Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 02/21/12
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
337 PM MST SUN FEB 19 2012
.UPDATE...
ISSUED AT 336 PM MST SUN FEB 19 2012
LATEST SHORT RANGE MODELS INDICATED ENERGY AND MOISTURE FOCUSED
OVER SOUTHWEST COLORADO THROUGH THIS EVENING. SNOWFALL WAS ALREADY
PERSISTENT AND HEAVY AT TIMES FROM KCEZ TO KDRO AND RUC13 AND
NAM12 INDICATED THAT SNOW WILL CONTINUE THROUGH THE EVENING. BASED
UPON AMOUNTS ALREADY REPORTED IN CONJUNCTION WITH AREA WEB CAMS...
FELT WINTER WEATHER ADVISORY SHOULD BE ADDED TO THOSE AREAS FOR
THE NEXT SEVERAL HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 150 PM MST SUN FEB 19 2012
MODELS CONTINUE TO ADVERTISE DEEPENING SHORTWAVE WHICH WILL MOVE
ACROSS THE AREA OVERNIGHT. GOOD Q-G FORCING AND ADEQUATE MOISTURE
OVERNIGHT WILL COMBINE TO GENERATE GOOD SNOW ACCUMULATIONS ACROSS
MOST MOUNTAIN LOCATIONS AND NORTHERN AND CENTRAL VALLEYS. MODELS
ARE ALSO SHOWING FAIRLY UNSTABLE LAPSE RATES THIS AFTERNOON AND
EARLY EVENING WHICH WILL AID IN PRECIPITATION PRODUCTION AND MAY
GENERATE SOME ISOLATED LIGHTNING OVER SOUTHERN HALF OF THE
FORECAST AREA. BEHIND THE FRONT NORTHWEST FLOW WILL DOMINATE
OVERNIGHT WITH NORTH TO WEST ASPECTS SEEING THE BEST
ACCUMULATIONS WITH TEMPERATURES COOLING INTO THE FAVORABLE
DENDRITIC GROWTH TEMPERATURE RANGE. HAVE DECIDED TO ADD DEBEQUE TO SILT
CORRIDOR INCLUDING THE PLATEAU VALLEY TO THE WINTER WEATHER
ADVISORY THROUGH TONIGHT. MODELS ARE HITTING THE GRAND MESA AREA
THE HARDEST...LATER SHIFTS NEED TO MONITOR FOR POTENTIAL UPGRADE
OF HIGHLIGHTS. EXPECT SNOWFALL TO DIMINISH FROM WEST TO EAST
ACROSS THE LOWER VALLEY AFTER MIDNIGHT...AND END ACROSS MOUNTAIN
LOCATIONS MONDAY MORNING. EXPECT LINGERING SNOW SHOWERS
ESPECIALLY ALONG THE CONTINENTAL DIVIDE...OTHERWISE COLD
TEMPERATURES WITH CLEARING SKIES ARE EXPECTED DURING THE DAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 150 AM MST SUN FEB 19 2012
MODELS CONTINUE TO SHOW AN UPPER RIDGE OFF THE WEST COAST WITH AN
ASSOCIATED DOWNSTREAM TROUGH OVER THE WESTERN AND CENTRAL STATES
THIS WEEK FOR GENERALLY NORTHWESTERLY FLOW ALOFT OVER THE CENTRAL
ROCKIES. AN EMBEDDED WAVE ZIPS SOUTHEAST ACROSS THE FORECAST AREA
LATE MONDAY NIGHT AND TUESDAY FOR A CHANCE OF PRECIP. THE NORTHERN
STREAM JET NOSES INTO NORTHERN CO TUE NIGHT...AND THEN VACILLATES
BETWEEN WY AND CO THROUGH FRIDAY WHEN IT MOVES OFF TO THE EAST. THIS
PATTERN SHOULD KEEP A PERSISTENT CHANCE OF SNOW FOR THE NORTHERN CO
MTNS THROUGH FRIDAY...WITH THE BETTER CHANCES CURRENTLY LOOKING LIKE
TUESDAY NIGHT AND THEN LATE WED NIGHT-THU. THESE ARE THE TIMES WHEN
THE MODELS SHOW THE UPPER JET OVER NRN CO FOR ADDITIONAL FORCING ON
TOP OF THE NORTHWEST OROGRAPHICS. THE CENTRAL MTNS WILL HAVE A
LESSER CHANCE. MUCH OF EASTERN UT AND SOUTHWEST CO...IN CONTRAST...
SHOULD EXPERIENCE LITTLE OR NO PRECIP WITH CLEAR OR PARTLY SKIES AND
SEASONABLE TEMPS TUE THROUGH SAT.
THIS COULD BE AN INTERESTING WEEK FOR THE NORTHERN CO MTNS...FROM VAIL
NORTHWARD TO THE ELKHEAD AND PARK MTNS. THIS PATTERN OF PERSISTENT
MOIST NW FLOW COULD LEAD TO AN EXTENDED PERIOD OF SNOW FOR THE NRN
MTNS. WHILE SNOWFALL MAY NOT BE PARTICULARLY HEAVY FOR ANY
PARTICULAR PERIOD...OVER TIME SIGNIFICANT ACCUMULATIONS ARE
POSSIBLE. ADD TO THAT SOME GUSTY W TO NW MOUNTAIN WINDS AT TIMES AS
THE JET WAVERS IN AN OUT OF NORTHERN CO.
A PROGRESSIVE PATTERN CONTINUES NEXT WEEK WHEN ANOTHER PACIFIC TROUGH
&&
.AVIATION...(FOR THE 21Z TAFS THROUGH 21Z MONDAY AFTERNOON)
ISSUED AT 150 PM MST SUN FEB 19 2012
THE COLD FRONT ASSOCIATED WITH THIS STORM WILL MOVE THROUGH THE
REMAINDER OF SOUTHEAST UTAH AND WESTERN COLORADO THROUGH THE EARLY
EVENING HOURS TONIGHT. AHEAD OF THE FRONT EXPECT GUSTY SOUTHWEST
WINDS FROM 15 TO 25 MPH WITH GUSTS TO 45 MPH OVER THE HIGHER
TERRAIN...ESPECIALLY ON NORTH- FACING SLOPES AHEAD OF THE FRONT.
WINDS WILL SHIFT TO THE NORTHWEST AND DECREASE BEHIND THE FRONTAL
PASSAGE. GUSTY WINDS AHEAD OF THE FRONT WILL RESULT IN MODERATE
MECHANICAL TURBULENCE IN THE VICINITY OF MOUNTAINS.
SNOW WILL BECOME WIDESPREAD IN THE MOUNTAINS THIS EVENING AND
CONTINUE OVERNIGHT RESULTING IN EXTENSIVE OBSCURATION. LOWER
ELEVATION AIRPORTS ARE LIKELY TO EXPERIENCE MVFR CONDITIONS WITH
AREAS OF IFR CONDITIONS THIS EVENING. MOUNTAIN AIRPORTS WILL SEE
WIDESPREAD IFR CONDITIONS OVERNIGHT WITH SNOW DIMINISHING MONDAY
MORNING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 8 AM MST MONDAY FOR COZ001>004-007-
009-010-012-013-017>019-023.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ021-
022.
UT...WINTER WEATHER ADVISORY UNTIL 8 AM MST MONDAY FOR UTZ023-025.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR UTZ024.
&&
$$
UPDATE...NL
SHORT TERM...MPM
LONG TERM....TGR
AVIATION...MPM
AREA FORECAST DISCUSSION
NWS ALBANY NY
422 PM EST SUN FEB 19 2012
.SYNOPSIS...HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE
REMAINDER OF THIS HOLIDAY WEEKEND. TEMPERATURES WILL MODERATE BACK
ABOVE NORMAL ON TUESDAY...AS THE HIGH SHIFTS OFF THE COAST...AND A
WARM FRONT BRINGS A CHANCE OF RAIN OR SNOW SHOWERS TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
SOUTHEAST CONUS STORM CONTINUES TO TRACK EASTWARD AND WILL EXIT
THE CAROLINA COAST THIS EVENING. A RATHER LARGE SURFACE HIGH THAT
EXTENDS FROM EASTERN CANADA THROUGH THE GREAT LAKES REGION AND
MID-LOWER MISSISSIPPI RIVER VALLEY WILL SLOWLY EDGE EAST TONIGHT.
THE COMPLICATED FACTOR WILL BE THE PERSISTENT STRATOCU DOWNWIND OF
LAKE ONTARIO THAT COVERS MOST OF UPSTATE NY /WEST OF THE HUDSON
RIVER/. RUC13 SEEMS TO BE SLOWLY CAPTURING THIS LOW LEVEL MOISTURE
THAT WANTS TO PERSIST A BIT LONGER. WE WILL FAVOR A PT-MOCLDY
SKIES MAINLY WEST OF THE HUDSON THROUGH THIS EVENING WITH
IMPROVEMENTS EXPECTED OVERNIGHT. MOS NUMBERS TONIGHT ARE VERY
CLOSE TO OUR CURRENT OFFICIAL FORECAST SO LITTLE CHANGES NEEDED.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
BIG BUBBLE NO TROUBLE THROUGH TUESDAY AS SURFACE HIGH WILL BE IN
FIRM CONTROL OVER THE EASTERN THIRD OF THE CONUS. WHILE THERMAL
PROFILES ARE SLIGHTLY COOLER ON MONDAY...WITH AMPLE SUNSHINE AND
LACK OF SNOW COVER...WE WILL FAVOR THE WARMER SIDE OF THE GUIDANCE
ENVELOPE.
THE SHORT WAVE TROUGH AXIS MIGRATING ACROSS THE FOUR CORNERS IS
FORECAST TO EJECT OUT ONTO THE CENTRAL PLAINS MONDAY. THERE IS
FAIRLY GOOD AGREEMENT WITH TRACKING THIS SYSTEM ACROSS THE MID
MISSISSIPPI RIVER VALLEY EARLY TUESDAY THEN WEAKEN AS IT TRACKS
OVER THE EASTERN GREAT LAKES REGION LATE IN THE DAY. THE
COMBINATION OF DIFFUSE ISENTROPIC LIFT AND INCREASING LOW LEVEL
JET DYNAMICS WILL ALLOW FOR CLOUDS TO INCREASE AND INTRODUCE THE
CHANCE FOR PRECIPITATION TUESDAY NIGHT. BUFR PROFILES AND
THICKNESS SCHEMES POINT TOWARD A RAIN/SNOW SHOWER MIXTURE DURING
THE NIGHTTIME HOURS. FORECAST QPF VALUES ARE LIGHT WITH GENERALLY
TWO TENTHS OF AN INCH OR LESS /THE HIGHER VALUES ACROSS THE
FAVORABLE UPSLOPE TERRAIN LOCATIONS WITH THE SOUTHERLY FLOW/. MOS
VALUES ARE IN GENERAL AGREEMENT BUT ONCE AGAIN WE WILL FAVOR THE
WARMER SIDE DUE TO THE COMBINATION OF CLOUDS
INCREASING...STRENGTHENING SOUTHERLY FLOW AND FAVORABLE GROUND
CONDITIONS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MOS GUIDANCE. A WEAK SURFACE LOW WILL BE TRACKING EAST ACROSS NEW
YORK STATE AT THE START OF THE PERIOD. THIS WILL LIKELY RESULT IN
LIGHT AMOUNTS OF MIXED PRECIPITATION WEDNESDAY NIGHT. ON ITS
HEELS...ANOTHER LOW IS EXPECTED TO TRACK GENERALLY EAST ACROSS THE
UPPER MIDWEST AND LIFT JUST WEST OF OUR AREA THURSDAY NIGHT.
HOWEVER...THIS LOW IS EXPECTED TO INTENSIFY...PROVIDING GREATER
QPFS. GIVEN THE TRACK AND EXPECTED INTENSIFICATION OF THE LOW...
CAN`T RULE OUT THE POSSIBILITY OF A TRANSITION TO FREEZING RAIN AS
THINGS SPIN UP THURSDAY NIGHT BUT GOOD WARM SURFACE ADVECTION
GETTING INTO OUR AREA IS QUESTIONABLE AS IT/S MID-LEVEL DYNAMICS THAT
APPEAR TO HAVE THE UPPER HAND.
THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL PULL THROUGH ON
FRIDAY...BUT THE MAIN COLD AIR BEHIND THE SYSTEM WILL HOLD BACK WITH
A WEAK IMPULSE THAT WILL MOVE THROUGH FRIDAY NIGHT OR SATURDAY...
POSSIBLY SETTING UP A LAKE EFFECT PATTERN FOR THE WEEKEND. THIS
MEANS THAT THE SHOWERY DAYTIME ACTIVITY BEHIND THE SYSTEM ON FRIDAY
WILL BE MAINLY IN THE FORM OF LIQUID OR A MIX...BEFORE COLD
INFILTRATION TURNS IT BACK TO SNOW SHOWERS FRIDAY NIGHT AS IT WINDS
DOWN BEFORE THE LAKE EFFECT MACHINE KICKS IN.
SATURDAY WILL BE NOTICEABLY COLDER...WITH A NORTHWEST FLOW AND
THE LAKE EFFECT ACTIVITY IN THE WESTERN ADIRONDACKS SATURDAY AND
SATURDAY NIGHT. FROM LAKE GEORGE ON SOUTH...GOING NEAR ZERO POPS
BUT DO HAVE SLT CHC POPS MOST OF THE REGION SUNDAY NIGHT. HIGH
PRESSURE WILL BE STARTING TO BUILD IN FROM THE SOUTH DURING THAT
TIME.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL CONTINUE AT ALL TAF SITES THROUGH THE
FORECAST PERIOD ENDING AT 18 UTC ON MONDAY. ASIDE FROM SOME
DIURNAL CU/SC...SKIES WILL BE NEARLY CLEAR OVERNIGHT FOR ALL TAF
SITES. SOME SCT PASSING HIGH CIRRUS MAY MOVE OVER KPOU TONIGHT DUE
TO A STORM SYSTEM WELL TO THE SOUTH...OTHERWISE THE CLEAR SKIES
WILL CONTINUE INTO THE OVERNIGHT HOURS FOR KGFL/KALB. A SHORTWAVE
MOVING WELL NORTHEAST OF THE REGION ON MONDAY COULD ALLOW FOR A
FEW STRAOCU/CU FOR KGFL FOR THE LATE MORNING TO AFTN HOURS ON
MONDAY...OTHERWISE SKIES WILL CONTINUE NEARLY CLEAR AT THE OTHER
SITES INTO THE WASHINGTON/S BIRTHDAY HOLIDAY.
NORTHERLY WINDS WILL BE ABOUT 5-10 KTS THIS AFTN AND DIMINISH TO
NEARLY CALM OVERNIGHT. WITHIN DAYTIME MIXING ON MONDAY...WINDS MAY
ONCE AGAIN RETURN TO ABOUT 5-10 KTS FOR ALL TERMINALS FROM A
NORTHERLY DIRECTION.
OUTLOOK...
MON NIGHT-TUE...VFR...NO SIG WX.
TUE NGT...VFR/MVFR. CHC -SHRA/-SHSN.
WED...MAINLY VFR. SLIGHT CHC -SHRA/-SHSN.
WED NIGHT-THU...VFR/MVFR. CHC -SHRA/-SHSN.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS. DRY WEATHER
WILL PERSIST UNTIL TUESDAY NIGHT...WHEN A FRONTAL BOUNDARY WILL
BRING LIGHT PRECIPITATION IN THE FORM OF RAIN OR SNOW SHOWERS.
A MORE WIDESPREAD AND HEAVIER PRECIPITATION SYSTEM MAY IMPACT THE
HYDRO SERVICE AREA DURING THE SECOND HALF OF THE WEEK WITH SOME
RAIN AND SNOW. THERE IS CONSIDERABLE UNCERTAINTY WITH THE
EVOLUTION AND TRACK OF THIS LATER WEEK SYSTEM AT THIS TIME.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...ELH
AVIATION...FRUGIS
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS ALBANY NY
408 PM EST SUN FEB 19 2012
.SYNOPSIS...HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE
REMAINDER OF THIS HOLIDAY WEEKEND. TEMPERATURES WILL MODERATE BACK
ABOVE NORMAL ON TUESDAY...AS THE HIGH SHIFTS OFF THE COAST...AND A
WARM FRONT BRINGS A CHANCE OF RAIN OR SNOW SHOWERS TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
SOUTHEAST CONUS STORM CONTINUES TO TRACK EASTWARD AND WILL EXIT
THE CAROLINA COAST THIS EVENING. A RATHER LARGE SURFACE HIGH THAT
EXTENDS FROM EASTERN CANADA THROUGH THE GREAT LAKES REGION AND
MID-LOWER MISSISSIPPI RIVER VALLEY WILL SLOWLY EDGE EAST TONIGHT.
THE COMPLICATED FACTOR WILL BE THE PERSISTENT STRATOCU DOWNWIND OF
LAKE ONTARIO THAT COVERS MOST OF UPSTATE NY /WEST OF THE HUDSON
RIVER/. RUC13 SEEMS TO BE SLOWLY CAPTURING THIS LOW LEVEL MOISTURE
THAT WANTS TO PERSIST A BIT LONGER. WE WILL FAVOR A PT-MOCLDY
SKIES MAINLY WEST OF THE HUDSON THROUGH THIS EVENING WITH
IMPROVEMENTS EXPECTED OVERNIGHT. MOS NUMBERS TONIGHT ARE VERY
CLOSE TO OUR CURRENT OFFICIAL FORECAST SO LITTLE CHANGES NEEDED.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
BIG BUBBLE NO TROUBLE THROUGH TUESDAY AS SURFACE HIGH WILL BE IN
FIRM CONTROL OVER THE EASTERN THIRD OF THE CONUS. WHILE THERMAL
PROFILES ARE SLIGHTLY COOLER ON MONDAY...WITH AMPLE SUNSHINE AND
LACK OF SNOW COVER...WE WILL FAVOR THE WARMER SIDE OF THE GUIDANCE
ENVELOPE.
THE SHORT WAVE TROUGH AXIS MIGRATING ACROSS THE FOUR CORNERS IS
FORECAST TO EJECT OUT ONTO THE CENTRAL PLAINS MONDAY. THERE IS
FAIRLY GOOD AGREEMENT WITH TRACKING THIS SYSTEM ACROSS THE MID
MISSISSIPPI RIVER VALLEY EARLY TUESDAY THEN WEAKEN AS IT TRACKS
OVER THE EASTERN GREAT LAKES REGION LATE IN THE DAY. THE
COMBINATION OF DIFFUSE ISENTROPIC LIFT AND INCREASING LOW LEVEL
JET DYNAMICS WILL ALLOW FOR CLOUDS TO INCREASE AND INTRODUCE THE
CHANCE FOR PRECIPITATION TUESDAY NIGHT. BUFR PROFILES AND
THICKNESS SCHEMES POINT TOWARD A RAIN/SNOW SHOWER MIXTURE DURING
THE NIGHTTIME HOURS. FORECAST QPF VALUES ARE LIGHT WITH GENERALLY
TWO TENTHS OF AN INCH OR LESS /THE HIGHER VALUES ACROSS THE
FAVORABLE UPSLOPE TERRAIN LOCATIONS WITH THE SOUTHERLY FLOW/. MOS
VALUES ARE IN GENERAL AGREEMENT BUT ONCE AGAIN WE WILL FAVOR THE
WARMER SIDE DUE TO THE COMBINATION OF CLOUDS
INCREASING...STRENGTHENING SOUTHERLY FLOW AND FAVORABLE GROUND
CONDITIONS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FORTHCOMING SHORTLY...
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL CONTINUE AT ALL TAF SITES THROUGH THE
FORECAST PERIOD ENDING AT 18 UTC ON MONDAY. ASIDE FROM SOME
DIURNAL CU/SC...SKIES WILL BE NEARLY CLEAR OVERNIGHT FOR ALL TAF
SITES. SOME SCT PASSING HIGH CIRRUS MAY MOVE OVER KPOU TONIGHT DUE
TO A STORM SYSTEM WELL TO THE SOUTH...OTHERWISE THE CLEAR SKIES
WILL CONTINUE INTO THE OVERNIGHT HOURS FOR KGFL/KALB. A SHORTWAVE
MOVING WELL NORTHEAST OF THE REGION ON MONDAY COULD ALLOW FOR A
FEW STRAOCU/CU FOR KGFL FOR THE LATE MORNING TO AFTN HOURS ON
MONDAY...OTHERWISE SKIES WILL CONTINUE NEARLY CLEAR AT THE OTHER
SITES INTO THE WASHINGTON/S BIRTHDAY HOLIDAY.
NORTHERLY WINDS WILL BE ABOUT 5-10 KTS THIS AFTN AND DIMINISH TO
NEARLY CALM OVERNIGHT. WITHIN DAYTIME MIXING ON MONDAY...WINDS MAY
ONCE AGAIN RETURN TO ABOUT 5-10 KTS FOR ALL TERMINALS FROM A
NORTHERLY DIRECTION.
OUTLOOK...
MON NIGHT-TUE...VFR...NO SIG WX.
TUE NGT...VFR/MVFR. CHC -SHRA/-SHSN.
WED...MAINLY VFR. SLIGHT CHC -SHRA/-SHSN.
WED NIGHT-THU...VFR/MVFR. CHC -SHRA/-SHSN.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED OVER THE NEXT 5 DAYS. DRY WEATHER
WILL PERSIST UNTIL TUESDAY NIGHT...WHEN A FRONTAL BOUNDARY WILL
BRING LIGHT PRECIPITATION IN THE FORM OF RAIN OR SNOW SHOWERS.
A MORE WIDESPREAD AND HEAVIER PRECIPITATION SYSTEM MAY IMPACT THE
HYDRO SERVICE AREA DURING THE SECOND HALF OF THE WEEK WITH SOME
RAIN AND SNOW. THERE IS CONSIDERABLE UNCERTAINTY WITH THE
EVOLUTION AND TRACK OF THIS LATER WEEK SYSTEM AT THIS TIME.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...ELH
AVIATION...FRUGIS
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
823 PM EST MON FEB 20 2012
.UPDATE...
DELAYED ONSET OF PRECIPITATION PER SLOWER SOLUTION FROM BOTH 18Z NAM
AND LATEST HRRR GUIDANCE. ISENTROPIC PRECIP SHIELD WILL EXPAND
ACROSS THE AREA FROM WEST TO EAST DURING THE EARLY MORNING HOURS
AS MOISTURE PROFILE IMPROVES. INITIAL EVAPORATIVE COOLING COUPLED
WITH DYNAMIC LIFT SHOULD COOL THE COLUMN ENOUGH TO ALLOW FOR A RAIN
SNOW MIX THROUGH THE MORNING HOURS. ALSO ADJUSTED THE RAIN/SNOW
LINE SLIGHTLY NORTHWARD TO ACCOUNT FOR SLIGHTLY WARMER SOLUTION
TUE MORNING AS THE SHORTWAVE CURRENTLY OVER KANSAS PER WV IMAGERY
GOES NEGATIVE TILT AND ATTEMPTS TO PHASE WITH THE NORTHERN STREAM
TROUGH DURING THE MORNING HOURS TUE.
ADJUSTED NEAR TERM TEMPS DOWNWARD TO ACCOUNT FOR MOST RECENT
OBSERVATIONS AND TREND IN LATEST HRRR.
&&
.PREV DISCUSSION... /ISSUED 720 PM EST MON FEB 20 2012/
AVIATION /00 UTC TAFS/...
ADJUSTMENTS MADE TO ACCOUNT FOR SLOWER TREND PER RUC/HRRR 3KM/18 UTC
NAM WRT PRECIP ONSET. LARGE 200 MB PLUS 950MB CONDENSATION PRESSURE
DEFICITS ATTM FINALLY RETREAT INTO SW ONT/MI THUMB TOWARD DAYBREAK
WITH LEADING EDGE OF XTRMLY SHARP GRADIENT OF SHARPLY LWR/SATURATED
CPD ALONG KMSN-KVPZ-KMIE LINE AT 12 UTC TUE...LKLY LEADING EDGE OF
PRECIP TO SWING EWD SHORTLY THEREAFTER. CONTD MENTION OF MIXED
PRECIP WITH EVAPORATIVE AND DYNAMIC LIFT INITIALLY COOLING COLUMN.
CRNT STRONG ERN KS WAVE PER WV IMAGERY FCST TO LIFTOUT NEWD AND
DAMPEN INTO NEG TILT AS AT LEAST PARTIAL PHASING WITH SASK/DAKOTAS
WAVE COMMENCES. THIS WOULD SUGGEST A LARGER MORE THOROUGHLY MIXED
WARM SECTOR BLYR CONDS OVER THE SRN GRTLKS/NRN INDIANA REGION.
TOP/DOWN FCST WET BULB AND THERMAL PROFILES WITH WARM SFC-3KFT TEMPS
BYND 15 UTC SUPPORTIVE OF LIQUID PTYPE. SUB CLOUD SATURATION HOWEVER
TO STILL YIELD DETERIORATING FLIGHT CONDS WITH HIGH CONFIDENCE FOR
AT LEAST FUEL ALT CONDS 15-24 UTC TUE. SIG LESSER CONFIDENCE FOR
POTNL IFR AND WL DEFER TO LATER FCST ITERATIONS FOR A MORE TARGETED
IFR FCST WRT TIMING/DURATION IF NEEDED.
SHORT TERM...
FOCUS IN SHORT TERM CENTERS ON APPROACHING SHORT WAVE TROUGH AND
PRECIPITATION TYPE LATE TONIGHT AND TUESDAY MORNING. 12Z GUIDANCE IN
GOOD AGREEMENT AND LITTLE CHANGE FROM PRIOR RUNS. POTENT SHORT WAVE
CURRENTLY ACROSS CENTRAL PLAINS WILL LIFT NORTHEAST TONIGHT AND TAKE
ON A NEGATIVE TILT AS IT MOVES THROUGH THE GREAT LAKES. THIS WILL
RESULT IN BRIEF BUT INTENSE LIFT ACROSS THE AREA AS LOW LEVEL JET
ADVECTS INTO AREA. ISENTROPIC SURFACES BECOME SATURATED TOWARD 12Z
WITH STRONG LIFT DEPICTED AS WELL.
THERMAL PROFILES CONTINUE TO BE BORDERLINE FOR RAIN AND SNOW WITH
SNOW POSSIBLE AT ONSET GIVEN EVAPORATIVE COOLING PROCESSES WITH VERY
DRY AIRMASS INITIALLY. ONCE SATURATED..STRONG DYNAMIC LIFT MAY BE
ABLE TO KEEP PCPN AS SNOW OR AT LEAST MIXED. PREVIOUS FORECAST HAS
THIS HANDLED WELL WITH EXCELLENT DETAIL IN GRIDS. GIVEN LITTLE
CHANGE IN 12Z RUNS SEE NO REASON TO DEVIATE MUCH FROM PRIOR WEATHER
GRIDS OTHER THAN A FEW MINOR TWEAKS.
SOME SNOW ACCUMULATIONS REMAIN POSSIBLE...ESPECIALLY WEST AND NORTH
BUT TOTALLY DEPENDENT ON STRONG LIFT COOLING COLUMN ENOUGH TO GO
OVER TO ALL SNOW. THIS SYSTEM WILL BE CONVECTIVE IN NATURE AND THIS
ALREADY BEING SEEN UPSTREAM WHERE SOME LIGHTNING HAS BEEN NOTED OVER
EASTERN KS EARLY THIS AFTERNOON. THIS WOULD AID IN CHANGEOVER TO
SNOW. WILL KEEP ACCUMS IN THE ONE INCH OR LESS RANGE WITH THIS
PACKAGE BUT CERTAINLY WILL BE LOOKED AT CLOSELY THIS EVENING AND
OVERNIGHT PRIOR TO ONSET.
LINGERING PCPN EXPECTED ON TUESDAY. SECONDARY WEAKER SHORT WAVE
MOVES THROUGH TUE NIGHT WITH NAM SHOWING SOME LIGHT PCPN WITH IT.
HAVE ADDED A SLIGHT CHANCE POP FOR THIS FEATURE THOUGH IT COULD END
UP ONLY PRODUCING DRIZZLE OR SPRINKLE/FLURRY. FEW CHANGES NEEDED TO
TEMPS.
LONG TERM.../WEDNESDAY THROUGH MONDAY/
ACTIVE PATTERN IN STORE FOR THE EXTENDED PERIOD WITH SEVERAL CHANCES
FOR RAIN/SNOW.
TROUGH WILL BE EXITING THE REGION AT THE START OF THE
PERIOD...LEAVING BEHIND CLEARING SKIES AND A RETURN TO ABOVE NORMAL
TEMPS WITH COLD AIR BEING SHUNTED NORTH. WARM FRONT WILL SETUP TO
THE SOUTH AND MAKE A RUN FOR THE AREA WEDS NGT INTO THURS. MODELS
VARY ON HANDLING OF THIS FEATURE RANGING FROM STALLING OUT ACROSS
THE AREA TO PUSHING WELL NORTH. CHANCE FOR RAIN EXISTS ALONG AND
AHEAD OF THIS BOUNDARY BUT HAVE BEEN HELD IN CHC RANGE GIVEN MODEL
DIFFERENCES. GULF MSTR WILL REMAIN CUT OFF AT THIS POINT BUT NAM12
12Z RUN BRINGS A DECENT WAVE ALONG THE FRONT WITH A TENTH TO QUARTER
INCH OR MORE OF PRECIP THURS AFTERNOON/EVE. FOR SAME REASONS AS
POPS...HAVE KEPT TEMPS IN CHECK ON THURSDAY FOR THE TIME BEING WITH
PROXIMITY OF WARM FRONT AND SERIES OF WEAK DISTURBANCES LIKELY TO
WRECK HAVOC WITH AFTERNOON HIGHS. IF FRONT CAN SURGE NORTH AND SKIES
CLEAR...READINGS WELL INTO THE 50S WILL BE IN STORE.
LONGWAVE TROUGH WILL STRENGTHEN TO THE WEST WITH NORTHERN AND
SOUTHERN STREAM ENERGY MOVING TOWARDS THE AREA THURS NGT INTO FRI.
GFS KEEPS MAIN SFC LOW FURTHER NORTH WITH DEEPENING OF LOW INTO NEW
ENGLAND BY FRI MORNING. ECMWF KEEPS SOUTHERN STREAM SYSTEM STRONGEST
WITH INTENSIFICATION AND POTENTIAL FOR WRAP AROUND/TROWAL PRECIP
INTO THE AREA THURS NGT INTO FRI. HAVE HELD SHY OF LIKELY POPS GIVEN
ABUNDANCE OF SCENARIOS THAT MAY UNFOLD.
COLDER AIR WILL ARRIVE IN THE WAKE OF THE SYSTEM WITH CHANCES FOR
LAKE EFFECT SNOW SHOWERS STILL ON TAP FRI INTO SAT. HAVE KEPT WITH
GENERAL IDEA OF PREV FORECAST. YET ANOTHER WAVE MOVES IN TOWARDS THE
END OF THE PERIOD WITH CHANCE FOR RAIN ARRIVING ONCE AGAIN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
AVIATION...MURPHY
UPDATE...BENTLEY
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
936 PM CST MON FEB 20 2012
.UPDATE...
ISSUED AT 933 PM CST MON FEB 20 2012
WINDS CONTINUE TO DECREASE ACROSS NORTH CENTRAL KANSAS THIS
EVENING. GIVEN THE TRENDS FROM THE WINDS AT HAYS, GREAT BEND, AND
PRATT WILL ALLOW THE WIND ADVISORY EXPIRE AT 10 PM.
UPDATE ISSUED AT 820 PM CST MON FEB 20 2012
AS OF 02Z THE SURFACE LOW WAS LOCATED JUST NORTH OF SALINA WITH
THE TIGHTEST SURFACE PRESSURE GRADIENT EXTENDING SOUTHWEST OF THIS
SURFACE LOW TO NEAR HAYS AND PRATT. THE MESONET MONITOR INDICATED THAT
WIND SPEEDS AT OR ABOVE ADVISORY CRITERIA CONTINUES WHERE THE
SURFACE PRESSURE GRADIENT WAS TIGHTEST. FURTHER SOUTHWEST WHERE THE
GRADIENT HAS BEGUN TO WEAKEN THE WINDS SPEEDS HAD ALREADY
DECREASED INTO THE 15 TO 25 MPH RANGE. SINCE WINDS WILL CONTINUE
TO DECREASE ACROSS SOUTHWEST KANSAS EARLY TONIGHT AS THE SURFACE
LOW MOVES EAST WILL GO AHEAD AND CANCEL PARTS OF THE WIND
ADVISORY....MAINLY ALONG AND SOUTHWEST OF A WAKEENEY TO GREENSBURG
TO MEDICINE LODGE LINE.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 235 PM CST MON FEB 20 2012
FORECAST CONCERNS ARE THE SNOW AND HIGH WINDS LATE THIS AFTERNOON
INTO EARLY EVENING. THIS MORNINGS UA ANALYSIS SHOWED A STRONG
UPPER TROUGH ALONG THE EASTERN SLOPES OF THE ROCKIES WITH A CLOSED
CIRCULATION SHOWING UP OVER NORTHEAST COLORADO. THIS FEATURE HAS BEEN
MOVING STEADILY EAST THROUGH WESTERN KANSAS AND THE OK/TX PANHANDLES
THIS AFTERNOON. RUC ANALYSIS SHOWED A FAIRLY INTENSE MID LEVEL
VORT MAX ACROSS THE AREA WITH STRONG PVA AND MID LEVEL UVV OCCURRING
OVER SOUTHWEST KANSAS. THIS LINES UP WELL WITH AN AREA OF LIGHT
TO MODERATE SNOW WHICH HAS BEEN TRANSLATING EAST THROUGH SOUTHWEST
KANSAS TODAY.
THE AREAS OF RAIN AND SNOW SHOULD CONTINUE TO WORK EASTWARD ACROSS
SOUTHWEST AND TOWARD CENTRAL KANSAS THROUGH THE LATE AFTERNOON
HOURS BUT SHOULD BEGIN TO DIMINISH RAPIDLY TOWARD SUNSET AS THE
TROUGH AXIS MOVES EAST OF THE AREA.
HIGH WINDS HAVE BEEN SLOW TO MATERIALIZE ACROSS SOUTHWEST KANSAS
THIS AFTERNOON PARTLY DUE TO THE WIDESPREAD CLOUD COVER AND
REDUCED MIXING. AM STILL CONCERNED THAT WE COULD SEE A WINDOW OF
OPPORTUNITY AS THE GRADIENT INCREASES ON THE BACKSIDE OF THE LOWER
ATMOSPHERIC TROUGH AXIS. RUC MODEL SOUNDINGS THROUGHOUT THE DAY
HAVE BEEN SHOWING 50-60 KNOT WINDS DEVELOPING IN THE 850-875 MB
LAYER THROUGH THE 21Z-01Z TIME PERIOD. WILL KEEP THE CURRENT
HEADLINES IN PLACE THROUGH THE EARLY EVENING HOURS.
THE UPPER LEVEL SHORTWAVE TROUGH WILL MOVE RAPIDLY EAST OUT OF THE
PLAINS TONIGHT WITH WESTERLY FLOW OVER THE HIGH PLAINS. ANOTHER
BROAD SHORTWAVE TROUGH IS FORECAST TO MOVE SOUTHEAST OVER THE
CENTRAL CONUS DURING THE DAY TUESDAY. ONLY SOME SCATTERED HIGH
CLOUDINESS IS EXPECTED WITH THE SHORTWAVE. LOW LEVEL DOWNSLOPE
FLOW SHOULD HELP BOOST TEMPERATURES INTO THE 55 TO 60 DEGREE RANGE
FOR AFTERNOON HIGHS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 543 PM CST MON FEB 20 2012
NORTHWESTERLY MID TO HIGH LEVEL FLOW WILL DEVELOP BY TUESDAY NIGHT
AND PERSIST THROUGH FRIDAY. THIS IS USUALLY A DRY REGIME FOR
WESTERN KANSAS AS THE GULF OF MEXICO TENDS TO BE SHUT OFF.
DOWNSLOPE WESTERLY LOW-LEVEL FLOW WILL DEVELOP TUESDAY NIGHT WITH
850MB TEMPERATURES RISING TO BETWEEN 6 AND 9C. HOWEVER, GIVEN THE
EXPECTED CLEAR SKIES AND ONLY 5 TO 10 KT WINDS, TEMPERATURES WILL
PROBABLY STILL DROP INTO THE LOWER 30S. WEDNESDAY WILL BE A WARM DAY
WITH WESTERLY DOWNSLOPE FLOW PERSISTING AS SURFACE LOW PRESSURE DEVELOPS
ACROSS NEBRASKA AHEAD OF A SHORTWAVE TROUGH. IN THESE SITUATIONS IN
LATE WINTER AND EARLY SPRING TEMPERATURES TYPICALLY GET WARMER THAN
ANY OF THE MODELS INDICATE. GIVEN THE EXPECTED WESTERLY SURFACE
WINDS AT 10 TO 20 KTS, A DEEP, DRY ADIABATIC LAYER WILL DEVELOP.
TEMPERATURES OUGHT TO EASILY REACH INTO THE UPPER 60S TO LOWER 70S.
AS IS TYPICAL IN DOWNSLOPE REGIMES WHEN THE WEST WINDS PROGRESS ALL
THE WAY INTO CENTRAL KANSAS, THE VERY WARMEST READINGS MAY BE ON THE
LOWER TERRAIN OF SOUTHERN CLARK, COMANCHE AND BARBER COUNTIES
(ELEVATIONS 1500-2000FT) AS OPPOSED TO DODGE CITY (2600FT), GARDEN
CITY (2900FT) AND SYRACUSE (3300FT).
COOL SURFACE HIGH PRESSURE WILL MOVE INTO WESTERN KANSAS LATE
WEDNESDAY NIGHT AND THURSDAY IN THE WAKE OF THE AFOREMENTIONED
SHORTWAVE TROUGH. LOW TEMPERATURES WEDNESDAY NIGHT WILL BE TRICKY.
IT COULD ACTUALLY GET COLDER AHEAD OF THE FRONT IF WINDS CAN DROP OFF
TO LIGHT AND VARIABLE. VERTICAL MIXING IMMEDIATELY BEHIND THE FRONT
MAY KEEP LOCATIONS NEAR INTERSTATE 70 WARMER. BUT THIS IS SUBJECT
TO CHANGES IN FRONTAL TIMING. IN THE ABSENCE OF ARCTIC AIR, HIGH
TEMPERATURES SHOULD COOL DOWN TO NEAR SEASONAL VALUES, WITH HIGHS IN
THE UPPER 40S TO LOWER 50S THURSDAY AND UPPER 40S TO MID 50S FOR
FRIDAY.
BY SATURDAY AND SUNDAY, THE MODELS INDICATE UPPER-LEVEL TROUGHING
DEVELOPING ACROSS THE WESTERN UNITED STATES, THE SPEED AND AMPLITUDE
OF WHICH IS DIFFERENT DEPENDING ON THE MODEL. THIS SYSTEM WILL BRING
SOME ARCTIC AIR SOUTHWARD INTO THE NORTHERN OR EVEN CENTRAL PLAINS BY
SUNDAY. HOW FAST THIS ARCTIC FRONT MOVES THROUGH KANSAS IS
UNCERTAIN. BUT IT LOOKS LIKE TEMPERATURES WILL BE GETTING MUCH
COLDER SOMETIME BETWEEN SUNDAY AND TUESDAY (FEBRUARY 26-28TH). BUT
THERE WILL BE A VERY SHARP TEMPERATURE GRADIENT ALONG THE LEADING
EDGE OF THE ARCTIC AIR. SO SOME PLACES IN THE SOUTHERN PLAINS
(POSSIBLY INCLUDING SOUTHERN KANSAS) COULD GET VERY WARM SUNDAY OR
MONDAY (POSSIBLY 70S) BEFORE THE ARCTIC AIR ARRIVES. IT IS TOO EARLY
TO TELL IF ANY PRECIPITATION WILL ACCOMPANY THIS SYSTEM. AT THIS
POINT IT APPEARS THAT MOST OF THE PRECIPITATION WILL BE IN THE WARM
SECTOR AND WELL EAST OF HERE. HOWEVER, IF THE SYSTEM IS SLOWER AND
FURTHER SOUTH THAN WE CURRENTLY EXPECT, THEN SOME RAIN/SNOW WOULD BE
POSSIBLE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 531 PM CST MON FEB 20 2012
LOW IFR STATUS AND STEADY LIGHT SNOW CONTINUES ACROSS PORTIONS OF
SOUTHWEST KANSAS UNDER A COLD UPPER LOW AS IT SLOWLY MOVE EAST
ACROSS THE AREA LATE THIS AFTERNOON. SATELLITE LOOP SUPPORTS THE
18Z NAM BUFR SOUNDINGS THAT RAPID CLEARING WILL DEVELOP EARLY
TONIGHT AS THIS UPPER LOW MOVES ACROSS CENTRAL KANSAS. STRONG
NORTHWEST WINDS HOWEVER WILL CONTINUE FOR SEVERAL HOURS AFTER
SUNSET BASED ON THE TIGHT SURFACE PRESSURE GRADIENT AND 30-40KT
BOUNDARY LAYER WINDS. AFTER 03Z HOWEVER THESE WINDS WILL START TO
SUBSIDE AND BY 06Z WINDS ACROSS THE ENTIRE AREA ARE EXPECTED TO
FALL BACK TO AROUND 10KTS. VFR CONDITIONS AND 10KT WEST WINDS WILL
THEN CONTINUE THROUGH TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 22 58 30 71 / 90 0 0 0
GCK 20 56 28 70 / 0 0 0 0
EHA 21 57 33 70 / 0 0 0 0
LBL 21 58 30 72 / 0 0 0 0
HYS 25 56 30 69 / 0 0 0 0
P28 27 60 32 73 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM CST THIS EVENING FOR KSZ031-046-065-
066-079-081.
&&
$$
UPDATE...BURGERT
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
826 PM CST MON FEB 20 2012
.UPDATE...
ISSUED AT 820 PM CST MON FEB 20 2012
AS OF 02Z THE SURFACE LOW WAS LOCATED JUST NORTH OF SALINA WITH
THE TIGHTEST SURFACE PRESSURE GRADIENT EXTENDING SOUTHWEST OF THIS
SURFACE LOW TO NEAR HAYS AND PRATT. THE MESONET MONITOR INDICATED THAT
WIND SPEEDS AT OR ABOVE ADVISORY CRITERIA CONTINUES WHERE THE
SURFACE PRESSURE GRADIENT WAS TIGHTEST. FURTHER SOUTHWEST WHERE THE
GRADIENT HAS BEGUN TO WEAKEN THE WINDS SPEEDS HAD ALREADY
DECREASED INTO THE 15 TO 25 MPH RANGE. SINCE WINDS WILL CONTINUE
TO DECREASE ACROSS SOUTHWEST KANSAS EARLY TONIGHT AS THE SURFACE
LOW MOVES EAST WILL GO AHEAD AND CANCEL PARTS OF THE WIND
ADVISORY....MAINLY ALONG AND SOUTHWEST OF A WAKEENEY TO GREENSBURG
TO MEDICINE LODGE LINE.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 235 PM CST MON FEB 20 2012
FORECAST CONCERNS ARE THE SNOW AND HIGH WINDS LATE THIS AFTERNOON
INTO EARLY EVENING. THIS MORNINGS UA ANALYSIS SHOWED A STRONG
UPPER TROUGH ALONG THE EASTERN SLOPES OF THE ROCKIES WITH A CLOSED
CIRCULATION SHOWING UP OVER NORTHEAST COLORADO. THIS FEATURE HAS BEEN
MOVING STEADILY EAST THROUGH WESTERN KANSAS AND THE OK/TX PANHANDLES
THIS AFTERNOON. RUC ANALYSIS SHOWED A FAIRLY INTENSE MID LEVEL
VORT MAX ACROSS THE AREA WITH STRONG PVA AND MID LEVEL UVV OCCURRING
OVER SOUTHWEST KANSAS. THIS LINES UP WELL WITH AN AREA OF LIGHT
TO MODERATE SNOW WHICH HAS BEEN TRANSLATING EAST THROUGH SOUTHWEST
KANSAS TODAY.
THE AREAS OF RAIN AND SNOW SHOULD CONTINUE TO WORK EASTWARD ACROSS
SOUTHWEST AND TOWARD CENTRAL KANSAS THROUGH THE LATE AFTERNOON
HOURS BUT SHOULD BEGIN TO DIMINISH RAPIDLY TOWARD SUNSET AS THE
TROUGH AXIS MOVES EAST OF THE AREA.
HIGH WINDS HAVE BEEN SLOW TO MATERIALIZE ACROSS SOUTHWEST KANSAS
THIS AFTERNOON PARTLY DUE TO THE WIDESPREAD CLOUD COVER AND
REDUCED MIXING. AM STILL CONCERNED THAT WE COULD SEE A WINDOW OF
OPPORTUNITY AS THE GRADIENT INCREASES ON THE BACKSIDE OF THE LOWER
ATMOSPHERIC TROUGH AXIS. RUC MODEL SOUNDINGS THROUGHOUT THE DAY
HAVE BEEN SHOWING 50-60 KNOT WINDS DEVELOPING IN THE 850-875 MB
LAYER THROUGH THE 21Z-01Z TIME PERIOD. WILL KEEP THE CURRENT
HEADLINES IN PLACE THROUGH THE EARLY EVENING HOURS.
THE UPPER LEVEL SHORTWAVE TROUGH WILL MOVE RAPIDLY EAST OUT OF THE
PLAINS TONIGHT WITH WESTERLY FLOW OVER THE HIGH PLAINS. ANOTHER
BROAD SHORTWAVE TROUGH IS FORECAST TO MOVE SOUTHEAST OVER THE
CENTRAL CONUS DURING THE DAY TUESDAY. ONLY SOME SCATTERED HIGH
CLOUDINESS IS EXPECTED WITH THE SHORTWAVE. LOW LEVEL DOWNSLOPE
FLOW SHOULD HELP BOOST TEMPERATURES INTO THE 55 TO 60 DEGREE RANGE
FOR AFTERNOON HIGHS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 543 PM CST MON FEB 20 2012
NORTHWESTERLY MID TO HIGH LEVEL FLOW WILL DEVELOP BY TUESDAY NIGHT
AND PERSIST THROUGH FRIDAY. THIS IS USUALLY A DRY REGIME FOR
WESTERN KANSAS AS THE GULF OF MEXICO TENDS TO BE SHUT OFF.
DOWNSLOPE WESTERLY LOW-LEVEL FLOW WILL DEVELOP TUESDAY NIGHT WITH
850MB TEMPERATURES RISING TO BETWEEN 6 AND 9C. HOWEVER, GIVEN THE
EXPECTED CLEAR SKIES AND ONLY 5 TO 10 KT WINDS, TEMPERATURES WILL
PROBABLY STILL DROP INTO THE LOWER 30S. WEDNESDAY WILL BE A WARM DAY
WITH WESTERLY DOWNSLOPE FLOW PERSISTING AS SURFACE LOW PRESSURE DEVELOPS
ACROSS NEBRASKA AHEAD OF A SHORTWAVE TROUGH. IN THESE SITUATIONS IN
LATE WINTER AND EARLY SPRING TEMPERATURES TYPICALLY GET WARMER THAN
ANY OF THE MODELS INDICATE. GIVEN THE EXPECTED WESTERLY SURFACE
WINDS AT 10 TO 20 KTS, A DEEP, DRY ADIABATIC LAYER WILL DEVELOP.
TEMPERATURES OUGHT TO EASILY REACH INTO THE UPPER 60S TO LOWER 70S.
AS IS TYPICAL IN DOWNSLOPE REGIMES WHEN THE WEST WINDS PROGRESS ALL
THE WAY INTO CENTRAL KANSAS, THE VERY WARMEST READINGS MAY BE ON THE
LOWER TERRAIN OF SOUTHERN CLARK, COMANCHE AND BARBER COUNTIES
(ELEVATIONS 1500-2000FT) AS OPPOSED TO DODGE CITY (2600FT), GARDEN
CITY (2900FT) AND SYRACUSE (3300FT).
COOL SURFACE HIGH PRESSURE WILL MOVE INTO WESTERN KANSAS LATE
WEDNESDAY NIGHT AND THURSDAY IN THE WAKE OF THE AFOREMENTIONED
SHORTWAVE TROUGH. LOW TEMPERATURES WEDNESDAY NIGHT WILL BE TRICKY.
IT COULD ACTUALLY GET COLDER AHEAD OF THE FRONT IF WINDS CAN DROP OFF
TO LIGHT AND VARIABLE. VERTICAL MIXING IMMEDIATELY BEHIND THE FRONT
MAY KEEP LOCATIONS NEAR INTERSTATE 70 WARMER. BUT THIS IS SUBJECT
TO CHANGES IN FRONTAL TIMING. IN THE ABSENCE OF ARCTIC AIR, HIGH
TEMPERATURES SHOULD COOL DOWN TO NEAR SEASONAL VALUES, WITH HIGHS IN
THE UPPER 40S TO LOWER 50S THURSDAY AND UPPER 40S TO MID 50S FOR
FRIDAY.
BY SATURDAY AND SUNDAY, THE MODELS INDICATE UPPER-LEVEL TROUGHING
DEVELOPING ACROSS THE WESTERN UNITED STATES, THE SPEED AND AMPLITUDE
OF WHICH IS DIFFERENT DEPENDING ON THE MODEL. THIS SYSTEM WILL BRING
SOME ARCTIC AIR SOUTHWARD INTO THE NORTHERN OR EVEN CENTRAL PLAINS BY
SUNDAY. HOW FAST THIS ARCTIC FRONT MOVES THROUGH KANSAS IS
UNCERTAIN. BUT IT LOOKS LIKE TEMPERATURES WILL BE GETTING MUCH
COLDER SOMETIME BETWEEN SUNDAY AND TUESDAY (FEBRUARY 26-28TH). BUT
THERE WILL BE A VERY SHARP TEMPERATURE GRADIENT ALONG THE LEADING
EDGE OF THE ARCTIC AIR. SO SOME PLACES IN THE SOUTHERN PLAINS
(POSSIBLY INCLUDING SOUTHERN KANSAS) COULD GET VERY WARM SUNDAY OR
MONDAY (POSSIBLY 70S) BEFORE THE ARCTIC AIR ARRIVES. IT IS TOO EARLY
TO TELL IF ANY PRECIPITATION WILL ACCOMPANY THIS SYSTEM. AT THIS
POINT IT APPEARS THAT MOST OF THE PRECIPITATION WILL BE IN THE WARM
SECTOR AND WELL EAST OF HERE. HOWEVER, IF THE SYSTEM IS SLOWER AND
FURTHER SOUTH THAN WE CURRENTLY EXPECT, THEN SOME RAIN/SNOW WOULD BE
POSSIBLE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 531 PM CST MON FEB 20 2012
LOW IFR STATUS AND STEADY LIGHT SNOW CONTINUES ACROSS PORTIONS OF
SOUTHWEST KANSAS UNDER A COLD UPPER LOW AS IT SLOWLY MOVE EAST
ACROSS THE AREA LATE THIS AFTERNOON. SATELLITE LOOP SUPPORTS THE
18Z NAM BUFR SOUNDINGS THAT RAPID CLEARING WILL DEVELOP EARLY
TONIGHT AS THIS UPPER LOW MOVES ACROSS CENTRAL KANSAS. STRONG
NORTHWEST WINDS HOWEVER WILL CONTINUE FOR SEVERAL HOURS AFTER
SUNSET BASED ON THE TIGHT SURFACE PRESSURE GRADIENT AND 30-40KT
BOUNDARY LAYER WINDS. AFTER 03Z HOWEVER THESE WINDS WILL START TO
SUBSIDE AND BY 06Z WINDS ACROSS THE ENTIRE AREA ARE EXPECTED TO
FALL BACK TO AROUND 10KTS. VFR CONDITIONS AND 10KT WEST WINDS WILL
THEN CONTINUE THROUGH TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 22 58 30 71 / 90 0 0 0
GCK 20 56 28 70 / 0 0 0 0
EHA 21 57 33 70 / 0 0 0 0
LBL 21 58 30 72 / 0 0 0 0
HYS 25 56 30 69 / 10 0 0 0
P28 27 60 32 73 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 PM CST THIS EVENING FOR KSZ030-031-
043>046-062>066-077>081-088>090.
&&
$$
UPDATE...BURGERT
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS WICHITA KS
616 PM CST MON FEB 20 2012
.AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
FRONT WILL CONTINUE TO PUSH EAST WITH STORMS MOVING THROUGH KCNU AT
THE ONSET. SOME LIGHT RAIN AND/OR SNOW SHOWERS WILL BE POSSIBLE THIS
EVENING IN THE WRAP AROUND MOISTURE...MAINLY IN THE VICINITY OF
KRSL...ALTHOUGH NOT OUT OF THE QUESTION AT KSLN/KHUT. KICT IS
LIKELY A BIT FAR REMOVED FROM THE BETTER MOISTURE FOR PRECIPITATION.
RAPID CLEARING IS ANTICIPATED ONCE WAVE MOVES THROUGH. VERY GUSTY WINDS
ARE LIKELY BOTH AHEAD/BEHIND FRONT...WITH WINDS ONLY GRADUALLY
DIMINISHING OVERNIGHT AND DURING THE DAY ON TUESDAY. -HOWERTON
&&
.PREV DISCUSSION... /ISSUED 211 PM CST MON FEB 20 2012/
DISCUSSION...
FORECAST CONCERNS...CONVECTIVE TRENDS THRU EARLY EVENING AND
THEN TEMPERATURE ROLLER-COASTER THRU THE END OF THE WEEK.
THIS EVENING/OVERNIGHT
LATEST RUC AND HRRR WOULD SUGGEST 700-900 J/KG CAPE NEAR MAX
HEATING LATE THIS AFTERNOON JUST AHEAD OF SURFACE DRY-LINE/COLD
FRONT ACROSS SOUTH CENTRAL KANSAS. THIS IN COMBO WITH STRONG
DEEP LAYER SHEAR WILL SUPPORT STRONG TO A FEW SEVERE STORMS
INTO THE EARLY EVENING TRANSITIONING FROM PORTIONS OF CENTRAL
AND SOUTH CENTRAL KANSAS ACROSS THE SOUTHERN FLINT HILLS. SEE
LATEST HAZARDOUS WEATHER OUTLOOK AND SHORT TERM GRAPHICAST FOR
MORE DETAILS.
OTHERWISE...WINDS SHOULD REMAIN STOUT EVEN BEHIND THE FRONT
THIS EVENING...NEAR ADVISORY THRESHOLDS...SO 06Z/MIDNIGHT
EXPIRATION LOOKS FINE.
TUESDAY-FRIDAY
A RATHER SIGNIFICANT WARMING TREND IS EXPECTED THROUGH THE
MID-WEEK PERIOD WITHIN THE DEVELOPING MEAN WESTERLY FLOW
AHEAD OF THE NEXT UPPER TROF. THIS SUPPORTS THE GOING MAXS...
APPROACHING 70F IN MANY AREAS ON WEDNESDAY. THIS WILL BE
FOLLOWED BY A MODERATE STRENGTH COLD FRONT ON THURSDAY WITH
TEMPERATURES CLOSER TO SEASONAL CLIMO FOR THE END OF THE WEEK.
SATURDAY-MONDAY
A MORE ZONAL UPPER FLOW PATTERN TO START OUT THE WEEKEND
WITH TEMPERATURES AGAIN MODERATING ABOVE SEASONAL CLIMO. THE
MEDIUM RANGE MODELS GENERALLY SUPPORT MEAN TROUGHING ALOFT
ACROSS THE WESTERN CONUS LATE IN THE PERIOD...WITH THE ECMWF
A BIT DEEPER WITH THIS TROF BY MONDAY. THE MAIN CHALLENGE IS
THE TIMING OF THE ASSOCIATED COLD FRONTAL BOUNDARY SOUTH
ACROSS THE PLAINS...AND POTENTIAL OF SIGNIFICANT COOLING
BEHIND THIS FRONT. FOR NOW FORECAST CONSENSUS WAS TO TREND
COOLER BY MONDAY...THOUGH CONFIDENCE IS RATHER LOW ON THE
MAGNITUDE...WITH POTENTIAL FOR MUCH COLDER AIR. WILL ALSO
CARRY SLIGHT TO MODEST POPS ALONG/JUST BEHIND THIS SOUTHWARD
SAGGING FRONT FOR NOW WHICH CAN BE REFINED WITH LATER RUNS.
DARMOFAL
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MVFR CIGS WILL HANG TOUGH THROUGH AT LEAST MID-
AFTERNOON...ALTHOUGH SOME CLEARING FROM THE WEST IS EXPECTED AS A
STRONG COLD FRONT CONTINUES TO APPROACH FROM THE WEST. AHEAD OF
THE FRONT...VERY STRONG/GUSTY SOUTHERLY WINDS WILL PREVAIL.
ADDITIONALLY...SCATTERED THUNDERSTORMS SHOULD DEVELOP AROUND
20-21Z JUST WEST OF THE I-135 CORRIDOR. STORM MOTION WILL BE TO
THE NORTHEAST AT 50-60 MPH. A FEW STORMS WILL LIKELY PRODUCE SMALL
TO MODERATE SIZE HAIL UP TO DIME/QUARTER SIZE...ALONG WITH GUSTY
WINDS. THE STORMS WILL MOVE RAPIDLY NORTHEAST...WITH VERY STRONG
WEST/NORTHWEST WINDS DEVELOPING BY EARLY THIS EVENING BEHIND THE
COLD FRONT SWEEPING EAST ACROSS THE AREA...ALONG WITH MVFR TO LOW
VFR CIGS. CIGS AND WINDS WILL DISSIPATE BY LATE EVENING FROM WEST
TO EAST...CLEARING KCNU LAST.
KLEINSASSER
FIRE WEATHER...
STRONG WINDS WILL CONTINUE TO ELEVATE FIRE DANGER THROUGH THE
EVENING ACROSS MUCH OF THE AREA. DRIER AIR AND DIURNALLY GUSTY
WINDS MAY LEAD TO PERIODS OF ELEVATED FIRE DANGER DURING THE
AFTERNOON HOURS FROM TUESDAY THROUGH THURSDAY.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 28 57 33 68 / 20 0 0 0
HUTCHINSON 27 57 32 69 / 20 0 0 0
NEWTON 29 56 34 68 / 30 0 0 0
ELDORADO 30 56 34 67 / 30 0 0 0
WINFIELD-KWLD 29 58 33 69 / 20 0 0 0
RUSSELL 26 56 32 69 / 40 0 0 0
GREAT BEND 26 56 32 69 / 30 0 0 0
SALINA 28 57 33 69 / 50 0 0 0
MCPHERSON 28 57 33 68 / 30 0 0 0
COFFEYVILLE 33 59 34 69 / 80 0 0 0
CHANUTE 32 57 34 67 / 80 0 0 0
IOLA 32 56 34 66 / 80 0 0 0
PARSONS-KPPF 33 58 34 68 / 80 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR KSZ032-033-047>053-
067>070-082-083-091>094-098.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
544 PM CST MON FEB 20 2012
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 235 PM CST MON FEB 20 2012
FORECAST CONCERNS ARE THE SNOW AND HIGH WINDS LATE THIS AFTERNOON
INTO EARLY EVENING. THIS MORNINGS UA ANALYSIS SHOWED A STRONG
UPPER TROUGH ALONG THE EASTERN SLOPES OF THE ROCKIES WITH A CLOSED
CIRCULATION SHOWING UP OVER NORTHEAST COLORADO. THIS FEATURE HAS BEEN
MOVING STEADILY EAST THROUGH WESTERN KANSAS AND THE OK/TX PANHANDLES
THIS AFTERNOON. RUC ANALYSIS SHOWED A FAIRLY INTENSE MID LEVEL
VORT MAX ACROSS THE AREA WITH STRONG PVA AND MID LEVEL UVV OCCURRING
OVER SOUTHWEST KANSAS. THIS LINES UP WELL WITH AN AREA OF LIGHT
TO MODERATE SNOW WHICH HAS BEEN TRANSLATING EAST THROUGH SOUTHWEST
KANSAS TODAY.
THE AREAS OF RAIN AND SNOW SHOULD CONTINUE TO WORK EASTWARD ACROSS
SOUTHWEST AND TOWARD CENTRAL KANSAS THROUGH THE LATE AFTERNOON
HOURS BUT SHOULD BEGIN TO DIMINISH RAPIDLY TOWARD SUNSET AS THE
TROUGH AXIS MOVES EAST OF THE AREA.
HIGH WINDS HAVE BEEN SLOW TO MATERIALIZE ACROSS SOUTHWEST KANSAS
THIS AFTERNOON PARTLY DUE TO THE WIDESPREAD CLOUD COVER AND
REDUCED MIXING. AM STILL CONCERNED THAT WE COULD SEE A WINDOW OF
OPPORTUNITY AS THE GRADIENT INCREASES ON THE BACKSIDE OF THE LOWER
ATMOSPHERIC TROUGH AXIS. RUC MODEL SOUNDINGS THROUGHOUT THE DAY
HAVE BEEN SHOWING 50-60 KNOT WINDS DEVELOPING IN THE 850-875 MB
LAYER THROUGH THE 21Z-01Z TIME PERIOD. WILL KEEP THE CURRENT
HEADLINES IN PLACE THROUGH THE EARLY EVENING HOURS.
THE UPPER LEVEL SHORTWAVE TROUGH WILL MOVE RAPIDLY EAST OUT OF THE
PLAINS TONIGHT WITH WESTERLY FLOW OVER THE HIGH PLAINS. ANOTHER
BROAD SHORTWAVE TROUGH IS FORECAST TO MOVE SOUTHEAST OVER THE
CENTRAL CONUS DURING THE DAY TUESDAY. ONLY SOME SCATTERED HIGH
CLOUDINESS IS EXPECTED WITH THE SHORTWAVE. LOW LEVEL DOWNSLOPE
FLOW SHOULD HELP BOOST TEMPERATURES INTO THE 55 TO 60 DEGREE RANGE
FOR AFTERNOON HIGHS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 543 PM CST MON FEB 20 2012
NORTHWESTERLY MID TO HIGH LEVEL FLOW WILL DEVELOP BY TUESDAY NIGHT
AND PERSIST THROUGH FRIDAY. THIS IS USUALLY A DRY REGIME FOR
WESTERN KANSAS AS THE GULF OF MEXICO TENDS TO BE SHUT OFF.
DOWNSLOPE WESTERLY LOW-LEVEL FLOW WILL DEVELOP TUESDAY NIGHT WITH
850MB TEMPERATURES RISING TO BETWEEN 6 AND 9C. HOWEVER, GIVEN THE
EXPECTED CLEAR SKIES AND ONLY 5 TO 10 KT WINDS, TEMPERATURES WILL
PROBABLY STILL DROP INTO THE LOWER 30S. WEDNESDAY WILL BE A WARM DAY
WITH WESTERLY DOWNSLOPE FLOW PERSISTING AS SURFACE LOW PRESSURE DEVELOPS
ACROSS NEBRASKA AHEAD OF A SHORTWAVE TROUGH. IN THESE SITUATIONS IN
LATE WINTER AND EARLY SPRING TEMPERATURES TYPICALLY GET WARMER THAN
ANY OF THE MODELS INDICATE. GIVEN THE EXPECTED WESTERLY SURFACE
WINDS AT 10 TO 20 KTS, A DEEP, DRY ADIABATIC LAYER WILL DEVELOP.
TEMPERATURES OUGHT TO EASILY REACH INTO THE UPPER 60S TO LOWER 70S.
AS IS TYPICAL IN DOWNSLOPE REGIMES WHEN THE WEST WINDS PROGRESS ALL
THE WAY INTO CENTRAL KANSAS, THE VERY WARMEST READINGS MAY BE ON THE
LOWER TERRAIN OF SOUTHERN CLARK, COMANCHE AND BARBER COUNTIES
(ELEVATIONS 1500-2000FT) AS OPPOSED TO DODGE CITY (2600FT), GARDEN
CITY (2900FT) AND SYRACUSE (3300FT).
COOL SURFACE HIGH PRESSURE WILL MOVE INTO WESTERN KANSAS LATE
WEDNESDAY NIGHT AND THURSDAY IN THE WAKE OF THE AFOREMENTIONED
SHORTWAVE TROUGH. LOW TEMPERATURES WEDNESDAY NIGHT WILL BE TRICKY.
IT COULD ACTUALLY GET COLDER AHEAD OF THE FRONT IF WINDS CAN DROP OFF
TO LIGHT AND VARIABLE. VERTICAL MIXING IMMEDIATELY BEHIND THE FRONT
MAY KEEP LOCATIONS NEAR INTERSTATE 70 WARMER. BUT THIS IS SUBJECT
TO CHANGES IN FRONTAL TIMING. IN THE ABSENCE OF ARCTIC AIR, HIGH
TEMPERATURES SHOULD COOL DOWN TO NEAR SEASONAL VALUES, WITH HIGHS IN
THE UPPER 40S TO LOWER 50S THURSDAY AND UPPER 40S TO MID 50S FOR
FRIDAY.
