Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 11/19/11
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
305 PM CST THU NOV 17 2011
.SYNOPSIS...
12Z UA ANALYSIS HAS AN EXTRATROPICAL CYCLONE OVER THE SOUTHEAST
CONUS WITH A NEW SYSTEM MOVING ON SHORE INTO THE PACIFIC NORTHWEST
AND BRITISH COLUMBIA. AN UPPER RIDGE RAN FROM THE SOUTHERN PLAINS
NORTH INTO THE CANADIAN PLAINS. WEAK TROFS WERE OVER THE GREAT LAKES
WITH MORE ACROSS THE ROCKIES. SATELLITE TRENDS THROUGH EARLY
AFTERNOON INDICATE GENERALLY CLEAR SKIES ACROSS THE AREA BUT WAA
CI/CS CLOUDS AHEAD OF THE NEXT SYSTEM WERE MOVING SOUTHEAST FROM THE
NORTHERN PLAINS.
18Z SFC ANALYSIS HAS THE RIDGE AXIS RUNNING FROM MINNESOTA INTO
EASTERN IOWA AND THEN INTO EASTERN TEXAS. A WARM FRONT RAN FROM
NORTHEAST MONTANA INTO CENTRAL NEBRASKA. SEVERAL WEAK TROFS RAN FROM
THE EASTERN GREAT LAKES INTO THE UPPER MIDWEST. DEW POINTS WERE IN
THE TEENS AND 20S ACROSS THE MIDWEST AND PLAINS.
&&
.SHORT TERM...TONIGHT AND FRIDAY...
QUIET AND DRY WX WILL CONTINUE FOR TONIGHT AND FRIDAY. THE PROXIMITY
OF THE SFC RIDGE SHOULD RESULT IN A QUICK DROP OFF IN TEMPERATURES
WITH SUNSET. RETURN WAA DEVELOPS BY MID TO LATE EVENING SO AFTER THE
INITIAL DROP OFF TEMPERATURES SHOULD REMAIN STEADY FOR A WHILE WITH
A VERY SLOW CLIMB EXPECTED AFTER MIDNIGHT. SINCE TEMPERATURES ARE
STRUGGLING TO CLIMB THIS AFTERNOON...MINS TONIGHT SHOULD BE A BIT
LOWER WITH 25 TO 30 COMMON.
ON FRIDAY THE INVERSION WILL START TO MIX OUT AROUND MID MORNING
ALLOWING WINDS TO JUMP. HOWEVER...FCST SOUNDINGS ONLY SUGGEST MIXING
UP TO ABOUT 875MB. THIS LOWER MIXING HEIGHT THEN AFFECTS HOW WARM IT
WILL GET IN SPITE OF THE WAA OCCURRING. THE FACT THAT THE INVERSION
DOES NOT ENTIRELY MIX OUT INDICATES THE HIGHER MOMENTUM AIR WILL
HAVE TROUBLE MIXING DOWN. LOW LEVEL LAPSE RATES FROM THE MODELS ARE
MIXED WITH THEIR RESPECTIVE SOLUTIONS. THE WRF/GFS/ECMWF/SREF SHOW
MARGINALLY STEEP LAPSE RATES ON FRIDAY WHILE THE GEM/UKMET HAVE
QUITE STEEP LOW LEVEL LAPSE RATES. REGARDLESS...IT WILL BE WINDY
WITH GUSTS TO 30 MPH COMMON AND PERHAPS A FEW GUSTS INTO THE MID
30S. SUSTAINED WINDS AND GUSTS ARE EXPECTED TO REMAIN BELOW ADVISORY
CRITERIA SO NO HEADLINE IS EXPECTED.
..08..
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY...
FRIDAY NIGHT THROUGH SATURDAY NIGHT THE MAIN CONCERN IS WITH A STORM
THAT MOVES A SURFACE LOW FROM SOUTHWEST TO NORTHEAST ACROSS IOWA AND
INTO WISCONSIN SATURDAY...MOVING ACROSS THE NORTHWEST CORNER OF THE
CWA. A LARGE FACTOR IN THIS IS THE MOISTURE RETURN THAT WILL BE
BROUGHT INTO THIS SYSTEM. THE GFS IS TYPICALLY TOO AGGRESSIVE WITH
THIS...AND IS PRODUCING LIGHT PRECIPITATION SATURDAY MORNING FROM
WHERE IT SHOULD BE NORTH OF THE FRONT...SMEARED SOUTH ACROSS
IOWA...MISSOURI AND AREAS SOUTH OF THERE YET. THE MOISTURE IS VERY
SHALLOW...LIMITED TO ABOUT 50MB AROUND 850. WHAT USUALLY HAPPENS IN
THIS SITUATION IS STRATUS STREAMS NORTH AHEAD OF THE COLD
FRONT...BUT WE DO NOT GET ANY PRECIPITATION...SO HAVE LEFT THE
FRIDAY NIGHT FORECAST DRY...AND ALL BUT THE NORTHWEST DRY ON
SATURDAY MORNING. AS THE SURFACE LOW ACTUALLY MOVES ACROSS THE AREA
SATURDAY AFTERNOON AND EVENING PRECIPITATION CHANCES LOOK A LITTLE
BETTER...BUT THE BEST LIFT AND MOISTURE CONVERGENCE REMAINS WELL
NORTH OF THE AREA. THE MID LEVEL FRONTOGENESIS BAND WILL STAY WELL
NORTHWEST OF THE REGION...SO AM NOT EXPECTING ANYTHING OVERLY
SIGNIFICANT FOR RAINFALL AMOUNTS IN THIS AREA EITHER. THE STRATUS
SHOULD STREAM INTO THE AREA LATE FRIDAY NIGHT OR EARLY SATURDAY
MORNING...SO OUR MIN TEMPS ARE LIKELY TO OCCUR BETWEEN MIDNIGHT AND
3 AM...BUT THEN RISE ONCE THE STRATUS MOVES IN. THE MID LEVEL FLOW
- AROUND 850MB - SATURDAY AFTERNOON COULD BE AS STRONG AS 50
KTS...BUT WITH THE STRATUS AND THE TEMPERATURE INVERSION
ALOFT KEEPING MIXING DOWN...DO NOT EXPECT STRONGER THAN BREEZY
CONDITIONS AT THE SURFACE TO MATCH WITH THE SURFACE PRESSURE GRADIENT.
HOWEVER...IF WE GET SOME SUNSHINE PEEKING THROUGH...SATURDAY COULD
BE MUCH WINDIER THAN CURRENTLY FORECAST. DESPITE THE CLOUD COVER
THE WINDS WILL ADVECT WARMER TEMPS INTO THE AREA SATURDAY...AND AT
LEAST SOME PEEKS OF SUNSHINE SHOULD ALLOW TEMPS TO GET INTO THE
50S AND LOWER 60S.
SUNDAY AND MONDAY THINGS BECOME QUIET AND COLD AGAIN WITH THE
SURFACE RIDGE BUILDING INTO THE AREA FROM THE NORTHWEST AND BRINGING
MAX TEMPS ONLY IN THE UPPER 30S AND 40S AGAIN. AFTER THE WARMER
TEMPERATURES ON SATURDAY DROPPING BACK INTO THE 30S IS GOING TO BE A
SHOCK- AGAIN.
TUESDAY AND TUESDAY NIGHT THE MODELS DIVERGE SIGNIFICANTLY. THE
ECMWF BRINGS A FAIRLY STRONG SHORTWAVE ACROSS THE SOUTHERN CONUS AS
COMPARED TO THE GFS. BOTH HAVE BEEN RELATIVELY CONSISTENT WITH THIS
SYSTEM...THOUGH THE ECMWF HAS BEEN ADJUSTING HOW FAR NORTH IT BRINGS
THE SYSTEM SOMEWHAT. THUS...HAVE GONE WITH A MIDDLE OF THE ROAD
FORECAST WITH SOME POPS ACROSS THE SOUTH AND COLDER THAN NORMAL
TEMPERATURES...AND WE WILL HAVE TO WAIT ANOTHER DAY OR TWO BEFORE
THE MODELS CONVERGE ON SOMETHING. ..LE..
&&
.AVIATION...
VFR WX WILL BE SEEN THROUGH 00Z/19 AND LIKELY THROUGH 12Z/19 WITH
ONLY MID AND HIGH LEVEL CLOUDS. CURRENT RUC TRENDS SUPPORT A THREAT
OF LLWS STARTING IN THE 04Z-07Z/18 TIME FRAME. A LOW LEVEL JET DVLPS
AFT 00Z/18 AND REACHES PEAK INTENSITY ARND 50 KTS 06Z-12Z/18. LLWS
WITH SHEAR VALUES ARND 30 KTS ARE EXPECTED TO DVLP IN THE 1.8-2.0KFT
AGL LAYER. SOUNDINGS SUGGEST A SUDDEN JUMP IN WIND SPEED IN THE
1.0-1.5KFT AGL LAYER BUT SHEAR VALUES SHOULD REMAIN UNDER 20 KTS.
INVERSION STARTS MIXING OUT AT 15Z/18 WITH LOW LVL TURBULENCE DVLPG.
..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
252 PM EST THU NOV 17 2011
.SYNOPSIS...
EASTBOUND COLD HIGH PRESSURE WILL PROVIDE CLEARING OVERNIGHT AND
SUNSHINE FRIDAY AND SATURDAY. A COLD FRONT, COMING EAST FROM THE
ROCKIES, WILL BRING SOME SHOWERS SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
PER RECENT RADAR, SATELLITE, AND SURFACE DATA AND HRRR MODEL
OUTPUT, EXPECT ISOLATED LIGHT SNOW SHOWERS TO REMAIN CONFINED TO
THE I-80 CORRIDOR AND MOUNTAINS THROUGH EVENING. THEN EXPECT SOME
CLEARING LATE TONIGHT.
NAM MODEL PROFILES SUGGEST SURFACE WINDS CAN GUST TO 30 TO 35
MPH, BEFORE DYING DOWN LATE.
LOWS TONIGHT CAN BE 7 TO 10 DEGREES COLDER THAN NORMAL, PER CONSENSUS
OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
BLEND OF RECENT SREF MODEL OUTPUT CONTINUES TO SHOW EASTBOUND HIGH
PRESSURE WILL PROVIDE DRY CONDITIONS AND MAINLY CLEAR SKIES
FRIDAY AND SATURDAY.
A COLD FRONT, COMING EAST FROM THE ROCKY MOUNTAINS, WILL BRING
SCATTERED SHOWERS THROUGH THE UPPER OHIO VALLEY MAINLY DURING THE DAYTIME
HOURS OF SUNDAY, AS RECENT OPERATIONAL MODELS SUCH AS THE GFS AND
NAM HAVE BEEN A COUPLE HOURS WITH THE ONSET OF THE SHOWERS.
PER RECENT BLEND OF GFS AND NAM MOS, FORECASTED LOWS THURSDAY
NIGHT AND HIGHS FRIDAY TO BE STILL A COUPLE DEGREES COLDER THAN
NORMAL. HIGHS SATURDAY ARE EXPECTED TO MODERATE TO PERHAPS A
COUPLE DEGREES WARMER THAN NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LOWER THAN AVERAGE CONFIDENCE FOR THE EXTENDED FORECAST. ALTHOUGH
THE GFS AND ECMWF AGREE THAT SUNDAY/S COLD FRONT WILL STALL OUT
AFTER MOVING SOUTH OF THE MASON-DIXON LINE...THERE IS DISAGREEMENT
BETWEEN THE MODELS AS TO HOW THE FRONT WILL SHIFT OVER TIME AND
WHETHER ITS INFLUENCE WILL BE FELT NORTH OF THE PA-WV BORDER. AS A
RESULT...HAVE GENERALLY GONE WITH SLIGHT CHANCE POPS TO THE NORTH
AND CHANCE POPS TO THE SOUTH.
BY THE END OF THE PERIOD...THERE IS SOME MODEL CONSENSUS THAT THE
FRONT WILL PUSH OUT TO SEA AND BE REPLACED BY HIGH PRESSURE...
ALTHOUGH THE 00Z ECMWF BRINGS A MUCH STRONGER SYSTEM IN. HPC
STATES THAT THE ECMWF ENSEMBLE SHOWS THE DETERMINISTIC ECMWF
SOLUTION IS UNLIKELY.
INITIAL FORECAST FOR THANKSGIVING...PARTLY CLOUDY...DRY...AND HIGHS
IN THE 40S.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AS BREAKS APPEAR IN MID-LEVEL DECK THIS AFTERNOON...GUSTS UP TO 25
KTS WILL DEVELOP FROM WEST TO EAST. SOME GUIDANCE INDICATES THAT
THESE GUSTS COULD PERSIST INTO THE EVENING...BUT HAVE DECIDED TO END
MENTION OF GUSTS JUST AFTER SUNSET.
HAVE INCLUDED TEMPO FOR AFTERNOON SNOW SHOWERS AT FKL...BUT THINK
THAT MOST SNOW SHOWERS SHOULD REMAIN NORTH OF THE TERMINAL. LOW
CLOUDS MAY REMAIN OVERNIGHT NEAR INTERSTATE 80 AND THE
RIDGES...BUT THINK THAT OTHER LOCATIONS SHOULD CLEAR OUT.
CONDITIONS WILL BE TOO DRY FOR FOG DEVELOPMENT OVERNIGHT.
WINDS WILL SLOWLY BACK TO THE SOUTHWEST OVERNIGHT INTO FRIDAY
MORNING...WITH GUSTS TO 15 KT INCLUDED IN THE 30 HOUR PIT TAF.
OUTLOOK...FRIDAY THROUGH TUESDAY...
HIGH PRESSURE WILL KEEP VFR CONDITIONS IN THE FORECAST THROUGH
SATURDAY NIGHT. BY SUNDAY...A COLD FRONT WILL MOVE IN FROM THE
WEST...BRINGING THE POTENTIAL FOR RESTRICTIONS IN SHOWERS. WITH THE
FRONT STALLING NEAR THE REGION...UNSETTLED WEATHER IS EXPECTED TO
REMAIN POSSIBLE THROUGH TUESDAY.
PER RECENT SURFACE AND SATELLITE DATA, EXPECT VFR COLD-POOL
STRATOCUMULUS TO REMAIN ACROSS THE UPPER OHIO VALLEY INTO EARLY
EVENING. BRIEF MVFR RESTRICTIONS ARE POSSIBLE MAINLY AT KFKL AND
KDUJ DURING THIS AFTERNOON DUE TO SCATTERED LAKE EFFECT SNOW
SHOWERS. SURFACE WINDS CAN GUST TO 25 KTS.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
HIGH PRESSURE WILL BUILD AND PROVIDE VFR TO THE UPPER OHIO REGION
THROUGH SATURDAY. THEREAFTER...THE CHANCE FOR RAIN AND RESTRICTIONS
WILL INCREASE WITH THE APPROACH AND PASSAGE OF ANOTHER COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1152 AM EST THU NOV 17 2011
.SYNOPSIS...
COLD HIGH PRESSURE WILL MOVE ACROSS THE OHIO VALLEY TODAY AND
FRIDAY. ISOLATED LAKE EFFECT SNOW SHOWERS CAN OCCUR ACROSS
NORTHWEST PENNSYLVANIA AND THE APPALACHIAN MOUNTAINS INTO TONIGHT.
EXPECT MORE SUNSHINE FRIDAY AND SATURDAY. A PASSING MIDWEST COLD
FRONT WILL BRING SCATTERED RAIN SHOWERS LATE SATURDAY NIGHT AND SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
PER RECENT RADAR, SATELLITE, AND SURFACE DATA AND HRRR MODEL
OUTPUT, EXPECT MAINLY JUST ISOLATED LIGHT SNOW SHOWERS ACROSS THE
I-80 CORRIDOR AND MOUNTAINS THROUGH TONIGHT. ELSEWHERE MAINLY
SCATTERED CLOUDS THIS AFTERNOON INTO EVENING, WITH CLEARING LATE
TONIGHT.
NAM MODEL PROFILES SUGGEST SURFACE WINDS CAN GUST TO 30
TO 35 MPH.
COLD ADVECTION ALOFT WILL PREVENT TEMPERATURES FROM CLIMBING MUCH THIS
AFTERNOON. LOWS TONIGHT CAN BE 7 TO 10 DEGREES COLDER THAN NORMAL. SPECIFIC
VALUES FORECASTED USING CONSENSUS OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL DOMINATE FRIDAY INTO SATURDAY WITH A DRY
CONDITIONS AND A GRADUAL MODERATING OF TEMPERATURES ESPECIALLY
SATURDAY WHEN HIGHS WILL REACH ABOVE NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
PROGRESSIVE PATTERN IS FORECAST OVER THE GREAT LAKES AND UPPER
OHIO REGIONS FOR THE LONG TERM PERIOD WITH RIDGING OVER THE GULF
AND TROUGHING OVER THE PAC NW/WEST COAST. SHORTWAVES WITHIN THE
FAST FLOW WILL DEFINE THE SENSIBLE WEATHER FOR THE REGION...HENCE
WILL BE DIFFICULT TO TIME.
HAVE RAISED POPS TO LIKELY FOR SUNDAY FOR THE APPROACH AND
PASSAGE OF A COLD FRONT ASSOCIATED WITH LOW PRESSURE PROGGED TO
RACE ACROSS THE GREAT LAKES. THEREAFTER...FORECAST WAS BASED
GFS/ECMWF BLENDED-TIMING OF DISTURBANCES AND HPC TEMPERATURE
GUIDANCE WHICH IS REASONABLY AT...OR SLIGHTLY ABOVE THE SEASONAL
NORMALS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT VFR COLD-POOL STRATOCUMULUS
TO REMAIN ACROSS THE UPPER OHIO VALLEY INTO EARLY EVENING. BRIEF
MVFR RESTRICTIONS ARE POSSIBLE MAINLY AT KFKL AND KDUJ DURING
THIS AFTERNOON DUE TO SCATTERED LAKE EFFECT SNOW SHOWERS. SURFACE
WINDS CAN GUST TO 25 KTS.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
HIGH PRESSURE WILL BUILD AND PROVIDE VFR TO THE UPPER OHIO REGION
THROUGH SATURDAY. THEREAFTER...THE CHANCE FOR RAIN AND RESTRICTIONS
WILL INCREASE WITH THE APPROACH AND PASSAGE OF ANOTHER COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
920 AM EST THU NOV 17 2011
.SYNOPSIS...
COLD HIGH PRESSURE WILL MOVE ACROSS THE OHIO VALLEY TODAY AND
FRIDAY. REMAINING LIGHT SNOW SHOWERS WILL END ACROSS THE MOUNTAINS
BY TONIGHT. EXPECT SUNSHINE FRIDAY AND SATURDAY. A MIDWEST COLD
FRONT WILL PASS THROUGH SUNDAY WITH SCATTERED RAIN SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
PER RECENT RADAR, SATELLITE, AND SURFACE DATA AND HRRR MODEL
OUTPUT, EXPECT MAINLY JUST ISOLATED LIGHT SNOW SHOWERS ACROSS THE
I-80 CORRIDOR AND MOUNTAINS THIS MORNING. WITH PASSAGE OF COLD
UPPER TROUGH THIS AFTERNOON, EXPECT AN INCREASE IN INSTABILITY AND
HENCE COVERAGE OF SHOWERS INTO EARLY EVENING. NAM MODEL PROFILES
SUGGEST SURFACE WINDS CAN GUST TO 30 MPH.
AS DRY AND COLD SURFACE HIGH BUILDS IN TOWARDS THE REGION
TONIGHT, SKIES WILL CLEAR.
NOT MUCH TEMPERATURE RECOVERY EXPECTED TODAY DUE TO THE COLD
ADVECTION. SPECIFIC VALUES FORECASTED USING CONSENSUS OF RECENT
GFS AND NAM MOS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL DOMINATE FRIDAY INTO SATURDAY WITH A DRY
CONDITIONS AND A GRADUAL MODERATING OF TEMPERATURES ESPECIALLY
SATURDAY WHEN HIGHS WILL REACH ABOVE NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
PROGRESSIVE PATTERN IS FORECAST OVER THE GREAT LAKES AND UPPER
OHIO REGIONS FOR THE LONG TERM PERIOD WITH RIDGING OVER THE GULF
AND TROUGHING OVER THE PAC NW/WEST COAST. SHORTWAVES WITHIN THE
FAST FLOW WILL DEFINE THE SENSIBLE WEATHER FOR THE REGION...HENCE
WILL BE DIFFICULT TO TIME.
HAVE RAISED POPS TO LIKELY FOR SUNDAY FOR THE APPROACH AND
PASSAGE OF A COLD FRONT ASSOCIATED WITH LOW PRESSURE PROGGED TO
RACE ACROSS THE GREAT LAKES. THEREAFTER...FORECAST WAS BASED
GFS/ECMWF BLENDED-TIMING OF DISTURBANCES AND HPC TEMPERATURE
GUIDANCE WHICH IS REASONABLY AT...OR SLIGHTLY ABOVE THE SEASONAL
NORMALS.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT VFR COLD-POOL STRATOCUMULUS
TO REMAIN ACROSS THE UPPER OHIO VALLEY INTO EARLY EVENING. BRIEF
MVFR RESTRICTIONS ARE POSSIBLE MAINLY AT KFKL AND KDUJ DURING
THIS AFTERNOON DUE TO SCATTERED LAKE EFFECT SNOW SHOWERS. SURFACE
WINDS CAN GUST TO 25 KTS.
OUTLOOK...THURSDAY NIGHT THROUGH MONDAY...
HIGH PRESSURE WILL BUILD AND PROVIDE VFR TO THE UPPER OHIO REGION
THROUGH SATURDAY. THEREAFTER...THE CHANCE FOR RAIN AND RESTRICTIONS
WILL INCREASE WITH THE APPROACH AND PASSAGE OF ANOTHER COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
315 PM EST THU NOV 17 2011
LATEST UPDATE...ALL BUT AVIATION...
.SYNOPSIS...(315 PM EST THU NOV 17 2011)
THE LAKE EFFECT SNOW SHOWERS WILL GRADUALLY DIMINISH THIS EVENING.
HIGH PRESSURE OVER THE MIDDLE MISSISSIPPI VALLEY WILL STRENGTHEN AS
IT BUILDS EAST INTO THE CENTRAL APPALACHIANS ON FRIDAY. A GUSTY
SOUTHWESTERLY FLOW WILL SETUP HERE IN LOWER MICHIGAN DURING THE DAY
AND PERSIST INTO SATURDAY. A COLD FRONT WILL SLIP SOUTHEASTWARD
THROUGH THE REGION SATURDAY NIGHT PRODUCING SOME RAIN SHOWERS.
COOLER AIR WILL THEN FILTER IN FOR THE REMAINDER OF THE WEEKEND.
&&
.SHORT TERM...(315 PM EST THU NOV 17 2011)
(TONIGHT THROUGH SATURDAY NIGHT)...
THE MAIN CHALLENGE IN THE SHORT TERM DEALS WITH THE WIND GUSTS ON
FRIDAY.
BUFKIT OVERVIEWS SHOW MIXING HEIGHTS TAPPING INTO THE 40
KNOT WIND RANGE ALONG THE LAKESHORE DURING THE DAY ON FRIDAY. ALSO
FSL RUC DATA SUGGESTS WINDS OVER 40 KNOTS MOVING INLAND DURING THE
DAY. PROFILER DATA FROM THE LOWER PLAINS SHOWS THE LOW
LEVEL JET FORMING AND IT IS ALREADY ABOUT 10 KNOTS STRONGER THAN
FORECASTED. WILL ISSUE A WIND ADVISORY FOR FRIDAY FROM 12Z TO 00Z.
MIXING HEIGHTS LOWER DURING THE EVENING AND THAT SHOULD ALLOW FOR
THE WIND TO DECREASE.
THE TIMING OF THE SHOWERS LATER SATURDAY INTO SATURDAY LOOKS GOOD.
I DID DELAY THE SHOWERS SLIGHTLY GIVEN THE SOMEWHAT SLOWER TREND OF
THE FRONTAL PASSAGE. AS A RESULT I TOOK OUT THE MENTION OF SHOWERS
PRIOR TO 18Z SAT.
A DECENT WARMUP IS IN STORE FOR THE REGION ON SATURDAY. LOW LEVEL
THERMAL PROFILES SUPPORT HIGHS TOPPING 50 DEGREES.
&&
.LONG TERM...(315 PM EST THU NOV 17 2011)
(SUNDAY THROUGH THANKSGIVING DAY)
THE LONG TERM PORTION OF THE FCST LOOKS RATHER TRANQUIL...ESPECIALLY
BY MID-LATE NOVEMBER STANDARDS FOR MICHIGAN. WE WILL HAVE TO WATCH A
POSSIBLE SYSTEM THAT COULD STILL IMPACT AT LEAST A PORTION OF THE
AREA TUE INTO TUE NIGHT.
FRONTAL SYSTEM MOVING THROUGH SAT/SAT NIGHT STILL APPEARS TO JUST
CLEAR THE CWFA BY 12Z SUN. DRY NE FLOW AROUND THE INCOMING SFC RIDGE
AND NOT SO COLD TEMPS /H850 TEMPS 0 TO -2C/ WILL BRING QUIET AND
SEASONABLE TEMPS TO THE AREA. WE ARE EXPECTING THIS HIGH TO RULE
ACROSS THE AREA AT LEAST THROUGH MON. FOR NOW...WE ARE DISCOUNTING
THE 12Z GFS BRINGING LIGHT PCPN TO THE AREA. IT SEEMS TO BE TRYING
TO PHASE SRN STREAM MOISTURE WITH A WEAK NRN STREAM TROUGH. THE
SETUP LOOKS OVERDONE WITH MOISTURE THIS FAR NORTH AND NOT FAVORABLE
FOR PCPN ON MON FOR NOW.
THE TRENDS IN THE MODELS ARE TO HAVE THE SYSTEM FOR TUE/WED A LITTLE
FURTHER NORTH THAN WAS EXPECTED 24 HOURS AGO. WE CAN NOT DISCOUNT
THIS IDEA EXPECTING IT MAY BE A LITTLE STRONGER THAN WHAT IS BEING
SAMPLED NOW. HOWEVER UNLESS THERE IS GOOD PHASING BETWEEN THE TWO
STREAMS...IT SHOULD CONTINUE TO MAINLY MISS THE AREA. THE 00Z EURO
WAS QUITE THE OUTLIER WITH A CLOSED NRN STREAM LOW PHASING WITH THE
SRN STREAM...AND BRINGING A LOT OF PCPN TO THE AREA TUE/WED. THE NEW
EURO HAS BACKED AWAY FROM THAT THINKING...AND IS CLOSER TO THE
ENSEMBLES. IN COORDINATION WITH SURROUNDING OFFICES...WE HAVE ADDED
A SMALL CHC OF PCPN TUE AND TUE NIGHT DOWN SOUTH FOR NOW...AND WILL
CONTINUE TO MONITOR THE TRENDS.
ALL OF THE MODELS HAVE A FAIRLY GOOD RIDGE THEN BUILDING OVER THE
AREA FOR WED AND THANKSGIVING DAY AS ANOTHER STRONG TROUGH TAKES
SHAPE ALONG THE WEST COAST. THIS SHOULD ALLOW FOR MORE SEASONABLE TO
SLIGHTLY ABOVE AVERAGE TEMPS FOR NOVEMBER ALONG WITH DRY CONDITIONS
FOR THE FIRST PART OF THE HOLIDAY TRAVEL PERIOD FOR MICHIGAN.
&&
.AVIATION...(1245 PM EST THU NOV 17 2011)
LAKE EFFECT TRENDS AND GUSTY WINDS ARE THE MAIN ITEMS OF INTEREST
WITH THIS SET OF FCSTS.
LAKE EFFECT FLURRIES/SNOW SHOWERS ARE AFFECTING MOST OF THE AREA
EARLY THIS AFTERNOON...HOWEVER THE IMPACTS ARE NOT SIGNIFICANT. MOST
OF THE CIGS AND VSBYS ARE REMAINING VFR WITH SOME ISOLATED MVFR
PRESENT. THE BEST SNOW SHOWERS ARE ACTUALLY DISPLACED INLAND
SOME...LIKELY DUE TO SOME DIURNAL ENHANCEMENT. CONDITIONS ARE
EXPECTED TO BEGIN TO IMPROVE IN THE NEXT 2-4 HOURS AS THE UPPER WAVE
BEGINS TO MOVE AWAY. GUSTS TO 25 KNOTS THIS AFTERNOON WILL DIMINISH
AROUND 23-01Z.
