Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 01/09/12
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
305 PM MST SAT JAN 7 2012
.SHORT TERM /TONIGHT THROUGH MONDAY/...
LATEST MOSAIC IMAGERY SHOWING LARGE BAND OF SNOW MOVING ACROSS
BOOKCLIFFS THEN EASTWARD ALONG INTERSTATE 70 TOWARDS GLENWOOD
SPRINGS AND EAGLE. CDOT WEBCAMS ALSO SHOWING PLENTY OF SNOW ALONG
THE CORRIDOR. CROSS-SECTIONS INDICATE RATHER LARGE AREA OF
CONDITIONAL SYMMETRIC INSTABILITY MATCHING UP WITH THIS BAND WHICH
WOULD EXPLAIN THE RAPID SNOW ACCUMULATIONS AT THE SFC DUE TO SOME
SLANTWISE CONVECTION. IF THE BAND STAYS TOGETHER AND CONTINUES TO
DROP SWRD...SOME QUICK ACCUMULATIONS ARE POSSIBLE OVER GRASSY
SURFACES OVER GRAND VALLEY AND AREAS SOUTH. HAVING SAID THAT...MODELS
DO KEEP THIS BAND TO OUR NORTH WITH SOME SLOW SWRD DRIFT THROUGH
THE AFTN AND EVENING. NORTH OF THIS AREA...SNOW CONTINUES TO FALL
OVER AND NEAR CRAIG...HAYDEN AND MEEKER. HILITES APPEAR TO BE ON
TRACK WITH SOME CONCERN REMAINING FOR THE UNCOMPAGHRE PLATEAU AND
NRN SAN JUANS AS RUC AND HRRR SHOW SOME DEVELOPMENT OVER THAT
AREA. OF COURSE...18Z NAM SHOWS SOME PRECIP BUT NOT ENOUGH TO
WARRANT ANY ADVISORIES. WILL NOT PULL THE TRIGGER YET BUT WILL
KEEP AN EYE ON WEBCAMS...RADAR...SATELLITE AND LOCAL SNOW REPORTS.
SFC COLD FRONT MOVED THROUGH AREA QUICKER THAN EXPECTED AND IS
CLEARLY SEEN ON WATER VAPOR AND IR IMAGERY MOVING OVR SERN CO AND
NRN NM. THE UPPER LEVEL TROF AND UPPER LOW REMAIN OVER NERN UT
ATTM AND ARE STILL EXPECTED TO MOVE OVER THE REGION THIS AFTN INTO
TONIGHT CAUSING MORE SNOWFALL. THUS...MADE LITTLE TO NO CHANGE FOR
OVERNIGHT FORECAST. SINCE SPEED OF SYSTEM HAS INCREASED
SOMEWHAT...AGREE WITH PREVIOUS THINKING THAT HILITES MAY HAVE TO
BE TAKEN DOWN EARLY PROBABLY NEARER TO EARLY SUNDAY MORNING. WILL
LEAVE AS IS FOR NOW.
BY SUNDAY...MOSTLY SUNNY SKIES FOR AREAS N AND CLEARING SKIES FOR
THE SOUTH. TEMPS WILL RUN NEAR NORMAL FOR THIS TIME OF YEAR...OR
ABOUT 10 DEGREES COOLER THAN SEEN THIS PREVIOUS WEEK. HIGH
PRESSURE WILL BUILD IN AND PERSIST THROUGH MID-WEEK.
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/
EASTERN UTAH AND WESTERN COLORADO WILL BE UNDER THE INFLUENCE OF AN
UPPER RIDGE MONDAY NIGHT AND TUESDAY...SQUEEZED BETWEEN A WRAPPED UP
SOUTHERN PLAINS LOW AND THE NEXT TROF ARRIVING OUT OF THE NORTHEAST
PACIFIC. AS SUCH THE DRY WEATHER WILL CONTINUE OVER THIS PERIOD WITH
THE WARMING ALOFT HELPING TO ENFORCE THE LOW LEVEL
INVERSIONS...ESPECIALLY IN AREAS WITH THE NEWER SNOW COVER AND DID
DIRECT TEMPERATURES TOWARD THE LOWER END OF GUIDANCE. BEYOND THIS
PERIOD CONFIDENCE CONTINUES TO WANE WITH DIFFERING MED RANGE MODEL
SOLUTIONS RELATED TO PROGRESSION OF THE WESTERN TROF. THE
DIFFERENCES ARE MOSTLY CENTERED AROUND THE EVOLUTION OF AN UPPER LOW
OVER THE SOUTHWEST CORNER OF THE CONUS AS ENERGY IN THE TROF SPLITS.
