Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 01/11/12
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
730 PM EST TUE JAN 10 2012
.DISCUSSION...
...SHOWERS AND ISOLATED STORMS WEDNESDAY...
CURRENT-OVERNIGHT...CIRRUS SHIELD ASSOCIATED WITH THE COLD FRONT
MOVING ACROSS THE NORTH AND NORTHEAST GULF OF MEXICO WILL OVERSPREAD
CENTRAL FLORIDA DURING THE EVENING RESULTING IN A HIGH OVERCAST SKY.
AS THE FRONT ADVANCES EASTWARD...SOUTHERLY WINDS AHEAD OF THE FRONT
WILL INCREASE DUE TO THE TIGHTENING PRESSURE GRADIENT BETWEEN THE
FRONT AND THE EXITING HIGH PRESSURE SYSTEM THAT HAD BEEN IN PLACE
OVER THE SOUTHEAST STATES AND FLORIDA FOR THE PAST SEVERAL DAYS.
LATEST MSAS AND RUC SURFACE ANALYZES SHOW THE TIGHTENING GRADIENT IN
THE NORTHERN GULF QUITE WELL. LATEST MAV MOS SUGGESTING BEST WINDOW
OF OPPORTUNITY FOR STORMS WOULD BE THE AFTERNOON HOURS AS A VORT MAX
MOVES OVERHEAD.
MADE A FEW AMENDMENTS TO THE VARIOUS OVERNIGHT WIND GRIDS.
PREVIOUS
WED...THE UPPER TROUGH WILL BECOME NEGATIVELY TILTED AS IT SWINGS
NORTHEASTWARD ACROSS THE CAROLINAS. A THIN BROKEN OFF PIECE OF
VORTICITY IS STILL FORECAST TO MOVE ACROSS THE FLORIDA PENINSULA
DURING THE DAY. THE TAIL END OF AN UPPER JET (~90 KNOTS) WILL SWEEP
ACROSS NORTH FLORIDA PROVIDING DIFFLUENCE ALOFT OVER THE REGION. THE
COLD FRONT WILL MOVE ACROSS EAST CENTRAL FLORIDA LATE IN THE
DAY/EVENING. AHEAD OF IT THE LOCAL WRF_ARW9 MODEL SHOWS A BROKEN
LINE OF SHOWERS/STORMS MOVING THROUGH EAST CENTRAL FLORIDA.
DEEP SOUTHWEST FLOW WILL ALLOW PRECIPITABLE WATER VALUES TO
INCREASE TO AROUND 1.60-1.70 INCHES AHEAD OF THE FRONT. MOS
GUIDANCE CONTINUES TO GO HIGH FOR POPS AND THUS WILL KEEP
INHERITED POP GRIDS IN PLACE WITH 80 PERCENT NORTH OF A LINE FROM
KISM-KTTS AND 60 TO 70 PERCENT FURTHER SOUTHWARD THROUGH THE
TREASURE COAST. GREATEST CHANCES FOR PRECIPITATION WILL BE DURING
THE MORNING/EARLY AFTERNOON NORTH OSCEOLA COUNTY-NORTH BREVARD
COUNTY NORTHWARD AND MAINLY AFTERNOON HOURS FURTHER SOUTHWARD.
SEVERE CHANCES REMAIN LIMITED WITH MARGINAL INSTABILITY AND
SUSPECT MAIN THREATS WILL BE CLOUD TO GROUND LIGHTNING...BRIEF
HEAVY DOWNPOURS AND WIND GUSTS TO AROUND 40 MPH IN STRONGER CELLS.
MOVEMENT SHOULD BE OUT OF THE WEST-SOUTHWEST OR WEST AT 25 TO 30
MPH.
IT WILL BE A NEAR BREEZY/BREEZY DAY WITH WINDS QUICKLY VEERING TO
THE SSW/SW PAST DAYBREAK AND SPEEDS INCREASING TO 15/15-20 MPH
AREAWIDE. SKIES WILL REMAIN MOSTLY CLOUDY. MAX TEMPERATURE READINGS
ARE FORECAST IN THE MIDDLE TO UPPER 70S.
WED NIGHT... COLD FRONT WILL PUSH OFFSHORE DURING THE EVENING.
THIS WILL TAKE ANY LINGERING SHOWERS AWAY FROM THE COAST SO HAVE
ONLY SLIGHT CHANCE POPS ALONG THE SPACE/TREASURE COASTS EARLY.
DRYING/COOLING OVERNIGHT LOOKS ONLY MODEST WITH LOW LEVEL FLOW
REMAINING WESTERLY. EXPECT SOME STRATOCUMULUS TO LINGER WITH MIN
TEMPS MOSTLY IN THE MID 50S.
THU-THU NIGHT...REINFORCING COLD FRONT WILL BE APPROACHING DURING
THE DAY AND SHOULD PUSH TO THE SOUTHERN PENINSULA BY LATE NIGHT.
THE FRONT WILL HAVE LITTLE MOISTURE TO WORK WITH AND RAIN CHANCES
THU NIGHT LOOK TOO LOW TO MENTION...EXCEPT WILL CARRY SLIGHT CHANCE
POPS ACROSS THE SOUTHERN COASTAL WATERS. MAX TEMPS THU WILL
CONTINUE MILD...MOSTLY MID 70S...AND POST FRONTAL COOLING SHOULD
ARRIVE LATE...KEEPING OVERNIGHT LOWS SEASONABLE...IN THE LOW/MID
50S.
FRI-MON...(MODIFIED PREVIOUS DISCUSSION)
A HIGH PRES RIDGE WILL BUILD IN BEHIND THE SECONDARY FRONT AND
KEEP THE FRONTAL MOISTURE SUPPRESSED OVER THE FL STRAITS. MAX
TEMPS IN THE M60S/L70S ON FRI WILL CONT THRU THE WEEKEND. MIN
TEMPS WILL BE NOTICEABLY COLDER AS THE HI PRES RIDGE PUSHES
DRY/STABLE AIR INTO THE STATE. CLEAR SKIES AND LIGHT WINDS WILL
RESULT IN STRONG RADIATIONAL COOLING CONDITIONS. MIN TEMPS M/U50S
FRI MORNING WILL DROP INTO THE U30S/M40S INTERIOR AND U40S/L50S
COAST BY DAYBREAK SAT AND WILL CONT INTO EARLY NEXT WEEK.
&&
.AVIATION...
VFR THROUGH THE NIGHT. MVFR CEILINGS STARTING AROUND 12Z AT KLEE
THEN SPREADING DOWN THE FORECAST AREA THE REST OF THE MORNING. TEMPO
IFR CEILINGS AT BKN010CB LATE MORNING AND THROUGH THE AFTERNOON AS
STORMS AHEAD OF THE FRONT PUSH THROUGH EAST CENTRAL FLORIDA.
PREVIOUS
LINE OF CONVECTION FORECAST TO MOVE INTO EAST CENTRAL
FLORIDA AFTER DAYBREAK PROGRESSING ACROSS THE SPACE/TREASURE COASTS
THROUGH THE AFTERNOON. NEAR BREEZY WIND CONDITIONS AS SW WINDS
INCREASE 15/15-20 KTS THRU THE DAY. TEMPO MVFR INVOF SHRA/ISOLD
TSRA. SFC WND GUSTS 35-50 KTS POSSIBLE IN STRONGER CELLS DURING DAY
ON WED.
&&
.MARINE...
OVERNIGHT...NOAA AND SCRIPPS BUOYS RECORDING SOUTH TO SOUTHEAST
WINDS AT 5 TO 10 KNOTS AND 2 FOOT SEAS WITH A 10 TO 11 SECOND
PERIOD.
EXPECT THE WIND TO FRESHEN UP AFTER MIDNIGHT AS THE GRADIENT
TIGHTENS BETWEEN AN APPROACHING COLD FRONT OVER THE NORTH AND
NORTHEAST GULF OF MEXICO AND THE RETREATING HIGH PRESSURE SYSTEM IN
THE SOUTHWEST ATLANTIC. SHOULD BE EXPERIENCING EXERCISE CAUTION ON
THE OFFSHORE WATERS DUE TO SOUTH WINDS OVER 15 KNOTS BY SUNRISE
WEDNESDAY MORNING THE QUICKLY TO SMALL CRAFT ADVISORY CONDITIONS ON
THE OFFSHORE WATERS BY NOON.
PREVIOUS
WED...WINDS WILL VEER TO THE SSW LATE IN THE DAY WED AS THEY
INCREASE TO 20 KTS AND GUSTY OFFSHORE PAST MID MORNING. WITH THESE
GUSTY WINDS...WILL HOIST AN ADVISORY IN THE OFFSHORE LEGS. SEAS 1-2
FT NEAR SHORE WILL INCREASE TO 3-4 FT DURING THE DAY ON WED. SEAS
OFFSHORE 2-3 FT OVERNIGHT WILL INCREASE 4-5 FT THROUGH THE DAY ON
WED. WILL KEEP A SMALL THREAT FOR SHOWERS...MAINLY IN THE GULF
STREAM TONIGHT.
A COLD FRONT WILL MOVE INTO CENTRAL FLORIDA WED AFTERNOON WITH A
BROKEN LINE OF SHOWERS AND ISOLD STORMS AHEAD OF IT. OFFSHORE
MOVING STORMS (DIR OUT OF THE WSW OR W) WILL MOVE AT 25 TO 30 KTS.
ON WED...GREATEST CHANCES FOR PRECIPITATION...TO INCLUDE ISOLATED
LIGHTNING STORMS...NORTH OF THE CAPE AFTER DAYBREAK THROUGH EARLY
AFTN WITH THE TREND FOCUSING SOUTH OF HERE EARLY AFTN-EARLY
EVENING. SMALL LONG PERIOD SWELLS ~ 9 SECONDS WILL SHORTEN TO
AROUND 5 SECONDS AWAY FROM THE COAST THROUGH THE DAY WED.
WED NIGHT...GUSTY SOUTHWEST/WEST WINDS 20-25 KNOTS AHEAD/BEHIND
FRONT INDICATED...SO WILL CONTINUE ADVISORY OFFSHORE UNTIL 4 AM.
THU-FRI...WINDS WILL REMAIN WESTERLY AND SHOULD DIMINISH TO 10-15
KNOTS ON THU. THERE MAY BE A SHORT PERIOD OF GUSTY NORTHWEST
WINDS THU NIGHT INTO FRI BEHIND A REINFORCING COLD FRONT...WITH
SPEEDS AROUND 20 KNOTS.
WEEKEND...LOOKS LIKE A PROLONGED PERIOD OF NORTHWEST TO NORTH
WINDS AS A HIGH PRESSURE RIDGE SETS UP OVER THE SOUTHEAST STATES
AND GULF OF MEXICO. THE LATEST MODEL RUN IS NOT SHOWING VERY
STRONG WINDS...BUT THERE COULD BE SOME 15-20 KNOT PERIODS...SO IT
WILL NOT BE NEARLY AS GOOD FOR BOATING AS LAST WEEKEND.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FOR WINDS FROM 7 AM WEDNESDAY TO 4 AM EST
THURSDAY FOR WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD
COUNTY LINE 20 TO 60 NM OFFSHORE-WATERS FROM SEBASTIAN
INLET TO JUPITER INLET 20 TO 60 NM OFFSHORE-WATERS FROM
VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM
OFFSHORE.
&&
$$
UPDATE/AVIATION...WIMMER
IMPACT WEATHER....PENDERGRAST
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
637 PM EST TUE JAN 10 2012
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY AND MILD CONDITIONS TONIGHT.
A LOW PRESSURE SYSTEM WILL THEN MOVE INTO THE AREA FROM THE
SOUTHWEST, BRINGING RAIN TO THE UPPER OHIO VALLEY WEDNESDAY AND
WEDNESDAY NIGHT. SNOW SHOWERS AND MORE SEASONABLE TEMPERATURES ARE
EXPECTED AFTER THE COLD FRONT PASSAGE LATE ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
PRIMARY CHANGE WITH 00Z UPDATE WAS TO TWEAK SKY/TEMPERATURE
TRENDS. WITH SKIES GOING COMPLETELY CLEAR AFTER SUNSET...HAVE
KNOCKED DOWN SKY COVERAGE UNTIL MIDNIGHT. THIS WILL ALSO ALLOW
SLIGHTLY MORE RADIATIONAL COOLING TO OCCUR...WHICH COULD HAVE
IMPLICATIONS FOR PRECIPITATION TYPE ACROSS GARRETT AND TUCKER
COUNTIES WEDNESDAY MORNING. PREVIOUS DISCUSSION FOLLOWS.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A DRY WEST-NORTHWESTERLY FLOW. AT THE SURFACE, A 1018MB HIGH IS
CENTERED ACROSS WEST VIRGINIA. THIS FEATURE ALONG WITH A DEEP
LAYER OF DRY AIR ALOFT ARE ALLOWING FOR SUNNY SKIES ACROSS MUCH OF
THE AREA.
TONIGHT...THE SURFACE HIGH WILL MOVE ACROSS THE UPPER OHIO VALLEY
AND ALLOW CLEAR SKIES. CLOUD COVERAGE WILL BEGIN TO INCREASE FROM
THE SOUTHWEST TONIGHT AS CIRRUS SPILLS INTO THE AREA AHEAD OF THE
LOW ACROSS THE GULF STATES. RADIATIONAL COOLING INITIALLY TONIGHT
WILL BE COUNTERED BY THE INCREASING CLOUD COVERAGE AND WARM AIR
ADVECTION CLOSER TO DAWN ON WEDNESDAY. LOWS ARE FAIRLY CLOSE TO
MAV GUIDANCE, RANGING FROM THE UPPER 20S ALONG THE I-80 CORRIDOR
TO THE LOWER 30S ELSEWHERE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WITH 00Z UPDATE...HAVE NOT MADE ANY CHANGES TO WEDNESDAY MORNING
PERIOD OF THE FORECAST. 18Z MODELS HAVE NOT SHOWN ANYTHING THAT
WOULD REQUIRE ADJUSTING AT THIS TIME. PREVIOUS DISCUSSION FOLLOWS.
THERE IS REASONABLE MODEL AGREEMENT THAT A 500MB CLOSED LOW WILL
MOVE FROM THE TENNESSEE VALLEY ACROSS THE MID-ATLANTIC STATES
WEDNESDAY AND WEDNESDAY NIGHT THEN INTO NEW ENGLAND ON THURSDAY.
FORECAST IS CLOSEST TO A SREF/NMM-WRF/NAM4KM BLEND WITH THE CHC POPS
BEGINNING JUST AFTER 12Z FOR AREAS ALONG AND SOUTH OF THE MASON-
DIXON LINE.
THE CHALLENGE WITH THE FORECAST WILL BE HOW THE TIMING OF INITIAL
PRECIP ALIGNS WITH NEAR FREEZING TEMPS ACROSS GARRETT AND TUCKER
COUNTIES. NAM/GFS MODEL SOUNDINGS ARE SUPPORTING A FREEZING RAIN
SOUNDING WITH 3-5C WARM NOSE. THE UNCERTAINTY IS HOW FAST SURFACE
TEMPS WILL WARM. HAVE ONLY HELD ONTO A -FZRA INTO THE LATE MORNING
FOR THESE AREAS. THIS IS MENTIONED IN THE HWO WITH AROUND A TRACE
TO A FEW HUNDREDTHS OF ICE ACCUMULATION FORECASTED. AN ADVISORY
MAY BE NEEDED FOR THESE AREAS, ALTHOUGH AT THIS TIME CONFIDENCE IS
TOO LOW. OTHERWISE, WARM WEDGE OF 850MB TEMPS WARMING TO 5-6C BY
WEDNESDAY AFTERNOON ACROSS THE AREA WILL ALLOW FOR PRECIPITATION
TO BE ALL IN THE FORM OF RAIN. FOR QPF, AMOUNTS ON WEDNESDAY WILL
RANGE FROM AROUND A QUARTER OF AN INCH NORTHWEST OF PITTSBURGH TO
THREE QUARTERS OF AN INCH TO AN INCH ACROSS THE RIDGES OF PA AND
MD. WARM AIR ADVECTION THROUGHOUT THE DAY WILL ALLOW FOR TEMPS TO
WARM TO AROUND 10 DEGREES ABOVE NORMALS. HIGHS WILL RANGE FROM THE
UPPER 30S ACROSS THE EASTERN RIDGES TO NEAR 50 FOR PORTIONS OF
EASTERN OHIO AND NORTH-CENTRAL WV.
WEDNESDAY NIGHT INTO THURSDAY...NAM/ECMWF/CANADIAN ARE INDICATING
THE SURFACE LOW SPLITTING INTO A DOUBLE BARREL LOW AS IT PUSHES INTO
THE NORTHEAST. SYNOPTIC FORCING WILL SHIFT NORTHEAST OF THE AREA WITH
THE LOWS AND THE UPPER OHIO VALLEY WILL BE IN THE WARM SECTOR.
THUS, THE FORECAST IS FOR LIKELY POPS WEDNESDAY NIGHT DECREASING
TO CHANCE ON THURSDAY. A COLD FRONT ASSOCIATED WITH THE WESTERN OF
THE TWO LOWS WILL SWING ACROSS THE OHIO VALLEY ON THURSDAY AND
BEGIN TO MOVE INTO EASTERN OHIO LATE IN THE DAY. THIS WILL ALLOW
FOR ANY PRECIP TO CHANGE TO SNOW BEHIND THE FRONT. WITH THE WARM
AIR MASS STILL IN PLACE, TEMPS WILL REMAIN 10-15 DEGREES ABOVE
NORMAL.
THURSDAY NIGHT INTO FRIDAY...GFS IS FASTER THAN THE NAM WITH COLD
AIR ADVECTION AND CHANGE OVER OF PRECIP FROM RAIN TO SNOW. FORECAST IS
A BLEND OF THE TWO, PUSHING 1000-500MB 5400M THICKNESS LINE EAST OF
THE AREA AFTER 00Z AND CHANGING RAIN SHOWERS OVER TO SNOW SHOWERS
ACROSS THE AREA BY MIDNIGHT. THE INITIAL LOW THAT SHIFTED NORTHWEST
OF THE AREA WILL THEN MERGE INTO A NORTHERN STREAM UPPER LEVEL LOW
THAT WILL PUSH FROM THE GREAT LAKES INTO THE EASTERN CANADA ON
FRIDAY. THIS WILL ALLOW FOR CONTINUED STRONG COLD AIR ADVECTION.
WITH THIS FEATURE NORTH OF THE AREA, LOW-LEVEL FLOW WILL BE
WEST-SOUTHWESTERLY. COLD AIR ADVECTION SHOULD INSTIGATE SNOW
SHOWERS, ALTHOUGH EXPECT LITTLE ACCUMULATION ACROSS THE LOWLANDS.
SOME UPSLOPING WILL OCCUR ACROSS THE RIDGES THAT WOULD ALLOW FOR
ONE TO TWO INCHES OF SNOW ACCUMULATION ACROSS THERE. TEMPS WILL
BE NOTICEABLY COLDER, RANGING FROM THE UPPER TEENS ACROSS THE
EASTERN RIDGES TO THE LOWER 20S ELSEWHERE. TEMPS WILL ONLY
INCREASE A FEW DEGREES THROUGH THE DAY ON FRIDAY WITH HIGH RANGING
FROM THE LOWER 20S ACROSS THE EASTERN RIDGES TO THE MID 20S ACROSS
THE LOWLANDS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LATEST ECMWF AND GFS RUNS APPEAR TO BE IN SOMEWHAT BETTER AGREEMENT
THAN IN EARLIER RUNS...SHOWING CLOSED UPPER LOW DEPARTING NEW
ENGLAND SATURDAY AND ANOTHER SHORT WAVE TROUGH CROSSING THE GREAT
LAKES REGION SATURDAY NIGHT. EXPECT COVERAGE OF SNOW SHOWERS TO
DECREASE SATURDAY...WITH CLOUD COVER ASSOCIATED WITH SECOND UPPER
TROUGH REMAINING OVER THE REGION INTO EARLY SUNDAY.
A BUILDING SURFACE RIDGE IS EXPECTED TO PROVIDE A PERIOD OF DRY
WEATHER SUNDAY AND MONDAY...WITH TEMPERATURES MODERATING FROM BELOW
NORMAL SATURDAY TO AROUND 10 DEGREES ABOVE THE NORM MONDAY.
THE NEXT APPROACHING SYSTEM WILL PUSH A COLD FRONT TOWARD THE UPPER
OHIO VALLEY TUESDAY. TEMPERATURES SHOULD REMAIN WARM ENOUGH FOR MOST
ASSOCIATED PRECIPITATION TO FALL IN THE FORM OF RAIN TUESDAY.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
JUDGING FROM BLEND OF RECENT SREF MODEL OUTPUT, NAM MODEL PROFILES,
AND GFS LAMP, EXPECT MVFR RAIN, FROM INCOMING LOUISIANA LOW
PRESSURE, TO SPREAD NORTHEASTWARD ACROSS THE UPPER OHIO VALLEY
WEDNESDAY AFTERNOON AND NIGHT. IFR RESTRICTIONS MAY OCCUR WEDNESDAY
NIGHT AS RAIN-MOISTENED SURFACE LAYER NOCTURNALLY COOLS AND
SATURATES.
AS BEST SHOWN BY NAM MODEL PROFILES, SURFACE WINDS, FROM THE
SOUTHEAST, MAY GUST OVER 25 KTS DOWNWIND OF THE MOUNTAINS WEDNESDAY
AFTERNOON AND WEDNESDAY NIGHT, AND MAY AFFECT KMGW, KLBE, AND KDUJ.
OUTLOOK...THURSDAY THROUGH SUNDAY...
CONTINUED RESTRICTIONS LIKELY WITH RAIN SHOWERS FROM COLD FRONTAL
PASSAGE DAYTIME THURSDAY, AND POST FRONTAL COLD-POOL-INDUCED
STRATOCUMULUS AND SCATTERED SNOW SHOWERS THURSDAY NIGHT INTO LATE
SATURDAY OR SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
442 PM EST MON JAN 9 2012
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL RIDGE
FROM CA INTO ALBERTA/SASK AND A TROUGH INTO HUDSON BAY RESULTING IN
NW FLOW DONWSTREAM INTO THE WESTERN GREAT LAKES. DRY AND WARMER AIR
HAS MOVED INTO THE CWA BEHIND A MID LEVEL SHORTWAVE AND SFC TROUGH
THAT BROUGHT LIGHT SNOW TO ERN UPPER MI THIS MORNING. THE TIGHT
GRADIENT IN THE WAKE OF THE TROUGH WITH WRLY WINDS INTO THE KEWEENAW
HAS BROUGHT BLUSTERY WINDS TO THE KEWEENAW WITH SOME GUSTS IN THE 35
TO 45 MPH RANGE. THE VIS SATELLITE LOOP SHOWED MAINLY CLEAR SKIES
OVER THE AREA WHICH HAS ALLOWED TEMPS TO CLIMB INTO THE LOWER TO MID
40S OVER THE WEST HALF OF THE AREA
&&
.SHORT TERM...TONIGHT AND TUESDAY
EXPECT THAT THE WINDS WILL DIMINISH QUICKLY LATE THIS AFTERNOON AND
EVENING AS A SFC RIDGE BUILDS INTO THE AREA. SATELLITE TRENDS AND
NAM SFC-850 MB RH PROGS SUGGEST THAT LOWER LEVEL MOISTURE OVER FAR
NE MN AND NRN LAKE SUPERIOR WILL GENERALLY MOVE OFF TO THE EAST.
WITH THE THE LIGHTER WINDS AND MAINLY CLEAR SKIES SHOULD ALLOW TEMPS
TO DROP AT OR BLO DEWPOINTS...INTO THE LOWER TO MID 20S. ALTHOUGH
MID/HIGH CLOUDS MAY INCREASE WITH THE DEVELOPING WAA PATTERN...THERE
SHOULD BE ENOUGH INSOLATION TO PUSH TEMPS WELL ABOVE NORMAL.
SO...CONTINUED TO KEEP FCST MAX READINGS SEVERAL DEGREES ABOVE
SOMEWHAT CLIMATOLOGY WEIGHTED GUIDANCE...INTO THE UPPER 30S TO MID
40S.
&&
.LONG TERM (TUE NIGHT THROUGH MONDAY)...
MAIN FORECAST CONCERNS FOR MID WEEK REVOLVE AROUND THE POTENTIAL FOR
HEAVY LAKE ENHANCED SNOW NEAR LAKE SUPERIOR.
MODEL GUIDANCE BEGINS TO DIVERGE RATHER QUICKLY TUESDAY EVENING INTO
WEDNESDAY REGARDING THE EVOLUTION OF THE CLOSED LOW MOVING OVER THE
UPPER GREAT LAKES. THE NAM SEEMS TO BE THE OUTLIER WITH THE SOLUTION
BEING PROGRESSIVE AND LESS AMPLIFIED COMPARED TO THE GFS...ECMWF AND
GEM SOLUTIONS WHICH ARE MORE AMPLIFIED AND MUCH SLOWER ESPECIALLY BY
THU. HOWEVER...EVEN AMONG THOSE THREE SOLUTIONS...THERE REMAINS
SUBTLE DIFFERENCES IN THE MASS FIELDS WHICH WILL PLAY AN IMPORTANT
ROLE WHERE THE HEAVIEST SNOW FALLS WED NIGHT INTO FRIDAY. ALL THREE
OF THE MODELS CLOSE OFF THE LOW AND SLOW IT DOWN OVER THE UPPER
GREAT LAKES. HOWEVER...THE ECMWF AND THE GEM TEND TO BE THE MOST
AMPLIFIED AND FURTHEST SOUTH COMPARED TO THE GFS. WITH THAT BEING
SAID...HAVE GENERALLY OPTED TO FOLLOW A ECMWF/GEM BLEND THROUGH THE
PERIOD.
ON TUESDAY NIGHT...EXPECT THE SURFACE LOW TO MOVE FROM THE CANADIAN
PRAIRIES TO WESTERN UPPER MICHIGAN BY WED MORNING. WILL BE TOUGH FOR
ANY PCPN TO FALL TUE NIGHT AHEAD OF THE SYSTEM WITH SYSTEM BEING OF
PACIFIC ORIGIN AND THE BEST MOISTURE BEING ROBBED BY THE SOUTHERN
STREAM SYSTEM OVER THE OHIO VALLEY. SOUTH-SOUTHWEST LOW LEVEL FLOW
WILL AHEAD OF THE SYSTEM WILL ALLOW FOR MILD TEMPS TUE NIGHT WITH
STRATUS POSSIBLE AS LOW LEVEL DEW POINTS INCREASE. HOWEVER...WITH
THE VERY DRY AIRMASS ALOFT ANY PCPN WILL NOT DEVELOP UNTIL WEDNESDAY
BEHIND THE LOW. THE LOW LEVEL STRATUS MAY SERVE AS A CATALYST FOR
DRIZZLE OR FREEZING DRIZZLE...AND IN FACT THE MODEL PROFILES FROM
THE NAM SUGGEST ESPECIALLY IN NORTH CENTRAL UPPER MICHIGAN THIS IS
POSSIBLE. HOWEVER...THE GFS IS NOT AS AGGRESSIVE IN THE LOW LEVEL
MOISTURE SO HAVE OPTED TO KEEP THIS OUT OF THE FORECAST FOR NOW.
THE ECMWF SHOWS THE LOW SLOWLY PASSING OVER OR JUST TO THE SOUTH OF
THE AREA ON WEDNESDAY AS THE UPPER LOW DIGS INTO THE NORTHERN MS
VLY. AS THE LOW MOVES EAST...COLDER AIR ALOFT MOVES ACROSS THE AREA.
SINCE MOST OF THE MOISTURE WILL LIKELY BE ASSOCIATED WITH THE
DEFORMATION AXIS TO THE NORTH AND WEST OF THE LOW...AND GIVEN THE
LOW WET BULB ZERO LEVELS...THE EXPECTATION IS THAT ANY PCPN WILL
FALL AS SNOW STARTING LATE WED MORNING ACROSS THE WEST THEN
EXPANDING EAST BY WED EVENING. LAKE EFFECT/ENHANCED SNOW WILL ALSO
DEVELOP ACROSS WESTERN UPPER MICHIGAN WED AFTN IN RESPONSE TO THE
NORTHWEST FLOW AND COLDER TEMPS ALOFT. WITH THIS BEING SAID...HAVE
OPTED TO MAINTAIN LIKELY POPS ACROSS THE WEST AND CHANCE POPS EAST.
DUE TO THE SOUTH FLOW NEAR LAKE MICHIGAN AND WARMER TEMPS
ALOFT...WILL KEEP A MENTION OF RAIN NEAR LAKE MICHIGAN THROUGH WED
EVENING BEFORE THE COLDER AIR ARRIVES.
LES WILL INCREASE IN COVERAGE AND INTENSITY WED NIGHT AND ESPECIALLY
ON THURSDAY DOWNWIND OF LAKE SUPERIOR. STILL SOME UNCERTAINTY OF THE
EXACT PLACEMENT OF THE HEAVIEST LES...BUT THE ECMWF AND THE GEM
WOULD IMPLY A MORE NORTHERLY BOUNDARY LAYER FLOW WHICH WOULD BRING
HEAVY SNOW INTO MUCH OF NORTHERN UPPER MICHIGAN. IN FACT...IF THE
ECMWF VERIFIES...THE FLOW THROUGH 700MB WILL BECOME NNE AS THE UPPER
LOW ROTATES INTO LOWER MICHIGAN ON THURSDAY INTO THU NIGHT WHILE THE
SFC LOW DEEPENS. THIS TYPE OF SCENARIO WOULD IMPLY A SIGNIFICANT
SNOWFALL FOR THE HIGHLANDS OF MARQUETTE COUNTY AS WELL...ESPECIALLY
SINCE THE ECMWF SUGGESTS SYNOPTIC SUPPORT WITH THE UPPER TROUGH
OVERHEAD. WILL CONTINUE WITH CATEGORICAL OR HIGH LIKELY POPS FOR
ALL AREAS IMMEDIATELY DOWNWIND OF LAKE SUPERIOR THU INTO THU NIGHT.
THE LOW FINALLY STARTS TO MOVE EAST ON FRIDAY ALLOWING ANY REMAINING
LES TO DIMINISH BY EVENING. QUIET WEATHER ON SATURDAY AS WEAK HIGH
PRESSURE RIDGE BUILDS ACROSS THE REGION BEFORE AN ALBERTA CLIPPER
TYPE SYSTEM ARRIVES SUNDAY. BEST MOISTURE REMAINS NORTH OF THE AREA
AND HAVE OPTED TO CONFINE LOW CHANCE POPS TO NEAR LAKE SUPERIOR.
TEMPS WILL REMAIN WELL ABOVE NORMAL TUE NIGHT INTO WED BEFORE
FALLING 10-20 DEGREES ON THURSDAY. ALTHOUGH THE BEST COLD AIR MAY
STAY WEST OF THE AREA...TEMPS WILL STILL STRUGGLE TO RISE MUCH ON
THURSDAY. WILL GO WITH TEMPS IN THE TEENS WEST AND MID 20S EAST.
CONTINUED COLD ON FRIDAY BEFORE SOME SLIGHT WARMING FOR THE WEEKEND
INTO MONDAY. HOWEVER...TEMPERATURES WILL REMAIN AT OR SLIGHTLY BELOW
NORMAL.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
EXPECT PREVAILING VFR CONDITIONS FOR MOST OF THE FCST PERIOD.
SATELLITE AND SFC OBS UPSTREAM SUGGEST THAT UPSLOPE WRLY FLOW MAY
BRING SOME MVFR CIGS INTO THE AREA THIS AFTERNOON.
HOWEVER...CONFIDENCE IS LOW WITH THE TIMING/DEVELOPMENT OF THE LOWER
CLOUDS. OTHERWISE...VERY GUSTY WEST WINDS AT KCMX WILL DIMINISH THIS
EVENING AS A RIDGE BUILDS TOWARD THE AREA AND THE GRADIENT WEAKENS.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
GALE FORCE WEST WINDS OVER THE EAST HALF OF THE LAKE WILL DIMINISH
BY THIS EVENING AS HIGH PRESSURE BUILDS TOWARD THE REGION AND THE
GRADIENT WEAKENS. WINDS WILL DIMINISH BLO 20 KTS BY TUESDAY MORNING
WITH A WEAKENING PRESSURE GRADIENT...BUT WILL INCREASE OUT OF THE
N-NW WEDNESDAY AFTERNOON INTO FRIDAY AS MUCH COLDER SPREADS ACROSS
THE REGION AND THE PRES GRADIENT TIGHTENS IN THE WAKE OF A DEEPENING
LOW PRESSURE SYSTEM TO OUR EAST. NRLY WINDS SHOULD REACH GALE GALE
FORCE THU INTO FRI WITH MODERATE TO HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ265>267.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1215 PM EST MON JAN 9 2012
LATEST UPDATE...AVIATION...
.SYNOPSIS...(427 AM EST MON JAN 9 2012)
A WEAK TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE AREA TODAY
RESULTING IN AN INCREASE IN CLOUDS AND A SLIGHT CHANCE OF RAIN OR
SNOW NORTH OF M-46. COLDER WEATHER WILL RETURN THURSDAY THROUGH THE
WEEKEND. ACCUMULATING LAKE EFFECT SNOWS ARE POSSIBLE THURSDAY
THROUGH THE WEEKEND.
&&
.SHORT TERM...(427 AM EST MON JAN 9 2012)
(TODAY THROUGH WEDNESDAY)
FORECAST CONCERNS ARE MINIMAL AGAIN TODAY. A WEAK TROUGH OF LOW
PRESSURE WILL MOVE ACROSS THE REGION TODAY. REGIONAL RADAR ALREADY
SHOWS SOME LIGHT RETURNS OVER WISCONSIN MOVING SOUTHEAST. ECMWF HAS
BEEN PRETTY CONSISTENT OVER THE PAST COUPLE OF DAYS SHOWING SOME
LIGHT PCPN CLIPPING THE NRN CWA. THE SREF ALSO SUPPORTS IT. HOWEVER
THE HRRR DOESN/T. I THINK THE THREAT OF MIXED PCPN OVER THE NRN CWA
IS WORTH A SLIGHT CHC AFTER 15Z OR SO. BETWEEN M-46 AND US-10 THE
PCPN WILL LIKELY BE RAIN IF WE SEE ANYTHING AT ALL.
SOME WEAK RIDGING WILL MOVE OVER THE LAKES TONIGHT AND TUESDAY
RESULTING IN PT CLDY SKIES AND DRY WX. ANOTHER CLIPPER WILL MOVE
SOUTHEAST FROM THE NRN PLAINS TOWARD LAKE SUPERIOR WEDNESDAY AS THE
SAME TIME A SRN STREAM SYSTEM IS MOVING ENE ACROSS THE TENNESSEE
VALLEY. ATTM IT APPEARS AS THOUGH THE SRN STREAM SYSTEM WILL BE TOO
FAR SOUTH TO RESULT IN PCPN OVER THE CWA. MOST OF THE WX ASSOCIATED
WITH THE CLIPPER WILL BE POST FRONTAL AND ARRIVE EITHER VERY LATE
WEDNESDAY AFTERNOON OR WEDNESDAY EVENING. THE COLD FRONT...BRINGING
A DECENT SHOT OF ARCTIC AIR...WILL MOVE ACROSS THE CWA WEDNESDAY
AFTERNOON.