BY SATURDAY AND SUNDAY, THE MODELS INDICATE UPPER-LEVEL TROUGHING
DEVELOPING ACROSS THE WESTERN UNITED STATES, THE SPEED AND AMPLITUDE
OF WHICH IS DIFFERENT DEPENDING ON THE MODEL. THIS SYSTEM WILL BRING
SOME ARCTIC AIR SOUTHWARD INTO THE NORTHERN OR EVEN CENTRAL PLAINS BY
SUNDAY. HOW FAST THIS ARCTIC FRONT MOVES THROUGH KANSAS IS
UNCERTAIN. BUT IT LOOKS LIKE TEMPERATURES WILL BE GETTING MUCH
COLDER SOMETIME BETWEEN SUNDAY AND TUESDAY (FEBRUARY 26-28TH). BUT
THERE WILL BE A VERY SHARP TEMPERATURE GRADIENT ALONG THE LEADING
EDGE OF THE ARCTIC AIR. SO SOME PLACES IN THE SOUTHERN PLAINS
(POSSIBLY INCLUDING SOUTHERN KANSAS) COULD GET VERY WARM SUNDAY OR
MONDAY (POSSIBLY 70S) BEFORE THE ARCTIC AIR ARRIVES. IT IS TOO EARLY
TO TELL IF ANY PRECIPITATION WILL ACCOMPANY THIS SYSTEM. AT THIS
POINT IT APPEARS THAT MOST OF THE PRECIPITATION WILL BE IN THE WARM
SECTOR AND WELL EAST OF HERE. HOWEVER, IF THE SYSTEM IS SLOWER AND
FURTHER SOUTH THAN WE CURRENTLY EXPECT, THEN SOME RAIN/SNOW WOULD BE
POSSIBLE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 531 PM CST MON FEB 20 2012
LOW IFR STATUS AND STEADY LIGHT SNOW CONTINUES ACROSS PORTIONS OF
SOUTHWEST KANSAS UNDER A COLD UPPER LOW AS IT SLOWLY MOVE EAST
ACROSS THE AREA LATE THIS AFTERNOON. SATELLITE LOOP SUPPORTS THE
18Z NAM BUFR SOUNDINGS THAT RAPID CLEARING WILL DEVELOP EARLY
TONIGHT AS THIS UPPER LOW MOVES ACROSS CENTRAL KANSAS. STRONG
NORTHWEST WINDS HOWEVER WILL CONTINUE FOR SEVERAL HOURS AFTER
SUNSET BASED ON THE TIGHT SURFACE PRESSURE GRADIENT AND 30-40KT
BOUNDARY LAYER WINDS. AFTER 03Z HOWEVER THESE WINDS WILL START TO
SUBSIDE AND BY 06Z WINDS ACROSS THE ENTIRE AREA ARE EXPECTED TO
FALL BACK TO AROUND 10KTS. VFR CONDITIONS AND 10KT WEST WINDS WILL
THEN CONTINUE THROUGH TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 22 58 30 71 / 90 0 0 0
GCK 20 56 28 70 / 0 0 0 0
EHA 21 57 33 70 / 0 0 0 0
LBL 21 58 30 72 / 0 0 0 0
HYS 25 56 30 69 / 10 0 0 0
P28 27 60 32 73 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 7 PM CST /6 PM MST/ THIS EVENING FOR
KSZ030-043>045-061>064-074>078-084>088.
WIND ADVISORY UNTIL 10 PM CST THIS EVENING FOR KSZ031-046-065-
066-079>081-089-090.
&&
$$
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
530 PM CST MON FEB 20 2012
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 235 PM CST MON FEB 20 2012
FORECAST CONCERNS ARE THE SNOW AND HIGH WINDS LATE THIS AFTERNOON
INTO EARLY EVENING. THIS MORNINGS UA ANALYSIS SHOWED A STRONG
UPPER TROUGH ALONG THE EASTERN SLOPES OF THE ROCKIES WITH A CLOSED
CIRCULATION SHOWING UP OVER NORTHEAST COLORADO. THIS FEATURE HAS BEEN
MOVING STEADILY EAST THROUGH WESTERN KANSAS AND THE OK/TX PANHANDLES
THIS AFTERNOON. RUC ANALYSIS SHOWED A FAIRLY INTENSE MID LEVEL
VORT MAX ACROSS THE AREA WITH STRONG PVA AND MID LEVEL UVV OCCURRING
OVER SOUTHWEST KANSAS. THIS LINES UP WELL WITH AN AREA OF LIGHT
TO MODERATE SNOW WHICH HAS BEEN TRANSLATING EAST THROUGH SOUTHWEST
KANSAS TODAY.
THE AREAS OF RAIN AND SNOW SHOULD CONTINUE TO WORK EASTWARD ACROSS
SOUTHWEST AND TOWARD CENTRAL KANSAS THROUGH THE LATE AFTERNOON
HOURS BUT SHOULD BEGIN TO DIMINISH RAPIDLY TOWARD SUNSET AS THE
TROUGH AXIS MOVES EAST OF THE AREA.
HIGH WINDS HAVE BEEN SLOW TO MATERIALIZE ACROSS SOUTHWEST KANSAS
THIS AFTERNOON PARTLY DUE TO THE WIDESPREAD CLOUD COVER AND
REDUCED MIXING. AM STILL CONCERNED THAT WE COULD SEE A WINDOW OF
OPPORTUNITY AS THE GRADIENT INCREASES ON THE BACKSIDE OF THE LOWER
ATMOSPHERIC TROUGH AXIS. RUC MODEL SOUNDINGS THROUGHOUT THE DAY
HAVE BEEN SHOWING 50-60 KNOT WINDS DEVELOPING IN THE 850-875 MB
LAYER THROUGH THE 21Z-01Z TIME PERIOD. WILL KEEP THE CURRENT
HEADLINES IN PLACE THROUGH THE EARLY EVENING HOURS.
THE UPPER LEVEL SHORTWAVE TROUGH WILL MOVE RAPIDLY EAST OUT OF THE
PLAINS TONIGHT WITH WESTERLY FLOW OVER THE HIGH PLAINS. ANOTHER
BROAD SHORTWAVE TROUGH IS FORECAST TO MOVE SOUTHEAST OVER THE
CENTRAL CONUS DURING THE DAY TUESDAY. ONLY SOME SCATTERED HIGH
CLOUDINESS IS EXPECTED WITH THE SHORTWAVE. LOW LEVEL DOWNSLOPE
FLOW SHOULD HELP BOOST TEMPERATURES INTO THE 55 TO 60 DEGREE RANGE
FOR AFTERNOON HIGHS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 351 AM CST MON FEB 20 2012
MEDIUM RANGE MODELS INDICATE AN UPPER LEVEL TROUGH OF LOW PRESSURE
IN THE FAR INTERMOUNTAIN WEST DROPPING SOUTH INTO THE BAJA
CALIFORNIA REGION EARLY IN THE PERIOD TUESDAY. MEANWHILE, A WEST TO
NORTHWESTERLY FLOW ALOFT WILL PREVAIL ACROSS THE WESTERN HIGH PLAINS
DURING THE FIRST COUPLE DAYS OF THE PERIOD ALONG WITH A WESTERLY
DOWNSLOPE REGIME PERSISTING NEAR THE SURFACE HELPING TO DRY OUT THE
LOWER LEVELS. AS A RESULT, DRY CONDITIONS ARE LIKELY THROUGH AT LEAST
WEDNESDAY NIGHT. THE UPPER LEVEL TROUGH IN THE DESERT SOUTHWEST IS
THEN PROJECTED TO TRACK EASTWARD INTO THE SOUTH PLAINS OF TEXAS BY
THURSDAY JUST AS A SECONDARY UPPER LEVEL SHORTWAVE DROPS SOUTHEAST
OUT OF CANADA INTO THE NORTHERN PLAINS. THE NORTHERN WAVE WILL HELP
USHER A COLD FRONT SOUTH INTO WESTERN KANSAS SOMETIME LATE WEDNESDAY
NIGHT INTO EARLY THURSDAY. HOWEVER, VERY LITTLE IS EXPECTED IN
REGARDS TO PRECIP WITH THIS FRONTAL PASSAGE WITH A LACK OF LOW LEVEL
MOISTURE REMAINING A FACTOR.
TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL TUESDAY AS A WEAK LEE
SIDE TROUGH INFLUENCES A WESTERLY DOWNSLOPE FLOW ACROSS WESTERN
KANSAS. THE NAM, GFS, AND ECMWF SHOW H85 TEMPERATURES RANGING FROM
AROUND 5C ACROSS CENTRAL KANSAS TO NEAR 8C ALONG THE COLORADO
BORDER. LOOK FOR HIGHS WELL UP INTO THE 50S(F) TUESDAY AFTERNOON
WITH NEAR 60F POSSIBLE IN SOUTH CENTRAL KANSAS. TEMPERATURES WILL
CLIMB GOING INTO WEDNESDAY AS THE WESTERLY DOWNSLOPE COMPONENT NEAR
THE SURFACE CONTINUES ACROSS WESTERN KANSAS. TEMPERATURES AT H85
WILL WARM TO AROUND 12C ACROSS CENTRAL KANSAS TO NEAR 15C IN EXTREME
SOUTHWEST KANSAS. EXPECT WIDESPREAD 60S(F) WEDNESDAY WITH NEAR
70F POSSIBLE IN SOME LOCATIONS. WILL NEED TO RAISE HIGHS ON
WEDNESDAY BY AT LEAST 3 TO 5 DEGREES ACROSS THE ENTIRE FORECAST
AREA. COOLER TEMPERATURES ARE THEN LIKELY THURSDAY INTO FRIDAY IN
WAKE OF THE PROJECTED FRONTAL PASSAGE BY EARLY THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 531 PM CST MON FEB 20 2012
LOW IFR STATUS AND STEADY LIGHT SNOW CONTINUES ACROSS PORTIONS OF
SOUTHWEST KANSAS UNDER A COLD UPPER LOW AS IT SLOWLY MOVE EAST
ACROSS THE AREA LATE THIS AFTERNOON. SATELLITE LOOP SUPPORTS THE
18Z NAM BUFR SOUNDINGS THAT RAPID CLEARING WILL DEVELOP EARLY
TONIGHT AS THIS UPPER LOW MOVES ACROSS CENTRAL KANSAS. STRONG
NORTHWEST WINDS HOWEVER WILL CONTINUE FOR SEVERAL HOURS AFTER
SUNSET BASED ON THE TIGHT SURFACE PRESSURE GRADIENT AND 30-40KT
BOUNDARY LAYER WINDS. AFTER 03Z HOWEVER THESE WINDS WILL START TO
SUBSIDE AND BY 06Z WINDS ACROSS THE ENTIRE AREA ARE EXPECTED TO
FALL BACK TO AROUND 10KTS. VFR CONDITIONS AND 10KT WEST WINDS WILL
THEN CONTINUE THROUGH TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 22 58 30 71 / 70 0 0 0
GCK 20 56 28 70 / 30 0 0 0
EHA 21 57 33 70 / 0 0 0 0
LBL 21 58 30 72 / 0 0 0 0
HYS 25 56 30 69 / 40 0 0 0
P28 27 60 32 73 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 7 PM CST /6 PM MST/ THIS EVENING FOR
KSZ030-043>045-061>064-074>078-084>088.
WIND ADVISORY UNTIL 10 PM CST THIS EVENING FOR KSZ031-046-065-
066-079>081-089-090.
&&
$$
SHORT TERM...GERARD
LONG TERM....JJOHNSON
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1134 AM CST SUN FEB 19 2012
...UPDATE TO AVIATION...
.DISCUSSION...
SHORT RANGE FORECAST (TODAY AND MONDAY)...
EARLY MORNING 11 TO 3.9 MICRON SATELLITE IMAGERY INDICATES THAT ALL
OF NORTHEAST KANSAS REMAINS UNDER MOSTLY CLEAR SKIES. 08Z WATER
VAPOR IMAGERY AND THE ASSOCIATED RUC UPPER AIR ANALYSIS SHOWS A
WEAK UPPER TROUGH MOVING EASTWARD INTO NORTHERN MISSOURI. THIS
TROUGH WILL NOT HAVE MUCH AFFECT ON THE REGION THIS MORNING AS IT
EXITS TO THE EAST. ALSO TO THE WEST...THE NEXT UPPER WAVE IS
BEGINNING TO DIG INTO THE INTERIOR WESTERN US AND SHOULD BE CROSSING
THE GREAT DIVIDE ON SUNDAY NIGHT. THIS WESTERN TROUGH WILL BE THE
ONE TO WATCH AS WE HEAD INTO NEXT WEEK. BETWEEN THE TWO UPPER
TROUGHS IS A SHORTWAVE RIDGE WHICH WILL MOVE OVER THE AREA FOR
SUNDAY. SOUTHERLY WINDS WILL PICK UP THROUGHOUT THE DAY ON
SUNDAY...WHICH IN COMBINATION WITH THE UPPER RIDGE SHOULD ALLOW TEMPS
TO WARM UP A BIT FROM SATURDAY. EXPECT TEMPS TO RISE INTO THE
LOWER 50S TODAY AS THE LOWER ATMOSPHERE SHOULD BE ABLE TO MIX TO
AROUND 850 MB ON SUNDAY.
SOUTHERLY WINDS WILL PERSIST THROUGH THE NIGHT AS THE SURFACE WAVE
DEEPENS AS IT COMES OFF THE HIGH PLAINS. THE LASTING SOUTHERLY
FETCH SHOULD ALLOW DECENT MOISTURE (FOR THIS TIME OF YEAR) TO
RETURN INTO THE CENTRAL PLAINS. MODELS FOR A COUPLE DAYS HAVE
HINTED AT LOWER TO MID 40 DEWPOINTS REACHING INTO NORTHEAST KANSAS
IN ADVANCE OF THE NEXT TROUGH. TAKING A CUE FROM THE 00Z AND 06Z
NAM HAVE INTRODUCED SOME THUNDER TO THE GOING FORECAST AS MODELS
HAVE NOW INDICATED ENOUGH MOISTURE INFLUX AND STEEP ENOUGH MID
LEVEL LAPSE RATES TO GENERATE UP TO 500-700 J/KG OF MUCAPE DURING
THE DAY ON MONDAY. WITH THAT MUCH INSTABILITY IT SEEMS ALMOST
LIKELY AT THIS POINT THAT THUNDERSTORMS WILL BE EMBEDDED WITHIN
THE MONDAY RAIN SHIELD. ONCE THE MAIN UPPER WAVE ENTERS THE
CENTRAL PLAINS ON MONDAY AFTERNOON/EVENING IT WOULD PROVIDE ENOUGH
LIFT TO KICK OFF RAIN SHOWERS ACROSS THE ENTIRE FORECAST AREA.
SURFACE AND LOW LEVEL WINDS SHOULD BE BACKED ON MONDAY AFTERNOON
WHICH IN CONJUNCTION WITH S-SWLY FLOW IN THE LOW TO MID LEVELS
WILL ALLOW FOR SOME TURNING IN THE ATMOSPHERE. WITH 0-6 SHEAR
EXPECTED TO BE ON THE ORDER OF 40 TO 50 KNOTS...THE COMBINATION OF
INSTABILITY WITH SHEAR MAY ALLOW FOR SOME ISOLATED STRONG
THUNDERSTORMS WHICH WOULD ALSO BRING AN ISOLATED HAIL THREAT FOR
MONDAY. ONCE THE SUN SETS ON MONDAY NIGHT THE INSTABILITY SHOULD
WANE RAPIDLY...SO ANY LINGERING SHOWERS BEYOND 8 PM TO 9 PM ON
MONDAY SHOULD BE LIGHT STRATIFORM RAIN AS OPPOSED TO
THUNDERSTORMS. EXPECT PRECIP TO EXIT THE AREA COMPLETELY BY AROUND
MIDNIGHT ON TUESDAY MORNING.
MID RANGE AND EXTENDED FORECAST (TUESDAY THROUGH SATURDAY)...
A RATHER MILD AND UNSEASONABLY WARM WEEK IS ON TAP ONCE THE RAIN
SHOWERS EXIT ON TUESDAY MORNING. A RATHER PRONOUNCED DOWN SLOPE
COMPONENT TO THE WINDS PRESENTS ITSELF FOR TUESDAY AND WEDNESDAY
WHICH SHOULD AID IN WARMING TEMPS FOR THE MID TO LATE WEEK TIME
PERIOD. BROAD UPPER WAVE THEN SLIDES SOUTHEASTWARD LATE IN THE
WEEK...WHICH WILL BRING AN ISOLATED CHANCE FOR SOME PRECIP IN THE
FAR NORTHEASTERN CORNER OF THE STATE. SURFACE HIGH THEN DROPS
SOUTHWARD ON THURSDAY INTO FRIDAY...WHICH WILL BRING A COOLING
TREND FOR THE LATE HALF OF THE WEEK. SINCE THE AIR MASS DOES NOT
LOOK TO BE ARCTIC IN NATURE EXPECT TEMPERATURES TO REMAIN AT OR
SLIGHTLY ABOVE SEASONAL NORMALS.
JL
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
.AVIATION...
VFR EXPECTED THROUGH 09Z AT THE TERMINAL SITES. MVFR CIGS ARE
EXPECTED TO MOVE INTO THE THE MHK TERMINAL BY 12Z MONDAY. VFR
EXPECTED AT TOP AND FOE THROUGH THE ENTIRE PERIOD. WINDS WILL
INCREASE FROM THE SOUTHEAST TO SOUTH BY 13Z WITH WINDS NEAR 18KTS
WITH GUSTS TO 28 KTS BY END OF PERIOD POSSIBLE. SHRA WILL DEVELOP
AFTER 15Z AND ADDED VCSH TO MHK TAF ATTM.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
731 AM CST SUN FEB 19 2012
.UPDATE...
ISSUED AT 716 AM CST SUN FEB 19 2012
THE STRATUS DECK IS VERY EXTENSIVE ACROSS THE HIGH PLAINS THIS MORNING.
THE 00 AND 06 NAM DID NOT HANDLE THE EVOLUTION OF THE STRATUS VERY
WELL AT ALL. THE 12Z SOUNDING FROM DODGE CITY SHOWS A NEARLY SATURATED
LAYER FROM 1400 FT AGL UP TO AROUND 3000 FT AGL, WHILE THE NAM WAS
DRY IN THIS LAYER AND ONLY INDICATED SKIN DEEP MOISTURE. THE RUC
IS DOING A LITTLE BETTER JOB AND RUC SOUNDINGS INDICATE LOW CLOUDS
HANGING ON THROUGH MID-DAY AT GCK/DDC. THUS, MAXIMUM TEMPERATURES
WERE LOWERED A FEW DEGREES ALONG A CORRIDOR FROM DODGE CITY TO
DIGHTON AND GARDEN CITY AND CLEARING WAS POSTPONED IN THE GRIDS
UNTIL LATE MORNING AND EARLY AFTERNOON.
AFTER THE LOSS OF DAYTIME HEATING, EXTENSIVE LOW CLOUD COVER
SHOULD REDEVELOP BETWEEN 02 AND 05Z. THE NAM HOLDS OFF ON STRATUS
DEVELOPMENT UNTIL 09-10Z AND THIS IS PROBABLY IN ERROR. SKY COVER
GRIDS WERE UPDATED TO REFLECT THIS THINKING.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 320 AM CST SUN FEB 19 2012
THE MAIN FORECAST CHALLENGES ARE CHANCES FOR ISOLATED THUNDERSTORMS
LATE TONIGHT AND STRONG WINDS THIS AFTERNOON AND OVERNIGHT.
A STRONG UPPER LEVEL TROUGH WILL MOVE FROM THE WESTERN CONUS AND
INTO THE INTERMOUNTAIN WEST TODAY THEN INTO THE ROCKIES TONIGHT.
THIS SYSTEM WILL PUSH A WARM FRONT ACROSS FAR WESTERN KANSAS TODAY
AND THROUGH CENTRAL KANSAS TONIGHT. AS THE TROUGH APPROACHES THE
PRESSURES WILL DROP AS A LOW DEVELOPS IN EASTERN COLORADO. THIS WILL
CAUSE A STRONG PRESSURE GRADIENT ACROSS WESTERN KANSAS TODAY AND
SOUTH WINDS COULD BE CLOSE TO WIND ADVISORY. HOWEVER SOME MID TO
HIGH LEVEL CLOUDINESS MAY OFFSET GOOD MIXING. FOR NOW WILL KEEP
WINDS FROM THE SOUTH AT 20 TO 30 MPH AND GUSTY. A STRONG INVERSION
IS ALSO FORECAST AT AROUND 750MB THAT COULD TRAP SOME OF THE CURRENT
STRATUS. IF MORE SUN COMES OUT WINDS COULD BE INTO ADVISORY LEVEL.
HIGHS TODAY WILL BE NEAR 60 IN THE FAR WEST AROUND SYRACUSE AND
ELKHART TO THE LOW 50S EAST FROM HAYS TO MEDICINE LODGE.
TONIGHT A LOW LEVEL JET IS FORECAST AS AN UPPER LEVEL DRY SLOT MOVES
INTO WESTERN KANSAS. THE BEST MOISTURE AND LIFT LOOK TO BE FROM
WAKEENEY TO DODGE CITY AND HAYS WITH A DRY LINE MOVING IN FROM THE
WEST LATE TONIGHT. FORECAST SOUNDINGS SHOW SOME ELEVATED CAPE AFTER
MIDNIGHT SO KEPT 20 TO 30 POPS GOING AND ADDED SOME ISOLATED
THUNDER. SURFACE WINDS SHOULD ALSO STAY UP AT 20 TO 30 MPH OVERNIGHT
WITH MILD OVERNIGHT LOWS. WILL KEEP CURRENT LOWS FROM THE LOW TO MID
30S FAR WEST TO AROUND 40 EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 339 AM CST SUN FEB 19 2012
A STRONG SHORTWAVE TROUGH MOVING INTO THE NORTHWESTERN UNITED
STATES THIS AFTERNOON WILL RAPIDLY PROGRESS ACROSS THE CENTRAL
ROCKIES BY SUNDAY NIGHT AND THEN ACROSS KANSAS BY MONDAY
AFTERNOON. THE ECMWF/UKMET AND GEM WERE NOT CLOSED OFF WHILE THE
NAM/GFS SHOW A CLOSED UPPER-LOW OVER KANSAS BY MONDAY AFTERNOON.
HAVING BEEN SHUNTED INTO THE GULF OF MEXICO BY THE PREVIOUS STRONG
UPPER-LEVEL SYSTEM, RICH LOW-LEVEL MOISTURE (50S AND 60S SURFACE
DEWPOINTS) WILL NOT RETURN INTO THE SOUTHERN PLAINS AHEAD OF THIS
SYSTEM. DESPITE THIS, THE NAM/GFS DO NOT MAKE A CLEAN SWEEP OF THE
MARGINAL 40-45F DEWPOINTS INTO THE GULF OF MEXICO. IN FACT, THE
NAM SHOWS A NEARLY SATURATED LAYER BETWEEN THE SURFACE AND 1
KILOMETER INTO SOUTHWEST KANSAS BY 12Z MONDAY, SO WIDESPREAD, LOW
STRATUS IS LIKELY IN THE MORNING MONDAY. AS THE UPPER SYSTEM
TRAVERSES KANSAS MONDAY, THIS LOW- LEVEL MOIST AXIS IS EXPECTED TO
SHIFT INTO EASTERN KANSAS. THE 500MB COLD POOL WITH THIS TROUGH
WILL BE VERY IMPRESSIVE, WITH TEMPERATURES AS LOW AS -29C. SURFACE
BASED THUNDERSTORMS WITH POSSIBLE SEVERE WEATHER SHOULD STAY TO
OUR EAST AND SOUTHEAST MONDAY AFTERNOON. BUT INCREASING MID-LEVEL
RELATIVE HUMIDITY AND VERY COLD MID-LEVEL TEMPERATURES COULD
RESULT IN SHOWERS ACROSS SOUTHWEST KANSAS. ALL THE PRECIPITATION
OUGHT TO BE IN LIQUID FORM DUE TO WARM BOUNDARY LAYER
TEMPERATURES, ESPECIALLY IF THE LESS CLOSED OFF SOLUTION THAT WE
FAVOR ACTUALLY VERIFIES. THE ASSOCIATED COLD FRONT WILL PASS
ACROSS WESTERN KANSAS LATE MONDAY AFTERNOON AND MONDAY EVENING. 25
TO 30 KT WINDS ARE LIKELY BEHIND THE FRONT MONDAY AFTERNOON AND
EVENING AND A WIND ADVISORY WILL LIKELY BE NEEDED.
AFTER THE AFOREMENTIONED SYSTEM PASSES, THE MID TO UPPER-LEVEL FLOW
WILL BECOME NORTHWESTERLY, WITH UPPER-LEVEL RIDGING NEAR THE WEST
COAST, AND LOW AMPLITUDE TROUGHING OVER THE GREAT LAKES AND EASTERN
UNITED STATES. OF COURSE, THIS IS A DRY PATTERN FOR WESTERN KANSAS
AS ANY LOW-LEVEL GULF MOISTURE SHOULD BE DIRECTED WELL TO OUR EAST.
TEMPERATURES WILL BE A FEW DEGREES ABOVE CLIMATOLOGY BEHIND THE
PACIFIC COLD FRONT ON TUESDAY AS LOW-LEVEL WINDS WILL BE DOWNSLOPE
FROM THE WEST. BY WEDNESDAY, THE GFS/ECMWF SUGGEST CONTINUING
LOW-LEVEL DOWNSLOPE FLOW FROM THE WEST AS A SHORTWAVE TROUGH PASSES
ACROSS THE NORTHERN PLAINS. TEMPERATURES COULD REACH INTO THE MID
60S AHEAD OF THE ASSOCIATED COLD FRONT. ONCE THAT SHORTWAVE TROUGH
PASSES FURTHER EAST, THE COLD FRONT SHOULD PROGRESS THROUGH WESTERN
KANSAS BY WEDNESDAY NIGHT, LEADING TO FAIRLY SEASONABLE TEMPERATURES
FOR THURSDAY AND FRIDAY.
THE ECMWF AND GEM CONTINUE TO BE INCONSISTENT WITH THE AMPLITUDE
AND LOCATION OF AN UPPER-LEVEL TROUGH OVER THE WESTERN UNITED STATES
BY FEBRUARY 26TH. BUT IF THE DEEPER SOLUTION VERIFIES, THEN
PRECIPITATION WOULD BE POSSIBLE IN PARTS OF THE PLAINS REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 606 AM CST SUN FEB 19 2012
LOW STRATUS HAS ENVELOPED THE TAF SITES. THE NAM IS DOING A BAD JOB
WITH THE LOW CLOUD DECK. BELIEVE THE STRATUS WILL BE MUCH SLOWER
TO BURN OFF, WITH IFR OR LOW MVFR CIGS PERSISTING THROUGH 16Z. EXPECT
IFR CIGS TO RETURN BETWEEN 03 AND 06Z TONIGHT AS THE BOUNDARY
LAYER COOLS AND A LOW LEVEL JET SETS UP.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 49 39 55 26 / 0 20 20 0
GCK 50 36 50 24 / 0 10 20 0
EHA 58 35 49 22 / 0 10 20 0
LBL 54 38 52 26 / 0 10 20 0
HYS 50 38 53 26 / 0 30 30 20
P28 52 41 58 28 / 0 30 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...FINCH
SHORT TERM...KRUSE
LONG TERM....FINCH
AVIATION...FINCH
AREA FORECAST DISCUSSION
NWS TOPEKA KS
555 AM CST SUN FEB 19 2012
...UPDATE TO AVIATION...
&&
.AVIATION...
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WINDS BECOME SOUTHEAST
LATE THIS MORNING AND SLOWLY INCREASE BY MID DAY. EXPECT FURTHER
INCREASE IN WIND SPEED AND CLOUD COVER TOWARD END OF THE TAF
PERIOD BUT TOO FAR OUT /AFTER 09Z/ TO INCLUDE AT THIS TIME. 67
&&
.PREV DISCUSSION...
/ISSUED 346 AM CST SUN FEB 19 2012/
SHORT RANGE FORECAST (TODAY AND MONDAY)...
EARLY MORNING 11 TO 3.9 MICRON SATELLITE IMAGERY INDICATES THAT ALL
OF NORTHEAST KANSAS REMAINS UNDER MOSTLY CLEAR SKIES. 08Z WATER
VAPOR IMAGERY AND THE ASSOCIATED RUC UPPER AIR ANALYSIS SHOWS A
WEAK UPPER TROUGH MOVING EASTWARD INTO NORTHERN MISSOURI. THIS
TROUGH WILL NOT HAVE MUCH AFFECT ON THE REGION THIS MORNING AS IT
EXITS TO THE EAST. ALSO TO THE WEST...THE NEXT UPPER WAVE IS
BEGINNING TO DIG INTO THE INTERIOR WESTERN US AND SHOULD BE CROSSING
THE GREAT DIVIDE ON SUNDAY NIGHT. THIS WESTERN TROUGH WILL BE THE
ONE TO WATCH AS WE HEAD INTO NEXT WEEK. BETWEEN THE TWO UPPER
TROUGHS IS A SHORTWAVE RIDGE WHICH WILL MOVE OVER THE AREA FOR
SUNDAY. SOUTHERLY WINDS WILL PICK UP THROUGHOUT THE DAY ON
SUNDAY...WHICH IN COMBINATION WITH THE UPPER RIDGE SHOULD ALLOW TEMPS
TO WARM UP A BIT FROM SATURDAY. EXPECT TEMPS TO RISE INTO THE
LOWER 50S TODAY AS THE LOWER ATMOSPHERE SHOULD BE ABLE TO MIX TO
AROUND 850 MB ON SUNDAY.
SOUTHERLY WINDS WILL PERSIST THROUGH THE NIGHT AS THE SURFACE WAVE
DEEPENS AS IT COMES OFF THE HIGH PLAINS. THE LASTING SOUTHERLY
FETCH SHOULD ALLOW DECENT MOISTURE (FOR THIS TIME OF YEAR) TO
RETURN INTO THE CENTRAL PLAINS. MODELS FOR A COUPLE DAYS HAVE
HINTED AT LOWER TO MID 40 DEWPOINTS REACHING INTO NORTHEAST KANSAS
IN ADVANCE OF THE NEXT TROUGH. TAKING A CUE FROM THE 00Z AND 06Z
NAM HAVE INTRODUCED SOME THUNDER TO THE GOING FORECAST AS MODELS
HAVE NOW INDICATED ENOUGH MOISTURE INFLUX AND STEEP ENOUGH MID
LEVEL LAPSE RATES TO GENERATE UP TO 500-700 J/KG OF MUCAPE DURING
THE DAY ON MONDAY. WITH THAT MUCH INSTABILITY IT SEEMS ALMOST
LIKELY AT THIS POINT THAT THUNDERSTORMS WILL BE EMBEDDED WITHIN
THE MONDAY RAIN SHIELD. ONCE THE MAIN UPPER WAVE ENTERS THE
CENTRAL PLAINS ON MONDAY AFTERNOON/EVENING IT WOULD PROVIDE ENOUGH
LIFT TO KICK OFF RAIN SHOWERS ACROSS THE ENTIRE FORECAST AREA.
SURFACE AND LOW LEVEL WINDS SHOULD BE BACKED ON MONDAY AFTERNOON
WHICH IN CONJUNCTION WITH S-SWLY FLOW IN THE LOW TO MID LEVELS
WILL ALLOW FOR SOME TURNING IN THE ATMOSPHERE. WITH 0-6 SHEAR
EXPECTED TO BE ON THE ORDER OF 40 TO 50 KNOTS...THE COMBINATION OF
INSTABILITY WITH SHEAR MAY ALLOW FOR SOME ISOLATED STRONG
THUNDERSTORMS WHICH WOULD ALSO BRING AN ISOLATED HAIL THREAT FOR
MONDAY. ONCE THE SUN SETS ON MONDAY NIGHT THE INSTABILITY SHOULD
WANE RAPIDLY...SO ANY LINGERING SHOWERS BEYOND 8 PM TO 9 PM ON
MONDAY SHOULD BE LIGHT STRATIFORM RAIN AS OPPOSED TO
THUNDERSTORMS. EXPECT PRECIP TO EXIT THE AREA COMPLETELY BY AROUND
MIDNIGHT ON TUESDAY MORNING.
MID RANGE AND EXTENDED FORECAST (TUESDAY THROUGH SATURDAY)...
A RATHER MILD AND UNSEASONABLY WARM WEEK IS ON TAP ONCE THE RAIN
SHOWERS EXIT ON TUESDAY MORNING. A RATHER PRONOUNCED DOWN SLOPE
COMPONENT TO THE WINDS PRESENTS ITSELF FOR TUESDAY AND WEDNESDAY
WHICH SHOULD AID IN WARMING TEMPS FOR THE MID TO LATE WEEK TIME
PERIOD. BROAD UPPER WAVE THEN SLIDES SOUTHEASTWARD LATE IN THE
WEEK...WHICH WILL BRING AN ISOLATED CHANCE FOR SOME PRECIP IN THE
FAR NORTHEASTERN CORNER OF THE STATE. SURFACE HIGH THEN DROPS
SOUTHWARD ON THURSDAY INTO FRIDAY...WHICH WILL BRING A COOLING
TREND FOR THE LATE HALF OF THE WEEK. SINCE THE AIR MASS DOES NOT
LOOK TO BE ARCTIC IN NATURE EXPECT TEMPERATURES TO REMAIN AT OR
SLIGHTLY ABOVE SEASONAL NORMALS.
JL
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
346 AM CST SUN FEB 19 2012
.DISCUSSION...
SHORT RANGE FORECAST (TODAY AND MONDAY)...
EARLY MORNING 11 TO 3.9 MICRON SATELLITE IMAGERY INDICATES THAT ALL
OF NORTHEAST KANSAS REMAINS UNDER MOSTLY CLEAR SKIES. 08Z WATER
VAPOR IMAGERY AND THE ASSOCIATED RUC UPPER AIR ANALYSIS SHOWS A
WEAK UPPER TROUGH MOVING EASTWARD INTO NORTHERN MISSOURI. THIS
TROUGH WILL NOT HAVE MUCH AFFECT ON THE REGION THIS MORNING AS IT
EXITS TO THE EAST. ALSO TO THE WEST...THE NEXT UPPER WAVE IS
BEGINNING TO DIG INTO THE INTERIOR WESTERN US AND SHOULD BE CROSSING
THE GREAT DIVIDE ON SUNDAY NIGHT. THIS WESTERN TROUGH WILL BE THE
ONE TO WATCH AS WE HEAD INTO NEXT WEEK. BETWEEN THE TWO UPPER
TROUGHS IS A SHORTWAVE RIDGE WHICH WILL MOVE OVER THE AREA FOR
SUNDAY. SOUTHERLY WINDS WILL PICK UP THROUGHOUT THE DAY ON
SUNDAY...WHICH IN COMBINATION WITH THE UPPER RIDGE SHOULD ALLOW TEMPS
TO WARM UP A BIT FROM SATURDAY. EXPECT TEMPS TO RISE INTO THE
LOWER 50S TODAY AS THE LOWER ATMOSPHERE SHOULD BE ABLE TO MIX TO
AROUND 850 MB ON SUNDAY.
SOUTHERLY WINDS WILL PERSIST THROUGH THE NIGHT AS THE SURFACE WAVE
DEEPENS AS IT COMES OFF THE HIGH PLAINS. THE LASTING SOUTHERLY
FETCH SHOULD ALLOW DECENT MOISTURE (FOR THIS TIME OF YEAR) TO
RETURN INTO THE CENTRAL PLAINS. MODELS FOR A COUPLE DAYS HAVE
HINTED AT LOWER TO MID 40 DEWPOINTS REACHING INTO NORTHEAST KANSAS
IN ADVANCE OF THE NEXT TROUGH. TAKING A CUE FROM THE 00Z AND 06Z
NAM HAVE INTRODUCED SOME THUNDER TO THE GOING FORECAST AS MODELS
HAVE NOW INDICATED ENOUGH MOISTURE INFLUX AND STEEP ENOUGH MID
LEVEL LAPSE RATES TO GENERATE UP TO 500-700 J/KG OF MUCAPE DURING
THE DAY ON MONDAY. WITH THAT MUCH INSTABILITY IT SEEMS ALMOST
LIKELY AT THIS POINT THAT THUNDERSTORMS WILL BE EMBEDDED WITHIN
THE MONDAY RAIN SHIELD. ONCE THE MAIN UPPER WAVE ENTERS THE
CENTRAL PLAINS ON MONDAY AFTERNOON/EVENING IT WOULD PROVIDE ENOUGH
LIFT TO KICK OFF RAIN SHOWERS ACROSS THE ENTIRE FORECAST AREA.
SURFACE AND LOW LEVEL WINDS SHOULD BE BACKED ON MONDAY AFTERNOON
WHICH IN CONJUNCTION WITH S-SWLY FLOW IN THE LOW TO MID LEVELS
WILL ALLOW FOR SOME TURNING IN THE ATMOSPHERE. WITH 0-6 SHEAR
EXPECTED TO BE ON THE ORDER OF 40 TO 50 KNOTS...THE COMBINATION OF
INSTABILITY WITH SHEAR MAY ALLOW FOR SOME ISOLATED STRONG
THUNDERSTORMS WHICH WOULD ALSO BRING AN ISOLATED HAIL THREAT FOR
MONDAY. ONCE THE SUN SETS ON MONDAY NIGHT THE INSTABILITY SHOULD
WANE RAPIDLY...SO ANY LINGERING SHOWERS BEYOND 8 PM TO 9 PM ON
MONDAY SHOULD BE LIGHT STRATIFORM RAIN AS OPPOSED TO
THUNDERSTORMS. EXPECT PRECIP TO EXIT THE AREA COMPLETELY BY AROUND
MIDNIGHT ON TUESDAY MORNING.
MID RANGE AND EXTENDED FORECAST (TUESDAY THROUGH SATURDAY)...
A RATHER MILD AND UNSEASONABLY WARM WEEK IS ON TAP ONCE THE RAIN
SHOWERS EXIT ON TUESDAY MORNING. A RATHER PRONOUNCED DOWN SLOPE
COMPONENT TO THE WINDS PRESENTS ITSELF FOR TUESDAY AND WEDNESDAY
WHICH SHOULD AID IN WARMING TEMPS FOR THE MID TO LATE WEEK TIME
PERIOD. BROAD UPPER WAVE THEN SLIDES SOUTHEASTWARD LATE IN THE
WEEK...WHICH WILL BRING AN ISOLATED CHANCE FOR SOME PRECIP IN THE
FAR NORTHEASTERN CORNER OF THE STATE. SURFACE HIGH THEN DROPS
SOUTHWARD ON THURSDAY INTO FRIDAY...WHICH WILL BRING A COOLING
TREND FOR THE LATE HALF OF THE WEEK. SINCE THE AIR MASS DOES NOT
LOOK TO BE ARCTIC IN NATURE EXPECT TEMPERATURES TO REMAIN AT OR
SLIGHTLY ABOVE SEASONAL NORMALS.
JL
&&
.AVIATION...
VFR CONDITIONS ARE FORECAST THROUGH THE TAF WITH LIGHT WINDS
OVERNIGHT TURNING OUT OF THE SOUTHEAST AT UP TO 12 KTS ON SUNDAY.
BARJENBRUCH
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
949 PM EST MON FEB 20 2012
.UPDATE...
ISSUED AT 946 PM EST MON FEB 20 2012
MAIN CONCERN OVERNIGHT INTO TUE IS ONSET OF -SN. WATER VAPOR IMAGERY
SHOWS A VIGOROUS SRN SHORTWAVE OVER ERN KS. THIS WAVE IS OUT OF
PHASE WITH THE NRN STREAM TROF OVER SASKATCHEWAN AND THE WRN
DAKATOS. WITH VIGOROUS SRN SHORTWAVE WRAPPING UP AND HEADING MORE
E THAN NE...WOULD EXPECT CURRENT STRONG SOUTHERLY FLOW AND
AGGRESSIVE NORTHWARD PUSH OF MOISTURE/PCPN INTO THE UPPER
MISSISSIPPI VALLEY TO DIMINISH WITH TIME AS THE OUT OF PHASE WAVES
SHIFT E OVERNIGHT INTO TUE. THIS WOULD ALLOW VERY DRY AIRMASS AT THE
LOWER LEVELS PER REGIONAL 00Z SOUNDINGS TO HAVE AN INCREASING
INFLUENCE ON SLOWING/ERODING FRONT EDGE OF PCPN AS IT TRANSLATES
EASTWARD...ESPECIALLY SINCE EASTERLY COMPONENT TO LOW-LEVEL WINDS
WILL HELP MAINTAIN A FEED OF DRY AIR. INHERITED FCST APPEARED TO
HAVE A GOOD HANDLE ON THIS IDEA...SO ONLY MINOR FCST CHANGES HAVE
BEEN MADE TO OVERALL TIMING OF -SN OVERNIGHT INTO TUE. SNOW
ACCUMULATIONS THRU TUE WILL BE ON THE LIGHT SIDE DUE TO SPLIT ENERGY
AND DUE TO ANTECEDANT DRY AIRMASS DELAYING ONSET OF SNOW AT THE SFC.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 346 PM EST MON FEB 20 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER THE
GREAT LKS BTWN TROF IN SE CAN AND ANOTHER IN THE PLAINS. AT THE
SFC...UPR MI LIES UNDER A SHARPENING PRES GRADIENT BTWN SFC HI PRES
OVER OH AND LOWER PRES IN THE PLAINS UNDER THE TROF. ALTHOUGH HI
CLDS ARE STREAMING OVHD IN THE SW FLOW ALF...12Z RAOBS TO THE S AT
GRB/MPX/AND QUAD CITIES IA SHOW DRY LO/MID LVLS. SINCE THE SUN IS
JUST FILTERED A BIT BY THESE HI CLDS...TEMPS HAVE REBOUNDED TO WELL
ABV NORMAL LVLS AGAIN AND WELL INTO THE 30S AT MOST SPOTS EARLY THIS
AFTN. ALTHOUGH THERE A LARGER SCALE TROF IN THE PLAINS...SEVERAL OUT
OF PHASE SHRTWVS ARE PRESENT WITHIN THE BROADER AREA OF LOWER HGTS.
THE STRONGEST OF THESE IS OVER THE SCNTRL PLAINS...WITH ANOTHER OVER
SASKATCHEWAN.
MAIN FCST CONCERNS THRU TUE REVOLVE ARND PCPN CHCS TNGT/TUE RELATED
TO EWD PROGRESSION OF PLAINS TROF AND EMBEDDED SHRTWVS. RECENT MODEL
RUNS ARE IN FAIRLY GOOD AGREEMENT SHOWING SHRTWVS/ASSOCIATED SFC LO
CENTERS REMAINING OUT OF PHASE THRU TUE...WHICH WILL LIMIT PCPN
TOTALS OVER THE CWA. IN GENERAL...FOLLOWED THE GFS FOR FCST DETAILS
AT THIS MODEL SHOWS MORE PERSISTENT LLVL DRY AIR WITH MORE MSTR TIED
TO THE STRONGER SRN DISTURBANCE FCST TO TRACK THRU THE LOWER LKS.
TNGT...SHRTWV OVER SASKATCHEWAN IS FCST TO DIG TOWARD MN BY 12Z
WHILE SRN DISTURBANCE MOVES INTO ILLINOIS. PREFERRED GFS SHOWS MORE
IMPRESSIVE QVECTOR CNVGC TENDING TO REMAIN TO THE W AND S OF THE FA.
SINCE SLOWLY BACKING WINDS FM THE SSW TOWARD THE SE WL MAINTAIN LLVL
DRY AIR FEED...PREFERRED GFS MODEL INDICATES PERSISTENT DRY WEDGE IN
THE LLVLS PERSISTING THRU 12Z OVER UPR MI. SO EXCEPT FOR WRN LK
SUP...WHICH WL BE CLOSEST TO INCOMING DYNAMICS ASSOCIATED WITH THE
NRN DISTURBANCE...TENDED TO CUT POPS OVER THE CWA. DESPITE LINGERING
DRY AIR IN THE LLVLS...A STRONGER SW FLOW AND THICKENING HI CLDS WL
PREVENT TEMPS FM FALLING AS SHARPLY AS THE LAST FEW NIGHTS.
TUE...WHILE SRN SHRTWV MOVES ENEWD WELL S OF THE FA...THE NRN
DISTURBANCE IS FCST TO DRIFT EWD INTO THE UPR LKS. WITH INCRSG DPVA/
LLVL MOISTENING/LARGE SCALE QVECTOR CNVGC/SOME UPR DVGC...EXPECT
INCRSG POPS TOWARD CATEGORICAL IN THE AFTN. HOWEVER...SINCE MOST OF
THE DYNAMICS WL BE SPENT SATURATING THE INITIALLY DRY LO/MID LVLS...
PCPN AMNTS WL BE RELATIVELY LGT AND UNDER 0.25 INCH. ALTHOUGH MAX
TEMPS WL TOP OUT OVER 32 ALMOST EVERYWHERE...DYNAMIC/WBLB COOLING
SHOULD KEEP PCPN IN THE FORM OF SN PER GFS FCST SNDGS AND H100-85
THKNS/WBZ HGT BLO CRITICAL LVLS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 346 PM EST MON FEB 20 2012
THE SLOW MOVING 500MB LOW OVER CENTRAL SASKATCHEWAN THIS AFTERNOON
WILL BE OVER N MN/W LAKE SUPERIOR AT 00Z WEDNESDAY...SETTING US UP
FOR AN ACTIVE PERIOD OF LIGHT SNOW SHOWERS.
EXPECT THE 500MB LOW TO BE DIRECTLY OVER UPPER MI AT 06Z
WEDNESDAY...WITH THE 20/06Z GFS SHOWING MORE OF AN OPEN WAVE INSTEAD
OF A CLOSED LOW. THE RESULT IS A MORE PROGRESSIVE /THAN THE
CONSENSUS AND ITS 20/00Z RUN/. EVEN AT THE SFC THE LOW IS QUITE A
BIT FARTHER TO THE SOUTH...BUT WITHIN REASON. ANOTHER DISCREPANCY
WOULD BE FROM THE 20/06Z NAM...WITH IS ON THE SLOW SIDE NEARLY RIGHT
OFF THE BAT. THE DIFFERENCE BETWEEN THE PLACEMENT OF THE FASTER GFS
AND SLOWER NAM IS ROUGHLY 240MI. EXPECT THE ELONGATED TO DOUBLE
BARREL SFC LOW STRETCHING FROM N MN TO SE IA AT 12Z TUESDAY TO
DEEPEN ACROSS E LAKE SUPERIOR TUESDAY NIGHT...BEFORE SLIDING ALMOST
DIRECTLY E INTO S QUEBEC LATE TUESDAY NIGHT INTO WEDNESDAY. WHILE A
SFC TROUGH WILL LINGER BEHIND THE EXITING LOW...IT WILL BE OF SHORT
DURATION...AS A SFC RIDGE QUICKLY BUILDS IN WEDNESDAY AFTERNOON
AHEAD OF THE NEXT LOW. ANOTHER HINDRANCE TO HEAVY SNOW WILL BE THE
RELATIVELY MILD 850MB TEMPS NEAR -8C...AND PREDOMINANT WNW WINDS
BEHIND THE SFC LOW. WHILE LAKE ENHANCEMENT WILL BE POSSIBLE AS THE
LOW MOVES OVERHEAD...SHIFTING WINDS WILL DETER SIGNIFICANT AMOUNTS.
THE BEST CHANCE OF RECEIVING 2-5 INCHES WOULD BE FROM IWD TO
CMX.
THE NEXT 500MB FEATURE OF IMPORTANCE WILL BE IN THE FORM OF A S
CENTRAL CANADIAN TROUGH WEDNESDAY NIGHT...SLIDING ACROSS THE UPPER
GREAT LAKES THURSDAY AFTERNOON. THE CONSENSUS IS TO HAVE THIS TROUGH
DEEPEN INTO A LOW UPPER MI FRIDAY...BEFORE MOVING INTO S QUEBEC
FRIDAY NIGHT. WHILE THE ORIGINS OF THE SFC LOW...OVER SASKATCHEWAN
WEDNESDAY AFTERNOON WOULD INDICATE ANOTHER LOW WITH LITTLE IN THE
WAY OF MOISTURE TO WORK WITH...ITS PROGRESSION WILL ALLOW THE GULF
TO OPEN UP. EXPECT THE SFC LOW TO RESIDE BETWEEN CENTRAL WI/CENTRAL
LOWER MI/CENTRAL UPPER MI AT 18Z THURSDAY /WITH THE ECMWF FARTHER
SOUTH THAN THIS/...AND A COLD FRONT DRAGGING ACROSS IL/MO/AND INTO
NE TX. THE SFC LOW SHOULD DEEPEN AS IT SLIDES EAST OF OUR
AREA...THURSDAY NIGHT NEAR THE LOWER GREAT LAKES...AND FRIDAY
AFTERNOON/EVENING OVER S QUEBEC. AS THE SYSTEM DEEPENS AND TAPS INTO
ADDITIONAL MOISTURE OFF THE ATLANTIC IT SHOULD WRAP IN STEADY N
WINDS SLOWLY BECOMING NW...AND PLENTY OF COLD AIR TO OUR REGION
FRIDAY AFTERNOON THROUGH SATURDAY NIGHT. 850MB TEMPS AT THIS POINT
THE PRESSURE GRADIENT BECOMES FAIRLY WEEK WITH A SFC RIDGE NEARLY
OVERHEAD.
PRECIPITATION TYPE MAY BE A CONCERN FOR THIS SYSTEM OVER THE SE
CORNER OF THE CWA RIGHT ALONG LAKE MICHIGAN. 850MB TEMPS OF THE
20/06Z GFS ARE AROUND -4C...WITH THE MNM SOUNDING SHOWING
INDICATIONS OF RA FROM MID MORNING THROUGH THE REMAINDER OF THE
DAYTIME HOURS THURSDAY. THE EVEN WARMER/MORE WRAPPED UP 20/00Z
CANADIAN WOULD HAVE 850MB TEMPS AROUND -2C OVER THE ENTIRE CWA
AROUND 12Z THURSDAY...LINGERING EAST AS THE LOW EXITS EARLY THURSDAY
EVENING. WILL NOT CONCENTRATE TOO MUCH ON THIS...AS THERE ARE LARGER
DISCREPANCIES...WITH THE NAM AND ECMWF NOT TOO ENTHUSED ABOUT THE
NORTHERN EXTENT OF THE SYSTEM...WITH THE BULK OF THE MOISTURE
REMAINING OVER IL/IN/OH. BOTH THE GFS AND ECMWF SHOW GOOD RUN TO RUN
CONSISTENCY...WITH A BLEND LOOKING REASONABLE AT THIS TIME. THE 12Z
RUNS OF THE GFS AND ECMWF KEPT WITH A MORE SOUTHERLY SOLUTION FOR
THIS SYSTEM...CLOSER TO THE 00Z RUN OF THE ECMWF. THIS TREND WOULD
CONTINUE TO LIMIT THE MENTION OF RAIN NEAR LAKE MICHIGAN. NO MATTER
WHICH SOLUTION OR GROUP OF SOLUTIONS IS PREFERRED...850MB TEMPS
SHOULD FALL BETWEEN -12 AND -16C FROM FRIDAY NIGHT ON...WITH
FAVORABLE WINDS OFF LAKE SUPERIOR PRODUCING LIGHT TO MODERATE SNOW
SHOWERS.
BEYOND FRIDAY NIGHT THE 20/06Z GFS AND 20/00Z ECMWF BECOME OUT OF
PHASE. THIS IS BEST INDICATED BY THE LATE SATURDAY AFTERNOON/SUNDAY
NIGHT TRENDS AT 500MB OVER THE GREAT LAKES...WITH THE ECMWF
INDICATING A RIDGE AND THE GFS A TROUGH. THIS IS MAINLY DUE TO THE
HANDLING OF THE LOW EJECTING E SATURDAY. THE ECMWF IS ON THE QUICKER
SIDE...WHILE THE LAST 2 GFS RUNS CONTINUE TO DEEPEN THE LOW AS IT
SHIFTS INTO FAR EASTERN CANADA. AS A RESULT...WILL NOT TRY TO PIN
POINT SPECIFICS BEYOND SATURDAY NIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 631 PM EST MON FEB 20 2012
ALTHOUGH A LOW PRES TROF OVER THE PLAINS WILL CONTINUE MOVING E...
DRY AIR AT THE LWR LEVELS WILL LINGER UNDER SSE FLOW...ALLOWING VFR
CONDITIONS TO PERSIST THRU THE EVENING AND PROBABLY NIGHT AT
KIWD/KCMX/KSAW. WITH PRES GRADIENT TIGHTENING OVER UPPER MI...
MAINTAINED FCST OF LLWS AT ALL 3 SITES FOR AT LEAST A TIME TONIGHT
BEFORE GRADIENT BEGINS TO WEAKEN LATE. AS THE LOW PRES TROF TO THE W
MOVES CLOSER TUE AND SOME -SN OVERSPREADS THE AREA...MVFR CONDITIONS
WILL PREDOMINATE BY LATE MORNING. DEPENDING ON COVERAGE/INTENSITY OF
SNOW...MIGHT SEE IFR CIGS DEVELOP IN THE AFTN WHERE WINDS UPSLOPE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 346 PM EST MON FEB 20 2012
WITH AN UNSEASONABLY WEAK PRES GRADIENT FORECAST THIS WEEK...EXPECT
WINDS NO HIER THAN 25 KTS. NO GALES ARE FORECAST IN THE NEAR FUTURE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...NONE.
LAKE SUPERIOR...NONE.
LAKE MICHIGAN...NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
636 PM EST MON FEB 20 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 346 PM EST MON FEB 20 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER THE
GREAT LKS BTWN TROF IN SE CAN AND ANOTHER IN THE PLAINS. AT THE
SFC...UPR MI LIES UNDER A SHARPENING PRES GRADIENT BTWN SFC HI PRES
OVER OH AND LOWER PRES IN THE PLAINS UNDER THE TROF. ALTHOUGH HI
CLDS ARE STREAMING OVHD IN THE SW FLOW ALF...12Z RAOBS TO THE S AT
GRB/MPX/AND QUAD CITIES IA SHOW DRY LO/MID LVLS. SINCE THE SUN IS
JUST FILTERED A BIT BY THESE HI CLDS...TEMPS HAVE REBOUNDED TO WELL
ABV NORMAL LVLS AGAIN AND WELL INTO THE 30S AT MOST SPOTS EARLY THIS
AFTN. ALTHOUGH THERE A LARGER SCALE TROF IN THE PLAINS...SEVERAL OUT
OF PHASE SHRTWVS ARE PRESENT WITHIN THE BROADER AREA OF LOWER HGTS.
THE STRONGEST OF THESE IS OVER THE SCNTRL PLAINS...WITH ANOTHER OVER
SASKATCHEWAN.
MAIN FCST CONCERNS THRU TUE REVOLVE ARND PCPN CHCS TNGT/TUE RELATED
TO EWD PROGRESSION OF PLAINS TROF AND EMBEDDED SHRTWVS. RECENT MODEL
RUNS ARE IN FAIRLY GOOD AGREEMENT SHOWING SHRTWVS/ASSOCIATED SFC LO
CENTERS REMAINING OUT OF PHASE THRU TUE...WHICH WILL LIMIT PCPN
TOTALS OVER THE CWA. IN GENERAL...FOLLOWED THE GFS FOR FCST DETAILS
AT THIS MODEL SHOWS MORE PERSISTENT LLVL DRY AIR WITH MORE MSTR TIED
TO THE STRONGER SRN DISTURBANCE FCST TO TRACK THRU THE LOWER LKS.
TNGT...SHRTWV OVER SASKATCHEWAN IS FCST TO DIG TOWARD MN BY 12Z
WHILE SRN DISTURBANCE MOVES INTO ILLINOIS. PREFERRED GFS SHOWS MORE
IMPRESSIVE QVECTOR CNVGC TENDING TO REMAIN TO THE W AND S OF THE FA.
SINCE SLOWLY BACKING WINDS FM THE SSW TOWARD THE SE WL MAINTAIN LLVL
DRY AIR FEED...PREFERRED GFS MODEL INDICATES PERSISTENT DRY WEDGE IN
THE LLVLS PERSISTING THRU 12Z OVER UPR MI. SO EXCEPT FOR WRN LK
SUP...WHICH WL BE CLOSEST TO INCOMING DYNAMICS ASSOCIATED WITH THE
NRN DISTURBANCE...TENDED TO CUT POPS OVER THE CWA. DESPITE LINGERING
DRY AIR IN THE LLVLS...A STRONGER SW FLOW AND THICKENING HI CLDS WL
PREVENT TEMPS FM FALLING AS SHARPLY AS THE LAST FEW NIGHTS.
TUE...WHILE SRN SHRTWV MOVES ENEWD WELL S OF THE FA...THE NRN
DISTURBANCE IS FCST TO DRIFT EWD INTO THE UPR LKS. WITH INCRSG DPVA/
LLVL MOISTENING/LARGE SCALE QVECTOR CNVGC/SOME UPR DVGC...EXPECT
INCRSG POPS TOWARD CATEGORICAL IN THE AFTN. HOWEVER...SINCE MOST OF
THE DYNAMICS WL BE SPENT SATURATING THE INITIALLY DRY LO/MID LVLS...
PCPN AMNTS WL BE RELATIVELY LGT AND UNDER 0.25 INCH. ALTHOUGH MAX
TEMPS WL TOP OUT OVER 32 ALMOST EVERYWHERE...DYNAMIC/WBLB COOLING
SHOULD KEEP PCPN IN THE FORM OF SN PER GFS FCST SNDGS AND H100-85
THKNS/WBZ HGT BLO CRITICAL LVLS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 346 PM EST MON FEB 20 2012
THE SLOW MOVING 500MB LOW OVER CENTRAL SASKATCHEWAN THIS AFTERNOON
WILL BE OVER N MN/W LAKE SUPERIOR AT 00Z WEDNESDAY...SETTING US UP
FOR AN ACTIVE PERIOD OF LIGHT SNOW SHOWERS.
EXPECT THE 500MB LOW TO BE DIRECTLY OVER UPPER MI AT 06Z
WEDNESDAY...WITH THE 20/06Z GFS SHOWING MORE OF AN OPEN WAVE INSTEAD
OF A CLOSED LOW. THE RESULT IS A MORE PROGRESSIVE /THAN THE
CONSENSUS AND ITS 20/00Z RUN/. EVEN AT THE SFC THE LOW IS QUITE A
BIT FARTHER TO THE SOUTH...BUT WITHIN REASON. ANOTHER DISCREPANCY
WOULD BE FROM THE 20/06Z NAM...WITH IS ON THE SLOW SIDE NEARLY RIGHT
OFF THE BAT. THE DIFFERENCE BETWEEN THE PLACEMENT OF THE FASTER GFS
AND SLOWER NAM IS ROUGHLY 240MI. EXPECT THE ELONGATED TO DOUBLE
BARREL SFC LOW STRETCHING FROM N MN TO SE IA AT 12Z TUESDAY TO
DEEPEN ACROSS E LAKE SUPERIOR TUESDAY NIGHT...BEFORE SLIDING ALMOST
DIRECTLY E INTO S QUEBEC LATE TUESDAY NIGHT INTO WEDNESDAY. WHILE A
SFC TROUGH WILL LINGER BEHIND THE EXITING LOW...IT WILL BE OF SHORT
DURATION...AS A SFC RIDGE QUICKLY BUILDS IN WEDNESDAY AFTERNOON
AHEAD OF THE NEXT LOW. ANOTHER HINDRANCE TO HEAVY SNOW WILL BE THE
RELATIVELY MILD 850MB TEMPS NEAR -8C...AND PREDOMINANT WNW WINDS
BEHIND THE SFC LOW. WHILE LAKE ENHANCEMENT WILL BE POSSIBLE AS THE
LOW MOVES OVERHEAD...SHIFTING WINDS WILL DETER SIGNIFICANT AMOUNTS.
THE BEST CHANCE OF RECEIVING 2-5 INCHES WOULD BE FROM IWD TO
CMX.
THE NEXT 500MB FEATURE OF IMPORTANCE WILL BE IN THE FORM OF A S
CENTRAL CANADIAN TROUGH WEDNESDAY NIGHT...SLIDING ACROSS THE UPPER
GREAT LAKES THURSDAY AFTERNOON. THE CONSENSUS IS TO HAVE THIS TROUGH
DEEPEN INTO A LOW UPPER MI FRIDAY...BEFORE MOVING INTO S QUEBEC
FRIDAY NIGHT. WHILE THE ORIGINS OF THE SFC LOW...OVER SASKATCHEWAN
WEDNESDAY AFTERNOON WOULD INDICATE ANOTHER LOW WITH LITTLE IN THE
WAY OF MOISTURE TO WORK WITH...ITS PROGRESSION WILL ALLOW THE GULF
TO OPEN UP. EXPECT THE SFC LOW TO RESIDE BETWEEN CENTRAL WI/CENTRAL
LOWER MI/CENTRAL UPPER MI AT 18Z THURSDAY /WITH THE ECMWF FARTHER
SOUTH THAN THIS/...AND A COLD FRONT DRAGGING ACROSS IL/MO/AND INTO
NE TX. THE SFC LOW SHOULD DEEPEN AS IT SLIDES EAST OF OUR
AREA...THURSDAY NIGHT NEAR THE LOWER GREAT LAKES...AND FRIDAY
AFTERNOON/EVENING OVER S QUEBEC. AS THE SYSTEM DEEPENS AND TAPS INTO
ADDITIONAL MOISTURE OFF THE ATLANTIC IT SHOULD WRAP IN STEADY N
WINDS SLOWLY BECOMING NW...AND PLENTY OF COLD AIR TO OUR REGION
FRIDAY AFTERNOON THROUGH SATURDAY NIGHT. 850MB TEMPS AT THIS POINT
THE PRESSURE GRADIENT BECOMES FAIRLY WEEK WITH A SFC RIDGE NEARLY
OVERHEAD.
PRECIPITATION TYPE MAY BE A CONCERN FOR THIS SYSTEM OVER THE SE
CORNER OF THE CWA RIGHT ALONG LAKE MICHIGAN. 850MB TEMPS OF THE
20/06Z GFS ARE AROUND -4C...WITH THE MNM SOUNDING SHOWING
INDICATIONS OF RA FROM MID MORNING THROUGH THE REMAINDER OF THE
DAYTIME HOURS THURSDAY. THE EVEN WARMER/MORE WRAPPED UP 20/00Z
CANADIAN WOULD HAVE 850MB TEMPS AROUND -2C OVER THE ENTIRE CWA
AROUND 12Z THURSDAY...LINGERING EAST AS THE LOW EXITS EARLY THURSDAY
EVENING. WILL NOT CONCENTRATE TOO MUCH ON THIS...AS THERE ARE LARGER
DISCREPANCIES...WITH THE NAM AND ECMWF NOT TOO ENTHUSED ABOUT THE
NORTHERN EXTENT OF THE SYSTEM...WITH THE BULK OF THE MOISTURE
REMAINING OVER IL/IN/OH. BOTH THE GFS AND ECMWF SHOW GOOD RUN TO RUN
CONSISTENCY...WITH A BLEND LOOKING REASONABLE AT THIS TIME. THE 12Z
RUNS OF THE GFS AND ECMWF KEPT WITH A MORE SOUTHERLY SOLUTION FOR
THIS SYSTEM...CLOSER TO THE 00Z RUN OF THE ECMWF. THIS TREND WOULD
CONTINUE TO LIMIT THE MENTION OF RAIN NEAR LAKE MICHIGAN. NO MATTER
WHICH SOLUTION OR GROUP OF SOLUTIONS IS PREFERRED...850MB TEMPS
SHOULD FALL BETWEEN -12 AND -16C FROM FRIDAY NIGHT ON...WITH
FAVORABLE WINDS OFF LAKE SUPERIOR PRODUCING LIGHT TO MODERATE SNOW
SHOWERS.
BEYOND FRIDAY NIGHT THE 20/06Z GFS AND 20/00Z ECMWF BECOME OUT OF
PHASE. THIS IS BEST INDICATED BY THE LATE SATURDAY AFTERNOON/SUNDAY
NIGHT TRENDS AT 500MB OVER THE GREAT LAKES...WITH THE ECMWF
INDICATING A RIDGE AND THE GFS A TROUGH. THIS IS MAINLY DUE TO THE
HANDLING OF THE LOW EJECTING E SATURDAY. THE ECMWF IS ON THE QUICKER
SIDE...WHILE THE LAST 2 GFS RUNS CONTINUE TO DEEPEN THE LOW AS IT
SHIFTS INTO FAR EASTERN CANADA. AS A RESULT...WILL NOT TRY TO PIN
POINT SPECIFICS BEYOND SATURDAY NIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 631 PM EST MON FEB 20 2012
ALTHOUGH A LOW PRES TROF OVER THE PLAINS WILL CONTINUE MOVING E...
DRY AIR AT THE LWR LEVELS WILL LINGER UNDER SSE FLOW...ALLOWING VFR
CONDITIONS TO PERSIST THRU THE EVENING AND PROBABLY NIGHT AT
KIWD/KCMX/KSAW. WITH PRES GRADIENT TIGHTENING OVER UPPER MI...
MAINTAINED FCST OF LLWS AT ALL 3 SITES FOR AT LEAST A TIME TONIGHT
BEFORE GRADIENT BEGINS TO WEAKEN LATE. AS THE LOW PRES TROF TO THE W
MOVES CLOSER TUE AND SOME -SN OVERSPREADS THE AREA...MVFR CONDITIONS
WILL PREDOMINATE BY LATE MORNING. DEPENDING ON COVERAGE/INTENSITY OF
SNOW...MIGHT SEE IFR CIGS DEVELOP IN THE AFTN WHERE WINDS UPSLOPE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 346 PM EST MON FEB 20 2012
WITH AN UNSEASONABLY WEAK PRES GRADIENT FORECAST THIS WEEK...EXPECT
WINDS NO HIER THAN 25 KTS. NO GALES ARE FORECAST IN THE NEAR FUTURE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...NONE.
LAKE SUPERIOR...NONE.
LAKE MICHIGAN...NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
352 PM EST SUN FEB 19 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 347 PM EST SUN FEB 19 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR LKS BTWN TROF IN QUEBEC AND UPR RDG MOVING E THRU THE
PLAINS. SFC HI PRES RDG IS ORIENTED FM LOWER MI INTO SRN WI...
BRINGING QUIET DAY TO THE CWA. EXCEPT FOR LINGERING SC E OF ERY
TOWARD BACK EDGE OF SLOWLY DEPARTING H925 THERMAL TROF/A BIT MORE
LLVL MSTR SHOWN ON THE 12Z APX RAOB...SKIES ARE GENERALLY SUNNY OVER
THE CWA AS 12Z GRB/MPX/INL RAOBS DEPICT A DRY AIRMASS WITH PWAT 0.15
TO 0.20 INCH. THERE IS A SHRTWV DROPPING ESEWD OVER THE UPR LKS...
BUT ONLY SOME HI CLDS MARK THE PRESENCE OF THIS FEATURE WITH DRY LO/
MID LVLS PRESENT. ALTHOUGH MIN TEMPS THIS MRNG FELL BLO ZERO AT A
NUMBER OF INTERIOR LOCATIONS...THE BRIGHT SUNSHINE HAS HELPED THE
MERCURY RECOVER TO WELL ABV NORMAL LEVELS THIS AFTN. FARTHER TO THE
W...THERE IS A TROF IN THE ROCKIES. QUITE A BIT OF HI CLDS ARE
STREAMING NEWD THRU THE PLAINS TOWARD MN IN THE SW FLOW ALF AHEAD OF
THIS FEATURE.