LAKE CLOUDS WILL LIKELY HANG ON THROUGH A GOOD PORTION OF THE
EVENING. RIDGING TAKES HOLD LATE THIS EVENING...AND A SURGE OF EVEN
DRIER AIR MOVES IN AT THAT TIME. CLOUDS WILL LIKELY DISSIPATE ACROSS
THE FAR EAST FIRST...AND WRN SITES WILL BE LAST TO CLEAR OUT DUE TO
THE PROXIMITY OF THE LAKE.
ONLY MID CLOUDS ARE EXPECTED THEN LATE TONIGHT AND ON FRI. WINDS
WILL PICK UP PRIOR TO DAYBREAK AT KMKG WITH BETTER MIXING OFF OF THE
LAKE. WINDS WILL INCREASE SOME AT KAZO AND KGRR PRIOR TO DAYBREAK.
SUSTAINED WINDS OF 20-25 KNOTS ARE LIKELY...WITH GUSTS TO 35 KNOTS
AS DIURNAL MIXING TAKES PLACE. SOME GUSTS TO 40 KNOTS ARE NOT OUT OF
THE QUESTION..
&&
.MARINE...(315 PM EST THU NOV 17 2011)
THE ARRIVAL OF A LOW LEVEL JET COUPLED WITH INCREASED MIXING ON
FRIDAY SUPPORTS KEEPING THE GALE WARNING FOR FRIDAY. MIXING
HEIGHTS SUGGEST THE NEARSHORE ZONES WILL REACH INTO THE 40 KNOT
RANGE OF WINDS FRIDAY. THE LOW LEVEL JET AND INCREASED MIXING
PERSISTS THROUGH 00Z SAT...THUS I WILL KEEP THE WARNING GOING
THROUGH MUCH OF THE NIGHT.
&&
.HYDROLOGY...(315 PM EST WED NOV 16 2011)
ANY QPF THROUGH THE PERIOD IS FORECASTED TO BE RELATIVELY LIGHT. AS
A RESULT... NO HYDRO ISSUES ANTICIPATED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY FOR THE LAKESHORE COUNTIES FRIDAY.
LM...SMALL CRAFT ADVISORY ALL NEARSHORE ZONES THROUGH TONIGHT.
GALE WARNING FRIDAY INTO FRIDAY NIGHT ALL NEARSHORE ZONES.
&&
$$
SYNOPSIS: MJS
SHORT TERM: MJS
LONG TERM: NJJ
AVIATION: NJJ
MARINE: MJS
HYDROLOGY: MJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1240 PM EST THU NOV 17 2011
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM
HUDSON BAY S THRU THE MISSISSIPPI VALLEY. WELL UPSTREAM...A DEEP
MIDLEVEL LOW IS DROPPING DOWN THE BRITISH COLUMBIA COAST. OVER THE
NEXT COUPLE OF DAYS...THIS SYSTEM WILL AID TROF DEVELOPMENT OVER THE
WRN CONUS...RESULTING IN DOWNSTREAM FLOW BECOMING SW INTO THE GREAT
LAKES. CLOSER TO HOME...A SHORTWAVE IS SLOWLY MOVING ACROSS UPPER MI
ATTM...SUPPORTING INCREASING LES INTENSITY. JUST UPSTREAM...00Z KINL
SOUNDING SHOWED A FAVORABLE PROFILE FOR LES WITH DEEP MOISTURE UP TO
700MB AND 850MB TEMP OF -15C...RIGHT IN THE MIDDLE OF THE FAVORABLE
TEMP ZONE FOR DENDRITES. CANADIAN RADAR IMAGERY EARLIER IN THE NIGHT
SHOWED A VERY IMPRESSIVE DOMINANT BAND EXTENDING FROM LAKE NIPIGON
DOWN THE ERN SHORE OF LAKE SUPERIOR WHERE N/NE LAND BREEZE OFF
ONTARIO CONVERGED WITH STRONG W FLOW OVER THE LAKE. THAT BAND HAS
GIVEN WAY TO SEVERAL INTENSE SNOW BANDS OVER THE LAKE...AND RADAR
IMAGERY ALMOST SUGGESTS A MESO LOW DEVELOPING NE OF CARIBOU ISLAND.
CONVECTION IS DEEP AS KMQT RADAR CONTINUES TO INDICATE CLOUD TOPS
AROUND 20K FT. OVER THE W...AT LEAST A COUPLE OF DOMINANT BANDS HAVE
BEEN AFFECTING WRN UPPER MI. LAND BREEZE OFF NW WI HAS BEEN
SUPPORTING ONE BAND INTO THE AREA AROUND THE PORCUPINE MOUNTAINS E
TO BERGLAND PER KDLH RADAR. PUBLIC REPORT EARLIER IN THE NIGHT
INDICATED 3 INCHES OF SNOW...AND WEBCAM SUGGESTS POSSIBLY A FEW MORE
INCHES SINCE THEN. ANOTHER DOMINANT BAND HAD BEEN AFFECTING THE AREA
AROUND THE HOUGHTON COUNTY AIRPORT. AWAY FROM W WIND LES...
CLEAR/PARTLY CLOUDY SKIES HAVE BEEN THE RULE ACROSS MUCH OF THE
DOWNSLOPE AREAS OF THE CNTRL INTO ERN FCST AREA DURING THE NIGHT.
&&
.DISCUSSION...
LES SHOULD CONTINUE TO INCREASE OVER THE NEXT SEVERAL HRS GIVEN THE
FAVORABLE AIR MASS PROPERTIES AS INDICATED BY THE 00Z KINL SOUNDING.
SNOW RATES MAY BECOME FAIRLY IMPRESSIVE FOR A WHILE DURING THE
MORNING HRS...AND WILL NEED TO MONITOR FOR POSSIBLE SHORT TERM
UPGRADE OF ADVY TO WARNING OVER SOME PORTION OF THE W IF LOW-LEVEL
CONVERGENCE REMAINS FOCUSED AT ANY ONE LOCATION. TYPICALLY IN W WIND
REGIMES...LAND BREEZE OFF NW WI FORCES CONVERGENCE INTO AN AREA OF
FAR NRN ONTONAGON INTO ADJACENT HOUGHTON COUNTY...OFTEN AROUND TWIN
LAKES. HIGHER RES GUIDANCE SUGGESTS CONVERGENCE WILL REMAIN SET UP A
BIT FARTHER S AS HAS BEEN OCCURRING DURING THE NIGHT FROM THE
PORCUPINE MOUNTAINS TO BERGLAND. REGIONAL GEM AND ESPECIALLY THE
HIRES WRF-ARW HAVE DONE WELL DEPICTING SOME OF THE ACTIVITY OVER THE
WRN U.P. WILL THUS PAINT HIGHEST SNOW TOTALS IN ONTONAGON COUNTY AND
HOUGHTON COUNTY S OF TWIN LAKES. WILL PROBABLY FLIRT WITH 12HR-24HR
WARNING CRITERIA IN A FEW HIGHER TERRAIN LOCATIONS WHERE THE BEST
CONVERGENCE REMAINS NEARLY STATIONARY. TO THE E...W FLOW SO FAR
DURING THE NIGHT HAS KEPT MUCH OF THE LES OFFSHORE OF ERN ALGER/NRN
LUCE. LATEST RADAR TRENDS SHOW INCREASING LES INTENSITY/ORGANIZATION
OVER ERN LAKE SUPERIOR. AS WINDS VEER SLIGHTLY WITH PASSING
SHORTWAVE...ENHANCED CONVERGENCE ZONE SHOULD SHIFT S INTO NE
ALGER/NRN LUCE THIS MORNING. FAVORABLE INSTABILITY/MOISTURE AND
ONGOING HVY SNOW OVER NE/E LAKE SUPERIOR INDICATE POTENTIAL FOR
SIGNIFICANT LES OVER THE NEXT 12HRS. INTERESTING TO NOTE THAT THE
REGIONAL GEM REALLY ENHANCES THE N/NE LAND BREEZE OFF ONTARIO BEHIND
PASSING SHORTWAVE...ENOUGH SO THAT A LAKE NIPIGON ENHANCED HVY SNOW
BAND SHIFTS SW ALL THE WAY TO PICTURED ROCKS. HIGH RES WRF-ARW AND
LOCAL HIGH RES WRF HAVE A SIMILAR SCENARIO...BUT ONLY PUSH
CONVERGENCE ZONE AS FAR SW AS LUCE COUNTY TO POSSIBLY GRAND MARAIS.
STRONGLY FOCUSED CONVERGENCE/LAKE NIPIGON PRECONDITONING AND DEEP
CONVECTIVE/MOIST LAYER (KMQT RADAR INDICATES CLOUD TOPS TO 20K FT)
POINT TO INTENSE SNOWFALL RATES WHEN BANDS SHIFT SW INTO LUCE/NE
ALGER COUNTY. AT THIS POINT...LUCE COUNTY IS MOST LIKELY TO FALL
UNDER THE HEAVIER SNOW...SO WARNING LOOKS ON TRACK THERE. THERE IS
MORE UNCERTAINTY FOR ALGER SINCE BULK OF GUIDANCE DOES NOT SHIFT
CONVERGENCE ZONE AS FAR SW AS REGIONAL GEM/LOCAL HIGH RES WRF. FOR
NOW...WILL LEAVE ADVY FOR ALGER...BUT TRENDS WILL NEED TO MONITORED
CLOSELY THIS MORNING. AWAY FROM LES...EXPECT PARTLY TO MOSTLY CLOUDY
SKIES TODAY...THOUGH WHERE W WIND DOWNSLOPING IS MAXIMIZED IN CNTRL
UPPER MI...THERE MAY BE QUITE A BIT OF SUN THRU THE DAY.
LOW-LEVEL WINDS WILL BEGIN TO BACK LATE AFTN AND THRU TONIGHT...
SHIFTING LES N AND EVENTUALLY OUT OF UPPER MI. LAST OF THE LES
SHOULD PROBABLY EXIT UPPER MI AROUND 06Z TONIGHT. AHEAD OF THE
AMPLIFYING WRN CONUS TROF...A SHORTWAVE WILL STREAK E ALONG
U.S./CANADA BORDER TONIGHT/FRI. WAA REGIME AHEAD OF THE WAVE WILL
ALREADY BE SPREADING INTO THE UPPER GREAT LAKES OVERNIGHT. THERE
REMAINS UNCERTAINTY IN HOW FAR S SATURATION WILL OCCUR IN THE
WAA/STRONG ISENTROPIC REGIME. GIVEN THE STRENGTH OF ASCENT...AT
LEAST LOW POPS ACROSS THE N SEEM REASONABLE. AS WINDS BACK ACROSS
LAKE MICHIGAN...ADDITIONAL LOW-LEVEL MOISTENING SUPPORTS EXTENDING
POPS S ACROSS THE ERN FCST AREA AS WELL.
COLD FRONT ASSOCIATED WITH WAVE WILL DRIFT SE INTO UPPER MI FRI
NIGHT/EARLY SAT AND THEN BECOME STATIONARY AS SHORTWAVE EJECTS FROM
WRN TROF. MODELS CONTINUE TO SHOW GOOD CONTINUITY ON THIS SYSTEM. IF
ANYTHING...THERE APPEARS TO BE A SLIGHT OVERALL MODEL TREND TOWARD A
WEAKER/FLATTER WAVE OVER THE LAST SEVERAL MODEL RUNS. CLUSTERING OF
GUIDANCE IS GOOD WITH ALL INDICATING VERY SIMILAR TRACKS FROM KS
TO THE STRAITS AREA. SINCE SYSTEM WILL BE RELATIVELY FLAT/FAST
MOVING...THIS WILL MOST LIKELY BE AN ADVY TYPE SNOW EVENT SAT
AFTN/NIGHT OVER MUCH OF W AND CNTRL UPPER MI. RAIN/SNOW SHOULD
AFFECT MAINLY THE SCNTRL/SE FCST AREA. GLOBAL GEM HAS THE HEAVIEST
PCPN WITH TOTALS IN THE 0.75 TO 1 INCH RANGE ACROSS SCNTRL UPPER MI.
GFS/ECMWF MAX OUT AROUND A HALF INCH...THOUGH 00Z ECMWF HAS TRENDED
LESS. THERE WILL PROBABLY BE A BRIEF PERIOD OF LAKE ENHANCED SNOW
ACROSS THE W AND NCNTRL AS SYSTEM PASSES...LEADING TO GREATEST SNOW
ACCUMULATIONS IN THOSE AREAS.
A GENERALLY QUIET PERIOD OF WEATHER IS EXPECTED AFTER THE WEEKEND
SYSTEM. POLAR VORTEX SETTLING FROM THE NPOLE TO ALASKA WILL RESULT
IN INCREASING PACIFIC FLOW ACROSS THE CONUS...SPELLING A WARMING
TREND HERE NEXT WEEK. COULD BE UNSEASONABLY WARM BY THANKSGIVING AS
TROF SWINGING INTO THE WRN CONUS BACKS FLOW SW INTO THE GREAT LAKES.
ECMWF/GFS SHOW 850MB TEMPS PUSHING 8C FOR THANKSGIVING UNDER DRY
AIRMASS...SO IT COULD BE QUITE WARM FOR LATE NOV.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
COLD AIR MOVING ACROSS LAKE SUPERIOR WILL PRODUCE CLOUDS AND LAKE
EFFECT SNOW FOR THE WEST TO NORTHWEST WIND SNOW BELTS TODAY. THIS
WILL LARGELY AFFECT KCMX WITH MAINLY MVFR CIGS/VSBY. HEAVY SNOW
SHOWERS THAT FELL AT KCMX OVERNIGHT HAVE SHIFTED SOUTH OF THE
AIRPORT AS WINDS HAVE BECOME NORTHWEST. GOOD CHANCE THAT AS WINDS
BECOME WESTERLY THIS AFTERNOON COULD SEE ANOTHER ROUND OF HEAVIER
SNOW SHOWERS...BEFORE THE LK EFFECT SHUTS OFF AS WINDS BECOME
SOUTHWEST BY THE EVENING. WENT FOR IFR VSBY THIS AFTN...BUT
CONDITIONS MAY BRIEFLY FALL TO NEAR AIRPORT MINS IN THE HEAVIEST
SNOW SHOWERS.
SOME RISK THAT SOME SNOW SHOWERS MAY WORK INTO KIWD UNTIL WINDS
BECOME MORE SW LATER THIS AFTN. ONLY FLURRIES/MVFR CONDITIONS ARE
EXPECTED. VFR CONDITIONS CONTINUE FOR KSAW AS WRLY WINDS ARE NOT
FAVORABLE FOR ANY LK EFFECT.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
A WEAK TROUGH HANGS ON ACROSS EASTERN LK SUPERIOR MUCH OF TODAY WITH
A CONTINUED POTENTIAL FOR MARGINAL GALE GUSTS OVER SOUTH CENTRAL LK
SUPERIOR. WINDS SLIGHTLY DIMINISH LATER TONIGHT INTO FRIDAY AS WEAK
RIDGE TONIGHT IS FOLLOWED BY A WEST-TO-EAST ORIENTED TROUGH BY
FRIDAY AFTN. SINCE THE TROUGH IS MORE OVER THE LAKE INSTEAD OF TO
THE THE NORTH...WHICH LIMITS PRESSURE FALLS TO ENHANCE STRONGER
WINDS...GALE POTENTIAL FOR FRIDAY HAS LESSENED. LOW PRESSURE OVER
THE PLAINS STILL ON TRACK TO LIFT ACROSS UPR LAKES SATURDAY AFTN AND
SATURDAY EVENING. MODELS HAVE TRENDED WEAKER OVER TIME WITH THE LOW
AND WINDS. UNLESS THERE A FCST OF A DEEPER SYSTEM RETURNS...SEEMS
THERE IS ONLY A LOW RISK OF NORTHERLY GALES WITH THE SYSTEM. HIGH
PRESSURE BUILDS BACK IN FOR EARLY NEXT WEEK...LEADING TO LIGHTER
WINDS BY THAT TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
MIZ001>003-006-084.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...ROLFSON
DISCUSSION...ROLFSON
AVIATION...TITUS
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
654 AM EST THU NOV 17 2011
UPDATED AVIATION DISCUSSION FOR 12Z TAFS
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM
HUDSON BAY S THRU THE MISSISSIPPI VALLEY. WELL UPSTREAM...A DEEP
MIDLEVEL LOW IS DROPPING DOWN THE BRITISH COLUMBIA COAST. OVER THE
NEXT COUPLE OF DAYS...THIS SYSTEM WILL AID TROF DEVELOPMENT OVER THE
WRN CONUS...RESULTING IN DOWNSTREAM FLOW BECOMING SW INTO THE GREAT
LAKES. CLOSER TO HOME...A SHORTWAVE IS SLOWLY MOVING ACROSS UPPER MI
ATTM...SUPPORTING INCREASING LES INTENSITY. JUST UPSTREAM...00Z KINL
SOUNDING SHOWED A FAVORABLE PROFILE FOR LES WITH DEEP MOISTURE UP TO
700MB AND 850MB TEMP OF -15C...RIGHT IN THE MIDDLE OF THE FAVORABLE
TEMP ZONE FOR DENDRITES. CANADIAN RADAR IMAGERY EARLIER IN THE NIGHT
SHOWED A VERY IMPRESSIVE DOMINANT BAND EXTENDING FROM LAKE NIPIGON
DOWN THE ERN SHORE OF LAKE SUPERIOR WHERE N/NE LAND BREEZE OFF
ONTARIO CONVERGED WITH STRONG W FLOW OVER THE LAKE. THAT BAND HAS
GIVEN WAY TO SEVERAL INTENSE SNOW BANDS OVER THE LAKE...AND RADAR
IMAGERY ALMOST SUGGESTS A MESO LOW DEVELOPING NE OF CARIBOU ISLAND.
CONVECTION IS DEEP AS KMQT RADAR CONTINUES TO INDICATE CLOUD TOPS
AROUND 20K FT. OVER THE W...AT LEAST A COUPLE OF DOMINANT BANDS HAVE
BEEN AFFECTING WRN UPPER MI. LAND BREEZE OFF NW WI HAS BEEN
SUPPORTING ONE BAND INTO THE AREA AROUND THE PORCUPINE MOUNTAINS E
TO BERGLAND PER KDLH RADAR. PUBLIC REPORT EARLIER IN THE NIGHT
INDICATED 3 INCHES OF SNOW...AND WEBCAM SUGGESTS POSSIBLY A FEW MORE
INCHES SINCE THEN. ANOTHER DOMINANT BAND HAD BEEN AFFECTING THE AREA
AROUND THE HOUGHTON COUNTY AIRPORT. AWAY FROM W WIND LES...
CLEAR/PARTLY CLOUDY SKIES HAVE BEEN THE RULE ACROSS MUCH OF THE
DOWNSLOPE AREAS OF THE CNTRL INTO ERN FCST AREA DURING THE NIGHT.
&&
.DISCUSSION...
LES SHOULD CONTINUE TO INCREASE OVER THE NEXT SEVERAL HRS GIVEN THE
FAVORABLE AIR MASS PROPERTIES AS INDICATED BY THE 00Z KINL SOUNDING.
SNOW RATES MAY BECOME FAIRLY IMPRESSIVE FOR A WHILE DURING THE
MORNING HRS...AND WILL NEED TO MONITOR FOR POSSIBLE SHORT TERM
UPGRADE OF ADVY TO WARNING OVER SOME PORTION OF THE W IF LOW-LEVEL
CONVERGENCE REMAINS FOCUSED AT ANY ONE LOCATION. TYPICALLY IN W WIND
REGIMES...LAND BREEZE OFF NW WI FORCES CONVERGENCE INTO AN AREA OF
FAR NRN ONTONAGON INTO ADJACENT HOUGHTON COUNTY...OFTEN AROUND TWIN
LAKES. HIGHER RES GUIDANCE SUGGESTS CONVERGENCE WILL REMAIN SET UP A
BIT FARTHER S AS HAS BEEN OCCURRING DURING THE NIGHT FROM THE
PORCUPINE MOUNTAINS TO BERGLAND. REGIONAL GEM AND ESPECIALLY THE
HIRES WRF-ARW HAVE DONE WELL DEPICTING SOME OF THE ACTIVITY OVER THE
WRN U.P. WILL THUS PAINT HIGHEST SNOW TOTALS IN ONTONAGON COUNTY AND
HOUGHTON COUNTY S OF TWIN LAKES. WILL PROBABLY FLIRT WITH 12HR-24HR
WARNING CRITERIA IN A FEW HIGHER TERRAIN LOCATIONS WHERE THE BEST
CONVERGENCE REMAINS NEARLY STATIONARY. TO THE E...W FLOW SO FAR
DURING THE NIGHT HAS KEPT MUCH OF THE LES OFFSHORE OF ERN ALGER/NRN
LUCE. LATEST RADAR TRENDS SHOW INCREASING LES INTENSITY/ORGANIZATION
OVER ERN LAKE SUPERIOR. AS WINDS VEER SLIGHTLY WITH PASSING
SHORTWAVE...ENHANCED CONVERGENCE ZONE SHOULD SHIFT S INTO NE
ALGER/NRN LUCE THIS MORNING. FAVORABLE INSTABILITY/MOISTURE AND
ONGOING HVY SNOW OVER NE/E LAKE SUPERIOR INDICATE POTENTIAL FOR
SIGNIFICANT LES OVER THE NEXT 12HRS. INTERESTING TO NOTE THAT THE
REGIONAL GEM REALLY ENHANCES THE N/NE LAND BREEZE OFF ONTARIO BEHIND
PASSING SHORTWAVE...ENOUGH SO THAT A LAKE NIPIGON ENHANCED HVY SNOW
BAND SHIFTS SW ALL THE WAY TO PICTURED ROCKS. HIGH RES WRF-ARW AND
LOCAL HIGH RES WRF HAVE A SIMILAR SCENARIO...BUT ONLY PUSH
CONVERGENCE ZONE AS FAR SW AS LUCE COUNTY TO POSSIBLY GRAND MARAIS.
STRONGLY FOCUSED CONVERGENCE/LAKE NIPIGON PRECONDITONING AND DEEP
CONVECTIVE/MOIST LAYER (KMQT RADAR INDICATES CLOUD TOPS TO 20K FT)
POINT TO INTENSE SNOWFALL RATES WHEN BANDS SHIFT SW INTO LUCE/NE
ALGER COUNTY. AT THIS POINT...LUCE COUNTY IS MOST LIKELY TO FALL
UNDER THE HEAVIER SNOW...SO WARNING LOOKS ON TRACK THERE. THERE IS
MORE UNCERTAINTY FOR ALGER SINCE BULK OF GUIDANCE DOES NOT SHIFT
CONVERGENCE ZONE AS FAR SW AS REGIONAL GEM/LOCAL HIGH RES WRF. FOR
NOW...WILL LEAVE ADVY FOR ALGER...BUT TRENDS WILL NEED TO MONITORED
CLOSELY THIS MORNING. AWAY FROM LES...EXPECT PARTLY TO MOSTLY CLOUDY
SKIES TODAY...THOUGH WHERE W WIND DOWNSLOPING IS MAXIMIZED IN CNTRL
UPPER MI...THERE MAY BE QUITE A BIT OF SUN THRU THE DAY.
LOW-LEVEL WINDS WILL BEGIN TO BACK LATE AFTN AND THRU TONIGHT...
SHIFTING LES N AND EVENTUALLY OUT OF UPPER MI. LAST OF THE LES
SHOULD PROBABLY EXIT UPPER MI AROUND 06Z TONIGHT. AHEAD OF THE
AMPLIFYING WRN CONUS TROF...A SHORTWAVE WILL STREAK E ALONG
U.S./CANADA BORDER TONIGHT/FRI. WAA REGIME AHEAD OF THE WAVE WILL
ALREADY BE SPREADING INTO THE UPPER GREAT LAKES OVERNIGHT. THERE
REMAINS UNCERTAINTY IN HOW FAR S SATURATION WILL OCCUR IN THE
WAA/STRONG ISENTROPIC REGIME. GIVEN THE STRENGTH OF ASCENT...AT
LEAST LOW POPS ACROSS THE N SEEM REASONABLE. AS WINDS BACK ACROSS
LAKE MICHIGAN...ADDITIONAL LOW-LEVEL MOISTENING SUPPORTS EXTENDING
POPS S ACROSS THE ERN FCST AREA AS WELL.
COLD FRONT ASSOCIATED WITH WAVE WILL DRIFT SE INTO UPPER MI FRI
NIGHT/EARLY SAT AND THEN BECOME STATIONARY AS SHORTWAVE EJECTS FROM
WRN TROF. MODELS CONTINUE TO SHOW GOOD CONTINUITY ON THIS SYSTEM. IF
ANYTHING...THERE APPEARS TO BE A SLIGHT OVERALL MODEL TREND TOWARD A
WEAKER/FLATTER WAVE OVER THE LAST SEVERAL MODEL RUNS. CLUSTERING OF
GUIDANCE IS GOOD WITH ALL INDICATING VERY SIMILAR TRACKS FROM KS
TO THE STRAITS AREA. SINCE SYSTEM WILL BE RELATIVELY FLAT/FAST
MOVING...THIS WILL MOST LIKELY BE AN ADVY TYPE SNOW EVENT SAT
AFTN/NIGHT OVER MUCH OF W AND CNTRL UPPER MI. RAIN/SNOW SHOULD
AFFECT MAINLY THE SCNTRL/SE FCST AREA. GLOBAL GEM HAS THE HEAVIEST
PCPN WITH TOTALS IN THE 0.75 TO 1 INCH RANGE ACROSS SCNTRL UPPER MI.
GFS/ECMWF MAX OUT AROUND A HALF INCH...THOUGH 00Z ECMWF HAS TRENDED
LESS. THERE WILL PROBABLY BE A BRIEF PERIOD OF LAKE ENHANCED SNOW
ACROSS THE W AND NCNTRL AS SYSTEM PASSES...LEADING TO GREATEST SNOW
ACCUMULATIONS IN THOSE AREAS.
A GENERALLY QUIET PERIOD OF WEATHER IS EXPECTED AFTER THE WEEKEND
SYSTEM. POLAR VORTEX SETTLING FROM THE NPOLE TO ALASKA WILL RESULT
IN INCREASING PACIFIC FLOW ACROSS THE CONUS...SPELLING A WARMING
TREND HERE NEXT WEEK. COULD BE UNSEASONABLY WARM BY THANKSGIVING AS
TROF SWINGING INTO THE WRN CONUS BACKS FLOW SW INTO THE GREAT LAKES.
ECMWF/GFS SHOW 850MB TEMPS PUSHING 8C FOR THANKSGIVING UNDER DRY
AIRMASS...SO IT COULD BE QUITE WARM FOR LATE NOV.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
COLD AIR MOVING ACROSS LAKE SUPERIOR WILL PRODUCE CLOUDS AND LAKE
EFFECT SNOW FOR THE WEST TO NORTHWEST WIND SNOW BELTS TODAY. THIS
WILL LARGELY AFFECT KCMX WITH MAINLY MVFR CIGS/VSBY. HEAVY SNOW
SHOWERS THAT FELL AT KCMX OVERNIGHT HAVE SHIFTED SOUTH OF THE
AIRPORT AS WINDS HAVE BECOME NORTHWEST. GOOD CHANCE THAT AS WINDS
BECOME WESTERLY TODAY COULD SEE ANOTHER ROUND OF HEAVIER SNOW
SHOWERS...BEFORE THE LK EFFECT SHUTS OFF AS WINDS BECOME SOUTHWEST
BY THE EVENING. WENT FOR IFR VSBY IN THE AFTN...BUT CONDITIONS MAY
BRIEFLY FALL TO NEAR AIRPORT MINS IN THE HEAVIEST SNOW SHOWERS.
