Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/22/14
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1152 PM MST WED FEB 19 2014
.UPDATE...
ISSUED AT 1151 PM MST WED FEB 19 2014
LOADED LATEST OBSERVATIONS AND BLENDED TO REST OF FORECAST.
ALSO...ADJUSTED PRECIP COVERAGE TO REFLECT CURRENT RADAR.
NO OTHER UPDATES AT THIS TIME. LW
UPDATE ISSUED AT 850 PM MST WED FEB 19 2014
ADDING SNOW/BLOWING SNOW ADVISORY TO TELLER/NORTHERN EL PASO COUNTIES
FOR THE REST OF TONIGHT...BASED ON RADAR/SATELLITE TRENDS AND HI RES
MODEL FORECASTS FOR THE REMAINDER OF THE NIGHT. HRRR DEVELOPS GOOD
PERIOD OF SNOW/BLOWING SNOW ACROSS TELLER/MAINLY NORTHERN EL PASO
COUNTIES SHORTLY AND THEN CONTINUING FOR SEVERAL HOURS BEFORE
ENDING. ADVISORY AND UPDATED PRODUCTS WILL BE OUT SHORTLY. LW
UPDATE ISSUED AT 701 PM MST WED FEB 19 2014
LOADED LATEST OBSERVATIONS AND BLENDED INTO FORECAST. ADJUSTED
SKY COVER AND PRECIP GRIDS TO REFLECT LATEST RADAR AND SATELLITE
TRENDS...AS WELL AS SHORT TERM HI RES MODEL FORECASTS. LW
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 333 PM MST WED FEB 19 2014
STRONG UPPER TROUGH MOVING QUICKLY EASTWARD THROUGH THE GREAT BASIN
INTO WESTERN COLORADO THIS AFTERNOON...WITH SNOW DEVELOPING AND EVEN
A COUPLE LIGHTNING STRIKES WEST OF THE CONTINENTAL DIVIDE THIS
AFTERNOON. EXPECT SNOW TO BEGIN BY SUNSET OVER THE CENTRAL AND
SOUTHWEST MOUNTAINS...WITH A PERIOD OF HEAVY SNOW AND BLOWING SNOW
OVERNIGHT...ESPECIALLY FROM MONARCH PASS NORTHWARD. CURRENT SNOWFALL
FORECAST IN THE 5 TO 9 INCH RANGE LOOKS ON TRACK...HIGHEST AMOUNTS
LIKELY NORTH OF COTTONWOOD PASS. SURFACE COLD FRONT DROPPING
QUICKLY SOUTH THROUGH WYOMING AS OF 22Z...AND WILL MOVE RAPIDLY
SOUTH ACROSS EASTERN COLORADO THIS EVENING. NORTH WINDS FOLLOWING
THE FROPA WILL GUST IN THE 45-55 MPH RANGE...AS STRONG SURFACE
PRESSURE RISE CENTER DROPS INTO THE REGION 06-09Z. MAY BE A QUICK
BURST OF -SHRA/-SHSN BEHIND THE FRONT OVER THE EASTERN MOUNTAINS AND
PLAINS...WITH THE BEST CHANCE OF PRECIP NORTH OF THE ARKANSAS RIVER
AND EAST OF THE I-25 CORRIDOR. NOT LOOKING FOR MUCH IF ANY
ACCUMULATING SNOW...THOUGH VISIBILITY COULD FALL BELOW A MILE
FOR A BRIEF PERIOD UNDER THE HEAVIER SHOWERS. ANY PRECIP WILL
QUICKLY EXIT THE AREA THURSDAY MORNING...AND ONLY A FEW -SHSN WILL
BE FOUND LINGERING OVER THE CENTRAL MOUNTAINS BY AFTERNOON. STRONG
N-NW WINDS WILL CONTINUE MOST LOCATIONS THROUGH THE DAY...THOUGH
I-25 CORRIDOR WILL LIKELY SEE SOME DECREASE IN SPEEDS BY MID/LATE
AFTERNOON. MODEL RH FORECASTS KEEP ALL OF THE PLAINS ABOVE 15
PERCENT THRESHOLD FOR A FIRE WX HIGHLIGHT...BUT GIVEN ATROCIOUS
DEWPOINT FORECASTS OF LATE...EXPECT DRIEST AREAS ALONG THE NM BORDER
TO BECOME DRY ENOUGH TO WARRANT A RED FLAG WARNING...WHILE AREA
FARTHER NORTH LOOKS TOO COOL TO FORCE RH LOW ENOUGH. MAX TEMPS MOST
LOCATIONS SHOULD FALL 15-20F VERSUS WED MAXES.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 333 PM MST WED FEB 19 2014
THURSDAY NIGHT AND FRIDAY...BRISK NW FLOW ALOFT WILL KEEP SCATTERED
OR EVEN LIKELY POPS FOR THE CENTRAL MTS IN PLACE THROUGH THU
NIGHT...THEN AS THE FLOW SHIFTS TO A MORE WESTERLY DIRECTION PCPN
CHANCES ARE EXPECTED TO DROP OFF THROUGH FRI. STRONG DOWNSLOPE FLOW
IS FORECAST TO BOOST MAX TEMPS FOR THE PLAINS INTO THE MID 50S TO
AROUND 60 F. GFS AND EC MODELS PAINT A COLD FRONT DROPPING DOWN THE
EASTERN HALF OF THE STATE LATE FRI EVE. THIS WILL SET UP THE REGION
FOR A COOLER SAT.
SATURDAY AND SUNDAY...A REINFORCING PUSH OF LLVL UPSLOPE FLOW WILL
KEEP COOLER AIR IN PLACE FOR THE PLAINS...AS WELL AS BRING ISOLATED
SNOW POPS TO THE PALMER DVD AND FAR EASTERN PLAINS BY SAT AFTN AND
EVE. MEANWHILE...ISOLATED TO SCATTERED POPS CONTINUE FOR THE CENTRAL
MTS. FOR SUN...THE COOL AIR REMAINS IN PLACE FOR MAC TEMPS IN THE
30S AND 40S FOR THE CWA...BUT IT LOOKS LIKE IT MIGHT REMAIN DRY FOR
ALL AREAS WITH WESTERLY FLOW ALOFT.
MONDAY THROUGH WEDNESDAY...NW FLOW ALOFT CONTINUES WITH A CONTINUED
ISOLATED THREAT OF SNOW FOR THE CENTRAL MTS. MODELS ARE INDICATING A
DRY COLD FRONT MONDAY EVE WHICH WOULD COOL MAX TEMPS FOR TUE.
OTHERWISE...ISOLATED SNOW FOR THE HIGHER ELEVATIONS OF LAKE AND
CHAFFEE COUNTIES...WHILE DRY AND WARMER FOR THE REMAINDER OF THE
FORECAST AREA. MOORE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1019 PM MST WED FEB 19 2014
MAIN CONCERN WILL BE SN SHWRS...WHICH WILL BE THE MOST WIDESPREAD
OVR THE NEXT FEW HOURS...AND COULD RESULT IN BRIEF IFR CONDITIONS
ESPECIALLY THRU 09Z. BANDED SN SHWRS WILL MOVE TO THE S WITH THE
COLD FRONT THRU THU MORNING...SO EXPECT IMPROVING CONDITIONS AT
KCOS AFTER 09-10Z AND AT KPUB AN HOUR OR TWO LATER. ONLY SPOTTY
ISOLD SHWRS EXPECTED AT ALS...WHICH SHOULD BE VFR FOR THU.
COULD BE A FEW SHOWERS AND LOCALIZED LOW CIGS THRU ABOUT 12Z E OF
THE MTS. WINDS WILL CONTINUE TO GUST FROM THE N TO NW BEHIND THE
FRONT. THERE COULD BE A BRIEF LULL IN THE WINDS EARLY THU...BUT WINDS
SHOULD INCREASE AGAIN FROM THE NW IN THE 16Z TO 23Z TIME FRAME...AND
THERE COULD BE A FEW GUSTS IN THE 40 KT RANGE DURING THIS TIME.
WINDS WILL RELAX THU EVENING. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM MST THURSDAY FOR COZ081-082-
084.
RED FLAG WARNING FROM 11 AM TO 6 PM MST THURSDAY FOR COZ229-230-
233-237.
WINTER WEATHER ADVISORY UNTIL 8 AM MST THURSDAY FOR COZ058-060.
&&
$$
UPDATE...LW
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1026 PM MST WED FEB 19 2014
.UPDATE...
ISSUED AT 850 PM MST WED FEB 19 2014
ADDING SNOW/BLOWING SNOW ADVISORY TO TELLER/NORTHERN EL PASO COUNTIES
FOR THE REST OF TONIGHT...BASED ON RADAR/SATELLITE TRENDS AND HI RES
MODEL FORECASTS FOR THE REMAINDER OF THE NIGHT. HRRR DEVELOPS GOOD
PERIOD OF SNOW/BLOWING SNOW ACROSS TELLER/MAINLY NORTHERN EL PASO
COUNTIES SHORTLY AND THEN CONTINUING FOR SEVERAL HOURS BEFORE
ENDING. ADVISORY AND UPDATED PRODUCTS WILL BE OUT SHORTLY. LW
UPDATE ISSUED AT 701 PM MST WED FEB 19 2014
LOADED LATEST OBSERVATIONS AND BLENDED INTO FORECAST. ADJUSTED
SKY COVER AND PRECIP GRIDS TO REFLECT LATEST RADAR AND SATELLITE
TRENDS...AS WELL AS SHORT TERM HI RES MODEL FORECASTS. LW
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 333 PM MST WED FEB 19 2014
STRONG UPPER TROUGH MOVING QUICKLY EASTWARD THROUGH THE GREAT BASIN
INTO WESTERN COLORADO THIS AFTERNOON...WITH SNOW DEVELOPING AND EVEN
A COUPLE LIGHTNING STRIKES WEST OF THE CONTINENTAL DIVIDE THIS
AFTERNOON. EXPECT SNOW TO BEGIN BY SUNSET OVER THE CENTRAL AND
SOUTHWEST MOUNTAINS...WITH A PERIOD OF HEAVY SNOW AND BLOWING SNOW
OVERNIGHT...ESPECIALLY FROM MONARCH PASS NORTHWARD. CURRENT SNOWFALL
FORECAST IN THE 5 TO 9 INCH RANGE LOOKS ON TRACK...HIGHEST AMOUNTS
LIKELY NORTH OF COTTONWOOD PASS. SURFACE COLD FRONT DROPPING
QUICKLY SOUTH THROUGH WYOMING AS OF 22Z...AND WILL MOVE RAPIDLY
SOUTH ACROSS EASTERN COLORADO THIS EVENING. NORTH WINDS FOLLOWING
THE FROPA WILL GUST IN THE 45-55 MPH RANGE...AS STRONG SURFACE
PRESSURE RISE CENTER DROPS INTO THE REGION 06-09Z. MAY BE A QUICK
BURST OF -SHRA/-SHSN BEHIND THE FRONT OVER THE EASTERN MOUNTAINS AND
PLAINS...WITH THE BEST CHANCE OF PRECIP NORTH OF THE ARKANSAS RIVER
AND EAST OF THE I-25 CORRIDOR. NOT LOOKING FOR MUCH IF ANY
ACCUMULATING SNOW...THOUGH VISIBILITY COULD FALL BELOW A MILE
FOR A BRIEF PERIOD UNDER THE HEAVIER SHOWERS. ANY PRECIP WILL
QUICKLY EXIT THE AREA THURSDAY MORNING...AND ONLY A FEW -SHSN WILL
BE FOUND LINGERING OVER THE CENTRAL MOUNTAINS BY AFTERNOON. STRONG
N-NW WINDS WILL CONTINUE MOST LOCATIONS THROUGH THE DAY...THOUGH
I-25 CORRIDOR WILL LIKELY SEE SOME DECREASE IN SPEEDS BY MID/LATE
AFTERNOON. MODEL RH FORECASTS KEEP ALL OF THE PLAINS ABOVE 15
PERCENT THRESHOLD FOR A FIRE WX HIGHLIGHT...BUT GIVEN ATROCIOUS
DEWPOINT FORECASTS OF LATE...EXPECT DRIEST AREAS ALONG THE NM BORDER
TO BECOME DRY ENOUGH TO WARRANT A RED FLAG WARNING...WHILE AREA
FARTHER NORTH LOOKS TOO COOL TO FORCE RH LOW ENOUGH. MAX TEMPS MOST
LOCATIONS SHOULD FALL 15-20F VERSUS WED MAXES.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 333 PM MST WED FEB 19 2014
THURSDAY NIGHT AND FRIDAY...BRISK NW FLOW ALOFT WILL KEEP SCATTERED
OR EVEN LIKELY POPS FOR THE CENTRAL MTS IN PLACE THROUGH THU
NIGHT...THEN AS THE FLOW SHIFTS TO A MORE WESTERLY DIRECTION PCPN
CHANCES ARE EXPECTED TO DROP OFF THROUGH FRI. STRONG DOWNSLOPE FLOW
IS FORECAST TO BOOST MAX TEMPS FOR THE PLAINS INTO THE MID 50S TO
AROUND 60 F. GFS AND EC MODELS PAINT A COLD FRONT DROPPING DOWN THE
EASTERN HALF OF THE STATE LATE FRI EVE. THIS WILL SET UP THE REGION
FOR A COOLER SAT.
SATURDAY AND SUNDAY...A REINFORCING PUSH OF LLVL UPSLOPE FLOW WILL
KEEP COOLER AIR IN PLACE FOR THE PLAINS...AS WELL AS BRING ISOLATED
SNOW POPS TO THE PALMER DVD AND FAR EASTERN PLAINS BY SAT AFTN AND
EVE. MEANWHILE...ISOLATED TO SCATTERED POPS CONTINUE FOR THE CENTRAL
MTS. FOR SUN...THE COOL AIR REMAINS IN PLACE FOR MAC TEMPS IN THE
30S AND 40S FOR THE CWA...BUT IT LOOKS LIKE IT MIGHT REMAIN DRY FOR
ALL AREAS WITH WESTERLY FLOW ALOFT.
MONDAY THROUGH WEDNESDAY...NW FLOW ALOFT CONTINUES WITH A CONTINUED
ISOLATED THREAT OF SNOW FOR THE CENTRAL MTS. MODELS ARE INDICATING A
DRY COLD FRONT MONDAY EVE WHICH WOULD COOL MAX TEMPS FOR TUE.
OTHERWISE...ISOLATED SNOW FOR THE HIGHER ELEVATIONS OF LAKE AND
CHAFFEE COUNTIES...WHILE DRY AND WARMER FOR THE REMAINDER OF THE
FORECAST AREA. MOORE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1019 PM MST WED FEB 19 2014
MAIN CONCERN WILL BE SN SHWRS...WHICH WILL BE THE MOST WIDESPREAD
OVR THE NEXT FEW HOURS...AND COULD RESULT IN BRIEF IFR CONDITIONS
ESPECIALLY THRU 09Z. BANDED SN SHWRS WILL MOVE TO THE S WITH THE
COLD FRONT THRU THU MORNING...SO EXPECT IMPROVING CONDITIONS AT
KCOS AFTER 09-10Z AND AT KPUB AN HOUR OR TWO LATER. ONLY SPOTTY
ISOLD SHWRS EXPECTED AT ALS...WHICH SHOULD BE VFR FOR THU.
COULD BE A FEW SHOWERS AND LOCALIZED LOW CIGS THRU ABOUT 12Z E OF
THE MTS. WINDS WILL CONTINUE TO GUST FROM THE N TO NW BEHIND THE
FRONT. THERE COULD BE A BRIEF LULL IN THE WINDS EARLY THU...BUT WINDS
SHOULD INCREASE AGAIN FROM THE NW IN THE 16Z TO 23Z TIME FRAME...AND
THERE COULD BE A FEW GUSTS IN THE 40 KT RANGE DURING THIS TIME.
WINDS WILL RELAX THU EVENING. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM MST THURSDAY FOR COZ081-082-
084.
RED FLAG WARNING FROM 11 AM TO 6 PM MST THURSDAY FOR COZ229-230-
233-237.
WINTER WEATHER ADVISORY UNTIL 8 AM MST THURSDAY FOR COZ058-060.
&&
$$
UPDATE...LW
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS ALBANY NY
1254 PM EST THU FEB 20 2014
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL NORTHWARD INTO THE WESTERN GREAT
LAKES REGION TONIGHT. ITS ASSOCIATED WARM FRONT WILL PROVIDE A
PERIOD OF WINTRY PRECIPITATION FOR MANY AREAS TONIGHT.
HOWEVER...WARMER AIR WILL EVENTUALLY LIFT NORTHWARD TO RESULT IN
MOSTLY RAIN FRIDAY ALONG WITH A SLIGHT CHANCE FOR THUNDERSTORMS. A
COLD FRONT PASSES ACROSS THE AREA FRIDAY AFTERNOON WITH A RETURN TO
COOLER WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EST...HIGH PRESSURE CONTINUES TO MOVE EAST OF THE MID
ATLANTIC AND DELMARVA REGION EARLY THIS AFTERNOON. A WARM FRONT
CONTINUES TO LIFT NORTH/NORTHEAST FROM THE OHIO VALLEY AND LOWER
MID ATLANTIC REGION. SUNSHINE...IS GIVING WAY TO PARTIAL SUNSHINE
WITH INCREASING MID AND HIGH CLOUDS FROM THE WEST. THESE CLOUDS
ARE MOVING IN QUICK WHICH WILL SLOW DOWN THE WARMING...WHICH HAS
BEEN SUBSTANTIAL TODAY WITH LOWER TO MID 40S IN MANY OF THE VALLEY
AREAS. SOME SLIGHT TWEAK WERE MADE WITH THE MAX TEMP AND TRENDS.
CLOUDS WERE ALSO RETOOLED BASED ON THE SATELLITE PICTURE. THE
LATEST HRRR 3-KM REF PRODUCT IS ALSO A TAD BIT SLOWER THIS RUN
WITH THE STRONG ISENTROPIC LIFT ON THE 285/290K SFC NOT ARRIVING
UNTIL ABOUT 23Z-01Z. THE POPS WERE RETRENDED SLIGHTLY FAVORING A
RAIN/SNOW TRANSITION ESPECIALLY FROM THE CAPITAL REGION NORTH. THE
INTENSITY OF THE PCPN...AND THE ACTUAL WET BULB COOLING WILL
DETERMINE HOW FAR SOUTH THE HEAVIER PCPN/SNOW WILL BE. THE
HEADLINES WILL REMAIN FOR NOW...AS FAR SOUTH AS THE CAPITAL
REGION.
TONIGHT...H2O VAPOR IMAGERY REVEALS A VERY POTENT SHORT WAVE
EJECTING OUT ONTO THE CENTRAL PLAINS. MEANWHILE...A SUBTROPICAL
PLUME OF MOISTURE EXTENDED FROM THE CENTRAL PACIFIC...ACROSS BAJA
CALIFORNIA AND ONTO THE SOUTHERN PLAINS AND MID WEST. PWATS WITHIN
THIS DEEPER MOISTURE WAS BETWEEN 1-3 STANDARD DEVIATIONS ABOVE
NORMAL AS NCEP MODEL SUITE AND SHORT TERM GUIDANCE /RUC13-HRRR/
SUGGEST A RAPID INCREASE IN MOISTURE TRANSPORT EVOLVING THROUGH
THE DAY TODAY. LOW LEVEL JET GREATER THAN 50KTS IS ALSO EXPECTED
TO DEVELOP TO ASSIST WITH THE MOISTURE TRANSPORT NORTHWARD INTO
OUR CWA BY LATE THIS AFTERNOON. THERMAL PROFILES FROM BUFR
PROFILES SUGGEST A RAIN/SNOW LINE SOMEWHERE ALONG OR JUST SOUTH OF
I90 PER WET BULB ZERO.
CROSS SECTIONS TONIGHT POINT TOWARD ANOTHER IMPRESSIVE 2D FGEN
ENHANCEMENTS AS PER CSTAR RESEARCH SUGGESTS BANDED STRUCTURES TO
THE PRECIP DEVELOPING OVER THE REGION. PER THE NCEP MODEL
SUITE...THIS BAND WILL MIGRATE FROM SOUTH TO NORTH THROUGH THIS
EVENING AND MAY LINGER ACROSS PORTIONS OF THE ADIRONDACKS
OVERNIGHT. IN ADDITION...INCREASING SOUTHERLY FLOW FAVORS UPSLOPE
CONDITIONS FURTHER ENHANCING THE PRECIP AMOUNTS. AS FOR
PRECIP...THERMAL PROFILES ARE TRICKY. WITHIN THE VICINITY OF I90
CORRIDOR...THE INITIAL ONSET OF PRECIP WILL LIKELY BE A RAIN/SNOW
TO SNOW THIS EARLY EVENING WITH A TRANSITION TO SLEET AND PERHAPS
A PERIOD OF FREEZING RAIN THROUGH THE LATER EVENING HOURS AS
WARMER AIR ALOFT /H850/ CLIMBS ABOVE FREEZING. DUE TO THE ENHANCE
2D FGEN AND A LAYER OF NEGATIVE EPV JUST ABOVE THIS LAYER WITH >20
UBAR/SEC OMEGA...THIS POINTS TOWARD THE POTENTIAL FOR AN MODERATE
TO HEAVY BAND OF PRECIP LIFTING NORTHWARD WITH A QUICK
ACCUMULATING SNOW THIS EVENING. THE BETTER CHANCE FOR A QUICK
ACCUMULATING SNOWFALL WILL BE NORTH OF I90 WHERE UP TO 4 INCHES
COULD FALL IN A SHORT PERIOD OF TIME. DUE TO THE COMPLEX THERMAL
PROFILES AND THE HIGH POTENTIAL FOR BANDED PRECIP STRUCTURES...WE
WILL HOIST ADVISORIES FOR THE NORTHERN 2/3RDS OF THE CWA. SOUTHERN
PORTIONS APPEAR TO REMAIN ABOVE FREEZING FOR MOST OF THE PRECIP TO
FALL AS RAIN. AS THE WARMER AIR CONTINUES ALOFT...THE PRECIP TO
THE NORTH OF I90 MIXING WITH SLEET AND FREEZING RAIN. THOSE LOWER
VALLEY LOCATIONS WITHIN THE MOUNTAINS COULD EXPERIENCE A PERIOD OF
ACCUMULATING ICE WITH CURRENT PROJECTIONS UP TO TWO TENTHS OF AN
INCH IN A FEW LOCATIONS WITH MOST AREA EXPECTED TO REMAIN BELOW
THAT VALUE.
TEMPERATURES WILL FOLLOW A NON-DIURNAL CURVE THE NEXT 24 HOURS AS
STRENGTHENING WARM ADVECTION UNFOLDS AS WARM FRONT LIFTS NORTHWARD.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
LOW LEVEL JET PER THE GEFS/SREF ENSEMBLES WILL RANGE BETWEEN 2-3
STANDARD DEVIATIONS ABOVE NORMAL ACROSS THE REGION ALONG WITH
THOSE HIGH PWATS FOR THIS TIME OF THE YEAR. AS TEMPERATURES
CONTINUE TO CLIMB ABOVE FREEZING...THIS WILL REDUCE THE WINTRY
MIXTURE TO MAINLY RAIN. THE FORECAST AREA IS EXPECTED TO BE WELL
WITHIN THE WARM SECTOR AS H850 TEMPS CLIMB TOWARD +8C. THIS WILL
INCREASE THE SNOW MELT ALONG WITH DEWPOINTS CLIMBING ABOVE
FREEZING. PATCHY FOG IS EXPECTED ALONG WITH THE INCREASE IN
RAINFALL POTENTIAL. IN FACT...FORECAST SOUNDINGS SUGGEST LIFTING
PARCELS ABOVE THE BOUNDARY LAYER YIELDS THE POSSIBILITY FOR
THUNDERSTORMS AS SHOWALTERS DROP BELOW 0C. IN COORDINATION WITH
SPC...WE WILL INTRODUCE A SLIGHT CHANCE FOR THUNDER ACROSS THE
ENTIRE REGION. RAINFALL RATES ALONG THE STRONG BAROCLINIC FRONTAL
ZONE COULD BE RATHER HIGH FOR THIS TIME OF THE YEAR. AT THIS
TIME...NO HYDRO RELATED HEADLINES BUT COULD SEE SOME URBAN AND
SMALL STREAM ISSUES AS PERHAPS ICE JAMS DUE TO BREAK UP /MORE
BELOW IN THE HYDRO SECTION/. TEMPERATURES FOR MOST OF THE AREA ARE
EXPECTED TO BE WELL INTO 40S. THE STRONG WINDS ALOFT SHOULD REMAIN
ABOVE THE BOUNDARY LAYER WITH NOT MUCH MIXING EXPECTED.
FROPA IS EXPECTED AROUND THE 21Z TIME FRAME. THE H850 TEMPS PLUNGE
FROM AROUND +8C TO AROUND -6C IN ABOUT 6HRS. THERE COULD A PERIOD
OF RAIN MIXING WITH A LITTLE SNOW IN THE WAKE OF THE FROPA BUT
ACCUMULATIONS ARE NOT EXPECTED FOR MOST OF THE REGION. WHERE SOME
LIGHT ACCUMULATIONS ARE POSSIBLE WILL BE ACROSS THE ADIRONDACKS AS
AN UPPER LEVEL IMPULSE ROTATES ACROSS THIS REGION AROUND THE
PERIPHERY OF THE DEEP UPPER LOW NEAR JAMES BAY AND SOME LAKE
ONTARIO CONTRIBUTION. TEMPERATURES WILL DIP BACK BELOW FREEZING
FRIDAY NIGHT AS SOME BLACK ICE COULD FORM ON THOSE UNTREATED
SURFACES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MUCH OF THE PERIOD WILL FEATURE THE RETURN OF BELOW NORMAL
TEMPERATURES...ALONG WITH A FEW POSSIBLE EPISODES OF SNOW SHOWERS
AND/OR LIGHT SNOW...AS MID/UPPER LEVEL HEIGHTS FALL CONSIDERABLY
ACROSS SOUTHERN AND EASTERN CANADA...INTO THE CENTRAL AND EASTERN
U.S.
HERE ARE SOME MORE SPECIFIC DETAILS...
SAT-SAT NT...IN THE WAKE OF FRIDAY/S FRONTAL SYSTEM...A BROAD
SOUTHWEST FLOW IN THE MID AND UPPER LEVELS OF THE TROPOSPHERE WILL
ALLOW FOR ONLY GRADUAL LOW LEVEL COOLING TO OCCUR. THEREFORE...WE
EXPECT TEMPS TO REMAIN ABOVE SEASONAL LEVELS ON SAT...RISING INTO
THE 40S IN MOST VALLEY AREAS...AND 30S ACROSS HIGHER ELEVATIONS. IT
IS POSSIBLE THAT SOME PORTIONS OF THE MID HUDSON VALLEY AND LOWER
ELEVATIONS IN NW CT APPROACH 50 WITH SUNSHINE AND A DOWNSLOPING
WESTERLY LOW LEVEL FLOW. IN THE AFTERNOON...A WEAK UPPER LEVEL
IMPULSE MAY BRING SOME CLOUDS...AND PERHAPS SOME LIGHT SHOWERS OF
RAIN/SNOW IN THE AFTERNOON/EVENING FOR CENTRAL AND NORTHERN AREAS.
FOR SAT NT...TEMPS WILL FALL INTO THE 20S IN MOST AREAS...WITH SOME
TEENS ACROSS THE WESTERN ADIRONDACKS...WHERE SOME SNOW SHOWERS WILL
ALSO BE POSSIBLE.
SUN-MON NT...THE TREND TOWARD COLDER TEMPS WILL CONTINUE...WITH
SUNDAY MAX TEMPS REACHING THE MID 30S TO LOWER 40S IN VALLEYS...AND
20S TO LOWER 30S ACROSS HIGHER ELEVATIONS...WHILE MONDAY MAXES ONLY
REACH THE 20S IN VALLEYS...AND TEENS ACROSS HIGHER ELEVATIONS. SOME
SNOW SHOWERS/FLURRIES WILL BE POSSIBLE ACROSS CENTRAL AND NORTHERN
AREAS LATE SUN INTO MONDAY NT. TEMPS MON NT WILL FALL INTO THE
SINGLE DIGITS IN MOST AREAS.
TUE-WED...MODEL UNCERTAINTY INCREASES WITH REGARD TO THE HANDLING OF
POTENTIAL FAST MOVING UPPER LEVEL IMPULSES DURING THIS TIME PERIOD.
THE 00Z/20 ECMWF HINTS AT ONE POSSIBLE IMPULSE AFFECTING THE REGION
TUE...ESP CENTRAL AND SOUTHERN AREAS...WITH SOME LIGHT SNOW...WHILE
THIS SIGNAL IS SOMEWHAT WEAKER IN THE 00Z/20 GFS AND GEFS. WILL
TREND TOWARD THE ECMWF SOLUTION...WITH SLIGHT CHC POPS ACROSS
CENTRAL AND SOUTHERN AREAS FOR SNOW SHOWERS...ALONG WITH SOME CHC
POPS ACROSS THE WESTERN ADIRONDACKS. BOTH THE 00Z/20 ECMWF/GFS AND
GEFS HINT AT ANOTHER IMPULSE PASSING MAINLY SOUTH OF THE REGION ON
WED...ALTHOUGH THE GEFS ARE A LITTLE FURTHER NORTH WITH POSSIBLE
MEASURABLE PRECIPITATION. WILL THEREFORE INDICATE LOW CHC POPS FOR
LIGHT SNOW ON WED. OTHERWISE...TEMPS WILL REMAIN WELL BELOW NORMAL
DURING THIS PERIOD...WITH DAYTIME MAXES MAINLY IN THE 20S FOR
VALLEYS...AND TEENS FOR HIGHER ELEVATIONS...AND OVERNIGHT MIN TEMPS
MAINLY IN THE SINGLE DIGITS TO LOWER TEENS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
HIGH AND MID LEVEL CLOUDS WILL CONTINUE TO INCREASE AND THICKEN THIS
AFTERNOON AHEAD OF A WARM FRONT APPROACHING FROM THE OHIO VALLEY AND
GREAT LAKES REGION. PRECIPITATION IS EXPECTED TO DEVELOP THIS
EVENING...BUT WITH SLIGHTLY LATER TIMING COMPARED TO PREVIOUS
FORECASTS. STILL EXPECTING A WINTRY MIX AT THE ONSET...ESPECIALLY
FROM KALB/KPSF TO KGFL. SOME SLEET MAY BRIEFLY MIX IN AT KPOU. KALB
WILL HAVE A FAIRLY QUICK CHANGE TO ALL RAIN LATER THIS EVENING...DUE
TO SOUTHERLY FLOW UP THE HUDSON VALLEY. KGFL WILL HOLD ONTO FROZEN
PRECIP THE LONGEST...INTO FRIDAY MORNING.
CONDITIONS WILL DETERIORATE TO MVFR THEN IFR THIS EVENING. SOLID
IFR/LIFR EXPECTED OVERNIGHT AND THROUGH MUCH OF FRIDAY MORNING DUE
TO RELATIVELY WARM/MOIST AIR MOVING OVER A DEEP SNOWPACK. RAIN WILL
CONTINUE THROUGH MUCH OF FRIDAY BEFORE A COLD FRONT PASSES THROUGH
DURING THE AFTERNOON.
WINDS WILL BE SOUTH-SOUTHEAST AROUND 4-8 KT...BECOMING LIGHT AND
VARIABLE TONIGHT INTO FRIDAY MORNING.
OUTLOOK...
FRIDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...FG.
FRIDAY NIGHT TO SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN. SUNDAY
NIGHT TO MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
THE SNOW DEPTHS ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN
NEW ENGLAND ARE GENERALLY FROM 1 TO 3 FEET.
MODERATING TEMPERATURES REMAIN IN THE FORECAST WHICH WILL REACH
ITS PEAK DURING FRIDAY. SNOW MELT WILL INITIALLY BE SMALL AT FIRST
WITH A GRADUAL INCREASE DURING FRIDAY.
RAINFALL TOTALS TONIGHT AND FRIDAY ARE FORECAST TO GENERALLY BE
IN THE HALF AN INCH TO ONE INCH RANGE BASED ON THE LATEST
NERFC/WPC GUIDANCE. THE HIGHER TOTALS ARE EXPECTED ACROSS THE SRN
DACKS REGION...WHERE ISOLATED AMOUNTS TO AN INCH AND A HALF ARE
POSSIBLE. THERE WILL BE A PERIOD OF WINTRY MIXTURE AT THE ONSET
AND THROUGH MOST OF TONIGHT WITH A TRANSITION TO RAIN FROM
SOUTHWEST TO NORTHEAST. WE EXPECT MUCH OF THE RAINFALL WILL SOAK
INTO THE DEEP SNOW PACK.
PER THE LATEST MMEFS...THERE IS A SMALL POTENTIAL FOR FLOODING
ACROSS THE WESTERN MOHAWK VALLEY BUT DUE TO ICE IN PLACE...FOCUS
WILL BE THE ICE JAM POTENTIAL. HOWEVER...ACCUMULATING TEMPERATURES
REMAINING ABOVE FREEZING WILL BE MINIMAL WHICH SHOULD KEEP THINGS
IN CHECK. NEVERTHELESS...IT IS NOT ZERO AS WE WILL CONTINUE TO
HIGHLIGHT WITHING THE HWO.
COLDER TEMPERATURES ARE EXPECTED FRIDAY NIGHT...AND LATER IN THE
WEEK. AN ISOLATED OR LOCALIZED ICE JAM THREAT WILL CONTINUE TO BE
MENTIONED IN THE HAZARDOUS WEATHER OUTLOOK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
THE MONTHLY SNOWFALL TOTAL FOR FEBRUARY AT THE ALBANY INTERNATIONAL
AIRPORT IS AT 27.7 INCHES THROUGH THE 19TH. IT IS THE 7TH
SNOWIEST FEBRUARY ON RECORD.
TOP 10 SNOWIEST FEBRUARYS ALBANY
1. 40.7 INCHES 1893
2. 34.5 INCHES 1962
3. 32.3 INCHES 1926
4. 31.7 INCHES 1950
5. 30.1 INCHES 2011
6. 28.6 INCHES 1993
7. 27.7 INCHES 2014
8. 27.5 INCHES 1899
9. 26.1 INCHES 1914
10. 26.0 INCHES 1958
10. 26.0 INCHES 1988
LOOKING AT THE SEASONAL SNOWFALL IT STANDS AT 64.8 INCHES. NORMAL
FOR THE ENTIRE WINTER SEASON IS 59.1 INCHES.
SO HOW DOES THIS WINTER COMPARE TO RECENT WINTERS FOR ALBANY...
2012-13: 51.4 INCHES
2011-12: 23.3 INCHES
2010-11: 87.2 INCHES
2009-10: 45.4 INCHES
2008-09: 52.6 INCHES
2007-08: 61.1 INCHES
2006-07: 45.9 INCHES
2005-06: 30.2 INCHES
2004-05: 75.9 INCHES
2003-04: 65.1 INCHES
2002-03: 105.4 INCHES
2001-02: 47.4 INCHES
2000-01: 77.1 INCHES
ALBANY EXTREMES:
SNOWIEST 1970-71 WITH 112.5 INCHES
LEAST 1912-13 WITH ONLY 13.8 INCHES
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST
FRIDAY FOR NYZ033-039>043-048>050-082>084.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM EST
THIS EVENING FOR NYZ032-038-047-051>054.
MA...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM EST
THIS EVENING FOR MAZ001-025.
VT...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST
FRIDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM/WASULA
NEAR TERM...BGM/JPV/WASULA
SHORT TERM...BGM
LONG TERM...KL
AVIATION...JPV
HYDROLOGY...KL/BGM/WASULA
CLIMATE...NWS ALY STAFF
AREA FORECAST DISCUSSION
NWS ALBANY NY
1230 PM EST THU FEB 20 2014
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL NORTHWARD INTO THE WESTERN GREAT
LAKES REGION TONIGHT. ITS ASSOCIATED WARM FRONT WILL PROVIDE A
PERIOD OF WINTRY PRECIPITATION FOR MANY AREAS TONIGHT.
HOWEVER...WARMER AIR WILL EVENTUALLY LIFT NORTHWARD TO RESULT IN
MOSTLY RAIN FRIDAY ALONG WITH A SLIGHT CHANCE FOR THUNDERSTORMS. A
COLD FRONT PASSES ACROSS THE AREA FRIDAY AFTERNOON WITH A RETURN TO
COOLER WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EST...HIGH PRESSURE CONTINUES TO MOVE EAST OF THE MID
ATLANTIC AND DELMARVA REGION EARLY THIS AFTERNOON. A WARM FRONT
CONTINUES TO LIFT NORTH/NORTHEAST FROM THE OHIO VALLEY AND LOWER
MID ATLANTIC REGION. SUNSHINE...IS GIVING WAY TO PARTIAL SUNSHINE
WITH INCREASING MID AND HIGH CLOUDS FROM THE WEST. THESE CLOUDS
ARE MOVING IN QUICK WHICH WILL SLOW DOWN THE WARMING...WHICH HAS
BEEN SUBSTANTIAL TODAY WITH LOWER TO MID 40S IN MANY OF THE VALLEY
AREAS. SOME SLIGHT TWEAK WERE MADE WITH THE MAX TEMP AND TRENDS.
CLOUDS WERE ALSO RETOOLED BASED ON THE SATELLITE PICTURE. THE
LATEST HRRR 3-KM REF PRODUCT IS ALSO A TAD BIT SLOWER THIS RUN
WITH THE STRONG ISENTROPIC LIFT ON THE 285/290K SFC NOT ARRIVING
UNTIL ABOUT 23Z-01Z. THE POPS WERE RETRENDED SLIGHTLY FAVORING A
RAIN/SNOW TRANSITION ESPECIALLY FROM THE CAPITAL REGION NORTH. THE
INTENSITY OF THE PCPN...AND THE ACTUAL WET BULB COOLING WILL
DETERMINE HOW FAR SOUTH THE HEAVIER PCPN/SNOW WILL BE. THE
HEADLINES WILL REMAIN FOR NOW...AS FAR SOUTH AS THE CAPITAL
REGION.
TONIGHT...H2O VAPOR IMAGERY REVEALS A VERY POTENT SHORT WAVE
EJECTING OUT ONTO THE CENTRAL PLAINS. MEANWHILE...A SUBTROPICAL
PLUME OF MOISTURE EXTENDED FROM THE CENTRAL PACIFIC...ACROSS BAJA
CALIFORNIA AND ONTO THE SOUTHERN PLAINS AND MID WEST. PWATS WITHIN
THIS DEEPER MOISTURE WAS BETWEEN 1-3 STANDARD DEVIATIONS ABOVE
NORMAL AS NCEP MODEL SUITE AND SHORT TERM GUIDANCE /RUC13-HRRR/
SUGGEST A RAPID INCREASE IN MOISTURE TRANSPORT EVOLVING THROUGH
THE DAY TODAY. LOW LEVEL JET GREATER THAN 50KTS IS ALSO EXPECTED
TO DEVELOP TO ASSIST WITH THE MOISTURE TRANSPORT NORTHWARD INTO
OUR CWA BY LATE THIS AFTERNOON. THERMAL PROFILES FROM BUFR
PROFILES SUGGEST A RAIN/SNOW LINE SOMEWHERE ALONG OR JUST SOUTH OF
I90 PER WET BULB ZERO.
CROSS SECTIONS TONIGHT POINT TOWARD ANOTHER IMPRESSIVE 2D FGEN
ENHANCEMENTS AS PER CSTAR RESEARCH SUGGESTS BANDED STRUCTURES TO
THE PRECIP DEVELOPING OVER THE REGION. PER THE NCEP MODEL
SUITE...THIS BAND WILL MIGRATE FROM SOUTH TO NORTH THROUGH THIS
EVENING AND MAY LINGER ACROSS PORTIONS OF THE ADIRONDACKS
OVERNIGHT. IN ADDITION...INCREASING SOUTHERLY FLOW FAVORS UPSLOPE
CONDITIONS FURTHER ENHANCING THE PRECIP AMOUNTS. AS FOR
PRECIP...THERMAL PROFILES ARE TRICKY. WITHIN THE VICINITY OF I90
CORRIDOR...THE INITIAL ONSET OF PRECIP WILL LIKELY BE A RAIN/SNOW
TO SNOW THIS EARLY EVENING WITH A TRANSITION TO SLEET AND PERHAPS
A PERIOD OF FREEZING RAIN THROUGH THE LATER EVENING HOURS AS
WARMER AIR ALOFT /H850/ CLIMBS ABOVE FREEZING. DUE TO THE ENHANCE
2D FGEN AND A LAYER OF NEGATIVE EPV JUST ABOVE THIS LAYER WITH >20
UBAR/SEC OMEGA...THIS POINTS TOWARD THE POTENTIAL FOR AN MODERATE
TO HEAVY BAND OF PRECIP LIFTING NORTHWARD WITH A QUICK
ACCUMULATING SNOW THIS EVENING. THE BETTER CHANCE FOR A QUICK
ACCUMULATING SNOWFALL WILL BE NORTH OF I90 WHERE UP TO 4 INCHES
COULD FALL IN A SHORT PERIOD OF TIME. DUE TO THE COMPLEX THERMAL
PROFILES AND THE HIGH POTENTIAL FOR BANDED PRECIP STRUCTURES...WE
WILL HOIST ADVISORIES FOR THE NORTHERN 2/3RDS OF THE CWA. SOUTHERN
PORTIONS APPEAR TO REMAIN ABOVE FREEZING FOR MOST OF THE PRECIP TO
FALL AS RAIN. AS THE WARMER AIR CONTINUES ALOFT...THE PRECIP TO
THE NORTH OF I90 MIXING WITH SLEET AND FREEZING RAIN. THOSE LOWER
VALLEY LOCATIONS WITHIN THE MOUNTAINS COULD EXPERIENCE A PERIOD OF
ACCUMULATING ICE WITH CURRENT PROJECTIONS UP TO TWO TENTHS OF AN
INCH IN A FEW LOCATIONS WITH MOST AREA EXPECTED TO REMAIN BELOW
THAT VALUE.
TEMPERATURES WILL FOLLOW A NON-DIURNAL CURVE THE NEXT 24 HOURS AS
STRENGTHENING WARM ADVECTION UNFOLDS AS WARM FRONT LIFTS NORTHWARD.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
LOW LEVEL JET PER THE GEFS/SREF ENSEMBLES WILL RANGE BETWEEN 2-3
STANDARD DEVIATIONS ABOVE NORMAL ACROSS THE REGION ALONG WITH
THOSE HIGH PWATS FOR THIS TIME OF THE YEAR. AS TEMPERATURES
CONTINUE TO CLIMB ABOVE FREEZING...THIS WILL REDUCE THE WINTRY
MIXTURE TO MAINLY RAIN. THE FORECAST AREA IS EXPECTED TO BE WELL
WITHIN THE WARM SECTOR AS H850 TEMPS CLIMB TOWARD +8C. THIS WILL
INCREASE THE SNOW MELT ALONG WITH DEWPOINTS CLIMBING ABOVE
FREEZING. PATCHY FOG IS EXPECTED ALONG WITH THE INCREASE IN
RAINFALL POTENTIAL. IN FACT...FORECAST SOUNDINGS SUGGEST LIFTING
PARCELS ABOVE THE BOUNDARY LAYER YIELDS THE POSSIBILITY FOR
THUNDERSTORMS AS SHOWALTERS DROP BELOW 0C. IN COORDINATION WITH
SPC...WE WILL INTRODUCE A SLIGHT CHANCE FOR THUNDER ACROSS THE
ENTIRE REGION. RAINFALL RATES ALONG THE STRONG BAROCLINIC FRONTAL
ZONE COULD BE RATHER HIGH FOR THIS TIME OF THE YEAR. AT THIS
TIME...NO HYDRO RELATED HEADLINES BUT COULD SEE SOME URBAN AND
SMALL STREAM ISSUES AS PERHAPS ICE JAMS DUE TO BREAK UP /MORE
BELOW IN THE HYDRO SECTION/. TEMPERATURES FOR MOST OF THE AREA ARE
EXPECTED TO BE WELL INTO 40S. THE STRONG WINDS ALOFT SHOULD REMAIN
ABOVE THE BOUNDARY LAYER WITH NOT MUCH MIXING EXPECTED.
FROPA IS EXPECTED AROUND THE 21Z TIME FRAME. THE H850 TEMPS PLUNGE
FROM AROUND +8C TO AROUND -6C IN ABOUT 6HRS. THERE COULD A PERIOD
OF RAIN MIXING WITH A LITTLE SNOW IN THE WAKE OF THE FROPA BUT
ACCUMULATIONS ARE NOT EXPECTED FOR MOST OF THE REGION. WHERE SOME
LIGHT ACCUMULATIONS ARE POSSIBLE WILL BE ACROSS THE ADIRONDACKS AS
AN UPPER LEVEL IMPULSE ROTATES ACROSS THIS REGION AROUND THE
PERIPHERY OF THE DEEP UPPER LOW NEAR JAMES BAY AND SOME LAKE
ONTARIO CONTRIBUTION. TEMPERATURES WILL DIP BACK BELOW FREEZING
FRIDAY NIGHT AS SOME BLACK ICE COULD FORM ON THOSE UNTREATED
SURFACES.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
MUCH OF THE PERIOD WILL FEATURE THE RETURN OF BELOW NORMAL
TEMPERATURES...ALONG WITH A FEW POSSIBLE EPISODES OF SNOW SHOWERS
AND/OR LIGHT SNOW...AS MID/UPPER LEVEL HEIGHTS FALL CONSIDERABLY
ACROSS SOUTHERN AND EASTERN CANADA...INTO THE CENTRAL AND EASTERN
U.S.
HERE ARE SOME MORE SPECIFIC DETAILS...
SAT-SAT NT...IN THE WAKE OF FRIDAY/S FRONTAL SYSTEM...A BROAD
SOUTHWEST FLOW IN THE MID AND UPPER LEVELS OF THE TROPOSPHERE WILL
ALLOW FOR ONLY GRADUAL LOW LEVEL COOLING TO OCCUR. THEREFORE...WE
EXPECT TEMPS TO REMAIN ABOVE SEASONAL LEVELS ON SAT...RISING INTO
THE 40S IN MOST VALLEY AREAS...AND 30S ACROSS HIGHER ELEVATIONS. IT
IS POSSIBLE THAT SOME PORTIONS OF THE MID HUDSON VALLEY AND LOWER
ELEVATIONS IN NW CT APPROACH 50 WITH SUNSHINE AND A DOWNSLOPING
WESTERLY LOW LEVEL FLOW. IN THE AFTERNOON...A WEAK UPPER LEVEL
IMPULSE MAY BRING SOME CLOUDS...AND PERHAPS SOME LIGHT SHOWERS OF
RAIN/SNOW IN THE AFTERNOON/EVENING FOR CENTRAL AND NORTHERN AREAS.
FOR SAT NT...TEMPS WILL FALL INTO THE 20S IN MOST AREAS...WITH SOME
TEENS ACROSS THE WESTERN ADIRONDACKS...WHERE SOME SNOW SHOWERS WILL
ALSO BE POSSIBLE.
SUN-MON NT...THE TREND TOWARD COLDER TEMPS WILL CONTINUE...WITH
SUNDAY MAX TEMPS REACHING THE MID 30S TO LOWER 40S IN VALLEYS...AND
20S TO LOWER 30S ACROSS HIGHER ELEVATIONS...WHILE MONDAY MAXES ONLY
REACH THE 20S IN VALLEYS...AND TEENS ACROSS HIGHER ELEVATIONS. SOME
SNOW SHOWERS/FLURRIES WILL BE POSSIBLE ACROSS CENTRAL AND NORTHERN
AREAS LATE SUN INTO MONDAY NT. TEMPS MON NT WILL FALL INTO THE
SINGLE DIGITS IN MOST AREAS.
TUE-WED...MODEL UNCERTAINTY INCREASES WITH REGARD TO THE HANDLING OF
POTENTIAL FAST MOVING UPPER LEVEL IMPULSES DURING THIS TIME PERIOD.
THE 00Z/20 ECMWF HINTS AT ONE POSSIBLE IMPULSE AFFECTING THE REGION
TUE...ESP CENTRAL AND SOUTHERN AREAS...WITH SOME LIGHT SNOW...WHILE
THIS SIGNAL IS SOMEWHAT WEAKER IN THE 00Z/20 GFS AND GEFS. WILL
TREND TOWARD THE ECMWF SOLUTION...WITH SLIGHT CHC POPS ACROSS
CENTRAL AND SOUTHERN AREAS FOR SNOW SHOWERS...ALONG WITH SOME CHC
POPS ACROSS THE WESTERN ADIRONDACKS. BOTH THE 00Z/20 ECMWF/GFS AND
GEFS HINT AT ANOTHER IMPULSE PASSING MAINLY SOUTH OF THE REGION ON
WED...ALTHOUGH THE GEFS ARE A LITTLE FURTHER NORTH WITH POSSIBLE
MEASURABLE PRECIPITATION. WILL THEREFORE INDICATE LOW CHC POPS FOR
LIGHT SNOW ON WED. OTHERWISE...TEMPS WILL REMAIN WELL BELOW NORMAL
DURING THIS PERIOD...WITH DAYTIME MAXES MAINLY IN THE 20S FOR
VALLEYS...AND TEENS FOR HIGHER ELEVATIONS...AND OVERNIGHT MIN TEMPS
MAINLY IN THE SINGLE DIGITS TO LOWER TEENS.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
AFTER ANY FOG/LOW CLOUDS LIFT BETWEEN 12Z-14Z/THU...VFR CONDITIONS
ARE EXPECTED THROUGH AT LEAST 22Z/THU. THEREAFTER...A STRONG WARM
FRONT WILL APPROACH FROM THE SOUTHWEST. A BAND OF MODERATE TO
LOCALLY HEAVY PRECIPITATION IS EXPECTED TO DEVELOP AHEAD OF THIS
FRONT...IMPACTING KGFL THE LONGEST...AND SOMEWHAT SHORTER AT
KALB/KPSF...AND LEAST AT KPOU. P-TYPE INITIALLY SHOULD BE MAINLY
SNOW AT KGFL...AND A MIX OF SNOW/SLEET AND SOME RAIN AT KALB AND
KPSF. AS MILDER AIR ALOFT MOVES IN...SNOW SHOULD CHANGE TO A MIX OF
FREEZING RAIN AND SLEET AFTER ROUGHLY 03Z/FRI AT KGFL. AT KALB AND
KPSF...AFTER A SNOW/SLEET/RAIN MIX...P-TYPE SHOULD BECOME MAINLY
RAIN WITH PERHAPS SOME OCCASIONAL SLEET AFTER 03Z/FRI. CONDITIONS
WILL GENERALLY BE IFR IN AREAS WHERE SNOW AND SLEET INITIALLY
OCCUR...AND MVFR WITHIN ANY RAIN. HOWEVER...LATER TONIGHT...CIGS
AND VSBYS WILL LIKELY DIP INTO THE IFR/LIFR RANGE IN ALL AREAS.
WEST TO NORTHWEST WINDS AT 5-10 KT WILL BECOME LIGHT/VARIABLE AS A
HIGH PRESSURE RIDGE SLIDES ACROSS THE TAF SITES. AS THE RIDGE SHIFTS
EAST OF THE TAF SITES...WINDS WILL BECOME SOUTHEAST TO SOUTH AT 5-10
KT LATER THIS AFTERNOON INTO TONIGHT...ALTHOUGH MAY BACK INTO THE
NORTHEAST AT KGFL AFTER SUNSET. WINDS THU NT SHOULD BE MAINLY FROM
THE E TO NE...AT LESS THAN 5 KT...EXCEPT SOUTH TO SOUTHEAST AT KALB
AT 5-10 KT.
OUTLOOK...
THURSDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA...FG.
FRIDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...FG.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
THE SNOW DEPTHS ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN
NEW ENGLAND ARE GENERALLY FROM 1 TO 3 FEET.
MODERATING TEMPERATURES REMAIN IN THE FORECAST WHICH WILL REACH
ITS PEAK DURING FRIDAY. SNOW MELT WILL INITIALLY BE SMALL AT FIRST
WITH A GRADUAL INCREASE DURING FRIDAY.
RAINFALL TOTALS TONIGHT AND FRIDAY ARE FORECAST TO GENERALLY BE
IN THE HALF AN INCH TO ONE INCH RANGE BASED ON THE LATEST
NERFC/WPC GUIDANCE. THE HIGHER TOTALS ARE EXPECTED ACROSS THE SRN
DACKS REGION...WHERE ISOLATED AMOUNTS TO AN INCH AND A HALF ARE
POSSIBLE. THERE WILL BE A PERIOD OF WINTRY MIXTURE AT THE ONSET
AND THROUGH MOST OF TONIGHT WITH A TRANSITION TO RAIN FROM
SOUTHWEST TO NORTHEAST. WE EXPECT MUCH OF THE RAINFALL WILL SOAK
INTO THE DEEP SNOW PACK.
PER THE LATEST MMEFS...THERE IS A SMALL POTENTIAL FOR FLOODING
ACROSS THE WESTERN MOHAWK VALLEY BUT DUE TO ICE IN PLACE...FOCUS
WILL BE THE ICE JAM POTENTIAL. HOWEVER...ACCUMULATING TEMPERATURES
REMAINING ABOVE FREEZING WILL BE MINIMAL WHICH SHOULD KEEP THINGS
IN CHECK. NEVERTHELESS...IT IS NOT ZERO AS WE WILL CONTINUE TO
HIGHLIGHT WITHING THE HWO.
COLDER TEMPERATURES ARE EXPECTED FRIDAY NIGHT...AND LATER IN THE
WEEK. AN ISOLATED OR LOCALIZED ICE JAM THREAT WILL CONTINUE TO BE
MENTIONED IN THE HAZARDOUS WEATHER OUTLOOK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
THE MONTHLY SNOWFALL TOTAL FOR FEBRUARY AT THE ALBANY INTERNATIONAL
AIRPORT IS AT 27.7 INCHES THROUGH THE 19TH. IT IS THE 7TH
SNOWIEST FEBRUARY ON RECORD.
TOP 10 SNOWIEST FEBRUARYS ALBANY
1. 40.7 INCHES 1893
2. 34.5 INCHES 1962
3. 32.3 INCHES 1926
4. 31.7 INCHES 1950
5. 30.1 INCHES 2011
6. 28.6 INCHES 1993
7. 27.7 INCHES 2014
8. 27.5 INCHES 1899
9. 26.1 INCHES 1914
10. 26.0 INCHES 1958
10. 26.0 INCHES 1988
LOOKING AT THE SEASONAL SNOWFALL IT STANDS AT 64.8 INCHES. NORMAL
FOR THE ENTIRE WINTER SEASON IS 59.1 INCHES.
SO HOW DOES THIS WINTER COMPARE TO RECENT WINTERS FOR ALBANY...
2012-13: 51.4 INCHES
2011-12: 23.3 INCHES
2010-11: 87.2 INCHES
2009-10: 45.4 INCHES
2008-09: 52.6 INCHES
2007-08: 61.1 INCHES
2006-07: 45.9 INCHES
2005-06: 30.2 INCHES
2004-05: 75.9 INCHES
2003-04: 65.1 INCHES
2002-03: 105.4 INCHES
2001-02: 47.4 INCHES
2000-01: 77.1 INCHES
ALBANY EXTREMES:
SNOWIEST 1970-71 WITH 112.5 INCHES
LEAST 1912-13 WITH ONLY 13.8 INCHES
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST
FRIDAY FOR NYZ033-039>043-048>050-082>084.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM EST
THIS EVENING FOR NYZ032-038-047-051>054.
MA...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM EST
THIS EVENING FOR MAZ001-025.
VT...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST
FRIDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM/WASULA
NEAR TERM...BGM/JPV/WASULA
SHORT TERM...BGM
LONG TERM...KL
AVIATION...KL
HYDROLOGY...KL/BGM/WASULA
CLIMATE...
AREA FORECAST DISCUSSION
NWS ALBANY NY
944 AM EST THU FEB 20 2014
.SYNOPSIS...
A POWERFUL STORM WILL DEVELOP OVER THE CENTER OF THE NATION AND
TRACK NORTHWARD ACROSS THE GREAT LAKES REGION TONIGHT. ITS
ASSOCIATED WARM FRONT WILL PROVIDE A PERIOD OF WINTRY
PRECIPITATION FOR MANY AREAS TONIGHT. HOWEVER..WARMER AIR WILL
EVENTUALLY LIFT NORTHWARD TO RESULT IN MOSTLY RAIN FRIDAY ALONG
WITH A CHANCE FOR A THUNDERSTORM. A STRONG COLD FRONT PASSES
ACROSS THE AREA FRIDAY AFTERNOON WITH A RETURN TO COOLER WEATHER
FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 944 AM EST...JUST SOME MINOR CHANGES FOR THE REST OF TODAY.
TEMPERATURES ARE RISING RATHER QUICKLY THIS MORNING...EVEN FOR
AREAS THAT WERE COLDER EARLIER THIS MORNING DUE TO PLENTY OF
SUNSHINE AND A WARMING SOUTHWEST FLOW ALOFT. SO CURRENT
TEMPERATURE FORECAST LOOKS TO BE ON TRACK WITH ALL AREAS EXPECTED
TO REACH WELL ABOVE FREEZING THIS AFTERNOON. OTHERWISE...HIGH AND
MID LEVEL CLOUDS WILL GRADUALLY INCREASE THROUGH THE REST OF THE
DAY AHEAD OF A WARM FRONT APPROACHING FROM THE OHIO VALLEY AND
GREAT LAKES REGION.
UPSTREAM ELEVATED CONVECTIVE ACTIVITY CONTINUES TO BE RATHER
IMPRESSIVE WITH A SMALL-SCALE MCS APPROACHING MOVING THROUGH
IL/IN/OH/MI AREA. LATEST HRRR REFLECTIVITY FORECASTS SUGGEST
REMNANTS OF THIS ACTIVITY FORCED BY INCREASING ISENTROPIC LIFT
AND ENHANCED 2D FGEN...WILL MOVE INTO OUR AREA TOWARD THE 22-00Z
TIME FRAME. THERMAL PROFILES STILL LOOK RATHER CHILLY FOR THE
NORTHERN 2/3RDS WITH SNOW MIXING WITH SLEET AND FREEZING RAIN AS
NO CHANGES TO THE CURRENT HEADLINES.
H2O VAPOR IMAGERY REVEALS A VERY POTENT SHORT WAVE EJECTING OUT
ONTO THE CENTRAL PLAINS. MEANWHILE...A SUBTROPICAL PLUME OF
MOISTURE EXTENDED FROM THE CENTRAL PACIFIC...ACROSS BAJA
CALIFORNIA AND ONTO THE SOUTHERN PLAINS AND MID WEST. PWATS WITHIN
THIS DEEPER MOISTURE WAS BETWEEN 1-3 STANDARD DEVIATIONS ABOVE
NORMAL AS NCEP MODEL SUITE AND SHORT TERM GUIDANCE /RUC13-HRRR/
SUGGEST A RAPID INCREASE IN MOISTURE TRANSPORT EVOLVING THROUGH
THE DAY TODAY. LOW LEVEL JET GREATER THAN 50KTS IS ALSO EXPECTED
TO DEVELOP TO ASSIST WITH THE MOISTURE TRANSPORT NORTHWARD INTO
OUR CWA BY LATE THIS AFTERNOON. THERMAL PROFILES FROM BUFR
PROFILES SUGGEST A RAIN/SNOW LINE SOMEWHERE ALONG OR JUST SOUTH OF
I90 PER WET BULB ZERO.
CROSS SECTIONS TONIGHT POINT TOWARD ANOTHER IMPRESSIVE 2D FGEN
ENHANCEMENTS AS PER CSTAR RESEARCH SUGGESTS BANDED STRUCTURES TO
THE PRECIP DEVELOPING OVER THE REGION. PER THE NCEP MODEL
SUITE...THIS BAND WILL MIGRATE FROM SOUTH TO NORTH THROUGH THIS
EVENING AND MAY LINGER ACROSS PORTIONS OF THE ADIRONDACKS
OVERNIGHT. IN ADDITION...INCREASING SOUTHERLY FLOW FAVORS UPSLOPE
CONDITIONS FURTHER ENHANCING THE PRECIP AMOUNTS. AS FOR
PRECIP...THERMAL PROFILES ARE TRICKY. WITHIN THE VICINITY OF I90
CORRIDOR...THE INITIAL ONSET OF PRECIP WILL LIKELY BE A RAIN/SNOW
TO SNOW THIS EARLY EVENING WITH A TRANSITION TO SLEET AND PERHAPS
A PERIOD OF FREEZING RAIN THROUGH THE LATER EVENING HOURS AS
WARMER AIR ALOFT /H850/ CLIMBS ABOVE FREEZING. DUE TO THE ENHANCE
2D FGEN AND A LAYER OF NEGATIVE EPV JUST ABOVE THIS LAYER WITH >20
UBAR/SEC OMEGA...THIS POINTS TOWARD THE POTENTIAL FOR AN MODERATE
TO HEAVY BAND OF PRECIP LIFTING NORTHWARD WITH A QUICK
ACCUMULATING SNOW THIS EVENING. THE BETTER CHANCE FOR A QUICK
ACCUMULATING SNOWFALL WILL BE NORTH OF I90 WHERE UP TO 4 INCHES
COULD FALL IN A SHORT PERIOD OF TIME. DUE TO THE COMPLEX THERMAL
PROFILES AND THE HIGH POTENTIAL FOR BANDED PRECIP STRUCTURES...WE
WILL HOIST ADVISORIES FOR THE NORTHERN 2/3RDS OF THE CWA. SOUTHERN
PORTIONS APPEAR TO REMAIN ABOVE FREEZING FOR MOST OF THE PRECIP TO
FALL AS RAIN. AS THE WARMER AIR CONTINUES ALOFT...THE PRECIP TO
THE NORTH OF I90 MIXING WITH SLEET AND FREEZING RAIN. THOSE LOWER
VALLEY LOCATIONS WITHIN THE MOUNTAINS COULD EXPERIENCE A PERIOD OF
ACCUMULATING ICE WITH CURRENT PROJECTIONS UP TO TWO TENTHS OF AN
INCH IN A FEW LOCATIONS WITH MOST AREA EXPECTED TO REMAIN BELOW
THAT VALUE.
TEMPERATURES WILL FOLLOW A NON-DIURNAL CURVE THE NEXT 24 HOURS AS
STRENGTHENING WARM ADVECTION UNFOLDS AS WARM FRONT LIFTS NORTHWARD.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
LOW LEVEL JET PER THE GEFS/SREF ENSEMBLES WILL RANGE BETWEEN 2-3
STANDARD DEVIATIONS ABOVE NORMAL ACROSS THE REGION ALONG WITH
THOSE HIGH PWATS FOR THIS TIME OF THE YEAR. AS TEMPERATURES
CONTINUE TO CLIMB ABOVE FREEZING...THIS WILL REDUCE THE WINTRY
MIXTURE TO MAINLY RAIN. THE FORECAST AREA IS EXPECTED TO BE WELL
WITHIN THE WARM SECTOR AS H850 TEMPS CLIMB TOWARD +8C. THIS WILL
INCREASE THE SNOW MELT ALONG WITH DEWPOINTS CLIMBING ABOVE
FREEZING. PATCHY FOG IS EXPECTED ALONG WITH THE INCREASE IN
RAINFALL POTENTIAL. IN FACT...FORECAST SOUNDINGS SUGGEST LIFTING
PARCELS ABOVE THE BOUNDARY LAYER YIELDS THE POSSIBILITY FOR
THUNDERSTORMS AS SHOWALTERS DROP BELOW 0C. IN COORDINATION WITH
SPC...WE WILL INTRODUCE A SLIGHT CHANCE FOR THUNDER ACROSS THE
ENTIRE REGION. RAINFALL RATES ALONG THE STRONG BAROCLINIC FRONTAL
ZONE COULD BE RATHER HIGH FOR THIS TIME OF THE YEAR. AT THIS
TIME...NO HYDRO RELATED HEADLINES BUT COULD SEE SOME URBAN AND
SMALL STREAM ISSUES AS PERHAPS ICE JAMS DUE TO BREAK UP /MORE
BELOW IN THE HYDRO SECTION/. TEMPERATURES FOR MOST OF THE AREA ARE
EXPECTED TO BE WELL INTO 40S. THE STRONG WINDS ALOFT SHOULD REMAIN
ABOVE THE BOUNDARY LAYER WITH NOT MUCH MIXING EXPECTED.
FROPA IS EXPECTED AROUND THE 21Z TIME FRAME. THE H850 TEMPS PLUNGE
FROM AROUND +8C TO AROUND -6C IN ABOUT 6HRS. THERE COULD A PERIOD
OF RAIN MIXING WITH A LITTLE SNOW IN THE WAKE OF THE FROPA BUT
ACCUMULATIONS ARE NOT EXPECTED FOR MOST OF THE REGION. WHERE SOME
LIGHT ACCUMULATIONS ARE POSSIBLE WILL BE ACROSS THE ADIRONDACKS AS
AN UPPER LEVEL IMPULSE ROTATES ACROSS THIS REGION AROUND THE
PERIPHERY OF THE DEEP UPPER LOW NEAR JAMES BAY AND SOME LAKE
ONTARIO CONTRIBUTION. TEMPERATURES WILL DIP BACK BELOW FREEZING
FRIDAY NIGHT AS SOME BLACK ICE COULD FORM ON THOSE UNTREATED
SURFACES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MUCH OF THE PERIOD WILL FEATURE THE RETURN OF BELOW NORMAL
TEMPERATURES...ALONG WITH A FEW POSSIBLE EPISODES OF SNOW SHOWERS
AND/OR LIGHT SNOW...AS MID/UPPER LEVEL HEIGHTS FALL CONSIDERABLY
ACROSS SOUTHERN AND EASTERN CANADA...INTO THE CENTRAL AND EASTERN
U.S.
HERE ARE SOME MORE SPECIFIC DETAILS...
SAT-SAT NT...IN THE WAKE OF FRIDAY/S FRONTAL SYSTEM...A BROAD
SOUTHWEST FLOW IN THE MID AND UPPER LEVELS OF THE TROPOSPHERE WILL
ALLOW FOR ONLY GRADUAL LOW LEVEL COOLING TO OCCUR. THEREFORE...WE
EXPECT TEMPS TO REMAIN ABOVE SEASONAL LEVELS ON SAT...RISING INTO
THE 40S IN MOST VALLEY AREAS...AND 30S ACROSS HIGHER ELEVATIONS. IT
IS POSSIBLE THAT SOME PORTIONS OF THE MID HUDSON VALLEY AND LOWER
ELEVATIONS IN NW CT APPROACH 50 WITH SUNSHINE AND A DOWNSLOPING
WESTERLY LOW LEVEL FLOW. IN THE AFTERNOON...A WEAK UPPER LEVEL
IMPULSE MAY BRING SOME CLOUDS...AND PERHAPS SOME LIGHT SHOWERS OF
RAIN/SNOW IN THE AFTERNOON/EVENING FOR CENTRAL AND NORTHERN AREAS.
FOR SAT NT...TEMPS WILL FALL INTO THE 20S IN MOST AREAS...WITH SOME
TEENS ACROSS THE WESTERN ADIRONDACKS...WHERE SOME SNOW SHOWERS WILL
ALSO BE POSSIBLE.
SUN-MON NT...THE TREND TOWARD COLDER TEMPS WILL CONTINUE...WITH
SUNDAY MAX TEMPS REACHING THE MID 30S TO LOWER 40S IN VALLEYS...AND
20S TO LOWER 30S ACROSS HIGHER ELEVATIONS...WHILE MONDAY MAXES ONLY
REACH THE 20S IN VALLEYS...AND TEENS ACROSS HIGHER ELEVATIONS. SOME
SNOW SHOWERS/FLURRIES WILL BE POSSIBLE ACROSS CENTRAL AND NORTHERN
AREAS LATE SUN INTO MONDAY NT. TEMPS MON NT WILL FALL INTO THE
SINGLE DIGITS IN MOST AREAS.
TUE-WED...MODEL UNCERTAINTY INCREASES WITH REGARD TO THE HANDLING OF
POTENTIAL FAST MOVING UPPER LEVEL IMPULSES DURING THIS TIME PERIOD.
THE 00Z/20 ECMWF HINTS AT ONE POSSIBLE IMPULSE AFFECTING THE REGION
TUE...ESP CENTRAL AND SOUTHERN AREAS...WITH SOME LIGHT SNOW...WHILE
THIS SIGNAL IS SOMEWHAT WEAKER IN THE 00Z/20 GFS AND GEFS. WILL
TREND TOWARD THE ECMWF SOLUTION...WITH SLIGHT CHC POPS ACROSS
CENTRAL AND SOUTHERN AREAS FOR SNOW SHOWERS...ALONG WITH SOME CHC
POPS ACROSS THE WESTERN ADIRONDACKS. BOTH THE 00Z/20 ECMWF/GFS AND
GEFS HINT AT ANOTHER IMPULSE PASSING MAINLY SOUTH OF THE REGION ON
WED...ALTHOUGH THE GEFS ARE A LITTLE FURTHER NORTH WITH POSSIBLE
MEASURABLE PRECIPITATION. WILL THEREFORE INDICATE LOW CHC POPS FOR
LIGHT SNOW ON WED. OTHERWISE...TEMPS WILL REMAIN WELL BELOW NORMAL
DURING THIS PERIOD...WITH DAYTIME MAXES MAINLY IN THE 20S FOR
VALLEYS...AND TEENS FOR HIGHER ELEVATIONS...AND OVERNIGHT MIN TEMPS
MAINLY IN THE SINGLE DIGITS TO LOWER TEENS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
AFTER ANY FOG/LOW CLOUDS LIFT BETWEEN 12Z-14Z/THU...VFR CONDITIONS
ARE EXPECTED THROUGH AT LEAST 22Z/THU. THEREAFTER...A STRONG WARM
FRONT WILL APPROACH FROM THE SOUTHWEST. A BAND OF MODERATE TO
LOCALLY HEAVY PRECIPITATION IS EXPECTED TO DEVELOP AHEAD OF THIS
FRONT...IMPACTING KGFL THE LONGEST...AND SOMEWHAT SHORTER AT
KALB/KPSF...AND LEAST AT KPOU. P-TYPE INITIALLY SHOULD BE MAINLY
SNOW AT KGFL...AND A MIX OF SNOW/SLEET AND SOME RAIN AT KALB AND
KPSF. AS MILDER AIR ALOFT MOVES IN...SNOW SHOULD CHANGE TO A MIX OF
FREEZING RAIN AND SLEET AFTER ROUGHLY 03Z/FRI AT KGFL. AT KALB AND
KPSF...AFTER A SNOW/SLEET/RAIN MIX...P-TYPE SHOULD BECOME MAINLY
RAIN WITH PERHAPS SOME OCCASIONAL SLEET AFTER 03Z/FRI. CONDITIONS
WILL GENERALLY BE IFR IN AREAS WHERE SNOW AND SLEET INITIALLY
OCCUR...AND MVFR WITHIN ANY RAIN. HOWEVER...LATER TONIGHT...CIGS
AND VSBYS WILL LIKELY DIP INTO THE IFR/LIFR RANGE IN ALL AREAS.
WEST TO NORTHWEST WINDS AT 5-10 KT WILL BECOME LIGHT/VARIABLE AS A
HIGH PRESSURE RIDGE SLIDES ACROSS THE TAF SITES. AS THE RIDGE SHIFTS
EAST OF THE TAF SITES...WINDS WILL BECOME SOUTHEAST TO SOUTH AT 5-10
KT LATER THIS AFTERNOON INTO TONIGHT...ALTHOUGH MAY BACK INTO THE
NORTHEAST AT KGFL AFTER SUNSET. WINDS THU NT SHOULD BE MAINLY FROM
THE E TO NE...AT LESS THAN 5 KT...EXCEPT SOUTH TO SOUTHEAST AT KALB
AT 5-10 KT.
OUTLOOK...
THURSDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA...FG.
FRIDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...FG.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
THE SNOW DEPTHS ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN
NEW ENGLAND ARE GENERALLY FROM 1 TO 3 FEET.
MODERATING TEMPERATURES REMAIN IN THE FORECAST WHICH WILL REACH
ITS PEAK DURING FRIDAY. SNOW MELT WILL INITIALLY BE SMALL AT FIRST
WITH A GRADUAL INCREASE DURING FRIDAY.
RAINFALL TOTALS TONIGHT AND FRIDAY ARE FORECAST TO GENERALLY BE
IN THE HALF AN INCH TO ONE INCH RANGE BASED ON THE LATEST
NERFC/WPC GUIDANCE. THE HIGHER TOTALS ARE EXPECTED ACROSS THE SRN
DACKS REGION...WHERE ISOLATED AMOUNTS TO AN INCH AND A HALF ARE
POSSIBLE. THERE WILL BE A PERIOD OF WINTRY MIXTURE AT THE ONSET
AND THROUGH MOST OF TONIGHT WITH A TRANSITION TO RAIN FROM
SOUTHWEST TO NORTHEAST. WE EXPECT MUCH OF THE RAINFALL WILL SOAK
INTO THE DEEP SNOW PACK.
PER THE LATEST MMEFS...THERE IS A SMALL POTENTIAL FOR FLOODING
ACROSS THE WESTERN MOHAWK VALLEY BUT DUE TO ICE IN PLACE...FOCUS
WILL BE THE ICE JAM POTENTIAL. HOWEVER...ACCUMULATING TEMPERATURES
REMAINING ABOVE FREEZING WILL BE MINIMAL WHICH SHOULD KEEP THINGS
IN CHECK. NEVERTHELESS...IT IS NOT ZERO AS WE WILL CONTINUE TO
HIGHLIGHT WITHING THE HWO.
COLDER TEMPERATURES ARE EXPECTED FRIDAY NIGHT...AND LATER IN THE
WEEK. AN ISOLATED OR LOCALIZED ICE JAM THREAT WILL CONTINUE TO BE
MENTIONED IN THE HAZARDOUS WEATHER OUTLOOK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
THE MONTHLY SNOWFALL TOTAL FOR FEBRUARY AT THE ALBANY INTERNATIONAL
AIRPORT IS AT 27.7 INCHES THROUGH THE 19TH. IT IS THE 7TH
SNOWIEST FEBRUARY ON RECORD.
TOP 10 SNOWIEST FEBRUARYS ALBANY
1. 40.7 INCHES 1893
2. 34.5 INCHES 1962
3. 32.3 INCHES 1926
4. 31.7 INCHES 1950
5. 30.1 INCHES 2011
6. 28.6 INCHES 1993
7. 27.7 INCHES 2014
8. 27.5 INCHES 1899
9. 26.1 INCHES 1914
10. 26.0 INCHES 1958
10. 26.0 INCHES 1988
LOOKING AT THE SEASONAL SNOWFALL IT STANDS AT 64.8 INCHES. NORMAL
FOR THE ENTIRE WINTER SEASON IS 59.1 INCHES.
SO HOW DOES THIS WINTER COMPARE TO RECENT WINTERS FOR ALBANY...
2012-13: 51.4 INCHES
2011-12: 23.3 INCHES
2010-11: 87.2 INCHES
2009-10: 45.4 INCHES
2008-09: 52.6 INCHES
2007-08: 61.1 INCHES
2006-07: 45.9 INCHES
2005-06: 30.2 INCHES
2004-05: 75.9 INCHES
2003-04: 65.1 INCHES
2002-03: 105.4 INCHES
2001-02: 47.4 INCHES
2000-01: 77.1 INCHES
ALBANY EXTREMES:
SNOWIEST 1970-71 WITH 112.5 INCHES
LEAST 1912-13 WITH ONLY 13.8 INCHES
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST
FRIDAY FOR NYZ033-039>043-048>050-082>084.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM EST
THIS EVENING FOR NYZ032-038-047-051>054.
MA...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 PM EST
THIS EVENING FOR MAZ001-025.
VT...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST
FRIDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM/JPV
SHORT TERM...BGM
LONG TERM...KL
AVIATION...KL
HYDROLOGY...KL/BGM/WASULA
CLIMATE...NWS STAFF
LONG TERM FORECAST DISCUSSION...
/ISSUED 415 AM EST THU FEB 20 2014/
BEHIND FRIDAY`S COLD FRONT... ECMWF AND GFS SHOW A COOL DOME OF
HIGH PRESSURE BUILDING OVER THE FORECAST AREA FRIDAY NIGHT... AND
SHOULD DOMINATE THROUGH SATURDAY. THE RIDGE DOES SLIP EAST AND
ESTABLISH A LIGHT/WARM SOUTHERLY WIND FLOW BY SATURDAY AFTERNOON.
THIS WILL ALLOW A NICE WARM-UP INTO THE 60S ON SATURDAY.
BOTH MODELS SHOW A WEAK UPPER DISTURBANCE IN THE NEARLY ZONAL FLOW
ALOFT TRAVERSING THE AREAS AND INTERACTING WITH AN OLD FRONTAL
BOUNDARY ACROSS SOUTH GEORGIA. THIS SPREADS SOME ISOLATED TO LOW
SCATTERED SHOWERS INTO THE FORECAST AREA ON SUNDAY...WITH THE GREATER
RAIN CHANCES EXPECTED ACROSS PARTS OF CENTRAL GEORGIA ON SUNDAY.
STILL GOOD AGREEMENT ON A REINFORCING COLD FRONT PUSHING ACROSS
THE AREA SUNDAY NIGHT... WITH A DRY FORECAST ON TAP FOR MONDAY.
BOTH MODELS SHOW AN ACTIVE NEARLY ZONAL FLOW ALOFT INTERACTING
WITH A WEAK FRONTAL BOUNDARY MEANDERING ACROSS THE AREA ON TUESDAY
AND WEDNESDAY. STILL SOME UNCERTAINTY ON JUST WHERE BEST RAIN
CHANCES WILL SET UP... SO WILL JUST SHOW A SLIGHT CHANCE OF
SHOWERS ALL ZONES FOR NOW. LACK OF INSTABILITY AND WIND SHEAR WILL
WARRANT JUST WORDING FOR SHOWERS WITH NO THUNDERSTORMS EXPECTED AT
THIS TIME.
39
&&
.AVIATION...
06Z UPDATE...
LINE OF SHOWERS AND THUNDERSTORMS EXPECTED TO MOVE THROUGH THE
AREA OVERNIGHT...WITH DEGRADING CIGS AND VSBYS ACCOMPANYING THE
TSRA. HAVE TIMED THE SQUALL LINE THROUGH THE ATL AREA BY 10Z...AND
THE MCN AND AHN AREAS BY AROUND 12Z. S-SW GUSTY WINDS /15G25KT OR
SO/ WILL BECOME NW AT 13-15KT GUSTS TO 22-25KT BEHIND THE LINE.
EXPECT HIGH IFR OR LOW MVFR CIGS WITH THE POST-TSRA LIGHT
RAIN...WITH SLOW IMPROVEMENT THROUGH FRIDAY MORNING...AND VFR BY AFTERNOON.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON ALL ELEMENTS.
31
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 62 34 67 41 / 100 5 10 10
ATLANTA 58 38 64 44 / 80 5 10 10
BLAIRSVILLE 54 30 62 35 / 70 5 10 10
CARTERSVILLE 59 31 66 38 / 60 5 10 10
COLUMBUS 60 38 67 47 / 100 5 10 10
GAINESVILLE 60 36 66 40 / 100 5 10 10
MACON 63 33 68 44 / 90 5 10 10
ROME 60 29 65 37 / 40 5 10 10
PEACHTREE CITY 60 29 67 40 / 90 5 10 10
VIDALIA 66 44 68 49 / 100 10 10 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
TORNADO WATCH UNTIL 5 AM EST EARLY THIS MORNING FOR THE
FOLLOWING ZONES: BARTOW...CATOOSA...CHATTOOGA...CHEROKEE...
DADE...DAWSON...FANNIN...FLOYD...FORSYTH...GILMER...GORDON...
HALL...LUMPKIN...MURRAY...PICKENS...TOWNS...UNION...WALKER...
WHITE...WHITFIELD.
&&
$$
SHORT TERM...31
LONG TERM....39
AVIATION...31
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
212 PM EST THU FEB 20 2014
.SYNOPSIS...
WARM TEMPERATURES CONTINUE ONCE AGAIN TODAY AHEAD OF AN
APPROACHING COLD FRONT. THIS STRONG COLD FRONT WILL CROSS THE
AREA FRIDAY BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS. HIGH
PRESSURE AND DRIER AIR WILL BUILD INTO THE REGION FRIDAY EVENING.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE HIGH PRESSURE WILL REMAIN OVER THE WESTERN ATLANTIC.
WE ARE EXPECTING NEAR RECORD HIGH TEMPERATURES UNDER SUNNY SKIES
THIS AFTERNOON. TEMPERATURES SHOULD PEAK IN THE MID 70S TO LOWER
80S.
LOW PRESSURE OVER THE CENTRAL PLAINS WILL LIFT NORTH TO THE
WESTERN GREAT LAKES TONIGHT. ITS ASSOCIATED COLD FRONT WILL CROSS
THE MS RIVER VALLEY THIS EVENING AND CROSS THE APPALACHIANS TOWARD
DAWN FRIDAY. THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL
INCREASE LATE TONIGHT AS THIS STRONG COLD FRONT APPROACHES.
THE HRRR MODEL INDICATING FOG/STRATUS SPREADING INTO THE EASTERN
MIDLANDS FROM THE COAST LATE THIS EVENING. IF THIS OCCURS A DENSE
FOG ADVISORY MAY BE NEEDED. LOW TEMPERATURES TONIGHT WILL BE
AROUND 60.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
A STRONG COLD FRONT WILL BE JUST WEST OF THE FORECAST AREA BY
FRIDAY MORNING...AND IS EXPECTED TO RAPIDLY MOVE THROUGH THE CWA
FROM THE MORNING INTO THE EARLY AFTERNOON. BY THE AFTERNOON THE
FRONT WILL BE MOVE MOVING EAST TO THE COAST AND OFFSHORE FRIDAY
NIGHT. THERE REMAINS A POTENTIAL FOR THUNDERSTORMS AHEAD OF THE
FRONT...MAINLY DUE TO THE LOW-LEVEL WINDS AROUND 850MB AT 50 TO 55
KNOTS. OTHER CONCERN IS FOR DRIER AIR QUICKLY OVERTAKING THE MID
LEVELS BEHIND THE FRONT. ONE NEGATIVE IN REGARDS TO STORMS IS THAT
THE MODELS ARE SHOWING MUCH OF THE STRONGER UPPER ENERGY LIFTING
NORTH OF THE AREA DURING THE MORNING. OVERALL CONCERN FOR SEVERE
POTENTIAL WITH FROPA IS STILL POSSIBLE AT THIS TIME BUT WILL
CONTINUE TO MONITOR.
HIGH TEMPERATURES WILL BE IN THE MID 60S FOR FRIDAY WITH TEMPERATURES
ONLY SLOWLY CLIMBING THROUGH THE MORNING AND THEN FALLING DURING THE
AFTERNOON. OVERNIGHT LOWS IN THE UPPER 30S TO THE LOWER 40S FRIDAY
NIGHT.
HIGH PRESSURE WILL BUILD IN OVER THE AREA FOR SATURDAY. COOLER WITH
HIGHS IN THE MIDDLE TO 60S. OVERNIGHT LOWS MAINLY IN THE LOWER TO
MIDDLE 40S SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
VERY FEW CHANGES IN THE EXTENDED FORECAST. NEAR ZONAL FLOW ALOFT
WITH WEAK IMPULSES WILL BE THE RULE SUNDAY THROUGH WEDNESDAY...WITH
A BROAD UPPER TROUGH DEVELOPING OVER THE SOUTHERN PLAINS BY
THURSDAY. OVERALL...WITH THE WEAK IMPULSES IN THE ZONAL
FLOW...EXPECT A SLIGHT CHANCE OF RAIN FOR PORTIONS OF THE LONG TERM
WITH SOME LOW CONFIDENCE WITH THE TIMING ISSUES. TEMPERATURES
THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
HIGH CONFIDENCE FOR VFR CONDITIONS ALL TERMINALS THROUGH AROUND
02Z.
GUSTY SOUTHERLY WINDS EXPECTED THIS AFTERNOON. WINDS TO DIMINISH
AROUND 23Z. THE HRRR MODEL...AND THE SREF MODEL...INDICATING
FOG/STRATUS SPREADING INTO THE EASTERN MIDLAND FROM THE COAST LATE
THIS EVENING. THUS HAVE INDICATED IFR CIGS DEVELOPING AT
OGB/CUB/CAE DURING THE 03Z-05Z TIME-FRAME. MVFR OR LOWER LOWER
CONDITIONS TO DEVELOP AT AGS/DNL AFTER 06Z AS LOW LEVEL MOISTURE
INCREASES AHEAD OF AN APPROACHING COLD FRONT.
GUIDANCE SUGGESTS VSBYS WILL ALSO GO DOWN INTO THE IFR RANGE BUT
NOT AS CONFIDENT GIVEN MODERATE SURFACE WINDS AS THE PRESSURE
GRADIENT INCREASES AHEAD OF THE FRONT. COULD SEE ISOLATED SHOWERS
AROUND THE TERMINALS 08Z-11Z... WITH WIDESPREAD SHOWER AND
THUNDERSTORMS CROSSING THE TAF SITES IN THE 12-16Z TIME-FRAME
AHEAD OF A STRONG COLD FRONT.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE SUNDAY NIGHT AND
AGAIN TUESDAY AS A COUPLE FRONTAL BOUNDARIES CROSS THE AREA.
&&
.CLIMATE...
HIGH TEMPERATURES THIS AFTERNOON APPROACHING DAILY RECORD VALUES.
AT CAE...RECORD HIGH FOR FEB 20TH IS 83 SET IN 1991.
AT AGS...RECORD HIGH FOR FEB 20TH IS 82 SET IN 1991.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
203 PM EST THU FEB 20 2014
.SYNOPSIS...
WARM TEMPERATURES CONTINUE ONCE AGAIN TODAY AHEAD OF AN
APPROACHING COLD FRONT. THIS STRONG COLD FRONT WILL CROSS THE
AREA FRIDAY BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS. HIGH
PRESSURE AND DRIER AIR WILL BUILD INTO THE REGION FRIDAY EVENING.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE HIGH PRESSURE WILL REMAIN OVER THE WESTERN ATLANTIC.
WE ARE EXPECTING NEAR RECORD HIGH TEMPERATURES UNDER SUNNY SKIES
THIS AFTERNOON. TEMPERATURES SHOULD PEAK IN THE MID 70S TO LOWER
80S.
LOW PRESSURE OVER THE CENTRAL PLAINS WILL LIFT NORTH TO THE
WESTERN GREAT LAKES TONIGHT. ITS ASSOCIATED COLD FRONT WILL CROSS
THE MS RIVER VALLEY THIS EVENING AND CROSS THE APPALACHIANS TOWARD
DAWN FRIDAY. THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL
INCREASE LATE TONIGHT AS THIS STRONG COLD FRONT APPROACHES.
THE HRRR MODEL INDICATING FOG/STRATUS SPREADING INTO THE EASTERN
MIDLANDS FROM THE COAST LATE THIS EVENING. IF THIS OCCURS A DENSE
FOG ADVISORY MAY BE NEEDED. LOW TEMPERATURES TONIGHT WILL BE
AROUND 60.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
LOW PRESSURE WILL MOVE INTO THE WESTERN GREAT LAKES THURSDAY NIGHT
AS AN ASSOCIATED COLD FRONT PUSHES ACROSS THE GULF STATES THURSDAY
NIGHT AND INTO THE FORECAST AREA FRIDAY MORNING AND INTO THE
AFTERNOON. BY THE AFTERNOON THE FRONT WILL MOVE TO THE COAST AND
OFFSHORE FRIDAY NIGHT. POTENTIAL FOR THUNDERSTORMS CONTINUES TO
SLOWLY INCREASE FOR COLD FRONT PASSAGE WITH CURRENT CONCERN
SURROUNDING SHEAR WITH WINDS AROUND 850MB NEARING 50 KNOTS. OTHER
CONCERN IS FOR DRIER AIR QUICKLY OVERTAKING THE MID LEVELS BEHIND
THE FRONT. OVERALL CONCERN FOR SEVERE POTENTIAL WITH FROPA REMAINS
LOW AT THIS TIME BUT WILL CONTINUE TO MONITOR. LOW TEMPERATURES
THURSDAY NIGHT MAINLY AROUND 60. HIGH TEMPERATURES WILL BE IN THE
MID 60S TO AROUND 70 FOR FRIDAY...WITH OVERNIGHT LOWS IN THE UPPER
30S TO THE LOWER 40S FRIDAY NIGHT.
HIGH PRESSURE WILL BUILD IN OVER THE AREA FOR SATURDAY. COOLER WITH
HIGHS IN THE LOWER TO MIDDLE 60S. OVERNIGHT LOWS IN THE LOWER TO
MIDDLE 40S SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MODELS THROUGH THE LONG TERM SEEM TO BE IN GOOD AGREEMENT WITH THE
SYNOPTIC PATTERN...HOWEVER HAVE SIGNIFICANT DIFFERENCES IN TIMING OF
MOISTURE ACROSS THE REGION. UPPER PATTERN FOR MUCH OF THE LONG TERM
REMAINS MOSTLY ZONAL WITH SOME SHORT WAVE ACTIVITY APPROACHING FROM
THE WEST. GFS MAY BE A BIT TOO AGGRESSIVE WITH INCREASED MOISTURE SO
WILL LEAN TOWARDS A DRIER SOLUTION FOR SUNDAY. WILL KEEP SLIGHT
CHANCE POPS MONDAY THROUGH TUESDAY AS A FRONTAL SYSTEM REMAINS JUST
SOUTH OF THE AREA. MAINLY DRY FOR WEDNESDAY. THE UNCERTAINTY
CONTINUES THROUGH THE REMAINDER OF THE LONG TERM RESULTING IN LOW
CONFIDENCE AND ONLY MINOR ADJUSTMENTS TO MONDAY THROUGH WEDNESDAY.
TEMPERATURES THROUGH THE LONG TERM WILL BE NEAR TO SLIGHTLY ABOVE
NORMAL.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
HIGH CONFIDENCE FOR VFR CONDITIONS ALL TERMINALS THROUGH AROUND
02Z.
GUSTY SOUTHERLY WINDS EXPECTED THIS AFTERNOON. WINDS TO DIMINISH
AROUND 23Z. THE HRRR MODEL...AND THE SREF MODEL...INDICATING
FOG/STRATUS SPREADING INTO THE EASTERN MIDLAND FROM THE COAST LATE
THIS EVENING. THUS HAVE INDICATED IFR CIGS DEVELOPING AT
OGB/CUB/CAE DURING THE 03Z-05Z TIME-FRAME. MVFR OR LOWER LOWER
CONDITIONS TO DEVELOP AT AGS/DNL AFTER 06Z AS LOW LEVEL MOISTURE
INCREASES AHEAD OF AN APPROACHING COLD FRONT.
GUIDANCE SUGGESTS VSBYS WILL ALSO GO DOWN INTO THE IFR RANGE BUT
NOT AS CONFIDENT GIVEN MODERATE SURFACE WINDS AS THE PRESSURE
GRADIENT INCREASES AHEAD OF THE FRONT. COULD SEE ISOLATED SHOWERS
AROUND THE TERMINALS 08Z-11Z... WITH WIDESPREAD SHOWER AND
THUNDERSTORMS CROSSING THE TAF SITES IN THE 12-16Z TIME-FRAME
AHEAD OF A STRONG COLD FRONT.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE SUNDAY NIGHT AND
AGAIN TUESDAY AS A COUPLE FRONTAL BOUNDARIES CROSS THE AREA.
&&
.CLIMATE...
HIGH TEMPERATURES THIS AFTERNOON APPROACHING DAILY RECORD VALUES.
AT CAE...RECORD HIGH FOR FEB 20TH IS 83 SET IN 1991.
AT AGS...RECORD HIGH FOR FEB 20TH IS 82 SET IN 1991.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
115 PM CST THU FEB 20 2014
.DISCUSSION...
1130 AM CST
UPDATED FORECAST GRIDS FOR THE AFTERNOON REFLECT HIGHER POPS AND
QPF BASED ON LATEST RADAR TRENDS AND PRONOUNCED LOW LEVEL MOISTURE
CONVERGENCE ACROSS THE AREA. AN INITIAL LINE OF SHOWERS AND STORMS
MOVED THROUGH EARLY THIS MORNING AND A SECOND BATCH IS CROSSING
THE AREA AROUND MIDDAY. EXPECT THE CURRENT ACTIVITY TO LINGER INTO
THE EARLY AFTERNOON ACROSS THE NORTHERN TWO THIRDS OF THE FORECAST
AREA. TWO BOUNDARIES HAVE YET TO CROSS THE AREA...THE WARM FRONT
LIFTING OUT OF SOUTHEAST IOWA AND CENTRAL ILLINOIS...AND THE COLD
FRONT ACROSS WESTERN MISSOURI. WITH EITHER OR BOTH OF THESE
BOUNDARIES THERE IS A GOOD CHANCE FOR ANOTHER LINE OF SHOWERS AND
POSSIBLE THUNDERSTORMS LATER THIS AFTERNOON.
THE ARRIVAL OF THE WARM FRONTAL BOUNDARY THIS AFTERNOON WILL
USHER IN VERY MOIST AIR WITH DEWPOINTS IN THE 50S. VSBYS AS LOW AS
1/4 TO 1/2 MILE ARE BEING REPORTED NEAR THIS FEATURE IN CENTRAL
ILLINOIS BUT FORTUNATELY THESE VALUES DO NOT APPEAR TO BE
WIDESPREAD. A DENSE FOG ADVISORY MAY YET BE REQUIRED THIS
AFTERNOON BUT FOR NOW WILL JUST PLAN TO MONITOR THE SITUATION FOR
WIDESPREAD DETERIORATING CONDITIONS.
THE ONSET OF STRONG WINDS TOWARD LATE AFTERNOON OR EVENING STILL
LOOKS ON TRACK. DIRECTION WOULD START AS SOUTHERLY AND THEN BECOME
SOUTHWESTERLY OVERNIGHT. GUSTS EXCEEDING 50 MPH ARE BEING
REPORTED IN SW MISSOURI.
LENNING
//PREV DISCUSSION...