THE OPERATIONAL GFS SOLUTION IS SLOWER TO ACHIEVE THIS SPLIT WHICH
CONFLICTS WITH SOME OF IT/S MEMBERS AND WITH A REFLECTION OF A LOW
OFF THE SOCAL COAST IN THE H5 MEAN SOLUTION. THIS SLOWER SOLUTION
WOULD BE A WETTER SOLUTION AND IMPACT MORE OF THE CWA. FOR NOW
FORECAST CONTINUES TO LEAN AWAY FROM THIS TOWARD THE EURO WITH A
MORE NORTHERLY FLOW DOMINATING TUESDAY NIGHT INTO WEDNESDAY AS A
CLIPPER TYPE SYSTEM DROPS THROUGH THE NORTHERN PLAINS. THIS WOULD
BRING SOME OROGRAPHICS AND WEAK DYNAMICS TO THE CENTRAL AND NORTHERN
MOUNTAINS FOR A SLIGHT CHANCE OF SNOW. BEHIND THIS REX BLOCK SETS UP
IN THE WEST WITH DRY AND ABOVE NORMAL TEMPERATURES RETURNING TO THE
CWA FOR THE LAST HALF OF THE WEEK.
.AVIATION...
CONVECTIVELY DRIVEN SNOW CONTINUES ACROSS THE CENTRAL CWA...AND WILL
BE DROPPING SLOWLY SOUTH THROUGH THE EVENING AS THE MAIN SYSTEM
DROPS SOUTH OF THE GREAT BASIN. MVFR TO IFR FLIGHT CATEGORIES
CONTINUE ACROSS MUCH OF THE UPPER COLORADO RIVER BASIN INCLUDING THE
EGE AND RIL TERMINALS WHERE MODERATE SNOW BANDING PERSISTS. SLIGHT
IMPROVEMENT TO MORE WIDESPREAD MVFR AND POCKETS OF VFR IS EXPECTED
THROUGH THE EVENING HOURS AS THE MAIN DYNAMICS OF THE STORM SHIFT
SOUTH. KASE WILL EXPERIENCE LIFR/IFR CONDITIONS IN A FAVORABLE
NORTHWEST FLOW THIS EVENING WITH IMPROVEMENT EXPECTED AFTER
MIDNIGHT. MOUNTAIN OBSCURATION CAN BE EXPECTED TO PERSIST AS WELL
THROUGH THE EARLY MORNING HOURS. THE LOWER VALLEY TERMINALS OF MTJ
AND GJT LOOK TO PREVAIL AT VFR CONDITIONS THROUGH MUCH OF THIS STORM
PASSAGE...BUT TEMPORARY MVFR CONDITIONS COULD BE REALIZED AROUND THE
07/22Z-08/02Z TIME FRAME WHEN LIFT LOOKS TO BE ENHANCED OVER THIS
AREA.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL NOON MST SUNDAY FOR ZONES 002>005-
007>010-012-013.
UT...WINTER WEATHER ADVISORY UNTIL NOON MST SUNDAY FOR ZONE 023.
