOULD EXPECT THIS TREND TO CONTINUE THROUGH THE AFTERNOON AS
GRADIENT RELAXES AND COLD AIR ADVECTION TRANSITIONS TO NEUTRAL TO
WARM AIR ADVECTION LATER IN THE AFTERNOON. TEMPERATURES LOOKING TO
BE ON TRACK...REMAINING NEARLY STEADY TO FALLING SLIGHTLY WITH
AFTERNOON READINGS IN THE UPPER TEENS TO LOWER 20S. UPDATES OUT.
&&
.AVIATION.../18Z TAF ISSUANCE/
MVFR CEILINGS WILL PERSIST ACROSS THE AREA THROUGH 21Z...BEFORE
DECREASING FROM THE WEST THROUGH THE EARLY EVENING. BREEZY
NORTHWESTERLY WINDS AND FRESH SNOW COVER WILL RESULT IN REDUCED
VISIBILITIES...IN THE RANGE OF 3 TO 5 SM OVER PORTIONS OF
SOUTHWESTERN MINNESOTA AND NORTHWESTERN IOWA THROUGH THE AFTERNOON.
THESE WINDS WILL DECREASE RAPIDLY AFTER 00Z TONIGHT AS HIGH PRESSURE
BUILDS INTO THE REGION...BECOMING LIGHT AND VARIABLE BY 04Z.
&&
.PREV DISCUSSION.../ISSUED AT 305 AM CST/
SNOW HAS TAPERED OFF TO FLURRIES MOST PLACES EXCEPT FAR EAST
WHERE ANOTHER HALF INCH OF SNOW MAY OCCUR. WILL LEAVE ADVISORY
GOING FAR EAST UNTIL 12Z AND THEN END. WINDS ARE INCREASING TO 20
TO 35 MPH BUT NOT REALLY REDUCING VISIBILITY WITH BLOWING MOST
PLACES AS COLD AIR ADVECTION IS NOT ALL THAT STRONG AND SNOW THAT
FELL HAD A HIGHER MOISTURE CONTENT. SO WILL JUST GO WITH PATCHY
BLOWING SNOW OUTSIDE OF ADVISORY AREA THIS MORNING.
SKIES WILL BE SLOW TO CLEAR ACROSS THE EASTERN CWA TODAY WITH
CYCLONIC FLOW ALOFT...BUT SHOULD BEGIN TO CLEAR ACROSS THE WEST BY
LATE MORNING OR EARLY AFTERNOON. TEMPERATURES ARE LIKELY CLOSE TO
THEIR HIGHS EARLY THIS MORNING AND WILL LIKELY CONTINUE TO FALL
THROUGH 15 OR 16Z AND THEN REBOUND ONLY A FEW DEGREES.
SURFACE HIGH WILL SETTLE OVER CWA TONIGHT AND WITH CLEAR SKIES AND
LIGHT WINDS...TEMPERATURES WILL FALL BELOW ZERO MOST
LOCATION...EXCEPT FAR SOUTHWEST WITH LIGHT RETURN FLOW WILL PROBABLY
KEEP TEMPERATURES FALLING BELOW THE SINGLE DIGITS.
WILL BE A DECENT GRADIENT WITH TEMPERATURES ACROSS THE CWA ON
TUESDAY. LIGHT WINDS AND FRESH SNOW COVER ACROSS THE EAST WILL MAKE
IT HARD TO WARM WITH LACK OF ANY REAL MIXING MECHANISM SO LOWER 20S
MAY BE AS WARM AS IT GETS. SLIGHTLY LITTLE BETTER MIXING ACROSS THE
WEST SHOULD ALLOW HIGHS TO CLIMB INTO THE MID 20S TO LOWER 30S.
WEAK SHORT WAVE WILL MOVE ACROSS CWA TUESDAY NIGHT WITH INCREASING
CLOUDS AHEAD OF THIS SYSTEM TUESDAY AFTERNOON AND NIGHT. WILL LEAVE
FORECAST DRY AS LOW LEVELS REMAIN DRY...BUT COULD SQUEEZE OUT A FEW
FLURRIES OR A TENTH OR TWO OF SNOW WITH THIS FEATURE. CLOUD COVER
WILL ALSO HOLD TEMPERATURE UP TUESDAY NIGHT...ESPECIALLY SOUTH WHERE
SKIES WILL BE MOSTLY CLOUDY THROUGH THE NIGHT.
WARMER WEATHER CAN BE EXPECTED ACROSS THE CWA WEDNESDAY INTO FRIDAY
WITH SNOW COVER KEEPING MOST OF CWA FROM MIXING OUT TO TRUE
POTENTIAL. SHORT WAVE PROGGED TO DROP SOUTHEAST ACROSS CWA ON FRIDAY
AND WILL KEEP SMALL CHANCE OF PRECIPITATION ACROSS SOUTHERN CWA.
MODELS STILL DIFFER ON THIS FEATURE SO NOT CONFIDENT YET IN RAISING
THE SMALL POPS.
WILL SEE COOLER TEMPERATURES NEXT WEEKEND AS COOLER HIGH BUILDS IN
FROM CANADA. NOT AN ARCTIC BLAST...BUT SHOULD COOL TEMPERATURES OFF
AROUND 5 TO 10 DEGREES.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
955 AM CST MON JAN 23 2012
.DISCUSSION...
SNOW IS NOW WELL TO THE EAST OF OUR AREA LATE THIS MORNING. MAIN
CHALLENGE FOR THE REMAINDER OF THE DAY WILL BE CLOUD COVER AND HOW
QUICKLY WINDS WILL TAPER DOWN. NOW THINKING CLOUDS WILL HOLD FOR
MUCH OF THE DAY...WITH A SOLID STRATUS DECK PRESENTLY HANGING BACK
INTO CENTRAL SOUTH DAKOTA...AND RUC RH TIME SECTIONS INDICATING HIGH
925/850 MB RH HOLDING UNTIL 21Z THEN MOVING OUT FROM WEST TO EAST.
WINDS ARE BEGINNING TO SHOW SIGNS OF DIMINISHING FROM THE WEST...AND
WOULD EXPECT THIS TREND TO CONTINUE THROUGH THE AFTERNOON AS
GRADIENT RELAXES AND COLD AIR ADVECTION TRANSITIONS TO NEUTRAL TO
WARM AIR ADVECTION LATER IN THE AFTERNOON. TEMPERATURES LOOKING TO
BE ON TRACK...REMAINING NEARLY STEADY TO FALLING SLIGHTLY WITH
AFTERNOON READINGS IN THE UPPER TEENS TO LOWER 20S. UPDATES OUT.
&&
.PREV DISCUSSION.../ISSUED AT 305 AM CST/
SNOW HAS TAPERED OFF TO FLURRIES MOST PLACES EXCEPT FAR EAST
WHERE ANOTHER HALF INCH OF SNOW MAY OCCUR. WILL LEAVE ADVISORY
GOING FAR EAST UNTIL 12Z AND THEN END. WINDS ARE INCREASING TO 20
TO 35 MPH BUT NOT REALLY REDUCING VISIBILITY WITH BLOWING MOST
PLACES AS COLD AIR ADVECTION IS NOT ALL THAT STRONG AND SNOW THAT
FELL HAD A HIGHER MOISTURE CONTENT. SO WILL JUST GO WITH PATCHY
BLOWING SNOW OUTSIDE OF ADVISORY AREA THIS MORNING.
SKIES WILL BE SLOW TO CLEAR ACROSS THE EASTERN CWA TODAY WITH
CYCLONIC FLOW ALOFT...BUT SHOULD BEGIN TO CLEAR ACROSS THE WEST BY
LATE MORNING OR EARLY AFTERNOON. TEMPERATURES ARE LIKELY CLOSE TO
THEIR HIGHS EARLY THIS MORNING AND WILL LIKELY CONTINUE TO FALL
THROUGH 15 OR 16Z AND THEN REBOUND ONLY A FEW DEGREES.
SURFACE HIGH WILL SETTLE OVER CWA TONIGHT AND WITH CLEAR SKIES AND
LIGHT WINDS...TEMPERATURES WILL FALL BELOW ZERO MOST
LOCATION...EXCEPT FAR SOUTHWEST WITH LIGHT RETURN FLOW WILL PROBABLY
KEEP TEMPERATURES FALLING BELOW THE SINGLE DIGITS.
WILL BE A DECENT GRADIENT WITH TEMPERATURES ACROSS THE CWA ON
TUESDAY. LIGHT WINDS AND FRESH SNOW COVER ACROSS THE EAST WILL MAKE
IT HARD TO WARM WITH LACK OF ANY REAL MIXING MECHANISM SO LOWER 20S
MAY BE AS WARM AS IT GETS. SLIGHTLY LITTLE BETTER MIXING ACROSS THE
WEST SHOULD ALLOW HIGHS TO CLIMB INTO THE MID 20S TO LOWER 30S.
WEAK SHORT WAVE WILL MOVE ACROSS CWA TUESDAY NIGHT WITH INCREASING
CLOUDS AHEAD OF THIS SYSTEM TUESDAY AFTERNOON AND NIGHT. WILL LEAVE
FORECAST DRY AS LOW LEVELS REMAIN DRY...BUT COULD SQUEEZE OUT A FEW
FLURRIES OR A TENTH OR TWO OF SNOW WITH THIS FEATURE. CLOUD COVER
WILL ALSO HOLD TEMPERATURE UP TUESDAY NIGHT...ESPECIALLY SOUTH WHERE
SKIES WILL BE MOSTLY CLOUDY THROUGH THE NIGHT.
WARMER WEATHER CAN BE EXPECTED ACROSS THE CWA WEDNESDAY INTO FRIDAY
WITH SNOW COVER KEEPING MOST OF CWA FROM MIXING OUT TO TRUE
POTENTIAL. SHORT WAVE PROGGED TO DROP SOUTHEAST ACROSS CWA ON FRIDAY
AND WILL KEEP SMALL CHANCE OF PRECIPITATION ACROSS SOUTHERN CWA.
MODELS STILL DIFFER ON THIS FEATURE SO NOT CONFIDENT YET IN RAISING
THE SMALL POPS.
WILL SEE COOLER TEMPERATURES NEXT WEEKEND AS COOLER HIGH BUILDS IN
FROM CANADA. NOT AN ARCTIC BLAST...BUT SHOULD COOL TEMPERATURES OFF
AROUND 5 TO 10 DEGREES.
&&
.AVIATION.../12Z TAF ISSUANCE/
AN MVFR DECK OF CLOUDS WILL PLAGUE THE TAF SITES THIS
MORNING...UNDER THE INFLUENCE OF CYCLONIC FLOW. SOME MINOR
VISIBILITY RESTRICTIONS DUE TO LIGHT SNOW AND BLOWING SNOW OVER
FAR ERN SD...NW IA AND SW MN THIS MORNING...BUT THAT SHOULD OCCUR
TO THE EAST OF THE TAF SITES FOR THE MOST PART. THINK IT WILL BE
AFTER 18Z BEFORE NOTABLE CLEARING IS SEEN AT KHON...AND UNTIL
CLOSER TO 21Z FOR KFSD AND KSUX BEFORE CIGS BREAK OUT. BY
00Z...MOSTLY CLEAR SKIES SHOULD BE PREVALENT...ALONG WITH A
SIGNIFICANT REDUCTION IN WIND SPEEDS AS HIGH PRESSURE SETTLES IN.
WINDS WILL BECOME LIGHT AND VARIABLE AFTER MIDNIGHT...WITH ONLY
FLEETING CIRRUS EXPECTED IN THE WAY OF ANY CLOUD COVER OVERNIGHT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
MN...NONE.
NE...NONE.
SD...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1058 PM CST SUN JAN 22 2012
.DISCUSSION.../ISSUED AT 735 PM CST/
A COMBINATION OF FACTORS HAS DECREASED THE HAZARDOUS WINTER WEATHER
THREAT FOR MUCH OF THE AREA...NAMELY WEST AND NORTH. LESSER SUPPORT
FOR SNOW ESPECIALLY ANYTHING BEYOND QUITE LIGHT SNOW SEEMS OBVIOUS.
SLIGHTLY LESSER WINDS THAN EARLIER EXPECTED ALONG WITH TEMPERATURES
AND EVEN DEWPOINTS GOING TO FREEZING OR ABOVE EARLY THIS EVENING IN
THE SOUTHWEST WHERE THE STRONGEST WINDS HAVE BEEN BLOWING ALL MEAN
THAT A WINTER WX ADVISORY SEEMS NO LONGER NEEDED. HOWEVER THE SYSTEM
IS TAKING BETTER DEFINITION IN OUR SOUTHEAST AREA INCLUDING
NORTHWEST IOWA SO WILL KEEP THE ADVISORY THERE...AND FOR NOW WILL
KEEP THROUGH NOON MONDAY ALTHOUGH NOT SURE IF BLOWING SNOW WILL BE
BAD ENOUGH.ASIDE FROM THAT BIT OF WARMING WITH THE MIXING
TEMPERATURES NOT TOO BAD...MAY WIND UP SLIGHTLY LESS COLD BUT WILL
CERTAINLY FALL TOWARD MORNING. AMOUNTS IN REMAINING ADVISORY AREA
SHOULD BE 2 TO 3 INCHES BUT THERE COULD BE SOME PLACES WITH A BIT
MORE. / WILLIAMS
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
MVFR-IFR CONDITIONS WITH AREAS OF SNOW WILL CONTINUE THROUGH THE
OVERNIGHT...AS LEADING BAND OF HEAVIER SNOW MOVES THROUGH FAR
EASTERN PARTS OF THE AREA...AND OCCASIONAL LIGHTER SNOW FOLLOWS
BEHIND. CONDITIONS EXPECTED TO GRADUALLY IMPROVE WEST TO EAST AFTER
10Z-12Z...WITH VFR CONDITIONS EXPECTED MOST AREAS BY LATE MONDAY
AFTERNOON. NORTHWEST WINDS OCCASIONALLY GUSTING 25-30KTS INTO JAMES
VALLEY AS OF 05Z AND WILL CONTINUE TO EXPAND EAST THROUGH THE
OVERNIGHT HOURS...ADDING TO VISIBILITY REDUCTION IN BLOWING SNOW.
THIS SHOULD ABATE AS WINDS DECREASE IN THE LATE MORNING/AFTERNOON
MONDAY.
&&
.PREV DISCUSSION.../ISSUED AT 336 PM CST/
CHALLENGE IS AT HIGH LEVEL WITH SYSTEM IN THE SHORT TERM...DEALING
WITH A HEALTHY SPLIT FLOW. WATER VAPOR IMAGERY SHOWING FULL LATITUDE
TROUGH PUSH ACROSS THE CENTRAL U.S...WITH SEVERAL PIECES OF ENERGY.
FIRST HAS MOVED PAST AND INTO NORTHWEST MN...SECOND IS LIFTING
THROUGH CENTRAL NEBRASKA...AND THIRD /THE STRONGEST/ LIFTING AROUND
THE BASE IN SOUTHERN KS. THE LATTER WILL DRIVE INTENSE CYCLOGENESIS
WELL EAST OF THE AREA LATER TONIGHT AND MONDAY WITH ITS OWN IMPACT
BEING WINDS...BUT FOCUS WILL BE ON THE MID FEATURE FOR THE EVENING.
LEADING BOUNDARY/INVERTED TROUGH NOW SHIFTED TO NEAR A KRWF TO KSUX
LINE...AND COLLAPSING SOUTHEAST AS ENERGY IN SOUTHERN TROUGH LIFTS
NORTHWARD. TEMPS AHEAD ACROSS NORTHWEST IOWA AREA ALL AT OR ABOVE
FREEZING NOW...WITH THE ONLY AREA STILL HAVING SOME PATCHY FREEZING
DRIZZLE FAR EASTERN SECTIONS OF SW MN AROUND KMWM/KMJQ/KOTG.
SNOWFALL ACROSS MUCH OF THE STATE OTHER THAN THE FAR SOUTHEAST AT
MID AFTERNOON...IN BROAD DIV Q ASSOCIATED WITH THE TROUGH.
PRECIPITATION IS ALSO BREAKING OUT ALONG THE LEADING PV SUPPORT
THROUGH NEBRASKA INTO SOUTHEAST SOUTH DAKOTA. EARLIER MINOR WARM
NOTCH NOTED ON MORNING RAOBS HAS APPARENTLY BEEN WORKED OUT
WITH PRECIPITATION ALL SNOW AT YANKTON PER LATEST WEBCAM IMAGE.
SHORT RANGE MODELS FAIL ON QPF BEING IN THE RIGHT PLACE...BUT HAVE
LESSER PROBLEMS WITH THE DYNAMICS IN MOST...ESPECIALLY IN PLACEMENT
OF THE SIGNIFICANT PV FEATURES. CLOSELY FOLLOWED RUC/NAM ON
THESE...AND RESULT WAS A QUICKER EASTWARD DEVELOPMENT ALONG THE PV
ADVECTION. QUICK PEEK AT LATEST HRRR WOULD SUGGEST THE PROGRESSION
MAY BE EVEN GREATER...AS WILL BE DEMISE OF THE WESTERN SNOW AREA IN
FAVOR OF THIS DEVELOPMENT ACROSS NEBRASKA.
THERMODYNAMICALLY...THIS IS FAR FROM THE MOST EFFICIENT PROFILE WITH
MUCH OF THE LOWER PROFILES IN THE -5 TO -8C RANGE...AND THE LIFT
FAIRLY HIGH. DENDRITIC DEPTH IS LESS THAN 100 HPA...AND REALLY DO
NOT NOTE ANY SIGNIFICANT INSTABILITY TO MAKE USE OF UNTIL MID TO
LATE EVENING WITH SOME APPEARING ABOVE OF MID LEVEL FRONT...SO LOOKS
MORE OF A BROAD AND LESSER FOCUSED EVENT UNTIL BAND DEVELOPS TOWARD
THE EAST. HOWEVER...FAIRLY QUICK PERIOD OF DYNAMIC/THERMODYNAMIC
OVERLAP...SO ANY ENHANCEMENT SHOULD BE SOMEWHAT SHORT TERM...BUT
COULD GET A LITTLE TIME BOOST BY THE SLOWING OF FEATURES DURING MID
LEVEL DEVELOPMENT TO EAST. IMPACT OVERALL WAS TO LOWER SNOWFALL
AMOUNTS BY AN INCH OR SO WEST...AND RAISE BY A HALF INCH TO INCH IN
THE EAST. WHILE MOST...IF NOT ALL OF THE AREA IS LIKELY TO STAY AT
OR BELOW SNOWFALL CRITERIA FOR AN ADVISORY... IT WILL BE THE
COMBINATION OF THE SNOW AND BLOWING SNOW THAT SUPPORTS THE ADVISORY.
THIS INCLUDES AREAS FARTHER EASTWARD WHICH RECEIVED SOME HEAVIER
SNOWFALL IN LAST EVENT. MAIN PUSH OF WINDS LOOKS TO GET GOING IN
THE FAR WEST LATE AFTERNOON TO EARLY EVENING...TOWARD THE I29
CORRIDOR TOWARD MIDNIGHT...SW MN BETWEEN 06Z AND 09Z. APPEARS THAT
GUSTY 20 TO 35 MPH WIND CAN BE EXPECTED AFTER INITIAL PRESSURE RISE
SURGE...AND MORE TYPICAL THROUGH THE EAST BY MONDAY AS THE CYCLONE
STRENGTHENS TO THE EAST. CONTINUED CURRENT ADVISORY...BUT DID EXTEND
THE END TIME TO COVER THE STRONGER WINDS. ADDITIONAL AREA WAS ADDED
OVER THE REMAINDER OF THE AREA FOR THE SNOW/WIND THREAT...BUT
STARTED AS ONE GROUP RATHER THAN PIECEMEAL TO KEEP IT SIMPLE...AND
TO PICK UP ANY LINGERING FREEZING DRIZZLE IN THE FAR EAST.
ON MONDAY...CONDITIONS WILL IMPROVE SOMEWHAT OUTSIDE ANY LINGERING
SNOWFALL WHICH IS LIMITED TO THE FAR EASTERN AREA AS UPPER LOW
DEVELOPS TO THE EAST. THIS DEVELOPMENT WILL KEEP THE GRADIENT
HOLDING ON STRONG THROUGH SW MN AND INTO NW IA THROUGH AT LEAST
MIDDAY IF NOT MID AFTERNOON. FOR THIS REASON...CONTINUED ADVISORY TO
COVER THE BLOWING SNOW POTENTIAL IN THE EASTERN GROUP. TEMPERATURES
LIKELY TO STRUGGLE WITH FRESH SNOW AND MIXED START...SO DO NOT LOOK
FOR MORE THAN A 4-6 DEGREE CLIMB AS SURFACE RIDGE FROM WEST FINALLY
STARTS TO DROP OFF THE WINDS IN THE WEST DURING THE AFTERNOON.
/CHAPMAN
BRISK NORTHWEST WINDS TAPER OFF BY MONDAY NIGHT...AS THE LOW MOVES
WELL EAST OF THE FORECAST AREA AND ARCTIC HIGH PRESSURE SLIPS INTO
THE REGION. WITH A FRESH SNOWPACK...MOSTLY CLEAR SKIES AND WINDS
BECOMING LIGHT...TEMPERATURES SHOULD PLUMMET OVERNIGHT. CONTINUED TO
GO WELL BELOW GUIDANCE WHICH IS NOTORIOUS FOR BEING TOO WARM IN
THESE EVENTS. LOWS SHOULD FALL INTO THE LOWER TEENS AND SINGLE
DIGITS BELOW ZERO.
HIGH PRESSURE SHIFTS EASTWARD ON TUESDAY WHILE THE UPPER FLOW
BECOMES MORE ZONAL. MODEST WARM AIR ADVECTION WILL ALLOW
TEMPERATURES TO IMPROVE INTO THE 20S TO LOWER 30S. A WEAK UPPER
LEVEL WAVE SLIDES THROUGH THE REGION TUESDAY NIGHT WITH LITTLE
IMPACT OTHER THAN AN INCREASE IN CLOUDS.
THE MILDER PATTERN CONTINUE INTO FRIDAY WITH WEST AND SOUTHWEST
WINDS AND LOW LEVEL TEMPERATURES NEAR OR ABOVE FREEZING. EVEN WITH
925 MB TEMPERATURES AS WARM AS +6 OR +8C...IT WILL BE DIFFICULT TO
MIX TO THE SURFACE WITH THE RECENT SNOWPACK IN PLACE. HOWEVER...DO
EXPECT HIGHS TO RISE BACK ABOVE AVERAGE AND HOVER IN THE LOWER TO
MID 30S FOR MUCH OF THE FORECAST AREA. AGAIN...WENT A BIT BELOW
GUIDANCE NUMBERS DURING THE PERIOD WITH THIS IN MIND. A MID LEVEL
WAVE SLIPS ACROSS THE MISSOURI RIVER AREA THURSDAY NIGHT AND EARLY
FRIDAY WITH MEAGER MOISTURE AND LIFT. COULD SQUEEZE OUT A LITTLE
LIGHT PRECIPITATION ACROSS THE SOUTH SO WILL LEAVE MENTION OF A
SLIGHT CHANCE. A REINFORCING SHOT OF COOLER AIR WILL FOLLOW FRIDAY
NIGHT AND SATURDAY WITH BRISK NORTHWEST WINDS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL NOON CST MONDAY FOR
IAZ001>003-012>014-020>022-031-032.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST MONDAY FOR
MNZ080-081-089-090.
NE...WINTER WEATHER ADVISORY UNTIL NOON CST MONDAY FOR
NEZ013-014.
SD...WINTER WEATHER ADVISORY UNTIL NOON CST MONDAY FOR
SDZ070-071.
&&
$$
WILLIAMS
AREA FORECAST DISCUSSION
NWS SPOKANE WA
846 AM PST Mon Jan 23 2012
.SYNOPSIS...Snow showers will linger over the central and
southern Idaho Panhandle this morning as a weak cold front exits
the region. The rest of the Inland Northwest will experience dry
conditions today and tonight. The next storm system will bring
another round of wintry weather Tuesday. Warmer conditions are
expected Wednesday and Thursday with snow levels above the valley
floors.
&&
.DISCUSSION...
Updated the forecast to take down the Winter Weather Advisory for
Idaho zone 4. Radar shows the backedge of the snow shield has
exited the region followed by clearing of the high clouds. Little
wind and abundant low level moisture has lead to stratus and
fog...locally dense. The Dense Fog Advisory will continue through
10am, although the HRRR models suggests the fog may persist a
little longer. /rfox.
&&
.AVIATION...
12Z TAFS: Cold front will continue to sag to the southeast of the
KPUW and KLWS taf sites through the morning hours with the threat of
precip diminishing. The main concern for today is the fog and low
stratus that has developed in the wake of this system. This
fog/stratus is expect to hang around through at least the early
afternoon hours. We should then see this fog/stratus lift and
scatter out by the late afternoon. Winds will shift to out of the
east tonight with moisture likely to pool up across the western
basin. As a result, KMWH and KEAT will see the best chance low
stratus and fog continuing or redeveloping tonight into tomorrow
morning. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 33 19 33 33 41 35 / 10 0 40 80 30 60
Coeur d`Alene 34 18 34 31 42 35 / 10 0 30 80 50 80
Pullman 34 23 37 33 45 39 / 10 0 30 90 40 70
Lewiston 41 25 40 37 49 41 / 10 0 20 80 30 60
Colville 35 19 33 31 40 32 / 10 10 60 80 40 70
Sandpoint 34 21 34 31 41 35 / 10 0 30 80 60 80
Kellogg 34 20 32 32 42 35 / 10 0 20 90 70 90
Moses Lake 32 18 32 32 42 35 / 0 0 90 30 20 30
Wenatchee 27 20 30 30 37 36 / 0 0 90 20 20 30
Omak 32 18 30 27 39 29 / 10 10 80 20 20 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Dense Fog Advisory until 10 AM PST this morning for Moses Lake
Area-Upper Columbia Basin-Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
845 PM CST TUE JAN 24 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
300 PM CST TUE JAN 24 2012
MAIN FORECAST CONCERN IS ON SNOW CHANCES LATE TONIGHT INTO WEDNESDAY
MORNING AND THE POSSIBILITY OF SOME MIXED PRECIPITATION...THEN
MAINLY CLOUDS AND TEMPERATURES.
18Z SURFACE ANALYSIS SHOWS HIGH PRESSURE EXTENDING FROM SOUTHERN
ILLINOIS...NORTHWARD INTO SOUTHERN AND CENTRAL MINNESOTA. ONE BAND
OF STATUS MOVED EAST OF THE AREA THIS MORNING...BUT VISIBLE
SATELLITE IMAGERY AND SURFACE REPORTS SHOW ANOTHER AREA OF STRATUS
OVER SOUTHEAST MINNESOTA AND NORTHERN IOWA AS THE MOISTURE IS
TRAPPED UNDER THE SUBSIDENCE INVERSION.
24.12Z MODELS OFFER SIMILAR SOLUTIONS THROUGH THE PERIOD. THERE ARE
SOME MINOR DIFFERENCES...ESPECIALLY IN THE LATER PERIODS WITH THE
STRENGTH OF THE 500MB LOW THAT MOVES ACROSS SOUTHERN CANADA.
DIFFERENCES SUBTLE ENOUGH TO USE A BLEND APPROACH. OVERALL...MAINLY
ZONAL LOW INITIALLY WILL SLOWLY TRANSITIONS TO A MORE NORTHWESTERLY
FLOW BY THURSDAY AND FRIDAY AS UPPER LOW TRANSLATES ACROSS
SOUTHERN CANADA.
IN THE NEAR TERM...ANY BREAK IN THE CLOUDS WILL BE SHORT LIVED
TONIGHT AS SHORTWAVE TROUGH CROSSES THE PLAINS. THIS WILL SPREAD
CLOUDS BACK INTO THE AREA THIS EVENING. MODELS HAVE BEEN
CONSISTENT IN A WEAK AREA OF ISENTROPIC LIFT ACROSS THE WEST AND
NORTH LATE TONIGHT/EARLY WEDNESDAY. VERY WEAK QG
CONVERGENCE...MAINLY ABOVE 700MB AFFECTS THE AREA WITH THE WAVE.
MODELS HAVE BEEN PAINTING SOME VERY LIGHT QPF FROM SOUTHEAST
MINNESOTA INTO NORTH CENTRAL WISCONSIN. BUFKIT SOUNDINGS ALSO
SHOWING A 925MB-875MB WARM NOSE PUSHING INTO SOUTHEAST MINNESOTA
AFTER 09Z. NAM A BIT MORE AGGRESSIVE WITH +1 TO +2 CELSIUS
TEMPERATURES IN THE WARM LAYER...AND GFS CLOSER TO 0 TO +1
CELSIUS. HOWEVER..24.18Z RUC COOLS LAYER BEFORE PRECIPITATING AND
THUS KEEPS IT ALL SNOW. THIS COULD POSE A PRECIPITATION TYPE
PROBLEM...HOWEVER THE PRESENCE OF DRY AIR WILL LIKELY COOL COLUMN
ONCE PRECIPITATION BEGINS PER THE RUC...AND THUS HAVE LEFT IT ALL
SNOW. EVENING SHIFT WILL HAVE TO MONITOR THOUGH FOR THE
POSSIBILITY OF SOME SLEET WITH THE SNOW LATE TONIGHT. DID RAISE
PROBABILITIES A LITTLE TONIGHT...THINKING IT WILL BE MAINLY A NON
ACCUMULATING EVENT...SO ONLY WENT WITH CHANCE PROBABILITIES.
WEDNESDAY THROUGH THURSDAY LOOK QUIET WITH JUST SOME MID CLOUDS
FROM TIME TO TIME. WITH A STRONGER SOUTHWEST LOW LEVEL FLOW AND
925MB TEMPERATURES WARMING TO +1 TO +2 CELSIUS...TEMPERATURES LOOK
TO BE ON THE MILDER SIDE WITH READINGS BACK ABOVE NORMAL. WINDS DO
BECOME MORE WESTERLY THURSDAY AS A TROUGH ROTATES THROUGH THE
AREA...BUT LITTLE IN THE WAY OF COOLING BEHIND IT AND THUS EXPECT
TEMPERATURES TO REMAIN MILD. GIVEN THE SNOW COVER DID NOT GO AS
WARM AS GUIDANCE...BUT WILL SEE READINGS IN THE LOWER TO MIDDLE
30S EACH DAY AND MIDDLE 20S OVERNIGHT.
BY FRIDAY AND FRIDAY NIGHT...A SHORTWAVE ROTATES AROUND THE SOUTHERN
CANADA UPPER LOW WITH AN ASSOCIATED COLD FRONT. BOTH THE GFS AND
ECMWF IS SHOWING SOME WEAK FORCING ACROSS THE AREA AND DID GO WITH
SOME LOWER END SNOW PROBABILITIES.
.LONG TERM...SATURDAY THROUGH TUESDAY
300 PM CST TUE JAN 24 2012
LONGWAVE TROUGH GETS CARVED OUT OF THE FLOW AS 500MB LOW DEEPENS
ACROSS SOUTHERN CANADA SATURDAY AND SUNDAY. THIS WILL ALLOW COLDER
AIR TO FILTER INTO THE AREA...WITH TEMPERATURES FALLING BACK TO
BELOW NORMAL READINGS FOR A BRIEF PERIOD OF TIME. A SHORTWAVE
ROTATING THROUGH THE FLOW MAY BRING SOME LIGHT SNOW CHANCES IN AREAS
NORTH OF INTERSTATE 94 SATURDAY...WITH THE REMAINDER OF THE AREA
REMAINING DRY. TROUGH DOES BEGIN TO PUSH EAST SUNDAY...WITH HEIGHTS
BEGINNING TO RISE ON MONDAY AND TUESDAY. TEMPERATURES WILL MODERATE
MONDAY AND TUESDAY...WITH A DISTURBANCE RIDING DOWN THE FLOW
TUESDAY BRING A CHANCE OF RAIN OR SNOW...AS TEMPERATURES REBOUND
INTO THE MIDDLE 30S.
&&
.AVIATION...TONIGHT AND THURSDAY
845 PM CST TUE JAN 24 2012
STRATUS DECK THAT WAS ACROSS MUCH OF SOUTHERN MINNESOTA AND
NORTHERN IOWA HAS BEEN UNEXPECTEDLY CLEARING OUT DURING THE PAST
TWO HOURS. TWO POTENTIAL REASONS INCLUDE THE ALTOSTRATUS AND
CIRROSTRATUS COVER MOVING ACROSS...AND PERHAPS MORE LIKELY A
SOUTHERLY FLOW DEVELOPING WHICH IS BRINGING DRIER AIR NORTH FROM
SOUTHERN IOWA. AS A RESULT OF THIS CLEARING TREND...HAVE NOW
INCLUDED A PERIOD BETWEEN 04-09Z OF VFR CONDITIONS AT KRST...ALONG
WITH BRINGING CEILINGS UP TO MVFR FOR THE LIGHT SNOW PERIOD
BETWEEN 09-13Z. MAINTAINED THE MVFR BR AT KRST AS WELL FROM 09-18Z
SINCE THERE ARE STILL OBSERVATIONS OF THIS IN SOUTHWEST MINNESOTA.
REGARDING KLSE...STILL ANTICIPATING THE STRATUS TO MOVE IN SHORTLY...
GIVEN OBSERVATIONS OF OVC MVFR AT WINONA AND SCT MVFR STRATUS AT
VIROQUA AND BOSCOBEL. AN INCREASING SOUTH WIND LATE WEDNESDAY
MORNING THROUGH THE AFTERNOON SHOULD HELP TO BRING IN DRIER AIR
FROM SOUTHEAST IOWA INTO THE TAF SITES...BRINGING CONDITIONS UP
TO VFR.
LAST ITEM TO NOTE IS A BAND OF PRECIPITATION OVER NORTHWEST IOWA.
CONSENSUS IS THAT THIS AREA OF PRECIPITATION WILL SLOWLY DISSIPATE
AS IT COMES ACROSS THE TAF SITES LATE TONIGHT INTO WEDNESDAY
MORNING. TYPE LOOKS TO BE MOSTLY SNOW...IMPACTING KRST BETWEEN
09-15Z AND KLSE BETWEEN 11-18Z. ACCUMULATIONS WILL BE VERY
LIGHT...BETWEEN A TRACE AND A FEW TENTHS OF AN INCH. LITTLE
RESTRICTION TO VISIBILITY EXPECTED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 PM CST TUE JAN 24 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
536 PM CST TUE JAN 24 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
300 PM CST TUE JAN 24 2012
MAIN FORECAST CONCERN IS ON SNOW CHANCES LATE TONIGHT INTO WEDNESDAY
MORNING AND THE POSSIBILITY OF SOME MIXED PRECIPITATION...THEN
MAINLY CLOUDS AND TEMPERATURES.
18Z SURFACE ANALYSIS SHOWS HIGH PRESSURE EXTENDING FROM SOUTHERN
ILLINOIS...NORTHWARD INTO SOUTHERN AND CENTRAL MINNESOTA. ONE BAND
OF STATUS MOVED EAST OF THE AREA THIS MORNING...BUT VISIBLE
SATELLITE IMAGERY AND SURFACE REPORTS SHOW ANOTHER AREA OF STRATUS
OVER SOUTHEAST MINNESOTA AND NORTHERN IOWA AS THE MOISTURE IS
TRAPPED UNDER THE SUBSIDENCE INVERSION.
24.12Z MODELS OFFER SIMILAR SOLUTIONS THROUGH THE PERIOD. THERE ARE
SOME MINOR DIFFERENCES...ESPECIALLY IN THE LATER PERIODS WITH THE
STRENGTH OF THE 500MB LOW THAT MOVES ACROSS SOUTHERN CANADA.
DIFFERENCES SUBTLE ENOUGH TO USE A BLEND APPROACH. OVERALL...MAINLY
ZONAL LOW INITIALLY WILL SLOWLY TRANSITIONS TO A MORE NORTHWESTERLY
FLOW BY THURSDAY AND FRIDAY AS UPPER LOW TRANSLATES ACROSS
SOUTHERN CANADA.
IN THE NEAR TERM...ANY BREAK IN THE CLOUDS WILL BE SHORT LIVED
TONIGHT AS SHORTWAVE TROUGH CROSSES THE PLAINS. THIS WILL SPREAD
CLOUDS BACK INTO THE AREA THIS EVENING. MODELS HAVE BEEN
CONSISTENT IN A WEAK AREA OF ISENTROPIC LIFT ACROSS THE WEST AND
NORTH LATE TONIGHT/EARLY WEDNESDAY. VERY WEAK QG
CONVERGENCE...MAINLY ABOVE 700MB AFFECTS THE AREA WITH THE WAVE.
MODELS HAVE BEEN PAINTING SOME VERY LIGHT QPF FROM SOUTHEAST
MINNESOTA INTO NORTH CENTRAL WISCONSIN. BUFKIT SOUNDINGS ALSO
SHOWING A 925MB-875MB WARM NOSE PUSHING INTO SOUTHEAST MINNESOTA
AFTER 09Z. NAM A BIT MORE AGGRESSIVE WITH +1 TO +2 CELSIUS
TEMPERATURES IN THE WARM LAYER...AND GFS CLOSER TO 0 TO +1
CELSIUS. HOWEVER..24.18Z RUC COOLS LAYER BEFORE PRECIPITATING AND
THUS KEEPS IT ALL SNOW. THIS COULD POSE A PRECIPITATION TYPE
PROBLEM...HOWEVER THE PRESENCE OF DRY AIR WILL LIKELY COOL COLUMN
ONCE PRECIPITATION BEGINS PER THE RUC...AND THUS HAVE LEFT IT ALL
SNOW. EVENING SHIFT WILL HAVE TO MONITOR THOUGH FOR THE
POSSIBILITY OF SOME SLEET WITH THE SNOW LATE TONIGHT. DID RAISE
PROBABILITIES A LITTLE TONIGHT...THINKING IT WILL BE MAINLY A NON
ACCUMULATING EVENT...SO ONLY WENT WITH CHANCE PROBABILITIES.
WEDNESDAY THROUGH THURSDAY LOOK QUIET WITH JUST SOME MID CLOUDS
FROM TIME TO TIME. WITH A STRONGER SOUTHWEST LOW LEVEL FLOW AND
925MB TEMPERATURES WARMING TO +1 TO +2 CELSIUS...TEMPERATURES LOOK
TO BE ON THE MILDER SIDE WITH READINGS BACK ABOVE NORMAL. WINDS DO
BECOME MORE WESTERLY THURSDAY AS A TROUGH ROTATES THROUGH THE
AREA...BUT LITTLE IN THE WAY OF COOLING BEHIND IT AND THUS EXPECT
TEMPERATURES TO REMAIN MILD. GIVEN THE SNOW COVER DID NOT GO AS
WARM AS GUIDANCE...BUT WILL SEE READINGS IN THE LOWER TO MIDDLE
30S EACH DAY AND MIDDLE 20S OVERNIGHT.
BY FRIDAY AND FRIDAY NIGHT...A SHORTWAVE ROTATES AROUND THE SOUTHERN
CANADA UPPER LOW WITH AN ASSOCIATED COLD FRONT. BOTH THE GFS AND
ECMWF IS SHOWING SOME WEAK FORCING ACROSS THE AREA AND DID GO WITH
SOME LOWER END SNOW PROBABILITIES.
.LONG TERM...SATURDAY THROUGH TUESDAY
300 PM CST TUE JAN 24 2012
LONGWAVE TROUGH GETS CARVED OUT OF THE FLOW AS 500MB LOW DEEPENS
ACROSS SOUTHERN CANADA SATURDAY AND SUNDAY. THIS WILL ALLOW COLDER
AIR TO FILTER INTO THE AREA...WITH TEMPERATURES FALLING BACK TO
BELOW NORMAL READINGS FOR A BRIEF PERIOD OF TIME. A SHORTWAVE
ROTATING THROUGH THE FLOW MAY BRING SOME LIGHT SNOW CHANCES IN AREAS
NORTH OF INTERSTATE 94 SATURDAY...WITH THE REMAINDER OF THE AREA
REMAINING DRY. TROUGH DOES BEGIN TO PUSH EAST SUNDAY...WITH HEIGHTS
BEGINNING TO RISE ON MONDAY AND TUESDAY. TEMPERATURES WILL MODERATE
MONDAY AND TUESDAY...WITH A DISTURBANCE RIDING DOWN THE FLOW
TUESDAY BRING A CHANCE OF RAIN OR SNOW...AS TEMPERATURES REBOUND
INTO THE MIDDLE 30S.
&&
.AVIATION...TONIGHT AND WEDNESDAY
536 PM CST TUE JAN 24 2012
STRATUS DECK REMAINS ACROSS MUCH OF SOUTHERN MINNESOTA AND
NORTHERN IOWA...WITH CEILINGS RANGING FROM IFR TO MVFR. THIS DECK
HAS BEEN MOVING VERY SLOWLY TO THE EAST THE LAST FEW HOURS.
ANTICIPATING KRST TO HOLD AT THE CURRENT MVFR...THEN FALL WITHIN A
COUPLE HOURS TO IFR...GIVEN IFR CEILINGS ALREADY PRESENT AT DODGE
CENTER AND AUSTIN. FOR KLSE...FOLLOWING A LINEAR EXTRAPOLATION
YIELDS AROUND 02Z FOR THE MVFR STRATUS TO MOVE IN THERE. CURRENT
THINKING IS THAT THE STRATUS WILL HOLD IN PLACE THROUGH THE NIGHT
WITH CEILINGS SLOWLY LOWERING. THE LOWERING CEILINGS IS IN
RESPONSE TO A STRONGER WEST WIND THAT DEVELOPS BETWEEN 1000-3000
FT...BRINGING CURRENT IFR CEILINGS OVER SOUTHWEST MINNESOTA
EASTWARD. DO NOT HAVE KLSE FALLING BELOW MVFR...THINKING THE
VALLEY IMPACT SHOULD KEEP THE CEILING UP...BUT THAT IS CERTAINLY
SOMETHING TO WATCH. ANOTHER PROBLEM IS VISIBILITIES. MVFR
VISIBILITIES PRESENT OVER SOUTHWEST MINNESOTA SHOULD ADVECT
EASTWARD TOO...REACHING KRST AROUND 09Z. NOT SURE YET IF IT WILL
IMPACT KLSE. AN INCREASING SOUTH WIND LATE WEDNESDAY MORNING
THROUGH THE AFTERNOON SHOULD HELP TO BRING IN DRIER AIR FROM
SOUTHEAST IOWA INTO THE TAF SITES...BRINGING CONDITIONS UP TO VFR.
LAST ITEM TO NOTE IS A BAND OF PRECIPITATION LIKELY TO FORM THIS
EVENING OVER NORTHWEST IOWA AND SOUTHWEST MINNESOTA. CONSENSUS IS
THAT THIS AREA OF PRECIPITATION WILL SLOWLY DISSIPATE AS IT COMES
ACROSS THE TAF SITES LATE TONIGHT INTO WEDNESDAY MORNING. TYPE
LOOKS TO BE MOSTLY SNOW...IMPACTING KRST BETWEEN 09-15Z AND KLSE
BETWEEN 11-18Z. ACCUMULATIONS WILL BE VERY LIGHT...BETWEEN A TRACE
AND A FEW TENTHS OF AN INCH. LITTLE RESTRICTION TO VISIBILITY
EXPECTED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 PM CST TUE JAN 24 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1218 PM CST MON JAN 23 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
245 AM CST MON JAN 23 2012
FORECAST CONCERNS FOCUS ON THE SNOW THIS MORNING.
LATEST WATERVAPOR IMAGERY DEPICTED AN UPPER LEVEL SHORTWAVE TROUGH
CHURNING ACROSS THE SOUTHERN PLAINS...WHILE AT THE SFC A LOW WAS
LOCATED OVER NORTHERN MO. 88-D RADAR IMAGERY SHOWED AREAS OF PCPN
SPREADING FROM THE DAKOTAS ACROSS MN/IA...AND ACROSS SOUTHERN WI AND
ILL. WHAT WAS FALLING WAS DEPENDENT ON SFC TEMPS AND WHETHER OR NOT
ANY ICE WAS IN THE CLOUD.
23.00Z ARE IN GOOD AGREEMENT WITH LIFTING THE TROUGH NORTHEAST
ACROSS THE REGION TODAY...AND OVER SOUTHEAST CANADA TONIGHT. THE
BULK OF THE ASSOCIATED QG CONVERGENCE WITH THE UPPER LEVEL FORCING
EXITS THE FORECAST AREA BY 18Z...AS DOES ANY ISENTROPIC UPGLIDE ON
THE 275-295 K SFCS. X-SECTIONS POINT TO SOME 2-D FRONTOGENETIC
FORCING...BUT THIS ALSO LIFTS TO THE NORTHEAST BY 18Z.
AS IT LOOKS NOW...THE BULK OF ANY ACCUMULATING PCPN SHOULD BE THIS
MORNING...WITH PERHAPS SOME LIGHT PCPN LINGERING INTO THE AFTERNOON
ACROSS NORTHERN AREAS. RUC13 BUFKIT SOUNDINGS SATURATE ENOUGH THAT
ICE IS INTRODUCED INTO THE CLOUD BY 3 AM...SO SNOW SHOULD BE THE
MAIN PCPN TYPE. MAIN MASS OF PCPN MOVING ACROSS THE REGION IS
ASSOCIATED WITH THE UPPER LEVEL TROUGH/QG CONVERGENCE. THE
DEFORMATION BAND NORTHWEST OF THE LOW HAS TWO AREAS...ONE FAIRLY
NARROW. THIS WAS IMPACTING WESTERN MN/WESTERN IA. THE MISH-MASH OF
DIFFERENT AREAS MAKES IT HARDER TO REFINE SNOW AMOUNTS FOR THIS
MORNING...BUT LOCATIONS TO THE WEST AND NORTH WILL HAVE SNOW FOR A
BIT LONGER...AND SLIGHTLY HIGHER AMOUNTS SHOULD BE FAVORED. OVERALL
1 TO 3 INCHES STILL LOOKS REASONABLE.
ON TOP OF THE SNOW THE STORM SYSTEM WILL BRING SOME BLUSTERY
CONDITIONS. TIGHTENING PRESSURE GRADIENT WILL RESULT IN NORTHWEST
WINDS OF 15 TO 25 MPH WITH GUSTS OF 30 TO 35 IN THE
OPEN/UNSHELTERED AREAS OF SOUTHEAST MN/NORTHEAST IA. THIS COULD
CAUSE SOME BLOWING OF THE FRESHLY FALLEN SNOW. THE PREVIOUS SNOW
COVER WILL BE HELD IN PLACE BY THE LIGHT GLAZING OF ICE FROM
YESTERDAY/S FREEZING DRIZZLE. LOW LEVEL COLD AIR ADVECTION WILL KEEP
TEMPERATURES STEADY...OR SLOWLY FALL. TODAY/S HIGH HAVE PROBABLY
ALREADY OCCURRED.
AS FOR THE WINTER WEATHER ADVISORY...WITH SNOW JUST MOVING IN...WILL
CONTINUE THE ADVISORY. THE NORTHERN PORTION OF THE ADVISORY MAY BE
ABLE TO BE CANCELLED BEFORE THE 6 PM EXPIRATION.
.LONG TERM...THURSDAY THROUGH SUNDAY
245 AM CST MON JAN 23 2012
MODELS POINT TO A MOSTLY ZONAL TO SOMEWHAT NORTHWEST UPPER LEVEL
FLOW THROUGH THE WEEKEND. BITS OF SHORTWAVE ENERGY WILL TRAVEL ALONG
THE FLOW...WITH DECENT AGREEMENT BETWEEN THE GFS AND EC WITH SLIDING
A TROUGH ACROSS THE UPPER MISSISSIPPI RIVER VALLEY WED NIGHT/THU.
THE BRUNT OF THE QPF STAYS NORTH OF THE FORECAST AREA
HOWEVER...ALTHOUGH A TIGHTENING PRESSURE GRADIENT WILL RESULT IN
SOME BLUSTERY CONDITIONS. OVERALL...THE PERIOD IS STILL TRENDING DRY
WITH TEMPS AT OR ABOVE THE SEASONABLE NORMALS.
&&
.AVIATION...THIS AFTERNOON THRU TUESDAY
1127 AM CST MON JAN 23 2012
LIGHT SNOW WILL DIMINISH AT THE TAFS SITES EARLY THIS AFTERNOON...
WITH CIGS/VSBYS LIFTING INTO THE MVFR RANGE AND VSBYS IMPROVING INTO
THE MVFR/VFR RANGE. BRISK NORTHWEST WINDS IN THE WAKE OF THE
DEPARTING LOW WILL CREATE SOME DRIFTING/BLOWING SNOW THRU THE
AFTERNOON HOURS AT SITES LIKE KRST. BIT LOWER STRATUS DECK OVER THE
EASTERN DAKOTAS/WESTERN MN WILL ROTATE ACROSS THE TAF SITES WITH
CIGS IN THE MVFR/IFR RANGE BY LATE EVENING AND OVERNIGHT AIDED BY
NOCTURNAL COOLING. WINDS WILL DIMINISH LATE THIS AFTERNOON AND THIS
EVENING AS THE LOW CONTINUES TO PULL AWAY AND THE SFC RIDGE AXIS
OVER THE DAKOTAS MOVES EAST. BIGGEST DILEMMA IS HOW QUICKLY WILL THE
LOWER CLOUDS/MVFR/IFR CIGS SCATTER/CLEAR OUT VERY LATE TONIGHT/TUE
MORNING. MODEL 925-850MB RH FIELDS WOULD HAVE THE CLOUDS OUT OF KRST
AROUND 10-11Z AND KLSE AROUND 15Z. GIVEN THE TIME OF YEAR AND
POSTION OF THE SFC-925MB RIDGE AXIS...THIS SEEMS A BIT OPTIMISTIC.
WENT WITH A SCT DECK AT 12Z KRST AND 16Z AT KLSE FOR NOW BUT AGAIN
THIS MAY BE ON THE OPTIMISTIC. LATER SHIFTS/CYCLES WILL BE ABLE TO
GET A BETTER ESTIMATE ON THE EASTWARD PROGRESS OF THE BACK EDGE OF
THE LOW CLOUDS IN THE DAKOTAS LATE THIS AFTERNOON/EVENING AS THE SFC
LOW CONTINUES TO LIFT INTO EASTERN ONTARIO.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
1218 PM CST MON JAN 23 2012
WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST FOR WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1129 AM CST MON JAN 23 2012
.AVIATION/18Z TAFS/...991 MILLIBAR SURFACE LOW IN NORTHERN LAKE
MICHIGAN CONTINUES TO PULL AWAY. WNW WINDS INCREASING WITH COLD
AIR ADVECTION. STILL SOME LINGERING LIGHT PRECIP...RAIN MIXING
WITH AND CHANGING TO LIGHT SNOW. IFR CEILINGS GRADUALLY TO GIVE
WAY TO MVFR CEILINGS. SHIELD OF LOW LELVEL CLOUDINESS EXTENDS FOR
TO THE WEST SO WILL BE A SLOW CLEARING TREND. PREFERRED THE MET
MOS TRENDS MORE SO THAN THE GFS IN THIS REGARD. ALSO LOW LEVEL RH
PROGS SUGGEST KEEPING A GOOD DEAL OF LOW CLOUDINESS INTO TUESDAY
MORNING. SURFACE HIGH BUILDS IN DURING THE AFTERNOON AND UPPER
FLOW BECOMES MORE ANTICYCLONIC...SO CONFIDENCE IN CLEARING
INCREASES HEADING TOWARDS THE AFTERNOON HOURS ON TUESDAY.
