Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/19/14
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
954 PM EST TUE FEB 18 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH TONIGHT. ATLANTIC HIGH PRESSURE WILL
THEN PREVAIL THROUGH THURSDAY NIGHT. A COLD FRONT WILL SWEEP THROUGH
THE AREA ON FRIDAY...STALLING JUST OFFSHORE UNTIL STRONGER HIGH
PRESSURE BUILDS INTO THE AREA ON SUNDAY. A GULF LOW PRESSURE SYSTEM
MAY MOVE UP THE SOUTHEAST COAST NEXT TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A WARM FRONT WILL CONTINUE TO LIFT NORTH OF THE REGION
OVERNIGHT...AND TEMPS WILL NOT FALL BELOW THE 50S. AS OF
LATE TUESDAY EVENING...SHOWERS/ISOLATED THUNDERSTORMS ALONG THE
WARM FRONT REMAINED WEST OF THE FORECAST AREA. THE 19/00Z NAM
SUGGESTS THAT SHOWERS WILL SPREAD EAST/SOUTHEAST WITHIN ISENTROPIC
ASCENT REGIME ENHANCED BY A DEVELOPING 30-40 KT SOUTHWESTERLY LOW
LEVEL JET...BRUSHING INLAND NORTHERN COUNTIES OVERNIGHT.
HOWEVER....HIGH RESOLUTION GUIDANCE INCLUDING THE LATEST HRRR AND
RUC13 SUGGEST THAT MOST/ALL PRECIPITATION WILL BYPASS FORECAST AREA
TO THE WEST/NORTH. MAINTAINED SLIGHT CHANCE/CHANCE POPS OVERNIGHT
ACROSS FAR INLAND/NORTHERN COUNTIES...BUT ADDITIONAL ADJUSTMENTS
TOWARD DIMINISHING POPS COULD BE REQUIRED OVERNIGHT. ELEVATED
INSTABILITY STILL JUSTIFIES A SLIGHT CHANCE OF THUNDERSTORMS IN
THESE AREAS.
ADDED A MENTION OF FOG ALONG/SOUTH OF THE SAVANNAH RIVER...WHERE
HIGH LEVEL CLOUD COVER...HIGHEST DEWPOINTS AND THE WEAKEST SURFACE
PRESSURE GRADIENT WILL PREVAIL.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
A RELATIVELY ZONAL FLOW ALOFT WILL PREVAIL ON WEDNESDAY WHILE AN 850
MB RIDGE AXIS STRENGTHENS OVER GA/FL. THE WARM FRONT SHOULD BE WELL
NORTH OF THE AREA BY WEDNESDAY MORNING. WARM ADVECTION WILL BE
ONGOING AS WSW WINDS OF 25-30 KT AROUND 850 MB CUT ACROSS ISOTHERMS.
ADDITIONALLY WE EXPECT CONSIDERABLE SUNSHINE AS MOST OF THE CLOUDS
WILL BE NORTH OF THE AREA. WE NUDGED HIGH TEMPS UP A COUPLE DEGREES
TO INDICATE UPPER 70S PRETTY MUCH EVERYWHERE. THE ONLY EXCEPTION IS
ALONG THE IMMEDIATE COAST WHERE A RESULTANT SEABREEZE WILL DROP
TEMPERATURES DURING THE AFTERNOON.
BY THURSDAY THE 500 MB PATTERN WILL BEGIN TO SHIFT TO A LONGWAVE
TROUGH ACROSS THE CENTRAL UNITED STATES. MEANWHILE THE 850 MB RIDGE
OVER THE WESTERN ATLANTIC WILL STRENGTHEN AND LOW-LEVEL FLOW WILL
BACK TO SOUTHERLY AT 30-35 KT. MOISTURE FIELDS SUPPORT MOSTLY SUNNY
SKIES EXCEPT FOR INCREASING CIRRUS. BASED ON THICKNESS PROGS WE
EXPECT MANY AREAS TO TOUCH 80 DEGREES DURING THE AFTERNOON. AGAIN
THE ONLY EXCEPTION WILL BE THE IMMEDIATE COAST WHERE A SEABREEZE
WILL COOL THINGS DOWN QUITE A BIT BEFORE TEMPS HAVE A CHANCE TO GET
TERRIBLY WARM.
THURSDAY NIGHT...AS THE LOW-LEVEL FLOW STRENGTHENS AND BACKS... LOW
LEVEL DEWPOINTS WILL INCREASE INTO THE LOWER TO MIDDLE 60S. PWATS
WILL FURTHER INCREASE TO AROUND 1.40 INCHES ON FRIDAY AHEAD OF THE
APPROACHING COLD FRONT. THE EXACT TIMING OF THE FRONTAL PASSAGE AND
ANY ASSOCIATED CONVECTION ON FRIDAY IS STILL UNCLEAR. HOWEVER LATE
MORNING THROUGH MID AFTERNOON IS WHERE THE MODEL CONSENSUS IS. THE
UPPER DYNAMICS ARE NOT TERRIBLY IMPRESSIVE BUT THE ABUNDANCE OF
LOW-LEVEL MOISTURE AHEAD OF THE FRONT SUPPORTS AT LEAST SCATTERED
SHOWERS WITH A FEW THUNDERSTORMS. MODEL SOUNDINGS ARE NOT TOO
IMPRESSIVE EITHER...SHOWING A CONSIDERABLE 700-850 MB CAP. THUS WE
ARE NOT TOO CONCERNED ABOUT THE SEVERE WEATHER POTENTIAL ON FRIDAY.
HOWEVER...IT CERTAINLY BEARS WATCHING...SINCE A MIDDAY COLD FRONTAL
PASSAGE IS MORE CLIMATOLOGICALLY FAVORABLE FOR SEVERE WEATHER THAN A
NOCTURNAL EVENT.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
IN GENERAL...MEDIUM RANGE GUIDANCE SUGGESTS THAT THE COLD FRONT
WILL PUSH SOUTH AND EAST OF THE REGION FRIDAY NIGHT INTO SATURDAY.
THOUGH IT IS SOMEWHAT UNCLEAR HOW FAR OFFSHORE THE FRONT WILL GO
BEFORE TEMPORARILY STALLING. THE 12Z GUIDANCE IS A BIT MORE
PROGRESSIVE THAN PREVIOUSLY WITH ONLY SLIGHT CHANCES FOR SHOWERS
OVER THE AREA INTO THE WEEKEND.
DRY HIGH PRESSURE BUILDS MORE FIRMLY INTO THE REGION SUNDAY NIGHT
AND MONDAY...THEN A GULF LOW PRESSURE SYSTEM COULD AFFECT THE
SOUTHEAST U.S. ON TUESDAY.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
AT LEAST OCCASIONAL MVFR VISIBILITY STILL EXPECTED
OVERNIGHT...ALTHOUGH PERSISTENT SURFACE WINDS AND STRENGTHENING WINDS
JUST ABOVE THE SURFACE COULD LIMIT FOG POTENTIAL OVERNIGHT. IFR OR
LOWER CEILINGS CANNOT BE RULED OUT AS A WARM FRONT LIFTS NORTH
THROUGH THE REGION OVERNIGHT...BUT MODEL SOUNDINGS ESPECIALLY THE
19/00Z NAM SUGGEST THAT THE PROBABILITY FOR IFR CEILINGS REMAINS
LOW. SHOWERS WILL LIKELY BYPASS KSAV AND COULD EVEN REMAIN NORTH
OF KCHS. ALSO...LOW LEVEL WIND SHEAR WILL DEVELOP AT KCHS AND
KSAV OVERNIGHT. SW WINDS WILL GUST 20-25 KT BY LATE WEDNESDAY
MORNING/EARLY WEDNESDAY AFTERNOON AS THE MIXED LAYER DEEPENS.
EXTENDED AVIATION OUTLOOK...MVFR CIGS/VSBYS POSSIBLE EACH MORNING
WITH FOG. FLIGHT RESTRICTIONS EXPECTED IN SHOWERS/THUNDERSTORMS AS
A COLD FRONT PUSHES THROUGH THE TERMINALS FRIDAY AND FRIDAY NIGHT.
&&
.MARINE...
OVERNIGHT...DEWPOINTS IN THE 50S AND SOUTHERLY WINDS WILL SUPPORT
PATCHY FOG...BUT SIGNIFICANT/DENSE FOG IS NOT EXPECTED. S/SW WINDS
WILL INCREASE TO 10-15 KT OVERNIGHT. SEAS WILL RANGE FROM 2-3 FT
NEARSHORE WATERS TO 3-4 FT BEYOND 20 NM.
THE PRIMARY CONCERN WEDNESDAY THROUGH FRIDAY WILL BE SEA FOG. AS
DEWPOINTS CREEP UPWARD AND FLOW OVER THE COOL SHELF WATERS...
CONDITIONS WILL BECOME INCREASINGLY FAVORABLE FOR SEA FOG...AND SEA
FOG COULD BECOME LOCALLY DENSE AS EARLY AS WEDNESDAY NIGHT OR
THURSDAY. THEN...AREAS OF FOG WILL PERSIST UNTIL A COLD FRONT PUSHES
OFFSHORE LATE FRIDAY OR FRIDAY NIGHT.
WINDS/SEAS WILL BE BELOW ADVISORY LEVELS WEDNESDAY AND WEDNESDAY
NIGHT. THEN SOUTHERLY WINDS INCREASE THURSDAY AS A TROUGH DEVELOPS
OVER THE EASTERN UNITED STATES AND A COLD FRONT SWEEPS THROUGH
FRIDAY. WE EXPECT MARGINAL SMALL CRAFT ADVISORY CONDITIONS FROM
THURSDAY AFTERNOON INTO FRIDAY FOR MOST OF THE WATERS EXCEPT
CHARLESTON HARBOR. CONDITIONS WILL IMPROVE EARLY IN THE WEEKEND.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...SPR
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...SPR
MARINE...JRL/SPR
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
417 PM EST MON FEB 17 2014
.SYNOPSIS...
A WEAK FRONT TO CROSS THE AREA OVERNIGHT. HIGH PRESSURE WILL
BRIEFLY TAKE HOLD TUESDAY. ANOTHER FRONT WILL AFFECT THE REGION
FRIDAY. A WARMING TREND IS STILL ON TAP FOR THIS WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
TONIGHT...HIGH PRESSURE ALONG THE EAST COAST WILL SLIDE OFFSHORE
ALLOWING A COLD FRONT TO CROSS THE AREA OVERNIGHT. MOISTURE WITH
THE FRONT WILL REMAIN LIMITED AND MOSTLY CONFINED TO THE LOW
LEVELS. AS SUCH HAVE REMAINED WITH SLIGHT CHANCE POPS ACROSS THE
NORTHERN AND WESTERN MIDLANDS WITH NO POPS ELSEWHERE AS DOWNSLOPING
FURTHER DIMINISHES REMAINING MOISTURE. INCREASING CLOUDS SHOULD
KEEP OVERNIGHT LOWS IN THE LOW TO MID 40S.
TUESDAY...THE FRONT WILL MOVE EAST OF THE MIDLANDS AND CSRA
AROUND SUNRISE. HIGH PRESSURE WILL QUICKLY CROSS THE AREA AS THE
FRONT BECOMES STATIONARY ALONG THE GULF COAST. WENT WITH MOS
CONSENSUS FOR HIGHS TUESDAY IN THE MID 60S TO LOWER 70S.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...UPPER AND SURFACE LOW
PRESSURE WILL BE OFF THE NEW ENGLAND COAST BY TUESDAY NIGHT WITH
THE ASSOCIATED FRONT ALSO OFFSHORE. ANOTHER AREA OF SURFACE LOW
PRESSURE WILL BE CENTERED OVER SOUTH CENTRAL CANADA WITH A COLD
FRONT DRAPED ACROSS THE OHIO AND TENNESSEE VALLEYS. MOISTURE AND
CLOUDINESS WILL INCREASE ACROSS THE FORECAST AREA AHEAD OF THE
FRONT LATE TUESDAY INTO WEDNESDAY. GFS PRECIPITABLE WATER VALUES
ARE AROUND 1 INCH WEDNESDAY MORNING. THE FRONT WILL CROSS THE
FORECAST AREA WEDNESDAY MORNING BRINGING ONLY A SLIGHT CHANCE OF
RAIN. SURFACE HIGH PRESSURE WILL RETURN BY WEDNESDAY AFTERNOON.
ABOVE NORMAL TEMPERATURES ON WEDNESDAY IN THE LOWER TO MIDDLE 70S.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...MODELS ARE IN GOOD
AGREEMENT SHOWING A LARGE TROUGH DEVELOPING OVER THE ROCKIES
REGION BY EARLY THURSDAY. THE UPPER TROUGH WILL DIG TOWARD THE
CENTRAL PLAINS WITH A DOWNSTREAM RIDGE OVER THE EASTERN CONUS. AT
THE SURFACE...AN AREA OF LOW PRESSURE CENTERED OVER THE CENTRAL
PLAINS EARLY THURSDAY WILL SHIFT NORTHEASTWARD TOWARD THE GREAT
LAKES AND DEEPEN WITH A WARM FRONT EXTENDING INTO THE FORECAST
AREA. CONTINUED TO INDICATE A SLIGHT CHANCE OF RAIN ALONG THE WARM
FRONT ON THURSDAY. TEMPERATURES ON THURSDAY WILL BE ABOVE NORMAL
WITH UPPER RIDGING AND SOUTHERLY FLOW INTO THE AREA. EXPECT HIGHS
IN THE LOW TO MID 70S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
FRIDAY THROUGH FRIDAY NIGHT...SURFACE LOW PRESSURE WILL CONTINUE
TO DEEPEN AS IT SHIFTS NORTHEASTWARD INTO CANADA EARLY FRIDAY WITH
A COLD FRONT DRAPED ACROSS THE APPALACHIANS. MODELS SHOW AMPLE
MOISTURE ACROSS THE AREA FRIDAY MORNING WITH GFS PRECIPITABLE
WATER VALUES AROUND 1.4 INCHES AT 12Z. THE COLD FRONT WILL CROSS
THE FORECAST AREA DURING THE FRIDAY MORNING/EARLY AFTERNOON TIME
FRAME WITH RAIN LIKELY. THE SPC HAS NORTHERN AND CENTRAL GEORGIA
AND THE CAROLINAS IN ITS DAY 5 CONVECTIVE OUTLOOK. STRONG FLOW
ALOFT MAY RESULT IN A DAMAGING WIND THREAT. THE COLD FRONT SHOULD
BE EAST OF THE FORECAST AREA BY FRIDAY EVENING AS THE UPPER TROUGH
SHIFTS EASTWARD AND EXPANDS ACROSS THE EASTERN CONUS.
SATURDAY THROUGH MONDAY...THE FRONTAL BOUNDARY MAY STALL ALONG
THE COAST ON SATURDAY WITH SURFACE HIGH PRESSURE RIDGING INTO THE
FORECAST AREA BEHIND IT. MOISTURE WILL INCREASE AGAIN ON SUNDAY
WITH MODEL PRECIPITABLE WATER VALUES RETURNING TO OVER AN INCH.
THE NEXT COLD FRONT WILL APPROACH FROM THE WEST MONDAY WITH HIGH
PRESSURE AND DRY AIR RETURNING TUESDAY.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
HIGH CONFIDENCE FOR VFR THROUGH THE EVENING. HIGH PRESSURE OVER THE
AREA WILL MOVE OFFSHORE THIS EVENING ALLOWING A TROUGH OF LOW
PRESSURE TO CROSS THE AREA OVERNIGHT.
HIGH CLOUDS WILL CROSS THE TAF SITES THIS AFTERNOON. WILL SEE CLOUDS
INCREASING AND LOWERING DURING THE EVENING. BOTH THE RUC AND HRRR
MODELS INDICATING IFR CONDITION DEVELOPING AROUND 04Z. CONFIDENCE
STILL LOW...SO WILL KEEP VFR OVERNIGHT. BY 18/12Z THE FRONT WILL BE
EAST OF THE TAF SITES...SO HIGH CONFIDENCE FOR VFR DURING THE DAY
TUESDAY.
EXTENDED AVIATION OUTLOOK...CEILING RESTRICTIONS POSSIBLE WEDNESDAY
MORNING AS COLD FRONT CROSSES THE REGION AND AGAIN ON FRIDAY AS
A STRONG COLD FRONT MOVES THROUGH.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
249 PM EST MON FEB 17 2014
.SYNOPSIS...
HIGH PRESSURE ALONG THE COAST WILL MOVE OFFSHORE THIS EVENING
ALLOWING A WEAK FRONT TO CROSS THE AREA OVERNIGHT. HIGH PRESSURE
WILL BRIEFLY TAKE HOLD TUESDAY. ANOTHER FRONT WILL AFFECT THE
REGION FRIDAY. A WARMING TREND IS STILL ON TAP FOR THIS WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
HIGH PRESSURE ALONG THE EAST COAST WILL SLIDE OFFSHORE THIS
EVENING ALLOWING A COLD FRONT TO CROSS THE AREA TONIGHT. MOISTURE
WITH THE FRONT WILL REMAIN LIMITED AND MOSTLY CONFINED TO THE LOW
LEVELS. AS SUCH HAVE REMAINED WITH SLIGHT CHANCE POPS ACROSS THE
NORTHERN AND WESTERN MIDLANDS WITH NO POPS ELSEWHERE AS
DOWNSLOPING FURTHER DIMINISHES REMAINING MOISTURE. THE FRONT WILL
MOVE EAST OF THE MIDLANDS AND CSRA AROUND SUNRISE TUESDAY. HIGH
PRESSURE WILL QUICKLY CROSS THE AREA ON TUESDAY AS THE FRONT
BECOMES STATIONARY ALONG THE GULF COAST.
TEMPERATURES THIS AFTERNOON ARE WELL ON THE WAY TO HIGHS RANGING
FROM THE LOWER 50S NORTH TO MID 60S CSRA. INCREASING CLOUDS SHOULD
KEEP OVERNIGHT LOWS IN THE LOW TO MID 40S. WENT WITH MOS CONSENSUS
FOR HIGHS TUESDAY IN THE MID 60S TO LOWER 70S.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...UPPER AND SURFACE LOW
PRESSURE WILL BE OFF THE NEW ENGLAND COAST BY TUESDAY NIGHT WITH
THE ASSOCIATED FRONT ALSO OFFSHORE. ANOTHER AREA OF SURFACE LOW
PRESSURE WILL BE CENTERED OVER SOUTH CENTRAL CANADA WITH A COLD
FRONT DRAPED ACROSS THE OHIO AND TENNESSEE VALLEYS. MOISTURE AND
CLOUDINESS WILL INCREASE ACROSS THE FORECAST AREA AHEAD OF THE
FRONT LATE TUESDAY INTO WEDNESDAY. GFS PRECIPITABLE WATER VALUES
ARE AROUND 1 INCH WEDNESDAY MORNING. THE FRONT WILL CROSS THE
FORECAST AREA WEDNESDAY MORNING BRINGING ONLY A SLIGHT CHANCE OF
RAIN. SURFACE HIGH PRESSURE WILL RETURN BY WEDNESDAY AFTERNOON.
ABOVE NORMAL TEMPERATURES ON WEDNESDAY IN THE LOWER TO MIDDLE 70S.
WEDNESAY NIGHT THROUGH THURSDAY NIGHT...MODELS ARE IN GOOD
AGREEMENT SHOWING A LARGE TROUGH DEVELOPING OVER THE ROCKIES
REGION BY EARLY THURSDAY. THE UPPER TROUGH WILL DIG TOWARD THE
CENTRAL PLAINS WITH A DOWNSTREAM RIDGE OVER THE EASTERN CONUS. AT
THE SURFACE...AN AREA OF LOW PRESSURE CENTERED OVER THE CENTRAL
PLAINS EARLY THURSDAY WILL SHIFT NORTHEASTWARD TOWARD THE GREAT
LAKES AND DEEPEN WITH A WARM FRONT EXTENDING INTO THE FORECAST
AREA. CONTINUED TO INDICATE A SLIGHT CHANCE OF RAIN ALONG THE WARM
FRONT ON THURSDAY. TEMPERATURES ON THURSDAY WILL BE ABOVE NORMAL
WITH UPPER RIDGING AND SOUTHERLY FLOW INTO THE AREA. EXPECT HIGHS
IN THE LOW TO MID 70S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
FRIDAY THROUGH FRIDAY NIGHT...SURFACE LOW PRESSURE WILL CONTINUE
TO DEEPEN AS IT SHIFTS NORTHEASTWARD INTO CANADA EARLY FRIDAY WITH
A COLD FRONT DRAPED ACROSS THE APPALACHIANS. MODELS SHOW AMPLE
MOISTURE ACROSS THE AREA FRIDAY MORNING WITH GFS PRECIPITABLE
WATER VALUES AROUND 1.4 INCHES AT 12Z. THE COLD FRONT WILL CROSS
THE FORECAST AREA DURING THE FRIDAY MORNING/EARLY AFTERNOON TIME
FRAME WITH RAIN LIKELY. THE SPC HAS NORTHERN AND CENTRAL GEORGIA
AND THE CAROLINAS IN ITS DAY 5 CONVECTIVE OUTLOOK. STRONG FLOW
ALOFT MAY RESULT IN A DAMAGING WIND THREAT. THE COLD FRONT SHOULD
BE EAST OF THE FORECAST AREA BY FRIDAY EVENING AS THE UPPER TROUGH
SHIFTS EASTWARD AND EXPANDS ACROSS THE EASTERN CONUS.
SATURDAY THROUGH MONDAY...THE FRONTAL BOUNDARY MAY STALL ALONG
THE COAST ON SATURDAY WITH SURFACE HIGH PRESSURE RIDGING INTO THE
FORECAST AREA BEHIND IT. MOISTURE WILL INCREASE AGAIN ON SUNDAY
WITH MODEL PRECIPITABLE WATER VALUES RETURNING TO OVER AN INCH.
THE NEXT COLD FRONT WILL APPROACH FROM THE WEST MONDAY WITH HIGH
PRESSURE AND DRY AIR RETURNING TUESDAY.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
HIGH CONFIDENCE FOR VFR THROUGH THE EVENING. HIGH PRESSURE OVER THE
AREA WILL MOVE OFFSHORE THIS EVENING ALLOWING A TROUGH OF LOW
PRESSURE TO CROSS THE AREA OVERNIGHT.
HIGH CLOUDS WILL CROSS THE TAF SITES THIS AFTERNOON. WILL SEE CLOUDS
INCREASING AND LOWERING DURING THE EVENING. BOTH THE RUC AND HRRR
MODELS INDICATING IFR CONDITION DEVELOPING AROUND 04Z. CONFIDENCE
STILL LOW...SO WILL KEEP VFR OVERNIGHT. BY 18/12Z THE FRONT WILL BE
EAST OF THE TAF SITES...SO HIGH CONFIDENCE FOR VFR DURING THE DAY
TUESDAY.
EXTENDED AVIATION OUTLOOK...CEILING RESTRICTIONS POSSIBLE WEDNESDAY
MORNING AS COLD FRONT CROSSES THE REGION AND AGAIN ON FRIDAY AS
A STRONG COLD FRONT MOVES THROUGH.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
135 PM EST MON FEB 17 2014
.SYNOPSIS...
HIGH PRESSURE ALONG THE COAST WILL MOVE OFFSHORE THIS EVENING
ALLOWING A WEAK FRONT WILL CROSS THE AREA OVERNIGHT. HIGH PRESSURE
WILL BRIEFLY TAKE HOLD TUESDAY. ANOTHER FRONT WILL AFFECT THE
REGION FRIDAY. A WARMING TREND IS STILL ON TAP FOR THIS WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
HIGH PRESSURE ALONG THE EAST COAST WILL SLIDE OFFSHORE THIS
EVENING ALLOWING A COLD FRONT TO CROSS THE AREA TONIGHT. MOISTURE
WITH THE FRONT WILL REMAIN LIMITED AND MOSTLY CONFINED TO THE LOW
LEVELS. AS SUCH HAVE REMAINED WITH SLIGHT CHANCE POPS ACROSS THE
NORTHERN AND WESTERN MIDLANDS WITH NO POPS ELSEWHERE AS
DOWNSLOPING FURTHER DIMINISHES REMAINING MOISTURE. THE FRONT WILL
MOVE EAST OF THE MIDLANDS AND CSRA AROUND SUNRISE TUESDAY. HIGH
PRESSURE WILL QUICKLY CROSS THE AREA ON TUESDAY AS THE FRONT
BECOMES STATIONARY ALONG THE GULF COAST.
TEMPERATURES THIS AFTERNOON ARE WELL ON THE WAY TO HIGHS RANGING
FROM THE LOWER 50S NORTH TO MID 60S CSRA. INCREASING CLOUDS SHOULD
KEEP OVERNIGHT LOWS IN THE LOW TO MID 40S. WENT WITH MOS CONSENSUS
FOR HIGHS TUESDAY IN THE MID 60S TO LOWER 70S.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
THE NEXT LOW PRESSURE SYSTEM WILL SWING THROUGH THE GREAT LAKES
REGION TUESDAY NIGHT...PUSHING ANOTHER COLD FRONT EASTWARD AND
BRING THE STATIONARY FRONT FROM THE COAST BACK NORTHWARD. THIS
WILL BRING A WEAK DISTURBANCE THROUGH THE FORECAST AREA LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING. MOISTURE WITH THE FRONT WILL
AGAIN BE LIMITED WITH MODEL SOUNDINGS INDICATING DRY AIR IN THE
MID LEVELS. HAVE ADJUSTED THE POPS SLIGHTLY REMAINING WITH CHANCE
OVER MOST OF THE FORECAST AREA...HOWEVER QPF AMOUNTS WILL
GENERALLY BE A COUPLE OF HUNDREDTHS. HIGH PRESSURE BUILDING BACK
IN DURING THE AFTERNOON HOURS AND AGAIN PUSH THE STATIONARY FRONT
JUST SOUTH OF THE AREA FOR WEDNESDAY NIGHT. TEMPERATURES WILL
CONTINUE TO WARM WITH AFTERNOON HIGHS IN THE LOWER 70S ON
WEDNESDAY...AND OVERNIGHT LOWS IN THE UPPER 40S TO LOWER 50S EACH
NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
UPPER LEVEL PATTERN WILL REMAIN LOW ZONAL THROUGH THE PERIOD
ALLOWING FOR PROGRESSION OF SYSTEMS THROUGH THE FORECAST AREA. LOW
PRESSURE WILL BE DEEPENING AS IT CROSSES THE CENTRAL MS VALLEY ON
THURSDAY AND MOVES INTO THE CENTRAL GREAT LAKES THURSDAY NIGHT.
THE ASSOCIATED COLD FRONT WILL CROSS THE GULF STATES THURSDAY
NIGHT AND INTO THE FORECAST AREA FRIDAY. THIS WILL BRING
INCREASING CHANCES OF RAIN SHOWERS TO THE AREA FOR MUCH OF FRIDAY.
HAVE ONLY INCREASED POPS SLIGHTLY FOR THIS TIME PERIOD AS MODELS
AGREE ON SYNOPTIC SITUATION BUT DISAGREE ON TIMING WITH GFS
CURRENTLY SLOWER THAN ECMWF. THE FRONT WILL STALL ALONG THE COAST
FRIDAY EVENING WITH HIGH PRESSURE AND DRIER AIR BUILDING INTO THE
REGION. CONFIDENCE LOW FOR SATURDAY AND SUNDAY AS GFS RAPIDLY
RETURNS MOISTURE TO THE AREA ON SATURDAY WHILE ECMWF HANGS ON TO
DRY AIR INTO SUNDAY. AS A RESULT ON MINOR ADJUSTMENTS MADE TO
SATURDAY AND SUNDAY. TEMPERATURES THROUGH THE LONG TERM WILL ABOVE
NORMAL.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
HIGH CONFIDENCE FOR VFR THROUGH THE EVENING. HIGH PRESSURE OVER THE
AREA WILL MOVE OFFSHORE THIS EVENING ALLOWING A TROUGH OF LOW
PRESSURE TO CROSS THE AREA OVERNIGHT.
HIGH CLOUDS WILL CROSS THE TAF SITES THIS AFTERNOON. WILL SEE CLOUDS
INCREASING AND LOWERING DURING THE EVENING. BOTH THE RUC AND HRRR
MODELS INDICATING IFR CONDITION DEVELOPING AROUND 04Z. CONFIDENCE
STILL LOW...SO WILL KEEP VFR OVERNIGHT. BY 18/12Z THE FRONT WILL BE
EAST OF THE TAF SITES...SO HIGH CONFIDENCE FOR VFR DURING THE DAY
TUESDAY.
EXTENDED AVIATION OUTLOOK...CEILING RESTRICTIONS POSSIBLE WEDNESDAY
MORNING AS COLD FRONT CROSSES THE REGION AND AGAIN ON FRIDAY AS
A STRONG COLD FRONT MOVES THROUGH.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
906 PM CST TUE FEB 18 2014
.DISCUSSION...
759 PM CST
ONLY MINOR TWEAKS TO NEAR TERM OF FORECAST THIS EVENING...MAINLY TO
BUMP OVERNIGHT MIN TEMPS UP JUST A BIT. FARTHER OUT...HAVE HIT
HARDER AT THE POTENTIAL FOR VERY WINDY CONDITIONS THURSDAY NIGHT
INTO FRIDAY BEHIND DEPARTING DEEPENING LOW PRESSURE SYSTEM.
TEMPS STILL IN THE MID 30S TO LOW 40S IN SOME SPOTS ACROSS THE
FORECAST AREA THIS EVENING...IN SOUTH FLOW AHEAD OF A COLD FRONT
WHICH WAS JUST ENTERING NORTHWEST IL AT 01Z. COLD FRONT WILL
CONTINUE TO PUSH EAST THROUGH THE REMAINDER OF THE EVENING AND EARLY
OVERNIGHT HOURS WITH A WIND SHIFT TO THE WEST BEHIND THE BOUNDARY.
HOWEVER...FRONT IS OF PACIFIC ORIGIN AND TEMPS CURRENTLY NOT FALLING
OFF TOO MUCH BEHIND IT WITH READINGS IN THE MID/UPPER 30S STILL
ACROSS IA. HAD ADJUSTED HOURLY TEMP GRIDS FOR A MUCH SLOWER FALL
EARLIER AND HAVE BUMPED OVERNIGHT MINS A BIT INTO THE 25-30 DEGREE
RANGE FOR MOST AREAS AND THIS MIGHT EVEN BE A DEGREE OR TWO TOO COOL
COME MORNING. OTHERWISE...PATCHY MID/HIGH CLOUDS OVERNIGHT WITH
UPPER TROUGH PROPAGATING ACROSS THE REGION. ANY LINGERING CLOUDS
SHOULD QUICKLY CLEAR EARLY WEDNESDAY MORNING AS TROUGH MOVES EAST
AND SFC RIDGE BUILDS IN FROM THE WEST.
FARTHER OUT...IN ADDITION TO THE CHALLENGES OF PRECIP TYPE/RAIN
AMOUNTS AND THUNDER POTENTIAL THURSDAY...IT ALSO APPEARS THAT VERY
WINDY SYNOPTIC CONDITIONS WILL DEVELOP LATE THURSDAY AND PERSIST
THROUGH THE NIGHT INTO EARLY FRIDAY. GUIDANCE IN GOOD AGREEMENT IN
DEVELOPING 993-ISH MB LOW INTO WESTERN IL BY 18Z THURSDAY...AND
RAPIDLY DEEPENING IT TO NEAR 985 MB AS IT LIFTS INTO EASTERN WI
BY EVENING AND TO NEAR 980 MB OVER THE UPPER PENINSULA OF MICH BY
MIDNIGHT. RESULTING ISALLOBARIC RISE/FALL COUPLET AND WIND
RESPONSE ARE EQUALLY IMPRESSIVE...WITH FORECAST SOUNDINGS
INDICATING THE POTENTIAL FOR WEST WINDS TO GUST 40 TO 50+ MPH
BEHIND THE DEEPENING LOW THURSDAY EVENING. SLOW DIMINISHING TREND
THEN LASTS INTO FRIDAY. HAVE BUMPED WIND GUSTS THROUGH THE
THURSDAY NIGHT/FRIDAY PERIOD BASED ON THESE SOLID MODEL
TRENDS/INDICATIONS AND WILL HIGHLIGHT IN UPDATED HWO.
RATZER
//PREV DISCUSSION...
303 PM CST
TONIGHT THROUGH WEDNESDAY...
THE HEAT SOURCE HAS BEEN FOUND...WITH TEMPS SOARING INTO THE 40S
TODAY ACROSS MUCH OF THE REGION. IF IT WAS NOT FOR THE THICK
SNOWPACK...TEMPS THIS AFTN MAY HAVE MIRRORED WHAT IS BEING
EXPERIENCED ACROSS PORTIONS OF MISSOURI THAT HAVE SOARED INTO THE
50S/60S. EITHER WAY...THE 40S WILL LIKELY FEEL BALMY CONSIDERING
WHERE TEMPS HAVE BEEN OVER THE PAST SEVERAL WEEKS. FULL SUNSHINE
WILL PERSIST AS BROAD SFC RIDGING PROVIDES MINIMAL CLOUDS ACROSS THE
REGION. SOUTHERLY FLOW WILL PERSIST THROUGH THE NEXT COUPLED OF
DAYS...HOWEVER A BRIEF LULL AS A WEAK FRONTAL BOUNDARY APPROACHES
THE FORECAST AREA THIS EVENING FROM THE NORTHWEST. CURRENT ANALYSIS
HAS THE BOUNDARY STRETCHING FROM COPPER HARBOR IN THE UPPER
PENINSULA OF MI...MEANDERING SOUTHWEST THROUGH CENTRAL IOWA. VISIBLE
IMAGERY SHOWS SOME CLOUDS ASSOCIATED WITH THIS FEATURE...HOWEVER NO
PRECIP IS CURRENTLY DEPICTED. SOME OF THE HI-RES GUIDANCE CONTINUE
TO HINT AT PERHAPS SOME SPRINKLES. AT THIS TIME VERY LOW CONFIDENCE
THAT ANY PRECIP WILL DEVELOP OVER THE FORECAST AREA...SO HAVE HELD
ONTO THE DRY FORECAST THIS EVENING.
BEHIND THE BOUNDARY...BROAD SFC RIDGING OVER THE CENTRAL PLAINS WILL
PUSH EAST. THIS WILL ALLOW FLOW TO TURN MORE WESTERLY FOR
WED...EVENTUALLY TURNING SOUTHWESTERLY AS THE FLOW REMAINS
PROGRESSIVE AND THE RIDGE EXITS THE STAGE FOR THE EAST COAST WED
NGT. DESPITE YET ANOTHER DAY OF FULL SUNSHINE WED...THE LGT WESTERLY
FLOW WILL LIKELY KEEP TEMPS SOMEWHAT IN CHECK. ALTHOUGH HAVE NUDGED
TEMPS A DEGREE OR TWO WARMER TO HOVER ARND 40 FOR MOST PLACES. THEN
THE FOCUS TURNS TOWARDS THE LATE WED NGT INTO THUR TIMEFRAME...AND
WHAT CONTINUES TO LOOK VERY CONCERNING FOR FLOODING/CONVECTION.
CONFIDENCE TONIGHT THROUGH WEDNESDAY...HIGH.
THURSDAY...
MID-LVL RIDGE WILL SLIDE OVERHEAD WED EVENING...WITH A THERMAL RIDGE
STEADILY LIFTING OVERHEAD AS WELL. TEMPS ALOFT SHUD PUSH ABOVE 0C BY
3Z THUR...THEN CONTINUE TO WARM. THIS PRESENT A SIGNIFICANT
CHALLENGE...AS A LLVL INVERSION WILL DEVELOP WITH SFC TEMPS COOLING
JUST AFTER SUNSET WED NGT TO THE UPR 20S/ARND 30. BUT WITH THE
STEADY SOUTHERLY FLOW LIFTING OVERHEAD...AND PRECIP LOOKING TO BE
DELAYED A LITTLE...THE ONSET OF PRECIP MAY ACTUALLY FALL AS LIQUID
RAIN RATHER THAN FREEZING RAIN. SOUNDINGS CONTINUE TO SUGGEST A 6HR
WINDOW OF FZRA AND HAVE MAINTAINED THIS IN THE FORECAST...BUT WITH
WARM/MOIST AIR LIFTING NORTH FROM RETURN FLOW OFF OF THE DEPARTING
SFC RIDGE OVER THE SOUTHEAST...PWAT VALUES ARE PROGGED TO BE
HOVERING ARND 1"...WHICH IS ROUGHLY 4 SIGMA ABOVE NORMAL. THE LATEST
HI-RES LCL WRF INDICATES ONSET OF MOISTURE/PRECIP DOES NOT ARRIVE
UNTIL CLOSER TO DAYBREAK THUR.
EXPECT THE SNOWPACK AT THE ONSET TO ABSORB SOME OF THE LIQUID THAT
FALLS INTO IT...HOWEVER WITH DEW POINTS POISED TO RISE ABOVE
FREEZING DURING THE DAY THIS SHOULD UNFORTUNATELY PROVIDE AN
EFFICIENT MEANS FOR THE SNOWPACK TO BEGIN MELTING AT A FAST RATE.
500MB TROUGH AXIS WILL BE SLOW TO EJECT EAST OF THE ROCKIES EARLY
THUR...AS THE SFC WAVE DEVELOPS. GUIDANCE CONTINUES TO SUGGEST A
SECONDARY WEAKER LOW WILL DEVELOP OVER THE NORTHERN PLAINS...HOWEVER
THE TWO WILL CONSOLIDATE INTO A STRONGER SFC WAVE OVER CHICAGO THUR
AFTN/EVE...AS THE DRY SLOT QUICKLY LIFTS NORTHEAST TOWARDS THE
FORECAST AREA.
THERE REMAINS STRONG ASCENT AHEAD OF THE LOW...WITH CONSIDERABLE
LLVL SHEAR IN THE LOWEST 0-3KM AGL THUR. WITH MIDLVL CAPE PROGGED
ARND 300-400J/KG...HAVE MAINTAINED THE MENTION OF THUNDER...AND IT
IS CONCEIVABLE THAT SOME OF THE STORMS COULD BECOME STRONG. SPC HAS
CONTINUED THE SLIGHT RISK FOR SEVERE WEATHER THUR...MAINLY ALONG AND
EAST OF A PONTIAC TO GARY LINE. THE MAIN THREAT FROM THUNDERSTORMS
LOOKS TO BE WIND...HOWEVER GIVEN HOW LOW THE FREEZING LEVEL WILL
BE...AND WITH THE SHEAR IN THE LLVLS...IT IS POSSIBLE FOR AN
ISOLATED TORNADO. TO FURTHER COMPLICATE THE FORECAST THUR...THE
MELTING SNOWPACK WILL LIKELY RESULT IN AREAS OF FOG. TEMPS THUR
REMAIN A CHALLENGE...HOWEVER GUIDANCE HAS BECOME SOMEWHAT MORE
CONSISTENT WITH A WARMER SOLUTION PRODUCING MID/UPR 40S OVER THE
FORECAST AREA...AND PERHAPS THE LOW 50S SOUTH OF LASALLE TO KANKAKEE
TO VALPO.
CONFIDENCE...HIGH.
FRIDAY THROUGH EARLY NEXT WEEK...
MID-LVL TROUGH AXIS CONTINUES TO SLIDE EAST INTO THE PLAINS THUR
NGT...ARRIVING OVER THE GREAT LAKES REGION EARLY FRI. SFC LOW WILL
BE WRAPPING UP OVER LAKE MICHIGAN...WITH A DRY WEDGE LIFTING ACROSS
THE FORECAST AREA LATE THUR NGT. THIS SHOULD BRING AN END TO THE
HEAVY/STEADY RAIN/THUNDER THUR AFTN...WITH TEMPS COOLING BEHIND A
FRONTAL BOUNDARY AND POSSIBLY BECOMING MIXED WITH SNOW.
THEN FOR THE UPCOMING WEEKEND TEMPS TREND BACK TOWARDS WHAT HAS BEEN
THE PATTERN ALL WINTER...BROAD TROUGHING OVER THE GREAT LAKES. TEMPS
FALL BACK INTO THE 20S FOR THE WEEKEND THROUGH EARLY NEXT
WEEK...WITH A FEW WEAK MID-LVL WAVES FLOATING OVER THE REGION AND
POSSIBLY BRINGING SOME LIGHT SNOW.
CONFIDENCE...HIGH.
BEACHLER
&&
.HYDROLOGY...
MODELS CONTINUE TO TREND TOWARD A STRONGER SYSTEM THURSDAY WITH
RESULTANT MORE SIGNIFICANT SURGE OF WARM AIR AND HIGH DEWPOINTS.
ABOUT THE ONLY SAVING GRACE LOOKS TO BE A RELATIVELY SHORT TIME
PERIOD WITH DEWPOINTS ABOVE 40F...ESPECIALLY NORTHWEST CWA...BUT
STILL THE HIGH DEWPOINTS SHOULD RESULT IN QUITE A BIT OF SNOW MELT
ADDING TO THE RUNOFF OF THE POTENTIALLY MODERATE TO HEAVY
RAINFALL. THE BOTH WILL RESULT IN A QUICK INCREASE IN STREAM FLOW
AND A ELEVATED THREAT OF ICE JAM FLOODING AS MASSIVE AMOUNTS OF
ICE ARE DISLODGED DUE TO THE INCREASED STREAM FLOW. WILL LIKELY
NEED A FLOOD WATCH FOR THIS TIME PERIOD...BUT IN THE MEANTIME WILL
GIVE A QUICK FRESHENING UP TO THE ESF.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* POTENTIAL FOR IFR-MVFR STRATUS TO DEVELOP TONIGHT.
DZ
//DISCUSSION...UPDATED 00Z...
LOW LEVEL WIND STARTING TO EASE AHEAD OF COLD FRONT OVER EASTERN IA.
AMDAR AND RAP DATA INDICATE LOW LEVEL MAX WIND FIELD TO CONTINUE TO
TRANSITION EAST AND OUT OF TERMINAL AREA BY MID EVENING.
FORECAST MODEL RUNS CONTINUE TO INDICATE THE POTENTIAL FOR A THIN
LOW LEVEL CLOUD DECK TO DEVELOP ABOVE THE MELTING SNOW PACK
FOLLOWING DRY FRONTAL PASSAGE.
PROGRESSIVE PATTERN TO PERSIST AS HIGH PRESSURE TO MOVE OVER INTO
WEDNESDAY AND WILL HOLD WIND SPEEDS DOWN.
DZ
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* LOW CONFIDENCE IN MVFR-IFR STRATUS DVLPMT OVERNIGHT.
* HIGH CONFIDENCE IN ALL OTHER PARAMETERS.
DZ
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...FZRA LIKELY AND A CHC OF TSRA EARLY THEN RA WITH A
CHANCE OF TSRA. CHC LGT SHRA OR SHSN LATE.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
&&
.MARINE...
225 PM CST
WILL LEAVE THE SMALL CRAFT ADVISORY AS IS.
LOW PRESSURE IS OVER WESTERN ONTARIO AND ITS COLD FRONT WILL PASS
OVER THE LAKE TONIGHT. WINDS WILL TURN WEST BEHIND THE FRONT. A
WEAK SURFACE RIDGE PASSES OVER THE LAKE TOMORROW WITH WINDS TURNING
SOUTH BEHIND IT TOMORROW NIGHT. THE NEXT LOW PRESSURE SYSTEM IS THE
BIG CONCERN. TWO LOWS COMBINE OVER THE SOUTHERN END OF THE LAKE
THURSDAY AFTERNOON. GUIDANCE SHOWS A HIGH LEVEL OF AGREEMENT WITH
THIS LOW...INCLUDING IT DEEPENING AS IT MOVES NORTH UP THE LAKE
THROUGH FRIDAY.
AS SUCH GALES ARE EXPECTED LATE THURSDAY THROUGH FRIDAY. WINDS WILL
VARY ACROSS THE LAKE WITH SOUTH WINDS OVER THE SOUTH HALF AND EAST
OVER THE NORTH HALF. WINDS BECOME SOUTHWEST ACROSS THE LAKE
THURSDAY NIGHT AND INCREASE TO HIGH END GALES...TO 45 KT. THE HIGH
END OF GUIDANCE SUGGESTED STORM FORCE WINDS...BUT WILL CAP WINDS AT
HIGH END GALES FOR NOW. WINDS FINALLY BEGIN TO SUBSIDE FRIDAY
MORNING AS THE LOW CONTINUES TO PULL AWAY. HOWEVER...THE LOW
REMAINS OVER EASTERN ONTARIO THROUGH SUNDAY...SO WINDS WILL BE WEST
ACROSS THE LAKE THROUGH SUNDAY AS WELL.
THIS FAR OUT...WILL NOT ISSUE A GALE RELATED PRODUCT...BUT ONE WILL
BE NEEDED FOR THURSDAY AND FRIDAY. GALE FORCE GUSTS ARE LIKELY IN
THE NEARSHORE WATERS AS WELL.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION...CORRECTED
NWS CHICAGO/ROMEOVILLE IL
804 PM CST TUE FEB 18 2014
.DISCUSSION...
759 PM CST
ONLY MINOR TWEAKS TO NEAR TERM OF FORECAST THIS EVENING...MAINLY TO
BUMP OVERNIGHT MIN TEMPS UP JUST A BIT. FARTHER OUT...HAVE HIT
HARDER AT THE POTENTIAL FOR VERY WINDY CONDITIONS THURSDAY NIGHT
INTO FRIDAY BEHIND DEPARTING DEEPENING LOW PRESSURE SYSTEM.
TEMPS STILL IN THE MID 30S TO LOW 40S IN SOME SPOTS ACROSS THE
FORECAST AREA THIS EVENING...IN SOUTH FLOW AHEAD OF A COLD FRONT
WHICH WAS JUST ENTERING NORTHWEST IL AT 01Z. COLD FRONT WILL
CONTINUE TO PUSH EAST THROUGH THE REMAINDER OF THE EVENING AND EARLY
OVERNIGHT HOURS WITH A WIND SHIFT TO THE WEST BEHIND THE BOUNDARY.
HOWEVER...FRONT IS OF PACIFIC ORIGIN AND TEMPS CURRENTLY NOT FALLING
OFF TOO MUCH BEHIND IT WITH READINGS IN THE MID/UPPER 30S STILL
ACROSS IA. HAD ADJUSTED HOURLY TEMP GRIDS FOR A MUCH SLOWER FALL
EARLIER AND HAVE BUMPED OVERNIGHT MINS A BIT INTO THE 25-30 DEGREE
RANGE FOR MOST AREAS AND THIS MIGHT EVEN BE A DEGREE OR TWO TOO COOL
COME MORNING. OTHERWISE...PATCHY MID/HIGH CLOUDS OVERNIGHT WITH
UPPER TROUGH PROPAGATING ACROSS THE REGION. ANY LINGERING CLOUDS
SHOULD QUICKLY CLEAR EARLY WEDNESDAY MORNING AS TROUGH MOVES EAST
AND SFC RIDGE BUILDS IN FROM THE WEST.
FARTHER OUT...IN ADDITION TO THE CHALLENGES OF PRECIP TYPE/RAIN
AMOUNTS AND THUNDER POTENTIAL THURSDAY...IT ALSO APPEARS THAT VERY
WINDY SYNOPTIC CONDITIONS WILL DEVELOP LATE THURSDAY AND PERSIST
THROUGH THE NIGHT INTO EARLY FRIDAY. GUIDANCE IN GOOD AGREEMENT IN
DEVELOPING 993-ISH MB LOW INTO WESTERN IL BY 18Z THURSDAY...AND
RAPIDLY DEEPENING IT TO NEAR 985 MB AS IT LIFTS INTO EASTERN WI
BY EVENING AND TO NEAR 980 MB OVER THE UPPER PENINSULA OF MICH BY
MIDNIGHT. RESULTING ISALLOBARIC RISE/FALL COUPLET AND WIND
RESPONSE ARE EQUALLY IMPRESSIVE...WITH FORECAST SOUNDINGS
INDICATING THE POTENTIAL FOR WEST WINDS TO GUST 40 TO 50+ MPH
BEHIND THE DEEPENING LOW THURSDAY EVENING. SLOW DIMINISHING TREND
THEN LASTS INTO FRIDAY. HAVE BUMPED WIND GUSTS THROUGH THE
THURSDAY NIGHT/FRIDAY PERIOD BASED ON THESE SOLID MODEL
TRENDS/INDICATIONS AND WILL HIGHLIGHT IN UPDATED HWO.
RATZER
&&
.PREV DISCUSSION...
303 PM CST
TONIGHT THROUGH WEDNESDAY...
THE HEAT SOURCE HAS BEEN FOUND...WITH TEMPS SOARING INTO THE 40S
TODAY ACROSS MUCH OF THE REGION. IF IT WAS NOT FOR THE THICK
SNOWPACK...TEMPS THIS AFTN MAY HAVE MIRRORED WHAT IS BEING
EXPERIENCED ACROSS PORTIONS OF MISSOURI THAT HAVE SOARED INTO THE
50S/60S. EITHER WAY...THE 40S WILL LIKELY FEEL BALMY CONSIDERING
WHERE TEMPS HAVE BEEN OVER THE PAST SEVERAL WEEKS. FULL SUNSHINE
WILL PERSIST AS BROAD SFC RIDGING PROVIDES MINIMAL CLOUDS ACROSS THE
REGION. SOUTHERLY FLOW WILL PERSIST THROUGH THE NEXT COUPLED OF
DAYS...HOWEVER A BRIEF LULL AS A WEAK FRONTAL BOUNDARY APPROACHES
THE FORECAST AREA THIS EVENING FROM THE NORTHWEST. CURRENT ANALYSIS
HAS THE BOUNDARY STRETCHING FROM COPPER HARBOR IN THE UPPER
PENINSULA OF MI...MEANDERING SOUTHWEST THROUGH CENTRAL IOWA. VISIBLE
IMAGERY SHOWS SOME CLOUDS ASSOCIATED WITH THIS FEATURE...HOWEVER NO
PRECIP IS CURRENTLY DEPICTED. SOME OF THE HI-RES GUIDANCE CONTINUE
TO HINT AT PERHAPS SOME SPRINKLES. AT THIS TIME VERY LOW CONFIDENCE
THAT ANY PRECIP WILL DEVELOP OVER THE FORECAST AREA...SO HAVE HELD
ONTO THE DRY FORECAST THIS EVENING.
BEHIND THE BOUNDARY...BROAD SFC RIDGING OVER THE CENTRAL PLAINS WILL
PUSH EAST. THIS WILL ALLOW FLOW TO TURN MORE WESTERLY FOR
WED...EVENTUALLY TURNING SOUTHWESTERLY AS THE FLOW REMAINS
PROGRESSIVE AND THE RIDGE EXITS THE STAGE FOR THE EAST COAST WED
NGT. DESPITE YET ANOTHER DAY OF FULL SUNSHINE WED...THE LGT WESTERLY
FLOW WILL LIKELY KEEP TEMPS SOMEWHAT IN CHECK. ALTHOUGH HAVE NUDGED
TEMPS A DEGREE OR TWO WARMER TO HOVER ARND 40 FOR MOST PLACES. THEN
THE FOCUS TURNS TOWARDS THE LATE WED NGT INTO THUR TIMEFRAME...AND
WHAT CONTINUES TO LOOK VERY CONCERNING FOR FLOODING/CONVECTION.
CONFIDENCE TONIGHT THROUGH WEDNESDAY...HIGH.
THURSDAY...
MID-LVL RIDGE WILL SLIDE OVERHEAD WED EVENING...WITH A THERMAL RIDGE
STEADILY LIFTING OVERHEAD AS WELL. TEMPS ALOFT SHUD PUSH ABOVE 0C BY
3Z THUR...THEN CONTINUE TO WARM. THIS PRESENT A SIGNIFICANT
CHALLENGE...AS A LLVL INVERSION WILL DEVELOP WITH SFC TEMPS COOLING
JUST AFTER SUNSET WED NGT TO THE UPR 20S/ARND 30. BUT WITH THE
STEADY SOUTHERLY FLOW LIFTING OVERHEAD...AND PRECIP LOOKING TO BE
DELAYED A LITTLE...THE ONSET OF PRECIP MAY ACTUALLY FALL AS LIQUID
RAIN RATHER THAN FREEZING RAIN. SOUNDINGS CONTINUE TO SUGGEST A 6HR
WINDOW OF FZRA AND HAVE MAINTAINED THIS IN THE FORECAST...BUT WITH
WARM/MOIST AIR LIFTING NORTH FROM RETURN FLOW OFF OF THE DEPARTING
SFC RIDGE OVER THE SOUTHEAST...PWAT VALUES ARE PROGGED TO BE
HOVERING ARND 1"...WHICH IS ROUGHLY 4 SIGMA ABOVE NORMAL. THE LATEST
HI-RES LCL WRF INDICATES ONSET OF MOISTURE/PRECIP DOES NOT ARRIVE
UNTIL CLOSER TO DAYBREAK THUR.
EXPECT THE SNOWPACK AT THE ONSET TO ABSORB SOME OF THE LIQUID THAT
FALLS INTO IT...HOWEVER WITH DEW POINTS POISED TO RISE ABOVE
FREEZING DURING THE DAY THIS SHOULD UNFORTUNATELY PROVIDE AN
EFFICIENT MEANS FOR THE SNOWPACK TO BEGIN MELTING AT A FAST RATE.
500MB TROUGH AXIS WILL BE SLOW TO EJECT EAST OF THE ROCKIES EARLY
THUR...AS THE SFC WAVE DEVELOPS. GUIDANCE CONTINUES TO SUGGEST A
SECONDARY WEAKER LOW WILL DEVELOP OVER THE NORTHERN PLAINS...HOWEVER
THE TWO WILL CONSOLIDATE INTO A STRONGER SFC WAVE OVER CHICAGO THUR
AFTN/EVE...AS THE DRY SLOT QUICKLY LIFTS NORTHEAST TOWARDS THE
FORECAST AREA.
THERE REMAINS STRONG ASCENT AHEAD OF THE LOW...WITH CONSIDERABLE
LLVL SHEAR IN THE LOWEST 0-3KM AGL THUR. WITH MIDLVL CAPE PROGGED
ARND 300-400J/KG...HAVE MAINTAINED THE MENTION OF THUNDER...AND IT
IS CONCEIVABLE THAT SOME OF THE STORMS COULD BECOME STRONG. SPC HAS
CONTINUED THE SLIGHT RISK FOR SEVERE WEATHER THUR...MAINLY ALONG AND
EAST OF A PONTIAC TO GARY LINE. THE MAIN THREAT FROM THUNDERSTORMS
LOOKS TO BE WIND...HOWEVER GIVEN HOW LOW THE FREEZING LEVEL WILL
BE...AND WITH THE SHEAR IN THE LLVLS...IT IS POSSIBLE FOR AN
ISOLATED TORNADO. TO FURTHER COMPLICATE THE FORECAST THUR...THE
MELTING SNOWPACK WILL LIKELY RESULT IN AREAS OF FOG. TEMPS THUR
REMAIN A CHALLENGE...HOWEVER GUIDANCE HAS BECOME SOMEWHAT MORE
CONSISTENT WITH A WARMER SOLUTION PRODUCING MID/UPR 40S OVER THE
FORECAST AREA...AND PERHAPS THE LOW 50S SOUTH OF LASALLE TO KANKAKEE
TO VALPO.
CONFIDENCE...HIGH.
FRIDAY THROUGH EARLY NEXT WEEK...
MID-LVL TROUGH AXIS CONTINUES TO SLIDE EAST INTO THE PLAINS THUR
NGT...ARRIVING OVER THE GREAT LAKES REGION EARLY FRI. SFC LOW WILL
BE WRAPPING UP OVER LAKE MICHIGAN...WITH A DRY WEDGE LIFTING ACROSS
THE FORECAST AREA LATE THUR NGT. THIS SHOULD BRING AN END TO THE
HEAVY/STEADY RAIN/THUNDER THUR AFTN...WITH TEMPS COOLING BEHIND A
FRONTAL BOUNDARY AND POSSIBLY BECOMING MIXED WITH SNOW.
THEN FOR THE UPCOMING WEEKEND TEMPS TREND BACK TOWARDS WHAT HAS BEEN
THE PATTERN ALL WINTER...BROAD TROUGHING OVER THE GREAT LAKES. TEMPS
FALL BACK INTO THE 20S FOR THE WEEKEND THROUGH EARLY NEXT
WEEK...WITH A FEW WEAK MID-LVL WAVES FLOATING OVER THE REGION AND
POSSIBLY BRINGING SOME LIGHT SNOW.
CONFIDENCE...HIGH.
BEACHLER
&&
.HYDROLOGY...
MODELS CONTINUE TO TREND TOWARD A STRONGER SYSTEM THURSDAY WITH
RESULTANT MORE SIGNIFICANT SURGE OF WARM AIR AND HIGH DEWPOINTS.
ABOUT THE ONLY SAVING GRACE LOOKS TO BE A RELATIVELY SHORT TIME
PERIOD WITH DEWPOINTS ABOVE 40F...ESPECIALLY NORTHWEST CWA...BUT
STILL THE HIGH DEWPOINTS SHOULD RESULT IN QUITE A BIT OF SNOW MELT
ADDING TO THE RUNOFF OF THE POTENTIALLY MODERATE TO HEAVY
RAINFALL. THE BOTH WILL RESULT IN A QUICK INCREASE IN STREAM FLOW
AND A ELEVATED THREAT OF ICE JAM FLOODING AS MASSIVE AMOUNTS OF
ICE ARE DISLODGED DUE TO THE INCREASED STREAM FLOW. WILL LIKELY
NEED A FLOOD WATCH FOR THIS TIME PERIOD...BUT IN THE MEANTIME WILL
GIVE A QUICK FRESHENING UP TO THE ESF.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* GUSTY SOUTHWEST WIND ENDING THIS EVENING AND BECOMING WEST BEHIND
A COLD FRONT.
* POTENTIAL FOR IFR-MVFR STRATUS TO DEVELOP TONIGHT.
DZ
//DISCUSSION...UPDATED 00Z...
LOW LEVEL WIND STARTING TO EASE AHEAD OF COLD FRONT OVER EASTERN IA.
AMDAR AND RAP DATA INDICATE LOW LEVEL MAX WIND FIELD TO CONTINUE TO
TRANSITION EAST AND OUT OF TERMINAL AREA BY MID EVENING.
FORECAST MODEL RUNS CONTINUE TO INDICATE THE POTENTIAL FOR A THIN
LOW LEVEL CLOUD DECK TO DEVELOP ABOVE THE MELTING SNOW PACK
FOLLOWING DRY FRONTAL PASSAGE.
PROGRESSIVE PATTERN TO PERSIST AS HIGH PRESSURE TO MOVE OVER INTO
WEDNESDAY AND WILL HOLD WIND SPEEDS DOWN.
DZ
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN WIND DIRECTION...MEDIUM CONFIDENCE IN SPEED.
* LOW CONFIDENCE IN MVFR-IFR STRATUS DVLPMT OVERNIGHT.
DZ
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...FZRA LIKELY AND A CHC OF TSRA EARLY THEN RA WITH A
CHANCE OF TSRA. CHC LGT SHRA OR SHSN LATE.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
&&
.MARINE...
225 PM CST
WILL LEAVE THE SMALL CRAFT ADVISORY AS IS.
LOW PRESSURE IS OVER WESTERN ONTARIO AND ITS COLD FRONT WILL PASS
OVER THE LAKE TONIGHT. WINDS WILL TURN WEST BEHIND THE FRONT. A
WEAK SURFACE RIDGE PASSES OVER THE LAKE TOMORROW WITH WINDS TURNING
SOUTH BEHIND IT TOMORROW NIGHT. THE NEXT LOW PRESSURE SYSTEM IS THE
BIG CONCERN. TWO LOWS COMBINE OVER THE SOUTHERN END OF THE LAKE
THURSDAY AFTERNOON. GUIDANCE SHOWS A HIGH LEVEL OF AGREEMENT WITH
THIS LOW...INCLUDING IT DEEPENING AS IT MOVES NORTH UP THE LAKE
THROUGH FRIDAY.
AS SUCH GALES ARE EXPECTED LATE THURSDAY THROUGH FRIDAY. WINDS WILL
VARY ACROSS THE LAKE WITH SOUTH WINDS OVER THE SOUTH HALF AND EAST
OVER THE NORTH HALF. WINDS BECOME SOUTHWEST ACROSS THE LAKE
THURSDAY NIGHT AND INCREASE TO HIGH END GALES...TO 45 KT. THE HIGH
END OF GUIDANCE SUGGESTED STORM FORCE WINDS...BUT WILL CAP WINDS AT
HIGH END GALES FOR NOW. WINDS FINALLY BEGIN TO SUBSIDE FRIDAY
MORNING AS THE LOW CONTINUES TO PULL AWAY. HOWEVER...THE LOW
REMAINS OVER EASTERN ONTARIO THROUGH SUNDAY...SO WINDS WILL BE WEST
ACROSS THE LAKE THROUGH SUNDAY AS WELL.
THIS FAR OUT...WILL NOT ISSUE A GALE RELATED PRODUCT...BUT ONE WILL
BE NEEDED FOR THURSDAY AND FRIDAY. GALE FORCE GUSTS ARE LIKELY IN
THE NEARSHORE WATERS AS WELL.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
759 PM CST TUE FEB 18 2014
.DISCUSSION...
759 PM CST
ONLY MINOR TWEAKS TO NEAR TERM OF FORECAST THIS EVENING...MAINLY TO
BUMP OVERNIGHT MIN TEMPS UP JUST A BIT. FARTHER OUT...HAVE HIT
HARDER AT THE POTENTIAL FOR VERY WINDY CONDITIONS THURSDAY NIGHT
INTO FRIDAY BEHIND DEPARTING DEEPENING LOW PRESSURE SYSTEM.
TEMPS STILL IN THE MID 30S TO LOW 40S IN SOME SPOTS ACROSS THE
FORECAST AREA THIS EVENING...IN SOUTH FLOW AHEAD OF A COLD FRONT
WHICH WAS JUST ENTERING NORTHWEST IL AT 01Z. COLD FRONT WILL
CONTINUE TO PUSH EAST THROUGH THE REMAINDER OF THE EVENING AND EARLY
OVERNIGHT HOURS WITH A WIND SHIFT TO THE WEST BEHIND THE BOUNDARY.
HOWEVER...FRONT IS OF PACIFIC ORIGIN AND TEMPS CURRENTLY NOT FALLING
OFF TOO MUCH BEHIND IT WITH READINGS IN THE MID/UPPER 30S STILL
ACROSS IA. HAD ADJUSTED HOURLY TEMP GRIDS FOR A MUCH SLOWER FALL
EARLIER AND HAVE BUMPED OVERNIGHT MINS A BIT INTO THE 25-30 DEGREE
RANGE FOR MOST AREAS AND THIS MIGHT EVEN BE A DEGREE OR TWO TOO COOL
COME MORNING. OTHERWISE...PATCHY MID/HIGH CLOUDS OVERNIGHT WITH
UPPER TROUGH PROPAGATING ACROSS THE REGION. ANY LINGERING CLOUDS
SHOULD QUICKLY CLEAR EARLY WEDNESDAY MORNING AS TROUGH MOVES EAST
AND SFC RIDGE BUILDS IN FROM THE WEST.
FARTHER OUT...IN ADDITION TO THE CHALLENGES OF PRECIP TYPE/RAIN
AMOUNTS AND THUNDER POTENTIAL THURSDAY...IT ALSO APPEARS THAT VERY
WINDY SYNOPTIC CONDITIONS WILL DEVELOP LATE THURSDAY AND PERSIST
THROUGH THE NIGHT INTO EARLY FRIDAY. GUIDANCE IN GOOD AGREEMENT IN
DEVELOPING 993-ISH MB LOW INTO WESTERN IL BY 18Z THURSDAY...AND
RAPIDLY DEEPENING IT TO NEAR 885 MB AS IT LIFTS INTO EASTERN WI BY
EVENING AND TO NEAR 980 MB OVER THE UPPER PENINSULA OF MICH BY
MIDNIGHT. RESULTING ISALLOBARIC RISE/FALL COUPLET AND WIND RESPONSE
ARE EQUALLY IMPRESSIVE...WITH FORECAST SOUNDINGS INDICATING THE
POTENTIAL FOR WEST WINDS TO GUST 40 TO 50+ MPH BEHIND THE DEEPENING
LOW THURSDAY EVENING. SLOW DIMINISHING TREND THEN LASTS INTO FRIDAY.
HAVE BUMPED WIND GUSTS THROUGH THE THURSDAY NIGHT/FRIDAY PERIOD
BASED ON THESE SOLID MODEL TRENDS/INDICATIONS AND WILL HIGHLIGHT IN
UPDATED HWO.
RATZER
&&
.PREV DISCUSSION...
303 PM CST
TONIGHT THROUGH WEDNESDAY...
THE HEAT SOURCE HAS BEEN FOUND...WITH TEMPS SOARING INTO THE 40S
TODAY ACROSS MUCH OF THE REGION. IF IT WAS NOT FOR THE THICK
SNOWPACK...TEMPS THIS AFTN MAY HAVE MIRRORED WHAT IS BEING
EXPERIENCED ACROSS PORTIONS OF MISSOURI THAT HAVE SOARED INTO THE
50S/60S. EITHER WAY...THE 40S WILL LIKELY FEEL BALMY CONSIDERING
WHERE TEMPS HAVE BEEN OVER THE PAST SEVERAL WEEKS. FULL SUNSHINE
WILL PERSIST AS BROAD SFC RIDGING PROVIDES MINIMAL CLOUDS ACROSS THE
REGION. SOUTHERLY FLOW WILL PERSIST THROUGH THE NEXT COUPLED OF
DAYS...HOWEVER A BRIEF LULL AS A WEAK FRONTAL BOUNDARY APPROACHES
THE FORECAST AREA THIS EVENING FROM THE NORTHWEST. CURRENT ANALYSIS
HAS THE BOUNDARY STRETCHING FROM COPPER HARBOR IN THE UPPER
PENINSULA OF MI...MEANDERING SOUTHWEST THROUGH CENTRAL IOWA. VISIBLE
IMAGERY SHOWS SOME CLOUDS ASSOCIATED WITH THIS FEATURE...HOWEVER NO
PRECIP IS CURRENTLY DEPICTED. SOME OF THE HI-RES GUIDANCE CONTINUE
TO HINT AT PERHAPS SOME SPRINKLES. AT THIS TIME VERY LOW CONFIDENCE
THAT ANY PRECIP WILL DEVELOP OVER THE FORECAST AREA...SO HAVE HELD
ONTO THE DRY FORECAST THIS EVENING.
BEHIND THE BOUNDARY...BROAD SFC RIDGING OVER THE CENTRAL PLAINS WILL
PUSH EAST. THIS WILL ALLOW FLOW TO TURN MORE WESTERLY FOR
WED...EVENTUALLY TURNING SOUTHWESTERLY AS THE FLOW REMAINS
PROGRESSIVE AND THE RIDGE EXITS THE STAGE FOR THE EAST COAST WED
NGT. DESPITE YET ANOTHER DAY OF FULL SUNSHINE WED...THE LGT WESTERLY
FLOW WILL LIKELY KEEP TEMPS SOMEWHAT IN CHECK. ALTHOUGH HAVE NUDGED
TEMPS A DEGREE OR TWO WARMER TO HOVER ARND 40 FOR MOST PLACES. THEN
THE FOCUS TURNS TOWARDS THE LATE WED NGT INTO THUR TIMEFRAME...AND
WHAT CONTINUES TO LOOK VERY CONCERNING FOR FLOODING/CONVECTION.
CONFIDENCE TONIGHT THROUGH WEDNESDAY...HIGH.
THURSDAY...
MID-LVL RIDGE WILL SLIDE OVERHEAD WED EVENING...WITH A THERMAL RIDGE
STEADILY LIFTING OVERHEAD AS WELL. TEMPS ALOFT SHUD PUSH ABOVE 0C BY
3Z THUR...THEN CONTINUE TO WARM. THIS PRESENT A SIGNIFICANT
CHALLENGE...AS A LLVL INVERSION WILL DEVELOP WITH SFC TEMPS COOLING
JUST AFTER SUNSET WED NGT TO THE UPR 20S/ARND 30. BUT WITH THE
STEADY SOUTHERLY FLOW LIFTING OVERHEAD...AND PRECIP LOOKING TO BE
DELAYED A LITTLE...THE ONSET OF PRECIP MAY ACTUALLY FALL AS LIQUID
RAIN RATHER THAN FREEZING RAIN. SOUNDINGS CONTINUE TO SUGGEST A 6HR
WINDOW OF FZRA AND HAVE MAINTAINED THIS IN THE FORECAST...BUT WITH
WARM/MOIST AIR LIFTING NORTH FROM RETURN FLOW OFF OF THE DEPARTING
SFC RIDGE OVER THE SOUTHEAST...PWAT VALUES ARE PROGGED TO BE
HOVERING ARND 1"...WHICH IS ROUGHLY 4 SIGMA ABOVE NORMAL. THE LATEST
HI-RES LCL WRF INDICATES ONSET OF MOISTURE/PRECIP DOES NOT ARRIVE
UNTIL CLOSER TO DAYBREAK THUR.
EXPECT THE SNOWPACK AT THE ONSET TO ABSORB SOME OF THE LIQUID THAT
FALLS INTO IT...HOWEVER WITH DEW POINTS POISED TO RISE ABOVE
FREEZING DURING THE DAY THIS SHOULD UNFORTUNATELY PROVIDE AN
EFFICIENT MEANS FOR THE SNOWPACK TO BEGIN MELTING AT A FAST RATE.
500MB TROUGH AXIS WILL BE SLOW TO EJECT EAST OF THE ROCKIES EARLY
THUR...AS THE SFC WAVE DEVELOPS. GUIDANCE CONTINUES TO SUGGEST A
SECONDARY WEAKER LOW WILL DEVELOP OVER THE NORTHERN PLAINS...HOWEVER
THE TWO WILL CONSOLIDATE INTO A STRONGER SFC WAVE OVER CHICAGO THUR
AFTN/EVE...AS THE DRY SLOT QUICKLY LIFTS NORTHEAST TOWARDS THE
FORECAST AREA.
THERE REMAINS STRONG ASCENT AHEAD OF THE LOW...WITH CONSIDERABLE
LLVL SHEAR IN THE LOWEST 0-3KM AGL THUR. WITH MIDLVL CAPE PROGGED
ARND 300-400J/KG...HAVE MAINTAINED THE MENTION OF THUNDER...AND IT
IS CONCEIVABLE THAT SOME OF THE STORMS COULD BECOME STRONG. SPC HAS
CONTINUED THE SLIGHT RISK FOR SEVERE WEATHER THUR...MAINLY ALONG AND
EAST OF A PONTIAC TO GARY LINE. THE MAIN THREAT FROM THUNDERSTORMS
LOOKS TO BE WIND...HOWEVER GIVEN HOW LOW THE FREEZING LEVEL WILL
BE...AND WITH THE SHEAR IN THE LLVLS...IT IS POSSIBLE FOR AN
ISOLATED TORNADO. TO FURTHER COMPLICATE THE FORECAST THUR...THE
MELTING SNOWPACK WILL LIKELY RESULT IN AREAS OF FOG. TEMPS THUR
REMAIN A CHALLENGE...HOWEVER GUIDANCE HAS BECOME SOMEWHAT MORE
CONSISTENT WITH A WARMER SOLUTION PRODUCING MID/UPR 40S OVER THE
FORECAST AREA...AND PERHAPS THE LOW 50S SOUTH OF LASALLE TO KANKAKEE
TO VALPO.
CONFIDENCE...HIGH.
FRIDAY THROUGH EARLY NEXT WEEK...
MID-LVL TROUGH AXIS CONTINUES TO SLIDE EAST INTO THE PLAINS THUR
NGT...ARRIVING OVER THE GREAT LAKES REGION EARLY FRI. SFC LOW WILL
BE WRAPPING UP OVER LAKE MICHIGAN...WITH A DRY WEDGE LIFTING ACROSS
THE FORECAST AREA LATE THUR NGT. THIS SHOULD BRING AN END TO THE
HEAVY/STEADY RAIN/THUNDER THUR AFTN...WITH TEMPS COOLING BEHIND A
FRONTAL BOUNDARY AND POSSIBLY BECOMING MIXED WITH SNOW.
THEN FOR THE UPCOMING WEEKEND TEMPS TREND BACK TOWARDS WHAT HAS BEEN
THE PATTERN ALL WINTER...BROAD TROUGHING OVER THE GREAT LAKES. TEMPS
FALL BACK INTO THE 20S FOR THE WEEKEND THROUGH EARLY NEXT
WEEK...WITH A FEW WEAK MID-LVL WAVES FLOATING OVER THE REGION AND
POSSIBLY BRINGING SOME LIGHT SNOW.
CONFIDENCE...HIGH.
BEACHLER
&&
.HYDROLOGY...
MODELS CONTINUE TO TREND TOWARD A STRONGER SYSTEM THURSDAY WITH
RESULTANT MORE SIGNIFICANT SURGE OF WARM AIR AND HIGH DEWPOINTS.
ABOUT THE ONLY SAVING GRACE LOOKS TO BE A RELATIVELY SHORT TIME
PERIOD WITH DEWPOINTS ABOVE 40F...ESPECIALLY NORTHWEST CWA...BUT
STILL THE HIGH DEWPOINTS SHOULD RESULT IN QUITE A BIT OF SNOW MELT
ADDING TO THE RUNOFF OF THE POTENTIALLY MODERATE TO HEAVY
RAINFALL. THE BOTH WILL RESULT IN A QUICK INCREASE IN STREAM FLOW
AND A ELEVATED THREAT OF ICE JAM FLOODING AS MASSIVE AMOUNTS OF
ICE ARE DISLODGED DUE TO THE INCREASED STREAM FLOW. WILL LIKELY
NEED A FLOOD WATCH FOR THIS TIME PERIOD...BUT IN THE MEANTIME WILL
GIVE A QUICK FRESHENING UP TO THE ESF.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* GUSTY SOUTHWEST WIND ENDING THIS EVENING AND BECOMING WEST BEHIND
A COLD FRONT.
* POTENTIAL FOR IFR-MVFR STRATUS TO DEVELOP TONIGHT.
DZ
//DISCUSSION...UPDATED 00Z...
LOW LEVEL WIND STARTING TO EASE AHEAD OF COLD FRONT OVER EASTERN IA.
AMDAR AND RAP DATA INDICATE LOW LEVEL MAX WIND FIELD TO CONTINUE TO
TRANSITION EAST AND OUT OF TERMINAL AREA BY MID EVENING.
FORECAST MODEL RUNS CONTINUE TO INDICATE THE POTENTIAL FOR A THIN
LOW LEVEL CLOUD DECK TO DEVELOP ABOVE THE MELTING SNOW PACK
FOLLOWING DRY FRONTAL PASSAGE.
PROGRESSIVE PATTERN TO PERSIST AS HIGH PRESSURE TO MOVE OVER INTO
WEDNESDAY AND WILL HOLD WIND SPEEDS DOWN.
DZ
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN WIND DIRECTION...MEDIUM CONFIDENCE IN SPEED.
* LOW CONFIDENCE IN MVFR-IFR STRATUS DVLPMT OVERNIGHT.
DZ
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...FZRA LIKELY AND A CHC OF TSRA EARLY THEN RA WITH A
CHANCE OF TSRA. CHC LGT SHRA OR SHSN LATE.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
&&
.MARINE...
225 PM CST
WILL LEAVE THE SMALL CRAFT ADVISORY AS IS.
LOW PRESSURE IS OVER WESTERN ONTARIO AND ITS COLD FRONT WILL PASS
OVER THE LAKE TONIGHT. WINDS WILL TURN WEST BEHIND THE FRONT. A
WEAK SURFACE RIDGE PASSES OVER THE LAKE TOMORROW WITH WINDS TURNING
SOUTH BEHIND IT TOMORROW NIGHT. THE NEXT LOW PRESSURE SYSTEM IS THE
BIG CONCERN. TWO LOWS COMBINE OVER THE SOUTHERN END OF THE LAKE
THURSDAY AFTERNOON. GUIDANCE SHOWS A HIGH LEVEL OF AGREEMENT WITH
THIS LOW...INCLUDING IT DEEPENING AS IT MOVES NORTH UP THE LAKE
THROUGH FRIDAY.
AS SUCH GALES ARE EXPECTED LATE THURSDAY THROUGH FRIDAY. WINDS WILL
VARY ACROSS THE LAKE WITH SOUTH WINDS OVER THE SOUTH HALF AND EAST
OVER THE NORTH HALF. WINDS BECOME SOUTHWEST ACROSS THE LAKE
THURSDAY NIGHT AND INCREASE TO HIGH END GALES...TO 45 KT. THE HIGH
END OF GUIDANCE SUGGESTED STORM FORCE WINDS...BUT WILL CAP WINDS AT
HIGH END GALES FOR NOW. WINDS FINALLY BEGIN TO SUBSIDE FRIDAY
MORNING AS THE LOW CONTINUES TO PULL AWAY. HOWEVER...THE LOW
REMAINS OVER EASTERN ONTARIO THROUGH SUNDAY...SO WINDS WILL BE WEST
ACROSS THE LAKE THROUGH SUNDAY AS WELL.
THIS FAR OUT...WILL NOT ISSUE A GALE RELATED PRODUCT...BUT ONE WILL
BE NEEDED FOR THURSDAY AND FRIDAY. GALE FORCE GUSTS ARE LIKELY IN
THE NEARSHORE WATERS AS WELL.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
633 PM CST TUE FEB 18 2014
.DISCUSSION...
303 PM CST
TONIGHT THROUGH WEDNESDAY...
THE HEAT SOURCE HAS BEEN FOUND...WITH TEMPS SOARING INTO THE 40S
TODAY ACROSS MUCH OF THE REGION. IF IT WAS NOT FOR THE THICK
SNOWPACK...TEMPS THIS AFTN MAY HAVE MIRRORED WHAT IS BEING
EXPERIENCED ACROSS PORTIONS OF MISSOURI THAT HAVE SOARED INTO THE
50S/60S. EITHER WAY...THE 40S WILL LIKELY FEEL BALMY CONSIDERING
WHERE TEMPS HAVE BEEN OVER THE PAST SEVERAL WEEKS. FULL SUNSHINE
WILL PERSIST AS BROAD SFC RIDGING PROVIDES MINIMAL CLOUDS ACROSS THE
REGION. SOUTHERLY FLOW WILL PERSIST THROUGH THE NEXT COUPLED OF
DAYS...HOWEVER A BRIEF LULL AS A WEAK FRONTAL BOUNDARY APPROACHES
THE FORECAST AREA THIS EVENING FROM THE NORTHWEST. CURRENT ANALYSIS
HAS THE BOUNDARY STRETCHING FROM COPPER HARBOR IN THE UPPER
PENINSULA OF MI...MEANDERING SOUTHWEST THROUGH CENTRAL IOWA. VISIBLE
IMAGERY SHOWS SOME CLOUDS ASSOCIATED WITH THIS FEATURE...HOWEVER NO
PRECIP IS CURRENTLY DEPICTED. SOME OF THE HI-RES GUIDANCE CONTINUE
TO HINT AT PERHAPS SOME SPRINKLES. AT THIS TIME VERY LOW CONFIDENCE
THAT ANY PRECIP WILL DEVELOP OVER THE FORECAST AREA...SO HAVE HELD
ONTO THE DRY FORECAST THIS EVENING.
BEHIND THE BOUNDARY...BROAD SFC RIDGING OVER THE CENTRAL PLAINS WILL
PUSH EAST. THIS WILL ALLOW FLOW TO TURN MORE WESTERLY FOR
WED...EVENTUALLY TURNING SOUTHWESTERLY AS THE FLOW REMAINS
PROGRESSIVE AND THE RIDGE EXITS THE STAGE FOR THE EAST COAST WED
NGT. DESPITE YET ANOTHER DAY OF FULL SUNSHINE WED...THE LGT WESTERLY
FLOW WILL LIKELY KEEP TEMPS SOMEWHAT IN CHECK. ALTHOUGH HAVE NUDGED
TEMPS A DEGREE OR TWO WARMER TO HOVER ARND 40 FOR MOST PLACES. THEN
THE FOCUS TURNS TOWARDS THE LATE WED NGT INTO THUR TIMEFRAME...AND
WHAT CONTINUES TO LOOK VERY CONCERNING FOR FLOODING/CONVECTION.
CONFIDENCE TONIGHT THROUGH WEDNESDAY...HIGH.
THURSDAY...
MID-LVL RIDGE WILL SLIDE OVERHEAD WED EVENING...WITH A THERMAL RIDGE
STEADILY LIFTING OVERHEAD AS WELL. TEMPS ALOFT SHUD PUSH ABOVE 0C BY
3Z THUR...THEN CONTINUE TO WARM. THIS PRESENT A SIGNIFICANT
CHALLENGE...AS A LLVL INVERSION WILL DEVELOP WITH SFC TEMPS COOLING
JUST AFTER SUNSET WED NGT TO THE UPR 20S/ARND 30. BUT WITH THE
STEADY SOUTHERLY FLOW LIFTING OVERHEAD...AND PRECIP LOOKING TO BE
DELAYED A LITTLE...THE ONSET OF PRECIP MAY ACTUALLY FALL AS LIQUID
RAIN RATHER THAN FREEZING RAIN. SOUNDINGS CONTINUE TO SUGGEST A 6HR
WINDOW OF FZRA AND HAVE MAINTAINED THIS IN THE FORECAST...BUT WITH
WARM/MOIST AIR LIFTING NORTH FROM RETURN FLOW OFF OF THE DEPARTING
SFC RIDGE OVER THE SOUTHEAST...PWAT VALUES ARE PROGGED TO BE
HOVERING ARND 1"...WHICH IS ROUGHLY 4 SIGMA ABOVE NORMAL. THE LATEST
HI-RES LCL WRF INDICATES ONSET OF MOISTURE/PRECIP DOES NOT ARRIVE
UNTIL CLOSER TO DAYBREAK THUR.
EXPECT THE SNOWPACK AT THE ONSET TO ABSORB SOME OF THE LIQUID THAT
FALLS INTO IT...HOWEVER WITH DEW POINTS POISED TO RISE ABOVE
FREEZING DURING THE DAY THIS SHOULD UNFORTUNATELY PROVIDE AN
EFFICIENT MEANS FOR THE SNOWPACK TO BEGIN MELTING AT A FAST RATE.
500MB TROUGH AXIS WILL BE SLOW TO EJECT EAST OF THE ROCKIES EARLY
THUR...AS THE SFC WAVE DEVELOPS. GUIDANCE CONTINUES TO SUGGEST A
SECONDARY WEAKER LOW WILL DEVELOP OVER THE NORTHERN PLAINS...HOWEVER
THE TWO WILL CONSOLIDATE INTO A STRONGER SFC WAVE OVER CHICAGO THUR
AFTN/EVE...AS THE DRY SLOT QUICKLY LIFTS NORTHEAST TOWARDS THE
FORECAST AREA.
THERE REMAINS STRONG ASCENT AHEAD OF THE LOW...WITH CONSIDERABLE
LLVL SHEAR IN THE LOWEST 0-3KM AGL THUR. WITH MIDLVL CAPE PROGGED
ARND 300-400J/KG...HAVE MAINTAINED THE MENTION OF THUNDER...AND IT
IS CONCEIVABLE THAT SOME OF THE STORMS COULD BECOME STRONG. SPC HAS
CONTINUED THE SLIGHT RISK FOR SEVERE WEATHER THUR...MAINLY ALONG AND
EAST OF A PONTIAC TO GARY LINE. THE MAIN THREAT FROM THUNDERSTORMS
LOOKS TO BE WIND...HOWEVER GIVEN HOW LOW THE FREEZING LEVEL WILL
BE...AND WITH THE SHEAR IN THE LLVLS...IT IS POSSIBLE FOR AN
ISOLATED TORNADO. TO FURTHER COMPLICATE THE FORECAST THUR...THE
MELTING SNOWPACK WILL LIKELY RESULT IN AREAS OF FOG. TEMPS THUR
REMAIN A CHALLENGE...HOWEVER GUIDANCE HAS BECOME SOMEWHAT MORE
CONSISTENT WITH A WARMER SOLUTION PRODUCING MID/UPR 40S OVER THE
FORECAST AREA...AND PERHAPS THE LOW 50S SOUTH OF LASALLE TO KANKAKEE
TO VALPO.
CONFIDENCE...HIGH.
FRIDAY THROUGH EARLY NEXT WEEK...
MID-LVL TROUGH AXIS CONTINUES TO SLIDE EAST INTO THE PLAINS THUR
NGT...ARRIVING OVER THE GREAT LAKES REGION EARLY FRI. SFC LOW WILL
BE WRAPPING UP OVER LAKE MICHIGAN...WITH A DRY WEDGE LIFTING ACROSS
THE FORECAST AREA LATE THUR NGT. THIS SHOULD BRING AN END TO THE
HEAVY/STEADY RAIN/THUNDER THUR AFTN...WITH TEMPS COOLING BEHIND A
FRONTAL BOUNDARY AND POSSIBLY BECOMING MIXED WITH SNOW.
THEN FOR THE UPCOMING WEEKEND TEMPS TREND BACK TOWARDS WHAT HAS BEEN
THE PATTERN ALL WINTER...BROAD TROUGHING OVER THE GREAT LAKES. TEMPS
FALL BACK INTO THE 20S FOR THE WEEKEND THROUGH EARLY NEXT
WEEK...WITH A FEW WEAK MID-LVL WAVES FLOATING OVER THE REGION AND
POSSIBLY BRINGING SOME LIGHT SNOW.
CONFIDENCE...HIGH.
BEACHLER
&&
.HYDROLOGY...
MODELS CONTINUE TO TREND TOWARD A STRONGER SYSTEM THURSDAY WITH
RESULTANT MORE SIGNIFICANT SURGE OF WARM AIR AND HIGH DEWPOINTS.
ABOUT THE ONLY SAVING GRACE LOOKS TO BE A RELATIVELY SHORT TIME
PERIOD WITH DEWPOINTS ABOVE 40F...ESPECIALLY NORTHWEST CWA...BUT
STILL THE HIGH DEWPOINTS SHOULD RESULT IN QUITE A BIT OF SNOW MELT
ADDING TO THE RUNOFF OF THE POTENTIALLY MODERATE TO HEAVY
RAINFALL. THE BOTH WILL RESULT IN A QUICK INCREASE IN STREAM FLOW
AND A ELEVATED THREAT OF ICE JAM FLOODING AS MASSIVE AMOUNTS OF
ICE ARE DISLODGED DUE TO THE INCREASED STREAM FLOW. WILL LIKELY
NEED A FLOOD WATCH FOR THIS TIME PERIOD...BUT IN THE MEANTIME WILL
GIVE A QUICK FRESHENING UP TO THE ESF.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* GUSTY SOUTHWEST WIND ENDING THIS EVENING AND BECOMING WEST BEHIND
A COLD FRONT.
* POTENTIAL FOR IFR-MVFR STRATUS TO DEVELOP TONIGHT.
DZ
//DISCUSSION...UPDATED 00Z...
LOW LEVEL WIND STARTING TO EASE AHEAD OF COLD FRONT OVER EASTERN IA.
AMDAR AND RAP DATA INDICATE LOW LEVEL MAX WIND FIELD TO CONTINUE TO
TRANSITION EAST AND OUT OF TERMINAL AREA BY MID EVENING.
FORECAST MODEL RUNS CONTINUE TO INDICATE THE POTENTIAL FOR A THIN
LOW LEVEL CLOUD DECK TO DEVELOP ABOVE THE MELTING SNOW PACK
FOLLOWING DRY FRONTAL PASSAGE.
PROGRESSIVE PATTERN TO PERSIST AS HIGH PRESSURE TO MOVE OVER INTO
WEDNESDAY AND WILL HOLD WIND SPEEDS DOWN.
DZ
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN WIND DIRECTION...MEDIUM CONFIDENCE IN SPEED.
* LOW CONFIDENCE IN MVFR-IFR STRATUS DVLPMT OVERNIGHT.
DZ
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...FZRA LIKELY AND A CHC OF TSRA EARLY THEN RA WITH A
CHANCE OF TSRA. CHC LGT SHRA OR SHSN LATE.
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...VFR.
DZ
&&
.MARINE...
225 PM CST
WILL LEAVE THE SMALL CRAFT ADVISORY AS IS.
LOW PRESSURE IS OVER WESTERN ONTARIO AND ITS COLD FRONT WILL PASS
OVER THE LAKE TONIGHT. WINDS WILL TURN WEST BEHIND THE FRONT. A
WEAK SURFACE RIDGE PASSES OVER THE LAKE TOMORROW WITH WINDS TURNING
SOUTH BEHIND IT TOMORROW NIGHT. THE NEXT LOW PRESSURE SYSTEM IS THE
BIG CONCERN. TWO LOWS COMBINE OVER THE SOUTHERN END OF THE LAKE
THURSDAY AFTERNOON. GUIDANCE SHOWS A HIGH LEVEL OF AGREEMENT WITH
THIS LOW...INCLUDING IT DEEPENING AS IT MOVES NORTH UP THE LAKE
THROUGH FRIDAY.
AS SUCH GALES ARE EXPECTED LATE THURSDAY THROUGH FRIDAY. WINDS WILL
VARY ACROSS THE LAKE WITH SOUTH WINDS OVER THE SOUTH HALF AND EAST
OVER THE NORTH HALF. WINDS BECOME SOUTHWEST ACROSS THE LAKE
THURSDAY NIGHT AND INCREASE TO HIGH END GALES...TO 45 KT. THE HIGH
END OF GUIDANCE SUGGESTED STORM FORCE WINDS...BUT WILL CAP WINDS AT
HIGH END GALES FOR NOW. WINDS FINALLY BEGIN TO SUBSIDE FRIDAY
MORNING AS THE LOW CONTINUES TO PULL AWAY. HOWEVER...THE LOW
REMAINS OVER EASTERN ONTARIO THROUGH SUNDAY...SO WINDS WILL BE WEST
ACROSS THE LAKE THROUGH SUNDAY AS WELL.
THIS FAR OUT...WILL NOT ISSUE A GALE RELATED PRODUCT...BUT ONE WILL
BE NEEDED FOR THURSDAY AND FRIDAY. GALE FORCE GUSTS ARE LIKELY IN
THE NEARSHORE WATERS AS WELL.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
427 PM CST MON FEB 17 2014
.DISCUSSION...
248 PM CST
SHORT TERM...THROUGH TONIGHT...
WILL LEAVE THE WINTER STORM WARNING AS IS...WITH THE WESTERN
COUNTIES ENDING AT 6PM AND THE EASTERN COUNTIES ENDING AT 9PM CST.
TWO LOWS ARE OVER THE REGION. THE DEEPER ONE IS OVER SOUTHWEST MN
WHILE THE OTHER IS OVER SOUTHERN IL. BOTH LOWS HAVE DEEPENED IN
THE PAST HOUR. ALOFT...THERE IS AN UPPER LEVEL TROUGH FROM MN
THROUGH MO WITH A SLIGHT NEGATIVE TILT. THIS TROUGH IS PROVIDING THE
LIFT FOR THE SNOW. THE RAP HAS HAD A PRETTY GOOD IDEA OF THE FGEN
FORCING AND CAPE TODAY. THE FGEN IS FOCUSED JUST SOUTH OF THE CWA
AND HAVE IT PASSING FROM MCLEAN COUNTY INTO CENTRAL INDIANA LATE
THIS AFTERNOON AND THE CAPE REMAINS ON THE WARM SIDE OF THE FGEN
BAND. AS SUCH THINKING THUNDERSNOW WILL REMAIN CONFINED TO AREAS
SOUTH OF I-80 AND NORTHWEST INDIANA FOR THE NEXT COUPLE OF HOURS
BEFORE SHIFTING INTO INDIANA BY 3PM. BUT THINKING THUNDERSNOW IS NOT
AS LIKELY AS IT WAS EARLIER TODAY...AND WE ARE ON A DOWNWARD TREND.
AREAS SOUTH OF I-80 AND NW INDIANA...HAVE ALSO BEEN HARDEST HIT BY
SNOW THUS FAR WITH REPORTS AS HIGH AS 2.5 INCHES PER HOUR. THE AREA
OF SNOW RESPONSIBLE FOR THOSE INTENSE RATES HAS MOVED EAST. HOWEVER
ANOTHER BAND OF SNOW COINCIDING WITH THE FGEN BAND STRETCHES FROM
MCHENRY COUNTY THROUGH CHAMPAIGN COUNTY. IT JUST MOVED OVER THE
OFFICE HERE AND VSBY DROPPED TO LESS THAN 1/8 OF A MILE WITH HEAVY
SNOW. AS SUCH WILL KEEP HEAVY SNOW IN THE FORECAST AS THIS BAND
PROGRESSES EASTWARD. HAVE THE BAND PUSHING EAST OF THE CWA BY 5PM
CST.
THE BACK END OF THE SNOW STRETCHES FROM EASTERN MN TO PEORIA TO
DECATUR IL AND IS QUICKLY PUSHING EAST AS WELL. AS SUCH QUICKENED
THE END TIME OF SNOW IN THE GRIDS. LEFT TOTALS AS IS WITH GENERALLY
4 TO 8 INCHES ACROSS THE CWA. EXPECTING SLIGHTLY LOWER TOTALS ALONG
THE IL/WI STATE LINE AND THEN HIGHER TOTALS ACROSS THE SOUTHERN
CWA. WITH THIS BEING A WETTER TYPE SNOW...LEFT BLOWING SNOW OUT OF
THE FORECAST. WIND GUSTS PICK UP SOUTH OF I-80 BEHIND THE TROUGH
AXIS THIS EVENING. GUSTS UP TO 25 KT ARE EXPECTED...AND THEY
DIMINISH BY MORNING.
FOR TEMPS...THE PREVIOUS FORECAST WAS RIGHT ON SO DID NOT MAKE TOO
MANY CHANGES TO TODAYS TEMPS. FOR TONIGHT...WENT A BIT LOWER THAN
GUIDANCE GIVEN THE FRESH SNOW AND CLEARING SKIES. LOWS WILL BE IN
THE MID TEENS TO AROUND 20.
JEE
TUESDAY THROUGH WEDNESDAY...
SEMI-ZONAL FLOW OVERHEAD CONTINUES TO PUSH THE 500MB TROUGH AXIS TO
THE EAST OF THE REGION TUESDAY...WITH SFC RIDGING BUILDING INTO
NORTHERN IL/NORTHWEST IN. THE COMBINATION OF RIDGING...P-CLOUDY
SKIES...ALONG WITH MID-LVL TEMPS BEGINNING TO WARM...SHOULD ALLOW
SFC TEMPS TO WARM MID/UPR 30S TUE AFTN. A FEW POINTS ALONG THE FAR
SOUTHERN CWFA COULD TOUCH 40 DEGREES.
THEN WITH THE SEMI-ZONAL FLOW ALLOWING FOR A RELATIVELY FLUID
ENVIRONMENT...A WEAK TROUGH PIVOTS EAST FROM THE NORTHERN PLAINS TUE
AFTN/EVE...AND BRINGS THICKENING CLOUD COVER BACK TO THE FORECAST
AREA. LOCAL MODEL WAS INDICATING SOME SPRINKLES WITH THE WEAK WAVE
OVER THE NORTHERN PORTIONS OF THE FORECAST AREA TUE EVE...HOWEVER
FEEL TOO MUCH DRY AIR WILL NEED TO BE OVERCOME...SO WILL CONTINUE TO
RIDE WITH A DRY FORECAST THROUGH TUE NGT INTO WED AS FRONTAL
BOUNDARY SWEEPS EAST ACROSS THE CWFA. SFC RIDGING WILL DEPART
EAST...HOWEVER BROAD RIDGING ACROSS THE CENTRAL PLAINS WILL THEN
PROVIDE ANOTHER DRY INFLUENCE FOR THE AREA INTO WED. THIS FEATURE
WILL THEN SHIFT EAST TOWARDS THE OHIO VALLEY.
TEMPS ONLY COOL MARGINALLY TUE NGT ALOFT...SO NOT EXPECTING MUCH
COOLING AT THE SFC...THUS HAVE HELD ONTO TEMPS IN THE LOW/MID 20S
FOR OVERNIGHT LOWS. THEN FOR WED WITH ANOTHER DRY DAY AND P-CLOUDY
SKIES...TEMPS SHUD BE ABLE TO WARM BACK ABOVE FREEZING INTO THE
LOW/MID 30S.
WEAK MID-LVL RIDGE SLIDES OVERHEAD WED AFTN/EVE...WITH SFC RIDGING
KEEPING A SLIGHT INFLUENCE OVER THE CWFA THRU EARLY EVE. THIS SHUD
KEEP PRECIP OUT OF THE FORECAST AREA UNTIL LATE WED NGT/EARLY THUR.
CONFIDENCE...MEDIUM/HIGH.
THURSDAY THROUGH FRIDAY...
FOCUS REMAINS ON THE THURSDAY TIMEFRAME...ESPECIALLY WITH THE
SUBSTANTIAL WARM-UP THAT CONTINUES TO BE PROGGED BY NUMEROUS
FORECAST MODELS. WHILE SOME CORRECTIONS CONTINUE TO TAKE
PLACE...WITH RESPECT TO THE PLACEMENT/INTENSITY OF THE DEVELOPING
SHORTWAVE AND WARM AIR. 500MB TROUGH REMAINS MORE OF AN ELONGATED
SETUP...WITH THE VORT MAX OVER THE NORTHERN ROCKIES DESPITE THE
TROUGH STRETCHING SOUTH THROUGH THE FOOTHILLS OF COLORADO EARLY
THUR. GUIDANCE CONTINUES TO POINT TOWARDS A SFC WAVE DEVELOPING ON
THE LEE-SIDE OF THE ROCKIES NEAR SOUTHEAST COLORADO EARLY THUR. WITH
THE DOWNSTREAM RIDGING OVER THE SOUTHEAST CONUS...RETURN FLOW
MOISTURE WILL LIKELY STREAM NORTH AHEAD OF THIS DEVELOPING SYSTEM.
ENSEMBLES HAVE MAINTAINED A DECENT AGREEMENT WITH PWAT VALUES
NEARING 1" FOR AREAS ALONG AND SOUTH OF I-80 IN NORTHERN
IL/NORTHWEST IN THUR...WITH STRONG MFLUX CONVERGENCE AT 850MB. THIS
COUPLED WITH A VERY ROBUST LLVL JET...AND STRONG INSTABILITY...POINT
TOWARDS NOT ONLY THE POTENTIAL FOR MODERATE RAIN GIVEN THE SURGE IN
WARM AIR OVER THE FORECAST AREA...BUT ALSO THE POSSIBILITY FOR
STRONG THUNDERSTORMS. THE SPC HAS A PORTION OF THE FORECAST
AREA...OUTLOOKED FOR POSSIBLE STRONG THUNDERSTORMS. THIS REMAINS
MAINLY ALONG AND EAST OF A PONTIAC TO RENSSELAER LINE FOR THE MAIN
FOCUS AREA...HOWEVER GIVEN THE CONTINUED UNCERTAINTY ON
TIMING/INTENSITY/PLACEMENT OF THE SYSTEM THIS WILL LIKELY BE
ADJUSTED OVER TIME.
SHORTWAVE THEN SLIDES OVER THE FORECAST AREA THUR EVE...WITH A
FRONTAL BOUNDARY BRINGING AN END TO THE MILD AIRMASS AND RETURNING
P-TYPE BACK TO LGT SNOW BEFORE ENDING FRI MORNING FROM WEST TO EAST.
AFTER TEMPS REACHING INTO THE MID/UPR 40S THUR...FRI HIGHS WILL
RETURN TO MORE SEASONAL CONDS IN THE LOW/MID 30S.
CONFIDENCE...MEDIUM.
SATURDAY THROUGH EARLY NEXT WEEK...
THE UPCOMING WEEKEND THROUGH EARLY NEXT WEEK PATTERN IS PROGGED TO
RETURN TO WHAT HAS BEEN A COMMON PATTERN OF TROUGHING OVER THE GREAT
LAKES REGION...WITH HIGH AMPLITUDE RIDGING PUSHING INTO WESTERN
CANADA. TEMPS FOR THE WEEKEND WILL COOL BACK INTO THE 20S FOR HIGHS.
THEN GUIDANCE IS INDICATING A COUPLE WEAK MID-LVL WAVES TRAVERSING
THE REGION FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK.
CONFIDENCE...MEDIUM/HIGH.
&&
.HYDROLOGY...
LATEST MODEL GUIDANCE CONTINUES TO INDICATE ENHANCED CONCERN
REGARDING FLOODING POTENTIAL FOR THURSDAY...POSSIBLY LINGERING
INTO THE WEEKEND. MORE DETAIL METEOROLOGICAL DISCUSSION IS ABOVE.
NO CHANGES REALLY TO THE PREVIOUS HYDROLOGICAL DISCUSSION OTHER
THAN SLIGHTLY MORE SNOW AND SNOW WATER EQUIVALENT IS EXPECTED TO
BE IN PLACE AFTER TODAY`S SNOW SYSTEM. WILL FRESHEN UP THE ESF
AGAIN THIS MORNING BUT NOT PLANNING ANY BIG CHANGES.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* MAINLY 1-2SM VSBY TIL 00Z IN LIGHT SNOW...REDUCTION TO 1/2 OR
3/4SM LIKELY DURING 23Z HOUR. VSBY IMPROVEMENT AFTER 00Z...WITH
SNOW ENDING 01Z.
* LIGHT SOUTHEAST WINDS TURN TO WEST AROUND 00 OR 01Z WITH SPEEDS
INCREASING TO 10-15 KT.
* VARIABLE MVFR CIGS LOWERING TO LOW END MVFR AS SNOW
ENDS...LINGERING INTO MID OR LATE EVENING.
MDB
//DISCUSSION...UPDATED 22Z...
SNOW BEGINNING TO EXIT THE AREA WITH INTENSITY ALSO DIMINISHING
BUT ONE LAST BAND IS HEADING EAST TO THE CHICAGO AREA LIKELY
REACHING THESE TERMINALS AROUND 23Z. THIS WILL LIKELY BRING VSBY
BACK DOWN BELOW 1SM FOR A BRIEF PERIOD. OTHERWISE EXPECT 1-2SM
VSBY PRIOR TO THAT. THIS BETTER FOCUSED SNOW WILL EXIT AROUND 00Z
THOUGH SOME WRAP AROUND NOTED NEAR DBQ MAY KEEP SOME LIGHT SNOW
LINGERING WITH SOME REDUCED VSBY FOR AN HOUR OR TWO BEYOND. BEYOND
THAT LOWER MVFR CIGS WILL PERSIST THROUGH THE EVENING. LIGHT AND
VARIABLE WINDS WILL TURN WESTERLY AND INCREASE EARLY THIS EVENING.
MDB
FROM 18Z...
GOING FORECAST SEEMS LARGELY ON TRACK FOR THE TERMINALS WITH
MODERATE TO HEAVY SNOW SPREADING NORTHEAST INTO THE REGION EARLY
THIS AFTERNOON AND UPSTREAM OBS SHOWING VSBY QUICKLY DROPPING TO 1/4
TO 1/2 MILE. NARROW CORRIDOR ON INSTABILITY AHEAD OF AN APPROACHING
F-GEN BAND CURRENTLY MOVING ACROSS THE RIVER STILL APPEARS TO BE THE
BEST CHANCE FOR THUNDER TO MOVE NEAR THE TERMINALS...THOUGH STILL
FAVORS AREAS JUST SOUTH OF DOWNTOWN CHICAGO. MDW MAY BE CLOSE BUT DO
NOT HAVE THE CONFIDENCE IN COVERAGE TO ADD AT THIS TIME. DRIER AIR
PUSHES INTO THE AREA BY LATE AFTERNOON/EARLY EVENING AND RATES
SHOULD TAPER...THEN FORCING ENDS ABRUPTLY MID EVENING. LINGERING LOW
LEVEL MOISTURE WILL RESULT IN LOWER MVFR OR PSBLY IFR CIGS HANGING
OUT OVERNIGHT...THOUGH EXPECT VFR CONDITIONS BY AROUND DAYBREAK
TOMORROW.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN PRIMARILY 1-2SM VSBY WITH REDUCTION TO LESS
THAN 1SM AT TIMES DURING 23Z HOUR. MEDIUM-HIGH CONFIDENCE IN
MVFR TAKING OVER AND SNOW MAINLY ENDING TOWARD 01Z.
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS AND TIMING OF SHIFT TO
WEST.
* HIGH CONFIDENCE IN VARIABLE MVFR CIGS BECOMING STEADY LOW MVFR
EARLY THIS EVENING...MEDIUM CONFIDENCE IN TIMING OF SCATTERING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH WEDNESDAY...PREDOMINANTLY VFR.
WEDNESDAY NIGHT...RAIN OR FZRA DEVELOPING.
THURSDAY..RAIN/FOG/IFR LIKELY. FZRA POSSIBLE IN THE MORNING.
FRIDAY...VFR PROBABLE.
SATURDAY AND SUNDAY...SOME POTENTIAL FOR SNOW.
IZZI
&&
.MARINE...
300 PM CST
HAVE EXTENDED THE GALE WARNING FOR THE CENTRAL PORTIONS OF LAKE
MICHIGAN INTO THIS EVENING AS A STRONG SOUTHEASTERLY PRESSURE
GRADIENT WILL REMAIN...BETWEEN STRONG HIGH PRESSURE SLOWLY MOVES
THROUGH THE NERN CONUS AND A DEEP TROUGH AND STRONG COLD FRONT
MOVE THROUGH THE UPPER MISSISSIPPI VALLEY AND INTO THE WESTERN
GREAT LAKES REGION. THE COLD FRONT WILL PUSH ACROSS THE LAKE
TONIGHT AND A WEAK RIDGE WILL QUICKLY FOLLOW THE FRONT...SETTING
UP A PERIOD OF RELATIVELY VARIABLE...BUT WEAKER WINDS OVER THE
LAKE. BY TUESDAY NIGHT...A CLIPPER TYPE SYSTEM WILL TRACK THROUGH
SRN CANADA...DRAGGING ANOTHER COLD FRONT ACROSS THE PLAINS. AS THE
FRONTAL TROUGH APPROACHES THE LAKES...SLY-SWLY WINDS WILL INCREASE
TO ARND 30KT...WITH OCCASIONAL GALE FORCE GUSTS POSSIBLE. THE NEXT
SIGNIFICANT WEATHER SYSTEM TO IMPACT THE LAKES IS EXPECTED TO
DEVELOP OVER THE PLAINS WEDNESDAY NIGHT WITH WEAKER LOW PRESSURE
DEVELOPING OVER THE DAKOTAS AND A STRONGER LOW DEVELOPING OVER THE
SOUTH HIGH PLAINS. THE SOUTHERN LOW WILL BE THE MAIN SYSTEM OF
CONCERN AS IT IS EXPECTED TO DEEPEN RAPIDLY AS IT TRACKS THROUGH
ERN WISCONSIN THURSDAY NIGHT...WHILE DRAGGING A STRONG COLD FRONT
ACROSS THE LAKE. SWLY WINDS MAY APPROACH GALE FORCE JUST AHEAD OF
THE COLD FRONT...AND WILL LIKELY EXCEED GALE FORCE WHILE SHIFTING
TO WLY FOLLOWING THE FROPA.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032-ILZ039 UNTIL 6 PM MONDAY.
WINTER STORM WARNING...ILZ006-ILZ013-ILZ014-ILZ022-ILZ023-ILZ033
UNTIL 9 PM MONDAY.
IN...WINTER STORM WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
9 PM MONDAY.
LM...GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876 UNTIL 9 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
403 PM CST MON FEB 17 2014
.DISCUSSION...
248 PM CST
SHORT TERM...THROUGH TONIGHT...
WILL LEAVE THE WINTER STORM WARNING AS IS...WITH THE WESTERN
COUNTIES ENDING AT 6PM AND THE EASTERN COUNTIES ENDING AT 9PM CST.
TWO LOWS ARE OVER THE REGION. THE DEEPER ONE IS OVER SOUTHWEST MN
WHILE THE OTHER IS OVER SOUTHERN IL. BOTH LOWS HAVE DEEPENED IN
THE PAST HOUR. ALOFT...THERE IS AN UPPER LEVEL TROUGH FROM MN
THROUGH MO WITH A SLIGHT NEGATIVE TILT. THIS TROUGH IS PROVIDING THE
LIFT FOR THE SNOW. THE RAP HAS HAD A PRETTY GOOD IDEA OF THE FGEN
FORCING AND CAPE TODAY. THE FGEN IS FOCUSED JUST SOUTH OF THE CWA
AND HAVE IT PASSING FROM MCLEAN COUNTY INTO CENTRAL INDIANA LATE
THIS AFTERNOON AND THE CAPE REMAINS ON THE WARM SIDE OF THE FGEN
BAND. AS SUCH THINKING THUNDERSNOW WILL REMAIN CONFINED TO AREAS
SOUTH OF I-80 AND NORTHWEST INDIANA FOR THE NEXT COUPLE OF HOURS
BEFORE SHIFTING INTO INDIANA BY 3PM. BUT THINKING THUNDERSNOW IS NOT
AS LIKELY AS IT WAS EARLIER TODAY...AND WE ARE ON A DOWNWARD TREND.
AREAS SOUTH OF I-80 AND NW INDIANA...HAVE ALSO BEEN HARDEST HIT BY
SNOW THUS FAR WITH REPORTS AS HIGH AS 2.5 INCHES PER HOUR. THE AREA
OF SNOW RESPONSIBLE FOR THOSE INTENSE RATES HAS MOVED EAST. HOWEVER
ANOTHER BAND OF SNOW COINCIDING WITH THE FGEN BAND STRETCHES FROM
MCHENRY COUNTY THROUGH CHAMPAIGN COUNTY. IT JUST MOVED OVER THE
OFFICE HERE AND VSBY DROPPED TO LESS THAN 1/8 OF A MILE WITH HEAVY
SNOW. AS SUCH WILL KEEP HEAVY SNOW IN THE FORECAST AS THIS BAND
PROGRESSES EASTWARD. HAVE THE BAND PUSHING EAST OF THE CWA BY 5PM
CST.
THE BACK END OF THE SNOW STRETCHES FROM EASTERN MN TO PEORIA TO
DECATUR IL AND IS QUICKLY PUSHING EAST AS WELL. AS SUCH QUICKENED
THE END TIME OF SNOW IN THE GRIDS. LEFT TOTALS AS IS WITH GENERALLY
4 TO 8 INCHES ACROSS THE CWA. EXPECTING SLIGHTLY LOWER TOTALS ALONG
THE IL/WI STATE LINE AND THEN HIGHER TOTALS ACROSS THE SOUTHERN
CWA. WITH THIS BEING A WETTER TYPE SNOW...LEFT BLOWING SNOW OUT OF
THE FORECAST. WIND GUSTS PICK UP SOUTH OF I-80 BEHIND THE TROUGH
AXIS THIS EVENING. GUSTS UP TO 25 KT ARE EXPECTED...AND THEY
DIMINISH BY MORNING.
FOR TEMPS...THE PREVIOUS FORECAST WAS RIGHT ON SO DID NOT MAKE TOO
MANY CHANGES TO TODAYS TEMPS. FOR TONIGHT...WENT A BIT LOWER THAN
GUIDANCE GIVEN THE FRESH SNOW AND CLEARING SKIES. LOWS WILL BE IN
THE MID TEENS TO AROUND 20.
JEE
TUESDAY THROUGH WEDNESDAY...
SEMI-ZONAL FLOW OVERHEAD CONTINUES TO PUSH THE 500MB TROUGH AXIS TO
THE EAST OF THE REGION TUESDAY...WITH SFC RIDGING BUILDING INTO
NORTHERN IL/NORTHWEST IN. THE COMBINATION OF RIDGING...P-CLOUDY
SKIES...ALONG WITH MID-LVL TEMPS BEGINNING TO WARM...SHOULD ALLOW
SFC TEMPS TO WARM MID/UPR 30S TUE AFTN. A FEW POINTS ALONG THE FAR
SOUTHERN CWFA COULD TOUCH 40 DEGREES.
THEN WITH THE SEMI-ZONAL FLOW ALLOWING FOR A RELATIVELY FLUID
ENVIRONMENT...A WEAK TROUGH PIVOTS EAST FROM THE NORTHERN PLAINS TUE
AFTN/EVE...AND BRINGS THICKENING CLOUD COVER BACK TO THE FORECAST
AREA. LOCAL MODEL WAS INDICATING SOME SPRINKLES WITH THE WEAK WAVE
OVER THE NORTHERN PORTIONS OF THE FORECAST AREA TUE EVE...HOWEVER
FEEL TOO MUCH DRY AIR WILL NEED TO BE OVERCOME...SO WILL CONTINUE TO
RIDE WITH A DRY FORECAST THROUGH TUE NGT INTO WED AS FRONTAL
BOUNDARY SWEEPS EAST ACROSS THE CWFA. SFC RIDGING WILL DEPART
EAST...HOWEVER BROAD RIDGING ACROSS THE CENTRAL PLAINS WILL THEN
PROVIDE ANOTHER DRY INFLUENCE FOR THE AREA INTO WED. THIS FEATURE
WILL THEN SHIFT EAST TOWARDS THE OHIO VALLEY.
TEMPS ONLY COOL MARGINALLY TUE NGT ALOFT...SO NOT EXPECTING MUCH
COOLING AT THE SFC...THUS HAVE HELD ONTO TEMPS IN THE LOW/MID 20S
FOR OVERNIGHT LOWS. THEN FOR WED WITH ANOTHER DRY DAY AND P-CLOUDY
SKIES...TEMPS SHUD BE ABLE TO WARM BACK ABOVE FREEZING INTO THE
LOW/MID 30S.
WEAK MID-LVL RIDGE SLIDES OVERHEAD WED AFTN/EVE...WITH SFC RIDGING
KEEPING A SLIGHT INFLUENCE OVER THE CWFA THRU EARLY EVE. THIS SHUD
KEEP PRECIP OUT OF THE FORECAST AREA UNTIL LATE WED NGT/EARLY THUR.
CONFIDENCE...MEDIUM/HIGH.
THURSDAY THROUGH FRIDAY...
FOCUS REMAINS ON THE THURSDAY TIMEFRAME...ESPECIALLY WITH THE
SUBSTANTIAL WARM-UP THAT CONTINUES TO BE PROGGED BY NUMEROUS
FORECAST MODELS. WHILE SOME CORRECTIONS CONTINUE TO TAKE
PLACE...WITH RESPECT TO THE PLACEMENT/INTENSITY OF THE DEVELOPING
SHORTWAVE AND WARM AIR. 500MB TROUGH REMAINS MORE OF AN ELONGATED
SETUP...WITH THE VORT MAX OVER THE NORTHERN ROCKIES DESPITE THE
TROUGH STRETCHING SOUTH THROUGH THE FOOTHILLS OF COLORADO EARLY
THUR. GUIDANCE CONTINUES TO POINT TOWARDS A SFC WAVE DEVELOPING ON
THE LEE-SIDE OF THE ROCKIES NEAR SOUTHEAST COLORADO EARLY THUR. WITH
THE DOWNSTREAM RIDGING OVER THE SOUTHEAST CONUS...RETURN FLOW
MOISTURE WILL LIKELY STREAM NORTH AHEAD OF THIS DEVELOPING SYSTEM.
ENSEMBLES HAVE MAINTAINED A DECENT AGREEMENT WITH PWAT VALUES
NEARING 1" FOR AREAS ALONG AND SOUTH OF I-80 IN NORTHERN
IL/NORTHWEST IN THUR...WITH STRONG MFLUX CONVERGENCE AT 850MB. THIS
COUPLED WITH A VERY ROBUST LLVL JET...AND STRONG INSTABILITY...POINT
TOWARDS NOT ONLY THE POTENTIAL FOR MODERATE RAIN GIVEN THE SURGE IN
WARM AIR OVER THE FORECAST AREA...BUT ALSO THE POSSIBILITY FOR
STRONG THUNDERSTORMS. THE SPC HAS A PORTION OF THE FORECAST
AREA...OUTLOOKED FOR POSSIBLE STRONG THUNDERSTORMS. THIS REMAINS
MAINLY ALONG AND EAST OF A PONTIAC TO RENSSELAER LINE FOR THE MAIN
FOCUS AREA...HOWEVER GIVEN THE CONTINUED UNCERTAINTY ON
TIMING/INTENSITY/PLACEMENT OF THE SYSTEM THIS WILL LIKELY BE
ADJUSTED OVER TIME.
SHORTWAVE THEN SLIDES OVER THE FORECAST AREA THUR EVE...WITH A
FRONTAL BOUNDARY BRINGING AN END TO THE MILD AIRMASS AND RETURNING
P-TYPE BACK TO LGT SNOW BEFORE ENDING FRI MORNING FROM WEST TO EAST.
AFTER TEMPS REACHING INTO THE MID/UPR 40S THUR...FRI HIGHS WILL
RETURN TO MORE SEASONAL CONDS IN THE LOW/MID 30S.
CONFIDENCE...MEDIUM.
SATURDAY THROUGH EARLY NEXT WEEK...
THE UPCOMING WEEKEND THROUGH EARLY NEXT WEEK PATTERN IS PROGGED TO
RETURN TO WHAT HAS BEEN A COMMON PATTERN OF TROUGHING OVER THE GREAT
LAKES REGION...WITH HIGH AMPLITUDE RIDGING PUSHING INTO WESTERN
CANADA. TEMPS FOR THE WEEKEND WILL COOL BACK INTO THE 20S FOR HIGHS.
THEN GUIDANCE IS INDICATING A COUPLE WEAK MID-LVL WAVES TRAVERSING
THE REGION FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK.
CONFIDENCE...MEDIUM/HIGH.
&&
.HYDROLOGY...
LATEST MODEL GUIDANCE CONTINUES TO INDICATE ENHANCED CONCERN
REGARDING FLOODING POTENTIAL FOR THURSDAY...POSSIBLY LINGERING
INTO THE WEEKEND. MORE DETAIL METEOROLOGICAL DISCUSSION IS ABOVE.
NO CHANGES REALLY TO THE PREVIOUS HYDROLOGICAL DISCUSSION OTHER
THAN SLIGHTLY MORE SNOW AND SNOW WATER EQUIVALENT IS EXPECTED TO
BE IN PLACE AFTER TODAY`S SNOW SYSTEM. WILL FRESHEN UP THE ESF
AGAIN THIS MORNING BUT NOT PLANNING ANY BIG CHANGES.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTHEASTERLY WINDS BECOMING LIGHT AND VARIABLE LATE THIS
AFTERNOON/EARLY EVENING...THEN TURNING WESTERLY.
* PERIODS OF HEAVY SNOW WITH NEAR WHITEOUT CONDITIONS AT TIMES
WITH SNOW RATES IN EXCESS OF AN INCH PER HOUR AT TIMES.
* POTENTIAL FOR THUNDERSNOW.
BMD
//DISCUSSION...UPDATED 18Z...
GOING FORECAST SEEMS LARGELY ON TRACK FOR THE TERMINALS WITH
MODERATE TO HEAVY SNOW SPREADING NORTHEAST INTO THE REGION EARLY
THIS AFTERNOON AND UPSTREAM OBS SHOWING VSBY QUICKLY DROPPING TO 1/4
TO 1/2 MILE. NARROW CORRIDOR ON INSTABILITY AHEAD OF AN APPROACHING
F-GEN BAND CURRENTLY MOVING ACROSS THE RIVER STILL APPEARS TO BE THE
BEST CHANCE FOR THUNDER TO MOVE NEAR THE TERMINALS...THOUGH STILL
FAVORS AREAS JUST SOUTH OF DOWNTOWN CHICAGO. MDW MAY BE CLOSE BUT DO
NOT HAVE THE CONFIDENCE IN COVERAGE TO ADD AT THIS TIME. DRIER AIR
PUSHES INTO THE AREA BY LATE AFTERNOON/EARLY EVENING AND RATES
SHOULD TAPER...THEN FORCING ENDS ABRUPTLY MID EVENING. LINGERING LOW
LEVEL MOISTURE WILL RESULT IN LOWER MVFR OR PSBLY IFR CIGS HANGING
OUT OVERNIGHT...THOUGH EXPECT VFR CONDITIONS BY AROUND DAYBREAK
TOMORROW.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN WIND SPEEDS/DIRECTION & TIMING WIND SHIFT.
* HIGH CONFIDENCE IN VSBY FALLING TO 1/4SM OR LESS WITH SNOW RATES
IN EXCESS OF AN INCH PER HOUR AT TIMES.
* LOW CONFIDENCE IN THUNDERSNOW AT TERMINALS.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH WEDNESDAY...PREDOMINANTLY VFR.
WEDNESDAY NIGHT...RAIN OR FZRA DEVELOPING.
THURSDAY..RAIN/FOG/IFR LIKELY. FZRA POSSIBLE IN THE MORNING.
FRIDAY...VFR PROBABLE.
SATURDAY AND SUNDAY...SOME POTENTIAL FOR SNOW.
IZZI
&&
.MARINE...
300 PM CST
HAVE EXTENDED THE GALE WARNING FOR THE CENTRAL PORTIONS OF LAKE
MICHIGAN INTO THIS EVENING AS A STRONG SOUTHEASTERLY PRESSURE
GRADIENT WILL REMAIN...BETWEEN STRONG HIGH PRESSURE SLOWLY MOVES
THROUGH THE NERN CONUS AND A DEEP TROUGH AND STRONG COLD FRONT
MOVE THROUGH THE UPPER MISSISSIPPI VALLEY AND INTO THE WESTERN
GREAT LAKES REGION. THE COLD FRONT WILL PUSH ACROSS THE LAKE
TONIGHT AND A WEAK RIDGE WILL QUICKLY FOLLOW THE FRONT...SETTING
UP A PERIOD OF RELATIVELY VARIABLE...BUT WEAKER WINDS OVER THE
LAKE. BY TUESDAY NIGHT...A CLIPPER TYPE SYSTEM WILL TRACK THROUGH
SRN CANADA...DRAGGING ANOTHER COLD FRONT ACROSS THE PLAINS. AS THE
FRONTAL TROUGH APPROACHES THE LAKES...SLY-SWLY WINDS WILL INCREASE
TO ARND 30KT...WITH OCCASIONAL GALE FORCE GUSTS POSSIBLE. THE NEXT
SIGNIFICANT WEATHER SYSTEM TO IMPACT THE LAKES IS EXPECTED TO
DEVELOP OVER THE PLAINS WEDNESDAY NIGHT WITH WEAKER LOW PRESSURE
DEVELOPING OVER THE DAKOTAS AND A STRONGER LOW DEVELOPING OVER THE
SOUTH HIGH PLAINS. THE SOUTHERN LOW WILL BE THE MAIN SYSTEM OF
CONCERN AS IT IS EXPECTED TO DEEPEN RAPIDLY AS IT TRACKS THROUGH
ERN WISCONSIN THURSDAY NIGHT...WHILE DRAGGING A STRONG COLD FRONT
ACROSS THE LAKE. SWLY WINDS MAY APPROACH GALE FORCE JUST AHEAD OF
THE COLD FRONT...AND WILL LIKELY EXCEED GALE FORCE WHILE SHIFTING
TO WLY FOLLOWING THE FROPA.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032-ILZ039 UNTIL 6 PM MONDAY.
WINTER STORM WARNING...ILZ006-ILZ013-ILZ014-ILZ022-ILZ023-ILZ033
UNTIL 9 PM MONDAY.
IN...WINTER STORM WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
9 PM MONDAY.
LM...GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876 UNTIL 9 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
THE FORECAST DISCUSSION FOR THE REMAINDER OF THE WEEK WILL BE
POSTLY SHORTLY.
&&
.HYDROLOGY...
LATEST MODEL GUIDANCE DOES LOOK MORE WORRISOME THAN IT DID 24
HOURS AGO REGARDING THE FLOOD POTENTIAL THURSDAY...POSSIBLY
LINGERING INTO THE WEEKEND. MORE DETAIL METEOROLOGICAL DISCUSSION
IS ABOVE. NO CHANGES REALLY TO THE PREVIOUS HYDROLOGICAL
DISCUSSION OTHER THAN SLIGHTLY MORE SNOW AND SNOW WATER
EQUIVALENT IS EXPECTED TO BE IN PLACE AFTER TODAY`S SNOW SYSTEM.
WILL FRESHEN UP THE ESF AGAIN THIS MORNING BUT NOT PLANNING ANY
BIG CHANGES.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTHEASTERLY WINDS BECOMING LIGHT AND VARIABLE LATE THIS
AFTERNOON/EARLY EVENING...THEN TURNING WESTERLY.
* PERIODS OF HEAVY SNOW WITH NEAR WHITEOUT CONDITIONS AT TIMES
WITH SNOW RATES IN EXCESS OF AN INCH PER HOUR AT TIMES.
* POTENTIAL FOR THUNDERSNOW.
BMD
//DISCUSSION...UPDATED 18Z...
GOING FORECAST SEEMS LARGELY ON TRACK FOR THE TERMINALS WITH
MODERATE TO HEAVY SNOW SPREADING NORTHEAST INTO THE REGION EARLY
THIS AFTERNOON AND UPSTREAM OBS SHOWING VSBY QUICKLY DROPPING TO 1/4
TO 1/2 MILE. NARROW CORRIDOR ON INSTABILITY AHEAD OF AN APPROACHING
F-GEN BAND CURRENTLY MOVING ACROSS THE RIVER STILL APPEARS TO BE THE
BEST CHANCE FOR THUNDER TO MOVE NEAR THE TERMINALS...THOUGH STILL
FAVORS AREAS JUST SOUTH OF DOWNTOWN CHICAGO. MDW MAY BE CLOSE BUT DO
NOT HAVE THE CONFIDENCE IN COVERAGE TO ADD AT THIS TIME. DRIER AIR
PUSHES INTO THE AREA BY LATE AFTERNOON/EARLY EVENING AND RATES
SHOULD TAPER...THEN FORCING ENDS ABRUPTLY MID EVENING. LINGERING LOW
LEVEL MOISTURE WILL RESULT IN LOWER MVFR OR PSBLY IFR CIGS HANGING
OUT OVERNIGHT...THOUGH EXPECT VFR CONDITIONS BY AROUND DAYBREAK
TOMORROW.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN WIND SPEEDS/DIRECTION & TIMING WIND SHIFT.
* HIGH CONFIDENCE IN VSBY FALLING TO 1/4SM OR LESS WITH SNOW RATES
IN EXCESS OF AN INCH PER HOUR AT TIMES.
* LOW CONFIDENCE IN THUNDERSNOW AT TERMINALS.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH WEDNESDAY...PREDOMINANTLY VFR.
WEDNESDAY NIGHT...RAIN OR FZRA DEVELOPING.
THURSDAY..RAIN/FOG/IFR LIKELY. FZRA POSSIBLE IN THE MORNING.
FRIDAY...VFR PROBABLE.
SATURDAY AND SUNDAY...SOME POTENTIAL FOR SNOW.
IZZI
&&
.MARINE...
300 PM CST
HAVE EXTENDED THE GALE WARNING FOR THE CENTRAL PORTIONS OF LAKE
MICHIGAN INTO THIS EVENING AS A STRONG SOUTHEASTERLY PRESSURE
GRADIENT WILL REMAIN...BETWEEN STRONG HIGH PRESSURE SLOWLY MOVES
THROUGH THE NERN CONUS AND A DEEP TROUGH AND STRONG COLD FRONT
MOVE THROUGH THE UPPER MISSISSIPPI VALLEY AND INTO THE WESTERN
GREAT LAKES REGION. THE COLD FRONT WILL PUSH ACROSS THE LAKE
TONIGHT AND A WEAK RIDGE WILL QUICKLY FOLLOW THE FRONT...SETTING
UP A PERIOD OF RELATIVELY VARIABLE...BUT WEAKER WINDS OVER THE
LAKE. BY TUESDAY NIGHT...A CLIPPER TYPE SYSTEM WILL TRACK THROUGH
SRN CANADA...DRAGGING ANOTHER COLD FRONT ACROSS THE PLAINS. AS THE
FRONTAL TROUGH APPROACHES THE LAKES...SLY-SWLY WINDS WILL INCREASE
TO ARND 30KT...WITH OCCASIONAL GALE FORCE GUSTS POSSIBLE. THE NEXT
SIGNIFICANT WEATHER SYSTEM TO IMPACT THE LAKES IS EXPECTED TO
DEVELOP OVER THE PLAINS WEDNESDAY NIGHT WITH WEAKER LOW PRESSURE
DEVELOPING OVER THE DAKOTAS AND A STRONGER LOW DEVELOPING OVER THE
SOUTH HIGH PLAINS. THE SOUTHERN LOW WILL BE THE MAIN SYSTEM OF
CONCERN AS IT IS EXPECTED TO DEEPEN RAPIDLY AS IT TRACKS THROUGH
ERN WISCONSIN THURSDAY NIGHT...WHILE DRAGGING A STRONG COLD FRONT
ACROSS THE LAKE. SWLY WINDS MAY APPROACH GALE FORCE JUST AHEAD OF
THE COLD FRONT...AND WILL LIKELY EXCEED GALE FORCE WHILE SHIFTING
TO WLY FOLLOWING THE FROPA.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032-ILZ039 UNTIL 6 PM MONDAY.
WINTER STORM WARNING...ILZ006-ILZ013-ILZ014-ILZ022-ILZ023-ILZ033
UNTIL 9 PM MONDAY.
IN...WINTER STORM WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
9 PM MONDAY.
LM...GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876 UNTIL 9 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
158 PM CST MON FEB 17 2014
.DISCUSSION...
330 AM CST
SHORT TERM (THROUGH TONIGHT)...
MAIN CONCERNS ARE WITH INCREASED POTENTIAL FOR A PERIOD OF HEAVY
SNOW THIS AFTERNOON FOR THE ENTIRE CWA WHICH COULD HAVE SIGNIFICANT
IMPACTS WITH WHITE OUT CONDITIONS UNDER POSSIBLE TWO TO THREE
INCH PER HOUR SNOWFALL RATES SOME OF WHICH COULD FALL UNDER
CONVECTIVE ELEMENTS...WITH AREA WIDE 4 TO 8 INCHES LIKELY AND SOME
ISOLATED AMOUNTS NEAR 10 INCHES DEFINITELY NOT OUT OF THE QUESTION.
IMPRESSIVE STRONG STORM ANTICIPATED TO TAKE SHAPE OVER THE AREA
LATER TODAY CAN BE OBSERVED ON SATELLITE IMAGERY...WITH MID/UPPER
LEVEL TROUGH CURRENTLY PUSHING EAST THROUGH THE NORTHERN PLAINS. OUT
AHEAD OF THIS SYSTEM...LATEST RAP ANALYSIS DEPICTING STRONG
ISENTROPIC ASCENT OCCURRING ACROSS THE ENTIRE REGION INCLUDING
LOCALLY OVER THE CWA. THIS HAS RESULTED IN PERSISTENT MID/HIGH LEVEL
CLOUD COVER TO STREAM OUT AHEAD OF THIS SYSTEM...WITH CURRENT RADAR
IMAGERY LIGHTING UP WITH SOME DECENT RETURNS. ALTHOUGH RATHER DRY
AIR IN PLACE HAS LIMITED ANY PRECIP TO REACH THE SURFACE AND
ANTICIPATE FOR THIS TO FURTHER BE THE CASE OVER THE NEXT COUPLE OF
HOURS. WHAT COULD BE EXPECTED IN THE NEAR TERM ARE SOME ISOLATED
FLURRIES PRIMARILY OVER THE NORTHWEST HALF OF THE CWA...WITH RFD
CURRENTLY REPORTING 9 MILES IN LIGHT SNOW. ISENTROPIC ASCENT WILL
CONTINUE THIS MORNING...WITH SHORT TERM GUIDANCE HINTING AT THE
POSSIBILITY FOR FURTHER PRECIP DEVELOPMENT ENTERING THE SOUTHWEST CWA
JUST AFTER THE 12Z TIME FRAME. PREVIOUSLY DISCUSSED WARMING/WARM
WEDGE STILL ANTICIPATED HERE THIS MORNING AND COULD INITIALLY BRING
A WINTRY MIX BUT STAYING CONFINED TO THE SOUTHERN HALF OF THE
CWA...PRIMARILY SOUTH OF THE I80 CORRIDOR. IF ANYTHING WERE TO OCCUR
DURING THIS TIME FRAME...ANTICIPATE IT TO BE ON THE LIGHTER SIDE
WITH THE PREVIOUSLY MENTIONED DRIER AIR STILL NEEDING TO BE
OVERCOME. NONETHELESS...WITH AN ANTICIPATED SLOWING TREND WITH THE
EVOLUTION OF TODAY`S SYSTEM...THIS WINTRY MIX COULD BE MORE PREVALENT
THAN PREVIOUSLY THOUGHT TO START THE PERIOD. SO HAVE INCLUDED CHANCE
ZR/IP IN THE GRIDS THROUGH 15Z.
CAN MAKE OUT TWO SEPARATE PIECES OF STRONG ENERGY TRAVERSING THE
MID LEVEL FLOW...NOW WITH ALL GUIDANCE IN STRONG AGREEMENT WITH THE
EVOLUTION OF THIS ENERGY AS IT APPROACHES THE REGION. ABOUT THE ONLY
DIFFERENCE AT THIS TIME IS SOME SLIGHT TIMING DIFFERENCES WITH THE
APPROACH OF THE BETTER FORCING/PRECIP LATER TODAY. A CONTINUED
SLOWER TREND HAS BEEN THE PREFERRED TREND HERE THIS MORNING...AND
HAVE DELAYED HIGHEST POPS TODAY. ALTHOUGH DID NOT OVERLY STRAY TOO
MUCH WITH THE PREVIOUSLY MENTIONED ISENTROPIC ASCENT AND POTENTIAL
PRECIP OUT AHEAD OF IT. HAVE CONTINUED THE MENTION IN THE GRIDS FOR
A MIX OF SLEET FOR LATER IN THE MORNING...MAINLY FOR THE SOUTHERN
TIER OF COUNTIES. ALTHOUGH THERMAL PROFILES WOULD BE SUPPORTIVE OF
THIS WINTRY MIX CONTINUING...HAVE LIMITED MENTION OF THIS MIX AS
BETTER FORCING SHOULD BE ARRIVING DURING THIS TIME. WHATEVER
LINGERING WARM WEDGE IN THE COLUMN WILL QUICKLY COOL THE COLUMN TO
THE WET BULB AS STRONG DYNAMIC FORCING ARRIVES...WITH ANY MIX
QUICKLY CHANGING OVER TO ALL SNOW.
ONCE AGAIN...ALL GUIDANCE POINTING AT SIGNIFICANT SNOWFALL RATES
BEGINNING AT SOON AS LATE MORNING FOR THE WESTERN CWA. TWO PIECES OF
ENERGY WILL PHASE TOGETHER BY EARLY AFTERNOON...WITH THIS MID/UPPER
LEVEL TROUGH BECOMING NEGATIVELY TILTED. AS THIS OCCURS...ATTENDANT
LOW TO DEEPEN AS IT MOVES THROUGH CENTRAL ILLINOIS WITH 850MB LOW
REALLY BEGINNING TO TAKE SHAPE. STRONG DYNAMICAL FORCING ASSOCIATED
WITH THIS MID LEVEL TROUGH AND SIGNIFICANT HEIGHT FALLS WILL ALLOW
FORCING TO SWING THROUGH THE CWA BY LATE MORNING INTO THE EARLY
AFTERNOON. ASSOCIATED FRONTOGENETICAL FORCING WILL LIKEWISE PUSH
EAST THROUGH THE AREA THIS AFTERNOON...WITH THE PRESENCE OF NEGATIVE
EPV. THIS PRESENCE OF BOTH SLANTWISE AND UPRIGHT MOTIONS ARE LEADING
FOR SOME REALLY IMPRESSIVE VERTICAL MOTION...WITH FORECAST OMEGA
AMONG ALL GUIDANCE SOME OF THE HIGHEST IVE OBSERVED IN SOME TIME.
THE STRONGEST VERTICAL MOTIONS ARE EXPECTED TO PUSH EAST TO WEST
ACROSS THE CWA INTO THE EARLY AFTERNOON TIME FRAME AND CONTINUING
THROUGH MID/LATE AFTERNOON...WITH FORCING CENTERED RIGHT IN THE
MIDDLE OF THE CWA. ALTHOUGH CURRENT FORECAST SNOW TOTALS ARE THE
HIGHEST IN THESE LOCATIONS...TOTALS DONT STRAY TOO MUCH FROM THE
AMOUNTS ACROSS THE REMAINING CWA. THIS IS IN DUE TO PART TO HOW
UNSTABLE THIS SYSTEM WILL BE...INCLUDING CONVECTIVE INSTABILITY.
BOTH NAM/GFS SHOWING IMPRESSIVE MUCAPE TO PUSH NORTHEAST THROUGH THE
CWA AS EARLY AS MID MORNING...AND THE BEGINNING STAGES OF THIS CAN
ALREADY BE OBSERVED TO OUR WEST/SOUTHWEST WITH LATEST RAP ANALYSIS
DEPICTING 100-200 J/KG OVER IOWA/MISSOURI/KANSAS. WITH SREF GUIDANCE
INDICATING HIGH PROBABILITIES OF AT LEAST 50-100 J/KG OF MUCAPE TO
MOVE OVERHEAD LATER TODAY...FEEL THAT THE NAM/GFS SOLUTION OF 100 TO
ALMOST 300 J/KG IS NOT OF THE QUESTION. THE PRESENCE OF THIS STRONG
FORCING...STRONG INSTABILITY AND ABUNDANCE OF MOISTURE NOT ONLY
LIKELY BEING PRESENT BUT ALSO COMING TOGETHER...HAS STEERED THE
FORECAST SIGNIFICANTLY MORE PESSIMISTIC THIS MORNING.
HEAVIEST SNOW...WHICH WILL FALL WITH HIGH INTENSITIES AND POSSIBLY
AT A RATE OF TWO TO THREE INCHES PER HOUR AT TIMES SHOULD ARRIVE THE
FAR WESTERN CWA BY MID/LATE MORNING...AND THEN SPREADING EAST
THROUGH THE REMAINING CWA BY EARLY AFTERNOON. EXPECT THESE HIGH
SNOWFALL INTENSITIES THROUGH MID TO LATE AFTERNOON...AND POSSIBLY
CONTINUE INTO THE EARLY EVENING FOR THE EASTERN THIRD OF THE CWA.
THIS HEAVY SNOW WILL QUICKLY ACCUMULATE ON ROADS WITH NEAR
VISIBILITY LIKELY UNDER THIS HEAVY SNOW...CREATING VERY HAZARDOUS
CONDITIONS. AS WAS MENTIONED PREVIOUSLY...THE HIGHEST TOTALS ARE IN
THE CWA ALIGNED WITH THE BETTER FORCING...BUT FEEL THAT ANY LACKING
FORCING WILL BE SUPPLEMENTED WITH THE CONVECTIVE NATURE OF THIS
SYSTEM. CONVECTIVE ALLOWING MODELS INDICATE THE PRESENCE OF THUNDER
BREAKING OUT BY EARLY AFTERNOON. ALTHOUGH GUIDANCE IS HINTING THAT
THIS WILL BE MORE PREFERRED ACROSS THE SOUTHERN CWA...WITH GUIDANCE
INDICATING INSTABILITY INTO SOUTHERN WISCONSIN...HAVE INCLUDED A
CHANCE FOR THUNDER IN THE GRIDS FOR THE ENTIRE CWA. ITS THESE
CONVECTIVE ELEMENTS WHICH COULD SUPPLEMENT HIGHER RATES AND
RESULTANT SNOWFALL TOTALS. SO FOR THE WARNING ISSUED
OVERNIGHT...WILL HAVE AREA WIDE 4 TO 8 INCHES WITH THE POSSIBILITY OF
SLIGHTLY HIGHER AMOUNTS NEAR 10 INCHES. IF THESE CONVECTIVE ELEMENTS
WERE TO MATERIALIZE...THEN AREAS DEFINITELY COULD OBSERVE THESE
HIGHER AMOUNTS. ALSO...ITS POSSIBLE THAT THESE AMOUNTS COULD BE
OBSERVED IN A 4-6 HOUR WINDOW. HAVE THE WARNING ENDING EARLY THIS
EVENING FOR THE WESTERN CWA AND THEN AT 3Z LATER THIS EVENING FOR
THE EASTERN CWA. IF LATER GUIDANCE THIS MORNING CONTINUES TO SUPPORT
CURRENT THINKING...SITUATION FORECAST TO UNFOLD LATER THIS AFTERNOON
WILL DEFINITELY BE SOMETHING TO NOT TAKE LIGHTLY.
RODRIGUEZ
LONG TERM (TUESDAY THROUGH SUNDAY)...
FAST ON THE HEELS OF TODAY`S DEPARTING SYSTEM WILL BE ANOTHER
NORTHERN STREAM SYSTEM TRACKING ACROSS SOUTHERN CANADA. VERY STRONG
WARM AIR ADVECTION WILL BE UNDERWAY ALOFT TUES MORNING AND
EVENTUALLY DEVELOPING AT THE SURFACE AS SOUTHERLY WINDS PICK UP.
DEEP AND FRESHLY RELOADED SNOW COVER OVER THE AREA WILL UNDOUBTEDLY
RETARD THE WARM UP...BUT STILL THINK TEMPS SHOULD MANAGE TO CLIMB
ABOVE FREEZING MOST AREAS FOR THE FIRST TIME IN WEEKS TUES
AFTERNOON.
WEAK COLD FRONT MOVES THROUGH TUESDAY EVENING WITH LITTLE FANFARE
AND BARELY TIME FOR MUCH COLD AIR TO SEEP SOUTHWARD BEFORE WARM AIR
ADVECTION BEGINS AGAIN LATER WEDNESDAY IN ADVANCE OF LATE WEDNESDAY
NIGHT INTO THURSDAY`S WELL ADVERTISED BIG HULLABALOO. NOT
SURPRISINGLY GIVEN THE COMPLEXITY OF THE PATTERN AND DEALING WITH
PHASING ISSUES...MODELS HAVE FLOPPED BACK FROM THEIR PREVIOUS FLIP
WITH MORE EMPHASIS ON A STRENGTHENING SOUTHERN LOW LIFTING NORTHEAST
INTO THE GREAT LAKES. STILL SOME DIFFERENCES IN STRENGTH AND EXACT
TRACK...BUT ECMWF/GFS NOW AGREE ON TAKING A SFC LOW OVER NORTHERN
MISSOURI 18Z THURS NORTHEAST TO THE UPPER GREAT LAKES BY THURSDAY
NIGHT...WITH CONSIDERABLE DEEPEN OF THE LOW ALONG THE WAY. ECMWF AND
06Z NAM ARE STRONGER AND A BIT FARTHER NORTHWEST...BUT NAM/GFS/ECMWF
ALL HAVE THE SAME GENERAL IDEA.
FIRST FORECAST ISSUE WILL BE WEDNESDAY NIGHT AS INITIAL BATCH OF WAA
PRECIP BREAKS OUT AND LIFTS NORTH ACROSS THE AREA. MODEL QPF REMAINS
FAIRLY HIGH AND WITH SOME ELEVATED INSTABILITY ALSO EVIDENT IN THE
MODELS...CERTAINLY ENOUGH TO WARRANT A CONTINUED SLIGHT CHANCE
MENTION OF THUNDERSTORMS. THE BIGGEST PROBLEM WED NIGHT WILL BE HOW
FAST THE 2M TEMPS WARM UP. WHILE VERY STRONG WAA WILL BE TAKING
PLACE ALOFT...INITIALLY EASTERLY WINDS OVER THE AREA AND DEEP SNOW
PACK COULD ALLOW FOR A RATHER PROLONGED PERIOD OF FREEZING RAIN AND
AN ICING THREAT DEPENDING ON SFC TEMPS. MANY OF THE MODEL SUGGEST A
SURGE OF WARM LATE WEDNESDAY NIGHT...ESPECIALLY SOUTHERN CWA...BUT
ITS GOING TO BE CLOSE. ONLY A MATTER OF A COUPLE DEGREES COULD MEAN
THE DIFFERENCE BETWEEN A SIGNIFICANT ICING PROBLEM AND ALL RAIN AND
THIS FAR OUT IT REALLY IS ANYONE`S GUESS WHAT SIDE OF 32F ANY ONE
GIVEN AREA WILL END UP ON AS THE RAIN FALLS. CERTAINLY FARTHER NORTH
WOULD STAND THE BETTER CHANCE OF FREEZING RAIN...BUT THE ICING
POTENTIAL CANNOT BE RULED OUT EVEN OVER SOUTHERN PORTIONS OF THE CWA.
THIS LATEST SWING IN THE MODELS TOWARD A MORE AMPLIFIED SOUTHERN LOW
TRACKING NORTH IS BAD NEWS FOR IN THE HYDROLOGY DEPARTMENT. WHILE
NOT AS HORRIFYING AS THE NIGHTMARE SCENARIO THE ECMWF HAD BEEN
PAINTING A COUPLE DAYS AGO WITH 50 AND NEAR 60F DEWPOINTS TO THE
WISCONSIN LINE...THE LATEST GUIDANCE DOES DRAG THE 40F ISODROSOTHERM
FAR NORTH INTO THE AREA ON THURSDAY...WITH EVEN SOME 50F DEWPOINTS
FAR SOUTHERN CWA. THE HIGHER THE DEWPOINTS THE MORE RAPID THE SNOW
MELT WILL BE AND THE MORE OF A PROBLEM ANY MODERATE TO HEAVY RAIN
THAT FALLS WILL POSE THURSDAY. TEMPS LOOK TO CLIMB SAFELY ABOVE
FREEZING THURS AM EVEN NORTH TO THE WI BORDER ENDING THE FRZ RAIN
THREAT...BUT WITH PWATS PROGGED TO CLIMB TO OVER AN INCH (200-250%
OF NORMAL) THURSDAY THE POTENTIAL WILL EXIST FOR HEAVY RAINFALL.
HAVE ALREADY BEEN HARPING ON ALL THE HYDRO CONCERNS IN THE ESF
ISSUED FRIDAY AND UPDATED OVER THE WEEKEND AND REALLY NO BIG CHANGES
IN THINKING AT THIS POINT OTHER THAN TO SAY THE FLOOD POTENTIAL IS
LOOKING MORE OMINOUS THAN IT DID 24 HOURS AGO.
STRONG COLD FRONT LOOKS TO SWEEP THROUGH THURSDAY EVENING BRINGING
AN END TO THE RAIN AND POSSIBLE THUNDERSTORMS AND ALLOWING DRIER AND
COLDER AIR TO FILTER INTO THE REGION. WHILE COLDER AIR FILTERS IN
FOR THE WEEKEND WITH MEDIUM RANGE MODELS SUGGESTING ONE OR TWO
SYSTEM COULD AFFECT THE REGION WITH WHAT WOULD PROBABLY BE SOME
SNOWFALL. TIMING AND TRACK OF THESE LOWER AMPLITUDE WAVES ARE ALL
OVER THE PLACE IN THE MODELS SO ONLY CARRYING LOW CHANCES POPS FOR
NOW.
IZZI
&&
.HYDROLOGY...
LATEST MODEL GUIDANCE DOES LOOK MORE WORRISOME THAN IT DID 24
HOURS AGO REGARDING THE FLOOD POTENTIAL THURSDAY...POSSIBLY
LINGERING INTO THE WEEKEND. MORE DETAIL METEOROLOGICAL DISCUSSION
IS ABOVE. NO CHANGES REALLY TO THE PREVIOUS HYDROLOGICAL
DISCUSSION OTHER THAN SLIGHTLY MORE SNOW AND SNOW WATER
EQUIVALENT IS EXPECTED TO BE IN PLACE AFTER TODAY`S SNOW SYSTEM.
WILL FRESHEN UP THE ESF AGAIN THIS MORNING BUT NOT PLANNING ANY
BIG CHANGES.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTHEASTERLY WINDS BECOMING LIGHT AND VARIABLE LATE THIS
AFTERNOON/EARLY EVENING...THEN TURNING WESTERLY.
* PERIODS OF HEAVY SNOW WITH NEAR WHITEOUT CONDITIONS AT TIMES
WITH SNOW RATES IN EXCESS OF AN INCH PER HOUR AT TIMES.
* POTENTIAL FOR THUNDERSNOW.
BMD
//DISCUSSION...UPDATED 18Z...
GOING FORECAST SEEMS LARGELY ON TRACK FOR THE TERMINALS WITH
MODERATE TO HEAVY SNOW SPREADING NORTHEAST INTO THE REGION EARLY
THIS AFTERNOON AND UPSTREAM OBS SHOWING VSBY QUICKLY DROPPING TO 1/4
TO 1/2 MILE. NARROW CORRIDOR ON INSTABILITY AHEAD OF AN APPROACHING
F-GEN BAND CURRENTLY MOVING ACROSS THE RIVER STILL APPEARS TO BE THE
BEST CHANCE FOR THUNDER TO MOVE NEAR THE TERMINALS...THOUGH STILL
FAVORS AREAS JUST SOUTH OF DOWNTOWN CHICAGO. MDW MAY BE CLOSE BUT DO
NOT HAVE THE CONFIDENCE IN COVERAGE TO ADD AT THIS TIME. DRIER AIR
PUSHES INTO THE AREA BY LATE AFTERNOON/EARLY EVENING AND RATES
SHOULD TAPER...THEN FORCING ENDS ABRUPTLY MID EVENING. LINGERING LOW
LEVEL MOISTURE WILL RESULT IN LOWER MVFR OR PSBLY IFR CIGS HANGING
OUT OVERNIGHT...THOUGH EXPECT VFR CONDITIONS BY AROUND DAYBREAK
TOMORROW.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN WIND SPEEDS/DIRECTION & TIMING WIND SHIFT.
* HIGH CONFIDENCE IN VSBY FALLING TO 1/4SM OR LESS WITH SNOW RATES
IN EXCESS OF AN INCH PER HOUR AT TIMES.
* LOW CONFIDENCE IN THUNDERSNOW AT TERMINALS.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH WEDNESDAY...PREDOMINANTLY VFR.
WEDNESDAY NIGHT...RAIN OR FZRA DEVELOPING.
THURSDAY..RAIN/FOG/IFR LIKELY. FZRA POSSIBLE IN THE MORNING.
FRIDAY...VFR PROBABLE.
SATURDAY AND SUNDAY...SOME POTENTIAL FOR SNOW.
IZZI
&&
.MARINE...
324 AM CST
HAVE HOISTED A GALE WARNING FOR A LARGE PORTION OF CENTRAL LAKE
MICHIGAN FOR TODAY. THE DEEPER SFC LOW IN THE MODELS SHOULD RESULT
IN A PERIOD OF SOUTHEAST GALES THIS MORNING INTO THE EARLY AFTERNOON
BEFORE THE BAGGIER PRESSURE GRADIENT APPROACHES THE LAKE ASSOCIATED
WITH THE INVERTED TROUGH NORTH OF THE LOW TRACKING ACROSS DOWNSTATE
IL AND IN. BRIEF SHOT OF WESTERLY WINDS TONIGHT IN THE WAKE OF THE
TROUGH AND DEPARTING LOW BEFORE SOUTHERLY WINDS BEGIN TO REALLY
CRANK UP AGAIN ON TUESDAY AS ANOTHER STRONG LOW TRACK EAST ACROSS
THE SOUTHERN CANADIAN PRAIRIES. COULD BE BORDERLINE SOUTHERLY GALES
ON TUESDAY AFTERNOON AS WELL...BUT FOR NOW JUST STUCK WITH OCNL GALE
WORDING IN THE GLF AND WILL LET NEXT SHIFT GET ANOTHER LOOK BEFORE
DECIDING ON POSSIBLE GALE HEADLINES FOR TUESDAY.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032-ILZ039 UNTIL 6 PM MONDAY.
WINTER STORM WARNING...ILZ006-ILZ013-ILZ014-ILZ022-ILZ023-ILZ033
UNTIL 9 PM MONDAY.
IN...WINTER STORM WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
9 PM MONDAY.
LM...GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876 UNTIL 9 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1210 PM CST MON FEB 17 2014
.DISCUSSION...
330 AM CST
SHORT TERM (THROUGH TONIGHT)...
MAIN CONCERNS ARE WITH INCREASED POTENTIAL FOR A PERIOD OF HEAVY
SNOW THIS AFTERNOON FOR THE ENTIRE CWA WHICH COULD HAVE SIGNIFICANT
IMPACTS WITH WHITE OUT CONDITIONS UNDER POSSIBLE TWO TO THREE
INCH PER HOUR SNOWFALL RATES SOME OF WHICH COULD FALL UNDER
CONVECTIVE ELEMENTS...WITH AREA WIDE 4 TO 8 INCHES LIKELY AND SOME
ISOLATED AMOUNTS NEAR 10 INCHES DEFINITELY NOT OUT OF THE QUESTION.
IMPRESSIVE STRONG STORM ANTICIPATED TO TAKE SHAPE OVER THE AREA
LATER TODAY CAN BE OBSERVED ON SATELLITE IMAGERY...WITH MID/UPPER
LEVEL TROUGH CURRENTLY PUSHING EAST THROUGH THE NORTHERN PLAINS. OUT
AHEAD OF THIS SYSTEM...LATEST RAP ANALYSIS DEPICTING STRONG
ISENTROPIC ASCENT OCCURRING ACROSS THE ENTIRE REGION INCLUDING
LOCALLY OVER THE CWA. THIS HAS RESULTED IN PERSISTENT MID/HIGH LEVEL
CLOUD COVER TO STREAM OUT AHEAD OF THIS SYSTEM...WITH CURRENT RADAR
IMAGERY LIGHTING UP WITH SOME DECENT RETURNS. ALTHOUGH RATHER DRY
AIR IN PLACE HAS LIMITED ANY PRECIP TO REACH THE SURFACE AND
ANTICIPATE FOR THIS TO FURTHER BE THE CASE OVER THE NEXT COUPLE OF
HOURS. WHAT COULD BE EXPECTED IN THE NEAR TERM ARE SOME ISOLATED
FLURRIES PRIMARILY OVER THE NORTHWEST HALF OF THE CWA...WITH RFD
CURRENTLY REPORTING 9 MILES IN LIGHT SNOW. ISENTROPIC ASCENT WILL
CONTINUE THIS MORNING...WITH SHORT TERM GUIDANCE HINTING AT THE
POSSIBILITY FOR FURTHER PRECIP DEVELOPMENT ENTERING THE SOUTHWEST CWA
JUST AFTER THE 12Z TIME FRAME. PREVIOUSLY DISCUSSED WARMING/WARM
WEDGE STILL ANTICIPATED HERE THIS MORNING AND COULD INITIALLY BRING
A WINTRY MIX BUT STAYING CONFINED TO THE SOUTHERN HALF OF THE
CWA...PRIMARILY SOUTH OF THE I80 CORRIDOR. IF ANYTHING WERE TO OCCUR
DURING THIS TIME FRAME...ANTICIPATE IT TO BE ON THE LIGHTER SIDE
WITH THE PREVIOUSLY MENTIONED DRIER AIR STILL NEEDING TO BE
OVERCOME. NONETHELESS...WITH AN ANTICIPATED SLOWING TREND WITH THE
EVOLUTION OF TODAY`S SYSTEM...THIS WINTRY MIX COULD BE MORE PREVALENT
THAN PREVIOUSLY THOUGHT TO START THE PERIOD. SO HAVE INCLUDED CHANCE
ZR/IP IN THE GRIDS THROUGH 15Z.
CAN MAKE OUT TWO SEPARATE PIECES OF STRONG ENERGY TRAVERSING THE
MID LEVEL FLOW...NOW WITH ALL GUIDANCE IN STRONG AGREEMENT WITH THE
EVOLUTION OF THIS ENERGY AS IT APPROACHES THE REGION. ABOUT THE ONLY
DIFFERENCE AT THIS TIME IS SOME SLIGHT TIMING DIFFERENCES WITH THE
APPROACH OF THE BETTER FORCING/PRECIP LATER TODAY. A CONTINUED
SLOWER TREND HAS BEEN THE PREFERRED TREND HERE THIS MORNING...AND
HAVE DELAYED HIGHEST POPS TODAY. ALTHOUGH DID NOT OVERLY STRAY TOO
MUCH WITH THE PREVIOUSLY MENTIONED ISENTROPIC ASCENT AND POTENTIAL
PRECIP OUT AHEAD OF IT. HAVE CONTINUED THE MENTION IN THE GRIDS FOR
A MIX OF SLEET FOR LATER IN THE MORNING...MAINLY FOR THE SOUTHERN
TIER OF COUNTIES. ALTHOUGH THERMAL PROFILES WOULD BE SUPPORTIVE OF
THIS WINTRY MIX CONTINUING...HAVE LIMITED MENTION OF THIS MIX AS
BETTER FORCING SHOULD BE ARRIVING DURING THIS TIME. WHATEVER
LINGERING WARM WEDGE IN THE COLUMN WILL QUICKLY COOL THE COLUMN TO
THE WET BULB AS STRONG DYNAMIC FORCING ARRIVES...WITH ANY MIX
QUICKLY CHANGING OVER TO ALL SNOW.
ONCE AGAIN...ALL GUIDANCE POINTING AT SIGNIFICANT SNOWFALL RATES
BEGINNING AT SOON AS LATE MORNING FOR THE WESTERN CWA. TWO PIECES OF
ENERGY WILL PHASE TOGETHER BY EARLY AFTERNOON...WITH THIS MID/UPPER
LEVEL TROUGH BECOMING NEGATIVELY TILTED. AS THIS OCCURS...ATTENDANT
LOW TO DEEPEN AS IT MOVES THROUGH CENTRAL ILLINOIS WITH 850MB LOW
REALLY BEGINNING TO TAKE SHAPE. STRONG DYNAMICAL FORCING ASSOCIATED
WITH THIS MID LEVEL TROUGH AND SIGNIFICANT HEIGHT FALLS WILL ALLOW
FORCING TO SWING THROUGH THE CWA BY LATE MORNING INTO THE EARLY
AFTERNOON. ASSOCIATED FRONTOGENETICAL FORCING WILL LIKEWISE PUSH
EAST THROUGH THE AREA THIS AFTERNOON...WITH THE PRESENCE OF NEGATIVE
EPV. THIS PRESENCE OF BOTH SLANTWISE AND UPRIGHT MOTIONS ARE LEADING
FOR SOME REALLY IMPRESSIVE VERTICAL MOTION...WITH FORECAST OMEGA
AMONG ALL GUIDANCE SOME OF THE HIGHEST IVE OBSERVED IN SOME TIME.
THE STRONGEST VERTICAL MOTIONS ARE EXPECTED TO PUSH EAST TO WEST
ACROSS THE CWA INTO THE EARLY AFTERNOON TIME FRAME AND CONTINUING
THROUGH MID/LATE AFTERNOON...WITH FORCING CENTERED RIGHT IN THE
MIDDLE OF THE CWA. ALTHOUGH CURRENT FORECAST SNOW TOTALS ARE THE
HIGHEST IN THESE LOCATIONS...TOTALS DONT STRAY TOO MUCH FROM THE
AMOUNTS ACROSS THE REMAINING CWA. THIS IS IN DUE TO PART TO HOW
UNSTABLE THIS SYSTEM WILL BE...INCLUDING CONVECTIVE INSTABILITY.
BOTH NAM/GFS SHOWING IMPRESSIVE MUCAPE TO PUSH NORTHEAST THROUGH THE
CWA AS EARLY AS MID MORNING...AND THE BEGINNING STAGES OF THIS CAN
ALREADY BE OBSERVED TO OUR WEST/SOUTHWEST WITH LATEST RAP ANALYSIS
DEPICTING 100-200 J/KG OVER IOWA/MISSOURI/KANSAS. WITH SREF GUIDANCE
INDICATING HIGH PROBABILITIES OF AT LEAST 50-100 J/KG OF MUCAPE TO
MOVE OVERHEAD LATER TODAY...FEEL THAT THE NAM/GFS SOLUTION OF 100 TO
ALMOST 300 J/KG IS NOT OF THE QUESTION. THE PRESENCE OF THIS STRONG
FORCING...STRONG INSTABILITY AND ABUNDANCE OF MOISTURE NOT ONLY
LIKELY BEING PRESENT BUT ALSO COMING TOGETHER...HAS STEERED THE
FORECAST SIGNIFICANTLY MORE PESSIMISTIC THIS MORNING.
HEAVIEST SNOW...WHICH WILL FALL WITH HIGH INTENSITIES AND POSSIBLY
AT A RATE OF TWO TO THREE INCHES PER HOUR AT TIMES SHOULD ARRIVE THE
FAR WESTERN CWA BY MID/LATE MORNING...AND THEN SPREADING EAST
THROUGH THE REMAINING CWA BY EARLY AFTERNOON. EXPECT THESE HIGH
SNOWFALL INTENSITIES THROUGH MID TO LATE AFTERNOON...AND POSSIBLY
CONTINUE INTO THE EARLY EVENING FOR THE EASTERN THIRD OF THE CWA.
THIS HEAVY SNOW WILL QUICKLY ACCUMULATE ON ROADS WITH NEAR
VISIBILITY LIKELY UNDER THIS HEAVY SNOW...CREATING VERY HAZARDOUS
CONDITIONS. AS WAS MENTIONED PREVIOUSLY...THE HIGHEST TOTALS ARE IN
THE CWA ALIGNED WITH THE BETTER FORCING...BUT FEEL THAT ANY LACKING
FORCING WILL BE SUPPLEMENTED WITH THE CONVECTIVE NATURE OF THIS
SYSTEM. CONVECTIVE ALLOWING MODELS INDICATE THE PRESENCE OF THUNDER
BREAKING OUT BY EARLY AFTERNOON. ALTHOUGH GUIDANCE IS HINTING THAT
THIS WILL BE MORE PREFERRED ACROSS THE SOUTHERN CWA...WITH GUIDANCE
INDICATING INSTABILITY INTO SOUTHERN WISCONSIN...HAVE INCLUDED A
CHANCE FOR THUNDER IN THE GRIDS FOR THE ENTIRE CWA. ITS THESE
CONVECTIVE ELEMENTS WHICH COULD SUPPLEMENT HIGHER RATES AND
RESULTANT SNOWFALL TOTALS. SO FOR THE WARNING ISSUED
OVERNIGHT...WILL HAVE AREA WIDE 4 TO 8 INCHES WITH THE POSSIBILITY OF
SLIGHTLY HIGHER AMOUNTS NEAR 10 INCHES. IF THESE CONVECTIVE ELEMENTS
WERE TO MATERIALIZE...THEN AREAS DEFINITELY COULD OBSERVE THESE
HIGHER AMOUNTS. ALSO...ITS POSSIBLE THAT THESE AMOUNTS COULD BE
OBSERVED IN A 4-6 HOUR WINDOW. HAVE THE WARNING ENDING EARLY THIS
EVENING FOR THE WESTERN CWA AND THEN AT 3Z LATER THIS EVENING FOR
THE EASTERN CWA. IF LATER GUIDANCE THIS MORNING CONTINUES TO SUPPORT
CURRENT THINKING...SITUATION FORECAST TO UNFOLD LATER THIS AFTERNOON
WILL DEFINITELY BE SOMETHING TO NOT TAKE LIGHTLY.