MAIN FCST CONCERNS IN THE SHORT TERM ARE TEMPS WITH HI PRES RDG
EXPECTED TO DOMINATE.
TNGT...UPR RDG IS FCST TO BUILD OVHD TNGT WITH DRY AIRMASS STILL
DOMINATING. ANY LINGERING LO CLDS OVER THE FAR ERN CWA SHOULD BE
GONE BY FCST ISSUANCE WITH WLY FLOW/WARMING AND DRYING AT H925.
EXPECT THE LOWEST MIN TEMPS AOB THE LO END OF GUIDANCE OVER THE
INTERIOR E AND SCNTRL UNDER WEAKER PRES GRADIENT/LIGHTER SW FLOW
ARND HI PRES CENTERED OVER LOWER MI. ADDED SOME PATCHY FOG IN THESE
AREAS OVER THE E WHERE SFC DEWPTS REMAIN FAIRLY HI AOA 20. A BIT
STRONGER SW FLOW OVER THE NW HALF AND THE ARRIVAL OF SOME HI CLDS
AHEAD OF THE SLOWLY PROGRESSIVE ROCKIES TROF WL LIMIT THE DIURNAL
FALL OF TEMP IN THAT AREA A BIT.
MON...EXPECT INCRSG SLY FLOW OVER UPR MI BTWN DEPARTING UPR RDG/SFC
HI TO THE E AND APRCHG UPR TROF THRU THE PLAINS IN PROGRESSIVE
PATTERN ALF. ALTHOUGH THERE WL BE QUITE A BIT OF HI CLD UNDER THE SW
FLOW ALF...THE LO/MID LVLS WL REMAIN QUITE DRY. H85 TEMPS ARE FCST
TO RISE CLOSE TO 0C OVER THE W BY LATE IN THE DAY...SO EXPECT A
HEALTHY DIURNAL TEMP RECOVERY DESPITE THE HI CLD COVER. TEMPS ARE
LIKELY TO BE HIEST IN THE DOWNSLOPE AREAS NEAR LK SUP FM IWD-COPPER
HARBOR...BARAGA AND MQT. TEMPS ARE LIKELY TO REACH 40 OR BETTER IN
THESE LOCATIONS. AREAS NEAR THE ICE ON THE BAY OF GREEN BAY WL BE
COOLEST.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 347 PM EST SUN FEB 19 2012
SPLIT FLOW TO START THE PERIOD WITH STRONGER JET STREAM REMAINING IN
THE SOUTHERN BRANCH. MODELS ARE IN PRETTY GOOD AGREEMENT WITH
PLACEMENT OF THE TWO SHORTWAVE TROUGHS OVR CENTRAL CONUS INTO SOUTH
CENTRAL CANADA ON MONDAY EVENING. UPR LEVEL WAVES STILL LOOK TO
REMAIN SEPARATE INTO TUESDAY BUT H85 LOWS DO TRY TO MERGE TOGETHER
OVR NW ONTARIO AND LK SUPERIOR REGION BY TUESDAY AFTN. RESULT IS A
SW FLOW OF INCREASING MOISTURE INTO UPR MI LATER MONDAY NIGHT INTO
TUESDAY. MORE ABUNDANT MOISTURE/HIGHER PWATS STAY TIED TO SOUTHERN
STREAM UPR SYSTEM TRACKING ACROSS NORTHERN OHIO VALLEY INTO CNTRL
GREAT LAKES. EXPECT SWATH OF SNOW FORCED BY DIVERGENCE FM UPR JET
AND MID LEVEL FRONTOGENEIS TO LIFT INTO WESTERN UPR MI AFTER
MIDNIGHT MONDAY NIGHT THROUGH MID MORNING ON TUESDAY. SNOW SHOULD
FADE AWAY THROUGH THE DAY WHILE MOVING EAST AS MAIN MOISTURE STREAMS
BEGIN TO SPLIT AROUND UPR MI. BEST CHANCE FOR ACCUMULATING SNOW
WOULD BE IN THE FAR WESTERN CWA AROUND KIWD EARLY ON TUESDAY. DID
OPT FOR MENTION OF RAIN ALONG IMMEDIATE LK MICHIGAN SHORE LATER ON
TUESDAY WITH ONSHORE WINDS.
KIND OF A TRICKY FCST BEYOND TUESDAY AT THIS POINT...ESPECIALLY
THROUGH THURSDAY. MAIN ITEM CASTING UNCERTAINTY IS GENERAL TROUGHING
STAYING PUT FM SCNTRL CANADA INTO UPR LAKES. INITALLY ON TUESDAY
NIGHT...PRIMARY FOCUS FOR WIDESPREAD/STEADY PCPN SHOULD BE NORTH AND
NORTHEAST OF UPR MI OVER ONTARIO/QUEBEC IN VCNTY OF SFC-H85 LOW.
H85-H7 MOISTURE DOES LINGER THOUGH...ESPECIALLY OVR LK SUPERIOR.
MOISTURE COMBINED WITH WESTERLY FLOW AND H85 TEMPS DOWN TO AROUND
-10C COULD LEAD TO LGT SNOW SHOWERS ACROSS KEWEENAW. MINIMAL CHANGE
INTO WEDNESDAY...AS WEST-NORTHWEST LOW-LEVEL WINDS PERSIST OVER THE
AREA AS SFC LOW LIFTS INTO QUEBEC. UPR LAKES IS WITHIN BASE OF LARGER
TROUGH...SO THERE COULD BE SOME SHORTWAVES SLIDING BY IN THE FLOW
THAT ARE NOT DEPICTED IN THE MODELS RIGHT NOW. OVERALL...SEEMS LIKE
SOME SMALL CHANCE POPS ARE JUSTIFIED...BUT NOTHING MORE AT THIS
POINT.
FOR THE EXTENDED...YESTERDAY IT LOOKED LIKE ONCE SFC-H85 LOWS WOULD
TRACK INTO QUEBEC IT WOULD USHER IN NW FLOW LK EFFECT BY THURSDAY
INTO FRIDAY. PATTERN LOOKING NOT AS CLEAR CUT NOW. MODELS...
ESPECIALLY LATEST VERSIONS OF GFS AND CANADIAN...POINT TO STRONGER
COMPACT LOW PRESSURE SYSTEM RIDING SOUTHERN EDGE OF THE TROUGH FM
NORTHERN ROCKIES ACROSS THE NORTHERN PLAINS WEDNESDAY AND WEDNESDAY
NIGHT AND INTO UPR GREAT LAKES THURSDAY/THURSDAY NIGHT. EARLIER THE
GFS WAS FARTHEST NORTH WITH THE LOW/QPF THAN OTHER MODELS...BUT
LATEST CANADIAN NOW TAKES THAT TITLE. ECMWF IS FARTHER SOUTH AND
MORE SHEARED OUT WITH THE DISTURBANCE. BLEND OF MODELS AND THE GFS
ENSEMBLE WOULD SUGGEST FAR SOUTH CWA SEES THE BEST CHANCE OF SNOW
LATER WEDNESDAY NIGHT INTO THURSDAY. DETAILS ARE FAR FM SET THOUGH.
GIVEN UNCERTAINTY WILL STEER AWAY FM LK EFFECT POP IDEA FOR THURSDAY
AND OPEN UP MOST OF CWA FOR LOW CHANCE POPS. MOST MODELS INDICATE
LOW-LEVEL WINDS OVR NOTHERN CWA WOULD BE FM THE NORTH OR NORTHEAST
THURSDAY/THURSDAY NIGHT WITH AT LEAST SUFFICIENT LOW-LEVEL MOISTURE.
INSTABILITY WOULD BE MARGINAL WITH DELTA T/S ONLY UP TO 13C. IF THE
LOW PRESSURE DOES TRACK FARTHER NORTH...THEN THERE WOULD BE MORE
POTENTIAL OF LAKE ENHANCEMENT.
EVENTUALLY...EXPECT NW FLOW LK EFFECT TO DEVELOP OVR THE AREA IN
WAKE OF THIS SYSTEM LATER THURSDAY NIGHT INTO FRIDAY AND ON INTO
SATURDAY AS WELL. H85-H7 DEEPER MOISTURE ALONG WITH SUFFICIENT
OVER-WATER INSTABILITY MAY SUPPORT SOME MODERATE ACCUMS IN THE
THURSDAY NIGHT/FRIDAY TIME FRAME. COLDEST DAYS OVR THE CWA SHOULD
BE FRIDAY AND SATURDAY...WITH HIGHS STAYING IN THE TEENS FOR SOME OF
THE AREA. SUFFICIENTLY COLD AIR /H85 TEMPS BLO -15C/ PERSISTS INTO
SATURDAY THOUGH DECREASING SUB H85 MOISTURE AND LOWERING INVERSIONS
WITH ARRIVAL OF SFC-H85 RIDGE SHOULD BEGIN TO PUT DENT IN THE LK
EFFECT. UNCERTAINTY BACK INTO FCST BY SUNDAY AS GFS AND PREVIOUS
ECMWF WERE OUT OF PHASE WITH EACH OTHER. LATEST ECMWF IS MORE IN
LINE WITH GFS IDEA THOUGH SUGGESTING SYSTEM SNOW COULD RETURN TO UPR
LAKES LATE NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1223 PM EST SUN FEB 19 2012
EXPECT VFR CONDITIONS THIS FCST PERIOD WITH DRY HI PRES DOMINATING.
A STRONGER S WIND WILL DEVELOP ON MON UNDER SHARPENING PRES GRADIENT
BTWN DEPARTING HI PRES AND LO PRES APRCHG FM THE PLAINS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 347 PM EST SUN FEB 19 2012
WITH AN UNSEASONABLY WEAK PRES GRADIENT FORECAST INTO TUE...EXPECT
WINDS NO HIER THAN 25 KTS. A STRONGER W WIND TO 30 KTS IS POSSIBLE
TUE NIGHT AND WED ON THE SOUTHERN FLANK OF LO PRES CROSSING ONTARIO.
THERE MAY BE SOME GALE FORCE GUSTS OVER PORTIONS OF NCENTRAL AND
EASTERN LK SUP. MAINLY NORTH TO NORTHWEST WINDS LESS THAN 30 KTS
EXPECTED LATE THIS WEEK AS COLDER AIR RETURNS TO THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC/JLA
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1232 AM EST SUN FEB 19 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 342 PM EST SAT FEB 18 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER
THE UPR GRT LKS BTWN TROF CENTERED OVER QUEBEC AND A RDG ACRS WCNTRL
CAN. SHRTWV EMBEDDED WITHIN THIS FLOW IS OVER LOWER MI AND DIGGING
SEWD...LEAVING THE CWA UNDER VIGOROUS DNVA/UPR CNVGC/00Z-12Z H3
RISES AOA 100M IN ITS WAKE. ASSOCIATED SFC HI PRE RDG EXTENDS FM NW
ONTARIO INTO MN. DESPITE THE VIGOROUS SUBSIDENCE ASSOCIATED WITH
THESE DYNAMICS...PLENTY OF LO CLDS LINGER NOT ONLY OVER UPR MI IN
THE CHILLY LLVL NW FLOW E OF THE INCOMING RDG AXIS BUT ALSO INTO NRN
MN RIGHT UNDER THE RDG AXIS. IN FACT...THE 12Z INL/YPL RAOBS DEPICT
A STRONG SUBSIDENCE INVRN. HOWEVER SINCE THE INVRN BASE IS
SURPRISINGLY HI H85-875...THERE IS AMPLE DEPTH FOR LLVL MIXING WITH
INVERTED V SUB-INVRN LYR. SINCE H85 TEMPS ARE STILL ARND -15C IN THE
LLVL THERMAL TROF TRAILING THE DEPARTING SHRTWV...LES PERSISTS
MAINLY IN THE NW SN BELTS. BUT THE INTENSITY OF THIS ACTIVITY IS
DIMINISHING WITH FAIRLY HI SFC DEWPT DEPRESSIONS AND THE FLOW
TENDING TOWARD MORE ACYC UNDER THE NEGATIVE DYNAMICS. FARTHER
UPSTREAM...THERE IS A SHRTWV NEAR LK WINNIPEG MOVING ESEWD. BUT THE
AIRMASS IS SO DRY IN THIS AREA NOTHING BUT HI CLDS MARK THE PRESENCE
OF THIS FEATURE.
MAIN FCST CONCERNS THRU SUN ARE CLD TRENDS TNGT/IMPACT ON TEMPS.
TNGT...AS HI PRES BUILDS SLOWLY ACRS WI/UPR MI TNGT UNDER CONFLUENT
WNW FLOW ALF AND THE FLOW BACKS MORE TO THE W...EXPECT LINGERING LES
TO SHIFT INTO AREAS FAVORED BY THAT FLOW AND DIMINISH. WITH THE
BACKING FLOW...SUSPECT THE BULK OF THE LO CLD IN NRN MN WILL DRIFT
TO THE N OF UPR MI AS SHOWN BY THE 12Z LOCAL WRF-ARW MODEL. BUT
THESE CLDS MAY BE MORE PERSISTENT OVER THE KEWEENAW WITH FAVORABLE
UPSLOPE WIND COMPONENT DOWN THE LENGTH OF WRN LK SUP AND E OF
MUNISING WITH A LATER BACKING OF THE FLOW. EVEN THOUGH SOME OF THE
HI CLDS ASSOCIATED WITH THE DISTURBANCE NEAR LK WINNIPEG MAY DRIFT
OVER THE CWA LATER TNGT AS THIS SHRTWV MOVES INTO NRN MN TOWARD
12Z...LGT WINDS/PWAT IN THE 0.15-0.20 INCH RANGE SUPPORT GOING FCST
MIN TEMPS TOWARD THE LO END OF GUIDANCE OVER AT LEAST THE INTERIOR W
HALF.
SUN...AS THE SFC HI PRES RDG DRIFTS INTO LOWER MI...THE LLVL FLOW
OVER UPR MI WL SHIFT TO THE SW...SO ANY LINGERING LK CLDS WL PUSH
OUT INTO LK SUP. WITH A GOOD DEAL OF STRONGER LATE FEB SUNSHINE TO
HEAT THIS DRY AIRMASS AND H85 TEMPS PROGGED TO REACH -5C TO -7C BY
00Z MON...EXPECT A HEALTHY DIURNAL TEMP RECOVERY TO PUSH MAX TEMPS
WELL INTO THE 30S AT MOST PLACES. AREAS OVER THE E CLOSER TO THE
DEPARTING H85 THERMAL TROF AND UNDER A SW FLOW OFF THE CHILLY WATERS
OF LK MI WL BE COLDEST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 342 PM EST SAT FEB 18 2012
SHORTWAVE RIDGE AND SFC HIGH PRESSURE RESULTS IN BENIGN WEATHER
SUNDAY NIGHT INTO MONDAY. GOOD AGREEMENT THAT SFC RIDGE AXIS WILL
RUN FM SOUTHERN WI THROUGH NORTHERN LOWER MICHIGAN AND INTO
SOUTHWEST QUEBEC BY DAYBREAK MONDAY. EXPECT LOWEST TEMPS ON SUNDAY
NIGHT OVER INLAND SOUTHERN AND EASTERN CWA CLOSER TO THE RIDGE AND
LIGHTER WINDS. BIAS CORRECTED GFS MOS LOOKED BEST...BUT DID SOME
ADDITIONAL TWEAK DOWN OF TEMPS OVR INLAND EAST.
ATTN ON MONDAY TURNS TO PAIR OF SHORTWAVE TROUGHS THAT WILL BE
PUSHING FM THE ROCKIES EAST INTO THE CNTRL AND NORTHERN PLAINS.
GFS/ECMWF/CANADIAN INDICATE TWO DISTINCT TROUGHS IN THE PV FIELDS
AND THIS STAYS THE CASE RIGHT THROUGH TUESDAY AS THE TROUGHS MOVE
ACROSS UPR LAKES. MAIN ISSUE ON MONDAY IS INCREASING MID CLOUDS OUT
AHEAD OF UPR TROUGHS. DESPITE CHILLY START...SHOULD BE ANOTHER WARM
AFTN AS MIXING TO 925MB-900MB SUPPORTS HIGHS WELL INTO THE 30S.
EXPECT NO PRECIP INTO WESTERN CWA BY 00Z TUE. NAM IS SIGNIFICANT
OUTLIER BY LIFTING WELL DEFINED H85 CLOSED LOW INTO NORTHERN MN/QPF
INTO FAR WESTERN UPR MI BY LATE TUESDAY AFTN. ALL OTHER GUIDANCE HAS
MORE OF AN ELONGATED TROUGH FM NEB INTO NW MN AND CONTINUE TO TREND
SLOWER IN ARRIVAL OF QPF OVR CWA UNTIL LATER MONDAY NIGHT. HAVE
DISCOUNTED THE NAM AND TRENDED TOWARD OTHER MODELS FOR ARRIVAL OF
PRECIPITATION.
INTO TUESDAY...MAIN DIFFERENCE IS THAT GFS IS MORE PHASED WITH H85
TROUGHS AND HAS MORE MOISTURE ADVECTION INTO THE UPR LAKES. EVEN THE
GFS SHOWS THE PRIMARY JET STREAM REMAINING ACROSS THE SOUTHERN TIER.
ECMWF AND CANADIAN OFFER MORE TONED DOWN GFS IDEA BUT THEY ARE
SHOWING MORE PHASING OF H85 TROUGHS THAN THEY DID EARLIER. RESULT IS
MAIN MOISTURE STREAM/HIGHER PWATS STAYING TIED INTO SOUTHERN STREAM
SHORTWAVE TRACKING ACROSS OHIO VALLEY INTO CNTRL GREAT LAKES WHILE
UPR LAKES/UPR MICHIGAN IS WITHIN REMNANTS OF DEEPER MOISTURE BEING
ADVECTED INTO THE NORTHERN STREAM SYSTEM. LIMITED LARGE SCALE
PHASING ALLOWS WARMER AIR TO REMAIN TO SOUTH SO SNOW WILL BE MAIN
PTYPE. ONLY EXCEPTION IS ALONG IMMEDIATE LK MICHIGAN SHORE WHERE A
MIX OF RAIN/SNOW WAS MENTIONED WITH ONSHORE WINDS. BASED ON MAX
TEMPS INTO MID 30S CONSIDERED ADDING RAIN MENTION ELSEWHERE...BUT
WBZERO HEIGHTS LESS THAN 500AGL WOULD LEAD TO ONLY BRIEF MIXING WITH
RAIN BEFORE SNOW TAKES OVER AS MAIN PYTPE.
INCREASED POPS INTO THE LIKELY RANGE FOR TUESDAY...ESPECIALLY FIRST
PART OF DAY ON TUESDAY OVER WEST AS THAT IS WHEN THE TWO MOISTURE
STREAMS WITH THE SHORTWAVES ARE IN GREATEST PROXIMITY.
HOWEVER...BASED ON THE GENERAL DOWNWARD TREND TO MOISTURE/LIFT AS
TUESDAY GOES ON...IN ADDITION TO FAIRLY WARM BLYR TEMPS IN THE
LOWER-MID 30S...PROBABLY WILL NOT BE MUCH FOR SNOW ACCUMS OVER UPR
MI FOR MOST OF THE DAYLIGHT HOURS ON TUESDAY. POSSIBLE EXCEPTION
WOULD BE IN THE FAR WEST DURING THE MORNING WHERE A FEW INCHES OF
SNOW COULD OCCUR VCNTY OF KIWD.
BASE OF NORTHERN STREAM TROUGH SETTLES CLOSE BY ON TUESDAY NIGHT
WHILE THERE IS STILL LINGERING H85-H7 MOISTURE IN WAKE OF SYSTEM THAT
MOVES THROUGH ON TUESDAY. GIVEN THE SETUP...CANNOT RULE OUT SMALL
SHORTWAVES ROUNDING BASE OF TROUGH THAT DO NOT SHOW UP IN GUIDANCE
RIGHT NOW. CARRIED SMALL CHANCE POPS FOR LGT SNOW SHOWERS/FLURRIES...
ESPECIALLY OVER KEWEENAW WHERE WEST WINDS PROVIDE A BIT MORE
MOISTENING OFF LAKE SUPERIOR.
IN THE EXTENDED...SFC-H85 LOW IS FCST TO BE NORTH OF LK SUPERIOR ON
WEDNESDAY. 00Z ECMWF MORE AMPLIFIED WITH SMALLER H85 LOW SLIDING
ACROSS IN WESTERLY FLOW WHICH WOULD LEAD TO SWATH OF SYNOPTIC SNOW
OVR PORTIONS OF THE CWA ON WEDNESDAY. ECMWF IDEA SEEMS LIKE LOW RISK
AT THIS POINT AS PREVIOUS RUNS DID NOT HAVE THIS AND OTHER MEDIUM
RANGE MODELS DO NOT SHOW IT AS WELL. INSTEAD WILL GO WITH IDEA THAT
MAINLY QUIET CONDITIONS WILL BE AROUND ON WEDNESDAY IN WAKE OF
TUESDAY SYSTEM. UPR TROUGH EVENTUALLY SLIDES THROUGH UPR LAKES LATER
WEDNESDAY NIGHT INTO THURSDAY...USHERING IN COLDER AIR TO END THE
WEEK. CYCLONIC FLOW WITHIN THE SFC-H5 TROUGHINESS ALLOWS DEEPER
MOISTURE TO HANG AROUND THURSDAY INTO THURSDAY NIGHT. GIVEN COLD AIR
ADVECTION AND THE MOISTURE...PROBABLY WILL SEE ACCUMULATING SNOWS
FOR AREAS NEAR LK SUPERIOR FAVORED BY NW WINDS. DRYING FCST TO
SPREAD IN FM NW ON FRIDAY AS UPR LOW CENTER SLIDES EAST. DOES COOL
OFF SLIGHTLY COMPARED TO THURSDAY THOUGH...SO WOULD EXPECT LK EFFECT
TO CONTINUE IN NW FLOW AREAS WITH MAINLY LGT ACCUMS. SAME GOES FOR
FRIDAY NIGHT INTO SATURDAY AS SFC-H85 RIDGE IS STUBBORN TO ARRIVE FM
THE WEST. KIND OF A CHANGE FROM THE QUICK-MOVING PATTERN THAT HAS
BEEN PRESENT OVER THE REGION FOR MOST OF THE WINTER. MAIN CHANGE TO
EXTENDED WAS TO INCREASE POPS FOR LK EFFECT AREAS COMPARED TO WHAT
ALLBLEND PROCEDURE GENERATED. AWAY FM THE LAKE EFFECT...EXPECT
MAINLY CLOUDY CONDITIONS WITH NEAR NORMAL TEMPS FOR LATER FEBRUARY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1231 AM EST SUN FEB 19 2012
DRY LOW-LEVELS ASSOCIATED WITH HIGH PRESSURE RIDGE DRIFTING ACROSS
THE WESTERN GREAT LAKES WILL ENSURE VFR CONDITIONS AT KIWD/KSAW THRU
THIS FCST PERIOD. WITH A WESTERLY UPSLOPE WIND/CONTINUED OVERWATER
TRAJECTORY...OCNL MVFR CIGS MAY STILL OCCUR AT KCMX OVERNIGHT.
OTHERWISE...VFR CONDITIONS WILL PREVAIL TODAY AND TONIGHT AT KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 342 PM EST SAT FEB 18 2012
WITH AN UNSEASONABLY WEAK PRES GRADIENT FORECAST TO DOMINATE THE
UPPER GREAT LAKES THIS COMING WEEK...EXPECT WINDS NO HIGHER THAN
25 KTS THIS FORECAST PERIOD. NO GALES ARE LIKELY ANYTIME SOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
834 PM CST MON FEB 20 2012
.UPDATE...
ISSUED AT 834 PM CST MON FEB 20 2012
MADE SOME ADJUSTMENTS TO GOING FORECAST TO INCLUDE ISOLATED THUNDERSTORMS
OVER CENTRAL AND SOUTHEAST MISSOURI THIS EVENING...AND ADJUSTED POPS
BASED ON GOING RADAR OBSERVATIONS. LINE OF SHOWERS AND SCATTERED
THUNDERSTORMS ACROSS SOUTHWEST AND WEST CENTRAL MISSOURI THAT
PRODUCED ISOLATED SEVERE WIND GUSTS EARLIER CONTINUES TO MOVES
NORTHEAST THIS EVENING AND WILL LIKELY MOVE INTO CENTRAL AND
NORTHEAST MISSOURI BETWEEN 9-10PM. WHILE THE INTENSITY OF THE
THUNDERSTORMS SHOULD DECREASE AS IT MOVES INTO DRIER
AIR...STRENGTH OF ASCENT WITH NEGATIVELY TILTING UPPER TROUGH AND
DECENT 925-850MB MOISTURE CONVERGENCE SHOULD KEEP THE LINE OF
SHOWERS GOING. RADAR INTERPOLATION AND HRRR FORECAST REFLECTIVITY
SUGGESTS THAT THIS LINE OF SHOWERS WILL CONTINUE TO MOVE EAST AND
LIKELY EXIT THE CWA BY 3 AM. I HAVE ADDED ISOLATED THUNDERSTORMS
TO PARTS OF CENTRAL AND SOUTHEAST MISSOURI THIS EVENING BASED ON
THE STRENGTH OF THE ASCENT AND WEAK INSTABILITY SEEN IN THE RUC.
REST OF THE FORECAST STILL LOOKS GOOD.
BRITT
&&
.SHORT TERM...
ISSUED AT 239 PM CST MON FEB 20 2012
(TONIGHT)
MID AND HIGH CLOUDS MOVING INTO FORECAST AREA THIS AFTERNOON AHEAD
OF NEXT WEATHER SYSTEM. SOME SHOWERS HAVE DEVELOPED OVER WESTERN
MO AHEAD OF COLD FRONT...BUT MAKING VERY LITTLE PROGRESS TO THE
EAST YET UNTIL SHORTWAVE BEGINS TO LIFT OUT. SO BACKED OFF ON ONSET
OF PCPN WITH RAIN MOVING INTO CENTRAL MO BY 01Z...ALONG
MISSISSIPPI RIVER BY 04Z AND EASTERN PORTIONS OF FORECAST AREA BY
06Z. MODELS SHOWING LITTLE IN THE WAY OF INSTABILITY WITH THIS
SYSTEM OVER OUR AREA...SO REMOVED MENTION OF THUNDERSTORMS. ONCE
THIS SYSTEM BEGINS TO MAKE SOME PROGRESS TO THE EAST ONLY EXPECT
IT TO RAIN FOR A FEW HOURS MOST LOCATIONS...WITH ONLY A TENTH OF
AN INCH OF QPF...BEFORE COMING TO AN END TOWARDS DAYBREAK. AS FOR
LOW TEMPS...INITIALLY COLD AIR LAGGING BEHIND THIS SYSTEM...SO
LOWS TO ONLY DIP INTO THE UPPER 30S TO AROUND 40.
BYRD
&&
.LONG TERM...
ISSUED AT 350 PM CST MON FEB 20 2012
(TUESDAY THROUGH NEXT MONDAY)
THE LONGWAVE UPPER LEVEL TROF IS EXPECTED TO STILL SETTLE IN FOR
MUCH OF THE WORK WEEK BEGINNING TUESDAY AND MAINTAINING ITSELF UNTIL
FRIDAY WITH A FEW GENERALLY WEAK SHORTWAVES SWINGING THRU. THIS
WILL SCOOT A FEW FRONTS THRU AT A FRANTIC PACE BUT MOISTURE WILL BE
PRETTY LIMITED DURING THIS TIME ALTHOUGH IT APPEARS UPPER LEVEL
IMPULSE ON THURSDAY SHOULD BE STRONG ENOUGH WITH ENOUGH MOISTURE TO
WARRANT CONTINUED MENTION OF CHANCE POPS. FAIRLY DEEP MIXING
TUESDAY THRU THURSDAY WILL RESULT IN CONTINUED MILD TEMPS FOR LATE
FEBRUARY...WITH WARMEST MOS VALUES FAVORED...RESULTING IN 50S AND
SOME 60S FOR MAXES. AND TUESDAY/S VALUES ARE DESPITE CDFNT MOVING
THRU LATER TONIGHT...AS RESULTANT TEMPS WILL BE NEARLY IDENTICAL...
PERHAPS A TAD HIGHER...THAN PERSISTENCE.
NWLY UPPER LEVEL FLOW COUPLED WITH HI PRES INVOF THE FA WILL RESULT
IN QUIET WX FOR MUCH OF THE UPCOMING WEEKEND...WITH TEMPS REBOUNDING
FROM NEAR AVERAGE ON FRIDAY TO ABOVE AVERAGE AGAIN BY SUNDAY. UPPER
LEVEL FLOW SHIFTS SWLY BY NEXT MONDAY WHERE A STORMIER PATTERN
APPEARS IN THE OFFING.
TES
&&
.AVIATION...
ISSUED AT 541 PM CST MON FEB 20 2012
INITIAL LINE OF LIGHT SHOWERS AHEAD OF A WARM FRONT WAS MOVING
THROUGH COU AND SHOULD CONTINUE TO WEAKN AS IT PROGRESSES E-NEWD.
THERE MAY BE A BRIEF PERIOD OF LIGHT RAIN OR JUST SPRINKLES IN UIN
EARLY THIS EVNG...BUT THIS ACTIVITY IS NOT EXPECTED TO MOVE INTO
THE STL METRO AREA THIS EVNG. MORE SIGNIFICANT IS THE LINE OF
SHOWERS AND STORMS OVER ERN KS ASSOCIATED WITH A SFC LOW OVER N
CNTRL KS AND A TRAILING CDFNT. THIS ACTIVITY WILL MOVE THROUGH COU
FROM ABOUT 04-08Z TUE...AND THROUGH THE REST OF THE TAF SITES
AROUND 06-10Z TUE. THIS ACTIVITY SHOULD WEAKEN SOME AS IT MOVES
EWD INTO OUR AREA WITH LITTLE IF ANY THUNDERSTORMS LEFT. CLOUD
CEILINGS SHOULD LOWER INTO THE MVFR CATAGORY LATE TGT AFTER FROPA.
INCLUDED LLWS IN THE STL...SUS AND CPS TAFS LATE THIS EVNG AS A
STRONG S-SWLY LOW LEVEL JET MOVES THROUGH. SELY SFC WINDS WILL BE
GUSTY AND GRADUALLY VEER AROUND TO A SWLY DIRECTION AFTER FROPA
AND A WLY DIRECTION TUE MRNG. THE MVFR CIGS SHOULD SCATTER OUT IN
COU EARLY TUE MRNG AND IN THE REST OF THE TAF SITES LATE TUE MRNG.
SPECIFICS FOR KSTL...A LINE OF SHOWERS WILL MOVE THROUGH STL FROM
ABOUT 06-10Z TUE WITH CLOUD CEILINGS LOWERING...EVENTUALLY INTO
THE MVFR CATAGORY LATE TGT AFTER FROPA. LLWS CAN BE EXPECTED LATE
THIS EVNG WITH THE MODELS FORECASTING THE 2000 FT WIND TO INCREASE
TO AROUND 45 KTS FROM A SLY DIRECTION. SELY SFC WIND SHOULD REMAIN
FAIRLY GUSTY TGT AND TUE GRADUALLY VEERING AROUND TO A SWLY
DIRECTION LATE TGT AND A WLY DIRECTION TUE MRNG. THE MVFR CIG
SHOULD SCATTER OUT BY LATE TUE MRNG. THE SFC WIND WILL DIMINISH TUE
EVNG.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
522 PM CST MON FEB 20 2012
.AVIATION...
00Z TAFS FOR KOFK...KOMA AND KLNK.
UPPER AND SURFACE LOW NEAR THE KS/NEBR BORDER S OF GRI SHOULD MOVE
E INTO NWRN MO BY 06Z. SCATTERED THUNDERSTORMS SPREADING NNE
AHEAD OF SYSTEM WILL MOVE INTO SERN NEBRASKA EARLY THIS EVENING...
AND POSSIBLY FARTHER N BEFORE SYSTEM MOVES OFF TO THE EAST. A
TSTM WAS MENTIONED AT KLNK WITH 00Z TAF ISSUANCE WITH A CB
MENTION AT KOMA. OTHERWISE IFR CIGS COULD IMPROVE AS DRY SLOT JUST
AHEAD OF CONVECTION LIFTS TOWARD KLNK BUT UNLIKELY FARTHER N AT
KOMA AND ESPECIALLY AT KOFK UNTIL SEVERAL HOURS AFTER FRONTAL
PASSAGE LATER THIS EVENING. BRIEFLY GUSTY WINDS COULD OCCUR BEHIND
FRONT AND LOW CLOUDS SHOULD CLEAR EASTERN NEBRASKA BY 12Z OR SO.
SOME SNOW COULD MIX IN WITH PRECIP BEFORE IT ENDS AND A MIX WAS
INCLUDED AT KOFK.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 340 PM CST MON FEB 20 2012/
SHORT TERM...TONIGHT THROUGH THURSDAY.
THE MAIN CONCERNS IN THE SHORT TERM WILL BE THE COVERAGE OF THE
PRECIPITATION THAT RE-DEVELOPS AND PRECIP
TYPE...CONVECTION...RAIN/SNOW MIX.
THE 12Z UPPER AIR CHARTS SHOWED A 110+KT JET OVER NEW MEXICO
ROUNDING THE BASE OF THE TROF. THE H5 LOW WAS OVER NORTHEAST
COLORADO WITH 130M HEIGHT FALLS AT DENVER. THE H7 LOW WAS NEAR KLBF
WITH H7-H5 LAPSE RATES OF 7.5 DEG C/KM AHEAD OF THE H7 LOW. THE H85
LOW WAS NEARLY VERTICALLY STACKED BTWN RAPID CITY AND NORTH PLATTE.
BOTH DDC AND OMA REPORTED 50KT H85 WINDS. AT MIDDAY...THE SURFACE
MAP HAD SFC LOW PRESSURE NEAR LEXINGTON AND PER THE VISIBLE
STLT...THERE WAS NOTICEABLE CLEARING JUST AHEAD OF THE SFC LOW. SFC
TEMPERATURES RANGED FROM THE MID 30S IN THE NORTH TO THE MID AND
UPPER 40S TOWARD FAIRBURY AND FALLS CITY. THE WSR-88D RADAR MOSAIC
LOOP FROM THIS MORNING AND METARS SHOWED THAT TEMPERATURES WARMED
ABOVE FREEZING...HOWEVER SNOW AND SLEET DID MOVE ACROSS THE NORFOLK
AND WAYNE AREAS WITH VSBYS DOWN TO 2SM. 6HR PRECIPITATION
AMOUNTS THROUGH 18Z WERE LIGHT...GENERALLY .15 OR LESS. THERE WERE
A FEW LIGHTNING STROKES NEAR BVN/OLU/OFK. BY 19Z...THE BULK OF THE
PRECIPITATION HAD SHIFTED NORTH AND EAST OUT OF EASTERN
NEBRASKA...WITH THE NORTH TO SOUTH BAND ACROSS WRN IOWA. OUTSIDE OF
OUR AREA...WEST OF THE SURFACE LOW IN WESTERN NEBRASKA...SNOW WAS
FALLING...MODERATE TO HEAVY AT TIMES FROM VALENTINE TO IMPERIAL.
AT 21Z...A NARROW LINE OF CONVECTION WAS DEVELOPING ACROSS CENTRAL
KANSAS...WITH A FEW WARNINGS BEING ISSUED. THIS CONVECTION IS
PROGRESSING NORTH AND EAST. AT 00Z THE THETA-E AXIS IS PROGGED TO
STRETCH FROM ERN NEB INTO ERN KANSAS AND ZERO OR LOWER BEST
LIFTED INDEX VALUES ARE OVER THE NEB/KS BORDER AHEAD OF THE SFC
LOW. THE LATEST HRRR TENDS TO TAKE THE BETTER CONVECTION SOUTH OF
THE FORECAST AREA...HOWEVER...DID INCLUDE THUNDERSTORM MENTION
OVER THE SOUTHEAST NEB WITH DRIZZLE OR LIGHT RAIN FARTHER
NORTH...AND A MIX OF RAIN/SNOW MOVING EAST DURING THE EVENING.
THE RUC AND 18Z NAM SHOW THE BAND OF SNOW WEAKENING AS IT MOVES
INTO THE FORECAST AREA...HOWEVER THERE MAY BE ENOUGH
OMEGA/FRONTOGENESIS/DEPTH OF COLD AIR TO SWITCH IT OVER TO LIGHT
SNOW. DID INCLUDE SOME MINOR SNOW AMOUNTS IN PARTS OF ECNTRL/NE
NEB TO ACCOUNT FOR THIS. TREND AFTER 06Z IS FOR THE SYSTEM TO BE
MOVING OUT...WITH WESTERLY FLOW FOR TUESDAY.
LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT...NORTHWEST FLOW ALOFT
WILL BRING MODERATE TEMPERATURES AND VARIABLE CLOUDS. THE MODELS
HAVE SOME DIFFERENCES ON THE CHC FOR PRECIPITATION DURING THIS
PERIOD. FOR NOW INCLUDED SOME SPRINKLES WEDNESDAY AND WITH THE
COLDER AIR WEDNESDAY NIGHT AND THURSDAY...A RAIN SNOW MIX IN THE
NORTH.
ZAPOTOCNY
LONG TERM...THURSDAY NIGHT THROUGH MONDAY.THE LONG TERM PERIOD
WILL BEGIN WITH AN UPPER TROUGH OVER THE GREAT LAKES AND THE
EASTERN NORTHERN PLAINS. A SHORTWAVE SHOULD BE EXITING OUR AREA
THURSDAY NIGHT SO WILL MAINTAIN A DRY FORECAST THEN. ANOTHER
SHORTWAVE LOOKS TO DROP THROUGH THE NORTHWEST FLOW ON BACK SIDE OF
UPPER TROUGH ON FRIDAY...WITH MODELS SHOWING VARYING DEGREES OF
INTENSITY AND LOCATION. GFS IS THE STRONGEST AND FARTHEST
WEST...WHICH WOULD BRING A CHANCE FOR LIGHT SNOW TO OUR
AREA...WHILE ECMWF/CANADIAN TRACK SHORTWAVE TO OUR EAST. WILL STAY
WITH MAJORITY OF MODEL SOLUTIONS WHICH MATCH OUR CURRENT DRY
FORECAST. HOWEVER ALL SOLUTIONS SUGGEST A RATHER CHILLY DAY FRIDAY
AS AT LEAST MODERATE COLD ADVECTION SHOULD KEEP HIGHS IN THE 30S.
A WARMING TREND STILL LOOKS ON TAP FOR THE WEEKEND AS UPPER FLOW
BECOMES MORE ZONAL IN WAKE OF EXITING UPPER TROUGH AND AHEAD OF
LOWERING HEIGHTS ALONG THE WEST COAST. AGAIN TODAY MODELS HAVE
DIFFERING OPINIONS ON TIMING AND EXTENT OF WARMING BASED ON
DIFFERING UPPER FLOW SOLUTIONS. FOR THE MOST PART...ALL MODELS SHOW
LOWERING HEIGHTS IN THE WEST...BUT SOME ARE HINTING AT A SIGNIFICANT
PIECE OF ENERGY MOVING FROM THE ROCKIES ACROSS THE PLAINS ON SUNDAY.
GFS IS THE MOST BULLISH IN THIS REGARD...AND HAS NOT WAVERED FROM
RUN TO RUN. HOWEVER...GFS ENSEMBLE MEMBERS ARE SPLIT...WITH A
PLURALITY LEANING TOWARD A 00Z ECMWF SOLUTION KEEPING MORE ENERGY
DROPPING INTO THE SOUTHWEST STATES AND MAINTAINING ZONAL OR
SOUTHWEST FLOW ALOFT IN THE PLAINS THROUGH SUNDAY. THE NEW 12Z ECMWF
MAINTAINS THIS PHILOSOPHY...SO HAVE SIDED WITH THIS THOUGHT FOR THE
WEEKEND.
USING ECMWF...HIGHS SATURDAY SHOULD REBOUND BACK INTO THE
40S BUT SUNDAY IS STILL IN QUESTION. BAROCLINIC ZONE LOOKS TO SET UP
NORTH TO SOUTH ACROSS OUR CWA WITH THE 0C 850 LINE NEAR INTERSTATE
80. STRONG ISENTROPIC UPGLIDE WILL COMMENCE SUNDAY AFTERNOON UNDER
COUPLED JET STRUCTURE...SUGGESTING LIFT OVER BAROCLINIC ZONE COULD
LEAD TO PRECIPITATION IN OUR NORTH. THICKNESSES SUPPORT SNOW
THERE...BUT WARM LOW LEVEL TEMPS COULD CHANGE THAT TO RAIN. SO A MIX
OF PRECIP WILL BE ADDED TO FORECAST SUNDAY. CLOUDS AND
PRECIPITATION CHANCES WILL LIKELY LIMIT HIGHS TO THE 30S IN OUR
NORTH. THIS TREND CONTINUES INTO MONDAY AS SURFACE LOW TRACKS TO OUR
SOUTH...MAINTAINING BAROCLINICITY ACROSS OUR AREA WITH A NORTHWEST
TO SOUTHEAST ORIENTATION. TRACK OF LOW PUTS OUR SOUTHEAST CWA IN
FAVORABLE AREA FOR RAIN THEN...WITH HIGHS RANGING FROM THE 20S OR
LOWER 30S NORTHWEST TO THE UPPER 30S SOUTHEAST. THERE IS A LOT OF
ROOM FOR ERROR SUNDAY AND MONDAY GIVEN PROXIMITY OF BAROCLINIC
ZONE...SO RELATIVELY LOW CONFIDENCE FORECAST AT THIS TIME.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
418 PM CST SUN FEB 19 2012
.SHORT TERM...TONIGHT AND MONDAY. PRIMARY FORECAST CONCERN LIES WITH
PRECIPITATION CHANCES.
BEEN A QUIET DAY TODAY...WITH UPPER AIR PROFILER AND SATELLITE
DATA SHOWING THE REGION REMAINING UNDER THE INFLUENCE OF
SHORTWAVE RIDGING...BETWEEN A TROUGH OVER THE MIDWEST AND ANOTHER
TROUGH DIGGING INTO THE DESERT SOUTHWEST. WINDS HAVE GRADUALLY
BECOME MORE SOUTHERLY AND INCREASED IN SPEED THROUGH THE
DAY...THANKS TO DEVELOPING LOW PRESSURE OVER THE ROCKIES AND HIGH
PRESSURE EXTENDING THROUGH THE GREAT LAKES AND DOWN TOWARD ERN TX.
THAT BAND OF LOW LEVEL STRATUS DRAPED FROM NRN NEB SOUTH INTO TX
DID DRIFT A TOUCH FURTHER EAST EARLIER THIS AFTERNOON...AND HAS
STALLED OUT WITH SATELLITE IMAGERY SHOWING IT SHRINKING IN
SIZE...BUT STILL KEEPING WRN AREAS MOSTLY CLOUDY.
LOOKING TO TONIGHT AND TOMORROW...THE MAIN STORY REMAINS WITH THAT
TROUGH DIGGING INTO THE DESERT SOUTHWEST AND ITS EVENTUAL ARRIVAL
ONTO THE PLAINS. OVERNIGHT...MODELS IN PRETTY GOOD AGREEMENT
SHOWING A CLOSED CIRCULATION DEVELOPING WHILE SHIFTING EAST...AND
BY 12Z TOMORROW...THE 500MB LOW LOOKS TO BE CENTERED OVER
CENTRAL/ERN COLORADO...WITH THE 700MB LOW A TOUCH FURTHER NEAST.
AHEAD OF THIS SYSTEM...SFC LOW PRESSURE CONTINUES TO BECOME BETTER
ORGANIZED AND DRIFTS NEAR THE CO/KS/NEB BORDER AREA BY 12Z
TOMORROW...BRINGING INCREASED S/SERLY WINDS TO THE CWA OVERNIGHT.
ALONG WITH THE WINDS...EXPECTING TO SEE INCREASED ISENTROPIC
LIFT...AS WELL AS INCREASED WARM AIR/MOISTURE ADVECTION...WITH
MODELS IN GOOD AGREEMENT SHOWING A SRLY LLJ CRANKING UP /45 TO
NEAR 60 KTS DEPENDING ON THE MODEL/. THIS IS EXPECTING TO RESULT
IN INCREASED PRECIPITATION CHANCES ACROSS THE CWA...MAINLY AFTER
MIDNIGHT AND ACROSS THE NORTHEASTERN 2/3RDS OF THE CWA. KEPT THE
MENTION OF ISOLATED THUNDER GOING IN THE FORECAST WITH MODELS IN
DECENT AGREEMENT SHOWING SOME INSTABILITY PRESENT...THE NAM IS
CERTAINLY THE MORE AGGRESSIVE OF THE MODELS SHOWING A 1-2 J/KG IN
SOME AREAS...WITH OTHER MODELS LESS THAN 100 J/KG. THINK THAT
OVERNIGHT LOWS WILL COME EARLIER ON IN THE NIGHT...THAT INCREASING
CLOUD COVER AND S/SERLY WINDS WILL HELP TO STEADY OUT TEMPS...AND
BY THE TIME PRECIPITATION CHANCES INCREASE THE TEMPS ARE EXPECTED
TO BE ABOVE FREEZING...BUT NOT BY MUCH...ESP IN SOME NEAST
LOCATIONS.
AS WE GET INTO TOMORROW...MODELS REMAIN IN PRETTY GOOD AGREEMENT
WITH THE MAIN SYSTEM...SHOWING THE LOW SHIFTING BASICALLY STRAIGHT
EAST RIGHT INTO OUR NC KS COUNTIES BY 00Z. MAIN CHANGE MADE TO
THE FORECAST WAS TO SHOW A NORTHWARD SHIFT OF THE MORNING
PRECIPITATION CHANCES AS THE NOSE OF THE LLJ CONTINUES PUSHING
NORTH AND DRIER MID LEVEL AIR WORKS ITS WAY IN FROM THE SOUTH.
HAVE THUNDERSTORM MENTION DIMINISHING IN THE MORNING...AND THEN
LOWERED POPS A BIT AND HAVE THE POTENTIAL FOR DRIZZLE WORKING ITS
WAY IN FROM S TO N ACROSS THE ENTIRE CWA. THEN PRECIPITATION
CHANCES PICK UP AGAIN DURING THE AFTERNOON HOURS AS THE SYSTEM
SHIFTS CLOSER. THROUGH THE AFTERNOON HOURS...MODELS SHOWING THE
SFC/UPPER LEVEL LOWS MOVING INTO NC KS...WITH A COLD FRONT
STARTING TO MOVE INTO WRN PORTIONS OF THE CWA...AND SOME DRIER AIR
SHIFTING IN FROM THE SOUTH. ON THE BACKSIDE OF THE SYSTEM ACROSS
THE NW PORTION OF THE CWA...COULD START TO SEE A MIX OF RA/SN AS
COOLER AIR STARTS TO WORK IN...BUT NOT EXPECTING MUCH SN
ACCUMULATION. ACROSS THE REMAINDER OF THE CWA...AND ESP THE SERN
THIRD OR SO...PTYPE REMAINS LIQUID...AND THE POSSIBILITY OF
THUNDERSTORMS RETURNS. MODELS IN GOOD AGREEMENT SHOWING INCREASED
LOW/MID LEVEL LAPSE RATES /500MB TEMPS NEAR -30C/ DURING THE
AFTERNOON. AGAIN THE NAM IS THE MOST AGGRESSIVE WITH THINGS...EVEN
SHOWING INSTABILITY APPROACHING 900 J/KG...WITH OTHER MODELS NOT
REALLY EVEN CLOSE TO THAT...MORE ON THE ORDER OF 1-200 J/KG OR SO.
AM SIDING WITH THE LOWER VALUES WHICH HAS MORE SUPPORT. WITH THE
SYSTEM PASSING RIGHT THROUGH NC KS...SOME INSTABILITY AND STEEPER
LAPSE RATES PRESENT...AT LEAST SOME ISOLATED THUNDERSTORMS ARE
POSSIBLE...AND CANT COMPLETELY RULE OUT A STRONGER CELL OR TWO
DROPPING SOME SMALL HAIL...AND WILL MENTION IN THE HWO.
TEMPERATURES ARE TRICKY...AM EXPECTING PLENTY OF CLOUD COVER TO BE
PRESENT...BUT IF SOME AREAS MANAGE TO SEE MORE SUN /MAINLY THE
SOUTH/...FORECAST HIGHS ARE LIKELY TOO LOW. CURRENTLY CALLING FOR
UPPER 30S IN THE NW TO UPPER 40S IN THE SE. AS FAR AS WINDS
GO...WITH THE FRONT PASSING THROUGH...DIRECTION WILL BE
TRANSITIONING FROM THE S/SE TO THE NW...AND THROUGH THE MID/LATE
AFTERNOON HOURS...WRN AREAS BEHIND THAT FRONT COULD BE FAIRLY
GUSTY AT TIMES.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY. WILL HAVE TO WATCH OUT
FOR SOME RAIN MIXED WITH SNOW MONDAY EVENING AND THEN WE CAN
EXPECT FAIRLY DRY CONDITIONS THEREAFTER...ALTHOUGH A FEW VERY
LIGHT PRECIPITATION EVENTS CAN NOT BE RULED OUT.
MONDAYS STORM SYSTEM WILL BE ON ITS WAY OUT OF THE REGION MONDAY
EVENING...BUT RAIN COULD MIX WITH OR TURN OVER TO SNOW DURING THE
EVENING HOURS ON THE BACK SIDE OF THE SYSTEM. COLDER AIR WILL
FUNNEL IN BEHIND THE SFC LOW MAKING A BRIEF CHANGE OVER TO SNOW
POSSIBLE. HOWEVER...EVEN IF RAIN CAN CHANGE OVER TO SNOW PRIOR TO
ENDING...IT LIKELY WILL NOT LAST LONG DUE TO THE VERY PROGRESSIVE
NATURE OF THIS SYSTEM. CONSEQUENTLY...LITTLE TO NO SNOWFALL
ACCUMULATION IS EXPECTED AT THIS TIME FOR MOST AREAS.
TUESDAY...TEMPERATURES WILL BE QUICK TO MODERATE TUESDAY AFTERNOON
WITH DOWNSLOPE WESTERLY WINDS HELPING HIGH TEMPERATURES CLIMB INTO
THE 40S ACROSS NEBRASKA WITH 50S OVER NORTHERN KANSAS.
WEDNESDAY WILL CONTINUE TO BE A DRY DAY WITH PERSISTENT WESTERLY
DOWNSLOPE WINDS PUSHING HIGHS INTO THE UPPER 40S TO AROUND 50 OVER
SOUTHERN NEBRASKA...TO THE UPPER 50S TO AROUND 60 ACROSS NORTHERN
KANSAS.
WEDNESDAY NIGHT INTO THURSDAY...A COLD FRONT WILL PUSH THROUGH
WEDNESDAY NIGHT INTO THURSDAY AND MAY RESULT IN TRACE AMOUNTS OF
RAIN OR SNOW...BUT MOST AREAS WILL REMAIN DRY. HIGH TEMPERATURES
ON THURSDAY SHOULD COOL BACK INTO THE 40S.
FRIDAY THROUGH SUNDAY...OVERALL FLOW PATTERN REMAINS PROGRESSIVE
WITH SEASONAL TEMPERATURES EXPECTED. WILL KEEP THINGS DRY FOR
NOW..BUT WILL NEED TO WATCH FOR THE POSSIBLE DEVELOPMENT OF A
STORM SYSTEM ACROSS THE WESTERN CONUS BY SUNDAY. AT THIS
TIME...IT SEEMS THAT SHOULD THIS STORM DEVELOP IT WOULD STILL NOT
ARRIVE IN THE PLAINS REGION UNTIL MONDAY.
&&
.AVIATION...18Z TAF. PRIMARY FORECAST CONCERNS FOR THIS TAF PERIOD
LIE WITH THE IMPACT OF ONGOING STRATUS AND PRECIPITATION CHANCES
LATER IN THE PERIOD. BAND OF LOW LEVEL STRATUS EXTENDING FROM TX
NORTH THROUGH NEB HAS CONTINUED TO GRADUALLY SHIFT EAST THIS
MORNING...AND THE TERMINAL CURRENTLY SITTING RIGHT OUTSIDE ITS
EASTERN FRINGE. RUC SEEMS TO BE DOING THE BEST JOB WITH WHAT HAS
BEEN GOING ON...AND WITH IT SHOWING THIS CLOUD COVER EVEN GOING A
BIT FURTHER EAST...WILL PUT MVFR CIGS IN THE TAF THROUGH MID
AFTERNOON. IT IS POSSIBLE THE TERMINAL WILL REMAIN ON THE FRINGE
AND HAVE SCT INSTEAD OF BROKEN CIGS...WILL MONITOR AND ADJUST
ACCORDINGLY. FOCUS THEN TURNS TO OVERNIGHT/INTO MONDAY
MORNING...AS AN UPPER LEVEL SYSTEM MOVES OUT OF THE ROCKIES. LOOKS
LIKE THE BETTER CHANCES FOR PRECIPITATION AT THE TERMINAL WILL
COME BETWEEN ROUGHLY 10-15Z...AND WITH A STRONG LLJ AND SOME
INSTABILITY...KEPT THE CB MENTION GOING WITH SHOWERS. NOT
CONFIDENT ENOUGH IN THE TERMINAL SEEING A TS TO PUT AS PREVAILING.
FOR MID/LATE MORNING...BETTER CHANCES LOOK TO SHIFT NORTH WITH
POTENTIAL FOR DZ BUILDING IN. START THE MORE DETERIORATING CIGS
ALREADY AT MIDNIGHT AND CONTINUE THROUGH THE REMAINDER OF THE TAF
PERIOD WITH VISIBILITIES DROPPING WITH THE ONSET OF PRECIPITATION.
WITH THE MAIN SURFACE REMAINING W/SW OF THE TERMINAL...WINDS
CONTINUE OUT OF THE SOUTH...EVENTUALLY BECOMING MORE SE WITH TIME.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT/AVIATION...ADO
LONG...WESELY
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
933 AM EST SUN FEB 19 2012
.SYNOPSIS...
A QUICK MOVING LOW PRESSURE SYSTEM OVER THE NORTHEAST THIS MORNING
WILL GIVE WAY TO HIGH PRESSURE RIGHT ON INTO TUESDAY. THIS WILL BE
FOLLOWED BY A FRONTAL BOUNDARY WEDNESDAY...THEN A COUPLE OF LOWS
THAT WILL BRING PRECIPITATION THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
AS OF 929 AM EST SUNDAY...MINOR UPDATE TO INCREASE CLOUDS ACRS THE
MTNS AND MENTION SOME FLURRIES. CRNT VIS SATL PIC SHOWS AREAS OF
CLOUDS/CLRING THIS MORNING...BUT KWMW 12Z SOUNDING SHOWS SOME
MOISTURE TRAPPED BLW DEVELOPING TEMP INVERSION. IN
ADDITION...LATEST RUC13 AND BTV4 RH PROFILES SHOW ENOUGH MOISTURE
BTWN SFC AND 850MB TO PRODUCE SOME CLOUDS TODAY...ESPECIALLY ACRS
THE MTNS. THEREFORE...WL MENTION PARTLY SUNNY SKIES AND WITH
UPSLOPE NW FLW A FEW FLURRIES WL BE POSSIBLE...ESPECIALLY THIS
AFTN WITH STEEPENING LLVL LAPSE RATES. OTHERWISE...TEMPS WL RANGE
FROM L20F MTNS/SLK/NEK TO M30 VSF.
PREVIOUS DISCUSSION...THRU THE EVENING/OVERNGT HRS...THE CWA
WILL SEE GENERAL CLRING TREND AS WK SHORTWAVE DISSIPATES DURING
THE DAY AND BE REPLACED BY STRONG SFC HIGH PRESSURE SYSTEM. WILL
BE KEEPING CLD COVER MCLDY/CLDY FOR CWA THRU MORNING HRS W/ CHANCE
FOR A FLURRY/LGT -SW...ESPECIALLY FOR HIR TRRN. NO ACCUM EXPECTED.
CD POOL AHEAD OF RIDGE WILL SINK OVER THE CWA BY TNGT. 850 TEMPS
NEAR -8C TO -10C. GUIDANCE APPEARS A BIT TOO CD FOR OVERNGT LOWS
SO WILL UP BY A FEW DEGREES...BUT STILL LOOKING FOR TEENS IN MOST
SPOTS.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH TUESDAY/...
AS OF 313 AM EST SUNDAY...NICE COUPLE OF DAYS ON TAP FOR THE NORTH
COUNTRY AS LARGE SFC RIDGE SHIFTS SLOWLY EAST FROM THE GREAT LKS
TO THE EAST COAST. CWA WILL BE ON CD SIDE OF RIDGE FOR MONDAY W/
LGT NNE FLOW. RIDGE CRESTS OVER THE REGION MONDAY NGT AND SHIFTS
OFF THE EAST COAST FOR TUESDAY. INCR WAA WILL ENSUE DURING THE DAY
TUESDAY AS SOUTHERLY FLOW KICKS IN. JET OUT AHEAD OF APPROACHING
SYSTEM FOR MIDWEEK WILL PROVIDE GUSTY CONDITIONS NEAR 20-30MPH.
MDL TIMING FOR NEXT SYSTEM APPROACHING FOR LATE TUESDAY OVER
WESTERN N NY. WILL BRING IN SL CHANCE FOR PRECIP LATE IN THE DAY
MAINLY OVER ST LAW VALLEY WHERE A FEW -RW/-SW COULD FALL. LITTLE
TO NO QPF FOR THIS TIME FRAME. TEMPS AT OR BLW NORMAL MON/MON NGT
AS RIDGE CREST OVER AREA...BUT SEVERAL DEGREES ABV NORMAL WITH
HIGHS NEAR 40F FOR TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 340 AM EST SUNDAY...FINALLY SOME INTERESTING WX TO DISCUSS AS
WE PROGRESS INTO THE MIDDLE AND LATTER PORTIONS OF NEXT WEEK.
MODELS CONTINUE IDEA OF A MEAN WEST COAST/EPAC RIDGE...AND A BROAD
CENTRAL CONUS TROUGH...WHICH PROGRESSES SLOWLY EAST THROUGH THE
PERIOD. BEING ON THE EASTERN/FRONT END OF THIS TROUGHING...THE
NORTHEAST WILL EXPERIENCE MILD THOUGH RATHER UNSETTLED WX AS A
SERIES OF MODEST LOW PRESSURE SYSTEMS RIDE ENE INTO THE REGION IN
THE BROAD SOUTHWESTERLY FLOW ALOFT. FIRST SYSTEM AND ASSOCIATED
OCCLUSION WILL SWING THROUGH THE REGION TUE NIGHT INTO EARLY
WEDNESDAY WITH SCT RAIN/SNOW SHOWER ACTIVITY. PTYPE TO BE GOVERNED
BY TIME OF DAY AND ELEVATIONAL DIFFERENCES...TYPICAL AS WE
PROGRESS INTO LATE WINTER WHEN NEAR SFC TEMPERATURE STRUCTURE
BECOMES MORE HEAVILY INFLUENCED BY INSOLATION. PERHAPS SOME MINOR
ACCUMULATIONS ACROSS THE HIGHER TERRAIN DURING THIS PERIOD...ESP
IN THE OVERNIGHT HOURS...BUT AS IS TYPICAL WITH FRONTAL OCCLUSIONS
AMOUNTS SHOULD BE LIGHT. LOWS TUESDAY NIGHT 27 TO 35...AND HIGHS
ON WEDNESDAY IN THE LOWER TO MID 40S PER MEAN 925 HPA TEMPS OF +1
TO +2C.
A BRIEF PERIOD OF CLOUDY THOUGH MAINLY DRY WX THEN EXPECTED BY
LATER WEDNESDAY INTO WEDNESDAY NIGHT BEFORE ADDITIONAL AND
SLIGHTLY STRONGER ENERGY PROGRESSES EAST INTO THE REGION BY
THURSDAY INTO FRIDAY. HAVE OFFERED A BLENDED ECWMF/GFS SOLN DURING
THIS PERIOD...WHICH APPEARS TO HAVE MERIT GIVEN UNCLIMATOLOGICAL
INLAND STRENGTHENING OF THE LOW PRESSURE CENTER OFFERED BY THE
GFS...AND THE PROSPECT OF SEVERAL DIFFICULT TO TIME ENERGY BUNDLES
SWINGING THROUGH THE REGION. THIS WOULD SUGGEST A RATHER SHARP
FRONTAL BOUNDARY SETTING UP OVER OR JUST NORTH OF OUR REGION WITH
A MEAN STORM TRACK THROUGH SLV AND AN INCREASING CHANCE OF
RAIN/SNOW SHOWER ACTIVITY. TEMPERATURE/QPF FORECAST QUITE TRICKY
WITH INCREASING EVIDENCE OF STRONG BAROCLINICITY AND INCREASING
FRONTOGENETICAL FORCING OVER OUR AREA. INDEED...COULD BE ONE OF
THOSE PERIODS WHERE THE FAR NORTH REMAINS STUCK IN THE 30S WHILE
SOUTHERN COUNTIES NEAR THE 50F MARK. THUS A BLENDED SOLN SEEMS THE
BEST ROUTE. AGAIN...GIVEN THE UNCERTAINTY IN THE LOW LEVEL THERMAL
STRUCTURE...PRIMARY PTYPE WILL BE RAIN SHOWERS IN THE
VALLEYS...AND A MIX OF RAIN/SNOW SHOWERS IN THE MTNS THU/FRI. AS
FRONT PUSHES SOUTH OF THE AREA LATER FRIDAY...PCPN WILL TRANSTION
TO SHSN IN ALL AREAS AS COLDER AIR FILTERS INTO THE REGION. THEN
GENERALLY DRY AND SEASONABLY COLD BY NEXT SATURDAY AS HIGH
PRESSURE BUILDS INTO THE REGION.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
THROUGH 12Z MONDAY...SCT/BKN VFR CIGS FROM FL035-050 EXPECTED
THROUGH THE PERIOD UNDER NORTH TO NORTHWESTERLY WINDS 3-7 KTS.
ONLY EXCEPTIONS AT KSLK/KMPV WHERE OCCNL MVFR CIGS FROM FL018-028
POSSBL THROUGH 16Z. NO PCPN EXPECTED.
OUTLOOK 12Z MONDAY THROUGH THURSDAY...
12Z MONDAY THROUGH 00Z WEDNESDAY...VFR UNDER HIGH PRESSURE.
00Z WEDNESDAY THROUGH 00Z THURSDAY...MAINLY VFR WITH OCCNL
MVFR/IFR RAIN/SNOW SHOWERS POSSIBLE AS WEAK LOW PRESSURE PASSES
NORTH OF THE REGION WITH OCCLUDED FRONTAL PASSAGE.
00Z THURSDAY THROUGH 00Z FRIDAY...NEXT SHORTWAVE TROUGH AND
ASSOCIATED SFC LOW BRINGS A CHANCE OF RAIN OR SNOW SHOWERS...
THOUGH TIMING AND SPATIAL DETAILS ARE NOT WELL RESOLVED ATTM.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JN
NEAR TERM...JN/TABER
SHORT TERM...JN
LONG TERM...JMG
AVIATION...JMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1253 AM EST SUN FEB 19 2012
.SYNOPSIS...
A FEW LINGERING FLURRIES WILL SHIFT FROM THE SYRACUSE AREA
OVERNIGHT...TO THE FINGER LAKES REGION SUNDAY MORNING...BEFORE HIGH
PRESSURE BRINGS QUIET WEATHER THROUGH TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
10 PM...LAST PCPN FROM THE SHRT WV IS NOW WELL EAST AND SOUTH OF
THE FCST AREA. BOTH THE WRFARW AND THE HRRR SHOW SOME WEAK LE FOR
THE NEXT FEW HRS OVER THE NRN FINGER LAKES IN THE NLY FLOW OFF
ONTARIO. 88D COMPOSITE DOES SHOW SOME WEAK ECHOES IN THE AREA SO
WILL CONT WITH CHANCE POPS IN THAT AREA FOR THE NEXT FEW HRS.
7PM...SHRT WV IS NOW SLIDING EAST OF THE AREA AND WHAT LOOKS LIKE
THE LAST ROUND OF SNOW SHWRS IS MVG THRU THE MIDDLE OF THE FCST
AREA. BHD THE WV...JUST SOME LIMITED LE SNOW SHWRS XPCTD WITH LTL
ACCUM. TOO MUCH SHEAR AND SIMPLY NOT ALL THAT COLD SO NOT MUCH LE
XPCTD. PRVS DISC BLO.
A WEAK LOW PRESSURE SYSTEM IS CURRENTLY MAKING ITS WAY INTO THE
CWA THIS AFTERNOON. IT WILL MAKE IT ACROSS AND WEAK OVERNIGHT
TONIGHT. THERE WILL BE SOME SHOWERS WITH THIS SYSTEM, MAINLY IN
THE FORM OF SNOW, BUT SOME AREAS, ESPECIALLY IN NEPA, MAY SEE SOME
RAIN. CURRENTLY, RADAR RETURNS OVER NEPA ARE NOT REFLECTING WHAT
IS BEING REPORTED BY ASOS AT A COUPLE OF SITES. BOTH MSV AND AVP
HAD STRONGER RETURNS PASS DIRECTLY OVERHEAD AND NEITHER REPORTED
ANY PRECIPITATION. ON THE OTHER HAND, RME HAD SOME LIGHTER RETURNS
AND IS REPORTING MODERATE SNOW. SAME WITH ELZ. THIS MAKES
FORECASTING POPS A LITTLE TRICKY. BEST GUESS IS SOME VIRGA, WITH
FLURRIES/SPRINKLES AND ISOLATED SHOWERS. THIS WILL CONTINUE
THROUGH THE AFTERNOON. THE HRRR DID SHOW THIS TYPE OF RETURNS, SO
WILL MODEL POPS AFTER THAT, AT LEAST AS GUIDANCE FOR TIMING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
THIS LOW, AS MENTIONED BEFORE, WILL MOVE ACROSS TONIGHT AND WILL
WEAKEN AS IT DOES. SOME COLD AIR ADVECTION WILL FOLLOW BEHIND IT
AND MAY KICK OFF SOME LAKE EFFECT SNOW IN THE NORTHERN AND FINGER
LAKE ZONES. NOT EXPECTING MORE THEN A COUPLE OF INCHES FROM ANY OF
THESE SNOW SHOWERS. BY SUNDAY MORNING, HIGH PRESSURE WILL BEGIN TO
BUILD IN AND LAKE EFFECT WILL COME TO AN END SUNDAY MORNING. THIS
HIGH PRESSURE WILL KEEP A STRONG LOW PRESSURE SYSTEM WELL TO THE
SOUTH OF THE FORECAST AREA.