SOME RISK THAT SOME SNOW SHOWERS MAY WORK INTO KIWD UNTIL WINDS
BECOME MORE SW THIS AFTN. ONLY FLURRIES/MVFR CONDITIONS ARE
EXPECTED. VFR CONDITIONS CONTINUE FOR KSAW AS WRLY WINDS ARE NOT
FAVORABLE FOR ANY LK EFFECT.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
A WEAK TROUGH HANGS ON ACROSS EASTERN LK SUPERIOR MUCH OF TODAY WITH
A CONTINUED POTENTIAL FOR MARGINAL GALE GUSTS OVER SOUTH CENTRAL LK
SUPERIOR. WINDS SLIGHTLY DIMINISH LATER TONIGHT INTO FRIDAY AS WEAK
RIDGE TONIGHT IS FOLLOWED BY A WEST-TO-EAST ORIENTED TROUGH BY
FRIDAY AFTN. SINCE THE TROUGH IS MORE OVER THE LAKE INSTEAD OF TO
THE THE NORTH...WHICH LIMITS PRESSURE FALLS TO ENHANCE STRONGER
WINDS...GALE POTENTIAL FOR FRIDAY HAS LESSENED. LOW PRESSURE OVER
THE PLAINS STILL ON TRACK TO LIFT ACROSS UPR LAKES SATURDAY AFTN AND
SATURDAY EVENING. MODELS HAVE TRENDED WEAKER OVER TIME WITH THE LOW
AND WINDS. UNLESS THERE A FCST OF A DEEPER SYSTEM RETURNS...SEEMS
THERE IS ONLY A LOW RISK OF NORTHERLY GALES WITH THE SYSTEM. HIGH
PRESSURE BUILDS BACK IN FOR EARLY NEXT WEEK...LEADING TO LIGHTER
WINDS BY THAT TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
MIZ001>003-006-084.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...ROLFSON
DISCUSSION...ROLFSON
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
548 AM EST THU NOV 17 2011
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM
HUDSON BAY S THRU THE MISSISSIPPI VALLEY. WELL UPSTREAM...A DEEP
MIDLEVEL LOW IS DROPPING DOWN THE BRITISH COLUMBIA COAST. OVER THE
NEXT COUPLE OF DAYS...THIS SYSTEM WILL AID TROF DEVELOPMENT OVER THE
WRN CONUS...RESULTING IN DOWNSTREAM FLOW BECOMING SW INTO THE GREAT
LAKES. CLOSER TO HOME...A SHORTWAVE IS SLOWLY MOVING ACROSS UPPER MI
ATTM...SUPPORTING INCREASING LES INTENSITY. JUST UPSTREAM...00Z KINL
SOUNDING SHOWED A FAVORABLE PROFILE FOR LES WITH DEEP MOISTURE UP TO
700MB AND 850MB TEMP OF -15C...RIGHT IN THE MIDDLE OF THE FAVORABLE
TEMP ZONE FOR DENDRITES. CANADIAN RADAR IMAGERY EARLIER IN THE NIGHT
SHOWED A VERY IMPRESSIVE DOMINANT BAND EXTENDING FROM LAKE NIPIGON
DOWN THE ERN SHORE OF LAKE SUPERIOR WHERE N/NE LAND BREEZE OFF
ONTARIO CONVERGED WITH STRONG W FLOW OVER THE LAKE. THAT BAND HAS
GIVEN WAY TO SEVERAL INTENSE SNOW BANDS OVER THE LAKE...AND RADAR
IMAGERY ALMOST SUGGESTS A MESO LOW DEVELOPING NE OF CARIBOU ISLAND.
CONVECTION IS DEEP AS KMQT RADAR CONTINUES TO INDICATE CLOUD TOPS
AROUND 20K FT. OVER THE W...AT LEAST A COUPLE OF DOMINANT BANDS HAVE
BEEN AFFECTING WRN UPPER MI. LAND BREEZE OFF NW WI HAS BEEN
SUPPORTING ONE BAND INTO THE AREA AROUND THE PORCUPINE MOUNTAINS E
TO BERGLAND PER KDLH RADAR. PUBLIC REPORT EARLIER IN THE NIGHT
INDICATED 3 INCHES OF SNOW...AND WEBCAM SUGGESTS POSSIBLY A FEW MORE
INCHES SINCE THEN. ANOTHER DOMINANT BAND HAD BEEN AFFECTING THE AREA
AROUND THE HOUGHTON COUNTY AIRPORT. AWAY FROM W WIND LES...
CLEAR/PARTLY CLOUDY SKIES HAVE BEEN THE RULE ACROSS MUCH OF THE
DOWNSLOPE AREAS OF THE CNTRL INTO ERN FCST AREA DURING THE NIGHT.
&&
.DISCUSSION...
LES SHOULD CONTINUE TO INCREASE OVER THE NEXT SEVERAL HRS GIVEN THE
FAVORABLE AIR MASS PROPERTIES AS INDICATED BY THE 00Z KINL SOUNDING.
SNOW RATES MAY BECOME FAIRLY IMPRESSIVE FOR A WHILE DURING THE
MORNING HRS...AND WILL NEED TO MONITOR FOR POSSIBLE SHORT TERM
UPGRADE OF ADVY TO WARNING OVER SOME PORTION OF THE W IF LOW-LEVEL
CONVERGENCE REMAINS FOCUSED AT ANY ONE LOCATION. TYPICALLY IN W WIND
REGIMES...LAND BREEZE OFF NW WI FORCES CONVERGENCE INTO AN AREA OF
FAR NRN ONTONAGON INTO ADJACENT HOUGHTON COUNTY...OFTEN AROUND TWIN
LAKES. HIGHER RES GUIDANCE SUGGESTS CONVERGENCE WILL REMAIN SET UP A
BIT FARTHER S AS HAS BEEN OCCURRING DURING THE NIGHT FROM THE
PORCUPINE MOUNTAINS TO BERGLAND. REGIONAL GEM AND ESPECIALLY THE
HIRES WRF-ARW HAVE DONE WELL DEPICTING SOME OF THE ACTIVITY OVER THE
WRN U.P. WILL THUS PAINT HIGHEST SNOW TOTALS IN ONTONAGON COUNTY AND
HOUGHTON COUNTY S OF TWIN LAKES. WILL PROBABLY FLIRT WITH 12HR-24HR
WARNING CRITERIA IN A FEW HIGHER TERRAIN LOCATIONS WHERE THE BEST
CONVERGENCE REMAINS NEARLY STATIONARY. TO THE E...W FLOW SO FAR
DURING THE NIGHT HAS KEPT MUCH OF THE LES OFFSHORE OF ERN ALGER/NRN
LUCE. LATEST RADAR TRENDS SHOW INCREASING LES INTENSITY/ORGANIZATION
OVER ERN LAKE SUPERIOR. AS WINDS VEER SLIGHTLY WITH PASSING
SHORTWAVE...ENHANCED CONVERGENCE ZONE SHOULD SHIFT S INTO NE
ALGER/NRN LUCE THIS MORNING. FAVORABLE INSTABILITY/MOISTURE AND
ONGOING HVY SNOW OVER NE/E LAKE SUPERIOR INDICATE POTENTIAL FOR
SIGNIFICANT LES OVER THE NEXT 12HRS. INTERESTING TO NOTE THAT THE
REGIONAL GEM REALLY ENHANCES THE N/NE LAND BREEZE OFF ONTARIO BEHIND
PASSING SHORTWAVE...ENOUGH SO THAT A LAKE NIPIGON ENHANCED HVY SNOW
BAND SHIFTS SW ALL THE WAY TO PICTURED ROCKS. HIGH RES WRF-ARW AND
LOCAL HIGH RES WRF HAVE A SIMILAR SCENARIO...BUT ONLY PUSH
CONVERGENCE ZONE AS FAR SW AS LUCE COUNTY TO POSSIBLY GRAND MARAIS.
STRONGLY FOCUSED CONVERGENCE/LAKE NIPIGON PRECONDITONING AND DEEP
CONVECTIVE/MOIST LAYER (KMQT RADAR INDICATES CLOUD TOPS TO 20K FT)
POINT TO INTENSE SNOWFALL RATES WHEN BANDS SHIFT SW INTO LUCE/NE
ALGER COUNTY. AT THIS POINT...LUCE COUNTY IS MOST LIKELY TO FALL
UNDER THE HEAVIER SNOW...SO WARNING LOOKS ON TRACK THERE. THERE IS
MORE UNCERTAINTY FOR ALGER SINCE BULK OF GUIDANCE DOES NOT SHIFT
CONVERGENCE ZONE AS FAR SW AS REGIONAL GEM/LOCAL HIGH RES WRF. FOR
NOW...WILL LEAVE ADVY FOR ALGER...BUT TRENDS WILL NEED TO MONITORED
CLOSELY THIS MORNING. AWAY FROM LES...EXPECT PARTLY TO MOSTLY CLOUDY
SKIES TODAY...THOUGH WHERE W WIND DOWNSLOPING IS MAXIMIZED IN CNTRL
UPPER MI...THERE MAY BE QUITE A BIT OF SUN THRU THE DAY.
LOW-LEVEL WINDS WILL BEGIN TO BACK LATE AFTN AND THRU TONIGHT...
SHIFTING LES N AND EVENTUALLY OUT OF UPPER MI. LAST OF THE LES
SHOULD PROBABLY EXIT UPPER MI AROUND 06Z TONIGHT. AHEAD OF THE
AMPLIFYING WRN CONUS TROF...A SHORTWAVE WILL STREAK E ALONG
U.S./CANADA BORDER TONIGHT/FRI. WAA REGIME AHEAD OF THE WAVE WILL
ALREADY BE SPREADING INTO THE UPPER GREAT LAKES OVERNIGHT. THERE
REMAINS UNCERTAINTY IN HOW FAR S SATURATION WILL OCCUR IN THE
WAA/STRONG ISENTROPIC REGIME. GIVEN THE STRENGTH OF ASCENT...AT
LEAST LOW POPS ACROSS THE N SEEM REASONABLE. AS WINDS BACK ACROSS
LAKE MICHIGAN...ADDITIONAL LOW-LEVEL MOISTENING SUPPORTS EXTENDING
POPS S ACROSS THE ERN FCST AREA AS WELL.
COLD FRONT ASSOCIATED WITH WAVE WILL DRIFT SE INTO UPPER MI FRI
NIGHT/EARLY SAT AND THEN BECOME STATIONARY AS SHORTWAVE EJECTS FROM
WRN TROF. MODELS CONTINUE TO SHOW GOOD CONTINUITY ON THIS SYSTEM. IF
ANYTHING...THERE APPEARS TO BE A SLIGHT OVERALL MODEL TREND TOWARD A
WEAKER/FLATTER WAVE OVER THE LAST SEVERAL MODEL RUNS. CLUSTERING OF
GUIDANCE IS GOOD WITH ALL INDICATING VERY SIMILAR TRACKS FROM KS
TO THE STRAITS AREA. SINCE SYSTEM WILL BE RELATIVELY FLAT/FAST
MOVING...THIS WILL MOST LIKELY BE AN ADVY TYPE SNOW EVENT SAT
AFTN/NIGHT OVER MUCH OF W AND CNTRL UPPER MI. RAIN/SNOW SHOULD
AFFECT MAINLY THE SCNTRL/SE FCST AREA. GLOBAL GEM HAS THE HEAVIEST
PCPN WITH TOTALS IN THE 0.75 TO 1 INCH RANGE ACROSS SCNTRL UPPER MI.
GFS/ECMWF MAX OUT AROUND A HALF INCH...THOUGH 00Z ECMWF HAS TRENDED
LESS. THERE WILL PROBABLY BE A BRIEF PERIOD OF LAKE ENHANCED SNOW
ACROSS THE W AND NCNTRL AS SYSTEM PASSES...LEADING TO GREATEST SNOW
ACCUMULATIONS IN THOSE AREAS.
A GENERALLY QUIET PERIOD OF WEATHER IS EXPECTED AFTER THE WEEKEND
SYSTEM. POLAR VORTEX SETTLING FROM THE NPOLE TO ALASKA WILL RESULT
IN INCREASING PACIFIC FLOW ACROSS THE CONUS...SPELLING A WARMING
TREND HERE NEXT WEEK. COULD BE UNSEASONABLY WARM BY THANKSGIVING AS
TROF SWINGING INTO THE WRN CONUS BACKS FLOW SW INTO THE GREAT LAKES.
ECMWF/GFS SHOW 850MB TEMPS PUSHING 8C FOR THANKSGIVING UNDER DRY
AIRMASS...SO IT COULD BE QUITE WARM FOR LATE NOV.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
COLD AIR MOVING ACROSS LAKE SUPERIOR WILL PRODUCE CLOUDS AND LAKE
EFFECT SNOW FOR THE WEST TO NORTHWEST WIND SNOW BELTS FOR THE TAF
PERIOD. THIS WILL LARGELY AFFECT KCMX WITH PERIODS OF MVFR CIGS
AND IFR VSBYS. WITH KIWD NOT BEING UNDER FAVORABLE FLOW FOR
SNOW...HAVE LEFT OUT MENTION...BUT DID KEEP MVFR CIGS FOR THE
OVERNIGHT PERIOD FROM MOISTURE CURRENTLY IN NRN MN. KSAW WILL SEE
VFR CONDITIONS THROUGH THE PERIOD. KIWD AND KCMX WILL BECOME VFR AS
SW WINDS WILL PUSH THE LAKE EFFECT CLOUDS OFFSHORE LATE THU
AFTERNOON INTO THU EVENING.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
A WEAK TROUGH HANGS ON ACROSS EASTERN LK SUPERIOR MUCH OF TODAY WITH
A CONTINUED POTENTIAL FOR MARGINAL GALE GUSTS OVER SOUTH CENTRAL LK
SUPERIOR. WINDS SLIGHTLY DIMINISH LATER TONIGHT INTO FRIDAY AS WEAK
RIDGE TONIGHT IS FOLLOWED BY A WEST-TO-EAST ORIENTED TROUGH BY
FRIDAY AFTN. SINCE THE TROUGH IS MORE OVER THE LAKE INSTEAD OF TO
THE THE NORTH...WHICH LIMITS PRESSURE FALLS TO ENHANCE STRONGER
WINDS...GALE POTENTIAL FOR FRIDAY HAS LESSENED. LOW PRESSURE OVER
THE PLAINS STILL ON TRACK TO LIFT ACROSS UPR LAKES SATURDAY AFTN AND
SATURDAY EVENING. MODELS HAVE TRENDED WEAKER OVER TIME WITH THE LOW
AND WINDS. UNLESS THERE A FCST OF A DEEPER SYSTEM RETURNS...SEEMS
THERE IS ONLY A LOW RISK OF NORTHERLY GALES WITH THE SYSTEM. HIGH
PRESSURE BUILDS BACK IN FOR EARLY NEXT WEEK...LEADING TO LIGHTER
WINDS BY THAT TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
MIZ001>003-006-084.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ007.
LAKE SUPERIOR...NONE.
LAKE MICHIGAN...NONE.
&&
$$
SYNOPSIS...ROLFSON
DISCUSSION...ROLFSON
AVIATION...07
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1154 PM EST WED NOV 16 2011
.SHORT TERM /TONIGHT AND THURSDAY/...
POTENT SHORTWAVE THAT MOVED THROUGH THE CWA LAST NIGHT WILL CONTINUE
NE THROUGH QUEBEC TONIGHT...LEAVING THE AREA UNDER AN UPPER TROUGH
FOR MUCH OF THE SHORT TERM PERIOD. LOW/MID LVL MOISTURE BEHIND THE
WAVE HAS SETTLED OVER THE NE HALF OF THE CWA TODAY AND IS EXPECTED
TO REMAIN THROUGH THE FIRST HALF OF THURS. THIS HAS AIDED SOME
SHOWER DEVELOPMENT OVER THE ERN LK THROUGH THE DAY. THESE BANDS HAVE
A NW TO SE APPEARANCE DUE TO THE NW WINDS ALOFT...BUT THE LLVL WINDS
W TO WNW WINDS HAVE BEEN GRADUALLY PUSHING THEM E. DRIER LLVL AIR
OVER WRN LK SUPERIOR HAS TRIED TO LIMIT LES EXTENT OVER THE WRN
U.P...BUT AN ADDITIONAL AREA OF LOW/MID LVL MOISTURE OVER NRN MN
/PRODUCING SCATTERED SHSN/ SHOULD BEGIN TO MOVE INTO THE AREA THIS
EVENING.
WITH THE AREA BETWEEN THE HIGH TO THE SW AND THE EXITING LOW IN
QUEBEC...EXPECT WNW FLOW TO CONTINUE THROUGH THURS. A LINGERING
TROUGH FROM THE EXITING LOW OVER ERN LK SUPERIOR FOR TONIGHT INTO
THURSDAY WILL HELP TO FOCUS WINDS A LITTLE MORE OUT OF THE NW OVER
NRN LUCE AND FAR ERN ALGER COUNTY AND INCREASE THE LLVL CONVERGENCE
IN THAT AREA. RUC ANALYSIS OF H850 TEMPS SHOWS VALUES RANGING FROM
-11C OVER WRN LK SUPERIOR TO -8C OVER ERN LK SUPERIOR. THESE TEMPS
SHOULD FALL A COUPLE DEGREES BY 12Z THURS WITH THE SECONDARY SURGE
OF COLD AIR BEHIND A WEAK H850 TROUGH AND REMAIN THROUGH THE DAY
THURS. THIS CREATES DELTA-T VALUES IN THE UPPER TEENS ACROSS THE LK
THROUGH THE PERIOD.
OVER THE W...PARAMETERS HAVE REALLY COME TOGETHER FOR MODERATE TO
POTENTIALLY HEAVY LES TONIGHT INTO TOMORROW MORNING. WITH THE
SLIGHTLY COLDER H850 TEMPS THERE...EXPECT MUCH OF THE LK INDUCED
FORCING TO BE RIGHT IN THE DGZ. MODELS STILL HINTING AT LLVL DRY AIR
OVER THE WRN CWA KEEPING CLOUD BASES NEAR 3KFT THROUGH THIS
EVENING...WHICH WILL LIMIT THE DEPTH OF THE CLOUD WITH EQL VALUES
FROM 7-10KFT. BUT H925-850 MOISTURE CURRENTLY LOCATED OVER NRN MN
SHOULD PUSH OVER WRN LK SUPERIOR AND THE WRN CWA OVERNIGHT TONIGHT
AND INTO TOMORROW MORNING. THIS SHOULD PROVIDED ADDITIONAL LLVL
MOISTURE TO REALLY ENHANCE THE LES IN THE WNW FAVORED LOCATIONS. LES
PARAMETER IS SHOWING THIS WELL...WITH A DIMINISHING TREND LATE THIS
AFTN AND INTO THE EVENING...BEFORE GREATLY INCREASING OVERNIGHT AND
INTO THURS MORNING. BIGGEST CONCERN IS THE WHAT THE EQL WILL BE.
BUFKIT SOUNDINGS DO HAVE SOME VARIABILITY ON IF THE EQL/S WILL RISE
TOWARDS 12-15KFT OVERNIGHT INTO THURS MORNING...WHICH DEPENDS ON A
DEGREE F OR TWO DIFFERENCE IN THE LK TEMPS. IF THAT OCCURS...COULD
SEE SNOW AMOUNTS BEING HIGHER THAN EXPECTED. FELT THE CURRENT
FORECAST WAS ON TRACK WITH HIGH END ADVISORY AMOUNTS WHERE THERE
WILL LIKELY BE ENHANCED CONVERGENCE OVER NRN ONTONAGON AND CENTRAL
HOUGHTON COUNTIES. THE EVENING SHIFT WILL NEED TO MONITOR TRENDS AND
IF THE SNOW BECOMES HEAVY EARLIER THAN EXPECTED...MAY NEED TO BUMP
UP THE ADVY TO A WARNING.
OVER THE E...WITH THE DEEPER MOISTURE AND EQL NEAR 15KFT FROM THE
EXITING WAVE...LES PARAMETERS ARE MUCH BETTER IN THIS AREA AND
SHOWING POTENTIAL FOR MODERATE TO HEAVY SNOW. THERE POTENTIALLY TWO
LIMITING FACTORS ON SNOW AMOUNTS REACHING WARNING CRITERIA.
FIRST...PREVIOUS SHIFT MENTIONED THE POTENTIAL FOR SNOW PELLETS OR
GRAUPEL AT TIMES TONIGHT...WHICH SEEMS REASONABLE THIS EVENING WITH
THE SLIGHTLY WARMER H850 TEMPS KEEPING THE BEST OMEGA BELOW THE DGZ.
BUT...AS TEMPS COOL OVERNIGHT BEHIND THE H850 TROUGH...EXPECT A
TRANSITION TO MAINLY SNOW. SECOND...THE WIND DIRECTION REMAINS A
CONCERN FOR TONIGHT. WITH NW WINDS SHIFTING MORE WRLY THROUGH THE
DAY TODAY...THE MAIN PCPN HAS BEEN RUNNING NEARLY PARALLEL TO SHORE
THIS AFTN. MODELS SHOW A SLIGHT WNW SHIFT TO THE H925 WINDS THIS
EVENING...BUT NOT SURE IF THIS WILL BE ENOUGH TO SLIDE THE DOMINATE
BAND ONSHORE FROM GRAND MARAIS EAST ALONG THE LUCE COUNTY SHORELINE.
WITH THE GEM/ECMWF/GFS AND LOCAL WRF SHOWING THE LINGERING SFC
TROUGH TIGHTENING UP OVER THE FAR ERN LK OVERNIGHT TONIGHT AND
DROPPING SE THURS MORNING...EXPECT THIS TO SHIFT THE WINDS NW ENOUGH
TO PUSH THE DOMINATE BAND INTO LUCE COUNTY. THUS...WITH
MODERATE/HEAVY SNOW...ALONG WITH GUSTY WINDS UP TO 30MPH...HAVE
SWITCHED THE LES WATCH OVER TO A WARNING FOR LUCE. WITH THE
UNCERTAINTY ON THE EXACT LOCATION OF THE BAND FOR THE GRAND MARAIS
AREA OF ALGER...HAVE SWITCHED THAT WATCH OVER TO AN LES ADVY...BUT
THERE REMAINS SOME BUST POTENTIAL BOTH WAYS. EXPECT THIS PERIOD OF
HEAVY SNOW TO CONTINUE THROUGH THURS MORNING UNDER THE NW WINDS.
CURRENT FORECAST HAS SNOWFALL AMOUNTS EXCEEDING A FOOT FOR PORTIONS
OF NRN LUCE COUNTY BY 00Z FRI.
DRIER MID LVL AIR BEGINS TO MOVE OVER THE SW HALF OF THE CWA THURS
AFTN...LOWERING THE EQL/S TOWARDS 5-6KFT BY 00Z FRI. THIS WILL
DIMINISH THE INTENSITY OF THE SHOWERS OVER THE W. OVER THE E...THESE
LESS FAVORABLE LES CONDITIONS DON/T ARRIVE UNTIL LATE THURS AFTN AND
INTO THURS EVENING AND HAVE ENDED THE WARNING AT 00Z.
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE SFC MAP AT 00Z STRONG HIGH PRESSURE ACROSS THE TN VALLEY WILL
EXTEND A RIDGE ACROSS WI AND WESTERN LAKE SUPERIOR...WITH A WEAK SFC
TROUGH EXTENDING FROM THE MAIN LOW OVER FAR EASTERN CANADA TO JUST
EAST OF LAKE SUPERIOR. THIS WILL ALLOW THE FOCUS FOR HEAVIER SNOW TO
DIMINISH ACROSS LAKE SUPERIOR...WITH NW WINDS BECOMING MORE AND MORE
WESTERLY AS THE EVENING PROGRESSES.
THE HIGH AMPLITUDE 500MB RIDGE OVER THE PACIFIC NORTHWEST AND
WESTERN CANADA WILL FLATTEN AS IT SLIDES ACROSS THE NORTHERN PLAINS
AND SOUTHERN MANITOBA BY 00Z FRIDAY. IT WILL STILL BE ENOUGH TO AT
LEAST TEMPORARILY SWEEP THE TROUGHS EAST OF THE AREA THURSDAY NIGHT
THROUGH THE START OF THE WEEKEND. HOWEVER...THE MAIN CULPRIT WILL
BUDGE LITTLE OVER THE SECOND HALF OF THE WORK WEEK...THAT BEING THE
500MB LOW SPINNING NEAR HUDSON BAY.
THE FAST SOUTHWESTERLY FLOW WILL RETURN...WITH THE APEX OF THE RIDGE
EXITING THE UPPER GREAT LAKES FRIDAY AFTERNOON/EVENING. ONE TROUGH
OVER NORTHERN MANITOBA AT 00Z SATURDAY SHOULD CROSS ONTARIO SATURDAY
AFTERNOON/EVENING. BEHIND THIS FEATURE A MORE DISTINCT TROUGH WILL
WASH OUT ALONG THE CANADIAN/U.S. BORDER...WITH A BROAD TROUGH
EXPECTED ACROSS LAKE SUPERIOR AND UPPER MI SATURDAY EVENING THROUGH
NEXT TUESDAY NIGHT. THE RESULT AT THE SFC WILL BE THE WEAKENING OF
THE 995MB SFC LOW CENTERED ACROSS SOUTHERN SASKATCHEWAN AT 00Z
FRIDAY...TO 1003MB BY 00Z SATURDAY JUST NW OF LAKE SUPERIOR. EVEN
WITH THE WEAKENING OF THIS SYSTEM THE TIGHTENING PRESSURE GRADIENT
WILL RESULT IN STRONGER SW WINDS AT THE SFC FRIDAY INTO EARLY FRIDAY
EVENING...MAINLY ACROSS THE EASTERN HALF OF THE CWA. THE RESULT WILL
BE A TROUGH OF LOW PRESSURE AT THE SFC EXTENDING BETWEEN 2 STRONGER
LOW OVER HUDSON BAY AND KANSAS AT 12Z SATURDAY OVER THE EAST HALF.
LOOK FOR A LOW TO PUSH NORTHEASTWARD ALONG THIS TROUGH FROM THE
CENTRAL TO SOUTHERN PLAINS. MODELS CONTINUE TO PLAY THE LOW TRACKING
NEAR THE STRAITS AROUND 06Z SUNDAY...WITH THE NAM FARTHEST
NORTH...AND THE ECMWF ON THE SOUTHERN END OF THE FORECAST ENVELOP.
THE CANADIAN LOOKS TO BE ABOUT 6 HOURS SLOW. MODERATE TO HEAVY SNOW
ACCUMULATIONS REMAIN POSSIBLE OVER THE WESTERN HALF OF UPPER MI
UNTIL HIGH PRESSURE BUILDS IN FROM THE WEST SUNDAY AFTERNOON.
LOOKING A BIT FARTHER OUT...THERE ARE A COUPLE OF 500MB WAVES WITHIN
THE BROAD TROUGH /WESTERLY FLOW/ THAT ARE DIFFICULT TO FORECAST. THE
FIRST WAVE FOR MONDAY IS MORE DISTINCT OFF THE 16/12Z RUN OF THE
GFS...BUT IS SIMILAR TIMING WISE...BUT IS MUCH WEAKER THAN WHAT IS
SHOWN OFF THE 16/00Z ECMWF. THE CANADIAN IS OUT OF PHASE WITH THE
GFS AND ECMWF STARTING AROUND 12Z MONDAY...OR ABOUT 6 HOURS SLOWER.