RODRIGUEZ
LONG TERM (TUESDAY THROUGH SUNDAY)...
FAST ON THE HEELS OF TODAY`S DEPARTING SYSTEM WILL BE ANOTHER
NORTHERN STREAM SYSTEM TRACKING ACROSS SOUTHERN CANADA. VERY STRONG
WARM AIR ADVECTION WILL BE UNDERWAY ALOFT TUES MORNING AND
EVENTUALLY DEVELOPING AT THE SURFACE AS SOUTHERLY WINDS PICK UP.
DEEP AND FRESHLY RELOADED SNOW COVER OVER THE AREA WILL UNDOUBTEDLY
RETARD THE WARM UP...BUT STILL THINK TEMPS SHOULD MANAGE TO CLIMB
ABOVE FREEZING MOST AREAS FOR THE FIRST TIME IN WEEKS TUES
AFTERNOON.
WEAK COLD FRONT MOVES THROUGH TUESDAY EVENING WITH LITTLE FANFARE
AND BARELY TIME FOR MUCH COLD AIR TO SEEP SOUTHWARD BEFORE WARM AIR
ADVECTION BEGINS AGAIN LATER WEDNESDAY IN ADVANCE OF LATE WEDNESDAY
NIGHT INTO THURSDAY`S WELL ADVERTISED BIG HULLABALOO. NOT
SURPRISINGLY GIVEN THE COMPLEXITY OF THE PATTERN AND DEALING WITH
PHASING ISSUES...MODELS HAVE FLOPPED BACK FROM THEIR PREVIOUS FLIP
WITH MORE EMPHASIS ON A STRENGTHENING SOUTHERN LOW LIFTING NORTHEAST
INTO THE GREAT LAKES. STILL SOME DIFFERENCES IN STRENGTH AND EXACT
TRACK...BUT ECMWF/GFS NOW AGREE ON TAKING A SFC LOW OVER NORTHERN
MISSOURI 18Z THURS NORTHEAST TO THE UPPER GREAT LAKES BY THURSDAY
NIGHT...WITH CONSIDERABLE DEEPEN OF THE LOW ALONG THE WAY. ECMWF AND
06Z NAM ARE STRONGER AND A BIT FARTHER NORTHWEST...BUT NAM/GFS/ECMWF
ALL HAVE THE SAME GENERAL IDEA.
FIRST FORECAST ISSUE WILL BE WEDNESDAY NIGHT AS INITIAL BATCH OF WAA
PRECIP BREAKS OUT AND LIFTS NORTH ACROSS THE AREA. MODEL QPF REMAINS
FAIRLY HIGH AND WITH SOME ELEVATED INSTABILITY ALSO EVIDENT IN THE
MODELS...CERTAINLY ENOUGH TO WARRANT A CONTINUED SLIGHT CHANCE
MENTION OF THUNDERSTORMS. THE BIGGEST PROBLEM WED NIGHT WILL BE HOW
FAST THE 2M TEMPS WARM UP. WHILE VERY STRONG WAA WILL BE TAKING
PLACE ALOFT...INITIALLY EASTERLY WINDS OVER THE AREA AND DEEP SNOW
PACK COULD ALLOW FOR A RATHER PROLONGED PERIOD OF FREEZING RAIN AND
AN ICING THREAT DEPENDING ON SFC TEMPS. MANY OF THE MODEL SUGGEST A
SURGE OF WARM LATE WEDNESDAY NIGHT...ESPECIALLY SOUTHERN CWA...BUT
ITS GOING TO BE CLOSE. ONLY A MATTER OF A COUPLE DEGREES COULD MEAN
THE DIFFERENCE BETWEEN A SIGNIFICANT ICING PROBLEM AND ALL RAIN AND
THIS FAR OUT IT REALLY IS ANYONE`S GUESS WHAT SIDE OF 32F ANY ONE
GIVEN AREA WILL END UP ON AS THE RAIN FALLS. CERTAINLY FARTHER NORTH
WOULD STAND THE BETTER CHANCE OF FREEZING RAIN...BUT THE ICING
POTENTIAL CANNOT BE RULED OUT EVEN OVER SOUTHERN PORTIONS OF THE CWA.
THIS LATEST SWING IN THE MODELS TOWARD A MORE AMPLIFIED SOUTHERN LOW
TRACKING NORTH IS BAD NEWS FOR IN THE HYDROLOGY DEPARTMENT. WHILE
NOT AS HORRIFYING AS THE NIGHTMARE SCENARIO THE ECMWF HAD BEEN
PAINTING A COUPLE DAYS AGO WITH 50 AND NEAR 60F DEWPOINTS TO THE
WISCONSIN LINE...THE LATEST GUIDANCE DOES DRAG THE 40F ISODROSOTHERM
FAR NORTH INTO THE AREA ON THURSDAY...WITH EVEN SOME 50F DEWPOINTS
FAR SOUTHERN CWA. THE HIGHER THE DEWPOINTS THE MORE RAPID THE SNOW
MELT WILL BE AND THE MORE OF A PROBLEM ANY MODERATE TO HEAVY RAIN
THAT FALLS WILL POSE THURSDAY. TEMPS LOOK TO CLIMB SAFELY ABOVE
FREEZING THURS AM EVEN NORTH TO THE WI BORDER ENDING THE FRZ RAIN
THREAT...BUT WITH PWATS PROGGED TO CLIMB TO OVER AN INCH (200-250%
OF NORMAL) THURSDAY THE POTENTIAL WILL EXIST FOR HEAVY RAINFALL.
HAVE ALREADY BEEN HARPING ON ALL THE HYDRO CONCERNS IN THE ESF
ISSUED FRIDAY AND UPDATED OVER THE WEEKEND AND REALLY NO BIG CHANGES
IN THINKING AT THIS POINT OTHER THAN TO SAY THE FLOOD POTENTIAL IS
LOOKING MORE OMINOUS THAN IT DID 24 HOURS AGO.
STRONG COLD FRONT LOOKS TO SWEEP THROUGH THURSDAY EVENING BRINGING
AN END TO THE RAIN AND POSSIBLE THUNDERSTORMS AND ALLOWING DRIER AND
COLDER AIR TO FILTER INTO THE REGION. WHILE COLDER AIR FILTERS IN
FOR THE WEEKEND WITH MEDIUM RANGE MODELS SUGGESTING ONE OR TWO
SYSTEM COULD AFFECT THE REGION WITH WHAT WOULD PROBABLY BE SOME
SNOWFALL. TIMING AND TRACK OF THESE LOWER AMPLITUDE WAVES ARE ALL
OVER THE PLACE IN THE MODELS SO ONLY CARRYING LOW CHANCES POPS FOR
NOW.
IZZI
&&
.HYDROLOGY...
LATEST MODEL GUIDANCE DOES LOOK MORE WORRISOME THAN IT DID 24
HOURS AGO REGARDING THE FLOOD POTENTIAL THURSDAY...POSSIBLY
LINGERING INTO THE WEEKEND. MORE DETAIL METEOROLOGICAL DISCUSSION
IS ABOVE. NO CHANGES REALLY TO THE PREVIOUS HYDROLOGICAL
DISCUSSION OTHER THAN SLIGHTLY MORE SNOW AND SNOW WATER
EQUIVALENT IS EXPECTED TO BE IN PLACE AFTER TODAY`S SNOW SYSTEM.
WILL FRESHEN UP THE ESF AGAIN THIS MORNING BUT NOT PLANNING ANY
BIG CHANGES.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY SOUTHEASTERLY WINDS BECOMING LIGHT AND VARIABLE LATE THIS
AFTERNOON/EARLY EVENING...THEN TURNING WESTERLY.
* PERIODS OF HEAVY SNOW WITH NEAR WHITEOUT CONDITIONS AT TIMES
WITH SNOW RATES IN EXCESS OF AN INCH PER HOUR AT TIME.
* POTENTIAL FOR THUNDERSNOW.
BMD
//DISCUSSION...UPDATED 18Z...
GOING FORECAST SEEMS LARGELY ON TRACK FOR THE TERMINALS WITH
MODERATE TO HEAVY SNOW SPREADING NORTHEAST INTO THE REGION EARLY
THIS AFTERNOON AND UPSTREAM OBS SHOWING VSBY QUICKLY DROPPING TO 1/4
TO 1/2 MILE. NARROW CORRIDOR ON INSTABILITY AHEAD OF AN APPROACHING
F-GEN BAND CURRENTLY MOVING ACROSS THE RIVER STILL APPEARS TO BE THE
BEST CHANCE FOR THUNDER TO MOVE NEAR THE TERMINALS...THOUGH STILL
FAVORS AREAS JUST SOUTH OF DOWNTOWN CHICAGO. MDW MAY BE CLOSE BUT DO
NOT HAVE THE CONFIDENCE IN COVERAGE TO ADD AT THIS TIME. DRIER AIR
PUSHES INTO THE AREA BY LATE AFTERNOON/EARLY EVENING AND RATES
SHOULD TAPER...THEN FORCING ENDS ABRUPTLY MID EVENING. LINGERING LOW
LEVEL MOISTURE WILL RESULT IN LOWER MVFR OR PSBLY IFR CIGS HANGING
OUT OVERNIGHT...THOUGH EXPECT VFR CONDITIONS BY AROUND DAYBREAK
TOMORROW.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN WIND SPEEDS/DIRECTION & TIMING WIND SHIFT.
* HIGH CONFIDENCE IN VSBY FALLING TO 1/4SM OR LESS WITH SNOW RATES
IN EXCESS OF AN INCH PER HOUR AT TIMES...MEDIUM CONFIDENCE IN
TIMING.
* LOW CONFIDENCE IN THUNDERSNOW AT TERMINALS.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH WEDNESDAY...PREDOMINANTLY VFR.
WEDNESDAY NIGHT...RAIN OR FZRA DEVELOPING.
THURSDAY..RAIN/FOG/IFR LIKELY. FZRA POSSIBLE IN THE MORNING.
FRIDAY...VFR PROBABLE.
SATURDAY AND SUNDAY...SOME POTENTIAL FOR SNOW.
IZZI
&&
.MARINE...
324 AM CST
HAVE HOISTED A GALE WARNING FOR A LARGE PORTION OF CENTRAL LAKE
MICHIGAN FOR TODAY. THE DEEPER SFC LOW IN THE MODELS SHOULD RESULT
IN A PERIOD OF SOUTHEAST GALES THIS MORNING INTO THE EARLY AFTERNOON
BEFORE THE BAGGIER PRESSURE GRADIENT APPROACHES THE LAKE ASSOCIATED
WITH THE INVERTED TROUGH NORTH OF THE LOW TRACKING ACROSS DOWNSTATE
IL AND IN. BRIEF SHOT OF WESTERLY WINDS TONIGHT IN THE WAKE OF THE
TROUGH AND DEPARTING LOW BEFORE SOUTHERLY WINDS BEGIN TO REALLY
CRANK UP AGAIN ON TUESDAY AS ANOTHER STRONG LOW TRACK EAST ACROSS
THE SOUTHERN CANADIAN PRAIRIES. COULD BE BORDERLINE SOUTHERLY GALES
ON TUESDAY AFTERNOON AS WELL...BUT FOR NOW JUST STUCK WITH OCNL GALE
WORDING IN THE GLF AND WILL LET NEXT SHIFT GET ANOTHER LOOK BEFORE
DECIDING ON POSSIBLE GALE HEADLINES FOR TUESDAY.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032-ILZ039 UNTIL 6 PM MONDAY.
WINTER STORM WARNING...ILZ006-ILZ013-ILZ014-ILZ022-ILZ023-ILZ033
UNTIL 9 PM MONDAY.
IN...WINTER STORM WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
9 PM MONDAY.
LM...GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876 UNTIL 3 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1004 AM CST MON FEB 17 2014
.DISCUSSION...
330 AM CST
SHORT TERM (THROUGH TONIGHT)...
MAIN CONCERNS ARE WITH INCREASED POTENTIAL FOR A PERIOD OF HEAVY
SNOW THIS AFTERNOON FOR THE ENTIRE CWA WHICH COULD HAVE SIGNIFICANT
IMPACTS WITH WHITE OUT CONDITIONS UNDER POSSIBLE TWO TO THREE
INCH PER HOUR SNOWFALL RATES SOME OF WHICH COULD FALL UNDER
CONVECTIVE ELEMENTS...WITH AREA WIDE 4 TO 8 INCHES LIKELY AND SOME
ISOLATED AMOUNTS NEAR 10 INCHES DEFINITELY NOT OUT OF THE QUESTION.
IMPRESSIVE STRONG STORM ANTICIPATED TO TAKE SHAPE OVER THE AREA
LATER TODAY CAN BE OBSERVED ON SATELLITE IMAGERY...WITH MID/UPPER
LEVEL TROUGH CURRENTLY PUSHING EAST THROUGH THE NORTHERN PLAINS. OUT
AHEAD OF THIS SYSTEM...LATEST RAP ANALYSIS DEPICTING STRONG
ISENTROPIC ASCENT OCCURRING ACROSS THE ENTIRE REGION INCLUDING
LOCALLY OVER THE CWA. THIS HAS RESULTED IN PERSISTENT MID/HIGH LEVEL
CLOUD COVER TO STREAM OUT AHEAD OF THIS SYSTEM...WITH CURRENT RADAR
IMAGERY LIGHTING UP WITH SOME DECENT RETURNS. ALTHOUGH RATHER DRY
AIR IN PLACE HAS LIMITED ANY PRECIP TO REACH THE SURFACE AND
ANTICIPATE FOR THIS TO FURTHER BE THE CASE OVER THE NEXT COUPLE OF
HOURS. WHAT COULD BE EXPECTED IN THE NEAR TERM ARE SOME ISOLATED
FLURRIES PRIMARILY OVER THE NORTHWEST HALF OF THE CWA...WITH RFD
CURRENTLY REPORTING 9 MILES IN LIGHT SNOW. ISENTROPIC ASCENT WILL
CONTINUE THIS MORNING...WITH SHORT TERM GUIDANCE HINTING AT THE
POSSIBILITY FOR FURTHER PRECIP DEVELOPMENT ENTERING THE SOUTHWEST CWA
JUST AFTER THE 12Z TIME FRAME. PREVIOUSLY DISCUSSED WARMING/WARM
WEDGE STILL ANTICIPATED HERE THIS MORNING AND COULD INITIALLY BRING
A WINTRY MIX BUT STAYING CONFINED TO THE SOUTHERN HALF OF THE
CWA...PRIMARILY SOUTH OF THE I80 CORRIDOR. IF ANYTHING WERE TO OCCUR
DURING THIS TIME FRAME...ANTICIPATE IT TO BE ON THE LIGHTER SIDE
WITH THE PREVIOUSLY MENTIONED DRIER AIR STILL NEEDING TO BE
OVERCOME. NONETHELESS...WITH AN ANTICIPATED SLOWING TREND WITH THE
EVOLUTION OF TODAY`S SYSTEM...THIS WINTRY MIX COULD BE MORE PREVALENT
THAN PREVIOUSLY THOUGHT TO START THE PERIOD. SO HAVE INCLUDED CHANCE
ZR/IP IN THE GRIDS THROUGH 15Z.
CAN MAKE OUT TWO SEPARATE PIECES OF STRONG ENERGY TRAVERSING THE
MID LEVEL FLOW...NOW WITH ALL GUIDANCE IN STRONG AGREEMENT WITH THE
EVOLUTION OF THIS ENERGY AS IT APPROACHES THE REGION. ABOUT THE ONLY
DIFFERENCE AT THIS TIME IS SOME SLIGHT TIMING DIFFERENCES WITH THE
APPROACH OF THE BETTER FORCING/PRECIP LATER TODAY. A CONTINUED
SLOWER TREND HAS BEEN THE PREFERRED TREND HERE THIS MORNING...AND
HAVE DELAYED HIGHEST POPS TODAY. ALTHOUGH DID NOT OVERLY STRAY TOO
MUCH WITH THE PREVIOUSLY MENTIONED ISENTROPIC ASCENT AND POTENTIAL
PRECIP OUT AHEAD OF IT. HAVE CONTINUED THE MENTION IN THE GRIDS FOR
A MIX OF SLEET FOR LATER IN THE MORNING...MAINLY FOR THE SOUTHERN
TIER OF COUNTIES. ALTHOUGH THERMAL PROFILES WOULD BE SUPPORTIVE OF
THIS WINTRY MIX CONTINUING...HAVE LIMITED MENTION OF THIS MIX AS
BETTER FORCING SHOULD BE ARRIVING DURING THIS TIME. WHATEVER
LINGERING WARM WEDGE IN THE COLUMN WILL QUICKLY COOL THE COLUMN TO
THE WET BULB AS STRONG DYNAMIC FORCING ARRIVES...WITH ANY MIX
QUICKLY CHANGING OVER TO ALL SNOW.
ONCE AGAIN...ALL GUIDANCE POINTING AT SIGNIFICANT SNOWFALL RATES
BEGINNING AT SOON AS LATE MORNING FOR THE WESTERN CWA. TWO PIECES OF
ENERGY WILL PHASE TOGETHER BY EARLY AFTERNOON...WITH THIS MID/UPPER
LEVEL TROUGH BECOMING NEGATIVELY TILTED. AS THIS OCCURS...ATTENDANT
LOW TO DEEPEN AS IT MOVES THROUGH CENTRAL ILLINOIS WITH 850MB LOW
REALLY BEGINNING TO TAKE SHAPE. STRONG DYNAMICAL FORCING ASSOCIATED
WITH THIS MID LEVEL TROUGH AND SIGNIFICANT HEIGHT FALLS WILL ALLOW
FORCING TO SWING THROUGH THE CWA BY LATE MORNING INTO THE EARLY
AFTERNOON. ASSOCIATED FRONTOGENETICAL FORCING WILL LIKEWISE PUSH
EAST THROUGH THE AREA THIS AFTERNOON...WITH THE PRESENCE OF NEGATIVE
EPV. THIS PRESENCE OF BOTH SLANTWISE AND UPRIGHT MOTIONS ARE LEADING
FOR SOME REALLY IMPRESSIVE VERTICAL MOTION...WITH FORECAST OMEGA
AMONG ALL GUIDANCE SOME OF THE HIGHEST IVE OBSERVED IN SOME TIME.
THE STRONGEST VERTICAL MOTIONS ARE EXPECTED TO PUSH EAST TO WEST
ACROSS THE CWA INTO THE EARLY AFTERNOON TIME FRAME AND CONTINUING
THROUGH MID/LATE AFTERNOON...WITH FORCING CENTERED RIGHT IN THE
MIDDLE OF THE CWA. ALTHOUGH CURRENT FORECAST SNOW TOTALS ARE THE
HIGHEST IN THESE LOCATIONS...TOTALS DONT STRAY TOO MUCH FROM THE
AMOUNTS ACROSS THE REMAINING CWA. THIS IS IN DUE TO PART TO HOW
UNSTABLE THIS SYSTEM WILL BE...INCLUDING CONVECTIVE INSTABILITY.
BOTH NAM/GFS SHOWING IMPRESSIVE MUCAPE TO PUSH NORTHEAST THROUGH THE
CWA AS EARLY AS MID MORNING...AND THE BEGINNING STAGES OF THIS CAN
ALREADY BE OBSERVED TO OUR WEST/SOUTHWEST WITH LATEST RAP ANALYSIS
DEPICTING 100-200 J/KG OVER IOWA/MISSOURI/KANSAS. WITH SREF GUIDANCE
INDICATING HIGH PROBABILITIES OF AT LEAST 50-100 J/KG OF MUCAPE TO
MOVE OVERHEAD LATER TODAY...FEEL THAT THE NAM/GFS SOLUTION OF 100 TO
ALMOST 300 J/KG IS NOT OF THE QUESTION. THE PRESENCE OF THIS STRONG
FORCING...STRONG INSTABILITY AND ABUNDANCE OF MOISTURE NOT ONLY
LIKELY BEING PRESENT BUT ALSO COMING TOGETHER...HAS STEERED THE
FORECAST SIGNIFICANTLY MORE PESSIMISTIC THIS MORNING.
HEAVIEST SNOW...WHICH WILL FALL WITH HIGH INTENSITIES AND POSSIBLY
AT A RATE OF TWO TO THREE INCHES PER HOUR AT TIMES SHOULD ARRIVE THE
FAR WESTERN CWA BY MID/LATE MORNING...AND THEN SPREADING EAST
THROUGH THE REMAINING CWA BY EARLY AFTERNOON. EXPECT THESE HIGH
SNOWFALL INTENSITIES THROUGH MID TO LATE AFTERNOON...AND POSSIBLY
CONTINUE INTO THE EARLY EVENING FOR THE EASTERN THIRD OF THE CWA.
THIS HEAVY SNOW WILL QUICKLY ACCUMULATE ON ROADS WITH NEAR
VISIBILITY LIKELY UNDER THIS HEAVY SNOW...CREATING VERY HAZARDOUS
CONDITIONS. AS WAS MENTIONED PREVIOUSLY...THE HIGHEST TOTALS ARE IN
THE CWA ALIGNED WITH THE BETTER FORCING...BUT FEEL THAT ANY LACKING
FORCING WILL BE SUPPLEMENTED WITH THE CONVECTIVE NATURE OF THIS
SYSTEM. CONVECTIVE ALLOWING MODELS INDICATE THE PRESENCE OF THUNDER
BREAKING OUT BY EARLY AFTERNOON. ALTHOUGH GUIDANCE IS HINTING THAT
THIS WILL BE MORE PREFERRED ACROSS THE SOUTHERN CWA...WITH GUIDANCE
INDICATING INSTABILITY INTO SOUTHERN WISCONSIN...HAVE INCLUDED A
CHANCE FOR THUNDER IN THE GRIDS FOR THE ENTIRE CWA. ITS THESE
CONVECTIVE ELEMENTS WHICH COULD SUPPLEMENT HIGHER RATES AND
RESULTANT SNOWFALL TOTALS. SO FOR THE WARNING ISSUED
OVERNIGHT...WILL HAVE AREA WIDE 4 TO 8 INCHES WITH THE POSSIBILITY OF
SLIGHTLY HIGHER AMOUNTS NEAR 10 INCHES. IF THESE CONVECTIVE ELEMENTS
WERE TO MATERIALIZE...THEN AREAS DEFINITELY COULD OBSERVE THESE
HIGHER AMOUNTS. ALSO...ITS POSSIBLE THAT THESE AMOUNTS COULD BE
OBSERVED IN A 4-6 HOUR WINDOW. HAVE THE WARNING ENDING EARLY THIS
EVENING FOR THE WESTERN CWA AND THEN AT 3Z LATER THIS EVENING FOR
THE EASTERN CWA. IF LATER GUIDANCE THIS MORNING CONTINUES TO SUPPORT
CURRENT THINKING...SITUATION FORECAST TO UNFOLD LATER THIS AFTERNOON
WILL DEFINITELY BE SOMETHING TO NOT TAKE LIGHTLY.
RODRIGUEZ
LONG TERM (TUESDAY THROUGH SUNDAY)...
FAST ON THE HEELS OF TODAY`S DEPARTING SYSTEM WILL BE ANOTHER
NORTHERN STREAM SYSTEM TRACKING ACROSS SOUTHERN CANADA. VERY STRONG
WARM AIR ADVECTION WILL BE UNDERWAY ALOFT TUES MORNING AND
EVENTUALLY DEVELOPING AT THE SURFACE AS SOUTHERLY WINDS PICK UP.
DEEP AND FRESHLY RELOADED SNOW COVER OVER THE AREA WILL UNDOUBTEDLY
RETARD THE WARM UP...BUT STILL THINK TEMPS SHOULD MANAGE TO CLIMB
ABOVE FREEZING MOST AREAS FOR THE FIRST TIME IN WEEKS TUES
AFTERNOON.
WEAK COLD FRONT MOVES THROUGH TUESDAY EVENING WITH LITTLE FANFARE
AND BARELY TIME FOR MUCH COLD AIR TO SEEP SOUTHWARD BEFORE WARM AIR
ADVECTION BEGINS AGAIN LATER WEDNESDAY IN ADVANCE OF LATE WEDNESDAY
NIGHT INTO THURSDAY`S WELL ADVERTISED BIG HULLABALOO. NOT
SURPRISINGLY GIVEN THE COMPLEXITY OF THE PATTERN AND DEALING WITH
PHASING ISSUES...MODELS HAVE FLOPPED BACK FROM THEIR PREVIOUS FLIP
WITH MORE EMPHASIS ON A STRENGTHENING SOUTHERN LOW LIFTING NORTHEAST
INTO THE GREAT LAKES. STILL SOME DIFFERENCES IN STRENGTH AND EXACT
TRACK...BUT ECMWF/GFS NOW AGREE ON TAKING A SFC LOW OVER NORTHERN
MISSOURI 18Z THURS NORTHEAST TO THE UPPER GREAT LAKES BY THURSDAY
NIGHT...WITH CONSIDERABLE DEEPEN OF THE LOW ALONG THE WAY. ECMWF AND
06Z NAM ARE STRONGER AND A BIT FARTHER NORTHWEST...BUT NAM/GFS/ECMWF
ALL HAVE THE SAME GENERAL IDEA.
FIRST FORECAST ISSUE WILL BE WEDNESDAY NIGHT AS INITIAL BATCH OF WAA
PRECIP BREAKS OUT AND LIFTS NORTH ACROSS THE AREA. MODEL QPF REMAINS
FAIRLY HIGH AND WITH SOME ELEVATED INSTABILITY ALSO EVIDENT IN THE
MODELS...CERTAINLY ENOUGH TO WARRANT A CONTINUED SLIGHT CHANCE
MENTION OF THUNDERSTORMS. THE BIGGEST PROBLEM WED NIGHT WILL BE HOW
FAST THE 2M TEMPS WARM UP. WHILE VERY STRONG WAA WILL BE TAKING
PLACE ALOFT...INITIALLY EASTERLY WINDS OVER THE AREA AND DEEP SNOW
PACK COULD ALLOW FOR A RATHER PROLONGED PERIOD OF FREEZING RAIN AND
AN ICING THREAT DEPENDING ON SFC TEMPS. MANY OF THE MODEL SUGGEST A
SURGE OF WARM LATE WEDNESDAY NIGHT...ESPECIALLY SOUTHERN CWA...BUT
ITS GOING TO BE CLOSE. ONLY A MATTER OF A COUPLE DEGREES COULD MEAN
THE DIFFERENCE BETWEEN A SIGNIFICANT ICING PROBLEM AND ALL RAIN AND
THIS FAR OUT IT REALLY IS ANYONE`S GUESS WHAT SIDE OF 32F ANY ONE
GIVEN AREA WILL END UP ON AS THE RAIN FALLS. CERTAINLY FARTHER NORTH
WOULD STAND THE BETTER CHANCE OF FREEZING RAIN...BUT THE ICING
POTENTIAL CANNOT BE RULED OUT EVEN OVER SOUTHERN PORTIONS OF THE CWA.
THIS LATEST SWING IN THE MODELS TOWARD A MORE AMPLIFIED SOUTHERN LOW
TRACKING NORTH IS BAD NEWS FOR IN THE HYDROLOGY DEPARTMENT. WHILE
NOT AS HORRIFYING AS THE NIGHTMARE SCENARIO THE ECMWF HAD BEEN
PAINTING A COUPLE DAYS AGO WITH 50 AND NEAR 60F DEWPOINTS TO THE
WISCONSIN LINE...THE LATEST GUIDANCE DOES DRAG THE 40F ISODROSOTHERM
FAR NORTH INTO THE AREA ON THURSDAY...WITH EVEN SOME 50F DEWPOINTS
FAR SOUTHERN CWA. THE HIGHER THE DEWPOINTS THE MORE RAPID THE SNOW
MELT WILL BE AND THE MORE OF A PROBLEM ANY MODERATE TO HEAVY RAIN
THAT FALLS WILL POSE THURSDAY. TEMPS LOOK TO CLIMB SAFELY ABOVE
FREEZING THURS AM EVEN NORTH TO THE WI BORDER ENDING THE FRZ RAIN
THREAT...BUT WITH PWATS PROGGED TO CLIMB TO OVER AN INCH (200-250%
OF NORMAL) THURSDAY THE POTENTIAL WILL EXIST FOR HEAVY RAINFALL.
HAVE ALREADY BEEN HARPING ON ALL THE HYDRO CONCERNS IN THE ESF
ISSUED FRIDAY AND UPDATED OVER THE WEEKEND AND REALLY NO BIG CHANGES
IN THINKING AT THIS POINT OTHER THAN TO SAY THE FLOOD POTENTIAL IS
LOOKING MORE OMINOUS THAN IT DID 24 HOURS AGO.
STRONG COLD FRONT LOOKS TO SWEEP THROUGH THURSDAY EVENING BRINGING
AN END TO THE RAIN AND POSSIBLE THUNDERSTORMS AND ALLOWING DRIER AND
COLDER AIR TO FILTER INTO THE REGION. WHILE COLDER AIR FILTERS IN
FOR THE WEEKEND WITH MEDIUM RANGE MODELS SUGGESTING ONE OR TWO
SYSTEM COULD AFFECT THE REGION WITH WHAT WOULD PROBABLY BE SOME
SNOWFALL. TIMING AND TRACK OF THESE LOWER AMPLITUDE WAVES ARE ALL
OVER THE PLACE IN THE MODELS SO ONLY CARRYING LOW CHANCES POPS FOR
NOW.
IZZI
&&
.HYDROLOGY...
LATEST MODEL GUIDANCE DOES LOOK MORE WORRISOME THAN IT DID 24
HOURS AGO REGARDING THE FLOOD POTENTIAL THURSDAY...POSSIBLY
LINGERING INTO THE WEEKEND. MORE DETAIL METEOROLOGICAL DISCUSSION
IS ABOVE. NO CHANGES REALLY TO THE PREVIOUS HYDROLOGICAL
DISCUSSION OTHER THAN SLIGHTLY MORE SNOW AND SNOW WATER
EQUIVALENT IS EXPECTED TO BE IN PLACE AFTER TODAY`S SNOW SYSTEM.
WILL FRESHEN UP THE ESF AGAIN THIS MORNING BUT NOT PLANNING ANY
BIG CHANGES.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* HEAVY SNOW TO DEVELOP EARLY-MID AFTERNOON WITH OCNL VSBY BETWEEN
1/16SM AND 1/4SM EXPECTED
* SLIGHT CHANCE OF THUNDERSTORM (THUNDERSNOW) IN THE MID-LATE
AFTERNOON
* STRONG SOUTHEAST WINDS WITH GUSTS TO AROUND 25KT EXPECTED.
* QUICK IMPROVEMENT TO CIGS/VSBY AS SNOW ENDS EARLY THIS EVENING
IZZI/BMD
//DISCUSSION...UPDATED 12Z...
A SHORT LIVED BUT INTENSE SNOW STORM WILL AFFECT THE AREA TODAY.
RADAR ECHOS OVER DOWNSTATE ILLINOIS ARE INITIALLY EVAPORATING
BEFORE REACHING THE GROUND...BUT SNOW COULD BEGIN TO PENETRATE THE
LOW LEVEL DRY AIR AS EARLY AS MID MORNING...BUT MORE LIKELY BY
LATE MORNING AND DEFINITELY BY EARLY AFTERNOON. MOST INTENSE
SNOWFALL STILL LOOKS TO BE FOCUSED ON THE 19-23Z TIME FRAME FOR
CHICAGO AND ALL INDICATIONS ARE THAT VSBY WILL DROP AT TIMES TO AT
LEAST 1/4SM IF NOT LOWER WITH EVEN SOME THREAT OF +TSSN. SNOWFALL
RATES COULD EXCEED 2 INCHES PER HOUR AT TIMES. STRONG SOUTHEAST
WINDS THIS MORNING WILL DECREASE IN INTENSITY SOME AS THE SNOW
PEAKS THIS AFTERNOON...BUT DIRECTION LIKELY TO REMAIN SE THROUGH
MOST IF NOT ALL OF THE DURATION OF THE ACCUMULATING SNOW. INVERTED
TROUGH SHOULD MOVE THROUGH THIS EVENING RESULTING IN WIND SHIFT TO
WEST AND A QUICK WINDING DOWN OF THE SNOWFALL.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN ONSET TIME OF MOD-HVY SNOW +/- AN HOUR OR SO
* MEDIUM CONFIDENCE IN OCNL VSBY 1/4SM OR LOWER WITH ACCUMULATION
RATES OF 1"/HOUR OR GREATER
* MEDIUM-HIGH CONFIDENCE ON END TIME OF SNOW MONDAY EVENING +/- AN
HOUR OR SO
* HIGH CONFIDENCE IN REMAINDER OF FORECAST ELEMENTS
IZZI/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH WEDNESDAY...PREDOMINANTLY VFR.
WEDNESDAY NIGHT...RAIN OR FZRA DEVELOPING.
THURSDAY..RAIN/FOG/IFR LIKELY. FZRA POSSIBLE IN THE MORNING.
FRIDAY...VFR PROBABLE.
SATURDAY AND SUNDAY...SOME POTENTIAL FOR SNOW.
IZZI
&&
.MARINE...
324 AM CST
HAVE HOISTED A GALE WARNING FOR A LARGE PORTION OF CENTRAL LAKE
MICHIGAN FOR TODAY. THE DEEPER SFC LOW IN THE MODELS SHOULD RESULT
IN A PERIOD OF SOUTHEAST GALES THIS MORNING INTO THE EARLY AFTERNOON
BEFORE THE BAGGIER PRESSURE GRADIENT APPROACHES THE LAKE ASSOCIATED
WITH THE INVERTED TROUGH NORTH OF THE LOW TRACKING ACROSS DOWNSTATE
IL AND IN. BRIEF SHOT OF WESTERLY WINDS TONIGHT IN THE WAKE OF THE
TROUGH AND DEPARTING LOW BEFORE SOUTHERLY WINDS BEGIN TO REALLY
CRANK UP AGAIN ON TUESDAY AS ANOTHER STRONG LOW TRACK EAST ACROSS
THE SOUTHERN CANADIAN PRAIRIES. COULD BE BORDERLINE SOUTHERLY GALES
ON TUESDAY AFTERNOON AS WELL...BUT FOR NOW JUST STUCK WITH OCNL GALE
WORDING IN THE GLF AND WILL LET NEXT SHIFT GET ANOTHER LOOK BEFORE
DECIDING ON POSSIBLE GALE HEADLINES FOR TUESDAY.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032-ILZ039 UNTIL 6 PM MONDAY.
WINTER STORM WARNING...ILZ006-ILZ013-ILZ014-ILZ022-ILZ023-ILZ033
UNTIL 9 PM MONDAY.
IN...WINTER STORM WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
9 PM MONDAY.
LM...GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876 UNTIL 3 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
801 AM CST MON FEB 17 2014
.DISCUSSION...
330 AM CST
SHORT TERM (THROUGH TONIGHT)...
MAIN CONCERNS ARE WITH INCREASED POTENTIAL FOR A PERIOD OF HEAVY
SNOW THIS AFTERNOON FOR THE ENTIRE CWA WHICH COULD HAVE SIGNIFICANT
IMPACTS WITH WHITE OUT CONDITIONS UNDER POSSIBLE TWO TO THREE
INCH PER HOUR SNOWFALL RATES SOME OF WHICH COULD FALL UNDER
CONVECTIVE ELEMENTS...WITH AREA WIDE 4 TO 8 INCHES LIKELY AND SOME
ISOLATED AMOUNTS NEAR 10 INCHES DEFINITELY NOT OUT OF THE QUESTION.
IMPRESSIVE STRONG STORM ANTICIPATED TO TAKE SHAPE OVER THE AREA
LATER TODAY CAN BE OBSERVED ON SATELLITE IMAGERY...WITH MID/UPPER
LEVEL TROUGH CURRENTLY PUSHING EAST THROUGH THE NORTHERN PLAINS. OUT
AHEAD OF THIS SYSTEM...LATEST RAP ANALYSIS DEPICTING STRONG
ISENTROPIC ASCENT OCCURRING ACROSS THE ENTIRE REGION INCLUDING
LOCALLY OVER THE CWA. THIS HAS RESULTED IN PERSISTENT MID/HIGH LEVEL
CLOUD COVER TO STREAM OUT AHEAD OF THIS SYSTEM...WITH CURRENT RADAR
IMAGERY LIGHTING UP WITH SOME DECENT RETURNS. ALTHOUGH RATHER DRY
AIR IN PLACE HAS LIMITED ANY PRECIP TO REACH THE SURFACE AND
ANTICIPATE FOR THIS TO FURTHER BE THE CASE OVER THE NEXT COUPLE OF
HOURS. WHAT COULD BE EXPECTED IN THE NEAR TERM ARE SOME ISOLATED
FLURRIES PRIMARILY OVER THE NORTHWEST HALF OF THE CWA...WITH RFD
CURRENTLY REPORTING 9 MILES IN LIGHT SNOW. ISENTROPIC ASCENT WILL
CONTINUE THIS MORNING...WITH SHORT TERM GUIDANCE HINTING AT THE
POSSIBILITY FOR FURTHER PRECIP DEVELOPMENT ENTERING THE SOUTHWEST CWA
JUST AFTER THE 12Z TIME FRAME. PREVIOUSLY DISCUSSED WARMING/WARM
WEDGE STILL ANTICIPATED HERE THIS MORNING AND COULD INITIALLY BRING
A WINTRY MIX BUT STAYING CONFINED TO THE SOUTHERN HALF OF THE
CWA...PRIMARILY SOUTH OF THE I80 CORRIDOR. IF ANYTHING WERE TO OCCUR
DURING THIS TIME FRAME...ANTICIPATE IT TO BE ON THE LIGHTER SIDE
WITH THE PREVIOUSLY MENTIONED DRIER AIR STILL NEEDING TO BE
OVERCOME. NONETHELESS...WITH AN ANTICIPATED SLOWING TREND WITH THE
EVOLUTION OF TODAY`S SYSTEM...THIS WINTRY MIX COULD BE MORE PREVALENT
THAN PREVIOUSLY THOUGHT TO START THE PERIOD. SO HAVE INCLUDED CHANCE
ZR/IP IN THE GRIDS THROUGH 15Z.
CAN MAKE OUT TWO SEPARATE PIECES OF STRONG ENERGY TRAVERSING THE
MID LEVEL FLOW...NOW WITH ALL GUIDANCE IN STRONG AGREEMENT WITH THE
EVOLUTION OF THIS ENERGY AS IT APPROACHES THE REGION. ABOUT THE ONLY
DIFFERENCE AT THIS TIME IS SOME SLIGHT TIMING DIFFERENCES WITH THE
APPROACH OF THE BETTER FORCING/PRECIP LATER TODAY. A CONTINUED
SLOWER TREND HAS BEEN THE PREFERRED TREND HERE THIS MORNING...AND
HAVE DELAYED HIGHEST POPS TODAY. ALTHOUGH DID NOT OVERLY STRAY TOO
MUCH WITH THE PREVIOUSLY MENTIONED ISENTROPIC ASCENT AND POTENTIAL
PRECIP OUT AHEAD OF IT. HAVE CONTINUED THE MENTION IN THE GRIDS FOR
A MIX OF SLEET FOR LATER IN THE MORNING...MAINLY FOR THE SOUTHERN
TIER OF COUNTIES. ALTHOUGH THERMAL PROFILES WOULD BE SUPPORTIVE OF
THIS WINTRY MIX CONTINUING...HAVE LIMITED MENTION OF THIS MIX AS
BETTER FORCING SHOULD BE ARRIVING DURING THIS TIME. WHATEVER
LINGERING WARM WEDGE IN THE COLUMN WILL QUICKLY COOL THE COLUMN TO
THE WET BULB AS STRONG DYNAMIC FORCING ARRIVES...WITH ANY MIX
QUICKLY CHANGING OVER TO ALL SNOW.
ONCE AGAIN...ALL GUIDANCE POINTING AT SIGNIFICANT SNOWFALL RATES
BEGINNING AT SOON AS LATE MORNING FOR THE WESTERN CWA. TWO PIECES OF
ENERGY WILL PHASE TOGETHER BY EARLY AFTERNOON...WITH THIS MID/UPPER
LEVEL TROUGH BECOMING NEGATIVELY TILTED. AS THIS OCCURS...ATTENDANT
LOW TO DEEPEN AS IT MOVES THROUGH CENTRAL ILLINOIS WITH 850MB LOW
REALLY BEGINNING TO TAKE SHAPE. STRONG DYNAMICAL FORCING ASSOCIATED
WITH THIS MID LEVEL TROUGH AND SIGNIFICANT HEIGHT FALLS WILL ALLOW
FORCING TO SWING THROUGH THE CWA BY LATE MORNING INTO THE EARLY
AFTERNOON. ASSOCIATED FRONTOGENETICAL FORCING WILL LIKEWISE PUSH
EAST THROUGH THE AREA THIS AFTERNOON...WITH THE PRESENCE OF NEGATIVE
EPV. THIS PRESENCE OF BOTH SLANTWISE AND UPRIGHT MOTIONS ARE LEADING
FOR SOME REALLY IMPRESSIVE VERTICAL MOTION...WITH FORECAST OMEGA
AMONG ALL GUIDANCE SOME OF THE HIGHEST IVE OBSERVED IN SOME TIME.
THE STRONGEST VERTICAL MOTIONS ARE EXPECTED TO PUSH EAST TO WEST
ACROSS THE CWA INTO THE EARLY AFTERNOON TIME FRAME AND CONTINUING
THROUGH MID/LATE AFTERNOON...WITH FORCING CENTERED RIGHT IN THE
MIDDLE OF THE CWA. ALTHOUGH CURRENT FORECAST SNOW TOTALS ARE THE
HIGHEST IN THESE LOCATIONS...TOTALS DONT STRAY TOO MUCH FROM THE
AMOUNTS ACROSS THE REMAINING CWA. THIS IS IN DUE TO PART TO HOW
UNSTABLE THIS SYSTEM WILL BE...INCLUDING CONVECTIVE INSTABILITY.
BOTH NAM/GFS SHOWING IMPRESSIVE MUCAPE TO PUSH NORTHEAST THROUGH THE
CWA AS EARLY AS MID MORNING...AND THE BEGINNING STAGES OF THIS CAN
ALREADY BE OBSERVED TO OUR WEST/SOUTHWEST WITH LATEST RAP ANALYSIS
DEPICTING 100-200 J/KG OVER IOWA/MISSOURI/KANSAS. WITH SREF GUIDANCE
INDICATING HIGH PROBABILITIES OF AT LEAST 50-100 J/KG OF MUCAPE TO
MOVE OVERHEAD LATER TODAY...FEEL THAT THE NAM/GFS SOLUTION OF 100 TO
ALMOST 300 J/KG IS NOT OF THE QUESTION. THE PRESENCE OF THIS STRONG
FORCING...STRONG INSTABILITY AND ABUNDANCE OF MOISTURE NOT ONLY
LIKELY BEING PRESENT BUT ALSO COMING TOGETHER...HAS STEERED THE
FORECAST SIGNIFICANTLY MORE PESSIMISTIC THIS MORNING.
HEAVIEST SNOW...WHICH WILL FALL WITH HIGH INTENSITIES AND POSSIBLY
AT A RATE OF TWO TO THREE INCHES PER HOUR AT TIMES SHOULD ARRIVE THE
FAR WESTERN CWA BY MID/LATE MORNING...AND THEN SPREADING EAST
THROUGH THE REMAINING CWA BY EARLY AFTERNOON. EXPECT THESE HIGH
SNOWFALL INTENSITIES THROUGH MID TO LATE AFTERNOON...AND POSSIBLY
CONTINUE INTO THE EARLY EVENING FOR THE EASTERN THIRD OF THE CWA.
THIS HEAVY SNOW WILL QUICKLY ACCUMULATE ON ROADS WITH NEAR
VISIBILITY LIKELY UNDER THIS HEAVY SNOW...CREATING VERY HAZARDOUS
CONDITIONS. AS WAS MENTIONED PREVIOUSLY...THE HIGHEST TOTALS ARE IN
THE CWA ALIGNED WITH THE BETTER FORCING...BUT FEEL THAT ANY LACKING
FORCING WILL BE SUPPLEMENTED WITH THE CONVECTIVE NATURE OF THIS
SYSTEM. CONVECTIVE ALLOWING MODELS INDICATE THE PRESENCE OF THUNDER
BREAKING OUT BY EARLY AFTERNOON. ALTHOUGH GUIDANCE IS HINTING THAT
THIS WILL BE MORE PREFERRED ACROSS THE SOUTHERN CWA...WITH GUIDANCE
INDICATING INSTABILITY INTO SOUTHERN WISCONSIN...HAVE INCLUDED A
CHANCE FOR THUNDER IN THE GRIDS FOR THE ENTIRE CWA. ITS THESE
CONVECTIVE ELEMENTS WHICH COULD SUPPLEMENT HIGHER RATES AND
RESULTANT SNOWFALL TOTALS. SO FOR THE WARNING ISSUED
OVERNIGHT...WILL HAVE AREA WIDE 4 TO 8 INCHES WITH THE POSSIBILITY OF
SLIGHTLY HIGHER AMOUNTS NEAR 10 INCHES. IF THESE CONVECTIVE ELEMENTS
WERE TO MATERIALIZE...THEN AREAS DEFINITELY COULD OBSERVE THESE
HIGHER AMOUNTS. ALSO...ITS POSSIBLE THAT THESE AMOUNTS COULD BE
OBSERVED IN A 4-6 HOUR WINDOW. HAVE THE WARNING ENDING EARLY THIS
EVENING FOR THE WESTERN CWA AND THEN AT 3Z LATER THIS EVENING FOR
THE EASTERN CWA. IF LATER GUIDANCE THIS MORNING CONTINUES TO SUPPORT
CURRENT THINKING...SITUATION FORECAST TO UNFOLD LATER THIS AFTERNOON
WILL DEFINITELY BE SOMETHING TO NOT TAKE LIGHTLY.
RODRIGUEZ
LONG TERM (TUESDAY THROUGH SUNDAY)...
FAST ON THE HEELS OF TODAY`S DEPARTING SYSTEM WILL BE ANOTHER
NORTHERN STREAM SYSTEM TRACKING ACROSS SOUTHERN CANADA. VERY STRONG
WARM AIR ADVECTION WILL BE UNDERWAY ALOFT TUES MORNING AND
EVENTUALLY DEVELOPING AT THE SURFACE AS SOUTHERLY WINDS PICK UP.
DEEP AND FRESHLY RELOADED SNOW COVER OVER THE AREA WILL UNDOUBTEDLY
RETARD THE WARM UP...BUT STILL THINK TEMPS SHOULD MANAGE TO CLIMB
ABOVE FREEZING MOST AREAS FOR THE FIRST TIME IN WEEKS TUES
AFTERNOON.
WEAK COLD FRONT MOVES THROUGH TUESDAY EVENING WITH LITTLE FANFARE
AND BARELY TIME FOR MUCH COLD AIR TO SEEP SOUTHWARD BEFORE WARM AIR
ADVECTION BEGINS AGAIN LATER WEDNESDAY IN ADVANCE OF LATE WEDNESDAY
NIGHT INTO THURSDAY`S WELL ADVERTISED BIG HULLABALOO. NOT
SURPRISINGLY GIVEN THE COMPLEXITY OF THE PATTERN AND DEALING WITH
PHASING ISSUES...MODELS HAVE FLOPPED BACK FROM THEIR PREVIOUS FLIP
WITH MORE EMPHASIS ON A STRENGTHENING SOUTHERN LOW LIFTING NORTHEAST
INTO THE GREAT LAKES. STILL SOME DIFFERENCES IN STRENGTH AND EXACT
TRACK...BUT ECMWF/GFS NOW AGREE ON TAKING A SFC LOW OVER NORTHERN
MISSOURI 18Z THURS NORTHEAST TO THE UPPER GREAT LAKES BY THURSDAY
NIGHT...WITH CONSIDERABLE DEEPEN OF THE LOW ALONG THE WAY. ECMWF AND
06Z NAM ARE STRONGER AND A BIT FARTHER NORTHWEST...BUT NAM/GFS/ECMWF
ALL HAVE THE SAME GENERAL IDEA.
FIRST FORECAST ISSUE WILL BE WEDNESDAY NIGHT AS INITIAL BATCH OF WAA
PRECIP BREAKS OUT AND LIFTS NORTH ACROSS THE AREA. MODEL QPF REMAINS
FAIRLY HIGH AND WITH SOME ELEVATED INSTABILITY ALSO EVIDENT IN THE
MODELS...CERTAINLY ENOUGH TO WARRANT A CONTINUED SLIGHT CHANCE
MENTION OF THUNDERSTORMS. THE BIGGEST PROBLEM WED NIGHT WILL BE HOW
FAST THE 2M TEMPS WARM UP. WHILE VERY STRONG WAA WILL BE TAKING
PLACE ALOFT...INITIALLY EASTERLY WINDS OVER THE AREA AND DEEP SNOW
PACK COULD ALLOW FOR A RATHER PROLONGED PERIOD OF FREEZING RAIN AND
AN ICING THREAT DEPENDING ON SFC TEMPS. MANY OF THE MODEL SUGGEST A
SURGE OF WARM LATE WEDNESDAY NIGHT...ESPECIALLY SOUTHERN CWA...BUT
ITS GOING TO BE CLOSE. ONLY A MATTER OF A COUPLE DEGREES COULD MEAN
THE DIFFERENCE BETWEEN A SIGNIFICANT ICING PROBLEM AND ALL RAIN AND
THIS FAR OUT IT REALLY IS ANYONE`S GUESS WHAT SIDE OF 32F ANY ONE
GIVEN AREA WILL END UP ON AS THE RAIN FALLS. CERTAINLY FARTHER NORTH
WOULD STAND THE BETTER CHANCE OF FREEZING RAIN...BUT THE ICING
POTENTIAL CANNOT BE RULED OUT EVEN OVER SOUTHERN PORTIONS OF THE CWA.
THIS LATEST SWING IN THE MODELS TOWARD A MORE AMPLIFIED SOUTHERN LOW
TRACKING NORTH IS BAD NEWS FOR IN THE HYDROLOGY DEPARTMENT. WHILE
NOT AS HORRIFYING AS THE NIGHTMARE SCENARIO THE ECMWF HAD BEEN
PAINTING A COUPLE DAYS AGO WITH 50 AND NEAR 60F DEWPOINTS TO THE
WISCONSIN LINE...THE LATEST GUIDANCE DOES DRAG THE 40F ISODROSOTHERM
FAR NORTH INTO THE AREA ON THURSDAY...WITH EVEN SOME 50F DEWPOINTS
FAR SOUTHERN CWA. THE HIGHER THE DEWPOINTS THE MORE RAPID THE SNOW
MELT WILL BE AND THE MORE OF A PROBLEM ANY MODERATE TO HEAVY RAIN
THAT FALLS WILL POSE THURSDAY. TEMPS LOOK TO CLIMB SAFELY ABOVE
FREEZING THURS AM EVEN NORTH TO THE WI BORDER ENDING THE FRZ RAIN
THREAT...BUT WITH PWATS PROGGED TO CLIMB TO OVER AN INCH (200-250%
OF NORMAL) THURSDAY THE POTENTIAL WILL EXIST FOR HEAVY RAINFALL.
HAVE ALREADY BEEN HARPING ON ALL THE HYDRO CONCERNS IN THE ESF
ISSUED FRIDAY AND UPDATED OVER THE WEEKEND AND REALLY NO BIG CHANGES
IN THINKING AT THIS POINT OTHER THAN TO SAY THE FLOOD POTENTIAL IS
LOOKING MORE OMINOUS THAN IT DID 24 HOURS AGO.
STRONG COLD FRONT LOOKS TO SWEEP THROUGH THURSDAY EVENING BRINGING
AN END TO THE RAIN AND POSSIBLE THUNDERSTORMS AND ALLOWING DRIER AND
COLDER AIR TO FILTER INTO THE REGION. WHILE COLDER AIR FILTERS IN
FOR THE WEEKEND WITH MEDIUM RANGE MODELS SUGGESTING ONE OR TWO
SYSTEM COULD AFFECT THE REGION WITH WHAT WOULD PROBABLY BE SOME
SNOWFALL. TIMING AND TRACK OF THESE LOWER AMPLITUDE WAVES ARE ALL
OVER THE PLACE IN THE MODELS SO ONLY CARRYING LOW CHANCES POPS FOR
NOW.
IZZI
&&
.HYDROLOGY...330 AM CST
LATEST MODEL GUIDANCE DOES LOOK MORE WORRISOME THAN IT DID 24
HOURS AGO REGARDING THE FLOOD POTENTIAL THURSDAY...POSSIBLY
LINGERING INTO THE WEEKEND. MORE DETAIL METEOROLOGICAL DISCUSSION
IS ABOVE. NO CHANGES REALLY TO THE PREVIOUS HYDROLOGICAL
DISCUSSION OTHER THAN SLIGHTLY MORE SNOW AND SNOW WATER
EQUIVALENT IS EXPECTED TO BE IN PLACE AFTER TODAY`S SNOW SYSTEM.
WILL FRESHEN UP THE ESF AGAIN THIS MORNING BUT NOT PLANNING ANY
BIG CHANGES.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* BAND OF HEAVY SNOW THIS MORNING WITH VSBY LESS THAN A HALF MILE
POSSIBLE...NEAR WHITE-OUT VERY BRIEFLY POSSIBLE.
* HEAVY SNOW TO DEVELOP EARLY-MID AFTERNOON WITH OCNL VSBY BETWEEN
1/16SM AND 1/4SM EXPECTED
* SLIGHT CHANCE OF THUNDERSTORM (THUNDERSNOW) IN THE MID-LATE
AFTERNOON
* STRONG SOUTHEAST WINDS WITH GUSTS TO AROUND 25KT EXPECTED.
* QUICK IMPROVEMENT TO CIGS/VSBY AS SNOW ENDS EARLY THIS EVENING
IZZI/BMD
//DISCUSSION...UPDATED 12Z...
A SHORT LIVED BUT INTENSE SNOW STORM WILL AFFECT THE AREA TODAY.
RADAR ECHOS OVER DOWNSTATE ILLINOIS ARE INITIALLY EVAPORATING
BEFORE REACHING THE GROUND...BUT SNOW COULD BEGIN TO PENETRATE THE
LOW LEVEL DRY AIR AS EARLY AS MID MORNING...BUT MORE LIKELY BY
LATE MORNING AND DEFINITELY BY EARLY AFTERNOON. MOST INTENSE
SNOWFALL STILL LOOKS TO BE FOCUSED ON THE 19-23Z TIME FRAME FOR
CHICAGO AND ALL INDICATIONS ARE THAT VSBY WILL DROP AT TIMES TO AT
LEAST 1/4SM IF NOT LOWER WITH EVEN SOME THREAT OF +TSSN. SNOWFALL
RATES COULD EXCEED 2 INCHES PER HOUR AT TIMES. STRONG SOUTHEAST
WINDS THIS MORNING WILL DECREASE IN INTENSITY SOME AS THE SNOW
PEAKS THIS AFTERNOON...BUT DIRECTION LIKELY TO REMAIN SE THROUGH
MOST IF NOT ALL OF THE DURATION OF THE ACCUMULATING SNOW. INVERTED
TROUGH SHOULD MOVE THROUGH THIS EVENING RESULTING IN WIND SHIFT TO
WEST AND A QUICK WINDING DOWN OF THE SNOWFALL.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN VSBY AT LEAST AS LOW AS HALF MILE 1430-1530Z.
* HIGH CONFIDENCE IN ONSET TIME OF MOD-HVY SNOW +/- AN HOUR OR SO
* MEDIUM CONFIDENCE IN OCNL VSBY 1/4SM OR LOWER WITH ACCUMULATION
RATES OF 1"/HOUR OR GREATER
* MEDIUM-HIGH CONFIDENCE ON END TIME OF SNOW MONDAY EVENING +/- AN
HOUR OR SO
* HIGH CONFIDENCE IN REMAINDER OF FORECAST ELEMENTS
IZZI/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH WEDNESDAY...PREDOMINANTLY VFR.
WEDNESDAY NIGHT...RAIN OR FZRA DEVELOPING.
THURSDAY..RAIN/FOG/IFR LIKELY. FZRA POSSIBLE IN THE MORNING.
FRIDAY...VFR PROBABLE.
SATURDAY AND SUNDAY...SOME POTENTIAL FOR SNOW.
IZZI
&&
.MARINE...
324 AM CST
HAVE HOISTED A GALE WARNING FOR A LARGE PORTION OF CENTRAL LAKE
MICHIGAN FOR TODAY. THE DEEPER SFC LOW IN THE MODELS SHOULD RESULT
IN A PERIOD OF SOUTHEAST GALES THIS MORNING INTO THE EARLY AFTERNOON
BEFORE THE BAGGIER PRESSURE GRADIENT APPROACHES THE LAKE ASSOCIATED
WITH THE INVERTED TROUGH NORTH OF THE LOW TRACKING ACROSS DOWNSTATE
IL AND IN. BRIEF SHOT OF WESTERLY WINDS TONIGHT IN THE WAKE OF THE
TROUGH AND DEPARTING LOW BEFORE SOUTHERLY WINDS BEGIN TO REALLY
CRANK UP AGAIN ON TUESDAY AS ANOTHER STRONG LOW TRACK EAST ACROSS
THE SOUTHERN CANADIAN PRAIRIES. COULD BE BORDERLINE SOUTHERLY GALES
ON TUESDAY AFTERNOON AS WELL...BUT FOR NOW JUST STUCK WITH OCNL GALE
WORDING IN THE GLF AND WILL LET NEXT SHIFT GET ANOTHER LOOK BEFORE
DECIDING ON POSSIBLE GALE HEADLINES FOR TUESDAY.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032-ILZ039 UNTIL 6 PM MONDAY.
WINTER STORM WARNING...ILZ006-ILZ013-ILZ014-ILZ022-ILZ023-ILZ033
UNTIL 9 PM MONDAY.
IN...WINTER STORM WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
9 PM MONDAY.
LM...GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876 UNTIL 3 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
549 AM CST MON FEB 17 2014
.DISCUSSION...
330 AM CST
SHORT TERM (THROUGH TONIGHT)...
MAIN CONCERNS ARE WITH INCREASED POTENTIAL FOR A PERIOD OF HEAVY
SNOW THIS AFTERNOON FOR THE ENTIRE CWA WHICH COULD HAVE SIGNIFICANT
IMPACTS WITH WHITE OUT CONDITIONS UNDER POSSIBLE TWO TO THREE
INCH PER HOUR SNOWFALL RATES SOME OF WHICH COULD FALL UNDER
CONVECTIVE ELEMENTS...WITH AREA WIDE 4 TO 8 INCHES LIKELY AND SOME
ISOLATED AMOUNTS NEAR 10 INCHES DEFINITELY NOT OUT OF THE QUESTION.
IMPRESSIVE STRONG STORM ANTICIPATED TO TAKE SHAPE OVER THE AREA
LATER TODAY CAN BE OBSERVED ON SATELLITE IMAGERY...WITH MID/UPPER
LEVEL TROUGH CURRENTLY PUSHING EAST THROUGH THE NORTHERN PLAINS. OUT
AHEAD OF THIS SYSTEM...LATEST RAP ANALYSIS DEPICTING STRONG
ISENTROPIC ASCENT OCCURRING ACROSS THE ENTIRE REGION INCLUDING
LOCALLY OVER THE CWA. THIS HAS RESULTED IN PERSISTENT MID/HIGH LEVEL
CLOUD COVER TO STREAM OUT AHEAD OF THIS SYSTEM...WITH CURRENT RADAR
IMAGERY LIGHTING UP WITH SOME DECENT RETURNS. ALTHOUGH RATHER DRY
AIR IN PLACE HAS LIMITED ANY PRECIP TO REACH THE SURFACE AND
ANTICIPATE FOR THIS TO FURTHER BE THE CASE OVER THE NEXT COUPLE OF
HOURS. WHAT COULD BE EXPECTED IN THE NEAR TERM ARE SOME ISOLATED
FLURRIES PRIMARILY OVER THE NORTHWEST HALF OF THE CWA...WITH RFD
CURRENTLY REPORTING 9 MILES IN LIGHT SNOW. ISENTROPIC ASCENT WILL
CONTINUE THIS MORNING...WITH SHORT TERM GUIDANCE HINTING AT THE
POSSIBILITY FOR FURTHER PRECIP DEVELOPMENT ENTERING THE SOUTHWEST CWA
JUST AFTER THE 12Z TIME FRAME. PREVIOUSLY DISCUSSED WARMING/WARM
WEDGE STILL ANTICIPATED HERE THIS MORNING AND COULD INITIALLY BRING
A WINTRY MIX BUT STAYING CONFINED TO THE SOUTHERN HALF OF THE
CWA...PRIMARILY SOUTH OF THE I80 CORRIDOR. IF ANYTHING WERE TO OCCUR
DURING THIS TIME FRAME...ANTICIPATE IT TO BE ON THE LIGHTER SIDE
WITH THE PREVIOUSLY MENTIONED DRIER AIR STILL NEEDING TO BE
OVERCOME. NONETHELESS...WITH AN ANTICIPATED SLOWING TREND WITH THE
EVOLUTION OF TODAY`S SYSTEM...THIS WINTRY MIX COULD BE MORE PREVALENT
THAN PREVIOUSLY THOUGHT TO START THE PERIOD. SO HAVE INCLUDED CHANCE
ZR/IP IN THE GRIDS THROUGH 15Z.
CAN MAKE OUT TWO SEPARATE PIECES OF STRONG ENERGY TRAVERSING THE
MID LEVEL FLOW...NOW WITH ALL GUIDANCE IN STRONG AGREEMENT WITH THE
EVOLUTION OF THIS ENERGY AS IT APPROACHES THE REGION. ABOUT THE ONLY
DIFFERENCE AT THIS TIME IS SOME SLIGHT TIMING DIFFERENCES WITH THE
APPROACH OF THE BETTER FORCING/PRECIP LATER TODAY. A CONTINUED
SLOWER TREND HAS BEEN THE PREFERRED TREND HERE THIS MORNING...AND
HAVE DELAYED HIGHEST POPS TODAY. ALTHOUGH DID NOT OVERLY STRAY TOO
MUCH WITH THE PREVIOUSLY MENTIONED ISENTROPIC ASCENT AND POTENTIAL
PRECIP OUT AHEAD OF IT. HAVE CONTINUED THE MENTION IN THE GRIDS FOR
A MIX OF SLEET FOR LATER IN THE MORNING...MAINLY FOR THE SOUTHERN
TIER OF COUNTIES. ALTHOUGH THERMAL PROFILES WOULD BE SUPPORTIVE OF
THIS WINTRY MIX CONTINUING...HAVE LIMITED MENTION OF THIS MIX AS
BETTER FORCING SHOULD BE ARRIVING DURING THIS TIME. WHATEVER
LINGERING WARM WEDGE IN THE COLUMN WILL QUICKLY COOL THE COLUMN TO
THE WET BULB AS STRONG DYNAMIC FORCING ARRIVES...WITH ANY MIX
QUICKLY CHANGING OVER TO ALL SNOW.
ONCE AGAIN...ALL GUIDANCE POINTING AT SIGNIFICANT SNOWFALL RATES
BEGINNING AT SOON AS LATE MORNING FOR THE WESTERN CWA. TWO PIECES OF
ENERGY WILL PHASE TOGETHER BY EARLY AFTERNOON...WITH THIS MID/UPPER
LEVEL TROUGH BECOMING NEGATIVELY TILTED. AS THIS OCCURS...ATTENDANT
LOW TO DEEPEN AS IT MOVES THROUGH CENTRAL ILLINOIS WITH 850MB LOW
REALLY BEGINNING TO TAKE SHAPE. STRONG DYNAMICAL FORCING ASSOCIATED
WITH THIS MID LEVEL TROUGH AND SIGNIFICANT HEIGHT FALLS WILL ALLOW
FORCING TO SWING THROUGH THE CWA BY LATE MORNING INTO THE EARLY
AFTERNOON. ASSOCIATED FRONTOGENETICAL FORCING WILL LIKEWISE PUSH
EAST THROUGH THE AREA THIS AFTERNOON...WITH THE PRESENCE OF NEGATIVE
EPV. THIS PRESENCE OF BOTH SLANTWISE AND UPRIGHT MOTIONS ARE LEADING
FOR SOME REALLY IMPRESSIVE VERTICAL MOTION...WITH FORECAST OMEGA
AMONG ALL GUIDANCE SOME OF THE HIGHEST IVE OBSERVED IN SOME TIME.
THE STRONGEST VERTICAL MOTIONS ARE EXPECTED TO PUSH EAST TO WEST
ACROSS THE CWA INTO THE EARLY AFTERNOON TIME FRAME AND CONTINUING
THROUGH MID/LATE AFTERNOON...WITH FORCING CENTERED RIGHT IN THE
MIDDLE OF THE CWA. ALTHOUGH CURRENT FORECAST SNOW TOTALS ARE THE
HIGHEST IN THESE LOCATIONS...TOTALS DONT STRAY TOO MUCH FROM THE
AMOUNTS ACROSS THE REMAINING CWA. THIS IS IN DUE TO PART TO HOW
UNSTABLE THIS SYSTEM WILL BE...INCLUDING CONVECTIVE INSTABILITY.
BOTH NAM/GFS SHOWING IMPRESSIVE MUCAPE TO PUSH NORTHEAST THROUGH THE
CWA AS EARLY AS MID MORNING...AND THE BEGINNING STAGES OF THIS CAN
ALREADY BE OBSERVED TO OUR WEST/SOUTHWEST WITH LATEST RAP ANALYSIS
DEPICTING 100-200 J/KG OVER IOWA/MISSOURI/KANSAS. WITH SREF GUIDANCE
INDICATING HIGH PROBABILITIES OF AT LEAST 50-100 J/KG OF MUCAPE TO
MOVE OVERHEAD LATER TODAY...FEEL THAT THE NAM/GFS SOLUTION OF 100 TO
ALMOST 300 J/KG IS NOT OF THE QUESTION. THE PRESENCE OF THIS STRONG
FORCING...STRONG INSTABILITY AND ABUNDANCE OF MOISTURE NOT ONLY
LIKELY BEING PRESENT BUT ALSO COMING TOGETHER...HAS STEERED THE
FORECAST SIGNIFICANTLY MORE PESSIMISTIC THIS MORNING.
HEAVIEST SNOW...WHICH WILL FALL WITH HIGH INTENSITIES AND POSSIBLY
AT A RATE OF TWO TO THREE INCHES PER HOUR AT TIMES SHOULD ARRIVE THE
FAR WESTERN CWA BY MID/LATE MORNING...AND THEN SPREADING EAST
THROUGH THE REMAINING CWA BY EARLY AFTERNOON. EXPECT THESE HIGH
SNOWFALL INTENSITIES THROUGH MID TO LATE AFTERNOON...AND POSSIBLY
CONTINUE INTO THE EARLY EVENING FOR THE EASTERN THIRD OF THE CWA.
THIS HEAVY SNOW WILL QUICKLY ACCUMULATE ON ROADS WITH NEAR
VISIBILITY LIKELY UNDER THIS HEAVY SNOW...CREATING VERY HAZARDOUS
CONDITIONS. AS WAS MENTIONED PREVIOUSLY...THE HIGHEST TOTALS ARE IN
THE CWA ALIGNED WITH THE BETTER FORCING...BUT FEEL THAT ANY LACKING
FORCING WILL BE SUPPLEMENTED WITH THE CONVECTIVE NATURE OF THIS
SYSTEM. CONVECTIVE ALLOWING MODELS INDICATE THE PRESENCE OF THUNDER
BREAKING OUT BY EARLY AFTERNOON. ALTHOUGH GUIDANCE IS HINTING THAT
THIS WILL BE MORE PREFERRED ACROSS THE SOUTHERN CWA...WITH GUIDANCE
INDICATING INSTABILITY INTO SOUTHERN WISCONSIN...HAVE INCLUDED A
CHANCE FOR THUNDER IN THE GRIDS FOR THE ENTIRE CWA. ITS THESE
CONVECTIVE ELEMENTS WHICH COULD SUPPLEMENT HIGHER RATES AND
RESULTANT SNOWFALL TOTALS. SO FOR THE WARNING ISSUED
OVERNIGHT...WILL HAVE AREA WIDE 4 TO 8 INCHES WITH THE POSSIBILITY OF
SLIGHTLY HIGHER AMOUNTS NEAR 10 INCHES. IF THESE CONVECTIVE ELEMENTS
WERE TO MATERIALIZE...THEN AREAS DEFINITELY COULD OBSERVE THESE
HIGHER AMOUNTS. ALSO...ITS POSSIBLE THAT THESE AMOUNTS COULD BE
OBSERVED IN A 4-6 HOUR WINDOW. HAVE THE WARNING ENDING EARLY THIS
EVENING FOR THE WESTERN CWA AND THEN AT 3Z LATER THIS EVENING FOR
THE EASTERN CWA. IF LATER GUIDANCE THIS MORNING CONTINUES TO SUPPORT
CURRENT THINKING...SITUATION FORECAST TO UNFOLD LATER THIS AFTERNOON
WILL DEFINITELY BE SOMETHING TO NOT TAKE LIGHTLY.
RODRIGUEZ
LONG TERM (TUESDAY THROUGH SUNDAY)...
FAST ON THE HEELS OF TODAY`S DEPARTING SYSTEM WILL BE ANOTHER
NORTHERN STREAM SYSTEM TRACKING ACROSS SOUTHERN CANADA. VERY STRONG
WARM AIR ADVECTION WILL BE UNDERWAY ALOFT TUES MORNING AND
EVENTUALLY DEVELOPING AT THE SURFACE AS SOUTHERLY WINDS PICK UP.
DEEP AND FRESHLY RELOADED SNOW COVER OVER THE AREA WILL UNDOUBTEDLY
RETARD THE WARM UP...BUT STILL THINK TEMPS SHOULD MANAGE TO CLIMB
ABOVE FREEZING MOST AREAS FOR THE FIRST TIME IN WEEKS TUES
AFTERNOON.
WEAK COLD FRONT MOVES THROUGH TUESDAY EVENING WITH LITTLE FANFARE
AND BARELY TIME FOR MUCH COLD AIR TO SEEP SOUTHWARD BEFORE WARM AIR
ADVECTION BEGINS AGAIN LATER WEDNESDAY IN ADVANCE OF LATE WEDNESDAY
NIGHT INTO THURSDAY`S WELL ADVERTISED BIG HULLABALOO. NOT
SURPRISINGLY GIVEN THE COMPLEXITY OF THE PATTERN AND DEALING WITH
PHASING ISSUES...MODELS HAVE FLOPPED BACK FROM THEIR PREVIOUS FLIP
WITH MORE EMPHASIS ON A STRENGTHENING SOUTHERN LOW LIFTING NORTHEAST
INTO THE GREAT LAKES. STILL SOME DIFFERENCES IN STRENGTH AND EXACT
TRACK...BUT ECMWF/GFS NOW AGREE ON TAKING A SFC LOW OVER NORTHERN
MISSOURI 18Z THURS NORTHEAST TO THE UPPER GREAT LAKES BY THURSDAY
NIGHT...WITH CONSIDERABLE DEEPEN OF THE LOW ALONG THE WAY. ECMWF AND
06Z NAM ARE STRONGER AND A BIT FARTHER NORTHWEST...BUT NAM/GFS/ECMWF
ALL HAVE THE SAME GENERAL IDEA.
FIRST FORECAST ISSUE WILL BE WEDNESDAY NIGHT AS INITIAL BATCH OF WAA
PRECIP BREAKS OUT AND LIFTS NORTH ACROSS THE AREA. MODEL QPF REMAINS
FAIRLY HIGH AND WITH SOME ELEVATED INSTABILITY ALSO EVIDENT IN THE
MODELS...CERTAINLY ENOUGH TO WARRANT A CONTINUED SLIGHT CHANCE
MENTION OF THUNDERSTORMS. THE BIGGEST PROBLEM WED NIGHT WILL BE HOW
FAST THE 2M TEMPS WARM UP. WHILE VERY STRONG WAA WILL BE TAKING
PLACE ALOFT...INITIALLY EASTERLY WINDS OVER THE AREA AND DEEP SNOW
PACK COULD ALLOW FOR A RATHER PROLONGED PERIOD OF FREEZING RAIN AND
AN ICING THREAT DEPENDING ON SFC TEMPS. MANY OF THE MODEL SUGGEST A
SURGE OF WARM LATE WEDNESDAY NIGHT...ESPECIALLY SOUTHERN CWA...BUT
ITS GOING TO BE CLOSE. ONLY A MATTER OF A COUPLE DEGREES COULD MEAN
THE DIFFERENCE BETWEEN A SIGNIFICANT ICING PROBLEM AND ALL RAIN AND
THIS FAR OUT IT REALLY IS ANYONE`S GUESS WHAT SIDE OF 32F ANY ONE
GIVEN AREA WILL END UP ON AS THE RAIN FALLS. CERTAINLY FARTHER NORTH
WOULD STAND THE BETTER CHANCE OF FREEZING RAIN...BUT THE ICING
POTENTIAL CANNOT BE RULED OUT EVEN OVER SOUTHERN PORTIONS OF THE CWA.
THIS LATEST SWING IN THE MODELS TOWARD A MORE AMPLIFIED SOUTHERN LOW
TRACKING NORTH IS BAD NEWS FOR IN THE HYDROLOGY DEPARTMENT. WHILE
NOT AS HORRIFYING AS THE NIGHTMARE SCENARIO THE ECMWF HAD BEEN
PAINTING A COUPLE DAYS AGO WITH 50 AND NEAR 60F DEWPOINTS TO THE
WISCONSIN LINE...THE LATEST GUIDANCE DOES DRAG THE 40F ISODROSOTHERM
FAR NORTH INTO THE AREA ON THURSDAY...WITH EVEN SOME 50F DEWPOINTS
FAR SOUTHERN CWA. THE HIGHER THE DEWPOINTS THE MORE RAPID THE SNOW
MELT WILL BE AND THE MORE OF A PROBLEM ANY MODERATE TO HEAVY RAIN
THAT FALLS WILL POSE THURSDAY. TEMPS LOOK TO CLIMB SAFELY ABOVE
FREEZING THURS AM EVEN NORTH TO THE WI BORDER ENDING THE FRZ RAIN
THREAT...BUT WITH PWATS PROGGED TO CLIMB TO OVER AN INCH (200-250%
OF NORMAL) THURSDAY THE POTENTIAL WILL EXIST FOR HEAVY RAINFALL.
HAVE ALREADY BEEN HARPING ON ALL THE HYDRO CONCERNS IN THE ESF
ISSUED FRIDAY AND UPDATED OVER THE WEEKEND AND REALLY NO BIG CHANGES
IN THINKING AT THIS POINT OTHER THAN TO SAY THE FLOOD POTENTIAL IS
LOOKING MORE OMINOUS THAN IT DID 24 HOURS AGO.
STRONG COLD FRONT LOOKS TO SWEEP THROUGH THURSDAY EVENING BRINGING
AN END TO THE RAIN AND POSSIBLE THUNDERSTORMS AND ALLOWING DRIER AND
COLDER AIR TO FILTER INTO THE REGION. WHILE COLDER AIR FILTERS IN
FOR THE WEEKEND WITH MEDIUM RANGE MODELS SUGGESTING ONE OR TWO
SYSTEM COULD AFFECT THE REGION WITH WHAT WOULD PROBABLY BE SOME
SNOWFALL. TIMING AND TRACK OF THESE LOWER AMPLITUDE WAVES ARE ALL
OVER THE PLACE IN THE MODELS SO ONLY CARRYING LOW CHANCES POPS FOR
NOW.
IZZI
&&
.HYDROLOGY...
330 AM CST
LATEST MODEL GUIDANCE DOES LOOK MORE WORRISOME THAN IT DID 24
HOURS AGO REGARDING THE FLOOD POTENTIAL THURSDAY...POSSIBLY
LINGERING INTO THE WEEKEND. MORE DETAIL METEOROLOGICAL DISCUSSION
IS ABOVE. NO CHANGES REALLY TO THE PREVIOUS HYDROLOGICAL
DISCUSSION OTHER THAN SLIGHTLY MORE SNOW AND SNOW WATER
EQUIVALENT IS EXPECTED TO BE IN PLACE AFTER TODAY`S SNOW SYSTEM.
WILL FRESHEN UP THE ESF AGAIN THIS MORNING BUT NOT PLANNING ANY
BIG CHANGES.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* OCNL SNOW/IFR COULD DEVELOP WITH INITIAL WAVES OF SNOW MID-LATE
MORNING
* HEAVY SNOW TO DEVELOP EARLY-MID AFTERNOON WITH OCNL VSBY BETWEEN
1/16SM AND 1/4SM EXPECTED
* SLIGHT CHANCE OF THUNDERSTORM (THUNDERSNOW) IN THE MID-LATE
AFTERNOON
* STRONG SOUTHEAST WINDS DEVELOP DURING MORNING WITH GUSTS TO
AROUND 25KT EXPECTED...DIMINISHING AS HEAVY SNOW STARTS
* QUICK IMPROVEMENT TO CIGS/VSBY AS SNOW ENDS EARLY THIS EVENING
IZZI
//DISCUSSION...UPDATED 12Z...
A SHORT LIVED BUT INTENSE SNOW STORM WILL AFFECT THE AREA TODAY.
RADAR ECHOS OVER DOWNSTATE ILLINOIS ARE INITIALLY EVAPORATING
BEFORE REACHING THE GROUND...BUT SNOW COULD BEGIN TO PENETRATE THE
LOW LEVEL DRY AIR AS EARLY AS MID MORNING...BUT MORE LIKELY BY
LATE MORNING AND DEFINITELY BY EARLY AFTERNOON. MOST INTENSE
SNOWFALL STILL LOOKS TO BE FOCUSED ON THE 19-23Z TIME FRAME FOR
CHICAGO AND ALL INDICATIONS ARE THAT VSBY WILL DROP AT TIMES TO AT
LEAST 1/4SM IF NOT LOWER WITH EVEN SOME THREAT OF +TSSN. SNOWFALL
RATES COULD EXCEED 2 INCHES PER HOUR AT TIMES. STRONG SOUTHEAST
WINDS THIS MORNING WILL DECREASE IN INTENSITY SOME AS THE SNOW
PEAKS THIS AFTERNOON...BUT DIRECTION LIKELY TO REMAIN SE THROUGH
MOST IF NOT ALL OF THE DURATION OF THE ACCUMULATING SNOW. INVERTED
TROUGH SHOULD MOVE THROUGH THIS EVENING RESULTING IN WIND SHIFT TO
WEST AND A QUICK WINDING DOWN OF THE SNOWFALL.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* LOW-MEDIUM CONFIDENCE IN SNOW POTENTIAL MID-LATE MORNING
* HIGH CONFIDENCE IN ONSET TIME OF MOD-HVY SNOW +/- AN HOUR OR SO
* MEDIUM CONFIDENCE IN OCNL VSBY 1/4SM OR LOWER WITH ACCUMULATION
RATES OF 1"/HOUR OR GREATER
* MEDIUM-HIGH CONFIDENCE ON END TIME OF SNOW MONDAY EVENING +/- AN
HOUR OR SO
* HIGH CONFIDENCE IN REMAINDER OF FORECAST ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH WEDNESDAY...PREDOMINANTLY VFR.
WEDNESDAY NIGHT...RAIN OR FZRA DEVELOPING.
THURSDAY..RAIN/FOG/IFR LIKELY. FZRA POSSIBLE IN THE MORNING.
FRIDAY...VFR PROBABLE.
SATURDAY AND SUNDAY...SOME POTENTIAL FOR SNOW.
IZZI
&&
.MARINE...
324 AM CST
HAVE HOISTED A GALE WARNING FOR A LARGE PORTION OF CENTRAL LAKE
MICHIGAN FOR TODAY. THE DEEPER SFC LOW IN THE MODELS SHOULD RESULT
IN A PERIOD OF SOUTHEAST GALES THIS MORNING INTO THE EARLY AFTERNOON
BEFORE THE BAGGIER PRESSURE GRADIENT APPROACHES THE LAKE ASSOCIATED
WITH THE INVERTED TROUGH NORTH OF THE LOW TRACKING ACROSS DOWNSTATE
IL AND IN. BRIEF SHOT OF WESTERLY WINDS TONIGHT IN THE WAKE OF THE
TROUGH AND DEPARTING LOW BEFORE SOUTHERLY WINDS BEGIN TO REALLY
CRANK UP AGAIN ON TUESDAY AS ANOTHER STRONG LOW TRACK EAST ACROSS
THE SOUTHERN CANADIAN PRAIRIES. COULD BE BORDERLINE SOUTHERLY GALES
ON TUESDAY AFTERNOON AS WELL...BUT FOR NOW JUST STUCK WITH OCNL GALE
WORDING IN THE GLF AND WILL LET NEXT SHIFT GET ANOTHER LOOK BEFORE
DECIDING ON POSSIBLE GALE HEADLINES FOR TUESDAY.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032-ILZ039 UNTIL 6 PM MONDAY.
WINTER STORM WARNING...ILZ006-ILZ013-ILZ014-ILZ022-ILZ023-
ILZ033...9 AM MONDAY TO 9 PM MONDAY.
IN...WINTER STORM WARNING...INZ001-INZ002-INZ010-INZ011-INZ019...9 AM
MONDAY TO 9 PM MONDAY.
LM...GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876 UNTIL 3 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
409 AM CST MON FEB 17 2014
.DISCUSSION...
330 AM CST
SHORT TERM (THROUGH TONIGHT)...
MAIN CONCERNS ARE WITH INCREASED POTENTIAL FOR A PERIOD OF HEAVY
SNOW THIS AFTERNOON FOR THE ENTIRE CWA WHICH COULD HAVE SIGNIFICANT
IMPACTS WITH WHITE OUT CONDITIONS UNDER POSSIBLE TWO TO THREE
INCH PER HOUR SNOWFALL RATES SOME OF WHICH COULD FALL UNDER
CONVECTIVE ELEMENTS...WITH AREA WIDE 4 TO 8 INCHES LIKELY AND SOME
ISOLATED AMOUNTS NEAR 10 INCHES DEFINITELY NOT OUT OF THE QUESTION.
IMPRESSIVE STRONG STORM ANTICIPATED TO TAKE SHAPE OVER THE AREA
LATER TODAY CAN BE OBSERVED ON SATELLITE IMAGERY...WITH MID/UPPER
LEVEL TROUGH CURRENTLY PUSHING EAST THROUGH THE NORTHERN PLAINS. OUT
AHEAD OF THIS SYSTEM...LATEST RAP ANALYSIS DEPICTING STRONG
ISENTROPIC ASCENT OCCURRING ACROSS THE ENTIRE REGION INCLUDING
LOCALLY OVER THE CWA. THIS HAS RESULTED IN PERSISTENT MID/HIGH LEVEL
CLOUD COVER TO STREAM OUT AHEAD OF THIS SYSTEM...WITH CURRENT RADAR
IMAGERY LIGHTING UP WITH SOME DECENT RETURNS. ALTHOUGH RATHER DRY
AIR IN PLACE HAS LIMITED ANY PRECIP TO REACH THE SURFACE AND
ANTICIPATE FOR THIS TO FURTHER BE THE CASE OVER THE NEXT COUPLE OF
HOURS. WHAT COULD BE EXPECTED IN THE NEAR TERM ARE SOME ISOLATED
FLURRIES PRIMARILY OVER THE NORTHWEST HALF OF THE CWA...WITH RFD
CURRENTLY REPORTING 9 MILES IN LIGHT SNOW. ISENTROPIC ASCENT WILL
CONTINUE THIS MORNING...WITH SHORT TERM GUIDANCE HINTING AT THE
POSSIBILITY FOR FURTHER PRECIP DEVELOPMENT ENTERING THE SOUTHWEST CWA
JUST AFTER THE 12Z TIME FRAME. PREVIOUSLY DISCUSSED WARMING/WARM
WEDGE STILL ANTICIPATED HERE THIS MORNING AND COULD INITIALLY BRING
A WINTRY MIX BUT STAYING CONFINED TO THE SOUTHERN HALF OF THE
CWA...PRIMARILY SOUTH OF THE I80 CORRIDOR. IF ANYTHING WERE TO OCCUR
DURING THIS TIME FRAME...ANTICIPATE IT TO BE ON THE LIGHTER SIDE
WITH THE PREVIOUSLY MENTIONED DRIER AIR STILL NEEDING TO BE
OVERCOME. NONETHELESS...WITH AN ANTICIPATED SLOWING TREND WITH THE
EVOLUTION OF TODAY`S SYSTEM...THIS WINTRY MIX COULD BE MORE PREVALENT
THAN PREVIOUSLY THOUGHT TO START THE PERIOD. SO HAVE INCLUDED CHANCE
ZR/IP IN THE GRIDS THROUGH 15Z.
CAN MAKE OUT TWO SEPARATE PIECES OF STRONG ENERGY TRAVERSING THE
MID LEVEL FLOW...NOW WITH ALL GUIDANCE IN STRONG AGREEMENT WITH THE
EVOLUTION OF THIS ENERGY AS IT APPROACHES THE REGION. ABOUT THE ONLY
DIFFERENCE AT THIS TIME IS SOME SLIGHT TIMING DIFFERENCES WITH THE
APPROACH OF THE BETTER FORCING/PRECIP LATER TODAY. A CONTINUED
SLOWER TREND HAS BEEN THE PREFERRED TREND HERE THIS MORNING...AND
HAVE DELAYED HIGHEST POPS TODAY. ALTHOUGH DID NOT OVERLY STRAY TOO
MUCH WITH THE PREVIOUSLY MENTIONED ISENTROPIC ASCENT AND POTENTIAL
PRECIP OUT AHEAD OF IT. HAVE CONTINUED THE MENTION IN THE GRIDS FOR
A MIX OF SLEET FOR LATER IN THE MORNING...MAINLY FOR THE SOUTHERN
TIER OF COUNTIES. ALTHOUGH THERMAL PROFILES WOULD BE SUPPORTIVE OF
THIS WINTRY MIX CONTINUING...HAVE LIMITED MENTION OF THIS MIX AS
BETTER FORCING SHOULD BE ARRIVING DURING THIS TIME. WHATEVER
LINGERING WARM WEDGE IN THE COLUMN WILL QUICKLY COOL THE COLUMN TO
THE WET BULB AS STRONG DYNAMIC FORCING ARRIVES...WITH ANY MIX
QUICKLY CHANGING OVER TO ALL SNOW.
ONCE AGAIN...ALL GUIDANCE POINTING AT SIGNIFICANT SNOWFALL RATES
BEGINNING AT SOON AS LATE MORNING FOR THE WESTERN CWA. TWO PIECES OF
ENERGY WILL PHASE TOGETHER BY EARLY AFTERNOON...WITH THIS MID/UPPER
LEVEL TROUGH BECOMING NEGATIVELY TILTED. AS THIS OCCURS...ATTENDANT
LOW TO DEEPEN AS IT MOVES THROUGH CENTRAL ILLINOIS WITH 850MB LOW
REALLY BEGINNING TO TAKE SHAPE. STRONG DYNAMICAL FORCING ASSOCIATED
WITH THIS MID LEVEL TROUGH AND SIGNIFICANT HEIGHT FALLS WILL ALLOW
FORCING TO SWING THROUGH THE CWA BY LATE MORNING INTO THE EARLY
AFTERNOON. ASSOCIATED FRONTOGENETICAL FORCING WILL LIKEWISE PUSH
EAST THROUGH THE AREA THIS AFTERNOON...WITH THE PRESENCE OF NEGATIVE
EPV. THIS PRESENCE OF BOTH SLANTWISE AND UPRIGHT MOTIONS ARE LEADING
FOR SOME REALLY IMPRESSIVE VERTICAL MOTION...WITH FORECAST OMEGA
AMONG ALL GUIDANCE SOME OF THE HIGHEST IVE OBSERVED IN SOME TIME.
THE STRONGEST VERTICAL MOTIONS ARE EXPECTED TO PUSH EAST TO WEST
ACROSS THE CWA INTO THE EARLY AFTERNOON TIME FRAME AND CONTINUING
THROUGH MID/LATE AFTERNOON...WITH FORCING CENTERED RIGHT IN THE
MIDDLE OF THE CWA. ALTHOUGH CURRENT FORECAST SNOW TOTALS ARE THE
HIGHEST IN THESE LOCATIONS...TOTALS DONT STRAY TOO MUCH FROM THE
AMOUNTS ACROSS THE REMAINING CWA. THIS IS IN DUE TO PART TO HOW
UNSTABLE THIS SYSTEM WILL BE...INCLUDING CONVECTIVE INSTABILITY.
BOTH NAM/GFS SHOWING IMPRESSIVE MUCAPE TO PUSH NORTHEAST THROUGH THE
CWA AS EARLY AS MID MORNING...AND THE BEGINNING STAGES OF THIS CAN
ALREADY BE OBSERVED TO OUR WEST/SOUTHWEST WITH LATEST RAP ANALYSIS
DEPICTING 100-200 J/KG OVER IOWA/MISSOURI/KANSAS. WITH SREF GUIDANCE
INDICATING HIGH PROBABILITIES OF AT LEAST 50-100 J/KG OF MUCAPE TO
MOVE OVERHEAD LATER TODAY...FEEL THAT THE NAM/GFS SOLUTION OF 100 TO
ALMOST 300 J/KG IS NOT OF THE QUESTION. THE PRESENCE OF THIS STRONG
FORCING...STRONG INSTABILITY AND ABUNDANCE OF MOISTURE NOT ONLY
LIKELY BEING PRESENT BUT ALSO COMING TOGETHER...HAS STEERED THE
FORECAST SIGNIFICANTLY MORE PESSIMISTIC THIS MORNING.
HEAVIEST SNOW...WHICH WILL FALL WITH HIGH INTENSITIES AND POSSIBLY
AT A RATE OF TWO TO THREE INCHES PER HOUR AT TIMES SHOULD ARRIVE THE
FAR WESTERN CWA BY MID/LATE MORNING...AND THEN SPREADING EAST
THROUGH THE REMAINING CWA BY EARLY AFTERNOON. EXPECT THESE HIGH
SNOWFALL INTENSITIES THROUGH MID TO LATE AFTERNOON...AND POSSIBLY
CONTINUE INTO THE EARLY EVENING FOR THE EASTERN THIRD OF THE CWA.
THIS HEAVY SNOW WILL QUICKLY ACCUMULATE ON ROADS WITH NEAR
VISIBILITY LIKELY UNDER THIS HEAVY SNOW...CREATING VERY HAZARDOUS
CONDITIONS. AS WAS MENTIONED PREVIOUSLY...THE HIGHEST TOTALS ARE IN
THE CWA ALIGNED WITH THE BETTER FORCING...BUT FEEL THAT ANY LACKING
FORCING WILL BE SUPPLEMENTED WITH THE CONVECTIVE NATURE OF THIS
SYSTEM. CONVECTIVE ALLOWING MODELS INDICATE THE PRESENCE OF THUNDER
BREAKING OUT BY EARLY AFTERNOON. ALTHOUGH GUIDANCE IS HINTING THAT
THIS WILL BE MORE PREFERRED ACROSS THE SOUTHERN CWA...WITH GUIDANCE
INDICATING INSTABILITY INTO SOUTHERN WISCONSIN...HAVE INCLUDED A
CHANCE FOR THUNDER IN THE GRIDS FOR THE ENTIRE CWA. ITS THESE
CONVECTIVE ELEMENTS WHICH COULD SUPPLEMENT HIGHER RATES AND
RESULTANT SNOWFALL TOTALS. SO FOR THE WARNING ISSUED
OVERNIGHT...WILL HAVE AREA WIDE 4 TO 8 INCHES WITH THE POSSIBILITY OF
SLIGHTLY HIGHER AMOUNTS NEAR 10 INCHES. IF THESE CONVECTIVE ELEMENTS
WERE TO MATERIALIZE...THEN AREAS DEFINITELY COULD OBSERVE THESE
HIGHER AMOUNTS. ALSO...ITS POSSIBLE THAT THESE AMOUNTS COULD BE
OBSERVED IN A 4-6 HOUR WINDOW. HAVE THE WARNING ENDING EARLY THIS
EVENING FOR THE WESTERN CWA AND THEN AT 3Z LATER THIS EVENING FOR
THE EASTERN CWA. IF LATER GUIDANCE THIS MORNING CONTINUES TO SUPPORT
CURRENT THINKING...SITUATION FORECAST TO UNFOLD LATER THIS AFTERNOON
WILL DEFINITELY BE SOMETHING TO NOT TAKE LIGHTLY.
RODRIGUEZ
LONG TERM (TUESDAY THROUGH SUNDAY)...
FAST ON THE HEELS OF TODAY`S DEPARTING SYSTEM WILL BE ANOTHER
NORTHERN STREAM SYSTEM TRACKING ACROSS SOUTHERN CANADA. VERY STRONG
WARM AIR ADVECTION WILL BE UNDERWAY ALOFT TUES MORNING AND
EVENTUALLY DEVELOPING AT THE SURFACE AS SOUTHERLY WINDS PICK UP.
DEEP AND FRESHLY RELOADED SNOW COVER OVER THE AREA WILL UNDOUBTEDLY
RETARD THE WARM UP...BUT STILL THINK TEMPS SHOULD MANAGE TO CLIMB
ABOVE FREEZING MOST AREAS FOR THE FIRST TIME IN WEEKS TUES
AFTERNOON.
WEAK COLD FRONT MOVES THROUGH TUESDAY EVENING WITH LITTLE FANFARE
AND BARELY TIME FOR MUCH COLD AIR TO SEEP SOUTHWARD BEFORE WARM AIR
ADVECTION BEGINS AGAIN LATER WEDNESDAY IN ADVANCE OF LATE WEDNESDAY
NIGHT INTO THURSDAY`S WELL ADVERTISED BIG HULLABALOO. NOT
SURPRISINGLY GIVEN THE COMPLEXITY OF THE PATTERN AND DEALING WITH
PHASING ISSUES...MODELS HAVE FLOPPED BACK FROM THEIR PREVIOUS FLIP
WITH MORE EMPHASIS ON A STRENGTHENING SOUTHERN LOW LIFTING NORTHEAST
INTO THE GREAT LAKES. STILL SOME DIFFERENCES IN STRENGTH AND EXACT
TRACK...BUT ECMWF/GFS NOW AGREE ON TAKING A SFC LOW OVER NORTHERN
MISSOURI 18Z THURS NORTHEAST TO THE UPPER GREAT LAKES BY THURSDAY
NIGHT...WITH CONSIDERABLE DEEPEN OF THE LOW ALONG THE WAY. ECMWF AND
06Z NAM ARE STRONGER AND A BIT FARTHER NORTHWEST...BUT NAM/GFS/ECMWF
ALL HAVE THE SAME GENERAL IDEA.
FIRST FORECAST ISSUE WILL BE WEDNESDAY NIGHT AS INITIAL BATCH OF WAA
PRECIP BREAKS OUT AND LIFTS NORTH ACROSS THE AREA. MODEL QPF REMAINS
FAIRLY HIGH AND WITH SOME ELEVATED INSTABILITY ALSO EVIDENT IN THE
MODELS...CERTAINLY ENOUGH TO WARRANT A CONTINUED SLIGHT CHANCE
MENTION OF THUNDERSTORMS. THE BIGGEST PROBLEM WED NIGHT WILL BE HOW
FAST THE 2M TEMPS WARM UP. WHILE VERY STRONG WAA WILL BE TAKING
PLACE ALOFT...INITIALLY EASTERLY WINDS OVER THE AREA AND DEEP SNOW
PACK COULD ALLOW FOR A RATHER PROLONGED PERIOD OF FREEZING RAIN AND
AN ICING THREAT DEPENDING ON SFC TEMPS. MANY OF THE MODEL SUGGEST A
SURGE OF WARM LATE WEDNESDAY NIGHT...ESPECIALLY SOUTHERN CWA...BUT
ITS GOING TO BE CLOSE. ONLY A MATTER OF A COUPLE DEGREES COULD MEAN
THE DIFFERENCE BETWEEN A SIGNIFICANT ICING PROBLEM AND ALL RAIN AND
THIS FAR OUT IT REALLY IS ANYONE`S GUESS WHAT SIDE OF 32F ANY ONE
GIVEN AREA WILL END UP ON AS THE RAIN FALLS. CERTAINLY FARTHER NORTH
WOULD STAND THE BETTER CHANCE OF FREEZING RAIN...BUT THE ICING
POTENTIAL CANNOT BE RULED OUT EVEN OVER SOUTHERN PORTIONS OF THE CWA.
THIS LATEST SWING IN THE MODELS TOWARD A MORE AMPLIFIED SOUTHERN LOW
TRACKING NORTH IS BAD NEWS FOR IN THE HYDROLOGY DEPARTMENT. WHILE
NOT AS HORRIFYING AS THE NIGHTMARE SCENARIO THE ECMWF HAD BEEN
PAINTING A COUPLE DAYS AGO WITH 50 AND NEAR 60F DEWPOINTS TO THE
WISCONSIN LINE...THE LATEST GUIDANCE DOES DRAG THE 40F ISODROSOTHERM
FAR NORTH INTO THE AREA ON THURSDAY...WITH EVEN SOME 50F DEWPOINTS
FAR SOUTHERN CWA. THE HIGHER THE DEWPOINTS THE MORE RAPID THE SNOW
MELT WILL BE AND THE MORE OF A PROBLEM ANY MODERATE TO HEAVY RAIN
THAT FALLS WILL POSE THURSDAY. TEMPS LOOK TO CLIMB SAFELY ABOVE
FREEZING THURS AM EVEN NORTH TO THE WI BORDER ENDING THE FRZ RAIN
THREAT...BUT WITH PWATS PROGGED TO CLIMB TO OVER AN INCH (200-250%
OF NORMAL) THURSDAY THE POTENTIAL WILL EXIST FOR HEAVY RAINFALL.
HAVE ALREADY BEEN HARPING ON ALL THE HYDRO CONCERNS IN THE ESF
ISSUED FRIDAY AND UPDATED OVER THE WEEKEND AND REALLY NO BIG CHANGES
IN THINKING AT THIS POINT OTHER THAN TO SAY THE FLOOD POTENTIAL IS
LOOKING MORE OMINOUS THAN IT DID 24 HOURS AGO.
STRONG COLD FRONT LOOKS TO SWEEP THROUGH THURSDAY EVENING BRINGING
AN END TO THE RAIN AND POSSIBLE THUNDERSTORMS AND ALLOWING DRIER AND
COLDER AIR TO FILTER INTO THE REGION. WHILE COLDER AIR FILTERS IN
FOR THE WEEKEND WITH MEDIUM RANGE MODELS SUGGESTING ONE OR TWO
SYSTEM COULD AFFECT THE REGION WITH WHAT WOULD PROBABLY BE SOME
SNOWFALL. TIMING AND TRACK OF THESE LOWER AMPLITUDE WAVES ARE ALL
OVER THE PLACE IN THE MODELS SO ONLY CARRYING LOW CHANCES POPS FOR
NOW.
IZZI
&&
.HYDROLOGY...
330 AM CST
LATEST MODEL GUIDANCE DOES LOOK MORE WORRISOME THAN IT DID 24
HOURS AGO REGARDING THE FLOOD POTENTIAL THURSDAY...POSSIBLY
LINGERING INTO THE WEEKEND. MORE DETAIL METEOROLOGICAL DISCUSSION
IS ABOVE. NO CHANGES REALLY TO THE PREVIOUS HYDROLOGICAL
DISCUSSION OTHER THAN SLIGHTLY MORE SNOW AND SNOW WATER
EQUIVALENT IS EXPECTED TO BE IN PLACE AFTER TODAY`S SNOW SYSTEM.
WILL FRESHEN UP THE ESF AGAIN THIS MORNING BUT NOT PLANNING ANY
BIG CHANGES.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* CHANCE FOR SNOW SHOWERS BY MID TO LATE MORNING
* HEAVY SNOW TO DEVELOP EARLY-MID AFTERNOON WITH OCNL VSBY BETWEEN
1/16SM AND 1/4SM EXPECTED
* SLIGHT CHANCE OF THUNDERSTORM (THUNDERSNOW) IN THE MID-LATE
AFTERNOON
* STRONG SOUTHEAST WINDS DEVELOP DURING MORNING WITH GUSTS TO
AROUND 25KT EXPECTED...DIMINISHING AS HEAVY SNOW STARTS
* QUICK IMPROVEMENT TO CIGS/VSBY AS SNOW ENDS EARLY THIS EVENING
IZZI
//DISCUSSION...UPDATED 09Z...
ONLY NOTABLE CHANGE TO PREVIOUS TAFS WAS TO INCLUDE A TEMPO FOR
LIGHT SNOW MID-LATE MORNING. LOW LEVELS REMAIN DRY BUT FAIRLY
EXTENSIVE VIRGA (SOME RATHER INTENSE ECHOS) SHOWING UP ON RADAR
AND AM CONCERNED THAT CONTINUED PRECIPITATING INTO THE DRY WILL
MOISTEN THINGS UP ENOUGH FOR SNOW TO DEVELOP. HEAVIEST SNOW BY FAR
IS EXPECTED TO BE THIS AFTERNOON...BUT WORRIED THAT THERE COULD
STILL BE SOME PERIODIC IFR LIGHT SNOW MID-LATE MORNING AHEAD OF
THE BIG HULLABALOO.
IZZI
UPDATED 06Z...
LAKE EFFECT MVFR CIGS LIKELY TO PERSIST FOR AT LEAST A FEW MORE
HOURS OVERNIGHT BEFORE PROBABLY BREAKING UP LATE. CONTINUE TO SEE
SOME MODELS STARTING UP SNOW SHOWERS DURING THE MORNING HOURS
MONDAY...WHICH IF IT WERE TO HAPPEN COULD RESULT IN A MUCH EARLIER
ONSET TO IFR CONDITIONS THAN INDICATED IN THE CURRENT TAFS.
HANDLING THIS WITH A VCSH IN THE TAFS AND WILL MONITOR
RADAR/SATELLITE TRENDS THIS MORNING AND RE-ACCESS LATER. STRONG
PRESSURE FALLS TO OUR WEST IN RESPONSE TO THE DEVELOPING LOW WILL
RESULT IN A QUICK RAMP UP OF SOUTHEAST WINDS EARLY MONDAY MORNING
WITH GUSTS OF 25-30KT EXPECTED BY MID-LATE MORNING.
BIG STORY WILL BE THE INTENSE SNOW EXPECTED TO DEVELOP MONDAY
AFTERNOON. ALL INDICATIONS ARE THAT 3 TO 6 HOUR LONG WINDOW OF
MODERATE TO HEAVY SNOW WILL OCCUR MONDAY AFTERNOON. GETTING FAIRLY
STRONG SIGNALS IN THE MODELS TO SUPPORT PERIODIC VERY HEAVY
SNOWFALL WITH EVEN A SMALL CHANCE OF ISOLATED THUNDERSTORMS.
WINDS WILL SUBSIDE AS SNOW BEGINS BUT WITH SNOWFALL RATES OF AT
LEAST AN INCH PER HOUR LIKELY AND CRIPPLING RATES OF 2"+ PER HOUR
POSSIBLE THE DECREASING WINDS WILL BE A BIT OF A MOOT POINT.
CONDITIONS ARE LIKELY TO QUICKLY IMPROVE AS THE TROUGH MOVES
THROUGH EARLY MONDAY EVENING. WINDS WILL SHIFT TO WESTERLY AND
THERE WILL PROBABLY BE SEVERAL HOURS OF LINGER MVFR CIGS INTO THE
EVENING HOURS.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* LOW CONFIDENCE IN SNOW POTENTIAL BETWEEN 14-18Z THIS MORNING
* HIGH CONFIDENCE IN ONSET TIME OF MOD-HVY SNOW +/- AN HOUR OR SO
* MEDIUM CONFIDENCE IN OCNL VSBY 1/4SM OR LOWER WITH ACCUMULATION
RATES OF 1"/HOUR OR GREATER
* MEDIUM-HIGH CONFIDENCE ON END TIME OF SNOW MONDAY EVENING +/- AN
HOUR OR SO
* HIGH CONFIDENCE IN REMAINDER OF FORECAST ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY AND WEDNESDAY...PREDOMINANTLY VFR.
THURSDAY...RAIN/FOG/IFR LIKELY. FZRA POSSIBLE IN THE MORNING.
FRIDAY...VFR PROBABLE.
SATURDAY...CHANCE OF RA OR SN.
MDB
&&
.MARINE...
324 AM CST
HAVE HOISTED A GALE WARNING FOR A LARGE PORTION OF CENTRAL LAKE
MICHIGAN FOR TODAY. THE DEEPER SFC LOW IN THE MODELS SHOULD RESULT
IN A PERIOD OF SOUTHEAST GALES THIS MORNING INTO THE EARLY AFTERNOON
BEFORE THE BAGGIER PRESSURE GRADIENT APPROACHES THE LAKE ASSOCIATED
WITH THE INVERTED TROUGH NORTH OF THE LOW TRACKING ACROSS DOWNSTATE
IL AND IN. BRIEF SHOT OF WESTERLY WINDS TONIGHT IN THE WAKE OF THE
TROUGH AND DEPARTING LOW BEFORE SOUTHERLY WINDS BEGIN TO REALLY
CRANK UP AGAIN ON TUESDAY AS ANOTHER STRONG LOW TRACK EAST ACROSS
THE SOUTHERN CANADIAN PRAIRIES. COULD BE BORDERLINE SOUTHERLY GALES
ON TUESDAY AFTERNOON AS WELL...BUT FOR NOW JUST STUCK WITH OCNL GALE
WORDING IN THE GLF AND WILL LET NEXT SHIFT GET ANOTHER LOOK BEFORE
DECIDING ON POSSIBLE GALE HEADLINES FOR TUESDAY.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032-ILZ039 UNTIL 6 PM MONDAY.
WINTER STORM WARNING...ILZ006-ILZ013-ILZ014-ILZ022-ILZ023-
ILZ033...9 AM MONDAY TO 9 PM MONDAY.
IN...WINTER STORM WARNING...INZ001-INZ002-INZ010-INZ011-INZ019...9 AM
MONDAY TO 9 PM MONDAY.
LM...GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876...8 AM MONDAY TO 3 PM
MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
330 AM CST MON FEB 17 2014
.DISCUSSION...
330 AM CST
SHORT TERM (THROUGH TONIGHT)...
MAIN CONCERNS ARE WITH INCREASED POTENTIAL FOR A PERIOD OF HEAVY
SNOW THIS AFTERNOON FOR THE ENTIRE CWA WHICH COULD HAVE SIGNIFICANT
IMPACTS WITH WHITE OUT CONDITIONS UNDER POSSIBLE TWO TO THREE
INCH PER HOUR SNOWFALL RATES SOME OF WHICH COULD FALL UNDER
CONVECTIVE ELEMENTS...WITH AREA WIDE 4 TO 8 INCHES LIKELY AND SOME
ISOLATED AMOUNTS NEAR 10 INCHES DEFINITELY NOT OUT OF THE QUESTION.
IMPRESSIVE STRONG STORM ANTICIPATED TO TAKE SHAPE OVER THE AREA
LATER TODAY CAN BE OBSERVED ON SATELLITE IMAGERY...WITH MID/UPPER
LEVEL TROUGH CURRENTLY PUSHING EAST THROUGH THE NORTHERN PLAINS. OUT
AHEAD OF THIS SYSTEM...LATEST RAP ANALYSIS DEPICTING STRONG
ISENTROPIC ASCENT OCCURRING ACROSS THE ENTIRE REGION INCLUDING
LOCALLY OVER THE CWA. THIS HAS RESULTED IN PERSISTENT MID/HIGH LEVEL
CLOUD COVER TO STREAM OUT AHEAD OF THIS SYSTEM...WITH CURRENT RADAR
IMAGERY LIGHTING UP WITH SOME DECENT RETURNS. ALTHOUGH RATHER DRY
AIR IN PLACE HAS LIMITED ANY PRECIP TO REACH THE SURFACE AND
ANTICIPATE FOR THIS TO FURTHER BE THE CASE OVER THE NEXT COUPLE OF
HOURS. WHAT COULD BE EXPECTED IN THE NEAR TERM ARE SOME ISOLATED
FLURRIES PRIMARILY OVER THE NORTHWEST HALF OF THE CWA...WITH RFD
CURRENTLY REPORTING 9 MILES IN LIGHT SNOW. ISENTROPIC ASCENT WILL
CONTINUE THIS MORNING...WITH SHORT TERM GUIDANCE HINTING AT THE
POSSIBILITY FOR FURTHER PRECIP DEVELOPMENT ENTERING THE SOUTHWEST CWA
JUST AFTER THE 12Z TIME FRAME. PREVIOUSLY DISCUSSED WARMING/WARM
WEDGE STILL ANTICIPATED HERE THIS MORNING AND COULD INITIALLY BRING
A WINTRY MIX BUT STAYING CONFINED TO THE SOUTHERN HALF OF THE
CWA...PRIMARILY SOUTH OF THE I80 CORRIDOR. IF ANYTHING WERE TO OCCUR
DURING THIS TIME FRAME...ANTICIPATE IT TO BE ON THE LIGHTER SIDE
WITH THE PREVIOUSLY MENTIONED DRIER AIR STILL NEEDING TO BE
OVERCOME. NONETHELESS...WITH AN ANTICIPATED SLOWING TREND WITH THE
EVOLUTION OF TODAY`S SYSTEM...THIS WINTRY MIX COULD BE MORE PREVALENT
THAN PREVIOUSLY THOUGHT TO START THE PERIOD. SO HAVE INCLUDED CHANCE
ZR/IP IN THE GRIDS THROUGH 15Z.
CAN MAKE OUT TWO SEPARATE PIECES OF STRONG ENERGY TRAVERSING THE
MID LEVEL FLOW...NOW WITH ALL GUIDANCE IN STRONG AGREEMENT WITH THE
EVOLUTION OF THIS ENERGY AS IT APPROACHES THE REGION. ABOUT THE ONLY
DIFFERENCE AT THIS TIME IS SOME SLIGHT TIMING DIFFERENCES WITH THE
APPROACH OF THE BETTER FORCING/PRECIP LATER TODAY. A CONTINUED
SLOWER TREND HAS BEEN THE PREFERRED TREND HERE THIS MORNING...AND
HAVE DELAYED HIGHEST POPS TODAY. ALTHOUGH DID NOT OVERLY STRAY TOO
MUCH WITH THE PREVIOUSLY MENTIONED ISENTROPIC ASCENT AND POTENTIAL
PRECIP OUT AHEAD OF IT. HAVE CONTINUED THE MENTION IN THE GRIDS FOR
A MIX OF SLEET FOR LATER IN THE MORNING...MAINLY FOR THE SOUTHERN
TIER OF COUNTIES. ALTHOUGH THERMAL PROFILES WOULD BE SUPPORTIVE OF
THIS WINTRY MIX CONTINUING...HAVE LIMITED MENTION OF THIS MIX AS
BETTER FORCING SHOULD BE ARRIVING DURING THIS TIME. WHATEVER
LINGERING WARM WEDGE IN THE COLUMN WILL QUICKLY COOL THE COLUMN TO
THE WET BULB AS STRONG DYNAMIC FORCING ARRIVES...WITH ANY MIX
QUICKLY CHANGING OVER TO ALL SNOW.
ONCE AGAIN...ALL GUIDANCE POINTING AT SIGNIFICANT SNOWFALL RATES
BEGINNING AT SOON AS LATE MORNING FOR THE WESTERN CWA. TWO PIECES OF
ENERGY WILL PHASE TOGETHER BY EARLY AFTERNOON...WITH THIS MID/UPPER
LEVEL TROUGH BECOMING NEGATIVELY TILTED. AS THIS OCCURS...ATTENDANT
LOW TO DEEPEN AS IT MOVES THROUGH CENTRAL ILLINOIS WITH 850MB LOW
REALLY BEGINNING TO TAKE SHAPE. STRONG DYNAMICAL FORCING ASSOCIATED
WITH THIS MID LEVEL TROUGH AND SIGNIFICANT HEIGHT FALLS WILL ALLOW
FORCING TO SWING THROUGH THE CWA BY LATE MORNING INTO THE EARLY
AFTERNOON. ASSOCIATED FRONTOGENETICAL FORCING WILL LIKEWISE PUSH
EAST THROUGH THE AREA THIS AFTERNOON...WITH THE PRESENCE OF NEGATIVE
EPV. THIS PRESENCE OF BOTH SLANTWISE AND UPRIGHT MOTIONS ARE LEADING
FOR SOME REALLY IMPRESSIVE VERTICAL MOTION...WITH FORECAST OMEGA
AMONG ALL GUIDANCE SOME OF THE HIGHEST IVE OBSERVED IN SOME TIME.
THE STRONGEST VERTICAL MOTIONS ARE EXPECTED TO PUSH EAST TO WEST
ACROSS THE CWA INTO THE EARLY AFTERNOON TIME FRAME AND CONTINUING
THROUGH MID/LATE AFTERNOON...WITH FORCING CENTERED RIGHT IN THE
MIDDLE OF THE CWA. ALTHOUGH CURRENT FORECAST SNOW TOTALS ARE THE
HIGHEST IN THESE LOCATIONS...TOTALS DONT STRAY TOO MUCH FROM THE
AMOUNTS ACROSS THE REMAINING CWA. THIS IS IN DUE TO PART TO HOW
UNSTABLE THIS SYSTEM WILL BE...INCLUDING CONVECTIVE INSTABILITY.
BOTH NAM/GFS SHOWING IMPRESSIVE MUCAPE TO PUSH NORTHEAST THROUGH THE
CWA AS EARLY AS MID MORNING...AND THE BEGINNING STAGES OF THIS CAN
ALREADY BE OBSERVED TO OUR WEST/SOUTHWEST WITH LATEST RAP ANALYSIS
DEPICTING 100-200 J/KG OVER IOWA/MISSOURI/KANSAS. WITH SREF GUIDANCE
INDICATING HIGH PROBABILITIES OF AT LEAST 50-100 J/KG OF MUCAPE TO
MOVE OVERHEAD LATER TODAY...FEEL THAT THE NAM/GFS SOLUTION OF 100 TO
ALMOST 300 J/KG IS NOT OF THE QUESTION. THE PRESENCE OF THIS STRONG
FORCING...STRONG INSTABILITY AND ABUNDANCE OF MOISTURE NOT ONLY
LIKELY BEING PRESENT BUT ALSO COMING TOGETHER...HAS STEERED THE
FORECAST SIGNIFICANTLY MORE PESSIMISTIC THIS MORNING.
HEAVIEST SNOW...WHICH WILL FALL WITH HIGH INTENSITIES AND POSSIBLY
AT A RATE OF TWO TO THREE INCHES PER HOUR AT TIMES SHOULD ARRIVE THE
FAR WESTERN CWA BY MID/LATE MORNING...AND THEN SPREADING EAST
THROUGH THE REMAINING CWA BY EARLY AFTERNOON. EXPECT THESE HIGH
SNOWFALL INTENSITIES THROUGH MID TO LATE AFTERNOON...AND POSSIBLY
CONTINUE INTO THE EARLY EVENING FOR THE EASTERN THIRD OF THE CWA.
THIS HEAVY SNOW WILL QUICKLY ACCUMULATE ON ROADS WITH NEAR
VISIBILITY LIKELY UNDER THIS HEAVY SNOW...CREATING VERY HAZARDOUS
CONDITIONS. AS WAS MENTIONED PREVIOUSLY...THE HIGHEST TOTALS ARE IN
THE CWA ALIGNED WITH THE BETTER FORCING...BUT FEEL THAT ANY LACKING
FORCING WILL BE SUPPLEMENTED WITH THE CONVECTIVE NATURE OF THIS
SYSTEM. CONVECTIVE ALLOWING MODELS INDICATE THE PRESENCE OF THUNDER
BREAKING OUT BY EARLY AFTERNOON. ALTHOUGH GUIDANCE IS HINTING THAT
THIS WILL BE MORE PREFERRED ACROSS THE SOUTHERN CWA...WITH GUIDANCE
INDICATING INSTABILITY INTO SOUTHERN WISCONSIN...HAVE INCLUDED A
CHANCE FOR THUNDER IN THE GRIDS FOR THE ENTIRE CWA. ITS THESE
CONVECTIVE ELEMENTS WHICH COULD SUPPLEMENT HIGHER RATES AND
RESULTANT SNOWFALL TOTALS. SO FOR THE WARNING ISSUED
OVERNIGHT...WILL HAVE AREA WIDE 4 TO 8 INCHES WITH THE POSSIBILITY OF
SLIGHTLY HIGHER AMOUNTS NEAR 10 INCHES. IF THESE CONVECTIVE ELEMENTS
WERE TO MATERIALIZE...THEN AREAS DEFINITELY COULD OBSERVE THESE
HIGHER AMOUNTS. ALSO...ITS POSSIBLE THAT THESE AMOUNTS COULD BE
OBSERVED IN A 4-6 HOUR WINDOW. HAVE THE WARNING ENDING EARLY THIS
EVENING FOR THE WESTERN CWA AND THEN AT 3Z LATER THIS EVENING FOR
THE EASTERN CWA. IF LATER GUIDANCE THIS MORNING CONTINUES TO SUPPORT
CURRENT THINKING...SITUATION FORECAST TO UNFOLD LATER THIS AFTERNOON
WILL DEFINITELY BE SOMETHING TO NOT TAKE LIGHTLY.
RODRIGUEZ
LONG TERM (TUESDAY THROUGH SUNDAY)...
FAST ON THE HEELS OF TODAY`S DEPARTING SYSTEM WILL BE ANOTHER
NORTHERN STREAM SYSTEM TRACKING ACROSS SOUTHERN CANADA. VERY STRONG
WARM AIR ADVECTION WILL BE UNDERWAY ALOFT TUES MORNING AND
EVENTUALLY DEVELOPING AT THE SURFACE AS SOUTHERLY WINDS PICK UP.
DEEP AND FRESHLY RELOADED SNOW COVER OVER THE AREA WILL UNDOUBTEDLY
RETARD THE WARM UP...BUT STILL THINK TEMPS SHOULD MANAGE TO CLIMB
ABOVE FREEZING MOST AREAS FOR THE FIRST TIME IN WEEKS TUES
AFTERNOON.
WEAK COLD FRONT MOVES THROUGH TUESDAY EVENING WITH LITTLE FANFARE
AND BARELY TIME FOR MUCH COLD AIR TO SEEP SOUTHWARD BEFORE WARM AIR
ADVECTION BEGINS AGAIN LATER WEDNESDAY IN ADVANCE OF LATE WEDNESDAY
NIGHT INTO THURSDAY`S WELL ADVERTISED BIG HULLABALOO. NOT
SURPRISINGLY GIVEN THE COMPLEXITY OF THE PATTERN AND DEALING WITH
PHASING ISSUES...MODELS HAVE FLOPPED BACK FROM THEIR PREVIOUS FLIP
WITH MORE EMPHASIS ON A STRENGTHENING SOUTHERN LOW LIFTING NORTHEAST
INTO THE GREAT LAKES. STILL SOME DIFFERENCES IN STRENGTH AND EXACT
TRACK...BUT ECMWF/GFS NOW AGREE ON TAKING A SFC LOW OVER NORTHERN
MISSOURI 18Z THURS NORTHEAST TO THE UPPER GREAT LAKES BY THURSDAY
NIGHT...WITH CONSIDERABLE DEEPEN OF THE LOW ALONG THE WAY. ECMWF AND
06Z NAM ARE STRONGER AND A BIT FARTHER NORTHWEST...BUT NAM/GFS/ECMWF
ALL HAVE THE SAME GENERAL IDEA.
FIRST FORECAST ISSUE WILL BE WEDNESDAY NIGHT AS INITIAL BATCH OF WAA
PRECIP BREAKS OUT AND LIFTS NORTH ACROSS THE AREA. MODEL QPF REMAINS
FAIRLY HIGH AND WITH SOME ELEVATED INSTABILITY ALSO EVIDENT IN THE
MODELS...CERTAINLY ENOUGH TO WARRANT A CONTINUED SLIGHT CHANCE
MENTION OF THUNDERSTORMS. THE BIGGEST PROBLEM WED NIGHT WILL BE HOW
FAST THE 2M TEMPS WARM UP. WHILE VERY STRONG WAA WILL BE TAKING
PLACE ALOFT...INITIALLY EASTERLY WINDS OVER THE AREA AND DEEP SNOW
PACK COULD ALLOW FOR A RATHER PROLONGED PERIOD OF FREEZING RAIN AND
AN ICING THREAT DEPENDING ON SFC TEMPS. MANY OF THE MODEL SUGGEST A
SURGE OF WARM LATE WEDNESDAY NIGHT...ESPECIALLY SOUTHERN CWA...BUT
ITS GOING TO BE CLOSE. ONLY A MATTER OF A COUPLE DEGREES COULD MEAN
THE DIFFERENCE BETWEEN A SIGNIFICANT ICING PROBLEM AND ALL RAIN AND
THIS FAR OUT IT REALLY IS ANYONE`S GUESS WHAT SIDE OF 32F ANY ONE
GIVEN AREA WILL END UP ON AS THE RAIN FALLS. CERTAINLY FARTHER NORTH
WOULD STAND THE BETTER CHANCE OF FREEZING RAIN...BUT THE ICING
POTENTIAL CANNOT BE RULED OUT EVEN OVER SOUTHERN PORTIONS OF THE CWA.
THIS LATEST SWING IN THE MODELS TOWARD A MORE AMPLIFIED SOUTHERN LOW
TRACKING NORTH IS BAD NEWS FOR IN THE HYDROLOGY DEPARTMENT. WHILE
NOT AS HORRIFYING AS THE NIGHTMARE SCENARIO THE ECMWF HAD BEEN
PAINTING A COUPLE DAYS AGO WITH 50 AND NEAR 60F DEWPOINTS TO THE
WISCONSIN LINE...THE LATEST GUIDANCE DOES DRAG THE 40F ISODROSOTHERM
FAR NORTH INTO THE AREA ON THURSDAY...WITH EVEN SOME 50F DEWPOINTS
FAR SOUTHERN CWA. THE HIGHER THE DEWPOINTS THE MORE RAPID THE SNOW
MELT WILL BE AND THE MORE OF A PROBLEM ANY MODERATE TO HEAVY RAIN
THAT FALLS WILL POSE THURSDAY. TEMPS LOOK TO CLIMB SAFELY ABOVE
FREEZING THURS AM EVEN NORTH TO THE WI BORDER ENDING THE FRZ RAIN
THREAT...BUT WITH PWATS PROGGED TO CLIMB TO OVER AN INCH (200-250%
OF NORMAL) THURSDAY THE POTENTIAL WILL EXIST FOR HEAVY RAINFALL.
HAVE ALREADY BEEN HARPING ON ALL THE HYDRO CONCERNS IN THE ESF
ISSUED FRIDAY AND UPDATED OVER THE WEEKEND AND REALLY NO BIG CHANGES
IN THINKING AT THIS POINT OTHER THAN TO SAY THE FLOOD POTENTIAL IS
LOOKING MORE OMINOUS THAN IT DID 24 HOURS AGO.
STRONG COLD FRONT LOOKS TO SWEEP THROUGH THURSDAY EVENING BRINGING
AN END TO THE RAIN AND POSSIBLE THUNDERSTORMS AND ALLOWING DRIER AND
COLDER AIR TO FILTER INTO THE REGION. WHILE COLDER AIR FILTERS IN
FOR THE WEEKEND WITH MEDIUM RANGE MODELS SUGGESTING ONE OR TWO
SYSTEM COULD AFFECT THE REGION WITH WHAT WOULD PROBABLY BE SOME
SNOWFALL. TIMING AND TRACK OF THESE LOWER AMPLITUDE WAVES ARE ALL
OVER THE PLACE IN THE MODELS SO ONLY CARRYING LOW CHANCES POPS FOR
NOW.
IZZI
&&
.HYDROLOGY...
330 AM CST
LATEST MODEL GUIDANCE DOES LOOK MORE WORRISOME THAN IT DID 24
HOURS AGO REGARDING THE FLOOD POTENTIAL THURSDAY...POSSIBLY
LINGERING INTO THE WEEKEND. MORE DETAIL METEOROLOGICAL DISCUSSION
IS ABOVE. NO CHANGES REALLY TO THE PREVIOUS HYDROLOGICAL
DISCUSSION OTHER THAN SLIGHTLY MORE SNOW AND SNOW WATER
EQUIVALENT IS EXPECTED TO BE IN PLACE AFTER TODAY`S SNOW SYSTEM.
WILL FRESHEN UP THE ESF AGAIN THIS MORNING BUT NOT PLANNING ANY
BIG CHANGES.
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SLIGHT CHANCE FOR SNOW SHOWERS DURING THE MORNING
* HEAVY SNOW TO DEVELOP EARLY AFTERNOON WITH OCNL VSBY BETWEEN
1/16SM AND 1/4SM EXPECTED
* SLIGHT CHANCE OF THUNDERSTORM (THUNDERSNOW) IN THE AFTERNOON
* STRONG SOUTHEAST WINDS DEVELOP DURING MORNING WITH GUSTS TO
AROUND 25KT EXPECTED...DIMINISHING AS HEAVY SNOW STARTS
* QUICK IMPROVEMENT AS SNOW ENDS EARLY MONDAY EVENING
IZZI
//DISCUSSION...UPDATED 06Z...
LAKE EFFECT MVFR CIGS LIKELY TO PERSIST FOR AT LEAST A FEW MORE
HOURS OVERNIGHT BEFORE PROBABLY BREAKING UP LATE. CONTINUE TO SEE
SOME MODELS STARTING UP SNOW SHOWERS DURING THE MORNING HOURS
MONDAY...WHICH IF IT WERE TO HAPPEN COULD RESULT IN A MUCH EARLIER
ONSET TO IFR CONDITIONS THAN INDICATED IN THE CURRENT TAFS.
HANDLING THIS WITH A VCSH IN THE TAFS AND WILL MONITOR
RADAR/SATELLITE TRENDS THIS MORNING AND RE-ACCESS LATER. STRONG
PRESSURE FALLS TO OUR WEST IN RESPONSE TO THE DEVELOPING LOW WILL
RESULT IN A QUICK RAMP UP OF SOUTHEAST WINDS EARLY MONDAY MORNING
WITH GUSTS OF 25-30KT EXPECTED BY MID-LATE MORNING.
BIG STORY WILL BE THE INTENSE SNOW EXPECTED TO DEVELOP MONDAY
AFTERNOON. ALL INDICATIONS ARE THAT 3 TO 6 HOUR LONG WINDOW OF
MODERATE TO HEAVY SNOW WILL OCCUR MONDAY AFTERNOON. GETTING FAIRLY
STRONG SIGNALS IN THE MODELS TO SUPPORT PERIODIC VERY HEAVY
SNOWFALL WITH EVEN A SMALL CHANCE OF ISOLATED THUNDERSTORMS.
WINDS WILL SUBSIDE AS SNOW BEGINS BUT WITH SNOWFALL RATES OF AT
LEAST AN INCH PER HOUR LIKELY AND CRIPPLING RATES OF 2"+ PER HOUR
POSSIBLE THE DECREASING WINDS WILL BE A BIT OF A MOOT POINT.
CONDITIONS ARE LIKELY TO QUICKLY IMPROVE AS THE TROUGH MOVES
THROUGH EARLY MONDAY EVENING. WINDS WILL SHIFT TO WESTERLY AND
THERE WILL PROBABLY BE SEVERAL HOURS OF LINGER MVFR CIGS INTO THE
EVENING HOURS.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW CONFIDENCE IN SNOW POTENTIAL BETWEEN 13-18Z MONDAY
* HIGH CONFIDENCE IN ONSET TIME OF MOD-HVY SNOW +/- AN HOUR OR
TWO
* MEDIUM CONFIDENCE IN OCNL VSBY 1/4SM OR LOWER WITH ACCUMULATION
RATES OF 1"/HOUR OR GREATER
* MEDIUM-HIGH CONFIDENCE ON END TIME OF SNOW MONDAY EVENING +/- AN
HOUR OR TWO
* HIGH CONFIDENCE IN REMAINDER OF FORECAST ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY AND WEDNESDAY...PREDOMINANTLY VFR.
THURSDAY...RAIN/FOG/IFR LIKELY. FZRA POSSIBLE IN THE MORNING.
FRIDAY...VFR PROBABLE.
SATURDAY...CHANCE OF RA OR SN.
MDB
&&
.MARINE...
324 AM CST
HAVE HOISTED A GALE WARNING FOR A LARGE PORTION OF CENTRAL LAKE
MICHIGAN FOR TODAY. THE DEEPER SFC LOW IN THE MODELS SHOULD RESULT
IN A PERIOD OF SOUTHEAST GALES THIS MORNING INTO THE EARLY AFTERNOON
BEFORE THE BAGGIER PRESSURE GRADIENT APPROACHES THE LAKE ASSOCIATED
WITH THE INVERTED TROUGH NORTH OF THE LOW TRACKING ACROSS DOWNSTATE
IL AND IN. BRIEF SHOT OF WESTERLY WINDS TONIGHT IN THE WAKE OF THE
TROUGH AND DEPARTING LOW BEFORE SOUTHERLY WINDS BEGIN TO REALLY
CRANK UP AGAIN ON TUESDAY AS ANOTHER STRONG LOW TRACK EAST ACROSS
THE SOUTHERN CANADIAN PRAIRIES. COULD BE BORDERLINE SOUTHERLY GALES
ON TUESDAY AFTERNOON AS WELL...BUT FOR NOW JUST STUCK WITH OCNL GALE
WORDING IN THE GLF AND WILL LET NEXT SHIFT GET ANOTHER LOOK BEFORE
DECIDING ON POSSIBLE GALE HEADLINES FOR TUESDAY.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ020-ILZ021-ILZ032-ILZ039 UNTIL 6 PM MONDAY.
WINTER STORM WARNING...ILZ006-ILZ013-ILZ014-ILZ022-ILZ023-
ILZ033...9 AM MONDAY TO 9 PM MONDAY.
IN...WINTER STORM WARNING...INZ001-INZ002-INZ010-INZ011-INZ019...9 AM
MONDAY TO 9 PM MONDAY.
LM...GALE WARNING...LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ868-LMZ870-LMZ872-LMZ874-LMZ876...8 AM MONDAY TO 3 PM
MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
352 PM EST MON FEB 17 2014
.SYNOPSIS...
ISSUED AT 115 PM EST MON FEB 17 2014
A LOW PRESSURE SYSTEM OVER CENTRAL ILLINOIS WILL QUICKLY MOVE INTO
WESTERN LAKE ERIE THIS EVENING AND DEEPLY STRENGTHEN. THIS WILL
CAUSE A BAND OF MODERATE TO HEAVY SNOW TO PIVOT THROUGH THE AREA
THROUGH THE EVENING HOURS. SOME SLEET AND FREEZING RAIN WILL MIX
WITH THE SNOW ALONG AND SOUTH OF HIGHWAY 24 IN INDIANA AND OHIO.
TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN 2 AND 6
INCHES ACROSS THE FORECAST AREA...HEAVIEST ACROSS NORTHERN AREAS.
TRAVEL CONDITIONS WILL RAPIDLY DETERIORATE THROUGH THE AFTERNOON
AND EVENING HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 349 PM EST MON FEB 17 2014
SNOWFALL RATES 2-3.5 INCHES/HR IN XTRMLY HVY TSSN ENTERING WRN CWA.
CONTD VERY SIMILAR RAP/NAM/PREV BLENDED APPROACH UTILIZED WITH
MIDDAY UPDATE. GENERAL CONTD CONSENSUS OF SREF MEAN AND TIGHT PLUME
PACK IN ADDITION TO 12 UTC NAM COBB OUTPUT SUPPORTS LATEST EVENT
TOTALS IN PRIOR 1233 PM EST WSW UPDATE WITH HIEST GENRLY ALONG NORTH
OF TOLL ROAD. THANKFULLY XTRM RATES BRIEF AND WITH TRANSITION TO
LESS THAN OPTIMAL FLAKE SIZE OUTSIDE OF CONVECTIVE ELEMENTS SHOULD
KEEP MAJORITY OF ACCUMS TO LTE 6 INCHES. SOME CONCERN THOUGH FOR HIR
AMOUNTS WITH TROWAL LIFTING ACRS FAR NRN CWA THIS EVENING PRIOR TO
LIFTG FARTHER N OF CWA BYND 03 UTC...INDICATIONS THOUGH THAT IT WILL
LIE OUT E-W JUST NORTH OF CWA...BEFORE GRDL EWD LIFTOUT. LEADING
WARM CONVEYOR BELT INTENSE WITH XTRM MSTR TAP WITH 6-7 G/KG ON I295K
SFC SLIDES EWD THROUGH SRN IN THIS EVENING...PROVIDING XTRM
MFLUX/UVM ATOP NOSE OF RAMPING SWRLY 850-7H JET AXIS. JETLET OF 65
KTS AT 21 UTC POSITIONED ACRS SRN IN...STRENGTHENS TO 75 KTS MEAN
LYR FLOW INTO SRN OH BY 00 UTC. SPECIAL KILX MIDDAY SNDG YIELDS 320
J/KG MUCAPE/LIFTED FM 7H AND WHILE LATEST RAP TREND NOTED DOWNWARD
WRT MUCAPE WL CONT WITH PRIOR AREA ADDED AND HAVE NOW INCLUDED FAR
ERN AREAS AS WELL IN 22-02 UTC TIMEFRAME GIVEN APPROACH OF STOUT 6-7
C/KM MID TROPOSPHERIC LAPSE RATE PLUME AND SYSTEM DEEPENING. MID LVL
CIRC AND TO CLOSE OFF ACRS CHICAGOLAND SHORTLY AND TRACK EWD TO
WINDSOR ONT BY 09 UTC TUE...ALSO SUGGESTING HIEST AMOUNTS HERE/JUST
NORTH OF CWA...WHERE HIGHLY ELEVATED MAX UVM BEST COLLOCATED WITHIN
A SATURATED DGZ. RAPID CRASH OF CLOUD DEPTH IN WAKE OF SYSTEM IN
PERTURBED MOIST BLYR STILL SUGGESTIVE OF BRIEF LIGHT FZDZSN POTNL AT
BEFORE ENDING. HELD ONTO CLOUD COVER A BIT LONGER INTO TUE AWAITING
SHORTWAVE 925MB RIDGING THAT STILL HOLDS JUST WEST FM KGRB INTO NERN
IL AT 12 UTC TUE.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 349 PM EST MON FEB 17 2014
FOCUS CONTINUES ON WARMER TEMPERATURES/ADDITIONAL PRECIPITATION
THROUGH FRIDAY AND FLOODING/SEVERE WEATHER CONCERNS.
THE NEXT RIPPLE IN THE UPPER FLOW WILL AID IN THE DEVELOPMENT OF LOW
PRESSURE WHICH WILL TRACK ACROSS SOUTHERN CANADA WITH A TRAILING
COLD FRONT. THIS FRONT WILL SWEEP INTO THE REGION LATE TUES NGT INTO
WEDNESDAY BUT WILL BE STARVED OF MOISTURE AND DYNAMICS LEADING TO A
GENERALLY QUIET PASSAGE. ALTHOUGH COOLER AIR WILL ARRIVE BEHIND THE
FRONT...THIS WILL BE SHORT LIVED AND COMPARED TO THE AIR OF THE PAST
SEVERAL WEEKS WILL FEEL DOWNRIGHT NICE.
TEMPERATURES WILL CLIMB ABOVE FREEZING WEDNESDAY ALLOWING FOR THE
START OF THE MELTDOWN OF THE LARGE SNOWPACK ACROSS THE REGION.
DEWPOINTS WILL REMAIN IN THE 20S...KEEPING ANY FOG FORMATION AWAY
AND ALLOWING FOR A SLOW RELEASE AND NO SIGNIFICANT HYDRO ISSUES.
PIECE OF ENERGY ORIGINATING FROM GULF OF ALASKA UPPER LOW WILL DROP
INTO THE WESTERN STATES AND CARVE OUT A DEEPENING TROUGH WHICH WILL
ALLOW A SURGE OF EVEN WARMER AIR STARTING LATE WEDS NGT INTO THURS
GULF OF MEXICO OPENING WIDE TO SEND ABUNDANT MSTR TO THE REGION.
THIS WILL SET THE STAGE FOR PRECIP ARRIVING LATE WEDS NGT INTO
THURSDAY MORNING. LOW LEVEL THERMAL PROFILES SHOW ABOVE FREEZING
VALUES...HOWEVER REMAINING SNOWPACK MAY POSE A INITIAL CHALLENGE AND
THREAT OF BRIEF PERIOD OF FREEZING RAIN AT ONSET OF RAINFALL.
HOWEVER...BY MID THURSDAY MORNING TEMPS SHOULD BE ABOVE FREEZING AND
ANY ICING THREAT OVER. HAVE ADJUSTED GRIDS TO REFLECT THIS. IN
ADDITION...LAST FEW FRAMES OF NAM12 AND HINTS ON ECMWF/GFS INDICATE
NEGATIVE SHOWWALTER VALUES BEGIN TO NUDGE IN BY LATE MORNING IN
WESTERN AREAS AND ACROSS THE ENTIRE AREA THURS AFTERNOON. ECMWF IS
MOST AGGRESSIVE WITH MSTR RETURN AS SFC DEWPTS CLIMB INTO THE LOWER
50S IN SE HALF. WHILE SOME MODELS HINT THERE COULD BE A BREAK IN
PRECIP...HAVE DECIDED TO CONTINUE WITH CAT POPS...INTRODUCED THUNDER
WEST LATE AM AND INCREASED TO CHC THUNDER ALL AREAS THURS AFTN.
CONTINUED MENTION OF FOG WHICH WILL LIKELY BE DENSE AS DWPTS CLIMB
ABOVE 40S ACROSS THE ENTIRE AREA. BEST CHANCES FOR HEAVY RAINFALL
LOOK TO BE THROUGH THURS MORNING AND AGAIN LATE AFTN INTO EVENING AS
COLD FRONT ARRIVES. IN TERMS OF FLOODING THREAT...GREATEST RELEASE
WILL OCCUR INTO THURS EVE AND ONLY SLOW DOWN SOMEWHAT THURS NGT WITH
TEMPS CLIMBING BACK ABOVE FREEZING FRIDAY. IF ADVERTISED
DEWPOINTS DO ARRIVE...LIKELY WON`T BE MUCH OF A SNOWPACK LEFT WITH
FLOODING CONCERNS INCREASE SUBSTANTIALLY AND TEMPS IN THE 30S TO LOW
40S WILL ALLOW FOR CONTINUED MELTING. HWO AND ESF HAVE THIS HANDLED
WELL THUS FAR SO NO CHANGES PLANNED. TO COMPLICATE MATTERS
FURTHER...GIVEN THE AMOUNT OF MSTR...ELEVATED INSTABILITY AND STRONG
LL FLOW ON THE ORDER OF 60 KTS PLUS...THREAT FOR STG-SVR STORMS DOES
EXIST AND WILL NEED TO BE MONITORED. SPC PLACED IN/OH UNDER DAY 4
OUTLOOK FOR SEVERE ON MORNING ISSUANCE. WILL HOLD OFF FOR NOW ON
MENTION IN HWO.
SEVERAL CLIPPER SYSTEMS TO MOVE THROUGH OVER THE WEEKEND TO WRECK
HAVOC WITH TEMPS AS AFTERNOON HIGHS EVEN INTO SAT REMAIN NEAR OR
ABOVE FREEZING. MORE SIGNIFICANT BLAST OF COLD AIR WILL ARRIVE LATE
IN THE WEEKEND INTO NEXT WEEK AS 850 MB TEMPS DROP BACK TO -10 C OR
LOWER. CHANCE FOR PRECIP MAY ARRIVE WITH EACH CLIPPER SYSTEM BUT
KEEPING WITH GOING FORECAST WITH MINIMAL CHANCES FOR NOW AS
TIMING/TRACK ISSUES ABOUND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1250 PM EST MON FEB 17 2014
FOCUS PRIMARILY UPON UPSTREAM/RAPIDLY DEEPENING SYSTEM ACRS CNTL
IL TO TRACK INTO WRN LK ERIE BY LATE THIS EVENING. ELEVATED
CONVECTIVE POTNL NECESSITATES INCLUSION OF TSSN AT KSBN...CHCS TS
PSBL AT KFWA...BUT WILL HOLD FOR NOW. STILL SNOWFALL RATES 1 TO 2
INCHES PER HOUR TO BRING PERIOD OF IFR/LIFR MET CONDS ACRS NRN IN.
PTYPE SHOULD REMAIN ALL SNOW AT KSBN...THOUGH FAR NRN REACH OF
WARM LYR ALOFT MAY CREATE SOME MIXED SNPL AT KFWA PRIOR TO
CHANGEOVER TO ALL SNOW WITH STRONG DYNAMIC COLUMN COOLING. CLOUD
TOPS RAPIDLY LWR/WARM AS SYSTEM DEPARTS LATE THIS EVENING GIVING
POTNL FOR SUPERCOOLED FZDZ MIX WITH LIGHT SN. KEPT AOB FUEL ATL
INTO AT LEAST 14 UTC TUE PER STRENGTH OF INVERSION...LONGER THAN
LATEST MODEL GUID/PRIOR FCSTS WOULD SUGGEST.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 3 AM EST TUESDAY FOR INZ006>009-
017-018-025>027-032>034.
WINTER WEATHER ADVISORY UNTIL 11 PM EST /10 PM CST/ THIS EVENING
FOR INZ003>005-012>016-020-022>024.
MI...WINTER WEATHER ADVISORY UNTIL 3 AM EST TUESDAY FOR MIZ079>081.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR MIZ077-
078.
OH...WINTER WEATHER ADVISORY UNTIL 3 AM EST TUESDAY FOR OHZ001-002-
004-005-015-016-024-025.
LM...NONE.
&&
$$
SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MURPHY
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WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
116 PM EST MON FEB 17 2014
.SYNOPSIS...
ISSUED AT 115 PM EST MON FEB 17 2014
A LOW PRESSURE SYSTEM OVER CENTRAL ILLINOIS WILL QUICKLY MOVE INTO
WESTERN LAKE ERIE THIS EVENING AND DEEPLY STRENGTHEN. THIS WILL
CAUSE A BAND OF MODERATE TO HEAVY SNOW TO PIVOT THROUGH THE AREA
THROUGH THE EVENING HOURS. SOME SLEET AND FREEZING RAIN MAY MIX
WITH THE SNOW ALONG AND SOUTH OF HIGHWAY 24 IN INDIANA AND OHIO.
TOTAL SNOW ACCUMULATIONS ARE FORECAST TO RANGE BETWEEN 2 AND 6
INCHES ACROSS THE FORECAST AREA...HEAVIEST ACROSS NORTHERN AREAS.
TRAVEL CONDITIONS WILL RAPIDLY DETERIORATE THROUGH THE AFTERNOON
AND EVENING HOURS.
&&
.UPDATE...
ISSUED AT 1250 PM EST MON FEB 17 2014
DECISIVELY STRONG UPSTREAM MUCAPE PLUME 150-400 J/KG PER LATEST
RAP ANALYSIS ASSOCD WITH EXTREME LAPSE RATES AOA 700 MB. GIVEN
STRENGTH OF FORCED ASCENT OF 60 PLUS KNOT 8H JET AS IT MOVES EWD
ACRS SRN IN...THEN MORE NEWD INTO WCNTL OH THIS EVENING AS SYSTEM
UNDERGOES RAPID DEEPENING PER HFC BURGEONING TO 230-250M/12 HR AS
IT SLIDES EWD THRU CWA. INSTABILITY/DEEPENING AND POIGNANT DRY
SLOT PUNCH INTO SRN IL SUGGEST INTRODUCTION OF ISOLD TS IN HEAVY
SN APPLICAPLE FOR LATER THIS AFTN. PTYPE REMAINS A
CONCERN...THOUGH BY AND LARGE DYNAMIC/INITIAL EVAP COOLING SHOULD
PRECLUDE SIG NWD PENETRATION INTO SRN REACH OF CWA...SIMILAR TO
LATEST RAP13 MAX TW PROGS. BRIEF ZR PSBL HERE THOUGH
SLEETY/GRAUPEL MIX MORE DOMINANT...STILL KEEPING SLR IN CHECK.
FARTHER NORTH CONVECTIVE ELEMENTS TO SUPPORT BRIEF SNFL RATES NEAR
2 IN/HR. FURTHERMORE...CLOSE OFF OF MID TROPOSPHERIC FLOW ACRS
SRN MI AS IT GENUFLECTS TO NEG TILT WITH WWD BEND TO MOIST I295K
TROWAL LIFTING NWD ACRS TOLL ROAD INTO SRN LWR MI...TO LIKELY
BRING HIEST AMOUNTS ACRS NWRN IN INTO SCNTL LWR MI...WHERE ISOLD
GTE 6 INCHES PSBL.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM EST MON FEB 17 2014
BURST OF MOD-HVY SNOW LATER THIS AFTN AND EVE / MIXED WITH SLEET
SOUTH OF HWY 24 / THE PRIMARY FOCUS THIS PERIOD...
MORNING WATER VAPOR IMAGERY SHOWS A WELL DEFINED PV ANOMALY NEAR THE
NE/CO BORDER WITH ANOTHER NORTHERN STREAM UPPER WAVE EDGING TOWARD
THE MT/ND BORDER. GUIDANCE NOW IN EXCELLENT AGREEMENT IN PHASING
THESE WAVES AS THEY RIPPLE QUICKLY EAST WITH A CLOSED MID LVL
CIRCULATION EVENTUALLY EMERGING OVER SOUTHERN LOWER MICHIGAN THIS
EVENING. THIS STRONG UPPER TROUGH WILL SHIFT NEGATIVE AND DEEP WITH
1.5 PVU SFC NEAR 700 MB ONCE IT LIFTS INTO IL/IN LATER TODAY.
ASSOCIATED DEEP PLUME OF UPWARD VERTICAL MOTION WITH VIGOROUS
WAVE LOOKS TO LIFT ENE THROUGH THE LOCAL AREA LATER THIS AFTN/EVE
WITH A 4-7 HOUR PERIOD OF ACCUMULATING SNOW ANTICIPATED. SNOWFALL
RATES OF 1-2" PER HR POSSIBLE GIVEN VERY STRONG DYNAMICS AND LOW
LEVEL MOISTURE TRANSPORT/CONVERGENCE WITHIN DEVELOPING TROWAL AS
SFC REFLECTION DEEPENS NORTHEAST INTO NRN INDIANA/SE MI.
XSECTIONS/SOUNDINGS IMPRESSIVE WITH STEEP MID LVL LAPSE RATES INTO
ESPECIALLY SOUTHERN AREAS ALONG WITH A THIN LAYER WHERE THETA-E
DECREASES WITH HEIGHT. GIVEN THIS CANNOT RULE OUT SOME THUNDER BUT
COVERAGE AND CONFIDENCE OF OCCURRENCE REMAINS TOO LOW TO INCLUDE A
THUNDER MENTION IN GRIDS. NORTHERLY TRACK OF THIS PHASED SYSTEM
WILL ALLOW SOME WARMER AIR ALOFT TO WORK INTO AREAS SOUTH/ALONG
THE HWY 24 CORRIDOR WHERE PRECIP MAY MIX WITH SLEET (AND LOWER CHC
FOR FREEZING RAIN FAR SOUTH) TO START BEFORE DYNAMIC/EVAPORATIVE
COOLING OVERWHELMS SUPPORTING A CHANGEOVER TO ALL SNOW. THIS
SHOULD CUT DOWN ON SNOW TOTAL A BIT HERE...WITH HEAVIEST TOTALS
EXPECTED ACROSS THE FAR NORTH WHERE PIVOT IS EXPECTED UNDER
DEVELOPING 700 MB LOW TRACK. CURRENT EXPECTATIONS ARE FOR A QUICK
4-6" (LOCALIZED 6" PLUS AMOUNTS POSSIBLE) OF SNOW NORTHWEST OF HWY
24...3-5" ALONG HWY 24...AND 2-4" SOUTHEAST OF HWY 24. STRONG RISE
FALL COUPLET OVERSPREADS THIS EVENING INTO THE EARLY OVERNIGHT
HOURS WHICH MAY CREATE SOME BLOWING/DRIFTING SNOW FOR A TIME.
AS FOR THE NEAR TERM (THIS MORNING INTO EARLY AFTN)...6-8 MB SFC 3
HR PRESSURE FALLS WILL ALLOW WINDS TO PICK UP AND GUST TO BTW 25-30
MPH LATER THIS MORNING. THIS MAY LEAD TO SOME BLOWING AND DRIFTING
IN RURAL/OPEN AREAS. CHANCES FOR SNOW INCREASE WITH TIME AS 850-700
MB THETA-E GRADIENT SHIFTS EAST INTO WESTERN AREAS THIS MORNING.
BAND OF SNOW TRYING TO GET STARTED ALONG THIS GRADIENT ACROSS
SOUTHERN WI/NORTHERN IL AS OF THIS WRITING BUT LOSING THE BATTLE TO
DRY SUB-CLOUD LAYER AT THIS TIME. RAP SATURATES OVER THE AREA WITH
RELATIVE NARROW OF SNOW DEVELOPING OVER WESTERN ZONES BTW 15-18Z
WHILE THE 06Z NAM SLOWER AFTER 18Z. OPTED FOR CHC POPS GIVEN THE
UNCERTAINTY.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 343 AM EST MON FEB 17 2014
FOR TUESDAY...QUIET WEATHER IN STORE WITH DEPARTURE OF MONDAYS SNOW
PRODUCER...AS SHORT WAVE UPPER RIDGING TRACKS ACROSS THE GREAT
LAKES. MID/UPPER LEVEL PATTERN TO BE QUITE PROGRESSIVE THROUGH MID
WEEK AS LOWER AMPLITUDE WAVE TRACKS ACROSS NORTHERN PLAINS/NORTHERN
GREAT LAKES EVENTUALLY ALLOWING SFC TROUGH/COLD FRONT PASSAGE INTO
THE AREA TUESDAY NIGHT/EARLY WEDNESDAY MORNING. LOW LEVEL HEIGHT
GRADIENT SHOULD STEADILY STRENGTHEN ON TUESDAY IN ADVANCE OF THIS
TROUGH WHICH SHOULD ALLOW FOR SOUTH WINDS TO INCREASE BY MIDDAY.
CURRENTLY EXPECTING GUSTS UP TO AROUND 25 MPH WHICH COULD CREATE
SOME DRIFTING CONCERNS EARLY TUESDAY AFTERNOON ACROSS OPEN AREAS FOR
ESPECIALLY EAST TO WEST ORIENTED ROADWAYS. RELATIVELY LOWER SNOW TO
LIQUID RATIOS AND SFC TEMPS WARMING TO ABOVE FREEZING IN THE
AFTERNOON SHOULD TEND TO MITIGATE THIS CONCERN HOWEVER. THE
RELATIVELY DRY AIR MASS IN PLACE SHOULD LIMIT ANY MEASURABLE PRECIP
CHANCES IN ASSOCIATION WITH THE FRONT TUESDAY NIGHT...ALTHOUGH GIVEN
MOISTURE PROFILES AND WEAK LIFT CANNOT COMPLETELY RULE OUT SOME VERY
LIGHT PATCHY FREEZING DRIZZLE FOR A BRIEF TIME IN IMMEDIATE VICINITY
OF THE FRONT.
WEAK THERMAL TROUGH WILL BE IN PLACE ACROSS THE AREA FOR WEDNESDAY
BEHIND THIS FRONT...WITH EVENTUAL ONSET OF STRONGER LOW LEVEL WAA
AGAIN TOWARD WEDNESDAY EVENING AS LOW LEVEL ANTICYCLONE SHIFTS TO
THE MID ATLANTIC STATES. PRESENCE OF LOW LEVEL THERMAL TROUGH AND
VERY SHALLOW MIXED LAYER DEPTHS SHOULD RESULT IN HIGHS A DEGREE OR
TWO LOWER THAN TUESDAY AFTERNOON...ALTHOUGH STILL INTO AT LEAST MID
30S MOST LOCATIONS. WITH DAYTIME TEMPS MARGINALLY ABOVE FREEZING AND
NIGHTTIME TEMPS EXPECTED TO DROP BELOW FREEZING TUESDAY
NIGHT/WEDNESDAY NIGHT...SNOWMELT WILL BE VERY GRADUAL AND NO
SIGNIFICANT HYDROLOGIC IMPACTS ARE EXPECTED THROUGH MIDWEEK.
CONCERN FOR THURSDAY WILL THEN SHIFT TO WARMING TREND AND POTENTIAL
FOR SIGNIFICANT RAINFALL WHICH WILL LEAD TO INCREASED FLOOD
POTENTIAL. BULK OF GUIDANCE HAS NOW SHIFTED BACK TO TREND OF SEVERAL
DAYS AGO IN DEPICTING TWO DISTINCT EASTERN PACIFIC WAVES PHASING
ACROSS THE UPPER MIDWEST/NORTHERN GREAT LAKES...AND PROMOTING
STRONGER CYCLOGENESIS ACROSS THE WESTERN GREAT LAKES FOR THURSDAY.
DETAILS STILL DIFFICULT TO PIN DOWN AT THIS POINT WITH HOW THESE
WAVES WILL INTERACT AND EXTENT/TIMING OF LOW LEVEL DEEPENING...BUT
HAVE SLIGHTLY TRENDED FORECAST TO THIS STRONGER EVOLUTION. STRONG
LOW LEVEL THETAE ADVECTION/MOISTURE TRANSPORT TO RACE NORTHEASTWARD
INTO THE LOCAL AREA BY THURSDAY MORNING WITH PTYPE CONCERNS LIKELY
TO EXIST AT ONSET OF PRECIP. A BRIEF PERIOD OF -SN/-FZRA IS POSSIBLE
THURSDAY MORNING BEFORE STRENGTH OF LOW LEVEL ADVECTION OVERWHELMS
PROFILES AND SUPPORTS LIQUID PRECIP TYPE. AFTER THIS INITIAL
WARM/MOIST ADVECTIVE SURGE THURSDAY...ITEM OF LOWER CONFIDENCE WILL
BE POTENTIAL FOR ANY ADDITIONAL PRECIP INTO THURSDAY EVENING THAT
MAY HAVE SOME CONVECTIVE NATURE DEPENDING ON EXACT EVOLUTION OF
PATTERN. THIS WILL NEED TO BE WATCHED FOR POTENTIAL HIGHER RAINFALL
AMOUNTS THAT WILL IMPACT FLOOD POTENTIAL...ESPECIALLY IN LIGHT OF
SFC DEW POINTS LIKELY RISING INTO THE UPPER 30S TO LOWER 40S THAT
WILL ACCELERATE SNOWMELT. LARGER SCALE FRONTAL FORCING MAY ALLOW
RAIN TO PERSIST THROUGH MUCH OF THURSDAY NIGHT...ESPECIALLY ACROSS
EASTERN HALF OF THE AREA. COLDER AIR TO ADVECT BACK INTO THE REGION
FOR FRIDAY BEHIND THIS SYSTEM THAT MAY PROVIDE SOME BENEFIT TO
RUNOFF FROM RECENT RAIN/MELTING SNOW. WILL CONTINUE WITH ESF THIS
MORNING HIGHLIGHTING OVERALL POTENTIAL...BUT MUCH OF THIS WILL
DEPEND ON EXACT RAINFALL AMOUNTS THURSDAY ALONG WITH HOW QUICKLY
UPSTREAM SYSTEM PHASES WHICH WILL BE CRITICAL FOR TEMP/DEW PT
TRENDS.
PREDICTABILITY IN SMALLER SCALE WAVES IMPACTING THE AREA FOR THE
WEEKEND STILL QUITE LOW AT THIS TIME...ALTHOUGH NEW 00Z GUIDANCE
STILL SUPPORTS IDEA OF DEEPER MOISTURE SHUNTED WELL SOUTH OF THE
AREA. HAVE CONTINUED PREVIOUS LOW CHANCE -SN/RA POPS FOR THE WEEKEND
WITH A SERIES OF LOW LEVEL AMPLITUDE CLIPPER SYSTEMS POSSIBLE
THROUGH THE EARLY PORTIONS OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1250 PM EST MON FEB 17 2014
FOCUS PRIMARILY UPON UPSTREAM/RAPIDLY DEEPENING SYSTEM ACRS CNTL
IL TO TRACK INTO WRN LK ERIE BY LATE THIS EVENING. ELEVATED
CONVECTIVE POTNL NECESSITATES INCLUSION OF TSSN AT KSBN...CHCS TS
PSBL AT KFWA...BUT WILL HOLD FOR NOW. STILL SNOWFALL RATES 1 TO 2
INCHES PER HOUR TO BRING PERIOD OF IFR/LIFR MET CONDS ACRS NRN IN.
PTYPE SHOULD REMAIN ALL SNOW AT KSBN...THOUGH FAR NRN REACH OF
WARM LYR ALOFT MAY CREATE SOME MIXED SNPL AT KFWA PRIOR TO
CHANGEOVER TO ALL SNOW WITH STRONG DYNAMIC COLUMN COOLING. CLOUD
TOPS RAPIDLY LWR/WARM AS SYSTEM DEPARTS LATE THIS EVENING GIVING
POTNL FOR SUPERCOOLED FZDZ MIX WITH LIGHT SN. KEPT AOB FUEL ATL
INTO AT LEAST 14 UTC TUE PER STRENGTH OF INVERSION...LONGER THAN
LATEST MODEL GUID/PRIOR FCSTS WOULD SUGGEST.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 3 AM EST TUESDAY FOR INZ006>009-
017-018-025>027-032>034.
WINTER WEATHER ADVISORY UNTIL 11 PM EST /10 PM CST/ THIS EVENING
FOR INZ003>005-012>016-020-022>024.
MI...WINTER WEATHER ADVISORY UNTIL 3 AM EST TUESDAY FOR MIZ079>081.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR MIZ077-
078.
OH...WINTER WEATHER ADVISORY UNTIL 3 AM EST TUESDAY FOR OHZ001-002-
004-005-015-016-024-025.
LM...NONE.
&&
$$
UPDATE...MURPHY
SYNOPSIS...MURPHY
SHORT TERM...STEINWEDEL
LONG TERM...MARSILI
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
550 AM EST MON FEB 17 2014
.SYNOPSIS...
ISSUED AT 343 PM EST MON FEB 17 2014
A LOW PRESSURE SYSTEM OVER THE PLAINS WILL MOVE EAST THROUGH
INDIANA THIS AFTERNOON AND EVENING...CAUSING A BAND OF MODERATE
TO HEAVY SNOW TO PIVOT THROUGH THE AREA DURING THIS TIME. SOME
SLEET AND FREEZING RAIN MAY MIX WITH THE SNOW ALONG AND SOUTH OF
HIGHWAY 24 IN INDIANA AND OHIO. TOTAL SNOW ACCUMULATIONS ARE
FORECAST TO RANGE BETWEEN 2 AND 6 INCHES ACROSS THE FORECAST
AREA...HEAVIEST ACROSS NORTHERN AREAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM EST MON FEB 17 2014
BURST OF MOD-HVY SNOW LATER THIS AFTN AND EVE / MIXED WITH SLEET
SOUTH OF HWY 24 / THE PRIMARY FOCUS THIS PERIOD...
MORNING WATER VAPOR IMAGERY SHOWS A WELL DEFINED PV ANOMALY NEAR THE
NE/CO BORDER WITH ANOTHER NORTHERN STREAM UPPER WAVE EDGING TOWARD
THE MT/ND BORDER. GUIDANCE NOW IN EXCELLENT AGREEMENT IN PHASING
THESE WAVES AS THEY RIPPLE QUICKLY EAST WITH A CLOSED MID LVL
CIRCULATION EVENTUALLY EMERGING OVER SOUTHERN LOWER MICHIGAN THIS
EVENING. THIS STRONG UPPER TROUGH WILL SHIFT NEGATIVE AND DEEP WITH
1.5 PVU SFC NEAR 700 MB ONCE IT LIFTS INTO IL/IN LATER TODAY.
ASSOCIATED DEEP PLUME OF UPWARD VERTICAL MOTION WITH VIGOROUS
WAVE LOOKS TO LIFT ENE THROUGH THE LOCAL AREA LATER THIS AFTN/EVE
WITH A 4-7 HOUR PERIOD OF ACCUMULATING SNOW ANTICIPATED. SNOWFALL
RATES OF 1-2" PER HR POSSIBLE GIVEN VERY STRONG DYNAMICS AND LOW
LEVEL MOISTURE TRANSPORT/CONVERGENCE WITHIN DEVELOPING TROWAL AS
SFC REFLECTION DEEPENS NORTHEAST INTO NRN INDIANA/SE MI.
XSECTIONS/SOUNDINGS IMPRESSIVE WITH STEEP MID LVL LAPSE RATES INTO
ESPECIALLY SOUTHERN AREAS ALONG WITH A THIN LAYER WHERE THETA-E
DECREASES WITH HEIGHT. GIVEN THIS CANNOT RULE OUT SOME THUNDER BUT
COVERAGE AND CONFIDENCE OF OCCURRENCE REMAINS TOO LOW TO INCLUDE A
THUNDER MENTION IN GRIDS. NORTHERLY TRACK OF THIS PHASED SYSTEM
WILL ALLOW SOME WARMER AIR ALOFT TO WORK INTO AREAS SOUTH/ALONG
THE HWY 24 CORRIDOR WHERE PRECIP MAY MIX WITH SLEET (AND LOWER CHC
FOR FREEZING RAIN FAR SOUTH) TO START BEFORE DYNAMIC/EVAPORATIVE
COOLING OVERWHELMS SUPPORTING A CHANGEOVER TO ALL SNOW. THIS
SHOULD CUT DOWN ON SNOW TOTAL A BIT HERE...WITH HEAVIEST TOTALS
EXPECTED ACROSS THE FAR NORTH WHERE PIVOT IS EXPECTED UNDER
DEVELOPING 700 MB LOW TRACK. CURRENT EXPECTATIONS ARE FOR A QUICK
4-6" (LOCALIZED 6" PLUS AMOUNTS POSSIBLE) OF SNOW NORTHWEST OF HWY
24...3-5" ALONG HWY 24...AND 2-4" SOUTHEAST OF HWY 24. STRONG RISE
FALL COUPLET OVERSPREADS THIS EVENING INTO THE EARLY OVERNIGHT
HOURS WHICH MAY CREATE SOME BLOWING/DRIFTING SNOW FOR A TIME.