&&
$$
SHORT TERM...TGR
LONG TERM....15
AVIATION.....15
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
409 AM EST SAT JAN 7 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN CENTERED SOUTH OF THE AREA INTO EARLY
NEXT WEEK AS A WEAK COLD FRONT SAGS INTO THE AREA FROM THE NORTH
SUNDAY AND MONDAY. HIGH PRESSURE WILL TEMPORARILY BUILD ACROSS THE
AREA TUESDAY BEFORE LOW PRESSURE AND ITS TRAILING COLD FRONT
IMPACT THE REGION WEDNESDAY. HIGH PRESSURE WILL EVENTUALLY BUILD
FROM THE WEST THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
GOES-EAST FOG IMAGERY AND SURFACE OBSERVATIONS INDICATE AN
EXPANDING AREA OF DENSE FOG WITH ORIGINS FROM THE GULF OF MEXICO
IS RAPIDLY EXPANDING NORTH/NORTHEAST ACROSS NORTHERN FLORIDA AND
FAR SOUTHERN GEORGIA EARLY THIS MORNING. THE LEADING EDGE OF THE
FOG BANK IS MOVING NORTHEAST AROUND 15 KT AND TIMED TO REACH THE
ALTAMAHA RIVER JUST BEFORE SUNRISE. RUC VISIBILITY PROGS APPEAR TO
HAVE INITIALIZED THE POSITIONING OF THE FOG THE BEST AND SHOWS
VISIBILITIES OF 1/4 MILE OR LESS REACHING AS FAR NORTH AS THE
METTER-PEMBROKE-RICHMOND HILL CORRIDOR BY 9 AM. THIS SEEMS QUITE
REASONABLE GIVEN HOW THE FOG BANK IS EVOLVING WITH TIME. PLAN TO
INTRODUCE AREAS OF FOG IN THE GRIDS TO ACCOUNT FOR CURRENT
TRENDS...BUT A DENSE FOG ADVISORY MAY VERY WELL BE NEEDED PRIOR TO
DAYBREAK FOR THE SOUTHERN PORTIONS OF THE FORECAST AREA. IT
APPEARS DENSE FOG WILL REMAIN JUST SOUTH OF THE SAVANNAH METRO
AREA...BUT THIS WILL BE WATCHED CAREFULLY OVER THE NEXT FEW HOURS.
A POTENT SOUTHERN STREAM SHORTWAVE WILL PASS SOUTH OF THE REGION
TODAY AS A WEAK COLD FRONT APPROACHES FROM THE NORTH. THERE MAY BE
JUST ENOUGH WEAK ISENTROPIC ASSENT ALONG THE 295-300K SURFACES TO
SUPPORT ISOLATED SHOWERS ACROSS PARTS OF SOUTHEAST GEORGIA FROM
LATE MORNING THROUGH MID-LATE AFTERNOON SO WILL SLIGHT CHANCE POPS
WILL BE MAINTAINED FOR AREAS ROUGHLY SOUTH OF I-16 TODAY. THIS
SCENARIO IS WELL SUPPORTED BY THE LATEST SREF MEAN AS WELL AS
SEVERAL MEMBERS OF THE HIGHER RESOLUTION MODEL SUITE INCLUDING THE
H3R AND 4KM-WRF. WEAK WARM AIR ADVECTION WILL SUPPORT ANOTHER
WARM DAY FOR EARLY JANUARY WITH HIGHS TOPPING OUT AROUND 70 FOR
MOST LOCATIONS AWAY FROM THE BEACHES. THE COLDER SHELF WATERS WILL
KEEP BEACH LOCATIONS CONSIDERABLY COOLER WITH THE NAM/GFS BASED
GUIDANCE PACKAGES FOR FOLLY BEACH...HILTON HEAD AND FORT PULASKI
FAVORING ANOTHER DAY WITH HIGHS STRUGGLING TO REACH 60 DEGREES.
CIRRUS MOVING OVER SOUTHERN SOUTH CAROLINA THIS MORNING WILL CLEAR
OUT BY SUNRISE...BUT THE INCOMING FOG BANK WILL LIKELY LEAD TO LOW
CIGS ACROSS MUCH OF SOUTHEAST GEORGIA THROUGH AT LEAST MID-
MORNING. THE FOG IS EXPECTED TO LIFT INTO A CUMULUS FIELD BY MID-
LATE MORNING AS ANOTHER BOUT OF CIRRUS ASSOCIATED WITH THE
SHORTWAVE ITSELF CROSSES THE AREA. THIS WILL YIELD A FAIRLY
COMPLICATED CLOUD COVER FORECAST FOR TODAY. HAVE TRIED TO DEPICT
SKY TRENDS WITH AS MUCH DETAIL AS POSSIBLE IN THE GRIDDED
FORECASTS...BUT ADJUSTMENTS--SOME POTENTIALLY LARGE--WILL BE
NEEDED AS THE DAY PROGRESSES.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
A WEAK COLD FRONT WILL APPROACH FROM THE NORTH TONIGHT AND IS
EXPECTED TO REMAIN OVER THE NORTHERN/CENTRAL MIDLANDS AND PEE DEE
THROUGH SUNRISE SUNDAY. WEAK RIDGING IN THE WAKE OF THE DEPARTING
SOUTHERN STREAM SHORTWAVE SHOULD HELP KEEP CONDITIONS DRY
OVERNIGHT WITH ANY SHOWER ACTIVITY LIKELY REMAINING WELL TO THE
WEST COINCIDENT WITH STRONGEST LOW-LEVEL JET.