A SIMILAR TREND WAS NOTED WITH THE TUESDAY AFTERNOON/EVENING WEAK
TROUGH...WHERE THE GFS TIGHTENED UP THE TROUGH A BIT MORE THAN THE
ECMWF. FORECAST MODELS ARE ABOVE NORMAL CONSISTENCY WISE FOR NEXT
WEDNESDAY...WITH A LARGE 500MB RIDGE BUILDING IN FROM THE PLAINS
STATES.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
COLD AIR MOVING ACROSS LAKE SUPERIOR WILL PRODUCE CLOUDS AND LAKE
EFFECT SNOW FOR THE WEST TO NORTHWEST WIND SNOW BELTS FOR THE TAF
PERIOD. THIS WILL LARGELY AFFECT KCMX WITH PERIODS OF MVFR CIGS
AND IFR VSBYS. WITH KIWD NOT BEING UNDER FAVORABLE FLOW FOR
SNOW...HAVE LEFT OUT MENTION...BUT DID KEEP MVFR CIGS FOR THE
OVERNIGHT PERIOD FROM MOISTURE CURRENTLY IN NRN MN. KSAW WILL SEE
VFR CONDITIONS THROUGH THE PERIOD. KIWD AND KCMX WILL BECOME VFR AS
SW WINDS WILL PUSH THE LAKE EFFECT CLOUDS OFFSHORE LATE THU
AFTERNOON INTO THU EVENING.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
LOW PRESSURE ACROSS CENTRAL ONTARIO WILL KEEP A WEAK TROUGH ACROSS
EASTERN LS OVERNIGHT...WHICH WILL ASSIST IN FOCUSING THE STRONGER
GALE FORCE WINDS OF 35KTS OVER THE EASTERN HALF OF LS THROUGH THIS
EVENING. LOOK FOR A RIDGE OF HIGH PRESSURE TO BUILD IN THURSDAY INTO
THURSDAY NIGHT...WITH GUSTS CONTINUING 20 TO 30KTS. LOW PRESSURE
ACROSS SOUTHERN SASKATCHEWAN THURSDAY NIGHT WILL FILL SLIGHTLY JUST
NORTH OF LS FRIDAY NIGHT. AHEAD OF THIS FEATURE...STRONG SW WINDS
FRIDAY INTO FRIDAY NIGHT MAY RESULT IN A FEW GALE FORCE GUSTS ACROSS
EASTERN LS. EXPECT A NEARLY STATIONARY TROUGH OVER EASTERN LS ON
SATURDAY. LOW PRESSURE OVER THE CENTRAL PLAINS SATURDAY WILL MOVE
ALONG THE TROUGH...FILLING SLIGHTLY ACROSS NORTHERN LOWER MICHIGAN
BY SATURDAY NIGHT...WITH A BRIEF PERIOD OF NE GALES TO 35KT SATURDAY
AFTERNOON THAT MAY TRANSITION ACROSS THE ENTIRE LAKE AS WINDS TURN
MORE NORTHWESTERLY AS THE LOW EXITS NE. HIGH PRESSURE SHOULD SLIDE
IN FROM THE WEST SUNDAY...BEFORE SLOWLY DIPPING TO THE LOWER GREAT
LAKES ON MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THURSDAY FOR MIZ001>003-
084.
LAKE EFFECT SNOW WARNING FROM 10 PM THIS EVENING TO 7 PM EST
THURSDAY FOR MIZ007.
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 5 PM EST
THURSDAY FOR MIZ006.
LAKE SUPERIOR...NONE.
LAKE MICHIGAN...NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...07
MARINE...SRF/SF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
526 PM CST FRI NOV 18 2011
.AVIATION...00Z TAF. CHALLENGING FORECAST WITH CEILINGS AND
VISIBILITY CONCERNS. THE START OF THE FORECAST WILL BEGIN WITH VFR
CONDITIONS IN PLACE AS MID AND HIGH LEVEL CLOUDS STREAM ACROSS THE
REGION. INCREASING LOW LEVEL MOISTURE LATE TONIGHT INTO SATURDAY
COULD BRING STRATUS TO THE TERMINAL LOCATION...ALONG WITH THE
POSSIBILITY FOR FOG AND DRIZZLE. 18.18Z NAM VISIBILITY FORECASTS
SHOW IFR OR LOWER VISIBILITIES DEVELOPING OVERNIGHT...WHILE NAM
AND RUC PROXIMITY SOUNDINGS HAVE INCREASING LOW LEVEL MOISTURE
WHICH WOULD ALSO SUPPORT THE POSSIBILITY OF DRIZZLE OR FOG LATE
TONIGHT INTO SATURDAY. WILL SHOW STRATUS AND FOG TAKING HOLD AFTER
08Z TONIGHT...AND WILL DROP CEILINGS INTO IFR TERRITORY.
VISIBILITY RESTRICTIONS COULD CERTAINLY DROP FARTHER THAN CURRENTLY
DEPICTED IN THE FORECAST...AND THAT WILL BE SOMETHING TO WATCH AS
THE NIGHT PROGRESSES. DRIZZLE AND/OR FREEZING DRIZZLE ARE ANOTHER
POSSIBILITY...BUT WOULD LIKE TO WAIT A BIT LONGER BEFORE ADDING
THAT POSSIBILITY DUE TO LOW CONFIDENCE IN IT DEVELOPING AT KGRI.
WINDS WILL START LIGHT AND VARIABLE...BUT WILL BECOME GUSTY FROM
THE NORTH/NORTHWEST ON SATURDAY MORNING AS A COLD FRONT CROSSES
THE REGION.
&&
.PREV DISCUSSION... /ISSUED 245 PM CST FRI NOV 18 2011/
SHORT TERM...TONIGHT INTO SATURDAY. AN UPPER LEVEL SHORT WAVE
WILL RIDE OUT OF THE ROCKIES AND INTO THE NORTHERN PLAINS LATE
TONIGHT. A SFC AREA OF LOW PRESSURE OVER NORTHEAST COLORADO THIS
AFTERNOON WILL WEAKEN AND BECOME ELONGATED ALONG THE COLD FRONT
ON SATURDAY. STRONG NORTHWEST WINDS CAN BE EXPECTED ON SATURDAY
BEHIND THE COLD FRONT. THE WIND SHOULD REMAIN BELOW WIND ADVISORY
CRITERIA...BUT WILL CERTAINLY FEEL UNPLEASANT WITH TEMPERATURES
PRIMARILY IN THE 30S BEHIND THE FRONT.
PRECIPITATION TYPE ALONG WITH THE OVERALL CHANCE FOR PRECIPITATION
ARE A BIG FORECAST CHALLENGE. LOW LEVEL MOISTURE WILL POOL ALONG
THE COLD FRONT ACROSS SOUTH CENTRAL NEBRASKA AFTER MIDNIGHT.
FORECAST MODELS...ESPECIALLY THE 12Z NAM...SHOW THE QUICK
DEVELOPMENT OF A LOW 925MB CLOUD DECK BETWEEN MIDNIGHT AND 3
AM. THE SATURATED LAYER IS SHALLOW AND SHOULD BE CAPABLE OF ONLY
DRIZZLE OR FREEZING DRIZZLE DEPENDING ON THE SFC TEMPERATURES. SFC
TEMPERATURES ARE CERTAINLY A TRICKY FORECAST TONIGHT WITH MODEL
PROJECTIONS SHOWING A SIGNIFICANT RANGE IN TEMPERATURES FROM
NORTHWEST TO SOUTHEAST INCLUDING WHAT WILL LIKELY BE A VERY TIGHT
TEMPERATURE GRADIENT IN THE TRI CITIES. EARLY MORNING TEMPERATURES
WILL LIKELY BE BELOW FREEZING NORTHWEST OF THE TRI CITIES AND
ABOVE FREEZING SOUTHEAST OF THE TRI CITIES WITH NEAR FREEZING
TEMPERATURES IN THE TRI CITIES CORRIDOR. THE LOW LEVEL PROFILE
WILL ONLY BRIEFLY REMAIN SATURATED...SO ANY DRIZZLE THAT FALLS
WILL LIKELY NOT LAST VERY LONG. THE MAIN TIME FRAME WHEN PATCHY
DRIZZLE/FREEZING DRIZZLE WILL BE POSSIBLE WILL RUN FROM 5AM TO
11AM. THIS DOES NOT APPEAR TO BE TOO BIG OF A DEAL AS ANY
PRECIPITATION APPEARS AS THOUGH IT WILL BE VERY LIGHT WITH ONLY
TRACE AMOUNTS OF DRIZZLE/FREEZING DRIZZLE EXPECTED. HOWEVER...ANY
AMOUNT OF FREEZING DRIZZLE CAN RESULT IN PROBLEMS AND WE WILL
NEED TO KEEP A CLOSE EYE ON THIS SYSTEM AS IT TRACKS THROUGH
SATURDAY MORNING.
TEMPERATURES WILL REMAIN FAIRLY STEADY THROUGH THE DAY SATURDAY.
LONG TERM...SATURDAY NIGHT THROUGH FRIDAY. THE MAIN FORECAST
CONCERN...IF YOU WANT TO CALL IT THAT...IS A GLANCING BLOW ON THE
SOUTHEAST PART OF THE FORECAST AREA WITH RAIN MONDAY NIGHT/EARLY
TUESDAY. OTHERWISE...THANKSGIVING DAY IS LOOKING REAL GOOD.
THE UPPER FLOW IS NOT EASILY CHARACTERIZED THIS FORECAST CYCLE...
BUT STILL TENDS TO FIT THE RECENT TREND OF WEATHER SYSTEMS ABOUT
EVERY 3 DAYS OR SO WITH ASSOCIATED COOL DOWNS/WARM UPS. THE VAST
MAJORITY OF PRECIPITATION REMAINS FOCUSED TO THE SOUTH...AND EAST
IN THE MISSISSIPPI VALLEY.
SO...INITIALLY WE WILL SEE SHARPLY COLDER WEATHER SATURDAY NIGHT AND
SUNDAY IN THE WAKE OF SATURDAY/S COLD FRONT. EXPECT CLEARING SKIES
SATURDAY NIGHT...AND ALTHOUGH WINDS MAY BE A BIT GUSTY EARLY IN THE
EVENING...THEY SHOULD SETTLE DOWN QUICKLY. SUNDAY WILL BE SEASONALLY
COOL...WITH HIGHS OF 36 TO 42 DEGREES...OR ABOUT 10 DEGREES BELOW
NORMAL. GOOD NEWS IS WINDS WILL BE LIGHT WITH SOME SUNSHINE.
AREA WILL WARM UP A NOTCH MONDAY...BACK INTO THE 40S. CLOUDS WILL BE
NOTED OVER THE SOUTHEAST FORECAST AREA NEAR SOUTHERN PLAINS OPEN
WAVE MOVING ACROSS OKLAHOMA AN MISSOURI. MODELS CONTINUE TO KEEP MOST
OF THE PRECIPITATION TO THE SOUTH OF THE FORECAST AREA...WITH ONLY
SMALL CHANCES FOR LIGHT RAIN IN THE FAR SOUTHEAST FORECAST AREA. SNOW
SHOULD NOT BE AN ISSUE.
AFTER THAT SYSTEM PASSES...UPPER LEVEL SHORTWAVE RIDGING SETS UP FOR
THE MIDDLE OF THE WEEK...INCLUDING THANKSGIVING DAY. THE AREA WILL
START TO SEE A NICE DOWNSLOPE ENHANCED WARMING AND WEDNESDAY...AND
THAT WILL CONTINUE INTO THANKSGIVING DAY. LOOKS LIKE LOTS OF SUNSHINE
THANKSGIVING DAY WITH TEMPERATURES 5 TO 10 DEGREES ABOVE NORMAL. THE
ONLY ISSUE WILL BE WIND...AS MODELS HAVE DEPICTED A STRONG SOUTH TO
SOUTHWEST WIND FOR SEVERAL RUNS...EASILY IN 15 TO 25+ CATEGORY.
ON FRIDAY...DAY 7 OF THE FORECAST...ANOTHER UPPER LEVEL SYSTEM COMES
ACROSS THE US...MORE OF BROAD...OPEN TROUGH STRUCTURE. AS WITH MANY
OF THE RECENT SYSTEMS...MOISTURE IS SPARSE...AND THE BEST CHANCE FOR
PRECIPITATION APPEARS TO BE EAST OF THE FORECAST AREA AT THIS TIME.
IT WILL BE COOLER THE LATER HALF OF THE THANKSGIVING DAY HOLIDAY
WEEKEND...AT LEAST FRIDAY AND SATURDAY FOR SURE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1031 AM CST THU NOV 17 2011
.DISCUSSION...
ONLY MAJOR CHANGE FOR THE MORNING UPDATE WAS TO PULL POPS FOR THIS
AFTERNOON OVER THE NORTHWESTERN COUNTIES. LATEST NAM AND HRRR RUNS
DO NOT HAVE ANY PRECIP MOVING IN UNTIL AFTER 00Z. A FEW LIGHT
RADAR RETURNS HAVE SHOWN UP IN WESTERN ND...BUT NOTHING HAS
REACHED THE GROUND SO FAR. THINK THAT ANY SNOW WILL HOLD OFF UNTIL
AFTER 00Z TONIGHT AS THE SFC LOW MOVES OUT INTO THE PLAINS. MADE A
FEW MINOR TWEAKS TO CLOUDS AND TEMPERATURES TO REFLECT CURRENT
TRENDS...BUT CONTINUED TO KEEP HIGHS IN THE LOW 20S UNDER THE SNOW
COVER WITH WARMER TEMPS ELSEWHERE.
&&
.AVIATION...
VFR CONDITIONS WILL CONTINUE THROUGHOUT THE PERIOD AS CIRRUS
INCREASES OVER THE REGION. LIGHT AND VARIABLE WINDS THIS MORNING
WILL BEGIN TO INCREASE OUT OF THE SOUTHEAST AT AROUND 12KTS BY
LATE AFTERNOON. WINDS WILL SHIFT TO THE WEST BY FRIDAY MORNING AS
LOW PRESSURE OVER NORTHERN CANADA MOVES EAST.
&&
.PREV DISCUSSION... /ISSUED 320 AM CST THU NOV 17 2011/
SHORT TERM...
THE MAIN CHALLENGE WILL BE SNOW ACCUMULATION POTENTIAL IN THE
SOUTH ON SATURDAY. MODELS ARE IN VERY GOOD AGREEMENT WITH THIS
SYSTEM...AND THE GFS HAS BEEN VERY CONSISTENT OF LATE SO WILL UTILIZE.
FOR TODAY...SFC HIGH PRESSURE WILL QUICKLY MOVE OVER THE REGION
AND SLIDE EAST BY THIS EVENING. WITH TEMPS STARTING OUT COLD AND
SOME SNOW COVER IN THE NORTH...TEMPS WILL REMAIN BELOW NORMAL WITH
INCREASING MID/HIGH CLOUDS BY AFTERNOON. THERE WILL BE SOME BETTER
SATURATION IN THE FAR NW LATE THIS AFTERNOON SO WILL MENTION SOME
LOW POPS FOR LIGHT SNOW HERE.
FOR TONIGHT AND FRI...SFC LOW PRESSURE WILL TRACK ALONG OR JUST
NORTH OF THE INTERNATIONAL BORDER. STRONG MID LEVEL WAA AND
ISENTROPIC LIFT SHOULD MEAN THE THREAT FOR SOME LIGHT SNOW IN THE
FAR NORTH. THERE WILL BE A FAIRLY DEEP DRY LAYER IN PLACE
INITIALLY...SO MUCH OF THE LIFT WILL GO INTO SATURATING THE
COLUMN. WILL MAINTAIN SOME LOW POPS TONIGHT AND AGAIN FRIDAY
AFTERNOON IN THE NW WITH SOME WRAPAROUND SNOW SHOWERS POSSIBLE
NEAR THE COLD FRONT.
ON SATURDAY...A COLORADO LOW WILL QUICKLY EJECT INTO IOWA WITH A
POSITIVELY TILTED UPPER TROUGH. THERE WILL BE STRONG DEEP LAYERED
LIFT IN THE SOUTHERN 1/3 OF THE REGION PER Q VECTOR AND OMEGA
FIELDS. PWATS WILL BE AROUND 0.4 IN THE SOUTH...SUFFICIENT FOR 2-4
INCHES OF SNOW IN THE FAR SOUTH...TAPERING TO AROUND AN INCH OR
LESS NEAR FARGO. FURTHER NORTH...EXPECT DRY CONDITIONS AND
INCREASING NORTH WINDS WITH COLD AIR SPILLING INTO THE REGION.
TEMPS MAY EVEN FALL ON SATURDAY AFTERNOON WITH -15C AIR AT 850MB
MOVING INTO THE NORTH. THERE SHOULD BE SOME BLOWING SNOW IN THE
SOUTH WITH ABOUT 25-30KT TO MIX FROM AROUND 900MB...AND FAVORABLE
NORTHERLY VALLEY COMPONENT FOR CHANNEL LING WINDS. WILL MENTION IN
THE HWO WITH ADVISORY TYPE CONDITIONS POSSIBLE.
FOR SAT NIGHT...WITH CLEARING AFTER THE DEPARTING LOW...AND A
VERY COLD AIRMASS FOR THIS TIME OF YEAR...EXPECT LOWS NEAR OR
PERHAPS A FEW DEGREES BELOW ZERO BY SUNDAY MORNING IN THE NW.
LONG TERM...SUNDAY THROUGH WEDNESDAY NIGHT
GFS/ECMWF IN GOOD AGREEMENT THROUGH 00 UTC MONDAY...DIVERGING
SOMEWHAT THEREAFTER WITH STRENGTH AND TIMING OF INDIVIDUAL SHORT-
WAVES IN NEAR ZONAL FLOW ALOFT. SURFACE PATTERN WILL BE DOMINATED
BY A 1028 HPA HIGH AS IT MOVES SLOWLY ACROSS THE NORTHERN PLAINS AND
WITH LITTLE MOISTURE TO WORK WITH...EXPECT DRY CONDITIONS FOR THE
FIRST HALF OF NEXT WEEK. BIGGEST CHANGE TO SENSIBLE WEATHER WILL BE
A NICE WARMING TREND. TEMPERATURES IN THE 925 TO 850 HPA LAYER
INCREASE FROM NEAR -12 C SUNDAY MORNING TO +5 C ON WEDNESDAY. AS A
RESULT...EXPECT TEMPERATURES TO INCREASE A BIT EACH DAY...NEARING
40 DEGREES FOR HIGHS BY WEDNESDAY AFTERNOON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
JR
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
933 AM EST THU NOV 17 2011
.DISCUSSION...LINGERING AREAS OF LIGHT RAIN OR DRIZZLE OVER SW VA
AND NE TN SHOULD GIVE WAY TO SUNSHINE...AS CLEARING LINE IS ABOUT TO
MOVE ACROSS THE TN VALLEY. CONSIDERED AN UPDATE EARLIER BUT THE
INTENSITY OF THE LINGERING RAIN/DRIZZLE IS VERY LIGHT WITH PROBABLY
NOT MUCH MORE THAN 0.01 INCH. STILL WAITING TO SEE IF ANY REPORTS OF
SNOW COME IN FROM THE HIGHER ELEVATIONS OVER SW VA AND NE TN...WHERE
TEMPS FELL ENOUGH FOR A CHANGE TO SNOW ABOVE 3500 TO 4000 FEET.
WILL DO A TYPICAL MORNING UPDATE OF FORECAST GRIDS AND PRODUCTS BY
11 AM EST. 12Z UPPER AIR PLOTS AND LATEST RUC MODEL SHOW MODERATE
COLD AIR ADVECTION FROM SURFACE TO 850 MBS...WHICH WILL GREATLY
OFFSET THE EFFECTS OF SUNSHINE THIS AFTERNOON. THUS...FORECASTED
HIGHS ARE VERY LIKELY ON TRACK.
OTHERWISE...QUITE A CHILLY NIGHT AHEAD AS SURFACE RIDGE SETTLES OVER
THE REGION.
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
639 AM EST SAT NOV 19 2011
UPDATED AVIATION DISCUSSION FOR 12Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL
TROUGH OVER THE WRN CONUS AND A FLAT RIDGE OVER THE EAST RESULTING IN
SW FLOW FROM THE CNTRL ROCKIES TO THE UPPER GREAT LAKES. A GROWING
AREA OF COLDER CLOUD TOPS WAS DEVELOPING OVER THE NRN PLAINS IN
ADVANCE OF A STRONG SHORTWAVE TROUGH OVER SRN WY INTO NRN CO. AT THE
SFC...A TROUGH/FRONT EXTENDED FROM CNTRL UPPER MI THROUGH CNTRL WI
AND NE IA TO LOW PRES OVER WRN KS. RADARS INDICATED SNOW DEVELOPING
OVER SD ALIGNED WITH STRONG 700-600 MB FGEN.
&&
.DISCUSSION...
TODAY AND TONIGHT...MODELS WERE IN REASONABLY GOOD AGREEMENT WITH
THE TRACK OF THE LOW AND MAIN MID/UPPER LEVEL FEATURES. THE CNTRL
PLAINS LOW IS EXPECTED TO MOVE QUICKLY TO SW WI BY 00Z/SUN AND INTO
NRN LAKE HURON BY 06Z. A PERIOD OF STRONG MID/UPPER LEVEL FORCING IS
EXPECTED WITH THIS SYSTEM AS A COUPLED UPPER LEVEL JET STRUCTURE
PROVIDES STRONG UPPER LEVEL DIV AND INDUCES STRONG MID LEVEL FGEN.
THE NAM AND GFS HAVE BEEN CONSISTENT WITH THE POSITION OF THE
700-600 MB FGEN AND THE ASSOCIATED BAND OF STRONG ASCENT. THIS SHOULD
PLACE THE HEAVIER BAND OF PCPN FROM NEAR IWD TO MQT. MDL QPF AMOUNTS
OF 0.30 TO 0.50 INCHES SEEMS ON TRACK GIVEN THE AVAILABILITY OF 4
G/KG IN THE 290K-295 LAYER ( NEAR 700 MB). ALTHOUGH THE DGZ IS
EXPECTED TO BE RELATIVELY HIGH FROM ABOUT 10K TO 15K FT...IT
COINCIDES WITH THE STRONGER UPWARD MOTION SO THAT AVERAGE SNOW/WATER
RATIO VALUES TO AT LEAST 14/1 ARE EXPECTED DURING THE PERIOD OF
HEAVIER SNOW. THIS WOULD RESULT IN SNOWFALL AMOUNTS GENERALLY IN THE
4 TO 6 INCH RANGE. LAKE AND UPSLOPE TERRAIN ENHANCEMENT WITH BACKING
WINDS FROM NE TO N NEAR IWD AND MQT SHOULD BOOST SNOWFALL AMOUNTS BY
SEVERAL INCHES EVEN THOUGH THE STRONGER SYNOPTIC LIFT MOVES OFF TO
THE ENE QUICKLY BTWN 00Z-06Z. SO...UPGRADED WINTER WX ADVISORIES IN
THOSE LOCATIONS TO WARNINGS WHERE LCL AMOUNTS IN THE 6 TO 8 INCH
RANGE ARE EXPECTED. WITH A LATER CHANGEOVER TO SNOW IN ALGER COUNTY
WITH FCST SNOWFALL IN THE 2 TO 4 INCH RANGE...A WINTER WX ADVY WAS
ALSO POSTED.
THE RAIN SNOW LINE FROM ABOUT P53 TO JUST SE OF IMT THIS AFTERNOON
AND EARLY EVENING...BASED ON 00Z NAM CRITICAL THICKNESS AND WET-BULB
ZERO HEIGHTS...WILL SHIFT QUICKLY TO THE SE THIS EVENING AS THE LOW
MOVES EAST OF THE REGION. SO...SNOWFALL AMOUNTS OF AN INCH OR TWO
ARE ALSO POSSIBLE OVER THE SOUTH AND EAST.
SUNDAY....N TO NW WINDS AND 850 MB TEMPS AROUND -10C/-11C SHOULD KEEP SOME
SCT -SHSN GOING IN THE MORNING. AS THE SFC RIDGE BUILDS INTO THE
AREA IN THE AFTERNOON ALONG WITH DRIER AIR AND LOWER INVERSION
HEIGHTS...ANY REMAINING LES SHOULD END.
MONDAY...THE COMBINATION OF WAA AND A WEAK SHORTWAVE TROUGH MOVING
NEAR THE CANADA BORDER COULD BRING SOME LIGHT SNOW TO THE NRN GREAT
LAKES. HOWEVER...MOST OF THE PCPN WITH THIS SYSTEM SHOULD REMAIN
NORTH OF THE CWA...PER ECMWF/NAM.
FOR THE EXTENDED...
OVERALL...FAIRLY QUIET EXTENDED PERIOD PCPN WISE WITH WARM TEMPS THE
MAIN STORY LATE IN THE PERIOD. WEAK SHORTWAVE SLIDES ACROSS THE AREA
ON TUES INTO TUES NIGHT. UNCERTAINTY IN AMNT OF H850-700
MOISTURE...WITH MOST OF IT LOCATED IN SRN ONTARIO...SO WILL GO WITH
A DRY FORECAST FOR NOW. THEN STRONG RIDGE DEVELOPING OVER THE NRN
ROCKIES AT THE BEGINNING OF THE WEEK IS EXPECTED TO SHIFT EAST AND
OVER THE GREAT LAKES AREA ON WEDNESDAY AND REMAIN THROUGH FRI. THIS
WILL LEAD TO A WARM UP FOR THANKSGIVING DAY AND BLACK FRIDAY...WITH
HIGHS APPROACHING RECORD VALUES. SEVERAL FACTORS THAT COULD DISRUPT
THE WARM TEMPS...STRENGTH OF THE INVERSION...IF STRATUS DECK
DEVELOPS AND LINGERING SNOW COVER. H850 TEMPS RISE TOWARDS 8-10C ON
THURS AND REMAIN AROUND 7-8C ON FRI. THIS CREATES H850 TEMP
STANDARDIZED ANOMALIES THAT WILL APPROACH 2.5 FOR THURS AND 2.0 ON
FRI. CONCERN WOULD BE HOW DEEP MIXING WOULD OCCUR INTO THE SHARP
INVERSION SEEN ON ECMWF/GFS. GFS DOES HINT AT THE POTENTIAL FOR A
STRATUS DECK WILL MOISTURE TRAPPED BELOW THE INVERSION...WHICH COULD
KEEP TEMPS COOLER. BUT IF THAT DOESN/T OCCUR...ABUNDANT DRY AIR
ALOFT WOULD LEAD TO A DECENT WARM-UP AND CURRENTLY HAVE VALUES IN
THE UPPER 40S. WITH THE SOUTHWEST WINDS...EXPECT THE HIGHEST TEMPS
/AT LEAST LOWER 50S/ OVER THE DOWNSLOPE AREAS NEAR LK
SUPERIOR...ESPECIALLY IN LOCATIONS LACKING SNOW COVER.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
A LOW PRESSURE SYSTEM APPROACHING THE GREAT LAKES TODAY WILL BRING
LOWERING CIGS/VSBYS AS SNOW DEVELOPS TOWARDS AFTERNOON. THE SNOW
SHOULD FALL HEAVY AT TIMES...ESPECIALLY AT KIWD/KSAW...WHICH COULD
PRODUCE LIFR CIGS/VSBYS. AT THIS TIME...IT APPEARS THE HEAVIEST SNOW
WILL FALL BETWEEN 21Z AND 04Z. THE LOW WILL QUICKLY EXIT
OVERNIGHT...ALLOWING CIGS/VSBYS TO RISE...ALTHOUGH THERE WILL BE SOME
LINGERING LAKE EFFECT SNOW THROUGH DAYBREAK TOMORROW.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
A LOW PRESSURE SYSTEM MOVING FROM THE CENTRAL PLAINS THIS MORNING TO
NORTHERN LOWER MICHIGAN TONIGHT WILL BRING INCREASING NORTH TO
NORTHEAST WINDS TODAY INTO TONIGHT. THERE COULD BE A FEW NORTHERLY
GALE FORCE GUSTS TO 35KTS WITH THE PASSAGE OF THE LOW
TONIGHT...MAINLY OVER CENTRAL AND EASTERN LAKE SUPERIOR. WITH THE
FAST EXIT OF THE LOW ON SUNDAY...EXPECT WINDS TO QUICKLY DIMINISH AS
HIGH PRESSURE SETTLES OVER LK SUPERIOR. THIS HIGH WILL REMAIN OVER
THE GREAT LAKES THROUGH THE FIRST HALF OF THE WORK WEEK...AS ANOTHER
LOW MOVES THROUGH THE OHIO RIVER VALLEY TUESDAY INTO WEDNESDAY. WEAK
SFC TROUGH MOVING THROUGH ONTARIO ON MON COULD PRODUCE A FEW
SOUTHWEST GUSTS OF 25-30KTS OVER NRN LK SUPERIOR...OTHERWISE EXPECT
WINDS TO STAY BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 7 AM EST
SUNDAY FOR MIZ006.