AS FOR THE NEAR TERM (THIS MORNING INTO EARLY AFTN)...6-8 MB SFC 3
HR PRESSURE FALLS WILL ALLOW WINDS TO PICK UP AND GUST TO BTW 25-30
MPH LATER THIS MORNING. THIS MAY LEAD TO SOME BLOWING AND DRIFTING
IN RURAL/OPEN AREAS. CHANCES FOR SNOW INCREASE WITH TIME AS 850-700
MB THETA-E GRADIENT SHIFTS EAST INTO WESTERN AREAS THIS MORNING.
BAND OF SNOW TRYING TO GET STARTED ALONG THIS GRADIENT ACROSS
SOUTHERN WI/NORTHERN IL AS OF THIS WRITING BUT LOSING THE BATTLE TO
DRY SUB-CLOUD LAYER AT THIS TIME. RAP SATURATES OVER THE AREA WITH
RELATIVE NARROW OF SNOW DEVELOPING OVER WESTERN ZONES BTW 15-18Z
WHILE THE 06Z NAM SLOWER AFTER 18Z. OPTED FOR CHC POPS GIVEN THE
UNCERTAINTY.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 343 AM EST MON FEB 17 2014
FOR TUESDAY...QUIET WEATHER IN STORE WITH DEPARTURE OF MONDAYS SNOW
PRODUCER...AS SHORT WAVE UPPER RIDGING TRACKS ACROSS THE GREAT
LAKES. MID/UPPER LEVEL PATTERN TO BE QUITE PROGRESSIVE THROUGH MID
WEEK AS LOWER AMPLITUDE WAVE TRACKS ACROSS NORTHERN PLAINS/NORTHERN
GREAT LAKES EVENTUALLY ALLOWING SFC TROUGH/COLD FRONT PASSAGE INTO
THE AREA TUESDAY NIGHT/EARLY WEDNESDAY MORNING. LOW LEVEL HEIGHT
GRADIENT SHOULD STEADILY STRENGTHEN ON TUESDAY IN ADVANCE OF THIS
TROUGH WHICH SHOULD ALLOW FOR SOUTH WINDS TO INCREASE BY MIDDAY.
CURRENTLY EXPECTING GUSTS UP TO AROUND 25 MPH WHICH COULD CREATE
SOME DRIFTING CONCERNS EARLY TUESDAY AFTERNOON ACROSS OPEN AREAS FOR
ESPECIALLY EAST TO WEST ORIENTED ROADWAYS. RELATIVELY LOWER SNOW TO
LIQUID RATIOS AND SFC TEMPS WARMING TO ABOVE FREEZING IN THE
AFTERNOON SHOULD TEND TO MITIGATE THIS CONCERN HOWEVER. THE
RELATIVELY DRY AIR MASS IN PLACE SHOULD LIMIT ANY MEASURABLE PRECIP
CHANCES IN ASSOCIATION WITH THE FRONT TUESDAY NIGHT...ALTHOUGH GIVEN
MOISTURE PROFILES AND WEAK LIFT CANNOT COMPLETELY RULE OUT SOME VERY
LIGHT PATCHY FREEZING DRIZZLE FOR A BRIEF TIME IN IMMEDIATE VICINITY
OF THE FRONT.
WEAK THERMAL TROUGH WILL BE IN PLACE ACROSS THE AREA FOR WEDNESDAY
BEHIND THIS FRONT...WITH EVENTUAL ONSET OF STRONGER LOW LEVEL WAA
AGAIN TOWARD WEDNESDAY EVENING AS LOW LEVEL ANTICYCLONE SHIFTS TO
THE MID ATLANTIC STATES. PRESENCE OF LOW LEVEL THERMAL TROUGH AND
VERY SHALLOW MIXED LAYER DEPTHS SHOULD RESULT IN HIGHS A DEGREE OR
TWO LOWER THAN TUESDAY AFTERNOON...ALTHOUGH STILL INTO AT LEAST MID
30S MOST LOCATIONS. WITH DAYTIME TEMPS MARGINALLY ABOVE FREEZING AND
NIGHTTIME TEMPS EXPECTED TO DROP BELOW FREEZING TUESDAY
NIGHT/WEDNESDAY NIGHT...SNOWMELT WILL BE VERY GRADUAL AND NO
SIGNIFICANT HYDROLOGIC IMPACTS ARE EXPECTED THROUGH MIDWEEK.
CONCERN FOR THURSDAY WILL THEN SHIFT TO WARMING TREND AND POTENTIAL
FOR SIGNIFICANT RAINFALL WHICH WILL LEAD TO INCREASED FLOOD
POTENTIAL. BULK OF GUIDANCE HAS NOW SHIFTED BACK TO TREND OF SEVERAL
DAYS AGO IN DEPICTING TWO DISTINCT EASTERN PACIFIC WAVES PHASING
ACROSS THE UPPER MIDWEST/NORTHERN GREAT LAKES...AND PROMOTING
STRONGER CYCLOGENESIS ACROSS THE WESTERN GREAT LAKES FOR THURSDAY.
DETAILS STILL DIFFICULT TO PIN DOWN AT THIS POINT WITH HOW THESE
WAVES WILL INTERACT AND EXTENT/TIMING OF LOW LEVEL DEEPENING...BUT
HAVE SLIGHTLY TRENDED FORECAST TO THIS STRONGER EVOLUTION. STRONG
LOW LEVEL THETAE ADVECTION/MOISTURE TRANSPORT TO RACE NORTHEASTWARD
INTO THE LOCAL AREA BY THURSDAY MORNING WITH PTYPE CONCERNS LIKELY
TO EXIST AT ONSET OF PRECIP. A BRIEF PERIOD OF -SN/-FZRA IS POSSIBLE
THURSDAY MORNING BEFORE STRENGTH OF LOW LEVEL ADVECTION OVERWHELMS
PROFILES AND SUPPORTS LIQUID PRECIP TYPE. AFTER THIS INITIAL
WARM/MOIST ADVECTIVE SURGE THURSDAY...ITEM OF LOWER CONFIDENCE WILL
BE POTENTIAL FOR ANY ADDITIONAL PRECIP INTO THURSDAY EVENING THAT
MAY HAVE SOME CONVECTIVE NATURE DEPENDING ON EXACT EVOLUTION OF
PATTERN. THIS WILL NEED TO BE WATCHED FOR POTENTIAL HIGHER RAINFALL
AMOUNTS THAT WILL IMPACT FLOOD POTENTIAL...ESPECIALLY IN LIGHT OF
SFC DEW POINTS LIKELY RISING INTO THE UPPER 30S TO LOWER 40S THAT
WILL ACCELERATE SNOWMELT. LARGER SCALE FRONTAL FORCING MAY ALLOW
RAIN TO PERSIST THROUGH MUCH OF THURSDAY NIGHT...ESPECIALLY ACROSS
EASTERN HALF OF THE AREA. COLDER AIR TO ADVECT BACK INTO THE REGION
FOR FRIDAY BEHIND THIS SYSTEM THAT MAY PROVIDE SOME BENEFIT TO
RUNOFF FROM RECENT RAIN/MELTING SNOW. WILL CONTINUE WITH ESF THIS
MORNING HIGHLIGHTING OVERALL POTENTIAL...BUT MUCH OF THIS WILL
DEPEND ON EXACT RAINFALL AMOUNTS THURSDAY ALONG WITH HOW QUICKLY
UPSTREAM SYSTEM PHASES WHICH WILL BE CRITICAL FOR TEMP/DEW PT
TRENDS.
PREDICTABILITY IN SMALLER SCALE WAVES IMPACTING THE AREA FOR THE
WEEKEND STILL QUITE LOW AT THIS TIME...ALTHOUGH NEW 00Z GUIDANCE
STILL SUPPORTS IDEA OF DEEPER MOISTURE SHUNTED WELL SOUTH OF THE
AREA. HAVE CONTINUED PREVIOUS LOW CHANCE -SN/RA POPS FOR THE WEEKEND
WITH A SERIES OF LOW LEVEL AMPLITUDE CLIPPER SYSTEMS POSSIBLE
THROUGH THE EARLY PORTIONS OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 550 AM EST MON FEB 17 2014
MAINLY VFR THIS MORNING WITH PRIMARY FOCUS ON RAPIDLY DETERIORATING
FLIGHT CONDITIONS WITH 4-6 HR PERIOD OF MODERATE/HEAVY SNOW LATE
THIS AFTN AND EVE AS A VERY DYNAMIC/STRONG UPPER LEVEL SYSTEM
LIFTS INTO THE AREA. OTHERWISE...IMPRESSIVE PRESSURE FALLS THROUGH
EARLY AFTERNOON WILL RESULT IN A BREEZY DAY WITH SHALLOW MIXING
GENERALLY HOLDING GUSTS TO LESS THAN 30 KNOTS BEFORE DIMINISHING
LATE AFTN/EARLY EVE AS SFC LOW CENTER TRACKS INTO NORTHERN
INDIANA. IMPROVING CONDITIONS ARE EXPECTED LATER TONIGHT AS SYSTEM
LIFTS OUT OF THE AREA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM EST
TUESDAY FOR INZ006>009-017-018-025>027-032>034.
WINTER WEATHER ADVISORY FROM NOON EST /11 AM CST/ TODAY TO 11 PM
EST /10 PM CST/ THIS EVENING FOR INZ003>005-012>016-020-
022>024.
MI...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM EST
TUESDAY FOR MIZ079>081.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 11 PM EST THIS
EVENING FOR MIZ077-078.
OH...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM EST
TUESDAY FOR OHZ001-002-004-005-015-016-024-025.
LM...NONE.
&&
$$
SYNOPSIS...JT
SHORT TERM...STEINWEDEL
LONG TERM...MARSILI
AVIATION...STEINWEDEL
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...CORRECTION
NWS NORTHERN INDIANA
345 AM EST MON FEB 17 2014
.SYNOPSIS...
ISSUED AT 343 PM EST MON FEB 17 2014
A LOW PRESSURE SYSTEM OVER THE PLAINS WILL MOVE EAST THROUGH
INDIANA THIS AFTERNOON AND EVENING...CAUSING A BAND OF MODERATE
TO HEAVY SNOW TO PIVOT THROUGH THE AREA DURING THIS TIME. SOME
SLEET AND FREEZING RAIN MAY MIX WITH THE SNOW ALONG AND SOUTH OF
HIGHWAY 24 IN INDIANA AND OHIO. TOTAL SNOW ACCUMULATIONS ARE
FORECAST TO RANGE BETWEEN 2 AND 6 INCHES ACROSS THE FORECAST
AREA...HEAVIEST ACROSS NORTHERN AREAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM EST MON FEB 17 2014
BURST OF MOD-HVY SNOW THIS AFTN/EVE / MIXED WITH SLEET SOUTH OF
HWY 24 / THE PRIMARY FOCUS THIS PERIOD...
MORNING WATER VAPOR IMAGERY SHOWS A WELL DEFINED PV ANOMALY NEAR THE
NE/CO BORDER WITH ANOTHER NORTHERN STREAM UPPER WAVE EDGING TOWARD
THE MT/ND BORDER. GUIDANCE NOW IN EXCELLENT AGREEMENT IN PHASING
THESE WAVES AS THEY RIPPLE QUICKLY EAST WITH A CLOSED MID LVL
CIRCULATION EVENTUALLY EMERGING OVER SOUTHERN LOWER MICHIGAN THIS
EVENING. THIS STRONG UPPER TROUGH WILL SHIFT NEGATIVE AND DEEP WITH
1.5 PVU SFC NEAR 700 MB ONCE IT LIFTS INTO IL/IN LATER TODAY.
ASSOCIATED DEEP PLUME OF UPWARD VERTICAL MOTION WITH VIGOROUS
WAVE LOOKS TO LIFT ENE THROUGH THE LOCAL AREA LATER THIS AFTN/EVE
WITH A 4-7 HOUR PERIOD OF ACCUMULATING SNOW ANTICIPATED. SNOWFALL
RATES OF 1-2" PER HR POSSIBLE GIVEN VERY STRONG DYNAMICS AND LOW
LEVEL MOISTURE TRANSPORT/CONVERGENCE WITHIN DEVELOPING TROWAL AS
SFC REFLECTION DEEPENS NORTHEAST INTO NRN INDIANA/SE MI.
XSECTIONS/SOUNDINGS IMPRESSIVE WITH STEEP MID LVL LAPSE RATES INTO
ESPECIALLY SOUTHERN AREAS ALONG WITH A THIN LAYER WHERE THETA-E
DECREASES WITH HEIGHT. GIVEN THIS CANNOT RULE OUT SOME THUNDER BUT
COVERAGE AND CONFIDENCE OF OCCURRENCE REMAINS TOO LOW TO INCLUDE A
THUNDER MENTION IN GRIDS. NORTHERLY TRACK OF THIS PHASED SYSTEM
WILL ALLOW SOME WARMER AIR ALOFT TO WORK INTO AREAS SOUTH/ALONG
THE HWY 24 CORRIDOR WHERE PRECIP MAY MIX WITH SLEET (AND LOWER CHC
FOR FREEZING RAIN FAR SOUTH) TO START BEFORE DYNAMIC/EVAPORATIVE
COOLING OVERWHELMS SUPPORTING A CHANGEOVER TO ALL SNOW. THIS
SHOULD CUT DOWN ON SNOW TOTAL A BIT HERE...WITH HEAVIEST TOTALS
EXPECTED ACROSS THE FAR NORTH WHERE PIVOT IS EXPECTED UNDER
DEVELOPING 700 MB LOW TRACK. CURRENT EXPECTATIONS ARE FOR A QUICK
4-6" (LOCALIZED 6" PLUS AMOUNTS POSSIBLE) OF SNOW NORTHWEST OF HWY
24...3-5" ALONG HWY 24...AND 2-4" SOUTHEAST OF HWY 24. STRONG RISE
FALL COUPLET OVERSPREADS THIS EVENING INTO THE EARLY OVERNIGHT
HOURS WHICH MAY CREATE SOME BLOWING/DRIFTING SNOW FOR A TIME.
AS FOR THE NEAR TERM (THIS MORNING INTO EARLY AFTN)...6-8 MB SFC 3
HR PRESSURE FALLS WILL ALLOW WINDS TO PICK UP AND GUST TO BTW 25-30
MPH LATER THIS MORNING. THIS MAY LEAD TO SOME BLOWING AND DRIFTING
IN RURAL/OPEN AREAS. CHANCES FOR SNOW INCREASE WITH TIME AS 850-700
MB THETA-E GRADIENT SHIFTS EAST INTO WESTERN AREAS THIS MORNING.
BAND OF SNOW TRYING TO GET STARTED ALONG THIS GRADIENT ACROSS
SOUTHERN WI/NORTHERN IL AS OF THIS WRITING BUT LOSING THE BATTLE TO
DRY SUB-CLOUD LAYER AT THIS TIME. RAP SATURATES OVER THE AREA WITH
RELATIVE NARROW OF SNOW DEVELOPING OVER WESTERN ZONES BTW 15-18Z
WHILE THE 06Z NAM SLOWER AFTER 18Z. OPTED FOR CHC POPS GIVEN THE
UNCERTAINTY.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 343 AM EST MON FEB 17 2014
FOR TUESDAY...QUIET WEATHER IN STORE WITH DEPARTURE OF MONDAYS SNOW
PRODUCER...AS SHORT WAVE UPPER RIDGING TRACKS ACROSS THE GREAT
LAKES. MID/UPPER LEVEL PATTERN TO BE QUITE PROGRESSIVE THROUGH MID
WEEK AS LOWER AMPLITUDE WAVE TRACKS ACROSS NORTHERN PLAINS/NORTHERN
GREAT LAKES EVENTUALLY ALLOWING SFC TROUGH/COLD FRONT PASSAGE INTO
THE AREA TUESDAY NIGHT/EARLY WEDNESDAY MORNING. LOW LEVEL HEIGHT
GRADIENT SHOULD STEADILY STRENGTHEN ON TUESDAY IN ADVANCE OF THIS
TROUGH WHICH SHOULD ALLOW FOR SOUTH WINDS TO INCREASE BY MIDDAY.
CURRENTLY EXPECTING GUSTS UP TO AROUND 25 MPH WHICH COULD CREATE
SOME DRIFTING CONCERNS EARLY TUESDAY AFTERNOON ACROSS OPEN AREAS FOR
ESPECIALLY EAST TO WEST ORIENTED ROADWAYS. RELATIVELY LOWER SNOW TO
LIQUID RATIOS AND SFC TEMPS WARMING TO ABOVE FREEZING IN THE
AFTERNOON SHOULD TEND TO MITIGATE THIS CONCERN HOWEVER. THE
RELATIVELY DRY AIR MASS IN PLACE SHOULD LIMIT ANY MEASURABLE PRECIP
CHANCES IN ASSOCIATION WITH THE FRONT TUESDAY NIGHT...ALTHOUGH GIVEN
MOISTURE PROFILES AND WEAK LIFT CANNOT COMPLETELY RULE OUT SOME VERY
LIGHT PATCHY FREEZING DRIZZLE FOR A BRIEF TIME IN IMMEDIATE VICINITY
OF THE FRONT.
WEAK THERMAL TROUGH WILL BE IN PLACE ACROSS THE AREA FOR WEDNESDAY
BEHIND THIS FRONT...WITH EVENTUAL ONSET OF STRONGER LOW LEVEL WAA
AGAIN TOWARD WEDNESDAY EVENING AS LOW LEVEL ANTICYCLONE SHIFTS TO
THE MID ATLANTIC STATES. PRESENCE OF LOW LEVEL THERMAL TROUGH AND
VERY SHALLOW MIXED LAYER DEPTHS SHOULD RESULT IN HIGHS A DEGREE OR
TWO LOWER THAN TUESDAY AFTERNOON...ALTHOUGH STILL INTO AT LEAST MID
30S MOST LOCATIONS. WITH DAYTIME TEMPS MARGINALLY ABOVE FREEZING AND
NIGHTTIME TEMPS EXPECTED TO DROP BELOW FREEZING TUESDAY
NIGHT/WEDNESDAY NIGHT...SNOWMELT WILL BE VERY GRADUAL AND NO
SIGNIFICANT HYDROLOGIC IMPACTS ARE EXPECTED THROUGH MIDWEEK.
CONCERN FOR THURSDAY WILL THEN SHIFT TO WARMING TREND AND POTENTIAL
FOR SIGNIFICANT RAINFALL WHICH WILL LEAD TO INCREASED FLOOD
POTENTIAL. BULK OF GUIDANCE HAS NOW SHIFTED BACK TO TREND OF SEVERAL
DAYS AGO IN DEPICTING TWO DISTINCT EASTERN PACIFIC WAVES PHASING
ACROSS THE UPPER MIDWEST/NORTHERN GREAT LAKES...AND PROMOTING
STRONGER CYCLOGENESIS ACROSS THE WESTERN GREAT LAKES FOR THURSDAY.
DETAILS STILL DIFFICULT TO PIN DOWN AT THIS POINT WITH HOW THESE
WAVES WILL INTERACT AND EXTENT/TIMING OF LOW LEVEL DEEPENING...BUT
HAVE SLIGHTLY TRENDED FORECAST TO THIS STRONGER EVOLUTION. STRONG
LOW LEVEL THETAE ADVECTION/MOISTURE TRANSPORT TO RACE NORTHEASTWARD
INTO THE LOCAL AREA BY THURSDAY MORNING WITH PTYPE CONCERNS LIKELY
TO EXIST AT ONSET OF PRECIP. A BRIEF PERIOD OF -SN/-FZRA IS POSSIBLE
THURSDAY MORNING BEFORE STRENGTH OF LOW LEVEL ADVECTION OVERWHELMS
PROFILES AND SUPPORTS LIQUID PRECIP TYPE. AFTER THIS INITIAL
WARM/MOIST ADVECTIVE SURGE THURSDAY...ITEM OF LOWER CONFIDENCE WILL
BE POTENTIAL FOR ANY ADDITIONAL PRECIP INTO THURSDAY EVENING THAT
MAY HAVE SOME CONVECTIVE NATURE DEPENDING ON EXACT EVOLUTION OF
PATTERN. THIS WILL NEED TO BE WATCHED FOR POTENTIAL HIGHER RAINFALL
AMOUNTS THAT WILL IMPACT FLOOD POTENTIAL...ESPECIALLY IN LIGHT OF
SFC DEW POINTS LIKELY RISING INTO THE UPPER 30S TO LOWER 40S THAT
WILL ACCELERATE SNOWMELT. LARGER SCALE FRONTAL FORCING MAY ALLOW
RAIN TO PERSIST THROUGH MUCH OF THURSDAY NIGHT...ESPECIALLY ACROSS
EASTERN HALF OF THE AREA. COLDER AIR TO ADVECT BACK INTO THE REGION
FOR FRIDAY BEHIND THIS SYSTEM THAT MAY PROVIDE SOME BENEFIT TO
RUNOFF FROM RECENT RAIN/MELTING SNOW. WILL CONTINUE WITH ESF THIS
MORNING HIGHLIGHTING OVERALL POTENTIAL...BUT MUCH OF THIS WILL
DEPEND ON EXACT RAINFALL AMOUNTS THURSDAY ALONG WITH HOW QUICKLY
UPSTREAM SYSTEM PHASES WHICH WILL BE CRITICAL FOR TEMP/DEW PT
TRENDS.
PREDICTABILITY IN SMALLER SCALE WAVES IMPACTING THE AREA FOR THE
WEEKEND STILL QUITE LOW AT THIS TIME...ALTHOUGH NEW 00Z GUIDANCE
STILL SUPPORTS IDEA OF DEEPER MOISTURE SHUNTED WELL SOUTH OF THE
AREA. HAVE CONTINUED PREVIOUS LOW CHANCE -SN/RA POPS FOR THE WEEKEND
WITH A SERIES OF LOW LEVEL AMPLITUDE CLIPPER SYSTEMS POSSIBLE
THROUGH THE EARLY PORTIONS OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1229 AM EST MON FEB 17 2014
SATELLITE AND OBSERVATION TRENDS SHOW MVFR STRATO CU DECK ERODING
AND SINKING SOUTH AS OF THIS WRITING. LIGHT EASTERLY WINDS AND
INCREASING HIGH LEVEL CLOUDS SHOULD BE ENOUGH TO PRECLUDE
SIGNIFICANT VIS RESTRICTIONS AT THE THERMIANALS THIS MORNING.
ATTENTION THIS AFTN/EVE WILL TURN TO TIMING OF 4-6 HR PERIOD OF
MODERATE/HEAVY SNOW AS VERY DYNAMIC/STRONG UPPER LEVEL SYSTEM
LIFTS INTO THE AREA. LATEST GUIDANCE HAS TRENDED A LITTLE SLOWER
WITH THIS INCORPORATED INTO 06Z TAFS. OTHERWISE...IMPRESSIVE
PRESSURE FALLS TODAY WILL RESULT IN A BREEZY DAY WITH SHALLOW
MIXING GENERALLY HOLDING GUSTS TO LESS THAN 30 KNOTS BEFORE
DIMINISHING LATE AFTN/EARLY EVE AS SFC LOW CENTER TRACKS INTO
NORTHERN INDIANA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM EST
TUESDAY FOR INZ006>009-017-018-025>027-032>034.
WINTER WEATHER ADVISORY FROM NOON EST /11 AM CST/ TODAY TO 11 PM
EST /10 PM CST/ THIS EVENING FOR INZ003>005-012>016-020-
022>024.
MI...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM EST
TUESDAY FOR MIZ079>081.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 11 PM EST THIS
EVENING FOR MIZ077-078.
OH...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM EST
TUESDAY FOR OHZ001-002-004-005-015-016-024-025.
LM...NONE.
&&
$$
SYNOPSIS...JT
SHORT TERM...STEINWEDEL
LONG TERM...MARSILI
AVIATION...STEINWEDEL
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
542 PM MST TUE FEB 18 2014
.UPDATE...
ISSUED AT 542 PM MST TUE FEB 18 2014
RED FLAG CONDITIONS ARE NO LONGER BEING MET. WENT AHEAD AND
CANCELLED THE RED FLAG WARNING EARLY.
UPDATE ISSUED AT 429 PM MST TUE FEB 18 2014
WENT AHEAD AND CANCELLED THE WIND ADVISORY EARLY. WINDS HAVE
DROPPED BELOW CRITERIA AND SHOULD CONTINUE DIMINISHING THIS
EVENING. SOME LOCATIONS ARE STILL MEETING RED FLAG WARNING
CRITERIA SO HAVE LEFT THAT HIGHLIGHT GOING FOR NOW. WILL REASSESS
THE NEED FOR IT AT THE TOP OF THE HOUR WHEN THE NEW OBSERVATIONS
COME IN.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 145 PM MST TUE FEB 18 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS INDICATE SHORTWAVE TROUGH OVER
EASTERN NEBRASKA/KANSAS WITH SHORTWAVE RIDGE OVER THE GREAT BASIN
AND NORTHERN ROCKIES. A COLD FRONT (WHICH SHOWS UP BETTER WITH
VERTICAL THICKNESS FIELD) IS MOVING SOUTH TO THE KS/NE BORDER WITH A
PREFRONTAL SURFACE TROUGH AXIS NOW ACROSS CENTRAL KANSAS.
THIS AFTERNOON...STRONG PRESSURE GRADIENT HAS LED TO DEVELOPMENT OF
WIND GUSTS 45-60 MPH ACROSS THE NORTHERN HALF OF THE CWA...WITH
WINDS JUST STARTING TO COME UP ACROSS THE EAST AND SOUTH OVER THE
LAST HOUR. STRONGEST GUSTS WERE ASSOCIATED WITH INITIAL SURGE AS
SURFACE TROUGH SHIFTED SOUTH AND 3HR PRESSURE RISES BEHIND COLD
FRONT PEAKED AROUND 4MB. WINDS HAVE STABILIZED WITHIN ADVISORY
CRITERIA AFTER THIS INITIAL SURGE...SO DECISION WAS MADE TO HOLD
ONTO ADVISORY. RED FLAG CONDITIONS ARE BEING MET AT MOST OF WARNED
AREA...THOUGH INCREASING TD VALUES FROM THE NORTH ARE KEEPING RH
VALUES CLOSER TO 30 PERCENT ACROSS THE NORTHERN PART OF THE RFW. WE
MAY NOT MEET THE HIGH END THRESHOLD FOR RED FLAG CONDITIONS...
HOWEVER WITH THE MAGNITUDE OF WIND...I SEE NO REASON TO MAKE A CHANGE
TO GOING HEADLINES AT THIS POINT. RFW/NPW WILL CONTINUE THROUGH 01Z.
TONIGHT-WEDNESDAY...WINDS WILL QUICKLY DECREASE WITH LOSS OF DAYTIME
MIXING AND WEAKENING GRADIENT THIS EVENING. HIGH CLOUD COVER MOVING
IN FROM THE WEST LATER THIS EVENING MAY LIMIT RADIATIONAL COOLING
TONIGHT AND DIURNAL HEATING WEDNESDAY. LEE TROUGH ALSO REDEVELOPS
AFTER MIDNIGHT TONIGHT IN RESPONSE TO STRONG TROUGH MOVING OUT OF
THE PACIFIC NORTHWEST...WITH RESULTING SOUTHERLY FLOW SUPPORTING WAA
ACROSS THE WEST. I BUMPED LOW TEMPS UP TONIGHT AND HIGH TEMPS UP WED
FOR NOW...AND COULD SEE BOTH PERIODS BEING A LITTLE WARMER/COOLER
THAN ADVERTISED DEPENDING ON CLOUDS. OTHER IMMEDIATE CONCERN WILL BE
BREEZY-WINDY CONDITIONS WEDNESDAY AS SOUTHERLY GRADIENT INCREASE
AHEAD OF APPROACHING UPPER LEVEL SYSTEM. MODEL TEMPERATURE PROFILES
INDICATE MIXING HEIGHTS AROUND 750MB-800MB WHICH KEEPS WINDS JUST
UNDER (OR NEAR) ADVISORY CRITERIA...AND WITH CLOUD COVER POSSIBLY
LIMITING MIXING OVERALL...I DECIDED AGAINST ISSUANCE OF ANOTHER
ADVISORY WED AFTERNOON. UPPER LEVEL SYSTEM DOES APPROACH CENTRAL
ROCKIES WED AFTERNOON AND SURFACE TROUGH WILL SHIFT EAST ALLOWING
WINDS TO DECREASE LATER IN THE AFTERNOON. WHILE FORCING DOES BEGIN
TO INCREASE OVER THE ROCKIES...IT CURRENTLY LOOKS LIKE PRECIP
CHANCES SHOULD HOLD OFF UNTIL WED EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 224 PM MST TUE FEB 18 2014
FORECAST CONCERNS WILL BE WINDS THROUGH FRIDAY AND PRECIPITATION
CHANCE/PHASE WEDNESDAY NIGHT. SATELLITE SHOWING A PROGRESSIVE AND
ACTIVE WAVE TRAIN FROM THE PACIFIC INTO THE ATLANTIC. NEXT SHORTWAVE
OF INTEREST IS ENTERING THE PACIFIC NORTHWEST. VERY DRY AIR MASS
ALOFT AT THIS TIME.
AT JET LEVEL...MODELS STARTED OUT FINE. AT MID LEVELS...LOOKS TO BE
NO SERIOUS INITIALIZATION PROBLEMS WITH THE MODELS MAYBE A LITTLE
TOO FAR SOUTH AND EAST. AT THIS TIME...THE ECMWF...CANADIAN...UKMET
AND GFS APPEAR TO BE DOING SLIGHTLY BETTER. ECMWF AND SREF WERE
DOING WELL INITIALLY WITH THE SURFACE WIND AND PRESSURE PATTERN.
THE CANADIAN...UKMET AND GFS WERE DOING THE BEST WITH THE LOW LEVEL
THERMAL FIELD.
WEDNESDAY NIGHT...AREA TRANSITIONS FROM WARM...DRY AND WINDY TO
COLD...WET AND WINDY. THERE ARE SOME DIFFERENCES IN THE JET AND
TROUGH POSITION. SOME MODELS HAVE THE LEFT FRONT QUADRANT WELL
SOUTH...AFFECTING THE SOUTHERN HALF OF THE AREA OR STILL TO THE WEST
OF THE AREA. BY THE MIDDLE OF THE NIGHT...THE JET AXIS HAS MOVED
ACROSS WITH THE MAIN AFFECT FROM THE LEFT FRONT QUADRANT ACROSS THE
SOUTHERN HALF OF THE AREA THROUGH THE EVENING. VERY STRONG
FRONTOGENETICAL FORCING MOVES ACROSS THE AREA FROM EARLY IN THE
EVENING TO LATE IN THE NIGHT. THETA-E LAPSE RATES NEAR ZERO OR
SLIGHTLY BELOW ZERO ARE NOT ONLY AT MID LEVELS FOR THE ENTIRE NIGHT
BUT FOR A BRIEF PERIOD ARE AT LOW LEVELS.
SO THE LIKELIHOOD OF PRECIPITATION IS PRETTY HIGH. THE QUESTION
BECOMES WHEN WILL THE PHASE CHANGE FROM RAIN TO SNOW AND HOW MUCH
SNOW WILL OCCUR AFTER THIS HAPPENS. MODEL SOUNDINGS AND WET BULB
PROGS WOULD INDICATE THE NORTHWEST HALF WILL TRANSITION FROM A
RAIN/SNOW MIX EARLY TO ALL SNOW BY 06Z. THE SOUTHEAST HALF WILL
HAVE RAIN UNTIL NEAR 05-06Z BEFORE RAPIDLY CHANGING TO SNOW.
PRECIPITABLE WATER NEARS A HALF INCH OVER THE EASTERN HALF TO TWO
THIRDS OF THE AREA. LIKE THE REPRESENTATION OF QPF THAT WPC HAS AND
USED AS A THE BUILDING BLOCK FOR THE QPF AND SNOWFALL. WPC SLR
GUIDANCE WOULD INDICATE A NEAR 13 TO 1 RATIO IS NEAR NORMAL AND THAT
SEEMS REASONABLE. SO CONSIDERING THE FORCING AND INSTABILITY...THE
SNOW COULD BE RATHER INTENSE AT TIMES DURING THE NIGHT.
SO WITH USING THE WPC QPF AND CUTTING OFF A LITTLE BIT DUE TO THE
EXPECTED PHASE TO BE RAIN...CAME UP WITH 1 TO 4 INCHES WITH THE
LOWEST IN THE FAR SOUTH AND THE MOST FROM YUMA COUNTY TO THE COUNTIES
ALONG THE KANSAS AND NEBRASKA BORDER.
ALL INDICATIONS ARE THAT VERY WINDY CONDITIONS WILL BE A CERTAINTY.
EXTREMELY TIGHT PRESSURE GRADIENT AND 3 HOUR PRESSURE RISES OF NEAR
10 MB WILL PRODUCE VERY WINDY CONDITIONS. AND THAT IS NOT EVEN
CONSIDERING THE POSSIBILITY OF MIXING DOWN EVEN STRONGER WINDS.
THOUGHT LONG AND HARD ABOUT HOW TO HANDLE THIS SCENARIO. WINDS
SHOULD BE IN THE HIGH WIND ADVISORY TO LOW HIGH WIND WARNING RANGE.
SO DESPITE THE AMOUNT OF SNOW EXPECTED...SIGNIFICANT BLOWING OF THAT
SNOW IS EXPECTED. DUE TO HOW FAST THE SNOW MOVES ACROSS THE AREA...3
HOURS OF BLIZZARD CONDITIONS ARE NOT EXPECTED TO OCCUR WHICH WOULD
MEAN A BLIZZARD WARNING. AFTER PLENTY OF DISCUSSION WE HAVE DECIDED
TO ISSUE A WINTER WEATHER ADVISORY AND EMPHASIZE THAT NEAR BLIZZARD
OR BLIZZARD CONDITIONS COULD OCCUR FOR A SHORT PERIOD OF TIME WITH
VISIBILITIES OF A HALF MILE TO A MILE EXPECTED FOR MOST OF THE
PERIOD. SNOW SHOULD BE DONE BY THE END OF THE NIGHT PLUS THE WINDS
SHOULD GO DOWN BY THAT TIME. SO THE WINTER WEATHER ADVISORY WILL BE
FOR THE WHOLE NIGHT FOR THE NORTHWEST HALF AND FOR THE SOUTHEAST HALF
FOR THE LAST HALF OF THE NIGHT ENDING AT 6 TO 7 AM LOCAL TIME.
THURSDAY/THURSDAY NIGHT...SOME DIFFERENCES IN THE SPEED OF INCOMING
NORTH TO SOUTH JET...BUT IT LOOKS TO BE WEST OF THE AREA THROUGH
THE DAY. THAT SEGMENT FLATTENS OUT WITH A WEST TO EAST JET AXIS AND
RIGHT REAR QUADRANT OVER THE NORTHERN HALF OF THE AREA BY THE END
OF THE NIGHT. AT THIS TIME ALL THE MOISTURE IS ALOFT SO THIS WILL
ONLY CAUSE CLOUDS.
THE BIG PROBLEM WILL BE THAT WINDS WILL COME UP AGAIN DURING THE
DAY BEHIND THE EXITING SHORTWAVE TROUGH. QUESTIONS WILL BE HOW
MUCH MIXING WILL OCCUR...ESPECIALLY IN THE NORTH...DUE TO SNOW ON THE
GROUND. LOOK TO STAY MIXED THROUGH THE NIGHT. DURING THE DAY THERE IS
GOOD UNIDIRECTIONAL FLOW WITH DECENT DOWNWARD MOTION. MODELS SHOW
GOOD LAPSE RATES TO AT LEAST 700 MB. SO IT WOULD APPEAR THINGS WILL
MIX WELL. MODEL SOUNDINGS WOULD INDICATE AT LEAST WIND ADVISORY...
POSSIBLY HIGH END...AND POSSIBLY REACHING HIGH WIND WARNING
CRITERIA. SO WILL KEEP WINDY TO VERY WINDY CONDITIONS AND THIS WILL
NEED TO BE ADDRESSED AFTER THE WINTER WEATHER ADVISORY IS DONE.
DEPENDING ON THE AMOUNT OF SNOW AND HOW MUCH IF ANY THE SNOW CRUSTS
OVER...THERE COULD BE SOME MORE BLOWING SNOW DESPITE NO PRECIPITATION
OCCURRING. SO DID PUT IN PATCHY BLOWING SNOW AT THIS TIME. WILL PUT
MAXES IN NEAR TO SLIGHTLY BELOW GUIDANCE.
FRIDAY...ABOVE JET MOVES SOUTH ACROSS THE AREA AT VARIOUS SPEEDS AND
WILL BE NEAR OR JUST SOUTH OF THE AREA BY THE END OF THE DAY. THIS
JUST LOOKS TO PRODUCE SOME CLOUDS. MODELS SHOWING WIND SPEEDS
INCREASING INTO THE WINDY CATEGORY AGAIN. LAPSE RATES LOOK TO STILL
STAY GOOD BUT THE FLOW IS NOT AS UNIDIRECTIONAL AND THE DOWNWARD
MOTION IS NOT AS GREAT. BUFKIT SOUNDINGS ARE INDICATING THE MIXING
DOWN OF A LEAST WIND ADVISORY CRITERIA WINDS AGAIN. WILL DEFINITELY
TRY AND HAVE WINDY WORDING IN THERE AT THIS TIME. TEMPERATURES
SHOULD BE WARMER BUT NOT SURE DEPENDING ON THE AMOUNT OF SNOW ON THE
GROUND.
FRIDAY NIGHT THROUGH TUESDAY...AT END OF THE SHORT TERM INTO THE
BEGINNING OF THIS PERIOD...THE PATTERN TRANSITIONS FROM A
PROGRESSIVE FLOW TO A HIGH AMPLITUDE RIDGE ALONG THE WEST COAST OF
NORTH AMERICA AND HUDSON BAY LOW BECOMING ESTABLISHED ONCE AGAIN BY
THE END OF THE PERIOD. PRECIPITATION IS VERY HARD TO PIN DOWN. WILL
HAVE VERY FAST WEST TO NORTHWEST FLOW WITH EMBEDDED SHORTWAVE TROUGHS
AND JET ENERGY. SIGNIFICANT MOISTURE WILL BE HARD TO COME BY IN THIS
SCENARIO. HOWEVER CANNOT RULE OUT SOME BRIEF AND SPOTTY PRECIPITATION
CHANCES. SO LEFT THE CRH_INIT POPS ALONE WHICH WERE NO HIGHER THAN
SLIGHT CHANCE WHICH SEEMS REASONABLE.
COLDER TEMPERATURES LOOK TO BE COMING BACK. BY LATE IN THE WEEKEND
A SHALLOW COLD AIR MASS WILL BE IN PLACE AS A SURFACE RIDGE BECOMES
ESTABLISHED OVER THE NORTH CENTRAL PORTION OF THE COUNTRY. SO
FOLLOWED OTHER OFFICES AND MADE SLIGHT ADJUSTMENTS DOWN IN
TEMPERATURES...ESPECIALLY THE MAXES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 412 PM MST TUE FEB 18 2014
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD. SURFACE HIGH
PRESSURE WILL SETTLE IN OVER BOTH TERMINALS TONIGHT...ALLOWING
WINDS TO BECOME LIGHT AND VARIABLE. AS THE SURFACE HIGH MOVES
EAST...SOUTHERLY SURFACE WINDS WILL SET UP OVER THE TERMINALS WITH
WINDS INCREASING TO 20 TO 25 KTS SUSTAINED AND GUSTS UP TO 35 KTS
IN THE LATE MORNING INTO THE AFTERNOON. A STRONG COLD FRONT WILL
MOVE INTO THE TERMINALS AFTER THIS TAF PERIOD...SO WILL LEAVE THE
WIND SHIFT AND LOWERING CEILINGS FOR LATER TAF ISSUANCES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ WEDNESDAY TO 6
AM MST /7 AM CST/ THURSDAY FOR KSZ001-002-013-027.
WINTER WEATHER ADVISORY FROM 10 PM MST /11 PM CST/ WEDNESDAY TO
6 AM MST /7 AM CST/ THURSDAY FOR KSZ003-004-014>016-028-029-
041-042.
CO...WINTER WEATHER ADVISORY FROM 7 PM WEDNESDAY TO 6 AM MST THURSDAY
FOR COZ090>092.
NE...WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ WEDNESDAY TO 6
AM MST /7 AM CST/ THURSDAY FOR NEZ079>081.
&&
$$
UPDATE...RRH
SHORT TERM...DJR
LONG TERM...BULLER
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
429 PM MST TUE FEB 18 2014
.UPDATE...
ISSUED AT 429 PM MST TUE FEB 18 2014
WENT AHEAD AND CANCELLED THE WIND ADVISORY EARLY. WINDS HAVE
DROPPED BELOW CRITERIA AND SHOULD CONTINUE DIMINISHING THIS
EVENING. SOME LOCATIONS ARE STILL MEETING RED FLAG WARNING
CRITERIA SO HAVE LEFT THAT HIGHLIGHT GOING FOR NOW. WILL REASSESS
THE NEED FOR IT AT THE TOP OF THE HOUR WHEN THE NEW OBSERVATIONS
COME IN.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 145 PM MST TUE FEB 18 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS INDICATE SHORTWAVE TROUGH OVER
EASTERN NEBRASKA/KANSAS WITH SHORTWAVE RIDGE OVER THE GREAT BASIN
AND NORTHERN ROCKIES. A COLD FRONT (WHICH SHOWS UP BETTER WITH
VERTICAL THICKNESS FIELD) IS MOVING SOUTH TO THE KS/NE BORDER WITH A
PREFRONTAL SURFACE TROUGH AXIS NOW ACROSS CENTRAL KANSAS.
THIS AFTERNOON...STRONG PRESSURE GRADIENT HAS LED TO DEVELOPMENT OF
WIND GUSTS 45-60 MPH ACROSS THE NORTHERN HALF OF THE CWA...WITH
WINDS JUST STARTING TO COME UP ACROSS THE EAST AND SOUTH OVER THE
LAST HOUR. STRONGEST GUSTS WERE ASSOCIATED WITH INITIAL SURGE AS
SURFACE TROUGH SHIFTED SOUTH AND 3HR PRESSURE RISES BEHIND COLD
FRONT PEAKED AROUND 4MB. WINDS HAVE STABILIZED WITHIN ADVISORY
CRITERIA AFTER THIS INITIAL SURGE...SO DECISION WAS MADE TO HOLD
ONTO ADVISORY. RED FLAG CONDITIONS ARE BEING MET AT MOST OF WARNED
AREA...THOUGH INCREASING TD VALUES FROM THE NORTH ARE KEEPING RH
VALUES CLOSER TO 30 PERCENT ACROSS THE NORTHERN PART OF THE RFW. WE
MAY NOT MEET THE HIGH END THRESHOLD FOR RED FLAG CONDITIONS...
HOWEVER WITH THE MAGNITUDE OF WIND...I SEE NO REASON TO MAKE A CHANGE
TO GOING HEADLINES AT THIS POINT. RFW/NPW WILL CONTINUE THROUGH 01Z.
TONIGHT-WEDNESDAY...WINDS WILL QUICKLY DECREASE WITH LOSS OF DAYTIME
MIXING AND WEAKENING GRADIENT THIS EVENING. HIGH CLOUD COVER MOVING
IN FROM THE WEST LATER THIS EVENING MAY LIMIT RADIATIONAL COOLING
TONIGHT AND DIURNAL HEATING WEDNESDAY. LEE TROUGH ALSO REDEVELOPS
AFTER MIDNIGHT TONIGHT IN RESPONSE TO STRONG TROUGH MOVING OUT OF
THE PACIFIC NORTHWEST...WITH RESULTING SOUTHERLY FLOW SUPPORTING WAA
ACROSS THE WEST. I BUMPED LOW TEMPS UP TONIGHT AND HIGH TEMPS UP WED
FOR NOW...AND COULD SEE BOTH PERIODS BEING A LITTLE WARMER/COOLER
THAN ADVERTISED DEPENDING ON CLOUDS. OTHER IMMEDIATE CONCERN WILL BE
BREEZY-WINDY CONDITIONS WEDNESDAY AS SOUTHERLY GRADIENT INCREASE
AHEAD OF APPROACHING UPPER LEVEL SYSTEM. MODEL TEMPERATURE PROFILES
INDICATE MIXING HEIGHTS AROUND 750MB-800MB WHICH KEEPS WINDS JUST
UNDER (OR NEAR) ADVISORY CRITERIA...AND WITH CLOUD COVER POSSIBLY
LIMITING MIXING OVERALL...I DECIDED AGAINST ISSUANCE OF ANOTHER
ADVISORY WED AFTERNOON. UPPER LEVEL SYSTEM DOES APPROACH CENTRAL
ROCKIES WED AFTERNOON AND SURFACE TROUGH WILL SHIFT EAST ALLOWING
WINDS TO DECREASE LATER IN THE AFTERNOON. WHILE FORCING DOES BEGIN
TO INCREASE OVER THE ROCKIES...IT CURRENTLY LOOKS LIKE PRECIP
CHANCES SHOULD HOLD OFF UNTIL WED EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 224 PM MST TUE FEB 18 2014
FORECAST CONCERNS WILL BE WINDS THROUGH FRIDAY AND PRECIPITATION
CHANCE/PHASE WEDNESDAY NIGHT. SATELLITE SHOWING A PROGRESSIVE AND
ACTIVE WAVE TRAIN FROM THE PACIFIC INTO THE ATLANTIC. NEXT SHORTWAVE
OF INTEREST IS ENTERING THE PACIFIC NORTHWEST. VERY DRY AIR MASS
ALOFT AT THIS TIME.
AT JET LEVEL...MODELS STARTED OUT FINE. AT MID LEVELS...LOOKS TO BE
NO SERIOUS INITIALIZATION PROBLEMS WITH THE MODELS MAYBE A LITTLE
TOO FAR SOUTH AND EAST. AT THIS TIME...THE ECMWF...CANADIAN...UKMET
AND GFS APPEAR TO BE DOING SLIGHTLY BETTER. ECMWF AND SREF WERE
DOING WELL INITIALLY WITH THE SURFACE WIND AND PRESSURE PATTERN.
THE CANADIAN...UKMET AND GFS WERE DOING THE BEST WITH THE LOW LEVEL
THERMAL FIELD.
WEDNESDAY NIGHT...AREA TRANSITIONS FROM WARM...DRY AND WINDY TO
COLD...WET AND WINDY. THERE ARE SOME DIFFERENCES IN THE JET AND
TROUGH POSITION. SOME MODELS HAVE THE LEFT FRONT QUADRANT WELL
SOUTH...AFFECTING THE SOUTHERN HALF OF THE AREA OR STILL TO THE WEST
OF THE AREA. BY THE MIDDLE OF THE NIGHT...THE JET AXIS HAS MOVED
ACROSS WITH THE MAIN AFFECT FROM THE LEFT FRONT QUADRANT ACROSS THE
SOUTHERN HALF OF THE AREA THROUGH THE EVENING. VERY STRONG
FRONTOGENETICAL FORCING MOVES ACROSS THE AREA FROM EARLY IN THE
EVENING TO LATE IN THE NIGHT. THETA-E LAPSE RATES NEAR ZERO OR
SLIGHTLY BELOW ZERO ARE NOT ONLY AT MID LEVELS FOR THE ENTIRE NIGHT
BUT FOR A BRIEF PERIOD ARE AT LOW LEVELS.
SO THE LIKELIHOOD OF PRECIPITATION IS PRETTY HIGH. THE QUESTION
BECOMES WHEN WILL THE PHASE CHANGE FROM RAIN TO SNOW AND HOW MUCH
SNOW WILL OCCUR AFTER THIS HAPPENS. MODEL SOUNDINGS AND WET BULB
PROGS WOULD INDICATE THE NORTHWEST HALF WILL TRANSITION FROM A
RAIN/SNOW MIX EARLY TO ALL SNOW BY 06Z. THE SOUTHEAST HALF WILL
HAVE RAIN UNTIL NEAR 05-06Z BEFORE RAPIDLY CHANGING TO SNOW.
PRECIPITABLE WATER NEARS A HALF INCH OVER THE EASTERN HALF TO TWO
THIRDS OF THE AREA. LIKE THE REPRESENTATION OF QPF THAT WPC HAS AND
USED AS A THE BUILDING BLOCK FOR THE QPF AND SNOWFALL. WPC SLR
GUIDANCE WOULD INDICATE A NEAR 13 TO 1 RATIO IS NEAR NORMAL AND THAT
SEEMS REASONABLE. SO CONSIDERING THE FORCING AND INSTABILITY...THE
SNOW COULD BE RATHER INTENSE AT TIMES DURING THE NIGHT.
SO WITH USING THE WPC QPF AND CUTTING OFF A LITTLE BIT DUE TO THE
EXPECTED PHASE TO BE RAIN...CAME UP WITH 1 TO 4 INCHES WITH THE
LOWEST IN THE FAR SOUTH AND THE MOST FROM YUMA COUNTY TO THE COUNTIES
ALONG THE KANSAS AND NEBRASKA BORDER.
ALL INDICATIONS ARE THAT VERY WINDY CONDITIONS WILL BE A CERTAINTY.
EXTREMELY TIGHT PRESSURE GRADIENT AND 3 HOUR PRESSURE RISES OF NEAR
10 MB WILL PRODUCE VERY WINDY CONDITIONS. AND THAT IS NOT EVEN
CONSIDERING THE POSSIBILITY OF MIXING DOWN EVEN STRONGER WINDS.
THOUGHT LONG AND HARD ABOUT HOW TO HANDLE THIS SCENARIO. WINDS
SHOULD BE IN THE HIGH WIND ADVISORY TO LOW HIGH WIND WARNING RANGE.
SO DESPITE THE AMOUNT OF SNOW EXPECTED...SIGNIFICANT BLOWING OF THAT
SNOW IS EXPECTED. DUE TO HOW FAST THE SNOW MOVES ACROSS THE AREA...3
HOURS OF BLIZZARD CONDITIONS ARE NOT EXPECTED TO OCCUR WHICH WOULD
MEAN A BLIZZARD WARNING. AFTER PLENTY OF DISCUSSION WE HAVE DECIDED
TO ISSUE A WINTER WEATHER ADVISORY AND EMPHASIZE THAT NEAR BLIZZARD
OR BLIZZARD CONDITIONS COULD OCCUR FOR A SHORT PERIOD OF TIME WITH
VISIBILITIES OF A HALF MILE TO A MILE EXPECTED FOR MOST OF THE
PERIOD. SNOW SHOULD BE DONE BY THE END OF THE NIGHT PLUS THE WINDS
SHOULD GO DOWN BY THAT TIME. SO THE WINTER WEATHER ADVISORY WILL BE
FOR THE WHOLE NIGHT FOR THE NORTHWEST HALF AND FOR THE SOUTHEAST HALF
FOR THE LAST HALF OF THE NIGHT ENDING AT 6 TO 7 AM LOCAL TIME.
THURSDAY/THURSDAY NIGHT...SOME DIFFERENCES IN THE SPEED OF INCOMING
NORTH TO SOUTH JET...BUT IT LOOKS TO BE WEST OF THE AREA THROUGH
THE DAY. THAT SEGMENT FLATTENS OUT WITH A WEST TO EAST JET AXIS AND
RIGHT REAR QUADRANT OVER THE NORTHERN HALF OF THE AREA BY THE END
OF THE NIGHT. AT THIS TIME ALL THE MOISTURE IS ALOFT SO THIS WILL
ONLY CAUSE CLOUDS.
THE BIG PROBLEM WILL BE THAT WINDS WILL COME UP AGAIN DURING THE
DAY BEHIND THE EXITING SHORTWAVE TROUGH. QUESTIONS WILL BE HOW
MUCH MIXING WILL OCCUR...ESPECIALLY IN THE NORTH...DUE TO SNOW ON THE
GROUND. LOOK TO STAY MIXED THROUGH THE NIGHT. DURING THE DAY THERE IS
GOOD UNIDIRECTIONAL FLOW WITH DECENT DOWNWARD MOTION. MODELS SHOW
GOOD LAPSE RATES TO AT LEAST 700 MB. SO IT WOULD APPEAR THINGS WILL
MIX WELL. MODEL SOUNDINGS WOULD INDICATE AT LEAST WIND ADVISORY...
POSSIBLY HIGH END...AND POSSIBLY REACHING HIGH WIND WARNING
CRITERIA. SO WILL KEEP WINDY TO VERY WINDY CONDITIONS AND THIS WILL
NEED TO BE ADDRESSED AFTER THE WINTER WEATHER ADVISORY IS DONE.
DEPENDING ON THE AMOUNT OF SNOW AND HOW MUCH IF ANY THE SNOW CRUSTS
OVER...THERE COULD BE SOME MORE BLOWING SNOW DESPITE NO PRECIPITATION
OCCURRING. SO DID PUT IN PATCHY BLOWING SNOW AT THIS TIME. WILL PUT
MAXES IN NEAR TO SLIGHTLY BELOW GUIDANCE.
FRIDAY...ABOVE JET MOVES SOUTH ACROSS THE AREA AT VARIOUS SPEEDS AND
WILL BE NEAR OR JUST SOUTH OF THE AREA BY THE END OF THE DAY. THIS
JUST LOOKS TO PRODUCE SOME CLOUDS. MODELS SHOWING WIND SPEEDS
INCREASING INTO THE WINDY CATEGORY AGAIN. LAPSE RATES LOOK TO STILL
STAY GOOD BUT THE FLOW IS NOT AS UNIDIRECTIONAL AND THE DOWNWARD
MOTION IS NOT AS GREAT. BUFKIT SOUNDINGS ARE INDICATING THE MIXING
DOWN OF A LEAST WIND ADVISORY CRITERIA WINDS AGAIN. WILL DEFINITELY
TRY AND HAVE WINDY WORDING IN THERE AT THIS TIME. TEMPERATURES
SHOULD BE WARMER BUT NOT SURE DEPENDING ON THE AMOUNT OF SNOW ON THE
GROUND.
FRIDAY NIGHT THROUGH TUESDAY...AT END OF THE SHORT TERM INTO THE
BEGINNING OF THIS PERIOD...THE PATTERN TRANSITIONS FROM A
PROGRESSIVE FLOW TO A HIGH AMPLITUDE RIDGE ALONG THE WEST COAST OF
NORTH AMERICA AND HUDSON BAY LOW BECOMING ESTABLISHED ONCE AGAIN BY
THE END OF THE PERIOD. PRECIPITATION IS VERY HARD TO PIN DOWN. WILL
HAVE VERY FAST WEST TO NORTHWEST FLOW WITH EMBEDDED SHORTWAVE TROUGHS
AND JET ENERGY. SIGNIFICANT MOISTURE WILL BE HARD TO COME BY IN THIS
SCENARIO. HOWEVER CANNOT RULE OUT SOME BRIEF AND SPOTTY PRECIPITATION
CHANCES. SO LEFT THE CRH_INIT POPS ALONE WHICH WERE NO HIGHER THAN
SLIGHT CHANCE WHICH SEEMS REASONABLE.
COLDER TEMPERATURES LOOK TO BE COMING BACK. BY LATE IN THE WEEKEND
A SHALLOW COLD AIR MASS WILL BE IN PLACE AS A SURFACE RIDGE BECOMES
ESTABLISHED OVER THE NORTH CENTRAL PORTION OF THE COUNTRY. SO
FOLLOWED OTHER OFFICES AND MADE SLIGHT ADJUSTMENTS DOWN IN
TEMPERATURES...ESPECIALLY THE MAXES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 412 PM MST TUE FEB 18 2014
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD. SURFACE HIGH
PRESSURE WILL SETTLE IN OVER BOTH TERMINALS TONIGHT...ALLOWING
WINDS TO BECOME LIGHT AND VARIABLE. AS THE SURFACE HIGH MOVES
EAST...SOUTHERLY SURFACE WINDS WILL SET UP OVER THE TERMINALS WITH
WINDS INCREASING TO 20 TO 25 KTS SUSTAINED AND GUSTS UP TO 35 KTS
IN THE LATE MORNING INTO THE AFTERNOON. A STRONG COLD FRONT WILL
MOVE INTO THE TERMINALS AFTER THIS TAF PERIOD...SO WILL LEAVE THE
WIND SHIFT AND LOWERING CEILINGS FOR LATER TAF ISSUANCES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
KSZ001>004-013>016-027>029-041-042.
WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ WEDNESDAY TO 6
AM MST /7 AM CST/ THURSDAY FOR KSZ001-002-013-027.
WINTER WEATHER ADVISORY FROM 10 PM MST /11 PM CST/ WEDNESDAY TO
6 AM MST /7 AM CST/ THURSDAY FOR KSZ003-004-014>016-028-029-
041-042.
CO...RED FLAG WARNING UNTIL 6 PM MST THIS EVENING FOR COZ252>254.
WINTER WEATHER ADVISORY FROM 7 PM WEDNESDAY TO 6 AM MST THURSDAY
FOR COZ090>092.
NE...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
NEZ079>081.
WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ WEDNESDAY TO 6
AM MST /7 AM CST/ THURSDAY FOR NEZ079>081.
&&
$$
UPDATE...RRH
SHORT TERM...DJR
LONG TERM...BULLER
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
421 PM MST TUE FEB 18 2014
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 145 PM MST TUE FEB 18 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS INDICATE SHORTWAVE TROUGH OVER
EASTERN NEBRASKA/KANSAS WITH SHORTWAVE RIDGE OVER THE GREAT BASIN
AND NORTHERN ROCKIES. A COLD FRONT (WHICH SHOWS UP BETTER WITH
VERTICAL THICKNESS FIELD) IS MOVING SOUTH TO THE KS/NE BORDER WITH A
PREFRONTAL SURFACE TROUGH AXIS NOW ACROSS CENTRAL KANSAS.
THIS AFTERNOON...STRONG PRESSURE GRADIENT HAS LED TO DEVELOPMENT OF
WIND GUSTS 45-60 MPH ACROSS THE NORTHERN HALF OF THE CWA...WITH
WINDS JUST STARTING TO COME UP ACROSS THE EAST AND SOUTH OVER THE
LAST HOUR. STRONGEST GUSTS WERE ASSOCIATED WITH INITIAL SURGE AS
SURFACE TROUGH SHIFTED SOUTH AND 3HR PRESSURE RISES BEHIND COLD
FRONT PEAKED AROUND 4MB. WINDS HAVE STABILIZED WITHIN ADVISORY
CRITERIA AFTER THIS INITIAL SURGE...SO DECISION WAS MADE TO HOLD
ONTO ADVISORY. RED FLAG CONDITIONS ARE BEING MET AT MOST OF WARNED
AREA...THOUGH INCREASING TD VALUES FROM THE NORTH ARE KEEPING RH
VALUES CLOSER TO 30 PERCENT ACROSS THE NORTHERN PART OF THE RFW. WE
MAY NOT MEET THE HIGH END THRESHOLD FOR RED FLAG CONDITIONS...
HOWEVER WITH THE MAGNITUDE OF WIND...I SEE NO REASON TO MAKE A CHANGE
TO GOING HEADLINES AT THIS POINT. RFW/NPW WILL CONTINUE THROUGH 01Z.
TONIGHT-WEDNESDAY...WINDS WILL QUICKLY DECREASE WITH LOSS OF DAYTIME
MIXING AND WEAKENING GRADIENT THIS EVENING. HIGH CLOUD COVER MOVING
IN FROM THE WEST LATER THIS EVENING MAY LIMIT RADIATIONAL COOLING
TONIGHT AND DIURNAL HEATING WEDNESDAY. LEE TROUGH ALSO REDEVELOPS
AFTER MIDNIGHT TONIGHT IN RESPONSE TO STRONG TROUGH MOVING OUT OF
THE PACIFIC NORTHWEST...WITH RESULTING SOUTHERLY FLOW SUPPORTING WAA
ACROSS THE WEST. I BUMPED LOW TEMPS UP TONIGHT AND HIGH TEMPS UP WED
FOR NOW...AND COULD SEE BOTH PERIODS BEING A LITTLE WARMER/COOLER
THAN ADVERTISED DEPENDING ON CLOUDS. OTHER IMMEDIATE CONCERN WILL BE
BREEZY-WINDY CONDITIONS WEDNESDAY AS SOUTHERLY GRADIENT INCREASE
AHEAD OF APPROACHING UPPER LEVEL SYSTEM. MODEL TEMPERATURE PROFILES
INDICATE MIXING HEIGHTS AROUND 750MB-800MB WHICH KEEPS WINDS JUST
UNDER (OR NEAR) ADVISORY CRITERIA...AND WITH CLOUD COVER POSSIBLY
LIMITING MIXING OVERALL...I DECIDED AGAINST ISSUANCE OF ANOTHER
ADVISORY WED AFTERNOON. UPPER LEVEL SYSTEM DOES APPROACH CENTRAL
ROCKIES WED AFTERNOON AND SURFACE TROUGH WILL SHIFT EAST ALLOWING
WINDS TO DECREASE LATER IN THE AFTERNOON. WHILE FORCING DOES BEGIN
TO INCREASE OVER THE ROCKIES...IT CURRENTLY LOOKS LIKE PRECIP
CHANCES SHOULD HOLD OFF UNTIL WED EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 224 PM MST TUE FEB 18 2014
FORECAST CONCERNS WILL BE WINDS THROUGH FRIDAY AND PRECIPITATION
CHANCE/PHASE WEDNESDAY NIGHT. SATELLITE SHOWING A PROGRESSIVE AND
ACTIVE WAVE TRAIN FROM THE PACIFIC INTO THE ATLANTIC. NEXT SHORTWAVE
OF INTEREST IS ENTERING THE PACIFIC NORTHWEST. VERY DRY AIR MASS
ALOFT AT THIS TIME.
AT JET LEVEL...MODELS STARTED OUT FINE. AT MID LEVELS...LOOKS TO BE
NO SERIOUS INITIALIZATION PROBLEMS WITH THE MODELS MAYBE A LITTLE
TOO FAR SOUTH AND EAST. AT THIS TIME...THE ECMWF...CANADIAN...UKMET
AND GFS APPEAR TO BE DOING SLIGHTLY BETTER. ECMWF AND SREF WERE
DOING WELL INITIALLY WITH THE SURFACE WIND AND PRESSURE PATTERN.
THE CANADIAN...UKMET AND GFS WERE DOING THE BEST WITH THE LOW LEVEL
THERMAL FIELD.
WEDNESDAY NIGHT...AREA TRANSITIONS FROM WARM...DRY AND WINDY TO
COLD...WET AND WINDY. THERE ARE SOME DIFFERENCES IN THE JET AND
TROUGH POSITION. SOME MODELS HAVE THE LEFT FRONT QUADRANT WELL
SOUTH...AFFECTING THE SOUTHERN HALF OF THE AREA OR STILL TO THE WEST
OF THE AREA. BY THE MIDDLE OF THE NIGHT...THE JET AXIS HAS MOVED
ACROSS WITH THE MAIN AFFECT FROM THE LEFT FRONT QUADRANT ACROSS THE
SOUTHERN HALF OF THE AREA THROUGH THE EVENING. VERY STRONG
FRONTOGENITICAL FORCING MOVES ACROSS THE AREA FROM EARLY IN THE
EVENING TO LATE IN THE NIGHT. THETA-E LAPSE RATES NEAR ZERO OR
SLIGHTLY BELOW ZERO ARE NOT ONLY AT MID LEVELS FOR THE ENTIRE NIGHT
BUT FOR A BRIEF PERIOD ARE AT LOW LEVELS.
SO THE LIKELIHOOD OF PRECIPITATION IS PRETTY HIGH. THE QUESTION
BECOMES WHEN WILL THE PHASE CHANGE FROM RAIN TO SNOW AND HOW MUCH
SNOW WILL OCCUR AFTER THIS HAPPENS. MODEL SOUNDINGS AND WET BULB
PROGS WOULD INDICATE THE NORTHWEST HALF WILL TRANSITION FROM A
RAIN/SNOW MIX EARLY TO ALL SNOW BY 06Z. THE SOUTHEAST HALF WILL
HAVE RAIN UNTIL NEAR 05-06Z BEFORE RAPIDLY CHANGING TO SNOW.
PRECIPITABLE WATER NEARS A HALF INCH OVER THE EASTERN HALF TO TWO
THIRDS OF THE AREA. LIKE THE REPRESENTATION OF QPF THAT WPC HAS AND
USED AS A THE BUILDING BLOCK FOR THE QPF AND SNOWFALL. WPC SLR
GUIDANCE WOULD INDICATE A NEAR 13 TO 1 RATIO IS NEAR NORMAL AND THAT
SEEMS REASONABLE. SO CONSIDERING THE FORCING AND INSTABILITY...THE
SNOW COULD BE RATHER INTENSE AT TIMES DURING THE NIGHT.
SO WITH USING THE WPC QPF AND CUTTING OFF A LITTLE BIT DUE TO THE
EXPECTED PHASE TO BE RAIN...CAME UP WITH 1 TO 4 INCHES WITH THE
LOWEST IN THE FAR SOUTH AND THE MOST FROM YUMA COUNTY TO THE COUNTIES
ALONG THE KANSAS AND NEBRASKA BORDER.
ALL INDICATIONS ARE THAT VERY WINDY CONDITIONS WILL BE A CERTAINTY.
EXTREMELY TIGHT PRESSURE GRADIENT AND 3 HOUR PRESSURE RISES OF NEAR
10 MB WILL PRODUCE VERY WINDY CONDITIONS. AND THAT IS NOT EVEN
CONSIDERING THE POSSIBILITY OF MIXING DOWN EVEN STRONGER WINDS.
THOUGHT LONG AND HARD ABOUT HOW TO HANDLE THIS SCENARIO. WINDS
SHOULD BE IN THE HIGH WIND ADVISORY TO LOW HIGH WIND WARNING RANGE.
SO DESPITE THE AMOUNT OF SNOW EXPECTED...SIGNIFICANT BLOWING OF THAT
SNOW IS EXPECTED. DUE TO HOW FAST THE SNOW MOVES ACROSS THE AREA...3
HOURS OF BLIZZARD CONDITIONS ARE NOT EXPECTED TO OCCUR WHICH WOULD
MEAN A BLIZZARD WARNING. AFTER PLENTY OF DISCUSSION WE HAVE DECIDED
TO ISSUE A WINTER WEATHER ADVISORY AND EMPHASIZE THAT NEAR BLIZZARD
OR BLIZZARD CONDITIONS COULD OCCUR FOR A SHORT PERIOD OF TIME WITH
VISIBILITIES OF A HALF MILE TO A MILE EXPECTED FOR MOST OF THE
PERIOD. SNOW SHOULD BE DONE BY THE END OF THE NIGHT PLUS THE WINDS
SHOULD GO DOWN BY THAT TIME. SO THE WINTER WEATHER ADVISORY WILL BE
FOR THE WHOLE NIGHT FOR THE NORTHWEST HALF AND FOR THE SOUTHEAST HALF
FOR THE LAST HALF OF THE NIGHT ENDING AT 6 TO 7 AM LOCAL TIME.
THURSDAY/THURSDAY NIGHT...SOME DIFFERENCES IN THE SPEED OF INCOMING
NORTH TO SOUTH JET...BUT IT LOOKS TO BE WEST OF THE AREA THROUGH
THE DAY. THAT SEGMENT FLATTENS OUT WITH A WEST TO EAST JET AXIS AND
RIGHT REAR QUADRANT OVER THE NORTHERN HALF OF THE AREA BY THE END
OF THE NIGHT. AT THIS TIME ALL THE MOISTURE IS ALOFT SO THIS WILL
ONLY CAUSE CLOUDS.
THE BIG PROBLEM WILL BE THAT WINDS WILL COME UP AGAIN DURING THE
DAY BEHIND THE EXITING SHORTWAVE TROUGH. QUESTIONS WILL BE HOW
MUCH MIXING WILL OCCUR...ESPECIALLY IN THE NORTH...DUE TO SNOW ON THE
GROUND. LOOK TO STAY MIXED THROUGH THE NIGHT. DURING THE DAY THERE IS
GOOD UNIDIRECTIONAL FLOW WITH DECENT DOWNWARD MOTION. MODELS SHOW
GOOD LAPSE RATES TO AT LEAST 700 MB. SO IT WOULD APPEAR THINGS WILL
MIX WELL. MODEL SOUNDINGS WOULD INDICATE AT LEAST WIND ADVISORY...
POSSIBLY HIGH END...AND POSSIBLY REACHING HIGH WIND WARNING
CRITERIA. SO WILL KEEP WINDY TO VERY WINDY CONDITIONS AND THIS WILL
NEED TO BE ADDRESSED AFTER THE WINTER WEATHER ADVISORY IS DONE.
DEPENDING ON THE AMOUNT OF SNOW AND HOW MUCH IF ANY THE SNOW CRUSTS
OVER...THERE COULD BE SOME MORE BLOWING SNOW DESPITE NO PRECIPITATION
OCCURRING. SO DID PUT IN PATCHY BLOWING SNOW AT THIS TIME. WILL PUT
MAXES IN NEAR TO SLIGHTLY BELOW GUIDANCE.
FRIDAY...ABOVE JET MOVES SOUTH ACROSS THE AREA AT VARIOUS SPEEDS AND
WILL BE NEAR OR JUST SOUTH OF THE AREA BY THE END OF THE DAY. THIS
JUST LOOKS TO PRODUCE SOME CLOUDS. MODELS SHOWING WIND SPEEDS
INCREASING INTO THE WINDY CATEGORY AGAIN. LAPSE RATES LOOK TO STILL
STAY GOOD BUT THE FLOW IS NOT AS UNIDIRECTIONAL AND THE DOWNWARD
MOTION IS NOT AS GREAT. BUFKIT SOUNDINGS ARE INDICATING THE MIXING
DOWN OF A LEAST WIND ADVISORY CRITERIA WINDS AGAIN. WILL DEFINITELY
TRY AND HAVE WINDY WORDING IN THERE AT THIS TIME. TEMPERATURES
SHOULD BE WARMER BUT NOT SURE DEPENDING ON THE AMOUNT OF SNOW ON THE
GROUND.
FRIDAY NIGHT THROUGH TUESDAY...AT END OF THE SHORT TERM INTO THE
BEGINNING OF THIS PERIOD...THE PATTERN TRANSITIONS FROM A
PROGRESSIVE FLOW TO A HIGH AMPLITUDE RIDGE ALONG THE WEST COAST OF
NORTH AMERICA AND HUDSON BAY LOW BECOMING ESTABLISHED ONCE AGAIN BY
THE END OF THE PERIOD. PRECIPITATION IS VERY HARD TO PIN DOWN. WILL
HAVE VERY FAST WEST TO NORTHWEST FLOW WITH EMBEDDED SHORTWAVE TROUGHS
AND JET ENERGY. SIGNIFICANT MOISTURE WILL BE HARD TO COME BY IN THIS
SCENARIO. HOWEVER CANNOT RULE OUT SOME BRIEF AND SPOTTY PRECIPITATION
CHANCES. SO LEFT THE CRH_INIT POPS ALONE WHICH WERE NO HIGHER THAN
SLIGHT CHANCE WHICH SEEMS REASONABLE.
COLDER TEMPERATURES LOOK TO BE COMING BACK. BY LATE IN THE WEEKEND
A SHALLOW COLD AIR MASS WILL BE IN PLACE AS A SURFACE RIDGE BECOMES
ESTABLISHED OVER THE NORTH CENTRAL PORTION OF THE COUNTRY. SO
FOLLOWED OTHER OFFICES AND MADE SLIGHT ADJUSTMENTS DOWN IN
TEMPERATURES...ESPECIALLY THE MAXES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 412 PM MST TUE FEB 18 2014
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD. SURFACE HIGH
PRESSURE WILL SETTLE IN OVER BOTH TERMINALS TONIGHT...ALLOWING
WINDS TO BECOME LIGHT AND VARIABLE. AS THE SURFACE HIGH MOVES
EAST...SOUTHERLY SURFACE WINDS WILL SET UP OVER THE TERMINALS WITH
WINDS INCREASING TO 20 TO 25 KTS SUSTAINED AND GUSTS UP TO 35 KTS
IN THE LATE MORNING INTO THE AFTERNOON. A STRONG COLD FRONT WILL
MOVE INTO THE TERMINALS AFTER THIS TAF PERIOD...SO WILL LEAVE THE
WIND SHIFT AND LOWERING CEILINGS FOR LATER TAF ISSUANCES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
KSZ001>004-013>016-027>029-041-042.
WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ WEDNESDAY TO 6
AM MST /7 AM CST/ THURSDAY FOR KSZ001-002-013-027.
WIND ADVISORY UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
KSZ001>004-013>016-027>029-041-042.
WINTER WEATHER ADVISORY FROM 10 PM MST /11 PM CST/ WEDNESDAY TO
6 AM MST /7 AM CST/ THURSDAY FOR KSZ003-004-014>016-028-029-
041-042.
CO...RED FLAG WARNING UNTIL 6 PM MST THIS EVENING FOR COZ252>254.
WINTER WEATHER ADVISORY FROM 7 PM WEDNESDAY TO 6 AM MST THURSDAY
FOR COZ090>092.
WIND ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ090>092.
NE...RED FLAG WARNING UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
NEZ079>081.
WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ WEDNESDAY TO 6
AM MST /7 AM CST/ THURSDAY FOR NEZ079>081.
WIND ADVISORY UNTIL 6 PM MST /7 PM CST/ THIS EVENING FOR
NEZ079>081.
&&
$$
SHORT TERM...DJR
LONG TERM...BULLER
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
333 AM MST MON FEB 17 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 314 AM MST MON FEB 17 2014
SHORT TERM FORECAST CONCERN IS THE POSSIBILITY OF PRECIPITATION
LATE WEDNESDAY AND WEDNESDAY NIGHT.
BREEZY NORTHWEST WINDS EARLY TODAY WILL WEAKEN THROUGH THE DAY AND
TURN BACK TO THE SOUTHWEST AS A SURFACE TROUGH DEEPENS ALONG THE
FRONT RANGE AND WESTERLY WINDS CONTINUE ALOFT. A WEAK TROUGH
ALOFT MOVES ACROSS THE FORECAST AREA ON TUESDAY WITH A TROUGH
REFLECTED AT THE SURFACE THAT WILL AGAIN SEE SOUTHWEST WINDS
TURNING TO THE NORTHWEST AND BECOMING GUSTY DURING THE AFTERNOON.
THERE WILL BE WEAK RIDGING A LOFT AHEAD OF THE NEXT TROUGH
EXPECTED TO MOVE EAST OF THE ROCKIES WEDNESDAY NIGHT ALONG WITH A
COLD FRONT THAT PUSHES THROUGH THE FORECAST AREA WEDNESDAY
EVENING. ALONG AND BEHIND THE FRONT THERE IS A BAND OF
PRECIPITATION THAT IS CONSISTENTLY SHOWING UP IN MODEL SOLUTIONS.
THIS PRECIPITATION IS EXPECTED TO START OUT AS RAIN WEDNESDAY
EVENING AND TRANSITION TO ALL SNOW AFTER MIDNIGHT WITH ONE INCH OR
LESS OF TOTAL SNOW ACCUMULATIONS.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 314 AM MST MON FEB 17 2014
UPPER LEVEL TROUGH WILL MOVE EASTWARD AS AN UPPER LEVEL SHORTWAVE
TROUGH MOVES INTO THE HIGH PLAINS FOR THURSDAY. CENTRAL TROUGH AXIS
LOOKS TO BE SOMEWHERE BETWEEN THE COLORADO FRONT RANGE AND OUR
FORECAST AREA. STRONGEST JET AND VORT MAXES SHOULD REMAIN SOUTH OF
THE TRI STATE AREA. A WEAK SHORTWAVE RIDGE WILL THEN MOVE INTO THE
FORECAST AREA THURSDAY BEFORE DISSIPATING THURSDAY NIGHT. ANOTHER
PUSH OF COLD AIR ALOFT WILL MOVE INTO THE REGION FRIDAY AS AN UPPER
LEVEL TROUGH WILL PERSIST OVER THE AREA NEXT WEEKEND.
SURFACE COLD FRONT SHOULD BE WELL THROUGH THE FORECAST AREA BY
THURSDAY MORNING...HOWEVER SOME LINGERING LIGHT SNOW SHOWERS WILL BE
POSSIBLE BEHIND THE FRONT. NO SIGNIFICANT SNOW ACCUMULATIONS WITH
THIS SYSTEM ARE EXPECTED AT THIS TIME. THE REGION WILL RECEIVE A
BRIEF BREAK IN WEATHER THURSDAY AFTERNOON AND EVENING AS A SMALL
AREA OF SURFACE HIGH PRESSURE SLIDES INTO THE HIGH PLAINS.
ANOTHER COLD FRONTAL PASSAGE WILL AFFECT THE AREA FRIDAY
AFTERNOON...WHICH WILL BRING CHANCES FOR SOME WIDESPREAD LIGHT SNOW
SHOWERS OVERNIGHT INTO SATURDAY MORNING. HIGH TEMPERATURES WILL DIP
SLIGHTLY BELOW AVERAGE INTO THE UPPER 30S. WARMER AIR WILL APPROACH
FROM THE SOUTH SUNDAY...BUT THE WARM FRONT DOES NOT LOOK TO PASS
THROUGH THE AREA. HIGH TEMPERATURES WILL RETURN TO APPROXIMATELY
NORMAL CONDITIONS IN THE MID 40S.
THE SLOW MOVING BOUNDARY LOOKS TO SET UP THROUGH WEST CENTRAL
KANSAS...WHICH MAY CAUSE SOME LIGHT PRECIPITATION ACROSS THE AREA MONDAY.
1000-500 MB THICKNESS INDICATES THAT THE FORECAST AREA WILL BE
SPLIT...WITH CHANCES FOR LIGHT RAIN SHOWERS IN THE SOUTHERN HALF AND
CHANCES FOR LIGHT SNOW SHOWERS IN THE NORTHERN HALF. HIGH
TEMPERATURES SHOULD STAY IN THE LOW TO MID 40S. GUIDANCE SUGGESTS
THE WARM FRONT WILL MAKE A FINAL PUSH THROUGH THE REGION BY MONDAY
LATE AFTERNOON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 928 PM MST SUN FEB 16 2014
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. THE COLD
FRONT HAS ALREADY MOVED THROUGH KGLD AND WINDS HAVE SHIFTED TO THE NORTHWEST...A
LITTLE EARLIER THAN PREVIOUSLY THOUGHT. THE COLD FRONT WILL HAVE
MOVED THROUGH KMCK BEFORE 06Z WITH NORTHWEST WINDS AROUND 15 KTS
AFTER BRIEFLY HIGHER WIND SPEEDS AND GUSTS. BASED ON OBSERVATIONS AT
KGLD AND UPSTREAM...DID NOT INCLUDE GUSTS IN FOR THE INITIAL
PREVAILING GROUP AT EITHER TERMINAL. HOWEVER...BUFKIT RAP SOUNDINGS STILL
INDICATE WINDS INCREASING OVERNIGHT WITH GUSTS AROUND 30 TO 35
KTS BETWEEN 06Z AND 12Z. SINCE THE RAP SEEMS TO BE CATCHING THE
CURRENT CONDITIONS AND UPSTREAM SITES HAVE GUSTS AROUND 35 KTS...DECIDED
TO GO WITH THIS FOR NOW. TOMORROW AFTERNOON WINDS WILL SHIFT AGAIN
TO THE WEST- SOUTHWEST...WITH GUSTS AROUND 20 TO 25 KTS. WINDS
SHOULD DIMINISH AROUND SUNSET...REMAINING SUSTAINED AROUND OR
UNDER 10 KTS WITH NO GUSTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...LOCKHART
LONG TERM...99
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
937 PM MST SUN FEB 16 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 151 PM MST SUN FEB 16 2014
CONCERNS THROUGH TOMORROW WILL BE WINDS TONIGHT AND FIRE WEATHER
ISSUES MONDAY. COLD FRONT WILL MOVE THROUGH THE AREA DURING THE
LATE EVENING AND OVERNIGHT HOURS. TIGHTENING PRESSURE GRADIENT AND
3 HOUR PRESSURE RISES BEHIND THE FRONT INDICATE THAT WINDS WILL BE
NEAR WIND ADVISORY CRITERIA. MODELS INDICATE THAT WINDS AT 850 MB
WILL BE IN THE 40 TO 50 KNOT RANGE. PROBLEM IS THAT LOW LEVEL
LAPSE RATES ARE POOR DUE TO DECOUPLING FROM THE SURFACE. SOUNDINGS
SHOW THE LOW LEVEL INVERSION REMAINING INTACT. ALSO STRONGEST
DOWNWARD MOTION OCCURS AFTER THE STRONGEST LOW LEVEL WINDS HAVE
MOVED OFF TO THE EAST.
ALSO SINCE DO NOT THINK THERE WILL BE ANY PRECIPITATION AROUND...THE
HIGHER WINDS SHOULD NOT BE MIXED DOWN TO THE GROUND. SO DO NOT PLAN
ON ISSUING A WIND ADVISORY BUT WOULD NOT BE SURPRISED THAT WE COULD
SEE GUSTS TO NEAR 45 MPH RIGHT AFTER THE FRONTAL PASSAGE. NOT A
LOT OF COLD AIR BEHIND THIS FRONT. THAT COMBINED WITH A STRONG
DOWNSLOPE COMPONENT TO THE WINDS SLOWING DOWN THE COOLING...LOW
TEMPERATURES SHOULD STAY RATHER MILD AND MAY STAY ABOVE FREEZING
IN SOME LOCATIONS.
SHOULD SEE PLENTY OF SUN ON MONDAY. SURFACE RIDGE WILL MOVE TO THE
SOUTH OF THE AREA BY LATE MORNING WITH A NEW LEE TROUGH DEVELOPING
TO OUR WEST. WINDS WILL SHIFT FROM WEST TO NORTHWEST IN THE MORNING TO
SOUTH AND SOUTHWEST IN THE AFTERNOON. MODELS DO NOT COMPLETELY GET
RID OF LOW LEVEL INVERSION. HOWEVER WITH ONLY WEAK COOLING AND
DOWNSLOPE COMPONENT TO THE WIND...TEMPERATURES MAY END UP BEING
WARMER THAN TODAYS MAXES. DID RAISE MAXES A LITTLE BASED ON THE
DRY AIR MASS...850 MB TEMPERATURES...AND A BLEND OF THE BETTER
PERFORMING GUIDANCE FROM THE LAST FEW DAYS. REFER TO THE FIRE
WEATHER SECTION FOR HOW THIS ALL AFFECTS FIRE WEATHER ISSUES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 146 PM MST SUN FEB 16 2014
THE WARM DRY PATTERN WILL CONTINUE THROUGH WEDNESDAY AS A DRY
ENVIRONMENT WILL PERSIST OVER THE AREA. A SURFACE TROUGH OF LOW
PRESSURE WILL MOVE THROUGH THE AREA LATE MONDAY NIGHT THROUGH EARLY
TUESDAY MORNING. BEHIND THE TROUGH WINDS WILL BECOME BREEZY EAST OF
THE COLORADO BORDER TUESDAY AFTERNOON. WEDNESDAY A SHORT WAVE RIDGE
WILL BUILD OVER THE AREA. WEDNESDAY NIGHT AN UPPER LEVEL TROUGH AND
ASSOCIATED COLD FRONT WILL MOVE THROUGH THE AREA. THE ENVIRONMENT
CONTINUES TO LOOK UNFAVORABLE FOR PRECIP. DEVELOPMENT AS THE MAIN
UPPER LEVEL LOW OVER THE NORTHERN PLAINS BRINGS A DRY SLOT OVER THE
TRI-STATE AREA AHEAD OF THE TROUGH. WITH THE ADDED LIFT OF THE
FRONTAL PASSAGE THERE MAY BE ENOUGH LIFT TO GENERATE SOME PRECIP.
FROM THE SHALLOW SATURATED LAYER.
DRY CONDITIONS AND SLIGHTLY COOLER TEMPERATURES MOVE OVER THE AREA
THURSDAY INTO FRIDAY AS ZONAL FLOW FOLLOWS THE TROUGH FROM WEDNESDAY
NIGHT.
FRIDAY NIGHT ANOTHER UPPER LEVEL TROUGH WILL MOVE ACROSS THE AREA
BRINGING A STRONGER COLD FRONT WITH IT. MODELS HAVE FLATTENED THE
TROUGH OUT CONSIDERABLY FROM YESTERDAY WHICH IN TURN HAS SHOVED THE
DEEPER MOISTURE FURTHER NORTHEAST. AS A RESULT PRECIP. CHANCES HAVE
DROPPED...WITH DRY CONDITIONS FORECAST FOR MUCH OF THE AREA FOR
FRIDAY NIGHT THROUGH SATURDAY NIGHT. TEMPERATURES BEHIND THE FRONT
WILL BE 10 TO 15 DEGREES BELOW NORMAL.
SUNDAY A WARM FRONT MOVES THROUGH THE AREA BRINGING TEMPERATURES
BACK TO NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 928 PM MST SUN FEB 16 2014
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. THE COLD
FRONT HAS ALREADY MOVED THROUGH KGLD AND WINDS HAVE SHIFTED TO THE NORTHWEST...A
LITTLE EARLIER THAN PREVIOUSLY THOUGHT. THE COLD FRONT WILL HAVE
MOVED THROUGH KMCK BEFORE 06Z WITH NORTHWEST WINDS AROUND 15 KTS
AFTER BRIEFLY HIGHER WIND SPEEDS AND GUSTS. BASED ON OBSERVATIONS AT
KGLD AND UPSTREAM...DID NOT INCLUDE GUSTS IN FOR THE INITIAL
PREVAILING GROUP AT EITHER TERMINAL. HOWEVER...BUFKIT RAP SOUNDINGS STILL
INDICATE WINDS INCREASING OVERNIGHT WITH GUSTS AROUND 30 TO 35
KTS BETWEEN 06Z AND 12Z. SINCE THE RAP SEEMS TO BE CATCHING THE
CURRENT CONDITIONS AND UPSTREAM SITES HAVE GUSTS AROUND 35 KTS...DECIDED
TO GO WITH THIS FOR NOW. TOMORROW AFTERNOON WINDS WILL SHIFT AGAIN
TO THE WEST- SOUTHWEST...WITH GUSTS AROUND 20 TO 25 KTS. WINDS
SHOULD DIMINISH AROUND SUNSET...REMAINING SUSTAINED AROUND OR
UNDER 10 KTS WITH NO GUSTS.
&&
.FIRE WEATHER...
ISSUED AT 151 PM MST SUN FEB 16 2014
MUCH OF THE AREA WILL SEE RELATIVE HUMIDITIES OF 20 PERCENT OR SLIGHTLY
LESS. QUESTION WILL BE THE WINDS. BELIEVE MODELS ARE OVERDOING WINDS
FOR THE FOLLOWING REASONS. SURFACE RIDGE WILL HAVE NOT MOVED AWAY TOO
FAR PLUS CROSS MOUNTAIN COMPONENT IS NOT THE GREATEST TO ALLOW A QUICK
AND STRONG DEVELOPMENT OF A LEE TROUGH. ALSO THERE IS LITTLE TO NO
DOWNWARD MOTION. IN FACT ANOTHER SHORTWAVE TROUGH WILL BE MOVING THROUGH.
LOW LEVEL LAPSE RATES ARE NOT VERY GOOD AND THAT COMBINED WITH THE
LACK OF DOWNWARD MOTION...MAKES ME THINK THAT MODELS ARE OVERDOING
THE MIXING.
HAD CONSIDERED A FIRE WEATHER WATCH FOR THE SOUTHWEST PORTION WHERE
THE BEST COMBINATION OF WINDS AND RELATIVE HUMIDITIES WERE. HOWEVER
AS SPECIFIED ABOVE...BELIEVE WILL NOT HAVE STRONG ENOUGH WINDS AND
DO NOT BELIEVE RED FLAG CONDITIONS WILL BE MET FOR THREE HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JTL
AVIATION...ALW
FIRE WEATHER...BULLER
AREA FORECAST DISCUSSION
NWS PADUCAH KY
910 PM CST Tue Feb 18 2014
.UPDATE...
ISSUED AT 910 PM CST TUE FEB 18 2014
Latest mesoscale models indicate showers will develop over western
KY and possibly southwest Indiana through about 06z. This looks
reasonable as surface dew points in the mid to upper 50s are already
entering the Missouri Bootheel and northwest Tennessee. This
moisture is arriving immediately ahead of a cold front that was
crossing central Missouri this evening. The front is expected to
cross the Lower Ohio Valley around 09z and the khop area around 12z.
Some thunder cannot be ruled out as weak elevated instability
develops tonight. RAP model mucapes range up to 800 j/kg overnight.
Raised and expanded pops over western Kentucky to as high as 50
percent in the khop area. The precip should cut off quickly by 12z
as deep layer westerly flow brings drier air.
.SHORT TERM...(This Evening through Thursday Night)
ISSUED AT 109 PM CST TUE FEB 18 2014
In the near term, there is warm advection ongoing, with winds
gusting to/near the 20s mph at times. Deeper moisture is pooled
across the lower MS valley, with 30s surface TD`s here, and 50s-
60s there. 40s is just barely to our south. This bulk area will
advect north and affect mainly our southern tier counties tonight,
as a cold front comes together basically on top of us upon its
evolution eastward from the Plains tonight. We have retained a
small chance of rain in our south and east for this system`s
passage. The new swody1 actually paints WKY in the area of
possible thunder, but with the GFS showing K and Showalter indices
that support its mention staying just to our south and east, we`ll
refrain from actually including thunder mention for our CWA. It
will be something to keep a close eye upon, however.
After this system passage tonight, surface high pressure migrates
west to east overhead Wednesday. This will provide a nice tranquil
day before things get changing and dicey for the big Thursday
system. Actually, a low level jet establishes itself Wed night,
and elevated instability indices support thunder mention then, as
we warm sector. Cannot rule out isolated stronger elevated storm
with cooler temps aloft still residing, but better action comes
together during the day Thursday.
After a brief warm sector lull Thursday morning, the surface low
deepens and races across Missouri, still looking to be around the
IA/IL/MO border area by 18Z. Its trailing cold front approaches
our western reaches of the FA at this time, and sweeps across the
bulk of the FA thru 00Z Fri, as the Low further deepens/winds up
across the Great Lakes. 300 mb jet actually enhances during this
time, and impressive shear is deepening throughout the layer,
making for an increasing damaging wind hazard expectation with
surface based storms. PM instability parameters support convection
going surface based, esp east of the MS river. SLGT risk severe
currently resides in swody3, with 30% Combined outlook suggesting
an upgrade possible into the day2 outlook tmrw, all things being
equal or improving.
Whether taking the fast model (NAM), in between model (GFS), or
slower model (ECMWF) on fropa, nearly all convection departs by
06Z Friday. Svr threat is most likely Thu pm/early evening.
In addition to the svr/wind threat, the warm temps (50s/60s and a
possible 70 Thursday) will melt any remaining snow/ice and result
in wet ground conditions. Areal average qpf of 1/2"-1" west to
east across the FA may result in flooding issues, esp if in
thunderstorms with heavy rain, localized flooding may occur. All
of the aforementioned is mentioned on the HWO.
.LONG TERM...(Friday through Tuesday)
ISSUED AT 253 PM CST TUE FEB 18 2014
High pressure over the southeast U.S. will keep our region dry
Friday into Friday night, and south winds will keep temperatures a
little above seasonal normals. For Saturday into Saturday night,
models indicate a weak cold front moving across the region, though
timing is quite variable. GFS keeps any precip north of the PAH
forecast area Saturday, ECMWF generates some light QPF across the
FA on Saturday, while the GEM holds off mainly until Saturday
night. With relative humidity time heights showing minimal
moisture to work with, for now just included some slight chance
pops across our northern counties Saturday night for rain and
snow.
Conditions will cool back down to a little below normal for Sunday
into Monday night behind the front. By Monday night into Tuesday,
ECMWF is faster with a cold front moving through the middle
Mississippi and lower Ohio valleys. ECMWF generates some decent
QPF mainly Monday night, while GFS shows light amounts and holds
off more until Tuesday for mainly our northern counties. Went
with low chance pops northwest to slight chance pops central to
southeast Monday night, with some lingering slight chance pops in
our eastern counties on Tuesday. Prefer to keep pops low until
we see some timing continuity, but in any case QPF amounts are not
too significant. Based on temps, precip would be a rain/snow mix
south to just light snow/flurries north.
&&
.AVIATION...
ISSUED AT 450 PM CST TUE FEB 18 2014
Will be monitoring for the possibility of isold convection through
the early evening, mainly east of the MS River. Otherwise band of
high clouds will move east, but lower deck 3-5k/ft should affect the
area part of the time, mainly through 06z. After that, skies should
clear with a front moving through. Weak high pressure will move
across the area Wednesday with light winds the rule. Considerable
high clouds expected.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
953 PM EST TUE FEB 18 2014
.SYNOPSIS...
LOW PRESSURE DEEPENS OFF THE NEW ENGLAND COAST AND WILL EXIT INTO
THE CANADIAN MARITIMES OVERNIGHT. A COLD FRONT WILL SWING IN FROM THE WEST
ON WEDNESDAY AND LOW PRESSURE WILL DEVELOP ON THE FRONT AS IT
PUSHES INTO THE GULF OF MAINE WEDNESDAY EVENING. LOW PRESSURE WILL
QUICKLY SHIFT EAST INTO THE MARITIMES WEDNESDAY NIGHT. HIGH
PRESSURE BUILD SIN FROM THE WEST ON THURSDAY. A WARM FRONT WILL
LIFT NORTH INTO THE REGION THURSDAY NIGHT AND IS QUICKLY FOLLOWED
BY A COLD FRONT FRIDAY. HIGH PRESSURE BUILDS SOUTH OF NEW ENGLAND
FRIDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
950 PM...A 1008 MILLIBAR LOW WAS JUST WEST OF THE 44005 BUOY IN
THE GULF OF MAINE AT 02Z. SNOW CONTINUES TO WIND DOWN FROM
SOUTHWEST TO NORTHEAST AND WINTER HEADLINES HAVE BEEN DROPPED FOR
SOUTHWEST MAINE WITH THIS ESTF UPDATE.
PREV DISC...
650 PM...SOME SLIGHT ADJUSTMENTS TO SNOW AMOUNTS FOR THE FINAL
UPDATE BEFORE WE BEGIN TAKING WINTER WEATHER HEADLINES DOWN.
EXPECT WE`LL BE DROPPING HEADLINES WITHIN THE NEXT FEW HOURS AS
THE BACK EDGE OF THE HEAVY SNOW BANDS RACE NORTHEAST OUT OF THE
FORECAST AREA.
458 PM...BANDS OF HEAVY SNOW ARE RACING NORTH AND EAST ACROSS THE
FORECAST AREA. SNOWFALL RATES HAVE APPROACHED 3 INCHES PER HOUR
IN THE HEAVIEST BANDS. I`VE ADJUSTED AMOUNTS UP A BIT FOR THIS
UPDATE AND EXPANDED THE WARNING TO INCLUDE SEACOAST NEW HAMPSHIRE.
PREV DISC...
LOW PRES IS RAPIDLY DEVELOPING AS EXPECTED OVER SRN NEW ENGLAND
COAST ATTM. BASED ON RADAR AND SFC OBSERVATIONS...IT WOULD SEEM AS
IF LOW PRES WILL TRACK JUST N OF KPYM AND INTO THE GULF OF ME.
HEAVY SNFL HAS WORKED INTO SRN NH AND ADJACENT SWRN ME...WITH
RATES APPROACHING 1 TO 3 INCHES PER HOUR. SNFL TOTALS ARE ALREADY
PUSHING 4 TO 6 OR MORE ACROSS PARTS OF INTERIOR ROCKINGHAM COUNTY.
BASED ON MODEL PROGS AND REPORTS...FEEL THAT THIS IS THE AREA NOW
IN LINE FOR HIGHEST AMOUNTS IN THE CWFA. HAVE INCREASED QPF AND
SNFL FORECAST FOR THIS AREA. FOR THE REST OF THE AREA USED A BLEND
OF THE ECMWF...NAM12...RAP...AND NERFC QPF. THIS SHIFTED THE
HEAVIEST SN A LITTLE EWD FROM PREVIOUS FORECAST. SNFL AMOUNTS
STILL MATCHED HEADLINES WELL...SO THEY WILL REMAIN AS IS.
ELY WINDS HAVE ALSO WARMED THE IMMEDIATE COAST AOA FREEZING.
DESPITE THE WARM TEMPS...DEW POINT DEPRESSIONS WILL ALLOW WET BULB
COOLING TO KEEP PCPN MOSTLY SN. HOWEVER...IT MAY BE WETTER IN
NATURE AND CLING TO POWER LINES/TREES LEADING TO SCT POWER
OUTAGES. ELY WINDS ARE ALSO DOWNSLOPING ON THE N SIDE OF THE
WHITES...DRYING OUT THE COLUMN. SN WILL LIKELY STRUGGLE TO REACH
THE GROUND AT TIMES IN THE FAR N.
AS FOR SRN NH INTO SWRN ME...HEAVY SNFL REMAINS IN THE FORECAST
INTO THE EVENING. RAP CONTINUES TO SHOW FORECAST SOUNDINGS FROM
KCON TO NEAR KPWM APPROACHING A MAUL...MOIST ABSOLUTELY UNSTABLE
LAYER. MODEL GUIDANCE HAS AN AREA OF 6 TO 7 DEG/KM LAPSE RATES
ALOFT WORKING INTO THE REGION THRU THE EVENING. THIS KIND OF
INSTABILITY WOULD BE FAVORABLE FOR CONVECTION IN THE WARM
SEASON...LET ALONE FEBRUARY. THERE HAVE BEEN NO RECENT REPORTS OF
LIGHTNING...BUT WOULD NOT BE SURPRISED TO SEE A FEW IN THE NEXT
COUPLE OF HOURS. CONSIDERING THE SNFL OCCURRING ATTM IN SERN
NH...SEE NO REASON WHY THIS TREND WON/T THEN CONTINUE FOR THE NEXT
SEVERAL HOURS INTO SWRN ME. THIS IS ALL ONGOING AS MID LEVEL LOW
CENTER QUICKLY SPIN UP...MAXIMIZING DYNAMICS. AS THESE MATURE THIS
EVENING...SN WILL GRADUALLY TAPER TO MORE MODEST RATES. AS FORCING
SHIFTS EWD...SN WILL RAPIDLY END FROM S TO N AROUND MIDNIGHT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS SOON AS TONIGHT`S STORM LIFTS INTO THE CANADIAN MARITIMES...
ANOTHER SHORT WAVE QUICKLY FOLLOWS ON ITS HEELS...FOLLOWING A
SIMILAR PATH. SURFACE LOW PRESSURE DEEPENS OVER THE GULF OF MAINE
WEDNESDAY AFTERNOON INTO THURSDAY MORNING. THIS STORM IS FORMING A
LITTLE TOO FAR OFFSHORE TO ACCOUNT FOR MORE THAN 1-3 INCHES AS IT
MOVES QUICKLY BY.
TEMPERATURES WILL BE IN THE MID 30S TO MID 40S WEDNESDAY THROUGH
FRIDAY AS WARM AIR ADVECTION IS REINFORCED EVERY 18 HRS OR SO.
THE TIMING OF THESE WAVES AS WELL AS NEAR ZONAL FLOW ALOFT WILL
KEEP ANY COLD AIR FROM TAKING HOLD FOR MOST OF THE WEEK.
HOWEVER...SOME COLDER AIR DOES MANAGE TO SNEAK IN BEHIND A COLD
FRONT ON FRIDAY. THIS WILL BE PRECEDED BY A WARM FRONT FRIDAY
MORNING. TEMPERATURES AT THE ONSET OF THIS PRECIPITATION EVENT
SUPPORTS A LARGE SWATH OF FREEZING RAIN AND POSSIBLY SOME SLEET
FRIDAY MORNING AS WARMER AIR OVERRIDES FREEZING TEMPERATURES
NEAR THE SURFACE. AT THIS TIME IT LOOKS TO BE A COUPLE TENTHS OF
AN INCH OF ICE ACCUMULATION...BUT IT WILL OCCUR DURING MORNING RUSH
HOUR. AS WARMER AIR IS DRAGGED DOWN WE WILL TRANSITION TO A MOSTLY
RAIN EVENT DURING THE DAY WITH A LITTLE WRAP AROUND SNOW ONCE THE
COLD FRONT MOVES THROUGH. THIS SYSTEM HAS MUCH MORE MOISTURE TO
WORK WITH THAN WE HAVE HAD LATELY...AND THIS WILL RESULT IN PLENTY
OF SNOW MELT AND POSSIBLY ICE JAM ISSUES.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM.../THROUGH WEDNESDAY MORNING/...WIDESPREAD IFR AND LIFR
EXPECTED S OF THE FOOTHILLS THRU THIS EVENING. N OF THE MTNS IFR
CONDITIONS WILL BE MORE VARIABLE AS DOWNSLOPING DRIES OUT THE AIR
MASS. CONDITIONS WILL QUICKLY IMPROVE FROM S TO N AFTER MIDNIGHT.
LONG TERM...ADDITIONAL SNOW IS FORECAST FOR WEDNESDAY AFTERNOON
INTO THURSDAY MORNING...AND WILL PRODUCE LIFR CEILINGS AND
VISIBILITIES. WIDESPREAD MIXED PRECIPITATION INCLUDING FREEZING
RAIN AND RAIN WILL CREATE POOR FLYING CONDITIONS THURSDAY NIGHT
INTO FRIDAY.
&&
.MARINE...
SHORT TERM...GALES REMAIN UP FOR THE OUTER WATERS...WITH SCA
CONDITIONS EXPECTED IN THE BAYS. WINDS AND SEAS GRADUALLY SUBSIDE
INTO WED MORNING.
LONG TERM...SMALL CRAFT ADVISORIES MAY BE NEEDED AT TIMES THROUGH
FRIDAY WITH GUSTS AROUND 25-30 KTS AND WAVES IN THE 4-6 FT
RANGE...MAINLY OUTSIDE THE BAYS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 4 AM EST WEDNESDAY FOR
MEZ012>014-021-022-027-028.
WINTER STORM WARNING UNTIL 4 AM EST WEDNESDAY FOR MEZ020-025-
026.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST WEDNESDAY FOR ANZ151-153.
GALE WARNING UNTIL 4 AM EST WEDNESDAY FOR ANZ150-152-154.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS GRAY ME
656 PM EST TUE FEB 18 2014
.SYNOPSIS...
LOW PRESSURE DEEPENS OFF THE NEW ENGLAND COAST AND MOVE OVER THE
GULF OF MAINE TONIGHT BEFORE MOVING INTO THE CANADIAN MARITIMES.
A COLD FRONT WILL SWING IN FROM THE WEST ON WEDNESDAY AND LOW
PRESSURE WILL DEVELOP ON THE FRONT AS IT PUSHES INTO THE GULF OF
MAINE WEDNESDAY EVENING. LOW PRESSURE WILL QUICKLY SHIFT EAST INTO
THE MARITIMES WEDNESDAY NIGHT. HIGH PRESSURE BUILD SIN FROM
THE WEST ON THURSDAY. A WARM FRONT WILL LIFT NORTH INTO THE REGION
THURSDAY NIGHT AND IS QUICKLY FOLLOWED BY A COLD FRONT FRIDAY.
HIGH PRESSURE BUILDS SOUTH OF NEW ENGLAND FRIDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
650 PM...SOME SLIGHT ADJUSTMENTS TO SNOW AMOUNTS FOR THE FINAL
UPDATE BEFORE WE BEGIN TAKING WINTER WEATHER HEADLINES DOWN.
EXPECT WE`LL BE DROPPING HEADLINES WITHIN THE NEXT FEW HOURS AS
THE BACK EDGE OF THE HEAVY SNOW BANDS RACE NORTHEAST OUT OF THE
FORECAST AREA.
458 PM...BANDS OF HEAVY SNOW ARE RACING NORTH AND EAST ACROSS THE
FORECAST AREA. SNOWFALL RATES HAVE APPROACHED 3 INCHES PER HOUR
IN THE HEAVIEST BANDS. I`VE ADJUSTED AMOUNTS UP A BIT FOR THIS
UPDATE AND EXPANDED THE WARNING TO INCLUDE SEACOAST NEW HAMPSHIRE.
PREV DISC...
LOW PRES IS RAPIDLY DEVELOPING AS EXPECTED OVER SRN NEW ENGLAND
COAST ATTM. BASED ON RADAR AND SFC OBSERVATIONS...IT WOULD SEEM AS
IF LOW PRES WILL TRACK JUST N OF KPYM AND INTO THE GULF OF ME.
HEAVY SNFL HAS WORKED INTO SRN NH AND ADJACENT SWRN ME...WITH
RATES APPROACHING 1 TO 3 INCHES PER HOUR. SNFL TOTALS ARE ALREADY
PUSHING 4 TO 6 OR MORE ACROSS PARTS OF INTERIOR ROCKINGHAM COUNTY.
BASED ON MODEL PROGS AND REPORTS...FEEL THAT THIS IS THE AREA NOW
IN LINE FOR HIGHEST AMOUNTS IN THE CWFA. HAVE INCREASED QPF AND
SNFL FORECAST FOR THIS AREA. FOR THE REST OF THE AREA USED A BLEND
OF THE ECMWF...NAM12...RAP...AND NERFC QPF. THIS SHIFTED THE
HEAVIEST SN A LITTLE EWD FROM PREVIOUS FORECAST. SNFL AMOUNTS
STILL MATCHED HEADLINES WELL...SO THEY WILL REMAIN AS IS.
ELY WINDS HAVE ALSO WARMED THE IMMEDIATE COAST AOA FREEZING.
DESPITE THE WARM TEMPS...DEW POINT DEPRESSIONS WILL ALLOW WET BULB
COOLING TO KEEP PCPN MOSTLY SN. HOWEVER...IT MAY BE WETTER IN
NATURE AND CLING TO POWER LINES/TREES LEADING TO SCT POWER
OUTAGES. ELY WINDS ARE ALSO DOWNSLOPING ON THE N SIDE OF THE
WHITES...DRYING OUT THE COLUMN. SN WILL LIKELY STRUGGLE TO REACH
THE GROUND AT TIMES IN THE FAR N.
AS FOR SRN NH INTO SWRN ME...HEAVY SNFL REMAINS IN THE FORECAST
INTO THE EVENING. RAP CONTINUES TO SHOW FORECAST SOUNDINGS FROM
KCON TO NEAR KPWM APPROACHING A MAUL...MOIST ABSOLUTELY UNSTABLE
LAYER. MODEL GUIDANCE HAS AN AREA OF 6 TO 7 DEG/KM LAPSE RATES
ALOFT WORKING INTO THE REGION THRU THE EVENING. THIS KIND OF
INSTABILITY WOULD BE FAVORABLE FOR CONVECTION IN THE WARM
SEASON...LET ALONE FEBRUARY. THERE HAVE BEEN NO RECENT REPORTS OF
LIGHTNING...BUT WOULD NOT BE SURPRISED TO SEE A FEW IN THE NEXT
COUPLE OF HOURS. CONSIDERING THE SNFL OCCURRING ATTM IN SERN
NH...SEE NO REASON WHY THIS TREND WON/T THEN CONTINUE FOR THE NEXT
SEVERAL HOURS INTO SWRN ME. THIS IS ALL ONGOING AS MID LEVEL LOW
CENTER QUICKLY SPIN UP...MAXIMIZING DYNAMICS. AS THESE MATURE THIS
EVENING...SN WILL GRADUALLY TAPER TO MORE MODEST RATES. AS FORCING
SHIFTS EWD...SN WILL RAPIDLY END FROM S TO N AROUND MIDNIGHT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS SOON AS TONIGHT`S STORM LIFTS INTO THE CANADIAN MARITIMES...
ANOTHER SHORT WAVE QUICKLY FOLLOWS ON ITS HEELS...FOLLOWING A
SIMILAR PATH. SURFACE LOW PRESSURE DEEPENS OVER THE GULF OF MAINE
WEDNESDAY AFTERNOON INTO THURSDAY MORNING. THIS STORM IS FORMING A
LITTLE TOO FAR OFFSHORE TO ACCOUNT FOR MORE THAN 1-3 INCHES AS IT
MOVES QUICKLY BY.
TEMPERATURES WILL BE IN THE MID 30S TO MID 40S WEDNESDAY THROUGH
FRIDAY AS WARM AIR ADVECTION IS REINFORCED EVERY 18 HRS OR SO.
THE TIMING OF THESE WAVES AS WELL AS NEAR ZONAL FLOW ALOFT WILL
KEEP ANY COLD AIR FROM TAKING HOLD FOR MOST OF THE WEEK.
HOWEVER...SOME COLDER AIR DOES MANAGE TO SNEAK IN BEHIND A COLD
FRONT ON FRIDAY. THIS WILL BE PRECEDED BY A WARM FRONT FRIDAY
MORNING. TEMPERATURES AT THE ONSET OF THIS PRECIPITATION EVENT
SUPPORTS A LARGE SWATH OF FREEZING RAIN AND POSSIBLY SOME SLEET
FRIDAY MORNING AS WARMER AIR OVERRIDES FREEZING TEMPERATURES
NEAR THE SURFACE. AT THIS TIME IT LOOKS TO BE A COUPLE TENTHS OF
AN INCH OF ICE ACCUMULATION...BUT IT WILL OCCUR DURING MORNING RUSH
HOUR. AS WARMER AIR IS DRAGGED DOWN WE WILL TRANSITION TO A MOSTLY
RAIN EVENT DURING THE DAY WITH A LITTLE WRAP AROUND SNOW ONCE THE
COLD FRONT MOVES THROUGH. THIS SYSTEM HAS MUCH MORE MOISTURE TO
WORK WITH THAN WE HAVE HAD LATELY...AND THIS WILL RESULT IN PLENTY
OF SNOW MELT AND POSSIBLY ICE JAM ISSUES.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM.../THROUGH WEDNESDAY MORNING/...WIDESPREAD IFR AND LIFR
EXPECTED S OF THE FOOTHILLS THRU THIS EVENING. N OF THE MTNS IFR
CONDITIONS WILL BE MORE VARIABLE AS DOWNSLOPING DRIES OUT THE AIR
MASS. CONDITIONS WILL QUICKLY IMPROVE FROM S TO N AFTER MIDNIGHT.
LONG TERM...ADDITIONAL SNOW IS FORECAST FOR WEDNESDAY AFTERNOON
INTO THURSDAY MORNING...AND WILL PRODUCE LIFR CEILINGS AND
VISIBILITIES. WIDESPREAD MIXED PRECIPITATION INCLUDING FREEZING
RAIN AND RAIN WILL CREATE POOR FLYING CONDITIONS THURSDAY NIGHT
INTO FRIDAY.
&&
.MARINE...
SHORT TERM...GALES REMAIN UP FOR THE OUTER WATERS...WITH SCA
CONDITIONS EXPECTED IN THE BAYS. WINDS AND SEAS GRADUALLY SUBSIDE
INTO WED MORNING.
LONG TERM...SMALL CRAFT ADVISORIES MAY BE NEEDED AT TIMES THROUGH
FRIDAY WITH GUSTS AROUND 25-30 KTS AND WAVES IN THE 4-6 FT
RANGE...MAINLY OUTSIDE THE BAYS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 4 AM EST WEDNESDAY FOR MEZ018>020-
023>026.
WINTER WEATHER ADVISORY UNTIL 4 AM EST WEDNESDAY FOR
MEZ012>014-021-022-027-028.
NH...WINTER STORM WARNING UNTIL 4 AM EST WEDNESDAY FOR NHZ006-009.
WINTER WEATHER ADVISORY UNTIL 1 AM EST WEDNESDAY FOR
NHZ002>005-007.
WINTER STORM WARNING UNTIL 1 AM EST WEDNESDAY FOR NHZ008-010-
013-014.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST WEDNESDAY FOR ANZ151-153.
GALE WARNING UNTIL 4 AM EST WEDNESDAY FOR ANZ150-152-154.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
637 PM EST TUE FEB 18 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 405 PM EST TUE FEB 18 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A LOW AMPLITUDE TROF
MOVING ACROSS THE NCNTRL STATES/UPPER MISSISSIPPI VALLEY. THERE ARE
SEVERAL VORT MAXES WITHIN THE TROF. AHEAD OF ONE SHORTWAVE OVER NRN
ONTARIO INTO MN...RADAR RETURNS HAVE BEEN SHOWING UP IN NE MN AND
NOW ACROSS LAKE SUPERIOR. GIVEN DRY LOW-LEVELS...PCPN HAS NOT BEEN
ABLE TO REACH THE GROUND.
AS AFOREMENTIONED SHORTWAVE MOVES ACROSS THE UPPER LAKES TONIGHT...
NOT OUT OF THE QUESTION THAT PATCHY -SN/FLURRIES OR -FZDZ COULD
DEVELOP OVER THE ERN FCST AREA WHERE SHALLOW LOW-LEVEL MOISTURE HAS
ADVECTED N OFF LAKE MICHIGAN. IF LAYER BTWN THE MID LEVEL MOISTURE
AND SHALLOW MOISTURE OFF THE LAKE DOES NOT MOISTEN SUFFICIENTLY...
THEN -FZDZ WILL BE THE PTYPE IF ANY PCPN DOES OCCUR. ELSEWHERE...
HAVE SOME CONCERN FOR -FZDZ OVER THE KEWEENAW WITH WINDS SHIFTING TO
AN UPSLOPE WESTERLY DIRECTION WITH SFC TROF PASSAGE. THERE IS AN
AXIS OF SLIGHTLY HIGHER DWPTS THAT WILL BE ADVECTED INTO THE HIGHER
TERRAIN...AND THIS COULD LEAD TO POSSIBLE STRATUS/FOG AND EVEN
-FZDZ. HOWEVER...WITH FCST SOUNDINGS SHOWING ONLY A VERY SHALLOW SFC
BASED MOIST LAYER AND SINCE MUCH OF WRN LAKE SUPERIOR IS ICED OVER
TO GREATLY LIMIT ANY ADDITIONAL MOISTENING FROM THE LAKE...-FZDZ
POTENTIAL SEEMS VERY MINIMAL ATTM. OUTSIDE OF THOSE CONCERNS...
TONIGHT WILL BE ONE OF THE WARMER NIGHTS IN QUITE A WHILE UNDER
PACIFIC AIR MASS. EXPECT MIN TEMPS GENERALLY IN THE MID TEENS TO
LOWER 20S.
WED WILL BE A DRY DAY AS MIDLEVEL TROF SHIFTS E OF THE AREA AND
SHORTWAVE RIDGING BUILDS INTO THE WRN LAKES. WHILE THERE MIGHT BE
SOME LOW CLOUDS LINGERING INTO WED MORNING OVER THE NW AND MORE
LIKELY THE NE FCST AREA...EXPECT MOST AREAS TO SEE A GOOD DISPLAY OF
SUNSHINE WED. HIGHER MID TO LATE FEB SUN ANGLE WORKING ON THE LOWER
ALBEDO FORESTED TERRAIN WILL HELP TEMPS RISE WELL INTO THE 30S AND
EVEN INTO THE LWR 40S ACROSS MUCH OF THE FCST AREA. NOT OUT OF THE
QUESTION FOR A FEW LOCATIONS TO REACH THE MID 40S WHERE DOWNSLOPING
OCCURS. WITH W TO WNW WINDS FOR MUCH OF THE DAY...TEMPS WILL BE
COOLEST NEAR LAKE SUPERIOR OVER WRN UPPER MI AND OVER THE NE FCST
AREA. IN THOSE LOCATIONS...TEMPS SHOULD STRUGGLE TO RISE ABOVE
FREEZING NEAR THE LAKE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 505 PM EST TUE FEB 18 2014
WED NIGHT...
HIGH PRES AND CLEAR TO PARTLY CLOUDY SKIES WILL GIVE WAY
TO INCREASING SRLY WINDS AND MID/HIGH CLOUDS AS THE WAA REGIME
STRENGTHENS AHEAD OF THE MID LEVEL TROUGH OVER THE PLAINS AND SFC
TROUGH MOVING INTO THE UPPER MS VALLEY. LOWS ARE ONLY EXPECTED TO
DROP INTO THE LOWER 20S.
THURSDAY INTO FRIDAY...
THE MODELS HAVE COME INTO RELATIVELY GOOD AGREEMENT WITH THE TRACK
OF THE INTENSIFYING LOW PRESSURE SYSTEM MOVING INTO THE WRN GREAT
LAKES AND THE STRENGTH/POSITION OF THE MID LEVEL FEATURES. THE WPC
FAVORED ECMWF/GEM REMAINED A BIT FARTHER WEST WITH THE TRACK
COMPARED TO THE GFS. SINCE THE 12Z NAM WAS ALSO VERY CLOSE TO THE
ECMWF...IT WAS USED FOR MORE OF THE FCST DETAILS. THE LOW IS
EXPECTED TO RAPIDLY DEEPEN AS IT TRACKS NORTH FROM NEAR MKE AT
00Z/FRI TO NEAR MARQUETTE AT 06Z/FRI AND INTO NRN LAKE SUPERIOR AT
12Z/FRI.
THE POTENT MID LEVEL DYNAMICS WITH STRONG 700-300 QVECTOR CONV AND
FGEN COMBINED WITH ABUNDANT MOISTURE INFLOW SHOULD EASILY BE ABLE TO
PRODUCE QPF AMOUNTS AROUND AN INCH...ESPECIALLY OVER THE WEST THIRD
OF THE CWA. WITH AN ELEVATED DGZ AOA 10K FT...SLR ONLY AROUND 12Z/1
ARE EXPECTED LEADING TO SNOWFALL AMOUNTS AOA 10 INCHES OVER THE WEST
AND AROUND 6 INCHES CENTRAL. MIXED PCPN IS ALSO EXPECTED OVER THE
EAST HALF WITH AN 850-700 MB WARM LAYER MOVING LATE THU INTO THU
EVENING. WITH SFC TEMPS NEAR FREEZING...A MIX OF SN/PL/FZRA BEFORE
THE PCPN CHANGES BACK TO SNOW LATE. THERE IS STILL MORE UNCERTAINTY
ABOUT THE SNOW AMOUNTS AND PCPN TYPE TIMING OVER THE EAST HALF GIVEN
LINGERING MODEL DIFFERENCES. AS THE LOW MOVES NORTH OF UPPER MI LATE
THU NIGHT INTO FRI MORNING...STRONG WEST WINDS ARE EXPECTED TO
DEVELOP. NAM BUFKIT MIXED LAYER WINDS IN THE 40-50 KT RANGE OVER THE
KEWEENAW SUGGEST POTENTIAL FOR VERY STRONG SFC WINDS WITH SEVERE
BLOWING AND DRIFTING SNOW. SO...A BLIZZARD WATCH WAS POSTED FOR THE
KEWEENAW. OTHER LOCATIONS ACROSS THE CWA WILL ALSO BLSN BUT WILL
HAVE FEWER IMPACTS WITH A WEST WIND. THE WINDS WILL ONLY GRADUALLY
DIMINISH FRIDAY AFTERNOON INTO EVENING. ALTHOUGH THE STRONG WINDS
MAY BREAK UP SOME OF THE LAKE ICE...THE REMAINING EXTENSIVE ICE
COVER WILL SIGNIFICANTLY REDUCE CHANCE FOR ADDITIONAL LAKE ENHANCED
SNOW OR LES. HOWEVER...THE UPSLOPE TERRAIN ENHANCEMENT COULD STILL
BOOST SNOWFALL AMOUNTS OVER THE HIGHER TERRAIN OF THE NW CWA.
SAT-TUE...
ONLY SMALL CHANCE POPS WERE INCLUDED NEAR LAKE SUPERIOR FOR WNW/W
FLOW AREAS AS TEMPS ARE SUFFICIENTLY COLD FOR LAKE EFFECT RIGHT
THROUGH THE WEEKEND. WITH THE EXTENSIVE ICE ON LAKE SUPERIOR IT WILL
BE BE INTERESTING TO SEE HOW MUCH OPEN WATER DEVELOPS AFTER THE
STRONG WINDS EXPECTED ON FRIDAY. AWAY FROM ANY LAKE EFFECT...THE
RETURNING COLD WILL BE THE MAIN STORY WITH READINGS BOTH SATURDAY AND
SUNDAY IN THE TEENS. THE COLD REGIME LOOKS TO AS THE WRN CONUS RIDGE
REEMERGES AND ARCTIC HIGH PRES BUILDS INTO THE REGION FROM WRN
CANADA. HOWEVER...THE MODELS WERE LESS AGGRESSIVE IN BRINGING THE
VERY COLD AIR COMPARED TO PREVIOUS RUNS. TEMPS WILL REMAIN WELL BELOW
NORMAL WITH HIGHS FROM 10 TO 15 AND LOWS FROM ZERO TO AT LEAST 5
BELOW. WIND CHILLS MON AND TUE MORNING ARE ALSO EXPECTED TO DROP TO
NEAR 20 BELOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 636 PM EST TUE FEB 18 2014
VFR CONDITIONS REPORTED AT ALL THREE TAF SITES EARLY THIS EVENING.
LOW END MVFR STRATUS LINGERS JUST TO THE EAST OF KSAW WITH
SOUTHERLY FLOW OFF OF LAKE MICHIGAN...HOWEVER WINDS AT KSAW CONTINUE
FROM THE SSW WHICH HAS LIMITED WESTWARD PROGRESS OF THE STRATUS PER
LATEST SATELLITE IMAGERY. AT THIS TIME...EXPECT SSW WINDS TO
CONTINUE AT KSAW WHICH WILL KEEP STRATUS OUT OF THAT AREA...BUT WITH
PROXIMITY CANNOT RULE OUT A BRIEF PERIOD OF MVFR CIGS UNTIL 5Z WHEN
WINDS SHIFT MORE WESTERLY. HIGHER DEWPOINTS OVER NRN MN WILL ADVECT
OVER THE WESTERN LAKE SUPERIOR THIS EVENING AND COMBINED WITH
UPSLOPE MAY GENERATE LOW END MVFR CIGS AT KCMX. BUT THESE LOWER
CIGS...IF THEY DEVELOP...SHOULD NOT LAST LONG AS DRIER AIR
EVENTUALLY WORKS IN BY 6Z. OTHER THAN THESE TWO POTENTIAL
ISSUES...VFR CONDITIONS EXPECTED THROUGH THE FORECAST.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EST TUE FEB 18 2014
WINDS ARE FORECAST TO BE LESS THAN 30 KTS THROUGH WED. POTENTIAL FOR
A VERY STRONG LOW PRESSURE SYSTEM THURSDAY INTO FRIDAY WITH PRESSURE
LOWER THAN 975MB OR 29 INCHES TO LIFT ACROSS LAKE SUPERIOR THURSDAY
NIGHT AND INTO NORTHERN ONTARIO ON FRIDAY. NW GALES LIKELY LATE
THURSDAY NIGHT WITH WESTERLY GALES FRIDAY AND FRIDAY NIGHT. EVEN A
RISK OF STORM FORCE WINDS IF THIS SYSTEM TRENDS SLIGHTLY STRONGER.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ006-007-012>014-085.
WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ002-004-009-010-084.
WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ005-011.
BLIZZARD WATCH FROM THURSDAY EVENING THROUGH FRIDAY EVENING FOR
MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLB
AVIATION...RJT
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
447 PM EST MON FEB 17 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 445 PM EST MON FEB 17 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH
THROUGH THE UPPER MS VALLEY WITH SEVERAL EMBEDDED SHRTWVS...THE
STRONGEST OF WHICH WAS LOCATED OVER CNTRL IL. MODERATE 700-300 MB
QVECTOR CONV FARTHER NORTH AHEAD OF A WEAKER SHRTWV OVER NW WI
SUPPORTED LIGHT TO MODERATE SNOW FORM NRN WI THROUGH UPPER MI.
TONIGHT...RADAR/SATELLITE TRENDS AND SHORT RANGE MODELS SUGGEST THAT
THE HEAVIER SNOW THIS EVENING WILL REMAIN ACROSS SRN PORTION OF THE
CWA...WHERE ADDITIONAL AMOUNTS OF 1 TO 3 INCHES ARE LIKELY AFTER
21Z. DEEP MOISTURE QUICKLY EXITS FROM WEST TO EAST THIS EVENING AS
SHORTWAVE DEPARTS SE OF REGION AND LEVEL RIDGING BUILDS IN WITH
STRONG MID LVL SUBSIDENCE AND DRYING LATE TONIGHT.
TUESDAY...ANOTHER WEAK SHRTWV MOVING THROUGH NRN ONTARIO WILL BRUSH
LAKE SUPERIOR. A BAND OF 290K ISENTROPIC LIFT AHEAD OF THE SHRTWV
MAY PRODUCE SOME LIGHT SNOW...BUT SHOULD REMAIN MAINLY NORTH OF
UPPER MI. OTHERWISE...925-850 MB RH FCST SUGGESTS THAT THERE WILL BE
ENOUGH CLEARING AND SUNSHINE FOR TEMPS TO CLIMB ABOVE NORMAL INTO
THE LOW AND MID 30S NORTH AND EAST AND THE UPPER 30S SOUTH.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 445 PM EST MON FEB 17 2014
PROGRESSIVE/LOWER AMPLITUDE PATTERN WILL LEAD TO A PERIOD OF WARMER
WEATHER AND ABOVE NORMAL TEMPS CENTERED ON THE MIDWEEK PERIOD.
HOWEVER...THE WARMTH WILL BE SHORT-LIVED. ALL INDICATIONS POINT
TOWARD THE RETURN OF A STRONG RIDGE CENTERED ALONG OR SLIGHTLY INLAND
OF THE WEST COAST THIS WEEKEND INTO NEXT WEEK. MANY OF THE GEM
ENSEMBLES OVER THE LAST FEW DAYS HAVE INDICATED A VERY COLD REGIME
FOR LATE FEB NEXT WEEK...AND NOW TODAYS 12Z ECMWF SHOWS A BITTERLY
COLD AIR MASS DUMPING INTO THE UPPER LAKES DURING THE MIDDLE OF NEXT
WEEK WITH A REINFORCING SHOT UPSTREAM YET. DETERMINISTIC GFS RUNS
OUT TO 16 DAYS HAVE SHOWN WIDE FLUCTUATION IN THE LAST DAY OR SO...
BUT RUNS KEEP APPEARING THAT MAINTAIN A VERY AMPLIFIED PATTERN OF
WRN RIDGE/ERN TROF...LEADING TO A VERY COLD PERIOD FOR THE UPPER
LAKES. IN ANY EVENT...AS THIS CHANGE BACK TO A COLD PATTERN GETS
UNDERWAY...ATTENTION WILL BE ON AN AMPLIFYING TROF SHIFTING ACROSS
THE CONUS DURING THE MID AND LATE WEEK. OVER THE LAST SEVERAL
DAYS...MODELS HAVE STRUGGLED WITH PHASING OF SHORTWAVES WITHIN THE
DEEPENING TROF. HOWEVER...WITH TODAYS 12Z MEDIUM RANGE MODEL
RUNS...THERE ARE SOLID TRENDS TOWARD MUCH BETTER AGREEMENT ON A SRN
STREAM WAVE LIFTING NE AND PHASING WITH A NRN BRANCH WAVE OVER AND
JUST NE OF THE GREAT LAKES. THIS WILL LEAD TO THE ONLY SIGNIFICANT
PCPN EVENT (SNOW AND MIXED PCPN) DURING THE LONG TERM PORTION OF THE
FCST. OUTSIDE OF THIS ONE EVENT...NOT MUCH PCPN IS EXPECTED DURING
THE LONG TERM.
BEGINNING TUE NIGHT...NEXT SHORTWAVE TROF WILL QUICKLY SHIFT ACROSS
THE WRN GREAT LAKES. WITH SEVERAL DISJOINTED VORT CENTERS COMPRISING
THE TROF...NOT EXPECTING MUCH IF ANY PCPN...ESPECIALLY WITH DEEP
LAYER FORCING/MID LEVEL MOISTURE EXITING TO THE E OF THE AREA
ALREADY IN THE EVENING. BEFORE THAT HAPPENS...MAY SEE A LITTLE BIT
OF -SN/FLURRY ACTIVITY OVER THE E EARLY IN THE EVENING. AFTER
THAT...QUESTION IS WHETHER THERE MIGHT BE SOME FLURRIES OR MORE
LIKELY -FZDZ AS TEMP PROFILE IN LINGERING GENERALLY SHALLOW MOISTURE
IS ABOVE -10C. UNDER W TO WNW LOW-LEVEL WINDS...BEST CHANCE WOULD BE
OVER THE UPSLOPE AREAS OF WRN UPPER MI AND PERHAPS THE FAR NE FCST
AREA AS WINDS VEER WNW THERE LATER IN THE NIGHT. SINCE ANY
ADDITIONAL MOISTENING THAT COULD BE PROVIDED BY LAKE SUPERIOR IS
VERY LIMITED AS THE LAKE IS NEARLY COMPLETELY ICED OVER...WILL HOLD
OFF ON INCLUDING A MENTION OF -FZDZ. TUE NIGHT WILL BE ONE OF THE
WARMER NIGHTS IN QUITE A WHILE UNDER PACIFIC AIR MASS WITH WINDS
HELPING TO KEEP TEMPS UP. EXPECT MINS IN THE TEENS TO LOWER 20S.
WED WILL BE A DRY DAY AS SHORTWAVE TROF SHIFTS E OF THE AREA AND
SHORTWAVE RIDGING BUILDS INTO THE WRN LAKES. WHILE THERE MIGHT BE
SOME LOW CLOUDS LINGERING INTO WED MORNING...EXPECT MOST AREAS TO
SEE A GOOD DISPLAY OF SUNSHINE WED. HIGHER MID TO LATE FEB SUN ANGLE
WORKING ON THE LOWER ALBEDO FORESTED TERRAIN WILL HELP TEMPS RISE
INTO THE 30S ACROSS THE BOARD. MAY NOT BE OUT OF THE QUESTION FOR A
FEW LOCATIONS TO REACH 40F WHERE DOWNSLOPING OCCURS. WITH W TO WNW
WINDS FOR MUCH OF THE DAY...TEMPS WILL BE COOLEST NEAR LAKE SUPERIOR
OVER WRN UPPER MI AND OVER THE NE FCST AREA. IN THOSE LOCATIONS...
TEMPS SHOULDN`T RISE ABOVE FREEZING.
AS ALLUDED TO ABOVE...MEDIUM RANGE GUIDANCE HAS STRONGLY TRENDED
TOWARD MUCH BETTER AGREEMENT WITH THE DETAILS OF AMPLIFYING TROF
SHIFTING ACROSS THE CONUS MID AND LATE WEEK. ALTHOUGH THE MODEL
AGREEMENT THAT HAS APPEARED WITH TODAYS 12Z MODEL RUNS IS RATHER
REMARKABLE GIVEN THE VERY RECENT DISAGREEMENT...THE SHORTWAVES
INVOLVED ARE STILL IN THE GULF OF ALASKA AND ALEUTIANS...SUGGESTING
CONTINUED ADJUSTMENTS ARE IN THE OFFING. THAT SAID...THE
GEM/GFS/ECMWF ARE IN EXCELLENT AGREEMENT TODAY SHOWING A SRN STREAM
SHORTWAVE MOVING OUT OVER THE SRN PLAINS THU AND THEN LIFTING NE AND
PHASING WITH NRN STREAM ENERGY OVER THE UPPER MISSISSIPPI VALLEY.
RESULT IS A SFC LOW OVER THE SRN PLAINS THU MORNING LIFTING NE
ACROSS NW IL AND THEN RAPIDLY DEEPENING AS IT MOVES JUST E OF KGRB
THEN ACROSS ERN LAKE SUPERIOR THU NIGHT. WITH 12HR HEIGHT FALLS OF
250-300M AT 500MB...THIS WILL BE A VERY DYNAMIC SYSTEM WITH A
RAPIDLY ORGANIZING/INTENSIFYING PCPN SHIELD AS IT MOVES ACROSS THE
UPPER LAKES. WITH SYSTEM TAPPING A GOOD FEED OF GULF MOISTURE...
STRONG DYNAMICS WILL MAKE THIS A SIGNIFICANT PCPN PRODUCER ACROSS
MUCH OF UPPER MI. BASED OFF 12Z MODELS WHICH ARE IN GOOD
AGREEMENT...PTYPE SHOULD BE JUST SNOW W OF LINE ROUGHLY FROM JUST NW
MENOMINEE TO AROUND MUNISING WITH A WINTRY MIX TO THE E FOR AT LEAST
A TIME. HOWEVER...UNTIL SHORTWAVES INVOLVED ARRIVE IN THE
CONUS/CANADA...EXPECT SOME FLUCTUATION IN SYSTEM STRENGTH/TRACK AND
THERMAL FIELDS/PTYPES. POPS WILL BE RAISED ACROSS THE BOARD TO
CATEGORICAL FOR AT LEAST A PORTION OF THU AFTN/NIGHT. DEPENDING ON
EXACTLY HOW STRONG THE LOW BECOMES...WINDS/BLSN COULD BECOME
SIGNIFICANT ON THE BACKSIDE. RIGHT NOW...IT APPEARS BACKSIDE WINDS
WILL BE FROM A W TO WNW DIRECTION. IF SO...THOUGH FALLING SNOW WILL
BE MUCH LIGHTER...BLIZZARD CONDITIONS WILL BE POSSIBLE OVER THE
KEWEENAW WITH THE ADDED COMPONENT OF BLSN OFF LAKE SUPERIOR ICE
COVER. STRONG WINDS WILL LIKELY LOOSEN UP ICE COVER AND CREATE
SUFFICIENT BREAKS FOR SOME LES OFF LAKE SUPERIOR AFTER THE SYNOPTIC
MOISTURE PULLS OUT FRI AND 850MB TEMPS FALL INTO THE MID -TEENS C.
ARCTIC AIR BECOMES RE-ESTABLISHED OVER THE GREAT LAKES OVER THE
WEEKEND INTO NEXT WEEK. HOW COLD IS UNCERTAIN...BUT TEMPS SHOULD BE
SOLIDLY BLO NORMAL WITH A TREND TO COLDER CONDITIONS EARLY NEXT WEEK
AND BEYOND. WHILE THERE MAY BE SOME -SN AT TIMES AND PROBABLY SOME
LIMITED LAKE EFFECT OFF LAKE SUPERIOR DUE TO FRACTURED ICE
COVER/SMALL OPEN WATER AREAS...NO PCPN OF SIGNIFICANCE IS
ANTICIPATED AT THIS POINT SAT THRU MON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 110 PM EST MON FEB 17 2014
WIDESPREAD SNOW WILL BRING IFR CONDITIONS TO THE TAF SITES THIS
AFTERNOON INTO THIS EVENING. THERE MAY ALSO BEE SOME PERIODS OF LIFR
VSBYS/CIGS BEFORE ALL SITES IMPROVE TO MVFR MONDAY EVENING.
HOWEVER...CONFIDENCE WITH THE TIMING/DURATION OF THE PERIODS IS LOW.
MVFR CONDITIONS OVERNIGHT ARE EXPECTED TO IMPROVE TO VFR TUE MORNING
AS DRIER MOVES IN BEHIND A FRONTAL SYSTEM.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 445 PM EST MON FEB 17 2014
WINDS ARE FORECAST TO BE LESS THAN 30 KTS THROUGH WED. THERE IS THE
POTENTIAL FOR A STRONG LOW PRESSURE SYSTEM TO MOVE THROUGH LAKE
SUPERIOR THURSDAY NIGHT AND INTO NORTHERN ONTARIO FRIDAY. THIS WOULD
LIKELY BRING A PERIOD OF NORTHWEST TO WEST GALES LATE THURSDAY NIGHT
THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST TUESDAY FOR MIZ006-007-
014-085.
WINTER WEATHER ADVISORY UNTIL 10 PM EST /9 PM CST/ THIS EVENING
FOR MIZ001-003>005-010>013-084.
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING
FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...ROLFSON
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
353 PM EST MON FEB 17 2014
.SHORT TERM... AFTERNOON THROUGH TONIGHT
THE WINTER WEATHER ADVISORY WILL REMAIN IN EFFECT TONIGHT FOR HIGH
END ADVISORY SNOW ACCUMULATION. THE RANGE OF 3 TO 6 INCHES WILL
LIKELY VERIFY CLOSER TO THE 6 INCH END OF THE RANGE FOR MOST
LOCATIONS. LOCALLY HIGHER AMOUNTS AND A SHORT FUSED WARNING
UPGRADE ALSO REMAINS IN PLAY AS THE POSITION AND CHARACTER OF
MESOSCALE FORCING BECOMES CLEARER. THIS WOULD MOST LIKELY BE IN
THE TRI CITIES TO NORTHERN THUMB BASED ON OBSERVATIONS AS THEY
BECOME AVAILABLE DURING THE LATE AFTERNOON INTO EARLY EVENING. THE
MAIN UNCERTAINTY WITH AN UPGRADE LIES WITH THE PROGRESSION VERSUS
PIVOT OF THE DEFORMATION AXIS ON THE NORTH FLANK OF THE SYSTEM AND
THE NORTHWARD PUSH OF THE DRY SLOT. OBSERVATIONS WILL BE
MONITORED FOR A PIVOT WHICH WOULD PERMIT HIGHER RATES FOR A LONGER
PERIOD OF TIME AND HIGHER SYSTEM TOTALS AND/OR 6 INCH AMOUNTS
COMING IN CLOSER TO 6 TO 9 HOUR TIME PERIOD. FARTHER SOUTH, A
CONVECTIVE COMPONENT IN THE FORCING WILL BRING HIGH SNOWFALL RATES
AND EVEN SOME GRAUPEL/SNOW PELLETS WITH A RUMBLE OF THUNDER AT
TIMES BEFORE THE MID LEVEL DRY SLOT CONFINES TOTAL ACCUMULATION
CLOSER TO 4 INCHES.
MID AFTERNOON SATELLITE IMAGERY SHOWS THE LOW PRESSURE SYSTEM OVER
ILLINOIS/INDIANA COMING TOGETHER IN A STRONGLY DYNAMIC FASHION.
VISIBILITY NEAR ZERO IN SURFACE OBSERVATIONS WITH SEVERAL CLUSTERS
OF CG LIGHTNING STRIKES DEPICTS THE CONVECTIVE NATURE OF THE
SITUATION, AS DOES THE SPECIAL 18Z KILX SOUNDING WITH BORDERLINE DRY
ADIABATIC LAPSE RATES IN THE 700-500 MB LAYER. NEAR TERM MODEL
FIELDS HAVE PICKED UP ON THIS AS A STRONG COMBINATION OF MID LEVEL
DCVA AND LOW LEVEL THETA-E ADVECTION ON 850 MB WIND PUSHING 50
KNOTS. THE WIND FIELD WILL EVENTUALLY GET CONVERTED TO TROWAL
FORCING WITH SPECIFIC HUMIDITY SETTLING IN AROUND 3 G/KG. THE
TROWAL/DEFORMATION AXIS IS EXPECTED TO SET UP NORTH OF THE
INTERSTATE 69 CORRIDOR AS THE SURFACE LOW DROPS FROM 1007 MB TO NEAR
1000 MB OVER THE EAST SHORE OF LAKE ST CLAIR BY MIDNIGHT. AS
MENTIONED ABOVE, THERE WILL BE CONVECTIVE INSTABILITY BOTH WITHIN
THE WARM ADVECTION PATTERN AND ON THE INTERIOR FLANK OF THE
TROWAL/THETA-E RIDGE. THIS THERMODYNAMIC ENVIRONMENT COUPLED WITH
THE STRONG WIND FIELD WILL RESULT IN SNOWFALL RATES IN THE 1-2 INCH
PER HOUR RANGE. IN ADDITION, MODEL SOUNDINGS INDICATE FAVORABLE
TEMPERATURE AND MOISTURE PROFILES THAT DEPICT A DGZ DEPTH ROUGHLY
FROM 600 TO 800 MB THAT SHOULD SUPPORT SNOW RATIO IN THE 10-13:1
RANGE. THE NAM AND THE RAP MODELS SEEMINGLY HAVE ALSO PICKED UP ON
THE COMBINATION OF HIGHER MOISTURE CONTENT AND STRONG DYNAMIC
FORCING REFLECTED IN LIQUID EQUIVALENT QPF RANGING FROM 0.6 TO 0.8
IN THE 12 HOUR PERIOD FROM 18Z TO 06Z TONIGHT. THIS ILLUSTRATES THE
POTENTIAL FOR OVERACHIEVEMENT SHOULD MESOSCALE FORCING STALL OVER
ANY ONE REGION OF SE MICHIGAN DURING THE EVENING. THE SYSTEM WILL
THEN MOVE EASTWARD ENOUGH OVERNIGHT FOR SNOW TO DIMINISH ON THE
WESTERN FLANK OF THE UPPER CIRCULATION BY SUNRISE TUESDAY
MORNING.
&&
.LONG TERM...TUESDAY THROUGH SUNDAY
PROGRESSIVE LOW AMPLITUDE LONGWAVE PATTERN WILL CONTINUE THROUGH THE
MID WEEK BEFORE BROAD TROUGH SETS UP ACROSS MUCH OF THE CENTRAL
CONUS AND GREAT LAKES THROUGH THE WEEKEND. THE ENERGETIC JET WILL
SHIFT FAR ENOUGH NORTH TO ALLOW A WARMUP THROUGH THE MID WEEK PERIOD
WITH TEMPS IN THE MID 30S AND EVEN NEAR 40F BEFORE THE NEXT TROUGH
AND STRONG SYSTEM PUSHES THE MILD AIR SOUTH DROPPING US BACK INTO
THE 20S. THE DIFFICULTY IN THE TEMP FORECAST WILL BE TAKING INTO
ACCOUNT THE DEEP SNOWPACK THAT IS PRESENT ACROSS THE AREA.
THERE MAY BE SOME LINGERING LIGHT SNOW SHOWERS OR FLURRIES OVER THE
AREA TUESDAY MORNING AS THE BACK EDGE OF MONDAYS SYSTEM HOLDS OVER
THE AREA. AS THIS EXITS...A FRONTAL BOUNDARY EXTENDING SOUTHEAST
FROM A MUCH LARGER SYSTEM OVER CENTRAL CANADA WILL LIFT NORTH
THROUGH THE GREAT LAKES. THIS...ALONG WITH A SHORTWAVE RIDGE
BUILDING ACROSS THE AREA...WILL LEAD TO INCREASING SW FLOW AND A WAA
PATTERN. LOW LEVEL TEMPS WILL CLIMB FROM -8C/-12C AT 850MB/925MB
CURRENTLY UP TO AROUND 3-5C BY LATE TUESDAY AFTERNOON. MODEL
SOUNDING KEEP THE BOUNDARY MUCH COOLER THOUGH WITH TEMPS STILL BELOW
0C. GUSTY WINDS SHOULD BE ABLE TO MIX SOME OF THAT DOWN BUT THE COLD
DEEP SNOWPACK WILL WORK AGAINST IT MUCH OF TIME. WITH THE WARMEST
AIR TAKING SO LONG TO GET INTO THE AREA...HAVE KEPT HIGH TEMPS
AROUND THE MID 30S FOR NOW.
WEDNESDAYS FORECAST WILL ALSO BE A TRICKY ONE AS A COLD FRONT WILL
SWEEP THROUGH THE AREA IN THE MORNING. THERE IS A LOW CHANCE THAT WE
COULD SEE SOME SNOW FLAKES FROM THIS FRONT BUT NOT MUCH IN THE WAY
OF ACCUMULATIONS. LOW LEVEL THERMAL PROFILE DOES NOT TANK MUCH AS
RIDGING QUICKLY BUILDS IN THE WAKE OF THIS FRONT. MID LEVELS DO COOL
QUITE A BIT THOUGH. WITH SFC HIGH PRESSURE BRINGING MOSTLY CLEAR
SKIES...SHOULD NOT BE TOO HARD TO GET BACK INTO THE MID/UPPER 30S
EVEN WITH SFC-800MB TEMPS HOVERING AROUND 0C. POTENTIAL TO ADD A
DEGREE OR TWO TO THE FORECAST BUT ONCE AGAIN WOULD LIKE TO SEE HOW
SEVERE THE SNOW PACK AFFECTS THINGS BEFORE GOING TOO HIGH.
LOW PRESSURE ORIGINATING FROM THE TEXAS PANHANDLE WILL TRACK
NORTHEAST TOWARD THE GREAT LAKES BY THURSDAY. THE TRACK AND
ORIENTATION OF THIS SYSTEM WILL ALLOW MOISTURE FROM THE GULF OF
MEXICO TO ENHANCE QPF AMOUNTS AND ALSO WARM THE SYSTEM CONSIDERABLY.
EXPECTING BETWEEN 0.5 AND 1.0 INCHES OF RAINFALL ALONG WITH
CONSIDERABLE SNOWMELT FROM THIS SYSTEM...WHICH MAY LEAD TO
RIVER/AREAL FLOOD ISSUES. AVERAGE SNOW CORES ACROSS THE REGION ARE
OVER 3 INCHES OF LIQUID EQUIVALENT IN 16 INCHES OF SNOW
DEPTH...EXCLUDING THE 3-6 INCHES EXPECTED TONIGHT.
&&
.MARINE...
A LOW PRESSURE SYSTEM WILL TRACK FROM SOUTH OF LAKE MICHIGAN ACROSS
TO WESTERN LAKE ERIE AND NORTHEAST THROUGH LAKE ST CLAIR TONIGHT.
THIS WILL PRODUCE A PERIOD OF HEAVY SNOW THIS EVENING. GUSTY
WESTERLY WINDS WILL FOLLOW THE SYSTEM ON TUESDAY MORNING WITH THE
POTENTIAL TO BRIEFLY TOP 25 KNOTS OVER LAKE ERIE AND LAKE ST CLAIR.
WINDS WILL RELAX SOME TUESDAY AFTERNOON AS A RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION. A WEAK COLD FRONT COULD AGAIN LEAD TO GUSTY
WINDS ON WEDNESDAY BUT THIS TIME OUT OF THE NORTHWEST. SUBSTANTIAL
ICE COVERAGE ACROSS ALL MARINE AREAS WILL KEEP WAVES ABSENT FROM ALL
FORECAST PRODUCTS.
&&
.AVIATION...ISSUED 1258 PM EST MON FEB 17 2014
//DISCUSSION...
VFR CONDITIONS WILL BE IN PLACE THROUGH MID AFTERNOON FOLLOWED BY
QUICKLY DETERIORATING CEILING AND VISIBILITY AS SNOW SPREADS OVER
THE REGION. LATE AFTERNOON TIMING REMAINS ON TRACK WITH FAIRLY
UNIFORM ONSET AND 3-6 INCH TOTAL ACCUMULATION EXPECTED ACROSS THE
TERMINAL CORRIDOR, LIKELY VERIFYING AT THE HIGH END OF THE RANGE.
THE SNOW WILL BE INTERMITTENT IFR UNTIL LOW LEVELS SATURATE AND THEN
WILL RAMP UP CONSIDERABLY DURING THE EVENING ROUGHLY DURING THE
00Z-06Z PERIOD WHEN LIFR IS EXPECTED. THERE IS ALSO POTENTIAL FOR
VISIBILITY NEAR ZERO AT TIMES BUT TIMING ON THIS REMAINS A BIT
UNCERTAIN FOR INCLUSION IN THIS FORECAST ISSUANCE. LATER UPDATES
COULD INCLUDE A VLIFR WINDOW PERHAPS AT DTW INITIALLY AND THEN AT
POINTS FARTHER NORTH DEPENDING ON AFTERNOON OBSERVATIONS UPSTREAM.
THE SNOW WILL DIMINISH DURING THE OVERNIGHT AND GRADUALLY GIVE WAY
TO VFR CEILING DURING TUESDAY MORNING ACCOMPANIED BY A GUSTY WEST
WIND.
FOR DTW... VFR CEILING WILL DROP QUICKLY BELOW 5000 FEET AFTER 20Z
WITH ONSET OF LIGHT SNOW. RATES WILL THEN INCREASE RAPIDLY TOWARD
00Z WITH UP TO AN INCH PER HOUR EXPECTED AT PEAK INTENSITY 00Z-04Z.
TOTAL ACCUMULATION OF 3-6 INCHES THAT HAS BEEN CALLED FOR WILL
LIKELY VERIFY CLOSER TO THE 6 INCH END OF THE RANGE.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILING BELOW 5000 FT LATE AFTERNOON THROUGH
TONIGHT.
* HIGH CONFIDENCE IN PRECIPITATION TYPE AS SNOW.
* MEDIUM CONFIDENCE IN VISIBILITY 1/2 MILE OR LESS IN HEAVY SNOW
DURING THE EVENING.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY...MIZ047-MIZ048-MIZ049-MIZ053-MIZ054-MIZ055-
MIZ060-MIZ061-MIZ062-MIZ063-MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-
MIZ082-MIZ083...UNTIL 4 AM TUESDAY.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...BT
LONG TERM....DRK/MM
MARINE.......DRK
AVIATION.....BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
111 PM EST MON FEB 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 522 AM EST MON FEB 17 2014
09Z WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN
ACROSS THE WEST AND CENTRAL CONUS WITH A MID/UPPER LEVEL TROUGH AND
SEVERAL EMBEDDED SHRTWVS EMERGING FROM THE NRN ROCKIES INTO THE WRN
PLAINS. WAA/ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE TROUGH HAS
ALLOWED MID-HIGH CLOUDS TO SPREAD INTO THE FCST AREA FM THE WEST. AS
A RESULT...MUCH BELOW ZERO TEMPS FM LAST EVENING OVER CENTRAL AND
EASTERN COUNTIES OF THE CWA HAVE BEGUN TO MODERATE ABV ZERO AT MANY
LOCATIONS. SOME LIGHT SNOW IS ALSO NOW APPEARING ON RADAR AND SFC
OBS OVER NCNTRL WI AND FAR WRN UPR MI.
TODAY...MODELS IN GENERALLY GOOD AGREEMENT ON DEPICTION/MOVEMENT OF
MAIN SHORTWAVE NOW OVER WRN NEBRASKA TRACKING IT AND ASSOC SFC LOW
ESE THROUGH CNTRL ILLINOIS AND NRN INDIANA LATE AFTERNOON/EARLY
EVENING. NORTHERN SHORTWAVE OVER THE DAKOTAS APPEARS TO BECOME MORE
SHEARED OUT WITH TIME AS IT APPROACHES THE WRN LAKES LATE THIS
AFTERNOON. THIS IS REFLECTED IN 700-300 MB LAYER Q-VECTORS WHICH
SHOWS BEST CONV/LIFT GENERALLY PASSING SOUTH AND EAST OF THE FCST
AREA THIS AFTERNOON. ALSO A LIMITING FACTOR FOR HEAVY SNOW TODAY
OVER OUR AREA IS THE VERY DRY AIRMASS ALREADY IN PLACE AS NOTED ON
00Z GRB AND APX SOUNDINGS. CONSEQUENTLY..IT WILL TAKE LONGER FOR
COLUMN TO MOISTEN FM ISENTROPIC ASCENT AS THUS WILL LIKELY LIMIT
SNOW AMOUNTS SOMEWHAT. CONTINUED THE PREV FCST TREND OF GOING ON THE
LOWER END OF MODEL GUIDANCE FOR QPF AMOUNTS RANGING FROM .15 INCH
FAR EAST TO NEARLY .3 INCH NEAR MNM. USING COBB METHOD AVERAGED SLR
VALUES AROUND 17:1...TOTAL SNOW AMOUNTS FROM THIS SYSTEM WILL LIKELY
FALL INTO THE 3 TO 5 INCH RANGE ACROSS MUCH OF THE AREA...BUT FAR NE
CWA MAY STRUGGLE TO REACH MINIMAL ADVISORY CRITERIA OF 3 INCHES DUE
TO EFFECTS OF ATTENDANT DRY AIR DELAYING ARRIVAL OF PCPN UNTIL
MAINLY AFTERNOON. SSE WINDS ARE EXPECTED TO INCREASE AND GUST NEAR
25 MPH AT TIMES BY LATE MORNING/AFTERNOON WHICH MAY CONTRIBUTE TO
SOME BLSN BUT NOTHING OF GREAT SIGNIFICANCE. CONTINUED THE WINTER
WEATHER ADVISORIES ACROSS THE AREA BUT GIVEN POTENTIAL LIMITING
FACTORS MENTIONED ABOVE...LOWERED HIGH END OF ADVISORY RANGE TO 5
INCHES FOR WEST AND CENTRAL COUNTIES AND WENT GENERALLY 2 TO 4
INCHES FOR ERN COUNTIES.
TONIGHT...DEEP MOISTURE QUICKLY EXITS FROM WEST TO EAST THIS EVENING
AS SHORTWAVE DEPARTS SE OF REGION AND MODEL SOUNDINGS SHOW GOOD
MID-LVL SUBSIDENCE/DRYING LATE TONIGHT. WAA DEVELOPING FROM THE WEST
LATE TONIGHT AHEAD OF NEXT SHORTWAVE APPROACHING FM THE NRN PLAINS
MAY BRIEFLY ALLOW FOR SOME PATCHY FREEZING DRIZZLE TO FORM OVER ERN
COUNTIES IN UPSLOPE SOUTHERLY FLOW AS DGZ DRIES OUT...BUT STILL NOT
CONFIDENT ENOUGH TO INCLUDE IN FCST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 522 AM EST MON FEB 17 2014
ZONAL FLOW BRINGS MULTIPLE SHORTWAVES ACROSS THE REGION THROUGH THE
UPCOMING WEEK. STRONGEST WAVE BEYOND TODAY IS STILL ON TRACK TO
IMPACT GREAT LAKES THURSDAY AND THURSDAY NIGHT THOUGH CURRENT
INDICATIONS ARE THAT BIGGEST IMPACT WILL STAY MORE OVER THE OHIO
VALLEY AND LOWER GREAT LAKES. OPPORTUNITY TO FINALLY REACH ABOVE
FREEZING WFO MARQUETTE WILL BE THE MIDDLE OF THIS WEEK...THOUGH IT
IS NOT LOOKING AS SURE AS IT DID THE LAST COUPLE DAYS. WHATEVER WARM
UP OCCURS WILL NOT LAST AS IN WAKE OF THE LATE WEEK SYSTEM LARGER
SCALE TROUGHING WITH COLDER TEMPERATURES DEVELOPS OVER MUCH OF THE
CNTRL CONUS BY NEXT WEEKEND.
TUESDAY AND TUESDAY NIGHT...SHORTWAVE AND SFC LOW THAT ARE BRINGING
SNOW TO REGION TODAY HEAD OFF ACROSS NEW ENGLAND. WESTERLY FLOW
ALOFT WILL BRING ADDITIONAL SHORTWAVES FROM THE NORTHERN PLAINS TO
THE WESTERN GREAT LAKES BY TUESDAY AFTN. STRONGEST WAVE ON TUESDAY
CROSSES SOUTHERN MANITOBA INTO ONTARIO...WITH ASSOCIATED 995-1000MB
SFC LOW MOVING ACROSS ONTARIO IN THE AFTN...TO THE NORTH OF LK
SUPERIOR. SOUNDINGS SHOW PLENTY OF MID LEVEL MOISTURE TO H7 BUT ALSO
HAVE A LOT OF DRY AIR BLO THAT. ONLY EXCEPTION IS OVER EASTERN CWA
WHERE THERE MAY BE ENOUGH LOW-LEVEL MOISTURE TO RESULT IN SOME FREEZING
DRIZZLE IN THE MORNING. H85 FRONT LIKELY WILL BE VCNTY OF SOUTHERN
LK SUPERIOR SO KEPT SLIGHT CHANCES MAINLY OVER LK SUPERIOR AND IN THE
FAR NORTH CWA. WARMEST TEMPS OVER FAR WEST WHERE MAY BE SOME BKN
SUNSHINE TO START THE DAY. H925-H9 TEMPS STILL AROUND 0C SO WOULD NOT
TAKE MUCH MIXING TO PUNCH TEMPS INTO AT LEAST MID 30S. FARTHER TO THE
EAST...MORE CLOUDS AND SW WINDS OFF MAINLY ICE COVERED LK MICHIGAN
SHOULD KEEP TEMPS BLO FREEZING. GENERALLY QUIET TUESDAY NIGHT THOUGH
WILL HAVE TO WATCH WESTERN CWA LATE AS THERE MAY BE ENOUGH LOW-LEVEL
MOISTURE AND UPSLOPE IN WAKE OF SFC TROUGH WORKING THROUGH TO PRODUCE
LGT PRECIP. SOUNDINGS WOULD SUPPORT SOME RISK OF FREEZING DRIZZLE
WITH LIMITED MOISTURE IN DGZ...THAT IS IF THERE IS SUFFICIENT
MOISTURE IN THE LOW-LEVELS.
WEDNESDAY...EARLIER IT LOOKED AS THERE WOULD BE NW WINDS IN WAKE OF
TROUGH ON TUESDAY TO RESULT IN COOLING FOR THE NORTH OFF ICE COVERED
LK SUPERIOR. WINDS IN BLYR NOW MORE WRLY WHICH OPENS POSSIBILITY OF
WARMER TEMPERATURES OVER MUCH OF CWA...EXCEPT ALONG IMMEDIATED LK
SUPERIOR SHORE OVER WESTERN CWA AND ACROSS KEWEENAW PENINSULA. BIAS
CORRECTED GUIDANCE INDICATED MID 30S FOR MOST AREAS WITH EVEN TEMPS
AROUND 40 IN THE SCNTRL. USED THIS SOLN AS A BLEND INTO PREVIOUS
FORECAST WHICH RESULTED IN SOLID MID 30S FOR GOOD PART OF CWA. COULD
BE SOME LOW-LEVEL MOISTURE TO BEGIN THE DAY...BUT THIS SHOULD SCOUR
OUT BY AFTN. OVERALL A QUIET WEATHER DAY OUT AHEAD OF STRONGER
LOW-MID LEVEL TROUGHING DEVELOPING OVER THE CNTRL CONUS.
THURSDAY AND FRIDAY...FATE OF THE LATE WEEK SYSTEM IS STILL CLOUDED
WITH MUCH UNCERTAINTY AT THIS POINT. ECMWF AND GFS TRENDED BACK TO
MORE WRAPPED UP AND WETTER SYSTEM AS SOUTHERN BRANCH SHORTWAVE
DOMINATES AND ALLOWS THE LARGER SCALE SHORTWAVE TROUGH TO BECOME
MORE NEGATIVELY TILTED AS IT SWEEPS ACROSS UPPER GREAT LAKES.
RESULTING SFC LOW DEEPENS TO SUB 980MB LOW OVER UPPER LAKES BY
THURSDAY NIGHT. AS ALLUDED TO YDY...SHORTWAVES THAT HELP FORM THIS
SYSTEM ARE STILL AROUND THE ALLUTIANS AND MAYBE EVEN FARTHER WEST
THAN THAT OVER NORTHERN RUSSIA. SO...ALTHOUGH THE 00Z ECMWF SOLUTION
COULD OCCUR AS IT SHOWED SOMETHING SIMILAR TWO DAYS AGO...IT IS
ESSENTIALLY ONE OF MANY SOLNS THAT REPRESENT THE MODEL ENSEMBLE AT
THIS POINT. ONLY CHANGE THAT WAS MADE COMPARED TO CONSENSUS WAS TO
LINGER CHANCE POPS ON THURSDAY NIGHT IN CASE THE SLOWER/WRAPPED UP
IDEA IS CORRECT. ALSO BROUGHT CHANCE FOR RAIN FARTHER NORTH OVER
EASTERN CWA. SEEMS THAT IF THE WARMER IDEA IS RIGHT...FZRA COULD
ALSO BE AN ISSUE TOO DUE TO LIMITED LOW-LEVEL WARM AIR ADVECTION BLO
H85 OR MAYBE JUST FROM THE RAIN FREEZING ON SUB FREEZING ROAD
SURFACES DUE TO THE PERSISTENT CHILL THAT HAS BEEN WITH US SINCE
EARLY DECEMBER. EVEN THOUGH THE SPECIFICS WITH THIS SYSTEM ARE FAR
FROM CERTAIN AND WILL LIKELY CHANGE UNTIL LATER THIS WEEK...THINK IT
IS WORTH A HEADS UP MENTION IN THE HAZARDOUS WEATHER OUTLOOK.
PRIMARY ISSUE INTO FRIDAY WILL BE STRONGER WINDS CLOSER TO LK
SUPERIOR WITH SMALL CHANCES OF SNOW SHOWERS IN LINGERING CYCLONIC
MOIST FLOW ON BACKSIDE OF THE DEPARTING LOW PRESSURE SYSTEM. THE
WARM UP WILL BE OVER BUT TEMPS WILL BE AROUND NORMAL WITH READINGS
IN THE MID TO UPPER 20S.
UNCERTAINTY HIGH BEYOND FRIDAY. MODEL CONSENSUS WAS USED FOR NOW
WHICH FEATURES PLETHORA OF SLIGHT CHANCE POPS. SEEMS THAT IDEA OF
SHORTWAVE LIFTING BACK ACROSS THE AREA AND BRINGING SOME LGT SNOW
IS OFF THE TABLE NOW AS THAT SYSTEM IS MUCH WEAKER AND FCST TO
REMAIN WELL TO THE SOUTH AND EAST OF CWA IF IT IS THERE AT ALL.
TEMPS SATURDAY IN THE TEENS AND LOWER 20S...WITH MORE NOTABLE
COOLING FOR SUNDAY WITH HIGHS IN THE LOWER TO MIDDLE TEENS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 110 PM EST MON FEB 17 2014
WIDESPREAD SNOW WILL BRING IFR CONDITIONS TO THE TAF SITES THIS
AFTERNOON INTO THIS EVENING. THERE MAY ALSO BEE SOME PERIODS OF LIFR
VSBYS/CIGS BEFORE ALL SITES IMPROVE TO MVFR MONDAY EVENING.
HOWEVER...CONFIDENCE WITH THE TIMING/DURATION OF THE PERIODS IS LOW.