THE PRIMARY CONCERN FOR TONIGHT IS FOR THE POTENTIAL FOR ANOTHER
BOUT OF DENSE FOG ADVECTING IN FROM THE GULF OF MEXICO AND
AFFECTING THE SOUTHERN ZONES DURING THE EARLY MORNING HOURS
SUNDAY. RAW VISIBILITY OUTPUT FROM THE NAM-12 KEEPS THE CORE OF
THE DENSE FOG WELL TO THE SOUTH ACROSS NORTHERN FLORIDA...HOWEVER
BOTH THE GFS AND NAM-BASED STATISTICAL GUIDANCE SHOW SEVERAL HOURS
OF DENSE FOG DEVELOPING ACROSS THE SOUTHERN ZONES. SUSPECT THE
STATISTICAL GUIDANCE MAY BE TRENDING IN THE RIGHT DIRECTION...
ESPECIALLY CONSIDERING HOW THE FOG IS EVOLVING THIS MORNING. PLAN
TO HIGHLIGHT PATCHY FOG ONCE AGAIN ACROSS THE FAR SOUTHERN ZONES
TO TREND AND INCLUDE A MENTION IN THE HAZARDOUS WEATHER OUTLOOK...
BUT LATER SHIFTS MAY NEED TO HIT THE COVERAGE HARDER WITH
SUBSEQUENT FORECAST PACKAGES. LOWS WILL RANGE FROM THE UPPER 40S
INLAND TO THE LOWER-MID 50S AT THE COAST.
SUNDAY AND MONDAY...THE FORECAST DETAILS FOR SUNDAY AND MONDAY
DEPEND HEAVILY ON THE LOCATION OF THE LINGERING COLD FRONT TO THE
NORTHWEST. NEARLY ZONAL FLOW ALOFT ON SUNDAY WILL ALLOW VARIOUS
IMPULSES TO EJECT EAST/NORTHEAST FROM THE STRONG CUT-OFF LOW OVER
TEXAS. THIS SERIES OF WEAK SHORTWAVES WILL PROVIDE ADDITIONAL
FORCING ALONG THE STALLED FRONT...AND WHEN COMBINED WITH
ASSOCIATED DEEP MOISTURE AND CONVERGENCE...WILL SUPPORT A SLIGHT
CHANCE FOR SHOWERS MAINLY ACROSS INLAND LOCATIONS ON SUNDAY.
THE MAJORITY OF SHORTWAVE ENERGY ARRIVES SUNDAY NIGHT AND
MONDAY...BEFORE TRANSIENT UPPER RIDGING BUILDS DOWNSTREAM OF THE
AFOREMENTIONED TEXAS LOW SYSTEM. ALTHOUGH MODEL SOLUTIONS DIFFER
IN SOME DETAILS...LATEST THINKING IS THAT THE ADDITIONAL ENERGY
WILL AID IN THE DEVELOPMENT OF A LOW PRESSURE WAVE ALONG THE
LINGERING FRONT. AS THE SURFACE WAVE TRACKS ALONG THE BOUNDARY
AND OFF THE COAST...PRECIPITATION CHANCES WILL INCREASE INTO THE
30 PERCENT RANGE FOR THE FAR NORTHWEST TIER COUNTIES CLOSEST TO
THE WAVERING FRONT. RIDGING WILL THEN QUICKLY DEVELOP MONDAY
NIGHT AND TUESDAY...WHILE THE WAVE OF LOW PRESSURE TRACKS OFFSHORE
AND THE BOUNDARY DISSIPATES. A BRIEF LULL IN PRECIPITATION
POTENTIAL COULD OCCUR LATE MONDAY NIGHT INTO EARLY TUESDAY.
TEMPERATURES ON SUNDAY AND MONDAY WILL CONTINUE TO RANGE WELL
ABOVE SEASONAL NORMALS. HIGH TEMPERATURES WILL REFLECT A SLIGHT
NORTHWEST/SOUTHEAST GRADIENT DUE TO THE LINGERING FRONT...WITH
HIGHS RANGING FROM THE UPPER 60S INLAND AND NORTH TO THE LOW 70S
NEAR THE ALTAMAHA RIVER IN SOUTHEAST GEORGIA.