PC
&&
.PREV DISCUSSION... /ISSUED 242 AM CST MON JAN 23 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
NEGATIVE TILTED MID LEVEL/UPPER LEVEL TROUGH WILL MOVE ACROSS
WISCONSIN THIS MORNING BECOMING MORE OF A CLOSED LOW BY NOON...THEN
NORTH TOWARDS LAKE SUPERIOR THIS EVENING.
SURFACE LOW IS RATHER BROAD BUT THE CENTER SHOULD MOVE ACROSS
SOUTHEAST WISCONSIN THIS MORNING AND TO CENTRAL LAKE MICHIGAN BY
NOON...THEN NEAR LAKE HURON THIS EVENING. HIGHEST QPF OFF TO THE
SOUTHEAST AND EAST WITH SOME ELEVATED CAPE EARLY THIS MORNING
THICKNESS/BOUNDARY LAYER TEMPERATURES INDICATING MOST OF THE
PRECIPITATION LIQUID EXCEPT FOR A CHANGEOVER TO SNOW AROUND 6 AM
POSSIBLE WELL WEST OF MADISON. RUC SOUNDINGS PREFERRED OVER THE
COLDER NAM. THIS WOULD KEEP LIQUID AT MADISON UNTIL MID MORNING AND
OVER MILWAUKEE TOWARDS NOON.
MAIN CONCERN IS STILL WITH FREEZING RAIN POTENTIAL. SURFACE
TEMPERATURES ARE ALL ABOVE FREEZING EXCEPT IN AREAS TOWARDS THE
DELLS AND MARQUETTE COUNTY. OTHER PROBLEM IS WITH COLD ROAD
TEMPERATURES AND THE RAIN WASHING OFF THE RESIDUAL SALT...STILL SOME
SLIPPERY ROADS IN AREAS WITH TEMPERATURES IN THE MID 30S.
SOME DENSE FOG POTENTIAL EARLY THIS MORNING UNDER THE SURFACE LOW.
LIGHT ACCUMULATIONS OF SNOW EXPECTED WITH THE CHANGEOVER...UP TO AN
INCH. THIS MAINLY AS UPPER LOW MOVES ACROSS. TIGHT GRADIENT AROUND
THE LOW MAY GENERATE SOME PRETTY GUSTY WINDS...POTENTIALLY INTO THE
30-35 MPH RANGE LATER THIS AFTERNOON.
TUESDAY THROUGH SUNDAY...FORECAST CONFIDENCE...MEDIUM
FAIRLY QUIET WEATHER EXPECTED THROUGH THE REMAINDER OF THE WORK WEEK
AND INTO THE WEEKEND.
HIGH PRESSURE ON TUESDAY WILL BRING DECREASING CLOUDS WITH NEAR
NORMAL HIGH TEMPERATURES.
A PAIR OF WEAK WAVES TO ZIP THROUGH ZONAL FLOW WEDNESDAY AND
THURSDAY. NOT SEEING ENOUGH MOISTURE AND LIFT TO INCLUDE MENTION OF
POPS...THOUGH ONE OF THESE WAVES MAY SQUEEZE OUT A FEW FLURRIES.
ABOVE NORMAL TEMPS IN THE LOW TO MID 30S EXPECTED UNDER THE ZONAL
FLOW FOR MID WEEK.
ONE MORE DAY OF ABOVE NORMAL TEMPS FRIDAY WILL BE FOLLOWED BY
COLDER...BUT STILL NEAR NORMAL TEMPS FOR THE WEEKEND AS AN UPPER
TROUGH MOVES INTO THE GREAT LAKES. NOTHING IN THE MODELS AT THIS
TIME TO INCLUDE POPS FOR THE WEEKEND.
AVIATION/12Z TAFS/...WIDESPREAD LIFR CEILINGS/VSBYS WITH PLENTIFUL
LOW LEVEL MOISTURE AHEAD OF APPROACHING SURFACE LOW THAT SHOULD MOVE
ACROSS SOUTHEAST WISCONSIN THIS MORNING. ONCE LOW MOVES TO CENTRAL
LAKE MICHIGAN BY NOON...EXPECT COLD AIR ADVECTION TO GRADUALLY
CHANGE PRECIP OVER TO LIGHT SNOW. EXPECTING MINOR ACCUMULATIONS...AN
INCH OR LESS. WEST WINDS WILL BECOME RATHER GUSTY THIS AFTERNOON
WITH TIGHT GRADIENT AROUND STRONG DEPARTING LOW CENTER. CEILINGS
AND VSBYS WILL GRADUALLY RISE TO MVFR LATER THIS AFTERNOON AS THE
LOW PULLS AWAY. MVFR CIGS AND VFR VSBYS EXPECTED TONIGHT.
MARINE...A SMALL CRAFT ADVISORY IS IN EFFECT THROUGH MIDDAY TUESDAY
AS STRONG LOW PRESSURE REACHES CENTRAL LAKE MICHIGAN BY NOON. WINDS
WILL DIMINISH FOR A TIME UNDER THE LOW CENTER...BUT WILL INCREASE
AGAIN BEHIND A COLD FRONT EARLY THIS AFTERNOON AS WINDS BECOME
SOUTHWEST AND EVENTUALLY NORTHWEST. A FEW GALE GUSTS POSSIBLE....
ESPECIALLY LATE THIS AFTERNOON INTO THIS EVENING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL NOON CST TUESDAY FOR LMZ643>646.
DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR LMZ643-644.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
TUESDAY THROUGH SUNDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1127 AM CST MON JAN 23 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
245 AM CST MON JAN 23 2012
FORECAST CONCERNS FOCUS ON THE SNOW THIS MORNING.
LATEST WATERVAPOR IMAGERY DEPICTED AN UPPER LEVEL SHORTWAVE TROUGH
CHURNING ACROSS THE SOUTHERN PLAINS...WHILE AT THE SFC A LOW WAS
LOCATED OVER NORTHERN MO. 88-D RADAR IMAGERY SHOWED AREAS OF PCPN
SPREADING FROM THE DAKOTAS ACROSS MN/IA...AND ACROSS SOUTHERN WI AND
ILL. WHAT WAS FALLING WAS DEPENDENT ON SFC TEMPS AND WHETHER OR NOT
ANY ICE WAS IN THE CLOUD.
23.00Z ARE IN GOOD AGREEMENT WITH LIFTING THE TROUGH NORTHEAST
ACROSS THE REGION TODAY...AND OVER SOUTHEAST CANADA TONIGHT. THE
BULK OF THE ASSOCIATED QG CONVERGENCE WITH THE UPPER LEVEL FORCING
EXITS THE FORECAST AREA BY 18Z...AS DOES ANY ISENTROPIC UPGLIDE ON
THE 275-295 K SFCS. X-SECTIONS POINT TO SOME 2-D FRONTOGENETIC
FORCING...BUT THIS ALSO LIFTS TO THE NORTHEAST BY 18Z.
AS IT LOOKS NOW...THE BULK OF ANY ACCUMULATING PCPN SHOULD BE THIS
MORNING...WITH PERHAPS SOME LIGHT PCPN LINGERING INTO THE AFTERNOON
ACROSS NORTHERN AREAS. RUC13 BUFKIT SOUNDINGS SATURATE ENOUGH THAT
ICE IS INTRODUCED INTO THE CLOUD BY 3 AM...SO SNOW SHOULD BE THE
MAIN PCPN TYPE. MAIN MASS OF PCPN MOVING ACROSS THE REGION IS
ASSOCIATED WITH THE UPPER LEVEL TROUGH/QG CONVERGENCE. THE
DEFORMATION BAND NORTHWEST OF THE LOW HAS TWO AREAS...ONE FAIRLY
NARROW. THIS WAS IMPACTING WESTERN MN/WESTERN IA. THE MISH-MASH OF
DIFFERENT AREAS MAKES IT HARDER TO REFINE SNOW AMOUNTS FOR THIS
MORNING...BUT LOCATIONS TO THE WEST AND NORTH WILL HAVE SNOW FOR A
BIT LONGER...AND SLIGHTLY HIGHER AMOUNTS SHOULD BE FAVORED. OVERALL
1 TO 3 INCHES STILL LOOKS REASONABLE.
ON TOP OF THE SNOW THE STORM SYSTEM WILL BRING SOME BLUSTERY
CONDITIONS. TIGHTENING PRESSURE GRADIENT WILL RESULT IN NORTHWEST
WINDS OF 15 TO 25 MPH WITH GUSTS OF 30 TO 35 IN THE
OPEN/UNSHELTERED AREAS OF SOUTHEAST MN/NORTHEAST IA. THIS COULD
CAUSE SOME BLOWING OF THE FRESHLY FALLEN SNOW. THE PREVIOUS SNOW
COVER WILL BE HELD IN PLACE BY THE LIGHT GLAZING OF ICE FROM
YESTERDAY/S FREEZING DRIZZLE. LOW LEVEL COLD AIR ADVECTION WILL KEEP
TEMPERATURES STEADY...OR SLOWLY FALL. TODAY/S HIGH HAVE PROBABLY
ALREADY OCCURRED.
AS FOR THE WINTER WEATHER ADVISORY...WITH SNOW JUST MOVING IN...WILL
CONTINUE THE ADVISORY. THE NORTHERN PORTION OF THE ADVISORY MAY BE
ABLE TO BE CANCELLED BEFORE THE 6 PM EXPIRATION.
.LONG TERM...THURSDAY THROUGH SUNDAY
245 AM CST MON JAN 23 2012
MODELS POINT TO A MOSTLY ZONAL TO SOMEWHAT NORTHWEST UPPER LEVEL
FLOW THROUGH THE WEEKEND. BITS OF SHORTWAVE ENERGY WILL TRAVEL ALONG
THE FLOW...WITH DECENT AGREEMENT BETWEEN THE GFS AND EC WITH SLIDING
A TROUGH ACROSS THE UPPER MISSISSIPPI RIVER VALLEY WED NIGHT/THU.
THE BRUNT OF THE QPF STAYS NORTH OF THE FORECAST AREA
HOWEVER...ALTHOUGH A TIGHTENING PRESSURE GRADIENT WILL RESULT IN
SOME BLUSTERY CONDITIONS. OVERALL...THE PERIOD IS STILL TRENDING DRY
WITH TEMPS AT OR ABOVE THE SEASONABLE NORMALS.
&&
.AVIATION...THIS AFTERNOON THRU TUESDAY
1127 AM CST MON JAN 23 2012
LIGHT SNOW WILL DIMINISH AT THE TAFS SITES EARLY THIS AFTERNOON...
WITH CIGS/VSBYS LIFTING INTO THE MVFR RANGE AND VSBYS IMPROVING INTO
THE MVFR/VFR RANGE. BRISK NORTHWEST WINDS IN THE WAKE OF THE
DEPARTING LOW WILL CREATE SOME DRIFTING/BLOWING SNOW THRU THE
AFTERNOON HOURS AT SITES LIKE KRST. BIT LOWER STRATUS DECK OVER THE
EASTERN DAKOTAS/WESTERN MN WILL ROTATE ACROSS THE TAF SITES WITH
CIGS IN THE MVFR/IFR RANGE BY LATE EVENING AND OVERNIGHT AIDED BY
NOCTURNAL COOLING. WINDS WILL DIMINISH LATE THIS AFTERNOON AND THIS
EVENING AS THE LOW CONTINUES TO PULL AWAY AND THE SFC RIDGE AXIS
OVER THE DAKOTAS MOVES EAST. BIGGEST DILEMMA IS HOW QUICKLY WILL THE
LOWER CLOUDS/MVFR/IFR CIGS SCATTER/CLEAR OUT VERY LATE TONIGHT/TUE
MORNING. MODEL 925-850MB RH FIELDS WOULD HAVE THE CLOUDS OUT OF KRST
AROUND 10-11Z AND KLSE AROUND 15Z. GIVEN THE TIME OF YEAR AND
POSTION OF THE SFC-925MB RIDGE AXIS...THIS SEEMS A BIT OPTIMISTIC.
WENT WITH A SCT DECK AT 12Z KRST AND 16Z AT KLSE FOR NOW BUT AGAIN
THIS MAY BE ON THE OPTIMISTIC. LATER SHIFTS/CYCLES WILL BE ABLE TO
GET A BETTER ESTIMATE ON THE EASTWARD PROGRESS OF THE BACK EDGE OF
THE LOW CLOUDS IN THE DAKOTAS LATE THIS AFTERNOON/EVENING AS THE SFC
LOW CONTINUES TO LIFT INTO EASTERN ONTARIO.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
245 PM CST MON JAN 23 2012
WI...WINTER WEATHER ADVISORY UNTIL NOON CST FOR WIZ032>034-
041>044-053>055-061.
WINTER WEATHER ADVISORY UNTIL 6 PM CST FOR WIZ017-029.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST FOR MNZ079-086>088-
094>096.
IA...WINTER WEATHER ADVISORY UNTIL NOON CST FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1121 AM CST MON JAN 23 2012
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.UPDATE...BAND OF HEAVY SNOW SHIFTG THROUGH N-C WI NOW. IT APPEARS
2-3 INCHES HAS ALREADY FALLEN FM AUW NWD. LOOKS LIKE AREAS FROM
AUW NWD ARE HEADED TOWARD THE UPPER LIMITS OF THE SNOWFALL RANGES
WE HAVE IN GOING FCST. DON/T WANT TO OVERREACT THOUGH SINCE RADAR
SUGGESTS BEST SNOWS MOVG THROUGH NOW. NAM AND RUC BOTH SHOW VV/S
WEAKENING SUBSTANTIALLY BY MID-MORNING...WITH MODEST VALUES AT
BEST LINGERING NR THE UPPER MICHIGAN BORDER. THAT FITS WITH
COLDEST CLOUD TOPS LIFT THROUGH THAT AREA ON IR STLT NOW.
MAY NUDGE SNOWFALL TOTAL UP A BIT IN THE N. FARTHER S...IT/S
PROBABLY JUST A MATTER THAT WE/VE ALREADY RECEIVED MOST OF THE
SNOW WE ARE GOING TO GET. BEST OPTION THERE MAY BE TO REWORK FCST
TO CALL FOR LIMITED ADDITIONAL ACCUMULATIONS. PLAN TO SEND UPDATED
PRODUCT SUITE WITHIN ABOUT THE NEXT HALF HOUR.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 333 AM CST MON JAN 23 2012...
SYNOPSIS...WINTER WX ADVISORY WL REMAIN INTACT WITH THIS
ISSUANCE. MIXED PRECIPITATION CHANGING TO SNOW AND THEN ENDING
FROM SOUTHWEST TO NORTHEAST TODAY.
SPLIT FLOW WL DOMINATE THE CONUS FOR MUCH OF THE WEEK. BY NEXT
WEEKEND...RISING HEIGHTS OUT NR THE WEST COAST WL CAUSE THE
DOWNSTREAM FLOW TO CONSOLIDATE AGAIN...WITH BROAD TROF FORMING
OVER CEN/ERN NOAM.
MOST SIG PCPN EVENT WL BE WITH CYCLONE CROSSING THE RGN TDA...THEN
A PERIOD OF RELATIVELY QUIET WX EXPECTED AS THE FCST AREA IS
DOMINATED BY LOW-AMPLITUDE NRN STREAM THE REST OF THE WEEK. TEMPS
WL REMAIN ABV NORMAL MOST OF THE WK...THEN DROP BACK CLOSE TO
NORMAL AS BROAD UPR TROF DEVELOPS OVER THE FCST AREA NEXT WEEKEND.
SHORT TERM...TDA/TNGT/TUE. CYCLONE WL LIFT NEWD ACRS THE FCST
AREA THIS MORNING. DEEPENING MOISTURE...MID-LVL COOLING DUE TO
ASCENT...AND EVENTUALLY COLDER AIR WRAPPING ARND THE CYCLONE WL
RESULT IN DZ/FZDZ/RN CHANGING TO SN FM W TO E DURING THE DAY. THIS
WAS STARTING TO HAPPEN QUICKLY OVER WRN PARTS OF WI THIS MORNING.
SOUNDINGS CONSTRUCTED OFF RUC ANALYSES SUGGEST MUCH OF CENTRAL AND
N-C WL GO OVER TO SNOW ONCE BAND OF HEAVIER PCPN ARRIVES FROM THE
S. N-C WI AND PORTIONS OF NE WI WL NEED ADVISORY ALL DAY DUE TO
THE SNOW. NOT SURE SNOWFALLS WL JUSTIFY KEEPING ADVISORY GOING ALL
DAY OVER CENTRAL WI. BUT SNOW FALLING ON ICY ROADS WON/T BE
GOOD...SO TRAVEL CONDITIONS MAY REMAIN POOR. PLAN TO KEEP HEADLINE
INTACT WITH THE ISSUANCE AND JUST CANCEL EARLY IF/WHEN CONDITIONS
IMPROVE.
DENSE FOG COULD BE AN ISSUE IN THE E...ESP ALONG THE TRACKLINE OF
THE SFC LOW WHERE WINDS WL GO LGT FOR A TIME AS THE LOW CROSSES
THE AREA. BUT BAND OF HEAVIER PCPN THAT DEVELOPED DURING THE PAST
1-2 HRS WL WORK ACRS THIS AREA...HELPING TO MIX THE LOWER ATM.
SFC WINDS WERE ALSO LOSING THE SELY TRAJECTORY THAT WAS FEEDING
HIGHER DWPTS INTO THE AREA. BEST COURSE OF ACTION SEEM TO BE TO
GO WITH AREAS OF DENSE FOG IN THE GRIDS/ZONES...BUT FOREGO
ADVISORY SINCE IT DOESN/T APPEAR LOW VSBYS WL BE WIDESPREAD ENOUGH
TO WARRANT AN ADVISORY.
TRAJECTORIES LOOK FAVORABLE FOR SOME LAKE-EFFECT IN NORTH-CENTRAL
WI THIS AFTN INTO EARLY EVENING. LAKE SURFACE/AIR TEMPERATURE
DIFFERENCE SOMEWHAT MARGINAL...BUT PLENTY OF MOISTURE LINGERING FM
DEPARTING SYSTEM MAY OFFSET THAT. OTHER THAN THE LAKE-EFFECT...
PCPN SHOULD DIMINISH MOST AREAS BY EARLY EVENING.
CLDS LIKELY TO LINGER TNGT...WITH THE BEST CHC FOR BREAKS IN THE
TYPICAL NW-FLOW DOWNSLOPE AREA OVER THE NE.
HIGH TEMPS WL OCCUR EARLY TDA...FOLLOWED BY SLOWLY FALLING TEMPS.
BUT THE AIR BEHIND THE SYSTEM ISN/T REAL COLD...SO LINGERING
MOISTURE ON ROADWAYS SHOULD HAVE A CHC TO EVAPORATE BEFORE CAN
FREEZE. EDGED MINS UP A BIT TNGT...THEN WENT WITH BLEND OF BEST
PERFORMING GUID FOR MAXES TUE.
LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY.
THE UPPER FLOW WILL BE TRANSITIONING OVER THE PERIOD FROM A FAST
ZONAL PATTERN...TO BUCKLED NORTHWEST FLOW. AS A RESULT...MILD
PACIFIC DOMINATED AIRMASSES THROUGH THE END OF THIS WEEK WILL RETURN
TO THE POLAR VARIETY. A COUPLE OF MINOR SYSTEMS TO DEAL WITH
THROUGH THE EXTENDED. SIMILAR TO LAST NIGHT PREFER THE GFS FOR THE
SHORTWAVE LATE WEDNESDAY NIGHT INTO THURSDAY WITH THE FAST FLOW IN
PLACE. THEREAFTER...A CLIPPER SYSTEM WILL ARRIVE ON SATURDAY WHICH
WILL BE THE LEADING EDGE OF ARCTIC AIR. BOTH THE GFS AND ECMWF
HANDLE THIS FEATURE COMPARABLY...SO WILL BLEND THE TWO SOLUTIONS.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...WEAK SHEARED SHORTWAVE
WILL BE CROSSING THE REGION LATE TUESDAY NIGHT INTO EARLY WEDNESDAY
MORNING. MID AND HIGH CLOUDS WILL BE ON THE INCREASE TUESDAY NIGHT
AHEAD OF THE WAVE...BUT LOW LEVELS STRUGGLE TO SATURATE. SUPPOSE
THERE COULD BE A FLURRY OR TWO OUT OF THE MID-DECK BUT THATS MORE OF
A SHORT TERM CONCERN SO WILL LEAVE THE FORECAST DRY. SKIES WILL BE
CLEARING ON WEDNESDAY AS THE FIRST SHORTWAVE DEPARTS. HIGHS WILL BE
MILD WITHIN A PACIFIC AIRMASS WITH READINGS AROUND THE FREEZING
MARK. CLOUDS WILL BE ON THE INCREASE AGAIN WEDNESDAY NIGHT AHEAD OF
A MORE DYNAMIC SHORTWAVE. NOT SEEING THE GOOD MID-LEVEL LAPSE RATES
LIKE LAST NIGHT...BUT MID AND UPPER FORCING IS DECENT. STILL
LOOKING AT DRY WEDGES HOWEVER IN THE LOW AND MID-LEVELS WITH
MOISTURE PROFILES FAILING TO SATURATE. WILL AGAIN TREAT THIS AS A
SHORT TERM CONCERN AND REMOVE POPS.
REST OF THE FORECAST...THE SHORTWAVE TROUGH WILL FINISH CROSSING THE
REGION THURSDAY MORNING AND WILL AGAIN REMOVE THE SLIGHT CHANCE OF
PRECIP. SHOULD SEE SOME SUN MOVE IN FOR THE AFTERNOON WITH TEMPS
SLIGHTLY ABOVE FREEZING. NORTHWEST FLOW ALOFT WILL BE STRENGTHENING
THURSDAY NIGHT INTO FRIDAY...WHEN WILL HAVE WEAK COLD ADVECTION AND
BREEZY CONDITIONS OVER THE PERIOD...BUT NO PRECIP THREAT OF
SIGNIFICANCE. RATHER STRONG SHORTWAVE WILL BE MOVING ACROSS THE
REGION FRIDAY NIGHT...WHICH WILL BE THE LEADING EDGE OF AN ARCTIC
AIRMASS. TEMPERATURES WILL FALL BACK TO OR BELOW NORMAL WHILE WINDS
WILL BE PRETTY BRISK. CAN ENVISION OCCASIONAL SNOW FLURRIES OR
LIGHT SNOW SHOWERS FRIDAY NIGHT INTO SATURDAY AS THE UPPER TROUGH
SWINGS OVERHEAD. CURRENT FORECAST IS DRY...BUT WILL JUST MENTION TO
LATER SHIFTS. COLD AND DRY CONDITIONS ON SUNDAY...AND POSSIBLY SOME
LIGHT SNOW ON MONDAY AS ANOTHER CLIPPER SYSTEM MOVES THROUGH THE
REGION.
&&
.AVIATION...WIDESPREAD IFR/MVFR CONDITIONS TO CONTINUE ACROSS NE
WI THIS AFTERNOON AS THE STORM RESPONSIBLE FOR THE FREEZING DRZL
LAST NGT AND SNOW THIS MORNING BEGINS TO PULL NE INTO CANADA. THE
HEAVIEST SNOWS HAVE PULLED AWAY...BUT EXPECT LGT SNOW OR FLURRIES
TO LINGER INTO THE EVENING HOURS. LOW-LVL MSTR TO BE SLOW TO EXIT
THE RGN...THUS A GENERAL MVFR CIG CONDITION TO CONT OVRNGT. W-NW
WINDS COULD CREATE DOWNSLOPING AND PERHAPS BREAK SOME OF THESE
CLOUDS UP OVER THE GRB AND ATW TAF SITES LATER TNGT. A RDG OF HI
PRES BUILDING INTO WI ON MONDAY SHOULD PROVIDE ENUF DRY AIR TO
BREAK UP THE CLOUDS TOWARD THE MIDDAY HOUR WITH VFR CONDITIONS
RETURNING FOR MON AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ005-
010>013-018>021-030-031-035>037-045.
&&
$$
AK
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
637 AM CST MON JAN 23 2012
.UPDATE...BAND OF HEAVY SNOW SHIFTG THROUGH N-C WI NOW. IT APPEARS
2-3 INCHES HAS ALREADY FALLEN FM AUW NWD. LOOKS LIKE AREAS FROM
AUW NWD ARE HEADED TOWARD THE UPPER LIMITS OF THE SNOWFALL RANGES
WE HAVE IN GOING FCST. DON/T WANT TO OVERREACT THOUGH SINCE RADAR
SUGGESTS BEST SNOWS MOVG THROUGH NOW. NAM AND RUC BOTH SHOW VV/S
WEAKENING SUBSTANTIALLY BY MID-MORNING...WITH MODEST VALUES AT
BEST LINGERING NR THE UPPER MICHIGAN BORDER. THAT FITS WITH
COLDEST CLOUD TOPS LIFT THROUGH THAT AREA ON IR STLT NOW.
MAY NUDGE SNOWFALL TOTAL UP A BIT IN THE N. FARTHER S...IT/S
PROBABLY JUST A MATTER THAT WE/VE ALREADY RECEIVED MOST OF THE
SNOW WE ARE GOING TO GET. BEST OPTION THERE MAY BE TO REWORK FCST
TO CALL FOR LIMITED ADDITIONAL ACCUMULATIONS. PLAN TO SEND UPDATED
PRODUCT SUITE WITHIN ABOUT THE NEXT HALF HOUR.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 333 AM CST MON JAN 23 2012...
SYNOPSIS...WINTER WX ADVISORY WL REMAIN INTACT WITH THIS
ISSUANCE. MIXED PRECIPITATION CHANGING TO SNOW AND THEN ENDING
FROM SOUTHWEST TO NORTHEAST TODAY.
SPLIT FLOW WL DOMINATE THE CONUS FOR MUCH OF THE WEEK. BY NEXT
WEEKEND...RISING HEIGHTS OUT NR THE WEST COAST WL CAUSE THE
DOWNSTREAM FLOW TO CONSOLIDATE AGAIN...WITH BROAD TROF FORMING
OVER CEN/ERN NOAM.
MOST SIG PCPN EVENT WL BE WITH CYCLONE CROSSING THE RGN TDA...THEN
A PERIOD OF RELATIVELY QUIET WX EXPECTED AS THE FCST AREA IS
DOMINATED BY LOW-AMPLITUDE NRN STREAM THE REST OF THE WEEK. TEMPS
WL REMAIN ABV NORMAL MOST OF THE WK...THEN DROP BACK CLOSE TO
NORMAL AS BROAD UPR TROF DEVELOPS OVER THE FCST AREA NEXT WEEKEND.
SHORT TERM...TDA/TNGT/TUE. CYCLONE WL LIFT NEWD ACRS THE FCST
AREA THIS MORNING. DEEPENING MOISTURE...MID-LVL COOLING DUE TO
ASCENT...AND EVENTUALLY COLDER AIR WRAPPING ARND THE CYCLONE WL
RESULT IN DZ/FZDZ/RN CHANGING TO SN FM W TO E DURING THE DAY. THIS
WAS STARTING TO HAPPEN QUICKLY OVER WRN PARTS OF WI THIS MORNING.
SOUNDINGS CONSTRUCTED OFF RUC ANALYSES SUGGEST MUCH OF CENTRAL AND
N-C WL GO OVER TO SNOW ONCE BAND OF HEAVIER PCPN ARRIVES FROM THE
S. N-C WI AND PORTIONS OF NE WI WL NEED ADVISORY ALL DAY DUE TO
THE SNOW. NOT SURE SNOWFALLS WL JUSTIFY KEEPING ADVISORY GOING ALL
DAY OVER CENTRAL WI. BUT SNOW FALLING ON ICY ROADS WON/T BE
GOOD...SO TRAVEL CONDITIONS MAY REMAIN POOR. PLAN TO KEEP HEADLINE
INTACT WITH THE ISSUANCE AND JUST CANCEL EARLY IF/WHEN CONDITIONS
IMPROVE.
DENSE FOG COULD BE AN ISSUE IN THE E...ESP ALONG THE TRACKLINE OF
THE SFC LOW WHERE WINDS WL GO LGT FOR A TIME AS THE LOW CROSSES
THE AREA. BUT BAND OF HEAVIER PCPN THAT DEVELOPED DURING THE PAST
1-2 HRS WL WORK ACRS THIS AREA...HELPING TO MIX THE LOWER ATM.
SFC WINDS WERE ALSO LOSING THE SELY TRAJECTORY THAT WAS FEEDING
HIGHER DWPTS INTO THE AREA. BEST COURSE OF ACTION SEEM TO BE TO
GO WITH AREAS OF DENSE FOG IN THE GRIDS/ZONES...BUT FOREGO
ADVISORY SINCE IT DOESN/T APPEAR LOW VSBYS WL BE WIDESPREAD ENOUGH
TO WARRANT AN ADVISORY.
TRAJECTORIES LOOK FAVORABLE FOR SOME LAKE-EFFECT IN NORTH-CENTRAL
WI THIS AFTN INTO EARLY EVENING. LAKE SURFACE/AIR TEMPERATURE
DIFFERENCE SOMEWHAT MARGINAL...BUT PLENTY OF MOISTURE LINGERING FM
DEPARTING SYSTEM MAY OFFSET THAT. OTHER THAN THE LAKE-EFFECT...
PCPN SHOULD DIMINISH MOST AREAS BY EARLY EVENING.
CLDS LIKELY TO LINGER TNGT...WITH THE BEST CHC FOR BREAKS IN THE
TYPICAL NW-FLOW DOWNSLOPE AREA OVER THE NE.
HIGH TEMPS WL OCCUR EARLY TDA...FOLLOWED BY SLOWLY FALLING TEMPS.
BUT THE AIR BEHIND THE SYSTEM ISN/T REAL COLD...SO LINGERING
MOISTURE ON ROADWAYS SHOULD HAVE A CHC TO EVAPORATE BEFORE CAN
FREEZE. EDGED MINS UP A BIT TNGT...THEN WENT WITH BLEND OF BEST
PERFORMING GUID FOR MAXES TUE.
LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY.
THE UPPER FLOW WILL BE TRANSITIONING OVER THE PERIOD FROM A FAST
ZONAL PATTERN...TO BUCKLED NORTHWEST FLOW. AS A RESULT...MILD
PACIFIC DOMINATED AIRMASSES THROUGH THE END OF THIS WEEK WILL RETURN
TO THE POLAR VARIETY. A COUPLE OF MINOR SYSTEMS TO DEAL WITH
THROUGH THE EXTENDED. SIMILAR TO LAST NIGHT PREFER THE GFS FOR THE
SHORTWAVE LATE WEDNESDAY NIGHT INTO THURSDAY WITH THE FAST FLOW IN
PLACE. THEREAFTER...A CLIPPER SYSTEM WILL ARRIVE ON SATURDAY WHICH
WILL BE THE LEADING EDGE OF ARCTIC AIR. BOTH THE GFS AND ECMWF
HANDLE THIS FEATURE COMPARABLY...SO WILL BLEND THE TWO SOLUTIONS.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...WEAK SHEARED SHORTWAVE
WILL BE CROSSING THE REGION LATE TUESDAY NIGHT INTO EARLY WEDNESDAY
MORNING. MID AND HIGH CLOUDS WILL BE ON THE INCREASE TUESDAY NIGHT
AHEAD OF THE WAVE...BUT LOW LEVELS STRUGGLE TO SATURATE. SUPPOSE
THERE COULD BE A FLURRY OR TWO OUT OF THE MID-DECK BUT THATS MORE OF
A SHORT TERM CONCERN SO WILL LEAVE THE FORECAST DRY. SKIES WILL BE
CLEARING ON WEDNESDAY AS THE FIRST SHORTWAVE DEPARTS. HIGHS WILL BE
MILD WITHIN A PACIFIC AIRMASS WITH READINGS AROUND THE FREEZING
MARK. CLOUDS WILL BE ON THE INCREASE AGAIN WEDNESDAY NIGHT AHEAD OF
A MORE DYNAMIC SHORTWAVE. NOT SEEING THE GOOD MID-LEVEL LAPSE RATES
LIKE LAST NIGHT...BUT MID AND UPPER FORCING IS DECENT. STILL
LOOKING AT DRY WEDGES HOWEVER IN THE LOW AND MID-LEVELS WITH
MOISTURE PROFILES FAILING TO SATURATE. WILL AGAIN TREAT THIS AS A
SHORT TERM CONCERN AND REMOVE POPS.
REST OF THE FORECAST...THE SHORTWAVE TROUGH WILL FINISH CROSSING THE
REGION THURSDAY MORNING AND WILL AGAIN REMOVE THE SLIGHT CHANCE OF
PRECIP. SHOULD SEE SOME SUN MOVE IN FOR THE AFTERNOON WITH TEMPS
SLIGHTLY ABOVE FREEZING. NORTHWEST FLOW ALOFT WILL BE STRENGTHENING
THURSDAY NIGHT INTO FRIDAY...WHEN WILL HAVE WEAK COLD ADVECTION AND
BREEZY CONDITIONS OVER THE PERIOD...BUT NO PRECIP THREAT OF
SIGNIFICANCE. RATHER STRONG SHORTWAVE WILL BE MOVING ACROSS THE
REGION FRIDAY NIGHT...WHICH WILL BE THE LEADING EDGE OF AN ARCTIC
AIRMASS. TEMPERATURES WILL FALL BACK TO OR BELOW NORMAL WHILE WINDS
WILL BE PRETTY BRISK. CAN ENVISION OCCASIONAL SNOW FLURRIES OR
LIGHT SNOW SHOWERS FRIDAY NIGHT INTO SATURDAY AS THE UPPER TROUGH
SWINGS OVERHEAD. CURRENT FORECAST IS DRY...BUT WILL JUST MENTION TO
LATER SHIFTS. COLD AND DRY CONDITIONS ON SUNDAY...AND POSSIBLY SOME
LIGHT SNOW ON MONDAY AS ANOTHER CLIPPER SYSTEM MOVES THROUGH THE
REGION.
&&
.AVIATION...FOR 12Z TAF ISSUANCE...LIFR/VLIFR CONDITIONS
WIDESPREAD ACRS THE AREA THIS MORNING. CONDITIONS SHOULD START TO
IMPROVE LATER TDA ONCE THE LOW PULLS OFF TO THE NE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ005-
010>013-018>021-030-031-035>037-045.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
535 AM CST MON JAN 23 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
245 AM CST MON JAN 23 2012
FORECAST CONCERNS FOCUS ON THE SNOW THIS MORNING.
LATEST WATERVAPOR IMAGERY DEPICTED AN UPPER LEVEL SHORTWAVE TROUGH
CHURNING ACROSS THE SOUTHERN PLAINS...WHILE AT THE SFC A LOW WAS
LOCATED OVER NORTHERN MO. 88-D RADAR IMAGERY SHOWED AREAS OF PCPN
SPREADING FROM THE DAKOTAS ACROSS MN/IA...AND ACROSS SOUTHERN WI AND
ILL. WHAT WAS FALLING WAS DEPENDENT ON SFC TEMPS AND WHETHER OR NOT
ANY ICE WAS IN THE CLOUD.
23.00Z ARE IN GOOD AGREEMENT WITH LIFTING THE TROUGH NORTHEAST
ACROSS THE REGION TODAY...AND OVER SOUTHEAST CANADA TONIGHT. THE
BULK OF THE ASSOCIATED QG CONVERGENCE WITH THE UPPER LEVEL FORCING
EXITS THE FORECAST AREA BY 18Z...AS DOES ANY ISENTROPIC UPGLIDE ON
THE 275-295 K SFCS. X-SECTIONS POINT TO SOME 2-D FRONTOGENETIC
FORCING...BUT THIS ALSO LIFTS TO THE NORTHEAST BY 18Z.
AS IT LOOKS NOW...THE BULK OF ANY ACCUMULATING PCPN SHOULD BE THIS
MORNING...WITH PERHAPS SOME LIGHT PCPN LINGERING INTO THE AFTERNOON
ACROSS NORTHERN AREAS. RUC13 BUFKIT SOUNDINGS SATURATE ENOUGH THAT
ICE IS INTRODUCED INTO THE CLOUD BY 3 AM...SO SNOW SHOULD BE THE
MAIN PCPN TYPE. MAIN MASS OF PCPN MOVING ACROSS THE REGION IS
ASSOCIATED WITH THE UPPER LEVEL TROUGH/QG CONVERGENCE. THE
DEFORMATION BAND NORTHWEST OF THE LOW HAS TWO AREAS...ONE FAIRLY
NARROW. THIS WAS IMPACTING WESTERN MN/WESTERN IA. THE MISH-MASH OF
DIFFERENT AREAS MAKES IT HARDER TO REFINE SNOW AMOUNTS FOR THIS
MORNING...BUT LOCATIONS TO THE WEST AND NORTH WILL HAVE SNOW FOR A
BIT LONGER...AND SLIGHTLY HIGHER AMOUNTS SHOULD BE FAVORED. OVERALL
1 TO 3 INCHES STILL LOOKS REASONABLE.
ON TOP OF THE SNOW THE STORM SYSTEM WILL BRING SOME BLUSTERY
CONDITIONS. TIGHTENING PRESSURE GRADIENT WILL RESULT IN NORTHWEST
WINDS OF 15 TO 25 MPH WITH GUSTS OF 30 TO 35 IN THE
OPEN/UNSHELTERED AREAS OF SOUTHEAST MN/NORTHEAST IA. THIS COULD
CAUSE SOME BLOWING OF THE FRESHLY FALLEN SNOW. THE PREVIOUS SNOW
COVER WILL BE HELD IN PLACE BY THE LIGHT GLAZING OF ICE FROM
YESTERDAY/S FREEZING DRIZZLE. LOW LEVEL COLD AIR ADVECTION WILL KEEP
TEMPERATURES STEADY...OR SLOWLY FALL. TODAY/S HIGH HAVE PROBABLY
ALREADY OCCURRED.
AS FOR THE WINTER WEATHER ADVISORY...WITH SNOW JUST MOVING IN...WILL
CONTINUE THE ADVISORY. THE NORTHERN PORTION OF THE ADVISORY MAY BE
ABLE TO BE CANCELLED BEFORE THE 6 PM EXPIRATION.
.LONG TERM...THURSDAY THROUGH SUNDAY
245 AM CST MON JAN 23 2012
MODELS POINT TO A MOSTLY ZONAL TO SOMEWHAT NORTHWEST UPPER LEVEL
FLOW THROUGH THE WEEKEND. BITS OF SHORTWAVE ENERGY WILL TRAVEL ALONG
THE FLOW...WITH DECENT AGREEMENT BETWEEN THE GFS AND EC WITH SLIDING
A TROUGH ACROSS THE UPPER MISSISSIPPI RIVER VALLEY WED NIGHT/THU.
THE BRUNT OF THE QPF STAYS NORTH OF THE FORECAST AREA
HOWEVER...ALTHOUGH A TIGHTENING PRESSURE GRADIENT WILL RESULT IN
SOME BLUSTERY CONDITIONS. OVERALL...THE PERIOD IS STILL TRENDING DRY
WITH TEMPS AT OR ABOVE THE SEASONABLE NORMALS.
&&
.AVIATION...TODAY AND TONIGHT
535 AM CST MON JAN 23 2012
LIGHT SNOW WILL CONTINUE TO FALL THROUGH THIS MORNING THEN COME TO
AN END AT KRST AND KLSE AROUND 18Z AS DEEP LOW PRESSURE LIFTS
NORTHWARD INTO UPPER MICHIGAN. TOTAL ACCUMULATIONS OF 2-3 INCHES
CAN BE EXPECTED AT KRST WITH 1-2 INCHES EXPECTED AT KLSE. SOME
BLOWING SNOW CAN ALSO BE EXPECTED AT KRST AS NORTHWEST WINDS GUST
UP TO 30 KT. LOOK FOR IFR CONDITIONS THIS MORNING IMPROVE INTO
MVFR CATEGORY BY 18Z. MVFR STRATUS EXPECTED TO LINGER THROUGH
TONIGHT WITH WINDS SLOWLY DIMINISHING AFTER SUNSET.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
245 PM CST MON JAN 23 2012
WI...WINTER WEATHER ADVISORY UNTIL NOON CST FOR WIZ032>034-
041>044-053>055-061.
WINTER WEATHER ADVISORY UNTIL 6 PM CST FOR WIZ017-029.
MN...WINTER WEATHER ADVISORY UNTIL NOON CST FOR MNZ079-086>088-
094>096.
IA...WINTER WEATHER ADVISORY UNTIL NOON CST FOR IAZ008>011-018-
019-029-030.
&&
$$
SHORT TERM... RIECK
LONG TERM.... RIECK
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
333 AM CST MON JAN 23 2012
.SYNOPSIS...WINTER WX ADVISORY WL REMAIN INTACT WITH THIS
ISSUANCE. MIXED PRECIPITATION CHANGING TO SNOW AND THEN ENDING
FROM SOUTHWEST TO NORTHEAST TODAY.
SPLIT FLOW WL DOMINATE THE CONUS FOR MUCH OF THE WEEK. BY NEXT
WEEKEND...RISING HEIGHTS OUT NR THE WEST COAST WL CAUSE THE
DOWNSTREAM FLOW TO CONSOLIDATE AGAIN...WITH BROAD TROF FORMING
OVER CEN/ERN NOAM.
MOST SIG PCPN EVENT WL BE WITH CYCLONE CROSSING THE RGN TDA...THEN
A PERIOD OF RELATIVELY QUIET WX EXPECTED AS THE FCST AREA IS
DOMINATED BY LOW-AMPLITUDE NRN STREAM THE REST OF THE WEEK. TEMPS
WL REMAIN ABV NORMAL MOST OF THE WK...THEN DROP BACK CLOSE TO
NORMAL AS BROAD UPR TROF DEVELOPS OVER THE FCST AREA NEXT WEEKEND.
&&
.SHORT TERM...TDA/TNGT/TUE. CYCLONE WL LIFT NEWD ACRS THE FCST
AREA THIS MORNING. DEEPENING MOISTURE...MID-LVL COOLING DUE TO
ASCENT...AND EVENTUALLY COLDER AIR WRAPPING ARND THE CYCLONE WL
RESULT IN DZ/FZDZ/RN CHANGING TO SN FM W TO E DURING THE DAY. THIS
WAS STARTING TO HAPPEN QUICKLY OVER WRN PARTS OF WI THIS MORNING.
SOUNDINGS CONSTRUCTED OFF RUC ANALYSES SUGGEST MUCH OF CENTRAL AND
N-C WL GO OVER TO SNOW ONCE BAND OF HEAVIER PCPN ARRIVES FROM THE
S. N-C WI AND PORTIONS OF NE WI WL NEED ADVISORY ALL DAY DUE TO
THE SNOW. NOT SURE SNOWFALLS WL JUSTIFY KEEPING ADVISORY GOING ALL
DAY OVER CENTRAL WI. BUT SNOW FALLING ON ICY ROADS WON/T BE
GOOD...SO TRAVEL CONDITIONS MAY REMAIN POOR. PLAN TO KEEP HEADLINE
INTACT WITH THE ISSUANCE AND JUST CANCEL EARLY IF/WHEN CONDITIONS
IMPROVE.
DENSE FOG COULD BE AN ISSUE IN THE E...ESP ALONG THE TRACKLINE OF
THE SFC LOW WHERE WINDS WL GO LGT FOR A TIME AS THE LOW CROSSES
THE AREA. BUT BAND OF HEAVIER PCPN THAT DEVELOPED DURING THE PAST
1-2 HRS WL WORK ACRS THIS AREA...HELPING TO MIX THE LOWER ATM.
SFC WINDS WERE ALSO LOSING THE SELY TRAJECTORY THAT WAS FEEDING
HIGHER DWPTS INTO THE AREA. BEST COURSE OF ACTION SEEM TO BE TO
GO WITH AREAS OF DENSE FOG IN THE GRIDS/ZONES...BUT FOREGO
ADVISORY SINCE IT DOESN/T APPEAR LOW VSBYS WL BE WIDESPREAD ENOUGH
TO WARRANT AN ADVISORY.
TRAJECTORIES LOOK FAVORABLE FOR SOME LAKE-EFFECT IN NORTH-CENTRAL
WI THIS AFTN INTO EARLY EVENING. LAKE SURFACE/AIR TEMPERATURE
DIFFERENCE SOMEWHAT MARGINAL...BUT PLENTY OF MOISTURE LINGERING FM
DEPARTING SYSTEM MAY OFFSET THAT. OTHER THAN THE LAKE-EFFECT...
PCPN SHOULD DIMINISH MOST AREAS BY EARLY EVENING.
CLDS LIKELY TO LINGER TNGT...WITH THE BEST CHC FOR BREAKS IN THE
TYPICAL NW-FLOW DOWNSLOPE AREA OVER THE NE.
HIGH TEMPS WL OCCUR EARLY TDA...FOLLOWED BY SLOWLY FALLING TEMPS.
BUT THE AIR BEHIND THE SYSTEM ISN/T REAL COLD...SO LINGERING
MOISTURE ON ROADWAYS SHOULD HAVE A CHC TO EVAPORATE BEFORE CAN
FREEZE. EDGED MINS UP A BIT TNGT...THEN WENT WITH BLEND OF BEST
PERFORMING GUID FOR MAXES TUE.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY.
THE UPPER FLOW WILL BE TRANSITIONING OVER THE PERIOD FROM A FAST
ZONAL PATTERN...TO BUCKLED NORTHWEST FLOW. AS A RESULT...MILD
PACIFIC DOMINATED AIRMASSES THROUGH THE END OF THIS WEEK WILL RETURN
TO THE POLAR VARIETY. A COUPLE OF MINOR SYSTEMS TO DEAL WITH
THROUGH THE EXTENDED. SIMILAR TO LAST NIGHT PREFER THE GFS FOR THE
SHORTWAVE LATE WEDNESDAY NIGHT INTO THURSDAY WITH THE FAST FLOW IN
PLACE. THEREAFTER...A CLIPPER SYSTEM WILL ARRIVE ON SATURDAY WHICH
WILL BE THE LEADING EDGE OF ARCTIC AIR. BOTH THE GFS AND ECMWF
HANDLE THIS FEATURE COMPARABLY...SO WILL BLEND THE TWO SOLUTIONS.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...WEAK SHEARED SHORTWAVE
WILL BE CROSSING THE REGION LATE TUESDAY NIGHT INTO EARLY WEDNESDAY
MORNING. MID AND HIGH CLOUDS WILL BE ON THE INCREASE TUESDAY NIGHT
AHEAD OF THE WAVE...BUT LOW LEVELS STRUGGLE TO SATURATE. SUPPOSE
THERE COULD BE A FLURRY OR TWO OUT OF THE MID-DECK BUT THATS MORE OF
A SHORT TERM CONCERN SO WILL LEAVE THE FORECAST DRY. SKIES WILL BE
CLEARING ON WEDNESDAY AS THE FIRST SHORTWAVE DEPARTS. HIGHS WILL BE
MILD WITHIN A PACIFIC AIRMASS WITH READINGS AROUND THE FREEZING
MARK. CLOUDS WILL BE ON THE INCREASE AGAIN WEDNESDAY NIGHT AHEAD OF
A MORE DYNAMIC SHORTWAVE. NOT SEEING THE GOOD MID-LEVEL LAPSE RATES
LIKE LAST NIGHT...BUT MID AND UPPER FORCING IS DECENT. STILL
LOOKING AT DRY WEDGES HOWEVER IN THE LOW AND MID-LEVELS WITH
MOISTURE PROFILES FAILING TO SATURATE. WILL AGAIN TREAT THIS AS A
SHORT TERM CONCERN AND REMOVE POPS.
REST OF THE FORECAST...THE SHORTWAVE TROUGH WILL FINISH CROSSING THE
REGION THURSDAY MORNING AND WILL AGAIN REMOVE THE SLIGHT CHANCE OF
PRECIP. SHOULD SEE SOME SUN MOVE IN FOR THE AFTERNOON WITH TEMPS
SLIGHTLY ABOVE FREEZING. NORTHWEST FLOW ALOFT WILL BE STRENGTHENING
THURSDAY NIGHT INTO FRIDAY...WHEN WILL HAVE WEAK COLD ADVECTION AND
BREEZY CONDITIONS OVER THE PERIOD...BUT NO PRECIP THREAT OF
SIGNIFICANCE. RATHER STRONG SHORTWAVE WILL BE MOVING ACROSS THE
REGION FRIDAY NIGHT...WHICH WILL BE THE LEADING EDGE OF AN ARCTIC
AIRMASS. TEMPERATURES WILL FALL BACK TO OR BELOW NORMAL WHILE WINDS
WILL BE PRETTY BRISK. CAN ENVISION OCCASIONAL SNOW FLURRIES OR
LIGHT SNOW SHOWERS FRIDAY NIGHT INTO SATURDAY AS THE UPPER TROUGH
SWINGS OVERHEAD. CURRENT FORECAST IS DRY...BUT WILL JUST MENTION TO
LATER SHIFTS. COLD AND DRY CONDITIONS ON SUNDAY...AND POSSIBLY SOME
LIGHT SNOW ON MONDAY AS ANOTHER CLIPPER SYSTEM MOVES THROUGH THE
REGION.
&&
.AVIATION...FOR 12Z TAF ISSUANCE...LIFR/VLIFR CONDITIONS
WIDESPREAD ACRS THE AREA THIS MORNING. CONDITIONS SHOULD START TO
IMPROVE LATER TDA ONCE THE LOW PULLS OFF TO THE NE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ005-
010>013-018>021-030-031-035>037-045.
&&
$$
SKOWRONSKI/MPC
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
242 AM CST MON JAN 23 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
NEGATIVE TILTED MID LEVEL/UPPER LEVEL TROUGH WILL MOVE ACROSS
WISCONSIN THIS MORNING BECOMING MORE OF A CLOSED LOW BY NOON...THEN
NORTH TOWARDS LAKE SUPERIOR THIS EVENING.
SURFACE LOW IS RATHER BROAD BUT THE CENTER SHOULD MOVE ACROSS
SOUTHEAST WISCONSIN THIS MORNING AND TO CENTRAL LAKE MICHIGAN BY
NOON...THEN NEAR LAKE HURON THIS EVENING. HIGHEST QPF OFF TO THE
SOUTHEAST AND EAST WITH SOME ELEVATED CAPE EARLY THIS MORNING
THICKNESS/BOUNDARY LAYER TEMPERATURES INDICATING MOST OF THE
PRECIPITATION LIQUID EXCEPT FOR A CHANGEOVER TO SNOW AROUND 6 AM
POSSIBLE WELL WEST OF MADISON. RUC SOUNDINGS PREFERRED OVER THE
COLDER NAM. THIS WOULD KEEP LIQUID AT MADISON UNTIL MID MORNING AND
OVER MILWAUKEE TOWARDS NOON.