MVFR CONDITIONS OVERNIGHT ARE EXPECTED TO IMPROVE TO VFR TUE MORNING
AS DRIER MOVES IN BEHIND A FRONTAL SYSTEM.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 522 AM EST MON FEB 17 2014
WINDS ARE FORECAST TO BE LESS THAN 30 KTS THIS WEEK. LOW PRESSURE
SYSTEM MOVING THROUGH LATE IN THE WEEK MAY RESULT IN STRONGER WINDS
THAN CURRENTLY FORECAST...MAINLY ON THURSDAY AFTERNOON AND THURSDAY
NIGHT. GALES MAY EVEN OCCUR. ONCE THIS LOW LIFTS TO THE NORTH...WEST
WINDS TO 30 KTS OR GALES APPEAR LIKELY ON FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST TUESDAY FOR MIZ006-007-
014-085.
WINTER WEATHER ADVISORY UNTIL 10 PM EST /9 PM CST/ THIS EVENING
FOR MIZ001-003>005-010>013-084.
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING
FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
727 AM EST MON FEB 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 522 AM EST MON FEB 17 2014
09Z WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN
ACROSS THE WEST AND CENTRAL CONUS WITH A MID/UPPER LEVEL TROUGH AND
SEVERAL EMBEDDED SHRTWVS EMERGING FROM THE NRN ROCKIES INTO THE WRN
PLAINS. WAA/ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE TROUGH HAS
ALLOWED MID-HIGH CLOUDS TO SPREAD INTO THE FCST AREA FM THE WEST. AS
A RESULT...MUCH BELOW ZERO TEMPS FM LAST EVENING OVER CENTRAL AND
EASTERN COUNTIES OF THE CWA HAVE BEGUN TO MODERATE ABV ZERO AT MANY
LOCATIONS. SOME LIGHT SNOW IS ALSO NOW APPEARING ON RADAR AND SFC
OBS OVER NCNTRL WI AND FAR WRN UPR MI.
TODAY...MODELS IN GENERALLY GOOD AGREEMENT ON DEPICTION/MOVEMENT OF
MAIN SHORTWAVE NOW OVER WRN NEBRASKA TRACKING IT AND ASSOC SFC LOW
ESE THROUGH CNTRL ILLINOIS AND NRN INDIANA LATE AFTERNOON/EARLY
EVENING. NORTHERN SHORTWAVE OVER THE DAKOTAS APPEARS TO BECOME MORE
SHEARED OUT WITH TIME AS IT APPROACHES THE WRN LAKES LATE THIS
AFTERNOON. THIS IS REFLECTED IN 700-300 MB LAYER Q-VECTORS WHICH
SHOWS BEST CONV/LIFT GENERALLY PASSING SOUTH AND EAST OF THE FCST
AREA THIS AFTERNOON. ALSO A LIMITING FACTOR FOR HEAVY SNOW TODAY
OVER OUR AREA IS THE VERY DRY AIRMASS ALREADY IN PLACE AS NOTED ON
00Z GRB AND APX SOUNDINGS. CONSEQUENTLY..IT WILL TAKE LONGER FOR
COLUMN TO MOISTEN FM ISENTROPIC ASCENT AS THUS WILL LIKELY LIMIT
SNOW AMOUNTS SOMEWHAT. CONTINUED THE PREV FCST TREND OF GOING ON THE
LOWER END OF MODEL GUIDANCE FOR QPF AMOUNTS RANGING FROM .15 INCH
FAR EAST TO NEARLY .3 INCH NEAR MNM. USING COBB METHOD AVERAGED SLR
VALUES AROUND 17:1...TOTAL SNOW AMOUNTS FROM THIS SYSTEM WILL LIKELY
FALL INTO THE 3 TO 5 INCH RANGE ACROSS MUCH OF THE AREA...BUT FAR NE
CWA MAY STRUGGLE TO REACH MINIMAL ADVISORY CRITERIA OF 3 INCHES DUE
TO EFFECTS OF ATTENDANT DRY AIR DELAYING ARRIVAL OF PCPN UNTIL
MAINLY AFTERNOON. SSE WINDS ARE EXPECTED TO INCREASE AND GUST NEAR
25 MPH AT TIMES BY LATE MORNING/AFTERNOON WHICH MAY CONTRIBUTE TO
SOME BLSN BUT NOTHING OF GREAT SIGNIFICANCE. CONTINUED THE WINTER
WEATHER ADVISORIES ACROSS THE AREA BUT GIVEN POTENTIAL LIMITING
FACTORS MENTIONED ABOVE...LOWERED HIGH END OF ADVISORY RANGE TO 5
INCHES FOR WEST AND CENTRAL COUNTIES AND WENT GENERALLY 2 TO 4
INCHES FOR ERN COUNTIES.
TONIGHT...DEEP MOISTURE QUICKLY EXITS FROM WEST TO EAST THIS EVENING
AS SHORTWAVE DEPARTS SE OF REGION AND MODEL SOUNDINGS SHOW GOOD
MID-LVL SUBSIDENCE/DRYING LATE TONIGHT. WAA DEVELOPING FROM THE WEST
LATE TONIGHT AHEAD OF NEXT SHORTWAVE APPROACHING FM THE NRN PLAINS
MAY BRIEFLY ALLOW FOR SOME PATCHY FREEZING DRIZZLE TO FORM OVER ERN
COUNTIES IN UPSLOPE SOUTHERLY FLOW AS DGZ DRIES OUT...BUT STILL NOT
CONFIDENT ENOUGH TO INCLUDE IN FCST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 522 AM EST MON FEB 17 2014
ZONAL FLOW BRINGS MULTIPLE SHORTWAVES ACROSS THE REGION THROUGH THE
UPCOMING WEEK. STRONGEST WAVE BEYOND TODAY IS STILL ON TRACK TO
IMPACT GREAT LAKES THURSDAY AND THURSDAY NIGHT THOUGH CURRENT
INDICATIONS ARE THAT BIGGEST IMPACT WILL STAY MORE OVER THE OHIO
VALLEY AND LOWER GREAT LAKES. OPPORTUNITY TO FINALLY REACH ABOVE
FREEZING WFO MARQUETTE WILL BE THE MIDDLE OF THIS WEEK...THOUGH IT
IS NOT LOOKING AS SURE AS IT DID THE LAST COUPLE DAYS. WHATEVER WARM
UP OCCURS WILL NOT LAST AS IN WAKE OF THE LATE WEEK SYSTEM LARGER
SCALE TROUGHING WITH COLDER TEMPERATURES DEVELOPS OVER MUCH OF THE
CNTRL CONUS BY NEXT WEEKEND.
TUESDAY AND TUESDAY NIGHT...SHORTWAVE AND SFC LOW THAT ARE BRINGING
SNOW TO REGION TODAY HEAD OFF ACROSS NEW ENGLAND. WESTERLY FLOW
ALOFT WILL BRING ADDITIONAL SHORTWAVES FROM THE NORTHERN PLAINS TO
THE WESTERN GREAT LAKES BY TUESDAY AFTN. STRONGEST WAVE ON TUESDAY
CROSSES SOUTHERN MANITOBA INTO ONTARIO...WITH ASSOCIATED 995-1000MB
SFC LOW MOVING ACROSS ONTARIO IN THE AFTN...TO THE NORTH OF LK
SUPERIOR. SOUNDINGS SHOW PLENTY OF MID LEVEL MOISTURE TO H7 BUT ALSO
HAVE A LOT OF DRY AIR BLO THAT. ONLY EXCEPTION IS OVER EASTERN CWA
WHERE THERE MAY BE ENOUGH LOW-LEVEL MOISTURE TO RESULT IN SOME FREEZING
DRIZZLE IN THE MORNING. H85 FRONT LIKELY WILL BE VCNTY OF SOUTHERN
LK SUPERIOR SO KEPT SLIGHT CHANCES MAINLY OVER LK SUPERIOR AND IN THE
FAR NORTH CWA. WARMEST TEMPS OVER FAR WEST WHERE MAY BE SOME BKN
SUNSHINE TO START THE DAY. H925-H9 TEMPS STILL AROUND 0C SO WOULD NOT
TAKE MUCH MIXING TO PUNCH TEMPS INTO AT LEAST MID 30S. FARTHER TO THE
EAST...MORE CLOUDS AND SW WINDS OFF MAINLY ICE COVERED LK MICHIGAN
SHOULD KEEP TEMPS BLO FREEZING. GENERALLY QUIET TUESDAY NIGHT THOUGH
WILL HAVE TO WATCH WESTERN CWA LATE AS THERE MAY BE ENOUGH LOW-LEVEL
MOISTURE AND UPSLOPE IN WAKE OF SFC TROUGH WORKING THROUGH TO PRODUCE
LGT PRECIP. SOUNDINGS WOULD SUPPORT SOME RISK OF FREEZING DRIZZLE
WITH LIMITED MOISTURE IN DGZ...THAT IS IF THERE IS SUFFICIENT
MOISTURE IN THE LOW-LEVELS.
WEDNESDAY...EARLIER IT LOOKED AS THERE WOULD BE NW WINDS IN WAKE OF
TROUGH ON TUESDAY TO RESULT IN COOLING FOR THE NORTH OFF ICE COVERED
LK SUPERIOR. WINDS IN BLYR NOW MORE WRLY WHICH OPENS POSSIBILITY OF
WARMER TEMPERATURES OVER MUCH OF CWA...EXCEPT ALONG IMMEDIATED LK
SUPERIOR SHORE OVER WESTERN CWA AND ACROSS KEWEENAW PENINSULA. BIAS
CORRECTED GUIDANCE INDICATED MID 30S FOR MOST AREAS WITH EVEN TEMPS
AROUND 40 IN THE SCNTRL. USED THIS SOLN AS A BLEND INTO PREVIOUS
FORECAST WHICH RESULTED IN SOLID MID 30S FOR GOOD PART OF CWA. COULD
BE SOME LOW-LEVEL MOISTURE TO BEGIN THE DAY...BUT THIS SHOULD SCOUR
OUT BY AFTN. OVERALL A QUIET WEATHER DAY OUT AHEAD OF STRONGER
LOW-MID LEVEL TROUGHING DEVELOPING OVER THE CNTRL CONUS.
THURSDAY AND FRIDAY...FATE OF THE LATE WEEK SYSTEM IS STILL CLOUDED
WITH MUCH UNCERTAINTY AT THIS POINT. ECMWF AND GFS TRENDED BACK TO
MORE WRAPPED UP AND WETTER SYSTEM AS SOUTHERN BRANCH SHORTWAVE
DOMINATES AND ALLOWS THE LARGER SCALE SHORTWAVE TROUGH TO BECOME
MORE NEGATIVELY TILTED AS IT SWEEPS ACROSS UPPER GREAT LAKES.
RESULTING SFC LOW DEEPENS TO SUB 980MB LOW OVER UPPER LAKES BY
THURSDAY NIGHT. AS ALLUDED TO YDY...SHORTWAVES THAT HELP FORM THIS
SYSTEM ARE STILL AROUND THE ALLUTIANS AND MAYBE EVEN FARTHER WEST
THAN THAT OVER NORTHERN RUSSIA. SO...ALTHOUGH THE 00Z ECMWF SOLUTION
COULD OCCUR AS IT SHOWED SOMETHING SIMILAR TWO DAYS AGO...IT IS
ESSENTIALLY ONE OF MANY SOLNS THAT REPRESENT THE MODEL ENSEMBLE AT
THIS POINT. ONLY CHANGE THAT WAS MADE COMPARED TO CONSENSUS WAS TO
LINGER CHANCE POPS ON THURSDAY NIGHT IN CASE THE SLOWER/WRAPPED UP
IDEA IS CORRECT. ALSO BROUGHT CHANCE FOR RAIN FARTHER NORTH OVER
EASTERN CWA. SEEMS THAT IF THE WARMER IDEA IS RIGHT...FZRA COULD
ALSO BE AN ISSUE TOO DUE TO LIMITED LOW-LEVEL WARM AIR ADVECTION BLO
H85 OR MAYBE JUST FROM THE RAIN FREEZING ON SUB FREEZING ROAD
SURFACES DUE TO THE PERSISTENT CHILL THAT HAS BEEN WITH US SINCE
EARLY DECEMBER. EVEN THOUGH THE SPECIFICS WITH THIS SYSTEM ARE FAR
FROM CERTAIN AND WILL LIKELY CHANGE UNTIL LATER THIS WEEK...THINK IT
IS WORTH A HEADS UP MENTION IN THE HAZARDOUS WEATHER OUTLOOK.
PRIMARY ISSUE INTO FRIDAY WILL BE STRONGER WINDS CLOSER TO LK
SUPERIOR WITH SMALL CHANCES OF SNOW SHOWERS IN LINGERING CYCLONIC
MOIST FLOW ON BACKSIDE OF THE DEPARTING LOW PRESSURE SYSTEM. THE
WARM UP WILL BE OVER BUT TEMPS WILL BE AROUND NORMAL WITH READINGS
IN THE MID TO UPPER 20S.
UNCERTAINTY HIGH BEYOND FRIDAY. MODEL CONSENSUS WAS USED FOR NOW
WHICH FEATURES PLETHORA OF SLIGHT CHANCE POPS. SEEMS THAT IDEA OF
SHORTWAVE LIFTING BACK ACROSS THE AREA AND BRINGING SOME LGT SNOW
IS OFF THE TABLE NOW AS THAT SYSTEM IS MUCH WEAKER AND FCST TO
REMAIN WELL TO THE SOUTH AND EAST OF CWA IF IT IS THERE AT ALL.
TEMPS SATURDAY IN THE TEENS AND LOWER 20S...WITH MORE NOTABLE
COOLING FOR SUNDAY WITH HIGHS IN THE LOWER TO MIDDLE TEENS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 708 AM EST MON FEB 17 2014
A LOW PRESSURE SYSTEM APPROACHING FROM THE PLAINS WILL SPREAD SNOW
WEST TO EAST ACROSS UPPER MICHIGAN TODAY. SNOW REACHING KIWD HAS
ALREADY DROPPED VSBY TO IFR THERE. EXPECT VSBYS AND/OR CIGS TO LOWER
TO IFR BY LATE MORNING AT KCMX. KSAW HAS SEEN CIGS LOWER TO LIFR IN
UPSLOPE SE FLOW. EXPECT VSBY TO LOWER TO IFR AROUND 18Z WITH ONSET OF
HEAVIER SNOW. COULD SEE SOME PERIODS OF LIFR VSBYS/CIGS AT SAW AND
CMX DURING THE AFTERNOON HOURS BEFORE ALL SITES IMPROVE TO MVFR
THIS EVENING AND TO VFR OVERNIGHT TONIGHT. IN ADDITION TO THE SNOW...A LOW
LEVEL JET OVER THE AREA WILL CONTRIBUTE TO LLWS THIS MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 522 AM EST MON FEB 17 2014
WINDS ARE FORECAST TO BE LESS THAN 30 KTS THIS WEEK. LOW PRESSURE
SYSTEM MOVING THROUGH LATE IN THE WEEK MAY RESULT IN STRONGER WINDS
THAN CURRENTLY FORECAST...MAINLY ON THURSDAY AFTERNOON AND THURSDAY
NIGHT. GALES MAY EVEN OCCUR. ONCE THIS LOW LIFTS TO THE NORTH...WEST
WINDS TO 30 KTS OR GALES APPEAR LIKELY ON FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 1 AM EST
TUESDAY FOR MIZ006-007-014-085.
WINTER WEATHER ADVISORY UNTIL 10 PM EST /9 PM CST/ THIS EVENING
FOR MIZ001-003>005-010>013-084.
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING
FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
524 AM EST MON FEB 17 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 522 AM EST MON FEB 17 2014
09Z WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN
ACROSS THE WEST AND CENTRAL CONUS WITH A MID/UPPER LEVEL TROUGH AND
SEVERAL EMBEDDED SHRTWVS EMERGING FROM THE NRN ROCKIES INTO THE WRN
PLAINS. WAA/ISENTROPIC LIFT AHEAD OF THIS SHORTWAVE TROUGH HAS
ALLOWED MID-HIGH CLOUDS TO SPREAD INTO THE FCST AREA FM THE WEST. AS
A RESULT...MUCH BELOW ZERO TEMPS FM LAST EVENING OVER CENTRAL AND
EASTERN COUNTIES OF THE CWA HAVE BEGUN TO MODERATE ABV ZERO AT MANY
LOCATIONS. SOME LIGHT SNOW IS ALSO NOW APPEARING ON RADAR AND SFC
OBS OVER NCNTRL WI AND FAR WRN UPR MI.
TODAY...MODELS IN GENERALLY GOOD AGREEMENT ON DEPICTION/MOVEMENT OF
MAIN SHORTWAVE NOW OVER WRN NEBRASKA TRACKING IT AND ASSOC SFC LOW
ESE THROUGH CNTRL ILLINOIS AND NRN INDIANA LATE AFTERNOON/EARLY
EVENING. NORTHERN SHORTWAVE OVER THE DAKOTAS APPEARS TO BECOME MORE
SHEARED OUT WITH TIME AS IT APPROACHES THE WRN LAKES LATE THIS
AFTERNOON. THIS IS REFLECTED IN 700-300 MB LAYER Q-VECTORS WHICH
SHOWS BEST CONV/LIFT GENERALLY PASSING SOUTH AND EAST OF THE FCST
AREA THIS AFTERNOON. ALSO A LIMITING FACTOR FOR HEAVY SNOW TODAY
OVER OUR AREA IS THE VERY DRY AIRMASS ALREADY IN PLACE AS NOTED ON
00Z GRB AND APX SOUNDINGS. CONSEQUENTLY..IT WILL TAKE LONGER FOR
COLUMN TO MOISTEN FM ISENTROPIC ASCENT AS THUS WILL LIKELY LIMIT
SNOW AMOUNTS SOMEWHAT. CONTINUED THE PREV FCST TREND OF GOING ON THE
LOWER END OF MODEL GUIDANCE FOR QPF AMOUNTS RANGING FROM .15 INCH
FAR EAST TO NEARLY .3 INCH NEAR MNM. USING COBB METHOD AVERAGED SLR
VALUES AROUND 17:1...TOTAL SNOW AMOUNTS FROM THIS SYSTEM WILL LIKELY
FALL INTO THE 3 TO 5 INCH RANGE ACROSS MUCH OF THE AREA...BUT FAR NE
CWA MAY STRUGGLE TO REACH MINIMAL ADVISORY CRITERIA OF 3 INCHES DUE
TO EFFECTS OF ATTENDANT DRY AIR DELAYING ARRIVAL OF PCPN UNTIL
MAINLY AFTERNOON. SSE WINDS ARE EXPECTED TO INCREASE AND GUST NEAR
25 MPH AT TIMES BY LATE MORNING/AFTERNOON WHICH MAY CONTRIBUTE TO
SOME BLSN BUT NOTHING OF GREAT SIGNIFICANCE. CONTINUED THE WINTER
WEATHER ADVISORIES ACROSS THE AREA BUT GIVEN POTENTIAL LIMITING
FACTORS MENTIONED ABOVE...LOWERED HIGH END OF ADVISORY RANGE TO 5
INCHES FOR WEST AND CENTRAL COUNTIES AND WENT GENERALLY 2 TO 4
INCHES FOR ERN COUNTIES.
TONIGHT...DEEP MOISTURE QUICKLY EXITS FROM WEST TO EAST THIS EVENING
AS SHORTWAVE DEPARTS SE OF REGION AND MODEL SOUNDINGS SHOW GOOD
MID-LVL SUBSIDENCE/DRYING LATE TONIGHT. WAA DEVELOPING FROM THE WEST
LATE TONIGHT AHEAD OF NEXT SHORTWAVE APPROACHING FM THE NRN PLAINS
MAY BRIEFLY ALLOW FOR SOME PATCHY FREEZING DRIZZLE TO FORM OVER ERN
COUNTIES IN UPSLOPE SOUTHERLY FLOW AS DGZ DRIES OUT...BUT STILL NOT
CONFIDENT ENOUGH TO INCLUDE IN FCST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 522 AM EST MON FEB 17 2014
ZONAL FLOW BRINGS MULTIPLE SHORTWAVES ACROSS THE REGION THROUGH THE
UPCOMING WEEK. STRONGEST WAVE BEYOND TODAY IS STILL ON TRACK TO
IMPACT GREAT LAKES THURSDAY AND THURSDAY NIGHT THOUGH CURRENT
INDICATIONS ARE THAT BIGGEST IMPACT WILL STAY MORE OVER THE OHIO
VALLEY AND LOWER GREAT LAKES. OPPORTUNITY TO FINALLY REACH ABOVE
FREEZING WFO MARQUETTE WILL BE THE MIDDLE OF THIS WEEK...THOUGH IT
IS NOT LOOKING AS SURE AS IT DID THE LAST COUPLE DAYS. WHATEVER WARM
UP OCCURS WILL NOT LAST AS IN WAKE OF THE LATE WEEK SYSTEM LARGER
SCALE TROUGHING WITH COLDER TEMPERATURES DEVELOPS OVER MUCH OF THE
CNTRL CONUS BY NEXT WEEKEND.
TUESDAY AND TUESDAY NIGHT...SHORTWAVE AND SFC LOW THAT ARE BRINGING
SNOW TO REGION TODAY HEAD OFF ACROSS NEW ENGLAND. WESTERLY FLOW
ALOFT WILL BRING ADDITIONAL SHORTWAVES FROM THE NORTHERN PLAINS TO
THE WESTERN GREAT LAKES BY TUESDAY AFTN. STRONGEST WAVE ON TUESDAY
CROSSES SOUTHERN MANITOBA INTO ONTARIO...WITH ASSOCIATED 995-1000MB
SFC LOW MOVING ACROSS ONTARIO IN THE AFTN...TO THE NORTH OF LK
SUPERIOR. SOUNDINGS SHOW PLENTY OF MID LEVEL MOISTURE TO H7 BUT ALSO
HAVE A LOT OF DRY AIR BLO THAT. ONLY EXCEPTION IS OVER EASTERN CWA
WHERE THERE MAY BE ENOUGH LOW-LEVEL MOISTURE TO RESULT IN SOME FREEZING
DRIZZLE IN THE MORNING. H85 FRONT LIKELY WILL BE VCNTY OF SOUTHERN
LK SUPERIOR SO KEPT SLIGHT CHANCES MAINLY OVER LK SUPERIOR AND IN THE
FAR NORTH CWA. WARMEST TEMPS OVER FAR WEST WHERE MAY BE SOME BKN
SUNSHINE TO START THE DAY. H925-H9 TEMPS STILL AROUND 0C SO WOULD NOT
TAKE MUCH MIXING TO PUNCH TEMPS INTO AT LEAST MID 30S. FARTHER TO THE
EAST...MORE CLOUDS AND SW WINDS OFF MAINLY ICE COVERED LK MICHIGAN
SHOULD KEEP TEMPS BLO FREEZING. GENERALLY QUIET TUESDAY NIGHT THOUGH
WILL HAVE TO WATCH WESTERN CWA LATE AS THERE MAY BE ENOUGH LOW-LEVEL
MOISTURE AND UPSLOPE IN WAKE OF SFC TROUGH WORKING THROUGH TO PRODUCE
LGT PRECIP. SOUNDINGS WOULD SUPPORT SOME RISK OF FREEZING DRIZZLE
WITH LIMITED MOISTURE IN DGZ...THAT IS IF THERE IS SUFFICIENT
MOISTURE IN THE LOW-LEVELS.
WEDNESDAY...EARLIER IT LOOKED AS THERE WOULD BE NW WINDS IN WAKE OF
TROUGH ON TUESDAY TO RESULT IN COOLING FOR THE NORTH OFF ICE COVERED
LK SUPERIOR. WINDS IN BLYR NOW MORE WRLY WHICH OPENS POSSIBILITY OF
WARMER TEMPERATURES OVER MUCH OF CWA...EXCEPT ALONG IMMEDIATED LK
SUPERIOR SHORE OVER WESTERN CWA AND ACROSS KEWEENAW PENINSULA. BIAS
CORRECTED GUIDANCE INDICATED MID 30S FOR MOST AREAS WITH EVEN TEMPS
AROUND 40 IN THE SCNTRL. USED THIS SOLN AS A BLEND INTO PREVIOUS
FORECAST WHICH RESULTED IN SOLID MID 30S FOR GOOD PART OF CWA. COULD
BE SOME LOW-LEVEL MOISTURE TO BEGIN THE DAY...BUT THIS SHOULD SCOUR
OUT BY AFTN. OVERALL A QUIET WEATHER DAY OUT AHEAD OF STRONGER
LOW-MID LEVEL TROUGHING DEVELOPING OVER THE CNTRL CONUS.
THURSDAY AND FRIDAY...FATE OF THE LATE WEEK SYSTEM IS STILL CLOUDED
WITH MUCH UNCERTAINTY AT THIS POINT. ECMWF AND GFS TRENDED BACK TO
MORE WRAPPED UP AND WETTER SYSTEM AS SOUTHERN BRANCH SHORTWAVE
DOMINATES AND ALLOWS THE LARGER SCALE SHORTWAVE TROUGH TO BECOME
MORE NEGATIVELY TILTED AS IT SWEEPS ACROSS UPPER GREAT LAKES.
RESULTING SFC LOW DEEPENS TO SUB 980MB LOW OVER UPPER LAKES BY
THURSDAY NIGHT. AS ALLUDED TO YDY...SHORTWAVES THAT HELP FORM THIS
SYSTEM ARE STILL AROUND THE ALLUTIANS AND MAYBE EVEN FARTHER WEST
THAN THAT OVER NORTHERN RUSSIA. SO...ALTHOUGH THE 00Z ECMWF SOLUTION
COULD OCCUR AS IT SHOWED SOMETHING SIMILAR TWO DAYS AGO...IT IS
ESSENTIALLY ONE OF MANY SOLNS THAT REPRESENT THE MODEL ENSEMBLE AT
THIS POINT. ONLY CHANGE THAT WAS MADE COMPARED TO CONSENSUS WAS TO
LINGER CHANCE POPS ON THURSDAY NIGHT IN CASE THE SLOWER/WRAPPED UP
IDEA IS CORRECT. ALSO BROUGHT CHANCE FOR RAIN FARTHER NORTH OVER
EASTERN CWA. SEEMS THAT IF THE WARMER IDEA IS RIGHT...FZRA COULD
ALSO BE AN ISSUE TOO DUE TO LIMITED LOW-LEVEL WARM AIR ADVECTION BLO
H85 OR MAYBE JUST FROM THE RAIN FREEZING ON SUB FREEZING ROAD
SURFACES DUE TO THE PERSISTENT CHILL THAT HAS BEEN WITH US SINCE
EARLY DECEMBER. EVEN THOUGH THE SPECIFICS WITH THIS SYSTEM ARE FAR
FROM CERTAIN AND WILL LIKELY CHANGE UNTIL LATER THIS WEEK...THINK IT
IS WORTH A HEADS UP MENTION IN THE HAZARDOUS WEATHER OUTLOOK.
PRIMARY ISSUE INTO FRIDAY WILL BE STRONGER WINDS CLOSER TO LK
SUPERIOR WITH SMALL CHANCES OF SNOW SHOWERS IN LINGERING CYCLONIC
MOIST FLOW ON BACKSIDE OF THE DEPARTING LOW PRESSURE SYSTEM. THE
WARM UP WILL BE OVER BUT TEMPS WILL BE AROUND NORMAL WITH READINGS
IN THE MID TO UPPER 20S.
UNCERTAINTY HIGH BEYOND FRIDAY. MODEL CONSENSUS WAS USED FOR NOW
WHICH FEATURES PLETHORA OF SLIGHT CHANCE POPS. SEEMS THAT IDEA OF
SHORTWAVE LIFTING BACK ACROSS THE AREA AND BRINGING SOME LGT SNOW
IS OFF THE TABLE NOW AS THAT SYSTEM IS MUCH WEAKER AND FCST TO
REMAIN WELL TO THE SOUTH AND EAST OF CWA IF IT IS THERE AT ALL.
TEMPS SATURDAY IN THE TEENS AND LOWER 20S...WITH MORE NOTABLE
COOLING FOR SUNDAY WITH HIGHS IN THE LOWER TO MIDDLE TEENS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1251 AM EST MON FEB 17 2014
A LOW PRESSURE SYSTEM OVER THE PLAINS WILL MOVE TOWARD THE
AREA...SPREADING SNOW INTO UPPER MICHIGAN ON MONDAY. EXPECT VFR
CONDITIONS TONIGHT TO RAPIDLY GIVE WAY TO IFR CONDITIONS MONDAY
MORNING AT IWD AND CMX...AND PERHAPS WAITING UNTIL LATE MORNING SAW.
COULD SEE SOME PERIODS OF LIFR VSBYS/CIGS AND SAW AND CMX DURING THE
AFTERNOON HOURS BEFORE ALL SITES IMPROVE TO MVFR MONDAY EVENING. IN
ADDITION TO THE SNOW...A LOW LEVEL JET WILL DEVELOP OVER THE AREA
LATE TONIGHT INTO MONDAY MORNING. THIS SHOULD ALLOW LLWS TO DEVELOP
LATE TONIGHT AND CONTINUE THROUGH THE MORNING HOURS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 522 AM EST MON FEB 17 2014
WINDS ARE FORECAST TO BE LESS THAN 30 KTS THIS WEEK. LOW PRESSURE
SYSTEM MOVING THROUGH LATE IN THE WEEK MAY RESULT IN STRONGER WINDS
THAN CURRENTLY FORECAST...MAINLY ON THURSDAY AFTERNOON AND THURSDAY
NIGHT. GALES MAY EVEN OCCUR. ONCE THIS LOW LIFTS TO THE NORTH...WEST
WINDS TO 30 KTS OR GALES APPEAR LIKELY ON FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 1 AM EST
TUESDAY FOR MIZ006-007-014-085.
WINTER WEATHER ADVISORY UNTIL 10 PM EST /9 PM CST/ THIS EVENING
FOR MIZ001-003>005-010>013-084.
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING
FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...MRD
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1252 AM EST MON FEB 17 2014
.UPDATE...
ISSUED AT 905 PM EST SUN FEB 16 2014
TEMPERATURES ARE CRASHING THIS EVENING...ALREADY -8F AT THE OFFICE
HERE IN NEGAUNEE TWP. ALTHOUGH HIGHER CLOUDS ARE MOVING INTO THE
AREA FROM THE WEST...IT WILL TAKE AWHILE FOR THEM TO REACH THE
EASTERN HALF OF THE FORECAST AREA. AS SUCH...LOWERED TEMPERATURES
ACROSS THE ENTIRE AREA. IN FACT...WOULD NOT BE SURPRISED TO SEE
TEMPS -20F ACROSS THE EAST TONIGHT. WITH THE CLOUDS MOVING INTO THE
WEST...TEMPS SHOULD LEVEL OUT THERE...BUT STILL CLOSE TO ZERO OR A
LITTLE BELOW.
OTHERWISE...LOTS OF RADAR RETURNS IN MN...BUT IT LOOKS LIKE MOST OF
IT IS VIRGA AS THERE ARE NOT MANY SFC REPORTS OF SNOW UNTIL YOU GET
MUCH CLOSER TO THE FRONT IN THE DAKOTAS. COULD SEE SOME LIGHT SNOW
TIED TO THE FIRST PUNCH OF WARM ADVECTION MOVING NORTHWARD LATE
TONIGHT...BUT THE THOUGHT IS THAT THE BEST SNOW WILL NOT MOVE INTO
THE WEST UNTIL AFT 12Z. AS SUCH...WILL LOWER POPS TONIGHT INTO EARLY
MON MORNING ESPECIALLY ACROSS THE CENTRAL PART OF THE FORECAST AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 418 PM EST SUN FEB 16 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MAINLY ZONAL PATTERN ACROSS
THE WEST AND CNTRL CONUS WITH A MID/UPPER LEVEL TROUGH AND SEVERAL
EMBEDDED SHRTWVS THROUGH THE NRN ROCKIES. LINGERING CONFLUENT FLOW
OVER NRN ONTARIO INTO THE NRN LAKES AND ASSOCIATED SFC ARCTIC HIGH
PRESSURE HAS BROUGHT MOSTLY CLEAR SKIES TO THE REGION. VIS LOOP
SHOWED MID/HIGH CLOUD SPREADING QUICKLY THROUGH MN WITH THE WAA
REGIME AHEAD OF LOW PRES OVER THE WRN PLAINS.
TONIGHT...CLEAR SKIES EARLY THIS EVENING SHOULD GIVE WAY TO
INCREASING CLOUDS OVERNIGHT...PER MDLS RH FCST AND SATELLITE TRENDS.
RADIATIONAL COOLING THIS EVENING WILL ALLOW TEMPS TO DROP QUICKLY
WITH GRADUALLY RISING TEMPS OVERNIGHT FROM WEST TO EAST. OVER THE
ERN CWA...WITH THE LONGER PERIOD OF CLEAR SKIES...TEMPS COULD DROP
TO AROUND -10F OR EVENING COLDER. OTHERWISE...LOWS IN THE ZERO TO
-5F RANGE ARE EXPECTED CENTRAL AND 0 TO 5F WEST.
MONDAY...THE MODELS WERE IN RELATIVELY GOOD AGREEMENT AS THE MID
LEVEL TROUGH MOVES THROUGH THE UPPER MS VALLEY AND GREAT LAKES. THE
STRONGER 700-300 MB QVECTOR CONV ASSOCIATED WITH THE THE SRN SHRTWV
WILL IS EXPECTED TO MOVE THROUGH SRN WI INTO SRN LOWER MI.
HOWEVER...THE WEAKER QG FORCING TO THE NORTH ALONG WITH 285K-290K
ISENTROPIC LIFT AHEAD OF THE TROUGH WITH 2G/KG AVAILABLE SHOULD ALSO
SUPPORT MODERATE SNOWFALL ACROSS UPPER MICHIGAN. WITH THE STRONGER
DYNAMICS TO THE SOUTH OF THE CWA...THE FCST LEANED MORE TOWARD THE
LOWER END OF CONSENSUS QPF VALUES...MAINLY IN THE 0.25 TO 0.35 INCH
RANGE...PER NAM AND REGIONAL GEM. UPWARD MOTION THE DGZ SUPPORTS SLR
VALUES IN THE 15/1 TO 20/1 RANGE GIVING OVERALL SNOWFALL AMOUNTS IN
THE 3 TO 6 INCH RANGE. ALTHOUGH SRLY WINDS WILL INCREASE AND BECOME
GUSTY AT TIMES...BLSN IS NOT EXPECTED TO BE A SIGNIFICANT PROBLEM. A
WINTER WEATHER ADVISORY WAS ISSUED TO COVER THE EXPECTED
CONDITIONS. THE BEST CHANCE TO REACH OR EXCEED THE 6 INCH WARNING
THRESHOLD WOULD BE OVER THE SRN CWA...BUT CONFIDENCE WAS NOT HIGH
ENOUGH TO POST A WINTER STORM WARNING.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 PM EST SUN FEB 16 2014
A SHORTWAVE TROUGH WILL BE OVER WRN UPPER MI AT 00Z TUE AND WILL
PUSH E OF THE CWA SHORTLY AFTER 06Z TUE. MOST OF THE SNOW FROM THIS
SYSTEM COMES PRIOR TO 00Z TUE...SO WILL LEAVE MOST OF THE DISCUSSION
OF THIS SYSTEM TO THE SHORT TERM FORECASTER. 12Z/16 GFS CONTINUES TO
APPEAR TOO FAST WITH THE SYSTEM...SO STUCK WITH NON-GFS SOLUTIONS
FOR POPS/QPF. MOST OF THE ADDITIONAL SNOW MON NIGHT FALLS PRIOR TO
06Z...WITH NO SNOW EXPECTED IN THE 00Z-06Z TIME PERIOD OVER FAR WRN
UPPER MI TO 2 INCHES OVER THE ERN CWA.
DEEP MOISTURE EXITS WITH THE SHORTWAVE LATE MON NIGHT WHILE MID/LOW
LEVEL TEMPS INCREASE AS THE MID LEVEL PORTION OF A WARM FRONT MOVES
IN FROM THE W. THIS TRAPS MOISTURE IN THE LOW LEVELS OVER THE ERN
CWA WITH DRY AIR ABOVE THE INVERSION...WHICH LEAVES THE DGZ DRY AND
SUB-INVERSION TEMPS NOT SUFFICIENT FOR ICE CRYSTAL FORMATION. THINK
THERE IS A POSSIBILITY OF FREEZING DRIZZLE OVER ERN UPPER MI FOR A
BRIEF PERIOD LATE MON NIGHT INTO TUE MORNING AS THE SFC PORTION OF
THE WARM FRONT APPROACHES. THE CENTRAL AND WRN CWA WILL NOT SEE AS
MUCH MOISTURE UNDER THE INVERSION...SO NOT AS WORRIED THERE.
HOWEVER...GIVEN LACK OF SIGNIFICANT TOPOGRAPHY FOR UPSLOPE WITH THE
SW WINDS OVER SCHOOLCRAFT AND LUCE COUNTIES...WILL NOT ADD FREEZING
DRIZZLE TO THE FORECAST AT THIS TIME.
THE REST OF TUE IS TRICKY...ESPECIALLY WITH TEMPERATURES POSSIBLY
APPROACHING FREEZING FOR THE FIRST TIME IN A WHILE. A THERMAL RIDGE
PASSES OVERHEAD AROUND MID DAY TUE WITH 850MB TEMPS AOA 0C IN MOST
LOCATIONS...WHICH IS FAVORABLE FOR WARMER TEMPS. NEGATIVES FOR THE
WARMER TEMPS ARE EASIER TO COME UP WITH...INCLUDING THE FACT THAT IT
HAS BEEN QUITE COLD LATELY SO THE SNOW PACK IS VERY COLD. WE WILL
HAVE FRESH SNOW FROM THE PREVIOUS EVENING THAT WILL HELP KEEP TEMPS
COLD AND SFC ALBEDO LOWER. ANY WARMING POTENTIAL FROM THE NORMAL
WARMER WATERS OF THE GREAT LAKES WILL BE REDUCED OR ELIMINATED DUE
TO ICE COVER. UNTIL THE WARM FRONT MOVES THROUGH...THERE SHOULD BE A
GOOD AMOUNT OF CLOUD COVER...WHICH WILL LIMIT WARMING. A COLD FRONT
MOVES INTO THE CWA LATE TUE AFTERNOON AND TUE EVENING...BRINGING
COLDER AIR AND MORE CLOUDS. IN FACT...BY 00Z WED...NWRN UPPER MI
SHOULD SEE 850MB TEMPS DOWN TO -4C. ANOTHER SIGNIFICANT NEGATIVE FOR
THE WARMER TEMPS IS THAT MODELS ARE SHOWING A COUPLE OF WEAK
SHORTWAVES MOVING ACROSS THE NRN CWA FROM EARLY TUE AFTERNOON
THROUGH TUE EVENING...WHICH WILL AT LEAST KEEP CLOUD COVER UP OVER
NRN UPPER MI AND LAKE SUPERIOR AND MAY EVEN BRING SOME MINOR LIGHT
SNOW /SINCE AREAS OF THE LOW AND MID LEVELS THAT WILL BE ABOVE 0C
WILL BE DRY WITH SUB-ZERO WET BULB TEMPS/. CONSIDERING ALL
THIS...TEMPS WILL BE VERY CONDITIONAL...WITH THE BEST CHANCES OF
SEEING ABOVE FREEZING TEMPS OVER SRN UPPER MI NEAR THE WI BORDER.
LEFT TEMPS SIMILAR ALONG THE WI BORDER...BUT LOWERED A COUPLE OF
DEGREES OVER NRN AREAS.
NO SIGNIFICANT PRECIP IS EXPECTED WED AND TEMPS WILL BE BELOW
FREEZING AS MODELS CONTINUE TO INDICATE 850MB TEMPS AOB -5C AT 18Z.
ANOTHER THERMAL RIDGE MOVES THROUGH WED NIGHT. A SHORTWAVE LOOKS TO
MOVE INTO THE REGION LATER THU INTO THU NIGHT...BRINGING COLDER AIR
FOR THE REST OF THU ALONG WITH INCREASED CLOUD COVER. AS FAR AS
PRECIP IS CONCERNED...THINGS ARE A LOT MORE UNCERTAIN AS MODELS DO
NOT HAVE GOOD CONTINUITY WITH THE EXACT LOCATION AND INTENSITY OF
THE SHORTWAVE. AT THIS TIME...IT DOES APPEAR THE BULK OF THE
SHORTWAVE ENERGY WILL GO N OF THE CWA...WITH POSSIBLY ADVISORY LEVEL
SNOWFALL OVER UPPER MI. AGAIN...UNCERTAINTY IS HIGH IN THE PRECIP
FORECAST FOR THIS TIME PERIOD.
THEN FOR FRI THROUGH NEXT SUN...IT APPEARS THAT UPPER TROUGHING WILL
DOMINATE MUCH OF THE CONUS...BRINGING A RETURN OF BELOW NORMAL
TEMPERATURES. WHILE THERE IS MORE CONFIDENCE IN THE COLDER
TEMPS...OVERALL CONFIDENCE IS LOW. USED GENERAL MODEL CONSENSUS FOR
THIS PERIOD OF THE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1251 AM EST MON FEB 17 2014
A LOW PRESSURE SYSTEM OVER THE PLAINS WILL MOVE TOWARD THE
AREA...SPREADING SNOW INTO UPPER MICHIGAN ON MONDAY. EXPECT VFR
CONDITIONS TONIGHT TO RAPIDLY GIVE WAY TO IFR CONDITIONS MONDAY
MORNING AT IWD AND CMX...AND PERHAPS WAITING UNTIL LATE MORNING SAW.
COULD SEE SOME PERIODS OF LIFR VSBYS/CIGS AND SAW AND CMX DURING THE
AFTERNOON HOURS BEFORE ALL SITES IMPROVE TO MVFR MONDAY EVENING. IN
ADDITION TO THE SNOW...A LOW LEVEL JET WILL DEVELOP OVER THE AREA
LATE TONIGHT INTO MONDAY MORNING. THIS SHOULD ALLOW LLWS TO DEVELOP
LATE TONIGHT AND CONTINUE THROUGH THE MORNING HOURS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 PM EST SUN FEB 16 2014
OVERALL...WINDS ARE FORECAST TO BE LESS THAN 25 KTS THROUGH THE
UPCOMING WEEK. SOUTHEAST WINDS TO 30 KTS OCCUR MONDAY AND MONDAY
EVENING OVER EASTERN AND NORTH CENTRAL LK SUPERIOR...BUT GALES ARE
NOT EXPECTED AS MAIN SFC LOW PRESSURE PASSES OVER CNTRL AND LOWER
GREAT LAKES. WINDS MAY TREND STRONGER LATE THIS WEEK AS ANOTHER LOW
PRESSURE SYSTEM IMPACTS THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 1 AM EST
TUESDAY FOR MIZ006-007-014-085.
WINTER WEATHER ADVISORY FROM 7 AM EST /6 AM CST/ THIS MORNING TO
10 PM EST /9 PM CST/ THIS EVENING FOR MIZ001-003>005-
010>013-084.
WINTER WEATHER ADVISORY FROM 5 AM EST /4 AM CST/ EARLY THIS
MORNING TO 7 PM EST /6 PM CST/ THIS EVENING FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...MRD
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...MRD
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
331 PM CST MON FEB 17 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 245 PM CST MON FEB 17 2014
UPPER TROUGH WORKING ACROSS THE AREA THIS AFTERNOON HAS GONE QUITE
NEGATIVE ON US...WHICH HAS RESULTED IN THE SNOW AND CLOUDS FILLING
BACK IN TO THE WEST. THE WRN EDGE OF THE SNOW IS FAIRLY SHARP AND IS
ASSOCIATED WITH A WARM FRONT AND SOME VERY MILD PACIFIC AIR...AS
EVIDENCED BY 50 DEGREE TEMPERATURES AS CLOSE AS SIOUX CITY...IA.
EVEN OUT IN WRN MN WHERE THE SKIES HAVE CLEARED OUT...TEMPERATURES
HAVE MANAGED TO PUSH UP INTO THE MID/UPPER 30S. THIS MILD AIRMASS
WILL BE WITH US THROUGH THE REST OF THE SHORT TERM. CONSIDERING MSP
HAS NOT HAD A DAY WITH AN AVERAGE TEMPERATURE ABOVE NORMAL SINCE JAN
24TH...I`M SURE SOME WARMER TEMPERATURES WILL BE WELL RECEIVED!
WITH GENERAL SLOWING OF THE SYSTEM...HAVE HAD TO SLOW DOWN EASTWARD
MOVEMENT OF CLEARING AND ENDING OF SNOW IN GRIDS. SNOW LIKELY WILL
NOT CLEAR WRN WISCONSIN UNTIL 00Z...BUT HAVE DECIDED TO NOT EXTEND
THE WARNING BEYOND 3 PM. THIS IS BECAUSE VISIBILITY RESTRICTIONS
HAVE MAINLY COME UP TO 2 OR MORE MILES...WHICH MEANS THE RATES HAVE
REALLY LET UP. AT THIS POINT...ANY REMAINING SNOWS WILL BE LIGHT
WITH ACCUMULATIONS UP TO AN INCH. THIS WILL BRING SNOW TOTALS IN
WISCONSIN UP TO AROUND 4 INCHES...WHICH COMBINED WITH THE LIGHTER
INTENSITY DOES NOT REALLY JUSTIFY KEEPING THE WARNING GOING...EVEN
IF LIGHT SNOW BLEEDS TO 00Z.
FOR HIGHS TOMORROW...ONLY GUIDANCE THAT WAS AVOIDED AT THIS POINT
WAS THE SREF/NAM/GFS. THIS IS BECAUSE THESE MODELS CONTINUE TO OVER
COOL THE BOUNDARY LAYER DUE TO THE SNOW COVER. INSTEAD...CONTINUED
TO TREND THINGS TOWARD THE WARMER NCEP MOS GUIDANCE AND NON-NCEP RAW
MODEL OUTPUT. THIS CONTINUES THE MENTION OF UPPER 30S TO LOWER
40S...THOUGH WITH THE EDGE OF THE SNOWPACK SO CLOSE...WOULD NOT BE
SURPRISED IF THESE TEMPERATURES ENDED UP BEING ABOUT 5 DEGREES TOO
COLD...ESPECIALLY OUT SW OF THE MN RIVER.
IF A HIGH OF 40 CAN BE ACHIEVED...IT WOULD BE THE FIRST TIME SINCE
JANUARY 12TH AT MSP AND EAU CLAIRE AND DECEMBER 27TH FOR ST. CLOUD.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 245 PM CST MON FEB 17 2014
LONG TERM TRENDS CONTINUE TO INDICATE A WARM PERIOD INTO MIDWEEK
BEFORE THE NEXT SIGNIFICANT TROUGH DROPS INTO THE MIDSECTION OF
THE COUNTRY...WITH CYCLOGENESIS OVER KANSAS/OKLAHOMA REGION...
LIFTING NORTHEAST AND OCCLUDING OVER EASTERN WISCONSIN BY THURSDAY
EVENING. FOLLOWING THIS WILL BE ANOTHER SHOT OF COLD AIR THROUGH
THE REMAINDER OF THE WEEK AND INTO NEXT WEEK AS THE EASTERN CONUS
TROUGH REDEVELOPS.
THE PRESENT FORECAST TRACK OF THE NEXT SURFACE LOW WILL SPREAD A
DECENT SWATH OF SNOW BACK INTO OUR CWA THURSDAY. THE 12Z DETERMINISTIC
GFS AND ECMWF BOTH INDICATE THE SURFACE LOW TRACKING OVER EASTERN
WISCONSIN THURSDAY. WEST CENTRAL WISCONSIN HAS THE BEST SHOT OF 4
INCHES OR MORE OF SNOW WITH THIS SYSTEM. WE HAVE EXTENDED THE
LIKELY POPS EXTEND INTO EAST CENTRAL INTO SOUTH CENTRAL
MINNESOTA...WITH LESSER SNOW AMOUNTS AMOUNTS EXPECTED HERE. PTYPE
ISSUES RETURN AS WARMER AIR IS LIFTED NORTH AND EAST OF THE
INITIAL TROUGH FOR WEDNESDAY. APPEARS TO BE A RAIN...SLEET...SNOW
MIX POSSIBLE DEVELOPING LATER WEDNESDAY NIGHT OVER THE REGION. DID
INCLUDE THIS MIXED PRECIPITATION POSSIBILITY INTO EARLY THURSDAY.
AS THE LOW SHIFTS EAST THURSDAY...COLDER AIR WILL DROP INTO THE
AREA AND TRANSITION ANY MIX OVER TO SNOW.
COOLER TEMPERATURES FOLLOW THIS SYSTEM WITH HIGHS DROPPING BACK
INTO THE TEENS THROUGH THE WEEKEND. WILL COULD SEE SOME MORE BELOW
ZERO LOWS ACROSS MUCH OF THE AREA BY EARLY NEXT WEEK. THE 12Z
ECMWF DROPS A LARGE ARCTIC 1042MB HIGH SOUTHEAST OVER THE EASTERN
CONUS LATE IN THE WEEKEND. THE 12Z ECMWF SHOWS H85 TEMPERATURES
DROPPING BACK TO MINUS 32C OVER THE GREAT LAKES BY NEXT TUESDAY
NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1148 AM CST MON FEB 17 2014
MAIN CHANGE WITH THESE TAFS WAS TO DELAY THE RETURN OF VFR
CONDITIONS THIS AFTERNOON/EVENING AS THE SYSTEM MOVING THROUGH IS
BEGINNING TO TAKE ON MORE OF A NORTHWESTWARD TILT...WHICH HAS
ALLOWED EVERYTHING TO SLOW DOWN A BIT. BASED TIMING OF THE RETURN
TO VFR ON THE RAP...THOUGH TIMING ERRORS OF ABOUT +/- 1 HOUR CAN
BE EXPECTED. TONIGHT INTO TUESDAY MORNING...NEXT TROUGH MOVES
THROUGH WHICH WILL BRING NOTHING MORE THAN INCREASED MID LEVEL
CLOUDS. BESIDE THE CLOUDS THIS TROUGH WILL LEAD TO A DECENT AMOUNT
IN TURNING WITH WINDS...THOUGH MODEL AGREEMENT ON WIND DIRECTION
IS GOOD.
KMSP...HRRR HAS HAD A GOOD HANDEL ON THE BACK EDGE OF THE SNOW
THIS MORNING...THOUGH RADAR CURRENTLY SHOWS REFLECTIVITY STARTING
TO FILL BACK IN TO OUR WEST...SO WE MAY NOT COMPLETELY RID THE AIR
OF SNOWFLAKES UNTIL THE LOWER CLOUDS CLEAR OUT. CONFIDENCE LOWER
ON GOING BACK TO VFR...BUT BASED ON CURRENT TRENDS...THE SLOWER
PLAY OF THE RAP IS PROBABLY A GOOD START. CONFIDENCE HIGH IN
REMAINDER OF TAF FOR TONIGHT/TUESDAY.
/OUTLOOK FOR KMSP/
WED...VFR. WIND WSW EARLY...BCMG SSE 5-15 KT.
THU...MVFR OR LOWER WITH SN LIKELY. WIND WNW 10-15KT.
FRI...VFR. WINDS NW 5-10KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...DWE
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1214 PM CST MON FEB 17 2014
.UPDATE...
ISSUED AT 1148 AM CST MON FEB 17 2014
SNOW IS BEGINNING TO WIND DOWN ACROSS MN AND MOVE INTO WI...THOUGH
RATES HAVE STARTED TO COME DOWN AS EVIDENCED BY THE LACK OF
OBSERVATIONS WITH VISIBILITIES UNDER 1SM. THOUGH SNOW IS MOVING
OUT A BIT SLOWER...NO EXTENSIONS IN TIME WITH THE WARNING ARE
PLANNED AS THE BRUNT OF THE ACCUMULATING SNOWS WILL BE DOWN BY 18Z
IN MN AND 20Z IN WI.
18Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CST MON FEB 17 2014
ONLY MINOR TWEAKS WERE MADE TO THE SHORT TERM PERIOD OF THE
FORECAST. THE SNOW EVENT IS COMMENCING ACROSS CENTRAL AND SOUTH
CENTRAL MN...DRIVEN BY A HEALTHY MID/UPPER TROUGH EJECTING FROM
THE NORTHERN PLAINS TOWARD THE GREAT LAKES. WHILE THE DURATION OF
THE FORCING AND ATTENDANT SNOWFALL WILL BE RATHER SHORT /3-4 HOURS/...THE
INTENSE NATURE OF SAID FORCING SHOULD SUPPLY HOURLY ACCUMULATIONS
IN THE 1-1.5 INCH RANGE...KEEPING SNOWFALL TOTALS IN CHECK WITH
PRIOR FORECASTS /GENERALLY 3-7 INCHES ACROSS THE CWA/. WINDS HAVE
BEEN A BIT STRONGER THAN PREVIOUSLY EXPECTED...SO HAVE HIT THE
MENTION OF BLOWING SNOW A BIT HARDER. SNOW TAPERS FROM WEST TO
EAST DURING THE LATE MORNING AND AFTERNOON...WITH MOST LOCATIONS
SNOWFALL-FREE BY 00Z TUESDAY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 410 AM CST MON FEB 17 2014
MILD WX WILL OCCUR IN THE WAKE OF TODAY/S SYSTEM AS MORE PACIFIC AIR
RIDES OVER THE ROCKIES AND INTO THE UPPER MIDWEST. 30S AND A FEW 40S
WILL LIKELY OCCUR ACROSS THE AREA TUE/WED. ONLY MINOR DIFFERENCES IN
SFC TEMPS FROM PREVIOUS FORECAST. THIS IS BASED ON MODELS
CORRELATION TO SNOW DEPTH AND AMT OF SUNLIGHT.
THERE REMAINS SOME UNCERTAINTY FOR WED NIGHT/THURSDAY SYSTEM WHICH
TAKES THE SFC LOW A FEW HUNDRED MILES TO THE NW FROM PREVIOUS MODEL
RUNS. THIS IS BASED ON THE SLOWER MOVEMENT OF THE LONG WAVE TROUGH
ACROSS THE ROCKIES AND A STRONGER JET STREAM ACROSS THE CENTRAL U.S.
THIS WILL MAKE FOR A POSSIBLE SNOW STORM ALONG THE N/NW SIDE OF THE
SFC LOW TRACK...BUT ALL THE RIGHT ELEMENTS MUST COME TOGETHER. AT
THIS TIME...BASED ON THICKNESS VALUES...TIMING AND STRENGTH OF THE
UPPER JET...WILL CONTINUE WITH A CHANCE OF A MIXTURE OF FREEZING
RAIN/RAIN OR SNOW BEFORE WE GET A BETTER IDEA ONCE IT MOVES INTO THE
ROCKIES BY TUE.
THE FORECAST FOR THE UPCOMING WEEKEND REMAINS COLD AS PREVIOUS
FORECAST INDICATED. ONCE THE PATTERN CHGS WITH A BROAD LONG WAVE
TROUGH REESTABLISHES ACROSS THE CENTRAL/EASTERN U.S....THE ARCTIC
AIR FROM CANADA WILL ONCE AGAIN COMMENCE OVER OUR REGION. THE COLD
PATTERN LOOKS TO HOLD AT LEAST THROUGH EARLY NEXT WEEK. NO MAJOR
STORM SYSTEMS EXPECTED ONCE THE WED/THU SYSTEM MOVES THROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1148 AM CST MON FEB 17 2014
MAIN CHANGE WITH THESE TAFS WAS TO DELAY THE RETURN OF VFR
CONDITIONS THIS AFTERNOON/EVENING AS THE SYSTEM MOVING THROUGH IS
BEGINNING TO TAKE ON MORE OF A NORTHWESTWARD TILT...WHICH HAS
ALLOWED EVERYTHING TO SLOW DOWN A BIT. BASED TIMING OF THE RETURN
TO VFR ON THE RAP...THOUGH TIMING ERRORS OF ABOUT +/- 1 HOUR CAN
BE EXPECTED. TONIGHT INTO TUESDAY MORNING...NEXT TROUGH MOVES
THROUGH WHICH WILL BRING NOTHING MORE THAN INCREASED MID LEVEL
CLOUDS. BESIDE THE CLOUDS THIS TROUGH WILL LEAD TO A DECENT AMOUNT
IN TURNING WITH WINDS...THOUGH MODEL AGREEMENT ON WIND DIRECTION
IS GOOD.
KMSP...HRRR HAS HAD A GOOD HANDEL ON THE BACK EDGE OF THE SNOW
THIS MORNING...THOUGH RADAR CURRENTLY SHOWS REFLECTIVITY STARTING
TO FILL BACK IN TO OUR WEST...SO WE MAY NOT COMPLETELY RID THE AIR
OF SNOWFLAKES UNTIL THE LOWER CLOUDS CLEAR OUT. CONFIDENCE LOWER
ON GOING BACK TO VFR...BUT BASED ON CURRENT TRENDS...THE SLOWER
PLAY OF THE RAP IS PROBABLY A GOOD START. CONFIDENCE HIGH IN
REMAINDER OF TAF FOR TONIGHT/TUESDAY.
/OUTLOOK FOR KMSP/
WED...VFR. WIND WSW EARLY...BCMG SSE 5-15 KT.
THU...MVFR OR LOWER WITH SN LIKELY. WIND WNW 10-15KT.
FRI...VFR. WINDS NW 5-10KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL NOON CST TODAY FOR MNZ051>053-059>063-
068>070-077-078.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ043>045-050-
085-093.
WI...WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR
WIZ014>016-023>028.
&&
$$
UPDATE...MPG
SHORT TERM...LS
LONG TERM...JLT
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
955 AM CST MON FEB 17 2014
.UPDATE...
ISSUED AT 926 AM CST MON FEB 17 2014
LATEST MSAS SHOWS ELONGATED SFC PRESS TROUGH EXTENDING FROM SCTRL
MANITOBA ACROSS NWRN MN INTO WRN IOWA. SFC PRESS FALLS CONTINUE
AHEAD OF THE FEATURE AS A RESULT OF THE WARM AIR ADVECTION. LATEST
SPC MESO SHOWS RELATIVELY WEAK 85H FRONTOGENESIS AS CORE OF
STRONGEST LLJ HAS TRANSLATED INTO ERN WISC ZONES. BUFKIT
TIME/HEIGHT XSECTS OF DGZ/OMEGA PATTERN INDICATES MAJORITY OF OMEGA
IS OCCURRING JUST ABOVE MOST FAVORED DGZ. PLAN VIEW OF DGZ/OMEGA
FROM NAM12 SUGGESTS SNOWFALL RATES OF 1/2 TO 1 INCH/HR WILL OCCUR
OVER MOST OF CWA THROUGH 18Z. AFTER THAT TIME...OMEGA DECREASES
CONSIDERABLY AND SATURATION IN ICE NUCLEATION LAYER DECREASES
DRAMATICALLY FROM WEST TO EAST. THIS IS SUPPORTED ALSO IN THE
LATEST NARRE-TL PROBABILISTIC REFLECTIVITY PRODUCTS. NOTED A FEW
METAR REPORTS WITH UP IN PAST 2 HRS JUST WEST OF CWA ON BACK EDGE
OF FAVORED ICE NUCLEATION LAYER. MAY SEE SOME PATCHY FZDZ AT BACK
EDGE OF PRECIP THIS AFTN BUT WILL LEAVE OUT FOR NOW. CURRENT
EXPIRATION OF ADVISORY/WARNING LOOKS GOOD. TOTAL AMOUNTS MAY BE
LESS THAN 6" FOR MOST OF TWIN PORTS VICINITY WITH HIGHEST TOTALS
ALONG NORTH SHORE AS ALREADY MENTIONED IN VARIOUS PRODUCTS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 304 AM CST MON FEB 17 2014
FORECAST CONCERNS ARE ON HEADLINES. SFC LOW CENTER AT 08Z WAS
LOCATED IN CENTRAL SASKATCHEWAN WITH A WARM FRONT SEWD INTO THE
EASTERN DAKOTAS. LIGHT SNOW HAS FORMED AHEAD OF THIS SYSTEM IN AN
AREA OF 700MB FGEN DRAPED OVER THE FA FROM THE ARROWHEAD INTO NW WI.
THIS IS DEPICTED WELL ON RADAR WITH FIRST BAND OF MODERATE
SNOW...WITH VSBYS DOWN TO A HALF MILE...LIFTING NEWD INTO THE
ARROWHEAD AND NW WI AT 0830Z. AFTER THIS INITIAL BAND...THERE
APPEARS TO BE A BREAK IN THE ACTION WITH NO SNOW FOR A FEW HOURS AS
THE 700MB FGEN MOVES OUT OF THE AREA. NEXT BAND OF FGEN IS DUE TO
ARRIVE IN THE FA BY 12Z AT 850MB. THIS IS ASSOCIATED WITH THE LARGE
BATCH OF SNOW IN SE SD AT 0830Z. EXPECT SNOW FALL RATES TO APPROACH
ONE INCH PER HOUR UNTIL AROUND 15Z. SNOW AMOUNTS SHOULD RANGE FROM 3
TO 4 INCHES BETWEEN 12Z AND 18Z MAINLY ALONG AND E OF HIGHWAY
53...AND ALONG THE I35 CORRIDOR FROM DULUTH TO PINE CITY. 1 TO 3
INCHES TO THE W OF HIGHWAY 53. THE SNOW WILL PERSIST UNTIL 21Z AND
THEN START TO DIMINISH FROM W TO E AS THE WARM FRONT MOVES THROUGH
MUCH OF THE AREA AND REACHES THE TIP OF THE ARROWHEAD SEWD TO THE
EASTERN EDGE OF THE FA BY 00Z TUESDAY. BEHIND THE FRONT IS DRIER AND
WARMER AIR. HAVE LEFT THE HEADLINES AS IS...BUT DID EXTEND THE
WARNING OVER THE EASTERN WI FA UNTIL 00Z WITH FROPA AND TO MATCH
NEIGHBORING OFFICES.
THE SNOW WILL CONTINUE TO DIMINISH FROM 00Z TO 03Z AS THE BEST
FORCING HAS MOVED E OF THE FA ALONG WITH THE WARM FRONT. ONLY
EXPECTING AN ADDITIONAL TENTH OF AN INCH OF SNOW DURING THIS TIME.
AFTER 03Z...HAVE REMOVED POPS UNTIL 08Z WHEN A MID LEVEL SHORT WAVE
CLIPS THE INTERNATIONAL BORDER. SOME FGEN IS NOTED AT 925MB...BUT
HAVE SMALL/LOW POPS AS MOISTURE WILL BE LACKING AND PCPN IS ONLY
SUPPORTED BY THE GFS AND ECMWF. NAM/GEM/SREF/UKMET AND THE SHORT
TERM HIRES MODELS ARE DRY. HAVE REMOVED THE MENTION OF -FZDZ WHICH
IS NO LONGER SUPPORTED BY ANY OF THE MODELS.
A WEAK COLD FRONT IS DUE TO MOVE THROUGH THE FA ON TUESDAY. MOISTURE
IS LIMITED...BUT DO HAVE SOME POPS ACROSS THE FAR N DUE TO ITS
PROXIMITY TO THE SFC LOW CENTER MOVING THROUGH SOUTH CENTRAL CANADA.
AMOUNTS WILL BE LIGHT. EVEN THOUGH SFC MAX TEMPS WILL BE IN THE
30S...THERMAL PROFILES SUGGEST THE PTYPE WILL BE ALL SNOW.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 304 AM CST MON FEB 17 2014
A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE NORTHLAND TUESDAY NIGHT
PASSING THROUGH ON WEDNESDAY. MOST AREAS WILL BE DRY AND MILD...WITH
HIGHS WEDNESDAY IN THE THIRTIES.
ANOTHER SHORTWAVE WILL IMPACT THE REGION LATE WEDNESDAY NIGHT INTO
THURSDAY NIGHT...AND BRING A CHANCE FOR SNOW. THE GFS/ECMWF ARE IN
DECENT AGREEMENT WEDNESDAY NIGHT HAVING TWO SEPARATE WAVES WITH A
SURFACE LOW ALONG OR JUST NORTH OF THE INTERNATIONAL BORDER WITH A
SECOND LOW IN THE CENTRAL/SOUTHERN PLAINS REGION. THE ECMWF REALLY
DEEPENS THE SOUTHERN LOW AS IT MOVES NORTHEAST INTO SOUTHEAST
WI/SOUTHERN LAKE MICHIGAN BY 00Z FRI...AND CONTINUES TO DEEPEN THE
LOW ANOTHER 16MB OVER 12 HOURS THURSDAY NIGHT AS IT MOVES TO EASTERN
LAKE SUPERIOR. OTHER THAN THE STRENGTH OF THE LOW...THE GFS/ECMWF
REMAIN IN DECENT AGREEMENT THROUGH 12Z FRI...WITH THE GFS FURTHER
EAST WITH THE LOW AT 12Z FRI. WE BACKED OFF ON POPS A BIT WEDNESDAY
NIGHT...AND INCREASED SOME THURSDAY INTO THURSDAY NIGHT...ESPECIALLY
OVER EASTERN AREAS. THOSE WITH TRAVEL PLANS THURSDAY-THURSDAY NIGHT
SHOULD MONITOR THE FORECAST CLOSELY AS THIS SYSTEM IS QUITE STRONG
AND A TRACK FURTHER NORTH AND WEST COULD BRING SIGNIFICANTLY HIGHER
SNOWFALL INTO THE NORTHLAND.
THIS LOW WILL ALSO USHER IN COLDER AIR INTO THE REGION THURSDAY
NIGHT AND BEYOND. THURSDAY WILL REMAIN IN THE THIRTIES...BUT WILL
DROP TO THE TEENS TO LOWER TWENTIES BY FRIDAY...THEN TO 5 TO 15 BY
SUNDAY.
THE WEEKEND LOOKS TO BE RELATIVELY QUIET AT THIS TIME...WITH PERHAPS
SOME LIGHT SNOW OR FLURRIES OVER THE SOUTHERN HALF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 539 AM CST MON FEB 17 2014
RADAR SHOWED SNOW WAS EXPANDING ACROSS THE REGION...AND WIDESPREAD
IFR/MVFR CONDITIONS WILL OCCUR THROUGH MUCH OF THE DAY. WE
FOLLOWED CLOSE TO THE RAP IN DIMINISHING THE LOWER CEILINGS TODAY
AND HELD ONTO RESTRICTED VSBYS LONGER THAN THE MODELS WOULD
SUGGEST. HEAVIEST SNOW WILL OCCUR THROUGH NOON...AND LAST LONGER
OVER THE ARROWHEAD AND OVER NORTH CENTRAL WISCONSIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 26 17 35 15 / 100 10 10 10
INL 27 17 33 12 / 100 20 30 10
BRD 33 19 37 13 / 100 0 0 0
HYR 27 16 37 13 / 100 10 0 10
ASX 27 16 37 17 / 100 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR MNZ012-020-
021.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ010-018-025-
026-033>036.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR MNZ037-
038.
WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR MNZ011-
019.
WI...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR WIZ002>004-
008-009.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR WIZ001-
006-007.
LS...NONE.
&&
$$
UPDATE...CANNON
SHORT TERM...GSF
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
539 AM CST MON FEB 17 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 304 AM CST MON FEB 17 2014
FORECAST CONCERNS ARE ON HEADLINES. SFC LOW CENTER AT 08Z WAS
LOCATED IN CENTRAL SASKATCHEWAN WITH A WARM FRONT SEWD INTO THE
EASTERN DAKOTAS. LIGHT SNOW HAS FORMED AHEAD OF THIS SYSTEM IN AN
AREA OF 700MB FGEN DRAPED OVER THE FA FROM THE ARROWHEAD INTO NW WI.
THIS IS DEPICTED WELL ON RADAR WITH FIRST BAND OF MODERATE
SNOW...WITH VSBYS DOWN TO A HALF MILE...LIFTING NEWD INTO THE
ARROWHEAD AND NW WI AT 0830Z. AFTER THIS INITIAL BAND...THERE
APPEARS TO BE A BREAK IN THE ACTION WITH NO SNOW FOR A FEW HOURS AS
THE 700MB FGEN MOVES OUT OF THE AREA. NEXT BAND OF FGEN IS DUE TO
ARRIVE IN THE FA BY 12Z AT 850MB. THIS IS ASSOCIATED WITH THE LARGE
BATCH OF SNOW IN SE SD AT 0830Z. EXPECT SNOW FALL RATES TO APPROACH
ONE INCH PER HOUR UNTIL AROUND 15Z. SNOW AMOUNTS SHOULD RANGE FROM 3
TO 4 INCHES BETWEEN 12Z AND 18Z MAINLY ALONG AND E OF HIGHWAY
53...AND ALONG THE I35 CORRIDOR FROM DULUTH TO PINE CITY. 1 TO 3
INCHES TO THE W OF HIGHWAY 53. THE SNOW WILL PERSIST UNTIL 21Z AND
THEN START TO DIMINISH FROM W TO E AS THE WARM FRONT MOVES THROUGH
MUCH OF THE AREA AND REACHES THE TIP OF THE ARROWHEAD SEWD TO THE
EASTERN EDGE OF THE FA BY 00Z TUESDAY. BEHIND THE FRONT IS DRIER AND
WARMER AIR. HAVE LEFT THE HEADLINES AS IS...BUT DID EXTEND THE
WARNING OVER THE EASTERN WI FA UNTIL 00Z WITH FROPA AND TO MATCH
NEIGHBORING OFFICES.
THE SNOW WILL CONTINUE TO DIMINISH FROM 00Z TO 03Z AS THE BEST
FORCING HAS MOVED E OF THE FA ALONG WITH THE WARM FRONT. ONLY
EXPECTING AN ADDITIONAL TENTH OF AN INCH OF SNOW DURING THIS TIME.
AFTER 03Z...HAVE REMOVED POPS UNTIL 08Z WHEN A MID LEVEL SHORT WAVE
CLIPS THE INTERNATIONAL BORDER. SOME FGEN IS NOTED AT 925MB...BUT
HAVE SMALL/LOW POPS AS MOISTURE WILL BE LACKING AND PCPN IS ONLY
SUPPORTED BY THE GFS AND ECMWF. NAM/GEM/SREF/UKMET AND THE SHORT
TERM HIRES MODELS ARE DRY. HAVE REMOVED THE MENTION OF -FZDZ WHICH
IS NO LONGER SUPPORTED BY ANY OF THE MODELS.
A WEAK COLD FRONT IS DUE TO MOVE THROUGH THE FA ON TUESDAY. MOISTURE
IS LIMITED...BUT DO HAVE SOME POPS ACROSS THE FAR N DUE TO ITS
PROXIMITY TO THE SFC LOW CENTER MOVING THROUGH SOUTH CENTRAL CANADA.
AMOUNTS WILL BE LIGHT. EVEN THOUGH SFC MAX TEMPS WILL BE IN THE
30S...THERMAL PROFILES SUGGEST THE PTYPE WILL BE ALL SNOW.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 304 AM CST MON FEB 17 2014
A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE NORTHLAND TUESDAY NIGHT
PASSING THROUGH ON WEDNESDAY. MOST AREAS WILL BE DRY AND MILD...WITH
HIGHS WEDNESDAY IN THE THIRTIES.
ANOTHER SHORTWAVE WILL IMPACT THE REGION LATE WEDNESDAY NIGHT INTO
THURSDAY NIGHT...AND BRING A CHANCE FOR SNOW. THE GFS/ECMWF ARE IN
DECENT AGREEMENT WEDNESDAY NIGHT HAVING TWO SEPARATE WAVES WITH A
SURFACE LOW ALONG OR JUST NORTH OF THE INTERNATIONAL BORDER WITH A
SECOND LOW IN THE CENTRAL/SOUTHERN PLAINS REGION. THE ECMWF REALLY
DEEPENS THE SOUTHERN LOW AS IT MOVES NORTHEAST INTO SOUTHEAST
WI/SOUTHERN LAKE MICHIGAN BY 00Z FRI...AND CONTINUES TO DEEPEN THE
LOW ANOTHER 16MB OVER 12 HOURS THURSDAY NIGHT AS IT MOVES TO EASTERN
LAKE SUPERIOR. OTHER THAN THE STRENGTH OF THE LOW...THE GFS/ECMWF
REMAIN IN DECENT AGREEMENT THROUGH 12Z FRI...WITH THE GFS FURTHER
EAST WITH THE LOW AT 12Z FRI. WE BACKED OFF ON POPS A BIT WEDNESDAY
NIGHT...AND INCREASED SOME THURSDAY INTO THURSDAY NIGHT...ESPECIALLY
OVER EASTERN AREAS. THOSE WITH TRAVEL PLANS THURSDAY-THURSDAY NIGHT
SHOULD MONITOR THE FORECAST CLOSELY AS THIS SYSTEM IS QUITE STRONG
AND A TRACK FURTHER NORTH AND WEST COULD BRING SIGNIFICANTLY HIGHER
SNOWFALL INTO THE NORTHLAND.
THIS LOW WILL ALSO USHER IN COLDER AIR INTO THE REGION THURSDAY
NIGHT AND BEYOND. THURSDAY WILL REMAIN IN THE THIRTIES...BUT WILL
DROP TO THE TEENS TO LOWER TWENTIES BY FRIDAY...THEN TO 5 TO 15 BY
SUNDAY.
THE WEEKEND LOOKS TO BE RELATIVELY QUIET AT THIS TIME...WITH PERHAPS
SOME LIGHT SNOW OR FLURRIES OVER THE SOUTHERN HALF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 539 AM CST MON FEB 17 2014
RADAR SHOWED SNOW WAS EXPANDING ACROSS THE REGION...AND WIDESPREAD
IFR/MVFR CONDITIONS WILL OCCUR THROUGH MUCH OF THE DAY. WE
FOLLOWED CLOSE TO THE RAP IN DIMINISHING THE LOWER CEILINGS TODAY
AND HELD ONTO RESTRICTED VSBYS LONGER THAN THE MODELS WOULD
SUGGEST. HEAVIEST SNOW WILL OCCUR THROUGH NOON...AND LAST LONGER
OVER THE ARROWHEAD AND OVER NORTH CENTRAL WISCONSIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 26 17 35 15 / 100 10 10 10
INL 27 17 33 12 / 100 20 30 10
BRD 33 19 37 13 / 100 0 0 0
HYR 27 16 37 13 / 100 10 0 10
ASX 27 16 37 17 / 100 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR MNZ012-020-
021.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR MNZ010-018-025-
026-033>036.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR MNZ037-
038.
WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR MNZ011-
019.
WI...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR WIZ002>004-
008-009.
WINTER STORM WARNING UNTIL 3 PM CST THIS AFTERNOON FOR WIZ001-
006-007.
LS...NONE.
&&
$$
SHORT TERM...GSF
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1142 PM CST SUN FEB 16 2014
.UPDATE...
ISSUED AT 710 PM CST SUN FEB 16 2014
GUSTY EAST WINDS TO 25 KT HAVE PRODUCED ENOUGH LIFT TO KICK OFF
LOW CLOUDS AND FLURRIES ALONG THE NORTH SHORE AND WESTERN TIP OF
LAKE SUPERIOR THIS EVENING. THIS EVENING SNOW WILL BE VERY LIGHT
WITH NO ACCUMULATION. THE MAIN PERIOD OF ACCUMULATING SNOW WILL
AROUND AROUND MIDNIGHT IN THE TWIN PORTS.
HAVE INCREASED WINDS OVERNIGHT BASED ON LATEST NAM BUFR SOUNDINGS
AND 23Z RUN OF HRRR SHOWING GUSTY SE WINDS AHEAD OF THE TROUGH.
THE STRONGEST WINDS AND GUSTS TO 25 KT WILL BE FOUND ACROSS THE
BRD LAKES REGION..EAST OVER THE ST CROIX RIVER VALLEY.
DUE TO THE COMBO OF GUSTY WINDS AND FALLING SNOW...HAVE ALSO
INTRODUCED AREAS OF BLOWING SNOW TO THE FCST.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 301 PM CST SUN FEB 16 2014
AT 300PM/2100Z...SURFACE HIGH PRESSURE WAS CENTERED OVER ONTARIO
WITH ITS RIDGE AXIS STRETCHING SOUTH THROUGH THE NORTHLAND. THIS
WAS PROVIDING THE NORTHLAND SUNNY TO MOSTLY SUNNY SKIES.
HOWEVER...THERE WAS INCREASING CLOUD COVER WEST OF THE NORTHLAND
AND ACROSS THE NORTHERN PLAINS AHEAD OF AN APPROACHING TROUGH/WARM
FRONT STRETCHING FROM SOUTHERN ALBERTA AND THROUGH THE NORTHERN
HIGH PLAINS IN EASTERN MONTANA AND WYOMING. THE EASTERN FORECAST
AREA HAD VERY LIGHT TO CALM WIND...BUT THE WESTERN FORECAST AREA
HAD INCREASING SE WINDS. THE TEMPERATURES RANGED FROM THE SINGLE
DIGITS IN THE ARROWHEAD TO THE MID TO UPPER TEENS ACROSS THE REST
OF THE FORECAST AREA.
THE FOCUS FOR THIS FORECAST IS THE ROUND OF SNOW EXPECTED TO MOVE
THROUGH THE NORTHLAND AFTER MIDNIGHT AND THROUGH MONDAY IN ADVANCE
OF THE TROUGH/WARM FRONT WHICH WILL MOVE THROUGH THE NORTHLAND
MONDAY. SOME MODELS INCREASED PCPN AMOUNTS FOR SOME AREAS...WHICH
RESULTED IN INCREASING SNOWFALL AMOUNTS...SUCH AS FOR THE TWIN
PORTS. WIDESPREAD SNOWFALL AMOUNTS AROUND 6 INCHES ARE EXPECTED
FOR THE TWIN PORTS AREA AND ALONG THE INTERSTATE 35 CORRIDOR...AND
CONSIDERING PERIODS OF HEAVY SNOWFALL RATES COULD MAKE FOR
DIFFICULT DRIVING CONDITIONS FOR THE MORNING COMMUTE...I DECIDED
TO EXPAND THE WINTER STORM WARNING TO THE SOUTH CENTRAL FORECAST
AREA.
SNOW WILL BEGIN TO SPREAD INTO NORTH CENTRAL AND CENTRAL MINNESOTA
AROUND MIDNIGHT AS THE TROUGH/WARM FRONT MOVE INTO THE
CENTRAL/EASTERN DAKOTAS AROUND THIS TIME. THE SNOW WILL QUICKLY
SPREAD INTO NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN AFTER
MIDNIGHT AND MONDAY MORNING. THERE ARE STILL SOME DIFFERENCES IN
MODEL PCPN AMOUNTS AND SLIGHTLY DIFFERENT TIMING. I LEANED ON A
WIDE BLEND...BUT PERHAPS A LITTLE MORE TOWARDS THE SREF. THE
MODELS...INCLUDING THE SREF...SUGGEST WIDESPREAD 4 TO 7 INCHES
WITH THE HIGHEST AMOUNTS ACROSS THE CENTRAL AND EASTERN FORECAST
AREA. DESPITE THE WARMER AIR WITH THIS SYSTEM...SEVERAL MODELS ARE
SUGGESTING SNOW TO LIQUID RATIOS AROUND OR GREATER THAN 15 TO 1.
THIS MAY IN PART DUE TO THE LIKELIHOOD OF SOME ENHANCED DEPTH AND
LIFT IN THE DENDRITIC GROWTH ZONE...WHICH WILL HELP INCREASE THE
SNOW TO LIQUID RATIOS. THE HIGHEST AMOUNTS OF SNOW WILL LIKELY BE
ALONG THE NORTH SHORE...WHERE AMOUNTS COULD REACH UP TO 8 INCHES
DUE TO A LITTLE LAKE ENHANCEMENT FROM SE TO E WINDS. GRANTED...THE
LAKE IS FAIRLY ICE COVERED...BUT WE HAVE STILL BEEN SEEING SOME
LAKE ENHANCEMENT AND LIGHT LAKE EFFECT SNOW RECENTLY.
THE SNOW WILL BEGIN TO MOVE EAST OF THE NORTHLAND MONDAY
AFTERNOON. HIGH TEMPERATURES WILL BE LIMITED TO THE LOW TO MID 20S
ACROSS THE EASTERN FORECAST AREA...BUT PARTS OF THE WESTERN
FORECAST WILL LIKELY SEE ABOVE FREEZING TEMPERATURES THANKS TO
PARTIAL SUNSHINE IN THE MID TO LATE AFTERNOON.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 301 PM CST SUN FEB 16 2014
SIGNIFICANT SNOW SHOULD BE DIMINISHING RAPIDLY ACROSS THE EASTERN
SECTIONS OF THE DULUTH CWA..OR ENDED ALTOGETHER..BY THE
BEGINNING OF THE MONDAY NIGHT PERIOD. SECONDARY S/W TROF WILL
ROTATE EASTWARD ACROSS THE NORTHLAND MONDAY NIGHT/TUE
MORNING..WITH CONTINUED LOW LEVEL WARM ADVECTION IN OUR BRIEF
EXCURSION INTO THE WARM SECTOR. THIS SHOULD BE SUFFICIENT TO
SQUEEZE OUT SOME VERY LIGHT PRECIP. MOST LIKELY IN THE FORM OF
SOME PATCHY LIGHT SNOW OVER THE FAR NORTH..BUT PROBABLY IN THE
FORM OF FLURRIES OR SOME PATCHY LIGHT FREEZING DRIZZLE ALONG AND
SOUTH OF THE HIGHWAY 2 CORRIDOR. OVERALL..NOT A MAJOR EVENT..BUT
COULD BE ENOUGH TO PROLONG SLICK ROADS IN MANY AREAS IN THE WAKE
OF MODERATE SNOWFALL TONIGHT AND MONDAY.
WEAK COLD ADVECTION AND HIGH PRESSURE WILL THEN BUILD INTO THE
REGION LATER TUESDAY/WEDNESDAY. HOWEVER..UNLIKE MOST OF THE LAST 2
MONTHS..THIS POST-FRONTAL AIRMASS WILL HAVE ITS SOURCE REGION IN
THE DOWNSLOPE OF THE NORTHERN ROCKIES. AS A RESULT..TUE/WED SHOULD
BE CONSIDERABLY WARMER ACROSS THE REGION..ESPECIALLY WITH THE
STRONGER FEBRUARY SUN AND LONGER DAYS..WHICH WILL ALLOW INSOLATION
TO INTERACT WITH THE LOWER ALBEDO OF THE FORESTED AREAS. WE HAVE
RAISED MAX TEMPS SOME FROM THE PREVIOUS FORECAST FOR BOTH
DAYS..AND SOME AREAS ON WED COULD PUSH 40 ACROSS NW WISCONSIN AND
PARTS OF NE MN.
NEXT RAPIDLY MOVING DISTURBANCE WILL MOVE ACROSS THE NORTHERN TIER
OF STATES MID WEEK..AFFECTING THE NORTHLAND WED NIGHT/THUR.
RIGHT NOW..MOST CURRENT MEDIUM RANGE GUIDANCE DEPICTS THE
ORIENTATION AND DYNAMIC FORCING WITH THIS SYSTEM AS SIMILAR TO THE
ONE FOR TONIGHT AND MONDAY..WITH A RAPID INCREASE IN STRONG UPWARD
VERTICAL MOTION FIELDS DEVELOPING ACROSS MN LATER WED NIGHT/THUR
MORNING. AIRMASS WILL NOT BE AS COLD..SO SNOW RATIOS WILL BE
LOWER..AND SOME PRECIP COULD BE A MIX OR RAIN ACROSS THE FAR SOUTH
DEPENDING ON THE EVENTUAL EVOLUTION OF THE WARM SECTOR.
SO..SNOWFALL AMOUNTS MAY BE LESSER AND SNOW OF THE HEAVIER/WETTER
VARIETY. HOWEVER..IT SHOULD BE NOTED THAT THE STRENGTH OF THE
VERTICAL MOTION FIELDS AND RAPID DEVELOPMENT OF PRECIP WED NIGHT
WOULD ARGUE FOR STRONG DYNAMIC AND DIABATIC COOLING OF THE LOWER
PORTIONS OF THE ATMOSPHERE..AND THUS A MOSTLY SNOW SOLUTION. OF
COURSE..THE ECM/GFS HAVE A HARDER TIME HANDLING THE NORTHWARD
SURGE OF THE WARM AIR ALOFT..SO THE POTENTIAL FOR MIXED PRECIP OR
RAIN SEEMS TO BE BACK ON THE TABLE A BIT MORE THAN THIS TIME
YESTERDAY. PTYPE ISSUES SHOULD BECOME CLEARER WHEN THIS SYSTEM
GETS INTO THE 84 HR FORECAST WINDOW OF THE WRF-BASED MODELS AND
ENSEMBLE SYSTEMS THAT SEEM TO HANDLE THE RETURNING WARM LAYER IN
STRONG WARM ADVECTION PATTERNS BETTER.
FOR THE THUR-SAT TIME FRAME..MORE NORTHERLY COMPONENT TO THE FLOW
ALOFT DEVELOPS ONCE AGAIN..WITH THE STORM TRACK RETREATING
SOUTHWARD. AS A RESULT..PROGRESSIVELY COLDER AIR OF MORE ARCTIC
ORIGIN SHOULD GRADUALLY BECOME ESTABLISHED ONCE AGAIN..ALONG WITH
A FEW CHANCES FOR SOME LIGHT SNOW. ANOTHER STRONG PUSH OF VERY
COLD ARCTIC AIR WITH 850 TEMPS AOB -25C LOOKS TO BE ON TAP FOR
LATE NEXT WEEKEND AND THE BEGINNING OF THE WEEK OF FEB 24..JUST
BEYOND THE RANGE OF THIS 7 DAY FORECAST WINDOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1145 PM CST SUN FEB 16 2014
GUSTY SOUTHEAST WINDS WILL PREVAIL OVERNIGHT AHEAD OF A STRONG
FRONT. THE FRONT WILL SPREAD LOWERING CEILINGS AND SNOW ACROSS
THE FORECAST AREA THROUGH DAYBREAK. THERE WILL BE A 4-6 HOUR
WINDOW OF +SN WITH RAPID ACCUMULATIONS AND IFR/LIFR CIGS THROUGH
MONDAY MORNING. PLEASE REFER TO THE LATEST WINTER WEATHER MESSAGE
FOR MORE DETAILS ON SNOW AMOUNTS. AS THE FRONT TRANSLATES EAST
ACROSS THE REGION MONDAY AFTERNOON...WINDS WILL TURN OUT OF THE
WEST AND CONDITIONS WILL RAPIDLY IMPROVE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 4 25 18 37 / 100 100 10 20
INL 11 26 18 31 / 100 100 30 30
BRD 15 34 21 36 / 100 100 10 10
HYR 9 28 17 40 / 90 100 10 10
ASX -1 28 18 38 / 90 100 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WARNING UNTIL 6 PM CST MONDAY FOR MNZ012-020-021.
WINTER WEATHER ADVISORY UNTIL NOON CST MONDAY FOR MNZ010-018-025-
026-033>036.
WINTER STORM WARNING UNTIL 3 PM CST MONDAY FOR MNZ037-038.
WINTER WEATHER ADVISORY UNTIL 3 PM CST MONDAY FOR MNZ011-019.
WI...WINTER STORM WARNING UNTIL 3 PM CST MONDAY FOR WIZ001>004-
006>009.
LS...NONE.
&&
$$
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1210 PM CST Mon Feb 17 2014
.UPDATE...
Issued at 1207 PM CST MON FEB 17 2014
The last of the snow and sleet has exited the CWA and clear skies
have replaced the clouds. Gusty west-northwest winds with pronounced downslope
component is allowing temperatures to warm quickly...and ahead of
early forecasts. Have raised high temperatures by 3-5F for all but
the far eastern counties.
UPDATE Issued at 644 AM CST MON FEB 17 2014
Precipitation is rapidly clearing out from west to east so the threat
for significant snow and ice is decreasing. Additional icing will be
confined to the Moberly/Macon/Kirksville areas and should just be a
few hundredths of an inch. Band of light precipitation swinging
through far northern MO near Maryville and Bethany is a mix of snow,
sleet and rain/freezing rain and will produce very minor snow
accumulations less than an inch. It`s possible that precipitation
could fill in a bit more over far northern MO over the next few
hours and produce up to an inch of snow near Milan and Kirksville.
Will continue to remove counties from the advisories as needed as
temperatures rise above freezing and precipitation tapers off from
west to east.
&&
.DISCUSSION...
Issued at 346 AM CST MON FEB 17 2014
Freezing rain is blossoming across central and northern MO early this
morning in an area of deep isentropic ascent and increasing moisture.
The freezing line has been able to lift a tad further north than what
was forecast and currently stretches from just north of St. Joseph to
near Chillicothe and just north of Boonville. Temperatures are
expected to remain above freezing for the remainder of the day for
areas south of this line so the freezing rain advisory will be
adjusted to remove a few counties near St. Joe.
Further north and east, concern is growing that ice totals may be a
bit higher than previously forecast for the Kirksville, Milan and
Macon areas. Both the RAP and HRRR have been persistent in producing
QPF amounts around a half inch for these areas through mid-morning,
most of which would fall as freezing rain. If these amounts were to
verify, several counties across northern and northeast Missouri would
see ice accumulations between a quarter of an inch and a half inch
which would push them into ice storm warning criteria. However, both
of these models have been initializing with precipitation too far
west near Kansas City where radar echoes have been slow to develop.
Isentropic ascent is currently maximized near and east of the US 65
corridor which is where most of the precipitation is, with only weak
ascent if not downglide starting to push into western MO. This
downglide is forecast to increase through the morning so that
precipitation may struggle to intensify over western MO, causing the
RAP and HRRR precipitation forecasts to be too high. Will therefore
stick with ice totals of a quarter inch or less for northeastern
portions of the forecast area. However this area will be watched
very closely in case precipitation does expand further west and leads
to more ice accumulation than what is currently forecast.
Colder air will filter in aloft after 8 am and cause precipitation
over northern MO to mix with sleet and snow. Snow and sleet
accumulations up to an inch are possible mainly north of a Maryville
to Kirksville line. Any sleet and snow should be fairly short lived
as isentropic downglide will really increase after 15Z and bring
precipitation to a rapid end by noon.
The main story behind this system will be rising temperatures with
westerly downslope flow bringing temperatures into the middle and
upper 50s for most areas on Tuesday. The next weather maker will
arrive Wednesday night and Thursday when a surface low will track
from southern Kansas into central and northeast Missouri. Rain will
overspread the area ahead of this system Wednesday night and Thursday
morning and there could be a few thunderstorms near and south of the
surface low track. Quasi-zonal upper flow behind this system will
keep temperatures several degrees above average through Friday.
Models continue to advertise a weak system moving into the area over
the weekend with the potential for light wintry precipitation.
Higher preference was placed on the more consistent GFS solution
which would keep any precipitation amounts fairly light.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1125 AM CST MON FEB 17 2014
Skies have rapidly cleared across western MO this morning and will
remain clear for this forecast. Back edge of snow has pushed into far
northeast MO and will exit there shortly. Strong northwest winds
aloft have mixed down to the surface so gusty winds will continue
until late afternoon.
Impressive looking inversion expected to form within the boundary
layer later this evening. Southwesterly winds will ramp up just above
this inversion resulting in LLWS concerns by the pre-dawn hours of
Tuesday morning. Once inversion begins to break down by mid-morning
winds will become gusty rapidly.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
DISCUSSION...Hawblitzel
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1131 AM CST Mon Feb 17 2014
.UPDATE...
Issued at 644 AM CST MON FEB 17 2014
Precipitation is rapidly clearing out from west to east so the threat
for significant snow and ice is decreasing. Additional icing will be
confined to the Moberly/Macon/Kirksville areas and should just be a
few hundredths of an inch. Band of light precipitation swinging
through far northern MO near Maryville and Bethany is a mix of snow,
sleet and rain/freezing rain and will produce very minor snow
accumulations less than an inch. It`s possible that precipitation
could fill in a bit more over far northern MO over the next few
hours and produce up to an inch of snow near Milan and Kirksville.
Will continue to remove counties from the advisories as needed as
temperatures rise above freezing and precipitation tapers off from
west to east.
&&
.DISCUSSION...
Issued at 346 AM CST MON FEB 17 2014
Freezing rain is blossoming across central and northern MO early this
morning in an area of deep isentropic ascent and increasing moisture.
The freezing line has been able to lift a tad further north than what
was forecast and currently stretches from just north of St. Joseph to
near Chillicothe and just north of Boonville. Temperatures are
expected to remain above freezing for the remainder of the day for
areas south of this line so the freezing rain advisory will be
adjusted to remove a few counties near St. Joe.
Further north and east, concern is growing that ice totals may be a
bit higher than previously forecast for the Kirksville, Milan and
Macon areas. Both the RAP and HRRR have been persistent in producing
QPF amounts around a half inch for these areas through mid-morning,
most of which would fall as freezing rain. If these amounts were to
verify, several counties across northern and northeast Missouri would
see ice accumulations between a quarter of an inch and a half inch
which would push them into ice storm warning criteria. However, both
of these models have been initializing with precipitation too far
west near Kansas City where radar echoes have been slow to develop.
Isentropic ascent is currently maximized near and east of the US 65
corridor which is where most of the precipitation is, with only weak
ascent if not downglide starting to push into western MO. This
downglide is forecast to increase through the morning so that
precipitation may struggle to intensify over western MO, causing the
RAP and HRRR precipitation forecasts to be too high. Will therefore
stick with ice totals of a quarter inch or less for northeastern
portions of the forecast area. However this area will be watched
very closely in case precipitation does expand further west and leads
to more ice accumulation than what is currently forecast.
Colder air will filter in aloft after 8 am and cause precipitation
over northern MO to mix with sleet and snow. Snow and sleet
accumulations up to an inch are possible mainly north of a Maryville
to Kirksville line. Any sleet and snow should be fairly short lived
as isentropic downglide will really increase after 15Z and bring
precipitation to a rapid end by noon.
The main story behind this system will be rising temperatures with
westerly downslope flow bringing temperatures into the middle and
upper 50s for most areas on Tuesday. The next weather maker will
arrive Wednesday night and Thursday when a surface low will track
from southern Kansas into central and northeast Missouri. Rain will
overspread the area ahead of this system Wednesday night and Thursday
morning and there could be a few thunderstorms near and south of the
surface low track. Quasi-zonal upper flow behind this system will
keep temperatures several degrees above average through Friday.
Models continue to advertise a weak system moving into the area over
the weekend with the potential for light wintry precipitation.
Higher preference was placed on the more consistent GFS solution
which would keep any precipitation amounts fairly light.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1125 AM CST MON FEB 17 2014
Skies have rapidly cleared across western MO this morning and will
remain clear for this forecast. Back edge of snow has pushed into far
northeast MO and will exit there shortly. Strong northwest winds
aloft have mixed down to the surface so gusty winds will continue
until late afternoon.
Impressive looking inversion expected to form within the boundary
layer later this evening. Southwesterly winds will ramp up just above
this inversion resulting in LLWS concerns by the pre-dawn hours of
Tuesday morning. Once inversion begins to break down by mid-morning
winds will become gusty rapidly.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...FREEZING RAIN ADVISORY until Noon CST today FOR MOZ024-025-032-
033.
WINTER WEATHER ADVISORY until Noon CST today FOR MOZ007-008-016-
017.
&&
$$
UPDATE...Hawblitzel
DISCUSSION...Hawblitzel
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
644 AM CST Mon Feb 17 2014
.UPDATE...
Issued at 644 AM CST MON FEB 17 2014
Precipitation is rapidly clearing out from west to east so the threat
for significant snow and ice is decreasing. Additional icing will be
confined to the Moberly/Macon/Kirksville areas and should just be a
few hundredths of an inch. Band of light precipitation swinging
through far northern MO near Maryville and Bethany is a mix of snow,
sleet and rain/freezing rain and will produce very minor snow
accumulations less than an inch. It`s possible that precipitation
could fill in a bit more over far northern MO over the next few
hours and produce up to an inch of snow near Milan and Kirksville.
Will continue to remove counties from the advisories as needed as
temperatures rise above freezing and precipitation tapers off from
west to east.
&&
.DISCUSSION...
Issued at 346 AM CST MON FEB 17 2014
Freezing rain is blossoming across central and northern MO early this
morning in an area of deep isentropic ascent and increasing moisture.
The freezing line has been able to lift a tad further north than what
was forecast and currently stretches from just north of St. Joseph to
near Chillicothe and just north of Boonville. Temperatures are
expected to remain above freezing for the remainder of the day for
areas south of this line so the freezing rain advisory will be
adjusted to remove a few counties near St. Joe.
Further north and east, concern is growing that ice totals may be a
bit higher than previously forecast for the Kirksville, Milan and
Macon areas. Both the RAP and HRRR have been persistent in producing
QPF amounts around a half inch for these areas through mid-morning,
most of which would fall as freezing rain. If these amounts were to
verify, several counties across northern and northeast Missouri would
see ice accumulations between a quarter of an inch and a half inch
which would push them into ice storm warning criteria. However, both
of these models have been initializing with precipitation too far
west near Kansas City where radar echoes have been slow to develop.
Isentropic ascent is currently maximized near and east of the US 65
corridor which is where most of the precipitation is, with only weak
ascent if not downglide starting to push into western MO. This
downglide is forecast to increase through the morning so that
precipitation may struggle to intensify over western MO, causing the
RAP and HRRR precipitation forecasts to be too high. Will therefore
stick with ice totals of a quarter inch or less for northeastern
portions of the forecast area. However this area will be watched
very closely in case precipitation does expand further west and leads
to more ice accumulation than what is currently forecast.
Colder air will filter in aloft after 8 am and cause precipitation
over northern MO to mix with sleet and snow. Snow and sleet
accumulations up to an inch are possible mainly north of a Maryville
to Kirksville line. Any sleet and snow should be fairly short lived
as isentropic downglide will really increase after 15Z and bring
precipitation to a rapid end by noon.
The main story behind this system will be rising temperatures with
westerly downslope flow bringing temperatures into the middle and
upper 50s for most areas on Tuesday. The next weather maker will
arrive Wednesday night and Thursday when a surface low will track
from southern Kansas into central and northeast Missouri. Rain will
overspread the area ahead of this system Wednesday night and Thursday
morning and there could be a few thunderstorms near and south of the
surface low track. Quasi-zonal upper flow behind this system will
keep temperatures several degrees above average through Friday.
Models continue to advertise a weak system moving into the area over
the weekend with the potential for light wintry precipitation.
Higher preference was placed on the more consistent GFS solution
which would keep any precipitation amounts fairly light.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday Morning)
Issued at 525 AM CST MON FEB 17 2014
Back edge of precipitation is currently close to a STJ-MCI-SZL line
with mainly dry conditions expected to the west of this line for the
rest of the day. Clearing line already near TOP will make it into the
KC area within the next hour or two.
Further east areas of freezing rain will impact areas around IRK for
several more hours with a tenth or two of ice accumulation expected.
Sleet and snow may also fall across this area with minor
accumulations. Clearing will reach IRK by 18Z.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...FREEZING RAIN ADVISORY until Noon CST today FOR MOZ014-023>025-
032-033-040.
WINTER WEATHER ADVISORY until 9 AM CST this morning FOR MOZ003-
004.
WINTER WEATHER ADVISORY until Noon CST today FOR MOZ005>008-
015>017.
&&
$$
UPDATE...Hawblitzel
DISCUSSION...Hawblitzel
AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
523 AM CST Mon Feb 17 2014
.DISCUSSION...
Issued at 346 AM CST MON FEB 17 2014
Freezing rain is blossoming across central and northern MO early this
morning in an area of deep isentropic ascent and increasing moisture.
The freezing line has been able to lift a tad further north than what
was forecast and currently stretches from just north of St. Joseph to
near Chillicothe and just north of Boonville. Temperatures are
expected to remain above freezing for the remainder of the day for
areas south of this line so the freezing rain advisory will be
adjusted to remove a few counties near St. Joe.
Further north and east, concern is growing that ice totals may be a
bit higher than previously forecast for the Kirksville, Milan and
Macon areas. Both the RAP and HRRR have been persistent in producing
QPF amounts around a half inch for these areas through mid-morning,
most of which would fall as freezing rain. If these amounts were to
verify, several counties across northern and northeast Missouri would
see ice accumulations between a quarter of an inch and a half inch
which would push them into ice storm warning criteria. However, both
of these models have been initializing with precipitation too far
west near Kansas City where radar echoes have been slow to develop.
Isentropic ascent is currently maximized near and east of the US 65
corridor which is where most of the precipitation is, with only weak
ascent if not downglide starting to push into western MO. This
downglide is forecast to increase through the morning so that
precipitation may struggle to intensify over western MO, causing the
RAP and HRRR precipitation forecasts to be too high. Will therefore
stick with ice totals of a quarter inch or less for northeastern
portions of the forecast area. However this area will be watched
very closely in case precipitation does expand further west and leads
to more ice accumulation than what is currently forecast.
Colder air will filter in aloft after 8 am and cause precipitation
over northern MO to mix with sleet and snow. Snow and sleet
accumulations up to an inch are possible mainly north of a Maryville
to Kirksville line. Any sleet and snow should be fairly short lived
as isentropic downglide will really increase after 15Z and bring
precipitation to a rapid end by noon.
The main story behind this system will be rising temperatures with
westerly downslope flow bringing temperatures into the middle and
upper 50s for most areas on Tuesday. The next weather maker will
arrive Wednesday night and Thursday when a surface low will track
from southern Kansas into central and northeast Missouri. Rain will
overspread the area ahead of this system Wednesday night and Thursday
morning and there could be a few thunderstorms near and south of the
surface low track. Quasi-zonal upper flow behind this system will
keep temperatures several degrees above average through Friday.
Models continue to advertise a weak system moving into the area over
the weekend with the potential for light wintry precipitation.
Higher preference was placed on the more consistent GFS solution
which would keep any precipitation amounts fairly light.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday Morning)
Issued at 525 AM CST MON FEB 17 2014
Back edge of precipitation is currently close to a STJ-MCI-SZL line
with mainly dry conditions expected to the west of this line for the
rest of the day. Clearing line already near TOP will make it into the
KC area within the next hour or two.
Further east areas of freezing rain will impact areas around IRK for
several more hours with a tenth or two of ice accumulation expected.
Sleet and snow may also fall across this area with minor
accumulations. Clearing will reach IRK by 18Z.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...FREEZING RAIN ADVISORY until Noon CST today FOR MOZ014-022>025-
032-033-040.
WINTER WEATHER ADVISORY until Noon CST today FOR MOZ005>008-
015>017.
FREEZING RAIN ADVISORY until 9 AM CST this morning FOR
MOZ011>013.
WINTER WEATHER ADVISORY until 9 AM CST this morning FOR
MOZ001>004.
&&
$$
DISCUSSION...Hawblitzel
AVIATION...Hawblitzel
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
348 AM CST Mon Feb 17 2014
.DISCUSSION...
Issued at 346 AM CST MON FEB 17 2014
Freezing rain is blossoming across central and northern MO early this
morning in an area of deep isentropic ascent and increasing moisture.
The freezing line has been able to lift a tad further north than what
was forecast and currently stretches from just north of St. Joseph to
near Chillicothe and just north of Boonville. Temperatures are
expected to remain above freezing for the remainder of the day for
areas south of this line so the freezing rain advisory will be
adjusted to remove a few counties near St. Joe.
Further north and east, concern is growing that ice totals may be a
bit higher than previously forecast for the Kirksville, Milan and
Macon areas. Both the RAP and HRRR have been persistent in producing
QPF amounts around a half inch for these areas through mid-morning,
most of which would fall as freezing rain. If these amounts were to
verify, several counties across northern and northeast Missouri would
see ice accumulations between a quarter of an inch and a half inch
which would push them into ice storm warning criteria. However, both
of these models have been initializing with precipitation too far
west near Kansas City where radar echoes have been slow to develop.
Isentropic ascent is currently maximized near and east of the US 65
corridor which is where most of the precipitation is, with only weak
ascent if not downglide starting to push into western MO. This
downglide is forecast to increase through the morning so that
precipitation may struggle to intensify over western MO, causing the
RAP and HRRR precipitation forecasts to be too high. Will therefore
stick with ice totals of a quarter inch or less for northeastern
portions of the forecast area. However this area will be watched
very closely in case precipitation does expand further west and leads
to more ice accumulation than what is currently forecast.
Colder air will filter in aloft after 8 am and cause precipitation
over northern MO to mix with sleet and snow. Snow and sleet
accumulations up to an inch are possible mainly north of a Maryville
to Kirksville line. Any sleet and snow should be fairly short lived
as isentropic downglide will really increase after 15Z and bring
precipitation to a rapid end by noon.
The main story behind this system will be rising temperatures with
westerly downslope flow bringing temperatures into the middle and
upper 50s for most areas on Tuesday. The next weather maker will
arrive Wednesday night and Thursday when a surface low will track
from southern Kansas into central and northeast Missouri. Rain will
overspread the area ahead of this system Wednesday night and Thursday
morning and there could be a few thunderstorms near and south of the
surface low track. Quasi-zonal upper flow behind this system will
keep temperatures several degrees above average through Friday.
Models continue to advertise a weak system moving into the area over
the weekend with the potential for light wintry precipitation.
Higher preference was placed on the more consistent GFS solution
which would keep any precipitation amounts fairly light.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1156 PM CST SUN FEB 16 2014
Models have been a little too aggressive bringing low ceilings
northward this evening, and feel this trend may continue. Ceilings
will gradually fall into MVFR category towards 3am as low level lift
increases. There will be a brief window where ceilings drop to IFR
levels towards daybreak ahead of a weak surface trough. Scattered
showers and or drizzle will work across the KC terminals through
daybreak, but with temperatures already at or above freezing, the
icing threat should be minimal. Ceilings should quickly rebound after this
front moves through at 15Z, with VFR skies and gusty west northwest
winds through the afternoon.
At STJ, and across northern Missouri, slightly higher potential for
light icing, with a brief changeover to snow at STJ after daybreak.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...FREEZING RAIN ADVISORY until Noon CST today FOR MOZ014-022>025-
032-033-040.
WINTER WEATHER ADVISORY until Noon CST today FOR MOZ005>008-
015>017.
FREEZING RAIN ADVISORY until 9 AM CST this morning FOR
MOZ011>013.
WINTER WEATHER ADVISORY until 9 AM CST this morning FOR
MOZ001>004.
&&
$$
DISCUSSION...Hawblitzel
AVIATION...Dux
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1212 AM CST Mon Feb 17 2014
.UPDATE...
Issued at 934 PM CST SUN FEB 16 2014
We have made some tweaks to PoPs overnight along with adding a
slight chance for thunder across much of the area.
The latest surface analysis indicates a warm front extending from
central Kansas, south to around Stillwater, Oklahoma. This front
then continues southeast to around Lake Eufaula in east-central
Oklahoma. Dew points to the south of this front across Oklahoma
have actually risen into the lower and middle 50s. North of the
front across the Ozarks, dew points ranged from the middle 20s to
lower 30s. 9 PM temperatures were still in the middle to upper 40s
across southwestern Missouri. In contrast, temperatures around
Rolla and Salem were in the lower to middle 30s.
Later this evening and overnight, weak surface low pressure will
develop across north-central Oklahoma as digging short wave energy
emerges across the central Plains. This low will pull northeast
towards Kansas City by around sunrise. The warm front will follow
suit and push northeast into western Missouri. Ahead of this
front, lift will rapidly increase in both the low levels
(isentropic upglide owing to a 50 knot low level jet) and the
upper levels. Rain showers are therefore expected to blossom and
increase in coverage starting around 06 UTC or shortly thereafter.
We have maintained high-end likely and categorical PoPs across
central Missouri where low-level moisture transport and theta-e
advection will be maximized. In contrast, we have slightly lowered
PoPs overnight near the Arkansas border where low level lift will
be weaker.
We have also added a slight chance for thunder generally along and
north of the Interstate 44 corridor late tonight. The last three
runs of the RAP and to some extent the NAM have latched onto a
slug of MUCAPEs in the 300-600 J/kg range with source parcels
rooted in the 825-750 mb layer. As that digging wave approaches, a
quick cooling of mid-level temperatures may also support some
small hail/graupel from any thunderstorms or heavier showers.
We are still concerned about the potential for some freezing rain
late tonight as those showers develop and push into the eastern
Ozarks. While southeasterly winds will increase and result in
steady or slowly rising temperatures, we will also see wet-bulbing
as precipitation falls into a relatively dry low-level air mass.
At this time, the main area of concern is up across eastern Maries
and Phelps Counties where shower coverage will be greatest and
temperatures will be right around the freezing mark. We will also
have to watch areas down towards Salem and Eminence if shower
activity manages to develop farther south.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 146 PM CST SUN FEB 16 2014
Another challenging and complex day of temperatures across the
area today. Clouds and easterly winds have wreaked havoc, with
temperatures barely moving in central Missouri with modest warming
elsewhere. In the coming hours, should see some additional warming
with readings varying from the mid 30s in central Missouri to the
low/mid 50s across southern Missouri.
The forecast gets even more complicated tonight and Monday. A
potent shortwave will traverse the upper Midwest sending a front
through the area. Southerly flow will increase rapidly tonight
ahead of this system. Should see temperatures fall to their
minimums during the late evening hours, then steady off/rise
during the overnight hours. This situation is rather similar to
what we saw last Thursday night into Friday morning. In similar
fashion there is a risk for some light freezing rain across the
eastern Ozarks between 3-8 AM. Temperatures look to hold right
near the freezing mark during this time frame, especially in the
valleys and lower lying areas of Dent/Shannon/Oregon counties.
This will not be a widespread risk, nor are we expecting more than
just a thin glaze of patchy accumulation. Nevertheless, this could
cause brief travel challenges for the morning rush.
Main forcing with this system will be targeting areas to our
north. Warm advection regime will spark isolated to widely
scattered showers after midnight, and this will get more organized
along a front that will quickly move through the area during the
daylight hours of Monday morning. Rainfall amounts will be on the
order of hundredths of an inch in most locations. Central Missouri
could see totals in the one to two tenths of an inch range. As
fast as rain moves in, it will exit to the east and we should see
some clearing during the afternoon. Temperatures will continue to
remain tricky, but stay seasonable for the time of year. Highs
should range from the 40s east to mid 50s west.
.LONG TERM...(Monday Night through Sunday)
Issued at 146 PM CST SUN FEB 16 2014
Milder temperatures will begin to move in for Tuesday through the
middle part of the week. Winds will become breezy especially over
the western half of the area on Tuesday afternoon. Will have to
watch for elevated fire weather conditions Tuesday afternoon
depending on gusty winds and the lower atmosphere mixing out.
The next storm system to affect the area will be moving in
Wednesday night through Thursday. Cold front will move into the
area very late Wednesday night into Thursday morning. Widespread
rainfall is expected with embedded thunder. The better dynamics
and thermal profiles for stronger convection will be just off to
our southeast with an earlier passage of the cold front during the
day through most of the Ozarks. Average rainfall amounts will
range from a quarter to half an inch.
Cooler weather will follow for the end of the week into next
weekend. The models are in disagreement with the Friday night into
Saturday time frame. The GFS keeps the area dry with a west-
northwest flow and high pressure in control. The ECMWF has a
robust shortwave moving through the area with quick round of
precip and colder solution. At this time...have leaned more
towards the ECMWF solution for the weekend time frame with precip
chances Friday night into Saturday and colder temperatures.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1154 PM CST SUN FEB 16 2014
A quick moving storm system will bring multiple impacts to the
area over the next 18 hours. First off, low level wind shear will
continue into early Monday morning as a low level jet stream
remains over the region. Brisk and gusty southeasterly surface
winds will also persist overnight. We will also see showers
develop with even a few thunderstorms possible. At this time, we
think the best threat for any thunderstorms will be around
Springfield late tonight and early Monday morning. We have covered
this with a TEMPO group. Weather models have backed off somewhat
on MVFR potential late tonight and early Monday morning. We
therefore brought MVFR in as a TEMPO group instead of going with
prevailing groups. A cold front will then sweep through the area
around mid-morning which will bring an end to the rain showers.
Winds will become brisk and gusty out of the northwest behind the
front with clouds clearing by early afternoon. Winds will then
quickly diminish Monday evening.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
UPDATE...Schaumann
SHORT TERM...Gagan
LONG TERM...Griffin
AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1048 AM MST MON FEB 17 2014
.UPDATE...
HAVE ADDED WHEATLAND COUNTY TO THE HIGH WIND WARNING AS JUDITH GAP
RECENTLY GUSTED TO THE MID 50S...WITH PEAK WINDS EXPECTED LATER
TODAY. NO OTHER CHANGES AT THIS TIME. JKL
PREVIOUS DISCUSSION ISSUED 904 AM...
CONDITIONS HAVE BECOME A BIT MORE FAVORABLE FOR WINDS AT
LIVINGSTON THIS MORNING...WITH A BACKED GRADIENT DUE TO WESTERN
AND CENTRAL MT PRESSURE FALLS...AND WINDS HAVE INCREASED AS A
RESULT HERE AND DECREASED AT SUCH PLACES AS BIG TIMBER...HARLOWTON
AND JUDITH GAP. ONSET OF COLD ADVECTION AND DESTABILIZING WILL
ALLOW FOR WINDS TO INCREASE AGAIN THRU SWEET GRASS AND WHEATLAND
COUNTIES THIS AFTERNOON...SO THE CURRENT LULL IS ONLY TEMPORARY.
AM A BIT CONCERNED THAT GUSTS COULD PUSH 60 MPH IN WHEATLAND
COUNTY LATER TODAY WITH MIXING BUT THERE ARE A COUPLE FACTORS
WORKING AGAINST THIS...PRESSURE FALLS TO OUR SOUTH IN ID/WY AND
SOME SYNOPTIC SCALE ASCENT AS SHORTWAVE ENERGY APPROACHES FROM
THE WEST. SO WILL KEEP GUSTS LIMITED TO 50-55 MPH AT HARLOWTON AND
JUDITH GAP. WINDS WILL REMAIN STRONG THRU TONIGHT. WILL MAKE NO
CHANGES TO THE WIND HIGHLIGHTS FOR LIVINGSTON...NYE AND BIG
TIMBER. SURPRISE SURPRISE ANOTHER WINDY DAY FOLKS.
THERE IS QUITE A BIT OF WIND FLOW OVER THE CREST OF THE BIG HORNS
THIS MORNING AND BURGESS JCT WINDS WERE GUSTING NEAR 50 MPH AT 8
AM. RAP SUGGESTS THAT THRU MIXING SHERIDAN WILL SEE INCREASED WSW
GUSTS LATER THIS MORNING...BUT FEEL THAT WITHOUT STRONGER DESCENT
WE WILL NOT SEE THAT DEGREE OF WIND PUSH DOWN THE LEE OF THE MTNS.
THAT BEING SAID WILL NEED TO WATCH THE SHERIDAN AREA TODAY AND
HAVE RAISED WIND SPEEDS TO SHOW GUSTS TO 30 MPH TODAY.
OTHER THAN WIND THERE ARE NO OTHER FORECAST ISSUES TODAY. TEMPS
WILL RISE TO THE 40S OR LOW 50S WITH PERSISTENT DOWNSLOPE
CONDITIONS AND A FRONTAL PASSAGE LATE. SNOW SHOWERS WILL INCREASE
OVER THE WEST SLOPES AFTER 00Z.
JKL
&&
.SHORT TERM...VALID FOR TDY AND TUE...
UPPER JET ENERGY WILL CONTINUE TO MOVE ACROSS THE AREA CREATING A
FAST WESTERLY FLOW THROUGH THE FORECAST PERIOD. ENSEMBLE
SITUATIONAL AWARENESS TABLE CONTINUED TO HIGHLIGHT ANOMALOUSLY
HIGH MID LEVEL WINDS WITH SOME ANOMALIES SHOWING UP AT 850 MB AS
WELL. FORECAST CHALLENGE CONTINUES TO BE HOW MUCH WIND WILL REACH
THE GROUND. HOWEVER...FOR THIS MORNING IN KLVM...NYE AND BIG
TIMBER...THE CAUSATIVE FACTORS FOR WINDS WILL BE GAP FLOW AND IN
THE CASE OF BIG TIMBER POSSIBLE MOUNTAIN WAVES. BIG TIMBER/S WIND
SPEEDS WERE IN THE 50S EARLY THIS MORNING. THERE WAS DRAINAGE
OCCURRING OUT OF THE MAIN BOULDER...AND IR SATELLITE IMAGERY
SHOWED WAVE CLOUDS OVER THE AREA. EXPECT THIS SETUP TO CONTINUE
DURING THE MORNING HOURS BEFORE MIXING TAKES OVER IN THE
AFTERNOON. THUS WILL CONTINUE THE HIGH WIND WARNING FOR THIS AREA.
FOR THE GAP FLOW AREAS...WINDS WERE NOT AS STRONG THIS
MORNING...AND PRESSURE FALLS WERE BACK OVER W MT. THE GFS AND WRF
BROUGHT GOOD PRESSURE FALLS INTO THE KLVM AREA BY 18Z. COUNTING ON
THE FALLS TO REORIENT THE PRESSURE GRADIENT TO FAVOR STRONG GAP
FLOW WINDS THIS MORNING SO WILL LEAVE HIGH WIND WARNING IN PLACE.
REMAINDER OF THE AREA WILL BE BREEZY TO WINDY TODAY...ESPECIALLY
THIS AFTERNOON DUE TO MIXING. THE STRONGEST WINDS WILL BE W OF
KBIL.
SHORTWAVE ENERGY...PACIFIC MOISTURE AND A COLD FRONT WILL APPROACH
THE AREA TODAY. MOISTURE COULD BE SEEN IN SATELLITE IMAGERY THIS
MORNING. THESE FACTORS WILL BRING A SLIGHT CHANCE OF SNOW SHOWERS
TO THE WESTERN MOUNTAINS...OTHERWISE IT WILL BE A PARTLY CLOUDY
DAY. MIXDOWNS SUPPORTED TEMPERATURES IN THE 40S TO LOWER 50S.
THE WAVE AND FRONT WILL MOVE THROUGH THE AREA TONIGHT BRINGING
MOUNTAIN SNOW AND A SLIGHT CHANCE OF RAIN AND SNOW SHOWERS TO THE
PLAINS. TIME-HEIGHTS FOR THE SW MOUNTAINS WERE UNSTABLE SO EXPECT
A FEW INCHES OF SNOW FOR THE HIGH TERRAIN. THE BREEZY TO WINDY
CONDITIONS WILL CONTINUE ACROSS THE AREA BUT DO NOT ANTICIPATE ANY
HIGHLIGHTS. THE SYSTEM WILL MOVE OUT OF THE AREA EARLY ON TUE WITH
SOME LINGERING PRECIPITATION CHANCES OVER AND NEAR THE MOUNTAINS.
IT WILL REMAIN WINDY ON TUE. TEMPERATURES WILL BE SIMILAR TO
TODAY/S READINGS. BRIEF UPPER RIDGING WILL BUILD OVER THE AREA TUE
AFTERNOON BEFORE ANOTHER SHORTWAVE AND COLD FRONT MOVE INTO THE
REGION TUE NIGHT. THERE WILL BE A BAND OF FRONTOGENESIS ALONG THE
FRONT BUT NOT A LOT OF MOISTURE OVER THE PLAINS SO LOWERED THE
POPS. THE MOUNTAINS WILL HAVE THE BEST CHANCE OF PRECIPITATION.
ANOTHER LEE TROUGH WILL PRECEDE THE FRONT TUE NIGHT WHICH WILL
BRING INCREASING WINDS TO KLVM. HAVE INCREASED THE WIND SPEEDS FOR
THIS PERIOD. WILL HAVE TO SEE IF ANY HIGHLIGHTS WILL BE NEEDED AS
ARRIVAL OF FRONT WILL CUT OFF STRONG GAP FLOW WINDS LATE TUE
NIGHT. ARTHUR
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
WEDNESDAY WILL SEE THE WIND EPISODE CONTINUE AND SPREAD INTO THE
PLAINS AS AN EARLY MORNING COLD FRONT IS FOLLOWED BY STRONG
MOMENTUM ALOFT AND AN UNSTABLE AIRMASS. DRY AIR ROTATING AROUND AN
UPPER LOW IN SASKATCHEWAN WILL LIMIT SHOWER ACTIVITY BUT IT
SHOULD PERMIT SOME SUNSHINE WHICH WILL KEEP TEMPERATURES AROUND
THE 40 DEGREE MARK AND ALLOW FOR STEEP LOW LEVEL LAPSE RATES
SUPPORTING MIXING. AS THE WEDNESDAY SYSTEM MOVES EAST WEDNESDAY
NIGHT ANOTHER SURGE OF ENERGY MOVES INTO NORTHWEST MONTANA IN
NORTHWEST FLOW ALOFT. SHORTWAVE RIDGING BEHIND THE FIRST SYSTEM
SLOWS HEIGHT FALLS OVER THE REGION AND PATTERN BECOMES LESS
PROGRESSIVE. INCREASING NORTHWEST FLOW ALOFT CAUSES THE NEXT
SURFACE WAVE TO TRANSLATE ACROSS MONTANA AS OPPOSED TO CANADA AND
THIS WILL BRING A BETTER CHANCE FOR SNOW WITH COLDER TEMPERATURES
MOVING INTO THE AREA.
THURSDAY NIGHT AND FRIDAY IS ONE OF THE PERIODS THAT HAS A BETTER
CHANCE TO PRODUCE SNOWFALL AS THE COLDEST AIR PUSHES UP AGAINST
THE HIGHER TERRAIN AND UPSLOPE WORKS WITH AN UNSTABLE AND MOIST
ATMOSPHERE. SURFACE PRESSURE IS NOT OVERLY DEEP AND MIDLEVEL
NORTHWEST FLOW CAUSES THE UPSLOPE ORIENTATION TO BE LESS THAN
IDEAL SO SIGNIFICANT SNOW IS HARDLY EXPECTED. BUT IT WILL BE A BIG
CHANGE FROM THE MILD AND WINDY WEATHER.
SATURDAY AND SUNDAY AN UPSTREAM RIDGE BEGINS TO BUILD OVER THE
PACIFIC NORTHWEST WHILE THE COLDER AIR IS REINFORCED OVER EASTERN
MONTANA BY NORTHWEST FLOW ALOFT. A BAND OF ISENTROPIC/FRONTOGENIC
PRECIPITATION IS EXPECTED OVER THE CENTRAL AND EASTERN ZONES WITH
THE WESTERN ZONES BEGINNING TO SEE KLONDIKE CHINOOK CONDITIONS.
MONDAY THE PATTERN BREAKS DOWN AS THE ENERGY MOVING ACROSS THE
CANADIAN ROCKIES DISPLACES THE COLD AIR FURTHER EAST. THIS WILL
BRING MODERATING TEMPERATURES AND DECREASE CHANCES FOR SNOW. AND
POSSIBLY MORE WIND FOR GAP FLOW AREAS.
TEMPERATURES WILL BE COLDEST FRIDAY NIGHT THROUGH SUNDAY WITH
HIGHS 30 OR LOWER AND MINIMUMS OF 5 TO 15...ROUGHLY 15 DEGREES
BELOW NORMAL. BORSUM
&&
.AVIATION...
STRONG AND GUSTY SOUTHWEST TO WEST WINDS ARE EXPECTED TO CONTINUE
ALONG THE FOOTHILLS TODAY...WITH GUSTS IN EXCESS OF 50 KNOTS
POSSIBLE. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL
ACROSS THE REGION...WITH THE EXCEPTION OF SOME MOUNTAIN SHOWER
ACTIVITY. THERE IS ALSO A CHANCE FOR SOME ISOLATED SHOWERS THIS
EVENING FROM BILLINGS WESTWARD ...WITH LOCALIZED REDUCTIONS IN
FLIGHT CONDITIONS POSSIBLE. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 049 030/048 033/044 025/038 020/030 011/027 012/030
1/N 21/N 32/W 12/J 34/J 32/J 22/J
LVM 051 029/046 032/043 020/035 017/029 004/025 010/031
1/N 32/J 42/W 23/J 44/J 22/J 22/J
HDN 051 029/053 032/046 023/039 018/033 009/029 009/031
1/N 21/N 32/W 12/J 24/J 32/J 22/J
MLS 047 027/045 029/044 020/035 017/026 006/022 008/024
0/B 11/B 32/W 12/J 23/J 22/J 12/J
4BQ 052 029/051 029/047 023/039 018/032 008/028 009/029
0/B 21/N 12/W 02/J 24/J 22/J 22/J
BHK 045 025/042 023/043 016/033 012/027 002/020 003/022
0/N 10/N 22/W 11/B 23/J 22/J 12/J
SHR 052 026/047 028/047 018/039 016/030 005/028 008/031
1/N 21/N 14/W 12/J 34/J 42/J 32/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...HIGH WIND WARNING IN EFFECT UNTIL 6 PM MST THIS EVENING FOR
ZONES 28-41-63-65-66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
904 AM MST MON FEB 17 2014
.UPDATE...
CONDITIONS HAVE BECOME A BIT MORE FAVORABLE FOR WINDS AT
LIVINGSTON THIS MORNING...WITH A BACKED GRADIENT DUE TO WESTERN
AND CENTRAL MT PRESSURE FALLS...AND WINDS HAVE INCREASED AS A
RESULT HERE AND DECREASED AT SUCH PLACES AS BIG TIMBER...HARLOWTON
AND JUDITH GAP. ONSET OF COLD ADVECTION AND DESTABILIZING WILL
ALLOW FOR WINDS TO INCREASE AGAIN THRU SWEET GRASS AND WHEATLAND
COUNTIES THIS AFTERNOON...SO THE CURRENT LULL IS ONLY TEMPORARY.
AM A BIT CONCERNED THAT GUSTS COULD PUSH 60 MPH IN WHEATLAND
COUNTY LATER TODAY WITH MIXING BUT THERE ARE A COUPLE FACTORS
WORKING AGAINST THIS...PRESSURE FALLS TO OUR SOUTH IN ID/WY AND
SOME SYNOPTIC SCALE ASCENT AS SHORTWAVE ENERGY APPROACHES FROM
THE WEST. SO WILL KEEP GUSTS LIMITED TO 50-55 MPH AT HARLOWTON AND
JUDITH GAP. WINDS WILL REMAIN STRONG THRU TONIGHT. WILL MAKE NO
CHANGES TO THE WIND HIGHLIGHTS FOR LIVINGSTON...NYE AND BIG
TIMBER. SURPRISE SURPRISE ANOTHER WINDY DAY FOLKS.
THERE IS QUITE A BIT OF WIND FLOW OVER THE CREST OF THE BIG HORNS
THIS MORNING AND BURGESS JCT WINDS WERE GUSTING NEAR 50 MPH AT 8
AM. RAP SUGGESTS THAT THRU MIXING SHERIDAN WILL SEE INCREASED WSW
GUSTS LATER THIS MORNING...BUT FEEL THAT WITHOUT STRONGER DESCENT
WE WILL NOT SEE THAT DEGREE OF WIND PUSH DOWN THE LEE OF THE MTNS.
THAT BEING SAID WILL NEED TO WATCH THE SHERIDAN AREA TODAY AND
HAVE RAISED WIND SPEEDS TO SHOW GUSTS TO 30 MPH TODAY.
OTHER THAN WIND THERE ARE NO OTHER FORECAST ISSUES TODAY. TEMPS
WILL RISE TO THE 40S OR LOW 50S WITH PERSISTENT DOWNSLOPE
CONDITIONS AND A FRONTAL PASSAGE LATE. SNOW SHOWERS WILL INCREASE
OVER THE WEST SLOPES AFTER 00Z.
JKL
&&
.SHORT TERM...VALID FOR TDY AND TUE...
UPPER JET ENERGY WILL CONTINUE TO MOVE ACROSS THE AREA CREATING A
FAST WESTERLY FLOW THROUGH THE FORECAST PERIOD. ENSEMBLE
SITUATIONAL AWARENESS TABLE CONTINUED TO HIGHLIGHT ANOMALOUSLY
HIGH MID LEVEL WINDS WITH SOME ANOMALIES SHOWING UP AT 850 MB AS
WELL. FORECAST CHALLENGE CONTINUES TO BE HOW MUCH WIND WILL REACH
THE GROUND. HOWEVER...FOR THIS MORNING IN KLVM...NYE AND BIG
TIMBER...THE CAUSATIVE FACTORS FOR WINDS WILL BE GAP FLOW AND IN
THE CASE OF BIG TIMBER POSSIBLE MOUNTAIN WAVES. BIG TIMBER/S WIND
SPEEDS WERE IN THE 50S EARLY THIS MORNING. THERE WAS DRAINAGE
OCCURRING OUT OF THE MAIN BOULDER...AND IR SATELLITE IMAGERY
SHOWED WAVE CLOUDS OVER THE AREA. EXPECT THIS SETUP TO CONTINUE
DURING THE MORNING HOURS BEFORE MIXING TAKES OVER IN THE
AFTERNOON. THUS WILL CONTINUE THE HIGH WIND WARNING FOR THIS AREA.
FOR THE GAP FLOW AREAS...WINDS WERE NOT AS STRONG THIS
MORNING...AND PRESSURE FALLS WERE BACK OVER W MT. THE GFS AND WRF
BROUGHT GOOD PRESSURE FALLS INTO THE KLVM AREA BY 18Z. COUNTING ON
THE FALLS TO REORIENT THE PRESSURE GRADIENT TO FAVOR STRONG GAP
FLOW WINDS THIS MORNING SO WILL LEAVE HIGH WIND WARNING IN PLACE.
REMAINDER OF THE AREA WILL BE BREEZY TO WINDY TODAY...ESPECIALLY
THIS AFTERNOON DUE TO MIXING. THE STRONGEST WINDS WILL BE W OF
KBIL.
SHORTWAVE ENERGY...PACIFIC MOISTURE AND A COLD FRONT WILL APPROACH
THE AREA TODAY. MOISTURE COULD BE SEEN IN SATELLITE IMAGERY THIS
MORNING. THESE FACTORS WILL BRING A SLIGHT CHANCE OF SNOW SHOWERS
TO THE WESTERN MOUNTAINS...OTHERWISE IT WILL BE A PARTLY CLOUDY
DAY. MIXDOWNS SUPPORTED TEMPERATURES IN THE 40S TO LOWER 50S.
THE WAVE AND FRONT WILL MOVE THROUGH THE AREA TONIGHT BRINGING
MOUNTAIN SNOW AND A SLIGHT CHANCE OF RAIN AND SNOW SHOWERS TO THE
PLAINS. TIME-HEIGHTS FOR THE SW MOUNTAINS WERE UNSTABLE SO EXPECT
A FEW INCHES OF SNOW FOR THE HIGH TERRAIN. THE BREEZY TO WINDY
CONDITIONS WILL CONTINUE ACROSS THE AREA BUT DO NOT ANTICIPATE ANY
HIGHLIGHTS. THE SYSTEM WILL MOVE OUT OF THE AREA EARLY ON TUE WITH
SOME LINGERING PRECIPITATION CHANCES OVER AND NEAR THE MOUNTAINS.
IT WILL REMAIN WINDY ON TUE. TEMPERATURES WILL BE SIMILAR TO
TODAY/S READINGS. BRIEF UPPER RIDGING WILL BUILD OVER THE AREA TUE
AFTERNOON BEFORE ANOTHER SHORTWAVE AND COLD FRONT MOVE INTO THE
REGION TUE NIGHT. THERE WILL BE A BAND OF FRONTOGENESIS ALONG THE
FRONT BUT NOT A LOT OF MOISTURE OVER THE PLAINS SO LOWERED THE
POPS. THE MOUNTAINS WILL HAVE THE BEST CHANCE OF PRECIPITATION.
ANOTHER LEE TROUGH WILL PRECEDE THE FRONT TUE NIGHT WHICH WILL
BRING INCREASING WINDS TO KLVM. HAVE INCREASED THE WIND SPEEDS FOR
THIS PERIOD. WILL HAVE TO SEE IF ANY HIGHLIGHTS WILL BE NEEDED AS
ARRIVAL OF FRONT WILL CUT OFF STRONG GAP FLOW WINDS LATE TUE
NIGHT. ARTHUR
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
WEDNESDAY WILL SEE THE WIND EPISODE CONTINUE AND SPREAD INTO THE
PLAINS AS AN EARLY MORNING COLD FRONT IS FOLLOWED BY STRONG
MOMENTUM ALOFT AND AN UNSTABLE AIRMASS. DRY AIR ROTATING AROUND AN
UPPER LOW IN SASKATCHEWAN WILL LIMIT SHOWER ACTIVITY BUT IT
SHOULD PERMIT SOME SUNSHINE WHICH WILL KEEP TEMPERATURES AROUND
THE 40 DEGREE MARK AND ALLOW FOR STEEP LOW LEVEL LAPSE RATES
SUPPORTING MIXING. AS THE WEDNESDAY SYSTEM MOVES EAST WEDNESDAY
NIGHT ANOTHER SURGE OF ENERGY MOVES INTO NORTHWEST MONTANA IN
NORTHWEST FLOW ALOFT. SHORTWAVE RIDGING BEHIND THE FIRST SYSTEM
SLOWS HEIGHT FALLS OVER THE REGION AND PATTERN BECOMES LESS
PROGRESSIVE. INCREASING NORTHWEST FLOW ALOFT CAUSES THE NEXT
SURFACE WAVE TO TRANSLATE ACROSS MONTANA AS OPPOSED TO CANADA AND
THIS WILL BRING A BETTER CHANCE FOR SNOW WITH COLDER TEMPERATURES
MOVING INTO THE AREA.
THURSDAY NIGHT AND FRIDAY IS ONE OF THE PERIODS THAT HAS A BETTER
CHANCE TO PRODUCE SNOWFALL AS THE COLDEST AIR PUSHES UP AGAINST
THE HIGHER TERRAIN AND UPSLOPE WORKS WITH AN UNSTABLE AND MOIST
ATMOSPHERE. SURFACE PRESSURE IS NOT OVERLY DEEP AND MIDLEVEL
NORTHWEST FLOW CAUSES THE UPSLOPE ORIENTATION TO BE LESS THAN
IDEAL SO SIGNIFICANT SNOW IS HARDLY EXPECTED. BUT IT WILL BE A BIG
CHANGE FROM THE MILD AND WINDY WEATHER.
SATURDAY AND SUNDAY AN UPSTREAM RIDGE BEGINS TO BUILD OVER THE
PACIFIC NORTHWEST WHILE THE COLDER AIR IS REINFORCED OVER EASTERN
MONTANA BY NORTHWEST FLOW ALOFT. A BAND OF ISENTROPIC/FRONTOGENIC
PRECIPITATION IS EXPECTED OVER THE CENTRAL AND EASTERN ZONES WITH
THE WESTERN ZONES BEGINNING TO SEE KLONDIKE CHINOOK CONDITIONS.
MONDAY THE PATTERN BREAKS DOWN AS THE ENERGY MOVING ACROSS THE
CANADIAN ROCKIES DISPLACES THE COLD AIR FURTHER EAST. THIS WILL
BRING MODERATING TEMPERATURES AND DECREASE CHANCES FOR SNOW. AND
POSSIBLY MORE WIND FOR GAP FLOW AREAS.
TEMPERATURES WILL BE COLDEST FRIDAY NIGHT THROUGH SUNDAY WITH
HIGHS 30 OR LOWER AND MINIMUMS OF 5 TO 15...ROUGHLY 15 DEGREES
BELOW NORMAL. BORSUM
&&
.AVIATION...
STRONG AND GUSTY SOUTHWEST TO WEST WINDS ARE EXPECTED TO CONTINUE
ALONG THE FOOTHILLS TODAY...WITH GUSTS IN EXCESS OF 50 KNOTS
POSSIBLE. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL
ACROSS THE REGION...WITH THE EXCEPTION OF SOME MOUNTAIN SHOWER
ACTIVITY. THERE IS ALSO A CHANCE FOR SOME ISOLATED SHOWERS THIS
EVENING FROM BILLINGS WESTWARD ...WITH LOCALIZED REDUCTIONS IN
FLIGHT CONDITIONS POSSIBLE. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 049 030/048 033/044 025/038 020/030 011/027 012/030
1/N 21/N 32/W 12/J 34/J 32/J 22/J
LVM 051 029/046 032/043 020/035 017/029 004/025 010/031
1/N 32/J 42/W 23/J 44/J 22/J 22/J
HDN 051 029/053 032/046 023/039 018/033 009/029 009/031
1/N 21/N 32/W 12/J 24/J 32/J 22/J
MLS 047 027/045 029/044 020/035 017/026 006/022 008/024
0/B 11/B 32/W 12/J 23/J 22/J 12/J
4BQ 052 029/051 029/047 023/039 018/032 008/028 009/029
0/B 21/N 12/W 02/J 24/J 22/J 22/J
BHK 045 025/042 023/043 016/033 012/027 002/020 003/022
0/N 10/N 22/W 11/B 23/J 22/J 12/J
SHR 052 026/047 028/047 018/039 016/030 005/028 008/031
1/N 21/N 14/W 12/J 34/J 42/J 32/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...HIGH WIND WARNING IN EFFECT UNTIL 6 PM MST THIS EVENING FOR
ZONES 41-65-66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
632 PM EST TUE FEB 18 2014
.SYNOPSIS...
LIGHT SNOW WILL COME TO AN END THIS EVENING AS WEAK HIGH PRESSURE
BUILDS INTO THE REGION. ANOTHER ROUND OF VERY LIGHT SNOW OR
FLURRIES IS EXPECTED ACROSS THE AREA ON WEDNESDAY AS ADDITIONAL
WEAK LOW PRESSURE CROSSES THE REGION. A STRONGER STORM SYSTEM WILL
AFFECT THE AREA THURSDAY NIGHT INTO FRIDAY WITH MILDER
TEMPERATURES ALONG WITH A MIX OF WINTRY PRECIPITATION AND LOCALLY
GUSTY WINDS.
&&
.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
AS OF 534 PM EST TUESDAY...FORECAST IN GOOD SHAPE AS WE HEAD INTO
THE EVENING HOURS. DID OPT TO CUT BACK ON POPS RATHER QUICKLY THIS
EVENING PER LATEST RAP PROGS WHICH APPEARS TO BE HANDLING CURRENT
SITUATION QUITE WELL BASED OFF RECENT RADAR TRENDS. THUS EXPECT
MOST SNOWFALL TO BE OVER IN MOST AREAS BY 8 PM IF NOT SOONER IN
THE CASE OF NORTHERN NEW YORK. TEMPERATURES STILL HOLDING IN THE
LOWER TO MID 20S IN MOST SPOTS AS OF THE 5 PM HOUR WITH ONLY A
SMALL DOWNWARD TREND OVERNIGHT DUE TO CONTINUED S/SW FLOW AND AT
LEAST SOME CLOUD COVER HERE AND THERE THROUGH THE NIGHT. PRIOR
DISCUSSION FOLLOWS. HAVE A GREAT EVENING.
PRIOR DISCUSSION...
PERIOD OF ACCUMULATING SNOW WILL CONTINUE THRU 23-00Z ASSOCIATED
WITH UPPER LOW...WHICH IS CURRENTLY MVG ENEWD ACROSS THE NRN
ADIRONDACKS AT 2030Z. ANTICIPATE ANOTHER 1-2" ACROSS NRN VT AND
NRN NY BEFORE ENDING. ATLANTIC MOISTURE ASSOCIATED WITH SECONDARY
LOW SPINNING UP ACROSS RI AND SERN MA NOT REALLY BEING TAPPED AT
THE MOMENT. THAT SAID...POTENTIAL STILL EXISTS FOR SOME
MOISTURE/UPSLOPE ENHANCEMENT ACROSS S-CENTRAL VT ALLOWING FOR
LOCALLY HIGHER SNOW TOTALS OF 3-6". ANTICIPATE THE HIGHEST SNOW
TOTALS ALONG THE ERN SLOPES OF THE GREEN MTNS FROM LUDLOW TO
BETHEL AND ACROSS THE SUMMITS. MAINTAINED WINTER WX ADVISORY FOR
RUTLAND/WINDSOR/ORANGE THRU 02Z. SNOW COVERED ROADS AREAWIDE AND
PERIODS OF 1/2 MILE VSBY WILL MAKE FOR SOME TRAVEL SLOWDOWNS
DURING THE EVENING COMMUTE...WITH SOMEWHAT WORSE CONDITIONS ACROSS
S-CENTRAL VT.
ANTICYCLONIC FLOW ALOFT AND NARROW SFC RIDGE AXIS BUILDS INTO NRN
NY BY 03Z AND ACROSS VT BY 06Z. THIS SHOULD RESULT IN SUBSIDENCE
AND QUICK END TO ACCUMULATING SNOW THIS EVENING. KEPT SOME CHANCE
POPS ACROSS FAR ERN VT THRU ABOUT MIDNIGHT. NAM/RAP MODEL RH
PROFILES SUGGEST SOME CLEARING OVERNIGHT WITHIN THE RIDGE AXIS.
WITH LIGHT SFC WINDS AND PARTIAL CLEARING...LOWS SHOULD DRO
&&
.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 346 PM EST TUESDAY...PROGRESSIVE UPPER FLOW PATTERN CONTINUES
ACROSS THE CENTRAL AND ERN CONUS. NEXT FAST-MOVING
TROUGH...CURRENTLY ACROSS THE UPPER MS VALLEY...IS EXPECTED TO
REACH THE ERN GREAT LAKES REGION BY 12Z WEDNESDAY...AND THEN THRU
THE NORTH COUNTRY BETWEEN 18-00Z. PERIOD OF MID-LEVEL UVV
TRANSLATES EWD ACROSS THE NORTH COUNTRY MIDDAY THRU LATE AFTERNOON
WEDNESDAY...BRINGING A PERIOD OF SNOW SHOWER ACTIVITY ACROSS THE
REGION. LOOKING FOR SUB-ADVISORY SNOWFALL ACCUMULATIONS...GENERALLY
1-3"...HIGHEST AWAY FROM THE CHAMPLAIN VALLEY (WHERE SOME LOCAL
SHADOWING EFFECTS APPEAR LIKELY). TROUGH PASSAGE AFTER 00Z SHOULD
BRING AN END TO THE SNOWFALL BY LATE EVENING FOR MOST SECTIONS.
ALSO...AIR MASS WILL CONTINUE TO MODERATE WEDNESDAY. DESPITE
MOSTLY CLOUDY TO CLOUDY CONDITIONS...HIGH TEMPERATURES WILL
GENERALLY REACH THE 33-37F. ABOVE FREEZING NEAR- SURFACE LAYER IS
MARGINAL FOR ANY VALLEY RAIN...WITH ABOVE FREEZING DEPTH GENERALLY
800-900 FT. WILL KEEP AS GENERALLY SNOW...BUT MAY SEE SOMEWHAT
LOWER VALLEY ACCUMULATIONS DUE TO WARMER SFC
CONDITIONS...ESPECIALLY ON PAVEMENT.
NEXT MOBILE SHORTWAVE RIDGE TRAVERSES THE REGION WEDNESDAY NIGHT
WITH GENERALLY DRY WEATHER CONDITIONS. VARIABLE CLOUDY CONDITIONS
EXPECTED...AND WILL HELP KEEP TEMPERATURES GENERALLY IN THE 20S FOR
OVERNIGHT LOWS WEDNESDAY NIGHT.
CONTINUED QUIET FOR THURSDAY. RIDGE AXIS SLIDES EAST OF THE CT RIVER
VALLEY AND WILL ALLOW FOR A DEVELOPING LIGHT (5-10 MPH) RETURN FLOW.
PARTLY SUNNY CONDITIONS ANTICIPATED BASED ON SOME HIGHER MID-UPR
LEVEL RH ACROSS THE REGION. 850MB TEMPS CLIMB TO NEAR 0C BY 00Z
FRIDAY. SHOULD SEE MOST LOCATIONS IN THE 37-42F RANGE FOR DAYTIME
HIGHS THURSDAY AFTN.
STRONGER/HIGH AMPLITUDE MID-LEVEL TROUGH ACROSS THE CENTRAL MS VALLEY
THURSDAY NIGHT RESULTS IN RAPIDLY DEEPENING LOW PRESSURE ACROSS THE
GREAT LAKES REGION (976MB PER 12Z GFS AT 06Z FRIDAY). STRONG SLY
LOW-LEVEL JET DEVELOPS DURING THURSDAY NIGHT...WITH 60KT AT 850MB BY
DAYBREAK FRIDAY ACROSS NRN NY AND EWD INTO THE CHAMPLAIN VALLEY.
STRONG WARM FRONTAL ASCENT WILL BRING STRATIFORM PRECIPITATION TO
THE REGION...ESPECIALLY AFTER MIDNIGHT THURSDAY NIGHT. A BIT OF
ELEVATED CAPE ALSO PRESENT IN NAM FORECAST SOUNDINGS AROUND 10-12Z
FRIDAY...SO MAY SEE SOME EMBEDDED CONVECTIVE ELEMENTS WITH HVY
PRECIPITATION. WILL CONTINUE TO SHOW 60-80 POPS AFTER 06Z. ABOVE
FREEZING TEMPS LIKELY IN THE CHAMPLAIN VALLEY. HOWEVER...IT APPEARS
BASED ON MODEL SOUNDINGS THAT TEMPS ELSEWHERE WILL BE BELOW FREEZING
NEAR THE SFC WITH FAVORABLE PROFILES FOR A PERIOD OF SLEET AND
POSSIBLE FREEZING RAIN. THIS MAY HAVE SOME TRAVEL IMPACT DURING THE
PRE-DAWN HRS INTO THE EARLY MORNING COMMUTE. WILL CONTINUE TO SHOW
MIXED PRECIPITATION IN THE FCST GRIDS. ALSO LOOKING AT LOCALLY
STRONG AND GUSTY WINDS...WITH SOUTH GUSTS 25-35 MPH...PERHAPS A BIT
STRONGER RIGHT ALONG THE WRN SLOPES OF THE GREEN MOUNTAINS WITH
DOWNSLOPE EFFECTS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 315 PM EST TUESDAY...A CHANGEABLE WX PATTERN UPCOMING FROM
MID/UPPER LVL RIDGE ACRS THE EASTERN CONUS ON FRIDAY/SATURDAY
TO A DEEP TROF AND ARCTIC AIR BY EARLY NEXT WEEK. FCST CHALLENGE
ON FRIDAY WL BE PTYPE...WINDS...AND TEMPS...FOLLOWED BY TIMING OF
COOLING FOR FRIDAY NIGHT INTO SATURDAY. STILL SOME UNCERTAINTY ON
MAGNITUDE OF MID/UPPER LVL TROF NEXT WEEK AND AMOUNT OF LLVL CAA
ACRS OUR CWA.
BOTH GFS/NAM SHOW VERY STRONG 925MB TO 850MB WINDS OF 45 TO 65
KNOTS ON FRIDAY MORNING...WHICH WL RESULT IN STRONG LOCALIZED SE
DOWNSLOPE WINDS OF 30 TO 40 KNOTS. THESE WINDS WL QUICKLY SHIFT TO
THE SOUTHWEST AS FROPA OCCURS DURING THE LATE MORNING/EARLY AFTN
HRS...WITH STRONGEST PRES RISE COUPLET ACRS THE SLV. THINKING THIS
WL RESULT IN GUSTY SOUTHWEST WINDS ACRS THE SLV/DACKS BTWN 30 AND 40
KNOTS ON FRIDAY MIDDAY.
ALL MODELS AGREE ON PRECIP COMING IN TWO SEPARATE WAVES...FIRST
ASSOCIATED WITH WAA EARLY FRIDAY MORNING...FOLLOWED BY FROPA
PRECIP BTWN 12Z AND 21Z FRIDAY. THE PRECIP ASSOCIATED WITH THE
COLD FRNT WL BE A 2 TO 5 HR PRECIP EVENT WITH GENERAL QPF BTWN
0.25 AND 0.50" ACRS OUR CWA. EXPECTING SFC TEMPS TO BE MAINLY
ABOVE FREEZING WITH SFC FRNT...RESULTING IN RAIN...BUT SOME
POCKETS OF FREEZING RAIN WL BE POSSIBLE IN THE COLDER VALLEYS OF
CENTRAL/EASTERN VT...INCLUDING THE NEK ON FRIDAY. PROGGED 85H
TEMPS WARM BTWN 6C AND 8C PRIOR TO FROPA...SUGGESTING TEMPS WELL
INTO THE 40S...WITH EVEN A FEW L50S POSSIBLE AROUND RUTLAND AND IN
THE CANTON/POTSDAM AREAS ON FRIDAY MORNING. TEMPS ACRS THE HIGHER
TRRN WL COOL QUICKLY ON FRIDAY AFTN...WITH STRONG 85H CAA
DEVELOPING ON GUSTY WINDS.
SATURDAY-TUESDAY...TEMPS WL SLOWLY RETURN TO BLW NORMAL BY EARLY
NEXT WEEK AS MID/UPPER LVL TROF REDEVELOPS ACRS OUR CWA. GIVEN
SOUTHWEST FLW ALOFT ON SATURDAY AND PROGGED 85H TEMPS BTWN -4C AND
-6C...TEMPS SHOULD WARM INTO THE 40S WARMER VALLEYS AND MID 30S
MTNS/NEK. WARMEST TEMPS WL BE AROUND VSF DUE TO DOWNSLOPE WARMING
ON WESTERLY FLW. SECONDARY COLD FRNT ARRIVES ON SUNDAY...WITH
LATEST GFS SHOWING A RIBBON OF ENHANCED FGEN FORCING ALONG WITH
DEEPER 850 TO 500MB RH. HAVE INCLUDED CHC POPS FOR SAT NIGHT INTO
SUNDAY...BUT OVERALL QPF/SNOWFALL WL BE LIGHT. ADDITIONAL S/W
ENERGY AND ANOTHER FRNT PUSHES ACRS OUR CWA LATE SUNDAY INTO
MONDAY WITH ANOTHER SURGE OF COLDER TEMPS. PROGGED 85H TEMPS DROP
TO AROUND -20C BY 12Z MONDAY OFF BOTH THE GFS/ECMWF...SUPPORTING
HIGHS ONLY IN THE TEENS MTNS TO L/M 20S VALLEYS WITH ONLY A SLIGHT
CHC FOR MAINLY MTN SNOW SHOWERS. THE 6 TO 10 DAY OUTLOOK FROM CPC
SHOWS BLW NORMAL TEMPS AND PRECIP. AS ALWAYS THE DEPTH AND
POSITION OF THE MID/UPPER LVL TROF AXIS WL HAVE TO BE WATCHED
CLOSELY...ALONG WITH TIMING OF INDIVIDUAL S/W`S IN THE
NORTHERN/SOUTHERN STREAMS FOR NEXT WEEK AND DEVELOPMENT OF LOW
PRES ACRS THE EASTERN CONUS.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 00Z THURSDAY...LIGHT SNOW AND ANY MVFR/IFR ASSOCIATED WITH
IT WILL END THIS EVENING...GIVING WAY TO VFR CONDITIONS OVERNIGHT
AND INTO WEDNESDAY MORNING. WINDS WILL BE MAINLY LIGHT (5-8 KNOTS
OR LESS) OUT OF THE SOUTH. NEXT WEAK LOW PRESSURE SYSTEM WILL
AFFECT THE REGION LATE WEDNESDAY MORNING AND WEDNESDAY AFTERNOON.
LIGHT PRECIPITATION WILL OVERSPREAD THE AREA...POSSIBLY BEGINNING
AS LIGHT RAIN OR A MIX OF RAIN AND SNOW...BEFORE TRANSITIONING
OVER TO A PERIOD OF LIGHT SNOW WITH WIDESPREAD IFR CONDITIONS
LIKELY. THE HEAVIEST SNOW WITH GREATEST RISK OF REDUCTIONS TO
CEILINGS AND VISIBILITIES WILL OCCUR BETWEEN 18Z AND 00Z. MSS WILL
BE LEAST IMPACTED. WINDS CONTINUE OUT OF THE SOUTH AROUND 10 KNOTS
OR SO.
OUTLOOK 00Z THURSDAY THROUGH SUNDAY...
00Z THURSDAY THROUGH 12Z THURSDAY...LIGHT SNOW AND ASSOCIATED IFR
WILL END THURSDAY EVENING AS LOW PRESSURE PULLS AWAY GIVING WAY TO
IMPROVING CONDITIONS OVERNIGHT.
12Z THURSDAY THROUGH 00Z FRIDAY...VFR UNDER HIGH PRESSURE.
00Z FRIDAY THROUGH 06Z SATURDAY...VFR TRENDING MVFR WITH PERIODS
OF IFR POSSIBLE IN RAIN AND MIXED PRECIPITATION AS LOW PRESSURE
TRACKS TO OUR NORTHWEST. GUSTY WINDS AND LOW LEVEL WIND SHEAR LIKELY.
06Z SATURDAY ONWARD...TRENDING VFR UNDER BUILDING HIGH PRESSURE.
&&
.EQUIPMENT...
DAMAGED EQUIPMENT HAS RESULTED IN AN AUDIBLE HUM ON THE MOUNT
ASCUTNEY NOAA WEATHER RADIO BROADCAST (WXM-44). OUR TECHNICIANS
ARE AWARE OF THE PROBLEM AND WILL RESOLVE THE ISSUE AS QUICKLY AS
POSSIBLE. REPAIRS MAY INVOLVE COORDINATION AND ACCESS BY
TELCO...INCLUDING PARTS ACQUISITION. THIS MAY TAKE 1-2 DAYS TO
RESOLVE. IN THE MEANTIME...WE APOLOGIZE FOR ANY DIFFICULTIES IN
HEARING THE BROADCAST FROM MOUNT ASCUTNEY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
VTZ010>012-019.
NY...NONE.
&&
$$
SYNOPSIS...JMG
NEAR TERM...BANACOS/JMG
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...MUCCILLI
EQUIPMENT...BTV
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1150 PM CST SUN FEB 16 2014
.UPDATE...
ISSUED AT 1150 PM CST SUN FEB 16 2014
SNOWFALL ACROSS THE FA HAS BECOME LESS ORGANIZED AS WE ARE
IN BETWEEN STRONGER FORCING MECHANISMS. ANOTHER STRONGER BAND OF
SNOW (NOW JUST WEST OF JAMESTOWN) WILL CONTINUE TO PROPAGATE
EAST/NORTHEAST PRODUCING ANOTHER 1-3 INCHES FROM ITS CURRENT
LOCATION INTO NW MN. THE LATEST RAP GUIDANCE SUGGESTS ANOTHER
STRONGER BAND OF SNOWFALL WILL AFFECT WC MN TOWARD 12Z (ALTHOUGH
THE HEAVIEST SNOWFALL WOULD BE JUST EAST OF THE FA). DID NOT MAKE
MUCH CHANGE TO THE GRIDS AS THEY BASICALLY DEPICT THIS OUTCOME.
WINDS ALOFT ARE NOT MIXING VERY EFFICIENTLY...AND WILL TAME DOWN
THE BLOWING SNOW MENTION.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 319 PM CST SUN FEB 16 2014
SNOW AMOUNTS AND TIMING REMAINS THE ISSUE. 12Z MODELS AND SHORT
RANGE MODELS BACKED OFF ON TIMING OF MAIN SNOW BAND NOT ARRIVING
INTO THE RED RIVER VALLEY TIL 03-06Z AND EASTERN FCST AREA AFTER 06Z.
HRRR/RAP/18Z NAM CATCHES ONTO SNOW BANDS IN EASTERN MONTANA
DEVELOPING NORTH OF SURFACE LOW IN SOUTHEASTERN MONTANA AND NEAR
SHORT WAVE MOVING THRU MONTANA.
AHEAD OF THIS MAIN PRECIPITATION BAND IS INITIAL WARM ADVECTION
BAND THAT HAS BEEN MOVING EAST SLOWLY THRU WESTERN MANITOBA INTO
ERN ND. SNOW WITH THIS BAND LOOKS GOOD ON RADAR BUT OBS INDICATE
SNOWFALL PATCHY.
UNSURE EXACTLY HOW IT WILL EVOLVE...BUT MAIN UPPER TROUGH IS STILL
OVER WRN/CNTRL MONTANA AND ALL MODELS SHOW GOOD UPPER LEVEL
DIVERGENCE AHEAD OF IT AND DECENT 700 MB VERTICAL MOTION ALONG
WITH GOOD ISENTROPIC LIFT ALONG THE 290K SURFACE AHEAD OF SYSTEM
SPREADING INTO ERN ND/NW MN TONIGHT. SO DESPITE A BIT LATER START
STILL LOOKING FOR SAME IDEA IN TERMS OF SNOW TOTALS WITH 1-2 FAR
WEST TO 3 OR SO IN THE RED RIVER VALLEY TO 4-5 EASTERN FCST AREA.
SNOW WILL END IN THE RRV BY 12Z AND IN THE EAST BY 15Z. SOUTH-
SOUTHEAST WINDS GUSTY TO 30 KTS AT TIMES THIS AFTN WITH NAM BUFKIT
SOUNDINGS INDICATING PEAK MIXING IN LOWEST LAYERS 00Z-03Z IN THE
RED RIVER VALLEY WHERE 28-30 KTS AVAILABLE. PUBLIC REPORTS
INDICATE LOW LEVEL BLOWING SNOW/DRIFTING AND IN SPOTS POOR
VISIBILITY. WILL MAINTAIN THIS IDEA INTO THE EVENING. WHERE SNOW
DOES OCCUR WITH WIND NEAR BLIZZARD CONDITIONS WILL OCCUR BUT WINDS
APPEAR TO BE BLO BLIZZARD THRESHOLD UNLESS SOMETHING CHANGES. THUS
WINTER WX ADVISORY LOOKS GOOD...EVEN FOR WESTERN FCST AREA WHERE
SNOW TOTALS ARE BLO ADV THRESHOLDS FOR SNOWFALL.
CLEARING WILL MOVE IN MONDAY BEHIND THE FRONT WITH A WEST WIND AND
WARMER AIRMASS WITH HIGHS 30-35 IN MOST AREAS MON AFTN.
MONDAY NIGHT WILL BE MILD AS WELL WITH TEMPS HOLDING UP WITH WEST
BREEZE AND SOME MID LEVEL CLOUDS MOVING BACK IN AS A SHORT WAVE
MOVES EAST INTO NORTH DAKOTA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 319 PM CST SUN FEB 16 2014
AFOREMENTIONED SHORT WAVE WILL MOVE INTO MINNESOTA TUESDAY AND MAY
PRODUCE A LITTLE LIGHT SNOW IN THE LAKE OF THE WOODS REGION SO
KEPT LOW POPS. OTHERWISE PRETTY MILD AGAIN AS SFC FLOW REMAINS
WEST OR SOUTHWEST. HIGH PRESSURE DROPS IN TUES NIGHT...THEN
SOUTHEASTERLY FLOW WILL PICK UP WED AFTN AHEAD OF NEXT LOW TO MOVE
THROUGH SOUTHERN CANADA. WILL RESTRICT SOME POPS FOR LIGHT SNOW
AHEAD OF THIS SYSTEM TO THE AFTN IN NE ND.
OR WEDNESDAY NIGHT THROUGH SUNDAY..
LOW AMPLITUDE PROGRESSIVE FLOW BEGINS TO AMPLIFY THIS PERIOD. UPPER
RIDGE FORECAST TO REBUILD ALONG 140W WITH TROUGH NEAR 90W. BY THE
END OF THE PERIOD THE PATTERN SHIFTS EAST ABOUT 10 DEGREES PUTTING
THE NORTHERN PLAINS BACK INTO A COLDER PATTERN.
FOR WEDNESDAY EVENING INTO THURSDAY A STRONG LOW TRACKS SLOWLY JUST
NORTH OF THE INTERNATIONAL BORDER. LIGHT SNOWS FORECAST AHEAD OF THE
FRONT ON THURSDAY IN UPGLIDE ZONE...SIMILAR TO SYSTEM GOING THROUGH
REGION TODAY AND TONIGHT. MODELS IN FAIR AGREEMENT THAT WRAP AROUND
SNOWS WILL MOVE ACROSS MAINLY THE NORTHERN HALF OF THE REGION.
LIGHT SNOW WILL LINGER IN THE EASTERN CWFA INTO THURSDAY EVENING.
COLDER AIR PUSHES BACK ACROSS THE CWFA ON FRIDAY. FOR LATE FRIDAY
INTO SATURDAY A SYSTEM THAT THE MODELS HAVE TRENDED SOUTH WITH
BRUSHES THE FAR SOUTHERN CWFA. THE GFS/DGEX ARE MOST BULLISH WITH
QPF WHILE THE ECMWF KEEPS THE FA DRY UNDER SURFACE HIGH PRESSURE...
AND THE GEM HAS SOME -SN. MODELS TEND TO AGREE THERE WILL BE SOME
WEAK LOW - MID LEVEL ISENTROPIC UPGLIDE. WITH CYCLONIC FLOW IN
DEEPENING UPPER TROUGH FEEL LOW END POPS AT THIS POINT OK.
THE EXTENDED PERIOD ENDS COLD AND DRY...THE COMMON THEME FOR THIS
WINTER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1150 PM CST SUN FEB 16 2014
PERIODS OF SNOW...AND MVFR/IFR CONDITIONS...WILL CONTINUE THROUGH
THE NIGHTTIME HOURS. THESE CONDITIONS WILL END FROM WEST TO EAST
MONDAY MORNING...WITH VFR CONDITIONS MOVING IN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR NDZ006>008-
014>016-024-026>030-038-039-049-052>054.
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ001>004-007-
029-030-040.
WINTER WEATHER ADVISORY UNTIL 9 AM CST MONDAY FOR MNZ005-006-008-
009-013>017-022>024-027-028-031-032.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...EWENS/RIDDLE
AVIATION...TG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
956 PM EST TUE FEB 18 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE THROUGH WEDNESDAY MORNING. HIGH
PRESSURE WILL THEN WORK INTO THE AREA BY WEDNESDAY EVENING. A WARM
FRONT WILL LIFT THROUGH THE AREA THURSDAY MORNING AND A STRONG
COLD FRONT WILL MOVE THROUGH THE REGION THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
TEMPERATURES HAVE DROPPED OFF A BIT QUICKER THAN EXPECTED IN SOME
EASTERN COUNTIES WHERE WINDS ARE LIGHTER. BUT AS A COLD FRONT
APPROACHES THE WINDS SHOULD PICK UP THERE AND ALLOW READINGS TO
REBOUND AND BECOME MORE UNIFORM ACROSS THE FORECAST AREA. STILL
EXPECTING SHOWERS TO DEVELOP MAINLY SOUTH AND EAST OF I-71
OVERNIGHT AND QUICKLY MOVE EAST BY DAYBREAK. 00Z NAM HAS TRENDED A
BIT FURTHER SOUTH WITH THE PRECIPITATION ALTHOUGH NOT AS MUCH AS
RECENT RAP SOLUTIONS. STILL CONCERNED THAT HRRR RUNS HAVE BEEN
DEVELOPING PRECIPITATION FURTHER NORTH AND WEST ALTHOUGH HAVE NOT
FOLLOWED ALONG WITH THAT POSSIBILITY. NAM/RAP CONTINUE TO SHOW
ABUNDANT NEAR SURFACE MOISTURE LATE TONIGHT AS MOISTER AIR RIDES
OVER SNOW PACK. SO HAVE MAINTAINED PATCHY DRIZZLE AND FOG IN THE
FORECAST. TEMPERATURES FALLING TO NEAR OR SLIGHTLY BELOW FREEZING
IN THE FAR NORTHWEST COUNTIES LEADS TO A CONDITIONAL POSSIBILITY
FOR A PERIOD OF FREEZING DRIZZLE THERE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
THE WEAK COLD FRONT WILL CONTINUE TO PUSH THROUGH THE FA DURING
THE MORNING HOURS ON WEDNESDAY. DRIZZLE WILL GRADUALLY COME TO AN
END IN THE MORNING AND FOG WILL DISSIPATE. HIGH PRESSURE WILL WORK
INTO THE FA THROUGH THE DAY ON WEDNESDAY. ONLY EXPECT TEMPERATURES
TO BE SLIGHTLY COOLER ON WEDNESDAY THAN ON TUESDAY. DRY CONDITIONS
WILL CONTINUE INTO WEDNESDAY NIGHT.