SUNDAY WILL BE THE COOLER DAY, WITH NEAR NORMAL TEMPS IN THE
AFTERNOON. THEN, WARM AIR ADVECTION WILL SLOWLY INCREASE
TEMPERATURES THROUGH THE MIDDLE OF THE WEEK, WITH UPPER 40S
POSSIBLE ON TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MAIN PLAYER FOR THE PERIOD WILL BE A DEVELOPING MID-LEVEL VORTEX
SOUTH OF HUDSON BAY WHICH WILL KEEP MUCH OF THE GREAT LAKES REGION
EMBEDDED IN SW FLOW ALOFT. AS IS THE CASE WITH THESE SYNOPTIC
SITUATIONS...EMBEDDED SHORTWAVE DISTURBANCES ROTATING ALONG THE
SOUTHERN PERIPHERY OF THIS FEATURE WILL RESULT IN AN ACTIVE WX
PATTERN FOR MUCH OF THE GREAT LAKES REGION TOWARDS MID/LATE WEEK.
GFS AND ECMWF DETERMINISTIC PROGS APPEAR TO BE IN FAIRLY GOOD
AGREEMENT TO START OUT THE PERIOD WITH FIRST SHORTWAVE/SFC FRONT
EXPECTED TO MOVE THROUGH THE REGION ON WED. WITH ITS
ARRIVAL...EXPECT MAINLY A RA/SN MIX WED NGT BEFORE TRANSITIONING TO
ALL RA BY LATE WED MORNING/EARLY AFTERNOON. MODELS THEN ADVERTISE
A MORE POTENT DISTURBANCE ON THRU AS SECOND SHORTWAVE ROTATES INTO
THE REGION. AGAIN...EXPECT RA/SN MIX LATE WED/EARLY THU BEFORE
ONCE AGAIN CHANGING OVER TO ALL RA THROUGH THE DAY. MODEL
DIFFERENCES DO APPEAR BY THIS POINT HOWEVER AS GFS PHASES BOTH
NORTHERN AND SOUTHERN STREAM ENERGY CORES ACROSS THE TENN RVR
VLY/SOUTHERN APPALACHIANS BEFORE DEVELOPING A COASTAL LOW BY LATE
THU OFF THE HATTERAS COAST. ECMWF ON THE OTHER HAND SHOWS NO
INDICATION OF PHASING AND NO SUGGESTION FOR ANY COASTAL
DEVELOPMENT. IF THE GFS/S SCENARIO WERE TO PAN OUT...FEATURE LOOKS
TO BE A QUICK HITTER WITH MAIN QPF SHIELD REMAINING SOUTH AND
EAST OF THE CWA. FUTURE MODEL RUNS MOST CERTAINLY BARE WATCHING.
NEXT COLD FRONT EXPECTED TO MOVE THROUGH THE REGION ON FRI WHICH
WILL BE FOLLOWED BY THE ARRIVAL OF ARCTIC HIGH PRESSURE AND A
CHILLY START FOR NEXT WEEKEND. MODELS SUGGEST H85 TEMPS FALLING TO
NEAR -18C WHICH WILL LIKELY RESULT IN A LAKE RESPONSE OFF OF LAKE
ONTARIO IN NORTHWEST FLOW ALOFT.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
WEAK NORTHERLY TO NORTH-NORTHWESTERLY FLOW OVER LAKE
ONTARIO...WILL LEAD TO THE TYPICAL STRATOCUMULUS DECK DETAIL
CONUNDRUMS DURING THE TAF PERIOD...MAINLY FOR CENTRAL NEW YORK
TERMINALS. IN GENERAL...LOOKING AT MOST SITES BOUNCING IN AND OUT
OF MVFR THROUGH 14Z...AND EVEN SOME LAKE EFFECT FLURRIES SHIFTING
FROM KSYR AREA...WESTWARD TO KELM AND PERHAPS KITH. IMPROVEMENT TO
AREAWIDE VFR OCCURS BETWEEN 14Z-18Z...WITH VFR ESPECIALLY 18Z- 02Z
WHEN ENTRAINMENT OF DRY AIR FROM MID LEVELS WILL BE AT ITS PEAK
DURING MIXING HOURS...FOLLOWED BY LOSS OF DIURNAL HEATING AND
RESULTING DISSIPATION OF CELLULAR CLOUDS. 02Z- 06Z
MONDAY...EXPECTING REDEVELOPMENT OF MVFR STRATOCUMULUS FOR MOST
SITES AS MOISTURE GETS TRAPPED AGAIN UNDER INVERSION...COURTESY OF
CONTINUED FLOW OFF OF LAKE ONTARIO.
.OUTLOOK...
LATE SUN NGT/MON MRNG...PERSISTENT MVFR DECK FOR A GOOD CHUNK OF
THE AREA FROM MOISTURE TRAPPED UNDER INVERSION...BREAKING UP LATE
MON MORNING.
MON AFTN/TUE MRNG...MAINLY VFR.
TUE AFTN/WED/THU...MVFR AND POSSIBLE IFR IN MIXED PRECIPITATION AS
AT LEAST A COUPLE SYSTEMS PASS THROUGH THE REGION.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...SLI/MDP
NEAR TERM...DGM/SLI
SHORT TERM...SLI
LONG TERM...CMG
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1240 PM EST SUN FEB 19 2012
.SYNOPSIS...
LOW PRESSURE WILL APPROACH FROM THE SOUTHWEST AND MOVE NORTHEAST
ALONG THE COAST LATE TODAY AND TONIGHT. HIGH PRESSURE WILL BUILD IN
FROM THE WEST LATE MONDAY INTO TUESDAY. A COLD FRONT WILL APPROACH
FROM THE WEST WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 1235 PM SUNDAY...RAIN FILLING BACK IN OVER THE REGION WITH
SOME HEAVIER SHOWERS INDICATED JUST SOUTH OF THE SOUTHERN COASTAL
COUNTIES AND EVEN SOME THUNDER OFFSHORE. THIS IS IN RESPONSE TO
MID-LEVEL JET MAX MOVING NORTHEAST FROM SOUTH CAROLINA. DESPITE
SOME BREAKS IN THE RAINFALL...KEPT POPS IN THE CATEGORICAL RANGE
FOR THE AFTERNOON. TEMPERATURES ARE LOCKED IN THE 40S TO LOWER 50S
AND EXPECT LITTLE CHANGE THRU THE AFTERNOON GIVEN CLOUDS AND
PRECIPITATION.
&&
.SHORT TERM /MONDAY NIGHT/...
AS OF 700 AM SUNDAY...LOW PRESSURE EXITS THE COAST WITH VERY WIND
CONDITIONS THIS EVENING FOR PORTIONS OF THE ALBEMARLE
COUNTIES...COUNTIES ADJACENT TO THE PAMLICO SOUND...AND THE OBX
WHERE WIND ADVISORIES HAVE BEEN POSTED FOR LATE THIS EVENING
THROUGH MON. A STRONG MID-LEVEL SHORTWAVE TROF DIVES SOUTH WITH
COLDER AIR SURGING SOUTH AND WRAP AROUND MOISTURE LEADING TO RAIN
CHANGING TO SNOW AFTER MIDNIGHT AND CONTINUING INTO MONDAY
MORNING...MAINLY OVER THE NORTHEASTERN COUNTIES/NORTHERN OUTER
BANKS REGION. THICKNESS VALUES SUPPORT A RAIN/SNOW MIX INITIALLY
WITH A CHANGE TO ALL SNOW AFTER ABOUT 08Z OR SO. ANY SNOWFALL
AMOUNTS AND HAVE CONTINUED WITH JUST 0.1 TO 0.4 INCH OVER THE
NORTHERN OUTER BANKS AND AREAS ADJACENT TO THE ALBEMARLE SOUND
THUS WILL NOT ISSUE A WINTER WEATHER ADVISORY ON THIS SHIFT. WITH
WARM GROUND TEMPS DON`T EXPECT SIG ACCUMULATIONS AT THIS TIME.
HOWEVER...THIS WILL CONT TO BE MONITORED BY FUTURE SHIFTS. TEMPS
LOWER INTO THE MID 30S INLAND AND LOWER TO MID 40S IMMEDIATE COAST
TONIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 AM SUN...ONLY MINOR CHANGES TO PREVIOUS FCST DURING PERIOD.
DEEPENING LOW PRES WILL BE ABOUT 300 MILES ENE OF HAT AT BEGINNING OF
PERIOD WITH MODERATE ARCTIC HIGH PRES BUILDING IN BEHIND IT WITH
STRONG WINDS CONTINUING OVER COASTAL SECTIONS. LINGERING THREAT OF
SNOW SHOWERS WITH SECONDARY SHRT WV TROF WILL END BY MID MORNING.
CLEARING SKIES AND DIMINISHING WINDS REST OF DAY WITH HIGH PRES
CENTER BUILDING IN. BELOW NORMAL TEMPS EXPECTED MON NIGHT WITH HIGH
CENTER OVERHEAD...THEN A QUICK WARM-UP TUE WITH HIGH QUICKLY MOVING
OFFSHORE AS NEXT SHRT WV TROF APPROACHES. 00Z MODELS HAVE TRENDED TO
SOME LIGHT QPF ALONG COASTAL SECTIONS TUE AFTN WITH RETURN SRLY FLOW
BUT APPEAR OVERDONE WITH EXPECTED STABLE CONDITIONS OVER COLDER NEAR
SHORT WATERS...THUS NOT ENOUGH CONFIDENCE TO ADD POPS AT THIS TIME.
MAINLY ZONAL FLOW ALOFT AND SEVERAL SHRT WVS AND ASSCTD FRONTS WILL
AFFECT AREA WED-THU WITH LATEST MODELS INDICATING PCPN THREAT
REMAINING MAINLY N AND S OF AREA BUT LEFT PREVIOUS FCST LOW CHC
POPS. DEEPER SHRT WV TROF AND SFC FRONT WILL MOVE THROUGH LATE FRI
FOLLOWED BY COOLER AIR MASS FOR NEXT WEEKEND.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM /06Z SUNDAY THROUGH 06Z MONDAY/...
AS OF 1240 PM SUNDAY...IFR CONDITIONS ARE LIKELY THRU THE
OVERNIGHT HOURS AS PRECIPITATION CONTINUES TO OVERSPREAD THE
REGION. ADDED A MIX OF RAIN AND SNOW AT PGV AS COLDER AIR FILTERS
IN WITH A MIX LIKELY AFTER MIDNIGHT TONIGHT.
LONG TERM /06Z MONDAY THROUGH THURSDAY/...
AS OF 3 AM SUN...CIGS AND VSBYS WILL GRADUALLY IMPROVE TO VFR
09Z-12Z MON...WITH CLEARING EXPECTED 12Z-15Z. GUSTY NORTHERLY WINDS
WILL CONTINUE THROUGH MORNING...THEN DIMINISH DURING AFTN. VFR
CONDITIONS WILL PREVAIL REST OF PERIOD WITH ONLY MINIMAL THREAT OF
PCPN WITH SERIES OF WEAK SHRT WVS AND SFC FRONTS.
&&
.MARINE...
SHORT TERM /TODAY AND TONIGHT/
AS OF 1240 PM SUNDAY...WINDS STARTING TO RAMP UP OVER THE PAST FEW
HOURS WITH GUSTS TO 30 KNOTS NOW OBSERVED AT DUCK WITH SEAS
BUILDING TO 7 FEET. RUC13 HAS THE BEST DEPICTION AND HAVE FOLLOWED
THAT FOR THE NEAR TERM. WHILE THERE MAY BE A BRIEF LULL IN THE
WIND AS THE SURFACE LOW APPROACHES...WILL NOT INDICATE IN TEXT AS
WINDS SHOULD INCREASE TO GALE FORCE TONIGHT. NORTH WINDS TO INCREASE
TO 25 TO 35 KNOTS WITH 30 TO 40 KNOTS ALONG THE NORTHERN WATERS
TONIGHT INTO MONDAY. THE PEAK WINDS WILL OCCUR FROM 06Z TO ABOUT
14Z MONDAY. THE GUSTY NLY WINDS WILL LEAD TO ELEVATED WATER LEVELS
FROM JUST N OF THE HATTERAS AREA TO CEDAR ISLAND AND OVER SOUTHERN
PAMLICO SOUND. A COASTAL FLOOD ADVISORY REMAINS IN EFFECT FOR
WATER LEVELS OF 1 TO 2 FEET ABOVE NORMAL WITH SOME LOCALIZED AREAS
AT 3 FEET ABOVE NORMAL FOR TONIGHT AND MONDAY. SEAS PEAK AT 7 TO
12 FEET...MAINLY OVER NORTHERN AND CENTRAL COASTAL WATERS TONIGHT
AND MONDAY.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM SUN...NO SIGNIFICANT CHANGES TO PREVIOUS FCST DURING
PERIOD. ONGOING GALE EVENT ALL WATERS WILL GRADUALLY WEAKEN MONDAY
AS HIGH PRES BUILDS IN FROM W AND LOW PRES MOVES FARTHER OFFSHORE.
WINDS WILL CONTINUE DECREASING MON NIGHT WITH HIGH CENTER BUILDING
OVER AREA...THEN QUICKLY BECOME SE-S TUE AS HIGH MOVES OFFSHORE.
SERIES OF WEAK FRONTS WILL AFFECT AREA WED-THU WITH MODERATE SW
WINDS. STRONGER FRONT WILL APPROACH LATE THU WITH SCA CONDITIONS
PSBL AGAIN.
WW3 AND SWAN IN GENERAL AGREEMENT ON SEAS AND ALSO WITH PREVIOUS
FCST. HEIGHTS UP TO 12 FEET EXPECTED NRN AND CENTRAL WATERS EARLY
MON...THEN GRADUALLY SUBSIDING INTO TUE BUT RESIDUAL SWELL WILL
LIKELY KEEP AROUND 6 FT OVER OUTER PORTIONS OF NRN AND CENTRAL
WATERS INTO TUE NIGHT. SEAS BUILDING AGAIN LATE THU WITH INCREASING
SW WINDS AHEAD OF NEXT STRONG FRONT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...WIND ADVISORY FROM 10 PM THIS EVENING TO 4 PM EST MONDAY FOR
NCZ103-104.
COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST
MONDAY FOR NCZ093-095-103-104.
WIND ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST MONDAY FOR
NCZ046-047-081-095.
HIGH SURF ADVISORY FROM 10 PM THIS EVENING TO 10 PM EST MONDAY
FOR NCZ103.
MARINE...GALE WARNING FROM 10 PM THIS EVENING TO 5 PM EST MONDAY FOR
AMZ130-135-150-152-154-156-158.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...CQD
AVIATION...CTC/CQD
MARINE...CTC/JAC
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
550 AM CST SUN FEB 19 2012
.DISCUSSION.../ISSUED AT 415 AM CST/
MAIN FORECAST CONCERN WILL FOCUS ON A TROUGH CURRENTLY DIGGING INTO
THE INTERMOUNTAIN WEST THIS MORNING. THE BIG FORECAST CHALLENGE WITH
THIS SYSTEM WILL BE PRECIPITATION TYPE WITH VERY LITTLE COLD AIR
ASSOCIATED WITH THE SYSTEM AND LOW LEVEL TEMPERATURES LIKELY TO
HOVER RIGHT AROUND FREEZING.
AHEAD OF THIS TROUGH.... BREEZY SOUTHERLY WINDS WILL BRING IN A GOOD
SHOT OF WARM AIR ADVECTION TODAY AS 925 MB TEMPERATURES RISE ABOVE
ZERO ACROSS THE CWA. THIS ADVECTION WILL BE GREATEST IN THE JAMES
RIVER VALLEY INTO SOUTH CENTRAL SOUTH DAKOTA WHICH SHOULD EASILY MIX
DOWN INTO THE LOWER 50S THIS AFTERNOON...WITH THE REST OF THE CWA IN
THE 40S.
CLOUDS WILL BE ON THE INCREASE THIS AFTERNOON AND OVERNIGHT AS THE
UPPER LEVEL TROUGH DIGS INTO THE FOUR CORNERS REGION WHILE THE MID
LEVEL TROUGH BEGINS EMERGING INTO THE CENTRAL HIGH PLAINS. WITH
MOISTURE INCREASING RAPIDLY OVERNIGHT AND BREEZY WINDS PERSISTING
PAST SUNSET...TEMPERATURES WILL LIKELY FALL OFF SOME IN THE LATE
EVENING...AND THEN REMAIN FAIRLY STEADY OR SLIGHTLY RISE AFTER
MENDICANT. TEMPERATURES PROFILES SUGGEST THAT TEMPERATURES COULD RISE
TO NEAR OR JUST ABOVE FREEZING ACROSS THE BULK OF THE CWA BY 12Z
MONDAY. PRECIPITATION WILL START INTENSIFYING ACROSS OUR WESTERN
HALF LATE SUNDAY NIGHT AND EARLY MONDAY...WITH PRECIPITATION
STARTING OUT AS SNOW OR A RAIN AND SNOW MIX. COULD SEE SOME SLEET
TOWARDS THE ONSET OF THE PRECIPITATION...BUT THINK THAT FZRA OR FZDZ
THREAT IS MINIMAL WITH SURFACE TEMPERATURES POTENTIALLY TOO WARM
EVEN AT ONSET OF PRECIPITATION.
PRECIPITATION WILL GRADUALLY SHIFT EASTWARD THROUGH THE DAY AND HAVE
EXPANDED THE CATEGORICAL POPS ACROSS THE FORECAST AREA ON MONDAY.
WITH VERY LITTLE COLD AIR ADVECTING INTO THE PLAINS WITH THE ARRIVAL
OF THE TROUGH...EXPECT TEMPERATURES TO PEAK IN THE MID 30S TO NEAR
40 UNDER THE ROBUST SOUTHERLY FLOW. BY LATE MORNING...THE MISSOURI
RIVER VALLEY WILL LIKELY SWITCH OVER TO RAINFALL...WHICH COULD
EXTEND AS FAR NORTHWARD AS THE US 14 CORRIDOR BY THE AFTERNOON.
WINDS SWITCH AROUND TO THE NORTH BEGINNING MONDAY AFTERNOON ALONG
OUR WESTERN BORDER...ALLOWING RAIN TO TRANSITION BACK TO SNOW FROM
WEST TO EAST OVERNIGHT. THIS TRANSITION WILL BE FAIRLY BRIEF WITH
THE SYSTEM EXITING TO OUR EAST AND THE PRECIPITATION TAPERING OFF
OVERNIGHT.
SNOWFALL AMOUNTS REMAIN TRICKY TO PINPOINT FOR THIS EVENT AND WILL
BE LARGELY DEPENDENT UPON SURFACE TEMPERATURES AND PRECIPITATION
INTENSITY. GFS...ECMWF AND GEM PAINT DECENT INSTABILITY AND STRONG
MID LEVEL LIFT WHICH SHIFTS NORTHWARD THROUGH THE JAMES RIVER VALLEY
INTO THE MADISON AND BROOKINGS AREA BY MONDAY AFTERNOON. WHILE
TEMPERATURE PROFILES SUGGEST MAINLY RAINFALL OR AT BEST A MIX...THE
MORE INTENSE SNOWFALL BANDS COULD OVERCOME THE RELATIVELY WARM
SURFACE TEMPERATURES AND BRING MORE SIGNIFICANT SNOWFALL
ACCUMULATIONS. AT THIS POINT...WILL KEEP AMOUNTS CONSERVATIVE AND
CONTINUE TO MONITOR THE SITUATION. WITH OUR NORTHERN BORDER INTO
SOUTHWEST MINNESOTA LIKELY TO HOLD ONTO SNOWFALL THE LONGEST...HAVE
PLACED THE HIGHEST ACCUMULATIONS THERE. ELEVATION COULD ALSO PLAY AN
INTERESTING ROLE...BRINGING LOCALLY HIGHER AMOUNTS TO THE BUFFALO
RIDGE AREA IN PARTICULAR. DESPITE QPF AMOUNTS OF A QUARTER TO HALF
INCH...POOR SNOW GROWTH...MILD TEMPERATURES AND POSSIBLE RAIN WILL
KEEP SNOW RATIOS ON THE LOW END OF THE SPECTRUM. GENERALLY WENT WITH
AROUND AN 8:1 RATIO ON MONDAY AND SLIGHT HIGHER BOOKEND AMOUNTS. THE
END RESULT IS STORM TOTAL SNOWFALL 2 TO 4 INCHES NORTH OF A KHON TO
KFSD TO KSPW LINE. GIVEN THE LONG DURATION OF THIS EVENT AND THE
POTENTIAL MELTING OF SNOW WITH RAIN...WILL NOT ISSUE ANY HEADLINES
WITH THIS PACKAGE.
CLOUDS WILL BE ON THE DECREASE ON TUESDAY WITH NORTHWEST FLOW
ARRIVING IN THE WAKE OF THE EXITING SYSTEM. TEMPERATURES ARE
EXPECTED TO REMAIN MILD WITH HIGHS BACK INTO THE UPPER 30S AND LOWER
40S. /
FOR THE EXTENDED RANGE /WEDNESDAY THROUGH SATURDAY/ THE GENERAL
LARGE SCALE IDEA OF CARVING OUT A CYCLONIC FLOW BY MID TO LATE WEEK
AS POLAR VORTEX SETTLES ACROSS HUDSON BAY IS WELL RECEIVED IN A VAST
MAJORITY OF SOLUTIONS. IT IS THE DAY TO DAY LOCATION AND TRACK OF
THE QUICK MOVING WAVES IN THE CYCLONIC NORTHWEST FLOW THAT IS A HUGE
INCONSISTENCY. DID NOT SEE REASON TO ALTER SIGNIFICANTLY THE 20 TO
30 POPS FOR WEDNESDAY THROUGH THURSDAY PERIOD WITH VARIETY OF ILL
TRACKED AND TIMED WAVES. MOST CONSISTENT FEATURE WOULD PROBABLY BE
THE LATER TUESDAY NIGHT INTO WEDNESDAY WAVE...BUT TEMPERATURES ARE
SUCH THAT WOULD BE CONCERNED FOR SOME RAIN/SNOW MIX. COOLER AIR WILL
FILTER SOUTHWARD...WITH BULK OF COOLING WORKING IN BEHIND WAVE FOR
LATER WEDNESDAY NIGHT AND THURSDAY...WHATEVER TRACK IT ENDS UP
TAKING. NUMEROUS SOLUTIONS OF GFS ENSEMBLE ARE STRONGER WITH LOBE
WRAPPING SOUTHWARD THROUGH MINNESOTA ON THURSDAY. DIURNAL RANGE
SHOULD BE SOMEWHAT RESTRAINED INTO THURSDAY BEFORE DRYING OUT THE
PRECIP THREAT AND BUILDING LOW LEVEL RIDGE IN OVER THE AREA BY
FRIDAY NIGHT. /CHAPMAN
&&
.AVIATION.../FOR THE 12Z TAF ISSUANCE/
VFR CONDITIONS SHOULD PREVAIL ACROSS THE CWA THROUGH 06Z MONDAY.
HOWEVER...WILL HAVE TO KEEP TABS ON THE STRATUS FROM WESTERN KANSAS
INTO SOUTHWEST NEBRASKA...AS LATEST RUC SUGGESTS THAT THIS AREA
COULD MOVE INTO SOUTH CENTRAL SOUTH DAKOTA AFTER 18Z...AND IF IT
DOES NOT MIX OUT AS INDICATED...COULD IMPACT AREAS WEST OF THE JAMES
VALLEY AS EARLY AS 21Z-00Z...BUT MORE LIKELY TO DISSIPATE AND
REDEVELOP AFTER 06Z. FOCUS OF WARM AIR ADVECTION WITH SOMEWHAT
UNSTABLE PROFILE SHOULD ALLOW PRECIP TO DEVELOP FAIRLY RAPIDLY IN
THE 06Z-09Z TIMEFRAME FROM NEBRASKA INTO CENTRAL SD...AND THEN
ADVECT RAPIDLY NORTH/NORTHEAST. THERMAL PROFILES SUGGEST THAT TYPE
IS STILL SOMEWHAT IN QUESTION...BUT SHOULD EITHER BE RAIN OR SNOW...
AS IF TEMPERATURES WARM...THEY SHOULD WARM ENOUGH THROUGHOUT THE
ENTIRE LAYER WITH 40-50 KNOT SOUTHERLY LOW LEVEL JET. IN THE
MEANTIME...GUSTY SOUTHERLY WINDS OF 20 TO 25 KNOTS LIKELY TODAY.
/CHAPMAN
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
943 PM CST MON FEB 20 2012
.DISCUSSION...MINOR CHANGES WERE MADE TO THE ONGOING FORECAST.
ALTERED CLOUD COVER TO REFLECT SLOWER DEVELOPMENT OF STRATUS AND
FOG FOR TONIGHT AND INCREASED DEWPOINTS SLIGHTLY. MSAS AND
SURFACE ANALYSES THIS EVENING HAVE A COLD FRONT DRAPED ACROSS
CENTRAL TX WITH THIS FRONT PROG TO DRIFT INTO AT LEAST NORTHERN
PORTIONS OF S TX BY LATE TONIGHT. AHEAD OF THE FRONT A GRADUAL
INFLUX OF LOW LEVEL MOISTURE WILL CONTINUE AND WITH LIGHT SURFACE
WINDS AND THE INCREASING MOISTURE AREAS OF FOG MAY DEVELOP.
STATISTICAL GUIDANCE CONTINUES TO INDICATE NEARLY WIDESPREAD FOG
TONIGHT WHILE RAW MODEL OUTPUT IS LESS PESSIMISTIC. NAM WANTS TO
DEVELOP FOG ACROSS MANY INLAND LOCATIONS SHORTLY AFTER MIDNIGHT
BUT DISSIPATES MUCH OF IT SHORTLY BEFORE SUNRISE. LATEST RUC HAS
AREAS OF FOG DEVELOPING AND DISSIPATING ON AND OFF THROUGH THE
NIGHT. DENSE CIRRUS PERSISTS ACROSS S TX TONIGHT AS UPPER JET
REMAINS OVERHEAD AND UNCERTAINTY REMAINS AS TO HOW MUCH OF AN
INFLUENCE THAT WILL HAVE ON FOG DEVELOPMENT AS WELL. FOR NOW WILL
MAINTAIN AREAS OF FOG IN THE FORECAST. UPDATED PRODUCTS TO BE
SENT SOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 57 74 61 76 64 / 10 10 20 20 30
VICTORIA 55 73 57 76 60 / 10 10 10 10 30
LAREDO 58 74 64 82 65 / 10 10 10 10 30
ALICE 56 75 60 79 63 / 10 10 20 10 30
ROCKPORT 58 73 60 67 64 / 10 10 20 20 30
COTULLA 51 73 58 80 63 / 10 10 10 10 30
KINGSVILLE 55 74 60 77 64 / 10 10 20 20 30
NAVY CORPUS 60 72 61 69 64 / 10 10 20 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
UPDATE...HART/79
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
856 PM CST MON FEB 20 2012
.DISCUSSION...GUIDANCE IS BULLISH ON LOW CEILINGS AND PATCHY TO
AREAS OF FOG TONIGHT THROUGH MID TUESDAY MORNING. SCT TO BKN HIGH
CLOUDS NOT PLAYING A MAJOR ROLE. RUC IS SHOWING AMPLE LOW LEVEL
MOISTURE...COUPLED WITH CONTINUING LIGHT ONSHORE WINDS. WIDESPREAD
DENSE FOG IS NOT EXPECTED...BUT LOCAL AREAS OF DENSE FOG WILL BE
POSSIBLE...ESPECIALLY IN THE MID AND UPPER VALLEY. SAT IMAGERY
ALSO SUGGESTS LOW CLOUDS IN THE WEST GULF MOVING NORTHWEST TOWARD
THE REGION. BEEFED UP THE WORDING IN THE FORECAST AND REISSUED TO
REFLECT THE DEVELOPING SITUATION.
&&
.PREV DISCUSSION... /ISSUED 523 PM CST MON FEB 20 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...FOG AND LOWER CEILINGS LOOK PRETTY CERTAIN TONIGHT
WITH WINDS BECOMING LIGHT AND INCREASING LOW LEVEL MOISTURE. SCT
TO BKN HIGH CLOUDS WILL NOT BE ENOUGH TO PREVENT TEMPERATURES FROM
DECREASING TO THE CORRESPONDING DEW POINTS TONIGHT. LOCALLY DENSE
FOG LOOKS LIKELY IN THE MID AND UPPER VALLEY...BUT IFR CONDITIONS
ARE DEFINITELY ON TAP FOR THE LOWER VALLEY...DEVELOPING AFTER
MIDNIGHT WITH WORSENING CONDITIONS THROUGH DAWN TO MID TUESDAY
MORNING. NOT READY TO POUNCE ON A DENSE FOG ADVISORY JUST YET...
BUT WILL PROBABLY BEEF UP THE FOG CHARACTERIZATION SOMEWHAT IN A
LOCAL FORECAST UPDATE. THE TAFS TAKE FOG INTO ACCOUNT NOW.
PREV DISCUSSION... /ISSUED 120 PM CST MON FEB 20 2012/
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...NORTHEAST FLOW ALOFT
WILL CONTINUE TO STREAM CIRRUS CLOUDS ACROSS THE RIO GRANDE VALLEY
AS MID LEVEL MOISTURE OVER THE PACIFIC IS BEING PUSH INTO THE
AREA. SURFACE SOUTHEAST FLOW WITH GUSTY WINDS WILL PREVAIL THROUGH
THE AFTERNOON. EXPECT WINDS TO BEGIN TO DECOUPLE AFTER SUNSET.
GOOD MOISTURE IN THE AREA AND LIGHT SOUTHEAST WINDS WILL PROVIDE
GOOD CONDITIONS FOR PATCHY FOG TO DEVELOP AFTER MIDNIGHT.
LOCATIONS FURTHER NORTH AND WEST WILL LIKELY SEE MORE DENSE FOG
THAN THE LOWER VALLEY TONIGHT. LOW TEMPERATURES WILL REMAIN IN THE
MID 60S ALONG THE COAST AND LOCATIONS CLOSE TO THE BORDER WITH THE
COOLER SPOTS IN THE NORTHERN COUNTIES. NO MUCH PRECIPITATION
EXPECTED UNTIL TUESDAY NIGHT INTO WEDNESDAY MORNING AS A WEAK
DISTURBANCE WITHIN THE UPPER LEVEL FLOW MOVES ACROSS THE AREA.
HIGH TEMPERATURES WILL WARM BACK REACHING CLOSE TO THE 80S.
ANOTHER ROUND OF WIDESPREAD FOG WILL LIKELY DEVELOP WEDNESDAY
AFTER MIDNIGHT. LIGHTER WINDS AND MORE MOISTURE IN THE AREA WILL
ENHANCE THE DEVELOPMENT OF FOG TO BE MORE WIDESPREAD ACROSS THE
FORECAST AREA.
LONG TERM /WEDNESDAY THROUGH SUNDAY/...NO SIGNIFICANT CHANGES WERE
MADE TO THE FORECAST IN THE LONG TERM. SCATTERED SHOWERS ARE EXPECTED
WEDNESDAY AND WEDNESDAY NIGHT DUE TO THE SLOW PROGRESSION OF A 500 MB
CLOSED LOW OVER THE NORTHWEST CORNER OF MEXICO. AS THE LOW FILLS AND
DRAGS A SHARP MID-LEVEL TROUGH THROUGH THE LONE STAR STATE...A WEAK
PACIFIC COLD FRONT WILL PASS THROUGH DEEP SOUTH TEXAS AND THE RIO
GRANDE VALLEY THURSDAY...WITH SCATTERED SHOWERS AND THUNDERSTORMS.
A MORE SIGNIFICANT COLD FRONT WILL PASS THROUGH OUR REGION THURSDAY
NIGHT...HOWEVER DRIER AIR ASSOCIATED WITH THE WAKE OF THE PACIFIC
COLD FRONT WILL PREVENT ANY PRECIPITATION FOR THAT TIME. PLEASANT
CONDITIONS ARE FORECAST FRIDAY THROUGH SUNDAY WITH DRY WEATHER DUE
TO A NEARLY ZONAL FLOW IN THE MIDDLE LAYERS OF THE ATMOSPHERE OVER
THE BRO CWFA FOR THAT PERIOD. NEAR TO ABOVE NORMAL TEMPERATURES
WEDNESDAY AND THURSDAY WILL BE COOLED TO NEAR NORMAL LEVELS FRIDAY
AND SATURDAY COURTESY OF THE COLD FRONTAL PASSAGE THURSDAY NIGHT...
WITH WARMING TEMPERATURES ANTICIPATED FOR SUNDAY DUE TO AN ONSHORE
FLOW.
MARINE...TONIGHT THROUGH TUESDAY NIGHT...SEAS AND WINDS CONDITIONS
WILL REMAIN FAIRLY GOOD ACROSS THE GULF WATERS THE REST OF TODAY
INTO TUESDAY NIGHT. SOUTHEAST WINDS WILL DECOUPLE THIS EVENING
BECOMING LIGHT OVER THE GULF WATERS TONIGHT. LIGHT ISOLATED
SHOWERS WILL LIKELY DEVELOP OVER THE OFFSHORE WATERS TUESDAY
AFTERNOON INTO THE EVENING AS A WEAK DISTURBANCE MOVES ACROSS THE
AREA.
WEDNESDAY THROUGH SUNDAY...FAVORABLE MARINE CONDITIONS WILL PERSIST
WEDNESDAY THROUGH THURSDAY EVENING...WITH LIGHT TO MODERATE WINDS
AND LOW TO MODERATE SEAS EXPECTED...AS HIGH PRESSURE INITIALLY
PREVAILS...WITH THE PASSAGE OF A WEAK COLD FRONT THURSDAY EVENING.
THE PASSAGE OF A MORE SIGNIFICANT COLD FRONT THURSDAY NIGHT WILL
RAPIDLY INCREASE WINDS AND BUILD SEAS IN ITS WAKE...AND A SMALL
CRAFT ADVISORY MAY BE NEEDED FOR ALL OR PORTIONS OF THE ADJACENT
COASTAL WATERS OF DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY
THURSDAY NIGHT THROUGH FRIDAY NIGHT. STRONG WINDS AND ROUGH SEAS
WILL PREVAIL FOR SATURDAY AND SUNDAY WITH HIGH PRESSURE OVER THE
GULF OF MEXICO INTERACTING WITH LOWER PRESSURE OVER NORTH TEXAS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
54/63
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1050 PM CST SAT FEB 18 2012
.UPDATE...
HIGH PRESSURE OVER THE GREAT LAKES WITH CLEAR SKIES. ONLY REAL
PROBLEM IS WEAK NORTHEAST WINDS IN LOW LEVELS SHOULD INCREASE LOW
LEVEL MOISTURE SOMEWHAT OFF LAKE MICHIGAN. HOWEVER LOW LEVELS ARE
DRY TO START WITH. NAM FORECAST SOUNDINGS WOULD HOLD OFF ANY
SCATTERED CU UNTIL AROUND NOON SUNDAY. RUC SOUNDINGS ARE QUICKER
AND HAVE A BIT MORE MOISTURE. EITHER WAY EVEN IF SOME CLOUDS
DEVELOP EXPECT MAINLY SCATTERED CONDITIONS.
&&
.AVIATION/06Z TAFS/...
HIGH PRESSURE OVER THE GREAT LAKES WITH CLEAR SKIES. ONLY REAL
PROBLEM IS WEAK NORTHEAST WINDS IN LOW LEVELS SHOULD INCREASE LOW
LEVEL MOISTURE SOMEWHAT OFF LAKE MICHIGAN. HOWEVER LOW LEVELS ARE
DRY TO START WITH. IF SOME CLOUDS DEVELOP EXPECT MAINLY
SCATTERED CONDITIONS.
&&
.PREV DISCUSSION... /ISSUED 326 PM CST SAT FEB 18 2012/
VERY SHORT TERM...TONIGHT AND SUNDAY.
TONIGHT - CONFIDENCE...MEDIUM TO HIGH.
LIGHT BOUNDARY LAYER WINDS AND CLEAR SKIES WILL ALLOW TEMPS TO FALL
INTO THE MID TEENS TO LOWER 20S MOST AREAS. AS THE LOW LEVEL RIDGE
AXIS SETS UP TO THE NORTH TONIGHT...ONSHORE FLOW MAY HAVE JUST
ENOUGH LOW LEVEL MOISTURE TO CAUSE SOME LAKE CLOUDS TO PUSH ASHORE
FROM KMKE SOUTH TO KENW AFT MIDNIGHT TNGT.
SUNDAY - CONFIDENCE...HIGH.
HIGH PRESSURE DOMINATES. LIGHT WIND REGIME WITH 925 TEMPS
SUPPORTING MID/UPPER 30S. 850 TEMPS WARM SO NOT EXPECTING AS MUCH
IN THE WAY OF CU DEVELOPMENT.
SHORT TERM...SUNDAY NIGHT THROUGH TUESDAY NIGHT.
SUNDAY NIGHT AND MONDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
DRY OVER SOUTHERN WISCONSIN SUNDAY NIGHT AND MOST OF MONDAY AS UPPER
RIDGING AND SURFACE HIGH MOVE ACROSS WESTERN GREAT LAKES REGION.
CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPS TO FALL IN THE EVENING
..THEN SLOW OR STEADY OUT AFTER MIDNIGHT AS WEAK SOUTHERLY FLOW
STARTS.
NAM AN OUTLIER WITH FASTER AND STRONGER WITH LEAD SHORT WAVE AND
FARTHER NORTH WITH SURFACE LOW...AS WELL AS ASSOCIATED ISENTROPIC
LIFT AND PRECIPITATION PUSHING INTO WESTERN WISCONSIN MONDAY
AFTERNOON. WILL GO WITH CONSENSUS AND DELAY ANY PRECIPITATION UNTIL
MONDAY EVENING AS DRY AIR AROUND RETREATING SURFACE PREVENTS COLUMN
SATURATION UNTIL AROUND/AFTER 00Z TUESDAY. EARLY SUNSHINE WITH A
SLOWER SPREAD OF CLOUDS INTO SOUTHERN WISCONSIN AND MIXING UP TO 925
MB TEMPERATURES RISING TO 0C TO +1C WILL YIELD LOW TO MID 40 HIGHS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...FORECAST CONFIDENCE MEDIUM.
WILL GO WITH A CONSENSUS BLEND FOR TIMING OF PRECIPITATION INTO THE
REGION WITH THE EAST DRY AND A CHANCE IN THE WEST THROUGH
06Z...THEN LIKELY POPS IN THE WESTERN TWO-THIRDS BY 12Z TUES AND
CHANCE EAST. PRECIPITATION TYPE A CHALLENGE WITH A RAIN/SNOW MIX TO
START...CHANGING OVER TO ALL SNOW AS EVAPORATIVE COOLING DROPS
COLUMN AND WET BULB TEMPS BELOW 0C. WILL KEEP A SLIGHT CHANCE OF
ICE PELLETS/SLEET AS FORECAST SOUNDINGS SHOW SOME RELATIVE WARMTH
IN THE 900-850MB LAYER THAT COULD CAUSE SOME PARTIAL MELTING AND
THEN RE-FREEZING.
LIKELY LIGHT SNOW EVERYWHERE TUESDAY MORNING...CHANGING OVER TO A
MIX AS LOWER PORTION OF COLUMN WARMS ABOVE 0C AND DENDRITE GROWTH
ZONE DRIES OUT. WHILE MOST OF THE ACCUMULATING PRECIPITATION WILL BE
OVER BY 18Z...SECOND SHORT WAVE AND LINGERING CYCLONIC FLOW WILL
KEEP CHANCE POPS IN THE NORTHEAST TAPERING TO A SLIGHT CHANCE IN THE
SOUTHWEST FOR TUESDAY AFTERNOON...WITH ALL PRECIPITATION ENDING BY
00Z WEDNESDAY. THIS WAVE ALSO PREVENTS WEAK COLD AIR ADVECTION FROM
TAKING HOLD UNTIL TUESDAY EVENING. LOWS BY WEDNESDAY MORNING WILL
ONLY FALL INTO THE MID TO UPPER 20S.
LONG TERM...WEDNESDAY THROUGH SATURDAY. FORECAST CONFIDENCE...LOW
TO MEDIUM.
MODELS STILL DEPICT REGION REMAINING UNDER BASE OF BROAD TROUGH WITH
PERIODIC SHORT WAVE ENERGY MOVING THROUGH THE FLOW EVERY 12 TO 24
HOURS...WITH MODEL TIMING/LOCATION DIFFERENCES. OSCILLATING
TEMPERATURES WITH EACH WAVE WILL KEEP PRECIPITATION MIXY...UNTIL
PUSH OF COLDER AIR INTO THE REGION FRIDAY INTO THE WEEKEND DROPS 850
MB TEMPERATURES TO -10C TO -14C BY SATURDAY MORNING.
MODELS STILL HAVING DIFFICULTY RESOLVING A POTENTIALLY STRONG STORM
FOR THE END OF FEBRUARY. 12Z GFS IS TRENDING TOWARD THE 00Z ECMWF
WITH A DEEP SURFACE LOW OVER WESTERN MINNESOTA NEXT SUNDAY
EVENING...TRACKING ENE ACROSS LAKE SUPERIOR/FAR SOUTHERN CANADA A
WEEK FROM THIS MONDAY. 12Z ECMWF HAS BACKED OFF ON STRENGTH OF
WAVE AND ASSOCIATED SURFACE LOW. WAY TOO EARLY...BUT BEARS
WATCHING OVER THE NEXT FEW DAYS.
AVIATION/00Z TAFS/...VFR SKC FOR MUCH OF THE AREA THROUGH SUNDAY.
ONLY QUESTION IS NEAR THE LAKE WHERE DELTA T AND TRAJECTORIES MAY
SUPPORT A WINDOW OF TIME FOR SOME LAKE CLOUDS LATER TONIGHT INTO
SUNDAY MORNING THOUGH CONFIDENCE TOO LOW FOR TAF INCLUSION.
SURFACE HIGH CONTINUES TO BUILD IN TONIGHT AND SUNDAY. OVERALL LESS
CU POTENTIAL FOR MUCH OF SUNDAY WITH WARMING 850 TEMPS AND NO
APPRECIABLE CHANGE IN SURFACE DEW POINTS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...HENTZ
TONIGHT/SUNDAY AND AVIATION/MARINE...COLLAR
SUNDAY NIGHT THROUGH SATURDAY...REM
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
351 AM EST TUE FEB 21 2012...CORRECTION
.SHORT TERM... / TODAY THROUGH WEDNESDAY NIGHT /
POTENT NEGATIVELY TILTED SHORTWAVE OVER MISSOURI WILL TRACK QUICKLY
NEWD THROUGH THE NORTHERN OHIO VALLEY THIS MORNING...WEAKENING A BIT
AS IT BEGINS TO PHASE WITH A NORTHERN STREAM WAVE DROPPING INTO THE
UPPER MIDWEST. THIS MISSOURI NEGATIVE HEIGHT ANOMALY LOOKS
IMPRESSIVE ON WATER VAPOR THIS MORNING WITH A TROWAL CLEARLY
EVIDENT. HOWEVER QUICK MOVEMENT AND SLIGHT WEAKENING TREND WILL
RESULT IN A LIGHTER PCPN AMOUNTS LOCALLY...GENERALLY BTW
0.10-0.25". STILL EXPECTING ABOUT A 2-3 HOUR PERIOD OF ORGANIZED
PCPN...WHICH WILL BE TIED TO A NARROW PLUME OF DEEP MOIST ASCENT
ON THE NOSE OF A ~50 KT LLJ AS CPD`S RAPIDLY LOWER FROM NEAR 200
MB TO 0-5 MB ON THE 290K SFC. USED A MODEL BLEND (MORE WEIGHT TO
HIGH RES GUIDANCE) TO TIME HIGHER POPS THROUGH THE FA. VERY DRY
ANTECEDENT AIRMASS PER 00Z AREA RAOBS AND DYNAMIC NATURE TO SYSTEM
STILL DOES SUPPORT THE CHANCES FOR A RAIN/SNOW MIX NW OF HIGHWAY
24...WITH A BRIEF BURST OF SNOW POSSIBLY SUPPORTING SOME LIGHT
ACCUMS MAINLY ALONG/NORTH OF ROUTE 6 IN INDIANA AND MICHIGAN.
STEEPENING MID LVL LAPSE RATES AND STRONG DYNAMIC/EVAPORATIVE
COOLING SUPPORT THE GOING CHC FOR A BRIEF PERIOD OF WET
SNOW...ESPECIALLY GIVEN TRENDS OF LATEST 05Z HRRR AND 06Z NAM.
THE LOW LVL FLOW WILL VEER SOUTHWESTERLY BEHIND AN OCCLUDED FRONT...
ALLOWING THE LOWEST 3 KFT TO WARM WELL ABOVE FREEZING EVERYWHERE BY
LATE MORNING AND AFTERNOON. ALSO...A TIGHTENING PRESSURE GRADIENT
WILL SUPPORT A BREEZY AFTERNOON WITH GUSTS OF 20-30 MPH POSSIBLE
PER BUFR MOMENTUM TRANSFER PROGS. DEEPER MOISTURE/LIFT WILL EXIT
TO THE EAST LEAVING A LOW OVERCAST AND DRIER CONDITIONS IN ITS
WAKE. HOWEVER..LINGERING MOIST LOW LEVELS AND POSSIBLE WEAK LIFT
FROM A SECONDARY SHORTWAVE COULD STILL SPARK A FEW SHOWERS THIS
AFTERNOON INTO EARLY THIS EVENING.
A SERIES OF SHORTWAVES WILL EMERGE OUT OF A 140 KT PLUS NORTH
PACIFIC UPPER JET THAT WILL HAVE WORKED WELL INLAND INTO THE CENTRAL
PLAINS BY WEDNESDAY/WEDNESDAY NIGHT. THIS WILL SUPPORT MID LVL
TROUGHING INTO THE CENTRAL CONUS AND FAST WESTERLY FLOW ALOFT
LOCALLY. GIVEN NEGATIVE THETA-E ADV IN THE LOW LEVELS TONIGHT WOULD
EXPECT ANY SHORTWAVE ENERGY IN FAST FLOW TO HAVE TROUBLE GENERATING
ANY RAINFALL ON WEDNESDAY. THERE APPEARS TO BE A BETTER CHANCE FOR
MEASURABLE RAINFALL BY WEDNESDAY NIGHT AS A MID LEVEL BAROCLINIC
ZONE LOOKS TO TIGHTEN OVERHEAD.
&&
.LONG TERM...
HIGH ENERGY NEPAC WAVE TRAIN AND ASSOCD/INTENSE UPR JET YIELDING
EXTREME MODEL VARIABILITY W/TIME ONCE AGAIN THIS MORNING AND
ALREADY MANIFESTING ITSELF TO BEGIN THE PD ON DY3 THU. PSBL EPAC
RECON TOMORROW EVENING WILL LEAD TO MITIGATION OF THE UNCERTAINTY
LTR THIS WEEK.
REGARDLESS PRIOR GRID ALIGNMENT STILL HOLDS FOR DY3 GIVEN A CONTD
PREFERENCE/DEPENDENCE ON ECMWF W/CORRESPONDING NOD FM UKMET...BOTH
OF WHICH DIG ROBUST NRN STREAM SW SEEN IN VAPOR NR 48N/163W THIS
MORNING QUICKER AND FARTHER WEST WHILE GFS SYSTEMIC PROGRESSION
BIASES RENDER ITS SOLUTION SUSPECT. THIS HWVR DOES NECESSITATE CHGS
FRI AS MID LVL DEFORMATION ZONE IS MORE LIKELY TO HANG BACK IN
RESPONSE TO SIG ERN OH VALLEY CYCLOGENESIS AT LEAST THROUGH MORNING.
OTHERWISE CHGS BEYOND DY4 DEEMED FUTILE GIVEN RAMPANT MODEL SPREAD
AND UNCERTAINTY.
&&
.AVIATION... / 06Z TAFS /
POTENT NEGATIVE HEIGHT ANOMALY NEAR THE KS/MO BORDER WILL LIFT
NEWD THROUGH THE AREA LATER THIS MORNING. NARROW PLUME OF DEEP
MOIST ASCENT ON NOSE OF THE LOW LEVEL JET AND ASSOCIATED OCCLUDING
WARM FRONT WILL BRING ABOUT RAPIDLY DETERIORATING FLIGHT CONDITIONS
BTW 12-15Z...ALONG WITH A 2-3 HOUR PERIOD OF ORGANIZED LIGHT TO
MODERATE PCPN. EVAPORATIVE/DYNAMIC COOLING ON LEADING EDGE COULD
LEAD TO A BRIEF PERIOD OF IFR/LIFR SNOW AT THE START...BETTER
CHANCES AT SBN. AFTER THAT EXPECT A FEW SHOWERS/DRIZZLE WITH TOP
DOWN SATURATION YIELDING IFR OR LOW END MVFR CEILINGS MID MORNING
INTO MUCH OF THE AFTERNOON. OTHERWISE...WINDS WILL VEER
SOUTHWESTERLY BEHIND THE AFOREMENTIONED OCCLUDED FRONT WITH GUSTS
OF 20-30 KNOTS EXPECTED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...T
AVIATION...STEINWEDEL
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
351 AM EST TUE FEB 21 2012
.SHORT TERM... / TODAY THROUGH WEDNESDAY NIGHT /
POTENT NEGATIVELY TILTED SHORTWAVE OVER MISSOURI WILL TRACK QUICKLY
NEWD THROUGH THE NORTHERN OHIO VALLEY THIS MORNING...WEAKENING A BIT
AS IT BEGINS TO PHASE WITH A NORTHERN STREAM WAVE DROPPING INTO THE
UPPER MIDWEST. THIS MISSOURI NEGATIVE HEIGHT ANOMALY LOOKS
IMPRESSIVE ON WATER VAPOR THIS MORNING WITH A TROWAL CLEARLY
EVIDENT. HOWEVER QUICK MOVEMENT AND SLIGHT WEAKENING TREND WILL
RESULT IN A LIGHTER PCPN AMOUNTS LOCALLY...GENERALLY BTW
0.10-0.25". STILL EXPECTING ABOUT A 2-3 HOUR PERIOD OF ORGANIZED
PCPN...WHICH WILL BE TIED TO A NARROW PLUME OF DEEP MOIST ASCENT
ON THE NOSE OF A ~50 KT LLJ AS CPD`S RAPIDLY LOWER FROM NEAR 200
MB TO 0-5 MB ON THE 290K SFC. USED A MODEL BLEND (MORE WEIGHT TO
HIGH RES GUIDANCE) TO TIME HIGHER POPS THROUGH THE FA. VERY DRY
ANTECEDENT AIRMASS PER 00Z AREA RAOBS AND DYNAMIC NATURE TO SYSTEM
STILL DOES SUPPORT THE CHANCES FOR A RAIN/SNOW MIX NW OF HIGHWAY
24...WITH A BRIEF BURST OF SNOW POSSIBLY SUPPORTING SOME LIGHT
ACCUMS MAINLY ALONG/NORTH OF ROUTE 6 IN INDIANA AND MICHIGAN.
STEEPENING MID LVL LAPSE RATES AND STRONG DYNAMIC/EVAPORATIVE
COOLING SUPPORT THE GOING CHC FOR A BRIEF PERIOD OF WET
SNOW...ESPECIALLY GIVEN TRENDS OF LATEST 05Z HRRR AND 06Z NAM.
THE LOW LVL FLOW WILL VEER SOUTHWESTERLY BEHIND AN OCCLUDED FRONT...
ALLOWING THE LOWEST 3 KFT TO WARM WELL ABOVE FREEZING EVERYWHERE BY
LATE MORNING AND AFTERNOON. ALSO...A TIGHTENING PRESSURE GRADIENT
WILL SUPPORT A BREEZY AFTERNOON WITH GUSTS OF 20-30 MPH POSSIBLE
PER BUFR MOMENTUM TRANSFER PROGS. DEEPER MOISTURE/LIFT WILL EXIT
TO THE EAST LEAVING A LOW OVERCAST AND DRIER CONDITIONS IN ITS
WAKE. HOWEVER..LINGERING MOIST LOW LEVELS AND POSSIBLE WEAK LIFT
FROM A SECONDARY SHORTWAVE COULD STILL SPARK A FEW SHOWERS THIS
AFTERNOON INTO EARLY THIS EVENING.
A SERIES OF SHORTWAVES WILL EMERGE OUT OF THE 140 KT PLUS NORTH
PACIFIC UPPER JET THAT WILL HAVE WORKED WELL INLAND INTO THE CENTRAL
PLAINS BY WEDNESDAY/WEDNESDAY NIGHT. THIS WILL SUPPORT MID LVL
TROUGHING INTO THE CENTRAL CONUS AND FAST WESTERLY FLOW ALOFT
LOCALLY. GIVEN NEGATIVE THETA-E ADV IN THE LOW LEVELS TONIGHT
WOULD EXPECT ANY SHORTWAVE ENERGY IN FAST FLOW TO HAVE TROUBLE
GENERATING ANY RAINFALL ON WEDNESDAY. THERE APPEARS TO BE A BETTER
CHANCE FOR MEASURABLE RAINFALL BY WEDNESDAY NIGHT AS A MID LEVEL
BAROCLINIC ZONE LOOKS TO TIGHTEN OVERHEAD.
&&
.LONG TERM...
HIGH ENERGY NEPAC WAVE TRAIN AND ASSOCD/INTENSE UPR JET YIELDING
EXTREME MODEL VARIABILITY W/TIME ONCE AGAIN THIS MORNING AND
ALREADY MANIFESTING ITSELF TO BEGIN THE PD ON DY3 THU. PSBL EPAC
RECON TOMORROW EVENING WILL LEAD TO MITIGATION OF THE UNCERTAINTY
LTR THIS WEEK.
REGARDLESS PRIOR GRID ALIGNMENT STILL HOLDS FOR DY3 GIVEN A CONTD
PREFERENCE/DEPENDENCE ON ECMWF W/CORRESPONDING NOD FM UKMET...BOTH
OF WHICH DIG ROBUST NRN STREAM SW SEEN IN VAPOR NR 48N/163W THIS
MORNING QUICKER AND FARTHER WEST WHILE GFS SYSTEMIC PROGRESSION
BIASES RENDER ITS SOLUTION SUSPECT. THIS HWVR DOES NECESSITATE CHGS
FRI AS MID LVL DEFORMATION ZONE IS MORE LIKELY TO HANG BACK IN
RESPONSE TO SIG ERN OH VALLEY CYCLOGENESIS AT LEAST THROUGH MORNING.
OTHERWISE CHGS BEYOND DY4 DEEMED FUTILE GIVEN RAMPANT MODEL SPREAD
AND UNCERTAINTY.
&&
.AVIATION... / 06Z TAFS /
POTENT NEGATIVE HEIGHT ANOMALY NEAR THE KS/MO BORDER WILL LIFT
NEWD THROUGH THE AREA LATER THIS MORNING. NARROW PLUME OF DEEP
MOIST ASCENT ON NOSE OF THE LOW LEVEL JET AND ASSOCIATED OCCLUDING
WARM FRONT WILL BRING ABOUT RAPIDLY DETERIORATING FLIGHT CONDITIONS
BTW 12-15Z...ALONG WITH A 2-3 HOUR PERIOD OF ORGANIZED LIGHT TO
MODERATE PCPN. EVAPORATIVE/DYNAMIC COOLING ON LEADING EDGE COULD
LEAD TO A BRIEF PERIOD OF IFR/LIFR SNOW AT THE START...BETTER
CHANCES AT SBN. AFTER THAT EXPECT A FEW SHOWERS/DRIZZLE WITH TOP
DOWN SATURATION YIELDING IFR OR LOW END MVFR CEILINGS MID MORNING
INTO MUCH OF THE AFTERNOON. OTHERWISE...WINDS WILL VEER
SOUTHWESTERLY BEHIND THE AFOREMENTIONED OCCLUDED FRONT WITH GUSTS
OF 20-30 KNOTS EXPECTED.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...T
AVIATION...STEINWEDEL
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1226 AM EST TUE FEB 21 2012
.AVIATION... / 06Z TAFS /
POTENT NEGATIVE HEIGHT ANOMALY NEAR THE KS/MO BORDER WILL LIFT
NEWD THROUGH THE AREA LATER THIS MORNING. NARROW PLUME OF DEEP
MOIST ASCENT ON NOSE OF THE LOW LEVEL JET AND ASSOCIATED OCCLUDING
WARM FRONT WILL BRING ABOUT RAPIDLY DETERIORATING FLIGHT CONDITIONS
BTW 12-15Z...ALONG WITH A 2-3 HOUR PERIOD OF ORGANIZED LIGHT TO
MODERATE PCPN. EVAPORATIVE/DYNAMIC COOLING ON LEADING EDGE COULD
LEAD TO A BRIEF PERIOD OF IFR/LIFR SNOW AT THE START...BETTER
CHANCES AT SBN. AFTER THAT EXPECT A FEW SHOWERS/DRIZZLE WITH TOP
DOWN SATURATION YIELDING IFR OR LOW END MVFR CEILINGS MID MORNING
INTO MUCH OF THE AFTERNOON. OTHERWISE...WINDS WILL VEER
SOUTHWESTERLY BEHIND THE AFOREMENTIONED OCCLUDED FRONT WITH GUSTS
OF 20-30 KNOTS EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 823 PM EST MON FEB 20 2012/
UPDATE...
DELAYED ONSET OF PRECIPITATION PER SLOWER SOLUTION FROM BOTH 18Z NAM
AND LATEST HRRR GUIDANCE. ISENTROPIC PRECIP SHIELD WILL EXPAND
ACROSS THE AREA FROM WEST TO EAST DURING THE EARLY MORNING HOURS
AS MOISTURE PROFILE IMPROVES. INITIAL EVAPORATIVE COOLING COUPLED
WITH DYNAMIC LIFT SHOULD COOL THE COLUMN ENOUGH TO ALLOW FOR A RAIN
SNOW MIX THROUGH THE MORNING HOURS. ALSO ADJUSTED THE RAIN/SNOW
LINE SLIGHTLY NORTHWARD TO ACCOUNT FOR SLIGHTLY WARMER SOLUTION
TUE MORNING AS THE SHORTWAVE CURRENTLY OVER KANSAS PER WV IMAGERY
GOES NEGATIVE TILT AND ATTEMPTS TO PHASE WITH THE NORTHERN STREAM
TROUGH DURING THE MORNING HOURS TUE.
ADJUSTED NEAR TERM TEMPS DOWNWARD TO ACCOUNT FOR MOST RECENT
OBSERVATIONS AND TREND IN LATEST HRRR.
SHORT TERM...
FOCUS IN SHORT TERM CENTERS ON APPROACHING SHORT WAVE TROUGH AND
PRECIPITATION TYPE LATE TONIGHT AND TUESDAY MORNING. 12Z GUIDANCE IN
GOOD AGREEMENT AND LITTLE CHANGE FROM PRIOR RUNS. POTENT SHORT WAVE
CURRENTLY ACROSS CENTRAL PLAINS WILL LIFT NORTHEAST TONIGHT AND TAKE
ON A NEGATIVE TILT AS IT MOVES THROUGH THE GREAT LAKES. THIS WILL
RESULT IN BRIEF BUT INTENSE LIFT ACROSS THE AREA AS LOW LEVEL JET
ADVECTS INTO AREA. ISENTROPIC SURFACES BECOME SATURATED TOWARD 12Z
WITH STRONG LIFT DEPICTED AS WELL.
THERMAL PROFILES CONTINUE TO BE BORDERLINE FOR RAIN AND SNOW WITH
SNOW POSSIBLE AT ONSET GIVEN EVAPORATIVE COOLING PROCESSES WITH VERY
DRY AIRMASS INITIALLY. ONCE SATURATED..STRONG DYNAMIC LIFT MAY BE
ABLE TO KEEP PCPN AS SNOW OR AT LEAST MIXED. PREVIOUS FORECAST HAS
THIS HANDLED WELL WITH EXCELLENT DETAIL IN GRIDS. GIVEN LITTLE
CHANGE IN 12Z RUNS SEE NO REASON TO DEVIATE MUCH FROM PRIOR WEATHER
GRIDS OTHER THAN A FEW MINOR TWEAKS.
SOME SNOW ACCUMULATIONS REMAIN POSSIBLE...ESPECIALLY WEST AND NORTH
BUT TOTALLY DEPENDENT ON STRONG LIFT COOLING COLUMN ENOUGH TO GO
OVER TO ALL SNOW. THIS SYSTEM WILL BE CONVECTIVE IN NATURE AND THIS
ALREADY BEING SEEN UPSTREAM WHERE SOME LIGHTNING HAS BEEN NOTED OVER
EASTERN KS EARLY THIS AFTERNOON. THIS WOULD AID IN CHANGEOVER TO
SNOW. WILL KEEP ACCUMS IN THE ONE INCH OR LESS RANGE WITH THIS
PACKAGE BUT CERTAINLY WILL BE LOOKED AT CLOSELY THIS EVENING AND
OVERNIGHT PRIOR TO ONSET.
LINGERING PCPN EXPECTED ON TUESDAY. SECONDARY WEAKER SHORT WAVE
MOVES THROUGH TUE NIGHT WITH NAM SHOWING SOME LIGHT PCPN WITH IT.
HAVE ADDED A SLIGHT CHANCE POP FOR THIS FEATURE THOUGH IT COULD END
UP ONLY PRODUCING DRIZZLE OR SPRINKLE/FLURRY. FEW CHANGES NEEDED TO
TEMPS.
LONG TERM.../WEDNESDAY THROUGH MONDAY/
ACTIVE PATTERN IN STORE FOR THE EXTENDED PERIOD WITH SEVERAL CHANCES
FOR RAIN/SNOW.
TROUGH WILL BE EXITING THE REGION AT THE START OF THE
PERIOD...LEAVING BEHIND CLEARING SKIES AND A RETURN TO ABOVE NORMAL
TEMPS WITH COLD AIR BEING SHUNTED NORTH. WARM FRONT WILL SETUP TO
THE SOUTH AND MAKE A RUN FOR THE AREA WEDS NGT INTO THURS. MODELS
VARY ON HANDLING OF THIS FEATURE RANGING FROM STALLING OUT ACROSS
THE AREA TO PUSHING WELL NORTH. CHANCE FOR RAIN EXISTS ALONG AND
AHEAD OF THIS BOUNDARY BUT HAVE BEEN HELD IN CHC RANGE GIVEN MODEL
DIFFERENCES. GULF MSTR WILL REMAIN CUT OFF AT THIS POINT BUT NAM12
12Z RUN BRINGS A DECENT WAVE ALONG THE FRONT WITH A TENTH TO QUARTER
INCH OR MORE OF PRECIP THURS AFTERNOON/EVE. FOR SAME REASONS AS
POPS...HAVE KEPT TEMPS IN CHECK ON THURSDAY FOR THE TIME BEING WITH
PROXIMITY OF WARM FRONT AND SERIES OF WEAK DISTURBANCES LIKELY TO
WRECK HAVOC WITH AFTERNOON HIGHS. IF FRONT CAN SURGE NORTH AND SKIES
CLEAR...READINGS WELL INTO THE 50S WILL BE IN STORE.
LONGWAVE TROUGH WILL STRENGTHEN TO THE WEST WITH NORTHERN AND
SOUTHERN STREAM ENERGY MOVING TOWARDS THE AREA THURS NGT INTO FRI.
GFS KEEPS MAIN SFC LOW FURTHER NORTH WITH DEEPENING OF LOW INTO NEW
ENGLAND BY FRI MORNING. ECMWF KEEPS SOUTHERN STREAM SYSTEM STRONGEST
WITH INTENSIFICATION AND POTENTIAL FOR WRAP AROUND/TROWAL PRECIP
INTO THE AREA THURS NGT INTO FRI. HAVE HELD SHY OF LIKELY POPS GIVEN
ABUNDANCE OF SCENARIOS THAT MAY UNFOLD.
COLDER AIR WILL ARRIVE IN THE WAKE OF THE SYSTEM WITH CHANCES FOR
LAKE EFFECT SNOW SHOWERS STILL ON TAP FRI INTO SAT. HAVE KEPT WITH
GENERAL IDEA OF PREV FORECAST. YET ANOTHER WAVE MOVES IN TOWARDS THE
END OF THE PERIOD WITH CHANCE FOR RAIN ARRIVING ONCE AGAIN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...LASHLEY
LONG TERM...FISHER
UPDATE...BENTLEY
AVIATION...STEINWEDEL
AREA FORECAST DISCUSSION
NWS WICHITA KS
1150 PM CST MON FEB 20 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
LOW CLOUDS WILL CONTINUE TO PUSH EAST AND SHOULD CLEAR KSLN/KICT
AT THE ONSET...AND KCNU BEFORE DAYBREAK. APPEARS SOME CIRRUS WILL
SPILL INTO THE AREA AROUND DAYBREAK AS WELL. GUSTY WINDS SHOULD
GRADUALLY DIMINISH OVERNIGHT. VFR CONDITIONS ARE EXPECTED AT ALL
SITES ON TUE WITH WINDS GRADUALLY DIMINISHING. -HOWERTON
&&
.PREV DISCUSSION... /ISSUED 616 PM CST MON FEB 20 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
FRONT WILL CONTINUE TO PUSH EAST WITH STORMS MOVING THROUGH KCNU AT
THE ONSET. SOME LIGHT RAIN AND/OR SNOW SHOWERS WILL BE POSSIBLE THIS
EVENING IN THE WRAP AROUND MOISTURE...MAINLY IN THE VICINITY OF
KRSL...ALTHOUGH NOT OUT OF THE QUESTION AT KSLN/KHUT. KICT IS
LIKELY A BIT FAR REMOVED FROM THE BETTER MOISTURE FOR PRECIPITATION.