MAIN CONCERN IS STILL WITH FREEZING RAIN POTENTIAL. SURFACE
TEMPERATURES ARE ALL ABOVE FREEZING EXCEPT IN AREAS TOWARDS THE
DELLS AND MARQUETTE COUNTY. OTHER PROBLEM IS WITH COLD ROAD
TEMPERATURES AND THE RAIN WASHING OFF THE RESIDUAL SALT...STILL SOME
SLIPPERY ROADS IN AREAS WITH TEMPERATURES IN THE MID 30S.
SOME DENSE FOG POTENTIAL EARLY THIS MORNING UNDER THE SURFACE LOW.
LIGHT ACCUMULATIONS OF SNOW EXPECTED WITH THE CHANGEOVER...UP TO AN
INCH. THIS MAINLY AS UPPER LOW MOVES ACROSS. TIGHT GRADIENT AROUND
THE LOW MAY GENERATE SOME PRETTY GUSTY WINDS...POTENTIALLY INTO THE
30-35 MPH RANGE LATER THIS AFTERNOON.
.TUESDAY THROUGH SUNDAY...FORECAST CONFIDENCE...MEDIUM
FAIRLY QUIET WEATHER EXPECTED THROUGH THE REMAINDER OF THE WORK WEEK
AND INTO THE WEEKEND.
HIGH PRESSURE ON TUESDAY WILL BRING DECREASING CLOUDS WITH NEAR
NORMAL HIGH TEMPERATURES.
A PAIR OF WEAK WAVES TO ZIP THROUGH ZONAL FLOW WEDNESDAY AND
THURSDAY. NOT SEEING ENOUGH MOISTURE AND LIFT TO INCLUDE MENTION OF
POPS...THOUGH ONE OF THESE WAVES MAY SQUEEZE OUT A FEW FLURRIES.
ABOVE NORMAL TEMPS IN THE LOW TO MID 30S EXPECTED UNDER THE ZONAL
FLOW FOR MID WEEK.
ONE MORE DAY OF ABOVE NORMAL TEMPS FRIDAY WILL BE FOLLOWED BY
COLDER...BUT STILL NEAR NORMAL TEMPS FOR THE WEEKEND AS AN UPPER
TROUGH MOVES INTO THE GREAT LAKES. NOTHING IN THE MODELS AT THIS
TIME TO INCLUDE POPS FOR THE WEEKEND.
&&
.AVIATION/12Z TAFS/...WIDESPREAD LIFR CEILINGS/VSBYS WITH PLENTIFUL
LOW LEVEL MOISTURE AHEAD OF APPROACHING SURFACE LOW THAT SHOULD MOVE
ACROSS SOUTHEAST WISCONSIN THIS MORNING. ONCE LOW MOVES TO CENTRAL
LAKE MICHIGAN BY NOON...EXPECT COLD AIR ADVECTION TO GRADUALLY
CHANGE PRECIP OVER TO LIGHT SNOW. EXPECTING MINOR ACCUMULATIONS...AN
INCH OR LESS. WEST WINDS WILL BECOME RATHER GUSTY THIS AFTERNOON
WITH TIGHT GRADIENT AROUND STRONG DEPARTING LOW CENTER. CEILINGS
AND VSBYS WILL GRADUALLY RISE TO MVFR LATER THIS AFTERNOON AS THE
LOW PULLS AWAY. MVFR CIGS AND VFR VSBYS EXPECTED TONIGHT.
&&
.MARINE...A SMALL CRAFT ADVISORY IS IN EFFECT THROUGH MIDDAY TUESDAY
AS STRONG LOW PRESSURE REACHES CENTRAL LAKE MICHIGAN BY NOON. WINDS
WILL DIMINISH FOR A TIME UNDER THE LOW CENTER...BUT WILL INCREASE
AGAIN BEHIND A COLD FRONT EARLY THIS AFTERNOON AS WINDS BECOME
SOUTHWEST AND EVENTUALLY NORTHWEST. A FEW GALE GUSTS POSSIBLE....
ESPECIALLY LATE THIS AFTERNOON INTO THIS EVENING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ051-052-
058>060-063>066-068>072.
DENSE FOG ADVISORY UNTIL 7 AM CST THIS MORNING FOR WIZ062-067.
WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ046-
047-056-057.
LM...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR LMZ643>646.
SMALL CRAFT ADVISORY UNTIL NOON CST TUESDAY FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
TUESDAY THROUGH SUNDAY...DDV
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
359 AM EST WED JAN 25 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA TODAY WILL MOVE OFF THE COAST TONIGHT.
A LOW PRESSURE SYSTEM WILL AFFECT THE AREA THURSDAY INTO FRIDAY.
DRY HIGH PRESSURE WILL TAKE CONTROL FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LINGERING LOW LEVEL MOISTURE HAS ALLOWED AREAS OF FOG TO DEVELOP
ACROSS THE MIDLANDS EARLY THIS MORNING. IT APPEARS THE LARGEST
AREA IS AFFECTING THE NORTH MIDLANDS. THE RUC AND NAM20 MODELS
INDICATE THE LOW LEVEL MOISTURE TO LINGER THROUGH THE 12Z-14Z
TIME-FRAME. HOWEVER..BOTH MODELS SHOW A LOW LEVEL JET WHICH PROMOTE
MIXING. SO...NOT WE ARE NOT EXPECTING THE FOG TO BE AS
WIDESPREAD AS TUESDAY MORNING. WILL CONTINUE THE DENSE FOG
ADVISORY FOR LANCASTER AND CHESTERFIELD COUNTIES THROUGH 7 AM...
AND ADD AREAS OF FOG TO OTHER SECTIONS OF THE MIDLANDS. THE FOG
HIGH PRESSURE CENTERED OVER THE OH RIVER VALLEY WILL MOVE EAST TO
THE MID ATLANTIC COAST THROUGH THE EVENING. WEAK UPPER LEVEL
RIDGING WILL ALSO BUILD ACROSS THE SOUTHEASTERN STATES. WE WILL
SEE PARTLY TO MOSTLY SUNNY SKIES TODAY WITH HIGHS IN THE MID 60S
NORTH TO AROUND 70 SOUTH. MORE CLOUDINESS IS EXPECTED TONIGHT AS
THE UPPER LEVEL RIDGE MOVES OFF THE EAST COAST AND A SOUTHWEST
FLOW ALOFT BRINGS IN MORE MOISTURE. CLOUDS WILL HELP TO HOLD
TEMPERATURES UP OVERNIGHT...WITH LOWS IN THE MID 40S TO LOWER 50S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AN UPSTREAM UPPER LEVEL CUTOFF LOW CURRENTLY OVER NEW MEXICO WILL
SLOWLY PUSH EASTWARD ACROSS THE SOUTHERN PART OF THE COUNTRY
THURSDAY...THEN OPEN UP AND LIFT ACROSS THE SOUTHEASTERN STATES
FRIDAY.
WEAK ISENTROPIC LIFTING DEVELOPS IN WARM ADVECTION DURING THE DAY
THURSDAY. KEPT A MENTION OF SLIGHT CHANCE POPS FOR THURSDAY...MAINLY
ACROSS THE WESTERN HALF OF THE FORECAST AREA.
THE ECMWF IS THE MOST PROGRESSIVE WITH THE NAM BEING A BIT SLOWER
AND THE GFS BEING THE SLOWEST OF ALL GUIDANCE. DISCOUNTED THE GFS
SOLUTION AT THIS TIME GIVEN ITS LARGE CHANGE FROM PREVIOUS RUNS
AND AS IT IS AN OUTLIER AMONG ALL GUIDANCE AND LEANING TOWARDS THE
NAM TIMING. KEPT INCREASING POPS THURSDAY NIGHT WITH CATEGORICAL
POPS EARLY FRIDAY...AND DIMINISHING POPS ON FRIDAY AFTERNOON.
THUNDER IS POSSIBLE GIVEN MARGINAL INSTABILITY.
TEMPERATURES ON THURSDAY WILL BE WELL ABOVE NORMAL WITH HIGHS IN THE
70S AND OVERNIGHT LOWS IN THE UPPER 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE EXTENDED FORECAST FEATURES DRY WEATHER WITH NEAR TO SLIGHTLY
BELOW NORMAL TEMPERATURES OVER THE WEEKEND...FOLLOWED BY A WEAK
WARMING TREND ON TUESDAY.
ANOTHER UPPER TROUGH AND ACCOMPANYING SURFACE COLD FRONT WILL PUSH
THROUGH THE OH/TN VALLEYS ON SATURDAY AND SHIFT OFF THE COAST BY
SUNDAY. THERE WILL BE LITTLE MOISTURE AVAILABLE FOR THE QUICK
MOVING TROUGH TO WORK WITH AS PRECIPITABLE WATER VALUES WILL BE
AROUND A HALF INCH SATURDAY AND FALL BELOW A QUARTER INCH ON SUNDAY.
A QUICK REINFORCING SHOT OF COLD AIR WILL ARRIVE FOR SUNDAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE AS THE UPPER TROUGH AXIS PASSES
OVERHEAD.
TEMPERATURES ON SATURDAY WILL RANGE FROM THE UPPER 50S NORTHERN
MIDLANDS TO LOWER 60S IN THE EASTERN MIDLANDS AND CSRA. SATURDAY
NIGHT UNDER COLD ADVECTION OVERNIGHT LOWS WILL FALL INTO THE LOWER
AND MID 30S AS HIGH PRESSURE BUILDS INTO THE REGION. SUNDAY LOOKS
TO BE THE COLDEST DAY DESPITE PLENTY OF SUNSHINE WITH HIGHS SLIGHTLY
BELOW NORMAL IN THE 50S AND A COLD NIGHT IS EXPECTED SUNDAY NIGHT
WITH HIGH PRESSURE CENTERED OVER THE FORECAST AREA. SUNDAY NIGHT
LOWS SHOULD FALL INTO THE 20S.
EARLY NEXT WEEK THE MID LEVEL FLOW BECOMES MORE ZONAL AND A
DAMPENING TROUGH MOVING THROUGH THE FLOW WILL PASS OVER THE AREA ON
TUESDAY. WILL KEEP A DRY FORECAST AT THIS TIME GIVEN UNCERTAINTY ON
DAY 7...BUT TEMPERATURES WILL REBOUND AND WARM AS SOUTHERLY FLOW
RETURNS.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
PATCHY DENSE FOG HAS DEVELOPED OVER AUGUSTA BUSH FIELD AND AT
ORANGEBURG AIRPORTS THIS MORNING. DURATION OF FOG IS SHORT WITH
VISIBILITY IMPROVING AS FAST AS IT DETERIORATES. THIS IS DUE
PRIMARILY TO LOCAL EFFECT...EXCEPT PATCHES OF FOG OVER NORTHEAST
AND EAST CENTRAL SOUTH CAROLINA ARE INFLUENCING THE VISIBILITY AT
ORANGEBURG. ADDED TEMPO IFR VISIBILITY AT BOTH LOCATIONS. OTHER
TERMINALS SHOULD REMAIN FREE OF FOG THIS MORNING.
VFR CONDITIONS WILL RETURN ACROSS ALL LOCATIONS LATER THIS
MORNING AND REMAIN FOR THE REST OF WEDNESDAY. HOWEVER APPROACHING
STORM SYSTEM WILL SPREAD CLOUDS ACROSS THE REGION LATER THIS
AFTERNOON...WITH CEILINGS LOWERING INTO 6Z THURSDAY. VISIBILITY
WILL ALSO BE AFFECTED AS WELL. THIS IS INDICATED IN THE TERMINAL
FORECASTS...WITH MVFR VISIBILITY POSSIBLE BY 6Z AT ALL LOCATIONS.
EXTENDED AVIATION OUTLOOK...IFR CONDITIONS MAY OCCUR EARLY THURSDAY
MORNING THROUGH FRIDAY MORNING AS THE STORM SYSTEM MOVES ACROSS
THE AREA.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 7 AM EST THIS MORNING FOR SCZ015-016.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1133 PM CST TUE JAN 24 2012
.AVIATION...
GENERALLY VFR CONDITIONS WITH PERIODS OF MVFR CONDITIONS DUE TO
GROUND FOG BETWEEN 06-14Z TONIGHT. SCATTERED TO BROKEN COVERAGE OF
MID TO HIGH CLOUDS TO STREAM ACROSS THE AREA INTO EARLY AFTERNOON
ON WEDNESDAY FROM SOUTH PLAINS DISTURBANCE. WINDS TO BE LIGHT TO
CALM UNTIL 14Z THAT SUPPORTS SOME TERMINALS VISIBILITIES TO DROP
TO 2-5 MILES IN FOG. VEIL OF HIGH CLOUDS SUGGESTS DENSE FOG IS NOT
LIKELY BY NOT ALLOWING FOR GOOD RADIATIONAL COOLING. VISIBILITIES
TO IMPROVE BY MID TO LATE MORNING IF NOT ALREADY 7 MILES TO 7 PLUS
MILES AS SE TO E WINDS OF 5-10 MPH OCCUR. ..NICHOLS..
&&
.PREV DISCUSSION... /ISSUED 310 PM CST MON JAN 24 2012/
SYNOPSIS...
12Z UA ANALYSIS HAS AN OCCLUDED EXTRATROPICAL CYCLONE OVER JAMES BAY
WITH AN 850MB COLD FRONT INTO THE OHIO VALLEY AND BACK INTO NORTHERN
MISSOURI. A RESPECTABLE SHORTWAVE WAS MOVING EAST OUT OF THE CENTRAL
ROCKIES WHILE ANOTHER STRONG STORM SYSTEM ORGANIZES OVER NEW MEXICO.
SATELLITE TRENDS THROUGH MID AFTERNOON SHOW CLEARING BEHIND A
DEPARTING SHORTWAVE ACROSS THE WESTERN GREAT LAKES WHILE MOISTURE
REMAINS TRAPPED UNDER THE INVERSION ACROSS IOWA. HIGH AND MID CLOUDS
WERE STREAMING EAST FROM THE PLAINS IN ADVANCE OF THE SYSTEMS IN THE
CENTRAL AND SOUTHERN ROCKIES.
18Z SFC ANALYSIS HAS HIGH PRESSURE FROM MINNESOTA THROUGH CENTRAL
IOWA AND THEN INTO THE LOWER MISSISSIPPI VALLEY. A WEAK LOW WAS
NORTH OF KVTN WITH TROFS EXTENDING NORTH AND SOUTH OF IT. THE
SOUTHERN STREAM STORM SYSTEM WAS IN THE BIG BEND OF TEXAS. DEW
POINTS WERE IN THE TEENS AND 20S ACROSS MUCH OF THE MIDWEST AND
PLAINS WITH 30S AND HIGH DEW POINTS FROM THE OHIO VALLEY WEST INTO
THE SOUTHERN PLAINS.
SHORT TERM...TONIGHT AND WEDNESDAY...
BASED ON SATELLITE CLOUDS TRENDS...THOSE AREAS THAT ARE STILL CLOUDY
WILL LIKELY REMAIN SO THROUGH SUNSET. THE PROXIMITY OF THE SFC RIDGE
COMBINED WITH THE ARRIVAL OF HIGH CLOUDS SHOULD KEEP THOSE CLOUDS IN
PLACE THROUGH SUNSET.
UNFORTUNATELY...THE STRAIGHT FORWARD FCST OF DRY CONDITIONS FOR
TONIGHT/WEDNESDAY HAS BECOME MORE COMPLICATED.
STRONG WAA FROM THE SFC TO 850MB IS OCCURRING IN THE PLAINS FROM A
LLJ WHICH IS RESULTING IN CONVERGENCE ACROSS NORTHERN KS/SOUTHERN NE
WHICH IS AIDING IN CLOUD DEVELOPMENT. RUC TRENDS IN WHICH THE
WRF/GFS AGREE SHOWS 850-700MB AND EVENTUALLY 1000-850MB CONDENSATION
PRESSURE DEFICITS LOWERING LATER THIS AFTERNOON DUE TO STRONG
FRONTOGENETICAL FORCING INDICATING PRECIPITATION. TRENDS FROM THE
RUC AND OTHER MODELS ARE TO MOVE THIS WING OF WAA PRECIPITATION INTO
IOWA THIS EVENING WITH A NORTHEAST MOVEMENT OVERNIGHT. THE HEAVY
RAIN AND LIFT TOOLS SHOW A SIMILAR SIGNAL. IF SUCH A SCENARIO WAS
OCCURRING ROUGHLY 5 MONTHS FROM NOW THESE SIGNALS WOULD POINT TO AN
MCS DEVELOPING IN THE PLAINS AND MOVING NORTHEAST.
THE WRF/GFS SHOW THE LOWEST 850-700MB CONDENSATION PRESSURE DEFICITS
JUST MISSING THE CWFA VERY LATE TONIGHT AND WEDNESDAY MORNING. THE
1000-850MB CONDENSATION PRESSURE DEFICITS ARE HIGHER SUGGESTING
ENOUGH DRY AIR WOULD BE IN PLACE TO PREVENT ANY PRECIPITATION FROM
HAPPENING. HOWEVER...SINCE THE MODELS ARE NOT HANDLING THE CURRENT
LOW CLOUDS ONE MUST BE CAUTIOUS ON THIS ASSUMPTION. GIVEN THE TRENDS
OF THE 18Z WRF RUN...WILL GO WITH THE IDEA THAT THE CWFA WILL REMAIN
DRY TONIGHT. HOWEVER...I WOULD NOT BE SURPRISED IF FLURRIES
DEVELOPED FROM HWY 20 ON NORTH AFTER 3 AM.
TEMPERATURES SHOULD QUICKLY DROP WITH SUNSET IN THE CLEAR AREAS THIS
EVENING. AS THE HIGH AND MID LEVEL CLOUDS ARRIVE THE DROP OFF SHOULD
LEVEL OFF AND MAY EVEN BEGIN A SLOW RISE THROUGH SUNRISE.
WEDNESDAY...FLURRIES MAY OR MAY NOT BE OCCURRING ALONG/NORTH OF HWY
20 DURING THE MORNING HOURS. OTHERWISE...DRY CONDITIONS WILL BE SEEN
THROUGH THE MORNING WITH PLENTY OF CLOUDS. WEDNESDAY AFTERNOON...THE
PRECIPITATION SHIELD FROM THE SOUTHERN STREAM SYSTEM WILL APPROACH
THE CWFA. CONDENSATION PRESSURE DEFICITS AND THE OVERALL FORCING
SUGGESTS THE NORTHERN LIMIT OF PRECIPITATION SHOULD BE FROM JUST
SOUTH OF KUIN TO ABOUT KAAA IN CENTRAL ILLINOIS. THUS DRY CONDITIONS
ARE EXPECTED ACROSS THE AREA DURING THE AFTERNOON HOURS.
08..
LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY...FORECAST FOCUS
ON A SERIES OF SHORT WAVES MOVING THROUGH THE NORTHWEST FLOW BUT NO
SIGNIFICANT PRECIPITATION EXPECTED AT THIS TIME. TEMPERATURES TO
REMAIN A BIT ABOVE NORMAL BUT A SHOT OF COLDER AIR THIS WEEKEND.
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...SPLIT FLOW INITIALLY KEEPS
SOUTHERN STORM SYSTEM SOUTH OF THE DVN CWA AT MID WEEK.
ECM/GFS/NAM/GEM/UKMET ALL KEEP THE PRECIPITATION ASSOCIATED WITH
THIS SYSTEM SOUTH AND EAST OF THE CWA. PHASING TAKES PLACE CRANKING
UP A DECENT CYCLONE MOVING THROUGH THE OHIO VALLEY AND INTO NEW
ENGLAND LATE THIS WEEK. IN THE WAKE OF THIS SYSTEM NORTHWEST FLOW
TAKES OVER WITH A STRONG TROUGH DIVING INTO THE REGION FRIDAY AND
FRIDAY NIGHT. MOISTURE WILL BE LIMITED BUT ECM/NAM PAINTS THE
POTENTIAL FOR UP TO AN INCH OF SNOWFALL IN OUR SOUTHERN CWA. THE
GFS/GEM ARE MUCH DRIER. HOWEVER THE LOCATION OF THE AXIS OF THIS
SNOWFALL MAY CHANGE DEPENDING ON THE TRACK AND INTENSITY OF A STRONG
VORT MAX EXPECTED TO TRACK ACROSS THE AREA. MAX TEMPERATURES DURING
THIS TIME FRAME SHOULD BE IN THE 30S TO AROUND 40.
THIS WEEKEND...FOLLOWING THE PASSAGE OF THIS TROUGH COLDER AIR DUMPS
INTO THE MIDWEST. WILL BE BRISK ON SATURDAY WITH NORTHWEST WINDS
GUSTING TO 30 MPH PUTTING A BITE IN THE AIR. ANOTHER STRONG TROUGH
AND VORT MAX ARRIVES SATURDAY NIGHT BUT MOISTURE WILL BE EVEN MORE
LIMITED. HOWEVER SCATTERED FLURRIES ARE POSSIBLE DUE TO THE STRENGTH
OF THE SYSTEM BUT FOR NOW WILL NOT MENTION IN THE GRIDS WITH LOW
CONFIDENCE. MIN TEMPS SATURDAY NIGHT WILL DIP TO AROUND 10 ABOVE AT
INDEPENDENCE WITH MOST LOCATIONS IN THE TEENS. COLD ON SUNDAY WITH
MAX TEMPS ONLY IN THE 20S...BUT LOWER 30S IN OUR FAR SOUTH.
EARLY NEXT WEEK...ZONAL FLOW RETURNS WITH MILDER TEMPERATURES
REACHING INTO THE MID 30S NORTH TO MID 40S SOUTH. WAVE IN THE FLOW
TUESDAY INTO TUESDAY NIGHT MAY BRING A ROUND OF LIGHT RAIN TO THE
CWA...POSSIBLY CHANGING TO LIGHT SNOW AT THE TAIL END. THIS IS A
WEEK AWAY SO CONFIDENCE IN THE INTENSITY/TIMING AND QPF IS LOW.
HAASE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
251 AM CST WED JAN 25 2012
.DISCUSSION...
.SHORT TERM...
AT 00Z WEDNESDAY A 500MB UPPER LOW WAS LOCATED NEAR EL PASO
TEXAS. NORTH OF THIS UPPER LOW A 700MB BAROCLINIC ZONE EXTENDED
ACROSS EASTERN COLORADO. AS OF 6Z THE RUC AND NAM INDICATED THAT THIS
700MB BAROCLINIC WAS CURRENTLY MOVING EAST ACROSS WESTERN KANSAS
WITH SATELLITE LOOP INDICATING WARMING CLOUD TOPS AS THIS
BAROCLINIC ZONE PASSES. CLEAR SKIES HAD ALREADY DEVELOPED WEST OF
THE 500MB DEFORMATION ZONE WHICH AT 06Z WAS STARTING TO CROSS INTO
WESTERN KANSAS. THE LIGHT PRECIPITATION THAT HAD DEVELOPED OVER
PORTIONS OF SOUTH CENTRAL KANSAS EARLIER TONIGHT WILL SLOWLY SHIFT
SOUTHEAST THROUGH THE REMAINDER OF THE MORNING AS THE MID LEVEL
BAROCLINIC ZONE CROSSES INTO SOUTH CENTRAL KANSAS BETWEEN 09Z AND 12Z
WEDNESDAY. CLOUD COVER WILL ALSO GRADUALLY GIVE WAY TO CLEAR SKIES
BY MID DAY IN THE SOUTHEAST AS THE 500MB DEFORMATION EXITS THE
AREA BASED ON 00Z NAM AND 06Z RUC.
THE NAM AND GFS MODEL SOUNDINGS AT 00Z THURSDAY, AS WELL AS ECMWF
6HOUR MAX TEMPERATURE FORECAST WERE ALL SUGGESTING THAT HIGHS
TODAY WILL REBOUND BACK INTO THE LOWER 50S ACROSS WESTERN KANSAS.
IN THE EAST WHERE CLOUDS WILL BE SLOWER TO ERODE THE HIGHS ARE
EXPECTED TO CLIMB TO AROUND 50 BUT IF SKIES CLEAR SOONER IT COULD
BE SEVERAL DEGREES WARMER BASED ON THE 875MB MIX DOWN TEMPERATURE.
TONIGHT A WEAK FRONT WILL MOVE INTO WESTERN KANSAS AS AN UPPER
LEVEL SHORT WAVE TROUGH WHICH WAS ASSOCIATED WITH THE LEFT EXIT
REGION OF A 250MB JET STREAK THAT LOCATED ACROSS WASHINGTON STATE
AT 00Z WEDNESDAY QUICKLY CROSSES THE NORTHERN PLAINS. THE
925-850MB 24HR TEMPERATURE CHANGE FROM 00Z THURSDAY TO 00Z FRIDAY
WAS ONLY A FEW DEGREES OF EACH OTHER SO GIVEN LIMITED CLOUD COVER
EXPECTED THURSDAY AFTERNOON WILL FAVOR HIGHS VERY SIMILAR THOSE
TODAY IN THE WEST. EAST/SOUTHEAST OF DODGE CITY HOWEVER GIVEN MORE
SUN AND BETTER MIXING POTENTIAL THE HIGH SHOULD BE A LITTLE WARMER
BASED ON THE FORECAST 00Z FRIDAY MODEL SOUNDINGS.
.LONG TERM /FRIDAY THROUGH WEDNESDAY/
FRIDAY WILL BE BREEZY AT LEAST AND PROBABLY WINDY AS A COLD FRONT
SWEEPS THROUGH THE AREA IN THE MORNING. NORTHWEST FLOW ALOFT WILL BE
INCREASING WITH TIME AS WELL AS THE UPPER JET FROM THE WEST COAST
RIDGE MOVES INTO THE CENTRAL HIGH PLAINS. THE FAST MOVING FRONT
SHOULD BRING A COOLER AIRMASS SOUTHWARD ALONG WITH WEAK FRONTOGENESIS
BUT THE MOISTURE APPEARS RATHER LIMITED. THE BEST QPF FIELDS IN THE
NUMERICAL MODELS LOOK TO BE BETTER ASSOCIATED WITH THE UPPER JET`S
LEFT FRONT EXIT REGION ACROSS THE MISSOURI VALLEY, AND THE BETTER
UPSLOPE FLOW/HIGHER TERRAIN OF EASTERN COLORADO. THEREFORE WE ARE
NOT IMPRESSED WITH PRECIPITATION CHANCES, AND WILL LEAVE THE 20
PERCENT CHANCES FOR RAIN OF FRIDAY ACROSS PORTIONS OF THE FORECAST
AREA. SURFACE HIGH PRESSURE SHOULD THEN DRIFT INTO NORTHERN TEXAS
AND OKLAHOMA ON SATURDAY , WHICH WOULD PRODUCE A LIGHT WESTERLY WIND
FIELD OVER SOUTHWEST KANSAS, AND SIMILAR TEMPERATURES ON BOTH DAYS
IN THE 40S. DUE TO THE LACK OF MOISTURE, THERE DOESN`T APPEAR TO BE
SIGNIFICANT CLOUD COVER DURING THIS PERIOD, BUT WITH THE UPPER JET
BUCKLED ACROSS THE PLAINS, SOME CS MIGHT BE EXPECTED. OVERNIGHT
TEMPERATURES WILL EASILY FALL BELOW FREEZING GIVEN THE COLD 850 MB
TEMPERATURE FIELDS AND THE RELATIVELY LIGHT WINDS. THE SYNOPTIC
PATTERN WILL CHANGE HEADING INTO THE LATER PART OF THE WEEKEND AS
THE UPPER WEST COAST RIDGE PUSHES FARTHER EAST AND THE LEAD UPPER
JET DIVES INTO THE MISSOURI VALLEY. THAT WILL DRAW WARMER AIR FROM
THE HIGHER TERRAIN OF NEW MEXICO AND COLORADO SUNDAY NIGHT AND INTO
MONDAY AND ALLOW TEMPERATURES TO WARM BY ABOUT 10-20 DEGREES DURING
THE DAYTIME HEADING INTO MONDAY AFTERNOON AND ESPECIALLY TUESDAY.
BOTH MODELS PRODUCE A SHORTWAVE TROUGH MOVING THROUGH THE AREA ON
MONDAY, IN A DRY AND STABLE ATMOSPHERE WHICH WILL MAINLY BRING ABOUT
A SURFACE WIND SHIFT DURING THE DAY FROM SOUTHEAST TO NORTHWEST.
&&
.AVIATION...
FOR THE 06Z TAF ISSUANCE...
VFR CEILINGS WILL PERSIST THROUGH THE LATE NIGHT HOURS BUT SHOULD BE
MOVING EAST OF THE TAF SITES BY 12Z. LIGHT RAIN SHOULD REMAIN SOUTHEAST
OF DODGE CITY THROUGH THE NEXT FEW HOURS ALTHOUGH A FEW SPRINKLES
COULD OCCUR. NORTH WINDS WILL BE GUSTY AT TIMES TO 20-25 KNOTS BUT
SHOULD ALSO BE DECREASING BY 12Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 51 27 52 28 / 0 0 0 0
GCK 51 26 51 28 / 0 0 0 0
EHA 51 31 51 29 / 0 0 0 0
LBL 51 28 53 27 / 0 0 0 0
HYS 50 26 52 28 / 0 0 0 10
P28 50 30 54 28 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN18/33/02
AREA FORECAST DISCUSSION...UPDATED FOR 06Z TAFS
NWS TWIN CITIES/CHANHASSEN MN
1055 PM CST TUE JAN 24 2012
.AVIATION.../06Z TAF ISSUANCE/
-SN HAS BECOME MORE WIDESPREAD THAN EARLIER EXPECTED AHEAD OF UPPER
TROF NOW MOVING INTO E SODAK INTO NC NEB. MPX AND SURROUNDING
RADARS ALSO SHOW PCPN BLOSSOMING. SOME CONCERN OF A PERIOD SLEET OR
-FZRA AS PCPN BEGINS...BUT THIS SHOULD REMAIN SOUTH OF ANY TAF
SITES. ANY -SN AT AXN SHUD BE BEFORE 08Z. EXPCT A PERIOD OF IFR
VSBYS IN SNOW AT STC/RWF/MSP/RNH OVRNITE WITH THESE CONDS AT RWF/STC
GNRLY BFR 09Z. CIGS SHUD GNRLY LOWER TO MVFR WITHIN AN HOUR OR SO
OF BEGINNING OF -SN. SATELLITE IMAGERY SHOWING A FAIRLY EXPANSIVE
AREA OF MVFR TO IFR CIGS BEHIND THE UPPER TROF...ACROSS E AN CNTRL
SODAK INTO NEB. 925MB RN ON 00Z NAM SEEMS TO HANDLE THIS FAIRLY
WELL WHICH WOULD KEEP MVFR CIGS ACRS MUCH OF AREA WELL INTO
WEDNESDAY.
KMSP...MPX RADAR HAS BEEN SHOWING -SN BLOSSOMING ARND AREA AND
EXPECT THAT MVFR VSBYS IN -SN SHUD BEGIN NEAR 06Z TAF TIME. HAVE A
WINDOW OF VSBYS 2SM FROM 08Z-12Z. AFTER SNOW ENDS BY 13Z OR
SO...SHUD MAINTAIN MVFR CIGS INTO MID AFTN.
&&
.DISCUSSION...ISSUED 240 PM CST
OVERALL THE LARGE SCALE PATTERN IS FAIRLY BENIGN WITH RESPECT TO
ITS IMPACT ON SENSIBLE WEATHER IN OUR AREA OVER THE UPCOMING WEEK.
WEST TO NORTHWEST UPPER FLOW WILL PREDOMINATE... BRINGING PERIODIC
MOISTURE DEFICIENT SHORTWAVES THROUGH OUR AREA WHICH WILL
GENERALLY AMPLIFY ONCE THEY GET EAST OF OUR LONGITUDE.
TEMPERATURES LOOK TO BE A BIT ABOVE NORMAL FOR THE MOST PART...
WITH THE COLDEST PERIOD AND PERHAPS SOME BELOW NORMAL READINGS IN
STORE FOR SATURDAY INTO MONDAY. LATEST SATELLITE IMAGERY AND RADAR
DATA SHOW CLOUDS STREAMING IN FROM THE WEST AT THE CURRENT TIME...
AHEAD OF A SHORTWAVE TROUGH WHICH CAN BE SEEN ON WATER VAPOR
MOVING INTO THE DAKOTAS. THERE HAVE BEEN A FEW OBSERVATIONS OF
LIGHT RAIN AND SNOW AHEAD OF THIS FEATURE... ALTHOUGH MUCH OF THE
ACTIVITY IS STILL ALOFT AT THE CURRENT TIME. GIVEN THE LACK OF
GOOD MOISTURE RETURN AHEAD OF THIS FEATURE... THE 12Z GUIDANCE
FROM THE GFS AND NAM ARE UNDERSTANDABLY UNDERWHELMING IN THEIR
PRODUCTION OF PCPN AS THIS SYSTEM MOVES THROUGH THE AREA TONIGHT
INTO WEDNESDAY MORNING... ALTHOUGH ALL MANAGE TO SQUEEZE OUT A
LITTLE BIT OF PCPN GIVEN THE COMBINATION OF SOME DECENT ISENTROPIC
LIFT AND DPVA AHEAD OF THE TROUGH. THE HIGH RESOLUTION
SOLUTIONS... INCLUDING THE HRRR... ALSO SUGGEST A PERIOD OF SOME
LIGHT PCPN TONIGHT INTO MONDAY MORNING... WITH A BETTER CO-LOCATION
OF SATURATION AND FORCING OVER THE SOUTHERN PART OF THE CWFA.
RAISED POPS SOME WITH THIS SYSTEM... BUT KEPT THEM IN THE CHANCE
RANGE SINCE ALTHOUGH IT SEEMS LIKELY THAT IT WILL PRECIPITATE IT
IS STILL QUESTIONABLE AS TO WHETHER OR NOT IT WILL MEASURE.
ANOTHER SMALL CONCERN AS THE SYSTEM MOVES THOUGH TONIGHT IS
WHETHER THE ELEVATED WARM NOSE... WHICH LOOKS LIKE IT WILL BE
AROUND 900-925MB... WILL BE SUFFICIENT TO CAUSE MELTING OF
HYDROMETEORS AS THEY DESCEND TO THE SURFACE. THE NAM IS THE MOST
BULLISH IN WARMING TEMPERATURES ALOFT... WHILE THE GFS AND RUC ARE
NOT AS STRONG WITH THE WARMING. THE UPSTREAM 12Z SOUNDING AT OMAHA
DEFINITELY SHOWED AN ABOVE FREEZING LAYER... SO THE QUESTION WILL
BE WHETHER IT IS ABLE TO COOL MUCH TOWARD THE WET BULB GIVEN THE
DRYNESS IN THE LAYER... OR IF MOISTURE ADVECTION OVERWHELMS THINGS
AND WE SIMPLY SEE THE WARM NOSE SATURATE WITH LITTLE CHANGE IN
TEMPERATURE. LOOKING AT THE UPSTREAM MIXING RATIOS IN THE
SOUTHWEST-NORTHEAST ORIENTED AXIS AHEAD OF THE TROUGH... FEEL
THERE SHOULD BE A TENDENCY TO MOISTEN IN THAT LAYER QUITE A BIT...
SO THINK THERE WILL BE POTENTIAL FOR AN ABOVE FREEZING WARM LAYER
FOR A TIME TONIGHT AS THE PCPN MOVES THROUGH... PARTICULARLY ALONG
AND SOUTH OF I-90. WITH THAT IN MIND... INCLUDING A MENTION OF
SOME IP ALONG WITH SN OVER THE SOUTHERN PART OF THE AREA FOR TONIGHT.
ONCE TONIGHT/S SYSTEM GETS OUT OF OUR HAIR... THINGS LOOK TO BE
FAIR AND DRY THROUGH THURSDAY... WITH THE NEXT CHANCE FOR ANY
MEANINGFUL PCPN HOLDING OFF UNTIL FRIDAY. WARM ADVECTION WILL
INCREASE ACROSS THE AREA TOMORROW AFTERNOON INTO TOMORROW
EVENING... WITH A FRONTAL SLIDING ACROSS THE STATE TOMORROW NIGHT.
THIS FRONT IS THE ONE POTENTIAL PCPN PRODUCER PRIOR TO FRIDAY...
BUT AT THIS TIME IT LOOKS LIKE WE WILL BE HARD PRESSED TO SEE
SUFFICIENT MOISTURE WORK INTO THE AREA PRIOR TO ITS PASSAGE TO
WRING OUT ANY PCPN. IT/S POSSIBLE THAT LATER FORECASTS WILL NEED
TO INCLUDE SOME FLURRIES OVER THE NORTHERN PART OF THE CWFA FOR
TOMORROW NIGHT... BUT FOR NOW THE MOST LIKELY SCENARIO STILL LOOKS
TO BE A DRY FROPA. A BRIEF COOL DOWN IS EXPECTED THURSDAY THROUGH
THURSDAY NIGHT AS HIGH PRESSURE DROPS SOUTHEAST INTO THE CENTRAL
PLAINS AND NORTHWEST FLOW BRINGS A QUICK SHOT OF SOME MODIFIED
ARCTIC AIR INTO THE REGION. A SHORTWAVE THEN LOOKS TO SWING
THROUGH THE AREA ON FRIDAY... WITH THE ECMWF AND GFS AND
REASONABLE AGREEMENT... ALTHOUGH THE ECMWF SOLUTION IS A BIT MORE
AMPLIFIED AND THEREFORE SLOWER AND ACCOMPANIED BY MORE IN THE WAY
OF PCPN. IN EITHER CASE... THERE LOOKS TO BE ENOUGH FORCING AND
DEEP LAYER SATURATION TO SUPPORT A MENTION OF POPS. UNFORTUNATELY
THE DIFFERENCES IN TIMING AND UNCERTAINTY REQUIRE BLANKETING A
LONGER PERIOD OF TIME WITH POPS THAN WHAT WILL EVENTUALLY OCCUR IN
REALITY... SO INCLUDED SOME CHANCE POPS FOR SNOW FROM FRIDAY INTO
SATURDAY FROM WEST TO EAST ACROSS THE AREA. LATER FORECASTS SHOULD
CERTAINLY BE ABLE TO NARROW AND FOCUS THIS TEMPORAL WINDOW ONCE
THINGS COME INTO BETTER AGREEMENT.
A DECENT SLUG OF COLD AIR LOOKS TO DROP INTO THE REGION AFTER
SATURDAY/S SYSTEM MOVES BY... BUT IT WILL BE SHORT-LIVED AS THE
GFS... ECMWF... AND THEIR RESPECTIVE ENSEMBLE ALL SUPPORT THE IDEA
OF A SUBSTANTIAL RIDGE BUILDING TO OUR WEST BY THE SUNDAY-MONDAY
TIME FRAME. RETURN FLOW WILL START TO BRING IN WARMER TEMPERATURES
ASSOCIATED WITH THIS RIDGE BY THE SUNDAY NIGHT INTO MONDAY TIME
FRAME... WITH SOME PCPN POSSIBLY DEVELOPING IN THE AREA OF
ISENTROPIC ASCENT DURING THAT TIME FRAME. A SOMEWHAT UNSETTLED
PATTERN THEN LOOKS TO PERSIST INTO TUESDAY AS THE NEXT SHORTWAVE
AND ASSOCIATED COLD FRONT WORK TOWARD THE AREA. ALL OF THIS WINDS
UP LEADING TO THE INCLUSION OF SOME CHANCE POPS FOR MUCH OF THE
PERIOD FROM SUNDAY NIGHT INTO TUESDAY... PARTICULARLY OVER THE
NORTHERN AND EASTERN PART OF THE CWFA WHERE BETTER SATURATION
ALONG THE SLOPED FRONTAL ZONE IS MORE LIKELY TO TAKE PLACE. IN
ADDITION... THINGS COULD CERTAINLY WARM ENOUGH BY MONDAY NIGHT OR
TUESDAY FOR SOME PTYPE ISSUES... SO INCLUDED SOME RN/SN MENTION BY
TUESDAY TO HIGHLIGHT THAT POSSIBILITY.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/BAP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
318 AM CST WED JAN 25 2012
.SHORT TERM...TODAY THROUGH FRIDAY
318 AM CST WED JAN 25 2012
MAIN FORECAST CONCERNS INCLUDE SNOW CHANCES TODAY...AND THEN
TEMPERATURES THROUGH THE SHORT TERM.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MID-LEVEL TROUGH
EXTENDING FROM EASTERN ND THROUGH NEBRASKA. ISENTROPIC LIFT AHEAD OF
THIS TROUGH WAS PRODUCING AREAS OF LIGHT SNOW ACROSS PORTIONS OF
SOUTHERN MN INTO WEST-CENTRAL AND NORTHWEST WI PER THE RADAR
MOSAIC/SURFACE OBSERVATIONS. MOST OF THIS WAS VERY LIGHT SNOW WITH
VISIBILITIES IN THE 7-10SM RANGE...BUT THERE WERE POCKETS OF 1-2SM
-SN WHERE THERE WAS MORE VIGOROUS SATURATION OF THE COLUMN.
OTHERWISE...WITH CLOUDS AND WEAK SOUTHERLY SURFACE FLOW...
TEMPERATURES AT 3 AM WERE IN THE UPPER TEENS TO LOWER 20S.
25.00Z NAM/GFS AS WELL AS THE 25.03Z SREF ALL IN GOOD AGREEMENT WITH
OVERALL UPPER LEVEL/SURFACE FEATURES THROUGH THE SHORT TERM.
FOR TODAY...MODELS CONTINUE TO SHOW ISENTROPIC LIFT THROUGH THIS
MORNING ALONG AND NORTH OF I-90 THROUGH THIS MORNING...THEN SHIFTS
NORTH OUT OF THE AREA BY THIS AFTERNOON AS THE MID-LEVEL TROUGH
BEGINS TO FILL/WEAKEN AS IT MOVES THROUGH. AS SUCH...WILL CONTINUE
-SN CHANCES MAINLY ALONG/NORTH OF I-90 THIS MORNING...THEN WILL GO
DRY THIS AFTERNOON. ANY SNOWFALL EXPECTED TO BE MINIMAL WITH PERHAPS
A TENTH OF AN INCH OR TWO TENTHS AT MOST. MOSTLY CLOUDY CONDITIONS
EXPECTED THROUGH THE REMAINDER OF THE DAY WITH PERHAPS SOME CLEARING
ACROSS THE SOUTH LATE IN THE AFTERNOON. OTHERWISE...AFTER A RELATIVELY
WARMER START THIS MORNING...HIGHS TODAY SHOULD TOP OF IN THE LOWER
30S.
MILDER TEMPERATURES EXPECTED THROUGH THURSDAY IN WARM AIR ADVECTION
AHEAD OF A DEEP LOW PRESSURE SYSTEM MOVING THROUGH CENTRAL CANADA.
NAM INDICATING 925MB TEMPERATURES WARMING TO 0-5C THROUGH MIDDAY
THURSDAY. A COLD FRONT WILL THEN BE MOVING INTO THE AREA BY
MIDDAY...BUT BULK OF THE COLD AIR ADVECTION LOOKS LIKE IT WILL
FOLLOW NORMAL MID-LATE AFTERNOON DIURNAL T-CURVE DOWNSWING. SO
EXPECTING HIGHS THROUGH ABOUT MIDDAY...THEN FALLING THROUGH THE
AFTERNOON. BOTTOM LINE...LOOKS LIKE HIGHS THURSDAY SHOULD TOP OFF IN
THE MID-UPPER 30S.
SKIES EXPECTED TO CLEAR THROUGH MIDNIGHT ACROSS THE AREA THROUGH
THURSDAY EVENING WITH JUST A BRIEF SHOT OF COLD AIR ADVECTION MAINLY
EAST OF THE MISSISSIPPI RIVER. AFTER 06Z THURSDAY...BUFKIT SOUNDINGS
SHOW INCREASING MID/HIGH LEVEL CLOUDS MOVING IN MAINLY WEST OF THE
MISSISSIPPI RIVER IN ADVANCE OF A WEAK MID-LEVEL TROUGH/SURFACE LOW
PRESSURE MOVING ACROSS THE NORTHERN PLAINS.
ON FRIDAY...WILL CONTINUE TO SEE THAT WEAK MID-LEVEL TROUGH/SURFACE
LOW RIPPLE SOUTHEAST ACROSS IA INTO NORTHERN IL. BUFKIT COMPARISONS
OF THE GFS/NAM SHOW DIFFERING OPINIONS ON DEGREE OF COLUMN
SATURATION. THE GFS AT THIS POINT IS A BIT DRIER IN THE LOWER LEVELS
WHEREAS THE NAM WANTS TO SATURATE/PRECIPITATE MAINLY ALONG AND SOUTH
OF I-94. FOR NOW WILL CARRY 30 POPS FOR THIS AREA.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
318 AM CST WED JAN 25 2012
25.00Z GFS/ECMWF BOTH SHOW COLD AIR ADVECTION WITH DEEPENING MID-
LEVEL TROUGH DROPPING INTO THE REGION FRIDAY NIGHT THROUGH SATURDAY
FOR A CHANCE OF -SN. HIGHS SATURDAY EXPECTED TO FALL BACK TO NEAR
NORMAL LEVELS IN THE MID/UPPER 20S. SURFACE RIDGE OF HIGH PRESSURE
SLIDES ACROSS THE AREA ON SUNDAY FOR MOSTLY SUNNY SKIES...BUT HIGHS
ONLY EXPECTED TO TOP OFF IN THE TEENS TO LOWER 20S. MODERATING
TEMPERATURES THEN EXPECTED MONDAY AS A WEAK LOW AND WARM FRONT PUSH
OUT OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI RIVER REGION.
ISENTROPIC LIFT AHEAD OF THE LOW AND WARM FRONT WILL PRODUCE A
SLIGHT CHANCE OF -SN. OTHERWISE...LOOKING FOR HIGHS PUSHING INTO THE
MID 20S TO LOWER 30S. ON TUESDAY...THE WARM FRONT LOOKS TO LINGER
ACROSS THE AREA FOR A CHANCE OF RAIN OR SNOW AS HIGHS TOP OFF IN THE
30S.
&&
.AVIATION...THROUGH 06Z THURSDAY
1126 PM CST TUE JAN 24 2012
MVFR/IFR STRATUS DECK THAT WAS OVER SOUTHERN MINNESOTA...NORTHERN
IOWA AND PORTIONS OF SOUTHWEST WISCONSIN HAS COMPLETELY
DISSIPATED...LIKELY DUE TO AN INFLUX OF LOW LEVEL DRY AIR FROM
SOUTHEAST IOWA. IN ADDITION...MUCH OF THE MVFR BR HAS DISSIPATED.
WITH THE LACK OF STRATUS AND 900-925MB WINDS PROMOTING DRY AIR TO
KEEP ADVECTING OUT OF EASTERN IOWA THROUGH THE DAY THURSDAY...HAVE
WENT WITH A MUCH MORE OPTIMISTIC TAF FORECAST FOR BOTH SITES. THIS
IS EVEN IN SPITE OF SOME PRECIPITATION OVER NORTHWEST IOWA AND
SOUTHWEST MINNESOTA POSSIBLY COMING ACROSS...THOUGH EVEN THIS
PRECIPITATION IS FALLING APART. KEPT A -SN MENTION IN THE TAFS FOR
THE MORNING IN CASE IT OCCURS...BUT NO RESTRICTION IN VISIBILITY.
IF SNOW DOES OCCUR...LITTLE IF ANY ACCUMULATION IS EXPECTED. TAF
FORECAST IS NOW VFR THROUGH 06Z PERIOD. ONLY OTHER ITEM OF NOTE IS
A COLD FRONT MOVING INTO WESTERN MINNESOTA AT 06Z THURSDAY. AN
INCREASING PRESSURE GRADIENT AHEAD OF THIS FRONT WILL HELP TO
INCREASE SOUTHERLY WINDS AT BOTH TAF SITES...ESPECIALLY KRST WHERE
UP TO 15 KT SUSTAINED SPEEDS ARE FORECAST. NO CONCERN FOR LOW
LEVEL WIND SHEAR AT THIS TIME...THOUGH THERE IS A CONCERN ABOUT
MOISTURE COMING UP WITH THE WINDS FOR THE EVENING. RIGHT NOW
THINK THE MIXING FROM THE WIND...WARMING AND MOISTURE WILL BALANCE
OUT SUCH THAT NO STRATUS OR BR OCCURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
318 AM CST WED JAN 25 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1126 PM CST TUE JAN 24 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT
300 PM CST TUE JAN 24 2012
MAIN FORECAST CONCERN IS ON SNOW CHANCES LATE TONIGHT INTO WEDNESDAY
MORNING AND THE POSSIBILITY OF SOME MIXED PRECIPITATION...THEN
MAINLY CLOUDS AND TEMPERATURES.
18Z SURFACE ANALYSIS SHOWS HIGH PRESSURE EXTENDING FROM SOUTHERN
ILLINOIS...NORTHWARD INTO SOUTHERN AND CENTRAL MINNESOTA. ONE BAND
OF STATUS MOVED EAST OF THE AREA THIS MORNING...BUT VISIBLE
SATELLITE IMAGERY AND SURFACE REPORTS SHOW ANOTHER AREA OF STRATUS
OVER SOUTHEAST MINNESOTA AND NORTHERN IOWA AS THE MOISTURE IS
TRAPPED UNDER THE SUBSIDENCE INVERSION.
24.12Z MODELS OFFER SIMILAR SOLUTIONS THROUGH THE PERIOD. THERE ARE
SOME MINOR DIFFERENCES...ESPECIALLY IN THE LATER PERIODS WITH THE
STRENGTH OF THE 500MB LOW THAT MOVES ACROSS SOUTHERN CANADA.
DIFFERENCES SUBTLE ENOUGH TO USE A BLEND APPROACH. OVERALL...MAINLY
ZONAL LOW INITIALLY WILL SLOWLY TRANSITIONS TO A MORE NORTHWESTERLY
FLOW BY THURSDAY AND FRIDAY AS UPPER LOW TRANSLATES ACROSS
SOUTHERN CANADA.
IN THE NEAR TERM...ANY BREAK IN THE CLOUDS WILL BE SHORT LIVED
TONIGHT AS SHORTWAVE TROUGH CROSSES THE PLAINS. THIS WILL SPREAD
CLOUDS BACK INTO THE AREA THIS EVENING. MODELS HAVE BEEN
CONSISTENT IN A WEAK AREA OF ISENTROPIC LIFT ACROSS THE WEST AND
NORTH LATE TONIGHT/EARLY WEDNESDAY. VERY WEAK QG
CONVERGENCE...MAINLY ABOVE 700MB AFFECTS THE AREA WITH THE WAVE.