534 AM CST
HAVE GOTTEN SEVERAL REPORTS OF THUNDERSNOW OUT OF THE NORTHERN
CHICAGO SUBURBS. ACARS SOUNDINGS OUT OF ORD WOULD SUPPORT ALL
RAIN...BUT WOULD SUSPECT THE STRONG LIFT WITH THE CONVECTION IS
LOCALLY COOLING THE COLUMN ENOUGH FOR A SWITCH OVER TO WHAT HAS
BEEN REPORTED AS A HEAVY VERY WET SNOW. COOP IN JUST NW OF
WOODSTOCK PICKED UP 1.3 INCHES OF SLUSH. AS THE HEAVIER
REFLECTIVITY SHIFTS EAST AND WAA CONTINUES WOULD EXPECT THE
THREAT OF +TSSN TO END SHORTLY. HAVE ISSUED A NOWCAST TO COVER
THIS THREAT THAT SHOULD (HOPEFULLY) BE ENDING IN THE NEXT 30-60
MINS.
IZZI
//PREV DISCUSSION...
324 AM CST
POTENTIALLY HIGH IMPACT...MULTIFACETED CYCLONE WILL CONTINUE TO
IMPACT THE REGION THROUGH TONIGHT. POTENTIAL EXISTS FOR HEAVY
RAINFALL (MAINLY THROUGH MID MORNING)...THUNDERSTORMS...A SQUALL
LINE AROUND 00Z THIS EVENING...THEN NON-CONVECTIVE STRONG/LOCALLY
DAMAGING WINDS THIS EVENING.
VERY STRONG LOW LEVEL JET (NEARLY 60KT @ 850MB) CONTINUES TO DRIVE
UNSEASONABLY MOIST AIR NORTHWARD INTO A LOOSELY ORGANIZED MCS
ONGOING OVER EASTERN IA/NORTHERN IL EARLY THIS MORNING. BEEN A
REMARKABLE AMOUNT OF CG LIGHTNING FOR THIS TIME OF YEAR WITH THIS
COMPLEX WITH WSR-88D DATA INDICATING A LOT OF POTENTIAL
GRAUPEL/SMALL HAIL ALOFT WITH THE HIGH DBZ ECHOS...THOUGH SOME OF
THAT COULD ALSO BE WET SNOW FLAKES MELTING.
MCS WILL TRAVERSE THE REGION EARLY THIS MORNING WITH SOME BACK
BUILDING POSSIBLY RESULTING IN PRECIP LINGERING INTO THE 15-18Z TIME
RANGE...BUT THE MAJORITY OF THE HEAVIEST PRECIP LIKELY DONE BEFORE
15Z. SHORT RANGE CONVECTIVE ALLOWING MODELS CONTINUE TO SUGGEST THAT
LOCALIZED RAINFALL TOTALS UP TO AROUND AN INCH ARE POSSIBLE WITH
THIS MCS...PARTICULARLY IN THE VICINITY OF THE I-80 CORRIDOR AND
THIS SEEMS TO BE SUPPORTED BY REGIONAL RADAR TRENDS. NOTE: USE THE
HOURLY AND STORM TOTAL PRECIP PRODUCTS FROM OUR RADAR THIS MORNING
WITH CAUTION...BRIGHT BANDING/GRAUPEL/SMALL HAIL ARE RESULTING IN
INFLATED VALUES BASED ON UPSTREAM SFC OBS.
JUST GET A REPORT OF SOME SPOTTY WET SNOW BETWEEN ELGIN IN RFD BY
WTVO MORNING MET ON HER WAY TO WORK...SO DEFINITELY SEEING SOME
SPOTTY WET SNOW/SLEET/GRAUPEL...BUT ANTICIPATE MOST OF THAT TO
QUICKY TRANSITION TO ALL RAIN AS WARM AIR ADVECTION CONTINUES. TEMPS
ARE MOSTLY IN THE MID 30S AND ALMOST ALL THE ROAD SFC TEMP DATA
SENSORS WE HAVE ACCESS TO SHOW PAVEMENT TEMPS ABOVE FREEZING...SO
ITS LOOKING LIKE WE WILL LARGELY DODGE A BULLET WITH ANY SNOW/ICE
PROBLEMS BRIEF AND CONFINED MOSTLY TO MORE RURAL AREAS OF NC IL.
THE INITIAL SHORTWAVE HELPING ORGANIZING THIS MORNING CONVECTION
SHOULD SHIFT EAST ALONG WITH THE NOSE OF THE LOW LEVEL JET...SO
SHOULD SEE WIDESPREAD AND HEAVIER PRECIP END FROM MID-LATE MORNING
THROUGH MUCH OF THE AFTERNOON. SHOULD STILL BE SOME SCTD/OCNL
SHOWERS IN THE CONTINUED WAA REGIME AS WARM FRONT INCHES NORTH.
DESPITE THE END OF THE HEAVIER MORE WIDESPREAD RAIN BEFORE
18Z...PLAN TO HANG ON TO FLOOD WATCH THRU 21Z TO COVER RUN OFF AND
SNOW MELT PROBLEMS THAT COULD LINGER INTO THE AFTERNOON AFTER THE
HEAVIER RAIN ENDS.
STILL LOOKS LIKELY THAT A STRONGLY FORCED LOW TOPPED LINE OF
CONVECTION WITH LITTLE/NO LIGHTNING ACCOMPANYING THE COLD FRONT WILL
SWEEP ACROSS THE CWA BETWEEN ABOUT 2230Z AND 0130Z. SFC BASED
INSTABILITY IS LIKELY TO BE LACKING...BUT THE EXTREMELY STRONG
FORCING WITH THE VERY DYNAMIC/EXPLOSIVELY DEEPENING SYSTEM STILL
LEAVES ME QUITE CONCERNED ABOUT WIND GUSTS OVER 60 MPH IN SPOTS WITH
THIS SQUALL LINE. IN THE WAKE OF THE SQUALL LINE VERY STRONG
PRESSURE GRADIENT AND IMPRESSIVE PRESSURE RISES WITH MODEST COLD AIR
ADVECTION/STEEP LOW LEVEL LAPSE RATES SHOULD ALLOW FOR A PERIOD OF
VERY STRONG WINDS THIS EVENING. TO PUT INTO PERSPECTIVE JUST HOW
IMPRESSIVE THIS STORM IS...A COLLEGUE AT WPC WHO HAS BEEN DOING WORK
WITH MINIMUM/MAXIMUM MONTHLY PRESSURE TOOK A QUICK LOOK AND INITIAL
FINDINGS INDICATE THAT THIS STORM WILL LIKELY BE THE DEEPEST
FEBRUARY LOW PRESSURE IN THIS REGION SINCE 1902!
HAVE OPTED TO UPGRADE THE HIGH WIND WATCH TO A WARNING FOR THIS
EVENING. NOT CONFIDENT THAT WE`LL MEET STRICT 58MPH GUST CRITERIA
EVERYWHERE...BUT SEEMS LIKELY AT LEAST SOME LOCATIONS WILL GUST TO
AROUND 60 MPH. THE FRINGE BENEFIT IS THAT THIS WARNING SHOULD COVER
ANY BRIEF CONVECTIVE 60+ MPH WIND GUSTS WITH THE LINE OF STRONGLY
FORCED SHOWERS ALONG THE COLD FRONT THIS EVENING AND ALLEVIATE
HAVING TO POTENTIALLY ISSUE SEVERE THUNDERSTORM WARNINGS FOR
LIGHTNING-LESS CONVECTION IF IT DOES END UP PRODUCING SEVERE GUSTS.
VERY STRONG WINDS WILL LIKELY CONTINUE BEYOND THE 05Z SCHEDULED
EXPIRATION TIME OF THE HIGH WIND WARNING...BUT LIKELY MORE IN THE
45-55 MPH RANGE AND FULLY ANTICIPATE THE HIGH WIND WARNING BEING
RAMPED DOWN TO A WIND ADVISORY THIS EVENING.
STRONG WINDS AND SEASONABLY COLD AIR ARE ON TAP FOR FRIDAY AS THE
MASSIVE THEN OCCLUDED CYCLONE FILLS AND GRADUALLY SPINS ITSELF DOWN.
MODELS ARE STILL HAVING FITS HANDLING WEAK SUBTLE WAVES TRACKING
ALONG THE SOUTHERN PERIPHERY OF THE HUDSON LOW...WITH GEM/GFS
HINTING AT SOME LIGHT ACCUMULATING SNOW OVER CENTRAL IL AND OUR
SOUTHERN CWA FRIDAY NIGHT...THEN NAM IS BY ITSELF ALL AMPED UP ABOUT
AN ACCUMULATING SNOW SAT NIGHT (AGAIN SOUTHERN HALF OF CWA)...THEN
ECMWF IS HITTING SNOW CHANCES HARD LATER MONDAY. CERTAINLY PLAUSIBLE
THAT WE COULD POTENTIALLY SEE ONE OR MORE BOUTS OF SOME ACCUMULATING
SNOW INTO EARLY NEXT WEEK...BUT UNTIL WE START TO GET A STRONGER
MORE CONSISTENT SIGNAL IN MODEL GUIDANCE IT IS HARD TO GO VERY HIGH
WITH POPS.
MEDIUM RANGE MODELS CONTINUE TO PAINT AN UNSEASONABLY COLD PICTURE
HEADING INTO NEXT WEEK. ECMWF/GFS BOTH FORECAST H8 TEMPS TO GET INTO
THE 3+ STANDARD DEVIATION BELOW AVERAGE TERRITORY...WHICH IF IT WERE
TO VERIFY COULD RESULT IN TEMPS THREATENING RECORDS BY THE MIDDLE OF
NEXT WEEK. CERTAINLY PLENTY OF TIME FOR MODELS TO BACK ON OF
MAGNITUDE OF THE COLD SOME...BUT THE GENERAL IDEA OF MUCH BELOW
AVERAGE TEMPS HEADING INTO THE LAST WEEK OF METEOROLOGICAL WINTER
LOOKS VERY LIKELY. SOME INDICATIONS ARE THAT THERE COULD BE ANOTHER
ACCUMULATING SNOW THREAT IN/NEAR THE AREA IN ADVANCE OF THE STRONGER
PUSH OF ARCTIC AIR TOWARD THE MIDDLE OF NEXT WEEK...BUT WITH SO MUCH
VARIABILITY OF THE EXACT MODEL DETAILS...THERE IS LITTLE TO HANG
YOUR HAT ON AT THIS TIME.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 19Z...
* 1/2 TO 1/4 SM VISIBILITIES IN FOG LIKELY THROUGH LATE
AFTERNOON/EARLY EVENING.
* IFR TO LIFR CIGS THROUGH THE AFTERNOON.
* MORE THUNDERSTORMS POSSIBLE LATER THIS AFTERNOON INTO THE EARLY
EVENING.
* VERY STRONG WEST-SOUTHWEST WINDS SETTING UP EARLY THIS EVENING
WITH GUSTS AS HIGH AS 50 KT OUT OF THE SOUTHWEST.
* PERIOD OF LIGHT SNOW LATE TONIGHT INTO FRIDAY MORNING.
KJB
//DISCUSSION...UPDATED 19Z...
ALREADY MADE AN UPDATE TO THE 18 UTC TAFS BASED ON OBS TO THE
SOUTH. IT APPEARS MUCH MORE LIKELY THAT DENSE FOG WITH VIS OF 1/2
TO 1/4 SM WILL DEVELOP ACROSS THE TERMINALS. IN FACT THE LATEST
OBSERVATION OUT OF MDW INDICATES THEY ARE ALREADY THERE...SO ORD
AND DPA WILL BE IN IT WITHIN THE NEXT COUPLE HOURS. IT APPEARS
THAT THIS FOG WILL LAST FOR SEVERAL HOURS THIS AFTERNOON...LIKELY
UNTIL THE LINE OF THUNDERSTORMS CURRENTLY ACROSS MISSOURI GETS
HERE LATER THIS AFTERNOON AROUND 22-23 UTC.
KB
//DISCUSSION...UPDATED 18Z...
A VERY POWERFUL STORM SYSTEM WILL IMPACT THE REGION THROUGH MUCH OF
THE PERIOD. THIS WILL RESULT IN PERIODS OF RAIN AND EMBEDDED
THUNDERSTORMS THIS AFTERNOON...ALONG WITH IFR TO LIFR CIGS AND
IFR TO LIFR VISIBILITIES. A SURFACE WARM FRONT...ASSOCIATED WITH
THE STORM SYSTEM...WILL LIFT NORTHWARD ACROSS THE TAF SITES BY MID
TO LATE AFTERNOON. DEW POINTS ARE EXPECTED TO SPIKE WELL INTO THE
40S IN THE WAKE OF THIS FRONT AS MOISTURE SURGES NORTHWARD. THIS
COULD SET THE STAGE FOR A FEW HOUR PERIOD OF DENSE FOG ACROSS THE
AREA LATER THIS AFTERNOON AND EARLY EVENING AS THESE HIGH DEW
POINTS MOVE OVER THE SNOW PACK...ESSENTIALLY SATURATING THE LOW
LEVELS.
THE RAIN CURRENTLY MOVING ACROSS THE AREA DOES HAVE A FEW EMBEDDED
LIGHTENING STRIKES. IN SPITE OF THIS...I LEFT THE MENTION OF TSRA OUT
OF THE NEW TAF FOR THE NEXT FEW HOURS...MENTIONING ONLY PREVAILING
SHOWERS OF RAIN. I EXPECT THIS ACTIVITY TO CONTINUE ACROSS THE
REGION FOR THE NEXT COUPLE HOURS...INTO THE EARLY AFTERNOON HOURS.
THEREAFTER...SOME FOG IS LIKELY TO REDUCE VISIBILITIES THROUGH THE
REST OF THE AFTERNOON. IT IS POSSIBLE FOR VISIBILITIES TO DROP WELL
BELOW A MILE IN FOG LATER THIS AFTERNOON...AS THE HIGHER DEW POINTS
STREAM NORTHWARD. HOWEVER...CONFIDENCE IN HOW DENSE THE FOG WILL
BECOME IS STILL SOMEWHAT LOW. THEREFORE I HAVE REMAINED
OPTIMISTIC...ONLY MENTIONING VIS DOWN AROUND 3/4 SM IN THE GOING
TAFS.
A STRONG COLD FRONT IS SET TO PUSH ACROSS THE AREA EARLY THIS
EVENING. THIS COULD RESULT IN ANOTHER VERY QUICK HIT OF SHOWERS AND
THUNDERSTORMS ALONG AND AHEAD OF THIS FRONT. HOWEVER...THE MAIN
STORY WILL BE THE VERY STRONG WINDS SETTING UP RIGHT BEHIND THIS
FRONT. WINDS WILL QUICKLY SHIFT OUT OF THE SOUTHWEST AND BECOME VERY
GUSTY AFTER 02 TO 03 UTC THIS EVENING. IN FACT...GUSTS COULD BE
CLOSE TO 50 KT FOR A COUPLE HOUR PERIOD THIS EVENING...BEFORE THEY
EASE SOME OVERNIGHT. THESE STRONG GUSTY WINDS WILL LIKELY REMAIN
GUSTY UP AROUND 36 KT THROUGH FRIDAY AS THE SURFACE LOW CONTINUES TO
STRENGTHEN AS IT MOVES NORTHWARD ACROSS THE UPPER GREAT LAKES
REGION.
ALTHOUGH VISIBILITIES AND CIGS SHOULD IMPROVE FOLLOWING THE FRONTAL
PASSAGE THIS EVENING...MOISTURE RAPPING AROUND THE LARGE STRONG AREA
OF LOW PRESSURE COULD RESULT IN A PERIOD OF SNOW ACROSS THE AREA
VERY LATE TONIGHT INTO FRIDAY MORNING. THIS COULD LEAD TO LOWER VIS
IN SNOW AND BLSN...WITH SOME MINOR ACCUMULATIONS POSSIBLE.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 19Z...
* HIGH FOR PERIODS OF FOG WITH VIS 1/2 SM OR LESS THROUGH THE REST
OF THE AFTERNOON.
* MEDIUM WITH RAIN/THUNDERSTORM TIMING LATER THIS AFTERNOON AND
EARLY EVENING.
* MEDIUM TO HIGH WITH CEILINGS.
* MEDIUM TO HIGH WITH WIND DIRECTION/SPEED.
* MEDIUM ON PERIOD OF SNOW LATE TONIGHT INTO EARLY FRIDAY.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...SLIGHT CHANCE OF LIGHT SNOW...OTHERWISE VFR.
TUESDAY...VFR.
WEDNESDAY...VFR.
RODRIGUEZ
&&
.MARINE...
448 AM CST
VERY STRONG WINDS EXPECTED OVER THE ENTIRE LAKE WHICH INCLUDES THE
NEARSHORE AND OPEN WATERS LATER THIS AFTERNOON INTO FRIDAY.
AS APPROACHING LOW PRESSURE OVER THE CENTRAL PLAINS TAKES SHAPE
THIS MORNING...LIGHTER SOUTHEAST WINDS CURRENTLY BEING OBSERVED
OVER THE LAKE. ALTHOUGH AS THIS LOW APPROACHES AND STRENGTHENS
TODAY...WINDS WILL STEADILY INCREASE WITH GALES LIKELY BY LATE
THIS AFTERNOON. GALES WILL THEN CONTINUE INCREASING WITH THIS
STRENGTHENING LOW THIS EVENING...WHILE TURNING MORE SOUTHERLY.
WITH COLDER AIR MOVING OVER THE LAKE THIS EVENING...WINDS WILL
STRENGTHEN TO STORM FORCE AS THEY TURN TO THE SOUTHWEST. STORM
FORCE WINDS WILL THEN BE OBSERVED OVER THE OPEN WATERS THROUGH
FRIDAY AFTERNOON...WITH SOME UNCERTAINTY AS TO THE DURATION OF THE
STORM FORCE WINDS OVER THE NEARSHORE. CURRENTLY HAVE STORM FORCE
WINDS AND THE WARNING FOR TONIGHT...BUT ITS POSSIBLE THIS MAY NEED
TO BE EXTENDED IN THE NEARSHORE. GALES WILL THEN BE LIKELY INTO
FRIDAY EVENING FOR THE OPEN WATERS...AND THROUGH FRIDAY FOR THE
NEARSHORE.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLOOD WATCH...ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-
ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 3 PM
THURSDAY.
HIGH WIND WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039...5 PM THURSDAY TO 11 PM
THURSDAY.
IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 3 PM
THURSDAY.
HIGH WIND WARNING...INZ001-INZ002-INZ010-INZ011-INZ019...5 PM
THURSDAY TO 11 PM THURSDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL MIDNIGHT FRIDAY.
STORM WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...MIDNIGHT FRIDAY TO 3
PM FRIDAY.
GALE WARNING...NEARSHORE WATERS UNTIL 9
PM THURSDAY.
STORM WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...9 PM
THURSDAY TO 4 AM FRIDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
115 PM CST Thu Feb 20 2014
.MESOSCALE DISCUSSION...
ISSUED 114 PM CST Thu Feb 20 2014
Warm front getting a substantial push northward and is starting to
come into Bloomington. Still have mid to upper 30s to the north,
but widespread upper 50s to near 60 south. Dew points of 50 degrees
now as far north as Lincoln.
Line of thunderstorms rapidly filling in across central Missouri,
in an area where some clearing helped destabilize the atmosphere,
with surface based CAPE`s around 1000 J/kg per SPC mesoanalysis
page. HRRR has been doing a good job with the development and
placement of this line. HRRR and extrapolation tool on AWIPS
indicate the line should move into the western CWA between 2:30
and 3 pm and reach the eastern counties between 4-5 pm. Still
several inches of snow cover across the north which will help
stabilize things, but Springfield has lost 4 inches of snow depth
just this morning and much of what`s left will be gone very soon,
helping with the instability. RAP model showing MUCAPE`s around
800 J/kg across the central and southeast CWA by mid afternoon,
helping to sustain the storms. VAD wind profile off our radar
showing 55 knots at the 925 mb level, so plenty of wind in the low
levels for the storms to try and bring downward toward the
surface.
Geelhart
&&
.AVIATION...
ISSUED 1155 AM CST Thu Feb 20 2014
Warm front has lifted just north of KSPI/KDEC/KCMI, shifting winds
back around to the south and gusting to around 25-30 knots, while
east winds around 10 knots continue further north. Should see the
front continue to lift northward over the next couple of hours.
Have had some areas of dense fog primarily north of the front, as
a significant increase in low level moisture moves in with the
front, but this is likely to fade out in the next couple hours.
Line of convection starting to form in central Missouri, and will
move east through central Illinois mid to late afternoon. Have
included about a 3 hour period of VCTS at each TAF site for now,
and will update later to narrow down the time frame once the line
becomes more mature. A cold front will pass by shortly behind the
line of storms, switching winds to the west. Still looks like
gusts of 35-45 knots will be likely this evening, as impressive
pressure rises spread across the state in the wake of a deepening
low pressure passage. Wraparound snow showers may spread as far
south as KPIA/KBMI after 06Z. Have maintained the MVFR conditions
through the night, before improvement early Friday morning. Winds
by Friday morning not quite as high, but still gusting in the 30
knot vicinity.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 1010 AM CST Thu Feb 20 2014
Warm frontal boundary is waffling along the I-72 corridor this
morning, with 40s and 50s south and 30s to the north. Most of the
precipitation over the last few hours has been on the cold side of
the storm, especially across the far northwest CWA where
thunderstorms have produced some pea size hail as well. That
particular area has received 1 to 1.5 inches of rain since
yesterday evening. The front extends to parent low pressure along
the Kansas/Missouri border.
Focus remains with the winds, precipitation and temperature
trends. Have sent some zone/grid updates recently to reflect a
period of lower PoP`s into early afternoon, and as the front lifts
northward, before the main activity develops toward mid to late
afternoon. Latest Day1 convective outlook pushed the slight risk
back northwest to around Shelbyville, reflective of the slower
arrival of the cold front, with damaging winds still the primary
threat. The cold front should push to around I-57 by sunset and
exit the state shortly after that. The post-frontal period is when
the winds will really start ramping up, as the low experiences
substantial and rapid intensification this afternoon as it moves
into southwest Wisconsin. 3-hour pressure rises of around 10 mb
will push through Missouri late this afternoon and across the CWA
early this evening. Wind gusts outside the storms still look to
reach around 45 mph by late afternoon and 50-60 mph this evening.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 3 AM CST Friday FOR ILZ056-061>063-066>068-
071>073.
HIGH WIND WARNING until 3 AM CST Friday FOR ILZ027>031-036>038-
040>055-057.
FLOOD WATCH until 6 PM CST this evening FOR ILZ027>031-036>038-
040>053.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1213 AM CST THU FEB 20 2014
.DISCUSSION...
918 PM CST
EVENING UPDATE...
KEY UPDATE THIS EVENING IS THAT WE WILL BE HOISTING A HIGH WIND
WATCH FOR THE ENTIRE AREA STARTING AT 00Z TOMORROW EVENING.
INTENSE WARM ADVECTION DRIVEN PRECIP CURRENTLY ACROSS SOUTHERN IA
AND NORTHERN MO AHEAD OF DEVELOPING SURFACE LOW OVER CENTRAL
PLAINS WILL OVERSPREAD AREA LATE TONIGHT. BIGGEST CONCERN IS WITH
SURFACE TEMPERATURES ESPECIALLY NORTH OF INTERSTATE 80 AND ALSO
TEMPERATURES ALOFT DUE TO EVAPORATIONAL/DYNAMIC COOLING MAINLY
ALONG/NORTH OF I-88 AS PRECIP BEGINS. SURFACE WET BULB 0 VALUES
WITH DEWPOINTS CURRENTLY IN THE 20S NORTH OF I-80 WILL BE AT OR
BELOW FREEZING UNTIL 12Z OR SO WE ADDED IN FREEZING MENTION ALONG
I-80 CORRIDOR. STRONG WARM SURGE WITH H8 TEMPS WARMING TO +6 OR
+7C FROM SOUTH SHOULD AID IN WARMING ENTIRE COLUMN ABOVE FREEZING
BY DAYBREAK. FARTHER NORTH/ALONG NORTH OF I-88...DRY EAST FLOW
ALOFT WILL CAUSE COLUMN TO COOL TO OR BELOW FREEZING AS IT TRIES
TO SATURATE. THUS THERE COULD BE A BURST OF ACCUMULATING
SNOW/SLEET...FOLLOWED BY TRANSITION TO ZR AND THEN PLAIN RAIN BY
14 TO 15Z TOMORROW. WOULD EXPECT IMMEDIATE DOWNTOWN CHICAGO TO BE
AT LESS OF A THREAT OF SNOW AND BRIEF ICE ACCUMS DUE TO VERY MILD
TEMPS THE PAST FEW DAYS. SURFACE TEMPS WILL NEED TO BE MONITORED
CLOSELY REGARDING POTENTIAL FOR ZR TO HOLD ON A BIT LONGER IN
PARTS OF FAR NORTHERN IL TOMORROW AM. WILL CONTINUE WITH SPS FOR
SNOW/ICE THREAT.
STILL ON TRACK FOR RAPID WARM UP TOMORROW AFTERNOON...WHICH COULD
RESULT IN AREAS OF DENSE FOG BUT MORE IMPORTANTLY ACCELERATE
SNOWMELT ON TOP OF WHAT OCCURRED WITH THE HEAVY RAIN IN THE AM.
THUS HAVE MADE NO CHANGES TO FLOOD WATCH. ISOLATED TSRA ARE
POSSIBLE IN STEEP MIDLEVEL LAPSE RATES UNDER DRY SLOT OF
INTENSIFYING CYCLONE.
FINALLY...REGARDING WINDS...VERY IMPRESSIVE SET-UP AS LOW LIFTS TO
SOUTHERN WI TOMORROW EVENING SWINGING POWERFUL COLD FRONT THROUGH
AREA. VERY SHARP CAA AND STRONG ISALLOBARIC PRESSURE RISES WILL
MAKE IT MUCH EASIER TO TAP INTO 50+ KT WINDS AT TOP OF THE
CHANNEL. SUSTAINED WESTERLY WIND SPEEDS COULD ALSO BE UP TO 30 KT.
THUS WITH POTENTIAL FOR 50+ KT GUSTS AND 30+ KT SUSTAINED
SPEEDS...WILL HOIST HIGH WIND WATCH FOR ENTIRE CWA STARTING 00Z
THURSDAY EVENING. WATCH ENDS A BIT EARLIER IN THE FAR SOUTH WHERE
WINDS MAY DIMINISH SLIGHTLY SOONER...BUT GOES TO 12Z FRIDAY FOR
MOST OF THE AREA.
RC
//PREV DISCUSSION...
303 PM CST
SHORT TERM...TONIGHT THROUGH THURSDAY PM...
A VERY DYNAMIC AND COMPLEX STORM SYSTEM WILL IMPACT THE AREA LATE
TONIGHT THROUGH THURSDAY EVENING. THIS WILL PRESENT A PLETHORA OF
FORECAST CONCERNS OVER THE NEXT 24 TO 36 HOURS. THESE INCLUDE:
1.) THE THREAT FOR ACCUMULATING SNOW AND ICE AT THE ONSET OVERNIGHT
TONIGHT...PARTICULARLY ACROSS FAR NORTHERN ILLINOIS ALONG AND NORTH
OF INTERSTATE 88.
2.)RAINFALL AMOUNTS AND HYDRO ISSUES ON THURSDAY.
3.)POTENTIAL FOR SOME STRONG THUNDERSTORMS THURSDAY AFTERNOON.
4.)POTENTIAL FOR AREAS OF FOG ON THURSDAY.
5.)THE SYNOPTIC WINDS ON THE BACK SIDE OF THE SYSTEM LATE THURSDAY
AFTERNOON AND INTO THURSDAY NIGHT.
THE 12 UTC GLOBAL MODELS HAVE THE BEST HANDLE ON THE EVOLUTION AND
TRACK OF THIS STORM SYSTEM OVER THE NEXT 36 HOURS. AS SUCH...THE 12
UTC NAM WAS A FAR EAST OUTLIER ON THE SURFACE LOW TRACK. IN MOST
CASES...THE 12 UTC NAM WAS A GOOD 100 TO 150 MILES EAST OF THE
GLOBAL MODELS AND ENSEMBLE SOLUTIONS...SO THE 12 UTC NAM WAS NOT
FOLLOWED.
OVERALL...CYCLOGENESIS WILL SET UP ACROSS THE FRONT RANGE OF THE
COLORADO ROCKIES THIS EVENING IN ASSOCIATION WITH A STOUT SHORT WAVE
DISTURBANCE...NOW PUSHING ACROSS THE INTER-MOUNTAIN WEST. THIS WILL
RESULT IN A SURFACE LOW AROUND 992 MB...WHICH SHOULD PUSH EASTWARD
ACROSS THE KANSAS OKLAHOMA STATE LINE OVERNIGHT. THE MID LEVEL
SYSTEM WILL BE FORCED TO BECOME NEGATIVELY TILTED AS IT ENCOUNTERS
RAPIDLY BUILDING HIGHS ACROSS THE GREAT LAKES REGION EARLY THURSDAY.
AS A RESULT...THE SURFACE LOW WILL DEVELOP EXPLOSIVELY...WITH THE
CENTRAL PRESSURE EXPECTED TO DROP NEARLY 12 MB IN 12 HOURS AS THE
LOW LIFTS NORTHEASTWARD TO SOUTHEASTERN WISCONSIN BY EARLY THURSDAY
EVENING. THE LOW WILL LIKELY CONTINUE DEEPENING TO AROUND 970 MB BY
FRIDAY MORNING AS IT MOVES ACROSS THE UPPER GREAT LAKES REGION.
THE RAPID DEEPENING OF THE CENTRAL PRESSURE OF THIS LOW ALONE SAYS
THAT THIS WILL BE A NOTABLE WEATHER MAKER FOR MUCH OF THE CENTRAL
CONUS. PRECIPITATION WILL LIKELY ONSET QUICKLY ACROSS MOST OF
ILLINOIS AND INTO INDIANA TONIGHT AFTER 1 OR 2 IN THE MORNING AS 45
TO 50 KT LOW LEVEL JET DEVELOPS AND NOSES INTO THE REGION. THIS WILL
SET UP A VERY IMPRESSIVE SURGE OF GULF MOISTURE...WITH PWATS QUICKLY
INCREASING FROM ONLY A TENTH OR TWO OF AN INCH...TWO AROUND 1 INCH
BY DAYBREAK THURSDAY. CLIMATOLOGICALLY SPEAKING...1 INCH PWATS THIS
TIME OF YEAR RANK IN THE 99 TH PERCENTILE...SO HEAVY RAINFALL WILL
DEFINITELY BE A CONCERN. FOR MORE INFO ON THE HYDRO...SEE THE HYDRO
DISCUSSION BELOW.
THERE CONTINUES TO BE CONCERNS OF A WINTER MIX OF SNOW...FREEZING
RAIN AND SLEET AT THE ONSET OF THE PRECIPITATION
OVERNIGHT...PARTICULARLY AREAS ALONG AND NORTH OF INTERSTATE 88. IT
APPEARS THAT STRONG DYNAMIC FORCING WILL SET UP ALONG THE NOSE OF
THE LOW LEVEL JET...AND THIS STRONG FORCING COMBINED WITH
EVAPORATION COOLING COULD RESULT IN A COLUMN COLD ENOUGH FOR ALL
SNOW...ESPECIALLY CLOSER TO THE WISCONSIN BOARDER. THIS COULD RESULT
IN A PERIOD OF MODERATE TO HEAVY SNOW AND SLEET ACROSS FAR NORTHERN
ILLINOIS TONIGHT INTO VERY EARLY THURSDAY MORNING BEFORE THE WARM
SURGE KICKS NORTHWARD...CHANGING EVERYTHING OVER TO LIQUID. MODEL
BUFFER SOUNDINGS ACROSS THIS REGION ARE VERY CONCERNING...WITH THE
PROFILES INDICATING A NEARLY ISOTHERMAL LAYER FROM THE SURFACE UP TO
AROUND 700 MB HUGGING THE FREEZING POINT...AND VERY STEEP MID LEVEL
LAPSE RATES ABOVE THIS ISOTHERMAL LAYER. SO ALTHOUGH THERE MAY ONLY
BE A COUPLE HOUR PERIOD SUPPORTIVE OF SNOW...SLEET AND FREEZING
RAIN...THERE COULD BE A FEW INCHES OF SNOW ACCUMULATION AND A FEW
HUNDREDTHS OF AN INCH OF ICE ACCUMULATION FAR NORTH PRIOR TO THE
CHANGE OVER TO RAIN...ESPECIALLY WITH ANY CONVECTIVE ELEMENTS.
CONFIDENCE REMAINS LOW...BUT I HAVE ADDED SOME SNOW AND ICE
ACCUMULATIONS INTO THE FORECAST...WITH THE POTENTIAL OF SOME RAPID
SNOW ACCUMULATIONS. I WILL HIGHLIGHT THIS THREAT IN AN SPS...AND
PASS ALONG THE CONCERNS TO THE EVENING SHIFT TO SEE IF ANY WINTER WX
HEADLINE WILL BE NEEDED.
ANY WINTER PRECIP WILL QUICKLY COME TO AN END EARLY THURSDAY
MORNING...WITH PERIODS OF RAIN AND THUNDERSTORMS THROUGH THE
REMAINDER OF THE MORNING AS THE WARM FRONT SHIFTS ACROSS NORTHERN
ILLINOIS. IN ADDITION TO THE THUNDERSTORMS AND HEAVY RAIN
POTENTIAL...THERE IS A THREAT OF FOG...ESPECIALLY IN THE VICINITY
OF THE WARM FRONT AND SURFACE LOW. A STRONG COLD FRONT WILL BEGIN TO
PUSH ACROSS THE AREA DURING THE AFTERNOON...AND THIS LOOKS TO BE THE
FOCUS FOR A LINE OF STORMS. IT CURRENTLY APPEARS THE BETTER THREAT
FOR MORE WIDESPREAD SEVERE STORMS WILL BE SOUTH OF THE AREA. THE
EXTENSIVE SNOW PACK ACROSS THE AREA MAY RESULT IN A NEAR SURFACE
INVERSION THAT MAY KEEP THE STORMS FROM ROOTING THEMSELVES IN THE
BOUNDARY LAYER. BECAUSE OF THIS...ALTHOUGH THE WINDS WILL BE
SCREAMING UP OVER 50 KT OFF THE SURFACE...THEY MAY HAVE A HARD TIME
BEING FORCED TO THE GROUND WITH THE STORMS. THEREFORE...ALTHOUGH
SOME ISOLATED SEVERE WIND GUSTS ARE POSSIBLE WITH THESE AFTERNOON
SHOWERS/STORMS...IT APPEARS THE MORE WIDESPREAD ACTIVITY WILL REMAIN
SOUTH OF MUCH OF THE AREA.
A DRY MID LEVEL DRY SLOT WILL PUSH IN ACROSS THE AREA BY EARLY
THURSDAY EVENING...AND THIS SHOULD BRING AN END TO THE
PRECIP...WITH THE EXCEPTION OF FAR NORTH CENTRAL ILLINOIS...WHERE
SOME RAP AROUND SNOW SHOWERS ARE POSSIBLE IN ASSOCIATION WITH THE
MID LEVEL DEFORMATION ZONE.
THE MAIN STORY THURSDAY EVENING...HOWEVER...WILL BE THE STRONG
SYNOPTIC WINDS IN THE WAKE OF THE COLD FRONT. THE TRACK OF THE
SURFACE LOW WILL PLACE NORTHERN ILLINOIS/NORTHWESTERN INDIANA IN A
VERY FAVORABLE LOCATION FOR VERY STRONG SYNOPTIC WINDS THURSDAY
EVENING. ISOBARIC PRESSURE RISES ON THE ORDER OF 14+ MB IN A 6 HOUR
PERIOD ARE EXPECTED TO OVERSPREAD THE AREA. THIS COULD LEAD TO TOP
OF THE CHANNEL TYPE MIXING FOR A FEW HOURS FOLLOWING THE THE COLD
FRONTAL PASSAGE EARLY THURSDAY EVENING. AS SUCH...THIS COULD LEAD TO
50+ KT WIND GUSTS ACROSS THE AREA FOR A PERIOD THURSDAY EVENING. IN
SPITE OF THIS...I WILL LET THE OVERNIGHT SHIFT GET ANOTHER LOOK AT
THIS POTENTIAL TO SEE IF EITHER A WIND ADVISORY OR HIGH WIND
WARNING WILL BE NEEDED FOR THIS PERIOD.
KJB
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY...
300 PM...STRONG LOW PRESSURE OVER WISCONSIN WILL CONTINUE TO
DEEPEN THURSDAY NIGHT AS IT LIFTS NORTH TO LAKE SUPERIOR. THE
GRADIENT WILL REMAIN TIGHT THROUGH FRIDAY AFTERNOON WITH WESTERLY
WINDS 20-30 MPH WITH HIGHER GUSTS INTO THE 40 MPH RANGE. THERE
REMAINS A SMALL POTENTIAL FOR LIGHT SNOW OR SNOW SHOWERS LATE
THURSDAY NIGHT INTO EARLY FRIDAY MORNING MAINLY ACROSS THE NORTH
HALF/THIRD OF THE CWA. ANY AMOUNTS WILL BE LIGHT BUT WITH THE
CONTINUED STRONG WINDS...ANY FRESH SNOW WILL LIKELY CAUSE SOME
BLOWING/DRIFTING SNOW.
A WEAKER COLD FRONT/TROUGH WILL PASS ACROSS THE REGION FRIDAY
EVENING...BRINGING ANOTHER CHANCE OF LIGHT SNOW/SNOW SHOWERS AND
HAVE ADDED THIS TO THE FORECAST...BUT PRIOR TO ITS ARRIVAL...WEAK
WARM AIR ADVECTION WILL SPREAD ACROSS THE AREA WITH AT LEAST SOME
SUNSHINE THROUGH MIDDAY. HAVE BUMPED HIGH TEMPS UP A TAD INTO THE
MID/UPPER 30S ACROSS MUCH OF THE CWA BUT THIS IS STILL A FEW
DEGREES BELOW CURRENT GUIDANCE LEVELS AND MAY END UP BEING TOO
COOL.
COLDER AIR THEN SPREADS BACK ACROSS THE REGION THIS WEEKEND WITH
BELOW NORMAL/MUCH COLDER TEMPERATURES THROUGH THE MIDDLE OF NEXT
WEEK WITH HIGHS GENERALLY IN THE 20S AND LOWS IN THE SINGLE DIGITS.
ECMWF/GFS HAVE BEEN SOMEWHAT CONSISTENT WITH A CLIPPER LIKE SYSTEM
MOVING ACROSS THE AREA MONDAY NIGHT WITH A TENTH OR TWO OF QPF.
THIS COULD EASILY FLUFF UP A FEW INCHES OF SNOW. HAVE MAINTAINED
GOING CHANCE POPS AS THE TREND HAS BEEN FOR IT TO SAG A LITTLE
FURTHER SOUTH AND PERHAPS AFFECT ONLY THE SOUTHERN PART OF THE CWA.
MODELS THAN DIFFER ON JUST HOW COLD THE NEXT PUNCH OF ARCTIC AIR
WILL BE WHEN IT ARRIVES WEDNESDAY/WEDNESDAY NIGHT. CMS
&&
.HYDROLOGY...
330 PM CST...THE STRONG LATE WINTER STORM SYSTEM IS EXPECTED TO
BRING CONDITIONS THAT WOULD BE CONDUCIVE TO THE POTENTIAL FOR
WIDESPREAD AREAL AND RIVER FLOODING TO NORTHERN ILLINOIS AND
NORTHWEST INDIANA.
PRECIPITATION IS EXPECTED TO BEGIN DURING THE EARLY MORNING HOURS
AND WILL INITIALLY BE A WINTRY MIX WITH LIGHT QPF AMOUNTS. THROUGH
THE MORNING AND INTO THE AFTERNOON...AS THE MAIN SFC LOW DEEPENS...
THE ASSOCIATED WARM FRONT WILL SURGE NORTH INTO WISCONSIN AND SET
UP A PERSISTENT FETCH OF WARM...MOIST AIR FROM A WIDE OPEN WESTERN
GLFMEX REGION. CURRENT INDICATORS SUGGEST THAT TEMPERATURES WILL
SURGE INTO THE UPPER 40S NEAR THE WISCONSIN BORDER TO THE MIDDLE
50S SOUTH OF THE ILLINOIS AND KANKAKEE RIVER VALLEYS. SFC
DEWPOINTS WILL ALSO SURGE INTO THE MIDDLE 40S TO AROUND 50F. THE
MODEL GUIDANCE SUGGESTS THAT PRECIPITABLE WATER VALUES WILL
APPROACH 1 INCH TOMORROW...WHICH IS AT LEAST 2 STANDARD DEVIATIONS
HIGHER THAN NORMAL FOR LATE FEBRUARY. THE HIGH PRECIPITABLE WATER
VALUES AND THE DYNAMIC SYSTEM ARE INDICATIVE THAT THE POTENTIAL
FOR A SIGNIFICANT AMOUNT OF LIQUID PRECIPITATION...WITH THE
CURRENT FORECAST CARRYING 0.75 TO 1.00 INCHES FOR THE PERIOD
FROM 09Z THURSDAY THROUGH 00Z FRIDAY. THE HEAVY RAIN WILL HAVE AN
IMPACT ON BOTH AREAL FLOOD AND RIVER FLOOD CONCERNS.
THE WARM...HIGH DEWPOINT AIR IS VERY EFFICIENT AT MELTING SNOW
AND...CURRENTLY...THERE IS 2 TO 4 INCHES OF LIQUID EQUIVALENT
TRAPPED IN THE SNOW PACK. THIS...COMBINED WITH AROUND 1 INCH OF
WIDESPREAD QPF...WOULD GIVE A WORST CASE SCENARIO OF 3 TO 5 INCHES
OF RAINFALL. HOWEVER...THERE ARE LIMITING AND COMPLICATING FACTORS
WHICH NEED TO PLAY OUT...WHICH WOULD ACT TO EITHER LIMIT THE FLOOD
POTENTIAL OR ENHANCE THE FLOOD POTENTIAL...ESPECIALLY FOR AREA
RIVERS. CURRENTLY...MOST AREA RIVERS AND STREAMS ARE EITHER TOTALLY
ICE COVERED OR ONLY HAVE VERY LIMITED AMOUNTS OF OPEN WATER...SINCE
THIS WINTER HAS SEEN AN UNUSUAL DEGREE OF EXTREME COLD. EVEN THE
ILLINOIS RIVER HAS MUCH MORE ICE COVERAGE THAN IS NORMALLY OBSERVED
IN A TYPICAL WINTER. HEAVY RAINFALL AND ICE COVERED RIVERS WILL
HAVE A TWO-FOLD IMPACT. THE CAPACITY OF ICE COVERED RIVERS IS MUCH
LOWER THAN OPEN RIVERS WITH THE RAIN COLLECTING ON TOP OF THE ICE AS
IT IT WERE A RIVER BED. SO...LESS RAINFALL WOULD BE NEEDED TO RAISE
WATER LEVELS ABOVE BANK FULL AND TO FLOOD STAGE. ALSO...THE RAINFALL
WILL INCREASE BASE FLOW AND INFILTRATION OF RAINFALL INTO THE
RIVERS...LEADING TO INCREASED STREAM FLOW RATES...INCREASING
HYDROSTATIC PRESSURE UNDER THE ICE...WHICH COULD THEN LEAD TO ICE
BREAKUP AND ICE JAM FLOODING. ANY ICE JAM FLOODING WOULD ONLY
COMPOUND ANY RIVER FLOODING CAUSED BY THE RAINFALL RUNNING OFF ON
TOP OF THE ICE. HOWEVER...SINCE THE FROST DEPTH IS AROUND 14 INCHES
ACROSS THE AREA...IT IS UNLIKELY THAT THE INFLUX OF WARM AIR AND
RAIN WILL HAVE A SIGNIFICANT IMPACT ON THE FROST DEPTH. SO...ANY
MELTING AND RAINFALL WILL LIKELY MOSTLY BECOME RUNOFF...RATHER THAN
BEING INCORPORATED INTO INCREASED BASE FLOW...SO THERE IS LESS OF A
THREAT FOR WIDESPREAD BREAKUP OF THE THICKER ICE. BUT THE
POSSIBILITY OF ICE BREAKUP AND ICE JAM FLOODING CAN NOT BE RULED OUT
FOR RIVERS WITH THINNER ICE COVERAGE. THERE IS ALSO SOME
UNCERTAINTY AS TO THE DEGREE OF SNOW MELT THAT CAN BE EXPECTED AND
THE ASSOCIATED IMPACT ON RIVER LEVELS. CURRENTLY...THE RIVER STAGE
MODELS HAVE BEEN RUN WITH THE PREMISE THAT THE SNOW PACK WILL NOT
COMPLETELY MELT...ESPECIALLY FOR THE NORTHERN PORTIONS OF THE CWA
WHICH HAVE A DEEPER SNOW PACK AND SHOULD BE COLDER FOR A LONGER
PERIOD OF TIME. THERE IS ALSO THE CONSIDERATION THAT THE SNOW PACK
WILL ABSORB SOME OF THE RAINFALL BEFORE IT IS CONVERTED INTO
RUNOFF. SO...ALL THINGS CONSIDERED...THERE WILL BE A SIGNIFICANT
CHANCE FOR RIVER FLOODING WITH MANY RIVERS REACHING OR EXCEEDING
BANK FULL...BUT MAJOR OR RECORD BREAKING RIVER STAGES IS NOT LIKELY.
FOR AREAL FLOODING...THE MAIN CONTRIBUTORS WILL BE THE HEAVY
RAINFALL AND MELTING SNOW. AGAIN...WITH THE FROST DEPTH OF 14
INCHES...IT IS UNLIKELY THAT THERE WILL BE SIGNIFICANT INFILTRATION
INTO THE GROUND AND SNOW MELT AND RAINFALL WILL COMBINE INTO RUNOFF.
HOWEVER...SIMILAR TO THE RIVER ISSUES...IT WILL BE TOUGH FOR ALL OF
THE SNOW PACK TO MELT AND SOME OF THE RAINFALL COULD BECOME TRAPPED
IN THE RESIDUAL SNOW PACK...WHICH WOULD IN TURN LOWER THE RUNOFF.
AT THIS POINT...FEEL THAT AREAL FLOODING WILL BE LIMITED TO FLOODING
OF LOW LYING AREAS...UNDERPASSES AND DITCHES ADJACENT TO ROADS.
ALSO...URBAN AND SUBURBAN AREAS COULD SEE WIDESPREAD AREAS OF
PONDING AND STANDING WATER DUE TO SNOW-CLOGGED STORM DRAINS.
FOR THE HEADLINES...WILL MAINTAIN THE GOING FLOOD WATCH AND MONITOR
CONDITIONS BEFORE EITHER GOING WITH A FLOOD WARNING OR AN URBAN AND
SMALL STREAM FLOOD ADVISORY. AS FOR AREA RIVERS...WILL WAIT UNTIL
THE NEXT MODEL RUNS FROM THE NCRFC BEFORE DECIDING ON HEADLINES FOR
AREA RIVERS. THE CURRENT RIVER FORECASTS DO CONSIDER THE
RAINFALL...BUT HAVE BEEN RUN WITH AN INITIAL CONDITION OF LIMITED
SNOW MELT. CHANGES IN THE INITIAL CONDITIONS FOR SNOW MELT AND QPF
WILL HAVE A SIGNIFICANT IMPACT ON THE RIVER STAGE FORECASTS.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WINTRY MIX POSSIBLE AT PRECIP ONSET.
* RAIN AND THUNDER POSSIBLE THIS MORNING...AND POSSIBLE AGAIN IN
THE AFTERNOON.
* IFR/LIFR CEILINGS.
* STRONG TURNING WINDS.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
COMPLEX FORECAST THIS PERIOD WITH SEVERAL ISSUES POSSIBLE TODAY
THROUGH TONIGHT. SYSTEM TO AFFECT THE REGION STILL APPROACHING AT
THIS TIME BUT REMAINING WEST/SOUTHWEST OF THE TERMINALS. THIS
SHOULD CHANGE OVER THE NEXT SEVERAL HOURS AS BETTER FORCING/PRECIP
SPREAD NORTHEAST ACROSS THE AREA. HAVE PRECIP REACHING THE
TERMINALS BY THE 9Z AND 10Z TIME WITH SOME POTENTIAL FOR A WINTRY
MIX OF SNOW/FREEZING RAIN/SLEET AT THE ONSET. ALTHOUGH WITH
SURFACE TEMPERATURES POSSIBLY HOLDING STEADY OR RISING
SLIGHTLY...THE MAIN THREAT COULD END UP ONLY BEING SNOW OR SLEET.
NONETHELESS...THIS WINTRY MIX SHOULD ONLY BE BRIEF BEFORE IT
BECOMES ALL RAIN SOON THERE AFTER. DID ALSO INCLUDE THE MENTION OF
VCTS IN THE TAFS BY 10Z AS STRONG FORCING AND AN INCREASE IN
INSTABILITY MOVE OVER THE TAFS. CONFIDENCE IS LOW WITH REGARDS TO
THE DURATION...BUT COULD EASILY SEE THUNDER TO BE IN AND AROUND
THE TERMINALS FOR A TWO TO THREE HOUR WINDOW. VFR CEILINGS SHOULD
QUICKLY COME DOWN TO LOW END MVFR AND IFR BY THE 12-13Z TIME
FRAME...AND THEN STAY DOWN WITH A TREND TOWARDS LIFR LIKELY.
PRECIP WILL LIKELY CONTINUE THROUGH THE DAY BUT REMAIN ALL
RAIN...WITH THUNDER POSSIBLE ONCE AGAIN IN THE AFTERNOON.
EXPECT SOUTHEAST WINDS TO BECOME MORE EASTERLY AND POSSIBLY
NORTHEAST LATER THIS MORNING...BEFORE TURNING BACK TOWARDS THE
SOUTHEAST AND SOUTH THIS AFTERNOON. WINDS WILL RAMP UP AND BECOME
STRONG IN THE LATE AFTERNOON AND EARLY EVENING...AS THEY TURN
SOUTHWEST.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE WITH PRECIP SPREADING ACROSS THE TERMINALS...LOW
MEDIUM CONFIDENCE WITH WINTRY MIX AT ONSET.
* MEDIUM CONFIDENCE WITH THUNDER TRENDS.
* HIGH CONFIDENCE WITH CEILING TRENDS.
* MEDIUM CONFIDENCE IN WIND DIRECTION/SPEED.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...CHC SNOW OVERNIGHT.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...CHC SNOW OVERNIGHT.
TUESDAY...VFR.
BMD
&&
.MARINE...
315 PM...LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS
TONIGHT AND DEEPEN AS IT MOVES TO SOUTHERN WISCONSIN THURSDAY
EVENING. THIS LOW WILL THEN CONTINUE TO DEEPEN AS IT REACHES LAKE
SUPERIOR FRIDAY MORNING. SOUTHERLY WINDS WILL TURN SOUTHEAST
TONIGHT AND GRADUALLY INCREASE OVERNIGHT THEN TURN A BIT MORE
EAST/SOUTHEAST THURSDAY AS SPEEDS INCREASE TO 30 KTS MIDDAY. AS
THE LOW APPROACHES...GALES WILL DEVELOP LATE THURSDAY AFTERNOON.
ONCE THE LOW REACHES WISCONSIN...WINDS WILL SHIFT TO THE SOUTHWEST
AND STEADILY INCREASE THROUGH HIGH END GALES AND POTENTIALLY INTO
STORM FORCE. HAVE UPGRADED THE GALE WATCH TO A GALE WARNING AS
CONFIDENCE IS HIGH BUT MAINTAINED THE STORM WATCH FOR NOW. THE LOW
WILL WEAKEN SOME AS IT REACHES JAMES BAY BUT THEN BECOME NEARLY
STATIONARY WHICH WILL ALLOW A FAIRLY STRONG WESTERLY GRADIENT TO
CONTINUE INTO THIS WEEKEND WITH GALES ENDING ACROSS THE NORTH
FRIDAY NIGHT OR SATURDAY MORNING. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLOOD WATCH...ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-
ILZ021-ILZ022-ILZ023-ILZ032-ILZ033-ILZ039...3 AM THURSDAY
TO 6 PM THURSDAY.
HIGH WIND WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022...6
PM THURSDAY TO 6 AM FRIDAY.
HIGH WIND WATCH...ILZ023-ILZ032-ILZ033-ILZ039...6 PM THURSDAY TO
3 AM FRIDAY.
IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...3 AM THURSDAY
TO 6 PM THURSDAY.
HIGH WIND WATCH...INZ001-INZ002...6 PM THURSDAY TO 6 AM FRIDAY.
HIGH WIND WATCH...INZ010-INZ011-INZ019...6 PM THURSDAY TO 3 AM
FRIDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3 PM THURSDAY TO
MIDNIGHT FRIDAY.
STORM WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...MIDNIGHT FRIDAY TO 3
PM FRIDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...3 PM
THURSDAY TO 9 PM THURSDAY.
STORM WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...9 PM
THURSDAY TO 10 AM FRIDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
1103 AM MST THU FEB 20 2014
.UPDATE...
ISSUED AT 1103 AM MST THU FEB 20 2014
BASED ON LATEST MODEL DATA AS WELL AS UPSTREAM OBSERVATIONS IN
WESTERN NEBRASKA...HAVE ISSUED A HIGH WIND WARNING FOR COUNTIES
ALONG/EAST OF A HITCHCOCK TO RAWLINS AND SHERIDAN COUNTY LINE FOR
THIS AFTERNOON.
LATEST HRRR HAS BEGUN TO SHOW AN AREA OF 50 KT WINDS MOVING
ACROSS THE AFOREMENTIONED AREA THIS AFTERNOON. IN ADDITION THE
LATEST RUC HAS ALSO INCREASED THE WIND SPEEDS AT THE TOP OF THE
BOUNDARY LAYER FOR THIS AFTERNOON AS WELL AS EXPANDED THE AREA OF
HIGHEST WIND GUSTS. WIND GUSTS AROUND 60 MPH CAN BE EXPECTED IN
THE NEXT HOUR OR TWO...WITH WIND GUSTS DECLINING DURING THE LATE
AFTERNOON. DUE TO TEMPERATURES BEING ABOVE FREEZING DO NOT
ANTICIPATE MUCH IF ANY BLOWING SNOW.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT.)
ISSUED AT 236 AM MST THU FEB 20 2014
SNOW AND BLOWING SNOW WITH AREAS OF REDUCED VISIBILITY CONTINUE
TO MOVE ACROSS MAINLY THE EASTERN PORTION OF THE FORECAST AREA
THIS MORNING WHILE SNOW APPEARS TO BE ENDING FROM WEST TO EAST
ACROSS FAR EASTERN COLORADO. AM RELUCTANT TO TRIM OFF THE WESTERN
PORTION OF THE WINTER WEATHER ADVISORY TOO EARLY AS WINDS ARE
STILL STRONG ENOUGH TO PRODUCE AREAS OF BLOWING SNOW AND REDUCED
VISIBILITIES.
EXPECT SNOW TO CONTINUE TO MOVE EAST OUT OF THE FORECAST AREA
QUICKLY THIS MORNING AND WILL CONTINUE TO EVALUATE THE POSSIBLE
NEED FOR EXPANSION OF THE ADVISORY IN TIME ACROSS THE EAST THIS
MORNING AND THE POSSIBLE TRIMMING OF THE ADVISORY AREAS ACROSS
THE WEST.
EXPECT THE WINDS TO DECREASE SOMEWHAT THIS MORNING FOLLOWING
SUNRISE AND TO RE-INTENSIFY THROUGH THE MORNING. WILL LEAVE THE
WIND ADVISORY INTACT ACROSS THE ENTIRE FORECAST AREA AS A RESULT.
NORTHWEST WINDS DECREASE RAPIDLY LATE THIS AFTERNOON AND
EVENING AND TURN MORE WESTERLY OVERNIGHT TONIGHT.
WARMER TEMPERATURES ARE EXPECTED ON FRIDAY WITH COOLER
TEMPERATURES SATURDAY WITH A CHANCE OF LIGHT SNOW MOVING INTO THE
AREA FROM THE NORTH ON SATURDAY NIGHT AS THE JET STREAM POSITIONED
ACROSS THE NORTHERN PLAINS BRINGS WEAK IMPULSES EAST OF THE
ROCKIES.
.LONG TERM...(SUNDAY THROUGH NEXT THURSDAY)
ISSUED AT 1206 AM MST THU FEB 20 2014
A LONGWAVE TROUGH WILL BE OVER THE NORTHERN PLAINS AND GREAT LAKES
WITH A SERIES OF SHORTWAVE TROUGHS MOVING THROUGH. THIS WILL
RESULT IN NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES AND
OCCASIONAL CHANCES FOR LIGHT SNOW. THESE SYSTEMS ARE ALL VERY WEAK
AND PRODUCE AN INCH OR LESS OF SNOW. HIGH TEMPERATURES WILL
GENERALLY BE IN THE 30S AND 40S WITH LOWS IN THE TEENS AND 20S. AT
THE VERY END OF THE LONG TERM PERIOD...COLDER AIR MAY BE TAPPED BY
A SOUTHERN STREAM SYSTEM WHICH COULD RESULT IN MUCH BELOW NORMAL
TEMPERATURES FOR THE END OF NEXT WEEK AND BETTER CHANCES OF SNOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1013 AM MST THU FEB 20 2014
VFR CONDITIONS FORECAST FOR THE 12Z TAFS. MAIN ISSUE WILL BE THE
WIND SPEEDS FOR THIS AFTERNOON. EXPECT THE NORTHWEST WINDS TO
INCREASE AS THE MAIN UPPER LEVEL TROUGH APPROACHES THE AREA
THROUGH MID AFTERNOON. KMCK COULD SEE A FEW GUSTS NEAR/AT 50 KTS
DURING THE EARLY TO MID AFTERNOON. OTHERWISE WINDS WILL DECLINE
DURING THE LATE AFTERNOON...BECOMING LIGHT TO BREEZY TONIGHT. DO
NOT ANTICIPATE MUCH BLOWING SNOW SINCE TEMPERATURES HAVE WARMED
ABOVE FREEZING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR
KSZ001-013-014-027>029-041-042.
HIGH WIND WARNING UNTIL 6 PM CST THIS EVENING FOR KSZ002>004-015-
016.
CO...WIND ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ090>092.
NE...WIND ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR NEZ079.
HIGH WIND WARNING UNTIL 6 PM CST THIS EVENING FOR NEZ080-081.
&&
$$
UPDATE...JTL
SHORT TERM...LOCKHART
LONG TERM...024
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
325 AM MST THU FEB 20 2014
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT.)
ISSUED AT 236 AM MST THU FEB 20 2014
SNOW AND BLOWING SNOW WITH AREAS OF REDUCED VISIBILITY CONTINUE
TO MOVE ACROSS MAINLY THE EASTERN PORTION OF THE FORECAST AREA
THIS MORNING WHILE SNOW APPEARS TO BE ENDING FROM WEST TO EAST
ACROSS FAR EASTERN COLORADO. AM RELUCTANT TO TRIM OFF THE WESTERN
PORTION OF THE WINTER WEATHER ADVISORY TOO EARLY AS WINDS ARE
STILL STRONG ENOUGH TO PRODUCE AREAS OF BLOWING SNOW AND REDUCED
VISIBILITIES.
EXPECT SNOW TO CONTINUE TO MOVE EAST OUT OF THE FORECAST AREA
QUICKLY THIS MORNING AND WILL CONTINUE TO EVALUATE THE POSSIBLE
NEED FOR EXPANSION OF THE ADVISORY IN TIME ACROSS THE EAST THIS
MORNING AND THE POSSIBLE TRIMMING OF THE ADVISORY AREAS ACROSS
THE WEST.
EXPECT THE WINDS TO DECREASE SOMEWHAT THIS MORNING FOLLOWING
SUNRISE AND TO RE-INTENSIFY THROUGH THE MORNING. WILL LEAVE THE
WIND ADVISORY INTACT ACROSS THE ENTIRE FORECAST AREA AS A RESULT.
NORTHWEST WINDS DECREASE RAPIDLY LATE THIS AFTERNOON AND
EVENING AND TURN MORE WESTERLY OVERNIGHT TONIGHT.
WARMER TEMPERATURES ARE EXPECTED ON FRIDAY WITH COOLER
TEMPERATURES SATURDAY WITH A CHANCE OF LIGHT SNOW MOVING INTO THE
AREA FROM THE NORTH ON SATURDAY NIGHT AS THE JET STREAM POSITIONED
ACROSS THE NORTHERN PLAINS BRINGS WEAK IMPULSES EAST OF THE
ROCKIES.
.LONG TERM...(SUNDAY THROUGH NEXT THURSDAY)
ISSUED AT 1206 AM MST THU FEB 20 2014
A LONGWAVE TROUGH WILL BE OVER THE NORTHERN PLAINS AND GREAT LAKES
WITH A SERIES OF SHORTWAVE TROUGHS MOVING THROUGH. THIS WILL
RESULT IN NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES AND
OCCASIONAL CHANCES FOR LIGHT SNOW. THESE SYSTEMS ARE ALL VERY WEAK
AND PRODUCE AN INCH OR LESS OF SNOW. HIGH TEMPERATURES WILL
GENERALLY BE IN THE 30S AND 40S WITH LOWS IN THE TEENS AND 20S. AT
THE VERY END OF THE LONG TERM PERIOD...COLDER AIR MAY BE TAPPED BY
A SOUTHERN STREAM SYSTEM WHICH COULD RESULT IN MUCH BELOW NORMAL
TEMPERATURES FOR THE END OF NEXT WEEK AND BETTER CHANCES OF SNOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1040 PM MST WED FEB 19 2014
VFR CONDITIONS FOR KGLD AND KMCK TO BEGIN THE TAF PERIOD WITH
CONDITIONS RAPIDLY DETERIORATING SOON. THE COLD FRONT IS ALREADY
MOVING INTO NORTHWEST KANSAS. NORTH WINDS BEHIND THE FRONT ARE
ALREADY GUSTING TO 40 KTS IN KAKO AND 42 KTS IN KLIC.
KGLD WILL BE GUSTING TO NEAR 42 KTS AROUND 08Z WITH SNOW. ALSO
INCLUDED BLOWING SNOW WITH VISIBILITY AT 1SM. A TEMPO GROUP WAS
INCLUDED FOR WHEN THE HEAVIEST BANDS OF SNOW ARE EXPECTED TO MOVE
ACROSS THE TERMINAL BETWEEN 08Z AND 11Z. VISIBILITY MAY BECOME
LIFR AT 1/2SM. SNOW SHOULD START TO TAPER OFF AROUND 12Z...THIS
TIME IS PUSHED BACK A LITTLE FROM THE 0Z TAFS SINCE RAP MODEL
UPDATES SHOW SNOW LINGERING OVER THE TERMINAL A LITTLE LONGER THAN
PREVIOUSLY THOUGHT. BY LATE MORNING...WIND GUSTS WILL RAMP UP
AGAIN TO NEAR 46 KTS AND THEN COME DOWN BY LATER AFTERNOON WITH
GUSTS DIMINISHING AROUND 0Z.
KMCK SHOULD GUST TO 35 KTS AROUND 07Z AS SHOWERS MOVE INTO THE
TERMINAL. NORTH WINDS WILL INCREASE AROUND 09Z WITH GUSTS NEAR 38
KTS AND LIGHT SNOW BEHIND THE FRONT. VISIBILITY SHOULD BE SIMILAR
TO KGLD WITH BLOWING SNOW SO HAVE IT REDUCED TO 1SM WITH A TEMPO
GROUP FOR LIFR VISIBILITY OF 1/2SM FROM 08Z TO 11Z. ALSO PUSHED
BACK ENDING TIME FOR SNOW TO 13Z. NORTHWEST WINDS WILL INCREASE
ONCE AGAIN IN THE EARLY AFTERNOON TO AROUND 40 KTS AND THEN WILL
DECREASE LATER IN THE AFTERNOON WITH GUSTS DIMINISHING AROUND 0Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 6 AM MST /7 AM CST/ EARLY THIS
MORNING FOR KSZ001-002-013-014-027-041.
WIND ADVISORY FROM 9 AM MST /10 AM CST/ THIS MORNING TO 5 PM MST
/6 PM CST/ THIS AFTERNOON FOR KSZ001>004-013>016-027>029-
041-042.
WINTER WEATHER ADVISORY UNTIL 8 AM CST THIS MORNING FOR KSZ003-
004-015-016-028-029-042.
CO...WINTER WEATHER ADVISORY UNTIL 6 AM MST EARLY THIS MORNING FOR
COZ090>092.
WIND ADVISORY FROM 9 AM THIS MORNING TO 5 PM MST THIS AFTERNOON
FOR COZ090>092.
NE...WINTER WEATHER ADVISORY UNTIL 6 AM MST /7 AM CST/ EARLY THIS
MORNING FOR NEZ079>081.
WIND ADVISORY FROM 9 AM MST /10 AM CST/ THIS MORNING TO 5 PM MST
/6 PM CST/ THIS AFTERNOON FOR NEZ079>081.
&&
$$
SHORT TERM...LOCKHART
LONG TERM...024
AVIATION...ALW/RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1213 AM MST THU FEB 20 2014
.UPDATE...
ISSUED AT 806 PM MST WED FEB 19 2014
MADE SOME MINOR ADJUSTMENTS TO THE FORECAST. MAJORITY OF THE
FORECAST REMAINS UNCHANGED. WINDS ARE BEGINNING TO PICK UP WITH
LOCATIONS ACROSS NORTHEAST COLORADO NOW SUSTAINED AT 25 KTS AND
GUSTING TO 35-37 KTS. WINDS ARE EXPECTED TO CONTINUE INCREASING
THIS EVENING AS THE FRONT BLASTS THROUGH. SOME GUIDANCE CONTINUES
TO SUGGEST THAT WINDS WILL REALLY INCREASE OVER PORTIONS OF
NORTHWEST KANSAS LATE TONIGHT...POSSIBLY EXCEEDING HIGH WIND
WARNING CRITERIA. A SHORTER FUSED HIGH WIND WARNING MAY BE NEEDED
HOWEVER WITH CONFLICTING SIGNALS IN THE MODEL DATA...WAS NOT
CONFIDENT ENOUGH TO MAKE ANY CHANGES TO CURRENT HIGHLIGHTS.
WINDS FOR TOMORROW STILL LOOK ON TRACK. THERE ARE SOME INDICATIONS
THERE COULD BE SOME BLOWING DUST TOMORROW BUT WITH SNOW EXPECTED
TONIGHT AND MELTING TOMORROW...THINK THE GROUND WILL BE TOO WET IN
OUR AREA FOR BLOWING DUST PROBLEMS. THE MOST LIKELY LOCATIONS TO
SEE BLOWING DUST WOULD BE SOUTHWEST NEBRASKA WITH DUST MOVING IN
FROM THE NEBRASKA PANHANDLE. DID NOT PLACE BLOWING DUST INTO THE
GRIDS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 230 PM MST WED FEB 19 2014
LATEST RAP UPPER LEVEL ANALYSIS SHOWS TROUGH CENTERED OVER
SASKATCHEWAN CANADA WITH MEAN AXIS EXTENDING SOUTH OVER MONTANA
AND UTAH. AT THE SURFACE A COLD FRONT CURRENTLY EXTENDS FROM THE
DAKOTAS ACROSS CENTRAL WYOMING AND CENTRAL UTAH. OVER EASTERN
COLORADO A 994MB SURFACE LOW HAS DEVELOPED WITH TIGHT SOUTHERLY
GRADIENT IN PLACE OVER OUR CWA.
REGARDING WINTER WEATHER ADVISORY TONIGHT...
WINTER STORM SHOULD DEVELOPING AS TROUGH MOVES OUT OF NORTHERN
ROCKIES. UPPER LEVEL FORCING SHOULD INCREASE THIS EVENING WITH
COLD FRONT PUSHING SOUTH INTO NW PART OF THE CWA BY ABOUT
03Z...AND THEN ACROSS THE REMAINING CWA THROUGH 09Z. WHILE THERE
ISNT REALLY STRONG CAA BEHIND THIS FRONT...CHANGEOVER SHOULD BE
RELATIVELY QUICK FOR ALL BUT THE FAR SOUTHEAST AS SATURATION TO
WETBULB TEMP WOULD SUPPORT SNOW REACHING SURFACE. BEHIND THIS
FRONT THE COMBINATION OF VERY HIGH 3-6 HOUR PRESSURE RISES AND
STEEP LAPSE RATES WILL HELP MIX A VERY STRONG LLJ TO THE
SURFACE...WITH NEAR WARNING CRITERIA WINDS (60 MPH GUSTS)
POSSIBLE. GUIDANCE HAS GENERALLY TRENDED BACK A LITTLE ON WINDS
ALOFT COMPARED TO A DAY AGO...BUT CONFIDENCE IS IS STILL HIGH FOR
GUSTS AROUND 55 MPH (ISOLATED 60MPH). SHORT RANGE GUIDANCE
(RAP/HRRR) CONTINUES TO INDICATE A VERY INTENSE AND PROGRESSIVE
BAND OF PRECIP MOVING FROM THE NORTHWEST TO THE SOUTHEAST TONIGHT.
THIS GENERALLY MATCH RECENT TRENDS ON GUIDANCE (THOUGH THERE ARE
STILL MINOR DIFFERENCES ON QPF AMOUNTS AND POSITION).
TIMING/POSITION OF DEFORMATION PRECIP BAND WILL DETERMINE LOCATION
OF HIGHER SNOWFALL RATES AND TIMING OF POSSIBLE WHITEOUT
CONDITIONS. SNOW RATES WITH THIS BAND COULD BE QUITE INTENSE AS
MODEL CROSS SECTION CONTINUE TO INDICATE AN UNSTABLE LAYER
ASSOCIATED WITH THE BAND...WHICH COULD LEAD TO SNOWFALL RATES OF
AROUND 2" PER HOUR. DUE TO THE PROGRESSIVE NATURE OF THIS BAND THE
WORST VISIBILITIES ARE NOT EXPECTED TO MEET 3HR REQUIREMENT FOR
BLIZZARD WARNING...AND AMOUNTS WITH BAND SHOULD STILL BE AROUND 3"
MAX. NO CHANGE TO CURRENT WINTER WEATHER ADVISORY AT THIS
TIME...AND WILL ALLOW SUBSEQUENT SHIFT TO MONITOR FOR CHANGES IN
UPSTREAM TRENDS.
THURSDAY...LARGE SCALE SUBSIDENCE WILL SUPPORT RAPIDLY CLEARING
CONDITIONS FROM THE WEST TO THE EAST...WITH ALL PRECIP COMING TO
AN END AROUND SUNRISE. IT STILL LOOKS LIKE THERE WILL BE A BRIEF
REPRIEVE FROM THE STRONGEST WINDS THURSDAY MORNING BEFORE DAYTIME
MIXING BRINGS STRONGER WINDS BACK TO THE SURFACE. WINDS
ALOFT/MIXING HEIGHTS MIGHT SUPPORT NEAR WARNING CRITERIA BEING MET.
IT IS NOT A SLAM DUNK THAT WE WILL REACH WARNING CRITERIA
EVERYWHERE...AND CURRENT WIND ADVISORY THURSDAY COVERS WINDS TO 55
MPH (WHICH GENERALLY MATCHES CURRENT GUIDANCE). NO CHANGE TO WIND
ADVISORY WAS PLANNED WITH THIS UPDATE.
.LONG TERM...(SUNDAY THROUGH NEXT THURSDAY)
ISSUED AT 1206 AM MST THU FEB 20 2014
A LONGWAVE TROUGH WILL BE OVER THE NORTHERN PLAINS AND GREAT LAKES
WITH A SERIES OF SHORTWAVE TROUGHS MOVING THROUGH. THIS WILL
RESULT IN NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES AND
OCCASIONAL CHANCES FOR LIGHT SNOW. THESE SYSTEMS ARE ALL VERY WEAK
AND PRODUCE AN INCH OR LESS OF SNOW. HIGH TEMPERATURES WILL
GENERALLY BE IN THE 30S AND 40S WITH LOWS IN THE TEENS AND 20S. AT
THE VERY END OF THE LONG TERM PERIOD...COLDER AIR MAY BE TAPPED BY
A SOUTHERN STREAM SYSTEM WHICH COULD RESULT IN MUCH BELOW NORMAL
TEMPERATURES FOR THE END OF NEXT WEEK AND BETTER CHANCES OF SNOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1040 PM MST WED FEB 19 2014
VFR CONDITIONS FOR KGLD AND KMCK TO BEGIN THE TAF PERIOD WITH
CONDITIONS RAPIDLY DETERIORATING SOON. THE COLD FRONT IS ALREADY
MOVING INTO NORTHWEST KANSAS. NORTH WINDS BEHIND THE FRONT ARE
ALREADY GUSTING TO 40 KTS IN KAKO AND 42 KTS IN KLIC.
KGLD WILL BE GUSTING TO NEAR 42 KTS AROUND 08Z WITH SNOW. ALSO
INCLUDED BLOWING SNOW WITH VISIBILITY AT 1SM. A TEMPO GROUP WAS
INCLUDED FOR WHEN THE HEAVIEST BANDS OF SNOW ARE EXPECTED TO MOVE
ACROSS THE TERMINAL BETWEEN 08Z AND 11Z. VISIBILITY MAY BECOME
LIFR AT 1/2SM. SNOW SHOULD START TO TAPER OFF AROUND 12Z...THIS
TIME IS PUSHED BACK A LITTLE FROM THE 0Z TAFS SINCE RAP MODEL
UPDATES SHOW SNOW LINGERING OVER THE TERMINAL A LITTLE LONGER THAN
PREVIOUSLY THOUGHT. BY LATE MORNING...WIND GUSTS WILL RAMP UP
AGAIN TO NEAR 46 KTS AND THEN COME DOWN BY LATER AFTERNOON WITH
GUSTS DIMINISHING AROUND 0Z.
KMCK SHOULD GUST TO 35 KTS AROUND 07Z AS SHOWERS MOVE INTO THE
TERMINAL. NORTH WINDS WILL INCREASE AROUND 09Z WITH GUSTS NEAR 38
KTS AND LIGHT SNOW BEHIND THE FRONT. VISIBILITY SHOULD BE SIMILAR
TO KGLD WITH BLOWING SNOW SO HAVE IT REDUCED TO 1SM WITH A TEMPO
GROUP FOR LIFR VISIBILITY OF 1/2SM FROM 08Z TO 11Z. ALSO PUSHED
BACK ENDING TIME FOR SNOW TO 13Z. NORTHWEST WINDS WILL INCREASE
ONCE AGAIN IN THE EARLY AFTERNOON TO AROUND 40 KTS AND THEN WILL
DECREASE LATER IN THE AFTERNOON WITH GUSTS DIMINISHING AROUND 0Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 6 AM MST /7 AM CST/ EARLY THIS
MORNING FOR KSZ001-002-013-014-027-041.
WIND ADVISORY FROM 9 AM MST /10 AM CST/ THIS MORNING TO 5 PM MST
/6 PM CST/ THIS AFTERNOON FOR KSZ001>004-013>016-027>029-
041-042.
WINTER WEATHER ADVISORY UNTIL 8 AM CST THIS MORNING FOR KSZ003-
004-015-016-028-029-042.
CO...WINTER WEATHER ADVISORY UNTIL 6 AM MST EARLY THIS MORNING FOR
COZ090>092.
WIND ADVISORY FROM 9 AM THIS MORNING TO 5 PM MST THIS AFTERNOON
FOR COZ090>092.
NE...WINTER WEATHER ADVISORY UNTIL 6 AM MST /7 AM CST/ EARLY THIS
MORNING FOR NEZ079>081.
WIND ADVISORY FROM 9 AM MST /10 AM CST/ THIS MORNING TO 5 PM MST
/6 PM CST/ THIS AFTERNOON FOR NEZ079>081.
&&
$$
UPDATE...RRH
SHORT TERM...DR
LONG TERM...024
AVIATION...ALW/RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1040 PM MST WED FEB 19 2014
.UPDATE...
ISSUED AT 806 PM MST WED FEB 19 2014
MADE SOME MINOR ADJUSTMENTS TO THE FORECAST. MAJORITY OF THE
FORECAST REMAINS UNCHANGED. WINDS ARE BEGINNING TO PICK UP WITH
LOCATIONS ACROSS NORTHEAST COLORADO NOW SUSTAINED AT 25 KTS AND
GUSTING TO 35-37 KTS. WINDS ARE EXPECTED TO CONTINUE INCREASING
THIS EVENING AS THE FRONT BLASTS THROUGH. SOME GUIDANCE CONTINUES
TO SUGGEST THAT WINDS WILL REALLY INCREASE OVER PORTIONS OF
NORTHWEST KANSAS LATE TONIGHT...POSSIBLY EXCEEDING HIGH WIND
WARNING CRITERIA. A SHORTER FUSED HIGH WIND WARNING MAY BE NEEDED
HOWEVER WITH CONFLICTING SIGNALS IN THE MODEL DATA...WAS NOT
CONFIDENT ENOUGH TO MAKE ANY CHANGES TO CURRENT HIGHLIGHTS.
WINDS FOR TOMORROW STILL LOOK ON TRACK. THERE ARE SOME INDICATIONS
THERE COULD BE SOME BLOWING DUST TOMORROW BUT WITH SNOW EXPECTED
TONIGHT AND MELTING TOMORROW...THINK THE GROUND WILL BE TOO WET IN
OUR AREA FOR BLOWING DUST PROBLEMS. THE MOST LIKELY LOCATIONS TO
SEE BLOWING DUST WOULD BE SOUTHWEST NEBRASKA WITH DUST MOVING IN
FROM THE NEBRASKA PANHANDLE. DID NOT PLACE BLOWING DUST INTO THE
GRIDS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 230 PM MST WED FEB 19 2014
LATEST RAP UPPER LEVEL ANALYSIS SHOWS TROUGH CENTERED OVER
SASKATCHEWAN CANADA WITH MEAN AXIS EXTENDING SOUTH OVER MONTANA
AND UTAH. AT THE SURFACE A COLD FRONT CURRENTLY EXTENDS FROM THE
DAKOTAS ACROSS CENTRAL WYOMING AND CENTRAL UTAH. OVER EASTERN
COLORADO A 994MB SURFACE LOW HAS DEVELOPED WITH TIGHT SOUTHERLY
GRADIENT IN PLACE OVER OUR CWA.
REGARDING WINTER WEATHER ADVISORY TONIGHT...
WINTER STORM SHOULD DEVELOPING AS TROUGH MOVES OUT OF NORTHERN
ROCKIES. UPPER LEVEL FORCING SHOULD INCREASE THIS EVENING WITH
COLD FRONT PUSHING SOUTH INTO NW PART OF THE CWA BY ABOUT
03Z...AND THEN ACROSS THE REMAINING CWA THROUGH 09Z. WHILE THERE
ISNT REALLY STRONG CAA BEHIND THIS FRONT...CHANGEOVER SHOULD BE
RELATIVELY QUICK FOR ALL BUT THE FAR SOUTHEAST AS SATURATION TO
WETBULB TEMP WOULD SUPPORT SNOW REACHING SURFACE. BEHIND THIS
FRONT THE COMBINATION OF VERY HIGH 3-6 HOUR PRESSURE RISES AND
STEEP LAPSE RATES WILL HELP MIX A VERY STRONG LLJ TO THE
SURFACE...WITH NEAR WARNING CRITERIA WINDS (60 MPH GUSTS)
POSSIBLE. GUIDANCE HAS GENERALLY TRENDED BACK A LITTLE ON WINDS
ALOFT COMPARED TO A DAY AGO...BUT CONFIDENCE IS IS STILL HIGH FOR
GUSTS AROUND 55 MPH (ISOLATED 60MPH). SHORT RANGE GUIDANCE
(RAP/HRRR) CONTINUES TO INDICATE A VERY INTENSE AND PROGRESSIVE
BAND OF PRECIP MOVING FROM THE NORTHWEST TO THE SOUTHEAST TONIGHT.
THIS GENERALLY MATCH RECENT TRENDS ON GUIDANCE (THOUGH THERE ARE
STILL MINOR DIFFERENCES ON QPF AMOUNTS AND POSITION).
TIMING/POSITION OF DEFORMATION PRECIP BAND WILL DETERMINE LOCATION
OF HIGHER SNOWFALL RATES AND TIMING OF POSSIBLE WHITEOUT
CONDITIONS. SNOW RATES WITH THIS BAND COULD BE QUITE INTENSE AS
MODEL CROSS SECTION CONTINUE TO INDICATE AN UNSTABLE LAYER
ASSOCIATED WITH THE BAND...WHICH COULD LEAD TO SNOWFALL RATES OF
AROUND 2" PER HOUR. DUE TO THE PROGRESSIVE NATURE OF THIS BAND THE
WORST VISIBILITIES ARE NOT EXPECTED TO MEET 3HR REQUIREMENT FOR
BLIZZARD WARNING...AND AMOUNTS WITH BAND SHOULD STILL BE AROUND 3"
MAX. NO CHANGE TO CURRENT WINTER WEATHER ADVISORY AT THIS
TIME...AND WILL ALLOW SUBSEQUENT SHIFT TO MONITOR FOR CHANGES IN
UPSTREAM TRENDS.
THURSDAY...LARGE SCALE SUBSIDENCE WILL SUPPORT RAPIDLY CLEARING
CONDITIONS FROM THE WEST TO THE EAST...WITH ALL PRECIP COMING TO
AN END AROUND SUNRISE. IT STILL LOOKS LIKE THERE WILL BE A BRIEF
REPRIEVE FROM THE STRONGEST WINDS THURSDAY MORNING BEFORE DAYTIME
MIXING BRINGS STRONGER WINDS BACK TO THE SURFACE. WINDS
ALOFT/MIXING HEIGHTS MIGHT SUPPORT NEAR WARNING CRITERIA BEING MET.
IT IS NOT A SLAM DUNK THAT WE WILL REACH WARNING CRITERIA
EVERYWHERE...AND CURRENT WIND ADVISORY THURSDAY COVERS WINDS TO 55
MPH (WHICH GENERALLY MATCHES CURRENT GUIDANCE). NO CHANGE TO WIND
ADVISORY WAS PLANNED WITH THIS UPDATE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 230 PM MST WED FEB 19 2014
THURSDAY NIGHT-SATURDAY...DRY CONDITIONS EXPECTED WITH VARYING
AMOUNTS OF CLOUDINESS...THICK AT TIMES. BREEZY TO PERHAPS WINDY
CONDITIONS FROM THE NORTHWEST LATE FRIDAY MORNING THROUGH THE
AFTERNOON. HIGHS FRIDAY UPPER 40S FAR NORTHWEST WITH 50S OVER THE
REMAINDER OF THE AREA. FOR SATURDAY COOLER BEHIND FRIDAYS FRONTAL
PASSAGE WITH UPPER 30S NORTHWEST TO MID/UPPER 40S FAR
SOUTH/SOUTHEAST. LOWS THROUGH THE PERIOD GENERALLY IN THE 20S.
SATURDAY NIGHT-WEDNESDAY NIGHT...FORECAST AREA UNDER NORTHWEST FLOW
THROUGH THE PERIOD. WILL HAVE A CHANCE OF SOME LIGHT PRECIPITATION
SATURDAY NIGHT AS A BATCH OF 850-500 MOISTURE MOVES ACROSS AREAS
GENERALLY ALONG AND NORTH OF THE INTERSTATE. SHOULD HAVE A LULL IN
ACTIVITY SUNDAY WITH A SMALL CHANCE OF PRECIP ACROSS THE NORTHEAST
SUNDAY NIGHT INTO MONDAY. COULD SEE ANOTHER ROUND OF LIGHT PRECIP
MONDAY NIGHT A BIT FURTHER WEST THEN PREVIOUS DAYS NEAR PROXIMITY
TO FAVORABLE PORTION OF UPPER JET. TUESDAY AND WEDNESDAY LOOK TO
BE DRY.
HIGH TEMPERATURES A BIT BELOW NORMAL SUNDAY THROUGH TUESDAY WITH
NEAR NORMAL READINGS WEDNESDAY. LOWS THROUGH THE PERIOD PRETTY
CLOSE TO NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1040 PM MST WED FEB 19 2014
VFR CONDITIONS FOR KGLD AND KMCK TO BEGIN THE TAF PERIOD WITH
CONDITIONS RAPIDLY DETERIORATING SOON. THE COLD FRONT IS ALREADY
MOVING INTO NORTHWEST KANSAS. NORTH WINDS BEHIND THE FRONT ARE
ALREADY GUSTING TO 40 KTS IN KAKO AND 42 KTS IN KLIC.
KGLD WILL BE GUSTING TO NEAR 42 KTS AROUND 08Z WITH SNOW. ALSO
INCLUDED BLOWING SNOW WITH VISIBILITY AT 1SM. A TEMPO GROUP WAS
INCLUDED FOR WHEN THE HEAVIEST BANDS OF SNOW ARE EXPECTED TO MOVE
ACROSS THE TERMINAL BETWEEN 08Z AND 11Z. VISIBILITY MAY BECOME
LIFR AT 1/2SM. SNOW SHOULD START TO TAPER OFF AROUND 12Z...THIS
TIME IS PUSHED BACK A LITTLE FROM THE 0Z TAFS SINCE RAP MODEL
UPDATES SHOW SNOW LINGERING OVER THE TERMINAL A LITTLE LONGER THAN
PREVIOUSLY THOUGHT. BY LATE MORNING...WIND GUSTS WILL RAMP UP
AGAIN TO NEAR 46 KTS AND THEN COME DOWN BY LATER AFTERNOON WITH
GUSTS DIMINISHING AROUND 0Z.
KMCK SHOULD GUST TO 35 KTS AROUND 07Z AS SHOWERS MOVE INTO THE
TERMINAL. NORTH WINDS WILL INCREASE AROUND 09Z WITH GUSTS NEAR 38
KTS AND LIGHT SNOW BEHIND THE FRONT. VISIBILITY SHOULD BE SIMILAR
TO KGLD WITH BLOWING SNOW SO HAVE IT REDUCED TO 1SM WITH A TEMPO
GROUP FOR LIFR VISIBILITY OF 1/2SM FROM 08Z TO 11Z. ALSO PUSHED
BACK ENDING TIME FOR SNOW TO 13Z. NORTHWEST WINDS WILL INCREASE
ONCE AGAIN IN THE EARLY AFTERNOON TO AROUND 40 KTS AND THEN WILL
DECREASE LATER IN THE AFTERNOON WITH GUSTS DIMINISHING AROUND 0Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY UNTIL 6 AM MST /7 AM CST/ THURSDAY FOR
KSZ001-002-013-014-027-041.
WIND ADVISORY FROM 9 AM MST /10 AM CST/ TO 5 PM MST /6 PM CST/
THURSDAY FOR KSZ001>004-013>016-027>029-041-042.
WINTER WEATHER ADVISORY UNTIL 8 AM CST THURSDAY FOR KSZ003-004-
015-016-028-029-042.
CO...WINTER WEATHER ADVISORY UNTIL 6 AM MST THURSDAY FOR COZ090>092.
WIND ADVISORY FROM 9 AM TO 5 PM MST THURSDAY FOR COZ090>092.
NE...WINTER WEATHER ADVISORY UNTIL 6 AM MST /7 AM CST/ THURSDAY FOR
NEZ079>081.
WIND ADVISORY FROM 9 AM MST /10 AM CST/ TO 5 PM MST /6 PM CST/
THURSDAY FOR NEZ079>081.
&&
$$
UPDATE...RRH
SHORT TERM...DR
LONG TERM...99
AVIATION...ALW/RRH
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
344 PM CST THU FEB 20 2014
.SHORT TERM...
BIGGEST IMPACT OVER THE FORECAST PERIOD WILL BE OVER THE NEXT 12 TO
15 HOURS. AN UPPER LEVEL TROUGH IS CURRENTLY MOVING ACROSS THE
NORTHERN AND CENTRAL PLAINS OF THE UNITED STATES. THE TIGHTEST CURL
AT THE BASE OF THE LOW IS NOW STARTING TO CURL NORTHEAST TOWARDS THE
UPPER MISSISSIPPI VALLEY. THE ASSOCIATED COLD FRONT IS NOW MOVING
SOUTHEAST OVER EASTERN TEXAS AND JUST ENTERING THE EXTREME
NORTHWESTERN LOUISIANA PARISHES. LATEST RADAR IMAGERY SHOWS A LINE
OF THUNDERSTORMS HAS DEVELOPED ALONG AND AHEAD OF THE LEADING EDGE OF
THE COLD FRONT. MORE LOCALLY...SHOWERS ARE BEGINNING TO INCREASE IN
COVERAGE OVER MOST OF THE CWA. MODELS SHOW THIS TREND CONTINUING
THROUGH THE REST OF THE AFTERNOON. MODEL SOUNDINGS INDICATE THAT
ELEVATED INSTABILITY DOES EXIST OVER THE AREA RIGHT NOW WITH A
SLIGHTLY WARM NOSE JUST ABOVE 700MB. THIS WILL ERODE OVER THE NEXT
FEW HOURS WHICH COULD ALLOW FOR A A FEW STORMS TO INTENSIFY AND
LIKELY START PRODUCING THUNDER. THE NCEP WRF WAS THE MOST AGGRESSIVE
WITH MORE DISCRETE CELLS BEING DEPICTED ON IT. LOOKS TO BE THE
OUTLIAR OF MESO AND MEDIUM RANGE MODELS. THE MAIN PLAYER THIS
EVENING SHOULD BE STORMS ALONG AND JUST AHEAD OF THE COLD FRONT AS
IT MARCHES THROUGH THE FORECAST AREA WHERE DYNAMICAL LIFT WILL BE
THE GREATEST. IT WILL HAVE TO OVERCOME PRETTY SIGNIFICANTLY
DEVELOPING INVERSION WHILE COMING THROUGH. WITH THAT TYPE OF LIFT
AND FAIRLY STRONG WINDS THROUGH THE COLUMN...40 TO 50 KNOTS...THERE
WILL BE A THREAT FOR STRONG TO SEVERE WINDS ALONG THE FRONT. A
TORNADO IS NOT OUT OF THE QUESTION EITHER. THE RISK WILL BE GREATEST
IN SOUTHWEST MISSISSIPPI AND ADJACENT LOUISIANA PARISHES WITH
DECREASING THREAT TO THE SOUTH TOWARDS THE COAST. HRRR LOOKS TO
PRETTY SPOT ON IN TERMS OF INITIALIZATION OF THE CURRENT SQUALL
LINE POSITION AND MOVEMENT. CARRYING THAT OUT IN TIME BRINGS THE
LINE TO NWRN ZONES BY 02Z AND NEW ORLEANS METRO BY 06Z. SHOULD BE
FINISHING UP OVER LAND AREAS WITH STRONGER ACTIVITY BY AROUND 09Z
WITH LINGERING SHOWERS TRAILING BY A FEW HOURS. WOULD NOT BE
SURPRISED TO SEE A SEVERE WATCH PUT OUT FOR MUCH IF NOT ALL OF THE
AREA DURING THE EVENING AND EARLY MORNING HOURS. FOR THE POPS...KEPT
IT SIMPLE AND HAVE A PEAK OF 100 PCT ACROSS THE ENTIRE CWA. THE RAIN
SHOULD THEN TAPER OFF VERY QUICKLY CLOSING IN ON 12Z FRIDAY. BY THIS
POINT...ONLY EXTREME COASTAL LOCATIONS OF MS/LA AND SOUTHWARD SHOULD
HAVE ANY SHOWERS LEFT. THE COLD FRONT WILL CONTINUE SOUTH AND STALL
IN THE CENTRAL GULF OF MEXICO.
.LONG TERM...
ZONAL FLOW WILL RETURN ON SATURDAY AND REMAIN IN PLACE FOR A FEW
DAYS. BUILDING UPPER LEVEL RIDGE WELL TO THE SOUTH OF THE FORECAST
AREA WHICH WILL BRING THE PREVIOUS BOUNDARY BACK NORTH TO THE GULF
COAST. THIS WILL LIKELY BE THE FOCUS FOR SCATTERED SHOWERS AND
POSSIBLY A FEW THUNDERSTORMS BEGINNING ON SUNDAY. HAVE INCREASED
POPS QUITE A BIT ON SUNDAY TO BE MORE IN LINE WITH BOTH GFS AND
ECMWF QPF OUTPUTS. SLIGHTLY BELOW MEX BUT NOT BY MUCH. TEMPERATURES
WILL BE AT OR ABOVE NORMAL THROUGH THE ENTIRE FORECAST PERIOD.
MEFFER
&&
.MARINE...
STILL SEEING SOME LINGERING FOG OVER THE NEARSHORE WATERS NEAR AND
WEST OF THE MISSISSIPPI RIVER. WILL CONTINUE ADVISORY IN THOSE
COASTAL ZONES UNTIL MIDNIGHT. AFTER MIDNIGHT...WIND INCREASE SHOULD
MIX OUT FOG. WILL DROP ADVISORY OVER THE SOUNDS WITH FORECAST
ISSUANCE.
WILL HAVE A PERIOD OF EXERCISE CAUTION WINDS OVER PORTIONS OF THE
EASTERN OPEN WATERS OVERNIGHT...BUT WINDS ARE EXPECTED TO RELAX
SLIGHTLY DURING THE DAY ON THURSDAY. EXPECT SMALL CRAFT ADVISORY TO
BE NECESSARY ON FRIDAY BEHIND THE COLD FRONT...WITH WINDS EASING BY
EVENING. QUIET CONDITIONS EXPECTED BEYOND FRIDAY FOR THE WEEKEND. 35
&&
.AVIATION...
ONSHORE FLOW WELL ESTABLISHED TODAY WITH MVFR TO VFR CEILINGS
COMMON. GENERALLY SEEING LOWER DECK IN FL015-025 RANGE AND SECOND
DECK IN FL035-050 LAYER. THESE WILL OCCASIONALLY SCATTER OUT AND
THEN FILL BACK IN. HAVE MADE LITTLE CHANGE IN TIMING OF LINE OF
CONVECTION THAT IS JUST NOW BEGINNING TO DEVELOP NORTHWEST OF
SHREVEPORT...18Z TAF PACKAGE TIMING STILL REASONABLE. STILL
POTENTIAL FOR SEVERE WIND GUSTS WITH THIS LINE AS WELL AS TEMPORARY
IFR CEILINGS/VISIBILITIES. THE THUNDERSTORMS WILL BE NEAR OR JUST
AHEAD OF COLD FRONT WITH A QUICK SHIFT TO NORTHWEST WINDS BEHIND
FRONT. ANTICIPATE SEVERAL HOURS OF GUSTY WINDS BEHIND THE
FRONT...POSSIBLY GUSTING ABOVE 30 KNOTS DOWNWIND OF LAKE
PONTCHARTRAIN AT KMSY AND KNEW. CLOUDS EXPECTED TO CLEAR OUT RAPIDLY
BEHIND THE FRONT FRIDAY MORNING. 35
&&
.DECISION SUPPORT...