WINTER STORM WARNING FROM 1 PM EST /NOON CST/ THIS AFTERNOON TO
7 AM EST /6 AM CST/ SUNDAY FOR MIZ002-004-005-009.
WINTER WEATHER ADVISORY FROM 1 PM EST /NOON CST/ THIS AFTERNOON
TO 3 AM EST /2 AM CST/ SUNDAY FOR MIZ001-003-010-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
EXTENDED...SRF
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
542 AM EST SAT NOV 19 2011
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL
TROUGH OVER THE WRN CONUS AND A FLAT RIDGE OVER THE EAST RESULTING IN
SW FLOW FROM THE CNTRL ROCKIES TO THE UPPER GREAT LAKES. A GROWING
AREA OF COLDER CLOUD TOPS WAS DEVELOPING OVER THE NRN PLAINS IN
ADVANCE OF A STRONG SHORTWAVE TROUGH OVER SRN WY INTO NRN CO. AT THE
SFC...A TROUGH/FRONT EXTENDED FROM CNTRL UPPER MI THROUGH CNTRL WI
AND NE IA TO LOW PRES OVER WRN KS. RADARS INDICATED SNOW DEVELOPING
OVER SD ALIGNED WITH STRONG 700-600 MB FGEN.
&&
.DISCUSSION...
TODAY AND TONIGHT...MODELS WERE IN REASONABLY GOOD AGREEMENT WITH
THE TRACK OF THE LOW AND MAIN MID/UPPER LEVEL FEATURES. THE CNTRL
PLAINS LOW IS EXPECTED TO MOVE QUICKLY TO SW WI BY 00Z/SUN AND INTO
NRN LAKE HURON BY 06Z. A PERIOD OF STRONG MID/UPPER LEVEL FORCING IS
EXPECTED WITH THIS SYSTEM AS A COUPLED UPPER LEVEL JET STRUCTURE
PROVIDES STRONG UPPER LEVEL DIV AND INDUCES STRONG MID LEVEL FGEN.
THE NAM AND GFS HAVE BEEN CONSISTENT WITH THE POSITION OF THE
700-600 MB FGEN AND THE ASSOCIATED BAND OF STRONG ASCENT. THIS SHOULD
PLACE THE HEAVIER BAND OF PCPN FROM NEAR IWD TO MQT. MDL QPF AMOUNTS
OF 0.30 TO 0.50 INCHES SEEMS ON TRACK GIVEN THE AVAILABILITY OF 4
G/KG IN THE 290K-295 LAYER ( NEAR 700 MB). ALTHOUGH THE DGZ IS
EXPECTED TO BE RELATIVELY HIGH FROM ABOUT 10K TO 15K FT...IT
COINCIDES WITH THE STRONGER UPWARD MOTION SO THAT AVERAGE SNOW/WATER
RATIO VALUES TO AT LEAST 14/1 ARE EXPECTED DURING THE PERIOD OF
HEAVIER SNOW. THIS WOULD RESULT IN SNOWFALL AMOUNTS GENERALLY IN THE
4 TO 6 INCH RANGE. LAKE AND UPSLOPE TERRAIN ENHANCEMENT WITH BACKING
WINDS FROM NE TO N NEAR IWD AND MQT SHOULD BOOST SNOWFALL AMOUNTS BY
SEVERAL INCHES EVEN THOUGH THE STRONGER SYNOPTIC LIFT MOVES OFF TO
THE ENE QUICKLY BTWN 00Z-06Z. SO...UPGRADED WINTER WX ADVISORIES IN
THOSE LOCATIONS TO WARNINGS WHERE LCL AMOUNTS IN THE 6 TO 8 INCH
RANGE ARE EXPECTED. WITH A LATER CHANGEOVER TO SNOW IN ALGER COUNTY
WITH FCST SNOWFALL IN THE 2 TO 4 INCH RANGE...A WINTER WX ADVY WAS
ALSO POSTED.
THE RAIN SNOW LINE FROM ABOUT P53 TO JUST SE OF IMT THIS AFTERNOON
AND EARLY EVENING...BASED ON 00Z NAM CRITICAL THICKNESS AND WET-BULB
ZERO HEIGHTS...WILL SHIFT QUICKLY TO THE SE THIS EVENING AS THE LOW
MOVES EAST OF THE REGION. SO...SNOWFALL AMOUNTS OF AN INCH OR TWO
ARE ALSO POSSIBLE OVER THE SOUTH AND EAST.
SUNDAY....N TO NW WINDS AND 850 MB TEMPS AROUND -10C/-11C SHOULD KEEP SOME
SCT -SHSN GOING IN THE MORNING. AS THE SFC RIDGE BUILDS INTO THE
AREA IN THE AFTERNOON ALONG WITH DRIER AIR AND LOWER INVERSION
HEIGHTS...ANY REMAINING LES SHOULD END.
MONDAY...THE COMBINATION OF WAA AND A WEAK SHORTWAVE TROUGH MOVING
NEAR THE CANADA BORDER COULD BRING SOME LIGHT SNOW TO THE NRN GREAT
LAKES. HOWEVER...MOST OF THE PCPN WITH THIS SYSTEM SHOULD REMAIN
NORTH OF THE CWA...PER ECMWF/NAM.
FOR THE EXTENDED...
OVERALL...FAIRLY QUIET EXTENDED PERIOD PCPN WISE WITH WARM TEMPS THE
MAIN STORY LATE IN THE PERIOD. WEAK SHORTWAVE SLIDES ACROSS THE AREA
ON TUES INTO TUES NIGHT. UNCERTAINTY IN AMNT OF H850-700
MOISTURE...WITH MOST OF IT LOCATED IN SRN ONTARIO...SO WILL GO WITH
A DRY FORECAST FOR NOW. THEN STRONG RIDGE DEVELOPING OVER THE NRN
ROCKIES AT THE BEGINNING OF THE WEEK IS EXPECTED TO SHIFT EAST AND
OVER THE GREAT LAKES AREA ON WEDNESDAY AND REMAIN THROUGH FRI. THIS
WILL LEAD TO A WARM UP FOR THANKSGIVING DAY AND BLACK FRIDAY...WITH
HIGHS APPROACHING RECORD VALUES. SEVERAL FACTORS THAT COULD DISRUPT
THE WARM TEMPS...STRENGTH OF THE INVERSION...IF STRATUS DECK
DEVELOPS AND LINGERING SNOW COVER. H850 TEMPS RISE TOWARDS 8-10C ON
THURS AND REMAIN AROUND 7-8C ON FRI. THIS CREATES H850 TEMP
STANDARDIZED ANOMALIES THAT WILL APPROACH 2.5 FOR THURS AND 2.0 ON
FRI. CONCERN WOULD BE HOW DEEP MIXING WOULD OCCUR INTO THE SHARP
INVERSION SEEN ON ECMWF/GFS. GFS DOES HINT AT THE POTENTIAL FOR A
STRATUS DECK WILL MOISTURE TRAPPED BELOW THE INVERSION...WHICH COULD
KEEP TEMPS COOLER. BUT IF THAT DOESN/T OCCUR...ABUNDANT DRY AIR
ALOFT WOULD LEAD TO A DECENT WARM-UP AND CURRENTLY HAVE VALUES IN
THE UPPER 40S. WITH THE SOUTHWEST WINDS...EXPECT THE HIGHEST TEMPS
/AT LEAST LOWER 50S/ OVER THE DOWNSLOPE AREAS NEAR LK
SUPERIOR...ESPECIALLY IN LOCATIONS LACKING SNOW COVER.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
MAIN CONCERN FOR THE TAF PERIOD WILL BE THE LOW PRESSURE SYSTEM
CROSSING EASTERN UPPER MICHIGAN SATURDAY AFTERNOON THROUGH SUNDAY
MORNING. CONDITIONS WILL CONTINUE TO DETERIORATE AS THE LOW DRAWS
CLOSER AND GO TO MVFR AT KCMX AND KIWD OVERNIGHT AND REMAIN VFR AT
KSAW TONIGHT. CONDITIONS WILL RAPIDLY DETERIORATE ON SATURDAY AS THE
SNOW COMES IN IN THE AFTERNOON AND WILL DROP TO IFR/LIFR AT KIWD AND
KCMX AND COULD DROP AS LOW AS VLIFR AT KSAW. UPSLOPE NORTH TO
NORTHEAST WINDS WILL ALSO HELP THE SNOW AND LOW CIGS AT KSAW AND
KIWD SATURDAY INTO SAT NIGHT. THE LIGHT TO MODERATE SNOW SHOULD LAST
ABOUT 8 HOURS OR SO BEFORE THE MOISTURE MOVES OUT LATE SATURDAY
NIGHT.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
A LOW PRESSURE SYSTEM MOVING FROM THE CENTRAL PLAINS THIS MORNING TO
NORTHERN LOWER MICHIGAN TONIGHT WILL BRING INCREASING NORTH TO
NORTHEAST WINDS TODAY INTO TONIGHT. THERE COULD BE A FEW NORTHERLY
GALE FORCE GUSTS TO 35KTS WITH THE PASSAGE OF THE LOW
TONIGHT...MAINLY OVER CENTRAL AND EASTERN LAKE SUPERIOR. WITH THE
FAST EXIT OF THE LOW ON SUNDAY...EXPECT WINDS TO QUICKLY DIMINISH AS
HIGH PRESSURE SETTLES OVER LK SUPERIOR. THIS HIGH WILL REMAIN OVER
THE GREAT LAKES THROUGH THE FIRST HALF OF THE WORK WEEK...AS ANOTHER
LOW MOVES THROUGH THE OHIO RIVER VALLEY TUESDAY INTO WEDNESDAY. WEAK
SFC TROUGH MOVING THROUGH ONTARIO ON MON COULD PRODUCE A FEW
SOUTHWEST GUSTS OF 25-30KTS OVER NRN LK SUPERIOR...OTHERWISE EXPECT
WINDS TO STAY BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 7 AM EST
SUNDAY FOR MIZ006.
WINTER STORM WARNING FROM 1 PM EST /NOON CST/ THIS AFTERNOON TO
7 AM EST /6 AM CST/ SUNDAY FOR MIZ002-004-005-009.
WINTER WEATHER ADVISORY FROM 1 PM EST /NOON CST/ THIS AFTERNOON
TO 3 AM EST /2 AM CST/ SUNDAY FOR MIZ001-003-010-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
EXTENDED...SRF
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
940 AM EST SAT NOV 19 2011
.SYNOPSIS...
HIGH PRESSURE CENTERED OFF THE NORTH CAROLINA COAST WILL EXTEND
WESTWARD OVER THE REGION THROUGH TUESDAY... BRINGING AN INCREASING
SOUTHERLY FLOW AND A WARMING TREND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM SATURDAY...
DESPITE THE SURFACE HIGH PRESSURE RIDGE EXTENDING FROM NORTHEAST TO
SOUTHWEST ACROSS CENTRAL NC AND .08 INCHES OF PW AT GSO THIS
MORNING...STRONG SOUTHERLY WARM ADVECTION AT 925MB (9C AT FCC AND 2C
GSO) IS SPREADING STRATUS NORTH OVER THE FOOTHILLS AND INTO THE
WESTERN PIEDMONT. ON ADDITION...WEAK ISENTROPIC LIFT AT 295K...PER
LOCAL HI-RES WRF GUIDANCE... APPEARS TO HAVE HELPED ESTABLISH A
NARROW REGION OF STRATUS ALONG THE I-95 CORRIDOR. THIS STRATUS OVER
THE EAST HAS LESS SUPPORT AND SHOULD LIFT TO SCATTERED STRATOCU THIS
MORNING AND NOT HAVE SIGNIFICANT IMPACT ON TEMPS THIS AFTERNOON. ON
THE OTHER HAND...THE REGIONAL SCALE STRATUS MOVING INTO THE WESTERN
PIEDMONT MAY ACTUALLY HOLD TEMPS DOWN ALONG THE WESTERN FRINGES OF
THE CWA...FROM WADESBORO TO WINSTON-SALEM. 06Z MAV GUIDANCE SEEMS
TO HAVE A BETTER HANDLE ON THIS...AND ADJUSTMENTS TOWARD MAV VALUES
YIELDS 53-61 FROM WEST TO EAST. HAVE ALSO ADJUST CLOUD COVER OVER
THE CENTRAL AND NORTHERN PIEDMONT TO SHOW MORE SUN THIS AFTERNOON
AND A GRADUAL INCREASE THIS EVENING. THIS IS IN LINE WITH
LATEST RUC GUIDANCE FOR KRDU WHICH SHOWS A MORE RAPIDLY INCREASE IN
MOISTURE THIS EVENING AS MOISTURE BECOMES TRAPPED BELOW THE
SUBSIDENCE AND NOCTURNAL INVERSIONS. -SMITH
OVERNIGHT... LOW STRATUS AND/OR FOG WILL KEEP LOWS WARMER THAN
PREVIOUS NIGHTS... GENERALLY IN THE LOW TO MID 40S. -KRR
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 317 AM SATURDAY...
SUNDAY AND SUNDAY NIGHT...WITH SURFACE HIGH PRESSURE EVEN FURTHER
OFFSHORE BY THIS POINT IN THE FORECAST...THE CONTINUED SOUTHERLY
FLOW ACROSS THE REGION WILL RESULT IN HIGH TEMPS REBOUNDING INTO THE
UPPER 60S TO LOWER 70S. MID/HIGH CLOUDS WILL BE ON THE INCREASE LATE
SUNDAY AS A FRONTAL SYSTEM TO OUR NORTH EDGES CLOSER TO THE FORECAST
AREA. WITH THE INCREASED CLOUDS AND MOISTURE...OVERNIGHT LOWS WILL
ONCE AGAIN EXPERIENCE A WARMING TREND...WITH MIN TEMPS ONLY EXPECTED
TO FALL INTO THE LOW 50S AREAWIDE. -KRR
MONDAY-MONDAY NIGHT...A FLAT BROAD UPPER LEVEL RIDGE OVER THE GULF
OF MEXICO AND THE MAIN BAND OF WESTERLIES STRETCHING ACROSS THE
GREAT LAKES INTO NEW ENGLAND WILL RESULT IN A MILD/WARM PERIOD
ACROSS CENTRAL NC. A SURFACE COLD FRONT WILL LIE TO OUR NORTH MONDAY
THEN TRY TO EDGE S-SW INTO CENTRAL NC MONDAY NIGHT AS A CANADIAN
HIGH PRESSURE SYSTEM TRAVERSES ACROSS NEW ENGLAND. MODELS HAVE BEEN
DIFFERING ON THE SOUTHWARD EXTENT OF THIS BOUNDARY WITH THE NAM AND
NOW THE LATEST ECMWF DRAGGING THE BOUNDARY NEAR OR JUST SW OF RDU BY
DAYBREAK TUESDAY WHILE THE GFS KEEPS THE FRONT TO OUR NE (CLOSER TO
RZZ/IXA). CONSIDERING THE STRENGTH OF THE HIGH AND THE LOW LEVEL
COLD AIR ASSOCIATED WITH THIS SYSTEM...MAY BE SOME VALIDITY IN THE
MORE SOUTHERN SCENARIO DEPICTED BY THE NAM/ECMWF. SW LOW LEVEL FLOW
MONDAY AHEAD OF THE FRONT SHOULD MAINTAIN WARM CONDITIONS.
THICKNESSES WITH FULL-PARTIAL SUN SUPPORT MAX TEMPS 10-14 DEGREES
ABOVE NORMAL...YIELDING AFTERNOON TEMPS IN THE 70-75 DEGREE RANGE.
DUE TO PROXIMITY OF THE FRONT AND MARGINAL MOISTURE AVAILABILITY
COUPLED WITH MODEST LIFT...WILL MAINTAIN A SLIGHT CHANCE POP OVER
THE NORTHERN COUNTIES MONDAY...AND A SLIGHT HIGHER POP (THOUGH STILL
SLIGHT CHANCE) OVER THE NORTHERN TWO-THIRDS MONDAY NIGHT. DUE TO
CLOUD COVERAGE...HAVE RAISED MON TEMPS UP A CATEGORY MOST LOCALES
MONDAY NIGHT FROM PREVIOUS FORECAST. MIN TEMPS 53-57. -WSS
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 337 AM SATURDAY...
TUESDAY...AS NEW ENGLAND HIGH SHIFTS OFFSHORE AND THE NEXT S/W AND
ATTENDANT COLD FRONT APPROACH FROM THE WEST...LOW LEVEL FLOW WILL
BECOME MORE SLY ACROSS CENTRAL NC. THIS WILL RETURN THE SURFACE
FRONT NWD AS A WARM FRONT TUESDAY. THE MODEST OVERRUNNING ALONG THIS
BOUNDARY MAY SUPPORT A FEW SHOWERS...MAINLY ACROSS OUR FAR
NORTH-NE COUNTIES. TIMING FAVORS TUESDAY MORNING. TUESDAY AFTERNOON
INTO TUESDAY EVENING SHOULD FEATURE MAINLY DRY AND SEASONABLY WARM
CONDITIONS. WITH LOW LEVEL THICKNESSES BACK INTO THE 1380S....EXPECT
ANOTHER DAY OF WELL ABOVE NORMAL TEMPS WITH HIGHS IN THE 70-75
DEGREE RANGE (WARMEST S-SW AND COOLER FAR NE).
AMPLIFYING S/W CROSSING THE GREAT LAKES AND OH VALLEY TUESDAY NIGHT
WILL ADVANCE AND CROSS CENTRAL NC WEDNESDAY. GFS TIMING IS STILL A
BIT FASTER COMPARED TO THE ECMWF. CONSIDERING THAT THE SYSTEM IS
AMPLIFYING TUESDAY NIGHT INTO WEDNESDAY MORNING...FAVOR SLOWER
TIMING OF THE ECMWF. EFFECTIVE BULK SHEAR INCREASES LATE TUESDAY
NIGHT INTO WEDNESDAY AHEAD OF THE SYSTEM. THUS...SHOULD SEE BROKEN
BANDS OF SHOWERS AHEAD OF THE FRONT. EXPECT SHOWER ACTIVITY TO
INCREASE AFTER MIDNIGHT OVER THE NW PIEDMONT...AND ACROSS THE
REMAINDER OF THE PIEDMONT BY WEDNESDAY MORNING. BY WEDNESDAY
AFTERNOON SURFACE FRONT SHOULD BISECT THE FORECAST AREA...SUGGESTING
BULK OF SHOWERS OCCURRING ALONG AND EAST OF HIGHWAY 1. WHILE BULK
SHEAR SUPPORTIVE OF ORGANIZED CONVECTION...MODELS DEPICT LITTLE IF
ANY LOW LEVEL INSTABILITY AT THIS TIME AND HELICITY MARGINAL AT
BEST. THUS WHILE CANNOT RULE OUT A FEW T-STORMS...MAINLY IN THE EAST
WEDNESDAY AFTERNOON...CURRENT CONVECTIVE PARAMETERS SUGGEST MINIMAL
SEVERE WEATHER THREAT AT THIS TIME. TEMPS WEDNESDAY HIGHLY DEPENDENT
ON SHOWER COVERAGE. POTENTIAL FOR A WIDER MAX TEMP VARIANCE THAN
CURRENTLY FORECAST (WITH WARMER MAX TEMPS POSSIBLE SE).
FRONTAL SYSTEM SHOULD EXIT THE REGION EARLY WEDNESDAY EVENING WITH
IMPROVING WEATHER CONDITIONS. DRY AND SEASONABLY COOL TEMPS EXPECTED
IN THE WAKE OF THE SYSTEM FOR THANKSGIVING DAY AND FRIDAY AS HIGH
PRESSURE BUILDS INTO THEN SETTLES OVER THE REGION.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 630 AM SATURDAY...
CURRENT SATELLITE IMAGERY AND OBSERVATIONS INDICATE THAT A NARROW
BAND OF STRATUS HAS DEVELOPED ACROSS THE COASTAL PLAIN...WITH SOME
SITES BRIEFLY EXPERIENCING MVFR CIGS. ONCE THE SUN COMES UP AND SOME
MIXING BEGINS...AM EXPECTING THE CLOUDS TO SCATTER OUT BRIEFLY. AS A
SURFACE HIGH PRESSURE CONTINUES TO SHIFT OFFSHORE TODAY...A
WARM/MOIST SOUTHERLY RETURN FLOW WILL INCREASE ACROSS THE REGION (AN
AREA OF CLOUDINESS ASSOCIATED WITH THIS RETURN FLOW CAN ALREADY BE
SEEN ACROSS GEORGIA AND SOUTH CAROLINA). THIS SOUTHERLY RETURN
FLOW/WARM ADVECTION THAT WILL RESULT IN THE POTENTIAL DEVELOPMENT OF
MVFR CEILINGS LATER THIS MORNING OR THIS AFTERNOON. CONFIDENCE IS
STILL NOT VERY HIGH WITH RESPECT TO WHETHER OR NOT THE CLOUDS WILL
BE BROKEN OR SCATTERED...BUT OVERALL...CLOUDS WILL BE ON THE
INCREASE THROUGH THE DAY. THEN...IFR/LIFR CIGS/VSBYS ARE EXPECTED TO
DEVELOP OVERNIGHT IN ASSOCIATION WITH THE CONTINUED SOUTHERLY RETURN
FLOW AND WARM ADVECTION.
OUTLOOK...CEILINGS SHOULD IMPROVE TO MVFR AND EVENTUALLY VFR BETWEEN
12-18Z SUN IN ASSOC/W DIURNAL HEATING AND MIXING. IFR/LIFR
CONDITIONS WILL BE POSSIBLE AGAIN BETWEEN 00-12Z MON...ALTHOUGH
THERE IS LESS CERTAINTY THAN THE 00-12Z SUN PERIOD. UNCERTAINTY
INCREASES BY EARLY/MID NEXT WEEK. AT THIS TIME...EXPECT MVFR
CEILINGS WITH PERIODS OF IFR CEILINGS (PRIMARILY OVERNIGHT) TO
PREDOMINATE MON/TUE AHEAD OF A STORM SYSTEM EXPECTED TO DEVELOP IN
THE CENTRAL PLAINS AND LOWER MS RIVER VALLEY. THE AFOREMENTIONED
STORM SYSTEM IS EXPECTED TO AFFECT THE CAROLINAS LATE TUE
NIGHT/WED...BRINGING WITH IT A CHANCE FOR SHOWERS/STORMS. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GIH
NEAR TERM...KRR/SMITH
SHORT TERM...KRR/WSS
LONG TERM...WSS
AVIATION...KRR/VINCENT
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
405 PM EST SAT NOV 19 2011
.SYNOPSIS...
HIGH PRESSURE PUSHES FARTHER OUT TO SEA TONIGHT AND SUNDAY. A
FRONT WILL APPROACH FROM THE NORTHWEST LATE SUNDAY...AND BECOME
NEARLY STATIONARY OVER THE REGION MONDAY AND MONDAY NIGHT. THE
FRONT WILL LIFT NORTH OF THE AREA AS A WARM FRONT ON TUESDAY. A
COLD FRONT WILL THEN PUSH THROUGH THE MID ATLANTIC STATES ON
WEDNESDAY...WITH HIGH PRESSURE BUILDING IN FROM THE WEST
THANKSGIVING DAY INTO NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
CURRENT SFC ANALYSIS SHOWS HIGH PRESSURE CENTERED WELL OFF THE
DELMARVA COAST. RETURN SW FLOW AROUND THE BACKSIDE OF THE HIGH HAS
PROVIDED A MILDER DAY ACROSS THE FCST REGION...WHILE ALSO BRINGING
PERIODIC WAA CLOUDINESS (MAINLY UPPER LEVEL). LLVL TRAJECTORIES
OUT OF THE GULF STREAM (BTWN ILM-MHX) DID PROVIDE A PERIOD OF
ENHANCED LLVL THETA-E WITH THE HIGHER DWPTS...WHICH IN TURN LED TO
THE DEVELOPMENT OF A SHALLOW STRATO-CU DECK THAT PERSISTED FOR A
WHILE FROM THE LATE AM INTO EARLY AFTN HRS BEFORE MIXING OUT.
FOR THE OVERNIGHT HOURS...THE MAIN FCST CHALLENGE WILL BE WITH
CLOUD COVER...ESPECIALLY REGARDING THE DEVELOPMENT OF ANY LOWER
CLOUD DECKS (STRATUS LAYERS) WITH THE LIGHT S/SW FLOW. BOTH THE
GFS/NAM AS WELL AS THE RUC FCST SOUNDINGS ALL SHOW A HIGH
POTENTIAL FOR THE DEVELOPMENT OF A LOWER CLOUD DECK...WITH A
STRONG SFC-BASED INVERSION WITH TEMPS AS WELL AS MIXING RATIO
(MSTR) THROUGH 1000-975 MB. HOWEVER...MOST OF THE NUMERICAL
GUIDANCE IS NOT PICKING UP ON THESE CLOUDS...THOUGH PER THE FCST
SOUNDINGS...OTHER LOWER LAYER MSTR (BTWN 900-800 MB) IS NOTED...
PARTICULARLY E OF I-95. THE UPSHOT IS LOWER THAN AVERAGE
CONFIDENCE IN TERMS OF THE SKY FCST OVERNIGHT...THOUGH BELIEVE
THERE IS ENOUGH EVIDENCE TO GO WITH A TREND TOWARD MOSTLY CLOUDY
LATE TONIGHT/EARLY SUN. LOWS NOT AS COLD COMPARED TO THE LAST
COUPLE NIGHTS...GIVEN THE CLOUD COVER AND S/SW FLOW UNDER 10 KTS.
MIN TEMPS GENERALLY THROUGH THE 40S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
MID/UPR LVL FLO WILL BECOME MORE ZNL ACRS THE FA LATER SUN THRU
MON. THE RESULT WILL BE A FRNTL BNDRY THAT WILL DROP INTO THE AREA
TO NEAR THE VA/NC BORDER. THERE WILL BE MORE CLDS ACRS THE NRN/NW
CNTIES BY LATE IN THE DAY...AS THE FRNT APPROACHES FM THE NW.
OTHRWISE...DRY AND MILD CONDITIONS WILL PREVAIL ON SUN WITH MUCH
OF THE REGION GENERALLY PRTLY SNY. MAX TEMPS WILL BE IN THE MID TO
UPR 60S MOST LOCATIONS...THOUGH CANNOT RULE OUT 70+ READINGS OVER
THE FAR SRN PTNS (ALONG/S OF THE VA/NC BORDER) WITH THE GREATER
AMOUNT OF SUNSHINE.
SFC FRNTL BNDRY THEN DROPS INTO THE AREA SUN NGT THRU MON...
STALLING NEAR THE VA/NC BORDER BY LATE MON. GOING WITH HIEST POPS
NEAR 50 PERCENT ACRS THE N-NW 1/3 OF THE AREA LATE SUN NGT AND
MON...DECREASING TO SLGT CHC POPS OVR SRN 1/3 OF THE REGION. LOWS
SUN NGT IN THE UPR 40S TO MID 50S. HIGHS ON MON QUITE VARIABLE
ONCE AGAIN...FROM THE UPPER 50S/NEAR 60 TO LOWER 70S OVER SRN
VA/NERN NC. BECMG MSTLY CLDY OR CLDY SUN NGT...AND MSTLY CLDY OR
CLDY ON MON.
STALLED FRONTAL BOUNDARY ACROSS RGN MONDAY NIGHT SLOWLY LIFTS N
AS A WARM FRONT TUESDAY IN RESPONSE TO LOW PRESSURE APPROACHING
FROM THE W. WILL KEEP CHC POPS IN FCST ON TUE...AGAIN WITH THE
HIGHEST CHANCES OVER THE NRN TIER. LOWS TUE AM IN U40S-M50S...
HIGHS FROM THE M60S FAR N TO THE L70S S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
FOLLOWING THE SLOWER ECMWF SOLN WRT THE COLD FRNTL PASSAGE WED.