MODELS HAVE BEEN PAINTING SOME VERY LIGHT QPF FROM SOUTHEAST
MINNESOTA INTO NORTH CENTRAL WISCONSIN. BUFKIT SOUNDINGS ALSO
SHOWING A 925MB-875MB WARM NOSE PUSHING INTO SOUTHEAST MINNESOTA
AFTER 09Z. NAM A BIT MORE AGGRESSIVE WITH +1 TO +2 CELSIUS
TEMPERATURES IN THE WARM LAYER...AND GFS CLOSER TO 0 TO +1
CELSIUS. HOWEVER..24.18Z RUC COOLS LAYER BEFORE PRECIPITATING AND
THUS KEEPS IT ALL SNOW. THIS COULD POSE A PRECIPITATION TYPE
PROBLEM...HOWEVER THE PRESENCE OF DRY AIR WILL LIKELY COOL COLUMN
ONCE PRECIPITATION BEGINS PER THE RUC...AND THUS HAVE LEFT IT ALL
SNOW. EVENING SHIFT WILL HAVE TO MONITOR THOUGH FOR THE
POSSIBILITY OF SOME SLEET WITH THE SNOW LATE TONIGHT. DID RAISE
PROBABILITIES A LITTLE TONIGHT...THINKING IT WILL BE MAINLY A NON
ACCUMULATING EVENT...SO ONLY WENT WITH CHANCE PROBABILITIES.
WEDNESDAY THROUGH THURSDAY LOOK QUIET WITH JUST SOME MID CLOUDS
FROM TIME TO TIME. WITH A STRONGER SOUTHWEST LOW LEVEL FLOW AND
925MB TEMPERATURES WARMING TO +1 TO +2 CELSIUS...TEMPERATURES LOOK
TO BE ON THE MILDER SIDE WITH READINGS BACK ABOVE NORMAL. WINDS DO
BECOME MORE WESTERLY THURSDAY AS A TROUGH ROTATES THROUGH THE
AREA...BUT LITTLE IN THE WAY OF COOLING BEHIND IT AND THUS EXPECT
TEMPERATURES TO REMAIN MILD. GIVEN THE SNOW COVER DID NOT GO AS
WARM AS GUIDANCE...BUT WILL SEE READINGS IN THE LOWER TO MIDDLE
30S EACH DAY AND MIDDLE 20S OVERNIGHT.
BY FRIDAY AND FRIDAY NIGHT...A SHORTWAVE ROTATES AROUND THE SOUTHERN
CANADA UPPER LOW WITH AN ASSOCIATED COLD FRONT. BOTH THE GFS AND
ECMWF IS SHOWING SOME WEAK FORCING ACROSS THE AREA AND DID GO WITH
SOME LOWER END SNOW PROBABILITIES.
.LONG TERM...SATURDAY THROUGH TUESDAY
300 PM CST TUE JAN 24 2012
LONGWAVE TROUGH GETS CARVED OUT OF THE FLOW AS 500MB LOW DEEPENS
ACROSS SOUTHERN CANADA SATURDAY AND SUNDAY. THIS WILL ALLOW COLDER
AIR TO FILTER INTO THE AREA...WITH TEMPERATURES FALLING BACK TO
BELOW NORMAL READINGS FOR A BRIEF PERIOD OF TIME. A SHORTWAVE
ROTATING THROUGH THE FLOW MAY BRING SOME LIGHT SNOW CHANCES IN AREAS
NORTH OF INTERSTATE 94 SATURDAY...WITH THE REMAINDER OF THE AREA
REMAINING DRY. TROUGH DOES BEGIN TO PUSH EAST SUNDAY...WITH HEIGHTS
BEGINNING TO RISE ON MONDAY AND TUESDAY. TEMPERATURES WILL MODERATE
MONDAY AND TUESDAY...WITH A DISTURBANCE RIDING DOWN THE FLOW
TUESDAY BRING A CHANCE OF RAIN OR SNOW...AS TEMPERATURES REBOUND
INTO THE MIDDLE 30S.
&&
.AVIATION...THROUGH 06Z THURSDAY
1126 PM CST TUE JAN 24 2012
MVFR/IFR STRATUS DECK THAT WAS OVER SOUTHERN MINNESOTA...NORTHERN
IOWA AND PORTIONS OF SOUTHWEST WISCONSIN HAS COMPLETELY
DISSIPATED...LIKELY DUE TO AN INFLUX OF LOW LEVEL DRY AIR FROM
SOUTHEAST IOWA. IN ADDITION...MUCH OF THE MVFR BR HAS DISSIPATED.
WITH THE LACK OF STRATUS AND 900-925MB WINDS PROMOTING DRY AIR TO
KEEP ADVECTING OUT OF EASTERN IOWA THROUGH THE DAY THURSDAY...HAVE
WENT WITH A MUCH MORE OPTOMISTIC TAF FORECAST FOR BOTH SITES. THIS
IS EVEN IN SPITE OF SOME PRECIPITATION OVER NORTHWEST IOWA AND
SOUTHWEST MINNESOTA POSSIBLY COMING ACROSS...THOUGH EVEN THIS
PRECIPITATION IS FALLING APART. KEPT A -SN MENTION IN THE TAFS FOR
THE MORNING IN CASE IT OCCURS...BUT NO RESTRICTION IN VISIBILITY.
IF SNOW DOES OCCUR...LITTLE IF ANY ACCUMULATION IS EXPECTED. TAF
FORECAST IS NOW VFR THROUGH 06Z PERIOD. ONLY OTHER ITEM OF NOTE IS
A COLD FRONT MOVING INTO WESTERN MINNESOTA AT 06Z THURSDAY. AN
INCREASING PRESSURE GRADIENT AHEAD OF THIS FRONT WILL HELP TO
INCREASE SOUTHERLY WINDS AT BOTH TAF SITES...ESPECIALLY KRST WHERE
UP TO 15 KT SUSTAINED SPEEDS ARE FORECAST. NO CONCERN FOR LOW
LEVEL WIND SHEAR AT THIS TIME...THOUGH THERE IS A CONCERN ABOUT
MOISTURE COMING UP WITH THE WINDS FOR THE EVENING. RIGHT NOW
THINK THE MIXING FROM THE WIND...WARMING AND MOISTURE WILL BALANCE
OUT SUCH THAT NO STRATUS OR BR OCCURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
300 PM CST TUE JAN 24 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
634 AM EST WED JAN 25 2012
.SYNOPSIS...
HIGH PRESSURE CURRENTLY ACROSS THE REGION WILL MOVE OFF THE COAST
THIS EVENING. A WARM FRONT LIFT NORTH ACROSS THE AREA TONIGHT...
BRINGING INCREASING MOISTURE. A LOW PRESSURE SYSTEM WILL AFFECT
THE AREA THURSDAY INTO FRIDAY. DRY HIGH PRESSURE WILL TAKE CONTROL
FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LINGERING LOW LEVEL MOISTURE HAS ALLOWED AREAS OF FOG TO DEVELOP
ACROSS THE MIDLANDS THIS MORNING. THE AREA OF FOG/STRATUS HAS
MOVED INTO THE CENTRAL MIDLANDS. HAVE CANCELLED THE DENSE FOG
ADVISORY FOR THE NORTHERN MIDLANDS.
THE RUC AND NAM20 MODELS INDICATE THE LOW LEVEL MOISTURE TO
LINGER THROUGH THE 12Z-14Z TIME-FRAME. HOWEVER..BOTH MODELS SHOW
A LOW LEVEL JET WHICH PROMOTE MIXING.
HIGH PRESSURE CENTERED OVER THE OH RIVER VALLEY WILL MOVE EAST TO
THE MID ATLANTIC COAST THROUGH THE EVENING. WEAK UPPER LEVEL
RIDGING WILL ALSO BUILD ACROSS THE SOUTHEASTERN STATES. WE WILL
SEE PARTLY TO MOSTLY SUNNY SKIES TODAY WITH HIGHS IN THE MID 60S
NORTH TO AROUND 70 SOUTH. MORE CLOUDINESS IS EXPECTED TONIGHT AS
THE UPPER LEVEL RIDGE MOVES OFF THE EAST COAST AND A WARM FRONT
CROSSES THE AREA FROM THE SOUTH. INCREASING CLOUDS WILL HELP TO
HOLD TEMPERATURES UP OVERNIGHT...WITH LOWS IN THE MID 40S TO LOWER
50S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AN UPSTREAM UPPER LEVEL CUTOFF LOW CURRENTLY OVER NEW MEXICO WILL
SLOWLY PUSH EASTWARD ACROSS THE SOUTHERN PART OF THE COUNTRY
THURSDAY...THEN OPEN UP AND LIFT ACROSS THE SOUTHEASTERN STATES
FRIDAY.
WEAK ISENTROPIC LIFTING DEVELOPS IN WARM ADVECTION DURING THE DAY
THURSDAY. KEPT A MENTION OF SLIGHT CHANCE POPS FOR THURSDAY...MAINLY
ACROSS THE WESTERN HALF OF THE FORECAST AREA.
THE ECMWF IS THE MOST PROGRESSIVE WITH THE NAM BEING SLIGHTLY LOWER
AND THE GFS BEING THE SLOWEST OF ALL GUIDANCE. DISCOUNTED THE GFS
SOLUTION AT THIS TIME GIVEN ITS LARGE CHANGE FROM PREVIOUS RUNS
AND AS IT IS AN OUTLIER AMONG ALL GUIDANCE AND LEANING TOWARDS THE
NAM TIMING. KEPT INCREASING POPS THURSDAY NIGHT WITH CATEGORICAL
POPS EARLY FRIDAY...AND DIMINISHING POPS ON FRIDAY AFTERNOON.
THUNDER IS POSSIBLE GIVEN MARGINAL INSTABILITY. RAINFALL AMOUNTS
ARE EXPECTED TO RANGE BETWEEN 0.25 AND 0.50 INCH.
TEMPERATURES ON THURSDAY WILL BE WELL ABOVE NORMAL WITH HIGHS IN THE
70S AND OVERNIGHT LOWS IN THE UPPER 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE EXTENDED FORECAST FEATURES DRY WEATHER WITH NEAR TO SLIGHTLY
BELOW NORMAL TEMPERATURES OVER THE WEEKEND...FOLLOWED BY A WEAK
WARMING TREND ON TUESDAY.
ANOTHER UPPER TROUGH AND ACCOMPANYING SURFACE COLD FRONT WILL PUSH
THROUGH THE OH/TN VALLEYS ON SATURDAY AND SHIFT OFF THE COAST BY
SUNDAY. THERE WILL BE LITTLE MOISTURE AVAILABLE FOR THE QUICK
MOVING TROUGH TO WORK WITH AS PRECIPITABLE WATER VALUES WILL BE
AROUND A HALF INCH SATURDAY AND FALL BELOW A QUARTER INCH ON SUNDAY.
A QUICK REINFORCING SHOT OF COLD AIR WILL ARRIVE FOR SUNDAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE AS THE UPPER TROUGH AXIS PASSES
OVERHEAD.
TEMPERATURES ON SATURDAY WILL RANGE FROM THE UPPER 50S NORTHERN
MIDLANDS TO LOWER 60S IN THE EASTERN MIDLANDS AND CSRA. SATURDAY
NIGHT UNDER COLD ADVECTION OVERNIGHT LOWS WILL FALL INTO THE LOWER
AND MID 30S AS HIGH PRESSURE BUILDS INTO THE REGION. SUNDAY LOOKS
TO BE THE COLDEST DAY DESPITE PLENTY OF SUNSHINE WITH HIGHS SLIGHTLY
BELOW NORMAL IN THE 50S AND A COLD NIGHT IS EXPECTED SUNDAY NIGHT
WITH HIGH PRESSURE CENTERED OVER THE FORECAST AREA. SUNDAY NIGHT
LOWS SHOULD FALL INTO THE 20S.
EARLY NEXT WEEK THE MID LEVEL FLOW BECOMES MORE ZONAL AND A
DAMPENING TROUGH MOVING THROUGH THE FLOW WILL PASS OVER THE AREA ON
TUESDAY. WILL KEEP A DRY FORECAST AT THIS TIME GIVEN UNCERTAINTY ON
DAY 7...BUT TEMPERATURES WILL REBOUND AND WARM AS SOUTHERLY FLOW
RETURNS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
INITIAL SHORT WAVE DEPICTED IN THE VORTICITY FIELD OVER GEORGIA WILL
CROSS THE REGION THIS MORNING. HIGH PRESSURE WILL RETREAT
NORTHEAST AHEAD OF IT ALLOWING A FLOW OF MORE MOIST AIR FROM THE
SOUTHWEST TO FLOW ACROSS THE AREA BEHIND THE SHORT WAVE. PATCHY
LOW STRATUS AND FOG SHOULD DISSIPATE EARLY THIS MORNING WITH VFR
CONDITIONS RETURNING...BUT AS THAT SHORTWAVE MOVES NORTHEAST OF THE
AREA...CLOUDINESS WILL INCREASE DURING THE DAY AND CEILINGS WILL
LOWER AGAIN AS THE MOISTURE BUILDS INTO THE LOWER LEVELS. ALL
MODEL GUIDANCE IS SIMILAR IN INCREASING CLOUDINESS AND DROPPING
THE CEILINGS AND VISIBILITY LATER TONIGHT. IFR CONDITIONS ARE
POSSIBLE ACROSS THE AREA BY THURSDAY MORNING...BUT CONFIDENCE IS
TOO LOW TO INCLUDE IT IN THE TERMINAL FORECASTS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...IFR CONDITIONS ARE POSSIBLE FROM THURSDAY
MORNING THROUGH FRIDAY MORNING AS A STORM SYSTEM CURRENTLY OVER
NORTHERN MEXICO MOVES TOWARD THE AREA.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
632 AM EST WED JAN 25 2012
.SYNOPSIS...
HIGH PRESSURE OVER THE AREA TODAY WILL MOVE OFF THE COAST TONIGHT.
A LOW PRESSURE SYSTEM WILL AFFECT THE AREA THURSDAY INTO FRIDAY.
DRY HIGH PRESSURE WILL TAKE CONTROL FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LINGERING LOW LEVEL MOISTURE HAS ALLOWED AREAS OF FOG TO DEVELOP
ACROSS THE MIDLANDS EARLY THIS MORNING. IT APPEARS THE LARGEST
AREA IS AFFECTING THE NORTH MIDLANDS. THE RUC AND NAM20 MODELS
INDICATE THE LOW LEVEL MOISTURE TO LINGER THROUGH THE 12Z-14Z
TIME-FRAME. HOWEVER..BOTH MODELS SHOW A LOW LEVEL JET WHICH PROMOTE
MIXING. SO...NOT WE ARE NOT EXPECTING THE FOG TO BE AS
WIDESPREAD AS TUESDAY MORNING. WILL CONTINUE THE DENSE FOG
ADVISORY FOR LANCASTER AND CHESTERFIELD COUNTIES THROUGH 7 AM...
AND ADD AREAS OF FOG TO OTHER SECTIONS OF THE MIDLANDS. THE FOG
HIGH PRESSURE CENTERED OVER THE OH RIVER VALLEY WILL MOVE EAST TO
THE MID ATLANTIC COAST THROUGH THE EVENING. WEAK UPPER LEVEL
RIDGING WILL ALSO BUILD ACROSS THE SOUTHEASTERN STATES. WE WILL
SEE PARTLY TO MOSTLY SUNNY SKIES TODAY WITH HIGHS IN THE MID 60S
NORTH TO AROUND 70 SOUTH. MORE CLOUDINESS IS EXPECTED TONIGHT AS
THE UPPER LEVEL RIDGE MOVES OFF THE EAST COAST AND A SOUTHWEST
FLOW ALOFT BRINGS IN MORE MOISTURE. CLOUDS WILL HELP TO HOLD
TEMPERATURES UP OVERNIGHT...WITH LOWS IN THE MID 40S TO LOWER 50S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AN UPSTREAM UPPER LEVEL CUTOFF LOW CURRENTLY OVER NEW MEXICO WILL
SLOWLY PUSH EASTWARD ACROSS THE SOUTHERN PART OF THE COUNTRY
THURSDAY...THEN OPEN UP AND LIFT ACROSS THE SOUTHEASTERN STATES
FRIDAY.
WEAK ISENTROPIC LIFTING DEVELOPS IN WARM ADVECTION DURING THE DAY
THURSDAY. KEPT A MENTION OF SLIGHT CHANCE POPS FOR THURSDAY...MAINLY
ACROSS THE WESTERN HALF OF THE FORECAST AREA.
THE ECMWF IS THE MOST PROGRESSIVE WITH THE NAM BEING A BIT SLOWER
AND THE GFS BEING THE SLOWEST OF ALL GUIDANCE. DISCOUNTED THE GFS
SOLUTION AT THIS TIME GIVEN ITS LARGE CHANGE FROM PREVIOUS RUNS
AND AS IT IS AN OUTLIER AMONG ALL GUIDANCE AND LEANING TOWARDS THE
NAM TIMING. KEPT INCREASING POPS THURSDAY NIGHT WITH CATEGORICAL
POPS EARLY FRIDAY...AND DIMINISHING POPS ON FRIDAY AFTERNOON.
THUNDER IS POSSIBLE GIVEN MARGINAL INSTABILITY.
TEMPERATURES ON THURSDAY WILL BE WELL ABOVE NORMAL WITH HIGHS IN THE
70S AND OVERNIGHT LOWS IN THE UPPER 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE EXTENDED FORECAST FEATURES DRY WEATHER WITH NEAR TO SLIGHTLY
BELOW NORMAL TEMPERATURES OVER THE WEEKEND...FOLLOWED BY A WEAK
WARMING TREND ON TUESDAY.
ANOTHER UPPER TROUGH AND ACCOMPANYING SURFACE COLD FRONT WILL PUSH
THROUGH THE OH/TN VALLEYS ON SATURDAY AND SHIFT OFF THE COAST BY
SUNDAY. THERE WILL BE LITTLE MOISTURE AVAILABLE FOR THE QUICK
MOVING TROUGH TO WORK WITH AS PRECIPITABLE WATER VALUES WILL BE
AROUND A HALF INCH SATURDAY AND FALL BELOW A QUARTER INCH ON SUNDAY.
A QUICK REINFORCING SHOT OF COLD AIR WILL ARRIVE FOR SUNDAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE AS THE UPPER TROUGH AXIS PASSES
OVERHEAD.
TEMPERATURES ON SATURDAY WILL RANGE FROM THE UPPER 50S NORTHERN
MIDLANDS TO LOWER 60S IN THE EASTERN MIDLANDS AND CSRA. SATURDAY
NIGHT UNDER COLD ADVECTION OVERNIGHT LOWS WILL FALL INTO THE LOWER
AND MID 30S AS HIGH PRESSURE BUILDS INTO THE REGION. SUNDAY LOOKS
TO BE THE COLDEST DAY DESPITE PLENTY OF SUNSHINE WITH HIGHS SLIGHTLY
BELOW NORMAL IN THE 50S AND A COLD NIGHT IS EXPECTED SUNDAY NIGHT
WITH HIGH PRESSURE CENTERED OVER THE FORECAST AREA. SUNDAY NIGHT
LOWS SHOULD FALL INTO THE 20S.
EARLY NEXT WEEK THE MID LEVEL FLOW BECOMES MORE ZONAL AND A
DAMPENING TROUGH MOVING THROUGH THE FLOW WILL PASS OVER THE AREA ON
TUESDAY. WILL KEEP A DRY FORECAST AT THIS TIME GIVEN UNCERTAINTY ON
DAY 7...BUT TEMPERATURES WILL REBOUND AND WARM AS SOUTHERLY FLOW
RETURNS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
INITIAL SHORT WAVE DEPICTED IN THE VORTICITY FIELD OVER GEORGIA WILL
CROSS THE REGION THIS MORNING. HIGH PRESSURE WILL RETREAT
NORTHEAST AHEAD OF IT ALLOWING A FLOW OF MORE MOIST AIR FROM THE
SOUTHWEST TO FLOW ACROSS THE AREA BEHIND THE SHORT WAVE. PATCHY
LOW STRATUS AND FOG SHOULD DISSIPATE EARLY THIS MORNING WITH VFR
CONDITIONS RETURNING...BUT AS THAT SHORTWAVE MOVES NORTHEAST OF THE
AREA...CLOUDINESS WILL INCREASE DURING THE DAY AND CEILINGS WILL
LOWER AGAIN AS THE MOISTURE BUILDS INTO THE LOWER LEVELS. ALL
MODEL GUIDANCE IS SIMILAR IN INCREASING CLOUDINESS AND DROPPING
THE CEILINGS AND VISIBILITY LATER TONIGHT. IFR CONDITIONS ARE
POSSIBLE ACROSS THE AREA BY THURSDAY MORNING...BUT CONFIDENCE IS
TOO LOW TO INCLUDE IT IN THE TERMINAL FORECASTS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...IFR CONDITIONS ARE POSSIBLE FROM THURSDAY
MORNING THROUGH FRIDAY MORNING AS A STORM SYSTEM CURRENTLY OVER
NORTHERN MEXICO MOVES TOWARD THE AREA.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
536 AM CST WED JAN 25 2012
.UPDATE...
.AVIATION..../FOR THE 12Z TAF ISSUANCE/
INFRARED SATELLITE IMAGERY AND REGIONAL METAR OBSERVATIONS INDICATE
MAINLY CLEAR SKY CONDITIONS PREVAILING ACROSS THE FORECAST AREA
(INCLUDING HYS,DDC AND GCK) THIS MORNING. THIS IS A RESULT OF AN
EASTWARD EXITING MID LEVEL WAVE FROM THE SOUTHERN PLAINS AND
INCREASING HIGH PRESSURE AT THE SURFACE FROM THE HIGH PLAINS OF
COLORADO. THE DRY WEAK NORTHWEST SURFACE FLOW PATTERN IS EXPECTED TO
PERSIST THROUGH THIS TAF PERIOD. A SLIGHT INCREASE IN WIND SPEEDS TO
ABOVE 12 KNOTS IS EXPECTED BY AROUND 09 UTC THURSDAY AS MOMENTUM
TRANSFER INCREASES SLIGHTLY FROM INCREASED DEEP LAYER FLOW OVER THE
NORTHERN HIGH PLAINS. THIS IS SUPPORTED BY MUCH OF THE VARIOUS MODEL
OUTPUT AND LOCAL GFS MOS GUIDANCE.
&&
.PREV DISCUSSION... /ISSUED 251 AM CST WED JAN 25 2012/
DISCUSSION...
SHORT TERM...
AT 00Z WEDNESDAY A 500MB UPPER LOW WAS LOCATED NEAR EL PASO
TEXAS. NORTH OF THIS UPPER LOW A 700MB BAROCLINIC ZONE EXTENDED
ACROSS EASTERN COLORADO. AS OF 6Z THE RUC AND NAM INDICATED THAT THIS
700MB BAROCLINIC WAS CURRENTLY MOVING EAST ACROSS WESTERN KANSAS
WITH SATELLITE LOOP INDICATING WARMING CLOUD TOPS AS THIS
BAROCLINIC ZONE PASSES. CLEAR SKIES HAD ALREADY DEVELOPED WEST OF
THE 500MB DEFORMATION ZONE WHICH AT 06Z WAS STARTING TO CROSS INTO
WESTERN KANSAS. THE LIGHT PRECIPITATION THAT HAD DEVELOPED OVER
PORTIONS OF SOUTH CENTRAL KANSAS EARLIER TONIGHT WILL SLOWLY SHIFT
SOUTHEAST THROUGH THE REMAINDER OF THE MORNING AS THE MID LEVEL
BAROCLINIC ZONE CROSSES INTO SOUTH CENTRAL KANSAS BETWEEN 09Z AND 12Z
WEDNESDAY. CLOUD COVER WILL ALSO GRADUALLY GIVE WAY TO CLEAR SKIES
BY MID DAY IN THE SOUTHEAST AS THE 500MB DEFORMATION EXITS THE
AREA BASED ON 00Z NAM AND 06Z RUC.
THE NAM AND GFS MODEL SOUNDINGS AT 00Z THURSDAY, AS WELL AS ECMWF
6HOUR MAX TEMPERATURE FORECAST WERE ALL SUGGESTING THAT HIGHS
TODAY WILL REBOUND BACK INTO THE LOWER 50S ACROSS WESTERN KANSAS.
IN THE EAST WHERE CLOUDS WILL BE SLOWER TO ERODE THE HIGHS ARE
EXPECTED TO CLIMB TO AROUND 50 BUT IF SKIES CLEAR SOONER IT COULD
BE SEVERAL DEGREES WARMER BASED ON THE 875MB MIX DOWN TEMPERATURE.
TONIGHT A WEAK FRONT WILL MOVE INTO WESTERN KANSAS AS AN UPPER
LEVEL SHORT WAVE TROUGH WHICH WAS ASSOCIATED WITH THE LEFT EXIT
REGION OF A 250MB JET STREAK THAT LOCATED ACROSS WASHINGTON STATE
AT 00Z WEDNESDAY QUICKLY CROSSES THE NORTHERN PLAINS. THE
925-850MB 24HR TEMPERATURE CHANGE FROM 00Z THURSDAY TO 00Z FRIDAY
WAS ONLY A FEW DEGREES OF EACH OTHER SO GIVEN LIMITED CLOUD COVER
EXPECTED THURSDAY AFTERNOON WILL FAVOR HIGHS VERY SIMILAR THOSE
TODAY IN THE WEST. EAST/SOUTHEAST OF DODGE CITY HOWEVER GIVEN MORE
SUN AND BETTER MIXING POTENTIAL THE HIGH SHOULD BE A LITTLE WARMER
BASED ON THE FORECAST 00Z FRIDAY MODEL SOUNDINGS.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
FRIDAY WILL BE BREEZY AT LEAST AND PROBABLY WINDY AS A COLD FRONT
SWEEPS THROUGH THE AREA IN THE MORNING. NORTHWEST FLOW ALOFT WILL BE
INCREASING WITH TIME AS WELL AS THE UPPER JET FROM THE WEST COAST
RIDGE MOVES INTO THE CENTRAL HIGH PLAINS. THE FAST MOVING FRONT
SHOULD BRING A COOLER AIRMASS SOUTHWARD ALONG WITH WEAK FRONTOGENESIS
BUT THE MOISTURE APPEARS RATHER LIMITED. THE BEST QPF FIELDS IN THE
NUMERICAL MODELS LOOK TO BE BETTER ASSOCIATED WITH THE UPPER JET`S
LEFT FRONT EXIT REGION ACROSS THE MISSOURI VALLEY, AND THE BETTER
UPSLOPE FLOW/HIGHER TERRAIN OF EASTERN COLORADO. THEREFORE WE ARE
NOT IMPRESSED WITH PRECIPITATION CHANCES, AND WILL LEAVE THE 20
PERCENT CHANCES FOR RAIN OF FRIDAY ACROSS PORTIONS OF THE FORECAST
AREA. SURFACE HIGH PRESSURE SHOULD THEN DRIFT INTO NORTHERN TEXAS
AND OKLAHOMA ON SATURDAY , WHICH WOULD PRODUCE A LIGHT WESTERLY WIND
FIELD OVER SOUTHWEST KANSAS, AND SIMILAR TEMPERATURES ON BOTH DAYS
IN THE 40S. DUE TO THE LACK OF MOISTURE, THERE DOESN`T APPEAR TO BE
SIGNIFICANT CLOUD COVER DURING THIS PERIOD, BUT WITH THE UPPER JET
BUCKLED ACROSS THE PLAINS, SOME CS MIGHT BE EXPECTED. OVERNIGHT
TEMPERATURES WILL EASILY FALL BELOW FREEZING GIVEN THE COLD 850 MB
TEMPERATURE FIELDS AND THE RELATIVELY LIGHT WINDS. THE SYNOPTIC
PATTERN WILL CHANGE HEADING INTO THE LATER PART OF THE WEEKEND AS
THE UPPER WEST COAST RIDGE PUSHES FARTHER EAST AND THE LEAD UPPER
JET DIVES INTO THE MISSOURI VALLEY. THAT WILL DRAW WARMER AIR FROM
THE HIGHER TERRAIN OF NEW MEXICO AND COLORADO SUNDAY NIGHT AND INTO
MONDAY AND ALLOW TEMPERATURES TO WARM BY ABOUT 10-20 DEGREES DURING
THE DAYTIME HEADING INTO MONDAY AFTERNOON AND ESPECIALLY TUESDAY.
BOTH MODELS PRODUCE A SHORTWAVE TROUGH MOVING THROUGH THE AREA ON
MONDAY, IN A DRY AND STABLE ATMOSPHERE WHICH WILL MAINLY BRING ABOUT
A SURFACE WIND SHIFT DURING THE DAY FROM SOUTHEAST TO NORTHWEST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 52 27 52 28 / 0 0 0 0
GCK 52 26 51 28 / 0 0 0 0
EHA 52 31 51 29 / 0 0 0 0
LBL 53 28 53 27 / 0 0 0 0
HYS 50 26 52 28 / 0 0 0 10
P28 51 30 55 28 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN99/99
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
958 AM EST WED JAN 25 2012
.SYNOPSIS...
HIGH PRESSURE WILL BRING QUIET WEATHER TODAY AS CLOUDS SLOWLY
DECREASE. A STORM SYSTEM WILL MOVE NORTHEAST FROM THE GULF COAST
FOR WEDNESDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
WITH 10AM UPDATE...HAVE PRIMARILY TWEAKED SKY AND TEMPERATURE
TRENDS. HAVE NOTICED THAT RECENT RUNS OF THE HRRR KEEP OVERCAST
SKIES ALL DAYS...WHICH WOULD RESULT IN LOWER HIGH TEMPERATURES
ACROSS THE REGION. IF THIS OCCURS...THERE WOULD BE A GREATER
CHANCE FOR FREEZING RAIN LATE TONIGHT. PREVIOUS DISCUSSION
FOLLOWS.
AREA OF LOW CLOUDS WILL REMAIN ACROSS REGION THROUGH THE MORNING
BUT SHOULD BEGIN TO MIX OUT MIDDAY. THESE WILL BE REPLACED BY MID
DECK LATER THIS AFTERNOON AS HIGH LEVEL MOISTURE AHEAD OF GULF
COAST SYSTEM STREAM NORTH.
TONIGHT STORM SYSTEM WILL MOVE FROM TEXAS TOWARD THE OHIO VALLEY
WHILE NORTHERN STREAM SHORTWAVE AND FRONT SLIDE NORTH OF REGION.
USED A GENERAL BLEND OF ECMWF AND NAM MODELS. APPEARS THERE WILL
BE ENOUGH COLD AIR IN PLACE FOR A POSSIBLE MIX OF FREEZING RAIN
FROM PITTSBURGH NORTH AND IN THE RIDGES AS PRECIP BEGINS. SOME
SLEET ALSO POSSIBLE I-80 CORRIDOR. STILL DOUBT ON ARRIVAL TIME OF
PRECIP, AND QPF OVERNIGHT WILL BE ON THE LIGHT SIDE. IF ARRIVAL OF
PRECIP DELAYED AS PER GFS MODEL LITTLE IF ANY FREEZING OR FROZEN
PRECIP WILL OCCUR. WILL MENTION IN HWO THAT A BRIEF PERIOD OF
FREEZING RAIN POSSIBLE OVERNIGHT. NOT ENOUGH CONFIDENCE IN ANY
SOLUTION FOR ANY HEADLINES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS LOW PRESSURE PUSHES NORTHEAST DURING THE DAY THURSDAY WARM
ADVECTION WILL WARM TEMPERATURES INTO THE 40S WITH RAIN
OVERSPREADING THE AREA AND CONTINUING INTO THURSDAY NIGHT. MODELS
STILL HAVE DIFFERENCES IN PLACEMENT OF HIGHEST QPF BUT BELIEVE A
HALF TO ONE INCH RAINFALL LIKELY SOUTHERN 2/3RDS OF CWA. WENT WITH
A CHANGEOVER TO SNOW AS PRECIP DIMINISHES LATER THURSDAY NIGHT BUT
LITTLE IF ANY ACCUMULATION EXPECTED AS DEEP MOISTURE WILL BE
EXITING BEFORE COLDER THICKNESS CAN ARRIVE. KEPT POPS IN FOR
FRIDAY WITH LEFTOVER MOISTURE IN WEST TO NORTHWEST FLOW BEHIND
SURFACE LOW.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
BLEND OF ECMWF AND NAEFS MODEL OUTPUT SHOW PACIFIC COAST RIDGING IN
THE UPPER LEVEL JETSTREAM CAUSING TROUGHING ACROSS THE CANADIAN
PLAINS THIS WEEKEND. SO EXPECT UPPER OHIO VALLEY TEMPERATURES TO GO
COLDER THAN NORMAL SUNDAY IN THE WAKE OF THE PLAINS-BRED COLD
FRONTAL PASSAGE SATURDAY. SO THE COLD FRONTAL PASSAGE SATURDAY WILL
BE ACCOMPANIED BY BOTH RAIN AND SNOW SHOWERS, BUT THEN FOLLOWED BY
SCATTERED SNOW SHOWERS SUNDAY.
EARLY NEXT WEEK, THE MODELS SHOW THE SOUTHERN JETSTREAM BRANCH
GAINING MORE INFLUENCE, AND THIS IS REFLECTED IN UPPER OHIO VALLEY
TEMPERATURES MODERATING TUESDAY AHEAD OF AN INCOMING OKLAHOMA-BRED
LOW PRESSURE SYSTEM. HENCE THE SYSTEM`S WARM FRONTAL PASSAGE TUESDAY
MAY BE ACCOMPANIED BY MIXED PRECIPITATION.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
MVFR STRATOCUMULUS CLOUDS WILL CONTINUE TO PREVAIL ACROSS THE
TERMINALS THROUGH THE EARLY AFTERNOON HOURS. SREF/LAMP GUIDANCE
SUPPORT MVFR CLOUDS ERODING FROM THE SOUTH AFTER 18Z AND REACHING
KFKL AND KDUJ BY 21Z. HIGH CIRRUS WILL THEN FILTER ACROSS THE
TERMINALS WITH VFR CONDITIONS PREVAILING EARLY TONIGHT.
CEILINGS WILL RETURN AND LOWER TO MVFR AFTER 06Z THURSDAY AS SHOWERS
PUSH INTO THE TERMINALS WELL AHEAD OF A FRONTAL BOUNDARY ACROSS THE
TENNESSEE VALLEY. FORECAST CONSISTS OF ALL RAIN AT THIS POINT,
ALTHOUGH THERE IS LOW CONFIDENCE THAT A BRIEF PERIOD OF FREEZING
RAIN WILL BE POSSIBLE NEAR DAWN, ESPECIALLY NORTH OF A KAGC-KLBE
LINE.
WINDS WILL GENERALLY REMAIN LIGHT...TO ABOUT 5-8KTS UNDER HIGH
PRESSURE...GRADUALLY BECOMING EASTERLY AT THE SURFACE.
OUTLOOK...THURSDAY THROUGH SUNDAY...
RAIN SHOWERS WILL CROSS THE REGION OUT AHEAD OF THE APPROACHING
UPPER LEVEL TROUGH AND ASSOCIATED SURFACE LOW ON THURSDAY. MIXED
PRECIPITATION AND WIDESPREAD RESTRICTIONS ARE EXPECTED FOR THURSDAY
NIGHT AND FRIDAY AS THAT TROUGH MOVES E/NEWD. MORE RESTRICTIONS ARE
POSSIBLE FOR THE WEEKEND AS THE SYSTEMS COLD FRONT GENERATES SHRA
AND SHSN.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1033 AM EST WED JAN 25 2012
.SYNOPSIS...
LINGERING LIGHT SNOW SHOWERS AND FLURRIES WILL END ACROSS THE
NORTHERN MOUNTAINS LATE TODAY AS CLOUDS SLOWLY THIN OVER TIME AND
WEAK HIGH PRESSURE BUILDS INTO THE REGION. EXPECT GENERALLY FAIR
AND DRY WEATHER TONIGHT INTO THURSDAY...BEFORE MIXED PRECIPITATION
ARRIVES THURSDAY NIGHT INTO FRIDAY MORNING. TEMPERATURES WILL COOL
TO NEAR SEASONAL LATE JANUARY NORMALS TODAY INTO THURSDAY...THEN
TREND ABOVE NORMAL BY FRIDAY INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1032 AM EST WEDNESDAY...VISIBLE SATELLITE LOOP SHOWING LOW
CLOUD COVER HANGING IN ACROSS THE REGION THIS MORNING. 12Z ALBANY
RAOB SOUNDING SHOWING THIS LOW LEVEL MOISTURE IN THE 1000-850 MB
LAYER. THIS SOUNDING ALSO SHOWS A STRONG TEMPERATURE INVERSION
ABOVE THIS LAYER...SO EXPECTING CLOUD COVER TO HANG IN THROUGH THE
REMAINDER OF TODAY. HAVE LOWERED POPS FOR THE REMAINDER OF
TODAY...BUT HAVE KEPT IN A MENTION OF SNOW FLURRIES ACROSS THE
ADIRONDACKS AND THE GREEN MOUNTAINS AND NORTHEAST VERMONT. MAX
TEMPERATURES HAVE OCCURRED EARLIER TODAY...SO EXPECTING
TEMPERATURES TO REMAIN NEARLY STEADY OR FALL SLIGHT THROUGH THE
REST OF TODAY.
AS OF 628 AM EST WEDNESDAY...MINOR UPDATE TO MATCH CURRENT T/TD
OBSERVATIONAL DATA AND BLEND INTO LATEST LAMP DATA THIS AFTERNOON.
ALSO OPTED TO KEEP CLOUD COVER IN A LITTLE LONGER TODAY PER
STRONGER INVERSION EVIDENT OFF 10Z RUC SOUNDING PROGS. HIGHS
SHOULD OCCUR THIS MORNING AS MID LVL TEMPS CONTINUE TO COOL
TODAY...BUT NOT A SHARP DROP EXPECTED...JUST A GRADUAL COOL DOWN
OF 3-6 DEG OVER THE COURSE OF THE DAY IN MOST AREAS. REST OF
FORECAST UNCHANGED.
PRIOR DISCUSSION...
GENERALLY QUIET WEATHER ON TAP TODAY
UNDER MODEST WEST TO NORTHWEST FLOW ON THE BACK SIDE OF DEPARTING
UPPER TROUGH. ANY LINGERING LIGHT SHSN/FLURRIES TO END ACROSS THE
NORTHERN MOUNTAINS BY THIS AFTERNOON AS CLOUDS THIN BY LATE
AFTERNOON/EARLY EVENING AND WEAK HIGH PRESSURE BUILDS EAST.
MODEST CAA IN THE LOWER LEVELS AND ABUNDANT CLOUD COVER THROUGH
MUCH OF THE DAY SHOULD KEEP TEMPERATURES FAIRLY STEADY THROUGH
LATE AFTERNOON...GENERALLY IN THE 20S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
AS OF 215 AM EST WEDNESDAY...THEN CLEAR TO PTLY CLOUDY SKIES
THROUGH THE NIGHTTIME HOURS ALONG WITH LIGHT WINDS AS BROAD AND
ELONGATED HIGH PRESSURE FROM THE GREAT LAKES INTO THE MID
ATLANTIC REGION APPROACHES. DECENT RADIATIONAL COOLING NIGHT ON
TAP...BUT WITH GENERAL LACK OF SNOW AND/OR FRESH SNOW COVER IN
MOST AREAS ONLY NEAR SEASONAL LOWS EXPECTED IN THE 5 TO 15 DEGREE
RANGE TO NEAR 20 SOUTH.
SFC HIGH TO THEN BUILD ATOP AND EAST OF THE REGION DURING
THURSDAY AS FLOW TRENDS TO LIGHT EAST/SOUTHEASTERLY BY DAYS END.
DRY WEATHER IS EXPECTED THOUGH A BROAD INCREASE IN MID TO UPPER
LEVEL CLOUD COVER WILL OCCUR FROM THE SOUTHWEST LATER IN THE DAY
AS WAA ALOFT SPREADS NORTHEAST IN ADVANCE OF APPROACHING SOUTHERN
STREAM SHORTWAVE. 925 HPA THERMAL PROFILES FROM THIS MORNING`S
NEAR TERM GUIDANCE SUPPORTS MOS HIGHS IN THE LOWER TO MID 30S
AREA WIDE WITH CUSTOMARY ADJUSTMENTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 330 AM EST WEDNESDAY...SOME DIFFERENCES REMAIN BETWEEN THE
GFS AND ECMWF FROM THURSDAY NIGHT ONWARD. LOW PRESSURE SYSTEM
APPROACHES FROM OHIO VALLEY REGION ON THURSDAY NIGHT...SPREADING
PRECIP ACROSS OUR FORECAST AREA FROM SOUTH TO NORTH. ECMWF IS A
BIT FASTER WITH THIS SYSTEM BY ABOUT 6 HOURS. THEN GFS KEEPS LOW
TRACKING NORTHEAST AND OFF THE COAST OF NEW ENGLAND. ECMWF BRINGS
THE SYSTEM INLAND AND CUTS THROUGH NEW ENGLAND. PLACEMENT OF LOW
WILL DETERMINE AMOUNT AND TYPE OF PRECIP...THEREFORE STILL SOME
UNCERTAINTY WITH REGARDS TO THIS PART OF THE FORECAST. AT THIS
TIME MAINLY HAVE MENTIONED SLEET AND SNOW. LOW WILL PASS EAST ON
FRIDAY AND PRECIP CHANGES OVER TO UPSLOPE SNOW SHOWERS FRIDAY
NIGHT AND ENDS BY EARLY SATURDAY MORNING. WEATHER WILL REMAIN
FAIRLY QUIET AFTER THIS SYSTEM DEPARTS...BUT WITH A SLOW MOVING
LOW PRESSURE SYSTEM TO OUR NORTH HAVE MENTION OF CHANCE SNOW
SHOWERS FROM LATE SATURDAY NIGHT THROUGH MONDAY EVENING. DRY
WEATHER THEN RETURNS THROUGH THE END OF THE PERIOD. ABOVE NORMAL
TEMPERATURES...WITH A COUPLE PERIODS NEAR NORMAL...CONTINUES
THROUGH THE EXTENDED.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...BKN/OVC MAINLY VFR CIGS EXPECTED THROUGH 18Z
UNDER MODEST AND OCCNLY GUSTY WEST/NORTHWESTERLY WINDS. EXCEPTION
WILL BE LINGERING MVFR CIGS AND PERHAPS A STRAY FLURRY AT
KSLK/KMPV THROUGH 16Z OR SO. AFTER 18Z...VFR EXPECTED AT ALL
TERMINALS UNDER SLOWLY ABATING WINDS. SOME BKN MID LEVEL CLOUD
COVER FROM FL120-200 POSSIBLE FROM 18-22Z AND ONWARD INTO THE
OVERNIGHT HOURS.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...
12Z THURSDAY THROUGH 00Z FRIDAY...VFR WITH WEAK HIGH PRESSURE.
BKN/OVC MID TO HIGH LVL CIGS POSSIBLE AFTER 18Z.
00Z FRIDAY THROUGH 18Z FRIDAY...MVFR/IFC IN LIGHT SNOW/MIXED PCPN
WITH LOW PRESSURE PASSING SOUTH OF REGION.
18Z FRIDAY THROUGH 12Z SUNDAY...MAINLY VFR WITH WEAK HIGH
PRESSURE.
12Z SUNDAY ONWARD...MVFR/OCCNLY IFR IN SHSN WITH FRONTAL PASSAGE.
&&
.EQUIPMENT...
AS OF 1032 AM EST WEDNESDAY...THE TEMPERATURE AND DEW POINT
SENSORS ARE OUT OF SERVICE AT THIS TIME AT THE AUTOMATED SURFACE
WEATHER OBSERVING SYSTEM (ASOS) AT MASSENA INTERNATIONAL
AIRPORT/RICHARDS FIELD (KMSS) IN MASSENA NEW YORK. PARTS ARE ON
BACK ORDER TO REPAIR THESE SENSORS. PER OUR ELECTRONICS
TECHNICIAN...THESE SENSORS MAY POTENTIALLY BE OUT OF SERVICE FOR
SEVERAL DAYS...UNTIL REPLACEMENT PARTS ARRIVE.
ALSO...ON THURSDAY...JANUARY 26TH...NOAA WEATHER RADIO STATION KIG60
...ATOP OF MOUNT MANSFIELD IN NORTHWEST VERMONT...OPERATING ON A
FREQUENCY OF 162.400 MEGAHERTZ...WILL BE PERIODICALLY OFF THE AIR
OR EXPERIENCING DEGRADATION IN AUDIO QUALITY DUE TO MAINTENANCE.
THE MAINTENANCE IS TO REPLACE AN OLD NOAA WEATHER RADIO
TRANSMITTER WITH A NEW TRANSMITTER THAT SHOULD IMPROVE BROADCAST
QUALITY FOR THOSE THAT RELY ON NOAA WEATHER RADIO FOR WEATHER
FORECASTS AND LIFE-SAVING WARNINGS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/WGH
SHORT TERM...JMG
LONG TERM...NEILES
AVIATION...JMG
EQUIPMENT...WGH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
628 AM EST WED JAN 25 2012
.SYNOPSIS...
LINGERING LIGHT SNOW SHOWERS AND FLURRIES WILL END ACROSS THE
NORTHERN MOUNTAINS TODAY AS CLOUDS SLOWLY THIN OVER TIME AND WEAK
HIGH PRESSURE BUILDS INTO THE REGION. EXPECT GENERALLY FAIR AND
DRY WEATHER TONIGHT INTO THURSDAY...BEFORE MIXED PRECIPITATION
ARRIVES THURSDAY NIGHT INTO FRIDAY MORNING. TEMPERATURES WILL
COOL TO NEAR SEASONAL LATE JANUARY NORMALS TODAY INTO
THURSDAY...THEN TREND ABOVE NORMAL BY FRIDAY INTO THE UPCOMING
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 628 AM EST WEDNESDAY...MINOR UPDATE TO MATCH CURRENT T/TD
OBSERVATIONAL DATA AND BLEND INTO LATEST LAMP DATA THIS AFTERNOON.
ALSO OPTED TO KEEP CLOUD COVER IN A LITTLE LONGER TODAY PER
STRONGER INVERSION EVIDENT OFF 10Z RUC SOUNDING PROGS. HIGHS
SHOULD OCCUR THIS MORNING AS MID LVL TEMPS CONTINUE TO COOL
TODAY...BUT NOT A SHARP DROP EXPECTED...JUST A GRADUAL COOL DOWN
OF 3-6 DEG OVER THE COURSE OF THE DAY IN MOST AREAS. REST OF
FORECAST UNCHANGED.
PRIOR DISCUSSION...
GENERALLY QUIET WEATHER ON TAP TODAY
UNDER MODEST WEST TO NORTHWEST FLOW ON THE BACK SIDE OF DEPARTING
UPPER TROUGH. ANY LINGERING LIGHT SHSN/FLURRIES TO END ACROSS THE
NORTHERN MOUNTAINS BY THIS AFTERNOON AS CLOUDS THIN BY LATE
AFTERNOON/EARLY EVENING AND WEAK HIGH PRESSURE BUILDS EAST.
MODEST CAA IN THE LOWER LEVELS AND ABUNDANT CLOUD COVER THROUGH
MUCH OF THE DAY SHOULD KEEP TEMPERATURES FAIRLY STEADY THROUGH
LATE AFTERNOON...GENERALLY IN THE 20S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
AS OF 215 AM EST WEDNESDAY...THEN CLEAR TO PTLY CLOUDY SKIES
THROUGH THE NIGHTTIME HOURS ALONG WITH LIGHT WINDS AS BROAD AND
ELONGATED HIGH PRESSURE FROM THE GREAT LAKES INTO THE MID
ATLANTIC REGION APPROACHES. DECENT RADIATIONAL COOLING NIGHT ON
TAP...BUT WITH GENERAL LACK OF SNOW AND/OR FRESH SNOW COVER IN
MOST AREAS ONLY NEAR SEASONAL LOWS EXPECTED IN THE 5 TO 15 DEGREE
RANGE TO NEAR 20 SOUTH.
SFC HIGH TO THEN BUILD ATOP AND EAST OF THE REGION DURING
THURSDAY AS FLOW TRENDS TO LIGHT EAST/SOUTHEASTERLY BY DAYS END.
DRY WEATHER IS EXPECTED THOUGH A BROAD INCREASE IN MID TO UPPER
LEVEL CLOUD COVER WILL OCCUR FROM THE SOUTHWEST LATER IN THE DAY
AS WAA ALOFT SPREADS NORTHEAST IN ADVANCE OF APPROACHING SOUTHERN
STREAM SHORTWAVE. 925 HPA THERMAL PROFILES FROM THIS MORNING`S
NEAR TERM GUIDANCE SUPPORTS MOS HIGHS IN THE LOWER TO MID 30S
AREA WIDE WITH CUSTOMARY ADJUSTMENTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 330 AM EST WEDNESDAY...SOME DIFFERENCES REMAIN BETWEEN THE
GFS AND ECMWF FROM THURSDAY NIGHT ONWARD. LOW PRESSURE SYSTEM
APPROACHES FROM OHIO VALLEY REGION ON THURSDAY NIGHT...SPREADING
PRECIP ACROSS OUR FORECAST AREA FROM SOUTH TO NORTH. ECMWF IS A
BIT FASTER WITH THIS SYSTEM BY ABOUT 6 HOURS. THEN GFS KEEPS LOW
TRACKING NORTHEAST AND OFF THE COAST OF NEW ENGLAND. ECMWF BRINGS
THE SYSTEM INLAND AND CUTS THROUGH NEW ENGLAND. PLACEMENT OF LOW
WILL DETERMINE AMOUNT AND TYPE OF PRECIP...THEREFORE STILL SOME
UNCERTAINTY WITH REGARDS TO THIS PART OF THE FORECAST. AT THIS
TIME MAINLY HAVE MENTIONED SLEET AND SNOW. LOW WILL PASS EAST ON
FRIDAY AND PRECIP CHANGES OVER TO UPSLOPE SNOW SHOWERS FRIDAY
NIGHT AND ENDS BY EARLY SATURDAY MORNING. WEATHER WILL REMAIN
FAIRLY QUIET AFTER THIS SYSTEM DEPARTS...BUT WITH A SLOW MOVING
LOW PRESSURE SYSTEM TO OUR NORTH HAVE MENTION OF CHANCE SNOW
SHOWERS FROM LATE SATURDAY NIGHT THROUGH MONDAY EVENING. DRY
WEATHER THEN RETURNS THROUGH THE END OF THE PERIOD. ABOVE NORMAL
TEMPERATURES...WITH A COUPLE PERIODS NEAR NORMAL...CONTINUES
THROUGH THE EXTENDED.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...BKN/OVC MAINLY VFR CIGS EXPECTED THROUGH 18Z
UNDER MODEST AND OCCNLY GUSTY WEST/NORTHWESTERLY WINDS. EXCEPTION
WILL BE LINGERING MVFR CIGS AND PERHAPS A STRAY FLURRY AT
KSLK/KMPV THROUGH 16Z OR SO. AFTER 18Z...VFR EXPECTED AT ALL
TERMINALS UNDER SLOWLY ABATING WINDS. SOME BKN MID LEVEL CLOUD
COVER FROM FL120-200 POSSIBLE FROM 18-22Z AND ONWARD INTO THE
OVERNIGHT HOURS.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...