&&
.LONG TERM...(427 AM EST MON JAN 9 2012)
(WEDNESDAY NIGHT THROUGH SUNDAY)
A PERIOD OF POTENTIALLY ACTIVE WINTER WEATHER LOOKS TO BE UNFOLDING
FOR LATE THIS WEEK INTO NEXT WEEKEND. MODELS HAVE BEEN CONSISTENT IN
SHOWING A DEEP LONGWAVE TROUGH BEING CARVED OUT OVER THE GREAT LAKES
REGION... AND RECENT SOLUTIONS ARE NOW HINTING THAT IT MAY HANG
AROUND FOR SEVERAL DAYS. THIS MEANS A PERIOD OF BELOW NORMAL
TEMPERATURES AND LAKE EFFECT SNOW CAN BE EXPECTED...WHICH HAS BEEN A
RARITY SO FAR THIS WINTER.
THE COLD AIR...H8 TEMPS OF -12C TO -16C...IS STILL PROGGED TO SWEEP
IN ON THURSDAY AND WILL HAVE LIKELY POPS IN THE WRN HALF OF THE CWFA
AS LAKE EFFECT COMMENCES. HOWEVER IT/S IMPORTANT TO NOTE THAT THE
MODELS ARE HANDLING THE H5 TROUGH EVOLUTION/PROGRESSION AND
ASSOCIATED SFC PRESSURE PATTERN SOMEWHAT DIFFERENTLY.
IF THE H5 TROUGH PROGRESSION IS SLOWED DUE TO CONTINUED DIGGING
UPSTREAM... THE SFC PATTERN COULD REMAIN LOOSE AND BAGGY ON
THURSDAY. THAT COULD EASILY DELAY THE ONSET OF THE BEST COLD AIR
INTRUSION UNTIL THURSDAY NIGHT AND FRIDAY.
EXACT WIND DIRECTION AND SUBSEQUENT LOCATION/ORIENTATION OF HEAVIEST
SNOW BANDS IS ALSO A BIT UNCLEAR AT THIS TIME SINCE IT WILL DEPEND
ON THE EVENTUAL POSITION/STRENGTH OF THE SFC LOW. EXTENT OF LAKE
AGGREGATE INDUCED SFC TROUGHING WILL ALSO BE A FACTOR IN BEHAVIOR OF
THE WINDS AND SNOW BANDS. INVERSION HEIGHTS/CONVECTIVE DEPTH SHOULD
BE DEEP THURSDAY NIGHT INTO FRIDAY WITH THE UPR LOW OVERHEAD.
THERE APPEARS TO BE GROWING SUPPORT FROM NUMERICAL GUIDANCE THAT
CLIPPER DISTURBANCES DIVING DOWN FROM THE NORTHWEST WILL HELP TO
REINFORCE THE TROUGHING OVER THE GREAT LAKES REGION NEXT WEEKEND.
THIS SYNOPTIC PATTERN IMPLIES THAT ADDITIONAL...PERHAPS FREQUENT...
EPISODES OF LAKE EFFECT/ENHANCED SNOWFALLS ARE POSSIBLE.
&&
.AVIATION...(1215 PM EST MON JAN 9 2012)
SW WINDS WILL CONTINUE TO GRADUALLY RAMP UP TO 15 TO 20 KTS WITH
GUSTS TO 25 KTS THIS AFTN/EARLY EVE. HIGHER GUSTS AROUND 30 KTS ARE
LIKELY AT KMKG. SKIES SHOULD BECOME MOSTLY CLEAR WITH DIMINISHING
WINDS OVERNIGHT. THIS MAY LEAD TO SOME PATCHY MVFR LIGHT FOG DURING
THE EARLY MORNING HRS TUE. OTHERWISE VFR CONDITIONS ANTICIPATED THRU
THE NEXT 24 HRS WITH EXTENSIVE CLEARING/WINDS UNDER 10 KTS TUE.
&&
.MARINE...(427 AM EST MON JAN 9 2012)
STARTED THE GALES A LITTLE EARLY TO AVOID DOUBLE HEADLINES. WINDS
WILL RAMP UP THIS MORNING AND HIT THEIR PEAK BY EARLY AFTERNOON.
ADDED A SCA SOUTH OF GRAND HAVEN ALSO DUE TO THE INCREASE IN WINDS
AND RESULTING HIGHER WAVES.
&&
.HYDROLOGY...(427 AM EST MON JAN 9 2012)
NO HYDRO ISSUES. COLDER AIR WILL RETURN LATER IN THE WEEK BUT WON/T
STAY AROUND LONG ENOUGH TO RESULT IN ICE BUILD UP.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING NORTH OF GRAND HAVEN TODAY.
SMALL CRAFT ADVISORY SOUTH OF GRAND HAVEN THROUGH TONIGHT.
&&
$$
SYNOPSIS: 93
SHORT TERM: 93
LONG TERM: MEADE
AVIATION: LAURENS
MARINE: 93
HYDROLOGY: 93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
715 AM EST MON JAN 9 2012
LATEST UPDATE...AVIATION...
.SYNOPSIS...(427 AM EST MON JAN 9 2012)
A WEAK TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE AREA TODAY
RESULTING IN AN INCREASE IN CLOUDS AND A SLIGHT CHANCE OF RAIN OR
SNOW NORTH OF M-46. COLDER WEATHER WILL RETURN THURSDAY THROUGH THE
WEEKEND. ACCUMULATING LAKE EFFECT SNOWS ARE POSSIBLE THURSDAY
THROUGH THE WEEKEND.
&&
.SHORT TERM...(427 AM EST MON JAN 9 2012)
(TODAY THROUGH WEDNESDAY)
FORECAST CONCERNS ARE MINIMAL AGAIN TODAY. A WEAK TROUGH OF LOW
PRESSURE WILL MOVE ACROSS THE REGION TODAY. REGIONAL RADAR ALREADY
SHOWS SOME LIGHT RETURNS OVER WISCONSIN MOVING SOUTHEAST. ECMWF HAS
BEEN PRETTY CONSISTENT OVER THE PAST COUPLE OF DAYS SHOWING SOME
LIGHT PCPN CLIPPING THE NRN CWA. THE SREF ALSO SUPPORTS IT. HOWEVER
THE HRRR DOESN/T. I THINK THE THREAT OF MIXED PCPN OVER THE NRN CWA
IS WORTH A SLIGHT CHC AFTER 15Z OR SO. BETWEEN M-46 AND US-10 THE
PCPN WILL LIKELY BE RAIN IF WE SEE ANYTHING AT ALL.
SOME WEAK RIDGING WILL MOVE OVER THE LAKES TONIGHT AND TUESDAY
RESULTING IN PT CLDY SKIES AND DRY WX. ANOTHER CLIPPER WILL MOVE
SOUTHEAST FROM THE NRN PLAINS TOWARD LAKE SUPERIOR WEDNESDAY AS THE
SAME TIME A SRN STREAM SYSTEM IS MOVING ENE ACROSS THE TENNESSEE
VALLEY. ATTM IT APPEARS AS THOUGH THE SRN STREAM SYSTEM WILL BE TOO
FAR SOUTH TO RESULT IN PCPN OVER THE CWA. MOST OF THE WX ASSOCIATED
WITH THE CLIPPER WILL BE POST FRONTAL AND ARRIVE EITHER VERY LATE
WEDNESDAY AFTERNOON OR WEDNESDAY EVENING. THE COLD FRONT...BRINGING
A DECENT SHOT OF ARCTIC AIR...WILL MOVE ACROSS THE CWA WEDNESDAY
AFTERNOON.
&&
.LONG TERM...(427 AM EST MON JAN 9 2012)
(WEDNESDAY NIGHT THROUGH SUNDAY)
A PERIOD OF POTENTIALLY ACTIVE WINTER WEATHER LOOKS TO BE UNFOLDING
FOR LATE THIS WEEK INTO NEXT WEEKEND. MODELS HAVE BEEN CONSISTENT IN
SHOWING A DEEP LONGWAVE TROUGH BEING CARVED OUT OVER THE GREAT LAKES
REGION... AND RECENT SOLUTIONS ARE NOW HINTING THAT IT MAY HANG
AROUND FOR SEVERAL DAYS. THIS MEANS A PERIOD OF BELOW NORMAL
TEMPERATURES AND LAKE EFFECT SNOW CAN BE EXPECTED...WHICH HAS BEEN A
RARITY SO FAR THIS WINTER.
THE COLD AIR...H8 TEMPS OF -12C TO -16C...IS STILL PROGGED TO SWEEP
IN ON THURSDAY AND WILL HAVE LIKELY POPS IN THE WRN HALF OF THE CWFA
AS LAKE EFFECT COMMENCES. HOWEVER IT/S IMPORTANT TO NOTE THAT THE
MODELS ARE HANDLING THE H5 TROUGH EVOLUTION/PROGRESSION AND
ASSOCIATED SFC PRESSURE PATTERN SOMEWHAT DIFFERENTLY.
IF THE H5 TROUGH PROGRESSION IS SLOWED DUE TO CONTINUED DIGGING
UPSTREAM... THE SFC PATTERN COULD REMAIN LOOSE AND BAGGY ON
THURSDAY. THAT COULD EASILY DELAY THE ONSET OF THE BEST COLD AIR
INTRUSION UNTIL THURSDAY NIGHT AND FRIDAY.
EXACT WIND DIRECTION AND SUBSEQUENT LOCATION/ORIENTATION OF HEAVIEST
SNOW BANDS IS ALSO A BIT UNCLEAR AT THIS TIME SINCE IT WILL DEPEND
ON THE EVENTUAL POSITION/STRENGTH OF THE SFC LOW. EXTENT OF LAKE
AGGREGATE INDUCED SFC TROUGHING WILL ALSO BE A FACTOR IN BEHAVIOR OF
THE WINDS AND SNOW BANDS. INVERSION HEIGHTS/CONVECTIVE DEPTH SHOULD
BE DEEP THURSDAY NIGHT INTO FRIDAY WITH THE UPR LOW OVERHEAD.
THERE APPEARS TO BE GROWING SUPPORT FROM NUMERICAL GUIDANCE THAT
CLIPPER DISTURBANCES DIVING DOWN FROM THE NORTHWEST WILL HELP TO
REINFORCE THE TROUGHING OVER THE GREAT LAKES REGION NEXT WEEKEND.
THIS SYNOPTIC PATTERN IMPLIES THAT ADDITIONAL...PERHAPS FREQUENT...
EPISODES OF LAKE EFFECT/ENHANCED SNOWFALLS ARE POSSIBLE.
&&
.AVIATION...(715 AM EST MON JAN 9 2012)
SOME MVFR CIGS HAVE BEEN MOVING IN OFF LAKE MICHIGAN EARLY THIS
MORNING... BUT COVERAGE HAS BEEN PRIMARILY LIMITED TO SCATTERED.
SOME BKN MVFR CIGS ARE STILL POSSIBLE THROUGH NOON BEFORE THE
STRONGER WARM ADVECTION INITIATES THIS AFTERNOON. OTHERWISE VFR IS
EXPECTED TODAY AND TONIGHT. ANY LIGHT PCPN WITH THE APCHG TROUGH
SHOULD STAY NORTH OF THE SRN MI TAF SITES.
THE MAIN AVIATION ISSUE TODAY WILL BE THE SOUTHWEST SFC WINDS WHICH
ARE EXPECTED TO BECOME STRONG AND GUSTY AFTER 15Z OR SO. THOSE WINDS
WILL DECREASE TONIGHT AFTER 00Z.
&&
.MARINE...(427 AM EST MON JAN 9 2012)
STARTED THE GALES A LITTLE EARLY TO AVOID DOUBLE HEADLINES. WINDS
WILL RAMP UP THIS MORNING AND HIT THEIR PEAK BY EARLY AFTERNOON.
ADDED A SCA SOUTH OF GRAND HAVEN ALSO DUE TO THE INCREASE IN WINDS
AND RESULTING HIGHER WAVES.
&&
.HYDROLOGY...(427 AM EST MON JAN 9 2012)
NO HYDRO ISSUES. COLDER AIR WILL RETURN LATER IN THE WEEK BUT WON/T
STAY AROUND LONG ENOUGH TO RESULT IN ICE BUILD UP.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING NORTH OF GRAND HAVEN TODAY.
SMALL CRAFT ADVISORY SOUTH OF GRAND HAVEN THROUGH TONIGHT.
&&
$$
SYNOPSIS: 93
SHORT TERM: 93
LONG TERM: MEADE
AVIATION: MEADE
MARINE: 93
HYDROLOGY: 93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
427 AM EST MON JAN 9 2012
LATEST UPDATE...ALL BUT AVIATION...
.SYNOPSIS...(427 AM EST MON JAN 9 2012)
A WEAK TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE AREA TODAY
RESULTING IN AN INCREASE IN CLOUDS AND A SLIGHT CHANCE OF RAIN OR
SNOW NORTH OF M-46. COLDER WEATHER WILL RETURN THURSDAY THROUGH THE
WEEKEND. ACCUMULATING LAKE EFFECT SNOWS ARE POSSIBLE THURSDAY
THROUGH THE WEEKEND.
&&
.SHORT TERM...(427 AM EST MON JAN 9 2012)
(TODAY THROUGH WEDNESDAY)
FORECAST CONCERNS ARE MINIMAL AGAIN TODAY. A WEAK TROUGH OF LOW
PRESSURE WILL MOVE ACROSS THE REGION TODAY. REGIONAL RADAR ALREADY
SHOWS SOME LIGHT RETURNS OVER WISCONSIN MOVING SOUTHEAST. ECMWF HAS
BEEN PRETTY CONSISTENT OVER THE PAST COUPLE OF DAYS SHOWING SOME
LIGHT PCPN CLIPPING THE NRN CWA. THE SREF ALSO SUPPORTS IT. HOWEVER
THE HRRR DOESN/T. I THINK THE THREAT OF MIXED PCPN OVER THE NRN CWA
IS WORTH A SLIGHT CHC AFTER 15Z OR SO. BETWEEN M-46 AND US-10 THE
PCPN WILL LIKELY BE RAIN IF WE SEE ANYTHING AT ALL.
SOME WEAK RIDGING WILL MOVE OVER THE LAKES TONIGHT AND TUESDAY
RESULTING IN PT CLDY SKIES AND DRY WX. ANOTHER CLIPPER WILL MOVE
SOUTHEAST FROM THE NRN PLAINS TOWARD LAKE SUPERIOR WEDNESDAY AS THE
SAME TIME A SRN STREAM SYSTEM IS MOVING ENE ACROSS THE TENNESSEE
VALLEY. ATTM IT APPEARS AS THOUGH THE SRN STREAM SYSTEM WILL BE TOO
FAR SOUTH TO RESULT IN PCPN OVER THE CWA. MOST OF THE WX ASSOCIATED
WITH THE CLIPPER WILL BE POST FRONTAL AND ARRIVE EITHER VERY LATE
WEDNESDAY AFTERNOON OR WEDNESDAY EVENING. THE COLD FRONT...BRINGING
A DECENT SHOT OF ARCTIC AIR...WILL MOVE ACROSS THE CWA WEDNESDAY
AFTERNOON.
&&
.LONG TERM...(427 AM EST MON JAN 9 2012)
(WEDNESDAY NIGHT THROUGH SUNDAY)
A PERIOD OF POTENTIALLY ACTIVE WINTER WEATHER LOOKS TO BE UNFOLDING
FOR LATE THIS WEEK INTO NEXT WEEKEND. MODELS HAVE BEEN CONSISTENT IN
SHOWING A DEEP LONGWAVE TROUGH BEING CARVED OUT OVER THE GREAT LAKES
REGION... AND RECENT SOLUTIONS ARE NOW HINTING THAT IT MAY HANG
AROUND FOR SEVERAL DAYS. THIS MEANS A PERIOD OF BELOW NORMAL
TEMPERATURES AND LAKE EFFECT SNOW CAN BE EXPECTED...WHICH HAS BEEN A
RARITY SO FAR THIS WINTER.
THE COLD AIR...H8 TEMPS OF -12C TO -16C...IS STILL PROGGED TO SWEEP
IN ON THURSDAY AND WILL HAVE LIKELY POPS IN THE WRN HALF OF THE CWFA
AS LAKE EFFECT COMMENCES. HOWEVER IT/S IMPORTANT TO NOTE THAT THE
MODELS ARE HANDLING THE H5 TROUGH EVOLUTION/PROGRESSION AND
ASSOCIATED SFC PRESSURE PATTERN SOMEWHAT DIFFERENTLY.
IF THE H5 TROUGH PROGRESSION IS SLOWED DUE TO CONTINUED DIGGING
UPSTREAM... THE SFC PATTERN COULD REMAIN LOOSE AND BAGGY ON
THURSDAY. THAT COULD EASILY DELAY THE ONSET OF THE BEST COLD AIR
INTRUSION UNTIL THURSDAY NIGHT AND FRIDAY.
EXACT WIND DIRECTION AND SUBSEQUENT LOCATION/ORIENTATION OF HEAVIEST
SNOW BANDS IS ALSO A BIT UNCLEAR AT THIS TIME SINCE IT WILL DEPEND
ON THE EVENTUAL POSITION/STRENGTH OF THE SFC LOW. EXTENT OF LAKE
AGGREGATE INDUCED SFC TROUGHING WILL ALSO BE A FACTOR IN BEHAVIOR OF
THE WINDS AND SNOW BANDS. INVERSION HEIGHTS/CONVECTIVE DEPTH SHOULD
BE DEEP THURSDAY NIGHT INTO FRIDAY WITH THE UPR LOW OVERHEAD.
THERE APPEARS TO BE GROWING SUPPORT FROM NUMERICAL GUIDANCE THAT
CLIPPER DISTURBANCES DIVING DOWN FROM THE NORTHWEST WILL HELP TO
REINFORCE THE TROUGHING OVER THE GREAT LAKES REGION NEXT WEEKEND.
THIS SYNOPTIC PATTERN IMPLIES THAT ADDITIONAL...PERHAPS FREQUENT...
EPISODES OF LAKE EFFECT/ENHANCED SNOWFALLS ARE POSSIBLE.
&&
.AVIATION...(1240 AM EST MON JAN 9 2012)
LITTLE CHANGE FROM THE PREVIOUS TAFS AT 00Z. STILL EXPECTING A
PERIOD OF MVFR CEILINGS TO DEVELOP OVERNIGHT OFF OF LAKE MICHIGAN
PRIMARILY AFFECTING KGRR AND KMKG. THERE WILL LIKELY BE A PERIOD OF
SOME MVFR CEILINGS BETWEEN 14Z AND 18Z AT THE OTHER TAF SITES AS
WELL. OTHERWISE VFR CONDITIONS ARE EXPECTED.
SOUTHWEST WINDS WILL BE STRONG...IN THE 15-30 KNOT RANGE FROM 15Z TO
23Z ON MONDAY.
&&
.MARINE...(427 AM EST MON JAN 9 2012)
STARTED THE GALES A LITTLE EARLY TO AVOID DOUBLE HEADLINES. WINDS
WILL RAMP UP THIS MORNING AND HIT THEIR PEAK BY EARLY AFTERNOON.
ADDED A SCA SOUTH OF GRAND HAVEN ALSO DUE TO THE INCREASE IN WINDS
AND RESULTING HIGHER WAVES.
&&
.HYDROLOGY...(427 AM EST MON JAN 9 2012)
NO HYDRO ISSUES. COLDER AIR WILL RETURN LATER IN THE WEEK BUT WON/T
STAY AROUND LONG ENOUGH TO RESULT IN ICE BUILD UP.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING NORTH OF GRAND HAVEN TODAY.
SMALL CRAFT ADVISORY SOUTH OF GRAND HAVEN THROUGH TONIGHT.
&&
$$
SYNOPSIS: 93
SHORT TERM: 93
LONG TERM: MEADE
AVIATION: DUKE
MARINE: 93
HYDROLOGY: 93
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1034 AM EST MON JAN 9 2012
.SYNOPSIS...
WEAK DISTURBANCE BRINGS LIGHT RAIN TO MAINLY THE SOUTHERN MOUNTAINS
MONDAY. HIGH PRESSURE TUESDAY. LOW PRESSURE WEDNESDAY. COLDER AIR
ARRIVES ON THURSDAY ON GUSTY WINDS AND LASTS INTO WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...UPDATED
CALLS OUT TO MTN COUNTIES THIS MORNING REVEALED -RA FALLING ACROSS
SOME OF THE SUSPECT AREAS...IE EASTERN RALEIGH...FAYETTE. -SN WAS
FALLING IN POCAHONTAS. RUC SEEMS TO SHOW THIS SHARP BOUNDARY TO
DEEPER COLD AIR AND USED THIS AND CURRENT OBS TO BASE UPDATED FCST
ON. CURRENT SFC TMPS RUNNING 29-30F ACROSS POCAHONTAS AND EASTERN
RANDOLPH.
A MORE SUBSTANTIAL AREA OF PCPN NOTED ACROSS EASTERN KY...NOW
SLIDING E INTO SOUTHERN WV. THIS IS IN ASSOCIATION WITH SOME
INCREASED ISENTROPIC LIFT WITH WAVE PASSING THRU. HAVE THIS TIMED
TO REACH CENTRAL MTNS 16-17Z. RUC SOUNDINGS INDICATED ENOUGH
WARMING ALOFT BY THIS TIME TO TRANSITION ANY SN OVER TO MORE OF A
FRZ RAIN AND SLEET SCENARIO ACROSS GREENBRIER VALLEY...WITH A COLD
RAIN PERHAPS ON THE RIDGE TOPS. WHERE THE COLDER AIR IS DEEPER
ACROSS RANDOLPH...THINK PCPN WILL STRUGGLE TO REACH THE GROUND AS
DEEPER MOISTURE LIES JUST TO SOUTH. GIVEN THIS...WILL EXTEND TIME
OF ADV UNTIL 18Z FOR POCAHONTAS AND LET WEBSTER AND RANDOLPH
EXPIRE. WILL ALLOW FOR UP TO AN INCH OF SN IN POCAHONTAS BEFORE
THE TRANSITION AND A HUNDRETH OR TWO OF ICE WITH SOME SLEET 16-18Z.
ELSEWHERE...SOME -RA OVER THE COAL FIELDS AND SOUTHERN MTNS WITH
MAYBE A FEW SLEET PELLETS THROWN IN. KEEPING IT DRY NORTH OF I64
CORRIDOR OVER THE LOWLANDS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE DRIFTS TO THE MID ATLANTIC COAST WHILE CLOSED LOW OVER
THE DEEP SOUTH MAKES A TURN NORTHEASTWARD INTO THE APPALACHIANS.
MODELS HAVE A FAIRLY GOOD HANDLE ON THE TIMING OF THE RAIN SHIELD
ENTERING THE CWA...AND RAMP THE POPS UP QUITE QUICKLY GENERALLY
AFTER 12Z WEDNESDAY WITH WELL DEFINED FORCING IN THE FORM OF
DEFORMATION AT PLAY HERE. DID SLOW DOWN THE ONSET OF THE CLOUD COVER
FROM THE PREVIOUS FORECAST BY ABOUT 6 HOURS OR SO. CHALLENGE TO THE
FORECAST COMES WHEN THE CLOSED LOW PASSES TO THE EAST AND INTO THE
DELMARVA WHILE A STRONG COLD FRONT ADVECTS ANOTHER SIGNIFICANTLY
COLDER AIRMASS FROM THE NORTHWEST. FLOW WILL BECOME
NORTHWESTERLY...AND THE FAMILIAR UPSLOPE PATTERN BEGINS AS
TEMPERATURES DROP THROUGH THE DAY THURSDAY. THIS WILL LEAD TO A
CHANGE IN THE PRECIPITATION FROM RAIN TO SNOW...WITH THE SNOW MAINLY
COMING BEYOND THE SCOPE OF THE SHORT TERM FORECAST PERIODS. THE TWO
MAIN QUESTIONS AS OF NOW ARE WILL THERE BE A LULL IN THE
PRECIPITATION JUST AFTER FROPA...AND WHEN WILL THE TRANSITION TO
SNOW OCCUR. WILL GO AGGRESSIVE WITH THE POPS WEDNESDAY NIGHT AND
THURSDAY...AND KEEP THE PRECIPITATION TYPE CHANGE LATE THURSDAY
WHERE QPF WILL BE QUITE A BIT LOWER THAN WITH THE CLOSED LOW.
HAVE NOT TRIED TO GET TOO CUTE WITH THE TEMPERATURES WEDNESDAY
THROUGH THURSDAY. TREND IS TO MODESTLY WARM ADVECT AT FIRST WITH THE
APPROACH OF THE UPPER LEVEL SYSTEM...KEEPING TEMPERATURES ON PACE
WITH THE ABOVE NORMAL TRENDS SEEN OF LATE. THURSDAY VALUES WILL NOT
RECOVER MUCH FROM THE WEDNESDAY NIGHT LOWS WITH THE ONSET OF THE
COLD ADVECTION...AND FEEL A BLEND OF THE MOSGUIDE AND MEX WAS BEST
OUT THIS FAR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MAIN SUPPORT ALOFT STILL MOVING THROUGH WEDNESDAY EVENING. AS LIKE
24 HOURS...THE 12Z GFS RUN IS THE STRONGEST ON THE SUPPORT AND AS A
RESULT THE HEAVIEST ON ITS RAINFALL. MAY BE A MAXIMUM RAINFALL
ALONG THE OHIO RIVER COUNTIES AND ANOTHER ON THE SE UPSLOPE IN THE
CENTRAL WV MOUNTAINS. WILL LEAVE IMPACT FOR RAIN IN THE CRWRWSRLX
BUT NO HAZARD FOR FLOODING IN THE HAZARDOUS WEATHER OUTLOOK...SINCE
STILL A PROGRESSIVE SYSTEM AND LITTLE OR NO SNOW PACK LEFT.
PRECIPITABLE WATER STILL PEAKING AROUND AN INCH.
STILL THINKING THE COLDER AIR WILL BE TAKING ITS TIME MOVING IN. SO
AS YESTERDAY...KEPT MINIMUM TEMPERATURES AOA MOS GUIDANCE WEDNESDAY
NIGHT. WILL HAVE TEMPERATURES FALLING THURSDAY AFTERNOON.
LIKE 24 HOURS AGO...THE TREND TO KEPT THE COLDER AIR HERE THROUGH
THE WEEKEND STILL EXISTS. SO KEPT TEMPERATURES COLDER THAN OUR HPC
MEDIUM RANGE SUPPORT. SEVERAL SMALL DISTURBANCE AROUND THE 500 MB
TROF...OR CLOSED LOW...IN SRN GREAT LAKES INTO SATURDAY. SO THE
SNOW SHOWER ACTIVITY MAY COME AND GO FRIDAY INTO SATURDAY. HAVE KEPT
POPS HIGHER THAN GUIDANCE MAINLY CRW ON N-NE. HOWEVER...THE MID AND
LOW LEVEL FLOW MAINLY WEST AND WESTNORTHWEST IN THIS PATTERN.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS UNDER BKN100 CEILINGS TO PREVAIL AT LEAST THROUGH
15Z MONDAY...WITH THE EXCEPTION OF MVFR CEILINGS AROUND 2000 FEET
POSSIBLE ALONG CENTRAL AND EASTERN MOUNTAINS.
A MID LEVEL DISTURBANCE APPROACHING FROM THE WEST WILL AID CLOUD
DECK TO THICKEN AND LOWER INTO MVFR 1800 FEET AT BKW AND THE
SOUTHERN THIRD OF THE AREA BY THIS AFTERNOON AND EVENING.
CONDITIONS WILL IMPROVE AFTER 22Z...FOR A GRADUAL RETURN OF VFR
CONDITIONS TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: ISOLATED IFR COULD RESULT OVER THE CENTRAL
AND SOUTHERN MOUNTAINS THIS AFTERNOON AND EVENING DUE TO LOW
CHANCE RAIN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY H H H H M M M M H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M L M H M H H H H H H L
EKN CONSISTENCY H H H H H M M M H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z TUESDAY...
IFR IN RAIN WED AND WED NT...AND IN RAIN AND SNOW SHOWERS THURSDAY
AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/ARJ
NEAR TERM...30
SHORT TERM...26
LONG TERM...KTB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
639 AM EST MON JAN 9 2012
.SYNOPSIS...
WEAK DISTURBANCE BRINGS LIGHT RAIN TO MAINLY THE SOUTHERN MOUNTAINS
MONDAY. HIGH PRESSURE TUESDAY. LOW PRESSURE WEDNESDAY. COLDER AIR
ARRIVES ON THURSDAY ON GUSTY WINDS AND LASTS INTO WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
MID TO HIGH CLOUDS WILL THICKEN AND LOWERED AS A H5 WAVE APPROACHES
FROM THE WEST. MODELS QPF FIELD SUGGEST VERY LIGHT PCPN ACROSS THE
EXTREME SOUTHERN THIRD OF OUR CWA...AND ALONG THE EASTERN MOUNTAINS
THIS MORNING.
MOST PCPN WILL STRUGGLE TO REACH THE GROUND PER A DRY LOW LEVEL
LAYER...AS SEEN IN RUC BUFKIT SOUNDINGS ACROSS THE LOWLANDS.
HOWEVER...SATURATION SPREADS TOWARD THE SFC ALLOWING SOME PCPN TO
REACH THE GROUND ALONG THE MOUNTAINS. THESE PCPN WILL BE BRIEF AND
NONE OR VERY LIGHT ACCUMULATIONS CAN BE EXPECTED.
SOME OF THE COLDEST VALLEYS WILL STILL BE AROUND 31 DEGREES THROUGH
AT LEAST 9 AM.
WENT WITH A BLEND BETWEEN THE BIAS CORRECTED SOLNS OF SREF AND
WRFARW FOR HIGHS TODAY...AND WITH THE WRFARW FOR LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE DRIFTS TO THE MID ATLANTIC COAST WHILE CLOSED LOW OVER
THE DEEP SOUTH MAKES A TURN NORTHEASTWARD INTO THE APPALACHIANS.
MODELS HAVE A FAIRLY GOOD HANDLE ON THE TIMING OF THE RAIN SHIELD
ENTERING THE CWA...AND RAMP THE POPS UP QUITE QUICKLY GENERALLY
AFTER 12Z WEDNESDAY WITH WELL DEFINED FORCING IN THE FORM OF
DEFORMATION AT PLAY HERE. DID SLOW DOWN THE ONSET OF THE CLOUD COVER
FROM THE PREVIOUS FORECAST BY ABOUT 6 HOURS OR SO. CHALLENGE TO THE
FORECAST COMES WHEN THE CLOSED LOW PASSES TO THE EAST AND INTO THE
DELMARVA WHILE A STRONG COLD FRONT ADVECTS ANOTHER SIGNIFICANTLY
COLDER AIRMASS FROM THE NORTHWEST. FLOW WILL BECOME
NORTHWESTERLY...AND THE FAMILIAR UPSLOPE PATTERN BEGINS AS
TEMPERATURES DROP THROUGH THE DAY THURSDAY. THIS WILL LEAD TO A
CHANGE IN THE PRECIPITATION FROM RAIN TO SNOW...WITH THE SNOW MAINLY
COMING BEYOND THE SCOPE OF THE SHORT TERM FORECAST PERIODS. THE TWO
MAIN QUESTIONS AS OF NOW ARE WILL THERE BE A LULL IN THE
PRECIPITATION JUST AFTER FROPA...AND WHEN WILL THE TRANSITION TO
SNOW OCCUR. WILL GO AGGRESSIVE WITH THE POPS WEDNESDAY NIGHT AND
THURSDAY...AND KEEP THE PRECIPITATION TYPE CHANGE LATE THURSDAY
WHERE QPF WILL BE QUITE A BIT LOWER THAN WITH THE CLOSED LOW.
HAVE NOT TRIED TO GET TOO CUTE WITH THE TEMPERATURES WEDNESDAY
THROUGH THURSDAY. TREND IS TO MODESTLY WARM ADVECT AT FIRST WITH THE
APPROACH OF THE UPPER LEVEL SYSTEM...KEEPING TEMPERATURES ON PACE
WITH THE ABOVE NORMAL TRENDS SEEN OF LATE. THURSDAY VALUES WILL NOT
RECOVER MUCH FROM THE WEDNESDAY NIGHT LOWS WITH THE ONSET OF THE
COLD ADVECTION...AND FEEL A BLEND OF THE MOSGUIDE AND MEX WAS BEST
OUT THIS FAR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MAIN SUPPORT ALOFT STILL MOVING THROUGH WEDNESDAY EVENING. AS LIKE
24 HOURS...THE 12Z GFS RUN IS THE STRONGEST ON THE SUPPORT AND AS A
RESULT THE HEAVIEST ON ITS RAINFALL. MAY BE A MAXIMUM RAINFALL
ALONG THE OHIO RIVER COUNTIES AND ANOTHER ON THE SE UPSLOPE IN THE
CENTRAL WV MOUNTAINS. WILL LEAVE IMPACT FOR RAIN IN THE CRWRWSRLX
BUT NO HAZARD FOR FLOODING IN THE HAZARDOUS WEATHER OUTLOOK...SINCE
STILL A PROGRESSIVE SYSTEM AND LITTLE OR NO SNOW PACK LEFT.
PRECIPITABLE WATER STILL PEAKING AROUND AN INCH.
STILL THINKING THE COLDER AIR WILL BE TAKING ITS TIME MOVING IN. SO
AS YESTERDAY...KEPT MINIMUM TEMPERATURES AOA MOS GUIDANCE WEDNESDAY
NIGHT. WILL HAVE TEMPERATURES FALLING THURSDAY AFTERNOON.
LIKE 24 HOURS AGO...THE TREND TO KEPT THE COLDER AIR HERE THROUGH
THE WEEKEND STILL EXISTS. SO KEPT TEMPERATURES COLDER THAN OUR HPC
MEDIUM RANGE SUPPORT. SEVERAL SMALL DISTURBANCE AROUND THE 500 MB
TROF...OR CLOSED LOW...IN SRN GREAT LAKES INTO SATURDAY. SO THE
SNOW SHOWER ACTIVITY MAY COME AND GO FRIDAY INTO SATURDAY. HAVE KEPT
POPS HIGHER THAN GUIDANCE MAINLY CRW ON N-NE. HOWEVER...THE MID AND
LOW LEVEL FLOW MAINLY WEST AND WESTNORTHWEST IN THIS PATTERN.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS UNDER BKN100 CEILINGS TO PREVAIL AT LEAST THROUGH
15Z MONDAY...WITH THE EXCEPTION OF MVFR CEILINGS AROUND 2000 FEET
POSSIBLE ALONG CENTRAL AND EASTERN MOUNTAINS.
A MID LEVEL DISTURBANCE APPROACHING FROM THE WEST WILL AID CLOUD
DECK TO THICKEN AND LOWER INTO MVFR 1800 FEET AT BKW AND THE
SOUTHERN THIRD OF THE AREA BY THIS AFTERNOON AND EVENING.
CONDITIONS WILL IMPROVE AFTER 22Z...FOR A GRADUAL RETURN OF VFR
CONDITIONS TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: ISOLATED IFR COULD RESULT OVER THE CENTRAL
AND SOUTHERN MOUNTAINS THIS AFTERNOON AND EVENING DUE TO LOW
CHANCE RAIN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M M H L M L H M H H H H
EKN CONSISTENCY H M H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z TUESDAY...