DSS CODE...BLUE WITH POSSIBLE UPGRADE THIS EVENING
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT
MONITORING TSTM THREAT FOR THIS EVE/TONIGHT.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 45 66 37 70 / 100 10 0 0
BTR 47 67 42 73 / 100 10 0 0
ASD 51 67 38 69 / 100 10 0 0
MSY 53 66 47 68 / 100 10 0 0
GPT 51 66 40 66 / 100 10 0 0
PQL 50 68 37 69 / 100 20 0 0
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY FROM MIDNIGHT FRIDAY TO NOON FRIDAY FOR THE
FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL
WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM
PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL
WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20
NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA
RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON
TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM
STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST
PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO
60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE
BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND
MISSISSIPPI SOUND.
MS...NONE.
GM...SMALL CRAFT ADVISORY FROM MIDNIGHT FRIDAY TO NOON FRIDAY FOR THE
FOLLOWING ZONES: BRETON SOUND...CHANDELEUR SOUND...COASTAL
WATERS FROM BOOTHVILLE LA TO THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER OUT 20 NM...COASTAL WATERS FROM
PASCAGOULA MS TO STAKE ISLAND LA FROM 20 TO 60 NM...COASTAL
WATERS FROM PASCAGOULA MS TO STAKE ISLAND LA OUT 20
NM...COASTAL WATERS FROM PORT FOURCHON TO LOWER ATCHAFALAYA
RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM PORT FOURCHON
TO LOWER ATCHAFALAYA RIVER OUT 20 NM...COASTAL WATERS FROM
STAKE ISLAND LA TO THE SOUTHWEST PASS OF THE MISSISSIPPI
RIVER FROM 20 TO 60 NM...COASTAL WATERS FROM THE SOUTHWEST
PASS OF THE MISSISSIPPI RIVER TO PORT FOURCHON FROM 20 TO
60 NM...COASTAL WATERS FROM THE SOUTHWEST PASS OF THE
MISSISSIPPI RIVER TO PORT FOURCHON OUT 20 NM...LAKE
BORGNE...LAKE PONTCHARTRAIN AND LAKE MAUREPAS...AND
MISSISSIPPI SOUND.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
427 PM EST THU FEB 20 2014
.SYNOPSIS...
A STALLED FRONTAL BOUNDARY ACROSS NORTH CAROLINA THIS EVENING WILL
LIFT NORTH AS A WARM FRONT LATER TONIGHT. A COLD FRONT CROSSES THE
MID ATLANTIC REGION ON FRIDAY. HIGH PRESSURE AND DRIER CONDITIONS
RETURN TO THE REGION DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
VARIABLE CLOUDINESS TODAY WILL CONTINUE THROUGH TONIGHT. PLENTY OF
INSTABILITY IN THE FORM OF ACCAS CLOUDS (VIA VISIBLE SATELLITE
IMAGERY) CAN BE SEEN ALONG AND SOUTH OF A WARM FRONT STALLED
ACROSS NORTH CAROLINA LATE THIS AFTN. WILL NEED TO MONITOR THE
LOCATION/PROGRESS OF THE ACCAS INTO FAR WRN PORTIONS OF THE FA
LATE TONIGHT AS THE WARM FRONT LIFTS THROUGH THE REGION. HAVE
LIMITED POPS TO 10 PERCENT FOR THE PIEDMONT OVERNIGHT. GUSTY SOUTH
WINDS WILL DEVELOP AFTER MIDNIGHT BEHIND THE WARM FRONT AND
TEMPS/DEWPOINTS WILL START TO RISE. TEMPS SHOULD BOTTOM OUT
SHORTLY AFTER MIDNIGHT WITH LOWS IN THE LOWER 50S NORTH TO AROUND
60 DEGREES SOUTH. BY DAYBREAK...TEMPS SHOULD BE IN THE MID 50S
NORTH TO LOWER 60S SOUTH.
MEANWHILE...A STRONG LOW PRESSURE SYSTEM IN THE MIDWEST WILL TRACK
ALMOST DUE NORTH INTO THE GREAT LAKES REGION TONIGHT. THIS WILL
SHIFT THE UPPER LEVEL JET DYNAMICS INTO A MORE NORTH-TO-SOUTH
ORIENTATION AND WILL LIKELY DELAY THE ONSET OF PRECIPITATION BY A
FEW HOURS. THEREFORE PRECIP IS NOT EXPECTED TO MOVE INTO FAR WRN
PORTIONS OF THE FA UNTIL JUST AFTER DAYBREAK...HOWEVER ISENTROPIC
LIFT ADVECTING MOISTURE INTO THE PIEDMONT/CTRL VA MAY BE ENOUGH TO
SUPPORT SHOWERS JUST PRIOR TO SUNRISE. DUE TO SLOWER TIMING...HAVE
CUT BACK ON PRECIP CHANCES IN WRN AREAS TO 30 PERCENT PRE-DAWN TO
60-70 PERCENT JUST AFTER DAYBREAK.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
THE APPROACHING COLD FRONT WILL MOVE INTO THE WRN HALF OF THE CWA BY
MID-LATE MORNING AND THEN CROSS THE ERN HALF DURING THE AFTN...
PUSHING OFFSHORE DURING THE EVENING. THE BULK OF RAINFALL WILL
OCCUR RIGHT ALONG AND BEHIND THE FRONT WHICH WILL THEN CONTINUE
INTO FRIDAY EVENING BEFORE TAPERING OFF FROM WEST TO EAST. THERE
ARE SEVERAL PARAMETERS THAT WILL SUPPORT THUNDERSTORM DEVELOPMENT
ON FRIDAY DESPITE THE BEST DYNAMICS LYING WELL TO THE NORTH. THE
AREA WILL BE LOCATED ALONG THE RIGHT ENTRANCE REGION OF THE UPPER
LEVEL JET PLUS THERE IS DECENT MID LEVEL INSTABILITY (850-500 MB)
PRESENT...BOTH OF WHICH SUPPORT ENHANCED LIFT. 0-1 KM WIND SHEAR
PROFILES VEER FROM SOUTH TO SOUTHWEST AND THEN BECOME UNIDIRECTIONAL
FROM THE SOUTHWEST ABOVE 1 KM. THIS TYPE OF SHEAR PROFILE SUPPORTS
THUNDERSTORM LINE SEGMENTS AND ULTIMATELY A THREAT FOR GUSTY
THUNDERSTORM WINDS. AT THE SFC...SOUTH WINDS OF 15-20 MPH WILL
INCREASE IN STRENGTH AND BECOME GUSTY JUST AHEAD OF THE COLD
FRONTAL PASSAGE DURING THE LATE MORNING/EARLY AFTERNOON HOURS.
NON-THUNDERSTORM WIND GUSTS SHOULD AVERAGE AROUND 30-35 MPH.
MEANWHILE...THUNDERSTORM WIND GUSTS SHOULD RANGE FROM 30-50 MPH
WITH LOCALLY HIGHER GUSTS POSSIBLE. PWATS INCREASE TO 1.00-1.50
INCHES DURING THE DAY. THIS WILL CONTRIBUTE TO THE POTENTIAL FOR
MODERATE TO HEAVY RAINFALL AT TIMES...ESPECIALLY UNDER STRONGER
STORM CORES. STORM TOTAL QPF SHOULD AVERAGE 0.50 INCHES WITH
LOCALLY HIGHER AMOUNTS POSSIBLE DUE TO CONVECTION. TEMPERATURES
WILL BE TRICKY AND HIGHLY DEPENDENT ON THE FROPA TIMING. TRENDING
TWD A LATER ARRIVAL OF THE FRONT MEANS THAT TEMPS SHOULD TAKE ON
MORE OF A NORMAL DIURNAL TREND...BUT MAY PEAK BY LATE MORNING FAR
WRN AREAS AND BY EARLY AFTN FOR THE ERN HALF OF THE FA. HIGH TEMPS
RANGE FROM THE LOWER 60S NW/N TO UPPER 60S SE (AROUND 70 COASTAL
NE NC).
PRECIP COMES TO AN END FRIDAY EVENING AS THE FRONT PUSHES WELL
OFFSHORE. DECENT CLEARING AND WINDS BECOMING LIGHT WILL ALLOW TEMPS
TO DROP INTO THE LOW-MID 30S NW TO UPPER 30S SE BY SATURDAY MORNING.
HIGH PRESSURE AND DRIER CONDITIONS WILL PREVAIL SATURDAY INTO
SUNDAY. HIGHS WILL GENERALLY BE IN THE 60S SAT/SUN WITH LOWS SUNDAY
MORNING IN THE MID-UPPER 30S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
HIGH LATITUDES CONTINUE TO BE DOMINATED BY A DYNAMIC/HIGHLY
AMPLIFIED PATTERN THROUGH THE EXTENDED. QUASI-ZONAL FLOW OVER THE
CONUS TO BEGIN THE EXTENDED WILL AMPLIFY EARLY NEXT WEEK...
CHARACTERIZED BY A MEAN RIDGE IN THE WEST AND DEEPENING TROUGH IN
THE EAST. SHORTWAVE ENERGY IN THE NRN STREAM...ROUNDING THE BASE
OF A STRONG -2 TO -3 STD DEV UPPER LOW...WILL IMPACT THE NE INTO
THE MID- ATLANTIC THROUGH THE EXTENDED. HOWEVER...THESE WAVES ARE
TYPICALLY DIFFICULT TO TIME AND THERE REMAINS LARGE SPREADS IN
ENSEMBLE GUIDANCE AND DETERMINISTIC RUNS. THE FIRST WAVE WILL PUSH
A CLIPPER FRONT THROUGH THE REGION SUN NIGHT-MON MORNING. FRONTAL
PASSAGE ANTICIPATED TO BE DRY AS PROFILES SHOW LIMITED NRN STREAM
MOISTURE AND WLY FLOW. HIGH PRESSURE BUILDS IN BEHIND THE DEPARTING
FRONT MON. SPATIAL AND TIMING DIFFERENCES WITH THE SFC HIGH RESULT
IN A TRICKY TEMP FORECAST MON AS LOW LEVEL THICKNESSES BTWN
GFS/GEFS AND ECMWF ARE NEARLY 30 M. THE RESULT WOULD BE HIGHS IN
THE MID 40S OR MID 50S. PREFERRED AN ENSEMBLE/WPC APPROACH TO
SMOOTH OUT THE DIFFERENCES FOR THE TIME BEING WITH TEMPS SLIGHTLY
BELOW SEASONAL NORMS (HIGHS MID 40S NORTH TO LOW 50S SOUTH). THE
NEXT SHORTWAVE WILL TRAVERSE THE NE STATES TUES AS A WEAK SRN
STREAM WAVE DEVELOPS A LOW ALONG THE STALLED COLD FRONT OVER THE
GULF STATES. MODELS KEEP ANY MEASURABLE PRECIP SOUTH OF THE
REGION...WHICH MATCHES WELL WITH THE DEEPENING TROUGH OVER THE ERN
CONUS. WHILE CONDITIONS WILL REMAIN DRY TUES...DO ANTICIPATE
INCREASING CLOUDS THROUGH THE DAY. MORE POTENT SHORTWAVE DIGGING
OVER THE GREAT LAKES LATE TUES-TUES NIGHT AND INCREASING WINDS
ALOFT WILL DEVELOP A STRONGER WAVE ALONG THE FRONT OFF THE SE
COAST TUES NIGHT. LOW WILL LIFT OFF THE MID-ATLANTIC COAST WEDS
MORNING. HAVE OPTED TO MAINTAIN SLIGHT CHANCE POPS INLAND DUE TO
UNCERTAINTY (WHILE THE TREND MAY BE TO TAKE THEM OUT) BUT HAVE
INCREASED THE COAST TO LOW END CHANCE POPS TUES NIGHT-WEDS
MORNING. TEMPS MAY BE COLD ENOUGH FOR FROZEN PRECIP BUT CAA LOOKS
MARGINAL DUE TO NO STRONG HIGH PRESSURE TO THE NORTHWEST...SO HAVE
OPTED FOR RAIN OR SNOW WORDING AS FAR SOUTH AS CENTRAL VA. HIGH
PRESSURE BUILDS IN FROM THE WEST WED AFTERNOON THROUGH THE END OF
THE EXTENDED PERIOD...RESULTING IN MOSTLY CLEAR SKIES AND DRY/COOL
CONDITIONS.
&&
.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
FRONTAL BOUNDARY WILL SLOWLY LIFT NORTH THROUGH THE AREA TONIGHT.
THE FRONT ALOFT IS GENERATING SOME CLOUDS THIS AFTERNOON AND
EVENING...ALL WILL BE VFR CIGS. NO PRECIPITATION IS EXPECTED. LATER
TONIGHT ALL MODELS SHOW MOISTURE ADVECTING NORTH OFF THE GULF
STREAM AND ACROSS THE AREA AT THE LOW LEVELS AFTER 06Z TONIGHT.
STILL NOT COMPLETELY CONVINCED ON THIS AS THE SREF ONLY DEPICTS IT
FOR KRIC AND KSBY. HOWEVER ALL BUFKIT SOUNDINGS FROM THE GFS NAM
AND RAP SHOW IT AT ALL THE SITES. SO DEVELOPED IFR CIGS AFTER 06Z
TONIGHT. MODELS ARE SLOW TO BREAK THESE CLOUDS FRIDAY MORNING SO
ONLY SLOWLY RAISE CIGS TO MVFR DURING THE MORNING. COLD FRONT WILL
BE APPROACHING KRIC BY THE END OF THE PERIOD AND BRING SHOWERS
INTO RIC AFTER 15Z AND KPHF BY 17Z. THUNDERSTORMS ARE EXPECTED TO
DEVELOP ALONG THE LEADING EDGE OF THE FRONT AS IT MOVES THROUGH
THE AREA. EXPECT CIGS AND POTENTIALLY VSBY TO BECOME IFR WITH THESE
SHOWERS DUE TO MODERATE TO HEAVY RAINFALL COMBINED WITH GUSTY
SOUTHWEST WINDS. ALL PRECIPITATION WILL EXIT THE COAST BY FRIDAY
EVENING WITH SKIES CLEARING BEHIND IT...BRINGING VFR CONDITIONS TO
THE REGION ONCE AGAIN. VFR CONDITIONS ARE EXPECT THROUGH THE
WEEKEND.
&&
.MARINE...
HIGH PRESSURE HAS PUSHED OFFSHORE THIS AFTERNOON AS A WARM FRONT
LIFTS NWD FROM NC. BENIGN CONDITIONS (WINDS GENERALLY AOB 5-10 KT)
OVER THE WATERS WILL QUICKLY GIVE WAY TO INCREASING SLY WINDS THIS
EVENING THROUGH TONIGHT AS THE WARM FRONT LIFTS OVER OF THE WATERS.
GRADIENT WILL STRENGTHEN OVER THE WATERS IN ADVANCE OF A STRONG COLD
FRONT WITH SLY WINDS REACHING SCA SPEEDS AROUND MIDNIGHT TONIGHT.
WHILE A STRONG LOW LEVEL INVERSION WILL PREVENT THE STRONGEST WINDS
ALOFT FROM REACHING THE WATER...PRESSURE FALLS AND THE TIGHT
GRADIENT WILL PRODUCE WINDS OF 15-25 KT OVER THE BAY AND 20-30 KT
OVER THE COASTAL WATERS. STRONG WINDS WILL CONTINUE INTO FRI BEFORE
THE COLD FRONT CROSSES THE WATERS FRIDAY AFTERNOON. SHOWERS AND
THUNDERSTORMS WILL ALSO ACCOMPANY THE FRONT...WHICH MAY PRODUCE
STRONGER WIND GUSTS WITH CONVECTION. AS THE FRONT CROSSES THE WATERS
AND WINDS BACK TO THE NW...ANTICIPATE A QUICK SURGE POST FRONTAL
BEFORE WINDS DIMINISH FRIDAY NIGHT AS HIGH PRESSURE BUILDS IN FROM
THE SOUTHWEST. WAVES MAY BRIEFLY INCREASE TO 4 FT AROUND MIDDAY
FRIDAY ON THE BAY. MEANWHILE...SEAS WILL BUILD TO 5-6 FT ON THE
SOUTHERN COASTAL WATERS...AND 6-8 FT ON THE NORTHERN COASTAL WATERS.
HEADLINES ARE IN EFFECT FOR ALL WATERS FROM AFTER MIDNIGHT TONIGHT
THROUGH 4PM FRIDAY. RIVERS DROP OFF FIRST BEFORE THE BAY AT 6PM AND
THE NRN COASTAL WATERS AT MIDNIGHT FRI NIGHT. HIGH PRESSURE REMAINS
OVER THE WATERS THROUGH THE WEEKEND BEFORE A CLIPPER FRONT CROSSES
THE WATERS SUNDAY NIGHT-MONDAY MORNING.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 4 PM EST FRIDAY FOR
ANZ635>638.
SMALL CRAFT ADVISORY FROM 1 AM TO 6 PM EST FRIDAY FOR
ANZ630>634.
SMALL CRAFT ADVISORY FROM 1 AM FRIDAY TO MIDNIGHT EST FRIDAY
NIGHT FOR ANZ650-652-654.
SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST FRIDAY FOR ANZ656-
658.
&&
$$
SYNOPSIS...BMD
NEAR TERM...BMD
SHORT TERM...BMD
LONG TERM...SAM
AVIATION...JDM/JAB
MARINE...SAM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1244 PM EST THU FEB 20 2014
.SYNOPSIS...
A STALLED FRONTAL BOUNDARY ACROSS NORTH CAROLINA TODAY...WILL
MOVE BACK NORTH AS A WARM FRONT TONIGHT. A COLD FRONT MOVES
ACROSS THE AREA FRIDAY. HIGH PRESSURE RETURNS FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FRONTAL BOUNDARY THAT DROPPED THROUGH THE FA LAST NIGHT PROGGED
TO STALL ACROSS NC TODAY AS WEAK HIGH PRESSURE DRIFTS EAST THEN
OFF THE NORTHERN MID ATLANTIC COAST THIS AFTERNOON. TSCTNS SHOW
PLENTY OF MOISTURE AT VARIOUS LEVELS DUE THE MID LEVEL MOISTURE
SEEN CAUGHT UP IN THE UPR LEVEL FLOW COMBINED WITH THE LOW LEVEL
MOISTURE DUE TO THE LIGHT E-SE FLOW AROUND THE DEPARTING HIGH.
UPSHOT WILL BE SKIES BECMG M CLDY TO CLDY (CIGS BTWN 2-5K FT) AS
THE DAY PROGRESSES.
SREF/NAM JUST SHOWING JUST CLOUDS BUT GFS TRIES TO DVLP SOME LGT
SHWRS/SPRINKLES ACROSS THE PIEDMONT (WEST OF I95) AFTER 18Z AS THE
FRONTAL BOUNDARY BEGINS TO RETURN NORTH AS A WARM FRONT. ALTHOUGH
A SPRINKLE NOT OUT OF THE QUESTION W OF I95...CHCS ARE RATHER LOW
SO KEPT A DRY FCST TODAY BUT INDICATED A 14 POP W OF I95. COOLER
DUE TO CLOUDS AND ONSHORE FLOW. HIGHS 55-60 NORTH...60-65 SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A MORE AMPLIFIED TROUGH APPROACHES THE REGION TONIGHT. THE PRIMARY
MID-LEVEL LOW LIFTS NNE ACROSS THE GREAT LAKES WHICH ALLOWS THE
WARM FRONT TO LIFT NORTH ACROSS THE AREA...WITH THE MODELS NOW
SHOWING THE TRAILING COLD FRONT IVOF THE I81 CORRIDOR BY 12Z FRI.
A SUSTAINED SOUTH WIND KEEPS MINS FROM DROPPING MUCH...WITH READINGS
RISING OVERNIGHT AS SRLY FLOW INCREASES DUE TO THE TIGHTENING PRS
GRADIENT. LOWS FROM U40S/ARND 50 F NORTH TO THE M-U50S SOUTH AROUND
MIDNIGHT RISING INTO THE M50S-L60S BY 12Z FRI. SCT SHWRS PROGGED
TO DVLP ACROSS THE WRN PIEDMONT AFTER 09Z.
ALL MODELS HAVE THE COLD FRONT CROSSING THE FA FRI. SPC HAS CWA IN
SLIGHT RISK FOR SEVERE (PRIMARILY WINDS). A FEW MAIN THINGS EXIST
THAT WOULD SUGGEST ONLY A MINIMAL CHANCE FOR SEVERE WX: 1) TIMING IS
EARLY IN THE PERIOD...WITH LITTLE CHANCE FOR DAYTIME HEATING EXCEPT
OVER THE FAR SE ZONES. 2) THE MID LVL TROUGH / SHORTWAVE BECOMES
NEGATIVELY TILTED WELL OFF TO OUR NW TONIGHT/FRI...SUGGESTING THAT
THE BEST ENERGY FOR STRONG STORMS WOULD REMAIN WEST OF THE MTNS
WHERE THE FRONTOGENETIC FIELDS WEAKEN...AND THE BOUNDARY TAKES ON
MORE OF AN ANAFRONTAL STRUCTURE. CATEGORICAL POPS (90%) ALL AREAS...
MAINLY IN THE LATE MORNING TO EARLY AFTN TIMEFRAME. KEPT A PERIOD
OF SLIGHT CHC TSTMS IN THE NW...AND CHC TSTMS SE...BUT THINK THAT
STORMS WILL GENLY BE SUB-SEVERE IN NATURE (WITH BEST CHC FOR SEVERE
BEING OVER FAR SE VA/NE NC). WILL MENTION THIS IN HWO. HIGH TMPS
WILL DEPEND ON ACTUAL TIMING OF FROPA & PCPN. EXPECT MORNING HIGHS
IN THE 60S... NR 70 SERN AREAS WITH STEADLY OR FALLING READINGS IN
THE AFTERNOON. TSCTNS SHOW COLUMN DRYING ACROSS WESTERN HALF OF FA
AFTER 18Z LEADING TO SOME PARTIAL SUNSHINE. TOTAL QPF ONE THIRD TO
ONE HALF INCH.
LINGERING SHOWERS ACROSS THE SERN COASTAL AREAS QUICKLY END ERLY FRI
EVENING. OTW...DRY WX FRI NIGHT/SAT AND STAYING FAIRLY MILD AS LOW
LEVEL FLOW IS WSW SO COLDER AIR REMAINS OVER THE MIDWEST/NE STATES.
LOWS FRI NIGHT IN THE 30S...PT TO MSTLY SSAT. HIGHS 60-65.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MEDIUM RANGE GUIDANCE GENERALLY IN GOOD AGREEMENT WITH UPPER AIR
PATTERN THROUGH THE EXTENDED PERIOD AS THE NRN STREAM REMAINS
ACTIVE. SFC HIGH PRESSURE WILL SLIDE OFFSHORE SAT NIGHT-SUN MORNING
AS A CLIPPER FRONT APPROACHES FROM THE WEST. ECMWF IS MORE
AMPLIFIED/STRONGER WITH THE SHORTWAVE ENERGY OVER THE GREAT LAKES
REGION SUN...WHILE ITS GFS COUNTERPART REMAINS MAINLY ZONAL OVER THE
MID-ATLANTIC. AS A RESULT...THE GFS PUSHES THE FRONT THROUGH THE
REGION QUICKER THAN THE ECMWF. THIS WILL MOSTLY IMPACT HIGH TEMPS
SUN AS THE FRONT REMAINS DRY (BOTH GLOBAL MODELS KEEP PRECIP
CONFINED WELL SOUTH OF THE LOCAL AREA). HAVE TRENDED TOWARD THE
WARMER ECMWF WITH HIGHS IN THE LOW-MID 60S UNDER PARTLY CLOUDY SKIES
(COOLER ALONG THE COAST AND ERN SHORE). THEREAFTER...BROAD CYCLONIC
FLOW WILL REMAIN OVER THE ERN CONUS THROUGH THE EXTENDED PERIOD AS
ADDITIONAL SHORTWAVE ENERGY DIGS OVER THE OH VALLEY.
HOWEVER...SPATIAL AND TIMING DIFFERENCES WRT TO SHORTWAVE ENERGY
WILL IMPACT HOW DEEP THE TROUGH BECOMES AND HOW FAR SOUTH THE
ASSOCIATED COLD AIR REACHES. HAVE TRENDED TEMPS BELOW SEASONABLE
NORMS BEGINNING MONDAY. BEST CHANCE FOR PRECIP DURING THE EXTENDED
LOOKS TO BE TUES-WEDS AS A SFC LOW DEVELOPS ALONG A COLD FRONT OVER
THE GULF STATES/NRN GULF TUES NIGHT. SFC LOW WILL LIFT ALONG THE SE
COAST AND OFF THE MID-ATLANTIC COAST WEDS MORNING...PULLING AWAY
FROM THE REGION WEDS AFTERNOON. WILL MAINTAIN SLIGHT CHANCE POPS DUE
TO MODEL UNCERTAINTY AND LIMITED MOISTURE AND TREND TEMPS COOLER.
COULD ALSO SEE FROZEN PRECIP TUES NIGHT-WEDS MORNING...MAINLY OVER
THE NRN LOCAL AREA.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
FRONTAL BOUNDARY WILL SLOWLY NORTH NORTH THROUGH THE AREA TONIGHT.
THE FRONT ALOFT IS GENERATING SOME CLOUDS THIS AFTERNOON AND
EVENING ALL WILL BE VFR CIGS. NO PRECIPITATION IS EXPECTED. LATER
TONIGHT ALL MODELS SHOW MOISTURE ADVECTING NORTH OFF THE GULF
STREAM AND ACROSS THE AREA AT THE LOW LEVELS. MODELS ALL DEVELOP
IFR STRATUS CLOUDS AFTER 06Z TONIGHT. STILL NOT COMPLETELY
CONVINCED ON THIS AS THE SREF ONLY DEPICTS IT FOR KRIC AND KSBY.
HOWEVER ALL BUFKIT SOUNDINGS FROM THE GFS NAM AND RAP SHOW IT AT
ALL THE SITES. SO DEVELOPED IFR CIGS AFTER 06Z TONIGHT. MODELS ARE
SLOW TO BREAK THESE CLOUDS IN THE MORNING ON FRIDAY SO ONLY SLOWLY
RAISE CIGS TO MVFR DURING THE MORNING. COLD FRONT WILL BE
APPROACHING KRIC BY THE END OF THE PERIOD AND BRING SHOWERS INTO
RIC AFTER 15Z AND KPHF BY 17Z. THERE COULD BE ISOLATED
THUNDERSTORMS ACCOMPANYING THE FRONT AS IT MOVES THROUGH. EXPECT
CIGS AND POTENTIALLY VSBY TO BECOME IFR WITH THESE SHOWERS. ALL
PRECIPITATION WILL EXIT THE COAST BY FRIDAY EVENING WITH SKIES
CLEARING BEHIND IT GIVING VFR CONDITIONS AGAIN.
VFR CONDITIONS ARE EXPECT THROUGH THE WEEKEND.
&&
.MARINE...
HIGH PRESSURE CENTERED OVER THE WATERS THIS MORNING WILL MOVE
EASTWARD BY LATER TODAY AS A WARM FRONT LIFTS NWD OVER THE REGION.
LIGHT NE WINDS WILL GRADUALLY VEER AROUND TO THE SOUTHEAST BY LATE
TODAY. WINDS BECOME SOUTHERLY AND INCREASE TONIGHT IN ADVANCE OF A
COLD FRONT THAT WILL CROSS THE WATERS FRIDAY AFTERNOON. SHOWERS AND
THUNDERSTORMS WILL ACCOMPANY THE FRONTAL PASSAGE. SCA`S HAVE BEEN
HOISTED FOR FRIDAY AS SLY WINDS OF 15-20 KT WITH GUSTS TO 25 KT ON
THE BAY/ERN VA RIVERS/CURRITUCK SOUND AND 20-25 KT WITH GUSTS TO 30
KT FOR THE COASTAL WATERS APPEAR LIKELY. WAVES MAY BRIEFLY INCREASE
TO 4 FT AROUND MIDDAY FRIDAY ON THE BAY. MEANWHILE...SEAS WILL BUILD
TO 5-6 FT ON THE SOUTHERN COASTAL WATERS...AND 6-8 FT ON THE NORTHERN
COASTAL WATERS. WINDS/WAVES/SEAS WILL DIMINISH/SUBSIDE LATE FRIDAY
IN THE WAKE OF THE FRONT. HIGH PRESSURE RETURNS THROUGH THE WEEKEND.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 3 AM TO 1 PM EST FRIDAY FOR
ANZ635>638.
SMALL CRAFT ADVISORY FROM 3 AM TO 4 PM EST FRIDAY FOR
ANZ630>634.
SMALL CRAFT ADVISORY FROM 3 AM FRIDAY TO MIDNIGHT EST FRIDAY
NIGHT FOR ANZ650-652-654.
SMALL CRAFT ADVISORY FROM 3 AM TO 7 PM EST FRIDAY FOR ANZ656-
658.
&&
$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...LKB/MPR
LONG TERM...SAM
AVIATION...JDM/JAB
MARINE...JDM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1229 AM EST THU FEB 20 2014
.UPDATE...
ISSUED AT 942 PM EST WED FEB 19 2014
ADJUSTED MIN TEMPS UP A COUPLE OF DEGREES...MAINLY OVER THE W AND
NEAR THE WI BORDER WHERE HI CLDS HAVE ARRIVED BEFORE SFC WINDS COULD
DECOUPLE. BUT CONCERN THAT HI CLDS MIGHT THIN LATER TNGT WITH
RELATIVELY LGT WINDS/OVERALL DRY AIRMASS IN PLACE LIMITED THE
ADJUSTMENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 518 PM EST WED FEB 19 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW TROF MOVING ACROSS THE
ROCKIES WITH 2 MAIN SHORTWAVES OF INTEREST THAT WILL CONSPIRE TO
BRING A STRONG WINTER STORM TO THE UPPER LAKES. ONE IS OVER SRN
SASKATCHEWAN/MT AND THE OTHER IS MOVING ACROSS NV/UT. WELL OUT AHEAD
OF THESE FEATURES...A QUIET NIGHT IS EXPECTED ACROSS THE FCST AREA.
MAINLY CLEAR SKIES INITIALLY WILL GIVE WAY TO INCREASING HIGH AND
MID CLOUDS DURING THE NIGHT. LIGHT WINDS AND LACK OF SIGNIFICANT
CLOUD COVER EARLY SHOULD ALLOW TEMPS OVER THE CNTRL AND E TO FALL
QUICKLY. LEANED TOWARD SOME OF THE COLDER GUIDANCE WITH MINS IN THE
MID TEENS IN THE INTERIOR. OUT W...DEVELOPING LIGHT SOUTHERLY FLOW
AND A QUICKER INCREASE IN CLOUDS SHOULD HOLD TEMPS UP INTO THE
LOW/MID 20S.
ON THU...LOW PRES ORGANIZING OVER THE SRN PLAINS EARLY IN THE MORNING
WILL LIFT NE INTO THE MID MISSISSIPPI VALLEY DURING THE AFTN.
GENERAL MODEL TREND IN THE LAST DAY OR SO HAS BEEN FOR A SLOWER
EXPANSION OF PCPN NE INTO THE UPPER LAKES AS SYSTEM IS TENDING TO
START THE RAPID DEEPENING PHASE MORE QUICKLY BEFORE REACHING THE
UPPER LAKES. OPTED TO FOLLOW THIS TREND AND FAVOR THE SLOWER
SOLUTIONS. AS A RESULT...PCPN ONSET HAS BEEN PUSHED BACK SOME. MAIN
PUSH OF HEAVY PCPN IS NOT EXPECTED UNTIL THU NIGHT WHEN IT WILL
RAPIDLY SPREAD ACROSS THE AREA. INITIALLY...EVAPORATIVE/ADIABATIC
COOLING SHOULD LEAD TO PTYPE AS MAINLY SNOW...BUT DID INCLUDE SOME
MENTION OF MIXED PTYPES OVER ABOUT THE SE HALF.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 518 PM EST WED FEB 19 2014
MAIN CONCERN FOR THE LONG TERM FORECAST IS THE WINTER STORM EXPECTED
ON THURSDAY NIGHT AND FRIDAY.
EARLIER MODEL RUNS HAVE CONSISTENTLY KEPT THE TWO SURFACE LOWS
CROSSING FROM ILLINOIS AND MINNESOTA THURSDAY AFTERNOON TO A MERGED
LOW OVER CENTRAL UPPER MICHIGAN BY LATE THURSDAY EVENING. THIS
BRINGS WARM AIR AND HENCE MIXED PRECIPITATION INTO PORTIONS OF
CENTRAL AND EASTERN UPPER MICHIGAN. CONCERNS THIS PAST FEW DAYS HAVE
BEEN ABOUT THE FORECASTED LOW TRACK SHIFTING AS THE MODELS HAD NOT
REALLY BEEN ABLE TO ADEQUATELY SAMPLE THE SYSTEM UP UNTIL TODAY.
HOWEVER...NOW THAT THE LOW PRESSURE TROUGH RESPONSIBLE FOR THE
DEVELOPMENT OF THIS SYSTEM HAS MOVED ONSHORE IN THE PACIFIC
NORTHWEST...DIFFERENCES IN THE MODELS HAVE DEVELOPED. THE 6Z NAM
BEGAN TRENDING THE SYSTEM EASTWARD...AND THE 12Z NAM HAS COMPLETELY
MOVED THE LOW PRESSURE CENTER LATE THURSDAY EVENING FROM THE CENTRAL
U.P. TO OVER NORTHERN LAKE MICHIGAN. IT IS ALSO SLOWER THAN THE
OTHER SOLUTIONS. FURTHER COMPLICATING MATTERS...THE 12Z GEM MOVED
THE LOW PRESSURE CENTER FURTHER WEST OVER NORTH CENTRAL UPPER
MICHIGAN. THE 12Z GFS HOWEVER...HAS TRENDED SLIGHTLY WESTWARD FROM
ITS 6Z SOLUTION. THIS PUTS THE LOW OVER WESTERN UPPER MI BY 6Z
FRIDAY.
OVERALL...FURTHER EAST SOLUTIONS DIMINISH MIXED PRECIPITATION
CONCERNS AND PULL THE HEAVIEST CORE OF SNOW FURTHER EAST...WHEREAS
PREVIOUS FCST HAD IT MAINLY OVER THE WEST. FOR THIS
FORECAST...DECIDED TO LEAN TOWARDS THE WESTERN SOLUTIONS AS THIS HAS
BEEN THE MORE PERSISTENT SOLUTION. STARTED TRENDING SLIGHTLY MORE
WESTWARD WITH THE FORECAST GRIDS AS A RESULT...NAMELY THE
GFS/GEM/ECMWF COMPROMISE. AS FAR AS TIMING GOES...THE GEM BRINGS
THINGS IN SLOWER. THE 00Z ECMWF/12Z GFS BRING THE LOW THROUGH
QUICKER BY ABOUT 6 HRS...WITH THE CENTER OVER NORTH CENTRAL UPPER MI
BY 6Z FRIDAY. THE GEM IS STILL OVER CENTRAL WI AT THIS TIME.
PREVIOUS RUNS OF THE GEM HAD TIMING MORE LIKE THAT OF THE RECENT
RUNS OF THE ECMWF/GFS...THOUGH THE GFS TENDS TO BE MORE PROGRESSIVE
WITH SYSTEMS. WILL GO MIDDLE OF THE ROAD FOR NOW TO COMPENSATE FOR
THIS.
THE GFS/GEM/ECMWF BLEND SHOWS A BROAD AREA OF ISENTROPIC ASCENT
OVERSPREADING THE AREA STARTING THURSDAY AFTERNOON...WITH THE
STRONGEST MOISTURE TRANSPORT FROM THE 18Z THUR-06Z FRI TIME FRAME
OVER LOWER MICHIGAN...NORTHERN WI...AND CENTRAL/EASTERN UPPER
MICHIGAN. 700/850MB FGEN BAND MOVES FROM ROUGHLY SOUTH TO NORTH
ACROSS THE AREA BEGINNING AROUND THIS TIME AND CONTINUING THROUGH AS
SYSTEM DEEPENS WITH NEGATIVELY TILTING UPPER TROUGH. THE SYSTEM
BEGINS TO OCCLUDE...AND THE TROWAL DEVELOPS AND POSITIONS ITSELF/AND
THE ASSOCIATED FGEN BAND OVER WESTERN UPPER MI.
AS FAR AS PTYPE GOES...THERE ARE DIFFERENCES BETWEEN THE 12Z GFS/12Z
GEM/00Z ECMWF WITH REGARDS TO THE HEIGHT/TEMP OF THE WARMEST LAYER
ALOFT AND DEPTH OF THE SURFACE COLD LAYER FROM 00-03Z FRI...AND THE
SURFACE WARM LAYER AROUND 6-9Z FRI. BY 12Z FRIDAY THE MODELS ARE
CONSISTENT IN HAVING THE WHOLE SOUNDING BELOW ZERO.
IT LOOKS LIKE THE EASTERN HALF WILL SEE THE BEST SHOT FOR FREEZING
RAIN FROM 00-9Z...AND THE RAIN/SNOW LINE SEEMS TO SET UP FROM
EASTERN MARQUETTE COUNTY TO EASTERN DICKINSON COUNTY. ONCE WE GET
PAST 9Z...THE ENTIRE PROFILE IN THIS AREA DROPS BELOW ZERO.
GENERALLY...MIXED PRECIP TIME LOOKS TO BE QUICK ESPECIALLY GIVEN THE
STRONG DYNAMICS IN THE SYSTEM. MAX TS ALOFT REACH A MAX OF 2C WITH
THE WARM GFS...AND STAY BELOW ZERO WITH THE 00Z ECMWF. EAST OF THIS
LINE...WARM LAYER REACHES 3C AROUND 850 AND THE COLD SURFACE LAYER
IS FAIRLY SHALLOW AND EVEN SNEAKS ABOVE ZERO FROM 6-9Z ACCORDING TO
THE GEM...BRINGING A POT POURRI OF PRECIPITATION. THIS AREA IS STILL
ON TRACK FOR SEEING MORE ICE ACCUMULATION. ALL OTHER AREAS WILL BE
PRIMARILY SNOW.
WINDS ARE A CONSIDERABLE ISSUE WITH THIS SYSTEM AS WELL. STRONG
PRESSURE RISE FALL COUPLET SNEAKS IN WITH THE SYSTEM...BRINGING A
SIGNIFICANT ISALLOBARIC COMPONENT TO THE WIND. THIS IS ESPECIALLY
THE CASE ACROSS EASTERN UPPER MICHIGAN EARLY THURSDAY EVENING UNTIL
AROUND 06Z...AND THEN IN THE WEST AND NORTH CENTRAL BY FRIDAY
MORNING/AFTERNOON. THIS WILL ONLY ADD TO THE REDUCED VISIBILITY WITH
EXTENSIVE BLOWING/DRIFTING SNOW. GUSTS IN SOME OF THESE
AREAS...PARTICULARLY THE EXPOSED REGIONS IN THE WEST-NORTHWEST
FAVORED REGIONS...WILL LIKELY SEE GUSTS INTO THE 40S FRIDAY.
GIVEN THE RECENT MODEL RUNS...FELT CONFIDENT ENOUGH TO GO WITH A
WINTER STORM WARNING FOR LOCATIONS WEST OF MARQUETTE/DICKINSON
COUNTIES. SNOW ACCUMULATIONS RANGE FROM ABOUT 8 TO 12 INCHES IN
THESE COUNTIES. ALSO UPGRADED THE BLIZZARD WATCH TO A WARNING FOR
KEWEENAW/N.HOUGHTON COUNTIES GIVEN THE EXTENSIVE WINDS AND SNOW.
OTHERWISE...KEPT THE REST OF THE CWA UNDER A WINTER STORM WATCH TO
PIN DOWN THE DETAILS. IF THE SYSTEM DOES SNEAK EASTWARD...WE MAY
NEED TO ADD ADDITIONAL COUNTIES INTO THE WARNING. MOST OF THE
UNCERTAINTIES WILL IMPACT THE CENTRAL/EASTERN COUNTIES THE MOST...SO
A WATCH SEEMED BEST RIGHT NOW.
FOR THE EXTENDED...WITH THE LINGERING UPPER LEVEL TROUGH IN THE
AREA...EXPECT COLDER TEMPERATURES TO RETURN. 850MB TEMPS WILL DROP
TOWARDS -25C TO -30C AS WE HEAD FURTHER INTO THE LATER TIME PERIODS.
SNOW WILL GRADUALLY CONFINE TO THE WEST WIND FAVORED REGIONS NEAR
LAKE SUPERIOR...AS ICE WILL LIKELY BE BROKEN ENOUGH TO INDUCE
INSTABILITY FOR LES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1229 AM EST THU FEB 20 2014
EXPECT VFR CONDITIONS TO PREVAIL THRU THIS MRNG AS LLVL AIRMASS IS
TOO DRY FOR FOG UNDER A VEIL OF MID/HI CLDS. AS DEEPENING LO PRES
APRCHS UPR MI FM THE S LATER TODAY...EXPECT DETERIORATING CONDITIONS
WITH GUSTY WINDS/SOME LGT SN AND BLSN/MVFR CONDITIONS ARRIVING IN
THE AFTN. CONDITIONS WL FALL TO LIFR/VLIFR FOR AT LEAST SEVERAL HRS
THIS EVNG...MAINLY AT IWD AND CMX WHERE THE PCPN WL BE IN THE FORM
OF HEAVY SN. AN EXTENDED PERIOD OF VLIFR CONDITIONS IS LIKELY AT THE
MORE EXPOSED KCMX SITE BEGINNING TNGT AND LASTING THRU MUCH OF FRI
AS THE MORE EXPOSED KEWEENAW PENINSULA WL BE PLAGUED BY SN/BLSN WITH
VERY STRONG E WINDS SHIFTING TO THE W ONCE THE SFC LO MOVES TO THE N
OF THE AREA LATE TNGT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 518 PM EST WED FEB 19 2014
WINDS WILL DIMINISH THIS EVENING...BECOMING LIGHT UNDER 15KT. WINDS
WILL THEN BEGIN TO INCREASE OVERNIGHT AHEAD OF A WINTER STORM
ORGANIZING OVER THE SOUTHERN PLAINS. E TO NE WINDS MAY REACH UPWARDS
OF 30KT OVER FAR WRN LAKE SUPERIOR BY MORNING. WINDS WILL STEADILY
INCREASE ACROSS THE LAKE THU AS THE ORGANIZING LOW PRES SYSTEM LIFTS
INTO THE MID MISSISSIPPI VALLEY. THE LOW WILL THEN RAPIDLY DEEPEN...
BECOMING AN INTENSE LOW WITH PRES BOTTOMING OUT AROUND 28.7 INCHES
AS IT MOVES NNE ACROSS CNTRL UPPER MI AND CNTRL LAKE SUPERIOR LATE
THU NIGHT AND FRI MORNING. AHEAD OF THE LOW...EASTERLY GALES WILL
DEVELOP OVER CNTRL AND ERN LAKE SUPERIOR THU EVENING. WHILE E TO NE
GALES MAY ALSO DEVELOP OVER WRN LAKE SUPERIOR...W GALES ARE MORE
LIKELY IN THE WAKE OF THE LOW FRI/FRI NIGHT. GALES WILL CONTINUE
OVER CNTRL AND ERN LAKE SUPERIOR FRI THRU SAT WITH THE POTENTIAL FOR
STORM FORCE WINDS OVER ERN LAKE SUPERIOR FRI. ALTHOUGH GALES WILL
END BY SUN...WINDS WILL LIKELY REMAIN IN THE 20-30KT RANGE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WARNING FROM 4 PM EST /3 PM CST/ THIS AFTERNOON TO
NOON EST /11 AM CST/ FRIDAY FOR MIZ002-004-009-010-084.
WINTER STORM WATCH FROM THIS AFTERNOON THROUGH FRIDAY MORNING
FOR MIZ006-007-012>014-085.
BLIZZARD WARNING FROM 7 PM THIS EVENING TO 10 PM EST FRIDAY FOR
MIZ001-003.
WINTER STORM WATCH FROM THIS AFTERNOON THROUGH FRIDAY MORNING
FOR MIZ005-011.
LAKE SUPERIOR...
GALE WARNING FROM 7 PM THIS EVENING TO 6 PM EST SATURDAY FOR
LSZ244-245-264>267.
GALE WARNING FROM 7 AM EST /6 AM CST/ FRIDAY TO 7 AM EST /6 AM
CST/ SATURDAY FOR LSZ162-241>243-263.
LAKE MICHIGAN...
GALE WARNING FROM 7 PM THIS EVENING TO 5 PM EST FRIDAY FOR
LMZ221-248-250.
&&
$$
UPDATE...KC
SHORT TERM...ROLFSON
LONG TERM...MCD
AVIATION...KC
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1142 AM CST Thu Feb 20 2014
.UPDATE:
Issued at 1032 AM CST Thu Feb 20 2014
Surface low in the MKC vicinity will deepen and move northeastward
this afternoon and evening in response the strong upstream
shortwave trof progressing into and across the region. The
attendant cold front is still forecast to begin accelerating and
sweep across the CWA this afternoon, exiting our south central IL
counties near 00Z. Winds will be increasing both ahead and
especially behind the cold front, with mixing and a tight pressure
gradient associated with the deepening low contributing to strong
post-frontal sw/w winds gusting from 45-50 mph. The current wind
advisory looks right on target, although the timing of the cold
front passage in IL has resulted in moving up the onset of the
wind advisory to 21Z to the east of the MS river. Still monitoring
the severe weather potential for this afternoon. The amount of
instability is the biggest unknown. The RAP and NAM both have
SBCAPE increasing to above 1000 j/kg by mid-afternoon in a
north/south corridor across eastern MO just ahead of the cold
front but based on the latest SPC mesoanalysis, this may be a
little high. If we can get tds into the u50s and some decent
heating this may materialize, otherwise 500-1000 j/kg seems more
probable. The very strong wind fields will support a threat of
damaging winds with any strong storms, with higher CAPE values
supporting greater storm coverage and damaging wind potential as
well as isolated tornadoes. Present indications are that scattered
storms should develop along the front this afternoon in response
to linear forcing associated with the front and upper wave, likely
between Columbia and St. Louis, but possibly as far west as COU.
Eventually upscale growth will result in a strongly forced line of
storms, most likely evolving near or just east of St. Louis.
Glass
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 405 AM CST Thu Feb 20 2014
It`s going to be one of those days.
Lots of wx expected so here goes. At 09z, surface obs show a warm
front poking into central MO near COU/JEF and then sagging somewhat
down to near FAM. Temps rise quickly into the 50s with warm FROPA
with dewpoints in the 50s following not long thereafter. Temps are
only in the 30s for the far northern CWA, including UIN. Radar
shows a cluster of TSRA in southwest MO moving northeast. Much of
the rest of the area just has scattered SHRA or nothing at all with
much of the pcpn from earlier having shifted further north.
Pcpn chances: local 4km WRF model has an excellent handle on things
and used this for primary guidance today. It tracks the cluster of
TSRA northeast thru most of central...east-central MO and southwest
IL this morning. Then a lull in the action for much of our region
from just before midday thru about mid-afternoon. All models are on
board with a slower frontal timing and by all accounts should see
sfc-based TSRA develop along cold front between 20-21z from
UIN-STL-UNO and then expand and continue to track eastward along
front for remainder of the afternoon...exiting around 00z. Could
see severe chances being revisited despite current SPC day 1 outlook
if this scenario verifies.
Flood potential: combo of very moist soil/frozen soil and QPF and
still existant snowpack is best in northeast MO and west-central IL
and current flood watch is justified. More in doubt in central MO,
though, where snow melted a couple days ago, soil is not frozen but
is moist, but QPF also more limited with what moves thru with the
cluster of TSRA to the south probably it for the day. Will trim
flood watch to remove pertinent sections of central MO.
Winds: strong lo level jet of 50kts already exists but passage of
warm front will not allow too much mixing, either, with gusts
expected to reach to 30-35mph. The really strong gusts will hold
off until passage of cold front later this afternoon, allowing for
deeper mixing and tapping the high winds aloft. Looks like gusts
45-50mph will be common across much of the area at some point into
the evening, perhaps longer, and will issue a Wind Advisory.
Temps: a challenge to say the least. Clouds and pcpn will try to
keep the warmup in check, but dry slot also expected to push into
STL metro and areas S and E later today and allow for decent rise to
near 70F. Look for temp fall for central-northeast MO this
afternoon behind front.
TES
.LONG TERM: (Tonight through Wednesday)
Issued at 405 AM CST Thu Feb 20 2014
Showers and thunderstorms along a fast moving cold front should
shift rapidly east of our forecast area by late evening. Some
light rain/snow in the southwestern tail of the deformation zone,
wrap around precipitation may graze our nern MO and w central IL
counties early this evening. Strong and gusty winds will continue
this evening due to the tight surface pressure gradient behind the
deepening surface low moving northeastward through WI this
evening. The winds should begin to gradually slacken by late
tonight. Much colder temperatures tonight due to low level cold
air advection behind the cold front this evening, a clearing sky,
and lowering surface dew points tonight. This cooling trend will
be short lived as 850 mb temperatures slowly warm from sw to ne on
Friday. Although Fridays highs will not be as warm as Thursday
they will still be above normal. A weak cold front will sag slowly
southward through our forecast area late Friday night and
Saturday. There could be patchy light rain or snow along this
front. Should be the start of a gradual cooling trend Saturday
night and Sunday as a large and relatively strong surface ridge
builds southeastward into our area from the northern Plains. The
ECMWF model was depicting some light qpf Monday and Monday night
across our forecast area, which should be mainly in the form of
snow, due to low-mid level warm air advection ahead of a
southeastward moving shortwave moving through the northern Plains.
The GFS model keeps most of the precipitation north of our
forecast area. Even colder, well below normal temperatures
expected for Tuesday night as another surface ridge builds
southeastward into our area.
GKS
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1127 AM CST Thu Feb 20 2014
Surface low now NW of KMKC will move northeastward this afternoon
and tonight with the warm front lifting northward through KUIN
within the next hour or so, and the trailing cold front sweeping
eastward across the area this afternoon. Predominately VFR
conditons are expected ahead of the cold front along with gusty
southerly winds. The exception is with any thunderstorms occurring
along/ahead of front which could drop flight conditions briefly
to IFR and contain strong winds. Coverage of any storms is hard to
judge at this time and thus have just mentioned Vicinity in the
current TAFS and will update as needed once coverage and impacts
can be determined. Very strong southwest-west winds gusting 38-45
kts will occur with the passage of the cold front, along with a
period of MVFR cigs. Clouds will clear this evening and the winds
should diminish some this evening but will remain gusty through
the period.
Specifics for KSTL:
VFR conditions and gusty southerly winds are expected until a cold front
passage around 22z. Thunderstorm chances/coverage with the cold
front are hard to judge at this time, and thus have kept with a
mention of VCTS and will update if needed once coverage and impacts
can be determined. Very strong southwest-west winds gusting 38-45
kts will occur with the passage of the cold front at 22z, along
with a period of MVFR cigs into mid-evening. Clouds will clear
around 02-03z and the winds should diminish some this evening but
will remain gusty through the period.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WIND ADVISORY until Midnight CST tonight FOR Audrain MO-Boone MO-
Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
Iron MO-Jefferson MO-Knox MO-Lewis MO-Lincoln MO-Madison MO-
Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike
MO-Ralls MO-Reynolds MO-Shelby MO-St. Charles MO-St.
Francois MO-St. Louis City MO-St. Louis MO-Ste. Genevieve
MO-Warren MO-Washington MO.
FLOOD WATCH until 6 PM CST this evening FOR Knox MO-Lewis MO-
Marion MO-Shelby MO.
IL...WIND ADVISORY until Midnight CST tonight FOR Adams IL-Brown IL-
Calhoun IL-Greene IL-Jersey IL-Macoupin IL-Madison IL-
Monroe IL-Pike IL-St. Clair IL.
WIND ADVISORY from 3 PM this afternoon to Midnight CST tonight
FOR Bond IL-Clinton IL-Fayette IL-Marion IL-Montgomery IL-
Randolph IL-Washington IL.
FLOOD WATCH until 6 PM CST this evening FOR Adams IL-Brown IL-
Greene IL-Macoupin IL-Montgomery IL-Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1140 AM CST Thu Feb 20 2014
.UPDATE...
Issued at 1001 AM CST THU FEB 20 2014
Latest model data and trends from radar indicate that north central
to northeast Missouri will likely be spared from widespread rains
that could induce flooding. Therefore have dropped the Flood Watch
for that was still in effect for that section of the forecast area.
Shower and thunderstorm activity will remain focused more across
northeast Kansas and northwest Missouri this morning where a
combination of rain, changing to sleet and snow, will occur through
the early afternoon hours. Snowfall totals in far northwest Missouri
remain very difficult to forecast owing to the fact that surface
temperatures are currently, and are expected to remain, above
freezing through much of the daylight hours while its precipitating.
But, the dynamics of the deformation band aloft still look sufficient
to put down a couple quick inches of slushy accumulations from
Maryville south through St Joseph and possibly into the far northern
side of Kansas City...and as far east as Interstate 35.
&&
.SHORT TERM...(Today and Tonight)
Issued at 430 AM CST THU FEB 20 2014
At the surface a very strong trough has formed on the eastern side
of the Rocky mountains, and currently sits over SC/SE Kansas. The
surface pressure gradient associated with this very strong trough
will cause southerly winds to pick up on the eastern edge to around
20 to 30 mph with gusts approaching 40 mph later today. An evident
surface warm front currently sits along Interstate 70, and is
characterized by temperatures in the 30s to lower 40s north of the
boundary to temperatures well in the 50s to lower 60s in the warm
sector south of the boundary. Thunderstorms are currently forming
along along the advancing warm front and will have plenty of
instability to grow upscale into strong thunderstorms. This activity
is generally forming along a strong low level jet which is currently
nosing into western Missouri, and is characterized by strong 850
winds between 50 and 60 kts. Effective bulk shear is between 40 and
50 kts, and given strong MU elevated CAPE of around 1000 J/kg the
ingredients are in place for these storms to be strong to marginally
severe. As the morning progresses HRRR indicates that these storms
will form a line spanning west to east just north of Interstate 70,
and will lift north through the day. Expect the bulk of the strong
thunderstorm potential to move northward into Iowa by around 10 am.
The focus then shifts to the late morning and afternoon hours, when
areas of far northwestern Missouri could experience a period of
moderate to heavy snow. The main mid level trough, which currently
sits over the High Plains will swing through the area later this
afternoon. Southern and Central Missouri will likely see a down tick
in precipitation coverage as the systems dry slot races through
southern and central Missouri. Across northern Missouri large scale
ascent associated with the mid level trough will bring another round
of precipitation later this morning. The aforementioned surface
trough will continue eastward, and behind the departing trough cold
northwest winds will crash into the area causing the thermal profile
to cool very quickly. By mid morning the thermal profile along
northern Missouri will be cooled adequately for snow production.
Very strong low/mid level frontogenesis in northern Missouri, as
well as some negative EPV will enhance the lift associated with the
mid level wave. All told there could be up to 15 to 20 -ubar of
Omega this morning and this afternoon contributing to rather
efficient snow production. While cold air will rush in surface
temperatures will struggle to drop below freezing, so any snow
production and accumulation may be mitigated by the warmer surface
temperatures. Went with a general 10-12:1 snow ratio to attain a
final figure of around 2 to 4 inches of snow accumulation for the
far NW corner of Missouri, with decreasing amounts toward the east
and south. Concurrent to the snow will be strong northwest winds,
which will race in as the surface pressure gradient behind the
departing trough moves through the area this afternoon. Expect the
winds to be sustained out of the northwest around 30 to 40 mph, with
gusts perhaps exceeding 50 mph. The strong winds and period of
moderate to heavy snow will cause visibility to decrease through the
day. Expect the period of snowfall to be rather brief as the overall
system quickly glides off to the northeast. By mid afternoon expect
the bulk of the precipitation to be off to the north, with perhaps
some lingering rain/snow through the evening.
Model soundings indicate that the low levels could stay well mixed
through the evening and into the overnight hours, which would allow
the strong wind gusts to continue at least into the evening and
perhaps into the overnight hours before gradually dissipating early
Friday morning.
.LONG TERM...(Friday through Wednesday)
Issued at 430 AM CST THU FEB 20 2014
A return to a West Coast blocking pattern, similar to what prevailed
through much of January, will send us back into a cold and dry
pattern by early next week. Primary cold front will drop into the
forecast area Friday night with a reinforcing shot of cold air
arriving Sunday. Temperatures in this pattern won`t be near as cold
as they were back in January, but still about 10 degrees below
average with highs in the 20s and 30s and lows in the teens and 20s
for much of next week. Could see some light snow Monday and Monday
night with a broad upper impulse tracking through the Upper Midwest
but better chances will be to our north.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1139 AM CST THU FEB 20 2014
Most of the thunderstorm activity cleared the terminals by the late
morning hours, and while a few more showers and isolated
thunderstorms may be possible any of that activity will likely occur
to the east of our locations. Now waiting for a band of rain, sleet
and snow to move across western Missouri this afternoon. Conditions
should be a bit worse the farther north you go, but with above
freezing surface temperatures prevailing precipitation type will be
hard to pin down. Otherwise, strong and gusty northwest winds will
persist through the rest of the daylight hours diminishing this
evening as they back to the west. The decrease in wind speed should
accompany VFR conditions.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY until 9 PM CST this evening FOR KSZ025-057-060-
102>105.
WINTER WEATHER ADVISORY until 3 PM CST this afternoon FOR KSZ025-
102.
MO...WIND ADVISORY until 9 PM CST this evening FOR MOZ001>005-011>014-
020>022-028>031-037>040-043>046-053-054.
WINTER WEATHER ADVISORY until 3 PM CST this afternoon FOR
MOZ001>005-011>013-020.
WIND ADVISORY until Midnight CST tonight FOR MOZ006>008-015>017-
023>025-032-033.
&&
$$
UPDATE...Cutter
SHORT TERM...Leighton
LONG TERM...Hawblitzel
AVIATION...Cutter
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1040 AM CST Thu Feb 20 2014
.UPDATE:
Issued at 1032 AM CST Thu Feb 20 2014
Surface low in the MKC vicinity will deepen and move northeastward
this afternoon and evening in response the strong upstream
shortwave trof progressing into and across the region. The
attendant cold front is still forecast to begin accelerating and
sweep across the CWA this afternoon, exiting our south central IL
counties near 00Z. Winds will be increasing both ahead and
especially behind the cold front, with mixing and a tight pressure
gradient associated with the deepening low contributing to strong
post-frontal sw/w winds gusting from 45-50 mph. The current wind
advisory looks right on target, although the timing of the cold
front passage in IL has resulted in moving up the onset of the
wind advisory to 21Z to the east of the MS river. Still monitoring
the severe weather potential for this afternoon. The amount of
instability is the biggest unknown. The RAP and NAM both have
SBCAPE increasing to above 1000 j/kg by mid-afternoon in a
north/south corridor across eastern MO just ahead of the cold
front but based on the latest SPC mesoanalysis, this may be a
little high. If we can get tds into the u50s and some decent
heating this may materialize, otherwise 500-1000 j/kg seems more
probable. The very strong wind fields will support a threat of
damaging winds with any strong storms, with higher CAPE values
supporting greater storm coverage and damaging wind potential as
well as isolated tornadoes. Present indications are that scattered
storms should develop along the front this afternoon in response
to linear forcing associated with the front and upper wave, likely
between Columbia and St. Louis, but possibly as far west as COU.
Eventually upscale growth will result in a strongly forced line of
storms, most likely evolving near or just east of St. Louis.
Glass
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 405 AM CST Thu Feb 20 2014
It`s going to be one of those days.
Lots of wx expected so here goes. At 09z, surface obs show a warm
front poking into central MO near COU/JEF and then sagging somewhat
down to near FAM. Temps rise quickly into the 50s with warm FROPA
with dewpoints in the 50s following not long thereafter. Temps are
only in the 30s for the far northern CWA, including UIN. Radar
shows a cluster of TSRA in southwest MO moving northeast. Much of
the rest of the area just has scattered SHRA or nothing at all with
much of the pcpn from earlier having shifted further north.
Pcpn chances: local 4km WRF model has an excellent handle on things
and used this for primary guidance today. It tracks the cluster of
TSRA northeast thru most of central...east-central MO and southwest
IL this morning. Then a lull in the action for much of our region
from just before midday thru about mid-afternoon. All models are on
board with a slower frontal timing and by all accounts should see
sfc-based TSRA develop along cold front between 20-21z from
UIN-STL-UNO and then expand and continue to track eastward along
front for remainder of the afternoon...exiting around 00z. Could
see severe chances being revisited despite current SPC day 1 outlook
if this scenario verifies.
Flood potential: combo of very moist soil/frozen soil and QPF and
still existant snowpack is best in northeast MO and west-central IL
and current flood watch is justified. More in doubt in central MO,
though, where snow melted a couple days ago, soil is not frozen but
is moist, but QPF also more limited with what moves thru with the
cluster of TSRA to the south probably it for the day. Will trim
flood watch to remove pertinent sections of central MO.
Winds: strong lo level jet of 50kts already exists but passage of
warm front will not allow too much mixing, either, with gusts
expected to reach to 30-35mph. The really strong gusts will hold
off until passage of cold front later this afternoon, allowing for
deeper mixing and tapping the high winds aloft. Looks like gusts
45-50mph will be common across much of the area at some point into
the evening, perhaps longer, and will issue a Wind Advisory.
Temps: a challenge to say the least. Clouds and pcpn will try to
keep the warmup in check, but dry slot also expected to push into
STL metro and areas S and E later today and allow for decent rise to
near 70F. Look for temp fall for central-northeast MO this
afternoon behind front.
TES
.LONG TERM: (Tonight through Wednesday)
Issued at 405 AM CST Thu Feb 20 2014
Showers and thunderstorms along a fast moving cold front should
shift rapidly east of our forecast area by late evening. Some
light rain/snow in the southwestern tail of the deformation zone,
wrap around precipitation may graze our nern MO and w central IL
counties early this evening. Strong and gusty winds will continue
this evening due to the tight surface pressure gradient behind the
deepening surface low moving northeastward through WI this
evening. The winds should begin to gradually slacken by late
tonight. Much colder temperatures tonight due to low level cold
air advection behind the cold front this evening, a clearing sky,
and lowering surface dew points tonight. This cooling trend will
be short lived as 850 mb temperatures slowly warm from sw to ne on
Friday. Although Fridays highs will not be as warm as Thursday
they will still be above normal. A weak cold front will sag slowly
southward through our forecast area late Friday night and
Saturday. There could be patchy light rain or snow along this
front. Should be the start of a gradual cooling trend Saturday
night and Sunday as a large and relatively strong surface ridge
builds southeastward into our area from the northern Plains. The
ECMWF model was depicting some light qpf Monday and Monday night
across our forecast area, which should be mainly in the form of
snow, due to low-mid level warm air advection ahead of a
southeastward moving shortwave moving through the northern Plains.
The GFS model keeps most of the precipitation north of our
forecast area. Even colder, well below normal temperatures
expected for Tuesday night as another surface ridge builds
southeastward into our area.
GKS
&&
.AVIATION: (For the 12z TAFs through 12z Friday Morning)
Issued at 615 AM CST Thu Feb 20 2014
Warm front now pushing thru I-70 corridor TAF sites and should
further enhance probs of reaching IFR CIGs for areas to the north
this morning: namely UIN. Further to the south, CIGs will bounce
around until warm front gets further north thru these areas with
advance of dry slot later in the day to have CIGs either go
solidly VFR or breakup. Pcpn expected to largely exit the area by
late morning as well. Cold front will shift winds to SW-W,
increase them substantially, and ignite a new round of TSRA for
STL metro for a short period this afternoon before it heads east.
Strong W winds will then persist into this evening before slow
diminishment.
Specifics for KSTL: TSRA thru mid-morning with CIGs bouncing
around before a more steady period of VFR and dry for late
morning and early afternoon. Cold front late this afternoon will
attempt to ignite a new round of TSRA and strengthen the winds as
they shift out of the west. The strong W winds will then continue
into the evening before a slow diminishment.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WIND ADVISORY until Midnight CST tonight FOR Audrain MO-Boone MO-
Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
Iron MO-Jefferson MO-Knox MO-Lewis MO-Lincoln MO-Madison MO-
Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike
MO-Ralls MO-Reynolds MO-Shelby MO-St. Charles MO-St.
Francois MO-St. Louis City MO-St. Louis MO-Ste. Genevieve
MO-Warren MO-Washington MO.
FLOOD WATCH until 6 PM CST this evening FOR Knox MO-Lewis MO-
Marion MO-Shelby MO.
IL...WIND ADVISORY until Midnight CST tonight FOR Adams IL-Brown IL-
Calhoun IL-Greene IL-Jersey IL-Macoupin IL-Madison IL-
Monroe IL-Pike IL-St. Clair IL.
WIND ADVISORY from 3 PM this afternoon to Midnight CST tonight
FOR Bond IL-Clinton IL-Fayette IL-Marion IL-Montgomery IL-
Randolph IL-Washington IL.
FLOOD WATCH until 6 PM CST this evening FOR Adams IL-Brown IL-
Greene IL-Macoupin IL-Montgomery IL-Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1007 AM CST Thu Feb 20 2014
.UPDATE...
Issued at 1001 AM CST THU FEB 20 2014
Latest model data and trends from radar indicate that north central
to northeast Missouri will likely be spared from widespread rains
that could induce flooding. Therefore have dropped the Flood Watch
for that was still in effect for that section of the forecast area.
Shower and thunderstorm activity will remain focused more across
northeast Kansas and northwest Missouri this morning where a
combination of rain, changing to sleet and snow, will occur through
the early afternoon hours. Snowfall totals in far northwest Missouri
remain very difficult to forecast owing to the fact that surface
temperatures are currently, and are expected to remain, above
freezing through much of the daylight hours while its precipitating.
But, the dynamics of the deformation band aloft still look sufficient
to put down a couple quick inches of slushy accumulations from
Maryville south through St Joseph and possibly into the far northern
side of Kansas City...and as far east as Interstate 35.
&&
.SHORT TERM...(Today and Tonight)
Issued at 430 AM CST THU FEB 20 2014
At the surface a very strong trough has formed on the eastern side
of the Rocky mountains, and currently sits over SC/SE Kansas. The
surface pressure gradient associated with this very strong trough
will cause southerly winds to pick up on the eastern edge to around
20 to 30 mph with gusts approaching 40 mph later today. An evident
surface warm front currently sits along Interstate 70, and is
characterized by temperatures in the 30s to lower 40s north of the
boundary to temperatures well in the 50s to lower 60s in the warm
sector south of the boundary. Thunderstorms are currently forming
along along the advancing warm front and will have plenty of
instability to grow upscale into strong thunderstorms. This activity
is generally forming along a strong low level jet which is currently
nosing into western Missouri, and is characterized by strong 850
winds between 50 and 60 kts. Effective bulk shear is between 40 and
50 kts, and given strong MU elevated CAPE of around 1000 J/kg the
ingredients are in place for these storms to be strong to marginally
severe. As the morning progresses HRRR indicates that these storms
will form a line spanning west to east just north of Interstate 70,
and will lift north through the day. Expect the bulk of the strong
thunderstorm potential to move northward into Iowa by around 10 am.
The focus then shifts to the late morning and afternoon hours, when
areas of far northwestern Missouri could experience a period of
moderate to heavy snow. The main mid level trough, which currently
sits over the High Plains will swing through the area later this
afternoon. Southern and Central Missouri will likely see a down tick
in precipitation coverage as the systems dry slot races through
southern and central Missouri. Across northern Missouri large scale
ascent associated with the mid level trough will bring another round
of precipitation later this morning. The aforementioned surface
trough will continue eastward, and behind the departing trough cold
northwest winds will crash into the area causing the thermal profile
to cool very quickly. By mid morning the thermal profile along
northern Missouri will be cooled adequately for snow production.
Very strong low/mid level frontogenesis in northern Missouri, as
well as some negative EPV will enhance the lift associated with the
mid level wave. All told there could be up to 15 to 20 -ubar of
Omega this morning and this afternoon contributing to rather
efficient snow production. While cold air will rush in surface
temperatures will struggle to drop below freezing, so any snow
production and accumulation may be mitigated by the warmer surface
temperatures. Went with a general 10-12:1 snow ratio to attain a
final figure of around 2 to 4 inches of snow accumulation for the
far NW corner of Missouri, with decreasing amounts toward the east
and south. Concurrent to the snow will be strong northwest winds,
which will race in as the surface pressure gradient behind the
departing trough moves through the area this afternoon. Expect the
winds to be sustained out of the northwest around 30 to 40 mph, with
gusts perhaps exceeding 50 mph. The strong winds and period of
moderate to heavy snow will cause visibility to decrease through the
day. Expect the period of snowfall to be rather brief as the overall
system quickly glides off to the northeast. By mid afternoon expect
the bulk of the precipitation to be off to the north, with perhaps
some lingering rain/snow through the evening.
Model soundings indicate that the low levels could stay well mixed
through the evening and into the overnight hours, which would allow
the strong wind gusts to continue at least into the evening and
perhaps into the overnight hours before gradually dissipating early
Friday morning.
.LONG TERM...(Friday through Wednesday)
Issued at 430 AM CST THU FEB 20 2014
A return to a West Coast blocking pattern, similar to what prevailed
through much of January, will send us back into a cold and dry
pattern by early next week. Primary cold front will drop into the
forecast area Friday night with a reinforcing shot of cold air
arriving Sunday. Temperatures in this pattern won`t be near as cold
as they were back in January, but still about 10 degrees below
average with highs in the 20s and 30s and lows in the teens and 20s
for much of next week. Could see some light snow Monday and Monday
night with a broad upper impulse tracking through the Upper Midwest
but better chances will be to our north.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 516 AM CST THU FEB 20 2014
Cluster of thunderstorms currently affecting KMCI and KSTJ will move
off to the north within the next couple hours. Not expecting much in
the way of convective redevelopment once these showers pass, however
there will be the chance for some light rain/snow mix later this
afternoon. The bigger story for this afternoon will be the very
strong winds, which will race into the area bringing 30 to 40 kt
gusts later this afternoon. Expect winds to gradually dissipate later
this evening, but winds will still be out of the northwest around 15
to 25 kts.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY until 9 PM CST this evening FOR KSZ025-057-060-
102>105.
WINTER WEATHER ADVISORY until 3 PM CST this afternoon FOR KSZ025-
102.
MO...WIND ADVISORY until 9 PM CST this evening FOR MOZ001>005-011>014-
020>022-028>031-037>040-043>046-053-054.
WINTER WEATHER ADVISORY until 3 PM CST this afternoon FOR
MOZ001>005-011>013-020.
WIND ADVISORY from 1 PM this afternoon to Midnight CST tonight
FOR MOZ006>008-015>017-023>025-032-033.
&&
$$
UPDATE...Cutter
SHORT TERM...Leighton
LONG TERM...Hawblitzel
AVIATION...Leighton
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
521 AM CST Thu Feb 20 2014
.SHORT TERM...(Today and Tonight)
Issued at 430 AM CST THU FEB 20 2014
At the surface a very strong trough has formed on the eastern side
of the Rocky mountains, and currently sits over SC/SE Kansas. The
surface pressure gradient associated with this very strong trough
will cause southerly winds to pick up on the eastern edge to around
20 to 30 mph with gusts approaching 40 mph later today. An evident
surface warm front currently sits along Interstate 70, and is
characterized by temperatures in the 30s to lower 40s north of the
boundary to temperatures well in the 50s to lower 60s in the warm
sector south of the boundary. Thunderstorms are currently forming
along along the advancing warm front and will have plenty of
instability to grow upscale into strong thunderstorms. This activity
is generally forming along a strong low level jet which is currently
nosing into western Missouri, and is characterized by strong 850
winds between 50 and 60 kts. Effective bulk shear is between 40 and
50 kts, and given strong MU elevated CAPE of around 1000 J/kg the
ingredients are in place for these storms to be strong to marginally
severe. As the morning progresses HRRR indicates that these storms
will form a line spanning west to east just north of Interstate 70,
and will lift north through the day. Expect the bulk of the strong
thunderstorm potential to move northward into Iowa by around 10 am.
The focus then shifts to the late morning and afternoon hours, when
areas of far northwestern Missouri could experience a period of
moderate to heavy snow. The main mid level trough, which currently
sits over the High Plains will swing through the area later this
afternoon. Southern and Central Missouri will likely see a down tick
in precipitation coverage as the systems dry slot races through
southern and central Missouri. Across northern Missouri large scale
ascent associated with the mid level trough will bring another round
of precipitation later this morning. The aforementioned surface
trough will continue eastward, and behind the departing trough cold
northwest winds will crash into the area causing the thermal profile
to cool very quickly. By mid morning the thermal profile along
northern Missouri will be cooled adequately for snow production.
Very strong low/mid level frontogenesis in northern Missouri, as
well as some negative EPV will enhance the lift associated with the
mid level wave. All told there could be up to 15 to 20 -ubar of
Omega this morning and this afternoon contributing to rather
efficient snow production. While cold air will rush in surface
temperatures will struggle to drop below freezing, so any snow
production and accumulation may be mitigated by the warmer surface
temperatures. Went with a general 10-12:1 snow ratio to attain a
final figure of around 2 to 4 inches of snow accumulation for the
far NW corner of Missouri, with decreasing amounts toward the east
and south. Concurrent to the snow will be strong northwest winds,
which will race in as the surface pressure gradient behind the
departing trough moves through the area this afternoon. Expect the
winds to be sustained out of the northwest around 30 to 40 mph, with
gusts perhaps exceeding 50 mph. The strong winds and period of
moderate to heavy snow will cause visibility to decrease through the
day. Expect the period of snowfall to be rather brief as the overall
system quickly glides off to the northeast. By mid afternoon expect
the bulk of the precipitation to be off to the north, with perhaps
some lingering rain/snow through the evening.
Model soundings indicate that the low levels could stay well mixed
through the evening and into the overnight hours, which would allow
the strong wind gusts to continue at least into the evening and
perhaps into the overnight hours before gradually dissipating early
Friday morning.
.LONG TERM...(Friday through Wednesday)
Issued at 430 AM CST THU FEB 20 2014
A return to a West Coast blocking pattern, similar to what prevailed
through much of January, will send us back into a cold and dry
pattern by early next week. Primary cold front will drop into the
forecast area Friday night with a reinforcing shot of cold air
arriving Sunday. Temperatures in this pattern won`t be near as cold
as they were back in January, but still about 10 degrees below
average with highs in the 20s and 30s and lows in the teens and 20s
for much of next week. Could see some light snow Monday and Monday
night with a broad upper impulse tracking through the Upper Midwest
but better chances will be to our north.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 516 AM CST THU FEB 20 2014
Cluster of thunderstorms currently affecting KMCI and KSTJ will move
off to the north within the next couple hours. Not expecting much in
the way of convective redevelopment once these showers pass, however
there will be the chance for some light rain/snow mix later this
afternoon. The bigger story for this afternoon will be the very
strong winds, which will race into the area bringing 30 to 40 kt
gusts later this afternoon. Expect winds to gradually dissipate later
this evening, but winds will still be out of the northwest around 15
to 25 kts.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY from 10 AM this morning to 9 PM CST this evening
FOR KSZ025-057-060-102>105.
WINTER WEATHER ADVISORY until 3 PM CST this afternoon FOR KSZ025-
102.
MO...WIND ADVISORY from 10 AM this morning to 9 PM CST this evening
FOR MOZ001>005-011>014-020>022-028>031-037>040-043>046-053-
054.
WINTER WEATHER ADVISORY until 3 PM CST this afternoon FOR
MOZ001>005-011>013-020.
WIND ADVISORY from 1 PM this afternoon to Midnight CST tonight
FOR MOZ006>008-015>017-023>025-032-033.
FLOOD WATCH through this afternoon FOR MOZ006>008-015>017-
023>025.
&&
$$
SHORT TERM...Leighton
LONG TERM...Hawblitzel
AVIATION...Leighton
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
434 AM CST Thu Feb 20 2014
.SHORT TERM...(Today and Tonight)
Issued at 430 AM CST THU FEB 20 2014
At the surface a very strong trough has formed on the eastern side
of the Rocky mountains, and currently sits over SC/SE Kansas. The
surface pressure gradient associated with this very strong trough
will cause southerly winds to pick up on the eastern edge to around
20 to 30 mph with gusts approaching 40 mph later today. An evident
surface warm front currently sits along Interstate 70, and is
characterized by temperatures in the 30s to lower 40s north of the
boundary to temperatures well in the 50s to lower 60s in the warm
sector south of the boundary. Thunderstorms are currently forming
along along the advancing warm front and will have plenty of
instability to grow upscale into strong thunderstorms. This activity
is generally forming along a strong low level jet which is currently
nosing into western Missouri, and is characterized by strong 850
winds between 50 and 60 kts. Effective bulk shear is between 40 and
50 kts, and given strong MU elevated CAPE of around 1000 J/kg the
ingredients are in place for these storms to be strong to marginally
severe. As the morning progresses HRRR indicates that these storms
will form a line spanning west to east just north of Interstate 70,
and will lift north through the day. Expect the bulk of the strong
thunderstorm potential to move northward into Iowa by around 10 am.
The focus then shifts to the late morning and afternoon hours, when
areas of far northwestern Missouri could experience a period of
moderate to heavy snow. The main mid level trough, which currently
sits over the High Plains will swing through the area later this
afternoon. Southern and Central Missouri will likely see a down tick
in precipitation coverage as the systems dry slot races through
southern and central Missouri. Across northern Missouri large scale
ascent associated with the mid level trough will bring another round
of precipitation later this morning. The aforementioned surface
trough will continue eastward, and behind the departing trough cold
northwest winds will crash into the area causing the thermal profile
to cool very quickly. By mid morning the thermal profile along
northern Missouri will be cooled adequately for snow production.
Very strong low/mid level frontogenesis in northern Missouri, as
well as some negative EPV will enhance the lift associated with the
mid level wave. All told there could be up to 15 to 20 -ubar of
Omega this morning and this afternoon contributing to rather
efficient snow production. While cold air will rush in surface
temperatures will struggle to drop below freezing, so any snow
production and accumulation may be mitigated by the warmer surface
temperatures. Went with a general 10-12:1 snow ratio to attain a
final figure of around 2 to 4 inches of snow accumulation for the
far NW corner of Missouri, with decreasing amounts toward the east
and south. Concurrent to the snow will be strong northwest winds,
which will race in as the surface pressure gradient behind the
departing trough moves through the area this afternoon. Expect the
winds to be sustained out of the northwest around 30 to 40 mph, with
gusts perhaps exceeding 50 mph. The strong winds and period of
moderate to heavy snow will cause visibility to decrease through the
day. Expect the period of snowfall to be rather brief as the overall
system quickly glides off to the northeast. By mid afternoon expect
the bulk of the precipitation to be off to the north, with perhaps
some lingering rain/snow through the evening.
Model soundings indicate that the low levels could stay well mixed
through the evening and into the overnight hours, which would allow
the strong wind gusts to continue at least into the evening and
perhaps into the overnight hours before gradually dissipating early
Friday morning.
.LONG TERM...(Friday through Wednesday)
Issued at 430 AM CST THU FEB 20 2014
A return to a West Coast blocking pattern, similar to what prevailed
through much of January, will send us back into a cold and dry
pattern by early next week. Primary cold front will drop into the
forecast area Friday night with a reinforcing shot of cold air
arriving Sunday. Temperatures in this pattern won`t be near as cold
as they were back in January, but still about 10 degrees below
average with highs in the 20s and 30s and lows in the teens and 20s
for much of next week. Could see some light snow Monday and Monday
night with a broad upper impulse tracking through the Upper Midwest
but better chances will be to our north.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1130 PM CST WED FEB 19 2014
Scattered showers and occasional, isolated thunderstorms will
continue through the night across most of the region ahead of a
northeastward moving warm front. As the warm front approaches between
10z-12z Thursday, another round of more robust thunderstorms are
possible, especially along and north of Interstate 70. South of the
front, IFR to LIFR stratus and some light fog are expected to spread
into the TAF sites between 12z-16z. After 16z, a cold front will
sweep through the area from west to east, bringing strong northwest
winds, IFR to LIFR stratus, and scattered light showers, possibly
mixing with or changing over to snow in northwest and far northern
Missouri. Blowing snow with briefly reduced visibility is possible
across far northwest Missouri during the early afternoon hours, but
should stay north of all TAF sites.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY from 10 AM this morning to 9 PM CST this evening
FOR KSZ025-057-060-102>105.
WINTER WEATHER ADVISORY until 3 PM CST this afternoon FOR KSZ025-
102.
MO...WIND ADVISORY from 10 AM this morning to 9 PM CST this evening
FOR MOZ001>005-011>014-020>022-028>031-037>040-043>046-053-
054.
WINTER WEATHER ADVISORY until 3 PM CST this afternoon FOR
MOZ001>005-011>013-020.
WIND ADVISORY from 1 PM this afternoon to Midnight CST tonight
FOR MOZ006>008-015>017-023>025-032-033.
FLOOD WATCH through this afternoon FOR MOZ006>008-015>017-
023>025.
&&
$$
SHORT TERM...Leighton
LONG TERM...Hawblitzel
AVIATION...Laflin
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1156 PM CST Wed Feb 19 2014
.UPDATE:
Issued at 836 PM CST Wed Feb 19 2014
Having serious concerns that PoPs tonight are too high across
much of the area. Latest short range guidance keeps the vast
majority of the precip west and northwest of the STL Metro area
through the night. Not to say there couldn`t be some isolated to
scattered showers/t-storms just about anywhere after 06Z, but it
may not be worth the likely to categorical PoPs currently in the
forecast. The RAP focuses the low level jet over northeast MO into
central IL. This pushes the baroclinic zone north and while the
low level jet continues to be relatively strong across the entire
area, temperature/moisture advection becomes almost neutral for
the majority of the area. Will keep likely-categorical PoPs over
northern sections tonight near the baroclinic zone and the nose of
the low level jet. Further south, will start with just low
chance/slight chance and trend slowly upward through the night as
the shortwave approaches.
Carney
&&
.SHORT TERM: (Through Late Tonight)
Issued at 253 PM CST Wed Feb 19 2014
Main concerns tonight are the potential for localized flooding and
that a few thunderstorms could produce some hail near severe
limits. Showers and scattered thunderstorms have already begun to
develop over southeast Kansas this afternoon in a band of strong
moisture convergence that extends from the Central Plains into the
Mid South. The RAP shows this moisture convergence moving into
central Missouri by 00Z, which will then spreads northeast across the
CWA during the evening. Large scale ascent will increase across the
CWA tonight with the approach of the upper trough. At the same
time, the instability will also increase through the night as lapse
rates steepens with the approach of the upper trough in a highly
sheared environment. Overall coverage with any severe storms
capable of producing quarter size hail between 06-12Z is expected to
be limited in coverage over parts of central, northeast and east
central Missouri as well as adjacent sections of Illinois. A flood
watch will go into effect at midnight tonight where we expect
thunderstorms to move over the remaining snowpack. The ground is
frozen in these areas and streams and area rivers have had problems
with ice jams that could cause some localized flooding. The NMM and
NSSL WRF/GFS simulated reflectivity are similar to going forecast
which already have high chances for showers and thunderstorms this
evening across central and northeast Missouri and west central
Illinois, that then spreads southeast across the rest of the CWA
overnight.
Britt
.LONG TERM: (Thursday through Next Wednesday)
Issued at 253 PM CST Wed Feb 19 2014
Deepening surface low to lift northeast into southeastern Iowa by
18z Thursday, then into Great Lakes region by 06z Friday. In the
meantime, associated cold front to rapidly slide east through
forecast area with another round of showers and thunderstorms on
Thursday. Some of the storms could be strong with isolated severe
storms not out of the question but best chances will be east and
southeast of forecast area. Heaviest rains continue to be in an
axis from central through northeast MO and into west central IL.
Flood watch for portions of central/northeast MO and west central IL,
where there is still snow cover, to remain in effect until 00z
Friday. As for temperatures, will warm up into the mid 40s to
upper 60s by midday, then temperatures to fall through the
afternoon hours as cold front exits region. Another issue to deal
with will be the winds. Winds to pickup from the south ahead of
cold front then veer to the west and increase even more, between
15 and 25 mph with gusts near 35-40 mph at times. At this time no
wind advisory needed, but will need to keep an eye out on future
model runs to see if one will be needed.
Precipitation to move out of forecast area by 00z Friday with winds
gradually diminishing and skies clearing out. Lows will be near
normal in the mid 20s to low 30s.
On Friday, weak surface ridge to build in with winds becoming
southwesterly once again ahead of a weak cold front. Highs will
range from the upper 40s northeast to the upper 50s southwest.
As front slides through late Friday afternoon and Friday night,
energy to remain just north and northeast of forecast area, so
should see dry conditions. Did keep silent slight chance pops over
northeast MO and west central IL on Friday where some light
snow/light rain may be possible, but confidence is low right now.
By Saturday, surface ridge to build back in with cooler conditions
expected. Highs will only be in the upper 30s to mid 50s, but still
near normal for this time of year.
Beyond that, another weak shortwave to approach region Saturday
night, but confidence is low on any precipitation. So kept silent
slight chance pops for portions of forecast area for now. Lows
Saturday night will range from near 20 far north to the low 30s
far south. Dry and colder weather expected Sunday and Sunday night
with highs in the low 30s to mid 40s and lows in the upper teens
to mid 20s.
Next chance for precipitation will be Monday and Monday night,
though best chances will be over northern MO and northern half of
IL, so adjusted pops accordingly. With colder air moving in, the
precipitation will be in the form of light snow with this system.
Colder weather to persist through mid week with highs in the mid 20s
to low 40s each day and lows in the teens to low 20s.
Byrd
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1138 PM CST Wed Feb 19 2014
Specifics for KUIN: The two primary issues for this TAF period
are convective trends and wind trends. Thunderstorms were moving
through KUIN at TAF issuance and should persist for a few more
hours. Additional precipitation is expected ahead of a cold
front during the mid-morning hours, but the timing and placement
of storms remains somewhat uncertain. Wind speeds and gusts will
increase markedly after 18z with gusts exceeding 40 kts.
Specifics for KCOU: The two primary issues for this TAF period are
convective trends and wind trends. Showers with embedded
thunderstorms have developed farther north and east than
previously anticipated. I cannot rule out additional precipitation
overnight given upstream radar trends, but TSRA chances appear
higher after 12z ahead of an approaching cold front. Wind speeds
and gusts will increase markedly after 16-18z. Gusts may approach
40 kts at times.
Specifics for KSTL, KSUS, KCPS: The three primary issues for this
TAF period are convective trends, wind trends, and LLWS. Light
showers were ongoing at TAF issuance invof metro area TAF sites
near a lifting warm front, but this precipitation should only last
a couple of hours at most. A separate line of thunderstorms is
expected to develop ahead of a cold front during the morning or
early afternoon hours, but the timing and placement of the storms
remains somewhat uncertain. Wind speeds and gusts will increase
markedly after 18z. Gusts may exceed 40 kts. A strong southerly
LLJ will produce LLWS conditions through the early morning.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...FLOOD WATCH through Thursday afternoon FOR Audrain MO-Boone MO-
Knox MO-Lewis MO-Marion MO-Monroe MO-Pike MO-Ralls MO-
Shelby MO.
IL...FLOOD WATCH through Thursday afternoon FOR Adams IL-Brown IL-
Greene IL-Macoupin IL-Montgomery IL-Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
701 PM CST FRI FEB 21 2014
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 159 PM CST FRI FEB 21 2014
A BROAD CYCLONIC CIRCULATION IS INDICATED BY 12Z MODEL RUNS TO
REMAIN IN PLACE ACROSS MUCH OF THE NORTHERN HALF OF THE NATION
DURING THE PERIOD. THIS WILL RESULT IN TEMPERATURES TRENDING
COLDER THROUGH THE PERIOD WITH A CHANCE OF SNOW COMING INTO THE
AREA SUNDAY NIGHT INTO MONDAY.
A RATHER SHARP THERMAL GRADIENT WAS IN PLACE ACROSS THE REGION
AT 20Z WITH THE BOUNDARY STRETCHING FROM CENTRAL SOUTH DAKOTA
THROUGH NORTHEAST IOWA AND NORTHERN ILLINOIS. A WEAK SURFACE WAVE
IS FORECAST TO TRACK SOUTHEAST ALONG THIS GRADIENT TONIGHT AND
BE OVER CENTRAL ILLINOIS BY SATURDAY MORNING. SHORT RANGE MODELS
INDICATE SOME POTENTIAL FOR LIGHT SNOW NORTH OF THE WAVE LATE
TONIGHT. QPF LOOKS A BIT OVERDONE BY THE RAP COMPARED TO THE LONG
RANGE MODELS BUT HAVE INCLUDED A MENTION OF SCATTERED FLURRIES
FOR NORTHEAST NEBRASKA INTO SOUTHWEST IOWA AS THIS FEATURE MOVES
THROUGH TONIGHT.
THE COLD FRONT ASSOCIATED WITH THE WEAK LOW SINKS SOUTH INTO THE
SOUTHERN PLAINS AND LOWER OHIO VALLEY ON SATURDAY WITH COLD AIR
SLOWLY MOVING SOUTH BEHIND THE FRONT. SOME LIGHT SNOW BREAKS OUT
OVER THE WESTERN HIGH PLAINS SATURDAY AFTERNOON AS UPSLOPE FLOW
DEVELOPS AND CONTINUES SATURDAY NIGHT WITH SOME SPREAD TO THE EAST
INTO SOUTH CENTRAL NEBRASKA ASSOCIATED WITH WEAK ISENTROPIC
FORCING. HAVE BACKED OFF A BIT ON POPS FOR SOUTHWEST PORTION OF
THE FA FOR LATE SATURDAY NIGHT WITH SOME SLIGHT POPS INTO SUNDAY
MORNING AS BETTER FORCING IS EXPECTED TO REMAIN FURTHER WEST.
WEAK CYCLOGENESIS OCCURS OVER SOUTHEAST WYOMING ON SUNDAY AS AN
UPPER WAVE BEGINS TO DROP INTO THE NORTHERN ROCKIES. SOUTHERLY LOW
LEVEL FLOW DEVELOPS OVER THE CENTRAL PLAINS SUNDAY NIGHT IN
RESPONSE TO THIS DEVELOPMENT WITH A STRONG BAROCLINIC ZONE OVER
NORTHERN NEBRASKA BY MONDAY MORNING. A WIDESPREAD AREA OF SNOW
IS LIKELY ALONG AND NORTH OF THIS BOUNDARY SUNDAY NIGHT INTO
MONDAY MORNING. SNOW THEN SPREADS EAST ON MONDAY INTO NORTHERN
IOWA AS THE UPPER WAVE TRACKS TOWARD THE UPPER MIDWEST WITH THE
BETTER CHANCE OF SNOW EXPECTED NORTH OF INTERSTATE 80. MUCH COLDER
AIR WILL ALSO SURGE INTO THE FA BEHIND THIS WAVE ON MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 159 PM CST FRI FEB 21 2014
A COLD WINTER PATTERN WILL CONTINUE THROUGH THE PERIOD. ONE WEAK
WAVE WILL CONTINUE TO DRIFT SOUTHWARD AT THE BEGINNING OF THE
PERIOD...AND WITH H85 TEMPS WELL WITHIN THE DENDRITIC LAYER...COULD
SEE LINGERING FLURRIES MONDAY NIGHT...BUT LITTLE OR NO ACCUMULATION.
OTHERWISE...NORTHERLY FLOW WILL PERSIST TUESDAY AHEAD OF THE FIRST
SURGE OF EVEN COLDER AIR THAT ARRIVES TUESDAY NIGHT AND LINGERS
THROUGH WEDNESDAY...ALTHOUGH WESTERLY FLOW REDEVELOPS WEDNESDAY
WHICH SHOULD KEEP TEMPS IN THE 20S INSTEAD OF THE TEENS. A SECONDARY
SURGE OF COLDER TEMPS ARRIVES BY DAYBREAK THURSDAY AS SURFACE FLOW
AGAIN RETURNS TO THE NORTH/NORTHEAST. THIS SHOULD KEEP TEMPS IN THE
TEENS ON THURSDAY...BUT VERY LITTLE MOISTURE AVAILABLE SO NO CHANCE
OF PRECIP. A WEAK RETURN FLOW TRIES TO DEVELOP ON FRIDAY...BUT TEMPS
SHOULD REMAIN WELL BELOW NORMAL.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 700 PM CST FRI FEB 21 2014
EXPECT VFR CONDITIONS THROUGH THE PERIOD WITH ANY CEILINGS ABOVE
5000 FEET. A COLD FRONT WILL CONTINUE TO SETTLE SOUTHWARD ACROSS
THE AREA WITH LIGHT WINDS TENDING TO BECOME MORE NORTHERLY LATER
TONIGHT AND SATURDAY MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT
LONG TERM...DEWALD
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
630 PM EST FRI FEB 21 2014
.SYNOPSIS...A STRONG COLD FRONT WILL PUSH SOUTH AND EAST OF THE AREA THIS EVENING.
HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST TONIGHT AND SATURDAY...THEN DRIFT
EAST AND OFFSHORE ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...
QLCS CURRENTLY EXITING THE CWA AND WILL PLAN TO CANCEL TORNADO WATCH
23 FOR OUR COUNTIES WITH THE AFTERNOON PACKAGE. THE SYNOPTIC COLD
FRONT WILL MAKING ITS WAY THROUGH THE WESTERN PIEDMONT RIGHT NOW AND
WILL PUSH EAST THROUGH THE CWA BY AROUND 00Z. RH CROSS-SECTIONS
SUGGEST THERE MAY BE JUST ENOUGH SHALLOW MOISTURE CONVERGENCE ALONE
THE FRONT FOR A FEW ISOLATED SHOWERS. RECENT HRRR RUNS HAVEN`T BEEN
EXTREMELY CONSISTENT WITH THE COVERAGE OF ANY ADDITIONAL
SHOWERS...BUT WE WILL MAINTAIN JUST A SLIGHT CHANCE POP UNTIL HE
FRONT CLEARS THE AREA. OTHERWISE...MUCH DRIER AIR WILL FILTER INTO
THE AREA BEHIND THE FRONT ...WITH DEWPOINTS DROPPING INTO THE 20S.