RAPID CLEARING IS ANTICIPATED ONCE WAVE MOVES THROUGH. VERY GUSTY WINDS
ARE LIKELY BOTH AHEAD/BEHIND FRONT...WITH WINDS ONLY GRADUALLY
DIMINISHING OVERNIGHT AND DURING THE DAY ON TUESDAY. -HOWERTON
PREV DISCUSSION... /ISSUED 211 PM CST MON FEB 20 2012/
DISCUSSION...
FORECAST CONCERNS...CONVECTIVE TRENDS THRU EARLY EVENING AND
THEN TEMPERATURE ROLLER-COASTER THRU THE END OF THE WEEK.
THIS EVENING/OVERNIGHT
LATEST RUC AND HRRR WOULD SUGGEST 700-900 J/KG CAPE NEAR MAX
HEATING LATE THIS AFTERNOON JUST AHEAD OF SURFACE DRY-LINE/COLD
FRONT ACROSS SOUTH CENTRAL KANSAS. THIS IN COMBO WITH STRONG
DEEP LAYER SHEAR WILL SUPPORT STRONG TO A FEW SEVERE STORMS
INTO THE EARLY EVENING TRANSITIONING FROM PORTIONS OF CENTRAL
AND SOUTH CENTRAL KANSAS ACROSS THE SOUTHERN FLINT HILLS. SEE
LATEST HAZARDOUS WEATHER OUTLOOK AND SHORT TERM GRAPHICAST FOR
MORE DETAILS.
OTHERWISE...WINDS SHOULD REMAIN STOUT EVEN BEHIND THE FRONT
THIS EVENING...NEAR ADVISORY THRESHOLDS...SO 06Z/MIDNIGHT
EXPIRATION LOOKS FINE.
TUESDAY-FRIDAY
A RATHER SIGNIFICANT WARMING TREND IS EXPECTED THROUGH THE
MID-WEEK PERIOD WITHIN THE DEVELOPING MEAN WESTERLY FLOW
AHEAD OF THE NEXT UPPER TROF. THIS SUPPORTS THE GOING MAXS...
APPROACHING 70F IN MANY AREAS ON WEDNESDAY. THIS WILL BE
FOLLOWED BY A MODERATE STRENGTH COLD FRONT ON THURSDAY WITH
TEMPERATURES CLOSER TO SEASONAL CLIMO FOR THE END OF THE WEEK.
SATURDAY-MONDAY
A MORE ZONAL UPPER FLOW PATTERN TO START OUT THE WEEKEND
WITH TEMPERATURES AGAIN MODERATING ABOVE SEASONAL CLIMO. THE
MEDIUM RANGE MODELS GENERALLY SUPPORT MEAN TROUGHING ALOFT
ACROSS THE WESTERN CONUS LATE IN THE PERIOD...WITH THE ECMWF
A BIT DEEPER WITH THIS TROF BY MONDAY. THE MAIN CHALLENGE IS
THE TIMING OF THE ASSOCIATED COLD FRONTAL BOUNDARY SOUTH
ACROSS THE PLAINS...AND POTENTIAL OF SIGNIFICANT COOLING
BEHIND THIS FRONT. FOR NOW FORECAST CONSENSUS WAS TO TREND
COOLER BY MONDAY...THOUGH CONFIDENCE IS RATHER LOW ON THE
MAGNITUDE...WITH POTENTIAL FOR MUCH COLDER AIR. WILL ALSO
CARRY SLIGHT TO MODEST POPS ALONG/JUST BEHIND THIS SOUTHWARD
SAGGING FRONT FOR NOW WHICH CAN BE REFINED WITH LATER RUNS.
DARMOFAL
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MVFR CIGS WILL HANG TOUGH THROUGH AT LEAST MID-
AFTERNOON...ALTHOUGH SOME CLEARING FROM THE WEST IS EXPECTED AS A
STRONG COLD FRONT CONTINUES TO APPROACH FROM THE WEST. AHEAD OF
THE FRONT...VERY STRONG/GUSTY SOUTHERLY WINDS WILL PREVAIL.
ADDITIONALLY...SCATTERED THUNDERSTORMS SHOULD DEVELOP AROUND
20-21Z JUST WEST OF THE I-135 CORRIDOR. STORM MOTION WILL BE TO
THE NORTHEAST AT 50-60 MPH. A FEW STORMS WILL LIKELY PRODUCE SMALL
TO MODERATE SIZE HAIL UP TO DIME/QUARTER SIZE...ALONG WITH GUSTY
WINDS. THE STORMS WILL MOVE RAPIDLY NORTHEAST...WITH VERY STRONG
WEST/NORTHWEST WINDS DEVELOPING BY EARLY THIS EVENING BEHIND THE
COLD FRONT SWEEPING EAST ACROSS THE AREA...ALONG WITH MVFR TO LOW
VFR CIGS. CIGS AND WINDS WILL DISSIPATE BY LATE EVENING FROM WEST
TO EAST...CLEARING KCNU LAST.
KLEINSASSER
FIRE WEATHER...
STRONG WINDS WILL CONTINUE TO ELEVATE FIRE DANGER THROUGH THE
EVENING ACROSS MUCH OF THE AREA. DRIER AIR AND DIURNALLY GUSTY
WINDS MAY LEAD TO PERIODS OF ELEVATED FIRE DANGER DURING THE
AFTERNOON HOURS FROM TUESDAY THROUGH THURSDAY.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 28 57 33 68 / 20 0 0 0
HUTCHINSON 27 57 32 69 / 20 0 0 0
NEWTON 29 56 34 68 / 30 0 0 0
ELDORADO 30 56 34 67 / 30 0 0 0
WINFIELD-KWLD 29 58 33 69 / 20 0 0 0
RUSSELL 26 56 32 69 / 40 0 0 0
GREAT BEND 26 56 32 69 / 30 0 0 0
SALINA 28 57 33 69 / 50 0 0 0
MCPHERSON 28 57 33 68 / 30 0 0 0
COFFEYVILLE 33 59 34 69 / 80 0 0 0
CHANUTE 32 57 34 67 / 80 0 0 0
IOLA 32 56 34 66 / 80 0 0 0
PARSONS-KPPF 33 58 34 68 / 80 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1119 PM CST MON FEB 20 2012
...UPDATE FOR AVIATION...
.UPDATE...
ISSUED AT 933 PM CST MON FEB 20 2012
WINDS CONTINUE TO DECREASE ACROSS NORTH CENTRAL KANSAS THIS
EVENING. GIVEN THE TRENDS FROM THE WINDS AT HAYS, GREAT BEND, AND
PRATT WILL ALLOW THE WIND ADVISORY EXPIRE AT 10 PM.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 235 PM CST MON FEB 20 2012
FORECAST CONCERNS ARE THE SNOW AND HIGH WINDS LATE THIS AFTERNOON
INTO EARLY EVENING. THIS MORNINGS UA ANALYSIS SHOWED A STRONG
UPPER TROUGH ALONG THE EASTERN SLOPES OF THE ROCKIES WITH A CLOSED
CIRCULATION SHOWING UP OVER NORTHEAST COLORADO. THIS FEATURE HAS BEEN
MOVING STEADILY EAST THROUGH WESTERN KANSAS AND THE OK/TX PANHANDLES
THIS AFTERNOON. RUC ANALYSIS SHOWED A FAIRLY INTENSE MID LEVEL
VORT MAX ACROSS THE AREA WITH STRONG PVA AND MID LEVEL UVV OCCURRING
OVER SOUTHWEST KANSAS. THIS LINES UP WELL WITH AN AREA OF LIGHT
TO MODERATE SNOW WHICH HAS BEEN TRANSLATING EAST THROUGH SOUTHWEST
KANSAS TODAY.
THE AREAS OF RAIN AND SNOW SHOULD CONTINUE TO WORK EASTWARD ACROSS
SOUTHWEST AND TOWARD CENTRAL KANSAS THROUGH THE LATE AFTERNOON
HOURS BUT SHOULD BEGIN TO DIMINISH RAPIDLY TOWARD SUNSET AS THE
TROUGH AXIS MOVES EAST OF THE AREA.
HIGH WINDS HAVE BEEN SLOW TO MATERIALIZE ACROSS SOUTHWEST KANSAS
THIS AFTERNOON PARTLY DUE TO THE WIDESPREAD CLOUD COVER AND
REDUCED MIXING. AM STILL CONCERNED THAT WE COULD SEE A WINDOW OF
OPPORTUNITY AS THE GRADIENT INCREASES ON THE BACKSIDE OF THE LOWER
ATMOSPHERIC TROUGH AXIS. RUC MODEL SOUNDINGS THROUGHOUT THE DAY
HAVE BEEN SHOWING 50-60 KNOT WINDS DEVELOPING IN THE 850-875 MB
LAYER THROUGH THE 21Z-01Z TIME PERIOD. WILL KEEP THE CURRENT
HEADLINES IN PLACE THROUGH THE EARLY EVENING HOURS.
THE UPPER LEVEL SHORTWAVE TROUGH WILL MOVE RAPIDLY EAST OUT OF THE
PLAINS TONIGHT WITH WESTERLY FLOW OVER THE HIGH PLAINS. ANOTHER
BROAD SHORTWAVE TROUGH IS FORECAST TO MOVE SOUTHEAST OVER THE
CENTRAL CONUS DURING THE DAY TUESDAY. ONLY SOME SCATTERED HIGH
CLOUDINESS IS EXPECTED WITH THE SHORTWAVE. LOW LEVEL DOWNSLOPE
FLOW SHOULD HELP BOOST TEMPERATURES INTO THE 55 TO 60 DEGREE RANGE
FOR AFTERNOON HIGHS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 543 PM CST MON FEB 20 2012
NORTHWESTERLY MID TO HIGH LEVEL FLOW WILL DEVELOP BY TUESDAY NIGHT
AND PERSIST THROUGH FRIDAY. THIS IS USUALLY A DRY REGIME FOR
WESTERN KANSAS AS THE GULF OF MEXICO TENDS TO BE SHUT OFF.
DOWNSLOPE WESTERLY LOW-LEVEL FLOW WILL DEVELOP TUESDAY NIGHT WITH
850MB TEMPERATURES RISING TO BETWEEN 6 AND 9C. HOWEVER, GIVEN THE
EXPECTED CLEAR SKIES AND ONLY 5 TO 10 KT WINDS, TEMPERATURES WILL
PROBABLY STILL DROP INTO THE LOWER 30S. WEDNESDAY WILL BE A WARM DAY
WITH WESTERLY DOWNSLOPE FLOW PERSISTING AS SURFACE LOW PRESSURE DEVELOPS
ACROSS NEBRASKA AHEAD OF A SHORTWAVE TROUGH. IN THESE SITUATIONS IN
LATE WINTER AND EARLY SPRING TEMPERATURES TYPICALLY GET WARMER THAN
ANY OF THE MODELS INDICATE. GIVEN THE EXPECTED WESTERLY SURFACE
WINDS AT 10 TO 20 KTS, A DEEP, DRY ADIABATIC LAYER WILL DEVELOP.
TEMPERATURES OUGHT TO EASILY REACH INTO THE UPPER 60S TO LOWER 70S.
AS IS TYPICAL IN DOWNSLOPE REGIMES WHEN THE WEST WINDS PROGRESS ALL
THE WAY INTO CENTRAL KANSAS, THE VERY WARMEST READINGS MAY BE ON THE
LOWER TERRAIN OF SOUTHERN CLARK, COMANCHE AND BARBER COUNTIES
(ELEVATIONS 1500-2000FT) AS OPPOSED TO DODGE CITY (2600FT), GARDEN
CITY (2900FT) AND SYRACUSE (3300FT).
COOL SURFACE HIGH PRESSURE WILL MOVE INTO WESTERN KANSAS LATE
WEDNESDAY NIGHT AND THURSDAY IN THE WAKE OF THE AFOREMENTIONED
SHORTWAVE TROUGH. LOW TEMPERATURES WEDNESDAY NIGHT WILL BE TRICKY.
IT COULD ACTUALLY GET COLDER AHEAD OF THE FRONT IF WINDS CAN DROP OFF
TO LIGHT AND VARIABLE. VERTICAL MIXING IMMEDIATELY BEHIND THE FRONT
MAY KEEP LOCATIONS NEAR INTERSTATE 70 WARMER. BUT THIS IS SUBJECT
TO CHANGES IN FRONTAL TIMING. IN THE ABSENCE OF ARCTIC AIR, HIGH
TEMPERATURES SHOULD COOL DOWN TO NEAR SEASONAL VALUES, WITH HIGHS IN
THE UPPER 40S TO LOWER 50S THURSDAY AND UPPER 40S TO MID 50S FOR
FRIDAY.
BY SATURDAY AND SUNDAY, THE MODELS INDICATE UPPER-LEVEL TROUGHING
DEVELOPING ACROSS THE WESTERN UNITED STATES, THE SPEED AND AMPLITUDE
OF WHICH IS DIFFERENT DEPENDING ON THE MODEL. THIS SYSTEM WILL BRING
SOME ARCTIC AIR SOUTHWARD INTO THE NORTHERN OR EVEN CENTRAL PLAINS BY
SUNDAY. HOW FAST THIS ARCTIC FRONT MOVES THROUGH KANSAS IS
UNCERTAIN. BUT IT LOOKS LIKE TEMPERATURES WILL BE GETTING MUCH
COLDER SOMETIME BETWEEN SUNDAY AND TUESDAY (FEBRUARY 26-28TH). BUT
THERE WILL BE A VERY SHARP TEMPERATURE GRADIENT ALONG THE LEADING
EDGE OF THE ARCTIC AIR. SO SOME PLACES IN THE SOUTHERN PLAINS
(POSSIBLY INCLUDING SOUTHERN KANSAS) COULD GET VERY WARM SUNDAY OR
MONDAY (POSSIBLY 70S) BEFORE THE ARCTIC AIR ARRIVES. IT IS TOO EARLY
TO TELL IF ANY PRECIPITATION WILL ACCOMPANY THIS SYSTEM. AT THIS
POINT IT APPEARS THAT MOST OF THE PRECIPITATION WILL BE IN THE WARM
SECTOR AND WELL EAST OF HERE. HOWEVER, IF THE SYSTEM IS SLOWER AND
FURTHER SOUTH THAN WE CURRENTLY EXPECT, THEN SOME RAIN/SNOW WOULD BE
POSSIBLE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1112 PM CST MON FEB 20 2012
A DRY UPPER LEVEL SHORTWAVE TROUGH WILL MOVE ACROSS WESTERN KANSAS
TODAY AND TONIGHT WITH ONLY A FEW MID AND HIGH LEVEL CLOUDS. EXPECT
VFR CONDITIONS WITH LIGHT NORTHWESTERLY TO WESTERLY WINDS. THE
WINDS COULD PICK UP TO 15 TO 25 KTS BY 15-18Z TUESDAY AT KYHS BUT
RAPIDLY DROP BY SUNSET.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 22 58 30 71 / 90 0 0 0
GCK 20 56 28 70 / 0 0 0 0
EHA 21 57 33 70 / 0 0 0 0
LBL 21 58 30 72 / 0 0 0 0
HYS 25 56 30 69 / 0 0 0 0
P28 27 60 32 73 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BURGERT
SHORT TERM...GERARD
LONG TERM....FINCH
AVIATION...KRUSE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1224 AM EST TUE FEB 21 2012
.UPDATE...
ISSUED AT 946 PM EST MON FEB 20 2012
MAIN CONCERN OVERNIGHT INTO TUE IS ONSET OF -SN. WATER VAPOR IMAGERY
SHOWS A VIGOROUS SRN SHORTWAVE OVER ERN KS. THIS WAVE IS OUT OF
PHASE WITH THE NRN STREAM TROF OVER SASKATCHEWAN AND THE WRN
DAKATOS. WITH VIGOROUS SRN SHORTWAVE WRAPPING UP AND HEADING MORE
E THAN NE...WOULD EXPECT CURRENT STRONG SOUTHERLY FLOW AND
AGGRESSIVE NORTHWARD PUSH OF MOISTURE/PCPN INTO THE UPPER
MISSISSIPPI VALLEY TO DIMINISH WITH TIME AS THE OUT OF PHASE WAVES
SHIFT E OVERNIGHT INTO TUE. THIS WOULD ALLOW VERY DRY AIRMASS AT THE
LOWER LEVELS PER REGIONAL 00Z SOUNDINGS TO HAVE AN INCREASING
INFLUENCE ON SLOWING/ERODING FRONT EDGE OF PCPN AS IT TRANSLATES
EASTWARD...ESPECIALLY SINCE EASTERLY COMPONENT TO LOW-LEVEL WINDS
WILL HELP MAINTAIN A FEED OF DRY AIR. INHERITED FCST APPEARED TO
HAVE A GOOD HANDLE ON THIS IDEA...SO ONLY MINOR FCST CHANGES HAVE
BEEN MADE TO OVERALL TIMING OF -SN OVERNIGHT INTO TUE. SNOW
ACCUMULATIONS THRU TUE WILL BE ON THE LIGHT SIDE DUE TO SPLIT ENERGY
AND DUE TO ANTECEDANT DRY AIRMASS DELAYING ONSET OF SNOW AT THE SFC.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 346 PM EST MON FEB 20 2012
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR RDG OVER THE
GREAT LKS BTWN TROF IN SE CAN AND ANOTHER IN THE PLAINS. AT THE
SFC...UPR MI LIES UNDER A SHARPENING PRES GRADIENT BTWN SFC HI PRES
OVER OH AND LOWER PRES IN THE PLAINS UNDER THE TROF. ALTHOUGH HI
CLDS ARE STREAMING OVHD IN THE SW FLOW ALF...12Z RAOBS TO THE S AT
GRB/MPX/AND QUAD CITIES IA SHOW DRY LO/MID LVLS. SINCE THE SUN IS
JUST FILTERED A BIT BY THESE HI CLDS...TEMPS HAVE REBOUNDED TO WELL
ABV NORMAL LVLS AGAIN AND WELL INTO THE 30S AT MOST SPOTS EARLY THIS
AFTN. ALTHOUGH THERE A LARGER SCALE TROF IN THE PLAINS...SEVERAL OUT
OF PHASE SHRTWVS ARE PRESENT WITHIN THE BROADER AREA OF LOWER HGTS.
THE STRONGEST OF THESE IS OVER THE SCNTRL PLAINS...WITH ANOTHER OVER
SASKATCHEWAN.
MAIN FCST CONCERNS THRU TUE REVOLVE ARND PCPN CHCS TNGT/TUE RELATED
TO EWD PROGRESSION OF PLAINS TROF AND EMBEDDED SHRTWVS. RECENT MODEL
RUNS ARE IN FAIRLY GOOD AGREEMENT SHOWING SHRTWVS/ASSOCIATED SFC LO
CENTERS REMAINING OUT OF PHASE THRU TUE...WHICH WILL LIMIT PCPN
TOTALS OVER THE CWA. IN GENERAL...FOLLOWED THE GFS FOR FCST DETAILS
AT THIS MODEL SHOWS MORE PERSISTENT LLVL DRY AIR WITH MORE MSTR TIED
TO THE STRONGER SRN DISTURBANCE FCST TO TRACK THRU THE LOWER LKS.
TNGT...SHRTWV OVER SASKATCHEWAN IS FCST TO DIG TOWARD MN BY 12Z
WHILE SRN DISTURBANCE MOVES INTO ILLINOIS. PREFERRED GFS SHOWS MORE
IMPRESSIVE QVECTOR CNVGC TENDING TO REMAIN TO THE W AND S OF THE FA.
SINCE SLOWLY BACKING WINDS FM THE SSW TOWARD THE SE WL MAINTAIN LLVL
DRY AIR FEED...PREFERRED GFS MODEL INDICATES PERSISTENT DRY WEDGE IN
THE LLVLS PERSISTING THRU 12Z OVER UPR MI. SO EXCEPT FOR WRN LK
SUP...WHICH WL BE CLOSEST TO INCOMING DYNAMICS ASSOCIATED WITH THE
NRN DISTURBANCE...TENDED TO CUT POPS OVER THE CWA. DESPITE LINGERING
DRY AIR IN THE LLVLS...A STRONGER SW FLOW AND THICKENING HI CLDS WL
PREVENT TEMPS FM FALLING AS SHARPLY AS THE LAST FEW NIGHTS.
TUE...WHILE SRN SHRTWV MOVES ENEWD WELL S OF THE FA...THE NRN
DISTURBANCE IS FCST TO DRIFT EWD INTO THE UPR LKS. WITH INCRSG DPVA/
LLVL MOISTENING/LARGE SCALE QVECTOR CNVGC/SOME UPR DVGC...EXPECT
INCRSG POPS TOWARD CATEGORICAL IN THE AFTN. HOWEVER...SINCE MOST OF
THE DYNAMICS WL BE SPENT SATURATING THE INITIALLY DRY LO/MID LVLS...
PCPN AMNTS WL BE RELATIVELY LGT AND UNDER 0.25 INCH. ALTHOUGH MAX
TEMPS WL TOP OUT OVER 32 ALMOST EVERYWHERE...DYNAMIC/WBLB COOLING
SHOULD KEEP PCPN IN THE FORM OF SN PER GFS FCST SNDGS AND H100-85
THKNS/WBZ HGT BLO CRITICAL LVLS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 346 PM EST MON FEB 20 2012
THE SLOW MOVING 500MB LOW OVER CENTRAL SASKATCHEWAN THIS AFTERNOON
WILL BE OVER N MN/W LAKE SUPERIOR AT 00Z WEDNESDAY...SETTING US UP
FOR AN ACTIVE PERIOD OF LIGHT SNOW SHOWERS.
EXPECT THE 500MB LOW TO BE DIRECTLY OVER UPPER MI AT 06Z
WEDNESDAY...WITH THE 20/06Z GFS SHOWING MORE OF AN OPEN WAVE INSTEAD
OF A CLOSED LOW. THE RESULT IS A MORE PROGRESSIVE /THAN THE
CONSENSUS AND ITS 20/00Z RUN/. EVEN AT THE SFC THE LOW IS QUITE A
BIT FARTHER TO THE SOUTH...BUT WITHIN REASON. ANOTHER DISCREPANCY
WOULD BE FROM THE 20/06Z NAM...WITH IS ON THE SLOW SIDE NEARLY RIGHT
OFF THE BAT. THE DIFFERENCE BETWEEN THE PLACEMENT OF THE FASTER GFS
AND SLOWER NAM IS ROUGHLY 240MI. EXPECT THE ELONGATED TO DOUBLE
BARREL SFC LOW STRETCHING FROM N MN TO SE IA AT 12Z TUESDAY TO
DEEPEN ACROSS E LAKE SUPERIOR TUESDAY NIGHT...BEFORE SLIDING ALMOST
DIRECTLY E INTO S QUEBEC LATE TUESDAY NIGHT INTO WEDNESDAY. WHILE A
SFC TROUGH WILL LINGER BEHIND THE EXITING LOW...IT WILL BE OF SHORT
DURATION...AS A SFC RIDGE QUICKLY BUILDS IN WEDNESDAY AFTERNOON
AHEAD OF THE NEXT LOW. ANOTHER HINDRANCE TO HEAVY SNOW WILL BE THE
RELATIVELY MILD 850MB TEMPS NEAR -8C...AND PREDOMINANT WNW WINDS
BEHIND THE SFC LOW. WHILE LAKE ENHANCEMENT WILL BE POSSIBLE AS THE
LOW MOVES OVERHEAD...SHIFTING WINDS WILL DETER SIGNIFICANT AMOUNTS.
THE BEST CHANCE OF RECEIVING 2-5 INCHES WOULD BE FROM IWD TO
CMX.
THE NEXT 500MB FEATURE OF IMPORTANCE WILL BE IN THE FORM OF A S
CENTRAL CANADIAN TROUGH WEDNESDAY NIGHT...SLIDING ACROSS THE UPPER
GREAT LAKES THURSDAY AFTERNOON. THE CONSENSUS IS TO HAVE THIS TROUGH
DEEPEN INTO A LOW UPPER MI FRIDAY...BEFORE MOVING INTO S QUEBEC
FRIDAY NIGHT. WHILE THE ORIGINS OF THE SFC LOW...OVER SASKATCHEWAN
WEDNESDAY AFTERNOON WOULD INDICATE ANOTHER LOW WITH LITTLE IN THE
WAY OF MOISTURE TO WORK WITH...ITS PROGRESSION WILL ALLOW THE GULF
TO OPEN UP. EXPECT THE SFC LOW TO RESIDE BETWEEN CENTRAL WI/CENTRAL
LOWER MI/CENTRAL UPPER MI AT 18Z THURSDAY /WITH THE ECMWF FARTHER
SOUTH THAN THIS/...AND A COLD FRONT DRAGGING ACROSS IL/MO/AND INTO
NE TX. THE SFC LOW SHOULD DEEPEN AS IT SLIDES EAST OF OUR
AREA...THURSDAY NIGHT NEAR THE LOWER GREAT LAKES...AND FRIDAY
AFTERNOON/EVENING OVER S QUEBEC. AS THE SYSTEM DEEPENS AND TAPS INTO
ADDITIONAL MOISTURE OFF THE ATLANTIC IT SHOULD WRAP IN STEADY N
WINDS SLOWLY BECOMING NW...AND PLENTY OF COLD AIR TO OUR REGION
FRIDAY AFTERNOON THROUGH SATURDAY NIGHT. 850MB TEMPS AT THIS POINT
THE PRESSURE GRADIENT BECOMES FAIRLY WEEK WITH A SFC RIDGE NEARLY
OVERHEAD.
PRECIPITATION TYPE MAY BE A CONCERN FOR THIS SYSTEM OVER THE SE
CORNER OF THE CWA RIGHT ALONG LAKE MICHIGAN. 850MB TEMPS OF THE
20/06Z GFS ARE AROUND -4C...WITH THE MNM SOUNDING SHOWING
INDICATIONS OF RA FROM MID MORNING THROUGH THE REMAINDER OF THE
DAYTIME HOURS THURSDAY. THE EVEN WARMER/MORE WRAPPED UP 20/00Z
CANADIAN WOULD HAVE 850MB TEMPS AROUND -2C OVER THE ENTIRE CWA
AROUND 12Z THURSDAY...LINGERING EAST AS THE LOW EXITS EARLY THURSDAY
EVENING. WILL NOT CONCENTRATE TOO MUCH ON THIS...AS THERE ARE LARGER
DISCREPANCIES...WITH THE NAM AND ECMWF NOT TOO ENTHUSED ABOUT THE
NORTHERN EXTENT OF THE SYSTEM...WITH THE BULK OF THE MOISTURE
REMAINING OVER IL/IN/OH. BOTH THE GFS AND ECMWF SHOW GOOD RUN TO RUN
CONSISTENCY...WITH A BLEND LOOKING REASONABLE AT THIS TIME. THE 12Z
RUNS OF THE GFS AND ECMWF KEPT WITH A MORE SOUTHERLY SOLUTION FOR
THIS SYSTEM...CLOSER TO THE 00Z RUN OF THE ECMWF. THIS TREND WOULD
CONTINUE TO LIMIT THE MENTION OF RAIN NEAR LAKE MICHIGAN. NO MATTER
WHICH SOLUTION OR GROUP OF SOLUTIONS IS PREFERRED...850MB TEMPS
SHOULD FALL BETWEEN -12 AND -16C FROM FRIDAY NIGHT ON...WITH
FAVORABLE WINDS OFF LAKE SUPERIOR PRODUCING LIGHT TO MODERATE SNOW
SHOWERS.
BEYOND FRIDAY NIGHT THE 20/06Z GFS AND 20/00Z ECMWF BECOME OUT OF
PHASE. THIS IS BEST INDICATED BY THE LATE SATURDAY AFTERNOON/SUNDAY
NIGHT TRENDS AT 500MB OVER THE GREAT LAKES...WITH THE ECMWF
INDICATING A RIDGE AND THE GFS A TROUGH. THIS IS MAINLY DUE TO THE
HANDLING OF THE LOW EJECTING E SATURDAY. THE ECMWF IS ON THE QUICKER
SIDE...WHILE THE LAST 2 GFS RUNS CONTINUE TO DEEPEN THE LOW AS IT
SHIFTS INTO FAR EASTERN CANADA. AS A RESULT...WILL NOT TRY TO PIN
POINT SPECIFICS BEYOND SATURDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1224 AM EST TUE FEB 21 2012
LLWS WILL REMAIN IN THE FCST AT KCMX/KSAW FOR THE NEXT FEW HRS AS
KMQT VAD WIND PROFILE INDICATES 35KT S WIND AT 500FT AGL. EXCEPTION
IS AT KIWD AS SFC WINDS HAVE REMAINED GUSTY THERE. ATTENTION THEN
TURNS TO APPROACHING LOW PRES TROF. LOW-LEVEL DRY AIR WILL CONTINUE
TO SLOW EASTWARD PROGRESS OF -SN IN NW WI...BUT WEAK LEAD SHORTWAVE
LIFTING THRU SE MN INTO FA NW WI MAY BE SUFFICIENT TO BRING A PERIOD
OF -SN/MVFR CONDITIONS TO KIWD AND POSSIBLY KCMX OVERNIGHT.
OTHERWISE...MVFR CONDITIONS PROBABLY WON`T DEVELOP UNTIL LATE
MORNING AS MIDLEVEL TROF MOVES CLOSER. CONDITIONS MAY DROP TO IFR IN
THE AFTN/EVENING AS LOW-LEVELS SATURATE. FOR NOW...ONLY OPTED FOR
IFR AT KCMX AFTER COLD FRONT PASSES IN THE EVENING AND WINDS SHIFT
TO AN UPSLOPE WESTERLY DIRECTION.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 346 PM EST MON FEB 20 2012
WITH AN UNSEASONABLY WEAK PRES GRADIENT FORECAST THIS WEEK...EXPECT
WINDS NO HIER THAN 25 KTS. NO GALES ARE FORECAST IN THE NEAR FUTURE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1056 PM CST MON FEB 20 2012
.UPDATE...
ISSUED AT 834 PM CST MON FEB 20 2012
MADE SOME ADJUSTMENTS TO GOING FORECAST TO INCLUDE ISOLATED THUNDERSTORMS
OVER CENTRAL AND SOUTHEAST MISSOURI THIS EVENING...AND ADJUSTED POPS
BASED ON GOING RADAR OBSERVATIONS. LINE OF SHOWERS AND SCATTERED
THUNDERSTORMS ACROSS SOUTHWEST AND WEST CENTRAL MISSOURI THAT
PRODUCED ISOLATED SEVERE WIND GUSTS EARLIER CONTINUES TO MOVES
NORTHEAST THIS EVENING AND WILL LIKELY MOVE INTO CENTRAL AND
NORTHEAST MISSOURI BETWEEN 9-10PM. WHILE THE INTENSITY OF THE
THUNDERSTORMS SHOULD DECREASE AS IT MOVES INTO DRIER
AIR...STRENGTH OF ASCENT WITH NEGATIVELY TILTING UPPER TROUGH AND
DECENT 925-850MB MOISTURE CONVERGENCE SHOULD KEEP THE LINE OF
SHOWERS GOING. RADAR INTERPOLATION AND HRRR FORECAST REFLECTIVITY
SUGGESTS THAT THIS LINE OF SHOWERS WILL CONTINUE TO MOVE EAST AND
LIKELY EXIT THE CWA BY 3 AM. I HAVE ADDED ISOLATED THUNDERSTORMS
TO PARTS OF CENTRAL AND SOUTHEAST MISSOURI THIS EVENING BASED ON
THE STRENGTH OF THE ASCENT AND WEAK INSTABILITY SEEN IN THE RUC.
REST OF THE FORECAST STILL LOOKS GOOD.
BRITT
&&
.SHORT TERM...
ISSUED AT 239 PM CST MON FEB 20 2012
(TONIGHT)
MID AND HIGH CLOUDS MOVING INTO FORECAST AREA THIS AFTERNOON AHEAD
OF NEXT WEATHER SYSTEM. SOME SHOWERS HAVE DEVELOPED OVER WESTERN
MO AHEAD OF COLD FRONT...BUT MAKING VERY LITTLE PROGRESS TO THE
EAST YET UNTIL SHORTWAVE BEGINS TO LIFT OUT. SO BACKED OFF ON ONSET
OF PCPN WITH RAIN MOVING INTO CENTRAL MO BY 01Z...ALONG
MISSISSIPPI RIVER BY 04Z AND EASTERN PORTIONS OF FORECAST AREA BY
06Z. MODELS SHOWING LITTLE IN THE WAY OF INSTABILITY WITH THIS
SYSTEM OVER OUR AREA...SO REMOVED MENTION OF THUNDERSTORMS. ONCE
THIS SYSTEM BEGINS TO MAKE SOME PROGRESS TO THE EAST ONLY EXPECT
IT TO RAIN FOR A FEW HOURS MOST LOCATIONS...WITH ONLY A TENTH OF
AN INCH OF QPF...BEFORE COMING TO AN END TOWARDS DAYBREAK. AS FOR
LOW TEMPS...INITIALLY COLD AIR LAGGING BEHIND THIS SYSTEM...SO
LOWS TO ONLY DIP INTO THE UPPER 30S TO AROUND 40.
BYRD
&&
.LONG TERM...
ISSUED AT 350 PM CST MON FEB 20 2012
(TUESDAY THROUGH NEXT MONDAY)
THE LONGWAVE UPPER LEVEL TROF IS EXPECTED TO STILL SETTLE IN FOR
MUCH OF THE WORK WEEK BEGINNING TUESDAY AND MAINTAINING ITSELF UNTIL
FRIDAY WITH A FEW GENERALLY WEAK SHORTWAVES SWINGING THRU. THIS
WILL SCOOT A FEW FRONTS THRU AT A FRANTIC PACE BUT MOISTURE WILL BE
PRETTY LIMITED DURING THIS TIME ALTHOUGH IT APPEARS UPPER LEVEL
IMPULSE ON THURSDAY SHOULD BE STRONG ENOUGH WITH ENOUGH MOISTURE TO
WARRANT CONTINUED MENTION OF CHANCE POPS. FAIRLY DEEP MIXING
TUESDAY THRU THURSDAY WILL RESULT IN CONTINUED MILD TEMPS FOR LATE
FEBRUARY...WITH WARMEST MOS VALUES FAVORED...RESULTING IN 50S AND
SOME 60S FOR MAXES. AND TUESDAY/S VALUES ARE DESPITE CDFNT MOVING
THRU LATER TONIGHT...AS RESULTANT TEMPS WILL BE NEARLY IDENTICAL...
PERHAPS A TAD HIGHER...THAN PERSISTENCE.
NWLY UPPER LEVEL FLOW COUPLED WITH HI PRES INVOF THE FA WILL RESULT
IN QUIET WX FOR MUCH OF THE UPCOMING WEEKEND...WITH TEMPS REBOUNDING
FROM NEAR AVERAGE ON FRIDAY TO ABOVE AVERAGE AGAIN BY SUNDAY. UPPER
LEVEL FLOW SHIFTS SWLY BY NEXT MONDAY WHERE A STORMIER PATTERN
APPEARS IN THE OFFING.
TES
&&
.AVIATION...
ISSUED AT 1030 PM CST MON FEB 20 2012
A LINE OF SHOWERS MOVING THROUGH COU WILL MOVE NEWD THROUGH THE
REST OF THE TAF SITES DURING THE OVERNIGHT HOURS. THIS ACTIVITY
WAS ASSOCIATED WITH A SFC LOW OVER EXTREME NWRN MO AND A TRAILING
CDFNT S OF THE LOW. THESE SHOWERS SHOULD ONLY LAST A COUPLE OF
HOURS AS THEY MOVE QUICKLY THROUGH THE AREA. CLOUD CEILINGS HAVE
DROPPED INTO THE MVFR CATAGORY IN COU WITH THE RAIN AND SHOULD
ALSO DROP TO AROUND 2500 FT IN THE REST OF THE TAF SITES AS THE
RAIN MOVES IN. THE CIGS SHOULD ALSO LOWER LATE TGT/EARLY TUE MRNG
AFTER FROPA...ALTHOUGH PROBABLY NOT AS LOW AS THE NAM MOS CIG
HEIGHT GUIDANCE. GUSTY SLY SFC WINDS CAN BE EXPECTED ESPECIALLY
WITH THE SHOWER ACTIVITY...WITH THE WIND GRADUALLY VEERING AROUND
TO A SWLY DIRECTION AFTER FROPA AND A WLY DIRECTION TUE MRNG. THE
MVFR CIGS SHOULD SCATTER OUT IN COU EARLY TUE MRNG AND IN THE REST
OF THE TAF SITES LATE TUE MRNG. THE RELATIVELY STRONG AND GUSTY
WLY SFC WINDS WILL DIMINISH TUE EVNG AND BACK AROUND TO A SWLY
DIRECTION.
SPECIFICS FOR KSTL...A LINE OF SHOWERS WILL MOVE THROUGH STL FROM
06-09Z TUE WITH CLOUD CEILINGS LOWERING INTO THE MVFR CATAGORY
AND SELY SFC WINDS BECOMING SLY AND GUSTING UP TO AROUND 30 KTS
WITH THE SHOWERS. THE CEILING MAY RISE BRIEFLY AFTER MOST OF THE
SHOWERS MOVE THROUGH...BUT THEN DROP BACK DOWN TO THE MVFR
CATAGORY AFTER FROPA. THE SFC WIND WILL CONTINUE TO VEER AROUND TO
A SWLY DIRECTION LATE TGT AFTER FROPA...AND THEN A WLY DIRECTION
TUE MRNG. THE MVFR CIG SHOULD SCATTER OUT BY LATE TUE MRNG. THE
STRONG AND GUSTY WLY SFC WIND WILL DIMINISH TUE NGT AND BACK
AROUND TO A SWLY DIRECTION.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1122 PM CST MON FEB 20 2012
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
LOW CLOUDS CONTINUED TO CLEAR EASTWARD AND SHOULD WORK EAST OF
OMAHA BY 10-11Z. A PERIOD OF GUSTY NORTHWEST WINDS ARE EXPECTED
BEHIND COLD FRONT BUT THEY SHOULD RELAX AND BACK A LITTLE LATER
TONIGHT TO MORE WESTERLY BEFORE POSSIBLY INCREASING A BIT WITH
MIXING ON TUESDAY. A WEAK DISTURBANCE WILL SPREAD MID/HIGH CLOUDS
ACROSS AREA TUESDAY...ESPECIALLY BY EVENING.
CHERMOK
&&
PREV DISCUSSION... /ISSUED 340 PM CST MON FEB 20 2012/
SHORT TERM...TONIGHT THROUGH THURSDAY.
THE MAIN CONCERNS IN THE SHORT TERM WILL BE THE COVERAGE OF THE
PRECIPITATION THAT RE-DEVELOPS AND PRECIP
TYPE...CONVECTION...RAIN/SNOW MIX.
THE 12Z UPPER AIR CHARTS SHOWED A 110+KT JET OVER NEW MEXICO
ROUNDING THE BASE OF THE TROF. THE H5 LOW WAS OVER NORTHEAST
COLORADO WITH 130M HEIGHT FALLS AT DENVER. THE H7 LOW WAS NEAR KLBF
WITH H7-H5 LAPSE RATES OF 7.5 DEG C/KM AHEAD OF THE H7 LOW. THE H85
LOW WAS NEARLY VERTICALLY STACKED BTWN RAPID CITY AND NORTH PLATTE.
BOTH DDC AND OMA REPORTED 50KT H85 WINDS. AT MIDDAY...THE SURFACE
MAP HAD SFC LOW PRESSURE NEAR LEXINGTON AND PER THE VISIBLE
STLT...THERE WAS NOTICEABLE CLEARING JUST AHEAD OF THE SFC LOW. SFC
TEMPERATURES RANGED FROM THE MID 30S IN THE NORTH TO THE MID AND
UPPER 40S TOWARD FAIRBURY AND FALLS CITY. THE WSR-88D RADAR MOSAIC
LOOP FROM THIS MORNING AND METARS SHOWED THAT TEMPERATURES WARMED
ABOVE FREEZING...HOWEVER SNOW AND SLEET DID MOVE ACROSS THE NORFOLK
AND WAYNE AREAS WITH VSBYS DOWN TO 2SM. 6HR PRECIPITATION
AMOUNTS THROUGH 18Z WERE LIGHT...GENERALLY .15 OR LESS. THERE WERE
A FEW LIGHTNING STROKES NEAR BVN/OLU/OFK. BY 19Z...THE BULK OF THE
PRECIPITATION HAD SHIFTED NORTH AND EAST OUT OF EASTERN
NEBRASKA...WITH THE NORTH TO SOUTH BAND ACROSS WRN IOWA. OUTSIDE OF
OUR AREA...WEST OF THE SURFACE LOW IN WESTERN NEBRASKA...SNOW WAS
FALLING...MODERATE TO HEAVY AT TIMES FROM VALENTINE TO IMPERIAL.
AT 21Z...A NARROW LINE OF CONVECTION WAS DEVELOPING ACROSS CENTRAL
KANSAS...WITH A FEW WARNINGS BEING ISSUED. THIS CONVECTION IS
PROGRESSING NORTH AND EAST. AT 00Z THE THETA-E AXIS IS PROGGED TO
STRETCH FROM ERN NEB INTO ERN KANSAS AND ZERO OR LOWER BEST
LIFTED INDEX VALUES ARE OVER THE NEB/KS BORDER AHEAD OF THE SFC
LOW. THE LATEST HRRR TENDS TO TAKE THE BETTER CONVECTION SOUTH OF
THE FORECAST AREA...HOWEVER...DID INCLUDE THUNDERSTORM MENTION
OVER THE SOUTHEAST NEB WITH DRIZZLE OR LIGHT RAIN FARTHER
NORTH...AND A MIX OF RAIN/SNOW MOVING EAST DURING THE EVENING.
THE RUC AND 18Z NAM SHOW THE BAND OF SNOW WEAKENING AS IT MOVES
INTO THE FORECAST AREA...HOWEVER THERE MAY BE ENOUGH
OMEGA/FRONTOGENESIS/DEPTH OF COLD AIR TO SWITCH IT OVER TO LIGHT
SNOW. DID INCLUDE SOME MINOR SNOW AMOUNTS IN PARTS OF ECNTRL/NE
NEB TO ACCOUNT FOR THIS. TREND AFTER 06Z IS FOR THE SYSTEM TO BE
MOVING OUT...WITH WESTERLY FLOW FOR TUESDAY.
LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT...NORTHWEST FLOW ALOFT
WILL BRING MODERATE TEMPERATURES AND VARIABLE CLOUDS. THE MODELS
HAVE SOME DIFFERENCES ON THE CHC FOR PRECIPITATION DURING THIS
PERIOD. FOR NOW INCLUDED SOME SPRINKLES WEDNESDAY AND WITH THE
COLDER AIR WEDNESDAY NIGHT AND THURSDAY...A RAIN SNOW MIX IN THE
NORTH.
ZAPOTOCNY
LONG TERM...THURSDAY NIGHT THROUGH MONDAY.THE LONG TERM PERIOD
WILL BEGIN WITH AN UPPER TROUGH OVER THE GREAT LAKES AND THE
EASTERN NORTHERN PLAINS. A SHORTWAVE SHOULD BE EXITING OUR AREA
THURSDAY NIGHT SO WILL MAINTAIN A DRY FORECAST THEN. ANOTHER
SHORTWAVE LOOKS TO DROP THROUGH THE NORTHWEST FLOW ON BACK SIDE OF
UPPER TROUGH ON FRIDAY...WITH MODELS SHOWING VARYING DEGREES OF
INTENSITY AND LOCATION. GFS IS THE STRONGEST AND FARTHEST
WEST...WHICH WOULD BRING A CHANCE FOR LIGHT SNOW TO OUR
AREA...WHILE ECMWF/CANADIAN TRACK SHORTWAVE TO OUR EAST. WILL STAY
WITH MAJORITY OF MODEL SOLUTIONS WHICH MATCH OUR CURRENT DRY
FORECAST. HOWEVER ALL SOLUTIONS SUGGEST A RATHER CHILLY DAY FRIDAY
AS AT LEAST MODERATE COLD ADVECTION SHOULD KEEP HIGHS IN THE 30S.
A WARMING TREND STILL LOOKS ON TAP FOR THE WEEKEND AS UPPER FLOW
BECOMES MORE ZONAL IN WAKE OF EXITING UPPER TROUGH AND AHEAD OF
LOWERING HEIGHTS ALONG THE WEST COAST. AGAIN TODAY MODELS HAVE
DIFFERING OPINIONS ON TIMING AND EXTENT OF WARMING BASED ON
DIFFERING UPPER FLOW SOLUTIONS. FOR THE MOST PART...ALL MODELS SHOW
LOWERING HEIGHTS IN THE WEST...BUT SOME ARE HINTING AT A SIGNIFICANT
PIECE OF ENERGY MOVING FROM THE ROCKIES ACROSS THE PLAINS ON SUNDAY.
GFS IS THE MOST BULLISH IN THIS REGARD...AND HAS NOT WAVERED FROM
RUN TO RUN. HOWEVER...GFS ENSEMBLE MEMBERS ARE SPLIT...WITH A
PLURALITY LEANING TOWARD A 00Z ECMWF SOLUTION KEEPING MORE ENERGY
DROPPING INTO THE SOUTHWEST STATES AND MAINTAINING ZONAL OR
SOUTHWEST FLOW ALOFT IN THE PLAINS THROUGH SUNDAY. THE NEW 12Z ECMWF
MAINTAINS THIS PHILOSOPHY...SO HAVE SIDED WITH THIS THOUGHT FOR THE
WEEKEND.
USING ECMWF...HIGHS SATURDAY SHOULD REBOUND BACK INTO THE
40S BUT SUNDAY IS STILL IN QUESTION. BAROCLINIC ZONE LOOKS TO SET UP
NORTH TO SOUTH ACROSS OUR CWA WITH THE 0C 850 LINE NEAR INTERSTATE
80. STRONG ISENTROPIC UPGLIDE WILL COMMENCE SUNDAY AFTERNOON UNDER
COUPLED JET STRUCTURE...SUGGESTING LIFT OVER BAROCLINIC ZONE COULD
LEAD TO PRECIPITATION IN OUR NORTH. THICKNESSES SUPPORT SNOW
THERE...BUT WARM LOW LEVEL TEMPS COULD CHANGE THAT TO RAIN. SO A MIX
OF PRECIP WILL BE ADDED TO FORECAST SUNDAY. CLOUDS AND
PRECIPITATION CHANCES WILL LIKELY LIMIT HIGHS TO THE 30S IN OUR
NORTH. THIS TREND CONTINUES INTO MONDAY AS SURFACE LOW TRACKS TO OUR
SOUTH...MAINTAINING BAROCLINICITY ACROSS OUR AREA WITH A NORTHWEST
TO SOUTHEAST ORIENTATION. TRACK OF LOW PUTS OUR SOUTHEAST CWA IN
FAVORABLE AREA FOR RAIN THEN...WITH HIGHS RANGING FROM THE 20S OR
LOWER 30S NORTHWEST TO THE UPPER 30S SOUTHEAST. THERE IS A LOT OF
ROOM FOR ERROR SUNDAY AND MONDAY GIVEN PROXIMITY OF BAROCLINIC
ZONE...SO RELATIVELY LOW CONFIDENCE FORECAST AT THIS TIME.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1132 PM CST MON FEB 20 2012
.DISCUSSION...UPDATED FOR 6Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...TRANSITIONG TO IFR/LIFR CIGS/VSBYS TONIGHT ALL
TERMINALS WITH CONDITIONS SLOWLY IMPROVING TO MVFR LEVELS
TUESDAY AFTN THEN BACK TO IFR LATE IN THE FCST PERIOD. STRATUS
AND FOG XPCTD TO DVLP TONIGHT WITH CIGS LOWERING VSBYS REDDUCING
TO LIFR LEVELS OCCURRING FIRST AT KVCT/KALI THEN KCRP AND LAST AT
KLRD. CONDITIONS SHOULD BE SLOW TO IMPROVE TUES MRNG BUT SHOULD
EVENTUALLY MAKE IT TO MVFR LEVELS BY AFTN. CIGS AND VSBYS THEN TO
QUICKLY LOWER AGAIN BY LATE IN THE TAF FCST PERIOD TO IFR LEVELS
DUE TO LOW LEVEL MOISTURE INFLUX. LIGHT WINDS TONIGHT TO BECOME
LIGHT TO MODERATE FROM THE SE ON TUES.
&&
.PREV DISCUSSION... /ISSUED 943 PM CST MON FEB 20 2012/
DISCUSSION...MINOR CHANGES WERE MADE TO THE ONGOING FORECAST.
ALTERED CLOUD COVER TO REFLECT SLOWER DEVELOPMENT OF STRATUS AND
FOG FOR TONIGHT AND INCREASED DEWPOINTS SLIGHTLY. MSAS AND
SURFACE ANALYSES THIS EVENING HAVE A COLD FRONT DRAPED ACROSS
CENTRAL TX WITH THIS FRONT PROG TO DRIFT INTO AT LEAST NORTHERN
PORTIONS OF S TX BY LATE TONIGHT. AHEAD OF THE FRONT A GRADUAL
INFLUX OF LOW LEVEL MOISTURE WILL CONTINUE AND WITH LIGHT SURFACE
WINDS AND THE INCREASING MOISTURE AREAS OF FOG MAY DEVELOP.
STATISTICAL GUIDANCE CONTINUES TO INDICATE NEARLY WIDESPREAD FOG
TONIGHT WHILE RAW MODEL OUTPUT IS LESS PESSIMISTIC. NAM WANTS TO
DEVELOP FOG ACROSS MANY INLAND LOCATIONS SHORTLY AFTER MIDNIGHT
BUT DISSIPATES MUCH OF IT SHORTLY BEFORE SUNRISE. LATEST RUC HAS
AREAS OF FOG DEVELOPING AND DISSIPATING ON AND OFF THROUGH THE
NIGHT. DENSE CIRRUS PERSISTS ACROSS S TX TONIGHT AS UPPER JET
REMAINS OVERHEAD AND UNCERTAINTY REMAINS AS TO HOW MUCH OF AN
INFLUENCE THAT WILL HAVE ON FOG DEVELOPMENT AS WELL. FOR NOW WILL
MAINTAIN AREAS OF FOG IN THE FORECAST. UPDATED PRODUCTS TO BE
SENT SOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 57 74 61 76 64 / 10 10 20 20 30
VICTORIA 55 73 57 76 60 / 10 10 10 10 30
LAREDO 58 74 64 82 65 / 10 10 10 10 30
ALICE 56 75 60 79 63 / 10 10 20 10 30
ROCKPORT 58 73 60 67 64 / 10 10 20 20 30
COTULLA 51 73 58 80 63 / 10 10 10 10 30
KINGSVILLE 55 74 60 77 64 / 10 10 20 20 30
NAVY CORPUS 60 72 61 69 64 / 10 10 20 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AVIATION...HART/79
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1126 PM CST MON FEB 20 2012
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...PLUME OF PACIFIC MOISTURE STREAMING OVERHEAD AS THICK
CIRRUS DECK WILL CONTINUE THROUGH THE OVERNIGHT HOURS. THIS WILL
HOLD TEMPS UP A COUPLE DEGREES AND SHOULD KEEP FOG FROM BECOMING
DENSE. HAVE PARED BACK FOG WORDING IN TAFS TO TEMPOS AND NO
THICKER THAN 1SM AROUND DAWN. CIGS WILL GRADUALLY LIFT THROUGH THE
MORNING AND SHOULD BE AROUND 3000 FEET JUST AFTER NOON.
&&
.PREV DISCUSSION... /ISSUED 856 PM CST MON FEB 20 2012/
DISCUSSION...GUIDANCE IS BULLISH ON LOW CEILINGS AND PATCHY TO
AREAS OF FOG TONIGHT THROUGH MID TUESDAY MORNING. SCT TO BKN HIGH
CLOUDS NOT PLAYING A MAJOR ROLE. RUC IS SHOWING AMPLE LOW LEVEL
MOISTURE...COUPLED WITH CONTINUING LIGHT ONSHORE WINDS. WIDESPREAD
DENSE FOG IS NOT EXPECTED...BUT LOCAL AREAS OF DENSE FOG WILL BE
POSSIBLE...ESPECIALLY IN THE MID AND UPPER VALLEY. SAT IMAGERY
ALSO SUGGESTS LOW CLOUDS IN THE WEST GULF MOVING NORTHWEST TOWARD
THE REGION. BEEFED UP THE WORDING IN THE FORECAST AND REISSUED TO
REFLECT THE DEVELOPING SITUATION.
PREV DISCUSSION... /ISSUED 523 PM CST MON FEB 20 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...FOG AND LOWER CEILINGS LOOK PRETTY CERTAIN TONIGHT
WITH WINDS BECOMING LIGHT AND INCREASING LOW LEVEL MOISTURE. SCT
TO BKN HIGH CLOUDS WILL NOT BE ENOUGH TO PREVENT TEMPERATURES FROM
DECREASING TO THE CORRESPONDING DEW POINTS TONIGHT. LOCALLY DENSE
FOG LOOKS LIKELY IN THE MID AND UPPER VALLEY...BUT IFR CONDITIONS
ARE DEFINITELY ON TAP FOR THE LOWER VALLEY...DEVELOPING AFTER
MIDNIGHT WITH WORSENING CONDITIONS THROUGH DAWN TO MID TUESDAY
MORNING. NOT READY TO POUNCE ON A DENSE FOG ADVISORY JUST YET...
BUT WILL PROBABLY BEEF UP THE FOG CHARACTERIZATION SOMEWHAT IN A
LOCAL FORECAST UPDATE. THE TAFS TAKE FOG INTO ACCOUNT NOW.
PREV DISCUSSION... /ISSUED 120 PM CST MON FEB 20 2012/
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...NORTHEAST FLOW ALOFT
WILL CONTINUE TO STREAM CIRRUS CLOUDS ACROSS THE RIO GRANDE VALLEY
AS MID LEVEL MOISTURE OVER THE PACIFIC IS BEING PUSH INTO THE
AREA. SURFACE SOUTHEAST FLOW WITH GUSTY WINDS WILL PREVAIL THROUGH
THE AFTERNOON. EXPECT WINDS TO BEGIN TO DECOUPLE AFTER SUNSET.
GOOD MOISTURE IN THE AREA AND LIGHT SOUTHEAST WINDS WILL PROVIDE
GOOD CONDITIONS FOR PATCHY FOG TO DEVELOP AFTER MIDNIGHT.
LOCATIONS FURTHER NORTH AND WEST WILL LIKELY SEE MORE DENSE FOG
THAN THE LOWER VALLEY TONIGHT. LOW TEMPERATURES WILL REMAIN IN THE
MID 60S ALONG THE COAST AND LOCATIONS CLOSE TO THE BORDER WITH THE
COOLER SPOTS IN THE NORTHERN COUNTIES. NO MUCH PRECIPITATION
EXPECTED UNTIL TUESDAY NIGHT INTO WEDNESDAY MORNING AS A WEAK
DISTURBANCE WITHIN THE UPPER LEVEL FLOW MOVES ACROSS THE AREA.
HIGH TEMPERATURES WILL WARM BACK REACHING CLOSE TO THE 80S.
ANOTHER ROUND OF WIDESPREAD FOG WILL LIKELY DEVELOP WEDNESDAY
AFTER MIDNIGHT. LIGHTER WINDS AND MORE MOISTURE IN THE AREA WILL
ENHANCE THE DEVELOPMENT OF FOG TO BE MORE WIDESPREAD ACROSS THE
FORECAST AREA.
LONG TERM /WEDNESDAY THROUGH SUNDAY/...NO SIGNIFICANT CHANGES WERE
MADE TO THE FORECAST IN THE LONG TERM. SCATTERED SHOWERS ARE EXPECTED
WEDNESDAY AND WEDNESDAY NIGHT DUE TO THE SLOW PROGRESSION OF A 500 MB
CLOSED LOW OVER THE NORTHWEST CORNER OF MEXICO. AS THE LOW FILLS AND
DRAGS A SHARP MID-LEVEL TROUGH THROUGH THE LONE STAR STATE...A WEAK
PACIFIC COLD FRONT WILL PASS THROUGH DEEP SOUTH TEXAS AND THE RIO
GRANDE VALLEY THURSDAY...WITH SCATTERED SHOWERS AND THUNDERSTORMS.
A MORE SIGNIFICANT COLD FRONT WILL PASS THROUGH OUR REGION THURSDAY
NIGHT...HOWEVER DRIER AIR ASSOCIATED WITH THE WAKE OF THE PACIFIC
COLD FRONT WILL PREVENT ANY PRECIPITATION FOR THAT TIME. PLEASANT
CONDITIONS ARE FORECAST FRIDAY THROUGH SUNDAY WITH DRY WEATHER DUE
TO A NEARLY ZONAL FLOW IN THE MIDDLE LAYERS OF THE ATMOSPHERE OVER
THE BRO CWFA FOR THAT PERIOD. NEAR TO ABOVE NORMAL TEMPERATURES
WEDNESDAY AND THURSDAY WILL BE COOLED TO NEAR NORMAL LEVELS FRIDAY
AND SATURDAY COURTESY OF THE COLD FRONTAL PASSAGE THURSDAY NIGHT...
WITH WARMING TEMPERATURES ANTICIPATED FOR SUNDAY DUE TO AN ONSHORE
FLOW.
MARINE...TONIGHT THROUGH TUESDAY NIGHT...SEAS AND WINDS CONDITIONS
WILL REMAIN FAIRLY GOOD ACROSS THE GULF WATERS THE REST OF TODAY
INTO TUESDAY NIGHT. SOUTHEAST WINDS WILL DECOUPLE THIS EVENING
BECOMING LIGHT OVER THE GULF WATERS TONIGHT. LIGHT ISOLATED
SHOWERS WILL LIKELY DEVELOP OVER THE OFFSHORE WATERS TUESDAY
AFTERNOON INTO THE EVENING AS A WEAK DISTURBANCE MOVES ACROSS THE
AREA.
WEDNESDAY THROUGH SUNDAY...FAVORABLE MARINE CONDITIONS WILL PERSIST
WEDNESDAY THROUGH THURSDAY EVENING...WITH LIGHT TO MODERATE WINDS
AND LOW TO MODERATE SEAS EXPECTED...AS HIGH PRESSURE INITIALLY
PREVAILS...WITH THE PASSAGE OF A WEAK COLD FRONT THURSDAY EVENING.
THE PASSAGE OF A MORE SIGNIFICANT COLD FRONT THURSDAY NIGHT WILL
RAPIDLY INCREASE WINDS AND BUILD SEAS IN ITS WAKE...AND A SMALL
CRAFT ADVISORY MAY BE NEEDED FOR ALL OR PORTIONS OF THE ADJACENT
COASTAL WATERS OF DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY
THURSDAY NIGHT THROUGH FRIDAY NIGHT. STRONG WINDS AND ROUGH SEAS
WILL PREVAIL FOR SATURDAY AND SUNDAY WITH HIGH PRESSURE OVER THE
GULF OF MEXICO INTERACTING WITH LOWER PRESSURE OVER NORTH TEXAS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
64
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
312 AM CST TUE FEB 21 2012
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
312 AM CST TUE FEB 21 2012
FORECAST CONCERNS FOCUS ON SNOW/RAIN TODAY...THEN ON ADDITIONAL
PRECIPITATION CHANCES THROUGH THE REST OF THE WEEK.
WATER VAPOR/IR SATELLITE IMAGERY EARLY THIS MORNING SHOWING COMPACT
MID-LEVEL CLOSED LOW OVER NORTHERN MO SLOWLY PHASING WITH A TROUGH
PUSHING INTO WESTERN MN. MOISTURE ADVECTION AND STRONG ISENTROPIC
LIFT AHEAD OF THESE FEATURES PRODUCED A SIGNIFICANT WING OF
LIGHT-MODERATE SNOW ACROSS THE FORECAST AREA OVERNIGHT WITH 1-1.5
INCHES REPORTED ALONG/WET OF THE MISSISSIPPI RIVER. CURRENT RADAR
MOSAIC AT 2 AM SHOWING THE MAIN WING OF LIGHT-MODERATE SNOW HAS
WEAKENED OVER THE LAST COUPLE OF HOURS AND HAS PUSHED NORTHEAST OF
THE I-94 CORRIDOR. MEANWHILE...IR SATELLITE/RADAR TRENDS SHOWING SOME
REGENERATION OF SNOW/RAIN ACTIVITY WEST OF THE MISSISSIPPI ALONG THE
I-35 CORRIDOR...AND WAS MOVING EAST. THIS WAS IN RESPONSE TO
STRETCHING DEFORMATION/INCREASING MID-LEVEL FRONTOGENESIS AREA
BETWEEN THE NORTHERN MID-LEVEL TROUGH AND THE CLOSED LOW LIFTING
NORTHEAST OUT OF NORTHERN MO.
21.00Z NCEP MODELS AND THE 21.03Z SREF SHOWING PRETTY DECENT
AGREEMENT THROUGH WEDNESDAY...BUT THEN START DIVERGING WED N/THU WITH
INCOMING WAVE IN NORTHWEST FLOW ALOFT. HAVE LEANED TOWARD A BLEND
APPROACH FOR NOW.
FOR TODAY...WILL BE KEEPING A CLOSE EYE ON THAT DEFORMATION BAND
PRECIPITATION MOVING EAST THROUGH THE AREA. MODELS SHOWING THE
CLOSED LOW OPENING/PHASING WITH THE NORTHERN TROUGH WHICH ROTATES
INTO EASTERN WI BY THIS AFTERNOON. AS SUCH...WILL START OFF THIS
MORNING WITH CATEGORICAL -SN ALONG/EAST OF THE MISSISSIPPI RIVER
THROUGH 9 AM...THEN LIFTING THIS ALONG/NORTH OF I-94 AFTER 9 AM.
LOOKS LIKE PERHAPS UP TO ANOTHER HALF INCH OF SNOWFALL WILL BE
POSSIBLE ALONG AND EAST OF THE MISSISSIPPI RIVER THROUGH THIS
MORNING BEFORE MIXING WITH RAIN AS TEMPERATURES WARM. WILL HAVE TO
CONTINUE A CLOSE WATCH ON THESE PRECIPITATION TRENDS AND MAKE
ADJUSTMENTS AS NECESSARY THROUGH THIS MORNING.OTHERWISE...A FAIRLY
DECENT PRESSURE GRADIENT WILL EXIST ACROSS THE AREA TODAY ALONG WITH
MIXING TO AROUND 875MB. THIS WILL PRODUCE BREEZY WEST WINDS THROUGH
THE DAY WITH GUST AROUND 30 MPH ACROSS THE WIND PRONE AREAS OF
NORTHEAST IA/SOUTHEAST MN AND THE BLUFF TOPS OF SOUTHWEST WI.
TEMPERATURES TODAY EXPECTED TO TOP OFF IN THE MID 30S TO LOWER
40S.
LINGERING CYCLONIC FLOW WILL CONTINUE TO PRODUCE A CHANCE OF -SN
ACROSS CLARK/TAYLOR COUNTIES TONIGHT. NOT EXPECTING MUCH IN THE WAY
OF ACCUMULATION...PERHAPS A FEW TENTHS OF AN INCH. ACROSS THE REST
OF THE AREA...SOME CLEARING EXPECTED AS A WEAK RIDGE OF HIGH
PRESSURE MOVES INTO THE UPPER MISSISSIPPI RIVER REGION FROM THE
NORTHERN PLAINS.
REST OF THE PERIOD WILL SEE NORTHWEST FLOW AND A SLOWLY DEEPENING
TROUGH ACROSS THE CENTRAL CONUS/UPPER MISSISSIPPI RIVER REGION.
SURFACE CYCLOGENESIS IN RESPONSE TO DEEPENING TROUGH ALOFT MOVES
FROM THE NORTHERN PLAINS TOWARD THE REGION WEDNESDAY
AFTERNOON/NIGHT. NAM SHOWING FAIRLY STRONG LIFT ON THE 285K SURFACE
AHEAD OF THE WAVE GOING INTO WEDNESDAY NIGHT. BASED ON THIS
SIGNAL...BUMPED PRECIPITATION CHANCES UP TO 50 PERCENT WEDNESDAY
NIGHT. PRECIPITATION EXPECTED TO BE A RAIN/SNOW MIX DURING THE DAY
WEDNESDAY AS TEMPERATURES WARM INTO THE MID 30S TO LOWER 40S...THEN
TRANSITION TO ALL SNOW WEDNESDAY NIGHT AS THE COLUMN COOLS. COULD
PICK UP SOME LIGHT SNOW ACCUMULATIONS AS WELL...PERHAPS A HALF TO
ONE INCH. RAIN/SNOW CHANCE WILL CONTINUE THURSDAY/THURSDAY NIGHT AS
THE SURFACE LOW PRESSURE MOVES OUT OF WI INTO THE GREAT LAKES
REGION...BUT INVERTED SURFACE TROUGH/MID-LEVEL TROUGH LINGERS OVER
THE AREA. AGAIN...PRECIPITATION WILL LIKELY BE A RAIN/SNOW MIX
DURING THE DAY THURSDAY AS SURFACE TEMPERATURES WARM INTO THE
MIDDLE/UPPER 30S...THEN TRANSITION BACK TO ALL SNOW THURSDAY NIGHT
WITH COOLING.
.LONG TERM...FRIDAY THROUGH MONDAY
312 AM CST TUE FEB 21 2012
BOTH THE 21.00Z GFS AND ECMWF SHOW COOLER CYCLONIC FLOW LINGERING
ACROSS THE AREA THROUGH FRIDAY FOR A CHANCE OF SNOW. LOOKS LIKE
SATURDAY WILL BE DRY AS A FAIRLY STRONG RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION. GFS AND ECMWF THEN DRIFT OUT OF PHASE WITH
EACH OTHER THROUGH THE REMAINDER OF THE PERIOD..LENDING TO DECREASED
FORECAST CONFIDENCE IN THE SUNDAY/MONDAY PERIOD. THE GFS WANTS TO
PRODUCE STRONG CYCLOGENESIS OVER THE PLAINS SATURDAY NIGHT...THEN
TAKES THE DEEPENING LOW RAPIDLY NORTHEAST TOWARD THE SOUTHERN WI BY
SUNDAY AFTERNOON....AND THEN INTO THE GREAT LAKES REGION ON MONDAY.
THIS WOULD SUGGEST THE POTENTIAL FOR HEAVY SNOW FOR THE AREA SUNDAY.