IFR IN RAIN WED AND WED NT...AND IN RAIN AND SNOW SHOWERS THURSDAY
AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
WVZ038-046-047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/ARJ
NEAR TERM...ARJ
SHORT TERM...26
LONG TERM...KTB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
436 AM EST MON JAN 9 2012
.SYNOPSIS...
WEAK DISTURBANCE BRINGS LIGHT RAIN TO MAINLY THE SOUTHERN MOUNTAINS
MONDAY. HIGH PRESSURE TUESDAY. LOW PRESSURE WEDNESDAY. COLDER AIR
ARRIVES ON THURSDAY ON GUSTY WINDS AND LASTS INTO WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
MID TO HIGH CLOUDS WILL THICKEN AND LOWERED AS A H5 WAVE APPROACHES
FROM THE WEST. MODELS QPF FIELD SUGGEST VERY LIGHT PCPN ACROSS THE
EXTREME SOUTHERN THIRD OF OUR CWA...AND ALONG THE EASTERN MOUNTAINS
THIS MORNING.
MOST PCPN WILL STRUGGLE TO REACH THE GROUND PER A DRY LOW LEVEL
LAYER...AS SEEN IN RUC BUFKIT SOUNDINGS ACROSS THE LOWLANDS.
HOWEVER...SATURATION SPREADS TOWARD THE SFC ALLOWING SOME PCPN TO
REACH THE GROUND ALONG THE MOUNTAINS. THESE PCPN WILL BE BRIEF AND
NONE OR VERY LIGHT ACCUMULATIONS CAN BE EXPECTED.
SOME OF THE COLDEST VALLEYS WILL STILL BE AROUND 31 DEGREES THROUGH
AT LEAST 9 AM.
WENT WITH A BLEND BETWEEN THE BIAS CORRECTED SOLNS OF SREF AND
WRFARW FOR HIGHS TODAY...AND WITH THE WRFARW FOR LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE DRIFTS TO THE MID ATLANTIC COAST WHILE CLOSED LOW OVER
THE DEEP SOUTH MAKES A TURN NORTHEASTWARD INTO THE APPALACHIANS.
MODELS HAVE A FAIRLY GOOD HANDLE ON THE TIMING OF THE RAIN SHIELD
ENTERING THE CWA...AND RAMP THE POPS UP QUITE QUICKLY GENERALLY
AFTER 12Z WEDNESDAY WITH WELL DEFINED FORCING IN THE FORM OF
DEFORMATION AT PLAY HERE. DID SLOW DOWN THE ONSET OF THE CLOUD COVER
FROM THE PREVIOUS FORECAST BY ABOUT 6 HOURS OR SO. CHALLENGE TO THE
FORECAST COMES WHEN THE CLOSED LOW PASSES TO THE EAST AND INTO THE
DELMARVA WHILE A STRONG COLD FRONT ADVECTS ANOTHER SIGNIFICANTLY
COLDER AIRMASS FROM THE NORTHWEST. FLOW WILL BECOME
NORTHWESTERLY...AND THE FAMILIAR UPSLOPE PATTERN BEGINS AS
TEMPERATURES DROP THROUGH THE DAY THURSDAY. THIS WILL LEAD TO A
CHANGE IN THE PRECIPITATION FROM RAIN TO SNOW...WITH THE SNOW MAINLY
COMING BEYOND THE SCOPE OF THE SHORT TERM FORECAST PERIODS. THE TWO
MAIN QUESTIONS AS OF NOW ARE WILL THERE BE A LULL IN THE
PRECIPITATION JUST AFTER FROPA...AND WHEN WILL THE TRANSITION TO
SNOW OCCUR. WILL GO AGGRESSIVE WITH THE POPS WEDNESDAY NIGHT AND
THURSDAY...AND KEEP THE PRECIPITATION TYPE CHANGE LATE THURSDAY
WHERE QPF WILL BE QUITE A BIT LOWER THAN WITH THE CLOSED LOW.
HAVE NOT TRIED TO GET TOO CUTE WITH THE TEMPERATURES WEDNESDAY
THROUGH THURSDAY. TREND IS TO MODESTLY WARM ADVECT AT FIRST WITH THE
APPROACH OF THE UPPER LEVEL SYSTEM...KEEPING TEMPERATURES ON PACE
WITH THE ABOVE NORMAL TRENDS SEEN OF LATE. THURSDAY VALUES WILL NOT
RECOVER MUCH FROM THE WEDNESDAY NIGHT LOWS WITH THE ONSET OF THE
COLD ADVECTION...AND FEEL A BLEND OF THE MOSGUIDE AND MEX WAS BEST
OUT THIS FAR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MAIN SUPPORT ALOFT STILL MOVING THROUGH WEDNESDAY EVENING. AS LIKE
24 HOURS...THE 12Z GFS RUN IS THE STRONGEST ON THE SUPPORT AND AS A
RESULT THE HEAVIEST ON ITS RAINFALL. MAY BE A MAXIMUM RAINFALL
ALONG THE OHIO RIVER COUNTIES AND ANOTHER ON THE SE UPSLOPE IN THE
CENTRAL WV MOUNTAINS. WILL LEAVE IMPACT FOR RAIN IN THE CRWRWSRLX
BUT NO HAZARD FOR FLOODING IN THE HAZARDOUS WEATHER OUTLOOK...SINCE
STILL A PROGRESSIVE SYSTEM AND LITTLE OR NO SNOW PACK LEFT.
PRECIPITABLE WATER STILL PEAKING AROUND AN INCH.
STILL THINKING THE COLDER AIR WILL BE TAKING ITS TIME MOVING IN. SO
AS YESTERDAY...KEPT MINIMUM TEMPERATURES AOA MOS GUIDANCE WEDNESDAY
NIGHT. WILL HAVE TEMPERATURES FALLING THURSDAY AFTERNOON.
LIKE 24 HOURS AGO...THE TREND TO KEPT THE COLDER AIR HERE THROUGH
THE WEEKEND STILL EXISTS. SO KEPT TEMPERATURES COLDER THAN OUR HPC
MEDIUM RANGE SUPPORT. SEVERAL SMALL DISTURBANCE AROUND THE 500 MB
TROF...OR CLOSED LOW...IN SRN GREAT LAKES INTO SATURDAY. SO THE
SNOW SHOWER ACTIVITY MAY COME AND GO FRIDAY INTO SATURDAY. HAVE KEPT
POPS HIGHER THAN GUIDANCE MAINLY CRW ON N-NE. HOWEVER...THE MID AND
LOW LEVEL FLOW MAINLY WEST AND WESTNORTHWEST IN THIS PATTERN.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS UNDER BKN100 CEILINGS TO PREVAIL AT LEAST THROUGH
15Z MONDAY...WITH THE EXCEPTION OF MVFR CEILINGS AROUND 2000 FEET
POSSIBLE ALONG CENTRAL AND EASTERN MOUNTAINS.
A MID LEVEL DISTURBANCE APPROACHING FROM THE WEST WILL AID CLOUD
DECK TO THICKEN AND LOWER INTO MVFR 1800 FEET AT BKW AND THE
SOUTHERN THIRD OF THE AREA BY THIS AFTERNOON AND EVENING.
CONDITIONS WILL IMPROVE AFTER 22Z...FOR A GRADUAL RETURN OF VFR
CONDITIONS TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: ISOLATED IFR COULD RESULT OVER THE CENTRAL
AND SOUTHERN MOUNTAINS THIS AFTERNOON AND EVENING DUE TO LOW
CHANCE RAIN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 01/09/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H M H M M M M M H M M
EKN CONSISTENCY H H H H M H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z TUESDAY...
IFR IN RAIN WED AND WED NT...AND IN RAIN AND SNOW SHOWERS THURSDAY
AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/ARJ
NEAR TERM...ARJ
SHORT TERM...26
LONG TERM...KTB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
324 AM EST MON JAN 9 2012
.SYNOPSIS...
WEAK DISTURBANCE BRINGS LIGHT RAIN TO MAINLY THE SOUTHERN MOUNTAINS
MONDAY. HIGH PRESSURE TUESDAY. LOW PRESSURE WEDNESDAY. COLDER AIR
ARRIVES ON THURSDAY ON GUSTY WINDS AND LASTS INTO WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
MID TO HIGH CLOUDS WILL THICKEN AND LOWERED AS A H5 WAVE APPROACHES
FROM THE WEST. MODELS QPF FIELD SUGGEST VERY LIGHT PCPN ACROSS THE
EXTREME SOUTHERN THIRD OF OUR CWA...AND ALONG THE EASTERN MOUNTAINS
THIS MORNING.
MOST PCPN WILL STRUGGLE TO REACH THE GROUND PER A DRY LOW LEVEL
LAYER...AS SEEN IN RUC BUFKIT SOUNDINGS ACROSS THE LOWLANDS.
HOWEVER...SATURATION SPREADS TOWARD THE SFC ALLOWING SOME PCPN TO
REACH THE GROUND ALONG THE MOUNTAINS. THESE PCPN WILL BE BRIEF AND
NONE OR VERY LIGHT ACCUMULATIONS CAN BE EXPECTED.
SOME OF THE COLDEST VALLEYS WILL STILL BE AROUND 31 DEGREES THROUGH
AT LEAST 9 AM.
WENT WITH A BLEND BETWEEN THE BIAS CORRECTED SOLNS OF SREF AND
WRFARW FOR HIGHS TODAY...AND WITH THE WRFARW FOR LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE DRIFTS TO THE MID ATLANTIC COAST WHILE CLOSED LOW OVER
THE DEEP SOUTH MAKES A TURN NORTHEASTWARD INTO THE APPALACHIANS.
MODELS HAVE A FAIRLY GOOD HANDLE ON THE TIMING OF THE RAIN SHIELD
ENTERING THE CWA...AND RAMP THE POPS UP QUITE QUICKLY GENERALLY
AFTER 12Z WEDNESDAY WITH WELL DEFINED FORCING IN THE FORM OF
DEFORMATION AT PLAY HERE. DID SLOW DOWN THE ONSET OF THE CLOUD COVER
FROM THE PREVIOUS FORECAST BY ABOUT 6 HOURS OR SO. CHALLENGE TO THE
FORECAST COMES WHEN THE CLOSED LOW PASSES TO THE EAST AND INTO THE
DELMARVA WHILE A STRONG COLD FRONT ADVECTS ANOTHER SIGNIFICANTLY
COLDER AIRMASS FROM THE NORTHWEST. FLOW WILL BECOME
NORTHWESTERLY...AND THE FAMILIAR UPSLOPE PATTERN BEGINS AS
TEMPERATURES DROP THROUGH THE DAY THURSDAY. THIS WILL LEAD TO A
CHANGE IN THE PRECIPITATION FROM RAIN TO SNOW...WITH THE SNOW MAINLY
COMING BEYOND THE SCOPE OF THE SHORT TERM FORECAST PERIODS. THE TWO
MAIN QUESTIONS AS OF NOW ARE WILL THERE BE A LULL IN THE
PRECIPITATION JUST AFTER FROPA...AND WHEN WILL THE TRANSITION TO
SNOW OCCUR. WILL GO AGGRESSIVE WITH THE POPS WEDNESDAY NIGHT AND
THURSDAY...AND KEEP THE PRECIPITATION TYPE CHANGE LATE THURSDAY
WHERE QPF WILL BE QUITE A BIT LOWER THAN WITH THE CLOSED LOW.
HAVE NOT TRIED TO GET TOO CUTE WITH THE TEMPERATURES WEDNESDAY
THROUGH THURSDAY. TREND IS TO MODESTLY WARM ADVECT AT FIRST WITH THE
APPROACH OF THE UPPER LEVEL SYSTEM...KEEPING TEMPERATURES ON PACE
WITH THE ABOVE NORMAL TRENDS SEEN OF LATE. THURSDAY VALUES WILL NOT
RECOVER MUCH FROM THE WEDNESDAY NIGHT LOWS WITH THE ONSET OF THE
COLD ADVECTION...AND FEEL A BLEND OF THE MOSGUIDE AND MEX WAS BEST
OUT THIS FAR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MAIN SUPPORT ALOFT STILL MOVING THROUGH WEDNESDAY EVENING. AS LIKE
24 HOURS...THE 12Z GFS RUN IS THE STRONGEST ON THE SUPPORT AND AS A
RESULT THE HEAVIEST ON ITS RAINFALL. MAY BE A MAXIMUM RAINFALL
ALONG THE OHIO RIVER COUNTIES AND ANOTHER ON THE SE UPSLOPE IN THE
CENTRAL WV MOUNTAINS. WILL LEAVE IMPACT FOR RAIN IN THE CRWRWSRLX
BUT NO HAZARD FOR FLOODING IN THE HAZARDOUS WEATHER OUTLOOK...SINCE
STILL A PROGRESSIVE SYSTEM AND LITTLE OR NO SNOW PACK LEFT.
PRECIPITABLE WATER STILL PEAKING AROUND AN INCH.
STILL THINKING THE COLDER AIR WILL BE TAKING ITS TIME MOVING IN. SO
AS YESTERDAY...KEPT MINIMUM TEMPERATURES AOA MOS GUIDANCE WEDNESDAY
NIGHT. WILL HAVE TEMPERATURES FALLING THURSDAY AFTERNOON.
LIKE 24 HOURS AGO...THE TREND TO KEPT THE COLDER AIR HERE THROUGH
THE WEEKEND STILL EXISTS. SO KEPT TEMPERATURES COLDER THAN OUR HPC
MEDIUM RANGE SUPPORT. SEVERAL SMALL DISTURBANCE AROUND THE 500 MB
TROF...OR CLOSED LOW...IN SRN GREAT LAKES INTO SATURDAY. SO THE
SNOW SHOWER ACTIVITY MAY COME AND GO FRIDAY INTO SATURDAY. HAVE KEPT
POPS HIGHER THAN GUIDANCE MAINLY CRW ON N-NE. HOWEVER...THE MID AND
LOW LEVEL FLOW MAINLY WEST AND WESTNORTHWEST IN THIS PATTERN.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS UNDER BKN100 CEILINGS TO PREVAIL AT LEAST THROUGH
12Z MONDAY...WITH THE EXCEPTION OF MVFR CEILINGS AROUND 2000 FEET
POSSIBLE ALONG CENTRAL AND EASTERN MOUNTAINS.
A MID LEVEL DISTURBANCE APPROACHING FROM THE WEST WILL AID CLOUD
DECK TO THICKEN AND LOWER INTO MVFR 1800 FEET AT BKW AND THE
SOUTHERN THIRD OF THE AREA MONDAY AFTERNOON AND EVENING.
CONDITIONS WILL IMPROVE AFTER 22Z...FOR A GRADUAL RETURN OF VFR
CONDITIONS MONDAY NIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: ISOLATED IFR COULD RESULT OVER THE CENTRAL
AND SOUTHERN MOUNTAINS THIS AFTERNOON AND EVENING DUE TO LOW
CHANCE RAIN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 01/09/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H M H M M M M M H M M
EKN CONSISTENCY H H H H M H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z TUESDAY...
IFR IN RAIN WED AND WED NT...AND IN RAIN AND SNOW SHOWERS THURSDAY
AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/ARJ
NEAR TERM...ARJ
SHORT TERM...26
LONG TERM...KTB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1135 PM CST SUN JAN 8 2012
.AVIATION...
WILL PREVAIL RAIN THROUGH 12Z AT METROPLEX TAF SITES. WITH INITIAL
WAVE OF CONVECTION WILL ALSO INCLUDE VCTS THROUGH 8Z...BUT
ACTIVITY SHOULD USE UP AVAILABLE INSTABILITY FOR ANY THUNDER
THEREAFTER. CIGS WILL BE MVFR INITIALLY BUT WILL LOWER TO IFR AS
LOW LEVEL SATURATION OCCURS WITH THE RAIN. VSBY OF 3-5SM WILL
PREVAIL IN RA/BR...BUT HEAVIER DOWNPOURS MAY RESULT IN BRIEF
PERIODS OF 1-2SM. EXPECT A LULL IN THE RAIN AROUND SUNRISE THROUGH
MID-LATE MORNING BEFORE NEXT WAVE ARRIVES. IN THE LULL...CIGS
SHOULD RISE TO MVFR...BUT WITH NEXT BATCH OF RAIN HAVE THEM
FALLING TO IFR AGAIN FOR MONDAY AFTERNOON AND EVENING. LIGHT RAIN
SHOULD PERSIST INTO MONDAY NIGHT.
FOR WACO NO REAL DIFFERENCE IN TIMING OF RAIN...BUT WITH GREATER
INSTABILITY WILL KEEP VCTS THROUGH 12Z. CIGS WILL BE MVFR
INITIALLY BUT SHOULD DROP TO IFR BY 8Z...AND STAY IFR THROUGH
TOMORROW EVENING. OTHERWISE EXPECT LESS RAIN COVERAGE/INTENSITY
TOMORROW EVENING WITH DRY SLOT MOVING IN FROM THE SOUTH AROUND
SUNSET.
NORTH WINDS SHOULD PREVAIL NEAR 10 KT.
TR.92
&&
.UPDATE...
OVERALL THE CURRENT FORECAST WAS ON TRACK BUT DID MAKE SOME MINOR
ADJUSTMENTS TO POPS AND TO WARM OVERNIGHT LOWS ACROSS THE REGION.
THE UPPER LEVEL LOW CAN BE SEEN ON IR AND WATER VAPOR SATELLITE
SPINNING SOUTH INTO NORTHERN MEXICO. A SURFACE LOW IS DEVELOPING
JUST AHEAD OF THE UPPER LEVEL LOW WITH A STATIONARY FRONT DRAPED
FROM NEAR DEL RIO TO NACOGDOCHES TO SHREVEPORT. THIS SURFACE FRONT
IS EXPECTED TO REMAIN NEARLY STATIONARY TONIGHT AND DEWPOINTS
ACROSS THE REGION ARE NOT EXPECTED TO CHANGE MUCH. ISENTROPIC
LIFT IS ALREADY OCCURRING WELL AHEAD OF THE UPPER LEVEL SYSTEM AND
SHOWERS AND THUNDERSTORMS ARE NOW DEVELOPING FROM EAST TEXAS BACK
TO FAR WEST TEXAS. SHOWERS AND ISOLATED THUNDERSTORMS ARE INCREASING
IN AREAL COVERAGE ACROSS NORTH TEXAS...MAINLY SOUTH OF INTERSTATE
20. EXPECT THE RAIN ACTIVITY TO CONTINUE TO INCREASE IN AREAL
COVERAGE ACROSS MUCH OF THE REGION TONIGHT. SHORT TERM MODELS SUCH
AS THE HRRR AND WRF...AND THE 00Z RUN OF THE NAM INDICATE MUCH OF
THE PRECIPITATION OVERNIGHT WILL FALL ALONG AND EAST OF
INTERSTATE 35...THUS INCREASED POPS ACROSS THE NORTHEASTERN
COUNTIES TO CATEGORICAL FOR THE OVERNIGHT HOURS. THE ONLY AREA
THAT LOOKS TO MISS ON MUCH OF THE PRECIPITATION TONIGHT IS THE FAR
NORTHWESTERN COUNTIES AND HAVE MAINTAINED 50 POPS FROM GRAHAM TO
GAINESVILLE. RADAR SIMULATIONS OF THE SHORT TERM MODELS THINK THAT
THE PRECIPITATION OVERNIGHT MAY CLEAR THE REGION TO THE EAST
AROUND DAYBREAK AND THEN THE NEXT ROUND OF RAIN WILL MOVE IN
DURING THE MONDAY MORNING HOURS...SO THERE COULD BE A BREAK IN THE
PRECIPITATION FOR A FEW HOURS MONDAY MORNING.
DUE TO EXTENSIVE AND DENSE CLOUD COVER AND NEARLY STEADY
DEWPOINTS TONIGHT...WARMED OVERNIGHT LOWS A FEW DEGREES IN
SEVERAL LOCATIONS ACROSS THE REGION. TEMPERATURES HAVE BEEN SLOW
TO FALL THIS EVENING AND MAY REMAIN NEARLY STEADY FOR MUCH OF THE
NIGHT BEFORE FALLING AROUND DAYBREAK AS THE FIRST ROUND OF RAIN
MOVES OUT AND SOME LOWER DEWPOINTS EDGE IN FROM THE NORTH.
ONE LAST QUICK NOTE ABOUT THE POTENTIAL FOR A RAIN/SNOW MIX MONDAY
NIGHT AND/OR TUESDAY...THE 00Z NAM CONTINUES TO SHOW ABOVE FREEZING
TEMPERATURES BOTH AT AND ABOVE THE SURFACE. THE 850 MB
TEMPERATURES HAVE WARMED CONSIDERABLY AND IT LOOKS LIKE MUCH OF
THE WRAP AROUND PRECIPITATION WILL OCCUR OUTSIDE OF THE REGION. AFTER
LOOKING AT ALL THE AVAILABLE MODEL DATA...HAVE PUSHED THE
RAIN/SNOW MIX LINE BACK TO JUST THE FAR WESTERN COUNTIES OF THE
CWA. WE ARE STILL NOT EXPECTING ANY IMPACTS DUE TO SNOW NOR ARE WE
EXPECTING ACCUMULATIONS.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 210 PM CST SUN JAN 8 2012/
OLD FRONT IS SLOWLY SINKING SOUTHEAST THIS AFTERNOON AND IS
CURRENTLY ALIGNED ALONG A TEXARKANA...PALESTINE...COLLEGE STATION
LINE WITH TEMPERATURES IN THE LOWER-MID 60S JUST SOUTH OF THE
FRONT TO AROUND 50 DEGREES ACROSS OUR FAR NORTHWEST COUNTIES.
SKIES WERE MOSTLY CLOUDY WITH A FEW SHOWERS NOW SHOWING UP ON
REGIONAL RADAR ACROSS SOUTHEAST TEXAS WITH OUR UPPER LOW NOW
DIVING SOUTHEAST ACROSS EASTERN ARIZONA.
.SHORT TERM/EARLY HALF OF THE WEEK/...
ISENTROPIC ASCENT IN THE 295-300K LAYER WILL CONTINUE TO INCREASE
FROM SOUTH TO NORTH ACROSS THE AREA TONIGHT IN WAA REGIME WELL OUT
AHEAD OF THE UPPER LOW WELL WEST OF NORTH TEXAS. GULF OF MEXICO
WILL BE OPEN FOR BUSINESS IN DEEP SOUTHERLY FETCH OVER THE TOP OF
THE SHALLOW FRONTAL INVERSION THROUGH MONDAY WITH RAIN BECOMING
WIDESPREAD ON MONDAY. LAPSE RATES WILL CONTINUE INCREASING ALOFT
BUT WILL NOT BE OVERLY STEEP WITH A FEW EMBEDDED AREAS OF THUNDER
EXPECTED ALL THE WAY INTO MONDAY NIGHT.
THE UPPER LOW LIFTS EAST ACROSS TEXAS MONDAY NIGHT AND TUESDAY...
TRACKING SOUTH OF I-20. AS THIS OCCURS...LIFT WILL BECOME MORE
DYNAMIC AND IN THE FORM OF DPVA/FRONTOGENETICAL PROCESSES WITH
LARGER SCALE VERTICAL MOTIONS. LOW AND MID LEVEL THICKNESSES WILL
FALL TO LEVELS INDICATING A BRIEF WINDOW FOR A POSSIBLE RAIN/SNOW
MIX LATE MONDAY NIGHT/TUESDAY. FOR NOW...WE WILL ONLY MENTION THIS
POTENTIAL IN THE COLDER AIRMASS FILTERING INTO OUR FAR WESTERN
COUNTIES WHERE HIGHS WILL STRUGGLE TO REACH OVER 40 DEGREES. FEEL
TEMPERATURES FURTHER EAST WILL BE TOO WARM TO SUPPORT SNOW MAKING
IT TO THE SURFACE. HOWEVER...IF FUTURE TEMPERATURES FORECAST COME
IN COLDER...THEN A RAIN/SNOW MIX MAY NEED TO BE CARRIED FURTHER
EAST TOWARD I-35/I-35E CORRIDOR. UPPER LOW WILL DEPART EAST OVER
LOWER MISSISSIPPI VALLEY BY WEDNESDAY MORNING WITH PRECIPITATION
ENDING FROM WEST TO EAST ACROSS NORTH TEXAS.
WEDNESDAY WILL BE QUIET AND SEASONABLE UNDER FLAT UPPER RIDGE
ALOFT.
.LONG TERM/END OF THE WEEK AND NEXT WEEKEND/...
A CHILLY END OF THE WEEK IS EXPECTED AS A STRONG COLD FRONT
CHARGES SOUTHWARD THROUGH THE PLAINS AND INTO TEXAS WEDNESDAY
NIGHT AND THURSDAY. THIS FRONT WILL BE SUPPORTED BY VERY STRONG
HEIGHT FALLS ACROSS THE THE UPPER MIDWEST AND GREAT LAKES WITH AN
UPPER RIDGE STEEPENING ACROSS THE U.S WEST COAST. WE HAVE UNDERCUT
MOS HIGHS THURSDAY/FRIDAY.
MEDIUM RANGE MODELS NOW AGREEING TO KEEP BULK OF EASTERN PACIFIC
ENERGY CUT OFF NEAR THE CALIFORNIA COASTLINE WITH CONFLUENT UPPER
FLOW ACROSS CENTRAL TEXAS. THIS PATTERN GENERALLY MEANS DRY AND
COLD WEATHER. THE CUT OFF LOW WILL EVENTUALLY GET PUSHED EAST
THROUGH THE DESERT SOUTHWEST NEXT WEEKEND BY A KICKER SYSTEM IN
THE PACIFIC NORTHWEST. TEMPERATURES WILL WARM UP AHEAD OF THIS
SYSTEM AS COLD SURFACE HIGH SHIFTS OVER THE GULF COAST STATES WITH
SWLY LOW LEVEL FLOW RETURNING. THOUGH LOW RAIN CHANCES APPEAR
POSSIBLE NEXT SUNDAY/MONDAY...HAVE LEFT THE FORECAST DRY UNTIL
MOISTURE AND TIMING OF BETTER LIFT CAN BE RESOLVED.
05/
&&
.SHORT TERM/EARLY HALF OF THE WEEK/...
ISENTROPIC ASCENT IN THE 295-300K LAYER WILL CONTINUE TO INCREASE
FROM SOUTH TO NORTH ACROSS THE AREA TONIGHT IN WAA REGIME WELL OUT
AHEAD OF THE UPPER LOW WELL WEST OF NORTH TEXAS. GULF OF MEXICO
WILL BE OPEN FOR BUSINESS IN DEEP SOUTHERLY FETCH OVER THE TOP OF
THE SHALLOW FRONTAL INVERSION THROUGH MONDAY WITH RAIN BECOMING
WIDESPREAD ON MONDAY. LAPSE RATES WILL CONTINUE INCREASING ALOFT
BUT WILL NOT BE OVERLY STEEP WITH A FEW EMBEDDED AREAS OF THUNDER
EXPECTED ALL THE WAY INTO MONDAY NIGHT.
THE UPPER LOW LIFTS EAST ACROSS TEXAS MONDAY NIGHT AND TUESDAY...
TRACKING SOUTH OF I-20. AS THIS OCCURS...LIFT WILL BECOME MORE
DYNAMIC AND IN THE FORM OF DPVA/FRONTOGENETICAL PROCESSES WITH
LARGER SCALE VERTICAL MOTIONS. LOW AND MID LEVEL THICKNESSES WILL
FALL TO LEVELS INDICATING A BRIEF WINDOW FOR A POSSIBLE RAIN/SNOW
MIX LATE MONDAY NIGHT/TUESDAY. FOR NOW...WE WILL ONLY MENTION THIS
POTENTIAL IN THE COLDER AIRMASS FILTERING INTO OUR FAR WESTERN
COUNTIES WHERE HIGHS WILL STRUGGLE TO REACH OVER 40 DEGREES. FEEL
TEMPERATURES FURTHER EAST WILL BE TOO WARM TO SUPPORT SNOW MAKING
IT TO THE SURFACE. HOWEVER...IF FUTURE TEMPERATURES FORECAST COME
IN COLDER...THEN A RAIN/SNOW MIX MAY NEED TO BE CARRIED FURTHER
EAST TOWARD I-35/I-35E CORRIDOR. UPPER LOW WILL DEPART EAST OVER
LOWER MISSISSIPPI VALLEY BY WEDNESDAY MORNING WITH PRECIPITATION
ENDING FROM WEST TO EAST ACROSS NORTH TEXAS.
WEDNESDAY WILL BE QUIET AND SEASONABLE UNDER FLAT UPPER RIDGE
ALOFT.
.LONG TERM/END OF THE WEEK AND NEXT WEEKEND/...
A CHILLY END OF THE WEEK IS EXPECTED AS A STRONG COLD FRONT
CHARGES SOUTHWARD THROUGH THE PLAINS AND INTO TEXAS WEDNESDAY
NIGHT AND THURSDAY. THIS FRONT WILL BE SUPPORTED BY VERY STRONG
HEIGHT FALLS ACROSS THE THE UPPER MIDWEST AND GREAT LAKES WITH AN
UPPER RIDGE STEEPENING ACROSS THE U.S WEST COAST. WE HAVE UNDERCUT
MOS HIGHS THURSDAY/FRIDAY.
MEDIUM RANGE MODELS NOW AGREEING TO KEEP BULK OF EASTERN PACIFIC
ENERGY CUT OFF NEAR THE CALIFORNIA COASTLINE WITH CONFLUENT UPPER
FLOW ACROSS CENTRAL TEXAS. THIS PATTERN GENERALLY MEANS DRY AND
COLD WEATHER. THE CUT OFF LOW WILL EVENTUALLY GET PUSHED EAST
THROUGH THE DESERT SOUTHWEST NEXT WEEKEND BY A KICKER SYSTEM IN
THE PACIFIC NORTHWEST. TEMPERATURES WILL WARM UP AHEAD OF THIS
SYSTEM AS COLD SURFACE HIGH SHIFTS OVER THE GULF COAST STATES WITH
SWLY LOW LEVEL FLOW RETURNING. THOUGH LOW RAIN CHANCES APPEAR
POSSIBLE NEXT SUNDAY/MONDAY...HAVE LEFT THE FORECAST DRY UNTIL
MOISTURE AND TIMING OF BETTER LIFT CAN BE RESOLVED.
05/
&&
.LONG TERM/END OF THE WEEK AND NEXT WEEKEND/...
A CHILLY END OF THE WEEK IS EXPECTED AS A STRONG COLD FRONT
CHARGES SOUTHWARD THROUGH THE PLAINS AND INTO TEXAS WEDNESDAY
NIGHT AND THURSDAY. THIS FRONT WILL BE SUPPORTED BY VERY STRONG
HEIGHT FALLS ACROSS THE THE UPPER MIDWEST AND GREAT LAKES WITH AN
UPPER RIDGE STEEPENING ACROSS THE U.S WEST COAST. WE HAVE UNDERCUT
MOS HIGHS THURSDAY/FRIDAY.
MEDIUM RANGE MODELS NOW AGREEING TO KEEP BULK OF EASTERN PACIFIC
ENERGY CUT OFF NEAR THE CALIFORNIA COASTLINE WITH CONFLUENT UPPER
FLOW ACROSS CENTRAL TEXAS. THIS PATTERN GENERALLY MEANS DRY AND
COLD WEATHER. THE CUT OFF LOW WILL EVENTUALLY GET PUSHED EAST
THROUGH THE DESERT SOUTHWEST NEXT WEEKEND BY A KICKER SYSTEM IN
THE PACIFIC NORTHWEST. TEMPERATURES WILL WARM UP AHEAD OF THIS
SYSTEM AS COLD SURFACE HIGH SHIFTS OVER THE GULF COAST STATES WITH
SWLY LOW LEVEL FLOW RETURNING. THOUGH LOW RAIN CHANCES APPEAR
POSSIBLE NEXT SUNDAY/MONDAY...HAVE LEFT THE FORECAST DRY UNTIL
MOISTURE AND TIMING OF BETTER LIFT CAN BE RESOLVED.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 44 48 40 45 36 / 90 100 100 60 10
WACO, TX 49 50 37 49 34 / 100 100 90 30 10
PARIS, TX 45 51 46 49 38 / 80 80 90 80 30
DENTON, TX 42 48 39 45 34 / 80 90 100 60 10
MCKINNEY, TX 43 49 42 45 35 / 80 90 100 70 20
DALLAS, TX 45 50 42 45 37 / 90 100 100 60 20
TERRELL, TX 45 52 43 48 36 / 90 100 100 60 20
CORSICANA, TX 50 57 41 48 36 / 100 100 100 50 20
TEMPLE, TX 50 50 39 52 34 / 100 100 80 20 5
MINERAL WELLS, TX 40 45 36 43 32 / 70 90 90 40 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SPOKANE WA
234 PM PST Mon Jan 9 2012
.SYNOPSIS...A storm system moves through the Inland Northwest
Monday night and Tuesday, with a chance of precipitation across
most of the region. The highest threat will be near the Cascades
and across the Blue Mountains, the Palouse and Idaho Panhandle
tonight, before decreasing from the west through Tuesday. High
pressure builds into the region starting late Tuesday, with dry
conditions and cooler temperatures through the end of the work
week. However watch for some patchy fog morning in the more
sheltered locations and near bodies of water. There is the
potential for more precipitation by next weekend.
&&
.DISCUSSION...
Tonight and Tomorrow...Front with weakening and elongating
subtropical moisture feed into it sags through Eastern Washington
and Northern Idaho tonight and exits to the southeast tomorrow.
The fact that the moisture feed is so narrow and appears to be
weakening as well as models showing a low spinning up along the
feed off the Northern California coast and further weakening the
feed continues to suggest the current course of action which is to
keep moderate to high pops but low precipitation and snow amounts
associated with the passage of this system. Kicker trof behind it
moves in with a drier and cooler northwest flow which allows for
an increase in wind and clearing conditions along with a cooling
trend apparent in forecast highs for tomorrow. Still some
uncertainty remains as latest HRRR model depicts a very elongated
and likely convectively enhanced band of precipitation forming
further north and west than what is depicted in the forecast but
still takes propagates it in the same general northwest to
southeast direction. /Pelatti
Tuesday night through Thursday: A shortwave trough exits early as
a ridge of high pressure builds in, bringing generally dry
conditions, occasional cloudy periods and cooler than normal
temperatures. On Tuesday evening the shortwave system moves toward
the High Plains. Save for the boundary layer, the atmosphere dries
out in the northwesterly flow behind it. A chance of snow showers
will linger around the central Panhandle in the evening but
otherwise dry weather is expected. Breezy conditions are expected
in the evening, then incoming high pressure will allow gradients
to slacken and winds to subside. How much the evening winds are
able to dry out the boundary layer will impact the potential for
stratus and fog overnight and Wednesday morning. The best chances
will be in the sheltered mountain valleys (from the Cascades
through the Selkirks and Central Panhandle Mountains) as well as
in the L-C valley. Fog is also a risk around the deeper basin, the
Long Lake and the Spokane River, as well as West Plains area;
however the moisture appears shallower and fog may be less
persistent here.
Going into Wednesday night and Thursday models track a couple
upper level disturbances across the region. With little deep
moisture and no strong connection to the surface, these
disturbances are expected to pass without any precipitation.
However look for increased middle to high level clouds. Fog and
stratus will once again be a threat Wednesday night and Thursday
morning, however coverage is expected to be less with the
aforementioned middle and high clouds. How thick or persistent or
widespread these clouds are will impact the potential for fog.