TUESDAY...HIGH PRESSURE AT THE SURFACE AND ALOFT BRIEFLY BUILDS
OVER THE FORECAST AREA ON TUESDAY AHEAD OF THE POTENT LOW SYSTEM
TRACKING EAST ALONG THE GULF COAST STATES. CLOUDS WILL QUICKLY BE
INCREASING FROM WEST TO EAST...WHILE RAIN POTENTIAL ALSO INCREASES
AS THE DAY PROGRESSES. IT IS POSSIBLE THAT THE FIRST HALF OF THE
DAY WILL REMAIN DRY UNDER THE TRANSIENT RIDGING. SOUTH/SOUTHEAST
SURFACE FLOW AND RISING HEIGHTS ALOFT WILL CONTINUE TO SUPPORT
WARM TEMPERATURES IN THE UPPER 60S TO LOWER 70S TUESDAY
AFTERNOON...DESPITE THICKENING SKY COVER.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
CONDITIONS WILL DETERIORATE TUESDAY NIGHT INTO WEDNESDAY AS A
POTENT UPPER LOW AND ITS ASSOCIATED SURFACE SYSTEM QUICKLY SHIFT
FROM THE GULF COAST STATES TO THE TENNESSEE VALLEY. CONFIDENCE IN
TIMING AND COVERAGE OF PRECIPITATION CONTINUES TO INCREASE WITH
BETTER NUMERICAL MODEL AGREEMENT...AND HAVE BUMPED UP POPS
ACCORDINGLY. WILL ADVERTISE BEST RAIN POTENTIAL FOR WEDNESDAY
MORNING AND AFTERNOON...WHEN LATEST MODEL SOLUTIONS SUGGEST A COLD
FRONT WILL BE SWEEPING THROUGH THE FORECAST AREA.
DYNAMICS WITH THIS LOW SYSTEM CONTINUE TO LOOK QUITE IMPRESSIVE
LATE TUESDAY THROUGH WEDNESDAY...AS A 110 KT UPPER JET AND 40 KT
LOW LEVEL JET SHIFTS THROUGH THE SOUTHEAST STATES. THE MAIN
QUESTION REMAINS WHETHER LOW LEVEL INSTABILITY WILL BE SUFFICIENT
TO SUPPORT THUNDERSTORM DEVELOPMENT...AND CONSIDERABLE UNCERTAINTY
REMAINS AT THIS TIME. ALTHOUGH TEMPERATURES WILL CONTINUE TO BE
WARMER THAN NORMAL INTO MID WEEK...AND AN AFTERNOON FRONTAL
PASSAGE COULD BE MORE FAVORABLE...EXTENSIVE CLOUD COVER AND BETTER
RAIN COVERAGE COULD SUPPRESS INSTABILITY. IT SHOULD ALSO BE NOTED
THAT LOW LEVEL FLOW AHEAD OF THIS COMPLEX SYSTEM REMAINS GENERALLY
SOUTHEAST/SOUTH...WHICH MAY NOT BE AS FAVORABLE FOR SETTING UP
INSTABILITY. MODEL TRENDS WILL NEED TO BE CAREFULLY MONITORED
DURING THE NEXT FEW DAYS...HOWEVER PREFER TO STILL KEEP THUNDER
OUT OF THE FORECAST AT THIS TIME...LEANING MORE TOWARD A
WIDESPREAD RAIN AND POSSIBLE GUSTY WIND EVENT.
THE COLD FRONT WILL RAPIDLY MOVE OFF THE COAST LATE
WEDNESDAY...WHILE THE SURFACE LOW TRACKS INTO THE MID ATLANTIC
STATES. A SECONDARY DRY FRONT WILL MOVE THROUGH THE REGION
THURSDAY AFTERNOON...AS A BROAD UPPER TROUGH FOLLOWS IN THE WAKE
OF THE EARLIER SHORTWAVE. A DECENT COOLING TREND IS EXPECTED
THURSDAY INTO SATURDAY AS A RESULT...WITH TEMPERATURES FALLING
MORE TOWARD SEASONAL NORMALS. WILL MAINTAIN RAIN FREE CONDITIONS
THURSDAY INTO THE WEEKEND.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
VFR FOR THE NEXT 24 HOURS. CAREFULLY WATCHING AN EXPANDING FOG
BANK ACROSS NORTHEAST FLORIDA. CURRENT TRENDS AND SHORT TERM MODEL
DATA SUGGEST THE FOG WILL REMAIN SOUTH OF KSAV...BUT THIS WILL BE
CAREFULLY WATCHED.