12Z THURSDAY THROUGH 00Z FRIDAY...VFR WITH WEAK HIGH PRESSURE.
BKN/OVC MID TO HIGH LVL CIGS POSSIBLE AFTER 18Z.
00Z FRIDAY THROUGH 18Z FRIDAY...MVFR/IFC IN LIGHT SNOW/MIXED PCPN
WITH LOW PRESSURE PASSING SOUTH OF REGION.
18Z FRIDAY THROUGH 12Z SUNDAY...MAINLY VFR WITH WEAK HIGH
PRESSURE.
12Z SUNDAY ONWARD...MVFR/OCCNLY IFR IN SHSN WITH FRONTAL PASSAGE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG
SHORT TERM...JMG
LONG TERM...NEILES
AVIATION...JMG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
935 AM EST WED JAN 25 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH TODAY. A COLD FRONT AND
LOW PRESSURE WILL APPROACH THE CAROLINAS FROM THE WEST ON THURSDAY
AND PUSH EAST OF THE AREA ON FRIDAY. WEAK HIGH PRESSURE WILL BUILD
IN FROM THE WEST FRIDAY AND SATURDAY...BEFORE ANOTHER FRONT BRINGS
MUCH COOLER AIR TO THE REGION SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 930 AM WEDNESDAY... CLOUDS AND FOG THAT AFFECTED SOUTHERN EDGE OF
CWA EARLIER HAVE JUST ABOUT DISSIPATED. OTHERWISE... THE DAY WILL
CONTINUE AS ADVERTISED IN EARLIER DISCUSSION. THERE WILL BE QUITE A
BIT OF SUNSHINE... BUT THE GRADUAL INCREASE IN CLOUDS WILL OCCUR AS
MOISTURE SPREADS NORTHWARD AND EASTWARD FROM LOW IN THE TX/LA AREA.
AS OF 635 AM WEDNESDAY...AN AREA OF LOW CLOUDS AND FOG CONTINUE TO
SKIRT THE SE PERIPHERY OF THE FORECAST AREA THIS MORNING. HOPEFULLY
IT WILL CONTINUE MOVING SE...BUT THE RUC BNDRY LAYER RH/S IMPLY THAT
IT COULD SPREAD A LITTLE FATHER WEST. WE/LL KEEP AN EYE ON IT.
AS OF 355 AM WEDNESDAY...THE AREA OF DENSE FOG AND LOW CLOUDS HAS
INDEED BEEN PUSHING SLOWLY SOUTHWARD ACROSS THE FA. ACTUALLY...THE
GRIDS HAVE DONE A PRETTY GOOD JOB CAPTURING THIS TREND...AT LEAST
BASED ON WHAT I CAN DISCERN ON THE FOG PRODUCT. THE REST OF THE NEAR
TERM LOOKS GOOD AND ONLY A FEW TWEAKS WERE MADE.
PREVIOUS DISCUSSION...
A BACK DOOR COLD FRONT WILL PUSH ACROSS THE FA EARLY THIS MORNING.
JUST ALONG AND AHEAD OF THE FRONT...AREAS OF FOG AND STRATUS HAVE
DEVELOPED OVER THE SRN NC PIEDMONT AND OVER THE NW PIEDMONT OF SOUTH
CAROLINA. HOWEVER...BUFKIT SOUNDINGS IMPLY THAT DRIER AIR SHOULD MIX
OUT THE FOG AND STRATUS OVER THE NC PIEDMONT IN SHORT ORDER...AND
PUSH IT GRADUALLY SOUTHWARD OVER THE ERN SC UPSTATE. I DON/T THINK
ANY LOW CLOUDS WILL LAST PAST ABOUT 6 AM...AND THEY MAY EVEN MIX OUT
BEFORE THAT. OTHERWISE HIGH CLOUDS WILL GRADUALLY THICKEN AND LOWER
DURING THE COURSE OF THE DAY AS AN UPPER LOW BEGINS TO LIFT OUT
ACROSS THE SRN PLAINS. THERE IS A WELL DEFINED WARM FRONTAL BNDRY
DOWN ALONG THE GULF COAST...AND AS THIS STARTS TO LIFT NORTH IN
RESPONSE TO THE APPROACHING TROUGH...LOW CLOUDS SHOULD SPREAD ACROSS
THE FA LATER TONIGHT. PATCHY AREAS OF RAIN SHOULD ALSO BEGIN TO
DEVELOP...PARTICULARLY ALONG THE SRN AND ERN SLOPES OF THE BLUE
RIDGE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 320 AM WEDNESDAY...LOW LEVEL FLOW WILL CONTINUE TO INCREASE
DURING THE DAY THURSDAY...RESULTING IN GRADUAL INCREASE OF MOISTURE
LEVELS...AS WELL AS IN INCREASE IN ISENTROPIC UPGLIDE AND ESPECIALLY
MECHANICAL/UPSLOPE-INDUCED LIFT. THIS WILL RESULT IN GRADUAL
INCREASE IN POPS THROUGHOUT THE DAY...WITH LIKELY POPS ACROSS THE
SOUTHWEST NC MTNS BY AFTERNOON...EXPANDING TO THE REMAINDER OF THE
NC MTNS BY 00Z FRIDAY...AS DEEP MOISTURE PUSHES INTO THE REGION IN
ADVANCE OF FRONTAL ZONE. THE VERY MOIST FRONTAL ZONE WILL SWEEP
ACROSS THE AREA THURSDAY NIGHT...WARRANTING CATEGORICAL POPS IN ALL
AREAS BY 12Z FRIDAY. PROGGED CAPE VALUES ARE VERY LOW...BUT NON-ZERO
THROUGHOUT THE EVENT...ENOUGH TO WARRANT A SLIGHT CHANCE THUNDER
MENTION IN SOME AREAS. CONSIDERING THE VERY STRONG DEEP-LAYER
SHEAR...A LOW-END SEVERE WEATHER THREAT WILL EXIST...WITH THE
POSSIBILITY OF A DISCRETE CELL OR TWO AHEAD OF THE FRONT THURSDAY
AFTERNOON/EVENING...THEN WITH A POTENTIAL SHALLOW QLCS ALONG THE
FRONT THURSDAY NIGHT.
WEAK LOW PRESSURE DEVELOPING THE FRONT TO OUR SOUTHWEST IS EXPECTED
TO RESULT IN THE BOUNDARY SLOWING DOWN A BIT AS IT PUSHES EAST OF
THE REGION EARLY FRIDAY...SO POPS WILL BE RETAINED ACROSS THE
EASTERN AND SOUTHERN ZONES DURING THE MORNING. OTHERWISE...STRONG
COLD ADVECTION WILL RESULT IN TEMPS FALLING THROUGH THE DAY ACROSS
THE MTNS. NEVERTHELESS...THE POST-FRONTAL AIR MASS IS STILL OF
PACIFIC ORIGINS...SO TEMPS THROUGH THE REMAINDER OF THE SHORT TERM
WILL REMAIN A LITTLE ABOVE NORMAL.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 235 AM WEDNESDAY...THE MEDIUM RANGE BEGINS WITH A VERY BROAD
TROUGH OVER THE EASTERN HALF OF THE COUNTRY. HOWEVER...A STRONG
SHORT WAVE TROUGH DIVING OUT OF THE UPPER MIDWEST SATURDAY NIGHT
WILL SHARPEN THE LONG WAVE PATTERN...BRINGING A COLD FRONT WILL
SIGNIFICANTLY COLDER AIR INTO THE AREA ON SUNDAY. WITH WEAK RIDGING
DOMINATING THE LOW LEVELS ACROSS THE REGION...MOISTURE WILL BE NON
EXISTENT AHEAD OF THIS FRONT...BUT SMALL POPS WILL BE CARRIED ALONG
THE TENN BORDER FOR NW FLOW MOISTURE BEHIND THE FRONT. THE MOST
OBVIOUS IMPACT OF THE FRONT WILL BE TO BRING TEMPERATURES BELOW
CLIMO FOR A COUPLE OF DAYS.
THE LATTER HALF OF THE EXTENDED WILL SEE MODERATING TEMPS...AS THE
EASTERN TROUGH PROGRESSES QUICKLY OFF THE EAST COAST...LEAVING
BEHIND A LOW AMPLITUDE/QUASI-ZONAL FLOW REGIME ACROSS MUCH OF THE
CONUS THROUGH MID-WEEK. THE WEATHER SHOULD ALSO BE DRY FOR A
CHANGE.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...MID MORNING TAF UPDATE REQUIRES NO MAJOR CHANGES. OTHER
THAN SOME HIGH CLOUDS... THE WEATHER WILL BE FAIR THROUGH THE DAY.
THE NEARLY CALM WIND SHOULD BECOME LIGHT NE THIS MORNING...AND THEN
VEER TO ESE DURING THE AFTN. A WARM FRONT WILL APPROACH THE REGION
FROM THE SOUTH TONIGHT...WITH MVFR CIGS EXPECTED TOWARD THE END OF
THE TAF PERIOD.
ELSEWHERE...WINDS WILL GENERALLY BE OUT OF THE N TO NE THIS
MORNING...WITH LIGHT EASTERLY WINDS THIS AFTN OVER THE UPSTATE...AND
SOUTH AT KAVL/KHKY. A WARM FRONT WILL SPREAD CLOUDS AND FEW SHRA
BACK ACROSS THE REGION TONIGHT. CIGS SHOULD FALL THROUGH THE MVFR
RANGE LATE TONIGHT. THE MODEL GUIDANCE TAKES CIGS DOWN INTO THE
LIFR/VLIFR RANGE BETWEEN 12 AND 15 UTC AT MANY SITES...WHICH IS JUST
OUTSIDE THE VALID PERIOD OF THE TAF. HOPEFULLY A COUPLE DAYS WITH
ABOVE NORMAL TEMPS WILL DRY OUT AND WARM UP THE GROUND ENUF THAT IFR
OR LOWER CIGS WILL HOLD OFF UNTIL PCPN RATES PICK UP LATER ON FRIDAY.
OUTLOOK... AN APPROACHING LOW PRESSURE SYSTEM THURSDAY WILL PRODUCE
CEILING AND VISIBILITY RESTRICTIONS IN PRECIPITATION AND LOW CIGS
THROUGH THURSDAY NIGHT. CONDITIONS SHOULD IMPROVE DURING THE DAY ON
FRIDAY...THOUGH THERE IS A CHANCE THAT CONDITIONS WON/T IMPROVE
UNTIL FRIDAY NIGHT. FAIR WEATHER IS THEN EXPECTED SAT AND SUN.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JDL
NEAR TERM...LGL/MCAVOY
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...LGL/MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
635 AM EST WED JAN 25 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH TODAY. A COLD FRONT AND
LOW PRESSURE WILL APPROACH THE CAROLINAS FROM THE WEST ON THURSDAY
AND PUSH EAST OF THE AREA ON FRIDAY. WEAK HIGH PRESSURE WILL BUILD
IN FROM THE WEST FRIDAY AND SATURDAY...BEFORE ANOTHER FRONT BRINGS
MUCH COOLER AIR TO THE REGION SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 635 AM WEDNESDAY...AN AREA OF LOW CLOUDS AND FOG CONTINUE TO
SKIRT THE SE PERIPHERY OF THE FORECAST AREA THIS MORNING. HOPEFULLY
IT WILL CONTINUE MOVING SE...BUT THE RUC BNDRY LAYER RH/S IMPLY THAT
IT COULD SPREAD A LITTLE FATHER WEST. WE/LL KEEP AN EYE ON IT.
AS OF 355 AM WEDNESDAY...THE AREA OF DENSE FOG AND LOW CLOUDS HAS
INDEED BEEN PUSHING SLOWLY SOUTHWARD ACROSS THE FA. ACTUALLY...THE
GRIDS HAVE DONE A PRETTY GOOD JOB CAPTURING THIS TREND...AT LEAST
BASED ON WHAT I CAN DISCERN ON THE FOG PRODUCT. THE REST OF THE NEAR
TERM LOOKS GOOD AND ONLY A FEW TWEAKS WERE MADE.
PREVIOUS DISCUSSION...
A BACK DOOR COLD FRONT WILL PUSH ACROSS THE FA EARLY THIS MORNING.
JUST ALONG AND AHEAD OF THE FRONT...AREAS OF FOG AND STRATUS HAVE
DEVELOPED OVER THE SRN NC PIEDMONT AND OVER THE NW PIEDMONT OF SOUTH
CAROLINA. HOWEVER...BUFKIT SOUNDINGS IMPLY THAT DRIER AIR SHOULD MIX
OUT THE FOG AND STRATUS OVER THE NC PIEDMONT IN SHORT ORDER...AND
PUSH IT GRADUALLY SOUTHWARD OVER THE ERN SC UPSTATE. I DON/T THINK
ANY LOW CLOUDS WILL LAST PAST ABOUT 6 AM...AND THEY MAY EVEN MIX OUT
BEFORE THAT. OTHERWISE HIGH CLOUDS WILL GRADUALLY THICKEN AND LOWER
DURING THE COURSE OF THE DAY AS AN UPPER LOW BEGINS TO LIFT OUT
ACROSS THE SRN PLAINS. THERE IS A WELL DEFINED WARM FRONTAL BNDRY
DOWN ALONG THE GULF COAST...AND AS THIS STARTS TO LIFT NORTH IN
RESPONSE TO THE APPROACHING TROUGH...LOW CLOUDS SHOULD SPREAD ACROSS
THE FA LATER TONIGHT. PATCHY AREAS OF RAIN SHOULD ALSO BEGIN TO
DEVELOP...PARTICULARLY ALONG THE SRN AND ERN SLOPES OF THE BLUE
RIDGE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 320 AM WEDNESDAY...LOW LEVEL FLOW WILL CONTINUE TO INCREASE
DURING THE DAY THURSDAY...RESULTING IN GRADUAL INCREASE OF MOISTURE
LEVELS...AS WELL AS IN INCREASE IN ISENTROPIC UPGLIDE AND ESPECIALLY
MECHANICAL/UPSLOPE-INDUCED LIFT. THIS WILL RESULT IN GRADUAL
INCREASE IN POPS THROUGHOUT THE DAY...WITH LIKELY POPS ACROSS THE
SOUTHWEST NC MTNS BY AFTERNOON...EXPANDING TO THE REMAINDER OF THE
NC MTNS BY 00Z FRIDAY...AS DEEP MOISTURE PUSHES INTO THE REGION IN
ADVANCE OF FRONTAL ZONE. THE VERY MOIST FRONTAL ZONE WILL SWEEP
ACROSS THE AREA THURSDAY NIGHT...WARRANTING CATEGORICAL POPS IN ALL
AREAS BY 12Z FRIDAY. PROGGED CAPE VALUES ARE VERY LOW...BUT NON-ZERO
THROUGHOUT THE EVENT...ENOUGH TO WARRANT A SLIGHT CHANCE THUNDER
MENTION IN SOME AREAS. CONSIDERING THE VERY STRONG DEEP-LAYER
SHEAR...A LOW-END SEVERE WEATHER THREAT WILL EXIST...WITH THE
POSSIBILITY OF A DISCRETE CELL OR TWO AHEAD OF THE FRONT THURSDAY
AFTERNOON/EVENING...THEN WITH A POTENTIAL SHALLOW QLCS ALONG THE
FRONT THURSDAY NIGHT.
WEAK LOW PRESSURE DEVELOPING THE FRONT TO OUR SOUTHWEST IS EXPECTED
TO RESULT IN THE BOUNDARY SLOWING DOWN A BIT AS IT PUSHES EAST OF
THE REGION EARLY FRIDAY...SO POPS WILL BE RETAINED ACROSS THE
EASTERN AND SOUTHERN ZONES DURING THE MORNING. OTHERWISE...STRONG
COLD ADVECTION WILL RESULT IN TEMPS FALLING THROUGH THE DAY ACROSS
THE MTNS. NEVERTHELESS...THE POST-FRONTAL AIR MASS IS STILL OF
PACIFIC ORIGINS...SO TEMPS THROUGH THE REMAINDER OF THE SHORT TERM
WILL REMAIN A LITTLE ABOVE NORMAL.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 235 AM WEDNESDAY...THE MEDIUM RANGE BEGINS WITH A VERY BROAD
TROUGH OVER THE EASTERN HALF OF THE COUNTRY. HOWEVER...A STRONG
SHORT WAVE TROUGH DIVING OUT OF THE UPPER MIDWEST SATURDAY NIGHT
WILL SHARPEN THE LONG WAVE PATTERN...BRINGING A COLD FRONT WILL
SIGNIFICANTLY COLDER AIR INTO THE AREA ON SUNDAY. WITH WEAK RIDGING
DOMINATING THE LOW LEVELS ACROSS THE REGION...MOISTURE WILL BE NON
EXISTENT AHEAD OF THIS FRONT...BUT SMALL POPS WILL BE CARRIED ALONG
THE TENN BORDER FOR NW FLOW MOISTURE BEHIND THE FRONT. THE MOST
OBVIOUS IMPACT OF THE FRONT WILL BE TO BRING TEMPERATURES BELOW
CLIMO FOR A COUPLE OF DAYS.
THE LATTER HALF OF THE EXTENDED WILL SEE MODERATING TEMPS...AS THE
EASTERN TROUGH PROGRESSES QUICKLY OFF THE EAST COAST...LEAVING
BEHIND A LOW AMPLITUDE/QUASI-ZONAL FLOW REGIME ACROSS MUCH OF THE
CONUS THROUGH MID-WEEK. THE WEATHER SHOULD ALSO BE DRY FOR A
CHANGE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...OTHER THAN SOME HIGH CLOUDS...THE WEATHER WILL BE FAIR
THROUGH THE DAY. WINDS WILL BE LIGHT NE THIS MORNING...AND THEY
SHOULD VEER TO ESE BY THIS AFTN. A WARM FRONT WILL APPROACH THE
REGION FROM THE SOUTH TONIGHT...WITH MVFR CIGS EXPECTED TOWARD THE
END OF THE TAF PERIOD.
ELSEWHERE...WINDS WILL GENERALLY BE OUT OF THE N TO NE THIS
MORNING...WITH LIGHT EASTERLY WINDS THIS AFTN OVER THE UPSTATE...AND
SOUTH AT KAVL/KHKY. A WARM FRONT WILL SPREAD CLOUDS AND FEW SHRA
BACK ACROSS THE REGION TONIGHT. CIGS SHOULD FALL THROUGH THE MVFR
RANGE LATE TONIGHT. THE MODEL GUIDANCE TAKES CIGS DOWN INTO THE
LIFR/VLIFR RANGE BETWEEN 12 AND 15 UTC AT MANY SITES...WHICH IS JUST
OUTSIDE THE VALID PERIOD OF THE TAF. HOPEFULLY A COUPLE DAYS WITH
ABOVE NORMAL TEMPS WILL DRY OUT AND WARM UP THE GROUND ENUF THAT IFR
OR LOWER CIGS WILL HOLD OFF UNTIL PCPN RATES PICK UP LATER ON FRIDAY.
OUTLOOK... AN APPROACHING LOW PRESSURE SYSTEM THURSDAY WILL PRODUCE
CEILING AND VISIBILITY RESTRICTIONS IN PRECIPITATION AND LOW CIGS
THROUGH THURSDAY NIGHT. CONDITIONS SHOULD IMPROVE DURING THE DAY ON
FRIDAY...THOUGH THERE IS A CHANCE THAT CONDITIONS WON/T IMPROVE
UNTIL FRIDAY NIGHT. FAIR WEATHER IS THEN EXPECTED SAT AND SUN.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JDL
NEAR TERM...MCAVOY
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
944 AM CST WED JAN 25 2012
.UPDATE...
SHOWERS ARE MOVING ACROSS NORTHEASTERN ARKANSAS...THE MISSOURI
BOOTHEEL...AND WESTERN TENNESSEE. MODELS ARE SHOWING ADDITIONAL
SHOWERS AND THUNDERSTORMS DEVELOPING OVER NORTHERN MISSISSIPPI AND
SOUTHERN ARKANSAS LATER THIS MORNING AND INTO THE AFTERNOON HOURS.
A LARGE AREA OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED AHEAD OF A
COLD FRONT AND LOW PRESSURE SYSTEM OVER TEXAS AND WILL CONTINUE
MOVING EAST. FORECAST LOOKS GOOD AT THIS TIME AND NO UPDATE IS NEEDED
TO GRIDS.
RRH
&&
.PREV DISCUSSION... /ISSUED 719 AM CST WED JAN 25 2012/
UPDATE...WARM FRONT LOCATED ALONG THE GULF COAST THIS MORNING IS
BEGINNING TO SHOW SIGNS OF MOVING NORTH...AND TOWARDS THE MID
SOUTH LATER TODAY. BASED ON LATEST CONVECTIVE TRENDS AND
THE RUC INDICATING INCREASING ELEVATED INSTABILITY ACROSS THE
FORECAST AREA...INCREASED MENTION OF ELEVATED THUNDER IN THE
FORECAST FOR THE REMAINDER OF THE DAY.
UPDATED GRIDS ALREADY PUBLISHED.
CJC
PREV DISCUSSION... /ISSUED 456 AM CST WED JAN 25 2012/
DISCUSSION...WATER VAPOR SATELLITE/UPPER AIR PROFILER TRENDS THIS
MORNING PLACE AN UPPER LEVEL LOW NEAR EL PASO TEXAS WITH A SURFACE
LOW CENTERED JUST SOUTHWEST OF SAN ANTONIO TEXAS. A WARM FRONT
EXTENDS FROM THIS SURFACE LOW UP TO WACO TEXAS AND THEN BACK
TOWARDS THE LOUISIANA/ALABAMA COAST AND FLORIDA PANHANDLE. CLOUDY
SKIES AND RAIN ENCOMPASS MUCH OF THE MID SOUTH AS OF THIS
MORNING/S FORECAST ISSUANCE. AS OF 4 AM CST...TEMPERATURES RANGE
FROM THE UPPER 30S TO LOWER 40S ACROSS THE NORTHERN THIRD OF THE
MID SOUTH AND MIDDLE 40S TO AROUND 50 DEGREES ACROSS AREAS SOUTH
OF I-40. THE POTENTIAL FOR A STRONG THUNDERSTORM OR TWO ACROSS
NORTHEAST MISSISSIPPI THURSDAY MORNING INTO EARLY THURSDAY
AFTERNOON IS THE PRIMARY CONCERN IN THIS MORNING/S FORECAST.
SHORT TERM...(TODAY THROUGH THURSDAY)...RAIN HAS FINALLY
ARRIVED OVERNIGHT ACROSS THE MID SOUTH COURTESY OF ISENTROPIC
ASCENT LIFTING GULF OF MEXICO MOISTURE AND PRODUCING OVERRUNNING
RAIN NORTH OF THE WARM FRONT...CURRENTLY SITUATED ALONG THE
LOUISIANA/ALABAMA COAST THIS MORNING. MODELS ARE IN DECENT
AGREEMENT WITH THIS OVERRUNNING RAIN OCCURRING THIS MORNING ACROSS
THE ENTIRE MID SOUTH. THE ABOVE MENTIONED WARM FRONT WILL BEGIN
LIFTING NORTH TODAY...AND REACHING AS FAR NORTH AS PORTIONS OF
NORTHEAST MISSISSIPPI AS EARLY AS LATE AFTERNOON/EARLY THIS
EVENING AS THE UPPER LEVEL LOW AND ASSOCIATED SURFACE LOW BEGIN TO
LIFT NORTHEAST INTO THE LOWER MISSISSIPPI VALLEY. KEPT LOWER POPS
ACROSS NORTHEAST MISSISSIPPI THIS AFTERNOON AS BEST COVERAGE BY
FAR WILL REMAIN NORTH OF THE WARM FRONT. OVERALL INSTABILITY WILL
REMAIN LOW THROUGHOUT THE DAY. HOWEVER...DID ADD ISOLATED THUNDER
FOR THE SOUTHERN TIER OR TWO OF COUNTIES ACROSS NORTH MISSISSIPPI
FOR LATE AFTERNOON AS THE WARM FRONT APPROACHES. HIGH TEMPERATURES
TODAY WILL RANGE FROM THE LOWER TO MIDDLE 40S ACROSS NORTHEAST
ARKANSAS TO FAR NORTHWEST TENNESSEE...AND UPPER 50S TO LOWER 60S
IN CLOSER PROXIMITY TO THE APPROACHING WARM FRONT.
THE WARM FRONT WILL BISECT THE MID SOUTH FROM SOUTHWEST TO
NORTHEAST TONIGHT AS A SURFACE AND UPPER LEVEL LOW MOVE JUST TO
THE SOUTH OF THE FORECAST AREA INTO THURSDAY. SHOWERS AND A FEW
THUNDERSTORMS ARE EXPECTED ACROSS THE MID SOUTH TONIGHT INTO
THURSDAY. DESPITE FAVORABLE UPPER LEVEL DIVERGENCE /LIFT/ AND
SHEAR...NOT OVERLY IMPRESSED WITH QUALITY OF INSTABILITY FORECAST
ACROSS THE MID SOUTH. BEST INSTABILITY AXIS WILL REMAIN JUST TO
THE SOUTH OF THE AREA AND WIDESPREAD RAIN SHOWERS/EXTENSIVE CLOUD
COVER HAVE RESULTED IN LOW CONFIDENCE ON STRONG/SEVERE
THUNDERSTORM THREAT DURING THIS TIMEFRAME. NONETHELESS...DAY/EVENING
SHIFTS WILL CONTINUE TO MONITOR TRENDS AND ADJUST FORECAST AS NECESSARY
IF THIS INSTABILITY AXIS CREEPS FURTHER NORTH THAN CURRENTLY
INDICATED BY THE LATEST SHORT TERM MODELS.
LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)...
RAIN SHOWERS WILL GRADUALLY COME TO AN END THURSDAY NIGHT AS COOL HIGH
PRESSURE BUILDS BACK INTO THE MID SOUTH BY FRIDAY MORNING. MODELS
INDICATE ANOTHER COLD FRONT WILL MOVE INTO THE AREA FRIDAY NIGHT.
HOWEVER...ANALYSIS OF MODEL SOUNDINGS INDICATES LOW LEVEL
PRECIPITATION WILL REMAIN NEARLY NON-EXISTENT AND WILL RESULT IN
SOME MID/HIGH LEVEL CLOUDS PUSHING ACROSS THE AREA FRIDAY NIGHT
INTO SATURDAY MORNING. 00Z GFS/ECMWF LONG TERM MODELS INDICATE
SURFACE HIGH PRESSURE WILL BUILD BACK IN AGAIN ACROSS THE LOWER
MISSISSIPPI VALLEY SATURDAY THROUGH MONDAY WITH CYCLONIC FLOW
ALOFT. CHANCES FOR RAIN SHOWERS WILL RETURN BY NEXT TUESDAY AS
HIGH PRESSURE MOVES EAST AND ANOTHER COLD FRONT BEGINS TO MOVE
FROM THE CENTRAL/SOUTHERN PLAINS INTO THE MIDDLE/LOWER MISSISSIPPI
VALLEYS BY THE MIDDLE OF NEXT WEEK.
CJC
&&
.AVIATION...
12Z TAF CYCLE
LIGHT RAIN IS FALLING OUT OF FAIRLY A FAIRLY HIGH CLOUD
DECK...RANGING FROM NEARLY 10000 FEET AT MKL TO 5000 FEET AT MEM.
CIGS WILL GRADUALLY LOWER DURING THE DAY AND RAIN WILL BECOME
HEAVIER. EXPECT MVFR CIGS TO PREVAIL AT ALL SITES TODAY WITH MVFR
TO VFR VIS. AFTER SUNSET...IFR CIGS ARE EXPECTED WITH POSSIBLE
LIFR CIGS TOWARD MORNING. INCLUDED TEMPO 400 FT CIGS AT JBR AND
MEM PRIOR TO SUNRISE LATE TONIGHT. WINDS WILL REMAIN GENERALLY
FROM THE EAST AS A SURFACE LOW DEVELOPS OVER EAST TEXAS.
JDS
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 55 53 60 39 / 90 100 100 50
MKL 52 49 59 38 / 100 90 100 50
JBR 46 44 49 35 / 100 100 100 30
TUP 62 57 69 42 / 70 80 100 70
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
719 AM CST WED JAN 25 2012
.UPDATE...WARM FRONT LOCATED ALONG THE GULF COAST THIS MORNING IS
BEGINNING TO SHOW SIGNS OF MOVING NORTH...AND TOWARDS THE MID
SOUTH LATER TODAY. BASED ON LATEST CONVECTIVE TRENDS AND
THE RUC INDICATING INCREASING ELEVATED INSTABILITY ACROSS THE
FORECAST AREA...INCREASED MENTION OF ELEVATED THUNDER IN THE
FORECAST FOR THE REMAINDER OF THE DAY.
UPDATED GRIDS ALREADY PUBLISHED.
CJC
&&
.PREV DISCUSSION... /ISSUED 534 AM CST WED JAN 25 2012/
UPDATE...AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 456 AM CST WED JAN 25 2012/
DISCUSSION...WATER VAPOR SATELLITE/UPPER AIR PROFILER TRENDS THIS
MORNING PLACE AN UPPER LEVEL LOW NEAR EL PASO TEXAS WITH A SURFACE
LOW CENTERED JUST SOUTHWEST OF SAN ANTONIO TEXAS. A WARM FRONT
EXTENDS FROM THIS SURFACE LOW UP TO WACO TEXAS AND THEN BACK
TOWARDS THE LOUISIANA/ALABAMA COAST AND FLORIDA PANHANDLE. CLOUDY
SKIES AND RAIN ENCOMPASS MUCH OF THE MID SOUTH AS OF THIS
MORNING/S FORECAST ISSUANCE. AS OF 4 AM CST...TEMPERATURES RANGE
FROM THE UPPER 30S TO LOWER 40S ACROSS THE NORTHERN THIRD OF THE
MID SOUTH AND MIDDLE 40S TO AROUND 50 DEGREES ACROSS AREAS SOUTH
OF I-40. THE POTENTIAL FOR A STRONG THUNDERSTORM OR TWO ACROSS
NORTHEAST MISSISSIPPI THURSDAY MORNING INTO EARLY THURSDAY
AFTERNOON IS THE PRIMARY CONCERN IN THIS MORNING/S FORECAST.
SHORT TERM...(TODAY THROUGH THURSDAY)...RAIN HAS FINALLY
ARRIVED OVERNIGHT ACROSS THE MID SOUTH COURTESY OF ISENTROPIC
ASCENT LIFTING GULF OF MEXICO MOISTURE AND PRODUCING OVERRUNNING
RAIN NORTH OF THE WARM FRONT...CURRENTLY SITUATED ALONG THE
LOUISIANA/ALABAMA COAST THIS MORNING. MODELS ARE IN DECENT
AGREEMENT WITH THIS OVERRUNNING RAIN OCCURRING THIS MORNING ACROSS
THE ENTIRE MID SOUTH. THE ABOVE MENTIONED WARM FRONT WILL BEGIN
LIFTING NORTH TODAY...AND REACHING AS FAR NORTH AS PORTIONS OF
NORTHEAST MISSISSIPPI AS EARLY AS LATE AFTERNOON/EARLY THIS
EVENING AS THE UPPER LEVEL LOW AND ASSOCIATED SURFACE LOW BEGIN TO
LIFT NORTHEAST INTO THE LOWER MISSISSIPPI VALLEY. KEPT LOWER POPS
ACROSS NORTHEAST MISSISSIPPI THIS AFTERNOON AS BEST COVERAGE BY
FAR WILL REMAIN NORTH OF THE WARM FRONT. OVERALL INSTABILITY WILL
REMAIN LOW THROUGHOUT THE DAY. HOWEVER...DID ADD ISOLATED THUNDER
FOR THE SOUTHERN TIER OR TWO OF COUNTIES ACROSS NORTH MISSISSIPPI
FOR LATE AFTERNOON AS THE WARM FRONT APPROACHES. HIGH TEMPERATURES
TODAY WILL RANGE FROM THE LOWER TO MIDDLE 40S ACROSS NORTHEAST
ARKANSAS TO FAR NORTHWEST TENNESSEE...AND UPPER 50S TO LOWER 60S
IN CLOSER PROXIMITY TO THE APPROACHING WARM FRONT.
THE WARM FRONT WILL BISECT THE MID SOUTH FROM SOUTHWEST TO
NORTHEAST TONIGHT AS A SURFACE AND UPPER LEVEL LOW MOVE JUST TO
THE SOUTH OF THE FORECAST AREA INTO THURSDAY. SHOWERS AND A FEW
THUNDERSTORMS ARE EXPECTED ACROSS THE MID SOUTH TONIGHT INTO
THURSDAY. DESPITE FAVORABLE UPPER LEVEL DIVERGENCE /LIFT/ AND
SHEAR...NOT OVERLY IMPRESSED WITH QUALITY OF INSTABILITY FORECAST
ACROSS THE MID SOUTH. BEST INSTABILITY AXIS WILL REMAIN JUST TO
THE SOUTH OF THE AREA AND WIDESPREAD RAIN SHOWERS/EXTENSIVE CLOUD
COVER HAVE RESULTED IN LOW CONFIDENCE ON STRONG/SEVERE
THUNDERSTORM THREAT DURING THIS TIMEFRAME. NONETHELESS...DAY/EVENING
SHIFTS WILL CONTINUE TO MONITOR TRENDS AND ADJUST FORECAST AS NECESSARY
IF THIS INSTABILITY AXIS CREEPS FURTHER NORTH THAN CURRENTLY
INDICATED BY THE LATEST SHORT TERM MODELS.
LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)...
RAIN SHOWERS WILL GRADUALLY COME TO AN END THURSDAY NIGHT AS COOL HIGH
PRESSURE BUILDS BACK INTO THE MID SOUTH BY FRIDAY MORNING. MODELS
INDICATE ANOTHER COLD FRONT WILL MOVE INTO THE AREA FRIDAY NIGHT.
HOWEVER...ANALYSIS OF MODEL SOUNDINGS INDICATES LOW LEVEL
PRECIPITATION WILL REMAIN NEARLY NON-EXISTENT AND WILL RESULT IN
SOME MID/HIGH LEVEL CLOUDS PUSHING ACROSS THE AREA FRIDAY NIGHT
INTO SATURDAY MORNING. 00Z GFS/ECMWF LONG TERM MODELS INDICATE
SURFACE HIGH PRESSURE WILL BUILD BACK IN AGAIN ACROSS THE LOWER
MISSISSIPPI VALLEY SATURDAY THROUGH MONDAY WITH CYCLONIC FLOW
ALOFT. CHANCES FOR RAIN SHOWERS WILL RETURN BY NEXT TUESDAY AS
HIGH PRESSURE MOVES EAST AND ANOTHER COLD FRONT BEGINS TO MOVE
FROM THE CENTRAL/SOUTHERN PLAINS INTO THE MIDDLE/LOWER MISSISSIPPI
VALLEYS BY THE MIDDLE OF NEXT WEEK.
CJC
&&
.AVIATION...
12Z TAF CYCLE
LIGHT RAIN IS FALLING OUT OF FAIRLY A FAIRLY HIGH CLOUD
DECK...RANGING FROM NEARLY 10000 FEET AT MKL TO 5000 FEET AT MEM.
CIGS WILL GRADUALLY LOWER DURING THE DAY AND RAIN WILL BECOME
HEAVIER. EXPECT MVFR CIGS TO PREVAIL AT ALL SITES TODAY WITH MVFR
TO VFR VIS. AFTER SUNSET...IFR CIGS ARE EXPECTED WITH POSSIBLE
LIFR CIGS TOWARD MORNING. INCLUDED TEMPO 400 FT CIGS AT JBR AND
MEM PRIOR TO SUNRISE LATE TONIGHT. WINDS WILL REMAIN GENERALLY
FROM THE EAST AS A SURFACE LOW DEVELOPS OVER EAST TEXAS.
JDS
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 55 53 60 39 / 90 100 100 50
MKL 52 49 59 38 / 100 90 100 50
JBR 46 44 49 35 / 100 100 100 30
TUP 62 57 69 42 / 70 80 100 70
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1001 AM CST WED JAN 25 2012
.DISCUSSION...
LINE OF STRONG/SEVERE THUNDERSTORMS MAKING PROGRESS MOVING EASTWARD
ACROSS SOUTHEAST TEXAS THIS MORNING WITH A TORNADO WATCH IN EFFECT
UNTIL 11 AM. NORTHERN HALF OF THE LINE (ROUGHLY NORTH OF I-10) IS
MOVING FASTER THAN THE SOUTHERN HALF OF THE LINE. WE WILL PROBABLY
BE ISSUING ADDITIONAL FLOOD ADVISORIES TO COVER THE POTENTIAL FOR
WIDESPREAD 1 TO 3 INCH RAINFALL TOTALS ACROSS THE SOUTHERN HALF OF
THIS STORM COMPLEX...AND THIS AREA WILL ALSO BE CLOSELY MONITORED FOR
THE POTENTIAL FOR SEVERE STORM DEVELOPMENT. HIGHER RAINFALL TOTALS
CANNOT BE RULED OUT.
UPDATED THE MORNING FORECAST WITH HIGHER RAIN CHANCES EAST AND COOLER
TEMPERATURES WEST. 42
&&
.PREV DISCUSSION... /ISSUED 738 AM CST WED JAN 25 2012/
UPDATE...
EXTENDED THE TORNADO WATCH INTO CHAMBERS...LIBERTY...SAN JACINTO
COUNTIES...AND GALVESTON BAY.
PREV DISCUSSION... /ISSUED 634 AM CST WED JAN 25 2012/
AVIATION...
MAIN AVIATION CONCERN WILL BE PERIODS OF HEAVY RAINFALL LIMITING
VISBIES (MVFR) AND WIND GUSTS THAT COULD EXCEED 35 KTS WITHIN STRONGEST
STORMS. IN THE MEANTIME...A 50 KT LL JET HAS SHORT TERM WIND SHEAR
IN CURRENT PACKAGE...OR BEFORE THUNDERSTORMS ARRIVE. TIMING HAS THE
BULK OF CONVECTION OVER THE GREATER HOUSTON TERMINALS DURING THE
16-20Z TIME FRAME...PERIODS OF SCATTERED SHOWERS WITH AN EMBEDDED
STORM BOOK-ENDING THOSE TIMES. PRECIP BEGINNING TO FILL IN NICELY
AHEAD OF ONE-OF-TWO MAIN SQUALL LINES MOVING NE FROM SOUTH CENTRAL
TEXAS. THIS 50 KT LOW LEVEL JET AND AMPLE INFLOW INTO THE APPROACHING
MID-SURFACE LOW (NEAR KSAT) WILL AID IN KEEPING THE MAJORITY OF
THE DECKS AT IFR OR MVFR LEVELS...MORNING 20-25 SUSTAINED WINDS.
LINGERING -SHRA THROUGH EVENING AS THE SURFACE LOW PASSES EAST...WRAP
AROUND -RA THROUGH LATE EVENING WITH OVERCAST DECKS THROUGH REMAINDER
OF PERIOD UNDER WESTERLY FLOW. 31
PREV DISCUSSION... /ISSUED 540 AM CST WED JAN 25 2012/
UPDATE...
UPDATE FOR STRONGER WINDS THAN EARLIER EXPECTED. SUSTAINED 20 TO
25 MPH HAVE DEVELOPED AHEAD OF THE STORMS MOVING TOWARD THE
WESTERN COUNTIES OF THE FORECAST AREA. 09Z RUC INITIALIZED WELL
WITH THE WINDS. THE STRONGER WINDS WILL DIMINISH BY MIDDAY. WIND
ADVISORY OUT THROUGH NOON.
PREV DISCUSSION... /ISSUED 422 AM CST WED JAN 25 2012/
DISCUSSION...
SEVERE THUNDERSTORMS WITH DAMAGING WIND GUSTS AND ISOLATED
TORNADOES ARE A THREAT TODAY AS A STRONG STRONG STORM SYSTEM MOVES
ACROSS THE STATE. AT 3 AM THE UPPER LOW WAS LOCATED NEAR THE BIG
BEND AND A LARGE AREA OF THUNDERSTORMS WAS ALREADY AFFECTING THE
HILL COUNTRY. SE TX WAS UNDER THE STRONG INFLOW INTO THE SYSTEM
AND THE AIR MASS OVERHEAD WILL CONTINUE TO DESTABILIZE THIS
MORNING. THE STORM PREDICTION CENTER HAS ALREADY ISSUED A TORNADO
WATCH FOR MOST OF THE FORECAST AREA THROUGH 11 AM. AM EXPECTING
THAT THUNDERSTORMS WILL BEGIN AFFECTING LOCATIONS ALONG AND WEST
OF A LINE FROM COLLEGE STATION TO COLUMBUS BETWEEN 4 AND 6 AM...
AND THEN THE REMAINING AREAS ALONG AND WEST OF INTERSTATE 45 BY
MID MORNING.
THE MODELS WERE SIMILAR IN HOW THEY HANDLED THE MOVEMENT OF THE
UPPER LOW AND SURFACE FEATURES. EXPECT THE UPPER LOW TO SWING
EASTWARD THROUGH THE BIG BEND AREA THIS MORNING BEFORE HEADING TO
THE NORTHEAST THROUGH CENTRAL TEXAS TONIGHT. THE SURFACE FRONT
WILL BE RATHER SLOW TO MOVE EASTWARD AND LOCALLY HEAVY RAINFALL
IS LIKELY. THE PW/S REACH TO 1.7 INCHES...THE MAXIMUM HISTORICALLY
FOR THE END OF JANUARY AND ABOVE 2 STANDARD DEVIATIONS FROM
NORMAL. WILL WATCH THE MOVEMENT OF THE AREA OF THUNDERSTORMS
PUSHING EAST OF INTERSTATE 35 TO SEE IF ANY TRAINING OF STORMS
DEVELOP. MAY CONSIDER A FLOOD WATCH LATER THIS MORNING FOR THE
WESTERN COUNTIES OF THE FORECAST AREA IF THE LINE DOES NOT BEGIN
TO MOVE FASTER TO THE EAST.
THE COLD FRONT WILL BE A BIT SLOWER TO EXIT THROUGH SE TX THAN
EARLIER THOUGHT. THE CHANCES FOR STRONGER THUNDERSTORMS WITH
LOCALLY HEAVY RAINFALL WILL LINGER INTO THE MID AND LATE AFTERNOON
FOR LOCATIONS EAST OF INTERSTATE 45. WRAP AROUND MOISTURE WILL
THEN AFFECT THE FORECAST AREA TONIGHT AND THURSDAY AS THE UPPER
LOW MOVES ACROSS CENTRAL AND NORTH TEXAS.
FAIR AND COOLER WEATHER IS THEN IN STORE FOR THE REST OF THE
PERIOD. ANOTHER WEAK FRONT MOVES THROUGH ON SUNDAY BUT IT APPEARS
TO BE DRY FOR NOW AND WILL JUST REINFORCE THE COOL AND DRY AIR
OVERHEAD.
MARINE...
SMALL CRAFT ADVISORY IN EFFECT FOR ALL WATERS AS AN APPROACHING
STORM SYSTEM WILL INTRODUCE SOUTH-TO-NORTH MOVING BANDS OF HEAVY
RAINFALL AND STRONG THUNDERSTORMS WITHIN POCKETS OF RAIN SHOWERS.
ROBUST ONSHORE WINDS JUST UPSTREAM OF THE SURFACE TROUGH...WEAKENING
AS THE TROUGH NEARS AND PASSES EAST...THEN TURNING MODERATE OFFSHORE
LATTER THURSDAY WITHIN A TIGHT BACKSIDE GRADIENT. LOCAL BAY WATERS
WILL BE CHURNED UP WITH NEARSHORE 4 TO 5 FOOT SEA HEIGHTS...AS HIGH
AS 7 TO 8 FEET (WITH A SHORTER PERIOD) FURTHER OFFSHORE. IN THE
MEANTIME...MARINERS SHOULD CLOSELY MONITOR THE RADAR AND CURRENT
OBSERVATIONS THROUGH THE DAY AS WEATHER COULD QUICKLY TURN ROUGH
WITH ANY PASSING MARITIME STORM. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 63 48 60 42 63 / 100 30 30 10 10
HOUSTON (IAH) 72 52 63 45 65 / 100 40 20 10 10
GALVESTON (GLS) 72 55 64 50 62 / 100 50 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
JACKSON...LIBERTY...MADISON...MATAGORDA...MONTGOMERY...SAN
JACINTO...WALKER...WALLER...WASHINGTON...WHARTON.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...42
AVIATION/MARINE...45
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
738 AM CST WED JAN 25 2012
.UPDATE...
EXTENDED THE TORNADO WATCH INTO CHAMBERS...LIBERTY...SAN JACINTO
COUNTIES...AND GALVESTON BAY.
&&
.PREV DISCUSSION... /ISSUED 634 AM CST WED JAN 25 2012/
AVIATION...
MAIN AVIATION CONCERN WILL BE PERIODS OF HEAVY RAINFALL LIMITING
VISBIES (MVFR) AND WIND GUSTS THAT COULD EXCEED 35 KTS WITHIN STRONGEST
STORMS. IN THE MEANTIME...A 50 KT LL JET HAS SHORT TERM WIND SHEAR
IN CURRENT PACKAGE...OR BEFORE THUNDERSTORMS ARRIVE. TIMING HAS THE
BULK OF CONVECTION OVER THE GREATER HOUSTON TERMINALS DURING THE
16-20Z TIME FRAME...PERIODS OF SCATTERED SHOWERS WITH AN EMBEDDED
STORM BOOK-ENDING THOSE TIMES. PRECIP BEGINNING TO FILL IN NICELY
AHEAD OF ONE-OF-TWO MAIN SQUALL LINES MOVING NE FROM SOUTH CENTRAL
TEXAS. THIS 50 KT LOW LEVEL JET AND AMPLE INFLOW INTO THE APPROACHING
MID-SURFACE LOW (NEAR KSAT) WILL AID IN KEEPING THE MAJORITY OF
THE DECKS AT IFR OR MVFR LEVELS...MORNING 20-25 SUSTAINED WINDS.
LINGERING -SHRA THROUGH EVENING AS THE SURFACE LOW PASSES EAST...WRAP
AROUND -RA THROUGH LATE EVENING WITH OVERCAST DECKS THROUGH REMAINDER
OF PERIOD UNDER WESTERLY FLOW. 31
&&
PREV DISCUSSION... /ISSUED 540 AM CST WED JAN 25 2012/
UPDATE...
UPDATE FOR STRONGER WINDS THAN EARLIER EXPECTED. SUSTAINED 20 TO
25 MPH HAVE DEVELOPED AHEAD OF THE STORMS MOVING TOWARD THE
WESTERN COUNTIES OF THE FORECAST AREA. 09Z RUC INITIALIZED WELL
WITH THE WINDS. THE STRONGER WINDS WILL DIMINISH BY MIDDAY. WIND
ADVISORY OUT THROUGH NOON.
40
PREV DISCUSSION... /ISSUED 422 AM CST WED JAN 25 2012/
DISCUSSION...
SEVERE THUNDERSTORMS WITH DAMAGING WIND GUSTS AND ISOLATED
TORNADOES ARE A THREAT TODAY AS A STRONG STRONG STORM SYSTEM MOVES
ACROSS THE STATE. AT 3 AM THE UPPER LOW WAS LOCATED NEAR THE BIG
BEND AND A LARGE AREA OF THUNDERSTORMS WAS ALREADY AFFECTING THE
HILL COUNTRY. SE TX WAS UNDER THE STRONG INFLOW INTO THE SYSTEM
AND THE AIR MASS OVERHEAD WILL CONTINUE TO DESTABILIZE THIS
MORNING. THE STORM PREDICTION CENTER HAS ALREADY ISSUED A TORNADO
WATCH FOR MOST OF THE FORECAST AREA THROUGH 11 AM. AM EXPECTING
THAT THUNDERSTORMS WILL BEGIN AFFECTING LOCATIONS ALONG AND WEST
OF A LINE FROM COLLEGE STATION TO COLUMBUS BETWEEN 4 AND 6 AM...
AND THEN THE REMAINING AREAS ALONG AND WEST OF INTERSTATE 45 BY
MID MORNING.
THE MODELS WERE SIMILAR IN HOW THEY HANDLED THE MOVEMENT OF THE
UPPER LOW AND SURFACE FEATURES. EXPECT THE UPPER LOW TO SWING
EASTWARD THROUGH THE BIG BEND AREA THIS MORNING BEFORE HEADING TO
THE NORTHEAST THROUGH CENTRAL TEXAS TONIGHT. THE SURFACE FRONT
WILL BE RATHER SLOW TO MOVE EASTWARD AND LOCALLY HEAVY RAINFALL
IS LIKELY. THE PW/S REACH TO 1.7 INCHES...THE MAXIMUM HISTORICALLY
FOR THE END OF JANUARY AND ABOVE 2 STANDARD DEVIATIONS FROM
NORMAL. WILL WATCH THE MOVEMENT OF THE AREA OF THUNDERSTORMS
PUSHING EAST OF INTERSTATE 35 TO SEE IF ANY TRAINING OF STORMS
DEVELOP. MAY CONSIDER A FLOOD WATCH LATER THIS MORNING FOR THE
WESTERN COUNTIES OF THE FORECAST AREA IF THE LINE DOES NOT BEGIN
TO MOVE FASTER TO THE EAST.
THE COLD FRONT WILL BE A BIT SLOWER TO EXIT THROUGH SE TX THAN
EARLIER THOUGHT. THE CHANCES FOR STRONGER THUNDERSTORMS WITH
LOCALLY HEAVY RAINFALL WILL LINGER INTO THE MID AND LATE AFTERNOON
FOR LOCATIONS EAST OF INTERSTATE 45. WRAP AROUND MOISTURE WILL
THEN AFFECT THE FORECAST AREA TONIGHT AND THURSDAY AS THE UPPER
LOW MOVES ACROSS CENTRAL AND NORTH TEXAS.
FAIR AND COOLER WEATHER IS THEN IN STORE FOR THE REST OF THE
PERIOD. ANOTHER WEAK FRONT MOVES THROUGH ON SUNDAY BUT IT APPEARS
TO BE DRY FOR NOW AND WILL JUST REINFORCE THE COOL AND DRY AIR
OVERHEAD.
40
MARINE...
SMALL CRAFT ADVISORY IN EFFECT FOR ALL WATERS AS AN APPROACHING
STORM SYSTEM WILL INTRODUCE SOUTH-TO-NORTH MOVING BANDS OF HEAVY
RAINFALL AND STRONG THUNDERSTORMS WITHIN POCKETS OF RAIN SHOWERS.