They will also impact temperatures.
Temperatures are expected to drop below normal through this
period, as cooler air invades from the north-northwest behind
Tuesday`s wave. With light winds and drier air coming in,
nighttime lows are expected to drop in the teens to low 20s, with
some single digits possible around the Cascades and northern
mountains. Afternoon highs are expected to be in the 20s and low
30s, with some teens in the mountains. Expect some moderation on
Thursday as compared to Wednesday. Overall values are projected to
be around 5 degrees or so below average. Precise numbers will be
impacted by the cloud and/or fog coverage; if more persistent cloud
cover develops, overnights lows may be too cool. /J. Cote`
Thursday night through Monday...Models are indicating a potential
pattern change towards the end of the extended period. The upper
ridge over the area is expected to flatten with a high amplitude
ridge developing between 150-160W out in the Eastern Pacific. This
would allow a cold trough in the Gulf of Alaska to drop southeast
towards Washington and North Idaho Sunday and Monday. The 12z and
00z runs of the ECMWF, Canadian, and UKMET extension favor this
with about half of the GFS Ensemble members also in support. Thus
the milder 12z GFS solution with trying to hold onto more ridging is
not as likely to pan out. But given the tendency for the ridge
this fall and winter, the 12z GFS can not be ruled out.
The Inland Northwest will be under generally dry zonal flow Friday
and Saturday with near normal temperatures. And then as the trough
drops over the area Sunday and Monday with 850mb temps cooling in
the -5 to -10C range...temperatures will lower to below normal
readings by Monday. The flow aloft remains westerly Sunday and
Monday so best potential for snow showers will be in the
mountains. JW
&&
.AVIATION...
18Z TAFS: Nuisance low clouds and fog linger near lowlands in the
lee of the East Slopes of the Northern Cascades and into portions of
the Columbia Basin this morning affecting locations such as KEAT and
KMWH this morning...otherwise clouds will continue to invade the sky
from a general west to east direction and will thicken and lower.
Precipitation will make a similar west to east motion through the
area as well generally starting near the Northern Cascades near 22Z,
00Z for KGEG and vicinity and 5Z for KPUW and KLWS. Mixture of
frozen and liquid precipitation north of I-90 with primarily liquid
south of it. All of this weather activity will allow for nuisance
IFR conditions due to varying height of stratus ceilings,
precipitation intensity and fog thickness occur in aviation
forecasts at times. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 29 33 18 28 19 28 / 60 10 0 0 0 0
Coeur d`Alene 29 35 17 31 18 29 / 70 10 0 0 0 0
Pullman 31 37 21 31 23 33 / 80 30 0 0 0 0
Lewiston 33 40 23 34 23 35 / 80 40 0 0 0 0
Colville 27 33 13 28 17 33 / 30 10 0 0 0 0
Sandpoint 30 34 16 28 17 30 / 70 10 0 0 0 0
Kellogg 29 35 20 28 18 29 / 90 30 0 0 0 0
Moses Lake 29 36 17 31 19 30 / 20 0 0 0 0 0
Wenatchee 28 35 22 29 20 32 / 10 0 0 0 0 0
Omak 27 31 14 29 16 31 / 10 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
546 AM CST MON JAN 9 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
215 AM CST MON JAN 9 2012
MAIN FORECAST CONCERNS ARE ON TEMPERATURES THROUGH TUESDAY NIGHT...
THEN THE COOL DOWN AND PRECIPITATION CHANCES FOR MIDWEEK.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING FROM CALIFORNIA INTO SOUTHERN ALBERTA...A CUT-OFF
UPPER LOW OVER NORTHERN MEXICO...BROAD TROUGHING OVER SOUTHEAST
CANADA INTO THE GREAT LAKES...AND A SHORTWAVE OVER NORTHERN
MINNESOTA. THIS SHORTWAVE IS PRODUCING AN AREA OF MID AND HIGH
CLOUDS ACROSS MUCH OF MINNESOTA INTO NORTHERN WISCONSIN...AS WELL
AS A TIGHTER SURFACE PRESSURE GRADIENT. 925MB RUC AND VAD WIND
PROFILE DATA REFLECT THE INCREASING PRESSURE GRADIENT...WITH
SOUTHWEST WINDS OF 40-45KT ACROSS MUCH OF MINNESOTA. THESE WINDS
ARE ADVECTING WARMER AIR EASTWARD...NOTED BY A 1-3C INCREASE IN
925MB TEMPS AT MPX...ABR AND BIS BETWEEN 12Z YESTERDAY AND 00Z
TODAY PER RAOB DATA. 00Z DATA NOW SHOW READINGS BETWEEN
1-3C...HIGHEST AT BIS. SURFACE TEMPERATURES HAVE RESPONDED TO THE
INCREASING WINDS...CLOUDS AND WARM ADVECTION BY MOSTLY STAYING IN
THE 20S TO LOW 30S. AIRMASS REMAINS DRY AS WELL OVER THE UPPER
MIDWEST WITH 10C OR HIGHER DEWPOINT DEPRESSIONS BELOW 600MB ON THE
00Z BIS...ABR AND MPX SOUNDINGS.
TODAY AND TONIGHT...SHORTWAVE OVER NORTHERN MINNESOTA IS FORECAST TO
DIVE SOUTHEAST INTO LOWER MICHIGAN BY 00Z. IN ITS WAKE...500MB
HEIGHTS ARE EXPECTED TO GRADUALLY RISE OVER THE FORECAST AREA. THESE
HEIGHT RISES SHOULD CONTINUE THROUGH TONIGHT...AND THESE ARE IN
RESPONSE TO A POTENT TROUGH DEVELOPING OVER SOUTHWEST CANADA.
SUBSIDENCE ASSOCIATED WITH THE HEIGHT RISES...IN COMBINATION WITH
ALL THE DRY AIR PRESENT OVER THE AREA...WILL RESULT IN CONTINUED DRY
CONDITIONS. THE HEIGHT RISES ALSO MEAN CONTINUED WARM ADVECTION...
REFLECTED BY 925MB TEMPS CLIMBING TO 0-2C BY 18Z TODAY. THESE ARE
AROUND 2C HIGHER THAN YESTERDAY AT 18Z. SUNSHINE MAY BE SOMEWHAT
LIMITED INITIALLY THIS MORNING BY THE MID AND HIGH CLOUDS...BUT
THESE SHOULD CLEAR IN THE AFTERNOON AS THE SHORTWAVE MOVES AWAY FROM
THE AREA. IT DOES TO LOOK TO STAY BREEZY THIS MORNING WITH THE
PRESSURE GRADIENT FAIRLY TIGHT...AS WELL AS THAT 925MB WIND CORE
COMING ACROSS. THE WINDS SHOULD DIMINISH IN THE AFTERNOON...ALSO DUE
TO THE SHORTWAVE MOVING AWAY FROM THE AREA AND A WEAK SURFACE RIDGE
DEVELOPING OVER MINNESOTA. ALL IN ALL WE SHOULD END UP WITH PLENTY
OF MIXING...FROM THE WINDS THIS MORNING AND SUN IN THE AFTERNOON...
ALLOWING TEMPERATURES TO CLIMB WELL INTO THE 40S FOR MOST LOCATIONS.
THE SURFACE RIDGE MOVES OVER THE AREA TONIGHT...AND WITH ONLY SOME
SCATTERED MID CLOUDS POSSIBLE...ANTICIPATING TEMPERATURES TO FALL
OFF INTO THE 20S TO LOW 30S. THIS IS DESPITE SOME 925MB WARMING
WHICH REACHES 2-5C BY 12Z.
TUESDAY AND TUESDAY NIGHT...MODELS ARE IN GOOD AGREEMENT DIGGING THE
POTENT UPPER TROUGH SOUTHEAST INTO EASTERN MONTANA AND NORTH DAKOTA
BY 12Z WEDNESDAY. AS THIS UPPER TROUGH DIGS SOUTHEAST...A COLD FRONT
WELL OUT AHEAD OF IT SHOULD MOVE INTO AND PERHAPS THROUGH THE
FORECAST AREA BETWEEN 06-12Z WEDNESDAY. NOT ANTICIPATING ANY
PRECIPITATION ON OR AHEAD OF THE FRONT DUE TO AGAIN THE DRY AIRMASS.
EVEN BEHIND THE FRONT...ANY PRECIPITATION LOOKS TO STAY A LITTLE
FARTHER WEST...CLOSER TO THE DPVA FORCING WITH THE UPPER TROUGH AND
MID-LEVEL FRONTOGENESIS. SO PERHAPS BY 12Z...SOME PRECIPITATION
COULD BE APPROACHING I-35 AND FAR NORTHWEST WI...ASSUMING THE
ATMOSPHERE CAN SATURATE. FOR OUR AREA...MAIN CONCERN IS THE WARMING
OCCURRING AHEAD OF THE FRONT. 925MB TEMPS CLIMB A LITTLE FURTHER ON
TUESDAY TO 3-6C BY 18Z. OTHER THAN MAYBE FOR A FEW MID OR HIGH
CLOUDS AT BEST...SHOULD SEE MOSTLY SUNNY SKIES. WINDS PICK UP TOO
WITH THE DIGGING OF THE UPPER TROUGH...ALBEIT ONLY 5 TO 15 KT.
STILL...IT IS OUT OF A FAVORABLE SOUTHWEST DIRECTION. SO ALL SIGNS
POINT TO GOOD MIXING ON TUESDAY. HIGHS SHOULD EASILY CLIMB WELL INTO
THE 40S WITH LOW 50S LIKELY TOO. COOLING SHOULD OCCUR GRADUALLY
TUESDAY EVENING...THEN PERHAPS PICK UP SOME AFTER MIDNIGHT WITH
THE COLD FRONTAL PASSAGE. ON THE OTHER HAND...THE WINDS BEHIND THE
FRONT ADVECTING IN COLDER AIR MAY ALSO HELP TO KEEP THE ATMOSPHERE
MIXED. THEREFORE...HAVE FOLLOWED A BLEND OF GUIDANCE FOR LOWS.
WEDNESDAY AND WEDNESDAY NIGHT...SOME DIFFERENCES BEGIN TO SHOW UP
WITH THE HANDLING OF THE POTENT UPPER TROUGH. THE 09.00Z GFS/NAM AND
08.12Z/09.00Z ECMWF SHOW THE UPPER TROUGH MOVING OVER MUCH OF
MINNESOTA BY 00Z THURSDAY AND OVER MUCH OF THE FORECAST AREA BY 12Z
THURSDAY. WITHIN THIS GROUP...THE ECMWF SHOWS AN UPPER LOW IN
SOUTHERN MINNESOTA WHEREAS THE GFS/NAM PLACE IT IN WESTERN UPPER
MICHIGAN. THE 09.00Z UKMET/CANADIAN ON THE OTHER HAND HAVE A SLOWER
UPPER TROUGH...KEEPING IT STILL IN THE DAKOTAS AT 00Z THURSDAY...
THEN MOVING INTO MINNESOTA POSITIVELY TILTED BY 12Z THURSDAY AND NO
UPPER LOW CENTER. HPC PMDHMD PRODUCT DETAILS A LOT OF ISSUES WITH
THE 08.12Z/09.00Z ECMWF...09.00Z GFS AND NAM REGARDING THIS
TROUGH... SAYING THEY ARE ALL TOO AMPLIFIED AND FAST. A PREFERENCE
IS FOR A SLOWER SOLUTION...WHICH WOULD MATCH THE TREND SEEN WITH THE
08.00Z MODELS. THE SPEED OF THE TROUGH HAS BIG IMPACTS ON
WEDNESDAYS HIGHS...SINCE THE COLD AIR WOULD FLOW IN FASTER IN THE
08.12Z AND ESPECIALLY 09.00Z GFS/NAM SCENARIOS. EITHER WAY...THE
COLD AIR WILL EVENTUALLY FLOW INTO THE FORECAST AREA...WITH ALL
MODELS SHOWING 850MB TEMPS TANKING TO -16 TO -20C BY 12Z THURSDAY.
UNTIL MODELS RESOLVE THE TIMING...HAVE LEFT THE TEMPERATURE
FORECASTS MOSTLY ALONE...KEEPING TOO THAT FALLING TEMPERATURE TREND
WEDNESDAY AFTERNOON SINCE EVEN THE SLOWER SOLUTIONS WOULD SUGGEST
THAT. PRECIPITATION IS LOOKING HARDER AND HARDER TO COME BY WITH
THIS UPPER TROUGH. CERTAINLY THE DYNAMICS LOOK IMPRESSIVE...EVEN
WITH THE POSITIVELY TILTED SOLUTIONS WHICH HAVE ANYWHERE FROM 60-100
METER HEIGHT FALLS AT 500MB FOR WEDNESDAY AND AGAIN WEDNESDAY NIGHT.
HOWEVER...THE MOISTURE IS VERY LIMITED...DUE TO THE DRY AIRMASS
AHEAD OF THE TROUGH AND GULF OF MEXICO MOISTURE CUT-OFF FROM AN
UPPER LOW RIDING THROUGH THERE. MODELS AT BEST SHOW A COUPLE OF
HUNDREDTHS OF QPF COMING THROUGH THE FORECAST AREA...AND THAT IS
MOSTLY ON WEDNESDAY. THEREFORE...HAVE KEPT PRECIPITATION CHANCES IN
THE 20-50 RANGE FOR NOW.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
215 AM CST MON JAN 9 2012
09.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES AGREE IN GENERAL WITH
THE MEAN UPPER LEVEL PATTERN THROUGHOUT THE EXTENDED...WHICH
FEATURES MOSTLY TROUGHING OVER THE CENTRAL AND EASTERN U.S.. MOST OF
THIS TROUGHING STARTS FROM THAT POTENT TROUGH DROPPING DOWN INTO THE
FORECAST AREA WEDNESDAY NIGHT. THE TROUGHING THEN GETS REINFORCED BY
A SHORTWAVE DROPPING SOUTH THROUGH THE UPPER MIDWEST FRIDAY
NIGHT...PERHAPS CROSSING THE FORECAST AREA ON SATURDAY ACCORDING TO
SOME MODEL SOLUTIONS. THERE ARE INDICATIONS THAT RIDGING WILL BUILD
TOWARDS THE AREA ON SUNDAY DUE TO TROUGHING DROPPING DOWN INTO
BRITISH COLUMBIA AND WASHINGTON STATE.
THURSDAY THROUGH FRIDAY ARE LIKELY TO BE QUITE CHILLY...COMPARED TO
WHAT WE HAVE SEEN RECENTLY...WITH 850MB TEMPS DROPPING TO AROUND
-20C BY 00Z FRIDAY. MOSTLY CLOUDY SKIES WILL ALSO LIMIT DIURNAL
HEATING...THOUGH AT THE SAME TIME HELP TEMPERATURES FROM TANKING
THURSDAY NIGHT. SOME SLOW MODERATION IS ANTICIPATED FOR FRIDAY AS
THE CORE OF THE COLD AIR LIFTS OUT TO THE NORTHEAST...BUT STILL
READINGS SHOULD STAY BELOW NORMAL. THE SLOW MODERATION CONTINUES
THROUGH THE WEEKEND...ESPECIALLY ON SUNDAY WHEN THE RIDGING STARTS
BUILDING IN. THROUGHOUT THE LONG TERM PERIOD...FOLLOWED A CONSENSUS
OF GUIDANCE FOR TEMPERATURES.
PRECIPITATION CHANCES LOOKS PRETTY SLIM DUE TO AGAIN A LACK OF
MOISTURE. 09.00Z ECMWF HINTING THAT THERE COULD BE A LITTLE LIGHT
SNOW THURSDAY NIGHT WRAPPING AROUND...BUT IT IS THE ONLY MODEL
SHOWING IT. PLUS...WITH THE CONCERN MENTIONED IN THE WEDNESDAY
DISCUSSION ABOVE ABOUT THE ECMWF...NOT READY TO JUMP ON PUTTING
PRECIPITATION CHANCES IN FOR THURSDAY NIGHT. NEXT POTENTIAL TIME
PERIOD FOR PRECIPITATION CHANCES WOULD COME SATURDAY WITH THE
SHORTWAVE COMING THROUGH. HOWEVER...MODELS HAVE BEEN FAR FROM
CONSISTENT ON THE TRACK OF THIS SHORTWAVE...AND SOME HAVE IT GOING
NORTH AND SOUTH OF THE AREA FOR THIS 09.00Z CYCLE. THEREFORE...HAVE
MAINTAINED SATURDAY DRY TOO. THIS RESULTS IN THE ENTIRE LONG TERM
FORECAST DRY FOR NOW.
&&
.AVIATION...TODAY AND TONIGHT
546 AM CST MON JAN 9 2012
BROKEN MID LEVEL CLOUDS WILL SHIFT EAST OF THE TAF SITES THIS
MORNING. PLAN ON CLOUD BASES AROUND 12 KFT EARLY THIS
MORNING...THEN SKIES WILL BECOME MOSTLY CLEAR BY MID MORNING. PLAN
ON LOW LEVEL WIND SHEAR AT KLSE THROUGH AROUND 14Z AS THE
MISSISSIPPI RIVER VALLEY REMAINS DECOUPLED...WITH SURFACE WINDS
SOUTH AT AROUND 6 KTS. VAD WIND PROFILES SHOW WINDS INCREASING TO
AROUND 40 KTS AT 1KFT AT 1143 Z. FORECAST SOUNDINGS ALSO INDICATE
THIS LLWS...SO HAVE INCLUDED IT IN THE KLSE TAF. OTHERWISE LOOK
FOR SOUTHWEST WINDS AT 15 TO 18 KTS WITH GUSTS TO AROUND 27 KTS
POSSIBLE. THE WINDS WILL GRADUALLY DIMINISH THIS AFTERNOON AS THE
PRESSURE GRADIENT SLACKENS...DECREASING TO AROUND 8 KTS BY 22Z.
WINDS ARE EXPECTED TO BECOME LIGHT THIS EVENING WITH GUIDANCE
SHOWING THE POTENTIAL FOR SOME BR OR FOG. GIVEN THE DRYNESS OF THE
LOWER LEVELS AND SOME HIGH CLOUDS MOVING INTO THE
REGION...THINKING OVERALL FOG THREAT LOOKS MINIMAL. HAVE DECIDED
TO INCLUDE 5SM BR AT THE TAF SITES STARTING AT 03Z. WILL HAVE TO
KEEP A CLOSE WATCH ON CLOUDS AND LOW LEVEL RELATIVE HUMIDITY THIS
EVENING. IF THE LOW LEVEL MOISTURE INCREASES AND CLOUDS DO NOT
MATERIALIZE...IFR CONDITIONS ARE A POSSIBILITY TONIGHT IN FOG.
CONFIDENCE LOW ON IFR CONDITIONS OCCURRING TONIGHT...BUT WILL
CONTINUE TO CLOSELY MONITOR TRENDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
215 AM CST MON JAN 9 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
215 AM CST MON JAN 9 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
215 AM CST MON JAN 9 2012
MAIN FORECAST CONCERNS ARE ON TEMPERATURES THROUGH TUESDAY NIGHT...
THEN THE COOL DOWN AND PRECIPITATION CHANCES FOR MIDWEEK.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING FROM CALIFORNIA INTO SOUTHERN ALBERTA...A CUT-OFF
UPPER LOW OVER NORTHERN MEXICO...BROAD TROUGHING OVER SOUTHEAST
CANADA INTO THE GREAT LAKES...AND A SHORTWAVE OVER NORTHERN
MINNESOTA. THIS SHORTWAVE IS PRODUCING AN AREA OF MID AND HIGH
CLOUDS ACROSS MUCH OF MINNESOTA INTO NORTHERN WISCONSIN...AS WELL
AS A TIGHTER SURFACE PRESSURE GRADIENT. 925MB RUC AND VAD WIND
PROFILE DATA REFLECT THE INCREASING PRESSURE GRADIENT...WITH
SOUTHWEST WINDS OF 40-45KT ACROSS MUCH OF MINNESOTA. THESE WINDS
ARE ADVECTING WARMER AIR EASTWARD...NOTED BY A 1-3C INCREASE IN
925MB TEMPS AT MPX...ABR AND BIS BETWEEN 12Z YESTERDAY AND 00Z
TODAY PER RAOB DATA. 00Z DATA NOW SHOW READINGS BETWEEN
1-3C...HIGHEST AT BIS. SURFACE TEMPERATURES HAVE RESPONDED TO THE
INCREASING WINDS...CLOUDS AND WARM ADVECTION BY MOSTLY STAYING IN
THE 20S TO LOW 30S. AIRMASS REMAINS DRY AS WELL OVER THE UPPER
MIDWEST WITH 10C OR HIGHER DEWPOINT DEPRESSIONS BELOW 600MB ON THE
00Z BIS...ABR AND MPX SOUNDINGS.
TODAY AND TONIGHT...SHORTWAVE OVER NORTHERN MINNESOTA IS FORECAST TO
DIVE SOUTHEAST INTO LOWER MICHIGAN BY 00Z. IN ITS WAKE...500MB
HEIGHTS ARE EXPECTED TO GRADUALLY RISE OVER THE FORECAST AREA. THESE
HEIGHT RISES SHOULD CONTINUE THROUGH TONIGHT...AND THESE ARE IN
RESPONSE TO A POTENT TROUGH DEVELOPING OVER SOUTHWEST CANADA.
SUBSIDENCE ASSOCIATED WITH THE HEIGHT RISES...IN COMBINATION WITH
ALL THE DRY AIR PRESENT OVER THE AREA...WILL RESULT IN CONTINUED DRY
CONDITIONS. THE HEIGHT RISES ALSO MEAN CONTINUED WARM ADVECTION...
REFLECTED BY 925MB TEMPS CLIMBING TO 0-2C BY 18Z TODAY. THESE ARE
AROUND 2C HIGHER THAN YESTERDAY AT 18Z. SUNSHINE MAY BE SOMEWHAT
LIMITED INITIALLY THIS MORNING BY THE MID AND HIGH CLOUDS...BUT
THESE SHOULD CLEAR IN THE AFTERNOON AS THE SHORTWAVE MOVES AWAY FROM
THE AREA. IT DOES TO LOOK TO STAY BREEZY THIS MORNING WITH THE
PRESSURE GRADIENT FAIRLY TIGHT...AS WELL AS THAT 925MB WIND CORE
COMING ACROSS. THE WINDS SHOULD DIMINISH IN THE AFTERNOON...ALSO DUE
TO THE SHORTWAVE MOVING AWAY FROM THE AREA AND A WEAK SURFACE RIDGE
DEVELOPING OVER MINNESOTA. ALL IN ALL WE SHOULD END UP WITH PLENTY
OF MIXING...FROM THE WINDS THIS MORNING AND SUN IN THE AFTERNOON...
ALLOWING TEMPERATURES TO CLIMB WELL INTO THE 40S FOR MOST LOCATIONS.
THE SURFACE RIDGE MOVES OVER THE AREA TONIGHT...AND WITH ONLY SOME
SCATTERED MID CLOUDS POSSIBLE...ANTICIPATING TEMPERATURES TO FALL
OFF INTO THE 20S TO LOW 30S. THIS IS DESPITE SOME 925MB WARMING
WHICH REACHES 2-5C BY 12Z.
TUESDAY AND TUESDAY NIGHT...MODELS ARE IN GOOD AGREEMENT DIGGING THE
POTENT UPPER TROUGH SOUTHEAST INTO EASTERN MONTANA AND NORTH DAKOTA
BY 12Z WEDNESDAY. AS THIS UPPER TROUGH DIGS SOUTHEAST...A COLD FRONT
WELL OUT AHEAD OF IT SHOULD MOVE INTO AND PERHAPS THROUGH THE
FORECAST AREA BETWEEN 06-12Z WEDNESDAY. NOT ANTICIPATING ANY
PRECIPITATION ON OR AHEAD OF THE FRONT DUE TO AGAIN THE DRY AIRMASS.
EVEN BEHIND THE FRONT...ANY PRECIPITATION LOOKS TO STAY A LITTLE
FARTHER WEST...CLOSER TO THE DPVA FORCING WITH THE UPPER TROUGH AND
MID-LEVEL FRONTOGENESIS. SO PERHAPS BY 12Z...SOME PRECIPITATION
COULD BE APPROACHING I-35 AND FAR NORTHWEST WI...ASSUMING THE
ATMOSPHERE CAN SATURATE. FOR OUR AREA...MAIN CONCERN IS THE WARMING
OCCURRING AHEAD OF THE FRONT. 925MB TEMPS CLIMB A LITTLE FURTHER ON
TUESDAY TO 3-6C BY 18Z. OTHER THAN MAYBE FOR A FEW MID OR HIGH
CLOUDS AT BEST...SHOULD SEE MOSTLY SUNNY SKIES. WINDS PICK UP TOO
WITH THE DIGGING OF THE UPPER TROUGH...ALBEIT ONLY 5 TO 15 KT.
STILL...IT IS OUT OF A FAVORABLE SOUTHWEST DIRECTION. SO ALL SIGNS
POINT TO GOOD MIXING ON TUESDAY. HIGHS SHOULD EASILY CLIMB WELL INTO
THE 40S WITH LOW 50S LIKELY TOO. COOLING SHOULD OCCUR GRADUALLY
TUESDAY EVENING...THEN PERHAPS PICK UP SOME AFTER MIDNIGHT WITH
THE COLD FRONTAL PASSAGE. ON THE OTHER HAND...THE WINDS BEHIND THE
FRONT ADVECTING IN COLDER AIR MAY ALSO HELP TO KEEP THE ATMOSPHERE
MIXED. THEREFORE...HAVE FOLLOWED A BLEND OF GUIDANCE FOR LOWS.
WEDNESDAY AND WEDNESDAY NIGHT...SOME DIFFERENCES BEGIN TO SHOW UP
WITH THE HANDLING OF THE POTENT UPPER TROUGH. THE 09.00Z GFS/NAM AND
08.12Z/09.00Z ECMWF SHOW THE UPPER TROUGH MOVING OVER MUCH OF
MINNESOTA BY 00Z THURSDAY AND OVER MUCH OF THE FORECAST AREA BY 12Z
THURSDAY. WITHIN THIS GROUP...THE ECMWF SHOWS AN UPPER LOW IN
SOUTHERN MINNESOTA WHEREAS THE GFS/NAM PLACE IT IN WESTERN UPPER
MICHIGAN. THE 09.00Z UKMET/CANADIAN ON THE OTHER HAND HAVE A SLOWER
UPPER TROUGH...KEEPING IT STILL IN THE DAKOTAS AT 00Z THURSDAY...
THEN MOVING INTO MINNESOTA POSITIVELY TILTED BY 12Z THURSDAY AND NO
UPPER LOW CENTER. HPC PMDHMD PRODUCT DETAILS A LOT OF ISSUES WITH
THE 08.12Z/09.00Z ECMWF...09.00Z GFS AND NAM REGARDING THIS
TROUGH... SAYING THEY ARE ALL TOO AMPLIFIED AND FAST. A PREFERENCE
IS FOR A SLOWER SOLUTION...WHICH WOULD MATCH THE TREND SEEN WITH THE
08.00Z MODELS. THE SPEED OF THE TROUGH HAS BIG IMPACTS ON
WEDNESDAYS HIGHS...SINCE THE COLD AIR WOULD FLOW IN FASTER IN THE
08.12Z AND ESPECIALLY 09.00Z GFS/NAM SCENARIOS. EITHER WAY...THE
COLD AIR WILL EVENTUALLY FLOW INTO THE FORECAST AREA...WITH ALL
MODELS SHOWING 850MB TEMPS TANKING TO -16 TO -20C BY 12Z THURSDAY.
UNTIL MODELS RESOLVE THE TIMING...HAVE LEFT THE TEMPERATURE
FORECASTS MOSTLY ALONE...KEEPING TOO THAT FALLING TEMPERATURE TREND
WEDNESDAY AFTERNOON SINCE EVEN THE SLOWER SOLUTIONS WOULD SUGGEST
THAT. PRECIPITATION IS LOOKING HARDER AND HARDER TO COME BY WITH
THIS UPPER TROUGH. CERTAINLY THE DYNAMICS LOOK IMPRESSIVE...EVEN
WITH THE POSITIVELY TILTED SOLUTIONS WHICH HAVE ANYWHERE FROM 60-100
METER HEIGHT FALLS AT 500MB FOR WEDNESDAY AND AGAIN WEDNESDAY NIGHT.
HOWEVER...THE MOISTURE IS VERY LIMITED...DUE TO THE DRY AIRMASS
AHEAD OF THE TROUGH AND GULF OF MEXICO MOISTURE CUT-OFF FROM AN
UPPER LOW RIDING THROUGH THERE. MODELS AT BEST SHOW A COUPLE OF
HUNDREDTHS OF QPF COMING THROUGH THE FORECAST AREA...AND THAT IS
MOSTLY ON WEDNESDAY. THEREFORE...HAVE KEPT PRECIPITATION CHANCES IN
THE 20-50 RANGE FOR NOW.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
215 AM CST MON JAN 9 2012
09.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES AGREE IN GENERAL WITH
THE MEAN UPPER LEVEL PATTERN THROUGHOUT THE EXTENDED...WHICH
FEATURES MOSTLY TROUGHING OVER THE CENTRAL AND EASTERN U.S.. MOST OF
THIS TROUGHING STARTS FROM THAT POTENT TROUGH DROPPING DOWN INTO THE
FORECAST AREA WEDNESDAY NIGHT. THE TROUGHING THEN GETS REINFORCED BY
A SHORTWAVE DROPPING SOUTH THROUGH THE UPPER MIDWEST FRIDAY
NIGHT...PERHAPS CROSSING THE FORECAST AREA ON SATURDAY ACCORDING TO
SOME MODEL SOLUTIONS. THERE ARE INDICATIONS THAT RIDGING WILL BUILD
TOWARDS THE AREA ON SUNDAY DUE TO TROUGHING DROPPING DOWN INTO
BRITISH COLUMBIA AND WASHINGTON STATE.
THURSDAY THROUGH FRIDAY ARE LIKELY TO BE QUITE CHILLY...COMPARED TO
WHAT WE HAVE SEEN RECENTLY...WITH 850MB TEMPS DROPPING TO AROUND
-20C BY 00Z FRIDAY. MOSTLY CLOUDY SKIES WILL ALSO LIMIT DIURNAL
HEATING...THOUGH AT THE SAME TIME HELP TEMPERATURES FROM TANKING
THURSDAY NIGHT. SOME SLOW MODERATION IS ANTICIPATED FOR FRIDAY AS
THE CORE OF THE COLD AIR LIFTS OUT TO THE NORTHEAST...BUT STILL
READINGS SHOULD STAY BELOW NORMAL. THE SLOW MODERATION CONTINUES
THROUGH THE WEEKEND...ESPECIALLY ON SUNDAY WHEN THE RIDGING STARTS
BUILDING IN. THROUGHOUT THE LONG TERM PERIOD...FOLLOWED A CONSENSUS
OF GUIDANCE FOR TEMPERATURES.
PRECIPITATION CHANCES LOOKS PRETTY SLIM DUE TO AGAIN A LACK OF
MOISTURE. 09.00Z ECMWF HINTING THAT THERE COULD BE A LITTLE LIGHT
SNOW THURSDAY NIGHT WRAPPING AROUND...BUT IT IS THE ONLY MODEL
SHOWING IT. PLUS...WITH THE CONCERN MENTIONED IN THE WEDNESDAY
DISCUSSION ABOVE ABOUT THE ECMWF...NOT READY TO JUMP ON PUTTING
PRECIPITATION CHANCES IN FOR THURSDAY NIGHT. NEXT POTENTIAL TIME
PERIOD FOR PRECIPITATION CHANCES WOULD COME SATURDAY WITH THE
SHORTWAVE COMING THROUGH. HOWEVER...MODELS HAVE BEEN FAR FROM
CONSISTENT ON THE TRACK OF THIS SHORTWAVE...AND SOME HAVE IT GOING
NORTH AND SOUTH OF THE AREA FOR THIS 09.00Z CYCLE. THEREFORE...HAVE
MAINTAINED SATURDAY DRY TOO. THIS RESULTS IN THE ENTIRE LONG TERM
FORECAST DRY FOR NOW.
&&
.AVIATION...
1110 PM CST SUN JAN 8 2012
HIGH/MID LEVEL CLOUDS WILL BE ON THE INCREASE OVERNIGHT AS AN UPPER
LEVEL SHORTWAVE TROUGH DROPS SOUTHEAST ACROSS THE REGION. THE SFC
PRESSURE GRADIENT WILL ALSO TIGHTEN...WITH A SFC TROUGH SHIFTING THE
WINDS TO A MORE WESTERLY DIRECTION AROUND 18Z MON. BUFKIT SOUNDINGS
SUGGEST MIXING UP TO 1 KFT ON MONDAY...BUT THIS SHOULD BE ENOUGH FOR
GUSTY LATE MORNING/AFTERNOON CONDITIONS. SLACKENING PRESSURE
GRADIENT POST THE DEPARTING SHORTWAVE MONDAY NIGHT WILL RESULT IN
DECREASING WINDS...AND A SHIFT TO THE SOUTH/SOUTHWEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
215 AM CST MON JAN 9 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION....RIECK
AREA FORECAST DISCUSSION
NWS HASTINGS NE
352 AM CST WED JAN 11 2012
.SHORT TERM...TODAY THROUGH 12Z SATURDAY. MAIN FORECAST CONCERNS
WILL BE CHANCE FOR SNOW...WIND AND FALLING TEMPERATURES TODAY AND
TEMPERATURES THROUGH THE PERIOD.
SURFACE ANALYSIS AND OBSERVATIONS SHOW A COLD FRONT IN THE NORTHWEST
PART OF TE FORECAST AREA EARLY THIS MORNING. THE COLD FRONT WILL
CONTINUE TO PUSH THROUGH THE FORECAST AREA THROUGH THE REMAINDER OF
THE NIGHT. BEHIND THE FRONT WILL BE STRONG NORTHWEST WINDS AS
ALREADY EVIDENCED BY WINDS IN PORTIONS OF NORTH CENTRAL NEBRASKA.
THE WIND ADVISORY WILL CONTINUE BUT THE SOUTHEAST WILL BE A FEW
HOURS BEFORE THE WINDS INCREASE TO WIND ADVISORY CRITERIA.
AN UPPER LEVEL WAVE WILL MOVE THROUGH THE AREA TODAY. THERE WILL BE
SOME FRONTOGENESIS AS THE WAVE MOVES THROUGH AND WITH THE CLOUDS AND
MOISTURE AVAILABLE THERE WILL BE SOME FLURRIES ACROSS THE AREA. THE
QUESTION COMES IN WHETHER THERE WILL BE MORE THAN FLURRIES AND HAVE
SOME ACCUMULATION. MODELS HAVE SOME DIFFERENCES IN WHETHER THERE
WILL BE ACCUMULATION. THE NAM BRINGS VERY LIGHT QPF ACROSS THE AREA
BUT THE GFS AND ECMWF SPLITS THE PRECIPITATION AS IT MOVES ACROSS
THE AREA. WITH THE FRONTOGENESIS STRONGEST IN THE SOUTHEAST THIS
AFTERNOON HAVE PUT IN SOME LOW POPS BUT ONLY EXPECT LIGHT AMOUNTS.