HIGH PRESSURE RIDGING IN FROM THE WEST WILL ALLOW WESTERN AREAS TO
RADIATE THE BEST UNDER CLEAR SKIES...WITH LOWS DIPPING INTO THE MID
30S TO NEAR 40.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...
WELL SOUTH OF THE DEEP POLAR VORTEX OVER SOUTHEAST CANADA... THE
CAROLINAS WILL LIE UNDER THE INFLUENCE OF BROAD WESTERLY CYCLONIC
FLOW ALOFT. AT THE SURFACE...HIGH PRESSURE OF PACIFIC ORIGINS WILL
BRIEFLY BUILD OVER THE SOUTHEAST US ON SATURDAY... SHIFTING OFFSHORE
SATURDAY NIGHT WITH SOUTHERLY RETURN FLOW SUNDAY BEFORE A DRY
SURFACE COLD FRONT MOVES SOUTHEASTWARD THROUGH THE AREA SUNDAY
EVENING.
THIS WILL TRANSLATE INTO TO DRY CONDITIONS WITH CONTINUED SPRING-
LIKE TEMPERATURES INTO THE 60S ON SATURDAY...WITH SOME UPPER 60S TO
LOWER 70S ON SUNDAY. LOWS SATURDAY NIGHT IN THE 40S...COOLING OFF
INTO THE 30S BEHIND THE FRONT SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...
DRY CONDITIONS WILL CONTINUE INTO MONDAY...ALBEIT WITH COOLER-MORE
SEASONABLE TEMPERATURES AS A PROGRESSIVE NORTHERN STREAM HIGH OVER
THE CENTRAL US BUILDS EASTWARD INTO THE AREA.
TUESDAY THROUGH WEDNESDAY...AN EVEN STRONGER POLAR VORTEX DROPPING
SOUTHEASTWARD INTO SOUTHERN CANADA WILL RESULT IN A SIGNIFICANT
PATTERN CHANGE WITH A DEEP UPPER TROUGH FORECAST TO DEVELOP EAST OF
THE ROCKIES. WHILE THE OVERALL PATTERN IS HIGHLY AGREED UPON...THERE
IS STILL A FAIR AMOUNT OF UNCERTAINTY THATS LARGELY OWED TO THE
TIMING OF THE MID-LEVEL ENERGY EJECTING EASTWARD FROM THE CENTRAL
ROCKIES...AND TO A LESSER EXTENT...WEAK S/W IMPULSES OUT AHEAD OF
THE LEAD TROUGH THAT WILL EVENTUALLY RESULT IN SURFACE CYCLOGENESIS
ALONG A BAROCLINIC FRONTAL ZONE EXTENDING FROM THE GULF OF MEXICO TO
THE SE COAST. INCREASING RAIN CHANCES TUESDAY THROUGH
WEDNESDAY...WITH POPS/QPF DEPENDING ON TRACK/LOCATION OF COASTAL LOW
AND ALL LIQUID AT THIS TIME AS SIGNIFICANTLY COLDER AIR ARRIVES
THURSDAY THROUGH FRIDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 630 PM FRIDAY...
DRY HIGH PRESSURE BUILDING IN TONIGHT THROUGH SATURDAY. CLEAR SKIES
WITH LIGHT WEST WINDS OVERNIGHT BECOMING SOUTHWEST LESS THAN 10 MPH
TOMORROW.
OUTLOOK... A DRY COLD FRONT WILL MOVE THROUGH THE AREA SUNDAY
NIGHT...WITH ONLY A SMALL CHANCE OF SUB-VFR CONDITIONS. OTHERWISE...
VFR CONDITIONS ARE EXPECTED THROUGH EARLY TUESDAY WHEN ANOTHER
WEATHER SYSTEM IS EXPECTED TO IMPACT THE REGION.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...SMITH
SHORT TERM..CBL
LONG TERM...CBL
AVIATION...MLM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
244 PM EST THU FEB 20 2014
.SYNOPSIS...A WARM FRONT WILL MOVE NORTH OF THE AREA THIS
EVENING...WITH A STRONG COLD FRONT TO SWEEP EAST ACROSS THE AREA
FRIDAY. HIGH PRESSURE WILL BUILD INTO THE REGION FOR THE FIRST PART
OF THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 1045 AM THURSDAY...
REST OF TODAY: ONLY SMALL CHANGES NEEDED TO THE EXISTING FORECAST.
THE DEW POINT DISCONTINUITY IS VERY APPARENT WITH VALUES RANGING
FROM THE MID 30S IN THE FAR NORTH (WHERE SURFACE WINDS ARE MORE
EASTERLY OR ENE) TO LOWER 50S IN THE SOUTH (WITH MORE SOUTHEASTERLY
SURFACE WINDS). THIS WARM FRONTAL ZONE IS EXPECTED TO TRANSLATE
NORTHWARD TODAY... ALBEIT WITH LITTLE FANFARE AS INCOMING PRECIP
WATER (ACCORDING TO BLENDED TPW IMAGERY) REMAINS BELOW ONE INCH WITH
CONSIDERABLE DRY AIR THROUGH THE COLUMN (ACCORDING TO UPSTREAM
SOUNDINGS AND RAP FORECAST SOUNDINGS) AND AN ABSENCE OF FORCING FOR
ASCENT. CONVECTION-ALLOWING MODELS PICK UP ON THE PATCHY SPRINKLES
IN THE FAR NW CWA BUT THESE ARE EXPECTED TO DRY UP AND HEAD TO OUR
NORTH IN THE NEXT COUPLE OF HOURS... RESULTING IN A POP-FREE
AFTERNOON AREAWIDE. THE LATEST TEMP TRENDS... AS WELL AS THE
LINGERING LOWER CLOUDS IN THE NW CWA AND PLENTY OF FILTERED SUNSHINE
ELSEWHERE... SUPPORT HIGHS FROM 65 NW RANGING TO 76 SOUTHEAST.
(TODAY`S RECORD HIGH IS 75 AT RDU IN 1939... 74 IN GSO IN 1922...
AND 79 IN FAY IN 1956.) -GIH
TONIGHT...LOW LEVEL JET INCREASES IN RESPONSE TO THE APPROACH OF A
SIGNIFICANT S/W CROSSING THE UPPER MID WEST INTO THE GREAT LAKES.
WHILE SHOULD SEE SFC WINDS INCREASE TO AROUND 15 MPH AFTER
MIDNIGHT...DO NOT THINK THAT WE WILL BE ABLE TO TAP INTO THE
STRONGER WINDS JUST OFF THE SURFACE DUE TO A SFC BASED STABLE LAYER.
THE WELL MIXED AIR MASS ALONG WITH THE OVERCAST STRATUS DECK WILL
LEAD TO A MILD OVERNIGHT WITH TEMPS EITHER HOLDING STEADY OR SLOWLY
RISING. ANY SHOWERS THAT OCCUR SHOULD BE ISOLATED AND MAINLY
CONFINED TO THE YADKIN RIVER VALLEY. SHOULD SEE AN INCREASE IN
SHOWER COVERAGE HOWEVER TOWARD DAYBREAK IN THE FAR NW PIEDMONT AS A
STRONG COLD FRONT ASSOCIATED WITH THE GREAT LAKES S/W APPROACHES.
MIN TEMPS UPPER 50S TO AROUND 60. -WSS
FRIDAY DISCUSSION TO BE UPDATED SHORTLY...
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 240 PM THURSDAY...
VERY BROAD CYCLONIC FLOW ALOFT WILL ENCOMPASS MOST OF THE CONUS THIS
WEEKEND...TRANSITIONING TO A SPLIT FLOW PATTERN OVER THE WESTERN US
BY EARLY NEXT WEEK. IN THE WAKE OF THE DEPARTING COLD FRONT FRIDAY
NIGHT...A WELL MODIFIED HIGH PRESSURE WILL BUILD QUICKLY ACROSS THE
SOUTHEAST US ON SATURDAY AND THEN OFFSHORE BY SUNDAY....WITH THE
WEST-SOUTHWESTERLY FLOW ALOFT SUPPLYING PERIODS OF HIGH CLOUDS.
THIS WILL BRING SLIGHTLY COOLER BUT STILL ABOVE NORMAL HIGHS IN THE
60S FOR BOTH SATURDAY AND SUNDAY. ENERGY MOVING ACROSS THE DEEP
SOUTH ON SUNDAY WILL BRING MOISTURE BACK TOWARD THE CAROLINAS BY
LATE SUNDAY...BUT MOST MODELS CONTINUE TO INDICATE PRECIP WILL STAY
SOUTH OF NC...WITH A MOSTLY DRY COLD FRONT TO PUSH THROUGH FROM THE
NORTHWEST SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 240 PM THURSDAY...
A SPLIT FLOW PATTERN OVER THE WESTERN US WILL INHERENTLY LEAD TO
UNCERTAINTY IN THE FORECAST NEXT WEEK...THOUGH THERE IS GENERAL
MODEL AGREEMENT THAT THE LONGWAVE PATTERN WILL AMPLIFY AND A DEEPER
TROUGH WILL DEVELOP OVER THE EASTERN US. DURING THIS TIME...ENERGY
MOVING OUT OF A AN UPPER LOW OVER THE NORTHERN PACIFIC AND THROUGH
THE SOUTHERN STREAM WILL TRACK ACROSS THE SOUTHERN US...WHILE
SHORTWAVES ROTATE AROUND THE PERSISTENT UPPER LOW OVER EASTERN
CANADA. THE TEMPERATURE TREND FOR THE WEEK WILL BE BACK TO BELOW
NORMAL...THOUGH NOT NEARLY AS COLD AT OUR LATITUDE AS WE HAVE SEEN
OVER THE PAST FEW WEEKS. MODELS INDICATE ANOTHER ROUND OF MOISTURE
AND PRECIP SPREADING ACROSS THE SOUTHEAST US BY TUESDAY....WITH A
COLD FRONT TO PUSH THROUGH THE AREA BY WEDNESDAY. HOWEVER... WITHOUT
A STRONG SURFACE HIGH TO OUR NORTH...PTYPE IS EXPECTED TO BE ALL
LIQUID AT THIS TIME.
&&
.AVIATION /18Z WEDNESDAY THROUGH TUESDAY/...
AS OF 135 PM THURSDAY...
CURRENT VFR CONDITIONS ACROSS CENTRAL NC TERMINALS WILL PERSIST FOR
ANOTHER SEVERAL HOURS... LIKELY THROUGH SUNSET... AS A WARM FLOW
FROM THE SOUTHEAST AND SOUTH STEADILY STRENGTHENS TOWARD EVENING
(INT/GSO`S LIGHT WINDS FROM THE NE ARE EXPECTED TO SHIFT TO BE FROM
THE SE AND INCREASE TO NEAR 10 KTS AFTER 21Z). AFTER SUNSET... THIS
STRENGTHENING FLOW WILL BECOME UNIFORMLY FROM THE SOUTH (LIKELY 170-
200 DEGREES) INCREASING TO 14-19 KTS SUSTAINED WITH GUSTS TO 25-30
KTS POSSIBLE FROM MID EVENING ON THROUGH THE NIGHT AND INTO FRI
MORNING... AHEAD OF AN APPROACHING COLD FRONT. THIS INCREASING
SOUTHERLY FLOW WILL BRING A GOOD CHANCE OF LIFR CIGS OVERSPREADING
CENTRAL NC BETWEEN 02Z AND 05Z... ALTHOUGH THE WINDS SHOULD KEEP
VSBYS ABOVE 6SM. THESE LIFR CIGS ARE EXPECTED TO PERSIST THROUGH
SUNRISE FRI. THE COLD FRONT WILL CROSS CENTRAL NC DURING THE MORNING
THROUGH EARLY AFTERNOON... INT/GSO AROUND 14Z-15Z... RDU AROUND 16Z-
17Z... AND RWI/FAY LIKELY NOT UNTIL AFTER 18Z. WIDESPREAD SHOWERS
AND PERHAPS A STORM OR TWO WILL PRECEDE THE FRONT BY AN HOUR OR
TWO... LASTING A COUPLE OF HOURS. STRONG WINDS WILL SWING AROUND TO
SW AND WEST AND DIMINISH IMMEDIATELY BEHIND THE FRONT... WITH CIGS
RISING TO MVFR.
LOOKING BEYOND 18Z FRI: AS NOTED ABOVE... CIGS ARE EXPECTED TO RISE
BEHIND THE FRONT... TO VFR AT INT/GSO SOON AFTER 18Z... AT RDU SOON
AFTER 20Z... AND TO RWI/FAY SOON AFTER 22Z... WITH A SHIFT IN WINDS
TO WESTERLY UNDER 12 KTS. SURFACE HIGH PRESSURE WILL BUILD IN LATE
FRI THROUGH SUN BRINGING VFR CONDITIONS AND LIGHT WINDS DURING THIS
TIME FRAME. A MAINLY DRY COLD FRONT PASSAGE SUNDAY EVENING/NIGHT MAY
BRING BRIEF SUB-VFR CONDITIONS DURING THIS PERIOD... RETURNING TO
VFR MONDAY. INCREASING ONSHORE FLOW TUE MAY BRING SUB-VFR CONDITIONS
ONCE AGAIN LATE TUE. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JB
NEAR TERM...HARTFIELD/WSS
SHORT TERM..SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
135 PM EST THU FEB 20 2014
.SYNOPSIS...HIGH PRESSURE OVER THE MID ATLANTIC WILL MOVE OFFSHORE
TODAY. A WARM FRONT WILL MOVE NORTH THROUGH THE REGION LATE THIS
AFTERNOON. A STRONG COLD FRONT WILL SWEEP EAST ACROSS THE AREA
FRIDAY. HIGH PRESSURE WILL BUILD INTO THE REGION FOR THE FIRST PART
OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM THURSDAY...
REST OF TODAY: ONLY SMALL CHANGES NEEDED TO THE EXISTING FORECAST.
THE DEW POINT DISCONTINUITY IS VERY APPARENT WITH VALUES RANGING
FROM THE MID 30S IN THE FAR NORTH (WHERE SURFACE WINDS ARE MORE
EASTERLY OR ENE) TO LOWER 50S IN THE SOUTH (WITH MORE SOUTHEASTERLY
SURFACE WINDS). THIS WARM FRONTAL ZONE IS EXPECTED TO TRANSLATE
NORTHWARD TODAY... ALBEIT WITH LITTLE FANFARE AS INCOMING PRECIP
WATER (ACCORDING TO BLENDED TPW IMAGERY) REMAINS BELOW ONE INCH WITH
CONSIDERABLE DRY AIR THROUGH THE COLUMN (ACCORDING TO UPSTREAM
SOUNDINGS AND RAP FORECAST SOUNDINGS) AND AN ABSENCE OF FORCING FOR
ASCENT. CONVECTION-ALLOWING MODELS PICK UP ON THE PATCHY SPRINKLES
IN THE FAR NW CWA BUT THESE ARE EXPECTED TO DRY UP AND HEAD TO OUR
NORTH IN THE NEXT COUPLE OF HOURS... RESULTING IN A POP-FREE
AFTERNOON AREAWIDE. THE LATEST TEMP TRENDS... AS WELL AS THE
LINGERING LOWER CLOUDS IN THE NW CWA AND PLENTY OF FILTERED SUNSHINE
ELSEWHERE... SUPPORT HIGHS FROM 65 NW RANGING TO 76 SOUTHEAST.
(TODAY`S RECORD HIGH IS 75 AT RDU IN 1939... 74 IN GSO IN 1922...
AND 79 IN FAY IN 1956.) -GIH
TONIGHT...LOW LEVEL JET INCREASES IN RESPONSE TO THE APPROACH OF A
SIGNIFICANT S/W CROSSING THE UPPER MID WEST INTO THE GREAT LAKES.
WHILE SHOULD SEE SFC WINDS INCREASE TO AROUND 15 MPH AFTER
MIDNIGHT...DO NOT THINK THAT WE WILL BE ABLE TO TAP INTO THE
STRONGER WINDS JUST OFF THE SURFACE DUE TO A SFC BASED STABLE LAYER.
THE WELL MIXED AIR MASS ALONG WITH THE OVERCAST STRATUS DECK WILL
LEAD TO A MILD OVERNIGHT WITH TEMPS EITHER HOLDING STEADY OR SLOWLY
RISING. ANY SHOWERS THAT OCCUR SHOULD BE ISOLATED AND MAINLY
CONFINED TO THE YADKIN RIVER VALLEY. SHOULD SEE AN INCREASE IN
SHOWER COVERAGE HOWEVER TOWARD DAYBREAK IN THE FAR NW PIEDMONT AS A
STRONG COLD FRONT ASSOCIATED WITH THE GREAT LAKES S/W APPROACHES.
MIN TEMPS UPPER 50S TO AROUND 60. -WSS
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 315 AM THURSDAY...
FRIDAY...SFC COLD FRONT PROJECTED TO MARCH EAST ACROSS CENTRAL NC
DURING THE MORNING THROUGH THE EARLY AFTERNOON HOURS. CONVERGENCE
ALONG THE BOUNDARY ALONG WITH A MOIST AIR MASS SHOULD RESULT IN A
BAND OF HEAVY SHOWERS. WILL SEE POTENTIAL FOR STRONG GUSTY SFC WINDS
TO OCCUR AHEAD OF THE BOUNDARY (NEAR 30KTS). EXPECT MAIN BAND OF
SHOWERS TO LIE ALONG THE U.S. 1 CORRIDOR BY LATE MORNING/MIND
DAY...AND INTO THE COASTAL PLAIN BY EARLY AFTERNOON. CONVECTIVE
PARAMETERS SUGGEST A HIGH SHEAR/LOW CAPE ENVIRONMENT WILL EXISTS
ALONG AND EAST OF HIGHWAY 1. THIS WILL LEAD TO THE DEVELOPMENT OF A
FEW THUNDERSTORMS IN THE LINE OF HEAVY SHOWERS. THIS MAY LEAD TO AN
INCREASE THREAT FOR DAMAGING WIND GUSTS AS THE SHOWERS AND STORMS
PROGRESS EAST INTO THE COASTAL PLAIN AND INTERACT WITH THE LOW LEVEL
JET. LOW LEVEL HELICITY VALUES SUPPORTIVE OF SOME WEAK ROTATION BUT
THE LACK OF A WELL-DEFINED SFC CIRCULATION IN OUR VICINITY WILL
LIMIT TORNADIC THREAT.
MAIN MID-UPPER LEVEL SUPPORT SWEEPS THROUGH THE COASTAL PLAIN BY MID
AFTERNOON...LEADING TO RAPID DISSIPATION/EXIT OF THE SHOWERS AND
STORMS. DOWNSLOPE FLOW IN THE WAKE OF THE SFC BOUNDARY COUPLED WITH
DECENT SUBSIDENCE IN THE WAKE OF THE MID-UPPER LEVEL TROUGH WILL
LEAD TO CLEARING SKIES IN THE WESTERN PIEDMONT BY EARLY
AFTERNOON...AND INTO THE TRIANGLE AREA AND NORTHEAST PIEDMONT BY MID-
LATE AFTERNOON.
MAX TEMPS FRIDAY DEPENDENT ON ARRIVAL TIME OF SHOWERS AND POSSIBLY
CLEARING IN THE AFTERNOON. MODEL GUIDANCE IN REASONABLE AGREEMENT
AND GENERALLY FOLLOWED. MAX TEMPS MID 60S NW TO LOWER 70S FAR EAST.
COOLER DRIER AIR WILL OVERSPREAD CENTRAL NC FRIDAY NIGHT AS HIGH
PRESSURE OVER THE LOWER MS VALLEY BUILDS EAST-NE. SFC WINDS WILL
SUBSIDE AND UNDER MAINLY CLEAR SKIES...SHOULD SEE TEMPS COOL BACK
INTO THE 30S BY EARLY SATURDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 306 AM THURSDAY...
WITH THE FRONT OFFSHORE... HIGH PRESSURE WILL BRIEFLY BUILD ACROSS
THE AREA SATURDAY. A SIGNIFICANTLY DRIER AIRMASS ACROSS THE AREA
WILL BRING MOSTLY SUNNY SKIES. ON SUNDAY... WITH BROAD HIGH PRESSURE
OVER THE ATLANTIC AND A COLD FRONT APPROACHING FROM THE WEST... LOW
LEVEL SOUTHWEST FLOW WILL ENCOMPASS THE AREA... AND LOW LEVEL
THICKNESSES WILL RISE A OVER SATURDAY... PROVIDING SLIGHTLY WARMER
TEMPERATURES.
BROAD TROUGHING WILL BEGIN TO RE-ESTABLISH ITSELF ACROSS THE EAST
COAST TO BEGIN THE WEEK. A DRY COLD FRONT WILL MOVE THROUGH THE AREA
EARLY MONDAY... AND TEMPERATURES WILL FALL BACK A FEW DEGREES BELOW
NORMAL THROUGH THE FIRST PART OF THE WEEK. ANOTHER COLD FRONT LOOKS
LIKELY TO CROSS THE AREA WEDNESDAY... DROPPING TEMPERATURES AGAIN BY
A FEW DEGREES. GLOBAL MODELS DEVELOP A SURFACE WAVE ALONG THE
BAROCLINIC ZONE NEAR THE COAST. WILL CONTINUE WITH SLIGHT CHANCE
POPS THE LATTER HALF OF TUESDAY INTO EARLY WEDNESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH TUESDAY/...
AS OF 135 PM THURSDAY...
CURRENT VFR CONDITIONS ACROSS CENTRAL NC TERMINALS WILL PERSIST FOR
ANOTHER SEVERAL HOURS... LIKELY THROUGH SUNSET... AS A WARM FLOW
FROM THE SOUTHEAST AND SOUTH STEADILY STRENGTHENS TOWARD EVENING
(INT/GSO`S LIGHT WINDS FROM THE NE ARE EXPECTED TO SHIFT TO BE FROM
THE SE AND INCREASE TO NEAR 10 KTS AFTER 21Z). AFTER SUNSET... THIS
STRENGTHENING FLOW WILL BECOME UNIFORMLY FROM THE SOUTH (LIKELY 170-
200 DEGREES) INCREASING TO 14-19 KTS SUSTAINED WITH GUSTS TO 25-30
KTS POSSIBLE FROM MID EVENING ON THROUGH THE NIGHT AND INTO FRI
MORNING... AHEAD OF AN APPROACHING COLD FRONT. THIS INCREASING
SOUTHERLY FLOW WILL BRING A GOOD CHANCE OF LIFR CIGS OVERSPREADING
CENTRAL NC BETWEEN 02Z AND 05Z... ALTHOUGH THE WINDS SHOULD KEEP
VSBYS ABOVE 6SM. THESE LIFR CIGS ARE EXPECTED TO PERSIST THROUGH
SUNRISE FRI. THE COLD FRONT WILL CROSS CENTRAL NC DURING THE MORNING
THROUGH EARLY AFTERNOON... INT/GSO AROUND 14Z-15Z... RDU AROUND 16Z-
17Z... AND RWI/FAY LIKELY NOT UNTIL AFTER 18Z. WIDESPREAD SHOWERS
AND PERHAPS A STORM OR TWO WILL PRECEDE THE FRONT BY AN HOUR OR
TWO... LASTING A COUPLE OF HOURS. STRONG WINDS WILL SWING AROUND TO
SW AND WEST AND DIMINISH IMMEDIATELY BEHIND THE FRONT... WITH CIGS
RISING TO MVFR.
LOOKING BEYOND 18Z FRI: AS NOTED ABOVE... CIGS ARE EXPECTED TO RISE
BEHIND THE FRONT... TO VFR AT INT/GSO SOON AFTER 18Z... AT RDU SOON
AFTER 20Z... AND TO RWI/FAY SOON AFTER 22Z... WITH A SHIFT IN WINDS
TO WESTERLY UNDER 12 KTS. SURFACE HIGH PRESSURE WILL BUILD IN LATE
FRI THROUGH SUN BRINGING VFR CONDITIONS AND LIGHT WINDS DURING THIS
TIME FRAME. A MAINLY DRY COLD FRONT PASSAGE SUNDAY EVENING/NIGHT MAY
BRING BRIEF SUB-VFR CONDITIONS DURING THIS PERIOD... RETURNING TO
VFR MONDAY. INCREASING ONSHORE FLOW TUE MAY BRING SUB-VFR CONDITIONS
ONCE AGAIN LATE TUE. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JB
NEAR TERM...HARTFIELD/WSS
SHORT TERM..WSS
LONG TERM...SEC
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1045 AM EST THU FEB 20 2014
.SYNOPSIS...HIGH PRESSURE OVER THE MID ATLANTIC WILL MOVE OFFSHORE
TODAY. A WARM FRONT WILL MOVE NORTH THROUGH THE REGION LATE THIS
AFTERNOON. A STRONG COLD FRONT WILL SWEEP EAST ACROSS THE AREA
FRIDAY. HIGH PRESSURE WILL BUILD INTO THE REGION FOR THE FIRST PART
OF THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM THURSDAY...
REST OF TODAY: ONLY SMALL CHANGES NEEDED TO THE EXISTING FORECAST.
THE DEW POINT DISCONTINUITY IS VERY APPARENT WITH VALUES RANGING
FROM THE MID 30S IN THE FAR NORTH (WHERE SURFACE WINDS ARE MORE
EASTERLY OR ENE) TO LOWER 50S IN THE SOUTH (WITH MORE SOUTHEASTERLY
SURFACE WINDS). THIS WARM FRONTAL ZONE IS EXPECTED TO TRANSLATE
NORTHWARD TODAY... ALBEIT WITH LITTLE FANFARE AS INCOMING PRECIP
WATER (ACCORDING TO BLENDED TPW IMAGERY) REMAINS BELOW ONE INCH WITH
CONSIDERABLE DRY AIR THROUGH THE COLUMN (ACCORDING TO UPSTREAM
SOUNDINGS AND RAP FORECAST SOUNDINGS) AND AN ABSENCE OF FORCING FOR
ASCENT. CONVECTION-ALLOWING MODELS PICK UP ON THE PATCHY SPRINKLES
IN THE FAR NW CWA BUT THESE ARE EXPECTED TO DRY UP AND HEAD TO OUR
NORTH IN THE NEXT COUPLE OF HOURS... RESULTING IN A POP-FREE
AFTERNOON AREAWIDE. THE LATEST TEMP TRENDS... AS WELL AS THE
LINGERING LOWER CLOUDS IN THE NW CWA AND PLENTY OF FILTERED SUNSHINE
ELSEWHERE... SUPPORT HIGHS FROM 65 NW RANGING TO 76 SOUTHEAST.
(TODAY`S RECORD HIGH IS 75 AT RDU IN 1939... 74 IN GSO IN 1922...
AND 79 IN FAY IN 1956.) -GIH
TONIGHT...LOW LEVEL JET INCREASES IN RESPONSE TO THE APPROACH OF A
SIGNIFICANT S/W CROSSING THE UPPER MID WEST INTO THE GREAT LAKES.
WHILE SHOULD SEE SFC WINDS INCREASE TO AROUND 15 MPH AFTER
MIDNIGHT...DO NOT THINK THAT WE WILL BE ABLE TO TAP INTO THE
STRONGER WINDS JUST OFF THE SURFACE DUE TO A SFC BASED STABLE LAYER.
THE WELL MIXED AIR MASS ALONG WITH THE OVERCAST STRATUS DECK WILL
LEAD TO A MILD OVERNIGHT WITH TEMPS EITHER HOLDING STEADY OR SLOWLY
RISING. ANY SHOWERS THAT OCCUR SHOULD BE ISOLATED AND MAINLY
CONFINED TO THE YADKIN RIVER VALLEY. SHOULD SEE AN INCREASE IN
SHOWER COVERAGE HOWEVER TOWARD DAYBREAK IN THE FAR NW PIEDMONT AS A
STRONG COLD FRONT ASSOCIATED WITH THE GREAT LAKES S/W APPROACHES.
MIN TEMPS UPPER 50S TO AROUND 60. -WSS
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 315 AM THURSDAY...
FRIDAY...SFC COLD FRONT PROJECTED TO MARCH EAST ACROSS CENTRAL NC
DURING THE MORNING THROUGH THE EARLY AFTERNOON HOURS. CONVERGENCE
ALONG THE BOUNDARY ALONG WITH A MOIST AIR MASS SHOULD RESULT IN A
BAND OF HEAVY SHOWERS. WILL SEE POTENTIAL FOR STRONG GUSTY SFC WINDS
TO OCCUR AHEAD OF THE BOUNDARY (NEAR 30KTS). EXPECT MAIN BAND OF
SHOWERS TO LIE ALONG THE U.S. 1 CORRIDOR BY LATE MORNING/MIND
DAY...AND INTO THE COASTAL PLAIN BY EARLY AFTERNOON. CONVECTIVE
PARAMETERS SUGGEST A HIGH SHEAR/LOW CAPE ENVIRONMENT WILL EXISTS
ALONG AND EAST OF HIGHWAY 1. THIS WILL LEAD TO THE DEVELOPMENT OF A
FEW THUNDERSTORMS IN THE LINE OF HEAVY SHOWERS. THIS MAY LEAD TO AN
INCREASE THREAT FOR DAMAGING WIND GUSTS AS THE SHOWERS AND STORMS
PROGRESS EAST INTO THE COASTAL PLAIN AND INTERACT WITH THE LOW LEVEL
JET. LOW LEVEL HELICITY VALUES SUPPORTIVE OF SOME WEAK ROTATION BUT
THE LACK OF A WELL-DEFINED SFC CIRCULATION IN OUR VICINITY WILL
LIMIT TORNADIC THREAT.
MAIN MID-UPPER LEVEL SUPPORT SWEEPS THROUGH THE COASTAL PLAIN BY MID
AFTERNOON...LEADING TO RAPID DISSIPATION/EXIT OF THE SHOWERS AND
STORMS. DOWNSLOPE FLOW IN THE WAKE OF THE SFC BOUNDARY COUPLED WITH
DECENT SUBSIDENCE IN THE WAKE OF THE MID-UPPER LEVEL TROUGH WILL
LEAD TO CLEARING SKIES IN THE WESTERN PIEDMONT BY EARLY
AFTERNOON...AND INTO THE TRIANGLE AREA AND NORTHEAST PIEDMONT BY MID-
LATE AFTERNOON.
MAX TEMPS FRIDAY DEPENDENT ON ARRIVAL TIME OF SHOWERS AND POSSIBLY
CLEARING IN THE AFTERNOON. MODEL GUIDANCE IN REASONABLE AGREEMENT
AND GENERALLY FOLLOWED. MAX TEMPS MID 60S NW TO LOWER 70S FAR EAST.
COOLER DRIER AIR WILL OVERSPREAD CENTRAL NC FRIDAY NIGHT AS HIGH
PRESSURE OVER THE LOWER MS VALLEY BUILDS EAST-NE. SFC WINDS WILL
SUBSIDE AND UNDER MAINLY CLEAR SKIES...SHOULD SEE TEMPS COOL BACK
INTO THE 30S BY EARLY SATURDAY.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 306 AM THURSDAY...
WITH THE FRONT OFFSHORE... HIGH PRESSURE WILL BRIEFLY BUILD ACROSS
THE AREA SATURDAY. A SIGNIFICANTLY DRIER AIRMASS ACROSS THE AREA
WILL BRING MOSTLY SUNNY SKIES. ON SUNDAY... WITH BROAD HIGH PRESSURE
OVER THE ATLANTIC AND A COLD FRONT APPROACHING FROM THE WEST... LOW
LEVEL SOUTHWEST FLOW WILL ENCOMPASS THE AREA... AND LOW LEVEL
THICKNESSES WILL RISE A OVER SATURDAY... PROVIDING SLIGHTLY WARMER
TEMPERATURES.
BROAD TROUGHING WILL BEGIN TO RE-ESTABLISH ITSELF ACROSS THE EAST
COAST TO BEGIN THE WEEK. A DRY COLD FRONT WILL MOVE THROUGH THE AREA
EARLY MONDAY... AND TEMPERATURES WILL FALL BACK A FEW DEGREES BELOW
NORMAL THROUGH THE FIRST PART OF THE WEEK. ANOTHER COLD FRONT LOOKS
LIKELY TO CROSS THE AREA WEDNESDAY... DROPPING TEMPERATURES AGAIN BY
A FEW DEGREES. GLOBAL MODELS DEVELOP A SURFACE WAVE ALONG THE
BAROCLINIC ZONE NEAR THE COAST. WILL CONTINUE WITH SLIGHT CHANCE
POPS THE LATTER HALF OF TUESDAY INTO EARLY WEDNESDAY.
&&
.AVIATION /12Z WEDNESDAY THROUGH MONDAY/...
AS OF 708 AM THURSDAY...
ASIDE FROM POCKETS OF MVFR VISIBILITY DUE TO FOG...VFR CONDITIONS
COVER CENTRAL NC EARLY THIS MORNING. STILL A CHANCE THAT LOW STRATUS
WILL DEVELOP AROUND 14Z AND PERSIST UNTIL 18Z WITH IFR/LOW END MVFR
CEILINGS. IF STRATUS DOES NOT DEVELOP...VFR CONDITIONS WILL PERSIST
THROUGH THE AFTERNOON THROUGH THE EARLY EVENING HOURS. SOUTHEASTERLY
SFC WINDS WILL BECOME A LITTLE BREEZY....OCCASIONALLY GUSTING BETWEEN
16 AND 20 KTS.
LOW CLOUDS WILL RETURN LATE TONIGHT (AFTER 06Z FRIDAY) AS SLY FLOW
AHEAD OF A STRONG COLD FRONT PULLS WARM MOIST AIR INTO CENTRAL NC.
EXPECT WIDESPREAD IFR/LIFR CEILINGS LATE TONIGHT INTO EARLY FRIDAY
MORNING. THE APPROACHING COLD FRONT WILL INCREASE THE THREAT FOR
SHOWERS IN THE KINT AND KGSO VICINITIES BETWEEN 09Z-12Z FRIDAY.
THE COLD FRONT WILL PROGRESS EAST ACROSS THE PIEDMONT FRIDAY MORNING
AND THE SANDHILLS AND COASTAL PLAIN IN THE EARLY AFTERNOON.
WIDESPREAD SHOWERS AND A FEW THUNDERSTORMS WILL ACCOMPANY THE FRONT.
A FEW THUNDERSTORM WIND GUST MAY REACH AS HIGH AS 40-50KTS...MAINLY
IN VICINITY OF KRDU...KFAY AND KRWI. IN ADDITION...EXPECT IFR/MVFR
CEILINGS.
AVIATION WEATHER CONDITIONS WILL IMPROVE WEST-TO-EAST AS WESTERLY
WINDS BEHIND THE DEPARTING ADVECT DRIER MORE STABLE AIR INTO CENTRAL
NC. EXPECT VFR CONDITIONS IN THE WESTERN PIEDMONT BY MID
AFTERNOON...AND INTO THE COASTAL PLAIN AND SANDHILLS BY EARLY
EVENING. WITH HIGH PRESSURE IN CONTROL OF OUR WEATHER THIS
WEEKEND...EXPECT VFR CONDITIONS THROUGH SUNDAY. SLY FLOW ON THE BACK
SIDE OF THE RETREATING HIGH PRESSURE SYSTEM WILL LIKELY INCREASE THE
THREAT FOR SUB VFR CONDITIONS SUNDAY NIGHT INTO MONDAY MORNING.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JB
NEAR TERM...HARTFIELD/WSS
SHORT TERM..WSS
LONG TERM...SEC
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1259 PM EST THU FEB 20 2014
.SYNOPSIS...
WARM FRONT LIFTS NORTH TODAY. STRONG COLD FRONT TONIGHT. ANOTHER
SYSTEM MOVES THROUGH ON SUNDAY. SNOW MONDAY NIGHT INTO TUESDAY.
WINTER CONTINUES IN NEW WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAD TO ADJUST THE POPS WITH THE ONGOING CONVECTION. STILL PLAYING
THE THUNDER CARD ALTHOUGH IT APPEARS THE CELLS ARE TRANSFORMING
INTO LARGER AREA OF SHOWERS. SHOULD EXIT TO THE NORTH BY 17Z.
PREVIOUS DISCUSSION...
A WARM FRONT LIFTS NORTH THIS MORNING WITH BETTER CHANCES FOR RAIN
SHOWERS ACROSS SOUTHEAST OH...NORTHEAST KY...AND PORTIONS OF WV
ALONG THE OH RIVER. INCREASED POPS LIFTING WITH THE WARM FRONT TO
LIKELY...DIMINISHING AS SHOWERS MOVE NORTH.
MODELS INDICATE WIND FLOW WILL INCREASE FROM THE SOUTHWEST TO
60-70 KNOTS AT H85 AHEAD OF A COLD FRONT EXPECTED TO PASS TONIGHT.
SOME OF THESE STRONG WINDS WILL MOST LIKELY BE FELT OVER THE
HIGHER TERRAIN...AND ALONG SHOWERS WHICH WILL BE CAPABLE TO MIX
DOWN THESE WINDS. HOWEVER...IN THE WARM SECTOR IT WILL STRUGGLE
TO MIX DOWN PER UP GLIDING ASPECT EVIDENT IN ISENTROPIC SURFACES.
THE FRONT SHOULD PRODUCE A QUICK 0.5 INCHES OF RAIN...PERHAPS MORE
ALONG THE STRONGER STORM OR SHOWER.
HOLD OFF ON ISSUING A WIND ADVISORY AS THE EVENT LOOKS MARGINAL
ATTM. THE BEST WINDS 40 TO 50 KNOTS...OCCUR IN THE WARM SECTOR AS
EXPLAINED BEFORE. A WIND ADVISORY COULD BE NECESSARY ALONG OR
BEHIND THE FRONT. OR THE EVENT COULD BE TREATED WITH SPS AND
SEVERE STORM WARNINGS IF NEEDED. WILL LET DAY SHIFT TO DECIDE HOW
TO HANDLE THIS EVENT.
THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS TONIGHT WITH
DAMAGING WINDS BEING THE MAIN THREAT. SMALL HAIL CAN NOT BE RULED
OUT OF THE QUESTIONS AS FREEZING LEVELS WILL BE AROUND 9-10 KFT.
SNOW MELT HAVE CAUSE WATERS IN SMALL STREAMS TO RISE. FLOODING WAS
KEPT IN THE HAZARDOUS WEATHER OUTLOOK.
MINOR TWEAKS TO PREVIOUS TEMPERATURES. BLENDED THE RUC13 WITH MOST
GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
STRONG SYSTEM EXITING THE AREA AT THE OUTSET OF THE SHORT-TERM
PERIOD 12Z FRI. CONSENSUS OF NWP OUTPUT SLOWING THE FRONT JUST A BIT
OVERNIGHT FROM PREV RUNS...WITH THE VARIOUS MODELS HAVING THE SFC FRONT
LOCATED PRETTY MUCH ON OUR EASTERN CWA BORDER OF POCAHONTAS AND
RANDOLPH COUNTIES AT 12Z FRI. ELEVATED FRONT OF COURSE THEN IS A BIT
SLOWER AS WELL AND CROSSES THE HIGH PEAKS BTWN 12Z-15Z FRI MORNING
WITH A RAPID COOL DOWN FOR LOCATIONS SUCH AS SNO FROM THE LOW 40S AT
12Z FRI TO THE UPPER 20S/LOW 30S BY 15Z FRI. REFLECTED THIS IN THE
HOURLY TEMP TRACE FRIDAY MORNING. ALSO SLOWED DOWN PRECIP EXIT JUST
A BIT WITH IT...WITH LATEST NAM12 AND GFS BUFKIT SOUNDINGS STILL
INDICATING NEARLY COMPLETE SATURATION UP TO 600-500MB AT 15Z FRI.
THIS PRECIP WILL BE ALL RAIN INITIALLY ON THE HIGHEST PEAKS BUT WILL
QUICKLY CHANGE TO SNOW FOR A BRIEF WINDOW OF 1-3 HOURS AS THE PRECIP
MOVES OUT OF THE AREA. MAY GET A QUICK HALF-INCH TO PERHAPS AN INCH
OF SNOW FRI MID-MORNING AS THIS SYSTEM WINDS DOWN...BUT AGAIN THIS
SHOULD BE CONFINED TO ELEVATIONS MAINLY ABOVE 3KFT.
ONCE THE LAST OF THE PRECIP MOVES OUT...THE REMAINDER OF FRIDAY WILL
SEE IMPROVING CONDITIONS WITH MOSTLY SUNNY TO PARTLY CLOUDY SKIES BY
THE AFTERNOON HOURS WITH TEMPS INTO THE UPPER 40S TO LOWER 50S FOR
THE LOWLANDS. MAY SEE A BIT MORE STRATO-CU HANGING ON ACROSS THE
NORTHERN ZONES DURING THE AFTERNOON HOURS WITH A BIT MORE LLVL
MOISTURE TO WORK WITH. IT WILL CONTINUE TO BE A VERY WINDY DAY
ACROSS THE AREA WITH STRONG SFC LOW PRESSURE LOCATED OVER THE
NORTHERN GREAT LAKES. FOR THE LOWLANDS...EXPECT GENERAL 20G30KTS FOR
MUCH OF THE DAY...WHILE THE HIGHEST PEAKS OF THE EASTERN MOUNTAINS
SEE POTENTIALLY 40-45KT GUSTS. A 50KT GUST WOULD NOT BE IMPOSSIBLE
TO REALIZE AT THE HIGHEST ELEVATIONS...PARTICULARLY FOR AN HOUR OR
SO IMMEDIATELY FOLLOWING THE FRONTAL PASSAGE.
FRIDAY EVENING THE SFC LOW OVER THE GREAT LAKES CONTINUES TO SLOWLY
PULL AWAY WITH SFC HIGH PRESSURE LOCATED NEAR THE SMOKY MOUNTAIN
REGION BY 12Z SAT. DRY WEATHER WILL CONTINUE AND THE WORST OF THE
WINDY CONDITIONS WILL QUICKLY DISSIPATE NEAR AND AFTER SUNSET WITH
THE LOSS OF ANY MIXING. WITH A DECENT PRESSURE GRADIENT OVER THE
AREA WILL STILL MAINTAIN A PUFF OF WIND IT APPEARS. ALSO WILL SEE
SOME WARM ADVECTION MAKING INTO THE AREA BY AND AFTER 06Z SAT.
INHERITED MIN TEMPS FROM PREV SHIFT GENERALLY LOOK GOOD...WITH MINOR
ADJUSTMENTS.
SATURDAY WILL BE ANOTHER PLEASANT DAY. SFC HIGH PRESSURE SLOWLY
PULLS EAST WITH A RETURN S/SW FLOW SETTING UP BY THE AFTERNOON.
BUMPED UP MAX TEMPS FOR SATURDAY A GOOD 3-5 DEGREES AREA-WIDE WITH
925MB TEMPS PROGGED AROUND 8-9C...EXPECT TEMPS TO REBOUND INTO THE
MID 50S NORTHERN LOWLANDS AND UPPER 50S TO 60 CENTRAL AND SOUTHERN
LOWLANDS. IT WILL STILL BE ON THE BREEZY SIDE BUT NOT NEARLY AS
GUSTY AS FRIDAY...SO IT WILL PROBABLY FEEL MUCH NICER THAN FRIDAY.
SATURDAY NIGHT...INHERITED MINS THE LOW/MID 30S LOWLANDS STILL
APPEAR ON TRACK AGAIN...WITH JUST A FEW ADJUSTMENTS. A WEAK
DISTURBANCE IN THE NEAR ZONAL FLOW MAY DRAG A WEAK COLD FRONT INTO
THE NORTHERN ZONES BY END OF PERIOD AND THUS WILL CONTINUE THE
SLIGHT TO LOW CHANCE POPS FROM PREV SHIFT IN THESE AREAS.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MODELS SHOWING A WEAK SYSTEM SYSTEM MOVING THROUGH SATURDAY NIGHT
INTO SUNDAY. TYPE OF PRECIPITATION IS QUESTIONABLE BASED ON TIMING
AND HOW MUCH RADIATION OCCURS SATURDAY NIGHT IN ADVANCE OF THE
SYSTEM. USED A BLEND OF THE ECMWF AND GFS.
FOR MONDAY THROUGH WEDNESDAY...USED A BLEND OF THE GEFS ENSEMBLE
MEAN AND ECMWF ENSEMBLE MEAN. THIS KEEPS A TROUGH OVER THE EASTERN
UNITED STATES CREATING A WINTER WEATHER SITUATION WHERE VARIOUS
WAVES COULD CREATE SNOW AT TIMES. THE TIMING OF THE WAVES AND
INTENSITY OF THE COLD AIR REMAIN IN QUESTION HOWEVER...AS VARIOUS
ENSEMBLE MEMBERS VARY CONSIDERABLY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AREA NOW IN THE WARM SECTOR AS WARM FRONTAL SHOWERS HAVE LIFTED
NORTH INTO PENNSYLVANIA AND CEILINGS GENERALLY ABOVE 7KFT. WITH THAT
SAID...CONCERNS TURN TO WIND FOR THE REMAINDER OF TODAY THROUGH
00Z FRIDAY.
MAINLY SOUTHERLY FLOW WILL CONTINUE TO BUILD TODAY SUSTAINED
15-20KTS WITH GUSTS TO 30KTS. THERE WILL BE A SLIGHT SOUTHEASTERLY
COMPONENT TO THIS FLOW AT FIRST AND WILL THEN VEER TO THE SOUTH
AHEAD OF THE EXPECTED COLD FRONT AND CONVECTION AFTER 00Z.
LOW LEVEL JET AT 850MB INCREASES OUT OF THE SOUTH SOUTHWEST WITH
THE APPROACH OF THE COLD FRONT. NAM FORECAST MODEL GIVING 60-70KTS
POSSIBLE WITH THIS FEATURE. CAN EXPECT SOME OF THIS MOMENTUM TO
MIX DOWN WITH SHOWERS AND THUNDERSTORMS...SO 40-50KT GUSTS IN THE
CONVECTION ITSELF ARE LIKELY.
EXPECTING A LINE OF CONVECTION TO FORM OUT AHEAD OF THE COLD FRONT
WHICH SHOULD BE A QUICK MOVER THROUGH THE CWA. FELT IT APPROPRIATE
TO CARRY IFR VISIBILITIES IN TSRA FOR ONE HOUR DURATION. TIMING
WILL BE CRITICAL TO THE FORECAST HOWEVER.
EXPECT CEILINGS TO RECOVER FAIRLY QUICKLY BEHIND THE FRONT WITH A
DRY SLOT WORKING IN. WINDS WILL VEER TO THE WEST SOUTHWEST BEHIND
THE FRONT WITH GUSTS IN THE 30-35KT RANGE POSSIBLE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF CONVECTION LINE AND FRONT MAY VARY
BY AN HOUR OR TWO. THIS COULD HAVE LARGE IMPACTS ON THE TAF GIVEN
THE SHORT DURATION OF THE CONVECTION.
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 H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H M
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H L L L L L L
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z FRIDAY...
IFR POSSIBLE IN SNOW LATE MONDAY NIGHT AND TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ/26
SHORT TERM...50
LONG TERM...RPY
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
937 AM EST THU FEB 20 2014
.SYNOPSIS...
WARM FRONT LIFTS NORTH TODAY. STRONG COLD FRONT TONIGHT. ANOTHER
SYSTEM MOVES THROUGH ON SUNDAY. SNOW MONDAY NIGHT INTO TUESDAY.
WINTER CONTINUES IN NEW WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
HAD TO ADJUST THE POPS WITH THE ONGOING CONVECTION. STILL PLAYING
THE THUNDER CARD ALTHOUGH IT APPEARS THE CELLS ARE TRANSFORMING
INTO LARGER AREA OF SHOWERS. SHOULD EXIT TO THE NORTH BY 17Z.
PREVIOUS DISCUSSION...
A WARM FRONT LIFTS NORTH THIS MORNING WITH BETTER CHANCES FOR RAIN
SHOWERS ACROSS SOUTHEAST OH...NORTHEAST KY...AND PORTIONS OF WV
ALONG THE OH RIVER. INCREASED POPS LIFTING WITH THE WARM FRONT TO
LIKELY...DIMINISHING AS SHOWERS MOVE NORTH.
MODELS INDICATE WIND FLOW WILL INCREASE FROM THE SOUTHWEST TO
60-70 KNOTS AT H85 AHEAD OF A COLD FRONT EXPECTED TO PASS TONIGHT.
SOME OF THESE STRONG WINDS WILL MOST LIKELY BE FELT OVER THE
HIGHER TERRAIN...AND ALONG SHOWERS WHICH WILL BE CAPABLE TO MIX
DOWN THESE WINDS. HOWEVER...IN THE WARM SECTOR IT WILL STRUGGLE
TO MIX DOWN PER UP GLIDING ASPECT EVIDENT IN ISENTROPIC SURFACES.
THE FRONT SHOULD PRODUCE A QUICK 0.5 INCHES OF RAIN...PERHAPS MORE
ALONG THE STRONGER STORM OR SHOWER.
HOLD OFF ON ISSUING A WIND ADVISORY AS THE EVENT LOOKS MARGINAL
ATTM. THE BEST WINDS 40 TO 50 KNOTS...OCCUR IN THE WARM SECTOR AS
EXPLAINED BEFORE. A WIND ADVISORY COULD BE NECESSARY ALONG OR
BEHIND THE FRONT. OR THE EVENT COULD BE TREATED WITH SPS AND
SEVERE STORM WARNINGS IF NEEDED. WILL LET DAY SHIFT TO DECIDE HOW
TO HANDLE THIS EVENT.
THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS TONIGHT WITH
DAMAGING WINDS BEING THE MAIN THREAT. SMALL HAIL CAN NOT BE RULED
OUT OF THE QUESTIONS AS FREEZING LEVELS WILL BE AROUND 9-10 KFT.
SNOW MELT HAVE CAUSE WATERS IN SMALL STREAMS TO RISE. FLOODING WAS
KEPT IN THE HAZARDOUS WEATHER OUTLOOK.
MINOR TWEAKS TO PREVIOUS TEMPERATURES. BLENDED THE RUC13 WITH MOST
GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
STRONG SYSTEM EXITING THE AREA AT THE OUTSET OF THE SHORT-TERM
PERIOD 12Z FRI. CONSENSUS OF NWP OUTPUT SLOWING THE FRONT JUST A BIT
OVERNIGHT FROM PREV RUNS...WITH THE VARIOUS MODELS HAVING THE SFC FRONT
LOCATED PRETTY MUCH ON OUR EASTERN CWA BORDER OF POCAHONTAS AND
RANDOLPH COUNTIES AT 12Z FRI. ELEVATED FRONT OF COURSE THEN IS A BIT
SLOWER AS WELL AND CROSSES THE HIGH PEAKS BTWN 12Z-15Z FRI MORNING
WITH A RAPID COOL DOWN FOR LOCATIONS SUCH AS SNO FROM THE LOW 40S AT
12Z FRI TO THE UPPER 20S/LOW 30S BY 15Z FRI. REFLECTED THIS IN THE
HOURLY TEMP TRACE FRIDAY MORNING. ALSO SLOWED DOWN PRECIP EXIT JUST
A BIT WITH IT...WITH LATEST NAM12 AND GFS BUFKIT SOUNDINGS STILL
INDICATING NEARLY COMPLETE SATURATION UP TO 600-500MB AT 15Z FRI.
THIS PRECIP WILL BE ALL RAIN INITIALLY ON THE HIGHEST PEAKS BUT WILL
QUICKLY CHANGE TO SNOW FOR A BRIEF WINDOW OF 1-3 HOURS AS THE PRECIP
MOVES OUT OF THE AREA. MAY GET A QUICK HALF-INCH TO PERHAPS AN INCH
OF SNOW FRI MID-MORNING AS THIS SYSTEM WINDS DOWN...BUT AGAIN THIS
SHOULD BE CONFINED TO ELEVATIONS MAINLY ABOVE 3KFT.
ONCE THE LAST OF THE PRECIP MOVES OUT...THE REMAINDER OF FRIDAY WILL
SEE IMPROVING CONDITIONS WITH MOSTLY SUNNY TO PARTLY CLOUDY SKIES BY
THE AFTERNOON HOURS WITH TEMPS INTO THE UPPER 40S TO LOWER 50S FOR
THE LOWLANDS. MAY SEE A BIT MORE STRATO-CU HANGING ON ACROSS THE
NORTHERN ZONES DURING THE AFTERNOON HOURS WITH A BIT MORE LLVL
MOISTURE TO WORK WITH. IT WILL CONTINUE TO BE A VERY WINDY DAY
ACROSS THE AREA WITH STRONG SFC LOW PRESSURE LOCATED OVER THE
NORTHERN GREAT LAKES. FOR THE LOWLANDS...EXPECT GENERAL 20G30KTS FOR
MUCH OF THE DAY...WHILE THE HIGHEST PEAKS OF THE EASTERN MOUNTAINS
SEE POTENTIALLY 40-45KT GUSTS. A 50KT GUST WOULD NOT BE IMPOSSIBLE
TO REALIZE AT THE HIGHEST ELEVATIONS...PARTICULARLY FOR AN HOUR OR
SO IMMEDIATELY FOLLOWING THE FRONTAL PASSAGE.
FRIDAY EVENING THE SFC LOW OVER THE GREAT LAKES CONTINUES TO SLOWLY
PULL AWAY WITH SFC HIGH PRESSURE LOCATED NEAR THE SMOKY MOUNTAIN
REGION BY 12Z SAT. DRY WEATHER WILL CONTINUE AND THE WORST OF THE
WINDY CONDITIONS WILL QUICKLY DISSIPATE NEAR AND AFTER SUNSET WITH
THE LOSS OF ANY MIXING. WITH A DECENT PRESSURE GRADIENT OVER THE
AREA WILL STILL MAINTAIN A PUFF OF WIND IT APPEARS. ALSO WILL SEE
SOME WARM ADVECTION MAKING INTO THE AREA BY AND AFTER 06Z SAT.
INHERITED MIN TEMPS FROM PREV SHIFT GENERALLY LOOK GOOD...WITH MINOR
ADJUSTMENTS.
SATURDAY WILL BE ANOTHER PLEASANT DAY. SFC HIGH PRESSURE SLOWLY
PULLS EAST WITH A RETURN S/SW FLOW SETTING UP BY THE AFTERNOON.
BUMPED UP MAX TEMPS FOR SATURDAY A GOOD 3-5 DEGREES AREA-WIDE WITH
925MB TEMPS PROGGED AROUND 8-9C...EXPECT TEMPS TO REBOUND INTO THE
MID 50S NORTHERN LOWLANDS AND UPPER 50S TO 60 CENTRAL AND SOUTHERN
LOWLANDS. IT WILL STILL BE ON THE BREEZY SIDE BUT NOT NEARLY AS
GUSTY AS FRIDAY...SO IT WILL PROBABLY FEEL MUCH NICER THAN FRIDAY.
SATURDAY NIGHT...INHERITED MINS THE LOW/MID 30S LOWLANDS STILL
APPEAR ON TRACK AGAIN...WITH JUST A FEW ADJUSTMENTS. A WEAK
DISTURBANCE IN THE NEAR ZONAL FLOW MAY DRAG A WEAK COLD FRONT INTO
THE NORTHERN ZONES BY END OF PERIOD AND THUS WILL CONTINUE THE
SLIGHT TO LOW CHANCE POPS FROM PREV SHIFT IN THESE AREAS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MODELS SHOWING A WEAK SYSTEM SYSTEM MOVING THROUGH SATURDAY NIGHT
INTO SUNDAY. TYPE OF PRECIPITATION IS QUESTIONABLE BASED ON TIMING
AND HOW MUCH RADIATION OCCURS SATURDAY NIGHT IN ADVANCE OF THE
SYSTEM. USED A BLEND OF THE ECMWF AND GFS.
FOR MONDAY THROUGH WEDNESDAY...USED A BLEND OF THE GEFS ENSEMBLE
MEAN AND ECMWF ENSEMBLE MEAN. THIS KEEPS A TROUGH OVER THE EASTERN
UNITED STATES CREATING A WINTER WEATHER SITUATION WHERE VARIOUS
WAVES COULD CREATE SNOW AT TIMES. THE TIMING OF THE WAVES AND
INTENSITY OF THE COLD AIR REMAIN IN QUESTION HOWEVER...AS VARIOUS
ENSEMBLE MEMBERS VARY CONSIDERABLY.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS WILL CONTINUE AT MOST SITES...EXCEPT MVFR UNDER
LIGHT FOG AT PKB AND VICINITY.
CALM WINDS WILL GRADUALLY INCREASE FROM THE SOUTHEAST AT THE
SURFACE AND SOUTHWEST ALOFT BY MID MORNING...LASTING INTO THE
EVENING HOURS.
CEILINGS WILL REMAIN AT LEAST MVFR FOR THE MOST PART AFTER FROPA
EXCEPT IFR ALONG THE EASTERN MOUNTAINS BY FRIDAY 12Z.
LOW LEVEL WIND SHEAR WILL BE POSSIBLE LATER THIS AFTERNOON AND
TONIGHT IF LOWER ATMOSPHERE DECOUPLES. WINDS ALOFT WILL INCREASE
EVEN THIS EVENING FOR FEW HOURS UNTIL DIURNAL MIXING STOPS. MODELS
SHOW H85 WINDS INCREASING TO 50 KNOTS BY 18Z TODAY...AND EVEN 70
KNOTS BY 06Z TONIGHT...AHEAD OF THE FRONT.
EXPECT SOME CONVECTION DEVELOPING AHEAD OF THE COLD FRONT THIS
AFTERNOON AND EVENING...WITH THE MAIN CONVECTIVE SQUALL LINE WITH
FAST MOVING SHOWERS/EMBEDDED THUNDERSTORM REACHING SOUTHEAST OHIO
AROUND MIDNIGHT.
CONVECTION AHEAD OF FROPA SHOULD REACH SOUTHEAST OH BY 06-09Z
FRIDAY TO SPREAD IFR CEILINGS ALONG THEIR PATH.
THERE IS A SLIGHT RISK FOR DAMAGING WINDS WITH STORMS WITH THIS
FROPA. THE WINDY SHOWERS OR STORMS WILL SPREAD QUICKLY EAST. THIS
WILL BE AN HIGH SHEAR...LOW CAPE ENVIRONMENT...WITH PW AROUND 1
INCH.
HAVE CLOUDS THICKENING FROM 12 TO 18Z TODAY FROM SOUTH TO NORTH
DOWN TO 3500 FEET...EXCEPT 2500 FEET EXTREME NORTHWEST PORTIONS OF
OUR CWA. CEILINGS DETERIORATE WITH THE PROXIMITY OF FROPA
OVERNIGHT TONIGHT DOWN TO AROUND 2000 FEET UNDER RAIN SHOWERS.
BRIEF PERIODS OF IFR POSSIBLE ALONG HEAVIEST SHOWERS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: MORE SHOWER COVERAGE ASSOCIATED WITH THE WARM
FRONT A BIT FURTHER EAST THAN FORECAST. TIMING COVERAGE OF LOWER
CLOUDS DEVELOPING ON EASTERN SLOPES 18Z THURSDAY TO 00Z FRIDAY
COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 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 M H H H H H H H H H H H
HTS CONSISTENCY M H H M M H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H M M M H H H H H L L
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z FRIDAY...
IFR POSSIBLE TONIGHT IN FAST MOVING AND GUSTY SHOWERS...AND
POSSIBLY BRIEF THUNDERSTORMS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ/26
SHORT TERM...50
LONG TERM...RPY
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
537 AM EST THU FEB 20 2014
.SYNOPSIS...
WARM FRONT LIFTS NORTH TODAY. STRONG COLD FRONT TONIGHT. ANOTHER
SYSTEM MOVES THROUGH ON SUNDAY. SNOW MONDAY NIGHT INTO TUESDAY.
WINTER CONTINUES IN NEW WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT LIFTS NORTH THIS MORNING WITH BETTER CHANCES FOR RAIN
SHOWERS ACROSS SOUTHEAST OH...NORTHEAST KY...AND PORTIONS OF WV
ALONG THE OH RIVER. INCREASED POPS LIFTING WITH THE WARM FRONT TO
LIKELY...DIMINISHING AS SHOWERS MOVE NORTH.
MODELS INDICATE WIND FLOW WILL INCREASE FROM THE SOUTHWEST TO
60-70 KNOTS AT H85 AHEAD OF A COLD FRONT EXPECTED TO PASS TONIGHT.
SOME OF THESE STRONG WINDS WILL MOST LIKELY BE FELT OVER THE
HIGHER TERRAIN...AND ALONG SHOWERS WHICH WILL BE CAPABLE TO MIX
DOWN THESE WINDS. HOWEVER...IN THE WARM SECTOR IT WILL STRUGGLE
TO MIX DOWN PER UP GLIDING ASPECT EVIDENT IN ISENTROPIC SURFACES.
THE FRONT SHOULD PRODUCE A QUICK 0.5 INCHES OF RAIN...PERHAPS MORE
ALONG THE STRONGER STORM OR SHOWER.
HOLD OFF ON ISSUING A WIND ADVISORY AS THE EVENT LOOKS MARGINAL
ATTM. THE BEST WINDS 40 TO 50 KNOTS...OCCUR IN THE WARM SECTOR AS
EXPLAINED BEFORE. A WIND ADVISORY COULD BE NECESSARY ALONG OR
BEHIND THE FRONT. OR THE EVENT COULD BE TREATED WITH SPS AND
SEVERE STORM WARNINGS IF NEEDED. WILL LET DAY SHIFT TO DECIDE HOW
TO HANDLE THIS EVENT.
THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS TONIGHT WITH
DAMAGING WINDS BEING THE MAIN THREAT. SMALL HAIL CAN NOT BE RULED
OUT OF THE QUESTIONS AS FREEZING LEVELS WILL BE AROUND 9-10 KFT.
SNOW MELT HAVE CAUSE WATERS IN SMALL STREAMS TO RISE. FLOODING WAS
KEPT IN THE HAZARDOUS WEATHER OUTLOOK.
MINOR TWEAKS TO PREVIOUS TEMPERATURES. BLENDED THE RUC13 WITH MOST
GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
STRONG SYSTEM EXITING THE AREA AT THE OUTSET OF THE SHORT-TERM
PERIOD 12Z FRI. CONSENSUS OF NWP OUTPUT SLOWING THE FRONT JUST A BIT
OVERNIGHT FROM PREV RUNS...WITH THE VARIOUS MODELS HAVING THE SFC FRONT
LOCATED PRETTY MUCH ON OUR EASTERN CWA BORDER OF POCAHONTAS AND
RANDOLPH COUNTIES AT 12Z FRI. ELEVATED FRONT OF COURSE THEN IS A BIT
SLOWER AS WELL AND CROSSES THE HIGH PEAKS BTWN 12Z-15Z FRI MORNING
WITH A RAPID COOL DOWN FOR LOCATIONS SUCH AS SNO FROM THE LOW 40S AT
12Z FRI TO THE UPPER 20S/LOW 30S BY 15Z FRI. REFLECTED THIS IN THE
HOURLY TEMP TRACE FRIDAY MORNING. ALSO SLOWED DOWN PRECIP EXIT JUST
A BIT WITH IT...WITH LATEST NAM12 AND GFS BUFKIT SOUNDINGS STILL
INDICATING NEARLY COMPLETE SATURATION UP TO 600-500MB AT 15Z FRI.
THIS PRECIP WILL BE ALL RAIN INITIALLY ON THE HIGHEST PEAKS BUT WILL
QUICKLY CHANGE TO SNOW FOR A BRIEF WINDOW OF 1-3 HOURS AS THE PRECIP
MOVES OUT OF THE AREA. MAY GET A QUICK HALF-INCH TO PERHAPS AN INCH
OF SNOW FRI MID-MORNING AS THIS SYSTEM WINDS DOWN...BUT AGAIN THIS
SHOULD BE CONFINED TO ELEVATIONS MAINLY ABOVE 3KFT.
ONCE THE LAST OF THE PRECIP MOVES OUT...THE REMAINDER OF FRIDAY WILL
SEE IMPROVING CONDITIONS WITH MOSTLY SUNNY TO PARTLY CLOUDY SKIES BY
THE AFTERNOON HOURS WITH TEMPS INTO THE UPPER 40S TO LOWER 50S FOR
THE LOWLANDS. MAY SEE A BIT MORE STRATO-CU HANGING ON ACROSS THE
NORTHERN ZONES DURING THE AFTERNOON HOURS WITH A BIT MORE LLVL
MOISTURE TO WORK WITH. IT WILL CONTINUE TO BE A VERY WINDY DAY
ACROSS THE AREA WITH STRONG SFC LOW PRESSURE LOCATED OVER THE
NORTHERN GREAT LAKES. FOR THE LOWLANDS...EXPECT GENERAL 20G30KTS FOR
MUCH OF THE DAY...WHILE THE HIGHEST PEAKS OF THE EASTERN MOUNTAINS
SEE POTENTIALLY 40-45KT GUSTS. A 50KT GUST WOULD NOT BE IMPOSSIBLE
TO REALIZE AT THE HIGHEST ELEVATIONS...PARTICULARLY FOR AN HOUR OR
SO IMMEDIATELY FOLLOWING THE FRONTAL PASSAGE.
FRIDAY EVENING THE SFC LOW OVER THE GREAT LAKES CONTINUES TO SLOWLY
PULL AWAY WITH SFC HIGH PRESSURE LOCATED NEAR THE SMOKY MOUNTAIN
REGION BY 12Z SAT. DRY WEATHER WILL CONTINUE AND THE WORST OF THE
WINDY CONDITIONS WILL QUICKLY DISSIPATE NEAR AND AFTER SUNSET WITH
THE LOSS OF ANY MIXING. WITH A DECENT PRESSURE GRADIENT OVER THE
AREA WILL STILL MAINTAIN A PUFF OF WIND IT APPEARS. ALSO WILL SEE
SOME WARM ADVECTION MAKING INTO THE AREA BY AND AFTER 06Z SAT.
INHERITED MIN TEMPS FROM PREV SHIFT GENERALLY LOOK GOOD...WITH MINOR
ADJUSTMENTS.
SATURDAY WILL BE ANOTHER PLEASANT DAY. SFC HIGH PRESSURE SLOWLY
PULLS EAST WITH A RETURN S/SW FLOW SETTING UP BY THE AFTERNOON.
BUMPED UP MAX TEMPS FOR SATURDAY A GOOD 3-5 DEGREES AREA-WIDE WITH
925MB TEMPS PROGGED AROUND 8-9C...EXPECT TEMPS TO REBOUND INTO THE
MID 50S NORTHERN LOWLANDS AND UPPER 50S TO 60 CENTRAL AND SOUTHERN
LOWLANDS. IT WILL STILL BE ON THE BREEZY SIDE BUT NOT NEARLY AS
GUSTY AS FRIDAY...SO IT WILL PROBABLY FEEL MUCH NICER THAN FRIDAY.
SATURDAY NIGHT...INHERITED MINS THE LOW/MID 30S LOWLANDS STILL
APPEAR ON TRACK AGAIN...WITH JUST A FEW ADJUSTMENTS. A WEAK
DISTURBANCE IN THE NEAR ZONAL FLOW MAY DRAG A WEAK COLD FRONT INTO
THE NORTHERN ZONES BY END OF PERIOD AND THUS WILL CONTINUE THE
SLIGHT TO LOW CHANCE POPS FROM PREV SHIFT IN THESE AREAS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MODELS SHOWING A WEAK SYSTEM SYSTEM MOVING THROUGH SATURDAY NIGHT
INTO SUNDAY. TYPE OF PRECIPITATION IS QUESTIONABLE BASED ON TIMING
AND HOW MUCH RADIATION OCCURS SATURDAY NIGHT IN ADVANCE OF THE
SYSTEM. USED A BLEND OF THE ECMWF AND GFS.
FOR MONDAY THROUGH WEDNESDAY...USED A BLEND OF THE GEFS ENSEMBLE
MEAN AND ECMWF ENSEMBLE MEAN. THIS KEEPS A TROUGH OVER THE EASTERN
UNITED STATES CREATING A WINTER WEATHER SITUATION WHERE VARIOUS
WAVES COULD CREATE SNOW AT TIMES. THE TIMING OF THE WAVES AND
INTENSITY OF THE COLD AIR REMAIN IN QUESTION HOWEVER...AS VARIOUS
ENSEMBLE MEMBERS VARY CONSIDERABLY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS WILL CONTINUE AT MOST SITES...EXCEPT MVFR UNDER
LIGHT FOG AT PKB AND VICINITY.
CALM WINDS WILL GRADUALLY INCREASE FROM THE SOUTHEAST AT THE
SURFACE AND SOUTHWEST ALOFT BY MID MORNING...LASTING INTO THE
EVENING HOURS.
CEILINGS WILL REMAIN AT LEAST MVFR FOR THE MOST PART AFTER FROPA
EXCEPT IFR ALONG THE EASTERN MOUNTAINS BY FRIDAY 12Z.
LOW LEVEL WIND SHEAR WILL BE POSSIBLE LATER THIS AFTERNOON AND
TONIGHT IF LOWER ATMOSPHERE DECOUPLES. WINDS ALOFT WILL INCREASE
EVEN THIS EVENING FOR FEW HOURS UNTIL DIURNAL MIXING STOPS. MODELS
SHOW H85 WINDS INCREASING TO 50 KNOTS BY 18Z TODAY...AND EVEN 70
KNOTS BY 06Z TONIGHT...AHEAD OF THE FRONT.
EXPECT SOME CONVECTION DEVELOPING AHEAD OF THE COLD FRONT THIS
AFTERNOON AND EVENING...WITH THE MAIN CONVECTIVE SQUALL LINE WITH
FAST MOVING SHOWERS/EMBEDDED THUNDERSTORM REACHING SOUTHEAST OHIO
AROUND MIDNIGHT.
CONVECTION AHEAD OF FROPA SHOULD REACH SOUTHEAST OH BY 06-09Z
FRIDAY TO SPREAD IFR CEILINGS ALONG THEIR PATH.
THERE IS A SLIGHT RISK FOR DAMAGING WINDS WITH STORMS WITH THIS
FROPA. THE WINDY SHOWERS OR STORMS WILL SPREAD QUICKLY EAST. THIS
WILL BE AN HIGH SHEAR...LOW CAPE ENVIRONMENT...WITH PW AROUND 1
INCH.
HAVE CLOUDS THICKENING FROM 12 TO 18Z TODAY FROM SOUTH TO NORTH
DOWN TO 3500 FEET...EXCEPT 2500 FEET EXTREME NORTHWEST PORTIONS OF
OUR CWA. CEILINGS DETERIORATE WITH THE PROXIMITY OF FROPA
OVERNIGHT TONIGHT DOWN TO AROUND 2000 FEET UNDER RAIN SHOWERS.
BRIEF PERIODS OF IFR POSSIBLE ALONG HEAVIEST SHOWERS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: MORE SHOWER COVERAGE ASSOCIATED WITH THE WARM
FRONT A BIT FURTHER EAST THAN FORECAST. TIMING COVERAGE OF LOWER
CLOUDS DEVELOPING ON EASTERN SLOPES 18Z THURSDAY TO 00Z FRIDAY
COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 02/20/14
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H M M H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY L L L H H H H H M M M H
CKB CONSISTENCY L H H H H H H H H H H H
AFTER 12Z FRIDAY...
IFR POSSIBLE TONIGHT IN FAST MOVING AND GUSTY SHOWERS...AND
POSSIBLY BRIEF THUNDERSTORMS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...RPY
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
418 AM EST THU FEB 20 2014
.SYNOPSIS...
WARM FRONT LIFTS NORTH TODAY. STRONG COLD FRONT TONIGHT. ANOTHER
SYSTEM MOVES THROUGH ON SUNDAY. SNOW MONDAY NIGHT INTO TUESDAY.
WINTER CONTINUES IN NEW WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WARM FRONT LIFTS NORTH THIS MORNING WITH BETTER CHANCES FOR RAIN
SHOWERS ACROSS SOUTHEAST OH...NORTHEAST KY...AND PORTIONS OF WV
ALONG THE OH RIVER. INCREASED POPS LIFTING WITH THE WARM FRONT TO
LIKELY...DIMINISHING AS SHOWERS MOVE NORTH.
MODELS INDICATE WIND FLOW WILL INCREASE FROM THE SOUTHWEST TO
60-70 KNOTS AT H85 AHEAD OF A COLD FRONT EXPECTED TO PASS TONIGHT.
SOME OF THESE STRONG WINDS WILL MOST LIKELY BE FELT OVER THE
HIGHER TERRAIN...AND ALONG SHOWERS WHICH WILL BE CAPABLE TO MIX
DOWN THESE WINDS. HOWEVER...IN THE WARM SECTOR IT WILL STRUGGLE
TO MIX DOWN PER UP GLIDING ASPECT EVIDENT IN ISENTROPIC SURFACES.
THE FRONT SHOULD PRODUCE A QUICK 0.5 INCHES OF RAIN...PERHAPS MORE
ALONG THE STRONGER STORM OR SHOWER.
HOLD OFF ON ISSUING A WIND ADVISORY AS THE EVENT LOOKS MARGINAL
ATTM. THE BEST WINDS 40 TO 50 KNOTS...OCCUR IN THE WARM SECTOR AS
EXPLAINED BEFORE. A WIND ADVISORY COULD BE NECESSARY ALONG OR
BEHIND THE FRONT. OR THE EVENT COULD BE TREATED WITH SPS AND
SEVERE STORM WARNINGS IF NEEDED. WILL LET DAY SHIFT TO DECIDE HOW
TO HANDLE THIS EVENT.
THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS TONIGHT WITH
DAMAGING WINDS BEING THE MAIN THREAT. SMALL HAIL CAN NOT BE RULED
OUT OF THE QUESTIONS AS FREEZING LEVELS WILL BE AROUND 9-10 KFT.
SNOW MELT HAVE CAUSE WATERS IN SMALL STREAMS TO RISE. FLOODING WAS
KEPT IN THE HAZARDOUS WEATHER OUTLOOK.
MINOR TWEAKS TO PREVIOUS TEMPERATURES. BLENDED THE RUC13 WITH MOST
GUIDANCE FOR TEMPERATURES THROUGH THE PERIOD.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
STRONG SYSTEM EXITING THE AREA AT THE OUTSET OF THE SHORT-TERM
PERIOD 12Z FRI. CONSENSUS OF NWP OUTPUT SLOWING THE FRONT JUST A BIT
OVERNIGHT FROM PREV RUNS...WITH THE VARIOUS MODELS HAVING THE SFC FRONT
LOCATED PRETTY MUCH ON OUR EASTERN CWA BORDER OF POCAHONTAS AND
RANDOLPH COUNTIES AT 12Z FRI. ELEVATED FRONT OF COURSE THEN IS A BIT
SLOWER AS WELL AND CROSSES THE HIGH PEAKS BTWN 12Z-15Z FRI MORNING
WITH A RAPID COOL DOWN FOR LOCATIONS SUCH AS SNO FROM THE LOW 40S AT
12Z FRI TO THE UPPER 20S/LOW 30S BY 15Z FRI. REFLECTED THIS IN THE
HOURLY TEMP TRACE FRIDAY MORNING. ALSO SLOWED DOWN PRECIP EXIT JUST
A BIT WITH IT...WITH LATEST NAM12 AND GFS BUFKIT SOUNDINGS STILL
INDICATING NEARLY COMPLETE SATURATION UP TO 600-500MB AT 15Z FRI.
THIS PRECIP WILL BE ALL RAIN INITIALLY ON THE HIGHEST PEAKS BUT WILL
QUICKLY CHANGE TO SNOW FOR A BRIEF WINDOW OF 1-3 HOURS AS THE PRECIP
MOVES OUT OF THE AREA. MAY GET A QUICK HALF-INCH TO PERHAPS AN INCH
OF SNOW FRI MID-MORNING AS THIS SYSTEM WINDS DOWN...BUT AGAIN THIS
SHOULD BE CONFINED TO ELEVATIONS MAINLY ABOVE 3KFT.
ONCE THE LAST OF THE PRECIP MOVES OUT...THE REMAINDER OF FRIDAY WILL
SEE IMPROVING CONDITIONS WITH MOSTLY SUNNY TO PARTLY CLOUDY SKIES BY
THE AFTERNOON HOURS WITH TEMPS INTO THE UPPER 40S TO LOWER 50S FOR
THE LOWLANDS. MAY SEE A BIT MORE STRATO-CU HANGING ON ACROSS THE
NORTHERN ZONES DURING THE AFTERNOON HOURS WITH A BIT MORE LLVL
MOISTURE TO WORK WITH. IT WILL CONTINUE TO BE A VERY WINDY DAY
ACROSS THE AREA WITH STRONG SFC LOW PRESSURE LOCATED OVER THE
NORTHERN GREAT LAKES. FOR THE LOWLANDS...EXPECT GENERAL 20G30KTS FOR
MUCH OF THE DAY...WHILE THE HIGHEST PEAKS OF THE EASTERN MOUNTAINS
SEE POTENTIALLY 40-45KT GUSTS. A 50KT GUST WOULD NOT BE IMPOSSIBLE
TO REALIZE AT THE HIGHEST ELEVATIONS...PARTICULARLY FOR AN HOUR OR
SO IMMEDIATELY FOLLOWING THE FRONTAL PASSAGE.
FRIDAY EVENING THE SFC LOW OVER THE GREAT LAKES CONTINUES TO SLOWLY
PULL AWAY WITH SFC HIGH PRESSURE LOCATED NEAR THE SMOKY MOUNTAIN
REGION BY 12Z SAT. DRY WEATHER WILL CONTINUE AND THE WORST OF THE
WINDY CONDITIONS WILL QUICKLY DISSIPATE NEAR AND AFTER SUNSET WITH
THE LOSS OF ANY MIXING. WITH A DECENT PRESSURE GRADIENT OVER THE
AREA WILL STILL MAINTAIN A PUFF OF WIND IT APPEARS. ALSO WILL SEE
SOME WARM ADVECTION MAKING INTO THE AREA BY AND AFTER 06Z SAT.
INHERITED MIN TEMPS FROM PREV SHIFT GENERALLY LOOK GOOD...WITH MINOR
ADJUSTMENTS.
SATURDAY WILL BE ANOTHER PLEASANT DAY. SFC HIGH PRESSURE SLOWLY
PULLS EAST WITH A RETURN S/SW FLOW SETTING UP BY THE AFTERNOON.
BUMPED UP MAX TEMPS FOR SATURDAY A GOOD 3-5 DEGREES AREA-WIDE WITH
925MB TEMPS PROGGED AROUND 8-9C...EXPECT TEMPS TO REBOUND INTO THE
MID 50S NORTHERN LOWLANDS AND UPPER 50S TO 60 CENTRAL AND SOUTHERN
LOWLANDS. IT WILL STILL BE ON THE BREEZY SIDE BUT NOT NEARLY AS
GUSTY AS FRIDAY...SO IT WILL PROBABLY FEEL MUCH NICER THAN FRIDAY.
SATURDAY NIGHT...INHERITED MINS THE LOW/MID 30S LOWLANDS STILL
APPEAR ON TRACK AGAIN...WITH JUST A FEW ADJUSTMENTS. A WEAK
DISTURBANCE IN THE NEAR ZONAL FLOW MAY DRAG A WEAK COLD FRONT INTO
THE NORTHERN ZONES BY END OF PERIOD AND THUS WILL CONTINUE THE
SLIGHT TO LOW CHANCE POPS FROM PREV SHIFT IN THESE AREAS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
MODELS SHOWING A WEAK SYSTEM SYSTEM MOVING THROUGH SATURDAY NIGHT
INTO SUNDAY. TYPE OF PRECIPITATION IS QUESTIONABLE BASED ON TIMING
AND HOW MUCH RADIATION OCCURS SATURDAY NIGHT IN ADVANCE OF THE
SYSTEM. USED A BLEND OF THE ECMWF AND GFS.
FOR MONDAY THROUGH WEDNESDAY...USED A BLEND OF THE GEFS ENSEMBLE
MEAN AND ECMWF ENSEMBLE MEAN. THIS KEEPS A TROUGH OVER THE EASTERN
UNITED STATES CREATING A WINTER WEATHER SITUATION WHERE VARIOUS
WAVES COULD CREATE SNOW AT TIMES. THE TIMING OF THE WAVES AND
INTENSITY OF THE COLD AIR REMAIN IN QUESTION HOWEVER...AS VARIOUS
ENSEMBLE MEMBERS VARY CONSIDERABLY.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
WIND BECOME CALM OVERNIGHT AS THE ATMOSPHERE DECOUPLES. WEAK HIGH
PRESSURE KEEPS CONDITIONS DRY TONIGHT INTO EARLY THURSDAY.
SFC WIND BECOMES SOUTHEAST AND THEN SOUTH THURSDAY INTO THURSDAY
NIGHT. ALOFT...DEEP SOUTHWESTERLY FLOW INCREASES AFTER 12Z
THURSDAY AHEAD OF A STRONG COLD FRONT. MODELS SHOW H85 WINDS
INCREASING TO 50 BY 18Z THURSDAY...AND EVEN 70 KNOTS BY 06Z
FRIDAY...AHEAD OF THE FRONT.
MAIN SQUALL LINE WITH FAST MOVING SHOWERS/EMBEDDED THUNDERSTORM
SHOULD STILL BE WEST OF AREA AT 00Z FRIDAY. CONVECTION AHEAD OF
FROPA SHOULD REACH SOUTHEAST OH BY 06-09Z FRIDAY. THERE IS A
SLIGHT RISK FOR DAMAGING WINDS WITH STORMS WITH THIS FROPA. THE
WINDY SHOWERS OR STORMS WILL SPREAD QUICKLY EAST. THIS WILL BE AN
HIGH SHEAR...LOW CAPE ENVIRONMENT...WITH PW AROUND 1 INCH.
LOW LEVEL WIND SHEAR IS POSSIBLE EARLY THURSDAY MORNING AS WINDS
ALOFT INCREASE AND THE SFC REMAINS DECOUPLED FOR FEW HOURS UNTIL
DIURNAL MIXING TAKES PLACE. WILL CONSIDER TO CODE LLWS IN 12Z TAF
ISSUANCE.
HAVE CLOUDS THICKENING FROM 12 TO 18Z THURSDAY FROM SOUTH TO NORTH
DOWN TO 3500 FEET...EXCEPT 2500 FEET EXTREME NORTHWEST PORTIONS OF
OUR CWA. CEILINGS DETERIORATE WITH THE PROXIMITY OF FROPA
OVERNIGHT THURSDAY NIGHT DOWN TO AROUND 2000 FEET UNDER RAIN
SHOWERS. BRIEF PERIODS OF IFR POSSIBLE ALONG HEAVIEST SHOWERS.
CEILINGS WILL REMAIN AT LEAST MVFR FOR THE MOST PART AFTER FROPA
EXCEPT IFR ALONG THE EASTERN MOUNTAINS BY FRIDAY 12Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: MORE SHOWER COVERAGE ASSOCIATED WITH THE WARM
FRONT A BIT FURTHER EAST THAN FORECAST. TIMING COVERAGE OF LOWER
CLOUDS DEVELOPING ON EASTERN SLOPES 18Z THURSDAY TO 00Z FRIDAY
COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE THU 02/20/14
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H M M H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY L L L H H H H H M M M H
CKB CONSISTENCY L H H H H H H H H H H H
AFTER 06Z FRIDAY...
IFR POSSIBLE THURSDAY NIGHT IN FAST MOVING AND GUSTY SHOWERS...AND
POSSIBLY A BRIEF THUNDERSTORM.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...RPY
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS NORMAN OK
1135 AM CST THU FEB 20 2014
.DISCUSSION...
THE 18Z AVIATION DISCUSSION FOLLOWS....
&&
.AVIATION...
STRONG NW WINDS WILL DIMINISH THIS AFTERNOON...AND BECOME LIGHT NW
THIS EVENING...THEN LIGHT SW OVERNIGHT...AS THE STRONG LOW
PRESSURE AREA RESPONSIBLE FOR THEM MOVES AWAY TO THE NE. BY
TOMORROW MORNING...HIGH PRESSURE OVER TX WILL SET UP A MODERATE
PRESSURE GRADIENT AGAIN...AND WINDS WILL INCREASE QUICKLY BY MID-
MORNING AS VERTICAL MIXING RESUMES. A FEW CLOUDS AROUND 2500-3500 FT
AGL WILL LAST A FEW MORE HOURS ACROSS N AND CENTRAL OK BEFORE
DISSIPATING LATE THIS AFTERNOON. EXPECT CLEAR SKIES TONIGHT...AND
JUST SOME HIGH CLOUDS TOMORROW. VISIBILITY RESTRICTIONS ARE NOT
EXPECTED THROUGH THE PERIOD...AS BLDU APPEARS TO HAVE DECREASED
SUBSTANTIALLY...AND IS NOT EXPECTED TO RESUME.
&&
.PREV DISCUSSION... /ISSUED 1037 AM CST THU FEB 20 2014/
UPDATE...
MINOR UPDATES TO THE FORECAST THIS MORNING INCLUDE REMOVAL OF
POPS ACROSS FAR NORTHERN OKLAHOMA. BATCH OF VERY LIGHT PRECIP HAS
MOVED NORTH INTO SRN KS...AND DONT EXPECT ANY FURTHER PRECIP HERE.
ALSO EXPANDED MENTION OF BLOWING DUST INTO PORTIONS OF NORTHERN
AND CENTRAL OKLAHOMA...AND WESTERN NORTH TEXAS. HIGH TEMPS WERE
TWEAKED TO REFLECT COOLER POST FRONTAL AIR ENTERING THE REGION.
EXPECT WINDS TO REMAIN ELEVATED THROUGH THE DAY...AND ONE OR TWO
MORE SEVERE WIND GUSTS MAY OCCUR BEFORE 3PM...MAINLY OVER FAR
NORTH CENTRAL OKLAHOMA. ELSEWHERE...EXPECT SUSTAINED 25 TO 35 MPH
WINDS WITH GUSTS OF 40 TO 45 MPH THROUGH MID AFTERNOON.
THEREAFTER...WINDS WILL GRADUALLY DECREASE IN SPEED THROUGH THIS
EVENING.
PREV DISCUSSION... /ISSUED 547 AM CST THU FEB 20 2014/
AVIATION...20 FEB 12Z TAF ISSUANCE...
MAJOR AVIATION CONCERN IS FOCUSED ON EXCESSIVE WINDS THIS MORNING
THROUGH THE EARLY AFTERNOON. CURRENTLY... WINDS ACROSS THE
PANHANDLES INTO SWRN KS ARE SUSTAINED 30 TO 40... GUSTING 45 TO
50 KTS. THESE STOUT WINDS WILL MOVE INTO NWRN OK THROUGH
SUNRISE... SPREADING E/SE ACROSS THE REGION THROUGH THE DAY AS THE
COLD FRONT CONTINUES ITS SURGE. WITH STRONG WINDS... BLOWING DIRT
WILL CAUSE VISIBILITY ISSUES AT AIRFIELDS ACROSS WRN AND CENTRAL
OKLAHOMA. EXPECT AIRFIELDS ACROSS WRN OK AND CENTRAL OK TO FLIRT
WITH MVFR VISIBILITIES THROUGH THE MORNING OFF AND ON DUE TO THE
BLOWING DIRT. LOW TO MID LEVEL STRATUS WILL CONTINUE TO STREAM TO
THE E/NE THIS MORNING... WITH ANY REMAINING MVFR CIGS ACROSS WRN
OK IMPROVING THROUGH THE MORNING AS THE FRONT MOVES IN. WINDS WILL
CALM EVER SO SLIGHTLY THROUGH THE AFTERNOON... CALMING AND BACKING
OUT OF THE SOUTHWEST OVERNIGHT THROUGH THE END OF THE PERIOD.
JTK
PREV DISCUSSION... /ISSUED 416 AM CST THU FEB 20 2014/
DISCUSSION...
PRIMARY FORECAST CONCERN REMAINS FOCUSED IN THE NEAR TERM... ON VERY
HIGH WINDS... ESPECIALLY ACROSS WRN AND NWRN OK... WHERE SUSTAINED
WINDS WILL REACH 40 MPH WITH GUSTS UP TO 60 ARE EXPECTED.
CURRENTLY... THROUGH 3 AM... ALREADY SEEING SUSTAINED WINDS OF 35-
40MPH IN THE PANHANDLE... WITH GUSTS 45-55. 09Z SFC ANALYSIS REVEALS
AN IMPRESSIVE 992MB SFC LOW TRAVERSING THE WRN OK/KS BORDER... WITH
A STOUT COLD FRONT EXTENDING FROM N/NE OF DODGE CITY S/SW ACROSS THE
PANHANDLES. RAP/NAM GUIDANCE HAS CONSISTENTLY PRODUCED 3HR PRES
CHANGE ALONG THE FRONT/SFC TROUGH OF 8 TO 10MB... ALONG WITH 0-1KM
LAPSE RATES OVER 7-8 C/KM. WITH HIGH CONFIDENCE FOR STRONG...
POTENTIALLY DAMAGING WINDS ACROSS NWRN OK... UPGRADED THE WIND
ADVISORY TO A HIGH WIND WARNING FOR PORTIONS OF NWRN OK... 40 MPH
SUSTAINED WITH GUSTS TO 60 MPH. BEST POTENTIAL FOR DAMAGING WIND
GUSTS WILL BE FROM NOW THROUGH MID/LATE MORNING.
WINDS WILL INCREASE ACROSS CENTRAL AND SRN OK AND WRN N TX THROUGH
THE MID TO LATE MORNING AS THE COLD FRONT CONTINUES TO TREK E/SE
ACROSS THE REGION. EXPECT THE COLD FRONT TO REACH THE OKC METRO SW
ALONG THE I-44 CORRIDOR NEAR NOON. SUSTAINED WINDS OF 30 TO 40
GUSTING 50 TO 55 MPH CAN BE EXPECTED THROUGH THE EARLY AFTERNOON.
MORNING COMMUTERS SHOULD TAKE CAUTION DRIVING THIS MORNING...
ESPECIALLY WHEN PILOTING A HIGH PROFILE VEHICLE ALONG E/W ROADS.
WIND GUSTS NEAR 60 MPH ARE CAPABLE OF MINOR DAMAGE TO TREES AND
POWER LINES. ALONG WITH STOUT WINDS... DRY AIR WILL FUNNEL IN ACROSS
THE REGION BEHIND THE FRONT. WITH THIS COMBINATION... ANY FIRES WILL
BURN OUT OF CONTROL QUICKLY... OUTSIDE BURNING IS HIGHLY DISCOURAGED
AND ANY FIRE WILL CAUSE A THREAT TO LIFE AND PROPERTY.
NORTH AND WEST OF THE SFC LOW... SOME ISOLATED -RA WILL CONTINUE TO
MOVE EWRD JUST NORTH OF THE OK/KS BORDER THIS MORNING. RECENT RUNS
OF THE HRRR AND NSSL WRF INDICATED SOME OF THIS ACTIVITY MAY DRIFT
SOUTH INTO FAR NRN OK. THIS IS A REASONABLE SCENARIO GIVEN THE
AVAILABLE MOISTURE AND RADAR TREND. WENT AHEAD AND STUCK SOME SLGT
CHC POPS ALONG THE NRN OK BORDER FOR THE MORNING HOURS.
WINDS WILL SLOWLY LESSEN THROUGH SUNSET FROM WEST TO EAST. REMAINING
WELL MIXED... TEMPS WILL COOL SLIGHTLY BEHIND THE FRONT... WITH AFTN
HIGHS IN THE MID 50S ACROSS NRN OK TO THE LOWER 60S ACROSS TEXOMA.
FOR FRIDAY... WINDS WILL QUICKLY BACK TO THE SW AS THE SFC HIGH
SLIDES TO TX GULF COAST. WINDS... ALTHOUGH NOT AS STRONG AS TODAY...
WILL INCREASE ONCE AGAIN. BUFR SOUNDINGS SHOW WRN N TX/SWRN OK
DRYING OUT AND MIXING QUICKLY BY THE AFTN. WITH BL FLOW OF 20 TO
30KTS... RH VALUES WILL DIP INTO THE LOWER 20S/UPPER TEENS FOR A FEW
HOURS IN THE AFTN. IN RESPONSE... VERY HIGH FIRE DANGER IS
ANTICIPATED FOR FRIDAY AS AFTN HIGHS CLIMB INTO THE MID TO UPPER 60S
AND SW WINDS ACROSS WRN OK/WRN N TX GUST INTO THE MID 20S.
BROAD TROUGHING WILL SET UP THROUGH SATURDAY WITH PSUEDO-ZONAL
FLOW ACROSS THE SRN PLAINS... S/SW SFC/BL FLOW WILL CONTINUE...
WITH WELL ABOVE AVG TEMPS PERSISTING. THE PATTERN WILL BEGIN TO
CHANGE LEADING INTO SUN... AS A WEAK H500 SHORT WAVE DEVELOPS OVER
THE ROCKIES... AND A COLD FRONT DROPS SWRD SUN MORNING. THIS IS
WHERE THE GFS/ECMWF SOLUTIONS START TO DIVERGE WITH REGARDS TO THE
SFC/BL. THE OVERALL SYNOPTIC PATTERN IS SIMILAR BTWN THE TWO...
BUT THE GFS IS MORE AGGRESSIVE WITH THE SFC HIGH SETTLING SWRD
INTO THE SRN PLAINS THROUGH MON. MEANWHILE THE ECMWF SETS UP GULF
RETURN FLOW...AND DEVELOPS SOME LIGHT QPF ACROSS CENTRAL AND ERN
OK. OF COURSE... THESE DIFFERENCES HAVE CREATED SOME CONFIDENCE
ISSUES WITH REGARDS TO TEMPS. GIVEN THE PATTERN... EXPECT A REGION
OF CANADIAN HIGH PRESSURE TO SLIDE S/SE ACROSS THE MIDWEST...
WITH TEMPS COOLING BACK AT OR NEAR NORMAL BY TUESDAY. TOOK A
CONSERVATIVE ROUTE WITH TEMPS... NOT GOING AS EXTREME AS THE
GFS...BUT A TAD COOLER THAN THE ECMWF... I GUESS YOU COULD SAY I
MADE A COMPROMISE. KEEP CHECKING BACK AS THE FORECAST FOR NEXT
WEEK BECOMES CLEARER.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 52 32 66 37 / 0 0 0 0
HOBART OK 53 31 64 35 / 0 0 0 0
WICHITA FALLS TX 58 34 69 39 / 0 0 0 0
GAGE OK 49 26 63 29 / 0 0 0 0
PONCA CITY OK 49 28 63 33 / 10 0 0 0
DURANT OK 68 38 66 41 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR OKZ005>008-
011>048-050>052.