LOW PRS MOVES NE THRU OHIO VLLY TUE NITE WITH ASSCTD WRM FRONT
LIFTG N ACROSS THE AREA. MILD WITH CHC SHWRS. LOWS IN THE 50S
AS FA BECOMES WRM SCTRD. TRAILING COLD FRONT CROSSES FA WED AFTRN
THEN EXITS OFFSHORE WED EVE. AGAIN THIS THE SLOWER SOLN THAN GFS
WHICH HAS A FROPA WED MORN. KEPT CHC POPS ATTM BUT ADDED THUNDER
AS DATA SUGGESTS MRGINAL INSTAB AHEAD OF BNDRY. HIGHS IN THE 60S
TO NR 70.
LINGERING SHWRS ALONG THE COAST WED EVE...FOLLOWED BY STRNG CAA
WED NITE INTO THURSDAY AS LOW PRS DEEPENS TO THE NE AND 1030MB
HIGH PRS BLDG INTO RGN FROM W. DRY BUT COOL THUR AND FRI. HIGHS
THU 50-55...M-U50S FRI. LOWS IN THE 30S. DRY AND MILDER SAT WITH
MORE CLOUD COVER. HIGHS U50S-L60S.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE SHIFTS OFF THE COAST ALLOWING FOR A SW WIND ACROSS
THE REGION. THIS SOUTHERLY FLOW A WILL ALLOW FOR MOISTURE OVER
THE SOUTHEAST TO SPREAD N. SATELLITE SHOWING STRATOCU OVER HAMPTON
ROADS AND CENTRAL NC MOVG N/NE WITH FLOW. BELIEVE THIS MOISTURE
WILL AFFECT THE REGION OVERNIGHT AND WITH SOUNDING INDICATING
INVERSION SETTING UP...MAY SEE SOME STRATUS AROUND 1000-2000 FT
DEVELOP IN THE EARLY MORNING HOURS. THIS SHOULD IMPROVE TO VFR BY
LATE MORNING TO AFTERNOON.
DRY AND VFR CONDITIONS SHOULD CONTINUE INTO MONDAY BEFORE BEFORE
THE NEXT FRONT APPROACHES LATE MONDAY.
&&
.MARINE...
NO FLAGS THRU THE WEEKEND AS HIGH PRS PARKS ITSELF OFF THE SERN
COAST. RETURN S-SW FLOW AOB 15 KTS THRU SUN NIGHT. SEAS 2-3 FT.
BACKDOOR TYPE COLD FRONT SAGS S ACROSS MID ATLNTC COAST MON BUT
A QSTN IS TO HOW FAR S THE BNDRY ACTUALLY GETS. WINDS SHFT INTO
N-NE BY MON AFTRN BUT LTST DATA KEEPS CONDITIONS BLO SCA LVLS.
THIS BNDRY PROGGED TO LIFT BACK N AS A WARM FRONT TUE NITE IN
RESPONSE TO LOW PRS APPRCHG FROM THE S. NXT CHC FOR FLAGS COMES
WED INTO THU AS S WNDS INCRS AHEAD AHEAD OF CDFRNT. STRNG CAA
PROGGED BEHIND BNDRY WED NITE INTO THU. MAY EVEN SEE NW GALES
WITH THIS EVENT BUT CAPPED GUSTS AT 30 KTS FOR NOW.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BKH
NEAR TERM...BKH
SHORT TERM...BKH
LONG TERM...MPR
AVIATION...JEF
MARINE...MPR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1241 PM EST SAT NOV 19 2011
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL
TROUGH OVER THE WRN CONUS AND A FLAT RIDGE OVER THE EAST RESULTING IN
SW FLOW FROM THE CNTRL ROCKIES TO THE UPPER GREAT LAKES. A GROWING
AREA OF COLDER CLOUD TOPS WAS DEVELOPING OVER THE NRN PLAINS IN
ADVANCE OF A STRONG SHORTWAVE TROUGH OVER SRN WY INTO NRN CO. AT THE
SFC...A TROUGH/FRONT EXTENDED FROM CNTRL UPPER MI THROUGH CNTRL WI
AND NE IA TO LOW PRES OVER WRN KS. RADARS INDICATED SNOW DEVELOPING
OVER SD ALIGNED WITH STRONG 700-600 MB FGEN.
&&
.DISCUSSION...
TODAY AND TONIGHT...MODELS WERE IN REASONABLY GOOD AGREEMENT WITH
THE TRACK OF THE LOW AND MAIN MID/UPPER LEVEL FEATURES. THE CNTRL
PLAINS LOW IS EXPECTED TO MOVE QUICKLY TO SW WI BY 00Z/SUN AND INTO
NRN LAKE HURON BY 06Z. A PERIOD OF STRONG MID/UPPER LEVEL FORCING IS
EXPECTED WITH THIS SYSTEM AS A COUPLED UPPER LEVEL JET STRUCTURE
PROVIDES STRONG UPPER LEVEL DIV AND INDUCES STRONG MID LEVEL FGEN.
THE NAM AND GFS HAVE BEEN CONSISTENT WITH THE POSITION OF THE
700-600 MB FGEN AND THE ASSOCIATED BAND OF STRONG ASCENT. THIS SHOULD
PLACE THE HEAVIER BAND OF PCPN FROM NEAR IWD TO MQT. MDL QPF AMOUNTS
OF 0.30 TO 0.50 INCHES SEEMS ON TRACK GIVEN THE AVAILABILITY OF 4
G/KG IN THE 290K-295 LAYER ( NEAR 700 MB). ALTHOUGH THE DGZ IS
EXPECTED TO BE RELATIVELY HIGH FROM ABOUT 10K TO 15K FT...IT
COINCIDES WITH THE STRONGER UPWARD MOTION SO THAT AVERAGE SNOW/WATER
RATIO VALUES TO AT LEAST 14/1 ARE EXPECTED DURING THE PERIOD OF
HEAVIER SNOW. THIS WOULD RESULT IN SNOWFALL AMOUNTS GENERALLY IN THE
4 TO 6 INCH RANGE. LAKE AND UPSLOPE TERRAIN ENHANCEMENT WITH BACKING
WINDS FROM NE TO N NEAR IWD AND MQT SHOULD BOOST SNOWFALL AMOUNTS BY
SEVERAL INCHES EVEN THOUGH THE STRONGER SYNOPTIC LIFT MOVES OFF TO
THE ENE QUICKLY BTWN 00Z-06Z. SO...UPGRADED WINTER WX ADVISORIES IN
THOSE LOCATIONS TO WARNINGS WHERE LCL AMOUNTS IN THE 6 TO 8 INCH
RANGE ARE EXPECTED. WITH A LATER CHANGEOVER TO SNOW IN ALGER COUNTY
WITH FCST SNOWFALL IN THE 2 TO 4 INCH RANGE...A WINTER WX ADVY WAS
ALSO POSTED.
THE RAIN SNOW LINE FROM ABOUT P53 TO JUST SE OF IMT THIS AFTERNOON
AND EARLY EVENING...BASED ON 00Z NAM CRITICAL THICKNESS AND WET-BULB
ZERO HEIGHTS...WILL SHIFT QUICKLY TO THE SE THIS EVENING AS THE LOW
MOVES EAST OF THE REGION. SO...SNOWFALL AMOUNTS OF AN INCH OR TWO
ARE ALSO POSSIBLE OVER THE SOUTH AND EAST.
SUNDAY....N TO NW WINDS AND 850 MB TEMPS AROUND -10C/-11C SHOULD KEEP SOME
SCT -SHSN GOING IN THE MORNING. AS THE SFC RIDGE BUILDS INTO THE
AREA IN THE AFTERNOON ALONG WITH DRIER AIR AND LOWER INVERSION
HEIGHTS...ANY REMAINING LES SHOULD END.
MONDAY...THE COMBINATION OF WAA AND A WEAK SHORTWAVE TROUGH MOVING
NEAR THE CANADA BORDER COULD BRING SOME LIGHT SNOW TO THE NRN GREAT
LAKES. HOWEVER...MOST OF THE PCPN WITH THIS SYSTEM SHOULD REMAIN
NORTH OF THE CWA...PER ECMWF/NAM.
FOR THE EXTENDED...
OVERALL...FAIRLY QUIET EXTENDED PERIOD PCPN WISE WITH WARM TEMPS THE
MAIN STORY LATE IN THE PERIOD. WEAK SHORTWAVE SLIDES ACROSS THE AREA
ON TUES INTO TUES NIGHT. UNCERTAINTY IN AMNT OF H850-700
MOISTURE...WITH MOST OF IT LOCATED IN SRN ONTARIO...SO WILL GO WITH
A DRY FORECAST FOR NOW. THEN STRONG RIDGE DEVELOPING OVER THE NRN
ROCKIES AT THE BEGINNING OF THE WEEK IS EXPECTED TO SHIFT EAST AND
OVER THE GREAT LAKES AREA ON WEDNESDAY AND REMAIN THROUGH FRI. THIS
WILL LEAD TO A WARM UP FOR THANKSGIVING DAY AND BLACK FRIDAY...WITH
HIGHS APPROACHING RECORD VALUES. SEVERAL FACTORS THAT COULD DISRUPT
THE WARM TEMPS...STRENGTH OF THE INVERSION...IF STRATUS DECK
DEVELOPS AND LINGERING SNOW COVER. H850 TEMPS RISE TOWARDS 8-10C ON
THURS AND REMAIN AROUND 7-8C ON FRI. THIS CREATES H850 TEMP
STANDARDIZED ANOMALIES THAT WILL APPROACH 2.5 FOR THURS AND 2.0 ON
FRI. CONCERN WOULD BE HOW DEEP MIXING WOULD OCCUR INTO THE SHARP
INVERSION SEEN ON ECMWF/GFS. GFS DOES HINT AT THE POTENTIAL FOR A
STRATUS DECK WILL MOISTURE TRAPPED BELOW THE INVERSION...WHICH COULD
KEEP TEMPS COOLER. BUT IF THAT DOESN/T OCCUR...ABUNDANT DRY AIR
ALOFT WOULD LEAD TO A DECENT WARM-UP AND CURRENTLY HAVE VALUES IN
THE UPPER 40S. WITH THE SOUTHWEST WINDS...EXPECT THE HIGHEST TEMPS
/AT LEAST LOWER 50S/ OVER THE DOWNSLOPE AREAS NEAR LK
SUPERIOR...ESPECIALLY IN LOCATIONS LACKING SNOW COVER.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
THE SW TO NE ORIENTED STATIONARY FRONT ACROSS THE EASTERN HALF OF
UPPER MI WILL SLIDE EASTWARD OVERNIGHT IN RESPONSE TO THE LOW
NEARING FROM THE SW...WHICH SHOULD BE ACROSS NORTHERN LOWER MI BY
06Z. THE RESULT WILL CONTINUE TO BE AN INFLUX OF COOLER AIR...AND
STRONG NORTHERLY WINDS. MOISTURE STREAMING NORTHWARD AHEAD OF THE
LOW WILL CONTINUE MODERAT TO HEAVY SNOW AT TIMES...ESPECIALLY AT
KIWD/KSAW...WHICH COULD PRODUCE LIFR CIGS/VSBYS...THIS AFTERNOON AND
EVENING. EXPECT THE N WINDS TO DIMINISH TOWARDS DAYBREAK AS HIGH
PRESSURE NEARS FROM THE WEST...WITH WINDS BECOMING NW WEST TO EAST
OVER THE MORNING HOURS SUNDAY. THIS WILL MEAN SIGNIFICANT DRYING IN
THE MID LEVELS...WITH A QUICK END TO LAKE EFFECT/ENHANCED SNOW
SHOWERS AT ALL 3 TAF SITES.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
A LOW PRESSURE SYSTEM MOVING FROM THE CENTRAL PLAINS THIS MORNING TO
NORTHERN LOWER MICHIGAN TONIGHT WILL BRING INCREASING NORTH TO
NORTHEAST WINDS TODAY INTO TONIGHT. THERE COULD BE A FEW NORTHERLY
GALE FORCE GUSTS TO 35KTS WITH THE PASSAGE OF THE LOW
TONIGHT...MAINLY OVER CENTRAL AND EASTERN LAKE SUPERIOR. WITH THE
FAST EXIT OF THE LOW ON SUNDAY...EXPECT WINDS TO QUICKLY DIMINISH AS
HIGH PRESSURE SETTLES OVER LK SUPERIOR. THIS HIGH WILL REMAIN OVER
THE GREAT LAKES THROUGH THE FIRST HALF OF THE WORK WEEK...AS ANOTHER
LOW MOVES THROUGH THE OHIO RIVER VALLEY TUESDAY INTO WEDNESDAY. WEAK
SFC TROUGH MOVING THROUGH ONTARIO ON MON COULD PRODUCE A FEW
SOUTHWEST GUSTS OF 25-30KTS OVER NRN LK SUPERIOR...OTHERWISE EXPECT
WINDS TO STAY BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 7 AM EST
SUNDAY FOR MIZ006.
WINTER STORM WARNING UNTIL 7 AM EST /6 AM CST/ SUNDAY FOR MIZ002-
004-005-009.
WINTER WEATHER ADVISORY UNTIL 3 AM EST /2 AM CST/ SUNDAY FOR
MIZ001-003-010-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...KF
MARINE...SRF
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1138 AM CST SAT NOV 19 2011
.AVIATION...18Z TAF ISSUANCE...
NARROW BAND OF SNOW SHOWERS CONTINUES TO DEVELOP ACROSS THE SRN
HALF OF THE FORECAST AREA FROM AROUND BRD EASTWARD TO ASH/HYR.
THESE SHSN ARE PRODUCING PERIODS OF IFR/LIFR CIGS AND VSBYS WITHIN
THE MDT/HVY SNOW SHOWERS. THIS LINE OF SNOW WILL LINGER ACROSS THE
REGION AND SLOWLY MOVE TO THE EAST THIS AFTERNOON. OCCASIONAL LIFR
VSBYS ARE POSSIBLE FROM BRD TO DLH TO HYR. INL AND HIB SHOULD STAY
MOSTLY DRY UNDER LOW-END MVFR OR HIGH-END IFR CIGS. CONDITIONS
IMPROVE TONIGHT FOR ALL TERMINALS EXCEPT HYR...WHICH STAYS
BLANKETED UNDER THE LAKE EFFECT CLOUDS. A LOW DECK OF STRATUS
POSSIBLY MOVES THROUGH BY LATE MORNING TOMORROW FROM W TO E. WINDS
REMAIN FAIRLY LIGHT FROM THE N/NW.
&&
.PREV DISCUSSION... /ISSUED 1051 AM CST SAT NOV 19 2011/
UPDATE...REMOVED THE HEADLINES FROM SOUTHERN CASS...CROW
WING...AITKIN...SOUTHERN ST. LOUIS AND CARLTON COUNTIES. LATEST
RUC ANALYSIS...NAM12 AND GEM REG ALL SUPPORT THIS THINKING.
CURRENT RADAR OBS LINE UP WELL WITH RUC 850-700 FRONTOGENESIS MAX
WHICH IS SOUTH OF AFOREMENTIONED HEADLINED AREAS. BEST AXIS OF
HIGHER SNOW TOTALS APPEARS TO BE ACROSS PINE COUNTY IN MN AND
ALL OF NW WI. STILL EXPECTING ABOUT 3 TO 5 INCHES WHERE REMAINING
ADVISORY HEADLINES ARE PLACE. NO CHANGE TO THE WINTER STORM
WARNING FOR ASHLAND AND IRON COUNTIES AS LAKE EFFECT PARAMETERS
COME INTO PLAY LATER.
PREV DISCUSSION... /ISSUED 544 AM CST SAT NOV 19 2011/
AVIATION...12Z TAFS
LOW PRESSURE IN THE CO/KS AREA IS FORECAST TO MOVE TOWARD
SOUTHWEST WI BY THIS EVENING...THEN CONTINUE NORTHEAST TONIGHT
INTO QUEBEC.
HIGH CLOUDS HAVE OVERTAKEN THE REGION...MASKING THE MVFR CEILINGS
THAT COVERED MUCH OF THE NORTHLAND. THERE ARE SOME BREAKS IN THIS
MVFR DECK AS NOTED IN SOME OF THE SURFACE OBSERVATIONS.
OVERALL...MVFR CEILINGS...WITH SOME IFR...ARE EXPECTED INTO THIS
EVENING. MODELS HAVE BEEN SHIFTING THE MAIN AREA OF PRECIPITATION
A BIT FURTHER SOUTH OVER THE PAST COUPLE OF MODEL RUNS.
HOWEVER...CURRENT SATELLITE AND RADAR LOOPS SHOW RETURNS IN AN
AREA OF MID LEVEL FGEN...AND THAT IS FORECAST TO CONTINUE THIS
MORNING...SHIFTING NORTH THROUGH THE DAY. WE EXPECT SNOW TO IMPACT
THE KDLH/KHYR/KBRD TAFS LATER THIS MORNING OR EARLY THIS
AFTERNOON. IT WILL TAKE SOME TIME TO SATURATE THE LOW LEVELS...AS
MUCH OF THE RETURNS ON RADAR WERE NOT HITTING THE GROUND. IFR
VSBYS WILL BE POSSIBLE IN THE SNOW ONCE IT GETS STARTED. THE LOW
IS MOVING OFF QUICKLY...SO THE SNOW SHOULD DIMINISH FROM WEST TO
EAST OVERNIGHT.
PREV DISCUSSION... /ISSUED 348 AM CST SAT NOV 19 2011/
SHORT TERM...TODAY THROUGH SUNDAY
A BAND OF ACCUMULATING SNOWFALL APPEARS TO BE ON TRACK FOR AREAS
ALONG AND SOUTH OF THE HIGHWAY 2 CORRIDOR.
LOW PRESSURE OVER THE CENTRAL ROCKIES WILL QUICKLY EJECT
NORTHEASTWARD EARLY THIS MORNING AND BE OVER EASTERN IOWA LATE
THIS AFTERNOON. REGIONAL RADAR CURRENTLY SHOWS A RELATIVELY NARROW
BAND OF SNOW OVER SOUTH DAKOTA EDGING INTO WEST CENTRAL MINNESOTA.
THE AREAL EXTENT OF THE PRECIPITATION LINES UP WELL WITH THE NAM40
700 MB FRONTOGENESIS AT 09Z. SOME CONCERNS BY 15Z AS THE NAM
DEPICTS THE GREATEST FGEN IN A CORRIDOR FROM BRD TO DLH AND
EASTWARD TO ASX. THEREFORE...STARTED THE WINTER WEATHER ADVISORY
SEVERAL HOURS EARLIER FOR THE SOUTHWESTERN CWA. BY 21Z...ANOTHER
AREA OF FGEN MOVES INTO NORTHWESTERN WISCONSIN...WHERE THE THERMAL
GRADIENT IS STRONGEST. DUE TO THE SPEED OF THIS SYSTEM...EXPECTING
SNOW AMOUNTS IN THE 2 TO 5 INCH RANGE ACROSS THE SOUTHERN HALF OF
THE CWA. THERE WILL LIKELY BE A NARROW CORRIDOR OF SLIGHTLY HIGHER
AMOUNTS SOUTH OF THE TWIN PORTS AND INTO NORTHWESTERN WISCONSIN.
THE SNOW WILL QUICKLY DEPART THE MINNESOTA ZONES BY MIDNIGHT.
LAKE ENHANCEMENT NEAR THE SNOW BELT REGIONS OF ASHLAND AND IRON
COUNTIES WILL ADD TO THE SNOWFALL TOTALS IN THAT AREA. ALSO...A
WINDOW OF OPPORTUNITY EXISTS FOR LAKE EFFECT SNOW SHOWERS BETWEEN
03Z AND 09Z FOR THE GOGEBIC RANGE AS WINDS BECOME NORTHERLY BEHIND
THE DEPARTING LOW PRESSURE SYSTEM. DECREASING CLOUDS AND BELOW
NORMAL TEMPERATURES WILL OVERTAKE THE NORTHLAND ON SUNDAY AS AN
AREA OF SURFACE HIGH PRESSURE DEVELOPS OVER THE RED RIVER VALLEY.
EXTENDED...SUNDAY NIGHT THROUGH FRIDAY.
UPPER FLOW WILL BE FAST ZONAL EARLY IN THE PERIOD...WITH A COUPLE
EMBEDDED SHORTWAVES THROUGH TUESDAY. THE UPPER FLOW WILL AMPLIFY AS
A RIDGE DEVELOPS AND MOVES TOWARD THE REGION WEDNESDAY-THURSDAY. THE
RIDGE WILL PASS EAST OF THE NORTHLAND LATER THURSDAY WITH A TROUGH
OF LOW PRESSURE MOVING IN FOR FRIDAY-SATURDAY. THE GFS AND ECMWF ARE
IN PRETTY GOOD AGREEMENT WITH THE UPPER LEVEL FLOW. TEMPERATURES
WILL BE WARMING THROUGH NEXT WEEK AS THE RIDGE STARTS TO BUILD
IN...THEN COOL WITH THE TROUGH LATE.
THE FIRST SHORTWAVE WILL BRING SOME LIGHT SNOW/FLURRIES TO PORTIONS
OF THE NORTHLAND AS EARLY AS SUNDAY NIGHT...BUT IT SHOULD EXIT BY
MONDAY AFTERNOON. WE KEPT THE FORECAST DRY WITH THE SECOND SHORTWAVE
ON TUESDAY...AS THE WAVE LOOKS WEAKER AND THERE IS LESS MOISTURE
AVAILABLE. IT SHOULD BE DRY AND WARMER WEDNESDAY AND THURSDAY...WITH
FRIDAY A TRANSITION PERIOD AS THE TROUGH APPROACHES AND TEMPS BEGIN
TO COOL. WE KEPT THE MAJORITY OF THE NORTHLAND DRY ON FRIDAY.
TEMPS SHOULD WARM FROM THE UPPER TWENTIES-MID THIRTIES EARLY IN THE
PERIOD...INTO THE FORTIES WEDNESDAY-FRIDAY.
&&
.POINT TEMPS/POPS...
DLH 30 11 23 17 / 50 10 0 10
INL 21 6 21 9 / 10 10 0 20
BRD 28 8 24 15 / 60 10 0 10
HYR 36 15 27 15 / 80 40 10 10
ASX 35 19 29 16 / 70 50 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 10 PM CST THIS EVENING FOR MNZ038.
WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST SUNDAY FOR WIZ001-002-
006>009.
WINTER STORM WARNING UNTIL 6 AM CST SUNDAY FOR WIZ003-004.
LS...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 9 AM CST SUNDAY
FOR LSZ121-140>148.
&&
$$
AVIATION...TENTINGER
AREA FORECAST DISCUSSION
NWS DULUTH MN
1051 AM CST SAT NOV 19 2011
.UPDATE...REMOVED THE HEADLINES FROM SOUTHERN CASS...CROW
WING...AITKIN...SOUTHERN ST. LOUIS AND CARLTON COUNTIES. LATEST
RUC ANALYSIS...NAM12 AND GEM REG ALL SUPPORT THIS THINKING.
CURRENT RADAR OBS LINE UP WELL WITH RUC 850-700 FRONTOGENESIS MAX
WHICH IS SOUTH OF AFOREMENTIONED HEADLINED AREAS. BEST AXIS OF
HIGHER SNOW TOTALS APPEARS TO BE ACROSS PINE COUNTY IN MN AND
ALL OF NW WI. STILL EXPECTING ABOUT 3 TO 5 INCHES WHERE REMAINING
ADVISORY HEADLINES ARE PLACE. NO CHANGE TO THE WINTER STORM
WARNING FOR ASHLAND AND IRON COUNTIES AS LAKE EFFECT PARAMETERS
COME INTO PLAY LATER.
&&
.PREV DISCUSSION... /ISSUED 544 AM CST SAT NOV 19 2011/
AVIATION...12Z TAFS
LOW PRESSURE IN THE CO/KS AREA IS FORECAST TO MOVE TOWARD
SOUTHWEST WI BY THIS EVENING...THEN CONTINUE NORTHEAST TONIGHT
INTO QUEBEC.
HIGH CLOUDS HAVE OVERTAKEN THE REGION...MASKING THE MVFR CEILINGS
THAT COVERED MUCH OF THE NORTHLAND. THERE ARE SOME BREAKS IN THIS
MVFR DECK AS NOTED IN SOME OF THE SURFACE OBSERVATIONS.
OVERALL...MVFR CEILINGS...WITH SOME IFR...ARE EXPECTED INTO THIS
EVENING. MODELS HAVE BEEN SHIFTING THE MAIN AREA OF PRECIPITATION
A BIT FURTHER SOUTH OVER THE PAST COUPLE OF MODEL RUNS.
HOWEVER...CURRENT SATELLITE AND RADAR LOOPS SHOW RETURNS IN AN
AREA OF MID LEVEL FGEN...AND THAT IS FORECAST TO CONTINUE THIS
MORNING...SHIFTING NORTH THROUGH THE DAY. WE EXPECT SNOW TO IMPACT
THE KDLH/KHYR/KBRD TAFS LATER THIS MORNING OR EARLY THIS
AFTERNOON. IT WILL TAKE SOME TIME TO SATURATE THE LOW LEVELS...AS
MUCH OF THE RETURNS ON RADAR WERE NOT HITTING THE GROUND. IFR
VSBYS WILL BE POSSIBLE IN THE SNOW ONCE IT GETS STARTED. THE LOW
IS MOVING OFF QUICKLY...SO THE SNOW SHOULD DIMINISH FROM WEST TO
EAST OVERNIGHT.
PREV DISCUSSION... /ISSUED 348 AM CST SAT NOV 19 2011/
SHORT TERM...TODAY THROUGH SUNDAY
A BAND OF ACCUMULATING SNOWFALL APPEARS TO BE ON TRACK FOR AREAS
ALONG AND SOUTH OF THE HIGHWAY 2 CORRIDOR.
LOW PRESSURE OVER THE CENTRAL ROCKIES WILL QUICKLY EJECT
NORTHEASTWARD EARLY THIS MORNING AND BE OVER EASTERN IOWA LATE
THIS AFTERNOON. REGIONAL RADAR CURRENTLY SHOWS A RELATIVELY NARROW
BAND OF SNOW OVER SOUTH DAKOTA EDGING INTO WEST CENTRAL MINNESOTA.
THE AREAL EXTENT OF THE PRECIPITATION LINES UP WELL WITH THE NAM40
700 MB FRONTOGENESIS AT 09Z. SOME CONCERNS BY 15Z AS THE NAM
DEPICTS THE GREATEST FGEN IN A CORRIDOR FROM BRD TO DLH AND
EASTWARD TO ASX. THEREFORE...STARTED THE WINTER WEATHER ADVISORY
SEVERAL HOURS EARLIER FOR THE SOUTHWESTERN CWA. BY 21Z...ANOTHER
AREA OF FGEN MOVES INTO NORTHWESTERN WISCONSIN...WHERE THE THERMAL
GRADIENT IS STRONGEST. DUE TO THE SPEED OF THIS SYSTEM...EXPECTING
SNOW AMOUNTS IN THE 2 TO 5 INCH RANGE ACROSS THE SOUTHERN HALF OF
THE CWA. THERE WILL LIKELY BE A NARROW CORRIDOR OF SLIGHTLY HIGHER
AMOUNTS SOUTH OF THE TWIN PORTS AND INTO NORTHWESTERN WISCONSIN.
THE SNOW WILL QUICKLY DEPART THE MINNESOTA ZONES BY MIDNIGHT.
LAKE ENHANCEMENT NEAR THE SNOW BELT REGIONS OF ASHLAND AND IRON
COUNTIES WILL ADD TO THE SNOWFALL TOTALS IN THAT AREA. ALSO...A
WINDOW OF OPPORTUNITY EXISTS FOR LAKE EFFECT SNOW SHOWERS BETWEEN
03Z AND 09Z FOR THE GOGEBIC RANGE AS WINDS BECOME NORTHERLY BEHIND
THE DEPARTING LOW PRESSURE SYSTEM. DECREASING CLOUDS AND BELOW
NORMAL TEMPERATURES WILL OVERTAKE THE NORTHLAND ON SUNDAY AS AN
AREA OF SURFACE HIGH PRESSURE DEVELOPS OVER THE RED RIVER VALLEY.
EXTENDED...SUNDAY NIGHT THROUGH FRIDAY.