THE ECMWF ON THE OTHER HAND DIGS THE MID-LEVEL TROUGH ACROSS THE
INTERMOUNTAIN WEST...EJECTING A DEEP SURFACE LOW INTO MN SUNDAY
NIGHT/MONDAY. THIS WOULD SUGGEST WARMER/RAIN SCENARIO FOR THE AREA.
SO...TIMING AND PRECIPITATION TYPE REMAINS HARD TO PINPOINT. AS A
RESULT...WILL CONTINUE WITH MODEL CONSENSUS APPROACH FOR NOW.
&&
.AVIATION...THROUGH 06Z WEDNESDAY
1136 PM CST MON FEB 20 2012
THE BAND OF SNOW IS MOVING QUICKLY ACROSS THE FORECAST AREA THIS
EVENING AND IS SMALLER IN AREAL COVERAGE THAT PREVIOUSLY EXPECTED.
GROUND TRUTH REPORTS INDICATE THE SNOW HAS TAPERED OFF TO JUST
FLURRIES AT KAUM AND BASED ON RADAR...EXPECT THIS TO HAPPEN
SHORTLY AS KRST AS WELL. THE SNOW SHOULD CONTINUE FOR A COUPLE
MORE HOURS AT KLSE BEFORE STARTING TO DIMINISH AS WELL. THE SNOW
MAY NOT COMPLETELY END AT KLSE UNTIL AFTER 12Z THOUGH AS THE UPPER
LEVEL LOW OVER NORTHWEST MISSOURI LIFTS TOWARD NORTHERN ILLINOIS.
BOTH THE 21.00Z NAM AND 21.03Z RUC SHOW THE LIGHT SNOW CONTINUING
ALONG THE SURFACE TROUGH AS THE UPPER LEVEL LOW LIFTS OUT AND THE
SURFACE TROUGH IS NOT EXPECTED TO MOVE EAST OF THE MISSISSIPPI
RIVER UNTIL ABOUT 12Z. CONFIDENCE IN THE SCENARIO IS NOT HIGH
BASED ON DOWNSTREAM RADARS AND WOULD NOT BE SURPRISED IF THE SNOW
TOTALLY ENDS AT KLSE WELL BEFORE 12Z. THE WIND WILL COME AROUND TO
THE WEST BEHIND THE PASSAGE OF THE SURFACE TROUGH AND WITH ENOUGH
MIXING...EXPECT THE VISIBILITY TO IMPROVE TO VFR ONCE THE SNOW
ENDS. ENOUGH MIXING EXPECTED TO OCCUR TUESDAY AFTERNOON FOR GUSTS
TO AROUND 25 KNOTS AT BOTH SITES. THE NAM SUGGESTS LOW LEVEL
MOISTURE WILL REMAIN TRAPPED UNDERNEATH THE LOW LEVEL INVERSION
AND KEEP CEILINGS IN THE MVFR RANGE THROUGH 06Z WEDNESDAY. THE
21.00Z GFS IS NOT AS PESSIMISTIC AND DEVELOPS VFR CEILINGS TUESDAY
AFTERNOON. UPSTREAM CONDITIONS OVER WESTERN MINNESOTA LENDS MORE
SUPPORT TO THE NAM SO HAVE STAYED WITH MVFR CEILINGS THROUGH THE
PERIOD ONCE THE SNOW ENDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
312 AM CST TUE FEB 21 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... DAS
LONG TERM.... DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1136 PM CST MON FEB 20 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
250 PM CST MON FEB 20 2012
FORECAST CONCERNS FOCUS ON THE SNOW FOR TONIGHT...THEN ADDITIONAL
CHANCES THROUGH THE REST OF THE WEEK.
LATEST WATERVAPOR SATELLITE IMAGERY PAINTS A SHORTWAVE DIGGING
ACROSS THE SOUTHERN PLAINS WHILE 88-D RADAR RETURNS DEPICTED A
BROAD...ELONGATED REGION OF PCPN RUNNING ACROSS THE WESTERN PORTIONS
OF MN/IA.
20.12Z GFS AND NAM IN GOOD AGREEMENT WILL DRIVING THIS SHORTWAVE
OVER NORTHERN ILL BY 12Z TUE...LIFTING IT OVER THE EASTERN GREAT
LAKES LATER IN THE DAY AS ANOTHER PIECE OF UPPER LEVEL ENERGY DROPS
ACROSS NORTHERN PORTIONS OF THE REGION. THE STRONGEST AND DEEPEST QG
CONVERGENCE CONTINUES TO BE CO-LOCATED WITH THE UPPER LEVEL
ENERGY...JUST SOUTH OF THE FORECAST AREA. SOME 2-D FRONTOGENETIC
FORCING INDICATED ALONG A SFC BOUNDARY THAT EXTENDING NORTH OF SFC
LOW ASSOCIATED WITH THE MAIN SHORTWAVE...TO ANOTHER LOW LOCATED
WITH THE NORTHERN BIT OF ENERGY. GOOD ISENTROPIC UPGLIDE ON THE
275-295 K SFC OUT AHEAD OF THE BOUNDARY. 40 KT 850 MB LOW LEVEL JET
WILL NOSE INTO THE AREA TONIGHT...HELPING PUSH PWS UP TO AROUND 1/2
INCH...OVER 150 PERCENT OF NORMAL. SO...LOOK FOR THE BANDS OF PCPN
TO THE WEST TO TRANSITION ACROSS THE REGION TONIGHT...GRADUALLY
EXITING NORTHEAST ON TUE.
AS FOR WHAT WILL FALL...BUFKIT SOUNDINGS SUGGEST PERHAPS A BRIEF MIX
OF RAIN/SNOW INITIALLY TO THE WEST...BUT WITH SATURATION FROM
TOP DOWN AND TIMING OF THE PCPN...ANY RAINFALL WOULD QUICKLY GIVE
WAY TO ALL SNOW. SNOW CONTINUES TONIGHT INTO TUESDAY MORNING. ON THE
BACKSIDE OF THE EXITING SYSTEM SOUNDINGS AND WEST-EAST RUNNING
X-SECTIONS SHOW A SHALLOWING OUT OF THE MOISTURE...WHICH COULD
REMOVE ICE FROM THE CLOUDS. IF THERE IS LIFT THROUGH THESE CLOUDS
FREEZING DRIZZLE/DRIZZLE COULD OCCUR FOR A COUPLE HOURS. WILL LEAVE
THIS POTENTIAL OUT OF THE FORECAST FOR NOW...BUT THE POTENTIAL IS
THERE...AND TRENDS WILL HAVE TO BE MONITORED AND ADJUSTMENTS MADE TO
THE FORECAST IF THESE CHANCES INCREASE.
AS FOR HOW MUCH SNOW WILL FALL...BUFKIT SOUNDINGS STILL SHOW A
STRONG AMOUNT OF OMEGA THROUGH THE DENDRITIC GROWTH ZONE...BUT THIS
REGION REMAINS FAIRLY SMALL. IT ALSO REMAINS FAIRLY WARM...ABOVE -5
C FOR THE BOTTOM 6 KFT...SUGGESTING A WET/HEAVY SNOW...THUS LEANING
TOWARD LOWER SNOW RATIOS. WILL HOVER IN THE 10-14 TO 1 RATIOS FOR
NOW...WHICH IS HOW COBB OUTPUT SUGGESTS MOST OF THE SNOW WILL FALL.
1 TO 3 INCHES STILL LOOKS GOOD FOR TOTALS...WITH THE HIGHER AMOUNTS
WEST OF THE MISSISSIPPI RIVER. ISOLATED 4 INCH AMOUNTS CAN/T BE
RULED OUT. WILL NOT AN ISSUE AND ADVISORY AT THIS TIME...BUT IF
THOSE 4 INCH AMOUNTS BECOME WIDESPREAD...AN ADVISORY WILL BE NEEDED.
ON WED NIGHT/THU...BOTH THE GFS AND NAM WANT TO BRING A SHORTWAVE
TROUGH ACROSS NORTHERN PORTION OF THE REGION...WITH ANOTHER STRONGER
PIECE OF ENERGY JUST SOUTH OF THAT...SPINNING ACROSS SOUTHERN MN/IA.
THE SOUTHERN SHORTWAVE WILL HAVE A BETTER SHOT AT PRODUCING
PCPN...AND BOTH MODELS DO LAY DOWN A STRIPE OF QPF. THERE IS SOME
VARIANCE IN TIMING AND POSITIONING...BUT THE FORECAST AREA WOULD BE
AFFECTED. TIMING IS IMPORTANT AS TEMPS SHOULD CLIMB ABOVE FREEZING
THU...LEADING TO RAIN OR A RAIN/SNOW MIX. AT THIS TIME...ABOUT 1/2
TO 1 INCH OF SNOW APPEARS POSSIBLE.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
250 PM CST MON FEB 20 2012
UPPER LEVEL FLOW LOOKS A BIT MORE ACTIVE COMPARED TO RECENT WEEKS
WITH BITS OF SHORTWAVE ENERGY SPINNING ACROSS THE REGION.
HOWEVER...GFS AND ECMWF APPEAR OUT OF PHASE WITH EACH OTHER AT
TIMES...KEEPING FORECAST CONFIDENCE LOW ON TIMING OF ANY OF THESE
POTENTIAL PCPN MAKERS. ONE THING THEY DO AGREE ON IS THE POTENTIAL
FOR SOME LIGHT SNOW THU NIGHT/FRI...POST AN EXITING SHORTWAVE
TROUGH...ASSOCIATED WITH AN INVERTED SFC TROUGH AND CYCLONIC FLOW A
LOFT. SUN-MON ALSO LOOKS LIKE PCPN WILL BE LIKELY...BUT WHAT...HOW
MUCH AND WHERE IS DIFFICULT TO PINPOINT. WILL LEAN HEAVILY ON THE
CONSENSUS SOLUTION FOR NOW.
&&
.AVIATION...THROUGH 06Z WEDNESDAY
1136 PM CST MON FEB 20 2012
THE BAND OF SNOW IS MOVING QUICKLY ACROSS THE FORECAST AREA THIS
EVENING AND IS SMALLER IN AREAL COVERAGE THAT PREVIOUSLY EXPECTED.
GROUND TRUTH REPORTS INDICATE THE SNOW HAS TAPERED OFF TO JUST
FLURRIES AT KAUM AND BASED ON RADAR...EXPECT THIS TO HAPPEN
SHORTLY AS KRST AS WELL. THE SNOW SHOULD CONTINUE FOR A COUPLE
MORE HOURS AT KLSE BEFORE STARTING TO DIMINISH AS WELL. THE SNOW
MAY NOT COMPLETELY END AT KLSE UNTIL AFTER 12Z THOUGH AS THE UPPER
LEVEL LOW OVER NORTHWEST MISSOURI LIFTS TOWARD NORTHERN ILLINOIS.
BOTH THE 21.00Z NAM AND 21.03Z RUC SHOW THE LIGHT SNOW CONTINUING
ALONG THE SURFACE TROUGH AS THE UPPER LEVEL LOW LIFTS OUT AND THE
SURFACE TROUGH IS NOT EXPECTED TO MOVE EAST OF THE MISSISSIPPI
RIVER UNTIL ABOUT 12Z. CONFIDENCE IN THE SCENARIO IS NOT HIGH
BASED ON DOWNSTREAM RADARS AND WOULD NOT BE SURPRISED IF THE SNOW
TOTALLY ENDS AT KLSE WELL BEFORE 12Z. THE WIND WILL COME AROUND TO
THE WEST BEHIND THE PASSAGE OF THE SURFACE TROUGH AND WITH ENOUGH
MIXING...EXPECT THE VISIBILITY TO IMPROVE TO VFR ONCE THE SNOW
ENDS. ENOUGH MIXING EXPECTED TO OCCUR TUESDAY AFTERNOON FOR GUSTS
TO AROUND 25 KNOTS AT BOTH SITES. THE NAM SUGGESTS LOW LEVEL
MOISTURE WILL REMAIN TRAPPED UNDERNEATH THE LOW LEVEL INVERSION
AND KEEP CEILINGS IN THE MVFR RANGE THROUGH 06Z WEDNESDAY. THE
21.00Z GFS IS NOT AS PESSIMISTIC AND DEVELOPS VFR CEILINGS TUESDAY
AFTERNOON. UPSTREAM CONDITIONS OVER WESTERN MINNESOTA LENDS MORE
SUPPORT TO THE NAM SO HAVE STAYED WITH MVFR CEILINGS THROUGH THE
PERIOD ONCE THE SNOW ENDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
250 PM CST MON FEB 20 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM... RIECK
LONG TERM.... RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1030 PM CST MON FEB 20 2012
.UPDATE...
LITTLE DIFFERENCE IN NEW 00Z NAM. HRRR TRIES TO SPLIT THE AREAS OF
PRECIPITATION WITH ONE AREA JUST TO THE SOUTH OF THE ILLINOIS
BORDER...AND A SECOND BRUSHING THE FAR NORTHWEST SECTIONS TOWARD
MARQUETTE COUNTY. STILL SOME LIGHT QPF IN BETWEEN. DID NOT CHANGE
FORECAST WITH MOST AREAS GETTING AN INCH OR LESS. LOCALIZED 1.5
INCH AMOUNTS STILL POSSIBLE. OTHER PROBLEM IS SOME RAIN/SNOW MIX
POSSIBLE WITH THE ONSET OF PRECIPITATION DUE TO WARMER BOUNDARY
LAYER.
&&
.AVIATION/06Z TAFS/...
EXPECT A BAND OF PRECIPITATION TO LOWER CIGS/VSBYS TO IFR AS IT
PUSHES SLOWLY EAST DURING THE EARLY MORNING HOURS. A RAIN SNOW MIX
TO BEGIN THEN MAINLY SNOW. ACCUMULATIONS MAINLY AN INCH OR LESS.
IFR CIGS TO CONTINUE THROUGH THE MORNING THEN BECOME MVFR/VFR
TUESDAY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 331 PM CST MON FEB 20 2012/
VERY SHORT TERM...TONIGHT AND TUESDAY. CONFIDENCE...MEDIUM.
WATER VAPOR/RUC COMBO SHOWS MAIN CIRCULATION CENTER SPINNING ACROSS
THE CENTRAL PLAINS. THIS WAVE PROGGD TO TAKE ON A NEGATIVE TILT AND
HEAD INTO CENTRAL ILLINOIS BY 12Z. WARM ADVECTION AND MOIST
SOUTHERLY FLOW WILL CONTINUE OUT AHEAD OF THE 850 MILLIBAR TROUGH
AXIS. DRY AIR TO HAVE A HOLD ON THE AREA UNTIL AFTER 6Z WHEN
MOISTURE AND VERTICAL MOTION INCREASE INTO THE WESTERN CWA. A LOT OF
THE BETTER LOW LEVEL Q-VECTOR CONVERGENCE AND UPPER DIVERGENCE
COINCIDE ACROSS SRN WI AROUND 6Z...AND THEN SHIFT EAST AS THE NIGHT
WEARS ON. SO SOME OF THE BETTER FORCING PARAMETERS ARE OUTRACING THE
MOISTURE/PRECIP WITH THIS SYSTEM. THE 700-300 MILLIBAR Q-VOECTOR
CONVEREGNCE DOES SHOW BETTER FORCING FROM 6-14Z...WITH THE BETTER
LIFT IN SOUTHERN WI. THOUGH BULK OF BETTER Q-VECTOR ACTION SHOWING
UP TO OUR SOUTH AND SOUTHEAST. BUFKIT DOES SHOW GOOD SATURATION FROM
LATE TONIGHT THROUGH MID MORNING TUESDAY. BEST FORCING NOTED OUTSIDE
THE FAVORED DENDRIDIC GROWTH ZONE. WILL GO WITH AN INCH OR LESS FOR
TOTAL ACCUMS AS COMBO OF QPF WITH NAM/GFS RATIOS AND THICKNESS
TECHNIQUE SUGGEST. ONCE TROUGH SHIFTS EAST...DECENT WESTERLY WIND
SETS UP WITH GRADIENT TIGHTENING. BUFKIT SUGGESTS MIXING OF SOME
GUSTS OVER 20 TUESDAY AFTERNOON. TEMPS SHOULD REACH ALLBLEND LEVELS
IN THE LOW 40S.
SHORT TERM...TUESDAY NIGHT THROUGH THURSDAY NIGHT.
TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE MEDIUM.
PRECIPITATION ENDS BY TUESDAY EVENING WITH SUBSIDENCE AND DRYING.
STEEP LOW-LEVEL LAPSE RATES TUESDAY EVENING AS POCKET OF COLDER
DRIER AIR WORKS UNDER LOW. MOSTLY CLOUDY OVERNIGHT WITH SOME
MOISTURE CONVERGENCE ON THE LEADING EDGE OF THE COLD AIR...BUT NOT
ENOUGH FOR PRECIPITATION. MID UPPER 20S FOR LOWS.
DRY THROUGH WEDNESDAY MORNING...WITH A SLIGHT CHANCE OF RAIN IN THE
AFTERNOON WITH WARM AIR ADVECTION AHEAD OF NEXT SHORT WAVE. 925MB
TEMPERATURES SUPPORT HIGHS IN THE UPPER 30S TO AROUND 40 NORTH...AND
LOWER TO MID 40S SOUTH.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE LOW TO
MEDIUM.
TIMING...STRUCTURE AND STRENGTH OF SHORT WAVES AND ASSOCIATED
SURFACE FEATURES LEAD TO UNCERTAINTY WITH LOCATION AND AMOUNTS OF
ANY PRECIPITATION THIS PERIOD. WILL TRY TO HIGHLIGHT MORE/LESS
PROBABLE PRECIPITATION PERIODS WITH HIGHER/LOWER CONSENSUS
POPS...BUT WITH UNCERTAINTY WILL NOT BE ABLE TO KEEP ANY PARTICULAR
12-HOUR TIME PERIOD DRY.
BASED ON FORECAST SOUNDINGS...ANY PRECIPITATION THAT DOES DEVELOP
WEDNESDAY EVENING COULD START AS RAIN AS MAXIMUM TEMPERATURES IN THE
WARM LAYER BETWEEN 950-925MB ARE 2-3C AND WET BULB TEMPERATURE IS
ABOVE 0C...EVEN ON THE COOLER NAM. HOWEVER...WARM LAYER IS
RELATIVELY SHALLOW AND COULD RAPIDLY DISAPPEAR AS EVAPORATIVE
COOLING DROPS AIR AND WET BULB TEMPERATURES...SO WILL GO WITH A
RAIN/SNOW MIX GOING OVER TO ALL SNOW AS ENTIRE COLUMN COOLS TO BELOW
0C BY/SHORTLY AFTER MIDNIGHT.
SIMILAR SCENARIO WITH PRECIPITATION TYPE THURSDAY INTO THURSDAY
NIGHT...WITH DAYTIME WARMING AND WARM ADVECTION AHEAD OF NEXT SHORT
WAVE CHANGING SNOW TO A RAIN/SNOW MIX FROM MID TO LATE MORNING...AND
ALL RAIN EXCEPT FOR A CONTINUED MIX IN THE NORTHERN CWA IN THE
AFTERNOON...THEN CHANGING BACK TO A MIX EARLY IN THE EVENING THEN
ALL SNOW WITH COLD AIR ADVECTION BEHIND WAVE.
LONG TERM...FRIDAY THROUGH MONDAY. FORECAST CONFIDENCE...LOW.
ABOUT THE ONLY CONSISTENT SIGNAL FROM THE MODELS IS A DRY PERIOD
FROM FRIDAY NIGHT THROUGH SATURDAY. BEYOND THIS PERIOD...MODELS HAVE
BEEN HIGHLY VARIABLE THAT PAST FEW DAYS WITH STRUCTURE AND TIMING OF
STRONG SHORT WAVE AND ASSOCIATED SURFACE LOW EJECTING FROM DEEPENING
WESTERN TROUGH IN THE SUNDAY/MONDAY TIME FRAME. A CONSENSUS BLEND OF
00Z AND 12Z RUNS LEANS TOWARD...BUT IS A BIT SLOWER THAN...THE
CURRENT 12Z/20 GFS RUN THAT TAKES A CLOSED SURFACE LOW ALONG A
PRAIRIE DU CHIEN TO LUDINGTON MI PATH LATE SUNDAY AFTERNOON/SUNDAY
NIGHT. THIS WOULD PUT THE HEAVIEST PCPN ACROSS CENTRAL WISCONSIN AND
POSSIBLY CLIP OUR NORTHERN COUNTIES. 12Z ECMWF HAS AN INVERTED
SURFACE TROUGH NOSING INTO THE SOUTH AT 12Z MONDAY AND LINGERING
THROUGH TUESDAY MORNING FOR A PROLONGED PERIOD OF PCPN. STAY TUNED
FOR THE LATEST DEVELOPMENTS AS MODELS WILL REMAIN VARIABLE UNTIL
HOPEFULLY LOCKING ON A MORE CONSISTENT SOLUTION IN THE NEXT FEW DAYS.
AVIATION/00Z TAFS/...VFR CONDITIONS EXPECTED WELL INTO THE EVENING
HOURS WITH GRADUALLY THICKENING MID DECK. LOWER CLOUD COVER
INCREASES LATER TONIGHT AS INFLUENCE OF CENTRAL PLAINS SHORTWAVE AND
ASSOCIATED MOISTURE DRAWS CLOSER. PROGS STILL IN DECENT AGREEMENT
WITH BRINGING LIGHT SNOW ACROSS SOUTHERN WI AFTER MIDNIGHT AND INTO
TUESDAY MORNING. THIS WILL LEAD TO AREAS OF IFR CEILINGS/VSBYS. SOME
IMPROVEMENT EXPECTED FOR THE AFTERNOON AS WINDS TURN MORE WESTERLY
IN THE WAKE OF THE TROUGH.
MARINE...TIGHTENING PRESSURE GRADIENT WILL CONTINUE TO DEVELOP OVER
LAKE MICHIGAN AS HIGH PRESSURE PUSHES FARTHER TO THE EAST WHILE LOW
PRESSURE STRENGTHENS OVER THE CENTRAL AND NORTHERN PLAINS. WILL
ALLOW SMALL CRAFT TO EXPIRE TUESDAY MORNING...BUT MAY NEED TO BE
REISSUED TUESDAY AFTERNOON INTO TUESDAY EVENING AS PRESSURE GRADIENT
RETIGHTENS AND WINDS INCREASE BEHIND SURFACE LOW PRESSURE TROUGH.
THIS TROUGH WILL BE MOVING ACROSS LAKE MICHIGAN TUESDAY MORNING
RESULTING IN THE TEMPORARY LULL IN WIND SPEEDS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 9 AM CST TUESDAY FOR LMZ643>646.
&&
$$
UPDATE...HENTZ
TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR
TUESDAY NIGHT THROUGH MONDAY...REM
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
752 AM EST TUE FEB 21 2012
.UPDATE...
QUICK UPDATE SENT TO INCREASE SNOW ACCUMULATIONS ALONG AND
NORTHEAST OF US 30 FOR THIS MORNING. LEADING EDGE OF STRONG
FORCING RAPIDLY EXPANDED AND INTENSIFIED WITH RETURNS GREATER THAN
35 DBZ SEEN. WHILE MOST LOCATIONS HAVE REMAINED AROUND 1 MILE VSBY
AND ONLY A DUSTING OF SNOW LOCATIONS UNDER THESE HIGHER RETURNS
HAVE SEEN SNOWFALL RATES OF AN INCH OR MORE PER HOUR AS DYNAMIC
COOLING HAS OFFSET APPROACHING INCREASING IN TEMPS FOR THE TIME
BEING. SFC TEMP AT THE OFFICE DROPPED 3.5 DEGREES IN ABOUT ONE
HALF HOUR WHILE UNDER THE HEAVIER BAND WITH LARGE SNOWFLAKE
PRODUCTION.
WELL PRONOUNCED CIRCULATION STILL SEEN IN WATER VAPOR LOOP TAKING
AIM ON THE AREA THIS MORNING. PRECIP MAY CONTINUE TO EXPAND BEHIND
THIS INITIAL BURST...BUT PTYPE STILL SOMEWHAT QUESTIONABLE WITH
INCREASE IN LL TEMPS STILL EXPECTED WITH ARRIVAL OF WAVE. WILL
MONITOR TRENDS OVER THE NEXT COUPLE OF HOURS FOR FURTHER UPDATES.
&&
.PREV DISCUSSION... /ISSUED 351 AM EST TUE FEB 21 2012...CORRECTION/
SHORT TERM... / TODAY THROUGH WEDNESDAY NIGHT /
POTENT NEGATIVELY TILTED SHORTWAVE OVER MISSOURI WILL TRACK QUICKLY
NEWD THROUGH THE NORTHERN OHIO VALLEY THIS MORNING...WEAKENING A BIT
AS IT BEGINS TO PHASE WITH A NORTHERN STREAM WAVE DROPPING INTO THE
UPPER MIDWEST. THIS MISSOURI NEGATIVE HEIGHT ANOMALY LOOKS
IMPRESSIVE ON WATER VAPOR THIS MORNING WITH A TROWAL CLEARLY
EVIDENT. HOWEVER QUICK MOVEMENT AND SLIGHT WEAKENING TREND WILL
RESULT IN A LIGHTER PCPN AMOUNTS LOCALLY...GENERALLY BTW
0.10-0.25". STILL EXPECTING ABOUT A 2-3 HOUR PERIOD OF ORGANIZED
PCPN...WHICH WILL BE TIED TO A NARROW PLUME OF DEEP MOIST ASCENT
ON THE NOSE OF A ~50 KT LLJ AS CPD`S RAPIDLY LOWER FROM NEAR 200
MB TO 0-5 MB ON THE 290K SFC. USED A MODEL BLEND (MORE WEIGHT TO
HIGH RES GUIDANCE) TO TIME HIGHER POPS THROUGH THE FA. VERY DRY
ANTECEDENT AIRMASS PER 00Z AREA RAOBS AND DYNAMIC NATURE TO SYSTEM
STILL DOES SUPPORT THE CHANCES FOR A RAIN/SNOW MIX NW OF HIGHWAY
24...WITH A BRIEF BURST OF SNOW POSSIBLY SUPPORTING SOME LIGHT
ACCUMS MAINLY ALONG/NORTH OF ROUTE 6 IN INDIANA AND MICHIGAN.
STEEPENING MID LVL LAPSE RATES AND STRONG DYNAMIC/EVAPORATIVE
COOLING SUPPORT THE GOING CHC FOR A BRIEF PERIOD OF WET
SNOW...ESPECIALLY GIVEN TRENDS OF LATEST 05Z HRRR AND 06Z NAM.
THE LOW LVL FLOW WILL VEER SOUTHWESTERLY BEHIND AN OCCLUDED FRONT...
ALLOWING THE LOWEST 3 KFT TO WARM WELL ABOVE FREEZING EVERYWHERE BY
LATE MORNING AND AFTERNOON. ALSO...A TIGHTENING PRESSURE GRADIENT
WILL SUPPORT A BREEZY AFTERNOON WITH GUSTS OF 20-30 MPH POSSIBLE
PER BUFR MOMENTUM TRANSFER PROGS. DEEPER MOISTURE/LIFT WILL EXIT
TO THE EAST LEAVING A LOW OVERCAST AND DRIER CONDITIONS IN ITS
WAKE. HOWEVER..LINGERING MOIST LOW LEVELS AND POSSIBLE WEAK LIFT
FROM A SECONDARY SHORTWAVE COULD STILL SPARK A FEW SHOWERS THIS
AFTERNOON INTO EARLY THIS EVENING.
A SERIES OF SHORTWAVES WILL EMERGE OUT OF A 140 KT PLUS NORTH
PACIFIC UPPER JET THAT WILL HAVE WORKED WELL INLAND INTO THE CENTRAL
PLAINS BY WEDNESDAY/WEDNESDAY NIGHT. THIS WILL SUPPORT MID LVL
TROUGHING INTO THE CENTRAL CONUS AND FAST WESTERLY FLOW ALOFT
LOCALLY. GIVEN NEGATIVE THETA-E ADV IN THE LOW LEVELS TONIGHT WOULD
EXPECT ANY SHORTWAVE ENERGY IN FAST FLOW TO HAVE TROUBLE GENERATING
ANY RAINFALL ON WEDNESDAY. THERE APPEARS TO BE A BETTER CHANCE FOR
MEASURABLE RAINFALL BY WEDNESDAY NIGHT AS A MID LEVEL BAROCLINIC
ZONE LOOKS TO TIGHTEN OVERHEAD.
LONG TERM...
HIGH ENERGY NEPAC WAVE TRAIN AND ASSOCD/INTENSE UPR JET YIELDING
EXTREME MODEL VARIABILITY W/TIME ONCE AGAIN THIS MORNING AND
ALREADY MANIFESTING ITSELF TO BEGIN THE PD ON DY3 THU. PSBL EPAC
RECON TOMORROW EVENING WILL LEAD TO MITIGATION OF THE UNCERTAINTY
LTR THIS WEEK.
REGARDLESS PRIOR GRID ALIGNMENT STILL HOLDS FOR DY3 GIVEN A CONTD
PREFERENCE/DEPENDENCE ON ECMWF W/CORRESPONDING NOD FM UKMET...BOTH
OF WHICH DIG ROBUST NRN STREAM SW SEEN IN VAPOR NR 48N/163W THIS
MORNING QUICKER AND FARTHER WEST WHILE GFS SYSTEMIC PROGRESSION
BIASES RENDER ITS SOLUTION SUSPECT. THIS HWVR DOES NECESSITATE CHGS
FRI AS MID LVL DEFORMATION ZONE IS MORE LIKELY TO HANG BACK IN
RESPONSE TO SIG ERN OH VALLEY CYCLOGENESIS AT LEAST THROUGH MORNING.
OTHERWISE CHGS BEYOND DY4 DEEMED FUTILE GIVEN RAMPANT MODEL SPREAD
AND UNCERTAINTY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 11 AM EST
WEDNESDAY FOR LMZ043-046.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...T
UPDATE...FISHER
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1022 AM EST TUE FEB 21 2012
.SYNOPSIS...
AN EASTBOUND OCCLUDED FRONT WILL PROVIDE SHOWERS AND GUSTY WINDS
TODAY, KEEPING TEMPERATURES MILD INTO THURSDAY. A STRONGER COLD
FRONT PASSES FRIDAY, USHERING IN COLD WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH RECENT HRRR AND
NAM MODEL OUTPUT, EXPECT A FRONTAL BAND OF SHOWERS TO QUICKLY
PINWHEEL EASTWARD THROUGH THE UPPER OHIO VALLEY THROUGH THE
AFTERNOON. DUE TO INITIAL DRYNESS OF THE SURFACE LAYER, THERE CAN
BE SUFFICIENT EVAPORATIONAL COOLING FOR A SHORT PERIOD OF SNOW
SHOWERS AT THE START, BUT THERE WILL NOT BE ANY ACCUMULATION.
MORE NOTEWORTHY IS THAT SURFACE WINDS CAN GUST UP TO 35 TO 40 MPH
IN THE WAKE OF THESE SHOWERS.
TEMPERATURE DETAILS WERE BASED ON BLEND OF RECENT HRRR, NAM, AND
GFS LAMP OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
RAIN CHANCES SHOULD DECREASE AS A SHORT WAVE TROUGH EXITS TO THE
NORTHEAST TONIGHT, BUT A SURFACE BOUNDARY STRETCHED ACROSS THE
FORECAST AREA WILL MAINTAIN AT LEAST A CHANCE OF SHOWERS WEDNESDAY
INTO WEDNESDAY NIGHT.
MODELS SHOW A SURFACE LOW TRACKING EAST ACROSS THE GREAT LAKES
WITH A WARM FRONT PUSHING THROUGH THE UPPER OHIO VALLEY THURSDAY.
RAIN CHANCES WILL INCREASE AND TEMPERATURES SHOULD WARM INTO THE
50S TO LOWER 60S IN THE WARM SECTOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
VERY LITTLE CONFIDENCE IN THE LONG TERM AS MODEL DIFFERENCES MAKE
IT DIFFICULT TO PIN DOWN A CONSISTENT FORECAST.
STRONG FRONT WILL PASS THROUGH ON FRIDAY, BUT STILL DISCREPANCIES
ON TIMING AND IF SFC WAVE WILL DEVELOP ALONG THE FRONT.
MUCH COLDER AIR FOR THE WEEKEND. WITH LES POSSIBLE SATURDAY INTO
EARLY SUNDAY.
DIFFERENCES IN SOLUTIONS CONTINUE INTO THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND HRRR MODEL OUTPUT, EXPECT A FRONTAL BAND OF
MVFR SHOWERS TO PINWHEEL EASTWARD THROUGH THE UPPER OHIO VALLEY
TODAY. FOR KZZV, THERE CAN BE UP TO 1 HOUR PERIOD OF IFR WITH SNOW
SHOWERS DUE TO EVAPORATIONAL COOLING WITHIN INITIALLY DRY SURFACE
LAYER. WINDS CAN GUST TO 35 KTS IN THE WAKE OF THE SHOWERS. THE SHOWERS
WILL HAVE PASSED EAST OF KZZV BY 16Z, AND AFFECT TAF SITES KFKL,
KPIT AND KMGW 16Z-19Z, AND KLBE AND KDUJ 17Z-20Z.
OUTLOOK...TONIGHT THROUGH SATURDAY...
VFR TONIGHT WITH SUBSIDING WIND. RESTRICTIONS POSSIBLE WITH FRONTAL
BANDS OF RAIN SHOWERS WEDNESDAY AND THURSDAY. A MORE PROLONGED
PERIOD OF RESTRICTIONS POSSIBLE FRIDAY INTO SATURDAY DUE TO A
STRONG COLD FRONTAL PASSAGE FRIDAY, WITH RAIN SHOWERS FRIDAY,
FOLLOWED BY COLD POOL LOW CLOUDS AND SCATTERED SNOW SHOWERS FRIDAY
NIGHT INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
845 AM EST TUE FEB 21 2012
.SYNOPSIS...
AN EASTBOUND OCCLUDED FRONT WILL PROVIDE SHOWERS AND GUSTY WINDS
TODAY, KEEPING TEMPERATURES MILD INTO THURSDAY. A STRONGER COLD
FRONT PASSES FRIDAY, USHERING IN COLD WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PER RECENT SURFACE AND RADAR DATA, COUPLED WITH RECENT HRRR AND
NAM MODEL OUTPUT, EXPECT A FRONTAL BAND OF SHOWERS TO QUICKLY
PINWHEEL EASTWARD THROUGH THE UPPER OHIO VALLEY TODAY. DUE TO
INITIAL DRYNESS OF THE SURFACE LAYER, ITS POSSIBLE THERE MAY BE
SUFFICIENT EVAPORATIONAL COOLING FOR A FEW SNOW FLAKES AT THE
START, BUT THERE WILL NOT BE ANY ACCUMULATION. MORE NOTEWORTHY IS
THAT SURFACE WINDS CAN GUST UP TO 35 TO 40 MPH IN THE WAKE OF
THESE SHOWERS.
TEMPERATURE DETAILS WERE BASED ON BLEND OF RECENT HRRR, NAM, AND
GFS LAMP OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
RAIN CHANCES SHOULD DECREASE AS A SHORT WAVE TROUGH EXITS TO THE
NORTHEAST TONIGHT, BUT A SURFACE BOUNDARY STRETCHED ACROSS THE
FORECAST AREA WILL MAINTAIN AT LEAST A CHANCE OF SHOWERS WEDNESDAY
INTO WEDNESDAY NIGHT.
MODELS SHOW A SURFACE LOW TRACKING EAST ACROSS THE GREAT LAKES
WITH A WARM FRONT PUSHING THROUGH THE UPPER OHIO VALLEY THURSDAY.
RAIN CHANCES WILL INCREASE AND TEMPERATURES SHOULD WARM INTO THE
50S TO LOWER 60S IN THE WARM SECTOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
VERY LITTLE CONFIDENCE IN THE LONG TERM AS MODEL DIFFERENCES MAKE
IT DIFFICULT TO PIN DOWN A CONSISTENT FORECAST.
STRONG FRONT WILL PASS THROUGH ON FRIDAY, BUT STILL DISCREPANCIES
ON TIMING AND IF SFC WAVE WILL DEVELOP ALONG THE FRONT.
MUCH COLDER AIR FOR THE WEEKEND. WITH LES POSSIBLE SATURDAY INTO
EARLY SUNDAY.
DIFFERENCES IN SOLUTIONS CONTINUE INTO THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
PER RECENT SURFACE AND HRRR MODEL OUTPUT, EXPECT A FRONTAL BAND OF
MVFR SHOWERS TO PINWHEEL EASTWARD THROUGH THE UPPER OHIO VALLEY
TODAY. WINDS CAN GUST TO 35 KTS IN THEIR WAKE. THE SHOWERS WILL
HAVE PASSED EAST OF KZZV BY 15Z, AND AFFECT TAF SITES KFKL, KPIT
AND KMGW 15Z-19Z, AND KLBE AND KDUJ 16Z-20Z.
OUTLOOK...TONIGHT THROUGH SATURDAY...
VFR TONIGHT WITH SUBSIDING WIND. RESTRICTIONS POSSIBLE WITH FRONTAL
BANDS OF RAIN SHOWERS WEDNESDAY AND THURSDAY. A MORE PROLONGED
PERIOD OF RESTRICTIONS POSSIBLE FRIDAY INTO SATURDAY DUE TO A
STRONG COLD FRONTAL PASSAGE FRIDAY, WITH RAIN SHOWERS FRIDAY,
FOLLOWED BY COLD POOL LOW CLOUDS AND SCATTERED SNOW SHOWERS FRIDAY
NIGHT INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1005 AM EST TUE FEB 21 2012
.UPDATE...
ISSUED AT 1002 AM EST TUE FEB 21 2012
NO CHANGES MADE TO GOING FORECAST AT THIS POINT...WILL MAKE TWEAKS
AS NEEDED GOING FORWARD WITH RESPECT TO PRECIPITATION START TIMES.
UPDATE ISSUED AT 642 AM EST TUE FEB 21 2012
PRECIPITATION ONSET LOOKING ON TRACK GIVEN CURRENT OBSERVATIONS
SHOWING SNOW BREAKING OUT OVER SOUTHEAST WISCONSIN AND LIKELY OVER
THE SOUTHERN THIRD OF LAKE MICHIGAN AT THIS HOUR. RAOB JUST SENT
UP AT APX SHOWS IMPRESSIVE DRY WEDGE TO OVERCOME /30C DEWPOINT
DEPRESSIONS AT H85 WITH DRY WEDGE EXTENDING TO H6/ SO EXPECT THAT
WHILE CURRENT RADAR ECHOES LOOK A LITTLE OMINOUS...IT WILL TAKE
MANY MORE HOURS FOR PRECIPITATION TO FILL IN. THIS IS IN GOOD
AGREEMENT WITH 08/09Z HRRR WHICH SUGGESTS THAT PRECIPITATION WILL
STRUGGLE TO MAKE IT MUCH FURTHER NORTH THAN M-72 BY NOON.
SO...LITTLE TWEAKS IN THE POP/WEATHER DEPARTMENT. UPDATED SKY
BASED ON SLIGHTLY FASTER CLOUD-UP OVER EASTERN UPPER...BUT
OTHERWISE...LITTLE CHANGES NEEDED IN THIS UPDATE.
&&
.SYNOPSIS...
ISSUED AT 333 AM EST TUE FEB 21 2012
HIGH PRESSURE WILL EXIT INTO THE WESTERN ATLANTIC TODAY...AS
WEAKENING LOW PRESSURE TRACKS THROUGH THE GREAT LAKES INTO THIS
EVENING. THIS SYSTEM WILL BRING A BRIEF ROUND OF LIGHT RAIN AND SNOW
SHOWERS TO THE REGION THROUGH LATE EVENING...THOUGH WITH LITTLE TO
NO SNOW ACCUMULATION EXPECTED. LOOKING INTO THE REST OF THE WORK
WEEK...SEVERAL ADDITIONAL WEAK WEATHER SYSTEMS WILL PROGRESS THROUGH
THE AREA...EACH SUPPLYING SMALL CHANCES FOR SOME LIGHT RAIN OR SNOW.
HOWEVER...NO SIGNIFICANT SNOW ACCUMULATION IS EXPECTED THROUGH AT
LEAST SATURDAY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
EARLY MORNING SURFACE ANALYSIS REVEALS DOUBLE-BARRELED LOW PRESSURE
SYSTEM ADVANCING NORTH AND EAST TOWARDS THE FORECAST AREA. 30-40 KT
LOW LEVEL JET RIDING UP AND OVER LOW LEVEL COOL DOME HAS PRODUCED A
FAIRLY WIDESPREAD REGION OF GENERALLY LIGHT PRECIPITATION THAT IS
PUSHING INTO EASTERN WISCONSIN AS OF THIS WRITING. DOUBLE BARRELED
STRUCTURE AT THE SURFACE HAS BEEN PRODUCED BY COMPETING MID AND
UPPER LEVEL SHORTWAVES...ONE COMPACT CENTER OVER NORTHERN MISSOURI
AND ANOTHER LARGER SCALE FEATURE OVER NORTH DAKOTA. MODEL TRENDS
OVER THE PAST 48 HOURS HAVE BEEN FOR A STRONGER AND FURTHER SOUTH
NORTHERN FEATURE...WHICH WILL DO A GOOD JOB OF KICKING THE SOUTHERN
WAVE SOUTH AND EAST OF OUR REGION TODAY. THIS LEAVES A GENERALLY
WEAK FORCING FOR ASCENT AS THE BEST DEEP MOISTURE SHIFTS EAST WITH
THE SOUTHERN WAVE...ALLOWING ONLY MODEST MOISTENING IN OUR REGION AS
MODEST QVECTOR CONVERGENCE AND FGEN FORCING ARRIVE.
00Z RAOBS FROM APX/GRB SHOW A PRETTY DRY ANTECEDENT AIRMASS WITH
PWATS BELOW TWO TENTHS OF AN INCH WITH DRY SOUTHEASTERLY FLOW IN THE
LOW LEVELS HELPING KEEP THIS DRY PROFILE IN PLACE. SO...MODEL
TRENDS FOR SLOWER PRECIPITATION ARRIVAL...AND LOWER PRECIPITATION
AMOUNTS ARE NOT A SURPRISE...AND EXPECT MINIMAL IMPACTS FOR THE
REGION TODAY. LIGHT SNOW...WHICH MAY ARRIVE IN BROKEN ELEMENTS
RATHER THAN A SOLID SHIELD...SHOULD ADVANCE FROM SOUTHWEST TO
NORTHEAST ACROSS NORTHERN LOWER BY BY NOON...WITH ANY ACTIVITY
HOLDING OFF IN EASTERN UPPER UNTIL LATE IN THE DAY. PRECIPITATION
COVERAGE MAY ACTUALLY INCREASE SOME TOWARDS EVENING AS QG FORCING
ASSOCIATED WITH THE NORTHERN STREAM FINALLY ARRIVES...WITH
INCREASINGLY CYCLONIC BOUNDARY LAYER FLOW ALSO ASSISTING.
A MIX WITH RAIN ALSO LOOKS TO BE IN THE CARDS...AS BOUNDARY LAYER
TEMPERATURES MAKE A RUN AT THE UPPER 30S NEAR THE LAKES AS
PRECIPITATION ARRIVES. THIS WILL ALSO BE HELPED BY THE GENERALLY
LIGHT PRECIPITATION RATES...WHICH WILL BETTER ALLOW THE SURFACE
LAYER TO DICTATE PRECIPITATION TYPE. EVEN WHERE PRECIPITATION
REMAINS ALL SNOW...INCREASING SUN ANGLES /EVEN WITH CLOUD COVER/
SUGGESTS THAT EVEN OVER THE HIGHER TERRAIN OF NORTHERN LOWER...WHERE
PRECIPITATION REMAINS ALL SNOW...THE HALF INCH OF SNOW EXPECTED WILL
HAVE TROUBLE STICKING TO AREA ROADWAYS.
AFOREMENTIONED SURFACE LOW SETTLES OVER NORTHERN LAKE SUPERIOR
TONIGHT WITH T85S FALLING TO ABOUT -8C WITH CONTINUED DECENT
SYNOPTIC MOISTURE AND CYCLONIC LLEVEL FLOW SUGGESTING LAKE ENHANCED
SHSN ACTIVITY WILL LIKELY PERSIST THROUGH MUCH OF THE NIGHT. WITH
COOLING BOUNDARY LAYER TEMPERATURES...EXPECT SNOW TO STICK A LITTLE
BETTER AND HAVE PAINTED UP TO AN INCH IN THE FORECAST OVERNIGHT OVER
EASTERN UPPER...AS WELL AS THE HIGHER TERRAIN OF NORTHERN LOWER
WHERE SOME UPSLOPE ENHANCEMENT UNDER WEST-SOUTHWEST FLOW WILL BOOST
PRECIPITATION TOTALS SLIGHTLY. WILL LEAN TOWARDS THE WARMER END OF
THE GUIDANCE SUITE FOR TEMPERATURES GIVEN CLOUD COVER AND
PRECIPITATION...WITH UPPER 20S LOOKING GOOD FOR MOST SPOTS.
LOW PRESSURE NORTH OF THE REGION GRADUALLY FILLS AND SHIFTS EAST ON
WEDNESDAY WITH A GRADUAL DOWN-TICK IN MOISTURE AND SLIGHT WARMING OF
TEMPS AT H85. THIS INDICATES THAT SHSN ACTIVITY WILL GRADUALLY
BECOME MORE AND MORE RESTRICTED TO NEAR THE LOW CENTER /EASTERN
UPPER/ AND WILL ALLOW POPS TO GRADUALLY FADE NORTH DURING THE DAY.
LIKELIES LOOK GOOD FOR A TIME EARLY...HOWEVER AS THERE IS NO SUDDEN
INFLUX OF DRY/WARM AIR TO SHUT THINGS DOWN. WHILE THERE WILL BE A
GOOD DEAL OF CLOUD COVER...T92 AROUND -3C SUGGEST MID TO PERHAPS
UPPER 30S WILL AGAIN BE IN ORDER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
WEDNESDAY NIGHT THROUGH FRIDAY...CONVOLUTED PATTERN EXPECTED ACROSS
THE GREAT LAKES REGION TO WRAP UP THE WORK WEEK...WITH HONESTLY NOT
VERY HIGH CONFIDENCE IN ANY TIMING OF VARIOUS PRECIP CHANCES.
SECONDARY SHORTWAVE OF SHORT TERM MENTION ABOVE OVER THE NORTHERN
PLAINS WILL BE EXITING STAGE RIGHT WEDNESDAY EVENING...LEAVING
IMPRESSIVE PLUME OF PACIFIC JET ENERGY TO FLOOD JUST ABOUT THE
ENTIRE CONUS HEADING INTO FRIDAY. EMBEDDED WITHIN THE FLOW ARE
SEVERAL PROGGED SHORTWAVES...THOUGH THEIR PLACEMENT AND TIMING VARY
CONSIDERABLY FROM RUN TO RUN AND MODEL TO MODEL. ABOUT THE ONLY
THING THAT CAN BE SAID WITH SOME CONFIDENCE IS THAT VARIOUS MAINLY
SMALL PRECIP CHANCES WILL EXIST DURING THE LATE WEEK PERIOD...THOUGH
HIGHLY DOUBTING THE AMPLIFIED SOLUTIONS OF THE BOTH THE 21/00Z NAM
AND 20/12Z ECMWF GIVEN THE RAGING PACIFIC "FIREHOSE" JET ENERGY THAT
SHOULD EASILY KEEP THE FLOW PROGRESSIVE. INSTEAD WE APPEAR TO BE
LEFT WITH A MYRIAD OF WEAKER UPPER WAVES THAT WILL TRAVERSE A
BRIEFLY STATIONARY TIGHT THERMAL GRADIENT RESIDING OVER THE SOUTHERN
GREAT LAKES. AS SUCH...PRECIP CHANCES SHOULD BE GREATEST OVER
SOUTHERN COUNTIES...AND ENTIRELY POSSIBLE THAT NOT A WHOLE LOT
HAPPENS NORTH OF M-72. STILL...GIVEN PLENTY OF UNCERTAINTY...WILL
MAINTAIN SMALL CHANCE POPS PRETTY MUCH AREAWIDE...THOUGH WILL REMOVE
PRECIP MENTION NORTH OF M-72 ON THURSDAY. WILL ALSO KEEP PRECIP TYPE
AS ALL SNOW AT THIS POINT...THOUGH SOME HINTS EXIST THAT A RAIN/SNOW
MIX IS POSSIBLE ACROSS SOUTHERN AREAS ON THURSDAY AS STRONGER
SHORTWAVE ARRIVES. TEMPS BASICALLY TO CONTINUE ABOVE NORMAL THROUGH
THE PERIOD...MAINLY DRIVEN BY MILD OVERNIGHT LOWS.
LATER PERIODS (FRIDAY NIGHT THROUGH MONDAY)...POTENTIALLY MORE
ACTIVE WEATHER PATTERN STILL APPEARS IN THE WORKS HEADING INTO LATE
WEEKEND...AND MORE LIKELY THE FIRST HALF OF NEXT WEEK...WITH
INCREASING SIGNS OF STRONG NORTH PACIFIC JET COLLAPSING INTO SOME
DEGREE OF WESTERN CONUS TROUGHING. THIS SHOULD HAVE THE NEXT EFFECT
OF SLOWING DOWN THE WAVE TRAIN THROUGH THE CONUS...ALLOWING MORE
TIME FOR AMPLIFICATION OF VARIOUS FEATURES...AND PERHAPS SETTING UP
A SOUTHWEST FLOW REGIME FOR A TIME FROM LATER SUNDAY THROUGH MIDWEEK
(SOMETHING NOT SEEN AT ALL THIS WINTER BUT MUCH MORE TYPICAL OF A LA
NINA EPISODE). CONFIDENCE WITH ANY PARTICULAR PIECE OF GUIDANCE IS
VERY LOW...BUT THE FLAVOR OF THE FORECAST WILL REMAIN INTACT...
FEATURING INCREASING CHANCES FOR SNOW THROUGH MONDAY. AT THIS
JUNCTURE...TEMPS LOOK TO AVERAGE ABOUT NORMAL...THOUGH BIG BUST
POTENTIAL IS THERE LATE IN THE PERIOD SHOULD ANY SYSTEM AMPLIFY
SIGNIFICANT TO OUR WEST (WHICH WOULD HELP DRAG UP SOME QUITE WARM
AIR THIS WAY).
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 642 AM EST TUE FEB 21 2012
VFR CONDITIONS CONTINUE AT EACH OF THE TAF SITES...BUT
DETERIORATING CONDITIONS ARE EXPECTED AS AXIS OF LOW PRESSURE
SHIFTS TOWARDS THE AREA FROM THE SOUTHWEST...BRINGING A ROUND OF
SNOW...WHICH MAY BE MIXED WITH RAIN.
EXPECT MVFR-IFR CIGS/VSBYS IN LIGHT SNOW TO ARRIVE AT MBL/TVC LATE
THIS MORNING...AND PLN/APN THIS AFTERNOON. AT THIS TIME...EXPECT
PRECIPITATION TO BE QUITE LIGHT...WITH VSBYS LIKELY HAVING TROUBLE
REMAINING IFR FOR MORE THAN A FEW HOURS. ALSO...SOME RAIN MAY MIX
WITH THE SNOW AT TIMES AT MBL/TVC. THIS EVENING...AS THE INITIAL
BATCH OF PRECIPITATION SHIFT NORTH AND EAST...EXPECT RESIDUAL LAKE
ENHANCED SHSN THROUGH THE OVERNIGHT AT APN/PLN...WITH MVFR
CONDITIONS /PERHAPS IFR VSBYS AT PLN?/ PERSISTING THROUGH 12Z
WEDNESDAY. MORE IMPROVEMENT IS EXPECTED AT TVC...AND EXPECIALLY
MBL WHERE A RETURN TO VFR CIGS IS EXPECTED AFTER MIDNIGHT.
AS FOR WINDS...LLWS CONCERNS ARE ENDING AT THIS HOUR AS MIXING
STRENGTHENS AT LOW LEVELS. EXPECT SOUTHEAST WINDS 5-10KTS TO VEER
SOUTHERLY 5-10KTS DURING THE DAY TODAY...BEFORE SHIFTING SOUTHWEST
AND INCREASING TO 12G18KTS TONIGHT.
&&
.MARINE...
ISSUED AT 333 AM EST TUE FEB 21 2012
SMALL CRAFTS ONGOING OVER ALL NEARSHORE ZONES...AND EXPECT THIS TO
CONTINUE THROUGH AT LEAST WEDNESDAY AS LOW PRESSURE TAKING SHAPE
OVER NORTHERN MINNESOTA TODAY SHIFTS OVER LAKE SUPERIOR TONIGHT WITH
SOUTHEAST WINDS SHIFTING SOUTHWEST TONIGHT. WINDS/WAVES SHOULD
SUBSIDE WEDNESDAY NIGHT AND THURSDAY AS WEAK AREA OF HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST. AS THE WINDS SHIFT SOUTHWEST
TONIGHT...CAN/T COMPLETELY RULE OUT A FEW LOW-END GALES ON THE
NORTHWEST LAKE MICHIGAN COAST...BUT FLOW TRAJECTORY DOES NOT FAVOR
MUCH IN THE WAY OF COASTAL CONVERGENCE ENHANCEMENT...SO EXPECT MOST
SPOTS TO GUST TO AROUND 30KTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR LHZ346-349.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR LMZ323-341-342-
344-345-346.
LS...NONE.
&&
$$
UPDATE...JPB
SHORT TERM...ARNOTT
LONG TERM....LAWRENCE
AVIATION...ARNOTT
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS GAYLORD MI
645 AM EST TUE FEB 21 2012
.UPDATE...
ISSUED AT 642 AM EST TUE FEB 21 2012
PRECIPITATION ONSET LOOKING ON TRACK GIVEN CURRENT OBSERVATIONS
SHOWING SNOW BREAKING OUT OVER SOUTHEAST WISCONSIN AND LIKELY OVER
THE SOUTHERN THIRD OF LAKE MICHIGAN AT THIS HOUR. RAOB JUST SENT
UP AT APX SHOWS IMPRESSIVE DRY WEDGE TO OVERCOME /30C DEWPOINT
DEPRESSIONS AT H85 WITH DRY WEDGE EXTENDING TO H6/ SO EXPECT THAT
WHILE CURRENT RADAR ECHOES LOOK A LITTLE OMINOUS...IT WILL TAKE
MANY MORE HOURS FOR PRECIPITATION TO FILL IN. THIS IS IN GOOD
AGREEMENT WITH 08/09Z HRRR WHICH SUGGESTS THAT PRECIPITATION WILL
STRUGGLE TO MAKE IT MUCH FURTHER NORTH THAN M-72 BY NOON.
SO...LITTLE TWEAKS IN THE POP/WEATHER DEPARTMENT. UPDATED SKY
BASED ON SLIGHTLY FASTER CLOUD-UP OVER EASTERN UPPER...BUT
OTHERWISE...LITTLE CHANGES NEEDED IN THIS UPDATE.
&&
.SYNOPSIS...
ISSUED AT 333 AM EST TUE FEB 21 2012
HIGH PRESSURE WILL EXIT INTO THE WESTERN ATLANTIC TODAY...AS
WEAKENING LOW PRESSURE TRACKS THROUGH THE GREAT LAKES INTO THIS
EVENING. THIS SYSTEM WILL BRING A BRIEF ROUND OF LIGHT RAIN AND SNOW
SHOWERS TO THE REGION THROUGH LATE EVENING...THOUGH WITH LITTLE TO
NO SNOW ACCUMULATION EXPECTED. LOOKING INTO THE REST OF THE WORK
WEEK...SEVERAL ADDITIONAL WEAK WEATHER SYSTEMS WILL PROGRESS THROUGH
THE AREA...EACH SUPPLYING SMALL CHANCES FOR SOME LIGHT RAIN OR SNOW.
HOWEVER...NO SIGNIFICANT SNOW ACCUMULATION IS EXPECTED THROUGH AT
LEAST SATURDAY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
EARLY MORNING SURFACE ANALYSIS REVEALS DOUBLE-BARRELED LOW PRESSURE
SYSTEM ADVANCING NORTH AND EAST TOWARDS THE FORECAST AREA. 30-40 KT
LOW LEVEL JET RIDING UP AND OVER LOW LEVEL COOL DOME HAS PRODUCED A
FAIRLY WIDESPREAD REGION OF GENERALLY LIGHT PRECIPITATION THAT IS
PUSHING INTO EASTERN WISCONSIN AS OF THIS WRITING. DOUBLE BARRELED
STRUCTURE AT THE SURFACE HAS BEEN PRODUCED BY COMPETING MID AND
UPPER LEVEL SHORTWAVES...ONE COMPACT CENTER OVER NORTHERN MISSOURI
AND ANOTHER LARGER SCALE FEATURE OVER NORTH DAKOTA. MODEL TRENDS
OVER THE PAST 48 HOURS HAVE BEEN FOR A STRONGER AND FURTHER SOUTH
NORTHERN FEATURE...WHICH WILL DO A GOOD JOB OF KICKING THE SOUTHERN
WAVE SOUTH AND EAST OF OUR REGION TODAY. THIS LEAVES A GENERALLY
WEAK FORCING FOR ASCENT AS THE BEST DEEP MOISTURE SHIFTS EAST WITH
THE SOUTHERN WAVE...ALLOWING ONLY MODEST MOISTENING IN OUR REGION AS
MODEST QVECTOR CONVERGENCE AND FGEN FORCING ARRIVE.
00Z RAOBS FROM APX/GRB SHOW A PRETTY DRY ANTECEDENT AIRMASS WITH
PWATS BELOW TWO TENTHS OF AN INCH WITH DRY SOUTHEASTERLY FLOW IN THE
LOW LEVELS HELPING KEEP THIS DRY PROFILE IN PLACE. SO...MODEL
TRENDS FOR SLOWER PRECIPITATION ARRIVAL...AND LOWER PRECIPITATION
AMOUNTS ARE NOT A SURPRISE...AND EXPECT MINIMAL IMPACTS FOR THE
REGION TODAY. LIGHT SNOW...WHICH MAY ARRIVE IN BROKEN ELEMENTS
RATHER THAN A SOLID SHIELD...SHOULD ADVANCE FROM SOUTHWEST TO
NORTHEAST ACROSS NORTHERN LOWER BY BY NOON...WITH ANY ACTIVITY
HOLDING OFF IN EASTERN UPPER UNTIL LATE IN THE DAY. PRECIPITATION
COVERAGE MAY ACTUALLY INCREASE SOME TOWARDS EVENING AS QG FORCING
ASSOCIATED WITH THE NORTHERN STREAM FINALLY ARRIVES...WITH
INCREASINGLY CYCLONIC BOUNDARY LAYER FLOW ALSO ASSISTING.
A MIX WITH RAIN ALSO LOOKS TO BE IN THE CARDS...AS BOUNDARY LAYER
TEMPERATURES MAKE A RUN AT THE UPPER 30S NEAR THE LAKES AS
PRECIPITATION ARRIVES. THIS WILL ALSO BE HELPED BY THE GENERALLY
LIGHT PRECIPITATION RATES...WHICH WILL BETTER ALLOW THE SURFACE
LAYER TO DICTATE PRECIPITATION TYPE. EVEN WHERE PRECIPITATION
REMAINS ALL SNOW...INCREASING SUN ANGLES /EVEN WITH CLOUD COVER/
SUGGESTS THAT EVEN OVER THE HIGHER TERRAIN OF NORTHERN LOWER...WHERE
PRECIPITATION REMAINS ALL SNOW...THE HALF INCH OF SNOW EXPECTED WILL
HAVE TROUBLE STICKING TO AREA ROADWAYS.
AFOREMENTIONED SURFACE LOW SETTLES OVER NORTHERN LAKE SUPERIOR
TONIGHT WITH T85S FALLING TO ABOUT -8C WITH CONTINUED DECENT
SYNOPTIC MOISTURE AND CYCLONIC LLEVEL FLOW SUGGESTING LAKE ENHANCED
SHSN ACTIVITY WILL LIKELY PERSIST THROUGH MUCH OF THE NIGHT. WITH
COOLING BOUNDARY LAYER TEMPERATURES...EXPECT SNOW TO STICK A LITTLE
BETTER AND HAVE PAINTED UP TO AN INCH IN THE FORECAST OVERNIGHT OVER
EASTERN UPPER...AS WELL AS THE HIGHER TERRAIN OF NORTHERN LOWER
WHERE SOME UPSLOPE ENHANCEMENT UNDER WEST-SOUTHWEST FLOW WILL BOOST
PRECIPITATION TOTALS SLIGHTLY. WILL LEAN TOWARDS THE WARMER END OF
THE GUIDANCE SUITE FOR TEMPERATURES GIVEN CLOUD COVER AND
PRECIPITATION...WITH UPPER 20S LOOKING GOOD FOR MOST SPOTS.
LOW PRESSURE NORTH OF THE REGION GRADUALLY FILLS AND SHIFTS EAST ON
WEDNESDAY WITH A GRADUAL DOWN-TICK IN MOISTURE AND SLIGHT WARMING OF
TEMPS AT H85. THIS INDICATES THAT SHSN ACTIVITY WILL GRADUALLY
BECOME MORE AND MORE RESTRICTED TO NEAR THE LOW CENTER /EASTERN
UPPER/ AND WILL ALLOW POPS TO GRADUALLY FADE NORTH DURING THE DAY.
LIKELIES LOOK GOOD FOR A TIME EARLY...HOWEVER AS THERE IS NO SUDDEN
INFLUX OF DRY/WARM AIR TO SHUT THINGS DOWN. WHILE THERE WILL BE A
GOOD DEAL OF CLOUD COVER...T92 AROUND -3C SUGGEST MID TO PERHAPS
UPPER 30S WILL AGAIN BE IN ORDER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
WEDNESDAY NIGHT THROUGH FRIDAY...CONVOLUTED PATTERN EXPECTED ACROSS
THE GREAT LAKES REGION TO WRAP UP THE WORK WEEK...WITH HONESTLY NOT
VERY HIGH CONFIDENCE IN ANY TIMING OF VARIOUS PRECIP CHANCES.
SECONDARY SHORTWAVE OF SHORT TERM MENTION ABOVE OVER THE NORTHERN
PLAINS WILL BE EXITING STAGE RIGHT WEDNESDAY EVENING...LEAVING
IMPRESSIVE PLUME OF PACIFIC JET ENERGY TO FLOOD JUST ABOUT THE
ENTIRE CONUS HEADING INTO FRIDAY. EMBEDDED WITHIN THE FLOW ARE
SEVERAL PROGGED SHORTWAVES...THOUGH THEIR PLACEMENT AND TIMING VARY
CONSIDERABLY FROM RUN TO RUN AND MODEL TO MODEL. ABOUT THE ONLY
THING THAT CAN BE SAID WITH SOME CONFIDENCE IS THAT VARIOUS MAINLY
SMALL PRECIP CHANCES WILL EXIST DURING THE LATE WEEK PERIOD...THOUGH
HIGHLY DOUBTING THE AMPLIFIED SOLUTIONS OF THE BOTH THE 21/00Z NAM
AND 20/12Z ECMWF GIVEN THE RAGING PACIFIC "FIREHOSE" JET ENERGY THAT
SHOULD EASILY KEEP THE FLOW PROGRESSIVE. INSTEAD WE APPEAR TO BE
LEFT WITH A MYRIAD OF WEAKER UPPER WAVES THAT WILL TRAVERSE A
BRIEFLY STATIONARY TIGHT THERMAL GRADIENT RESIDING OVER THE SOUTHERN
GREAT LAKES. AS SUCH...PRECIP CHANCES SHOULD BE GREATEST OVER
SOUTHERN COUNTIES...AND ENTIRELY POSSIBLE THAT NOT A WHOLE LOT
HAPPENS NORTH OF M-72. STILL...GIVEN PLENTY OF UNCERTAINTY...WILL
MAINTAIN SMALL CHANCE POPS PRETTY MUCH AREAWIDE...THOUGH WILL REMOVE
PRECIP MENTION NORTH OF M-72 ON THURSDAY. WILL ALSO KEEP PRECIP TYPE
AS ALL SNOW AT THIS POINT...THOUGH SOME HINTS EXIST THAT A RAIN/SNOW
MIX IS POSSIBLE ACROSS SOUTHERN AREAS ON THURSDAY AS STRONGER
SHORTWAVE ARRIVES. TEMPS BASICALLY TO CONTINUE ABOVE NORMAL THROUGH
THE PERIOD...MAINLY DRIVEN BY MILD OVERNIGHT LOWS.
LATER PERIODS (FRIDAY NIGHT THROUGH MONDAY)...POTENTIALLY MORE
ACTIVE WEATHER PATTERN STILL APPEARS IN THE WORKS HEADING INTO LATE
WEEKEND...AND MORE LIKELY THE FIRST HALF OF NEXT WEEK...WITH
INCREASING SIGNS OF STRONG NORTH PACIFIC JET COLLAPSING INTO SOME
DEGREE OF WESTERN CONUS TROUGHING. THIS SHOULD HAVE THE NEXT EFFECT
OF SLOWING DOWN THE WAVE TRAIN THROUGH THE CONUS...ALLOWING MORE
TIME FOR AMPLIFICATION OF VARIOUS FEATURES...AND PERHAPS SETTING UP
A SOUTHWEST FLOW REGIME FOR A TIME FROM LATER SUNDAY THROUGH MIDWEEK
(SOMETHING NOT SEEN AT ALL THIS WINTER BUT MUCH MORE TYPICAL OF A LA
NINA EPISODE). CONFIDENCE WITH ANY PARTICULAR PIECE OF GUIDANCE IS
VERY LOW...BUT THE FLAVOR OF THE FORECAST WILL REMAIN INTACT...
FEATURING INCREASING CHANCES FOR SNOW THROUGH MONDAY. AT THIS
JUNCTURE...TEMPS LOOK TO AVERAGE ABOUT NORMAL...THOUGH BIG BUST
POTENTIAL IS THERE LATE IN THE PERIOD SHOULD ANY SYSTEM AMPLIFY
SIGNIFICANT TO OUR WEST (WHICH WOULD HELP DRAG UP SOME QUITE WARM
AIR THIS WAY).