ROBUST ONSHORE WINDS JUST UPSTREAM OF THE SURFACE TROUGH...WEAKENING
AS THE TROUGH NEARS AND PASSES EAST...THEN TURNING MODERATE OFFSHORE
LATTER THURSDAY WITHIN A TIGHT BACKSIDE GRADIENT. LOCAL BAY WATERS
WILL BE CHURNED UP WITH NEARSHORE 4 TO 5 FOOT SEA HEIGHTS...AS HIGH
AS 7 TO 8 FEET (WITH A SHORTER PERIOD) FURTHER OFFSHORE. IN THE
MEANTIME...MARINERS SHOULD CLOSELY MONITOR THE RADAR AND CURRENT
OBSERVATIONS THROUGH THE DAY AS WEATHER COULD QUICKLY TURN ROUGH
WITH ANY PASSING MARITIME STORM. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 68 48 60 42 63 / 90 30 30 10 10
HOUSTON (IAH) 74 52 63 45 65 / 80 40 20 10 10
GALVESTON (GLS) 72 55 64 50 62 / 80 50 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
JACKSON...LIBERTY...MADISON...MATAGORDA...MONTGOMERY...SAN
JACINTO...WALKER...WALLER...WASHINGTON...WHARTON.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
634 AM CST WED JAN 25 2012
AVIATION...
MAIN AVIATION CONCERN WILL BE PERIODS OF HEAVY RAINFALL LIMITING
VISBIES (MVFR) AND WIND GUSTS THAT COULD EXCEED 35 KTS WITHIN STRONGEST
STORMS. IN THE MEANTIME...A 50 KT LL JET HAS SHORT TERM WIND SHEAR
IN CURRENT PACKAGE...OR BEFORE THUNDERSTORMS ARRIVE. TIMING HAS THE
BULK OF CONVECTION OVER THE GREATER HOUSTON TERMINALS DURING THE
16-20Z TIME FRAME...PERIODS OF SCATTERED SHOWERS WITH AN EMBEDDED
STORM BOOK-ENDING THOSE TIMES. PRECIP BEGINNING TO FILL IN NICELY
AHEAD OF ONE-OF-TWO MAIN SQUALL LINES MOVING NE FROM SOUTH CENTRAL
TEXAS. THIS 50 KT LOW LEVEL JET AND AMPLE INFLOW INTO THE APPROACHING
MID-SURFACE LOW (NEAR KSAT) WILL AID IN KEEPING THE MAJORITY OF
THE DECKS AT IFR OR MVFR LEVELS...MORNING 20-25 SUSTAINED WINDS.
LINGERING -SHRA THROUGH EVENING AS THE SURFACE LOW PASSES EAST...WRAP
AROUND -RA THROUGH LATE EVENING WITH OVERCAST DECKS THROUGH REMAINDER
OF PERIOD UNDER WESTERLY FLOW. 31
&&
PREV DISCUSSION... /ISSUED 540 AM CST WED JAN 25 2012/
UPDATE...
UPDATE FOR STRONGER WINDS THAN EARLIER EXPECTED. SUSTAINED 20 TO
25 MPH HAVE DEVELOPED AHEAD OF THE STORMS MOVING TOWARD THE
WESTERN COUNTIES OF THE FORECAST AREA. 09Z RUC INITIALIZED WELL
WITH THE WINDS. THE STRONGER WINDS WILL DIMINISH BY MIDDAY. WIND
ADVISORY OUT THROUGH NOON.
40
PREV DISCUSSION... /ISSUED 422 AM CST WED JAN 25 2012/
DISCUSSION...
SEVERE THUNDERSTORMS WITH DAMAGING WIND GUSTS AND ISOLATED
TORNADOES ARE A THREAT TODAY AS A STRONG STRONG STORM SYSTEM MOVES
ACROSS THE STATE. AT 3 AM THE UPPER LOW WAS LOCATED NEAR THE BIG
BEND AND A LARGE AREA OF THUNDERSTORMS WAS ALREADY AFFECTING THE
HILL COUNTRY. SE TX WAS UNDER THE STRONG INFLOW INTO THE SYSTEM
AND THE AIR MASS OVERHEAD WILL CONTINUE TO DESTABILIZE THIS
MORNING. THE STORM PREDICTION CENTER HAS ALREADY ISSUED A TORNADO
WATCH FOR MOST OF THE FORECAST AREA THROUGH 11 AM. AM EXPECTING
THAT THUNDERSTORMS WILL BEGIN AFFECTING LOCATIONS ALONG AND WEST
OF A LINE FROM COLLEGE STATION TO COLUMBUS BETWEEN 4 AND 6 AM...
AND THEN THE REMAINING AREAS ALONG AND WEST OF INTERSTATE 45 BY
MID MORNING.
THE MODELS WERE SIMILAR IN HOW THEY HANDLED THE MOVEMENT OF THE
UPPER LOW AND SURFACE FEATURES. EXPECT THE UPPER LOW TO SWING
EASTWARD THROUGH THE BIG BEND AREA THIS MORNING BEFORE HEADING TO
THE NORTHEAST THROUGH CENTRAL TEXAS TONIGHT. THE SURFACE FRONT
WILL BE RATHER SLOW TO MOVE EASTWARD AND LOCALLY HEAVY RAINFALL
IS LIKELY. THE PW/S REACH TO 1.7 INCHES...THE MAXIMUM HISTORICALLY
FOR THE END OF JANUARY AND ABOVE 2 STANDARD DEVIATIONS FROM
NORMAL. WILL WATCH THE MOVEMENT OF THE AREA OF THUNDERSTORMS
PUSHING EAST OF INTERSTATE 35 TO SEE IF ANY TRAINING OF STORMS
DEVELOP. MAY CONSIDER A FLOOD WATCH LATER THIS MORNING FOR THE
WESTERN COUNTIES OF THE FORECAST AREA IF THE LINE DOES NOT BEGIN
TO MOVE FASTER TO THE EAST.
THE COLD FRONT WILL BE A BIT SLOWER TO EXIT THROUGH SE TX THAN
EARLIER THOUGHT. THE CHANCES FOR STRONGER THUNDERSTORMS WITH
LOCALLY HEAVY RAINFALL WILL LINGER INTO THE MID AND LATE AFTERNOON
FOR LOCATIONS EAST OF INTERSTATE 45. WRAP AROUND MOISTURE WILL
THEN AFFECT THE FORECAST AREA TONIGHT AND THURSDAY AS THE UPPER
LOW MOVES ACROSS CENTRAL AND NORTH TEXAS.
FAIR AND COOLER WEATHER IS THEN IN STORE FOR THE REST OF THE
PERIOD. ANOTHER WEAK FRONT MOVES THROUGH ON SUNDAY BUT IT APPEARS
TO BE DRY FOR NOW AND WILL JUST REINFORCE THE COOL AND DRY AIR
OVERHEAD.
40
MARINE...
SMALL CRAFT ADVISORY IN EFFECT FOR ALL WATERS AS AN APPROACHING
STORM SYSTEM WILL INTRODUCE SOUTH-TO-NORTH MOVING BANDS OF HEAVY
RAINFALL AND STRONG THUNDERSTORMS WITHIN POCKETS OF RAIN SHOWERS.
ROBUST ONSHORE WINDS JUST UPSTREAM OF THE SURFACE TROUGH...WEAKENING
AS THE TROUGH NEARS AND PASSES EAST...THEN TURNING MODERATE OFFSHORE
LATTER THURSDAY WITHIN A TIGHT BACKSIDE GRADIENT. LOCAL BAY WATERS
WILL BE CHURNED UP WITH NEARSHORE 4 TO 5 FOOT SEA HEIGHTS...AS HIGH
AS 7 TO 8 FEET (WITH A SHORTER PERIOD) FURTHER OFFSHORE. IN THE
MEANTIME...MARINERS SHOULD CLOSELY MONITOR THE RADAR AND CURRENT
OBSERVATIONS THROUGH THE DAY AS WEATHER COULD QUICKLY TURN ROUGH
WITH ANY PASSING MARITIME STORM. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 68 48 60 42 63 / 90 30 30 10 10
HOUSTON (IAH) 74 52 63 45 65 / 80 40 20 10 10
GALVESTON (GLS) 72 55 64 50 62 / 80 50 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
JACKSON...LIBERTY...MADISON...MATAGORDA...MONTGOMERY...SAN
JACINTO...WALKER...WALLER...WASHINGTON...WHARTON.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
556 AM CST WED JAN 25 2012
.AVIATION...
MAIN AVIATION CONCERN WILL BE PERIODS OF HEAVY RAINFALL LIMITING
VISBIES INTO MVFR...WIND GUSTS THAT COULD EXCEED 30-35 KTS IN
STRONGEST STORMS. TIMING HAS THE BULK OF CONVECTION ACROSS METRO
DURING THE 16-20Z TIME FRAME...PERIODS OF SCATTERED SHOWERS WITH
AN EMBEDDED STORM BOOKENDING THOSE TIMES. PRECIP BEGINNING TO FILL
IN NICELY AHEAD OF ONE-OF-TWO MAIN SQUALL LINES PASSING OUT OF
SOUTH CENTRAL TEXAS THIS HOUR. A STRONG LOW LEVEL 45-50 KT JET AND
AMPLE INFLOW INTO THE APPROACHING MID-SURFACE LOW WILL AID IN KEEPING
THE MAJORITY OF THE DECKS AT IFR OR MVFR LEVELS. LINGERING -SHRA
THROUGH EVENING AS THE SURFACE LOW PASSES EAST...WRAP AROUND PRECIP
THROUGH LATE EVENING WITH OVERCAST DECKS THROUGH REMAINDER OF PERIOD
UNDER WESTERLY FLOW. 31
&&
.PREV DISCUSSION... /ISSUED 540 AM CST WED JAN 25 2012/
UPDATE...
UPDATE FOR STRONGER WINDS THAN EARLIER EXPECTED. SUSTAINED 20 TO
25 MPH HAVE DEVELOPED AHEAD OF THE STORMS MOVING TOWARD THE
WESTERN COUNTIES OF THE FORECAST AREA. 09Z RUC INITIALIZED WELL
WITH THE WINDS. THE STRONGER WINDS WILL DIMINISH BY MIDDAY. WIND
ADVISORY OUT THROUGH NOON.
40
PREV DISCUSSION... /ISSUED 422 AM CST WED JAN 25 2012/
DISCUSSION...
SEVERE THUNDERSTORMS WITH DAMAGING WIND GUSTS AND ISOLATED
TORNADOES ARE A THREAT TODAY AS A STRONG STRONG STORM SYSTEM MOVES
ACROSS THE STATE. AT 3 AM THE UPPER LOW WAS LOCATED NEAR THE BIG
BEND AND A LARGE AREA OF THUNDERSTORMS WAS ALREADY AFFECTING THE
HILL COUNTRY. SE TX WAS UNDER THE STRONG INFLOW INTO THE SYSTEM
AND THE AIR MASS OVERHEAD WILL CONTINUE TO DESTABILIZE THIS
MORNING. THE STORM PREDICTION CENTER HAS ALREADY ISSUED A TORNADO
WATCH FOR MOST OF THE FORECAST AREA THROUGH 11 AM. AM EXPECTING
THAT THUNDERSTORMS WILL BEGIN AFFECTING LOCATIONS ALONG AND WEST
OF A LINE FROM COLLEGE STATION TO COLUMBUS BETWEEN 4 AND 6 AM...
AND THEN THE REMAINING AREAS ALONG AND WEST OF INTERSTATE 45 BY
MID MORNING.
THE MODELS WERE SIMILAR IN HOW THEY HANDLED THE MOVEMENT OF THE
UPPER LOW AND SURFACE FEATURES. EXPECT THE UPPER LOW TO SWING
EASTWARD THROUGH THE BIG BEND AREA THIS MORNING BEFORE HEADING TO
THE NORTHEAST THROUGH CENTRAL TEXAS TONIGHT. THE SURFACE FRONT
WILL BE RATHER SLOW TO MOVE EASTWARD AND LOCALLY HEAVY RAINFALL
IS LIKELY. THE PW/S REACH TO 1.7 INCHES...THE MAXIMUM HISTORICALLY
FOR THE END OF JANUARY AND ABOVE 2 STANDARD DEVIATIONS FROM
NORMAL. WILL WATCH THE MOVEMENT OF THE AREA OF THUNDERSTORMS
PUSHING EAST OF INTERSTATE 35 TO SEE IF ANY TRAINING OF STORMS
DEVELOP. MAY CONSIDER A FLOOD WATCH LATER THIS MORNING FOR THE
WESTERN COUNTIES OF THE FORECAST AREA IF THE LINE DOES NOT BEGIN
TO MOVE FASTER TO THE EAST.
THE COLD FRONT WILL BE A BIT SLOWER TO EXIT THROUGH SE TX THAN
EARLIER THOUGHT. THE CHANCES FOR STRONGER THUNDERSTORMS WITH
LOCALLY HEAVY RAINFALL WILL LINGER INTO THE MID AND LATE AFTERNOON
FOR LOCATIONS EAST OF INTERSTATE 45. WRAP AROUND MOISTURE WILL
THEN AFFECT THE FORECAST AREA TONIGHT AND THURSDAY AS THE UPPER
LOW MOVES ACROSS CENTRAL AND NORTH TEXAS.
FAIR AND COOLER WEATHER IS THEN IN STORE FOR THE REST OF THE
PERIOD. ANOTHER WEAK FRONT MOVES THROUGH ON SUNDAY BUT IT APPEARS
TO BE DRY FOR NOW AND WILL JUST REINFORCE THE COOL AND DRY AIR
OVERHEAD.
40
MARINE...
SMALL CRAFT ADVISORY IN EFFECT FOR ALL WATERS AS AN APPROACHING
STORM SYSTEM WILL INTRODUCE SOUTH-TO-NORTH MOVING BANDS OF HEAVY
RAINFALL AND STRONG THUNDERSTORMS WITHIN POCKETS OF RAIN SHOWERS.
ROBUST ONSHORE WINDS JUST UPSTREAM OF THE SURFACE TROUGH...WEAKENING
AS THE TROUGH NEARS AND PASSES EAST...THEN TURNING MODERATE OFFSHORE
LATTER THURSDAY WITHIN A TIGHT BACKSIDE GRADIENT. LOCAL BAY WATERS
WILL BE CHURNED UP WITH NEARSHORE 4 TO 5 FOOT SEA HEIGHTS...AS HIGH
AS 7 TO 8 FEET (WITH A SHORTER PERIOD) FURTHER OFFSHORE. IN THE
MEANTIME...MARINERS SHOULD CLOSELY MONITOR THE RADAR AND CURRENT
OBSERVATIONS THROUGH THE DAY AS WEATHER COULD QUICKLY TURN ROUGH
WITH ANY PASSING MARITIME STORM. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 68 48 60 42 63 / 90 30 30 10 10
HOUSTON (IAH) 74 52 63 45 65 / 80 40 20 10 10
GALVESTON (GLS) 72 55 64 50 62 / 80 50 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
JACKSON...LIBERTY...MADISON...MATAGORDA...MONTGOMERY...SAN
JACINTO...WALKER...WALLER...WASHINGTON...WHARTON.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
540 AM CST WED JAN 25 2012
.UPDATE...
UPDATE FOR STRONGER WINDS THAN EARLIER EXPECTED. SUSTAINED 20 TO
25 MPH HAVE DEVELOPED AHEAD OF THE STORMS MOVING TOWARD THE
WESTERN COUNTIES OF THE FORECAST AREA. 09Z RUC INITIALIZED WELL
WITH THE WINDS. THE STRONGER WINDS WILL DIMINISH BY MIDDAY. WIND
ADVISORY OUT THROUGH NOON.
40
&&
.PREV DISCUSSION... /ISSUED 422 AM CST WED JAN 25 2012/
DISCUSSION...
SEVERE THUNDERSTORMS WITH DAMAGING WIND GUSTS AND ISOLATED
TORNADOES ARE A THREAT TODAY AS A STRONG STRONG STORM SYSTEM MOVES
ACROSS THE STATE. AT 3 AM THE UPPER LOW WAS LOCATED NEAR THE BIG
BEND AND A LARGE AREA OF THUNDERSTORMS WAS ALREADY AFFECTING THE
HILL COUNTRY. SE TX WAS UNDER THE STRONG INFLOW INTO THE SYSTEM
AND THE AIR MASS OVERHEAD WILL CONTINUE TO DESTABILIZE THIS
MORNING. THE STORM PREDICTION CENTER HAS ALREADY ISSUED A TORNADO
WATCH FOR MOST OF THE FORECAST AREA THROUGH 11 AM. AM EXPECTING
THAT THUNDERSTORMS WILL BEGIN AFFECTING LOCATIONS ALONG AND WEST
OF A LINE FROM COLLEGE STATION TO COLUMBUS BETWEEN 4 AND 6 AM...
AND THEN THE REMAINING AREAS ALONG AND WEST OF INTERSTATE 45 BY
MID MORNING.
THE MODELS WERE SIMILAR IN HOW THEY HANDLED THE MOVEMENT OF THE
UPPER LOW AND SURFACE FEATURES. EXPECT THE UPPER LOW TO SWING
EASTWARD THROUGH THE BIG BEND AREA THIS MORNING BEFORE HEADING TO
THE NORTHEAST THROUGH CENTRAL TEXAS TONIGHT. THE SURFACE FRONT
WILL BE RATHER SLOW TO MOVE EASTWARD AND LOCALLY HEAVY RAINFALL
IS LIKELY. THE PW/S REACH TO 1.7 INCHES...THE MAXIMUM HISTORICALLY
FOR THE END OF JANUARY AND ABOVE 2 STANDARD DEVIATIONS FROM
NORMAL. WILL WATCH THE MOVEMENT OF THE AREA OF THUNDERSTORMS
PUSHING EAST OF INTERSTATE 35 TO SEE IF ANY TRAINING OF STORMS
DEVELOP. MAY CONSIDER A FLOOD WATCH LATER THIS MORNING FOR THE
WESTERN COUNTIES OF THE FORECAST AREA IF THE LINE DOES NOT BEGIN
TO MOVE FASTER TO THE EAST.
THE COLD FRONT WILL BE A BIT SLOWER TO EXIT THROUGH SE TX THAN
EARLIER THOUGHT. THE CHANCES FOR STRONGER THUNDERSTORMS WITH
LOCALLY HEAVY RAINFALL WILL LINGER INTO THE MID AND LATE AFTERNOON
FOR LOCATIONS EAST OF INTERSTATE 45. WRAP AROUND MOISTURE WILL
THEN AFFECT THE FORECAST AREA TONIGHT AND THURSDAY AS THE UPPER
LOW MOVES ACROSS CENTRAL AND NORTH TEXAS.
FAIR AND COOLER WEATHER IS THEN IN STORE FOR THE REST OF THE
PERIOD. ANOTHER WEAK FRONT MOVES THROUGH ON SUNDAY BUT IT APPEARS
TO BE DRY FOR NOW AND WILL JUST REINFORCE THE COOL AND DRY AIR
OVERHEAD.
40
MARINE...
SMALL CRAFT ADVISORY IN EFFECT FOR ALL WATERS AS AN APPROACHING
STORM SYSTEM WILL INTRODUCE SOUTH-TO-NORTH MOVING BANDS OF HEAVY
RAINFALL AND STRONG THUNDERSTORMS WITHIN POCKETS OF RAIN SHOWERS.
ROBUST ONSHORE WINDS JUST UPSTREAM OF THE SURFACE TROUGH...WEAKENING
AS THE TROUGH NEARS AND PASSES EAST...THEN TURNING MODERATE OFFSHORE
LATTER THURSDAY WITHIN A TIGHT BACKSIDE GRADIENT. LOCAL BAY WATERS
WILL BE CHURNED UP WITH NEARSHORE 4 TO 5 FOOT SEA HEIGHTS...AS HIGH
AS 7 TO 8 FEET (WITH A SHORTER PERIOD) FURTHER OFFSHORE. IN THE
MEANTIME...MARINERS SHOULD CLOSELY MONITOR THE RADAR AND CURRENT
OBSERVATIONS THROUGH THE DAY AS WEATHER COULD QUICKLY TURN ROUGH
WITH ANY PASSING MARITIME STORM. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 68 48 60 42 63 / 90 30 30 10 10
HOUSTON (IAH) 74 52 63 45 65 / 80 40 20 10 10
GALVESTON (GLS) 72 55 64 50 62 / 80 50 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
JACKSON...LIBERTY...MADISON...MATAGORDA...MONTGOMERY...SAN
JACINTO...WALKER...WALLER...WASHINGTON...WHARTON.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...40
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
520 AM CST WED JAN 25 2012
.SHORT TERM...TODAY THROUGH FRIDAY
318 AM CST WED JAN 25 2012
MAIN FORECAST CONCERNS INCLUDE SNOW CHANCES TODAY...AND THEN
TEMPERATURES THROUGH THE SHORT TERM.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MID-LEVEL TROUGH
EXTENDING FROM EASTERN ND THROUGH NEBRASKA. ISENTROPIC LIFT AHEAD OF
THIS TROUGH WAS PRODUCING AREAS OF LIGHT SNOW ACROSS PORTIONS OF
SOUTHERN MN INTO WEST-CENTRAL AND NORTHWEST WI PER THE RADAR
MOSAIC/SURFACE OBSERVATIONS. MOST OF THIS WAS VERY LIGHT SNOW WITH
VISIBILITIES IN THE 7-10SM RANGE...BUT THERE WERE POCKETS OF 1-2SM
-SN WHERE THERE WAS MORE VIGOROUS SATURATION OF THE COLUMN.
OTHERWISE...WITH CLOUDS AND WEAK SOUTHERLY SURFACE FLOW...
TEMPERATURES AT 3 AM WERE IN THE UPPER TEENS TO LOWER 20S.
25.00Z NAM/GFS AS WELL AS THE 25.03Z SREF ALL IN GOOD AGREEMENT WITH
OVERALL UPPER LEVEL/SURFACE FEATURES THROUGH THE SHORT TERM.
FOR TODAY...MODELS CONTINUE TO SHOW ISENTROPIC LIFT THROUGH THIS
MORNING ALONG AND NORTH OF I-90 THROUGH THIS MORNING...THEN SHIFTS
NORTH OUT OF THE AREA BY THIS AFTERNOON AS THE MID-LEVEL TROUGH
BEGINS TO FILL/WEAKEN AS IT MOVES THROUGH. AS SUCH...WILL CONTINUE
-SN CHANCES MAINLY ALONG/NORTH OF I-90 THIS MORNING...THEN WILL GO
DRY THIS AFTERNOON. ANY SNOWFALL EXPECTED TO BE MINIMAL WITH PERHAPS
A TENTH OF AN INCH OR TWO TENTHS AT MOST. MOSTLY CLOUDY CONDITIONS
EXPECTED THROUGH THE REMAINDER OF THE DAY WITH PERHAPS SOME CLEARING
ACROSS THE SOUTH LATE IN THE AFTERNOON. OTHERWISE...AFTER A
RELATIVELY WARMER START THIS MORNING...HIGHS TODAY SHOULD TOP OF IN
THE LOWER 30S.
MILDER TEMPERATURES EXPECTED THROUGH THURSDAY IN WARM AIR ADVECTION
AHEAD OF A DEEP LOW PRESSURE SYSTEM MOVING THROUGH CENTRAL CANADA.
NAM INDICATING 925MB TEMPERATURES WARMING TO 0-5C THROUGH MIDDAY
THURSDAY. A COLD FRONT WILL THEN BE MOVING INTO THE AREA BY
MIDDAY...BUT BULK OF THE COLD AIR ADVECTION LOOKS LIKE IT WILL
FOLLOW NORMAL MID-LATE AFTERNOON DIURNAL T-CURVE DOWNSWING. SO
EXPECTING HIGHS THROUGH ABOUT MIDDAY...THEN FALLING THROUGH THE
AFTERNOON. BOTTOM LINE...LOOKS LIKE HIGHS THURSDAY SHOULD TOP OFF IN
THE MID-UPPER 30S.
SKIES EXPECTED TO CLEAR THROUGH MIDNIGHT ACROSS THE AREA THROUGH
THURSDAY EVENING WITH JUST A BRIEF SHOT OF COLD AIR ADVECTION MAINLY
EAST OF THE MISSISSIPPI RIVER. AFTER 06Z THURSDAY...BUFKIT SOUNDINGS
SHOW INCREASING MID/HIGH LEVEL CLOUDS MOVING IN MAINLY WEST OF THE
MISSISSIPPI RIVER IN ADVANCE OF A WEAK MID-LEVEL TROUGH/SURFACE LOW
PRESSURE MOVING ACROSS THE NORTHERN PLAINS.
ON FRIDAY...WILL CONTINUE TO SEE THAT WEAK MID-LEVEL TROUGH/SURFACE
LOW RIPPLE SOUTHEAST ACROSS IA INTO NORTHERN IL. BUFKIT COMPARISONS
OF THE GFS/NAM SHOW DIFFERING OPINIONS ON DEGREE OF COLUMN
SATURATION. THE GFS AT THIS POINT IS A BIT DRIER IN THE LOWER LEVELS
WHEREAS THE NAM WANTS TO SATURATE/PRECIPITATE MAINLY ALONG AND SOUTH
OF I-94. FOR NOW WILL CARRY 30 POPS FOR THIS AREA.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY
318 AM CST WED JAN 25 2012
25.00Z GFS/ECMWF BOTH SHOW COLD AIR ADVECTION WITH DEEPENING MID-
LEVEL TROUGH DROPPING INTO THE REGION FRIDAY NIGHT THROUGH SATURDAY
FOR A CHANCE OF -SN. HIGHS SATURDAY EXPECTED TO FALL BACK TO NEAR
NORMAL LEVELS IN THE MID/UPPER 20S. SURFACE RIDGE OF HIGH PRESSURE
SLIDES ACROSS THE AREA ON SUNDAY FOR MOSTLY SUNNY SKIES...BUT HIGHS
ONLY EXPECTED TO TOP OFF IN THE TEENS TO LOWER 20S. MODERATING
TEMPERATURES THEN EXPECTED MONDAY AS A WEAK LOW AND WARM FRONT PUSH
OUT OF THE NORTHERN PLAINS INTO THE UPPER MISSISSIPPI RIVER REGION.
ISENTROPIC LIFT AHEAD OF THE LOW AND WARM FRONT WILL PRODUCE A
SLIGHT CHANCE OF -SN. OTHERWISE...LOOKING FOR HIGHS PUSHING INTO THE
MID 20S TO LOWER 30S. ON TUESDAY...THE WARM FRONT LOOKS TO LINGER
ACROSS THE AREA FOR A CHANCE OF RAIN OR SNOW AS HIGHS TOP OFF IN THE
30S.
&&
.AVIATION...
520 AM CST WED JAN 25 2012
LIGHT SN ACROSS THE REGION IN RESPONSE TO AN UPPER LEVEL SHORTWAVE
TROUGH MOVING EAST ACROSS THE REGION. SATURATION IS A BIG ISSUE FOR
-SN CHANCES AND DRY AIR TO THE SOUTH PROGGED TO ADVANCE NORTH AS THE
MORNING WEARS ON. EXPECT AREAS OF -SN TO DIMINISH AS A RESULT...AND
CIGS SHOULD BE KEPT VFR AT KRST/KLSE. WILL KEEP ANY -SN OUT OF THE
TAFS.
SOUTH WINDS WILL BE ON THE INCREASE TONIGHT...AND SOME CONCERN THAT
THIS WILL ADVECT IN SOME LOWER SATURATION AND LOW CIGS. SNOW PACK TO
THE SOUTH...AND SNOW TEMPS...SUGGEST THAT A STRONG SOUTHERLY FETCH
COULD LEAD TO NEAR SFC SATURATION AND THE POTENTIAL FOR LOW STRATUS.
CONFIDENCE NOT HIGH ENOUGH TO ADD MENTION TO THE TAFS AT THIS
TIME...BUT THIS POTENTIAL WILL HAVE TO BE MONITORED.
ANOTHER SHORTWAVE TROUGH WILL SWEEP MORE CLOUDS INTO THE REGION BY
THU MORNING...BUT ANY CEILINGS LOOK TO BE VFR AT THIS TIME. WINDS
WILL STAY BLUSTERY AND POTENTIALLY GUSTY...ESPECIALLY IN A 06-18Z
THU TIME FRAME. LOOK FOR A SWING TO WEST/NORTHWEST THU MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
318 AM CST WED JAN 25 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... DAS
LONG TERM.... DAS
AVIATION..... RIECK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
330 PM EST WED JAN 25 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHEAST ALONG A WARM FRONT INTO THE
OHIO VALLEY TONIGHT. A STRONGER UPPER LOW WILL THEN PASS THROUGH
THE TENNESSEE VALLEY ON THURSDAY ACCOMPANIED BY A TROUGH OF LOW
PRESSURE ALOFT. AS THIS UPPER SYSTEM DEPARTS ON THURSDAY
NIGHT...THE FRONTAL BOUNDARY TO THE SOUTH AND EAST OF INDIANA WILL
PUSH EAST AS A COLD FRONT. AFTERWARD DRY...NORTHWEST FLOW OF
CANADIAN AIR WILL BEGIN ACROSS CENTRAL INDIANA. HIGH PRESSURE WILL
RETURN TO THE STATE ON FRIDAY BRINGING DRY WEATHER BACK TO THE
STATE FOR THE WEEKEND AND INTO EARLY NEXT WEEK. THE NEXT SYSTEM TO
IMPACT THE REGION WILL ARRIVE NEXT TUESDAY INTO TUESDAY NIGHT.
&&
.NEAR TERM /REST OF TODAY/...
MAIN FORECAST CONCERN TODAY IS PRECIPITATION AND TEMPERATURE
TREND... MOREOVER WHAT PRECIP TYPES WILL IMPACT THE AREA WITH
APPROACHING SURFACE LOW TO THE SOUTHWEST. UPON A COMPARISON WITH
CURRENT OBSERVATIONS... THE NAM HAS A GOOD HANDLE ON SURFACE
FEATURES AND BOTH NAM AND RUC HAVE THE BEST HANDLE ON SURFACE TEMPS
SO FAR. SHORT RANGE ENSEMBLE GUIDANCE GOES A BIT WARM KEEPING NEARLY
ALL OF THE FORECAST AREA ABOVE FREEZING WHEN THE PRECIPITATION
OCCURS. CURRENT THINKING WEIGHS IN MORE ON THE NAM AND RUC WITH
KEEPING NEAR TO SLIGHTLY BELOW FREEZING TEMPS ACROSS THE NORTHERN
THIRD OF THE FORECAST AREA.
THE NORTHERN MAJORITY OF THE AREA HAS BEEN TRENDING A FEW DEGREES
ABOVE PREVIOUS FORECAST... HOWEVER CONSIDERING EVAPORATIONAL COOLING
WITH ONSET OF PRECIP... THE TEMPS WILL LIKELY STAY STEADY OR ONLY
INCREASE BY A FEW DEGREES. THIS WILL KEEP THE NORTHERN HALF OF THE
FORECAST AREA AT 31 TO 33 DEGREES THRU 00Z. MAX TEMPS IN THE SOUTH
WILL LIKELY GET TO THE MID 30S.
FOR PRECIP TIMING AND AMOUNT... SHORT RANGE GUIDANCE IS IN GOOD
AGREEMENT WITH ONSET OF PRECIP OCCURRING FROM THE SOUTHWEST STARTING
NEAR 18Z AND SPREADING NORTHEASTWARD ACROSS THE MAJORITY OF THE
FORECAST AREA BY 00Z. QPF LOOKS TO BE LIGHT WITH A FEW HUNDREDTHS IN
THE NORTH TO NEAR A TENTH OF AN INCH IN THE SOUTHWEST... WHERE MORE
RAIN SHOWERS WILL HAVE OCCURRED.
CONSIDERING THE ABOVE ALONG WITH FORECAST SOUNDING DATA AND THE
DEPTH OF THE WARM NOSE IN THE SATURATED COLUMN... PRECIP MAY START
OUT AS A BRIEF PERIOD OF LIGHT SLEET OR FREEZING DRIZZLE... BUT THEN
LIKELY TRANSITION TO LIGHT RAIN SHOWERS AND DRIZZLE AS WARM
ADVECTION AHEAD OF THE APPROACHING LOW BATTLES AGAINST THE LOW LEVEL
INVERSION.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
WARM FRONT WILL BE SET UP ALONG THE OHIO RIVER TONIGHT AS PREVIOUSLY
DISCUSSED ISENTROPIC LIFT AND MOISTURE CONTINUES. UPPER SUPPORT
REMAINS QUITE FAVORABLE TONIGHT AS A SHORT WAVE IS EXPECTED TOWARD
INDIANA FROM THE MAIN LOW. FURTHERMORE IN THE LOWER LEVELS MILD
AND MOIST GULF AIR CONTINUES TO STREAM INTO THE OHIO VALLEY. RAIN IS
EXPECTED TO REMAIN ACROSS THE AREA INTO THE EVENING HOURS. TIME
HEIGHTS AND FORECAST SOUNDINGS INDICATE SATURATION INTO THE
EVENINGS HOURS AS WELL. THUS WILL AGAIN USE WETTER POPS TONIGHT.
GIVEN THE EXPECTED CLOUDS AND RAIN WILL TREND TONIGHTS LOWS
WARMER THAN MAVMOS. SOME COOLER AIR AT THE SURFACE ACROSS THE
NORTHERN PARTS OF THE FORECAST AREA...LAFAYETTE...KOKOMO...MAY
RESULT IN SOME SNOW BEING MIXED IN AT THOSE LOCATIONS. ALTHOUGH
ACCUMULATIONS WOULD BE MINIMAL TO NONE.
MORE RAIN WILL BE EXPECTED ON THURSDAY AS THE UPPER LOW OVER THE
SOUTHERN PLAINS AND A TROUGH OF LOW PRESSURE ALOFT PUSH ACROSS THE
REGION PROVIDING AMPLE LIFT. FORECAST SOUNDINGS CONTINUE TO
INDICATE DEEP SATURATION AND KEEP THE LOWEST LEVELS OF THE
ATMOSPHERE ABOVE FREEZING. AGAIN WILL TREND HIGHER THAN MAVMOS
POPS ON THURSDAY AND COOLER ON HIGH TEMPERATURES GIVEN THE
EXPECTED RAIN.
UPPER SUPPORT FINALLY EXITS THE AREA TO THE EAST ON THURSDAY
NIGHT INTO FRIDAY MORNING AS A COOLER NORTHWEST FLOW BEGINS TO
TAKE SHAPE. FORECAST SOUNDINGS SHOW SIGNIFICANT DRYING AFTER 00Z
FRIDAY AS STRONG SUBSIDENCE TAKES SHAPE. 850MB SURFACE SHOWS
STRONG COLD AIR ADVECTION ACROSS THE AREA AS THEY FALL TO THE NEAR
-2C BY 12Z FRI. FORECAST SOUNDINGS ALSO DO NOT HINT AT LINGERING
STRATOCU AS STRONG SURFACE RIDGING BUILDS ACROSS THE AREA ON
THURSDAY NIGHT. THUS WILL TREND TOWARD BECOMING CLEAR ALONG WITH
LOWS ON THURSDAY NIGHT COOLER THAN MAVMOS.
DRY WEATHER IS EXPECTED ON FRIDAY AS THE SURFACE RIDGE MOVES
ACROSS THE AREA. THE QUICK NORTHWEST FLOW ALOFT MAY ALLOW FOR SOME
PASSING CLOUDS...BUT FOR NOW PTCLDY WILL WORK FIND ALONG WITH
TEMPS COOLER THAN MAVMOS GIVEN THE 850MB TEMPS.
A WEAK CLIPPER IS THEN EXPECTED TO PUSH THROUGH THE AREA ON FRIDAY
NIGHT. HOWEVER MOISTURE WILL REMAIN A PROBLEM WITH THIS WEAK SYSTEM
AS IT WILL ONLY HAVE PACIFIC MOISTURE TO WORK WITH AND ONLY
MARGINAL SUPPORT ALOFT. FOR NOW WILL TREND TOWARD JUST A MOSTLY
CLOUDY SKY...WITH LOWS COOLER THAN MEXMOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BY THE START OF THE EXTENDED PERIOD ENSEMBLES HAVE THE REGION
ESTABLISHED IN ZONAL FLOW WHICH LASTS THROUGH EARLY NEXT WEEK. A
WEAK UPPER TROUGH SHIFTS THROUGH THE GREAT LAKES REGION SUNDAY INTO
SUNDAY NIGHT BUT THIS FEATURE APPEARS TO STAY FAR NORTHWARD SO AS
NOT TO AFFECT CENTRAL INDIANA. THE FORECAST AREA WILL THEREFORE
REMAIN DRY FOR THE MAJORITY OF THE PERIOD...AND TEMPERATURES WILL
MODERATE BACK TO ABOVE NORMAL BY EARLY NEXT WEEK. ENSEMBLES SUGGEST
THE NEXT UPPER SYSTEM WILL NOT ARRIVE UNTIL TUESDAY INTO TUESDAY
NIGHT...WHICH THEY HAVE BEEN DEPICTING THESE PAST FEW MODEL RUNS.
BUMPED UP CHANCE POPS SLIGHTLY DURING THIS PERIOD TO ACCOUNT FOR
GOOD CONTINUITY AND CONSENSUS THUS FAR. PRECIPITATION TYPE AT THIS
TIME LOOKS TO BE ALL RAIN.
&&
.AVIATION /DISCUSSION FOR THE 252100Z TAFS/...
1945Z UPDATE...ADDED SLEET TO KIND TAF BASED ON REPORTS UPSTREAM.
THIS IS A VERY TRICKY FORECAST SO OPTED TO USE -RAPL FOR NOW UNTIL
03Z. THIS SHOULD NOT HAVE AN IMMEDIATE IMPACT UPON FLIGHT
CATEGORY...HOWEVER THAT SHOULD CHANGE IN A COUPLE OF HOURS.
PREVIOUS DISCUSSION FOLLOWS...
1900Z UPDATE...ADDED -RASN TO KHUF TAF BASED ON OBSERVATIONS
UPSTREAM. THIS SHOULD NOT HAVE AN IMPACT ON THE FLIGHT CATEGORY AT
THIS TIME BUT WILL CONTINUE TO MONITOR FOR FUTURE UPDATES.
PREVIOUS DISCUSSION FOLLOWS...
VERY TRICKY PUBLIC AND AVIATION FORECAST SHAPING UP FOR THE REST
OF TODAY AND TONIGHT. AS TEMPERATURES HOVER AROUND THE FREEZING
MARK THIS HOUR...RAIN IS TRYING TO SPREAD INTO CENTRAL INDIANA
FROM THE SW. AS EXPECTED...CEILINGS ARE GRADUALLY LOWERING AND
WILL CONTINUE THIS TREND UNTIL THEY ARE AT MFVR THIS EVENING WITH
THE CHANCE FOR -RA. WITH SURFACE TEMPS RIGHT AROUND THE FREEZING
MARK...FREEZING RAIN AND EVEN SLEET CANNOT BE RULED OUT AT TIMES
ACROSS THE AREA. BUT FOR NOW BASED ON WARMER TEMP TRENDS (AND
MODEL THICKNESSES) OPTED TO GO WITH JUST -RA THE ENTIRE PERIOD.
DEEPER MOISTURE MOVES INTO THE AREA TONIGHT INTO THURSDAY AND A
PROLONGED PERIOD OF IFR CAN BE EXPECTED AT ALL OF THE TERMINALS
BEGINNING BETWEEN 04-08Z AND LASTING THROUGH ALL OF THU MORNING.
FLIGHT CONDITIONS ARE NOT SET TO IMPROVE AT THE END OF THE TAF
PERIOD...AT BEST ONLY TO LOW END MFVR.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 AM EST THURSDAY FOR INZ021-
028>031-035>049-051-052.
&&
$$
SYNOPSIS...SMF
NEAR TERM...AB/JK
SHORT TERM...PUMA
LONG TERM....SMF
AVIATION...SMF/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
248 PM EST WED JAN 25 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHEAST ALONG A WARM FRONT INTO THE
OHIO VALLEY TONIGHT. A STRONGER UPPER LOW WILL THEN PASS THROUGH
THE TENNESSEE VALLEY ON THURSDAY ACCOMPANIED BY A TROUGH OF LOW
PRESSURE ALOFT. AS THIS UPPER SYSTEM DEPARTS ON THURSDAY
NIGHT...THE FRONTAL BOUNDARY TO THE SOUTH AND EAST OF INDIANA WILL
PUSH EAST AS A COLD FRONT. AFTERWARD DRY...NORTHWEST FLOW OF
CANADIAN AIR WILL BEGIN ACROSS CENTRAL INDIANA. HIGH PRESSURE WILL
RETURN TO THE STATE ON FRIDAY BRINGING DRY WEATHER BACK TO THE
STATE FOR THE WEEKEND AND INTO EARLY NEXT WEEK. THE NEXT SYSTEM TO
IMPACT THE REGION WILL ARRIVE NEXT TUESDAY INTO TUESDAY NIGHT.
&&
.NEAR TERM /REST OF TODAY/...
MAIN FORECAST CONCERN TODAY IS PRECIPITATION AND TEMPERATURE
TREND... MOREOVER WHAT PRECIP TYPES WILL IMPACT THE AREA WITH
APPROACHING SURFACE LOW TO THE SOUTHWEST. UPON A COMPARISON WITH
CURRENT OBSERVATIONS... THE NAM HAS A GOOD HANDLE ON SURFACE
FEATURES AND BOTH NAM AND RUC HAVE THE BEST HANDLE ON SURFACE TEMPS
SO FAR. SHORT RANGE ENSEMBLE GUIDANCE GOES A BIT WARM KEEPING NEARLY
ALL OF THE FORECAST AREA ABOVE FREEZING WHEN THE PRECIPITATION
OCCURS. CURRENT THINKING WEIGHS IN MORE ON THE NAM AND RUC WITH
KEEPING NEAR TO SLIGHTLY BELOW FREEZING TEMPS ACROSS THE NORTHERN
THIRD OF THE FORECAST AREA.
THE NORTHERN MAJORITY OF THE AREA HAS BEEN TRENDING A FEW DEGREES
ABOVE PREVIOUS FORECAST... HOWEVER CONSIDERING EVAPORATIONAL COOLING
WITH ONSET OF PRECIP... THE TEMPS WILL LIKELY STAY STEADY OR ONLY
INCREASE BY A FEW DEGREES. THIS WILL KEEP THE NORTHERN HALF OF THE
FORECAST AREA AT 31 TO 33 DEGREES THRU 00Z. MAX TEMPS IN THE SOUTH
WILL LIKELY GET TO THE MID 30S.
FOR PRECIP TIMING AND AMOUNT... SHORT RANGE GUIDANCE IS IN GOOD
AGREEMENT WITH ONSET OF PRECIP OCCURRING FROM THE SOUTHWEST STARTING
NEAR 18Z AND SPREADING NORTHEASTWARD ACROSS THE MAJORITY OF THE
FORECAST AREA BY 00Z. QPF LOOKS TO BE LIGHT WITH A FEW HUNDREDTHS IN
THE NORTH TO NEAR A TENTH OF AN INCH IN THE SOUTHWEST... WHERE MORE
RAIN SHOWERS WILL HAVE OCCURRED.
CONSIDERING THE ABOVE ALONG WITH FORECAST SOUNDING DATA AND THE
DEPTH OF THE WARM NOSE IN THE SATURATED COLUMN... PRECIP MAY START
OUT AS A BRIEF PERIOD OF LIGHT SLEET OR FREEZING DRIZZLE... BUT THEN
LIKELY TRANSITION TO LIGHT RAIN SHOWERS AND DRIZZLE AS WARM
ADVECTION AHEAD OF THE APPROACHING LOW BATTLES AGAINST THE LOW LEVEL
INVERSION.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
WARM FRONT WILL BE SET UP ALONG THE OHIO RIVER TONIGHT AS PREVIOUSLY
DISCUSSED ISENTROPIC LIFT AND MOISTURE CONTINUES. UPPER SUPPORT
REMAINS QUITE FAVORABLE TONIGHT AS A SHORT WAVE IS EXPECTED TOWARD
INDIANA FROM THE MAIN LOW. FURTHERMORE IN THE LOWER LEVELS MILD
AND MOIST GULF AIR CONTINUES TO STREAM INTO THE OHIO VALLEY. RAIN IS
EXPECTED TO REMAIN ACROSS THE AREA INTO THE EVENING HOURS. TIME
HEIGHTS AND FORECAST SOUNDINGS INDICATE SATURATION INTO THE
EVENINGS HOURS AS WELL. THUS WILL AGAIN USE WETTER POPS TONIGHT.
GIVEN THE EXPECTED CLOUDS AND RAIN WILL TREND TONIGHTS LOWS
WARMER THAN MAVMOS. SOME COOLER AIR AT THE SURFACE ACROSS THE
NORTHERN PARTS OF THE FORECAST AREA...LAFAYETTE...KOKOMO...MAY
RESULT IN SOME SNOW BEING MIXED IN AT THOSE LOCATIONS. ALTHOUGH
ACCUMULATIONS WOULD BE MINIMAL TO NONE.
MORE RAIN WILL BE EXPECTED ON THURSDAY AS THE UPPER LOW OVER THE
SOUTHERN PLAINS AND A TROUGH OF LOW PRESSURE ALOFT PUSH ACROSS THE
REGION PROVIDING AMPLE LIFT. FORECAST SOUNDINGS CONTINUE TO
INDICATE DEEP SATURATION AND KEEP THE LOWEST LEVELS OF THE
ATMOSPHERE ABOVE FREEZING. AGAIN WILL TREND HIGHER THAN MAVMOS
POPS ON THURSDAY AND COOLER ON HIGH TEMPERATURES GIVEN THE
EXPECTED RAIN.
UPPER SUPPORT FINALLY EXITS THE AREA TO THE EAST ON THURSDAY
NIGHT INTO FRIDAY MORNING AS A COOLER NORTHWEST FLOW BEGINS TO
TAKE SHAPE. FORECAST SOUNDINGS SHOW SIGNIFICANT DRYING AFTER 00Z
FRIDAY AS STRONG SUBSIDENCE TAKES SHAPE. 850MB SURFACE SHOWS
STRONG COLD AIR ADVECTION ACROSS THE AREA AS THEY FALL TO THE NEAR
-2C BY 12Z FRI. FORECAST SOUNDINGS ALSO DO NOT HINT AT LINGERING
STRATOCU AS STRONG SURFACE RIDGING BUILDS ACROSS THE AREA ON
THURSDAY NIGHT. THUS WILL TREND TOWARD BECOMING CLEAR ALONG WITH
LOWS ON THURSDAY NIGHT COOLER THAN MAVMOS.
DRY WEATHER IS EXPECTED ON FRIDAY AS THE SURFACE RIDGE MOVES
ACROSS THE AREA. THE QUICK NORTHWEST FLOW ALOFT MAY ALLOW FOR SOME
PASSING CLOUDS...BUT FOR NOW PTCLDY WILL WORK FIND ALONG WITH
TEMPS COOLER THAN MAVMOS GIVEN THE 850MB TEMPS.
A WEAK CLIPPER IS THEN EXPECTED TO PUSH THROUGH THE AREA ON FRIDAY
NIGHT. HOWEVER MOISTURE WILL REMAIN A PROBLEM WITH THIS WEAK SYSTEM
AS IT WILL ONLY HAVE PACIFIC MOISTURE TO WORK WITH AND ONLY
MARGINAL SUPPORT ALOFT. FOR NOW WILL TREND TOWARD JUST A MOSTLY
CLOUDY SKY...WITH LOWS COOLER THAN MEXMOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BY THE START OF THE EXTENDED PERIOD ENSEMBLES HAVE THE REGION
ESTABLISHED IN ZONAL FLOW WHICH LASTS THROUGH EARLY NEXT WEEK. A
WEAK UPPER TROUGH SHIFTS THROUGH THE GREAT LAKES REGION SUNDAY INTO
SUNDAY NIGHT BUT THIS FEATURE APPEARS TO STAY FAR NORTHWARD SO AS
NOT TO AFFECT CENTRAL INDIANA. THE FORECAST AREA WILL THEREFORE
REMAIN DRY FOR THE MAJORITY OF THE PERIOD...AND TEMPERATURES WILL
MODERATE BACK TO ABOVE NORMAL BY EARLY NEXT WEEK. ENSEMBLES SUGGEST
THE NEXT UPPER SYSTEM WILL NOT ARRIVE UNTIL TUESDAY INTO TUESDAY
NIGHT...WHICH THEY HAVE BEEN DEPICTING THESE PAST FEW MODEL RUNS.
BUMPED UP CHANCE POPS SLIGHTLY DURING THIS PERIOD TO ACCOUNT FOR
GOOD CONTINUITY AND CONSENSUS THUS FAR. PRECIPITATION TYPE AT THIS
TIME LOOKS TO BE ALL RAIN.
&&
.AVIATION /DISCUSSION FOR THE 251800Z TAFS/...
1945Z UPDATE...ADDED SLEET TO KIND TAF BASED ON REPORTS UPSTREAM.
THIS IS A VERY TRICKY FORECAST SO OPTED TO USE -RAPL FOR NOW UNTIL
03Z. THIS SHOULD NOT HAVE AN IMMEDIATE IMPACT UPON FLIGHT
CATEGORY...HOWEVER THAT SHOULD CHANGE IN A COUPLE OF HOURS.
PREVIOUS DISCUSSION FOLLOWS...
1900Z UPDATE...ADDED -RASN TO KHUF TAF BASED ON OBSERVATIONS
UPSTREAM. THIS SHOULD NOT HAVE AN IMPACT ON THE FLIGHT CATEGORY AT
THIS TIME BUT WILL CONTINUE TO MONITOR FOR FUTURE UPDATES.
PREVIOUS DISCUSSION FOLLOWS...
VERY TRICKY PUBLIC AND AVIATION FORECAST SHAPING UP FOR THE REST
OF TODAY AND TONIGHT. AS TEMPERATURES HOVER AROUND THE FREEZING
MARK THIS HOUR...RAIN IS TRYING TO SPREAD INTO CENTRAL INDIANA
FROM THE SW. AS EXPECTED...CEILINGS ARE GRADUALLY LOWERING AND
WILL CONTINUE THIS TREND UNTIL THEY ARE AT MFVR THIS EVENING WITH
THE CHANCE FOR -RA. WITH SURFACE TEMPS RIGHT AROUND THE FREEZING
MARK...FREEZING RAIN AND EVEN SLEET CANNOT BE RULED OUT AT TIMES
ACROSS THE AREA. BUT FOR NOW BASED ON WARMER TEMP TRENDS (AND
MODEL THICKNESSES) OPTED TO GO WITH JUST -RA THE ENTIRE PERIOD.
DEEPER MOISTURE MOVES INTO THE AREA TONIGHT INTO THURSDAY AND A
PROLONGED PERIOD OF IFR CAN BE EXPECTED AT ALL OF THE TERMINALS
BEGINNING BETWEEN 04-08Z AND LASTING THROUGH ALL OF THU MORNING.
FLIGHT CONDITIONS ARE NOT SET TO IMPROVE AT THE END OF THE TAF
PERIOD...AT BEST ONLY TO LOW END MFVR.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 AM EST THURSDAY FOR INZ021-
028>031-035>049-051-052.
&&
$$
SYNOPSIS...SMF
NEAR TERM...AB/JK
SHORT TERM...PUMA
LONG TERM....SMF
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
238 PM EST WED JAN 25 2012
.UPDATE...