THE LOW TEMPERATURE WEDNESDAY NIGHT WILL OCCUR DURING THE EVENING
HOURS AND THEN SLOWLY RISE FOR THE REMAINDER OF THE NIGHT. SOME
PATCHY FOG WILL AGAIN BE POSSIBLE WEDNESDAY NIGHT INTO THURSDAY
MORNING. A WARM FRONT WILL LIFT NORTHWARD DURING THE MORNING
HOURS ON THURSDAY. SHOWERS AND A FEW THUNDERSTORMS WILL ACCOMPANY
THIS FEATURE. A VERY BRIEF PERIOD OF FREEZING RAIN WILL BE
POSSIBLE ACROSS EXTREME NORTHERN PORTIONS OF THE FA DURING THE
EARLY DAYTIME HOURS ON THURSDAY.
THERE WILL BE SOME BREAKS IN THE PRECIPITATION DURING THE DAY ON
THURSDAY ESPECIALLY DURING THE AFTERNOON HOURS. TEMPERATURES WILL
CLIMB QUICKLY ALLOWING FOR THE WARMEST DAY OF THE WEEK. HIGH
TEMPERATURES ARE EXPECTED TO RANGE FROM THE MIDDLE 50S ACROSS THE
NORTHERN PORTIONS OF THE FA TO THE MIDDLE 60S ACROSS SOUTHERN
PORTIONS OF THE REGION. WINDS WILL INCREASE THROUGH THE DAY WITH
SOME WIND GUSTS UPWARDS OF 25 TO 35 MPH POSSIBLE DURING THE
AFTERNOON TO EVENING HOURS.
A COLD FRONT WILL APPROACH THE AREA THURSDAY EVENING AND MOVE
THROUGH THURSDAY NIGHT. A LINE OF STORMS IS EXPECTED TO DEVELOP
DURING THE EVENING HOURS. THE MAIN SEVERE THREAT WITH THIS FEATURE
WOULD BE DAMAGING WINDS HOWEVER AN ISOLATED TORNADO THREAT CANNOT
BE RULED OUT. THERE IS BETTER INSTABILITY ACROSS WESTERN PORTIONS
OF THE FA AND THEREFORE BELIEVE THE BETTER SEVERE THREAT WILL BE
ACROSS THE WESTERN HALF OF THE FA...HOWEVER CANNOT RULE OUT A MORE
ISOLATED SEVERE THREAT CONTINUING ACROSS THE EASTERN HALF OF THE
FA. CURRENT INDICATIONS ARE THAT THE BEST CHANCE FOR SEVERE
WEATHER ACROSS THE FA WOULD BE BETWEEN 23Z AND 04Z.
EVEN AFTER THE INITIAL SEVERE THREAT EXPECT MODERATE RAIN TO
CONTINUE ACROSS THE FA. AS THE COLD FRONT WORKS THROUGH AND COLDER
AIR WORKS INTO THE AREA A BRIEF PERIOD OF A RAIN SNOW MIX OR LIGHT
SNOW WILL BE POSSIBLE BEFORE PRECIPITATION COMES TO AN END.
EXPECTING LITTLE OR NO SNOW ACCUMULATION. WIDESPREAD RAINFALL
TOTALS WILL RANGE FROM A HALF INCH TO AN INCH HOWEVER HIGHER
AMOUNTS WILL BE POSSIBLE WITH THE THUNDERSTORM ACTIVITY. WITH THIS
PRECIPITATION COMBINED WITH THE THE SNOW MELT...FLOODING WILL BE
POSSIBLE ACROSS THE FA.
AS THE COLD FRONT MOVES THROUGH THE FA THURSDAY NIGHT WINDS WILL
INCREASE ACROSS THE AREA. MODEL SOUNDINGS ARE INDICATING WIND
GUSTS OF 40 TO 45 MPH ACROSS THE AREA. WITH COLDER AIR ADVECTING
INTO THE AREA THESE VALUES ARE SOMETIMES TOO LOW AND THEREFORE
SLIGHTLY HIGHER WINDS WILL BE POSSIBLE. AT THIS TIME LIMITED WIND
GUSTS THURSDAY NIGHT TO GENERALLY THE 40 TO 45 MPH RANGE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AT 12Z FRIDAY MORNING...A MODEL CONSENSUS INDICATES THAT
PRECIPITATION WILL ALREADY HAVE ENDED ACROSS THE ILN CWA. DESPITE
THE BRIEF PERIOD OF STRONG COLD ADVECTION BEHIND THE FRONT...THE
MEAN FLOW APPEARS TO BE OUT OF THE WEST-SOUTHWEST BY MID-DAY...WHICH
ACTUALLY LEADS TO WEAK WARM ADVECTION THROUGH THE AFTERNOON. THIS
WILL ALLOW TEMPERATURES TO RECOVER INTO THE 40S (NEAR 50 IN THE SE
CWA)...UNDER MOSTLY SUNNY CONDITIONS.
THE STACKED LOW PRESSURE ATTACHED TO THE THURSDAY NIGHT COLD FRONT
WILL TAKE UP RESIDENCE IN NORTHERN ONTARIO THROUGH THE
WEEKEND...LEADING TO BROAD AND WEAK TROUGHING ACROSS THE OHIO
VALLEY. THERE MAY BE ONE OR TWO WEAK UPPER DISTURBANCES MOVING
THROUGH THE REGION (MAINLY SATURDAY AND SATURDAY NIGHT) IN THE QUICK
FLOW AROUND THE FLAT TROUGH...BUT SO FAR THE MODELING OF THESE
FEATURES HAS BEEN INCONSISTENT...AT BEST. MORE CERTAIN IS THAT A
COLD FRONT WILL BE MOVING SOUTHEAST THROUGH THE REGION ON
SATURDAY...WHICH MAY ALSO BE A FOCUS FOR PRECIPITATION (BASED ON
TEMPERATURES...THIS COULD BE A MIX OF RAIN AND SNOW...BUT MAINLY
RAIN DURING THE AFTERNOON).
THE OVERALL PATTERN WILL BEGIN TO CHANGE GOING INTO THE NEW
WEEK...WITH FLOW ALOFT SHIFTING TO A SHARPER NORTHWESTERLY DIRECTION
OVER THE OHIO VALLEY. SURFACE HIGH PRESSURE WILL NUDGE IN FROM THE
NORTHERN PLAINS...KEEPING THING DRY THROUGH MONDAY.
HOWEVER...ALTHOUGH MODEL SPREAD (INCLUDING THE ENSEMBLES) IS
UNCERTAIN IN EXACT PHASE AND AMPLITUDE...A MORE SIGNIFICANT TROUGH
WILL LIKELY MOVE INTO THE REGION ON TUESDAY. THIS WILL MAKE
PRECIPITATION MORE LIKELY AT THE TAIL END OF THE EXTENDED FORECAST
PERIOD...IN ADDITION TO BRINGING A NEAR-CERTAINTY OF TEMPERATURES
FALLING WELL BELOW NORMAL.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
CONDITIONS WILL REMAIN VFR FOR THE EARLY PART OF THE FORECAST
PERIOD. LOW LEVEL MOISTURE WILL INCREASE AHEAD OF A COLD FRONT
WHICH MAY BRING A BRIEF PERIOD OF SHOWERS TO THE TERMINALS AFTER
06Z. AFTER POTENTIAL FOR SHOWERS PASSES LOW CEILINGS WILL DEVELOP.
APPEARS THAT MOST SITES WILL BECOME IFR. WITH RELATIVELY WARM AND
MOIST AIR MOVING ACROSS A MELTING SNOW PACK THERE IS THE POTENTIAL
FOR VISIBILITY RESTRICTIONS IN MIST AND DRIZZLE. HAVE ONLY DROPPED
TO MVFR VISIBILITY ALTHOUGH THERE IS THE POSSIBILITY OF LOWER
CONDITIONS. COLD FRONT WILL MOVE THROUGH AROUND 12Z WITH A GRADUAL
WIND SHIFT. CEILINGS WILL LIFT TO MVFR LATE IN THE MORNING BEFORE
SCATTERING AND LEAVING VFR CONDITIONS FOR THE END OF THE TAF
PERIOD.
OUTLOOK...MVFR TO IFR CEILINGS AND VISIBILITIES ARE POSSIBLE FROM
THURSDAY THROUGH EARLY FRIDAY. THUNDERSTORMS ARE POSSIBLE
THURSDAY NIGHT. WIND GUSTS OVER 30 KT ARE LIKELY THURSDAY NIGHT
INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...NOVAK
NEAR TERM...
SHORT TERM...NOVAK
LONG TERM...HATZOS
AVIATION...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
912 PM EST TUE FEB 18 2014
.SYNOPSIS...
A WEAK COLD FRONT PUSHES EAST LATER TONIGHT. A VIGOROUS SYSTEM
PASSES THURSDAY NIGHT...BUT MILD...PACIFIC AIR FOLLOWS IT AS WELL.
A COLD FRONT CROSSES SATURDAY NIGHT,...BEGINNING A TREND TO COLDER.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
915 PM UPDATE...NO MAJOR CHANGES NEEDED TO PREVIOUS FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
THE SYSTEM THAT PRODUCED THE PRECIPITATION LAST NIGHT HAS PUSHED
WELL TO OUR EAST...WITH WEAK HIGH PRESSURE NOW IN CONTROL OF THE
REGION. THE COMBINATION OF ABUNDANT SUNSHINE AND GUSTY SOUTHWESTERLY
WINDS HAVE PUSHED TEMPERATURES INTO THE MID 40S TO MID 50S ACROSS
MUCH OF THE AREA.
THE HIGH WILL PUSH EAST TONIGHT...ALLOWING A COLD FRONT TO
APPROACH FROM THE WEST. EXPECT CLOUDS WILL INCREASE...WITH
PRECIPITATION EXPECTED TO SPREAD NORTHEAST ACROSS THE AREA AFT 06
UTC.
THE COLD FRONT WILL PUSH EAST ON WEDNESDAY...BRINGING THE
PRECIPITATION CHANCES TO AN END.
WITH NAM/GFS AS WELL AS WPC ALL INDICATING MEASURABLE
PRECIPITATION...HAVE BUMPED POPS TO LIKELY...ALONG AND AHEAD OF THE
FRONT. LOOKS LIKE THIS WILL BE A HIGH POP...LOW QPF EVENT.
LATEST TEMP GUIDANCE SUGGESTS LOW TEMP FORECAST FOR TONIGHT AND
HIGHS ON WEDNESDAY ARE IN THE BALLPARK...SO HAVE ONLY MADE SOME
MINOR TWEAKS.
WITH WARMING TEMPS ALOFT AND MOST OF THE REGION SHOULD BE ABOVE
FREEZING AT THE SURFACE...RAIN SHOULD BE THE PREDOMINANT WEATHER
TYPE.
INITIALLY THOUGHT SOME OF THE SHELTERED NORTHERN MOUNTAIN VALLEYS
WILL BE COLD ENOUGH FOR THE PRECIPITATION TO BE IN THE FORM OF
FREEZING RAIN. BUT IT NOW LOOKS LIKE TEMPERATURES WILL FALL
EARLY...AND THEN WARM AS THE CLOUDS AND PRECIPITATION MOVE IN.
MAY BE SOME ISOLATED LOCATIONS THAT COULD SEE FREEZING RAIN...BUT IT
SHOULD NOT LAST LONG...AND BE VERY LIGHT. WITH THIS CHANGE...DO NOT
THINK THERE IS THE NEED FOR ANY FREEZING RAIN ADVISORIES.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
SPRING SPRINGS THIS PERIOD AS STRONG S FLOW AHEAD OF A VIGOROUS S/W
TROUGH / SFC COLD FRONT BRINGS A RATHER MILD THU...FOLLOWED BY THE
THREAT FOR STRONG THUNDERSTORMS THU EVENING.
BUBBLE HIGH EXITS WED EVENING...ALLOWING STRENGTHENING FLOW FROM THE
S AHEAD OF THE NEXT SYSTEM. WARM FRONT ASSOCIATED WITH THIS SYSTEM
MOVES NWD THROUGH THE AREA EARLY THU MORNING THROUGH THE DAY THU.
ELEVATED INSTABILITY IN THE POSITIVE THETA E ADVECTION COULD LEAD TO
THUNDER AHEAD OF AND ALONG THE WARM FRONT AS PW VALUES CLIMB TO
AROUND AN INCH AND SHOWALTERS GO TO ZERO.
WARM SECTOR BECOMES ESTABLISHED BY THU EVENING...BEFORE COLD FRONT
COMES CHARGING THROUGH OVERNIGHT. PW VALUES GET AS HIGH AS ABOUT
1.25 IN AS SFC DEW POINTS APPROACH 50 AND H85 WIND INCREASE TO 70
KTS OR BETTER. INSTABILITY AXIS JUST AHEAD OF THE COLD FRONT WANES
AS IT CROSSES THE AREA THU NT BUT...GIVEN THE STRONG FLOW
ALOFT...ANY CONVECTIVE LINE THAT GETS GOING UPSTREAM CAN MAINTAIN A
DAMAGING WIND THREAT AT LEAST AS FAR E AS THE E EDGE OF THE SLIGHT
RISK AREA...WHICH CUTS N-S THROUGH HTS...WITH STRONG GUSTS POSSIBLE
WELL E OF THERE. THE RUC WIND GUST MOMENTUM ALGORITHM YIELDS GUSTS
TO 40 KTS OVER THE HIGH TERRAIN AND UP TO 30 KTS OVER THE
LOWLANDS...SO IT WILL TAKE HEAVY SHOWERS...OR THUNDERSTORMS...TO
BRING THE GREATER MOMENTUM DOWN. THE HWO ALREADY CARRIES A SEVERE
THREAT IN THE SLIGHT RISK AREA PER PREVIOUS SHIFT.
USED GFS/NAM BLEND FOR QPF WHICH IS UP NEAR AN INCH IN THE
W...DIMINISHING TO AS LITTLE AS A QUARTER OF AN INCH IN THE
MOUNTAINS...WAY TO LITTLE TO RELEASE THE SNOW PACK EVEN WITH STRONG
WINDS AND DEW POINTS ABOVE FREEZING. THE CANADIAN IS AN ODD MODEL
OUT IN NOT PUSHING THE COLD FRONT THROUGH UNTIL FRI MORNING.
IT APPEARS THE COLD ADVECTION BEHIND THIS COLD FRONT WILL BE TOO
WEAK TO COUNTER DIURNAL HEATING FRI...AS TEMPERATURES WILL RECOVER
TO HIGHS ABOVE NORMAL. A BUBBLE HIGH OF PACIFIC ORIGIN PASSES S OF
THE AREA FRI AFTERNOON...AS LOW PRESSURE INTENSIFIES OVER SERN
CANADA. THE GRADIENT BETWEEN THESE TWO FEATURES WILL PRODUCE STRONG
WINDS...ESPECIALLY ACROSS THE N...WHERE THE MOMENTUM ALGORITHM PUMPS
OUT GUSTS AROUND 30 KTS.
BLENDED IN GFS-BASED BIAS CORRECTED MOS FOR HIGHS AND NAM12 AND THE
MET FOR NON-DIURNAL TEMPERATURES BOTH NTS...OVERALL LITTLE CHANGE
FROM PREVIOUS FCST SAVE FOR TIMING OF COLDER AIR THU NT...A LITTLE
LATER.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS SHOWING COLD AIR MOVING BACK INTO THE REGION LATE THIS
WEEKEND. BOTH THE ECMWF AND GFS SHOWING A POTENTIAL ENHANCED CLIPPER
SNOW EARLY NEXT WEEK. HOWEVER...LOTS OF DIFFERENCES IN THE ENSEMBLE
MEMBERS ON THE TIMING OF FEATURES...EVEN THOUGH ENSEMBLES SUPPORT
THE BROADER PATTERN WITH A TROUGH IN THE EAST. THEREFORE...USED THE
ECMWF AND GEFS MEANS...AS CONFIDENCE WITH INDIVIDUAL ENERGY PIECES
IS LOW.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
00Z WEDNESDAY THROUGH 00Z THURSDAY...
MAINLY VFR CONDITIONS DURING THE PERIOD...HOWEVER...A DISTURBANCE
WILL APPROACH THE AREA AFTER 06Z...SPREADING PRECIPITATION MAINLY
IN THE FORM OF -RA ACROSS THE AREA...AND PERHAPS POCKETS OF -FZRA
ACROSS THE NORTHERN MOUNTAINS. EXPECT BRIEF MVFR CONDITIONS
BETWEEN 06Z-18Z WEDNESDAY IN PRECIPITATION. RELATIVELY LIGHT
SOUTHEASTERLY WINDS THROUGH 06Z...BECOMING SOUTHWESTERLY TO
WESTERLY AND GUSTY AFTER 06Z...WITH GUSTS UP TO 35 KTS ACROSS
HIGHER TERRAIN...AND UP TO 22 KTS ACROSS LOWLANDS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF THE ONSET OF PRECIPITATION AND MVFR
PREVALENT CIGS MAY VARY...AND IMPROVEMENT TO VFR MAY ALSO 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 WED 02/19/14
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EST 1HRLY 21 22 23 00 01 02 03 04 05 06 07 08
CRW CONSISTENCY H H H H H H H H H L L L
HTS CONSISTENCY H H H H H H H H M L L L
BKW CONSISTENCY H H H H H H L L L L L L
EKN CONSISTENCY H H H H H H H H H L M L
PKB CONSISTENCY H H H H H H H L L L L L
CKB CONSISTENCY H H H H H H H H H L L L
AFTER 00Z THURSDAY...
IFR POSSIBLE THURSDAY NIGHT IN GUSTY SHOWERS...AND POSSIBLY A STRONG
THUNDERSTORM.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JSH/TRM/RPY
NEAR TERM...JSH/SL
SHORT TERM...TRM
LONG TERM...RPY
AVIATION...SL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
629 PM EST TUE FEB 18 2014
.SYNOPSIS...
A WEAK COLD FRONT PUSHES EAST LATER TONIGHT. A VIGOROUS SYSTEM
PASSES THURSDAY NIGHT...BUT MILD...PACIFIC AIR FOLLOWS IT AS WELL.
A COLD FRONT CROSSES SATURDAY NIGHT,...BEGINNING A TREND TO COLDER.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
630 PM UPDATE...NO MAJOR CHANGES NEEDED TO PREVIOUS FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
THE SYSTEM THAT PRODUCED THE PRECIPITATION LAST NIGHT HAS PUSHED
WELL TO OUR EAST...WITH WEAK HIGH PRESSURE NOW IN CONTROL OF THE
REGION. THE COMBINATION OF ABUNDANT SUNSHINE AND GUSTY SOUTHWESTERLY
WINDS HAVE PUSHED TEMPERATURES INTO THE MID 40S TO MID 50S ACROSS
MUCH OF THE AREA.
THE HIGH WILL PUSH EAST TONIGHT...ALLOWING A COLD FRONT TO
APPROACH FROM THE WEST. EXPECT CLOUDS WILL INCREASE...WITH
PRECIPITATION EXPECTED TO SPREAD NORTHEAST ACROSS THE AREA AFT 06
UTC.
THE COLD FRONT WILL PUSH EAST ON WEDNESDAY...BRINGING THE
PRECIPITATION CHANCES TO AN END.
WITH NAM/GFS AS WELL AS WPC ALL INDICATING MEASURABLE
PRECIPITATION...HAVE BUMPED POPS TO LIKELY...ALONG AND AHEAD OF THE
FRONT. LOOKS LIKE THIS WILL BE A HIGH POP...LOW QPF EVENT.
LATEST TEMP GUIDANCE SUGGESTS LOW TEMP FORECAST FOR TONIGHT AND
HIGHS ON WEDNESDAY ARE IN THE BALLPARK...SO HAVE ONLY MADE SOME
MINOR TWEAKS.
WITH WARMING TEMPS ALOFT AND MOST OF THE REGION SHOULD BE ABOVE
FREEZING AT THE SURFACE...RAIN SHOULD BE THE PREDOMINANT WEATHER
TYPE.
INITIALLY THOUGHT SOME OF THE SHELTERED NORTHERN MOUNTAIN VALLEYS
WILL BE COLD ENOUGH FOR THE PRECIPITATION TO BE IN THE FORM OF
FREEZING RAIN. BUT IT NOW LOOKS LIKE TEMPERATURES WILL FALL
EARLY...AND THEN WARM AS THE CLOUDS AND PRECIPITATION MOVE IN.
MAY BE SOME ISOLATED LOCATIONS THAT COULD SEE FREEZING RAIN...BUT IT
SHOULD NOT LAST LONG...AND BE VERY LIGHT. WITH THIS CHANGE...DO NOT
THINK THERE IS THE NEED FOR ANY FREEZING RAIN ADVISORIES.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
SPRING SPRINGS THIS PERIOD AS STRONG S FLOW AHEAD OF A VIGOROUS S/W
TROUGH / SFC COLD FRONT BRINGS A RATHER MILD THU...FOLLOWED BY THE
THREAT FOR STRONG THUNDERSTORMS THU EVENING.
BUBBLE HIGH EXITS WED EVENING...ALLOWING STRENGTHENING FLOW FROM THE
S AHEAD OF THE NEXT SYSTEM. WARM FRONT ASSOCIATED WITH THIS SYSTEM
MOVES NWD THROUGH THE AREA EARLY THU MORNING THROUGH THE DAY THU.
ELEVATED INSTABILITY IN THE POSITIVE THETA E ADVECTION COULD LEAD TO
THUNDER AHEAD OF AND ALONG THE WARM FRONT AS PW VALUES CLIMB TO
AROUND AN INCH AND SHOWALTERS GO TO ZERO.
WARM SECTOR BECOMES ESTABLISHED BY THU EVENING...BEFORE COLD FRONT
COMES CHARGING THROUGH OVERNIGHT. PW VALUES GET AS HIGH AS ABOUT
1.25 IN AS SFC DEW POINTS APPROACH 50 AND H85 WIND INCREASE TO 70
KTS OR BETTER. INSTABILITY AXIS JUST AHEAD OF THE COLD FRONT WANES
AS IT CROSSES THE AREA THU NT BUT...GIVEN THE STRONG FLOW
ALOFT...ANY CONVECTIVE LINE THAT GETS GOING UPSTREAM CAN MAINTAIN A
DAMAGING WIND THREAT AT LEAST AS FAR E AS THE E EDGE OF THE SLIGHT
RISK AREA...WHICH CUTS N-S THROUGH HTS...WITH STRONG GUSTS POSSIBLE
WELL E OF THERE. THE RUC WIND GUST MOMENTUM ALGORITHM YIELDS GUSTS
TO 40 KTS OVER THE HIGH TERRAIN AND UP TO 30 KTS OVER THE
LOWLANDS...SO IT WILL TAKE HEAVY SHOWERS...OR THUNDERSTORMS...TO
BRING THE GREATER MOMENTUM DOWN. THE HWO ALREADY CARRIES A SEVERE
THREAT IN THE SLIGHT RISK AREA PER PREVIOUS SHIFT.
USED GFS/NAM BLEND FOR QPF WHICH IS UP NEAR AN INCH IN THE
W...DIMINISHING TO AS LITTLE AS A QUARTER OF AN INCH IN THE
MOUNTAINS...WAY TO LITTLE TO RELEASE THE SNOW PACK EVEN WITH STRONG
WINDS AND DEW POINTS ABOVE FREEZING. THE CANADIAN IS AN ODD MODEL
OUT IN NOT PUSHING THE COLD FRONT THROUGH UNTIL FRI MORNING.
IT APPEARS THE COLD ADVECTION BEHIND THIS COLD FRONT WILL BE TOO
WEAK TO COUNTER DIURNAL HEATING FRI...AS TEMPERATURES WILL RECOVER
TO HIGHS ABOVE NORMAL. A BUBBLE HIGH OF PACIFIC ORIGIN PASSES S OF
THE AREA FRI AFTERNOON...AS LOW PRESSURE INTENSIFIES OVER SERN
CANADA. THE GRADIENT BETWEEN THESE TWO FEATURES WILL PRODUCE STRONG
WINDS...ESPECIALLY ACROSS THE N...WHERE THE MOMENTUM ALGORITHM PUMPS
OUT GUSTS AROUND 30 KTS.
BLENDED IN GFS-BASED BIAS CORRECTED MOS FOR HIGHS AND NAM12 AND THE
MET FOR NON-DIURNAL TEMPERATURES BOTH NTS...OVERALL LITTLE CHANGE
FROM PREVIOUS FCST SAVE FOR TIMING OF COLDER AIR THU NT...A LITTLE
LATER.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS SHOWING COLD AIR MOVING BACK INTO THE REGION LATE THIS
WEEKEND. BOTH THE ECMWF AND GFS SHOWING A POTENTIAL ENHANCED CLIPPER
SNOW EARLY NEXT WEEK. HOWEVER...LOTS OF DIFFERENCES IN THE ENSEMBLE
MEMBERS ON THE TIMING OF FEATURES...EVEN THOUGH ENSEMBLES SUPPORT
THE BROADER PATTERN WITH A TROUGH IN THE EAST. THEREFORE...USED THE
ECMWF AND GEFS MEANS...AS CONFIDENCE WITH INDIVIDUAL ENERGY PIECES
IS LOW.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
00Z WEDNESDAY THROUGH 00Z THURSDAY...
MAINLY VFR CONDITIONS DURING THE PERIOD...HOWEVER...A DISTURBANCE
WILL APPROACH THE AREA AFTER 06Z...SPREADING PRECIPITATION MAINLY
IN THE FORM OF -RA ACROSS THE AREA...AND PERHAPS POCKETS OF -FZRA
ACROSS THE NORTHERN MOUNTAINS. EXPECT BRIEF MVFR CONDITIONS
BETWEEN 06Z-18Z WEDNESDAY IN PRECIPITATION. RELATIVELY LIGHT
SOUTHEASTERLY WINDS THROUGH 06Z...BECOMING SOUTHWESTERLY TO
WESTERLY AND GUSTY AFTER 06Z...WITH GUSTS UP TO 35 KTS ACROSS
HIGHER TERRAIN...AND UP TO 22 KTS ACROSS LOWLANDS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z
THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF THE ONSET OF PRECIPITATION AND MVFR
PREVALENT CIGS MAY VARY...AND IMPROVEMENT TO VFR MAY ALSO 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 WED
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06
CRW CONSISTENCY H H H H H H H H H H H L
HTS CONSISTENCY H H H H H H H H H H M L
BKW CONSISTENCY H H H H H H H H L L L L
EKN CONSISTENCY H H H H H H H H H H H L
PKB CONSISTENCY H H H H H H H H H L L L
CKB CONSISTENCY H H H H H H H H H H H L
AFTER 00Z THURSDAY...
IFR POSSIBLE THURSDAY NIGHT IN GUSTY SHOWERS...AND POSSIBLY A STRONG
THUNDERSTORM.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JSH/TRM/RPY
NEAR TERM...JSH/SL
SHORT TERM...TRM
LONG TERM...RPY
AVIATION...SL
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1240 PM CST MON FEB 17 2014
.UPDATE...
CLOUDS HAVE THINNED ACROSS THE SOUTHERN HALF OF THE AREA THIS
AFTERNOON AND AS A RESULT TEMPERATURES HAVE BEEN ON THE MARCH
UPWARDS. RAISED MAX T GRIDS FOR THE SOUTHERN ZONES. NEW GRIDS OUT
SHORTLY. 23
&&
.PREV DISCUSSION... /ISSUED 1133 AM CST MON FEB 17 2014/
AVIATION...
COLD FRONT WILL BE WORKING ITS WAY INTO SE TX THIS AFTERNOON AND WILL
STALL SOMEWHERE ACROSS THE AREA. COULD SEE SOME CLEARING BEHIND THE
FRONT FOR OUR FAR NORTHERN TAFS...BUT FURTHER TO THE SOUTH EXPECT
PERIODS OF MAINLY MVFR CEILINGS THROUGHOUT THE AFTERNOON. AS THE FRONT
BEGINS TO MOVE BACK TO THE NORTH TONIGHT...LOW MAINLY MVFR CEILINGS
ARE ANTICIPATED ALONG AND SOUTH OF THE BOUNDARY WITH PERIODS OF IFR
CEILINGS AND VISIBILITIES POSSIBLE TOO. PERIODS OF IFR/LIFR CEILINGS
AND VISIBILITIES POSSIBLE AT GLS DUE TO AREA SEA FOG. 42
PREV DISCUSSION... /ISSUED 1004 AM CST MON FEB 17 2014/
UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
DISCUSSION...
MOSTLY CLOUDS SKIES ACROSS THE AREA CURRENTLY ALONG WITH SOME DENSE
FOG IN THE BAYS. A COLD FRONT HAS JUST MADE IT PAST DFW AND IS
EXPECTED TO CONTINUE TO SAG SOUTHWARDS DURING THE AFTERNOON. THIS
FRONT IS IN ASSOCIATION WITH A SHORTWAVE CURRENTLY MOVING EAST
ACROSS THE MIDWEST. THINKING REMAINS MOSTLY UNCHANGED THAT THE
FRONT WILL STALL IN BRAZOS COUNTY WITH A WIND SHIFT POSSIBLE A
BIT FURTHER SOUTH. THIS WILL MEAN THAT WARM AND HUMID CONDITIONS
WILL PERSIST FOR MUCH OF SOUTHEAST TEXAS TODAY ALONG WITH THE FOG
IN THE BAYS. BECAUSE OF THIS HAVE EXTENDED THE DENSE FOG ADVISORY
UNTIL NOON TODAY FOR THE BAYS AND NEARSHORE WATERS.
THE OTHER CONCERN WILL BE AFTERNOON TEMPERATURES. 850MB
TEMPERATURES ARE CURRENTLY AROUND 18C WHICH IS VERY WARM FOR THIS
TIME OF YEAR. CLOUDS ALONG WITH SOME 850 COOLING WILL HELP KEEP
AFTERNOON TEMPERATURES FROM REALIZING THEIR FULL POTENTIAL BUT IT
STILL SHOULD BE WARM. WOULDN`T BE SURPRISED IF SOME PLACES HIT 80
THIS AFTERNOON. MODELS ARE ALSO SHOWING THAT JUST BEHIND THE FRONT
THERE WILL BE SOME CLEARING WITH THE COLDER AIR HOLDING BACK SOME.
AS OF NOW IT LOOKS LIKE THE CLEARING LINE WILL COME UP JUST SHORT
OF KCLL. IF THE CLEARING LINE MAKES IT TO KCLL TEMPERATURES WILL
LIKELY QUICKLY RISE AS CAA HOLDS BACK. FOR NOW HAVE JUST BUMPED UP
HIGH TEMPERATURES A DEGREE AT KCLL AND A COUPLE OF OTHER PLACES.
WILL KEEP AN EYE ON THAT CLEARING LINE AS RAP SHOWS TEMPERATURES
AROUND 80 AT HEARNE THIS AFTERNOON. NO OTHER CHANGES PLANNED AT
THIS TIME. 23
PREV DISCUSSION... /ISSUED 354 AM CST MON FEB 17 2014/
DISCUSSION...
WEAK FRONT WILL MAKE ITS WAY INTO NRN PARTS OF SE TX THIS AFTN
THEN STALL SOMEWHERE ALONG A LINE FROM MAYBE COLUMBUS-LIVINGSTON
THIS EVENING. THE BOUNDARY WILL HEAD BACK NORTH EARLY TUE. WX
SHOULD OTHERWISE BE STATUS QUO THRU EARLY THURS WITH MCLDY WARM
CONDITIONS PREVAILING. AND SOME PERIODS OF SEA FOG AT THE COAST.
MADE SOME FCST CHANGES LATE THURS & INTO THE WEEKEND. FRONT THAT
WAS EARLIER EXPECTED TO STALL INLAND LATE THURS NOW LOOKS LIKE IT
SHOULD HAVE MORE THAN ENOUGH SUPPORT TO PUSH WELL OFF THE COAST
THURS EVENING. NUDGED POPS UP A TOUCH AS WELL AS PW`S CLIMB TO
1.3-1.5" IN ADVANCE OF THE BOUNDARY. FAVORABLE RRQ JET POSITION &
STRONG LLVL JET NOTED...BUT CAP APPEARS LIKE IT MIGHT WIN OUT &
LIMIT MUCH CONVECTIVE PRECIP OVER OUR FA. LOWERED TEMPS IN THE
WAKE OF THE FRONT AND PULLED MENTION OF SEA FOG W/ ITS PASSAGE AS
WELL.
SOME DIFFERENCES IN THE MEDIUM RANGE SOLNS THIS WEEKEND AND
BEYOND. ECMWF IS QUICK TO BRING A RETURN OF MOISTURE AND PRECIP
CHANCES ACROSS SRN PARTS OF THE AREA LATE SAT WHILE GFS BRINGS A
WEAK REINFORCING BOUNDARY OFF THE COAST AT THAT TIME. NO REAL
CONFIDENCE IN EITHER ONE AT THIS POINT. BOTH DO INDICATE A 1040+MB
HIGH SLIDING SWD INTO THE PLAINS NEXT WEEK AND SENDING ASSOCIATED
FRONT INTO OUR REGION AROUND 25TH OR 26TH. 47
MARINE...
GENERALLY LIGHT/MODERATE ONSHORE WINDS WILL PREVAIL THROUGH MUCH OF
THIS WEEK. A WEAK COLD FRONT IS EXPECTED TO MOVE INTO THE NRN PARTS
OF SE TX TONIGHT BUT SHOULD STALL BEFORE IT REACHES THE COAST. AS A
RESULT...WINDS OVER THE COASTAL WATERS SHOULD REMAIN OUT OF THE SSE.
A SECOND STRONGER FRONT IS FCST TO MOVE THROUGH THE AREA LATER THIS
WEEK (LIKELY THURS NIGHT/EARLY FRI MORNING). UNTIL THEN SEA FOG MAY
BE AN ISSUE FOR THE BAYS/NEARSHORE WATERS AS THE WARMER AIRMASS OV-
ERRIDES THE COOLER SHELF WATERS. ONSHORE WINDS COULD GET STRENGTHEN
ENOUGH BY WEDS NIGHT/THURS FOR CAUTION FLAGS. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 55 76 61 77 63 / 10 10 10 10 10
HOUSTON (IAH) 60 76 63 77 64 / 10 10 10 10 10
GALVESTON (GLS) 60 69 61 70 63 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1133 AM CST MON FEB 17 2014
.AVIATION...
COLD FRONT WILL BE WORKING ITS WAY INTO SE TX THIS AFTERNOON AND WILL
STALL SOMEWHERE ACROSS THE AREA. COULD SEE SOME CLEARING BEHIND THE
FRONT FOR OUR FAR NORTHERN TAFS...BUT FURTHER TO THE SOUTH EXPECT
PERIODS OF MAINLY MVFR CEILINGS THROUGHOUT THE AFTERNOON. AS THE FRONT
BEGINS TO MOVE BACK TO THE NORTH TONIGHT...LOW MAINLY MVFR CEILINGS
ARE ANTICIPATED ALONG AND SOUTH OF THE BOUNDARY WITH PERIODS OF IFR
CEILINGS AND VISIBILITIES POSSIBLE TOO. PERIODS OF IFR/LIFR CEILINGS
AND VISIBILITIES POSSIBLE AT GLS DUE TO AREA SEA FOG. 42
&&
.PREV DISCUSSION... /ISSUED 1004 AM CST MON FEB 17 2014/
UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
DISCUSSION...
MOSTLY CLOUDS SKIES ACROSS THE AREA CURRENTLY ALONG WITH SOME DENSE
FOG IN THE BAYS. A COLD FRONT HAS JUST MADE IT PAST DFW AND IS
EXPECTED TO CONTINUE TO SAG SOUTHWARDS DURING THE AFTERNOON. THIS
FRONT IS IN ASSOCIATION WITH A SHORTWAVE CURRENTLY MOVING EAST
ACROSS THE MIDWEST. THINKING REMAINS MOSTLY UNCHANGED THAT THE
FRONT WILL STALL IN BRAZOS COUNTY WITH A WIND SHIFT POSSIBLE A
BIT FURTHER SOUTH. THIS WILL MEAN THAT WARM AND HUMID CONDITIONS
WILL PERSIST FOR MUCH OF SOUTHEAST TEXAS TODAY ALONG WITH THE FOG
IN THE BAYS. BECAUSE OF THIS HAVE EXTENDED THE DENSE FOG ADVISORY
UNTIL NOON TODAY FOR THE BAYS AND NEARSHORE WATERS.
THE OTHER CONCERN WILL BE AFTERNOON TEMPERATURES. 850MB
TEMPERATURES ARE CURRENTLY AROUND 18C WHICH IS VERY WARM FOR THIS
TIME OF YEAR. CLOUDS ALONG WITH SOME 850 COOLING WILL HELP KEEP
AFTERNOON TEMPERATURES FROM REALIZING THEIR FULL POTENTIAL BUT IT
STILL SHOULD BE WARM. WOULDN`T BE SURPRISED IF SOME PLACES HIT 80
THIS AFTERNOON. MODELS ARE ALSO SHOWING THAT JUST BEHIND THE FRONT
THERE WILL BE SOME CLEARING WITH THE COLDER AIR HOLDING BACK SOME.
AS OF NOW IT LOOKS LIKE THE CLEARING LINE WILL COME UP JUST SHORT
OF KCLL. IF THE CLEARING LINE MAKES IT TO KCLL TEMPERATURES WILL
LIKELY QUICKLY RISE AS CAA HOLDS BACK. FOR NOW HAVE JUST BUMPED UP
HIGH TEMPERATURES A DEGREE AT KCLL AND A COUPLE OF OTHER PLACES.
WILL KEEP AN EYE ON THAT CLEARING LINE AS RAP SHOWS TEMPERATURES
AROUND 80 AT HEARNE THIS AFTERNOON. NO OTHER CHANGES PLANNED AT
THIS TIME. 23
PREV DISCUSSION... /ISSUED 354 AM CST MON FEB 17 2014/
DISCUSSION...
WEAK FRONT WILL MAKE ITS WAY INTO NRN PARTS OF SE TX THIS AFTN
THEN STALL SOMEWHERE ALONG A LINE FROM MAYBE COLUMBUS-LIVINGSTON
THIS EVENING. THE BOUNDARY WILL HEAD BACK NORTH EARLY TUE. WX
SHOULD OTHERWISE BE STATUS QUO THRU EARLY THURS WITH MCLDY WARM
CONDITIONS PREVAILING. AND SOME PERIODS OF SEA FOG AT THE COAST.
MADE SOME FCST CHANGES LATE THURS & INTO THE WEEKEND. FRONT THAT
WAS EARLIER EXPECTED TO STALL INLAND LATE THURS NOW LOOKS LIKE IT
SHOULD HAVE MORE THAN ENOUGH SUPPORT TO PUSH WELL OFF THE COAST
THURS EVENING. NUDGED POPS UP A TOUCH AS WELL AS PW`S CLIMB TO
1.3-1.5" IN ADVANCE OF THE BOUNDARY. FAVORABLE RRQ JET POSITION &
STRONG LLVL JET NOTED...BUT CAP APPEARS LIKE IT MIGHT WIN OUT &
LIMIT MUCH CONVECTIVE PRECIP OVER OUR FA. LOWERED TEMPS IN THE
WAKE OF THE FRONT AND PULLED MENTION OF SEA FOG W/ ITS PASSAGE AS
WELL.
SOME DIFFERENCES IN THE MEDIUM RANGE SOLNS THIS WEEKEND AND
BEYOND. ECMWF IS QUICK TO BRING A RETURN OF MOISTURE AND PRECIP
CHANCES ACROSS SRN PARTS OF THE AREA LATE SAT WHILE GFS BRINGS A
WEAK REINFORCING BOUNDARY OFF THE COAST AT THAT TIME. NO REAL
CONFIDENCE IN EITHER ONE AT THIS POINT. BOTH DO INDICATE A 1040+MB
HIGH SLIDING SWD INTO THE PLAINS NEXT WEEK AND SENDING ASSOCIATED
FRONT INTO OUR REGION AROUND 25TH OR 26TH. 47
MARINE...
GENERALLY LIGHT/MODERATE ONSHORE WINDS WILL PREVAIL THROUGH MUCH OF
THIS WEEK. A WEAK COLD FRONT IS EXPECTED TO MOVE INTO THE NRN PARTS
OF SE TX TONIGHT BUT SHOULD STALL BEFORE IT REACHES THE COAST. AS A
RESULT...WINDS OVER THE COASTAL WATERS SHOULD REMAIN OUT OF THE SSE.
A SECOND STRONGER FRONT IS FCST TO MOVE THROUGH THE AREA LATER THIS
WEEK (LIKELY THURS NIGHT/EARLY FRI MORNING). UNTIL THEN SEA FOG MAY
BE AN ISSUE FOR THE BAYS/NEARSHORE WATERS AS THE WARMER AIRMASS OV-
ERRIDES THE COOLER SHELF WATERS. ONSHORE WINDS COULD GET STRENGTHEN
ENOUGH BY WEDS NIGHT/THURS FOR CAUTION FLAGS. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 55 76 61 77 / 10 10 10 10 10
HOUSTON (IAH) 78 60 76 63 77 / 10 10 10 10 10
GALVESTON (GLS) 70 60 69 61 70 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...42
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
528 PM CST TUE FEB 18 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 321 PM CST TUE FEB 18 2014
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED SHORTWAVE TROUGHS OVER MANITOBA AND OVER EASTERN
SOUTH DAKOTA INTO NEBRASKA...RIDGING OVER THE NORTHERN
ROCKIES...AND A POTENT UPPER TROUGH JUST OFF THE BRITISH COLUMBIA
AND PACIFIC NORTHWEST COASTS. THIS POTENT UPPER TROUGH IS THE
CULPRIT FOR OUR THURSDAY STORM. DPVA AND PACIFIC MOISTURE AHEAD OF
THE TWO SHORTWAVE TROUGHS HAVE BEEN SPREADING MID AND HIGH CLOUDS
ACROSS THE FORECAST AREA TODAY. THESE CLOUDS HAVE LIMITED SOME
INSULATION...BUT SOUTHWESTERLY 925-850MB FLOW AHEAD OF A COLD
FRONT MOVING INTO THE FORECAST AREA HELPED BOOST TEMPERATURES INTO
THE 30S TO MID 40S THIS AFTERNOON. OVER WESTERN IOWA WHERE NO SNOW
EXISTS...READINGS ARE IN THE 50S TO LOW 60S. IN THE WAKE OF THE
COLD FRONT...READINGS ARE STILL IN THE 30S AND 40S...PARTIALLY DUE
TO A BIT MORE SUN AND DOWNSLOPING FLOW OFF THE NORTHERN ROCKIES.
THE QUIET BEFORE THE STORM PHRASE WORKS PERFECTLY FOR THE SHORT
TERM. 18.12Z MODEL GUIDANCE DEPICT THE RIDGING OVER THE NORTHERN
ROCKIES MARCHING EASTWARD TO ABOUT OVER THE FORECAST AREA BY 00Z
THU...PUSHED BY THE POTENT NORTHEAST PACIFIC NORTHWEST TROUGH
PLOWING INTO THE ROCKIES. ON THE EAST SIDE OF THE UPPER RIDGE AXIS
THERE IS A WEAK SHORTWAVE AT 500MB SUGGESTED TO DROP SOUTHEAST
THROUGH THE FORECAST AREA LATE TONIGHT...BUT THIS FEATURE WILL COME
THROUGH DRY WITH BASICALLY NO CLOUD.
ONLY REAL ISSUE TO CONTEND WITH TONIGHT IS IF ANY FOG CAN FORM
RESULTING FROM MELTING SNOW. ALL MODELS KEEP A DECENT PRESSURE
GRADIENT IN PLACE TONIGHT WITH A SURFACE RIDGE AXIS ONLY REACHING
WESTERN MN BY 12Z WED. 925MB WINDS STAY UP 20-30 KT FOR MUCH OF THE
NIGHT IN THE WAKE OF THE COLD FRONTAL PASSAGE THIS EVENING.
THUS...THINK ANY FOG WOULD BE LIMITED TO PERHAPS THE TYPICAL COLD
SPOTS AND SOME SMALL VALLEYS.
PLENTY OF SUN LOOKS ON TAP FOR WEDNESDAY...OUTSIDE OF SOME CLOUDS
INCREASING LATE AS THE RIDGE AXIS APPROACHES. 925MB TEMPS IN THE 0-
2C RANGE AT 18Z WED SUPPORTS HIGHS IN THE 30S TO A COUPLE
40S...WARMEST IN SOUTHWEST WI.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 321 PM CST TUE FEB 18 2014
...WINTER STORM FOR WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...
MANY FACETS OF THE STORM TO TALK ABOUT...
MODEL ANALYSIS...18.12Z GUIDANCE CONTINUES TO FOLLOW THE PAST COUPLE
OF CYCLES...PHASING TROUGHING OVER THE ROCKIES ON TOP OF THE
FORECAST AREA THURSDAY. THE PHASED UPPER TROUGH ALSO BECOMES
NEGATIVELY TITLED AS IT LIFTS THROUGH THE FORECAST AREA THURSDAY
EVENING. OVERALL...THE SPREAD IN GUIDANCE FROM 500MB TO THE SURFACE
IS FAIRLY LOW CONSIDERING THIS IS A PHASING TROUGH AND STILL ISNT
ONSHORE YET. THEREFORE...CONFIDENCE IS INCREASING THAT A HIGH IMPACT
WINTER STORM WILL AFFECT THE FORECAST AREA.
WINDS...MOST OF THE GUIDANCE IS IN AGREEMENT THAT AS THE PHASING
TAKES PLACE OF THE UPPER TROUGH...THE SURFACE LOW IS GOING TO
UNDERGO BOMBOGENESIS...DROPPING FROM A PRESSURE OF 995MB IN EASTERN
KS AT 12Z THU TO AROUND 970MB OVER LAKE SUPERIOR AT 12Z FRI. TO
HANDLE THIS PRESSURE DROP AND THE COLD AIR THAT GETS PULLED
IN...925MB WINDS INCREASE OUT OF THE WEST-NORTHWEST AT 30-50 KT ON
THE BACK SIDE OF THE STORM FOR THURSDAY EVENING. THE STRONGEST CORE
TRACKS ACROSS SOUTHEAST MN AND NORTHEAST IOWA...THE FAVORABLE
BLIZZARD AREA.
PRECIPITATION...THERE IS SOME UNCERTAINTY ON HOW QUICK PRECIPITATION
DEVELOPS. GFS/NAM/ECMWF SOUNDINGS DEPICT A DECENT DRY LAYER BETWEEN
900-700MB WEDNESDAY NIGHT...WITH MUCH OF THE LIFT FROM WARM
ADVECTION IN THAT LAYER VERSUS IN THE MID/HIGH CLOUDS ABOVE IT.
PRECIPITATION SHOULD STAND A MUCH BETTER CHANCE MOVING IN
THURSDAY...LIKELY SOUTH TO NORTH...AS THE STORM SYSTEM MOVES INTO
SOUTHERN WI. DURING THE AFTERNOON...FRONTOGENESIS IN THE MID/UPPER
LEVELS REALLY INTENSIFIES WITH THE APPROACH OF THE UPPER TROUGH...
WHICH SHOULD DEVELOP A STRONG AND HEAVY PRECIPITATING COLD CONVEYOR
BELT. PRECIPITABLE WATER PROGGED BETWEEN 0.5-0.75 INCHES OR 200-250
PERCENT OF NORMAL SUGGESTS PLENTY OF MOISTURE AVAILABLE FOR THE
FORCING TO PRODUCE FAIRLY HEAVY QPF. CROSS-SECTIONS EVEN SHOW A
LARGE AREA OF NEGATIVE EPV AND SOME WEAK CAPE IN THE AFTERNOON...
SUGGESTING THUNDER COULD OCCUR. WILL SEE IF THIS TRENDS HOLDS WITH
LATER MODELS. COLD CONVEYOR BELT WILL GRADUALLY LIFT INTO THE U.P.
OF MI THU NIGHT...GRADUALLY ENDING PRECIPITATION SOUTHWEST TO
NORTHEAST.
PRECIPITATION TYPE...A DRY WARM LAYER ALOFT SHOULD RESIDE OVER THE
FORECAST AREA WEDNESDAY NIGHT. AS THE PRECIPITATION SPREADS IN LATE
WEDNESDAY NIGHT/THURSDAY MORNING...THAT COULD FALL AS EITHER
SLEET...FREEZING RAIN OR RAIN UNTIL EVAPORATIVE COOLING SWITCHES IT
OVER TO SNOW. THE AFTERNOON IS TRICKY AND COMPLETELY DEPENDS ON THE
850MB LOW TRACK. AHEAD OF THE 850MB LOW...A WARM LAYER ALOFT AND AT
THE SURFACE WILL ADVECT NORTH...RESULTING IN A MIX OR COMPLETELY
SWITCHOVER TO RAIN. RIGHT NOW THIS SEEMS MOST PROBABLE TO OCCUR IN
FAR SOUTHEAST SECTIONS OF THE FORECAST AREA FROM 15-21Z THU. IF THE
LOW TRACKS FARTHER NORTHWEST LIKE THE 18.12Z UKMET...THEN RAIN COULD
FALL EVEN AT LA CROSSE. HOWEVER...THE UKMET IS A NORTHWEST OUTLIER.
SNOW AMOUNTS/ICE ACCUMULATION...ANY ICE ACCUMULATION LOOKS TO BE
LATE WEDNESDAY NIGHT FROM THE INITIAL WARM LAYER. EVEN SNOW AMOUNTS
REALLY DO NOT START TO PICK UP UNTIL LATE THURSDAY MORNING WHEN
HEAVIER PRECIPITATION BEGINS TO DEVELOP. DURING THURSDAY AFTERNOON
AND EVENING...1 TO 2 INCH PER HOUR RATES ARE POSSIBLE...ESPECIALLY
IF CONVECTION FORMS. PRESENTLY DEPICT 2 TO 10 INCHES FOR
TOTALS...HIGHEST IN NORTH CENTRAL WI WHERE THE LONGEST DURATION OF
SNOW IS EXPECTED. IMPORTANT...THESE AMOUNTS ARE SUBJECT TO
CHANGE...AS EVEN THE NEW 18.18Z NAM SUGGESTS OF A FOOT IN SOUTHEAST
MN.
...REST OF THE LONG TERM PERIOD...
AFTER THE WINTER STORM...THE WEATHER GETS QUIET. 18.12Z
ECMWF/CANADIAN/GFS AND ENSEMBLE DATA REMAIN CONSISTENT IN FORMING AN
OMEGA BLOCK FROM THE U.S. WEST COAST INTO ALASKA...RESULTING IN DEEP
TROUGHING OVER MUCH OF CANADA AND INTO THE UPPER MIDWEST. THIS
ALLOWS FOR A GRADUAL COOLING TREND FROM FRIDAY THROUGH NEXT
TUESDAY...AND ACCORDING TO THE CFS WOULD CONTINUE THROUGH THE REST
OF THE MONTH. WIND CHILLS THROUGH TUESDAY LOOK TO STAY JUST ABOVE
WIND CHILL ADVISORY CRITERIA...I.E. -20 F. DESPITE THE COOLING
TREND...THERE ARE NOT THAT MANY PRECIPITATING SYSTEMS TO DEAL WITH.
THERE ARE SOME HINTS OF A WEAK SHORTWAVE CROSSING THE SOUTHERN
PORTION OF THE FORECAST AREA FRIDAY NIGHT WITH SOME LIGHT SNOW.
LOOKING OUT TO MONDAY AND MONDAY NIGHT OUR SOUTHERN FORECAST AREA
COULD ALSO GET CLIPPED BY A MID LEVEL FRONTOGENESIS BAND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 528 PM CST TUE FEB 18 2014
SHORT WAVE TROUGH MOVING INTO WESTERN MINNESOTA IS GENERATING A
PATCH OF VFR CLOUDS THAT SHOULD MOVE ACROSS BOTH TAF SITES EARLY
THIS EVENING. CEILINGS EXPECTED TO BE IN THE 5 TO 6K RANGE AND
THEN SCATTERING OUT QUICKLY BEHIND THE PATCH OF CLOUDS WITH EITHER
CLEAR SKIES OR JUST A FEW MID LEVEL CLOUDS AROUND. HIGH PRESSURE
OVER THE NEBRASKA PANHANDLE WILL SINK INTO MISSOURI OVERNIGHT AND
THEN OFF INTO THE OHIO RIVER VALLEY WEDNESDAY. THIS WILL ALLOW THE
WINDS TO BE NORTHWEST OVERNIGHT GOING AROUND TO THE WEST/SOUTHWEST
ON THE BACK SIDE OF THE HIGH. ENOUGH OF A GRADIENT OVERNIGHT TO
PRODUCE WINDS AROUND 10 KNOTS WHICH SHOULD BE ENOUGH MIXING TO
PREVENT ANY FOG FROM FORMING. HOWEVER...PLENTY OF LOW LEVEL
MOISTURE FROM THE SNOW MELT TODAY AND ANY DROP IN THE WIND SPEEDS
COULD ALLOW SOME FOG TO FORM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER STORM WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY
NIGHT FOR WIZ017-029-032>034-041>044-053>055-061.
MN...BLIZZARD WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY NIGHT
FOR MNZ086-087-094-095.
WINTER STORM WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY
NIGHT FOR MNZ079-088-096.
IA...BLIZZARD WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY NIGHT
FOR IAZ008>010-018-019-029.
WINTER STORM WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY
NIGHT FOR IAZ011-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
311 PM CST MON FEB 17 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 310 PM CST MON FEB 17 2014
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED NEARLY ZONAL FLOW ACROSS MUCH OF THE NORTHERN
U.S....WITH THE BIG EXCEPTION FOR A NARROW BUT POTENT/DEEP
SHORTWAVE TROUGH EXTENDING FROM MINNESOTA INTO EASTERN MISSOURI.
STRONG LIFT AHEAD OF THE TROUGH COMBINED WITH A SURGE OF
PRECIPITABLE WATER AROUND A 0.5 INCH PER 12Z MPX SOUNDING BROUGHT
SNOW TO MUCH OF THE FORECAST AREA. THIS SNOW WAS VERY EFFICENT IN
REDUCING VISIBILITIES...WITH MANY LOCATIONS SEEING 3-4 HOURS OF
1/2 MILE OR LESS...AIDED TOO BY WINDS THAT GUSTED 20 TO 30 MPH.
ROADS QUICKLY DETEORIATED TOO. SNOWFALL ACCUMULATIONS...ON THE
OTHER HAND...WERE LESS THAN EXPECTED DESPITE THE STRONG FORCING.
BELIEVE SOME LEFT-OVER DRY AIR SEEN ON THE 12Z DVN SOUNDING
ABSORBED SOME OF THE SNOW...AND KEPT THE SNOW FROM ORGANIZING INTO
ONE SOLID AREA. IT ALSO APPEARS THAT THE STRONGEST LIFT ENDED UP
SHIFTING SOUTH...INITALLY PROGGED OVER NORTHERN WISCONSIN ON
FRIDAY TO OVER THE FORECAST AREA YESTERDAY AND IN REALITY ENDED UP
OVER ILLINOIS. STRONG SUBSIDENCE IN THE WAKE OF THE SHORTWAVE
TROUGH HAS LED TO CLEARING SKIES IN MN AND IA. WARMER AIR IS ALSO
ACCOMPANYING THE CLEARING...WITH READINGS IN THE 30S ALONG AND
WEST OF I-35.
ANY LINGERING SNOW ALONG/EAST OF THE MISSISSIPPI RIVER WILL PUSH
OFF TO THE EAST EARLY THIS EVENING. CLEARING SHOULD THEN WORK ITS
WAY ACROSS THE FORECAST AREA TONIGHT AS 500MB HEIGHTS RISE IN THE
WAKE OF THE SHORTWAVE TROUGH. ATTENTION THEN TURNS TO A STRING OF
SHORTWAVES STRETCHING FROM WASHINGTON STATE INTO SOUTHERN
SASKATCHEWAN. THESE SHORTWAVES ARE PROGGED BY ALL MODELS TO DIG
INTO THE REGION TUESDAY AFTERNOON. AHEAD OF THESE SHORTWAVES...A
PLUME OF WARMER 925-850MB AIR IS FORECAST...WITH 925MB TEMPS
CLIMBING TO 2-6C BY 12Z TUESDAY. THESE TEMPS GRADUALLY COOL
THROUGH THE DAY AS THE SHORTWAVES APPROACH...BUT THE COMBINATION
OF FILTERED SUNSHINE AND THESE WARMER TEMPS SHOULD ALLOW HIGHS TO
CLIMB INTO THE MID 30S TO LOW 40S. BOTH THE 17.12Z GFS AND ECMWF
HINT AT SOME LIGHT QPF PRODUCED FROM THESE SHORTWAVES AS WELL IN
THE AFTERNOON. SOUNDINGS DEPICT A DRY LAYER BETWEEN 700-900MB TO
OVERCOME...SO FOR NOW HAVE KEPT ANY PRECIPITATION OUT OF THE
FORECAST. WOULD NOT BE SURPRISED IF SOME SPRINKLES OCCUR...THOUGH.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 310 PM CST MON FEB 17 2014
THERE ARE TWO ITEMS OF CONCERN IN THE LONG TERM...A POSSIBLE HIGH
IMPACT WINTER STORM FOR THURSDAY...AND THEN MORE BELOW NORMAL
TEMPERATURES FOR FRIDAY AND BEYOND.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...MENTIONED IN YESTERDAYS
DISCUSSION MODELS HAD TRENDED AWAY FROM HAVING A CENTRAL PLAINS
STORM AFFECTING THE AREA. THAT HAS COMPLETELY CHANGED WITH THE
17.12Z MODELS. THE EVOLUTION OF THIS STORM IS A RESULT OF PHASING OF
TWO SHORTWAVE TROUGHS...AT 12Z THURSDAY PROGGED OVER KANSAS AND THE
DAKOTAS. THE PHASING LOOKS TO BEGIN OVER THE FORECAST AREA THURSDAY
AFTERNOON...RESULTING IN A RAPIDLY DEEPENING SURFACE LOW BEING
PULLED NORTH FROM EASTERN KANSAS INTO UPPER MI. PLENTIFUL MOISTURE
FROM THE GULF OF MEXICO SHOULD ADVECT NORTH INTO THE FORECAST AREA
AHEAD OF THE STORM...WITH PRECIPITABLE WATER VALUES PROGGED TO REACH
0.5-0.75 INCHES. WITH 17.12Z MODEL CONSENSUS ALL HEADING TOWARD THE
PHASED IDEA...INCREASING PRECIPITATION CHANCES...ESPECIALLY FOR
THURSDAY. BEING PHASED...THERE ARE GOING TO BE ISSUES...
1. PRECIPITATION TYPE. THERE IS SOME WARM AIR AROUND WEDNESDAY
NIGHT...WITH WARM LAYER ALOFT TEMPS AROUND 3C...WHICH WHEN THE
INITIAL PRECIPITATION STARTS TO FALL COULD END UP BEING AS
RAIN...FREEZING RAIN OR SLEET. EVAPORATIVE COOLING SHOULD THEN ALLOW
THE TYPE TO GO OVER TO SNOW. THIS IS TEMPORARY FOR THE SOUTHEAST
HALF OF THE FORECAST AREA...BECAUSE AS WE HEAD INTO THE DAY
THURSDAY...WARM AIR COMES BACK IN FROM THE SOUTH. AT THE SAME TIME
DAYTIME HEATING IS HELPING TO BRING TEMPERATURES UP INTO THE MID 30S
ALONG THE MS RIVER AND EAST. SO A MIX WITH RAIN IS POSSIBLE. THESE
PRECIPITATION TYPE ISSUES ARE GOING TO CREATE HAVOC WITH FORECASTING
SNOWFALL AMOUNTS.
2. SNOWFALL AMOUNTS. THE NORTHWEST / DEFORMATION SIDE OF THIS STORM
COULD EASILY PUT DOWN SOME HEAVY SNOW IF THE PHASING OCCURS AS
PLANNED. THE NEW 17.18Z NAM REALLY HITS AN AREA FROM NORTH CENTRAL
IOWA INTO CENTRAL WISCONSIN HARD WITH UPWARDS OF 1-1.5 INCHES OF
QPF. THIS IS ON THE HIGH SIDE OF ALL AVAILABLE GUIDANCE...INCLUDING
THE 15.09Z/15.15Z SREF...BUT REFLECTS THAT WE NEED TO WATCH THE
STORM. WHERE THE DEFORMATION TRACKS TOO DEPENDS ON THE STORM TRACK.
3. WINDS ON THE BACK SIDE FOR THURSDAY AFTERNOON/NIGHT. 925MB WINDS
FROM THE 17.12Z GFS AND ECMWF ARE SUGGESTED TO INCREASE TO 30-40 KT
IN A STRONG COLD ADVECTION REGIME THURSDAY EVENING. THESE WINDS
COULD RESULT IN EXTENSIVE BLOWING OF THE SNOW. INCREASED WINDS AND
MENTIONED BLOWING SNOW...BUT MAY NEED TO RAISE WINDS MORE.
WITH THE CURRENT STORM SYSTEM STILL LINGERING AROUND...AND THAT THE
MODELS HAVE JUST TRENDED BACK TO A PHASED SYSTEM...HAVE DECIDED NOT
TO ISSUE A WINTER STORM WATCH AT THIS POINT. HOWEVER...SHOULD MODELS
SHOW THE SAME THING AGAIN TONIGHT...WATCHES MAY BE NEEDED...
ESPECIALLY OVER THE NORTHWEST HALF OF THE FORECAST AREA.
FRIDAY INTO EARLY NEXT WEEK...17.12Z GFS/ECMWF/CANADIAN REMAIN IN
GOOD AGREEMENT ON A COOL DOWN EACH DAY. THIS COOL DOWN IS A RESULT
OF AN OMEGA BLOCK THAT DEVELOPS FROM ALASKA DOWN THE WEST COAST OF
THE U.S...CAUSING DEEP TROUGHING OVER MUCH OF CANADA INTO THE UPPER
MIDWEST. FOLLOWING A MODEL CONSENSUS FORECAST...WE COULD BE
APPROACHING WIND CHILL ADVISORY CONCERNS AGAIN AS EARLY AS MONDAY.
EVEN COLDER AIR APPEARS TO BE LURKING BEYOND MONDAY...ESPECIALLY IN
THE ECMWF AND CFS. THIS DEEP UPPER TROUGHING FORMING PUSHES MOST
PRECIPITATING SYSTEMS SOUTH OF THE FORECAST AREA...BUT DO HAVE SOME
LOW CHANCES OF SNOW HERE AND THERE FOR SHORTWAVES TRAVERSING THE
BOTTOM OF THE TROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY NOON)
ISSUED AT 1135 AM CST MON FEB 17 2014
BAND OF MDT/HEAVY SNOW WITH IFR/LIFR VSBYS AND IFR/MVFR CIGS
CONTINUED TO MOVE EAST ACROSS THE FCST AREA AT MID-DAY. BACK EDGE OF
THIS BAND WAS ALREADY MOVING INTO THE KRST AREA...WITH DECREASING
CLOUDS/CLEARING ALREADY APPROACHING I-35. TRENDED KRST FOR IMPROVING
CONDITIONS THRU THE 18-21Z PERIOD. FURTHER EAST...DISTANCE-SPEED
TOOL HAS THE HEAVIER SNOW MOVING EAST OF KLSE BY 1930Z THEN ENDING
BY MID AFTERNOON...WITH THE DECREASE OF CLOUDS MOVING IN AROUND 22Z.
WILL NEED TO WATCH THE DECREASE OF CLOUDS AT BOTH KRST/KLSE...AS
APPEARS SOME MVFR CLOUDS MAY PIVOT SOUTHEAST FROM WEST OF KMSP AND
HOLD MVFR CIGS ACROSS SOUTHEAST MN/WESTERN WI LATER INTO THE
AFTERNOON AS FLOW BECOMES NORTHWEST BEHIND THE SNOW BAND INTO EARLY
THIS EVENING.
SFC-700MB FLOW TURNS BACK TO THE WEST AND SOUTHWEST BY LATER THIS
EVENING AS THE NEXT TROUGH MOVES INTO THE NORTHERN PLAINS...WHICH
WOULD ADVECT ANY MVFR CLOUDS THAT MAY LINGER OUT OF THE AREA DURING
THE EVENING. GOOD VFR EXPECTED FOR THE LATE EVENING THRU MORNING
HOURS OF TUE. STRONG WARMING AND THE SOUTHWEST FLOW TUE MAY PUSH
SOME BOUNDARY LAYER MOISTURE FROM MELTING SNOW ACROSS IA NORTHWARD
FOR TUE...FOR WHAT MAY BE SOME SCT MVFR CLOUDS BY LATE MORNING AND
FOR TUE AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR WIZ017-029-
034-042>044-053>055-061.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CST SUN FEB 16 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 316 PM CST SUN FEB 16 2014
MAIN SHORT TERM FORECAST IS ON HEAVY SNOW EXPECTED MONDAY MORNING.
CURRENTLY AS OF 20Z...WATER VAPOR IMAGERY AND RAP 500MB HEIGHT
ANALYSIS SHOWED A SHORTWAVE TROUGH EXTENDING FROM ALBERTA THROUGH
IDAHO...RIDGING FROM TEXAS INTO SOUTHERN MANITOBA...AND TROUGHING
OVER THE NORTHEAST U.S.. WITH THE FORECAST AREA IN THE INFLECTION
POINT EAST OF THE UPPER RIDGE AXIS...HIGH PRESSURE EXISTS AT THE
SURFACE WITH SUBSIDENCE AND DRYING IN THE LOW TO MID LEVELS. THIS
RESULTED IN CLEARING OF LOW CLOUDS THIS MORNING. HOWEVER...MID AND
HIGH CLOUDS ARE QUICKLY SPREADING EAST FROM THE DAKOTAS INTO THE
FORECAST AREA. THESE ARE ASSOCIATED WITH A WARM ADVECTION REGIME IN
PLACE ON THE BACK SIDE OF THE SURFACE HIGH. PRECIPITABLE WATER
ANALYSIS SHOWED VALUES AROUND 0.5 INCH FROM OKLAHOMA INTO WESTERN
NORTH DAKOTA...COMPARED TO 0.1-0.25 INCHES OVER THE FORECAST AREA.
MODELS REMAIN CONSISTENT WITH THE EXPECTED SNOW TO MOVE ACROSS THE
AREA LATER TONIGHT INTO MONDAY. THE MAIN FEATURE RESPONSIBLE FOR THE
SNOW IS THE SHORTWAVE TROUGH OVER IDAHO WHICH REACHES THE
FORECAST AREA AT 18Z MONDAY. ITS WORTH NOTING THAT BETWEEN 12-18Z
MONDAY THE SHORTWAVE TROUGH INTENSIFIES AND TAKES ON A NEGATIVE
TILT. IN RESPONSE LIFT GREATLY INCREASES AHEAD OF THE TROUGH...AND
TO BALANCE SUBSIDENCE INCREASES BEHIND IT. THE LIFT WILL ACT ON
THE PLUME OF 0.5 INCH PRECIPITABLE WATER SEEN OVER THE WESTERN
DAKOTAS TO PRODUCE THE SNOW.
SOME INTERESTING FACETS FOR TONIGHT INTO MONDAY...
1. AS THE LOW LEVEL JET INCREASES TONIGHT AHEAD OF THE TROUGH...IT
APPEARS A WARM ADVECTION BAND OF SNOW WILL DEVELOP FROM CENTRAL INTO
SOUTHEAST MN AROUND MIDNIGHT...THEN LIFT NORTHEASTWARD THROUGH THE
REST OF THE NIGHT. UNSURE HOW MUCH OF THIS SNOW WILL REACH THE
SURFACE AS MODELS DEPICT LEFTOVER DRY AIR BETWEEN 750-900MB THAT
NEEDS SATURATING. THEREFORE...PRECIPITATION CHANCES ARE KEPT LOWER
PRIOR TO 09Z. AS WE APPROACH 12Z...THE BIG BATCH OF SNOW ASSOCIATED
WITH THE WARM CONVEYOR BELT AND DPVA AHEAD OF THE SHORTWAVE TROUGH
WILL ENCOMPASS MUCH OF THE WESTERN HALF OF THE FORECAST AREA.
2. THERE IS A VERY TIGHT MODEL CONSENSUS FOR 12-18Z MONDAY TO BE THE
TIME PERIOD OF HEAVIEST QPF/SNOW. WITH A LITTLE NEGATIVE EPV THROWN
IN IN THE MID LEVELS...EASILY COULD SEE SOME CONVECTIVE NATURE TO
THE SNOW. SNOWFALL RATES OF 1 INCH PER HOUR EASILY SEEM PLAUSIBLE
FOR A COUPLE HOURS...KNOCKING VISIBILITIES DOWN TO 1/4 MILE. THESE
RATES SHOULD OCCUR AT THE WORST TIME...MORNING COMMUTE. ALTHOUGH
TOTAL SNOWFALL AMOUNTS OVER THE SOUTHWEST HALF OF THE FORECAST AREA
ARE ONLY FORECAST RIGHT NOW IN THE 4-5 INCH RANGE...BELOW WARNING
CRITERIA...ISSUED A WARNING BASED ON TIME OF DAY. FAR WESTERN AREAS
SUCH AS ROCHESTER LOOK TO GET INTO SOME BLOWING SNOW TOO. ALSO
WARNED FOR THAT AREA BECAUSE THE 16.12Z MODELS HAVE TRENDED QPF UP
ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA...NOW NEAR 1/3 OF
AN INCH.
3. WITH THE STRONG SUBSIDENCE OCCURRING ON THE BACK SIDE OF THE
TROUGH...SKIES SHOULD CLEAR WEST TO EAST DURING THE MID AFTERNOON
INTO THE EVENING HOURS. THIS SHOULD MAKE THE AFTERNOON COMMUTE MUCH
MORE MANAGEABLE...PROVIDED ROADS ARE CLEANED UP IN TIME.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 316 PM CST SUN FEB 16 2014
AFTER AN ACTIVE SHORT TERM PERIOD...THE LONG TERM LOOKS FAIRLY
QUIET. THERE ARE SOME ITEMS OF INTEREST...
1. TEMPERATURES CLIMBING ABOVE NORMAL TUESDAY AND WEDNESDAY. THE
FLOW PATTERN BECOMES MORE ZONAL...ALLOWING PACIFIC AIR TO FLOW INTO
THE FORECAST AREA. WARMEST DAY SHOULD COME TUESDAY AHEAD OF A COLD
FRONT PASSING THROUGH LATE IN THE DAY. 850MB TEMPS ARE PROGGED TO
CLIMB TO 4-6C...WHICH SHOULD ALLOW HIGHS TO TOP OUT AS HIGH AS THE
LOW 40S. SLIGHTLY COOLER CONDITIONS ARE FORECAST ON WEDNESDAY BEHIND
THE FRONT. IT SHOULD BE NOTED THAT THE LAST TIME LA CROSSE WAS ABOVE
NORMAL WAS JANUARY 30TH. AT ROCHESTER...IT WAS JANUARY 16TH.
2. STORM SYSTEM LIFTING OUT OF THE CENTRAL PLAINS WEDNESDAY NIGHT.
ECMWF RUNS FROM 15.00Z AND PRIOR TOOK THIS SYSTEM AND REALLY
INTENSIFIED IT WHILE LIFTING NORTHEAST THROUGH THE FORECAST AREA.
THAT CHANGED WITH THE 15.12Z ECMWF AND LATEST 16.12Z
ECMWF/CANADIAN/GFS CONTINUE TO BRING THE SYSTEM INTO LOWER MICHIGAN
BY THURSDAY EVENING. ALONG ITS TRACK...ASSISTED BY A NORTHERN STREAM
SHORTWAVE TROUGH CROSSING THE UPPER MIDWEST...A BAND OF
PRECIPITATION IS LOOKING MORE LIKELY TO MOVE THROUGH THE AREA LATE
WEDNESDAY NIGHT INTO THURSDAY MORNING. ENOUGH WARM AIR LOOKS TO GET
PULLED UP INTO THE SYSTEM TO ALLOW FOR A MIX OF PRECIPITATION IN
SOUTHEAST SECTIONS OF THE FORECAST AREA. SOMETHING WORTH MONITORING.
3. SYSTEM TO BRING A BRIEF BOUT OF SNOW FRIDAY INTO FRIDAY NIGHT.
BOTH THE 16.12Z GFS AND CANADIAN BRING A SHORTWAVE TROUGH AND
DEFORMATION SNOW ACROSS THE FORECAST AREA DURING THIS TIME FRAME.
HOWEVER...THERE IS NO SIGN OF THIS SHORTWAVE IN THE ECMWF. FOR NOW
JUST HAVE LOW CHANCES OF SNOW IN THE FORECAST.
4. HEADING BACK TO BELOW NORMAL BEGINNING THURSDAY NIGHT. ALL MODELS
HAVE MATCHED UP WELL WITH CFS FORECASTS SUGGESTING TEMPERATURES
GOING BACK BELOW NORMAL AS TROUGHING REESTABLISHES ITSELF OVER THE
UPPER MIDWEST. BY THE WEEKEND...850MB TEMPS MAY GET STUCK BELOW -10C
AGAIN...WITH SOME HINTS OF -20C AIR COMING AT THE AREA JUST BEYOND
THE LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1100 PM CST SUN FEB 16 2014
WINTER STORM WILL BRING SNOW...LOW VSBYS/CLOUDS...AND GUSTY WINDS TO
THE REGION MONDAY MORNING. INCH PER HOUR SNOWFALL RATES ARE EXPECTED
FOR A FEW HOURS...AND BLSN SHOULD OCCUR AT KRST FOR A GOOD PORTION
OF THE DAY.
TIMING ON WHEN THE HEAVIEST SNOW MOVES IN...AND MOVES OUT...PRESENTS
SOME CHALLENGES. BUFKIT SOUNDINGS SUGGEST A FEW HOURS EARLIER THAN
MODELED QPF FIELDS. TRENDS IN THE MODELS HAVE BEEN A BIT SLOWER
THOUGH...WITH LATEST RAP/HRRR/NAM12 ALSO SUGGESTING A DELAY IN HEAVY
SNOW ONSET. ENOUGH AGREEMENT IN THE MODELS TO FOLLOW SUIT...AND WILL
ADJUST TAFS. MEANWHILE...MID LEVEL FRONTOGENETIC WING COULD PRODUCE
A BAND OF SNOW WELL AHEAD OF THE MAIN AREA SNOW. MOST OF THIS WOULD
PROBABLY BE 4-P6SM FOR VSBY. STILL FOCUSING ON A 4 HOUR TIME FRAME
FOR THE HEAVY SNOW.
SOUTHEAST WINDS HAVE INCREASED AS THE PRESSURE GRADIENT TIGHTENS
AHEAD OF THE SHORTWAVE TROUGH/SFC LOW. SOME SLACKENING CAN BE
EXPECTED AS THE SNOW COMES IN - WITH A BAGGIER GRADIENT. STILL...IT
WILL BE STRONG ENOUGH TO BLOW/DRIFT THE SNOW AT KRST...AND MUCH OF
THE VSBY REDUCTIONS OUTSIDE OF THE HEAVY SNOW CAN BE ATTRIBUTED TO
THAT. THE SYSTEM/S COLD FRONT SHOULD MOVE THROUGH IN THE 21-00Z MON
TIME FRAME...WITH A SCATTERING OUT OF THE CLOUD DECK.
ANTICIPATE REFINEMENTS TO THE FORECAST AS RADAR TRENDS MAKE SNOW
ONSET/EXIT MORE EVIDENT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER STORM WARNING FROM 3 AM TO 3 PM CST MONDAY FOR WIZ017-029-
032>034-041>044-053>055-061.
MN...WINTER STORM WARNING FROM 3 AM TO 3 PM CST MONDAY FOR MNZ079-
086>088-094>096.
IA...WINTER STORM WARNING FROM 3 AM TO 3 PM CST MONDAY FOR IAZ008>011-
018-019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS ALBANY NY
437 AM EST WED FEB 19 2014
.SYNOPSIS...
ANOTHER FAST MOVING LOW PRESSURE SYSTEM WILL BRING A
PERIOD OF SNOW AND RAIN TO THE REGION THIS AFTERNOON AND EVENING.
MILDER AIR WILL THEN MOVE INTO THE REGION BY THE END OF THE
WEEK...ALONG WITH A CHANCE OF RAIN SHOWERS AS A STRONG COLD FRONT
APPROACHES FROM THE GREAT LAKES THURSDAY NIGHT AND FRIDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 435 AM EST...HIGH AND MID LEVEL CLOUDS ARE INCREASING ACROSS
THE REGION. TEMPS...WHICH INITIALLY DROPPED INTO THE SINGLE DIGITS
AND LOWER TEENS DUE TO SIGNIFICANT BOUNDARY LAYER DECOUPLING
ALONG WITH THE VERY DEEP SNOWCOVER...HAVE NOW STARTED TO RISE. WE
EXPECT MOST TEMPS TO RISE INTO THE TEENS TO LOWER 20S BY
SUNRISE...ALTHOUGH MAY STILL REMAIN IN THE LOWER TEENS ACROSS
PORTIONS OF THE UPPER HUDSON VALLEY.
WE HAVE A VERY CHALLENGING FORECAST AHEAD FOR TODAY...AS A POTENT
SHORTWAVE CURRENTLY CROSSING APPROACHING THE MIDWEST TRANSLATES
RAPIDLY EASTWARD. THIS FEATURE...IN COMBINATION WITH A WEAKER LEAD
UPPER LEVEL IMPULSE...HAS TRIGGERED CONSIDERABLE ELEVATED
CONVECTION ACROSS THE NORTHERN APPALACHIANS AND UPPER OHIO VALLEY
EARLY THIS MORNING. THE LATEST RAP13 AND HRRR INDICATE THAT THE
REMNANTS OF THIS CONVECTION SHOULD TRACK EAST NORTHEAST...ACROSS
MAINLY CENTRAL AND SOUTHERN PORTIONS OF THE REGION THIS AFTERNOON.
THUS...PRECIP WILL BE MOST FAVORED FOR THE EASTERN
CATSKILLS...NORTHEAST INTO THE CAPITAL REGION...BERKSHIRES...MID
HUDSON VALLEY AND NW CT...AND SOUTHERN VT...WITH POTENTIALLY LESS
TO THE N AND W. HOWEVER...SHOULD THIS CONVECTION WEAKEN...IT IS
POSSIBLE THAT BETTER MOISTURE TRANSPORT COULD ALLOW FOR PRECIP TO
DEVELOP FURTHER NORTHWARD.
FURTHER COMPLICATING THE FORECAST WILL BE THE EXPECTED THERMAL
PROFILES AS THE PRECIP OCCURS. FORECAST SOUNDINGS...ESP SOUTH OF
ALBANY...INDICATE AN ABOVE FREEZING LAYER DEVELOPING AROUND 925
MB. THIS...IN COMBINATION WITH SOME BOUNDARY LAYER WARMING...WOULD
PROMOTE RAIN. HOWEVER...WITH A BURST OF STRONG VERTICAL VELOCITY
AND WET BULB COOLING...THE LOW LEVELS SHOULD COOL SUFFICIENTLY TO
ALLOW FOR SNOW AFTER A PERIOD OF RAIN/SNOW MIX IN SOME VALLEY
AREAS. SO...ASSUMING WE GET INTO THE BETTER DYNAMICAL FORCING THIS
AFTERNOON...WE HAVE SIDED MORE WITH SNOW THAN RAIN FOR MOST AREAS.
THIS SHOULD GIVE MOST VALLEY AREAS AROUND AN INCH OF SNOW...WITH
1-3 INCHES POSSIBLE ACROSS HIGHER ELEVATIONS SURROUNDING THE
HUDSON VALLEY...ESPECIALLY ACROSS THE BERKSHIRES AND SOUTHERN VT.
AGAIN...THIS IS A VERY TRICKY SITUATION...AND SHOULD ANY HEAVIER
PRECIP LINGER OVER ANY ONE AREA LONGER THAN EXPECTED...HIGHER
SNOWFALL AMTS COULD OCCUR.
HAVE SIDED WITH...OR EVEN COOLER THAN THE COLDER MOS FOR TODAY/S
MAX TEMPS...WITH MID/UPPER 30S IN VALLEY AREAS FROM ALBANY
SOUTH...AND GENERALLY LOWER/MID 30S TO THE NORTH...WITH GENERALLY
20S TO LOWER 30S ACROSS HIGHER ELEVATIONS.
SOUTH TO SOUTHEAST WINDS WILL INCREASE THIS MORNING THROUGH EARLY
AFTERNOON...SIMILAR TO YESTERDAY...WITH SOME GUSTS POSSIBLY
REACHING UP TO 30-35 MPH ACROSS PORTIONS OF SW VT...THE
BERKSHIRES...AND TACONICS...AND POSSIBLY UP TO 25-30 MPH WITHIN
THE CAPITAL REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...AS THE MAIN SHORTWAVE TROUGH PASSES THROUGH...ANOTHER
BURST OF PRECIPITATION IS EXPECTED. THE PRECIP SHOULD BE MORE
SHOWERY IN NATURE. IN FACT...MODEL SOUNDINGS ACTUALLY INDICATE RATHER
STEEP LAPSE RATES IN THE 700-500 HPA LAYER...WITH THE LATEST RAP13
INDICATING AS STEEP AS 8-8.5 C/KM. THESE STEEP LAPSE RATES...COMBINED
WITH ASCENT FROM THE APPROACHING/PASSING SHORTWAVE TROUGH...COULD
EVEN ALLOW FOR SOME ISOLATED THUNDERSTORMS ACROSS THE
REGION...SOME OF WHICH COULD PRODUCE GRAUPEL/SMALL HAIL. IN THE
WAKE OF THE TROUGH PASSAGE...STRONG WEST/NORTHWEST WINDS WILL
LIKELY DEVELOP...WITH ENHANCED FLOW DOWN THE MOHAWK RIVER
VALLEY/CAPITAL REGION AND BERKSHIRES EXPECTED. THIS COULD ALLOW
FOR SOME GUSTS TO REACH 35-40 MPH AT TIMES LATER THIS EVENING
UNTIL SHORTLY AFTER MIDNIGHT. SKIES SHOULD INITIALLY REMAIN MOSTLY
CLOUDY...BUT AS STRONG SUBSIDENCE AND SOME DOWNSLOPING
OCCURS...SKIES SHOULD TREND TO MOSTLY CLEAR WELL AFTER MIDNIGHT.
TEMPS WILL BE TRICKY...AS THERE COULD BE A WINDOW OF RAPID
DECOUPLING RIGHT AROUND OR EVEN AFTER DAYBREAK. HOWEVER...WIND AND
SOME CLOUDS SHOULD KEEP THIS FROM OCCURRING FOR MOST OF THE NIGHT.
SO...ALTHOUGH HAVE SIDED WITH THE COOLER MOS...DID NOT GO MUCH
COOLER. STILL EXPECT WIDESPREAD TEENS AND 20S ACROSS THE REGION.
THURSDAY...HIGH PRESSURE RIDGE WILL TRANSLATE EAST ACROSS THE
REGION. SKIES SHOULD BE MOSTLY SUNNY IN THE MORNING...WITH CLOUDS
INCREASING IN THE AFTERNOON. SOME LIGHT PRECIPITATION COULD REACH
FAR WESTERN AREAS TOWARD OR JUST AFTER SUNSET...MAINLY AS
RAIN...ALTHOUGH A RAIN/SLEET/SNOW MIX COULD OCCUR IN HIGHER
ELEVATIONS. EXPECT MAX TEMPS TO REACH THE UPPER 30S TO LOWER 40S
IN MOST VALLEY AREAS...AND LOWER/MID 30S FOR HIGHER ELEVATIONS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS POTENT STORM WRAPS UP ACROSS THE CENTRAL GREAT LAKES
REGION...EQUALLY IMPRESSIVE LOW LEVEL JET AND ISENTROPIC LIFT WILL
UNFOLD ACROSS UPSTATE NEW YORK THURSDAY NIGHT. THIS WILL ALLOW FOR
BANDS OF PRECIPITATION TO EVOLVE FROM SOUTH TO NORTH WITH THE PEAK
OF THE LOW LEVEL FORCING TAKING PLACE ACROSS THE ADIRONDACKS.
THERMAL PROFILES ACROSS THE REGION WILL BE TRANSITIONING WITHIN THE
WARM ADVECTION AS BOUNDARY LAYER TEMPS MAY STRUGGLE FOR A PERIOD OF
TIME. THIS SETS THE STAGE FOR SNOW MIXING WITH SLEET/FREEZING RAIN
IMPACTING MAINLY THE ADIRONDACKS AND SOUTHERN
GREENS...ALTHOUGH...COULD NOT RULE OUT SOME ISOLATED SHELTERED
LOCATIONS RECEIVING A WINTRY MIX IN THE MOHAWK AND CENTRAL-NORTHERN
HUDSON RIVER VALLEY. HOWEVER...THE STRENGTH OF THE WARM ADVECTION
WILL EVENTUALLY OVERCOME THE SHALLOW SUB FREEZING TEMPERATURES
FRIDAY MORNING FOR ALL OF THE PRECIPITATION TO BECOME RAIN.
ALONG WITH THE TEMPERATURES INCREASING...SO DOES THE DEWPOINT TO
ABOVE FREEZING. AS THIS WARMER AND MORE MOIST AIR ADVECTS OVER A
SNOW COVERED GROUND WOULD RESULT IN FOG AS WE WILL PLACE THIS IN THE
GRIDS. STRONG COLD FRONT WITH A FAIRLY TIGHT THERMAL GRADIENT FROM
+8C AT H850 OVER EASTERN NY TO -6C OVER WESTERN NY WILL QUICKLY MOVE
ACROSS THE REGION BY EARLY AFTERNOON PER THE LATEST NCEP MODEL SUITE
TIMING. AN INTERESTING NOTE HERE IS THE SHOWALTER VALUES FROM LATE
MORNING TO EARLY AFTERNOON DROP TO AROUND 0C WHICH SUGGESTS THE
WINDOW OF OPPORTUNITY FOR THUNDER. HOWEVER...WE WILL HOLD OFF ON
THE MENTION IN THE FORECAST/GRIDS UNTIL UPSTREAM TRENDS CAN BE
BETTER OBTAINED.
OVERALL...TEMPERATURES DURING THIS TIME FRAME WILL BE MAINLY
NON-DIURNAL DUE TO THE WARM ADVECTION THURSDAY NIGHT AND CONTINUING
TO RISE THROUGH FRIDAY.
THE LONG TERM WILL FEATURE A RETURN BACK TO WINTER TEMPERATURES AND
A VERY ACTIVE/FAST CYCLONIC FLOW ACROSS THE NORTHEAST CORRIDOR.
THE STORM THAT DEVELOPS OVER THE GREAT LAKES REGION SLOWLY FILLS AND
TRANSITIONS INTO A HUDSON/JAMES BAY LOW. WE WILL BE ON THE SOUTHERN
PERIPHERY OF THIS LOW WHICH KEEPS US RATHER UNSETTLED AND NEAR TO
BELOW NORMAL TEMPERATURES. THE TIMING OF SHORT WAVES WILL BE A
CHALLENGE IN THESE FAST FLOW REGIMES. PER THE GLOBAL MODELS...THE
FIRST WAVE ARRIVES SATURDAY WITH MAINLY THE EASTERN GREAT LAKES AND
SOME LAKE EFFECT SNOW IMPACTING PORTIONS OF THE ADIRONDACKS. THE
NEXT WAVE ARRIVES SUNDAY WITH A BIT MORE OF A SOUTHERN ROUTE. THIS
WAVE ATTEMPTS TO BE AN OVERACHIEVER PER THE ECMWF WITH THE GFS/GGEM
MUCH FLATTER AND MORE PROGRESSIVE. GIVEN THE RECENT TRACK RECORD OF
THE ECMWF...WE WILL PLACE SLIGHT CHANCE POPS FOR NOW.
LOOKING AHEAD INTO THE NEW WORK WEEK...THE HUDSON/JAMES BAY UPPER
LOW LOSES ITS GRIP AS WE MONITOR A POTENT PIECE OF ENERGY DIVE
SOUTHWARD FROM THE NORTHWEST TERRITORIES INTO THE INTERMOUNTAIN
WEST AND QUICKLY OUT ONTO THE CENTRAL PLAINS AND MID WEST BY
TUESDAY. THIS WILL REINTRODUCE THE CHANCE FOR ADDITIONAL WINTRY
PRECIPITATION LATE MONDAY INTO TUESDAY FOR THE ENTIRE CWFA.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
RATHER CHALLENGING IN THE NEAR TERM AS CLEAR SKIES WITH LIGHT WINDS
AND SNOW FROM EARLIER HAS RESULTED IN MVFR/IFR CONDITIONS AT KGFL
WITH OTHER TAF SITES HINTING AT THE POSSIBILITY. WE WILL PLACE A
TEMPO GROUP AT THIS TIME...AS WE MONITOR TRENDS AND UPSTREAM HIGH
AND MID LEVEL CLOUD COVER ADVECTING INTO THE REGION. THIS SHOULD
MINIMIZE THE FOG FROM SPREADING BUT IT WILL BE CLOSE.
AFTER SUNRISE...VISIBILITIES SHOULD IMPROVE AS WE WATCH THE NEXT
CLIPPER SYSTEM APPROACHING. THIS IS EXPECTED TO BRING ANOTHER
CHANCE FOR PRECIPITATION LATE THIS MORNING INTO THE AFTERNOON
HOURS. BOUNDARY LAYER TEMPERATURES WILL BE CLOSE TO RESULT IN
EITHER SN/RASN/RA. FOR NOW...WE FEEL KGFL WILL BE MAINLY SNOW WITH
A MIXTURE FURTHER SOUTH INTO KALB-KPSF AND TRANSITIONING TO ALL RAIN
KPOU. PRECIP SHOULD END THIS EVENING FROM WEST TO EAST RATHER
QUICKLY.
VARIABLE WINDS AT LESS THAN 6 KT WILL SWITCH TO A W-NW DIRECTION
...BUT SWITCH TO A SOUTHERLY DIRECTION AND INCREASE TO AROUND 10 KTS
FOR WEDNESDAY MORNING...AND CONTINUE INTO THE AFTERNOON.
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.
&&
.HYDROLOGY...
SNOW DEPTHS ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN NEW
ENGLAND ARE GENERALLY FROM A FOOT TO THREE FEET. ALTHOUGH WE HAVE
WARMER TEMPERATURES IN THE FORECAST FOR THE LATTER PART OF THE
WEEK...EXCEPT FOR THURSDAY NIGHT...OVERNIGHT LOWS WILL BE AROUND OR
SLIGHTLY BELOW FREEZING WHICH SHOULD RESULT IN A SLOW MELT AND
HOPEFULLY MINIMIZE ANY FLOOD THREAT. RAINFALL TOTALS THURSDAY NIGHT
INTO FRIDAY MORNING ARE FORECAST TO GENERALLY BE IN THE QUARTER TO
HALF INCH RANGE...SO MUCH OF THIS RAINFALL SHOULD BE ABSORBED BY THE
CURRENT SNOWPACK.
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 25.7 INCHES THROUGH THE 16TH. THIS AMOUNT IS ONLY 0.3
INCHES FROM REACHING INTO THE TOP 10 FOR SNOWIEST FEBRUARYS SINCE
1885.
A LIGHT TO MODERATE SNOWFALL IS EXPECTED TUESDAY.
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. 27.5 INCHES 1899
8. 26.1 INCHES 1914
9. 26.0 INCHES 1958
10. 26.0 INCHES 1988
LOOKING AT THE SEASONAL SNOWFALL IT STANDS AT 62.8 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...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...KL/GJM
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...BGM
AVIATION...BGM/NAS
HYDROLOGY...KL/GJM
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
357 AM EST WED FEB 19 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS OUR REGION THIS AFTERNOON. A WARM FRONT
IS FORECAST TO ARRIVE LATER THURSDAY NIGHT, THEN A STRONG COLD FRONT
SWEEPS ACROSS OUR AREA FRIDAY. ANOTHER COLD FRONT SHOULD CROSS THE
MID ATLANTIC REGION SATURDAY NIGHT AND EARLY SUNDAY. A STRONG HIGH
PRESSURE SYSTEM BUILDING DOWN INTO THE NORTHERN PLAINS LATER SUNDAY
INTO MONDAY, WILL THEN EXPAND EASTWARD TO THE MID ATLANTIC REGION
INTO TUESDAY. AN AREA OF LOW PRESSURE HOWEVER MAY TRACK NEARBY
TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK HIGH PRESSURE WAS MOVG AWAY FROM THE REGION. AS IT DOES, A
WEAK CDFNT WILL APPROACH FROM THE W. THIS FRONT WILL PASS THROUGH
THE REGION DURG THE LATE MRNG OR ERLY AFTN BUT WILL NOT BRING MUCH
IN THE WAY OF COLDER TEMPS. WHAT THE FRONT WILL BRING IS SOME
PRECIP AND HERE LIES THE CHALLENGE.
THE LATEST WIDE VIEW OF THE RADAR SHOWED THE NEAREST PRECIP BACK
NEAR THE OH/WV/KY BORDER AND SOME IN WRN NC. THE HRRR SEEMS TO BE
HANDLING THIS WELL. THE PRECIP ADVANCES NEWD, BUT HAS SOME DISTANCE
TO TRAVEL BEFORE IT GETS HERE. ITS ARRIVAL TIME IS PROBABLY A BIT
LATER NOW THAN ORIGINALLY THOUGHT. TEMPS ARE STARTING OUT VERY COLD
THIS MRNG BUT WILL RISE WELL INTO THE 40S FROM THE I-95 CORRIDOR S
AND E, AND INTO THE 50S OVER SRN AND ERN PORTIONS OF THE AREA.
HIGHS ARE EXPECTED TO BE AROUND 40 OR IN THE LOW 40S N AND W. SO
ITS A QUESTION OF WHAT HAPPENS FIRST...DO THE TEMPS RISE ABOVE
FREEZING (AND HOW LOW DO THEY GET BEFOREHAND) ESPECIALLY N AND W OR
DOES THE PRECIP GET HERE FIRST?
IF THE PRECIP ARRIVES FIRST IN THE NRN AND WRN AREAS THEN THE
FREEZING RAIN THREAT IS STILL PRESENT. HOWEVER, THE LATER THE
PRECIP ARRIVES, THE LESSER THE THREAT. THE FURTHER S AND E, THE
LESSER THE THREAT. SO, FOR NOW, WILL LET THE FREEZING RAIN ADVISORY
RIDE, BUT MAY BE ABLE TO CANCEL PORTIONS OF IT WITH THE NEXT UPDATE
DEPENDING ON WHERE THE PRECIP IS AND TEMPS ARE AT THAT TIME. IF THE
GUID IS CORRECT WITH 14-15Z ARRIVAL TIME OF THE PRECIP, THEN MANY
AREAS MAY BE OUT OF THE WOODS AND JUST SEE PLAIN RAIN. WE`LL WAIT
AND SEE.
REGARDLESS, ALL AREAS WILL SEE PLAIN RAIN THRU THE AFTN HOURS WITH A
TAPERING BY EVE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
HIGH PRES WILL BUILD IN BEHIND THE FRONT TONIGHT AND EXPECT A CLEAR
SKY WITH LESSENING WIND. THE FACT THAT THERE WILL BE SOME WIND
WOULD PRECLUDE GOOD RADIATIONAL COOLING CONDS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE OVERALL SYNOPTIC SETUP IS COMPRISED OF AN AMPLIFIED FLOW WITH A
STRONG TROUGH FROM THE MIDWEST TO THE SOUTHERN PLAINS THURSDAY. A
PORTION OF THIS TROUGH SLIDES ACROSS THE NORTHEAST FRIDAY, HOWEVER
THE MAIN TROUGH REMAINS FROM THE PLAINS ON EASTWARD THROUGH THE
WEEKEND. THIS IS COURTESY OF A CLOSED LOW BECOMING ANCHORED NEAR THE
HUDSON BAY REGION. THIS WILL ALLOW THE FLOW TO PUSH A FEW SYSTEMS
OUR WAY, WITH THE MOST NOTABLE ONE SCHEDULED FOR FRIDAY. OVERALL, A
MILDER TIME FRAME IS EXPECTED THROUGH AT LEAST SATURDAY THEN SOME
COOLING TAKES PLACE. A MORE SUBSTANTIAL CHANGE TO COLDER WEATHER
ONCE AGAIN LOOKS TO TAKE PLACE NEXT WEEK. WE GENERALLY USED A MODEL
BLEND THURSDAY INTO SATURDAY, THEN LEANED MORE TOWARD THE 00Z WPC
GUIDANCE AND CONTINUITY.
FOR THURSDAY...HIGH PRESSURE TO OUR EAST WILL DRIVE AN INCREASING
SOUTHERLY FLOW ACROSS THE AREA. AS AN UPPER-LEVEL TROUGH AMPLIFIES
TO OUR WEST, LOW PRESSURE WILL DEEPEN AND TRACK UP ACROSS THE GREAT
LAKES. THIS INCREASING FLOW DOWNSTREAM WILL ALLOW FOR INCREASING WAA
FOR OUR AREA. AS A RESULT, CLOUDS WILL BE ON THE INCREASE DURING THE
DAY. THE INCREASING FLOW WILL ALSO ALLOW HIGHER DEW POINTS TO ADVECT
NORTHWARD, ESPECIALLY AS A WARM FRONT GRADUALLY LIFTS NORTHWARD.
DESPITE THE STRONGER FLOW ALOFT, MANY INLAND AREAS ESPECIALLY SHOULD
BE ABLE TO REMAIN DECOUPLED PARTICULARLY WHERE A DECENT SNOWCOVER
REMAINS. THIS SHOULD LEAD TO SOME FOG DEVELOPING AT NIGHT, AND SOME
COULD BE LOCALLY DENSE. THE INITIAL SURGE IN WAA MAY ALLOW FOR SOME
RAIN IN THE AFTERNOON NEAR OUR FAR WESTERN ZONES, THEN WAA AND A
STRENGTHENING INVERSION COMBINED WITH MOISTENING LOW LEVELS MAY
RESULT IN A BIT OF LIGHT RAIN AND DRIZZLE AT NIGHT. THIS IS MAINLY
AIMED AT OUR NORTHERN ZONES WHERE THE BETTER ISENTROPIC LIFT SLIDES
NORTHWARD. IT WILL BE COLDER ALONG THE ATLANTIC COAST GIVEN THE FLOW
OFF OF THE ATLANTIC WHERE THE OCEAN WATER TEMPERATURES ARE IN THE
30S.
FOR FRIDAY...AN INTENSE SURFACE LOW IS FORECAST TO TRACK TOWARDS THE
HUDSON BAY REGION. THIS STORM IS EXPECTED TO OCCLUDE WITH OUR AREA
IN THE WARM SECTOR UNTIL A STRONG COLD FRONT SWEEPS THROUGH IN THE
AFTERNOON. AHEAD OF THE COLD FRONT, THE 850 MB AND 925 MB FLOW IS
FORECAST TO BE ABOUT 50-70 KNOTS. DESPITE THE ROBUST FLOW, THE
FORECAST SOUNDINGS OVERALL INDICATE THE AIRMASS BECOMING DEEPLY
SATURATED WHICH WOULD HOLD DOWN THE INSTABILITY. THE SOUTHERLY FLOW
MAY TEND TO KEEP SOME COOLER AIR IN PLAY ESPECIALLY CLOSER TO THE
COAST GIVEN THE OCEAN WATER TEMPERATURES IN THE 30S. THE COLD FRONT
ITSELF IS STRONG AND THERE APPEARS TO BE A RIBBON OF LINEAR FRONTAL
FORCING, WHICH MAY RESULT IN A FAST MOVING LOW-TOPPED CONVECTIVE
LINE WITH LITTLE OR NO LIGHTNING. THE VERTICAL EXTENT AND LIGHTNING
WITH ANY CONVECTION WILL BE GOVERNED BY THE AMOUNT OF INSTABILITY
REALIZED. THERE IS THE POTENTIAL FOR LOCALLY STRONG/DAMAGING WINDS
WITH ANY ORGANIZED CONVECTIVE ELEMENTS, ESPECIALLY IF ANY LINEAR
SEGMENTS SURGE FORWARD/BOW GIVEN THE ROBUST AND DEEP SOUTHWESTERLY
FLOW.
OTHERWISE, A BAND OF HEAVY SHOWERS WILL ROLL ACROSS THE REGION WITH
THE POTENTIAL FOR BRIEF BUT LOCAL DOWNPOURS. ONCE THE FRONT SHIFTS
EAST, SHOWERS ARE EXPECTED TO QUICKLY END FROM WEST TO EAST IN THE
AFTERNOON. THERE IS SOME CONCERN ABOUT THE DEGREE OF SURFACE WARMING
ESPECIALLY FROM ABOUT THE LEHIGH VALLEY ON NORTHWARD DUE TO A DEEPER
SNOWPACK THAT SHOULD STILL BE IN PLACE AND MIXING UNCERTAINTIES
/850 MB TEMPERATURES ARE FORECAST TO SURGE TO ABOUT +10 TO +12C
AHEAD OF THE FRONT/. EVEN WITHOUT THUNDER, THERE IS THE POTENTIAL
FOR GUSTY GRADIENT WINDS ESPECIALLY ACROSS THE DELMARVA AND INTO
SOUTHERN NEW JERSEY WHERE BETTER MIXING MAY BECOME ESTABLISHED FOR A
TIME.
FOR SATURDAY AND SUNDAY...A POTENT SURFACE LOW NEAR THE HUDSON BAY
AREA IS FORECAST TO GRADUALLY SPIN DOWN AS IT SHIFTS EASTWARD DURING
THIS TIME FRAME. SOME ADDITIONAL ENERGY THOUGH WITHIN THE TROUGH
ALONG THE SOUTHERN PERIPHERY MAY SEND ANOTHER COLD FRONT THROUGH OUR
AREA LATER SATURDAY NIGHT AND SUNDAY MORNING. THIS BOUNDARY MAY HAVE
A WEAK SURFACE LOW ALONG IT AS THE WESTERLY FLOW HELPS TO ORGANIZE A
WEAK PRESSURE TROUGH EAST OF THE MOUNTAINS. OVERALL, THIS FEATURE
GENERALLY LOOKS TO BE ON THE WEAKER SIDE WITH LIMITED MOISTURE TO
WORK WITH. AS A RESULT, WE FOLLOWED WPC`S LEAD AND WENT WITH A DRY
FORECAST ATTM. WE DID HOWEVER INCREASE THE CLOUDS A BIT MORE
ESPECIALLY LATER SATURDAY NIGHT AND SUNDAY.
FOR MONDAY AND TUESDAY...THE UPPER-LEVEL FLOW MAY BEGIN TO AMPLIFY
ONCE AGAIN IN A WAY THAT DRIVES COLDER AIR INTO THE EASTERN STATES.
THIS COULD BE INTRODUCED BY A LEAD SHORT WAVE THAT SPAWNS A SURFACE
LOW NEAR THE MID ATLANTIC, OR PERHAPS A CLIPPER TYPE SYSTEM THAT MAY
THEN REDEVELOP OFF THE MID ATLANTIC COAST. THIS APPEARS TO BE
POSSIBLE DURING TUESDAY WITH THE CHC OF SOME SNOW AS THE AIRMASS
GETS COLDER. THEREFORE, WENT DRY FOR MONDAY THEN LOW CHC POPS
TUESDAY WITH HIGHS A LITTLE COLDER. OUR CONFIDENCE REGARDING THE
TIMING AND DETAILS THIS FAR OUT IS LOW, HOWEVER THERE ARE SOME SIGNS
OF A RETURN TO COLDER AIR ALONG WITH CHCS OF SOME SNOW.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THERE IS SOME FOG CAUSING LCL MVFR CONDS THIS MRNG OTHERWISE MOST
SITES ARE VFR. THEY WILL REMAIN VFR UNTIL PRECIP MOVES IN LATER
THIS MRNG. THEN MVFR/IFR CONDS WILL PREVAIL THRU LATE AFTN. A
FRONT WILL THEN CROSS THE REGION AND END THE PRECIP BY LATE AFTN AND
BRING A RETURN TO VFR CONDS. VFR CONDS WILL THEN BE THE RULE FOR
THE REMAINDER OF THE TAF PD. THERE COULD BE SOME FZRA AT THE ONSET
FOR KABE AND KRDG DEPENDING ON THE TIME THE PRECIP ARRIVES, BEFORE A
CHANGEOVER TO RA. EVERYWHERE ELSE WILL SEE PLAIN RAIN. WIND WILL
BE SE TO S TODAY GENLY AROUND 10 KT THEN BECOME WLY 10 TO 15 KT
EARLY TONIGHT BEHIND THE FROPA BEFORE DECREASING LATE.
OUTLOOK...
THURSDAY...VFR DURING THE DAY WITH AN INCREASE IN CLOUDS. THE
CONDITIONS THEN DETERIORATE AT NIGHT TO MVFR/IFR DUE TO STRATUS
AND/OR FOG. THERE IS THE POTENTIAL FOR SOME DRIZZLE OR LIGHT RAIN
AT NIGHT. A WARM FRONT LIFTING NORTH ACROSS OUR AREA AT NIGHT MAY
RESULT IN A PERIOD OF LOW-LEVEL WIND SHEAR, AS SOUTHWESTERLY FLOW
AT 2,000 FEET INCREASES TO NEAR 50 KNOTS ESPECIALLY LATE.
FRIDAY...MVFR/IFR DUE TO STRATUS AND/OR FOG IN THE MORNING WITH
PERHAPS SOME LIGHT RAIN OR DRIZZLE. LOW-LEVEL WIND SHEAR IS POSSIBLE
IN THE MORNING WITH SOUTHWESTERLY FLOW AT 2,000 FEET AROUND 50
KNOTS. A STRONG COLD FRONT SWEEPS ACROSS THE AREA DURING THE
AFTERNOON. A BAND OF SHOWERS AND PERHAPS SOME THUNDERSTORMS SHOULD
ACCOMPANY THE FRONT. SOUTHWEST WINDS 10-20 KNOTS AHEAD OF THE FRONT
MAY BE RATHER GUSTY ESPECIALLY WITH ANY HEAVIER SHOWERS OR A
THUNDERSTORM, THEN SHIFT TO THE NORTHWEST FOLLOWING THE COLD FRONT.
A RETURN TO VFR IS EXPECTED FOLLOWING THE COLD FRONTAL PASSAGE.
SATURDAY AND SUNDAY...OVERALL VFR.
&&
.MARINE...
WILL LET THE CURRENT SCA FLAG CONTINUE AS PREV ISSUED AS WIND AND
SEAS ARE EXPECTED TO INCREASE AS A CDFNT APPROACHES THE WATERS AND
THEN CROSSES THEM LATER TODAY. HIGH PRESSURE WILL THEN BUILD IN
BEHIND THE FRONT AND THE WIND AND SEAS SHOULD GRADUALLY SUBSIDE.
OUTLOOK...
THURSDAY...SUB-ADVISORY CONDITIONS DURING THE DAY, THEN WINDS AND
SEAS INCREASE AT NIGHT AS A WARM FRONT LIFTS NORTH AND A COLD FRONT
APPROACHES FROM THE WEST. THE AIRMASS WILL BE WARMING, THEREFORE
VERTICAL MIXING SHOULD BE LIMITED IN GENERAL OVER THE COLD WATER.
FRIDAY...SMALL CRAFT ADVISORY CONDITIONS EXPECTED. A SOUTHERLY FLOW
AHEAD OF A STRONG COLD FRONT WILL SHIFT TO THE NORTHWEST IN ITS WAKE
DURING THE AFTERNOON. THE 925 MB WINDS ARE FORECAST TO BE ABOUT 70
KNOTS AHEAD OF THE FRONT, THEREFORE IF MIXING CAN BE EFFICIENT
ENOUGH A PERIOD OF GALES WILL BE POSSIBLE. IN ADDITION, SOME
THUNDERSTORMS ARE POSSIBLE WITH EVEN THE CHC OF A LOW-TOPPED
CONVECTIVE LINE. THE WINDS AND SEAS ARE ANTICIPATED TO SUBSIDE AT
NIGHT.
SATURDAY AND SUNDAY...THE CONDITIONS SHOULD BE BELOW ADVISORY
CRITERIA SATURDAY AS A WEAKNESS IN THE PRESSURE FIELDS OCCUR. THE
CAA IS FORECAST TO INCREASE DURING SUNDAY, AND THIS MAY RESULT IN
WINDS INCREASING TO NEAR ADVISORY CRITERIA ESPECIALLY LATE.
&&
.HYDROLOGY...
CURRENT CONDITIONS...THE EXISTING SNOWPACK ON THE GROUND CONTAINS
3.0 TO 4.5 INCHES OF WATER OVER NORTHERN NEW JERSEY AND EASTERN
PENNSYLVANIA. 1.5 TO 3.0 INCHES OF WATER EXISTS WITHIN THE
SNOWPACK ACROSS CENTRAL NEW JERSEY. THERE ARE 1.5 INCHES OR LESS
OF WATER EQUIVALENT ACROSS SOUTHERN NEW JERSEY AND THE DELMARVA.
IN ADDITION, QUITE A FEW RIVERS AND LARGE STREAMS IN THE AREA
REMAIN ICE-COVERED IN SPOTS DUE TO THE SUSTAINED COLD TEMPERATURES
WE`VE BEEN EXPERIENCING SINCE DECEMBER. THIS COMBINATION OF STORED
WATER IN THE SNOWPACK AND ICE-COVERED WATERWAYS RAISES THE CONCERN
FOR POTENTIAL FLOODING.
PREDICTABILITY...SNOWMELT ALONE USUALLY DOESN`T CAUSE FLOODING IN
THIS PART OF THE COUNTRY. HOWEVER, GIVEN THAT THERE`S SO MUCH ICE IN
THE RIVERS THIS YEAR, THE WATER MELTING FROM THE SNOWPACK COULD
INCREASE THE FLOW TO SUCH AN EXTENT THAT THE ICE WILL BREAK AND JAMS
WILL FORM. ICE JAMS ARE NOT PREDICTABLE ALTHOUGH WE KNOW WHEN
TEMPERATURES WARM AND WATER LEVELS RISE, THEY ARE POSSIBLE.
SO, WHEN AND WHERE ICE JAMS MAY OCCUR ARE DIFFICULT TO PINPOINT,
ALTHOUGH MANY RIVERS AND STREAMS DO HAVE FAVORED SPOTS (BENDS IN THE
STREAM, BRIDGE ABUTMENTS, PIERS, THE HEAD OF A TIDE). SOMETIMES JAMS
DEVELOP AND DISSIPATE WITHOUT PROBLEMS, BUT SOMETIMES THEY CAUSE
MAJOR PROBLEMS. IF HEAVY RAIN OCCURS ON TOP OF A RIPE SNOWPACK (A
SNOWPACK JUST BEGINNING TO SHED WATER DUE TO MELT), THE COMBINATION
OF ADDED WATER PLUS WARMTH, WILL ACCELERATE THE MELTING PROCESS AND
INCREASE FLOODING CONCERNS. LARGE SNOWPACKS CAN MELT VERY QUICKLY
WHEN WARM, MOIST AIR MOVES OVER THEM AND RAIN FALLS ON TOP OF THEM.
THE JANUARY 1996 FLOOD EVENT AND THE APRIL 2005 EVENT SERVES AS
EXAMPLES. GUSTY WINDS COULD ALSO HELP TO ACCELERATE MELTING.
FORECAST...A WARM SPELL LASTING SEVERAL DAYS IS EXPECTED FROM TODAY
THROUGH SATURDAY, WHICH WILL SERVE TO SOFTEN AND MELT THE SNOWPACK.
SIGNIFICANT WIDESPREAD RAIN IS NOT EXPECTED THIS WEEK, ALTHOUGH SOME
THUNDERSTORMS ON FRIDAY COULD PRODUCE AN INCH OR SO OF RAIN IN A
VERY SHORT PERIOD OF TIME IN ISOLATED SPOTS. THE WARM TEMPERATURES
WILL ALSO SOFTEN THE RIVER ICE, MAKING IT EASIER TO BREAK.
WE NEED TO KEEP AN EYE ON ALL THESE ELEMENTS, WARMING TEMPERATURES,
MELTING SNOWPACK, MELTING RIVER ICE, AND RAIN, BUT IT DOESN`T APPEAR
AT THIS VANTAGE POINT THAT THE COMBINED EFFECT OF ALL OF THESE
ELEMENTS WILL BE SEVERE ENOUGH TO CAUSE WIDESPREAD MAINSTEM RIVER
AND/OR LARGE STREAM FLOODING AT THE END OF THIS WEEK. A BIGGER ISSUE
WILL LIKELY BE STREET AND POOR DRAINAGE FLOODING DUE TO CLOGGED OR
RESTRICTED DRAINS, AS WELL AS SMALL CREEK AND STREAM FLOODING, THE
ONES THAT RESPOND MORE QUICKLY.
BUT EVENTUALLY, THE SNOW AND ICE WILL GO, IF NOT THIS WEEK, THAN
SOMETIME LATER THIS WINTER OR EARLY SPRING, AND HOPEFULLY AT A
METERED PACE. WE NEED TO BE VIGILANT FOR THE SIGNS OF FLOODING AS WE
MOVE FORWARD.
&&
.CLIMATE...
SEASONAL SNOW TOTALS AND RANKING SO FAR...
PHILADELPHIA...58.4 INCHES, WHICH RANKS #3. OFFICIAL RECORDS DATE
BACK TO 1872.
1. 78.7 2009-10
2. 65.5 1995-96
3. 58.4 2013-14
4. 55.4 1898-99
ALLENTOWN...66.7 INCHES, WHICH RANKS #4. OFFICIAL RECORDS DATE BACK
TO 1922.
1. 75.4 1993-94
2. 71.4 1995-96
3. 67.2 1966-67
4. 66.7 2013-14
5. 65.2 1960-61
WILMINGTON...47.9 INCHES, WHICH RANKS #4. OFFICIAL RECORDS DATE BACK
TO 1894.
1. 72.8 2009-10
2. 49.5 1957-58
3. 48.8 1906-07 (MISSING DAYS)
4. 47.9 2013-14
5. 46.1 2002-03
ATLANTIC CITY...27.5 INCHES, WHICH IS RANKED #18. OFFICIAL RECORDS
DATE BACK TO 1874.
FOR THE MONTH OF FEBRUARY...
PHILADELPHIA AT 21.3 INCHES, RANKED #7.
1. 51.5 2010
2. 31.5 1899
3. 29.6 2003
4. 27.6 1979
5. 26.1 1983
6. 24.1 1907
7. 21.3 2014
8. 19.0 1978
9/10 18.5 1967 AND 1934
ALLENTOWN AT 36.5 INCHES, RANKED #2 BEHIND THE 42.9 INCHES OF 2010.
WILMINGTON AT 18.5 INCHES, RANKED TIED #7 BEHIND THE #1 46.9 INCHES
OF 2010.
1. 46.9 2010
2. 31.6 2003
3. 27.6 1979
4. 26.3 1934 (MISSING 18 DAYS)
5 22.6 1895 (MISSING 21 DAYS)
6. 18.7 1967
7/8. 18.5 2014 AND 1983
9. 18.4 1978
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO NOON EST
TODAY FOR PAZ054-055-060>062.
FREEZING RAIN ADVISORY FROM 7 AM TO 10 AM EST THIS MORNING FOR
PAZ101>106.
NJ...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO NOON EST
TODAY FOR NJZ001-007-008.
FREEZING RAIN ADVISORY FROM 7 AM TO 10 AM EST THIS MORNING FOR
NJZ009-010-015.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO MIDNIGHT EST
TONIGHT FOR ANZ450>455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...GORSE
AVIATION...GORSE/NIERENBERG
MARINE...GORSE/NIERENBERG
HYDROLOGY...MIKETTA/KRUZDLO
CLIMATE...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
441 AM EST WED FEB 19 2014
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL REMAIN STALLED OVER THE AREA THROUGH
FRIDAY. ON FRIDAY A STRONG COLD FRONT WITH CHANCES OF SHOWERS AND
THUNDERSTORMS WILL CROSS THE AREA WITH HIGH PRESSURE AND DRIER AIR
BUILDING INTO THE REGION FRIDAY EVENING.
&&
.NEAR TERM /THROUGH TONIGHT/...
WARM FRONT HAS CROSSED THE FORECAST AREA WITH SHOWERS AND
THUNDERSTORMS MOVING NORTHEASTWARD AWAY FROM THE AREA. HIGH
PRESSURE WILL BUILD BACK INTO THE REGION THIS AFTERNOON PUSHING
THE FRONTAL BOUNDARY BACK SOUTHWARD. DRIER AIR WILL MIX WITH THE
FRONTAL BOUNDARY AS IT MOVES SOUTHWARD RESULTING IN DIMINISHING
CLOUDS WITH NO RAIN EXPECTED. WINDS THROUGH THIS AFTERNOON WILL
BE AROUND 15 MPH WITH GUSTS TO 25 MPH THEN DIMINISH THIS EVENING
AS THE PRESSURE GRADIENT WEAKENS WITH HIGH PRESSURE BUILDING IN.
OVERNIGHT CLOUDS WILL BEGIN TO INCREASE AS SOUTHERLY FLOW
OVERTAKES THE REGION AND THE BOUNDARY SLIDES SLIGHTLY NORTHWARD.
TEMPERATURES THIS AFTERNOON WILL TOP OUT IN THE MIDDLE 70S FOR
MOST LOCATIONS WITH OVERNIGHT LOWS TONIGHT IN THE LOWER 50S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
LOW PRESSURE WILL DEEPEN AS IT CROSSES THE MID MS VALLEY THURSDAY
AFTERNOON THEN TRACKS INTO THE WESTERN GREAT LAKES THURSDAY NIGHT.
THIS WILL PUSH AN ASSOCIATED COLD FRONT ACROSS THE GULF STATES
THURSDAY NIGHT AND INTO THE FORECAST AREA FRIDAY MORNING. BY
FRIDAY 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 AND
WILL CONTINUE TO MONITOR. HIGH TEMPERATURES WILL BE IN THE MID 70S
TO AROUND 80 THURSDAY WITH MID 60S TO AROUND 70 FOR THURSDAY AND
OVERNIGHT LOWS THURSDAY NIGHT AROUND 60 FALLING TO THE UPPER 30S
TO MID 40S FOR FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MODELS THROUGH THE LONG TERM ARE IN GOOD AGREEMENT WITH THE
SYNOPTIC PATTERN...HOWEVER HAVE SIGNIFICANT DIFFERENCES IN TIMING
OF MOISTURE ACROSS THE REGION. HIGH PRESSURE AND DRIER AIR WILL
DOMINATE THE REGION FOR SATURDAY AND SUNDAY WITH THE REMAINS OF
FRONTAL BOUNDARY SOUTH OF THE AREA SLIDING NORTHWARD SUNDAY NIGHT
AND MONDAY. ECMWF BUILDS HIGH PRESSURE INTO THE FORECAST AREA
MONDAY EVENING WHILE THE GFS BRINGS THE FRONTAL BOUNDARY FURTHER
NORTHWARD. THE UNCERTAINTY CONTINUES THROUGH THE REMAINDER OF THE
LONG TERM RESULTING IN LOW CONFIDENCE AND ONLY MINOR ADJUSTMENTS
TO MONDAY THROUGH TUESDAY. TEMPERATURES THROUGH THE LONG TERM WILL
BE NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
MAINLY MID AND HIGH LEVEL CLOUDS MOVING ACROSS THE AREA. LOWER
CLOUDS ACROSS NORTH GEORGIA INTO SOUTH CAROLINA PIEDMONT. WARM FRONT
HAS MOVED NORTH OF THE REGION. THREAT OF SHOWERS APPEARS LOW. LOW
LEVEL SOUTHWEST WINDS WILL BE INCREASING DURING THE
MORNING...REDUCING FOG THREAT. LATEST HRRR AND LAMP SUGGEST IFR
CEILINGS MORE LIKELY WILL REMAIN WEST OF THE TERMINALS. BRIEF
PERIOD OF MVFR FORECAST THIS MORNING BUT CONFIDENCE LOW. VFR ALL
AREAS BY 15Z WITH GUSTY SOUTHWEST WINDS ABOVE 20 KTS AT TIMES
THROUGH THE EARLY AFTERNOON. DIMINISHING WINDS LATE.
EXTENDED AVIATION OUTLOOK...VSBY/CEILING FOG RESTRICTIONS
POSSIBLE EARLY THURSDAY MORNING. RESTRICTIONS POSSIBLE THURSDAY
NIGHT AND FRIDAY AS A STRONG COLD FRONT MOVES THROUGH THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1238 AM EST WED FEB 19 2014
.SYNOPSIS...
A WARM FRONT WILL MOVE NORTH THROUGH THE REGION LATE TONIGHT THEN
STALL AND MEANDER ACROSS THE REGION OVER THE NEXT COUPLE OF DAYS
UNTIL A STRONG COLD FRONT FINALLY EJECTS IT FROM THE REGION ON
FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
UPDATE...ONGOING FORECAST CONTINUES TO APPEARS ON TRACK. EXPECT
INCREASING CLOUDINESS...WITH A CHANCE OF SHOWERS AND POSSIBLY A
THUNDERSTORM LATE TONIGHT. LATEST RADAR MOSAIC AND LIGHTNING
DISPLAY INDICATES A BAND OF SCATTERED SHOWERS WITH AN ISOLATED
THUNDERSTORM STRETCHING FROM N GA SE TOWARDS THE CSRA. ACTIVITY
MOVING TO THE ENE.
UPPER TROUGH WILL MOVE INTO THE EASTERN CONUS TONIGHT. COLD FRONT
WILL MOVE EAST ACROSS THE MIDWEST AND OHIO VALLEY TONIGHT...LEADING
TO AN INCREASED SW LOW LEVEL FLOW DOWN TO THE GULF COAST. THIS
WILL CAUSE A WARM FRONT TO OUR SW TO SHIFT NE THROUGH OUR REGION
LATE TONIGHT. AN UPPER IMPULSE WILL RIDE THROUGH OUR REGION AS
WELL LATE TONIGHT. HIGH RESOLUTION MODELS INDICATE PRECIPITATION
DEVELOPING ALONG THE WARM FRONT AND MOVING NE INTO...OR DEVELOPING
OVER...MAINLY NORTHERN PORTIONS OF THE CSRA AROUND OR AFTER
MIDNIGHT...WITH PRECIPITATION COVERAGE AND INTENSITY INCREASING
AND SPREADING EAST ACROSS THE REMAINDER OF THE FA...MAINLY
NORTH...LATE TONIGHT...EXITING THE NE/E FA AROUND DAYBREAK. WEAK
SURFACE BASED INSTABILITIES AND BEST MOISTURE TRANSPORT APPEAR TO
REMAIN MAINLY TO OUR WEST...WITH MAINLY WEAK ELEVATED INSTABILITIES
OVER OUR FA. POTENTIAL EXISTS FOR ISOLATED TO WIDELY SCATTERED
THUNDER ACCOMPANYING THE SHOWER ACTIVITY...GENERALLY FAVORING THE
NORTHERN FA. MIN TEMPS TONIGHT COULD BE APPROACHED EARLY...WITH
POTENTIAL FOR STEADY OR POSSIBLY EVEN SOME RISING TEMPS LATE
TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
THE WARM FRONT WILL BE JUST NORTH OF THE MIDLANDS WEDNESDAY. KEPT
SLIGHT CHANCE POPS ACROSS THE NORTHERN MIDLANDS GIVEN THE
PROXIMITY TO THE FRONTAL BOUNDARY. OTHERWISE WE EXPECT PARTIAL
CLEARING FROM THE SOUTH AND MODERATE SOUTHWEST WINDS 10 TO 15 MPH.
OUR WARMING TREND WILL CONTINUE WITH HIGHS IN THE LOW TO MID 70S.
WEDNESDAY NIGHT THROUGH THURSDAY... AN UPPER LEVEL TROUGH WILL
DEVELOP OVER THE CENTRAL CONUS WEDNESDAY NIGHT INTO THURSDAY WITH
DOWNSTREAM RIDGING OVER THE EASTERN CONUS. AT THE SURFACE...THE
LINGERING WARM FRONT WILL LIFT NORTH ACROSS THE NORTHERN PART OF
THE FORECAST AREA WEDNESDAY NIGHT. A LOW WILL DEVELOP OVER THE
CENTRAL PLAINS BY WEDNESDAY NIGHT AND WILL RAPIDLY SHIFT NORTH-
NORTHEASTWARD AND DEEPEN ON THURSDAY WITH A TRAILING COLD FRONT.
SURFACE HIGH PRESSURE CENTERED OVER THE OHIO VALLEY WEDNESDAY
NIGHT WILL BE PUSHED OFFSHORE ON THURSDAY AS THE LOW PROGRESSES.
EXPECT THE COLD FRONT TO APPROACH THE OHIO AND TENNESSEE VALLEYS
BY THURSDAY EVENING WITH POSSIBLE LINEAR CONVECTION ALONG THE
FRONT. TEMPERATURES WILL CONTINUE TO WARM FOR THURSDAY WITH
OVERNIGHT LOWS IN THE UPPER 40S TO LOWER 50S WEDNESDAY NIGHT AND
LOWER TO UPPER 70S FOR AFTERNOON HIGHS.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...UPPER TROUGH WILL TRACK
TOWARD THE GREAT LAKES THURSDAY NIGHT AND DEEPEN WITH THE COLD
AT THE LEADING EDGE OF THE TROUGHING. WINDS WILL INCREASE LATE
THURSDAY INTO FRIDAY AS THE PRESSURE GRADIENT TIGHTENS. EXPECT THE
COLD FRONT TO EXTEND THROUGH THE LEE OF THE APPALACHIANS BY 12Z
FRIDAY MORNING. AS THE VIGOROUS FRONT CROSSES THE REGION...A LINE
OF CONVECTION MAY REDEVELOP. A HIGH SHEAR LOW CAPE SCENARIO IS
POSSIBLE ALTHOUGH INSTABILITY APPEARS LIMITED AT THIS TIME. AMOUNT
OF INSTABILITY WILL DEPEND ON THE TIMING OF THE FRONT AND AMOUNT
OF CLOUD COVER AND HEATING. DRY AIR MOVING IN BEHIND THE FRONT IS
ALSO A CONCERN. ECMWF IS A LITTLE SLOWER WITH THE TIMING OF THE
FRONT WHICH COULD RESULT IN MORE INSTABILITY. THE HIGHEST CHANCE OF
RAIN WILL BE WITH THE FRONTAL PASSAGE FRIDAY MORNING/EARLY
AFTERNOON. MODELS SHOW THE COLD FRONT EAST OF THE FORECAST AREA
FRIDAY EVENING.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
UNCERTAINTY REMAINS IN THE LONG TERM FORECAST WITH SIGNIFICANT
MODEL DIFFERENCES SUNDAY THROUGH MONDAY. AN UPPER RIDGE WILL BUILD
OVER THE WESTERN CONUS WITH BROAD TROUGHING OVER THE EASTERN
CONUS. THE FRONT WILL STALL ALONG THE COAST ON SATURDAY WITH
SURFACE HIGH PRESSURE AND DRIER AIR RIDGING IN BEHIND IT. WITH
CONFIDENCE LOW FOR SUNDAY AND MONDAY HAVE ONLY MADE MINOR
ADJUSTMENTS TO THE FORECAST BY BLENDING WITH LATEST WPC GUIDANCE.
EXPECT A GRADUAL COOLING TREND WITH TEMPERATURES. LATEST GUIDANCE
TRENDED DOWN WITH TEMPERATURES FOR MONDAY AND TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
MID AND HIGH LEVEL CLOUDS MOVING ACROSS THE AREA. WARM FRONT
LIFTING NORTHEAST ACROSS THE REGION OVERNIGHT. BASED ON RADAR
TRENDS...RAIN THREAT APPEARS LOW AS FOCUS FOR CONVECTION SHIFTING
TO THE NORTH OF TERMINALS. HRRR AND LATEST NAM/RAP FORECAST
SOUNDINGS SUGGEST STRATUS OR STRATO-CU THREAT TOWARD MORNING WHICH
MAY RESULT IN IFR CEILINGS FOR A PERIOD FROM 10Z TO 13Z.
CONFIDENCE IS LOW HOWEVER AND NOT SUPPORTED BY LATEST LAMP. VFR
EXPECTED BY 15Z WITH GUSTY SOUTHWEST WINDS ABOVE 20 KTS AT TIMES
THROUGH THE EARLY AFTERNOON. DIMINISHING WINDS LATE.
EXTENDED AVIATION OUTLOOK...VSBY/CEILING FOG RESTRICTIONS
POSSIBLE EARLY THURSDAY MORNING. RESTRICTIONS POSSIBLE THURSDAY
NIGHT AND FRIDAY AS A STRONG COLD FRONT MOVES THROUGH THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1217 AM MST WED FEB 19 2014
.UPDATE...
ISSUED AT 948 PM MST TUE FEB 18 2014
UPDATED THE FORECAST FOR LATEST THINKING ON THE UPCOMING WIND AND
SNOW EVENT TOMORROW NIGHT. MAINTAINED/REFRESHED THE WSW...HWO AND
ZFP BY UPDATING THE TIMING OF THE RAIN/SNOW TRANSITION AND THE
ARRIVAL OF STRONGEST WINDS/ASSOCIATED BLOWING SNOW THREAT.
PRESSURE RISES BEHIND THE COLD FRONT WEDNESDAY EVENING/NIGHT ARE
VERY IMPRESSIVE...ON THE ORDER OF 12-16 MB OVER 3-6 HOURS. THIS ONLY
INCREASES CONFIDENCE IN PROBLEMS WITH STRONG WINDS TOMORROW NIGHT. MODELS
BRING PRECIPITATION INTO THE AREA BEHIND THE FRONT WITHOUT MUCH
AHEAD OF IT. THIS IS DUE TO SOME DRY AIR AT THE LOW LEVELS AND
ALOFT WITH A DRY AIR INTRUSION. BEHIND THE FRONT...THE ATMOSPHERIC
PROFILE SATURATES AND PRECIPITATION WILL BEGIN TO REACH THE
GROUND. IT SEEMS THERE WILL BE A STRONG BAND OF SNOW THAT WILL
DEVELOP BEHIND THE FRONT AND TRANSITION ACROSS THE AREA FAIRLY
QUICKLY. UNDER THE BAND...SNOWFALL RATES AND WINDS WILL BRING
PROBLEMS WITH BLOWING SNOW AND DRIFTING. VISIBILITIES WILL BE NEAR
ZERO AT TIMES. DUE TO THE QUICK MOVEMENT OF THE BAND...SNOWFALL
AMOUNTS ARE NOT EXPECTED TO BE NEARLY AS HIGH AS RECENT BANDED
SNOWFALL EVENTS. AT THIS POINT...ONE TO THREE INCHES OF SNOW IS
EXPECTED WITH THE POTENTIAL TO SEE CLOSER TO 4 INCHES OVER
SOUTHWEST NEBRASKA. VERY COMPLICATED SCENARIO AS THE WINDS MAY
APPROACH HIGH WIND WARNING CRITERIA BUT BLIZZARD CONDITIONS MAY
NOT BE MET FOR THE FULL THREE HOUR REQUIREMENT. THEREFORE...THE
ADVISORY WAS ISSUED AS WINTER STORM CRITERIA WOULD NOT BE MET AS
WELL. HIGHLIGHT CHANGES MAY BE NEEDED CLOSER TO THE EVENT
DEPENDING ON DURATION OF HEAVIER SNOW AND THUS LOWER VISIBILITIES
OR THE STRENGTH OF THE WINDS.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 145 PM MST TUE FEB 18 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS INDICATE SHORTWAVE TROUGH OVER
EASTERN NEBRASKA/KANSAS WITH SHORTWAVE RIDGE OVER THE GREAT BASIN
AND NORTHERN ROCKIES. A COLD FRONT (WHICH SHOWS UP BETTER WITH
VERTICAL THICKNESS FIELD) IS MOVING SOUTH TO THE KS/NE BORDER WITH A
PREFRONTAL SURFACE TROUGH AXIS NOW ACROSS CENTRAL KANSAS.
THIS AFTERNOON...STRONG PRESSURE GRADIENT HAS LED TO DEVELOPMENT OF
WIND GUSTS 45-60 MPH ACROSS THE NORTHERN HALF OF THE CWA...WITH
WINDS JUST STARTING TO COME UP ACROSS THE EAST AND SOUTH OVER THE
LAST HOUR. STRONGEST GUSTS WERE ASSOCIATED WITH INITIAL SURGE AS
SURFACE TROUGH SHIFTED SOUTH AND 3HR PRESSURE RISES BEHIND COLD
FRONT PEAKED AROUND 4MB. WINDS HAVE STABILIZED WITHIN ADVISORY
CRITERIA AFTER THIS INITIAL SURGE...SO DECISION WAS MADE TO HOLD
ONTO ADVISORY. RED FLAG CONDITIONS ARE BEING MET AT MOST OF WARNED
AREA...THOUGH INCREASING TD VALUES FROM THE NORTH ARE KEEPING RH
VALUES CLOSER TO 30 PERCENT ACROSS THE NORTHERN PART OF THE RFW. WE
MAY NOT MEET THE HIGH END THRESHOLD FOR RED FLAG CONDITIONS...
HOWEVER WITH THE MAGNITUDE OF WIND...I SEE NO REASON TO MAKE A CHANGE
TO GOING HEADLINES AT THIS POINT. RFW/NPW WILL CONTINUE THROUGH 01Z.
TONIGHT-WEDNESDAY...WINDS WILL QUICKLY DECREASE WITH LOSS OF DAYTIME
MIXING AND WEAKENING GRADIENT THIS EVENING. HIGH CLOUD COVER MOVING
IN FROM THE WEST LATER THIS EVENING MAY LIMIT RADIATIONAL COOLING
TONIGHT AND DIURNAL HEATING WEDNESDAY. LEE TROUGH ALSO REDEVELOPS
AFTER MIDNIGHT TONIGHT IN RESPONSE TO STRONG TROUGH MOVING OUT OF
THE PACIFIC NORTHWEST...WITH RESULTING SOUTHERLY FLOW SUPPORTING WAA
ACROSS THE WEST. I BUMPED LOW TEMPS UP TONIGHT AND HIGH TEMPS UP WED
FOR NOW...AND COULD SEE BOTH PERIODS BEING A LITTLE WARMER/COOLER
THAN ADVERTISED DEPENDING ON CLOUDS. OTHER IMMEDIATE CONCERN WILL BE
BREEZY-WINDY CONDITIONS WEDNESDAY AS SOUTHERLY GRADIENT INCREASE
AHEAD OF APPROACHING UPPER LEVEL SYSTEM. MODEL TEMPERATURE PROFILES
INDICATE MIXING HEIGHTS AROUND 750MB-800MB WHICH KEEPS WINDS JUST
UNDER (OR NEAR) ADVISORY CRITERIA...AND WITH CLOUD COVER POSSIBLY
LIMITING MIXING OVERALL...I DECIDED AGAINST ISSUANCE OF ANOTHER
ADVISORY WED AFTERNOON. UPPER LEVEL SYSTEM DOES APPROACH CENTRAL
ROCKIES WED AFTERNOON AND SURFACE TROUGH WILL SHIFT EAST ALLOWING
WINDS TO DECREASE LATER IN THE AFTERNOON. WHILE FORCING DOES BEGIN
TO INCREASE OVER THE ROCKIES...IT CURRENTLY LOOKS LIKE PRECIP
CHANCES SHOULD HOLD OFF UNTIL WED EVENING.
.LONG TERM...(SATURDAY THROUGH NEXT WEDNESDAY)
ISSUED AT 1211 AM MST WED FEB 19 2014
A TROUGH WILL BE LOCATED OVER THE NORTHERN PLAINS THROUGH MOST OF
THE LONG TERM PERIOD WITH A SERIES OF SHORTWAVE TROUGHS ROTATING
THROUGH. AS A RESULT...TEMPERATURES WILL BE BELOW NORMAL WITH
OCCASIONAL CHANCES OF MAINLY LIGHT WINTRY PRECIPITATION. NONE OF
THESE SYSTEMS APPEAR TO HAVE ENOUGH UPPER SUPPORT FOR MORE THAN AN
INCH OR SO OF SNOW. SOME MIXED PRECIPITATION WILL BE POSSIBLE ON
SATURDAY WITH TEMPERATURES NEAR OR SLIGHTLY ABOVE FREEZING. A
FAIRLY STRONG COLD FRONT WILL MOVE THROUGH ON MONDAY WITH GUSTY
NORTH WINDS AND COLDEST TEMPERATURES OF THE PERIOD. HOWEVER...THE
COLDEST AIR WILL REMAIN IN THE NORTHERN PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1030 PM MST TUE FEB 18 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH CEILINGS
LOWERING NEAR THE END OR AFTER THE TAF PERIOD BEHIND THE NEXT COLD
FRONT. CURRENTLY...SURFACE HIGH PRESSURE OVER THE REGION IS ALLOWING
WINDS TO REMAIN LIGHT AND VARIABLE TO CALM. WINDS WILL BECOME
SOUTHERLY AS THE SURFACE HIGH DEPARTS AND A LEE SIDE SURFACE LOW
DEVELOPS OVER EASTERN COLORADO. SOUTHERLY WINDS WILL BECOME BREEZY
AT 16 KTS WITH GUSTS AROUND 20 TO 25 KTS FOR BOTH SITES. KGLD COULD
SEE HIGHER GUSTS AROUND 31 KTS AROUND 18Z. THE COLD FRONT WILL MOVE
THROUGH KGLD FIRST AROUND 04Z...WITH WINDS SHIFTING TO THE NORTHEAST
AND EVENTUALLY NORTH GUSTING TO AROUND 25 KTS. NAM BUFKIT SOUNDINGS
INDICATE THAT THERE WILL BE A CHANCE FOR LIGHT RAIN AT KGLD AT
04Z...BUT SINCE EXACT TIMING OF SHOWERS MOVING OVER THE TERMINAL IS
HARD TO PIN DOWN THIS FAR OUT...WENT WITH VCSH. KMCK SHOULD SEE
AFTERNOON GUSTS DIMINISH AROUND 0Z WITH SOUTHEAST WINDS...BUT THE
COLD FRONT SHOULD MOVE THROUGH KGLD FIRST SO DID NOT THINK VCSH
WOULD BE NEAR KMCK BEFORE THE END OF THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ THIS EVENING TO
6 AM MST /7 AM CST/ THURSDAY FOR KSZ001-002-013-027.
WINTER WEATHER ADVISORY FROM 10 PM MST /11 PM CST/ THIS EVENING
TO 6 AM MST /7 AM CST/ THURSDAY FOR KSZ003-004-014>016-028-
029-041-042.
CO...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 6 AM MST
THURSDAY FOR COZ090>092.
NE...WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ THIS EVENING TO
6 AM MST /7 AM CST/ THURSDAY FOR NEZ079>081.
&&
$$
UPDATE...RRH
SHORT TERM...DJR
LONG TERM...024
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1030 PM MST TUE FEB 18 2014
.UPDATE...
ISSUED AT 948 PM MST TUE FEB 18 2014
UPDATED THE FORECAST FOR LATEST THINKING ON THE UPCOMING WIND AND
SNOW EVENT TOMORROW NIGHT. MAINTAINED/REFRESHED THE WSW...HWO AND
ZFP BY UPDATING THE TIMING OF THE RAIN/SNOW TRANSITION AND THE
ARRIVAL OF STRONGEST WINDS/ASSOCIATED BLOWING SNOW THREAT.
PRESSURE RISES BEHIND THE COLD FRONT WEDNESDAY EVENING/NIGHT ARE
VERY IMPRESSIVE...ON THE ORDER OF 12-16 MB OVER 3-6 HOURS. THIS ONLY
INCREASES CONFIDENCE IN PROBLEMS WITH STRONG WINDS TOMORROW NIGHT. MODELS
BRING PRECIPITATION INTO THE AREA BEHIND THE FRONT WITHOUT MUCH
AHEAD OF IT. THIS IS DUE TO SOME DRY AIR AT THE LOW LEVELS AND
ALOFT WITH A DRY AIR INTRUSION. BEHIND THE FRONT...THE ATMOSPHERIC
PROFILE SATURATES AND PRECIPITATION WILL BEGIN TO REACH THE
GROUND. IT SEEMS THERE WILL BE A STRONG BAND OF SNOW THAT WILL
DEVELOP BEHIND THE FRONT AND TRANSITION ACROSS THE AREA FAIRLY
QUICKLY. UNDER THE BAND...SNOWFALL RATES AND WINDS WILL BRING
PROBLEMS WITH BLOWING SNOW AND DRIFTING. VISIBILITIES WILL BE NEAR
ZERO AT TIMES. DUE TO THE QUICK MOVEMENT OF THE BAND...SNOWFALL
AMOUNTS ARE NOT EXPECTED TO BE NEARLY AS HIGH AS RECENT BANDED
SNOWFALL EVENTS. AT THIS POINT...ONE TO THREE INCHES OF SNOW IS
EXPECTED WITH THE POTENTIAL TO SEE CLOSER TO 4 INCHES OVER
SOUTHWEST NEBRASKA. VERY COMPLICATED SCENARIO AS THE WINDS MAY
APPROACH HIGH WIND WARNING CRITERIA BUT BLIZZARD CONDITIONS MAY
NOT BE MET FOR THE FULL THREE HOUR REQUIREMENT. THEREFORE...THE
ADVISORY WAS ISSUED AS WINTER STORM CRITERIA WOULD NOT BE MET AS
WELL. HIGHLIGHT CHANGES MAY BE NEEDED CLOSER TO THE EVENT
DEPENDING ON DURATION OF HEAVIER SNOW AND THUS LOWER VISIBILITIES
OR THE STRENGTH OF THE WINDS.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 145 PM MST TUE FEB 18 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS INDICATE SHORTWAVE TROUGH OVER
EASTERN NEBRASKA/KANSAS WITH SHORTWAVE RIDGE OVER THE GREAT BASIN
AND NORTHERN ROCKIES. A COLD FRONT (WHICH SHOWS UP BETTER WITH
VERTICAL THICKNESS FIELD) IS MOVING SOUTH TO THE KS/NE BORDER WITH A
PREFRONTAL SURFACE TROUGH AXIS NOW ACROSS CENTRAL KANSAS.
THIS AFTERNOON...STRONG PRESSURE GRADIENT HAS LED TO DEVELOPMENT OF
WIND GUSTS 45-60 MPH ACROSS THE NORTHERN HALF OF THE CWA...WITH
WINDS JUST STARTING TO COME UP ACROSS THE EAST AND SOUTH OVER THE
LAST HOUR. STRONGEST GUSTS WERE ASSOCIATED WITH INITIAL SURGE AS
SURFACE TROUGH SHIFTED SOUTH AND 3HR PRESSURE RISES BEHIND COLD
FRONT PEAKED AROUND 4MB. WINDS HAVE STABILIZED WITHIN ADVISORY
CRITERIA AFTER THIS INITIAL SURGE...SO DECISION WAS MADE TO HOLD
ONTO ADVISORY. RED FLAG CONDITIONS ARE BEING MET AT MOST OF WARNED
AREA...THOUGH INCREASING TD VALUES FROM THE NORTH ARE KEEPING RH
VALUES CLOSER TO 30 PERCENT ACROSS THE NORTHERN PART OF THE RFW. WE
MAY NOT MEET THE HIGH END THRESHOLD FOR RED FLAG CONDITIONS...
HOWEVER WITH THE MAGNITUDE OF WIND...I SEE NO REASON TO MAKE A CHANGE
TO GOING HEADLINES AT THIS POINT. RFW/NPW WILL CONTINUE THROUGH 01Z.
TONIGHT-WEDNESDAY...WINDS WILL QUICKLY DECREASE WITH LOSS OF DAYTIME
MIXING AND WEAKENING GRADIENT THIS EVENING. HIGH CLOUD COVER MOVING
IN FROM THE WEST LATER THIS EVENING MAY LIMIT RADIATIONAL COOLING
TONIGHT AND DIURNAL HEATING WEDNESDAY. LEE TROUGH ALSO REDEVELOPS
AFTER MIDNIGHT TONIGHT IN RESPONSE TO STRONG TROUGH MOVING OUT OF
THE PACIFIC NORTHWEST...WITH RESULTING SOUTHERLY FLOW SUPPORTING WAA
ACROSS THE WEST. I BUMPED LOW TEMPS UP TONIGHT AND HIGH TEMPS UP WED
FOR NOW...AND COULD SEE BOTH PERIODS BEING A LITTLE WARMER/COOLER
THAN ADVERTISED DEPENDING ON CLOUDS. OTHER IMMEDIATE CONCERN WILL BE
BREEZY-WINDY CONDITIONS WEDNESDAY AS SOUTHERLY GRADIENT INCREASE
AHEAD OF APPROACHING UPPER LEVEL SYSTEM. MODEL TEMPERATURE PROFILES
INDICATE MIXING HEIGHTS AROUND 750MB-800MB WHICH KEEPS WINDS JUST
UNDER (OR NEAR) ADVISORY CRITERIA...AND WITH CLOUD COVER POSSIBLY
LIMITING MIXING OVERALL...I DECIDED AGAINST ISSUANCE OF ANOTHER
ADVISORY WED AFTERNOON. UPPER LEVEL SYSTEM DOES APPROACH CENTRAL
ROCKIES WED AFTERNOON AND SURFACE TROUGH WILL SHIFT EAST ALLOWING
WINDS TO DECREASE LATER IN THE AFTERNOON. WHILE FORCING DOES BEGIN
TO INCREASE OVER THE ROCKIES...IT CURRENTLY LOOKS LIKE PRECIP
CHANCES SHOULD HOLD OFF UNTIL WED EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 224 PM MST TUE FEB 18 2014
FORECAST CONCERNS WILL BE WINDS THROUGH FRIDAY AND PRECIPITATION
CHANCE/PHASE WEDNESDAY NIGHT. SATELLITE SHOWING A PROGRESSIVE AND
ACTIVE WAVE TRAIN FROM THE PACIFIC INTO THE ATLANTIC. NEXT SHORTWAVE
OF INTEREST IS ENTERING THE PACIFIC NORTHWEST. VERY DRY AIR MASS
ALOFT AT THIS TIME.
AT JET LEVEL...MODELS STARTED OUT FINE. AT MID LEVELS...LOOKS TO BE
NO SERIOUS INITIALIZATION PROBLEMS WITH THE MODELS MAYBE A LITTLE
TOO FAR SOUTH AND EAST. AT THIS TIME...THE ECMWF...CANADIAN...UKMET
AND GFS APPEAR TO BE DOING SLIGHTLY BETTER. ECMWF AND SREF WERE
DOING WELL INITIALLY WITH THE SURFACE WIND AND PRESSURE PATTERN.
THE CANADIAN...UKMET AND GFS WERE DOING THE BEST WITH THE LOW LEVEL
THERMAL FIELD.
WEDNESDAY NIGHT...AREA TRANSITIONS FROM WARM...DRY AND WINDY TO
COLD...WET AND WINDY. THERE ARE SOME DIFFERENCES IN THE JET AND
TROUGH POSITION. SOME MODELS HAVE THE LEFT FRONT QUADRANT WELL
SOUTH...AFFECTING THE SOUTHERN HALF OF THE AREA OR STILL TO THE WEST
OF THE AREA. BY THE MIDDLE OF THE NIGHT...THE JET AXIS HAS MOVED
ACROSS WITH THE MAIN AFFECT FROM THE LEFT FRONT QUADRANT ACROSS THE
SOUTHERN HALF OF THE AREA THROUGH THE EVENING. VERY STRONG
FRONTOGENETICAL FORCING MOVES ACROSS THE AREA FROM EARLY IN THE
EVENING TO LATE IN THE NIGHT. THETA-E LAPSE RATES NEAR ZERO OR
SLIGHTLY BELOW ZERO ARE NOT ONLY AT MID LEVELS FOR THE ENTIRE NIGHT
BUT FOR A BRIEF PERIOD ARE AT LOW LEVELS.
SO THE LIKELIHOOD OF PRECIPITATION IS PRETTY HIGH. THE QUESTION
BECOMES WHEN WILL THE PHASE CHANGE FROM RAIN TO SNOW AND HOW MUCH
SNOW WILL OCCUR AFTER THIS HAPPENS. MODEL SOUNDINGS AND WET BULB
PROGS WOULD INDICATE THE NORTHWEST HALF WILL TRANSITION FROM A
RAIN/SNOW MIX EARLY TO ALL SNOW BY 06Z. THE SOUTHEAST HALF WILL
HAVE RAIN UNTIL NEAR 05-06Z BEFORE RAPIDLY CHANGING TO SNOW.
PRECIPITABLE WATER NEARS A HALF INCH OVER THE EASTERN HALF TO TWO
THIRDS OF THE AREA. LIKE THE REPRESENTATION OF QPF THAT WPC HAS AND
USED AS A THE BUILDING BLOCK FOR THE QPF AND SNOWFALL. WPC SLR
GUIDANCE WOULD INDICATE A NEAR 13 TO 1 RATIO IS NEAR NORMAL AND THAT
SEEMS REASONABLE. SO CONSIDERING THE FORCING AND INSTABILITY...THE
SNOW COULD BE RATHER INTENSE AT TIMES DURING THE NIGHT.
SO WITH USING THE WPC QPF AND CUTTING OFF A LITTLE BIT DUE TO THE
EXPECTED PHASE TO BE RAIN...CAME UP WITH 1 TO 4 INCHES WITH THE
LOWEST IN THE FAR SOUTH AND THE MOST FROM YUMA COUNTY TO THE COUNTIES
ALONG THE KANSAS AND NEBRASKA BORDER.
ALL INDICATIONS ARE THAT VERY WINDY CONDITIONS WILL BE A CERTAINTY.
EXTREMELY TIGHT PRESSURE GRADIENT AND 3 HOUR PRESSURE RISES OF NEAR
10 MB WILL PRODUCE VERY WINDY CONDITIONS. AND THAT IS NOT EVEN
CONSIDERING THE POSSIBILITY OF MIXING DOWN EVEN STRONGER WINDS.
THOUGHT LONG AND HARD ABOUT HOW TO HANDLE THIS SCENARIO. WINDS
SHOULD BE IN THE HIGH WIND ADVISORY TO LOW HIGH WIND WARNING RANGE.
SO DESPITE THE AMOUNT OF SNOW EXPECTED...SIGNIFICANT BLOWING OF THAT
SNOW IS EXPECTED. DUE TO HOW FAST THE SNOW MOVES ACROSS THE AREA...3
HOURS OF BLIZZARD CONDITIONS ARE NOT EXPECTED TO OCCUR WHICH WOULD
MEAN A BLIZZARD WARNING. AFTER PLENTY OF DISCUSSION WE HAVE DECIDED
TO ISSUE A WINTER WEATHER ADVISORY AND EMPHASIZE THAT NEAR BLIZZARD
OR BLIZZARD CONDITIONS COULD OCCUR FOR A SHORT PERIOD OF TIME WITH
VISIBILITIES OF A HALF MILE TO A MILE EXPECTED FOR MOST OF THE
PERIOD. SNOW SHOULD BE DONE BY THE END OF THE NIGHT PLUS THE WINDS
SHOULD GO DOWN BY THAT TIME. SO THE WINTER WEATHER ADVISORY WILL BE
FOR THE WHOLE NIGHT FOR THE NORTHWEST HALF AND FOR THE SOUTHEAST HALF
FOR THE LAST HALF OF THE NIGHT ENDING AT 6 TO 7 AM LOCAL TIME.
THURSDAY/THURSDAY NIGHT...SOME DIFFERENCES IN THE SPEED OF INCOMING
NORTH TO SOUTH JET...BUT IT LOOKS TO BE WEST OF THE AREA THROUGH
THE DAY. THAT SEGMENT FLATTENS OUT WITH A WEST TO EAST JET AXIS AND
RIGHT REAR QUADRANT OVER THE NORTHERN HALF OF THE AREA BY THE END
OF THE NIGHT. AT THIS TIME ALL THE MOISTURE IS ALOFT SO THIS WILL
ONLY CAUSE CLOUDS.
THE BIG PROBLEM WILL BE THAT WINDS WILL COME UP AGAIN DURING THE
DAY BEHIND THE EXITING SHORTWAVE TROUGH. QUESTIONS WILL BE HOW
MUCH MIXING WILL OCCUR...ESPECIALLY IN THE NORTH...DUE TO SNOW ON THE
GROUND. LOOK TO STAY MIXED THROUGH THE NIGHT. DURING THE DAY THERE IS
GOOD UNIDIRECTIONAL FLOW WITH DECENT DOWNWARD MOTION. MODELS SHOW
GOOD LAPSE RATES TO AT LEAST 700 MB. SO IT WOULD APPEAR THINGS WILL
MIX WELL. MODEL SOUNDINGS WOULD INDICATE AT LEAST WIND ADVISORY...
POSSIBLY HIGH END...AND POSSIBLY REACHING HIGH WIND WARNING
CRITERIA. SO WILL KEEP WINDY TO VERY WINDY CONDITIONS AND THIS WILL
NEED TO BE ADDRESSED AFTER THE WINTER WEATHER ADVISORY IS DONE.
DEPENDING ON THE AMOUNT OF SNOW AND HOW MUCH IF ANY THE SNOW CRUSTS
OVER...THERE COULD BE SOME MORE BLOWING SNOW DESPITE NO PRECIPITATION
OCCURRING. SO DID PUT IN PATCHY BLOWING SNOW AT THIS TIME. WILL PUT
MAXES IN NEAR TO SLIGHTLY BELOW GUIDANCE.
FRIDAY...ABOVE JET MOVES SOUTH ACROSS THE AREA AT VARIOUS SPEEDS AND
WILL BE NEAR OR JUST SOUTH OF THE AREA BY THE END OF THE DAY. THIS
JUST LOOKS TO PRODUCE SOME CLOUDS. MODELS SHOWING WIND SPEEDS
INCREASING INTO THE WINDY CATEGORY AGAIN. LAPSE RATES LOOK TO STILL
STAY GOOD BUT THE FLOW IS NOT AS UNIDIRECTIONAL AND THE DOWNWARD
MOTION IS NOT AS GREAT. BUFKIT SOUNDINGS ARE INDICATING THE MIXING
DOWN OF A LEAST WIND ADVISORY CRITERIA WINDS AGAIN. WILL DEFINITELY
TRY AND HAVE WINDY WORDING IN THERE AT THIS TIME. TEMPERATURES
SHOULD BE WARMER BUT NOT SURE DEPENDING ON THE AMOUNT OF SNOW ON THE
GROUND.
FRIDAY NIGHT THROUGH TUESDAY...AT END OF THE SHORT TERM INTO THE
BEGINNING OF THIS PERIOD...THE PATTERN TRANSITIONS FROM A
PROGRESSIVE FLOW TO A HIGH AMPLITUDE RIDGE ALONG THE WEST COAST OF
NORTH AMERICA AND HUDSON BAY LOW BECOMING ESTABLISHED ONCE AGAIN BY
THE END OF THE PERIOD. PRECIPITATION IS VERY HARD TO PIN DOWN. WILL
HAVE VERY FAST WEST TO NORTHWEST FLOW WITH EMBEDDED SHORTWAVE TROUGHS
AND JET ENERGY. SIGNIFICANT MOISTURE WILL BE HARD TO COME BY IN THIS
SCENARIO. HOWEVER CANNOT RULE OUT SOME BRIEF AND SPOTTY PRECIPITATION
CHANCES. SO LEFT THE CRH_INIT POPS ALONE WHICH WERE NO HIGHER THAN
SLIGHT CHANCE WHICH SEEMS REASONABLE.
COLDER TEMPERATURES LOOK TO BE COMING BACK. BY LATE IN THE WEEKEND
A SHALLOW COLD AIR MASS WILL BE IN PLACE AS A SURFACE RIDGE BECOMES
ESTABLISHED OVER THE NORTH CENTRAL PORTION OF THE COUNTRY. SO
FOLLOWED OTHER OFFICES AND MADE SLIGHT ADJUSTMENTS DOWN IN
TEMPERATURES...ESPECIALLY THE MAXES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1030 PM MST TUE FEB 18 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH CEILINGS
LOWERING NEAR THE END OR AFTER THE TAF PERIOD BEHIND THE NEXT COLD
FRONT. CURRENTLY...SURFACE HIGH PRESSURE OVER THE REGION IS ALLOWING
WINDS TO REMAIN LIGHT AND VARIABLE TO CALM. WINDS WILL BECOME
SOUTHERLY AS THE SURFACE HIGH DEPARTS AND A LEE SIDE SURFACE LOW
DEVELOPS OVER EASTERN COLORADO. SOUTHERLY WINDS WILL BECOME BREEZY
AT 16 KTS WITH GUSTS AROUND 20 TO 25 KTS FOR BOTH SITES. KGLD COULD
SEE HIGHER GUSTS AROUND 31 KTS AROUND 18Z. THE COLD FRONT WILL MOVE
THROUGH KGLD FIRST AROUND 04Z...WITH WINDS SHIFTING TO THE NORTHEAST
AND EVENTUALLY NORTH GUSTING TO AROUND 25 KTS. NAM BUFKIT SOUNDINGS
INDICATE THAT THERE WILL BE A CHANCE FOR LIGHT RAIN AT KGLD AT
04Z...BUT SINCE EXACT TIMING OF SHOWERS MOVING OVER THE TERMINAL IS
HARD TO PIN DOWN THIS FAR OUT...WENT WITH VCSH. KMCK SHOULD SEE
AFTERNOON GUSTS DIMINISH AROUND 0Z WITH SOUTHEAST WINDS...BUT THE
COLD FRONT SHOULD MOVE THROUGH KGLD FIRST SO DID NOT THINK VCSH
WOULD BE NEAR KMCK BEFORE THE END OF THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ WEDNESDAY TO 6
AM MST /7 AM CST/ THURSDAY FOR KSZ001-002-013-027.
WINTER WEATHER ADVISORY FROM 10 PM MST /11 PM CST/ WEDNESDAY TO
6 AM MST /7 AM CST/ THURSDAY FOR KSZ003-004-014>016-028-029-
041-042.
CO...WINTER WEATHER ADVISORY FROM 7 PM WEDNESDAY TO 6 AM MST THURSDAY
FOR COZ090>092.
NE...WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ WEDNESDAY TO 6
AM MST /7 AM CST/ THURSDAY FOR NEZ079>081.
&&
$$
UPDATE...RRH
SHORT TERM...DJR
LONG TERM...BULLER
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
948 PM MST TUE FEB 18 2014
.UPDATE...
ISSUED AT 948 PM MST TUE FEB 18 2014
UPDATED THE FORECAST FOR LATEST THINKING ON THE UPCOMING WIND AND
SNOW EVENT TOMORROW NIGHT. MAINTAINED/REFRESHED THE WSW...HWO AND
ZFP BY UPDATING THE TIMING OF THE RAIN/SNOW TRANSITION AND THE
ARRIVAL OF STRONGEST WINDS/ASSOCIATED BLOWING SNOW THREAT.
PRESSURE RISES BEHIND THE COLD FRONT WEDNESDAY EVENING/NIGHT ARE
VERY IMPRESSIVE...ON THE ORDER OF 12-16 MB OVER 3-6 HOURS. THIS ONLY
INCREASES CONFIDENCE IN PROBLEMS WITH STRONG WINDS TOMORROW NIGHT. MODELS
BRING PRECIPITATION INTO THE AREA BEHIND THE FRONT WITHOUT MUCH
AHEAD OF IT. THIS IS DUE TO SOME DRY AIR AT THE LOW LEVELS AND
ALOFT WITH A DRY AIR INTRUSION. BEHIND THE FRONT...THE ATMOSPHERIC
PROFILE SATURATES AND PRECIPITATION WILL BEGIN TO REACH THE
GROUND. IT SEEMS THERE WILL BE A STRONG BAND OF SNOW THAT WILL
DEVELOP BEHIND THE FRONT AND TRANSITION ACROSS THE AREA FAIRLY
QUICKLY. UNDER THE BAND...SNOWFALL RATES AND WINDS WILL BRING
PROBLEMS WITH BLOWING SNOW AND DRIFTING. VISIBILITIES WILL BE NEAR
ZERO AT TIMES. DUE TO THE QUICK MOVEMENT OF THE BAND...SNOWFALL
AMOUNTS ARE NOT EXPECTED TO BE NEARLY AS HIGH AS RECENT BANDED
SNOWFALL EVENTS. AT THIS POINT...ONE TO THREE INCHES OF SNOW IS
EXPECTED WITH THE POTENTIAL TO SEE CLOSER TO 4 INCHES OVER
SOUTHWEST NEBRASKA. VERY COMPLICATED SCENARIO AS THE WINDS MAY
APPROACH HIGH WIND WARNING CRITERIA BUT BLIZZARD CONDITIONS MAY
NOT BE MET FOR THE FULL THREE HOUR REQUIREMENT. THEREFORE...THE
ADVISORY WAS ISSUED AS WINTER STORM CRITERIA WOULD NOT BE MET AS
WELL. HIGHLIGHT CHANGES MAY BE NEEDED CLOSER TO THE EVENT
DEPENDING ON DURATION OF HEAVIER SNOW AND THUS LOWER VISIBILITIES
OR THE STRENGTH OF THE WINDS.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 145 PM MST TUE FEB 18 2014
LATEST WV IMAGERY AND RAP H5 ANALYSIS INDICATE SHORTWAVE TROUGH OVER
EASTERN NEBRASKA/KANSAS WITH SHORTWAVE RIDGE OVER THE GREAT BASIN
AND NORTHERN ROCKIES. A COLD FRONT (WHICH SHOWS UP BETTER WITH
VERTICAL THICKNESS FIELD) IS MOVING SOUTH TO THE KS/NE BORDER WITH A
PREFRONTAL SURFACE TROUGH AXIS NOW ACROSS CENTRAL KANSAS.