TEMPERATURES ARE EXPECTED TO BE NEARLY STEADY OR EVEN FALL DURING
THE DAY AS COLDER AIR RUSHES IN BEHIND THE COLD FRONT. THE COLD AIR
LINGERS ACROSS THE AREA THROUGH THURSDAY NIGHT WITH HIGHS ONLY IN
THE 20S TO AROUND 30 AND LOWS 7 TO 15 DEGREES.
.LONG TERM...SATURDAY THROUGH TUESDAY. THE WARMING TREND WILL
CONTINUE INTO THE WEEKEND WITH SUNDAY SHAPING UP TO BE THE NICEST
DAY OF THE NEXT SEVEN. ANOTHER COLD FRONT WILL THEN COME THROUGH THE
REGION ON MONDAY RESULTING IN A COOL DOWN...WITH EVEN COLDER
TEMPERATURES BY TUESDAY.
THE TYPICAL MODEL ALL BLEND GUIDANCE USED IN THE EXTENDED PERIOD
CONTINUES TO NOT MAKE THE GRADE FOR SUNDAY AND WAS THROWN OUT IN
FAVOR OF THE BIAS CORRECTED ALL BLEND MODEL. THERE HAS BEEN A MODEL
COOL BIAS IN THE EXTENDED PERIODS NEARLY ALL WINTER DUE IN PART TO
THE LACK OF SNOW COVER...AND THE SET UP ON SUNDAY IS LIKELY GOING TO
BE ANOTHER EXAMPLE OF THIS MODEL COOL BIAS. FOR INSTANCE...850MB
TEMPERATURES YESTERDAY WERE AROUND 6-8C WITH LIGHT SOUTHWEST
WINDS...WHICH RESULTED IN HIGHS THAT WERE AROUND 60 DEGREES. 850MB
TEMPERATURES ON SUNDAY AS INDICATED IN BOTH THE 00Z GFS AND 00Z
ECMWF SHOULD AGAIN BE IN THE 6-8C RANGE WITH SOUTH WINDS AND PLENTY
OF SUNSHINE. THE MODEL ALL BLEND GUIDANCE ONLY GIVES US HIGHS IN THE
UPPER 40S TO AROUND 50. SEEMS LIKE THERE MAY BE A PROBLEM HERE WITH
THAT COOL BIAS IN THE MODEL GUIDANCE THAT HAS BEEN THERE ALL SEASON.
THEREFORE...USING THE BIAS CORRECTED GRIDS WE ARE NOW FORECASTING
HIGHS ON SUNDAY IN THE LOWER TO MID 50S...WHICH SHOULD BE A GOOD
IMPROVEMENT OVER THE BASIC MODEL GUIDANCE VALUES.
A STRONG COLD FRONT WILL SWING THROUGH AT SOME POINT ON
MONDAY...MAKING HIGHS VERY TRICKY TO FORECAST AS THEY WILL GREATLY
DEPEND ON THE TIMING OF THE FRONTAL PASSAGE. THE COLD AIR WILL MORE
ASSUREDLY HAVE INFILTRATED THE AREA BY TUESDAY...WHICH MAY KEEP MANY
AREAS FROM EVEN HITTING THE FREEZING MARK FOR HIGHS. DRY WEATHER
SEEMS LIKE IT WILL CONTINUE AS THESE FRONTS REALLY DO NOT HAVE MUCH
IN THE WAY OF MOISTURE ASSOCIATED WITH THEM.
&&
.PREV DISCUSSION... /ISSUED 1046 PM CST TUE JAN 10 2012/
AVIATION...06Z TAF. A STRONG COLD FRONT WILL MOVE ACROSS THE
REGION OVERNIGHT. THIS WILL TURN WINDS FROM THE SOUTHWEST TO A
NORTHWESTERLY DIRECTION AROUND 09Z...WITH THEM ALSO BECOMING
GUSTY. WINDS WILL BECOME EVEN STRONGER AFTER DAYBREAK WITH GUSTS
OF 36 KTS OR GREATER POSSIBLE. ANOTHER CONCERN WILL BE THE CHANCE
FOR LIGHT SNOW OR FLURRIES AS AN UPPER LEVEL DISTURBANCE MOVES
THROUGH THE REGION. THE LATEST NAM SUGGESTS THERE COULD BE LIGHT
SNOW...WHILE THE GFS IS STILL NOT SHOWING MUCH IN THE WAY OF QPF.
WILL CONTINUE WITH THE MENTION OF VCSH IN THE TAF FOR NOW SINCE
CONFIDENCE IN HOW MUCH SNOW/FLURRIES WILL ACTUALLY TAKE PLACE AT
KGRI IS LOW. CEILINGS WILL BE SOMETHING ELSE TO MONITOR WITH NAM
PROXIMITY SOUNDINGS SUGGESTING MVFR CONDITIONS WILL TAKE HOLD FOR
AT LEAST A FEW HOURS BEHIND THE COLD FRONT. THIS IS ALSO SHOWN BY
THE LATEST RUC SOUNDINGS...SO WILL HOLD ONTO THE MVFR CONDITIONS
IN THE TAF STARTING AROUND 11Z...BUT GO BACK TO VFR DURING THE
EARLY AFTERNOON AS PER THE NAM FORECAST SOUNDINGS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ039>041-046>049-
060>064-072>077-082>087.
KS...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR KSZ005>007-017>019.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
245 AM CST WED JAN 11 2012
.DISCUSSION...
COLD FRONT JUST BEGINNING TO ENTER NORTHWEST PORTION OF THE CWA AT
08Z WITH WIND SHIFT AT KBVN AND KYKN. COLDER AIR AND BAND OF
PRECIP LAGS BEHIND THE BOUNDARY HOWEVER WITH INITIAL WINDS
BOOSTING TEMPERATURES INTO THE LOWER 40S IMMEDIATELY BEHIND THE
BOUNDARY. 05Z HRRR MODEL HAS FRONT THROUGH MOST OF THE CWA BY 15Z
WITH THE COLDER AIR AND PRECIP JUST COMING INTO NORTHEAST
NEBRASKA AT THAT TIME. WINDS INCREASE ACROSS THE REMAINDER OF THE
CWA THEREAFTER...HAVE ADDED EASTERN PARTS OF THE CWA FROM
SOUTHEAST NEBRASKA INTO SOUTHWEST IOWA TO WIND ADVISORY AFTER 18Z.
A MIX OF RAIN AND SNOW SHOWERS POSSIBLE INITIALLY BEFORE CHANGING
TO ALL SNOW AS COLDER AIR MOVES IN. ONLY MINOR SNOWFALL EXPECTED
SINCE WIDTH OF PRECIP BAND FAIRLY NARROW AND SYSTEM MOVING THROUGH
QUICKLY. ANY REMAINING SNOW SHOWERS OR FLURRIES EXPECTED TO END
EARLY THIS EVENING IN THE FAR SOUTHEAST CORNER OF THE CWA.
TEMPERATURES...WIND AND SKY CONDITION THEN BECOME THE MAIN FOCUS
FOR TONIGHT INTO THURSDAY NIGHT AS UPPER LOW GRADUALLY SHIFTS
EAST. SLIGHTLY WARMER TEMPERATURES RETURN ON FRIDAY BUT ANY
WARMING LOOKS TO BE SHORT LIVED AS NEXT CLIPPER DROPPING INTO
NORTHERN MINNESOTA BY SATURDAY MORNING ALSO PULLS DOWN ANOTHER
BATCH OF COLD AIR WITH IT.
MORE SIGNIFICANT WARMING LIKELY EARLY IN THE EXTENDED PERIOD OVER
THE WEEKEND AS RIDGING MOVES INTO THE REGION AHEAD OF NEXT UPPER
WAVE COMING INTO THE PACIFIC NORTHWEST. ANOTHER COLD FRONT THEN
MOVES THROUGH ON MONDAY AS THE WAVE TRACKS EAST ACROSS THE PLAINS.
COLDEST AIR HOWEVER LOOKS TO STAY TO THE NORTH ALONG THE CANADIAN
BORDER AS UPPER FLOW BECOMES STRONGLY ZONAL...ESPECIALLY BY THE
ECMWF.
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
NO SIGNIFICANT CHANGES FROM PREVIOUS FORECAST...ALTHOUGH DID
TWEAK THE TIMING OF THE ARRIVAL OF THE COLD FRONT TO 11Z AT
KOFK...13Z AT KLNK AND 14Z AT KOMA. LATEST RUC TRENDS WOULD
SUGGEST THAT IT MIGHT EVEN BE EVENHOUR BEYOND THAT. FEEL THAT
SCATTERED SNOW SHOWERS WILL DEVELOP AT BOTH KOFK/KOMA BEHIND THE
FRONT...ALTHOUGH NOT AS CONFIDENT THAT THEY WILL DEVELOP AT KLNK.
ALSO UNCERTAIN HOW LOW VISIBILITIES WILL DROP...GIVEN 25 TO 35 MPH
WINDS WITH HIGHER GUSTS. AM SEEING SEVERAL UPSTREAM REPORTS IN THE
3 MILE RANGE WITH SNOW...SO USED THAT AS A BEST ESTIMATE UNTIL THE
SNOW BAND GETS A LITTLE CLOSER
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
NEZ067-068-090>093.
WIND ADVISORY FROM 8 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR NEZ015-033-034-043>045-050>053-065-066-078-088-089.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-012-016>018-
030>032-042.
IA...WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
IAZ055-056-069-079-080-090-091.
WIND ADVISORY FROM 8 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR IAZ043.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1137 PM CST TUE JAN 10 2012
.AVIATION...06Z TAFS FOR KOMA...KLNK...KOFK. NO SIGNIFICANT
CHANGES FROM PREVIOUS FORECAST...ALTHOUGH DID TWEAK THE TIMING OF
THE ARRIVAL OF THE COLD FRONT TO 11Z AT KOFK...13Z AT KLNK AND 14Z
AT KOMA. LATEST RUC TRENDS WOULD SUGGEST THAT IT MIGHT EVEN BE
EVENHOUR BEYOND THAT. FEEL THAT SCATTERED SNOW SHOWERS WILL
DEVELOP AT BOTH KOFK/KOMA BEHIND THE FRONT...ALTHOUGH NOT AS
CONFIDENT THAT THEY WILL DEVELOP AT KLNK. ALSO UNCERTAIN HOW LOW
VISIBILITIES WILL DROP...GIVEN 25 TO 35 MPH WINDS WITH HIGHER
GUSTS. AM SEEING SEVERAL UPSTREAM REPORTS IN THE 3 MILE RANGE WITH
SNOW...SO USED THAT AS A BEST ESTIMATE UNTIL THE SNOW BAND GETS A
LITTLE CLOSER.
DEWALD
&&
.PREV DISCUSSION... /ISSUED 927 PM CST TUE JAN 10 2012/
DISCUSSION...
MADE SOME MINOR TWEAKS TO THE FORECAST FOR PRECIPITATION TOMORROW...
MAINLY INCREASING THE AREAL COVERAGE OF SOME LIGHT SNOW OR FLURRIES
THAT SHOULD MOVE THROUGH THE REGION. THIS LOOKS LIKE A HIGHER
PROBABILITY OF OCCURRENCE...BUT GENERALLY LOW AMOUNTS EXPECTED.
ALSO BELIEVE THAT THE COLDER AIR WILL RUSH IN FAST ENOUGH BEHIND
THE FRONT THAT IT WILL PROBABLY BE ALL SNOW. SNOWFALL AMOUNTS
WOULD RANGE LESS THAN ONE HALF INCH...BUT WITH 25 TO 35 MPH
WINDS...REDUCED VISIBILITY WILL BE POSSIBLE. MADE OTHER MINIMAL
CHANGES TO TEMPS...RAISING OVERNIGHT LOWS IN MOST SPOTS A COUPLE
OF DEGREES...ALTHOUGH A COUPLE OF SPOTS HAD ALREADY BOTTOMED OUT
BELOW PREVIOUS FORECAST BECAUSE WINDS WENT CALM...SO MADE SO
MESOSCALE ADJUSTMENTS FOR THAT. BELIEVE THAT TEMPS WILL FALL
BEHIND THE FRONT TOMORROW...AND SHOULD RISE A BIT AHEAD OF THE
FRONT IN THE MORNING...BUT THEN FALL IN THOSE AREAS IN THE
AFTERNOON.
DEWALD
PREV DISCUSSION... /ISSUED 505 PM CST TUE JAN 10 2012/
AVIATION...00Z TAFS FOR KOMA...KLNK AND KOFK.
A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA THIS PERIOD WILL
BE THE MAIN CHALLENGE... ARRIVING AT KOFK BY 11Z...KLNK BY 12Z...AND
KOMA BY 13Z. LIGHT SOUTH SOUTHWEST WINDS AHEAD OF THE FRONT...BUT
WINDS SHOULD ABRUPTLY SHIFT TO THE NORTHWEST AROUND 320 TO 340
DEGREES AND SUBSTANTIALLY INCREASE ONCE THE FRONT ARRIVES.
SUSTAINED WINDS WILL LIKELY INCREASE TO 26 TO 29KTS...WITH GUSTS
UP TO 34 TO 38 KTS BEHIND THE FRONT. AM ALSO EXPECTING MVFR
CEILINGS IMMEDIATELY BEHIND THE COLD FRONT AS WELL...THAT COULD
BRIEFLY BE IFR FOR AN HOUR OR TWO. COULD ALSO SEE SOME SNOW
FLURRIES FOR A PERIOD BEHIND THE FRONT ALSO...AS COLDER AIR RUSHES
INTO THE REGION COMBINED WITH AN INCREASE IN MOISTURE.
DEWALD
PREV DISCUSSION... /ISSUED 325 PM CST TUE JAN 10 2012/
SHORT TERM...TONIGHT THROUGH FRIDAY.
THE PRIMARY FORECAST CONCERNS DURING THIS PERIOD ARE WINDS FROM
LATE TONIGHT THROUGH WEDNESDAY AFTERNOON...SMALL CHANCES FOR
PRECIPITATION AND TEMPERATURES.
WATER VAPOR SATELLITE IMAGERY EARLY THIS AFTERNOON SHOWED A FAIRLY
STRONG SHORTWAVE TROUGH DROPPING SOUTHEAST TOWARD THE AREA FROM THE
ROCKY MOUNTAIN REGION. 12 HOUR HEIGHT FALLS WITH THIS FEATURE WERE
ESTIMATED AT UP TO 140 METERS AT 12Z. THIS WAVE WILL HELP DRIVE A
STRONG COLD FRONT THROUGH THE AREA LATE TONIGHT AND EARLY WEDNESDAY
MORNING. WENT AHEAD AND ISSUED A WIND ADVISORY FOR MUCH OF NORTHEAST
NEBRASKA STARTING AROUND 3 AM CST AND CONTINUED THAT UNTIL 6 PM.
ALSO WENT WITH AN ADVISORY ABOUT AS FAR SOUTHEAST AS ONAWA...OMAHA...
LINCOLN AND BEATRICE FROM 8 AM TO 6 PM. THIS ADVISORY MAY NEED SOME
ADJUSTMENT LATER. PRESSURE GRADIENT AHEAD OF THE FRONT REMAINS WEAK
TONIGHT SO SURFACE WINDS SHOULD BE RELATIVELY TONIGHT UNTIL FRONTAL
PASSAGE. WINDS WILL INCREASE DRAMATICALLY WITH FRONTAL PASSAGE DUE
TO INCREASED PRESSURE GRADIENT AND PRESSURE RISES. 12Z NAM INDICATED
3 HOUR PRESSURE RISES OF 3-4 MB MOVING INTO NORTHEAST NEBRASKA BY
12Z WEDNESDAY...THEN FOR A GOOD PORTION OF THE AREA BY 15Z. 925 MB
WINDS ALSO INCREASE TO 35-40 KNOTS WEDNESDAY MORNING.
TEMPERATURES SHOULD BE STEADY OR SLOWLY FALLING BY LATE MORNING IN
THE NORTHWEST HALF OF THE FORECAST AREA...THEN FOR THE REST OF THE
AREA BY EARLY AFTERNOON. FORCING AND MOISTURE APPEAR ADEQUATE FOR
SCATTERED LIGHT SNOW SHOWERS...SOME OF WHICH COULD PRODUCE A FEW
TENTHS OF AN INCH OF ACCUMULATION. MODELS SUGGEST THAT THE CHANCE
FOR MEASURABLE SNOW IS THE HIGHEST ACROSS SOUTHEAST NEBRASKA AND
SOUTHWEST IOWA. SOME FLURRIES COULD ALSO OCCUR IN PARTS OF THE AREA
WEDNESDAY NIGHT INTO THURSDAY. THURSDAY IS FORECAST TO BE THE
COLDEST DAY OF THE WEEK...WITH HIGHS MOSTLY 20 TO 25.
THIS COLDER WEATHER IS SHORT LIVED...AS WARMER AIR STARTS TO SPREAD
IN FROM THE WEST BY LATE FRIDAY. HIGHS FRIDAY SHOULD REACH THE 30S
WEST AND 20S EAST.
MILLER
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY.
THE MAIN FORECAST CHALLENGES IN THE EXTENDED WILL BE TEMPERATURES.
THE GENERAL PATTERN CONTINUES WITH NORTHWEST FLOW ALOFT AND FREQUENT
FRONTAL PASSAGES.
A FAST MOVING SHORTWAVE TROF WILL PASS THROUGH THE UPPER MISSISSIPPI
VALLEY AND GREAT LAKES FRIDAY NIGHT. THERE IS COLD AIR ADVECTION
SATURDAY BUT GOOD MIXING SHOULD PUSH HIGHS ABOVE FRIDAY/S
READINGS. WARMER AIR WILL RETURN SUNDAY AND MONDAY AS A MID LEVEL
RIDGE BUILDS IN. THE NEXT FRONT MOVES THROUGH MONDAY. MODERATING
HIGHS ARE FORECAST FOR SATURDAY WITH HIGHS IN THE 30S/40S...AND
WARMER READINGS FOR SUNDAY IN THE 40S AND 50S. MONDAY WILL BE TRICKY
AS ALLBLEND TEMPERATURES ARE ONLY IN THE 30S TO LOWER 40S. THE ECWMF
HAS THE FRONT JUST STARTING TO MOVE THROUGH BY MIDDAY MONDAY AND THE
GFS TRIES TO PULL CLOUDS NORTHWARD...HOWEVER THESE CLOUDS ARE ABSENT
IN THE ECMWF/GEM. WITH WEDGE OF HIGHER H85 TEMPS OVER THE
CWA...WENT ABOVE ALLBLEND AND HAVE HIGHS IN THE 40S MONDAY AND
COOLER 20S/30S FOR TUESDAY.
ZAPOTOCNY
AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK
VFR CONDITIONS AND LIGHT SOUTHWEST WINDS WILL CONTINUE THROUGH
THE EVENING HOURS BUT THIS WILL CHANGE AS A STRONG COLD FRONT
DIVES INTO THE REGION AFTER 06Z. BEHIND THE FRONT...WE EXPECT A
SHORT PERIOD OF MVFR CIGS AND THEN A QUICK DROP TO AN IFR DECK.
SFC WINDS WILL INCREASE TO NEAR 25 TO 30 KTS WITH GUSTS UP TO 35
KTS BY 18Z.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 8 AM TO 6 PM CST WEDNESDAY FOR NEZ015-033-034-
043>045-050>053-065-066-078-088-089.
WIND ADVISORY FROM 3 AM TO 6 PM CST WEDNESDAY FOR NEZ011-012-
016>018-030>032-042.
IA...WIND ADVISORY FROM 8 AM TO 6 PM CST WEDNESDAY FOR IAZ043.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1046 PM CST TUE JAN 10 2012
.AVIATION...06Z TAF. A STRONG COLD FRONT WILL MOVE ACROSS THE
REGION OVERNIGHT. THIS WILL TURN WINDS FROM THE SOUTHWEST TO A
NORTHWESTERLY DIRECTION AROUND 09Z...WITH THEM ALSO BECOMING
GUSTY. WINDS WILL BECOME EVEN STRONGER AFTER DAYBREAK WITH GUSTS
OF 36 KTS OR GREATER POSSIBLE. ANOTHER CONCERN WILL BE THE CHANCE
FOR LIGHT SNOW OR FLURRIES AS AN UPPER LEVEL DISTURBANCE MOVES
THROUGH THE REGION. THE LATEST NAM SUGGESTS THERE COULD BE LIGHT
SNOW...WHILE THE GFS IS STILL NOT SHOWING MUCH IN THE WAY OF QPF.
WILL CONTINUE WITH THE MENTION OF VCSH IN THE TAF FOR NOW SINCE
CONFIDENCE IN HOW MUCH SNOW/FLURRIES WILL ACTUALLY TAKE PLACE AT
KGRI IS LOW. CEILINGS WILL BE SOMETHING ELSE TO MONITOR WITH NAM
PROXIMITY SOUNDINGS SUGGESTING MVFR CONDITIONS WILL TAKE HOLD FOR
AT LEAST A FEW HOURS BEHIND THE COLD FRONT. THIS IS ALSO SHOWN BY
THE LATEST RUC SOUNDINGS...SO WILL HOLD ONTO THE MVFR CONDITIONS
IN THE TAF STARTING AROUND 11Z...BUT GO BACK TO VFR DURING THE
EARLY AFTERNOON AS PER THE NAM FORECAST SOUNDINGS.
&&
.PREV DISCUSSION... /ISSUED 359 PM CST TUE JAN 10 2012/
SHORT TERM...TONIGHT THROUGH WEDNESDAY. THE WEATHER PATTERN WILL
UNDERGO CHANGES BEGINNING TONIGHT...RETURNING TO THE WINTRY FEEL. AN
UPPER SHORTWAVE TROUGH EXTENDING FM BRITISH COLUMBIA INTO MT/ID WILL
DIG SOUTH ACROSS THE NORTHERN AND CENTRAL PLAINS TONIGHT AND
WEDNESDAY. AN ASSOCIATED STRONG COLD FRONTAL BOUNDARY WILL REACH
OUR NW CWA AROUND MIDNIGHT AND SWEEP SOUTHEAST THRU OUR CWA BY
DAYBREAK. SIX HOUR PRESSURE RISES BEHIND THE FRONT AVERAGE 4-8MB
AND A VERY TIGHT PRESSURE GRADIENT WILL BE IN PLACE ACROSS THE
CENTRAL PLAINS WEDNESDAY AS A 1038MB SURFACE HIGH BUILDS INTO THE
NORTHERN ROCKIES. H85 WINDS AVERAGE 45 TO 55KTS AND FORECAST
SOUNDINGS INDICATE MIXING BETWEEN H85 AND H8. RESULTANT SURFACE WIND
SPEEDS SHOULD AVERAGE NEAR 30 MPH WITH GUSTS NEAR 40 MPH...AND DUE
TO THE EXPECTED INTENSE WINDS WILL GO AHEAD WITH A WIND ADVISORY.
WILL BEGIN ADVISORY AT 4 AM AS FRONT WILL BE HALFWAY THRU THE CWA AT
THIS TIME...WITH WINDS IN THE SOUTHEAST CWA PICKING UP A FEW HOURS
LATER AFTER DAYBREAK. WINDS WILL REMAIN STRONG/GUSTY ALL DAY BEFORE
SUBSIDING IN EVENING.
MUCH COLDER AIR WILL ADVECT SOUTH INTO OUR CWA FOLLOWING FROPA
TONIGHT/WEDNESDAY. AFTER UNSEASONABLY WARM TEMPS EARLY THIS WEEK IN
THE 55 TO 60 DEGREE RANGE...TEMPS WILL PLUMMET CLOSER TO SEASONAL
NORMALS IN THE COLDER AIRMASS WITH LOW TO MID 30S EXPECTED. H85
TEMPS WHICH HAVE AVERAGED 7-C THE PAST COUPLE OF DAYS WILL PLUMMET
TO -8 TO -11C BY WED EVENING. VERY LITTLE DIURNAL TEMP RANGE IS
EXPECTED WEDNESDAY FM EARLY MORNING TEMPS IN THE UPPER 20S...AND
THIS WILL FEEL MARKEDLY COLDER WHEN COMBINED WITH THE STRONG
WINDS...AND APPARENT TEMPERATURES OR WIND CHILLS WILL AVERAGE IN THE
TEENS.
IN ADDITION TO THE MARKEDLY COLDER AIR AND STRONG WINDS...A DECENT
PERIOD OF FRONTOGENETIC FORCING BETWEEN H85 AND H5 IS PRESENT
BEGINNING TOWARD DAWN WEDNESDAY IN OUR NW CWA...WHICH SWEEPS SE WITH
FROPA. IN STRONG CAA/FRONTOGENESIS AND UPPER DYNAMICS AS
UPPER TROUGH MOVES IN WEDNESDAY...CANNOT RULE OUT POTENTIAL FOR SOME
LIGHT WINTRY PCPN. ATTM...MEASURABLE SNOWFALL IS NOT APPEARING
LIKELY HOWEVER DO THINK THERE WILL BE A TIME FRAME TOMORROW WHEN A
SNOW SHOWER OR FLURRIES ARE POSSIBLE. WILL TREND WITH OCCASIONAL
FLURRIES FOR NOW AND IF SNOW POTENTIAL LOOKS MORE SIGNIFICANT WITH
SUBSEQUENT RUNS...POPS CAN BE ADDED.
LONG TERM...WEDNESDAY EVENING THROUGH NEXT TUESDAY. PRIMARY
CHALLENGES INCLUDE FLURRY CHANCES EARLY ON...FOLLOWED BY TRYING TO
NAIL DOWN A BIT OF A TEMPERATURE ROLLER COASTER...AS THE
PERSISTENTLY MILD PATTERN ABATES FOR AT LEAST AWHILE. IN
ADDITION...CONCERNS ABOUT CRITICAL FIRE WEATHER CONDITIONS
CONTINUE TO GROW FOR THURSDAY...AND THIS IS EXCLUSIVELY COVERED
IN THE SEPARATE FIRE WEATHER SECTION BELOW.
STARTING OFF WEDNESDAY EVENING/NIGHT...THE CWA SHOULD BE SETTLING
DOWN A BIT FROM THE ADVISORY LEVEL WINDS OF THE DAYTIME
HOURS...BUT BY NO MEANS WILL NORTHWEST WINDS BE LIGHT THROUGH THE
NIGHT...AS SUSTAINED SPEEDS OF AT LEAST 15-25 MPH WITH HIGHER
GUSTS PREVAIL. ON THE LARGER SCALE ALOFT...12Z ECMWF/GFS/NAM ALL
DEPICT A SHARPENING...COLD TROUGH DROPPING SOUTH THROUGH THE HEART
OF THE CENTRAL PLAINS...WITH 850MB TEMPS CRASHING DOWN INTO THE
-13 TO -17C RANGE BY 12Z. STARTING WITH PRECIP CHANCES...OPTED TO
LEAVE RISK OF MEASURABLE SNOW BELOW 20 PERCENT...BUT KEPT CHANCE
OF FLURRIES GOING ACROSS MAINLY THE SOUTHEAST 1/3 OF THE CWA IN
THE EVENING...AND ACROSS MUCH OF THE EAST/NORTHEAST THROUGH THE
NIGHT. TRUTH IS...WITH SUCH A COLD POCKET ALOFT AND SHARP VORT MAX
PASSING OVERHEAD...PROBABLY JUST SHOULD HAVE ASSIGNED CHANCE OF
FLURRIES CWA-WIDE...BUT TRACK OF THE SYSTEM WOULD SUGGEST THAT
MUCH OF THE WESTERN CWA IS LEAST LIKELY TO SEE ANY FLAKES. BOTTOM
LINE IS...ANY LIGHT SNOW/FLURRIES WEDNESDAY NIGHT SHOULD BE VERY
MINIMAL IF IT EVEN OCCURS AT ALL. FOR LOW TEMPS...KEPT LOWS
SIMILAR TO PREVIOUS FORECAST...WITH 10-15 ACROSS MOST OF THE CWA.
THIS CONTINUES TO BE 4-5 DEGREES ABOVE MET/MAV GUIDANCE
CONSENSUS...WHICH JUST LOOKS TOO COLD GIVEN WINDS AND RESULTANT
MIXING STAYING UP. ALTHOUGH THE LOW TEMPS THEMSELVES ARE NOT ALL
THAT NOTABLE...WIND CHILL VALUES WILL DROP INTO THE ZERO TO -10
RANGE ACROSS MOST OF THE CWA WED NIGHT INTO THURS MORNING...WHICH
WILL BE QUITE A SLAP IN THE FACE.
THURSDAY...KEPT ALL FLURRY MENTION OUT FOR NOW...BUT WITH WESTERN
EDGE OF MID LEVEL LOW COLD CORE/CIRCULATION LINGERING CLOSE TO THE
EASTERN CWA...LATER SHIFTS WILL HAVE TO WATCH FOR FLURRY
POTENTIAL ALTHOUGH BETTER CHANCES WILL RESIDE FROM NORTHEAST NEB
INTO IA. TEMP WISE...THURS IS STILL LOOKING LIKE THE COLDEST DAY
SINCE AT LEAST DEC. 9TH FOR MOST OF THE CWA...AND CHANGED HIGHS
LITTLE RANGING FROM LOW 20S NORTHEAST TO NEAR 30 FAR SOUTHWEST.
MAIN CHANGE TO THURSDAY WAS RAISING WIND SPEEDS AT LEAST 5
MPH...AS CONTINUED SURFACE PRESSURE GRADIENT BETWEEN GREAT LAKES
LOW AND NORTHERN ROCKIES HIGH...ALONG WITH MIXING TO AT LEAST
850MB...WILL PROMOTE SUSTAINED NORTHWEST SPEEDS AT LEAST INTO THE
20-25 MPH RANGE MOST AREAS. ALTHOUGH NOT LOOKING LIKELY AT THIS
POINT...CAN/T EVEN RULE OUT SUSTAINED SPEEDS FLIRTING WITH
ADVISORY CRITERIA OF 30 MPH AND WILL NEED TO WATCH.
OTHERWISE...MODELS SUCH AS ECMWF/GFS CONTINUE TO INSIST THAT SOME
EXTREMELY DRY AIR WILL WORK ACROSS THE AREA...WITH SURFACE
DEWPOINTS POTENTIALLY FALLING UNDER -20F. ALTHOUGH HAVE NOT GONE
THAT LOW JUST YET...HAVE TRENDED DOWNWARD. BREEZES WILL BE A BIT
LIGHTER THURS NIGHT VERSUS WED NIGHT...BUT KEPT LOWS UP MAINLY
BETWEEN 9-14 DEGREES AS LACK OF SNOW COVER SHOULD PRECLUDE MORE OF
A DROP TOWARD ZERO.
FRIDAY/FRIDAY NIGHT...ECMWF/GFS ARE IN REASONABLE AGREEMENT WITH
THE MID/UPPER PATTERN...AS THE AFOREMENTIONED SYSTEM MOVES OFF
INTO THE EASTERN CONUS...BUT ANOTHER QUICK MOVING LOW AMPLITUDE
SHORTWAVE DROPS DOWN INTO THE REGION IN STRONG NORTHWEST FLOW
ALOFT. ANY RISK OF FLURRIES FRIDAY NIGHT LOOKS TO STAY AT LEAST A
FEW HUNDRED MILES NORTH/NORTHEAST OF THE CWA. FOR HIGH TEMPS
FRIDAY...WESTERLY LOW LEVEL FLOW RESULTS IN MODEST WARMING...AND
CHANGED HIGHS LITTLE WITH MID/UPPER 30S MOST AREAS...AND SOME LOW
40S SOUTHWEST.
SATURDAY/SAT NIGHT...MID LEVEL HEIGHTS STEADILY RISE AS BROAD
RIDGING OVERSPREAD MUCH OF THE WESTERN/CENTRAL CONUS...KEEPING IT
DRY. WITH A WEST/NORTHWEST DOWNSLOPE SURFACE WIND COMPONENT IN
PLACE...A CONTINUED MODEST WARMING TREND IS LIKELY...AND CHANGED
HIGHS LITTLE WITH LOW 40S NORTH TO UPPER 40S SOUTH.
SUNDAY/SUNDAY NIGHT...THIS IS STILL LOOKING LIKE THE WARMEST PART
OF THE FORECAST PERIOD...AS BOTH THE ECMWF/GFS NOW DEPICT STRONG
WARM AIR ADVECTION AT 850MB WITH TEMPS RISING INTO THE +8-12C
RANGE DURING THE DAY. ALTHOUGH SURFACE WINDS WILL BE MORE
SOUTHERLY THAN WESTERLY...KEPT TREND GOING FROM PREVIOUS FORECAST
OF AIMING ABOVE MODEL CONSENSUS FOR HIGH TEMPS...AND HAVE MOST OF
THE CWA IN THE 49-52 RANGE WITH SOME MID 50S POSSIBLE IN THE WEST.
MONDAY INTO TUESDAY...REASONABLE MODEL AGREEMENT CONTINUES FOR
6-7 DAYS OUT THAT THE NEXT BROAD TROUGH MOVING IN FROM THE WEST
WILL HELP DRIVE THE NEXT SIGNIFICANT COLD FRONT SOUTHWARD ACROSS
THE REGION. WITH THE MAIN PUSH OF COLD AIR LIKELY HOLDING OFF
UNTIL MONDAY NIGHT...OR AT LEAST LATER IN THE DAY...STILL HAVE
HIGHS REACHING THE LOW-MID 40S BUT THIS IS VERY DEPENDENT ON
FRONTAL TIMING AND IS SUBJECT TO MODIFICATION. ALTHOUGH SOME
LIGHT SNOW/FLURRIES CANNOT BE RULED OUT MON NIGHT INTO
TUESDAY...WILL KEEP OUT ALL PRECIP MENTION FOR NOW. BY TUESDAY
THIS NEXT BATCH OF COLD AIR SHOULD BE FIRMLY IN PLACE...AND HAVE
HIGHS RANGING UPPER 20S NORTHEAST TO MID 30S SOUTHWEST.
FIRE WEATHER...AS MENTIONED ABOVE...CONCERNS ARE INCREASING FOR A
SOMEWHAT RARE CRITICAL FIRE WEATHER SITUATION FOR THURSDAY.
THE RARITY IS BECAUSE AFTERNOON HIGH TEMPERATURES WILL ONLY BE IN
THE 20S ACROSS MOST OF THE CWA/DISTRICT...WHICH USUALLY IS TOO
COLD TO WARRANT A HIGH LEVEL OF FIRE WEATHER CONCERN.
HOWEVER...MODELS HAVE BEEN INSISTENT THAT EXTREMELY DRY AIR WILL
INVADE THE REGION...WITH SURFACE DEWPOINTS POTENTIALLY CRASHING TO
AROUND -20F DURING THE DAY. THE END RESULT IS THAT RELATIVE
HUMIDITY VALUES ARE NOW FORECAST TO DROP BELOW 20 PERCENT FOR AT
LEAST A FEW HOURS ESPECIALLY ACROSS THE WESTERN/CENTRAL CWA. THESE
LOW RH VALUES...COMBINED WITH SUSTAINED WINDS EASILY AT/OVER 20
MPH THROUGH THE DAY AND DRY VEGETATION...BRINGS RED FLAG WARNING
CRITERIA INTO PLAY...AND THIS WILL NEED CLOSELY MONITORED OVER THE
NEXT FEW DAYS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM 4 AM TO 6 PM CST WEDNESDAY FOR NEZ039>041-
046>049-060>064-072>077-082>087.