TX...WIND ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR TXZ083>090.
&&
$$
84/23/23
AREA FORECAST DISCUSSION
NWS NORMAN OK
1037 AM CST THU FEB 20 2014
.UPDATE...
MINOR UPDATES TO THE FORECAST THIS MORNING INCLUDE REMOVAL OF
POPS ACROSS FAR NORTHERN OKLAHOMA. BATCH OF VERY LIGHT PRECIP HAS
MOVED NORTH INTO SRN KS...AND DONT EXPECT ANY FURTHER PRECIP HERE.
ALSO EXPANDED MENTION OF BLOWING DUST INTO PORTIONS OF NORTHERN
AND CENTRAL OKLAHOMA...AND WESTERN NORTH TEXAS. HIGH TEMPS WERE
TWEAKED TO REFLECT COOLER POST FRONTAL AIR ENTERING THE REGION.
EXPECT WINDS TO REMAIN ELEVATED THROUGH THE DAY...AND ONE OR TWO
MORE SEVERE WIND GUSTS MAY OCCUR BEFORE 3PM...MAINLY OVER FAR
NORTH CENTRAL OKLAHOMA. ELSEWHERE...EXPECT SUSTAINED 25 TO 35 MPH
WINDS WITH GUSTS OF 40 TO 45 MPH THROUGH MID AFTERNOON.
THEREAFTER...WINDS WILL GRADUALLY DECREASE IN SPEED THROUGH THIS
EVENING.
&&
.PREV DISCUSSION... /ISSUED 547 AM CST THU FEB 20 2014/
AVIATION...20 FEB 12Z TAF ISSUANCE...
MAJOR AVIATION CONCERN IS FOCUSED ON EXCESSIVE WINDS THIS MORNING
THROUGH THE EARLY AFTERNOON. CURRENTLY... WINDS ACROSS THE
PANHANDLES INTO SWRN KS ARE SUSTAINED 30 TO 40... GUSTING 45 TO
50 KTS. THESE STOUT WINDS WILL MOVE INTO NWRN OK THROUGH
SUNRISE... SPREADING E/SE ACROSS THE REGION THROUGH THE DAY AS THE
COLD FRONT CONTINUES ITS SURGE. WITH STRONG WINDS... BLOWING DIRT
WILL CAUSE VISIBILITY ISSUES AT AIRFIELDS ACROSS WRN AND CENTRAL
OKLAHOMA. EXPECT AIRFIELDS ACROSS WRN OK AND CENTRAL OK TO FLIRT
WITH MVFR VISIBILITIES THROUGH THE MORNING OFF AND ON DUE TO THE
BLOWING DIRT. LOW TO MID LEVEL STRATUS WILL CONTINUE TO STREAM TO
THE E/NE THIS MORNING... WITH ANY REMAINING MVFR CIGS ACROSS WRN
OK IMPROVING THROUGH THE MORNING AS THE FRONT MOVES IN. WINDS WILL
CALM EVER SO SLIGHTLY THROUGH THE AFTERNOON... CALMING AND BACKING
OUT OF THE SOUTHWEST OVERNIGHT THROUGH THE END OF THE PERIOD.
JTK
PREV DISCUSSION... /ISSUED 416 AM CST THU FEB 20 2014/
DISCUSSION...
PRIMARY FORECAST CONCERN REMAINS FOCUSED IN THE NEAR TERM... ON VERY
HIGH WINDS... ESPECIALLY ACROSS WRN AND NWRN OK... WHERE SUSTAINED
WINDS WILL REACH 40 MPH WITH GUSTS UP TO 60 ARE EXPECTED.
CURRENTLY... THROUGH 3 AM... ALREADY SEEING SUSTAINED WINDS OF 35-
40MPH IN THE PANHANDLE... WITH GUSTS 45-55. 09Z SFC ANALYSIS REVEALS
AN IMPRESSIVE 992MB SFC LOW TRAVERSING THE WRN OK/KS BORDER... WITH
A STOUT COLD FRONT EXTENDING FROM N/NE OF DODGE CITY S/SW ACROSS THE
PANHANDLES. RAP/NAM GUIDANCE HAS CONSISTENTLY PRODUCED 3HR PRES
CHANGE ALONG THE FRONT/SFC TROUGH OF 8 TO 10MB... ALONG WITH 0-1KM
LAPSE RATES OVER 7-8 C/KM. WITH HIGH CONFIDENCE FOR STRONG...
POTENTIALLY DAMAGING WINDS ACROSS NWRN OK... UPGRADED THE WIND
ADVISORY TO A HIGH WIND WARNING FOR PORTIONS OF NWRN OK... 40 MPH
SUSTAINED WITH GUSTS TO 60 MPH. BEST POTENTIAL FOR DAMAGING WIND
GUSTS WILL BE FROM NOW THROUGH MID/LATE MORNING.
WINDS WILL INCREASE ACROSS CENTRAL AND SRN OK AND WRN N TX THROUGH
THE MID TO LATE MORNING AS THE COLD FRONT CONTINUES TO TREK E/SE
ACROSS THE REGION. EXPECT THE COLD FRONT TO REACH THE OKC METRO SW
ALONG THE I-44 CORRIDOR NEAR NOON. SUSTAINED WINDS OF 30 TO 40
GUSTING 50 TO 55 MPH CAN BE EXPECTED THROUGH THE EARLY AFTERNOON.
MORNING COMMUTERS SHOULD TAKE CAUTION DRIVING THIS MORNING...
ESPECIALLY WHEN PILOTING A HIGH PROFILE VEHICLE ALONG E/W ROADS.
WIND GUSTS NEAR 60 MPH ARE CAPABLE OF MINOR DAMAGE TO TREES AND
POWER LINES. ALONG WITH STOUT WINDS... DRY AIR WILL FUNNEL IN ACROSS
THE REGION BEHIND THE FRONT. WITH THIS COMBINATION... ANY FIRES WILL
BURN OUT OF CONTROL QUICKLY... OUTSIDE BURNING IS HIGHLY DISCOURAGED
AND ANY FIRE WILL CAUSE A THREAT TO LIFE AND PROPERTY.
NORTH AND WEST OF THE SFC LOW... SOME ISOLATED -RA WILL CONTINUE TO
MOVE EWRD JUST NORTH OF THE OK/KS BORDER THIS MORNING. RECENT RUNS
OF THE HRRR AND NSSL WRF INDICATED SOME OF THIS ACTIVITY MAY DRIFT
SOUTH INTO FAR NRN OK. THIS IS A REASONABLE SCENARIO GIVEN THE
AVAILABLE MOISTURE AND RADAR TREND. WENT AHEAD AND STUCK SOME SLGT
CHC POPS ALONG THE NRN OK BORDER FOR THE MORNING HOURS.
WINDS WILL SLOWLY LESSEN THROUGH SUNSET FROM WEST TO EAST. REMAINING
WELL MIXED... TEMPS WILL COOL SLIGHTLY BEHIND THE FRONT... WITH AFTN
HIGHS IN THE MID 50S ACROSS NRN OK TO THE LOWER 60S ACROSS TEXOMA.
FOR FRIDAY... WINDS WILL QUICKLY BACK TO THE SW AS THE SFC HIGH
SLIDES TO TX GULF COAST. WINDS... ALTHOUGH NOT AS STRONG AS TODAY...
WILL INCREASE ONCE AGAIN. BUFR SOUNDINGS SHOW WRN N TX/SWRN OK
DRYING OUT AND MIXING QUICKLY BY THE AFTN. WITH BL FLOW OF 20 TO
30KTS... RH VALUES WILL DIP INTO THE LOWER 20S/UPPER TEENS FOR A FEW
HOURS IN THE AFTN. IN RESPONSE... VERY HIGH FIRE DANGER IS
ANTICIPATED FOR FRIDAY AS AFTN HIGHS CLIMB INTO THE MID TO UPPER 60S
AND SW WINDS ACROSS WRN OK/WRN N TX GUST INTO THE MID 20S.
BROAD TROUGHING WILL SET UP THROUGH SATURDAY WITH PSUEDO-ZONAL
FLOW ACROSS THE SRN PLAINS... S/SW SFC/BL FLOW WILL CONTINUE...
WITH WELL ABOVE AVG TEMPS PERSISTING. THE PATTERN WILL BEGIN TO
CHANGE LEADING INTO SUN... AS A WEAK H500 SHORT WAVE DEVELOPS OVER
THE ROCKIES... AND A COLD FRONT DROPS SWRD SUN MORNING. THIS IS
WHERE THE GFS/ECMWF SOLUTIONS START TO DIVERGE WITH REGARDS TO THE
SFC/BL. THE OVERALL SYNOPTIC PATTERN IS SIMILAR BTWN THE TWO...
BUT THE GFS IS MORE AGGRESSIVE WITH THE SFC HIGH SETTLING SWRD
INTO THE SRN PLAINS THROUGH MON. MEANWHILE THE ECMWF SETS UP GULF
RETURN FLOW...AND DEVELOPS SOME LIGHT QPF ACROSS CENTRAL AND ERN
OK. OF COURSE... THESE DIFFERENCES HAVE CREATED SOME CONFIDENCE
ISSUES WITH REGARDS TO TEMPS. GIVEN THE PATTERN... EXPECT A REGION
OF CANADIAN HIGH PRESSURE TO SLIDE S/SE ACROSS THE MIDWEST...
WITH TEMPS COOLING BACK AT OR NEAR NORMAL BY TUESDAY. TOOK A
CONSERVATIVE ROUTE WITH TEMPS... NOT GOING AS EXTREME AS THE
GFS...BUT A TAD COOLER THAN THE ECMWF... I GUESS YOU COULD SAY I
MADE A COMPROMISE. KEEP CHECKING BACK AS THE FORECAST FOR NEXT
WEEK BECOMES CLEARER.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 52 32 66 37 / 0 0 0 0
HOBART OK 53 31 64 35 / 0 0 0 0
WICHITA FALLS TX 58 34 69 39 / 0 0 0 0
GAGE OK 49 26 63 29 / 0 0 0 0
PONCA CITY OK 49 28 63 33 / 10 0 0 0
DURANT OK 68 38 66 41 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR OKZ008-013-
018>020-023>048-050>052.
HIGH WIND WARNING UNTIL 3 PM CST THIS AFTERNOON FOR OKZ004>007-
009>012-014>017-021-022.
TX...WIND ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR TXZ083>090.
&&
$$
84/23
AREA FORECAST DISCUSSION
NWS NORMAN OK
547 AM CST THU FEB 20 2014
.AVIATION...20 FEB 12Z TAF ISSUANCE...
MAJOR AVIATION CONCERN IS FOCUSED ON EXCESSIVE WINDS THIS MORNING
THROUGH THE EARLY AFTERNOON. CURRENTLY... WINDS ACROSS THE
PANHANDLES INTO SWRN KS ARE SUSTAINED 30 TO 40... GUSTING 45 TO
50 KTS. THESE STOUT WINDS WILL MOVE INTO NWRN OK THROUGH
SUNRISE... SPREADING E/SE ACROSS THE REGION THROUGH THE DAY AS THE
COLD FRONT CONTINUES ITS SURGE. WITH STRONG WINDS... BLOWING DIRT
WILL CAUSE VISIBILITY ISSUES AT AIRFIELDS ACROSS WRN AND CENTRAL
OKLAHOMA. EXPECT AIRFIELDS ACROSS WRN OK AND CENTRAL OK TO FLIRT
WITH MVFR VISIBILITIES THROUGH THE MORNING OFF AND ON DUE TO THE
BLOWING DIRT. LOW TO MID LEVEL STRATUS WILL CONTINUE TO STREAM TO
THE E/NE THIS MORNING... WITH ANY REMAINING MVFR CIGS ACROSS WRN
OK IMPROVING THROUGH THE MORNING AS THE FRONT MOVES IN. WINDS WILL
CALM EVER SO SLIGHTLY THROUGH THE AFTERNOON... CALMING AND BACKING
OUT OF THE SOUTHWEST OVERNIGHT THROUGH THE END OF THE PERIOD.
JTK
&&
.PREV DISCUSSION... /ISSUED 416 AM CST THU FEB 20 2014/
DISCUSSION...
PRIMARY FORECAST CONCERN REMAINS FOCUSED IN THE NEAR TERM... ON VERY
HIGH WINDS... ESPECIALLY ACROSS WRN AND NWRN OK... WHERE SUSTAINED
WINDS WILL REACH 40 MPH WITH GUSTS UP TO 60 ARE EXPECTED.
CURRENTLY... THROUGH 3 AM... ALREADY SEEING SUSTAINED WINDS OF 35-
40MPH IN THE PANHANDLE... WITH GUSTS 45-55. 09Z SFC ANALYSIS REVEALS
AN IMPRESSIVE 992MB SFC LOW TRAVERSING THE WRN OK/KS BORDER... WITH
A STOUT COLD FRONT EXTENDING FROM N/NE OF DODGE CITY S/SW ACROSS THE
PANHANDLES. RAP/NAM GUIDANCE HAS CONSISTENTLY PRODUCED 3HR PRES
CHANGE ALONG THE FRONT/SFC TROUGH OF 8 TO 10MB... ALONG WITH 0-1KM
LAPSE RATES OVER 7-8 C/KM. WITH HIGH CONFIDENCE FOR STRONG...
POTENTIALLY DAMAGING WINDS ACROSS NWRN OK... UPGRADED THE WIND
ADVISORY TO A HIGH WIND WARNING FOR PORTIONS OF NWRN OK... 40 MPH
SUSTAINED WITH GUSTS TO 60 MPH. BEST POTENTIAL FOR DAMAGING WIND
GUSTS WILL BE FROM NOW THROUGH MID/LATE MORNING.
WINDS WILL INCREASE ACROSS CENTRAL AND SRN OK AND WRN N TX THROUGH
THE MID TO LATE MORNING AS THE COLD FRONT CONTINUES TO TREK E/SE
ACROSS THE REGION. EXPECT THE COLD FRONT TO REACH THE OKC METRO SW
ALONG THE I-44 CORRIDOR NEAR NOON. SUSTAINED WINDS OF 30 TO 40
GUSTING 50 TO 55 MPH CAN BE EXPECTED THROUGH THE EARLY AFTERNOON.
MORNING COMMUTERS SHOULD TAKE CAUTION DRIVING THIS MORNING...
ESPECIALLY WHEN PILOTING A HIGH PROFILE VEHICLE ALONG E/W ROADS.
WIND GUSTS NEAR 60 MPH ARE CAPABLE OF MINOR DAMAGE TO TREES AND
POWER LINES. ALONG WITH STOUT WINDS... DRY AIR WILL FUNNEL IN ACROSS
THE REGION BEHIND THE FRONT. WITH THIS COMBINATION... ANY FIRES WILL
BURN OUT OF CONTROL QUICKLY... OUTSIDE BURNING IS HIGHLY DISCOURAGED
AND ANY FIRE WILL CAUSE A THREAT TO LIFE AND PROPERTY.
NORTH AND WEST OF THE SFC LOW... SOME ISOLATED -RA WILL CONTINUE TO
MOVE EWRD JUST NORTH OF THE OK/KS BORDER THIS MORNING. RECENT RUNS
OF THE HRRR AND NSSL WRF INDICATED SOME OF THIS ACTIVITY MAY DRIFT
SOUTH INTO FAR NRN OK. THIS IS A REASONABLE SCENARIO GIVEN THE
AVAILABLE MOISTURE AND RADAR TREND. WENT AHEAD AND STUCK SOME SLGT
CHC POPS ALONG THE NRN OK BORDER FOR THE MORNING HOURS.
WINDS WILL SLOWLY LESSEN THROUGH SUNSET FROM WEST TO EAST. REMAINING
WELL MIXED... TEMPS WILL COOL SLIGHTLY BEHIND THE FRONT... WITH AFTN
HIGHS IN THE MID 50S ACROSS NRN OK TO THE LOWER 60S ACROSS TEXOMA.
FOR FRIDAY... WINDS WILL QUICKLY BACK TO THE SW AS THE SFC HIGH
SLIDES TO TX GULF COAST. WINDS... ALTHOUGH NOT AS STRONG AS TODAY...
WILL INCREASE ONCE AGAIN. BUFR SOUNDINGS SHOW WRN N TX/SWRN OK
DRYING OUT AND MIXING QUICKLY BY THE AFTN. WITH BL FLOW OF 20 TO
30KTS... RH VALUES WILL DIP INTO THE LOWER 20S/UPPER TEENS FOR A FEW
HOURS IN THE AFTN. IN RESPONSE... VERY HIGH FIRE DANGER IS
ANTICIPATED FOR FRIDAY AS AFTN HIGHS CLIMB INTO THE MID TO UPPER 60S
AND SW WINDS ACROSS WRN OK/WRN N TX GUST INTO THE MID 20S.
BROAD TROUGHING WILL SET UP THROUGH SATURDAY WITH PSUEDO-ZONAL
FLOW ACROSS THE SRN PLAINS... S/SW SFC/BL FLOW WILL CONTINUE...
WITH WELL ABOVE AVG TEMPS PERSISTING. THE PATTERN WILL BEGIN TO
CHANGE LEADING INTO SUN... AS A WEAK H500 SHORT WAVE DEVELOPS OVER
THE ROCKIES... AND A COLD FRONT DROPS SWRD SUN MORNING. THIS IS
WHERE THE GFS/ECMWF SOLUTIONS START TO DIVERGE WITH REGARDS TO THE
SFC/BL. THE OVERALL SYNOPTIC PATTERN IS SIMILAR BTWN THE TWO...
BUT THE GFS IS MORE AGGRESSIVE WITH THE SFC HIGH SETTLING SWRD
INTO THE SRN PLAINS THROUGH MON. MEANWHILE THE ECMWF SETS UP GULF
RETURN FLOW...AND DEVELOPS SOME LIGHT QPF ACROSS CENTRAL AND ERN
OK. OF COURSE... THESE DIFFERENCES HAVE CREATED SOME CONFIDENCE
ISSUES WITH REGARDS TO TEMPS. GIVEN THE PATTERN... EXPECT A REGION
OF CANADIAN HIGH PRESSURE TO SLIDE S/SE ACROSS THE MIDWEST...
WITH TEMPS COOLING BACK AT OR NEAR NORMAL BY TUESDAY. TOOK A
CONSERVATIVE ROUTE WITH TEMPS... NOT GOING AS EXTREME AS THE
GFS...BUT A TAD COOLER THAN THE ECMWF... I GUESS YOU COULD SAY I
MADE A COMPROMISE. KEEP CHECKING BACK AS THE FORECAST FOR NEXT
WEEK BECOMES CLEARER.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 56 32 66 37 / 0 0 0 0
HOBART OK 56 31 64 35 / 0 0 0 0
WICHITA FALLS TX 61 34 69 39 / 0 0 0 0
GAGE OK 52 26 63 29 / 10 0 0 0
PONCA CITY OK 55 28 63 33 / 20 0 0 0
DURANT OK 64 38 66 41 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR OKZ008-013-
018>020-023>048-050>052.
HIGH WIND WARNING UNTIL 3 PM CST THIS AFTERNOON FOR OKZ004>007-
009>012-014>017-021-022.
TX...WIND ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR TXZ083>090.
&&
$$
11/04/04
AREA FORECAST DISCUSSION
NWS NORMAN OK
416 AM CST THU FEB 20 2014
.DISCUSSION...
PRIMARY FORECAST CONCERN REMAINS FOCUSED IN THE NEAR TERM... ON VERY
HIGH WINDS... ESPECIALLY ACROSS WRN AND NWRN OK... WHERE SUSTAINED
WINDS WILL REACH 40 MPH WITH GUSTS UP TO 60 ARE EXPECTED.
CURRENTLY... THROUGH 3 AM... ALREADY SEEING SUSTAINED WINDS OF 35-
40MPH IN THE PANHANDLE... WITH GUSTS 45-55. 09Z SFC ANALYSIS REVEALS
AN IMPRESSIVE 992MB SFC LOW TRAVERSING THE WRN OK/KS BORDER... WITH
A STOUT COLD FRONT EXTENDING FROM N/NE OF DODGE CITY S/SW ACROSS THE
PANHANDLES. RAP/NAM GUIDANCE HAS CONSISTENTLY PRODUCED 3HR PRES
CHANGE ALONG THE FRONT/SFC TROUGH OF 8 TO 10MB... ALONG WITH 0-1KM
LAPSE RATES OVER 7-8 C/KM. WITH HIGH CONFIDENCE FOR STRONG...
POTENTIALLY DAMAGING WINDS ACROSS NWRN OK... UPGRADED THE WIND
ADVISORY TO A HIGH WIND WARNING FOR PORTIONS OF NWRN OK... 40 MPH
SUSTAINED WITH GUSTS TO 60 MPH. BEST POTENTIAL FOR DAMAGING WIND
GUSTS WILL BE FROM NOW THROUGH MID/LATE MORNING.
WINDS WILL INCREASE ACROSS CENTRAL AND SRN OK AND WRN N TX THROUGH
THE MID TO LATE MORNING AS THE COLD FRONT CONTINUES TO TREK E/SE
ACROSS THE REGION. EXPECT THE COLD FRONT TO REACH THE OKC METRO SW
ALONG THE I-44 CORRIDOR NEAR NOON. SUSTAINED WINDS OF 30 TO 40
GUSTING 50 TO 55 MPH CAN BE EXPECTED THROUGH THE EARLY AFTERNOON.
MORNING COMMUTERS SHOULD TAKE CAUTION DRIVING THIS MORNING...
ESPECIALLY WHEN PILOTING A HIGH PROFILE VEHICLE ALONG E/W ROADS.
WIND GUSTS NEAR 60 MPH ARE CAPABLE OF MINOR DAMAGE TO TREES AND
POWER LINES. ALONG WITH STOUT WINDS... DRY AIR WILL FUNNEL IN ACROSS
THE REGION BEHIND THE FRONT. WITH THIS COMBINATION... ANY FIRES WILL
BURN OUT OF CONTROL QUICKLY... OUTSIDE BURNING IS HIGHLY DISCOURAGED
AND ANY FIRE WILL CAUSE A THREAT TO LIFE AND PROPERTY.
NORTH AND WEST OF THE SFC LOW... SOME ISOLATED -RA WILL CONTINUE TO
MOVE EWRD JUST NORTH OF THE OK/KS BORDER THIS MORNING. RECENT RUNS
OF THE HRRR AND NSSL WRF INDICATED SOME OF THIS ACTIVITY MAY DRIFT
SOUTH INTO FAR NRN OK. THIS IS A REASONABLE SCENARIO GIVEN THE
AVAILABLE MOISTURE AND RADAR TREND. WENT AHEAD AND STUCK SOME SLGT
CHC POPS ALONG THE NRN OK BORDER FOR THE MORNING HOURS.
WINDS WILL SLOWLY LESSEN THROUGH SUNSET FROM WEST TO EAST. REMAINING
WELL MIXED... TEMPS WILL COOL SLIGHTLY BEHIND THE FRONT... WITH AFTN
HIGHS IN THE MID 50S ACROSS NRN OK TO THE LOWER 60S ACROSS TEXOMA.
FOR FRIDAY... WINDS WILL QUICKLY BACK TO THE SW AS THE SFC HIGH
SLIDES TO TX GULF COAST. WINDS... ALTHOUGH NOT AS STRONG AS TODAY...
WILL INCREASE ONCE AGAIN. BUFR SOUNDINGS SHOW WRN N TX/SWRN OK
DRYING OUT AND MIXING QUICKLY BY THE AFTN. WITH BL FLOW OF 20 TO
30KTS... RH VALUES WILL DIP INTO THE LOWER 20S/UPPER TEENS FOR A FEW
HOURS IN THE AFTN. IN RESPONSE... VERY HIGH FIRE DANGER IS
ANTICIPATED FOR FRIDAY AS AFTN HIGHS CLIMB INTO THE MID TO UPPER 60S
AND SW WINDS ACROSS WRN OK/WRN N TX GUST INTO THE MID 20S.
BROAD TROUGHING WILL SET UP THROUGH SATURDAY WITH PSUEDO-ZONAL
FLOW ACROSS THE SRN PLAINS... S/SW SFC/BL FLOW WILL CONTINUE...
WITH WELL ABOVE AVG TEMPS PERSISTING. THE PATTERN WILL BEGIN TO
CHANGE LEADING INTO SUN... AS A WEAK H500 SHORT WAVE DEVELOPS OVER
THE ROCKIES... AND A COLD FRONT DROPS SWRD SUN MORNING. THIS IS
WHERE THE GFS/ECMWF SOLUTIONS START TO DIVERGE WITH REGARDS TO THE
SFC/BL. THE OVERALL SYNOPTIC PATTERN IS SIMILAR BTWN THE TWO...
BUT THE GFS IS MORE AGGRESSIVE WITH THE SFC HIGH SETTLING SWRD
INTO THE SRN PLAINS THROUGH MON. MEANWHILE THE ECMWF SETS UP GULF
RETURN FLOW...AND DEVELOPS SOME LIGHT QPF ACROSS CENTRAL AND ERN
OK. OF COURSE... THESE DIFFERENCES HAVE CREATED SOME CONFIDENCE
ISSUES WITH REGARDS TO TEMPS. GIVEN THE PATTERN... EXPECT A REGION
OF CANADIAN HIGH PRESSURE TO SLIDE S/SE ACROSS THE MIDWEST...
WITH TEMPS COOLING BACK AT OR NEAR NORMAL BY TUESDAY. TOOK A
CONSERVATIVE ROUTE WITH TEMPS... NOT GOING AS EXTREME AS THE
GFS...BUT A TAD COOLER THAN THE ECMWF... I GUESS YOU COULD SAY I
MADE A COMPROMISE. KEEP CHECKING BACK AS THE FORECAST FOR NEXT
WEEK BECOMES CLEARER.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 56 32 66 37 / 0 0 0 0
HOBART OK 56 31 64 35 / 0 0 0 0
WICHITA FALLS TX 61 34 69 39 / 0 0 0 0
GAGE OK 52 26 63 29 / 10 0 0 0
PONCA CITY OK 55 28 63 33 / 20 0 0 0
DURANT OK 64 38 66 41 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR OKZ008-013-
018>020-023>048-050>052.
HIGH WIND WARNING UNTIL 3 PM CST THIS AFTERNOON FOR OKZ004>007-
009>012-014>017-021-022.
TX...WIND ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR TXZ083>090.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
928 AM PST THU FEB 20 2014
.SYNOPSIS...EXPECT A WET DAY TODAY IN THE LOWLANDS TODAY WITH PLENTY
OF SNOW IN THE CASCADES...AS A STALLED FRONTAL BOUNDARY KEEPS
PRECIPITATION AROUND THE FORECAST AREA. A SECONDARY DISTURBANCE WILL
MOVE ONSHORE ALONG THE BOUNDARY LATER TODAY...CAUSING STEADIER RAIN
IN THE VALLEYS BY AFTERNOON AND CONTINUED SNOW FOR THE CASCADE PASSES
AND ABOVE. PRECIPITATION WILL GRADUALLY DECREASE OVERNIGHT AS THIS
DISTURBANCE PUSHES EAST OF THE CASCADES AND HIGHER PRESSURE BUILDS
INTO THE PACIFIC NORTHWEST FRIDAY INTO THE WEEKEND. NORTHWEST FLOW
ALOFT MAY CAUSE SOME SHOWERS TO LINGER INTO THE WEEKEND ACROSS OUR
NORTHERN ZONES AS A COUPLE MORE DISTURBANCES BRUSH BY TO THE NORTH.
OTHERWISE THERE MAY BE SOME SUNBREAKS THIS WEEKEND...WITH THE BEST
CHANCE SOUTH AND OUTSIDE OF THE WILLAMETTE VALLEY. MODELS ARE SHOWING
A SYSTEM TRYING TO MOVE THROUGH THE RIDGE FOR SUNDAY NIGHT AND
MONDAY...WITH OCCASIONAL CHANCES OF PRECIPITATION CONTINUING NEXT
WEEK.
&&
.MORNING UPDATE...MADE NO CHANGES TO THE FORECAST THIS MORNING...WE
STILL LOOK ON TRACK FOR A RAINY DAY IN THE LOWLANDS WITH SNOW ABOVE
2500-3500 FEET. SO FAR SNOTEL/ODOT REPORTS INDICATE 2-6 INCHES OF
SNOW IN THE CASCADES OVERNIGHT...WITH WEBCAMS SHOWING STEADY LIGHT TO
MODERATE SNOW CONTINUING THIS MORNING. NEXT SHORTWAVE PRESENTLY
CROSSING 130W...SOMEWHAT VISIBLE ON SATELLITE IMAGERY BUT BETTER
DEFINED WITH THE RAP 850-700MB THETA-E ANALYSIS. AFTER A BRIEF LULL
EXPECT ISENTROPIC LIFT TO INCREASE AGAIN TODAY...CAUSING STEADY
VALLEY RAIN AND MTN SNOW TO INCREASE THROUGHOUT THE DAY BEFORE
TAPERING OFF THIS EVENING. OVERALL...CURRENT WINTER WX ADVISORIES
LOOK GOOD FOR THE CASCADES...THOUGH ACCUMULATIONS WILL PROBABLY BE
MARGINAL IN LANE COUNTY. WEAGLE
.SHORT TERM...TODAY THROUGH SATURDAY...THE WARM OR OCCLUDED FRONT
WITH THE SYSTEM WELL ADVERTISED BY THE MODELS HAS BEEN MOVING INTO
SOUTHWEST WASHINGTON AND NORTHWEST OREGON EARLY THIS MORNING...
MAINLY AFFECTING THE CENTRAL WILLAMETTE VALLEY NORTHWARD SO FAR. THE
MODELS SHOW THE TRAILING COLD FRONT WILL SLOWLY SAG INTO OUR
FORECAST AREA TODAY AND HELP SPREAD PRECIPITATION TO EVEN OUR
SOUTHERN FORECAST ZONES. THIS BOUNDARY THEN STALLS OVER THE OREGON
PORTION OF OUR AREA...WITH QUITE A FETCH OF MOISTURE UPSTREAM OVER
THE PACIFIC AS SEEN ON INFRARED SATELLITE IMAGERY THAT WILL RIDE
ALONG THE FRONT AND INTO OUR AREA TODAY. AS THE FRONT EASES IN...THE
NORTHERN SECTIONS...ESPECIALLY NORTH OF THE COLUMBIA RIVER WILL SEE
THE PRECIPITATION EASE LATER TODAY. THE PRECIPITATION WILL CONTINUE
IN THE OREGON SIDE OF THE FORECAST AREA INTO TONIGHT BEFORE
DECREASING LATER TONIGHT AND EARLY FRIDAY AS WELL.
HAVE MADE A FEW ADJUSTMENTS TO THE WINTER WEATHER ADVISORIES FOR
SNOW. IT APPEARS THE SOUTH WASHINGTON CASCADES SHOULD SEE THE SNOW
DIMINISH CONSIDERABLY BY 4 PM TODAY...SO HAVE MOVED UP THE ENDING
TIME OF THAT ADVISORY TO 4 PM. THE ADVISORY FOR THE NORTH OREGON
CASCADES REMAINS IN EFFECT UNTIL 10 PM TONIGHT. HAVE ISSUED A LOW
END ADVISORY FOR SNOW FOR THE LANE COUNTY CASCADES FROM LATE THIS
MORNING THROUGH MUCH OF TONIGHT AS THE FRONT SAGS INTO THE AREA AND
SNOW CONTINUES WELL INTO TONIGHT.
SNOW LEVELS WILL HOVER 2500 TO 3500 OR 4000 FEET...LOWEST IN THE
NORTH. THIS COULD BRING A LITTLE SNOW TO THE HIGHEST ELEVATIONS OF
THE CASCADE FOOTHILLS AS WELL...BUT BELIEVE AMOUNTS WILL STAY BELOW
ADVISORY CRITERIA AT THIS POINT.
THE UPPER FLOW TURNS MORE NORTHWESTERLY AND DRIES OUT LATER TONIGHT
AND FRIDAY...THOUGH THERE APPEARS ENOUGH ENERGY IN THE NORTHWEST FLOW
FOR A FEW SHOWERS THROUGH FRIDAY MAINLY AROUND THE HIGHER TERRAIN. IT
THEN LOOKS PRETTY DRY EXCEPT ANOTHER SHORT WAVE DROPS INTO WESTERN
WASHINGTON FROM THE NORTHWEST ON SATURDAY AND MAY CLIP MAINLY OUR
WASHINGTON ZONES...SO HAVE SOME LOW POPS FOR THAT. TOLLESON
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
SATURDAY NIGHT THROUGH WEDNESDAY...THE UPPER LEVEL RIDGE RESPONSIBLE
FOR THE DRYING TREND OVER THE WEEKEND SHOWS SIGNS OF BREAKING DOWN
TOWARD SUNDAY NIGHT OR MONDAY. 12Z ECMWF AND NOW 18Z GFS ARE COMING
IN LINE WITH THIS IDEA...THOUGH THEY BOTH TRY TO HANG ON TO SOME THIN
RIDGING LEFT OVER FROM A FAILED REX BLOCK OVER THE YUKON. THERE IS A
FAIR CHANCE THE REX BLOCK WILL DEVELOP AND HOLD...SO WILL KEEP POPS
BELOW CLIMO. HOWEVER WE DID BUMP THEM UP A TAD DUE TO THE MODELS
HINTING AT EITHER THE RIDGE BREAKING DOWN OR A PACIFIC STORM SYSTEM
UNDERCUTTING IT BY MIDWEEK. WEAGLE
&&
.AVIATION...STEADY LIGHT RAIN CONTINUES TODAY AS A FRONT SLOWLY
SAGS ACROSS THE AREA. CONDITIONS LIKELY REMAIN IN THE LOWER VFR
TO MVFR AT INLAND TAF SITES...WHILE COASTAL AREAS LIKELY REMAIN
IN THE MVFR TO IFR CATEGORY. EXPECT CONDITIONS TO SLOWLY IMPROVE
ACROSS THE AREA THIS AFTERNOON AND EVENING AS SHOWERS DECREASE.
MOUNTAINS FREQUENTLY OBSCURED IN CLOUDS AND PCPN THROUGH TONIGHT.
KPDX AND APPROACHES...VFR HOLDING THROUGH MOST OF THE DAY BUT
THERE IS ANOTHER BATCH OF RAIN ARRIVING LATER THIS MORNING THAT
COULD BRING SEVERAL HOURS OF MVFR CIGS.
&&
.MARINE...FRONTAL BOUNDARY WEAKENING ALONG WITH THE PRESSURE
GRADIENTS AND WILL LET ADVISORY FOR WIND EXPIRE. WEST SWELL WILL
BE SLOW TO DECAY...LIKELY REMAINING ABOVE 10 FT UNTIL FRIDAY
MORNING.
MUCH QUIETER CONDITIONS ARE EXPECTED FROM MIDDAY FRIDAY...AS HIGH
PRESSURE ESTABLISHES ITSELF INTO THE WEEKEND BRINGING LIGHTER
WINDS AND CONSIDERABLY LOWER SEAS THOUGH THE WEEKEND. A THERMAL
TROUGH WILL BE POSITIONED TO OUR SOUTH ALONG THE COAST WHICH MAY
INCREASE NORTHERLY WINDS IN THE SOUTHERN WATERS.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR
NORTHERN OREGON CASCADES.
WINTER WEATHER ADVISORY UNTIL 4 AM PST FRIDAY FOR CASCADES IN
LANE COUNTY.
WA...WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR SOUTH
WASHINGTON CASCADES.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST
FRIDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA
TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER
BAR UNTIL 10 PM PST THIS EVENING.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
704 AM EST THU FEB 20 2014
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL PENNSYLVANIA EARLY THIS MORNING WILL
SLIDE EAST AND MOVE OFF THE MID-ATLANTIC COAST BY THIS AFTERNOON.
A WARM FRONT WILL LIFT NORTH ACROSS THE AREA EARLY TONIGHT...BEFORE
A STRONG COLD FRONT RACES EAST ACROSS THE COMMONWEALTH EARLY FRIDAY.
TEMPERATURES SHOULD AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL INTO
WEEKEND BEFORE TRENDING COLDER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY AM MODIS 11-3.7UM IMAGERY SHOWING EXTENSIVE VALLEY FOG AND
STRATUS ACROSS NORTHWEST PA...THE RESULT OF CLEAR SKIES AND CALM
WIND UNDER HIGH PRES SYSTEM. LAMP AND RAP DATA BOTH INDICATE AREAS
OF FOG WILL LIFT BTWN 12Z-14Z. FOCUS WILL THEN BE ON BAND OF SHRA
LIFTING NORTHEAST FROM THE OHIO VALLEY ALONG APPROACHING WARM
FRONT. REGIONAL RADAR MOSAIC ALREADY SHOWING THIS DEVELOPING BAND
OF RAIN ACROSS ILLINOIS/INDIANA...WHERE NOSE OF LL JET INTERSECTS
RETREATING 8H BAROCLINIC ZONE. ALL NEAR TERM MDL DATA TIMES THIS
FEATURE THRU CENTRAL PA BTWN 17Z-23Z. ENSEMBLE MFLUX VALUES AND
QPF PROBS SUPPORT NEAR 100 PCT CHC OF RAIN ACROSS THE NW
MTNS...WITH PROGRESSIVELY LOWER CHC OF SHOWERS FURTHER SE.
EARLY SUNSHINE WILL FADE BEHIND LOWERING/THICKENING CLOUD COVER
TODAY. HOWEVER...A RELATIVELY MILD START TO THE DAY...COMBINED
WITH DEVELOPING SOUTHERLY FLOW WEST OF RETREATING HIGH PRES SHOULD
PUSH READINGS INTO THE 40S BY AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
A STRONG MID-LVL TROUGH ENTERING THE PLAINS STATES THIS AM IS
FCST TO TAKE ON A NEGATIVE TILT AS IT REACHES THE UPPER GRT LKS
AND MS/OH VLYS TNGT. THE MAIN SYNOPTIC FEATURE OF INTEREST WILL
BE THE SHARP/TRAILING COLD FRONT WHICH WILL BE CROSSING THE
APPLCHNS AROUND 12Z FRI. THIS FRONT IS EXPECTED TO BE A FOCUS FOR
A THIN LINE OF LOW-TOPPED CONVECTION WHICH COULD REACH THE WRN
ALLEGHENIES EARLY FRI MORNING.
SPC CONVECTIVE OUTLOOKS PLACE THE AREA IN GENERAL RISK...AND
MENTIONED THIS POTENTIAL FOR LOW TOPPED SQUALL LINE WITH ELEVATED
INSTABILITY IN HWO ALONG WITH POTENTIAL FOR GUSTY WINDS /AS VERY
POTENT LLJET DEVELOPS/. THE SYSTEM IS PROGRESSIVE WHICH WILL LIMIT
HVY RAIN POTNL/FLOOD THREAT...HOWEVER ICE JAM EFFECTS COULD BE A
CONCERN. ATTM DO NOT ANTICIPATE RAPID SNOW-MELT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A POWERFUL/NEGATIVE TILT UPPER SHORT-WAVE TROUGH WITH 200-300M/12HR
500MB HGT FALLS CROSSING THE GRT LKS/MIDWEST/TN VLY REGIONS AT THE
START OF THE PERIOD /12Z FRI/ WILL LIFT NEWD ACRS THE UPPER OH
VLY/LWR GRT LKS EARLY FRI AND CONTINUE NEWD THRU THE NORTHEAST/NEW
ENGLAND AND INTO ERN CANADA FRI NGT. AT THE SFC...AN INTENSE
OCCLUDING LOW IS FCST SIMILARLY BY THE MODELS TO SHFT NWD FROM
U.P. OF MI/LAKE SUPERIOR TO JAMES BAY. MEANWHILE...A WELL-DEFINED
TRAILING COLD FRONT EXTENDING SWD FROM TRIPLE POINT INVOF THE LWR
GRT LKS WILL RACE EWD ACRS THE APPLCHNS AND MOVE OFF THE MID-ATLC
COAST BY FRI EVE.
HIRES ARW/NMM MODEL DATA DEPICTS A SEMI-CONTINUOUS...RELATIVELY THIN
BAND OF STRONGLY FORCED LOW-TOPPED CONVECTIVE SHOWERS /WITH LITTLE
TO NO TS OR LTG/ CROSSING THE ALLEGHENY PLATEAU EARLY FRIDAY
MORNING...THEN ADVANCING QUICKLY EWD ACRS THE MID-STATE DURING THE
MID-LATE MORNING BEFORE EXITING THE ERN CWA BTWN 18-21Z. AS IS
USUALLY THE CASE WITH THESE STRONGLY FORCED COLD-SEASON
FROPAS...THERE WILL BE A RISK FOR DAMAGING WIND GUSTS
ALONG/IMMEDIATELY BEHIND THE HEAVY SHOWER BAND GIVEN VERY STRONG
WINDS ALOFT/DRY SLOT PUNCH AND MODESTLY STEEP MID-LVL LAPSE RATES.
SOUNDING DATA SHOWS A FAIRLY DEEP BLYR INVERSION IN THE PRE-
FRONTAL WARM SECTOR WHICH SHOULD BE A LIMITING FACTOR...BUT THE
STRONG FORCING/FLOW COUPLED WITH AN ISALLOBARIC PRES RISE MAX ON
THE ORDER OF 4-6MB/3HR MAY OVERCOME THE LLVL STABILITY AND PRODUCE
PEAK GUSTS IN THE 40-50 MPH RANGE. PERSISTENT..POST-FRONTAL WND
GUSTS IN THE 30-35KT RANGE SHOULD CONTINUE OVER THE WRN ZONES INTO
THE AFTN. NON-TSTM/POST-FRONTAL PEAK WND GUSTS ARE NEAR ADVY
CRITERIA...WHICH WAS CONSIDERED FOR THIS CYCLE. WILL CONTINUE TO
MENTION POTNL WIND THREAT IN THE HWO. ALTHOUGH THERE IS VERY STG
MSTR TRANSPORT/FLUX OF HI PWS VIA ANOMALOUS SLY LLJ...THE
PROGRESSIVE NATURE OF THIS SYSTEM SHOULD LIMIT QPF AMTS BTWN .5
AND 1 INCH. THESE RNFL AMTS COMBINED WITH ORDERLY SNOWMELT AND
BRIEF WARM-UP CONTINUES TO FAVOR A LOW-RISK FOR SIGNIFICANT
FLOODING...HOWEVER ICE JAM EFFECTS ALONG WITH AFOREMENTIONED
FACTORS MAY CONTRIBUTE TO MINOR/POOR DRAINAGE FLOODING IN SOME
LOCATIONS.
A SERIES OF REINFORCING FRONTS ACCOMPANYING INDIVIDUAL SHORTWAVES
ROTATING EWD AROUND THE BASE OF HUDSON/JAMES BAY POLAR VORTEX WILL
SUPPORT A GRADUAL COOL-DOWN INTO NEXT WEEK...AS THE LARGE SCALE
PATTERN REVERTS BACK TO ITS 2014 COLD SEASON FORM...WITH BLOCKING
RIDGE BECOMING REESTABLISHED OVER ALASKA AND ALLOWING A LARGE POOL
OF CONTINENTAL POLAR TO ARCTIC AIR TO BUILD OVER ERN CANADA AND
SPILL SWD INTO THE ERN U.S. THE UN-WELCOMED COOLING TREND IS THE
HIGH CONFIDENCE FCST AND SHOULD BE THE MAIN STORY INTO THE MIDDLE
OF NEXT WEEK. QUESTIONS/UNCERTAINTY REMAIN REGARDING A CLIPPER
FEATURE/COASTAL LOW DEVELOPMENT IN THE TUE-WED TIMEFRAME.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS HIGH PRES PASSES EAST OF THE AREA...EXPECT A DEVELOPING
SOUTHERLY BREEZE WILL CAUSE ANY FOG/LOW CLOUDS TO MIX OUT BTWN
12Z-14Z. LATEST LAMP/RAP OUTPUT BOTH SUPPORT THIS SCENARIO WITH A
RETURN TO WIDESPREAD VFR CONDS OVER MOST OF CENTRAL PA FOR MOST OF
THE DAYLIGHT HOURS. A BAND OF SHRA ASSOC WITH A WARM FRONT WILL
LIKELY LIFT THRU THE AREA DURING THE AFTN...AFFECTING MAINLY NW PA
WHERE MVFR REDUCTIONS ARE LIKELY AT KBFD.
A STRONG CORE OF SOUTHERLY WINDS ALOFT WILL OVERSPREAD THE REGION
THIS EVENING IN ADVANCE OF AN APPROACHING COLD FRONT. THIS WILL
LIKELY LEAD TO LLWS CRITERIA...ESP ACROSS THE W MTNS. MDL
SOUNDINGS ALSO SUPPORT THE IDEA OF WIDESPREAD MVFR /POSS IFR/ CIGS
DEVELOPING THIS EVENING IN RESPONSE TO A SURGE OF MOISTURE WORKING
INTO THE STATE ON SOUTHERLY FLOW.
COLD FRONT WILL PUSH INTO THE W MTNS BY ARND 12Z
FRIDAY...ACCOMPANIED BY SOME HEAVY SHOWERS AND PERHAPS A GUSTY
TSRA.
OUTLOOK...
FRI...WINDY. AM SHRA/LOW CIGS POSS.
SAT-MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
545 AM EST THU FEB 20 2014
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL PENNSYLVANIA EARLY THIS MORNING WILL
SLIDE EAST AND MOVE OFF THE MID-ATLANTIC COAST BY THIS AFTERNOON.
A WARM FRONT WILL LIFT NORTH ACROSS THE AREA EARLY TONIGHT...BEFORE
A STRONG COLD FRONT RACES EAST ACROSS THE COMMONWEALTH EARLY FRIDAY.
TEMPERATURES SHOULD AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL INTO
WEEKEND BEFORE TRENDING COLDER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY AM MODIS 11-3.7UM IMAGERY SHOWING EXTENSIVE VALLEY FOG AND
STRATUS ACROSS NORTHWEST PA...THE RESULT OF CLEAR SKIES AND CALM
WIND UNDER HIGH PRES SYSTEM. LAMP AND RAP DATA BOTH INDICATE AREAS
OF FOG WILL LIFT BTWN 12Z-14Z. FOCUS WILL THEN BE ON BAND OF SHRA
LIFTING NORTHEAST FROM THE OHIO VALLEY ALONG APPROACHING WARM
FRONT. REGIONAL RADAR MOSAIC ALREADY SHOWING THIS DEVELOPING BAND
OF RAIN ACROSS ILLINOIS/INDIANA...WHERE NOSE OF LL JET INTERSECTS
RETREATING 8H BAROCLINIC ZONE. ALL NEAR TERM MDL DATA TIMES THIS
FEATURE THRU CENTRAL PA BTWN 17Z-23Z. ENSEMBLE MFLUX VALUES AND
QPF PROBS SUPPORT NEAR 100 PCT CHC OF RAIN ACROSS THE NW
MTNS...WITH PROGRESSIVELY LOWER CHC OF SHOWERS FURTHER SE.
EARLY SUNSHINE WILL FADE BEHIND LOWERING/THICKENING CLOUD COVER
TODAY. HOWEVER...A RELATIVELY MILD START TO THE DAY...COMBINED
WITH DEVELOPING SOUTHERLY FLOW WEST OF RETREATING HIGH PRES SHOULD
PUSH READINGS INTO THE 40S BY AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
A STRONG MID-LVL TROUGH ENTERING THE PLAINS STATES THIS AM IS
FCST TO TAKE ON A NEGATIVE TILT AS IT REACHES THE UPPER GRT LKS
AND MS/OH VLYS TNGT. THE MAIN SYNOPTIC FEATURE OF INTEREST WILL
BE THE SHARP/TRAILING COLD FRONT WHICH WILL BE CROSSING THE
APPLCHNS AROUND 12Z FRI. THIS FRONT IS EXPECTED TO BE A FOCUS FOR
A THIN LINE OF LOW-TOPPED CONVECTION WHICH COULD REACH THE WRN
ALLEGHENIES EARLY FRI MORNING.
SPC CONVECTIVE OUTLOOKS PLACE THE AREA IN GENERAL RISK...AND
MENTIONED THIS POTENTIAL FOR LOW TOPPED SQUALL LINE WITH ELEVATED
INSTABILITY IN HWO ALONG WITH POTENTIAL FOR GUSTY WINDS /AS VERY
POTENT LLJET DEVELOPS/. THE SYSTEM IS PROGRESSIVE WHICH WILL LIMIT
HVY RAIN POTNL/FLOOD THREAT...HOWEVER ICE JAM EFFECTS COULD BE A
CONCERN. ATTM DO NOT ANTICIPATE RAPID SNOW-MELT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A POWERFUL/NEGATIVE TILT UPPER SHORT-WAVE TROUGH WITH 200-300M/12HR
500MB HGT FALLS CROSSING THE GRT LKS/MIDWEST/TN VLY REGIONS AT THE
START OF THE PERIOD /12Z FRI/ WILL LIFT NEWD ACRS THE UPPER OH
VLY/LWR GRT LKS EARLY FRI AND CONTINUE NEWD THRU THE NORTHEAST/NEW
ENGLAND AND INTO ERN CANADA FRI NGT. AT THE SFC...AN INTENSE
OCCLUDING LOW IS FCST SIMILARLY BY THE MODELS TO SHFT NWD FROM
U.P. OF MI/LAKE SUPERIOR TO JAMES BAY. MEANWHILE...A WELL-DEFINED
TRAILING COLD FRONT EXTENDING SWD FROM TRIPLE POINT INVOF THE LWR
GRT LKS WILL RACE EWD ACRS THE APPLCHNS AND MOVE OFF THE MID-ATLC
COAST BY FRI EVE.
HIRES ARW/NMM MODEL DATA DEPICTS A SEMI-CONTINUOUS...RELATIVELY THIN
BAND OF STRONGLY FORCED LOW-TOPPED CONVECTIVE SHOWERS /WITH LITTLE
TO NO TS OR LTG/ CROSSING THE ALLEGHENY PLATEAU EARLY FRIDAY
MORNING...THEN ADVANCING QUICKLY EWD ACRS THE MID-STATE DURING THE
MID-LATE MORNING BEFORE EXITING THE ERN CWA BTWN 18-21Z. AS IS
USUALLY THE CASE WITH THESE STRONGLY FORCED COLD-SEASON
FROPAS...THERE WILL BE A RISK FOR DAMAGING WIND GUSTS
ALONG/IMMEDIATELY BEHIND THE HEAVY SHOWER BAND GIVEN VERY STRONG
WINDS ALOFT/DRY SLOT PUNCH AND MODESTLY STEEP MID-LVL LAPSE RATES.
SOUNDING DATA SHOWS A FAIRLY DEEP BLYR INVERSION IN THE PRE-
FRONTAL WARM SECTOR WHICH SHOULD BE A LIMITING FACTOR...BUT THE
STRONG FORCING/FLOW COUPLED WITH AN ISALLOBARIC PRES RISE MAX ON
THE ORDER OF 4-6MB/3HR MAY OVERCOME THE LLVL STABILITY AND PRODUCE
PEAK GUSTS IN THE 40-50 MPH RANGE. PERSISTENT..POST-FRONTAL WND
GUSTS IN THE 30-35KT RANGE SHOULD CONTINUE OVER THE WRN ZONES INTO
THE AFTN. NON-TSTM/POST-FRONTAL PEAK WND GUSTS ARE NEAR ADVY
CRITERIA...WHICH WAS CONSIDERED FOR THIS CYCLE. WILL CONTINUE TO
MENTION POTNL WIND THREAT IN THE HWO. ALTHOUGH THERE IS VERY STG
MSTR TRANSPORT/FLUX OF HI PWS VIA ANOMALOUS SLY LLJ...THE
PROGRESSIVE NATURE OF THIS SYSTEM SHOULD LIMIT QPF AMTS BTWN .5
AND 1 INCH. THESE RNFL AMTS COMBINED WITH ORDERLY SNOWMELT AND
BRIEF WARM-UP CONTINUES TO FAVOR A LOW-RISK FOR SIGNIFICANT
FLOODING...HOWEVER ICE JAM EFFECTS ALONG WITH AFOREMENTIONED
FACTORS MAY CONTRIBUTE TO MINOR/POOR DRAINAGE FLOODING IN SOME
LOCATIONS.
A SERIES OF REINFORCING FRONTS ACCOMPANYING INDIVIDUAL SHORTWAVES
ROTATING EWD AROUND THE BASE OF HUDSON/JAMES BAY POLAR VORTEX WILL
SUPPORT A GRADUAL COOL-DOWN INTO NEXT WEEK...AS THE LARGE SCALE
PATTERN REVERTS BACK TO ITS 2014 COLD SEASON FORM...WITH BLOCKING
RIDGE BECOMING REESTABLISHED OVER ALASKA AND ALLOWING A LARGE POOL
OF CONTINENTAL POLAR TO ARCTIC AIR TO BUILD OVER ERN CANADA AND
SPILL SWD INTO THE ERN U.S. THE UN-WELCOMED COOLING TREND IS THE
HIGH CONFIDENCE FCST AND SHOULD BE THE MAIN STORY INTO THE MIDDLE
OF NEXT WEEK. QUESTIONS/UNCERTAINTY REMAIN REGARDING A CLIPPER
FEATURE/COASTAL LOW DEVELOPMENT IN THE TUE-WED TIMEFRAME.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
EARLY AM SATL IMAGERY SHOWS VALLEY FOG HAS FORMED ACROSS THE NW
MTNS. ANOTHER COUPLE HOURS OF RADIATIONAL COOLING SHOULD ENSURE
THAT LOW CLOUDS/FOG PERSIST AT KBFD THRU THE NEXT FEW HOURS.
ELSEWHERE...CONDITIONAL CLIMATOLOGY BASED ON 09Z SFC OBS SUGGEST
THERE IS ARND A 40 PCT CHC OF KUNV AND KAOO BRIEFING DIPPING TO
IFR ARND 12Z.
AS HIGH PRES PASSES EAST OF THE AREA...EXPECT A DEVELOPING
SOUTHERLY BREEZE TO CAUSE ANY FOG TO LIFT BTWN 12Z-14Z. LATEST
LAMP/RAP OUTPUT BOTH SUPPORT THIS SCENARIO WITH A RETURN TO
WIDESPREAD VFR CONDS OVER MOST OF CENTRAL PA FOR MOST OF THE
DAYLIGHT HOURS. A BAND OF SHRA ASSOC WITH A WARM FRONT WILL LIKELY
LIFT THRU THE AREA DURING THE AFTN...AFFECTING MAINLY NW PA WHERE
MVFR REDUCTIONS ARE LIKELY AT KBFD.
A STRONG CORE OF SOUTHERLY WINDS ALOFT WILL OVERSPREAD THE REGION
THIS EVENING IN ADVANCE OF AN APPROACHING COLD FRONT. THIS WILL
LIKELY LEAD TO LLWS CRITERIA...ESP ACROSS THE W MTNS. MDL
SOUNDINGS ALSO SUPPORT THE IDEA OF WIDESPREAD MVFR /POSS IFR/ CIGS
DEVELOPING THIS EVENING IN RESPONSE TO A SURGE OF MOISTURE WORKING
INTO THE STATE ON SOUTHERLY FLOW.
OUTLOOK...
FRI...WINDY. AM SHRA/LOW CIGS POSS.
SAT-MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
456 AM EST THU FEB 20 2014
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL PENNSYLVANIA EARLY THIS MORNING WILL
SLIDE EAST AND MOVE OFF THE MID-ATLANTIC COAST BY THIS AFTERNOON.
A WARM FRONT WILL LIFT NORTH ACROSS THE AREA EARLY TONIGHT...BEFORE
A STRONG COLD FRONT RACES EAST ACROSS THE COMMONWEALTH EARLY FRIDAY.
TEMPERATURES SHOULD AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL INTO
WEEKEND BEFORE TRENDING COLDER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY AM MODIS 11-3.7UM IMAGERY SHOWING EXTENSIVE VALLEY FOG AND
STRATUS ACROSS NORTHWEST PA...THE RESULT OF CLEAR SKIES AND CALM
WIND UNDER HIGH PRES SYSTEM. LAMP AND RAP DATA BOTH INDICATE AREAS
OF FOG WILL LIFT BTWN 12Z-14Z. FOCUS WILL THEN BE ON BAND OF SHRA
LIFTING NORTHEAST FROM THE OHIO VALLEY ALONG APPROACHING WARM
FRONT. REGIONAL RADAR MOSAIC ALREADY SHOWING THIS DEVELOPING BAND
OF RAIN ACROSS ILLINOIS/INDIANA...WHERE NOSE OF LL JET INTERSECTS
RETREATING 8H BAROCLINIC ZONE. ALL NEAR TERM MDL DATA TIMES THIS
FEATURE THRU CENTRAL PA BTWN 17Z-23Z. ENSEMBLE MFLUX VALUES AND
QPF PROBS SUPPORT NEAR 100 PCT CHC OF RAIN ACROSS THE NW
MTNS...WITH PROGRESSIVELY LOWER CHC OF SHOWERS FURTHER SE.
EARLY SUNSHINE WILL FADE BEHIND LOWERING/THICKENING CLOUD COVER
TODAY. HOWEVER...A RELATIVELY MILD START TO THE DAY...COMBINED
WITH DEVELOPING SOUTHERLY FLOW WEST OF RETREATING HIGH PRES SHOULD
PUSH READINGS INTO THE 40S BY AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
A STRONG MID-LVL TROUGH ENTERING THE PLAINS STATES THIS AM IS
FCST TO TAKE ON A NEGATIVE TILT AS IT REACHES THE UPPER GRT LKS
AND MS/OH VLYS TNGT. THE MAIN SYNOPTIC FEATURE OF INTEREST WILL
BE THE SHARP/TRAILING COLD FRONT WHICH WILL BE CROSSING THE
APPLCHNS AROUND 12Z FRI. THIS FRONT IS EXPECTED TO BE A FOCUS FOR
A THIN LINE OF LOW-TOPPED CONVECTION WHICH COULD REACH THE WRN
ALLEGHENIES EARLY FRI MORNING.
SPC CONVECTIVE OUTLOOKS PLACE THE AREA IN GENERAL RISK...AND
MENTIONED THIS POTENTIAL FOR LOW TOPPED SQUALL LINE WITH ELEVATED
INSTABILITY IN HWO ALONG WITH POTENTIAL FOR GUSTY WINDS /AS VERY
POTENT LLJET DEVELOPS/. THE SYSTEM IS PROGRESSIVE WHICH WILL LIMIT
HVY RAIN POTNL/FLOOD THREAT...HOWEVER ICE JAM EFFECTS COULD BE A
CONCERN. ATTM DO NOT ANTICIPATE RAPID SNOW-MELT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS COLD FRONT SLIDES ACROSS ON FRI...PRECIP WILL PUSH EASTWARD
AND COOLER AIR WILL FILTER BACK INTO THE REGION. GFS/ECMWF NOW IN
QUITE GOOD ALIGNMENT WITH MAIN FEATURES AS THIS SYSTEM
EVOLVES...WITH PRECIP ENDING BY LUNCHTIME FRI.
AFTER THAT...BROAD TROUGH BECOMES MORE AND MORE ENTRENCHED ACROSS
EASTERN 2/3RDS OF U.S. THROUGH NEXT MIDWEEK...GIVING US A SLOW
AND STEADY RETURN BACK TO BELOW NORMAL TEMPERATURES. FOR THE
UPCOMING WEEKEND...WEAK FRONT PUSHES THROUGH THAT MAY BRING LIGHT
ACCUMS OF SNOW. OTHERWISE...NO BIG SYSTEMS THROUGH TUE AS
PERSISTENT NW FLOW CONTINUES WHILE HUDSON BAY LOW GRADUALLY
DEEPENS AND PUSHES COLDER AIR FURTHER SOUTHWARD. SNOWFLAKES WILL
LINGER OVER THE WESTERN/NORTHERN HIGHER TERRAIN.
NOTABLE WAVE PROGGED TO SWING AROUND THE TROUGH NEXT MIDWEEK...AND
LONG RANGE MODELS /BOTH ECMWF AND GFS/ BEGINNING TO HINT AT
POTENTIAL LOW DEVELOPMENT AS IT SLIDES OFF THE EAST COAST. BUT THAT
REMAINS A LONG WAY OFF FOR NOW.
AS FAR AS THE SNOW COVER AND RIVER ICE...WARMING TREND LATE THIS
WEEK WILL BE FAIRLY SHORT-LIVED...SO MELTING OF SNOW AND ICE WILL
REMAIN GRADUAL...WHICH SHOULD KEEP POTENTIAL FOR WIDESPREAD
PROBLEMS LOW.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
EARLY AM SATL IMAGERY SHOWS VALLEY FOG HAS FORMED ACROSS THE NW
MTNS. ANOTHER COUPLE HOURS OF RADIATIONAL COOLING SHOULD ENSURE
THAT LOW CLOUDS/FOG PERSIST AT KBFD THRU THE NEXT FEW HOURS.
ELSEWHERE...CONDITIONAL CLIMATOLOGY BASED ON 09Z SFC OBS SUGGEST
THERE IS ARND A 40 PCT CHC OF KUNV AND KAOO BRIEFING DIPPING TO
IFR ARND 12Z.
AS HIGH PRES PASSES EAST OF THE AREA...EXPECT A DEVELOPING
SOUTHERLY BREEZE TO CAUSE ANY FOG TO LIFT BTWN 12Z-14Z. LATEST
LAMP/RAP OUTPUT BOTH SUPPORT THIS SCENARIO WITH A RETURN TO
WIDESPREAD VFR CONDS OVER MOST OF CENTRAL PA FOR MOST OF THE
DAYLIGHT HOURS. A BAND OF SHRA ASSOC WITH A WARM FRONT WILL LIKELY
LIFT THRU THE AREA DURING THE AFTN...AFFECTING MAINLY NW PA WHERE
MVFR REDUCTIONS ARE LIKELY AT KBFD.
A STRONG CORE OF SOUTHERLY WINDS ALOFT WILL OVERSPREAD THE REGION
THIS EVENING IN ADVANCE OF AN APPROACHING COLD FRONT. THIS WILL
LIKELY LEAD TO LLWS CRITERIA...ESP ACROSS THE W MTNS. MDL
SOUNDINGS ALSO SUPPORT THE IDEA OF WIDESPREAD MVFR /POSS IFR/ CIGS
DEVELOPING THIS EVENING IN RESPONSE TO A SURGE OF MOISTURE WORKING
INTO THE STATE ON SOUTHERLY FLOW.
OUTLOOK...
FRI...WINDY. AM SHRA/LOW CIGS POSS.
SAT-MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
436 AM EST THU FEB 20 2014
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL PENNSYLVANIA EARLY THIS MORNING WILL
SLIDE EAST AND MOVE OFF THE MID-ATLANTIC COAST BY THIS AFTERNOON.
A WARM FRONT WILL LIFT NORTH ACROSS THE AREA EARLY TONIGHT...BEFORE
A STRONG COLD FRONT RACES EAST ACROSS THE COMMONWEALTH EARLY FRIDAY.
TEMPERATURES SHOULD AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL INTO
WEEKEND BEFORE TRENDING COLDER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY AM MODIS 11-3.7UM IMAGERY SHOWING EXTENSIVE VALLEY FOG AND
STRATUS ACROSS NORTHWEST PA...THE RESULT OF CLEAR SKIES AND CALM
WIND UNDER HIGH PRES SYSTEM. LAMP AND RAP DATA BOTH INDICATE AREAS
OF FOG WILL LIFT BTWN 12Z-14Z. FOCUS WILL THEN BE ON BAND OF SHRA
LIFTING NORTHEAST FROM THE OHIO VALLEY ALONG APPROACHING WARM
FRONT. REGIONAL RADAR MOSAIC ALREADY SHOWING THIS DEVELOPING BAND
OF RAIN ACROSS ILLINOIS/INDIANA...WHERE NOSE OF LL JET INTERSECTS
RETREATING 8H BAROCLINIC ZONE. ALL NEAR TERM MDL DATA TIMES THIS
FEATURE THRU CENTRAL PA BTWN 17Z-23Z. ENSEMBLE MFLUX VALUES AND
QPF PROBS SUPPORT NEAR 100 PCT CHC OF RAIN ACROSS THE NW
MTNS...WITH PROGRESSIVELY LOWER CHC OF SHOWERS FURTHER SE.
EARLY SUNSHINE WILL FADE BEHIND LOWERING/THICKENING CLOUD COVER
TODAY. HOWEVER...A RELATIVELY MILD START TO THE DAY...COMBINED
WITH DEVELOPING SOUTHERLY FLOW WEST OF RETREATING HIGH PRES SHOULD
PUSH READINGS INTO THE 40S BY AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
A STRONG MID-LVL TROUGH ENTERING THE PLAINS STATES THIS AM IS
FCST TO TAKE ON A NEGATIVE TILT AS IT REACHES THE UPPER GRT LKS
AND MS/OH VLYS TNGT. THE MAIN SYNOPTIC FEATURE OF INTEREST WILL
BE THE SHARP/TRAILING COLD FRONT WHICH WILL BE CROSSING THE
APPLCHNS AROUND 12Z FRI. THIS FRONT IS EXPECTED TO BE A FOCUS FOR
A THIN LINE OF LOW-TOPPED CONVECTION WHICH COULD REACH THE WRN
ALLEGHENIES EARLY FRI MORNING.
SPC CONVECTIVE OUTLOOKS PLACE THE AREA IN GENERAL RISK...AND
MENTIONED THIS POTENTIAL FOR LOW TOPPED SQUALL LINE WITH ELEVATED
INSTABILITY IN HWO ALONG WITH POTENTIAL FOR GUSTY WINDS /AS VERY
POTENT LLJET DEVELOPS/. THE SYSTEM IS PROGRESSIVE WHICH WILL LIMIT
HVY RAIN POTNL/FLOOD THREAT...HOWEVER ICE JAM EFFECTS COULD BE A
CONCERN. ATTM DO NOT ANTICIPATE RAPID SNOW-MELT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS COLD FRONT SLIDES ACROSS ON FRI...PRECIP WILL PUSH EASTWARD
AND COOLER AIR WILL FILTER BACK INTO THE REGION. GFS/ECMWF NOW IN
QUITE GOOD ALIGNMENT WITH MAIN FEATURES AS THIS SYSTEM
EVOLVES...WITH PRECIP ENDING BY LUNCHTIME FRI.
AFTER THAT...BROAD TROUGH BECOMES MORE AND MORE ENTRENCHED ACROSS
EASTERN 2/3RDS OF U.S. THROUGH NEXT MIDWEEK...GIVING US A SLOW
AND STEADY RETURN BACK TO BELOW NORMAL TEMPERATURES. FOR THE
UPCOMING WEEKEND...WEAK FRONT PUSHES THROUGH THAT MAY BRING LIGHT
ACCUMS OF SNOW. OTHERWISE...NO BIG SYSTEMS THROUGH TUE AS
PERSISTENT NW FLOW CONTINUES WHILE HUDSON BAY LOW GRADUALLY
DEEPENS AND PUSHES COLDER AIR FURTHER SOUTHWARD. SNOWFLAKES WILL
LINGER OVER THE WESTERN/NORTHERN HIGHER TERRAIN.
NOTABLE WAVE PROGGED TO SWING AROUND THE TROUGH NEXT MIDWEEK...AND
LONG RANGE MODELS /BOTH ECMWF AND GFS/ BEGINNING TO HINT AT
POTENTIAL LOW DEVELOPMENT AS IT SLIDES OFF THE EAST COAST. BUT THAT
REMAINS A LONG WAY OFF FOR NOW.
AS FAR AS THE SNOW COVER AND RIVER ICE...WARMING TREND LATE THIS
WEEK WILL BE FAIRLY SHORT-LIVED...SO MELTING OF SNOW AND ICE WILL
REMAIN GRADUAL...WHICH SHOULD KEEP POTENTIAL FOR WIDESPREAD
PROBLEMS LOW.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
MCLEAR SKIES AND LGT WIND UNDERNEATH HIGH PRES SYSTEM WILL PRODUCE
CONDS FAVORABLE FOR PATCHY RADIATION FOG EARLY THIS MORNING. BASED
ON 06Z DWPT DEPRESSIONS...KBFD APPEARS MOST SUSCEPTIBLE TO A
PERIOD OF IFR VSBYS EARLY THIS AM. HOWEVER...THICKENING CIRRUS
APPROACHING FROM NORTHERN OHIO COMPLICATES MATTERS AND COULD
MITIGATE THE FOG THREAT. ELSEWHERE...SREF AND OPER MDL SFC RH
FIELDS SUGGEST A DIMINISHING WIND COULD PRODUCE A BRIEF PERIOD OF
FOG ARND KMDT/KLNS ARND 12Z.
ANY PATCHY FOG SHOULD LIFT BTWN 12Z-14Z...WITH WIDESPREAD VFR
CONDS EXPECTED OVER MOST OF CENTRAL PA FOR MOST OF THE DAYLIGHT
HOURS. A BAND OF SHRA ASSOC WITH A WARM FRONT WILL LIKELY LIFT
THRU THE AREA DURING THE AFTN...AFFECTING MAINLY NW PA WHERE MVFR
REDUCTIONS ARE LIKELY AT KBFD.
A STRONG CORE OF SOUTHERLY WINDS ALOFT WILL OVERSPREAD THE REGION
THIS EVENING IN ADVANCE OF AN APPROACHING COLD FRONT. THIS WILL
LIKELY LEAD TO LLWS CRITERIA...ESP ACROSS THE W MTNS. MDL
SOUNDINGS ALSO SUPPORT THE IDEA OF WIDESPREAD MVFR /POSS IFR/ CIGS
DEVELOPING THIS EVENING IN RESPONSE TO A SURGE OF MOISTURE WORKING
INTO THE STATE ON SOUTHERLY FLOW.
OUTLOOK...
FRI...WINDY. AM SHRA/LOW CIGS POSS.
SAT-MON...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/STEINBUGL
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
447 PM CST THU FEB 20 2014
.DISCUSSION...
UPDATED TO BREAK OUT LATE AFTERNOON GROUPING IN THE ZONE FORECAST
PRODUCT FOR GREATER CLARIFICATION FOR FORECAST THROUGH LATE
AFTERNOON HOURS AND FOR TONIGHT.
&&
.PREV DISCUSSION.../ISSUED 348 PM CST THU FEB 20 2014/
..POTENTIAL FOR SEVERE THUNDERSTORMS THIS EVENING AND TONIGHT AS
STRONG COLD FRONT SWEEPS THROUGH...
SHORT TERM...AS OF 330 PM, THUNDERSTORMS WERE ALREADY DEVELOPING
OVER THE EXTREME NORTHWESTERN PART OF OUR CWA. INTERMEDIATE 20Z
OHX SOUNDING STILL SHOWED A WARM NOSE AROUND 700MB, AS DID THE
EARLIER 12Z SOUNDING. HOWEVER, FORECAST RUC SOUNDINGS CONTINUE TO
SUGGEST AN EROSION OF THE INHIBITING NOSE THROUGH OUR NORTHWESTERN
COUNTIES, AS INDICATED BY THE ONGOING THUNDERSTORMS.
RECORD WARMTH WAS RECORDED OVER THE MID STATE TODAY, WITH
NASHVILLE EQUALING A RECORD HIGH OF 78 DEGREES. WINDS CONTINUE TO
GUST TO BETWEEN 35 AND 40 MPH OVER OUR WESTERN COUNTIES, IN
ADVANCE OF THE STORMS.
A TORNADO WATCH IS IN EFFECT UNTIL 9PM FOR OUR MOST WESTERN
COUNTIES, AND IT WOULD NOT BE SURPRISING TO SEE SEVERE WEATHER
WATCHES EXTENDED INTO OTHER PARTS OF THE MID STATE LATER THIS
EVENING.
STILL LOOKS LIKE THE STRONG COLD FRONT, NOW LOCATED BACK OVER
SOUTHEASTERN MISSOURI, WILL SWEEP RAPIDLY EASTWARD ACROSS THE MID
STATE BETWEEN 00Z AND 06Z THIS EVENING, WITH AN ATTENDANT SQUALL
LINE, AND THE EXPECTATION FOR SOME DAMAGING STRAIGHT LINE WINDS,
LARGE HAIL, AND POSSIBLY A FEW TORNADOES AS WELL.
THERE WILL BE A SLIGHT CHANCE FOR LINGERING SHOWERS IN THE
MORNING, ALONG THE CUMBERLAND PLATEAU. OTHERWISE, TOMORROW SHOULD
BRING SOME DRIER AND MUCH QUIETER WEATHER, WITH AFTERNOON HIGHS
IN THE 50S.
UNSEASONABLY MILD TEMPERATURES REMAIN OVER THE UPCOMING WEEKEND,
WITH DAYTIME HIGHS FORECAST TO BE IN THE 60S BOTH SATURDAY AND
SUNDAY.
LONG TERM...A GENERAL COOL DOWN OCCURS NEXT WEEK, WITH HIGHS
FALLING TO THE 40S AND 50S MONDAY AND TUESDAY AND INTO THE 40S FOR
WEDNESDAY AND THURSDAY. HAVE TRENDED TOWARD THE COOLER ECMWF FOR
THE LATTER PERIODS, AS BOTH GFS AND ECMWF SUGGEST SOME PRETTY GOOD
DEEPENING OF UPPER TROUGH BY NEXT WEDNESDAY AND THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 41 57 34 64 / 100 0 05 05
CLARKSVILLE 37 56 36 59 / 100 0 05 05
CROSSVILLE 39 51 32 59 / 100 20 05 05
COLUMBIA 40 57 34 65 / 100 0 05 05
LAWRENCEBURG 40 58 32 65 / 100 0 05 05
WAVERLY 39 57 35 62 / 100 0 05 05
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR TNZ009>011-029>034-
063>066-077>080.
WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR TNZ005>008-023>028-
056>062-075-093>095.
&&
$$
31
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
348 PM CST THU FEB 20 2014
...POTENTIAL FOR SEVERE THUNDERSTORMS THIS EVENING AND TONIGHT AS
STRONG COLD FRONT SWEEPS THROUGH...
.SHORT TERM...AS OF 330 PM, THUNDERSTORMS WERE ALREADY DEVELOPING
OVER THE EXTREME NORTHWESTERN PART OF OUR CWA. INTERMEDIATE 20Z
OHX SOUNDING STILL SHOWED A WARM NOSE AROUND 700MB, AS DID THE
EARLIER 12Z SOUNDING. HOWEVER, FORECAST RUC SOUNDINGS CONTINUE TO
SUGGEST AN EROSION OF THE INHIBITING NOSE THROUGH OUR NORTHWESTERN
COUNTIES, AS INDICATED BY THE ONGOING THUNDERSTORMS.
RECORD WARMTH WAS RECORDED OVER THE MID STATE TODAY, WITH
NASHVILLE EQUALING A RECORD HIGH OF 78 DEGREES. WINDS CONTINUE TO
GUST TO BETWEEN 35 AND 40 MPH OVER OUR WESTERN COUNTIES, IN
ADVANCE OF THE STORMS.
A TORNADO WATCH IS IN EFFECT UNTIL 9PM FOR OUR MOST WESTERN
COUNTIES, AND IT WOULD NOT BE SURPRISING TO SEE SEVERE WEATHER
WATCHES EXTENDED INTO OTHER PARTS OF THE MID STATE LATER THIS
EVENING.
STILL LOOKS LIKE THE STRONG COLD FRONT, NOW LOCATED BACK OVER
SOUTHEASTERN MISSOURI, WILL SWEEP RAPIDLY EASTWARD ACROSS THE MID
STATE BETWEEN 00Z AND 06Z THIS EVENING, WITH AN ATTENDANT SQUALL
LINE, AND THE EXPECTATION FOR SOME DAMAGING STRAIGHT LINE WINDS,
LARGE HAIL, AND POSSIBLY A FEW TORNADOES AS WELL.
THERE WILL BE A SLIGHT CHANCE FOR LINGERING SHOWERS IN THE
MORNING, ALONG THE CUMBERLAND PLATEAU. OTHERWISE, TOMORROW SHOULD
BRING SOME DRIER AND MUCH QUIETER WEATHER, WITH AFTERNOON HIGHS
IN THE 50S.
UNSEASONABLY MILD TEMPERATURES REMAIN OVER THE UPCOMING WEEKEND,
WITH DAYTIME HIGHS FORECAST TO BE IN THE 60S BOTH SATURDAY AND
SUNDAY.
.LONG TERM...A GENERAL COOL DOWN OCCURS NEXT WEEK, WITH HIGHS
FALLING TO THE 40S AND 50S MONDAY AND TUESDAY AND INTO THE 40S FOR
WEDNESDAY AND THURSDAY. HAVE TRENDED TOWARD THE COOLER ECMWF FOR
THE LATTER PERIODS, AS BOTH GFS AND ECMWF SUGGEST SOME PRETTY GOOD
DEEPENING OF UPPER TROUGH BY NEXT WEDNESDAY AND THURSDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR TNZ009>011-029>034-
063>066-077>080.
WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR TNZ005>008-023>028-
056>062-075-093>095.
&&
$$
19
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1139 AM CST THU FEB 20 2014
.UPDATE FOR AVIATION...
UPDATED FOR THE 18Z AVIATION DISCUSSION.
&&
.DISCUSSION... /ISSUED 1006 AM CST THU FEB 20 2014/
SKIES ARE MOSTLY CLOUDY ACROSS THE FORECAST AREA THIS MORNING
WITH TEMPERATURES FROM THE MID 60S TO LOWER 70S. SURFACE LOW
CURRENTLY NEAR KANSAS/MISSOURI BORDER WITH COLD FRONT EXTENDING
SOUTH FROM THE LOW THROUGH EASTERN OKLAHOMA AND INTO CENTRAL
TEXAS. THERE IS NOT MUCH IN THE WAY OF THUNDERSTORM DEVELOPMENT AT
THIS TIME BUT AS THE FRONT MOVES INTO WESTERN ARKANSAS
THUNDERSTORMS WILL BEGIN TO DEVELOP. WILL UPDATE FORECAST TO
REMOVE MORNING WORDING BUT NO BIG CHANGES ARE NEEDED AT THIS TIME.
ARS
PREV DISCUSSION... /ISSUED 557 AM CST THU FEB 20 2014/
A SIGNIFICANT COLD FRONT WILL BRING SEVERE WEATHER TO THE ENTIRE
MID-SOUTH THIS AFTERNOON AND INTO THIS EVENING...
SYNOPSIS...CURRENT GOES WATER VAPOR IMAGERY SHOWS A SIGNIFICANT
LONGWAVE TROUGH DIGGING ACROSS THE CENTRAL PLAINS THIS MORNING.
THIS TROUGH WILL CONTINUE TO DEEPEN AND ACQUIRE A NEGATIVE TILT AS
IT PUSHES INTO THE MID MISSISSIPPI VALLEY THIS AFTERNOON. LATEST
SURFACE ANALYIS SHOWS AN ASSOCIATED AND IMPRESSIVE 992MB DEEPENING
LOW PRESSURE SYSTEM LOCATED JUST TO THE NORTH OF THE OKLAHOMA
PANHANDLE. THIS SURFACE CYCLONE IS EXPECTED TO TRACK NORTHEAST
THROUGH NORTHERN MISSOURI THIS AFTERNOON...AND INTO THE
GREAT LAKES REGION BY THIS EVENING. SURFACE DEWPOINTS ACROSS THE
SOUTH RANGE FROM MID TO UPPER 50S TO MID 60S AS A WARM FRONT
CONTINUES TO PUSH NORTH. THIS SYSTEM IS EXPECTED TO BECOME
OCCLUDED JUST AS IT ARRIVES INTO THE MID-SOUTH. THIS ENVIRONMENT
WILL SET THE STAGE FOR A STRONG SQUALL LINE OF THUNDERSTORMS ALONG
THE COLD FRONT TO PUSH THROUGH THIS AFTERNOON INTO TONIGHT.
IN RESPECT TO TIMING AND THREATS...
THE INITIAL CONVECTIVE MODE IS EXPECTED TO BE MIXED AND THEN
TRANSITION INTO A LINEAR MODE BY 4 PM OR SO JUST AS IT ARRIVES AT
THE MISSISSIPPI RIVER.
PREDOMINANTLY WEST OF THE MISSISSIPPI RIVER...IN THE WARM SECTOR AHEAD
OF THE COLD FRONT...LATEST HRRR MODEL SHOWS SOME ISOLATED CELLS
FORMING BY EARLY AFTERNOON AS THE MODERATE UPPER LEVEL HEIGHT FALLS ARE
OCCURRING. WITH LATEST GUIDANCE SUGGESTING ABOUT 800-1000 J/KG
SBCAPE...60 KTS OF BULK SHEAR...AND A WEAK CAP IN PLACE
CONVECTION WILL INITIATE. THIS WILL ALLOW SOME ISOLATED CELLS TO
DEVELOP JUST AHEAD OF THE FRONT. SEMI-DISCREET SUPERCELLS AS WELL
AS SOME BOWING SEGMENTS WILL BE POSSIBLE. A FEW TORNADOES
ALONG WITH DAMAGING WINDS WILL BE THE PRIMARY THREAT.
BY LATE AFTERNOON ...THE COLD FRONT WILL CATCH UP TO THE PREFRONTAL
CONVECTION AND TRANSITION INTO A IMPRESSIVE QLCS (SQUALL LINE).
THIS IS WHEN DAMAGING WINDS WILL BECOME THE PRIMARY THREAT.
DAMAGING WINDS MAY BECOME WIDESPREAD EAST OF THE MISSISSIPPI RIVER
ALONG WITH A FEW SIGNIFICANT WIND GUSTS IN EXCESS OF 70MPH. AS THE
LINE MOVES EASTWARD...SOME EMBEDDED MESOVORTICES WITHIN THE QLCS
MAY POSE AN ISOLATED TORNADO RISK. ANY TORNADOES EMBEDDED WITHIN
THE LINE SHOULD BE SHORT TRACKED. THE SEVERE LINE SHOULD DEPART
EASTERN AREAS OF THE CWA BY LATE EVENING.
LONG TERM...FRIDAY THROUGH NEXT WEEK...
AFTER THE COLD FRONT MOVES THROUGH THIS EVENING...HIGH PRESSURE
WILL BUILD INTO THE REGION AND BRING A RETURN TO DRY WEATHER AND
CONTINUED MILD TEMPERATURES. THIS PLEASANT WEATHER SHOULD
CONTINUE FROM FRIDAY THROUGH THE FIRST HALF OF THE WEEKEND.
A COLD FRONT WILL MOVE THROUGH THE MID SOUTH ON SUNDAY BRINGING A
RETURN TO COOLER TEMPERATURES. DRY CONDITIONS SHOULD CONTINUE INTO
EARLY NEXT WEEK WITH TEMPERATURES RETURNING TO NEAR OR SLIGHTLY
BELOW AVERAGE. ANOTHER REINFORCING COLD FRONT WILL MOVE THROUGH ON
TUESDAY WITH LIGHT PRECIPITATION CHANCES AND COLDER TEMPERATURES.
AC3
&&
.AVIATION...
18Z TAF CYCLE
TIGHTENING PRESSURE GRADIENT AS LOW DEEPENS OVER MO AHEAD OF
ADVANCING COLD FRONT. THIS TRANSLATES INTO STRONG SOUTHERLY WINDS
CURRENTLY AT ALL TERMINALS AHEAD OF THE COLD FRONTAL PASSAGE.
SUSTAINED WINDS EXPECTED TO CONTINUE 20-25KT...WITH GUSTS POSSIBLE
BETWEEN 35-40 KTS.
PATCHY MVFR CIGS MAINLY BTN 2500-3000FT CONT AT MAINLY OVR THE NE
PORTION OF THE REGION WITH MORE BREAKS AND VFR TO THE SE. CIGS
SHOULD CONT TO LIFT SLOWLY UNTIL THUNDERSTORM ACTIVITY BEGINS TO
DEVELOP ALONG AND IN ADVANCE OF COLD FRONT.
STORMS HAVE RECENTLY BEGUN TO DEVELOP IN NE TX WHERE CAPPING IS A
BIT WEAKER. EXPECT THIS TREND TO CONTINUE...WITH STORMS DVLPG OVR AR
DURING THE 19-21Z RANGE. STORMS SHOULD CONSOLIDATE INTO A MORE
SOLID LINE BY LATE AFTERNOON...IMPACTING KMEM BETWEEN
20/21Z-21/00Z. THIS LINE WILL RACE EAST AND SHOULD IMPACT KMKL
BETWEEN 20/22Z-21/01Z AND KTUP BETWEEN 21/00Z-21/02Z. DAMAGING
WIND GUSTS WILL BE POSSIBLE...ESPECIALLY EAST OF THE MISSISSIPPI
RIVER. VSBYS MAY BE REDUCED TO IFR DURING ANY STRONG CONVECTION.
WINDS WILL SWITCH NORTHWESTERLY BEHIND THE CONVECTIVE LINE AND
BECOME MORE WESTERLY LATE TONIGHT AS SKIES EVENTUALLY
CLEAR. CLEAR SKIES AND WEST WINDS 5-10KT EXPECTED TO CONTINUE THRU
18Z FRI.
NGU
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 74 40 62 41 / 100 50 0 0
MKL 75 37 61 36 / 90 70 0 0
JBR 72 35 59 37 / 60 10 0 0
TUP 77 40 62 37 / 60 100 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR DUNKLIN-PEMISCOT.
MS...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR ALCORN-BENTON MS-
CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-
TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.
TN...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR BENTON TN-CARROLL-
CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-
HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-
MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1006 AM CST THU FEB 20 2014
.DISCUSSION...
SKIES ARE MOSTLY CLOUDY ACROSS THE FORECAST AREA THIS MORNING WITH
TEMPERATURES FROM THE MID 60S TO LOWER 70S. SURFACE LOW CURRENTLY
NEAR KANSAS/MISSOURI BORDER WITH COLD FRONT EXTENDING SOUTH FROM
THE LOW THROUGH EASTERN OKLAHOMA AND INTO CENTRAL TEXAS. THERE IS
NOT MUCH IN THE WAY OF THUNDERSTORM DEVELOPMENT AT THIS TIME BUT
AS THE FRONT MOVES INTO WESTERN ARKANSAS THUNDERSTORMS WILL BEGIN
TO DEVELOP. WILL UPDATE FORECAST TO REMOVE MORNING WORDING BUT NO
BIG CHANGES ARE NEEDED AT THIS TIME.
ARS
&&
.PREV DISCUSSION... /ISSUED 557 AM CST THU FEB 20 2014/
DISCUSSION...
..A SIGNIFICANT COLD FRONT WILL BRING SEVERE WEATHER TO THE ENTIRE
MID-SOUTH THIS AFTERNOON AND INTO THIS EVENING...
SYNOPSIS...CURRENT GOES WATER VAPOR IMAGERY SHOWS A SIGNIFICANT
LONGWAVE TROUGH DIGGING ACROSS THE CENTRAL PLAINS THIS MORNING.
THIS TROUGH WILL CONTINUE TO DEEPEN AND ACQUIRE A NEGATIVE TILT AS
IT PUSHES INTO THE MID MISSISSIPPI VALLEY THIS AFTERNOON. LATEST
SURFACE ANALYIS SHOWS AN ASSOCIATED AND IMPRESSIVE 992MB DEEPENING
LOW PRESSURE SYSTEM LOCATED JUST TO THE NORTH OF THE OKLAHOMA
PANHANDLE. THIS SURFACE CYCLONE IS EXPECTED TO TRACK NORTHEAST
THROUGH NORTHERN MISSOURI THIS AFTERNOON...AND INTO THE
GREAT LAKES REGION BY THIS EVENING. SURFACE DEWPOINTS ACROSS THE
SOUTH RANGE FROM MID TO UPPER 50S TO MID 60S AS A WARM FRONT
CONTINUES TO PUSH NORTH. THIS SYSTEM IS EXPECTED TO BECOME
OCCLUDED JUST AS IT ARRIVES INTO THE MID-SOUTH. THIS ENVIRONMENT
WILL SET THE STAGE FOR A STRONG SQUALL LINE OF THUNDERSTORMS ALONG
THE COLD FRONT TO PUSH THROUGH THIS AFTERNOON INTO TONIGHT.
IN RESPECT TO TIMING AND THREATS...
THE INITIAL CONVECTIVE MODE IS EXPECTED TO BE MIXED AND THEN
TRANSITION INTO A LINEAR MODE BY 4 PM OR SO JUST AS IT ARRIVES AT
THE MISSISSIPPI RIVER.
PREDOMINANTLY WEST OF THE MISSISSIPPI RIVER...IN THE WARM SECTOR AHEAD
OF THE COLD FRONT...LATEST HRRR MODEL SHOWS SOME ISOLATED CELLS
FORMING BY EARLY AFTERNOON AS THE MODERATE UPPER LEVEL HEIGHT FALLS ARE
OCCURRING. WITH LATEST GUIDANCE SUGGESTING ABOUT 800-1000 J/KG
SBCAPE...60 KTS OF BULK SHEAR...AND A WEAK CAP IN PLACE
.CONVECTION WILL INITIATE. THIS WILL ALLOW SOME ISOLATED CELLS TO
DEVELOP JUST AHEAD OF THE FRONT. SEMI-DISCREET SUPERCELLS AS WELL
AS SOME BOWING SEGMENTS WILL BE POSSIBLE. A FEW TORNADOES
ALONG WITH DAMAGING WINDS WILL BE THE PRIMARY THREAT.
BY LATE AFTERNOON ...THE COLD FRONT WILL CATCH UP TO THE PREFRONTAL
CONVECTION AND TRANSITION INTO A IMPRESSIVE QLCS (SQUALL LINE).
THIS IS WHEN DAMAGING WINDS WILL BECOME THE PRIMARY THREAT.
DAMAGING WINDS MAY BECOME WIDESPREAD EAST OF THE MISSISSIPPI RIVER
ALONG WITH A FEW SIGNIFICANT WIND GUSTS IN EXCESS OF 70MPH. AS THE
LINE MOVES EASTWARD...SOME EMBEDDED MESOVORTICES WITHIN THE QLCS
MAY POSE AN ISOLATED TORNADO RISK. ANY TORNADOES EMBEDDED WITHIN
THE LINE SHOULD BE SHORT TRACKED. THE SEVERE LINE SHOULD DEPART
EASTERN AREAS OF THE CWA BY LATE EVENING.
LONG TERM...FRIDAY THROUGH NEXT WEEK...
AFTER THE COLD FRONT MOVES THROUGH THIS EVENING...HIGH PRESSURE
WILL BUILD INTO THE REGION AND BRING A RETURN TO DRY WEATHER AND
CONTINUED MILD TEMPERATURES. THIS PLEASANT WEATHER SHOULD
CONTINUE FROM FRIDAY THROUGH THE FIRST HALF OF THE WEEKEND.
A COLD FRONT WILL MOVE THROUGH THE MID SOUTH ON SUNDAY BRINGING A
RETURN TO COOLER TEMPERATURES. DRY CONDITIONS SHOULD CONTINUE INTO
EARLY NEXT WEEK WITH TEMPERATURES RETURNING TO NEAR OR SLIGHTLY
BELOW AVERAGE. ANOTHER REINFORCING COLD FRONT WILL MOVE THROUGH ON
TUESDAY WITH LIGHT PRECIPITATION CHANCES AND COLDER TEMPERATURES.
AC3
&&
.AVIATION...
12Z TAF CYCLE
SURFACE LOW PRESSURE ORGANIZING ACROSS THE SOUTHERN PLAINS THIS
MORNING WILL CONTINUE TO TIGHTEN THE PRESSURE GRADIENT. AS THIS
LOW LIFTS NORTHEAST AND DEEPENS THROUGH THE AFTERNOON...A VERY
TIGHT GRADIENT WILL DEVELOP. THIS TRANSLATES INTO STRONG SOUTHERLY
WINDS AT ALL TERMINALS BEGINNING THIS MORNING AND CONTINUING INTO
THE LATE AFTERNOON AND EVENING AHEAD OF A COLD FRONTAL PASSAGE.
SUSTAINED WINDS IN EXCESS OF 25 KTS WILL BE COMMON...WITH GUSTS
BETWEEN 35-40 KTS...ESPECIALLY BY THIS AFTERNOON.
IN ADDITION...MVFR CIGS WILL CONTINUE TO ADVECT INTO THE TERMINALS
EARLY THIS MORNING...BEFORE STRONG MIXING BENEATH A STOUT CAPPING
INVERSION BASED AROUND 7 KFT AS OBSERVED FROM THE 12Z LZK
SOUNDING...HELPS TO BRING CIGS UP BY MID/LATE MORNING TO VFR
LEVELS AND BECOMING INCREASINGLY BKN.
SCATTERED SHOWERS MAY IMPACT KJBR AND KMEM FROM LATE MORNING INTO
THE EARLY AFTERNOON. THIS WILL BE PRIOR TO POTENTIAL SEVERE
THUNDERSTORMS DEVELOPING IN SCATTERED FASHION NEAR KJBR BY MID
AFTERNOON (20/20Z-20/22Z). THESE STORMS SHOULD CONSOLIDATE INTO A MORE SOLID LINE
BY LATE AFTERNOON...IMPACTING KMEM BETWEEN 20/21Z-20/23Z. THIS LINE
WILL RACE EAST AND SHOULD IMPACT KMKL BETWEEN 20/22Z-21/00Z AND KTUP
BETWEEN 21/00Z-21/02Z. DAMAGING WIND GUSTS WILL BE POSSIBLE...ESPECIALLY
EAST OF THE MISSISSIPPI RIVER. VSBYS MAY BE REDUCED TO IFR DURING
ANY STRONG CONVECTION.
WINDS WILL SWITCH NORTHWESTERLY BEHIND THE CONVECTIVE LINE AND
DIMINISH LATE TONIGHT AS SKIES EVENTUALLY CLEAR OVERNIGHT.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 74 40 62 41 / 100 50 0 0
MKL 75 37 61 36 / 90 70 0 0
JBR 72 35 59 37 / 60 10 0 0
TUP 77 40 62 37 / 60 100 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR DUNKLIN-PEMISCOT.
MS...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR ALCORN-BENTON MS-
CALHOUN-CHICKASAW-COAHOMA-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-QUITMAN-
TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-UNION-YALOBUSHA.