EXTENDED AVIATION OUTLOOK...LATE NIGHT/EARLY MORNING FOG/STRATUS
POSSIBLE FOR MUCH OF NEXT WEEK. LOW PRESSURE AND ITS TRAILING COLD
FRONT WILL IMPACT THE TERMINALS NEXT WEDNESDAY WITH PERIODIC MVFR
OR LOWER CONDITIONS POSSIBLE. WIND SHEAR AND/OR GUSTY WINDS COULD
ALSO BECOME A CONCERN DURING THE MIDDLE OF NEXT WEEK.
&&
.MARINE...
QUIET MARINE CONDITIONS THROUGH TONIGHT WITH A GENERAL SOUTHWEST
FLOW DOMINATING. CAREFULLY WATCHING DENSE FOG APPROACHING FROM THE
SOUTHWEST WHICH MAY INFILTRATE THE GEORGIA NEARSHORE WATERS OVER
THE NEXT SEVERAL HOURS. MAY NEED A MARINE DENSE FOG ADVISORY
BEFORE SUNRISE. COULD SEE ANOTHER BOUT OF FOG MOVE INTO THE MARINE
AREAS EARLY SUNDAY MORNING.
FRIDAY THROUGH WEDNESDAY...CONDITIONS ACROSS THE COASTAL WATERS
WILL BE RELATIVELY QUIET INTO EARLY NEXT WEEK. LIGHT WINDS
GENERALLY 10 TO 15 KT WILL PREVAIL WITHIN A WEAK PRESSURE
GRADIENT. THERE WILL BE CONSIDERABLE VARIATIONS IN WIND
DIRECTION DUE TO AFTERNOON/EVENING SEA BREEZE CIRCULATIONS...THE
NOCTURNAL LAND BREEZE CIRCULATIONS...AND A WEAK COLD FRONT
DROPPING INTO THE AREA LATE SUNDAY INTO MONDAY.
INCREASING SOUTHERLY WINDS AND BUILDING SEAS ARE THEN ANTICIPATED
DURING THE MIDDLE OF NEXT WEEK IN ASSOCIATION WITH A MUCH STRONGER
FRONTAL SYSTEM. DEPENDENT UPON THE EVOLUTION OF LOW PRESSURE OVER
THE GULF COAST STATES AND APPALACHIANS...SMALL CRAFT ADVISORIES
ARE POSSIBLE WEDNESDAY INTO THURSDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1030 AM CST SAT JAN 7 2012
.DISCUSSION...
ISSUED 1030 AM CST SAT JAN 7 2012
RIDGING FROM HIGH PRESSURE OVER EASTERN NEBRASKA EXTENDS SOUTHEAST
TO SOUTHERN ILLINOIS...WITH A STEADY NORTHWEST FLOW CURRENTLY OVER
OUR AREA. LINGERING MID AND HIGH CLOUDS BEHIND THE EARLIER FRONTAL
PASSAGE HAS FINALLY CLEARED THE SOUTHEAST CWA. MAIN MORNING CONCERN
HAS BEEN WITH AN AREA OF STRATOCUMULUS THAT FORMED UPSTREAM ACROSS
MINNESOTA AND WISCONSIN OVERNIGHT. HOWEVER...LATEST VISIBLE
SATELLITE IMAGERY SHOWING SOME SUBSTANTIAL EROSION ON THE
SOUTHWEST FLANKS. SOME OF THE RESIDUAL CLOUDS CURRENTLY IN EAST
CENTRAL IOWA MAY REACH THE NORTHWEST CWA IN A COUPLE HOURS...BUT
THE BULK OF THE CLOUD SHIELD WILL MISS US TO THE NORTHEAST AS
INDICATED BY THE LATEST RUC RAPID REFRESH MODEL.
UPDATED ZONES/GRIDS WERE RECENTLY SENT TO ADJUST FOR THE LATEST
WIND AND TEMPERATURE TRENDS.
GEELHART
&&
.AVIATION...