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 642 AM EST TUE FEB 21 2012
VFR CONDITIONS CONTINUE AT EACH OF THE TAF SITES...BUT
DETERIORATING CONDITIONS ARE EXPECTED AS AXIS OF LOW PRESSURE
SHIFTS TOWARDS THE AREA FROM THE SOUTHWEST...BRINGING A ROUND OF
SNOW...WHICH MAY BE MIXED WITH RAIN.
EXPECT MVFR-IFR CIGS/VSBYS IN LIGHT SNOW TO ARRIVE AT MBL/TVC LATE
THIS MORNING...AND PLN/APN THIS AFTERNOON. AT THIS TIME...EXPECT
PRECIPITATION TO BE QUITE LIGHT...WITH VSBYS LIKELY HAVING TROUBLE
REMAINING IFR FOR MORE THAN A FEW HOURS. ALSO...SOME RAIN MAY MIX
WITH THE SNOW AT TIMES AT MBL/TVC. THIS EVENING...AS THE INITIAL
BATCH OF PRECIPITATION SHIFT NORTH AND EAST...EXPECT RESIDUAL LAKE
ENHANCED SHSN THROUGH THE OVERNIGHT AT APN/PLN...WITH MVFR
CONDITIONS /PERHAPS IFR VSBYS AT PLN?/ PERSISTING THROUGH 12Z
WEDNESDAY. MORE IMPROVEMENT IS EXPECTED AT TVC...AND EXPECIALLY
MBL WHERE A RETURN TO VFR CIGS IS EXPECTED AFTER MIDNIGHT.
AS FOR WINDS...LLWS CONCERNS ARE ENDING AT THIS HOUR AS MIXING
STRENGTHENS AT LOW LEVELS. EXPECT SOUTHEAST WINDS 5-10KTS TO VEER
SOUTHERLY 5-10KTS DURING THE DAY TODAY...BEFORE SHIFTING SOUTHWEST
AND INCREASING TO 12G18KTS TONIGHT.
&&
.MARINE...
ISSUED AT 333 AM EST TUE FEB 21 2012
SMALL CRAFTS ONGOING OVER ALL NEARSHORE ZONES...AND EXPECT THIS TO
CONTINUE THROUGH AT LEAST WEDNESDAY AS LOW PRESSURE TAKING SHAPE
OVER NORTHERN MINNESOTA TODAY SHIFTS OVER LAKE SUPERIOR TONIGHT WITH
SOUTHEAST WINDS SHIFTING SOUTHWEST TONIGHT. WINDS/WAVES SHOULD
SUBSIDE WEDNESDAY NIGHT AND THURSDAY AS WEAK AREA OF HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST. AS THE WINDS SHIFT SOUTHWEST
TONIGHT...CAN/T COMPLETELY RULE OUT A FEW LOW-END GALES ON THE
NORTHWEST LAKE MICHIGAN COAST...BUT FLOW TRAJECTORY DOES NOT FAVOR
MUCH IN THE WAY OF COASTAL CONVERGENCE ENHANCEMENT...SO EXPECT MOST
SPOTS TO GUST TO AROUND 30KTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR LHZ346-349.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR LMZ323-341-342-
344-345-346.
LS...NONE.
&&
$$
UPDATE...ARNOTT
SYNOPSIS...LAWRENCE
SHORT TERM...ARNOTT
LONG TERM....LAWRENCE
AVIATION...ARNOTT
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1027 AM EST TUE FEB 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OUT INTO THE WESTERN ATLANTIC. A SERIES OF
UPPER LEVEL DISTURBANCES WILL MOVE THROUGH THE AREA THROUGH
WEDNESDAY...FOLLOWED BY A STRONG COLD FRONT PASSAGE ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM...
LATEST RUC MODEL SHOWS THICKNESSES INCREASING LATE AFTERNOON INTO
EVENING WITH THIS ENERGY REMAINING ALOFT. IT IS PRUDENT TO BACK
OFF THE 00Z THICKNESS VALUES REGARDING TEMPERATURE FORECASTS DUE
TO THIS TIMING AND ENERGY REMAINING ALOFT. MID LEVEL CLOUDINESS HAS
ARRIVED ON CUE INTO CENTRAL NORTH CAROLINA. THE CLEARING LINE
SHOULD PASS THE WESTERN PIEDMONT BEFORE NOON... EXITING TO THE
COASTAL PLAIN AT MID AFTERNOON. HOWEVER A LOOK AT UPSTREAM
TRAJECTORIES AND MOISTURE SUGGEST SOME CLOUDINESS BEHIND THE
CLEARING LINE... BUT NOT AS EXTENSIVE AS THIS MORNING. CURRENT
FORECAST OF MID TO UPPER 50S PERHAPS A TOUCH COOL... BUT THIS WILL
DEPEND ON AFTERNOON CLOUD COVER.
LOOKING AT CURRENT TEMPERATURE PROFILES AND SURFACE TEMPERATURE
FORECASTS... WIND GUSTS TO 20 MPH SHOULD HOLD OFF UNTIL EARLY
AFTERNOON.
THE QUESTION OF POSSIBLE VERY LOW STRATUS TONIGHT WILL BE THE
PROBLEM OF THE DAY... BUT WILL DELAY ANY CHANGES UNTIL ALL THE
MORNING MODELS ARE PROCESSED. ALTHOUGH SUBTLE... DECENT LOW LEVEL
ADVECTION IN THE MODELS WITH THE STRONGER WINDS OF THE NAM ATOP
THE BOUNDARY LAYER INVERSION WITH DECOUPLING MORE REALISTIC THAN
THE GFS. TEND TO FAVOR A FORECAST OF STRATUS FORMATION BUT
UNCERTAIN OF EXTENT AT THIS TIME. REGARDLESS TEMPERATURES WILL BE
MILD COMPARED TO THIS MORNING... WITH UPPER 30S TOO LOWER 40S
COMMON.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 250 AM TUESDAY...
BY WEDNESDAY A BROAD SCALE TROUGH WILL HAVE EVOLVED OVER THE
EASTERN TWO THIRDS OF THE COUNTRY WITH SEVERAL EMBEDDED FAST
MOVING PERTURBATIONS MOVING EAST ACROSS THE AREA IN THE
PROGRESSIVE ZONAL FLOW ALOFT. ONE OF THESE VORTICITY IMPULSES OF
NOTE IS FORECAST TO REACH THE SOUTHERN AND CENTRAL APPALACHIANS
AROUND 00Z THURSDAY...AND WILL THEN TRAVERSE THE CAROLINAS BY 06Z.
DPVA AND DYNAMIC COOLING/ASCENT ACCOMPANYING THE TROUGH PASSAGE
WILL STEEPEN MID AND UPPER LEVEL LAPSE RATES ACROSS THE AREA
WEDNESDAY EVENING AND ELIMINATE THE MID LEVEL CAP...WHICH SHOULD
ALLOW THE BAND OF SHOWERS TO SURVIVE EASTWARD AS THEY MOVE OFF THE
EASTERN SLOPES AND ACROSS THE AREA. UNFAVORABLE NOCTURNAL
TURNING/BOUNDARY LAYER STABILIZATION WILL IMPACT COVERAGE
HOWEVER...AND AT THIS TIME WILL CAP POPS OFF AT LOW TO SLIGHT
CHANCE...WITH HIGHEST POPS OVER THE WESTERN PIEDMONT AND ENDING
BEFORE DAYBREAK THURSDAY.
WILL SEE FULL COMPLIMENTS OF SUN ON WEDNESDAY AS THICKNESSES SOAR TO
AROUND 1350 METERS...A GOOD 20 TO 25 METERS ABOVE NORMAL. HIGHS IN
THE LOWER 60S NORTHWEST TO UPPER 60S SOUTHEAST. MILD OVERNIGHT
LOWS OF 46 TO 51.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...
MODELS HAVE COME INTO BETTER AGREEMENT OVER THE PAST 24 HOURS WITH
RESPECT TO OUR NEXT SYSTEM THAT IS EXPECTED TO IMPACT THE REGION
DURING THE FIRST PART OF THE LONG TERM PERIOD. MODELS SHOW ANOTHER
SOUTHERN STREAM UPPER LEVEL TROUGH/LOW DIGGING INTO THE SOUTHWESTERN
UNITED STATES AND NORTHERN MEXICO TUESDAY INTO WEDNESDAY AND
EVENTUALLY EJECTING EASTWARD AND AFFECTING CENTRAL NORTH CAROLINA
THURSDAY INTO FRIDAY. DURING THE SAME TIME FRAME...A NORTHERN
STREAM TROUGH WILL AMPLIFY AS IT MOVES INTO THE CENTRAL UNITED
STATES...PROMOTING SURFACE CYCLOGENESIS ACROSS THE TENNESSEE AND
OHIO VALLEY. THE ASSOCIATED SURFACE COLD FRONT IS FORECAST TO MOVE
THROUGH CENTRAL NORTH CAROLINA FRIDAY AFTERNOON AND EVENING. ALL
OF THIS WILL RESULT IN PRECIPITATION CHANCES INCREASING LATE
THURSDAY...WITH THE BEST TIME FRAME FOR SHOWERS COINCIDING WITH
THE FRONTAL PASSAGE DURING THE DAY ON FRIDAY. AHEAD OF THE
FRONT...STRONG SOUTHWESTERLY SURFACE FLOW WILL PUSH TEMPERATURES
INTO THE UPPER 60S TO LOWER 70S ACROSS AREA ON BOTH THURSDAY AND
FRIDAY. ALSO...MOISTURE WILL POOL AHEAD OF THE APPROACHING
FRONT...WITH MAXIMUM PRECIPITABLE WATER VALUES FORECAST TO RANGE
BETWEEN ONE AND ONE AND A HALF INCHES. THIS SHOULD RESULT IN
SOME WEAK INSTABILITY OVER EASTERN NORTH CAROLINA...ALTHOUGH
CURRENT FORECAST SOUNDINGS SHOW VERY MARGINAL CAPE VALUES.
NEVERTHELESS...WILL MAINTAIN THE MENTION OF A SLIGHT CHANCE OF
THUNDER ACROSS THE COASTAL PLAIN...ESPECIALLY SINCE THE FRONTAL
PASSAGE IS EXPECTED TO OCCUR DURING A FAVORABLE TIME OF DAY.
BEHIND THE FRONT...HIGH PRESSURE WILL BUILD INTO THE REGION FOR THE
WEEKEND...WITH TEMPERATURES RETURNING TO NEAR NORMAL VALUES.
ANOTHER WARM UP SHOULD COMMENCE BY THE BEGINNING OF NEXT WEEK AS
THE HIGH IS EXPECTED TO SHIFT OFFSHORE BY MONDAY AHEAD OF OUR NEXT
SYSTEM... WHICH MAY BRING INCREASING PRECIPITATION CHANCES TO THE
AREA BY AS EARLY AS LATE MONDAY.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
AS OF 645 AM TUESDAY...
PREDOMINATELY VFR CONDITIONS THROUGH THE 24 HOUR TAF PERIOD.
HIGH PRESSURE CENTERED OVER THE REGION THIS MORNING WILL
SHIFT OFFSHORE THIS AFTERNOON. A WEAK UPPER LEVEL DISTURBANCE WILL
CROSS THE AREA ON TUESDAY. HOWEVER... BEST MOISTURE AND LIFT WILL
PASS WELL TO THE NORTH OF CENTRAL NORTH CAROLINA. THUS... DO NOT
EXPECT ANY SHOWERS TO ACCOMPANY THIS FEATURE. INSTEAD... EXPECT AN
INCREASE IN GENERALLY MID AND HIGH LEVEL CLOUD COVER...WITH LIGHT
AND VARIABLE WINDS BECOMING SOUTHWESTERLY AT 10 TO 15 MPH
SUSTAINED... GUSTING TO 20 MPH. A BRIEF PERIOD OF SUB VFR
CONDITIONS IN FOG OR STRATUS WILL BE POSSIBLE ON WEDNESDAY
MORNING...HOWEVER DUE TO LOW CONFIDENCE WILL NOT INCLUDE AT THIS
TIME.
OUTLOOK:
ANY FOG OR STRATUS WILL BURN OFF QUICKLY WEDNESDAY MORNING WITH
ANOTHER CHANCE OF SUB VFR CONDITIONS IN STRATUS OR FOG LATE
WEDNESDAY NIGHT AND THURSDAY MORNING. INCREASING RAIN CHANCES WITH
ADVERSE AVIATION CONDITIONS ARE EXPECTED RAIN LATE THURSDAY NIGHT
AND INTO FRIDAY AS THE A WAVY FRONTAL ZONE MOVES THROUGH THE AREA.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CBL
LONG TERM...KRR
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS ALBANY NY
1258 PM EST TUE FEB 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT EASTWARD AND OFFSHORE TODAY WITH CLOUDS ON
THE INCREASE. A WARM FRONT WILL MOVE ACROSS THE REGION TONIGHT
ACCOMPANIED BY RAIN AND SNOW SHOWERS. THE WEATHER WILL REMAIN
UNSETTLED FOR THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
CI/CS CLOUD CANOPY CONTINUES TO THICKEN AND LOWER AS UPPER LOW
NEAR DETROIT LIFTS NORTHEAST. REGIONAL RADARS SHOW SHOWER ACTIVITY
HAS MOVED INTO EXTREME WESTERN NY AND WESTERN PA. UPSTREAM METARS
SHOW A MIXTURE OF RAIN/SNOW AS THIS WILL BECOME OUR ISSUE LATER
THIS EVENING. AS FOR ARRIVAL TIMING...PER THE HRRR AND
EXTRAPOLATING RADAR TRENDS...SEEMS OUR WESTERN AREAS COULD SEE
PRECIP AS EARLY AS 4 PM EST AND INTO THE HUDSON RIVER VALLEY
AROUND 6 PM. SO HAVE MADE SLIGHT ADJUSTMENTS TO THE POPS/WX GRIDS.
OTHERWISE...TEMPERATURES LOOK ON TRACK AND LITTLE CHANGES NEEDED
AT THIS TIME.
THIS PIECE OF ENERGY WILL LOSE ITS IDENTITY TONIGHT. HOWEVER MORE
ENERGY MOVING THROUGH THE LONGWAVE TROUGH WILL BE ON ITS HEALS.
WILL HAVE WEAK FRONTAL BOUNDARY...OCCLUDING WARM FRONT MOVE ACROSS
THE REGION TONIGHT. THE BEST CHANCES FOR SHOWERS WILL BE ACROSS
THE SOUTHERN ADIRONDACKS WHERE THE BETTER UPPER SUPPORT WILL BE.
IT WILL BE COLD ENOUGH FOR MAINLY SNOW ACROSS THE SOUTHERN
ADIRONDACKS WITH UP TO A COUPLE INCHES OF SNOW EXPECTED.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
MODEL GUIDANCE HAS NOT BEEN CONSISTENT HANDLING THE NEXT SIGNIFICANT
PIECE OF ENERGY MOVING THROUGH THE LONGWAVE PATTERN AND HOW AND
WHERE THE LOW PRESSURE SYSTEM ASSOCIATED WITH IT DEVELOPS. AS FOR
WEDNESDAY AND WEDNESDAY NIGHT...A SURFACE LOW WILL MOVE GRADUALLY
EASTWARD ACROSS ONTARIO AND QUEBEC WHILE THE UPPER TROUGH FLATTENS
OVER OUR REGION. PIECES OF ENERGY WILL MOVE THROUGH THIS FAST FLOW
KEEPING THE THREAT FOR PRECIPITATION IN THE FORECAST. MORE
ORGANIZED/WIDESPREAD PRECIPITATION WILL BEGIN TO MOVE INTO THE
REGION THURSDAY AS A LOW PRESSURE SYSTEM APPROACHES.
EXPECTING EVEN MILDER TEMPERATURES WEDNESDAY WITH SOUTHWESTERLY FLOW
ACROSS THE AREA...SHOULD REACH 50 DEGREES IN THE CAPITAL DISTRICT.
NOT QUITE AS MILD THURSDAY BUT STILL ABOVE NORMAL BY AROUND 10
DEGREES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE MEDIUM RANGE GUIDANCE CONTINUE TO FORECAST AN ACTIVE WEATHER
PATTERN AT THE END OF THE WEEK...AND THE BEGINNING OF THE WEEKEND.
THERE STILL IS QUITE A BIT OF UNCERTAINTY ON THE
TIMING...EVOLUTION...AND IMPACT OF A SYSTEM FRIDAY INTO
SATURDAY...AND WE ARE LEANING MORE TOWARDS AN HPC/GFS/GLOBAL
ENSEMBLE MEAN SCENARIO INTO THE FIRST HALF OF THE WEEKEND...AND THEN
FOLLOWED CLOSER TO HPC THEREAFTER.
THURSDAY NIGHT...A SFC CYCLONE APPROACHES THE FORECAST AREA FROM THE
GREAT LAKES REGION IN THE W/SW H500 FLOW ALOFT. THE WARM FRONT TO
THE CYCLONE LIFTS NORTHWARD FROM THE OHIO VALLEY. THE ISENTROPIC
LIFT STRENGTHENS FOR A PERIOD OF WET SNOW AND RAIN. THE WET SNOW
WILL LIKELY BE CONFINED TO LOCATIONS NORTH OF THE CAPITAL
REGION...AND OVER THE MOUNTAINS. LOWS WILL GENERALLY BE IN THE
LOWER TO M30S. AS THE WARM FRONT MOVES THROUGH...H850 TEMPS RISE TO
0C TO +6C BY 12Z/FRI.
FRIDAY...THE NAM IS THE FASTEST DEEPENING AND INTENSIFYING THE
CYCLONE TO 983 HPA OVER SRN QUEBEC BY 12Z. THE CAN GGEM/GFS ARE IN
PRETTY GOOD AGREEMENT THE LOW WILL BE NEAR WRN NY AND THE ERN GREAT
LAKES REGION AT THIS TIME...WHILE THE ECMWF IS MUCH SLOWER WITH THE
CYCLONE OVER THE OHIO VALLEY. THE 00Z GLOBAL ENSEMBLE MEAN IS A
COMPROMISE BTWN THE NAM AND THE GFS/CAN GGEM. HPC/S PLACEMENT OF A
992 HPA CYCLONE NEAR NIAGARA FALLS FAVORS THE GFS. THE NRN AND SRN
STREAMS CONTINUE TO SHOW SIGNS OF PHASING NEAR THE NORTHEAST DURING
THE DAY. A BROAD UPPER LEVEL TROUGH IS CARVED OUT OVER THE CENTRAL
PLAINS INTO THE MS RIVER VALLEY WITH THE NRN AND SRN STREAMS PHASING
POTENTIALLY ALONG OR JUST WEST OF THE APPALACHIAN MTNS. THE SURFACE
LOW INTENSIFIES AND DEEPENS...AS IT MOVES ACROSS NY AND NEW ENGLAND
INTO SE QUEBEC. THE ECMWF IS STUBBORNLY SLOWER AND MUCH MORE INTENSE
WITH THE CYCLONE DEVELOPMENT NEAR THE DELMARVA REGION AT 00Z/SAT.
THE GFS HAS A DRY SLOT OVER THE REGION HEADING INTO THE OVERNIGHT
PERIOD. MOST OF THE REGION WILL BE IN A WARM SECTOR WITH PERIODS OF
RAIN. THE QUESTION WILL BE HOW FAST THE COLD AIR MOVES BACK IN FROM
THE NORTH AND WEST WITH THE CYCLONE LIFTING NORTH AND EAST OF THE
REGION. AGAIN...LEANING TOWARDS HPC HERE WITH THE COLDER AIR MOVING
IN TOWARDS NIGHTFALL. HIGHS WILL BE BALMY ON FRIDAY...WITH U40S TO
M50S IN THE VALLEYS...AND LOWER TO M40S OVER THE MTNS.
FRI NIGHT...THE ECMWF HAS AN IMPRESSIVE ISALLOBARIC COUPLET
IMPACTING THE FCST AREA WITH THE STORM DEEPENING AND INTENSIFYING TO
967 HPA JUST NORTHEAST OF MONTREAL BY 12Z/SAT. THE GFS/HPC HAVE THE
DEEP STORM OF ABOUT 980 HPA OVER NRN ME/NEW BRUNSWICK. THE GFS SFC
ISALLOBARIC COUPLET ISN/T ANYWHERE NEAR AS STRONG AS THE ECMWF.
STRONG COLD AIR ADVECTION IMPACTS THE REGION WITH H850 TEMPS FALLING
BACK TO ABOUT -10C. IT WILL BE WINDY...BUT HOW WINDY IS THE
QUESTION AT THIS POINT BASED ON THE MODEL DISCREPANCIES. THE H850
WINDS FROM THE NW ARE ONLY 35-40 KTS BY 12Z/SAT ON THE GFS. WE WILL
CONTINUE TO MONITOR HOWS THINGS EVOLVE OVER THE NEXT FEW DAYS. THE
ECMWF SCENARIO WOULD BE THE WORST CASE SCENARIO WITH A POTENTIALLY
HIGH WIND EVENT. OUR CONFIDENCE IS NOT HIGH ENOUGH YET TO PLACE
THIS IN THE HWO.
SATURDAY...COLD AND WINDY CONDITIONS PREVAIL WITH NORTHWEST FLOW
ALOFT. A SERIES OF DISTURBANCES WILL BE ROTATING AROUND THE STACKED
LOW OVER THE CANADIAN MARITIMES. WE KEPT A CHANCE OF SNOW SHOWERS
IN NORTH AND WEST OF THE CAPITAL DISTRICT...AND A SLIGHT CHC SOUTH
AND EAST. MAX TEMPS WILL BE CLOSER TO SEASONABLE READINGS.
SATURDAY NIGHT...A SECOND COLD FRONT OR SFC TROUGH MOVES THROUGH
WITH H850 TEMPS FALLING TO -12C TO -15C OVER THE REGION. THIS
BOUNDARY HAS LESS MOISTURE TO WORK WITH...AND THE BEST CHC OF SNOW
SHOWERS WILL BE DOWNWIND OF LAKE ONTARIO...AND PREDOMINANTLY WEST OF
THE HUDSON RIVER VALLEY. LOWS WILL BE IN THE UPPER TEENS TO LOWER
20S IN THE VALLEYS...AND SINGLE DIGITS TO MID TEENS OVER THE MTNS.
SUNDAY TO MONDAY...FOLLOWED CLOSE TO HPC WITH HIGH PRESSURE BRIEFLY
BUILDING IN FROM SOUTH OF JAMES BAY TO CLOSE THE WEEKEND. ANY LAKE
EFFECT SNOW SHOWERS OR FLURRIES WILL END. THE NEXT CYCLONE
APPROACHES FROM THE LOWER GREAT LAKES REGION TO OPEN THE WEEK. IT
LOOKS TO PASS NORTH AND WEST OF UPSTATE NY...WITH A SLIGHT TO LOW
CHC OF RAIN AND SNOW SHOWERS. TEMPS MODERATE SLIGHTLY ABOVE NORMAL.
OVERALL...TEMPS WILL STILL RUN ABOVE NORMAL...WITH PRECIPITATION
AMOUNTS IN THE NORMAL RANGE DEPENDING ON THE FRIDAY SYSTEM.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
GUSTY WINDS OUT OF THE SOUTH THIS AFTERNOON AND EARLY
EVENING...WILL SUBSIDE...ONLY TO HAVE SNOW SHOWERS MOVE IN FROM
THE GREAT LAKES REGION AS A WARM FRONT MOVES ACROSS THE AREA
OVERNIGHT.
AS HIGH PRESSURE CONTINUES TO MOVE OFF SHORE AND LOW PRESSURE
OVER THE NORTHERN GREAT LAKES REGION APPROACHES...A TIGHT
PRESSURE GRADIENT WILL CONTINUE TO DEVELOP OVER THE NE...LEADING
TO WINDS GUSTING TO 15-25 KTS AT ALL TERMINALS THIS AFTERNOON. A
WARM FRONT ASSOCIATED WITH THE LOW PRESSURE WILL MAKE ITS WAY
NORTHEASTWARD...INCREASING AND LOWERING CLOUD COVER. VFR CIGS AND
VSBYS EXPECTED THROUGH AT LEAST 03Z...BUT UPSTREAM OBS INDICATE
MVFR CIGS POSSIBLE WITH -SHSN OVERNIGHT. MODELS INDICATE PRECIP
STARTING AROUND 00Z TONIGHT...BUT DRY AIR OVERHEAD WILL TAKE TIME
TO SATURATE. BEST CHC FOR -SHSN WILL BE KALB BRIEFLY AND KGFL.
HAVE THEREFORE INTRODUCED MVFR CIGS AT KALB AND KGFL AROUND
03Z...BUT KALB IMPROVING TO VFR SHORTLY AFTER MIDNIGHT/05Z. BEST
ISENTROPIC LIFT NEAR KGFL...HENCE LONGER DURATION -SHSN AND MVFR
VSBYS. KGFL CONDITIONS EXPECTED TO IMPROVE WEDNESDAY MORNING.
WINDS WILL SUBSIDE OVERNIGHT TO LESS THAN 10KTS OUT OF THE
SOUTH...BUT WINDS ALOFT WILL REMAIN 30-40 KTS...LEADING TO
POSSIBLE WIND SHEAR. HAVE INDICATED LLWS AT KGFL DUE TO BEST
CONFIDENCE...BUT IT MAY BE CLOSE AT OTHER TERMINALS THROUGH
MIDNIGHT. SFC WIND WILL SHIFT SW SOMETIME WEDNESDAY MORNING.
OUTLOOK....
WED...VFR...SLIGHT CHC -SHRA.
WED NIGHT...VFR/MVFR...CHC -SHRA KPOU...SLGT CHC -SHRA/-SHSN NORTH.
THU...VFR...CHC PM -SHRAS.
THU NIGHT...MVFR/VFR. CHC -RA.
FRI...MVFR CIGS/VSBYS...RA LIKELY. BECOMING WINDY.
FRI NGT-SUN...VFR...SLIGHT CHC -SHSN. WINDY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THIS WEEK. HIGH PRESSURE WILL MOVE
OFFSHORE TODAY AND THE WEATHER WILL BECOME UNSETTLED FOR THE REST OF
THE WEEK. THE BEST CHANCES FOR WIDESPREAD PRECIPITATION MAINLY IN
THE FORM OF RAIN WILL BE THURSDAY NIGHT AND FRIDAY WITH A TRANSITION
TO PRIMARILY SNOW AS COLDER AIR MOVES IN FRIDAY NIGHT. THE POTENTIAL
FOR FLOODING IS GENERALLY BELOW NORMAL DUE TO BELOW NORMAL SNOWPACK
AND RIVER ICE. PLEASE REFER TO OUR WINTER/SPRING FLOOD POTENTIAL
OUTLOOK (ALBESFALY) ISSUED ON FEBRUARY 16TH FOR DETAILS. NEXT
ISSUANCE OF THIS PRODUCT OS SCHEDULED FOR MARCH 1ST.
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...
LEAST SNOWIEST DEC-JAN-FEB FOR ALBANY NY
YEARS OF RECORD: 1884-2012
1) 8.8 INCHES 2011-12 (THROUGH 2/20)
2) 10.9 INCHES 1936-37
3) 11.7 INCHES 1912-13
4) 13.8 INCHES 1911-12
5) 14.2 INCHES 1988-89
6) 16.3 INCHES 1931-32
7) 16.6 INCHES 1979-80
8) 17.0 INCHES 1954-55
9) 17.1 INCHES 1918-19
17.1 INCHES 1889-90
10) 17.3 INCHES 1910-11
LEAST SNOWIEST SEASONS FOR ALBANY NY
YEARS OF RECORD: 1884-2012
1) 13.8 INCHES 1912-13
2) 14.1 INCHES 2011-12 (THROUGH FEB 20TH)
3) 19.0 INCHES 1988-89
4) 24.8 INCHES 1929-30
5) 26.7 INCHES 1918-19
6) 27.4 INCHES 1979-80
7) 28.1 INCHES 1889-90
8) 28.4 INCHES 1936-37
9) 28.7 INCHES 1990-91
28.7 INCHES 1914-15
11) 28.9 INCHES 1896-97
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/BGM/JPV
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...KGM
HYDROLOGY...IAA
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1229 PM EST TUE FEB 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL SHIFT EASTWARD AND OFFSHORE TODAY WITH CLOUDS ON
THE INCREASE. A WARM FRONT WILL MOVE ACROSS THE REGION TONIGHT
ACCOMPANIED BY RAIN AND SNOW SHOWERS. THE WEATHER WILL REMAIN
UNSETTLED FOR THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
CI/CS CLOUD CANOPY CONTINUES TO THICKEN AND LOWER AS UPPER LOW
NEAR DETROIT LIFTS NORTHEAST. REGIONAL RADARS SHOW SHOWER ACTIVITY
HAS MOVED INTO EXTREME WESTERN NY AND WESTERN PA. UPSTREAM METARS
SHOW A MIXTURE OF RAIN/SNOW AS THIS WILL BECOME OUR ISSUE LATER
THIS EVENING. AS FOR ARRIVAL TIMING...PER THE HRRR AND
EXTRAPOLATING RADAR TRENDS...SEEMS OUR WESTERN AREAS COULD SEE
PRECIP AS EARLY AS 4 PM EST AND INTO THE HUDSON RIVER VALLEY
AROUND 6 PM. SO HAVE MADE SLIGHT ADJUSTMENTS TO THE POPS/WX GRIDS.
OTHERWISE...TEMPERATURES LOOK ON TRACK AND LITTLE CHANGES NEEDED
AT THIS TIME.
THIS PIECE OF ENERGY WILL LOSE ITS IDENTITY TONIGHT. HOWEVER MORE
ENERGY MOVING THROUGH THE LONGWAVE TROUGH WILL BE ON ITS HEALS.
WILL HAVE WEAK FRONTAL BOUNDARY...OCCLUDING WARM FRONT MOVE ACROSS
THE REGION TONIGHT. THE BEST CHANCES FOR SHOWERS WILL BE ACROSS
THE SOUTHERN ADIRONDACKS WHERE THE BETTER UPPER SUPPORT WILL BE.
IT WILL BE COLD ENOUGH FOR MAINLY SNOW ACROSS THE SOUTHERN
ADIRONDACKS WITH UP TO A COUPLE INCHES OF SNOW EXPECTED.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
MODEL GUIDANCE HAS NOT BEEN CONSISTENT HANDLING THE NEXT SIGNIFICANT
PIECE OF ENERGY MOVING THROUGH THE LONGWAVE PATTERN AND HOW AND
WHERE THE LOW PRESSURE SYSTEM ASSOCIATED WITH IT DEVELOPS. AS FOR
WEDNESDAY AND WEDNESDAY NIGHT...A SURFACE LOW WILL MOVE GRADUALLY
EASTWARD ACROSS ONTARIO AND QUEBEC WHILE THE UPPER TROUGH FLATTENS
OVER OUR REGION. PIECES OF ENERGY WILL MOVE THROUGH THIS FAST FLOW
KEEPING THE THREAT FOR PRECIPITATION IN THE FORECAST. MORE
ORGANIZED/WIDESPREAD PRECIPITATION WILL BEGIN TO MOVE INTO THE
REGION THURSDAY AS A LOW PRESSURE SYSTEM APPROACHES.
EXPECTING EVEN MILDER TEMPERATURES WEDNESDAY WITH SOUTHWESTERLY FLOW
ACROSS THE AREA...SHOULD REACH 50 DEGREES IN THE CAPITAL DISTRICT.
NOT QUITE AS MILD THURSDAY BUT STILL ABOVE NORMAL BY AROUND 10
DEGREES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE MEDIUM RANGE GUIDANCE CONTINUE TO FORECAST AN ACTIVE WEATHER
PATTERN AT THE END OF THE WEEK...AND THE BEGINNING OF THE WEEKEND.
THERE STILL IS QUITE A BIT OF UNCERTAINTY ON THE
TIMING...EVOLUTION...AND IMPACT OF A SYSTEM FRIDAY INTO
SATURDAY...AND WE ARE LEANING MORE TOWARDS AN HPC/GFS/GLOBAL
ENSEMBLE MEAN SCENARIO INTO THE FIRST HALF OF THE WEEKEND...AND THEN
FOLLOWED CLOSER TO HPC THEREAFTER.
THURSDAY NIGHT...A SFC CYCLONE APPROACHES THE FORECAST AREA FROM THE
GREAT LAKES REGION IN THE W/SW H500 FLOW ALOFT. THE WARM FRONT TO
THE CYCLONE LIFTS NORTHWARD FROM THE OHIO VALLEY. THE ISENTROPIC
LIFT STRENGTHENS FOR A PERIOD OF WET SNOW AND RAIN. THE WET SNOW
WILL LIKELY BE CONFINED TO LOCATIONS NORTH OF THE CAPITAL
REGION...AND OVER THE MOUNTAINS. LOWS WILL GENERALLY BE IN THE
LOWER TO M30S. AS THE WARM FRONT MOVES THROUGH...H850 TEMPS RISE TO
0C TO +6C BY 12Z/FRI.
FRIDAY...THE NAM IS THE FASTEST DEEPENING AND INTENSIFYING THE
CYCLONE TO 983 HPA OVER SRN QUEBEC BY 12Z. THE CAN GGEM/GFS ARE IN
PRETTY GOOD AGREEMENT THE LOW WILL BE NEAR WRN NY AND THE ERN GREAT
LAKES REGION AT THIS TIME...WHILE THE ECMWF IS MUCH SLOWER WITH THE
CYCLONE OVER THE OHIO VALLEY. THE 00Z GLOBAL ENSEMBLE MEAN IS A
COMPROMISE BTWN THE NAM AND THE GFS/CAN GGEM. HPC/S PLACEMENT OF A
992 HPA CYCLONE NEAR NIAGARA FALLS FAVORS THE GFS. THE NRN AND SRN
STREAMS CONTINUE TO SHOW SIGNS OF PHASING NEAR THE NORTHEAST DURING
THE DAY. A BROAD UPPER LEVEL TROUGH IS CARVED OUT OVER THE CENTRAL
PLAINS INTO THE MS RIVER VALLEY WITH THE NRN AND SRN STREAMS PHASING
POTENTIALLY ALONG OR JUST WEST OF THE APPALACHIAN MTNS. THE SURFACE
LOW INTENSIFIES AND DEEPENS...AS IT MOVES ACROSS NY AND NEW ENGLAND
INTO SE QUEBEC. THE ECMWF IS STUBBORNLY SLOWER AND MUCH MORE INTENSE
WITH THE CYCLONE DEVELOPMENT NEAR THE DELMARVA REGION AT 00Z/SAT.
THE GFS HAS A DRY SLOT OVER THE REGION HEADING INTO THE OVERNIGHT
PERIOD. MOST OF THE REGION WILL BE IN A WARM SECTOR WITH PERIODS OF
RAIN. THE QUESTION WILL BE HOW FAST THE COLD AIR MOVES BACK IN FROM
THE NORTH AND WEST WITH THE CYCLONE LIFTING NORTH AND EAST OF THE
REGION. AGAIN...LEANING TOWARDS HPC HERE WITH THE COLDER AIR MOVING
IN TOWARDS NIGHTFALL. HIGHS WILL BE BALMY ON FRIDAY...WITH U40S TO
M50S IN THE VALLEYS...AND LOWER TO M40S OVER THE MTNS.
FRI NIGHT...THE ECMWF HAS AN IMPRESSIVE ISALLOBARIC COUPLET
IMPACTING THE FCST AREA WITH THE STORM DEEPENING AND INTENSIFYING TO
967 HPA JUST NORTHEAST OF MONTREAL BY 12Z/SAT. THE GFS/HPC HAVE THE
DEEP STORM OF ABOUT 980 HPA OVER NRN ME/NEW BRUNSWICK. THE GFS SFC
ISALLOBARIC COUPLET ISN/T ANYWHERE NEAR AS STRONG AS THE ECMWF.
STRONG COLD AIR ADVECTION IMPACTS THE REGION WITH H850 TEMPS FALLING
BACK TO ABOUT -10C. IT WILL BE WINDY...BUT HOW WINDY IS THE
QUESTION AT THIS POINT BASED ON THE MODEL DISCREPANCIES. THE H850
WINDS FROM THE NW ARE ONLY 35-40 KTS BY 12Z/SAT ON THE GFS. WE WILL
CONTINUE TO MONITOR HOWS THINGS EVOLVE OVER THE NEXT FEW DAYS. THE
ECMWF SCENARIO WOULD BE THE WORST CASE SCENARIO WITH A POTENTIALLY
HIGH WIND EVENT. OUR CONFIDENCE IS NOT HIGH ENOUGH YET TO PLACE
THIS IN THE HWO.
SATURDAY...COLD AND WINDY CONDITIONS PREVAIL WITH NORTHWEST FLOW
ALOFT. A SERIES OF DISTURBANCES WILL BE ROTATING AROUND THE STACKED
LOW OVER THE CANADIAN MARITIMES. WE KEPT A CHANCE OF SNOW SHOWERS
IN NORTH AND WEST OF THE CAPITAL DISTRICT...AND A SLIGHT CHC SOUTH
AND EAST. MAX TEMPS WILL BE CLOSER TO SEASONABLE READINGS.
SATURDAY NIGHT...A SECOND COLD FRONT OR SFC TROUGH MOVES THROUGH
WITH H850 TEMPS FALLING TO -12C TO -15C OVER THE REGION. THIS
BOUNDARY HAS LESS MOISTURE TO WORK WITH...AND THE BEST CHC OF SNOW
SHOWERS WILL BE DOWNWIND OF LAKE ONTARIO...AND PREDOMINANTLY WEST OF
THE HUDSON RIVER VALLEY. LOWS WILL BE IN THE UPPER TEENS TO LOWER
20S IN THE VALLEYS...AND SINGLE DIGITS TO MID TEENS OVER THE MTNS.
SUNDAY TO MONDAY...FOLLOWED CLOSE TO HPC WITH HIGH PRESSURE BRIEFLY
BUILDING IN FROM SOUTH OF JAMES BAY TO CLOSE THE WEEKEND. ANY LAKE
EFFECT SNOW SHOWERS OR FLURRIES WILL END. THE NEXT CYCLONE
APPROACHES FROM THE LOWER GREAT LAKES REGION TO OPEN THE WEEK. IT
LOOKS TO PASS NORTH AND WEST OF UPSTATE NY...WITH A SLIGHT TO LOW
CHC OF RAIN AND SNOW SHOWERS. TEMPS MODERATE SLIGHTLY ABOVE NORMAL.
OVERALL...TEMPS WILL STILL RUN ABOVE NORMAL...WITH PRECIPITATION
AMOUNTS IN THE NORMAL RANGE DEPENDING ON THE FRIDAY SYSTEM.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL PREVAIL THE NEXT 12-18 HOURS WITH HIGH PRESSURE
IN CONTROL INTO THE AFTERNOON. A WARM FRONT WILL APPROACH FROM THE
OHIO VALLEY. THIS BOUNDARY WILL BRING AN INCREASE OF CLOUDS...A
CHANCE OF RAIN OR SNOW SHOWERS...AND LOW LEVEL WIND SHEAR CONDITIONS
AFTER 23Z FOR NORTH OF KALB.
HIGH CLOUDS WILL INCREASE WITH THE SFC HIGH MOVING OFF THE NEW
ENGLAND COAST INTO THE AFTERNOON. THE CLOUDS WILL CONTINUE TO
THICKEN AND LOWER INTO THE EARLY EVENING WITH BASES LOWERING TO 5-7
KFT AGL AFTER 00Z/WED. THE WINDS AT THE 2 KFT AGL WILL INCREASE TO
35-40 KTS. THE SFC WINDS WINDS MAY DECREASE TO 5 KTS OR LESS AFTER
DARK ESPECIALLY AT KGFL. A LLWS GROUP WAS ADDED AT KGFL WHERE OUR
CONFIDENCE WAS GREATEST. KPOU IS MARGINALLY CLOSE TO LLWS
CONDITIONS...AND MAY BE NECESSARY WITH LATER TAF ISSUANCES...IF
CONFIDENCE INCREASES.
SOME SCT SNOW SHOWERS WILL DEVELOP AHEAD OF THE WARM FRONT...AS CIGS
AND VSBYS WILL LOWER TO MVFR LEVELS ESPECIALLY NORTH OF KALB. FOR
NOW...WE CONTINUED LOW VFR CIGS FROM KALB SOUTH. WE ALSO INCLUDED
VCSH GROUPS FOR KPOU AND KALB AT 00Z AND 03Z RESPECTIVELY.
THE WINDS WILL BE SOUTHERLY AT 7-12 KTS IN THE LATE MORNING THRU THE
AFTERNOON...WITH A FEW GUSTS CLOSE TO 20 KTS AT KALB. THE SFC WINDS
WILL LIGHTEN TO 10 KTS OR LESS AFTER 00Z/WED.
OUTLOOK....
WED...VFR. SLIGHT CHC -SHRA.
WED NIGHT...VFR/MVFR...CHC -SHRA KPOU...SLGT CHC -SHRA/-SHSN NORTH.
THU...VFR...CHC PM -SHRAS.
THU NIGHT...MVFR/VFR. CHC -RA.
FRI...MVFR CIGS/VSBYS. RA LIKELY. BECOMING WINDY.
FRI NGT-SAT...VFR. SLIGHT CHC -SHSN. WINDY.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THIS WEEK. HIGH PRESSURE WILL MOVE
OFFSHORE TODAY AND THE WEATHER WILL BECOME UNSETTLED FOR THE REST OF
THE WEEK. THE BEST CHANCES FOR WIDESPREAD PRECIPITATION MAINLY IN
THE FORM OF RAIN WILL BE THURSDAY NIGHT AND FRIDAY WITH A TRANSITION
TO PRIMARILY SNOW AS COLDER AIR MOVES IN FRIDAY NIGHT. THE POTENTIAL
FOR FLOODING IS GENERALLY BELOW NORMAL DUE TO BELOW NORMAL SNOWPACK
AND RIVER ICE. PLEASE REFER TO OUR WINTER/SPRING FLOOD POTENTIAL
OUTLOOK (ALBESFALY) ISSUED ON FEBRUARY 16TH FOR DETAILS. NEXT
ISSUANCE OF THIS PRODUCT OS SCHEDULED FOR MARCH 1ST.
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...
LEAST SNOWIEST DEC-JAN-FEB FOR ALBANY NY
YEARS OF RECORD: 1884-2012
1) 8.8 INCHES 2011-12 (THROUGH 2/20)
2) 10.9 INCHES 1936-37
3) 11.7 INCHES 1912-13
4) 13.8 INCHES 1911-12
5) 14.2 INCHES 1988-89
6) 16.3 INCHES 1931-32
7) 16.6 INCHES 1979-80
8) 17.0 INCHES 1954-55
9) 17.1 INCHES 1918-19
17.1 INCHES 1889-90
10) 17.3 INCHES 1910-11
LEAST SNOWIEST SEASONS FOR ALBANY NY
YEARS OF RECORD: 1884-2012
1) 13.8 INCHES 1912-13
2) 14.1 INCHES 2011-12 (THROUGH FEB 20TH)
3) 19.0 INCHES 1988-89
4) 24.8 INCHES 1929-30
5) 26.7 INCHES 1918-19
6) 27.4 INCHES 1979-80
7) 28.1 INCHES 1889-90
8) 28.4 INCHES 1936-37
9) 28.7 INCHES 1990-91
28.7 INCHES 1914-15
11) 28.9 INCHES 1896-97
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/BGM/JPV
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...WASULA
HYDROLOGY...IAA
CLIMATE...IAA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1121 AM CST TUE FEB 21 2012
.DISCUSSION...
ISSUED 1010 AM CST TUE FEB 21 2012
COLD FRONT CONTINUES TO APPROACH THE CWA LATE THIS MORNING...
CURRENTLY ANALYZED FROM ABOUT KANSAS CITY NORTHEAST INTO CENTRAL
WISCONSIN. LARGE AREA OF STRATOCUMULUS AHEAD OF THE FRONT SHOWED A
FEW HOLES EARLIER WHICH HAVE LARGELY FILLED...BUT TRAILING EDGE OF
THE CLOUD DECK JUST STARTING TO CROSS THE MISSISSIPPI RIVER AROUND
QUINCY. LAYER HUMIDITY PLOTS FROM RUC AND NAM SHOWING THIS BACK
EDGE OF THE LOW CLOUDS SHOULD BE ADVANCING NORTHEAST ACROSS THE
CWA THROUGH MID AFTERNOON...HOWEVER SOME MID AND HIGH CLOUDS MOVING
IN AT THE SAME TIME WILL FILTER THE SUNSHINE THAT WOULD OTHERWISE
HAVE OCCURRED.
HAVE SENT SOME MINOR TWEAKS TO THE ZONES/GRIDS...MAINLY TO REMOVE
THE RAIN CHANCES TODAY AND UPDATE THE HOURLY SKY/TEMPERATURE
TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 1120 AM CST TUE FEB 21 2012
MAIN CONCERN IS WITH CEILINGS EARLY THIS AFTERNOON. MVFR CEILINGS
COVERING MOST OF THE AREA LATE THIS MORNING...WITH SOME POCKETS
BELOW 1000 FEET ESPECIALLY FROM KBMI NORTHWEST. BACK EDGE OF THE
LOW CLOUDS WAS ROUGHLY FROM KMUT-KMQB-KPPQ AT 17Z. CLOUD EDGE IS
STEADILY MOVING EASTWARD...AND AWIPS TIME-OF-ARRIVAL TOOL HAS IT
REACHING KCMI KCMI TOWARD 21Z. GUSTY SOUTHWEST WINDS TO BECOME
MORE WESTERLY AS A COLD FRONT ADVANCES...WITH SOME GUSTS TO AROUND
25 KNOTS THROUGH SUNSET. VFR CONDITIONS EXPECTED THE REMAINDER OF
THE PERIOD...ONCE THESE LOW CLOUDS EXIT. CEILINGS MAINLY AROUND
6000 FEET EXPECTED OVERNIGHT AND EARLY WEDNESDAY...ALTHOUGH MODEL
CROSS SECTIONS HINT AT A COUPLE HOURS AROUND 12Z WHERE THE
CEILINGS MAY BREAK FOR A TIME.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 239 AM CST TUE FEB 21 2012
SHORT TERM...TODAY THROUGH THURSDAY
VIGOROUS UPPER-LEVEL LOW CURRENTLY OVER MISSOURI WILL TRACK
EASTWARD ACROSS CENTRAL ILLINOIS THIS MORNING. BULK OF SHOWER
ACTIVITY ASSOCIATED WITH THIS FEATURE WILL LIFT N/NE OF THE AREA
BY 12Z...HOWEVER RADAR MOSAIC IS INDICATING SCATTERED LIGHT
SHOWERS DEVELOPING IMMEDIATELY BENEATH THE LOW...SO THINK RAIN
CHANCES ARE STILL WARRANTED THROUGH MIDDAY. ONCE THE LOW SHIFTS
FURTHER EAST...SYNOPTIC SUBSIDENCE ON ITS BACK SIDE WILL RESULT IN
CLEARING SKIES FROM WEST TO EAST DURING THE AFTERNOON. MID/HIGH
CLOUDS CURRENTLY UPSTREAM OVER NEBRASKA WILL STREAM EASTWARD INTO
THE AREA TOWARD EVENING...SO SUNSHINE WILL DEFINITELY BE LIMITED
TODAY. HIGH TEMPS WILL ONCE AGAIN BE ON THE MILD SIDE...WITH
READINGS TOPPING OUT IN THE MIDDLE TO UPPER 40S IN MOST LOCATIONS.
WEAK SHORT-WAVE WILL SKIRT THROUGH THE MIDWEST ON WEDNESDAY...HOWEVER
LACK OF DEEP ATMOSPHERIC MOISTURE WILL PREVENT ANY PRECIP FROM
DEVELOPING. MOSTLY CLOUDY AND DRY CONDITIONS WILL PREVAIL...WITH
HIGHS REACHING THE LOWER TO MIDDLE 50S THANKS TO A SUSTAINED
SOUTHERLY FLOW.
STRONGER WAVE CURRENTLY OVER THE GULF OF ALASKA WILL DROP
SOUTHEASTWARD THROUGH THE NORTHERN ROCKIES INTO THE PLAINS ON
THURSDAY...PUSHING A COLD FRONT INTO CENTRAL ILLINOIS LATE IN THE
DAY. WITH STRONGER UPPER DYNAMICS AND SOMEWHAT MORE FAVORABLE
MOISTURE PROFILES IN PLACE...THINK SCATTERED SHOWERS WILL DEVELOP
AHEAD OF THE FRONT. HAVE THEREFORE INCLUDED LOW CHANCE POPS ACROSS
THE BOARD ON THURSDAY...THEN ACROSS THE E/SE KILX CWA THURSDAY
NIGHT AS THE FRONT PUSHES FURTHER EAST.
LONG TERM...FRIDAY THROUGH MONDAY
DEEP TROUGH WILL DIG ACROSS THE MIDWEST/GREAT LAKES ON
FRIDAY/SATURDAY...RESULTING IN A TEMPORARY COOLING TREND. WITH
CYCLONIC FLOW AND VERY COLD 500MB TEMPS IN PLACE...COULD
POTENTIALLY SEE A FEW SCATTERED RAIN/SNOW SHOWERS ON
FRIDAY...HOWEVER THINK AREAL COVERAGE WILL BE MINIMAL DUE TO LACK
OF STRONG FOCUSING MECHANISM. WILL THEREFORE ONLY MENTION SLIGHT
CHANCE POPS AT THIS TIME. MAIN STORY WILL BE THE COOLER
TEMPS...WITH HIGHS ONLY REACHING THE UPPER 30S/LOWER 40S.
MODELS CONTINUE TO STRUGGLE WITH THE RAPIDLY EVOLVING UPPER
PATTERN LATE IN THE WEEKEND...WITH THE 00Z 21 FEB MODELS SHOWING
DRASTICALLY DIFFERENT SOLUTIONS. ECMWF/CANADIAN BOTH DIG A
PROMINENT TROUGH OVER THE WESTERN CONUS BY SUNDAY...RESULTING IN
RIDGING DOWNSTREAM OVER THE MIDWEST. ASSOCIATED 993MB SURFACE LOW
IS POSITIONED IN EASTERN COLORADO BY 00Z MON. MEANWHILE...THE GFS
IS MUCH WEAKER/MORE PROGRESSIVE WITH THE TROUGH...TRACKING IT
EASTWARD INTO THE MIDWEST MUCH FASTER. ITS SURFACE LOW PRESSURE IS
LOCATED OVER NORTHERN ILLINOIS BY 00Z MON. GIVEN POOR RUN-TO-RUN
CONSISTENCY...FORECAST CONFIDENCE REMAINS LOW BEYOND SATURDAY. WILL
HOWEVER TREND TOWARD THE ECMWF/CANADIAN CONSENSUS FOR THE LATTER
HALF OF THE EXTENDED. THIS WOULD RESULT IN WARM/DRY CONDITIONS ON
SUNDAY...FOLLOWED BY RAIN CHANCES ARRIVING BY MONDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1010 AM CST TUE FEB 21 2012
.DISCUSSION...
ISSUED 1010 AM CST TUE FEB 21 2012
COLD FRONT CONTINUES TO APPROACH THE CWA LATE THIS MORNING...
CURRENTLY ANALYZED FROM ABOUT KANSAS CITY NORTHEAST INTO CENTRAL
WISCONSIN. LARGE AREA OF STRATOCUMULUS AHEAD OF THE FRONT SHOWED A
FEW HOLES EARLIER WHICH HAVE LARGELY FILLED...BUT TRAILING EDGE OF
THE CLOUD DECK JUST STARTING TO CROSS THE MISSISSIPPI RIVER AROUND
QUINCY. LAYER HUMIDITY PLOTS FROM RUC AND NAM SHOWING THIS BACK
EDGE OF THE LOW CLOUDS SHOULD BE ADVANCING NORTHEAST ACROSS THE
CWA THROUGH MID AFTERNOON...HOWEVER SOME MID AND HIGH CLOUDS MOVING
IN AT THE SAME TIME WILL FILTER THE SUNSHINE THAT WOULD OTHERWISE
HAVE OCCURRED.
HAVE SENT SOME MINOR TWEAKS TO THE ZONES/GRIDS...MAINLY TO REMOVE
THE RAIN CHANCES TODAY AND UPDATE THE HOULRY SKY/TEMPERATURE
TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 538 AM CST TUE FEB 21 2012
EXCEPT FOR BMI AND CMI HAVING SOME SCATTERED SHOWERS FOR THE FIRST
HOUR OF THE TAFS...ALL SITES WILL START WITH MVFR CIGS AROUND
2-2.5KFT. BMI AND CMI WILL SEE THESE LOWER CIGS BY 13Z. CIGS WILL
THEN DROP LITTLE MORE AT ALL LOCATIONS AS THE WINDS PICK UP AROUND
14Z...THOUGH CIGS WILL REMAIN IN THE MVFR CATEGORY WITH BMI AND
CMI BELOW 2KFT. THESE LOWER CIGS WILL CONTINUE REST OF THE MORNING
AND THEN IMPROVE IN THE EARLY AFTERNOON. SATELLITE LOOPS SHOWS
THIS CLEARING LINE MOVING EASTWARD INTO PARTS OF MISSOURI AND
IOWA. TIMING TOOL INDICATES THIS CLEARING LINE SHOULD REACH
PIA/SPI EARLY AFTERNOON...FOLLOWED BY DEC/BMI AND THEN CMI
LAST...DURING LATE AFTERNOON. HIGHER SUN ANGLE SHOULD ALSO HELP IN
BURNING OFF BACK EDGE AS IT MOVES EAST. HOWEVER...CIRRUS/HIGH AC
WILL ADVECT INTO THE AREA AT THE SAME TIME AS THE
CLEARING...KEEPING SOME CLOUDS OVER THE SITES DURING THE LATE
AFTERNOON AND INTO THE EARLY EVENING HOURS. MODELS INDICATE
MORE LOW VFR CLOUDS AROUND 4-6KFT ARRIVING DURING THE EVENING
HOURS AT ALL SITES AND LASTING TIL MORNING. SOUTH WINDS WILL
BECOME SOUTHWEST AND INCREASE IN SPEED...BECOMING GUSTY AROUND
23-25KTS FOR THE DAY. WINDS WILL SHIFT IN THE AFTERNOON AND BECOME
WESTERLY...THEN RETURN TO SOUTHWEST FOR THE EVENING AND OVERNIGHT
HOURS. SPEEDS WILL BE LIGHTER AFTER SUNSET.
AUTEN
&&
.PREV DISCUSSION...
ISSUED 239 AM CST TUE FEB 21 2012
SHORT TERM...TODAY THROUGH THURSDAY
VIGOROUS UPPER-LEVEL LOW CURRENTLY OVER MISSOURI WILL TRACK
EASTWARD ACROSS CENTRAL ILLINOIS THIS MORNING. BULK OF SHOWER
ACTIVITY ASSOCIATED WITH THIS FEATURE WILL LIFT N/NE OF THE AREA
BY 12Z...HOWEVER RADAR MOSAIC IS INDICATING SCATTERED LIGHT
SHOWERS DEVELOPING IMMEDIATELY BENEATH THE LOW...SO THINK RAIN
CHANCES ARE STILL WARRANTED THROUGH MIDDAY. ONCE THE LOW SHIFTS
FURTHER EAST...SYNOPTIC SUBSIDENCE ON ITS BACK SIDE WILL RESULT IN
CLEARING SKIES FROM WEST TO EAST DURING THE AFTERNOON. MID/HIGH
CLOUDS CURRENTLY UPSTREAM OVER NEBRASKA WILL STREAM EASTWARD INTO
THE AREA TOWARD EVENING...SO SUNSHINE WILL DEFINITELY BE LIMITED
TODAY. HIGH TEMPS WILL ONCE AGAIN BE ON THE MILD SIDE...WITH
READINGS TOPPING OUT IN THE MIDDLE TO UPPER 40S IN MOST LOCATIONS.
WEAK SHORT-WAVE WILL SKIRT THROUGH THE MIDWEST ON WEDNESDAY...HOWEVER
LACK OF DEEP ATMOSPHERIC MOISTURE WILL PREVENT ANY PRECIP FROM
DEVELOPING. MOSTLY CLOUDY AND DRY CONDITIONS WILL PREVAIL...WITH
HIGHS REACHING THE LOWER TO MIDDLE 50S THANKS TO A SUSTAINED
SOUTHERLY FLOW.
STRONGER WAVE CURRENTLY OVER THE GULF OF ALASKA WILL DROP
SOUTHEASTWARD THROUGH THE NORTHERN ROCKIES INTO THE PLAINS ON
THURSDAY...PUSHING A COLD FRONT INTO CENTRAL ILLINOIS LATE IN THE
DAY. WITH STRONGER UPPER DYNAMICS AND SOMEWHAT MORE FAVORABLE
MOISTURE PROFILES IN PLACE...THINK SCATTERED SHOWERS WILL DEVELOP
AHEAD OF THE FRONT. HAVE THEREFORE INCLUDED LOW CHANCE POPS ACROSS
THE BOARD ON THURSDAY...THEN ACROSS THE E/SE KILX CWA THURSDAY
NIGHT AS THE FRONT PUSHES FURTHER EAST.
LONG TERM...FRIDAY THROUGH MONDAY
DEEP TROUGH WILL DIG ACROSS THE MIDWEST/GREAT LAKES ON
FRIDAY/SATURDAY...RESULTING IN A TEMPORARY COOLING TREND. WITH
CYCLONIC FLOW AND VERY COLD 500MB TEMPS IN PLACE...COULD
POTENTIALLY SEE A FEW SCATTERED RAIN/SNOW SHOWERS ON
FRIDAY...HOWEVER THINK AREAL COVERAGE WILL BE MINIMAL DUE TO LACK
OF STRONG FOCUSING MECHANISM. WILL THEREFORE ONLY MENTION SLIGHT
CHANCE POPS AT THIS TIME. MAIN STORY WILL BE THE COOLER
TEMPS...WITH HIGHS ONLY REACHING THE UPPER 30S/LOWER 40S.
MODELS CONTINUE TO STRUGGLE WITH THE RAPIDLY EVOLVING UPPER
PATTERN LATE IN THE WEEKEND...WITH THE 00Z 21 FEB MODELS SHOWING
DRASTICALLY DIFFERENT SOLUTIONS. ECMWF/CANADIAN BOTH DIG A
PROMINENT TROUGH OVER THE WESTERN CONUS BY SUNDAY...RESULTING IN
RIDGING DOWNSTREAM OVER THE MIDWEST. ASSOCIATED 993MB SURFACE LOW
IS POSITIONED IN EASTERN COLORADO BY 00Z MON. MEANWHILE...THE GFS
IS MUCH WEAKER/MORE PROGRESSIVE WITH THE TROUGH...TRACKING IT
EASTWARD INTO THE MIDWEST MUCH FASTER. ITS SURFACE LOW PRESSURE IS
LOCATED OVER NORTHERN ILLINOIS BY 00Z MON. GIVEN POOR RUN-TO-RUN
CONSISTENCY...FORECAST CONFIDENCE REMAINS LOW BEYOND SATURDAY. WILL
HOWEVER TREND TOWARD THE ECMWF/CANADIAN CONSENSUS FOR THE LATTER
HALF OF THE EXTENDED. THIS WOULD RESULT IN WARM/DRY CONDITIONS ON
SUNDAY...FOLLOWED BY RAIN CHANCES ARRIVING BY MONDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1117 AM EST TUE FEB 21 2012
.AVIATION.../18Z TAFS/.
SOMEWHAT IMPROVING CONDITIONS EXPECTED AT BOTH SITES WITH MVFR
CIGS TO SLOWLY DOMINATE INTO THIS AFTERNOON AS EFFECTS OF
WEAKENING WAVE LESSEN. KSBN MAY SEE A CHANCE FOR SOME LIGHT
SHOWERS INTO THIS AFTERNOON AS A WEAKENING AREA OF RAIN/SNOW MOVES
OUT OF ILLINOIS/WISCONSIN. HAVE LEFT VCSH IN TO COVER. SOME BREAKS
IN CLOUD COVER ALSO NOTED WHICH MAY IMPACT KSBN AND ALLOW FOR
BRIEF IMPROVEMENT IN CIGS.
SIGNS NOT PROMISING FOR CLEARING SKIES TONIGHT AS ADDITIONAL MSTR
STREAMS IN FROM THE NW ACROSS THE AREA. WILL MAINTAIN VFR
CIGS/VSBYS FOR NOW BUT UPSTREAM OBS SUGGEST RETURN TO MVFR WILL BE
POSSIBLE OVERNIGHT.
&&
.UPDATE...
WILL BE UPDATING ZONES AGAIN IN THE NEXT HALF HOUR TO HOUR AS
COMPACT VORT MAX FINALLY SLIDING ACROSS THE AREA AND WEAKENING.
RADAR TRENDS HAVE SHOWN PRECIP FALLING APART RAPIDLY OVER THE PAST
HOUR WITH THIS TREND EXPECTED TO CONTINUE. FEW BREAKS IN THE
CLOUDS OBSERVED BACK ACROSS ILLINOIS WITH RISING TEMPS IN AND
OUT OF CLOUD COVER. AS A RESULT ANY SNOW SHOULD BEGIN TO MELT BACK
OFF WITH IMPROVING ROAD CONDITIONS FOR THOSE AREAS THAT SEEN THE
QUICK SHOT OF SNOW THIS MORNING. LAST AREA OF LIGHT SNOW/RAIN WAS
SEEN MOVING ACROSS SOUTHERN WISCONSIN INTO NORTHERN ILLINOIS. THIS
HAS BEEN SHOWING SIGNS OF WEAKENING AS WELL. WILL BE GETTING RID
OF A LOT OF THE POPS INTO THIS AFTERNOON EXCEPT NORTHERN SECTIONS
WHERE ABOVE MENTIONED PRECIP MAY CLIP. HIGHS ON TRACK FOR THE TIME
BEING SO NO CHANGES.
.PREV DISCUSSION... /ISSUED 351 AM EST TUE FEB 21 2012...CORRECTION/
SHORT TERM... / TODAY THROUGH WEDNESDAY NIGHT /
POTENT NEGATIVELY TILTED SHORTWAVE OVER MISSOURI WILL TRACK QUICKLY
NEWD THROUGH THE NORTHERN OHIO VALLEY THIS MORNING...WEAKENING A BIT
AS IT BEGINS TO PHASE WITH A NORTHERN STREAM WAVE DROPPING INTO THE
UPPER MIDWEST. THIS MISSOURI NEGATIVE HEIGHT ANOMALY LOOKS
IMPRESSIVE ON WATER VAPOR THIS MORNING WITH A TROWAL CLEARLY
EVIDENT. HOWEVER QUICK MOVEMENT AND SLIGHT WEAKENING TREND WILL
RESULT IN A LIGHTER PCPN AMOUNTS LOCALLY...GENERALLY BTW
0.10-0.25". STILL EXPECTING ABOUT A 2-3 HOUR PERIOD OF ORGANIZED
PCPN...WHICH WILL BE TIED TO A NARROW PLUME OF DEEP MOIST ASCENT
ON THE NOSE OF A ~50 KT LLJ AS CPD`S RAPIDLY LOWER FROM NEAR 200
MB TO 0-5 MB ON THE 290K SFC. USED A MODEL BLEND (MORE WEIGHT TO
HIGH RES GUIDANCE) TO TIME HIGHER POPS THROUGH THE FA. VERY DRY
ANTECEDENT AIRMASS PER 00Z AREA RAOBS AND DYNAMIC NATURE TO SYSTEM
STILL DOES SUPPORT THE CHANCES FOR A RAIN/SNOW MIX NW OF HIGHWAY
24...WITH A BRIEF BURST OF SNOW POSSIBLY SUPPORTING SOME LIGHT
ACCUMS MAINLY ALONG/NORTH OF ROUTE 6 IN INDIANA AND MICHIGAN.
STEEPENING MID LVL LAPSE RATES AND STRONG DYNAMIC/EVAPORATIVE
COOLING SUPPORT THE GOING CHC FOR A BRIEF PERIOD OF WET
SNOW...ESPECIALLY GIVEN TRENDS OF LATEST 05Z HRRR AND 06Z NAM.
THE LOW LVL FLOW WILL VEER SOUTHWESTERLY BEHIND AN OCCLUDED FRONT...
ALLOWING THE LOWEST 3 KFT TO WARM WELL ABOVE FREEZING EVERYWHERE BY
LATE MORNING AND AFTERNOON. ALSO...A TIGHTENING PRESSURE GRADIENT
WILL SUPPORT A BREEZY AFTERNOON WITH GUSTS OF 20-30 MPH POSSIBLE
PER BUFR MOMENTUM TRANSFER PROGS. DEEPER MOISTURE/LIFT WILL EXIT
TO THE EAST LEAVING A LOW OVERCAST AND DRIER CONDITIONS IN ITS
WAKE. HOWEVER..LINGERING MOIST LOW LEVELS AND POSSIBLE WEAK LIFT
FROM A SECONDARY SHORTWAVE COULD STILL SPARK A FEW SHOWERS THIS
AFTERNOON INTO EARLY THIS EVENING.
A SERIES OF SHORTWAVES WILL EMERGE OUT OF A 140 KT PLUS NORTH
PACIFIC UPPER JET THAT WILL HAVE WORKED WELL INLAND INTO THE CENTRAL
PLAINS BY WEDNESDAY/WEDNESDAY NIGHT. THIS WILL SUPPORT MID LVL
TROUGHING INTO THE CENTRAL CONUS AND FAST WESTERLY FLOW ALOFT
LOCALLY. GIVEN NEGATIVE THETA-E ADV IN THE LOW LEVELS TONIGHT WOULD
EXPECT ANY SHORTWAVE ENERGY IN FAST FLOW TO HAVE TROUBLE GENERATING
ANY RAINFALL ON WEDNESDAY. THERE APPEARS TO BE A BETTER CHANCE FOR
MEASURABLE RAINFALL BY WEDNESDAY NIGHT AS A MID LEVEL BAROCLINIC
ZONE LOOKS TO TIGHTEN OVERHEAD.
LONG TERM...
HIGH ENERGY NEPAC WAVE TRAIN AND ASSOCD/INTENSE UPR JET YIELDING
EXTREME MODEL VARIABILITY W/TIME ONCE AGAIN THIS MORNING AND
ALREADY MANIFESTING ITSELF TO BEGIN THE PD ON DY3 THU. PSBL EPAC
RECON TOMORROW EVENING WILL LEAD TO MITIGATION OF THE UNCERTAINTY
LTR THIS WEEK.