THIS AFTERNOON...STRONG PRESSURE GRADIENT HAS LED TO DEVELOPMENT OF
WIND GUSTS 45-60 MPH ACROSS THE NORTHERN HALF OF THE CWA...WITH
WINDS JUST STARTING TO COME UP ACROSS THE EAST AND SOUTH OVER THE
LAST HOUR. STRONGEST GUSTS WERE ASSOCIATED WITH INITIAL SURGE AS
SURFACE TROUGH SHIFTED SOUTH AND 3HR PRESSURE RISES BEHIND COLD
FRONT PEAKED AROUND 4MB. WINDS HAVE STABILIZED WITHIN ADVISORY
CRITERIA AFTER THIS INITIAL SURGE...SO DECISION WAS MADE TO HOLD
ONTO ADVISORY. RED FLAG CONDITIONS ARE BEING MET AT MOST OF WARNED
AREA...THOUGH INCREASING TD VALUES FROM THE NORTH ARE KEEPING RH
VALUES CLOSER TO 30 PERCENT ACROSS THE NORTHERN PART OF THE RFW. WE
MAY NOT MEET THE HIGH END THRESHOLD FOR RED FLAG CONDITIONS...
HOWEVER WITH THE MAGNITUDE OF WIND...I SEE NO REASON TO MAKE A CHANGE
TO GOING HEADLINES AT THIS POINT. RFW/NPW WILL CONTINUE THROUGH 01Z.
TONIGHT-WEDNESDAY...WINDS WILL QUICKLY DECREASE WITH LOSS OF DAYTIME
MIXING AND WEAKENING GRADIENT THIS EVENING. HIGH CLOUD COVER MOVING
IN FROM THE WEST LATER THIS EVENING MAY LIMIT RADIATIONAL COOLING
TONIGHT AND DIURNAL HEATING WEDNESDAY. LEE TROUGH ALSO REDEVELOPS
AFTER MIDNIGHT TONIGHT IN RESPONSE TO STRONG TROUGH MOVING OUT OF
THE PACIFIC NORTHWEST...WITH RESULTING SOUTHERLY FLOW SUPPORTING WAA
ACROSS THE WEST. I BUMPED LOW TEMPS UP TONIGHT AND HIGH TEMPS UP WED
FOR NOW...AND COULD SEE BOTH PERIODS BEING A LITTLE WARMER/COOLER
THAN ADVERTISED DEPENDING ON CLOUDS. OTHER IMMEDIATE CONCERN WILL BE
BREEZY-WINDY CONDITIONS WEDNESDAY AS SOUTHERLY GRADIENT INCREASE
AHEAD OF APPROACHING UPPER LEVEL SYSTEM. MODEL TEMPERATURE PROFILES
INDICATE MIXING HEIGHTS AROUND 750MB-800MB WHICH KEEPS WINDS JUST
UNDER (OR NEAR) ADVISORY CRITERIA...AND WITH CLOUD COVER POSSIBLY
LIMITING MIXING OVERALL...I DECIDED AGAINST ISSUANCE OF ANOTHER
ADVISORY WED AFTERNOON. UPPER LEVEL SYSTEM DOES APPROACH CENTRAL
ROCKIES WED AFTERNOON AND SURFACE TROUGH WILL SHIFT EAST ALLOWING
WINDS TO DECREASE LATER IN THE AFTERNOON. WHILE FORCING DOES BEGIN
TO INCREASE OVER THE ROCKIES...IT CURRENTLY LOOKS LIKE PRECIP
CHANCES SHOULD HOLD OFF UNTIL WED EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 224 PM MST TUE FEB 18 2014
FORECAST CONCERNS WILL BE WINDS THROUGH FRIDAY AND PRECIPITATION
CHANCE/PHASE WEDNESDAY NIGHT. SATELLITE SHOWING A PROGRESSIVE AND
ACTIVE WAVE TRAIN FROM THE PACIFIC INTO THE ATLANTIC. NEXT SHORTWAVE
OF INTEREST IS ENTERING THE PACIFIC NORTHWEST. VERY DRY AIR MASS
ALOFT AT THIS TIME.
AT JET LEVEL...MODELS STARTED OUT FINE. AT MID LEVELS...LOOKS TO BE
NO SERIOUS INITIALIZATION PROBLEMS WITH THE MODELS MAYBE A LITTLE
TOO FAR SOUTH AND EAST. AT THIS TIME...THE ECMWF...CANADIAN...UKMET
AND GFS APPEAR TO BE DOING SLIGHTLY BETTER. ECMWF AND SREF WERE
DOING WELL INITIALLY WITH THE SURFACE WIND AND PRESSURE PATTERN.
THE CANADIAN...UKMET AND GFS WERE DOING THE BEST WITH THE LOW LEVEL
THERMAL FIELD.
WEDNESDAY NIGHT...AREA TRANSITIONS FROM WARM...DRY AND WINDY TO
COLD...WET AND WINDY. THERE ARE SOME DIFFERENCES IN THE JET AND
TROUGH POSITION. SOME MODELS HAVE THE LEFT FRONT QUADRANT WELL
SOUTH...AFFECTING THE SOUTHERN HALF OF THE AREA OR STILL TO THE WEST
OF THE AREA. BY THE MIDDLE OF THE NIGHT...THE JET AXIS HAS MOVED
ACROSS WITH THE MAIN AFFECT FROM THE LEFT FRONT QUADRANT ACROSS THE
SOUTHERN HALF OF THE AREA THROUGH THE EVENING. VERY STRONG
FRONTOGENETICAL FORCING MOVES ACROSS THE AREA FROM EARLY IN THE
EVENING TO LATE IN THE NIGHT. THETA-E LAPSE RATES NEAR ZERO OR
SLIGHTLY BELOW ZERO ARE NOT ONLY AT MID LEVELS FOR THE ENTIRE NIGHT
BUT FOR A BRIEF PERIOD ARE AT LOW LEVELS.
SO THE LIKELIHOOD OF PRECIPITATION IS PRETTY HIGH. THE QUESTION
BECOMES WHEN WILL THE PHASE CHANGE FROM RAIN TO SNOW AND HOW MUCH
SNOW WILL OCCUR AFTER THIS HAPPENS. MODEL SOUNDINGS AND WET BULB
PROGS WOULD INDICATE THE NORTHWEST HALF WILL TRANSITION FROM A
RAIN/SNOW MIX EARLY TO ALL SNOW BY 06Z. THE SOUTHEAST HALF WILL
HAVE RAIN UNTIL NEAR 05-06Z BEFORE RAPIDLY CHANGING TO SNOW.
PRECIPITABLE WATER NEARS A HALF INCH OVER THE EASTERN HALF TO TWO
THIRDS OF THE AREA. LIKE THE REPRESENTATION OF QPF THAT WPC HAS AND
USED AS A THE BUILDING BLOCK FOR THE QPF AND SNOWFALL. WPC SLR
GUIDANCE WOULD INDICATE A NEAR 13 TO 1 RATIO IS NEAR NORMAL AND THAT
SEEMS REASONABLE. SO CONSIDERING THE FORCING AND INSTABILITY...THE
SNOW COULD BE RATHER INTENSE AT TIMES DURING THE NIGHT.
SO WITH USING THE WPC QPF AND CUTTING OFF A LITTLE BIT DUE TO THE
EXPECTED PHASE TO BE RAIN...CAME UP WITH 1 TO 4 INCHES WITH THE
LOWEST IN THE FAR SOUTH AND THE MOST FROM YUMA COUNTY TO THE COUNTIES
ALONG THE KANSAS AND NEBRASKA BORDER.
ALL INDICATIONS ARE THAT VERY WINDY CONDITIONS WILL BE A CERTAINTY.
EXTREMELY TIGHT PRESSURE GRADIENT AND 3 HOUR PRESSURE RISES OF NEAR
10 MB WILL PRODUCE VERY WINDY CONDITIONS. AND THAT IS NOT EVEN
CONSIDERING THE POSSIBILITY OF MIXING DOWN EVEN STRONGER WINDS.
THOUGHT LONG AND HARD ABOUT HOW TO HANDLE THIS SCENARIO. WINDS
SHOULD BE IN THE HIGH WIND ADVISORY TO LOW HIGH WIND WARNING RANGE.
SO DESPITE THE AMOUNT OF SNOW EXPECTED...SIGNIFICANT BLOWING OF THAT
SNOW IS EXPECTED. DUE TO HOW FAST THE SNOW MOVES ACROSS THE AREA...3
HOURS OF BLIZZARD CONDITIONS ARE NOT EXPECTED TO OCCUR WHICH WOULD
MEAN A BLIZZARD WARNING. AFTER PLENTY OF DISCUSSION WE HAVE DECIDED
TO ISSUE A WINTER WEATHER ADVISORY AND EMPHASIZE THAT NEAR BLIZZARD
OR BLIZZARD CONDITIONS COULD OCCUR FOR A SHORT PERIOD OF TIME WITH
VISIBILITIES OF A HALF MILE TO A MILE EXPECTED FOR MOST OF THE
PERIOD. SNOW SHOULD BE DONE BY THE END OF THE NIGHT PLUS THE WINDS
SHOULD GO DOWN BY THAT TIME. SO THE WINTER WEATHER ADVISORY WILL BE
FOR THE WHOLE NIGHT FOR THE NORTHWEST HALF AND FOR THE SOUTHEAST HALF
FOR THE LAST HALF OF THE NIGHT ENDING AT 6 TO 7 AM LOCAL TIME.
THURSDAY/THURSDAY NIGHT...SOME DIFFERENCES IN THE SPEED OF INCOMING
NORTH TO SOUTH JET...BUT IT LOOKS TO BE WEST OF THE AREA THROUGH
THE DAY. THAT SEGMENT FLATTENS OUT WITH A WEST TO EAST JET AXIS AND
RIGHT REAR QUADRANT OVER THE NORTHERN HALF OF THE AREA BY THE END
OF THE NIGHT. AT THIS TIME ALL THE MOISTURE IS ALOFT SO THIS WILL
ONLY CAUSE CLOUDS.
THE BIG PROBLEM WILL BE THAT WINDS WILL COME UP AGAIN DURING THE
DAY BEHIND THE EXITING SHORTWAVE TROUGH. QUESTIONS WILL BE HOW
MUCH MIXING WILL OCCUR...ESPECIALLY IN THE NORTH...DUE TO SNOW ON THE
GROUND. LOOK TO STAY MIXED THROUGH THE NIGHT. DURING THE DAY THERE IS
GOOD UNIDIRECTIONAL FLOW WITH DECENT DOWNWARD MOTION. MODELS SHOW
GOOD LAPSE RATES TO AT LEAST 700 MB. SO IT WOULD APPEAR THINGS WILL
MIX WELL. MODEL SOUNDINGS WOULD INDICATE AT LEAST WIND ADVISORY...
POSSIBLY HIGH END...AND POSSIBLY REACHING HIGH WIND WARNING
CRITERIA. SO WILL KEEP WINDY TO VERY WINDY CONDITIONS AND THIS WILL
NEED TO BE ADDRESSED AFTER THE WINTER WEATHER ADVISORY IS DONE.
DEPENDING ON THE AMOUNT OF SNOW AND HOW MUCH IF ANY THE SNOW CRUSTS
OVER...THERE COULD BE SOME MORE BLOWING SNOW DESPITE NO PRECIPITATION
OCCURRING. SO DID PUT IN PATCHY BLOWING SNOW AT THIS TIME. WILL PUT
MAXES IN NEAR TO SLIGHTLY BELOW GUIDANCE.
FRIDAY...ABOVE JET MOVES SOUTH ACROSS THE AREA AT VARIOUS SPEEDS AND
WILL BE NEAR OR JUST SOUTH OF THE AREA BY THE END OF THE DAY. THIS
JUST LOOKS TO PRODUCE SOME CLOUDS. MODELS SHOWING WIND SPEEDS
INCREASING INTO THE WINDY CATEGORY AGAIN. LAPSE RATES LOOK TO STILL
STAY GOOD BUT THE FLOW IS NOT AS UNIDIRECTIONAL AND THE DOWNWARD
MOTION IS NOT AS GREAT. BUFKIT SOUNDINGS ARE INDICATING THE MIXING
DOWN OF A LEAST WIND ADVISORY CRITERIA WINDS AGAIN. WILL DEFINITELY
TRY AND HAVE WINDY WORDING IN THERE AT THIS TIME. TEMPERATURES
SHOULD BE WARMER BUT NOT SURE DEPENDING ON THE AMOUNT OF SNOW ON THE
GROUND.
FRIDAY NIGHT THROUGH TUESDAY...AT END OF THE SHORT TERM INTO THE
BEGINNING OF THIS PERIOD...THE PATTERN TRANSITIONS FROM A
PROGRESSIVE FLOW TO A HIGH AMPLITUDE RIDGE ALONG THE WEST COAST OF
NORTH AMERICA AND HUDSON BAY LOW BECOMING ESTABLISHED ONCE AGAIN BY
THE END OF THE PERIOD. PRECIPITATION IS VERY HARD TO PIN DOWN. WILL
HAVE VERY FAST WEST TO NORTHWEST FLOW WITH EMBEDDED SHORTWAVE TROUGHS
AND JET ENERGY. SIGNIFICANT MOISTURE WILL BE HARD TO COME BY IN THIS
SCENARIO. HOWEVER CANNOT RULE OUT SOME BRIEF AND SPOTTY PRECIPITATION
CHANCES. SO LEFT THE CRH_INIT POPS ALONE WHICH WERE NO HIGHER THAN
SLIGHT CHANCE WHICH SEEMS REASONABLE.
COLDER TEMPERATURES LOOK TO BE COMING BACK. BY LATE IN THE WEEKEND
A SHALLOW COLD AIR MASS WILL BE IN PLACE AS A SURFACE RIDGE BECOMES
ESTABLISHED OVER THE NORTH CENTRAL PORTION OF THE COUNTRY. SO
FOLLOWED OTHER OFFICES AND MADE SLIGHT ADJUSTMENTS DOWN IN
TEMPERATURES...ESPECIALLY THE MAXES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 412 PM MST TUE FEB 18 2014
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD. SURFACE HIGH
PRESSURE WILL SETTLE IN OVER BOTH TERMINALS TONIGHT...ALLOWING
WINDS TO BECOME LIGHT AND VARIABLE. AS THE SURFACE HIGH MOVES
EAST...SOUTHERLY SURFACE WINDS WILL SET UP OVER THE TERMINALS WITH
WINDS INCREASING TO 20 TO 25 KTS SUSTAINED AND GUSTS UP TO 35 KTS
IN THE LATE MORNING INTO THE AFTERNOON. A STRONG COLD FRONT WILL
MOVE INTO THE TERMINALS AFTER THIS TAF PERIOD...SO WILL LEAVE THE
WIND SHIFT AND LOWERING CEILINGS FOR LATER TAF ISSUANCES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ WEDNESDAY TO 6
AM MST /7 AM CST/ THURSDAY FOR KSZ001-002-013-027.
WINTER WEATHER ADVISORY FROM 10 PM MST /11 PM CST/ WEDNESDAY TO
6 AM MST /7 AM CST/ THURSDAY FOR KSZ003-004-014>016-028-029-
041-042.
CO...WINTER WEATHER ADVISORY FROM 7 PM WEDNESDAY TO 6 AM MST THURSDAY
FOR COZ090>092.
NE...WINTER WEATHER ADVISORY FROM 7 PM MST /8 PM CST/ WEDNESDAY TO 6
AM MST /7 AM CST/ THURSDAY FOR NEZ079>081.
&&
$$
UPDATE...RRH
SHORT TERM...DJR
LONG TERM...BULLER
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS GRAY ME
1108 PM EST TUE FEB 18 2014
.SYNOPSIS...
LOW PRESSURE DEEPENS OFF THE NEW ENGLAND COAST AND WILL EXIT INTO
THE CANADIAN MARITIMES OVERNIGHT. A COLD FRONT WILL SWING IN FROM THE WEST
ON WEDNESDAY AND LOW PRESSURE WILL DEVELOP ON THE FRONT AS IT
PUSHES INTO THE GULF OF MAINE WEDNESDAY EVENING. LOW PRESSURE WILL
QUICKLY SHIFT EAST INTO THE MARITIMES WEDNESDAY NIGHT. HIGH
PRESSURE BUILD SIN FROM THE WEST ON THURSDAY. A WARM FRONT WILL
LIFT NORTH INTO THE REGION THURSDAY NIGHT AND IS QUICKLY FOLLOWED
BY A COLD FRONT FRIDAY. HIGH PRESSURE BUILDS SOUTH OF NEW ENGLAND
FRIDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
1105 PM...SNOW CONTINUES TO DIMINISH ACROSS THE AREA AND HEADLINES
HAVE BEEN DROPPED FOR AREAS JUST NORTH AND EAST OF PORTLAND.
950 PM...A 1008 MILLIBAR LOW WAS JUST WEST OF THE 44005 BUOY IN
THE GULF OF MAINE AT 02Z. SNOW CONTINUES TO WIND DOWN FROM
SOUTHWEST TO NORTHEAST AND WINTER HEADLINES HAVE BEEN DROPPED FOR
SOUTHWEST MAINE WITH THIS ESTF UPDATE.
PREV DISC...
650 PM...SOME SLIGHT ADJUSTMENTS TO SNOW AMOUNTS FOR THE FINAL
UPDATE BEFORE WE BEGIN TAKING WINTER WEATHER HEADLINES DOWN.
EXPECT WE`LL BE DROPPING HEADLINES WITHIN THE NEXT FEW HOURS AS
THE BACK EDGE OF THE HEAVY SNOW BANDS RACE NORTHEAST OUT OF THE
FORECAST AREA.
458 PM...BANDS OF HEAVY SNOW ARE RACING NORTH AND EAST ACROSS THE
FORECAST AREA. SNOWFALL RATES HAVE APPROACHED 3 INCHES PER HOUR
IN THE HEAVIEST BANDS. I`VE ADJUSTED AMOUNTS UP A BIT FOR THIS
UPDATE AND EXPANDED THE WARNING TO INCLUDE SEACOAST NEW HAMPSHIRE.
PREV DISC...
LOW PRES IS RAPIDLY DEVELOPING AS EXPECTED OVER SRN NEW ENGLAND
COAST ATTM. BASED ON RADAR AND SFC OBSERVATIONS...IT WOULD SEEM AS
IF LOW PRES WILL TRACK JUST N OF KPYM AND INTO THE GULF OF ME.
HEAVY SNFL HAS WORKED INTO SRN NH AND ADJACENT SWRN ME...WITH
RATES APPROACHING 1 TO 3 INCHES PER HOUR. SNFL TOTALS ARE ALREADY
PUSHING 4 TO 6 OR MORE ACROSS PARTS OF INTERIOR ROCKINGHAM COUNTY.
BASED ON MODEL PROGS AND REPORTS...FEEL THAT THIS IS THE AREA NOW
IN LINE FOR HIGHEST AMOUNTS IN THE CWFA. HAVE INCREASED QPF AND
SNFL FORECAST FOR THIS AREA. FOR THE REST OF THE AREA USED A BLEND
OF THE ECMWF...NAM12...RAP...AND NERFC QPF. THIS SHIFTED THE
HEAVIEST SN A LITTLE EWD FROM PREVIOUS FORECAST. SNFL AMOUNTS
STILL MATCHED HEADLINES WELL...SO THEY WILL REMAIN AS IS.
ELY WINDS HAVE ALSO WARMED THE IMMEDIATE COAST AOA FREEZING.
DESPITE THE WARM TEMPS...DEW POINT DEPRESSIONS WILL ALLOW WET BULB
COOLING TO KEEP PCPN MOSTLY SN. HOWEVER...IT MAY BE WETTER IN
NATURE AND CLING TO POWER LINES/TREES LEADING TO SCT POWER
OUTAGES. ELY WINDS ARE ALSO DOWNSLOPING ON THE N SIDE OF THE
WHITES...DRYING OUT THE COLUMN. SN WILL LIKELY STRUGGLE TO REACH
THE GROUND AT TIMES IN THE FAR N.
AS FOR SRN NH INTO SWRN ME...HEAVY SNFL REMAINS IN THE FORECAST
INTO THE EVENING. RAP CONTINUES TO SHOW FORECAST SOUNDINGS FROM
KCON TO NEAR KPWM APPROACHING A MAUL...MOIST ABSOLUTELY UNSTABLE
LAYER. MODEL GUIDANCE HAS AN AREA OF 6 TO 7 DEG/KM LAPSE RATES
ALOFT WORKING INTO THE REGION THRU THE EVENING. THIS KIND OF
INSTABILITY WOULD BE FAVORABLE FOR CONVECTION IN THE WARM
SEASON...LET ALONE FEBRUARY. THERE HAVE BEEN NO RECENT REPORTS OF
LIGHTNING...BUT WOULD NOT BE SURPRISED TO SEE A FEW IN THE NEXT
COUPLE OF HOURS. CONSIDERING THE SNFL OCCURRING ATTM IN SERN
NH...SEE NO REASON WHY THIS TREND WON/T THEN CONTINUE FOR THE NEXT
SEVERAL HOURS INTO SWRN ME. THIS IS ALL ONGOING AS MID LEVEL LOW
CENTER QUICKLY SPIN UP...MAXIMIZING DYNAMICS. AS THESE MATURE THIS
EVENING...SN WILL GRADUALLY TAPER TO MORE MODEST RATES. AS FORCING
SHIFTS EWD...SN WILL RAPIDLY END FROM S TO N AROUND MIDNIGHT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS SOON AS TONIGHT`S STORM LIFTS INTO THE CANADIAN MARITIMES...
ANOTHER SHORT WAVE QUICKLY FOLLOWS ON ITS HEELS...FOLLOWING A
SIMILAR PATH. SURFACE LOW PRESSURE DEEPENS OVER THE GULF OF MAINE
WEDNESDAY AFTERNOON INTO THURSDAY MORNING. THIS STORM IS FORMING A
LITTLE TOO FAR OFFSHORE TO ACCOUNT FOR MORE THAN 1-3 INCHES AS IT
MOVES QUICKLY BY.
TEMPERATURES WILL BE IN THE MID 30S TO MID 40S WEDNESDAY THROUGH
FRIDAY AS WARM AIR ADVECTION IS REINFORCED EVERY 18 HRS OR SO.
THE TIMING OF THESE WAVES AS WELL AS NEAR ZONAL FLOW ALOFT WILL
KEEP ANY COLD AIR FROM TAKING HOLD FOR MOST OF THE WEEK.
HOWEVER...SOME COLDER AIR DOES MANAGE TO SNEAK IN BEHIND A COLD
FRONT ON FRIDAY. THIS WILL BE PRECEDED BY A WARM FRONT FRIDAY
MORNING. TEMPERATURES AT THE ONSET OF THIS PRECIPITATION EVENT
SUPPORTS A LARGE SWATH OF FREEZING RAIN AND POSSIBLY SOME SLEET
FRIDAY MORNING AS WARMER AIR OVERRIDES FREEZING TEMPERATURES
NEAR THE SURFACE. AT THIS TIME IT LOOKS TO BE A COUPLE TENTHS OF
AN INCH OF ICE ACCUMULATION...BUT IT WILL OCCUR DURING MORNING RUSH
HOUR. AS WARMER AIR IS DRAGGED DOWN WE WILL TRANSITION TO A MOSTLY
RAIN EVENT DURING THE DAY WITH A LITTLE WRAP AROUND SNOW ONCE THE
COLD FRONT MOVES THROUGH. THIS SYSTEM HAS MUCH MORE MOISTURE TO
WORK WITH THAN WE HAVE HAD LATELY...AND THIS WILL RESULT IN PLENTY
OF SNOW MELT AND POSSIBLY ICE JAM ISSUES.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM.../THROUGH WEDNESDAY MORNING/...WIDESPREAD IFR AND LIFR
EXPECTED S OF THE FOOTHILLS THRU THIS EVENING. N OF THE MTNS IFR
CONDITIONS WILL BE MORE VARIABLE AS DOWNSLOPING DRIES OUT THE AIR
MASS. CONDITIONS WILL QUICKLY IMPROVE FROM S TO N AFTER MIDNIGHT.
LONG TERM...ADDITIONAL SNOW IS FORECAST FOR WEDNESDAY AFTERNOON
INTO THURSDAY MORNING...AND WILL PRODUCE LIFR CEILINGS AND
VISIBILITIES. WIDESPREAD MIXED PRECIPITATION INCLUDING FREEZING
RAIN AND RAIN WILL CREATE POOR FLYING CONDITIONS THURSDAY NIGHT
INTO FRIDAY.
&&
.MARINE...
SHORT TERM...GALES REMAIN UP FOR THE OUTER WATERS...WITH SCA
CONDITIONS EXPECTED IN THE BAYS. WINDS AND SEAS GRADUALLY SUBSIDE
INTO WED MORNING.
LONG TERM...SMALL CRAFT ADVISORIES MAY BE NEEDED AT TIMES THROUGH
FRIDAY WITH GUSTS AROUND 25-30 KTS AND WAVES IN THE 4-6 FT
RANGE...MAINLY OUTSIDE THE BAYS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 4 AM EST WEDNESDAY FOR MEZ014-
021-022-027-028.
WINTER STORM WARNING UNTIL 4 AM EST WEDNESDAY FOR MEZ026.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST WEDNESDAY FOR ANZ151-153.
GALE WARNING UNTIL 4 AM EST WEDNESDAY FOR ANZ150-152-154.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
355 AM EST WED FEB 19 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY. HIGH PRESSURE WILL RETURN
TONIGHT AND THEN DRIFT OFFSHORE THURSDAY. A STRONGER COLD FRONT
MOVES THROUGH FRIDAY. HIGH PRESSURE WILL THEN RETURN OVER THE
WEEKEND. LOW PRESSURE APPROACHES THE REGION TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOPRES OVER LK SUPERIOR ELY THIS MRNG...W/ AN ATTENDENT CDFNT FM ORD
DOWN THE MID-LWR MS RVR VLY. SFC ANALY ALSO SUGGESTING THERE MAY BE
A HINT OF A WMFNT ACRS CWFA...ROUGHLY DOWN THE PTMC. THE CORE OF THE
COLD AIR /TEMPS IN THE TEENS/ IS OVER NEW ENGLAND...BUT SUBFRZG AIR
CAN BE FOUND IN THE PTMC HIGHLANDS AND ACRS NRN MD. MEANWHILE...
STRONG ISENT LIFT IS PRODUCING AN AREA OF PCPN IN THE OH/TN VLYS AND
ACRS THE MTNS OF NC. THAT LIFT...AND THE ASSOC PCPN /WHICH IS ALL
RA/...PROGGED TO ARRIVE IN THE CWFA BTWN 12-14 UTC. HV INCRSD POPS
AND DELAYED TIMING BASED ON LTST GDNC. QSTN REMAINS WHAT WL THE SFC
TEMPS BE WHEN RAIN ARRIVES.
MDL SNDGS...SPCLY FM THE NAM...SUGGEST THAT A STRONG WARM NOSE WL
RESIDE ARND H9 BUT SFC TEMPS WL STILL BE BLO FRZG. GFS IS WARMER AT
THE SFC AND HAS A LESS PRONOUNCED WARM AIR INTRUSION. RAP BTWN THE
TWO THERMALLY...BUT HAS A LATE PCPN ONSET. SINCE NRN MD HAS A SOLID
SNOWPACK...THINK THE NAM IS ONTO SOMETHING...AND PREFER ITS SOLN FOR
THE MRNG. WE HV A FZRA ADVY IN PLACE FOR NRN MD...AND WL BE KEEPING
THAT GOING. ONLY CONCERN IS WHETHER THE NRN PORTION OF THE ERN WVA
PANHNDL /MINERAL TO JEFFERSON CNTYS/ SHUD BE INCLUDED. GRIDS FM 00Z
NAM/GMOS BLENDED IN FCST DATABASE. MUST ADMIT ITS A CLOSE CALL...
BUT SIGNS POINT TO JUST SQUEAKING IT OUT. WL MONITOR CLOSELY...BUT
HV OPTED TO NOT EXPAND CVRG ATTM.
CDFNT CROSSES CWFA DURING THE AFTN HRS...W/ STRONG CAA /AND DP
MIXING/ IN ITS WAKE. AM XPCTG A BRZY AFTN CONSIDERING WNDS AVBL BTWN
H8 AND SFC. WENT ON THE RESERVED SIDE IN DATABASE...KEEPING GUSTS
20-30 MPH. IF FULL MIXING TRANSPIRES...IT MAY BE MORE THAN THAT.
PAST FEW DAYS...TEMPS HV BEEN WARMER THAN PROGGED. SINCE CAA WL BE
ARRIVING LT IN THE DAY...AND WL BE ACCMPNYD BY COMPRESSIONAL
WARMING...WENT ON THE WARM SIDE OF GDNC FOR MAXT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
RDGG /SFC-H7/ WL BUILD ATOP CWFA TNGT...AND PROGRESS TO THE DELMARVA
THU MRNG. AM XPCTG MOCLR SKIES/DIMINISHING WNDS TNGT...AND MIN-T
FLLW SUIT.
BY THU...WL BE BACK IN RTN FLOW...AND SHUD HV A MID DECK CLDS
OVERSPREADING AREA ONCE AGN. THESE CLDS WL THICKEN THRUT THE DAY AS
ISENT LIFT STRENGTHENS. WHILE SOME MDL FIELDS SUGGEST THERE MAY BE A
LTL PCPN BY THE END OF THE DAY...POPS REMAIN VERY LOW. HV
ENTERTAINED A SCHC IN THE NWRN CORNER OF CWFA ONLY...WHICH WUD BE
NEARER A DVLPG WMFNT.
A LTL VARIANCE NOTED IN THU MAXT...BUT ALL GDNC WARMER THAN PRVS
FCST. HV RAISED TEMPS ACCRDGLY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THURSDAY EVENING BEGINS WITH A WARM FRONT LOCATED TO THE SOUTH OF
THE AREA...BUT MODELS SHOW A STRENGTHENING LOW LEVEL JET AND
SOUTHERLY BOUNDARY LAYER WINDS LOOK STRONG ENOUGH TO SEND THIS WARM
FRONT NORTHWARD DURING THE NIGHT THURSDAY. SOME RAIN AND FOG ARE
POSSIBLE THURSDAY NIGHT...BUT AS QUICKLY AS THE WARM FRONT LIFTS
TO THE NORTH A COLD FRONT WILL BE APPROACHING FROM THE WEST.
MODELS/ENSEMBLES HAVE TRENDED FASTER...WITH SHOWERS MOVING INTO THE
POTOMAC HIGHLANDS LATE THURSDAY NIGHT AND THEN AFFECTING THE CWA
PRIMARILY FRIDAY MORNING AND EXITING DURING THE AFTERNOON. A FASTER
PASSAGE MAY HELP LIMIT INSTABILITY AND WIDESPREAD SEVERE...HOWEVER
STRONG WINDS IN THE LOW LEVELS MAY BE TRANSPORTED DOWN TO THE
SURFACE EVEN IN ABSENCE OF THUNDERSTORMS /I.E. WITH ONLY SHOWERS/
AND THUS LOCALLY DAMAGING WINDS WILL BE POSSIBLE IN A HIGH SHEAR
BUT LOW/LITTLE CAPE ENVIRONMENT.
MAXIMA MAY WIND UP OCCURRING DURING FRIDAY MORNING...WITH
TEMPERATURES DROPPING BEHIND THE FRONT LATER FRIDAY. ATTEMPTED TO
REFLECT SOME TIMING DETAILS IN THE GRIDS...INCLUDING FOR
MINIMA/MAXIMA THURSDAY NIGHT/FRIDAY.
DRIER AIR MOVES IN FOR FRIDAY NIGHT AND SATURDAY AND THUS THE RETURN
OF SUNSHINE IS EXPECTED FOR SATURDAY. WITH GOOD INSOLATION AND A
SOUTHWEST FLOW...SATURDAY LOOKS LIKE A MILD DAY WITH MAXIMA 10 PLUS
DEGREES ABOVE AVERAGE.
A REINFORCING COLD FRONT IS EXPECTED ON SUNDAY. ASIDE FROM SOME
CLOUDS AND SILENT POPS OVER THE HIGHLANDS...FRONT LIKELY PASSES
THROUGH RATHER QUIETLY. HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL HOWEVER HAVE SOME COOLER AIR WITH IT /NEAR AVERAGE FOR THIS
TIME OF THE YEAR/ WHICH WILL TAKE HOLD OF THE MID-ATLANTIC EARLY
NEXT WEEK.
NEXT STORM SYSTEM APPROACHES ON TUESDAY...AND HAVE BUMPED POPS UP TO
CHANCE. UNCERTAINTY IN P-TYPE EXISTS AND HAVE GENERIC RAIN OR SNOW
WORDING.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS ATTM..BUT XPCT PCPN TO OVERSPREAD TERMINALS DURING THE
MRNG PUSH. FLGT RESTRICTIONS MAY DVLP...BUT DO NOT XPCT MUCH WORSE
THAN MVFR. TEMPS SHUD BE WARM ENUF BY THE TIME PCPN ARRIVES /11-13
UTC/ FOR NO PTYPE CONCERNS--XPCT JUST RAIN. THE CLOSEST CALL WL BE
AT MRB AND MTN...WHERE THERE IS A CHC AT BRIEF FZRA AT ONSET. PCPN
DRIVEN BY A STRONG LLJ...AND HV LLWS CONDS IN TAFS THRU THE MRNG /UP
TO 45 KT/.
PCPN SHUD BE GONE BY MIDDAY...AND A WSHFT DURING THE AFTN WL
ACCOMPANY A CDFNT. WLY WNDS G25KT LKLY POST FROPA...BUT GRADIENT
/AND WNDS/ WL RELAX AFDK.
HIPRES OVNGT WL NO CIGS AND LTL WND. SLY FLOW WL RESUME THU MRNG...
INCRSG AGN DURING THE AFTN. CIGS WL DVLP AND LWR...BUT SHUD REMAIN
DRY THRU THE DAY W/ VFR CONDS PREVAILING.
THURSDAY NIGHT...FLIGHT RESTRICTIONS MAY DEVELOP IN SOME RAIN/FOG.
SREFS SUGGESTS AT LEAST IFR...WITH SUPPORT FROM MAV/MET. STRONG LLJ
WILL ALSO BRING THE LIKELIHOOD OF LOW LEVEL WIND SHEAR.
FRIDAY...COLD FRONT MOVES ACROSS THE AREA WITH SHOWERS. SHOWERS
COULD TRANSPORT STRONG GUSTY WINDS TO THE SURFACE. FROPA MAY WIND UP
BEING IN THE MORNING...ALTHOUGH EXACT TIMING IS STILL SOMEWHAT
UNCERTAIN.
SATURDAY INTO EARLY NEXT WEEK...HIGH PRESSURE BUILDS IN FOR NO
SIGNIFICANT WEATHER THROUGH MONDAY. NEXT STORM APPROACHES WITH A
CHANCE OF RAIN OR SNOW TUESDAY.
&&
.MARINE...
WHILE QUIET CONDS PREVAIL ON THE WATERS ATTM SLY WNDS AOB 10 KT/...
WNDS WL INCRS TDA AHD OF CDFNT. A STRONG SLY LLJ WL DVLP THIS MRNG.
WHILE THERE WL BE A STRONG INVSN WHICH WL TRAP MOST OF THE WNDS OFF
THE WATERS SFC...THE MAGNITUDE OF WND AND PRESENCE OF RA MAY MIX A
LTL DOWN. HV OPTED TO KEEP SCA GOING FOR MID BAY AND LWR PTMC...
ALTHO ITS NOT OF THE HIEST CONFIDENCE.
POST FROPA THERE IS A GOOD MIXED PROFILE FOR A FEW HRS. SCA IN
EFFECT FOR ALL WATERS TAFTN. THE CFP MAY BE A LTL LATER THAN PRVSLY
PROGGED...AND HV XTNDD SCA FOR THE WATERS INTO ELY EVNG PTMC AND MID
EVNG LWR PTMC/BAY.
GRADIENT WL RELAX OVNGT UNDER HIPRES. SLY FLOW WL RESUME THU. WHILE
GRADIENT INCREASES ONCE AGN...THINK THAT MIXING WL HOLD OFF...AND HV
KEPT WNDS UNDER SCA THRESHOLDS.
STRONG SOUTHERLY JET WILL BE IN PLACE THURSDAY NIGHT. A FRACTION OF
WIND ALOFT WILL LIKELY BE ABLE TO MIX DOWN OVERNIGHT FOR SCA
CONDITIONS. WINDS INCREASE FURTHER FRIDAY MORNING AHEAD OF A COLD
FRONT...POSSIBLY NEAR GALES. SHOWERS ASSOCIATED WITH THE FRONT MAY
ALSO BRING DOWN STRONG GUSTY WINDS. FRONT SHOULD MOVE EAST OF THE
WATERS FRIDAY AFTERNOON. HIGH PRESSURE BUILDS IN OVER THE WEEKEND.
&&
.HYDROLOGY...
WILL BE WATCHING SNOWMELT THIS WEEK AS THE WARMUP ENSUES. SNOW WATER
EQUIVALENT VALUES RANGE FROM LESS THAN AN INCH ALONG AND EAST OF
INTERSTATE 95 TO MORE THAN TWO INCHES WEST OF THE BLUE RIDGE AND
ALONG THE MASON DIXON LINE. OBSERVED SNOW WATER EQUIVALENT IS AROUND
4 INCHES IN THE POTOMAC HIGHLANDS /BUT THE HIGHEST VALUES ARE MAINLY
UPSTREAM OF JENNINGS RANDOLPH AND SAVAGE RIVER LAKES/.
A GRADUAL MELT IS EXPECTED IN THE COMING DAYS...SLIGHTLY MORE
PRONOUNCED THU INTO FRI AS LOWS STAY ABOVE FREEZING THURSDAY NIGHT.
IF MODERATE TO HEAVY PRECIPITATION OCCURRED COINCIDENT WITH THE
MELT...CONCERN WOULD BE HIGH FOR FLOODING. HOWEVER...AT THIS TIME...
RAIN AMOUNTS THROUGH FRIDAY ARE EXPECTED TO BE A HALF INCH OR LESS.
AT THIS TIME THE MOST LIKELY SCENARIO SEEMS TO BE A STEADY
WITHIN-BANK RISE OF STREAMS AND RIVERS LATE THIS WEEK AND INTO THE
WEEKEND. IF RAIN AND/OR SNOWMELT ARE MORE THAN CURRENTLY EXPECTED...
THE FLOOD THREAT WOULD INCREASE ACCORDINGLY FRIDAY AND SATURDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MDZ003>007-501-502.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 11 PM EST THIS
EVENING FOR ANZ530-531-538-539.
SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
ANZ532>534-537-540>543.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 8 PM EST THIS
EVENING FOR ANZ535-536.
&&
$$
SYNOPSIS...BPP
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...BPP
AVIATION...HTS/BPP
MARINE...HTS/BPP
HYDROLOGY...JCE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1241 AM EST WED FEB 19 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 405 PM EST TUE FEB 18 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A LOW AMPLITUDE TROF
MOVING ACROSS THE NCNTRL STATES/UPPER MISSISSIPPI VALLEY. THERE ARE
SEVERAL VORT MAXES WITHIN THE TROF. AHEAD OF ONE SHORTWAVE OVER NRN
ONTARIO INTO MN...RADAR RETURNS HAVE BEEN SHOWING UP IN NE MN AND
NOW ACROSS LAKE SUPERIOR. GIVEN DRY LOW-LEVELS...PCPN HAS NOT BEEN
ABLE TO REACH THE GROUND.
AS AFOREMENTIONED SHORTWAVE MOVES ACROSS THE UPPER LAKES TONIGHT...
NOT OUT OF THE QUESTION THAT PATCHY -SN/FLURRIES OR -FZDZ COULD
DEVELOP OVER THE ERN FCST AREA WHERE SHALLOW LOW-LEVEL MOISTURE HAS
ADVECTED N OFF LAKE MICHIGAN. IF LAYER BTWN THE MID LEVEL MOISTURE
AND SHALLOW MOISTURE OFF THE LAKE DOES NOT MOISTEN SUFFICIENTLY...
THEN -FZDZ WILL BE THE PTYPE IF ANY PCPN DOES OCCUR. ELSEWHERE...
HAVE SOME CONCERN FOR -FZDZ OVER THE KEWEENAW WITH WINDS SHIFTING TO
AN UPSLOPE WESTERLY DIRECTION WITH SFC TROF PASSAGE. THERE IS AN
AXIS OF SLIGHTLY HIGHER DWPTS THAT WILL BE ADVECTED INTO THE HIGHER
TERRAIN...AND THIS COULD LEAD TO POSSIBLE STRATUS/FOG AND EVEN
-FZDZ. HOWEVER...WITH FCST SOUNDINGS SHOWING ONLY A VERY SHALLOW SFC
BASED MOIST LAYER AND SINCE MUCH OF WRN LAKE SUPERIOR IS ICED OVER
TO GREATLY LIMIT ANY ADDITIONAL MOISTENING FROM THE LAKE...-FZDZ
POTENTIAL SEEMS VERY MINIMAL ATTM. OUTSIDE OF THOSE CONCERNS...
TONIGHT WILL BE ONE OF THE WARMER NIGHTS IN QUITE A WHILE UNDER
PACIFIC AIR MASS. EXPECT MIN TEMPS GENERALLY IN THE MID TEENS TO
LOWER 20S.
WED WILL BE A DRY DAY AS MIDLEVEL TROF SHIFTS E OF THE AREA AND
SHORTWAVE RIDGING BUILDS INTO THE WRN LAKES. WHILE THERE MIGHT BE
SOME LOW CLOUDS LINGERING INTO WED MORNING OVER THE NW AND MORE
LIKELY THE NE FCST AREA...EXPECT MOST AREAS TO SEE A GOOD DISPLAY OF
SUNSHINE WED. HIGHER MID TO LATE FEB SUN ANGLE WORKING ON THE LOWER
ALBEDO FORESTED TERRAIN WILL HELP TEMPS RISE WELL INTO THE 30S AND
EVEN INTO THE LWR 40S ACROSS MUCH OF THE FCST AREA. NOT OUT OF THE
QUESTION FOR A FEW LOCATIONS TO REACH THE MID 40S WHERE DOWNSLOPING
OCCURS. WITH W TO WNW WINDS FOR MUCH OF THE DAY...TEMPS WILL BE
COOLEST NEAR LAKE SUPERIOR OVER WRN UPPER MI AND OVER THE NE FCST
AREA. IN THOSE LOCATIONS...TEMPS SHOULD STRUGGLE TO RISE ABOVE
FREEZING NEAR THE LAKE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 505 PM EST TUE FEB 18 2014
WED NIGHT...
HIGH PRES AND CLEAR TO PARTLY CLOUDY SKIES WILL GIVE WAY
TO INCREASING SRLY WINDS AND MID/HIGH CLOUDS AS THE WAA REGIME
STRENGTHENS AHEAD OF THE MID LEVEL TROUGH OVER THE PLAINS AND SFC
TROUGH MOVING INTO THE UPPER MS VALLEY. LOWS ARE ONLY EXPECTED TO
DROP INTO THE LOWER 20S.
THURSDAY INTO FRIDAY...
THE MODELS HAVE COME INTO RELATIVELY GOOD AGREEMENT WITH THE TRACK
OF THE INTENSIFYING LOW PRESSURE SYSTEM MOVING INTO THE WRN GREAT
LAKES AND THE STRENGTH/POSITION OF THE MID LEVEL FEATURES. THE WPC
FAVORED ECMWF/GEM REMAINED A BIT FARTHER WEST WITH THE TRACK
COMPARED TO THE GFS. SINCE THE 12Z NAM WAS ALSO VERY CLOSE TO THE
ECMWF...IT WAS USED FOR MORE OF THE FCST DETAILS. THE LOW IS
EXPECTED TO RAPIDLY DEEPEN AS IT TRACKS NORTH FROM NEAR MKE AT
00Z/FRI TO NEAR MARQUETTE AT 06Z/FRI AND INTO NRN LAKE SUPERIOR AT
12Z/FRI.
THE POTENT MID LEVEL DYNAMICS WITH STRONG 700-300 QVECTOR CONV AND
FGEN COMBINED WITH ABUNDANT MOISTURE INFLOW SHOULD EASILY BE ABLE TO
PRODUCE QPF AMOUNTS AROUND AN INCH...ESPECIALLY OVER THE WEST THIRD
OF THE CWA. WITH AN ELEVATED DGZ AOA 10K FT...SLR ONLY AROUND 12Z/1
ARE EXPECTED LEADING TO SNOWFALL AMOUNTS AOA 10 INCHES OVER THE WEST
AND AROUND 6 INCHES CENTRAL. MIXED PCPN IS ALSO EXPECTED OVER THE
EAST HALF WITH AN 850-700 MB WARM LAYER MOVING LATE THU INTO THU
EVENING. WITH SFC TEMPS NEAR FREEZING...A MIX OF SN/PL/FZRA BEFORE
THE PCPN CHANGES BACK TO SNOW LATE. THERE IS STILL MORE UNCERTAINTY
ABOUT THE SNOW AMOUNTS AND PCPN TYPE TIMING OVER THE EAST HALF GIVEN
LINGERING MODEL DIFFERENCES. AS THE LOW MOVES NORTH OF UPPER MI LATE
THU NIGHT INTO FRI MORNING...STRONG WEST WINDS ARE EXPECTED TO
DEVELOP. NAM BUFKIT MIXED LAYER WINDS IN THE 40-50 KT RANGE OVER THE
KEWEENAW SUGGEST POTENTIAL FOR VERY STRONG SFC WINDS WITH SEVERE
BLOWING AND DRIFTING SNOW. SO...A BLIZZARD WATCH WAS POSTED FOR THE
KEWEENAW. OTHER LOCATIONS ACROSS THE CWA WILL ALSO SEE BLSN BUT WILL
HAVE FEWER IMPACTS WITH A WEST WIND. THE WINDS WILL ONLY GRADUALLY
DIMINISH FRIDAY AFTERNOON INTO EVENING. ALTHOUGH THE STRONG WINDS MAY
BREAK UP SOME OF THE LAKE ICE...THE REMAINING EXTENSIVE ICE COVER
WILL SIGNIFICANTLY REDUCE CHANCE FOR ADDITIONAL LAKE ENHANCED SNOW OR
LES. HOWEVER...THE UPSLOPE TERRAIN ENHANCEMENT COULD STILL BOOST
SNOWFALL AMOUNTS OVER THE HIGHER TERRAIN OF THE NW CWA.
SAT-TUE...
ONLY SMALL CHANCE POPS WERE INCLUDED NEAR LAKE SUPERIOR FOR WNW/W
FLOW AREAS AS TEMPS ARE SUFFICIENTLY COLD FOR LAKE EFFECT RIGHT
THROUGH THE WEEKEND. WITH THE EXTENSIVE ICE ON LAKE SUPERIOR IT WILL
BE BE INTERESTING TO SEE HOW MUCH OPEN WATER DEVELOPS AFTER THE
STRONG WINDS EXPECTED ON FRIDAY. AWAY FROM ANY LAKE EFFECT...THE
RETURNING COLD WILL BE THE MAIN STORY WITH READINGS BOTH SATURDAY AND
SUNDAY IN THE TEENS. THE COLD REGIME LOOKS TO AS THE WRN CONUS RIDGE
REEMERGES AND ARCTIC HIGH PRES BUILDS INTO THE REGION FROM WRN
CANADA. HOWEVER...THE MODELS WERE LESS AGGRESSIVE IN BRINGING THE
VERY COLD AIR COMPARED TO PREVIOUS RUNS. TEMPS WILL REMAIN WELL BELOW
NORMAL WITH HIGHS FROM 10 TO 15 AND LOWS FROM ZERO TO AT LEAST 5
BELOW. WIND CHILLS MON AND TUE MORNING ARE ALSO EXPECTED TO DROP TO
NEAR 20 BELOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1239 AM EST WED FEB 19 2014
KIWD AND KCMX TO CONTINUE WITH VFR CONDITIONS THROUGH THE FORECAST
PACKAGE. LIFR CIGS AND VISIBILITIES IN FREEZING FOG DEVELOPED
EARLIER THIS EVENING AT KSAW AS WINDS BACKED A BIT MORE SOUTHERLY.
KSAW ON THE EDGE OF THE FOG/STRATUS PER SATELLITE IMAGERY...THUS FOG
SHOULD LIFT ONCE WINDS SHIFT WEST AND DOWNSLOPE STRENGTHENS. LATEST
SHORT-TERM MODEL RUNS KEEPING WINDS LIGHTER AND DELAYING WESTERLY
WIND SHIFT THERE...THUS HAVE KEPT FOG/STRATUS IN KSAW TAF THROUGH
10Z. ONCE FOG DOES LIFT...VFR CONDITIONS TO PREVAIL THROUGH THE
FORECAST. LATEST NAM BUFKIT SOUNDINGS FOR KCMX SUGGEST LOW CIGS MAY
IMPACT THAT SITE LATE IN THE FORECAST AS WINDS BECOME EASTERLY AND
THIS IS SOMETHING THAT WILL NEED TO BE MONITORED.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EST TUE FEB 18 2014
WINDS ARE FORECAST TO BE LESS THAN 30 KTS THROUGH WED. POTENTIAL FOR
A VERY STRONG LOW PRESSURE SYSTEM THURSDAY INTO FRIDAY WITH PRESSURE
LOWER THAN 975MB OR 29 INCHES TO LIFT ACROSS LAKE SUPERIOR THURSDAY
NIGHT AND INTO NORTHERN ONTARIO ON FRIDAY. NW GALES LIKELY LATE
THURSDAY NIGHT WITH WESTERLY GALES FRIDAY AND FRIDAY NIGHT. EVEN A
RISK OF STORM FORCE WINDS IF THIS SYSTEM TRENDS SLIGHTLY STRONGER.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ006-007-012>014-085.
WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ002-004-009-010-084.
WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ005-011.
BLIZZARD WATCH FROM THURSDAY EVENING THROUGH FRIDAY EVENING FOR
MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLB
AVIATION...RJT
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
245 AM EST WED FEB 19 2014
.SYNOPSIS...
A STORM SYSTEM MOVING ACROSS LAKE ERIE WILL BRING A WARM UP TO OUR
REGION TODAY AND THURSDAY. A STRONGER STORM WILL MOVE FROM THE
MIDWEST INTO LOWER CANADA THURSDAY NIGHT, BRINGING RAIN AND
ADDITIONAL WARM AIR TO NY AND PA.
&&
.NEAR TERM /THROUGH TODAY/...
STORM SYSTEM AND SHORTWAVE TRACKING ACROSS GREAT LAKES WILL BRING
PRECIPITATION TO OUR REGION THIS MORNING. TEMPERATURES FELL INTO
THE TEENS AND LOWER 20S, BUT HAVE ALREADY BEGUN TO STABILIZE AND
RISE IN SOME SPOTS. AS SOUTHERLY FLOW INCREASES AHEAD OF THE
APPROACHING STORM, TEMPERATURES WILL ACCELERATE UPWARD.
THERE ARE TWO BIG PROBLEMS WITH THE CURRENT FREEZING RAIN
SCENARIO. THE FIRST IS THAT THE ATMOSPHERE REMAINS VERY DRY, AND
THE RADAR IS VERY QUIET BACK INTO WESTERN PA AND EASTERN OHIO.
CONVECTIVE ELEMENTS HAVE FIRED OVER SOUTHERN OHIO, BUT RADAR
TRAJECTORY WOULD SUGGEST THEY WILL PASS WELL SOUTH OF OUR FA.
UPGLIDE SHOULD PRODUCE PRECIP FORMATION THIS MORNING, BUT THE
TIMING WILL LIKELY BE BETWEEN 13Z AND 15Z WHEN TEMPERATURES WILL
BE PUSHING NORTH OF 32F. LATEST RUC AND HRRR HAVE SUGGESTED BIG
REDUCTIONS IN QPF/POPS OVER THE FIRST HALF OF THE DAY, WHEN THE
FREEZING RAIN POTENTIAL EXISTS.
WE MAY NEED TO RECONSIDER THE ADVISORY. AT THIS POINT WE WILL LET
IT RIDE, AND HOPEFULLY HAVE A CLEAR ENOUGH RADAR PICTURE BY 5 AM
OR SO THAT WE CAN LEAVE NEXT SHIFT WITH A CONFIDENT FORECAST.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
A RIDGE REBUILDS TONIGHT INTO THURSDAY, ALLOWING FOR AN OVERNIGHT
COOL DOWN BEFORE TEMPERATURES PUSH INTO THE 40S THURSDAY.
A VIGOROUS CYCLONE WILL ROTATE OUT OF THE MIDWEST INTO LOWER
CANADA THURSDAY NIGHT, DRAGGING A WARM FRONT ACROSS LAKE ERIE. DEW
POINTS WILL ALSO INCREASE, AND THERE IS THE POTENTIAL FOR SOME
OVERNIGHT FOG, WHICH IS AN EFFECTIVE SNOW PACK MELTER.
THE COMBINATION OF RUN OFF AND QPF IS NOT TOO ALARMING IN THIS
CASE, AND I WOULD NOT BE SURPRISED IF A LOT OF THE QPF IS ABSORBED
IN THE STILL THICK SNOW PACK.
THE MAIN RISK APPEARS TO BE FOR ICE BREAKING UP ON AREA STREAMS AND
CREEKS. THIS WOULD LEAD TO HIGHLY LOCALIZED ICE JAM ISSUES, MAKING
A WIDESPREAD FFA OVERKILL. WITH THIS EVENT STILL A SOLID 42 TO 54
HOURS OUT, SEE TOO MUCH RISK IN RUSHING IN WITH A FLAG THIS EARLY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
FRIDAY NIGHT THE SFC LOW AND ATTENDANT RAIN SHOWERS ARE EXPECTED TO
MOVE NORTH OF THE REGION AND A BRIEF DRY PERIOD WILL RETURN THROUGH
SATURDAY AFTERNOON. ANOTHER COLD FRONT IS EXPECTED TO MOVE THROUGH
THE CWA LATE SAT NIGHT/SUN MORNING BRINGING ANOTHER SHOT OF SNOW
SHOWERS AND COLDER AIR. COLD AIR WILL CONTINUE TO ADVECT INTO THE
REGION AND BY MONDAY MORNING AND 850MB TEMPS WILL FALL TO AROUND
NEGATIVE 18 DEGREES... THUS WE MAY SEE A WEAK LAKE EFFECT RESPONSE
AND SCATTERED SNOW SHOWERS MAY DEVELOP ACROSS THE REGION THROUGH
TUESDAY MORNING. A SFC RIDGE WILL START TO BUILD INTO THE REGION
TUES MORNING FROM THE SW WHICH WILL RESULT IN THE LAKE EFFECT
RESPONSE TO DIMINISH. AFTER TUESDAY GUIDANCE STARTS TO VARY
GREATLY BETWEEN EACH OTHER... AND DECIDED TO JUST KEEP 20 PERCENT
POPS ATTM AS AN ACTIVE PATTERN IS EXPECTED IN THE FAR EXTENDED AND
CONFIDENCE IS LOW ON WHICH MODEL TO FOLLOW.
DECIDED TO GO CLOSELY WITH WPC GUIDANCE WITH TEMPS THROUGH THE
EXTENDED. SAT TEMPS WILL STILL REMAIN IN THE UPR 30S TO MID 40S AS
THE COLD FRONT WONT MOVE THROUGH THE REGION UNTIL LATE SAT NIGHT.
SUNDAY THE COLD AIR WILL RETURN AND WINTER WILL MAKE ITS MARK YET
ONCE AGAIN. TUESDAY MORNING WILL BE PARTICULARLY COLD WITH LOWS
ACROSS CENTRAL NY AND NORTHEAST PA BEING IN THE SINGLE DIGITS.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
SHRT WV ZIPPING THRU THE OH VLY AND GREAT LAKES WILL BRING CLDS
AND MIXED PCPN TO THE AREA AFT 12Z WED. TEMPS ARE VERY MRGNL SO
EXACT PCPN TYPE DFCLT TO FCST...BUT IT DOES APPEAR THAT AT LEAST
OCNL IFR CONDS DUE TO VSBY PSBL FOR SVRL HRS WED. SFC TROF PASSES
AND COLDER AIR MVES IN BHD THE SYSTEM LTR WED BRINGING VFR CONDS.
OUTLOOK...
WED OVERNIGHT TO THU MORN...VFR.
THU AFTN...POSSIBLE RESTRICTIONS IN MIXED PRECIP.
THU NGT...MVFR/IFR RESTRICTIONS POSSIBLE IN FOG/RAIN.
FRI...RESTRICTIONS POSSIBLE IN -RA.
SAT/SUN...MVFR/IFR RESTRICTIONS POSSIBLE IN SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO NOON EST
TODAY FOR PAZ038>040-043-044-047-048-072.
NY...FREEZING RAIN ADVISORY FROM 7 AM THIS MORNING TO NOON EST
TODAY FOR NYZ022>025-044-045-055>057-062.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...DJP
LONG TERM...KAH
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
411 AM EST WED FEB 19 2014
.SYNOPSIS...
WEAK COLD FRONT PUSHES EXITS EAST EARLY TODAY. VIGOROUS SYSTEM
PASSES THURSDAY NIGHT...BUT MILD...PACIFIC AIR FOLLOWS IT AS WELL.
COLD FRONT CROSSES SATURDAY NIGHT,..BEGINNING A TREND TO COLDER.
&&
.NEAR TERM /THROUGH TODAY/...
COLD FRONT MOVING ACROSS THIS MORNING...WITH FEW STORMS EMBEDDED
WITHIN RAIN SHOWERS. INCREASED POPS WITH THIS FEATURE...DECREASING
THEM TO LIKELIES BY THE TIME PCPN REACHES THE MOUNTAINS. USED THE
RAP MODELS FOR POPS TWEAKING THEM DOWN SOME.
EXPECT THE FRONT TO EXIT THE EASTERN MOUNTAINS LATER THIS MORNING
OR EARLY AFTERNOON ENDING CHANCES FOR PCPN. NO SIGNIFICANT PCPN IS
EXPECTED ATTM. UPPER SHELTERED VALLEYS WHERE TEMPERATURES ARE
BELOW FREEZING...FREEZING RAIN WILL BE POSSIBLE FOR A SHORT PERIOD
OF TIME DURING THE PREDAWN HOURS.
BRING POPS BACK FROM THE SOUTH EARLY LATE TONIGHT INTO EARLY
THURSDAY MORNING AS A WARM FRONT LIFT NORTH ACROSS THE AREA.
SOUTHWEST FLOW BRING WARMER TEMPERATURES TO THE AREA.
GENERALLY...TEMPS SHOULD REACH THE UPPER 50S LOWLANDS...RANGING
INTO THE MID 40S NORTHEAST MOUNTAINS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
SPRING SPRINGS THIS PERIOD AS STRONG S FLOW AHEAD OF A VIGOROUS S/W
TROUGH / SFC COLD FRONT BRINGS A RATHER MILD THU...FOLLOWED BY THE
THREAT FOR STRONG THUNDERSTORMS THU EVENING.
BUBBLE HIGH EXITS WED EVENING...ALLOWING STRENGTHENING FLOW FROM THE
S AHEAD OF THE NEXT SYSTEM. WARM FRONT ASSOCIATED WITH THIS SYSTEM
MOVES NWD THROUGH THE AREA EARLY THU MORNING THROUGH THE DAY THU.
ELEVATED INSTABILITY IN THE POSITIVE THETA E ADVECTION COULD LEAD TO
THUNDER AHEAD OF AND ALONG THE WARM FRONT AS PW VALUES CLIMB TO
AROUND AN INCH AND SHOWALTERS GO TO ZERO.
WARM SECTOR BECOMES ESTABLISHED BY THU EVENING...BEFORE COLD FRONT
COMES CHARGING THROUGH OVERNIGHT. PW VALUES GET AS HIGH AS ABOUT
1.25 IN AS SFC DEW POINTS APPROACH 50 AND H85 WIND INCREASE TO 70
KTS OR BETTER. INSTABILITY AXIS JUST AHEAD OF THE COLD FRONT WANES
AS IT CROSSES THE AREA THU NT BUT...GIVEN THE STRONG FLOW
ALOFT...ANY CONVECTIVE LINE THAT GETS GOING UPSTREAM CAN MAINTAIN A
DAMAGING WIND THREAT AT LEAST AS FAR E AS THE E EDGE OF THE SLIGHT
RISK AREA...WHICH CUTS N-S THROUGH HTS...WITH STRONG GUSTS POSSIBLE
WELL E OF THERE. THE RUC WIND GUST MOMENTUM ALGORITHM YIELDS GUSTS
TO 40 KTS OVER THE HIGH TERRAIN AND UP TO 30 KTS OVER THE
LOWLANDS...SO IT WILL TAKE HEAVY SHOWERS...OR THUNDERSTORMS...TO
BRING THE GREATER MOMENTUM DOWN. THE HWO ALREADY CARRIES A SEVERE
THREAT IN THE SLIGHT RISK AREA PER PREVIOUS SHIFT.
USED GFS/NAM BLEND FOR QPF WHICH IS UP NEAR AN INCH IN THE
W...DIMINISHING TO AS LITTLE AS A QUARTER OF AN INCH IN THE
MOUNTAINS...WAY TO LITTLE TO RELEASE THE SNOW PACK EVEN WITH STRONG
WINDS AND DEW POINTS ABOVE FREEZING. THE CANADIAN IS AN ODD MODEL
OUT IN NOT PUSHING THE COLD FRONT THROUGH UNTIL FRI MORNING.
IT APPEARS THE COLD ADVECTION BEHIND THIS COLD FRONT WILL BE TOO
WEAK TO COUNTER DIURNAL HEATING FRI...AS TEMPERATURES WILL RECOVER
TO HIGHS ABOVE NORMAL. A BUBBLE HIGH OF PACIFIC ORIGIN PASSES S OF
THE AREA FRI AFTERNOON...AS LOW PRESSURE INTENSIFIES OVER SERN
CANADA. THE GRADIENT BETWEEN THESE TWO FEATURES WILL PRODUCE STRONG
WINDS...ESPECIALLY ACROSS THE N...WHERE THE MOMENTUM ALGORITHM PUMPS
OUT GUSTS AROUND 30 KTS.
BLENDED IN GFS-BASED BIAS CORRECTED MOS FOR HIGHS AND NAM12 AND THE
MET FOR NON-DIURNAL TEMPERATURES BOTH NTS...OVERALL LITTLE CHANGE
FROM PREVIOUS FCST SAVE FOR TIMING OF COLDER AIR THU NT...A LITTLE
LATER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MODELS SHOWING COLD AIR MOVING BACK INTO THE REGION LATE THIS
WEEKEND. BOTH THE ECMWF AND GFS SHOWING A POTENTIAL ENHANCED CLIPPER
SNOW EARLY NEXT WEEK. HOWEVER...LOTS OF DIFFERENCES IN THE ENSEMBLE
MEMBERS ON THE TIMING OF FEATURES...EVEN THOUGH ENSEMBLES SUPPORT
THE BROADER PATTERN WITH A TROUGH IN THE EAST. THEREFORE...USED THE
ECMWF AND GEFS MEANS...AS CONFIDENCE WITH INDIVIDUAL ENERGY PIECES
IS LOW.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
WIDESPREAD VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST 09Z.
THEN...CONVECTION WILL ENTER SOUTHEAST OH...NORTHEAST KY TO SPREAD
ACROSS WV DURING THE PREDAWN HOURS. INTRODUCED SPATIAL AND TIMING DETAILS
FROM THE HIGH RESOLUTION RAP MODEL WHICH INITIALIZED WELL WITH
RADAR IMAGES.
PRECIPITATION WILL BE IN THE FORM OF -RA...AND WITH A LIGHTNING OR
TWO POSSIBLE. EXPECT BRIEF MVFR CONDITIONS BETWEEN 06Z-18Z
WEDNESDAY IN PRECIPITATION. FLOW AT H85 FROM THE SOUTHWEST ABOUT
40 KNOTS NOT IMPRESSIVE...AND THE ATMOSPHERE SHOULD CONTINUE
DECOUPLED THROUGH AT LEAST 12Z. FLOW BECOMES GUSTY UP TO 35 KTS
ACROSS HIGHER TERRAIN...AND UP TO 22 KTS ACROSS LOWLANDS.
AREAS OF RAIN WILL START CLEARING FROM WEST TO EAST BY EARLY
AFTERNOON...TO AFFECT EKN AND BKW THE LATEST THROUGH AT LEAST 21Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF THE ONSET OF PRECIPITATION AND MVFR
PREVALENT CIGS MAY VARY...AND IMPROVEMENT TO VFR MAY ALSO 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 WED 02/19/14
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 L L L L L L H H H H
HTS CONSISTENCY L L L L L L L L H H H H
BKW CONSISTENCY H L L L L L L L L M M H
EKN CONSISTENCY H H H M M L L L L L L L
PKB CONSISTENCY H L L L L L L L L L L L
CKB CONSISTENCY H H H L L L L L L L L L
AFTER 06Z THURSDAY...
IFR POSSIBLE THURSDAY NIGHT IN GUSTY SHOWERS...AND POSSIBLY A STRONG
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 CHARLESTON WV
103 AM EST WED FEB 19 2014
.SYNOPSIS...
WEAK COLD FRONT PUSHES EAST OVERNIGHT. VIGOROUS SYSTEM PASSES
THURSDAY NIGHT...BUT MILD...PACIFIC AIR FOLLOWS IT AS WELL. A COLD
FRONT CROSSES SATURDAY NIGHT,...BEGINNING A TREND TO COLDER.
&&
.NEAR TERM /THROUGH TODAY/...
SENT AN UPDATE TO ADJUST POPS ACCORDING TO THE RAP HIGH RESOLUTION
MODEL WHICH SHOW BETTER INITIALIZATION AMONG OTHER MODELS
DEVELOPING CONVECTION ASSOCIATED WITH UPCOMING COLD FRONT ACROSS
SOUTHERN OH ...AND KENTUCKY. THIS CONVECTION IS EXPECTED TO REACH
OUR SOUTHEAST OH COUNTIES AROUND 08-09Z. THEN SPREAD EAST TO COVER
MOST PART OF THE AREA.
VERY ISOLATED LIGHTNING HAVE BEEN REPORTED UPSTREAM THIS
CONVECTION. EXPECT ANY STORM TO BE SHORT LIVED...BUT PRODUCE
BRIEF PERIODS OF MODERATE RAINFALL AND SOME STRONG GUSTY WINDS.
PREVIOUS DISCUSSION BELOW...
915 PM UPDATE...NO MAJOR CHANGES NEEDED TO PREVIOUS FORECAST.
PREVIOUS DISCUSSION FOLLOWS...
THE SYSTEM THAT PRODUCED THE PRECIPITATION LAST NIGHT HAS PUSHED
WELL TO OUR EAST...WITH WEAK HIGH PRESSURE NOW IN CONTROL OF THE
REGION. THE COMBINATION OF ABUNDANT SUNSHINE AND GUSTY SOUTHWESTERLY
WINDS HAVE PUSHED TEMPERATURES INTO THE MID 40S TO MID 50S ACROSS
MUCH OF THE AREA.
THE HIGH WILL PUSH EAST TONIGHT...ALLOWING A COLD FRONT TO
APPROACH FROM THE WEST. EXPECT CLOUDS WILL INCREASE...WITH
PRECIPITATION EXPECTED TO SPREAD NORTHEAST ACROSS THE AREA AFT 06
UTC.
THE COLD FRONT WILL PUSH EAST ON WEDNESDAY...BRINGING THE
PRECIPITATION CHANCES TO AN END.
WITH NAM/GFS AS WELL AS WPC ALL INDICATING MEASURABLE
PRECIPITATION...HAVE BUMPED POPS TO LIKELY...ALONG AND AHEAD OF THE
FRONT. LOOKS LIKE THIS WILL BE A HIGH POP...LOW QPF EVENT.
LATEST TEMP GUIDANCE SUGGESTS LOW TEMP FORECAST FOR TONIGHT AND
HIGHS ON WEDNESDAY ARE IN THE BALLPARK...SO HAVE ONLY MADE SOME
MINOR TWEAKS.
WITH WARMING TEMPS ALOFT AND MOST OF THE REGION SHOULD BE ABOVE
FREEZING AT THE SURFACE...RAIN SHOULD BE THE PREDOMINANT WEATHER
TYPE.
INITIALLY THOUGHT SOME OF THE SHELTERED NORTHERN MOUNTAIN VALLEYS
WILL BE COLD ENOUGH FOR THE PRECIPITATION TO BE IN THE FORM OF
FREEZING RAIN. BUT IT NOW LOOKS LIKE TEMPERATURES WILL FALL
EARLY...AND THEN WARM AS THE CLOUDS AND PRECIPITATION MOVE IN.
MAY BE SOME ISOLATED LOCATIONS THAT COULD SEE FREEZING RAIN...BUT IT
SHOULD NOT LAST LONG...AND BE VERY LIGHT. WITH THIS CHANGE...DO NOT
THINK THERE IS THE NEED FOR ANY FREEZING RAIN ADVISORIES.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
SPRING SPRINGS THIS PERIOD AS STRONG S FLOW AHEAD OF A VIGOROUS S/W
TROUGH / SFC COLD FRONT BRINGS A RATHER MILD THU...FOLLOWED BY THE
THREAT FOR STRONG THUNDERSTORMS THU EVENING.
BUBBLE HIGH EXITS WED EVENING...ALLOWING STRENGTHENING FLOW FROM THE
S AHEAD OF THE NEXT SYSTEM. WARM FRONT ASSOCIATED WITH THIS SYSTEM
MOVES NWD THROUGH THE AREA EARLY THU MORNING THROUGH THE DAY THU.
ELEVATED INSTABILITY IN THE POSITIVE THETA E ADVECTION COULD LEAD TO
THUNDER AHEAD OF AND ALONG THE WARM FRONT AS PW VALUES CLIMB TO
AROUND AN INCH AND SHOWALTERS GO TO ZERO.
WARM SECTOR BECOMES ESTABLISHED BY THU EVENING...BEFORE COLD FRONT
COMES CHARGING THROUGH OVERNIGHT. PW VALUES GET AS HIGH AS ABOUT
1.25 IN AS SFC DEW POINTS APPROACH 50 AND H85 WIND INCREASE TO 70
KTS OR BETTER. INSTABILITY AXIS JUST AHEAD OF THE COLD FRONT WANES
AS IT CROSSES THE AREA THU NT BUT...GIVEN THE STRONG FLOW
ALOFT...ANY CONVECTIVE LINE THAT GETS GOING UPSTREAM CAN MAINTAIN A
DAMAGING WIND THREAT AT LEAST AS FAR E AS THE E EDGE OF THE SLIGHT
RISK AREA...WHICH CUTS N-S THROUGH HTS...WITH STRONG GUSTS POSSIBLE
WELL E OF THERE. THE RUC WIND GUST MOMENTUM ALGORITHM YIELDS GUSTS
TO 40 KTS OVER THE HIGH TERRAIN AND UP TO 30 KTS OVER THE
LOWLANDS...SO IT WILL TAKE HEAVY SHOWERS...OR THUNDERSTORMS...TO
BRING THE GREATER MOMENTUM DOWN. THE HWO ALREADY CARRIES A SEVERE
THREAT IN THE SLIGHT RISK AREA PER PREVIOUS SHIFT.
USED GFS/NAM BLEND FOR QPF WHICH IS UP NEAR AN INCH IN THE
W...DIMINISHING TO AS LITTLE AS A QUARTER OF AN INCH IN THE
MOUNTAINS...WAY TO LITTLE TO RELEASE THE SNOW PACK EVEN WITH STRONG
WINDS AND DEW POINTS ABOVE FREEZING. THE CANADIAN IS AN ODD MODEL
OUT IN NOT PUSHING THE COLD FRONT THROUGH UNTIL FRI MORNING.
IT APPEARS THE COLD ADVECTION BEHIND THIS COLD FRONT WILL BE TOO
WEAK TO COUNTER DIURNAL HEATING FRI...AS TEMPERATURES WILL RECOVER
TO HIGHS ABOVE NORMAL. A BUBBLE HIGH OF PACIFIC ORIGIN PASSES S OF
THE AREA FRI AFTERNOON...AS LOW PRESSURE INTENSIFIES OVER SERN
CANADA. THE GRADIENT BETWEEN THESE TWO FEATURES WILL PRODUCE STRONG
WINDS...ESPECIALLY ACROSS THE N...WHERE THE MOMENTUM ALGORITHM PUMPS
OUT GUSTS AROUND 30 KTS.
BLENDED IN GFS-BASED BIAS CORRECTED MOS FOR HIGHS AND NAM12 AND THE
MET FOR NON-DIURNAL TEMPERATURES BOTH NTS...OVERALL LITTLE CHANGE
FROM PREVIOUS FCST SAVE FOR TIMING OF COLDER AIR THU NT...A LITTLE
LATER.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS SHOWING COLD AIR MOVING BACK INTO THE REGION LATE THIS
WEEKEND. BOTH THE ECMWF AND GFS SHOWING A POTENTIAL ENHANCED CLIPPER
SNOW EARLY NEXT WEEK. HOWEVER...LOTS OF DIFFERENCES IN THE ENSEMBLE
MEMBERS ON THE TIMING OF FEATURES...EVEN THOUGH ENSEMBLES SUPPORT
THE BROADER PATTERN WITH A TROUGH IN THE EAST. THEREFORE...USED THE
ECMWF AND GEFS MEANS...AS CONFIDENCE WITH INDIVIDUAL ENERGY PIECES
IS LOW.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
WIDESPREAD VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST 09Z.
THEN...CONVECTION WILL ENTER SOUTHEAST OH...NORTHEAST KY TO SPREAD
ACROSS WV DURING THE PREDAWN HOURS. INTRODUCED SPATIAL AND TIMING DETAILS
FROM THE HIGH RESOLUTION RAP MODEL WHICH INITIALIZED WELL WITH
RADAR IMAGES.
PRECIPITATION WILL BE IN THE FORM OF -RA...AND WITH A LIGHTNING OR
TWO POSSIBLE. EXPECT BRIEF MVFR CONDITIONS BETWEEN 06Z-18Z
WEDNESDAY IN PRECIPITATION. FLOW AT H85 FROM THE SOUTHWEST ABOUT
40 KNOTS NOT IMPRESSIVE...AND THE ATMOSPHERE SHOULD CONTINUE
DECOUPLED THROUGH AT LEAST 12Z. FLOW BECOMES GUSTY UP TO 35 KTS
ACROSS HIGHER TERRAIN...AND UP TO 22 KTS ACROSS LOWLANDS.
AREAS OF RAIN WILL START CLEARING FROM WEST TO EAST BY EARLY
AFTERNOON...TO AFFECT EKN AND BKW THE LATEST THROUGH AT LEAST 21Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF THE ONSET OF PRECIPITATION AND MVFR
PREVALENT CIGS MAY VARY...AND IMPROVEMENT TO VFR MAY ALSO 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 WED 02/19/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H H H H L L L L L L H H
HTS CONSISTENCY H H L L L L L L L L H H
BKW CONSISTENCY H H H L L L L L L L L M
EKN CONSISTENCY H H H H H M M L L L L L
PKB CONSISTENCY H H H L L L L L L L L L
CKB CONSISTENCY H H H H H L L L L L L L
AFTER 06Z THURSDAY...
IFR POSSIBLE THURSDAY NIGHT IN GUSTY SHOWERS...AND POSSIBLY A STRONG
THUNDERSTORM.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JSH/ARJ/TRM/RPY
NEAR TERM...JSH/ARJ/SL
SHORT TERM...TRM
LONG TERM...RPY
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
443 AM EST WED FEB 19 2014
.SYNOPSIS...
A FAST MOVING UPPER LEVEL TROUGH WILL SLIDE ACROSS THE LOWER
GREAT LAKES AND NORTHERN MID-ATLANTIC STATES TODAY...WITH
SECONDARY SURFACE LOW DEVELOPMENT FROM THE SOUTHERN NEW ENGLAND
COAST INTO THE CANADIAN MARITIMES...SIMILAR TO YESTERDAY. A WEAK
AREA OF HIGH PRESSURE WILL MIGRATE OVER THE REGION TONIGHT INTO
EARLY THURSDAY BEHIND THE DEPARTING SYSTEM. A WARM FRONT WILL LIFT
NORTH ACROSS THE AREA THURSDAY NIGHT...BEFORE A STRONG COLD FRONT
SWEEPS THROUGH THE COMMONWEALTH ON FRIDAY. TEMPERATURES SHOULD
AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL INTO WEEKEND BEFORE
TRENDING COLDER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
**UPDATE** EXPANDED ZR ADVY FOR REST OF CWA /LAURELS AND
WARREN COUNTY/. OBSERVATIONS FROM PBZ AREA INDICATE THAT DESPITE
TEMPS AOA 32F...RAIN IS FREEZING ON CONTACT DUE TO COLD GROUND
TEMPS.
INCREASING LG SCALE LIFT/500MB HGT FALLS ASSOC WITH APPROACHING
GRT LKS SHORTWAVE MID/UPPER LEVEL TROUGH...AND STG WARM AIR/THETAE
ADVECTION/ISENT LIFT ON NOSE OF 40+KT SWLY LLJ IS RESULTING IN
FAST-MOVG AREA OF PCPN ACRS SE OH/NW WV MOVG INTO SW PA NEAR PIT
AS OF 09Z. SHORT RANGE MESO MODELS BRING THIS PCPN INTO CENTRAL PA
DURING THE PRE-DAWN AND EARLY MORNING HOURS /EXTRAPOLATED TOA IS
APPROX 0930Z IN THE SW ZONES AND AROUND 12Z IN THE ERN
COUNTIES/...OVERSPREADING A COMPLEX LOW-LEVEL THERMAL PROFILE.
LATEST RUC DATA INDICATES 925-850MB TEMPS ARE ABOVE 0C ACRS THE
ENTIRE CWA...BUT THIS CHANGES FOR SOME AREAS AFT FACTORING IN WET
BULB EFFECTS GIVEN DRY AIR IN PLACE WITH RATHER LARGE DEWPT
DEPRESSIONS. TO FURTHER COMPLICATE MATTERS...SFC TEMPS VARY WIDELY
WITH CNTRL-ERN SITES CALM/DECOUPLED AND WRN SITES WEAKLY MIXED AOA
32F. TO GET A SENSE OF THIS GRADIENT...THE 08Z THE TEMP DIFF FROM
MGW TO SEG WAS 34 DEGREES...48F VS. 14F. THE LOCAL TEMP HERE AT
THE OFFICE IS AROUND 19-20F.
MADE NO CHANGES TO ZR ADVY HEADLINE COVERING NEARLY ALL OF THE
CWA. HOWEVER CONCERN IS FOR MULTIPLE PTYPE SCENARIO GIVEN
COMPLEXITY OF BLYR THERMAL STRUCTURE+WET BULB EFFECTS...WITH THE
GREATEST POTNL FOR AN INITIAL PERIOD OF SNOW (MOST LKLY SLEET)
ACRS NERN 1/2 OF THE CWA...ESPECIALLY THE ENDLESS MTN/SRN POCONO
REGION NE OF THE LYCOMING VALLEY/IPT. ANTICIPATE UPDATING THE WX
GRIDS ONCE THE PCPN TYPES START TO SHOW THEIR HAND OVER THE NEXT
1-3 HRS.
TEMPS SHOULD WARM ABOVE FZG BY MIDDAY THUS ENDING THE THREAT FOR
ZR. WILL NEED TO SEE IF MDLS ARE TOO AGGRESSIVE IN WARMING TEMPS
GIVEN THE INITIAL WET BULBING AT THE ONSET OF PCPN. TEMPS SHOULD
START TO WARM ONCE WINDS SHIFT TO THE WEST BEHIND OCCLD FRNT. ONCL
LGT RAIN WILL CONTINUE INTO THE EARLY AFTN WITH THE HIGHEST POPS
OVER THE ERN ZONES BASED ON A CONSENSUS BLEND OF MDL QPFS...AND
NEAR SECONDARY SFC LOW DEVELOPING INVOF THE NJ COAST. A RAIN/SNOW
MIX IS POSSIBLE OVER THE NW MTNS AS COLDER AIR ALOFT ARRIVES ON
THE BACKSIDE OF THE SHORTWAVE TROUGH.
PCPN ENDS FROM SW TO NE BY THIS EVE AS HIGH PRES MIGRATES EWD FROM
THE UPPER OH VLY INTO PA...PROVIDING DRY WX FOR THE OVERNIGHT PD.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
A STRONG MID-LVL TROUGH CROSSING THE PLAINS STATES THURS IS FCST
TO TAKE ON A NEGATIVE TILT AS IT REACHES THE UPPER GRT LKS AND
MS/OH VLYS THURS NGT. AT THE SFC...HIGH PRES WILL SHIFT OFF THE
MID-ATL COAST EARLY THURS AS A WARM FRONT...EXTENDING EWD FROM
DEEPENING SFC LOW MOVG NNEWD FROM SERN KN TO LK SUPERIOR BY THE
END OF THE PD...LIFTS NWD ACRS THE AREA BY 00Z FRI. 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 LINE OF LOW-TOPPED CONVECTION WHICH
COULD REACH THE WRN ALLEGHENIES EARLY FRI MORNING.
QUESTION FOR THURS WILL BE THE EXTENT OF THE LLVL CAD PATTERN
GIVEN THE EXPECTED ONSLAUGHT OF LLVL WAA IN ADVANCE OF DYNAMIC
MIDWEST SYSTEM. THE HIRES NAM SHOWS NELY AGEO WINDS HOLDING SFC
TEMPS IN THE 35-40F RANGE WITH SOME OVERRUNNING PCPN SPREADING
INTO NWRN SECTIONS. SREF DATA SHOWS THE DOMINANT PTYPES AS RAIN
WITH VERY LOW PROBS FOR FROZEN/FZG PCPN IN THE N-CNTRL MTNS/N OF
I-80. IN GENERAL..STAYED VERY CLOSE TO CONSENSUS BLEND FOR MOST
ELEMENTS...WHICH FAVORED DAYTIME TEMPS AROUND 40F AND CATEGORICAL
POPS ACRS THE FAR NW ZONES THURS NGT. SPC DAY 2+3 OUTLOOKS PLACES
THE AREA IN GENERAL RISK HOWEVER MAY NEED TO ADD ENHANCED WORDING
IN HWO DUE TO POSSIBLE NCFRB/LOW TOPPED SQ LINE RACING ACRS THE
AREA DURING THE PRE-DAWN AND MORNING HOURS FRI. 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
SNOWMELT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
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.
BROAD TROUGH DEVELOPS ACROSS EASTERN 2/3RDS OF U.S. FOR THE
WEEKEND...GIVING US A SLOW AND STEADY RETURN BACK TO SLIGHTLY
BELOW NORMAL TEMPERATURES. WEAK FRONT PUSHES THROUGH MID-WEEKEND
THAT MAY BRING LIGHT ACCUMS OF SNOW. OTHERWISE...NO BIG SYSTEMS ON
THE HORIZON. SNOWFLAKES WILL LINGER OVER THE WESTERN/NORTHERN
HIGHER TERRAIN IN PERSISTENT NW/W FLOW.
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 WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE...CLEAR SKIES...LIGHT WINDS AND SNOWPACK HAVE ALLOWED
FOR FOG/MIST ACROSS SOUTHEASTERN AND CENTRAL PA OVERNIGHT. THE
THICKEST FOG WAS AT LNS...AND THAT HAS SINCE LIFTED. THERE IS A
CHANCE FOR FOG AT LNS BETWEEN 11Z-15Z...OUT AHEAD OF THE NEXT BAND
OF PRECIPITATION. EXPECT FOG/MIST AT UNV...MDT AND LNS AND SHOULD
CONTINUE THROUGH MID MORNING.
PRECIP ASSOCIATED WITH THE APPROACHING COLD FRONT WILL BEGIN
MOVING INTO SOUTHWESTERN AREAS AROUND OR JUST BEFORE
DAWN...PROBABLY IN THE FORM OF FREEZING RAIN/DRIZZLE OR A LIGHT
WINTRY MIX. MOST TERMINALS WILL LIKELY EXPERIENCE A LIGHT ICING
ISSUE FOR A FEW HOURS AS THE PRECIP MOVES INTO THE REGION. THE
THREAT FOR ICING SHOULD DIMINISH BY MID TO LATE MORNING AS
TEMPERATURES RECOVER SLOWLY ABOVE FREEZING. MVFR/IFR CAN BE
EXPECTED WITH THE COMBINATION OF THE MILDER AIR AND LIGHT PRECIP
MOVING IN OVER OUR DEEP SNOW PACK.
THE COLD FRONT SHOULD MOVE THROUGH THE AREA BY EARLY TO MID
AFTERNOON...FOLLOWED BY A COOLER AND DRIER NW FLOW IN THE WAKE OF
THE FRONT. THERE COULD BE SOME LINGERING MVFR/IFR IN SCATTERED
RAIN OR SNOW SHOWERS...BUT THESE WILL BE VERY BRIEF AND CONFINED
TO THE WESTERN MOUNTAINS.
OUTLOOK...
THU...MVFR/IFR LIKELY WITH SHOWERS AND FOG.
FRI...SHRA/REDUCED CIGS LIKELY.
SAT...NO SIG WX EXPECTED.
SUN...MVFR/SCT SHSN NW. MAINLY VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR PAZ006-012-037-
041-042-045-046-049>053-057>059.
FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ004-
005-010-011-017>019-024>028-033>036-056-063>066.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...RXR
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
412 AM EST WED FEB 19 2014
.SYNOPSIS...
A FAST MOVING UPPER LEVEL TROUGH WILL SLIDE ACROSS THE LOWER
GREAT LAKES AND NORTHERN MID-ATLANTIC STATES TODAY...WITH
SECONDARY SURFACE LOW DEVELOPMENT FROM THE SOUTHERN NEW ENGLAND
COAST INTO THE CANADIAN MARITIMES...SIMILAR TO YESTERDAY. A WEAK
AREA OF HIGH PRESSURE WILL MIGRATE OVER THE REGION TONIGHT INTO
EARLY THURSDAY BEHIND THE DEPARTING SYSTEM. A WARM FRONT WILL LIFT
NORTH ACROSS THE AREA THURSDAY NIGHT...BEFORE A STRONG COLD FRONT
SWEEPS THROUGH THE COMMONWEALTH ON FRIDAY. TEMPERATURES SHOULD
AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL INTO WEEKEND BEFORE
TRENDING COLDER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
INCREASING LG SCALE LIFT/500MB HGT FALLS ASSOC WITH APPROACHING
GRT LKS SHORTWAVE MID/UPPER LEVEL TROUGH...AND STG WARM AIR/THETAE
ADVECTION/ISENT LIFT ON NOSE OF 40+KT SWLY LLJ IS RESULTING IN
FAST-MOVG AREA OF PCPN ACRS SE OH/NW WV MOVG INTO SW PA NEAR PIT
AS OF 09Z. SHORT RANGE MESO MODELS BRING THIS PCPN INTO CENTRAL PA
DURING THE PRE-DAWN AND EARLY MORNING HOURS /EXTRAPOLATED TOA IS
APPROX 0930Z IN THE SW ZONES AND AROUND 12Z IN THE ERN
COUNTIES/...OVERSPREADING A COMPLEX LOW-LEVEL THERMAL PROFILE.
LATEST RUC DATA INDICATES 925-850MB TEMPS ARE ABOVE 0C ACRS THE
ENTIRE CWA...BUT THIS CHANGES FOR SOME AREAS AFT FACTORING IN WET
BULB EFFECTS GIVEN DRY AIR IN PLACE WITH RATHER LARGE DEWPT
DEPRESSIONS. TO FURTHER COMPLICATE MATTERS...SFC TEMPS VARY WIDELY
WITH CNTRL-ERN SITES CALM/DECOUPLED AND WRN SITES WEAKLY MIXED AOA
32F. TO GET A SENSE OF THIS GRADIENT...THE 08Z THE TEMP DIFF FROM
MGW TO SEG WAS 34 DEGREES...48F VS. 14F. THE LOCAL TEMP HERE AT
THE OFFICE IS AROUND 19-20F.
MADE NO CHANGES TO ZR ADVY HEADLINE COVERING NEARLY ALL OF THE
CWA. HOWEVER CONCERN IS FOR MULTIPLE PTYPE SCENARIO GIVEN
COMPLEXITY OF BLYR THERMAL STRUCTURE+WET BULB EFFECTS...WITH THE
GREATEST POTNL FOR AN INITIAL PERIOD OF SNOW (MOST LKLY SLEET)
ACRS NERN 1/2 OF THE CWA...ESPECIALLY THE ENDLESS MTN/SRN POCONO
REGION NE OF THE LYCOMING VALLEY/IPT. ANTICIPATE UPDATING THE WX
GRIDS ONCE THE PCPN TYPES START TO SHOW THEIR HAND OVER THE NEXT
1-3 HRS.
TEMPS SHOULD WARM ABOVE FZG BY MIDDAY THUS ENDING THE THREAT FOR
ZR. WILL NEED TO SEE IF MDLS ARE TOO AGGRESSIVE IN WARMING TEMPS
GIVEN THE INITIAL WET BULBING AT THE ONSET OF PCPN. TEMPS SHOULD
START TO WARM ONCE WINDS SHIFT TO THE WEST BEHIND OCCLD FRNT. ONCL
LGT RAIN WILL CONTINUE INTO THE EARLY AFTN WITH THE HIGHEST POPS
OVER THE ERN ZONES BASED ON A CONSENSUS BLEND OF MDL QPFS...AND
NEAR SECONDARY SFC LOW DEVELOPING INVOF THE NJ COAST. A RAIN/SNOW
MIX IS POSSIBLE OVER THE NW MTNS AS COLDER AIR ALOFT ARRIVES ON
THE BACKSIDE OF THE SHORTWAVE TROUGH.
PCPN ENDS FROM SW TO NE BY THIS EVE AS HIGH PRES MIGRATES EWD FROM
THE UPPER OH VLY INTO PA...PROVIDING DRY WX FOR THE OVERNIGHT PD.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
A STRONG MID-LVL TROUGH CROSSING THE PLAINS STATES THURS IS FCST
TO TAKE ON A NEGATIVE TILT AS IT REACHES THE UPPER GRT LKS AND
MS/OH VLYS THURS NGT. AT THE SFC...HIGH PRES WILL SHIFT OFF THE
MID-ATL COAST EARLY THURS AS A WARM FRONT...EXTENDING EWD FROM
DEEPENING SFC LOW MOVG NNEWD FROM SERN KN TO LK SUPERIOR BY THE
END OF THE PD...LIFTS NWD ACRS THE AREA BY 00Z FRI. 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 LINE OF LOW-TOPPED CONVECTION WHICH
COULD REACH THE WRN ALLEGHENIES EARLY FRI MORNING.
QUESTION FOR THURS WILL BE THE EXTENT OF THE LLVL CAD PATTERN
GIVEN THE EXPECTED ONSLAUGHT OF LLVL WAA IN ADVANCE OF DYNAMIC
MIDWEST SYSTEM. THE HIRES NAM SHOWS NELY AGEO WINDS HOLDING SFC
TEMPS IN THE 35-40F RANGE WITH SOME OVERRUNNING PCPN SPREADING
INTO NWRN SECTIONS. SREF DATA SHOWS THE DOMINANT PTYPES AS RAIN
WITH VERY LOW PROBS FOR FROZEN/FZG PCPN IN THE N-CNTRL MTNS/N OF
I-80. IN GENERAL..STAYED VERY CLOSE TO CONSENSUS BLEND FOR MOST
ELEMENTS...WHICH FAVORED DAYTIME TEMPS AROUND 40F AND CATEGORICAL
POPS ACRS THE FAR NW ZONES THURS NGT. SPC DAY 2+3 OUTLOOKS PLACES
THE AREA IN GENERAL RISK HOWEVER MAY NEED TO ADD ENHANCED WORDING
IN HWO DUE TO POSSIBLE NCFRB/LOW TOPPED SQ LINE RACING ACRS THE
AREA DURING THE PRE-DAWN AND MORNING HOURS FRI. 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
SNOWMELT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
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.
BROAD TROUGH DEVELOPS ACROSS EASTERN 2/3RDS OF U.S. FOR THE
WEEKEND...GIVING US A SLOW AND STEADY RETURN BACK TO SLIGHTLY
BELOW NORMAL TEMPERATURES. WEAK FRONT PUSHES THROUGH MID-WEEKEND
THAT MAY BRING LIGHT ACCUMS OF SNOW. OTHERWISE...NO BIG SYSTEMS ON
THE HORIZON. SNOWFLAKES WILL LINGER OVER THE WESTERN/NORTHERN
HIGHER TERRAIN IN PERSISTENT NW/W FLOW.
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 /08Z WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE...CLEAR SKIES...LIGHT WINDS AND SNOWPACK HAVE ALLOWED
FOR FOG/MIST ACROSS SOUTHEASTERN AND CENTRAL PA OVERNIGHT. THE
THICKEST FOG WAS AT LNS...AND THAT HAS SINCE LIFTED. THERE IS A
CHANCE FOR FOG AT LNS BETWEEN 11Z-15Z...OUT AHEAD OF THE NEXT BAND
OF PRECIPITATION. EXPECT FOG/MIST AT UNV...MDT AND LNS AND SHOULD
CONTINUE THROUGH MID MORNING.
PRECIP ASSOCIATED WITH THE APPROACHING COLD FRONT WILL BEGIN
MOVING INTO SOUTHWESTERN AREAS AROUND OR JUST BEFORE
DAWN...PROBABLY IN THE FORM OF FREEZING RAIN/DRIZZLE OR A LIGHT
WINTRY MIX. MOST TERMINALS WILL LIKELY EXPERIENCE A LIGHT ICING
ISSUE FOR A FEW HOURS AS THE PRECIP MOVES INTO THE REGION. THE
THREAT FOR ICING SHOULD DIMINISH BY MID TO LATE MORNING AS
TEMPERATURES RECOVER SLOWLY ABOVE FREEZING. MVFR/IFR CAN BE
EXPECTED WITH THE COMBINATION OF THE MILDER AIR AND LIGHT PRECIP
MOVING IN OVER OUR DEEP SNOW PACK.
THE COLD FRONT SHOULD MOVE THROUGH THE AREA BY EARLY TO MID
AFTERNOON...FOLLOWED BY A COOLER AND DRIER NW FLOW IN THE WAKE OF
THE FRONT. THERE COULD BE SOME LINGERING MVFR/IFR IN SCATTERED
RAIN OR SNOW SHOWERS...BUT THESE WILL BE VERY BRIEF AND CONFINED
TO THE WESTERN MOUNTAINS.
OUTLOOK...
THU...MVFR/IFR LIKELY WITH SHOWERS AND FOG.
FRI...SHRA/REDUCED CIGS LIKELY.
SAT...NO SIG WX EXPECTED.
SUN...MVFR/SCT SHSN NW. MAINLY VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR PAZ006-012-037-
041-042-045-046-049>053-057>059.
FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ005-
010-011-017>019-025>028-034>036-056-063>066.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...RXR
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
354 AM CST WED FEB 19 2014
.SHORT TERM (TODAY THROUGH THURSDAY)...
SURFACE OBSERVATIONS AND SATELLITE IMAGERY SHOW FOG AND LOW CLOUDS
ARE CURRENTLY IN PLACE ACROSS SOUTH CENTRAL TEXAS. BASED ON RECENT
TRENDS AND THE LATEST HI-RES RUC MODEL...WE HAVE INCLUDED A
MENTION OF PATCHY...DENSE FOG ACROSS THE HILL COUNTRY AND SOUTHERN
EDWARDS PLATEAU. THE FOG IS EXPECTED TO DECREASE BY MID-MORNING AS
SOUTHERLY WINDS AND DAYTIME HEATING COMMENCE. AFTERNOON
TEMPERATURES WILL WARM TO ABOVE NORMAL LEVELS TODAY... WITH HIGHS
RANGING FROM THE UPPER 80S ALONG THE RIO GRANDE TO UPPER 70S ALONG
THE HIGHWAY 77 CORRIDOR. MOIST CONDITIONS REMAIN IN PLACE TONIGHT
AND WE/LL CONTINUE TO MENTION FOG AND DRIZZLE ACROSS MOST AREAS. A
PACIFIC COLD FRONT WILL MOVE THROUGH THE REGION ON THURSDAY. IN
ADVANCE OF THE FRONT...CAN/T RULE OUT SOME LIGHT MORNING SHOWERS
ALONG AND EAST OF THE I-35 CORRIDOR. WE/LL ALSO CONTINUE TO
MENTION A SLIGHT CHANCE FOR AFTERNOON THUNDERSTORMS EAST OF I-35
AS THE COLD FRONT WILL BE ACROSS THIS REGION DURING PEAK HEATING.
THE COLD FRONT WILL ALSO BRING AN INCREASE IN FIRE WEATHER
CONCERNS FOR AREAS ALONG AND WEST OF I-35. PLEASE SEE THE BELOW
FIRE WEATHER SECTION FOR MORE INFORMATION.
&&
.LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
WINDS WILL DECREASE THURSDAY NIGHT AS SKIES REMAIN MOSTLY CLEAR.
THIS ALONG WITH DRY AIR WILL ALLOW TEMPERATURES TO DROP INTO THE
LOWER 30S ACROSS THE HILL COUNTRY TO THE MID 40S COASTAL PLAINS.
SOUTHERLY FLOW IN THE LOW-LEVELS RESUMES ON FRIDAY AS ZONAL FLOW
ALOFT PERSISTS. A WARMING TREND IS EXPECTED SATURDAY AS THE LATEST
MEDIUM RANGE MODELS SHOW A COLD FRONT REMAINING NORTH OF THE
REGION. THERE IS SOME DISAGREEMENT AMONG THE MEDIUM RANGE MODELS
WITH REGARDS TO THE SOUTHWARD PROGRESS OF THE COLD FRONT ON
SUNDAY. FOR NOW...WILL SHOW SOME SLIGHTLY COOLER TEMPERATURES
NORTH OF I-10...WITH LITTLE CHANGE ELSEWHERE. THE FLOW ALOFT OVER
THE WESTERN U.S. WILL AMPLIFY EARLY NEXT WEEK...BUT DOES NOT
CHANGE SIGNIFICANTLY ACROSS THE SOUTHERN PLAINS. THIS PATTERN DOES
FAVOR PERIODIC COLD FRONTS MOVING INTO THE REGION AND WE/LL SHOW
SOME NEAR TO BELOW NORMAL TEMPERATURES ON TUESDAY. SOME LIGHT
SHOWERS ARE POSSIBLE EARLY NEXT WEEK...BUT OVERALL AMOUNTS AND
PRECIPITATION CHANCES WILL REMAIN LOW.
&&
.FIRE WEATHER...
CRITICAL TO NEAR CRITICAL FIRE WEATHER CONDITIONS ARE LIKELY FOR
AREAS MAINLY ALONG AND WEST OF THE I-35 CORRIDOR THURSDAY
AFTERNOON IN THE WAKE OF A PACIFIC COLD FRONT. RELATIVE HUMIDITIES
WILL DROP INTO THE TEENS WITH NORTH WINDS OF 15 TO 25 MPH AND
GUSTY FOLLOWING THE FRONTAL PASSAGE. ELEVATED FIRE WEATHER
CONDITIONS ARE POSSIBLE FRIDAY AFTERNOON MAINLY ALONG AND WEST OF
THE I-35 CORRIDOR AS RELATIVE HUMIDITIES AGAIN FALL INTO THE
TEENS WITH SOUTHERLY WINDS OF 10 TO 15 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 64 81 43 72 / - - 20 - -
AUSTIN BERGSTROM INTL AIRPORT 79 61 81 36 71 / - - 20 - -
NEW BRAUNFELS MUNI AIRPORT 80 61 83 39 73 / - - 20 - -
BURNET MUNI AIRPORT 78 60 76 37 69 / - - 20 - -
DEL RIO INTL AIRPORT 88 58 86 43 74 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 79 62 78 38 69 / - - 20 - -
HONDO MUNI AIRPORT 85 59 86 40 75 / - - 10 0 -
SAN MARCOS MUNI AIRPORT 79 62 81 39 71 / - - 20 - -
LA GRANGE - FAYETTE REGIONAL 78 64 79 42 69 / - 10 20 10 -
SAN ANTONIO INTL AIRPORT 82 63 85 44 74 / - - 10 - -
STINSON MUNI AIRPORT 82 62 86 43 73 / - - 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING
FOR THE FOLLOWING COUNTIES: BANDERA...BASTROP...BEXAR...BLANCO...
BURNET...CALDWELL...COMAL...DIMMIT...EDWARDS...FRIO...GILLESPIE...
GUADALUPE...HAYS...KENDALL...KERR...KINNEY...LLANO...MAVERICK...
MEDINA...REAL...TRAVIS...UVALDE...VAL VERDE...WILLIAMSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...24
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
351 AM CST WED FEB 19 2014
.UPDATE...
ISSUED AT 351 AM CST WED FEB 19 2014
PRELIMINARY HEADLINES BELOW. MAJOR AFD COMING AROUND 415 AM.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 321 PM CST TUE FEB 18 2014
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED SHORTWAVE TROUGHS OVER MANITOBA AND OVER EASTERN
SOUTH DAKOTA INTO NEBRASKA...RIDGING OVER THE NORTHERN
ROCKIES...AND A POTENT UPPER TROUGH JUST OFF THE BRITISH COLUMBIA
AND PACIFIC NORTHWEST COASTS. THIS POTENT UPPER TROUGH IS THE
CULPRIT FOR OUR THURSDAY STORM. DPVA AND PACIFIC MOISTURE AHEAD OF
THE TWO SHORTWAVE TROUGHS HAVE BEEN SPREADING MID AND HIGH CLOUDS
ACROSS THE FORECAST AREA TODAY. THESE CLOUDS HAVE LIMITED SOME
INSULATION...BUT SOUTHWESTERLY 925-850MB FLOW AHEAD OF A COLD
FRONT MOVING INTO THE FORECAST AREA HELPED BOOST TEMPERATURES INTO
THE 30S TO MID 40S THIS AFTERNOON. OVER WESTERN IOWA WHERE NO SNOW
EXISTS...READINGS ARE IN THE 50S TO LOW 60S. IN THE WAKE OF THE
COLD FRONT...READINGS ARE STILL IN THE 30S AND 40S...PARTIALLY DUE
TO A BIT MORE SUN AND DOWNSLOPING FLOW OFF THE NORTHERN ROCKIES.
THE QUIET BEFORE THE STORM PHRASE WORKS PERFECTLY FOR THE SHORT
TERM. 18.12Z MODEL GUIDANCE DEPICT THE RIDGING OVER THE NORTHERN
ROCKIES MARCHING EASTWARD TO ABOUT OVER THE FORECAST AREA BY 00Z
THU...PUSHED BY THE POTENT NORTHEAST PACIFIC NORTHWEST TROUGH
PLOWING INTO THE ROCKIES. ON THE EAST SIDE OF THE UPPER RIDGE AXIS
THERE IS A WEAK SHORTWAVE AT 500MB SUGGESTED TO DROP SOUTHEAST
THROUGH THE FORECAST AREA LATE TONIGHT...BUT THIS FEATURE WILL COME
THROUGH DRY WITH BASICALLY NO CLOUD.
ONLY REAL ISSUE TO CONTEND WITH TONIGHT IS IF ANY FOG CAN FORM
RESULTING FROM MELTING SNOW. ALL MODELS KEEP A DECENT PRESSURE
GRADIENT IN PLACE TONIGHT WITH A SURFACE RIDGE AXIS ONLY REACHING
WESTERN MN BY 12Z WED. 925MB WINDS STAY UP 20-30 KT FOR MUCH OF THE
NIGHT IN THE WAKE OF THE COLD FRONTAL PASSAGE THIS EVENING.
THUS...THINK ANY FOG WOULD BE LIMITED TO PERHAPS THE TYPICAL COLD
SPOTS AND SOME SMALL VALLEYS.
PLENTY OF SUN LOOKS ON TAP FOR WEDNESDAY...OUTSIDE OF SOME CLOUDS
INCREASING LATE AS THE RIDGE AXIS APPROACHES. 925MB TEMPS IN THE 0-
2C RANGE AT 18Z WED SUPPORTS HIGHS IN THE 30S TO A COUPLE
40S...WARMEST IN SOUTHWEST WI.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 321 PM CST TUE FEB 18 2014
...WINTER STORM FOR WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...
MANY FACETS OF THE STORM TO TALK ABOUT...
MODEL ANALYSIS...18.12Z GUIDANCE CONTINUES TO FOLLOW THE PAST COUPLE
OF CYCLES...PHASING TROUGHING OVER THE ROCKIES ON TOP OF THE
FORECAST AREA THURSDAY. THE PHASED UPPER TROUGH ALSO BECOMES
NEGATIVELY TITLED AS IT LIFTS THROUGH THE FORECAST AREA THURSDAY
EVENING. OVERALL...THE SPREAD IN GUIDANCE FROM 500MB TO THE SURFACE
IS FAIRLY LOW CONSIDERING THIS IS A PHASING TROUGH AND STILL ISNT
ONSHORE YET. THEREFORE...CONFIDENCE IS INCREASING THAT A HIGH IMPACT
WINTER STORM WILL AFFECT THE FORECAST AREA.
WINDS...MOST OF THE GUIDANCE IS IN AGREEMENT THAT AS THE PHASING
TAKES PLACE OF THE UPPER TROUGH...THE SURFACE LOW IS GOING TO
UNDERGO BOMBOGENESIS...DROPPING FROM A PRESSURE OF 995MB IN EASTERN
KS AT 12Z THU TO AROUND 970MB OVER LAKE SUPERIOR AT 12Z FRI. TO
HANDLE THIS PRESSURE DROP AND THE COLD AIR THAT GETS PULLED
IN...925MB WINDS INCREASE OUT OF THE WEST-NORTHWEST AT 30-50 KT ON
THE BACK SIDE OF THE STORM FOR THURSDAY EVENING. THE STRONGEST CORE
TRACKS ACROSS SOUTHEAST MN AND NORTHEAST IOWA...THE FAVORABLE
BLIZZARD AREA.
PRECIPITATION...THERE IS SOME UNCERTAINTY ON HOW QUICK PRECIPITATION
DEVELOPS. GFS/NAM/ECMWF SOUNDINGS DEPICT A DECENT DRY LAYER BETWEEN
900-700MB WEDNESDAY NIGHT...WITH MUCH OF THE LIFT FROM WARM
ADVECTION IN THAT LAYER VERSUS IN THE MID/HIGH CLOUDS ABOVE IT.
PRECIPITATION SHOULD STAND A MUCH BETTER CHANCE MOVING IN
THURSDAY...LIKELY SOUTH TO NORTH...AS THE STORM SYSTEM MOVES INTO
SOUTHERN WI. DURING THE AFTERNOON...FRONTOGENESIS IN THE MID/UPPER
LEVELS REALLY INTENSIFIES WITH THE APPROACH OF THE UPPER TROUGH...
WHICH SHOULD DEVELOP A STRONG AND HEAVY PRECIPITATING COLD CONVEYOR
BELT. PRECIPITABLE WATER PROGGED BETWEEN 0.5-0.75 INCHES OR 200-250
PERCENT OF NORMAL SUGGESTS PLENTY OF MOISTURE AVAILABLE FOR THE
FORCING TO PRODUCE FAIRLY HEAVY QPF. CROSS-SECTIONS EVEN SHOW A
LARGE AREA OF NEGATIVE EPV AND SOME WEAK CAPE IN THE AFTERNOON...
SUGGESTING THUNDER COULD OCCUR. WILL SEE IF THIS TRENDS HOLDS WITH
LATER MODELS. COLD CONVEYOR BELT WILL GRADUALLY LIFT INTO THE U.P.
OF MI THU NIGHT...GRADUALLY ENDING PRECIPITATION SOUTHWEST TO
NORTHEAST.
PRECIPITATION TYPE...A DRY WARM LAYER ALOFT SHOULD RESIDE OVER THE
FORECAST AREA WEDNESDAY NIGHT. AS THE PRECIPITATION SPREADS IN LATE
WEDNESDAY NIGHT/THURSDAY MORNING...THAT COULD FALL AS EITHER
SLEET...FREEZING RAIN OR RAIN UNTIL EVAPORATIVE COOLING SWITCHES IT
OVER TO SNOW. THE AFTERNOON IS TRICKY AND COMPLETELY DEPENDS ON THE
850MB LOW TRACK. AHEAD OF THE 850MB LOW...A WARM LAYER ALOFT AND AT
THE SURFACE WILL ADVECT NORTH...RESULTING IN A MIX OR COMPLETELY
SWITCHOVER TO RAIN. RIGHT NOW THIS SEEMS MOST PROBABLE TO OCCUR IN
FAR SOUTHEAST SECTIONS OF THE FORECAST AREA FROM 15-21Z THU. IF THE
LOW TRACKS FARTHER NORTHWEST LIKE THE 18.12Z UKMET...THEN RAIN COULD
FALL EVEN AT LA CROSSE. HOWEVER...THE UKMET IS A NORTHWEST OUTLIER.
SNOW AMOUNTS/ICE ACCUMULATION...ANY ICE ACCUMULATION LOOKS TO BE
LATE WEDNESDAY NIGHT FROM THE INITIAL WARM LAYER. EVEN SNOW AMOUNTS
REALLY DO NOT START TO PICK UP UNTIL LATE THURSDAY MORNING WHEN
HEAVIER PRECIPITATION BEGINS TO DEVELOP. DURING THURSDAY AFTERNOON
AND EVENING...1 TO 2 INCH PER HOUR RATES ARE POSSIBLE...ESPECIALLY
IF CONVECTION FORMS. PRESENTLY DEPICT 2 TO 10 INCHES FOR
TOTALS...HIGHEST IN NORTH CENTRAL WI WHERE THE LONGEST DURATION OF
SNOW IS EXPECTED. IMPORTANT...THESE AMOUNTS ARE SUBJECT TO
CHANGE...AS EVEN THE NEW 18.18Z NAM SUGGESTS OF A FOOT IN SOUTHEAST
MN.
...REST OF THE LONG TERM PERIOD...
AFTER THE WINTER STORM...THE WEATHER GETS QUIET. 18.12Z
ECMWF/CANADIAN/GFS AND ENSEMBLE DATA REMAIN CONSISTENT IN FORMING AN
OMEGA BLOCK FROM THE U.S. WEST COAST INTO ALASKA...RESULTING IN DEEP
TROUGHING OVER MUCH OF CANADA AND INTO THE UPPER MIDWEST. THIS
ALLOWS FOR A GRADUAL COOLING TREND FROM FRIDAY THROUGH NEXT
TUESDAY...AND ACCORDING TO THE CFS WOULD CONTINUE THROUGH THE REST
OF THE MONTH. WIND CHILLS THROUGH TUESDAY LOOK TO STAY JUST ABOVE
WIND CHILL ADVISORY CRITERIA...I.E. -20 F. DESPITE THE COOLING
TREND...THERE ARE NOT THAT MANY PRECIPITATING SYSTEMS TO DEAL WITH.
THERE ARE SOME HINTS OF A WEAK SHORTWAVE CROSSING THE SOUTHERN
PORTION OF THE FORECAST AREA FRIDAY NIGHT WITH SOME LIGHT SNOW.
LOOKING OUT TO MONDAY AND MONDAY NIGHT OUR SOUTHERN FORECAST AREA
COULD ALSO GET CLIPPED BY A MID LEVEL FRONTOGENESIS BAND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1113 PM CST TUE FEB 18 2014
BAND OF CLOUDS ASSOCIATED WITH A SHORT WAVE TROUGH MOVING ACROSS
THE REGION HAVE JUST ABOUT MOVED EAST OF BOTH TAF SITES. EXPECT
THAT KRST WILL BE CLEAR BY 06Z WITH JUST SOME SCATTERED CLOUDS
LEFT FOR KLSE. THE GRADIENT AHEAD OF THE AREA OF HIGH PRESSURE
CENTERED OVER NEBRASKA IS EXPECTED TO KEEP THE WINDS AROUND 10
KNOTS FOR MOST OF THE NIGHT. THIS SHOULD PRODUCE ENOUGH MIXING TO
KEEP ANY FOG FROM FORMING...BUT IF THE WINDS DROP OFF SOME TOWARD
SUNRISE AS SUGGESTED BY THE 19.00Z NAM...THEN SOME FOG COULD
QUICKLY FORM WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE FROM THE
SNOW MELT TODAY. THE AREA OF HIGH PRESSURE WILL MOVE INTO MISSOURI
OVERNIGHT AND THE INTO THE OHIO RIVER VALLEY WEDNESDAY. THIS WILL
ALLOW THE WINDS TO COME AROUND TO THE SOUTH WEDNESDAY AND INCREASE
TO OVER 10 KNOTS BY LATE AFTERNOON/EARLY EVENING FOR KRST. MID
LEVEL CLOUDS WILL ALSO OVER SPREAD THE AREA AHEAD OF THE THURSDAY
STORM SYSTEM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 3 AM TO 9 AM CST THURSDAY FOR
WIZ041>044-053>055-061.
WINTER STORM WARNING FROM 9 AM THURSDAY TO 6 AM CST FRIDAY FOR
WIZ017-029-032>034-041-042-053-054.
WINTER STORM WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY
NIGHT FOR WIZ043-044-055-061.
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...BAUMGARDT
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1114 PM CST TUE FEB 18 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 321 PM CST TUE FEB 18 2014
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED SHORTWAVE TROUGHS OVER MANITOBA AND OVER EASTERN
SOUTH DAKOTA INTO NEBRASKA...RIDGING OVER THE NORTHERN
ROCKIES...AND A POTENT UPPER TROUGH JUST OFF THE BRITISH COLUMBIA
AND PACIFIC NORTHWEST COASTS. THIS POTENT UPPER TROUGH IS THE
CULPRIT FOR OUR THURSDAY STORM. DPVA AND PACIFIC MOISTURE AHEAD OF
THE TWO SHORTWAVE TROUGHS HAVE BEEN SPREADING MID AND HIGH CLOUDS
ACROSS THE FORECAST AREA TODAY. THESE CLOUDS HAVE LIMITED SOME
INSULATION...BUT SOUTHWESTERLY 925-850MB FLOW AHEAD OF A COLD
FRONT MOVING INTO THE FORECAST AREA HELPED BOOST TEMPERATURES INTO
THE 30S TO MID 40S THIS AFTERNOON. OVER WESTERN IOWA WHERE NO SNOW
EXISTS...READINGS ARE IN THE 50S TO LOW 60S. IN THE WAKE OF THE
COLD FRONT...READINGS ARE STILL IN THE 30S AND 40S...PARTIALLY DUE
TO A BIT MORE SUN AND DOWNSLOPING FLOW OFF THE NORTHERN ROCKIES.
THE QUIET BEFORE THE STORM PHRASE WORKS PERFECTLY FOR THE SHORT
TERM. 18.12Z MODEL GUIDANCE DEPICT THE RIDGING OVER THE NORTHERN
ROCKIES MARCHING EASTWARD TO ABOUT OVER THE FORECAST AREA BY 00Z
THU...PUSHED BY THE POTENT NORTHEAST PACIFIC NORTHWEST TROUGH
PLOWING INTO THE ROCKIES. ON THE EAST SIDE OF THE UPPER RIDGE AXIS
THERE IS A WEAK SHORTWAVE AT 500MB SUGGESTED TO DROP SOUTHEAST
THROUGH THE FORECAST AREA LATE TONIGHT...BUT THIS FEATURE WILL COME
THROUGH DRY WITH BASICALLY NO CLOUD.
ONLY REAL ISSUE TO CONTEND WITH TONIGHT IS IF ANY FOG CAN FORM
RESULTING FROM MELTING SNOW. ALL MODELS KEEP A DECENT PRESSURE
GRADIENT IN PLACE TONIGHT WITH A SURFACE RIDGE AXIS ONLY REACHING
WESTERN MN BY 12Z WED. 925MB WINDS STAY UP 20-30 KT FOR MUCH OF THE
NIGHT IN THE WAKE OF THE COLD FRONTAL PASSAGE THIS EVENING.
THUS...THINK ANY FOG WOULD BE LIMITED TO PERHAPS THE TYPICAL COLD
SPOTS AND SOME SMALL VALLEYS.
PLENTY OF SUN LOOKS ON TAP FOR WEDNESDAY...OUTSIDE OF SOME CLOUDS
INCREASING LATE AS THE RIDGE AXIS APPROACHES. 925MB TEMPS IN THE 0-
2C RANGE AT 18Z WED SUPPORTS HIGHS IN THE 30S TO A COUPLE
40S...WARMEST IN SOUTHWEST WI.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 321 PM CST TUE FEB 18 2014
...WINTER STORM FOR WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...
MANY FACETS OF THE STORM TO TALK ABOUT...
MODEL ANALYSIS...18.12Z GUIDANCE CONTINUES TO FOLLOW THE PAST COUPLE
OF CYCLES...PHASING TROUGHING OVER THE ROCKIES ON TOP OF THE
FORECAST AREA THURSDAY. THE PHASED UPPER TROUGH ALSO BECOMES
NEGATIVELY TITLED AS IT LIFTS THROUGH THE FORECAST AREA THURSDAY
EVENING. OVERALL...THE SPREAD IN GUIDANCE FROM 500MB TO THE SURFACE
IS FAIRLY LOW CONSIDERING THIS IS A PHASING TROUGH AND STILL ISNT
ONSHORE YET. THEREFORE...CONFIDENCE IS INCREASING THAT A HIGH IMPACT
WINTER STORM WILL AFFECT THE FORECAST AREA.
WINDS...MOST OF THE GUIDANCE IS IN AGREEMENT THAT AS THE PHASING
TAKES PLACE OF THE UPPER TROUGH...THE SURFACE LOW IS GOING TO
UNDERGO BOMBOGENESIS...DROPPING FROM A PRESSURE OF 995MB IN EASTERN
KS AT 12Z THU TO AROUND 970MB OVER LAKE SUPERIOR AT 12Z FRI. TO
HANDLE THIS PRESSURE DROP AND THE COLD AIR THAT GETS PULLED
IN...925MB WINDS INCREASE OUT OF THE WEST-NORTHWEST AT 30-50 KT ON
THE BACK SIDE OF THE STORM FOR THURSDAY EVENING. THE STRONGEST CORE
TRACKS ACROSS SOUTHEAST MN AND NORTHEAST IOWA...THE FAVORABLE
BLIZZARD AREA.
PRECIPITATION...THERE IS SOME UNCERTAINTY ON HOW QUICK PRECIPITATION
DEVELOPS. GFS/NAM/ECMWF SOUNDINGS DEPICT A DECENT DRY LAYER BETWEEN
900-700MB WEDNESDAY NIGHT...WITH MUCH OF THE LIFT FROM WARM
ADVECTION IN THAT LAYER VERSUS IN THE MID/HIGH CLOUDS ABOVE IT.
PRECIPITATION SHOULD STAND A MUCH BETTER CHANCE MOVING IN
THURSDAY...LIKELY SOUTH TO NORTH...AS THE STORM SYSTEM MOVES INTO
SOUTHERN WI. DURING THE AFTERNOON...FRONTOGENESIS IN THE MID/UPPER
LEVELS REALLY INTENSIFIES WITH THE APPROACH OF THE UPPER TROUGH...
WHICH SHOULD DEVELOP A STRONG AND HEAVY PRECIPITATING COLD CONVEYOR
BELT. PRECIPITABLE WATER PROGGED BETWEEN 0.5-0.75 INCHES OR 200-250
PERCENT OF NORMAL SUGGESTS PLENTY OF MOISTURE AVAILABLE FOR THE
FORCING TO PRODUCE FAIRLY HEAVY QPF. CROSS-SECTIONS EVEN SHOW A
LARGE AREA OF NEGATIVE EPV AND SOME WEAK CAPE IN THE AFTERNOON...
SUGGESTING THUNDER COULD OCCUR. WILL SEE IF THIS TRENDS HOLDS WITH
LATER MODELS. COLD CONVEYOR BELT WILL GRADUALLY LIFT INTO THE U.P.
OF MI THU NIGHT...GRADUALLY ENDING PRECIPITATION SOUTHWEST TO
NORTHEAST.
PRECIPITATION TYPE...A DRY WARM LAYER ALOFT SHOULD RESIDE OVER THE
FORECAST AREA WEDNESDAY NIGHT. AS THE PRECIPITATION SPREADS IN LATE
WEDNESDAY NIGHT/THURSDAY MORNING...THAT COULD FALL AS EITHER
SLEET...FREEZING RAIN OR RAIN UNTIL EVAPORATIVE COOLING SWITCHES IT
OVER TO SNOW. THE AFTERNOON IS TRICKY AND COMPLETELY DEPENDS ON THE
850MB LOW TRACK. AHEAD OF THE 850MB LOW...A WARM LAYER ALOFT AND AT
THE SURFACE WILL ADVECT NORTH...RESULTING IN A MIX OR COMPLETELY
SWITCHOVER TO RAIN. RIGHT NOW THIS SEEMS MOST PROBABLE TO OCCUR IN
FAR SOUTHEAST SECTIONS OF THE FORECAST AREA FROM 15-21Z THU. IF THE
LOW TRACKS FARTHER NORTHWEST LIKE THE 18.12Z UKMET...THEN RAIN COULD
FALL EVEN AT LA CROSSE. HOWEVER...THE UKMET IS A NORTHWEST OUTLIER.
SNOW AMOUNTS/ICE ACCUMULATION...ANY ICE ACCUMULATION LOOKS TO BE
LATE WEDNESDAY NIGHT FROM THE INITIAL WARM LAYER. EVEN SNOW AMOUNTS
REALLY DO NOT START TO PICK UP UNTIL LATE THURSDAY MORNING WHEN
HEAVIER PRECIPITATION BEGINS TO DEVELOP. DURING THURSDAY AFTERNOON
AND EVENING...1 TO 2 INCH PER HOUR RATES ARE POSSIBLE...ESPECIALLY
IF CONVECTION FORMS. PRESENTLY DEPICT 2 TO 10 INCHES FOR
TOTALS...HIGHEST IN NORTH CENTRAL WI WHERE THE LONGEST DURATION OF
SNOW IS EXPECTED. IMPORTANT...THESE AMOUNTS ARE SUBJECT TO
CHANGE...AS EVEN THE NEW 18.18Z NAM SUGGESTS OF A FOOT IN SOUTHEAST
MN.
...REST OF THE LONG TERM PERIOD...
AFTER THE WINTER STORM...THE WEATHER GETS QUIET. 18.12Z
ECMWF/CANADIAN/GFS AND ENSEMBLE DATA REMAIN CONSISTENT IN FORMING AN
OMEGA BLOCK FROM THE U.S. WEST COAST INTO ALASKA...RESULTING IN DEEP
TROUGHING OVER MUCH OF CANADA AND INTO THE UPPER MIDWEST. THIS
ALLOWS FOR A GRADUAL COOLING TREND FROM FRIDAY THROUGH NEXT
TUESDAY...AND ACCORDING TO THE CFS WOULD CONTINUE THROUGH THE REST
OF THE MONTH. WIND CHILLS THROUGH TUESDAY LOOK TO STAY JUST ABOVE
WIND CHILL ADVISORY CRITERIA...I.E. -20 F. DESPITE THE COOLING
TREND...THERE ARE NOT THAT MANY PRECIPITATING SYSTEMS TO DEAL WITH.
THERE ARE SOME HINTS OF A WEAK SHORTWAVE CROSSING THE SOUTHERN
PORTION OF THE FORECAST AREA FRIDAY NIGHT WITH SOME LIGHT SNOW.
LOOKING OUT TO MONDAY AND MONDAY NIGHT OUR SOUTHERN FORECAST AREA
COULD ALSO GET CLIPPED BY A MID LEVEL FRONTOGENESIS BAND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1113 PM CST TUE FEB 18 2014
BAND OF CLOUDS ASSOCIATED WITH A SHORT WAVE TROUGH MOVING ACROSS
THE REGION HAVE JUST ABOUT MOVED EAST OF BOTH TAF SITES. EXPECT
THAT KRST WILL BE CLEAR BY 06Z WITH JUST SOME SCATTERED CLOUDS
LEFT FOR KLSE. THE GRADIENT AHEAD OF THE AREA OF HIGH PRESSURE
CENTERED OVER NEBRASKA IS EXPECTED TO KEEP THE WINDS AROUND 10
KNOTS FOR MOST OF THE NIGHT. THIS SHOULD PRODUCE ENOUGH MIXING TO
KEEP ANY FOG FROM FORMING...BUT IF THE WINDS DROP OFF SOME TOWARD
SUNRISE AS SUGGESTED BY THE 19.00Z NAM...THEN SOME FOG COULD
QUICKLY FORM WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE FROM THE
SNOW MELT TODAY. THE AREA OF HIGH PRESSURE WILL MOVE INTO MISSOURI
OVERNIGHT AND THE INTO THE OHIO RIVER VALLEY WEDNESDAY. THIS WILL
ALLOW THE WINDS TO COME AROUND TO THE SOUTH WEDNESDAY AND INCREASE
TO OVER 10 KNOTS BY LATE AFTERNOON/EARLY EVENING FOR KRST. MID
LEVEL CLOUDS WILL ALSO OVER SPREAD THE AREA AHEAD OF THE THURSDAY
STORM SYSTEM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER STORM WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY
NIGHT FOR WIZ017-029-032>034-041>044-053>055-061.
MN...BLIZZARD WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY NIGHT
FOR MNZ086-087-094-095.
WINTER STORM WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY
NIGHT FOR MNZ079-088-096.
IA...BLIZZARD WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY NIGHT
FOR IAZ008>010-018-019-029.
WINTER STORM WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY
NIGHT FOR IAZ011-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS ALBANY NY
956 AM EST WED FEB 19 2014
.SYNOPSIS...
ANOTHER FAST MOVING LOW PRESSURE SYSTEM WILL BRING A
PERIOD OF SNOW AND RAIN TO THE REGION THIS AFTERNOON AND EVENING.
MILDER AIR WILL THEN MOVE INTO THE REGION BY THE END OF THE
WEEK...ALONG WITH A CHANCE OF RAIN SHOWERS AS A STRONG COLD FRONT
APPROACHES FROM THE GREAT LAKES THURSDAY NIGHT AND FRIDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 945 AM...RADAR SHOWS PCPN ECHOES JUST ENTERING THE FAR WESTERN
AND SOUTHWESTERN PARTS OF THE FORECAST AREA...BUT WITH VERY DRY AIR
NEAR THE SURFACE...THE PCPN IS NOT LOKELY REACHING THE GROUND YET.
EXPECT THAT THE LOWER LEVELS WILL MOISTEN UP AND A PERIOD OF PCPN
WILL BE WIDESPREAD FOR A TIME ACROSS THE REGION THIS AFTERNOON.
MAINLY SNOW EXPECTED FOR MOST AREAS WITH RAIN MIXING IN OVER SOME
LOWER TERRAIN AREAS. HAVE ADJUSTED HOURLY TEMPS TO REFLECT CURRENT
CONDITIONS WHICH ARE HIGHLY VARIABLE BASED ON THE MESONET
OBSERVATIONS.
.PREVIOUS DISCUSSION...
AS OF 635 AM EST...HAVE RAISED SNOWFALL AMTS ACROSS THE LAKE
GEORGE/SARATOGA REGION...INTO THE BERKSHIRES AND SOUTHERN VT.
EXPECT 1-3 INCHES ACROSS THE LAKE GEORGE/SARATOGA REGION...AND 2-4
INCHES ACROSS SOUTHERN VT...AND ACROSS BERKSHIRE COUNTY. THIS WAS
BASED ON THE LATEST RAP13 AND HRRR...WHICH INDICATED A POSSIBLE
BURST OF CONVECTIVE PRECIPITATION BETWEEN 22Z-02Z ASSOCIATED WITH
THE PASSAGE OF THE UPPER TROUGH.
MEANWHILE...HIGH AND MID LEVEL CLOUDS ARE INCREASING ACROSS
THE REGION. TEMPS...WHICH INITIALLY DROPPED INTO THE SINGLE DIGITS
AND LOWER TEENS DUE TO SIGNIFICANT BOUNDARY LAYER DECOUPLING
ALONG WITH THE VERY DEEP SNOWCOVER...HAVE NOW STARTED TO RISE. WE
EXPECT MOST TEMPS TO RISE INTO THE TEENS TO LOWER 20S BY
SUNRISE...ALTHOUGH MAY STILL REMAIN IN THE LOWER TEENS ACROSS
PORTIONS OF THE UPPER HUDSON VALLEY.
OTHERWISE...WE HAVE A VERY CHALLENGING FORECAST AHEAD FOR
TODAY...AS A POTENT SHORTWAVE CURRENTLY CROSSING THE MIDWEST
TRANSLATES RAPIDLY EASTWARD. THIS FEATURE...IN COMBINATION WITH A
WEAKER LEAD UPPER LEVEL IMPULSE...HAS TRIGGERED CONSIDERABLE
ELEVATED CONVECTION ACROSS THE NORTHERN APPALACHIANS AND UPPER
OHIO VALLEY EARLY THIS MORNING. THE LATEST RAP13 AND HRRR INDICATE
THAT THE REMNANTS OF THIS CONVECTION SHOULD TRACK EAST
NORTHEAST...ACROSS MAINLY CENTRAL AND SOUTHERN PORTIONS OF THE
REGION THIS AFTERNOON. THUS...PRECIP WILL BE MOST FAVORED FOR THE
EASTERN CATSKILLS...NORTHEAST INTO THE CAPITAL
REGION...BERKSHIRES...MID HUDSON VALLEY AND NW CT...AND SOUTHERN
VT...WITH POTENTIALLY LESS TO THE N AND W. HOWEVER...SHOULD THIS
CONVECTION WEAKEN...IT IS POSSIBLE THAT BETTER MOISTURE TRANSPORT
COULD ALLOW FOR PRECIP TO DEVELOP FURTHER NORTHWARD.
FURTHER COMPLICATING THE FORECAST WILL BE THE EXPECTED THERMAL
PROFILES AS THE PRECIP OCCURS. FORECAST SOUNDINGS...ESP SOUTH OF
ALBANY...INDICATE AN ABOVE FREEZING LAYER DEVELOPING AROUND 925
MB. THIS...IN COMBINATION WITH SOME BOUNDARY LAYER WARMING...WOULD
PROMOTE RAIN. HOWEVER...WITH A BURST OF STRONG VERTICAL VELOCITY
AND WET BULB COOLING...THE LOW LEVELS SHOULD COOL SUFFICIENTLY TO
ALLOW FOR SNOW AFTER A PERIOD OF RAIN/SNOW MIX IN SOME VALLEY
AREAS. SO...ASSUMING WE GET INTO THE BETTER DYNAMICAL FORCING THIS
AFTERNOON...WE HAVE SIDED MORE WITH SNOW THAN RAIN FOR MOST AREAS.
THIS SHOULD GIVE MOST VALLEY AREAS FROM ALBANY SOUTHWARD AROUND
AN INCH OF SNOW...WITH 1-3 INCHES POSSIBLE ACROSS PORTIONS OF THE
LAKE GEORGE/SARATOGA REGION...AS WELL AS HIGHER ELEVATIONS
SURROUNDING THE HUDSON VALLEY...AND 2-4 INCHES ACROSS THE
BERKSHIRES AND SOUTHERN VT. AGAIN...THIS IS A VERY TRICKY
SITUATION...AND SHOULD ANY HEAVIER PRECIP LINGER OVER ANY ONE AREA
LONGER THAN EXPECTED...HIGHER SNOWFALL AMTS COULD OCCUR.
HAVE SIDED WITH...OR EVEN COOLER THAN THE COLDER MOS FOR TODAY/S
MAX TEMPS...WITH MID/UPPER 30S IN VALLEY AREAS FROM ALBANY
SOUTH...AND GENERALLY LOWER/MID 30S TO THE NORTH...WITH GENERALLY
20S TO LOWER 30S ACROSS HIGHER ELEVATIONS.
SOUTH TO SOUTHEAST WINDS WILL INCREASE THIS MORNING THROUGH EARLY
AFTERNOON...SIMILAR TO YESTERDAY...WITH SOME GUSTS POSSIBLY
REACHING UP TO 30-35 MPH ACROSS PORTIONS OF SW VT...THE
BERKSHIRES...AND TACONICS...AND POSSIBLY UP TO 25-30 MPH WITHIN
THE CAPITAL REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...AS THE MAIN SHORTWAVE TROUGH PASSES THROUGH...ANOTHER
BURST OF PRECIPITATION IS EXPECTED. THE PRECIP SHOULD BE MORE
SHOWERY IN NATURE. IN FACT...MODEL SOUNDINGS ACTUALLY INDICATE RATHER
STEEP LAPSE RATES IN THE 700-500 HPA LAYER...WITH THE LATEST RAP13
INDICATING AS STEEP AS 8-8.5 C/KM. THESE STEEP LAPSE RATES...COMBINED
WITH ASCENT FROM THE APPROACHING/PASSING SHORTWAVE TROUGH...COULD
EVEN ALLOW FOR SOME ISOLATED THUNDERSTORMS ACROSS THE
REGION...SOME OF WHICH COULD PRODUCE GRAUPEL/SMALL HAIL. IN THE
WAKE OF THE TROUGH PASSAGE...STRONG WEST/NORTHWEST WINDS WILL
LIKELY DEVELOP...WITH ENHANCED FLOW DOWN THE MOHAWK RIVER
VALLEY/CAPITAL REGION AND BERKSHIRES EXPECTED. THIS COULD ALLOW
FOR SOME GUSTS TO REACH 35-40 MPH AT TIMES LATER THIS EVENING
UNTIL SHORTLY AFTER MIDNIGHT. SKIES SHOULD INITIALLY REMAIN MOSTLY
CLOUDY...BUT AS STRONG SUBSIDENCE AND SOME DOWNSLOPING
OCCURS...SKIES SHOULD TREND TO MOSTLY CLEAR WELL AFTER MIDNIGHT.
TEMPS WILL BE TRICKY...AS THERE COULD BE A WINDOW OF RAPID
DECOUPLING RIGHT AROUND OR EVEN AFTER DAYBREAK. HOWEVER...WIND AND
SOME CLOUDS SHOULD KEEP THIS FROM OCCURRING FOR MOST OF THE NIGHT.
SO...ALTHOUGH HAVE SIDED WITH THE COOLER MOS...DID NOT GO MUCH
COOLER. STILL EXPECT WIDESPREAD TEENS AND 20S ACROSS THE REGION.
THURSDAY...HIGH PRESSURE RIDGE WILL TRANSLATE EAST ACROSS THE
REGION. SKIES SHOULD BE MOSTLY SUNNY IN THE MORNING...WITH CLOUDS
INCREASING IN THE AFTERNOON. SOME LIGHT PRECIPITATION COULD REACH
FAR WESTERN AREAS TOWARD OR JUST AFTER SUNSET...MAINLY AS
RAIN...ALTHOUGH A RAIN/SLEET/SNOW MIX COULD OCCUR IN HIGHER
ELEVATIONS. EXPECT MAX TEMPS TO REACH THE UPPER 30S TO LOWER 40S
IN MOST VALLEY AREAS...AND LOWER/MID 30S FOR HIGHER ELEVATIONS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS POTENT STORM WRAPS UP ACROSS THE CENTRAL GREAT LAKES
REGION...EQUALLY IMPRESSIVE LOW LEVEL JET AND ISENTROPIC LIFT WILL
UNFOLD ACROSS UPSTATE NEW YORK THURSDAY NIGHT. THIS WILL ALLOW FOR
BANDS OF PRECIPITATION TO EVOLVE FROM SOUTH TO NORTH WITH THE PEAK
OF THE LOW LEVEL FORCING TAKING PLACE ACROSS THE ADIRONDACKS.
THERMAL PROFILES ACROSS THE REGION WILL BE TRANSITIONING WITHIN THE
WARM ADVECTION AS BOUNDARY LAYER TEMPS MAY STRUGGLE FOR A PERIOD OF
TIME. THIS SETS THE STAGE FOR SNOW MIXING WITH SLEET/FREEZING RAIN
IMPACTING MAINLY THE ADIRONDACKS AND SOUTHERN
GREENS...ALTHOUGH...COULD NOT RULE OUT SOME ISOLATED SHELTERED
LOCATIONS RECEIVING A WINTRY MIX IN THE MOHAWK AND CENTRAL-NORTHERN
HUDSON RIVER VALLEY. HOWEVER...THE STRENGTH OF THE WARM ADVECTION
WILL EVENTUALLY OVERCOME THE SHALLOW SUB FREEZING TEMPERATURES
FRIDAY MORNING FOR ALL OF THE PRECIPITATION TO BECOME RAIN.
ALONG WITH THE TEMPERATURES INCREASING...SO DOES THE DEWPOINT TO
ABOVE FREEZING. AS THIS WARMER AND MORE MOIST AIR ADVECTS OVER A
SNOW COVERED GROUND WOULD RESULT IN FOG AS WE WILL PLACE THIS IN THE
GRIDS. STRONG COLD FRONT WITH A FAIRLY TIGHT THERMAL GRADIENT FROM
+8C AT H850 OVER EASTERN NY TO -6C OVER WESTERN NY WILL QUICKLY MOVE
ACROSS THE REGION BY EARLY AFTERNOON PER THE LATEST NCEP MODEL SUITE
TIMING. AN INTERESTING NOTE HERE IS THE SHOWALTER VALUES FROM LATE
MORNING TO EARLY AFTERNOON DROP TO AROUND 0C WHICH SUGGESTS THE
WINDOW OF OPPORTUNITY FOR THUNDER. HOWEVER...WE WILL HOLD OFF ON
THE MENTION IN THE FORECAST/GRIDS UNTIL UPSTREAM TRENDS CAN BE
BETTER OBTAINED.
OVERALL...TEMPERATURES DURING THIS TIME FRAME WILL BE MAINLY
NON-DIURNAL DUE TO THE WARM ADVECTION THURSDAY NIGHT AND CONTINUING
TO RISE THROUGH FRIDAY.
THE LONG TERM WILL FEATURE A RETURN BACK TO WINTER TEMPERATURES AND
A VERY ACTIVE/FAST CYCLONIC FLOW ACROSS THE NORTHEAST CORRIDOR.
THE STORM THAT DEVELOPS OVER THE GREAT LAKES REGION SLOWLY FILLS AND
TRANSITIONS INTO A HUDSON/JAMES BAY LOW. WE WILL BE ON THE SOUTHERN
PERIPHERY OF THIS LOW WHICH KEEPS US RATHER UNSETTLED AND NEAR TO
BELOW NORMAL TEMPERATURES. THE TIMING OF SHORT WAVES WILL BE A
CHALLENGE IN THESE FAST FLOW REGIMES. PER THE GLOBAL MODELS...THE
FIRST WAVE ARRIVES SATURDAY WITH MAINLY THE EASTERN GREAT LAKES AND
SOME LAKE EFFECT SNOW IMPACTING PORTIONS OF THE ADIRONDACKS. THE
NEXT WAVE ARRIVES SUNDAY WITH A BIT MORE OF A SOUTHERN ROUTE. THIS
WAVE ATTEMPTS TO BE AN OVERACHIEVER PER THE ECMWF WITH THE GFS/GGEM
MUCH FLATTER AND MORE PROGRESSIVE. GIVEN THE RECENT TRACK RECORD OF
THE ECMWF...WE WILL PLACE SLIGHT CHANCE POPS FOR NOW.
LOOKING AHEAD INTO THE NEW WORK WEEK...THE HUDSON/JAMES BAY UPPER
LOW LOSES ITS GRIP AS WE MONITOR A POTENT PIECE OF ENERGY DIVE
SOUTHWARD FROM THE NORTHWEST TERRITORIES INTO THE INTERMOUNTAIN
WEST AND QUICKLY OUT ONTO THE CENTRAL PLAINS AND MID WEST BY
TUESDAY. THIS WILL REINTRODUCE THE CHANCE FOR ADDITIONAL WINTRY
PRECIPITATION LATE MONDAY INTO TUESDAY FOR THE ENTIRE CWFA.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
RATHER CHALLENGING IN THE NEAR TERM AS CLEAR SKIES WITH LIGHT WINDS
AND SNOW FROM EARLIER HAS RESULTED IN MVFR/IFR CONDITIONS AT KGFL
WITH OTHER TAF SITES HINTING AT THE POSSIBILITY. WE WILL PLACE A
TEMPO GROUP AT THIS TIME...AS WE MONITOR TRENDS AND UPSTREAM HIGH
AND MID LEVEL CLOUD COVER ADVECTING INTO THE REGION. THIS SHOULD
MINIMIZE THE FOG FROM SPREADING BUT IT WILL BE CLOSE.
AFTER SUNRISE...VISIBILITIES SHOULD IMPROVE AS WE WATCH THE NEXT
CLIPPER SYSTEM APPROACHING. THIS IS EXPECTED TO BRING ANOTHER
CHANCE FOR PRECIPITATION LATE THIS MORNING INTO THE AFTERNOON
HOURS. BOUNDARY LAYER TEMPERATURES WILL BE CLOSE TO RESULT IN
EITHER SN/RASN/RA. FOR NOW...WE FEEL KGFL WILL BE MAINLY SNOW WITH
A MIXTURE FURTHER SOUTH INTO KALB-KPSF AND TRANSITIONING TO ALL RAIN
KPOU. PRECIP SHOULD END THIS EVENING FROM WEST TO EAST RATHER
QUICKLY.
VARIABLE WINDS AT LESS THAN 6 KT WILL SWITCH TO A W-NW DIRECTION
BUT SWITCH TO A SOUTHERLY DIRECTION AND INCREASE TO AROUND 10 KTS
FOR WEDNESDAY MORNING...AND CONTINUE INTO THE AFTERNOON.
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.
&&
.HYDROLOGY...
SNOW DEPTHS ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN NEW
ENGLAND ARE GENERALLY FROM A FOOT TO THREE FEET. ALTHOUGH WE HAVE
WARMER TEMPERATURES IN THE FORECAST FOR THE LATTER PART OF THE
WEEK...EXCEPT FOR THURSDAY NIGHT...OVERNIGHT LOWS WILL BE AROUND OR
SLIGHTLY BELOW FREEZING WHICH SHOULD RESULT IN A SLOW MELT AND
HOPEFULLY MINIMIZE ANY FLOOD THREAT. RAINFALL TOTALS THURSDAY NIGHT
INTO FRIDAY MORNING ARE FORECAST TO GENERALLY BE IN THE QUARTER TO
HALF INCH RANGE...SO MUCH OF THIS RAINFALL SHOULD BE ABSORBED BY THE
CURRENT SNOWPACK.
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 25.7 INCHES THROUGH THE 16TH. THIS AMOUNT IS ONLY 0.3
INCHES FROM REACHING INTO THE TOP 10 FOR SNOWIEST FEBRUARYS SINCE
1885.
A LIGHT TO MODERATE SNOWFALL IS EXPECTED TUESDAY.
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. 27.5 INCHES 1899
8. 26.1 INCHES 1914
9. 26.0 INCHES 1958
10. 26.0 INCHES 1988
LOOKING AT THE SEASONAL SNOWFALL IT STANDS AT 62.8 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...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...KL/GJM
NEAR TERM...GJM/KL
SHORT TERM...KL
LONG TERM...BGM
AVIATION...BGM/NAS
HYDROLOGY...KL/GJM
CLIMATE...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
952 AM EST WED FEB 19 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION THIS AFTERNOON. HIGH
PRESSURE BUILDS IN TONIGHT THROUGH THURSDAY. A FRONTAL SYSTEM
MOVES THROUGH THE REGION LATE THURSDAY NIGHT AND FRIDAY. WEAK HIGH
PRESSURE BUILDS IN SATURDAY. A COLD FRONT MOVES THROUGH SUNDAY.
COLD CANADIAN HIGH PRESSURE BUILDS FOR MONDAY. A WEAK LOW MOVES
ACROSS THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST ON TRACK. PCPN MOVING TO WESTERN NJ ATTM. EXPECT RAIN IN
THE NY METRO FOR THE LUNCH HOUR. FREEZING RAIN FOR THE WESTERN
AREAS AS TEMPS ARE STILL IN THE 20S...BUT RISING QUICKLY.
IMPORTANT TO CONVEY IS THAT EVEN AS TEMPS WARM ABOVE
FREEZING...SURFAVE/PAVEMENT TEMPS WILL LAG BEHIND (LOWS WERE IN
THE SINGLE DIGITS AND TEENS JUST A FEW HOURS AGO). THUS...ICING
CONCERNS HERE ARE SIGNIFICANT...ESPECIALLY ON UNTREATED WALKWAYS.
OTHER CONCERN IS THE CONVECTION...LIGHTNING IS BEING OBSERVED
SOUTH AND WEST OF KPHL ATTM. EXAMINATION OF RAP SOUNDING SUGGEST
ONLY LIMITED ELEVATED INSTABILITY...SO WILL NOT INCLUDE IN FCST UP
HERE.
LASTLY...LATEST RAP RUN SUGGESTS THAT RA/SN SHOWER POTENTIAL IN WAKE
OF THE FRONT EARLY THIS EVENING. WILL EVACUATE THAT FOR THE NOON
UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
FOR TONIGHT...HIGH PRESSURE BUILDING IN FROM THE WEST AND OVERALL
JET STREAM LIFTING NORTH OF THE REGION...A MODERATION OF THE
AIRMASS WILL CONTINUE. STRONG RIDGING ALOFT WITH HIGH PRESSURE
BUILDING IN WILL PROVIDE STRONG SUBSIDENCE. THIS WILL ALLOW FOR
CLOUDS TO DECREASE RAPIDLY LATE.
LOWS WERE A BLEND OF MET/MAV/GMOS AND LOWERED A DEGREE IN SOME SPOTS
TO ACCOUNT FOR SOME RADIATIONAL COOLING. THIS WILL BE MORE
PRONOUNCED WHERE THERE IS MORE RESIDUAL SNOW PACK AND LIGHTER
WINDS...ACROSS THE INTERIOR.
FOR THURSDAY...THE HIGH PRESSURE AREA QUICKLY MOVES AND BUILDS
OFFSHORE WITH A CONTINUED WARM AIR ADVECTION FROM SOUTHERLY FLOW.
IN ADDITION...MID AND HIGH LEVEL CLOUDS WILL STREAM IN AHEAD OF
THE NEXT FRONTAL SYSTEM IN THE AFTERNOON WITH POSSIBLE SHOWERS
DEVELOPING LATE WITH THE APPROACH OF THE WARM FRONT. THE JET
STREAM CONTINUES TO PUSH NORTH AS THE AIRMASS CONTINUES TO
MODERATE.
HIGHS THURSDAY WERE A BLEND OF ECE/GMOS SUBTRACTED BY A DEGREE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A WARM FRONT APPROACHES THE AREA THURSDAY NIGHT AS SURFACE LOW
PRESSURE MOVES THROUGH THE GREAT LAKES. WITH THE LOW WELL TO THE
WEST AND THE COLD FRONT QUICKLY APPROACHING FROM THE WEST THE WARM
FRONT MAY NOT MOVE THROUGH THURSDAY NIGHT INTO FRIDAY MORNING.
LEANED TOWARD THE SLIGHTLY SLOWER COLD FRONT TIMING OF THE GFS AND
ECMWF...MOVING THROUGH FRIDAY AFTERNOON.
INCREASING ISENTROPIC LIFT WILL RESULT IN WARM ADVECTION LIGHT RAIN.
MID LEVELS STILL FORECAST TO DRY SO HAVE MAINTAINED THE DRIZZLE
THURSDAY NIGHT INTO FRIDAY MORNING...AND WITH THE SURFACE WARM FRONT
IN THE VICINITY KEPT AREAS OF FOG.
INSTABILITY INCREASES AHEAD OF THE COLD FRONT FRIDAY...MAINLY
ELEVATED...AND AN 60KT TO 70KT 850MB JET WILL MOVE THROUGH AHEAD OF
THE COLD FRONT...AIDING IN THE INSTABILITY AND CHANCES OF
CONVECTION.
WEAK RIDGE BUILDS IN BEHIND THE FRONT FOR FRIDAY NIGHT INTO
SATURDAY. THE UPPER AND SURFACE LOWS REMAIN ACROSS EASTERN CANADA
AND ANOTHER SHORTWAVE ROTATING THROUGH WILL BRING ANOTHER COLD FRONT
THROUGH THE REGION SUNDAY. WITH LITTLE MOISTURE HAVE KEPT MUCH OF
THE AREA DRY...WITH A CHANCE OF SNOW SHOWERS ACROSS THE INLAND
HIGHER TERRAIN. FLURRIES POSSIBLE FARTHER SOUTH AND EAST BUT NOT
CONFIDENT OF THIS AT THIS TIME. THE COLD FRONTAL PASSAGE SUNDAY AND
CANADIAN HIGH PRESSURE BUILDING IN WILL BRING AN END TO THE WARM
WEATHER..RETURNING TEMPERATURES TO BELOW NORMAL.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
A FRONTAL SYSTEM LIFTS THROUGH THE TERMINALS THIS AFTERNOON. NO
SIGNIFICANT CHANGES MADE TO THE PREVIOUS TAF PACKAGE...BUT LOWER
CIGS MAY ARRIVE AN HOUR OR SO EARLIER THAN FORECAST. THERE ARE
SOME LIGHTNING STRIKES ACROSS SE PA AND THE MID-ATLANTIC REGION.
LOW CONFIDENCE IF LIGHTNING WILL IMPACT KNYC TERMINALS...BUT IT IS
POSSIBLE A STRIKE OR 2 COULD WORK THEIR WAY UP THE COAST.
PTYPE RAIN...EXCEPT FOR KSWF...WHERE A BRIEF PERIOD OF -FZRASN IS
POSSIBLE AT ONSET. TEMPS SHOULD WARM UP QUICKLY ENOUGH FOR ONLY
ABOUT AN HOUR OR TWO OF FROZEN/FREEZING PRECIP.
PATCHY BR ACROSS KHPN...KISP...KGON...AND KBDR EARLY THIS
MORNING...WITH MVFR CONDITIONS POSSIBLE. MORE NOTICEABLE DROP IN
VSBYS LATER TODAY WITH GROUND FOG. CITY TERMINALS HAVE A BETTER
CHANCE OF IFR/LIFR...WITH A LOW TO MEDIUM CHANCE OF SEEING VLIFR.
TIMING FOR FOG...17Z AND 21Z. VSBY IMPROVES AFTER 21Z...WITH CIGS
IMPROVING IN THE EVENING.
LIGHT AND VARIABLE WINDS. SE WINDS INCREASE WED MORNING...WITH
OCCASIONAL GUSTS TO 25 KT ACROSS COASTAL TERMINALS. A PERIOD OF
LIGHT AND VARIABLE WINDS POSSIBLE IN THE AFTERNOON AS SURFACE LOW
WORKS ACROSS...BEFORE WINDS BECOME W AND INCREASE IN THE LATE
AFTERNOON. THEN GUSTY W WINDS TO 20-25KT AFTER 00Z.
MARGINAL LLWS ACROSS CITY/COASTAL TERMINALS BETWEEN 14Z AND 20Z
WITH 40-45KT 2 KFT SOUTHERLY JET.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED INTO THIS AFTERNOON
FOR IFR/LIFR VSBY. LOW TO MEDIUM CHANCE OF VLIFR. STILL SOME
UNCERTAINTY...BUT CONFIDENCE IS INCREASING THAT VSBYS COME DOWN TO
LESS THAN 1 MILE. TIMING OF ONSET 17-19Z.
KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED INTO THIS AFTERNOON
FOR IFR/LIFR VSBY. LOW TO MEDIUM CHANCE OF VLIFR. STILL SOME
UNCERTAINTY...BUT CONFIDENCE IS INCREASING THAT VSBYS COME DOWN TO
LESS THAN 1 MILE. TIMING OF ONSET 17-19Z.
KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED THIS AFTERNOON FOR
IFR/LIFR VSBY. LOW TO MEDIUM CHANCE OF VLIFR. STILL SOME
UNCERTAINTY...BUT CONFIDENCE IS INCREASING THAT VSBYS COME DOWN TO
LESS THAN 1 MILE. TIMING OF ONSET 17-19Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 4-6SM OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED THIS AFTERNOON FOR
IFR/LIFR VSBY. LOW TO MEDIUM CHANCE OF VLIFR. STILL SOME
UNCERTAINTY...BUT CONFIDENCE IS INCREASING THAT VSBYS COME DOWN TO
LESS THAN 1 MILE. TIMING OF ONSET 17-19Z.
KHPN FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED THIS AFTERNOON FOR
IFR/LIFR VSBY. LOW TO MEDIUM CHANCE OF VLIFR. STILL SOME
UNCERTAINTY...BUT CONFIDENCE IS INCREASING THAT VSBYS COME DOWN TO
LESS THAN 1 MILE. TIMING OF ONSET 17-19Z.
KISP FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED THIS AFTERNOON FOR
IFR/LIFR VSBY. LOW TO MEDIUM CHANCE OF VLIFR. STILL SOME
UNCERTAINTY...BUT CONFIDENCE IS INCREASING THAT VSBYS COME DOWN TO
LESS THAN 1 MILE. TIMING OF ONSET 16-18Z.
.OUTLOOK FOR 15Z THU THROUGH SUN...
.THU-THU EVENING...VFR.
.LATE THU NIGHT-FRI...MVFR OR LOWER CONDITIONS AND LLWS LIKELY IN
RAIN. A TSTM POSSIBLE. LATE DAY OR EVENING COLD FROPA.
.FRI NIGHT-SAT...VFR. W WINDS G20-25KT.
.SUN...VFR.
&&
.MARINE...
SCA CONTINUES ON THE OCEAN THROUGH THURSDAY MORNING EAST OF FIRE
ISLAND INLET. OTHERWISE...SCA ON OCEAN WEST OF FIRE ISLAND INLET
THROUGH TONIGHT. MAINLY SUB SCA CONDITIONS ON OTHER WATERS BUT
OCCASIONAL 25 KT GUSTS CANNOT BE RULED OUT TODAY.
SMALL CRAFT SEAS ON THE OCEAN WATERS WILL BE LIKELY THURSDAY NIGHT
INTO FRIDAY AS A SOUTHERLY FLOW INCREASES AHEAD OF A COLD FRONT.
SOUTHERLY WIND SPEEDS AND GUSTS MAY INCREASE TO NEAR SMALL CRAFT
LEVELS LATE THURSDAY NIGHT INTO FRIDAY MORNING. WITH A COLD FRONTAL
PASSAGE FRIDAY AFTERNOON THE WIND SHIFTS TO THE WEST AND DIMINISHES.
SEAS ON THE OCEAN REMAIN AT SMALL CRAFT LEVELS INTO SATURDAY
EVENING.
WIND GUSTS ON THE OCEAN MAY ONCE AGAIN INCREASE TO NEAR SMALL CRAFT
LEVELS SUNDAY NIGHT BEHIND A COLD FRONT MOVING THROUGH THE WATERS
SUNDAY.
&&
.HYDROLOGY...
RAINFALL AMOUNTS OF AROUND A QUARTER TO A THIRD OF AN INCH IS
EXPECTED DURING THE DAY TODAY WITH THE COLD FRONT.
A QUARTER TO HALF INCH OF RAINFALL IS LIKELY THURSDAY NIGHT INTO
FRIDAY.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY
BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER
RADIO STATION KWO35 IS OUT OF SERVICE.
DURING THE TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TEST OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ067-069.
NJ...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NJZ002-004-103-
105-107.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST THURSDAY FOR ANZ355.
SMALL CRAFT ADVISORY UNTIL NOON EST THURSDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...JM/MET
NEAR TERM...TONGUE
SHORT TERM...JM
LONG TERM...MET
AVIATION...MPS
MARINE...JM/MET
HYDROLOGY...JM/MET
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
714 AM EST WED FEB 19 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION THIS AFTERNOON. HIGH PRESSURE
FROM THE SOUTH AND WEST BUILDS IN TONIGHT AND BUILDS OFFSHORE ON
THURSDAY. A FRONTAL SYSTEM MOVES THROUGH THE REGION THURSDAY NIGHT
AND FRIDAY. WEAK HIGH PRESSURE BUILDS IN SATURDAY. A COLD FRONT
MOVES THROUGH SUNDAY. CANADIAN HIGH PRESSURE BUILDS FOR MONDAY. A
WEAK LOW MOVES ACROSS THE AREA TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THERE ARE STILL SOME AREAS OF BLACK ICE FROM REFREEZING OF MELTED
SNOW THE PREVIOUS DAY. SPS REGARDING THIS REMAINS IN EFFECT
THROUGH EARLY MORNING.
FORECAST MAINLY ON TRACK. PRECIP DEVELOPING IN WESTERN PA...WITH
CURRENT LINEAR TRACKING WILL BE MOVING INTO WESTERN PORTIONS OF
THE REGION AROUND 16-17Z. FREEZING RAIN STILL LOOKS TO BE MAIN PRECIP
TYPE ACROSS PARTS OF INTERIOR AS 925 AND 850MB TEMPS HAVE RISEN A
FEW DEGREES ABOVE FREEZING ACCORDING TO RUC13 ANALYSIS. AFTER
17Z...COASTAL LOCATIONS SHOULD ALREADY BE WELL ABOVE FREEZING WITH
INTERIOR SECTIONS ALSO RISING ABOVE FREEZING BY THAT TIME.
FOR TODAY...MAIN FOCUS IS THE PRECIPITATION ASSOCIATED WITH THE
COLD FRONT AND ITS TIMING. THIS IS NOT A SIGNIFICANT SYSTEM WITH
RATHER WEAK MAGNITUDES OF THE PARENT LOW PRESSURE AND THAT OF THE
COLD FRONT.
THERE IS ENOUGH CONFIDENCE FOR THE LIKELIHOOD OF MEASURABLE
PRECIPITATION BUT THE MAGNITUDE OF THE 850-700MB FRONTOGENESIS IS
NOT LARGE. HOWEVER...THERE IS ENOUGH OF A COHERENT SIGNAL OF THIS
FRONTOGENESIS AND AGREE TOO WITH LOW TO MID LEVEL WARM AIR
ADVECTION CONTRIBUTING TO THIS FRONTOGENESIS AMONGST THE NUMERICAL
WEATHER PREDICTION TO MODELS. THIS SUGGEST MAINTENANCE AND PERHAPS
EVEN SOME ENHANCEMENT TO PRECIP AS IT MOVES ACROSS THE AREA.
IN ADDITION...EVEN THOUGH AT FIRST GLANCE THE POPS ARE TRENDING
HIGHER THAN WHEN MOST MODELS SHOW PRECIP ARRIVING...WILL KEEP THIS
EARLIER TIMING SINCE PRECIP TYPICALLY DEVELOPS AND ARRIVES SOONER
THAN WHAT MODELS SHOW WITH THE WARM AIR ADVECTION ALOFT.
THEREFORE...EARLIER TIMING MEANS SURFACE TEMPERATURES FOR THE
INTERIOR WILL STILL BE AT FREEZING OR BELOW WHEN THE PRECIP
ARRIVES. THERE IS WARM ADVECTION ALOFT EVIDENT AT THE 850MB LEVEL.
THIS WILL LIKELY RACE AHEAD OF THE SURFACE WARMER AIR AND WITH THE
INTERIOR AREAS NEAR HIGHER TERRAIN AND WITH BLOCKAGE FROM
SOUTHERLY FLOW...THERE WILL BE LIKELY BE AREAS WHICH WILL BE COLD
ENOUGH FOR FREEZING RAIN.
ADDING TO THE UNCERTAINTY IS THE POTENTIAL FOR STRONGER VERTICAL
VELOCITY TO COOL THE COLUMN AND IN THIS CASE...SNOW SHOWERS WOULD BE
THE LIKELY RESULT. A COATING OF SNOW WILL BE POSSIBLE IN THIS
SCENARIO. BUT THINKING AT THE MOMENT FREEZING RAIN WILL BE THE MORE
LIKELY OF PRECIP TYPES FOR INTERIOR AREAS THIS MORNING. SO JUST
LEFT SNOW SHOWERS AS A CHANCE FOR THE MORNING.
THEREFORE KEEPING FREEZING RAIN ADVISORY AND HEADLINES AS THEY
WERE BEFORE. BY THE TIME THE LINE OF PRECIP ARRIVES TOWARDS
SOUTHERN CONNECTICUT...TEMPERATURES WILL LIKELY ALREADY BE ABOVE
FREEZING FOR MOST PLACES.
PATCHY FOG WILL BE SEEN AS WELL FOR THE AFTERNOON WITH MOIST INFLOW
FROM ONSHORE FLOW AHEAD OF THE COLD FRONT AND LINGERING MOISTURE
AFTER SHOWERS MOVE THROUGH.
HIGHS WERE A BLEND OF NAM12 AND COOLER MAV GUIDANCE YIELDING UPPER
30S TO LOWER 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
FOR TONIGHT...AT THE START OF THE EVENING...THERE WILL BE A
CHANCE FOR SOME LINGERING RAIN SHOWERS BEHIND THE COLD FRONT.
WINDS WILL BE TURNING MORE WESTERLY AND EVENTUALLY NORTHWESTERLY.
WITH HIGH PRESSURE BUILDING IN FROM THE WEST AND OVERALL JET STREAM
LIFTING NORTH OF THE REGION...A MODERATION OF THE AIRMASS WILL
CONTINUE. STRONG RIDGING ALOFT WITH HIGH PRESSURE BUILDING IN WILL
PROVIDE STRONG SUBSIDENCE. THIS WILL ALLOW FOR CLOUDS TO DECREASE
RAPIDLY LATE.
LOWS WERE A BLEND OF MET/MAV/GMOS AND LOWERED A DEGREE IN SOME SPOTS
TO ACCOUNT FOR SOME RADIATIONAL COOLING. THIS WILL BE MORE
PRONOUNCED WHERE THERE IS MORE RESIDUAL SNOW PACK AND LIGHTER
WINDS...ACROSS THE INTERIOR.