ISSUED 1030 AM CST SAT JAN 7 2012
UPSTREAM STRATOCUMULUS DECK THAT WAS OF EARLIER CONCERN HAS BEEN
ERODING QUITE A BIT ON ITS SOUTHWEST FLANK. SOME SCATTERED CLOUD
REMNANTS AROUND 2000 FEET MAY AFFECT KPIA BRIEFLY EARLY THIS
AFTERNOON...BUT 900-850 MB LAYER HUMIDITY PLOT OFF THE RUC
MODEL...WHICH SEEMS TO SIMULATE THE CURRENT CLOUD ALIGNMENT THE
BEST...INDICATES THE REMAINING CEILINGS TO TRACK NORTHEAST OF THE
TAF SITES. OTHERWISE...HIGH PRESSURE WILL BUILD EASTWARD INTO
ILLINOIS OVERNIGHT...RESULTING IN THE CURRENT NORTHWEST WINDS
SWINGING TO THE NORTHEAST BY LATE NIGHT. VFR CEILINGS WELL ABOVE
10KFT EXPECTED TO FORM SUNDAY MORNING...AS SEPARATE NORTHERN AND
SOUTHERN JET STREAMS CONVERGE OVER THE MID MISSISSIPPI VALLEY.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 309 AM CST SAT JAN 7 2012
NOT A LOT OF SURPRISES IN THIS RUN FOR THE FORECAST. HIGH PRESSURE
BUILDING INTO THE MIDWEST FROM THE PLAINS...AND THE WEATHER IS
EXPECTED TO BE QUIET...IF NOT A LITTLE COOLER THAN YESTERDAY...
THROUGH THE REST OF THE WEEKEND. EVEN BEING COOLER...STILL WELL
ABOVE CLIMATE THROUGH THE FIRST PORTION OF THE WEEK. TUES
NIGHT/WED THE MODELS HAVE A BIT OF A DISAGREEMENT AS TO HOW TO
HANDLE THE SPLITTING FLOW...AND THE APPROACH OF THE NEXT SYSTEM
FOR PRECIP. OTHER THAN THAT...QUIET AND MILD FORECAST YET AGAIN.
SHORT TERM...TODAY AND TOMORROW...
MILD...SUNNY...AND WARMER THAN AVERAGE TEMPS...THOUGH DOWN A BIT
FROM YESTERDAYS BEHIND THE PASSING DRY COLD FRONT. WINDS
LIGHTENING UP A BIT IN THE OVERNIGHT WITH THE LOSS OF A SIG
PRESSURE GRADIENT...PARTICULARLY IN THE NORTH. SLIGHTLY COOLER
TOMORROW AS CLOUDS STREAM IN FROM THE MAIN SYSTEM WELL TO THE
SOUTHWEST. STILL QUIET AND ABOVE NORMAL TEMPS IN THE OVERNIGHT AS
WELL. ISSUES BEGIN TO BUILD TOMORROW NIGHT WITH THE FLOW OVER THE
DESERT SW BEGINNING TO SPLIT FROM THE NRN STREAM.
LONG TERM...MONDAY THROUGH FRIDAY...
ECMWF...NAM...AND GFS IN VERY GOOD AGREEMENT WITH THE 00Z RUN OF
THE ECMWF IN POSITION AND TRACK THROUGH FH84. LOW IN THE SW MOVES
UP THE OHIO RIVER VALLEY...CLIPPING THE FAR SW WITH RAIN CHANCES
TUES NIGHT/WED. ECMWF WAS PREVIOUSLY A BIT FURTHER NORTH THAN THIS
LAST RUN...NOW TRENDING WITH THE MORE SOUTHERLY GFS.
HOWEVER...ECMWF IS INTERACTING THIS LOW WITH THE NRN STREAM
LOW/LARGER SCALE TROF WED NIGHT/THURSDAY BRINGING A PROLONGED
CHANCE OF RAIN INTO THE LATTER HALF OF THE WEEK. WILL HAVE TO KEEP
AN EYE ON THAT. GFS IS A LITTLE LESS PROGRESSIVE...KEEPING THE
INTERACTION EAST OF THE REGION...A LITTLE SLOWER WITH THE PHASING
OF THAT WAVE. WHILE ANOTHER LOW PARKS OFF THE BAJA COAST AND GETS
READY TO CONTROL THE WEATHER INTO NEXT WEEKEND.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1126 AM CST SAT JAN 7 2012
.AVIATION...
VFR CONDITIONS TO CONTINUE FOR AT LEAST THE NEXT FEW DAYS. INCREASING
HIGH CLOUDS TO OVERSPREAD THE AREA LATE THIS AFTERNOON INTO SUNDAY
MORNING. PERIODS OF BKN-OVC CLOUD BASES AOA 15K AGL WILL BECOME MOSTLY
CLEAR TO CLEAR AGAIN BY LATE SUNDAY PM AS A WEAK UPPER AIR
DISTURBANCE PASSES WELL TO THE SOUTH. LIGHT NW WINDS OF 5 TO 10 MPH
WILL BECOME LIGHT AND VARIABLE FAVORING THE SE-S SUNDAY AM INTO
SUNDAY EVENING. ..NICHOLS..