KS...WIND ADVISORY FROM 4 AM TO 6 PM CST WEDNESDAY FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...FAY
LONG TERM/FIRE WEATHER...PFANNKUCH
AVIATION...KING
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1128 PM CST TUE JAN 10 2012
.AVIATION...
CONCERNS...FOG POTENTIAL AROUND DAYBREAK.
WE/VE REMOVED IFR AND MVFR FOG FOR ALL SITES DUE TO THE EXPECTATION
THAT WESTERLY WINDS WILL REMAIN UP OVERNIGHT. IF WINDS GO CALM
FOR MORE THAN 2 HOURS...THEN 3-5SM BR OR GROUND FOG COULD FORM AND
LAST UNTIL 15Z. THE RUC MODEL WEAKENS SURFACE WINDS AROUND
DAYBREAK WHILE THE OTHER MODELS KEEP THEM UP 3-6KTS. WILL MONITOR
3.9 IR SATELLITE FOR DEVELOPMENT LATE TONIGHT.
A STRONG COLD FRONT TO PLOW THROUGH NORTH AND CENTRAL TEXAS LATE
WEDNESDAY AFTERNOON AND EARLY EVENING. FROPA FOR THE METROPLEX
TAF SITES WILL BE 23-00Z AND KACT BY 01Z. NORTHWESTERLY WINDS WILL
INCREASE TO 24G33KT SEVERAL HOURS BEHIND FROPA ACROSS THE
METROPLEX. IF GUSTS REACH 35 KTS OR HIGHER...A KDFW AIRPORT
WEATHER WARNING WOULD BE REQUIRED. 75
&&
.PREV DISCUSSION... /ISSUED 338 PM CST TUE JAN 10 2012/
BEST MID-LEVEL LAPSE RATES ARE NOW CONFINED TO ARKANSAS...AND
UPPER LOW HAS BEEN EFFECTIVELY CUT OFF FROM SUBTROPICAL PLUME. DRY
AIR CONTINUES TO ENTRAIN INTO THE CORE OF SYSTEM...AND SHOULD
LIMIT ADDITIONAL PRECIP TO SPRINKLES/DRIZZLE. UPPER LOW WILL REACH
EASTERN EXTENT OF THE FWD CWA AROUND NIGHTFALL.
DEEP SUBSIDENCE WILL FOLLOW TONIGHT...WITH WEAK SURFACE RIDGING
DIMINISHING WINDS. WITH CLEAR SKIES AND LIGHT WINDS...THE SURFACE
LAYER SHOULD QUICKLY SATURATE. SHALLOW FOG IS LIKELY AREAWIDE.
SUBTLE DRY ADVECTION FROM THE WEST SHOULD PREVENT WIDESPREAD DENSE
FOG...BUT THE VISIBILITY IS EXPECTED TO FALL BELOW ONE MILE AT
SOME LOCATIONS. THE SHALLOW NATURE OF THE FOG AND INCREASING
SOUTHWEST WINDS AHEAD OF APPROACHING FRONT SHOULD ALLOW FOG TO
DISSIPATE MORE EFFECTIVELY THAN TYPICAL JANUARY FOG EVENTS.
SUNNY SKIES AND DRYING DOWNSLOPE WINDS WILL BUOY TEMPERATURES INTO
THE 60S ON WEDNESDAY. THE MILD WEATHER WILL BE SHORT-LIVED AS COLD
FRONT WILL INVADE NORTHWEST PORTIONS OF CWA AROUND SUNSET. SURFACE
BOUNDARY IS CURRENTLY IN THE DAKOTAS...BUT WILL QUICKLY SPILL
SOUTH. WIND CHILLS WILL PLUMMET INTO THE TEENS BY DAYBREAK
THURSDAY. A BLUSTERY DAY WILL FOLLOW. AFTERNOON TEMPERATURES WILL
RETURN TO NORMAL BY SATURDAY.
A STRAY SHORTWAVE CURRENTLY OFF THE COAST OF SAN FRANCISCO WILL
CUT OFF. GUIDANCE CONTINUES TO STRUGGLE WITH EVOLUTION OF FEATURE
NEXT WEEK. ONCE THE LOW EJECTS...IT SHOULD BECOME AN OPEN WAVE
WHEN IT REACHES THE SOUTHERN PLAINS...THUS ANY RAIN EVENT WOULD
BE BRIEF. TO AVOID SPREADING 20 POPS THROUGHOUT AN EXTENDED
PERIOD...WILL MAINTAIN SHOWERS ONLY MONDAY AND MONDAY NIGHT...
DESPITE UNCERTAINTY IN TIMING.
25
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 37 65 31 45 28 / 10 0 0 0 0
WACO, TX 34 66 31 48 23 / 10 0 0 0 0
PARIS, TX 36 61 27 41 22 / 10 0 5 0 0
DENTON, TX 34 63 25 44 22 / 10 0 0 0 0
MCKINNEY, TX 35 62 30 43 22 / 10 0 0 0 0
DALLAS, TX 38 66 32 44 31 / 10 0 0 0 0
TERRELL, TX 36 66 31 45 24 / 10 0 0 0 0
CORSICANA, TX 37 66 32 46 26 / 10 0 0 0 0
TEMPLE, TX 34 68 30 46 23 / 5 0 0 0 0
MINERAL WELLS, TX 33 64 24 46 23 / 10 0 0 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
75/
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
516 AM CST WED JAN 11 2012
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
A STRONG COLD FRONT THAT PUSHED THROUGH KOFK BEFORE TAF ISSUANCE
WILL QUICKLY MOVE ACROSS KOMA/KLNK WITH SURFACE WINDS EASILY
GUSTING OVER 30KTS. LOW CLOUDS IN THE LOW MVFR CATEGORY...POSSIBLY
IFR CATEGORY AT KOFK...WILL MOVE IN AN HOUR OR TWO AFTER FRONT
PASSES. IN ADDITION...SNOW SHOWERS THAT ARE LIKELY LATER THIS
MORNING MORNING THROUGH THIS AFTERNOON COULD REDUCE VISIBILITIES
DOWN TO 3 OR 4 MILES. ALTHOUGH THERE WAS SOME INDICATION THE
INTENSITY WOULD WEAKEN COMPARED TO UPSTREAM CONDITIONS WHERE SOME
VISIBILITIES DROPPED BELOW 1 MILE...CONFIDENCE NOT HIGH. LOW
CEILINGS AND ADDITIONAL SNOW SHOWERS/FLURRIES LIKELY LATER TONIGHT
AS SECOND DISTURBANCE MOVES ACROSS THE REGION.
CHERMOK
&&
.PREV DISCUSSION... /ISSUED 245 AM CST WED JAN 11 2012/
DISCUSSION...
COLD FRONT JUST BEGINNING TO ENTER NORTHWEST PORTION OF THE CWA AT
08Z WITH WIND SHIFT AT KBVN AND KYKN. COLDER AIR AND BAND OF
PRECIP LAGS BEHIND THE BOUNDARY HOWEVER WITH INITIAL WINDS
BOOSTING TEMPERATURES INTO THE LOWER 40S IMMEDIATELY BEHIND THE
BOUNDARY. 05Z HRRR MODEL HAS FRONT THROUGH MOST OF THE CWA BY 15Z
WITH THE COLDER AIR AND PRECIP JUST COMING INTO NORTHEAST
NEBRASKA AT THAT TIME. WINDS INCREASE ACROSS THE REMAINDER OF THE
CWA THEREAFTER...HAVE ADDED EASTERN PARTS OF THE CWA FROM
SOUTHEAST NEBRASKA INTO SOUTHWEST IOWA TO WIND ADVISORY AFTER 18Z.
A MIX OF RAIN AND SNOW SHOWERS POSSIBLE INITIALLY BEFORE CHANGING
TO ALL SNOW AS COLDER AIR MOVES IN. ONLY MINOR SNOWFALL EXPECTED
SINCE WIDTH OF PRECIP BAND FAIRLY NARROW AND SYSTEM MOVING THROUGH
QUICKLY. ANY REMAINING SNOW SHOWERS OR FLURRIES EXPECTED TO END
EARLY THIS EVENING IN THE FAR SOUTHEAST CORNER OF THE CWA.
TEMPERATURES...WIND AND SKY CONDITION THEN BECOME THE MAIN FOCUS
FOR TONIGHT INTO THURSDAY NIGHT AS UPPER LOW GRADUALLY SHIFTS
EAST. SLIGHTLY WARMER TEMPERATURES RETURN ON FRIDAY BUT ANY
WARMING LOOKS TO BE SHORT LIVED AS NEXT CLIPPER DROPPING INTO
NORTHERN MINNESOTA BY SATURDAY MORNING ALSO PULLS DOWN ANOTHER
BATCH OF COLD AIR WITH IT.
MORE SIGNIFICANT WARMING LIKELY EARLY IN THE EXTENDED PERIOD OVER
THE WEEKEND AS RIDGING MOVES INTO THE REGION AHEAD OF NEXT UPPER
WAVE COMING INTO THE PACIFIC NORTHWEST. ANOTHER COLD FRONT THEN
MOVES THROUGH ON MONDAY AS THE WAVE TRACKS EAST ACROSS THE PLAINS.
COLDEST AIR HOWEVER LOOKS TO STAY TO THE NORTH ALONG THE CANADIAN
BORDER AS UPPER FLOW BECOMES STRONGLY ZONAL...ESPECIALLY BY THE
ECMWF.
FOBERT
AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
NO SIGNIFICANT CHANGES FROM PREVIOUS FORECAST...ALTHOUGH DID
TWEAK THE TIMING OF THE ARRIVAL OF THE COLD FRONT TO 11Z AT
KOFK...13Z AT KLNK AND 14Z AT KOMA. LATEST RUC TRENDS WOULD
SUGGEST THAT IT MIGHT EVEN BE EVENHOUR BEYOND THAT. FEEL THAT
SCATTERED SNOW SHOWERS WILL DEVELOP AT BOTH KOFK/KOMA BEHIND THE
FRONT...ALTHOUGH NOT AS CONFIDENT THAT THEY WILL DEVELOP AT KLNK.
ALSO UNCERTAIN HOW LOW VISIBILITIES WILL DROP...GIVEN 25 TO 35 MPH
WINDS WITH HIGHER GUSTS. AM SEEING SEVERAL UPSTREAM REPORTS IN THE
3 MILE RANGE WITH SNOW...SO USED THAT AS A BEST ESTIMATE UNTIL THE
SNOW BAND GETS A LITTLE CLOSER
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
NEZ067-068-090>093.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ015-033-034-
043>045-050>053-065-066-078-088-089.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-012-016>018-
030>032-042.
IA...WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS EVENING FOR
IAZ055-056-069-079-080-090-091.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ043.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
601 AM CST WED JAN 11 2012
.AVIATION...
MAIN CONCERNS FOR THIS TAF CYCLE ARE STRONG WINDS AND MVFR CIGS.
COLD FRONT WILL MOVE THROUGH THE PANHANDLES THIS MORNING...WITH GUSTY
NORTHERLY WINDS IN ITS WAKE. THESE WINDS WILL INCREASE BETWEEN 14Z
AND 16Z...WITH 40 KNOTS POSSIBLE AT AMA INTO THE AFTERNOON. AWW WILL
CONTINUE AT AMA UNTIL 23Z. LATEST RUC FORECAST SOUNDINGS SHOW MVFR
CIGS HANGING AROUND UNTIL 00Z AND HAVE INCLUDED IN THE LATEST TAFS.
VFR CONDITIONS ANTICIPATED AFTER 00Z. NORTHERLY WINDS WILL ALSO
SUBSIDE BY 00Z...BUT GUST BETWEEN 20 AND 22 KNOTS UNTIL 06Z.
&&
.PREV DISCUSSION... /ISSUED 330 AM CST WED JAN 11 2012/
DISCUSSION...
COLD FRONT CURRENTLY THROUGH NORTHWESTERN KANSAS WILL MAKE ITS
PRESENCE KNOWN ACROSS PANHANDLES THIS MORNING. NORTH WINDS BEHIND
FRONT ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS. WIND CHILL
VALUES TODAY WILL REMAIN BELOW 32 DEGREES ACROSS ALL BUT FAR
SOUTHERN SECTIONS.
NO MEASURABLE PRECIPITATION IS EXPECTED TODAY...BUT HAVE INCLUDED
SCATTERED FLURRIES THIS AFTERNOON ACROSS NORTHERN SECTIONS...WHERE
POTENT VORTICITY MAXIMUM WILL TRAVERSE. NO PRECIPITATION IN
REMAINDER OF FORECAST.
WINDY CONDITIONS WILL END EARLY THIS EVENING...WITH CLEARING SKY
ALLOWING TEMPERATURES TO FALL INTO THE 10 TO 20 DEGREE RANGE AREA
WIDE. DEEP NORTHWEST FLOW ON THURSDAY WILL MAKE FOR ANOTHER COOL
DAY.
WARMING TREND BEGINS ON FRIDAY AS MID-LEVEL HEIGHTS RISE AND
SOUTHWEST SURFACE WINDS RESUME. WEAK COLD FRONT OR BRIEF WIND SHIFT
ON SATURDAY WILL HAVE MINIMAL IMPACT. DEEPENING SURFACE TROF SUNDAY
AND MONDAY EXPECTED TO RESULT IN MAXIMUM TEMPERATURES 10 TO 15
DEGREES ABOVE NORMAL. BACK DOOR COLD FRONT MONDAY NIGHT EXPECTED TO
PASS DRYLY...WITH COOLER CONDITIONS ON TUESDAY. 03
COCKRELL
FIRE WEATHER...
NORTH WINDS WILL DEVELOP THIS MORNING FOLLOWING THE PASSAGE OF A
STRONG COLD FRONT...BUT RELATIVE HUMIDITY VALUES WILL REMAIN WELL
ABOVE CRITICAL OR ELEVATED THRESHOLDS. NORTHWEST WINDS ON THURSDAY
WILL BE GUSTY MUCH OF THE DAY...AND THEN DIMINISH BY LATE
AFTERNOON. WINDS WILL BE MUCH LIGHTER FRIDAY AND SATURDAY.
SOUTHWEST WINDS INCREASE ON SUNDAY AND MONDAY...POSSIBLY RESULTING
IN ELEVATED FIRE WEATHER CONDTIONS ACROSS THE WESTERN HALF OF THE
FORECAST AREA. 03
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
10/03
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
300 PM CST WED JAN 11 2012
.SYNOPSIS...
12Z UA ANALYSIS HAD AN 850MB POLAR FRONT RUNNING FROM A LOW NEAR
THE MINNESOTA ARROWHEAD SOUTHWEST INTO NEW MEXICO. A CUT OFF LOW
WAS OVER THE TENNESSEE VALLEY DRIFTING TO THE NORTHEAST. SATELLITE
AND RADAR TRENDS THROUGH EARLY AFTERNOON SHOW CLOUDS MOVING EAST
ACROSS IOWA WITH A BAND OF SNOW FROM MINNESOTA INTO WESTERN IOWA
AND EASTERN NEBRASKA.
18Z SFC ANALYSIS HAD A SERIES OF LOW IN NORTHERN WISCONSIN WITH A
PRE-FRONTAL TROF THROUGH EASTERN IOWA AND INTO CENTRAL OKLAHOMA.
THE POLAR FRONT RAN FROM JUST EAST OF KDLH...TO KMCI...TO KCDS.
DEW POINTS ALONG THE FRONT WERE IN THE 30S WITH 20S OUT AHEAD OF
IT. BEHIND THE POLAR FRONT...DEW POINTS QUICKLY DROPPED OFF INTO
THE 20S AND TEENS.
&&
.SHORT TERM...TONIGHT AND THURSDAY
COMPRESSIONAL HEATING AHEAD OF THE POLAR FRONT HAS RESULTED IN
RECORD HIGHS BEING EITHER TIED OR BROKEN TODAY. SEE THE CLIMATE
SECTION BELOW FOR SPECIFIC RECORDS.
THE WINTER STORM WATCH HAS BEEN UPGRADED TO A WINTER WEATHER ADVISORY.
BASED ON THE SYSTEM BEING A BIT SLOWER AND DIGGING A LITTLE
FURTHER TO THE SOUTH/WEST...THE START TIME OF SOME ADVISORY
HEADLINES FOR AREAS ALONG/EAST OF THE MISSISSIPPI HAVE BEEN PUSHED
BACK TO MIDNIGHT.
THE POLAR FRONT SHOULD REACH THE BULK OF THE MISSISSIPPI RIVER
RIGHT AROUND SUNSET AND SHOULD EXIT THE EASTERN CWFA JUST BEFORE
MIDNIGHT. SINCE THE SYSTEM CONTINUES TO SHOW SOME NON-LINEARITY
ASPECTS TO IT...THE RUC HAS BE VERY USEFUL IN THE IMMEDIATE SHORT
TERM.
PER THE RUC...CONDENSATION PRESSURE DEFICITS START COLLAPSING THIS
EVENING IN THE FAR WESTERN CWFA AS THE FORCING INCREASES. BY 9
PM...A BAND OF SNOW WILL BE OVER ROUGHLY THE WESTERN THIRD TO 40
PERCENT OF THE CWFA. STARTING AROUND 9 PM...THE RUC INDICATES A
DEFORMATION ZONE WILL BEGIN DEVELOPING OVER EASTERN IOWA AS THE
UPPER LEVEL SYSTEM STRENGTHENS. BY MIDNIGHT...SNOW WILL BE WIDESPREAD
GENERALLY WEST OF A KDBQ TO KEOK LINE.
AFTER MIDNIGHT...THE OVERALL FORCING CONTINUES TO STRENGTHEN AS
THE DEFORMATION ZONE BECOMES FULLY EVOLVED. BY SUNRISE...SNOW
SHOULD BE WIDESPREAD ACROSS THE ENTIRE CWFA.
SNOWFALL AMOUNTS TONIGHT SHOULD RANGE FROM 0.5 INCHES IN THE
EXTREME EASTERN CWFA TO 2.5 INCHES IN THE FAR WESTERN CWFA.
SNOW/RAIN RATIOS WILL INITIALLY START OUT CLOSE TO
CLIMATOLOGY...OR ROUGHLY 13 TO 1 AND WILL INCREASE LATER TONIGHT
INTO THURSDAY.
BASED ON THE OVERALL FORCING...THE PERIOD FROM MIDNIGHT TO ABOUT NOON
THURSDAY WILL BE WHEN A MAJORITY OF THE SNOW WILL FALL.
ON THURSDAY...SNOW WILL BE WIDESPREAD ACROSS THE AREA DURING THE
MORNING HOURS WITH THE DEFORMATION ZONE OVER THE AREA. DURING THE
AFTERNOON THE SNOW INTENSITY WILL DECREASE ACROSS THE WESTERN CWFA
WHILE CONTINUING IN THE EASTERN PARTS.
SNOW AMOUNTS ON THURSDAY WILL BE AN ADDITIONAL 1 TO 4 INCHES WITH
A GRADIENT RUNNING FROM WEST TO EAST.
SINCE THE SNOW WILL BE QUITE DRY...CONSIDERABLE DRIFTING WILL BE
SEEN...ESPECIALLY IN RURAL AND OPEN AREAS. WINDS SHOULD BE 20 TO
30 MPH WITH GUSTS TO AROUND 35 MPH. WHILE BLOWING SNOW MAY
OCCUR...IT SHOULD BE PATCHY IN NATURE IN THE RURAL AREAS.
..08..
.LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY
ACTIVE PATTERN BUT NO SIGNIFICANT SYSTEMS SUGGESTED ATTM.
SNOW IS EXPECTED TO TAPER TO FLURRIES THU EVE WITH LITTLE ADDITIONAL
ACCUMS. LINGERING GUSTY WINDS MAY PRODUCE SOME DRIFTING AND POSSIBLY
PATCHY BLOWING SNOW.
FRI-FRI NGT... WINDS GENERALLY BRISK AT 10-20 MPH DURING DAY WITH
CLOUDS AND FLURRIES POSSIBLE WITH ADDITIONAL ENERGY DIGGING DOWN
BACKSIDE OF DEPARTING STORM SYSTEM. HIGHS ONLY RECOVERING IN TEENS
AND 20S. SOME CLEARING FRI NGT BUT APPEARS SHORT LIVED AS WARM
ADVECTION MID/HIGH CLOUDS QUICKLY ON HEELS OF ANY CLEARING ATTENDANT
TO NEXT APPROACHING SHORTWAVE /CLIPPER SYSTEM/. CLOUD TRENDS MAKE
MIN TEMP FCST CHALLENGING. ANTICIPATE WINDS TO DIE OFF IN EVE AND AT
LEAST PARTIAL CLEARING FOR WIDESPREAD SINGLE DIGITS... POSSIBLY AT
OR BELOW ZERO IN SOME AREAS N/E... BEFORE CLOUDS INCREASE.
SAT-SAT NGT... CLIPPER SYSTEM EXPECTED TO PASS MAINLY DURING DAY. JET
STRUCTURE NOT THAT IMPRESSIVE AND MOISTURE LACKING SO FAVOR THE
WEAKER HI-RES ECMWF FOR MAINLY FLURRIES WITH CHC OF -SN.
SUN-SUN NGT... GENERALLY DRY WITH MODERATING TEMPS AS HEIGHTS BUILD
ALOFT WITH CHALLENGE BEING RESIDUAL SNOW COVER AND IMPACT ON TEMPS.
MAY SEE NON-DIURNAL TREND AT NGT WITH TEMPS SLOWLY RISING WITH
CONTINUED LOW LEVEL WARM ADVECTION.
MON-WED... NEXT FRONT TO PASS MON-MON NGT WITH CHC OF PCPN. MODELS
SHOWING SUFFICIENT WARMING AHEAD FOR BULK OF PCPN TO BE RAIN BUT
AS COLDER AIR DEEPENS MON NGT IN WAKE OF FRONTAL PASSAGE COULD SEE
MIX OR BRIEF CHG TO -SN. TUE-WED LOOK TO BE MAINLY DRY AND COLDER.
..05..
&&
.AVIATION...
VFR WX WILL CONTINUE UP UNTIL ROUGHLY 00Z/12. BTWN 00Z/12 AND
06Z/12 MVFR CIGS WL DLVP AT ALL TAF SITES WITH SN DVLPG IN THE
03Z/12 TO 07Z/12 TIME FRAME. CONDITIONS WILL DETERIORATE RAPIDLY
FROM 05Z/12 TO 10Z/12 WITH POTENTIAL IFR CONDITIONS. INCREASING
WINDS AND LOWERING CIGS MAY RESULT IN BRIEF PERIODS OF LIFR
CONDITIONS AFT 09Z/12.
..08..
&&
.CLIMATE...
RECORD HIGHS FOR JANUARY 11...
RECORD HIGHS WERE TIED OR BROKEN TODAY
MOLINE.........56 IN 1880
CEDAR RAPIDS...51 IN 2002 AND OTHER YEARS
DUBUQUE........50 IN 1980
BURLINGTON.....55 IN 1980
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST FRIDAY
FOR CLINTON-JACKSON-SCOTT.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT CST
THURSDAY NIGHT FOR BENTON-BUCHANAN-CEDAR-DELAWARE-DES
MOINES-DUBUQUE-HENRY IA-IOWA-JEFFERSON-JOHNSON-JONES-KEOKUK-
LEE-LINN-LOUISA-MUSCATINE-VAN BUREN-WASHINGTON.
IL...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST FRIDAY
FOR BUREAU-CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-
MCDONOUGH-MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-
WHITESIDE.
MO...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT CST
THURSDAY NIGHT FOR CLARK-SCOTLAND.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
203 PM CST WED JAN 11 2012
.SYNOPSIS...
12Z RAOB PLOT ANALYSIS INDICATES A LARGE TROUGH PUSHING ACROSS THE ROCKIES
AND INTO THE NORTHERN PLAINS. THIS FEATURE HAS USHERED IN A COLD FRONT
EARLY THIS MORNING ACROSS SOUTHWEST KANSAS. AS OF 18Z, THIS FRONT IS
STILL MOVING ACROSS OKLAHOMA. WINDS WERE STRONG BEHIND THE FRONT WITH
MANY OBSERVATION SITES ACROSS WESTERN KANSAS REPORTING WINDS AROUND
30 KT.
&&
.DISCUSSION...
DAYS 1-2...
TONIGHT:
SHORT TERM FOCUS IS WINDS. HAVE UPDATED THE WIND ADVISORY FOR THE ENTIRE
REGION AS AWOS SITES ACROSS FAR WESTERN KANSAS HAVE BEEN AT WIND ADVISORY
CRITERIA EARLIER. HRRR AND NAM SHOW THAT WINDS WILL QUICKLY TAPER TOWARDS
6 PM CST. SECOND SHORT TERM FOCUS IS IF WE WILL SEE PRECIPITATION. THE
NAM HAS VERY LIGHT QPF ACROSS CENTRAL KANSAS TONIGHT. HRRR ALSO INDICATES
LIGHT COMPOSITE REFLECTIVITY FORECAST SO HAVE PUT 20 POPS ACROSS THE
NORTHEAST/NORTH. ELSEWHERE, WILL KEEP AROUND 10 PERCENT WITH FLURRIES. THIS
ACTIVITY WILL DIMINISH THIS EVENING. OVERNIGHT LOWS WILL BE ON THE COLD
SIDE AS WINDS WEAKEN AND SKIES CLEAR. WINDS WILL NOT COMPLETELY CALM
SO DID NOT GET TOO CARRIED AWAY WITH LOWS.
THURSDAY/THURSDAY NIGHT:
ANOTHER WINDY DAY LOOKS LIKELY ACROSS SOUTHWEST KANSAS TOMORROW. THIS
IS IN ASSOCIATION WITH A TIGHT PRESSURE GRADIENT REMAINING OVER THE
AREA. HAVE INCREASED WINDS IN THE GRIDS IN THE 20 TO 30 MPH RANGE BUT
KEPT VALUES/GUSTS BELOW WIND ADVISORY CRITERIA. INSTEAD OF HAVING TWO
WIND ADVISORIES OUT, WHICH COULD BE CONFUSING...I WILL LET THE MID SHIFT
DECIDE IF WE NEED A WIND ADVISORY OR NOT. TOMORROWS HIGHS WILL BE IN
THE 30S DEG F. OVERNIGHT LOWS ARE EXPECTED TO BE IN THE TEENS DEG F.
FRIDAY:
KANSAS WILL BE IN NORTHWEST FLOW ALOFT WHICH FAVORS A DRY FORECAST.
WILL KEEP POPS AT ZERO FRIDAY. COULD SEE SOME DOWNSLOPE WESTERLY WINDS
FRIDAY SO HAVE WARMED HIGHS UP A BIT. 850 HPA TEMPERATURES WARM UP INTO
THE LOWER SINGLE POSITIVE DIGITS DEG C, SO WE COULD SEE SOME MIXING
TO 40S DEG F AT THE SURFACE.
DAYS 3-7...
THE MID TO UPPER-LEVEL FLOW WILL GRADUALLY TRANSITION FROM
NORTHWESTERLY TO WEST-SOUTHWESTERLY FROM FRIDAY NIGHT INTO SUNDAY.
THUS, SURFACE PRESSURES WILL FALL IN THE LEE OF THE ROCKIES ALONG
WITH SOME WEAK LOW-LEVEL DOWNSLOPE FLOW. HIGH TEMPERATURES WILL
MODIFY INTO THE MID 50S BY SATURDAY AND 55 TO 60 BY SUNDAY.
A SHORTWAVE TROUGH WILL PROGRESS IN MAINLY ZONAL FLOW ACROSS THE
CENTRAL AND NORTHERN PLAINS BY MONDAY AND MONDAY NIGHT. THIS WILL
BRING SOME COLDER AIR INTO WESTERN KANSAS. SO AFTER A FAIRLY MILD
DAY MONDAY (50S TO LOWER 60S) JUST IN ADVANCE OF THE FRONT, HIGHS
WILL FALL INTO THE 30S OR LOWER 40S BY TUESDAY. NO PRECIPITATION CAN
BE EXPECTED IN THIS ZONAL PATTERN.
ANOTHER WARMING TREND IS EXPECTED BY JANUARY 18-19TH WITH HIGHS
POSSIBLY REACHING TO NEAR 70F IN A GENERALLY ZONAL MID TO UPPER-LEVEL
FLOW REGIME WITH LEE-TROUGHING AT LOW-LEVELS. HOWEVER, AS IS OFTEN
THE CASE IN ZONAL REGIMES, THERE WILL BE A SHARP TEMPERATURE
GRADIENT BETWEEN DOWNSLOPE FLOW OVER THE SOUTHERN AND CENTRAL PLAINS
AND ARCTIC AIR OVER THE NORTHERN PLAINS OR SOUTHERN CANADA. ANY
SHORTWAVE TROUGH TRAVERSING THE FLOW COULD RESULT IN ANOTHER SURGE
OF COLD AIR. THE ECMWF IS ADVERTISING ANOTHER SUCH COOLDOWN BY
JANUARY 20-21ST. NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH
JANUARY 21ST.
&&
.AVIATION...
FOR THE 18Z TAF ISSUANCE...
WINDS WILL REMAIN SUSTAINED AT 30 KTS WITH GUSTS TO 40 KTS THOUGH
23Z AS STRONG VERTICAL MIXING BRINGS DOWN THE HIGHER WINDS. BY 00Z
THE WINDS WILL SUBSIDE TO 15TS AS THE PRESSURE GRADIENT AND VERTICAL
MIXING WEAKEN. SKIES WILL VARY BETWEEN SCT/BKN025 AND THEN CLEAR BY
00Z. A FEW FLURRIES ARE POSSIBLE AT KHYS JUST AHEAD OF AN
UPPER-LEVEL TROUGH THROUGH 23Z, BUT THIS SHOULD NOT BE ENOUGH TO
REDUCE VISIBILITIES BELOW 5SM.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 12 35 14 46 / 10 0 0 0
GCK 11 35 12 47 / 10 0 0 0
EHA 11 37 15 48 / 10 0 0 0
LBL 11 36 15 48 / 10 0 0 0
HYS 11 33 11 46 / 10 0 0 0
P28 17 37 15 46 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR KSZ030-
031-043>046-061>066-074>081-084>090.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1028 AM CST WED JAN 11 2012
.UPDATE...ONLY CHANGE THIS MORNING WAS TO LOWER AFTERNOON HIGHS IN
CONCERT WITH THE COOLER NAM GUIDANCE...ESPECIALLY ACROSS AREAS ALONG
AND NORTHEAST OF THE HWY 49 CORRIDOR WHERE THE LOW CLOUDS WILL BE
MOST STUBBORN THROUGH THE DAY. LATEST RUC GUIDANCE SUGGESTS THE
CLOUDS MAY TRY TO BREAK UPPER FURTHER WEST/SOUTH LATER THIS AFTERNOON
WHICH MAY ALLOW TEMPS TO RISE INTO THE MID 50S TO NEAR 60 IN A FEW
SPOTS. REST OF THE FORECAST LOOKS TO BE IN GOOD SHAPE...UPDATED
AVIATION DISCUSSION APPENDED BELOW. /BK/
&&
.PREV DISCUSSION... /ISSUED 343 AM CST WED JAN 11 2012/
DISCUSSION...TODAY THROUGH THURSDAY NIGHT...WHILE THE SURFACE LOW
AND COLD FRONT HAVE ALL BUT CLEARED THE CWA THIS MORNING...SATELLITE
SHOWS A VIGOROUS UPPER LOW LIFTING NORTHEAST DIRECTLY OVER THE
FORECAST AREA. THIS UPPER LOW WILL BE RESPONSIBLE FOR PRODUCING
SOME PATCHY OF DRIZZLE...AND EVEN SOME LIGHT RAIN...THROUGH THE
MORNING AND INTO THE EARLY AFTERNOON. LOW CLOUDS WILL ALSO PLAGUE
MUCH OF THE AREA TODAY...ESPECIALLY NORTHEAST MISSISSIPPI...BUT SOME
BREAKS WILL LIKELY BEE SEEN ACROSS THE WESTERN HALF OF THE CWA
DURING THE AFTERNOON. TEMPERATURES THIS AFTERNOON WILL STRUGGLE TO
GET OUT OF THE 50S IN MOST LOCATIONS...WITH LOWER 60S POSSIBLE
ACROSS THE SOUTH.
CLOUDS WILL TRY TO CLEAR OUT TONIGHT BUT TO NO AVAIL. ANOTHER...
STRONGER BUT MAINLY DRY...COLD FRONT WILL RACE IN FROM THE NORTHWEST
AND THROUGH THE CWA OVERNIGHT AND INTO EARLY THURSDAY MORNING.
OTHER THAN A FEW SPRINKLES OVER THE NORTH...NOT MUCH IN THE WAY OF
PRECIPITATION IS EXPECTED WITH THIS FRONT AS IT PUSHES THROUGH.
NOTICEABLY COLDER DRIER AIR THOUGH WILL BEGIN TO SURGE INTO THE CWA
FROM THE NORTHWEST AS TEMPERATURES RANGE FROM THE MID 30S TO MID 40S
EARLY THURSDAY MORNING.
STRONG COLD ADVECTION WILL BE ONGOING ACROSS THE REGION THROUGH THE
DAY THURSDAY WITH MUCH COLDER DRIER CONDITIONS EXPECTED. HIGHS
THURSDAY WILL STRUGGLE TO CLIMB OUT OF THE 40S WITH A STRONG
NORTHWEST WIND EXPECTED DURING THE DAY. WITH A TIGHT PRESSURE
GRADIENT OVER THE REGION...WINDS RIGHT NOW ON THURSDAY WILL LIKELY
BE SUSTAINED BETWEEN 20-25 MPH...WITH GUSTS AT OR GREATER THAN 30
MPH POSSIBLE. IF IT APPEARS WINDS COULD BE STRONGER...A WIND
ADVISORY MAY BE NEEDED FOR AT LEAST PORTIONS OF THE CWA THURSDAY.
WINDS WILL RELAX AS SKIES BECOME MOSTLY CLEAR EARLY THURSDAY
NIGHT...THUS CAUSING THE MERCURY TO RAPIDLY FALL. RIGHT NOW I`LL
STICK WITH MAV GUIDANCE WHICH SUGGESTS LOWS IN THE LOWER 20S FOR
EARLY FRIDAY MORNING. HOWEVER...AFTER MIDNIGHT AND TOWARDS DAY
BREAK...SOME HIGH CLOUDS COULD BEGIN TO SPREAD EAST AND OVER THE
AREA. IF THIS HAPPENS...LOWS FRIDAY MORNING COULD BE A COUPLE OF
DEGREES WARMER THAN CURRENTLY FORECAST...BUT STILL IN 20S. /19/
FRIDAY THROUGH NEXT WEDNESDAY...THE MED RANGE/LONG TERM WILL OFFER
TWO PATTERNS WITH HIGHER THAN USUAL CONFIDENCE BASE OFF NUMERICAL
MODELS BEING IS SOLID AGREEMENT. THE FIRST HALF OF THE EXTENDED WILL
FEATURE COLDER TEMPS WHILE THE LATTER HALF WILL TRANSITION TO A
WETTER PERIOD.