REGARDLESS PRIOR GRID ALIGNMENT STILL HOLDS FOR DY3 GIVEN A CONTD
PREFERENCE/DEPENDENCE ON ECMWF W/CORRESPONDING NOD FM UKMET...BOTH
OF WHICH DIG ROBUST NRN STREAM SW SEEN IN VAPOR NR 48N/163W THIS
MORNING QUICKER AND FARTHER WEST WHILE GFS SYSTEMIC PROGRESSION
BIASES RENDER ITS SOLUTION SUSPECT. THIS HWVR DOES NECESSITATE CHGS
FRI AS MID LVL DEFORMATION ZONE IS MORE LIKELY TO HANG BACK IN
RESPONSE TO SIG ERN OH VALLEY CYCLOGENESIS AT LEAST THROUGH MORNING.
OTHERWISE CHGS BEYOND DY4 DEEMED FUTILE GIVEN RAMPANT MODEL SPREAD
AND UNCERTAINTY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 11 AM EST WEDNESDAY FOR LMZ043-046.
&&
$$
SHORT TERM...STEINWEDEL
LONG TERM...T
AVIATION...FISHER
UPDATE...FISHER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
459 PM CST TUE FEB 21 2012
...AVIATION UPDATE...
.DISCUSSION...
SEE PREV DISCUSSION.
&&
.AVIATION...
THE NAM AND RUC FORECAST SOUNDINGS ARE INDICATING A STEEP NOCTURNAL
INVERSION SETTING UP LATE TONIGHT. SO THERE IS A CONCERN FOR SOME
LOW LEVEL WIND SHEER. WILL WATCH AND SEE HOW THE 00Z MODELS COME IN.
OTHERWISE DRY AIR IN THE LOWEST COUPLE KILOMETERS WILL LEAD TO VFR
CONDITIONS.
WOLTERS
&&
.PREV DISCUSSION... /334 PM CST TUE FEB 21 2012/
WESTERLY FLOW IN THE MID LEVELS WILL CONTINUE THROUGH THE PERIOD. A
SHORTWAVE WILL DROP SOUTHWEST OUT OF THE PACIFIC NORTHWEST LATE
TONIGHT WITH INCREASE IN MID LEVEL MOISTURE SO EXPECT A MID CLOUD
DECK TO MOVE OVER AFTER MIDNIGHT THEN EXIT DURING THE MORNING HOURS
ON TUESDAY. AS ANOTHER WAVE MOVES ACROSS THE NORTHERN PLAINS ON
TUESDAY MORE CLOUDS WILL MOVE INTO THE FAR NORTHERN COUNTIES IN THE
AFTERNOON NEAR THE NEBRASKA BORDER.
TONIGHT THE WINDS WILL DROP OFF AFTER SUNSET AS THE WINDS DECOUPLE
IN THE BOUNDARY LAYER. THIS WILL ALLOW TEMPERATURES TO COOL INTO THE
LOW TO MID 30S.
ON TUESDAY...THE COMBINATION OF WESTERLY DOWNSLOPE FLOW...ABUNDANT
SUNSHINE AND MIXING DOWN FROM 800 MB WILL YIELD HIGHS IN THE LOW TO
MID 60S FOR MUCH OF THE AREA. WEST WINDS WILL GUST OVER 20 MPH IN
THE AFTERNOON.
53
NEXT SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN PLAINS WEDNESDAY
NIGHT/THURSDAY WILL FOCUS PRECIP TO THE NORTH OF THE AREA WITH
STILL A DRY FCST FOR THIS PERIOD. HOWEVER...AFTER WESTERLY WINDS
MOST OF THE NIGHT...A FRONT WILL BEGIN TO TRAVERSE THE CWA LATE IN
THE NIGHT. THE TIMING OF THE FRONT WILL LIKELY BE TOO LATE TO HAVE
A LOT OF IMPACT ON LOW TEMPS...EXCEPT MAYBE THE FAR NORTH WHERE A
FEW READINGS IN THE MIDDLE 30S ARE EXPECTED. ELSEWHERE...TEMPS
EXPECTED TO REMAIN WELL ABOVE NORMAL WITH LOWS SOUTH OF I 70
GENERALLY 40 TO 43 DEGREES. THE AFFECTS OF THE COLDER AIR MOVING
INTO THE CWA BEHIND THE FRONT WILL BE FELT MORE DURING THE DAY
THURSDAY AS HIGH TEMPS TOP OUT IN THE UPPER 40S AND LOWER 50S...OR
ABOUT 10 TO 15 DEGREES COOLER THAN WEDNESDAY ALONG WITH A BLUSTERY
NORTHWEST.
THE COOLEST HIGHS STILL LOOK TO BE ON FRIDAY WHERE THE COOLER LOWS
IN THE 20S TO AROUND 30 WILL HELP TO LIMIT THE DAYTIME HIGHS TO THE
40S. THE UPPER LEVEL PATTERN INTO THE WEEKEND STILL SHOWS THE UPPER
LEVEL SHORTWAVE TROUGH OVER THE GREAT LAKES MOVING OFF THE EAST
COAST WITH ANOTHER STRONG UPPER TROUGH ADVANCING FROM THE PACIFIC
NORTHWEST AND INTO THE NORTHERN PLAINS BY SUNDAY. WARM AIR ADVECTION
AHEAD OF THIS SYSTEM OVER THE WEEKEND SHOULD PUSH HIGHS INTO THE
LOWER 50S IN MANY AREAS BEFORE THE NORTHERN PLAINS WAVE PUSHES
ANOTHER COLD FRONT ACROSS THE CWA SUNDAY NIGHT. THIS WILL PROVIDE
THE NEXT CHANCE FOR RAIN OR POSSIBLY SOME SNOW SUNDAY NIGHT AS THE
COLDER AIR OVERSPREADS THE AREA BEHIND THE FRONT.
THERE MAY THEN BE A BRIEF BREAK IN PRECIP CHANCES DURING THE DAY ON
MONDAY BEFORE ANOTHER SYSTEM APPROACHES THE CENTRAL PLAINS FROM THE
ROCKIES LATER MONDAY NIGHT INTO TUESDAY. IF THIS SCENARIO
HAPPENS...MORE COLD AIR WOULD ALREADY BE IN PLACE AHEAD OF IT AND
THEREFORE SNOW CHANCES WOULD BE A LITTLE HIGHER. IT IS DIFFICULT
THIS FAR OUT IN THIS PATTERN TO GO WITH AN ALL SNOW FORECAST FOR AN
EXTENDED PERIOD OF TIME. WILL GO WITH A LIGHT SNOW/RAIN SNOW MIX
MONDAY NIGHT AND TUESDAY FOR NOW WITH HIGHS TUESDAY IN THE 30S. 63
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1248 PM EST TUE FEB 21 2012
.SYNOPSIS...
AN EASTBOUND OCCLUDED FRONT WILL PROVIDE SHOWERS AND GUSTY WINDS
THIS AFTERNOON, KEEPING TEMPERATURES MILD INTO THURSDAY. A STRONGER COLD
FRONT PASSES FRIDAY, USHERING IN COLD WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOOKS LIKE VARIABLE MARCH WEATHER HAS ARRIVED EARLY.
PER RECENT SURFACE AND RADAR DATA, THE FRONTAL BAND OF RAIN
SHOWERS HAS BEEN LEADING OFF WITH A SHORT PERIOD OF LIGHT SNOW
SHOWERS, DESPITE TEMPERATURES OVER 40 DEGREES. THIS IS DUE TO
EVAPORATIONAL COOLING EFFECTS WITHIN THE INITIALLY DRY SURFACE
LAYER. NATURAL GRASSY SURFACES CAN BE COLDER THAN 32, SO A FEW
FLAKES CAN ACCUMULATE THERE, BUT PAVEMENTS BEING TREATED WILL JUST
BECOME WET.
MORE NOTEWORTHY IS THAT SURFACE WINDS CAN GUST UP TO 35 TO 40 MPH
IN THE WAKE OF THESE SHOWERS, PER BLEND OF RECENT SURFACE DATA AND
NAM MODEL PROFILES.
TEMPERATURE DETAILS WERE BASED ON BLEND OF RECENT HRRR, NAM, AND
GFS LAMP OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
RAIN CHANCES SHOULD DECREASE AS A SHORT WAVE TROUGH EXITS TO THE
NORTHEAST TONIGHT, BUT A SURFACE BOUNDARY STRETCHED ACROSS THE
FORECAST AREA WILL MAINTAIN AT LEAST A CHANCE OF SHOWERS WEDNESDAY
INTO WEDNESDAY NIGHT.
MODELS SHOW A SURFACE LOW TRACKING EAST ACROSS THE GREAT LAKES
WITH A WARM FRONT PUSHING THROUGH THE UPPER OHIO VALLEY THURSDAY.
RAIN CHANCES WILL INCREASE AND TEMPERATURES SHOULD WARM INTO THE
50S TO LOWER 60S IN THE WARM SECTOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
VERY LITTLE CONFIDENCE IN THE LONG TERM AS MODEL DIFFERENCES MAKE
IT DIFFICULT TO PIN DOWN A CONSISTENT FORECAST.
STRONG FRONT WILL PASS THROUGH ON FRIDAY, BUT STILL DISCREPANCIES
ON TIMING AND IF SFC WAVE WILL DEVELOP ALONG THE FRONT.
MUCH COLDER AIR FOR THE WEEKEND. WITH LES POSSIBLE SATURDAY INTO
EARLY SUNDAY.
DIFFERENCES IN SOLUTIONS CONTINUE INTO THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
PER RECENT SURFACE AND HRRR MODEL OUTPUT, EXPECT A FRONTAL BAND OF
MAINLY MVFR SHOWERS TO COMPLETE ITS EASTWARD PINWHEEL THROUGH THE
UPPER OHIO VALLEY BY LATE AFTERNOON. EVAPORATIONAL COOLING WITHIN THE
INITIALLY DRY SURFACE LAYER CAN CAUSE UP TO 1 HOUR OF PURE SNOW
SHOWERS AT THE START WITH IFR VISIBILITIES, MAINLY AT KFKL AND
KDUJ AND POSSIBLY KLBE.
WINDS CAN GUST TO 35 KTS IN THE WAKE OF THE SHOWERS. THE SHOWERS
SHOULD EXIT EAST INTO THE MOUNTAINS BY 22Z.
NAM MODEL PROFILES SHOW WIND GUSTS SUBSIDING TO 20-25 KTS AFTER
01Z. CONSENSUS OF NAM AND GFS LAMP/MOS SHOW STRATOCUMULUS CEILINGS
CAN REMAIN AT MVFR LEVELS INTO DAYTIME WEDNESDAY. SHOWERS
ASSOCIATED WITH ANOTHER FRONTAL PASSAGE COULD MAINTAIN MVFR
CONDITIONS THROUGH THE AFTERNOON.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
RESTRICTIONS POSSIBLE WITH RAIN SHOWERS WEDNESDAY NIGHT AND
THURSDAY. A MORE PROLONGED PERIOD OF RESTRICTIONS POSSIBLE FRIDAY
INTO SATURDAY DUE TO A STRONG COLD FRONTAL PASSAGE FRIDAY,
PROVIDING RAIN SHOWERS DAYTIME FRIDAY, FOLLOWED BY COLD POOL LOW
CLOUDS AND SCATTERED SNOW SHOWERS FRIDAY NIGHT INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1127 AM EST TUE FEB 21 2012
.SYNOPSIS...
AN EASTBOUND OCCLUDED FRONT WILL PROVIDE SHOWERS AND GUSTY WINDS
THIS AFTERNOON, KEEPING TEMPERATURES MILD INTO THURSDAY. A STRONGER COLD
FRONT PASSES FRIDAY, USHERING IN COLD WEATHER FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOOKS LIKE VARIABLE MARCH WEATHER HAS ARRIVED EARLY.
PER RECENT SURFACE AND RADAR DATA, THE FRONTAL BAND OF RAIN
SHOWERS HAS BEEN LEADING OFF WITH A SHORT PERIOD OF LIGHT SNOW
SHOWERS, DESPITE TEMPERATURES OVER 40 DEGREES. THIS IS DUE TO
EVAPORATIONAL COOLING EFFECTS WITHIN THE INITIALLY DRY SURFACE
LAYER. NATURAL GRASSY SURFACES CAN BE COLDER THAN 32, SO A FEW
FLAKES CAN ACCUMULATE THERE, BUT PAVEMENTS BEING TREATED WILL JUST
BECOME WET.
MORE NOTEWORTHY IS THAT SURFACE WINDS CAN GUST UP TO 35 TO 40 MPH
IN THE WAKE OF THESE SHOWERS, PER BLEND OF RECENT SURFACE DATA AND
NAM MODEL PROFILES.
TEMPERATURE DETAILS WERE BASED ON BLEND OF RECENT HRRR, NAM, AND
GFS LAMP OUTPUT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
RAIN CHANCES SHOULD DECREASE AS A SHORT WAVE TROUGH EXITS TO THE
NORTHEAST TONIGHT, BUT A SURFACE BOUNDARY STRETCHED ACROSS THE
FORECAST AREA WILL MAINTAIN AT LEAST A CHANCE OF SHOWERS WEDNESDAY
INTO WEDNESDAY NIGHT.
MODELS SHOW A SURFACE LOW TRACKING EAST ACROSS THE GREAT LAKES
WITH A WARM FRONT PUSHING THROUGH THE UPPER OHIO VALLEY THURSDAY.
RAIN CHANCES WILL INCREASE AND TEMPERATURES SHOULD WARM INTO THE
50S TO LOWER 60S IN THE WARM SECTOR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
VERY LITTLE CONFIDENCE IN THE LONG TERM AS MODEL DIFFERENCES MAKE
IT DIFFICULT TO PIN DOWN A CONSISTENT FORECAST.
STRONG FRONT WILL PASS THROUGH ON FRIDAY, BUT STILL DISCREPANCIES
ON TIMING AND IF SFC WAVE WILL DEVELOP ALONG THE FRONT.
MUCH COLDER AIR FOR THE WEEKEND. WITH LES POSSIBLE SATURDAY INTO
EARLY SUNDAY.
DIFFERENCES IN SOLUTIONS CONTINUE INTO THE BEGINNING OF NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
PER RECENT SURFACE AND HRRR MODEL OUTPUT, EXPECT A FRONTAL BAND OF
MAINLY MVFR SHOWERS TO PINWHEEL EASTWARD THROUGH THE UPPER OHIO
VALLEY TODAY. EVAPORATIONAL COOLING WITHIN THE INITIALLY DRY
SURFACE LAYER CAN CAUSE UP TO 1 HOUR OF SNOW SHOWERS AT THE START
WITH IFR VISIBILITIES POSSIBLE.
WINDS CAN GUST TO 35 KTS IN THE WAKE OF THE SHOWERS. THE SHOWERS
SHOULD EXIT EAST INTO THE MOUNTAINS BY 22Z.
OUTLOOK...TONIGHT THROUGH SATURDAY...
VFR TONIGHT WITH SUBSIDING WIND. RESTRICTIONS POSSIBLE WITH FRONTAL
BANDS OF RAIN SHOWERS WEDNESDAY AND THURSDAY. A MORE PROLONGED
PERIOD OF RESTRICTIONS POSSIBLE FRIDAY INTO SATURDAY DUE TO A
STRONG COLD FRONTAL PASSAGE FRIDAY, WITH RAIN SHOWERS FRIDAY,
FOLLOWED BY COLD POOL LOW CLOUDS AND SCATTERED SNOW SHOWERS FRIDAY
NIGHT INTO SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
407 PM EST TUE FEB 21 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM EST TUE FEB 21 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER NRN
MN WITH A SHORTWAVE TROUGH EXTENDING INTO NW WI. 850-500 MB QVECTOR
CONV AND MID LEVEL FGEN ASSOCIATED WITH THE SHRTWV SUPPORTED A BAND
OF SNOW ACROSS CNTRL UPPER MI. SO...FAR ACCUMULATIONS HAVE BEEN
LIGHT...GENERALLY LESS THAN AN INCH. AT THE SFC...A 992 MB LOW WAS
LOCATED NEAR KINL WITH MOST OF THE SNOW AHEAD OF A TROUGH EXTENDING
TO THE SE THROUGH WRN UPPER MI INTO NE WI. ADDITIONAL SNOW OVER NE
MN WITH WRAP-AROUND MOISTURE NEAR THE MID LEVEL LOW WAS MOVING BACK
INTO NW WI.
RADAR TRENDS AND NAM/RUC FCST SUGGEST THAT THE INITIAL SNOWBAND WILL
MOVE OUT OF CNTRL UPPER MI INTO THE ERN CWA LATE THIS AFTERNOON AND
EVENING. THE SNOW AREA OVER MN IS ALSO EXPECTED TO SHIFT INTO WRN
UPPER MI THIS EVENING BRINGING POTENTIAL FOR ADDITIONAL LIGHT
ACCUMULATIONS OF AN INCH OR TWO. EVEN THOUGH THE STRONGER SYNOPTIC
FORCING IS FCST NEAR KIWD... THE COMBINATION OF CONVERGENT WRLY FLOW
AND 850 MB TEMPS DROPPING TO AROUND -8C WILL ALSO RESULT IN SOME
LAKE ENHANCED SNOW OVER NW UPPER MI WITH SNOWFALL AMOUNTS INTO THE 1
TO 3 INCH RANGE. AS THE WINDS VEER SLIGHTLY WED...THE LAKE ENHANCED
SNOW SHOULD ALSO MOVE INTO LOCATIONS NEAR LAKE SUPERIOR EAST OF
MUNISING. THE REMAINING SNOW OVER THE WEST WILL DIMINISH WED AS
HIGH PRESSURE AND DRIER AIR MOVE INTO THE AREA BEHIND THE DEPARTING
MID LEVEL LOW.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 400 PM EST TUE FEB 21 2012
THE 500MB LOW CURRENTLY OVER N MN THIS AFTERNOON WILL BE ALONG THE
ONTARIO/QUEBEC BORDER TO BEGIN THIS PERIOD. THE NEXT TROUGH SLIDING
IN FROM THE NW WILL BE BROAD...STRETCHING FROM W MANITOBA TO E LAKE
SUPERIOR/CENTRAL LAKE MI THURSDAY AFTERNOON. FCST MODELS BEGIN TO
DIVERGE EARLIER THAN NORMAL...THURSDAY AFTERNOON /DAY 2/.
THE 21/06Z NAM IS A QUICK OUTLIER...WITH A CLOSED LOW DEVELOPING
NEAR THE MACKINAC BRIDGE...BEFORE SHIFTING TO S QUEBEC FRIDAY
AFTERNOON. WHILE THE 21/06Z GFS HAS A SIMILAR TREND...IT IS APPROX 6
HOURS SLOWER. THE 21/09Z SREF TENDS TO FOLLOW A SOLUTION SIMILAR TO
THE GFS...WHILE THE 21/00Z CANADIAN IS AN AVERAGE BETWEEN THE
GFS/SREF AND THE MUCH SLOWER 21/00Z ECMWF /LOW OVER W ONTARIO WHILE
THE GFS HAS IT OVER THE S ONTARIO/QUEBEC BORDER/. THE ECMWF DOES NOT
PLACE THE LOW OVER THE S ONTARIO/QUEBEC BORDER UNTIL 12Z
SATURDAY...OR 18HRS BEHIND THE GFS. WILL PUSH THIS FORECAST CLOSER
TO A GFS SOLUTION THROUGH THE END OF THE WORK WEEK. THIS WILL RESULT
IN UPPER MI AND LAKE SUPERIOR STUCK BETWEEN THE FIRST SFC LOW
EXITING INTO QUEBEC AT 00Z THURSDAY...WITH THE STRONGER LOW
DEVELOPING OVER THE N PLAINS AND CENTRAL CANADA. A WEAK SFC TROUGH
WILL CONNECT THE TWO. THE MOST SIGNIFICANT CONTRAST THE MODELS CAN
BE SEEN OFF THE 00Z FRIDAY SFC MAP. THERE IS A CLUSTER OF MODELS
/GFS/NAM/SREF/ WITH THE LOW OVER CENTRAL TO N LOWER MI. BY CONTRAST
THE CANADIAN HAS IT ALONG THE LOWER MI/IA/OH BORDER...WITH THE ECMWF
ALONG THE CONFLUENCE OF THE OHIO AND MISSISSIPPI RIVERS. AS STATED
ABOVE...WILL PUSH THE FCST TO A MORE CENTRAL LOWER MI SOLUTION AT
00Z FRIDAY. THIS WILL KEEP THE BULK OF THE SYNOPTIC MOISTURE FALLING
JUST SOUTH OF THE CWA.
AFTER 18Z FRIDAY ALL OF THE SOLUTIONS COME INTO SOME BASIC AGREEMENT
OVER OUR CWA...WITH N TO NW WINDS AND 850MB TEMPS IN THE -8 TO -12C
RANGE. 850MB TEMPS OF -14 TO -16C SHOULD BE COMMON BY SUNDAY
AFTERNOON...BEFORE WAA ON MORE SW WINDS TAKE HOLD SATURDAY NIGHT.
STRONG SSW WINDS WILL LIKELY TAKE HOLD SUNDAY AFTERNOON INTO SUNDAY
NIGHT /DEPENDING ON THE TIMING OF THE NEXT LOW. THE ECMWF ENDS UP
BEING ROUGHLY 12 HOURS SLOWER THAN THE GFS WITH THIS NEXT SYSTEM
COMING OUT OF THE PLAINS. A STRONGER MORE NORTHERLY LOW OFF THE
ECMWF WOULD BRING 850MB TEMPS OF 2C...COMPARED TO THE WARMEST
READINGS OFF THE GFS OF -6C. AT 00Z TUESDAY THE SFC 983MB SFC LOW
OFF THE ECMWF IS OVER NE MN...WHILE AT THE SAME TIME THE
WEAKER/QUICKER GFS HAS A 1003MB LOW OVER FAR S QUEBEC. GIVEN THE
LOWER CONFIDENCE WITH THE FORECAST WILL NOT DIVE TO MUCH INTO THE
SPECIFICS...AND KEEP A CONSENSUS GOING FROM SATURDAY NIGHT ON. EVEN
WITH ALL THE DIFFERENCES...SUNDAY NIGHT LOOKED TO BE A GOOD
OPPORTUNITY TO INCLUDE LIKELY POPS OVER S CENTRAL UPPER MI.
OTHERWISE...WILL KEEP CHANCE OF LESS POPS GOING THROUGH MUCH OF THE
PERIOD WITH LOWER THAN NORMAL CONFIDENCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1247 PM EST TUE FEB 21 2012
WITH LOW LEVEL MOISTURE IN PLACE OVER THE REGION...EXPECT IFR
CONDITIONS TO PERSIST AT KCMX/KSAW THIS AFTERNOON WHILE DOWNSLOPE
SRLY FLOW INTO KIWD RESULTS IN CIGS AOA MVFR THRESHOLD.
TONIGHT...WRLY WINDS WITH LAKE ENHANCED SNOW WILL KEEP MAINLY IFR
CONDITIONS OR LOWER END MVFR AT KCMX/KIWD. HOWEVER...CIGS SHOULD
LIFT A BIT A KSAW AS WINDS VEER MORE SW TO W.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST TUE FEB 21 2012
AS LOW PRESSURE SLIDES EASTWARD THROUGH NRN LAKE SUPERIOR AND
INTO QUEBEC BY WED AFTERNOON...WRLY WINDS WILL INCREASE TO 20 TO 30
KT TONIGHT INTO WED. WINDS WILL DIMINISH LATE WED INTO WED NIGHT AS
HIGH PRES BUILDS INTO THE UPPER GREAT LAKES. WINDS WILL THEN REMAIN
RELATIVELY LIGHT INTO UNTIL FRI WHEN NRLY WINDS OF 15 TO 25 KT ARE
POSSIBLE AS LOW PRESSURE MOVES TO THE SOUTH OF THE REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
105 PM EST TUE FEB 21 2012
.UPDATE...
ISSUED AT 102 PM EST TUE FEB 21 2012
NOT MUCH OF ANYTHING GOING ON ACROSS THE FORECAST AREA AT EARLY
AFTERNOON...SAVE FOR SOME LIGHT SNOW AROUND SAGINAW BAY. SO HAVE
BEEN TRYING VAINLY TO GET THE PUBLIC/AVIATION FORECASTS SQUARED
AWAY TO REFLECT NEW REALITY...WHICH WILL FOCUS ON BAND OF
PRECIPITATION COMING OUT OF OF WISCONSIN ASSOCIATED WITH NORTHERN
BRANCH SHORT WAVE SPINNING ITS WAY ACROSS THE UPPER MIDWEST. THIS
SHOULD PUSH INTO FAR NORTHWEST LOWER MICHIGAN TOWARD 21Z...THEN
CROSS EASTERN UPPER AND FAR NORTHERN LOWER DURING THE EVENING
HOURS. MAY SEE SOME DRIZZLE DEVELOP FARTHER SOUTH THIS EVENING AS
LOWER CEILINGS SPREAD NORTHEAST AS WELL.
UPDATE ISSUED AT 1002 AM EST TUE FEB 21 2012
NO CHANGES MADE TO GOING FORECAST AT THIS POINT...WILL MAKE TWEAKS
AS NEEDED GOING FORWARD WITH RESPECT TO PRECIPITATION START TIMES.
UPDATE ISSUED AT 642 AM EST TUE FEB 21 2012
PRECIPITATION ONSET LOOKING ON TRACK GIVEN CURRENT OBSERVATIONS
SHOWING SNOW BREAKING OUT OVER SOUTHEAST WISCONSIN AND LIKELY OVER
THE SOUTHERN THIRD OF LAKE MICHIGAN AT THIS HOUR. RAOB JUST SENT
UP AT APX SHOWS IMPRESSIVE DRY WEDGE TO OVERCOME /30C DEWPOINT
DEPRESSIONS AT H85 WITH DRY WEDGE EXTENDING TO H6/ SO EXPECT THAT
WHILE CURRENT RADAR ECHOES LOOK A LITTLE OMINOUS...IT WILL TAKE
MANY MORE HOURS FOR PRECIPITATION TO FILL IN. THIS IS IN GOOD
AGREEMENT WITH 08/09Z HRRR WHICH SUGGESTS THAT PRECIPITATION WILL
STRUGGLE TO MAKE IT MUCH FURTHER NORTH THAN M-72 BY NOON.
SO...LITTLE TWEAKS IN THE POP/WEATHER DEPARTMENT. UPDATED SKY
BASED ON SLIGHTLY FASTER CLOUD-UP OVER EASTERN UPPER...BUT
OTHERWISE...LITTLE CHANGES NEEDED IN THIS UPDATE.
&&
.SYNOPSIS...
ISSUED AT 333 AM EST TUE FEB 21 2012
HIGH PRESSURE WILL EXIT INTO THE WESTERN ATLANTIC TODAY...AS
WEAKENING LOW PRESSURE TRACKS THROUGH THE GREAT LAKES INTO THIS
EVENING. THIS SYSTEM WILL BRING A BRIEF ROUND OF LIGHT RAIN AND SNOW
SHOWERS TO THE REGION THROUGH LATE EVENING...THOUGH WITH LITTLE TO
NO SNOW ACCUMULATION EXPECTED. LOOKING INTO THE REST OF THE WORK
WEEK...SEVERAL ADDITIONAL WEAK WEATHER SYSTEMS WILL PROGRESS THROUGH
THE AREA...EACH SUPPLYING SMALL CHANCES FOR SOME LIGHT RAIN OR SNOW.
HOWEVER...NO SIGNIFICANT SNOW ACCUMULATION IS EXPECTED THROUGH AT
LEAST SATURDAY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
EARLY MORNING SURFACE ANALYSIS REVEALS DOUBLE-BARRELED LOW PRESSURE
SYSTEM ADVANCING NORTH AND EAST TOWARDS THE FORECAST AREA. 30-40 KT
LOW LEVEL JET RIDING UP AND OVER LOW LEVEL COOL DOME HAS PRODUCED A
FAIRLY WIDESPREAD REGION OF GENERALLY LIGHT PRECIPITATION THAT IS
PUSHING INTO EASTERN WISCONSIN AS OF THIS WRITING. DOUBLE BARRELED
STRUCTURE AT THE SURFACE HAS BEEN PRODUCED BY COMPETING MID AND
UPPER LEVEL SHORTWAVES...ONE COMPACT CENTER OVER NORTHERN MISSOURI
AND ANOTHER LARGER SCALE FEATURE OVER NORTH DAKOTA. MODEL TRENDS
OVER THE PAST 48 HOURS HAVE BEEN FOR A STRONGER AND FURTHER SOUTH
NORTHERN FEATURE...WHICH WILL DO A GOOD JOB OF KICKING THE SOUTHERN
WAVE SOUTH AND EAST OF OUR REGION TODAY. THIS LEAVES A GENERALLY
WEAK FORCING FOR ASCENT AS THE BEST DEEP MOISTURE SHIFTS EAST WITH
THE SOUTHERN WAVE...ALLOWING ONLY MODEST MOISTENING IN OUR REGION AS
MODEST QVECTOR CONVERGENCE AND FGEN FORCING ARRIVE.
00Z RAOBS FROM APX/GRB SHOW A PRETTY DRY ANTECEDENT AIRMASS WITH
PWATS BELOW TWO TENTHS OF AN INCH WITH DRY SOUTHEASTERLY FLOW IN THE
LOW LEVELS HELPING KEEP THIS DRY PROFILE IN PLACE. SO...MODEL
TRENDS FOR SLOWER PRECIPITATION ARRIVAL...AND LOWER PRECIPITATION
AMOUNTS ARE NOT A SURPRISE...AND EXPECT MINIMAL IMPACTS FOR THE
REGION TODAY. LIGHT SNOW...WHICH MAY ARRIVE IN BROKEN ELEMENTS
RATHER THAN A SOLID SHIELD...SHOULD ADVANCE FROM SOUTHWEST TO
NORTHEAST ACROSS NORTHERN LOWER BY BY NOON...WITH ANY ACTIVITY
HOLDING OFF IN EASTERN UPPER UNTIL LATE IN THE DAY. PRECIPITATION
COVERAGE MAY ACTUALLY INCREASE SOME TOWARDS EVENING AS QG FORCING
ASSOCIATED WITH THE NORTHERN STREAM FINALLY ARRIVES...WITH
INCREASINGLY CYCLONIC BOUNDARY LAYER FLOW ALSO ASSISTING.
A MIX WITH RAIN ALSO LOOKS TO BE IN THE CARDS...AS BOUNDARY LAYER
TEMPERATURES MAKE A RUN AT THE UPPER 30S NEAR THE LAKES AS
PRECIPITATION ARRIVES. THIS WILL ALSO BE HELPED BY THE GENERALLY
LIGHT PRECIPITATION RATES...WHICH WILL BETTER ALLOW THE SURFACE
LAYER TO DICTATE PRECIPITATION TYPE. EVEN WHERE PRECIPITATION
REMAINS ALL SNOW...INCREASING SUN ANGLES /EVEN WITH CLOUD COVER/
SUGGESTS THAT EVEN OVER THE HIGHER TERRAIN OF NORTHERN LOWER...WHERE
PRECIPITATION REMAINS ALL SNOW...THE HALF INCH OF SNOW EXPECTED WILL
HAVE TROUBLE STICKING TO AREA ROADWAYS.
AFOREMENTIONED SURFACE LOW SETTLES OVER NORTHERN LAKE SUPERIOR
TONIGHT WITH T85S FALLING TO ABOUT -8C WITH CONTINUED DECENT
SYNOPTIC MOISTURE AND CYCLONIC LLEVEL FLOW SUGGESTING LAKE ENHANCED
SHSN ACTIVITY WILL LIKELY PERSIST THROUGH MUCH OF THE NIGHT. WITH
COOLING BOUNDARY LAYER TEMPERATURES...EXPECT SNOW TO STICK A LITTLE
BETTER AND HAVE PAINTED UP TO AN INCH IN THE FORECAST OVERNIGHT OVER
EASTERN UPPER...AS WELL AS THE HIGHER TERRAIN OF NORTHERN LOWER
WHERE SOME UPSLOPE ENHANCEMENT UNDER WEST-SOUTHWEST FLOW WILL BOOST
PRECIPITATION TOTALS SLIGHTLY. WILL LEAN TOWARDS THE WARMER END OF
THE GUIDANCE SUITE FOR TEMPERATURES GIVEN CLOUD COVER AND
PRECIPITATION...WITH UPPER 20S LOOKING GOOD FOR MOST SPOTS.
LOW PRESSURE NORTH OF THE REGION GRADUALLY FILLS AND SHIFTS EAST ON
WEDNESDAY WITH A GRADUAL DOWN-TICK IN MOISTURE AND SLIGHT WARMING OF
TEMPS AT H85. THIS INDICATES THAT SHSN ACTIVITY WILL GRADUALLY
BECOME MORE AND MORE RESTRICTED TO NEAR THE LOW CENTER /EASTERN
UPPER/ AND WILL ALLOW POPS TO GRADUALLY FADE NORTH DURING THE DAY.
LIKELIES LOOK GOOD FOR A TIME EARLY...HOWEVER AS THERE IS NO SUDDEN
INFLUX OF DRY/WARM AIR TO SHUT THINGS DOWN. WHILE THERE WILL BE A
GOOD DEAL OF CLOUD COVER...T92 AROUND -3C SUGGEST MID TO PERHAPS
UPPER 30S WILL AGAIN BE IN ORDER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 AM EST TUE FEB 21 2012
WEDNESDAY NIGHT THROUGH FRIDAY...CONVOLUTED PATTERN EXPECTED ACROSS
THE GREAT LAKES REGION TO WRAP UP THE WORK WEEK...WITH HONESTLY NOT
VERY HIGH CONFIDENCE IN ANY TIMING OF VARIOUS PRECIP CHANCES.
SECONDARY SHORTWAVE OF SHORT TERM MENTION ABOVE OVER THE NORTHERN
PLAINS WILL BE EXITING STAGE RIGHT WEDNESDAY EVENING...LEAVING
IMPRESSIVE PLUME OF PACIFIC JET ENERGY TO FLOOD JUST ABOUT THE
ENTIRE CONUS HEADING INTO FRIDAY. EMBEDDED WITHIN THE FLOW ARE
SEVERAL PROGGED SHORTWAVES...THOUGH THEIR PLACEMENT AND TIMING VARY
CONSIDERABLY FROM RUN TO RUN AND MODEL TO MODEL. ABOUT THE ONLY
THING THAT CAN BE SAID WITH SOME CONFIDENCE IS THAT VARIOUS MAINLY
SMALL PRECIP CHANCES WILL EXIST DURING THE LATE WEEK PERIOD...THOUGH
HIGHLY DOUBTING THE AMPLIFIED SOLUTIONS OF THE BOTH THE 21/00Z NAM
AND 20/12Z ECMWF GIVEN THE RAGING PACIFIC "FIREHOSE" JET ENERGY THAT
SHOULD EASILY KEEP THE FLOW PROGRESSIVE. INSTEAD WE APPEAR TO BE
LEFT WITH A MYRIAD OF WEAKER UPPER WAVES THAT WILL TRAVERSE A
BRIEFLY STATIONARY TIGHT THERMAL GRADIENT RESIDING OVER THE SOUTHERN
GREAT LAKES. AS SUCH...PRECIP CHANCES SHOULD BE GREATEST OVER
SOUTHERN COUNTIES...AND ENTIRELY POSSIBLE THAT NOT A WHOLE LOT
HAPPENS NORTH OF M-72. STILL...GIVEN PLENTY OF UNCERTAINTY...WILL
MAINTAIN SMALL CHANCE POPS PRETTY MUCH AREAWIDE...THOUGH WILL REMOVE
PRECIP MENTION NORTH OF M-72 ON THURSDAY. WILL ALSO KEEP PRECIP TYPE
AS ALL SNOW AT THIS POINT...THOUGH SOME HINTS EXIST THAT A RAIN/SNOW
MIX IS POSSIBLE ACROSS SOUTHERN AREAS ON THURSDAY AS STRONGER
SHORTWAVE ARRIVES. TEMPS BASICALLY TO CONTINUE ABOVE NORMAL THROUGH
THE PERIOD...MAINLY DRIVEN BY MILD OVERNIGHT LOWS.
LATER PERIODS (FRIDAY NIGHT THROUGH MONDAY)...POTENTIALLY MORE
ACTIVE WEATHER PATTERN STILL APPEARS IN THE WORKS HEADING INTO LATE
WEEKEND...AND MORE LIKELY THE FIRST HALF OF NEXT WEEK...WITH
INCREASING SIGNS OF STRONG NORTH PACIFIC JET COLLAPSING INTO SOME
DEGREE OF WESTERN CONUS TROUGHING. THIS SHOULD HAVE THE NEXT EFFECT
OF SLOWING DOWN THE WAVE TRAIN THROUGH THE CONUS...ALLOWING MORE
TIME FOR AMPLIFICATION OF VARIOUS FEATURES...AND PERHAPS SETTING UP
A SOUTHWEST FLOW REGIME FOR A TIME FROM LATER SUNDAY THROUGH MIDWEEK
(SOMETHING NOT SEEN AT ALL THIS WINTER BUT MUCH MORE TYPICAL OF A LA
NINA EPISODE). CONFIDENCE WITH ANY PARTICULAR PIECE OF GUIDANCE IS
VERY LOW...BUT THE FLAVOR OF THE FORECAST WILL REMAIN INTACT...
FEATURING INCREASING CHANCES FOR SNOW THROUGH MONDAY. AT THIS
JUNCTURE...TEMPS LOOK TO AVERAGE ABOUT NORMAL...THOUGH BIG BUST
POTENTIAL IS THERE LATE IN THE PERIOD SHOULD ANY SYSTEM AMPLIFY
SIGNIFICANT TO OUR WEST (WHICH WOULD HELP DRAG UP SOME QUITE WARM
AIR THIS WAY).
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 102 PM EST TUE FEB 21 2012
EXPECT IFR CONDITIONS TO DEVELOP AT ALL TERMINALS LATER THIS
AFTERNOON AND EARLY EVENING...IMPROVING TO MVFR OVERNIGHT.
&&
.MARINE...
ISSUED AT 333 AM EST TUE FEB 21 2012
SMALL CRAFTS ONGOING OVER ALL NEARSHORE ZONES...AND EXPECT THIS TO
CONTINUE THROUGH AT LEAST WEDNESDAY AS LOW PRESSURE TAKING SHAPE
OVER NORTHERN MINNESOTA TODAY SHIFTS OVER LAKE SUPERIOR TONIGHT WITH
SOUTHEAST WINDS SHIFTING SOUTHWEST TONIGHT. WINDS/WAVES SHOULD
SUBSIDE WEDNESDAY NIGHT AND THURSDAY AS WEAK AREA OF HIGH PRESSURE
BUILDS IN FROM THE NORTHWEST. AS THE WINDS SHIFT SOUTHWEST
TONIGHT...CAN/T COMPLETELY RULE OUT A FEW LOW-END GALES ON THE
NORTHWEST LAKE MICHIGAN COAST...BUT FLOW TRAJECTORY DOES NOT FAVOR
MUCH IN THE WAY OF COASTAL CONVERGENCE ENHANCEMENT...SO EXPECT MOST
SPOTS TO GUST TO AROUND 30KTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPB
SHORT TERM...ARNOTT
LONG TERM....LAWRENCE
AVIATION...
MARINE...ARNOTT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1255 PM EST TUE FEB 21 2012
.SYNOPSIS...
ISSUED AT 452 AM EST TUE FEB 21 2012
A COLD FRONT WILL PASS THROUGH THE AREA TODAY BRINGING A PERIOD OF
RAIN AND SNOW. THE STEADIEST PRECIPITATION SHOULD OCCUR THIS
MORNING...WITH THE MIX BECOMING LIGHTER AND MORE SCATTERED INTO THE
AFTERNOON. PORTIONS OF CENTRAL LOWER MICHIGAN MAY PICK A LIGHT
DUSTING OF SNOW...OTHERWISE LITTLE TO NO SNOW ACCUMULATION IS
EXPECTED. SCATTERED LIGHT SNOW SHOULD LINGER INTO TONIGHT BEFORE
SKIES GRADUALLY CLEAR ON WEDNESDAY.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY EVENING)
ISSUED AT 1255 PM EST TUE FEB 21 2012
OUR BAND OF SNOW HAS LIFTED OUT OF THE CWA AS OF 1230 PM. THERE IS
STILL THE AREA OF SNOW OVER CENTRAL WISCONSIN HEADING EAST WITH THE
COLD FRONT OCCASION. THE SOUTHERN EDGE OF THAT SNOW AREA HAS LIFTED
NORTH WITH TIME HOWEVER I BELIEVE THE ADDED MOISTURE FROM LAKE
MICHIGAN WILL HELP IT`S CAUSE AND AS PER THE HRRR WILL RAPIDLY
DEVELOP SOUTHWARD AS IT MOVES INTO SOUTHWEST LOWER MICHIGAN AFTER 3
PM THIS AFTERNOON. I USED THE TIMING TOOL TO FIGURE OUT WHERE IT
WOULD BE WHEN... AND IT WOULD REACH MKG BY 3 PM BUT IT WOULD NOT GET
TO LAN UNTIL 6 PM. I USED MODIFIED 15Z SREF POP TO MODEL THIS
FEATURE. BOTH THE NAM AND RUC SHOW STRONG LIFT IN THE BELOW 10000 FT
AGL WITH THE BEST LIFT NEAR 3000-5000 FT AGL. THAT IS WELL BELOW THE
DGZ BUT THE RUC SHOWS SOME OF THE DGZ IS IN THE LIFT ZONE SO THERE
JUST MAY BE SNOW SNOW WITH THIS. IN ANY EVENT IT WILL BE BRIEF...
LESS THAN 2 HOURS AT ANY ONE LOCATION.
THERE SEEMS TO BE TO MUCH DRY AIR WRAPPING IN BEHIND THE FRONT AS
THE SYSTEM LIFTS NORTHEAST FOR LAKE EFFECT TO HAVE MUCH IMPACT. EVEN
SO I HAVE CHC POP OVER THE NW CWA EVEN SO. SKIES SHOULD CLEAR FROM
SW TO NORTHEAST OVERNIGHT AS THIS DRY AIR WRAPS INTO THE AREA FROM
THE SOUTHWEST.
WEDNESDAY SHOULD SEE LITTLE IN THE WAY OF SIGNIFICANT WEATHER AS THE
SHORTWAVE RIDGE MOVES THROUGH THE AREA.
SOME ISSUES WITH THE NEXT SYSTEM... ECMWF VERSE THE GFS/NAM. SO NOT
MUCH CONFIDENCE THERE... I HAVE THE POP TOWARD THURSDAY MORNING. A
FAIR AMOUNT OF WARM AIR AHEAD OF THIS SO IF ANYTHING THIS WILL
MOSTLY BE RAIN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 452 AM EST TUE FEB 21 2012
PLENTY OF CONCERNS IN THE LONG TERM REMAIN WITH MODEL DISCREPANCIES
AND PRECIPITATION TYPE/COVERAGE THE MAIN CONCERNS.
HAVE MAINTAINED CHANCE POPS WEDNESDAY NIGHT INTO THURSDAY...BUT
CONFIDENCE IS LOW. MODELS INDICATE A SHORTWAVE TROUGH SWINGING
THROUGH THE GREAT LAKES DURING THIS TIME FRAME. THE ASSOCIATED
SURFACE LOW HAS A VARIED TRACK...WITH THE NAME BEING WELL NORTH OF
THE FORECAST AREA AND THE EUROPEAN OFF TO THE SOUTH. GIVEN MODEL
DISCREPANCIES...MADE LITTLE CHANGE. THE NAM WOULD BRING IN WARMER
AIR AND AND CHANGE MOST OF THE FORECAST AREA OVER TO RAIN.
THE SURFACE LOW MOVES INTO THE EASTERN GREAT LAKES THURSDAY NIGHT
WITH SOME LINGERING SNOW OVER LOWER MICHIGAN. CONFIDENCE CONTINUES
TO BE LOW IN THIS PERIOD AS WELL WITH LOW POSITION RANGING FROM
QUEBEC (NAM) TO SOUTHERN OHIO (EURO) AT 12Z FRIDAY.
COLDER AIR FILTERS IN FOR FRIDAY NIGHT AND SATURDAY WITH LAKE EFFECT
NEAR LAKE MICHIGAN. THE GFS PUSHES A LOW INTO THE GREAT LAKES FOR
SUNDAY AND SUNDAY NIGHT WHILE THE EURO IS DRY (LOW IN COLORADO).
LEFT POPS IN THE FORECAST FOR NOW...BUT HPC BELIEVES THE GFS IS WAY
TOO QUICK. EURO WOULD THEN BRING RAIN INTO THE AREA ON MONDAY IS A
GOOD SOUTHERLY FLOW.
BOTTOM LINE...LITTLE CONFIDENCE IN THE LONG TERM PERIOD...WITH
MULTIPLE SHORTWAVE/S TO DEAL WITH IN GENERAL UPPER TROUGHING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1255 PM EST TUE FEB 21 2012
IFR CIGS AND MVFR TO VFR VSBY COVER THE TAF SITES AT 1245 PM THIS
AFTERNOON. I EXPECT THE VSBY INCREASE TO VFR AT ALL BUT MKG WHICH IS
BY LAKE MICHIGAN THIS AFTERNOON AS THE PRECIPITATION HAS ENDED.
HOWEVER THE BAND OF SNOW OVER WISCONSIN WILL CROSS SOUTHWEST LOWER
MICHIGAN BETWEEN 20Z AND 02Z FROM WEST TO EAST AND LAST LESS THAN 2
HOURS AT ANY ONE LOCATION. QUESTIONABLE TEMPERATURES FOR ALL SNOW OR
ALL RAIN. FOR NOW I WENT WITH RAIN BUT DO NOT BE SURPRISED IF IT IS
SNOW (SEE SHORT TERM FOR DETAILS ON THIS). ONCE THE COLD FRONT
OCCLUSION COMES THROUGH EARLY THIS EVENING EXPECT RAPID IMPROVEMENT
FOR THE I-94 TAF SITES BUT IT MAY TAKE UNTIL AFTER 09Z FOR THE I-96
TAFS TO IMPROVE ABOVE MVFR.
I EXPECT SOLID VFR ALL TAF SITES WEDNESDAY FROM 12Z THROUGH AT LEAST
06Z THURSDAY.
&&
.MARINE...
ISSUED AT 452 AM EST TUE FEB 21 2012
HAVE EXPANDED THE SMALL CRAFT FOR ALL NEARSHORE ZONES STARTING 2 PM
THIS AFTERNOON. WINDS WILL PIVOT TO THE SW BEHIND THE FRONT LATER
THIS AFTERNOON. SPEEDS SHOULD APPROACH 30 KNOTS BY LATE IN THE DAY.
&&
.HYDROLOGY...
ISSUED AT 452 AM EST TUE FEB 21 2012
RIVER LEVELS ARE TO REMAIN NEARLY STEADY AND BELOW ACTION STAGE
THROUGH THE PERIOD. NO SIGNIFICANT RUNOFF IS FORECASTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EST WEDNESDAY FOR LMZ846>849.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM EST
WEDNESDAY FOR LMZ844-845.
&&
$$
SYNOPSIS...JK
SHORT TERM...WDM
LONG TERM....DUKE
AVIATION...WDM
MARINE...JK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
112 PM EST TUE FEB 21 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OUT INTO THE WESTERN ATLANTIC. A SERIES OF
UPPER LEVEL DISTURBANCES WILL MOVE THROUGH THE AREA THROUGH
WEDNESDAY...FOLLOWED BY A STRONG COLD FRONT PASSAGE ON FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM...
LATEST RUC MODEL SHOWS THICKNESSES INCREASING LATE AFTERNOON INTO
EVENING WITH THIS ENERGY REMAINING ALOFT. IT IS PRUDENT TO BACK
OFF THE 00Z THICKNESS VALUES REGARDING TEMPERATURE FORECASTS DUE
TO THIS TIMING AND ENERGY REMAINING ALOFT. MID LEVEL CLOUDINESS HAS
ARRIVED ON CUE INTO CENTRAL NORTH CAROLINA. THE CLEARING LINE
SHOULD PASS THE WESTERN PIEDMONT BEFORE NOON... EXITING TO THE
COASTAL PLAIN AT MID AFTERNOON. HOWEVER A LOOK AT UPSTREAM
TRAJECTORIES AND MOISTURE SUGGEST SOME CLOUDINESS BEHIND THE
CLEARING LINE... BUT NOT AS EXTENSIVE AS THIS MORNING. CURRENT
FORECAST OF MID TO UPPER 50S PERHAPS A TOUCH COOL... BUT THIS WILL
DEPEND ON AFTERNOON CLOUD COVER.
LOOKING AT CURRENT TEMPERATURE PROFILES AND SURFACE TEMPERATURE
FORECASTS... WIND GUSTS TO 20 MPH SHOULD HOLD OFF UNTIL EARLY
AFTERNOON.
THE QUESTION OF POSSIBLE VERY LOW STRATUS TONIGHT WILL BE THE
PROBLEM OF THE DAY... BUT WILL DELAY ANY CHANGES UNTIL ALL THE
MORNING MODELS ARE PROCESSED. ALTHOUGH SUBTLE... DECENT LOW LEVEL
ADVECTION IN THE MODELS WITH THE STRONGER WINDS OF THE NAM ATOP
THE BOUNDARY LAYER INVERSION WITH DECOUPLING MORE REALISTIC THAN
THE GFS. TEND TO FAVOR A FORECAST OF STRATUS FORMATION BUT
UNCERTAIN OF EXTENT AT THIS TIME. REGARDLESS TEMPERATURES WILL BE
MILD COMPARED TO THIS MORNING... WITH UPPER 30S TOO LOWER 40S
COMMON.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 250 AM TUESDAY...
BY WEDNESDAY A BROAD SCALE TROUGH WILL HAVE EVOLVED OVER THE
EASTERN TWO THIRDS OF THE COUNTRY WITH SEVERAL EMBEDDED FAST
MOVING PERTURBATIONS MOVING EAST ACROSS THE AREA IN THE
PROGRESSIVE ZONAL FLOW ALOFT. ONE OF THESE VORTICITY IMPULSES OF
NOTE IS FORECAST TO REACH THE SOUTHERN AND CENTRAL APPALACHIANS
AROUND 00Z THURSDAY...AND WILL THEN TRAVERSE THE CAROLINAS BY 06Z.
DPVA AND DYNAMIC COOLING/ASCENT ACCOMPANYING THE TROUGH PASSAGE
WILL STEEPEN MID AND UPPER LEVEL LAPSE RATES ACROSS THE AREA
WEDNESDAY EVENING AND ELIMINATE THE MID LEVEL CAP...WHICH SHOULD
ALLOW THE BAND OF SHOWERS TO SURVIVE EASTWARD AS THEY MOVE OFF THE
EASTERN SLOPES AND ACROSS THE AREA. UNFAVORABLE NOCTURNAL
TURNING/BOUNDARY LAYER STABILIZATION WILL IMPACT COVERAGE
HOWEVER...AND AT THIS TIME WILL CAP POPS OFF AT LOW TO SLIGHT
CHANCE...WITH HIGHEST POPS OVER THE WESTERN PIEDMONT AND ENDING
BEFORE DAYBREAK THURSDAY.
WILL SEE FULL COMPLIMENTS OF SUN ON WEDNESDAY AS THICKNESSES SOAR TO
AROUND 1350 METERS...A GOOD 20 TO 25 METERS ABOVE NORMAL. HIGHS IN
THE LOWER 60S NORTHWEST TO UPPER 60S SOUTHEAST. MILD OVERNIGHT
LOWS OF 46 TO 51.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...
MODELS HAVE COME INTO BETTER AGREEMENT OVER THE PAST 24 HOURS WITH
RESPECT TO OUR NEXT SYSTEM THAT IS EXPECTED TO IMPACT THE REGION
DURING THE FIRST PART OF THE LONG TERM PERIOD. MODELS SHOW ANOTHER
SOUTHERN STREAM UPPER LEVEL TROUGH/LOW DIGGING INTO THE SOUTHWESTERN
UNITED STATES AND NORTHERN MEXICO TUESDAY INTO WEDNESDAY AND
EVENTUALLY EJECTING EASTWARD AND AFFECTING CENTRAL NORTH CAROLINA
THURSDAY INTO FRIDAY. DURING THE SAME TIME FRAME...A NORTHERN
STREAM TROUGH WILL AMPLIFY AS IT MOVES INTO THE CENTRAL UNITED
STATES...PROMOTING SURFACE CYCLOGENESIS ACROSS THE TENNESSEE AND
OHIO VALLEY. THE ASSOCIATED SURFACE COLD FRONT IS FORECAST TO MOVE
THROUGH CENTRAL NORTH CAROLINA FRIDAY AFTERNOON AND EVENING. ALL
OF THIS WILL RESULT IN PRECIPITATION CHANCES INCREASING LATE
THURSDAY...WITH THE BEST TIME FRAME FOR SHOWERS COINCIDING WITH
THE FRONTAL PASSAGE DURING THE DAY ON FRIDAY. AHEAD OF THE
FRONT...STRONG SOUTHWESTERLY SURFACE FLOW WILL PUSH TEMPERATURES
INTO THE UPPER 60S TO LOWER 70S ACROSS AREA ON BOTH THURSDAY AND
FRIDAY. ALSO...MOISTURE WILL POOL AHEAD OF THE APPROACHING
FRONT...WITH MAXIMUM PRECIPITABLE WATER VALUES FORECAST TO RANGE
BETWEEN ONE AND ONE AND A HALF INCHES. THIS SHOULD RESULT IN
SOME WEAK INSTABILITY OVER EASTERN NORTH CAROLINA...ALTHOUGH
CURRENT FORECAST SOUNDINGS SHOW VERY MARGINAL CAPE VALUES.
NEVERTHELESS...WILL MAINTAIN THE MENTION OF A SLIGHT CHANCE OF
THUNDER ACROSS THE COASTAL PLAIN...ESPECIALLY SINCE THE FRONTAL
PASSAGE IS EXPECTED TO OCCUR DURING A FAVORABLE TIME OF DAY.
BEHIND THE FRONT...HIGH PRESSURE WILL BUILD INTO THE REGION FOR THE
WEEKEND...WITH TEMPERATURES RETURNING TO NEAR NORMAL VALUES.
ANOTHER WARM UP SHOULD COMMENCE BY THE BEGINNING OF NEXT WEEK AS
THE HIGH IS EXPECTED TO SHIFT OFFSHORE BY MONDAY AHEAD OF OUR NEXT
SYSTEM... WHICH MAY BRING INCREASING PRECIPITATION CHANCES TO THE
AREA BY AS EARLY AS LATE MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 115 PM...
VFR INTO THE NIGHT WITH SOME LOW STRATUS BEFORE SUNRISE. SOME
GUSTINESS TO AROUND 20 MPH THIS AFTERNOON. STRATUS DEVELOPING
BEFORE DAWN BUT COVERAGE IS UNCERTAIN. HAVE ELECTED TO ONLY PLACE
LOW CEILINGS WHERE CONFIDENCE IS HIGHEST... IN THE NORTHEAST AT
RALEIGH AND ROCKY MOUNT. RESTRICTIONS TO VISIBILITY MINIMAL TO
ABSENT DUE TO A LIGHT PERSISTENT BREEZE. ANY STRATUS DISSIPATES
NEAR MID MORNING AND GUSTINESS NEAR 20 MPH TO RETURN BY LATE
MORNING WEDNESDAY.
INCREASING RAIN CHANCES WITH ADVERSE AVIATION CONDITIONS ARE
EXPECTED RAIN LATE WEDNESDAY INTO WEDNESDAY NIGHT... AND AGAIN
LATE THURSDAY NIGHT INTO FRIDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CBL
LONG TERM...KRR
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1149 AM CST TUE FEB 21 2012
.UPDATE...POPS ARE ANTICIPATED TO DECREASE AS THE DAY PROGRESSES.
CURRENT RADAR TRENDS SHOW REFLECTIVITY DECREASING WITH TIME AS IT
MOVES WSW-NE. ALTHOUGH...MODELS...SPECIFICALLY HRRR AND NAM ARE
SHOWING PRECIP IN THE AFTERNOON...THE FORMER HINTING AT A CELLULAR
FORM. CURRENT PRECIP THATS FALLING OVER THE CWA HAS SWITCHED OVER
TO RAIN...EXCEPT FOR MAYBE IN THE FAR NORTHERN PART OF THE CWA.
ANY PRECIP IN THE AFTERNOON WILL BE RAIN. UPDATED THE WX AND POP
FCSTS TO REFLECT RADAR WEAKENING TREND...IN ADDITION TO HI-RES
MODEL GUIDANCE. AFTERNOON HAVE CHANCE POPS...WHICH WERE ALREADY IN
PLACE...GIVEN LOW-LEVEL WAA...CONVERGENCE...AND INCREASING LAPSE
RATES WITH TIME. CURRENT T/TD TRENDS APPEAR ON TRACK.
&&
.AVIATION/18Z TAFS/...PRECIP MAINLY CONFINED TO NORTH OF MADISON
AND MILWAUKEE RIGHT NOW. MODELS INDICATE CHANCE FOR SHOWERS THIS
AFTERNOON...MAINLY EAST OF MADISON AS UPPER TROUGH AXIS SWINGS
THROUGH. TEMPS WILL CONTINUE TO WARM INTO THE AFTERNOON...AND
MODELS SOUNDINGS SHOW THE WARM LAYER ABOUT 2 KFT DEEP...SO PRECIP
WILL PROBABLY BE MAINLY RAIN.
IFR CIGS WILL LIKELY IMPROVE TO MVFR THIS AFTERNOON. A FEW
DIFFERENT MODEL SOLUTIONS FOR CLOUDS TONIGHT...BUT OVERALL LOOKS
LIKE CIGS MAY SCATTER BY AROUND MIDNIGHT. MODEL SOUNDINGS STILL
HINTING AT SLIGHT CHANCE FOR CONVECTIVE SHOWER DEVELOPMENT TOWARD
AND INTO THIS EVENING. WILL HAVE TO MONITOR RADAR AND MODEL
TRENDS TO CONSIDER EXTENDING SLIGHT CHANCE INTO THE EVENING.
LOOKS PRETTY QUIET THEN TROUGH THE DAY WEDNESDAY. DEBATING
WHETHER OR NOT TO KEEP SLIGHT CHANCE FOR RAIN TOMORROW
AFTERNOON...AS MODELS ARE GENERALLY DRY.
&&
.PREV DISCUSSION... /ISSUED 408 AM CST TUE FEB 21 2012/
SHORT TERM...
TODAY...FORECAST CONFIDENCE MEDIUM TO HIGH
DRY AIR IN THE LOW LEVELS IS LIMITING PCPN COVERAGE OVER ERN WI AND
NE IL EARLY THIS AM BUT BELIEVE ATM WILL EVENTUALLY SATURATE AND NRN
BAND OF PCPN OVER CENTRAL IL ASSOCIATED WITH A STRONG SHORTWAVE
TROUGH AND JET STREAK SHOULD AFFECT AT LEAST THE SRN CWA LATER THIS
AM. EXPECT PCPN TO REMAIN LIGHT AS THAT IS WHAT HAS BEEN OBSERVED TO
THE SOUTH AND AS THE SHORTWAVE TROUGH TRACKS MORE TO THE SOUTH FROM
MO TO NRN OHIO. A RAIN SNOW MIX IS EXPECTED IN FAR SE WI WITH LGT
SNOW ELSEWHERE...BUT GIVEN MILD TEMPS AND LIGHT QPF...SNOW TOTALS
SHOULD REMAIN AROUND ONE HALF INCH OR LESS. THE DRY SLOT WILL ARRIVE
IN THE AFTERNOON AS CYCLOGENESIS OCCURS IN THE ARROWHEAD OF MN. FCST
SOUNDINGS DO SHOW STEEP LAPSE RATES AND SOME SKINNY CAPE THIS
AFTERNOON...THUS KEPT A SLIGHT CHANCE OF RAIN/SNOW SHOWERS.
TONIGHT...FORECAST CONFIDENCE...MEDIUM.
PRECIP WILL END BY THIS EVENING AS THE SFC LOW AND UPPER LOW REACH
EASTERN ONTARIO AND DRIER AIR AND SUBSIDENCE SETTLE INTO SOUTHERN
WI. STEEP LOW-LEVEL LAPSE RATES TUESDAY EVENING AS POCKET OF COLDER
DRIER AIR WORKS UNDER LOW. SOME MOISTURE CONVERGENCE ON THE LEADING
EDGE OF THE COLD AIR COULD LEAD TO A FEW FLURRIES...BUT NOT ENOUGH
TO REALLY MENTION IN THE FCST. SKIES SHOULD GO FROM CLOUDY TO PARTLY
CLOUDY FROM SOUTHWEST TO NORTHEAST THROUGH THE NIGHT. LOW TEMPS
EXPECTED TO DROP INTO THE UPPER 20S TOWARD WED MORNING.
WEDNESDAY...FORECAST CONFIDENCE...MEDIUM.
DRY WEATHER WEDNESDAY MORNING...THEN A SLIGHT CHANCE OF RAIN IN THE
AFTERNOON WITH WARM AIR ADVECTION AHEAD OF NEXT SHORT WAVE. 925MB
TEMPERATURES SUPPORT HIGHS IN THE LOWER 40S.
WEDNESDAY NIGHT THROUGH FRIDAY NIGHT...FORECAST CONFIDENCE LOW TO
MEDIUM.
AN UPPER TROUGH DEVELOPING OVER THE CENTRAL CONUS COULD BRING PRECIP
TO WI AS WEAK UPPER LEVEL DISTURBANCES ROLL ACROSS THE REGION. THE
MAIN BAROCLINIC ZONE WILL BE ACROSS CENTRAL IL...WHICH WILL MAKE
PRECIP CHANCES AND PRECIP TYPE QUITE UNCERTAIN. MODELS ARE ALL OVER
THE PLACE WITH TIMING AND PRECIP LOCATION. BEST CHANCE FOR PRECIP
WILL BE ACROSS SOUTHERN WI. WITH WARM BOUNDARY LAYER TEMPS...ANY
PRECIP SHOULD START OUT AS RAIN AND THEN POSSIBLY SWITCH OVER TO
SNOW FOR THE LATTER HALF OF WED NIGHT. WARM TEMPS WILL BRING PRECIP
BACK TO MAINLY RAIN ON THU.
COLD AIR ADVECTION WITH LINGERING MOISTURE AND STEEP LOW LEVEL LAPSE
RATES WILL CONTINUE THE CHANCE OF PRECIP AS SNOW THU NIGHT. CYCLONIC
FLOW WILL HANG AROUND THE UPPER GREAT LAKES REGION THROUGH
FRIDAY...SO SNOW SHOWER CHANCES WILL PERSIST THROUGH POSSIBLY FRI
EVENING.
TEMPS ON THU SHOULD BE SIMILAR TO WED IN THE LOWER 40S...THEN COOLER
IN THE MID 30S ON FRIDAY...STILL ABOVE NORMAL.
LONG TERM...
SATURDAY AND SATURDAY NIGHT...FORECAST CONFIDENCE MEDIUM.
THERE SHOULD BE A DRY PERIOD SATURDAY AND SATURDAY NIGHT WITH 500MB
RIDGING. DESPITE PARTLY CLOUDY SKIES...CONSENSUS OF MODELS SHOW MAX
TEMPS ONLY IN THE LOWER 30S...ALTHOUGH THERE IS A PRETTY BIG MODEL
SPREAD IN THE FCST TEMPS.
SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE...LOW.
MODELS CONTINUE TO BE HIGHLY VARIABLE WITH THE STRUCTURE AND TIMING
OF STRONG SHORT WAVE AND ASSOCIATED SURFACE LOW EJECTING FROM
DEEPENING WESTERN TROUGH IN THE SUNDAY/MONDAY TIME FRAME. HPC MODEL
BLEND SOLUTIONS FAVOR THE ECMWF AND ECMWF ENSEMBLES...WITH THE SFC
LOW TRACKING FROM EASTERN CO THROUGH IA AND ACROSS LAKE SUPERIOR
FROM SUN THROUGH TUE. THE GFS TRACKS THE SFC LOW STRAIGHT EAST
ACROSS THE WI/IL BORDER INTO LOWER MI. ECMWF HAS A WARMER SOLUTION
WHILE THE GFS WOULD FAVOR SNOW OR RAIN/SNOW MIX.
HUGE UNCERTAINTY IN PRECIP TYPE...BUT SOUTHERN WI SHOULD BE IN THE
TRANSITION AREA BETWEEN SNOW TO THE NORTH AND RAIN TO THE SOUTH.
THIS IS ALSO SUPPORTED BY EXPECTED MAX TEMPS.
AVIATION/12Z TAFS/...MVFR TO IFR CIGS AND VSBYS WILL BECOME
WIDESPREAD THIS AM AS THE RAIN AND SNOW OVERSPREADS THE REGION. THE
PCPN WILL MOSTLY END BY AFTERNOON WITH SOME ISOLD SHOWERS REMAINING.
VSBYS WILL IMPROVE TO VFR AS BRISK WEST WINDS AND SLIGHTLY DRIER AIR
INVADE THE REGION IN THE WAKE OF THE COLD FRONT. MVFR CIGS WILL
PREVAIL IN THE AFTERNOON AND THEN GRADUALLY DECREASE IN COVERAGE
WITH SCT CLOUD COVER EXPECTED SOMETIME THIS EVENING.
MARINE...A SMALL CRAFT ADVISORY IS IN EFFECT UNTIL 15Z WED. A COLD
FRONT OVER THE STATE OF IA EARLY THIS MORNING WILL MOVE NEWD AND
REACH LAKE MI AROUND NOON. THUS THE SELY WINDS THAT BROUGHT THE HIGH
WAVES WILL VEER TO THE WSW WITH WAVE HEIGHTS DECREASING DUE TO THE
OFFSHORE FLOW. HOWEVER BRISK WSWLY WINDS AND GUSTY WINDS WILL THEN
PREVAIL THIS AFTERNOON...TNT...AND INTO WED AM AS LOW PRESSURE
INTENSIFIES OVER LAKE SUPERIOR AND ONTARIO CANADA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 9 AM CST WEDNESDAY FOR LMZ643>646.
&&
$$
UPDATE...ET/DDV
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
WEDNESDAY THROUGH MONDAY...MRC