TN...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR BENTON TN-CARROLL-
CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-
HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-
MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
637 AM CST THU FEB 20 2014
.UPDATE...FOR 12Z AVIATION FORECAST
&&
.AVIATION...
MVFR CEILINGS HAVE MOVED NORTHWARD LAST COUPLE OF HOURS WITH IFR
AT CROSSVILLE. EVEN WITH THE WINDS TODAY NOT SURE WE CAN MIX OUT
ENOUGH TO GET BREAKS IN CLOUDS FOR VERY LONG. THINK THE MAIN
CONCERN INITIALLY TODAY WILL BE LOW LEVEL WIND SHEAR OFF SURFACE
AFFECTING LANDINGS AND TAKEOFFS. SOUTHERNLY WINDS WILL BE GUSTY
THROUGHOUT THE DAY. FRONTOGENICS GET STRONGER DURING THE AFTERNOON
IN EASTERN ARKANSAS AND THINK THIS WHERE WILL WE SEE SQUALL LINE
DEVELOP JUST AHEAD OF COLD FRONT. SQUALL LINE SHOULD BE ALONG
MISSISSIPPI RIVER AT 22Z. HRRR HAS SQUALL LINE INTO THE
CLARKSVILLE AREA AROUND 6 PM...NASHVILLE ABOUT 7 PM AND CROSSVILLE
BY 11 PM.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST TONIGHT FOR
TNZ009>011-029>034-063>066-077>080.
WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS EVENING
FOR TNZ005>008-023>028-056>062-075-093>095.
&&
$$
BOYD
01
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
557 AM CST THU FEB 20 2014
.UPDATE...
UPDATED FOR THE 12Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 449 AM CST THU FEB 20 2014/
DISCUSSION...
...A SIGNIFICANT COLD FRONT WILL BRING SEVERE WEATHER TO THE ENTIRE
MID-SOUTH THIS AFTERNOON AND INTO THIS EVENING...
.SYNOPSIS...CURRENT GOES WATER VAPOR IMAGERY SHOWS A SIGNIFICANT
LONGWAVE TROUGH DIGGING ACROSS THE CENTRAL PLAINS THIS MORNING.
THIS TROUGH WILL CONTINUE TO DEEPEN AND ACQUIRE A NEGATIVE TILT AS
IT PUSHES INTO THE MID MISSISSIPPI VALLEY THIS AFTERNOON. LATEST
SURFACE ANALYIS SHOWS AN ASSOCIATED AND IMPRESSIVE 992MB DEEPENING
LOW PRESSURE SYSTEM LOCATED JUST TO THE NORTH OF THE OKLAHOMA
PANHANDLE. THIS SURFACE CYCLONE IS EXPECTED TO TRACK NORTHEAST
THROUGH NORTHERN MISSOURI THIS AFTERNOON...AND INTO THE
GREAT LAKES REGION BY THIS EVENING. SURFACE DEWPOINTS ACROSS THE
SOUTH RANGE FROM MID TO UPPER 50S TO MID 60S AS A WARM FRONT
CONTINUES TO PUSH NORTH. THIS SYSTEM IS EXPECTED TO BECOME
OCCLUDED JUST AS IT ARRIVES INTO THE MID-SOUTH. THIS ENVIRONMENT
WILL SET THE STAGE FOR A STRONG SQUALL LINE OF THUNDERSTORMS ALONG
THE COLD FRONT TO PUSH THROUGH THIS AFTERNOON INTO TONIGHT.
IN RESPECT TO TIMING AND THREATS...
THE INITIAL CONVECTIVE MODE IS EXPECTED TO BE MIXED AND THEN
TRANSITION INTO A LINEAR MODE BY 4 PM OR SO JUST AS IT ARRIVES AT
THE MISSISSIPPI RIVER.
PREDOMINANTLY WEST OF THE MISSISSIPPI RIVER...IN THE WARM SECTOR AHEAD
OF THE COLD FRONT...LATEST HRRR MODEL SHOWS SOME ISOLATED CELLS
FORMING BY EARLY AFTERNOON AS THE MODERATE UPPER LEVEL HEIGHT FALLS ARE
OCCURRING. WITH LATEST GUIDANCE SUGGESTING ABOUT 800-1000 J/KG
SBCAPE...60 KTS OF BULK SHEAR...AND A WEAK CAP IN PLACE
..CONVECTION WILL INITIATE. THIS WILL ALLOW SOME ISOLATED CELLS TO
DEVELOP JUST AHEAD OF THE FRONT. SEMI-DISCREET SUPERCELLS AS WELL
AS SOME BOWING SEGMENTS WILL BE POSSIBLE. A FEW TORNADOES
ALONG WITH DAMAGING WINDS WILL BE THE PRIMARY THREAT.
BY LATE AFTERNOON ...THE COLD FRONT WILL CATCH UP TO THE PREFRONTAL
CONVECTION AND TRANSITION INTO A IMPRESSIVE QLCS (SQUALL LINE).
THIS IS WHEN DAMAGING WINDS WILL BECOME THE PRIMARY THREAT.
DAMAGING WINDS MAY BECOME WIDESPREAD EAST OF THE MISSISSIPPI RIVER
ALONG WITH A FEW SIGNIFICANT WIND GUSTS IN EXCESS OF 70MPH. AS THE
LINE MOVES EASTWARD...SOME EMBEDDED MESOVORTICES WITHIN THE QLCS
MAY POSE AN ISOLATED TORNADO RISK. ANY TORNADOES EMBEDDED WITHIN
THE LINE SHOULD BE SHORT TRACKED. THE SEVERE LINE SHOULD DEPART
EASTERN AREAS OF THE CWA BY LATE EVENING.
.LONG TERM...FRIDAY THROUGH NEXT WEEK...
AFTER THE COLD FRONT MOVES THROUGH THIS EVENING...HIGH PRESSURE
WILL BUILD INTO THE REGION AND BRING A RETURN TO DRY WEATHER AND
CONTINUED MILD TEMPERATURES. THIS PLEASANT WEATHER SHOULD
CONTINUE FROM FRIDAY THROUGH THE FIRST HALF OF THE WEEKEND.
A COLD FRONT WILL MOVE THROUGH THE MID SOUTH ON SUNDAY BRINGING A
RETURN TO COOLER TEMPERATURES. DRY CONDITIONS SHOULD CONTINUE INTO
EARLY NEXT WEEK WITH TEMPERATURES RETURNING TO NEAR OR SLIGHTLY
BELOW AVERAGE. ANOTHER REINFORCING COLD FRONT WILL MOVE THROUGH ON
TUESDAY WITH LIGHT PRECIPITATION CHANCES AND COLDER TEMPERATURES.
AC3
&&
.AVIATION...
12Z TAF CYCLE
SURFACE LOW PRESSURE ORGANIZING ACROSS THE SOUTHERN PLAINS THIS
MORNING WILL CONTINUE TO TIGHTEN THE PRESSURE GRADIENT. AS THIS
LOW LIFTS NORTHEAST AND DEEPENS THROUGH THE AFTERNOON...A VERY
TIGHT GRADIENT WILL DEVELOP. THIS TRANSLATES INTO STRONG SOUTHERLY
WINDS AT ALL TERMINALS BEGINNING THIS MORNING AND CONTINUING INTO
THE LATE AFTERNOON AND EVENING AHEAD OF A COLD FRONTAL PASSAGE.
SUSTAINED WINDS IN EXCESS OF 25 KTS WILL BE COMMON...WITH GUSTS
BETWEEN 35-40 KTS...ESPECIALLY BY THIS AFTERNOON.
IN ADDITION...MVFR CIGS WILL CONTINUE TO ADVECT INTO THE TERMINALS
EARLY THIS MORNING...BEFORE STRONG MIXING BENEATH A STOUT CAPPING
INVERSION BASED AROUND 7 KFT AS OBSERVED FROM THE 12Z LZK
SOUNDING...HELPS TO BRING CIGS UP BY MID/LATE MORNING TO VFR
LEVELS AND BECOMING INCREASINGLY BKN.
SCATTERED SHOWERS MAY IMPACT KJBR AND KMEM FROM LATE MORNING INTO
THE EARLY AFTERNOON. THIS WILL BE PRIOR TO POTENTIAL SEVERE
THUNDERSTORMS DEVELOPING IN SCATTERED FASHION NEAR KJBR BY MID
AFTERNOON (20/20Z-20/22Z). THESE STORMS SHOULD CONSOLIDATE INTO A MORE SOLID LINE
BY LATE AFTERNOON...IMPACTING KMEM BETWEEN 20/21Z-20/23Z. THIS LINE
WILL RACE EAST AND SHOULD IMPACT KMKL BETWEEN 20/22Z-21/00Z AND KTUP
BETWEEN 21/00Z-21/02Z. DAMAGING WIND GUSTS WILL BE POSSIBLE...ESPECIALLY
EAST OF THE MISSISSIPPI RIVER. VSBYS MAY BE REDUCED TO IFR DURING
ANY STRONG CONVECTION.
WINDS WILL SWITCH NORTHWESTERLY BEHIND THE CONVECTIVE LINE AND
DIMINISH LATE TONIGHT AS SKIES EVENTUALLY CLEAR OVERNIGHT.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 74 40 62 41 / 100 50 0 0
MKL 75 37 61 36 / 90 70 0 0
JBR 72 35 59 37 / 60 10 0 0
TUP 77 40 62 37 / 60 100 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS EVENING
FOR CLAY-CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS EVENING
FOR DUNKLIN-PEMISCOT.
MS...WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS EVENING
FOR ALCORN-BENTON MS-CALHOUN-CHICKASAW-COAHOMA-DESOTO-
ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL-MONROE-PANOLA-PONTOTOC-
PRENTISS-QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-
UNION-YALOBUSHA.
TN...WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS EVENING
FOR BENTON TN-CARROLL-CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-
GIBSON-HARDEMAN-HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-
LAUDERDALE-MADISON-MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
449 AM CST THU FEB 20 2014
.DISCUSSION...
A SIGNIFICANT COLD FRONT WILL BRING SEVERE WEATHER TO THE ENTIRE
MID-SOUTH THIS AFTERNOON AND INTO THIS EVENING.
SYNOPSIS...CURRENT GOES WATER VAPOR IMAGERY SHOWS A SIGNIFICANT
LONGWAVE TROUGH DIGGING ACROSS THE CENTRAL PLAINS THIS MORNING.
THIS TROUGH WILL CONTINUE TO DEEPEN AND ACQUIRE A NEGATIVE TILT AS
IT PUSHES INTO THE MID MISSISSIPPI VALLEY THIS AFTERNOON. LATEST
SURFACE ANALYIS SHOWS AN ASSOCIATED AND IMPRESSIVE 992MB DEEPENING
LOW PRESSURE SYSTEM LOCATED JUST TO THE NORTH OF THE OKLAHOMA
PANHANDLE. THIS SURFACE CYCLONE IS EXPECTED TO TRACK NORTHEAST
THROUGH NORTHERN MISSOURI THIS AFTERNOON...AND INTO THE
GREAT LAKES REGION BY THIS EVENING. SURFACE DEWPOINTS ACROSS THE
SOUTH RANGE FROM MID TO UPPER 50S TO MID 60S AS A WARM FRONT
CONTINUES TO PUSH NORTH. THIS SYSTEM IS EXPECTED TO BECOME
OCCLUDED JUST AS IT ARRIVES INTO THE MID-SOUTH. THIS ENVIRONMENT
WILL SET THE STAGE FOR A STRONG SQUALL LINE OF THUNDERSTORMS ALONG
THE COLD FRONT TO PUSH THROUGH THIS AFTERNOON INTO TONIGHT.
IN RESPECT TO TIMING AND THREATS...
THE INITIAL CONVECTIVE MODE IS EXPECTED TO BE MIXED AND THEN
TRANSITION INTO A LINEAR MODE BY 4 PM OR SO JUST AS IT ARRIVES AT
THE MISSISSIPPI RIVER.
PREDOMINANTLY WEST OF THE MISSISSIPPI RIVER...IN THE WARM SECTOR AHEAD
OF THE COLD FRONT...LATEST HRRR MODEL SHOWS SOME ISOLATED CELLS
FORMING BY EARLY AFTERNOON AS THE MODERATE UPPER LEVEL HEIGHT FALLS ARE
OCCURRING. WITH LATEST GUIDANCE SUGGESTING ABOUT 800-1000 J/KG
SBCAPE...60 KTS OF BULK SHEAR...AND A WEAK CAP IN PLACE
...CONVECTION WILL INITIATE. THIS WILL ALLOW SOME ISOLATED CELLS TO
DEVELOP JUST AHEAD OF THE FRONT. SEMI-DISCREET SUPERCELLS AS WELL
AS SOME BOWING SEGMENTS WILL BE POSSIBLE. A FEW TORNADOES
ALONG WITH DAMAGING WINDS WILL BE THE PRIMARY THREAT.
BY LATE AFTERNOON ...THE COLD FRONT WILL CATCH UP TO THE PREFRONTAL
CONVECTION AND TRANSITION INTO A IMPRESSIVE QLCS (SQUALL LINE).
THIS IS WHEN DAMAGING WINDS WILL BECOME THE PRIMARY THREAT.
DAMAGING WINDS MAY BECOME WIDESPREAD EAST OF THE MISSISSIPPI RIVER
ALONG WITH A FEW SIGNIFICANT WIND GUSTS IN EXCESS OF 70MPH. AS THE
LINE MOVES EASTWARD...SOME EMBEDDED MESOVORTICES WITHIN THE QLCS
MAY POSE AN ISOLATED TORNADO RISK. ANY TORNADOES EMBEDDED WITHIN
THE LINE SHOULD BE SHORT TRACKED. THE SEVERE LINE SHOULD DEPART
EASTERN AREAS OF THE CWA BY LATE EVENING.
...FRIDAY THROUGH NEXT WEEK...
AFTER THE COLD FRONT MOVES THROUGH THIS EVENING...HIGH PRESSURE
WILL BUILD INTO THE REGION AND BRING A RETURN TO DRY WEATHER AND
CONTINUED MILD TEMPERATURES. THIS PLEASANT WEATHER SHOULD
CONTINUE FROM FRIDAY THROUGH THE FIRST HALF OF THE WEEKEND.
A COLD FRONT WILL MOVE THROUGH THE MID SOUTH ON SUNDAY BRINGING A
RETURN TO COOLER TEMPERATURES. DRY CONDITIONS SHOULD CONTINUE INTO
EARLY NEXT WEEK WITH TEMPERATURES RETURNING TO NEAR OR SLIGHTLY
BELOW AVERAGE. ANOTHER REINFORCING COLD FRONT WILL MOVE THROUGH ON
TUESDAY WITH LIGHT PRECIPITATION CHANCES AND COLDER TEMPERATURES.
AC3
&&
.AVIATION...
06Z TAF SET
A WARM FRONT HAS LIFTED NORTHWARD ACROSS THE AREA. SE WINDS ARE
OCCURRING EVERYWHERE EXCEPT KJBR BUT EXPECT THEM TO SHIFT SHORTLY.
ALL TAF SITES ARE VFR FOR NOW. STRATUS WILL INVADE THE AREA FROM
THE SOUTH BETWEEN 8-12Z. CIGS WILL DROP TO MVFR DURING THAT TIME.
THE MVFR CIGS WILL CONTINUE UNTIL A COLD FRONT PUSHES THROUGH.
KJBR WILL BE IMPACTED FIRST BETWEEN 16-20Z. SCATTERED TSRAS WILL
DEVELOP AHEAD OF THE FRONT AND EVENTUALLY WILL FORM A SQUALL LINE
ROUGHLY AROUND THE MISSISSIPPI RIVER. TSRAS WILL IMPACT KMEM
BETWEEN 19-22Z...KMKL BETWEEN 20-24Z AND KTUP BETWEEN 23-03Z. STRONG
S WINDS WILL OCCUR AHEAD OF THE FRONT. EXPECT SPEEDS TO INCREASE
TO 15-20 KTS SUSTAINED WITH GUSTS UP TO 30 KTS AFTER 14-16Z. WINDS
WILL TURN AROUND TO THE NW BEHIND THE FRONT WITH SPEEDS
EXPECTED TO DIMINISH AS WELL AT THAT TIME.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 74 40 62 41 / 100 50 0 0
MKL 75 37 61 36 / 90 70 0 0
JBR 72 35 59 37 / 60 10 0 0
TUP 77 40 62 37 / 60 100 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS EVENING
FOR CLAY-CRAIGHEAD-CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-
MISSISSIPPI-PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS EVENING
FOR DUNKLIN-PEMISCOT.
MS...WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS EVENING
FOR ALCORN-BENTON MS-CALHOUN-CHICKASAW-COAHOMA-DESOTO-
ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL-MONROE-PANOLA-PONTOTOC-
PRENTISS-QUITMAN-TALLAHATCHIE-TATE-TIPPAH-TISHOMINGO-TUNICA-
UNION-YALOBUSHA.
TN...WIND ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS EVENING
FOR BENTON TN-CARROLL-CHESTER-CROCKETT-DECATUR-DYER-FAYETTE-
GIBSON-HARDEMAN-HARDIN-HAYWOOD-HENDERSON-HENRY-LAKE-
LAUDERDALE-MADISON-MCNAIRY-OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1008 PM PST Wed Feb 19 2014
.SYNOPSIS...
A fast moving disturbance will bring a swath of snow to northeast
Washington and north Idaho early Thursday morning followed by more
gusty winds Thursday afternoon. Snow showers are expected to
linger over the mountains on Friday, but there should be less
wind. The weekend is expected to be colder than average with
chance for snow, mainly over the mountains.
&&
.DISCUSSION...
Evening update: main adjustment was to slow the timing of the
winter weather advisories and overall precipitation onset with the
incoming system. The latest HRRR and other short-range guidance
that came in shows the main threat begins overnight (somewhere in
the 08-11Z time frame.) It looks like a quick mover and much of it
should be slipping into the northeast WA and Panhandle mountains
by mid-morning. However a messy commute time in the larger
populated Spokane/C`dA area and Palouse remains a good threat. /J. Cote`
&&
.AVIATION...
06Z TAFs: VFR conditions at all TAF sites expected this evening
through 08-10Z. After ad through 14z-16Z a warm front and swiftly
trailing occluded front will move through the region bringing a 3
to 5 hour period of likely IFR visibilities and ceilings in light
snow to the KGEG,KSFF,KCOE and KPUW TAF sites. A shorter period of
MVFR or possible IFR conditions in -SN is possible at KEAT between
08Z and 12Z. KMWH is likely to be skipped by precipitation and
KLWS may receive some MVFR ceilings and vis as the front passes.
Otherwise conditions will improve quickly after the occlusion
passes with a mainly orographic lingering shower regime which may
impact the KGEG area TAF sites with brief MVFR conditions during
the unstable afternoon period. Breezy to windy conditions in the
afternoon expected, before gradually dissipating after 00-03Z. /J.
Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 28 41 26 35 21 34 / 90 100 30 10 10 10
Coeur d`Alene 28 39 25 34 18 32 / 70 100 50 20 10 10
Pullman 29 41 27 36 23 34 / 70 80 30 20 10 0
Lewiston 32 48 32 45 28 41 / 50 50 20 30 10 0
Colville 26 41 23 37 17 35 / 80 90 60 20 10 10
Sandpoint 23 37 24 34 17 32 / 50 100 80 20 20 10
Kellogg 25 35 24 32 18 30 / 60 100 80 40 30 10
Moses Lake 32 48 29 44 25 40 / 40 10 0 0 10 10
Wenatchee 29 44 28 42 23 39 / 60 20 0 0 10 10
Omak 28 41 23 38 20 35 / 80 20 10 0 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory from 2 AM to 4 PM PST Thursday for
Central Panhandle Mountains.
Winter Weather Advisory from 1 AM to 8 AM PST Thursday for Coeur
d`Alene Area-Idaho Palouse.
Winter Weather Advisory from 1 AM to 10 AM PST Thursday for
Northern Panhandle.
WA...Winter Weather Advisory from 1 AM to 8 AM PST Thursday for
Spokane Area-Washington Palouse.
Winter Weather Advisory from 1 AM to 10 AM PST Thursday for
Northeast Mountains.
Winter Weather Advisory until 10 AM PST Thursday for East Slopes
Northern Cascades.
Winter Weather Advisory until 4 PM PST Thursday for Northeast
Blue Mountains.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
411 AM CST THU FEB 20 2014
.UPDATE...
ISSUED AT 410 AM CST THU FEB 20 2014
NOTE HEADLINE CHANGES BELOW. LATEST WSW STATEMENT WILL BE OUT
SHORTLY.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 358 AM CST THU FEB 20 2014
POWERFUL/DANGEROUS WINTER STORM IMPACTS THE AREA TODAY INTO FRIDAY.
CURRENTLY SEEING SOME LIGHT/MOSTLY LIQUID FORM PRECIPITATION WORKING
NORTHEAST WARD INTO PORTIONS OF NORTHEAST IA/SOUTHWEST WI EARLY THIS
MORNING. THIS IS IN RESPONSE TO A MID-LEVEL TROUGH AHEAD OF THE
POTENT TROUGH AND STRONG SURFACE CYCLOGENESIS TAKING PLACE OVER THE
SOUTHERN PLAINS. LOOK FOR THIS FIRST AND ASSOCIATED RAIN/SLEET/SNOW
TO EXIT EAST THIS MORNING. THERE MAY BE A A LULL IN THE ACTION BY
MID-MORNING..TRANSITIONING TO MORE OF A DRIZZLE. EXPECTING SOME
LIGHT ICING ON ROADWAYS/SIDEWALKS WHERE TEMPERATURES WILL BE AT OR
EVEN BELOW FREEZING.
THEN...LOOK FOR THE MAIN/POWERFUL STORM SYSTEM TO LIFT FROM THE
SOUTHERN PLAINS TO JUST EAST OF GRANT COUNTY IN SOUTHWEST WI BY
00Z/6PM. AS THE LOW APPROACHES...MODEL SHOW MAXIMUM TEMPERATURES
ALOFT INCREASING INTO THE +3 TO +8C RANGE ACROSS A SMALL PART OF
NORTHEAST IA INTO SOUTHWEST AND CENTRAL WI. AS A RESULT...MUCH OF
THE PRECIPITATION FALLING ACROSS THIS AREA TODAY WILL BE IN THE FORM
OF RAIN. MEANWHILE...FARTHER WEST ACROSS NORTHEAST IA/SOUTHEAST
MN/NORTHWEST WI...TEMPERATURE PROFILES SUPPORT SNOW. THIS WILL BE
MAINLY NORTHWEST OF A LINE FROM NEW HAMPTON IA/PRESTON MN/WINONA
LINE. STRONG FRONTOGENESIS/NEGATIVE EPV SUPPORTS THE THREAT FOR
THUNDERSNOW AND INTENSE SNOW RATES EASILY 1 IN/HR THIS AFTERNOON. IN
ADDITION...STRONG NORTHWEST WINDS WILL BE KICKING IN BY LATER THIS
AFTERNOON ON THE BACKSIDE OF THE DEEP 982MB LOW. THINKING THIS AREA
SHOULD SEE SNOWFALL IN THE 5-8 INCH RANGE IN THE NOON TO 6 PM
TIMEFRAME. IN ADDITION...STRONG NORTHWEST WINDS WILL BE KICKING IN
LATER IN THE AFTERNOON FOR WIDESPREAD BLOWING AND DRIFTING AND
OCCASIONAL WHITEOUT CONDITIONS.
LOOK FOR THE HEAVY SNOW TO CONTINUE THROUGH THE EVENING OVER
NORTHEAST IA/SOUTHEAST MN INTO NORTHERN WI TONIGHT AS THE LOW PULLS
TOWARD LAKE SUPERIOR BY 6 AM. PRECIPITATION WILL TRANSITION QUICKLY
TO ALL SNOW ACROSS THE REST OF THE AREA AS COLDER AIR IS DRAWN IN BY
THE SYSTEM. VERY STRONG/GUSTY NORTHWEST WINDS WILL BE IN PLACE
ACROSS THE ENTIRE AREA WITH GUSTS APPROACHING 50 MPH ACROSS THE MORE
OPEN AREAS OF NORTHEAST IA/SOUTHEAST MN...CONTINUING THE BLOWING AND
DRIFTING. LOOK FOR THE SNOW TO SLOWLY TAPER LATER TONIGHT/AFTER
MIDNIGHT THROUGH FRIDAY MORNING FROM SOUTH TO NORTH AS THE LOW PULLS
INTO THE U.P...BUT STRONG GUSTY WINDS WILL CONTINUE TO CAUSE BLOWING
AND DRIFTING PROBLEMS.
BY THE TIME ALL IS SAID AND DONE AROUND NOON FRIDAY...6-12 INCH SNOW
ACCUMULATIONS CAN BE EXPECTED ACROSS PORTIONS OF NORTHEAST
IA/SOUTHEAST MN INTO NORTH CENTRAL WI.
DUE TO THE COMPLEXITY OF THE THERMAL PROFILE OF THIS POWERFUL STORM
AND AFFECT IT HAS ON SNOWFALL AMOUNTS AND PRECIPITATION
TYPES...HEADLINES WERE ADJUSTED/EXTENDED OVERNIGHT.
FOR FULL DETAILS INCLUDING WINTER WEATHER HEADLINES/GRAPHICAL
DISPLAY OF SNOW AMOUNTS AND OTHER HAZARDS TIED TO THE STORM...SEE
OUR NEWS STORY ON OUR INTERNET PAGE AT WWW.WEATHER.GOV/LACROSSE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 AM CST THU FEB 20 2014
WITH THE DEPARTING STORM SYSTEM FRIDAY...LOOK FOR COLDER NORTHWEST
FLOW ALOFT TO KICK IN INTO NEXT WEEK. UNSEASONABLY COLD TEMPERATURES
WILL RESULT WITH HIGHS SATURDAY STARTING OFF IN THE TEENS AND LOWER
20S...THEN DROPPING INTO THE UPPER SINGLE DIGITS AND TEENS ABOVE ZERO
BY WEDNESDAY. OVERNIGHT LOWS ARE EXPECTED TO DIP INTO THE SINGLE
DIGITS ABOVE AND BELOW ZERO...POSSIBLY TEEN/NEAR 20 BELOW BY
WEDNESDAY NIGHT. ALSO...APPEARS THERE WILL BE A SHOT AT SOME LIGHT
SNOW MONDAY/MONDAY NIGHT TIME FRAME AS A WEAK MID-LEVEL TROUGH
ROTATES THROUGH THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1122 PM CST WED FEB 19 2014
NO SIGNIFICANT FORECAST CHANGES EXPECTED BASED ON THE LATEST MODEL
INFORMATION. REGIONAL RADARS SHOWING THE FIRST WAVE OF
PRECIPITATION OCCURRING OVER SOUTHERN IOWA MOVING NORTHEAST. THE
20.00Z NAM AND 20.03Z HRRR SHOW THE BULK OF THIS PRECIPITATION
MOVING PAST THE TAF SITES TO THE SOUTHEAST. STILL EXPECTING SOME
LIGHT PRECIPITATION TO HIT THE TAF SITES AS THIS COMES IN AND THE
CONCERN REMAINS WHETHER THERE WILL BE ICE AVAILABLE IN THE CLOUDS
AND IF THERE IS...WILL THE WARM LAYER ABOVE THE SURFACE BE ENOUGH
FOR COMPLETE OR PARTIAL MELTING. HAVE CONTINUED THE TREND OF
SHOWING LIGHT SNOW WITH A PERIOD OF FREEZING RAIN AND SLEET
POSSIBLE AT KLSE AND INTRODUCED THE FREEZING RAIN THREAT AT KRST
AS WELL. BY MID MORNING...LOW LEVEL TEMPERATURES STILL EXPECTED TO
BE WARM ENOUGH FOR A RAIN/SNOW MIX AT KLSE WHILE PRIMARILY SNOW IS
EXPECTED AT KRST. THIS INITIAL PRECIPITATION SHOULD PRODUCE
PRIMARILY MVFR CONDITIONS. CONDITIONS THEN DETERIORATE RAPIDLY
DURING THE AFTERNOON AS THE STRONG FORCING MOVES IN WITH MODERATE
TO HEAVY SNOW AND IFR CONDITIONS INTO THE EVENING HOURS. ONCE THE
SURFACE LOW MOVES PAST...THE FALLING SNOW WILL START TO DECREASE
IN INTENSITY BUT THE WINDS WILL BECOME STRONG OUT OF THE WEST WITH
GUSTS OF 30 TO 40 KNOTS WHICH WILL PRODUCE BLOWING SNOW AT BOTH
AIRPORTS AND KEEP KRST IN IFR CONDITIONS.
.HYDROLOGY...(FOR TODAY INTO EARLY THIS EVENING)
ISSUED AT 358 AM CST THU FEB 20 2014
WITH WARMER AIR WRAPPING INTO THIS INTENSE LOW...MORE RAINFALL WILL
BE SEEN ACROSS SOUTHWEST INTO CENTRAL WI. WITH FROZEN GROUND AND
SEWERS PLUGGED WITH ICE/SNOW...LOOK FOR PONDING OF WATER AND SOME
RUNOFF INTO STREAMS FOR LOCAILZED RISES WHERE STREAM ARE RUNNING
UNFROZEN.
&&
.HYDROLOGY...(FOR TODAY INTO EARLY THIS EVENING)
ISSUED AT 358 AM CST THU FEB 20 2014
WITH WARMER AIR WRAPPING INTO THIS INTENSE LOW...MORE RAINFALL WILL
BE SEEN ACROSS SOUTHWEST INTO CENTRAL WI. WITH FROZEN GROUND AND
SEWERS PLUGGED WITH ICE/SNOW...LOOK FOR PONDING OF WATER AND SOME
RUNOFF INTO STREAMS FOR LOCAILZED RISES WHERE STREAM ARE RUNNING
UNFROZEN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL NOON CST FRIDAY FOR WIZ041>044-
053>055-061.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO NOON CST FRIDAY
FOR WIZ017-029-032>034.
MN...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR
MNZ086>088-094-095.
BLIZZARD WARNING FROM 9 AM THIS MORNING TO NOON CST FRIDAY FOR
MNZ079-086-087-094-095.
WINTER WEATHER ADVISORY UNTIL NOON CST FRIDAY FOR MNZ096.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO NOON CST FRIDAY
FOR MNZ088.
IA...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR
IAZ008>010-018-019-029.
BLIZZARD WARNING FROM 9 AM THIS MORNING TO NOON CST FRIDAY FOR
IAZ008>010-018-019-029.
WINTER WEATHER ADVISORY UNTIL NOON CST FRIDAY FOR IAZ011-030.
&&
$$
UPDATE...ZT
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
358 AM CST THU FEB 20 2014
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 358 AM CST THU FEB 20 2014
POWERFUL/DANGEROUS WINTER STORM IMPACTS THE AREA TODAY INTO FRIDAY.
CURRENTLY SEEING SOME LIGHT/MOSTLY LIQUID FORM PRECIPITATION WORKING
NORTHEAST WARD INTO PORTIONS OF NORTHEAST IA/SOUTHWEST WI EARLY THIS
MORNING. THIS IS IN RESPONSE TO A MID-LEVEL TROUGH AHEAD OF THE
POTENT TROUGH AND STRONG SURFACE CYCLOGENESIS TAKING PLACE OVER THE
SOUTHERN PLAINS. LOOK FOR THIS FIRST AND ASSOCIATED RAIN/SLEET/SNOW
TO EXIT EAST THIS MORNING. THERE MAY BE A A LULL IN THE ACTION BY
MID-MORNING..TRANSITIONING TO MORE OF A DRIZZLE. EXPECTING SOME
LIGHT ICING ON ROADWAYS/SIDEWALKS WHERE TEMPERATURES WILL BE AT OR
EVEN BELOW FREEZING.
THEN...LOOK FOR THE MAIN/POWERFUL STORM SYSTEM TO LIFT FROM THE
SOUTHERN PLAINS TO JUST EAST OF GRANT COUNTY IN SOUTHWEST WI BY
00Z/6PM. AS THE LOW APPROACHES...MODEL SHOW MAXIMUM TEMPERATURES
ALOFT INCREASING INTO THE +3 TO +8C RANGE ACROSS A SMALL PART OF
NORTHEAST IA INTO SOUTHWEST AND CENTRAL WI. AS A RESULT...MUCH OF
THE PRECIPITATION FALLING ACROSS THIS AREA TODAY WILL BE IN THE FORM
OF RAIN. MEANWHILE...FARTHER WEST ACROSS NORTHEAST IA/SOUTHEAST
MN/NORTHWEST WI...TEMPERATURE PROFILES SUPPORT SNOW. THIS WILL BE
MAINLY NORTHWEST OF A LINE FROM NEW HAMPTON IA/PRESTON MN/WINONA
LINE. STRONG FRONTOGENESIS/NEGATIVE EPV SUPPORTS THE THREAT FOR
THUNDERSNOW AND INTENSE SNOW RATES EASILY 1 IN/HR THIS AFTERNOON. IN
ADDITION...STRONG NORTHWEST WINDS WILL BE KICKING IN BY LATER THIS
AFTERNOON ON THE BACKSIDE OF THE DEEP 982MB LOW. THINKING THIS AREA
SHOULD SEE SNOWFALL IN THE 5-8 INCH RANGE IN THE NOON TO 6 PM
TIMEFRAME. IN ADDITION...STRONG NORTHWEST WINDS WILL BE KICKING IN
LATER IN THE AFTERNOON FOR WIDESPREAD BLOWING AND DRIFTING AND
OCCASIONAL WHITEOUT CONDITIONS.
LOOK FOR THE HEAVY SNOW TO CONTINUE THROUGH THE EVENING OVER
NORTHEAST IA/SOUTHEAST MN INTO NORTHERN WI TONIGHT AS THE LOW PULLS
TOWARD LAKE SUPERIOR BY 6 AM. PRECIPITATION WILL TRANSITION QUICKLY
TO ALL SNOW ACROSS THE REST OF THE AREA AS COLDER AIR IS DRAWN IN BY
THE SYSTEM. VERY STRONG/GUSTY NORTHWEST WINDS WILL BE IN PLACE
ACROSS THE ENTIRE AREA WITH GUSTS APPROACHING 50 MPH ACROSS THE MORE
OPEN AREAS OF NORTHEAST IA/SOUTHEAST MN...CONTINUING THE BLOWING AND
DRIFTING. LOOK FOR THE SNOW TO SLOWLY TAPER LATER TONIGHT/AFTER
MIDNIGHT THROUGH FRIDAY MORNING FROM SOUTH TO NORTH AS THE LOW PULLS
INTO THE U.P...BUT STRONG GUSTY WINDS WILL CONTINUE TO CAUSE BLOWING
AND DRIFTING PROBLEMS.
BY THE TIME ALL IS SAID AND DONE AROUND NOON FRIDAY...6-12 INCH SNOW
ACCUMULATIONS CAN BE EXPECTED ACROSS PORTIONS OF NORTHEAST
IA/SOUTHEAST MN INTO NORTH CENTRAL WI.
DUE TO THE COMPLEXITY OF THE THERMAL PROFILE OF THIS POWERFUL STORM
AND AFFECT IT HAS ON SNOWFALL AMOUNTS AND PRECIPITATION
TYPES...HEADLINES WERE ADJUSTED/EXTENDED OVERNIGHT.
FOR FULL DETAILS INCLUDING WINTER WEATHER HEADLINES/GRAPHICAL
DISPLAY OF SNOW AMOUNTS AND OTHER HAZARDS TIED TO THE STORM...SEE
OUR NEWS STORY ON OUR INTERNET PAGE AT WWW.WEATHER.GOV/LACROSSE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 400 AM CST THU FEB 20 2014
WITH THE DEPARTING STORM SYSTEM FRIDAY...LOOK FOR COLDER NORTHWEST
FLOW ALOFT TO KICK IN INTO NEXT WEEK. UNSEASONABLY COLD TEMPERATURES
WILL RESULT WITH HIGHS SATURDAY STARTING OFF IN THE TEENS AND LOWER
20S...THEN DROPPING INTO THE UPPER SINGLE DIGITS AND TEENS ABOVE ZERO
BY WEDNESDAY. OVERNIGHT LOWS ARE EXPECTED TO DIP INTO THE SINGLE
DIGITS ABOVE AND BELOW ZERO...POSSIBLY TEEN/NEAR 20 BELOW BY
WEDNESDAY NIGHT. ALSO...APPEARS THERE WILL BE A SHOT AT SOME LIGHT
SNOW MONDAY/MONDAY NIGHT TIME FRAME AS A WEAK MID-LEVEL TROUGH
ROTATES THROUGH THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1122 PM CST WED FEB 19 2014
NO SIGNIFICANT FORECAST CHANGES EXPECTED BASED ON THE LATEST MODEL
INFORMATION. REGIONAL RADARS SHOWING THE FIRST WAVE OF
PRECIPITATION OCCURRING OVER SOUTHERN IOWA MOVING NORTHEAST. THE
20.00Z NAM AND 20.03Z HRRR SHOW THE BULK OF THIS PRECIPITATION
MOVING PAST THE TAF SITES TO THE SOUTHEAST. STILL EXPECTING SOME
LIGHT PRECIPITATION TO HIT THE TAF SITES AS THIS COMES IN AND THE
CONCERN REMAINS WHETHER THERE WILL BE ICE AVAILABLE IN THE CLOUDS
AND IF THERE IS...WILL THE WARM LAYER ABOVE THE SURFACE BE ENOUGH
FOR COMPLETE OR PARTIAL MELTING. HAVE CONTINUED THE TREND OF
SHOWING LIGHT SNOW WITH A PERIOD OF FREEZING RAIN AND SLEET
POSSIBLE AT KLSE AND INTRODUCED THE FREEZING RAIN THREAT AT KRST
AS WELL. BY MID MORNING...LOW LEVEL TEMPERATURES STILL EXPECTED TO
BE WARM ENOUGH FOR A RAIN/SNOW MIX AT KLSE WHILE PRIMARILY SNOW IS
EXPECTED AT KRST. THIS INITIAL PRECIPITATION SHOULD PRODUCE
PRIMARILY MVFR CONDITIONS. CONDITIONS THEN DETERIORATE RAPIDLY
DURING THE AFTERNOON AS THE STRONG FORCING MOVES IN WITH MODERATE
TO HEAVY SNOW AND IFR CONDITIONS INTO THE EVENING HOURS. ONCE THE
SURFACE LOW MOVES PAST...THE FALLING SNOW WILL START TO DECREASE
IN INTENSITY BUT THE WINDS WILL BECOME STRONG OUT OF THE WEST WITH
GUSTS OF 30 TO 40 KNOTS WHICH WILL PRODUCE BLOWING SNOW AT BOTH
AIRPORTS AND KEEP KRST IN IFR CONDITIONS.
.HYDROLOGY...(FOR TODAY INTO EARLY THIS EVENING)
ISSUED AT 358 AM CST THU FEB 20 2014
WITH WARMER AIR WRAPPING INTO THIS INTENSE LOW...MORE RAINFALL WILL
BE SEEN ACROSS SOUTHWEST INTO CENTRAL WI. WITH FROZEN GROUND AND
SEWERS PLUGGED WITH ICE/SNOW...LOOK FOR PONDING OF WATER AND SOME
RUNOFF INTO STREAMS FOR LOCAILZED RISES WHERE STREAM ARE RUNNING
UNFROZEN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL NOON CST FRIDAY FOR WIZ041>044-
053>055-061.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO NOON CST FRIDAY
FOR WIZ017-029-032>034.
MN...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR
MNZ086>088-094-095.
BLIZZARD WARNING FROM 9 AM THIS MORNING TO NOON CST FRIDAY FOR
MNZ079-086-087-094-095.
WINTER WEATHER ADVISORY UNTIL NOON CST FRIDAY FOR MNZ096.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO NOON CST FRIDAY
FOR MNZ088.
IA...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR
IAZ008>010-018-019-029.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1122 PM CST WED FEB 19 2014
.UPDATE...
ISSUED AT 741 PM CST WED FEB 19 2014
DID A REWORK OF THE WEATHER TYPES FOR TONIGHT INTO THURSDAY
MORNING. LOOKING AT THE FORECAST SOUNDINGS FROM BOTH THE 19.18Z
NAM AND GFS...THERE IS A POTENTIAL FOR A REAL MIXED BAG OF
PRECIPITATION TYPES. THERE MAY OR MAY NOT BE ICE IN THE CLOUDS FOR
SOME PARTS OF THE AREA AND TEMPERATURES ALOFT WILL BE WARMING THAT
COULD MELT OR PARTIALLY MELT THE FALLING SNOW IF THERE IS ICE.
PREVIOUS THINKING WAS THIS MIX COULD EXTEND NORTH TO ABOUT THE I90
CORRIDOR AND ESSENTIALLY MADE OUR WEATHER TYPES AGREE WITH WHAT
WAS BEING TALKED ABOUT IN OUR TEXT PRODUCTS. BEST POTENTIAL FOR
ICING WILL BE ACROSS THE FAR SOUTHERN SECTIONS OF THE AREA WHERE
UP TO A TENTH OF ICE IS POSSIBLE FROM FAYETTE ACROSS CLAYTON INTO
GRANT COUNTIES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 328 PM CST WED FEB 19 2014
DANGEROUS WINTER STORM TO IMPACT THE AREA THURSDAY AFTERNOON INTO
THURSDAY NIGHT.
STRONG LOW PRESSURE WILL DEVELOP OVER THE CENTRAL PLAINS TONIGHT AND
IS EXPECTED TO START TRACKING NORTHEAST TOWARD THE UPPER
MISSISSIPPI RIVER VALLEY. WARM AIR ADVECTION OVERSPREADS THE
REGION TONIGHT AHEAD OF THE DEVELOPING SYSTEM AND WILL LEAD TO A
WINTRY MIX OF FREEZING RAIN...SLEET AND SNOW. THE BULK OF THE
PRECIPITATION TONIGHT WILL OCCUR ALONG AND SOUTH OF THE INTERSTATE
90 CORRIDOR. LIGHT ICE ACCUMULATIONS OF AROUND 1/10 OF AN INCH ARE
POSSIBLE MAINLY OVER PORTIONS OF NORTHEAST IOWA INTO FAR
SOUTHWEST WISCONSIN. THIS LIGHT ICING WILL LEAD TO A SLICK
THURSDAY MORNING COMMUTE.
THE MAIN SYSTEM LIFTS INTO THE AREA THURSDAY AFTERNOON WITH
CONDITIONS RAPIDLY DETERIORATING DURING THE EARLY AFTERNOON HOURS.
LOOK FOR HEAVY SNOW TO OVERSPREAD THE REGION WITH SNOWFALL RATES
OF 1 TO 2 INCHES PER HOURS LIKELY. TRAVEL CONDITIONS WILL BECOME
DANGEROUS BY LATE THURSDAY AFTERNOON. AS THE CYCLONE LIFTS INTO
SOUTHERN WISCONSIN DURING THE LATE AFTERNOON AND EARLY EVENING
NORTHWEST WINDS WILL INCREASE TO 25 TO 35 MPH ON THE BACK SIDE OF
THE LOW...LEADING TO BLIZZARD CONDITIONS ACROSS OPEN AREAS. THERE
REMAINS SOME UNCERTAINTY ON SNOW ACCUMULATIONS OVER PORTIONS OF
CENTRAL WISCONSIN WHERE WARMER AIR WILL KEEP MORE OF A
RAIN/SLEET/SNOW MIX GOING INTO THE EARLY EVENING HOURS. DECIDED TO
INCLUDE GRANT COUNTY IN THE WINTER STORM WARNING WHERE AROUND 3.5
INCHES OF SNOW AND THE STRONG NORTHWEST WINDS WILL LEAD TO NEAR
BLIZZARD CONDITIONS AT TIMES. THE MORE SHELTERED LOCATIONS OVER
CENTRAL WISCONSIN ARE EXPECTED TO SEE SNOW AMOUNTS OF 1 TO 3
INCHES OF SNOW AND SLIGHTLY LIGHTER WIND SPEEDS. HAVE SIDED WITH
THE ECMWF/GFS FOR THE LOW TRACK TONIGHT. IF THE SYSTEM WOULD SLIDE
SLIGHTLY FURTHER EAST...RICHLAND...ADAMS...AND JUNEAU COUNTIES
WOULD LIKELY NEED TO BE UPGRADED TO A WINTER STORM WARNING.
FURTHER TO THE WEST...OVER MUCH OF NORTHEAST IOWA...SOUTHEAST
MINNESOTA...AND WEST CENTRAL INTO NORTH CENTRAL WISCONSIN...SNOW
ACCUMULATIONS OF 6 TO 10 INCHES ARE EXPECTED. ROADS WILL LIKELY
BECOME IMPASSABLE...ESPECIALLY ACROSS THE OPEN AREAS OF SOUTHEAST
MINNESOTA INTO NORTHEAST IOWA FROM THE DRIFTING SNOW.
ALSO...VISIBILITIES WILL BE REDUCED TO ZERO AT TIMES. THE LOW
FINALLY OCCLUDES AND LIFTS NORTH OVER LAKE SUPERIOR LATE THURSDAY
NIGHT INTO EARLY FRIDAY MORNING WITH SNOW TAPERING OFF.
HOWEVER...STRONG NORTHWEST WINDS WILL CONTINUE TO PRODUCE AREAS OF
BLOWING AND DRIFTING SNOW...IMPACTING THE FRIDAY MORNING COMMUTE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 328 PM CST WED FEB 19 2014
COOL HIGH PRESSURE BUILDS BACK INTO THE REGION LATE FRIDAY INTO
SATURDAY AND REMAINS OVER THE REGION THROUGH THE WEEKEND. PLAN ON
QUIET WEATHER WITH HIGHS IN THE TEENS TO LOWER 20S AND LOWS IN THE
SINGLE DIGITS ABOVE AND BELOW ZERO. THE NEXT CHANCE FOR SNOW MOVES
ACROSS THE AREA MONDAY INTO MONDAY NIGHT...BUT LATEST TRENDS
APPEAR THAT IT MAY TRACK JUST SOUTH OF THE FORECAST AREA. COLD
HIGH PRESSURE LOOKS TO MAKE A RETURN TUESDAY NIGHT WITH LOWS
FALLING INTO THE SINGLE DIGITS TO TEENS BELOW ZERO. EVEN COLDER
TEMPERATURES ARE POSSIBLE WEDNESDAY NIGHT WHEN LOWS COULD FALL
INTO THE TEENS BELOW ZERO ACROSS THE ENTIRE FORECAST AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1122 PM CST WED FEB 19 2014
NO SIGNIFICANT FORECAST CHANGES EXPECTED BASED ON THE LATEST MODEL
INFORMATION. REGIONAL RADARS SHOWING THE FIRST WAVE OF
PRECIPITATION OCCURRING OVER SOUTHERN IOWA MOVING NORTHEAST. THE
20.00Z NAM AND 20.03Z HRRR SHOW THE BULK OF THIS PRECIPITATION
MOVING PAST THE TAF SITES TO THE SOUTHEAST. STILL EXPECTING SOME
LIGHT PRECIPITATION TO HIT THE TAF SITES AS THIS COMES IN AND THE
CONCERN REMAINS WHETHER THERE WILL BE ICE AVAILABLE IN THE CLOUDS
AND IF THERE IS...WILL THE WARM LAYER ABOVE THE SURFACE BE ENOUGH
FOR COMPLETE OR PARTIAL MELTING. HAVE CONTINUED THE TREND OF
SHOWING LIGHT SNOW WITH A PERIOD OF FREEZING RAIN AND SLEET
POSSIBLE AT KLSE AND INTRODUCED THE FREEZING RAIN THREAT AT KRST
AS WELL. BY MID MORNING...LOW LEVEL TEMPERATURES STILL EXPECTED TO
BE WARM ENOUGH FOR A RAIN/SNOW MIX AT KLSE WHILE PRIMARILY SNOW IS
EXPECTED AT KRST. THIS INITIAL PRECIPITATION SHOULD PRODUCE
PRIMARILY MVFR CONDITIONS. CONDITIONS THEN DETERIORATE RAPIDLY
DURING THE AFTERNOON AS THE STRONG FORCING MOVES IN WITH MODERATE
TO HEAVY SNOW AND IFR CONDITIONS INTO THE EVENING HOURS. ONCE THE
SURFACE LOW MOVES PAST...THE FALLING SNOW WILL START TO DECREASE
IN INTENSITY BUT THE WINDS WILL BECOME STRONG OUT OF THE WEST WITH
GUSTS OF 30 TO 40 KNOTS WHICH WILL PRODUCE BLOWING SNOW AT BOTH
AIRPORTS AND KEEP KRST IN IFR CONDITIONS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 3 AM TO 9 AM CST THURSDAY FOR
WIZ041-042-053-054-061.
WINTER STORM WARNING FROM 9 AM THURSDAY TO 6 AM CST FRIDAY FOR
WIZ017-029-032>034-041-042-053-054-061.
WINTER WEATHER ADVISORY FROM 3 AM THURSDAY TO 6 AM CST FRIDAY
FOR WIZ043-044-055.
MN...WINTER WEATHER ADVISORY FROM 3 AM TO 9 AM CST THURSDAY FOR
MNZ086>088-094>096.
BLIZZARD WARNING FROM 9 AM THURSDAY TO 6 AM CST FRIDAY FOR
MNZ079-086-087-094-095.
WINTER STORM WARNING FROM 9 AM THURSDAY TO 6 AM CST FRIDAY FOR
MNZ088-096.
IA...WINTER WEATHER ADVISORY FROM 3 AM TO 9 AM CST THURSDAY FOR
IAZ008>011-018-019-029-030.
BLIZZARD WARNING FROM 9 AM THURSDAY TO 6 AM CST FRIDAY FOR
IAZ008>010-018-019-029.
WINTER STORM WARNING FROM 9 AM THURSDAY TO 6 AM CST FRIDAY FOR
IAZ011-030.
&&
$$
UPDATE...04
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS DULUTH MN
352 AM CST SAT FEB 22 2014
.SYNOPSIS...
ISSUED AT 339 AM CST SAT FEB 22 2014
SFC/MID LVL LOW NEAR HUDSON BAY HAS A VERY LARGE AND DEEP
CIRCULATION THAT EXTENDS ACROSS ALL OF THE CWA. EXTENSIVE CANOPY OF
CLOUD COVER REMAINS OVER THE REGION ALTHOUGH SLOW CLEARING IS
OCCURRING IN SWRN CORNER OF CWA. OCCASIONAL SNOW SHOWERS HAVE
CONTINUED NEAR THE INTERNATIONAL BORDER..AND JUST EAST OF CWA IN
GOGEBIC COUNTY. LATEST DLHVWP SHOWS 28735KT WINDS NEAR 1.5K FT WHICH
AGREES WITH FCST RAP .5KM AGL. MANY LOCATIONS CONTINUE TO HAVE WELL
MIXED BDRY LYR WITH GUSTY WINDS.
&&
.SHORT TERM...(TODAY THROUGH TOMORROW)
ISSUED AT 339 AM CST SAT FEB 22 2014
LARGE CIRCULATION FROM HUDSON BAY LOW WILL CONTINUE TO AFFECT THE
NORTHLAND THROUGH THE PERIOD. GUSTY WINDS SHOULD PREVAIL AS
DEEPLY STACKED LOW KEEPS A HIGHLY KINEMATIC PATTERN IN PLACE.
STATIONARY NATURE OF MID LVL LOW WILL KEEP A CONSIDERABLE AMOUNT
OF CLOUD COVER OVER NRN AND EASTERN CWA. AMOUNT OF CLEARING IS
LOWER CONFIDENCE ASPECT OF FCST AS ANY SIGNIFICANT CLEARING MAY
ALLOW FOR INSTABILITY CU DEVELOPMENT. SNOW SHOWERS OR FLURRIES ARE
POSSIBLE OVER NRN MN ZONES AND ACROSS NW WISCONSIN SAT AFTN. TEMPS
REMAIN WELL BELOW CLIMO THROUGH THE WEEKEND.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 339 AM CST SAT FEB 22 2014
UNSEASONABLY COLD WEATHER IS EXPECTED TO SETTLE INTO THE NORTHLAND
DURING THE EXTENDED TIME PERIOD...AND REMAIN THERE THROUGHOUT THE
PERIOD. HIGH TEMPERATURES WILL BE SOME 10 TO 20 DEGREES BELOW NORMAL
DURING THE PERIOD...WITH OVERNIGHT LOW TEMPERATURES ON THE ORDER OF
15 TO 25 DEGREES BELOW NORMAL AT TIMES. THIS WILL ENSURE WE CLOSE
OUT THIS MONTH WITH A MAJOR DEPARTURE FROM NORMAL. ON SUNDAY NIGHT
AND MONDAY THERE SHOULD BE A BRIEF WARMUP...BUT IT WILL STILL BELOW
NORMAL. A LOW PRESSURE SYSTEM WILL BRING SOME LIGHT SNOW TO THE
REGION. AT THIS POINT...IT IS POINTING TO AREAS JUST SOUTH OF THE
CWA...BUT THE NEW ECMWF JUST CAME IN WITH SOME LIGHT QPF IN OUR CWA.
MAY NEED TO ADD SOME POPS AT SOME POINT FOR THE CWA. BEHIND THIS
DEPARTING WEAK LOW PRESSURE SYSTEM...A MAJOR ARCTIC AIRMASS WILL
SETTLE INTO THE REGION ON A MAJOR TROUGH SETTING IN OVER THE GREAT
LAKES. IN SUMMARY...TEMPERATURES WILL BE WELL BELOW NORMAL WITH
LITTLE TO NO PRECIPITATION THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1240 AM CST SAT FEB 22 2014
LARGELY VFR CONDITIONS ARE IN STORE FOR THE TAF SITES THROUGHOUT
THE TAF PERIOD. AREAS OF MVFR CIGS/VSBYS DUE TO SNOW SHOWERS WILL
BE POSSIBLE THROUGHOUT THE PERIOD...BUT THEY WILL BE HIT OR MISS
AS THE SNOW SHOWERS WILL BE SCATTERED. AS DRIER AIR GRADUALLY
WORKS ITS WAY IN THE MVFR CIGS/VSBYS WILL BECOME LESS COMMON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 12 -2 11 -9 / 10 10 0 0
INL 10 -4 8 -11 / 20 10 20 20
BRD 12 -6 12 -11 / 10 0 0 10
HYR 14 -5 13 -9 / 10 10 10 20
ASX 15 0 14 -4 / 10 10 10 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SYNOPSIS...CANNON
SHORT TERM...CANNON
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1120 PM CST FRI FEB 21 2014
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 159 PM CST FRI FEB 21 2014
A BROAD CYCLONIC CIRCULATION IS INDICATED BY 12Z MODEL RUNS TO
REMAIN IN PLACE ACROSS MUCH OF THE NORTHERN HALF OF THE NATION
DURING THE PERIOD. THIS WILL RESULT IN TEMPERATURES TRENDING
COLDER THROUGH THE PERIOD WITH A CHANCE OF SNOW COMING INTO THE
AREA SUNDAY NIGHT INTO MONDAY.
A RATHER SHARP THERMAL GRADIENT WAS IN PLACE ACROSS THE REGION
AT 20Z WITH THE BOUNDARY STRETCHING FROM CENTRAL SOUTH DAKOTA
THROUGH NORTHEAST IOWA AND NORTHERN ILLINOIS. A WEAK SURFACE WAVE
IS FORECAST TO TRACK SOUTHEAST ALONG THIS GRADIENT TONIGHT AND
BE OVER CENTRAL ILLINOIS BY SATURDAY MORNING. SHORT RANGE MODELS
INDICATE SOME POTENTIAL FOR LIGHT SNOW NORTH OF THE WAVE LATE
TONIGHT. QPF LOOKS A BIT OVERDONE BY THE RAP COMPARED TO THE LONG
RANGE MODELS BUT HAVE INCLUDED A MENTION OF SCATTERED FLURRIES
FOR NORTHEAST NEBRASKA INTO SOUTHWEST IOWA AS THIS FEATURE MOVES
THROUGH TONIGHT.
THE COLD FRONT ASSOCIATED WITH THE WEAK LOW SINKS SOUTH INTO THE
SOUTHERN PLAINS AND LOWER OHIO VALLEY ON SATURDAY WITH COLD AIR
SLOWLY MOVING SOUTH BEHIND THE FRONT. SOME LIGHT SNOW BREAKS OUT
OVER THE WESTERN HIGH PLAINS SATURDAY AFTERNOON AS UPSLOPE FLOW
DEVELOPS AND CONTINUES SATURDAY NIGHT WITH SOME SPREAD TO THE EAST
INTO SOUTH CENTRAL NEBRASKA ASSOCIATED WITH WEAK ISENTROPIC
FORCING. HAVE BACKED OFF A BIT ON POPS FOR SOUTHWEST PORTION OF
THE FA FOR LATE SATURDAY NIGHT WITH SOME SLIGHT POPS INTO SUNDAY
MORNING AS BETTER FORCING IS EXPECTED TO REMAIN FURTHER WEST.
WEAK CYCLOGENESIS OCCURS OVER SOUTHEAST WYOMING ON SUNDAY AS AN
UPPER WAVE BEGINS TO DROP INTO THE NORTHERN ROCKIES. SOUTHERLY LOW
LEVEL FLOW DEVELOPS OVER THE CENTRAL PLAINS SUNDAY NIGHT IN
RESPONSE TO THIS DEVELOPMENT WITH A STRONG BAROCLINIC ZONE OVER
NORTHERN NEBRASKA BY MONDAY MORNING. A WIDESPREAD AREA OF SNOW
IS LIKELY ALONG AND NORTH OF THIS BOUNDARY SUNDAY NIGHT INTO
MONDAY MORNING. SNOW THEN SPREADS EAST ON MONDAY INTO NORTHERN
IOWA AS THE UPPER WAVE TRACKS TOWARD THE UPPER MIDWEST WITH THE
BETTER CHANCE OF SNOW EXPECTED NORTH OF INTERSTATE 80. MUCH COLDER
AIR WILL ALSO SURGE INTO THE FA BEHIND THIS WAVE ON MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 159 PM CST FRI FEB 21 2014
A COLD WINTER PATTERN WILL CONTINUE THROUGH THE PERIOD. ONE WEAK
WAVE WILL CONTINUE TO DRIFT SOUTHWARD AT THE BEGINNING OF THE
PERIOD...AND WITH H85 TEMPS WELL WITHIN THE DENDRITIC LAYER...COULD
SEE LINGERING FLURRIES MONDAY NIGHT...BUT LITTLE OR NO ACCUMULATION.
OTHERWISE...NORTHERLY FLOW WILL PERSIST TUESDAY AHEAD OF THE FIRST
SURGE OF EVEN COLDER AIR THAT ARRIVES TUESDAY NIGHT AND LINGERS
THROUGH WEDNESDAY...ALTHOUGH WESTERLY FLOW REDEVELOPS WEDNESDAY
WHICH SHOULD KEEP TEMPS IN THE 20S INSTEAD OF THE TEENS. A SECONDARY
SURGE OF COLDER TEMPS ARRIVES BY DAYBREAK THURSDAY AS SURFACE FLOW
AGAIN RETURNS TO THE NORTH/NORTHEAST. THIS SHOULD KEEP TEMPS IN THE
TEENS ON THURSDAY...BUT VERY LITTLE MOISTURE AVAILABLE SO NO CHANCE
OF PRECIP. A WEAK RETURN FLOW TRIES TO DEVELOP ON FRIDAY...BUT TEMPS
SHOULD REMAIN WELL BELOW NORMAL.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1120 PM CST FRI FEB 21 2014
PREVIOUS THINKING REMAINS ON TRACK. STILL EXPECT VFR CONDITIONS
THROUGH THE PERIOD WITH ANY CEILINGS ABOVE 5000 FEET. A COLD FRONT
WILL CONTINUE TO SETTLE SOUTHWARD ACROSS THE AREA WITH LIGHT WINDS
TENDING TO BECOME MORE NORTHERLY SATURDAY MORNING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT
LONG TERM...DEWALD
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
333 AM EST SAT FEB 22 2014
.SYNOPSIS...
HIGH PRESSURE WILL BRING DRIER BUT CONTINUED WARM CONDITIONS INTO
THE AREA TODAY. THIS HIGH WILL MOVE OFFSHORE SUNDAY...FOLLOWED BY
A WEAK COLD FRONTAL PASSAGE SUNDAY NIGHT. SEASONABLE WEATHER IS
EXPECTED FOR EARLY NEXT WEEK. AN ARCTIC FRONT WILL CROSS THE
AREA WEDNESDAY...USHERING IN A RETURN TO MUCH COLDER WEATHER FOR
THE LATTER HALF OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SATURDAY...AS CAN OFTEN BE THE CASE WITH COLD FRONTS
CROSSING THE NC MOUNTAINS...YESTERDAY`S DID NOT COME THROUGH IN
ONE PIECE. IN FACT THE SURFACE WIND SHIFT HAS YET TO ARRIVE IN SE
NORTH CAROLINA AND PLENTY OF MOISTURE REMAINS IN THE LOWEST 500
FEET OF THE ATMOSPHERE. FOG AND LOW STRATUS HAS BEEN THE
RESULT...ALTHOUGH THIS SHOULD CLEAR THE AREA BEFORE SUNRISE AS
NORTHERLY WINDS FINALLY ARRIVE AND ADVECT DEWPOINTS IN THE LOWER
40S DOWN TO THE BEACHES.
A ZONAL MID AND UPPER LEVEL FLOW ACROSS THE SOUTHERN U.S. WILL
CONTINUE THROUGH TONIGHT. A PAIR OF WEAK UPPER DISTURBANCES WILL
MOVE ACROSS THE AREA...THE FIRST THIS MORNING ACROSS NORTH CAROLINA
AND THE SECOND LATE TONIGHT ACROSS THE SOUTH CAROLINA/GEORGIA COAST.
EACH DISTURBANCE WILL HELP INDUCE A WEAK AREA OF SURFACE LOW
PRESSURE TO DEVELOP ALONG THE STALLED FRONT OFFSHORE. THE FIRST LOW
IS DEVELOPING NOW ACROSS NORTH FLORIDA AND IS BEST INDICATED BY THE
EXPANDING AREA OF LOW STRATUS CLOUDS ACROSS COASTAL GEORGIA DUE TO
WINDS BLOWING ACROSS THE FRONT ON THE 295K ISENTROPIC SURFACE
3000-4500 FT UP. THIS ZONE OF LIFT SHOULD ADVECT NORTHEASTWARD THIS
MORNING...PERHAPS SPREADING A FEW HOURS OF LOW CLOUDINESS ACROSS THE
NC/SC BEACHES AND NEARBY COASTAL AREAS. BY NOON ANY LOW CLOUDS
SHOULD BE BACK OFFSHORE AGAIN AS THE LOW SHOOTS BY TO THE EAST.
ASIDE FROM PATCHES OF TRANSLUCENT CIRRUS FROM TIME TO TIME IT SHOULD
BE A NICE DAY WITH HIGHS REACHING THE UPPER 60S AWAY FROM THE
BEACHES.
FOR TONIGHT GOOD RADIATIONAL COOLING DURING THE EVENING SHOULD ALLOW
TEMPERATURES TO FALL INTO THE 40S A FEW HOURS AFTER SUNSET. LOW
CLOUDS MAY BEGIN TO INCREASE FROM THE SOUTHEAST LATE TONIGHT AS THE
SECOND SURFACE LOW DEVELOPS ALONG THE FRONT OFFSHORE. LOWS SHOULD
END UP IN THE LOWER 40S FOR MOST AREAS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...SUNDAY WILL AGAIN FEATURE WELL ABOVE NORMAL
TEMPS FOR LATE FEBRUARY AS SURFACE HIGH PRESSURE EXTENDS NORTH FROM
THE GULF AND MID-LEVEL FLOW PERSISTS FROM THE SW. THIS WILL DRIVE
HIGHS WELL TOWARDS 70...WITH MANY PLACES LIKELY REACHING 70 AWAY
FROM THE COAST. THIS WELL ABOVE NORMAL WARMTH WILL BE SHORT-LIVED
HOWEVER...AS A COLD...BUT DRY...FRONT CROSSES THE CWA SUNDAY NIGHT.
STRONGEST CAA IS DELAYED SOMEWHAT BEHIND THE SURFACE BOUNDARY...SO
MINS SUNDAY NIGHT WILL REMAIN ABOVE NORMAL...FALLING ONLY INTO THE
MID 40S...BUT THEN HIGHS ON MONDAY WILL LIKELY STRUGGLE TO JUST
BELOW...OR RIGHT AT...SEASONABLE NORMS A LITTLE ABOVE 60. THE COOL
HIGH PRESSURE THAT BUILDS OVERHEAD MONDAY WILL QUICKLY MOVE OFFSHORE
AS THE MID-LEVEL FLOW REMAINS PROGRESSIVE...AND THUS RETURN FLOW
DEVELOPS LATE MONDAY NIGHT WHICH KEEPS MINS ONCE AGAIN SLIGHTLY
ABOVE NORMAL...AROUND 40 MOST PLACES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...UNSETTLED WEATHER TO BEGIN THE
EXTENDED...BUT A RETURN TO WINTER APPEARS LIKELY AS VERY COLD AIR
FLOODS BACK INTO THE REGION FOR MID-TO-LATE WEEK.
COASTAL TROUGH WILL TRY TO ADVECT ONSHORE EARLY TUESDAY ON RETURN
FLOW AROUND A DEPARTING HIGH PRESSURE...BUT THIS WILL MOSTLY WASH
OUT AHEAD OF AN ADVANCING LOW PRESSURE AND COLD FRONT WHICH IS
LIKELY TO CROSS THE AREA BY EARLY WEDNESDAY. THE COMBINATION OF
RETURN SURFACE FLOW AND RENEWED RIDGING ALOFT WILL MAKE TUESDAY A
SLIGHTLY ABOVE NORMAL DAY...ALTHOUGH CLOUD COVER WILL SOMEWHAT
INHIBIT TOTAL WARMING. A WAVE OF LOW PRESSURE ALONG THE ADVANCING
COLD FRONT WILL SKIRT OVER OR JUST NORTH OF THE AREA LATE TUESDAY
AND TUESDAY NIGHT...BRINGING INCREASING RAIN CHANCES FOR A SHORT
PERIOD OF TIME AS PWATS RISE TOWARDS 1 INCH AND THETA-E RIDGE
ADVECTS UP THE COAST. MOS P-NUMBERS ARE ALREADY IN THE LIKELY
CATEGORY...AND WILL BUMP POP TOWARDS HIGH CHANCE FOR TUESDAY NIGHT
AND EARLY WEDNESDAY. AS NOTED BY PREVIOUS FORECASTER...COLD AIR WILL
CHASE THIS MOISTURE INTO WEDNESDAY...AND MAY CREATE A P-TYPE ISSUE
AT THE TAIL END OF THIS PRECIP EVENT. ATTM THIS LOOKS LIKE A VERY
SMALL POSSIBILITY AND WILL LEAVE ALL PRECIP AS LIQUID FOR NOW.
THE STORY BEYOND WEDNESDAY WILL BE RENEWED ARCTIC COLD FOR THE
REMAINDER OF THE EXTENDED. ARCTIC FRONT WILL CRASH THROUGH THIS
AREA...WITH 850MB TEMPS PLUMMETING NEARLY 20C BETWEEN TUESDAY NIGHT
AND THURSDAY MORNING! THE EXACT TIMING OF THIS FRONT IS STILL IN
QUESTION...AS THE ECMWF HAS A FASTER PROGRESSION THAN THE GFS. AS
PROGRESSIVE AS THE PATTERN HAS BEEN...FAVOR THE ECMWF SOLUTION WHICH
WOULD MAKE WED A CHILLY DAY...AND WILL DROP HIGHS SLIGHTLY FROM
INHERITED. STILL...THE CORE OF THE COLD AIR FUNNELS INTO THE AREA BY
THURSDAY IN CONJUNCTION WITH A PIECE OF THE CANADIAN VORTEX DROPPING
INTO NEW ENGLAND. THIS WILL LIKELY BRING TEMPS TO WELL BELOW
MID-WINTER NORMS FOR THU/FRI WITH HIGHS AND LOWS 10-15 DEGREES BELOW
NORMAL.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...RESIDUAL LOW-LEVEL MOISTURE ALONG THE COAST IS CONFINED
TO A LAYER BARELY 500 FEET THICK...BUT THIS HAS YIELDED LOW STRATUS
CEILINGS AND AREAS OF GROUND FOG ACROSS SE NORTH CAROLINA AND
COASTAL SOUTH CAROLINA. UNTIL NORTHERLY WINDS ARRIVE BETWEEN 08-10Z
AND PUSH THE FOG/LOW CLOUDS OUT TO SEA WE CAN EXPECT FLIGHT CATEGORY
RESTRICTIONS TO CONTINUE. LIFR CONDITIONS ARE EXPECTED AT TIMES. THE
00Z GFS MODEL WAS OF NO HELP...AND EVEN THE 00Z NAM MODEL DOES NOT
SEE THE MOISTURE WELL ENOUGH TO PRODUCE FOG IN ITS PROGS. THE 02Z
HRRR AND RUC MODELS ARE A LITTLE BETTER...AND MY FORECAST FOLLOWS
THE HRRR RATHER CLOSELY THROUGH 10Z.
EXPECT VFR AFTER DAYBREAK WITH NORTHEAST WINDS AOB 10 KTS...BECOMING
LIGHT AND EASTERLY AFTER 00Z SUNDAY.
EXTENDED OUTLOOK...EXPECT VFR CONDITIONS THROUGH MONDAY. MVFR CIGS
AND RAIN POSSIBLE TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM SATURDAY...LIGHT WEST WINDS THIS MORNING WILL SHIFT
NORTH-NORTHEASTERLY BEFORE DAYBREAK AS THE FINAL PIECE OF
YESTERDAY`S COLD FRONT FINALLY SWEEPS ACROSS THE AREA. UNTIL THE
FRONT ARRIVES...POCKETS OF MOIST AIR LINGERING ACROSS THE
NEARSHORE WATERS COULD CAUSE LOCALLY REDUCED VISIBILITY IN SEA
FOG. THE FRONT WILL DRIFT OFFSHORE LATER TODAY AS LOW PRESSURE
MOVES NORTHEAST ALONG IT. ASIDE FROM A 6-HOUR PERIOD OF STRONGER
NORTHEAST WINDS (15 KNOTS) THIS MORNING AND SOME CLOUDINESS...MOST
OF THE IMPACTS WITH THE LOW WILL REMAIN FARTHER OFFSHORE. A SECOND
AREA OF WEAK LOW PRESSURE WILL DEVELOP ALONG THE FRONT LATE
TONIGHT...WITH LIGHT NORTHEAST WINDS CONTINUING.
WITH SUCH LIGHT WINDS THIS MORNING THE ONLY WAVES ON THE OCEAN ARE
THOSE PRODUCED BY THE STRONG WINDS YESTERDAY. THIS IS A 7 TO 8
SECOND SOUTHEAST SWELL STILL BEING MEASURED AT THE FRYING PAN SHOALS
BUOY AT 5 FEET. THIS SWELL WILL BE OVERLAID BY A SHORTER PERIOD
NORTHEAST CHOP LATER THIS MORNING...WITH TOTAL SEAS INSIDE 20 MILES
OF SHORE AVERAGING 3-5 FEET TODAY AND 3 FEET TONIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...WEAK AND DRY COLD FRONT TO CROSS THE AREA
SUNDAY NIGHT WILL CREATE TWO VASTLY DIFFERENT WIND REGIMES OVER THE
WATERS DURING THE PERIOD. SW WINDS ON SUNDAY AHEAD OF THE COLD FRONT
WILL RISE FROM AROUND 5 KTS...TO 10-15 KTS SUNDAY NIGHT JUST AHEAD
OF THE FROPA. THIS WILL PUSH SEAS UP TO 3-4 FT EARLY MONDAY MORNING.
COLD FRONT LATE SUNDAY NIGHT WILL BE ACCOMPANIED BY A SUDDEN WIND
SHIFT TO THE NORTH MONDAY MORNING AT 10-15 KTS...BEFORE VEERING TO
THE NE AND FALLING TO AROUND 10 KTS LATE. WAVE HEIGHTS WILL REMAIN
AT 3-4 FT ON MONDAY...BUT A CONFUSED SPECTRUM IS LIKELY THE FIRST
HALF OF THE DAY AS NORTHERLY WIND CHOP BEGINS TO DEVELOP OVER THE
RESIDUAL SW WIND WAVES.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...BRIEF HIGH PRESSURE WILL MOVE ACROSS THE
WATERS TUESDAY AND WELL OFFSHORE TUESDAY NIGHT AHEAD OF A WAVE OF
LOW PRESSURE AND STRONG COLD FRONT WHICH WILL MOVE OFFSHORE EARLY
WEDNESDAY. THIS CREATES VARIABLE WIND DIRECTIONS ON
TUESDAY...EVENTUALLY BECOMING SW AT 10-15 KTS TUESDAY NIGHT. THE
WAVE OF LOW PRESSURE WILL MOVE NORTH OF THE LOCAL AREA...BUT THE
SUBSEQUENT ARCTIC FRONT WILL CROSS THE WATERS DIRECTLY...WITH GUSTY
NW WINDS DEVELOPING IN ITS WAKE ON WEDNESDAY...RISING TO 20-25 KTS
WED NIGHT BEFORE SLOWLY EASING BY THE END OF THE PERIOD. WAVE
HEIGHTS WILL BE 3-4 FT MUCH OF THE PERIOD...BUT AMPLIFICATION IS
EXPECTED WED NIGHT ON THE STRONGER WINDS WHEN SEAS WILL JUMP TO 4-6
FT...AND A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...TRA
MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1224 AM EST SAT FEB 22 2014
.SYNOPSIS...
HIGH PRESSURE WILL BRING DRIER AND COOLER AIR INTO THE REGION
OVERNIGHT INTO SATURDAY. THE HIGH WILL MOVE OFFSHORE SUNDAY
FOLLOWED BY A COLD FRONT PASSAGE SUNDAY NIGHT. AN ARCTIC FRONT
WILL OPEN THE DOOR FOR WELL BELOW NORMAL TEMPERATURES TO SPILL
IN FROM CANADA...BEGINNING IN THE MIDDLE OF NEXT WEEK...PERSISTING
INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 1230 AM SATURDAY...THE LEADING EDGE OF THE DRY AIR HAS MADE IT
THROUGH FLORENCE AND DARLINGTON WHERE DEWPOINTS ARE IN THE 30S. THE
STORY IS VERY DIFFERENT TO THE EAST WHERE A VERY SHALLOW LAYER OF
DEWPOINTS IN THE 50S EXTENDING UP TO ONLY 500 FEET AGL HAS YIELDED
FOG AND LOW STRATUS CLOUDS ACROSS LUMBERTON...WILMINGTON AND MYRTLE
BEACH. SYNOPTIC MODELS (GFS AND NAM) ARE OF VERY LITTLE HELP AS THEY
DO NOT SEE THIS SHALLOW AND PRACTICALLY MESOSCALE AREA OF MOISTURE.
THE 02Z HRRR IS THE MODEL OF CHOICE...AS IT AND THE LATEST RUC MODEL
SHOW NORTHERLY WINDS NOT DEVELOPING UNTIL 3-5 AM...SCOURING OUT THE
LOW-LEVEL MOISTURE AND ALLOWING VISIBILITIES/CEILINGS TO FINALLY
IMPROVE. FORECAST LOW TEMPS HAVE BEEN BUMPED UP A LITTLE ALONG THE
COAST AS WELL. PREVIOUS DISCUSSION FROM 900 PM FOLLOWS...
STRONG RUMBLES CONTINUED TO REVERBERATE ACROSS THE GULF STREAM
WATERS THIS EVENING ASSOCIATED WITH A VOLATILE PRE-FRONTAL SQUALL
MAKING CONTINUED EASTWARD PROGRESS. A SOLID LINE OF LIGHTNING
STRIKES ELECTRIFIED AREAS FROM THE ROCKY MAINE BEACHES TO THE MILD
TREASURE COAST OF FLORIDA THIS MID EVENING. CLEARING IS IN THE CARDS
FOR THE CAROLINAS OVERNIGHT ASIDE FROM STREAKING AND THIN CIRRUS
CLOUDS RIDING A RACING SOUTHERN STREAM JET TRACK. AM NOT EXPECTING
SIGNIFICANT IMPACTS ON TEMPERATURES OVERNIGHT DUE TO CLOUDS.
THE ACTUAL COLD FRONT/WIND-SHIFT IS CLEARING OUR FAR INLAND ZONES
AND WILL REACH THE COAST BY OR JUST PRIOR TO MIDNIGHT. WINDS WILL
TEND TO W-NW-N OVERNIGHT BUT POST-FRONTAL WINDS ARE NOT STRONG AND
A STRONG BLUSTERY COLD SURGE IS NOT EXPECTED. TEMPERATURES HOWEVER
WILL BEGIN TO NOTICEABLY COOL AFTER MIDNIGHT...DIPPING IN THE MID
40S AT THE COAST AND UPPER 30S TO NEAR 40 INLAND BY DAYBREAK SAT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...THE WEEKEND LOOKS MUCH DRIER AND CALMER. HIGH
PRESSURE TO THE WEST WILL BUILD OVERHEAD THROUGH SAT AND RIDGE BACK
ACROSS THE FORECAST AREA INTO SUN MORNING AS IT BEGINS TO MOVE
OFFSHORE. A COLD FRONT WILL MOVE ACROSS THE AREA AND OFFSHORE SUN
NIGHT. A WAVE OF LOW PRESSURE WILL DEVELOP ON THE BOUNDARY AS IT
MOVES OFFSHORE. MOISTURE RETURN LOOKS RATHER MEAGER AHEAD OF THE
FRONT AND WILL KEEP POPS BELOW THRESHOLD AT THIS TIME...HOWEVER...IT
IS POSSIBLE A FEW SHOWERS COULD GRAZE THE COAST SUN NIGHT.
TEMPS THIS PERIOD WILL BE MUCH MORE SEASONABLE. HIGHS WILL BE IN THE
60S SAT AND AROUND 70 ON SUN. THE SEABREEZE ON SUN WILL KEEP HIGHS
AT THE BEACHES IN THE MID 60S. LOWS WILL BE IN THE 40S BOTH
NIGHTS...PERHAPS AROUND 50 AT THE COAST.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 345 PM FRIDAY...MODELS IN GENERAL AGREEMENT IN STARTING OFF
THE LONG TERM PERIOD WITH FAST ZONAL FLOW ALOFT EARLY MONDAY. BY
LATE MONDAY AND FOR THE REMAINDER OF THE LONG TERM PERIOD THRU
FRIDAY...FLOW ALOFT WILL BE IN THE PROCESS OF RE-AMPLIFYING ACROSS
THE FORECAST AREA...TO NEARLY BACK TO WHAT HAS TRANSPIRED THRU-OUT
MUCH OF THIS COLD WINTER SEASON ACROSS THE FORECAST AREA.
MEANING...LONG WAVE TROFFING IN THE MID AND UPPER LEVELS TO AFFECT
THE EASTERN 1/3RD TO 1/2 OF THE U.S. THIS WILL ALSO INCLUDE THE
HUDSON BAY VORTEX DROPPING SOUTHWARD TO THE GREAT LAKES REGION BY
THE MID TO LATE WEEK UPCOMING PERIOD. AT THE SAME TIME...THE
WESTERN 1/3RD OF THE U.S. TO EXPERIENCE AMPLIFIED LONGWAVE UPPER
RIDGING.
MODELS AS USUAL WILL HAVE THEIR TIMING ISSUES WITH ONE ANOTHER IN
REGARD TO THE PASSAGE OF SFC FEATURES DURING THIS UPCOMING LONG
TERM PERIOD. BUT...THEY ALL REMAIN SIMILAR WITH THE EVENTUAL
TRANSITION BACK TO THE WELL BELOW NORMAL COLD WEATHER ACROSS THE
ILM CWA BY THE END OF THIS UPCOMING WEEK. FOR MONDAY AND
TUESDAY...A WEAK COLD FRONT WILL PUSH THRU EARLY IN THE PERIOD
BEFORE STALLING SOUTH OF THE FA B4 NEARLY DISSIPATING BY TUESDAY.
A FEW MODELS KEEP THE FRONTS IDENTITY AND RETURN IT TO THE NORTH
AS A WARM FRONT DURING TUESDAY. OTHERWISE...WEAK RIDGING WILL
AFFECT THE REGION. MAX/MIN MON THRU WED MORNING WILL RUN ABOVE
NORMAL WITH A REMOTE CHANCE OF BREAKING 70 DEGREES FOR HIGHS ON
TUE. DURING WED...THE POLAR/ARCTIC COLD FRONT WILL PUSH ACROSS
THE FA...ALONG WITH A DEVELOPING AND RAPIDLY INTENSIFYING SFC LOW
MOVING ALONG IT. PLENTY OF MOISTURE AND AVAILABLE DYNAMICS
TO WARRANT 30-40 POPS ACROSS THE FA. WILL CONTINUE WITH NO PCPN
TYPE ISSUES WITH THIS PCPN EVENT. HOWEVER...IT BARES WATCHING IF
ENOUGH COLD AIR CAN LEACH IN B4 THE DEEPENING LOW DEPARTS...THEN
PCPN TYPE WILL NEED TO BE RE-VISITED.
MODELS ARE SIMILAR...EVEN THIS FAR OUT IN TIME...WITH BELOW OR
POSSIBLY MUCH BELOW NORMAL MAX/MIN TEMPS FOR THU THRU FRI. HAVE
LOWERED THE PREVIOUS FORECAST TEMPS NEARLY A CATEGORY DURING THIS
TIME PERIOD...BUT NOT AS COLD AS SOME GUIDANCE CURRENTLY
ILLUSTRATES.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...RESIDUAL LOW-LEVEL MOISTURE ALONG THE COAST IS CONFINED
TO A LAYER BARELY 500 FEET THICK...BUT THIS HAS YIELDED LOW STRATUS
CEILINGS AND AREAS OF GROUND FOG ACROSS SE NORTH CAROLINA AND
COASTAL SOUTH CAROLINA. UNTIL NORTHERLY WINDS ARRIVE BETWEEN 08-10Z
AND PUSH THE FOG/LOW CLOUDS OUT TO SEA WE CAN EXPECT FLIGHT CATEGORY
RESTRICTIONS TO CONTINUE. LIFR CONDITIONS ARE EXPECTED AT TIMES. THE
00Z GFS MODEL WAS OF NO HELP...AND EVEN THE 00Z NAM MODEL DOES NOT
SEE THE MOISTURE WELL ENOUGH TO PRODUCE FOG IN ITS PROGS. THE 02Z
HRRR AND RUC MODELS ARE A LITTLE BETTER...AND MY FORECAST FOLLOWS
THE HRRR RATHER CLOSELY THROUGH 10Z.
EXPECT VFR AFTER DAYBREAK WITH NORTHEAST WINDS AOB 10 KTS...BECOMING
LIGHT AND EASTERLY AFTER 00Z SUNDAY.
EXTENDED OUTLOOK...EXPECT VFR CONDITIONS THROUGH MONDAY. MVFR CIGS
AND RAIN POSSIBLE TUESDAY AND WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM SATURDAY...THE SMALL CRAFT ADVISORY HAS BEEN ALLOWED
TO EXPIRE...ALTHOUGH THE STRONG WINDS FROM EARLIER TODAY PRODUCED A
HEALTHY 7-8 SECOND SWELL THAT IS NOW THE DOMINANT WAVE COMPONENT
MEASURED AT THE BUOYS. IT WILL TAKE SOME TIME FOR THIS SWELL TO
DIMINISH...AND 3-5 FOOT SEAS WILL CONTINUE INTO DAYBREAK. THE
BIGGEST CHANCE WITH THIS FORECAST WAS TO ADD FOG INTO THE FORECAST
THROUGH ABOUT 4-5 AM. WEBCAMS FROM CAROLINA BEACH AND SOUTHPORT
INDICATE LOW CLOUDS AND SOME AREAS OF FOG PLAGUING THE COAST EARLY
THIS MORNING. PREVIOUS DISCUSSION FROM 900 PM FOLLOWS...
ADVISORIES TO PREVAIL UNTIL MIDNIGHT AS SEAS RECOVER AND GUSTINESS
ABATES. 4-7 FOOT SEAS AND WEST WINDS OF 15-25 KT SHOULD PREVAIL
THROUGH MOST OF THE EVENING. AN EXERCISE CAUTION HEADLINE MAY BE
NEEDED AFTER MIDNIGHT FOR 5 FOOT SEAS OFFSHORE AND POTENTIAL NNW
WIND GUSTS TO 20 KT. STORMS HAVE MOVED EAST OF THE 0-20NM WATERS AND
OVERALL CLEARING IS EXPECTED FOR THE OVERNIGHT PERIOD WITH IMPROVING
MARINE CONDITIONS. ALL LIGHTNING AND TSTM ACTIVITY WILL REMAIN
CONFINED TO...AND EAST OF THE GULF STREAM WATERS OVERNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY
NIGHT/... AS OF 300 PM FRIDAY...WINDS WILL STILL BE FROM THE NE ON
SAT AS HIGH PRESSURE BUILDS ACROSS THE WATERS FROM THE W. AS HIGH
PRESSURE BEGINS TO MOVE OFFSHORE ON SUN...ENE WINDS WILL VEER TO S
AND THEN SW BY DAYS END. THE PASSAGE OF A COLD FRONT WILL SHIFT
WINDS TO THE N OVERNIGHT SUN. NE WINDS WILL STILL BE GUSTY INTO
EARLY SAT AFTERNOON...UP TO 20 KT. THE STRONGEST WINDS THIS PERIOD
ARE EXPECTED IN THE WAKE OF THE COLD FRONT...AND WE WILL BE
NEARING SMALL CRAFT ADVISORY CRITERIA AROUND DAYBREAK MON. SEAS
WILL BE UP TO 4 FT ON SAT AND THEN SUBSIDING TO 3 FT OR LESS SAT
NIGHT AND SUN. SEAS WILL BUILD AGAIN SUN NIGHT...REACHING 5 FT
ACROSS THE OUTER WATERS.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 345 PM FRIDAY...WEAK COLD FRONTAL PASSAGE THAT PUSHES THROUGH
EARLY MONDAY TO STALL AND NEARLY DISSIPATE SOUTH OF THE AREA
WATERS DURING THE DAY MONDAY INTO TUE. WEAK SFC RIDGE AXIS TO
EXTEND/AFFECT THE AREA WATERS THRU TUESDAY. THE AXIS WILL EXTEND
FROM THE NW OFF THE MAINLAND IMMEDIATELY AFTER EARLY MONDAYS
FROPA. THEN...FROM THE EAST FROM A WEAK BUBBLE HIGH OFFSHORE FROM
THE CAROLINA COASTS. A FEW MODELS INDICATE THAT THE STALLED
FRONTAL BOUNDARY MAY STILL EXIST TUESDAY...AND PUSH IT BACK TO THE
NORTH AS A WARM FRONT. TO SUM IT UP...MONDAY AND TUESDAY WILL
FEATURE CHANGING/VEERING WIND DIRECTIONS WITH SPEEDS GENERALLY
AROUND 15 KT OR LESS. SIGNIFICANT SEAS MON THRU TUE WILL GENERALLY
HOLD IN THE 2 TO 4 FOOT OR 3 TO 5 FOOT RANGE. ONSHORE FLOW DURING
TUE WILL KEEP SEAS RATHER ACTIVE...NOT TO THE HEIGHT THAT
WAVEWATCH3 CURRENTLY ILLUSTRATES. BY WED...DEEPENING LOW PRESSURE
ALONG THE APPROACHING AND EVENTUAL PASSAGE OF THE POLAR/ARCTIC
COLD FRONT WILL DRIVE RESULTING WINDS AND SIGNIFICANT SEAS TO AT-
LEAST SCA THRESHOLDS. GALE THRESHOLDS DURING WED REMAIN
POSSIBLE...WITH A FEW OF THE MODELS LOOKED AT...HINT AT RAPIDLY
INTENSIFYING THE SFC LOW CLOSER TO THE CAROLINA WATERS DURING THE
DAY WEDNESDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC/TRA
SHORT TERM...RJD
LONG TERM...DCH
AVIATION...BJR/TRA
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
232 AM CST SAT FEB 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 232 AM CST SAT FEB 22 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED NORTHWEST FLOW FROM EASTERN ALASKA INTO THE CENTRAL PLAINS...
AND THURSDAYS WINTER STORM AS A LARGE UPPER LOW OVER FAR NORTHERN
ONTARIO. THE FORECAST AREA CONTINUES TO BE INFLUENCED BY THE
CIRCULATION AROUND THE LARGE UPPER LOW WITH A SERIES OF WEAK
SHORTWAVES ROTATING AROUND IT MOVING THROUGH THE FORECAST AREA.
PLENTY OF DRY AIR SEEN ON THE 00Z MPX SOUNDING HAS KEPT THESE
SHORTWAVES FROM PRODUCING ANYTHING. IN FACT...OUTSIDE OF SOME LOW
STRATUS NORTH OF HIGHWAY 10 IN WISCONSIN...SKIES ARE MOSTLY CLEAR.
LOW TO MID LEVEL NORTHWEST WINDS AROUND THE LOWS CIRCULATION
CONTINUE TO DRAW COLDER AIR SOUTH OUT OF CENTRAL CANADA INTO THE
FORECAST AREA. 850MB TEMPS AT MPX DROPPED FROM -4C AT 00Z FRIDAY
TO -13C AT 00Z SATURDAY. WELL OFF TO THE NORTHWEST...THERE ARE TWO
IMPORTANT SHORTWAVES OF NOTE WHICH INFLUENCE MONDAYS FORECAST...ONE
OVER NORTHERN ALBERTA AND A SECOND IN THE YUKON.
VERY LITTLE CHANGE IN THE UPPER LEVEL PATTERN IS PROGGED OVER THE
NEXT 24 HOURS. THIS MEANS THE FORECAST AREA WILL CONTINUE TO BE
INFLUENCED BY THE CIRCULATION AROUND THE UPPER AND SURFACE LOWS IN
FAR NORTHERN ONTARIO...ALLOWING A FEED OF DRY...COLD AIR ON
NORTHWEST WINDS TO CONTINUE. MAY HAVE TO KEEP A WATCH FOR SOME
FLURRIES THIS MORNING ACROSS NORTHEAST IOWA AND FAR SOUTHWEST
WI...ASSOCIATED WITH A SHORTWAVE TRACKING FROM SOUTH DAKOTA INTO
NORTHERN ILLINOIS. CURRENTLY THINK THE DRY AIR WILL WIN OUT AND ANY
MEANINGFUL SNOW/FLURRIES WILL STAY TO THE SOUTH.
925MB TEMP PROGS SUGGEST THAT THE HIGHER SUN ANGLE HERE IN LATE
FEBRUARY WILL HELP TO MODIFY SOME OF THE COLD AIR DURING THE DAYTIME
HOURS. STILL...READINGS AT 18Z OF -12 TO -14C AND FRESH SNOW ONLY
SUPPORT HIGHS IN THE MID TEENS TO MID 20S. 925MB WINDS STAYING UP
TONIGHT...ON THE ORDER OF 30 TO 35 KT...WILL HELP KEEP SURFACE WINDS
FROM DECOUPLING. HOWEVER...THESE WINDS DROP TEMPS TO -14 TO -18C BY
12Z SUNDAY. THIS COLDER AIR WILL EASILY ALLOW FOR LOWS IN THE SINGLE
DIGITS ABOVE ZERO...AND EVEN IN THE SINGLE DIGITS BELOW ZERO IN THE
TYPICAL COLD SPOTS. WIND CHILLS COULD GET CLOSE ENOUGH TO WARRANT A
WIND CHILL ADVISORY OVER TAYLOR/CLARK COUNTIES LATE TONIGHT INTO
SUNDAY MORNING. GIVEN WIND CHILLS CURRENTLY FORECAST IN THE 18 TO 23
BELOW ZERO RANGE FOR THAT AREA...WILL LET LATER SHIFTS TO DECIDE ON
THE ADVISORY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 232 AM CST SAT FEB 22 2014
THE RETURN OF ARCTIC AIR REMAINS THE BIG IMPACT ITEM IN THE LONG
TERM...WITH A BRIEF BOUT OF SNOW POSSIBLE MONDAY INTO MONDAY NIGHT.
MODELS CONTINUE TO ADVERTISE THE CURRENT RIDGE OVER THE EASTERN
PACIFIC INTO ALASKA WILL DEVELOP INTO AN OMEGA BLOCK OVER THE NEXT
FEW DAYS...WITH ONLY A SLIGHT MOVEMENT EASTWARD. THIS OMEGA BLOCK
ALLOWS SHORTWAVES OVER THE ARCTIC TO DIVE SOUTH INTO THE NORTHERN
U.S....BRINGING THE ARCTIC AIR WITH THEM. ITS WORTH NOTING THAT
HIGHS OBSERVED ON FRIDAY ACROSS THE NORTHWEST TERRITORIES AND
NUNAVUT REGION WERE IN THE TEENS AND 20S BELOW ZERO. HEADING INTO
LATE NEXT WEEK AND NEXT WEEKEND...A CONSISTENT SIGNAL EXISTS THAT
THE SOUTHERN END OF THE OMEGA BLOCK WILL BREAK DOWN. FOR NOW IT
APPEARS WE WILL STAY INFLUENCED BY TROUGHING AND ARCTIC AIR ACROSS
SOUTHERN CANADA.
THE MAJORITY OF THE SHORTWAVES DROPPING OUT OF THE ARCTIC ARE
SUGGESTED TO HAVE LITTLE IF ANY MOISTURE WITH THEM. THUS...THERE IS
NOT A LOT OF PRECIPITATION FORECAST IN THE LONG TERM. THE LONE
EXCEPTION TO THIS IS ON MONDAY...WHEN THE SHORTWAVES OVER NORTHERN
ALBERTA AND THE YUKON ARE PROGGED TO COME ACROSS THE FORECAST AREA
AS A PHASED SHORTWAVE TROUGH. PRECIPITABLE WATER VALUES ACCORDING
TO THE 22.00Z GFS ARE SUGGESTED TO CLIMB TO 0.20 INCHES...WHICH
COMBINED WITH THE POTENT LOOK OF THE SHORTWAVES SHOULD SQUEEZE OUT
SOME SNOW. THE 22.00Z NAM WAS THE DRIEST OF GUIDANCE...BUT THE WORRY
POSED BY THE MODEL SUGGESTING A DRY SCENARIO KEPT CHANCES FROM GOING
MUCH ABOVE 50. IF IT COMES AROUND TOWARDS A WETTER SCENARIO...