UPPER FLOW WILL BE FAST ZONAL EARLY IN THE PERIOD...WITH A COUPLE
EMBEDDED SHORTWAVES THROUGH TUESDAY. THE UPPER FLOW WILL AMPLIFY AS
A RIDGE DEVELOPS AND MOVES TOWARD THE REGION WEDNESDAY-THURSDAY. THE
RIDGE WILL PASS EAST OF THE NORTHLAND LATER THURSDAY WITH A TROUGH
OF LOW PRESSURE MOVING IN FOR FRIDAY-SATURDAY. THE GFS AND ECMWF ARE
IN PRETTY GOOD AGREEMENT WITH THE UPPER LEVEL FLOW. TEMPERATURES
WILL BE WARMING THROUGH NEXT WEEK AS THE RIDGE STARTS TO BUILD
IN...THEN COOL WITH THE TROUGH LATE.
THE FIRST SHORTWAVE WILL BRING SOME LIGHT SNOW/FLURRIES TO PORTIONS
OF THE NORTHLAND AS EARLY AS SUNDAY NIGHT...BUT IT SHOULD EXIT BY
MONDAY AFTERNOON. WE KEPT THE FORECAST DRY WITH THE SECOND SHORTWAVE
ON TUESDAY...AS THE WAVE LOOKS WEAKER AND THERE IS LESS MOISTURE
AVAILABLE. IT SHOULD BE DRY AND WARMER WEDNESDAY AND THURSDAY...WITH
FRIDAY A TRANSITION PERIOD AS THE TROUGH APPROACHES AND TEMPS BEGIN
TO COOL. WE KEPT THE MAJORITY OF THE NORTHLAND DRY ON FRIDAY.
TEMPS SHOULD WARM FROM THE UPPER TWENTIES-MID THIRTIES EARLY IN THE
PERIOD...INTO THE FORTIES WEDNESDAY-FRIDAY.
&&
.POINT TEMPS/POPS...
DLH 30 11 23 17 / 50 10 0 10
INL 20 6 21 9 / 10 10 0 20
BRD 28 8 24 15 / 60 10 0 10
HYR 36 15 27 15 / 80 40 10 10
ASX 35 19 29 16 / 70 50 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 10 PM CST THIS EVENING FOR MNZ038.
WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST SUNDAY FOR WIZ001-002-
006>009.
WINTER STORM WARNING UNTIL 6 AM CST SUNDAY FOR WIZ003-004.
LS...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 9 AM CST SUNDAY
FOR LSZ121-140>148.
&&
$$
SHORT TERM...GSF
LONG TERM....TENTINGER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
325 PM EST SAT NOV 19 2011
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE THIS WEEKEND AND INTO EARLY NEXT
WEEK. TEMPERATURES WILL BEGIN TO WARM OVER THE WEEKEND AS SOUTHERLY
WINDS DEVELOP. A COLD FRONT WILL MOVE THROUGH WEDNESDAY. COOLER
WEATHER IS EXPECTED LATE NEXT WEEK AS HIGH PRESSURE BUILDS IN.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...SURFACE TROUGH REMAINING JUST TO THE EAST OF
LOCAL COASTAL WATERS WILL SHIFT FARTHER WEST CLOSER TO THE CAROLINA
COAST THROUGH THIS EVENING BEFORE DISSIPATING OVERNIGHT. LIGHT
NORTHEAST FLOW ON WEST SIDE OF TROUGH WILL SHIFT MORE EASTERLY
ESPECIALLY ALONG THE COAST AS IT SHIFTS CLOSER. OVERALL WEAK
GRADIENT WITH WINDS REMAINING 5 MPH OR LESS MOST PLACES AT THE
SURFACE. RUC SOUNDINGS SHOWING AN OVERALL WARMING AND DRYING OF THE
COLUMN AT LOW LEVELS AS WARMER AIR MAKES ITS WAY IN ALOFT AND MIXING
OCCURS THROUGH TODAY...BUT DECENT ON SHORE SE FLOW AT H85 CONTINUING
TO BRING MOISTURE AND SOME CLOUDS ON SHORE MAINLY OVER SC.
ON SHORE FLOW WILL CAPTURE SOME OF THE MARINE INFLUENCE CONTINUING
TO BRING HIGHER DEWPOINT AIR INLAND AS WINDS SHIFT BECOMING MORE
EASTERLY. THE DEWPOINTS ALONG THE COAST WILL REMAIN IN THE 50S
THROUGH MOST OF THE NIGHT WHILE INLAND DEWPOINTS WILL BE IN THE MID
40S. WAA WILL CONTINUE WITH SW FLOW ABOVE THE SURFACE. 850 TEMPS
AROUND 4 TO 5 C THIS MORNING WILL RISE UP TO AROUND 8C BY DAYBREAK
ON SUNDAY. LOW LEVEL FLOW WILL CONTINUE TO COME AROUND FROM S-SE TO
SW OVERNIGHT WHILE SURFACE WINDS BECOME VERY LIGHT AND VARIABLE TO
NEAR CALM. CLOUDS ASSOCIATED WITH COASTAL TROUGH MAY MOVE ON SHORE
THROUGH THIS EVENING AS H85 FLOW CONTINUES OUT OF THE SE BEFORE
SHIFTING TO S-SW OVERNIGHT. THE SFC TROUGH AXIS SHIFTS A LITTLE
FARTHER WEST BUT DISSIPATES OVERNIGHT AS HIGH PRESSURE CONTINUES TO
RIDGE BACK INTO THE CAROLINAS. OVERALL VERY WEAK PRESSURE PATTERN
EXPECTED WITH CALM WINDS. FOR NOW WILL KEEP MOST CLOUDS OUT OF THE
EQUATION ALLOWING FOR MORE IDEAL RADIATIONAL COOLING AND DENSER FOG
THREAT...BUT THE EXTENT OF FOG WILL DEPEND ON HOW MUCH CLOUD COVER
THERE WILL BE...WHICH WILL BE THE FORECAST CHALLENGE OVERNIGHT.
TEMPS WILL DROP OFF AS WE RADIATE OUT OVER MOST PLACES BUT
WAA...INCREASED LOW LEVEL MOISTURE AND SOME CLOUDS WILL KEEP TEMPS
AND SFC DEWPOINTS HIGHER THAN PREVIOUS NIGHTS. FORECAST LOWS WILL
THEREFORE DROP TO THE LOW TO MID 40S MOST PLACES INLAND AND CLOSER
TO 50 ALONG THE COAST.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...HIGH PRESSURE WILL SHIFT OFF THE COAST SUNDAY
AND RESULT IN WARMING S-SW FLOW THROUGH THE PERIOD. THERE WILL BE
SOME INCREASE IN CLOUDS MONDAY NIGHT AS A FRONTAL SYSTEM APPROACHES
FROM THE WEST...OTHERWISE FAIR WEATHER IS EXPECTED. HIGHS WILL
MODERATE SLIGHTLY EACH DAY...MODERATING FROM THE LOWER 70S SUNDAY TO
THE MIDDLE 70S MONDAY. LOWS SUNDAY NIGHT WILL FALL TO THE UPPER 40S
TO LOWER 50S WITH MID TO UPPER 50S EXPECTED MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...DAYBREAK TUESDAY AN UPPER TROUGH AXIS WILL
BE POSITIONED ROUGHLY ALONG THE MISSISSIPPI VALLEY...WITH SURFACE
HIGH PRESSURE SITUATED OFFSHORE OF THE CAROLINAS. EARLY TUESDAY A
WARM FRONT WILL RESIDE NORTH OF THE AREA...SO NO MENTIONABLE POP
VALUES PLANNED UNTIL TUESDAY NIGHT AS A COLD FRONT BREAKS EAST OF
THE APPALACHIAN MOUNTAINS. FRONTAL PASSAGE BASED ON AN GFS/ECMWF
CONSENSUS SOMETIME WEDNESDAY EITHER SIDE OF MIDDAY. SHRA TAPERING
OFF AND COLD AIR ADVECTION REGIME WEDNESDAY NIGHT AND A CLEARING
TREND INTO EARLY THURSDAY.
HENCE A DRY FORECAST DAY 6/7 FRI/SAT ALTHOUGH WE MAY EXPECT RETURN
FLOW NEXT WEEKEND AS THE PATTERN SHOWS A PROGRESSIVE NATURE.
TEMPERATURES 7-10 DEG F ABOVE NORMAL TUE/WED IN WARM SECTOR OF THE
APPROACHING FRONT...KNOCKED DOWN TO NORMAL DIURNAL TEMPERATURE
CURVES FOR NOVEMBER THU/FRI...THEN WARMING INTO NEXT SATURDAY.
THANKSGIVING DAY LOOKS SUNNY AND COOL. THE COLDEST MORNING IN THE
EXTENDED FORECAST LOOKS TO BE FRIDAY MORNING AS THE HIGH SETTLES
OVERHEAD BENEATH A CLEAR DOME...SO FREEZING TEMPS POSSIBLE THEN.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...MODERATE CONFIDENCE THROUGH THE VALID PERIOD DUE TO
VARYING CLOUDS TODAY...AND FOG THREAT OVERNIGHT.
VISIBLE IMAGERY CONTINUING TO SHOW MID LEVEL CLOUD COVER INLAND WITH
NOTHING AT THE COAST. AMPLE STRATOCU OFFSHORE IS NOT MAKING IT
WESTWARD...BUT STILL EXPECT SOME CU ADVECTING ONSHORE AS WINDS TURN
TO THE SE AND PERSIST THROUGH TONIGHT. INLAND TERMINALS WILL
CONTINUE BKN MID LEVEL CU CIGS THROUGH NIGHTFALL. ATTM...AM
DISCOUNTING THE ENTIRELY OVERAGGRESSIVE NAM WHICH STILL WANTS MVFR
STRATUS ALONG THE COAST...AND WILL KEEP VFR THROUGH TONIGHT. WINDS
WILL BE LIGHT...BECOMING SE AT LESS THAN 10 KTS.
GUIDANCE STILL DEPICTING WIDESPREAD IFR FOG OVERNIGHT...AND WITH
LESS CLOUD COVER NOW EXPECTED BUT SE WINDS RAISING THE TD/S...FOG
NOW APPEARS LIKELY. IF SKY CONDITIONS CLEAR AS DEPICTED ON NON-NAM
FORECAST SOUNDINGS...NEARLY IDEAL RADIATIONAL COOLING WILL EXIST
SINCE WINDS SHOULD FULLY DECOUPLE. THIS COMBINED WITH THE FACT THAT
MINS SHOULD EXCEED THEIR CROSSOVER TEMPS MEANS THAT IFR FOG IS
EXPECTED AT ALL TERMINALS. HAVE INTRODUCED IFR EVERYWHERE...AND WILL
GET MORE SPECIFIC WITH LATER UPDATES SINCE LIFR IS POSSIBLE. VERY
LIGHT WINDS CONTINUING ON SUNDAY WILL ONLY SLOWLY LIFT FOG INTO
STRATUS...ESPECIALLY INLAND...BUT VFR IS EXPECTED BY LATE MORNING.
EXTENDED OUTLOOK...LOW CONFIDENCE IN FOG MONDAY/TUESDAY MORNINGS AND
ISOLATED SHOWERS DURING THE AFTERNOONS. SHOWERS ASSOCIATED WITH A
COLD FRONT MAY IMPACT THE TERMINALS ON WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...WINDS WILL SHIFT AROUND TO THE E-SE THROUGH
THIS EVENING AS TROUGH JUST TO THE EAST OF LOCAL WATERS SHIFTS A
LITTLE FARTHER WEST THROUGH THIS EVENING BEFORE DISSIPATING BY
DAYBREAK. OVERALL WEAK HIGH PRESSURE WILL CONTINUE TO RIDGE INTO THE
CAROLINAS AS IT SHIFTS FARTHER OFF SHORE OVERNIGHT. THEREFORE EXPECT
SFC WINDS TO BECOME LIGHT WEST OR VARIABLE OVERNIGHT AROUND 5 TO 10
KTS. PATCHY CU MAY CONTINUE TO MOVE OVER THE LOCAL WATERS OR DEVELOP
ALONG THE SFC TROUGH. CAN NOT RULE OUT A SPRINKLE AS TROUGH MOVES
SLIGHTLY CLOSER TO THE COAST THIS EVENING BEFORE WEAKENING. SLIGHTLY
LONGER PERIOD E-NE SWELL COMING AROUND THE HIGH PRESSURE WILL
COMBINE WITH LOCALLY MINIMAL WIND WAVE TO PRODUCE SEAS IN THE 2 TO 3
FT RANGE MOST WATERS WITH A FEW 4 FTERS IN OUTER WATERS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...LIGHT AND VARIABLE WINDS SUNDAY WILL BECOME S
TO SW DURING THE AFTERNOON AND CONTINUE THROUGH MONDAY NIGHT.
SPEEDS OF 15 KT OR LESS ARE EXPECTED THROUGH THE PERIOD WITH SEAS
WILL OF 2 TO 4 FT.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM SATURDAY...TUESDAY THROUGH THURSDAY LOOKS UNSETTLED
AND ROUGH ON THE 0-20NM WATERS...PRIMARILY DUE TO A COLD FRONTAL
PASSAGE WEDNESDAY. PRE-FRONT SW WINDS LATE TUESDAY...AND POST-
FRONT NW WINDS LATE WED MAY BOTH REQUIRE AN ADVISORY...HENCE WE
MAY SEE AN ADVISORY FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT
BASED ON CURRENT TIMING AND STRENGTH OF THE APPROACHING FRONT.
ADDITIONALLY...WE MAY SEE A FEW TSTMS OVER THE WATERS WEDNESDAY.
THE SEA SPECTRUM TUE-THU WILL BE MARKED BY E WAVES 2-3 FEET AT 10
SECONDS...WITH GROWING SSW WIND-WAVES/BUILDING SOUTHERLY CHOP AND
SLOP. EXPECT A WIND-SHIFT TO NW WED AFTERNOON...CHANGING DIRECTION
OF THE SHORT PERIOD WAVES. THE COLD AIR ADVECTION BEHIND THE FRONT
WILL BRING NW WIND GUSTS TO 25-30 KNOTS WEDNESDAY AFTERNOON AND
NIGHT. THURSDAY OR THANKSGIVING DAY...A DAY OF IMPROVEMENT BUT A
BIT ROUGH IN THE MORNING FROM NNW WINDS...HIGHEST OFFSHORE. NEAR
SHORE CONDITIONS WILL IMPROVE THE QUICKEST EARLY THURSDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...31
LONG TERM...MJC
AVIATION...JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
126 PM EST SAT NOV 19 2011
.SYNOPSIS...
HIGH PRESSURE OVERHEAD WILL MOVE OFFSHORE THIS WEEKEND AND INTO
EARLY NEXT WEEK. TEMPERATURES WILL BEGIN TO WARM OVER THE WEEKEND
AS SOUTHERLY WINDS DEVELOP. A COLD FRONT WILL MOVE THROUGH
WEDNESDAY. COOLER WEATHER IS EXPECTED LATE NEXT WEEK AS HIGH
PRESSURE BUILDS IN.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1 PM SATURDAY...COASTAL TROUGH REMAINING JUST TO THE EAST OF
LOCAL COASTAL WATERS WITH LIGHT NORTHEAST FLOW ON WEST SIDE OF
TROUGH OVER LAND AREAS. OVERALL GRADIENT IS WEAK WITH WINDS
REMAINING 5 MPH OR LESS MOST PLACES AT THE SURFACE. RUC SOUNDINGS
SHOWING AN OVERALL WARMING AND DRYING OF THE COLUMN AT LOW LEVELS
AS WARMER AIR MAKES IT WAY IN ALOFT AND MIXING OCCURS THROUGH
TODAY. EXPECT ONLY LINGERING PATCHES OF CLOUDS THROUGH THIS
AFTERNOON. MOST AREAS WILL EXPERIENCE PARTLY TO MOSTLY SUNNY
SKIES. NE FLOW WILL CAPTURE SOME OF THE MARINE INFLUENCE BRINGING
HIGH DEWPOINT AIR IN. THE DEWPOINTS ALONG THE COAST SHOULD REACH
UP INTO THE MID 50S WHILE INLAND DEWPOINTS IN THE 30S WILL RISE
INTO THE MID 40S BY THE END OF THE DAY. WAA WILL CONTINUE WITH SW
FLOW ABOVE THE SURFACE. 850 TEMPS AROUND 4 TO 5 C THIS MORNING
WILL RISE UP TO AROUND 8C BY DAYBREAK ON SUNDAY. WILL KEEP MAX
TEMPS IN THE MID 60S
SURFACE FLOW WILL CONTINUE TO COME AROUND FROM THE NE TO E AND
EVENTUALLY SE. CLOUDS ASSOCIATED WITH COASTAL TROUGH MAY MOVE ON
SHORE THROUGH THIS EVENING AS THE TROUGH AXIS SHIFTS A LITTLE
FARTHER WEST. THIS TROUGH DISSIPATES OVERNIGHT AS HIGH PRESSURE
CONTINUES TO RIDGE BACK INTO THE CAROLINAS. OVERALL VERY WEAK
PRESSURE PATTERN EXPECTED WITH CALM WINDS EXPECTED. FOR NOW WILL
KEEP MOST CLOUDS OUT OF THE EQUATION ALLOWING FOR MORE IDEAL
RADIATIONAL COOLING AND DENSER FOG THREAT. TEMPS WILL DROP OFF BUT
WAA AND INCREASED LOW LEVEL MOISTURE WILL KEEP SFC DEWPOINTS
ALLOWING FOR LESS OF A TEMP DROP THAN PREVIOUS NIGHTS. FORECAST
LOWS WILL BE LOW TO MID 40S MOST PLACES AND CLOSER TO 50 ALONG THE
COAST.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...SURFACE RIDGE AXIS OVER THE AREA SUN SHIFTS
SOUTHEAST OF THE AREA MON. PATTERN ALOFT WILL TRANSITION FROM WEAK
RIDGING SUN TO ZONAL FLOW MON INTO MON NIGHT AS SHORTWAVE TROUGH
MOVES FROM THE SOUTHWEST INTO THE MID MISSISSIPPI VALLEY. BACKDOOR
COLD FRONT WILL STALL WELL NORTH OF THE AREA MON NIGHT. PRECIP DOES
NOT LOOK LIKE MUCH OF A CONCERN AT THIS POINT BUT INCREASING MID AND
UPPER LEVEL MOISTURE AHEAD OF AFOREMENTIONED WAVE WILL LEAD TO AN
INCREASE IN CLOUD COVER LATE MON AND MON NIGHT.
PROXIMITY TO RIDGE AXIS SUN WILL KEEP FLOW LIGHT...THOUGH GENERALLY
WITH A SOUTHERLY COMPONENT. ALONG THE COAST SEA BREEZE MAY TEMPER
HIGHS A DEGREE OR TWO. REGARDLESS TEMPERATURES ACROSS THE REGION
WILL BE ABOVE CLIMO SUN AND SUN NIGHT. SOUTHWEST FLOW BECOMES MORE
ESTABLISHED MON HELPING PUSH HIGHS INTO THE MID 70S ACROSS MUCH OF
THE AREA. INCREASE IN CLOUD COVER MON AFTERNOON MAY TEMPER HIGHS
ACROSS THE NORTHERN TIER OF COUNTIES. ABOVE CLIMO TEMPS CONTINUE MON
NIGHT WITH SOUTHWEST FLOW AND INCREASING CLOUD COVER HOLDING HIGHS
IN THE MID TO UPPER 50S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...MAIN FEATURE FOR THE PERIOD WILL BE COLD FRONT
CROSSING THE AREA WED. SURFACE LOW AND ASSOCIATED OPEN 5H WAVE WILL
TRACK NORTH OF THE AREA...MOVING INTO THE OH VALLEY TUE NIGHT. LOW
WILL BE JUST EAST OF SOUTHERN NEW ENGLAND WED MORNING WITH COLD
FRONT EXTENDING SOUTHWEST THROUGH CENTRAL NC/SC AND INTO GA. AHEAD
OF THE FRONT TUE AND TUE NIGHT WEAK SUBSIDENCE AT THE TOP OF NARROW
5H RIDGE INDUCE BY 5H TROUGH WILL HELP DRY MID LEVELS AND SUPPRESS
UPWARD MOTION. NARROW BAND OF DEEP MOISTURE MAY PRODUCE A BROKEN
LINE OF CONVECTION...BUT LIMITED INSTABILITY WILL IMPACT COVERAGE
AND INTENSITY. LOW CHC POP WED IS REASONABLE AND WILL HOLD ONTO
SLIGHT CHC FOR TUE AND TUE NIGHT BUT HAVE TRENDED DOWN A LITTLE.
SPRAWLING 5H RIDGE WILL BUILD OVER THE CENTRAL AND EASTERN CONUS THU
AND FRI. SURFACE HIGH CENTERED NORTHWEST OF THE AREA WILL ENSURE
NORTH TO NORTHEAST FLOW THU. RIDGE AXIS SHIFTS EAST FRI AND BECOMES
ELONGATED WITH NORTHEAST WINDS VEERING TO EASTERLY LATE IN THE
PERIOD. SUBSIDENCE AND DRY AIR ASSOCIATED WITH 5H RIDGE KEEPS THE
END OF THE FORECAST DRY.
AHEAD OF THE COLD FRONT TEMPERATURES WILL CONTINUE TO RUN ABOVE
CLIMO. COLD ADVECTION BEHIND THE FRONT ON WED DOES NOT LOOK AS
SIGNIFICANT AS IT HAS BEEN WITH MORE RECENT FRONTS. ALTHOUGH HIGHS
AND LOWS FALL BELOW CLIMO FOR THU/FRI NUMBERS WILL ONLY BE A FEW
DEGREES OFF CLIMO.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...MODERATE CONFIDENCE THROUGH THE VALID PERIOD DUE TO
VARYING CLOUDS TODAY...AND FOG THREAT OVERNIGHT.
VISIBLE IMAGERY CONTINUING TO SHOW MID LEVEL CLOUD COVER INLAND WITH
NOTHING AT THE COAST. AMPLE STRATOCU OFFSHORE IS NOT MAKING IT
WESTWARD...BUT STILL EXPECT SOME CU ADVECTING ONSHORE AS WINDS TURN
TO THE SE AND PERSIST THROUGH TONIGHT. INLAND TERMINALS WILL
CONTINUE BKN MID LEVEL CU CIGS THROUGH NIGHTFALL. ATTM...AM
DISCOUNTING THE ENTIRELY OVERAGGRESSIVE NAM WHICH STILL WANTS MVFR
STRATUS ALONG THE COAST...AND WILL KEEP VFR THROUGH TONIGHT. WINDS
WILL BE LIGHT...BECOMING SE AT LESS THAN 10 KTS.
GUIDANCE STILL DEPICTING WIDESPREAD IFR FOG OVERNIGHT...AND WITH
LESS CLOUD COVER NOW EXPECTED BUT SE WINDS RAISING THE TD/S...FOG
NOW APPEARS LIKELY. IF SKY CONDITIONS CLEAR AS DEPICTED ON NON-NAM
FORECAST SOUNDINGS...NEARLY IDEAL RADIATIONAL COOLING WILL EXIST
SINCE WINDS SHOULD FULLY DECOUPLE. THIS COMBINED WITH THE FACT THAT
MINS SHOULD EXCEED THEIR CROSSOVER TEMPS MEANS THAT IFR FOG IS
EXPECTED AT ALL TERMINALS. HAVE INTRODUCED IFR EVERYWHERE...AND WILL
GET MORE SPECIFIC WITH LATER UPDATES SINCE LIFR IS POSSIBLE. VERY
LIGHT WINDS CONTINUING ON SUNDAY WILL ONLY SLOWLY LIFT FOG INTO
STRATUS...ESPECIALLY INLAND...BUT VFR IS EXPECTED BY LATE MORNING.
EXTENDED OUTLOOK...LOW CONFIDENCE IN FOG MONDAY/TUESDAY MORNINGS AND
ISOLATED SHOWERS DURING THE AFTERNOONS. SHOWERS ASSOCIATED WITH A
COLD FRONT MAY IMPACT THE TERMINALS ON WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1 PM SATURDAY...COASTAL TROUGH JUST TO THE EAST OF LOCAL
WATERS KEEPING A SLIGHTLY TIGHTER GRADIENT WITH A NE FLOW OVER
OUTER WATERS UP TO 15 KTS. EXPECT THIS SURFACE TROUGH TO PUSH A
LITTLE FARTHER WEST THROUGH THIS EVENING AND DISSIPATING BY
DAYBREAK...LEAVING WEAK HIGH PRESSURE RIDGING INTO THE CAROLINAS.
THEREFORE EXPECT SFC WINDS TO SHIFT SLIGHTLY MORE EAST BEFORE
BECOMING JUST LIGHT AND VARIABLE OVERNIGHT AROUND 5 TO 10 KTS.
PATCHY CU MAY CONTINUE TO MOVE OVER THE LOCAL WATERS OR DEVELOP
ALONG THE SFC TROUGH. CAN NOT RULE OUT A SPRINKLE AS TROUGH MOVES
SLIGHTLY CLOSER TO THE COAST THIS EVENING BEFORE BREAKING UP.
SLIGHTLY LONGER PERIOD E-NE SWELL COMING AROUND THE HIGH PRESSURE
WILL COMBINE WITH LOCALLY MINIMAL WIND WAVE TO PRODUCE SEAS IN THE
2 TO 3 FT RANGE MOST WATERS. EXPECT OUTER WATERS IN THE 3 TO 4 FT
RANGE WITH SLIGHTLY GREATER WINDS THIS AFTERNOON.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...SURFACE RIDGE AXIS OVER THE WATERS ON SUN WILL
RESULT IN A LIGHT AND HIGHLY VARIABLE WIND FIELD. THE EXCEPTION WILL
BE ALONG THE COAST WHERE AFTERNOON SEA BREEZE IS LIKELY TO IMPART AN
ONSHORE COMPONENT AND A SEVERAL KT INCREASE IN WIND SPEEDS. RIDGE
AXIS SHIFTS SOUTHEAST OF THE WATERS MON WITH LIGHT SOUTH TO
SOUTHWEST FLOW SETTING UP. SPEEDS WILL BE SLIGHTLY HIGHER THAN ON
SUN...BUT NOT MUCH ABOVE 10 KT. SEAS WILL RUN 2 TO 4 FT THROUGH THE
PERIOD.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...SOUTH TO SOUTHWEST FLOW...AHEAD OF ADVANCING
COLD FRONT...TUE AND TUE NIGHT WILL INCREASE IN STRENGTH. INCREASE
IN WINDS WILL ALSO BRING ABOUT AN INCREASE IN SEAS. APPEARS AS
THOUGH THERE MAY BE A PERIOD ON WED WHERE BOTH WINDS AND SEAS FLIRT
WITH SCA THRESHOLDS. ONCE FRONT PASSES OFFSHORE FLOW WILL REMAIN
CLOSE TO SCA THRESHOLDS...POSSIBLY REQUIRING SCA THROUGH THE END OF
THE PERIOD. WEST TO NORTHWEST COMPONENT TO WIND WILL KNOCK SEAS
WITHIN 20 NM BELOW 6 FT PRETTY QUICKLY ON WED BUT SEAS WILL ON THE
CHOPPY SIDE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...III
LONG TERM...III
AVIATION...JDW
AREA FORECAST DISCUSSION
NWS NORMAN OK
1144 AM CST SAT NOV 19 2011
.UPDATE...
COLD FRONT ACROSS KANSAS IS MOVING INTO NORTHWEST OKLAHOMA RIGHT
NOW WITH BUFFALO AND MAY RANCH MESONET STATIONS HAVING TURNED TO
NORTH WINDS ALREADY. THE FRONT IS A BIT AHEAD OF SCHEDULE AND HAVE
MADE ADJUSTMENTS IN THE FORECAST FOR THIS. OVERALL... THE CURRENT
RUC SEEMS TO HAVE A GOOD HANDLE ON THE SITUATION AND LOOKED LIKE A
GOOD SOURCE TO REPOPULATE THE WIND... DEWPOINT AND TEMPERATURE
GRIDS. HAVE ALSO MADE ADJUSTMENTS TO CLOUD COVER BASED ON CURRENT
TRENDS. THE RUC AND THE LOCAL WRF MODELS SUGGEST THE POSSIBILITY
OF CONVECTION DEVELOPING ALONG THE FRONT IN NORTHEAST OKLAHOMA AND
DEVELOPING TOWARD THE NORTHEAST PORTION OF THE CWA BUT NEITHER
MODEL DEVELOPS CONVECTION IN THE CWA. WILL NOT ADD POPS TO THE
AFTERNOON PERIOD WITH THIS UPDATE BUT WILL CONTINUE TO WATCH
TRENDS BOTH HERE AND ACROSS THE FAR SOUTHEAST PORTION OF THE AREA.