THE SYNOPSIS SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHEAST ALONG A WARM FRONT INTO THE
OHIO VALLEY TONIGHT. A STRONGER UPPER LOW WILL THEN PASS THROUGH
THE TENNESSEE VALLEY ON THURSDAY ACCOMPANIED BY A TROUGH OF LOW
PRESSURE ALOFT. AS THIS UPPER SYSTEM DEPARTS ON THURSDAY
NIGHT...THE FRONTAL BOUNDARY TO THE SOUTH AND EAST OF INDIANA WILL
PUSH EAST AS A COLD FRONT. AFTERWARD DRY...NORTHWEST FLOW OF
CANADIAN AIR WILL BEGIN ACROSS CENTRAL INDIANA. HIGH PRESSURE WILL
RETURN TO THE STATE ON FRIDAY BRINGING DRY WEATHER BACK TO THE
STATE FOR THE WEEKEND AND INTO EARLY NEXT WEEK. THE NEXT SYSTEM TO
IMPACT THE REGION WILL ARRIVE NEXT TUESDAY INTO TUESDAY NIGHT.
&&
.NEAR TERM /REST OF TODAY/...
MAIN FORECAST CONCERN TODAY IS PRECIPITATION AND TEMPERATURE
TREND... MOREOVER WHAT PRECIP TYPES WILL IMPACT THE AREA WITH
APPROACHING SURFACE LOW TO THE SOUTHWEST. UPON A COMPARISON WITH
CURRENT OBSERVATIONS... THE NAM HAS A GOOD HANDLE ON SURFACE
FEATURES AND BOTH NAM AND RUC HAVE THE BEST HANDLE ON SURFACE TEMPS
SO FAR. SHORT RANGE ENSEMBLE GUIDANCE GOES A BIT WARM KEEPING NEARLY
ALL OF THE FORECAST AREA ABOVE FREEZING WHEN THE PRECIPITATION
OCCURS. CURRENT THINKING WEIGHS IN MORE ON THE NAM AND RUC WITH
KEEPING NEAR TO SLIGHTLY BELOW FREEZING TEMPS ACROSS THE NORTHERN
THIRD OF THE FORECAST AREA.
THE NORTHERN MAJORITY OF THE AREA HAS BEEN TRENDING A FEW DEGREES
ABOVE PREVIOUS FORECAST... HOWEVER CONSIDERING EVAPORATIONAL COOLING
WITH ONSET OF PRECIP... THE TEMPS WILL LIKELY STAY STEADY OR ONLY
INCREASE BY A FEW DEGREES. THIS WILL KEEP THE NORTHERN HALF OF THE
FORECAST AREA AT 31 TO 33 DEGREES THRU 00Z. MAX TEMPS IN THE SOUTH
WILL LIKELY GET TO THE MID 30S.
FOR PRECIP TIMING AND AMOUNT... SHORT RANGE GUIDANCE IS IN GOOD
AGREEMENT WITH ONSET OF PRECIP OCCURRING FROM THE SOUTHWEST STARTING
NEAR 18Z AND SPREADING NORTHEASTWARD ACROSS THE MAJORITY OF THE
FORECAST AREA BY 00Z. QPF LOOKS TO BE LIGHT WITH A FEW HUNDREDTHS IN
THE NORTH TO NEAR A TENTH OF AN INCH IN THE SOUTHWEST... WHERE MORE
RAIN SHOWERS WILL HAVE OCCURRED.
CONSIDERING THE ABOVE ALONG WITH FORECAST SOUNDING DATA AND THE
DEPTH OF THE WARM NOSE IN THE SATURATED COLUMN... PRECIP MAY START
OUT AS A BRIEF PERIOD OF LIGHT SLEET OR FREEZING DRIZZLE... BUT THEN
LIKELY TRANSITION TO LIGHT RAIN SHOWERS AND DRIZZLE AS WARM
ADVECTION AHEAD OF THE APPROACHING LOW BATTLES AGAINST THE LOW LEVEL
INVERSION.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
WARM FRONT WILL BE SET UP ALONG THE OHIO RIVER TONIGHT AS PREVIOUSLY
DISCUSSED ISENTROPIC LIFT AND MOISTURE CONTINUES. UPPER SUPPORT
REMAINS QUITE FAVORABLE TONIGHT AS A SHORT WAVE IS EXPECTED TOWARD
INDIANA FROM THE MAIN LOW. FURTHERMORE IN THE LOWER LEVELS MILD
AND MOIST GULF AIR CONTINUES TO STREAM INTO THE OHIO VALLEY. RAIN IS
EXPECTED TO REMAIN ACROSS THE AREA INTO THE EVENING HOURS. TIME
HEIGHTS AND FORECAST SOUNDINGS INDICATE SATURATION INTO THE
EVENINGS HOURS AS WELL. THUS WILL AGAIN USE WETTER POPS TONIGHT.
GIVEN THE EXPECTED CLOUDS AND RAIN WILL TREND TONIGHTS LOWS
WARMER THAN MAVMOS. SOME COOLER AIR AT THE SURFACE ACROSS THE
NORTHERN PARTS OF THE FORECAST AREA...LAFAYETTE...KOKOMO...MAY
RESULT IN SOME SNOW BEING MIXED IN AT THOSE LOCATIONS. ALTHOUGH
ACCUMULATIONS WOULD BE MINIMAL TO NONE.
MORE RAIN WILL BE EXPECTED ON THURSDAY AS THE UPPER LOW OVER THE
SOUTHERN PLAINS AND A TROUGH OF LOW PRESSURE ALOFT PUSH ACROSS THE
REGION PROVIDING AMPLE LIFT. FORECAST SOUNDINGS CONTINUE TO
INDICATE DEEP SATURATION AND KEEP THE LOWEST LEVELS OF THE
ATMOSPHERE ABOVE FREEZING. AGAIN WILL TREND HIGHER THAN MAVMOS
POPS ON THURSDAY AND COOLER ON HIGH TEMPERATURES GIVEN THE
EXPECTED RAIN.
UPPER SUPPORT FINALLY EXITS THE AREA TO THE EAST ON THURSDAY
NIGHT INTO FRIDAY MORNING AS A COOLER NORTHWEST FLOW BEGINS TO
TAKE SHAPE. FORECAST SOUNDINGS SHOW SIGNIFICANT DRYING AFTER 00Z
FRIDAY AS STRONG SUBSIDENCE TAKES SHAPE. 850MB SURFACE SHOWS
STRONG COLD AIR ADVECTION ACROSS THE AREA AS THEY FALL TO THE NEAR
-2C BY 12Z FRI. FORECAST SOUNDINGS ALSO DO NOT HINT AT LINGERING
STRATOCU AS STRONG SURFACE RIDGING BUILDS ACROSS THE AREA ON
THURSDAY NIGHT. THUS WILL TREND TOWARD BECOMING CLEAR ALONG WITH
LOWS ON THURSDAY NIGHT COOLER THAN MAVMOS.
DRY WEATHER IS EXPECTED ON FRIDAY AS THE SURFACE RIDGE MOVES
ACROSS THE AREA. THE QUICK NORTHWEST FLOW ALOFT MAY ALLOW FOR SOME
PASSING CLOUDS...BUT FOR NOW PTCLDY WILL WORK FIND ALONG WITH
TEMPS COOLER THAN MAVMOS GIVEN THE 850MB TEMPS.
A WEAK CLIPPER IS THEN EXPECTED TO PUSH THROUGH THE AREA ON FRIDAY
NIGHT. HOWEVER MOISTURE WILL REMAIN A PROBLEM WITH THIS WEAK SYSTEM
AS IT WILL ONLY HAVE PACIFIC MOISTURE TO WORK WITH AND ONLY
MARGINAL SUPPORT ALOFT. FOR NOW WILL TREND TOWARD JUST A MOSTLY
CLOUDY SKY...WITH LOWS COOLER THAN MEXMOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BY THE START OF THE EXTENDED PERIOD ENSEMBLES HAVE THE REGION
ESTABLISHED IN ZONAL FLOW WHICH LASTS THROUGH EARLY NEXT WEEK. A
WEAK UPPER TROUGH SHIFTS THROUGH THE GREAT LAKES REGION SUNDAY INTO
SUNDAY NIGHT BUT THIS FEATURE APPEARS TO STAY FAR NORTHWARD SO AS
NOT TO AFFECT CENTRAL INDIANA. THE FORECAST AREA WILL THEREFORE
REMAIN DRY FOR THE MAJORITY OF THE PERIOD...AND TEMPERATURES WILL
MODERATE BACK TO ABOVE NORMAL BY EARLY NEXT WEEK. ENSEMBLES SUGGEST
THE NEXT UPPER SYSTEM WILL NOT ARRIVE UNTIL TUESDAY INTO TUESDAY
NIGHT...WHICH THEY HAVE BEEN DEPICTING THESE PAST FEW MODEL RUNS.
BUMPED UP CHANCE POPS SLIGHTLY DURING THIS PERIOD TO ACCOUNT FOR
GOOD CONTINUITY AND CONSENSUS THUS FAR. PRECIPITATION TYPE AT THIS
TIME LOOKS TO BE ALL RAIN.
&&
.AVIATION /DISCUSSION FOR THE 251800Z TAFS/...
19Z UPDATE...ADDED -RASN TO KHUF TAF BASED ON OBSERVATIONS
UPSTREAM. THIS SHOULD NOT HAVE AN IMPACT ON THE FLIGHT CATEGORY AT
THIS TIME BUT WILL CONTINUE TO MONITOR FOR FUTURE UPDATES.
PREVIOUS DISCUSSION FOLLOWS...
VERY TRICKY PUBLIC AND AVIATION FORECAST SHAPING UP FOR THE REST
OF TODAY AND TONIGHT. AS TEMPERATURES HOVER AROUND THE FREEZING
MARK THIS HOUR...RAIN IS TRYING TO SPREAD INTO CENTRAL INDIANA
FROM THE SW. AS EXPECTED...CEILINGS ARE GRADUALLY LOWERING AND
WILL CONTINUE THIS TREND UNTIL THEY ARE AT MFVR THIS EVENING WITH
THE CHANCE FOR -RA. WITH SURFACE TEMPS RIGHT AROUND THE FREEZING
MARK...FREEZING RAIN AND EVEN SLEET CANNOT BE RULED OUT AT TIMES
ACROSS THE AREA. BUT FOR NOW BASED ON WARMER TEMP TRENDS (AND
MODEL THICKNESSES) OPTED TO GO WITH JUST -RA THE ENTIRE PERIOD.
DEEPER MOISTURE MOVES INTO THE AREA TONIGHT INTO THURSDAY AND A
PROLONGED PERIOD OF IFR CAN BE EXPECTED AT ALL OF THE TERMINALS
BEGINNING BETWEEN 04-08Z AND LASTING THROUGH ALL OF THU MORNING.
FLIGHT CONDITIONS ARE NOT SET TO IMPROVE AT THE END OF THE TAF
PERIOD...AT BEST ONLY TO LOW END MFVR.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 AM EST THURSDAY FOR INZ021-
028>031-035>049-051-052.
&&
$$
SYNOPSIS...SMF
NEAR TERM...AB/JK
SHORT TERM...PUMA
LONG TERM....SMF
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
214 PM EST WED JAN 25 2012
.UPDATE...
THE LONG TERM AND AVIATION SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
HIGH PRESSURE WAS FOUND ACROSS CENTRAL INDIANA EARLY
THIS MORNING. THE HIGH WILL DRIFT EAST OF INDIANA TODAY AS LOW
PRESSURE DEVELOPS IN THE SOUTHERN PLAINS. THE LOW WILL TRACK
NORTHEAST ALONG A WARM FRONT INTO THE OHIO VALLEY
TONIGHT...SPREADING RAIN SHOWERS.
A STRONGER UPPER LOW WILL THEN PASS THROUGH THE TENNESSEE VALLEY
ON THURSDAY ACCOMPANIED BY A TROUGH OF LOW PRESSURE ALOFT. THIS
WILL RESULT IN A WET THURSDAY. AS THIS UPPER SYSTEM DEPARTS ON
THURSDAY NIGHT...THE FRONTAL BOUNDARY TO THE SOUTH AND EAST OF
INDIANA WILL PUSH EAST AS WELL AS A COLD FRONT AND A
DRY...NORTHWEST FLOW OF CANADIAN AIR WILL BEGIN ACROSS CENTRAL
INDIANA.
HIGH PRESSURE WILL THEN RETURN TO THE STATE ON FRIDAY BRINGING DRY
WEATHER BACK TO THE STATE FOR THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
MAIN FORECAST CONCERN TODAY IS PRECIPITATION AND TEMPERATURE
TREND... MOREOVER WHAT PRECIP TYPES WILL IMPACT THE AREA WITH
APPROACHING SURFACE LOW TO THE SOUTHWEST. UPON A COMPARISON WITH
CURRENT OBSERVATIONS... THE NAM HAS A GOOD HANDLE ON SURFACE
FEATURES AND BOTH NAM AND RUC HAVE THE BEST HANDLE ON SURFACE TEMPS
SO FAR. SHORT RANGE ENSEMBLE GUIDANCE GOES A BIT WARM KEEPING NEARLY
ALL OF THE FORECAST AREA ABOVE FREEZING WHEN THE PRECIPITATION
OCCURS. CURRENT THINKING WEIGHS IN MORE ON THE NAM AND RUC WITH
KEEPING NEAR TO SLIGHTLY BELOW FREEZING TEMPS ACROSS THE NORTHERN
THIRD OF THE FORECAST AREA.
THE NORTHERN MAJORITY OF THE AREA HAS BEEN TRENDING A FEW DEGREES
ABOVE PREVIOUS FORECAST... HOWEVER CONSIDERING EVAPORATIONAL COOLING
WITH ONSET OF PRECIP... THE TEMPS WILL LIKELY STAY STEADY OR ONLY
INCREASE BY A FEW DEGREES. THIS WILL KEEP THE NORTHERN HALF OF THE
FORECAST AREA AT 31 TO 33 DEGREES THRU 00Z. MAX TEMPS IN THE SOUTH
WILL LIKELY GET TO THE MID 30S.
FOR PRECIP TIMING AND AMOUNT... SHORT RANGE GUIDANCE IS IN GOOD
AGREEMENT WITH ONSET OF PRECIP OCCURRING FROM THE SOUTHWEST STARTING
NEAR 18Z AND SPREADING NORTHEASTWARD ACROSS THE MAJORITY OF THE
FORECAST AREA BY 00Z. QPF LOOKS TO BE LIGHT WITH A FEW HUNDREDTHS IN
THE NORTH TO NEAR A TENTH OF AN INCH IN THE SOUTHWEST... WHERE MORE
RAIN SHOWERS WILL HAVE OCCURRED.
CONSIDERING THE ABOVE ALONG WITH FORECAST SOUNDING DATA AND THE
DEPTH OF THE WARM NOSE IN THE SATURATED COLUMN... PRECIP MAY START
OUT AS A BRIEF PERIOD OF LIGHT SLEET OR FREEZING DRIZZLE... BUT THEN
LIKELY TRANSITION TO LIGHT RAIN SHOWERS AND DRIZZLE AS WARM
ADVECTION AHEAD OF THE APPROACHING LOW BATTLES AGAINST THE LOW LEVEL
INVERSION.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
WARM FRONT WILL BE SET UP ALONG THE OHIO RIVER TONIGHT AS PREVIOUSLY
DISCUSSED ISENTROPIC LIFT AND MOISTURE CONTINUES. UPPER SUPPORT
REMAINS QUITE FAVORABLE TONIGHT AS A SHORT WAVE IS EXPECTED TOWARD
INDIANA FROM THE MAIN LOW. FURTHERMORE IN THE LOWER LEVELS MILD
AND MOIST GULF AIR CONTINUES TO STREAM INTO THE OHIO VALLEY. RAIN IS
EXPECTED TO REMAIN ACROSS THE AREA INTO THE EVENING HOURS. TIME
HEIGHTS AND FORECAST SOUNDINGS INDICATE SATURATION INTO THE
EVENINGS HOURS AS WELL. THUS WILL AGAIN USE WETTER POPS TONIGHT.
GIVEN THE EXPECTED CLOUDS AND RAIN WILL TREND TONIGHTS LOWS
WARMER THAN MAVMOS. SOME COOLER AIR AT THE SUFACE ACROSS THE
NORTHERN PARTS OF THE FORECAST AREA...LAFAYETTE...KOKOMO...MAY
RESULT IN SOME SNOW BEING MIXED IN AT THOSE LOCATIONS. ALTHOUGH
ACCUMULATIONS WOULD BE MINIMAL TO NONE.
MORE RAIN WILL BE EXPECTED ON THURSDAY AS THE UPPER LOW OVER THE
SOUTHERN PLAINS AND A TROUGH OF LOW PRESSURE ALOFT PUSH ACROSS THE
REGION PROVIDING AMPLE LIFT. FORECAST SOUNDINGS CONTINUE TO
INDICATE DEEP SATURATION AND KEEP THE LOWEST LEVELS OF THE
ATMOSPHERE ABOVE FREEZING. AGAIN WILL TREND HIGHER THAN MAVMOS
POPS ON THURSDAY AND COOLER ON HIGH TEMPERATURES GIVEN THE
EXPECTED RAIN.
UPPER SUPPORT FINALLY EXITS THE AREA TO THE EAST ON THURSDAY
NIGHT INTO FRIDAY MORNING AS A COOLER NORTHWEST FLOW BEGINS TO
TAKE SHAPE. FORECAST SOUNDINGS SHOW SIGNIFICANT DRYING AFTER 00Z
FRIDAY AS STRONG SUBSIDENCE TAKES SHAPE. 850MB SURFACE SHOWS
STRONG COLD AIR ADVECTION ACROSS THE AREA AS THEY FALL TO THE NEAR
-2C BY 12Z FRI. FORECAST SOUNDINGS ALSO DO NOT HINT AT LINGERING
STRATOCU AS STRONG SURFACE RIDGING BUILDS ACROSS THE AREA ON
THURSDAY NIGHT. THUS WILL TREND TOWARD BECOMING CLEAR ALONG WITH
LOWS ON THURSDAY NIGHT COOLER THAN MAVMOS.
DRY WEATHER IS EXPECTED ON FRIDAY AS THE SURFACE RIDGE MOVES
ACROSS THE AREA. THE QUICK NORTHWEST FLOW ALOFT MAY ALLOW FOR SOME
PASSING CLOUDS...BUT FOR NOW PTCLDY WILL WORK FIND ALONG WITH
TEMPS COOLER THAN MAVMOS GIVEN THE 850MB TEMPS.
A WEAK CLIPPER IS THEN EXPECTED TO PUSH THROUGH THE AREA ON FRIDAY
NIGHT. HOWEVER MOISTURE WILL REMAIN A PROBLEM WITH THIS WEAK SYSTEM
AS IT WILL ONLY HAVE PACIFIC MOISTURE TO WORK WITH AND ONLY
MARGINAL SUPPORT ALOFT. FOR NOW WILL TREND TOWARD JUST A MOSTLY
CLOUDY SKY...WITH LOWS COOLER THAN MEXMOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
BY THE START OF THE EXTENDED PERIOD ENSEMBLES HAVE THE REGION
ESTABLISHED IN ZONAL FLOW WHICH LASTS THROUGH EARLY NEXT WEEK. A
WEAK UPPER TROUGH SHIFTS THROUGH THE GREAT LAKES REGION SUNDAY INTO
SUNDAY NIGHT BUT THIS FEATURE APPEARS TO STAY FAR NORTHWARD SO AS
NOT TO AFFECT CENTRAL INDIANA. THE FORECAST AREA WILL THEREFORE
REMAIN DRY FOR THE MAJORITY OF THE PERIOD...AND TEMPERATURES WILL
MODERATE BACK TO ABOVE NORMAL BY EARLY NEXT WEEK. ENSEMBLES SUGGEST
THE NEXT UPPER SYSTEM WILL NOT ARRIVE UNTIL TUESDAY INTO TUESDAY
NIGHT...WHICH THEY HAVE BEEN DEPICTING THESE PAST FEW MODEL RUNS.
BUMPED UP CHANCE POPS SLIGHTLY DURING THIS PERIOD TO ACCOUNT FOR
GOOD CONTINUITY AND CONSENSUS THUS FAR. PRECIPITATION TYPE AT THIS
TIME LOOKS TO BE ALL RAIN.
&&
.AVIATION /DISCUSSION FOR THE 251800Z TAFS/...
19Z UPDATE...ADDED -RASN TO KHUF TAF BASED ON OBSERVATIONS
UPSTREAM. THIS SHOULD NOT HAVE AN IMPACT ON THE FLIGHT CATEGORY AT
THIS TIME BUT WILL CONTINUE TO MONITOR FOR FUTURE UPDATES.
PREVIOUS DISCUSSION FOLLOWS...
VERY TRICKY PUBLIC AND AVIATION FORECAST SHAPING UP FOR THE REST
OF TODAY AND TONIGHT. AS TEMPERATURES HOVER AROUND THE FREEZING
MARK THIS HOUR...RAIN IS TRYING TO SPREAD INTO CENTRAL INDIANA
FROM THE SW. AS EXPECTED...CEILINGS ARE GRADUALLY LOWERING AND
WILL CONTINUE THIS TREND UNTIL THEY ARE AT MFVR THIS EVENING WITH
THE CHANCE FOR -RA. WITH SURFACE TEMPS RIGHT AROUND THE FREEZING
MARK...FREEZING RAIN AND EVEN SLEET CANNOT BE RULED OUT AT TIMES
ACROSS THE AREA. BUT FOR NOW BASED ON WARMER TEMP TRENDS (AND
MODEL THICKNESSES) OPTED TO GO WITH JUST -RA THE ENTIRE PERIOD.
DEEPER MOISTURE MOVES INTO THE AREA TONIGHT INTO THURSDAY AND A
PROLONGED PERIOD OF IFR CAN BE EXPECTED AT ALL OF THE TERMINALS
BEGINNING BETWEEN 04-08Z AND LASTING THROUGH ALL OF THU MORNING.
FLIGHT CONDITIONS ARE NOT SET TO IMPROVE AT THE END OF THE TAF
PERIOD...AT BEST ONLY TO LOW END MFVR.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...AB/JK
SHORT TERM...PUMA
LONG TERM....SMF
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1233 PM EST WED JAN 25 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
HIGH PRESSURE WAS FOUND ACROSS CENTRAL INDIANA EARLY
THIS MORNING. THE HIGH WILL DRIFT EAST OF INDIANA TODAY AS LOW
PRESSURE DEVELOPS IN THE SOUTHERN PLAINS. THE LOW WILL TRACK
NORTHEAST ALONG A WARM FRONT INTO THE OHIO VALLEY
TONIGHT...SPREADING RAIN SHOWERS.
A STRONGER UPPER LOW WILL THEN PASS THROUGH THE TENNESSEE VALLEY
ON THURSDAY ACCOMPANIED BY A TROUGH OF LOW PRESSURE ALOFT. THIS
WILL RESULT IN A WET THURSDAY. AS THIS UPPER SYSTEM DEPARTS ON
THURSDAY NIGHT...THE FRONTAL BOUNDARY TO THE SOUTH AND EAST OF
INDIANA WILL PUSH EAST AS WELL AS A COLD FRONT AND A
DRY...NORTHWEST FLOW OF CANADIAN AIR WILL BEGIN ACROSS CENTRAL
INDIANA.
HIGH PRESSURE WILL THEN RETURN TO THE STATE ON FRIDAY BRINGING DRY
WEATHER BACK TO THE STATE FOR THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
MAIN FORECAST CONCERN TODAY IS PRECIPITATION AND TEMPERATURE
TREND... MOREOVER WHAT PRECIP TYPES WILL IMPACT THE AREA WITH
APPROACHING SURFACE LOW TO THE SOUTHWEST. UPON A COMPARISON WITH
CURRENT OBSERVATIONS... THE NAM HAS A GOOD HANDLE ON SURFACE
FEATURES AND BOTH NAM AND RUC HAVE THE BEST HANDLE ON SURFACE TEMPS
SO FAR. SHORT RANGE ENSEMBLE GUIDANCE GOES A BIT WARM KEEPING NEARLY
ALL OF THE FORECAST AREA ABOVE FREEZING WHEN THE PRECIPITATION
OCCURS. CURRENT THINKING WEIGHS IN MORE ON THE NAM AND RUC WITH
KEEPING NEAR TO SLIGHTLY BELOW FREEZING TEMPS ACROSS THE NORTHERN
THIRD OF THE FORECAST AREA.
THE NORTHERN MAJORITY OF THE AREA HAS BEEN TRENDING A FEW DEGREES
ABOVE PREVIOUS FORECAST... HOWEVER CONSIDERING EVAPORATIONAL COOLING
WITH ONSET OF PRECIP... THE TEMPS WILL LIKELY STAY STEADY OR ONLY
INCREASE BY A FEW DEGREES. THIS WILL KEEP THE NORTHERN HALF OF THE
FORECAST AREA AT 31 TO 33 DEGREES THRU 00Z. MAX TEMPS IN THE SOUTH
WILL LIKELY GET TO THE MID 30S.
FOR PRECIP TIMING AND AMOUNT... SHORT RANGE GUIDANCE IS IN GOOD
AGREEMENT WITH ONSET OF PRECIP OCCURRING FROM THE SOUTHWEST STARTING
NEAR 18Z AND SPREADING NORTHEASTWARD ACROSS THE MAJORITY OF THE
FORECAST AREA BY 00Z. QPF LOOKS TO BE LIGHT WITH A FEW HUNDREDTHS IN
THE NORTH TO NEAR A TENTH OF AN INCH IN THE SOUTHWEST... WHERE MORE
RAIN SHOWERS WILL HAVE OCCURRED.
CONSIDERING THE ABOVE ALONG WITH FORECAST SOUNDING DATA AND THE
DEPTH OF THE WARM NOSE IN THE SATURATED COLUMN... PRECIP MAY START
OUT AS A BRIEF PERIOD OF LIGHT SLEET OR FREEZING DRIZZLE... BUT THEN
LIKELY TRANSITION TO LIGHT RAIN SHOWERS AND DRIZZLE AS WARM
ADVECTION AHEAD OF THE APPROACHING LOW BATTLES AGAINST THE LOW LEVEL
INVERSION.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
WARM FRONT WILL BE SET UP ALONG THE OHIO RIVER TONIGHT AS PREVIOUSLY
DISCUSSED ISENTROPIC LIFT AND MOISTURE CONTINUES. UPPER SUPPORT
REMAINS QUITE FAVORABLE TONIGHT AS A SHORT WAVE IS EXPECTED TOWARD
INDIANA FROM THE MAIN LOW. FURTHERMORE IN THE LOWER LEVELS MILD
AND MOIST GULF AIR CONTINUES TO STREAM INTO THE OHIO VALLEY. RAIN IS
EXPECTED TO REMAIN ACROSS THE AREA INTO THE EVENING HOURS. TIME
HEIGHTS AND FORECAST SOUNDINGS INDICATE SATURATION INTO THE
EVENINGS HOURS AS WELL. THUS WILL AGAIN USE WETTER POPS TONIGHT.
GIVEN THE EXPECTED CLOUDS AND RAIN WILL TREND TONIGHTS LOWS
WARMER THAN MAVMOS. SOME COOLER AIR AT THE SUFACE ACROSS THE
NORTHERN PARTS OF THE FORECAST AREA...LAFAYETTE...KOKOMO...MAY
RESULT IN SOME SNOW BEING MIXED IN AT THOSE LOCATIONS. ALTHOUGH
ACCUMULATIONS WOULD BE MINIMAL TO NONE.
MORE RAIN WILL BE EXPECTED ON THURSDAY AS THE UPPER LOW OVER THE
SOUTHERN PLAINS AND A TROUGH OF LOW PRESSURE ALOFT PUSH ACROSS THE
REGION PROVIDING AMPLE LIFT. FORECAST SOUNDINGS CONTINUE TO
INDICATE DEEP SATURATION AND KEEP THE LOWEST LEVELS OF THE
ATMOSPHERE ABOVE FREEZING. AGAIN WILL TREND HIGHER THAN MAVMOS
POPS ON THURSDAY AND COOLER ON HIGH TEMPERATURES GIVEN THE
EXPECTED RAIN.
UPPER SUPPORT FINALLY EXITS THE AREA TO THE EAST ON THURSDAY
NIGHT INTO FRIDAY MORNING AS A COOLER NORTHWEST FLOW BEGINS TO
TAKE SHAPE. FORECAST SOUNDINGS SHOW SIGNIFICANT DRYING AFTER 00Z
FRIDAY AS STRONG SUBSIDENCE TAKES SHAPE. 850MB SURFACE SHOWS
STRONG COLD AIR ADVECTION ACROSS THE AREA AS THEY FALL TO THE NEAR
-2C BY 12Z FRI. FORECAST SOUNDINGS ALSO DO NOT HINT AT LINGERING
STRATOCU AS STRONG SURFACE RIDGING BUILDS ACROSS THE AREA ON
THURSDAY NIGHT. THUS WILL TREND TOWARD BECOMING CLEAR ALONG WITH
LOWS ON THURSDAY NIGHT COOLER THAN MAVMOS.
DRY WEATHER IS EXPECTED ON FRIDAY AS THE SURFACE RIDGE MOVES
ACROSS THE AREA. THE QUICK NORTHWEST FLOW ALOFT MAY ALLOW FOR SOME
PASSING CLOUDS...BUT FOR NOW PTCLDY WILL WORK FIND ALONG WITH
TEMPS COOLER THAN MAVMOS GIVEN THE 850MB TEMPS.
A WEAK CLIPPER IS THEN EXPECTED TO PUSH THROUGH THE AREA ON FRIDAY
NIGHT. HOWEVER MOISTURE WILL REMAIN A PROBLEM WITH THIS WEAK SYSTEM
AS IT WILL ONLY HAVE PACIFIC MOISTURE TO WORK WITH AND ONLY
MARGINAL SUPPORT ALOFT. FOR NOW WILL TREND TOWARD JUST A MOSTLY
CLOUDY SKY...WITH LOWS COOLER THAN MEXMOS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ENSEMBLE DATA ARE SUGGESTING BROAD UPPER LEVEL TROUGHING OVER THE
EASTERN PARTS OF THE COUNTRY...WHICH BECOMES MORE ZONAL BY EARLY
NEXT WEEK. LOOKS LIKE A PRETTY QUIET PERIOD...WITH THE ENSEMBLES
SUGGESTING THE NEXT UPPER SYSTEM NOT ARRIVING UNTIL NEXT TUESDAY.
WILL INTRODUCE CHANCE POPS AT THAT TIME. SYSTEM LOOKS TO BE A RAIN
PRODUCER AT THIS TIME WITH ONLY A COUPLE OF MEMBERS INDICATING
SNOW POTENTIAL WITH THIS SYSTEM.
A FEW ENSEMBLES ARE BEGINNING TO INDICATE THE POTENTIAL FOR A
CLIPPER TYPE SYSTEM MOVING THROUGH THE GENERAL AREA OVER THIS
WEEKEND...WITH THE POTENTIAL FOR SOME LIGHT SNOWS. AT THIS
TIME...WILL KEEP THE WEEKEND DRY...BUT MAY NEED TO ADD POPS FOR
LIGHT SNOW AT A LATER TIME.
&&
.AVIATION /DISCUSSION FOR THE 251800Z TAFS/...
VERY TRICKY PUBLIC AND AVIATION FORECAST SHAPING UP FOR THE REST
OF TODAY AND TONIGHT. AS TEMPERATURES HOVER AROUND THE FREEZING
MARK THIS HOUR...RAIN IS TRYING TO SPREAD INTO CENTRAL INDIANA
FROM THE SW. AS EXPECTED...CEILINGS ARE GRADUALLY LOWERING AND
WILL CONTINUE THIS TREND UNTIL THEY ARE AT MFVR THIS EVENING WITH
THE CHANCE FOR -RA. WITH SURFACE TEMPS RIGHT AROUND THE FREEZING
MARK...FREEZING RAIN AND EVEN SLEET CANNOT BE RULED OUT AT TIMES
ACROSS THE AREA. BUT FOR NOW BASED ON WARMER TEMP TRENDS (AND
MODEL THICKNESSES) OPTED TO GO WITH JUST -RA THE ENTIRE PERIOD.
DEEPER MOISTURE MOVES INTO THE AREA TONIGHT INTO THURSDAY AND A
PROLONGED PERIOD OF IFR CAN BE EXPECTED AT ALL OF THE TERMINALS
BEGINNING BETWEEN 04-08Z AND LASTING THROUGH ALL OF THU MORNING.
FLIGHT CONDITIONS ARE NOT SET TO IMPROVE AT THE END OF THE TAF
PERIOD...AT BEST ONLY TO LOW END MFVR.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...AB/JK
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...SMF
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1131 AM EST WED JAN 25 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
HIGH PRESSURE WAS FOUND ACROSS CENTRAL INDIANA EARLY
THIS MORNING. THE HIGH WILL DRIFT EAST OF INDIANA TODAY AS LOW
PRESSURE DEVELOPS IN THE SOUTHERN PLAINS. THE LOW WILL TRACK
NORTHEAST ALONG A WARM FRONT INTO THE OHIO VALLEY
TONIGHT...SPREADING RAIN SHOWERS.
A STRONGER UPPER LOW WILL THEN PASS THROUGH THE TENNESSEE VALLEY
ON THURSDAY ACCOMPANIED BY A TROUGH OF LOW PRESSURE ALOFT. THIS
WILL RESULT IN A WET THURSDAY. AS THIS UPPER SYSTEM DEPARTS ON
THURSDAY NIGHT...THE FRONTAL BOUNDARY TO THE SOUTH AND EAST OF
INDIANA WILL PUSH EAST AS WELL AS A COLD FRONT AND A
DRY...NORTHWEST FLOW OF CANADIAN AIR WILL BEGIN ACROSS CENTRAL
INDIANA.
HIGH PRESSURE WILL THEN RETURN TO THE STATE ON FRIDAY BRINGING DRY
WEATHER BACK TO THE STATE FOR THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
MAIN FORECAST CONCERN TODAY IS PRECIPITATION AND TEMPERATURE
TREND... MOREOVER WHAT PRECIP TYPES WILL IMPACT THE AREA WITH
APPROACHING SURFACE LOW TO THE SOUTHWEST. UPON A COMPARISON WITH
CURRENT OBSERVATIONS... THE NAM HAS A GOOD HANDLE ON SURFACE
FEATURES AND BOTH NAM AND RUC HAVE THE BEST HANDLE ON SURFACE TEMPS
SO FAR. SHORT RANGE ENSEMBLE GUIDANCE GOES A BIT WARM KEEPING NEARLY
ALL OF THE FORECAST AREA ABOVE FREEZING WHEN THE PRECIPITATION
OCCURS. CURRENT THINKING WEIGHS IN MORE ON THE NAM AND RUC WITH
KEEPING NEAR TO SLIGHTLY BELOW FREEZING TEMPS ACROSS THE NORTHERN
THIRD OF THE FORECAST AREA.
THE NORTHERN MAJORITY OF THE AREA HAS BEEN TRENDING A FEW DEGREES
ABOVE PREVIOUS FORECAST... HOWEVER CONSIDERING EVAPORATIONAL COOLING
WITH ONSET OF PRECIP... THE TEMPS WILL LIKELY STAY STEADY OR ONLY
INCREASE BY A FEW DEGREES. THIS WILL KEEP THE NORTHERN HALF OF THE
FORECAST AREA AT 31 TO 33 DEGREES THRU 00Z. MAX TEMPS IN THE SOUTH
WILL LIKELY GET TO THE MID 30S.
FOR PRECIP TIMING AND AMOUNT... SHORT RANGE GUIDANCE IS IN GOOD
AGREEMENT WITH ONSET OF PRECIP OCCURRING FROM THE SOUTHWEST STARTING
NEAR 18Z AND SPREADING NORTHEASTWARD ACROSS THE MAJORITY OF THE
FORECAST AREA BY 00Z. QPF LOOKS TO BE LIGHT WITH A FEW HUNDREDTHS IN
THE NORTH TO NEAR A TENTH OF AN INCH IN THE SOUTHWEST... WHERE MORE
RAIN SHOWERS WILL HAVE OCCURRED.
CONSIDERING THE ABOVE ALONG WITH FORECAST SOUNDING DATA AND THE
DEPTH OF THE WARM NOSE IN THE SATURATED COLUMN... PRECIP MAY START
OUT AS A BRIEF PERIOD OF LIGHT SLEET OR FREEZING DRIZZLE... BUT THEN
LIKELY TRANSITION TO LIGHT RAIN SHOWERS AND DRIZZLE AS WARM
ADVECTION AHEAD OF THE APPROACHING LOW BATTLES AGAINST THE LOW LEVEL
INVERSION.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
WARM FRONT WILL BE SET UP ALONG THE OHIO RIVER TONIGHT AS PREVIOUSLY
DISCUSSED ISENTROPIC LIFT AND MOISTURE CONTINUES. UPPER SUPPORT
REMAINS QUITE FAVORABLE TONIGHT AS A SHORT WAVE IS EXPECTED TOWARD
INDIANA FROM THE MAIN LOW. FURTHERMORE IN THE LOWER LEVELS MILD
AND MOIST GULF AIR CONTINUES TO STREAM INTO THE OHIO VALLEY. RAIN IS
EXPECTED TO REMAIN ACROSS THE AREA INTO THE EVENING HOURS. TIME
HEIGHTS AND FORECAST SOUNDINGS INDICATE SATURATION INTO THE
EVENINGS HOURS AS WELL. THUS WILL AGAIN USE WETTER POPS TONIGHT.
GIVEN THE EXPECTED CLOUDS AND RAIN WILL TREND TONIGHTS LOWS
WARMER THAN MAVMOS. SOME COOLER AIR AT THE SUFACE ACROSS THE
NORTHERN PARTS OF THE FORECAST AREA...LAFAYETTE...KOKOMO...MAY
RESULT IN SOME SNOW BEING MIXED IN AT THOSE LOCATIONS. ALTHOUGH
ACCUMULATIONS WOULD BE MINIMAL TO NONE.
MORE RAIN WILL BE EXPECTED ON THURSDAY AS THE UPPER LOW OVER THE
SOUTHERN PLAINS AND A TROUGH OF LOW PRESSURE ALOFT PUSH ACROSS THE
REGION PROVIDING AMPLE LIFT. FORECAST SOUNDINGS CONTINUE TO
INDICATE DEEP SATURATION AND KEEP THE LOWEST LEVELS OF THE
ATMOSPHERE ABOVE FREEZING. AGAIN WILL TREND HIGHER THAN MAVMOS
POPS ON THURSDAY AND COOLER ON HIGH TEMPERATURES GIVEN THE
EXPECTED RAIN.
UPPER SUPPORT FINALLY EXITS THE AREA TO THE EAST ON THURSDAY
NIGHT INTO FRIDAY MORNING AS A COOLER NORTHWEST FLOW BEGINS TO
TAKE SHAPE. FORECAST SOUNDINGS SHOW SIGNIFICANT DRYING AFTER 00Z
FRIDAY AS STRONG SUBSIDENCE TAKES SHAPE. 850MB SURFACE SHOWS
STRONG COLD AIR ADVECTION ACROSS THE AREA AS THEY FALL TO THE NEAR
-2C BY 12Z FRI. FORECAST SOUNDINGS ALSO DO NOT HINT AT LINGERING
STRATOCU AS STRONG SURFACE RIDGING BUILDS ACROSS THE AREA ON
THURSDAY NIGHT. THUS WILL TREND TOWARD BECOMING CLEAR ALONG WITH
LOWS ON THURSDAY NIGHT COOLER THAN MAVMOS.
DRY WEATHER IS EXPECTED ON FRIDAY AS THE SURFACE RIDGE MOVES
ACROSS THE AREA. THE QUICK NORTHWEST FLOW ALOFT MAY ALLOW FOR SOME
PASSING CLOUDS...BUT FOR NOW PTCLDY WILL WORK FIND ALONG WITH
TEMPS COOLER THAN MAVMOS GIVEN THE 850MB TEMPS.
A WEAK CLIPPER IS THEN EXPECTED TO PUSH THROUGH THE AREA ON FRIDAY
NIGHT. HOWEVER MOISTURE WILL REMAIN A PROBLEM WITH THIS WEAK SYSTEM
AS IT WILL ONLY HAVE PACIFIC MOISTURE TO WORK WITH AND ONLY
MARGINAL SUPPORT ALOFT. FOR NOW WILL TREND TOWARD JUST A MOSTLY
CLOUDY SKY...WITH LOWS COOLER THAN MEXMOS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ENSEMBLE DATA ARE SUGGESTING BROAD UPPER LEVEL TROUGHING OVER THE
EASTERN PARTS OF THE COUNTRY...WHICH BECOMES MORE ZONAL BY EARLY
NEXT WEEK. LOOKS LIKE A PRETTY QUIET PERIOD...WITH THE ENSEMBLES
SUGGESTING THE NEXT UPPER SYSTEM NOT ARRIVING UNTIL NEXT TUESDAY.
WILL INTRODUCE CHANCE POPS AT THAT TIME. SYSTEM LOOKS TO BE A RAIN
PRODUCER AT THIS TIME WITH ONLY A COUPLE OF MEMBERS INDICATING
SNOW POTENTIAL WITH THIS SYSTEM.
A FEW ENSEMBLES ARE BEGINNING TO INDICATE THE POTENTIAL FOR A
CLIPPER TYPE SYSTEM MOVING THROUGH THE GENERAL AREA OVER THIS
WEEKEND...WITH THE POTENTIAL FOR SOME LIGHT SNOWS. AT THIS
TIME...WILL KEEP THE WEEKEND DRY...BUT MAY NEED TO ADD POPS FOR
LIGHT SNOW AT A LATER TIME.
&&
.AVIATION /DISCUSSION FOR THE 251200Z TAFS/...
1430Z UPDATE...MOISTURE IS MAKING IT/S WAY MUCH FASTER INTO
CENTRAL INDIANA ATTM. HAVE UPDATED MOST OF THE TERMINALS TO DEPICT
A QUICKER TIMING OF LOWERING OF CLOUD BASES AND INTRODUCE RAIN.
ATTM...FREEZING RAIN CANNOT BE RULED OUT AS TEMP HOVER AOB THE
FREEZING MARK AT THE SURFACE...BUT THESE SHOULD WARM A FEW DEGREES
IN THE NEXT FEW HOURS BEFORE THE BULK OF THE PRECIP ARRIVES SO
HAVE THEREFORE OMITTED ANY MENTION OF FZRA FOR NOW. PREVIOUS
DISCUSSION FOLLOWS.
EXPECTING CEILINGS GENERALLY ABOVE 050 FOR THE MOST PART
TODAY...UNTIL THE LATE AFTERNOON HOURS...WHEN DEEPER MOISTURE/LIFT
FROM THE SOUTHERN PLAINS BEGINS MOVING INTO THE AREA. CEILINGS
EXPECTED TO FALL INTO THE 040-050 RANGE BY THEN OVER THE SOUTHERN
TAF SITES. APPEARS SOME LIGHT PRECIPITATION MAY BEGIN AFFECTING
KHUF/KBMG/KIND AFTER ABOUT 252000Z. THICKNESSES SUGGEST
RAIN...HOWEVER THERE IS SOME POTENTIAL FOR SURFACE TEMPERATURES TO
COOL TO FREEZING AT SOME POINT AFTER THE ONSET OF PRECIPITATION...ESPECIALLY
AF KHUF/KIND WHERE PROGGED SURFACE WET BULB TEMPERATURES ARE AT OR
VERY CLOSE TO FREEZING. THIS MAY LEAD TO A PERIOD OF FREEZING RAIN.
SURFACE WINDS UNDER 10 KTS EXPECTED AT THE TAF SITES THROUGH 260000Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...AB/JK
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...JAS/SMF
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1133 AM CST WED JAN 25 2012
.AVIATION...
FOR THE 18Z TAF ISSUANCE...
WITH THE EXCEPTION OF A FEW HIGH CLOUDS...MOSTLY CLEAR SKIES AND
DRY CONDITIONS WILL PREVAIL THIS AFTERNOON THROUGH TOMORROW.
WINDS WILL GENERALLY BE FROM THE NORTH NORTHWEST AROUND 10 KNOTS
INCREASING TO 10 TO 15 KNOTS BEFORE SUNRISE. THE INCREASE IN WIND
IS DUE TO A WEAK COLD FRONT MOVING THROUGH THE AREA.
&&
.PREV DISCUSSION... /ISSUED 536 AM CST WED JAN 25 2012/
SHORT TERM...
AT 00Z WEDNESDAY A 500MB UPPER LOW WAS LOCATED NEAR EL PASO
TEXAS. NORTH OF THIS UPPER LOW A 700MB BAROCLINIC ZONE EXTENDED
ACROSS EASTERN COLORADO. AS OF 6Z THE RUC AND NAM INDICATED THAT THIS
700MB BAROCLINIC WAS CURRENTLY MOVING EAST ACROSS WESTERN KANSAS
WITH SATELLITE LOOP INDICATING WARMING CLOUD TOPS AS THIS
BAROCLINIC ZONE PASSES. CLEAR SKIES HAD ALREADY DEVELOPED WEST OF
THE 500MB DEFORMATION ZONE WHICH AT 06Z WAS STARTING TO CROSS INTO
WESTERN KANSAS. THE LIGHT PRECIPITATION THAT HAD DEVELOPED OVER
PORTIONS OF SOUTH CENTRAL KANSAS EARLIER TONIGHT WILL SLOWLY SHIFT
SOUTHEAST THROUGH THE REMAINDER OF THE MORNING AS THE MID LEVEL
BAROCLINIC ZONE CROSSES INTO SOUTH CENTRAL KANSAS BETWEEN 09Z AND 12Z
WEDNESDAY. CLOUD COVER WILL ALSO GRADUALLY GIVE WAY TO CLEAR SKIES
BY MID DAY IN THE SOUTHEAST AS THE 500MB DEFORMATION EXITS THE
AREA BASED ON 00Z NAM AND 06Z RUC.
THE NAM AND GFS MODEL SOUNDINGS AT 00Z THURSDAY, AS WELL AS ECMWF
6HOUR MAX TEMPERATURE FORECAST WERE ALL SUGGESTING THAT HIGHS
TODAY WILL REBOUND BACK INTO THE LOWER 50S ACROSS WESTERN KANSAS.
IN THE EAST WHERE CLOUDS WILL BE SLOWER TO ERODE THE HIGHS ARE
EXPECTED TO CLIMB TO AROUND 50 BUT IF SKIES CLEAR SOONER IT COULD
BE SEVERAL DEGREES WARMER BASED ON THE 875MB MIX DOWN TEMPERATURE.
TONIGHT A WEAK FRONT WILL MOVE INTO WESTERN KANSAS AS AN UPPER
LEVEL SHORT WAVE TROUGH WHICH WAS ASSOCIATED WITH THE LEFT EXIT
REGION OF A 250MB JET STREAK THAT LOCATED ACROSS WASHINGTON STATE
AT 00Z WEDNESDAY QUICKLY CROSSES THE NORTHERN PLAINS. THE
925-850MB 24HR TEMPERATURE CHANGE FROM 00Z THURSDAY TO 00Z FRIDAY
WAS ONLY A FEW DEGREES OF EACH OTHER SO GIVEN LIMITED CLOUD COVER
EXPECTED THURSDAY AFTERNOON WILL FAVOR HIGHS VERY SIMILAR THOSE
TODAY IN THE WEST. EAST/SOUTHEAST OF DODGE CITY HOWEVER GIVEN MORE
SUN AND BETTER MIXING POTENTIAL THE HIGH SHOULD BE A LITTLE WARMER
BASED ON THE FORECAST 00Z FRIDAY MODEL SOUNDINGS.
LONG TERM /FRIDAY THROUGH WEDNESDAY/
FRIDAY WILL BE BREEZY AT LEAST AND PROBABLY WINDY AS A COLD FRONT
SWEEPS THROUGH THE AREA IN THE MORNING. NORTHWEST FLOW ALOFT WILL BE
INCREASING WITH TIME AS WELL AS THE UPPER JET FROM THE WEST COAST
RIDGE MOVES INTO THE CENTRAL HIGH PLAINS. THE FAST MOVING FRONT
SHOULD BRING A COOLER AIRMASS SOUTHWARD ALONG WITH WEAK FRONTOGENESIS
BUT THE MOISTURE APPEARS RATHER LIMITED. THE BEST QPF FIELDS IN THE
NUMERICAL MODELS LOOK TO BE BETTER ASSOCIATED WITH THE UPPER JET`S
LEFT FRONT EXIT REGION ACROSS THE MISSOURI VALLEY, AND THE BETTER
UPSLOPE FLOW/HIGHER TERRAIN OF EASTERN COLORADO. THEREFORE WE ARE
NOT IMPRESSED WITH PRECIPITATION CHANCES, AND WILL LEAVE THE 20
PERCENT CHANCES FOR RAIN OF FRIDAY ACROSS PORTIONS OF THE FORECAST
AREA. SURFACE HIGH PRESSURE SHOULD THEN DRIFT INTO NORTHERN TEXAS
AND OKLAHOMA ON SATURDAY , WHICH WOULD PRODUCE A LIGHT WESTERLY WIND
FIELD OVER SOUTHWEST KANSAS, AND SIMILAR TEMPERATURES ON BOTH DAYS
IN THE 40S. DUE TO THE LACK OF MOISTURE, THERE DOESN`T APPEAR TO BE
SIGNIFICANT CLOUD COVER DURING THIS PERIOD, BUT WITH THE UPPER JET
BUCKLED ACROSS THE PLAINS, SOME CS MIGHT BE EXPECTED. OVERNIGHT
TEMPERATURES WILL EASILY FALL BELOW FREEZING GIVEN THE COLD 850 MB
TEMPERATURE FIELDS AND THE RELATIVELY LIGHT WINDS. THE SYNOPTIC
PATTERN WILL CHANGE HEADING INTO THE LATER PART OF THE WEEKEND AS
THE UPPER WEST COAST RIDGE PUSHES FARTHER EAST AND THE LEAD UPPER
JET DIVES INTO THE MISSOURI VALLEY. THAT WILL DRAW WARMER AIR FROM
THE HIGHER TERRAIN OF NEW MEXICO AND COLORADO SUNDAY NIGHT AND INTO
MONDAY AND ALLOW TEMPERATURES TO WARM BY ABOUT 10-20 DEGREES DURING
THE DAYTIME HEADING INTO MONDAY AFTERNOON AND ESPECIALLY TUESDAY.
BOTH MODELS PRODUCE A SHORTWAVE TROUGH MOVING THROUGH THE AREA ON
MONDAY, IN A DRY AND STABLE ATMOSPHERE WHICH WILL MAINLY BRING ABOUT
A SURFACE WIND SHIFT DURING THE DAY FROM SOUTHEAST TO NORTHWEST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 27 52 28 45 / 0 0 0 10
GCK 26 51 28 45 / 0 0 0 10
EHA 31 51 28 45 / 0 0 0 10
LBL 28 53 27 48 / 0 0 0 10
HYS 26 52 28 42 / 0 0 10 20
P28 30 55 28 48 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN12/42/42
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
347 PM CST WED JAN 25 2012
.DISCUSSION...