CHANCES CAN BE RAISED. TIMING WISE...MODELS HAVE SLOWED THE
PROGRESSION OF THE SNOW. CONSENSUS SEEMS TO FAVOR SNOW MOVING INTO
LOCATIONS WEST OF THE MISSISSIPPI RIVER DURING THE AFTERNOON...THEN
MARCHING EAST ACROSS THE REST OF THE AREA DURING THE EVENING. AFTER
06Z TUESDAY...MUCH OF THE SNOW LOOKS TO BE OVERWITH. LACK OF
MOISTURE WILL KEEP SNOW AMOUNTS DOWN...BUT WITH SNOW TO WATER RATIOS
NEAR 20 TO 1 SHOULD HELP IN ACCUMULATING ANYWHERE FROM 0.5 TO 2
INCHES OF SNOWFALL.
NOW REGARDING THE COLD. SUNDAY AND MONDAY LOOK PRETTY SIMILAR TO
TODAY WITH REGARDS TO HIGHS...WITH JUST A SLIGHT COOLING EACH DAY AS
COLDER AIR FILTERS IN. A MORE SIGNIFICANT PUSH OF ARCTIC AIR COMES
INTO THE FORECAST AREA TUESDAY INTO TUESDAY NIGHT. IN FACT...925MB
TEMPS FALL FROM -14 TO -18C AT 12Z TUESDAY TO -22 TO -25C BY 12Z
WEDNESDAY. THESE REMAIN PRETTY CONSISTENT...AND IT COMES WITH A
20-40 KT 925MB WIND TOO...SUGGESTING A WIND CHILL ADVISORY IS HIGHLY
LIKELY. A PERIOD OF WARM ADVECTION REMAINS ON TAP TO COME IN ON
WEDNESDAY...THOUGH COUNTER-ACTED FROM A WIND CHILL PERSPECTIVE
BECAUSE OF A BRISK WEST WIND. BEYOND WEDNESDAY...THERE REMAINS SIGNS
OF ANOTHER SIGNIFICANT COLD SHOT LIKE THE ONE TUESDAY NIGHT...BUT
WHEN IS NOW A QUESTION MARK. THE 22.00Z GFS SHOWS THE SHOT COMING IN
ON THURSDAY...SIMILAR TO PAST ECMWF RUNS. HOWEVER...THE 22.00Z ECMWF
NOW SUGGESTS THAT COLD SHOT IS DELAYED UNTIL FRIDAY MORNING. THE BAD
PART ABOUT THE ECMWF IS THAT THE COLD SHOT IS EVEN COLDER TOWARDS
SATURDAY MORNING. FOR NOW STAYED WITH A CONSENSUS FORECAST ON
TEMPERATURES WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. WHICHEVER
SOLUTION PANS OUT...MORE WIND CHILL ADVISORIES ARE LIKELY.
ON A CLIMATE NOTE...BASED ON CURRENT TEMPERATURE FORECASTS...
LA CROSSE WILL END UP 3RD OR 4TH COLDEST FOR THE MONTH OF FEBRUARY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1109 PM CST FRI FEB 21 2014
VERY LITTLE CHANGE IS EXPECTED TO OCCUR OVER THE NEXT 24 HOURS.
HIGH PRESSURE WILL REMAINED CENTERED OVER SOUTHERN SASKATCHEWAN
WITH THE RIDGE AXIS EXTENDING SOUTHEAST INTO IOWA WHILE LOW
PRESSURE REMAINS NEAR HUDSONS BAY. THIS WILL PROVIDE AN EXTENDED
PERIOD OF VFR CONDITIONS AND WITH LITTLE CHANGE IN THE
GRADIENT...THE WINDS WILL CONTINUE TO BE WEST TO NORTHWEST AT
SPEEDS BETWEEN 10 AND 15 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1040 PM CST FRI FEB 21 2014
.UPDATE...A WEAK SHORTWAVE TROUGH OVER SD WILL TRACK ACROSS NRN IL
ON SAT AND HELP INITIATE MID LEVEL FRONTOGENESIS. ALL MODELS WITH
THE EXCEPTION OF THE HRRR DEVELOP A NARROW BAND OF LGT SNOW OVER
NRN IL...WHILE THE HRRR DEVELOPS IT OVER SRN WI. FAIRLY CONFIDENT
THE SNOW WILL REMAIN SOUTH WITH PARTLY CLOUDY TO MO SUNNY SKIES
OVER THE FORECAST AREA.
&&
.AVIATION/06Z TAFS/...LOW LEVEL WIND SHEAR WILL REMAIN POSSIBLE
THROUGH 15Z SAT DUE TO A WLY 40-45 KT LLJ. OTHERWISE VFR
CONDITIONS WILL PREVAIL SAT AND SAT NT.
&&
.PREV DISCUSSION... /ISSUED 248 PM CST FRI FEB 21 2014/
SHORT TERM...
TONIGHT AND SATURDAY...FORECAST CONFIDENCE IS HIGH.
STRONG LOW PRESSURE CONTINUES TO GRADUALLY PULL AWAY FROM THE REGION
THIS AFTERNOON. THE STRONG PRESSURE GRADIENT WILL CONTINUE TO
GRADUALLY WEAKEN INTO TONIGHT...ALLOWING FOR GUSTS TO WEAKEN AROUND
OR BELOW 39 KNOTS AT 21Z...AND TO AROUND 30 KNOTS BY 00Z SATURDAY.
THUS...WILL ALLOW THE WIND ADVISORY TO EXPIRE.
WINDS WILL REMAIN WESTERLY TONIGHT INTO SATURDAY...AS PRESSURE
GRADIENT REMAINS SOMEWHAT TIGHT WITH INFLUENCE OF CANADIAN HIGH
PRESSURE WELL TO THE NORTHWEST. CLOUDS WILL SHIFT NORTHEAST OUT OF
THE AREA BY SUNSET. AREAS OF LOW TO MID LEVEL CLOUDS WILL PASS BY
THE AREA JUST TO THE SOUTH AND SOUTHWEST OF THE AREA TONIGHT INTO
SATURDAY. THIS PERIOD SHOULD BE MOSTLY CLEAR.
COLDER AIR WILL CONTINUE TO POUR INTO THE AREA DURING THIS TIME.
LOWS TONIGHT SHOULD DROP INTO THE SINGLE DIGITS NORTHWEST TO TEENS
SOUTHEAST. HIGHS SATURDAY WILL BE IN THE 20S...HIGHER IN THE
SOUTHEAST.
SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE...HIGH
THE MAIN POLAR JET EXTENDS ACROSS THE MID MISSISSIPPI AND OHIO
VALLEY AREA AT THE BASE OF THE BROAD UPPER CANADIAN TROUGH. 700 MB
DOWNWARD MOTION SATURDAY NIGHT BECOMES WEAK UPWARD DURING THE DAY
SUNDAY. 850/700 MB RELATIVE HUMIDITY IS LOW...ALTHOUGH SOME HIGHER
RH ACROSS THE UPPER GREAT LAKES GETS CLOSE TO THE FOND DU LAC AND
SHEBOYGAN AREA ON SUNDAY.
NOT MUCH CHANGE WITH THE SURFACE HIGH STILL RIDGING THROUGH THE
PLAINS TOWARDS THE MISSISSIPPI RIVER. SURFACE GRADIENT STILL WILL
SUPPORT ENOUGH WIND TO REDUCE WIND CHILLS TO NEAR 5 BELOW TO
10 BELOW SATURDAY NIGHT AND AROUND 5 ABOVE DURING THE DAY.
SUNDAY NIGHT AND MONDAY...FORECAST CONFIDENCE...HIGH
ONE SHORTWAVE MOVES INTO SOUTHEAST CANADA WHILE A SECOND
EXITS THE NORTHERN ROCKIES. 700 MB DOWNWARD MOTION BECOME WEAKLY
UPWARD OVER THE WEST MONDAY AFTERNOON. 700 MB RH INCREASES IN
AREAS WEST OF MADISON BY EVENING...BUT SATURATION IS STILL ALONG
AND WEST OF THE MISSISSIPPI RIVER ON THE NAM. THE GFS AND ECMWF
ARE FASTER AND BRINGS IN LIGHT SNOW TO MUCH OF SOUTHERN WISCONSIN
MONDAY AFTERNOON.
THE SURFACE WINDS FINALLY BECOME LIGHT AS THE SURFACE RIDGE BUILDS
INTO SOUTHERN WISCONSIN MONDAY AFTERNOON.
LONG TERM...
MONDAY NIGHT AND TUESDAY...FORECAST CONFIDENCE HIGH
A MID/UPPER SHORTWAVE MOVES ACROSS WISCONSIN MONDAY NIGHT. THE 00Z
ECMWF IS A LITTLE SLOWER AND FARTHER NORTH. THEN A SECOND
SHORTWAVE MOVES ACROSS THE NORTHERN PLAINS AND APPROACHES THE
UPPER MISSISSIPPI VALLEY TUESDAY.
ANY LIGHT SNOW SHOULD END BY SUNRISE TUESDAY AS HIGH PRESSURE
BUILDS ACROSS THE EASTERN PLAINS TOWARDS THE UPPER MISSISSIPPI
VALLEY.
WEDNESDAY...FORECAST CONFIDENCE...HIGH
THE LARGE MID/UPPER TROUGH CUTS OFF AND DROPS TO JUST NORTH OF
LAKE SUPERIOR.
THE LARGE RIDGE OF HIGH PRESSURE DROPS SOUTH ACROSS THE MIDDLE OF
THE U.S. THICKNESS VALUES DROP TO AROUND 490 TO 510 DECAMETERS
WEDNESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE...HIGH
BOTH THE 12Z GFS AND 00Z ECMWF BRING A SURFACE TROUGH ACROSS
SOUTHERN WISCONSIN WEDNESDAY NIGHT. MOISTURE IS LIMITED WITH ONLY
A FEW HUNDREDTHS MAINLY ON THE GFS.
THEN THE COLD AIR GETS REINFORCED WITH RATHER BRISK NORTHWEST
WINDS THURSDAY. HIGH PRESSURE MOVES ACROSS WISCONSIN THURSDAY
NIGHT AND FRIDAY WITH VERY COLD TEMPERATURES THURSDAY NIGHT.
AVIATION/00Z TAFS/...
SOUTHWEST TO WEST WINDS OF 22 TO 25 KNOTS...GUSTING TO 33 TO 38
KNOTS...WILL GRADUALLY SUBSIDE INTO EARLY TONIGHT ACROSS TAF SITES.
THIS IS IN RESPONSE TO STRONG LOW PRESSURE MOVING FURTHER AWAY FROM
THE REGION. STILL MAY SEE WESTERLY GUSTS TO AROUND 20 KNOTS AT TIMES
ON SATURDAY. MOSTLY CLEAR SKIES ARE EXPECTED TONIGHT AND SATURDAY.
MARINE...
THE GALE WARNING HAS BEEN EXTENDED UNTIL 03Z SATURDAY ACROSS THE
NEARSHORE WATERS OF LAKE MICHIGAN. STRONG PRESSURE GRADIENT WILL
SLOWLY WEAKEN TONIGHT. THIS WILL ALLOW FOR SOUTHWEST TO WEST GUSTS
OF 35 TO 40 KNOTS EARLY THIS EVENING TO WEAKEN TO AROUND 30 KNOTS BY
LATER THIS EVENING. HIGH WAVES OF 3 TO 5 FEET ARE EXPECTED IN ICE
FREE AREAS INTO THIS EVENING...BEFORE DIMINISHING LATER TONIGHT.
A SMALL CRAFT ADVISORY WILL BE NEEDED FOR AT TIME LATER TONIGHT FOR
GUSTY WEST WINDS TO 30 KNOTS. THE PRESSURE GRADIENT WILL REMAIN
FAIRLY TIGHT THROUGH THE WEEKEND...POSSIBLY ALLOWING FOR 25 KNOT
GUSTS TO OCCUR. A SMALL CRAFT ADVISORY MAY BE NEEDED AT TIMES OVER
THE WEEKEND.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 AM CST SUNDAY FOR LMZ643>646.
&&
$$
UPDATE...GEHRING
TONIGHT/SATURDAY AND AVIATION/MARINE...WOOD
SATURDAY NIGHT THROUGH FRIDAY...HENTZ
AREA FORECAST DISCUSSION
NWS DULUTH MN
933 AM CST SAT FEB 22 2014
.UPDATE...
ISSUED AT 930 AM CST SAT FEB 22 2014
ADJUSTED SKY COVER DOWNWARD TO ACCOUNT FOR MORE SUNSHINE THAN
CLOUD COVER ATTM. WILL KEEP AN EYE ON THE CLOUDS N OF THE CANADIAN
BORDER AS SOME ARE JUST S OF THE BORDER. ADDED A MENTION OF
FLURRIES ALONG THE N SHORE WHERE TWM AND BFW HAVE REPORTED
FLURRIES. TIGHT PRESSURE GRADIENT OVER THE FA ATTM WILL KEEP GUSTY
WINDS IN PLAY TODAY.
&&
.SYNOPSIS...
ISSUED AT 339 AM CST SAT FEB 22 2014
SFC/MID LVL LOW NEAR HUDSON BAY HAS A VERY LARGE AND DEEP
CIRCULATION THAT EXTENDS ACROSS ALL OF THE CWA. EXTENSIVE CANOPY OF
CLOUD COVER REMAINS OVER THE REGION ALTHOUGH SLOW CLEARING IS
OCCURRING IN SWRN CORNER OF CWA. OCCASIONAL SNOW SHOWERS HAVE
CONTINUED NEAR THE INTERNATIONAL BORDER..AND JUST EAST OF CWA IN
GOGEBIC COUNTY. LATEST DLH VWP SHOWS 28735KT WINDS NEAR 1.5K FT WHICH
AGREES WITH FCST RAP .5KM AGL. MANY LOCATIONS CONTINUE TO HAVE WELL
MIXED BDRY LYR WITH GUSTY WINDS.
&&
.SHORT TERM...(TODAY THROUGH TOMORROW)
ISSUED AT 339 AM CST SAT FEB 22 2014
LARGE CIRCULATION FROM HUDSON BAY LOW WILL CONTINUE TO AFFECT THE
NORTHLAND THROUGH THE PERIOD. GUSTY WINDS SHOULD PREVAIL AS
DEEPLY STACKED LOW KEEPS A HIGHLY KINEMATIC PATTERN IN PLACE.
STATIONARY NATURE OF MID LVL LOW WILL KEEP A CONSIDERABLE AMOUNT
OF CLOUD COVER OVER NRN AND EASTERN CWA. AMOUNT OF CLEARING IS
LOWER CONFIDENCE ASPECT OF FCST AS ANY SIGNIFICANT CLEARING MAY
ALLOW FOR INSTABILITY CU DEVELOPMENT. SNOW SHOWERS OR FLURRIES ARE
POSSIBLE OVER NRN MN ZONES AND ACROSS NW WISCONSIN SAT AFTN. TEMPS
REMAIN WELL BELOW CLIMO THROUGH THE WEEKEND.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 339 AM CST SAT FEB 22 2014
UNSEASONABLY COLD WEATHER IS EXPECTED TO SETTLE INTO THE NORTHLAND
DURING THE EXTENDED TIME PERIOD...AND REMAIN THERE THROUGHOUT THE
PERIOD. HIGH TEMPERATURES WILL BE SOME 10 TO 20 DEGREES BELOW NORMAL
DURING THE PERIOD...WITH OVERNIGHT LOW TEMPERATURES ON THE ORDER OF
15 TO 25 DEGREES BELOW NORMAL AT TIMES. THIS WILL ENSURE WE CLOSE
OUT THIS MONTH WITH A MAJOR DEPARTURE FROM NORMAL. ON SUNDAY NIGHT
AND MONDAY THERE SHOULD BE A BRIEF WARM UP...BUT IT WILL STILL BELOW
NORMAL. A LOW PRESSURE SYSTEM WILL BRING SOME LIGHT SNOW TO THE
REGION. AT THIS POINT...IT IS POINTING TO AREAS JUST SOUTH OF THE
CWA...BUT THE NEW ECMWF JUST CAME IN WITH SOME LIGHT QPF IN OUR CWA.
MAY NEED TO ADD SOME POPS AT SOME POINT FOR THE CWA. BEHIND THIS
DEPARTING WEAK LOW PRESSURE SYSTEM...A MAJOR ARCTIC AIR MASS WILL
SETTLE INTO THE REGION ON A MAJOR TROUGH SETTING IN OVER THE GREAT
LAKES. IN SUMMARY...TEMPERATURES WILL BE WELL BELOW NORMAL WITH
LITTLE TO NO PRECIPITATION THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 614 AM CST SAT FEB 22 2014
LARGELY VFR CONDITIONS ARE IN STORE FOR THE TAF SITES THROUGHOUT
THE PERIOD...BUT THERE WILL BE AREAS OF MVFR CIGS/VSBYS DUE TO
SCATTERED SNOW SHOWERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 12 -2 11 -9 / 10 10 0 0
INL 10 -4 8 -11 / 20 10 20 20
BRD 13 -6 12 -11 / 10 0 0 10
HYR 15 -5 13 -9 / 10 10 10 20
ASX 15 0 14 -4 / 10 10 10 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SYNOPSIS...CANNON
SHORT TERM...CANNON
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
614 AM CST SAT FEB 22 2014
.UPDATE...
ISSUED AT 614 AM CST SAT FEB 22 2014
UPDATED FOR NEW AVIATION DISCUSSION BELOW.
&&
.SYNOPSIS...
ISSUED AT 339 AM CST SAT FEB 22 2014
SFC/MID LVL LOW NEAR HUDSON BAY HAS A VERY LARGE AND DEEP
CIRCULATION THAT EXTENDS ACROSS ALL OF THE CWA. EXTENSIVE CANOPY OF
CLOUD COVER REMAINS OVER THE REGION ALTHOUGH SLOW CLEARING IS
OCCURRING IN SWRN CORNER OF CWA. OCCASIONAL SNOW SHOWERS HAVE
CONTINUED NEAR THE INTERNATIONAL BORDER..AND JUST EAST OF CWA IN
GOGEBIC COUNTY. LATEST DLHVWP SHOWS 28735KT WINDS NEAR 1.5K FT WHICH
AGREES WITH FCST RAP .5KM AGL. MANY LOCATIONS CONTINUE TO HAVE WELL
MIXED BDRY LYR WITH GUSTY WINDS.
&&
.SHORT TERM...(TODAY THROUGH TOMORROW)
ISSUED AT 339 AM CST SAT FEB 22 2014
LARGE CIRCULATION FROM HUDSON BAY LOW WILL CONTINUE TO AFFECT THE
NORTHLAND THROUGH THE PERIOD. GUSTY WINDS SHOULD PREVAIL AS
DEEPLY STACKED LOW KEEPS A HIGHLY KINEMATIC PATTERN IN PLACE.
STATIONARY NATURE OF MID LVL LOW WILL KEEP A CONSIDERABLE AMOUNT
OF CLOUD COVER OVER NRN AND EASTERN CWA. AMOUNT OF CLEARING IS
LOWER CONFIDENCE ASPECT OF FCST AS ANY SIGNIFICANT CLEARING MAY
ALLOW FOR INSTABILITY CU DEVELOPMENT. SNOW SHOWERS OR FLURRIES ARE
POSSIBLE OVER NRN MN ZONES AND ACROSS NW WISCONSIN SAT AFTN. TEMPS
REMAIN WELL BELOW CLIMO THROUGH THE WEEKEND.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 339 AM CST SAT FEB 22 2014
UNSEASONABLY COLD WEATHER IS EXPECTED TO SETTLE INTO THE NORTHLAND
DURING THE EXTENDED TIME PERIOD...AND REMAIN THERE THROUGHOUT THE
PERIOD. HIGH TEMPERATURES WILL BE SOME 10 TO 20 DEGREES BELOW NORMAL
DURING THE PERIOD...WITH OVERNIGHT LOW TEMPERATURES ON THE ORDER OF
15 TO 25 DEGREES BELOW NORMAL AT TIMES. THIS WILL ENSURE WE CLOSE
OUT THIS MONTH WITH A MAJOR DEPARTURE FROM NORMAL. ON SUNDAY NIGHT
AND MONDAY THERE SHOULD BE A BRIEF WARMUP...BUT IT WILL STILL BELOW
NORMAL. A LOW PRESSURE SYSTEM WILL BRING SOME LIGHT SNOW TO THE
REGION. AT THIS POINT...IT IS POINTING TO AREAS JUST SOUTH OF THE
CWA...BUT THE NEW ECMWF JUST CAME IN WITH SOME LIGHT QPF IN OUR CWA.
MAY NEED TO ADD SOME POPS AT SOME POINT FOR THE CWA. BEHIND THIS
DEPARTING WEAK LOW PRESSURE SYSTEM...A MAJOR ARCTIC AIRMASS WILL
SETTLE INTO THE REGION ON A MAJOR TROUGH SETTING IN OVER THE GREAT
LAKES. IN SUMMARY...TEMPERATURES WILL BE WELL BELOW NORMAL WITH
LITTLE TO NO PRECIPITATION THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 614 AM CST SAT FEB 22 2014
LARGELY VFR CONDITIONS ARE IN STORE FOR THE TAF SITES THROUGHOUT
THE PERIOD...BUT THERE WILL BE AREAS OF MVFR CIGS/VSBYS DUE TO
SCATTERED SNOW SHOWERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 12 -2 11 -9 / 10 10 0 0
INL 10 -4 8 -11 / 20 10 20 20
BRD 12 -6 12 -11 / 10 0 0 10
HYR 14 -5 13 -9 / 10 10 10 20
ASX 15 0 14 -4 / 10 10 10 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...DAP
SYNOPSIS...CANNON
SHORT TERM...CANNON
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
706 AM CST SAT FEB 22 2014
.UPDATE...
ISSUED AT 653 AM CST SAT FEB 22 2014
ANALYSIS OF WATER VAPOR IN CONJUNCTION WITH THE NAM...SREF...UKMET
AND ARF/NMM SOLNS SUGGESTS THE POTENTIAL FOR A COUPLED 500 MB JET
DEVELOPING NEAR OR ACROSS SWRN NEB THIS EVENING. THESE MODELS ARE
THE HEAVY HITTERS WITH QPF ACROSS THE FCST AREA. THE SPEED MAX IS
CURRENTLY ALONG THE COAST OF BRITISH COLUMBIA AND MOVING RAPIDLY
SOUTH AS FCST BY THE NAM. TIMING TOOLS SUGGEST IS COULD REACH ERN
WY BY 18Z WHICH IS MUCH FASTER THAN ANY MODEL SHOWS.
NONETHELESS...IF THIS JET MAX CAN MAINTAIN ITS 75 KT INTENSITY AND
COUPLE WITH THE DEPARTING MIDWEST JET THIS EVENING...HEAVY SNOW
WOULD DEVELOP AS INDICATED BY THE NAM. ITS UNCERTAIN WHY THE
GFS AND ECM DONT SHOW THIS DEVELOPMENT BUT DEPENDING ON THE
LOCATION OF THE COUPLE...NERN COLO/SERN WY/SRN NEB PANHANDLE VS
SWRN NEB...THE POTENTIAL FOR HEAVY SNOW REMAINS UNDER EVALUATION.
THERE ARE NO CHANGES TO THE FCST ATTM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CST SAT FEB 22 2014
THE MODELS...ESPECIALLY THE NAM...ARE ADVERTISING A
FRONTOGENETICALLY FORCED SNOW EVENT LATER TODAY THROUGH SUNDAY
MORNING. THE NAM IS THE STRONGEST WITH THE FRONTOGENESIS AND
RESULTING LIFT. THE LOCATION OF THE SNOW BAND SHOWN BY THE MODELS
APPEARS TO BE TRENDING SOUTH IN THE ECM...GFS...06Z NAM AND GEM
REG FAVORING SWRN NEB SOUTH OF INTERSTATE 80 WHILE THE 03Z
SREF...00Z NAM AND GEMNH MODELS PREFER INTERSTATE 80 AND THEN UP
THE NORTH PLATTE VALLEY. THIS IS A DIFFERENCE OF ABOUT 50 MILES
WHICH IS NORMAL. A BLEND OF THE 06Z NAM AND THE OTHER MODELS
PRODUCED 3 TO 5 INCHES OF SNOW BLENDED ACROSS THE AFOREMENTIONED
AREAS WITH HIGHEST AMOUNTS JUST SOUTH OF INTERSTATE 80 IN LINCOLN
COUNTY.
THE COBB SNOW TO LIQUID METHODOLOGY USING THE NAM AND GFS IN THE
800-600 MB LAYER PRODUCED A 19 TO 1 RATIO IN THE 00Z RUNS BUT THE
06Z NAM CAME IN AROUND 17 TO 1. SINCE 19 TO 1 IS VERY HIGH...17 TO
1 WAS USED WHICH IS CLOSER CLIMATOLOGY.
THE NAM VISIBILITY PRODUCT SUGGESTS VISIBILITY FALLING TO 1/2
MILE AT TIMES. MEANWHILE FOLDED THETA E AND DEEP LIFT IN A
SATURATED DENDRITIC LAYER SUGGESTS A PERIOD OF INCH AN HOUR
ACCUMULATION. A WINTER WEATHER ADVISORY IS IN PLACE FOR THIS
EVENT WHERE 3 INCHES OR MORE SNOW IS FORECAST.
OTHERWISE...THE MAINSTREAM MODELS HAVE NOT CAPTURED THE RESIDENT
SFC MOISTURE THIS MORNING WHICH MAY BE THE REASON SOME SOLNS LIKE
THE ECM ARE VERY DRY. A BLEND OF THE HRRR AND RAP WAS USED FOR
DEW POINTS TODAY AND THE 08Z RAP SHOWS PCPN FILLING IN ACROSS
SWRN NEB THIS EVENING LIKE THE 06Z NAM SHOWED. A WEAK ARCTIC
FRONT...CURRENTLY NEAR KHON...WILL MOVE PART WAY INTO THE FCST
AREA TODAY INDUCING UPSLOPE FLOW AND THIS SHOULD POOL LOW LEVEL
MOISTURE ACROSS SWRN NEB.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 351 AM CST SAT FEB 22 2014
ONGOING SNOW ACROSS SOUTHWEST NEBRASKA WILL BE DIMINISHING SUNDAY
MORNING AS THE NORTHWEST FLOW CONTINUES TO PUSH THE DISTURBANCE
TO THE SOUTHEAST. HOWEVER A SECOND DISTURBANCE WILL BE QUICK TO
MOVE TOWARDS THE CWA BY SUNDAY AFTERNOON. THIS NEXT WAVE MODELS
HAVE DECENT AGREEMENT WITH A MORE NORTHERN TRACK...COMPARED TO
THE FIRST WAVE. BY SUNDAY AFTERNOON SNOW WILL BE ON THE INCREASE
ACROSS NW NEB WHICH WILL PROGRESS EAST...ACROSS NORTH
CENTRAL...SUNDAY NIGHT BEFORE DIMINISHING ON MONDAY. MODELS SHOW
BEST LIFT NEAR THE NEB/S DAKOTA BORDER SUNDAY NIGHT...AHEAD OF A
140 PLUS KT JET STREAK AT 300 MB. PWATS INCREASE TO GREATER THAN
0.3 INCHES...WITH A FGEN BAND TO RESULT IN DECENT WINDOW FOR SNOW
PRODUCTION...WITH AROUND A 17:1 RATIO. SNOW TOTALS OF 2 TO 3
INCHES LOOK LIKELY...HOWEVER WILL NEED TO MONITOR AS IT WOULD NOT
TAKE MUCH TO INCREASE THIS TO 4 OR 5 INCHES WHICH WOULD RESULT IN
THE NEED FOR AN ADVISORY.
BY MONDAY NIGHT INTO TUESDAY YET ANOTHER DISTURBANCE WILL BE
CROSSING THE HIGH PLAINS. THIS TIME MODELS FAVOR A SOUTHERN
TRACK...BACK OVER THE SOUTHERN PANHANDLE INTO SW NEB. POPS ONLY
IN THE LOW CHANCE CATEGORY AS MODEL SPREAD HAS INCREASED...ALONG
WITH AVAILABLE MOISTURE. COLD DRIER AIR...WITH ARCTIC HIGH
PRESSURE DRIFTING SOUTH ACROSS THE NORTHERN PLAINS. THIS HAS THE
POTENTIAL TO EITHER PUSH THE SNOW FURTHER SOUTH...OR BRING DRIER
AIR WHICH WILL RESULT IN LESS SNOW REACHING THE GROUND. STAY
TUNED TO AS CHANGES TO AMOUNTS ARE EXPECTED.
TEMPERATURES TO START OFF THE WEEK WILL BE BELOW NORMAL AS
SNOW/CLOUDS KEEP TEMPS FROM SEEING MUCH OF A DIURNAL SWING. HIGHS
GENERALLY SHOULD HOLD IN THE 20S TO MID 30S. SW NEB MAY PUSH
CLOSE TO 40 ON MONDAY WITH A LITTLE MORE SUN INBETWEEN SYSTEMS.
BY TUESDAY NIGHT THE ARCTIC HIGH PRESSURE WILL BUILD OVERHEAD.
LOWS AS SKIES CLEAR IN THE SINGLE DIGITS...ALTHOUGH WITH A SNOW
PACK TEMPS COULD DIP BELOW ZERO. RECORDS ARE STILL IN THE DOUBLE
DIGIT BELOW ZERO...SO LOWS IN THE SINGLE DIGITS BELOW ZERO ARE
STILL EASY TO HIT...ESPECIALLY IF SKIES CLEAR EARLY IN THE NIGHT
WITH A FRESH SNOW COVER.
ARCTIC HIGH SLIDES EAST BY WED...MEANWHILE MODELS TRY TO BUILD
THE WESTERN RIDGE SLOWLY TO THE EAST. STILL LOOKING MAINLY DRY
WITH THE STORM TRACK OVER THE GREAT LAKES. HIGHS BELOW NORMAL AS
WE GO THROUGH MID TO LATE WEEK...ALTHOUGH LESS CONFIDENCE IN
TEMPS BY THE END OF THE WEEK. LATEST MEX GUIDANCE IS WARMER IN
THE EXTENDED...HOWEVER THE ECMWF GUIDANCE RECYCLES A SECOND HIGH
PRESSURE AND COLD AIR ACROSS THE HIGH PLAINS. EXAMPLE OF RANGE
INCLUDE FRIDAY MAX T GUIDANCE OF EITHER 42 FROM THE MEX OR 21
FROM THE EC FOR KLBF. EVEN THE ENSEMBLE RANGE FROM BOTH MODELS IS
HIGH...WITH HIGHS RANGING FROM THE 40S TO THE TEENS. FORECAST
UNCHANGED FROM THE ALLBLEND AND WILL WAIT TO SEE WHICH SIDE OF
THE AISLE WE END UP...ALTHOUGH THIS TYPE OF PATTERN CAN BE
FAVORABLE OF A LARGE SPREAD ACROSS THE CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 526 AM CST SAT FEB 22 2014
MVFR ACROSS NRN NEB ALONG KVTN-KANW-KONL IS EXPECTED TO MOVE
SLOWLY SOUTH THIS MORNING AND PERHAPS MIX OUT TO A VFR CIG NEAR
OVC035 AS INDICATED IN THE NAM MODEL. THE RAP MODEL DOES NOT SHOW
THIS SO THERE IS UNCERTAINTY IN THE FORECAST.
THE MODEL CONSENSUS SHOWS MVFR IN SNOW DEVELOPING THIS AFTERNOON
ACROSS NWRN NEB WHICH SHOULD SPREAD SOUTH AND EAST LATE IN THE
AFTERNON AND TONIGHT. THE SNOW SHOULD BECOME MODERATE TONIGHT WITH
IFR/LIFR BECOMING FAIRLY WIDESPREAD BY 03Z...SOUTH OF A LINE FROM
KIEN TO KTIF TO KBBW.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 PM CST /5 PM MST/ THIS EVENING TO
NOON CST /11 AM MST/ SUNDAY FOR NEZ022-023-035-036-056>059-070-
071.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
527 AM CST SAT FEB 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CST SAT FEB 22 2014
THE MODELS...ESPECIALLY THE NAM...ARE ADVERTISING A
FRONTOGENETICALLY FORCED SNOW EVENT LATER TODAY THROUGH SUNDAY
MORNING. THE NAM IS THE STRONGEST WITH THE FRONTOGENESIS AND
RESULTING LIFT. THE LOCATION OF THE SNOW BAND SHOWN BY THE MODELS
APPEARS TO BE TRENDING SOUTH IN THE ECM...GFS...06Z NAM AND GEM
REG FAVORING SWRN NEB SOUTH OF INTERSTATE 80 WHILE THE 03Z
SREF...00Z NAM AND GEMNH MODELS PREFER INTERSTATE 80 AND THEN UP
THE NORTH PLATTE VALLEY. THIS IS A DIFFERENCE OF ABOUT 50 MILES
WHICH IS NORMAL. A BLEND OF THE 06Z NAM AND THE OTHER MODELS
PRODUCED 3 TO 5 INCHES OF SNOW BLENDED ACROSS THE AFOREMENTIONED
AREAS WITH HIGHEST AMOUNTS JUST SOUTH OF INTERSTATE 80 IN LINCOLN
COUNTY.
THE COBB SNOW TO LIQUID METHODOLOGY USING THE NAM AND GFS IN THE
800-600 MB LAYER PRODUCED A 19 TO 1 RATIO IN THE 00Z RUNS BUT THE
06Z NAM CAME IN AROUND 17 TO 1. SINCE 19 TO 1 IS VERY HIGH...17 TO
1 WAS USED WHICH IS CLOSER CLIMATOLOGY.
THE NAM VISIBILITY PRODUCT SUGGESTS VISIBILITY FALLING TO 1/2
MILE AT TIMES. MEANWHILE FOLDED THETA E AND DEEP LIFT IN A
SATURATED DENDRITIC LAYER SUGGESTS A PERIOD OF INCH AN HOUR
ACCUMULATION. A WINTER WEATHER ADVISORY IS IN PLACE FOR THIS
EVENT WHERE 3 INCHES OR MORE SNOW IS FORECAST.
OTHERWISE...THE MAINSTREAM MODELS HAVE NOT CAPTURED THE RESIDENT
SFC MOISTURE THIS MORNING WHICH MAY BE THE REASON SOME SOLNS LIKE
THE ECM ARE VERY DRY. A BLEND OF THE HRRR AND RAP WAS USED FOR
DEW POINTS TODAY AND THE 08Z RAP SHOWS PCPN FILLING IN ACROSS
SWRN NEB THIS EVENING LIKE THE 06Z NAM SHOWED. A WEAK ARCTIC
FRONT...CURRENTLY NEAR KHON...WILL MOVE PART WAY INTO THE FCST
AREA TODAY INDUCING UPSLOPE FLOW AND THIS SHOULD POOL LOW LEVEL
MOISTURE ACROSS SWRN NEB.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 351 AM CST SAT FEB 22 2014
ONGOING SNOW ACROSS SOUTHWEST NEBRASKA WILL BE DIMINISHING SUNDAY
MORNING AS THE NORTHWEST FLOW CONTINUES TO PUSH THE DISTURBANCE
TO THE SOUTHEAST. HOWEVER A SECOND DISTURBANCE WILL BE QUICK TO
MOVE TOWARDS THE CWA BY SUNDAY AFTERNOON. THIS NEXT WAVE MODELS
HAVE DECENT AGREEMENT WITH A MORE NORTHERN TRACK...COMPARED TO
THE FIRST WAVE. BY SUNDAY AFTERNOON SNOW WILL BE ON THE INCREASE
ACROSS NW NEB WHICH WILL PROGRESS EAST...ACROSS NORTH
CENTRAL...SUNDAY NIGHT BEFORE DIMINISHING ON MONDAY. MODELS SHOW
BEST LIFT NEAR THE NEB/S DAKOTA BORDER SUNDAY NIGHT...AHEAD OF A
140 PLUS KT JET STREAK AT 300 MB. PWATS INCREASE TO GREATER THAN
0.3 INCHES...WITH A FGEN BAND TO RESULT IN DECENT WINDOW FOR SNOW
PRODUCTION...WITH AROUND A 17:1 RATIO. SNOW TOTALS OF 2 TO 3
INCHES LOOK LIKELY...HOWEVER WILL NEED TO MONITOR AS IT WOULD NOT
TAKE MUCH TO INCREASE THIS TO 4 OR 5 INCHES WHICH WOULD RESULT IN
THE NEED FOR AN ADVISORY.
BY MONDAY NIGHT INTO TUESDAY YET ANOTHER DISTURBANCE WILL BE
CROSSING THE HIGH PLAINS. THIS TIME MODELS FAVOR A SOUTHERN
TRACK...BACK OVER THE SOUTHERN PANHANDLE INTO SW NEB. POPS ONLY
IN THE LOW CHANCE CATEGORY AS MODEL SPREAD HAS INCREASED...ALONG
WITH AVAILABLE MOISTURE. COLD DRIER AIR...WITH ARCTIC HIGH
PRESSURE DRIFTING SOUTH ACROSS THE NORTHERN PLAINS. THIS HAS THE
POTENTIAL TO EITHER PUSH THE SNOW FURTHER SOUTH...OR BRING DRIER
AIR WHICH WILL RESULT IN LESS SNOW REACHING THE GROUND. STAY
TUNED TO AS CHANGES TO AMOUNTS ARE EXPECTED.
TEMPERATURES TO START OFF THE WEEK WILL BE BELOW NORMAL AS
SNOW/CLOUDS KEEP TEMPS FROM SEEING MUCH OF A DIURNAL SWING. HIGHS
GENERALLY SHOULD HOLD IN THE 20S TO MID 30S. SW NEB MAY PUSH
CLOSE TO 40 ON MONDAY WITH A LITTLE MORE SUN INBETWEEN SYSTEMS.
BY TUESDAY NIGHT THE ARCTIC HIGH PRESSURE WILL BUILD OVERHEAD.
LOWS AS SKIES CLEAR IN THE SINGLE DIGITS...ALTHOUGH WITH A SNOW
PACK TEMPS COULD DIP BELOW ZERO. RECORDS ARE STILL IN THE DOUBLE
DIGIT BELOW ZERO...SO LOWS IN THE SINGLE DIGITS BELOW ZERO ARE
STILL EASY TO HIT...ESPECIALLY IF SKIES CLEAR EARLY IN THE NIGHT
WITH A FRESH SNOW COVER.
ARCTIC HIGH SLIDES EAST BY WED...MEANWHILE MODELS TRY TO BUILD
THE WESTERN RIDGE SLOWLY TO THE EAST. STILL LOOKING MAINLY DRY
WITH THE STORM TRACK OVER THE GREAT LAKES. HIGHS BELOW NORMAL AS
WE GO THROUGH MID TO LATE WEEK...ALTHOUGH LESS CONFIDENCE IN
TEMPS BY THE END OF THE WEEK. LATEST MEX GUIDANCE IS WARMER IN
THE EXTENDED...HOWEVER THE ECMWF GUIDANCE RECYCLES A SECOND HIGH
PRESSURE AND COLD AIR ACROSS THE HIGH PLAINS. EXAMPLE OF RANGE
INCLUDE FRIDAY MAX T GUIDANCE OF EITHER 42 FROM THE MEX OR 21
FROM THE EC FOR KLBF. EVEN THE ENSEMBLE RANGE FROM BOTH MODELS IS
HIGH...WITH HIGHS RANGING FROM THE 40S TO THE TEENS. FORECAST
UNCHANGED FROM THE ALLBLEND AND WILL WAIT TO SEE WHICH SIDE OF
THE AISLE WE END UP...ALTHOUGH THIS TYPE OF PATTERN CAN BE
FAVORABLE OF A LARGE SPREAD ACROSS THE CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 526 AM CST SAT FEB 22 2014
MVFR ACROSS NRN NEB ALONG KVTN-KANW-KONL IS EXPECTED TO MOVE
SLOWLY SOUTH THIS MORNING AND PERHAPS MIX OUT TO A VFR CIG NEAR
OVC035 AS INDICATED IN THE NAM MODEL. THE RAP MODEL DOES NOT SHOW
THIS SO THERE IS UNCERTAINTY IN THE FORECAST.
THE MODEL CONSENSUS SHOWS MVFR IN SNOW DEVELOPING THIS AFTERNOON
ACROSS NWRN NEB WHICH SHOULD SPREAD SOUTH AND EAST LATE IN THE
AFTERNON AND TONIGHT. THE SNOW SHOULD BECOME MODERATE TONIGHT WITH
IFR/LIFR BECOMING FAIRLY WIDESPREAD BY 03Z...SOUTH OF A LINE FROM
KIEN TO KTIF TO KBBW.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 PM CST /5 PM MST/ THIS EVENING TO
NOON CST /11 AM MST/ SUNDAY FOR NEZ022-023-035-036-056>059-070-
071.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
944 AM CST SAT FEB 22 2014
.UPDATE...
ISSUED AT 944 AM CST SAT FEB 22 2014
TEMPERATURE CURVE STILL LOOKS GOOD ATTM AND CONTINUE TO SEE WIND
CHILL VALUES INCREASE TO ABOVE CRITERIA...SO WILL EXPIRE THE WIND
CHILL ADVISORY AS PLANNED. OTHERWISE...REST OF FORECAST ON TARGET.
UPDATE ISSUED AT 643 AM CST SAT FEB 22 2014
WIND CHILLS ARE LOWEST THIS MORNING IN THE DEVILS LAKE BASIN AT
AROUND -30...WITH VALUES APPROACHING -25 ACROSS MUCH OF THE REST
OF THE CURRENT ADVISORY. WILL NOT MAKE ANY CHANGES TO THE ADVISORY
FOR THIS UPDATE AND THE REST OF THE FORECAST IS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 305 AM CST SAT FEB 22 2014
A QUIET PERIOD IS EXPECTED THROUGH THE WEEKEND...WITH TEMPS/CLOUDS THE
MAIN SHORT TERM FOCUS...FOLLOWED BY LIGHT SNOW POTENTIAL ON
MONDAY.
08Z WATER VAPOR IMAGERY REVEALED CONTINUED NORTHWESTERLY FLOW INTO
THE NORTHERN PLAINS UPSTREAM FROM THE DEEP STACKED LOW PRESSURE
SYSTEM NORTH OF LAKE SUPERIOR. THE BAND OF CLOUD COVER EXTENDING
INTO THE NORTHEAST PORTION OF THE FORECAST AREA HAS SLOWLY SHIFTED
NORTHEAST DURING THE OVERNIGHT HOURS WITH SOME LIGHT SNOW
CONTINUING TOWARDS BAUDETTE. SO FAR...WIND CHILLS HAVE STRUGGLED
TO DROP DOWN TO CRITERIA...EXCEPT FOR A FEW SPOTS IN THE DEVILS
LAKE BASIN...BUT STILL EXPECT MORE LOCALES TO APPROACH -25 WIND
CHILLS INTO THE EARLY MORNING HOURS.
FOR TODAY...TEMPS SHOULD BE QUITE SIMILAR TO YESTERDAY WITH
COMPARABLE 925 MB TEMPS AROUND -15C. THUS...HIGHS IN THE SINGLE
DIGITS...TO PERHAPS LOW TEENS IN THE SOUTHWESTERN FORECAST
AREA...ARE EXPECTED. WINDS WILL AGAIN BE BREEZY...WITH A DECENT
PRESSURE GRADIENT REMAINING BETWEEN THE SFC LOW TO THE NORTHEAST
AND HIGH PRESSURE CENTERED OVER WESTERN CANADA. WITH MIXING TO
ABOUT 950 MB OR A BIT ABOVE...WINDS MAY GUST TO 30 MPH...ESPECIALLY
ACROSS THE NORTH. DID KEEP MENTION OF FLURRIES UP TOWARDS LAKE OF
THE WOODS WITH MORE SUN TO THE SOUTHWEST.
TONIGHT...THE 1045 MB SFC HIGH OVER ALBERTA NOSES INTO THE FORECAST
AREA. HOWEVER...WITH WINDS REMAINING UP AROUND 10 KTS...DO NOT
EXPECT A RAPID TEMP DROP...WITH LOWS SIMILAR TO THE PAST FEW NIGHTS
IN THE NEGATIVE SINGLE DIGITS. CLOUD COVER COULD AFFECT TEMPS...WITH
THE MOST LIKELY AREA TO HAVE SOME CLOUDS TOWARDS LAKE OF THE WOODS.
HOWEVER...SOME GUIDANCE TRIES TO DROP CLOUD COVER CURRENTLY OVER
SASKATCHEWAN INTO PARTS OF THE AREA LATER TODAY AND OVERNIGHT.
BASED ON CURRENT FORECAST TEMPS/WINDS...WIND CHILLS MAY APPROACH
THE -25 WIND CHILL CRITERIA THRESHOLD FOR A FEW HOURS...COMPARABLE
TO PREVIOUS NIGHTS. DID NOT KEEP ANY PRECIP MENTION OVER THE LAKE
OF THE WOODS AREA...BUT A FEW FLURRIES ARE POSSIBLE UNDER ANY
LOWER CLOUD DECK.
SUNDAY SHOULD BE VERY SIMILAR TO SATURDAY...WITH CHILLY TEMPS IN THE
SINGLE DIGITS TO LOW TEENS AND BRISK WEST TO NORTHWEST WINDS...AS
WEAK LOW-LEVEL COLD ADVECTION CONTINUES AND 925 MB WINDS REMAIN IN
THE 25-30 KT RANGE. MORE CLOUDS SHOULD LINGER OVER THE FAR
NORTHEAST...WITH PERHAPS A FLURRY OR TWO.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 305 AM CST SAT FEB 22 2014
BY SUNDAY NIGHT AND MONDAY...A 500 MB SHORTWAVE TROUGH WILL APPROACH
FROM THE NORTHWEST. MODELS OVERALL ARE IN DECENT AGREEMENT...WITH
SOME PLACEMENT DIFFERENCES. THE 00Z ECMWF IS A BIT FARTHER NORTH
WITH THE WAVE COMPARED WITH THE GEM/GFS. A BAND OF LIGHT SNOW
ASSOCIATED WITH THE MID-LEVEL FRONTOGENESIS WILL MOVE
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS ON MONDAY...AIDING BY AN
APPROACHING 300 MB JET STREAK. THE 00Z NAM KEEPS THIS BAND PRIMARILY
SOUTH OF THE REGION...WHILE THE ECMWF IS FARTHEST NORTH...AND
WOULD BRING SOME LIGHT SNOW TO MUCH OF THE REGION. GIVEN THIS
UNCERTAINTY...KEPT POPS SIMILAR TO THE PREVIOUS FORECAST...WITH
THE HIGHEST POPS CLOSEST TO THE SD BORDER. HOWEVER...THE SYSTEM
WON/T HAVE MUCH MOISTURE TO WORK WITH...SO ACCUMULATIONS WOULD BE
MINOR.
LOWS ON SUNDAY NIGHT COULD BE A BIT COLDER...WITH LIGHTER WINDS.
HIGHS ON MONDAY ALSO SHOULD BE A FEW DEGREES COLDER...ESPECIALLY
ACROSS THE NORTH...AS 925 MB TEMPS TO NEAR -20C WORK INTO THE
DEVILS LAKE BASIN AND NORTHERN VALLEY BEHIND THE SHORTWAVE.
FOR NOW WENT WITH A DRY FORECAST MONDAY NIGHT...ALTHOUGH THE ECMWF
AND GEM DO HOLD ONTO LIGHT SNOW INTO THE EVENING ACROSS WEST-CENTRAL
MN. OTHERWISE...COLD HIGH PRESSURE WILL BEGIN TO APPROACH FROM THE
WEST...WITH TEMPS FALLING INTO THE NEGATIVE TEENS. CONTINUING WITH
THE THEME THIS WINTER...WIND CHILLS WILL REMAIN A CONCERN BOTH ON
SUNDAY NIGHT AND MONDAY NIGHT.
FOR TUESDAY THROUGH SATURDAY...THE 00Z EURO REMAINS IN GOOD
AGREEMENT WITH PAST RUNS AND GENERALLY COLDER THAN THE 00Z GFS. ALL
HAVE AREA IN NORTH-NORTHWEST FLOW. ONE SHORT WAVE MOVES THRU EARLY
TUESDAY FOLLOWED BY COLD HIGH PRESSURE DROPPING THRU SASK INTO THE
WESTERN DAKOTAS. ANOTHER COLD FRONT DROPS THRU LATER WED WITH
ANOTHER HIGH BEHIND IT AS TEMPERATURES REMAIN SIGNIFICANTLY BELOW
NORMAL. EXPECT DRY WEATHER THRU FRIDAY. VERY LATE IN THE EXTENDED
THERE IS SOME AGREEMENT AMONG THE EURO/GFS FOR A LOW TO DEVELOP OVER
THE CENTRAL ROCKIES AND MOVE EAST. GFS REMAINS MUCH MORE BULLISH
WITH PRECIP IN SRN ND/SD/MN VERSUS A BIT LESS WET EURO. IT IS NOTED
THOUGHT THAT THE 00Z GEM AS HIGH OVER NORTH DAKOTA NEXT SATURDAY
WITH PRECIP SOUTH OF OUR AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 643 AM CST SAT FEB 22 2014
CLOUD SHIELD ON THE WESTERN PERIPHERY OF THE UPPER LOW WEST OF
HUDSON BAY WILL AFFECT PRIMARILY KTVF AND KBJI TODAY INTO TONIGHT.
KBJI HAS BEEN IN THE MVFR RANGE EARLY THIS MORNING...AND THE RAP IS
MAINTAINING THESE LOW CIGS MUCH OF THE DAY. WENT A BIT MORE
OPTIMISTIC WITH VFR CIGS THIS AFTERNOON AT KBJI...BUT CONFIDENCE IS
LOW. OTHERWISE...SOME MID/HIGH CLOUDS WILL APPROACH FROM THE NORTH
AND WEST TODAY...WITH WINDS AGAIN BREEZY FROM THE
NORTHWEST...GUSTING OVER 20 KTS AT TIMES DURING THE DAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ006>008-
014>016-024-026>030-038-039-054.
MN...WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR MNZ001>004-
007-008-013>016-022-023-027>031.
&&
$$
UPDATE...HOPKINS
SHORT TERM...MAKOWSKI
LONG TERM...MAKOWSKI/RIDDLE
AVIATION...MAKOWSKI
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
643 AM CST SAT FEB 22 2014
.UPDATE...
ISSUED AT 643 AM CST SAT FEB 22 2014
WIND CHILLS ARE LOWEST THIS MORNING IN THE DEVILS LAKE BASIN AT
AROUND -30...WITH VALUES APPROACHING -25 ACROSS MUCH OF THE REST
OF THE CURRENT ADVISORY. WILL NOT MAKE ANY CHANGES TO THE ADVISORY
FOR THIS UPDATE AND THE REST OF THE FORECAST IS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 305 AM CST SAT FEB 22 2014
A QUIET PERIOD IS EXPECTED THROUGH THE WEEKEND...WITH TEMPS/CLOUDS THE
MAIN SHORT TERM FOCUS...FOLLOWED BY LIGHT SNOW POTENTIAL ON
MONDAY.
08Z WATER VAPOR IMAGERY REVEALED CONTINUED NORTHWESTERLY FLOW INTO
THE NORTHERN PLAINS UPSTREAM FROM THE DEEP STACKED LOW PRESSURE
SYSTEM NORTH OF LAKE SUPERIOR. THE BAND OF CLOUD COVER EXTENDING
INTO THE NORTHEAST PORTION OF THE FORECAST AREA HAS SLOWLY SHIFTED
NORTHEAST DURING THE OVERNIGHT HOURS WITH SOME LIGHT SNOW
CONTINUING TOWARDS BAUDETTE. SO FAR...WIND CHILLS HAVE STRUGGLED
TO DROP DOWN TO CRITERIA...EXCEPT FOR A FEW SPOTS IN THE DEVILS
LAKE BASIN...BUT STILL EXPECT MORE LOCALES TO APPROACH -25 WIND
CHILLS INTO THE EARLY MORNING HOURS.
FOR TODAY...TEMPS SHOULD BE QUITE SIMILAR TO YESTERDAY WITH
COMPARABLE 925 MB TEMPS AROUND -15C. THUS...HIGHS IN THE SINGLE
DIGITS...TO PERHAPS LOW TEENS IN THE SOUTHWESTERN FORECAST
AREA...ARE EXPECTED. WINDS WILL AGAIN BE BREEZY...WITH A DECENT
PRESSURE GRADIENT REMAINING BETWEEN THE SFC LOW TO THE NORTHEAST
AND HIGH PRESSURE CENTERED OVER WESTERN CANADA. WITH MIXING TO
ABOUT 950 MB OR A BIT ABOVE...WINDS MAY GUST TO 30 MPH...ESPECIALLY
ACROSS THE NORTH. DID KEEP MENTION OF FLURRIES UP TOWARDS LAKE OF
THE WOODS WITH MORE SUN TO THE SOUTHWEST.
TONIGHT...THE 1045 MB SFC HIGH OVER ALBERTA NOSES INTO THE FORECAST
AREA. HOWEVER...WITH WINDS REMAINING UP AROUND 10 KTS...DO NOT
EXPECT A RAPID TEMP DROP...WITH LOWS SIMILAR TO THE PAST FEW NIGHTS
IN THE NEGATIVE SINGLE DIGITS. CLOUD COVER COULD AFFECT TEMPS...WITH
THE MOST LIKELY AREA TO HAVE SOME CLOUDS TOWARDS LAKE OF THE WOODS.
HOWEVER...SOME GUIDANCE TRIES TO DROP CLOUD COVER CURRENTLY OVER
SASKATCHEWAN INTO PARTS OF THE AREA LATER TODAY AND OVERNIGHT.
BASED ON CURRENT FORECAST TEMPS/WINDS...WIND CHILLS MAY APPROACH
THE -25 WIND CHILL CRITERIA THRESHOLD FOR A FEW HOURS...COMPARABLE
TO PREVIOUS NIGHTS. DID NOT KEEP ANY PRECIP MENTION OVER THE LAKE
OF THE WOODS AREA...BUT A FEW FLURRIES ARE POSSIBLE UNDER ANY
LOWER CLOUD DECK.
SUNDAY SHOULD BE VERY SIMILAR TO SATURDAY...WITH CHILLY TEMPS IN THE
SINGLE DIGITS TO LOW TEENS AND BRISK WEST TO NORTHWEST WINDS...AS
WEAK LOW-LEVEL COLD ADVECTION CONTINUES AND 925 MB WINDS REMAIN IN
THE 25-30 KT RANGE. MORE CLOUDS SHOULD LINGER OVER THE FAR
NORTHEAST...WITH PERHAPS A FLURRY OR TWO.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 305 AM CST SAT FEB 22 2014
BY SUNDAY NIGHT AND MONDAY...A 500 MB SHORTWAVE TROUGH WILL APPROACH
FROM THE NORTHWEST. MODELS OVERALL ARE IN DECENT AGREEMENT...WITH
SOME PLACEMENT DIFFERENCES. THE 00Z ECMWF IS A BIT FARTHER NORTH
WITH THE WAVE COMPARED WITH THE GEM/GFS. A BAND OF LIGHT SNOW
ASSOCIATED WITH THE MID-LEVEL FRONTOGENESIS WILL MOVE
SOUTHEASTWARD ACROSS THE NORTHERN PLAINS ON MONDAY...AIDING BY AN
APPROACHING 300 MB JET STREAK. THE 00Z NAM KEEPS THIS BAND PRIMARILY
SOUTH OF THE REGION...WHILE THE ECMWF IS FARTHEST NORTH...AND
WOULD BRING SOME LIGHT SNOW TO MUCH OF THE REGION. GIVEN THIS
UNCERTAINTY...KEPT POPS SIMILAR TO THE PREVIOUS FORECAST...WITH
THE HIGHEST POPS CLOSEST TO THE SD BORDER. HOWEVER...THE SYSTEM
WON/T HAVE MUCH MOISTURE TO WORK WITH...SO ACCUMULATIONS WOULD BE
MINOR.
LOWS ON SUNDAY NIGHT COULD BE A BIT COLDER...WITH LIGHTER WINDS.
HIGHS ON MONDAY ALSO SHOULD BE A FEW DEGREES COLDER...ESPECIALLY
ACROSS THE NORTH...AS 925 MB TEMPS TO NEAR -20C WORK INTO THE
DEVILS LAKE BASIN AND NORTHERN VALLEY BEHIND THE SHORTWAVE.
FOR NOW WENT WITH A DRY FORECAST MONDAY NIGHT...ALTHOUGH THE ECMWF
AND GEM DO HOLD ONTO LIGHT SNOW INTO THE EVENING ACROSS WEST-CENTRAL
MN. OTHERWISE...COLD HIGH PRESSURE WILL BEGIN TO APPROACH FROM THE
WEST...WITH TEMPS FALLING INTO THE NEGATIVE TEENS. CONTINUING WITH
THE THEME THIS WINTER...WIND CHILLS WILL REMAIN A CONCERN BOTH ON
SUNDAY NIGHT AND MONDAY NIGHT.
FOR TUESDAY THROUGH SATURDAY...THE 00Z EURO REMAINS IN GOOD
AGREEMENT WITH PAST RUNS AND GENERALLY COLDER THAN THE 00Z GFS. ALL
HAVE AREA IN NORTH-NORTHWEST FLOW. ONE SHORT WAVE MOVES THRU EARLY
TUESDAY FOLLOWED BY COLD HIGH PRESSURE DROPPING THRU SASK INTO THE
WESTERN DAKOTAS. ANOTHER COLD FRONT DROPS THRU LATER WED WITH
ANOTHER HIGH BEHIND IT AS TEMPERATURES REMAIN SIGNIFICANTLY BELOW
NORMAL. EXPECT DRY WEATHER THRU FRIDAY. VERY LATE IN THE EXTENDED
THERE IS SOME AGREEMENT AMONG THE EURO/GFS FOR A LOW TO DEVELOP OVER
THE CENTRAL ROCKIES AND MOVE EAST. GFS REMAINS MUCH MORE BULLISH
WITH PRECIP IN SRN ND/SD/MN VERSUS A BIT LESS WET EURO. IT IS NOTED
THOUGHT THAT THE 00Z GEM AS HIGH OVER NORTH DAKOTA NEXT SATURDAY
WITH PRECIP SOUTH OF OUR AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 643 AM CST SAT FEB 22 2014
CLOUD SHIELD ON THE WESTERN PERIPHERY OF THE UPPER LOW WEST OF
HUDSON BAY WILL AFFECT PRIMARILY KTVF AND KBJI TODAY INTO TONIGHT.
KBJI HAS BEEN IN THE MVFR RANGE EARLY THIS MORNING...AND THE RAP IS
MAINTAINING THESE LOW CIGS MUCH OF THE DAY. WENT A BIT MORE
OPTIMISTIC WITH VFR CIGS THIS AFTERNOON AT KBJI...BUT CONFIDENCE IS
LOW. OTHERWISE...SOME MID/HIGH CLOUDS WILL APPROACH FROM THE NORTH
AND WEST TODAY...WITH WINDS AGAIN BREEZY FROM THE
NORTHWEST...GUSTING OVER 20 KTS AT TIMES DURING THE DAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ006>008-
014>016-024-026>030-038-039-054.
MN...WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR MNZ001>004-
007-008-013>016-022-023-027>031.
&&
$$
UPDATE...MAKOWSKI
SHORT TERM...MAKOWSKI
LONG TERM...MAKOWSKI/RIDDLE
AVIATION...MAKOWSKI
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
526 AM CST SAT FEB 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 232 AM CST SAT FEB 22 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED NORTHWEST FLOW FROM EASTERN ALASKA INTO THE CENTRAL PLAINS...
AND THURSDAYS WINTER STORM AS A LARGE UPPER LOW OVER FAR NORTHERN
ONTARIO. THE FORECAST AREA CONTINUES TO BE INFLUENCED BY THE
CIRCULATION AROUND THE LARGE UPPER LOW WITH A SERIES OF WEAK
SHORTWAVES ROTATING AROUND IT MOVING THROUGH THE FORECAST AREA.
PLENTY OF DRY AIR SEEN ON THE 00Z MPX SOUNDING HAS KEPT THESE
SHORTWAVES FROM PRODUCING ANYTHING. IN FACT...OUTSIDE OF SOME LOW
STRATUS NORTH OF HIGHWAY 10 IN WISCONSIN...SKIES ARE MOSTLY CLEAR.
LOW TO MID LEVEL NORTHWEST WINDS AROUND THE LOWS CIRCULATION
CONTINUE TO DRAW COLDER AIR SOUTH OUT OF CENTRAL CANADA INTO THE
FORECAST AREA. 850MB TEMPS AT MPX DROPPED FROM -4C AT 00Z FRIDAY
TO -13C AT 00Z SATURDAY. WELL OFF TO THE NORTHWEST...THERE ARE TWO
IMPORTANT SHORTWAVES OF NOTE WHICH INFLUENCE MONDAYS FORECAST...ONE
OVER NORTHERN ALBERTA AND A SECOND IN THE YUKON.
VERY LITTLE CHANGE IN THE UPPER LEVEL PATTERN IS PROGGED OVER THE
NEXT 24 HOURS. THIS MEANS THE FORECAST AREA WILL CONTINUE TO BE
INFLUENCED BY THE CIRCULATION AROUND THE UPPER AND SURFACE LOWS IN
FAR NORTHERN ONTARIO...ALLOWING A FEED OF DRY...COLD AIR ON
NORTHWEST WINDS TO CONTINUE. MAY HAVE TO KEEP A WATCH FOR SOME
FLURRIES THIS MORNING ACROSS NORTHEAST IOWA AND FAR SOUTHWEST
WI...ASSOCIATED WITH A SHORTWAVE TRACKING FROM SOUTH DAKOTA INTO
NORTHERN ILLINOIS. CURRENTLY THINK THE DRY AIR WILL WIN OUT AND ANY
MEANINGFUL SNOW/FLURRIES WILL STAY TO THE SOUTH.
925MB TEMP PROGS SUGGEST THAT THE HIGHER SUN ANGLE HERE IN LATE
FEBRUARY WILL HELP TO MODIFY SOME OF THE COLD AIR DURING THE DAYTIME
HOURS. STILL...READINGS AT 18Z OF -12 TO -14C AND FRESH SNOW ONLY
SUPPORT HIGHS IN THE MID TEENS TO MID 20S. 925MB WINDS STAYING UP
TONIGHT...ON THE ORDER OF 30 TO 35 KT...WILL HELP KEEP SURFACE WINDS
FROM DECOUPLING. HOWEVER...THESE WINDS DROP TEMPS TO -14 TO -18C BY
12Z SUNDAY. THIS COLDER AIR WILL EASILY ALLOW FOR LOWS IN THE SINGLE
DIGITS ABOVE ZERO...AND EVEN IN THE SINGLE DIGITS BELOW ZERO IN THE
TYPICAL COLD SPOTS. WIND CHILLS COULD GET CLOSE ENOUGH TO WARRANT A
WIND CHILL ADVISORY OVER TAYLOR/CLARK COUNTIES LATE TONIGHT INTO
SUNDAY MORNING. GIVEN WIND CHILLS CURRENTLY FORECAST IN THE 18 TO 23
BELOW ZERO RANGE FOR THAT AREA...WILL LET LATER SHIFTS TO DECIDE ON
THE ADVISORY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 232 AM CST SAT FEB 22 2014
THE RETURN OF ARCTIC AIR REMAINS THE BIG IMPACT ITEM IN THE LONG
TERM...WITH A BRIEF BOUT OF SNOW POSSIBLE MONDAY INTO MONDAY NIGHT.
MODELS CONTINUE TO ADVERTISE THE CURRENT RIDGE OVER THE EASTERN
PACIFIC INTO ALASKA WILL DEVELOP INTO AN OMEGA BLOCK OVER THE NEXT
FEW DAYS...WITH ONLY A SLIGHT MOVEMENT EASTWARD. THIS OMEGA BLOCK
ALLOWS SHORTWAVES OVER THE ARCTIC TO DIVE SOUTH INTO THE NORTHERN
U.S....BRINGING THE ARCTIC AIR WITH THEM. ITS WORTH NOTING THAT
HIGHS OBSERVED ON FRIDAY ACROSS THE NORTHWEST TERRITORIES AND
NUNAVUT REGION WERE IN THE TEENS AND 20S BELOW ZERO. HEADING INTO
LATE NEXT WEEK AND NEXT WEEKEND...A CONSISTENT SIGNAL EXISTS THAT
THE SOUTHERN END OF THE OMEGA BLOCK WILL BREAK DOWN. FOR NOW IT
APPEARS WE WILL STAY INFLUENCED BY TROUGHING AND ARCTIC AIR ACROSS
SOUTHERN CANADA.
THE MAJORITY OF THE SHORTWAVES DROPPING OUT OF THE ARCTIC ARE
SUGGESTED TO HAVE LITTLE IF ANY MOISTURE WITH THEM. THUS...THERE IS
NOT A LOT OF PRECIPITATION FORECAST IN THE LONG TERM. THE LONE
EXCEPTION TO THIS IS ON MONDAY...WHEN THE SHORTWAVES OVER NORTHERN
ALBERTA AND THE YUKON ARE PROGGED TO COME ACROSS THE FORECAST AREA
AS A PHASED SHORTWAVE TROUGH. PRECIPITABLE WATER VALUES ACCORDING
TO THE 22.00Z GFS ARE SUGGESTED TO CLIMB TO 0.20 INCHES...WHICH
COMBINED WITH THE POTENT LOOK OF THE SHORTWAVES SHOULD SQUEEZE OUT
SOME SNOW. THE 22.00Z NAM WAS THE DRIEST OF GUIDANCE...BUT THE WORRY
POSED BY THE MODEL SUGGESTING A DRY SCENARIO KEPT CHANCES FROM GOING
MUCH ABOVE 50. IF IT COMES AROUND TOWARDS A WETTER SCENARIO...
CHANCES CAN BE RAISED. TIMING WISE...MODELS HAVE SLOWED THE
PROGRESSION OF THE SNOW. CONSENSUS SEEMS TO FAVOR SNOW MOVING INTO
LOCATIONS WEST OF THE MISSISSIPPI RIVER DURING THE AFTERNOON...THEN
MARCHING EAST ACROSS THE REST OF THE AREA DURING THE EVENING. AFTER
06Z TUESDAY...MUCH OF THE SNOW LOOKS TO BE OVERWITH. LACK OF
MOISTURE WILL KEEP SNOW AMOUNTS DOWN...BUT WITH SNOW TO WATER RATIOS
NEAR 20 TO 1 SHOULD HELP IN ACCUMULATING ANYWHERE FROM 0.5 TO 2
INCHES OF SNOWFALL.
NOW REGARDING THE COLD. SUNDAY AND MONDAY LOOK PRETTY SIMILAR TO
TODAY WITH REGARDS TO HIGHS...WITH JUST A SLIGHT COOLING EACH DAY AS
COLDER AIR FILTERS IN. A MORE SIGNIFICANT PUSH OF ARCTIC AIR COMES
INTO THE FORECAST AREA TUESDAY INTO TUESDAY NIGHT. IN FACT...925MB
TEMPS FALL FROM -14 TO -18C AT 12Z TUESDAY TO -22 TO -25C BY 12Z
WEDNESDAY. THESE REMAIN PRETTY CONSISTENT...AND IT COMES WITH A
20-40 KT 925MB WIND TOO...SUGGESTING A WIND CHILL ADVISORY IS HIGHLY
LIKELY. A PERIOD OF WARM ADVECTION REMAINS ON TAP TO COME IN ON
WEDNESDAY...THOUGH COUNTER-ACTED FROM A WIND CHILL PERSPECTIVE
BECAUSE OF A BRISK WEST WIND. BEYOND WEDNESDAY...THERE REMAINS SIGNS
OF ANOTHER SIGNIFICANT COLD SHOT LIKE THE ONE TUESDAY NIGHT...BUT
WHEN IS NOW A QUESTION MARK. THE 22.00Z GFS SHOWS THE SHOT COMING IN
ON THURSDAY...SIMILAR TO PAST ECMWF RUNS. HOWEVER...THE 22.00Z ECMWF
NOW SUGGESTS THAT COLD SHOT IS DELAYED UNTIL FRIDAY MORNING. THE BAD
PART ABOUT THE ECMWF IS THAT THE COLD SHOT IS EVEN COLDER TOWARDS
SATURDAY MORNING. FOR NOW STAYED WITH A CONSENSUS FORECAST ON
TEMPERATURES WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. WHICHEVER
SOLUTION PANS OUT...MORE WIND CHILL ADVISORIES ARE LIKELY.
ON A CLIMATE NOTE...BASED ON CURRENT TEMPERATURE FORECASTS...
LA CROSSE WILL END UP 3RD OR 4TH COLDEST FOR THE MONTH OF FEBRUARY.
&&
.CLIMATE...COLD FEBRUARY AND WINTER SEASON
ISSUED AT 526 AM CST SAT FEB 22 2014
UPON A MORE DETAILED LOOK AT THE CURRENT TEMPERATURE FORECASTS THRU
THE END OF THE MONTH...LA CROSSE WOULD END WITH WITH A FEB AVERAGE
TEMPERATURE OF 9.4 DEGREES. THIS WOULD TIE WITH 1899 FOR THIRD
COLDEST FEB OF RECORD...BEHIND ONLY FEB OF 1873 AND 1936. THE WINTER
SEASON /DEC-FEB/ WOULD END UP WITH AN AVERAGE TEMPERATURE OF 11.5
DEGREES...FIFTH COLDEST WINTER OF RECORD.
FOR ROCHESTER...FEB WOULD END UP WITH AN AVERAGE TEMPERATURE OF 7.2
DEGREES...FOURTH COLDEST OF RECORD...BEHIND FEB OF 1917...1936 AND
1979. THE WINTER SEASON /DEC-FEB/ WOULD END UP WITH AN AVERAGE
TEMPERATURE OF 9.0 DEGREES...TIED FOR FIFTH COLDEST WINTER OF RECORD.
THIS WOULD BE THE COLDEST WINTER IN 35 YEARS. ONE WOULD HAVE TO GO
BACK TO THE WINTERS OF 1976-1977...1977-1978 AND 1978-1979 TO FIND A
COMPARABLY COLD WINTER AT BOTH ROCHESTER AND LA CROSSE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 526 AM CST SAT FEB 22 2014
VERY LITTLE CHANGE IS EXPECTED AT THE TAF SITES THRU TODAY AND
TONIGHT...INTO SUN/SUN NIGHT. HIGH PRESSURE OVER SASKAT/ALB WITH
RIDGING INTO IA WILL MOVE LITTLE DURING THE NEXT COUPLE DAYS. THIS
WILL PROVIDE AN EXTENDED PERIOD OF GOOD VFR CONDITIONS. WITH LITTLE
CHANGE IN THE PRESSURE GRADIENT OVER THE REGION...WINDS WILL
CONTINUE TO BE WEST TO NORTHWEST AT SPEEDS OF 10 TO 15 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
CLIMATE......RRS
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
348 PM CST SAT FEB 22 2014
.DISCUSSION...
300 PM...FORECAST CONCERNS INCLUDE A FEW INCHES OF SNOW ACROSS THE
FAR SOUTHEAST CWA THIS EVENING...A FEW INCHES OF SNOW ACROSS THE
ENTIRE AREA MONDAY NIGHT...AND THE RETURN OF ARCTIC AIR NEXT WEEK.
BAND OF PRECIP HAS DEVELOPED OVER THE FAR SOUTHEAST CWA THIS
AFTERNOON AND THIS HAS BEEN SHOWN FAIRLY WELL AND CONSISTENTLY ON
THE SHORT TERM/HI RES GUIDANCE. THE CONTINUED TREND IS TO HAVE
THIS BAND PUSH SOUTHEAST OF THE CWA DURING THE MID EVENING HOURS.
ONLY CHANGE FROM THE UPDATE EARLIER TODAY IS TO TIGHTEN THE POP
GRADIENT A BIT WITH THE A SLIGHT CHANCE OF SNOW ABOUT TO THE
KANKAKEE RIVER...DRY NORTH OF THERE. TIMING-WISE...ITS POSSIBLE
THAT THIS BAND COULD DRIFT SOUTHEAST OF THE CWA SOONER RATHER THAN
LATER AND SHOULD THAT HAPPEN...AMOUNTS COULD BE A BIT LOWER WITH 1
TO 3 INCHES CURRENTLY EXPECTED GENERALLY SOUTH OF A PIPER CITY TO
A RENSSELAER LINE.
A RIDGE OF HIGH PRESSURE WILL BUILD FROM THE NORTHERN PLAINS
TONIGHT TO THE SOUTHERN LAKES AND OHIO VALLEY SUNDAY INTO SUNDAY
NIGHT. THIS WILL MARK THE BEGINNING OF A DOWNWARD TREND IN TEMPS
AS HIGHS ON SUNDAY ONLY REACH THE MID/UPPER 20S WITH HIGHS A FEW
DEGREES LOWER AGAIN ON MONDAY. HOWEVER...DRY CONDITIONS ARE
EXPECTED THROUGH MONDAY AFTERNOON.
THE NEXT CHANCE OF SNOW HAS BEEN DELAYED SLIGHTLY TO MONDAY NIGHT
AND HAVE GENERALLY FOLLOWED THE ECMWF WHICH HAS BEEN THE MOST
CONSISTENT AND SHOWS A SWATH OF QPF OF A TENTH OF AN INCH OR SO.
GIVEN THE COLD TEMPS DURING THIS TIME PERIOD...THE SNOW WILL BE
QUITE DRY/FLUFFY AND A FEW INCHES OF ACCUMULATION STILL APPEAR ON
TRACK AND HAVE INCREASED POPS BACK TO LIKELY FOR THIS TIME PERIOD.
WITH THE SLOWER ARRIVAL...LIGHT SNOW MAY PERSIST INTO TUESDAY
MORNING AND HAVE INTRODUCED LOW CHANCE POPS.
FIRST PUNCH OF COLD AIR THEN ARRIVES TUESDAY/TUESDAY NIGHT AS
LOWS DROP INTO THE LOW SINGLE DIGITS...LIKELY BELOW ZERO ACROSS
THE NORTHWEST CWA. LOW PRESSURE THEN PASSES ACROSS THE NORTHERN
LAKES WEDNESDAY AFTERNOON/EVENING WITH A COLD FRONT PUSHING ACROSS
THE REGION WEDNESDAY EVENING. THIS WILL BRING THE SECOND PUNCH OF
COLDER AIR WITH 850MB TEMPS STILL PROGGED INTO THE -22C TO -26C
RANGE. CONTINUED LOW SINGLE DIGITS TO BELOW ZERO TEMPS ARE
EXPECTED BOTH THURSDAY MORNING AND AGAIN FRIDAY MORNING. HIGHS
DURING THIS TIME ARE SOMEWHAT MORE UNCERTAIN DUE TO STRONGER LATE
FEBRUARY SUNSHINE...BUT WILL BE 15-25 DEGREES BELOW NORMAL. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* NONE.
RC
//DISCUSSION...UPDATED 18Z...
GOOD FORCING FOR LIFT NORTH OF A EAST-WEST FRONTAL BOUNDARY ACROSS
SOUTHERN ILLINOIS AND SOUTHERN INDIANA WILL CAUSE A NARROW BAND OF
SNOW TO DEVELOP THIS AFTERNOON AND CONTINUE INTO THE EVENING WELL
SOUTH OF INTERSTATE 80. MID AND HI CLOUDS WILL PREVAIL NORTH OF
THIS SNOW ACROSS ORD/MDW AND ALL OF CHICAGO. MAY SEE A FEW
FLURRIES AS THE MID DECK LOWERS SOMEWHAT... BUT EXPECT CIGS TO
REMAIN ABOVE 4500 FT AND VSBYS P6SM THROUGH THE AFTERNOON AND
EVENING.
HIGH PRESSURE RIDGING INCREASES OVERNIGHT INTO SUNDAY AS A HIGH
BUILDS SOUTHEAST FROM THE PLAINS.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH FOR ALL ELEMENTS.
RC
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHC SNOW...ESPECIALLY LATE.
TUESDAY THROUGH FRIDAY...VFR.
BMD
&&
.MARINE...
148 PM CST
LOW PRESSURE CENTERED NEAR JAMES BAY THIS AFTERNOON CONTINUES TO
PRODUCE WINDS OF 25 TO 30 KT ACROSS THE LAKE THIS AFTERNOON. THIS
LOW WILL GRADUALLY WEAKEN THROUGH THE REMAINDER OF THE WEEKEND.
HOWEVER...WESTERLY WINDS WILL CONTINUE IN THE 20 TO 30 KT RANGE
SUNDAY INTO MONDAY AS THE SURFACE GRADIENT REMAINS ELEVATED IN
ADVANCE OF A BROAD RIDGE OF SURFACE HIGH PRESSURE EXTENDING FROM THE
NORTHERN PLAINS TO THE OHIO VALLEY.
THE NEXT POTENTIAL HEADLINE WORTHY WIND EVENT WILL BE AROUND THE
MIDDLE OF NEXT WEEK. A FEW CLIPPER TYPE SYSTEMS ARE EXPECTED TO DROP
SOUTHEASTWARD ACROSS THE LAKES REGION DURING THIS PERIOD. OF THESE
NUMEROUS CLIPPER SYSTEMS...IT APPEARS THAT A POTENT ONE WILL
DROP ACROSS THE REGION WEDNESDAY NIGHT. THIS SYSTEM COULD PRODUCE A
PERIOD OF SOUTHWESTERLY GALES ON WEDNESDAY...FOLLOWED BY A PERIOD OF
POTENTIALLY HIGH END NORTHWESTERLY GALES IN ITS WAKE WEDNESDAY NIGHT
INTO THURSDAY. WITH ANOTHER DEEP ARCTIC SURGE OF COLD AIR EXPECTED
IN THE WAKE OF THIS SECOND CLIPPER...THERE WILL ALSO LIKELY BE
SIGNIFICANT FREEZING SPRAY IN CONJUNCTION WITH THE STRONG
NORTHWESTERLY GALES WEDNESDAY NIGHT INTO THURSDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
312 PM CST Sat Feb 22 2014
.DISCUSSION...
ISSUED 300 PM CST Sat Feb 22 2014
Light snow or flurries will return this afternoon and this evening
across most of the area. Measurable snow will be mainly confined
to areas east of I-55, with an inch or two possible closer to
Indiana east of Champaign to Mattoon. The next chance of snow
beyond that appears to be late Monday and Monday night north of
Lincoln to Champaign as the next shortwave moves across N IL.
Dry conditions are expected the remainder of the forecast, with a
dry cold frontal passage Wed night ushering in reinforcing cold
air. Below normal temperatures will prevail for much of this 7-day
forecast.
SHORT TERM...Tonight through Monday.
A band of mid-level frontogenesis north of the stationary front
along I-70 will create some lift that will be enhanced by steep
mid-level lapse rates. That should give the virga a boost in
saturating the lower levels. Flurries already started at PIA
around 2 pm after several hours of virga. Satellite pics show a
baroclinic leaf developing ahead of the weak low pressure over
western Missouri. That low is projected to slide east along the
boundary, which should further enhance the thermo-dynamic forcing.
Meso-scale bands of precip are being advertised by the HRRR and
NMM-east. Light snow will be north of Mattoon to Paris with some
rain or rain-snow mix south of there. We could see an inch or two
of snow where the band of snow rotates and lingers across our
east-central counties...bounded by a line from Decatur to
Hoopeston in the north and Taylorville to Mattoon to Paris in the
south. Even in this late hour, many differences exist with the
placement and intensity of any meso-scale bands of precip late
this afternoon and evening. The GFS and Canadian GEM are more
aggressive with snow, while the NAM is the weakest and the ECMWF
is in the middle. We increased PoPs to categorical and likely in
areas with an inch or more snow possible, with high chance
bordering that. Accums are a tough call with this much dry air to
overcome, but forcing looks strong enough for a short duration to
get some light accumulation.
Precip should progress eastward after midnight, and come to an end
for our counties by 3 am. Colder air will begin to advance into C
IL with the surface high, which should help lows across the north
drop into the teens. Clouds will temper the cool-down, as southern
areas remain in the low 30s.
The 12z Canadian has increased potential for snow or rn/sn as a
shortwave advances east, just north of the stationary front. The
ECMWF is also showing some forcing across our southern counties,
but lower RH and no precip. After coord with offices to the south,
we decided to just add sprinkles and flurries for now on Sunday.
Mostly clear skies for much of Sunday night will provide better
radiational cooling conditions, and lows will respond by dropping
into the single digits north of Peoria.
Monday afternoon and evening will see a 125kt jet at 250mb help
push a shortwave across northern IL. Light snow will develop
mainly north of a line from Rushville to Champaign...with a
dusting along the line to as much as an inch from Galesburg to
El Paso. The NAM is the main outlier with this period of snow,
with much less forcing and farther south than the
GFS/ECMWF/Canadian. We went with consensus and increased PoPs to
likely across Knox to Woodford counties Monday eve.
LONG TERM...Tuesday through Saturday.
We are not expected any measurable precip through the extended
forecast as colder air prevails. A dry cold frontal passage on Wed
night will aid in keeping temps well below normal. Lows will dip
below zero across our northern area on Tuesday night, and get very
close to zero in the north Wed night and Thurs night. Highs will
struggle to climb out of the teens north of I-72 on Wed. Gradual
warming will develop from Thurs to Saturday, but even Saturday`s
highs will range from mid 20s north to mid 30s south, or about 10
to 15 deg below normal.
Shimon
&&
.AVIATION...
ISSUED 1142 AM CST Sat Feb 22 2014
Main concern will be in the 22Z through 06Z time frame, as a band
of precipitation is expected to develop across central Illinois.
Most of the lower levels are dry now, but ceilings lowering to
around 4000 feet west of KPIA indicating some moistening taking
place. High-resolution models showing potentially some light rain
or snow late afternoon near KPIA/KBMI, but main band expected to
set up in the general KSPI-KCMI corridor and persist into mid
evening. Precip type will be a question early on as temperatures
down in this area have reached the 40s, but will drop quickly as
the precipitation becomes steadier. Have hit KCMI and KDEC the
hardest with TEMPO periods of IFR ceilings and visibilities early
this evening when it will be all snow and potential mesoscale
features enhance the precipitation intensity, but this
potentially may extend as far west as KSPI. Most of the snow
should be out of the TAF sites by around 06Z, although it will
still be close to the south.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
150 PM CST SAT FEB 22 2014
.DISCUSSION...
1042 AM CST
WE HAVE MADE SOME CHANGES TO THE FORECAST FOR THIS AFTERNOON AND
EVENING. REGIONAL RADAR IMAGERY THIS MORNING HAS SHOWN SOME DECENT
RETURNS BLOSSOMING ACROSS FAR SOUTHERN IOWA AND INTO WEST CENTRAL
ILLINOIS. THIS ACTIVITY APPEARS TO BE DEVELOPING IN ASSOCIATION
WITH AN ENHANCED BAND OF MID-LEVEL FRONTOGENESIS...WHICH IS
SETTING UP TO THE NORTH OF A STATIONARY WEST TO EAST ORIENTED
FRONTAL BOUNDARY.
THE MORNING RAOBS ACROSS THE AREA...NAMELY AT KDVN AND
KILX...INDICATE THE PRESENCE OF VERY STEEP MID LEVEL LAPSE
RATES...WHICH IS LIKELY ENHANCING THE EFFICIENCY OF THE FRONTAL
SCALE FORCING. HOWEVER...THE PROFILES ARE ALSO FAIRLY DRY IN THE
LOWER LEVELS. THEREFORE...IN SPITE OF THESE DECENT RETURNS
SHOWING UP ON RADAR...MOST IF NOT ALL OF THE CURRENT ACTIVITY IS
LIKELY NOT REACHING THE GROUND YET. OBSERVATIONS ACROSS THIS AREA
HAVE SHOWN A DOWNWARD TREND IN CIG HEIGHTS OVER THE PAST COUPLE OF
HOURS...INDICATING THAT THE PROFILE IS GRADUALLY MOISTENING. SO IT
APPEARS TO BE A MATTER OF TIME BEFORE PRECIP STARTS TO REACH THE
SURFACE.
MODEL GUIDANCE SUGGESTS THAT THIS BAND OF STRONG FRONTOGENESIS
WILL SET UP ACROSS MY SOUTHERN CWA THIS AFTERNOON AND INTO THIS
EVENING...LIKELY SUPPORTING A NARROW BUT RATHER INTENSE AREA OF
FORCING FOR ASCENT THROUGH THE DGZ. GIVEN THIS FORCING SHOULD
CORRESPOND WITH THOSE STEEP MID LEVEL LAPSE RATES NOTED IN THE
MORNING RAOBS...THIS HAS THE POTENTIAL TO RESULT IN BANDING OF
HEAVY SNOW ACROSS AT LEAST A SMALL PORTION OF CENTRAL ILLINOIS
AND INTO INDIANA THIS AFTERNOON AND EVENING.
THE MAIN QUESTION IS WHERE EXACTLY THIS BAND WILL SET UP. MUCH OF
THE HIGH-RES GUIDANCE HAS BEEN JUMPING AROUND A BIT WITH THE
PLACEMENT...SO CONFIDENCE ON THE EXACT AREAS LIKELY TO SEE A BAND
OF HEAVY SNOW REMAINS SOMEWHAT LOW...BUT THE COMBINATION OF
CURRENT OBS AND MODEL GUIDANCE IS POINTING AT SOME OF MY FAR
SOUTHERN COUNTIES...FROM FORD AND IROQUOIS INTO BENTON COUNTY
INDIANA AND POINTS SOUTH. IN THESE AREAS...THERE COULD BE A NARROW
CONFINED BAND OF 2 TO 5 INCHES OF SNOW....WITH MUCH LIGHTER
AMOUNTS OF AN INCH OR TWO POSSIBLE OUTSIDE OF THE BAND OF HEAVIEST
SNOW. GIVEN MY CURRENT CONFIDENCE ON THE PLACEMENT OF THE HEAVIEST
BAND OF SNOW...AND EVEN THE POSSIBILITY THAT IT STAYS JUST SOUTH
OF MY AREA...I HAVE REMAINED RATHER CONSERVATIVE WITH SNOW AMOUNTS
AND POPS IN MY FAR SOUTH. I DID RAISE POPS INTO THE LOW END LIKELY
CATEGORY WITH MENTIONS OF UP TO 2 INCHES OF SNOW IN MY FAR SOUTH.
THIS MAY NEED TO BE REFINED THIS AFTERNOON AS IT BEGINS SETTING UP
ACROSS THE AREA.
KJB
//PREV DISCUSSION...
249 AM CST
TODAY...
RELATIVELY QUIET WEATHER THIS MORNING...WITH BROAD ANTI-CYCLONIC
FLOW POSITIONED OVER THE MID-MISSOURI VALLEY. THIS HAS ALLOWED SKIES
TO BECOME MOSTLY CLEAR FOR THE FORECAST AREA. FURTHER NORTH THE
POTENT LOW PRESSURE REMAINS WRAPPED UP OVER HUDSON BAY WITH A WEAK
LOBE OF VORTICITY PIVOTING EAST ACROSS NORTHERN WISC AND GENERATING
SOME FLURRIES/LGT SNOW EARLY THIS MORNING. IR IMAGERY SHOWS THE NEXT
MID-LVL WAVE TRYING TO PUSH EAST ACROSS THE CENTRAL PLAINS...HOWEVER
BASED ON SFC OBS MOISTURE CONTINUES TO BE LACKING. CLOUD BASES
REMAIN ABOVE 7KFT AGL FOR MOST POINTS ACROSS THE CENTRAL
PLAINS...DESPITE WHAT SOME GUIDANCE INDICATES SHOULD BE SHOWING
FURTHER MOISTENING AND LOWERING WITH SPOTTY PRECIP DEVELOPING. THIS
WAVE IS POISED TO PUSH EAST AND ARRIVE ACROSS THE FORECAST AREA THIS
MORNING. FORCING REMAINS LACKING IN ADDITION THE ENVIRONMENT IS VERY
DRY...SOUNDINGS CONTINUE TO INDICATE SOME MOISTENING...ALTHOUGH
EXPECT THE ANTI-CYCLONIC FLOW TO KEEP PRECIP LIMITED TO SPRINKLES OR
FLURRIES MAINLY SOUTH OF I-88. LOCAL ARW8KM MODEL SUGGESTS JUST SOME
MID-LVL CLOUDS WITH THIS FEATURE.
EXPECT SKIES TO REMAIN P-CLOUDY TODAY...AND WITH TEMPS ALOFT
HOVERING ARND -4 TO -6 DEG C...SFC TEMPS SHUD BE ABLE TO WARM
GENERALLY INTO THE 30S AND POSSIBLY ARND 40 SOUTH OF PONTIAC TO
KANKAKEE.
TONIGHT...
SFC RIDGE REMAINS OVER THE REGION...AS A MID-LVL TROUGH BEGINS TO
PUSH AN ENHANCED LOBE OF VORTICITY INTO THE UPPER MIDWEST. WITH A
BAROCLINIC ZONE ORIENTED FROM CENTRAL MISSOURI STRETCHING NORTHEAST
THROUGH CENTRAL IL/NORTHERN IN...EXPECT THIS WILL PROVIDE SOME ADDED
LIFT/MOISTURE INTO THIS AREA AND MAY HELP TO SPAWN SOME BETTER
ORGANIZED PRECIP TONIGHT FOR THE SOUTHERN PORTIONS OF THE FORECAST
AREA. AS THE MID-LVL VORT LOBE PUSHES EAST...THIS WILL HELP TO PUSH
THE POPS/MOISTURE FURTHER EAST JUST BEFORE DAYBREAK SUN.
TEMPS WILL RADIATE OVERNIGHT INTO THE TEENS...TO LOW 20S CLOSER TO
WHERE PRECIP/CLOUDS ARE EXPECTED TONIGHT ALONG AND SOUTH OF LASALLE
TO VALPARAISO.
CONFIDENCE...HIGH.
SUNDAY THROUGH MONDAY...
500MB RIDGE OFF THE PAC-NW COAST BEGINS TO SHOW SIGNS OF AMPLIFYING
AS THE DOWNSTREAM MID-LVL TROUGH/VORT STRENGTHENS SUN. THE TROUGH
OVER THE GREAT LAKES REGION BECOMES RELATIVELY FLAT...ALLOWING FOR A
BRIEF SEMI-ZONAL FLOW SUN/MON OVER THE FORECAST AREA.
SFC RIDGING BECOMES ELONGATED STRETCHING FROM CENTRAL CANADA
SOUTHEAST THROUGH THE TENN VALLEY. THIS WILL REMAIN OVER THE REGION
SUN/MON...KEEPING PRECIP CHCS TO A MINIMUM. THE MID-LVL VORT MAX
BEGINS TO DIP SOUTH FROM CENTRAL CANADA MON AFTN...WITH GUIDANCE
PROGGING A SFC WAVE DEVELOPING OVER THE LEE-SIDE OF THE ROCKIES.
THIS FEATURE HAS SLOWED IN ARRIVAL ACROSS THE FORECAST AREA UNTIL
CLOSER TO MON NGT/TUE. HAVE PUSHED POPS BACK UNTIL MON NGT...AS THIS
BOUNDARY BECOMES SLIGHTLY MORE ACTIVE. ALTHOUGH EXPECT ONLY LGT SNOW
WITH ANY ACCUMS REMAINING LESS THAN ONE HALF INCH AT THIS TIME.
TEMPS SUN WILL REMAIN UNSEASONABLY COOL...ALTHOUGH HOW THIS SEASON
HAS GONE IT HAS BECOME THE NORM...WITH TEMPS HOVERING IN THE 20S.
THEN FOR MON TEMPS HOLD IN THE UPR TEENS TO LOW 20S.
CONFIDENCE...HIGH.
TUESDAY THROUGH FRIDAY...
THE PATTERN IN THE EXTENDED PERIODS CONTINUES TO FEATURE A RETURN TO
HIGH AMPLITUDE RIDGING OVER WESTERN CANADA/YUKON...RESULTING IN A
DOWNSTREAM DIGGING TROUGH OVER THE GREAT LAKES REGION. GIVEN HOW
ENSEMBLES HAVE CONTINUED TO DEMONSTRATE MINIMAL SPREAD...CONFIDENCE
REMAINS HIGH THAT A SLUG OF ARCTIC AIR WILL BREAK SOUTH FROM THE
ARCTIC CIRCLE AND SLIDE SOUTH ACROSS CENTRAL CANADA TUE. GUIDANCE
CURRENTLY INDICATES 850MB THERMAL TROUGH OF -20 TO -24 DEG C
ARRIVING OVER THE FORECAST AREA TUE NGT/WED...ACCOMPANIED BY A
ROBUST SFC RIDGE POISED TO PUSH INTO THE CENTRAL PLAINS AND MAINTAIN
A NORTH LLVL FLOW WITH COLD AIR ADVECTING INTO NORTHERN IL/NORTHWEST
IN MID/LATE WEEK. THIS SUGGESTS TEMPS WED WILL STRUGGLE TO WARM
BEYOND THE SINGLE DIGITS...POSSIBLY REACHING THE LOW TEENS. THIS
SHOULD BE SIMILAR FOR THUR.
LATE WEEK THE SFC RIDGE WILL DRIFT SOUTH...ALLOWING LLVL FLOW TO
TURN WEST TO SOUTHWEST AND BRIEFLY ALLOW TEMPS TO WARM BACK INTO THE
TEENS/LOW 20S FRI. HOWEVER ENSEMBLES SUGGEST THIS MAY ONLY BE
TEMPORARY. THE MID-LVL VORT RETROGRADES...WITH A SECONDARY SURGE OF
ARCTIC AIR POISED TO RETURN FOR THE FOLLOWING WEEKEND. AT THIS TIME
MOST OF THE EXTENDED PERIODS WILL REMAIN DRY FROM PERSISTING SFC
RIDGING.
CONFIDENCE IN TEMPS...HIGH.
CONFIDENCE IN DRY WX FOR MOST OF THE EXTENDED...MEDIUM.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CHANCE OF FLURRIES THROUGH THE AFTERNOON... WHILE ANY
ACCUMULATIONG SNOW WILL STAY WELL SOUTH OF THE TERMINALS.
* CIGS WILL REMAIN VFR AND VSBYS UNRESTRUCTED THROUGH TONIGHT.