&&
.PREV DISCUSSION... /ISSUED 545 AM CST SAT NOV 19 2011/
AVIATION...
MVFR CONDITIONS WILL PREVAIL THIS MORNING OVER EASTERN SITES WITH
VFR IN THE WEST. FRONT WILL MOVE THROUGH THE REGION OVERNIGHT WITH
MVFR AND POSSIBLY SOME IFR CONDITIONS DEVELOPING BEHIND THE FRONT.
PREV DISCUSSION... ISSUED 425 AM CST SAT NOV 19 2011/
DISCUSSION...
LOW CLOUDS HAVE SPREAD OVER MUCH OF THE EASTERN HALF OF THE FA THIS
MORNING AS LOW LEVEL MOISTURE CONTINUES TO INCREASE WITH PERSISTENT
SOUTHERLY FLOW. COLD FRONT APCHG NWRN KS EARLY THIS MORNING IS
EXPECTED TO SURGE SOUTHWARD TODAY AS S/W TROUGH MOVES THROUGH THE
NRN PLAINS. FRONT WILL LIKELY MOVE INTO FAR NRN PARTS OF OK THIS
AFTERNOON. THE FRONT WILL CONTINUE SOUTHWARD TONIGHT EDGING INTO
SRN PARTS OF THE FORECAST AREA BY EARLY SUNDAY MORNING...BEFORE
STALLING OUT NEAR OR JUST SOUTH OF THE RED RIVER BY SUNDAY
NIGHT/MONDAY MORNING. MOISTURE WILL CONTINUE TO INCREASE AHEAD OF
THE FRONT AND SCATTERED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE...MAINLY SOUTHEAST TONIGHT. SHOWERS AND THUNDERSTORMS
CHANCES WILL CONTINUE SUNDAY...MAINLY NEAR AND NORTH OF THE FRONT
AIDED BY ISENTROPIC LIFT AND MINOR IMPULSES MOVING THROUGH THE
SWLY FLOW ALOFT. MORE WIDESPREAD RAIN AND THUNDERSTORMS EXPECTED
MONDAY/MONDAY NIGHT AS LIFT INCREASES WITH THE APPROACH OF THE
SWRN U.S. UPPER TROUGH. HEAVY RAINFALL WILL BE
POSSIBLE...ESPECIALLY IN SOUTHERN AREAS NEAR AND JUST NORTH OF THE
STALLED FRONT. MODELS REMAIN IN FAIRLY GOOD AGREEMENT WITH THE
TIMING OF THE EXITING UPPER SYSTEM WITH THE PRECIP EXPECTED TO
COME TO AN END ON TUESDAY. DRY WEATHER IS THEN EXPECTED THROUGH
MID WEEK WITH RAIN CHANCES RETURNING LATE IN THE WEEK WITH THE
APPROACH OF ANOTHER UPPER TROUGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 72 44 49 41 / 10 10 10 20
HOBART OK 73 39 51 42 / 0 0 0 10
WICHITA FALLS TX 77 54 61 50 / 10 10 10 30
GAGE OK 73 29 47 34 / 0 0 0 0
PONCA CITY OK 71 34 44 33 / 10 10 10 10
DURANT OK 76 65 77 55 / 10 30 30 50
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1010 AM PST Sat Nov 19 2011
.SYNOPSIS...
A cold front boundary moving in from the Northeast and will
produce cooler and drier weather just North of the largest threat
of snow moving into eastern Washington and north central Idaho
today. Following a break in the weather Sunday, unsettled weather
will return for most of next week with most of the snow expected
to occur near the cascades and northern mountains.
&&
.DISCUSSION...
The forecast has been updated to increase snow accumulations over
the Spokane and Coeur D`Alene areas this afternoon. Morning radar
imagery shows a band of light to moderate snow entering the metro
area from the south. Warm advection in the 850-700mb layer appears
to be occurring over southeast Washington and adjacent portions of
north Idaho. Radar imagery suggests a small scale/low level
circulation enhancing the band of snow this morning as it moves
into the metro area. Spotter reports over the Palouse and traffic
cameras suggest a quick 1 to 3 inches of snow occurring with this
band. The numerical models have not resolved this small band and
there is a good deal of uncertainty on how far to the northeast it
will move this afternoon. I would expect that it would weaken or
stall over Spokane/Kootenai counties this afternoon since the more
organized circulation at 500mb remains well west of this small
snowband. As of 10am, water vapor imagery suggests that the
vorticity center with the more organized 500mb wave is around over
the southern or central Cascades. This feature will move into
eastern Washington this afternoon and early this evening, and will
likely produced more organized bands of snow somewhere between
Spokane and Lewiston. The latest RUC runs hit the northern Palouse
with another couple inches of snow by early evening. A winter
weather advisory may be needed for afternoon/evening snow
accumulations once the axis of heaviest snowfall can be
determined. /GKoch
&&
.AVIATION...
18z TAFS: Small scale bands of light to moderate snow will bring a
wide range of visibility and ceiling conditions to eastern
Washington and north Idaho through late evening. Snow bands are
not being resolved particularly well in the Spokane area, so the
18z TAFS were based on satellite and radar extrapolations which
may not be very good beyond 21z. Look for a lot of ammendments
today as the environment is fairly unstable and will produce some
highly localized bands of snow. Light winds, fresh precipitation
and high low level relative humidity will bring the potential for
low fog and stratus late Saturday night into Sunday morning.
Ceiling and visibility forecasts in this type of environment is
tough so forecast confidence is low. /GKoch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 28 12 30 16 37 31 / 80 20 10 20 50 70
Coeur d`Alene 26 12 30 14 37 29 / 60 20 10 20 60 70
Pullman 30 17 32 18 37 32 / 70 40 10 10 30 50
Lewiston 35 22 37 26 44 34 / 60 50 10 10 20 40
Colville 30 10 29 13 33 29 / 10 10 10 20 60 70
Sandpoint 25 10 29 12 35 30 / 10 20 20 20 70 70
Kellogg 25 15 28 16 33 27 / 70 30 20 10 50 70
Moses Lake 31 10 32 17 38 26 / 60 10 10 10 30 60
Wenatchee 32 13 31 23 36 29 / 40 10 10 30 40 70
Omak 32 6 31 14 33 22 / 10 10 10 20 60 70
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
225 PM CST SAT NOV 19 2011
.SHORT TERM...
1156 AM CST SAT NOV 19 2011
FORECAST IS GENERALLY ON TRACK. HAVE MADE SOME CHANGES BASED ON
LATEST RADAR...OBSERVATIONS...AND SHORT TERM MODEL GUIDANCE.
STALLED FRONTAL BOUNDARY CURRENTLY LIES FROM MARSHFIELD WI TO LA
CROSSE WI TO NEAR MASON CITY WITH AIR IN THE 30S TO ITS NORTH AND
MID 40S TO ITS SOUTH. DMX RADAR THIS MORNING HAD AN ERUPTION OF
DRIZZLE OVER NORTH-CENTRAL IOWA...MAINLY N OF HIGHWAY 20...AND
FREEZING DRIZZLE BACK IN NWRN IA IN THE COLDER AIR. THIS WAS IN WARM
CLOUD AREA SEEN ON IR SATELLITE IMAGERY /0 TO -10C/ LINING UP ON
THE NWRN EDGE OF THE FORECAST AREA FROM MEDFORD TO ROCHESTER MN TO
NEAR KFSD. THIS LACK OF UPPER CLOUD AND ONLY SURFACE-BASED 2KM
SATURATION WILL LEAD TO ALL LIQUID CLOUDS WITH VERTICAL MOTION
CAUSING DRIZZLE THIS AFTERNOON.
LATEST MESO MODELS AND RUC SUGGEST WARM AIR ADVECTION TO KICK IN
THIS AFTERNOON AS 295K SURFACE HAS GOOD UPGLIDE ISENTROPICALLY.
THIS WAS LEADING TO THE WIDESPREAD DRIZZLE FORMATION OVER IA AND
ECHO INCREASE OVER THE ENTIRE AREA IN THE LAST HOURS. BELIEVE
DRIZZLE WILL DOMINATE THE AREA SOUTH OF THE DEEP COLD IR CLOUD
TOPS THIS AFTERNOON AND THUS HAVE UPDATED TO HAVE THE ENTIRE AREA
GET WET WITH DRIZZLE. IN THE VERY NORTHWEST FORECAST AREA...KRST-
KMDZ..THE DEEP ICE CLOUD WILL TRY TO WORK SOUTHEAST AND PRVIDE SNOW
CHANCES LATE WITH DEEP CLOUD PROCESSES. BOTTOM LINE...A CLOUDY
AFTERNOON WITH DRIZZLE...AND A MIX AT TIMES LATER OF SNOW IN THE
NWRN FORECAST AREA.
THIS EVENING COULD GET INTERESTING FOR THE AREAS IMMEDIATELY ON
THE SOUTHEAST EDGE OF THE DEEP CLOUD. WE HAVE SOME CONCERN FOR
FREEZING DRIZZLE AS THE SURFACE LOW...NOW NEAR KANSAS CITY
MO...WILL TRACK EAST AND DRAG COLDER AIR IN FROM THE NW. THUS...DRIZZLE
MAY BECOME FREEZING DRIZZLE ALONG AND NORTH OF HIGHWAY 10 IN
WI...AND 3-4 COUNTIES EAST OF I-35 IN MN AND IA. IF DEEP CLOUD IS
IN PLACE...PRECIPITATION WILL BE SNOW. BUT WITH CURRENT SCENARIO...AND
WARM CLOUD TOPS /0 TO -10C/ IN PLACE...FZDZ COULD CAUSE SOME ICE
ACCUMULATIONS AS THE LIFT DIMINISHES AND THE STORM SHIFTS AWAY. WE
HAVE INCLUDED THIS IN THE LATEST GRIDS/FORECASTS...AND MAY HAVE TO
CONSIDER AN ADVISORY SHOULD CONFIDENCE GROW IN ACCUMS OF ICE. IT
WOULD NOT BE MUCH...BUT ENOUGH TO IMPACT TRAVELERS.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
225 AM CST SAT NOV 19 2011
A SHORT WAVE TROUGH IS EXPECTED TO LIFT OUT OF THE DESERT
SOUTHWEST AND TRAVEL TOWARD THE OHIO RIVER VALLEY EARLY IN THE
PERIOD. THE SURFACE LOW IS ALSO EXPECTED TO TRACK TROUGH THE OHIO
VALLEY BUT THERE IS SOME DIFFERENCES AS TO HOW FAR NORTH THE
PRECIPITATION SHIELD WILL GET. THE ECMWF IS THE FARTHEST NORTH AND
JUST BRUSHES THE SOUTHERN PARTS OF THE FORECAST AREA WHILE THE GFS
AND 19.00Z GEM ARE WELL TO THE SOUTH. WILL STAY WITH THE MODEL
CONSENSUS GRIDS WHICH KEEPS THIS PRECIPITATION SOUTH OF THE AREA.
AFTER THAT...IT LOOKS LIKE IT WILL BE LATE IN THE WEEK BEFORE THE
NEXT SYSTEM COMES IN AND BRINGS A CHANCE FOR SOME RAIN FRIDAY.
&&
.AVIATION...THROUGH 18Z SUNDAY
1156 AM CST SAT NOV 19 2011
TAF FORECASTS WERE ON TRACK AND HAVE MADE LITTLE CHANGE WITH 18Z.
CEILINGS WILL SLOWLY COME DOWN INTO IFR TODAY AS LOW PRESSURE AND
LIFT HEAD INTO THE TAF AREA. WIDESPREAD DZ WILL OCCUR AND SHOULD
TEMPERATURES FALL IN THE EARLY EVENING AND ENOUGH DRIZZLE
REMAIN...SOME FZDZ IS POSSIBLE NEAR KRST. ICING WOULD BE ONLY A
FEW HUNDRETHS...BUT POSSIBLE. IFR CEILINGS WILL BE PESKY TO MOVE
OUT...ESPECIALLY AT KRST...SUNDAY MORNING. LATER FORECASTS CAN
REFINE THIS TIMING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...PRELIMINARY HEADLINES FOR THIS
EVENING BASED ON FREEZING DRIZZLE AND LIGHT ICE ACCUMULATION.
223 PM CST SAT NOV 19 2011
WI...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT CST
TONIGHT FOR WIZ017-029-032>034.
MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT CST
TONIGHT FOR MNZ079-086>088-094-095.
IA...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT CST
TONIGHT FOR IAZ008-009-018-019.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...04
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1157 AM CST SAT NOV 19 2011
.SHORT TERM...
1156 AM CST SAT NOV 19 2011
FORECAST IS GENERALLY ON TRACK. HAVE MADE SOME CHANGES BASED ON
LATEST RADAR...OBSERVATIONS...AND SHORT TERM MODEL GUIDANCE.
STALLED FRONTAL BOUNDARY CURRENTLY LIES FROM MARSHFIELD WI TO LA
CROSSE WI TO NEAR MASON CITY WITH AIR IN THE 30S TO ITS NORTH AND
MID 40S TO ITS SOUTH. DMX RADAR THIS MORNING HAD AN ERUPTION OF
DRIZZLE OVER NORTH-CENTRAL IOWA...MAINLY N OF HIGHWAY 20...AND
FREEZING DRIZZLE BACK IN NWRN IA IN THE COLDER AIR. THIS WAS IN WARM
CLOUD AREA SEEN ON IR SATELLITE IMAGERY /0 TO -10C/ LINING UP ON
THE NWRN EDGE OF THE FORECAST AREA FROM MEDFORD TO ROCHESTER MN TO
NEAR KFSD. THIS LACK OF UPPER CLOUD AND ONLY SURFACE-BASED 2KM
SATURATION WILL LEAD TO ALL LIQUID CLOUDS WITH VERTICAL MOTION
CAUSING DRIZZLE THIS AFTERNOON.
LATEST MESO MODELS AND RUC SUGGEST WARM AIR ADVECTION TO KICK IN
THIS AFTERNOON AS 295K SURFACE HAS GOOD UPGLIDE ISENTROPICALLY.
THIS WAS LEADING TO THE WIDESPREAD DRIZZLE FORMATION OVER IA AND
ECHO INCREASE OVER THE ENTIRE AREA IN THE LAST HOURS. BELIEVE
DRIZZLE WILL DOMINATE THE AREA SOUTH OF THE DEEP COLD IR CLOUD
TOPS THIS AFTERNOON AND THUS HAVE UPDATED TO HAVE THE ENTIRE AREA
GET WET WITH DRIZZLE. IN THE VERY NORTHWEST FORECAST AREA...KRST-
KMDZ..THE DEEP ICE CLOUD WILL TRY TO WORK SOUTHEAST AND PRVIDE SNOW
CHANCES LATE WITH DEEP CLOUD PROCESSES. BOTTOM LINE...A CLOUDY
AFTERNOON WITH DRIZZLE...AND A MIX AT TIMES LATER OF SNOW IN THE
NWRN FORECAST AREA.
THIS EVENING COULD GET INTERESTING FOR THE AREAS IMMEDIATELY ON
THE SOUTHEAST EDGE OF THE DEEP CLOUD. WE HAVE SOME CONCERN FOR
FREEZING DRIZZLE AS THE SURFACE LOW...NOW NEAR KANSAS CITY
MO...WILL TRACK EAST AND DRAG COLDER AIR IN FROM THE NW. THUS...DRIZZLE
MAY BECOME FREEZING DRIZZLE ALONG AND NORTH OF HIGHWAY 10 IN
WI...AND 3-4 COUNTIES EAST OF I-35 IN MN AND IA. IF DEEP CLOUD IS
IN PLACE...PRECIPITATION WILL BE SNOW. BUT WITH CURRENT SCENARIO...AND
WARM CLOUD TOPS /0 TO -10C/ IN PLACE...FZDZ COULD CAUSE SOME ICE
ACCUMULATIONS AS THE LIFT DIMINISHES AND THE STORM SHIFTS AWAY. WE
HAVE INCLUDED THIS IN THE LATEST GRIDS/FORECASTS...AND MAY HAVE TO
CONSIDER AN ADVISORY SHOULD CONFIDENCE GROW IN ACCUMS OF ICE. IT
WOULD NOT BE MUCH...BUT ENOUGH TO IMPACT TRAVELERS.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
225 AM CST SAT NOV 19 2011
A SHORT WAVE TROUGH IS EXPECTED TO LIFT OUT OF THE DESERT
SOUTHWEST AND TRAVEL TOWARD THE OHIO RIVER VALLEY EARLY IN THE
PERIOD. THE SURFACE LOW IS ALSO EXPECTED TO TRACK TROUGH THE OHIO
VALLEY BUT THERE IS SOME DIFFERENCES AS TO HOW FAR NORTH THE
PRECIPITATION SHIELD WILL GET. THE ECMWF IS THE FARTHEST NORTH AND
JUST BRUSHES THE SOUTHERN PARTS OF THE FORECAST AREA WHILE THE GFS
AND 19.00Z GEM ARE WELL TO THE SOUTH. WILL STAY WITH THE MODEL
CONSENSUS GRIDS WHICH KEEPS THIS PRECIPITATION SOUTH OF THE AREA.
AFTER THAT...IT LOOKS LIKE IT WILL BE LATE IN THE WEEK BEFORE THE
NEXT SYSTEM COMES IN AND BRINGS A CHANCE FOR SOME RAIN FRIDAY.
&&
.AVIATION...THROUGH 18Z SUNDAY
1156 AM CST SAT NOV 19 2011
TAF FORECASTS WERE ON TRACK AND HAVE MADE LITTLE CHANGE WITH 18Z.
CEILINGS WILL SLOWLY COME DOWN INTO IFR TODAY AS LOW PRESSURE AND
LIFT HEAD INTO THE TAF AREA. WIDESPREAD DZ WILL OCCUR AND SHOULD
TEMPERATURES FALL IN THE EARLY EVENING AND ENOUGH DRIZZLE
REMAIN...SOME FZDZ IS POSSIBLE NEAR KRST. ICING WOULD BE ONLY A
FEW HUNDRETHS...BUT POSSIBLE. IFR CEILINGS WILL BE PESKY TO MOVE
OUT...ESPECIALLY AT KRST...SUNDAY MORNING. LATER FORECASTS CAN
REFINE THIS TIMING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
225 AM CST SAT NOV 19 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...04
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1149 AM CST SAT NOV 19 2011
.UPDATE...WIDESPREAD DRIZZLE ONGOING THIS MORNING OVER IOWA AND SOUTHWEST
WISCONSIN IS ASSOCIATED WITH SATURATED LAYER AND ISENTROPIC LIFT IN
THE MID LEVELS...AS SEEN ON 290-295 K SURFACES IN LATEST RUC RUN.
WARM AIR ADVECTION OVER SOUTHERN WISCONSIN WILL CONTINUE INTO LATE
AFTERNOON...WHILE MOISTURE INCREASES IN THE AREA AS WELL.
THUS...INCREASED POPS FOR THIS AFTERNOON...BRINGING LIKELY VALUES TO
ALL BUT SOUTHERNMOST COUNTIES BY 21Z.
&&
.AVIATION/18Z TAFS/...CIGS STILL EXPECTED TO LOWER TO MVFR THIS
AFTERNOON...POSSIBLY IFR AT TIMES THIS EVENING AND INTO THE NIGHT
AS LOW PRESSURE MOVES THROUGH. AREAS OF DRIZZLE ALSO EXPECTED
DURING THIS TIME...WITH A FEW SHOWERS ALSO POSSIBLE. SOUTHERLY
WIND WILL EVENTUALLY SHIFT TO WEST BY AROUND MIDNIGHT...THEN
NORTHERLY BY DAYBREAK AS THE LOW MOVES EAST. LOOKS LIKE MVFR CIGS
MAY HOLD ON THROUGH SUNDAY MORNING...MAYBE INTO THE AFTERNOON IN
THE EAST.
&&
.PREV DISCUSSION... /ISSUED 304 AM CST SAT NOV 19 2011/
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM.
A COLD FRONT STRETCHES FROM NORTHWEST WISCONSIN...BACK SOUTHWEST
ACROSS IOWA INTO NORTHERN KANSAS EARLY THIS MORNING. A LOW
PRESSURE SYSTEM WILL MOVE QUICKLY UP ALONG THIS FRONT OUT OF
KANSAS BY MID DAY AND TRACK ACROSS THE MIDDLE OF THE FORECAST AREA
LATE THIS AFTERNOON AND EARLY THIS EVENING. THE CENTER OF THE LOW
SHOULD TRACK PRETTY CLOSE TO MADISON...OR BETWEEN MADISON AND
WISCONSIN DELLS.
FAIRLY DEEP WARM ADVECTION AHEAD OF THE LOW KICKS IN THIS MORNING
AND AFTERNOON...ACCOMPANIED BY DECENT UVV FROM A SHORT WAVE
TRACKING ACROSS NORTHERN MN AND WI. THIS PRODUCES A NICE FOCUSED
AREA OF Q-VECTOR CONVERGENCE THAT MOVES THROUGH THE AREA BETWEEN
ABOUT 18-01Z TODAY. MOISTURE SOUTH OF THE LOW TRACK IS FAIRLY
SHALLOW AND PRECIP STILL LOOKS CHCY...ESPECIALLY WHEN VIEWING THE
QPF OUTPUT OF THE NCEP WRF-NMM. AMOUNTS SHOULD BE SPLOTCHY AND
LIGHT.
NORTH OF THE LOW...ACROSS THE NW AND NRN CWA...WILL KEEP THE
LIKELY POPS GOING. AS THE FORCING PUSHES EAST QUICKLY THIS
EVENING...THE ISENTROPIC DOWNGLIDE IS PRETTY IMPRESSIVE AND SHOULD
HELP TO SHUT THINGS DOWN QUICKLY. DRY AIR PUSHES IN ALONG WITH
COLDER TEMPS. THE PRECIP SHOULD BE GONE BEFORE ANY TEMPS DROP
BELOW FREEZING.
SHORT TERM...SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE
MEDIUM TO HIGH.
HIGH PRESSURE IS EXPECTED TO SHIFT EAST ACROSS THE REGION SUNDAY
AND SUNDAY NIGHT...WITH ANOTHER HIGH TO THE WEST SLOWLY MOVING
EAST THROUGH THE REGION MONDAY AND MONDAY NIGHT. NEARLY ZONAL
UPPER LEVEL FLOW DEPICTED BY MODELS. SOME MID LEVEL CLOUDS SHOULD
PUSH NORTHEAST INTO THE AREA SUNDAY AND SUNDAY NIGHT...LINGERING
INTO MONDAY BEFORE SHIFTING OFF TO THE EAST.
MODELS HAVE A WEAK VORTICITY MAXIMUM SHIFTING THROUGH THE AREA
MONDAY...WITH THE GFS AND CANADIAN MODELS SHOWING LIGHT QPF ACROSS
PORTIONS OF THE AREA. THE NAM AND ECMWF ARE DRY WITH THIS FEATURE.
GFS SHOWING MORE SATURATION IN THE LOW LEVELS THAN THE NAM AS
WELL. FOR NOW...WILL KEEP FORECAST DRY GIVEN UNCERTAINTY AMONG
THE MODELS WITH MOISTURE FIELDS MONDAY.
TEMPERATURES WILL REMAIN NEAR SEASONAL NORMALS DURING THIS
PERIOD...WITH HIGHS WARMING INTO THE MID 40S MONDAY...FROM THE
LOWER 40S SUNDAY. LOWS IN THE UPPER 20S TO MID 30S SUNDAY NIGHT
AND MONDAY NIGHT SEEM REASONABLE.
LONG TERM...TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
ECMWF AND GFS SHOWING SOME DIFFERENCES WITH LOW PRESSURE MOVING
NORTHEAST INTO THE MID MISSISSIPPI RIVER VALLEY AND TO THE
NORTHEAST TUESDAY AND TUESDAY NIGHT. THE ECMWF TAKES THE LOW FROM
SOUTHWEST MISSOURI TO SOUTHERN INDIANA TUESDAY...THEN QUICKLY EAST
NORTHEAST OF THERE TUESDAY NIGHT. SOUTHERN STREAM SHORTWAVE TROUGH
MOVES NORTHEAST AND CLIPS THE AREA. THIS SYSTEM CLIPS THE
SOUTHEAST HALF OF THE AREA WITH LIGHT QPF.
THE GFS IS FURTHER SOUTHEAST OF THIS TRACK...AND ANY QPF WITH
THIS SYSTEM MISSES THE AREA. BOTH THE ECMWF AND GFS SHOW SPLIT
UPPER LEVEL FLOW...WITH SHORTWAVE TROUGHS IN THE NORTHERN AND
SOUTHERN STREAMS GRADUALLY MERGING WELL EAST OF THE AREA BY 12Z
WEDNESDAY. WILL CONTINUE TO MENTION LOW POPS IN THE FAR SOUTHEAST
FOR TUESDAY. THESE SYSTEMS TEND TO SHIFT FURTHER TO THE NORTHWEST
WITH TIME...SO HIGHER POPS IN FUTURE FORECASTS MAY BE POSSIBLE.
ECMWF/GFS THEN IN FAIR AGREEMENT WITH UPPER LEVEL RIDGE SHIFTING
THROUGH THE REGION WEDNESDAY THROUGH THANKSGIVING DAY...WITH A
DEEP UPPER TROUGH FORMING IN THE SOUTHERN ROCKIES/SOUTHERN HIGH
PLAINS FRIDAY. THIS ALLOWS HIGH PRESSURE TO PASS SOUTH OF THE
REGION WEDNESDAY...WITH WARM AIR ADVECTION KICKING IN
WEDNESDAY...AND ESPECIALLY THANKSGIVING DAY AND FRIDAY. QUIET
WEATHER IS EXPECTED AT THIS TIME.
TEMPERATURES WILL WARM ABOVE SEASONAL NORMALS AS WELL WITH THE
WARM AIR ADVECTION. 925MB TEMPERATURES SHOULD INCREASE TO 9 TO 10
DEGREES CELSIUS THANKSGIVING DAY AND FRIDAY WITH GOOD MIXING.
THUS...HIGHS TO AT LEAST THE MID 50S SEEM REASONABLE FOR THIS
PERIOD.
AVIATION/12Z TAFS/...
LOW PRESSURE WILL BRING SOME SHOWERS TO SOUTHERN WISCONSIN THIS
AFTERNOON AND EVENING...DIMINISHING QUICKLY FROM WEST TO EAST BY
AROUND MIDNIGHT TONIGHT. WARM...MOIST ADVECTION WILL BRING
GRADUALLY LOWERING CIGS THIS AFTERNOON. THE SOUTHEAST TAF SITES
SHOULDN/T GET BELOW MVFR. BUT MADISON WILL BE CLOSER TO THE LOW
CENTER AND THIS SHOULD ALLOW FOR A PERIOD OF IFR CIGS LATER THIS
AFTERNOON AND EVENING. DRY AIR PUSHES IN OVERNIGHT AND WILL
IMPROVE CONDITIONS BY SUNDAY MORNING.
MARINE...
BRISK SOUTH WINDS AHEAD OF AN APPROACHING LOW PRESSURE CENTER
EXPECTED TO TRACK THROUGH SOUTH CENTRAL WISCONSIN THIS EVENING
WILL RESULT IN SMALL CRAFT ADVISORY CONDITIONS TODAY THROUGH ABOUT
MIDNIGHT TONIGHT. WEAKER WESTERLY WINDS BEHIND THE LOW WILL HELP
TO DIMINISH WAVES QUICKLY OVERNIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643>646.
&&
$$
UPDATE...WIMBERLEY/DDV
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
SUNDAY THROUGH FRIDAY...WOOD