FOR THURSDAY...THE HIGH PRESSURE AREA QUICKLY MOVES AND BUILDS
OFFSHORE WITH A CONTINUED WARM AIR ADVECTION FROM SOUTHERLY FLOW.
IN ADDITION...MID AND HIGH LEVEL CLOUDS WILL STREAM IN AHEAD OF
THE NEXT FRONTAL SYSTEM IN THE AFTERNOON WITH POSSIBLE SHOWERS
DEVELOPING LATE WITH THE APPROACH OF THE WARM FRONT. THE JET
STREAM CONTINUES TO PUSH NORTH AS THE AIRMASS CONTINUES TO
MODERATE.
HIGHS THURSDAY WERE A BLEND OF ECE/GMOS SUBTRACTED BY A DEGREE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
A WARM FRONT APPROACHES THE AREA THURSDAY NIGHT AS SURFACE LOW
PRESSURE MOVES THROUGH THE GREAT LAKES. WITH THE LOW WELL TO THE
WEST AND THE COLD FRONT QUICKLY APPROACHING FROM THE WEST THE WARM
FRONT MAY NOT MOVE THROUGH THURSDAY NIGHT INTO FRIDAY MORNING.
LEANED TOWARD THE SLIGHTLY SLOWER COLD FRONT TIMING OF THE GFS AND
ECMWF...MOVING THROUGH FRIDAY AFTERNOON.
INCREASING ISENTROPIC LIFT WILL RESULT IN WARM ADVECTION LIGHT RAIN.
MID LEVELS STILL FORECAST TO DRY SO HAVE MAINTAINED THE DRIZZLE
THURSDAY NIGHT INTO FRIDAY MORNING...AND WITH THE SURFACE WARM FRONT
IN THE VICINITY KEPT AREAS OF FOG.
INSTABILITY INCREASES AHEAD OF THE COLD FRONT FRIDAY...MAINLY
ELEVATED...AND AN 60KT TO 70KT 850MB JET WILL MOVE THROUGH AHEAD OF
THE COLD FRONT...AIDING IN THE INSTABILITY AND CHANCES OF
CONVECTION.
WEAK RIDGE BUILDS IN BEHIND THE FRONT FOR FRIDAY NIGHT INTO
SATURDAY. THE UPPER AND SURFACE LOWS REMAIN ACROSS EASTERN CANADA
AND ANOTHER SHORTWAVE ROTATING THROUGH WILL BRING ANOTHER COLD FRONT
THROUGH THE REGION SUNDAY. WITH LITTLE MOISTURE HAVE KEPT MUCH OF
THE AREA DRY...WITH A CHANCE OF SNOW SHOWERS ACROSS THE INLAND
HIGHER TERRAIN. FLURRIES POSSIBLE FARTHER SOUTH AND EAST BUT NOT
CONFIDENT OF THIS AT THIS TIME. THE COLD FRONTAL PASSAGE SUNDAY AND
CANADIAN HIGH PRESSURE BUILDING IN WILL BRING AN END TO THE WARM
WEATHER..RETURNING TEMPERATURES TO BELOW NORMAL.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
FRONTAL SYSTEM APPROACHES THE TERMINALS THIS
MORNING AND CROSSES THE FORECAST AREA DURING THIS AFTERNOON. THIS
WILL ALLOW RAIN TO MOVE IN AFTER 16Z.
AT KSWF...SOME -FZRASN IS POSSIBLE AT ONSET. SURFACE TEMPS MAY TAKE
UNTIL...BUT TEMPS SHOULD WARM UP QUICKLY ENOUGH FOR ONLY ABOUT AN
HOUR OR TWO OF FROZEN/FREEZING PRECIP.
PATCHY BR ACROSS KHPN...KISP...KGON...AND KBDR EARLY THIS
MORNING...WITH MVFR CONDITIONS POSSIBLE. MORE NOTICEABLE DROP IN
VSBYS LATER TODAY WITH GROUND FOG. CITY TERMINALS HAVE A BETTER
CHANCE OF IFR/LIFR...WITH A LOW TO MEDIUM CHANCE OF SEEING VLIFR.
TIMING FOR FOG...17Z AND 21Z. VSBY IMPROVES AFTER 21Z...WITH CIGS
IMPROVING IN THE EVENING.
LIGHT AND VARIABLE WINDS. SE WINDS INCREASE WED MORNING...WITH
OCCASIONAL GUSTS TO 25 KT ACROSS COASTAL TERMINALS. A PERIOD OF
LIGHT AND VARIABLE WINDS POSSIBLE IN THE AFTERNOON AS SURFACE LOW
WORKS ACROSS...BEFORE WINDS BECOME W AND INCREASE IN THE LATE
AFTERNOON. THEN GUSTY W WINDS TO 20-25KT AFTER 00Z.
MARGINAL LLWS ACROSS CITY/COASTAL TERMINALS BETWEEN 14Z AND 20Z
WITH 40-45KT 2 KFT SOUTHERLY JET.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED THIS MORNING AND
AFTERNOON FOR IFR/LIFR VSBY. LOW TO MEDIUM CHANCE OF VLIFR. STILL
SOME UNCERTAINTY...BUT CONFIDENCE IS INCREASING THAT VSBYS COME DOWN
TO LESS THAN 1 MILE. TIMING OF ONSET 17-19Z.
KLGA FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED THIS MORNING AND
AFTERNOON FOR IFR/LIFR VSBY. LOW TO MEDIUM CHANCE OF VLIFR. STILL
SOME UNCERTAINTY...BUT CONFIDENCE IS INCREASING THAT VSBYS COME DOWN
TO LESS THAN 1 MILE. TIMING OF ONSET 17-19Z.
KEWR FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED WEDNESDAY MORNING AND
AFTERNOON FOR IFR/LIFR VSBY. LOW TO MEDIUM CHANCE OF VLIFR. STILL
SOME UNCERTAINTY...BUT CONFIDENCE IS INCREASING THAT VSBYS COME DOWN
TO LESS THAN 1 MILE. TIMING OF ONSET 17-19Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 4-6SM OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED WEDNESDAY MORNING AND
AFTERNOON FOR IFR/LIFR VSBY. LOW TO MEDIUM CHANCE OF VLIFR. STILL
SOME UNCERTAINTY...BUT CONFIDENCE IS INCREASING THAT VSBYS COME DOWN
TO LESS THAN 1 MILE. TIMING OF ONSET 17-19Z.
KHPN FCSTER COMMENTS: AMENDMENTS MAY BE NEEDED WEDNESDAY MORNING AND
AFTERNOON FOR IFR/LIFR VSBY. LOW TO MEDIUM CHANCE OF VLIFR. STILL
SOME UNCERTAINTY...BUT CONFIDENCE IS INCREASING THAT VSBYS COME DOWN
TO LESS THAN 1 MILE. TIMING OF ONSET 17-19Z.
KISP FCSTER COMMENTS: MVFR VSBY POSSIBLE THIS MORNING. AMENDMENTS
MAY BE NEEDED WEDNESDAY MORNING AND AFTERNOON FOR IFR/LIFR VSBY. LOW
TO MEDIUM CHANCE OF VLIFR. STILL SOME UNCERTAINTY...BUT CONFIDENCE
IS INCREASING THAT VSBYS COME DOWN TO LESS THAN 1 MILE. TIMING OF
ONSET 16-18Z.
.OUTLOOK FOR 00Z THU THROUGH SAT...
.LATE WED NIGHT...CONDITIONS IMPROVING TO VFR. W WINDS WITH G20-25KT
THROUGH AROUND 06Z.
.THU-THU EVENING...VFR.
.LATE THU NIGHT-FRI...MVFR OR LOWER CONDITIONS AND LLWS LIKELY IN
RAIN. A TSTM POSSIBLE. LATE DAY OR EVENING COLD FROPA.
.FRI NIGHT-SAT...VFR. W WINDS G20-25KT.
&&
.MARINE...
SCA CONTINUES ON THE OCEAN THROUGH THURSDAY MORNING EAST OF FIRE
ISLAND INLET. OTHERWISE...SCA ON OCEAN WEST OF FIRE ISLAND INLET
THROUGH TONIGHT. MAINLY SUB SCA CONDITIONS ON OTHER WATERS BUT
OCCASIONAL 25 KT GUSTS CANNOT BE RULED OUT TODAY.
SMALL CRAFT SEAS ON THE OCEAN WATERS WILL BE LIKELY THURSDAY NIGHT
INTO FRIDAY AS A SOUTHERLY FLOW INCREASES AHEAD OF A COLD FRONT.
SOUTHERLY WIND SPEEDS AND GUSTS MAY INCREASE TO NEAR SMALL CRAFT
LEVELS LATE THURSDAY NIGHT INTO FRIDAY MORNING. WITH A COLD FRONTAL
PASSAGE FRIDAY AFTERNOON THE WIND SHIFTS TO THE WEST AND DIMINISHES.
SEAS ON THE OCEAN REMAIN AT SMALL CRAFT LEVELS INTO SATURDAY
EVENING.
WIND GUSTS ON THE OCEAN MAY ONCE AGAIN INCREASE TO NEAR SMALL CRAFT
LEVELS SUNDAY NIGHT BEHIND A COLD FRONT MOVING THROUGH THE WATERS
SUNDAY.
&&
.HYDROLOGY...
RAINFALL AMOUNTS OF AROUND A QUARTER TO A THIRD OF AN INCH IS
EXPECTED DURING THE DAY TODAY WITH THE COLD FRONT.
A QUARTER TO HALF INCH OF RAINFALL IS LIKELY THURSDAY NIGHT INTO
FRIDAY.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY
BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER
RADIO STATION KWO35 IS OUT OF SERVICE.
DURING THE TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TEST OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ067-069.
NJ...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NJZ002-004-103-
105-107.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST THURSDAY FOR ANZ355.
SMALL CRAFT ADVISORY UNTIL NOON EST THURSDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...JM/MET
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MET
AVIATION...JP
MARINE...JM/MET
HYDROLOGY...JM/MET
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
645 AM EST WED FEB 19 2014
.SYNOPSIS...
ANOTHER FAST MOVING LOW PRESSURE SYSTEM WILL BRING A
PERIOD OF SNOW AND RAIN TO THE REGION THIS AFTERNOON AND EVENING.
MILDER AIR WILL THEN MOVE INTO THE REGION BY THE END OF THE
WEEK...ALONG WITH A CHANCE OF RAIN SHOWERS AS A STRONG COLD FRONT
APPROACHES FROM THE GREAT LAKES THURSDAY NIGHT AND FRIDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 635 AM EST...HAVE RAISED SNOWFALL AMTS ACROSS THE LAKE
GEORGE/SARATOGA REGION...INTO THE BERKSHIRES AND SOUTHERN VT.
EXPECT 1-3 INCHES ACROSS THE LAKE GEORGE/SARATOGA REGION...AND 2-4
INCHES ACROSS SOUTHERN VT...AND ACROSS BERKSHIRE COUNTY. THIS WAS
BASED ON THE LATEST RAP13 AND HRRR...WHICH INDICATED A POSSIBLE
BURST OF CONVECTIVE PRECIPITATION BETWEEN 22Z-02Z ASSOCIATED WITH
THE PASSAGE OF THE UPPER TROUGH.
MEANWHILE...HIGH AND MID LEVEL CLOUDS ARE INCREASING ACROSS
THE REGION. TEMPS...WHICH INITIALLY DROPPED INTO THE SINGLE DIGITS
AND LOWER TEENS DUE TO SIGNIFICANT BOUNDARY LAYER DECOUPLING
ALONG WITH THE VERY DEEP SNOWCOVER...HAVE NOW STARTED TO RISE. WE
EXPECT MOST TEMPS TO RISE INTO THE TEENS TO LOWER 20S BY
SUNRISE...ALTHOUGH MAY STILL REMAIN IN THE LOWER TEENS ACROSS
PORTIONS OF THE UPPER HUDSON VALLEY.
OTHERWISE...WE HAVE A VERY CHALLENGING FORECAST AHEAD FOR
TODAY...AS A POTENT SHORTWAVE CURRENTLY CROSSING THE MIDWEST
TRANSLATES RAPIDLY EASTWARD. THIS FEATURE...IN COMBINATION WITH A
WEAKER LEAD UPPER LEVEL IMPULSE...HAS TRIGGERED CONSIDERABLE
ELEVATED CONVECTION ACROSS THE NORTHERN APPALACHIANS AND UPPER
OHIO VALLEY EARLY THIS MORNING. THE LATEST RAP13 AND HRRR INDICATE
THAT THE REMNANTS OF THIS CONVECTION SHOULD TRACK EAST
NORTHEAST...ACROSS MAINLY CENTRAL AND SOUTHERN PORTIONS OF THE
REGION THIS AFTERNOON. THUS...PRECIP WILL BE MOST FAVORED FOR THE
EASTERN CATSKILLS...NORTHEAST INTO THE CAPITAL
REGION...BERKSHIRES...MID HUDSON VALLEY AND NW CT...AND SOUTHERN
VT...WITH POTENTIALLY LESS TO THE N AND W. HOWEVER...SHOULD THIS
CONVECTION WEAKEN...IT IS POSSIBLE THAT BETTER MOISTURE TRANSPORT
COULD ALLOW FOR PRECIP TO DEVELOP FURTHER NORTHWARD.
FURTHER COMPLICATING THE FORECAST WILL BE THE EXPECTED THERMAL
PROFILES AS THE PRECIP OCCURS. FORECAST SOUNDINGS...ESP SOUTH OF
ALBANY...INDICATE AN ABOVE FREEZING LAYER DEVELOPING AROUND 925
MB. THIS...IN COMBINATION WITH SOME BOUNDARY LAYER WARMING...WOULD
PROMOTE RAIN. HOWEVER...WITH A BURST OF STRONG VERTICAL VELOCITY
AND WET BULB COOLING...THE LOW LEVELS SHOULD COOL SUFFICIENTLY TO
ALLOW FOR SNOW AFTER A PERIOD OF RAIN/SNOW MIX IN SOME VALLEY
AREAS. SO...ASSUMING WE GET INTO THE BETTER DYNAMICAL FORCING THIS
AFTERNOON...WE HAVE SIDED MORE WITH SNOW THAN RAIN FOR MOST AREAS.
THIS SHOULD GIVE MOST VALLEY AREAS FROM ALBANY SOUTHWARD AROUND
AN INCH OF SNOW...WITH 1-3 INCHES POSSIBLE ACROSS PORTIONS OF THE
LAKE GEORGE/SARATOGA REGION...AS WELL AS HIGHER ELEVATIONS
SURROUNDING THE HUDSON VALLEY...AND 2-4 INCHES ACROSS THE
BERKSHIRES AND SOUTHERN VT. AGAIN...THIS IS A VERY TRICKY
SITUATION...AND SHOULD ANY HEAVIER PRECIP LINGER OVER ANY ONE AREA
LONGER THAN EXPECTED...HIGHER SNOWFALL AMTS COULD OCCUR.
HAVE SIDED WITH...OR EVEN COOLER THAN THE COLDER MOS FOR TODAY/S
MAX TEMPS...WITH MID/UPPER 30S IN VALLEY AREAS FROM ALBANY
SOUTH...AND GENERALLY LOWER/MID 30S TO THE NORTH...WITH GENERALLY
20S TO LOWER 30S ACROSS HIGHER ELEVATIONS.
SOUTH TO SOUTHEAST WINDS WILL INCREASE THIS MORNING THROUGH EARLY
AFTERNOON...SIMILAR TO YESTERDAY...WITH SOME GUSTS POSSIBLY
REACHING UP TO 30-35 MPH ACROSS PORTIONS OF SW VT...THE
BERKSHIRES...AND TACONICS...AND POSSIBLY UP TO 25-30 MPH WITHIN
THE CAPITAL REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...AS THE MAIN SHORTWAVE TROUGH PASSES THROUGH...ANOTHER
BURST OF PRECIPITATION IS EXPECTED. THE PRECIP SHOULD BE MORE
SHOWERY IN NATURE. IN FACT...MODEL SOUNDINGS ACTUALLY INDICATE RATHER
STEEP LAPSE RATES IN THE 700-500 HPA LAYER...WITH THE LATEST RAP13
INDICATING AS STEEP AS 8-8.5 C/KM. THESE STEEP LAPSE RATES...COMBINED
WITH ASCENT FROM THE APPROACHING/PASSING SHORTWAVE TROUGH...COULD
EVEN ALLOW FOR SOME ISOLATED THUNDERSTORMS ACROSS THE
REGION...SOME OF WHICH COULD PRODUCE GRAUPEL/SMALL HAIL. IN THE
WAKE OF THE TROUGH PASSAGE...STRONG WEST/NORTHWEST WINDS WILL
LIKELY DEVELOP...WITH ENHANCED FLOW DOWN THE MOHAWK RIVER
VALLEY/CAPITAL REGION AND BERKSHIRES EXPECTED. THIS COULD ALLOW
FOR SOME GUSTS TO REACH 35-40 MPH AT TIMES LATER THIS EVENING
UNTIL SHORTLY AFTER MIDNIGHT. SKIES SHOULD INITIALLY REMAIN MOSTLY
CLOUDY...BUT AS STRONG SUBSIDENCE AND SOME DOWNSLOPING
OCCURS...SKIES SHOULD TREND TO MOSTLY CLEAR WELL AFTER MIDNIGHT.
TEMPS WILL BE TRICKY...AS THERE COULD BE A WINDOW OF RAPID
DECOUPLING RIGHT AROUND OR EVEN AFTER DAYBREAK. HOWEVER...WIND AND
SOME CLOUDS SHOULD KEEP THIS FROM OCCURRING FOR MOST OF THE NIGHT.
SO...ALTHOUGH HAVE SIDED WITH THE COOLER MOS...DID NOT GO MUCH
COOLER. STILL EXPECT WIDESPREAD TEENS AND 20S ACROSS THE REGION.
THURSDAY...HIGH PRESSURE RIDGE WILL TRANSLATE EAST ACROSS THE
REGION. SKIES SHOULD BE MOSTLY SUNNY IN THE MORNING...WITH CLOUDS
INCREASING IN THE AFTERNOON. SOME LIGHT PRECIPITATION COULD REACH
FAR WESTERN AREAS TOWARD OR JUST AFTER SUNSET...MAINLY AS
RAIN...ALTHOUGH A RAIN/SLEET/SNOW MIX COULD OCCUR IN HIGHER
ELEVATIONS. EXPECT MAX TEMPS TO REACH THE UPPER 30S TO LOWER 40S
IN MOST VALLEY AREAS...AND LOWER/MID 30S FOR HIGHER ELEVATIONS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS POTENT STORM WRAPS UP ACROSS THE CENTRAL GREAT LAKES
REGION...EQUALLY IMPRESSIVE LOW LEVEL JET AND ISENTROPIC LIFT WILL
UNFOLD ACROSS UPSTATE NEW YORK THURSDAY NIGHT. THIS WILL ALLOW FOR
BANDS OF PRECIPITATION TO EVOLVE FROM SOUTH TO NORTH WITH THE PEAK
OF THE LOW LEVEL FORCING TAKING PLACE ACROSS THE ADIRONDACKS.
THERMAL PROFILES ACROSS THE REGION WILL BE TRANSITIONING WITHIN THE
WARM ADVECTION AS BOUNDARY LAYER TEMPS MAY STRUGGLE FOR A PERIOD OF
TIME. THIS SETS THE STAGE FOR SNOW MIXING WITH SLEET/FREEZING RAIN
IMPACTING MAINLY THE ADIRONDACKS AND SOUTHERN
GREENS...ALTHOUGH...COULD NOT RULE OUT SOME ISOLATED SHELTERED
LOCATIONS RECEIVING A WINTRY MIX IN THE MOHAWK AND CENTRAL-NORTHERN
HUDSON RIVER VALLEY. HOWEVER...THE STRENGTH OF THE WARM ADVECTION
WILL EVENTUALLY OVERCOME THE SHALLOW SUB FREEZING TEMPERATURES
FRIDAY MORNING FOR ALL OF THE PRECIPITATION TO BECOME RAIN.
ALONG WITH THE TEMPERATURES INCREASING...SO DOES THE DEWPOINT TO
ABOVE FREEZING. AS THIS WARMER AND MORE MOIST AIR ADVECTS OVER A
SNOW COVERED GROUND WOULD RESULT IN FOG AS WE WILL PLACE THIS IN THE
GRIDS. STRONG COLD FRONT WITH A FAIRLY TIGHT THERMAL GRADIENT FROM
+8C AT H850 OVER EASTERN NY TO -6C OVER WESTERN NY WILL QUICKLY MOVE
ACROSS THE REGION BY EARLY AFTERNOON PER THE LATEST NCEP MODEL SUITE
TIMING. AN INTERESTING NOTE HERE IS THE SHOWALTER VALUES FROM LATE
MORNING TO EARLY AFTERNOON DROP TO AROUND 0C WHICH SUGGESTS THE
WINDOW OF OPPORTUNITY FOR THUNDER. HOWEVER...WE WILL HOLD OFF ON
THE MENTION IN THE FORECAST/GRIDS UNTIL UPSTREAM TRENDS CAN BE
BETTER OBTAINED.
OVERALL...TEMPERATURES DURING THIS TIME FRAME WILL BE MAINLY
NON-DIURNAL DUE TO THE WARM ADVECTION THURSDAY NIGHT AND CONTINUING
TO RISE THROUGH FRIDAY.
THE LONG TERM WILL FEATURE A RETURN BACK TO WINTER TEMPERATURES AND
A VERY ACTIVE/FAST CYCLONIC FLOW ACROSS THE NORTHEAST CORRIDOR.
THE STORM THAT DEVELOPS OVER THE GREAT LAKES REGION SLOWLY FILLS AND
TRANSITIONS INTO A HUDSON/JAMES BAY LOW. WE WILL BE ON THE SOUTHERN
PERIPHERY OF THIS LOW WHICH KEEPS US RATHER UNSETTLED AND NEAR TO
BELOW NORMAL TEMPERATURES. THE TIMING OF SHORT WAVES WILL BE A
CHALLENGE IN THESE FAST FLOW REGIMES. PER THE GLOBAL MODELS...THE
FIRST WAVE ARRIVES SATURDAY WITH MAINLY THE EASTERN GREAT LAKES AND
SOME LAKE EFFECT SNOW IMPACTING PORTIONS OF THE ADIRONDACKS. THE
NEXT WAVE ARRIVES SUNDAY WITH A BIT MORE OF A SOUTHERN ROUTE. THIS
WAVE ATTEMPTS TO BE AN OVERACHIEVER PER THE ECMWF WITH THE GFS/GGEM
MUCH FLATTER AND MORE PROGRESSIVE. GIVEN THE RECENT TRACK RECORD OF
THE ECMWF...WE WILL PLACE SLIGHT CHANCE POPS FOR NOW.
LOOKING AHEAD INTO THE NEW WORK WEEK...THE HUDSON/JAMES BAY UPPER
LOW LOSES ITS GRIP AS WE MONITOR A POTENT PIECE OF ENERGY DIVE
SOUTHWARD FROM THE NORTHWEST TERRITORIES INTO THE INTERMOUNTAIN
WEST AND QUICKLY OUT ONTO THE CENTRAL PLAINS AND MID WEST BY
TUESDAY. THIS WILL REINTRODUCE THE CHANCE FOR ADDITIONAL WINTRY
PRECIPITATION LATE MONDAY INTO TUESDAY FOR THE ENTIRE CWFA.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
RATHER CHALLENGING IN THE NEAR TERM AS CLEAR SKIES WITH LIGHT WINDS
AND SNOW FROM EARLIER HAS RESULTED IN MVFR/IFR CONDITIONS AT KGFL
WITH OTHER TAF SITES HINTING AT THE POSSIBILITY. WE WILL PLACE A
TEMPO GROUP AT THIS TIME...AS WE MONITOR TRENDS AND UPSTREAM HIGH
AND MID LEVEL CLOUD COVER ADVECTING INTO THE REGION. THIS SHOULD
MINIMIZE THE FOG FROM SPREADING BUT IT WILL BE CLOSE.
AFTER SUNRISE...VISIBILITIES SHOULD IMPROVE AS WE WATCH THE NEXT
CLIPPER SYSTEM APPROACHING. THIS IS EXPECTED TO BRING ANOTHER
CHANCE FOR PRECIPITATION LATE THIS MORNING INTO THE AFTERNOON
HOURS. BOUNDARY LAYER TEMPERATURES WILL BE CLOSE TO RESULT IN
EITHER SN/RASN/RA. FOR NOW...WE FEEL KGFL WILL BE MAINLY SNOW WITH
A MIXTURE FURTHER SOUTH INTO KALB-KPSF AND TRANSITIONING TO ALL RAIN
KPOU. PRECIP SHOULD END THIS EVENING FROM WEST TO EAST RATHER
QUICKLY.
VARIABLE WINDS AT LESS THAN 6 KT WILL SWITCH TO A W-NW DIRECTION
BUT SWITCH TO A SOUTHERLY DIRECTION AND INCREASE TO AROUND 10 KTS
FOR WEDNESDAY MORNING...AND CONTINUE INTO THE AFTERNOON.
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.
&&
.HYDROLOGY...
SNOW DEPTHS ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN NEW
ENGLAND ARE GENERALLY FROM A FOOT TO THREE FEET. ALTHOUGH WE HAVE
WARMER TEMPERATURES IN THE FORECAST FOR THE LATTER PART OF THE
WEEK...EXCEPT FOR THURSDAY NIGHT...OVERNIGHT LOWS WILL BE AROUND OR
SLIGHTLY BELOW FREEZING WHICH SHOULD RESULT IN A SLOW MELT AND
HOPEFULLY MINIMIZE ANY FLOOD THREAT. RAINFALL TOTALS THURSDAY NIGHT
INTO FRIDAY MORNING ARE FORECAST TO GENERALLY BE IN THE QUARTER TO
HALF INCH RANGE...SO MUCH OF THIS RAINFALL SHOULD BE ABSORBED BY THE
CURRENT SNOWPACK.
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 25.7 INCHES THROUGH THE 16TH. THIS AMOUNT IS ONLY 0.3
INCHES FROM REACHING INTO THE TOP 10 FOR SNOWIEST FEBRUARYS SINCE
1885.
A LIGHT TO MODERATE SNOWFALL IS EXPECTED TUESDAY.
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. 27.5 INCHES 1899
8. 26.1 INCHES 1914
9. 26.0 INCHES 1958
10. 26.0 INCHES 1988
LOOKING AT THE SEASONAL SNOWFALL IT STANDS AT 62.8 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...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...KL/GJM
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...BGM
AVIATION...BGM/NAS
HYDROLOGY...KL/GJM
CLIMATE...
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1032 AM EST WED FEB 19 2014
.SYNOPSIS...
A COLD FRONT SAGGING ACROSS THE EASTERN OHIO VALLEY WILL CROSS
THE AREA THIS AFTERNOON. HIGH PRESSURE WILL RETURN TONIGHT AND
THEN DRIFT OFFSHORE THURSDAY. A STRONGER COLD FRONT MOVES THROUGH
FRIDAY. HIGH PRESSURE WILL THEN RETURN OVER THE WEEKEND. LOW
PRESSURE APPROACHES THE REGION TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 10AM...A BAND OF RAIN IS MOVING EAST ACROSS THE I-95
CORRIDOR TOWARD THE CHESAPEAKE BAY. IN PLACES WHERE TEMPERATURES
ARE AT OR JUST BELOW FREEZING...WE HAVE EXTENDED OUR FREEZING RAIN
ADVISORY FOR FREDERICK...CARROLL AND NORTHERN BALTIMORE COUNTIES
THROUGH NOON.
THERE HAVE ALSO BEEN REPORTS OF LIGHTNING AND THUNDER...EITHER BY
STORM SPOTTERS OR BY LIGHTNING DETECTION. MUCH...IF NOT ALL...OF
THE LIGHTNING IS ELEVATED-BASED SINCE WE HAD A MODERATE TO STRONG
INVERSION IN THE BOUNDARY LAYER BUT STEEP LAPSE RATES BETWEEN
850MB AND 700MB. ALSO CONTRIBUTING TO THE ELEVATED CONVECTION IS
A 45 KNOT LOW LEVEL JET AROUND 2000 FEET...A JET STREAK POKING
INTO THE WESTERN PORTION OF OUR REGION FROM THE EASTERN OHIO
VALLEY...AND SOME GOOD PVA WITH A 500 MB SHORTWAVE SLIDING ACROSS
SOUTHERN PENNSYLVANIA.
CONDITIONS WILL IMPROVE FROM WEST TO EAST LATER THIS MORNING AND
AFTERNOON AS A RIDGE OF HIGH PRESSURE BUILDS INTO THE REGION.
PREVIOUS DISCO...
SFC ANALY ALSO SUGGESTING THERE MAY BE A HINT OF A WMFNT
ACRS CWFA...ROUGHLY DOWN THE PTMC. THE CORE OF THE COLD AIR /TEMPS
IN THE TEENS/ IS OVER NEW ENGLAND...BUT SUBFRZG AIR CAN BE FOUND
IN THE PTMC HIGHLANDS AND ACRS NRN MD. MEANWHILE... STRONG ISENT
LIFT IS PRODUCING AN AREA OF PCPN IN THE OH/TN VLYS AND ACRS THE
MTNS OF NC. THAT LIFT...AND THE ASSOC PCPN /WHICH IS ALL
RA/...PROGGED TO ARRIVE IN THE CWFA BTWN 12-14 UTC. HV INCRSD POPS
AND DELAYED TIMING BASED ON LTST GDNC. QSTN REMAINS WHAT WL THE
SFC TEMPS BE WHEN RAIN ARRIVES.
MDL SNDGS...SPCLY FM THE NAM...SUGGEST THAT A STRONG WARM NOSE WL
RESIDE ARND H9 BUT SFC TEMPS WL STILL BE BLO FRZG. GFS IS WARMER AT
THE SFC AND HAS A LESS PRONOUNCED WARM AIR INTRUSION. RAP BTWN THE
TWO THERMALLY...BUT HAS A LATE PCPN ONSET. SINCE NRN MD HAS A SOLID
SNOWPACK...THINK THE NAM IS ONTO SOMETHING...AND PREFER ITS SOLN FOR
THE MRNG. WE HV A FZRA ADVY IN PLACE FOR NRN MD...AND WL BE KEEPING
THAT GOING. ONLY CONCERN IS WHETHER THE NRN PORTION OF THE ERN WVA
PANHNDL /MINERAL TO JEFFERSON CNTYS/ SHUD BE INCLUDED. GRIDS FM 00Z
NAM/GMOS BLENDED IN FCST DATABASE. MUST ADMIT ITS A CLOSE CALL...
BUT SIGNS POINT TO JUST SQUEAKING IT OUT. WL MONITOR CLOSELY...BUT
HV OPTED TO NOT EXPAND CVRG ATTM.
CDFNT CROSSES CWFA DURING THE AFTN HRS...W/ STRONG CAA /AND DP
MIXING/ IN ITS WAKE. AM XPCTG A BRZY AFTN CONSIDERING WNDS AVBL BTWN
H8 AND SFC. WENT ON THE RESERVED SIDE IN DATABASE...KEEPING GUSTS
20-30 MPH. IF FULL MIXING TRANSPIRES...IT MAY BE MORE THAN THAT.
PAST FEW DAYS...TEMPS HV BEEN WARMER THAN PROGGED. SINCE CAA WL BE
ARRIVING LT IN THE DAY...AND WL BE ACCMPNYD BY COMPRESSIONAL
WARMING...WENT ON THE WARM SIDE OF GDNC FOR MAXT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
RDGG /SFC-H7/ WL BUILD ATOP CWFA TNGT...AND PROGRESS TO THE DELMARVA
THU MRNG. AM XPCTG MOCLR SKIES/DIMINISHING WNDS TNGT...AND MIN-T
FLLW SUIT.
BY THU...WL BE BACK IN RTN FLOW...AND SHUD HV A MID DECK CLDS
OVERSPREADING AREA ONCE AGN. THESE CLDS WL THICKEN THRUT THE DAY AS
ISENT LIFT STRENGTHENS. WHILE SOME MDL FIELDS SUGGEST THERE MAY BE A
LTL PCPN BY THE END OF THE DAY...POPS REMAIN VERY LOW. HV
ENTERTAINED A SCHC IN THE NWRN CORNER OF CWFA ONLY...WHICH WUD BE
NEARER A DVLPG WMFNT.
A LTL VARIANCE NOTED IN THU MAXT...BUT ALL GDNC WARMER THAN PRVS
FCST. HV RAISED TEMPS ACCRDGLY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THURSDAY EVENING BEGINS WITH A WARM FRONT LOCATED TO THE SOUTH OF
THE AREA...BUT MODELS SHOW A STRENGTHENING LOW LEVEL JET AND
SOUTHERLY BOUNDARY LAYER WINDS LOOK STRONG ENOUGH TO SEND THIS WARM
FRONT NORTHWARD DURING THE NIGHT THURSDAY. SOME RAIN AND FOG ARE
POSSIBLE THURSDAY NIGHT...BUT AS QUICKLY AS THE WARM FRONT LIFTS
TO THE NORTH A COLD FRONT WILL BE APPROACHING FROM THE WEST.
MODELS/ENSEMBLES HAVE TRENDED FASTER...WITH SHOWERS MOVING INTO THE
POTOMAC HIGHLANDS LATE THURSDAY NIGHT AND THEN AFFECTING THE CWA
PRIMARILY FRIDAY MORNING AND EXITING DURING THE AFTERNOON. A FASTER
PASSAGE MAY HELP LIMIT INSTABILITY AND WIDESPREAD SEVERE...HOWEVER
STRONG WINDS IN THE LOW LEVELS MAY BE TRANSPORTED DOWN TO THE
SURFACE EVEN IN ABSENCE OF THUNDERSTORMS /I.E. WITH ONLY SHOWERS/
AND THUS LOCALLY DAMAGING WINDS WILL BE POSSIBLE IN A HIGH SHEAR
BUT LOW/LITTLE CAPE ENVIRONMENT.
MAXIMA MAY WIND UP OCCURRING DURING FRIDAY MORNING...WITH
TEMPERATURES DROPPING BEHIND THE FRONT LATER FRIDAY. ATTEMPTED TO
REFLECT SOME TIMING DETAILS IN THE GRIDS...INCLUDING FOR
MINIMA/MAXIMA THURSDAY NIGHT/FRIDAY.
DRIER AIR MOVES IN FOR FRIDAY NIGHT AND SATURDAY AND THUS THE RETURN
OF SUNSHINE IS EXPECTED FOR SATURDAY. WITH GOOD INSOLATION AND A
SOUTHWEST FLOW...SATURDAY LOOKS LIKE A MILD DAY WITH MAXIMA 10 PLUS
DEGREES ABOVE AVERAGE.
A REINFORCING COLD FRONT IS EXPECTED ON SUNDAY. ASIDE FROM SOME
CLOUDS AND SILENT POPS OVER THE HIGHLANDS...FRONT LIKELY PASSES
THROUGH RATHER QUIETLY. HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL HOWEVER HAVE SOME COOLER AIR WITH IT /NEAR AVERAGE FOR THIS
TIME OF THE YEAR/ WHICH WILL TAKE HOLD OF THE MID-ATLANTIC EARLY
NEXT WEEK.
NEXT STORM SYSTEM APPROACHES ON TUESDAY...AND HAVE BUMPED POPS UP TO
CHANCE. UNCERTAINTY IN P-TYPE EXISTS AND HAVE GENERIC RAIN OR SNOW
WORDING.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
SOME MVFR CONDITIONS FOR ANOTHER HOUR OR TWO NEAR DCA...BWI...AND
MTN WITH RAIN MOVING EAST. VFR CONDITIONS AFTERWARDS. THERE IS A
THREAT FOR SOME LOW LEVEL WIND SHEAR THROUGH MIDDAY WITH AN
APPROACHING FRONT.
PCPN SHUD BE GONE BY MIDDAY...AND A WSHFT DURING THE AFTN WL
ACCOMPANY A CDFNT. WLY WNDS G25KT LKLY POST FROPA...BUT GRADIENT
/AND WNDS/ WL RELAX AFDK.
HIPRES OVNGT WL NO CIGS AND LTL WND. SLY FLOW WL RESUME THU MRNG...
INCRSG AGN DURING THE AFTN. CIGS WL DVLP AND LWR...BUT SHUD REMAIN
DRY THRU THE DAY W/ VFR CONDS PREVAILING.
THURSDAY NIGHT...FLIGHT RESTRICTIONS MAY DEVELOP IN SOME RAIN/FOG.
SREFS SUGGESTS AT LEAST IFR...WITH SUPPORT FROM MAV/MET. STRONG LLJ
WILL ALSO BRING THE LIKELIHOOD OF LOW LEVEL WIND SHEAR.
FRIDAY...COLD FRONT MOVES ACROSS THE AREA WITH SHOWERS. SHOWERS
COULD TRANSPORT STRONG GUSTY WINDS TO THE SURFACE. FROPA MAY WIND UP
BEING IN THE MORNING...ALTHOUGH EXACT TIMING IS STILL SOMEWHAT
UNCERTAIN.
SATURDAY INTO EARLY NEXT WEEK...HIGH PRESSURE BUILDS IN FOR NO
SIGNIFICANT WEATHER THROUGH MONDAY. NEXT STORM APPROACHES WITH A
CHANCE OF RAIN OR SNOW TUESDAY.
&&
.MARINE...
WNDS WL INCRS TDA AHD OF CDFNT. A STRONG SLY LLJ WL DVLP THIS
MRNG. WHILE THERE WL BE A STRONG INVSN WHICH WL TRAP MOST OF THE
WNDS OFF THE WATERS SFC...THE MAGNITUDE OF WND AND PRESENCE OF RA
MAY MIX A LTL DOWN. HV OPTED TO KEEP SCA GOING FOR MID BAY AND LWR
PTMC... ALTHO ITS NOT OF THE HIEST CONFIDENCE.
POST FROPA THERE IS A GOOD MIXED PROFILE FOR A FEW HRS. SCA IN
EFFECT FOR ALL WATERS TAFTN. THE CFP MAY BE A LTL LATER THAN PRVSLY
PROGGED...AND HV XTNDD SCA FOR THE WATERS INTO ELY EVNG PTMC AND MID
EVNG LWR PTMC/BAY.
GRADIENT WL RELAX OVNGT UNDER HIPRES. SLY FLOW WL RESUME THU. WHILE
GRADIENT INCREASES ONCE AGN...THINK THAT MIXING WL HOLD OFF...AND HV
KEPT WNDS UNDER SCA THRESHOLDS.
STRONG SOUTHERLY JET WILL BE IN PLACE THURSDAY NIGHT. A FRACTION OF
WIND ALOFT WILL LIKELY BE ABLE TO MIX DOWN OVERNIGHT FOR SCA
CONDITIONS. WINDS INCREASE FURTHER FRIDAY MORNING AHEAD OF A COLD
FRONT...POSSIBLY NEAR GALES. SHOWERS ASSOCIATED WITH THE FRONT MAY
ALSO BRING DOWN STRONG GUSTY WINDS. FRONT SHOULD MOVE EAST OF THE
WATERS FRIDAY AFTERNOON. HIGH PRESSURE BUILDS IN OVER THE WEEKEND.
&&
.HYDROLOGY...
WILL BE WATCHING SNOWMELT THIS WEEK AS THE WARMUP ENSUES. SNOW WATER
EQUIVALENT VALUES RANGE FROM LESS THAN AN INCH ALONG AND EAST OF
INTERSTATE 95 TO MORE THAN TWO INCHES WEST OF THE BLUE RIDGE AND
ALONG THE MASON DIXON LINE. OBSERVED SNOW WATER EQUIVALENT IS AROUND
4 INCHES IN THE POTOMAC HIGHLANDS /BUT THE HIGHEST VALUES ARE MAINLY
UPSTREAM OF JENNINGS RANDOLPH AND SAVAGE RIVER LAKES/.
A GRADUAL MELT IS EXPECTED IN THE COMING DAYS...SLIGHTLY MORE
PRONOUNCED THU INTO FRI AS LOWS STAY ABOVE FREEZING THURSDAY NIGHT.
IF MODERATE TO HEAVY PRECIPITATION OCCURRED COINCIDENT WITH THE
MELT...CONCERN WOULD BE HIGH FOR FLOODING. HOWEVER...AT THIS TIME...
RAIN AMOUNTS THROUGH FRIDAY ARE EXPECTED TO BE A HALF INCH OR LESS.
AT THIS TIME THE MOST LIKELY SCENARIO SEEMS TO BE A STEADY
WITHIN-BANK RISE OF STREAMS AND RIVERS LATE THIS WEEK AND INTO THE
WEEKEND. IF RAIN AND/OR SNOWMELT ARE MORE THAN CURRENTLY EXPECTED...
THE FLOOD THREAT WOULD INCREASE ACCORDINGLY FRIDAY AND SATURDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR MDZ004>006.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
ANZ530>534-537>543.
SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR ANZ535-
536.
&&
$$
SYNOPSIS...BPP/KLW
NEAR TERM...HTS/KLW
SHORT TERM...HTS
LONG TERM...BPP
AVIATION...BPP/KLW
MARINE...BPP/HTS
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
655 AM EST WED FEB 19 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY. HIGH PRESSURE WILL RETURN
TONIGHT AND THEN DRIFT OFFSHORE THURSDAY. A STRONGER COLD FRONT
MOVES THROUGH FRIDAY. HIGH PRESSURE WILL THEN RETURN OVER THE
WEEKEND. LOW PRESSURE APPROACHES THE REGION TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDT...
06Z NAM COME IN JUST AS COLD AS THE 00Z RUN. IN ADDITION...REPORTS
FM UPSTREAM SUGGEST ICING OCCURRING EVEN WHERE SFC TEMPS ABV FRZG
DUE TO COLD GRND. LAMP TEMPS HV TRENDED COLDER AS LINE OF PCPN MVS
EWD AND ADDTL PCPN DVLPS E OF MAIN AREA. THAT LEADS TO A GREATER
CONCERN. BASED ON LAMP AND MESO OBS...HV MADE A FAIRLY SIZEABLE
EXPANSION TO FZRA ADVY TO INCL EVERYTHING BTWN APLCNS AND BLURDG
AS WELL AS LOUDOUN- MONTCO- HOWARD AND PRINCE WM CNTYS. FZRA SHUD
BE PATCHY IN LINE W/ SFC TEMPS...BUT ITS PSBL TO GET SOME ICING
EVEN WHERE AIR TEMPS ABV FRZG. HOPEFULLY W/ DAYLIGHT UPON US...
THESE THREATS SHUD BE RATHER SHORT LIVED. KEPT ENDING TIME AT 10AM
FOR ALL CNTYS WHERE ITS VALID.
PRVS DSCN FLLWS...
LOPRES OVER LK SUPERIOR ELY THIS MRNG...W/ AN ATTENDENT CDFNT FM
ORD DOWN THE MID-LWR MS RVR VLY. SFC ANALY ALSO SUGGESTING THERE
MAY BE A HINT OF A WMFNT ACRS CWFA...ROUGHLY DOWN THE PTMC. THE
CORE OF THE COLD AIR /TEMPS IN THE TEENS/ IS OVER NEW
ENGLAND...BUT SUBFRZG AIR CAN BE FOUND IN THE PTMC HIGHLANDS AND
ACRS NRN MD. MEANWHILE... STRONG ISENT LIFT IS PRODUCING AN AREA
OF PCPN IN THE OH/TN VLYS AND ACRS THE MTNS OF NC. THAT LIFT...AND
THE ASSOC PCPN /WHICH IS ALL RA/...PROGGED TO ARRIVE IN THE CWFA
BTWN 12-14 UTC. HV INCRSD POPS AND DELAYED TIMING BASED ON LTST
GDNC. QSTN REMAINS WHAT WL THE SFC TEMPS BE WHEN RAIN ARRIVES.
MDL SNDGS...SPCLY FM THE NAM...SUGGEST THAT A STRONG WARM NOSE WL
RESIDE ARND H9 BUT SFC TEMPS WL STILL BE BLO FRZG. GFS IS WARMER AT
THE SFC AND HAS A LESS PRONOUNCED WARM AIR INTRUSION. RAP BTWN THE
TWO THERMALLY...BUT HAS A LATE PCPN ONSET. SINCE NRN MD HAS A SOLID
SNOWPACK...THINK THE NAM IS ONTO SOMETHING...AND PREFER ITS SOLN FOR
THE MRNG. WE HV A FZRA ADVY IN PLACE FOR NRN MD...AND WL BE KEEPING
THAT GOING. ONLY CONCERN IS WHETHER THE NRN PORTION OF THE ERN WVA
PANHNDL /MINERAL TO JEFFERSON CNTYS/ SHUD BE INCLUDED. GRIDS FM 00Z
NAM/GMOS BLENDED IN FCST DATABASE. MUST ADMIT ITS A CLOSE CALL...
BUT SIGNS POINT TO JUST SQUEAKING IT OUT. WL MONITOR CLOSELY...BUT
HV OPTED TO NOT EXPAND CVRG ATTM.
CDFNT CROSSES CWFA DURING THE AFTN HRS...W/ STRONG CAA /AND DP
MIXING/ IN ITS WAKE. AM XPCTG A BRZY AFTN CONSIDERING WNDS AVBL BTWN
H8 AND SFC. WENT ON THE RESERVED SIDE IN DATABASE...KEEPING GUSTS
20-30 MPH. IF FULL MIXING TRANSPIRES...IT MAY BE MORE THAN THAT.
PAST FEW DAYS...TEMPS HV BEEN WARMER THAN PROGGED. SINCE CAA WL BE
ARRIVING LT IN THE DAY...AND WL BE ACCMPNYD BY COMPRESSIONAL
WARMING...WENT ON THE WARM SIDE OF GDNC FOR MAXT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
RDGG /SFC-H7/ WL BUILD ATOP CWFA TNGT...AND PROGRESS TO THE DELMARVA
THU MRNG. AM XPCTG MOCLR SKIES/DIMINISHING WNDS TNGT...AND MIN-T
FLLW SUIT.
BY THU...WL BE BACK IN RTN FLOW...AND SHUD HV A MID DECK CLDS
OVERSPREADING AREA ONCE AGN. THESE CLDS WL THICKEN THRUT THE DAY AS
ISENT LIFT STRENGTHENS. WHILE SOME MDL FIELDS SUGGEST THERE MAY BE A
LTL PCPN BY THE END OF THE DAY...POPS REMAIN VERY LOW. HV
ENTERTAINED A SCHC IN THE NWRN CORNER OF CWFA ONLY...WHICH WUD BE
NEARER A DVLPG WMFNT.
A LTL VARIANCE NOTED IN THU MAXT...BUT ALL GDNC WARMER THAN PRVS
FCST. HV RAISED TEMPS ACCRDGLY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THURSDAY EVENING BEGINS WITH A WARM FRONT LOCATED TO THE SOUTH OF
THE AREA...BUT MODELS SHOW A STRENGTHENING LOW LEVEL JET AND
SOUTHERLY BOUNDARY LAYER WINDS LOOK STRONG ENOUGH TO SEND THIS WARM
FRONT NORTHWARD DURING THE NIGHT THURSDAY. SOME RAIN AND FOG ARE
POSSIBLE THURSDAY NIGHT...BUT AS QUICKLY AS THE WARM FRONT LIFTS
TO THE NORTH A COLD FRONT WILL BE APPROACHING FROM THE WEST.
MODELS/ENSEMBLES HAVE TRENDED FASTER...WITH SHOWERS MOVING INTO THE
POTOMAC HIGHLANDS LATE THURSDAY NIGHT AND THEN AFFECTING THE CWA
PRIMARILY FRIDAY MORNING AND EXITING DURING THE AFTERNOON. A FASTER
PASSAGE MAY HELP LIMIT INSTABILITY AND WIDESPREAD SEVERE...HOWEVER
STRONG WINDS IN THE LOW LEVELS MAY BE TRANSPORTED DOWN TO THE
SURFACE EVEN IN ABSENCE OF THUNDERSTORMS /I.E. WITH ONLY SHOWERS/
AND THUS LOCALLY DAMAGING WINDS WILL BE POSSIBLE IN A HIGH SHEAR
BUT LOW/LITTLE CAPE ENVIRONMENT.
MAXIMA MAY WIND UP OCCURRING DURING FRIDAY MORNING...WITH
TEMPERATURES DROPPING BEHIND THE FRONT LATER FRIDAY. ATTEMPTED TO
REFLECT SOME TIMING DETAILS IN THE GRIDS...INCLUDING FOR
MINIMA/MAXIMA THURSDAY NIGHT/FRIDAY.
DRIER AIR MOVES IN FOR FRIDAY NIGHT AND SATURDAY AND THUS THE RETURN
OF SUNSHINE IS EXPECTED FOR SATURDAY. WITH GOOD INSOLATION AND A
SOUTHWEST FLOW...SATURDAY LOOKS LIKE A MILD DAY WITH MAXIMA 10 PLUS
DEGREES ABOVE AVERAGE.
A REINFORCING COLD FRONT IS EXPECTED ON SUNDAY. ASIDE FROM SOME
CLOUDS AND SILENT POPS OVER THE HIGHLANDS...FRONT LIKELY PASSES
THROUGH RATHER QUIETLY. HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL HOWEVER HAVE SOME COOLER AIR WITH IT /NEAR AVERAGE FOR THIS
TIME OF THE YEAR/ WHICH WILL TAKE HOLD OF THE MID-ATLANTIC EARLY
NEXT WEEK.
NEXT STORM SYSTEM APPROACHES ON TUESDAY...AND HAVE BUMPED POPS UP TO
CHANCE. UNCERTAINTY IN P-TYPE EXISTS AND HAVE GENERIC RAIN OR SNOW
WORDING.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS ATTM..BUT XPCT PCPN TO OVERSPREAD TERMINALS DURING THE
MRNG PUSH. FLGT RESTRICTIONS MAY DVLP...BUT DO NOT XPCT MUCH WORSE
THAN MVFR. TEMPS SHUD BE WARM ENUF BY THE TIME PCPN ARRIVES /11-13
UTC/ FOR NO PTYPE CONCERNS--XPCT JUST RAIN. THE CLOSEST CALL WL BE
AT MRB AND MTN...WHERE THERE IS A CHC AT BRIEF FZRA AT ONSET. PCPN
DRIVEN BY A STRONG LLJ...AND HV LLWS CONDS IN TAFS THRU THE MRNG /UP
TO 45 KT/.
PCPN SHUD BE GONE BY MIDDAY...AND A WSHFT DURING THE AFTN WL
ACCOMPANY A CDFNT. WLY WNDS G25KT LKLY POST FROPA...BUT GRADIENT
/AND WNDS/ WL RELAX AFDK.
HIPRES OVNGT WL NO CIGS AND LTL WND. SLY FLOW WL RESUME THU MRNG...
INCRSG AGN DURING THE AFTN. CIGS WL DVLP AND LWR...BUT SHUD REMAIN
DRY THRU THE DAY W/ VFR CONDS PREVAILING.
THURSDAY NIGHT...FLIGHT RESTRICTIONS MAY DEVELOP IN SOME RAIN/FOG.
SREFS SUGGESTS AT LEAST IFR...WITH SUPPORT FROM MAV/MET. STRONG LLJ
WILL ALSO BRING THE LIKELIHOOD OF LOW LEVEL WIND SHEAR.
FRIDAY...COLD FRONT MOVES ACROSS THE AREA WITH SHOWERS. SHOWERS
COULD TRANSPORT STRONG GUSTY WINDS TO THE SURFACE. FROPA MAY WIND UP
BEING IN THE MORNING...ALTHOUGH EXACT TIMING IS STILL SOMEWHAT
UNCERTAIN.
SATURDAY INTO EARLY NEXT WEEK...HIGH PRESSURE BUILDS IN FOR NO
SIGNIFICANT WEATHER THROUGH MONDAY. NEXT STORM APPROACHES WITH A
CHANCE OF RAIN OR SNOW TUESDAY.
&&
.MARINE...
WHILE QUIET CONDS PREVAIL ON THE WATERS ATTM SLY WNDS AOB 10 KT/...
WNDS WL INCRS TDA AHD OF CDFNT. A STRONG SLY LLJ WL DVLP THIS MRNG.
WHILE THERE WL BE A STRONG INVSN WHICH WL TRAP MOST OF THE WNDS OFF
THE WATERS SFC...THE MAGNITUDE OF WND AND PRESENCE OF RA MAY MIX A
LTL DOWN. HV OPTED TO KEEP SCA GOING FOR MID BAY AND LWR PTMC...
ALTHO ITS NOT OF THE HIEST CONFIDENCE.
POST FROPA THERE IS A GOOD MIXED PROFILE FOR A FEW HRS. SCA IN
EFFECT FOR ALL WATERS TAFTN. THE CFP MAY BE A LTL LATER THAN PRVSLY
PROGGED...AND HV XTNDD SCA FOR THE WATERS INTO ELY EVNG PTMC AND MID
EVNG LWR PTMC/BAY.
GRADIENT WL RELAX OVNGT UNDER HIPRES. SLY FLOW WL RESUME THU. WHILE
GRADIENT INCREASES ONCE AGN...THINK THAT MIXING WL HOLD OFF...AND HV
KEPT WNDS UNDER SCA THRESHOLDS.
STRONG SOUTHERLY JET WILL BE IN PLACE THURSDAY NIGHT. A FRACTION OF
WIND ALOFT WILL LIKELY BE ABLE TO MIX DOWN OVERNIGHT FOR SCA
CONDITIONS. WINDS INCREASE FURTHER FRIDAY MORNING AHEAD OF A COLD
FRONT...POSSIBLY NEAR GALES. SHOWERS ASSOCIATED WITH THE FRONT MAY
ALSO BRING DOWN STRONG GUSTY WINDS. FRONT SHOULD MOVE EAST OF THE
WATERS FRIDAY AFTERNOON. HIGH PRESSURE BUILDS IN OVER THE WEEKEND.
&&
.HYDROLOGY...
WILL BE WATCHING SNOWMELT THIS WEEK AS THE WARMUP ENSUES. SNOW WATER
EQUIVALENT VALUES RANGE FROM LESS THAN AN INCH ALONG AND EAST OF
INTERSTATE 95 TO MORE THAN TWO INCHES WEST OF THE BLUE RIDGE AND
ALONG THE MASON DIXON LINE. OBSERVED SNOW WATER EQUIVALENT IS AROUND
4 INCHES IN THE POTOMAC HIGHLANDS /BUT THE HIGHEST VALUES ARE MAINLY
UPSTREAM OF JENNINGS RANDOLPH AND SAVAGE RIVER LAKES/.
A GRADUAL MELT IS EXPECTED IN THE COMING DAYS...SLIGHTLY MORE
PRONOUNCED THU INTO FRI AS LOWS STAY ABOVE FREEZING THURSDAY NIGHT.
IF MODERATE TO HEAVY PRECIPITATION OCCURRED COINCIDENT WITH THE
MELT...CONCERN WOULD BE HIGH FOR FLOODING. HOWEVER...AT THIS TIME...
RAIN AMOUNTS THROUGH FRIDAY ARE EXPECTED TO BE A HALF INCH OR LESS.
AT THIS TIME THE MOST LIKELY SCENARIO SEEMS TO BE A STEADY
WITHIN-BANK RISE OF STREAMS AND RIVERS LATE THIS WEEK AND INTO THE
WEEKEND. IF RAIN AND/OR SNOWMELT ARE MORE THAN CURRENTLY EXPECTED...
THE FLOOD THREAT WOULD INCREASE ACCORDINGLY FRIDAY AND SATURDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MDZ003>007-009-010-501-502.
VA...FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
VAZ025>031-040-042-052-501-503-504.
WV...FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
ANZ532>534-537-540>543.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 11 PM EST THIS
EVENING FOR ANZ530-531-538-539.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 8 PM EST THIS
EVENING FOR ANZ535-536.
&&
$$
SYNOPSIS...BPP
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...BPP
AVIATION...HTS/BPP
MARINE...HTS/BPP
HYDROLOGY...JCE
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
510 AM EST WED FEB 19 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY. HIGH PRESSURE WILL RETURN
TONIGHT AND THEN DRIFT OFFSHORE THURSDAY. A STRONGER COLD FRONT
MOVES THROUGH FRIDAY. HIGH PRESSURE WILL THEN RETURN OVER THE
WEEKEND. LOW PRESSURE APPROACHES THE REGION TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDT...
06Z NAM COME IN JUST AS COLD AS THE 00Z RUN. IN ADDITION...REPORTS
FM UPSTREAM SUGGEST ICING OCCURRING EVEN WHERE SFC TEMPS ABV FRZG
DUE TO COLD GRND. THEREFORE...HV ADDED ENTIRE ERN WV PNHNDL TO
FZRA ADVY. LEFT HIGHLAND CO VA OUT DUE TO SFC TEMP AT HSP IN THE
40S. IN ADDITION...LEFT CENTRAL SHEN VLY OUT IN SPITE OF COLD
TEMPS AS PRECIP THERE NOT IMMINENT...AND NO HIER THAN CHC. LOOKING
AT RDR LOOP THAT MAKES SENSE...SINCE THERE/S A GAP BTWN THE
PREFRNTL RAIN TO THE W AND THE LEADING EDGE OF THE LLJ TO THE S.
FINALLY... HV RESTRUCTURED END TIME TO FIT EVOLUTION. WARMTH FM
ALOFT SHUD ENCOMPASS RDGS OF THE PTMC HIGHLANDS...AND HV ENDING
TIME THERE A CPL HRS ERLR THAN CENTRAL-NERN MD.
WL STILL NEED TO MONITOR EDGE OF LOUDOUN-MONTCO-HOWARD CNTYS.
JYO/GAI BOTH ABV FRZG. THINK PCPN WL MAKE IT INTO BURBS BY 12-13
UTC. AM HOPING THAT GRND CAN WARM A PINCH AFTER DAYLIGHT. SFC
TEMPS ALREADY ABV FRZG.
OTRW...THOUGHT PROCESS SAME AS BEFORE...AS DETAILED IN THE PREV
DSCN...WHICH FLLWS...
LOPRES OVER LK SUPERIOR ELY THIS MRNG...W/ AN ATTENDENT CDFNT FM
ORD DOWN THE MID-LWR MS RVR VLY. SFC ANALY ALSO SUGGESTING THERE
MAY BE A HINT OF A WMFNT ACRS CWFA...ROUGHLY DOWN THE PTMC. THE
CORE OF THE COLD AIR /TEMPS IN THE TEENS/ IS OVER NEW
ENGLAND...BUT SUBFRZG AIR CAN BE FOUND IN THE PTMC HIGHLANDS AND
ACRS NRN MD. MEANWHILE... STRONG ISENT LIFT IS PRODUCING AN AREA
OF PCPN IN THE OH/TN VLYS AND ACRS THE MTNS OF NC. THAT LIFT...AND
THE ASSOC PCPN /WHICH IS ALL RA/...PROGGED TO ARRIVE IN THE CWFA
BTWN 12-14 UTC. HV INCRSD POPS AND DELAYED TIMING BASED ON LTST
GDNC. QSTN REMAINS WHAT WL THE SFC TEMPS BE WHEN RAIN ARRIVES.
MDL SNDGS...SPCLY FM THE NAM...SUGGEST THAT A STRONG WARM NOSE WL
RESIDE ARND H9 BUT SFC TEMPS WL STILL BE BLO FRZG. GFS IS WARMER AT
THE SFC AND HAS A LESS PRONOUNCED WARM AIR INTRUSION. RAP BTWN THE
TWO THERMALLY...BUT HAS A LATE PCPN ONSET. SINCE NRN MD HAS A SOLID
SNOWPACK...THINK THE NAM IS ONTO SOMETHING...AND PREFER ITS SOLN FOR
THE MRNG. WE HV A FZRA ADVY IN PLACE FOR NRN MD...AND WL BE KEEPING
THAT GOING. ONLY CONCERN IS WHETHER THE NRN PORTION OF THE ERN WVA
PANHNDL /MINERAL TO JEFFERSON CNTYS/ SHUD BE INCLUDED. GRIDS FM 00Z
NAM/GMOS BLENDED IN FCST DATABASE. MUST ADMIT ITS A CLOSE CALL...
BUT SIGNS POINT TO JUST SQUEAKING IT OUT. WL MONITOR CLOSELY...BUT
HV OPTED TO NOT EXPAND CVRG ATTM.
CDFNT CROSSES CWFA DURING THE AFTN HRS...W/ STRONG CAA /AND DP
MIXING/ IN ITS WAKE. AM XPCTG A BRZY AFTN CONSIDERING WNDS AVBL BTWN
H8 AND SFC. WENT ON THE RESERVED SIDE IN DATABASE...KEEPING GUSTS
20-30 MPH. IF FULL MIXING TRANSPIRES...IT MAY BE MORE THAN THAT.
PAST FEW DAYS...TEMPS HV BEEN WARMER THAN PROGGED. SINCE CAA WL BE
ARRIVING LT IN THE DAY...AND WL BE ACCMPNYD BY COMPRESSIONAL
WARMING...WENT ON THE WARM SIDE OF GDNC FOR MAXT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
RDGG /SFC-H7/ WL BUILD ATOP CWFA TNGT...AND PROGRESS TO THE DELMARVA
THU MRNG. AM XPCTG MOCLR SKIES/DIMINISHING WNDS TNGT...AND MIN-T
FLLW SUIT.
BY THU...WL BE BACK IN RTN FLOW...AND SHUD HV A MID DECK CLDS
OVERSPREADING AREA ONCE AGN. THESE CLDS WL THICKEN THRUT THE DAY AS
ISENT LIFT STRENGTHENS. WHILE SOME MDL FIELDS SUGGEST THERE MAY BE A
LTL PCPN BY THE END OF THE DAY...POPS REMAIN VERY LOW. HV
ENTERTAINED A SCHC IN THE NWRN CORNER OF CWFA ONLY...WHICH WUD BE
NEARER A DVLPG WMFNT.
A LTL VARIANCE NOTED IN THU MAXT...BUT ALL GDNC WARMER THAN PRVS
FCST. HV RAISED TEMPS ACCRDGLY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THURSDAY EVENING BEGINS WITH A WARM FRONT LOCATED TO THE SOUTH OF
THE AREA...BUT MODELS SHOW A STRENGTHENING LOW LEVEL JET AND
SOUTHERLY BOUNDARY LAYER WINDS LOOK STRONG ENOUGH TO SEND THIS WARM
FRONT NORTHWARD DURING THE NIGHT THURSDAY. SOME RAIN AND FOG ARE
POSSIBLE THURSDAY NIGHT...BUT AS QUICKLY AS THE WARM FRONT LIFTS
TO THE NORTH A COLD FRONT WILL BE APPROACHING FROM THE WEST.
MODELS/ENSEMBLES HAVE TRENDED FASTER...WITH SHOWERS MOVING INTO THE
POTOMAC HIGHLANDS LATE THURSDAY NIGHT AND THEN AFFECTING THE CWA
PRIMARILY FRIDAY MORNING AND EXITING DURING THE AFTERNOON. A FASTER
PASSAGE MAY HELP LIMIT INSTABILITY AND WIDESPREAD SEVERE...HOWEVER
STRONG WINDS IN THE LOW LEVELS MAY BE TRANSPORTED DOWN TO THE
SURFACE EVEN IN ABSENCE OF THUNDERSTORMS /I.E. WITH ONLY SHOWERS/
AND THUS LOCALLY DAMAGING WINDS WILL BE POSSIBLE IN A HIGH SHEAR
BUT LOW/LITTLE CAPE ENVIRONMENT.
MAXIMA MAY WIND UP OCCURRING DURING FRIDAY MORNING...WITH
TEMPERATURES DROPPING BEHIND THE FRONT LATER FRIDAY. ATTEMPTED TO
REFLECT SOME TIMING DETAILS IN THE GRIDS...INCLUDING FOR
MINIMA/MAXIMA THURSDAY NIGHT/FRIDAY.
DRIER AIR MOVES IN FOR FRIDAY NIGHT AND SATURDAY AND THUS THE RETURN
OF SUNSHINE IS EXPECTED FOR SATURDAY. WITH GOOD INSOLATION AND A
SOUTHWEST FLOW...SATURDAY LOOKS LIKE A MILD DAY WITH MAXIMA 10 PLUS
DEGREES ABOVE AVERAGE.
A REINFORCING COLD FRONT IS EXPECTED ON SUNDAY. ASIDE FROM SOME
CLOUDS AND SILENT POPS OVER THE HIGHLANDS...FRONT LIKELY PASSES
THROUGH RATHER QUIETLY. HIGH PRESSURE BUILDING IN BEHIND THE FRONT
WILL HOWEVER HAVE SOME COOLER AIR WITH IT /NEAR AVERAGE FOR THIS
TIME OF THE YEAR/ WHICH WILL TAKE HOLD OF THE MID-ATLANTIC EARLY
NEXT WEEK.
NEXT STORM SYSTEM APPROACHES ON TUESDAY...AND HAVE BUMPED POPS UP TO
CHANCE. UNCERTAINTY IN P-TYPE EXISTS AND HAVE GENERIC RAIN OR SNOW
WORDING.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS ATTM..BUT XPCT PCPN TO OVERSPREAD TERMINALS DURING THE
MRNG PUSH. FLGT RESTRICTIONS MAY DVLP...BUT DO NOT XPCT MUCH WORSE
THAN MVFR. TEMPS SHUD BE WARM ENUF BY THE TIME PCPN ARRIVES /11-13
UTC/ FOR NO PTYPE CONCERNS--XPCT JUST RAIN. THE CLOSEST CALL WL BE
AT MRB AND MTN...WHERE THERE IS A CHC AT BRIEF FZRA AT ONSET. PCPN
DRIVEN BY A STRONG LLJ...AND HV LLWS CONDS IN TAFS THRU THE MRNG /UP
TO 45 KT/.
PCPN SHUD BE GONE BY MIDDAY...AND A WSHFT DURING THE AFTN WL
ACCOMPANY A CDFNT. WLY WNDS G25KT LKLY POST FROPA...BUT GRADIENT
/AND WNDS/ WL RELAX AFDK.
HIPRES OVNGT WL NO CIGS AND LTL WND. SLY FLOW WL RESUME THU MRNG...
INCRSG AGN DURING THE AFTN. CIGS WL DVLP AND LWR...BUT SHUD REMAIN
DRY THRU THE DAY W/ VFR CONDS PREVAILING.
THURSDAY NIGHT...FLIGHT RESTRICTIONS MAY DEVELOP IN SOME RAIN/FOG.
SREFS SUGGESTS AT LEAST IFR...WITH SUPPORT FROM MAV/MET. STRONG LLJ
WILL ALSO BRING THE LIKELIHOOD OF LOW LEVEL WIND SHEAR.
FRIDAY...COLD FRONT MOVES ACROSS THE AREA WITH SHOWERS. SHOWERS
COULD TRANSPORT STRONG GUSTY WINDS TO THE SURFACE. FROPA MAY WIND UP
BEING IN THE MORNING...ALTHOUGH EXACT TIMING IS STILL SOMEWHAT
UNCERTAIN.
SATURDAY INTO EARLY NEXT WEEK...HIGH PRESSURE BUILDS IN FOR NO
SIGNIFICANT WEATHER THROUGH MONDAY. NEXT STORM APPROACHES WITH A
CHANCE OF RAIN OR SNOW TUESDAY.
&&
.MARINE...
WHILE QUIET CONDS PREVAIL ON THE WATERS ATTM SLY WNDS AOB 10 KT/...
WNDS WL INCRS TDA AHD OF CDFNT. A STRONG SLY LLJ WL DVLP THIS MRNG.
WHILE THERE WL BE A STRONG INVSN WHICH WL TRAP MOST OF THE WNDS OFF
THE WATERS SFC...THE MAGNITUDE OF WND AND PRESENCE OF RA MAY MIX A
LTL DOWN. HV OPTED TO KEEP SCA GOING FOR MID BAY AND LWR PTMC...
ALTHO ITS NOT OF THE HIEST CONFIDENCE.
POST FROPA THERE IS A GOOD MIXED PROFILE FOR A FEW HRS. SCA IN
EFFECT FOR ALL WATERS TAFTN. THE CFP MAY BE A LTL LATER THAN PRVSLY
PROGGED...AND HV XTNDD SCA FOR THE WATERS INTO ELY EVNG PTMC AND MID
EVNG LWR PTMC/BAY.
GRADIENT WL RELAX OVNGT UNDER HIPRES. SLY FLOW WL RESUME THU. WHILE
GRADIENT INCREASES ONCE AGN...THINK THAT MIXING WL HOLD OFF...AND HV
KEPT WNDS UNDER SCA THRESHOLDS.
STRONG SOUTHERLY JET WILL BE IN PLACE THURSDAY NIGHT. A FRACTION OF
WIND ALOFT WILL LIKELY BE ABLE TO MIX DOWN OVERNIGHT FOR SCA
CONDITIONS. WINDS INCREASE FURTHER FRIDAY MORNING AHEAD OF A COLD
FRONT...POSSIBLY NEAR GALES. SHOWERS ASSOCIATED WITH THE FRONT MAY
ALSO BRING DOWN STRONG GUSTY WINDS. FRONT SHOULD MOVE EAST OF THE
WATERS FRIDAY AFTERNOON. HIGH PRESSURE BUILDS IN OVER THE WEEKEND.
&&
.HYDROLOGY...
WILL BE WATCHING SNOWMELT THIS WEEK AS THE WARMUP ENSUES. SNOW WATER
EQUIVALENT VALUES RANGE FROM LESS THAN AN INCH ALONG AND EAST OF
INTERSTATE 95 TO MORE THAN TWO INCHES WEST OF THE BLUE RIDGE AND
ALONG THE MASON DIXON LINE. OBSERVED SNOW WATER EQUIVALENT IS AROUND
4 INCHES IN THE POTOMAC HIGHLANDS /BUT THE HIGHEST VALUES ARE MAINLY
UPSTREAM OF JENNINGS RANDOLPH AND SAVAGE RIVER LAKES/.
A GRADUAL MELT IS EXPECTED IN THE COMING DAYS...SLIGHTLY MORE
PRONOUNCED THU INTO FRI AS LOWS STAY ABOVE FREEZING THURSDAY NIGHT.
IF MODERATE TO HEAVY PRECIPITATION OCCURRED COINCIDENT WITH THE
MELT...CONCERN WOULD BE HIGH FOR FLOODING. HOWEVER...AT THIS TIME...
RAIN AMOUNTS THROUGH FRIDAY ARE EXPECTED TO BE A HALF INCH OR LESS.
AT THIS TIME THE MOST LIKELY SCENARIO SEEMS TO BE A STEADY
WITHIN-BANK RISE OF STREAMS AND RIVERS LATE THIS WEEK AND INTO THE
WEEKEND. IF RAIN AND/OR SNOWMELT ARE MORE THAN CURRENTLY EXPECTED...
THE FLOOD THREAT WOULD INCREASE ACCORDINGLY FRIDAY AND SATURDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...FREEZING RAIN ADVISORY UNTIL 8 AM EST THIS MORNING FOR MDZ501-
502.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MDZ003>007.
VA...NONE.
WV...FREEZING RAIN ADVISORY UNTIL 8 AM EST THIS MORNING FOR WVZ050-
055-501>506.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR
ANZ532>534-537-540>543.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 11 PM EST THIS
EVENING FOR ANZ530-531-538-539.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 8 PM EST THIS
EVENING FOR ANZ535-536.
&&
$$
SYNOPSIS...BPP
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...BPP
AVIATION...HTS/BPP
MARINE...HTS/BPP
HYDROLOGY...JCE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
649 AM EST WED FEB 19 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 326 AM EST WED FEB 19 2014
WE/LL SEE QUITE A BIT OF SUNSHINE TODAY BUT KEEP AN EYE TO THE
SOUTHWEST AS A STORM DEVELOPS IN THE PLAINS. THAT STORM WILL MOVE
TOWARD THE GREAT LAKES THURSDAY AND STRENGTHEN. INITIALLY...A MIX OF
RAIN, FREEZING RAIN, AND SNOW WILL DEVELOP THURSDAY MORNING BUT
CHANGE TO RAIN FROM SOUTH TO NORTH AS WARMER IS IS DRAWN NORTH.
THUNDERSTORMS ARE POSSIBLE TOO THURSDAY AFTERNOON. STRONG WINDS WILL
DEVELOP THURSDAY NIGHT AND CONTINUE INTO FRIDAY MORNING.
&&
.UPDATE...
ISSUED AT 610 AM EST WED FEB 19 2014
ISSUED A QUICK FORECAST UPDATE TO COVER THE NARROW BAND OF PRECIP
APPROACHING FROM THE WEST. THOUGHT THE DRY AIR WOULD ERODE THIS
PRECIP BEFORE IT GOT HERE BUT A FEW 30 DBZ ECHOES ARE MOVING
ACROSS THE LAKE AND SOME OF IT WILL OBVIOUSLY GET HERE.
PRECIP TYPE IS TRICKY. LATEST RAP FCST SOUNDINGS SUGGEST A MIX OF
LIGHT FREEZING RAIN AND SNOW INITIALLY ALTHOUGH WET BULB EFFECTS
THEN COOL THE SOUNDINGS BELOW FREEZING AS THE COLUMN MOISTENS
SUGGESTING ALL SNOW. THE PRECIP DOES NOT APPEAR HEAVY ENOUGH OR OF
LONG ENOUGH DURATION THAT THE COOLING WOULD BE THAT DRAMATIC SO A
BRIEF LIGHT MIX SEEMS THE MOST LIKELY SCENARIO AS THIS BAND MOVES
THROUGH.
SFC TEMPS SHOULD WARM ABOVE FREEZING AFTER 10 AM SO ANY LINGERING
PRECIP MOVING SOUTH AND EAST OF GRR AT THAT TIME SHOULD BE MIXED
RAIN AND SNOW.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 326 AM EST WED FEB 19 2014
FORECAST CONCERNS DEAL WITH THE APPROACHING STORM THURSDAY.
AFTER A MOSTLY SUNNY DAY SKIES WILL BEGIN TO CLOUD UP TONIGHT. LOW
PRESSURE DEVELOPING OVER THE SOUTHERN PLAINS WILL MOVE NORTHEAST
TUESDAY AND RAPIDLY DEEPEN AS IT MOVES WEST OF THE CWA ACROSS
EASTERN WISCONSIN. PCPN WILL MOVE INTO THE SW CWA AFTER 12Z
THURSDAY. INITIALLY, FORECAST SOUNDINGS SUGGEST THE PCPN WILL BE A
MIX OF RAIN, FREEZING RAIN AND SLEET. NORTH OF I-96, MUCH OF THE
PCPN WILL BE SNOW WITH FREEZING RAIN MIXING IN. I SUSPECT WE`LL NEED
A WINTER WEATHER ADVISORY THURSDAY FOR MUCH OF THE CWA.
H8 WINDS NEAR 70KTS WILL DRAW ABUNDANT WARM AIR NORTHWARD AND THE
PCPN WILL CHANGE TO RAIN FROM SOUTH TO NORTH. QPF IN THE HALF INCH
TO INCH RANGE WILL MOSTLY GET TRAPPED IN THE SNOW PACK AND THAT`S
NOT GOOD NEWS BECAUSE THE ADDED WEIGHT TO THE SNOWPACK WILL LIKELY
RESULT IN MORE ROOF COLLAPSES. PONDING ON ROADS DUE TO CLOGGED STORM
DRAINS WILL ALSO BE AN ISSUES. MODELS SNOW SFC DEWPOINTS RISING
ABOVE FREEZING LATE IN THE DAY AND THAT`S WHEN VISIBILITIES WILL
DECREASE THE MOST.
ALONG WITH THE WARMER AIR WILL COME INCREASED INSTABILITY. ELEVATED
LI`S ARE BELOW 0C AND MUCAPE RISES TO 500 J/KG. GIVEN SHEAR VALUES
OVER 60KTS...WE`LL LIKELY SEE THUNDERSTORMS DEVELOP. THE BEST CHANCE
FOR STRONG TO SEVERE STORMS WILL BE JUST SOUTH OF THE CWA.
AN OCCLUDED FRONT WILL SWEEP IN FROM THE WEST THURSDAY EVENING.
STRONG WEST WINDS WILL DEVELOP AND GUST TO 40-45 MPH AND COLDER AIR
WILL MOVE BACK INTO THE CWA. SNOW SHOWERS AND COLDER TEMPERATURES
ARE EXPECTED FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 AM EST WED FEB 19 2014
THE LONG TERM PERIOD WILL FEATURE GENERALLY QUIET WEATHER WITH BELOW
NORMAL TEMPERATURES AS A BROAD UPPER TROUGH REMAINS FIRMLY ANCHORED
OVER MOST OF CANADA AND THE NORTHERN AND EASTERN UNITED STATES. THE
PERSISTENT COLD CYCLONIC FLOW WILL PROMOTE OCCASIONAL LIGHT LAKE
EFFECT SNOW SHOWER ACTIVITY BUT NO SIGNIFICANT ACCUMULATIONS ARE
EXPECTED. CLIPPER TYPE SHORTWAVES DIVING THROUGH THE NORTHWEST FLOW
ALOFT COULD BRING BRIEF PERIODS SNOW SHOWER ENHANCEMENT BUT AGAIN NO
MAJOR SYSTEMS ARE FORESEEN AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 648 AM EST WED FEB 19 2014
A NARROW BAND OF LIGHT FREEZING RAIN AND LIGHT SNOW WILL IMPACT
THE TERMINALS FOR ABOUT AN HOUR THIS MORNING RESULTING IN A BRIEF
PERIOD OF MVFR CONDITIONS AND PERHAPS SOME LIGHT ICING. OTHERWISE
VFR CONDITIONS WILL PREVAIL BOTH AHEAD AND BEHIND THIS BAND... WITH
SKIES CLEARING 16-18Z BEHIND THE EXITING/DIMINISHING PRECIP.
&&
.HYDROLOGY...
ISSUED AT 141 PM EST TUE FEB 18 2014
RAIN COULD BE HEAVY AT TIMES THURSDAY INTO THURSDAY NIGHT AS
TEMPERATURES WARM UP. UPWARDS OF AN INCH OF RAIN IS FORECASTED. WE
WILL SEE SOME RUNOFF WHICH MAY LEAD TO URBAN AND POOR DRAINAGE
FLOODING. THE WARM TEMPERATURES WILL LAST LESS THAN 24 HRS THEN WE
DROP BACK DOWN BELOW FREEZING. THUS IT APPEARS THAT NOT ENOUGH
RUNOFF WILL OCCUR TO TRIGGER WIDESPREAD FLOODING...INCLUDING ICE
BREAKUP AND JAMS. WILL NEED TO MONITOR THE SITUATION CLOSELY IN
THE COMING DAYS.
ICE JAMS IN RIVERS TEND TO FORM NEAR SHARP BENDS...IN SHALLOW
AREAS...AND NEAR OBSTRUCTIONS...LIKE BRIDGES AND ISLANDS. ICE
BREAKUP ON RIVERS CAN OCCUR WHENEVER THE RIVER STAGE RISES 1.5 TO 3
TIMES THE RIVER ICE THICKNESS. ICE JAMS ON RIVERS CAN RESULT IN
UNPREDICTABLE RAPID RISES ON RIVERS.
UNTIL THEN...LITTLE CHANGE IS EXPECTED ON AREA RIVERS AS ICE REMAINS
LARGELY LOCKED IN PLACE ACROSS MOST RIVERS AND STREAMS AS FLOW IS
NEAR NORMAL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...93
SHORT TERM...93
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...MJS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
610 AM EST WED FEB 19 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 326 AM EST WED FEB 19 2014
WE/LL SEE QUITE A BIT OF SUNSHINE TODAY BUT KEEP AN EYE TO THE
SOUTHWEST AS A STORM DEVELOPS IN THE PLAINS. THAT STORM WILL MOVE
TOWARD THE GREAT LAKES THURSDAY AND STRENGTHEN. INITIALLY...A MIX OF
RAIN, FREEZING RAIN, AND SNOW WILL DEVELOP THURSDAY MORNING BUT
CHANGE TO RAIN FROM SOUTH TO NORTH AS WARMER IS IS DRAWN NORTH.
THUNDERSTORMS ARE POSSIBLE TOO THURSDAY AFTERNOON. STRONG WINDS WILL
DEVELOP THURSDAY NIGHT AND CONTINUE INTO FRIDAY MORNING.
&&
.UPDATE...
ISSUED AT 610 AM EST WED FEB 19 2014
ISSUED A QUICK FORECAST UPDATE TO COVER THE NARROW BAND OF PRECIP
APPROACHING FROM THE WEST. THOUGHT THE DRY AIR WOULD ERODE THIS
PRECIP BEFORE IT GOT HERE BUT A FEW 30 DBZ ECHOES ARE MOVING
ACROSS THE LAKE AND SOME OF IT WILL OBVIOUSLY GET HERE.
PRECIP TYPE IS TRICKY. LATEST RAP FCST SOUNDINGS SUGGEST A MIX OF
LIGHT FREEZING RAIN AND SNOW INITIALLY ALTHOUGH WET BULB EFFECTS
THEN COOL THE SOUNDINGS BELOW FREEZING AS THE COLUMN MOISTENS
SUGGESTING ALL SNOW. THE PRECIP DOES NOT APPEAR HEAVY ENOUGH OR OF
LONG ENOUGH DURATION THAT THE COOLING WOULD BE THAT DRAMATIC SO A
BRIEF LIGHT MIX SEEMS THE MOST LIKELY SCENARIO AS THIS BAND MOVES
THROUGH.
SFC TEMPS SHOULD WARM ABOVE FREEZING AFTER 10 AM SO ANY LINGERING
PRECIP MOVING SOUTH AND EAST OF GRR AT THAT TIME SHOULD BE MIXED
RAIN AND SNOW.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 326 AM EST WED FEB 19 2014
FORECAST CONCERNS DEAL WITH THE APPROACHING STORM THURSDAY.
AFTER A MOSTLY SUNNY DAY SKIES WILL BEGIN TO CLOUD UP TONIGHT. LOW
PRESSURE DEVELOPING OVER THE SOUTHERN PLAINS WILL MOVE NORTHEAST
TUESDAY AND RAPIDLY DEEPEN AS IT MOVES WEST OF THE CWA ACROSS
EASTERN WISCONSIN. PCPN WILL MOVE INTO THE SW CWA AFTER 12Z
THURSDAY. INITIALLY, FORECAST SOUNDINGS SUGGEST THE PCPN WILL BE A
MIX OF RAIN, FREEZING RAIN AND SLEET. NORTH OF I-96, MUCH OF THE
PCPN WILL BE SNOW WITH FREEZING RAIN MIXING IN. I SUSPECT WE`LL NEED
A WINTER WEATHER ADVISORY THURSDAY FOR MUCH OF THE CWA.
H8 WINDS NEAR 70KTS WILL DRAW ABUNDANT WARM AIR NORTHWARD AND THE
PCPN WILL CHANGE TO RAIN FROM SOUTH TO NORTH. QPF IN THE HALF INCH
TO INCH RANGE WILL MOSTLY GET TRAPPED IN THE SNOW PACK AND THAT`S
NOT GOOD NEWS BECAUSE THE ADDED WEIGHT TO THE SNOWPACK WILL LIKELY
RESULT IN MORE ROOF COLLAPSES. PONDING ON ROADS DUE TO CLOGGED STORM
DRAINS WILL ALSO BE AN ISSUES. MODELS SNOW SFC DEWPOINTS RISING
ABOVE FREEZING LATE IN THE DAY AND THAT`S WHEN VISIBILITIES WILL
DECREASE THE MOST.
ALONG WITH THE WARMER AIR WILL COME INCREASED INSTABILITY. ELEVATED
LI`S ARE BELOW 0C AND MUCAPE RISES TO 500 J/KG. GIVEN SHEAR VALUES
OVER 60KTS...WE`LL LIKELY SEE THUNDERSTORMS DEVELOP. THE BEST CHANCE
FOR STRONG TO SEVERE STORMS WILL BE JUST SOUTH OF THE CWA.
AN OCCLUDED FRONT WILL SWEEP IN FROM THE WEST THURSDAY EVENING.
STRONG WEST WINDS WILL DEVELOP AND GUST TO 40-45 MPH AND COLDER AIR
WILL MOVE BACK INTO THE CWA. SNOW SHOWERS AND COLDER TEMPERATURES
ARE EXPECTED FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 AM EST WED FEB 19 2014
THE LONG TERM PERIOD WILL FEATURE GENERALLY QUIET WEATHER WITH BELOW
NORMAL TEMPERATURES AS A BROAD UPPER TROUGH REMAINS FIRMLY ANCHORED
OVER MOST OF CANADA AND THE NORTHERN AND EASTERN UNITED STATES. THE
PERSISTENT COLD CYCLONIC FLOW WILL PROMOTE OCCASIONAL LIGHT LAKE
EFFECT SNOW SHOWER ACTIVITY BUT NO SIGNIFICANT ACCUMULATIONS ARE
EXPECTED. CLIPPER TYPE SHORTWAVES DIVING THROUGH THE NORTHWEST FLOW
ALOFT COULD BRING BRIEF PERIODS SNOW SHOWER ENHANCEMENT BUT AGAIN NO
MAJOR SYSTEMS ARE FORESEEN AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1155 PM EST TUE FEB 18 2014
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH WEDNESDAY. A COLD FRONT
COULD BRING SOME BRIEF MVFR CEILINGS LATE TONIGHT BUT THE CHANCES
WERE LOW ENOUGH TO LEAVE OUT OF THE FORECAST. SOUTHWEST WINDS WILL
GO NORTHWEST BEHIND THE FRONT EARLY WEDNESDAY AND REMAIN AROUND 10
KNOTS.
&&
.HYDROLOGY...
ISSUED AT 141 PM EST TUE FEB 18 2014
RAIN COULD BE HEAVY AT TIMES THURSDAY INTO THURSDAY NIGHT AS
TEMPERATURES WARM UP. UPWARDS OF AN INCH OF RAIN IS FORECASTED. WE
WILL SEE SOME RUNOFF WHICH MAY LEAD TO URBAN AND POOR DRAINAGE
FLOODING. THE WARM TEMPERATURES WILL LAST LESS THAN 24 HRS THEN WE
DROP BACK DOWN BELOW FREEZING. THUS IT APPEARS THAT NOT ENOUGH
RUNOFF WILL OCCUR TO TRIGGER WIDESPREAD FLOODING...INCLUDING ICE
BREAKUP AND JAMS. WILL NEED TO MONITOR THE SITUATION CLOSELY IN
THE COMING DAYS.
ICE JAMS IN RIVERS TEND TO FORM NEAR SHARP BENDS...IN SHALLOW
AREAS...AND NEAR OBSTRUCTIONS...LIKE BRIDGES AND ISLANDS. ICE
BREAKUP ON RIVERS CAN OCCUR WHENEVER THE RIVER STAGE RISES 1.5 TO 3
TIMES THE RIVER ICE THICKNESS. ICE JAMS ON RIVERS CAN RESULT IN
UNPREDICTABLE RAPID RISES ON RIVERS.
UNTIL THEN...LITTLE CHANGE IS EXPECTED ON AREA RIVERS AS ICE REMAINS
LARGELY LOCKED IN PLACE ACROSS MOST RIVERS AND STREAMS AS FLOW IS
NEAR NORMAL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...93
SHORT TERM...93
LONG TERM...MEADE
AVIATION...OSTUNO
HYDROLOGY...MJS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
636 AM EST WED FEB 19 2014
.SYNOPSIS...
A STORM SYSTEM MOVING ACROSS LAKE ERIE WILL BRING A WARM UP TO OUR
REGION TODAY AND THURSDAY. A STRONGER STORM WILL MOVE FROM THE
MIDWEST INTO LOWER CANADA THURSDAY NIGHT, BRINGING RAIN AND
ADDITIONAL WARM AIR TO NY AND PA.
&&
.NEAR TERM /THROUGH TONIGHT/...
STORM SYSTEM AND SHORTWAVE TRACKING ACROSS GREAT LAKES WILL BRING
PRECIPITATION TO OUR REGION THIS MORNING. TEMPERATURES FELL INTO
THE TEENS AND LOWER 20S, BUT HAVE ALREADY BEGUN TO STABILIZE AND
RISE IN SOME SPOTS. AS SOUTHERLY FLOW INCREASES AHEAD OF THE
APPROACHING STORM, TEMPERATURES WILL ACCELERATE UPWARD.
THERE ARE TWO BIG PROBLEMS WITH THE CURRENT FREEZING RAIN
SCENARIO. THE FIRST IS THAT THE ATMOSPHERE REMAINS VERY DRY, AND
THE RADAR IS VERY QUIET BACK INTO WESTERN PA AND EASTERN OHIO.
CONVECTIVE ELEMENTS HAVE FIRED OVER SOUTHERN OHIO, BUT RADAR
TRAJECTORY WOULD SUGGEST THEY WILL PASS WELL SOUTH OF OUR FA.
UPGLIDE SHOULD PRODUCE PRECIP FORMATION THIS MORNING, BUT THE
TIMING WILL LIKELY BE BETWEEN 13Z AND 15Z WHEN TEMPERATURES WILL
BE PUSHING NORTH OF 32F. LATEST RUC AND HRRR HAVE SUGGESTED BIG
REDUCTIONS IN QPF/POPS OVER THE FIRST HALF OF THE DAY, WHEN THE
FREEZING RAIN POTENTIAL EXISTS.
WE MAY NEED TO RECONSIDER THE ADVISORY. AT THIS POINT WE WILL LET
IT RIDE, AND HOPEFULLY HAVE A CLEAR ENOUGH RADAR PICTURE BY 5 AM
OR SO THAT WE CAN LEAVE NEXT SHIFT WITH A CONFIDENT FORECAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A RIDGE REBUILDS TONIGHT INTO THURSDAY, ALLOWING FOR AN OVERNIGHT
COOL DOWN BEFORE TEMPERATURES PUSH INTO THE 40S THURSDAY.
A VIGOROUS CYCLONE WILL ROTATE OUT OF THE MIDWEST INTO LOWER
CANADA THURSDAY NIGHT, DRAGGING A WARM FRONT ACROSS LAKE ERIE. DEW
POINTS WILL ALSO INCREASE, AND THERE IS THE POTENTIAL FOR SOME
OVERNIGHT FOG, WHICH IS AN EFFECTIVE SNOW PACK MELTER.
THE COMBINATION OF RUN OFF AND QPF IS NOT TOO ALARMING IN THIS
CASE, AND I WOULD NOT BE SURPRISED IF A LOT OF THE QPF IS ABSORBED
IN THE STILL THICK SNOW PACK.
THE MAIN RISK APPEARS TO BE FOR ICE BREAKING UP ON AREA STREAMS AND
CREEKS. THIS WOULD LEAD TO HIGHLY LOCALIZED ICE JAM ISSUES, MAKING
A WIDESPREAD FFA OVERKILL. WITH THIS EVENT STILL A SOLID 42 TO 54
HOURS OUT, SEE TOO MUCH RISK IN RUSHING IN WITH A FLAG THIS EARLY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
FRIDAY NIGHT THE SFC LOW AND ATTENDANT RAIN SHOWERS ARE EXPECTED TO
MOVE NORTH OF THE REGION AND A BRIEF DRY PERIOD WILL RETURN THROUGH
SATURDAY AFTERNOON. ANOTHER COLD FRONT IS EXPECTED TO MOVE THROUGH
THE CWA LATE SAT NIGHT/SUN MORNING BRINGING ANOTHER SHOT OF SNOW
SHOWERS AND COLDER AIR. COLD AIR WILL CONTINUE TO ADVECT INTO THE
REGION AND BY MONDAY MORNING AND 850MB TEMPS WILL FALL TO AROUND
NEGATIVE 18 DEGREES... THUS WE MAY SEE A WEAK LAKE EFFECT RESPONSE
AND SCATTERED SNOW SHOWERS MAY DEVELOP ACROSS THE REGION THROUGH
TUESDAY MORNING. A SFC RIDGE WILL START TO BUILD INTO THE REGION
TUES MORNING FROM THE SW WHICH WILL RESULT IN THE LAKE EFFECT
RESPONSE TO DIMINISH. AFTER TUESDAY GUIDANCE STARTS TO VARY
GREATLY BETWEEN EACH OTHER... AND DECIDED TO JUST KEEP 20 PERCENT
POPS ATTM AS AN ACTIVE PATTERN IS EXPECTED IN THE FAR EXTENDED AND
CONFIDENCE IS LOW ON WHICH MODEL TO FOLLOW.
DECIDED TO GO CLOSELY WITH WPC GUIDANCE WITH TEMPS THROUGH THE
EXTENDED. SAT TEMPS WILL STILL REMAIN IN THE UPR 30S TO MID 40S AS
THE COLD FRONT WONT MOVE THROUGH THE REGION UNTIL LATE SAT NIGHT.
SUNDAY THE COLD AIR WILL RETURN AND WINTER WILL MAKE ITS MARK YET
ONCE AGAIN. TUESDAY MORNING WILL BE PARTICULARLY COLD WITH LOWS
ACROSS CENTRAL NY AND NORTHEAST PA BEING IN THE SINGLE DIGITS.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
STRONG LTL SHRT WV AND SFC WV HAS DVLPD A CONCENTRATED AREA OF
PCPN OVER CNTRL PA THAT IS ZIPPING EAST THIS MRNG. THE MAJORITY OF
THIS PCPN WILL MISS THE NY SITES BUT WILL GIVE A BRIEF PD OF FZRA
TO AVP...AND PERHAPS BGM. OTRW...LGT PCPN WILL DVLP OVER THE NY
STATIONS AS THE LOW MVES NE TODAY RESULTING IN MAINLY MVFR CIGS
AND VSBYS. DRIER AIR MVES IN LTR THIS AFTN AND OVRNGT RETURNING
VFR CIGS AND VSBYS OVRNGT...WITH THE XCPTN OF RME WHERE SOME LAKE
MOISTURE MAY KEEP LWR CIGS.
OUTLOOK...
THU AFTN...POSSIBLE RESTRICTIONS IN MIXED PRECIP.
THU NGT...MVFR/IFR RESTRICTIONS POSSIBLE IN FOG/RAIN.
FRI...RESTRICTIONS POSSIBLE IN -RA.
SAT/SUN...MVFR/IFR RESTRICTIONS POSSIBLE IN SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR PAZ038>040-043-
044-047-048-072.
NY...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ022>025-044-
045-055>057-062.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...DJP
LONG TERM...KAH
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
733 AM EST WED FEB 19 2014
.SYNOPSIS...
A FAST MOVING UPPER LEVEL TROUGH WILL SLIDE ACROSS THE LOWER
GREAT LAKES AND NORTHERN MID-ATLANTIC STATES TODAY...WITH
SECONDARY SURFACE LOW DEVELOPMENT FROM THE SOUTHERN NEW ENGLAND
COAST INTO THE CANADIAN MARITIMES...SIMILAR TO YESTERDAY. A WEAK
AREA OF HIGH PRESSURE WILL MIGRATE OVER THE REGION TONIGHT INTO
EARLY THURSDAY BEHIND THE DEPARTING SYSTEM. A WARM FRONT WILL LIFT
NORTH ACROSS THE AREA THURSDAY NIGHT...BEFORE A STRONG COLD FRONT
SWEEPS THROUGH THE COMMONWEALTH ON FRIDAY. TEMPERATURES SHOULD
AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL INTO WEEKEND BEFORE
TRENDING COLDER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
**12Z UPDATE** MULTIPLE PTYPE SCENARIO PLAYING OUT WITH
SNOW/SLEET/FZRA MIX IN STATE COLLEGE. RUC 925-850MB WET BULB
TEMPS FAVOR THIS MIX FROM STATE COLLEGE NEWD TO THE LYCOMING
VALLEY AND ENDLESS MTNS. TO THE SOUTH...SLEET COULD MIX IN ALONG
RT 22 INTO THE MID SUSQ VLY. ELSEWHERE EXPECT A QUICK GLAZING OF
ICE. OVERALL...WET BULBS ARE PLAYING IN INTEGRAL ROLE IN
DETERMINING PTYPES...PER EARLIER FCST CONCERNS. MADE SOME MINOR
CHANGES TO ZR ADVY WITH ANOTHER UPDATE LKLY NEEDED SOON GIVEN
SPEED OF PCPN SHIELD.
INCREASING LG SCALE LIFT/500MB HGT FALLS ASSOC WITH APPROACHING
GRT LKS SHORTWAVE MID/UPPER LEVEL TROUGH...AND STG WARM AIR/THETAE
ADVECTION/ISENT LIFT ON NOSE OF 40+KT SWLY LLJ IS RESULTING IN
FAST-MOVG AREA OF PCPN ACRS SE OH/NW WV MOVG INTO SW PA NEAR PIT
AS OF 09Z. SHORT RANGE MESO MODELS BRING THIS PCPN INTO CENTRAL PA
DURING THE PRE-DAWN AND EARLY MORNING HOURS /EXTRAPOLATED TOA IS
APPROX 0930Z IN THE SW ZONES AND AROUND 12Z IN THE ERN
COUNTIES/...OVERSPREADING A COMPLEX LOW-LEVEL THERMAL PROFILE.
LATEST RUC DATA INDICATES 925-850MB TEMPS ARE ABOVE 0C ACRS THE
ENTIRE CWA...BUT THIS CHANGES FOR SOME AREAS AFT FACTORING IN WET
BULB EFFECTS GIVEN DRY AIR IN PLACE WITH RATHER LARGE DEWPT
DEPRESSIONS. TO FURTHER COMPLICATE MATTERS...SFC TEMPS VARY WIDELY
WITH CNTRL-ERN SITES CALM/DECOUPLED AND WRN SITES WEAKLY MIXED AOA
32F. TO GET A SENSE OF THIS GRADIENT...THE 08Z THE TEMP DIFF FROM
MGW TO SEG WAS 34 DEGREES...48F VS. 14F. THE LOCAL TEMP HERE AT
THE OFFICE IS AROUND 19-20F.
MADE NO CHANGES TO ZR ADVY HEADLINE COVERING NEARLY ALL OF THE
CWA. HOWEVER CONCERN IS FOR MULTIPLE PTYPE SCENARIO GIVEN
COMPLEXITY OF BLYR THERMAL STRUCTURE+WET BULB EFFECTS...WITH THE
GREATEST POTNL FOR AN INITIAL PERIOD OF SNOW (MOST LKLY SLEET)
ACRS NERN 1/2 OF THE CWA...ESPECIALLY THE ENDLESS MTN/SRN POCONO
REGION NE OF THE LYCOMING VALLEY/IPT. ANTICIPATE UPDATING THE WX
GRIDS ONCE THE PCPN TYPES START TO SHOW THEIR HAND OVER THE NEXT
1-3 HRS.
TEMPS SHOULD WARM ABOVE FZG BY MIDDAY THUS ENDING THE THREAT FOR
ZR. WILL NEED TO SEE IF MDLS ARE TOO AGGRESSIVE IN WARMING TEMPS
GIVEN THE INITIAL WET BULBING AT THE ONSET OF PCPN. TEMPS SHOULD
START TO WARM ONCE WINDS SHIFT TO THE WEST BEHIND OCCLD FRNT. ONCL
LGT RAIN WILL CONTINUE INTO THE EARLY AFTN WITH THE HIGHEST POPS
OVER THE ERN ZONES BASED ON A CONSENSUS BLEND OF MDL QPFS...AND
NEAR SECONDARY SFC LOW DEVELOPING INVOF THE NJ COAST. A RAIN/SNOW
MIX IS POSSIBLE OVER THE NW MTNS AS COLDER AIR ALOFT ARRIVES ON
THE BACKSIDE OF THE SHORTWAVE TROUGH.
PCPN ENDS FROM SW TO NE BY THIS EVE AS HIGH PRES MIGRATES EWD FROM
THE UPPER OH VLY INTO PA...PROVIDING DRY WX FOR THE OVERNIGHT PD.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
A STRONG MID-LVL TROUGH CROSSING THE PLAINS STATES THURS IS FCST
TO TAKE ON A NEGATIVE TILT AS IT REACHES THE UPPER GRT LKS AND
MS/OH VLYS THURS NGT. AT THE SFC...HIGH PRES WILL SHIFT OFF THE
MID-ATL COAST EARLY THURS AS A WARM FRONT...EXTENDING EWD FROM
DEEPENING SFC LOW MOVG NNEWD FROM SERN KN TO LK SUPERIOR BY THE
END OF THE PD...LIFTS NWD ACRS THE AREA BY 00Z FRI. 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 LINE OF LOW-TOPPED CONVECTION WHICH
COULD REACH THE WRN ALLEGHENIES EARLY FRI MORNING.
QUESTION FOR THURS WILL BE THE EXTENT OF THE LLVL CAD PATTERN
GIVEN THE EXPECTED ONSLAUGHT OF LLVL WAA IN ADVANCE OF DYNAMIC
MIDWEST SYSTEM. THE HIRES NAM SHOWS NELY AGEO WINDS HOLDING SFC
TEMPS IN THE 35-40F RANGE WITH SOME OVERRUNNING PCPN SPREADING
INTO NWRN SECTIONS. SREF DATA SHOWS THE DOMINANT PTYPES AS RAIN
WITH VERY LOW PROBS FOR FROZEN/FZG PCPN IN THE N-CNTRL MTNS/N OF
I-80. IN GENERAL..STAYED VERY CLOSE TO CONSENSUS BLEND FOR MOST
ELEMENTS...WHICH FAVORED DAYTIME TEMPS AROUND 40F AND CATEGORICAL
POPS ACRS THE FAR NW ZONES THURS NGT. SPC DAY 2+3 OUTLOOKS PLACES
THE AREA IN GENERAL RISK HOWEVER MAY NEED TO ADD ENHANCED WORDING
IN HWO DUE TO POSSIBLE NCFRB/LOW TOPPED SQ LINE RACING ACRS THE
AREA DURING THE PRE-DAWN AND MORNING HOURS FRI. 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
SNOWMELT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
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.
BROAD TROUGH DEVELOPS ACROSS EASTERN 2/3RDS OF U.S. FOR THE
WEEKEND...GIVING US A SLOW AND STEADY RETURN BACK TO SLIGHTLY
BELOW NORMAL TEMPERATURES. WEAK FRONT PUSHES THROUGH MID-WEEKEND
THAT MAY BRING LIGHT ACCUMS OF SNOW. OTHERWISE...NO BIG SYSTEMS ON
THE HORIZON. SNOWFLAKES WILL LINGER OVER THE WESTERN/NORTHERN
HIGHER TERRAIN IN PERSISTENT NW/W FLOW.
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 /12Z WEDNESDAY THROUGH SUNDAY/...
BANDS OF MIXED PRECIPITATION CONTINUE TO MOVE ACROSS CENTRAL PA
THIS MORNING. THE INITIAL EDGE IS SNOW...BUT QUICKLY TRANSITIONING
TO A SLEET...FREEZING RAIN MIX AND THEN INTO FREEZING RAIN. THIS
BAND WILL BE HEAVY AT TIMES...AND MOVING SOUTHWEST TO NORTHEAST.
MVFR TO IFR CONDITIONS WILL BE POSSIBLE AT ALL TAF SITES THROUGH
18Z. THE CENTRAL AND WESTERN TAF SITES WILL IMPROVE LATE MORNING
TO EARLY AFTERNOON. LNS AND MDT WILL HAVE MVFR LINGER INTO MID
AFTERNOON. THIS WILL BE FOLLOWED BY A COOLER AND DRIER NW FLOW IN
THE WAKE OF THE FRONT. THERE COULD BE SOME LINGERING MVFR/IFR IN
SCATTERED RAIN OR SNOW SHOWERS...BUT THESE WILL BE VERY BRIEF AND
CONFINED TO THE WESTERN MOUNTAINS.
LLWS WILL BE ASSOCIATED WITH THIS LINE...WITH WIND SHEAR OF UP TO
50KTS POSSIBLE AT 020KFT AT JST...UNV...IPT AND AOO THROUGH 16Z.
OUTLOOK...
THU...MVFR/IFR LIKELY WITH SHOWERS AND FOG.
FRI...SHRA/REDUCED CIGS LIKELY.
SAT...NO SIG WX EXPECTED.
SUN...MVFR/SCT SHSN NW. MAINLY VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR PAZ006-012-018-
019-025>028-037-041-042-045-046-049>053-056>059.
FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ005-
010-011-017-024-033.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
PAZ034>036-063>066.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...RXR
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
702 AM EST WED FEB 19 2014
.SYNOPSIS...
A FAST MOVING UPPER LEVEL TROUGH WILL SLIDE ACROSS THE LOWER
GREAT LAKES AND NORTHERN MID-ATLANTIC STATES TODAY...WITH
SECONDARY SURFACE LOW DEVELOPMENT FROM THE SOUTHERN NEW ENGLAND
COAST INTO THE CANADIAN MARITIMES...SIMILAR TO YESTERDAY. A WEAK
AREA OF HIGH PRESSURE WILL MIGRATE OVER THE REGION TONIGHT INTO
EARLY THURSDAY BEHIND THE DEPARTING SYSTEM. A WARM FRONT WILL LIFT
NORTH ACROSS THE AREA THURSDAY NIGHT...BEFORE A STRONG COLD FRONT
SWEEPS THROUGH THE COMMONWEALTH ON FRIDAY. TEMPERATURES SHOULD
AVERAGE NEAR OR SLIGHTLY ABOVE NORMAL INTO WEEKEND BEFORE
TRENDING COLDER INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
**12Z UPDATE** MULTIPLE PTYPE SCENARIO PLAYING OUT WITH
SNOW/SLEET/FZRA MIX IN STATE COLLEGE. RUC 925-850MB WET BULB
TEMPS FAVOR THIS MIX FROM STATE COLLEGE NEWD TO THE LYCOMING
VALLEY AND ENDLESS MTNS. TO THE SOUTH...SLEET COULD MIX IN ALONG
RT 22 INTO THE MID SUSQ VLY. ELSEWHERE EXPECT A QUICK GLAZING OF
ICE. OVERALL...WET BULBS ARE PLAYING IN INTEGRAL ROLE IN
DETERMINING PTYPES...PER EARLIER FCST CONCERNS. MADE SOME MINOR
CHANGES TO ZR ADVY WITH ANOTHER UPDATE LKLY NEEDED SOON GIVEN
SPEED OF PCPN SHIELD.
INCREASING LG SCALE LIFT/500MB HGT FALLS ASSOC WITH APPROACHING
GRT LKS SHORTWAVE MID/UPPER LEVEL TROUGH...AND STG WARM AIR/THETAE
ADVECTION/ISENT LIFT ON NOSE OF 40+KT SWLY LLJ IS RESULTING IN
FAST-MOVG AREA OF PCPN ACRS SE OH/NW WV MOVG INTO SW PA NEAR PIT
AS OF 09Z. SHORT RANGE MESO MODELS BRING THIS PCPN INTO CENTRAL PA
DURING THE PRE-DAWN AND EARLY MORNING HOURS /EXTRAPOLATED TOA IS
APPROX 0930Z IN THE SW ZONES AND AROUND 12Z IN THE ERN
COUNTIES/...OVERSPREADING A COMPLEX LOW-LEVEL THERMAL PROFILE.
LATEST RUC DATA INDICATES 925-850MB TEMPS ARE ABOVE 0C ACRS THE
ENTIRE CWA...BUT THIS CHANGES FOR SOME AREAS AFT FACTORING IN WET
BULB EFFECTS GIVEN DRY AIR IN PLACE WITH RATHER LARGE DEWPT
DEPRESSIONS. TO FURTHER COMPLICATE MATTERS...SFC TEMPS VARY WIDELY
WITH CNTRL-ERN SITES CALM/DECOUPLED AND WRN SITES WEAKLY MIXED AOA
32F. TO GET A SENSE OF THIS GRADIENT...THE 08Z THE TEMP DIFF FROM
MGW TO SEG WAS 34 DEGREES...48F VS. 14F. THE LOCAL TEMP HERE AT
THE OFFICE IS AROUND 19-20F.
MADE NO CHANGES TO ZR ADVY HEADLINE COVERING NEARLY ALL OF THE
CWA. HOWEVER CONCERN IS FOR MULTIPLE PTYPE SCENARIO GIVEN
COMPLEXITY OF BLYR THERMAL STRUCTURE+WET BULB EFFECTS...WITH THE
GREATEST POTNL FOR AN INITIAL PERIOD OF SNOW (MOST LKLY SLEET)
ACRS NERN 1/2 OF THE CWA...ESPECIALLY THE ENDLESS MTN/SRN POCONO
REGION NE OF THE LYCOMING VALLEY/IPT. ANTICIPATE UPDATING THE WX
GRIDS ONCE THE PCPN TYPES START TO SHOW THEIR HAND OVER THE NEXT
1-3 HRS.
TEMPS SHOULD WARM ABOVE FZG BY MIDDAY THUS ENDING THE THREAT FOR
ZR. WILL NEED TO SEE IF MDLS ARE TOO AGGRESSIVE IN WARMING TEMPS
GIVEN THE INITIAL WET BULBING AT THE ONSET OF PCPN. TEMPS SHOULD
START TO WARM ONCE WINDS SHIFT TO THE WEST BEHIND OCCLD FRNT. ONCL
LGT RAIN WILL CONTINUE INTO THE EARLY AFTN WITH THE HIGHEST POPS
OVER THE ERN ZONES BASED ON A CONSENSUS BLEND OF MDL QPFS...AND
NEAR SECONDARY SFC LOW DEVELOPING INVOF THE NJ COAST. A RAIN/SNOW
MIX IS POSSIBLE OVER THE NW MTNS AS COLDER AIR ALOFT ARRIVES ON
THE BACKSIDE OF THE SHORTWAVE TROUGH.
PCPN ENDS FROM SW TO NE BY THIS EVE AS HIGH PRES MIGRATES EWD FROM
THE UPPER OH VLY INTO PA...PROVIDING DRY WX FOR THE OVERNIGHT PD.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
A STRONG MID-LVL TROUGH CROSSING THE PLAINS STATES THURS IS FCST
TO TAKE ON A NEGATIVE TILT AS IT REACHES THE UPPER GRT LKS AND
MS/OH VLYS THURS NGT. AT THE SFC...HIGH PRES WILL SHIFT OFF THE
MID-ATL COAST EARLY THURS AS A WARM FRONT...EXTENDING EWD FROM
DEEPENING SFC LOW MOVG NNEWD FROM SERN KN TO LK SUPERIOR BY THE
END OF THE PD...LIFTS NWD ACRS THE AREA BY 00Z FRI. 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 LINE OF LOW-TOPPED CONVECTION WHICH
COULD REACH THE WRN ALLEGHENIES EARLY FRI MORNING.
QUESTION FOR THURS WILL BE THE EXTENT OF THE LLVL CAD PATTERN
GIVEN THE EXPECTED ONSLAUGHT OF LLVL WAA IN ADVANCE OF DYNAMIC
MIDWEST SYSTEM. THE HIRES NAM SHOWS NELY AGEO WINDS HOLDING SFC
TEMPS IN THE 35-40F RANGE WITH SOME OVERRUNNING PCPN SPREADING
INTO NWRN SECTIONS. SREF DATA SHOWS THE DOMINANT PTYPES AS RAIN
WITH VERY LOW PROBS FOR FROZEN/FZG PCPN IN THE N-CNTRL MTNS/N OF
I-80. IN GENERAL..STAYED VERY CLOSE TO CONSENSUS BLEND FOR MOST
ELEMENTS...WHICH FAVORED DAYTIME TEMPS AROUND 40F AND CATEGORICAL
POPS ACRS THE FAR NW ZONES THURS NGT. SPC DAY 2+3 OUTLOOKS PLACES
THE AREA IN GENERAL RISK HOWEVER MAY NEED TO ADD ENHANCED WORDING
IN HWO DUE TO POSSIBLE NCFRB/LOW TOPPED SQ LINE RACING ACRS THE
AREA DURING THE PRE-DAWN AND MORNING HOURS FRI. 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
SNOWMELT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
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.
BROAD TROUGH DEVELOPS ACROSS EASTERN 2/3RDS OF U.S. FOR THE
WEEKEND...GIVING US A SLOW AND STEADY RETURN BACK TO SLIGHTLY
BELOW NORMAL TEMPERATURES. WEAK FRONT PUSHES THROUGH MID-WEEKEND
THAT MAY BRING LIGHT ACCUMS OF SNOW. OTHERWISE...NO BIG SYSTEMS ON
THE HORIZON. SNOWFLAKES WILL LINGER OVER THE WESTERN/NORTHERN
HIGHER TERRAIN IN PERSISTENT NW/W FLOW.
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 /12Z WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE...CLEAR SKIES...LIGHT WINDS AND SNOWPACK HAVE ALLOWED
FOR FOG/MIST ACROSS SOUTHEASTERN AND CENTRAL PA OVERNIGHT. THE
THICKEST FOG WAS AT LNS...AND THAT HAS SINCE LIFTED. THERE IS A
CHANCE FOR FOG AT LNS BETWEEN 11Z-15Z...OUT AHEAD OF THE NEXT BAND
OF PRECIPITATION. EXPECT FOG/MIST AT UNV...MDT AND LNS AND SHOULD
CONTINUE THROUGH MID MORNING.
PRECIP ASSOCIATED WITH THE APPROACHING COLD FRONT WILL BEGIN
MOVING INTO SOUTHWESTERN AREAS AROUND OR JUST BEFORE
DAWN...PROBABLY IN THE FORM OF FREEZING RAIN/DRIZZLE OR A LIGHT
WINTRY MIX. MOST TERMINALS WILL LIKELY EXPERIENCE A LIGHT ICING
ISSUE FOR A FEW HOURS AS THE PRECIP MOVES INTO THE REGION. THE
THREAT FOR ICING SHOULD DIMINISH BY MID TO LATE MORNING AS
TEMPERATURES RECOVER SLOWLY ABOVE FREEZING. MVFR/IFR CAN BE
EXPECTED WITH THE COMBINATION OF THE MILDER AIR AND LIGHT PRECIP
MOVING IN OVER OUR DEEP SNOW PACK.
THE COLD FRONT SHOULD MOVE THROUGH THE AREA BY EARLY TO MID
AFTERNOON...FOLLOWED BY A COOLER AND DRIER NW FLOW IN THE WAKE OF
THE FRONT. THERE COULD BE SOME LINGERING MVFR/IFR IN SCATTERED
RAIN OR SNOW SHOWERS...BUT THESE WILL BE VERY BRIEF AND CONFINED
TO THE WESTERN MOUNTAINS.
OUTLOOK...
THU...MVFR/IFR LIKELY WITH SHOWERS AND FOG.
FRI...SHRA/REDUCED CIGS LIKELY.
SAT...NO SIG WX EXPECTED.
SUN...MVFR/SCT SHSN NW. MAINLY VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR PAZ006-012-018-
019-025>028-037-041-042-045-046-049>053-056>059.
FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR PAZ005-
010-011-017-024-033.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
PAZ034>036-063>066.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...RXR
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
613 AM CST WED FEB 19 2014
.UPDATE...
WE HAVE UPDATED THE FORECAST TO ISSUE A DENSE FOG ADVISORY FOR
AREAS GENERALLY ALONG AND WEST OF A LLANO TO NEW BRAUNFELS TO SAN
ANTONIO TO PLEASANTON LINE. LIGHT WINDS AND PLENTY OF LOW LEVEL
MOISTURE HAS LED TO PATCHY...DENSE FOG ACROSS ROUGHLY THE WESTERN
2/3 OF SOUTH CENTRAL TEXAS THIS MORNING. IMPROVING CONDITIONS ARE
EXPECTED AFTER 10 AM AS WINDS AND TEMPERATURES BEGIN TO INCREASE.
&&
.PREV DISCUSSION... /ISSUED 354 AM CST WED FEB 19 2014/
SHORT TERM (TODAY THROUGH THURSDAY)...
SURFACE OBSERVATIONS AND SATELLITE IMAGERY SHOW FOG AND LOW CLOUDS
ARE CURRENTLY IN PLACE ACROSS SOUTH CENTRAL TEXAS. BASED ON RECENT
TRENDS AND THE LATEST HI-RES RUC MODEL...WE HAVE INCLUDED A
MENTION OF PATCHY...DENSE FOG ACROSS THE HILL COUNTRY AND SOUTHERN
EDWARDS PLATEAU. THE FOG IS EXPECTED TO DECREASE BY MID-MORNING AS
SOUTHERLY WINDS AND DAYTIME HEATING COMMENCE. AFTERNOON
TEMPERATURES WILL WARM TO ABOVE NORMAL LEVELS TODAY... WITH HIGHS
RANGING FROM THE UPPER 80S ALONG THE RIO GRANDE TO UPPER 70S ALONG
THE HIGHWAY 77 CORRIDOR. MOIST CONDITIONS REMAIN IN PLACE TONIGHT
AND WE/LL CONTINUE TO MENTION FOG AND DRIZZLE ACROSS MOST AREAS. A
PACIFIC COLD FRONT WILL MOVE THROUGH THE REGION ON THURSDAY. IN
ADVANCE OF THE FRONT...CAN/T RULE OUT SOME LIGHT MORNING SHOWERS
ALONG AND EAST OF THE I-35 CORRIDOR. WE/LL ALSO CONTINUE TO
MENTION A SLIGHT CHANCE FOR AFTERNOON THUNDERSTORMS EAST OF I-35
AS THE COLD FRONT WILL BE ACROSS THIS REGION DURING PEAK HEATING.
THE COLD FRONT WILL ALSO BRING AN INCREASE IN FIRE WEATHER
CONCERNS FOR AREAS ALONG AND WEST OF I-35. PLEASE SEE THE BELOW
FIRE WEATHER SECTION FOR MORE INFORMATION.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
WINDS WILL DECREASE THURSDAY NIGHT AS SKIES REMAIN MOSTLY CLEAR.
THIS ALONG WITH DRY AIR WILL ALLOW TEMPERATURES TO DROP INTO THE
LOWER 30S ACROSS THE HILL COUNTRY TO THE MID 40S COASTAL PLAINS.
SOUTHERLY FLOW IN THE LOW-LEVELS RESUMES ON FRIDAY AS ZONAL FLOW
ALOFT PERSISTS. A WARMING TREND IS EXPECTED SATURDAY AS THE LATEST
MEDIUM RANGE MODELS SHOW A COLD FRONT REMAINING NORTH OF THE
REGION. THERE IS SOME DISAGREEMENT AMONG THE MEDIUM RANGE MODELS
WITH REGARDS TO THE SOUTHWARD PROGRESS OF THE COLD FRONT ON
SUNDAY. FOR NOW...WILL SHOW SOME SLIGHTLY COOLER TEMPERATURES
NORTH OF I-10...WITH LITTLE CHANGE ELSEWHERE. THE FLOW ALOFT OVER
THE WESTERN U.S. WILL AMPLIFY EARLY NEXT WEEK...BUT DOES NOT
CHANGE SIGNIFICANTLY ACROSS THE SOUTHERN PLAINS. THIS PATTERN DOES
FAVOR PERIODIC COLD FRONTS MOVING INTO THE REGION AND WE/LL SHOW
SOME NEAR TO BELOW NORMAL TEMPERATURES ON TUESDAY. SOME LIGHT
SHOWERS ARE POSSIBLE EARLY NEXT WEEK...BUT OVERALL AMOUNTS AND
PRECIPITATION CHANCES WILL REMAIN LOW.
FIRE WEATHER...
CRITICAL TO NEAR CRITICAL FIRE WEATHER CONDITIONS ARE LIKELY FOR
AREAS MAINLY ALONG AND WEST OF THE I-35 CORRIDOR THURSDAY
AFTERNOON IN THE WAKE OF A PACIFIC COLD FRONT. RELATIVE HUMIDITIES
WILL DROP INTO THE TEENS WITH NORTH WINDS OF 15 TO 25 MPH AND
GUSTY FOLLOWING THE FRONTAL PASSAGE. ELEVATED FIRE WEATHER
CONDITIONS ARE POSSIBLE FRIDAY AFTERNOON MAINLY ALONG AND WEST OF
THE I-35 CORRIDOR AS RELATIVE HUMIDITIES AGAIN FALL INTO THE
TEENS WITH SOUTHERLY WINDS OF 10 TO 15 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 64 81 43 72 / - - 20 - -
AUSTIN BERGSTROM INTL AIRPORT 79 61 81 36 71 / - - 20 - -
NEW BRAUNFELS MUNI AIRPORT 80 61 83 39 73 / - - 20 - -
BURNET MUNI AIRPORT 78 60 76 37 69 / - - 20 - -
DEL RIO INTL AIRPORT 88 58 86 43 74 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 79 62 78 38 69 / - - 20 - -
HONDO MUNI AIRPORT 85 59 86 40 75 / - - 10 0 -
SAN MARCOS MUNI AIRPORT 79 62 81 39 71 / - - 20 - -
LA GRANGE - FAYETTE REGIONAL 78 64 79 42 69 / - 10 20 10 -
SAN ANTONIO INTL AIRPORT 82 63 85 44 74 / - - 10 - -
STINSON MUNI AIRPORT 82 62 86 43 73 / - - 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING
FOR THE FOLLOWING COUNTIES: BANDERA...BASTROP...BEXAR...BLANCO...
BURNET...CALDWELL...COMAL...DIMMIT...EDWARDS...FRIO...GILLESPIE...
GUADALUPE...HAYS...KENDALL...KERR...KINNEY...LLANO...MAVERICK...
MEDINA...REAL...TRAVIS...UVALDE...VAL VERDE...WILLIAMSON...ZAVALA.
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BEXAR...BLANCO...COMAL...DIMMIT...
EDWARDS...FRIO...GILLESPIE...KENDALL...KERR...KINNEY...LLANO...
MAVERICK...MEDINA...REAL...UVALDE...VAL VERDE...ZAVALA.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...24
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
532 AM CST WED FEB 19 2014
.AVIATION...
FOG AND LOW CLOUDS WILL COVER THE AREA THIS MORNING. VIS LOOKS TO
BE THE DRIVING FACTOR THIS MORNING. LIFR TO VLIFR VIS IS LIKELY AT
THE AUSTIN AND SAN ANTONIO TERMINALS THROUGH LATE MORNING. DRT
WILL SEE VIS DOWN TO IFR. THERE IS A CHANCE OF DRIZZLE. VIS WILL IMPROVE
THIS AFTERNOON AND CIGS WILL LIFT TO LOW VFR. WINDS WILL PICK UP
TO 10 TO 15 KTS DURING THE AFTERNOON AND STAY UP THROUGH THE
EVENING. STRONGER WINDS SHOULD KEEP VIS BETTER THURSDAY
MORNING...BUT STILL EXPECTING MVFR VIS OVERNIGHT WITH IFR CIGS.
&&
.PREV DISCUSSION... /ISSUED 354 AM CST WED FEB 19 2014/
SHORT TERM (TODAY THROUGH THURSDAY)...
SURFACE OBSERVATIONS AND SATELLITE IMAGERY SHOW FOG AND LOW CLOUDS
ARE CURRENTLY IN PLACE ACROSS SOUTH CENTRAL TEXAS. BASED ON RECENT
TRENDS AND THE LATEST HI-RES RUC MODEL...WE HAVE INCLUDED A
MENTION OF PATCHY...DENSE FOG ACROSS THE HILL COUNTRY AND SOUTHERN
EDWARDS PLATEAU. THE FOG IS EXPECTED TO DECREASE BY MID-MORNING AS
SOUTHERLY WINDS AND DAYTIME HEATING COMMENCE. AFTERNOON
TEMPERATURES WILL WARM TO ABOVE NORMAL LEVELS TODAY... WITH HIGHS
RANGING FROM THE UPPER 80S ALONG THE RIO GRANDE TO UPPER 70S ALONG
THE HIGHWAY 77 CORRIDOR. MOIST CONDITIONS REMAIN IN PLACE TONIGHT
AND WE/LL CONTINUE TO MENTION FOG AND DRIZZLE ACROSS MOST AREAS. A
PACIFIC COLD FRONT WILL MOVE THROUGH THE REGION ON THURSDAY. IN
ADVANCE OF THE FRONT...CAN/T RULE OUT SOME LIGHT MORNING SHOWERS
ALONG AND EAST OF THE I-35 CORRIDOR. WE/LL ALSO CONTINUE TO
MENTION A SLIGHT CHANCE FOR AFTERNOON THUNDERSTORMS EAST OF I-35
AS THE COLD FRONT WILL BE ACROSS THIS REGION DURING PEAK HEATING.
THE COLD FRONT WILL ALSO BRING AN INCREASE IN FIRE WEATHER
CONCERNS FOR AREAS ALONG AND WEST OF I-35. PLEASE SEE THE BELOW
FIRE WEATHER SECTION FOR MORE INFORMATION.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
WINDS WILL DECREASE THURSDAY NIGHT AS SKIES REMAIN MOSTLY CLEAR.
THIS ALONG WITH DRY AIR WILL ALLOW TEMPERATURES TO DROP INTO THE
LOWER 30S ACROSS THE HILL COUNTRY TO THE MID 40S COASTAL PLAINS.
SOUTHERLY FLOW IN THE LOW-LEVELS RESUMES ON FRIDAY AS ZONAL FLOW
ALOFT PERSISTS. A WARMING TREND IS EXPECTED SATURDAY AS THE LATEST
MEDIUM RANGE MODELS SHOW A COLD FRONT REMAINING NORTH OF THE
REGION. THERE IS SOME DISAGREEMENT AMONG THE MEDIUM RANGE MODELS
WITH REGARDS TO THE SOUTHWARD PROGRESS OF THE COLD FRONT ON
SUNDAY. FOR NOW...WILL SHOW SOME SLIGHTLY COOLER TEMPERATURES
NORTH OF I-10...WITH LITTLE CHANGE ELSEWHERE. THE FLOW ALOFT OVER
THE WESTERN U.S. WILL AMPLIFY EARLY NEXT WEEK...BUT DOES NOT
CHANGE SIGNIFICANTLY ACROSS THE SOUTHERN PLAINS. THIS PATTERN DOES
FAVOR PERIODIC COLD FRONTS MOVING INTO THE REGION AND WE/LL SHOW
SOME NEAR TO BELOW NORMAL TEMPERATURES ON TUESDAY. SOME LIGHT
SHOWERS ARE POSSIBLE EARLY NEXT WEEK...BUT OVERALL AMOUNTS AND
PRECIPITATION CHANCES WILL REMAIN LOW.
FIRE WEATHER...
CRITICAL TO NEAR CRITICAL FIRE WEATHER CONDITIONS ARE LIKELY FOR
AREAS MAINLY ALONG AND WEST OF THE I-35 CORRIDOR THURSDAY
AFTERNOON IN THE WAKE OF A PACIFIC COLD FRONT. RELATIVE HUMIDITIES
WILL DROP INTO THE TEENS WITH NORTH WINDS OF 15 TO 25 MPH AND
GUSTY FOLLOWING THE FRONTAL PASSAGE. ELEVATED FIRE WEATHER
CONDITIONS ARE POSSIBLE FRIDAY AFTERNOON MAINLY ALONG AND WEST OF
THE I-35 CORRIDOR AS RELATIVE HUMIDITIES AGAIN FALL INTO THE
TEENS WITH SOUTHERLY WINDS OF 10 TO 15 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 64 81 43 72 / - - 20 - -
AUSTIN BERGSTROM INTL AIRPORT 79 61 81 36 71 / - - 20 - -
NEW BRAUNFELS MUNI AIRPORT 80 61 83 39 73 / - - 20 - -
BURNET MUNI AIRPORT 78 60 76 37 69 / - - 20 - -
DEL RIO INTL AIRPORT 88 58 86 43 74 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 79 62 78 38 69 / - - 20 - -
HONDO MUNI AIRPORT 85 59 86 40 75 / - - 10 0 -
SAN MARCOS MUNI AIRPORT 79 62 81 39 71 / - - 20 - -
LA GRANGE - FAYETTE REGIONAL 78 64 79 42 69 / - 10 20 10 -
SAN ANTONIO INTL AIRPORT 82 63 85 44 74 / - - 10 - -
STINSON MUNI AIRPORT 82 62 86 43 73 / - - 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING
FOR THE FOLLOWING COUNTIES: BANDERA...BASTROP...BEXAR...BLANCO...
BURNET...CALDWELL...COMAL...DIMMIT...EDWARDS...FRIO...GILLESPIE...
GUADALUPE...HAYS...KENDALL...KERR...KINNEY...LLANO...MAVERICK...
MEDINA...REAL...TRAVIS...UVALDE...VAL VERDE...WILLIAMSON...ZAVALA.
DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BEXAR...BLANCO...COMAL...DIMMIT...
EDWARDS...FRIO...GILLESPIE...KENDALL...KERR...KINNEY...LLANO...
MAVERICK...MEDINA...REAL...UVALDE...VAL VERDE...ZAVALA.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...24
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1023 AM MST WED FEB 19 2014
.UPDATE...NO MAJOR UPDATES AT THIS TIME...THE LATEST RUC AND HRRR
MDLS STILL APPEAR TO BRING THE SNOW IN THE MOUNTAIN AREAS THIS
AFTERNOON. LATEST MTR OBS INDICATED SNOW AT OVER NRN UT AND SWRN
WY...WITH CIGS BKN-OVC090-100 AGL AT CRAIG AND MEEKER SO STILL
FAIRLY HIGH. CURRENT FORCAST OF DEVELOPING THIS AFTN STILL LOOKS
ON TRACK.
&&
.AVIATION...NOT MUCH CHANGE IN THE TAFS FM THE PRVS DISCUSSION.
VFR CIGS/VSBYS THROUGH 02Z THIS EVENING. CIGS LOWERING TO BLO 5KT
AFTER 03Z STILL LOOKS REASONABLE. RAIN OR RAIN/SNOW MIX POSSIBLE
THROUGH 06-07Z THEN IT SHUD TURN OVER THE SNOW. STILL ANTICIPATE
A SHORT LIVED PRECIPITATION EVENT WITH LITTLE IF ANY SNOWFALL
ACCUMULATION. BEST CHC OF SNOW WILL BE EAST OF THE DENVER AREA.
OVERALL TREND IN THE WIND FORECAST STILL LOOKS OKAY...WITH THE
STRONGEST WINDS FOLLOWING FROPA.
&&
.PREV DISCUSSION... /ISSUED 416 AM MST WED FEB 19 2014/
SHORT TERM...EXPECTING TODAY TO BE ANOTHER MILD ONE AS WE WILL BE
UNDER THE SOUTHWESTERLY FLOW AHEAD OF TONIGHTS APPROACHING UPPER
TROUGH. THE FLOW PATTERN IS VERY PROGRESSIVE...MOVING THE UPPER
LEVEL DISTURBANCE ACROSS THE STATE IN ABOUT 12 HOURS. QUASI-
GEOSTROPHIC DIAGNOSTICS PACKAGE SHOWS THE SYSTEM WILL HAVE QUITE A
BIT OF FORCING AS IT MOVES THROUGH...WHICH SHOULD DELIVER A PRETTY
GOOD SHOT OF SNOW TO THE MOUNTAIN AREAS. INTERACTION WITH THE
TERRAIN OF THE FRONT RANGE WILL LEAVE A MINIMUM IN PRECIPITATION
IN THE LEE OF THE FOOTHILLS...BUT PRECIPITATION COVERAGE SHOULD
THEN INCREASE AGAIN AS THE SYSTEM PROGRESSES EASTWARD. WILL
CONTINUE THE WINTER WEATHER ADVISORY IN THE MOUNTAINS FOR 4 TO 8
INCHES OF NEW SNOW...AND THE CHANCE POPS OR GREATER ON THE PLAINS
OVERNIGHT. TEMPERATURES ALONG THE I-25 CORRIDOR MAY BE WARM ENOUGH
EARLY IN THE EVENING THAT PRECIPITATION WILL BEGIN AS RAIN AND
THEN TRANSITION TO SNOW BY LATE EVENING. SURFACE COLD FRONT WILL
MOVE SOUTHWARD FROM THE WYOMING BORDER STARTING AROUND 00Z AND
THEN MOVE THROUGH DENVER BY 03Z. AS THE DISTURBANCE MOVES RAPIDLY
ACROSS THE COUNTY WARNING AREA...MOST PRECIPITATION ON THE PLAINS
SHOULD BE COMING TO AN END BY SUNRISE THURSDAY MORNING. MOUNTAINS
MAY STILL SEE SOME LINGERING SHOWERS AS MOISTURE GETS CAUGHT WEST
OF THE CONTINENTAL DIVIDE AND NORTHWEST FLOW HELPS PRODUCE
OROGRAPHIC SHOWERS.
LONG TERM...THE UPPER LEVEL TROUGH WILL BE EAST OF THE AREA THU
MORNING WITH FAIRLY STG NW FLOW ALOFT CONTINUING THRU THE AFTN.
CROSS-SECTIONS STILL SHOW DECENT MOISTURE IN THE MTNS IN THE
MORNING WITH FAVORABLE OROGRAPHICS SO MAY SEE ANOTHER FEW INCHES
OF SNOW WITH GUSTY WINDS AS WELL SO MAY NEED TO EXTEND ADVISORY
THRU THE LATE MORNING HOURS. OVER NERN CO IT WILL BE DRY BUT GUSTY
NW WINDS WILL OCCUR. BNDRY LAYER WINDS ARE STILL FCST IN THE 40-45
KT RANGE SO MAY SEE GUSTS UP TO 50 MPH AT TIMES. AT THIS TIME WILL
NOT ISSUE A HIGH WIND WATCH AS BELIEVE SPEEDS WILL STAY JUST BLO
WARNING CRITERIA. AS FOR HIGHS DECENT CAA IS FCST OVER THE AREA SO
WILL KEEP READINGS MAINLY IN THE UPPER 30S TO LOWER 40S.
FOR THU NIGHT AND FRI NWLY FLOW ALOFT WILL REMAIN OVER THE AREA AS A
FEW WK DISTURBANCES MOVE THRU IN THE FLOW. GFS CROSS-SECTIONS SHOW
MOISTURE DEPTH INCREASING IN THE MTNS THU EVENING AND CONTINUING
THRU FRI WITH FAVORABLE OROGRAPHICS. LAPSE RATES ARE INITIALLY IN
THE 5-6 C/KM RANGE HOWEVER THEY IMPROVE TO AROUND 7 C/KM BY AFTN.
IN ADDITION THERE WILL BE AN UPPER LEVEL JET OVERHEAD SO MAY SEE
SOME ENHANCEMENT OF SNOWFALL RATES FROM TIME TO TIME. MEANWHILE
ECMWF HAS LESS MOISTURE FOR THE SAME PERIOD WITH OVERALL SNOWFALL
AMOUNTS MUCH LIGHTER. THUS WILL HOLD OFF ON A WSA AND LET THE DAY
SHIFT SEE IF THE ECMWF AND GFS COME INTO BETTER AGREEMENT. AT LOWER
ELEVATIONS IT WILL REMAIN DRY HOWEVER THERE WILL BE A POTENTIAL FOR
HIGH WINDS THU NIGHT INTO FRI MORNING IN AND NR THE FOOTHILLS.
CROSS MTN FLOW INCREASES TO 60-70 KT THU NIGHT WITH SOME HINT OF A
MTN WAVE. HOWEVER AS WE HAVE SEEN THE LAST SEVERAL EVENTS THE
STRONGER WIND GUSTS HAVE BEEN RATHER SPORADIC AND NOT THAT
WIDESPREAD SO WE SHALL SEE HOW THIS EVENT UNFOLDS. AS FOR HIGHS ON
FRI WITH SOME WARMING IS SHOWN IN THE 850-700 MB LAYER SO WILL
TWEAK HIGHS INTO THE 45 TO 50 DEGREE RANGE OVER NERN CO.
BY FRI NIGHT AND SAT THERE IS LITTLE CHANGE TO THE OVERALL PTRN AS
THE FLOW ALOFT REMAINS NWLY. BOTH THE ECMWF AND GFS SHOW VARYING
AMOUNTS OF MOISTURE AFFECTING THE MTNS HOWEVER LAPSE RATES ARE AOA 7
C/KM SO IF MOISTURE DEPTH REMAINS FAVORABLE CERTAINLY COULD SEE
DECENT ACUMULATIONS IN SOME AREAS. AT LOWER ELEVATIONS IT APPEARS A
CDFNT WILL MOVE INTO NERN CO BY MIDDAY WITH SOME UPSLOPE FLOW LATE
SAT AFTN INTO SAT NIGHT. BOTH THE ECMWF AND GFS DO SHOW SOME
POTENTIAL FOR PCPN OVER NERN CO AS UPPER LEVEL JET IS OVERHEAD AND
MOISTURE IMPROVES BY EVENING THUS WILL KEEP IN POPS FOR SAT NIGHT.
HIGHS ON SAT OVER THE PLAINS WILL DEPEND ON HOW FAST FNT MOVES IN.
READINGS MAY STAY IN THE LOWER TO MID 30S NR THE WY-NE BORDER WHILE
FURTHER SOUTH HIGHS REACH THE LOWER 40S BEFORE THE FNT ARRIVES.
ON SUN THE FLOW ALOFT WILL REMAIN NWLY HOWEVER BOTH THE ECMWF AND
GFS SHOW MOISTURE DECREASING IN THE MTNS SO SNOW CHANCES SHOULD
DIMINISH. OVER NERN CO THE MAIN PUSH OF COLD AIR MAY STAY
GENERALLY TO THE EAST OF THE AREA SO WILL KEEP HIGHS MAINLY IN THE
UPPER 30S TO LOWER 40S.
FOR EARLY NEXT WEEK A BROAD UPPER LEVEL TROUGH WILL EXTEND FM THE
NRN PLAINS ACROSS THE GREAT LAKES WITH NRN CO BASICALLY STAYING IN
WNW FLOW ALOFT THRU TUE. THERE ARE LIKELY GOING TO BE SOME SURGES
OF SHALLOW COLDER AIR MOVING INTO NERN CO IN THIS TYPE OF PATTERN.
BOTH THE ECMWF AND GFS SHOW ONE DECENT SURGE COMING IN ON MON WHICH
COULD LEAD TO A CHC OF SOME LIGHT PCPN IF ENOUGH MOISTURE IS
AVAILABLE OVER NERN CO. HIGH TEMPS WILL BE A PROBLEM DEPENDING ON
TIMING OF THIS SURGE AS READINGS COULD STAY IN THE 30S IF IT ARRIVES
BY MORNING. IN THE MTNS BOTH THE ECMWF AND GFS KEEP THE BEST
MOISTURE OVER WY AT THIS TIME SO WILL ONLY MENTION SOME LOW POPS FOR
NOW.
AVIATION...AVIATION IMPACTS SHOULD BE MINIMAL THROUGH THE EARLY
EVENING. WINDS SHOULD TREND TOWARD SOUTHWESTERLY AND WESTERLY
THROUGH THE DAY...AHEAD OF THIS EVENINGS COLD FRONT. EVEN BEHIND
THE FRONT...WINDS SHOULD REMAIN OUT OF THE NORTHWEST AS THE UPPER
DISTURBANCE TRACKS ACROSS THE REGION QUICKLY. DOWNSLOPING WINDS
OVERNIGHT SHOULD HELP KEEP CEILINGS A LITTLE HIGHER...BUT CAN NOT
RULE OUT CEILINGS DROPPING BELOW 5000 FEET AGL FOR A FEW HOURS.
PRECIPITATION THAT FALLS MAY BE A MIX OF RAIN AND SNOW BEFORE 06Z.
AFTER 06Z...TEMPERATURES WILL BE COLD ENOUGH THAT ANY LINGERING
SHOWERS WILL BE IN THE FORM OF SNOW. SNOW ACCUMULATIONS SHOULD BE
MINIMAL SINCE THE SYSTEM WILL BE MOVING THROUGH SO QUICKLY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 5 AM MST
THURSDAY FOR COZ031-033-034.
&&
$$
SHORT TERM...COOPER
LONG TERM....99
AVIATION...99
AREA FORECAST DISCUSSION
NWS ALBANY NY
1236 PM EST WED FEB 19 2014
.SYNOPSIS...
ANOTHER FAST MOVING LOW PRESSURE SYSTEM WITH ITS
ASSOCIATED WARM AND COLD FRONTAL BOUNDARIES WILL BRING A PERIOD OF
SNOW AND RAIN TO THE REGION THIS AFTERNOON AND EVENING. MILDER AIR
WILL THEN MOVE INTO THE REGION BY THE END OF THE WEEK...ALONG WITH A
CHANCE OF RAIN SHOWERS...AS A STRONG COLD FRONT APPROACHES FROM THE
GREAT LAKES THURSDAY NIGHT AND FRIDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1235 PM...A BURST OF MODERATE TO HVY SNOWFALL HAS MOVED IN
ACROSS MOST OF ERN NY AND WRN NEW ENGLAND AHEAD OF A POTENT SHORT-
WAVE AND A WARM FRONT. SNOW RATES INCREASED TO 1-2"/HR AS A RESULT
OF THE RADAR RETURNS AND SOME GROUND TRUTH HAS SOME IN WITH SNOW
AMOUNTS UP TO 2" ALREADY IN RHINEBECK AND CATSKILL. SOME FREEZING
RAIN HAS ALSO BEEN REPORTED IN KPOU BASED ON THE ASOS. THE COLUMN
SHOULD COOL DOWN QUICKLY TO TRANSITION TO SNOW. AN SPS HAS BEEN
ISSUED TO TO COVER THE SNOW NORTH OF THE MID HUDSON RIVER
VALLEY...AND MENTION SOME FREEZING RAIN WITH A LIGHT ICE
ACCUMULATION FOR ERN ULSTER...DUTCHESS AND LITCHFIELD COUNTIES FOR
AN HOUR OR SO.
THE PCPN IS DUE TO STRONG ISENTROPIC LIFT AHEAD OF THE WARM
FRONT...AND THE STRONG UPWARD VERTICAL MOTION GENERATED BY THE
FRONT...AND THE SHORT-WAVE. SNOW AMOUNTS HAVE BEEN INCREASED TO
2-4 INCHES OVER SRN VT...THE BERKSHIRES...ERN CATSKILLS...GREENE
CTY...COLUMBIA CTY...PARTS OF THE SRN DACKS...AND THE LITCHFIELD HILLS.
EXPECT 1-2/1-3 INCHES IN MOST OTHER LOCATIONS.
THE LATEST RADAR TRENDS AND HRRR SHOWS THE BATCH OF SNOW AND MIXED
PCPN MOVING THROUGH BEFORE 3 PM ACROSS THE ENTIRE FCST AREA. THE
COLD FRONT WILL ARRIVE WITH ANOTHER ROUND OF RAIN TO SNOW SHOWERS
THIS EVENING.
CONTINUED MAX TEMPS...WITH MID/UPPER 30S IN VALLEY AREAS FROM
ALBANY SOUTH...AND GENERALLY LOWER/MID 30S TO THE NORTH...WITH
GENERALLY 20S TO LOWER 30S ACROSS HIGHER ELEVATIONS.
SOUTH TO SOUTHEAST WINDS WILL INCREASE INTO THE EARLY
AFTERNOON...SIMILAR TO YESTERDAY...WITH SOME GUSTS POSSIBLY
REACHING UP TO 30-35 MPH ACROSS PORTIONS OF SW VT...THE
BERKSHIRES...AND TACONICS...AND POSSIBLY UP TO 25-30 MPH WITHIN
THE CAPITAL REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...AS THE MAIN SHORTWAVE TROUGH PASSES THROUGH...ANOTHER
BURST OF PRECIPITATION IS EXPECTED. THE PRECIP SHOULD BE MORE
SHOWERY IN NATURE. IN FACT...MODEL SOUNDINGS ACTUALLY INDICATE RATHER
STEEP LAPSE RATES IN THE 700-500 HPA LAYER...WITH THE LATEST RAP13
INDICATING AS STEEP AS 8-8.5 C/KM. THESE STEEP LAPSE RATES...COMBINED
WITH ASCENT FROM THE APPROACHING/PASSING SHORTWAVE TROUGH...COULD
EVEN ALLOW FOR SOME ISOLATED THUNDERSTORMS ACROSS THE
REGION...SOME OF WHICH COULD PRODUCE GRAUPEL/SMALL HAIL. IN THE
WAKE OF THE TROUGH PASSAGE...STRONG WEST/NORTHWEST WINDS WILL
LIKELY DEVELOP...WITH ENHANCED FLOW DOWN THE MOHAWK RIVER
VALLEY/CAPITAL REGION AND BERKSHIRES EXPECTED. THIS COULD ALLOW
FOR SOME GUSTS TO REACH 35-40 MPH AT TIMES LATER THIS EVENING
UNTIL SHORTLY AFTER MIDNIGHT. SKIES SHOULD INITIALLY REMAIN MOSTLY
CLOUDY...BUT AS STRONG SUBSIDENCE AND SOME DOWNSLOPING
OCCURS...SKIES SHOULD TREND TO MOSTLY CLEAR WELL AFTER MIDNIGHT.
TEMPS WILL BE TRICKY...AS THERE COULD BE A WINDOW OF RAPID
DECOUPLING RIGHT AROUND OR EVEN AFTER DAYBREAK. HOWEVER...WIND AND
SOME CLOUDS SHOULD KEEP THIS FROM OCCURRING FOR MOST OF THE NIGHT.
SO...ALTHOUGH HAVE SIDED WITH THE COOLER MOS...DID NOT GO MUCH
COOLER. STILL EXPECT WIDESPREAD TEENS AND 20S ACROSS THE REGION.
THURSDAY...HIGH PRESSURE RIDGE WILL TRANSLATE EAST ACROSS THE
REGION. SKIES SHOULD BE MOSTLY SUNNY IN THE MORNING...WITH CLOUDS
INCREASING IN THE AFTERNOON. SOME LIGHT PRECIPITATION COULD REACH
FAR WESTERN AREAS TOWARD OR JUST AFTER SUNSET...MAINLY AS
RAIN...ALTHOUGH A RAIN/SLEET/SNOW MIX COULD OCCUR IN HIGHER
ELEVATIONS. EXPECT MAX TEMPS TO REACH THE UPPER 30S TO LOWER 40S
IN MOST VALLEY AREAS...AND LOWER/MID 30S FOR HIGHER ELEVATIONS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS POTENT STORM WRAPS UP ACROSS THE CENTRAL GREAT LAKES
REGION...EQUALLY IMPRESSIVE LOW LEVEL JET AND ISENTROPIC LIFT WILL
UNFOLD ACROSS UPSTATE NEW YORK THURSDAY NIGHT. THIS WILL ALLOW FOR
BANDS OF PRECIPITATION TO EVOLVE FROM SOUTH TO NORTH WITH THE PEAK
OF THE LOW LEVEL FORCING TAKING PLACE ACROSS THE ADIRONDACKS.
THERMAL PROFILES ACROSS THE REGION WILL BE TRANSITIONING WITHIN THE
WARM ADVECTION AS BOUNDARY LAYER TEMPS MAY STRUGGLE FOR A PERIOD OF
TIME. THIS SETS THE STAGE FOR SNOW MIXING WITH SLEET/FREEZING RAIN
IMPACTING MAINLY THE ADIRONDACKS AND SOUTHERN
GREENS...ALTHOUGH...COULD NOT RULE OUT SOME ISOLATED SHELTERED
LOCATIONS RECEIVING A WINTRY MIX IN THE MOHAWK AND CENTRAL-NORTHERN
HUDSON RIVER VALLEY. HOWEVER...THE STRENGTH OF THE WARM ADVECTION
WILL EVENTUALLY OVERCOME THE SHALLOW SUB FREEZING TEMPERATURES
FRIDAY MORNING FOR ALL OF THE PRECIPITATION TO BECOME RAIN.
ALONG WITH THE TEMPERATURES INCREASING...SO DOES THE DEWPOINT TO
ABOVE FREEZING. AS THIS WARMER AND MORE MOIST AIR ADVECTS OVER A
SNOW COVERED GROUND WOULD RESULT IN FOG AS WE WILL PLACE THIS IN THE
GRIDS. STRONG COLD FRONT WITH A FAIRLY TIGHT THERMAL GRADIENT FROM
+8C AT H850 OVER EASTERN NY TO -6C OVER WESTERN NY WILL QUICKLY MOVE
ACROSS THE REGION BY EARLY AFTERNOON PER THE LATEST NCEP MODEL SUITE
TIMING. AN INTERESTING NOTE HERE IS THE SHOWALTER VALUES FROM LATE
MORNING TO EARLY AFTERNOON DROP TO AROUND 0C WHICH SUGGESTS THE
WINDOW OF OPPORTUNITY FOR THUNDER. HOWEVER...WE WILL HOLD OFF ON
THE MENTION IN THE FORECAST/GRIDS UNTIL UPSTREAM TRENDS CAN BE
BETTER OBTAINED.
OVERALL...TEMPERATURES DURING THIS TIME FRAME WILL BE MAINLY
NON-DIURNAL DUE TO THE WARM ADVECTION THURSDAY NIGHT AND CONTINUING
TO RISE THROUGH FRIDAY.
THE LONG TERM WILL FEATURE A RETURN BACK TO WINTER TEMPERATURES AND
A VERY ACTIVE/FAST CYCLONIC FLOW ACROSS THE NORTHEAST CORRIDOR.
THE STORM THAT DEVELOPS OVER THE GREAT LAKES REGION SLOWLY FILLS AND
TRANSITIONS INTO A HUDSON/JAMES BAY LOW. WE WILL BE ON THE SOUTHERN
PERIPHERY OF THIS LOW WHICH KEEPS US RATHER UNSETTLED AND NEAR TO
BELOW NORMAL TEMPERATURES. THE TIMING OF SHORT WAVES WILL BE A
CHALLENGE IN THESE FAST FLOW REGIMES. PER THE GLOBAL MODELS...THE
FIRST WAVE ARRIVES SATURDAY WITH MAINLY THE EASTERN GREAT LAKES AND
SOME LAKE EFFECT SNOW IMPACTING PORTIONS OF THE ADIRONDACKS. THE
NEXT WAVE ARRIVES SUNDAY WITH A BIT MORE OF A SOUTHERN ROUTE. THIS
WAVE ATTEMPTS TO BE AN OVERACHIEVER PER THE ECMWF WITH THE GFS/GGEM
MUCH FLATTER AND MORE PROGRESSIVE. GIVEN THE RECENT TRACK RECORD OF
THE ECMWF...WE WILL PLACE SLIGHT CHANCE POPS FOR NOW.
LOOKING AHEAD INTO THE NEW WORK WEEK...THE HUDSON/JAMES BAY UPPER
LOW LOSES ITS GRIP AS WE MONITOR A POTENT PIECE OF ENERGY DIVE
SOUTHWARD FROM THE NORTHWEST TERRITORIES INTO THE INTERMOUNTAIN
WEST AND QUICKLY OUT ONTO THE CENTRAL PLAINS AND MID WEST BY
TUESDAY. THIS WILL REINTRODUCE THE CHANCE FOR ADDITIONAL WINTRY
PRECIPITATION LATE MONDAY INTO TUESDAY FOR THE ENTIRE CWFA.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
RATHER CHALLENGING IN THE NEAR TERM AS CLEAR SKIES WITH LIGHT WINDS
AND SNOW FROM EARLIER HAS RESULTED IN MVFR/IFR CONDITIONS AT KGFL
WITH OTHER TAF SITES HINTING AT THE POSSIBILITY. WE WILL PLACE A
TEMPO GROUP AT THIS TIME...AS WE MONITOR TRENDS AND UPSTREAM HIGH
AND MID LEVEL CLOUD COVER ADVECTING INTO THE REGION. THIS SHOULD
MINIMIZE THE FOG FROM SPREADING BUT IT WILL BE CLOSE.
AFTER SUNRISE...VISIBILITIES SHOULD IMPROVE AS WE WATCH THE NEXT
CLIPPER SYSTEM APPROACHING. THIS IS EXPECTED TO BRING ANOTHER
CHANCE FOR PRECIPITATION LATE THIS MORNING INTO THE AFTERNOON
HOURS. BOUNDARY LAYER TEMPERATURES WILL BE CLOSE TO RESULT IN
EITHER SN/RASN/RA. FOR NOW...WE FEEL KGFL WILL BE MAINLY SNOW WITH
A MIXTURE FURTHER SOUTH INTO KALB-KPSF AND TRANSITIONING TO ALL RAIN
KPOU. PRECIP SHOULD END THIS EVENING FROM WEST TO EAST RATHER
QUICKLY.
VARIABLE WINDS AT LESS THAN 6 KT WILL SWITCH TO A W-NW DIRECTION
BUT SWITCH TO A SOUTHERLY DIRECTION AND INCREASE TO AROUND 10 KTS
FOR WEDNESDAY MORNING...AND CONTINUE INTO THE AFTERNOON.
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.
&&
.HYDROLOGY...
SNOW DEPTHS ACROSS EAST CENTRAL NEW YORK AND ADJACENT WESTERN NEW
ENGLAND ARE GENERALLY FROM A FOOT TO THREE FEET. ALTHOUGH WE HAVE
WARMER TEMPERATURES IN THE FORECAST FOR THE LATTER PART OF THE
WEEK...EXCEPT FOR THURSDAY NIGHT...OVERNIGHT LOWS WILL BE AROUND OR
SLIGHTLY BELOW FREEZING WHICH SHOULD RESULT IN A SLOW MELT AND
HOPEFULLY MINIMIZE ANY FLOOD THREAT. RAINFALL TOTALS THURSDAY NIGHT
INTO FRIDAY MORNING ARE FORECAST TO GENERALLY BE IN THE QUARTER TO
HALF INCH RANGE...SO MUCH OF THIS RAINFALL SHOULD BE ABSORBED BY THE
CURRENT SNOWPACK.
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 25.7 INCHES THROUGH THE 16TH. THIS AMOUNT IS ONLY 0.3
INCHES FROM REACHING INTO THE TOP 10 FOR SNOWIEST FEBRUARYS SINCE
1885.
A LIGHT TO MODERATE SNOWFALL IS EXPECTED TUESDAY.
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. 27.5 INCHES 1899
8. 26.1 INCHES 1914
9. 26.0 INCHES 1958
10. 26.0 INCHES 1988
LOOKING AT THE SEASONAL SNOWFALL IT STANDS AT 62.8 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...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...KL/WASULA
NEAR TERM...KL/WASULA
SHORT TERM...KL
LONG TERM...BGM
AVIATION...BGM/NAS
HYDROLOGY...KL/GJM
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
413 PM CST WED FEB 19 2014
.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 22Z...
* NO CONCERNS IN THE NEAR TERM.
* WINTRY MIX OF PCPN BEGINNING DURG THE PRE-DAWN HOURS...LIKELY
SN/FZRA...THOUGH THERE IS A CHANCE THAT SOME IP COULD MIX IN
BRIEFLY. AMOUNT OF ICE ACCUMULATION IS UNCERTAIN.
* TIMING OF CHANGEOVER FROM WINTRY MIX TO ALL RAIN. LIKELY BY ARND
12Z...BUT EXACT TIMING IS STILL UNCERTAIN.
* VIS MAY DROP TO IFR...OR POSSIBLY LIFR...IN BR/FG BY LATE
MORNING OR EARLY AFTERNOON.
* CHANCE OF ISOLD/EMBEDDED TSRA LATE MORNING THROUGH EARLY
AFTERNOON UNTIL FRONTAL PASSAGE.
* WINDS SHIFTING TO SSWLY-SWLY BY EARLY AFTERNOON...STRENGTHENING
AND BECMG GUSTY TO ARND 30KT IN THE LATE AFTERNOON. GUSTS COULD
POSSIBLY BE EVEN HIGHER LATE AFTERNOON/EARLY EVENING.
KREIN/BMD
//DISCUSSION...UPDATED 18Z...UPDATED 1845Z...
QUIET CONDITIONS THROUGH LATE TONIGHT. CLEAR SKIES WILL GIVE WAY
TO INCREASING MID AND HIGH CLOUD AS A COMPLEX WEATHER SYSTEM
DEVELOPS OVER THE CENTRAL PLAINS AND CLOUD COVER BEGINS TO RACE
OUT AHEAD OF THE DOUBLE BARRELED LOW PRESSURE SYSTEM. OF MAIN
CONCERN TO NRN IL/NWRN INDIANA WILL BE THE TRACK AND DEVELOPMENT
OF THE SOUTHERN OF THE 2 LOWS...WHICH IS EXPECTED TO INITIALLY
DEVELOP OVER THE SOUTH HIGH PLAINS AND AND RAPIDLY DEEPEN AS IT
TRACKS THROUGH THE MIDDLE MISSISSIPPI VALLEY TO EASTERN WISCONSIN
BY EARLY TOMORROW EVENING.
THIS SYSTEM WILL BRING A COMPLEX WEATHER SCENARIO TO THE TERMINALS
WHICH WILL BE HIGHLY DEPENDANT ON THE EXACT TRACK OF THE
SYSTEM...AS WELL AS THE IMPACT OF THE DENSE SNOW PACK OVER THE
REGION. BASED ON THE CURRENTLY EXPECTED TRACK...AN ASSOCIATED WARM
FRONT WOULD LIFT NWD THROUGH THE REGION. WITH WARMER AIR ALOFT
OVERRIDING THE COLDER AIR AND SNOW PACK AT THE SFC...PCPN SHOULD
START OUT AS EITHER ALL SNOW...OR A WINTRY MIX OF
FZRA/IP/SN/RA...WHICH WILL BE HIGHLY DEPENDANT ON THE DEPTH AND
DURATION OF A SUB-FREEZING LAYER AT THE SFC...WITH THE DENSE
SNOWPACK POSSIBLY HELPING TO KEEP SFC TEMPS AT ARND THE FREEZING
MARK. THERE ARE PLEANTY OF QUESTIONS MARKS WITH THIS
SYSTEM...AMONG THEM BEING THE DURATION OF THE FREEZING AND FROZEN
PCPN TYPES. THE SYSTEM IS EXPECTED TO BE VERY FAST-MOVING...BUT
VERY DYNAMIC. THE SPEED OF THE SYSTEM WILL HELP LIMIT THE DURATION
OF THE FREEZING/FROZEN PCPN AND SNOW OR ICE ACCUMULATIONS WOULD BE
MINOR...BUT THE DYNAMICS OF THE SYSTEM COULD HELP GENERATE SOME
ADDITIONAL DYNAMIC COOLING...WHICH WOULD DELAY A CHAGEOVER FROM
SNOW TO FREEZING PCPN AND ADD TO THE SNOW ACCUMULATION TOTALS.
BEST ESTIMATION AT THIS POINT WOULD BE THAT ICE AND SNOW
ACCUMULATIONS WILL BE RELATIVELY MINOR...BUT ENOUGH TO HAVE A
SIGNIFICANT IMPACT ON OPERATIONS EVEN IF THE DURATION IS LIMITED
TO 2-3 HOURS. HAVE RELATIVELY HIGH CONFIDENCE THAT PCPN WILL
CHANGE OVER TO ALL RAIN AS THE WARM FRONT LIFTS NORTH OF THE
TERMINALS. HOWEVER...THIS WILL BRING THE NEXT SIGNIFICANT CONCERN
OF HEAVY RAIN WITH EMBEDDED THUNDERSTORMS. BASED ON THE CURRENTLY
ANTICIPATED TRACK OF THE SYSTEM...WITH THE MAIN SFC LOW PASSING
THROUGH FAR NWRN IL WOULD PUT THE TERMINAL AREAS INTO A WARM
SECTOR OF THE SYSTEM...FOLLOWED BY THE PASSAGE OF A STRONG COLD
FRONT. THE STRONGEST FORCING AND INSTABILITY SHOULD FOCUS THE MOST
EXTENSIVE AND STRONGEST THUNDERSTORMS TO THE SOUTHEAST OF THE
TERMINALS...BUT FORCING AND INSTABILITY SHOULD BE SUFFICIENT FOR
ISOLATED/EMBEDDED THUNDER FROM LATE MORNING AND THROUGH THE
AFTERNOON HOURS. IN ADDITION TO THE RAIN AND THUNDER
CONCERNS...ALSO HAVE CONCERN FOR THE POTENTIAL FOR DENSE FOG WITH
THE ADVECTION OF WARM/MOIST AIR OVER THE SNOW PACK...WHICH WILL
ALSO HAVE INCREASING MOISTURE CONTENT AS THE SNOW ABSORBS THE
FALLING RAIN. WITH HIGH DEWPOINT WARM AIR OVERSPREADING THE
SNOW...THERE IS A CONCERN THAT DENSE FOG COULD DEVELOP BY LATE
MORNING/EARLY AFTERNOON...EVEN WITH STRENGTHENING SELY-SLY WINDS.
HAVE LIMITED THE LOWER EXTENT OF THE VISBY TO 3/4SM TO 1SM FOR
TOMORROW...BUT THERE IS THE POTENTIAL FOR PERIODS OF VISBY
DROPPING TO 1/4SM IN FOG UNTIL THE PASSAGE OF THE STRONG COLD
FRONT TOMORROW EVENING.
THE THIRD CONCERN WILL THEN BECOME WINDS. SELY WINDS WILL BEGIN
TO INCREASE THROUGH THE MORNING WITH THE APPROACH OF THE COLD
FRONT...WITH SELY-SLY WINDS INCREASING AND BECMG GUSTY APPROACHING
30KT LATE THIS AFTERNOON. WHILE IT WILL BE AFTER THE CURRENT TAF
PERIOD...WINDS WILL SHIFT THROUGH SWLY TO WLY FOLLOWING THE FROPA
AND INCREASE FURTHER...POSSIBLY GUSTING TO 40KT EARLY TOMORROW
EVENING.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS THROUGH LATE TONIGHT.
* HIGH CONFIDENCE IN A PERIOD OF A WINTRY MIX OF PCPN DURG THE
EARLY MORNING HOURS...BUT LOWER CONFIDENCE IN TIMING AND
DURATION OF THE WINTRY MIX PCPN.
* HIGH CONFIDENCE THAT PCPN WILL CHANGE OVER TO ALL RAIN BY LATE
MORNING...BUT LOWER CONFIDENCE IN EXACT TIMING.
* MEDIUM CONFIDENCE IN WIND TRENDS.
* LOW TO MEDIUM CONFIDENCE IN VISBY TRENDS...ESPECIALLY RELATED TO
THE CHANCE FOR IFR/LIFR VIS IN FOG DEVELOPING LATE TOMORROW
MORNING INTO TOMORROW AFTERNOON.
KREIN/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...RAIN OR SNOW SHOWERS...WITH POSSIBLE MVFR
CONDITIONS. VERY STRONG SOUTHWEST WINDS OF 25 TO 35 MPH WITH GUSTS
UP TO 50 MPH
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF LIGHT SNOW.
TUESDAY...SLIGHT CHANCE OF LIGHT SNOW.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NO CONCERNS IN THE NEAR TERM.