FOR FRI...THE CENTER OF THE COLD CANADIAN AIRMASS WILL BE SHIFTING
OVER THE CWA WITH VERY DRY AIR IN PLACE. AFTER A COLD START TO THE
DAY...HIGH TEMPS WILL REBOUND A BIT...BUT REMAIN 6-10 DEGREES BELOW
AVG. MID/UPPER 40S WILL SHOULD BE EXPECTED WHICH IS A COUPLE DEGREES
LOWER THAN THE GFS GUID. SFC HIGH PRESSURE WILL REMAIN OVER THE CWA
FOR FRI NGT AND OFFER ANOTHER COLD NGT. MY INITIAL THOUGHT WAS TO
CUT LOWS SOME...BUT ALL THE MODELS INDICATE SOME UPPER LEVEL CLOUDS
MOVING BY AND THAT MAY JUST BE ENOUGH TO PREVENT PERFECT RAD COOLING
CONDITIONS.
BY SAT...THE SFC HIGH BEGINS TO SHIFT AWAY FROM THE CWA AND SLIGHT
RETURN FLOW WILL TAKE PLACE ALLOWING FOR MODERATING CONDITIONS.
AGAIN...THE PRESENCE OF SOME HIGH CLOUDS EARLY AND COLD START TO THE
DAY...FEEL THE GFS IS WARMING THINGS TOO QUICKLY. AS A RESULT...HAVE
FOLLOWED THE ENSEMBLE SOLUTION FOR HIGHS...MID 50S. SUNDAY WILL BE
THE DAY OF TRANSITION...LOOK FOR A COOL START TO THE DAY AND A
BETTER WARMUP FOR AFTERNOON.
BETTER RETURN FLOW WILL TAKE SHAPE FOR MON AS A STRONG GRADIENT
DEVELOPS IN RESPONSE TO THE NEXT SYSTEM AND SFC FRONT. INCREASING
PRECIP CHANCES WILL DEVELOP FOR MON ACROSS THE NW...THEN SPREAD OVER
THE ENTIRE AREA FOR MON NGT INTO TUE. GUID WAS OFFERING 40% POPS
DURING THIS TIME AND THAT SEEMS REASONABLE GIVEN ITS DAY 5/6. FOR
NOW...ONLY WILL MENTION SHOWERS...BUT SOME THUNDER MAY HAVE TO BE
ADDED IF THE MODELS CAN AGREE ON BETTER LAPSE RATES. /CME/
&&
.AVIATION...
LOWS CLOUDS AND PATCHY DRIZZLE WILL KEEP CEILINGS IN THE MVFR/IFR
RANGE THROUGH A GOOD BIT OF THE DAY...WITH LOW CLOUDS HANGING AROUND
INTO TONIGHT. WEST TO WEST SOUTHWEST SURFACE WINDS BETWEEN 10-15 MPH
ARE EXPECTED TODAY...BUT WILL BECOME GUSTY FROM THE NORTHWESTERLY
LATE TONIGHT INTO THURSDAY MORNING AS ANOTHER STRONG COLD FRONT MOVES
THROUGH. ANY SITE THAT SEES VFR CONDITIONS OVER THE NEXT 24 HOURS
WILL BE BRIEF. /28/19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 53 39 45 23 / 4 9 10 0
MERIDIAN 53 39 47 23 / 6 10 11 0
VICKSBURG 55 38 44 22 / 2 11 9 0
HATTIESBURG 61 44 50 22 / 7 14 10 0
NATCHEZ 56 39 43 23 / 1 8 7 0
GREENVILLE 53 36 42 23 / 5 16 11 0
GREENWOOD 53 38 43 22 / 11 12 12 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BK/28
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1140 AM CST WED JAN 11 2012
.AVIATION...18Z TAFS FOR KOFK...KOMA AND KLNK.
A STRONG COLD FRONT HAS MOVED THRU THE TAF SITES LEAVING STRONG
AND GUSTY NORTHWEST SFC WINDS BEHIND IT. SFC WINDS SUSTAINED
AROUND 25 TO 30 KTS WITH GUSTS UP TO 40 TO 45 KTS WILL CONTINUE
THROUGH THE AFTERNOON AND ONLY WEAKEN SLIGHTLY AFTER 00Z. A BAND
OF SNOW SHOWERS WILL CONTINUE TO PASS OVER THE SITES FROM
NORTHWEST TO SOUTHEAST. VISIBILITIES WILL COME DOWN TO NEAR IFR
CONDITIONS BUT SNOWFALL IS EXPECTED TO REMAIN LIGHT WITH UNDER A
HALF INCH OF ACCUMULATION. BLOWING DUST IS OCCURRING AT KOMA AND
WILL LIKELY CONTINUE THROUGH THE AFTERNOON. THIS IS MOST LIKELY
FROM SEDIMENT BEING STIRRED UP AND BLOWN AROUND FROM LAST SUMMERS
MISSOURI RIVER FLOOD. CEILINGS ARE EXPECTED TO REMAIN IN THE MVFR
CATEGORY THROUGH THE TAF PERIOD.
LIGHT FLURRIES ARE POSSIBLE AGAIN OVERNIGHT AS A SECONDARY
DISTURBANCE ROTATES THRU THE AREA.
KERN
&&
.PREV DISCUSSION... /ISSUED 516 AM CST WED JAN 11 2012/
AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
A STRONG COLD FRONT THAT PUSHED THROUGH KOFK BEFORE TAF ISSUANCE
WILL QUICKLY MOVE ACROSS KOMA/KLNK WITH SURFACE WINDS EASILY
GUSTING OVER 30KTS. LOW CLOUDS IN THE LOW MVFR CATEGORY...POSSIBLY
IFR CATEGORY AT KOFK...WILL MOVE IN AN HOUR OR TWO AFTER FRONT
PASSES. IN ADDITION...SNOW SHOWERS THAT ARE LIKELY LATER THIS
MORNING MORNING THROUGH THIS AFTERNOON COULD REDUCE VISIBILITIES
DOWN TO 3 OR 4 MILES. ALTHOUGH THERE WAS SOME INDICATION THE
INTENSITY WOULD WEAKEN COMPARED TO UPSTREAM CONDITIONS WHERE SOME
VISIBILITIES DROPPED BELOW 1 MILE...CONFIDENCE NOT HIGH. LOW
CEILINGS AND ADDITIONAL SNOW SHOWERS/FLURRIES LIKELY LATER TONIGHT
AS SECOND DISTURBANCE MOVES ACROSS THE REGION.
CHERMOK
PREV DISCUSSION... /ISSUED 245 AM CST WED JAN 11 2012/
DISCUSSION...
COLD FRONT JUST BEGINNING TO ENTER NORTHWEST PORTION OF THE CWA AT
08Z WITH WIND SHIFT AT KBVN AND KYKN. COLDER AIR AND BAND OF
PRECIP LAGS BEHIND THE BOUNDARY HOWEVER WITH INITIAL WINDS
BOOSTING TEMPERATURES INTO THE LOWER 40S IMMEDIATELY BEHIND THE
BOUNDARY. 05Z HRRR MODEL HAS FRONT THROUGH MOST OF THE CWA BY 15Z
WITH THE COLDER AIR AND PRECIP JUST COMING INTO NORTHEAST
NEBRASKA AT THAT TIME. WINDS INCREASE ACROSS THE REMAINDER OF THE
CWA THEREAFTER...HAVE ADDED EASTERN PARTS OF THE CWA FROM
SOUTHEAST NEBRASKA INTO SOUTHWEST IOWA TO WIND ADVISORY AFTER 18Z.
A MIX OF RAIN AND SNOW SHOWERS POSSIBLE INITIALLY BEFORE CHANGING
TO ALL SNOW AS COLDER AIR MOVES IN. ONLY MINOR SNOWFALL EXPECTED
SINCE WIDTH OF PRECIP BAND FAIRLY NARROW AND SYSTEM MOVING THROUGH
QUICKLY. ANY REMAINING SNOW SHOWERS OR FLURRIES EXPECTED TO END
EARLY THIS EVENING IN THE FAR SOUTHEAST CORNER OF THE CWA.
TEMPERATURES...WIND AND SKY CONDITION THEN BECOME THE MAIN FOCUS
FOR TONIGHT INTO THURSDAY NIGHT AS UPPER LOW GRADUALLY SHIFTS
EAST. SLIGHTLY WARMER TEMPERATURES RETURN ON FRIDAY BUT ANY
WARMING LOOKS TO BE SHORT LIVED AS NEXT CLIPPER DROPPING INTO
NORTHERN MINNESOTA BY SATURDAY MORNING ALSO PULLS DOWN ANOTHER
BATCH OF COLD AIR WITH IT.
MORE SIGNIFICANT WARMING LIKELY EARLY IN THE EXTENDED PERIOD OVER
THE WEEKEND AS RIDGING MOVES INTO THE REGION AHEAD OF NEXT UPPER
WAVE COMING INTO THE PACIFIC NORTHWEST. ANOTHER COLD FRONT THEN
MOVES THROUGH ON MONDAY AS THE WAVE TRACKS EAST ACROSS THE PLAINS.
COLDEST AIR HOWEVER LOOKS TO STAY TO THE NORTH ALONG THE CANADIAN
BORDER AS UPPER FLOW BECOMES STRONGLY ZONAL...ESPECIALLY BY THE
ECMWF.
FOBERT
AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
NO SIGNIFICANT CHANGES FROM PREVIOUS FORECAST...ALTHOUGH DID
TWEAK THE TIMING OF THE ARRIVAL OF THE COLD FRONT TO 11Z AT
KOFK...13Z AT KLNK AND 14Z AT KOMA. LATEST RUC TRENDS WOULD
SUGGEST THAT IT MIGHT EVEN BE EVENHOUR BEYOND THAT. FEEL THAT
SCATTERED SNOW SHOWERS WILL DEVELOP AT BOTH KOFK/KOMA BEHIND THE
FRONT...ALTHOUGH NOT AS CONFIDENT THAT THEY WILL DEVELOP AT KLNK.
ALSO UNCERTAIN HOW LOW VISIBILITIES WILL DROP...GIVEN 25 TO 35 MPH
WINDS WITH HIGHER GUSTS. AM SEEING SEVERAL UPSTREAM REPORTS IN THE
3 MILE RANGE WITH SNOW...SO USED THAT AS A BEST ESTIMATE UNTIL THE
SNOW BAND GETS A LITTLE CLOSER
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ067-068-090>093.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-012-015>018-
030>034-042>045-050>053-065-066-078-088-089.
IA...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ055-056-069-079-
080-090-091.
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ043.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
310 PM EST WED JAN 11 2012
.SYNOPSIS...
A STRONG UPPER LEVEL STORM SYSTEM WILL MOVE ACROSS THE INLAND
CAROLINAS TODAY BRINGING WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS. A WEAK COLD FRONT WILL FOLLOW THIS SYSTEM THIS
EVENING. A DEEP UPPER STORM SYSTEM FORMING OVER THE PLAINS WILL
PREVENT SIGNIFICANTLY COLD AIR FROM MOVING IN THURSDAY. A STRONG
COLD FRONT WILL DRIVE THROUGH THE CAROLINAS LATE THURSDAY BRINGING
A COLDER AND DRY WEEKEND. HIGH PRESSURE WILL MOVE OFF THE COAST
EARLY NEXT WEEK WITH TEMPERATURES RETURNING TO NORMAL.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...WARM FRONT HAS MOVED TO A POSITION FROM
HVS TO BBP TO LBT TO EYF TO BACK ISLAND AND WILL MOVE N OF ALL
FORECAST POINTS BY 1930Z. DEWPOINTS HAVE RISEN INTO THE UPPER 50S
AND LOWER 60S IN THE WARM SECTOR. A VERY DYNAMIC SYSTEM WILL
AFFECT THE AREA LATE THIS AFTERNOON AND EVE. THE MAIN SURFACE LOW
WILL TRACK ALONG THE OHIO VALLEY THROUGH TONIGHT. A POTENT
SHORTWAVE ROTATING AROUND THE UPPER LOW WILL HELP TO DEVELOP A
SECONDARY AREA OF LOW PRESSURE WHICH WILL MOVE NE AND ACROSS THE
CAROLINA PIEDMONT THIS EVE. IN THE NARROW WEDGE BETWEEN THE WARM
FRONT TO N AND COLD FRONT TO W... THE AIRMASS WILL BE SLIGHTLY
UNSTABLE AND SHEAR WILL INCREASE... ESPECIALLY IN THE VICINITY OF
THE SECONDARY LOW AND WARM FRONT. AT THIS TIME...THE HIGHEST RISK
FOR ANY SEVERE WEATHER WOULD BE N AND NE OF THE FORECAST AREA
WHERE BETTER SHEAR AND INSTABILITY ALIGN. ONGOING CONVECTION
SHOULD LARGELY LIFT OUT THROUGH MID AFTERNOON. THEN A LINE OF
FORCED SHOWERS AND ISOLATED THUNDERSTORMS IS EXPECTED LATE
AFTERNOON AND EVE IMMEDIATELY AHEAD OF THE FRONT... FROM W TO E.
THE ACTUAL COLD FRONT WILL CLEAR THE COAST IN THE 02-04Z TIME
FRAME. LOW LEVEL JET OF 50 TO 60 KT WILL PEAK DURING THIS TIME
FRAME. THE LACK OF SIGNIFICANT SURFACE BASED INSTABILITY MAY MAKE
IT DIFFICULT FOR THESE HIGHER WINDS TO MIX TO THE SURFACE.
HOWEVER...STRONG GUSTY WINDS SHOULD BE ABLE TO MIX TO THE SURFACE
IN THE STRONGEST/DEEPEST CONVECTION GIVEN THAT DOWNDRAFT CAPE
VALUES ARE EXPECTED TO BE ABOVE 700 J/KG. MUCH NEEDED RAINFALL HAS
ALREADY FALLEN ACROSS A GOOD CHUNK OF THE AREA WITH A FEW SPOTS
REPORTING ABOUT A HALF INCH. TOTAL RAINFALL AMOUNTS IN THE ONE-
HALF TO ONE INCH RANGE ARE COMMONLY EXPECTED BEFORE THE PUNCH OF
DRY AIR REACHES THE AREA LATER THIS EVE. HIGHEST AMOUNTS WILL
LIKELY OCCUR NEAREST TO THE COAST.
DRIER AND SLIGHTLY COOLER AIR WILL PUNCH IN BEHIND THE COLD FRONT
TONIGHT AND SKIES WILL AT LEAST PARTIALLY CLEAR. EVE TEMPS WILL NOT
CHANGE MUCH AHEAD OF THE COLD FRONT. LOWS EARLY THU MORNING SHOULD
BE IN THE MID AND UPPER 40S WITH PERHAPS A FEW LOWER 50S HANGING ON
AT THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...POTENT LOW PRESSURE SYSTEM WILL BE LIFTING
OFF TO THE NORTH INTO NEW ENGLAND AS COLD FRONT MOVES OFF TO THE
NORTHEAST ON THURS. AS THIS ONE SYSTEMS MOVES OFF TO THE NORTHEAST
ANOTHER NORTHERN STREAM MID TO UPPER LOW WILL DIG DOWN INTO THE
SOUTHERN MISSISSIPPI VALLEY FROM THE GREAT LAKES. THIS WILL
MAINTAIN A DEEPER SOUTHWEST FLOW OUT AHEAD OF IT THROUGH THURS
WITH DRIER AIR WRAPPING AROUND INTO THE AREA IN STRONGER WINDS
ALOFT. PCP WATER VALUES DROP DOWN CLOSER TO A HALF INCH THROUGH
THE DAY. WILL MAINTAIN A WARMER FLOW WITH TEMPS REMAINING UP IN
THE 60S ON THURS.
BY THURS NIGHT AN ARCTIC FRONT WILL GET PUSHED THROUGH BY MID TO
UPPER TROUGH DIGGING DOWN INTO THE SOUTHEAST AS IT TRACKS EAST. LOW
LEVEL WINDS AHEAD OF THIS FRONT WILL BE UP NEAR 45 TO 50 KTS
HELPING TO PUSH MOIST GULF AND ATLANTIC AIR INTO THE COASTAL
CAROLINAS AHEAD OF THE FRONT THURS NIGHT. THIS WILL PRODUCE A
SPIKE IN PCP WATER UP NEAR AN INCH FOR A FEW HOURS. THE MAIN
ENERGY WITH THIS SYSTEM WILL REMAIN WEST OF LOCAL AREA BUT
NAM/GFS SHOWING A PIECE OF ENERGY RIDING AROUND THE MAIN TROUGH
RIGHT THROUGH ILM CWA SHORTLY AFTER MIDNIGHT AS FRONT MOVES
THROUGH. ADDED MORE CLOUDS TO FORECAST AND EXPECT WE MAY SEE A FEW
LIGHT AND SPOTTY SHOWERS AS THIS SYSTEM PUSHES THROUGH AND WILL
ADD A SLIGHT CHC FOR OVERNIGHT THURS.
ONCE THIS FRONT CLEARS THE AREA AND MID TO UPPER LOW LIFTS OFF ON
FRI...PLENTY OF DRY AND COOL AIR WILL MOVE IN AS HIGH PRESSURE
BUILDS IN FROM THE WEST. 850 TEMPS PLUMMET FROM AROUND 6 C THURS
NIGHT DOWN TO -4 C BY FRI MORNING. ALTHOUGH THE 850 TEMPS RECOVER
SLIGHTLY IN WESTERLY FLOW FRI AFTN...THE VALUES REMAIN BASICALLY
BELOW 0C THROUGH THE REMAINDER OF THE SHORT TERM INTO THE WEEKEND.
TEMPS WILL HAVE TROUBLE MAKING IT TO 50 ON FRI IN A COLD AND DRY
AIR MASS WITH PLENTY OF SUNSHINE. OVERNIGHT LOWS FRI NIGHT WILL
DROP BELOW FREEZING IN MOST PLACES IN CAA.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 300 PM WEDNESDAY...AMPLIFIED UPPER TROUGH CONTINUES ACROSS THE
EAST THROUGH MONDAY WITH WEAK UPPER IMPULSES ROTATING AROUND THE
BASE OF THE TROUGH. THESE IMPULSES PROVIDE REINFORCING SHOTS OF COLD
AIR EARLY SATURDAY AND A STRONGER ONE LATE SUNDAY AS ARCTIC HIGH
PRESSURE RIDGES DOWN FROM THE NORTH. HOWEVER...VERY DRY AIR AS
EVIDENCED BY PWATS LESS THAN ONE-HALF INCH WILL KEEP THE FORECAST
DRY WITH JUST BOUTS OF INCREASED CLOUD COVER. TEMPS WILL REMAIN
BELOW NORMAL...AROUND 50 SATURDAY AND MONDAY WITH MODERATE CAA...BUT
WARMING INTO THE LOWER TO MID 50S SUNDAY AS WINDS BRIEFLY BECOME SW.
MINS IN THE 20S EACH DAY...WITH MONDAY LIKELY BEING THE COLDEST
MORNING DUE TO BETTER RADIATIONAL COOLING.
BEYOND MONDAY...GUIDANCE AGREES THAT UPPER RIDGING WILL DEVELOP IN
RESPONSE TO HEIGHT FALLS ACROSS THE MIDDLE OF THE COUNTRY WHICH
RETURNS THE AREA TO ABOVE NORMAL TEMPERATURES BY TUESDAY.
THEREAFTER...MODELS DIVERGE IN EVOLUTION OF LEE-CYCLOGENESIS EAST OF
THE ROCKIES AND HOW THIS WILL IMPACT THE CAROLINAS. WILL FAVOR THE
ECMWF FOR CONSISTENCY WHICH HAS A MORE PROGRESSIVE SOLUTION...BUT
BOTH GFS/EURO DEPICT A COLD FRONT TRAILING THROUGH LATE TUE/EARLY
WED. MOISTURE RETURN ONCE AGAIN LOOKS LIMITED THIS FAR OUT. HAVE
BUMPED POP HIGHER...BUT STILL LOW ENOUGH TO KEEP THE EXTENDED DRY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...THE HRRR MODEL WAS LEANED ON HEAVILY FOR THE FIRST SIX
HOURS OF TAF TIME. IT HAS BEEN FAIRLY CONSISTENT WITH A GOOD
CONVERGENCE BOUNDARY ALONG THE COAST. BEST CHANCE FOR GUSTY WINDS
AND HEAVY PRECIP WILL BE AT ILM...SECONDARILY THE MYRTLES. INLAND
TERMINALS WILL STILL SEE CONVECTION...JUST WITH LIGHTER PRECIP. LOOK
FOR INTERMITTENT IFR VISIBILITIES AT ILM IN THE HEAVIER SHOWERS.
COLD FRONT WILL APPROACH FROM THE WEST AFTER 02Z...WITH THE BOUNDARY
EXPECTED TO EXIT THE COAST BY 03-04Z. BEHIND THE FRONT...EXPECT
IMPROVING CONDITIONS WITH A WIND SHIFT TO THE WEST SOUTHWEST.
MODERATE MIXING AND COLD AIR ADVECTION WILL KEEP WINDS GUSTY FOR
MUCH OF THE NIGHT...DIMINISHING A BIT AFTER 08Z.
THURSDAY...VFR WITH SCATTERED SKIES AND CONTINUED WEST SOUTHWEST
FLOW...GUSTY AT TIMES.
EXTENDED OUTLOOK...VFR IS EXPECTED THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...SMALL CRAFT ADVISORY WILL REMAIN IN PLACE
INTO THU AFTERNOON. WINDS AND SEAS HAVE BEGUN TO INCREASE AS STRONG
COLD FRONT APPROACHES THE WATERS. THIS FRONT WILL MOVE ACROSS THE
WATERS 03-05Z TIME FRAME. WINDS WILL BE FROM THE S AHEAD OF THE
FRONT AND THEN VEER TO SW. STRONGEST WINDS WILL OCCUR THROUGH THIS
EVE...PEAKING RIGHT AHEAD OF THE FRONT AND THEN TRENDING LOWER
OVERNIGHT. SUSTAINED WINDS AS HIGH AS 25 KT MAY GUST FOR A TIME TO
AROUND 30 KT THIS EVE WITH EVEN HIGHER GUSTS IN THE VICINITY OF
STRONG CONVECTION. THE COOLER SHELF WATERS SHOULD HELP TO DAMPEN THE
STRONGEST OF WINDS AND MARINERS SHOULD BE AWARE THAT EVEN STRONGER
WINDS WILL OCCUR OFFSHORE WHERE WARMER SEA SURFACE TEMPS RESIDE.
SEAS WILL PEAK THIS EVE...IN THE 5 TO 8 FT RANGE...THEN SLOWLY
SUBSIDE AFTER MIDNIGHT. SEAS COULD REACH NEAR 10 FT OUT AROUND
FRYING PAN SHOALS BUOY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...AS ONE SYSTEM MOVES OFF TO THE NORTH
ANOTHER MID TO UPPER LOW WILL DIG DOWN MAINTAINING SOUTHWEST WINDS
THROUGH THURS. A TIGHTENED GRADIENT WILL PERSIST BETWEEN THESE
SYSTEMS AND HIGH PRESSURE BUILDING IN THROUGH THE MID WEST. EXPECT
WINDS TO MAINTAIN AROUND 20 KTS THURS. SW WINDS WILL INCREASE
FURTHER UP CLOSE TO 30 KTS AS THIS MID TO UPPER TROUGH PUSHES AN
ARCTIC FRONT THROUGH THE WATERS THURS NIGHT. STRONG SCA CONDITIONS
WILL EXIST AND WINDS MAY REACH UP TOWARD GALE FORCE OVERNIGHT
THURS INTO FRI MORNING. SEAS NEAR 4 TO 6 FT THURS WILL BUILD IN
RESPONSE TO THESE STRONG SW WINDS HEADING INTO THURS NIGHT. WNA
SHOWS MAX SEAS REACHING AROUND 10 FT NEAR FRYING PAN SHOALS.
OVERALL WILL KEEP SEAS UP TO 7 TO 9 FT IN LOCAL OUTER WATERS
HEADING INTO EARLY FRI MORNING.
ONCE FRONT MOVES OFF THE COAST FURTHER AN OFF SHORE FLOW WESTERLY
FLOW WILL DEVELOP. A COMBINATION OF CAA AND A TIGHTENED GRADIENT
FLOW MAY MAINTAIN SCA CONDITIONS THROUGH FRI NIGHT. SEAS WILL
BEGIN TO DIMINISH ON FRI MAINLY NEAR SHORE AS STRONG WESTERLY
WINDS PERSIST. BY FRI NIGHT SEAS SHOULD BE RUNNING AROUND 3 TO 5 FT.
LONG TERM/SATURDAY THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...SEAS INITIALLY OF 3-4 FT WILL FALL THROUGH
SATURDAY TO 1-2 FT AS NW WINDS EASE TO AROUND 10 KTS AND PUSH THE
HIGHEST WAVES WELL OFFSHORE. WINDS BACK TO THE WSW LATE SAT/EARLY
SUN AHEAD OF A SECONDARY COLD SURGE AND BEGIN TO INCREASE DUE TO
TIGHTENING GRADIENT. SEAS BUILD TO 3-5 FT AS WINDS INCREASE TO 20
KTS AND VEER BACK TO THE NW BEHIND A COLD SURGE LATE SUNDAY. WINDS
VEER FURTHER TO THE NORTHEAST AND SLOWLY DECREASE MONDAY AS HIGH
PRESSURE RIDGES DOWN THE COAST. WIND CHOP OF 3-4 FT WILL PERSIST
MONDAY...EXCEPT ONLY AROUND 1 FT IN THE SHADOWED AREA NEAR SHORE
BRUNSWICK AND HORRY COUNTIES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR AMZ250-252-254-
256.
&&
$$
NEAR TERM...RJD
SHORT TERM...RGZ
LONG TERM...JDW
AVIATION...RJD/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
222 PM EST WED JAN 11 2012
.SYNOPSIS...
A STRONG UPPER LEVEL STORM SYSTEM WILL MOVE ACROSS THE INLAND
CAROLINAS TODAY BRINGING WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS. A WEAK COLD FRONT WILL FOLLOW THIS SYSTEM THIS
EVENING. A DEEP UPPER STORM SYSTEM FORMING OVER THE PLAINS WILL
PREVENT SIGNIFICANTLY COLD AIR FROM MOVING IN THURSDAY. A STRONG
COLD FRONT WILL DRIVE THROUGH THE CAROLINAS LATE THURSDAY BRINGING
A COLDER AND DRY WEEKEND. HIGH PRESSURE WILL MOVE OFF THE COAST
EARLY NEXT WEEK WITH TEMPERATURES RETURNING TO NORMAL.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...WARM FRONT HAS MOVED TO A POSITION FROM HVS
TO BBP TO LBT TO EYF TO BACK ISLAND AND WILL MOVE N OF ALL FORECAST
POINTS BY 1930Z. DEWPOINTS HAVE RISEN INTO THE UPPER 50S AND LOWER
60S IN THE WARM SECTOR. A VERY DYNAMIC SYSTEM WILL AFFECT THE AREA
LATE THIS AFTERNOON AND EVE. THE MAIN SURFACE LOW WILL TRACK ALONG
THE OHIO VALLEY THROUGH TONIGHT. A POTENT SHORTWAVE ROTATING AROUND
THE UPPER LOW WILL HELP TO DEVELOP A SECONDARY AREA OF LOW PRESSURE
WHICH WILL MOVE NE AND ACROSS THE CAROLINA PIEDMONT THIS EVE. IN THE
NARROW WEDGE BETWEEN THE WARM FRONT TO N AND COLD FRONT TO W... THE
AIRMASS WILL BE SLIGHTLY UNSTABLE AND SHEAR WILL INCREASE...
ESPECIALLY IN THE VICINITY OF THE SECONDARY LOW AND WARM FRONT.
AT THIS TIME...THE HIGHEST RISK FOR ANY SEVERE WEATHER WOULD BE N
AND NE OF THE FORECAST AREA WHERE BETTER SHEAR AND INSTABILITY
ALIGN. ONGOING CONVECTION SHOULD LARGELY LIFT OUT THROUGH MID
AFTERNOON. THEN A LINE OF FORCED SHOWERS AND ISOLATED THUNDERSTORMS
IS EXPECTED LATE AFTERNOON AND EVE IMMEDIATELY AHEAD OF THE FRONT...
FROM W TO E. THE ACTUAL COLD FRONT WILL CLEAR THE COAST IN THE
02-04Z TIME FRAME. LOW LEVEL JET OF 50 TO 60 KT WILL PEAK DURING
THIS TIME FRAME. THE LACK OF SIGNIFICANT SURFACE BASED INSTABILITY
MAY MAKE IT DIFFICULT FOR THESE HIGHER WINDS TO MIX TO THE SURFACE.
HOWEVER...STRONG GUSTY WINDS SHOULD BE ABLE TO MIX TO THE SURFACE IN
THE STRONGEST/DEEPEST CONVECTION GIVEN THAT DOWNDRAFT CAPE VALUES
ARE EXPECTED TO BE ABOVE 700 J/KG. MUCH NEEDED RAINFALL HAS ALREADY
FALLEN ACROSS A GOOD CHUNK OF THE AREA WITH A FEW SPOTS REPORTING
ABOUT A HALF INCH. TOTAL RAINFALL AMOUNTS IN THE ONE-HALF TO ONE
INCH RANGE ARE COMMONLY EXPECTED BEFORE THE PUNCH OF DRY AIR REACHES
THE AREA LATER THIS EVE. HIGHEST AMOUNTS WILL LIKELY OCCUR NEAREST
TO THE COAST.
DRIER AND SLIGHTLY COOLER AIR WILL PUNCH IN BEHIND THE COLD FRONT
TONIGHT AND SKIES WILL AT LEAST PARTIALLY CLEAR. EVE TEMPS WILL NOT
CHANGE MUCH AHEAD OF THE COLD FRONT. LOWS EARLY THU MORNING SHOULD
BE IN THE MID AND UPPER 40S WITH PERHAPS A FEW LOWER 50S HANGING ON
AT THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...COLD FRONT WILL BE NORTH AND EAST OF THE AREA
THU MORNING...THOUGH INITIALLY THERE WILL BE NO SIGN OF COLD AIR.
DIGGING 5H TROUGH OVER THE MISSISSIPPI VALLEY HELPS KEEP THE COLD
AIR TO THE WEST THU WITH STRONG SOUTHWEST FLOW PRODUCING 1 LAST DAY
WITH TEMPERATURES IN THE LOW TO MID 60S. ARCTIC COLD FRONT CROSSES
THE AREA LATE THU NIGHT WITH COLD ADVECTION ON ITS HEELS. LIMITED
MOISTURE RETURN AHEAD OF THE FRONT KEEPS FROPA DRY...THOUGH THERE IS
LIKELY TO BE AN INCREASE IN LOW CLOUDS WITH SOUNDINGS SHOWING
INCREASING MOISTURE THROUGH ABOUT 800 MB. THU NIGHT LOW WILL BE
TRICKY...MAINLY DEPENDENT ON TIMING OF THE FRONT/COLD AIR BUT
NUMBERS SHOULD END UP CLOSE TO CLIMO.
COLD AIR ARRIVES FROM THE WEST-SOUTHWEST ON THU NIGHT AND FRI AS
SEVERAL SHORTWAVES ROUND THE BASE OF THE 5H TROUGH THEN HEAD
NORTHEAST. HIGH FRI WILL STRUGGLE TO REACH 50S DESPITE SUNNY TO
MOSTLY SUNNY SKIES. WINDS STAY UP FRI NIGHT AS REINFORCING SHOT OF
COLD AIR ARRIVES LATE. LOWS WILL RANGE FROM UPPER 20S INLAND TO
AROUND 30 AT THE COAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...AMPLIFIED UPPER PATTERN SAT/SUN WILL START
TRANSITIONING TO A PROGRESSIVE/FLAT PATTERN LATE IN THE PERIOD. AIR
MASS MODERATES A LITTLE SAT INTO SUN WITH DEEP WESTERLY FLOW. WINDS
MAY TURN SOUTHWEST LATE SAT NIGHT AND EARLY SUN BEFORE ANOTHER SHOT
OF COLD AIR ARRIVES DURING SUN...ASSOCIATED WITH CLIPPER SYSTEM
CROSS THE MID ATLANTIC. HIGH PRESSURE BUILDS IN FROM THE
WEST...SETTLING OVER THE AREA SUN NIGHT AND PRODUCING WHAT LOOKS TO
BE THE ONLY NIGHT OF REALLY GOOD RADIATIONAL COOLING. WITH UPPER
PATTERN FLATTENING OUT THE SURFACE HIGH IS QUICKLY PUSHED OFFSHORE
MON INTO TUE WITH RETURN FLOW DEVELOPING AND TEMPERATURES RETURNING
TO CLIMO.
00Z GFS/ECMWF CONTINUE TO CARRY A SURFACE SYSTEM BORN OF AN UPPER
WAVE CROSSING THE PLAINS EARLY NEXT WEEK. BOTH HAVE THE SURFACE
FEATURE AND 5H WAVE HEADING NORTH...THROUGH THE GREAT LAKES
REGION...BUT PUSH THE TRAILING COLD FRONT ACROSS THE AREA TUE. STILL
A LOT OF UNCERTAINTY WITH RESPECT TO TUE SO FOR NOW HAVE CONTINUED
THE INHERITED DRY TREND.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...THE HRRR MODEL WAS LEANED ON HEAVILY FOR THE FIRST SIX
HOURS OF TAF TIME. IT HAS BEEN FAIRLY CONSISTENT WITH A GOOD
CONVERGENCE BOUNDARY ALONG THE COAST. BEST CHANCE FOR GUSTY WINDS
AND HEAVY PRECIP WILL BE AT ILM...SECONDARILY THE MYRTLES. INLAND
TERMINALS WILL STILL SEE CONVECTION...JUST WITH LIGHTER PRECIP. LOOK
FOR INTERMITTENT IFR VISIBILITIES AT ILM IN THE HEAVIER SHOWERS.
COLD FRONT WILL APPROACH FROM THE WEST AFTER 02Z...WITH THE BOUNDARY
EXPECTED TO EXIT THE COAST BY 03-04Z. BEHIND THE FRONT...EXPECT
IMPROVING CONDITIONS WITH A WIND SHIFT TO THE WEST SOUTHWEST.
MODERATE MIXING AND COLD AIR ADVECTION WILL KEEP WINDS GUSTY FOR
MUCH OF THE NIGHT...DIMINISHING A BIT AFTER 08Z.
THURSDAY...VFR WITH SCATTERED SKIES AND CONTINUED WEST SOUTHWEST
FLOW...GUSTY AT TIMES.
EXTENDED OUTLOOK...VFR IS EXPECTED THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...SMALL CRAFT ADVISORY WILL REMAIN IN PLACE
INTO THU AFTERNOON. WINDS AND SEAS HAVE BEGUN TO INCREASE AS STRONG
COLD FRONT APPROACHES THE WATERS. THIS FRONT WILL MOVE ACROSS THE
WATERS 03-05Z TIME FRAME. WINDS WILL BE FROM THE S AHEAD OF THE
FRONT AND THEN VEER TO SW. STRONGEST WINDS WILL OCCUR THROUGH THIS
EVE...PEAKING RIGHT AHEAD OF THE FRONT AND THEN TRENDING LOWER
OVERNIGHT. SUSTAINED WINDS AS HIGH AS 25 KT MAY GUST FOR A TIME TO
AROUND 30 KT THIS EVE WITH EVEN HIGHER GUSTS IN THE VICINITY OF
STRONG CONVECTION. THE COOLER SHELF WATERS SHOULD HELP TO DAMPEN THE
STRONGEST OF WINDS AND MARINERS SHOULD BE AWARE THAT EVEN STRONGER
WINDS WILL OCCUR OFFSHORE WHERE WARMER SEA SURFACE TEMPS RESIDE.