TONIGHT AND THURSDAY...SFC LOW OVER SRN SASKATCHEWAN WILL CONTINUE
TO TRAVERSE EWD OVER LOWER CANADA...BEING USHERED ALONG BY AN
UPPER TROUGH EVENTUALLY BECOMING NEGATIVELY TILTED. A CDFNT
HANGING S FROM THE SFC LOW WILL PUSH THRU THE AREA ARND DAYBREAK
THU MORNING. THE MAIN EFFECTS WILL BE MAINTAINING CLOUD COVER OVER
THE AREA ALONG WITH AN INCREASE IN WIND SPEEDS DUE TO A TIGHTENED
PRESSURE GRADIENT AND ENHANCED LOW- AND MID- LEVEL JETTING.
MOISTURE IS QUITE MEAGER WITH THE FRONT IN SRN MN AND WI /BETTER
MOISTURE OVER NRN MN INTO THE UPPER GREAT LAKES/ SO AM NOT
EXPECTING ANYTHING MORE THAN POSSIBLY FLURRIES SO WILL KEEP THE
FCST DRY OVERNIGHT THRU THU. THERE IS ALSO THE POTENTIAL FOR FOG
IN FAR SRN MN THIS EVENING INTO THE EARLY MRNG HOURS...BUT
ELEVATED WINDS LOOK TO MITIGATE THOSE PROSPECTS. WINDS WILL SHIFT
TO NW BY MIDDAY TMRW AND AS THE FRONT EXITS...SFC HIGH PRES OVER
THE CENTRAL PLAINS WILL NUDGE NWD BY LATE IN THE DAY. THIS WILL
ALLOW FOR PARTIAL CLEARING LATE BUT NOT ENOUGH TO PUSH HIGHS THU
OUT OF THE MID 30S.
THURSDAY NIGHT THROUGH SATURDAY...PROGRESSIVE NWLY FLOW THU NIGHT
INTO FRI WILL DRAG A DEVELOPING COMPACT LOW PRES SYSTEM FROM THE
NRN ROCKIES ACRS THE DAKOTAS AND INTO NRN IA THU NIGHT INTO FRI
MRNG. A SWATH OF DEEPER MOISTURE WILL ACCOMPANY THE SYSTEM AND
INTENSIFY AS IT MEETS UP WITH A REGION OF ENHANCED PV. DEEP COLD
AIR WILL MAKE FOR ANY PRECIP TO BE ALL SNOW...AND WITH GOOD MODEL
AGREEMENT THAT THE PRECIP BANDS WILL BE OVER SRN MN...HAVE NUDGED
UP POPS INTO THE HIGH-END CHC AND LOW-END LIKELY CATEGORY FOR FAR
SRN MN...TRENDING TO SLGT CHC IN CENTRAL MN AND WESTERN WI. QPF/S
APPROACHING A TENTH OF AN INCH WILL PRODUCE 1-2 INCHES OF SNOW
DURING THE DAY ON FRI...PARTICULARLY FRI MORNING AND EARLY
AFTN...OVER SRN MN WITH AMOUNTS TRENDING DOWN GOING N. THE SYSTEM
QUICKLY EXITS TO THE E BY LATE DAY FRI...ALLOWING HIGH PRESSURE TO
MOVE IN FOR FRI NIGHT INTO SAT. THE PATTERN THEN STARTS TO GET A
LITTLE MESSY AS MORE DEVELOPED NW FLOW WILL WILL BRING DOWN WEAK
UPPER LEVEL DISTURBANCES STARTING MIDDAY SAT WHICH MAY BRING
FLURRIES OR LIGHT SNOW SHOWERS TO MAINLY WRN WI AND ERN MN FOR
MID-TO-LATE DAY SATURDAY. POPS ARE ONLY IN THE SLGT CHC RANGE
ATTM. WITH THE STRONGER NW FLOW WILL BE ANOTHER MODEST SURGE OF
ARCTIC AIR TO THE REGION WHICH WILL BUMP HIGHS BACK DOWN TO THE
20S AND LOWS TO THE TEENS AND UPPER SINGLE DIGITS.
SUNDAY THROUGH WEDNESDAY...THE LONGWAVE UPPER TROUGH RESPONSIBLE
FOR THE PRONOUNCED NWLY FLOW OVER THE UPPER MISSISSIPPI RIVER
VALLEY WILL SHIFT E...ALLOWING WESTERN CONUS RIDGING TO MOVE INTO
THE REGION. THIS WILL INITIALLY RESULT IN A WARMING TREND FOR THE
START OF NEXT WEEK...INCLUDING HIGHS REACHING ABOVE FREEZING FOR A
COUPLE OF PERIODS. HOWEVER...AS THE RIDGE FLATTENS...ADDITIONAL
WEAK UPPER DISTURBANCES WILL MOVE IN FROM THE WESTERN STATES. NO
ORGANIZED SYSTEMS ARE APPARENT IN ANY OF THE MODELS ATTM...SO POPS
ARE NO HIGHER THAN 20 PERCENT FOR ANY PERIOD.
&&
.AVIATION.../18Z TAF ISSUANCE/
SEVERAL FACTORS THIS AFTN/EVENING WILL CAUSE EITHER CIGS TO
LOWER...OR REMAIN THE SAME AS THE STRONG INVERSION CONTINUES THIS
AFTN/EVENING ACROSS ALL OF THE FA.
MAIN FORECAST CONCERN DEALS WITH ONGOING MVFR/IFR/LIFR CIGS ACROSS
WESTERN MN...AND IF THEY ADV EASTWARD THIS EVENING.
BASED ON CURRENT LOW LEVEL FLOW BLW 90H...BELIEVE MOST OF THE
LOWER CIGS ACROSS THE WEST WILL REMAIN WEST THRU 00Z...OR UNTIL
THE WNDS BECOME MORE SSW/SW OVERNIGHT WHICH WILL BRING THE LOWER
CIGS ACROSS EASTERN MN/WESTERN WI. AM LEANING TOWARD A MORE
OPTIMISTIC FORECAST FOR MSP/RNH/EAU THIS AFTN...WITH LOWER CIGS
NOT MOVING INTO THIS AREA UNTIL AFT 2Z. CONFIDENCE IS LOW ON ANY
ONE SCENARIO...ESPECIALLY SINCE WE HAVE SOME MELTING OF THE SNOW
ACROSS SC MN THIS AFTN...WHICH WILL LEAD TO A VERY MOISTURE
BOUNDARY LAYER. LATER SHIFTS WILL NEED TO EVALUATE THE EXTENT OF
THE LOWER CIGS TO THE WEST AND IF MORE CIGS DEVELOP THIS
AFTN/EVENING. ONCE THE TROUGH/FRONTAL BOUNDARY MOVES ACROSS THE
AREA LATE TONIGHT/THURSDAY MORNING...EXPECT THE CIGS TO LIFT TO
VFR WITH WNDS BECOMING MORE WNW AND GUSTY BY LATE MORNING.
MSP...VFR CIGS/VSBYS SHOULD CONT THRU 00Z...WITH SOME PROBLEMS
DEVELOPING AFT 00Z...ESPECIALLY DURING THE EVENING AS THE BOUNDARY
LAYER BECOMES VERY MOIST. BASED ON RUC TRENDS AND ANTICIPATED
MOISTURE ADV AND CIGS TO THE WEST...HAVE LOWER CIGS TO MVFR BY
2Z...AND CONTINUING THESE CIGS THRU 9Z OR AS WNDS BECOME MORE
SW/WSW. WNDS WILL LIKELY BECOME GUSTY BY LATE MORNING/AFTN FROM
THE WNW.
FRI...MVFR/IFR CIGS/VSBYS POSSIBLE IN -SN.
SAT...MVFR/IFR CIGS/VSBYS POSSIBLE IN -SN.
SUN/MON...VFR.
TUE...MVFR/IFR CIGS/VSBYS POSSIBLE. ..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JPC/JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1127 AM CST WED JAN 25 2012
.DISCUSSION...
LIGHT SNOW CONTINUES TO SPREAD NORTH AND EAST ACROSS THE CWA EARLY
THIS MORNING...AHEAD OF A SHORT WAVE OVER SOUTHWEST MN. WRF
GUIDANCE SUGGESTS THE SNOW WILL END ACROSS THE FA TOWARDS NOON.
SNOW AMOUNTS OF A HALF INCH TO ONE INCH LIKELY IN THE HIGHER DBZ
BANDING. ALTHOUGH STRONG DRYING IS INDICATED THIS AFTERNOON
ALOFT...LOW LEVEL MOISTURE REMAINS HIGH AND HELD ON TO PLENTY OF
CLOUD COVER. THIS...ALONG SOME NEW SNOW...RESULTED IN TRIMMING THE
HIGHS TODAY BY A FEW DEGREES.
PRETTY GOOD CONTINUITY REMAINS IN THE FORECAST AHEAD AGAIN
TONIGHT WITH A FLURRY OF SHORT WAVE ACTION INTO EARLY NEXT WEEK.
THE WAVE ATTRACTING THE MOST ATTENTION RIGHT NOW IS ONE ON
FRIDAY. SNOW ASSOCIATED WITH THIS FEATURE HAS MIGRATED NORTH AND
SOUTH OVER THE PAST FEW NIGHTS. IT IS NOW BACK NORTH AND ACROSS
MUCH OF SOUTHERN MN FOR FRIDAY. THE ECMWF IS VERY BULLISH ON QPF
AND SNOWFALL. IT WAS QUITE CORRECT MONDAY NIGHT ABOUT THE FORECAST
FOR THIS MORNING...SO MORE WEIGHT OF THE ECMWF WAS USED IN THE
FORECAST FOR FRIDAY. THE NEIGHBORS AGREED AND WE NOW HAVE CHANCE
POPS ALONG AND SOUTH OF THE MN RIVER. THALER QG FROM THE NAM/GFS
FAVOR THE SOUTHERN THIRD OF MN.
COLDER AIR IS STILL ON TAP FOR THE WEEKEND AND SOME LIGHT SNOW
CAN NOT BE RULED OUT ACROSS THE CWA ON SATURDAY. SOME
DISCREPANCIES DO EXIST BETWEEN THE MODELS ON MOISTURE AND TIMING...
WITH THE EASTERN CWA HAVING SOME CHANCE FOR LIGHT SNOW RIGHT NOW.
AREAL COVERAGE AND POPS MAY NEED TO BE EXPANDING WITH TIME.
THE COLD IS SHORT LIVED WITH WAA SETTING IN SUNDAY NIGHT FROM THE
WEST. AGAIN...THERE LOOKS TO BE A PRETTY GOOD CHANCE FOR SNOW
ACROSS NORTHERN MN AND WI AS THE NEXT WAVE MOVES THROUGH.
HENCE...CHANCES FOR SNOW CONTINUE IN THE GRIDS FOR SUNDAY NIGHT
AND MONDAY.
&&
.AVIATION.../18Z TAF ISSUANCE/
SEVERAL FACTORS THIS AFTN/EVENING WILL CAUSE EITHER CIGS TO
LOWER...OR REMAIN THE SAME AS THE STRONG INVERSION CONTINUES THIS
AFTN/EVENING ACROSS ALL OF THE FA.
MAIN FORECAST CONCERN DEALS WITH ONGOING MVFR/IFR/LIFR CIGS ACROSS
WESTERN MN...AND IF THEY ADV EASTWARD THIS EVENING.
BASED ON CURRENT LOW LEVEL FLOW BLW 90H...BELIEVE MOST OF THE
LOWER CIGS ACROSS THE WEST WILL REMAIN WEST THRU 00Z...OR UNTIL
THE WNDS BECOME MORE SSW/SW OVERNIGHT WHICH WILL BRING THE LOWER
CIGS ACROSS EASTERN MN/WESTERN WI. AM LEANING TOWARD A MORE
OPTIMISTIC FORECAST FOR MSP/RNH/EAU THIS AFTN...WITH LOWER CIGS
NOT MOVING INTO THIS AREA UNTIL AFT 2Z. CONFIDENCE IS LOW ON ANY
ONE SCENARIO...ESPECIALLY SINCE WE HAVE SOME MELTING OF THE SNOW
ACROSS SC MN THIS AFTN...WHICH WILL LEAD TO A VERY MOISTURE
BOUNDARY LAYER. LATER SHIFTS WILL NEED TO EVALUATE THE EXTENT OF
THE LOWER CIGS TO THE WEST AND IF MORE CIGS DEVELOP THIS
AFTN/EVENING. ONCE THE TROUGH/FRONTAL BOUNDARY MOVES ACROSS THE
AREA LATE TONIGHT/THURSDAY MORNING...EXPECT THE CIGS TO LIFT TO
VFR WITH WNDS BECOMING MORE WNW AND GUSTY BY LATE MORNING.
MSP...VFR CIGS/VSBYS SHOULD CONT THRU 00Z...WITH SOME PROBLEMS
DEVELOPING AFT 00Z...ESPECIALLY DURING THE EVENING AS THE BOUNDARY
LAYER BECOMES VERY MOIST. BASED ON RUC TRENDS AND ANTICIPATED
MOISTURE ADV AND CIGS TO THE WEST...HAVE LOWER CIGS TO MVFR BY
2Z...AND CONTINUING THESE CIGS THRU 9Z OR AS WNDS BECOME MORE
SW/WSW. WNDS WILL LIKELY BECOME GUSTY BY LATE MORNING/AFTN FROM
THE WNW.
FRI...MVFR/IFR CIGS/VSBYS POSSIBLE IN -SN.
SAT...MVFR/IFR CIGS/VSBYS POSSIBLE IN -SN.
SUN/MON...VFR.
TUE...MVFR/IFR CIGS/VSBYS POSSIBLE. ..JLT..
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
RAH/JLT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1252 PM EST WED JAN 25 2012
.SYNOPSIS...
A COLD FRONT AND LOW PRESSURE WILL APPROACH THE CAROLINAS FROM THE
WEST ON THURSDAY AND PUSH EAST OF THE AREA ON FRIDAY. WEAK HIGH
PRESSURE WILL BUILD IN OVER THE WEEKEND. ANOTHER FRONT WILL BRING
MUCH COOLER AIR TO THE REGION FOR THE FIRST PART OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1245 PM WEDNESDAY... EARLY AFTERNOON UPDATE CONTINUES TRANQUIL
WEATHER FOR THIS AFTERNOON AND TREND OF MORE CLOUDS TONIGHT WITH
INCREASING CHANCE OF SHOWERS IN THE WEST TONIGHT AND ACROSS THE AREA
THURSDAY.
AT 930 AM WEDNESDAY... CLOUDS AND FOG THAT AFFECTED SOUTHERN EDGE OF
CWA EARLIER HAVE JUST ABOUT DISSIPATED. OTHERWISE... THE DAY WILL
CONTINUE AS ADVERTISED IN EARLIER DISCUSSION. THERE WILL BE QUITE A
BIT OF SUNSHINE... BUT THE GRADUAL INCREASE IN CLOUDS WILL OCCUR AS
MOISTURE SPREADS NORTHWARD AND EASTWARD FROM LOW IN THE TX/LA AREA.
AS OF 635 AM WEDNESDAY...AN AREA OF LOW CLOUDS AND FOG CONTINUE TO
SKIRT THE SE PERIPHERY OF THE FORECAST AREA THIS MORNING. HOPEFULLY
IT WILL CONTINUE MOVING SE...BUT THE RUC BNDRY LAYER RH/S IMPLY THAT
IT COULD SPREAD A LITTLE FATHER WEST. WE/LL KEEP AN EYE ON IT.
AS OF 355 AM WEDNESDAY...THE AREA OF DENSE FOG AND LOW CLOUDS HAS
INDEED BEEN PUSHING SLOWLY SOUTHWARD ACROSS THE FA. ACTUALLY...THE
GRIDS HAVE DONE A PRETTY GOOD JOB CAPTURING THIS TREND...AT LEAST
BASED ON WHAT I CAN DISCERN ON THE FOG PRODUCT. THE REST OF THE NEAR
TERM LOOKS GOOD AND ONLY A FEW TWEAKS WERE MADE.
PREVIOUS DISCUSSION...
A BACK DOOR COLD FRONT WILL PUSH ACROSS THE FA EARLY THIS MORNING.
JUST ALONG AND AHEAD OF THE FRONT...AREAS OF FOG AND STRATUS HAVE
DEVELOPED OVER THE SRN NC PIEDMONT AND OVER THE NW PIEDMONT OF SOUTH
CAROLINA. HOWEVER...BUFKIT SOUNDINGS IMPLY THAT DRIER AIR SHOULD MIX
OUT THE FOG AND STRATUS OVER THE NC PIEDMONT IN SHORT ORDER...AND
PUSH IT GRADUALLY SOUTHWARD OVER THE ERN SC UPSTATE. I DON/T THINK
ANY LOW CLOUDS WILL LAST PAST ABOUT 6 AM...AND THEY MAY EVEN MIX OUT
BEFORE THAT. OTHERWISE HIGH CLOUDS WILL GRADUALLY THICKEN AND LOWER
DURING THE COURSE OF THE DAY AS AN UPPER LOW BEGINS TO LIFT OUT
ACROSS THE SRN PLAINS. THERE IS A WELL DEFINED WARM FRONTAL BNDRY
DOWN ALONG THE GULF COAST...AND AS THIS STARTS TO LIFT NORTH IN
RESPONSE TO THE APPROACHING TROUGH...LOW CLOUDS SHOULD SPREAD ACROSS
THE FA LATER TONIGHT. PATCHY AREAS OF RAIN SHOULD ALSO BEGIN TO
DEVELOP...PARTICULARLY ALONG THE SRN AND ERN SLOPES OF THE BLUE
RIDGE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 320 AM WEDNESDAY...LOW LEVEL FLOW WILL CONTINUE TO INCREASE
DURING THE DAY THURSDAY...RESULTING IN GRADUAL INCREASE OF MOISTURE
LEVELS...AS WELL AS IN INCREASE IN ISENTROPIC UPGLIDE AND ESPECIALLY
MECHANICAL/UPSLOPE-INDUCED LIFT. THIS WILL RESULT IN GRADUAL
INCREASE IN POPS THROUGHOUT THE DAY...WITH LIKELY POPS ACROSS THE
SOUTHWEST NC MTNS BY AFTERNOON...EXPANDING TO THE REMAINDER OF THE
NC MTNS BY 00Z FRIDAY...AS DEEP MOISTURE PUSHES INTO THE REGION IN
ADVANCE OF FRONTAL ZONE. THE VERY MOIST FRONTAL ZONE WILL SWEEP
ACROSS THE AREA THURSDAY NIGHT...WARRANTING CATEGORICAL POPS IN ALL
AREAS BY 12Z FRIDAY. PROGGED CAPE VALUES ARE VERY LOW...BUT NON-ZERO
THROUGHOUT THE EVENT...ENOUGH TO WARRANT A SLIGHT CHANCE THUNDER
MENTION IN SOME AREAS. CONSIDERING THE VERY STRONG DEEP-LAYER
SHEAR...A LOW-END SEVERE WEATHER THREAT WILL EXIST...WITH THE
POSSIBILITY OF A DISCRETE CELL OR TWO AHEAD OF THE FRONT THURSDAY
AFTERNOON/EVENING...THEN WITH A POTENTIAL SHALLOW QLCS ALONG THE
FRONT THURSDAY NIGHT.
WEAK LOW PRESSURE DEVELOPING THE FRONT TO OUR SOUTHWEST IS EXPECTED
TO RESULT IN THE BOUNDARY SLOWING DOWN A BIT AS IT PUSHES EAST OF
THE REGION EARLY FRIDAY...SO POPS WILL BE RETAINED ACROSS THE
EASTERN AND SOUTHERN ZONES DURING THE MORNING. OTHERWISE...STRONG
COLD ADVECTION WILL RESULT IN TEMPS FALLING THROUGH THE DAY ACROSS
THE MTNS. NEVERTHELESS...THE POST-FRONTAL AIR MASS IS STILL OF
PACIFIC ORIGINS...SO TEMPS THROUGH THE REMAINDER OF THE SHORT TERM
WILL REMAIN A LITTLE ABOVE NORMAL.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 235 AM WEDNESDAY...THE MEDIUM RANGE BEGINS WITH A VERY BROAD
TROUGH OVER THE EASTERN HALF OF THE COUNTRY. HOWEVER...A STRONG
SHORT WAVE TROUGH DIVING OUT OF THE UPPER MIDWEST SATURDAY NIGHT
WILL SHARPEN THE LONG WAVE PATTERN...BRINGING A COLD FRONT WILL
SIGNIFICANTLY COLDER AIR INTO THE AREA ON SUNDAY. WITH WEAK RIDGING
DOMINATING THE LOW LEVELS ACROSS THE REGION...MOISTURE WILL BE NON
EXISTENT AHEAD OF THIS FRONT...BUT SMALL POPS WILL BE CARRIED ALONG
THE TENN BORDER FOR NW FLOW MOISTURE BEHIND THE FRONT. THE MOST
OBVIOUS IMPACT OF THE FRONT WILL BE TO BRING TEMPERATURES BELOW
CLIMO FOR A COUPLE OF DAYS.
THE LATTER HALF OF THE EXTENDED WILL SEE MODERATING TEMPS...AS THE
EASTERN TROUGH PROGRESSES QUICKLY OFF THE EAST COAST...LEAVING
BEHIND A LOW AMPLITUDE/QUASI-ZONAL FLOW REGIME ACROSS MUCH OF THE
CONUS THROUGH MID-WEEK. THE WEATHER SHOULD ALSO BE DRY FOR A
CHANGE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...CEILING UNLIMITED AND VISIBILITY UNRESTRICTED. VARIABLE
WIND LESS THAN 5 KT WILL FAVOR A SOUTHEAST DIRECTION. AFTER 00Z
BROKEN CEILING NEAR 12K FT LOWERING TO NEAR 4K FT AFTER 06Z AND TO
NEAR 15 HND FT BY 12Z. VISIBILITY NEAR 6 MILES IN HAZE AND FOG
AROUND 12Z.
ELSEWHERE...SCATTERED TO BROKEN MID CLOUDS THIS EVENING WILL LOWER
FROM WEST TO EAST REACHING HEIGHTS 3K TO 5K FT BY 06Z. VISIBILITY
UNRESTRICTED EXCEPT 3 TO 5 MILES IN FOG AND HAZE AROUND 10Z AND RAIN
SHOWERS VICINITY KAVL...KAND...KGSP... AND KGMU BEFORE END OF PERIOD.
OUTLOOK... CONDITIONS SHOULD IMPROVE DURING THE DAY ON
FRIDAY...THOUGH THERE IS A CHANCE THAT CONDITIONS WON/T IMPROVE
UNTIL FRIDAY NIGHT. VFR IS THEN EXPECTED SAT AND SUN.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JDL
NEAR TERM...LGL
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...LGL
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1153 AM CST WED JAN 25 2012
.PREV DISCUSSION... /ISSUED 944 AM CST WED JAN 25 2012/
UPDATE...
SHOWERS ARE MOVING ACROSS NORTHEASTERN ARKANSAS...THE MISSOURI
BOOTHEEL...AND WESTERN TENNESSEE. MODELS ARE SHOWING ADDITIONAL
SHOWERS AND THUNDERSTORMS DEVELOPING OVER NORTHERN MISSISSIPPI AND
SOUTHERN ARKANSAS LATER THIS MORNING AND INTO THE AFTERNOON HOURS.
A LARGE AREA OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED AHEAD OF A
COLD FRONT AND LOW PRESSURE SYSTEM OVER TEXAS AND WILL CONTINUE
MOVING EAST. FORECAST LOOKS GOOD AT THIS TIME AND NO UPDATE IS NEEDED
TO GRIDS.
RRH
&&
.PREV DISCUSSION... /ISSUED 719 AM CST WED JAN 25 2012/
UPDATE...WARM FRONT LOCATED ALONG THE GULF COAST THIS MORNING IS
BEGINNING TO SHOW SIGNS OF MOVING NORTH...AND TOWARDS THE MID
SOUTH LATER TODAY. BASED ON LATEST CONVECTIVE TRENDS AND
THE RUC INDICATING INCREASING ELEVATED INSTABILITY ACROSS THE
FORECAST AREA...INCREASED MENTION OF ELEVATED THUNDER IN THE
FORECAST FOR THE REMAINDER OF THE DAY.
UPDATED GRIDS ALREADY PUBLISHED.
CJC
&&
.PREV DISCUSSION... /ISSUED 456 AM CST WED JAN 25 2012/
DISCUSSION...WATER VAPOR SATELLITE/UPPER AIR PROFILER TRENDS THIS
MORNING PLACE AN UPPER LEVEL LOW NEAR EL PASO TEXAS WITH A SURFACE
LOW CENTERED JUST SOUTHWEST OF SAN ANTONIO TEXAS. A WARM FRONT
EXTENDS FROM THIS SURFACE LOW UP TO WACO TEXAS AND THEN BACK
TOWARDS THE LOUISIANA/ALABAMA COAST AND FLORIDA PANHANDLE. CLOUDY
SKIES AND RAIN ENCOMPASS MUCH OF THE MID SOUTH AS OF THIS
MORNING/S FORECAST ISSUANCE. AS OF 4 AM CST...TEMPERATURES RANGE
FROM THE UPPER 30S TO LOWER 40S ACROSS THE NORTHERN THIRD OF THE
MID SOUTH AND MIDDLE 40S TO AROUND 50 DEGREES ACROSS AREAS SOUTH
OF I-40. THE POTENTIAL FOR A STRONG THUNDERSTORM OR TWO ACROSS
NORTHEAST MISSISSIPPI THURSDAY MORNING INTO EARLY THURSDAY
AFTERNOON IS THE PRIMARY CONCERN IN THIS MORNING/S FORECAST.
SHORT TERM...(TODAY THROUGH THURSDAY)...RAIN HAS FINALLY
ARRIVED OVERNIGHT ACROSS THE MID SOUTH COURTESY OF ISENTROPIC
ASCENT LIFTING GULF OF MEXICO MOISTURE AND PRODUCING OVERRUNNING
RAIN NORTH OF THE WARM FRONT...CURRENTLY SITUATED ALONG THE
LOUISIANA/ALABAMA COAST THIS MORNING. MODELS ARE IN DECENT
AGREEMENT WITH THIS OVERRUNNING RAIN OCCURRING THIS MORNING ACROSS
THE ENTIRE MID SOUTH. THE ABOVE MENTIONED WARM FRONT WILL BEGIN
LIFTING NORTH TODAY...AND REACHING AS FAR NORTH AS PORTIONS OF
NORTHEAST MISSISSIPPI AS EARLY AS LATE AFTERNOON/EARLY THIS
EVENING AS THE UPPER LEVEL LOW AND ASSOCIATED SURFACE LOW BEGIN TO
LIFT NORTHEAST INTO THE LOWER MISSISSIPPI VALLEY. KEPT LOWER POPS
ACROSS NORTHEAST MISSISSIPPI THIS AFTERNOON AS BEST COVERAGE BY
FAR WILL REMAIN NORTH OF THE WARM FRONT. OVERALL INSTABILITY WILL
REMAIN LOW THROUGHOUT THE DAY. HOWEVER...DID ADD ISOLATED THUNDER
FOR THE SOUTHERN TIER OR TWO OF COUNTIES ACROSS NORTH MISSISSIPPI
FOR LATE AFTERNOON AS THE WARM FRONT APPROACHES. HIGH TEMPERATURES
TODAY WILL RANGE FROM THE LOWER TO MIDDLE 40S ACROSS NORTHEAST
ARKANSAS TO FAR NORTHWEST TENNESSEE...AND UPPER 50S TO LOWER 60S
IN CLOSER PROXIMITY TO THE APPROACHING WARM FRONT.
THE WARM FRONT WILL BISECT THE MID SOUTH FROM SOUTHWEST TO
NORTHEAST TONIGHT AS A SURFACE AND UPPER LEVEL LOW MOVE JUST TO
THE SOUTH OF THE FORECAST AREA INTO THURSDAY. SHOWERS AND A FEW
THUNDERSTORMS ARE EXPECTED ACROSS THE MID SOUTH TONIGHT INTO
THURSDAY. DESPITE FAVORABLE UPPER LEVEL DIVERGENCE /LIFT/ AND
SHEAR...NOT OVERLY IMPRESSED WITH QUALITY OF INSTABILITY FORECAST
ACROSS THE MID SOUTH. BEST INSTABILITY AXIS WILL REMAIN JUST TO
THE SOUTH OF THE AREA AND WIDESPREAD RAIN SHOWERS/EXTENSIVE CLOUD
COVER HAVE RESULTED IN LOW CONFIDENCE ON STRONG/SEVERE
THUNDERSTORM THREAT DURING THIS TIME FRAME. NONETHELESS...DAY/EVENING
SHIFTS WILL CONTINUE TO MONITOR TRENDS AND ADJUST FORECAST AS NECESSARY
IF THIS INSTABILITY AXIS CREEPS FURTHER NORTH THAN CURRENTLY
INDICATED BY THE LATEST SHORT TERM MODELS.
LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)...
RAIN SHOWERS WILL GRADUALLY COME TO AN END THURSDAY NIGHT AS COOL HIGH
PRESSURE BUILDS BACK INTO THE MID SOUTH BY FRIDAY MORNING. MODELS
INDICATE ANOTHER COLD FRONT WILL MOVE INTO THE AREA FRIDAY NIGHT.
HOWEVER...ANALYSIS OF MODEL SOUNDINGS INDICATES LOW LEVEL
PRECIPITATION WILL REMAIN NEARLY NON-EXISTENT AND WILL RESULT IN
SOME MID/HIGH LEVEL CLOUDS PUSHING ACROSS THE AREA FRIDAY NIGHT
INTO SATURDAY MORNING. 00Z GFS/ECMWF LONG TERM MODELS INDICATE
SURFACE HIGH PRESSURE WILL BUILD BACK IN AGAIN ACROSS THE LOWER
MISSISSIPPI VALLEY SATURDAY THROUGH MONDAY WITH CYCLONIC FLOW
ALOFT. CHANCES FOR RAIN SHOWERS WILL RETURN BY NEXT TUESDAY AS
HIGH PRESSURE MOVES EAST AND ANOTHER COLD FRONT BEGINS TO MOVE
FROM THE CENTRAL/SOUTHERN PLAINS INTO THE MIDDLE/LOWER MISSISSIPPI
VALLEYS BY THE MIDDLE OF NEXT WEEK.
CJC
&&
.AVIATION...
18Z TAF CYCLE
RAIN HAS PUSHED NORTH AND IS NOW CONFINED TO NORTHWEST TENNESSEE
AND NORTHERN ARKANSAS. CLEARING HAS TAKEN PLACE ACROSS NORTHEAST
MISSISSIPPI WITH VARYING CONDITIONS BETWEEN VFR AND MVFR IN
CLOUD PATCHES. THINK THE CURRENT TREND WILL CONTINUE FOR THE REST
OF THE AFTERNOON. BY THIS EVENING...CLOUDS SHOULD FILL IN AND LOWER
AGAIN WITH RAIN REDEVELOPING AREAWIDE. A FEW THUNDERSTORMS ARE
ALSO POSSIBLE...PARTICULARLY ALONG AND SOUTH OF I-40. IFR
CONDITIONS OR LIFR CONDITIONS SHOULD OVERSPREAD PARTS OF THE AREA
LATE TONIGHT AND THURSDAY MORNING.
WINDS WILL BE SOUTHERLY SOUTH OF I-40...AND EASTERLY OR NORTHEASTERLY
ALONG AND NORTH. AS THE LOW BISECTS THE AREA THURSDAY MORNING...WINDS
WILL BACK NORTH.
BORGHOFF
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 55 53 60 39 / 90 100 100 50
MKL 52 49 59 38 / 100 90 100 50
JBR 46 44 49 35 / 100 100 100 30
TUP 62 57 69 42 / 70 80 100 70
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1147 AM CST WED JAN 25 2012
.DISCUSSION...
LINE OF THUNDERSTORMS FROM NEAR LFK TO IAH TO SGR TO FREEPORT
MOVING EAST AT 25-35 KNOTS WITH INDIVIDUAL STORMS MOVING
NORTHEAST. LLJ AHEAD OF THE BOUNDARY AIDING SE SFC WINDS
15-25KTS. STORMS WILL USHER IN WINDS OF 15 TO 40 KNOTS STRONGER IN
EMBEDDED BOWS AND NOTCHES. BACK EDGE OF STORM CLEARING CLL ATTM
AND SHOULD CLEAR ALL THE SITES BUT GLS BY 20Z. WINDS IN THE WAKE
OF THE STORMS SWINGING TO THE NW BUT WINDS LOOK TO BE LIGHTER THAN
WITH THE PASSAGE OF THE MESOL-LOW EARLIER THIS AM. CIGS DROPPING
TO AROUND 1000-2000 FT BKN/OVC WITH WRAP AROUND. VCSH POSSIBLE
LATE TONIGHT EARLY AM WITH THE UPPER TROUGH PASSAGE BUT MOISTURE
MAY BE LACKING AND MAY JUST BE MID LEVEL CLOUDS AND VIRGA.
WESTERLY WINDS TOMORROW WITH CIGS IMPROVING TO VFR.
45
&&
.PREV DISCUSSION... /ISSUED 1049 AM CST WED JAN 25 2012/
DISCUSSION...
DID A QUICK UPDATE TO CANCEL THE TORNADO WATCH OUT WEST AND EXTEND IT
UNTIL 2 PM OUT EAST. BASED ON CURRENT RADAR TRENDS...RAISED GRID RAINFALL
TOTALS. 42
PREV DISCUSSION... /ISSUED 1001 AM CST WED JAN 25 2012/
DISCUSSION...
LINE OF STRONG/SEVERE THUNDERSTORMS MAKING PROGRESS MOVING EASTWARD
ACROSS SOUTHEAST TEXAS THIS MORNING WITH A TORNADO WATCH IN EFFECT
UNTIL 11 AM. NORTHERN HALF OF THE LINE (ROUGHLY NORTH OF I-10) IS
MOVING FASTER THAN THE SOUTHERN HALF OF THE LINE. WE WILL PROBABLY
BE ISSUING ADDITIONAL FLOOD ADVISORIES TO COVER THE POTENTIAL FOR
WIDESPREAD 1 TO 3 INCH RAINFALL TOTALS ACROSS THE SOUTHERN HALF OF
THIS STORM COMPLEX...AND THIS AREA WILL ALSO BE CLOSELY MONITORED FOR
THE POTENTIAL FOR SEVERE STORM DEVELOPMENT. HIGHER RAINFALL TOTALS
CANNOT BE RULED OUT.
UPDATED THE MORNING FORECAST WITH HIGHER RAIN CHANCES EAST AND COOLER
TEMPERATURES WEST. 42
PREV DISCUSSION... /ISSUED 738 AM CST WED JAN 25 2012/
UPDATE...
EXTENDED THE TORNADO WATCH INTO CHAMBERS...LIBERTY...SAN JACINTO
COUNTIES...AND GALVESTON BAY.
PREV DISCUSSION... /ISSUED 634 AM CST WED JAN 25 2012/
AVIATION...
MAIN AVIATION CONCERN WILL BE PERIODS OF HEAVY RAINFALL LIMITING
VISBIES (MVFR) AND WIND GUSTS THAT COULD EXCEED 35 KTS WITHIN STRONGEST
STORMS. IN THE MEANTIME...A 50 KT LL JET HAS SHORT TERM WIND SHEAR
IN CURRENT PACKAGE...OR BEFORE THUNDERSTORMS ARRIVE. TIMING HAS THE
BULK OF CONVECTION OVER THE GREATER HOUSTON TERMINALS DURING THE
16-20Z TIME FRAME...PERIODS OF SCATTERED SHOWERS WITH AN EMBEDDED
STORM BOOK-ENDING THOSE TIMES. PRECIP BEGINNING TO FILL IN NICELY
AHEAD OF ONE-OF-TWO MAIN SQUALL LINES MOVING NE FROM SOUTH CENTRAL
TEXAS. THIS 50 KT LOW LEVEL JET AND AMPLE INFLOW INTO THE APPROACHING
MID-SURFACE LOW (NEAR KSAT) WILL AID IN KEEPING THE MAJORITY OF
THE DECKS AT IFR OR MVFR LEVELS...MORNING 20-25 SUSTAINED WINDS.
LINGERING -SHRA THROUGH EVENING AS THE SURFACE LOW PASSES EAST...WRAP
AROUND -RA THROUGH LATE EVENING WITH OVERCAST DECKS THROUGH REMAINDER
OF PERIOD UNDER WESTERLY FLOW. 31
PREV DISCUSSION... /ISSUED 540 AM CST WED JAN 25 2012/
UPDATE...
UPDATE FOR STRONGER WINDS THAN EARLIER EXPECTED. SUSTAINED 20 TO
25 MPH HAVE DEVELOPED AHEAD OF THE STORMS MOVING TOWARD THE
WESTERN COUNTIES OF THE FORECAST AREA. 09Z RUC INITIALIZED WELL
WITH THE WINDS. THE STRONGER WINDS WILL DIMINISH BY MIDDAY. WIND
ADVISORY OUT THROUGH NOON.
PREV DISCUSSION... /ISSUED 422 AM CST WED JAN 25 2012/
DISCUSSION...
SEVERE THUNDERSTORMS WITH DAMAGING WIND GUSTS AND ISOLATED
TORNADOES ARE A THREAT TODAY AS A STRONG STRONG STORM SYSTEM MOVES
ACROSS THE STATE. AT 3 AM THE UPPER LOW WAS LOCATED NEAR THE BIG
BEND AND A LARGE AREA OF THUNDERSTORMS WAS ALREADY AFFECTING THE
HILL COUNTRY. SE TX WAS UNDER THE STRONG INFLOW INTO THE SYSTEM
AND THE AIR MASS OVERHEAD WILL CONTINUE TO DESTABILIZE THIS
MORNING. THE STORM PREDICTION CENTER HAS ALREADY ISSUED A TORNADO
WATCH FOR MOST OF THE FORECAST AREA THROUGH 11 AM. AM EXPECTING
THAT THUNDERSTORMS WILL BEGIN AFFECTING LOCATIONS ALONG AND WEST
OF A LINE FROM COLLEGE STATION TO COLUMBUS BETWEEN 4 AND 6 AM...
AND THEN THE REMAINING AREAS ALONG AND WEST OF INTERSTATE 45 BY
MID MORNING.
THE MODELS WERE SIMILAR IN HOW THEY HANDLED THE MOVEMENT OF THE
UPPER LOW AND SURFACE FEATURES. EXPECT THE UPPER LOW TO SWING
EASTWARD THROUGH THE BIG BEND AREA THIS MORNING BEFORE HEADING TO
THE NORTHEAST THROUGH CENTRAL TEXAS TONIGHT. THE SURFACE FRONT
WILL BE RATHER SLOW TO MOVE EASTWARD AND LOCALLY HEAVY RAINFALL
IS LIKELY. THE PW/S REACH TO 1.7 INCHES...THE MAXIMUM HISTORICALLY
FOR THE END OF JANUARY AND ABOVE 2 STANDARD DEVIATIONS FROM
NORMAL. WILL WATCH THE MOVEMENT OF THE AREA OF THUNDERSTORMS
PUSHING EAST OF INTERSTATE 35 TO SEE IF ANY TRAINING OF STORMS
DEVELOP. MAY CONSIDER A FLOOD WATCH LATER THIS MORNING FOR THE
WESTERN COUNTIES OF THE FORECAST AREA IF THE LINE DOES NOT BEGIN
TO MOVE FASTER TO THE EAST.
THE COLD FRONT WILL BE A BIT SLOWER TO EXIT THROUGH SE TX THAN
EARLIER THOUGHT. THE CHANCES FOR STRONGER THUNDERSTORMS WITH
LOCALLY HEAVY RAINFALL WILL LINGER INTO THE MID AND LATE AFTERNOON
FOR LOCATIONS EAST OF INTERSTATE 45. WRAP AROUND MOISTURE WILL
THEN AFFECT THE FORECAST AREA TONIGHT AND THURSDAY AS THE UPPER
LOW MOVES ACROSS CENTRAL AND NORTH TEXAS.
FAIR AND COOLER WEATHER IS THEN IN STORE FOR THE REST OF THE
PERIOD. ANOTHER WEAK FRONT MOVES THROUGH ON SUNDAY BUT IT APPEARS
TO BE DRY FOR NOW AND WILL JUST REINFORCE THE COOL AND DRY AIR
OVERHEAD.
MARINE...
SMALL CRAFT ADVISORY IN EFFECT FOR ALL WATERS AS AN APPROACHING
STORM SYSTEM WILL INTRODUCE SOUTH-TO-NORTH MOVING BANDS OF HEAVY
RAINFALL AND STRONG THUNDERSTORMS WITHIN POCKETS OF RAIN SHOWERS.
ROBUST ONSHORE WINDS JUST UPSTREAM OF THE SURFACE TROUGH...WEAKENING
AS THE TROUGH NEARS AND PASSES EAST...THEN TURNING MODERATE OFFSHORE
LATTER THURSDAY WITHIN A TIGHT BACKSIDE GRADIENT. LOCAL BAY WATERS
WILL BE CHURNED UP WITH NEARSHORE 4 TO 5 FOOT SEA HEIGHTS...AS HIGH
AS 7 TO 8 FEET (WITH A SHORTER PERIOD) FURTHER OFFSHORE. IN THE
MEANTIME...MARINERS SHOULD CLOSELY MONITOR THE RADAR AND CURRENT
OBSERVATIONS THROUGH THE DAY AS WEATHER COULD QUICKLY TURN ROUGH
WITH ANY PASSING MARITIME STORM. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 63 48 60 42 63 / 100 30 30 10 10
HOUSTON (IAH) 72 52 63 45 65 / 100 40 20 10 10
GALVESTON (GLS) 72 55 64 50 62 / 100 50 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
JACKSON...LIBERTY...MADISON...MATAGORDA...MONTGOMERY...SAN
JACINTO...WALKER...WALLER...WASHINGTON...WHARTON.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...42
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1049 AM CST WED JAN 25 2012
.DISCUSSION...
DID A QUICK UPDATE TO CANCEL THE TORNADO WATCH OUT WEST AND EXTEND IT
UNTIL 2 PM OUT EAST. BASED ON CURRENT RADAR TRENDS...RAISED GRID RAINFALL
TOTALS. 42
&&
.PREV DISCUSSION... /ISSUED 1001 AM CST WED JAN 25 2012/
DISCUSSION...
LINE OF STRONG/SEVERE THUNDERSTORMS MAKING PROGRESS MOVING EASTWARD
ACROSS SOUTHEAST TEXAS THIS MORNING WITH A TORNADO WATCH IN EFFECT
UNTIL 11 AM. NORTHERN HALF OF THE LINE (ROUGHLY NORTH OF I-10) IS
MOVING FASTER THAN THE SOUTHERN HALF OF THE LINE. WE WILL PROBABLY
BE ISSUING ADDITIONAL FLOOD ADVISORIES TO COVER THE POTENTIAL FOR
WIDESPREAD 1 TO 3 INCH RAINFALL TOTALS ACROSS THE SOUTHERN HALF OF
THIS STORM COMPLEX...AND THIS AREA WILL ALSO BE CLOSELY MONITORED FOR
THE POTENTIAL FOR SEVERE STORM DEVELOPMENT. HIGHER RAINFALL TOTALS
CANNOT BE RULED OUT.
UPDATED THE MORNING FORECAST WITH HIGHER RAIN CHANCES EAST AND COOLER
TEMPERATURES WEST. 42
PREV DISCUSSION... /ISSUED 738 AM CST WED JAN 25 2012/
UPDATE...
EXTENDED THE TORNADO WATCH INTO CHAMBERS...LIBERTY...SAN JACINTO
COUNTIES...AND GALVESTON BAY.
PREV DISCUSSION... /ISSUED 634 AM CST WED JAN 25 2012/
AVIATION...
MAIN AVIATION CONCERN WILL BE PERIODS OF HEAVY RAINFALL LIMITING
VISBIES (MVFR) AND WIND GUSTS THAT COULD EXCEED 35 KTS WITHIN STRONGEST
STORMS. IN THE MEANTIME...A 50 KT LL JET HAS SHORT TERM WIND SHEAR
IN CURRENT PACKAGE...OR BEFORE THUNDERSTORMS ARRIVE. TIMING HAS THE
BULK OF CONVECTION OVER THE GREATER HOUSTON TERMINALS DURING THE
16-20Z TIME FRAME...PERIODS OF SCATTERED SHOWERS WITH AN EMBEDDED
STORM BOOK-ENDING THOSE TIMES. PRECIP BEGINNING TO FILL IN NICELY
AHEAD OF ONE-OF-TWO MAIN SQUALL LINES MOVING NE FROM SOUTH CENTRAL
TEXAS. THIS 50 KT LOW LEVEL JET AND AMPLE INFLOW INTO THE APPROACHING
MID-SURFACE LOW (NEAR KSAT) WILL AID IN KEEPING THE MAJORITY OF
THE DECKS AT IFR OR MVFR LEVELS...MORNING 20-25 SUSTAINED WINDS.
LINGERING -SHRA THROUGH EVENING AS THE SURFACE LOW PASSES EAST...WRAP
AROUND -RA THROUGH LATE EVENING WITH OVERCAST DECKS THROUGH REMAINDER
OF PERIOD UNDER WESTERLY FLOW. 31
PREV DISCUSSION... /ISSUED 540 AM CST WED JAN 25 2012/
UPDATE...
UPDATE FOR STRONGER WINDS THAN EARLIER EXPECTED. SUSTAINED 20 TO
25 MPH HAVE DEVELOPED AHEAD OF THE STORMS MOVING TOWARD THE
WESTERN COUNTIES OF THE FORECAST AREA. 09Z RUC INITIALIZED WELL
WITH THE WINDS. THE STRONGER WINDS WILL DIMINISH BY MIDDAY. WIND
ADVISORY OUT THROUGH NOON.
PREV DISCUSSION... /ISSUED 422 AM CST WED JAN 25 2012/
DISCUSSION...
SEVERE THUNDERSTORMS WITH DAMAGING WIND GUSTS AND ISOLATED
TORNADOES ARE A THREAT TODAY AS A STRONG STRONG STORM SYSTEM MOVES
ACROSS THE STATE. AT 3 AM THE UPPER LOW WAS LOCATED NEAR THE BIG
BEND AND A LARGE AREA OF THUNDERSTORMS WAS ALREADY AFFECTING THE
HILL COUNTRY. SE TX WAS UNDER THE STRONG INFLOW INTO THE SYSTEM
AND THE AIR MASS OVERHEAD WILL CONTINUE TO DESTABILIZE THIS
MORNING. THE STORM PREDICTION CENTER HAS ALREADY ISSUED A TORNADO
WATCH FOR MOST OF THE FORECAST AREA THROUGH 11 AM. AM EXPECTING
THAT THUNDERSTORMS WILL BEGIN AFFECTING LOCATIONS ALONG AND WEST
OF A LINE FROM COLLEGE STATION TO COLUMBUS BETWEEN 4 AND 6 AM...
AND THEN THE REMAINING AREAS ALONG AND WEST OF INTERSTATE 45 BY
MID MORNING.
THE MODELS WERE SIMILAR IN HOW THEY HANDLED THE MOVEMENT OF THE
UPPER LOW AND SURFACE FEATURES. EXPECT THE UPPER LOW TO SWING
EASTWARD THROUGH THE BIG BEND AREA THIS MORNING BEFORE HEADING TO
THE NORTHEAST THROUGH CENTRAL TEXAS TONIGHT. THE SURFACE FRONT
WILL BE RATHER SLOW TO MOVE EASTWARD AND LOCALLY HEAVY RAINFALL
IS LIKELY. THE PW/S REACH TO 1.7 INCHES...THE MAXIMUM HISTORICALLY
FOR THE END OF JANUARY AND ABOVE 2 STANDARD DEVIATIONS FROM
NORMAL. WILL WATCH THE MOVEMENT OF THE AREA OF THUNDERSTORMS
PUSHING EAST OF INTERSTATE 35 TO SEE IF ANY TRAINING OF STORMS
DEVELOP. MAY CONSIDER A FLOOD WATCH LATER THIS MORNING FOR THE
WESTERN COUNTIES OF THE FORECAST AREA IF THE LINE DOES NOT BEGIN
TO MOVE FASTER TO THE EAST.
THE COLD FRONT WILL BE A BIT SLOWER TO EXIT THROUGH SE TX THAN
EARLIER THOUGHT. THE CHANCES FOR STRONGER THUNDERSTORMS WITH
LOCALLY HEAVY RAINFALL WILL LINGER INTO THE MID AND LATE AFTERNOON
FOR LOCATIONS EAST OF INTERSTATE 45. WRAP AROUND MOISTURE WILL
THEN AFFECT THE FORECAST AREA TONIGHT AND THURSDAY AS THE UPPER
LOW MOVES ACROSS CENTRAL AND NORTH TEXAS.
FAIR AND COOLER WEATHER IS THEN IN STORE FOR THE REST OF THE
PERIOD. ANOTHER WEAK FRONT MOVES THROUGH ON SUNDAY BUT IT APPEARS
TO BE DRY FOR NOW AND WILL JUST REINFORCE THE COOL AND DRY AIR
OVERHEAD.
MARINE...
SMALL CRAFT ADVISORY IN EFFECT FOR ALL WATERS AS AN APPROACHING
STORM SYSTEM WILL INTRODUCE SOUTH-TO-NORTH MOVING BANDS OF HEAVY
RAINFALL AND STRONG THUNDERSTORMS WITHIN POCKETS OF RAIN SHOWERS.
ROBUST ONSHORE WINDS JUST UPSTREAM OF THE SURFACE TROUGH...WEAKENING
AS THE TROUGH NEARS AND PASSES EAST...THEN TURNING MODERATE OFFSHORE
LATTER THURSDAY WITHIN A TIGHT BACKSIDE GRADIENT. LOCAL BAY WATERS
WILL BE CHURNED UP WITH NEARSHORE 4 TO 5 FOOT SEA HEIGHTS...AS HIGH
AS 7 TO 8 FEET (WITH A SHORTER PERIOD) FURTHER OFFSHORE. IN THE
MEANTIME...MARINERS SHOULD CLOSELY MONITOR THE RADAR AND CURRENT
OBSERVATIONS THROUGH THE DAY AS WEATHER COULD QUICKLY TURN ROUGH
WITH ANY PASSING MARITIME STORM. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 63 48 60 42 63 / 100 30 30 10 10
HOUSTON (IAH) 72 52 63 45 65 / 100 40 20 10 10
GALVESTON (GLS) 72 55 64 50 62 / 100 50 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
JACKSON...LIBERTY...MADISON...MATAGORDA...MONTGOMERY...SAN
JACINTO...WALKER...WALLER...WASHINGTON...WHARTON.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...42
AVIATION/MARINE...45