* WINTRY MIX OF PCPN BEGINNING DURG THE PRE-DAWN HOURS...LIKELY
SN/FZRA...THOUGH THERE IS A CHANCE THAT SOME IP COULD MIX IN
BRIEFLY. AMOUNT OF ICE ACCUMULATION IS UNCERTAIN.
* TIMING OF CHANGEOVER FROM WINTRY MIX TO ALL RAIN. LIKELY BY ARND
12Z...BUT EXACT TIMING IS STILL UNCERTAIN.
* VIS MAY DROP TO IFR...OR POSSIBLY LIFR...IN BR/FG BY LATE
MORNING OR EARLY AFTERNOON.
* CHANCE OF ISOLD/EMBEDDED TSRA LATE MORNING THROUGH EARLY
AFTERNOON UNTIL FRONTAL PASSAGE.
* WINDS SHIFTING TO SSWLY-SWLY BY EARLY AFTERNOON...STRENGTHENING
AND BECMG GUSTY TO ARND 30KT IN THE LATE AFTERNOON. GUSTS COULD
POSSIBLY BE EVEN HIGHER LATE AFTERNOON/EARLY EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...UPDATED 1845Z...
QUIET CONDITIONS THROUGH LATE TONIGHT. CLEAR SKIES WILL GIVE WAY
TO INCREASING MID AND HIGH CLOUD AS A COMPLEX WEATHER SYSTEM
DEVELOPS OVER THE CENTRAL PLAINS AND CLOUD COVER BEGINS TO RACE
OUT AHEAD OF THE DOUBLE BARRELED LOW PRESSURE SYSTEM. OF MAIN
CONCERN TO NRN IL/NWRN INDIANA WILL BE THE TRACK AND DEVELOPMENT
OF THE SOUTHERN OF THE 2 LOWS...WHICH IS EXPECTED TO INITIALLY
DEVELOP OVER THE SOUTH HIGH PLAINS AND AND RAPIDLY DEEPEN AS IT
TRACKS THROUGH THE MIDDLE MISSISSIPPI VALLEY TO EASTERN WISCONSIN
BY EARLY TOMORROW EVENING.
THIS SYSTEM WILL BRING A COMPLEX WEATHER SCENARIO TO THE TERMINALS
WHICH WILL BE HIGHLY DEPENDANT ON THE EXACT TRACK OF THE
SYSTEM...AS WELL AS THE IMPACT OF THE DENSE SNOW PACK OVER THE
REGION. BASED ON THE CURRENTLY EXPECTED TRACK...AN ASSOCIATED WARM
FRONT WOULD LIFT NWD THROUGH THE REGION. WITH WARMER AIR ALOFT
OVERRIDING THE COLDER AIR AND SNOW PACK AT THE SFC...PCPN SHOULD
START OUT AS EITHER ALL SNOW...OR A WINTRY MIX OF
FZRA/IP/SN/RA...WHICH WILL BE HIGHLY DEPENDANT ON THE DEPTH AND
DURATION OF A SUB-FREEZING LAYER AT THE SFC...WITH THE DENSE
SNOWPACK POSSIBLY HELPING TO KEEP SFC TEMPS AT ARND THE FREEZING
MARK. THERE ARE PLEANTY OF QUESTIONS MARKS WITH THIS
SYSTEM...AMONG THEM BEING THE DURATION OF THE FREEZING AND FROZEN
PCPN TYPES. THE SYSTEM IS EXPECTED TO BE VERY FAST-MOVING...BUT
VERY DYNAMIC. THE SPEED OF THE SYSTEM WILL HELP LIMIT THE DURATION
OF THE FREEZING/FROZEN PCPN AND SNOW OR ICE ACCUMULATIONS WOULD BE
MINOR...BUT THE DYNAMICS OF THE SYSTEM COULD HELP GENERATE SOME
ADDITIONAL DYNAMIC COOLING...WHICH WOULD DELAY A CHAGEOVER FROM
SNOW TO FREEZING PCPN AND ADD TO THE SNOW ACCUMULATION TOTALS.
BEST ESTIMATION AT THIS POINT WOULD BE THAT ICE AND SNOW
ACCUMULATIONS WILL BE RELATIVELY MINOR...BUT ENOUGH TO HAVE A
SIGNIFICANT IMPACT ON OPERATIONS EVEN IF THE DURATION IS LIMITED
TO 2-3 HOURS. HAVE RELATIVELY HIGH CONFIDENCE THAT PCPN WILL
CHANGE OVER TO ALL RAIN AS THE WARM FRONT LIFTS NORTH OF THE
TERMINALS. HOWEVER...THIS WILL BRING THE NEXT SIGNIFICANT CONCERN
OF HEAVY RAIN WITH EMBEDDED THUNDERSTORMS. BASED ON THE CURRENTLY
ANTICIPATED TRACK OF THE SYSTEM...WITH THE MAIN SFC LOW PASSING
THROUGH FAR NWRN IL WOULD PUT THE TERMINAL AREAS INTO A WARM
SECTOR OF THE SYSTEM...FOLLOWED BY THE PASSAGE OF A STRONG COLD
FRONT. THE STRONGEST FORCING AND INSTABILITY SHOULD FOCUS THE MOST
EXTENSIVE AND STRONGEST THUNDERSTORMS TO THE SOUTHEAST OF THE
TERMINALS...BUT FORCING AND INSTABILITY SHOULD BE SUFFICIENT FOR
ISOLATED/EMBEDDED THUNDER FROM LATE MORNING AND THROUGH THE
AFTERNOON HOURS. IN ADDITION TO THE RAIN AND THUNDER
CONCERNS...ALSO HAVE CONCERN FOR THE POTENTIAL FOR DENSE FOG WITH
THE ADVECTION OF WARM/MOIST AIR OVER THE SNOW PACK...WHICH WILL
ALSO HAVE INCREASING MOISTURE CONTENT AS THE SNOW ABSORBS THE
FALLING RAIN. WITH HIGH DEWPOINT WARM AIR OVERSPREADING THE
SNOW...THERE IS A CONCERN THAT DENSE FOG COULD DEVELOP BY LATE
MORNING/EARLY AFTERNOON...EVEN WITH STRENGTHENING SELY-SLY WINDS.
HAVE LIMITED THE LOWER EXTENT OF THE VISBY TO 3/4SM TO 1SM FOR
TOMORROW...BUT THERE IS THE POTENTIAL FOR PERIODS OF VISBY
DROPPING TO 1/4SM IN FOG UNTIL THE PASSAGE OF THE STRONG COLD
FRONT TOMORROW EVENING.
THE THIRD CONCERN WILL THEN BECOME WINDS. SELY WINDS WILL BEGIN
TO INCREASE THROUGH THE MORNING WITH THE APPROACH OF THE COLD
FRONT...WITH SELY-SLY WINDS INCREASING AND BECMG GUSTY APPROACHING
30KT LATE THIS AFTERNOON. WHILE IT WILL BE AFTER THE CURRENT TAF
PERIOD...WINDS WILL SHIFT THROUGH SWLY TO WLY FOLLOWING THE FROPA
AND INCREASE FURTHER...POSSIBLY GUSTING TO 40KT EARLY TOMORROW
EVENING.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS THROUGH LATE TONIGHT.
* HIGH CONFIDENCE IN A PERIOD OF A WINTRY MIX OF PCPN DURG THE
EARLY MORNING HOURS...BUT LOWER CONFIDENCE IN TIMING AND
DURATION OF THE WINTRY MIX PCPN.
* HIGH CONFIDENCE THAT PCPN WILL CHANGE OVER TO ALL RAIN BY LATE
MORNING...BUT LOWER CONFIDENCE IN EXACT TIMING.
* MEDIUM CONFIDENCE IN WIND TRENDS.
* LOW TO MEDIUM CONFIDENCE IN VISBY TRENDS...ESPECIALLY RELATED TO
THE CHANCE FOR IFR/LIFR VIS IN FOG DEVELOPING LATE TOMORROW
MORNING INTO TOMORROW AFTERNOON.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...RAIN OR SNOW SHOWERS...WITH POSSIBLE MVFR
CONDITIONS. VERY STRONG SOUTHWEST WINDS OF 25 TO 35 MPH WITH GUSTS
UP TO 50 MPH
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF LIGHT SNOW.
TUESDAY...SLIGHT CHANCE OF LIGHT SNOW.
RODRIGUEZ
&&
.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.
IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...3 AM THURSDAY
TO 6 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...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 4 PM FRIDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
322 PM CST WED FEB 19 2014
.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 20Z...
* NO CONCERNS IN THE NEAR TERM.
* WINTRY MIX OF PCPN BEGINNING DURG THE PRE-DAWN HOURS...LIKELY
SN/FZRA...THOUGH THERE IS A CHANCE THAT SOME IP COULD MIX IN
BRIEFLY. AMOUNT OF ICE ACCUMULATION IS UNCERTAIN.
* TIMING OF CHANGEOVER FROM WINTRY MIX TO ALL RAIN. LIKELY BY ARND
12Z...BUT EXACT TIMING IS STILL UNCERTAIN.
* VIS MAY DROP TO IFR...OR POSSIBLY LIFR...IN BR/FG BY LATE
MORNING OR EARLY AFTERNOON.
* CHANCE OF ISOLD/EMBEDDED TSRA LATE MORNING THROUGH EARLY
AFTERNOON UNTIL FRONTAL PASSAGE.
* WINDS SHIFTING TO SSWLY-SWLY BY EARLY AFTERNOON...STRENGTHENING
AND BECMG GUSTY TO ARND 30KT IN THE LATE AFTERNOON. GUSTS COULD
POSSIBLY BE EVEN HIGHER LATE AFTERNOON/EARLY EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...UPDATED 1845Z...
QUIET CONDITIONS THROUGH LATE TONIGHT. CLEAR SKIES WILL GIVE WAY
TO INCREASING MID AND HIGH CLOUD AS A COMPLEX WEATHER SYSTEM
DEVELOPS OVER THE CENTRAL PLAINS AND CLOUD COVER BEGINS TO RACE
OUT AHEAD OF THE DOUBLE BARRELED LOW PRESSURE SYSTEM. OF MAIN
CONCERN TO NRN IL/NWRN INDIANA WILL BE THE TRACK AND DEVELOPMENT
OF THE SOUTHERN OF THE 2 LOWS...WHICH IS EXPECTED TO INITIALLY
DEVELOP OVER THE SOUTH HIGH PLAINS AND AND RAPIDLY DEEPEN AS IT
TRACKS THROUGH THE MIDDLE MISSISSIPPI VALLEY TO EASTERN WISCONSIN
BY EARLY TOMORROW EVENING.
THIS SYSTEM WILL BRING A COMPLEX WEATHER SCENARIO TO THE TERMINALS
WHICH WILL BE HIGHLY DEPENDANT ON THE EXACT TRACK OF THE
SYSTEM...AS WELL AS THE IMPACT OF THE DENSE SNOW PACK OVER THE
REGION. BASED ON THE CURRENTLY EXPECTED TRACK...AN ASSOCIATED WARM
FRONT WOULD LIFT NWD THROUGH THE REGION. WITH WARMER AIR ALOFT
OVERRIDING THE COLDER AIR AND SNOW PACK AT THE SFC...PCPN SHOULD
START OUT AS EITHER ALL SNOW...OR A WINTRY MIX OF
FZRA/IP/SN/RA...WHICH WILL BE HIGHLY DEPENDANT ON THE DEPTH AND
DURATION OF A SUB-FREEZING LAYER AT THE SFC...WITH THE DENSE
SNOWPACK POSSIBLY HELPING TO KEEP SFC TEMPS AT ARND THE FREEZING
MARK. THERE ARE PLEANTY OF QUESTIONS MARKS WITH THIS
SYSTEM...AMONG THEM BEING THE DURATION OF THE FREEZING AND FROZEN
PCPN TYPES. THE SYSTEM IS EXPECTED TO BE VERY FAST-MOVING...BUT
VERY DYNAMIC. THE SPEED OF THE SYSTEM WILL HELP LIMIT THE DURATION
OF THE FREEZING/FROZEN PCPN AND SNOW OR ICE ACCUMULATIONS WOULD BE
MINOR...BUT THE DYNAMICS OF THE SYSTEM COULD HELP GENERATE SOME
ADDITIONAL DYNAMIC COOLING...WHICH WOULD DELAY A CHAGEOVER FROM
SNOW TO FREEZING PCPN AND ADD TO THE SNOW ACCUMULATION TOTALS.
BEST ESTIMATION AT THIS POINT WOULD BE THAT ICE AND SNOW
ACCUMULATIONS WILL BE RELATIVELY MINOR...BUT ENOUGH TO HAVE A
SIGNIFICANT IMPACT ON OPERATIONS EVEN IF THE DURATION IS LIMITED
TO 2-3 HOURS. HAVE RELATIVELY HIGH CONFIDENCE THAT PCPN WILL
CHANGE OVER TO ALL RAIN AS THE WARM FRONT LIFTS NORTH OF THE
TERMINALS. HOWEVER...THIS WILL BRING THE NEXT SIGNIFICANT CONCERN
OF HEAVY RAIN WITH EMBEDDED THUNDERSTORMS. BASED ON THE CURRENTLY
ANTICIPATED TRACK OF THE SYSTEM...WITH THE MAIN SFC LOW PASSING
THROUGH FAR NWRN IL WOULD PUT THE TERMINAL AREAS INTO A WARM
SECTOR OF THE SYSTEM...FOLLOWED BY THE PASSAGE OF A STRONG COLD
FRONT. THE STRONGEST FORCING AND INSTABILITY SHOULD FOCUS THE MOST
EXTENSIVE AND STRONGEST THUNDERSTORMS TO THE SOUTHEAST OF THE
TERMINALS...BUT FORCING AND INSTABILITY SHOULD BE SUFFICIENT FOR
ISOLATED/EMBEDDED THUNDER FROM LATE MORNING AND THROUGH THE
AFTERNOON HOURS. IN ADDITION TO THE RAIN AND THUNDER
CONCERNS...ALSO HAVE CONCERN FOR THE POTENTIAL FOR DENSE FOG WITH
THE ADVECTION OF WARM/MOIST AIR OVER THE SNOW PACK...WHICH WILL
ALSO HAVE INCREASING MOISTURE CONTENT AS THE SNOW ABSORBS THE
FALLING RAIN. WITH HIGH DEWPOINT WARM AIR OVERSPREADING THE
SNOW...THERE IS A CONCERN THAT DENSE FOG COULD DEVELOP BY LATE
MORNING/EARLY AFTERNOON...EVEN WITH STRENGTHENING SELY-SLY WINDS.
HAVE LIMITED THE LOWER EXTENT OF THE VISBY TO 3/4SM TO 1SM FOR
TOMORROW...BUT THERE IS THE POTENTIAL FOR PERIODS OF VISBY
DROPPING TO 1/4SM IN FOG UNTIL THE PASSAGE OF THE STRONG COLD
FRONT TOMORROW EVENING.
THE THIRD CONCERN WILL THEN BECOME WINDS. SELY WINDS WILL BEGIN
TO INCREASE THROUGH THE MORNING WITH THE APPROACH OF THE COLD
FRONT...WITH SELY-SLY WINDS INCREASING AND BECMG GUSTY APPROACHING
30KT LATE THIS AFTERNOON. WHILE IT WILL BE AFTER THE CURRENT TAF
PERIOD...WINDS WILL SHIFT THROUGH SWLY TO WLY FOLLOWING THE FROPA
AND INCREASE FURTHER...POSSIBLY GUSTING TO 40KT EARLY TOMORROW
EVENING.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS THROUGH LATE TONIGHT.
* HIGH CONFIDENCE IN A PERIOD OF A WINTRY MIX OF PCPN DURG THE
EARLY MORNING HOURS...BUT LOWER CONFIDENCE IN TIMING AND
DURATION OF THE WINTRY MIX PCPN.
* HIGH CONFIDENCE THAT PCPN WILL CHANGE OVER TO ALL RAIN BY LATE
MORNING...BUT LOWER CONFIDENCE IN EXACT TIMING.
* MEDIUM CONFIDENCE IN WIND TRENDS.
* LOW TO MEDIUM CONFIDENCE IN VISBY TRENDS...ESPECIALLY RELATED TO
THE CHANCE FOR IFR/LIFR VIS IN FOG DEVELOPING LATE TOMORROW
MORNING INTO TOMORROW AFTERNOON.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...RAIN OR SNOW SHOWERS...WITH POSSIBLE MVFR
CONDITIONS. VERY STRONG SOUTHWEST WINDS OF 25 TO 35 MPH WITH GUSTS
UP TO 50 MPH
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF LIGHT SNOW.
TUESDAY...SLIGHT CHANCE OF LIGHT SNOW.
RODRIGUEZ
&&
.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.
IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...3 AM THURSDAY
TO 6 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...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 4 PM FRIDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
315 PM CST WED FEB 19 2014
.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
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NO CONCERNS IN THE NEAR TERM.
* WINTRY MIX OF PCPN BEGINNING DURG THE PRE-DAWN HOURS...LIKELY
SN/FZRA...THOUGH THERE IS A CHANCE THAT SOME IP COULD MIX IN
BRIEFLY. AMOUNT OF ICE ACCUMULATION IS UNCERTAIN.
* TIMING OF CHANGEOVER FROM WINTRY MIX TO ALL RAIN. LIKELY BY ARND
12Z...BUT EXACT TIMING IS STILL UNCERTAIN.
* VIS MAY DROP TO IFR...OR POSSIBLY LIFR...IN BR/FG BY LATE
MORNING OR EARLY AFTERNOON.
* CHANCE OF ISOLD/EMBEDDED TSRA LATE MORNING THROUGH EARLY
AFTERNOON UNTIL FRONTAL PASSAGE.
* WINDS SHIFTING TO SSWLY-SWLY BY EARLY AFTERNOON...STRENGTHENING
AND BECMG GUSTY TO ARND 30KT IN THE LATE AFTERNOON. GUSTS COULD
POSSIBLY BE EVEN HIGHER LATE AFTERNOON/EARLY EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...UPDATED 1845Z...
QUIET CONDITIONS THROUGH LATE TONIGHT. CLEAR SKIES WILL GIVE WAY
TO INCREASING MID AND HIGH CLOUD AS A COMPLEX WEATHER SYSTEM
DEVELOPS OVER THE CENTRAL PLAINS AND CLOUD COVER BEGINS TO RACE
OUT AHEAD OF THE DOUBLE BARRELED LOW PRESSURE SYSTEM. OF MAIN
CONCERN TO NRN IL/NWRN INDIANA WILL BE THE TRACK AND DEVELOPMENT
OF THE SOUTHERN OF THE 2 LOWS...WHICH IS EXPECTED TO INITIALLY
DEVELOP OVER THE SOUTH HIGH PLAINS AND AND RAPIDLY DEEPEN AS IT
TRACKS THROUGH THE MIDDLE MISSISSIPPI VALLEY TO EASTERN WISCONSIN
BY EARLY TOMORROW EVENING.
THIS SYSTEM WILL BRING A COMPLEX WEATHER SCENARIO TO THE TERMINALS
WHICH WILL BE HIGHLY DEPENDANT ON THE EXACT TRACK OF THE
SYSTEM...AS WELL AS THE IMPACT OF THE DENSE SNOW PACK OVER THE
REGION. BASED ON THE CURRENTLY EXPECTED TRACK...AN ASSOCIATED WARM
FRONT WOULD LIFT NWD THROUGH THE REGION. WITH WARMER AIR ALOFT
OVERRIDING THE COLDER AIR AND SNOW PACK AT THE SFC...PCPN SHOULD
START OUT AS EITHER ALL SNOW...OR A WINTRY MIX OF
FZRA/IP/SN/RA...WHICH WILL BE HIGHLY DEPENDANT ON THE DEPTH AND
DURATION OF A SUB-FREEZING LAYER AT THE SFC...WITH THE DENSE
SNOWPACK POSSIBLY HELPING TO KEEP SFC TEMPS AT ARND THE FREEZING
MARK. THERE ARE PLEANTY OF QUESTIONS MARKS WITH THIS
SYSTEM...AMONG THEM BEING THE DURATION OF THE FREEZING AND FROZEN
PCPN TYPES. THE SYSTEM IS EXPECTED TO BE VERY FAST-MOVING...BUT
VERY DYNAMIC. THE SPEED OF THE SYSTEM WILL HELP LIMIT THE DURATION
OF THE FREEZING/FROZEN PCPN AND SNOW OR ICE ACCUMULATIONS WOULD BE
MINOR...BUT THE DYNAMICS OF THE SYSTEM COULD HELP GENERATE SOME
ADDITIONAL DYNAMIC COOLING...WHICH WOULD DELAY A CHAGEOVER FROM
SNOW TO FREEZING PCPN AND ADD TO THE SNOW ACCUMULATION TOTALS.
BEST ESTIMATION AT THIS POINT WOULD BE THAT ICE AND SNOW
ACCUMULATIONS WILL BE RELATIVELY MINOR...BUT ENOUGH TO HAVE A
SIGNIFICANT IMPACT ON OPERATIONS EVEN IF THE DURATION IS LIMITED
TO 2-3 HOURS. HAVE RELATIVELY HIGH CONFIDENCE THAT PCPN WILL
CHANGE OVER TO ALL RAIN AS THE WARM FRONT LIFTS NORTH OF THE
TERMINALS. HOWEVER...THIS WILL BRING THE NEXT SIGNIFICANT CONCERN
OF HEAVY RAIN WITH EMBEDDED THUNDERSTORMS. BASED ON THE CURRENTLY
ANTICIPATED TRACK OF THE SYSTEM...WITH THE MAIN SFC LOW PASSING
THROUGH FAR NWRN IL WOULD PUT THE TERMINAL AREAS INTO A WARM
SECTOR OF THE SYSTEM...FOLLOWED BY THE PASSAGE OF A STRONG COLD
FRONT. THE STRONGEST FORCING AND INSTABILITY SHOULD FOCUS THE MOST
EXTENSIVE AND STRONGEST THUNDERSTORMS TO THE SOUTHEAST OF THE
TERMINALS...BUT FORCING AND INSTABILITY SHOULD BE SUFFICIENT FOR
ISOLATED/EMBEDDED THUNDER FROM LATE MORNING AND THROUGH THE
AFTERNOON HOURS. IN ADDITION TO THE RAIN AND THUNDER
CONCERNS...ALSO HAVE CONCERN FOR THE POTENTIAL FOR DENSE FOG WITH
THE ADVECTION OF WARM/MOIST AIR OVER THE SNOW PACK...WHICH WILL
ALSO HAVE INCREASING MOISTURE CONTENT AS THE SNOW ABSORBS THE
FALLING RAIN. WITH HIGH DEWPOINT WARM AIR OVERSPREADING THE
SNOW...THERE IS A CONCERN THAT DENSE FOG COULD DEVELOP BY LATE
MORNING/EARLY AFTERNOON...EVEN WITH STRENGTHENING SELY-SLY WINDS.
HAVE LIMITED THE LOWER EXTENT OF THE VISBY TO 3/4SM TO 1SM FOR
TOMORROW...BUT THERE IS THE POTENTIAL FOR PERIODS OF VISBY
DROPPING TO 1/4SM IN FOG UNTIL THE PASSAGE OF THE STRONG COLD
FRONT TOMORROW EVENING.
THE THIRD CONCERN WILL THEN BECOME WINDS. SELY WINDS WILL BEGIN
TO INCREASE THROUGH THE MORNING WITH THE APPROACH OF THE COLD
FRONT...WITH SELY-SLY WINDS INCREASING AND BECMG GUSTY APPROACHING
30KT LATE THIS AFTERNOON. WHILE IT WILL BE AFTER THE CURRENT TAF
PERIOD...WINDS WILL SHIFT THROUGH SWLY TO WLY FOLLOWING THE FROPA
AND INCREASE FURTHER...POSSIBLY GUSTING TO 40KT EARLY TOMORROW
EVENING.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS THROUGH LATE TONIGHT.
* HIGH CONFIDENCE IN A PERIOD OF A WINTRY MIX OF PCPN DURG THE
EARLY MORNING HOURS...BUT LOWER CONFIDENCE IN TIMING AND
DURATION OF THE WINTRY MIX PCPN.
* HIGH CONFIDENCE THAT PCPN WILL CHANGE OVER TO ALL RAIN BY LATE
MORNING...BUT LOWER CONFIDENCE IN EXACT TIMING.
* MEDIUM CONFIDENCE IN WIND TRENDS.
* LOW TO MEDIUM CONFIDENCE IN VISBY TRENDS...ESPECIALLY RELATED TO
THE CHANCE FOR IFR/LIFR VIS IN FOG DEVELOPING LATE TOMORROW
MORNING INTO TOMORROW AFTERNOON.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...RAIN OR SNOW SHOWERS...WITH POSSIBLE MVFR
CONDITIONS. VERY STRONG SOUTHWEST WINDS OF 25 TO 35 MPH WITH GUSTS
UP TO 50 MPH
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF LIGHT SNOW.
TUESDAY...SLIGHT CHANCE OF LIGHT SNOW.
RODRIGUEZ
&&
.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.
IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...3 AM THURSDAY
TO 6 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...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 4 PM FRIDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
305 PM CST WED FEB 19 2014
.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
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* NO CONCERNS IN THE NEAR TERM.
* WINTRY MIX OF PCPN BEGINNING DURG THE PRE-DAWN HOURS...LIKELY
SN/FZRA...THOUGH THERE IS A CHANCE THAT SOME IP COULD MIX IN
BRIEFLY. AMOUNT OF ICE ACCUMULATION IS UNCERTAIN.
* TIMING OF CHANGEOVER FROM WINTRY MIX TO ALL RAIN. LIKELY BY ARND
12Z...BUT EXACT TIMING IS STILL UNCERTAIN.
* VIS MAY DROP TO IFR...OR POSSIBLY LIFR...IN BR/FG BY LATE
MORNING OR EARLY AFTERNOON.
* CHANCE OF ISOLD/EMBEDDED TSRA LATE MORNING THROUGH EARLY
AFTERNOON UNTIL FRONTAL PASSAGE.
* WINDS SHIFTING TO SSWLY-SWLY BY EARLY AFTERNOON...STRENGTHENING
AND BECMG GUSTY TO ARND 30KT IN THE LATE AFTERNOON. GUSTS COULD
POSSIBLY BE EVEN HIGHER LATE AFTERNOON/EARLY EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...UPDATED 1845Z...
QUIET CONDITIONS THROUGH LATE TONIGHT. CLEAR SKIES WILL GIVE WAY
TO INCREASING MID AND HIGH CLOUD AS A COMPLEX WEATHER SYSTEM
DEVELOPS OVER THE CENTRAL PLAINS AND CLOUD COVER BEGINS TO RACE
OUT AHEAD OF THE DOUBLE BARRELED LOW PRESSURE SYSTEM. OF MAIN
CONCERN TO NRN IL/NWRN INDIANA WILL BE THE TRACK AND DEVELOPMENT
OF THE SOUTHERN OF THE 2 LOWS...WHICH IS EXPECTED TO INITIALLY
DEVELOP OVER THE SOUTH HIGH PLAINS AND AND RAPIDLY DEEPEN AS IT
TRACKS THROUGH THE MIDDLE MISSISSIPPI VALLEY TO EASTERN WISCONSIN
BY EARLY TOMORROW EVENING.
THIS SYSTEM WILL BRING A COMPLEX WEATHER SCENARIO TO THE TERMINALS
WHICH WILL BE HIGHLY DEPENDANT ON THE EXACT TRACK OF THE
SYSTEM...AS WELL AS THE IMPACT OF THE DENSE SNOW PACK OVER THE
REGION. BASED ON THE CURRENTLY EXPECTED TRACK...AN ASSOCIATED WARM
FRONT WOULD LIFT NWD THROUGH THE REGION. WITH WARMER AIR ALOFT
OVERRIDING THE COLDER AIR AND SNOW PACK AT THE SFC...PCPN SHOULD
START OUT AS EITHER ALL SNOW...OR A WINTRY MIX OF
FZRA/IP/SN/RA...WHICH WILL BE HIGHLY DEPENDANT ON THE DEPTH AND
DURATION OF A SUB-FREEZING LAYER AT THE SFC...WITH THE DENSE
SNOWPACK POSSIBLY HELPING TO KEEP SFC TEMPS AT ARND THE FREEZING
MARK. THERE ARE PLEANTY OF QUESTIONS MARKS WITH THIS
SYSTEM...AMONG THEM BEING THE DURATION OF THE FREEZING AND FROZEN
PCPN TYPES. THE SYSTEM IS EXPECTED TO BE VERY FAST-MOVING...BUT
VERY DYNAMIC. THE SPEED OF THE SYSTEM WILL HELP LIMIT THE DURATION
OF THE FREEZING/FROZEN PCPN AND SNOW OR ICE ACCUMULATIONS WOULD BE
MINOR...BUT THE DYNAMICS OF THE SYSTEM COULD HELP GENERATE SOME
ADDITIONAL DYNAMIC COOLING...WHICH WOULD DELAY A CHAGEOVER FROM
SNOW TO FREEZING PCPN AND ADD TO THE SNOW ACCUMULATION TOTALS.
BEST ESTIMATION AT THIS POINT WOULD BE THAT ICE AND SNOW
ACCUMULATIONS WILL BE RELATIVELY MINOR...BUT ENOUGH TO HAVE A
SIGNIFICANT IMPACT ON OPERATIONS EVEN IF THE DURATION IS LIMITED
TO 2-3 HOURS. HAVE RELATIVELY HIGH CONFIDENCE THAT PCPN WILL
CHANGE OVER TO ALL RAIN AS THE WARM FRONT LIFTS NORTH OF THE
TERMINALS. HOWEVER...THIS WILL BRING THE NEXT SIGNIFICANT CONCERN
OF HEAVY RAIN WITH EMBEDDED THUNDERSTORMS. BASED ON THE CURRENTLY
ANTICIPATED TRACK OF THE SYSTEM...WITH THE MAIN SFC LOW PASSING
THROUGH FAR NWRN IL WOULD PUT THE TERMINAL AREAS INTO A WARM
SECTOR OF THE SYSTEM...FOLLOWED BY THE PASSAGE OF A STRONG COLD
FRONT. THE STRONGEST FORCING AND INSTABILITY SHOULD FOCUS THE MOST
EXTENSIVE AND STRONGEST THUNDERSTORMS TO THE SOUTHEAST OF THE
TERMINALS...BUT FORCING AND INSTABILITY SHOULD BE SUFFICIENT FOR
ISOLATED/EMBEDDED THUNDER FROM LATE MORNING AND THROUGH THE
AFTERNOON HOURS. IN ADDITION TO THE RAIN AND THUNDER
CONCERNS...ALSO HAVE CONCERN FOR THE POTENTIAL FOR DENSE FOG WITH
THE ADVECTION OF WARM/MOIST AIR OVER THE SNOW PACK...WHICH WILL
ALSO HAVE INCREASING MOISTURE CONTENT AS THE SNOW ABSORBS THE
FALLING RAIN. WITH HIGH DEWPOINT WARM AIR OVERSPREADING THE
SNOW...THERE IS A CONCERN THAT DENSE FOG COULD DEVELOP BY LATE
MORNING/EARLY AFTERNOON...EVEN WITH STRENGTHENING SELY-SLY WINDS.
HAVE LIMITED THE LOWER EXTENT OF THE VISBY TO 3/4SM TO 1SM FOR
TOMORROW...BUT THERE IS THE POTENTIAL FOR PERIODS OF VISBY
DROPPING TO 1/4SM IN FOG UNTIL THE PASSAGE OF THE STRONG COLD
FRONT TOMORROW EVENING.
THE THIRD CONCERN WILL THEN BECOME WINDS. SELY WINDS WILL BEGIN
TO INCREASE THROUGH THE MORNING WITH THE APPROACH OF THE COLD
FRONT...WITH SELY-SLY WINDS INCREASING AND BECMG GUSTY APPROACHING
30KT LATE THIS AFTERNOON. WHILE IT WILL BE AFTER THE CURRENT TAF
PERIOD...WINDS WILL SHIFT THROUGH SWLY TO WLY FOLLOWING THE FROPA
AND INCREASE FURTHER...POSSIBLY GUSTING TO 40KT EARLY TOMORROW
EVENING.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS THROUGH LATE TONIGHT.
* HIGH CONFIDENCE IN A PERIOD OF A WINTRY MIX OF PCPN DURG THE
EARLY MORNING HOURS...BUT LOWER CONFIDENCE IN TIMING AND
DURATION OF THE WINTRY MIX PCPN.
* HIGH CONFIDENCE THAT PCPN WILL CHANGE OVER TO ALL RAIN BY LATE
MORNING...BUT LOWER CONFIDENCE IN EXACT TIMING.
* MEDIUM CONFIDENCE IN WIND TRENDS.
* LOW TO MEDIUM CONFIDENCE IN VISBY TRENDS...ESPECIALLY RELATED TO
THE CHANCE FOR IFR/LIFR VIS IN FOG DEVELOPING LATE TOMORROW
MORNING INTO TOMORROW AFTERNOON.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...RAIN OR SNOW SHOWERS...WITH POSSIBLE MVFR
CONDITIONS. VERY STRONG SOUTHWEST WINDS OF 25 TO 35 MPH WITH GUSTS
UP TO 50 MPH
FRIDAY...VFR.
SATURDAY...VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF LIGHT SNOW.
TUESDAY...SLIGHT CHANCE OF LIGHT SNOW.
RODRIGUEZ
&&
.MARINE...
417 AM CST
SURFACE TROUGH AND FRONTAL BOUNDARY CONTINUE TO SHIFT EAST OF THE
LAKE EARLY THIS MORNING...AS WINDS SETTLE BACK TO A WEST/NORTHWEST
WIND AROUND 10 TO 20 KT ACROSS THE ENTIRE LAKE. AS HIGH PRESSURE
OVER THE CENTRAL PLAINS MOVES EAST THROUGH THE MID MISSISSIPPI
VALLEY TODAY...WINDS WILL TURN BACK TO THE SOUTHWEST. THIS HIGH
WILL THEN PUSH EAST TO THE ATLANTIC COAST TONIGHT WHILE WINDS
BECOME MORE SOUTHERLY...AND BEGIN TO INCREASE. EXPECT SOUTHEAST
WINDS TO INCREASE DURING THE DAY THURSDAY AS DEVELOPING LOW
PRESSURE MOVES OUT OF THE CENTRAL PLAINS NORTHEAST TO THE UPPER
MIDWEST AND WESTERN GREAT LAKES. GALES WILL BECOME MORE LIKELY BY
LATE THURSDAY AFTERNOON OVER THE OPEN WATERS AND NEARSHORE...WITH
THESE SPEEDS CONTINUING INTO THE NIGHT AS THE LOW CONTINUES
NORTHEAST ACROSS THE GREAT LAKES REGION WHILE FURTHER
STRENGTHENING. ALTHOUGH HIGH END GALES WILL CONTINUE FOR THE
NEARSHORE...SPEEDS WILL LIKELY INCREASE TO STORM FORCE AFTER
MIDNIGHT FOR THE OPEN WATERS. STORM FORCE WINDS ARE ANTICIPATED
INTO FRIDAY AFTERNOON BEFORE WEAKENING BACK TO GALES...WITH THESE
GALES POSSIBLY CONTINUING FRIDAY NIGHT. GALE/STORM WATCHES HAVE
BEEN ISSUED FOR BOTH THE NEARSHORE AND OPEN WATERS DURING THESE
PERIODS. CONFIDENCE IS NOT TOO HIGH WITH REGARDS TO THE RESULTANT
WAVE HEIGHTS DUE TO ICE COVERAGE AND FETCH. ALTHOUGH WITH WARMER
AIR TEMPS EXPECTED TODAY INTO THURSDAY...ICE COVERAGE COULD
DECREASE SOME WITH THE POTENTIAL FOR HIGHER WAVES THAN WHAT IS
CURRENTLY FORECAST...ESPECIALLY WITH STORM FORCE WINDS TO 55 KT
POSSIBLE.
RODRIGUEZ
&&
.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.
IN...FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019...3 AM THURSDAY
TO 6 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...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 4 PM FRIDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
231 PM MST WED FEB 19 2014
.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 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1032 AM MST WED FEB 19 2014
GUSTY WINDS WILL CONTINUE THROUGH MOST OF THE PERIOD WITH
STRONGEST WINDS TONIGHT WITH FRONTAL PASSAGE WHEN GUSTS 45KT ARE
EXPECTED IMMEDIATELY BEHIND FRONT (POSSIBLY 50KT). THERE WILL BE
TWO LULLS IN THE WINDS AS SURFACE GRADIENT SHIFTS AND GUSTS
BRIEFLY DIMINISH...WITH THE FIRST LATE THIS AFTERNOON/EVENING AND
THEN ANOTHER AROUND SUNRISE THURSDAY.
FLIGHT CONDITIONS WILL DETERIORATE RAPIDLY AFTER 06Z TONIGHT WITH
LIFR/VILFR CONDITIONS POSSIBLE FOR A BRIEF PERIOD AROUND 08-09Z AS
A MODERATE BAND OF SNOW AND BLOWING SNOW MOVES OVER BOTH
TERMINALS. I SHOWED A TRANSITION TO IFR PREVAILING IN THE CURRENT
TAFS...AND IT IS STILL TOO FAR OUT TO ADD TEMPO...HOWEVER THIS
WILL LIKELY NEED TO BE ADDED DURING SUBSEQUENT SCHEDULED UPDATES
TO TIME OUT THE PERIOD OF LOW CONDITIONS. THIS BAND WILL MOVE
THROUGH THE REGION QUICK ENOUGH WITH STABLE AIR BEHIND IT
SUPPORTING RAPIDLY CLEARING CONDITIONS TOWARDS 12Z AT BOTH
TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY FROM 8 PM MST /9 PM CST/ THIS EVENING TO
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 FROM 1 AM TO 8 AM CST THURSDAY FOR
KSZ003-004-015-016-028-029-042.
CO...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 6 AM MST
THURSDAY FOR COZ090>092.
WIND ADVISORY FROM 9 AM TO 5 PM MST THURSDAY FOR COZ090>092.
NE...WINTER WEATHER ADVISORY FROM 8 PM MST /9 PM CST/ THIS EVENING TO
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.
&&
$$
SHORT TERM...DR
LONG TERM...99
AVIATION...DR
AREA FORECAST DISCUSSION
NWS WICHITA KS
209 PM CST WED FEB 19 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 205 PM CST WED FEB 19 2014
THE MAIN FORECAST CONCERNS WILL BE THE POTENTIAL FOR STRONG-SEVERE
STORMS IN SOUTHEAST KS TONIGHT...VERY STRONG NORTHWEST WINDS
THURSDAY...AND SNOW/REDUCED VISIBILITIES IN CENTRAL KS EARLY
THURSDAY. A STRONG SHORTWAVE TROUGH/PV ANOMALY OVER THE GREAT
BASIN THIS AFTERNOON...WILL TRANSLATE EASTWARD ACROSS THE CENTRAL
PLAINS LATER TONIGHT THROUGH THURSDAY. A 45-50 KNOT SOUTHERLY LOW-
LEVEL JET WILL INDUCE MOISTURE TRANSPORT NORTHWARD THROUGH EASTERN
KANSAS THROUGH TONIGHT. SCATTERED ELEVATED SHOWERS/THUNDERSTORMS
WILL CONTINUE TO DEVELOP OVER SOUTHEASTERN KS THIS AFTERNOON INTO
THIS EVENING WHILE GRADUALLY INTENSIFYING AS BETTER ELEVATED
INSTABILITY ARRIVES. THE ELEVATED INSTABILITY/STRONG SHEAR WILL
LIKELY RESULT IN A FEW STRONG-SEVERE STORMS THIS EVENING WITH
HAIL...BEFORE THE BRUNT OF THIS ACTIVITY SHIFTS NORTHEAST OUT OF
SOUTHEAST KS. THERE COULD BE RENEWED THUNDERSTORM DEVELOPMENT IN
SOUTHEAST KS VERY LATE TONIGHT/EARLY THURSDAY MORNING...AS THE
STRONG PV ANOMALY MOVES IN WITH VERY STEEP MID-LEVEL LAPSE RATES.
AGAIN LARGE HAIL WILL BE THE PRIMARY HAZARD.
THE PRESSURE GRADIENT WILL TIGHTEN DRAMATICALLY BEHIND THE EASTWARD
MOVING COLD FRONT VERY LATE TONIGHT INTO THURSDAY. STEEP LOW-LEVEL
LAPSE RATES WILL PROMOTE THE MIXDOWN OF VERY STRONG 850 MB WINDS
BEHIND THE COLD FRONT. WE PLAN TO UPGRADE THE CURRENT HIGH WIND
WATCH TO A WARNING FOR ALONG/W OF HIGHWAY 14 WHERE DAMAGING WINDS
APPEAR MOST LIKELY...WHILE MAINTAINING THE CURRENT WIND ADVISORY
ALONG/E OF I-135 THURSDAY. COLD AIR ADVECTION WILL CHANGE THE
PRECIPITATION FROM RAIN TO A BRIEF PERIOD (2-4 HOURS) OF SNOW IN
CENTRAL KS VERY LATE TONIGHT INTO MID MORNING THURSDAY. THE
COMBINATION OF SNOW (UP TO 1 INCH ACCUMULATION) AND VERY STRONG
WINDS WILL LIKELY RESULT IN BLOWING SNOW AND SHARPLY REDUCED
VISIBILITIES SO WILL CARRY A WINTER WEATHER ADVISORY FOR PART OF
CENTRAL KS. STRONG SUBSIDENCE WILL SET IN ON THE BACKSIDE OF THE
UPPER TROUGH THURSDAY AFTERNOON ENDING PRECIPITATION IN OUR AREA.
MOSTLY CLEAR SKIES EXPECTED THURSDAY NIGHT INTO FRIDAY. WESTERLY
WINDS WILL INDUCE DOWNSLOPE WARMING FRIDAY AND THIS WILL LEAD TO
ABOVE NORMAL HIGHS IN THE UPPER 50S/LOW 60S. AN INITIAL SHALLOW
SURGE OF COLDER AIR WILL ARRIVE FRIDAY NIGHT INTO SATURDAY RESULTING
IN TEMPERATURES CLOSER TO SEASONAL AVERAGES.
JMC
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 205 PM CST WED FEB 19 2014
UPPER LEVEL RIDGING WILL DEVELOP NORTHWARD FROM THE WEST COAST UP
THROUGH WESTERN CANADA/EASTERN ALASKA. MEANWHILE A LARGE UPPER
TROUGH WILL CONTINUE TO DEVELOP OVER CENTRAL/EASTERN CANADA DOWN
THROUGH THE EASTERN CONUS. THIS PATTERN WILL BE CONDUCIVE TO COLD
AIR SURGES FROM WESTERN CANADA INTO THE CENTRAL PLAINS. ONE SURGE IS
PROGGED MONDAY NIGHT INTO TUESDAY...WITH A SECOND SURGE TUESDAY
NIGHT INTO WEDNESDAY. WE EXPECT SLIGHTLY BELOW NORMAL TEMPERATURES
DURING THE PERIOD WITH MAINLY DRY WEATHER PREVAILING.
JMC
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1118 AM CST WED FEB 19 2014
THERE ARE TWO TO THREE PRIMARY CONCERNS RELATED TO ONE UPPER LEVEL
SYSTEM. AHEAD OF THE SURFACE FRONT/WAVE MOISTURE IS EXPECTED TO
STREAM NORTHWARD DURING THE AFTERNOON HOURS TODAY. THE MOISTURE
TRANSPORT WILL BE STRONGEST LATE THIS AFTERNOON AND EVENING.
LIKING HOW THE HRRR EVOLVES CONVECTION THIS AFTERNOON/EVENING.
THINK THE BEST CHANCES FOR CONVECTION WILL BE ALONG THE NOSE OF
THE MOISTURE TRANSPORT AND THAT IT WILL QUICKLY SHIFT FROM
SOUTHEAST KANSAS NORTHEASTWARD. HAVE KEPT THE VCTS IN AT KCNU FOR
THE EVENING WITH A STRUGGLE OF ACTUAL TIMING OF THE PREVAILING
STORMS. ONLY PUT CONVECTION IN AT KCNU...BUT THERE COULD BE SOME
ACTIVITY AS FAR WEST AS KICT...ALTHOUGH CONFIDENCE IS LOW FOR THIS
TO OCCUR.
THE SECOND CONCERN IS A VERY STRONG PRESSURE GRADIENT WILL IMPACT
THE REGION BEHIND THE COLD FRONT. THIS GRADIENT WILL CAUSE WINDS
TO BECOME NORTHWESTERLY AND SUSTAINED AROUND 30-35KTS AND GUSTS TO
40+ KTS.
THE THIRD CONCERN IS WINTRY PRECIPITATION IMPACTING GENERALLY KRSL
AND KSLN IN THE MORNING HOURS. THIS WILL BE IN COMBINATION WITH
THE VERY STRONG WINDS AND WILL CAUSE A QUICK ACCUMULATION OF SOME
SNOW WITH BLOWING SNOW REDUCING VISIBILITIES.
BILLINGS WRIGHT
&&
.FIRE WEATHER...
ISSUED AT 205 PM CST WED FEB 19 2014
THE COMBINATION OF DRIER AIR OVERSPREADING THE REGION AND STRONG
NORTHWEST WINDS WILL RESULT IN VERY HIGH GRASSLAND FIRE DANGER
CONDITIONS REGION-WIDE THURSDAY. MINIMUM AFTERNOON RELATIVE
HUMIDITIES OF 25-35% ARE EXPECTED.
JMC
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 39 48 27 60 / 30 30 0 0
HUTCHINSON 35 48 27 59 / 60 60 0 0
NEWTON 37 47 28 59 / 50 40 0 0
ELDORADO 42 48 27 59 / 50 30 0 0
WINFIELD-KWLD 43 51 27 61 / 30 30 0 0
RUSSELL 33 46 26 58 / 70 70 0 10
GREAT BEND 34 47 26 58 / 60 60 0 0
SALINA 34 45 27 57 / 80 80 0 10
MCPHERSON 35 47 27 58 / 70 70 0 0
COFFEYVILLE 52 56 29 62 / 60 40 0 0
CHANUTE 49 53 26 58 / 60 50 0 10
IOLA 48 52 27 57 / 70 50 0 10
PARSONS-KPPF 51 55 27 60 / 60 40 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 6 AM TO 4 PM CST THURSDAY FOR KSZ049-051>053-
068>072-083-092>096-098>100.
HIGH WIND WARNING FROM 3 AM TO 10 AM CST THURSDAY FOR KSZ032-033-
047-048-050-067-082-091.
WINTER WEATHER ADVISORY FROM 3 AM TO 10 AM CST THURSDAY FOR
KSZ032-033-047>051.
WIND ADVISORY FROM 10 AM TO 4 PM CST THURSDAY FOR KSZ032-033-047-
048-050-067-082-091.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1128 AM CST WED FEB 19 2014
...UPDATED FOR AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 312 AM CST WED FEB 19 2014
ABOVE NORMAL TEMPERATURES EXPECTED AGAIN TODAY BUT NOT AS WARM AS
YESTERDAY WITH MORE CLOUDS SPREADING ACROSS THE REGION.
MEANWHILE...MOISTURE TRANSPORT WILL RAMP UP ACROSS EASTERN KANSAS
FOR THIS AFTERNOON INTO TONIGHT AHEAD OF FLEET-FOOTED UPPER WAVE
CURRENTLY OVER THE PACIFIC NORTHWEST. SCATTERED THUNDERSTORMS LOOK
TO DEVELOP THIS AFTERNOON...MAINLY FOR LOCATIONS EAST OF THE KANSAS
TURNPIKE. THE COMBINATION OF ELEVATED INSTABILITY AND STRONG SHEAR
ALOFT COULD GIVE WAY TO A FEW STRONG/SEVERE THUNDERSTORMS WITH HAIL
BEING THE PRIMARY HAZARD. OTHERWISE SURFACE LOW PRESSURE WILL
UNDERGO EXPLOSIVE CYCLOGENESIS TONIGHT WHICH WILL CAUSE A RAPID
TIGHTENING OF THE PRESSURE GRADIENT WINDS ON THE BACKSIDE FOR LATE
TONIGHT...THEN SPREAD EASTWARD ACROSS THE REGION ON THURSDAY. WE
WILL HOIST A HIGH WIND WATCH FOR LOCATIONS THAT COULD SEE WIND
SPEEDS REACHING EXTREME LEVELS(LATE TONIGHT-THURSDAY MORNING) AND
CARRY A WIND ADVISORY FOR THE REMAINDER OF THE AREA ON THURSDAY. THE
COLDER AIR WILL CHANGE THE PRECIP TYPE OVER TO SNOW ACROSS CENTRAL
KANSAS FOR LATE TONIGHT INTO THURSDAY MORNING. IT LOOKS TO BE A
BRIEF PERIOD OF SNOW FOR CENTRAL KANSAS WITH THE DEFORMATION ZONE
RACING EASTWARD...BUT IF THE SNOW COMES DOWN AT A HIGH ENOUGH RATE
COMBINED WITH THE EXTREME WINDS THIS COULD DROP VISIBILITIES
SIGNIFICANTLY AND LATER SHIFTS COULD END UP HOISTING A WINTER
WEATHER ADVISORY FOR THIS HAZARD. THE PRECIP WILL END QUICKLY AS
STRONG SUBSIDENCE SPREADS OVER THE AREA FOR THURSDAY AFTERNOON.
A NICE REBOUND WILL BE IN STORE FOR THE AREA ON FRIDAY AS PREMIUM
DOWNSLOPE EFFECTS BOOSTS DAYTIME HIGHS ABOVE NORMAL.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 312 AM CST WED FEB 19 2014
WE SHOULD SEE A LITTLE COOL DOWN FOR THE WEEKEND WITH A MORE
NOTICEABLE COOL DOWN ARRIVING ON MONDAY NIGHT INTO TUESDAY...AS NEXT
SURGE OF COLDER AIR PUSHES SOUTHWARD INTO KANSAS.
JAKUB
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1118 AM CST WED FEB 19 2014
THERE ARE TWO TO THREE PRIMARY CONCERNS RELATED TO ONE UPPER LEVEL
SYSTEM. AHEAD OF THE SURFACE FRONT/WAVE MOISTURE IS EXPECTED TO
STREAM NORTHWARD DURING THE AFTERNOON HOURS TODAY. THE MOISTURE
TRANSPORT WILL BE STRONGEST LATE THIS AFTERNOON AND EVENING.
LIKING HOW THE HRRR EVOLVES CONVECTION THIS AFTERNOON/EVENING.
THINK THE BEST CHANCES FOR CONVECTION WILL BE ALONG THE NOSE OF
THE MOISTURE TRANSPORT AND THAT IT WILL QUICKLY SHIFT FROM
SOUTHEAST KANSAS NORTHEASTWARD. HAVE KEPT THE VCTS IN AT KCNU FOR
THE EVENING WITH A STRUGGLE OF ACTUAL TIMING OF THE PREVAILING
STORMS. ONLY PUT CONVECTION IN AT KCNU...BUT THERE COULD BE SOME
ACTIVITY AS FAR WEST AS KICT...ALTHOUGH CONFIDENCE IS LOW FOR THIS
TO OCCUR.
THE SECOND CONCERN IS A VERY STRONG PRESSURE GRADIENT WILL IMPACT
THE REGION BEHIND THE COLD FRONT. THIS GRADIENT WILL CAUSE WINDS
TO BECOME NORTHWESTERLY AND SUSTAINED AROUND 30-35KTS AND GUSTS TO
40+ KTS.
THE THIRD CONCERN IS WINTRY PRECIPITATION IMPACTING GENERALLY KRSL
AND KSLN IN THE MORNING HOURS. THIS WILL BE IN COMBINATION WITH
THE VERY STRONG WINDS AND WILL CAUSE A QUICK ACCUMULATION OF SOME
SNOW WITH BLOWING SNOW REDUCING VISIBILITIES.
BILLINGS WRIGHT
&&
.FIRE WEATHER...
ISSUED AT 312 AM CST WED FEB 19 2014
THE COMBINATION OF DRIER AIR OVERSPREADING THE REGION AND STRONG
NORTHWEST WILL GIVE WAY TO VERY HIGH GRASSLAND FIRE DANGER
CONDITIONS ACROSS THE ENTIRE REGION THURSDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 59 38 48 28 / 20 30 30 0
HUTCHINSON 58 35 48 28 / 20 60 60 0
NEWTON 57 36 46 29 / 20 60 60 0
ELDORADO 59 39 47 28 / 30 60 60 10
WINFIELD-KWLD 61 41 51 28 / 20 30 30 0
RUSSELL 58 34 46 27 / 10 70 70 0
GREAT BEND 58 35 47 27 / 10 60 60 0
SALINA 57 35 45 28 / 20 80 80 0
MCPHERSON 57 35 47 28 / 20 70 70 0
COFFEYVILLE 64 51 55 30 / 50 60 60 10
CHANUTE 60 47 52 27 / 50 70 70 10
IOLA 59 46 51 28 / 50 80 80 10
PARSONS-KPPF 62 50 54 28 / 50 70 70 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 6 AM TO 4 PM CST THURSDAY FOR KSZ049-051>053-
068>072-083-092>096-098>100.
HIGH WIND WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
KSZ032-033-047-048-050-067-082-091.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
519 PM EST WED FEB 19 2014
.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 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1230 PM EST WED FEB 19 2014
EXPECT VFR CONDITIONS TO PREVAIL FOR THE MOST PART AT KIWD/KCMX/KSAW
THRU THE FCST PERIOD WITH JUST A MINOR CONCERN FOR MVFR VIS IN FOG
TONIGHT AT KCMX/KSAW. WITH THICKENING MID CLOUDS AHEAD OF
APPROACHING WINTER STORM...VIS SHOULDN`T DROP VERY LOW IF FOG DOES
IN FACT DEVELOP TONIGHT AS RADIATIONAL COOLING WILL BE MINIMIZED.
THE OUTLOOK FOR LATE THU INTO FRI IS FOR VERY POOR FLYING
CONDITIONS. DISRUPTIONS TO AIR TRAVEL ARE QUITE LIKELY DURING THIS
PERIOD AS A SIGNIFICANT WINTER SNOWSTORM AFFECTS THE REGION. AN
EXTENDED PERIOD OF CONDITIONS BLO AIRFIELD LANDING MINS IS POSSIBLE
AT KCMX BEGINNING AT SOME POINT THU NIGHT OR FRI MORNING.
&&
.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/ THURSDAY TO NOON
EST /11 AM CST/ FRIDAY FOR MIZ002-004-009-010-084.
WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ006-007-012>014-085.
BLIZZARD WARNING FROM 7 PM THURSDAY TO 10 PM EST FRIDAY FOR
MIZ001-003.
WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY
MORNING FOR MIZ005-011.
LAKE SUPERIOR...
GALE WARNING FROM 7 PM THURSDAY 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 THURSDAY TO 5 PM EST FRIDAY FOR LMZ221-
248-250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...MCD
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1234 PM EST WED FEB 19 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 326 AM EST WED FEB 19 2014
WE/LL SEE QUITE A BIT OF SUNSHINE TODAY BUT KEEP AN EYE TO THE
SOUTHWEST AS A STORM DEVELOPS IN THE PLAINS. THAT STORM WILL MOVE
TOWARD THE GREAT LAKES THURSDAY AND STRENGTHEN. INITIALLY...A MIX OF
RAIN, FREEZING RAIN, AND SNOW WILL DEVELOP THURSDAY MORNING BUT
CHANGE TO RAIN FROM SOUTH TO NORTH AS WARMER IS IS DRAWN NORTH.
THUNDERSTORMS ARE POSSIBLE TOO THURSDAY AFTERNOON. STRONG WINDS WILL
DEVELOP THURSDAY NIGHT AND CONTINUE INTO FRIDAY MORNING.
&&
.UPDATE...
ISSUED AT 610 AM EST WED FEB 19 2014
ISSUED A QUICK FORECAST UPDATE TO COVER THE NARROW BAND OF PRECIP
APPROACHING FROM THE WEST. THOUGHT THE DRY AIR WOULD ERODE THIS
PRECIP BEFORE IT GOT HERE BUT A FEW 30 DBZ ECHOES ARE MOVING
ACROSS THE LAKE AND SOME OF IT WILL OBVIOUSLY GET HERE.
PRECIP TYPE IS TRICKY. LATEST RAP FCST SOUNDINGS SUGGEST A MIX OF
LIGHT FREEZING RAIN AND SNOW INITIALLY ALTHOUGH WET BULB EFFECTS
THEN COOL THE SOUNDINGS BELOW FREEZING AS THE COLUMN MOISTENS
SUGGESTING ALL SNOW. THE PRECIP DOES NOT APPEAR HEAVY ENOUGH OR OF
LONG ENOUGH DURATION THAT THE COOLING WOULD BE THAT DRAMATIC SO A
BRIEF LIGHT MIX SEEMS THE MOST LIKELY SCENARIO AS THIS BAND MOVES
THROUGH.
SFC TEMPS SHOULD WARM ABOVE FREEZING AFTER 10 AM SO ANY LINGERING
PRECIP MOVING SOUTH AND EAST OF GRR AT THAT TIME SHOULD BE MIXED
RAIN AND SNOW.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 326 AM EST WED FEB 19 2014
FORECAST CONCERNS DEAL WITH THE APPROACHING STORM THURSDAY.
AFTER A MOSTLY SUNNY DAY SKIES WILL BEGIN TO CLOUD UP TONIGHT. LOW
PRESSURE DEVELOPING OVER THE SOUTHERN PLAINS WILL MOVE NORTHEAST
TUESDAY AND RAPIDLY DEEPEN AS IT MOVES WEST OF THE CWA ACROSS
EASTERN WISCONSIN. PCPN WILL MOVE INTO THE SW CWA AFTER 12Z
THURSDAY. INITIALLY, FORECAST SOUNDINGS SUGGEST THE PCPN WILL BE A
MIX OF RAIN, FREEZING RAIN AND SLEET. NORTH OF I-96, MUCH OF THE
PCPN WILL BE SNOW WITH FREEZING RAIN MIXING IN. I SUSPECT WE`LL NEED
A WINTER WEATHER ADVISORY THURSDAY FOR MUCH OF THE CWA.
H8 WINDS NEAR 70KTS WILL DRAW ABUNDANT WARM AIR NORTHWARD AND THE
PCPN WILL CHANGE TO RAIN FROM SOUTH TO NORTH. QPF IN THE HALF INCH
TO INCH RANGE WILL MOSTLY GET TRAPPED IN THE SNOW PACK AND THAT`S
NOT GOOD NEWS BECAUSE THE ADDED WEIGHT TO THE SNOWPACK WILL LIKELY
RESULT IN MORE ROOF COLLAPSES. PONDING ON ROADS DUE TO CLOGGED STORM
DRAINS WILL ALSO BE AN ISSUES. MODELS SNOW SFC DEWPOINTS RISING
ABOVE FREEZING LATE IN THE DAY AND THAT`S WHEN VISIBILITIES WILL
DECREASE THE MOST.
ALONG WITH THE WARMER AIR WILL COME INCREASED INSTABILITY. ELEVATED
LI`S ARE BELOW 0C AND MUCAPE RISES TO 500 J/KG. GIVEN SHEAR VALUES
OVER 60KTS...WE`LL LIKELY SEE THUNDERSTORMS DEVELOP. THE BEST CHANCE
FOR STRONG TO SEVERE STORMS WILL BE JUST SOUTH OF THE CWA.
AN OCCLUDED FRONT WILL SWEEP IN FROM THE WEST THURSDAY EVENING.
STRONG WEST WINDS WILL DEVELOP AND GUST TO 40-45 MPH AND COLDER AIR
WILL MOVE BACK INTO THE CWA. SNOW SHOWERS AND COLDER TEMPERATURES
ARE EXPECTED FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 AM EST WED FEB 19 2014
THE LONG TERM PERIOD WILL FEATURE GENERALLY QUIET WEATHER WITH BELOW
NORMAL TEMPERATURES AS A BROAD UPPER TROUGH REMAINS FIRMLY ANCHORED
OVER MOST OF CANADA AND THE NORTHERN AND EASTERN UNITED STATES. THE
PERSISTENT COLD CYCLONIC FLOW WILL PROMOTE OCCASIONAL LIGHT LAKE
EFFECT SNOW SHOWER ACTIVITY BUT NO SIGNIFICANT ACCUMULATIONS ARE
EXPECTED. CLIPPER TYPE SHORTWAVES DIVING THROUGH THE NORTHWEST FLOW
ALOFT COULD BRING BRIEF PERIODS SNOW SHOWER ENHANCEMENT BUT AGAIN NO
MAJOR SYSTEMS ARE FORESEEN AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1226 PM EST WED FEB 19 2014
THE MAIN CHALLENGE IN THE AVIATION FORECAST DEALS WITH POTENTIAL STRATUS/FOG
OVERNIGHT FOLLOWED BY WINTRY MIX AND IMPACT CEILINGS/VSBYS THU.
WITH THE RELATIVELY WARM TEMPERATURES TODAY RESULTING IN SOME
MELTING...THIS ADDED MOISTURE COULD LEAD TO FOG/STRATUS FORMING
THIS EVENING. NOT CERTAIN TO HAPPEN AND TIMING IS A
CHALLENGE...BUT I AM THINKING THAT AFTER A FEW HOURS OF
RADIATIONAL COOLING WE WILL SEE THESE IMPACT CONDITIONS DEVELOPING
FROM SOUTH TO NORTH THROUGH THE AREA. AS THE APPROACHING STORM
NEARS LATER TONIGHT AND THU AM...THIS WILL ACT TO BREAK UP THE
FOG/STRATUS DECK...POSSIBLY BEFORE 12Z.
THEN PRECIPITATION MOVES IN FROM THE SOUTHWEST...LIKELY AFTER 12Z.
LOW LEVELS LOOK DRY...SO UNLESS SNOW DEVELOPS...WE SHOULD SEE VFR
CONDITIONS WITH ZR/PL FOR A FEW HRS AT THE ONSET. AS THE WARMER
AIR GRADUALLY MOVES IN...CEILINGS AND VISIBILITIES WILL LOWER
THROUGH THE DAY. IFR AND LOWER CONDITIONS LOOK LIKELY BY 18Z THU.
BEYOND 18Z A PROLONGED PERIOD OF SUB IFR LOOKS LIKELY TO OCCUR FOR
ALL SITES.
&&
.HYDROLOGY...
ISSUED AT 141 PM EST TUE FEB 18 2014
RAIN COULD BE HEAVY AT TIMES THURSDAY INTO THURSDAY NIGHT AS
TEMPERATURES WARM UP. UPWARDS OF AN INCH OF RAIN IS FORECASTED. WE
WILL SEE SOME RUNOFF WHICH MAY LEAD TO URBAN AND POOR DRAINAGE
FLOODING. THE WARM TEMPERATURES WILL LAST LESS THAN 24 HRS THEN WE
DROP BACK DOWN BELOW FREEZING. THUS IT APPEARS THAT NOT ENOUGH
RUNOFF WILL OCCUR TO TRIGGER WIDESPREAD FLOODING...INCLUDING ICE
BREAKUP AND JAMS. WILL NEED TO MONITOR THE SITUATION CLOSELY IN
THE COMING DAYS.
ICE JAMS IN RIVERS TEND TO FORM NEAR SHARP BENDS...IN SHALLOW
AREAS...AND NEAR OBSTRUCTIONS...LIKE BRIDGES AND ISLANDS. ICE
BREAKUP ON RIVERS CAN OCCUR WHENEVER THE RIVER STAGE RISES 1.5 TO 3
TIMES THE RIVER ICE THICKNESS. ICE JAMS ON RIVERS CAN RESULT IN
UNPREDICTABLE RAPID RISES ON RIVERS.
UNTIL THEN...LITTLE CHANGE IS EXPECTED ON AREA RIVERS AS ICE REMAINS
LARGELY LOCKED IN PLACE ACROSS MOST RIVERS AND STREAMS AS FLOW IS
NEAR NORMAL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...93
SHORT TERM...93
LONG TERM...MEADE
AVIATION...MJS
HYDROLOGY...MJS
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
257 PM CST Wed Feb 19 2014
.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 18z TAFs through 18z Thursday Afternoon)
Issued at 1202 PM CST Wed Feb 19 2014
Still looks like VFR conditions through 00Z before thunderstorms
develop across central and northeast Missouri between 00-06Z.
These storms will slowly move eastward overnight tonight and
eventually move into the St. Louis metro TAF sites between 09-11Z.
Low MVFR or IFR conditions will develop in the thunderstorms. LLWS
will also develop overnight as a low level jet will set up over
the area. A cold front will move across the area on Tuesday which
may produce another round of thunderstorms during the afternoon at
the St. Louis metro TAF sites.
Specifics for KSTL: Expect dry and VFR conditions into the early
evening hours before thunderstorm chances increase during the late
evening and overnight hours. Current thinking is that thunderstorms
over central Missouri will move into the TAF site around 09Z. An
additional line of storms is expected to develop ahead of a cold
front on Thursday afternoon. Timing is uncertain, and current
18-20Z group may need to be changed in future TAF issuances based
on cold front timing.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...FLOOD WATCH from Midnight CST tonight 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 from Midnight CST tonight through Thursday afternoon
FOR Adams IL-Brown IL-Greene IL-Macoupin IL-Montgomery IL-
Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
349 PM EST WED FEB 19 2014
.SYNOPSIS...
DEEPENING LOW PRESSURE IN THE GULF OF MAINE THIS EVENING WILL ALLOW
FOR LINGERING SNOW SHOWERS AND FLURRIES ACROSS THE NORTHERN
ADIRONDACKS AND CENTRAL AND NORTHERN GREEN MOUNTAINS THROUGH
MIDNIGHT TONIGHT. OTHERWISE...IT WILL GENERALLY BE DRY WITH PARTIAL
CLEARING BY DAYBREAK. HIGH PRESSURE BRIEFLY BUILDS EASTWARD ACROSS
THE REGION THURSDAY...WITH PARTLY SUNNY SKIES AND MILD AFTERNOON
TEMPERATURES REACHING THE UPPER 30S TO LOWER 40S. A STRONGER STORM
SYSTEM WILL AFFECT THE AREA THURSDAY NIGHT INTO FRIDAY. A PERIOD
OF SLEET AND FREEZING RAIN IS EXPECTED...ESPECIALLY EAST OF THE
GREEN MOUNTAINS EARLY FRIDAY MORNING...AND WILL LIKELY MAKE FOR A
DIFFICULT FRIDAY MORNING COMMUTE ACROSS CENTRAL AND EASTERN VERMONT.
THE WINTRY MIX CHANGES TO ALL RAIN LATER FRIDAY MORNING WITH
LOCALLY GUSTY WINDS. HIGHS FRIDAY WILL REACH THE 40S TO AROUND
50...WARMEST IN THE CHAMPLAIN AND ST. LAWRENCE VALLEYS. A TREND
BACK TOWARD BELOW NORMAL TEMPERATURES IS EXPECTED FOR NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM THURSDAY MORNING/...
AS OF 315 PM EST WEDNESDAY...STEADY SNOW IS ENDING ACROSS
CENTRAL/ERN VT LATE THIS AFTN AS DEVELOPING SFC LOW ACROSS SERN MA
TRACKS NEWD INTO THE GULF OF MAINE. RECEIVED REPORTS OF 3-4"
ACROSS RUTLAND AND WINDSOR COUNTIES THIS AFTERNOON...SO LIKELY
SOME LINGERING SLOW TRAVEL THRU THE EVENING COMMUTE DUE TO SNOW
COVERED ROADWAYS.
HIGH RESOLUTION MODELS CONTINUE TO INDICATE LINGERING FLURRY OR
LIGHT SNOW SHOWER ACTIVITY IN THE NRN ADIRONDACKS AND NRN GREEN
MTNS. THIS IS CONSISTENT WITH INCREASING TREND IN RADAR
REFLECTIVITY ACROSS ERN FRANKLIN VT/CHITTENDEN COUNTY DURING THE
PAST HOUR. MAY SEE LOCALIZED 1-2" AMTS ACROSS THE MTNS
THIS EVENING...WITH ACTIVITY DIMINISHING AFTER MIDNIGHT. PARTIAL
CLEARING IS EXPECTED BY DAYBREAK AREAWIDE AS SHORTWAVE RIDGE
BUILDS INTO NRN NY TOWARD 12Z WEDNESDAY. LOWS WILL BE ABOVE
AVERAGE TONIGHT AS AIR MASS CONTINUES TO MODERATE...AND CLOUDS
LIMIT RADIATIVE COOLING TO SOME EXTENT. LOOKING FOR LOWS GENERALLY
IN THE UPPER TEENS TO MID 20S...HIGHEST IN THE CHAMPLAIN VLY.
&&
.SHORT TERM /7 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 315 PM EST WEDNESDAY...QUIET AND MILD CONDITIONS THURSDAY.
SFC RIDGE AND SHORTWAVE RIDGING ALOFT WILL BISECT THE NORTH
COUNTRY AT 18Z. 850MB TEMPS MODERATE TO -1C TO -3C...AND THIS
SHOULD ALLOW SFC TEMPS TO RISE INTO UPPER 30S TO LOWER 40S. MOSTLY
SUNNY IN THE MORNING...BUT SHOULD SEE AN INCREASE IN MID-UPR LEVEL
CLOUD COVER DURING THE AFTN WITH ONSET OF ISENTROPIC ASCENT IN
ADVANCE OF NEXT FRONTAL SYSTEM.
RAPIDLY DEEPENING SFC CYCLONE (970MB BY 12Z FRIDAY) TRACKING NEWD
THRU THE CENTRAL GREAT LAKES THURSDAY NIGHT IS ASSOCIATED WITH A
LEADING WARM FRONT AND STRONG SLY LOW-LEVEL JET WHICH WILL BE
LIFTING THRU THE NORTH COUNTRY. THE 12Z NWP GUIDANCE IS A BIT
QUICKER WITH ONSET OF MIXED WINTRY PRECIPITATION ACROSS THE
REGION...WITH STRONG WAA BRINGING WIDESPREAD STRATIFORM PCPN INTO
THE AREA. PRECIPITATION WILL REACH THE ADIRONDACKS AND S-CENTRAL
VT BY MIDNIGHT...AND OVERSPREAD THE REMAINDER OF THE REGION DURING
THE PRE-DAWN HOURS. IT APPEARS A QUICK CHANGE FROM SNOW TO
SLEET/FREEZING RAIN IS LIKELY IN THE ADIRONDACKS...NRN ST. LAWRENCE
VALLEY...AND POINTS EAST OF THE GREEN MTNS DURING THE PRE-DAWN HRS
FRIDAY...LASTING INTO THE MORNING COMMUTE. IN THE CHAMPLAIN
VALLEY...WET SNOW TO MAINLY RAIN EXPECTED WITH LOCALLY ABOVE 32F
TEMPS. SFC TEMPS REMAIN 28-32F LONGEST EAST OF THE GREEN
MTNS...AND WITH TEMPS REACHING +4 TO +6C IN SOUNDING WARM "NOSE"
BETWEEN 850-800MB...THERMODYNAMIC PROFILES STRONGLY FAVOR PERIOD
OF FREEZING RAIN ACROSS CENTRAL/ERN VT. ICY ROAD CONDITIONS WITH
COLD GROUND CONDITIONS WILL MAKE FOR A HAZARDOUS MORNING COMMUTE
AWAY FROM THE CHAMPLAIN VALLEY...ESPECIALLY CENTRAL/ERN VT. A
WINTER WEATHER ADVISORY MAY EVENTUALLY BE REQUIRED AS WE GET
CLOSER TO THE EVENT. TOTAL ICE WILL GENERALLY REMAIN BELOW 0.2"
MAX...SO MAIN IMPACT WILL BE TO TRANSPORTATION. ANY SNOW/SLEET AT
THE START OF THE PRECIPITATION EVENT WILL AMOUNT TO 2" OR LESS.
SOME GUSTY DOWNSLOPE WINDS ARE ALSO POSSIBLE EARLY FRIDAY...SE
20-30 WITH GUSTS TO 40 MPH ALONG THE WRN SLOPES OF THE GREEN MTNS.
THIS WOULD MAINLY OCCUR BETWEEN 06-15Z FRIDAY. FOLLOWING COLD
FRONTAL PASSAGE...STEEP LOW-LEVEL LAPSE RATES AND CHANNELED FLOW
IN THE ST. LAWRENCE VALLEY WILL LIKELY YIELD SOME SW GUSTS 40-45
MPH. WINDS SHOULD NOT BE QUITE AS STRONG ELSEWHERE.
QPF AMTS EXPECTED TO RANGE FROM 0.4"-0.8"...HIGHEST IN THE
ADIRONDACKS WITH UPSLOPE FLOW AND INTO THE CENTRAL GREEN MTNS.
LOCAL SHADOWING AFFECTS IN THE CHAMPLAIN VALLEY WILL RESULT IN
TOTAL PRECIPITATION ON THE LOW END OF THE RANGE. DESPITE TEMPS
WELL INTO THE 40S TO NEAR 50F...NOT ANTICIPATING ANY SIGNIFICANT
HYDRO CONCERNS AS OUTLINED IN HYDRO SECTION BELOW.
CLEARING FRIDAY NIGHT WITH WLY FLOW. AIR MASS IS NOT PARTICULARLY
COLD IN THE WAKE OF THE COLD FRONT PER NAM/GFS THERMAL FIELDS.
KEPT LOWS GENERALLY IN THE 20S FOR FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 250 PM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE OF
FCSTS WITH REGARDS TO LARGE SCALE SYNOPTIC PATTERN WHICH SUPPORTS
DEEP FULL LATITUDE MID/UPPER LVL TROF DEVELOPING ACRS THE EASTERN
CONUS. THIS WL SUPPORT A TREND TWD BLW NORMAL TEMPS BY EARLY NEXT
WEEK...ALONG WITH BLW NORMAL CHCS FOR PRECIP. GIVEN THE POSITION
OF TROF AXIS AND SFC HIGH PRES...EXPECTING A FAST WESTERLY
CONFLUENT FLW ACRS OUR CWA...WITH NO INTERACTION OF SUB TROPICAL
MOISTURE INTO OUR REGION. THE COMBINATION OF S/W ENERGY IN THE FLW
ALOFT AND SFC TROFS EVERY COUPLE OF DAYS...WL RESULT IN MAINLY ON
AND OFF MTN SNOW SHOWERS THRU THE PERIOD...BUT ACCUMULATIONS WL BE
LIGHT. TEMPS WL START MUCH ABOVE NORMAL FOR SAT WITH PROGGED 925MB
TEMPS RANGING FROM -2C SLV TO +2C CT RIVER VALLEY...SUPPORTING L/M
30S MTNS L/M 40S VALLEYS...ESPECIALLY LWR CT RIVER VALLEY. BY
SUNDAY...925MB TEMPS FALL ANOTHER 3 TO 6 DEGREES SUPPORTING HIGHS
BACK INTO THE 20S MTNS TO 30S VALLEYS. THIS TREND OF COOLING LLVL
THERMAL PROFILES BY 3 TO 6 DEGREES A DAY CONTINUES FOR MONDAY INTO
TUESDAY...WITH EXPECTED HIGHS IN THE TEENS TO L/M20S ANTICIPATED.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...IFR CONDITIONS WL OCCUR AT RUT/MPV THRU 21Z
TODAY...WITH POTENTIAL IFR CIGS/VIS DEVELOPING AT SLK BY 23Z THIS
EVENING. CRNT RADAR SHOWS BAND OF MODERATE SNOW LIFTING ACRS
CENTRAL/SOUTHERN VT...IMPACTING MPV/RUT WITH VIS BLW 1SM. BASED ON
RAP13 AND HRRR MODEL PROGGED COMPOSITE REFLECTIVITY EXPECT THIS
ACTIVITY TO BE EAST OF OUR TAF SITES BY 21Z WITH MAINLY MVFR
CONDITIONS PREVAILING. AT SLK THINKING WEAK SFC TROF WL SHIFT THE
WINDS TO THE WEST/NORTHWEST THIS EVENING WITH LLVL CLOUDS AND
LIGHT SNOW DEVELOPING. THIS WL RESULT IN A PERIOD OF IFR
CONDITIONS AT SLK WITH VIS BLW 2SM AND CIGS BLW OVC 1000 FT.
ELSEWHERE...EXPECTING MAINLY VFR WITH BRIEF PERIODS OF MVFR AT
MSS/BTV THRU THIS EVENING. WEAK SFC RIDGE WITH VFR CONDITIONS WL
PREVAIL LATE TONIGHT INTO 18Z WEDS AT OUR TAF SITES.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY...
VFR CONDITIONS WITH THICKENING CLOUDS THRU 00Z FRIDAY. SFC WARM
FRNT WL RESULT IN MIXED PRECIP DEVELOPING BY 06Z FRIDAY WITH SOME
ICE ACCUMULATION POSSIBLE AT MPV...ALONG WITH WIDESPREAD MVFR/IFR
CONDITIONS LIKELY BTWN 06Z-12Z FRIDAY. ANOTHER BAND OF MAINLY RAIN
SHOWERS OCCURS FRIDAY WITH MVFR CONDITIONS...WITH EXCEPTION OF IFR
POSSIBLE AT MSS/SLK/MPV. ALSO...WITH WARM TEMPS MOVING OVER
RELATIVELY COLD SFC TEMPS/SNOWPACK AREAS OF FOG/BR WL BE POSSIBLE
IN THE DEEPER PROTECTED VALLEY LOCATIONS OF VT/NY FRIDAY INTO
SATURDAY. STRONG LLVL JET WL RESULT IN AREAS OF LLVL WS ON
FRIDAY...ESPECIALLY AT MSS WITH NORTHEAST SFC WINDS AND SW WINDS
ALOFT AT 1500 FEET AND AT MPV WITH LIGHT SFC WINDS ANTICIPATED AND
STRONG 1000 AGL WINDS OF 45 TO 50 KNTS. GUSTY SE WINDS OF 30 TO 35
KNTS WL BE POSSIBLE AT RUTLAND ON FRIDAY MORNING...WHICH WL SHIFT
TO THE SOUTHWEST AND BECM GUSTY AT MSS/SLK/PBG/BTV DURING THE
AFTN/EVENING OF FRIDAY. OTHERWISE...DRY SLOT WL RESULT IN VFR
CONDITIONS DEVELOPING FRIDAY NIGHT AND PREVAILING INTO SUNDAY.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDROLOGICAL ISSUES FORESEEN WITH BRIEF WARMUP
THURSDAY AND FRIDAY AS SNOWPACK IS NOT RIPE FOR RAPID SNOWMELT. MOST
OF THE EXPECTED PRECIPITATION FRIDAY (BASIN AVG AROUND 0.40"-0.70")
IS EXPECTED TO BE ABSORBED INTO THE SNOWPACK GIVEN CURRENT
CHARACTERISTICS OF SNOWPACK. THAWING DEGREE HOURS REACH NEAR 300
ACROSS A LIMITED AREA OF ADDISON/RUTLAND COUNTY AND IN ST. LAWRENCE
COUNTY NY...WHERE TEMPERATURES WILL APPROACH 48-50F FOR A TIME
FRIDAY. SHOULD ANY MINOR ICE JAMS DEVELOP FRIDAY OR FRIDAY
NIGHT...WILL LIKELY BE CONFINED TO RUTLAND/ADDISON/ST. LAWRENCE
COUNTIES...AND ON THE SMALLER RIVERS AND STREAMS. LOW PROBABILITY
OF ANY ICE JAM FLOODING AT THIS POINT...BUT WE WILL CONTINUE TO
MONITOR.
&&
.EQUIPMENT...
DAMAGED EQUIPMENT HAS RESULTED IN AN AUDIBLE HUM ON THE MOUNT
ASCUTNEY NOAA WEATHER RADIO BROADCAST (WXM-44). OUR TECHNICIANS
ARE AWARE OF THE PROBLEM AND WILL RESOLVE THE ISSUE AS QUICKLY AS
POSSIBLE. REPAIRS MAY INVOLVE COORDINATION AND ACCESS BY
TELCO...INCLUDING PARTS ACQUISITION. THIS MAY TAKE 1-2 DAYS TO
RESOLVE. IN THE MEANTIME...WE APOLOGIZE FOR ANY DIFFICULTIES IN
HEARING THE BROADCAST FROM MOUNT ASCUTNEY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
HYDROLOGY...BANACOS
EQUIPMENT...BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
247 PM EST WED FEB 19 2014
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL BRING PERIODS OF LIGHT SNOW TO THE
REGION THIS AFTERNOON INTO EARLY TONIGHT. A STRONGER STORM SYSTEM WILL
AFFECT THE AREA THURSDAY NIGHT INTO FRIDAY WITH MILDER TEMPERATURES
ALONG WITH A MIX OF WINTRY PRECIPITATION AND LOCALLY GUSTY WINDS.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 1230 PM EST WEDNESDAY...NO SIGNIFICANT CHANGES TO PREVIOUS
FORECAST. RADAR TRENDS SUGGEST 1-2 HOUR PERIOD OF MODERATE SNOW
ACROSS S-CENTRAL VT NEWD ACROSS CENTRAL/ERN VT THIS AFTN. SHOULD
SEE A QUICK 2-3" OF SNOW THRU 21Z BEFORE BEST UVV SHIFTS EWD. A
SPECIAL WX STATEMENT HAS BEEN ISSUED TO COVER THIS
POTENTIAL...WITH SOME SLOW TRAVEL CONDITIONS EXPECTED CENTRAL/ERN
VT THIS AFTN. REMAINDER OF THE FCST IS UNCHANGED.
PREVIOUS DISCUSSION...OVERCAST SKIES IN PLACE ACROSS THE NORTH
COUNTRY THIS MORNING IN ADVANCE OF A SHORTWAVE TROUGH CROSSING THE
EASTERN GREAT LAKES REGION AND ASSOCIATED SFC TROUGH ACROSS SERN
ONTARIO/WRN NY. SIMILAR TO YESTERDAY...A SECONDARY LOW PRESSURE
SYSTEM IS EXPECTED TO DEVELOP ACROSS SOUTHERN NEW ENGLAND THIS
AFTN AND THEN DEEPEN ACROSS THE GULF OF MAINE THIS EVENING. MOST
OF THE ASSOCIATED PRECIPITATION IS FOCUSED SOUTH AND EAST OF OUR
FORECAST AREA. THAT SAID...NAM...BTV-4KM AND 12KM WRF DO SHOW AN
INCREASE IN PRECIPITATION COVERAGE ACROSS VERMONT AROUND
18Z...LASTING THRU THIS EVENING. NO SIGNIFICANT CHANGES OTHER THAN
TO LOWER POPS/QPF A BIT ACROSS NRN NY. OVERALL LOOKING AT 0.10 TO
0.15" ACROSS VT AND < 0.10" ACROSS NRN NY. GENERALLY LOOKING AT
SNOW...ALTHOUGH PBL TEMPS WARM ABOVE FREEZING AND NEAR-SFC WARM
LAYER SHOULD BE ENOUGH FOR CONDITIONAL RAIN/SNOW MIX WITH ANYTHING
THAT FALLS ACROSS SWRN ST. LAWRENCE COUNTY TODAY.
ELSEWHERE...VALLEY TEMPS REACH THE MID 30S ACROSS WRN VT...SO
LIKELY LOOKING AT LIMITED ACCUMULATIONS ON ROAD SURFACES. SNOWFALL
FCST IS A DUSTING TO 1" ACROSS THE CHAMPLAIN VALLEY AND GENERALLY
1-3" ACROSS CENTRAL AND ERN VT. HIGHEST SNOW TOTALS ARE LIKELY
ACROSS THE CENTRAL GREEN MTNS THIS AFTN THRU THE FIRST PART OF
TONIGHT. HIGH TEMPS RANGE FROM 34-37F IN THE CHAMPLAIN VALLEY TO
30-33F EAST OF THE GREEN MTNS. HIGHS IN THE LOWER-MID 40S EXPECTED
ACROSS SRN ST. LAWRENCE COUNTY NY.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY NIGHT/...
AS OF 459 AM EST WEDNESDAY...CHANCES FOR SNOW WILL TAPER OFF
TONIGHT...BUT AN ADDITIONAL INCH OR TWO IS POSSIBLE OVER NORTH
CENTRAL AND NORTHEAST VERMONT BEFORE IT WINDS DOWN BY AROUND
MIDNIGHT. EXPECT PLENTY OF CLOUDS HOWEVER... ESPECIALLY NORTH.
LOOK FOR MIN TEMPS IN THE UPPER TEENS TO MID 20S.
THURSDAY WILL BE QUIET AS SURFACE HIGH SLIDES EAST ACROSS THE REGION
AND REACHES THE EAST COAST BY EVENING. EXPECT A DECREASE IN CLOUD
COVER IN THE MORNING...FOLLOWED BY AN INCREASE IN CLOUDS AGAIN
LATER IN THE DAY IN ADVANCE OF NEXT AREA OF LOW PRESSURE
AND ASSOCIATED FRONTAL SYSTEM. IT SHOULD REMAIN MOSTLY DRY THROUGH
THE DAYLIGHT HOURS HOWEVER. WINDS TURN INTO THE SOUTH IN BETWEEN
DEPARTING HIGH AND APPROACHING LOW. WITH 850 MB TEMPS CLIMBING TO
NEAR 0C BY 00Z FRIDAY...WE CAN EXPECT A RATHER MILD DAY WITH HIGHS
IN THE MID 30S TO AROUND 40.
STRONG/HIGH AMPLITUDE MID-LEVEL TROUGH ACROSS THE CENTRAL
MISSISSIPPI VALLEY THURSDAY NIGHT RESULTS IN RAPIDLY DEEPENING LOW
PRESSURE ACROSS THE GREAT LAKES REGION (968MB PER 00Z GFS AT 12Z
FRIDAY OVER LAKE SUPERIOR). STRONG SOUTHERLY LOW-LEVEL JET DEVELOPS
DURING THURSDAY NIGHT...WITH 55-60 KTS AT 850MB BY DAYBREAK FRIDAY.
STRONG WARM FRONTAL ASCENT WILL BRING STRATIFORM PRECIPITATION TO
THE REGION...ESPECIALLY AFTER MIDNIGHT THURSDAY NIGHT.
PRECIPITATION TYPE WILL BE AN ISSUE ACROSS MUCH OF THE AREA THURSDAY
NIGHT. ABOVE FREEZING TEMPS LIKELY IN THE CHAMPLAIN VALLEY
SUPPORTING MAINLY RAIN...ALTHOUGH SOME EVAPORATIONAL COOLING AT
ONSET OF PRECIPITATION MAY SUPPORT A BRIEF PERIOD OF SLEET AND SNOW.
MODEL SOUNDINGS INDICATE THAT TEMPS ACROSS THE REST OF THE FORECAST
AREA WILL BE BELOW FREEZING NEAR THE SURFACE WITH FAVORABLE
PROFILES FOR A PERIOD OF SLEET AND POSSIBLE FREEZING RAIN. LOOK FOR
ANY ICING TO BE MINIMAL AND OF SHORT DURATION OVER MUCH OF THE
ADIRONDACKS AND SAINT LAWRENCE VALLEY. EAST OF THE GREEN
MOUNTAINS...SOME AREAS WILL SEE THE THREAT OF FREEZING RAIN LINGER
INTO MID MORNING FRIDAY AS TEMPS STRUGGLE TO CLIMB ABOVE FREEZING IN
THE SHELTERED VALLEYS. THIS MAY RESULT IN SOME TRAVEL IMPACT
DURING THE PRE-DAWN HRS INTO THE EARLY MORNING COMMUTE ON FRIDAY.
ALSO LOOKING AT LOCALLY STRONG AND GUSTY WINDS...ESPECIALLY ALONG
THE WESTERN SLOPES WHERE GUSTS MAY TOP 40 MPH FOR A TIME. THESE
WINDS WILL SHIFT TO THE SOUTHWEST WITH FRONTAL PASSAGE FROM LATE
FRIDAY MORNING THROUGH AFTERNOON ACROSS THE AREA...WITH STRONGEST
WINDS POST FROPA OVER SAINT LAWRENCE VALLEY.
AS FOR THE PRECIPITATION...THE WARM AIR ADVECTION RAIN/FREEZING RAIN
WILL BE LATE THURSDAY NIGHT THROUGH EARLY FRIDAY. MAYBE A BRIEF LULL
IN THE PRECIPITATION BEFORE MORE CONVECTIVE TYPE SHOWERS ASSOCIATED
WITH COLD FRONT QUICKLY OVERSPREAD THE REGION FROM WEST TO EAST.
EXPECT FROPA IN SAINT LAWRENCE VALLEY BY 15Z FRIDAY AND IN
EASTERN VERMONT BY AROUND 21Z. THIS PRECIPITATION EXPECTED TO BE
ALL IN THE FORM OF RAIN WITH MAX TEMPS RANGING FROM THE UPPER 30S
EASTERN VERMONT TO THE UPPER 40S IN ACROSS NORTHERN NEW YORK AND
SOUTHWEST VERMONT. PRECIPITATION TOTALS FROM THURSDAY NIGHT
THROUGH FRIDAY EXPECTED TO RANGE FROM ONE HALF TO ONE INCH...WITH
SOME LOCALLY HIGHER AMOUNTS POSSIBLE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 250 PM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE OF
FCSTS WITH REGARDS TO LARGE SCALE SYNOPTIC PATTERN WHICH SUPPORTS
DEEP FULL LATITUDE MID/UPPER LVL TROF DEVELOPING ACRS THE EASTERN
CONUS. THIS WL SUPPORT A TREND TWD BLW NORMAL TEMPS BY EARLY NEXT
WEEK...ALONG WITH BLW NORMAL CHCS FOR PRECIP. GIVEN THE POSITION
OF TROF AXIS AND SFC HIGH PRES...EXPECTING A FAST WESTERLY
CONFLUENT FLW ACRS OUR CWA...WITH NO INTERACTION OF SUB TROPICAL
MOISTURE INTO OUR REGION. THE COMBINATION OF S/W ENERGY IN THE FLW
ALOFT AND SFC TROFS EVERY COUPLE OF DAYS...WL RESULT IN MAINLY ON
AND OFF MTN SNOW SHOWERS THRU THE PERIOD...BUT ACCUMULATIONS WL BE
LIGHT. TEMPS WL START MUCH ABOVE NORMAL FOR SAT WITH PROGGED 925MB
TEMPS RANGING FROM -2C SLV TO +2C CT RIVER VALLEY...SUPPORTING L/M
30S MTNS L/M 40S VALLEYS...ESPECIALLY LWR CT RIVER VALLEY. BY
SUNDAY...925MB TEMPS FALL ANOTHER 3 TO 6 DEGREES SUPPORTING HIGHS
BACK INTO THE 20S MTNS TO 30S VALLEYS. THIS TREND OF COOLING LLVL
THERMAL PROFILES BY 3 TO 6 DEGREES A DAY CONTINUES FOR MONDAY INTO
TUESDAY...WITH EXPECTED HIGHS IN THE TEENS TO L/M20S ANTICIPATED.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...IFR CONDITIONS WL OCCUR AT RUT/MPV THRU 21Z
TODAY...WITH POTENTIAL IFR CIGS/VIS DEVELOPING AT SLK BY 23Z THIS
EVENING. CRNT RADAR SHOWS BAND OF MODERATE SNOW LIFTING ACRS
CENTRAL/SOUTHERN VT...IMPACTING MPV/RUT WITH VIS BLW 1SM. BASED ON
RAP13 AND HRRR MODEL PROGGED COMPOSITE REFLECTIVITY EXPECT THIS
ACTIVITY TO BE EAST OF OUR TAF SITES BY 21Z WITH MAINLY MVFR
CONDITIONS PREVAILING. AT SLK THINKING WEAK SFC TROF WL SHIFT THE
WINDS TO THE WEST/NORTHWEST THIS EVENING WITH LLVL CLOUDS AND
LIGHT SNOW DEVELOPING. THIS WL RESULT IN A PERIOD OF IFR
CONDITIONS AT SLK WITH VIS BLW 2SM AND CIGS BLW OVC 1000 FT.
ELSEWHERE...EXPECTING MAINLY VFR WITH BRIEF PERIODS OF MVFR AT
MSS/BTV THRU THIS EVENING. WEAK SFC RIDGE WITH VFR CONDITIONS WL
PREVAIL LATE TONIGHT INTO 18Z WEDS AT OUR TAF SITES.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY...
VFR CONDITIONS WITH THICKENING CLOUDS THRU 00Z FRIDAY. SFC WARM
FRNT WL RESULT IN MIXED PRECIP DEVELOPING BY 06Z FRIDAY WITH SOME
ICE ACCUMULATION POSSIBLE AT MPV...ALONG WITH WIDESPREAD MVFR/IFR
CONDITIONS LIKELY BTWN 06Z-12Z FRIDAY. ANOTHER BAND OF MAINLY RAIN
SHOWERS OCCURS FRIDAY WITH MVFR CONDITIONS...WITH EXCEPTION OF IFR
POSSIBLE AT MSS/SLK/MPV. ALSO...WITH WARM TEMPS MOVING OVER
RELATIVELY COLD SFC TEMPS/SNOWPACK AREAS OF FOG/BR WL BE POSSIBLE
IN THE DEEPER PROTECTED VALLEY LOCATIONS OF VT/NY FRIDAY INTO
SATURDAY. STRONG LLVL JET WL RESULT IN AREAS OF LLVL WS ON
FRIDAY...ESPECIALLY AT MSS WITH NORTHEAST SFC WINDS AND SW WINDS
ALOFT AT 1500 FEET AND AT MPV WITH LIGHT SFC WINDS ANTICIPATED AND
STRONG 1000 AGL WINDS OF 45 TO 50 KNTS. GUSTY SE WINDS OF 30 TO 35
KNTS WL BE POSSIBLE AT RUTLAND ON FRIDAY MORNING...WHICH WL SHIFT
TO THE SOUTHWEST AND BECM GUSTY AT MSS/SLK/PBG/BTV DURING THE
AFTN/EVENING OF FRIDAY. OTHERWISE...DRY SLOT WL RESULT IN VFR
CONDITIONS DEVELOPING FRIDAY NIGHT AND PREVAILING INTO SUNDAY.
&&
.EQUIPMENT...
DAMAGED EQUIPMENT HAS RESULTED IN AN AUDIBLE HUM ON THE MOUNT
ASCUTNEY NOAA WEATHER RADIO BROADCAST (WXM-44). OUR TECHNICIANS
ARE AWARE OF THE PROBLEM AND WILL RESOLVE THE ISSUE AS QUICKLY AS
POSSIBLE. REPAIRS MAY INVOLVE COORDINATION AND ACCESS BY
TELCO...INCLUDING PARTS ACQUISITION. THIS MAY TAKE 1-2 DAYS TO
RESOLVE. IN THE MEANTIME...WE APOLOGIZE FOR ANY DIFFICULTIES IN
HEARING THE BROADCAST FROM MOUNT ASCUTNEY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS/RJS
NEAR TERM...BANACOS
SHORT TERM...RJS
LONG TERM...TABER
AVIATION...TABER
EQUIPMENT...BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
102 PM EST WED FEB 19 2014
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL BRING PERIODS OF LIGHT SNOW TO THE
REGION THIS AFTERNOON INTO EARLY TONIGHT. A STRONGER STORM SYSTEM WILL
AFFECT THE AREA THURSDAY NIGHT INTO FRIDAY WITH MILDER TEMPERATURES
ALONG WITH A MIX OF WINTRY PRECIPITATION AND LOCALLY GUSTY WINDS.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 1230 PM EST WEDNESDAY...NO SIGNIFICANT CHANGES TO PREVIOUS
FORECAST. RADAR TRENDS SUGGEST 1-2 HOUR PERIOD OF MODERATE SNOW
ACROSS S-CENTRAL VT NEWD ACROSS CENTRAL/ERN VT THIS AFTN. SHOULD
SEE A QUICK 2-3" OF SNOW THRU 21Z BEFORE BEST UVV SHIFTS EWD. A
SPECIAL WX STATEMENT HAS BEEN ISSUED TO COVER THIS
POTENTIAL...WITH SOME SLOW TRAVEL CONDITIONS EXPECTED CENTRAL/ERN
VT THIS AFTN. REMAINDER OF THE FCST IS UNCHANGED.
PREVIOUS DISCUSSION...OVERCAST SKIES IN PLACE ACROSS THE NORTH
COUNTRY THIS MORNING IN ADVANCE OF A SHORTWAVE TROUGH CROSSING THE
EASTERN GREAT LAKES REGION AND ASSOCIATED SFC TROUGH ACROSS SERN
ONTARIO/WRN NY. SIMILAR TO YESTERDAY...A SECONDARY LOW PRESSURE
SYSTEM IS EXPECTED TO DEVELOP ACROSS SOUTHERN NEW ENGLAND THIS
AFTN AND THEN DEEPEN ACROSS THE GULF OF MAINE THIS EVENING. MOST
OF THE ASSOCIATED PRECIPITATION IS FOCUSED SOUTH AND EAST OF OUR
FORECAST AREA. THAT SAID...NAM...BTV-4KM AND 12KM WRF DO SHOW AN
INCREASE IN PRECIPITATION COVERAGE ACROSS VERMONT AROUND
18Z...LASTING THRU THIS EVENING. NO SIGNIFICANT CHANGES OTHER THAN
TO LOWER POPS/QPF A BIT ACROSS NRN NY. OVERALL LOOKING AT 0.10 TO
0.15" ACROSS VT AND < 0.10" ACROSS NRN NY. GENERALLY LOOKING AT
SNOW...ALTHOUGH PBL TEMPS WARM ABOVE FREEZING AND NEAR-SFC WARM
LAYER SHOULD BE ENOUGH FOR CONDITIONAL RAIN/SNOW MIX WITH ANYTHING
THAT FALLS ACROSS SWRN ST. LAWRENCE COUNTY TODAY.
ELSEWHERE...VALLEY TEMPS REACH THE MID 30S ACROSS WRN VT...SO
LIKELY LOOKING AT LIMITED ACCUMULATIONS ON ROAD SURFACES. SNOWFALL
FCST IS A DUSTING TO 1" ACROSS THE CHAMPLAIN VALLEY AND GENERALLY
1-3" ACROSS CENTRAL AND ERN VT. HIGHEST SNOW TOTALS ARE LIKELY
ACROSS THE CENTRAL GREEN MTNS THIS AFTN THRU THE FIRST PART OF
TONIGHT. HIGH TEMPS RANGE FROM 34-37F IN THE CHAMPLAIN VALLEY TO
30-33F EAST OF THE GREEN MTNS. HIGHS IN THE LOWER-MID 40S EXPECTED
ACROSS SRN ST. LAWRENCE COUNTY NY.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 459 AM EST WEDNESDAY...CHANCES FOR SNOW WILL TAPER OFF
TONIGHT...BUT AN ADDITIONAL INCH OR TWO IS POSSIBLE OVER NORTH
CENTRAL AND NORTHEAST VERMONT BEFORE IT WINDS DOWN BY AROUND
MIDNIGHT. EXPECT PLENTY OF CLOUDS HOWEVER... ESPECIALLY NORTH.
LOOK FOR MIN TEMPS IN THE UPPER TEENS TO MID 20S.
THURSDAY WILL BE QUIET AS SURFACE HIGH SLIDES EAST ACROSS THE REGION
AND REACHES THE EAST COAST BY EVENING. EXPECT A DECREASE IN CLOUD
COVER IN THE MORNING...FOLLOWED BY AN INCREASE IN CLOUDS AGAIN
LATER IN THE DAY IN ADVANCE OF NEXT AREA OF LOW PRESSURE
AND ASSOCIATED FRONTAL SYSTEM. IT SHOULD REMAIN MOSTLY DRY THROUGH
THE DAYLIGHT HOURS HOWEVER. WINDS TURN INTO THE SOUTH IN BETWEEN
DEPARTING HIGH AND APPROACHING LOW. WITH 850 MB TEMPS CLIMBING TO
NEAR 0C BY 00Z FRIDAY...WE CAN EXPECT A RATHER MILD DAY WITH HIGHS
IN THE MID 30S TO AROUND 40.
STRONG/HIGH AMPLITUDE MID-LEVEL TROUGH ACROSS THE CENTRAL
MISSISSIPPI VALLEY THURSDAY NIGHT RESULTS IN RAPIDLY DEEPENING LOW
PRESSURE ACROSS THE GREAT LAKES REGION (968MB PER 00Z GFS AT 12Z
FRIDAY OVER LAKE SUPERIOR). STRONG SOUTHERLY LOW-LEVEL JET DEVELOPS
DURING THURSDAY NIGHT...WITH 55-60 KTS AT 850MB BY DAYBREAK FRIDAY.
STRONG WARM FRONTAL ASCENT WILL BRING STRATIFORM PRECIPITATION TO
THE REGION...ESPECIALLY AFTER MIDNIGHT THURSDAY NIGHT.
PRECIPITATION TYPE WILL BE AN ISSUE ACROSS MUCH OF THE AREA THURSDAY
NIGHT. ABOVE FREEZING TEMPS LIKELY IN THE CHAMPLAIN VALLEY
SUPPORTING MAINLY RAIN...ALTHOUGH SOME EVAPORATIONAL COOLING AT
ONSET OF PRECIPITATION MAY SUPPORT A BRIEF PERIOD OF SLEET AND SNOW.
MODEL SOUNDINGS INDICATE THAT TEMPS ACROSS THE REST OF THE FORECAST
AREA WILL BE BELOW FREEZING NEAR THE SURFACE WITH FAVORABLE
PROFILES FOR A PERIOD OF SLEET AND POSSIBLE FREEZING RAIN. LOOK FOR
ANY ICING TO BE MINIMAL AND OF SHORT DURATION OVER MUCH OF THE
ADIRONDACKS AND SAINT LAWRENCE VALLEY. EAST OF THE GREEN
MOUNTAINS...SOME AREAS WILL SEE THE THREAT OF FREEZING RAIN LINGER
INTO MID MORNING FRIDAY AS TEMPS STRUGGLE TO CLIMB ABOVE FREEZING IN
THE SHELTERED VALLEYS. THIS MAY RESULT IN SOME TRAVEL IMPACT
DURING THE PRE-DAWN HRS INTO THE EARLY MORNING COMMUTE ON FRIDAY.
ALSO LOOKING AT LOCALLY STRONG AND GUSTY WINDS...ESPECIALLY ALONG
THE WESTERN SLOPES WHERE GUSTS MAY TOP 40 MPH FOR A TIME. THESE
WINDS WILL SHIFT TO THE SOUTHWEST WITH FRONTAL PASSAGE FROM LATE
FRIDAY MORNING THROUGH AFTERNOON ACROSS THE AREA...WITH STRONGEST
WINDS POST FROPA OVER SAINT LAWRENCE VALLEY.
AS FOR THE PRECIPITATION...THE WARM AIR ADVECTION RAIN/FREEZING RAIN
WILL BE LATE THURSDAY NIGHT THROUGH EARLY FRIDAY. MAYBE A BRIEF LULL
IN THE PRECIPITATION BEFORE MORE CONVECTIVE TYPE SHOWERS ASSOCIATED
WITH COLD FRONT QUICKLY OVERSPREAD THE REGION FROM WEST TO EAST.
EXPECT FROPA IN SAINT LAWRENCE VALLEY BY 15Z FRIDAY AND IN
EASTERN VERMONT BY AROUND 21Z. THIS PRECIPITATION EXPECTED TO BE
ALL IN THE FORM OF RAIN WITH MAX TEMPS RANGING FROM THE UPPER 30S
EASTERN VERMONT TO THE UPPER 40S IN ACROSS NORTHERN NEW YORK AND
SOUTHWEST VERMONT. PRECIPITATION TOTALS FROM THURSDAY NIGHT
THROUGH FRIDAY EXPECTED TO RANGE FROM ONE HALF TO ONE INCH...WITH
SOME LOCALLY HIGHER AMOUNTS POSSIBLE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 459 AM EST WEDNESDAY...AFTER A PRETTY ACTIVE WEEK THE
WEATHER TURNS A BIT MORE QUIET FOR THE EXTENDED PORTION OF THE
FORECAST FROM FRIDAY NIGHT ONWARD. A FAIRLY BROAD AND SOMEWHAT
FLAT UPPER TROUGH SETTLES IN OVER MUCH OF THE NORTHERN CONUS WITH
A FAST WESTERLY FLOW ALOFT ALLOWING SEVERAL WEAK SHORTWAVE
TROUGHS TO QUICKLY TRAVERSE THE AREA. THE RESULT WILL BE ON AND
OFF LOW CHANCES FOR SOME LIGHT SNOW SHOWERS...BUT NO BIG SYSTEMS
WITH VERY LITTLE OVERALL QPF. TEMPS WILL RUN NORMAL TO SLIGHTLY
ABOVE FRIDAY NIGHT THROUGH SUNDAY WITH LOWS IN THE TEENS TO MID
20S...HIGHS SATURDAY IN THE MID 30S TO MID 40S...AND SUNDAY IN
THE MID 20S TO MID 30S. FROM SUNDAY NIGHT THROUGH THE END OF THE
PERIOD THE TREND WILL BE BACK TOWARDS BELOW NORMAL TEMPS THOUGH
WITH LOWS IN THE SINGLE DIGITS TO TEENS...AND HIGHS IN THE TEENS
TO LOWER 20S.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...IFR CONDITIONS WL OCCUR AT RUT/MPV THRU 21Z
TODAY...WITH POTENTIAL IFR CIGS/VIS DEVELOPING AT SLK BY 23Z THIS
EVENING. CRNT RADAR SHOWS BAND OF MODERATE SNOW LIFTING ACRS
CENTRAL/SOUTHERN VT...IMPACTING MPV/RUT WITH VIS BLW 1SM. BASED ON
RAP13 AND HRRR MODEL PROGGED COMPOSITE REFLECTIVITY EXPECT THIS
ACTIVITY TO BE EAST OF OUR TAF SITES BY 21Z WITH MAINLY MVFR
CONDITIONS PREVAILING. AT SLK THINKING WEAK SFC TROF WL SHIFT THE
WINDS TO THE WEST/NORTHWEST THIS EVENING WITH LLVL CLOUDS AND
LIGHT SNOW DEVELOPING. THIS WL RESULT IN A PERIOD OF IFR
CONDITIONS AT SLK WITH VIS BLW 2SM AND CIGS BLW OVC 1000 FT.
ELSEWHERE...EXPECTING MAINLY VFR WITH BRIEF PERIODS OF MVFR AT
MSS/BTV THRU THIS EVENING. WEAK SFC RIDGE WITH VFR CONDITIONS WL
PREVAIL LATE TONIGHT INTO 18Z WEDS AT OUR TAF SITES.
OUTLOOK 18Z THURSDAY THROUGH SUNDAY...
VFR CONDITIONS WITH THICKENING CLOUDS THRU 00Z FRIDAY. SFC WARM
FRNT WL RESULT IN MIXED PRECIP DEVELOPING BY 06Z FRIDAY WITH SOME
ICE ACCUMULATION POSSIBLE AT MPV...ALONG WITH WIDESPREAD MVFR/IFR
CONDITIONS LIKELY BTWN 06Z-12Z FRIDAY. ANOTHER BAND OF MAINLY RAIN
SHOWERS OCCURS FRIDAY WITH MVFR CONDITIONS...WITH EXCEPTION OF IFR
POSSIBLE AT MSS/SLK/MPV. ALSO...WITH WARM TEMPS MOVING OVER
RELATIVELY COLD SFC TEMPS/SNOWPACK AREAS OF FOG/BR WL BE POSSIBLE
IN THE DEEPER PROTECTED VALLEY LOCATIONS OF VT/NY FRIDAY INTO
SATURDAY. STRONG LLVL JET WL RESULT IN AREAS OF LLVL WS ON
FRIDAY...ESPECIALLY AT MSS WITH NORTHEAST SFC WINDS AND SW WINDS
ALOFT AT 1500 FEET AND AT MPV WITH LIGHT SFC WINDS ANTICIPATED AND
STRONG 1000 AGL WINDS OF 45 TO 50 KNTS. GUSTY SE WINDS OF 30 TO 35
KNTS WL BE POSSIBLE AT RUTLAND ON FRIDAY MORNING...WHICH WL SHIFT
TO THE SOUTHWEST AND BECM GUSTY AT MSS/SLK/PBG/BTV DURING THE
AFTN/EVENING OF FRIDAY. OTHERWISE...DRY SLOT WL RESULT IN VFR
CONDITIONS DEVELOPING FRIDAY NIGHT AND PREVAILING INTO SUNDAY.
&&
.EQUIPMENT...
DAMAGED EQUIPMENT HAS RESULTED IN AN AUDIBLE HUM ON THE MOUNT
ASCUTNEY NOAA WEATHER RADIO BROADCAST (WXM-44). OUR TECHNICIANS
ARE AWARE OF THE PROBLEM AND WILL RESOLVE THE ISSUE AS QUICKLY AS
POSSIBLE. REPAIRS MAY INVOLVE COORDINATION AND ACCESS BY
TELCO...INCLUDING PARTS ACQUISITION. THIS MAY TAKE 1-2 DAYS TO
RESOLVE. IN THE MEANTIME...WE APOLOGIZE FOR ANY DIFFICULTIES IN
HEARING THE BROADCAST FROM MOUNT ASCUTNEY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS/RJS
NEAR TERM...BANACOS
SHORT TERM...RJS
LONG TERM...LAHIFF
AVIATION...TABER
EQUIPMENT...BTV
AREA FORECAST DISCUSSION
NWS NORMAN OK
1144 AM CST WED FEB 19 2014
.DISCUSSION...
THE 18Z AVIATION DISCUSSION FOLLOWS....
&&
.AVIATION...
A WARM FRONT WILL BRING LOW CEILINGS AND PATCHES OF BR TO MUCH OF
OK AND N TX THIS AFTERNOON. CLEARING IS EXPECTED AT MOST SITES
THIS EVENING AS WINDS SWITCH TO THE S/SW AHEAD OF AN APPROACHING
COLD FRONT. THIS COLD FRONT WILL SWEEP RAPIDLY THROUGH OK/N TX
TOMORROW MORNING. BEHIND THE FRONT...EXPECT STRONG NW
WINDS...ABOUT 25-35 KT WITH GUSTS 30-40KT...PERHAPS MORE. A BRIEF
PERIOD OF CEILINGS AROUND 2500 FT WILL LIKELY FOLLOW THE FRONT AS
WELL. WINDS SHOULD DIMINISH SOMEWHAT DURING THE AFTERNOON
TOMORROW.
&&
.PREV DISCUSSION... /ISSUED 1046 AM CST WED FEB 19 2014/
UPDATE...
MADE SOME MINOR ADJUSTMENTS TO THE FORECAST THROUGH THIS EVENING.
HIGH RESOLUTION MODELS...INCLUDING THE HRRR AND NSSL
WRF...INDICATE THAT CHANCES FOR TSRA WILL REMAIN VERY SLIM OVER
MUCH OF THE REGION. THE ONE EXCEPTION LOOKS TO BE OVER FAR NORTH
CENTRAL/NORTHEAST OKLAHOMA...WHERE ELEVATED THUNDER APPEARS
PROBABLE. THUS...HAVE ADJUSTED POPS TO REFLECT LATER TIMING OF
POSSIBLE SHRA/TSRA AND INCLUDED HIGHER PROBS OVER KAY COUNTY
OKLAHOMA. OTHERWISE...THE FORECAST LOOKS TO BE IN DECENT SHAPE AND
ONLY UPDATED HOURLY TEMPS/DEWPOINTS/WINDS TO REFLECT RECENT OBS.
PREV DISCUSSION... /ISSUED 605 AM CST WED FEB 19 2014/
AVIATION...19 FEB 12Z TAF ISSUANCE...
EXPECT VFR CIGS TO PREVAIL THROUGH THE MORNING HOURS. DECENT MID-
HIGH DECK OF STRATUS WILL CONTINUE TO STREAM ACROSS THE REGION
TODAY AHEAD OF AN ADVANCING FRONTAL BOUNDARY. EASTERLY WINDS WILL
SLOWLY VEER OUT OF THE S/SE THROUGH THE DAY... WITH INCREASING
MOISTURE IN THE LOWER LEVELS. THIS MAY RESULT IN SOME LIGHT FOG
AND PERHAPS DRIZZLE ACROSS PORTIONS OF CENTRAL AND SRN OK... WITH
MVFR VIS AND CIGS. BIGGEST CONCERN FACING AVIATION THIS TAF PERIOD
ARE THE STRONG N/NW WINDS THAT WILL ARRIVE LATE IN THE PERIOD ACROSS
N/NWRN OK. EXPECT WINDS ANYWHERE FROM 20 TO 30 KTS... WITH GUSTS OF
40 TO 50 EXPECTED NEAR DAY BREAK ACROSS NWRN OK.
JTK
PREV DISCUSSION... /ISSUED 348 AM CST WED FEB 19 2014/
DISCUSSION...
PRIMARY FORECAST CONCERN REMAINS FOCUSED ON THE IMPACTS ASSOCIATED
WITH THE STOUT SFC LOW POISED TO SWING ACROSS THE SRN/CENTRAL PLAINS
TONIGHT/EARLY THU.
CURRENTLY... THE WEAK FRONT FROM TUE EVENING REMAINS STALLED SOUTH
OF THE RED RIVER... DECENT MID 50S TO NEAR 60 DEW POINTS REMAIN
POOLED ALONG THE SFC TROUGH AXIS. WITH CALM WINDS... LIGHT FOG HAS
DEVELOPED AND WILL REMAIN LIKELY THROUGH THE MORNING ALONG THE RED
RIVER VALLEY AND PORTIONS OF FAR SOUTH CENTRAL OK. 09Z SFC ANALYSIS
SHOWS TEMPS HOLDING IN THE UPPER 40S AND 50S ACROSS CENTRAL AND SRN
OK AND WRN N TX WHERE WINDS REMAIN ELEVATED. EXPECT TEMPS TO LOWER A
FEW DEGREES MORE AS WINDS LESSEN SLIGHTLY THROUGH SUNRISE.
AFTER SUNRISE... EXPECT RAPID MOISTURE RETURN TO START THIS MORNING
AS ERLY SFC WINDS VEER TO THE SE THROUGH NOON AHEAD OF THE SFC
LOW/H500 TROUGH. SPEAKING OF THE TROUGH... WV HAS IT CURRENTLY
TRAVERSING THE INTERMOUNTAIN WEST... AND IT WILL CONTINUE TO
INCREASE IN INTENSITY AS IT ADVANCES EWRD ACROSS THE ROCKIES LATER
THIS EVENING. OVERALL... PRECIP CHANCES ACROSS CENTRAL AND WRN OK
AND WRN N TX REMAIN LOW. THE 00Z ECMWF REMAINS A TAD QUICKER WITH
THE EJECTION OF THE SFC LOW TO THE E/NE THU MORNING... BUT OVERALL
TRACK REMAINS CONSISTENT WHEN COMPARED TO THE SUITE OF GUIDANCE.
BEST CHANCES FOR RAIN WILL BE E/NE OF THE FORECAST AREA ACROSS NERN
OK/SERN KS/SWRN MO... WHERE THE BETTER THETA-E ADVECTION AND
ISENTROPIC RESPONSE WILL RESIDE. ANY CHANCE OF RAIN AND/OR ISOLATED
THUNDER WILL RESIDE EAST OF I-35 TONIGHT THROUGH THURSDAY.
OF GREATER CONCERN WITH THE ARRIVAL OF THIS SFC LOW... STOUT N/NW
WINDS LATE TONIGHT THROUGH THU MORNING. QUITE THE IMPRESSIVE
PRESSURE GRADIENT ASSOCIATED WITH THE COLD FRONT AS IT SWINGS
THROUGH NWRN OK TONIGHT. 3HR PRESSURE CHANGES OF 7 TO 9 MB ARE
EXPECTED... WITH 0-1KM LAPSE RATES OF 6 TO 9 C/KM. BEST CHANCES WILL
BE AFTER MIDNIGHT THROUGH SUNRISE... WITH 40 TO 45 MPH WINDS GUSTING
50 TO 60 MPH. AREA OF GREATEST CONCERN WILL BE ALONG/NORTH OF I-40
AND ALONG/WEST OF I-35. BUFKIT PROFILES WOULD SUGGEST BL WINDS OF 50
TO 60 KTS NEAR/AT SUNRISE FOR NWRN OK. A HIGH WIND WATCH WILL REMAIN
IN EFFECT FOR THE TIME BEING FROM 1 AM TONIGHT THROUGH 1 PM THU. A
PORTION OF THIS WATCH WILL LIKELY BE UPGRADED TO A WARNING AS WE GET
CLOSER TO EVENT TIME. FOREWENT DOING THIS NOW TO AVOID CONFUSION OF
START TIME OF HIGH WINDS. HEAVILY RELATED... FIRE SPREAD POTENTIAL
WILL BE VERY HIGH TO EXTREME FOR MOST OF THE DAY THURS...ESPECIALLY
WEST OF I-35 WHERE RAPID DRYING/MIXING WILL OCCUR DUE TO THE
HIGH WINDS EARLIER IN THE DAY.
BEHIND THE FRONT... TEMPS WILL DIP NEAR NORMAL OVERNIGHT THROUGH
FRIDAY AS WINDS RELAX. TEMPS WILL THEN WARM BACK UP ONCE AGAIN
FRIDAY AS S/SW FLOW RETURNS. AS MENTIONED BY THE DAY SHIFT...SHOULD
START TO SEE A PATTERN CHANGE THROUGH THE WEEKEND AS BROAD TROUGHING
REPLACES THE QUASI-ZONAL FLOW PATTERN AHEAD OF AN APPROACHING
CANADIAN AIRMASS FOR EARLY NEXT WEEK. AT THE MOMENT... A MORE
FEBRUARY FEEL WILL BE IN THE AIR EARLY NEXT WORK WEEK AS A COLD
FRONT SETTLES ACROSS THE CENTRAL PLAINS.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 50 56 32 66 / 10 10 0 0
HOBART OK 46 56 31 64 / 0 0 0 0
WICHITA FALLS TX 55 61 34 68 / 10 0 0 0
GAGE OK 37 52 26 63 / 0 0 0 0
PONCA CITY OK 47 55 28 63 / 50 20 0 0
DURANT OK 59 64 37 66 / 10 10 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...HIGH WIND WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
OKZ004>007-009>012-014>018-021>024-033>036.
TX...NONE.
&&
$$
84/23/23
AREA FORECAST DISCUSSION
NWS NORMAN OK
1046 AM CST WED FEB 19 2014
.UPDATE...
MADE SOME MINOR ADJUSTMENTS TO THE FORECAST THROUGH THIS EVENING.
HIGH RESOLUTION MODELS...INCLUDING THE HRRR AND NSSL
WRF...INDICATE THAT CHANCES FOR TSRA WILL REMAIN VERY SLIM OVER
MUCH OF THE REGION. THE ONE EXCEPTION LOOKS TO BE OVER FAR NORTH
CENTRAL/NORTHEAST OKLAHOMA...WHERE ELEVATED THUNDER APPEARS
PROBABLE. THUS...HAVE ADJUSTED POPS TO REFLECT LATER TIMING OF
POSSIBLE SHRA/TSRA AND INCLUDED HIGHER PROBS OVER KAY COUNTY
OKLAHOMA. OTHERWISE...THE FORECAST LOOKS TO BE IN DECENT SHAPE AND
ONLY UPDATED HOURLY TEMPS/DEWPOINTS/WINDS TO REFLECT RECENT OBS.
&&
.PREV DISCUSSION... /ISSUED 605 AM CST WED FEB 19 2014/
AVIATION...19 FEB 12Z TAF ISSUANCE...
EXPECT VFR CIGS TO PREVAIL THROUGH THE MORNING HOURS. DECENT MID-
HIGH DECK OF STRATUS WILL CONTINUE TO STREAM ACROSS THE REGION
TODAY AHEAD OF AN ADVANCING FRONTAL BOUNDARY. EASTERLY WINDS WILL
SLOWLY VEER OUT OF THE S/SE THROUGH THE DAY... WITH INCREASING
MOISTURE IN THE LOWER LEVELS. THIS MAY RESULT IN SOME LIGHT FOG
AND PERHAPS DRIZZLE ACROSS PORTIONS OF CENTRAL AND SRN OK... WITH
MVFR VIS AND CIGS. BIGGEST CONCERN FACING AVIATION THIS TAF PERIOD
ARE THE STRONG N/NW WINDS THAT WILL ARRIVE LATE IN THE PERIOD ACROSS
N/NWRN OK. EXPECT WINDS ANYWHERE FROM 20 TO 30 KTS... WITH GUSTS OF
40 TO 50 EXPECTED NEAR DAY BREAK ACROSS NWRN OK.
JTK
PREV DISCUSSION... /ISSUED 348 AM CST WED FEB 19 2014/
DISCUSSION...
PRIMARY FORECAST CONCERN REMAINS FOCUSED ON THE IMPACTS ASSOCIATED
WITH THE STOUT SFC LOW POISED TO SWING ACROSS THE SRN/CENTRAL PLAINS
TONIGHT/EARLY THU.
CURRENTLY... THE WEAK FRONT FROM TUE EVENING REMAINS STALLED SOUTH
OF THE RED RIVER... DECENT MID 50S TO NEAR 60 DEW POINTS REMAIN
POOLED ALONG THE SFC TROUGH AXIS. WITH CALM WINDS... LIGHT FOG HAS
DEVELOPED AND WILL REMAIN LIKELY THROUGH THE MORNING ALONG THE RED
RIVER VALLEY AND PORTIONS OF FAR SOUTH CENTRAL OK. 09Z SFC ANALYSIS
SHOWS TEMPS HOLDING IN THE UPPER 40S AND 50S ACROSS CENTRAL AND SRN
OK AND WRN N TX WHERE WINDS REMAIN ELEVATED. EXPECT TEMPS TO LOWER A
FEW DEGREES MORE AS WINDS LESSEN SLIGHTLY THROUGH SUNRISE.
AFTER SUNRISE... EXPECT RAPID MOISTURE RETURN TO START THIS MORNING
AS ERLY SFC WINDS VEER TO THE SE THROUGH NOON AHEAD OF THE SFC
LOW/H500 TROUGH. SPEAKING OF THE TROUGH... WV HAS IT CURRENTLY
TRAVERSING THE INTERMOUNTAIN WEST... AND IT WILL CONTINUE TO
INCREASE IN INTENSITY AS IT ADVANCES EWRD ACROSS THE ROCKIES LATER
THIS EVENING. OVERALL... PRECIP CHANCES ACROSS CENTRAL AND WRN OK
AND WRN N TX REMAIN LOW. THE 00Z ECMWF REMAINS A TAD QUICKER WITH
THE EJECTION OF THE SFC LOW TO THE E/NE THU MORNING... BUT OVERALL
TRACK REMAINS CONSISTENT WHEN COMPARED TO THE SUITE OF GUIDANCE.
BEST CHANCES FOR RAIN WILL BE E/NE OF THE FORECAST AREA ACROSS NERN
OK/SERN KS/SWRN MO... WHERE THE BETTER THETA-E ADVECTION AND
ISENTROPIC RESPONSE WILL RESIDE. ANY CHANCE OF RAIN AND/OR ISOLATED
THUNDER WILL RESIDE EAST OF I-35 TONIGHT THROUGH THURSDAY.
OF GREATER CONCERN WITH THE ARRIVAL OF THIS SFC LOW... STOUT N/NW
WINDS LATE TONIGHT THROUGH THU MORNING. QUITE THE IMPRESSIVE
PRESSURE GRADIENT ASSOCIATED WITH THE COLD FRONT AS IT SWINGS
THROUGH NWRN OK TONIGHT. 3HR PRESSURE CHANGES OF 7 TO 9 MB ARE
EXPECTED... WITH 0-1KM LAPSE RATES OF 6 TO 9 C/KM. BEST CHANCES WILL
BE AFTER MIDNIGHT THROUGH SUNRISE... WITH 40 TO 45 MPH WINDS GUSTING
50 TO 60 MPH. AREA OF GREATEST CONCERN WILL BE ALONG/NORTH OF I-40
AND ALONG/WEST OF I-35. BUFKIT PROFILES WOULD SUGGEST BL WINDS OF 50
TO 60 KTS NEAR/AT SUNRISE FOR NWRN OK. A HIGH WIND WATCH WILL REMAIN
IN EFFECT FOR THE TIME BEING FROM 1 AM TONIGHT THROUGH 1 PM THU. A
PORTION OF THIS WATCH WILL LIKELY BE UPGRADED TO A WARNING AS WE GET
CLOSER TO EVENT TIME. FOREWENT DOING THIS NOW TO AVOID CONFUSION OF
START TIME OF HIGH WINDS. HEAVILY RELATED... FIRE SPREAD POTENTIAL
WILL BE VERY HIGH TO EXTREME FOR MOST OF THE DAY THURS...ESPECIALLY
WEST OF I-35 WHERE RAPID DRYING/MIXING WILL OCCUR DUE TO THE
HIGH WINDS EARLIER IN THE DAY.
BEHIND THE FRONT... TEMPS WILL DIP NEAR NORMAL OVERNIGHT THROUGH
FRIDAY AS WINDS RELAX. TEMPS WILL THEN WARM BACK UP ONCE AGAIN
FRIDAY AS S/SW FLOW RETURNS. AS MENTIONED BY THE DAY SHIFT...SHOULD
START TO SEE A PATTERN CHANGE THROUGH THE WEEKEND AS BROAD TROUGHING
REPLACES THE QUASI-ZONAL FLOW PATTERN AHEAD OF AN APPROACHING
CANADIAN AIRMASS FOR EARLY NEXT WEEK. AT THE MOMENT... A MORE
FEBRUARY FEEL WILL BE IN THE AIR EARLY NEXT WORK WEEK AS A COLD
FRONT SETTLES ACROSS THE CENTRAL PLAINS.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 69 50 56 32 / 10 10 10 0
HOBART OK 67 46 56 31 / 0 0 0 0
WICHITA FALLS TX 74 55 61 34 / 0 10 0 0
GAGE OK 64 37 52 26 / 0 0 0 0
PONCA CITY OK 62 47 55 28 / 20 50 20 0
DURANT OK 69 59 64 37 / 20 10 10 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...HIGH WIND WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR
OKZ004>007-009>012-014>018-021>024-033>036.
TX...NONE.
&&
$$
84/23
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1204 PM CST WED FEB 19 2014
.AVIATION...
THE MVFR STRATUS LAYER AT KCDS HAS BEEN QUITE PERSISTENT...WITH
EACH HOURLY RUN OF THE RAP CONTINUING TO DELAY CLEARING UNTIL THE
NEXT HOUR. VIEWING OF THE STRATUS LAYER VIA SATELLITE DIFFERENCE
CHANNELS HAS BEEN HAMPERED BY THE THICKER CLOUD DECK BLOCKING FROM
ALOFT. ALSO...IT HAS BECOME LESS OBVIOUS IF SURFACE SOUTHWEST WIND
FLOW WILL BE ABLE TO DEVELOP ANYTIME THIS AFTERNOON AT KCDS. FOR
THIS FORECAST WE WILL SIDE WITH THE RAP MAINTAINING AN EAST OR
SOUTHEAST LOW LEVEL COMPONENT THROUGH THE AFTERNOON...THOUGH BREAK
OUT THE MVFR CLOUD LAYER BY 19Z. THE WEST TO SOUTHWEST COMPONENT
AT KLBB ALSO IS A BIT DELAYED WITH ONLY VERY WEAK SURFACE PRESSURE
FALLS CURRENTLY NEAR THE NEW MEXICO BORDER...BUT MORE BROAD
PRESSURE FALLS EXPECTED TO EXPAND THROUGH THE AREA THIS AFTERNOON
WHICH SHOULD GENERATE MORE WESTERLY COMPONENT BY MID TO LATE IN
THE AFTERNOON. THE NEXT EVENT WILL BE PASSAGE OF A VIGOROUS COLD
FRONT LATE IN THE NIGHT...NOT MUCH TO DIFFER WITH TIMING OF THE
FRONT. SPEEDS SHOULD INCREASE AROUND DAYBREAK THURSDAY AS WINDS
VEER SLIGHTLY MORE TO THE NORTH. ADDED A MENTION OF A MINOR
VISIBILITY REDUCTION FOR BLOWING DUST AT KLBB AFTER DAYBREAK
THURSDAY DUE TO FAVORABLE COMPOENENT...SPEEDS...AND TIME OF YEAR.
RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 516 AM CST WED FEB 19 2014/
AVIATION...
VFR TO CONTINUE NEXT 24 HOURS. PRESSURE GRADIENT WILL INCREASE
THIS EVENING AS SURFACE TROUGH ACROSS ERN NM BEGINS TO PUSH
EASTWARD. STRONG COLD FRONT WILL BRING WINDY CONDITIONS TO BOTH
TERMINALS EARLY THURSDAY MORNING.
PREV DISCUSSION... /ISSUED 240 AM CST WED FEB 19 2014/
SHORT TERM...
THROUGH 21/00Z. ZONAL FLOW ACROSS THE REGION WILL BECOME MORE
SOUTHWESTERLY AS TROUGH AMPLIFIES ACROSS THE ROCKIES TODAY AND
TONIGHT. PRIMARY CONCERN WILL BE WIND SPEEDS AND SOME LIMITED
POTENTIAL FOR FIRE WEATHER THIS AFTERNOON BEFORE A STRONG COLD FRONT
ENTERS THE PICTURE EARLY THURSDAY MORNING WITH YET MORE WIND.
PRIMARY WIND DRIVER TODAY OUT EAST WILL BE THE SURFACE PRESSURE
GRADIENT AS INVERSION ALOFT FROM ABOUT H9 TO H8 LIMITS POTENTIAL
ACROSS THE EASTERN ROLLING PLAINS. FURTHER WEST...A NICE ADIABATIC
LAPSE RATE IS PROGGED UP TO ABOUT 750MB AND THIS SHOULD ALLOW
EFFICIENT MISSING LATER THIS AFTERNOON WITH SPEEDS UP IN THE 15-20
MPH RANGE. SEE FIRE WEATHER SECTION BELOW. THESE WINDS WILL
CONTINUE TO INCREASE TO 20-25 MPH DURING THE EVENING AS SURFACE LOW
KICKS EASTWARD IN RESPONSE TO AFOREMENTIONED DEEPENING UPPER LEVEL
TROUGH. THEN...A STRONGLY FORCED COLD FRONT SHOULD ENTER THE REGION
AND POSSIBLY CLEAR THE ENTIRE CWFA BY 12Z THURSDAY MORNING. WINDS
BEHIND THIS FRONT LOOK TO BE QUITE GUSTY AND MAY MEET ADVISORY
CRITERIA.
LONG TERM...
THE UA TROUGH RESPONSIBLE FOR THE RATHER BREEZY CONDITIONS
ANTICIPATED FOR LATE TONIGHT INTO TOMORROW...WILL BE EAST OF THE
SOUTHERN PLAINS BY TOMORROW EVENING...AND THUS SLIGHT W-NW FLOW
ALOFT WILL SETTLE BACK TO SEMI-ZONAL FLOW BY FRI. THE EXTENDED
FORECAST WILL BE PUNCTUATED BY SEVERAL COLD FRONTAL PASSAGES THAT
ARE ASSOCIATED WITH A SERIES OF DISTURBANCES PASSING TO OUR NORTH.
THE FIRST OF THESE COLD FRONTS WILL OCCUR ON SAT...AND IS EXHIBITED
TO BE RELATIVELY WEAK AS 850 MB TEMPS REMAIN WELL ABOVE 0 DEGREES C
WITH RELATIVELY LIGHT WIND SPEEDS. LONG TERM SOLUTIONS SHOW THIS
FRONT TO WASH OUT OVER THE CWA HENCE WINDS WILL RETURN TO A S-SE
COMPONENT BY THE EVENING-OVERNIGHT HOURS. THIS APPEARS TO BE
SHORT-LIVED AS YET ANOTHER FRONT IMPINGES ON THE REGION ON SUNDAY.
WINDS ARE A TAD BIT BREEZIER BEHIND THIS COLD FRONTAL PASSAGE /10-15
MPH/ IN ADDITION TO BEING COLDER AS 850 MB TEMPS DROP TO A RANGE OF
2-14 DEGREES C DURING THE DAY. WILL THEREFORE SEE HIGHS DROP FROM
MAINLY THE 60S ON SAT TO THE 50S /WITH A FEW 60S/ SUN. QUITE A BIT
OF DRY AIR IN THE LOW-MID LEVELS WOULD NEED TO BE OVERCOME IN ORDER
FOR PRECIP TO DEVELOP...THUS LACK OF QPF SIGNALS APPEAR VALID.
EARLY NEXT WEEK...AMPLIFIED UA RIDGING ACROSS THE WRN CONUS WILL
PROMOTE A SLIGHT W-NW FLOW ALOFT ACROSS THE SOUTHERN PLAINS. LONG
TERM SOLUTIONS HINT AT THIS FLOW ALOFT POSSIBLY BEING VEERED JUST
ENOUGH TO ALLOW FOR A COLDER AIR INTRUSION IN ASSOCIATED WITH
ANOTHER BREEZY FROPA ON TUE...AS 850 MB TEMPS DROP TO SLIGHTLY BELOW
0 DEGREES C /SUGGESTIVE OF HIGHS ONLY IN THE 40S/. THOUGH...THE MUCH
COLDER AIR IS PROJECTED TO REMAIN ENTRENCHED ACROSS THE GREAT LAKES
REGION AND THE NERN CONUS. FURTHERMORE...PROGGED SOUNDINGS DISPLAYED
MOISTENING LOW LEVELS TUE AS PWATS MARGINALLY INCREASE TO AOA 0.50
INCHES /ESPECIALLY OFF THE CAPROCK/. HOWEVER...MID LEVELS ARE RATHER
DRY AND IT IS NO WONDER QPF VALUES ARE SHOWN TO BE RATHER LIGHT.
WILL NOT INCREASE POPS BEYOND 5 PERCENT POPS ON TUE ATTM.
ALTHOUGH THE EXTENDED FORECAST IS PLAGUED WITH FRONTAL
PASSAGES...THERE WILL BE A FEW DAYS WHERE NEARBY SFC LEE TROUGHING
ENCOURAGES MODEST SWRLY BREEZES AND THUS WARMER TEMPS /LOWER TO UPPER
60S/...WHICH WILL OCCUR ON FRI AND MON.
FIRE WEATHER...
DAY 1...
PRESENT INDICATIONS SUGGEST THAT WHILE WE WILL HAVE PERIODS OF QUITE
DRY CONDITIONS AND WINDY CONDITIONS...THE OVERLAP OF THESE TWO
PARAMETERS APPEARS TO BE MINIMAL. GIVEN THE REPORTED FIRES OF THE
PAST COUPLE OF DAYS...THERE IS LITTLE DOUBT THAT FUELS ARE QUITE
VOLATILE. GIVEN THE WIND SPEEDS IN THE 15-20 MPH RANGE THIS
AFTERNOON ALONG WITH MIN RH VALUES IN THE 10-15 PC RANGE...WILL
ELECT TO ISSUE RFD GENERALLY WEST OF THE CAPROCK ESCARPMENT.
ADJACENT AREAS OF THE ROLLING PLAINS MAY ALSO BE ELEVATED THOUGH
WIND SPEEDS ARE EXPECTED TO BE A BIT LIGHTER OUT EAST. FOR THIS
AFTERNOON...MOST FAVORABLE FIRE WX CONDITIONS LOOK TO BE ACROSS THE
SOUTHWESTERN SOUTH PLAINS. VERY LITTLE IN THE WAY OF OVERNIGHT
RECOVERY IS EXPECTED WITH RH VALUES REMAINING UNDER 30 PCT.
DAY2...
ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE MAINLY EAST OF THE
I-27 CORRIDOR DURING THE MORNING HOURS AS GUSTY WINDS PREVAIL BEHIND
A FAST MOVING COLD FRONT. THE BEST DRYING...HOWEVER...APPEARS TO
OCCUR AFTER THE WINDS BEGIN TO SUBSIDE IN THE AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 72 36 53 22 64 / 0 0 0 0 0
TULIA 71 39 52 25 63 / 0 0 0 0 0
PLAINVIEW 75 41 52 26 65 / 0 0 0 0 0
LEVELLAND 79 43 56 28 69 / 0 0 0 0 0
LUBBOCK 79 43 55 29 67 / 0 0 0 0 0
DENVER CITY 80 41 58 32 69 / 0 0 0 0 0
BROWNFIELD 82 43 57 29 69 / 0 0 0 0 0
CHILDRESS 72 45 56 30 67 / 0 0 0 0 0
SPUR 81 47 57 29 68 / 0 0 0 0 0
ASPERMONT 83 48 57 30 68 / 0 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1006 AM CST WED FEB 19 2014
.UPDATE...
ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 10AM AND REMOVED THE
ADVISORY FROM THE ZONES. A COUPLE LOCATIONS WERE STILL AT ONE
QUARTER MILE...HOWEVER VISIBILITIES WERE GENERALLY ON THE INCREASE.
THE SHORT TERM FORECAST WILL ADDRESS THE LOCALIZED LOWER VISIBILITIES
FOR THE NEXT HOUR. OTHERWISE THE ONGOING FORECAST IS ON TRACK AND
NO MAJOR CHANGES NEEDED AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 613 AM CST WED FEB 19 2014/
UPDATE...
WE HAVE UPDATED THE FORECAST TO ISSUE A DENSE FOG ADVISORY FOR
AREAS GENERALLY ALONG AND WEST OF A LLANO TO NEW BRAUNFELS TO SAN
ANTONIO TO PLEASANTON LINE. LIGHT WINDS AND PLENTY OF LOW LEVEL
MOISTURE HAS LED TO PATCHY...DENSE FOG ACROSS ROUGHLY THE WESTERN
2/3 OF SOUTH CENTRAL TEXAS THIS MORNING. IMPROVING CONDITIONS ARE
EXPECTED AFTER 10 AM AS WINDS AND TEMPERATURES BEGIN TO INCREASE.
PREV DISCUSSION... /ISSUED 354 AM CST WED FEB 19 2014/
SHORT TERM (TODAY THROUGH THURSDAY)...
SURFACE OBSERVATIONS AND SATELLITE IMAGERY SHOW FOG AND LOW CLOUDS
ARE CURRENTLY IN PLACE ACROSS SOUTH CENTRAL TEXAS. BASED ON RECENT
TRENDS AND THE LATEST HI-RES RUC MODEL...WE HAVE INCLUDED A
MENTION OF PATCHY...DENSE FOG ACROSS THE HILL COUNTRY AND SOUTHERN
EDWARDS PLATEAU. THE FOG IS EXPECTED TO DECREASE BY MID-MORNING AS
SOUTHERLY WINDS AND DAYTIME HEATING COMMENCE. AFTERNOON
TEMPERATURES WILL WARM TO ABOVE NORMAL LEVELS TODAY... WITH HIGHS
RANGING FROM THE UPPER 80S ALONG THE RIO GRANDE TO UPPER 70S ALONG
THE HIGHWAY 77 CORRIDOR. MOIST CONDITIONS REMAIN IN PLACE TONIGHT
AND WE/LL CONTINUE TO MENTION FOG AND DRIZZLE ACROSS MOST AREAS. A
PACIFIC COLD FRONT WILL MOVE THROUGH THE REGION ON THURSDAY. IN
ADVANCE OF THE FRONT...CAN/T RULE OUT SOME LIGHT MORNING SHOWERS
ALONG AND EAST OF THE I-35 CORRIDOR. WE/LL ALSO CONTINUE TO
MENTION A SLIGHT CHANCE FOR AFTERNOON THUNDERSTORMS EAST OF I-35
AS THE COLD FRONT WILL BE ACROSS THIS REGION DURING PEAK HEATING.
THE COLD FRONT WILL ALSO BRING AN INCREASE IN FIRE WEATHER
CONCERNS FOR AREAS ALONG AND WEST OF I-35. PLEASE SEE THE BELOW
FIRE WEATHER SECTION FOR MORE INFORMATION.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
WINDS WILL DECREASE THURSDAY NIGHT AS SKIES REMAIN MOSTLY CLEAR.
THIS ALONG WITH DRY AIR WILL ALLOW TEMPERATURES TO DROP INTO THE
LOWER 30S ACROSS THE HILL COUNTRY TO THE MID 40S COASTAL PLAINS.
SOUTHERLY FLOW IN THE LOW-LEVELS RESUMES ON FRIDAY AS ZONAL FLOW
ALOFT PERSISTS. A WARMING TREND IS EXPECTED SATURDAY AS THE LATEST
MEDIUM RANGE MODELS SHOW A COLD FRONT REMAINING NORTH OF THE
REGION. THERE IS SOME DISAGREEMENT AMONG THE MEDIUM RANGE MODELS
WITH REGARDS TO THE SOUTHWARD PROGRESS OF THE COLD FRONT ON
SUNDAY. FOR NOW...WILL SHOW SOME SLIGHTLY COOLER TEMPERATURES
NORTH OF I-10...WITH LITTLE CHANGE ELSEWHERE. THE FLOW ALOFT OVER
THE WESTERN U.S. WILL AMPLIFY EARLY NEXT WEEK...BUT DOES NOT
CHANGE SIGNIFICANTLY ACROSS THE SOUTHERN PLAINS. THIS PATTERN DOES
FAVOR PERIODIC COLD FRONTS MOVING INTO THE REGION AND WE/LL SHOW
SOME NEAR TO BELOW NORMAL TEMPERATURES ON TUESDAY. SOME LIGHT
SHOWERS ARE POSSIBLE EARLY NEXT WEEK...BUT OVERALL AMOUNTS AND
PRECIPITATION CHANCES WILL REMAIN LOW.
FIRE WEATHER...
CRITICAL TO NEAR CRITICAL FIRE WEATHER CONDITIONS ARE LIKELY FOR
AREAS MAINLY ALONG AND WEST OF THE I-35 CORRIDOR THURSDAY
AFTERNOON IN THE WAKE OF A PACIFIC COLD FRONT. RELATIVE HUMIDITIES
WILL DROP INTO THE TEENS WITH NORTH WINDS OF 15 TO 25 MPH AND
GUSTY FOLLOWING THE FRONTAL PASSAGE. ELEVATED FIRE WEATHER
CONDITIONS ARE POSSIBLE FRIDAY AFTERNOON MAINLY ALONG AND WEST OF
THE I-35 CORRIDOR AS RELATIVE HUMIDITIES AGAIN FALL INTO THE
TEENS WITH SOUTHERLY WINDS OF 10 TO 15 MPH.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 81 64 81 43 72 / - - 20 - -
AUSTIN BERGSTROM INTL AIRPORT 79 61 81 36 71 / - - 20 - -
NEW BRAUNFELS MUNI AIRPORT 80 61 83 39 73 / - - 20 - -
BURNET MUNI AIRPORT 78 60 76 37 69 / - - 20 - -
DEL RIO INTL AIRPORT 88 58 86 43 74 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 79 62 78 38 69 / - - 20 - -
HONDO MUNI AIRPORT 85 59 86 40 75 / - - 10 0 -
SAN MARCOS MUNI AIRPORT 79 62 81 39 71 / - - 20 - -
LA GRANGE - FAYETTE REGIONAL 78 64 79 42 69 / - 10 20 10 -
SAN ANTONIO INTL AIRPORT 82 63 85 44 74 / - - 10 - -
STINSON MUNI AIRPORT 82 62 86 43 73 / - - 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY EVENING
FOR THE FOLLOWING COUNTIES: BANDERA...BASTROP...BEXAR...BLANCO...
BURNET...CALDWELL...COMAL...DIMMIT...EDWARDS...FRIO...GILLESPIE...
GUADALUPE...HAYS...KENDALL...KERR...KINNEY...LLANO...MAVERICK...
MEDINA...REAL...TRAVIS...UVALDE...VAL VERDE...WILLIAMSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...01
PUBLIC SERVICE/DATA COLLECTION...32
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1244 PM EST WED FEB 19 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE AREA THIS AFTERNOON AND INTO
THURSDAY. A STRONG COLD FRONT WILL MOVE THROUGH THE AREA EARLY
FRIDAY WITH HEAVY SHOWERS...GUSTY WINDS...AND EVEN A FEW
THUNDERSTORMS ONCE AGAIN. SUCCESSIVELY COLDER TEMPERATURES ARE
EXPECTED FOR THE WEEKEND INTO NEXT WEEK...WITH AN INCREASING
THREAT FOR WINTER PRECIPITATION NEXT WEEK AND MUCH BELOW NORMAL
TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM EST WEDNESDAY...
A WEAK SURFACE FRONT IS APPROACHING WESTERN SLOPES OF SE WV EARLY
THIS AFTERNOON. THIS IS BEING PICKED UP BY HRRR THAN ANY OTHER
MODEL. I HAVE INCREASED POPS ALONG WESTERN SLOPES TO 30-40
PERCENT...THEN DECREASE CHANCES AND AREAL COVERAGE THROUGH THE
REMAINDER OF THE AFTERNOON. WINDS MAY ALSO BE BREEZY AND GUSTY
THIS AFTERNOON WITH PRESSURE RISES BEHIND THE FRONT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 400 AM EST WEDNESDAY...
EASTERLY COMPONENT STRENGTHENING IN RESPONSE TO AN AMPLIFYING
UPPER PATTERN...WILL KEEP TEMPS COOLER THAN WEDNESDAY AT MANY
LOCATIONS...ESPECIALLY ALONG THE BLUE RIDGE. ALSO PATCHY
DRIZZLE/SHOWERS WILL DEVELOP WITH THE UPSLOPE FLOW WELL AHEAD OF
THE FRONT THURSDAY AFTERNOON. STIFF BREEZE AND CLOUDS THURSDAY
NIGHT MAY KEEP SOME OF THE WARMER SPOTS NEAR THE MID 50S ALL
NIGHT. SHOWERS ASSOCIATED WITH THE FRONT SHOULD BREAK OUT AFTER
MIDNIGHT...WITH HEAVY RAIN AT TIMES THROUGH THE BLF/JFZ CORRIDOR.
MODELS GIVING A WIDESPREAD HALF INCH OF RAIN ACROSS THE
REGION...BUT THERE WILL BE SOME UPSLOPE ENHANCEMENT ALONG THE BLUE
RIDGE. THINKING THAT MOST OF THE SNOWCOVER WILL BE GONE AT THIS
POINT TO PRECLUDE WATER PROBLEMS. NOT MUCH INSTABILITY BUT THERE
REMAINS A SLT CHC OF THUNDER MAINLY ACROSS EXTREME SW VA AND THEN
THE VA/NC PIEDMONT IN THE AFTERNOON. SPC HAS PUT ROUGHLY THE AREA
EAST OF THE BLUE RIDGE INTO A SLT RISK ANTICIPATING A HIGH SHEAR
LOW CAPE SETUP THURSDAY LATE MORNING. QUITE POSSIBLE THAT THE
STRONGEST CELLS DEVELOP SOUTH OF OUR REGION...WHERE CONDITIONS ARE
MORE FAVORABLE...THEN RACE NNE ALONG THE BOUNDARY OR JUST AHEAD OF
IT INTO THE SOUTHSIDE. AIRMASS BEHIND THE FRONT IS COOLER...BUT
NOT WHAT ONE WOULD EXPECT IN FEBRUARY...AS BREEZY DOWNSLOPING
WINDS WILL PUSH MAX T ACROSS 60F AGAIN AT THE WARMEST SITES
SATURDAY.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 PM EST MONDAY...
HIGH PRESSURE WILL BUILD INTO THE REGION FRIDAY NIGHT IN THE WAKE OF
A DEPARTING COLD FRONT. DESPITE THE FRONTAL PASSAGE...AIR MOVING IN
FROM THE WEST WILL ONLY BE SLIGHTLY COOLER...AND EXPECT FRIDAY NIGHT
LOWS TO HOLD IN THE UPPER 20S TO THE LOW 30S...WHILE SATURDAY
AFTERNOON HIGHS REACH INTO THE 50S FOR MOST LOCATIONS...PERHAPS
TOUCHING 60 IN SOUTHSIDE VIRGINIA.
TEMPERATURES REMAIN RELATIVELY MILD SATURDAY NIGHT AS WINDS SHIFT
SOUTHWESTERLY AGAIN AHEAD OF OUR NEXT COLD FRONT...THIS ONE A
CLIPPER APPROACHING FROM THE NORTHWEST. AS WE HAVE SEEN SEVERAL
TIMES THIS WINTER...THIS CLIPPER WILL BRING UPSLOPE SNOW SHOWERS TO
THE MOUNTAINS...ESPECIALLY SOUTHEAST WEST VIRGINIA...WITH UP TO AN
INCH OF NEW SNOW POSSIBLY IN WESTERN GREENBRIER COUNTY. SNOW SHOWERS
WILL TAPER OFF SUNDAY MORNING AS CANADIAN HIGH PRESSURE BUILDS IN
FROM THE WEST TO CONTROL THE WEATHER PATTERN THROUGH MONDAY EVENING.
TEMPERATURES FOR SUNDAY NIGHT THROUGH MONDAY NIGHT WILL BE NEAR
SEASONAL NORMALS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 633 AM EST WEDNESDAY...
A WEAK COLD FRONT WILL MAKE ITS WAY ACROSS THE FORECAST AREA THIS
AFTERNOON. THERE ARE A FEW SHOWERS COMING ACROSS EASTERN KENTUCKY
THAT COULD IMPACT LEWISBURG (LWB) TO BLUEFIELD (BLF) TO MOUNT
AIRY (MWK) AND POINTS SOUTHWEST THROUGH THE AFTERNOON. VAD WIND
PROFILES HAS WEST WINDS ALOFT...THEREFORE SHOWERS MAY NOT SURVIVE
MOVING EAST ACROSS THE MOUNTAIN EMPIRE. THIS WEST WIND AND
MOISTURE WILL LIKLEY BRING IFR-MVFR CIELINGS ALONG WESTERN SLOPES
INTO THIS EVENING. PRESSURE RISES BEHIND THE FRONT WILL ALSO BRING
BREEZY AND GUSTY CONDITIONS TO THE AREA INTO EARLY THIS
EVENING...THEN DECOUPLE AS HIGH PRESSURE TRACKS OVER THE REGION.
HIGH PRESSURE AND CLEAR SKIES WILL WIN OUT THROUGH MOST OF THE
OVERNIGHT FOR ALL TAF SITES. TOWARDS SUNRISE...A WARM FRONT WILL
OVERRUN LINGERING SURFACE RIDGE TO INCREASE CLOUDS FROM THE
SOUTHWEST TO NORTHEAST. THROUGH THE DAY...CEILING COULD LOWER TO
MVFR ALONG AND EAST OF THE BLUE RIDGE. BY THURSDAY EVENING...LIGHT
RAIN/DRIZZLE/FOG LIKELY TO FORM AND REMAIN IN THE AREA UNTIL A
STRONGER FRONT PUSHES OVER THE REGION FRIDAY MORNING. EASTERLY
DOWNSLOPE FLOW WILL KEEP THE WEST (BLF-LWB) DRY WITH CIELINGS
REMAINING VFR UNTIL THE STRONGER FRONT APPORAHCES THE AREA.
A STRONG COLD FRONT WILL CROSS THE REGION LATE THURSDAY NIGHT INTO
EARLY FRIDAY MORNING. EXPECT A LINE OF GUSTY SHOWERS TO ACCOMPANY
THE FRONT...AND WINDS TO SHIFT NORTHWEST BEHIND IT BY MIDDAY FRIDAY.
A TREND TOWARD COLDER TEMPERATURES...BUT A SUSTAINED NORTHWEST
FLOW AND MAINLY VFR CONDITIONS WILL CONTINUE THROUGH THE WEEKEND.
HIGH PRESSURE...DRY AIR AND UNFAVORABLE WIND DIRECTION SHOULD
PRECLUDE UPSLOPE SNOW SHOWERS AT LWB AT THE END OF THE WEEKEND.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...RAB/RCS
SHORT TERM...KM
LONG TERM...NF
AVIATION...RCS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
328 PM CST WED FEB 19 2014
.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 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1152 AM CST WED FEB 19 2014
THE 19.12Z NAM APPEARS TO BE AN OUTLIER WHEN COMPARED TO THE OTHER
19.12Z MODELS. DUE THIS...DID NOT CONSIDER THE NAM WHEN MAKING THE
AVIATION FORECAST. EVEN WITH THIS MODEL OUT OF THE MIX...THERE
CONTINUES TO BE SOME QUESTIONS ON HOW FAR WEST WILL WARM AIR WILL
GET LATE THURSDAY MORNING AND AFTERNOON. THE GFS...GEM...AND
UKMET SUGGEST THAT THE WARM AIR WILL ADVANCE AS FAR WEST AS THE
MISSISSIPPI RIVER. THIS WILL AFFECT BOTH THE PRECIPITATION TYPE
AND SNOW AMOUNTS AT LA CROSSE. BUFKIT SOUNDINGS SUGGEST THAT THE
PRECIPITATION WILL START OUT AS SNOW IN LA CROSSE AROUND 20.10Z
AND THEN TRANSITION OVER TO RAIN BY 20.16Z. THERE WAS EVEN SOME
HINTS IN THE RAP THAT THERE MAY BE EVEN SOME FREEZING RAIN
OVERNIGHT. SINCE THIS WAS THE ONLY ONE SHOWING IT AT THAT
TIME...JUST WENT WITH SNOW LATE TONIGHT. MEANWHILE AT KRST THE
PRECIPITATION LOOKS LIKE IT WILL STAY MAINLY SNOW...BUT THERE MAY
BE A BRIEF PERIOD OF SLEET. SNOW TOTALS THROUGH NOON WILL BE
AROUND AN INCH...AND THEN A RAPID INCREASE DURING THE AFTERNOON
AND EARLY EVENING. HOURLY SNOW RATES OF 1 TO 2 INCHES AN HOUR
DURING THE LATE AFTERNOON AND EARLY EVENING. TOTAL SNOWFALL
RANGING FROM 6 TO 10 INCHES.
CEILINGS AND VISIBILITIES AT BOTH TAF SITES WILL QUICKLY BECOME
IFR ONCE THE PRECIPITATION BEGINS.
&&
.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.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1154 AM CST WED FEB 19 2014
.SHORT TERM...(TODAY THROUGH THROUGH THURSDAY)
ISSUED AT 414 AM CST WED FEB 19 2014
INCOMING MAJOR WINTER STORM IS MAIN FORECAST FOCUS.
CURRENT WATER VAPOR ANALYSIS HAS A TROUGH OF LOW PRESSURE PUSHING
EAST OF THE REGION. RADAR WAS SHOWING SOME RETURNS ACROSS SOUTHEAST
WI WITH THIS FEATURE. AT THE SURFACE...HIGH PRESSURE WAS MOVING INTO
THE REGION FROM THE PLAINS. UNDER MOSTLY CLEAR SKIES...TEMPERATURES
ACROSS THE AREA WERE IN THE 20S. OF BIGGER CONCERN ON WATER VAPOR
WAS A DEEPENING TROUGH COMING ONSHORE OFF THE WEST COAST. THIS WAS
PRODUCING SURFACE CYCLOGENESIS OVER THE INTERMOUNTAIN WEST. THIS
CYCLONE WILL BE OUR MAJOR WINTER STORM HEADING INTO
THURSDAY/THURSDAY NIGHT.
PRETTY DECENT DAY ON TAP FOR TODAY AS HIGH PRESSURE DRIFTS ACROSS
THE REGION AND WITH WEAK WARM AIR ADVECTION KICKING IN LATER THIS
AFTERNOON. SKIES EXPECTED TO START OFF MOSTLY SUNNY...THEN WILL SEE
AN INCREASE IN HIGH/MID CLOUDS THROUGH THE AFTERNOON IN RESPONSE TO
THE WARM AIR ADVECTION. OTHERWISE...LOOK FOR HIGHS TODAY IN THE MID-
UPPER 30S.
TONIGHT GETS A BIT MESSY AS A WEAKER LEAD/MID-LEVEL WAVE GET EJECTED
TOWARD THE UPPER MISSISSIPPI RIVER REGION AFTER MIDNIGHT AHEAD OF
THE MAIN TROUGH/STRONGER SURFACE CYCLOGENESIS OVER THE SOUTHERN
PLAINS. MODERATE ISENTROPIC UPGLIDE AND WEAK 700-300MB PV-ADVECTION
WILL BE ENOUGH TO BRING IN A WINTRY MIX OF SNOW/SLEET AND POSSIBLY
POCKETS OF FREEZING RAIN TOWARD MORNING...THEN LASTING INTO MID/LATE
MORNING. THIS IS OF COURSE BEFORE THE MAIN LOW THAT WILL BE
DEEPENING OVER THE CENTRAL PLAINS. THEN LOOK FOR THE MAIN LOW TO
DEEPEN QUICKLY AND MOVE NORTHEAST INTO NORTHWEST IL BY 18Z AND THEN
INTO SOUTHEAST WI BY LATE AFTERNOON. STRONG MID-LEVEL FRONTOGENESIS
NORTHWEST OF THE LOW WILL RAPIDLY COOL THE COLUMN BY LATER IN THE
MORNING/EARLY AFTERNOON FOR ALL SNOW ACROSS ALL BUT PORTIONS OF
NORTHEAST IA INTO FAR SOUTHWEST WI WHERE A WINTRY MIX MAY LINGER A
BIT LONGER INTO THURSDAY AFTERNOON. STRONGER FRONTOGENESIS AND
SLANTWISE CONVECTION/POCKETS OF THUNDERSNOW NORTHWEST OF THIS LOW
TRACK WILL LEAD TO RAPID SNOW ACCUMULATIONS ACROSS NORTHEAST
IA/SOUTHEAST MN...INTO SOUTHWEST/CENTRAL WI. CURRENT THINKING IS THE
HEAVIEST SNOWFALL AXIS WILL EXTEND FROM MEDFORD WI THROUGH WINONA MN
TO CHARLES CITY IA...WHERE 8-12 INCHES LOOKS LIKELY. LOOK FOR WEST
TO NORTHWEST WINDS TO KICK IN ON THE BACKSIDE OF THE LOW TOWARD NOON
AND THEN GET VERY STRONG BY LATE IN THE AFTERNOON GUSTING IN THE 40-
50 MPH RANGE WEST OF THE MISSISSIPPI RIVER DURING THE HEAVY SNOW
PERIOD. WHITEOUT CONDITIONS WILL LIKELY BE SEEN ACROSS THE MORE OPEN
AREAS OF SOUTHEAST MN AND NORTHEAST IA. FURTHER EAST STRONGER WINDS
WILL KICK IN MORE IN THE EVENING AS THE LOW CONTINUES TO PULL TOWARD
UPPER MI.
HEADLINES FOR THIS MAJOR STORM SYSTEM ARE SOMEWHAT COMPLICATED
//SEE BELOW IN THE WWA SECTION FOR DETAILS // DUE TO THE INITIAL
WINTRY MIX DURING THE MORNING...THEN TRANSITIONING INTO WINTER
STORM/BLIZZARD WARNING CRITERIA LATE MORNING INTOTHE AFTERNOON. WILL
BE STICKING WITH A WATCH ACROSS JUNEAU/ADAMS/RICHLAND/GRANT COUNTIES
DUE TO THE FACT THAT THESE COUNTIES WILL BE IN WARMER AIR LONGER AND
SNOW AMOUNTS STILL A BIT UNCERTAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 414 AM CST WED FEB 19 2014
LOOK FOR THE SNOW TO SLOWLY TAPER OFF THROUGH THURSDAY NIGHT...BUT
STRONG/GUSTY NORTHWEST WINDS OF 35-45 MPH WILL CONTINUE...CAUSING
WIDESPREAD BLOWING AND DRIFTING OF THE SNOW.
NOT MUCH TIME WAS SPENT PAST THE TIME FRAME OF THIS MAJOR STORM
SYSTEM. BOTTOM LINE WILL BE COLDER NORTHWEST FLOW ACROSS THE AREA.
APPEARS TO BE A SHOT AT SOME LIGHT SNOW MON/MON NIGHT TIME FRAME
WITH A WEAK MID-LEVEL TROUGH. HIGHS START OFF IN THE 20S ON
FRIDAY...THEN LOOK TO BE IN THE TEENS THROUGH THE WEEKEND INTO EARLY
NEXT WEEK.
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1152 AM CST WED FEB 19 2014
THE 19.12Z NAM APPEARS TO BE AN OUTLIER WHEN COMPARED TO THE OTHER
19.12Z MODELS. DUE THIS...DID NOT CONSIDER THE NAM WHEN MAKING THE
AVIATION FORECAST. EVEN WITH THIS MODEL OUT OF THE MIX...THERE
CONTINUES TO BE SOME QUESTIONS ON HOW FAR WEST WILL WARM AIR WILL
GET LATE THURSDAY MORNING AND AFTERNOON. THE GFS...GEM...AND
UKMET SUGGEST THAT THE WARM AIR WILL ADVANCE AS FAR WEST AS THE
MISSISSIPPI RIVER. THIS WILL AFFECT BOTH THE PRECIPITATION TYPE
AND SNOW AMOUNTS AT LA CROSSE. BUFKIT SOUNDINGS SUGGEST THAT THE
PRECIPITATION WILL START OUT AS SNOW IN LA CROSSE AROUND 20.10Z
AND THEN TRANSITION OVER TO RAIN BY 20.16Z. THERE WAS EVEN SOME
HINTS IN THE RAP THAT THERE MAY BE EVEN SOME FREEZING RAIN
OVERNIGHT. SINCE THIS WAS THE ONLY ONE SHOWING IT AT THAT
TIME...JUST WENT WITH SNOW LATE TONIGHT. MEANWHILE AT KRST THE
PRECIPITATION LOOKS LIKE IT WILL STAY MAINLY SNOW...BUT THERE MAY
BE A BRIEF PERIOD OF SLEET. SNOW TOTALS THROUGH NOON WILL BE
AROUND AN INCH...AND THEN A RAPID INCREASE DURING THE AFTERNOON
AND EARLY EVENING. HOURLY SNOW RATES OF 1 TO 2 INCHES AN HOUR
DURING THE LATE AFTERNOON AND EARLY EVENING. TOTAL SNOWFALL
RANGING FROM 6 TO 10 INCHES.
CEILINGS AND VISIBILITIES AT BOTH TAF SITES WILL QUICKLY BECOME
IFR ONCE THE PRECIPITATION BEGINS.
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 3 AM TO 9 AM CST THURSDAY FOR
WIZ041>044-053>055-061.
WINTER STORM WARNING FROM 9 AM THURSDAY TO 6 AM CST FRIDAY FOR
WIZ017-029-032>034-041-042-053-054.
WINTER STORM WATCH FROM THURSDAY MORNING THROUGH LATE THURSDAY
NIGHT FOR WIZ043-044-055-061.
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.
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...BOYNE