SEAS WILL PEAK THIS EVE...IN THE 5 TO 8 FT RANGE...THEN SLOWLY
SUBSIDE AFTER MIDNIGHT. SEAS COULD REACH NEAR 10 FT OUT AROUND
FRYING PAN SHOALS BUOY.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...DESPITE PASSAGE OF COLD FRONT WINDS REMAIN
WEST-SOUTHWEST WITH TIGHT GRADIENT KEEPING SPEEDS CLOSE TO 20 KT
THU. SPEEDS INCREASE THU NIGHT AS ARCTIC FRONT CROSSES THE WATERS.
STRONG COLD ADVECTION AND TIGHT GRADIENT IN THE WAKE OF THE FRONT
WILL KEEP SPEEDS OVER 20 KT AND GUSTY. WINDS EVENTUALLY BECOME
OFFSHORE FRI...BUT NOT BEFORE SEAS AREA ABLE TO BUILD CLOSE TO 10 FT
WELL AWAY FROM SHORE. SCA WILL LIKELY BE IN EFFECT INTO FRI
AFTERNOON AND POSSIBLY FRI EVENING FOR NC WATERS. ANOTHER SHOT OF
COLD AIR ARRIVES LATE FRI NIGHT WITH WEST WINDS SHIFTING TO
NORTHWEST...BUT REMAINING AROUND 15 KT...BY THE END OF THE PERIOD.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...10 TO 15 KT WESTERLY FLOW SAT MAY BRIEFLY
BECOME SOUTHWEST SAT NIGHT BEFORE NEXT SURGE OF COLD AIR ARRIVES
SUN. ARRIVAL OF COLD AIR COINCIDES WITH PINCHED GRADIENT...FROM
APPROACH AND THEN PASSAGE OF CLIPPER SYSTEM TO THE NORTH...WHICH
INCREASES NORTHWEST WINDS TO 15 TO 20 KT. OFFSHORE COMPONENT SHOULD
KEEP SEAS WITH 20 NM IN THE 2 TO 4 FT RANGE...BUT SPEEDS ON SUN MAY
WARRANT A SCEC.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
THURSDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...RJD
SHORT TERM...III
LONG TERM...III
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1155 AM EST WED JAN 11 2012
.SYNOPSIS...
A STRONG UPPER LEVEL STORM SYSTEM WILL MOVE ACROSS THE INLAND
CAROLINAS TODAY BRINGING WIDESPREAD SHOWERS AND EMBEDDED
THUNDERSTORMS. A WEAK COLD FRONT WILL FOLLOW THIS SYSTEM THIS
EVENING. A DEEP UPPER STORM SYSTEM FORMING OVER THE PLAINS WILL
PREVENT SIGNIFICANTLY COLD AIR FROM MOVING IN THURSDAY. A STRONG
COLD FRONT WILL DRIVE THROUGH THE CAROLINAS LATE THURSDAY BRINGING
A COLDER AND DRY WEEKEND. HIGH PRESSURE WILL MOVE OFF THE COAST
EARLY NEXT WEEK WITH TEMPERATURES RETURNING TO NORMAL.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...A WARM FRONT HAS BEGUN TO MOVE ACROSS THE
AREA AND WILL MOVE N OF THE ENTIRE FORECAST AREA THROUGH EARLY
AFTERNOON. ISENTROPIC UPGLIDE WILL CONTRIBUTE TO THE DEVELOPMENT OF
SHOWERS. A VERY DYNAMIC SYSTEM ACROSS THE MID SOUTH WILL AFFECT THE
EASTERN CAROLINAS LATE THIS AFTERNOON AND EVE. THE MAIN SURFACE LOW
WILL TRACK ACROSS THE CENTRAL APPALACHIANS THIS AFTERNOON. A POTENT
SHORTWAVE ROTATING AROUND THE UPPER LOW WILL HELP TO DEVELOP A
SECONDARY AREA OF LOW PRESSURE ACROSS THE PIEDMONT OF NORTH
CAROLINA. IN THE NARROW WEDGE BETWEEN WARM FRONT TO N AND COLD FRONT
TO W...AIRMASS WILL BECOME SLIGHTLY UNSTABLE. SHEAR WILL INCREASE AS
WEAK SURFACE LOW DEVELOPS LATER THIS AFTERNOON AND EVE. THE
JUXTAPOSITION AND EVENTUAL TRACK OF THIS FEATURE WILL DETERMINE
WHERE ISOLATED SEVERE WEATHER WILL THREATEN. AT THIS TIME...THE
HIGHEST RISK FOR ANY SEVERE WEATHER WOULD BE N AND NE OF THE
FORECAST AREA WHERE BETTER SHEAR AND INSTABILITY LINE UP. A LINE OF
FORCED SHOWERS AND ISOLATED THUNDERSTORMS AHEAD OF THE COLD FRONT IS
EXPECTED LATE AFTERNOON AND EVE...FROM W TO E. THE ACTUAL COLD FRONT
WILL CLEAR THE COAST IN THE 02-04Z TIME FRAME. LOW LEVEL JET OF 50
TO 60 KT WILL BE PEAKING DURING THIS TIME FRAME. THE LACK OF SURFACE
BASED INSTABILITY WILL MAKE IT DIFFICULT FOR THESE HIGHER WINDS TO
MIX TO THE SURFACE. HOWEVER...STRONG GUSTY WINDS SHOULD BE ABLE TO
MIX TO THE SURFACE IN THE STRONGEST/DEEPEST CONVECTION. MUCH NEEDED
RAINFALL IS STILL IN THE FORECAST AND RAINFALL AMOUNTS IN THE
ONE-HALF TO ONE INCH RANGE ARE COMMONLY EXPECTED WITH THE BULK
ARRIVING IN THE LATE AFTERNOON AND EVE HOURS.
WARM FRONTAL PASSAGE SHOULD ALLOW ALL AREAS TO REACH THE LOWER TO
MID 60S THIS AFTERNOON...HIGHEST SW. DRIER AND SLIGHTLY COOLER AIR
WILL PUNCH IN BEHIND THE COLD FRONT TONIGHT AND SKIES WILL AT LEAST
PARTIALLY CLEAR. LOWS EARLY ON THU SHOULD BE IN THE MID AND UPPER
40S WITH PERHAPS A FEW LOWER 50S HANGING ON AT THE COAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...COLD FRONT WILL BE NORTH AND EAST OF THE AREA
THU MORNING...THOUGH INITIALLY THERE WILL BE NO SIGN OF COLD AIR.
DIGGING 5H TROUGH OVER THE MISSISSIPPI VALLEY HELPS KEEP THE COLD
AIR TO THE WEST THU WITH STRONG SOUTHWEST FLOW PRODUCING 1 LAST DAY
WITH TEMPERATURES IN THE LOW TO MID 60S. ARCTIC COLD FRONT CROSSES
THE AREA LATE THU NIGHT WITH COLD ADVECTION ON ITS HEELS. LIMITED
MOISTURE RETURN AHEAD OF THE FRONT KEEPS FROPA DRY...THOUGH THERE IS
LIKELY TO BE AN INCREASE IN LOW CLOUDS WITH SOUNDINGS SHOWING
INCREASING MOISTURE THROUGH ABOUT 800 MB. THU NIGHT LOW WILL BE
TRICKY...MAINLY DEPENDENT ON TIMING OF THE FRONT/COLD AIR BUT
NUMBERS SHOULD END UP CLOSE TO CLIMO.
COLD AIR ARRIVES FROM THE WEST-SOUTHWEST ON THU NIGHT AND FRI AS
SEVERAL SHORTWAVES ROUND THE BASE OF THE 5H TROUGH THEN HEAD
NORTHEAST. HIGH FRI WILL STRUGGLE TO REACH 50S DESPITE SUNNY TO
MOSTLY SUNNY SKIES. WINDS STAY UP FRI NIGHT AS REINFORCING SHOT OF
COLD AIR ARRIVES LATE. LOWS WILL RANGE FROM UPPER 20S INLAND TO
AROUND 30 AT THE COAST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...AMPLIFIED UPPER PATTERN SAT/SUN WILL START
TRANSITIONING TO A PROGRESSIVE/FLAT PATTERN LATE IN THE PERIOD. AIR
MASS MODERATES A LITTLE SAT INTO SUN WITH DEEP WESTERLY FLOW. WINDS
MAY TURN SOUTHWEST LATE SAT NIGHT AND EARLY SUN BEFORE ANOTHER SHOT
OF COLD AIR ARRIVES DURING SUN...ASSOCIATED WITH CLIPPER SYSTEM
CROSS THE MID ATLANTIC. HIGH PRESSURE BUILDS IN FROM THE
WEST...SETTLING OVER THE AREA SUN NIGHT AND PRODUCING WHAT LOOKS TO
BE THE ONLY NIGHT OF REALLY GOOD RADIATIONAL COOLING. WITH UPPER
PATTERN FLATTENING OUT THE SURFACE HIGH IS QUICKLY PUSHED OFFSHORE
MON INTO TUE WITH RETURN FLOW DEVELOPING AND TEMPERATURES RETURNING
TO CLIMO.
00Z GFS/ECMWF CONTINUE TO CARRY A SURFACE SYSTEM BORN OF AN UPPER
WAVE CROSSING THE PLAINS EARLY NEXT WEEK. BOTH HAVE THE SURFACE
FEATURE AND 5H WAVE HEADING NORTH...THROUGH THE GREAT LAKES
REGION...BUT PUSH THE TRAILING COLD FRONT ACROSS THE AREA TUE. STILL
A LOT OF UNCERTAINTY WITH RESPECT TO TUE SO FOR NOW HAVE CONTINUED
THE INHERITED DRY TREND.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 17Z...THE HRRR MODEL WAS LEANED ON HEAVILY FOR THE FIRST SIX
HOURS OF TAF TIME. IT HAS BEEN FAIRLY CONSISTENT WITH A GOOD
CONVERGENCE BOUNDARY ALONG THE COAST. BEST CHANCE FOR GUSTY WINDS
AND HEAVY PRECIP WILL BE AT ILM...SECONDARILY THE MYRTLES. INLAND
TERMINALS WILL STILL SEE CONVECTION...JUST WITH LIGHTER PRECIP. LOOK
FOR INTERMITTENT IFR VISIBILITIES AT ILM IN THE HEAVIER SHOWERS.
COLD FRONT WILL APPROACH FROM THE WEST AFTER 02Z...WITH THE BOUNDARY
EXPECTED TO EXIT THE COAST BY 03-04Z. BEHIND THE FRONT...EXPECT
IMPROVING CONDITIONS WITH A WIND SHIFT TO THE WEST SOUTHWEST.
MODERATE MIXING AND COLD AIR ADVECTION WILL KEEP WINDS GUSTY FOR
MUCH OF THE NIGHT...DIMINISHING A BIT AFTER 08Z.
THURSDAY...VFR WITH SCATTERED SKIES AND CONTINUED WEST SOUTHWEST
FLOW...GUSTY AT TIMES.
EXTENDED OUTLOOK...VFR IS EXPECTED THROUGH THE EXTENDED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...WINDS SHOULD RAMP HIGHER IN THE WARM SECTOR
AHEAD OF THE COLD FRONT. THE COOLER SHELF WATERS SHOULD HELP TO
DAMPEN THE STRONGEST OF WINDS WHICH WILL BE OCCURRING OFFSHORE WHERE
WARMER SEA SURFACE TEMPS RESIDE. STILL...THE SYSTEM IS DYNAMIC AND
WITH A 50 TO 60 KT LOW LEVEL JET IMPINGING ON THE AREA LATER THIS
AFTERNOON AND THIS EVE...A SMALL CRAFT ADVISORY WILL REMAIN IN PLACE.
SOUTH WINDS WILL INCREASE TO 20 TO 25 KT LATER AFTERNOON AND PERSIST
INTO THIS EVE...VEERING TO SW IN THE WAKE OF THE COLD FRONT. SEAS
WILL BUILD QUICKLY AND WILL CONTINUE TO SHOW SEAS BUILDING TO 5 TO 8
FT ACROSS THE MAJORITY OF THE WATERS...HIGHEST BEYOND 10 NM.
WIND AND ESPECIALLY SEAS WILL SUBSIDE OVERNIGHT.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...DESPITE PASSAGE OF COLD FRONT WINDS REMAIN
WEST-SOUTHWEST WITH TIGHT GRADIENT KEEPING SPEEDS CLOSE TO 20 KT
THU. SPEEDS INCREASE THU NIGHT AS ARCTIC FRONT CROSSES THE WATERS.
STRONG COLD ADVECTION AND TIGHT GRADIENT IN THE WAKE OF THE FRONT
WILL KEEP SPEEDS OVER 20 KT AND GUSTY. WINDS EVENTUALLY BECOME
OFFSHORE FRI...BUT NOT BEFORE SEAS AREA ABLE TO BUILD CLOSE TO 10 FT
WELL AWAY FROM SHORE. SCA WILL LIKELY BE IN EFFECT INTO FRI
AFTERNOON AND POSSIBLY FRI EVENING FOR NC WATERS. ANOTHER SHOT OF
COLD AIR ARRIVES LATE FRI NIGHT WITH WEST WINDS SHIFTING TO
NORTHWEST...BUT REMAINING AROUND 15 KT...BY THE END OF THE PERIOD.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...10 TO 15 KT WESTERLY FLOW SAT MAY BRIEFLY
BECOME SOUTHWEST SAT NIGHT BEFORE NEXT SURGE OF COLD AIR ARRIVES
SUN. ARRIVAL OF COLD AIR COINCIDES WITH PINCHED GRADIENT...FROM
APPROACH AND THEN PASSAGE OF CLIPPER SYSTEM TO THE NORTH...WHICH
INCREASES NORTHWEST WINDS TO 15 TO 20 KT. OFFSHORE COMPONENT SHOULD
KEEP SEAS WITH 20 NM IN THE 2 TO 4 FT RANGE...BUT SPEEDS ON SUN MAY
WARRANT A SCEC.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
THURSDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...RJD
SHORT TERM...III
LONG TERM...III
AVIATION...DL
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
352 PM CST WED JAN 11 2012
.SHORT TERM...
THE SURFACE PRESSURE GRADIENT SUPPORTING TODAYS STIFF NORTHERLY
WINDS IS EXPECTED TO EASE STEADILY THIS EVENING...WITH DROP IN MOST
SURFACE WIND SPEEDS NEAR OR PRIOR TO 00Z THIS EVENING. OUR PLAN IS
TO ALLOW THE WIND ADVISORY TO RUN ITS COURSE UNTIL 00Z WITH NO
EXTENSION. WINDS PROBABLY WILL BE SLOWEST TO DROP THIS EVENING OVER
THE ROLLING PLAINS AND MAY RETAIN GREATER THAN 10 MPH WINDS UNTIL
CLOSE TO DAYBREAK ON THURSDAY. THIS SHOULD KEEP ESPECIALLY THE
SOUTHERN ROLLING PLAINS BETTER MIXED WHILE LOW TEMPERATURES
OTHERWISE TONIGHT SHOULD DROP INTO TEENS ON MOST OF THE CAPROCK AND
LOW TO MID 20S OVER ROLLING PLAINS. THE UPPER FLOW SHOULD REMAIN
SLIGHTLY ANTICYCLONICALLY CURVED IN NORTHWEST FLOW ALOFT WITH A
BRANCH OF THE POLAR JET STILL OVER THE AREA UNTIL MIDDAY THURSDAY.
THIS MAY LEAD TO AREAS OF MID CLOUDS AGAIN LATER TONIGHT AND/OR
THROUGH THURSDAY...THOUGH SOMEWHAT DIFFICULT TO ANTICIPATE. LOW
CLOUDS TONIGHT ALSO SOMEWHAT UNCERTAIN GIVEN PREDOMINANT NORTHERLY
LOW LEVEL FLOW AND VERY DRY AIR...THOUGH RUC INDICATES ABOUT 20
DEGREES MORE NORTHEAST COMPONENT AND MAINTAINS MORE H850 LAYER
MOISTURE ACROSS NORTHERN AND EASTERN ZONES. SO...APPEARS PERHAPS
BEST AREAS FOR MVFR LAYER LOW CLOUDS WOULD BE ACROSS NORTHEAST ZONES
BUT CANT RULE OUT FOR CENTRAL. EITHER WAY...A CHILLY NIGHT WILL
OCCUR WITH A FLATTER SURFACE PRESSURE GRADIENT DOMINATING THROUGH
MUCH OF THURSDAY. TRENDED HIGHS THURSDAY VERY SLIGHTLY UPWARDS ALONG
LINES OF GUIDANCE TRENDS AS WELL. RMCQUEEN
&&
.LONG TERM...
EXPECT DRY CONDITIONS AND MODERATING TEMPERATURES LATE WEEK ON
THROUGH THE WEEKEND. INITIALLY...A SHORTWAVE TROUGH EMBEDDED WITHIN
NORTHWESTERLY FLOW ALOFT WILL TRAVERSE THE AREA FRIDAY. THIS
DISTURBANCE WILL GENERATE AREAS OF MID/HIGH CLOUD BUT LITTLE ELSE.
THE NORTHWESTERLY FLOW WILL BACK WITH TIME WITH A PROGRESSIVE UPPER
RIDGE TRANSLATING OVER SATURDAY NIGHT AND SUNDAY. THIS
PATTERN...COMBINED WITH INCREASING SOUTHERLY/SOUTHWESTERLY LOW-
LEVEL FLOW...WILL PUSH HIGHS BACK ABOVE AVERAGE OVER THE WEEKEND
/LIKELY ECLIPSING THE 60 DEGREE MARK BY SUNDAY/. ONE MINOR CAVEAT
REVOLVE AROUND A CLIPPER SYSTEM DIVING INTO THE UPPER MIDWEST THAT
MAY ATTEMPT TO BACKDOOR A WEAK COLD FRONT INTO THE NORTHEAST ZONES
ON SATURDAY. EVEN IF THIS FRONT DOES MAKE IT INTO THE AREA...ONLY
MINOR IMPACTS ARE EXPECTED. THUS...HAVE TRENDED FORECAST
TEMPERATURES UP A NOTCH OVER THE WEEKEND.
ATTENTION WILL THEN TURN TO ANOTHER SHORTWAVE TROUGH /THE REMNANTS
OF THE CUTOFF LOW CURRENTLY SPINNING WELL OFF THE CALIFORNIA COAST/
THAT WILL RACE BY THE REGION IN NEAR ZONAL FLOW ALOFT ON MONDAY.
UNFORTUNATELY THE PROGRESSIVE AND OPENING/WEAKENING NATURE OF THE
SYSTEM...ALONG WITH THE DEARTH OF LOW-LEVEL MOISTURE TO WORK
WITH...WILL LIKELY KEEP THIS SYSTEM A DRY ONE LOCALLY. HOWEVER...IF
YOU LIKE WIND YOU MAY BE IN STORE FOR ANOTHER TREAT AS THE LATEST
GUIDANCE AND RAW NWP MODEL OUTPUT SUGGEST WESTERLY WINDS MAY
APPROACH OR EXCEED ADVISORY LEVELS DURING THE DAY MONDAY.
HENCE...HAVE TRENDED WINDS SPEEDS UPWARD IN THE GRIDS...THOUGH A
TOUCH BELOW ADVISORY LEVELS AT THIS POINT. THESE WINDS COULD ALSO
LOFT A BIT OF BLOWING DUST /LIKE TODAY/ AND ALSO ELEVATE THE FIRE
DANGER. HOWEVER...CURRENT PROJECTIONS DO KEEP HUMIDITIES ABOVE MORE
CRITICAL THRESHOLDS...THOUGH THIS COULD BE A BIT OPTIMISTIC AS IS
OFTEN THE CASE IN THE STRONG WESTERLY FLOW REGIME.
BEYOND MONDAY...A COLD FRONT IS PROGGED TO MOVE THROUGH EARLY
TUESDAY...DROPPING TEMPERATURES TOWARD MORE SEASONAL LEVELS. THE
LATEST ROUND OF MODEL SOLUTIONS HAVE TRENDED A LITTLE STRONGER WITH
THE FRONT...PUSHING IT THROUGH THE ENTIRE FA...AND HAVE FOLLOWED
SUITE IN THE GRIDS. THIS COOL-DOWN SHOULD BE RELATIVELY SHORT-LIVED
THOUGH AS THE SFC RIDGE IS QUICKLY SHUNTED EASTWARD UNDER MODERATE
TO STRONG MID-LEVEL ZONAL FLOW IN PLACE ACROSS MUCH OF THE CONUS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 16 41 18 47 23 / 10 0 0 0 0
TULIA 17 42 17 49 22 / 10 0 0 0 0
PLAINVIEW 18 42 19 50 23 / 10 0 0 0 0
LEVELLAND 19 43 21 51 25 / 10 0 0 0 0
LUBBOCK 19 43 21 52 23 / 10 0 0 0 0
DENVER CITY 21 42 23 49 26 / 0 0 0 0 0
BROWNFIELD 22 43 23 50 25 / 0 0 0 0 0
CHILDRESS 23 45 20 53 24 / 10 0 0 0 0
SPUR 24 46 23 53 26 / 10 0 0 0 0
ASPERMONT 25 46 25 54 25 / 10 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021>044.
&&
$$
05/23
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1156 AM CST WED JAN 11 2012
.AVIATION...
FOR THE 18Z TAFS...EXPECT MVFR CIGS TO PERSIST THRU THE AFTERNOON
HOURS AT ALL SITES IN RESPONSE TO COLD UPPER LEVEL STORM SYSTEM WHICH
IS FCST TO SWING BY TO THE NORTH OF THE TX AND OK PNHDLS. ONLY A FEW
SNOW FLURRIES ARE PSBL AT BEST ACROSS NRN TAF SITES. WINDS WILL ALSO
REMAIN STRONG THIS AFTERNOON...WITH AVIATION WEATHER WARNING IN
EFFECT FOR KAMA TIL 23Z TODAY. WINDS AND CLOUDS WILL SLOWLY DIMINISH
DURG THE COURSE OF THE EVENING HOURS WITH VFR CONDITIONS ANTICIPATED
BY LATE TONIGHT.
ANDRADE
&&
.PREV DISCUSSION... /ISSUED 601 AM CST WED JAN 11 2012/
AVIATION...
MAIN CONCERNS FOR THIS TAF CYCLE ARE STRONG WINDS AND MVFR CIGS.
COLD FRONT WILL MOVE THROUGH THE PANHANDLES THIS MORNING...WITH GUSTY
NORTHERLY WINDS IN ITS WAKE. THESE WINDS WILL INCREASE BETWEEN 14Z
AND 16Z...WITH 40 KNOTS POSSIBLE AT AMA INTO THE AFTERNOON. AWW WILL
CONTINUE AT AMA UNTIL 23Z. LATEST RUC FORECAST SOUNDINGS SHOW MVFR
CIGS HANGING AROUND UNTIL 00Z AND HAVE INCLUDED IN THE LATEST TAFS.
VFR CONDITIONS ANTICIPATED AFTER 00Z. NORTHERLY WINDS WILL ALSO
SUBSIDE BY 00Z...BUT GUST BETWEEN 20 AND 22 KNOTS UNTIL 06Z.
PREV DISCUSSION... /ISSUED 330 AM CST WED JAN 11 2012/
DISCUSSION...
COLD FRONT CURRENTLY THROUGH NORTHWESTERN KANSAS WILL MAKE ITS
PRESENCE KNOWN ACROSS PANHANDLES THIS MORNING. NORTH WINDS BEHIND
FRONT ARE EXPECTED TO REMAIN BELOW ADVISORY LEVELS. WIND CHILL
VALUES TODAY WILL REMAIN BELOW 32 DEGREES ACROSS ALL BUT FAR
SOUTHERN SECTIONS.
NO MEASURABLE PRECIPITATION IS EXPECTED TODAY...BUT HAVE INCLUDED
SCATTERED FLURRIES THIS AFTERNOON ACROSS NORTHERN SECTIONS...WHERE
POTENT VORTICITY MAXIMUM WILL TRAVERSE. NO PRECIPITATION IN
REMAINDER OF FORECAST.
WINDY CONDITIONS WILL END EARLY THIS EVENING...WITH CLEARING SKY
ALLOWING TEMPERATURES TO FALL INTO THE 10 TO 20 DEGREE RANGE AREA
WIDE. DEEP NORTHWEST FLOW ON THURSDAY WILL MAKE FOR ANOTHER COOL
DAY.
WARMING TREND BEGINS ON FRIDAY AS MID-LEVEL HEIGHTS RISE AND
SOUTHWEST SURFACE WINDS RESUME. WEAK COLD FRONT OR BRIEF WIND SHIFT
ON SATURDAY WILL HAVE MINIMAL IMPACT. DEEPENING SURFACE TROF SUNDAY
AND MONDAY EXPECTED TO RESULT IN MAXIMUM TEMPERATURES 10 TO 15
DEGREES ABOVE NORMAL. BACK DOOR COLD FRONT MONDAY NIGHT EXPECTED TO
PASS DRYLY...WITH COOLER CONDITIONS ON TUESDAY. 03
COCKRELL
FIRE WEATHER...
NORTH WINDS WILL DEVELOP THIS MORNING FOLLOWING THE PASSAGE OF A
STRONG COLD FRONT...BUT RELATIVE HUMIDITY VALUES WILL REMAIN WELL
ABOVE CRITICAL OR ELEVATED THRESHOLDS. NORTHWEST WINDS ON THURSDAY
WILL BE GUSTY MUCH OF THE DAY...AND THEN DIMINISH BY LATE
AFTERNOON. WINDS WILL BE MUCH LIGHTER FRIDAY AND SATURDAY.
SOUTHWEST WINDS INCREASE ON SUNDAY AND MONDAY...POSSIBLY RESULTING
IN ELEVATED FIRE WEATHER CONDTIONS ACROSS THE WESTERN HALF OF THE
FORECAST AREA. 03
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
225 PM CST WED JAN 11 2012
.SHORT TERM...
.TONIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH.
DECIDED ON A WINTER WEATHER ADVISORY HEADLINE INSTEAD OF A WINTER
STORM WARNING DUE TO THE LONG DURATION OF THIS EVENT.
SFC WIND SHIFT AND COLD FRONT JUST GETTING INTO WEST CENTRAL WI THIS
AFTERNOON BRINGING INTIALLY JUST LOW CLOUDS. TIMING OF THIS FRONT
GETTING INTO SOUTH CENTRAL WI KEEPS TRENDING SLOWER.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW 500MB LOW OVER
SOUTHEASTERN U.S. AND AN ELONGATED TROUGH DIPPING DOWN INTO THE
DAKOTAS. THE LONGWAVE TROUGH WILL BECOME A CLOSED 500MB LOW OVER
MO/IL BETWEEN 18Z THU AND 00Z FRI...WHICH WILL FURTHER DEEPEN AND
BECOME NEGATIVELY TILTED AS IT MOVES EAST INTO OHIO 06Z-12Z FRI.
EVEN THOUGH THE TWO UPPER LEVEL SYSTEMS WILL NOT MERGE...THE
MOISTURE WRAPPED INTO THE SOUTHEAST LOW WILL BE PULLED NORTHWESTWARD
INTO THE UPPER GREAT LAKES REGION. 285K TO 300K ISENTROPIC LIFT WILL
BRING AN EXTRA SURGE OF MOISTURE LIFT INTO LAKE MICHIGAN AND EASTERN
WI BETWEEN 18Z THU-06Z FRI. THIS WILL COMBINE WITH OMEGA VALUES OF
-5 TO -6 IN THE DENDRITIC GROWTH ZONE TO CREATE MODERATE SNOW AND
HALF INCH PER HOUR SNOWFALL RATES.
COLD TEMPS FLOWING INTO THE REGION WITH THE STRONG COLD FRONT WILL
BLOW THE SNOW AROUND THU AFTERNOON AND HELP TO KNOCK DOWN SNOW
RATIOS LATER THU AFTERNOON AND THU NIGHT. NAM SNOW RATIOS IN THE 14
TO 16:1 RANGE LOOK GOOD THROUGH 21Z THU...THEN CUT THE NAM RATIOS
DOWN A BIT TO STAY WITHIN THE 15 TO 17:1 RANGE THROUGH 06Z FRI.
IT/S IMPORTANT TO STRESS THAT THE CALCULATED SNOWFALL TOTALS OF 6 TO
8 INCHES WILL FALL OVER A VERY LONG TIME PERIOD FROM LATE TONIGHT
THROUGH EARLY FRIDAY AFTERNOON. THIS STORM TOTAL WAS DETERMINED BY
ADDING UP 6-HOURLY SNOWFALL GRIDS...AND DOES NOT REPRESENT HOW MANY
INCHES WILL BE ON A SNOW BOARD BY THE END OF THE EVENT. USE CAUTION
WHEN SITING THE STORM TOTAL SNOWFALL AMOUNTS!
THE BRUNT OF THE SNOW WILL COME BETWEEN MID THU MORNING AND MID THU
EVENING. THE MORNING COMMUTE IN MADISON WILL BE MESSY IF THIS STORM
KEEPS ITS CURRENT PACE. THE AFTERNOON COMMUTE WILL BE MESSY IN BOTH
MADISON AND MILWAUKEE WITH THE HIGHER SNOW RATES AND WIND BLOWING
THE SNOW AROUND. GIVEN THE LONG DURATION EVENT...SNOW PLOWS SHOULD
BE ABLE TO KEEP UP WITH THE SNOWFALL...WITH HIGHEST SNOW RATES OF A
HALF INCH PER HOUR FOR 4 TO 6 HOURS.
.THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE...MEDIUM
MID/UPPER TROUGH EXITS THE EASTERN GREAT LAKES REGION BY FRIDAY.
STRONG SURFACE LOW OVER LOWER MICHIGAN THURSDAY EVENING REACHES
THE EASTERN GREAT LAKES EARLY FRIDAY MORNING. ACCUMULATING SNOW
SHOULD CONTINUE THURSDAY EVENING...DIMINISHING BY FRIDAY MORNING.
12Z NAM/ECMWF SIMILAR IN PRECIPITATION AMOUNTS WITH THE GFS
SLIGHTLY LOWER.
LONG DURATION SNOW EVENT BUT APPEARS NO 12 HOUR PERIOD WILL REACH
6 INCHES AND 24 HOUR PERIOD WILL NOT REACH 8 INCHES SO WILL GO
WITH ADVISORY HEADLINES. WINDS/AND SOME BLOWING DRIFTING
SNOW...ESPECIALLY THURSDAY EVENING...BUT THIS NOT SEEM TO BE TOO
SEVERE TO WARRANT AN UPGRADE TO WARNING STATUS.
.LONG TERM...
.FRIDAY NIGHT AND SATURDAY......FORECAST CONFIDENCE...MEDIUM
SHORTWAVE IN THE NORTHWEST MID/UPPER LEVEL FLOW WILL MOVE ACROSS
THE NORTHERN PLAINS FRIDAY NIGHT AND MOVE ACROSS NORTHERN ILLINOIS
ON SATURDAY. ASSOCIATED WEAK SURFACE LOW IS EXPECTED TO TRACK
ACROSS NORTHERN ILLINOIS OR FAR SOUTHERN WISCONSIN. AN INCH OR
LESS OF SNOW POSSIBLE.
.SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE...MEDIUM
NORTHWEST MID/UPPER LEVEL FLOW SUNDAY UNTIL A RIDGE BUILDS INTO
WISCONSIN SUNDAY NIGHT AS A SHORTWAVE DIGS OVER THE WESTERN U.S.
AS A RESULT A SURFACE HIGH SHOULD EXTEND ACROSS THE GREAT LAKES.
SOUTH WINDS WILL INCREASE SUNDAY NIGHT AHEAD OF THE SURFACE TROUGH.
BY MONDAY MID/UPPER LEVEL FLOW BECOMES SOUTHWEST AS THE SHORTWAVE
MOVES EAST INTO THE ROCKIES/HIGH PLAINS REGION. BOTH THE 12Z GFS
AND 12Z ECMWF BRINGS A SURFACE TROUGH TO THE MISSISSIPPI VALLEY
WITH LIGHT PRECIPITATION SPREADING NORTH INTO SOUTHERN WISCONSIN.
BY THIS TIME THICKNESS VALUES RISE ABOVE 540 DM.
THE SHORTWAVE TROUGH SHOULD REACH THE UPPER MISSISSIPPI VALLEY
MONDAY NIGHT AND REACH THE GREAT LAKES ON TUESDAY. PRECIPITATION
SHOULD MIX WITH/CHANGE TO SNOW BEHIND THE SURFACE TROUGH/COLD FRONT.
PRECIPITATION WILL DIMINISH/END MONDAY NIGHT.
.TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM
SURFACE HIGH BUILDS INTO WISCONSIN TUESDAY NIGHT BEFORE THE HIGH
MOVES ACROSS KENTUCKY.
&&
.AVIATION/00Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH ABOUT 01Z AT KMSN AND 05Z AT KMKE
AND OTHER SE WI TAF SITES. WEDGE OF CLEAR SKIES BETWEEN SYSTEM TO
OUR SOUTH AND APPROACHING ONE TO THE NORTHWEST SHOULD LAST INTO THE
EARLY EVENING WITH SOME HIGH CLOUDS INITIALLY SPREADING IN. LOW
CLOUDS WITH MVFR CONDITIONS WILL SINK QUICKLY TO IFR IN THE WAKE OF
THE PASSING COLD FRONT BETWEEN 01-05Z THU. ANY SNOW AT KMSN SHOULD
HOLD OFF UNTIL AFTER 06Z THU AND AFTER 12Z THU AT KMKE.
INITIAL SNOW IS EXPECTED TO BE LIGHT...THEN THE BEST STORM DYNAMICS
MOVE ACROSS WI FROM WEST TO EAST 12-18Z THU AND REMAIN NEARLY
STATIONARY OVER SOUTH CENTRAL AND SOUTHEAST WI THROUGH 00Z TO 06Z
FRI AS SFC LOW PRESSURE REGROUPS OVER SOUTHEAST LOWER
MICHIGAN...OCCLUDES AND WAITS FOR THE 500MB UPPER LOW TO SHIFT
EASTWARD ACROSS ILLINOIS AND INDIANA.
TOTAL SNOW AMOUNTS UP TO 8 INCHES WILL FALL OVER A VERY LONG TIME
PERIOD...RUNNING FROM LATE TONIGHT THROUGH FRIDAY MORNING. THE
HEAVIEST PERIOD WOULD BE BETWEEN 18Z THU THROUGH 06Z FRIDAY WHERE UP
TO 4 INCHES COULD FALL.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 6 AM THURSDAY TO 6 AM CST FRIDAY
FOR WIZ047-057-063-068.
WINTER WEATHER ADVISORY FROM 9 AM THURSDAY TO 9 AM CST FRIDAY
FOR WIZ051-052-058>060-064>066-069>072.
WINTER WEATHER ADVISORY FROM 3 AM THURSDAY TO 6 AM CST FRIDAY
FOR WIZ046-056-062-067.
LM...SMALL CRAFT ADVISORY FROM 9 AM THURSDAY TO MIDNIGHT CST FRIDAY
NIGHT FOR LMZ643>646.
&&
$$
TONIGHT/THURSDAY AND AVIATION/MARINE...MRC
THURSDAY NIGHT THROUGH WEDNESDAY...HENTZ