* WINDS FROM THE WEST WILL OCCASIONALLY GUST THIS AFTERNOON... AND
EASE BACK TO CONSISTANTLY BELOW 10 KTS TONIGHT.
ED F
//DISCUSSION...UPDATED 18Z...
GOOD FORCING FOR LIFT NORTH OF A EAST-WEST FRONTAL BOUNDARY ACROSS
SOUTHERN ILLINOIS AND SOUTHERN INDIANA WILL CAUSE A NARROW BAND OF
SNOW TO DEVELOP THIS AFTERNOON AND CONTINUE INTO THE EVENING WELL
SOUTH OF INTERSTATE 80. MID AND HI CLOUDS WILL PREVAIL NORTH OF
THIS SNOW ACROSS ORD/MDW AND ALL OF CHICAGO. MAY SEE A FEW
FLURRIES AS THE MID DECK LOWERS SOMEWHAT... BUT EXPECT CIGS TO
REMAIN ABOVE 4500 FT AND VSBYS P6SM THROUGH THE AFTERNOON AND
EVENING.
HIGH PRESSURE RIDGING INCREASES OVERNIGHT INTO SUNDAY AS A HIGH
BUILDS SOUTHEAST FROM THE PLAINS.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE THAT ACCUMULATING SNOW WILL STAY SOUTH OF
ORD/MDW.
* HIGH CONFIDENCE IN REMAINING FORECAST ELEMENTS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHC SNOW...ESPECIALLY LATE.
TUESDAY THROUGH FRIDAY...VFR.
BMD
&&
.MARINE...
148 PM CST
LOW PRESSURE CENTERED NEAR JAMES BAY THIS AFTERNOON CONTINUES TO
PRODUCE WINDS OF 25 TO 30 KT ACROSS THE LAKE THIS AFTERNOON. THIS
LOW WILL GRADUALLY WEAKEN THROUGH THE REMAINDER OF THE WEEKEND.
HOWEVER...WESTERLY WINDS WILL CONTINUE IN THE 20 TO 30 KT RANGE
SUNDAY INTO MONDAY AS THE SURFACE GRADIENT REMAINS ELEVATED IN
ADVANCE OF A BROAD RIDGE OF SURFACE HIGH PRESSURE EXTENDING FROM THE
NORTHERN PLAINS TO THE OHIO VALLEY.
THE NEXT POTENTIAL HEADLINE WORTHY WIND EVENT WILL BE AROUND THE
MIDDLE OF NEXT WEEK. A FEW CLIPPER TYPE SYSTEMS ARE EXPECTED TO DROP
SOUTHEASTWARD ACROSS THE LAKES REGION DURING THIS PERIOD. OF THESE
NUMEROUS CLIPPER SYSTEMS...IT APPEARS THAT A POTENT ONE WILL
DROP ACROSS THE REGION WEDNESDAY NIGHT. THIS SYSTEM COULD PRODUCE A
PERIOD OF SOUTHWESTERLY GALES ON WEDNESDAY...FOLLOWED BY A PERIOD OF
POTENTIALLY HIGH END NORTHWESTERLY GALES IN ITS WAKE WEDNESDAY NIGHT
INTO THURSDAY. WITH ANOTHER DEEP ARCTIC SURGE OF COLD AIR EXPECTED
IN THE WAKE OF THIS SECOND CLIPPER...THERE WILL ALSO LIKELY BE
SIGNIFICANT FREEZING SPRAY IN CONJUNCTION WITH THE STRONG
NORTHWESTERLY GALES WEDNESDAY NIGHT INTO THURSDAY.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1142 AM CST Sat Feb 22 2014
.DISCUSSION...
ISSUED 1035 AM CST Sat Feb 22 2014
Extensive band of altocumulus showing up on regional radar
mosaics, from along the Iowa/Missouri border east to near
Danville. Nothing is reaching the ground yet, as there are still
pretty good temperature/dew point spreads in this corridor.
However, main concern will be with increase in isentropic lift
through the afternoon, as frontogenesis takes place across
southern Missouri into southeast Illinois. While the NAM keeps
things dry through the afternoon, the higher resolution models
such as the RAP, HRRR and Hi-Res-NMM show development of light
precipitation in a couple areas, one north of I-74 and the other
from about Danville southwest through Springfield. The GFS has
been significant more robust with this, indicating around 1/3 inch
of precipitation while the other models are more in the order of a
tenth inch or so depending on mesoscale features. Some of the
lower levels on forecast soundings are rather dry, which could
hold off the precip a bit but also cool the column more quickly to
support a changeover to snow. Have increased PoP`s to around
40-50% east of the Illinois River and north of I-70 for this
afternoon and will need to monitor trends closely for
precipitation type.
Geelhart
&&
.AVIATION...
ISSUED 1142 AM CST Sat Feb 22 2014
Main concern will be in the 22Z through 06Z time frame, as a band
of precipitation is expected to develop across central Illinois.
Most of the lower levels are dry now, but ceilings lowering to
around 4000 feet west of KPIA indicating some moistening taking
place. High-resolution models showing potentially some light rain
or snow late afternoon near KPIA/KBMI, but main band expected to
set up in the general KSPI-KCMI corridor and persist into mid
evening. Precip type will be a question early on as temperatures
down in this area have reached the 40s, but will drop quickly as
the precipitation becomes steadier. Have hit KCMI and KDEC the
hardest with TEMPO periods of IFR ceilings and visibilities early
this evening when it will be all snow and potential mesoscale
features enhance the precipitation intensity, but this
potentially may extend as far west as KSPI. Most of the snow
should be out of the TAF sites by around 06Z, although it will
still be close to the south.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 215 AM CST Sat Feb 22 2014
Weak shortwave that pushed across the area late last evening
produced a few sprinkles over parts of central and east central
Illinois. That wave has shifted off to our east early this morning
with skies clearing from northwest to southeast. However, another
disturbance seen on the water vapor loop over the northern Rockies
with clouds on the increase over parts of western Iowa. At the surface,
a frontal boundary stretched from northern Illinois west through west
central Iowa. This feature is expected to push across our area today
into this evening bringing the threat for some light precipitation.
SHORT TERM...Today through Monday
Main forecast concerns this period were with the upstream shortwave
and its affect on the forecast area with respect to timing and
coverage of precip later this morning or early this afternoon, and
then with precip type issues for tonight.
Deep trof that brought the active weather to our area on Thursday
as north of Lake Superior early this morning with a broad cyclonic
flow prevalent at 500 mb over the Great Lakes. Models coming in line
with respect to the shortwave to our northwest this morning and the
placement of the frontal boundary currently to our northwest. The front
should slide southeast into the area today as the upper wave approaches
from the northwest, setting up a period of light overrunning precip
to the north of the boundary, especially for this afternoon into tonight.
Models have trended a bit more aggressive with the 700-500 mb forcing
for this time period and have thrown out a bit more QPF across the area
as well. Not really sure where this is all coming from as the deeper
moisture has been displaced well off to our east and southeast. However,
as the shortwave drops southeast into the mean long wave trof position,
we should see a bit of amplification with the upper system resulting
in better low and mid level forcing, which may be able to squeeze
out a tenth to two tenths of an inch of QPF.
Forecast soundings off the NAM-WRF suggest a rain snow mix possible
in the north, with soundings too warm to support anything but light
rain this afternoon over the central thru east central areas. As the
frontal boundary slides south of our area by this evening, colder air
will be able to work into the lower levels of the atmosphere which
should change any mix over to light snow from northwest to southeast.
May see around an inch of wet snow over parts of east central Illinois
by later tonight with most of the remainder of the area seeing less
than an inch.
The better 700-500 mb QG forcing and precip threat shifts off to our
east by Sunday morning with another Arctic high situated up across
west central Canada bringing in one of several shots of cold air to
the region over the next week. Today will be the last of the "mild"
days as the colder air moves in starting tonight with temperatures
cooling a few degrees each day heading into Monday. By Monday, another
fast moving shortwave in the northwest flow aloft will approach the
area by evening bringing an increasing chance for light snow to mainly
the north half of the forecast area Monday night, followed by a
reinforcing surge of Arctic air into the middle of next week.
LONG TERM...Tuesday through Friday
Most of the medium range models were on board with the idea of a
another negative height anomaly settling south to near James Bay by
the second half of this forecast period. This should keep our
temperatures well below normal through the period with the main
storm track displaced over the southern Plains eastward through the
Gulf states. Our weather will be coming from the northwest thru most
of this period as shortwaves rotate south and southeast around the
large vortex at 500 mb bringing reinforcing shots of cold air and
chances for light snow or flurries. This far out, timing and magnitude
of these fast moving waves embedded in the northwest flow will be
difficult to forecast so will keep the extended dry for now.
Smith
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1049 AM CST SAT FEB 22 2014
.DISCUSSION...
1042 AM CST
WE HAVE MADE SOME CHANGES TO THE FORECAST FOR THIS AFTERNOON AND
EVENING. REGIONAL RADAR IMAGERY THIS MORNING HAS SHOWN SOME DECENT
RETURNS BLOSSOMING ACROSS FAR SOUTHERN IOWA AND INTO WEST CENTRAL
ILLINOIS. THIS ACTIVITY APPEARS TO BE DEVELOPING IN ASSOCIATION WITH
AN ENHANCED BAND OF MID-LEVEL FRONTOGENESIS...WHICH IS SETTING UP TO
THE NORTH OF A STATIONARY WEST TO EAST ORIENTED FRONTAL BOUNDARY.
THE MORNING RAOBS ACROSS THE AREA...NAMELY AT KDVN AND
KILX...INDICATE THE PRESENCE OF VERY STEEP MID LEVEL LAPSE
RATES...WHICH IS LIKELY ENHANCING THE EFFICIENCY OF THE FRONTAL
SCALE FORCING. HOWEVER...THE PROFILES ARE ALSO FAIRLY DRY IN THE LOWER
LEVELS. THEREFORE...IN SPITE OF THESE DECENT RETURNS SHOWING UP ON
RADAR...MOST IF NOT ALL OF THE CURRENT ACTIVITY IS LIKELY NOT
REACHING THE GROUND YET. OBSERVATIONS ACROSS THIS AREA HAVE SHOWN A
DOWNWARD TREND IN CIG HEIGHTS OVER THE PAST COUPLE OF
HOURS...INDICATING THAT THE PROFILE IS GRADUALLY MOISTENING. SO IT
APPEARS TO BE A MATTER OF TIME BEFORE PRECIP STARTS TO REACH THE
SURFACE.
MODEL GUIDANCE SUGGESTS THAT THIS BAND OF STRONG FRONTOGENESIS WILL
SET UP ACROSS MY SOUTHERN CWA THIS AFTERNOON AND INTO THIS
EVENING...LIKELY SUPPORTING A NARROW BUT RATHER INTENSE AREA OF
FORCING FOR ASCENT THROUGH THE DGZ. GIVEN THIS FORCING SHOULD
CORRESPOND WITH THOSE STEEP MID LEVEL LAPSE RATES NOTED IN THE
MORNING RAOBS...THIS HAS THE POTENTIAL TO RESULT IN BANDING OF HEAVY
SNOW ACROSS AT LEAST A SMALL PORTION OF CENTRAL ILLINOIS AND INTO
INDIANA THIS AFTERNOON AND EVENING.
THE MAIN QUESTION IS WHERE EXACTLY THIS BAND WILL SET UP. MUCH OF
THE HIGH-RES GUIDANCE HAS BEEN JUMPING AROUND A BIT WITH THE
PLACEMENT...SO CONFIDENCE ON THE EXACT AREAS LIKELY TO SEE A BAND OF
HEAVY SNOW REMAINS SOMEWHAT LOW...BUT THE COMBINATION OF CURRENT OBS
AND MODEL GUIDANCE IS POINTING AT SOME OF MY FAR SOUTHERN
COUNTIES...FROM FORD AND IROQUOIS INTO BENTON COUNTY INDIANA AND
POINTS SOUTH. IN THESE AREAS...THERE COULD BE A NARROW CONFINED BAND OF 2
TO 5 INCHES OF SNOW....WITH MUCH LIGHTER AMOUNTS OF AN INCH OR TWO
POSSIBLE OUTSIDE OF THE BAND OF HEAVIEST SNOW. GIVEN MY CURRENT
CONFIDENCE ON THE PLACEMENT OF THE HEAVIEST BAND OF SNOW...AND EVEN
THE POSSIBILITY THAT IT STAYS JUST SOUTH OF MY AREA...I HAVE
REMAINED RATHER CONSERVATIVE WITH SNOW AMOUNTS AND POPS IN MY FAR
SOUTH. I DID RAISE POPS INTO THE LOW END LIKELY CATEGORY WITH
MENTIONS OF UP TO 2 INCHES OF SNOW IN MY FAR SOUTH. THIS MAY NEED TO
BE REFINED THIS AFTERNOON AS IT BEGINS SETTING UP ACROSS THE
AREA.
KJB
&&
.PREV DISCUSSION...
249 AM CST
TODAY...
RELATIVELY QUIET WEATHER THIS MORNING...WITH BROAD ANTI-CYCLONIC
FLOW POSITIONED OVER THE MID-MISSOURI VALLEY. THIS HAS ALLOWED SKIES
TO BECOME MOSTLY CLEAR FOR THE FORECAST AREA. FURTHER NORTH THE
POTENT LOW PRESSURE REMAINS WRAPPED UP OVER HUDSON BAY WITH A WEAK
LOBE OF VORTICITY PIVOTING EAST ACROSS NORTHERN WISC AND GENERATING
SOME FLURRIES/LGT SNOW EARLY THIS MORNING. IR IMAGERY SHOWS THE NEXT
MID-LVL WAVE TRYING TO PUSH EAST ACROSS THE CENTRAL PLAINS...HOWEVER
BASED ON SFC OBS MOISTURE CONTINUES TO BE LACKING. CLOUD BASES
REMAIN ABOVE 7KFT AGL FOR MOST POINTS ACROSS THE CENTRAL
PLAINS...DESPITE WHAT SOME GUIDANCE INDICATES SHOULD BE SHOWING
FURTHER MOISTENING AND LOWERING WITH SPOTTY PRECIP DEVELOPING. THIS
WAVE IS POISED TO PUSH EAST AND ARRIVE ACROSS THE FORECAST AREA THIS
MORNING. FORCING REMAINS LACKING IN ADDITION THE ENVIRONMENT IS VERY
DRY...SOUNDINGS CONTINUE TO INDICATE SOME MOISTENING...ALTHOUGH
EXPECT THE ANTI-CYCLONIC FLOW TO KEEP PRECIP LIMITED TO SPRINKLES OR
FLURRIES MAINLY SOUTH OF I-88. LOCAL ARW8KM MODEL SUGGESTS JUST SOME
MID-LVL CLOUDS WITH THIS FEATURE.
EXPECT SKIES TO REMAIN P-CLOUDY TODAY...AND WITH TEMPS ALOFT
HOVERING ARND -4 TO -6 DEG C...SFC TEMPS SHUD BE ABLE TO WARM
GENERALLY INTO THE 30S AND POSSIBLY ARND 40 SOUTH OF PONTIAC TO
KANKAKEE.
TONIGHT...
SFC RIDGE REMAINS OVER THE REGION...AS A MID-LVL TROUGH BEGINS TO
PUSH AN ENHANCED LOBE OF VORTICITY INTO THE UPPER MIDWEST. WITH A
BAROCLINIC ZONE ORIENTED FROM CENTRAL MISSOURI STRETCHING NORTHEAST
THROUGH CENTRAL IL/NORTHERN IN...EXPECT THIS WILL PROVIDE SOME ADDED
LIFT/MOISTURE INTO THIS AREA AND MAY HELP TO SPAWN SOME BETTER
ORGANIZED PRECIP TONIGHT FOR THE SOUTHERN PORTIONS OF THE FORECAST
AREA. AS THE MID-LVL VORT LOBE PUSHES EAST...THIS WILL HELP TO PUSH
THE POPS/MOISTURE FURTHER EAST JUST BEFORE DAYBREAK SUN.
TEMPS WILL RADIATE OVERNIGHT INTO THE TEENS...TO LOW 20S CLOSER TO
WHERE PRECIP/CLOUDS ARE EXPECTED TONIGHT ALONG AND SOUTH OF LASALLE
TO VALPARAISO.
CONFIDENCE...HIGH.
SUNDAY THROUGH MONDAY...
500MB RIDGE OFF THE PAC-NW COAST BEGINS TO SHOW SIGNS OF AMPLIFYING
AS THE DOWNSTREAM MID-LVL TROUGH/VORT STRENGTHENS SUN. THE TROUGH
OVER THE GREAT LAKES REGION BECOMES RELATIVELY FLAT...ALLOWING FOR A
BRIEF SEMI-ZONAL FLOW SUN/MON OVER THE FORECAST AREA.
SFC RIDGING BECOMES ELONGATED STRETCHING FROM CENTRAL CANADA
SOUTHEAST THROUGH THE TENN VALLEY. THIS WILL REMAIN OVER THE REGION
SUN/MON...KEEPING PRECIP CHCS TO A MINIMUM. THE MID-LVL VORT MAX
BEGINS TO DIP SOUTH FROM CENTRAL CANADA MON AFTN...WITH GUIDANCE
PROGGING A SFC WAVE DEVELOPING OVER THE LEE-SIDE OF THE ROCKIES.
THIS FEATURE HAS SLOWED IN ARRIVAL ACROSS THE FORECAST AREA UNTIL
CLOSER TO MON NGT/TUE. HAVE PUSHED POPS BACK UNTIL MON NGT...AS THIS
BOUNDARY BECOMES SLIGHTLY MORE ACTIVE. ALTHOUGH EXPECT ONLY LGT SNOW
WITH ANY ACCUMS REMAINING LESS THAN ONE HALF INCH AT THIS TIME.
TEMPS SUN WILL REMAIN UNSEASONABLY COOL...ALTHOUGH HOW THIS SEASON
HAS GONE IT HAS BECOME THE NORM...WITH TEMPS HOVERING IN THE 20S.
THEN FOR MON TEMPS HOLD IN THE UPR TEENS TO LOW 20S.
CONFIDENCE...HIGH.
TUESDAY THROUGH FRIDAY...
THE PATTERN IN THE EXTENDED PERIODS CONTINUES TO FEATURE A RETURN TO
HIGH AMPLITUDE RIDGING OVER WESTERN CANADA/YUKON...RESULTING IN A
DOWNSTREAM DIGGING TROUGH OVER THE GREAT LAKES REGION. GIVEN HOW
ENSEMBLES HAVE CONTINUED TO DEMONSTRATE MINIMAL SPREAD...CONFIDENCE
REMAINS HIGH THAT A SLUG OF ARCTIC AIR WILL BREAK SOUTH FROM THE
ARCTIC CIRCLE AND SLIDE SOUTH ACROSS CENTRAL CANADA TUE. GUIDANCE
CURRENTLY INDICATES 850MB THERMAL TROUGH OF -20 TO -24 DEG C
ARRIVING OVER THE FORECAST AREA TUE NGT/WED...ACCOMPANIED BY A
ROBUST SFC RIDGE POISED TO PUSH INTO THE CENTRAL PLAINS AND MAINTAIN
A NORTH LLVL FLOW WITH COLD AIR ADVECTING INTO NORTHERN IL/NORTHWEST
IN MID/LATE WEEK. THIS SUGGESTS TEMPS WED WILL STRUGGLE TO WARM
BEYOND THE SINGLE DIGITS...POSSIBLY REACHING THE LOW TEENS. THIS
SHOULD BE SIMILAR FOR THUR.
LATE WEEK THE SFC RIDGE WILL DRIFT SOUTH...ALLOWING LLVL FLOW TO
TURN WEST TO SOUTHWEST AND BRIEFLY ALLOW TEMPS TO WARM BACK INTO THE
TEENS/LOW 20S FRI. HOWEVER ENSEMBLES SUGGEST THIS MAY ONLY BE
TEMPORARY. THE MID-LVL VORT RETROGRADES...WITH A SECONDARY SURGE OF
ARCTIC AIR POISED TO RETURN FOR THE FOLLOWING WEEKEND. AT THIS TIME
MOST OF THE EXTENDED PERIODS WILL REMAIN DRY FROM PERSISTING SFC
RIDGING.
CONFIDENCE IN TEMPS...HIGH.
CONFIDENCE IN DRY WX FOR MOST OF THE EXTENDED...MEDIUM.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CHANCE OF A FEW FLURRIES THROUGH AFTERNOON... ACCUMULATING SNOW
STAYING SOUTH OF THE TERMINALS... THIS AFTERNOON AND EVENING.
* CIGS REMAINING VFR AND VSBYS UNRESTRICTED TODAY-TONIGHT.
* WINDS FROM THE WEST OCCASIONALLY GUSTY THROUGH AFTERNOON.
ED F
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY WITH PRIMARILY VFR
CONDITIONS EXPECTED AND WESTERLY WINDS. A WAVE MOVING EAST ACROSS
IOWA IS PROGGED TO DISSIPATE AS IT MOVES EAST INTO DRY AIR...HOWEVER
SEVERAL MODELS SUGGEST SNOW WILL REDEVELOP THIS AFTERNOON NORTH OF A
WEAK SURFACE WAVE PUSHING ACROSS THE MID MISSISSIPPI VALLEY. MOST
MODELS KEEP PRECIP SOUTH OF THE TERMINALS...THOUGH POSSIBLY CLOSE TO
MDW/GYY...HOWEVER LACK OF UPPER LEVEL SUPPORT AND DRY AIR IN PLACE
ACROSS NORTHERN ILLINOIS WILL MAKE IT DIFFICULT FOR ANY PRECIP TO
REACH THE TERMINALS AND FOR NOW WILL NOT INCLUDE IN TAFS.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM TO HIGH CONFIDENCE THAT ACCUMULATING SNOW WILL STAY SOUTH
OF ORD/MDW.
* HIGH CONFIDENCE IN REMAINING FORECAST ELEMENTS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHC SNOW...ESPECIALLY LATE.
TUESDAY THROUGH FRIDAY...VFR.
BMD
&&
.MARINE...
304 AM CST
EXPECT TO ENTER A PERIOD OF FAIRLY STEADY STATE CONDITIONS ACROSS
LAKE MICHIGAN WITH MODERATE WESTERLY WINDS EXPECTED THIS WEEKEND
THROUGH MIDWEEK. AN ELONGATED RIDGE IS PROGGED TO BUILD AND REMAIN
ANCHORED FROM THE CANADIAN PRAIRIES INTO THE OHIO VALLEY WHILE LOW
PRESSURE FILLS OVER EASTERN CANADA. WINDS WILL CONTINUE TO EASE
BELOW GALE FORCE EARLY THIS MORNING...HOWEVER...EXPECT WINDS TO
REMAIN AT 30 KT THROUGH MUCH OF THE DAY. WINDS WILL FLUCTUATE
SOME...BUT GENERALLY WILL MAINTAIN A WESTERLY COMPONENT WITH GUSTS
BETWEEN 20 TO 30 KT THROUGH WEDNESDAY...THEN BECOMING MORE NW TO N
THURSDAY AS LOW PRESSURE DIVES FROM ONTARIO INTO THE
CENTRAL/EASTERN LAKES REGION.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1036 AM CST Sat Feb 22 2014
.DISCUSSION...
ISSUED 1035 AM CST Sat Feb 22 2014
Extensive band of altocumulus showing up on regional radar
mosaics, from along the Iowa/Missouri border east to near
Danville. Nothing is reaching the ground yet, as there are still
pretty good temperature/dew point spreads in this corridor.
However, main concern will be with increase in isentropic lift
through the afternoon, as frontogenesis takes place across
southern Missouri into southeast Illinois. While the NAM keeps
things dry through the afternoon, the higher resolution models
such as the RAP, HRRR and Hi-Res-NMM show development of light
precipitation in a couple areas, one north of I-74 and the other
from about Danville southwest through Springfield. The GFS has
been significant more robust with this, indicating around 1/3 inch
of precipitation while the other models are more in the order of a
tenth inch or so depending on mesoscale features. Some of the
lower levels on forecast soundings are rather dry, which could
hold off the precip a bit but also cool the column more quickly to
support a changeover to snow. Have increased PoP`s to around
40-50% east of the Illinois River and north of I-70 for this
afternoon and will need to monitor trends closely for
precipitation type.
Geelhart
&&
.AVIATION...
ISSUED 548 AM CST Sat Feb 22 2014
VFR conditions will prevail at all TAF sites at beginning and
through the morning hours. However, a frontal system will drop
into the area and as the forcing along this front increases during
the afternoon, precipitation will begin to develop over the area.
PIA and BMI will should be a little colder so their pcpn will
begin as a mix of rain and snow. SPI/DEC/CMI should see pcpn begin
as rain, given that their temps should be warmer. As the pcpn
begins, the cigs should drop into the MVFR category around
2.5-3KFT. As the front drops further south, the pcpn at PIA and
BMI will change to just all snow, while the pcpn at SPI/DEC/CMI
will change to a mix of rain and snow. Visibilities will decrease
as well, but only looking at around 5sm right now. Cigs will also
decrease little more, but still remain in the MVFR category. The
pcpn should end during the evening hours at PIA and BMI, and after
midnight at SPI/DEC/CMI. When pcpn ends, clouds should scatter out
for the remainder of the night. Winds will be light and variable
as the front moves through, then become northerly to north-
northeast for the remainder of the TAF period. Wind speeds once
the front passes will increase to around 10-12kts.
Auten
&&
.PREV DISCUSSION...
ISSUED 215 AM CST Sat Feb 22 2014
Weak shortwave that pushed across the area late last evening
produced a few sprinkles over parts of central and east central
Illinois. That wave has shifted off to our east early this morning
with skies clearing from northwest to southeast. However, another
disturbance seen on the water vapor loop over the northern Rockies
with clouds on the increase over parts of western Iowa. At the surface,
a frontal boundary stretched from northern Illinois west through west
central Iowa. This feature is expected to push across our area today
into this evening bringing the threat for some light precipitation.
SHORT TERM...Today through Monday
Main forecast concerns this period were with the upstream shortwave
and its affect on the forecast area with respect to timing and
coverage of precip later this morning or early this afternoon, and
then with precip type issues for tonight.
Deep trof that brought the active weather to our area on Thursday
as north of Lake Superior early this morning with a broad cyclonic
flow prevalent at 500 mb over the Great Lakes. Models coming in line
with respect to the shortwave to our northwest this morning and the
placement of the frontal boundary currently to our northwest. The front
should slide southeast into the area today as the upper wave approaches
from the northwest, setting up a period of light overrunning precip
to the north of the boundary, especially for this afternoon into tonight.
Models have trended a bit more aggressive with the 700-500 mb forcing
for this time period and have thrown out a bit more QPF across the area
as well. Not really sure where this is all coming from as the deeper
moisture has been displaced well off to our east and southeast. However,
as the shortwave drops southeast into the mean longwave trof position,
we should see a bit of amplification with the upper system resulting
in better low and mid level forcing, which may be able to squeeze
out a tenth to two tenths of an inch of QPF.
Forecast soundings off the NAM-WRF suggest a rain snow mix possible
in the north, with soundings too warm to support anything but light
rain this afternoon over the central thru east central areas. As the
frontal boundary slides south of our area by this evening, colder air
will be able to work into the lower levels of the atmosphere which
should change any mix over to light snow from northwest to southeast.
May see around an inch of wet snow over parts of east central Illinois
by later tonight with most of the remainder of the area seeing less
than an inch.
The better 700-500 mb QG forcing and precip threat shifts off to our
east by Sunday morning with another Arctic high situated up across
west central Canada bringing in one of several shots of cold air to
the region over the next week. Today will be the last of the "mild"
days as the colder air moves in starting tonight with temperatures
cooling a few degrees each day heading into Monday. By Monday, another
fast moving shortwave in the northwest flow aloft will approach the
area by evening bringing an increasing chance for light snow to mainly
the north half of the forecast area Monday night, followed by a
reinforcing surge of Arctic air into the middle of next week.
LONG TERM...Tuesday through Friday
Most of the medium range models were on board with the idea of a
another negative height anomaly settling south to near James Bay by
the second half of this forecast period. This should keep our
temperatures well below normal through the period with the main
storm track displaced over the southern Plains eastward through the
Gulf states. Our weather will be coming from the northwest thru most
of this period as shortwaves rotate south and southeast around the
large vortex at 500 mb bringing reinforcing shots of cold air and
chances for light snow or flurries. This far out, timing and magnitude
of these fast moving waves embedded in the northwest flow will be
difficult to forecast so will keep the extended dry for now.
Smith
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
423 PM EST SAT FEB 22 2014
.SYNOPSIS...
ISSUED AT 1230 PM EST SAT FEB 22 2014
DRY CONDITIONS WILL PERSIST THROUGH MID AFTERNOON BUT A COLD
FRONT WILL APPROACH THE REGION LATER TODAY WITH ANOTHER CHANCE OF
SNOWFALL OVERNIGHT...ESPECIALLY NEAR AND SOUTH OF HIGHWAY 24.
PRECIPITATION MAY BEGIN BRIEFLY AS LIGHT RAIN LATE THIS AFTERNOON
BEFORE QUICKLY CHANGING OVER TO ALL SNOW EARLY THIS EVENING AS
COOLER AIR FILTERS IN. IT WILL LIKELY REMAIN DRY TONIGHT OVER
EXTREME NORTHERN INDIANA AND SOUTHWEST LOWER MICHIGAN. CANADIAN
HIGH PRESSURE WILL BRING COOL AND DRY CONDITIONS ON SUNDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 421 PM EST SAT FEB 22 2014
MODELS CONTINUE TO SHOW STRONG SIGNAL FOR NARROW...SHORT DURATION
MESOSCALE SNOW THIS EVENING INTO THE OVERNIGHT HOURS. RELIED HEAVILY
ON HIRES GUIDANCE GIVEN SMALL SCALE NATURE TO THIS EVENT. PREVIOUS
SHIFT LOCKED ONTO EVENT AND ADJUSTMENTS MADE BASED ON LATEST
HRRR...RAP13 AND 12Z ARW EAST AND ARW NMM. RESULT IS A LITTLE
NORTHWARD ADJUST TO POPS AND SNOW BUT NOT BY MUCH. THE HIGHWAY 24
CORRIDOR AND SOUTH STILL APPEAR IN LINE FOR A GENERAL 1 TO 3 WITH
SMALL EMBEDDED AREA OF 2 TO 5 WITH ANY MESOBANDING THAT SETS UP.
STRONG MID LEVEL FORCING DEPICTED WITH OMEGA FIELDS IN THE 15 TO 20
UBAR/S RANGE. FGEN FORCING STILL IMPRESSIVE IN THIS SAME AREA WITH
MESOBANDING POTENTIAL SEEN ON VERTICAL CROSS SECTIONS. HIRES
GUIDANCE HAS BEEN PICKING UP ON THIS WITH SOME IMPRESSIVE LIFT AND
QPF AMOUNTS THIS EVENING BETWEEN ONE QUARTER AND ONE HALF INCH NEAR
AND SOUTH OF HIGHWAY 24. INITIAL CONCERNS WITH DRIER LOW LEVEL AIR
AND MOISTURE GOING INTO SATURATION CONTINUE. LITTLE PCPN HAS BEEN NOTED
THROUGH 19Z UPSTREAM WHERE SOME OF THE HIRES GUIDANCE HAS BEEN
SHOWING UP TO A TENTH OF AN INCH LIQUID ALREADY. RADAR MOSAIC HAS
SHOWN MID LEVEL RETURNS BUT FEW IF ANY SURFACE REPORTS. SATELLITE
SHOWS COOLING CLOUD TOPS AND A SHORT WAVE APPROACHING. COUPLED JET
STREAKS EXPECTED OVER AREA BY 00Z AND AS THESE FEATURES COME
TOGETHER EXPECT PCPN TO BEGIN SATURATING AND REACHING GROUND.
HAVE LEANED AWAY FROM THE HIGHER END QPF GIVEN POOR EARLY
PERFORMANCE UPSTREAM AND FOCUSED MORE ON A BLEND OF THE MID RANGE
VALUES. 16Z HRRR DEPICTION OF SNOW DEVELOPING FROM NEAR KLAF TO KFWA
BY 23Z REASONABLE AND SIMILAR TO LATEST RAP13. BRIEF PERIOD OF RAIN
AT ONSET POSSIBLE WITH LOW LEVEL THERMAL FIELDS ABOVE FREEZING.
HOWEVER...EVAPORATIVE COOLING EXPECTED TO QUICKLY COOL VERY SHALLOW
WARM LAYER AND QUICKLY TRANSITION TO ALL SNOW. DISCUSSION WITH WPC
AGREED WITH A GENERAL 1 TO 2 INCHES AND SMALLER AREA OF 2 TO 4
POSSIBLE WITH EXACT LOCATION REMAINING A BIT UNCERTAIN GIVEN SMALL
SCALE BUT INTENSE FORCING. WOULD NOT RULE OUT A FEW 5 INCH REPORTS
BUT WOULD EXPECT THIS TO BE VERY ISOLATED IN A NARROW BAND. TIMING
SUGGEST HEAVIEST SNOW BETWEEN ABOUT 00Z AND 05Z WITH QUICK ENDING
FROM WEST TO EAST. EXPECT A RATHER SHARP GRADIENT ON NORTHERN
PERIPHERY OF SNOW AND THIS WILL LIKELY NEED SOME ADJUSTMENT THIS
EVENING ONCE SNOW DEVELOPS AND TRENDS ASSESSED.
DRIER AND COOLER AIR MOVES IN LATE TONIGHT AND FOR SUNDAY.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 421 PM EST SAT FEB 22 2014
A DOMINANT UPSTREAM RIDGE WILL NOT START TO BREAK DOWN UNTIL LATE
THIS WEEK ALLOWING FOR A VERY COLD UPCOMING PERIOD WITH FLOW COMING
FROM THE CANADIAN INTERIOR. OVERALL...THE GFS AND ECMWF WERE
STRUGGLING WITH RUN TO RUN CONSISTENCY IN HANDLING THE TIMING AND
EXTEND OF SUCCESSIVE SURGES OF ARCTIC AIR...ESPECIALLY LATE THIS
UPCOMING WEEK. HOWEVER...THE CANADIAN GEM AND ITS ENSEMBLES HAVE
KEPT A VERY CONSISTENT SIGNAL FOR THE PAST SEVERAL RUNS HANDLING THE
COLD AIR WITH THE ENSEMBLE MEDIAN STAYING 20 TO 25 DEGREES BELOW
NORMAL FROM TUESDAY THROUGH SUNDAY. FOR THIS PACKAGE...GIVEN THIS
VARIABILITY AMONG THE ECMWF AND GFS...BUT STRONG SIGNAL FROM THE
CANADIAN GEM AND ANALOGS...KEPT TEMPERATURES COLD WITH VIRTUALLY NO
CHANGES FROM THE PREVIOUS FORECAST FOR WEDNESDAY THROUGH THE END OF
THE WEEK. THE ECMWF WAS COLDER AGAIN WITH THE 12Z RUN...WITH 850 MB
TEMPS NEAR -27C SATURDAY. GIVEN THE CLIMATOLOGICAL EXTREMES OF THESE
TEMPERATURES...KEPT HIGHS MAINLY IN THE TEENS WEDNESDAY THROUGH
SATURDAY WITH LOWS IN THE SINGLE DIGITS ABOVE ZERO...TO A LITTLE
BELOW ZERO THURSDAY NIGHT. THESE HIGHS AND LOWS ARE WELL IN LINE
WITH THE LATEST CANADIAN GEM/EPS GRAMS. OTHERWISE...KEPT THE
FORECAST DRY EXCEPT FOR A CHANCE FOR SNOW MONDAY NIGHT WITH THE
ARRIVAL OF A WEAK UPPER LEVEL TROF. THE ECMWF...ALTHOUGH STRUGGLING
LATE IN THE FORECAST PERIOD...HAS A GOOD HANDLE ON A WEAK UPSTREAM
SHORTWAVE THAT SHOULD ARRIVE MONDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1227 PM EST SAT FEB 22 2014
A NARROW BUT INTENSE BAND OF SNOW IS EXPECTED TO DEVELOP THIS
EVENING WITH KFWA SITTING NEAR THE NORTHERN FRINGE OF HEAVIEST
SNOW BAND. KSBN EXPECTED TO REMAIN VFR WITH MID CLOUDS AT TIMES
AND DRY CONDITIONS. SUBTLE WIND SHIFT TO WNW EXPECTED EARLY THIS
EVENING. FURTHER SOUTH...AN INTENSE MESOSCALE BAND OF SNOW IS
BEING DEPICTED TO DEVELOP BY MOST MODELS WITH SOME INTENSE RATES
POSSIBLE FOR A BRIEF PERIOD. THIS BAND ONLY EXPECTED TO BE BETWEEN
50 AND 80 MILES WIDE AND MODELS SHOWING KFWA ANYWHERE FROM CENTER
OF BAND TO JUST ON THE NORTHERN FRINGE. SATELLITE CURRENTLY SHOWS
COOLING CLOUD TOPS UPSTREAM ACROSS NORTHERN MO AND SOUTHERN IL
WHILE RADAR MOSAIC SHOWING MID LEVEL RETURNS DEVELOPING AS FAR
EAST AS WESTERN INDIANA. CONTINUED WITH MVFR VIS AND CIGS IN
LIGHT SNOW AT 23Z AT KFWA BUT ADDED AN IFR COMPONENT GIVEN DECENT
MODEL AGREEMENT ON A PERIOD OF STRONG LIFT ACROSS SOUTHERN ALLEN
COUNTY. LOWER VIS CERTAINLY POSSIBLE FOR A FEW HOURS BUT 00Z TAFS
CAN SHOW THAT BASED ON DEVELOPING RADAR TRENDS AT THAT TIME. PCPN
QUICKLY SHIFTS SOUTH AFTER 05Z WITH DRYING TOWARD DAYBREAK AND VFR
CONDITIONS SUNDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...AGD
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
411 PM EST SAT FEB 22 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 410 PM EST SAT FEB 22 2014
THE LOW THAT BROUGHT THE SNOW AND MIXED PRECIPITATION TO THE AREA
THURSDAY EVENING INTO FRIDAY HAS BECOME STATIONARY NEAR CAPE
HENRIETTA MARIA BETWEEN HUDSON BAY AND JAMES BAY. THIS NEARLY
STATIONARY LOW WILL COMBINE WITH A 1028MB HIGH PRESSURE RIDGE
SLIDING SOUTHEAST FROM A HIGH IN THE CANADIAN ROCKIES AND INTO THE
NORTHERN PLAINS AND MID MISSISSIPPI VALLEY TO CREATE A TIGHT
PRESSURE GRADIENT OVER THE UPPER GREAT LAKES THROUGH TONIGHT AND
PART OF SUNDAY. THUS...THE WINDS AND RESULTING BLOWING SNOW (MAINLY
OVER THE KEWEENAW) WILL BE THE PRIMARY CONCERN FOR TONIGHT INTO
SUNDAY.
WITH THIS TIGHT PRESSURE GRADIENT REMAINING IN PLACE FOR MUCH OF
THE NIGHT AND COLDER AIR ALOFT SPILLING INTO THE REGION...WOULD
EXPECT THE GUSTY CONDITIONS TO REMAIN THROUGH AT LEAST THE FIRST
HALF OF THE NIGHT. EVEN OVER THE LAST COUPLE OF HOURS...WINDS AT
KCMX HAVE FALLEN TO ONLY 35-40MPH. UPSTREAM AT ISLE ROYALE...WINDS
ARE STILL GUSTING TO SIMILAR VALUES AND WITH MODELS SHOWING GUSTS
TO 35KTS THROUGH BETWEEN 06-12Z...WILL FOLLOW THAT IDEA FOR THE
KEWEENAW TONIGHT. SINCE MUCH OF THE SNOW HAS DIMINISHED AT
KCMX...SEEING MORE OF A SPOTTY NATURE TO THE WORST VISIBILITIES ON
WEBCAMS AND THE KCMX OBS. THUS...THINKING THAT THE GOING ENDING
TIME FOR THE BLIZZARD WARNING IS REASONABLE AND THE EVENING SHIFT
WILL BE ABLE TO LET IT EXPIRE. THE QUESTION IS WHETHER A ADVISORY
WILL BE NEEDED TO COVER THE LINGERING BLOWING/DRIFTING SNOW OR IF
IT COULD BE COVERED BY AN SPS. ALMOST LEANING TOWARDS AN SPS...BUT
WILL ALLOW EVENING SHIFT TO SEE HOW VISIBILITIES ARE DOING OVER THE
NEXT FEW HOURS AND THEN DECIDE. WITH THE CLEARING SKIES AND LITTLE
VSBY RESTRICTIONS ON WEBCAMS IN GOGEBIC/ONTONAGON COUNTIES...HAVE
CANCELLED THE EXISTING WINTER WX ADVISORY FOR THERE.
OVER THE REST OF THE AREA...A SHORTWAVE THAT WAS OVER WESTERN
ONTARIO THIS MORNING HAS SHIFTED EAST-SOUTHEAST AND IS MOVING
ACROSS FAR NORTHERN LAKE SUPERIOR. WITH THIS TRACK...IT LOOKS LIKE
THE DEEPER MOISTURE WILL HOLD OFF MOVING SOUTH OVER THE CWA UNTIL
LATE TONIGHT AND ESPECIALLY INTO SUNDAY AFTERNOON. THUS...THINK
MUCH OF THE CLOUDS AND SNOW CHANCES FOR MUCH OF THE SHORT TERM
PERIOD WILL DEPEND ON LAKE EFFECT. WITH RAP ANALYZED 850MB TEMPS
AROUND -17C AND MODELS SHOWING THAT FALLING TO -23C BY 00Z
MONDAY...THERE IS PLENTY OF OVER LAKE INSTABILITY IF WATER IS
PRESENT ON LAKE SUPERIOR. TODAY/S MODIS IMAGE SHOWS SOME OPEN WATER
THAT HAS DEVELOPED OFF THE ARROWHEAD OF MINNESOTA AND ALSO TO THE
EAST OF THE KEWEENAW. THEREFORE...WITH THE WESTERLY 925MB WINDS
EXPECTED TONIGHT...HAVE FOCUSED CLOUD COVER AND SLIGHT TO LOW
CHANCE POPS IN THE AREAS DOWNWIND OF THOSE PATCHES OF OPEN WATER.
THIS MAINLY AFFECTS THE KEWEENAW PENINSULA. WITH WINDS SHIFTING A
LITTLE MORE TO THE NORTHWEST ON SUNDAY AFTERNOON...HAVE SLOWLY
TRANSITIONED POPS TOWARDS THAT DIRECTION. DIDN/T PUT MUCH FOR
SNOWFALL AMOUNTS (ONLY AROUND AN INCH OR SO) INTO THE FORECAST DUE
TO THE STRENGTH OF THE WINDS LIKELY LIMITING FETCH ACROSS THE OPEN
WATER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 410 PM EST SAT FEB 22 2014
NO MAJOR CHANGES EXPECTED TO THE LONG TERM FORECAST WITH MUCH BELOW
NORMAL TEMPERATURES AND OCCASIONAL LIGHT SNOW CLOSE TO LAKE
SUPERIOR. WITH THE ARCTIC AIRMASS ONCE AGAIN BUILDING ACROSS HUDSON
BAY...THE COLDEST TEMPERATURES STILL LOOK TO BE WED-FRI WITH TEMPS
STRUGGLING TO RISE ABOVE ZERO ONCE AGAIN.
AS FOR THE DETAILS...THE DEEP LOW PRESSURE OVER JAMES BAY WILL
CONTINUE TO FILL SUNDAY NIGHT THEN FINALLY MOVE EAST BY MONDAY IN
RESPONSE TO A UPPER SHORT WAVE ROTATING AROUND THE UPPER LOW AND
THROUGH THE REGION. THIS WILL ALLOW PBL WINDS TO VEER TO THE NW
SUNDAY NIGHT. THIS VEERING OF WIND COMBINED WITH WEAK UPWARD MOTION
ASSOCIATED WITH THE UPPER SHORT WAVE AND DEEPER MOISTURE SHOULD
ALLOW FOR SOME LAKE EFFECT SNOW TO SPREAD A LITTLE FURTHER WEST
PERHAPS TO THE ALGER/MARQUETTE COUNTY BORDER. IN ADDITION...LES
SHOULD INCREASE ACROSS THE ENTIRE AREA NEAR LAKE SUPERIOR BUT THIS
IS HIGHLY DEPENDENT ON THE FLUXES OVER THE SEMI-OPEN AREAS OF LAKE
SUPERIOR. ONE WOULD THINK THAT WITH THE WIND OVER THE PAST FEW DAYS
THAT THE ICE ON THE LAKE HAS BROKEN UP SOME. IN FACT...TODAY/S MODIS
IMAGERY INDICATES THAT SEVERAL LARGER BREAKS HAVE OPENED ACROSS THE
WESTERN LAKE AS WELL AS EAST OF THE KEWEENAW. IN FACT...WOULD NOT BE
SHOCKED TO SEE A LITTLE MINI BAND OF ENHANCED LES JUST EAST OF THE
KEWEENAW ORIENTED INTO FAR WESTERN ALGER COUNTY...ESPECIALLY IF WE
CAN SEE ENHANCED LAKE BREEZE CONVERGENCE AS THE WINDS VEER TO NW.
FOR NOW...WILL RAISE POPS TO 50 PCT ACROSS ALL OF ALGER INTO LUCE
COUNTIES AND RAISE POPS TO CHC CATEGORY IN ERN MQT COUNTY. BEHIND
THIS SHORT WAVE...LIGHT LES WILL CONTINUE IN THE KEWEENAW AND INTO
ALGER/LUCE COUNTIES WITH NORTHWESTERLY CYCLONIC FLOW. ONCE
AGAIN...IT IS STILL UNCLEAR IF FLUXES WILL INCREASE ENOUGH TO
GENERATE LES OFF THE LAKE. AS SUCH...WILL CONTINUE WITH JUST CHANCE
POPS. WINDS BACK TO WNW TUE AHEAD OF A WEAK SFC TROUGH...WHICH
SHOULD ALLOW ANY LES TO SHIFT OFFSHORE EXCEPT FOR THE KEWEENAW.
THE EXTENDED PERIOD...WED-SAT...CONTINUES TO LOOK EXTREMELY COLD.
THE 12Z NWP CONTINUES TO BE IN VERY GOOD AGREEMENT IN SHOWING THE
ARCTIC FRONT MOVING THROUGH THE UPPER GREAT LAKES WED NIGHT INTO THU
MORNING...OPENING THE DOOR FOR ARCTIC AIR TO MOVE ACROSS THE REGION.
MODELS STILL SHOW 850MB TEMPS DROPPING TO -30 TO -34C BY THU EVENING
WHICH WILL CAUSE TEMPS TO STRUGGLE TO RISE ABOVE ZERO DURING THE
DAY. SFC HIGH PRESSURE IS FCST TO QUICKLY BUILD ACROSS THE AREA THU
NIGHT WHICH SHOULD ALLOW FOR EXCELLENT RADIATIVE COOLING...THUS
DROPPING SFC TEMPS TO -20F OR LOWER. IF THE SKIES CLEAR AND WINDS GO
LIGHT...THIS COULD BE ONE OF THOSE SITUATIONS SIMILAR TO EARLY MARCH
2003 WHERE NWS MQT SAW A MIN TEMP OF -31F. FOR NOW...WILL GO WITH
LOWS FRIDAY MORNING -20 TO -25 BELOW. PERHAPS SOME MODERATION IN
TEMPS BY SATURDAY WITH SLIGHT 850MB WARMING...BUT THE WINDS WILL
ALSO BE INCREASING AS THE ARCTIC HIGH STRENGTHENS LEADING TO A
TIGHTENING PRES GRADIENT ACROSS THE AREA. AS SUCH...APPARENT TEMPS
WILL NOT FEEL MUCH DIFFERENT INTO THE WEEKEND. JUST TO NOTE...THE
LATEST CFS /CLIMATE FORECAST SYSTEM/ GUIDANCE SHOWS MUCH OF MARCH
WITH BELOW NORMAL TEMPERATURES...
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1246 PM EST SAT FEB 22 2014
A NEARLY STATIONARY LOW PRESSURE SYSTEM NEAR HUDSON BAY AND A HIGH
PRESSURE RIDGE MOVING INTO THE MID MISSISSIPPI VALLEY WILL CONTINUE
TO PRODUCE BREEZY CONDITIONS AT THE THREE TAF SITES THROUGH THE
PERIOD. EXPECT THE STRONGEST GUSTS AT KCMX...TO 35-40KTS...THROUGH
THIS EVENING AND THEN A SLIGHT DECREASE TONIGHT INTO SUNDAY
MORNING. THIS WILL CONTINUE TO PRODUCE EXTENSIVE BLOWING SNOW AND
VISIBILITIES TO A QUARTER MILE. AS THE WINDS
DIMINISH...VISIBILITIES MAY TRY TO COME UP SLIGHTLY...BUT SHOULD
STILL BE IN THE 1/2SM RANGE. WITH THE WESTERLY WINDS AND SOME GAPS
IN THE ICE OVER WESTERN LAKE SUPERIOR...COULD SEE SOME SNOW SHOWERS
AT KCMX TOO THROUGH THE PERIOD...WHICH WILL ASSIST THE LOWER
VISIBILITIES.
FOR KIWD/KSAW...OCCASIONAL MVFR CONDITIONS ARE EXPECTED THIS
AFTERNOON WITH A SCATTERED/BROKEN CU FIELD BUT EXPECT THAT TO
DIMINISH ONCE DIURNAL HEATING IS LOST. THEN THE WESTERLY WINDS
WON/T BE FAVORABLE FOR LAKE EFFECT AND KEPT CLOUDS SCATTERED.
DEEPER MOISTURE WILL ROTATE INTO THE AREA DURING THE DAY TOMORROW
AND COULD PRODUCE A MORE SOLID MVFR CLOUD DECK.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EST SAT FEB 22 2014
A TIGHT PRESSURE GRADIENT BETWEEN A LOW NEAR HUDSON BAY AND A HIGH
PRESSURE RIDGE MOVING INTO THE MID MISSISSIPPI VALLEY WILL CONTINUE
TO PRODUCE WESTERLY GALE FORCE GUSTS TO 35-40KTS TONIGHT. AS THE
LOW WEAKENS ON SUNDAY...THE GRADIENT WILL WEAKEN AND LEAD TO WINDS
DROPPING TO 30KTS. NORTHWESTERLY WINDS WILL CONTINUE SUNDAY NIGHT
INTO THE FIRST HALF OF THE UPCOMING WORK WEEK...WITH GUSTS UP TO
25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BLIZZARD WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST /6 AM CST/ SUNDAY FOR LSZ240>246-
263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...MRD
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1216 PM CST SAT FEB 22 2014
.UPDATE...
ISSUED AT 1216 PM CST SAT FEB 22 2014
ADDED A BIT MORE SKY COVER TO THE NORTHERN HALF OF THE FA AS
CLOUDS LEAK ACROSS THE INTERNATIONAL BORDER TO JUST N OF THE IRON
RANGE. CLOUD COVER HAS FORMED ALONG THE N SHORE AND HAVE ADDED.
MADE SOME OTHER MINOR ADJUSTMENTS.
UPDATE ISSUED AT 930 AM CST SAT FEB 22 2014
ADJUSTED SKY COVER DOWNWARD TO ACCOUNT FOR MORE SUNSHINE THAN
CLOUD COVER ATTM. WILL KEEP AN EYE ON THE CLOUDS N OF THE CANADIAN
BORDER AS SOME ARE JUST S OF THE BORDER. ADDED A MENTION OF
FLURRIES ALONG THE N SHORE WHERE TWM AND BFW HAVE REPORTED
FLURRIES. TIGHT PRESSURE GRADIENT OVER THE FA ATTM WILL KEEP GUSTY
WINDS IN PLAY TODAY.
&&
.SYNOPSIS...
ISSUED AT 339 AM CST SAT FEB 22 2014
SFC/MID LVL LOW NEAR HUDSON BAY HAS A VERY LARGE AND DEEP
CIRCULATION THAT EXTENDS ACROSS ALL OF THE CWA. EXTENSIVE CANOPY OF
CLOUD COVER REMAINS OVER THE REGION ALTHOUGH SLOW CLEARING IS
OCCURRING IN SWRN CORNER OF CWA. OCCASIONAL SNOW SHOWERS HAVE
CONTINUED NEAR THE INTERNATIONAL BORDER..AND JUST EAST OF CWA IN
GOGEBIC COUNTY. LATEST DLH VWP SHOWS 28735KT WINDS NEAR 1.5K FT WHICH
AGREES WITH FCST RAP .5KM AGL. MANY LOCATIONS CONTINUE TO HAVE WELL
MIXED BDRY LYR WITH GUSTY WINDS.
&&
.SHORT TERM...(TODAY THROUGH TOMORROW)
ISSUED AT 339 AM CST SAT FEB 22 2014
LARGE CIRCULATION FROM HUDSON BAY LOW WILL CONTINUE TO AFFECT THE
NORTHLAND THROUGH THE PERIOD. GUSTY WINDS SHOULD PREVAIL AS
DEEPLY STACKED LOW KEEPS A HIGHLY KINEMATIC PATTERN IN PLACE.
STATIONARY NATURE OF MID LVL LOW WILL KEEP A CONSIDERABLE AMOUNT
OF CLOUD COVER OVER NRN AND EASTERN CWA. AMOUNT OF CLEARING IS
LOWER CONFIDENCE ASPECT OF FCST AS ANY SIGNIFICANT CLEARING MAY
ALLOW FOR INSTABILITY CU DEVELOPMENT. SNOW SHOWERS OR FLURRIES ARE
POSSIBLE OVER NRN MN ZONES AND ACROSS NW WISCONSIN SAT AFTN. TEMPS
REMAIN WELL BELOW CLIMO THROUGH THE WEEKEND.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 339 AM CST SAT FEB 22 2014
UNSEASONABLY COLD WEATHER IS EXPECTED TO SETTLE INTO THE NORTHLAND
DURING THE EXTENDED TIME PERIOD...AND REMAIN THERE THROUGHOUT THE
PERIOD. HIGH TEMPERATURES WILL BE SOME 10 TO 20 DEGREES BELOW NORMAL
DURING THE PERIOD...WITH OVERNIGHT LOW TEMPERATURES ON THE ORDER OF
15 TO 25 DEGREES BELOW NORMAL AT TIMES. THIS WILL ENSURE WE CLOSE
OUT THIS MONTH WITH A MAJOR DEPARTURE FROM NORMAL. ON SUNDAY NIGHT
AND MONDAY THERE SHOULD BE A BRIEF WARM UP...BUT IT WILL STILL BELOW
NORMAL. A LOW PRESSURE SYSTEM WILL BRING SOME LIGHT SNOW TO THE
REGION. AT THIS POINT...IT IS POINTING TO AREAS JUST SOUTH OF THE
CWA...BUT THE NEW ECMWF JUST CAME IN WITH SOME LIGHT QPF IN OUR CWA.
MAY NEED TO ADD SOME POPS AT SOME POINT FOR THE CWA. BEHIND THIS
DEPARTING WEAK LOW PRESSURE SYSTEM...A MAJOR ARCTIC AIR MASS WILL
SETTLE INTO THE REGION ON A MAJOR TROUGH SETTING IN OVER THE GREAT
LAKES. IN SUMMARY...TEMPERATURES WILL BE WELL BELOW NORMAL WITH
LITTLE TO NO PRECIPITATION THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1139 AM CST SAT FEB 22 2014
LOW PRESSURE OVER HUDSON BAY WILL CONTINUE TO AFFECT THE NORTHLAND
THROUGH THE NEXT 24 HOURS WITH PERIODS OF CLOUDS AND SNOW SHOWERS
AS WELL AS GUSTY WINDS. THE MINNESOTA ARROWHEAD...KINL/KHIB AND
KDLH...ARE MOST LIKELY TO SEE THE CLOUDS STREAMING DOWN FROM
CANADA AT BKN-OVC020-030. GUSTY WEST TO NORTHWEST WINDS WILL
GRADUALLY DECREASE TO ABOUT 10 KTS AFTER 00Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH -2 11 -9 9 / 10 0 0 10
INL -4 8 -11 6 / 10 20 20 10
BRD -6 12 -11 10 / 0 0 10 10
HYR -5 13 -9 11 / 10 10 20 10
ASX 0 14 -4 12 / 10 10 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SYNOPSIS...CANNON
SHORT TERM...CANNON
LONG TERM...DAP
AVIATION...CLC
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1143 AM CST SAT FEB 22 2014
.UPDATE...
ISSUED AT 930 AM CST SAT FEB 22 2014
ADJUSTED SKY COVER DOWNWARD TO ACCOUNT FOR MORE SUNSHINE THAN
CLOUD COVER ATTM. WILL KEEP AN EYE ON THE CLOUDS N OF THE CANADIAN
BORDER AS SOME ARE JUST S OF THE BORDER. ADDED A MENTION OF
FLURRIES ALONG THE N SHORE WHERE TWM AND BFW HAVE REPORTED
FLURRIES. TIGHT PRESSURE GRADIENT OVER THE FA ATTM WILL KEEP GUSTY
WINDS IN PLAY TODAY.
&&
.SYNOPSIS...
ISSUED AT 339 AM CST SAT FEB 22 2014
SFC/MID LVL LOW NEAR HUDSON BAY HAS A VERY LARGE AND DEEP
CIRCULATION THAT EXTENDS ACROSS ALL OF THE CWA. EXTENSIVE CANOPY OF
CLOUD COVER REMAINS OVER THE REGION ALTHOUGH SLOW CLEARING IS
OCCURRING IN SWRN CORNER OF CWA. OCCASIONAL SNOW SHOWERS HAVE
CONTINUED NEAR THE INTERNATIONAL BORDER..AND JUST EAST OF CWA IN
GOGEBIC COUNTY. LATEST DLH VWP SHOWS 28735KT WINDS NEAR 1.5K FT WHICH
AGREES WITH FCST RAP .5KM AGL. MANY LOCATIONS CONTINUE TO HAVE WELL
MIXED BDRY LYR WITH GUSTY WINDS.
&&
.SHORT TERM...(TODAY THROUGH TOMORROW)
ISSUED AT 339 AM CST SAT FEB 22 2014
LARGE CIRCULATION FROM HUDSON BAY LOW WILL CONTINUE TO AFFECT THE
NORTHLAND THROUGH THE PERIOD. GUSTY WINDS SHOULD PREVAIL AS
DEEPLY STACKED LOW KEEPS A HIGHLY KINEMATIC PATTERN IN PLACE.
STATIONARY NATURE OF MID LVL LOW WILL KEEP A CONSIDERABLE AMOUNT
OF CLOUD COVER OVER NRN AND EASTERN CWA. AMOUNT OF CLEARING IS
LOWER CONFIDENCE ASPECT OF FCST AS ANY SIGNIFICANT CLEARING MAY
ALLOW FOR INSTABILITY CU DEVELOPMENT. SNOW SHOWERS OR FLURRIES ARE
POSSIBLE OVER NRN MN ZONES AND ACROSS NW WISCONSIN SAT AFTN. TEMPS
REMAIN WELL BELOW CLIMO THROUGH THE WEEKEND.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 339 AM CST SAT FEB 22 2014
UNSEASONABLY COLD WEATHER IS EXPECTED TO SETTLE INTO THE NORTHLAND
DURING THE EXTENDED TIME PERIOD...AND REMAIN THERE THROUGHOUT THE
PERIOD. HIGH TEMPERATURES WILL BE SOME 10 TO 20 DEGREES BELOW NORMAL
DURING THE PERIOD...WITH OVERNIGHT LOW TEMPERATURES ON THE ORDER OF
15 TO 25 DEGREES BELOW NORMAL AT TIMES. THIS WILL ENSURE WE CLOSE
OUT THIS MONTH WITH A MAJOR DEPARTURE FROM NORMAL. ON SUNDAY NIGHT
AND MONDAY THERE SHOULD BE A BRIEF WARM UP...BUT IT WILL STILL BELOW
NORMAL. A LOW PRESSURE SYSTEM WILL BRING SOME LIGHT SNOW TO THE
REGION. AT THIS POINT...IT IS POINTING TO AREAS JUST SOUTH OF THE
CWA...BUT THE NEW ECMWF JUST CAME IN WITH SOME LIGHT QPF IN OUR CWA.
MAY NEED TO ADD SOME POPS AT SOME POINT FOR THE CWA. BEHIND THIS
DEPARTING WEAK LOW PRESSURE SYSTEM...A MAJOR ARCTIC AIR MASS WILL
SETTLE INTO THE REGION ON A MAJOR TROUGH SETTING IN OVER THE GREAT
LAKES. IN SUMMARY...TEMPERATURES WILL BE WELL BELOW NORMAL WITH
LITTLE TO NO PRECIPITATION THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1139 AM CST SAT FEB 22 2014
LOW PRESSURE OVER HUDSON BAY WILL CONTINUE TO AFFECT THE NORTHLAND
THROUGH THE NEXT 24 HOURS WITH PERIODS OF CLOUDS AND SNOW SHOWERS
AS WELL AS GUSTY WINDS. THE MINNESOTA ARROWHEAD...KINL/KHIB AND
KDLH...ARE MOST LIKELY TO SEE THE CLOUDS STREAMING DOWN FROM
CANADA AT BKN-OVC020-030. GUSTY WEST TO NORTHWEST WINDS WILL
GRADUALLY DECRESE TO ABOUT 10 KTS AFTER 00Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 12 -2 11 -9 / 10 10 0 0
INL 10 -4 8 -11 / 20 10 20 20
BRD 13 -6 12 -11 / 10 0 0 10
HYR 15 -5 13 -9 / 10 10 10 20
ASX 15 0 14 -4 / 10 10 10 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SYNOPSIS...CANNON
SHORT TERM...CANNON
LONG TERM...DAP
AVIATION...CLC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
407 PM CST SAT FEB 22 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 407 PM CST SAT FEB 22 2014
...ABOVE NORMAL UNCERTAINTY TONIGHT IN A SWATH OF SNOW THAT COULD
END UP DUMPING 6-8 INCHES "IF" THE WORST CASE UNFOLDS...
ALOFT: VERY LOW AMPLITUDE WNW CYCLONIC FLOW WILL REMAIN OVER THE
CNTRL PLAINS THRU SUN. WV IMAGERY SHOWS A SUBTLE SHORTWAVE TROF
OVER BRITISH COLUMBIA. PART OF THIS TROF WILL RACE THRU TONIGHT.
SURFACE: A COLD FRONT MOVED THRU LAST NIGHT AND CURRENTLY
EXTENDED FROM ST. LOUIS-OKLAHOMA CITY-LUBBOCK TX. THIS FRONT WILL
SLOWLY SAG DEEPER INTO TX/AR BY SUNSET SUNDAY.
MEANWHILE...CANADIAN HIGH PRES WILL GRADUALLY BUILD S THRU THE
PLAINS.
REST OF THIS AFTERNOON: INCREASING CLOUDS OVER S-CNTRL NEB WILL
OBSCURE THE SUN WHILE N-CNTRL KS SHOULD SEE A NICE END TO THE DAY.
HIGH TEMPS WILL OCCUR 4-5 PM.
TONIGHT: BECOMING CLOUDY WITH A BAND OF SNOW DEVELOPING ACROSS
THE FCST AREA AND IT COULD BECOME HEAVY IN A VERY NARROW SWATH
OVER S-CNTRL NEB. PROBABILITIES OF NO SNOW AT ALL ARE HIGHEST OVER
N-CNTRL KS.
THIS WILL BE A JET STREAK DRIVEN EVENT AS WIND/MASS ADJUSTMENTS
RESULT IN WARM AIR ADVECTION AND FRONTOGENESIS /FGEN/ ON THE
FRONT THAT MOVED THRU LAST NIGHT. CROSS SECTIONS INDICATE MID-
LEVEL UPRIGHT INSTABILITY AND LIFT WILL BE STRONG IN THE DENDRITIC
GROWTH ZONE /DGZ/.
SEVERAL SCENARIOS ARE POSSIBLE TONIGHT AND WE WILL REALLY NOT KNOW
WHICH ONE IS RIGHT UNTIL WE SEE THIS UNFOLD. THIS FCST IS FRAUGHT
WITH UNCERTAINTY AND WE ARE ADMITTEDLY CONSERVATIVE ON SNOW
AMOUNTS AND THE AERIAL EXTENT OF THE ADVISORY. BE PREPARED FOR
ADJUSTMENTS LATER THIS EVENING AND TONIGHT THAT COULD RESULT IN
DRAMATICALLY INCREASING OR DECREASING AMOUNTS FOR YOUR AREA.
09Z AND 15Z SREF PROBABILITIES FOR .25" ARE HIGHEST IN THE
ADVISORY AREA. THE 15Z PROBS FOR .25" ARE HIGHER THAN 09Z AND THE
70% CHANCE OF .25" NOW EXTENDS E TO GRI. THE 19Z RAP SUPPORTS
THIS. A CHECK OF THE 18Z NAM HAS .25" TO HASTINGS.
SNOW TOTALS: GENERALLY 1-3" OVER S-CNTRL NEB. 2-3" FROM THE
TRI-CITIES WESTWARD...AND 3-4" PRIMARILY OVER DAWSON COUNTY. THIS
IS OUR BEST STAB USING A BLEND THE 00Z/06Z/12Z MULTI-MODEL QPF.
THAT PRESENTS A PROBLEM. TOO MUCH AVERAGING SHOULD HIT THE SWATH
OF SNOW CORRECTLY...BUT IT MAY BE TOO BROAD COMPARED TO REALITY
AND FCST AMOUNTS MAY NOT BE HIGH ENOUGH.
SNOW-LIQUID RATIOS: USED PRIMARILY 15:1 THRU THE EVENING AND
CLOSE TO 20:1 AFTER MIDNIGHT. GIVEN THE STRENGTH OF THE LIFT IN
THE DGZ... THESE RATIOS COULD ALSO BE CONSERVATIVE.
POSSIBLE WEAKNESSES IN TONIGHT/S FCST:
1) WE MAY BE TOO BROAD WITH THE EDGES OF THE SNOW BAND...I.E. IT
MAY BE MORE NARROW THAN DEPICTED.
2) DO WE HAVE THE HIGHEST POPS IN THE RIGHT LOCATION? THE HI-RES
GEM HAS THE BAND BETWEEN I-80 AND THE KS BORDER. WE ARE IN THE
I-80 CORRIDOR.
3) DEWPOINTS MAY BE TOO HIGH N OF I-80. DEWPOINTS IN THE SINGLE
DIGITS ARE AS CLOSE AS O`NEILL. ADVECTION OF THIS VERY DRY AIR
WILL PLAY A ROLE IN LIMITING THE NRN EXTENT OF THE BAND.
4) ARE AMOUNTS HIGH ENOUGH? WOULD NOT BE SURPRISED TO SEE A
NARROW STRIP OF WARNING LEVEL SNOW /6-8"/ SOMEWHERE GIVEN THE
RATIOS WE ARE LIKELY TO SEE.
UNCERTAINTY: PLEASE KEEP IN MIND THAT THERE ARE SOME AREAS THAT
HAVE SNOW IN THE FCST...BUT WILL SEE NO SNOW AT ALL. THIS
ESPECIALLY APPLIES IF THE FCST PROBABILITY OF SNOW AT YOUR
LOCATION IS 40% OR BELOW. THERE WILL BE A SHARP CUT-OFF ON THE NRN
AND SRN FRINGES OF THIS BAND. THE SMALL SCALE NATURE OF THIS BAND
IS PROBLEMATIC FOR PINNING DOWN DETAILS...BUT THIS COULD END UP A
WARNING LEVEL EVENT FOR SOME COUNTIES.
LOW TEMPS WERE FROM CONSENSUS OF 2M TEMPS WHICH RAISED TEMPS
SEVERAL DEGREES.
SUN: FGEN LIFTS N AND MID-LEVELS DRY OUT WITH STABILITY RETURNING.
PATCHES OF LIGHT SNOW WILL LINGER THRU MID-MORNING...BUT THE
ACCUMULATING SNOW WILL ESSENTIALLY BE OVER. PLENTY OF CLOUDS WILL
REMAIN AND A FEW FLURRIES COULD REDEVELOP N AND W OF THE TRI-
CITIES IN THE AFTERNOON.
HIGH TEMPS HAVE A LOT OF CONTINUITY WITH THE 4 AM GID FCST. THE
ONLY CHANGE WAS TO NUDGE TEMPS DOWN E OF HWY 281.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 407 PM CST SAT FEB 22 2014
THE BIG STORY WILL BE THE WELL BELOW NORMAL TEMPERATURES ALONG
WITH SEVERAL CHANCES OF WINTRY PRECIPITATION. HIGH TEMPERATURES
THROUGH THE PERIOD WILL GENERALLY AVERAGE 10 TO 15 DEGREES BELOW
NORMAL.
SUNDAY NIGHT AND MONDAY...MID LEVEL ISENTROPIC LIFT WILL RESULT
IN SOME LOW END LIGHT SNOW CHANCES PRIMARILY ACROSS OUR NORTHERN
ZONES WITH THE BETTER SNOW CHANCES WELL NORTH OF OUR FORECAST AREA
ACROSS SOUTH DAKOTA. ALTHOUGH NOT IN THE OFFICIAL FORECAST AS OF
RIGHT NOW...WILL ALSO NEED TO WATCH OUT FOR THE POSSIBILITY OF
LIGHT FREEZING DRIZZLE ACROSS OUR NORTHERN AND WESTERN ZONES LATE
SUNDAY NIGHT INTO EARLY MONDAY MORNING. ANY FREEZING DRIZZLE WOULD
PRIMARILY BE CONFINED TO OUR WESTERN AND NORTHERN ZONES. THE 12Z
GFS AND ECMWF DO NOT REALLY SHOW MUCH IN THE WAY OF FREEZING
DRIZZLE POTENTIAL...BUT THE 12Z AND 18Z NAM DO INDICATE SOME
POTENTIAL WITH LOW LEVEL SATURATION BENEATH A DRY MID LEVEL. THE
NAM IS STILL A BIT OF AN OUTLIER AND THE POTENTIAL EVEN IN THE NAM
IS SO MARGINAL THAT WE WILL CONTINUE TO LEAVE FREEZING DRIZZLE OUT
OF THE FORECAST FOR NOW. ANY SNOW AMOUNTS WOULD LIKELY BE VERY
LIGHT AND LESS THAN ONE HALF INCH.
MONDAY NIGHT THROUGH TUESDAY...A SHORTWAVE TROUGH WILL TRACK
SOUTHEAST OUT OF CANADA. ASSOCIATED UPPER JET DYNAMICS AND A
PROGRESSIVE BAND OF MID LEVEL FRONTOGENESIS WILL LEAD TO
ADDITIONAL CHANCES FOR LIGHT SNOW. NOT EXPECTING MUCH SNOW AT
THIS TIME WITH MOST PLACES SEEING FLURRIES UP TO 1 INCH. COLDER
AIR WILL FILTER IN ON TUESDAY WITH HIGHS STUCK IN THE 20S FOR MOST
AREAS.
WEDNESDAY THROUGH SATURDAY...WILL TRANSITION FROM A NORTHWESTERLY
FLOW PATTERN TO A MORE ZONAL PATTERN...WITH PERHAPS EVEN THE
DEVELOPMENT OF A TROUGH OVER THE WESTERN CONUS LATE IN THE PERIOD.
OVERALL...THIS IS MORE LIKELY BE A DRY AND COOL PERIOD FOR OUR
FORECAST AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1156 AM CST SAT FEB 22 2014
THIS AFTERNOON: VFR WITH SLOWLY INVADING MULTI-LAYERED CLOUDS
ABOVE 10K FT. NE WINDS 10-15 KTS. CONFIDENCE: HIGH
TONIGHT: CIGS LOWER STEADILY WITH MVFR CIGS ARRIVING 02Z-04Z AND
SHOULD QUICKLY LOWER TO IFR/LIFR 04Z-06Z AS SNOW OVERSPREADS.
THERE IS UNCERTAINTY IN THE LOCATION AND TIMING OF WHAT COULD BE A
FAIRLY NARROW BAND OF SNOW. NE WINDS AROUND 10 KTS.
CONFIDENCE: MEDIUM
SUN MORNING: VSBYS SHOULD IMPROVE TO MVFR BY 13Z AS THE SNOW
LIGHTENS UP OR ENDS ALTOGETHER. CIGS REMAIN UNCERTAIN AND FCST
GUIDANCE IS OF MINIMAL HELP. SO HAVE INDICATED SOME GRADUAL
UPWARD STEPS...IMPROVING TO MVFR. N WINDS AROUND 10 KTS.
CONFIDENCE: LOW
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR NEZ060-061-072.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1136 AM CST SAT FEB 22 2014
.UPDATE...
ISSUED AT 653 AM CST SAT FEB 22 2014
ANALYSIS OF WATER VAPOR IN CONJUNCTION WITH THE NAM...SREF...UKMET
AND ARF/NMM SOLNS SUGGESTS THE POTENTIAL FOR A COUPLED 500 MB JET
DEVELOPING NEAR OR ACROSS SWRN NEB THIS EVENING. THESE MODELS ARE
THE HEAVY HITTERS WITH QPF ACROSS THE FCST AREA. THE SPEED MAX IS
CURRENTLY ALONG THE COAST OF BRITISH COLUMBIA AND MOVING RAPIDLY
SOUTH AS FCST BY THE NAM. TIMING TOOLS SUGGEST IS COULD REACH ERN
WY BY 18Z WHICH IS MUCH FASTER THAN ANY MODEL SHOWS.
NONETHELESS...IF THIS JET MAX CAN MAINTAIN ITS 75 KT INTENSITY AND
COUPLE WITH THE DEPARTING MIDWEST JET THIS EVENING...HEAVY SNOW
WOULD DEVELOP AS INDICATED BY THE NAM. ITS UNCERTAIN WHY THE
GFS AND ECM DONT SHOW THIS DEVELOPMENT BUT DEPENDING ON THE
LOCATION OF THE COUPLE...NERN COLO/SERN WY/SRN NEB PANHANDLE VS
SWRN NEB...THE POTENTIAL FOR HEAVY SNOW REMAINS UNDER EVALUATION.
THERE ARE NO CHANGES TO THE FCST ATTM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CST SAT FEB 22 2014
THE MODELS...ESPECIALLY THE NAM...ARE ADVERTISING A
FRONTOGENETICALLY FORCED SNOW EVENT LATER TODAY THROUGH SUNDAY
MORNING. THE NAM IS THE STRONGEST WITH THE FRONTOGENESIS AND
RESULTING LIFT. THE LOCATION OF THE SNOW BAND SHOWN BY THE MODELS
APPEARS TO BE TRENDING SOUTH IN THE ECM...GFS...06Z NAM AND GEM
REG FAVORING SWRN NEB SOUTH OF INTERSTATE 80 WHILE THE 03Z
SREF...00Z NAM AND GEMNH MODELS PREFER INTERSTATE 80 AND THEN UP
THE NORTH PLATTE VALLEY. THIS IS A DIFFERENCE OF ABOUT 50 MILES
WHICH IS NORMAL. A BLEND OF THE 06Z NAM AND THE OTHER MODELS
PRODUCED 3 TO 5 INCHES OF SNOW BLENDED ACROSS THE AFOREMENTIONED
AREAS WITH HIGHEST AMOUNTS JUST SOUTH OF INTERSTATE 80 IN LINCOLN
COUNTY.
THE COBB SNOW TO LIQUID METHODOLOGY USING THE NAM AND GFS IN THE
800-600 MB LAYER PRODUCED A 19 TO 1 RATIO IN THE 00Z RUNS BUT THE
06Z NAM CAME IN AROUND 17 TO 1. SINCE 19 TO 1 IS VERY HIGH...17 TO
1 WAS USED WHICH IS CLOSER CLIMATOLOGY.
THE NAM VISIBILITY PRODUCT SUGGESTS VISIBILITY FALLING TO 1/2
MILE AT TIMES. MEANWHILE FOLDED THETA E AND DEEP LIFT IN A
SATURATED DENDRITIC LAYER SUGGESTS A PERIOD OF INCH AN HOUR
ACCUMULATION. A WINTER WEATHER ADVISORY IS IN PLACE FOR THIS
EVENT WHERE 3 INCHES OR MORE SNOW IS FORECAST.
OTHERWISE...THE MAINSTREAM MODELS HAVE NOT CAPTURED THE RESIDENT
SFC MOISTURE THIS MORNING WHICH MAY BE THE REASON SOME SOLNS LIKE
THE ECM ARE VERY DRY. A BLEND OF THE HRRR AND RAP WAS USED FOR
DEW POINTS TODAY AND THE 08Z RAP SHOWS PCPN FILLING IN ACROSS
SWRN NEB THIS EVENING LIKE THE 06Z NAM SHOWED. A WEAK ARCTIC
FRONT...CURRENTLY NEAR KHON...WILL MOVE PART WAY INTO THE FCST
AREA TODAY INDUCING UPSLOPE FLOW AND THIS SHOULD POOL LOW LEVEL
MOISTURE ACROSS SWRN NEB.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 351 AM CST SAT FEB 22 2014
ONGOING SNOW ACROSS SOUTHWEST NEBRASKA WILL BE DIMINISHING SUNDAY
MORNING AS THE NORTHWEST FLOW CONTINUES TO PUSH THE DISTURBANCE
TO THE SOUTHEAST. HOWEVER A SECOND DISTURBANCE WILL BE QUICK TO
MOVE TOWARDS THE CWA BY SUNDAY AFTERNOON. THIS NEXT WAVE MODELS
HAVE DECENT AGREEMENT WITH A MORE NORTHERN TRACK...COMPARED TO
THE FIRST WAVE. BY SUNDAY AFTERNOON SNOW WILL BE ON THE INCREASE
ACROSS NW NEB WHICH WILL PROGRESS EAST...ACROSS NORTH
CENTRAL...SUNDAY NIGHT BEFORE DIMINISHING ON MONDAY. MODELS SHOW
BEST LIFT NEAR THE NEB/S DAKOTA BORDER SUNDAY NIGHT...AHEAD OF A
140 PLUS KT JET STREAK AT 300 MB. PWATS INCREASE TO GREATER THAN
0.3 INCHES...WITH A FGEN BAND TO RESULT IN DECENT WINDOW FOR SNOW
PRODUCTION...WITH AROUND A 17:1 RATIO. SNOW TOTALS OF 2 TO 3
INCHES LOOK LIKELY...HOWEVER WILL NEED TO MONITOR AS IT WOULD NOT
TAKE MUCH TO INCREASE THIS TO 4 OR 5 INCHES WHICH WOULD RESULT IN
THE NEED FOR AN ADVISORY.
BY MONDAY NIGHT INTO TUESDAY YET ANOTHER DISTURBANCE WILL BE
CROSSING THE HIGH PLAINS. THIS TIME MODELS FAVOR A SOUTHERN
TRACK...BACK OVER THE SOUTHERN PANHANDLE INTO SW NEB. POPS ONLY
IN THE LOW CHANCE CATEGORY AS MODEL SPREAD HAS INCREASED...ALONG
WITH AVAILABLE MOISTURE. COLD DRIER AIR...WITH ARCTIC HIGH
PRESSURE DRIFTING SOUTH ACROSS THE NORTHERN PLAINS. THIS HAS THE
POTENTIAL TO EITHER PUSH THE SNOW FURTHER SOUTH...OR BRING DRIER
AIR WHICH WILL RESULT IN LESS SNOW REACHING THE GROUND. STAY
TUNED TO AS CHANGES TO AMOUNTS ARE EXPECTED.
TEMPERATURES TO START OFF THE WEEK WILL BE BELOW NORMAL AS
SNOW/CLOUDS KEEP TEMPS FROM SEEING MUCH OF A DIURNAL SWING. HIGHS
GENERALLY SHOULD HOLD IN THE 20S TO MID 30S. SW NEB MAY PUSH
CLOSE TO 40 ON MONDAY WITH A LITTLE MORE SUN INBETWEEN SYSTEMS.
BY TUESDAY NIGHT THE ARCTIC HIGH PRESSURE WILL BUILD OVERHEAD.
LOWS AS SKIES CLEAR IN THE SINGLE DIGITS...ALTHOUGH WITH A SNOW
PACK TEMPS COULD DIP BELOW ZERO. RECORDS ARE STILL IN THE DOUBLE
DIGIT BELOW ZERO...SO LOWS IN THE SINGLE DIGITS BELOW ZERO ARE
STILL EASY TO HIT...ESPECIALLY IF SKIES CLEAR EARLY IN THE NIGHT
WITH A FRESH SNOW COVER.
ARCTIC HIGH SLIDES EAST BY WED...MEANWHILE MODELS TRY TO BUILD
THE WESTERN RIDGE SLOWLY TO THE EAST. STILL LOOKING MAINLY DRY
WITH THE STORM TRACK OVER THE GREAT LAKES. HIGHS BELOW NORMAL AS
WE GO THROUGH MID TO LATE WEEK...ALTHOUGH LESS CONFIDENCE IN
TEMPS BY THE END OF THE WEEK. LATEST MEX GUIDANCE IS WARMER IN
THE EXTENDED...HOWEVER THE ECMWF GUIDANCE RECYCLES A SECOND HIGH
PRESSURE AND COLD AIR ACROSS THE HIGH PLAINS. EXAMPLE OF RANGE
INCLUDE FRIDAY MAX T GUIDANCE OF EITHER 42 FROM THE MEX OR 21
FROM THE EC FOR KLBF. EVEN THE ENSEMBLE RANGE FROM BOTH MODELS IS
HIGH...WITH HIGHS RANGING FROM THE 40S TO THE TEENS. FORECAST
UNCHANGED FROM THE ALLBLEND AND WILL WAIT TO SEE WHICH SIDE OF
THE AISLE WE END UP...ALTHOUGH THIS TYPE OF PATTERN CAN BE
FAVORABLE OF A LARGE SPREAD ACROSS THE CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1135 AM CST SAT FEB 22 2014
MAIN CONCERN IN THE CURRENT TAF PERIOD IS SNOW AND POTENTIAL LIFR
CONDITIONS AT KLBF. LOW LEVEL CIGS WILL CONTINUE TO SPREAD EAST
ACROSS WESTERN NEBRASKA THROUGH THE AFTERNOON. KVTN ALREADY INTO
MVFR AND EXPECTING MVFR AT KLBF AROUND 22Z.
SNOWFALL STARTS TO MOVE INTO WESTERN AND SOUTHWEST NEBRASKA THIS
AFTERNOON AND EVENING. HEAVIEST SNOWFALL IS EXPECTED DURING THE
OVERNIGHT WHICH MAY BRING KLBF INTO LIFR CATEGORY. SNOWFALL ACROSS
NORTHERN NEBRASKA AND KVTN EXPECTED TO BE DELAYED AND NOT AS
INTENSE.
WINTRY WEATHER WILL STICK AROUND INTO SUNDAY MORNING AND SLOWLY
BEGIN TO TAPER OFF.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 PM CST /5 PM MST/ THIS EVENING TO
NOON CST /11 AM MST/ SUNDAY FOR NEZ022-023-035-036-056>059-070-
071.
&&
$$
UPDATE...CDC
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 AM CST SAT FEB 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 232 AM CST SAT FEB 22 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED NORTHWEST FLOW FROM EASTERN ALASKA INTO THE CENTRAL PLAINS...
AND THURSDAYS WINTER STORM AS A LARGE UPPER LOW OVER FAR NORTHERN
ONTARIO. THE FORECAST AREA CONTINUES TO BE INFLUENCED BY THE
CIRCULATION AROUND THE LARGE UPPER LOW WITH A SERIES OF WEAK
SHORTWAVES ROTATING AROUND IT MOVING THROUGH THE FORECAST AREA.
PLENTY OF DRY AIR SEEN ON THE 00Z MPX SOUNDING HAS KEPT THESE
SHORTWAVES FROM PRODUCING ANYTHING. IN FACT...OUTSIDE OF SOME LOW
STRATUS NORTH OF HIGHWAY 10 IN WISCONSIN...SKIES ARE MOSTLY CLEAR.
LOW TO MID LEVEL NORTHWEST WINDS AROUND THE LOWS CIRCULATION
CONTINUE TO DRAW COLDER AIR SOUTH OUT OF CENTRAL CANADA INTO THE
FORECAST AREA. 850MB TEMPS AT MPX DROPPED FROM -4C AT 00Z FRIDAY
TO -13C AT 00Z SATURDAY. WELL OFF TO THE NORTHWEST...THERE ARE TWO
IMPORTANT SHORTWAVES OF NOTE WHICH INFLUENCE MONDAYS FORECAST...ONE
OVER NORTHERN ALBERTA AND A SECOND IN THE YUKON.
VERY LITTLE CHANGE IN THE UPPER LEVEL PATTERN IS PROGGED OVER THE
NEXT 24 HOURS. THIS MEANS THE FORECAST AREA WILL CONTINUE TO BE
INFLUENCED BY THE CIRCULATION AROUND THE UPPER AND SURFACE LOWS IN
FAR NORTHERN ONTARIO...ALLOWING A FEED OF DRY...COLD AIR ON
NORTHWEST WINDS TO CONTINUE. MAY HAVE TO KEEP A WATCH FOR SOME
FLURRIES THIS MORNING ACROSS NORTHEAST IOWA AND FAR SOUTHWEST
WI...ASSOCIATED WITH A SHORTWAVE TRACKING FROM SOUTH DAKOTA INTO
NORTHERN ILLINOIS. CURRENTLY THINK THE DRY AIR WILL WIN OUT AND ANY
MEANINGFUL SNOW/FLURRIES WILL STAY TO THE SOUTH.
925MB TEMP PROGS SUGGEST THAT THE HIGHER SUN ANGLE HERE IN LATE
FEBRUARY WILL HELP TO MODIFY SOME OF THE COLD AIR DURING THE DAYTIME
HOURS. STILL...READINGS AT 18Z OF -12 TO -14C AND FRESH SNOW ONLY
SUPPORT HIGHS IN THE MID TEENS TO MID 20S. 925MB WINDS STAYING UP
TONIGHT...ON THE ORDER OF 30 TO 35 KT...WILL HELP KEEP SURFACE WINDS
FROM DECOUPLING. HOWEVER...THESE WINDS DROP TEMPS TO -14 TO -18C BY
12Z SUNDAY. THIS COLDER AIR WILL EASILY ALLOW FOR LOWS IN THE SINGLE
DIGITS ABOVE ZERO...AND EVEN IN THE SINGLE DIGITS BELOW ZERO IN THE
TYPICAL COLD SPOTS. WIND CHILLS COULD GET CLOSE ENOUGH TO WARRANT A
WIND CHILL ADVISORY OVER TAYLOR/CLARK COUNTIES LATE TONIGHT INTO
SUNDAY MORNING. GIVEN WIND CHILLS CURRENTLY FORECAST IN THE 18 TO 23
BELOW ZERO RANGE FOR THAT AREA...WILL LET LATER SHIFTS TO DECIDE ON
THE ADVISORY.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 232 AM CST SAT FEB 22 2014
THE RETURN OF ARCTIC AIR REMAINS THE BIG IMPACT ITEM IN THE LONG
TERM...WITH A BRIEF BOUT OF SNOW POSSIBLE MONDAY INTO MONDAY NIGHT.
MODELS CONTINUE TO ADVERTISE THE CURRENT RIDGE OVER THE EASTERN
PACIFIC INTO ALASKA WILL DEVELOP INTO AN OMEGA BLOCK OVER THE NEXT
FEW DAYS...WITH ONLY A SLIGHT MOVEMENT EASTWARD. THIS OMEGA BLOCK
ALLOWS SHORTWAVES OVER THE ARCTIC TO DIVE SOUTH INTO THE NORTHERN
U.S....BRINGING THE ARCTIC AIR WITH THEM. ITS WORTH NOTING THAT
HIGHS OBSERVED ON FRIDAY ACROSS THE NORTHWEST TERRITORIES AND
NUNAVUT REGION WERE IN THE TEENS AND 20S BELOW ZERO. HEADING INTO
LATE NEXT WEEK AND NEXT WEEKEND...A CONSISTENT SIGNAL EXISTS THAT
THE SOUTHERN END OF THE OMEGA BLOCK WILL BREAK DOWN. FOR NOW IT
APPEARS WE WILL STAY INFLUENCED BY TROUGHING AND ARCTIC AIR ACROSS
SOUTHERN CANADA.
THE MAJORITY OF THE SHORTWAVES DROPPING OUT OF THE ARCTIC ARE
SUGGESTED TO HAVE LITTLE IF ANY MOISTURE WITH THEM. THUS...THERE IS
NOT A LOT OF PRECIPITATION FORECAST IN THE LONG TERM. THE LONE
EXCEPTION TO THIS IS ON MONDAY...WHEN THE SHORTWAVES OVER NORTHERN
ALBERTA AND THE YUKON ARE PROGGED TO COME ACROSS THE FORECAST AREA
AS A PHASED SHORTWAVE TROUGH. PRECIPITABLE WATER VALUES ACCORDING
TO THE 22.00Z GFS ARE SUGGESTED TO CLIMB TO 0.20 INCHES...WHICH
COMBINED WITH THE POTENT LOOK OF THE SHORTWAVES SHOULD SQUEEZE OUT
SOME SNOW. THE 22.00Z NAM WAS THE DRIEST OF GUIDANCE...BUT THE WORRY
POSED BY THE MODEL SUGGESTING A DRY SCENARIO KEPT CHANCES FROM GOING
MUCH ABOVE 50. IF IT COMES AROUND TOWARDS A WETTER SCENARIO...
CHANCES CAN BE RAISED. TIMING WISE...MODELS HAVE SLOWED THE
PROGRESSION OF THE SNOW. CONSENSUS SEEMS TO FAVOR SNOW MOVING INTO
LOCATIONS WEST OF THE MISSISSIPPI RIVER DURING THE AFTERNOON...THEN
MARCHING EAST ACROSS THE REST OF THE AREA DURING THE EVENING. AFTER
06Z TUESDAY...MUCH OF THE SNOW LOOKS TO BE OVERWITH. LACK OF
MOISTURE WILL KEEP SNOW AMOUNTS DOWN...BUT WITH SNOW TO WATER RATIOS
NEAR 20 TO 1 SHOULD HELP IN ACCUMULATING ANYWHERE FROM 0.5 TO 2
INCHES OF SNOWFALL.
NOW REGARDING THE COLD. SUNDAY AND MONDAY LOOK PRETTY SIMILAR TO
TODAY WITH REGARDS TO HIGHS...WITH JUST A SLIGHT COOLING EACH DAY AS
COLDER AIR FILTERS IN. A MORE SIGNIFICANT PUSH OF ARCTIC AIR COMES
INTO THE FORECAST AREA TUESDAY INTO TUESDAY NIGHT. IN FACT...925MB
TEMPS FALL FROM -14 TO -18C AT 12Z TUESDAY TO -22 TO -25C BY 12Z
WEDNESDAY. THESE REMAIN PRETTY CONSISTENT...AND IT COMES WITH A
20-40 KT 925MB WIND TOO...SUGGESTING A WIND CHILL ADVISORY IS HIGHLY
LIKELY. A PERIOD OF WARM ADVECTION REMAINS ON TAP TO COME IN ON
WEDNESDAY...THOUGH COUNTER-ACTED FROM A WIND CHILL PERSPECTIVE
BECAUSE OF A BRISK WEST WIND. BEYOND WEDNESDAY...THERE REMAINS SIGNS
OF ANOTHER SIGNIFICANT COLD SHOT LIKE THE ONE TUESDAY NIGHT...BUT
WHEN IS NOW A QUESTION MARK. THE 22.00Z GFS SHOWS THE SHOT COMING IN
ON THURSDAY...SIMILAR TO PAST ECMWF RUNS. HOWEVER...THE 22.00Z ECMWF
NOW SUGGESTS THAT COLD SHOT IS DELAYED UNTIL FRIDAY MORNING. THE BAD
PART ABOUT THE ECMWF IS THAT THE COLD SHOT IS EVEN COLDER TOWARDS
SATURDAY MORNING. FOR NOW STAYED WITH A CONSENSUS FORECAST ON
TEMPERATURES WEDNESDAY NIGHT THROUGH FRIDAY NIGHT. WHICHEVER
SOLUTION PANS OUT...MORE WIND CHILL ADVISORIES ARE LIKELY.
ON A CLIMATE NOTE...BASED ON CURRENT TEMPERATURE FORECASTS...
LA CROSSE WILL END UP 3RD OR 4TH COLDEST FOR THE MONTH OF FEBRUARY.
&&
.CLIMATE...COLD FEBRUARY AND WINTER SEASON
ISSUED AT 526 AM CST SAT FEB 22 2014
UPON A MORE DETAILED LOOK AT THE CURRENT TEMPERATURE FORECASTS THRU
THE END OF THE MONTH...LA CROSSE WOULD END WITH WITH A FEB AVERAGE
TEMPERATURE OF 9.4 DEGREES. THIS WOULD TIE WITH 1899 FOR THIRD
COLDEST FEB OF RECORD...BEHIND ONLY FEB OF 1873 AND 1936. THE WINTER
SEASON /DEC-FEB/ WOULD END UP WITH AN AVERAGE TEMPERATURE OF 11.5
DEGREES...FIFTH COLDEST WINTER OF RECORD.
FOR ROCHESTER...FEB WOULD END UP WITH AN AVERAGE TEMPERATURE OF 7.2
DEGREES...FOURTH COLDEST OF RECORD...BEHIND FEB OF 1917...1936 AND
1979. THE WINTER SEASON /DEC-FEB/ WOULD END UP WITH AN AVERAGE
TEMPERATURE OF 9.0 DEGREES...TIED FOR FIFTH COLDEST WINTER OF RECORD.
THIS WOULD BE THE COLDEST WINTER IN 35 YEARS. ONE WOULD HAVE TO GO
BACK TO THE WINTERS OF 1976-1977...1977-1978 AND 1978-1979 TO FIND A
COMPARABLY COLD WINTER AT BOTH ROCHESTER AND LA CROSSE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1100 AM CST SAT FEB 22 2014
HIGH PRESSURE EXTENDING INTO THE NORTHERN PLAINS WILL WORK TO KEEP
THE LOCAL AREA UNDER SCT/SKC SKIES AND VFR CONDITIONS TONIGHT
THROUGH SUNDAY. SFC GRADIENT DOESN/T SLACKEN TOO MUCH...SO EXPECT
WINDS TO HOLD MOSTLY IN THE 10-15 KT RANGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
CLIMATE......RRS
AVIATION.....RIECK