&&
.PREV DISCUSSION... /ISSUED 329 AM CST SAT JAN 7 2012/
SYNOPSIS...
LOW PRESSURE THAT SWEPT THE COOL FRONT THROUGH THE REGION
YESTERDAY WAS OVER SE ONTARIO EARLY THIS MORNING. MSAS ANALYSIS
INDICATED A TROUGH EXTENDING WESTWARD FROM THE LOW ACROSS UPPER MI
INTO NORTHERN WI AND CENTRAL MN. SURFACE REPORTS AND SATELLITE FOG
CHANNEL IMAGERY INDICATED A LARGE AREA OF LOW CLOUDS ALONG AND
NORTH OF THIS AXIS OF CYCLONIC FLOW...AND JUST BEHIND THE UPPER
LEVEL TROUGH AXIS EVIDENT ON WATER VAPOR CHANNEL EXTENDING FROM
EASTERN UPPER MI TO NORTHERN IL. AT 08Z...THE RAGGED LEADING EDGE
OF THE LOW CLOUDS REACHED FROM THE N CENTRAL IA/MN BORDER TO NEAR
LA CROSSE...AND WAS EXPANDING SOUTHEAST TOWARD THE FORECAST AREA
AROUND 25 MPH. ACROSS THE FORECAST AREA OUT AHEAD OF THE CLOUD
DECK...UNDER MOSTLY CLEAR SKIES AND LIGHT W-NW WINDS...
TEMPERATURES WERE IN THE UPPER 20S TO MID 30S.
SHORT TERM...TODAY AND TONIGHT...
INITIAL FOCUS IS ON CLOUD TRENDS THIS MORNING. DISTANCE TIME TOOL
PLACES THE LEADING EDGE OF THESE CLOUDS INTO THE HIGHWAY 20 CORRIDOR
IN EASTERN IA AROUND 7 AM. THIS IS CLOSE TO THE LEADING EDGE OF THE
LATEST RUC DEPICTION OF HIGHER MOISTURE IN THE 900-950 LAYER
THAT IS SHOWN SPREADING SOUTH TO SOUTHEAST OVER THE ROUGHLY THE
NORTHEAST HALF OF THE FORECAST AREA BY MIDDAY. THE SOUTH TO
SOUTHWEST EXTENT MAY BE A BIT OVERDONE BASED ON THE WEAKENING LOW
LEVEL TROUGH AND LOW LEVEL FLOW BECOMING MORE ANTICYCLONIC TODAY
OVER ESPECIALLY THE WEST AS HIGH PRESSURE IN THE CENTRAL PLAINS
SPREADS EASTWARD. CONSIDERING THIS...AND WITH SUPPORT FROM THE
LATEST VSREF CIG PROBS...WILL HAVE SKIES BECOMING MOSTLY CLOUDY
EARLY THIS MORNING ACROSS NORTHERN PORTIONS OF EASTERN IA AND NW
IL...FOLLOWED BY CLEARING THIS AFTERNOON. OTHERWISE...WILL HAVE
HIGH CLOUDS MOVING OUT OF THE ROCKIES SPREADING INTO THE AREA FROM
LATE AFTERNOON AND OVERNIGHT.
WITH MORE CLOUDS IN THE NORTH...WILL KEEP HIGHS IN THE UPPER 30S...WHILE
THE SOUTH SHOULD PUSH THE HIGHER END OF GUIDANCE IN THE MID TO UPPER
40S. OVERNIGHT...SURFACE HIGH PRESSURE WILL BECOME CENTERED OVER THE
AREA BY SUNRISE. HIGH CLOUD COVER SHOULD CONTAIN TEMPERATURES
DESPITE THE COOL DRY AIRMASS AND LIGHT WINDS. PREVIOUS FORECAST
LOWS FROM THE MID 20S NORTH TO AROUND 30 LOOKED REASONABLE AND
MADE ONLY MINOR TWEAKS. ..SHEETS..
LONG TERM...SUNDAY THROUGH NEXT FRIDAY...
SUNDAY THROUGH TUESDAY WE REMAIN BETWEEN SYSTEMS AS THE SPLIT FLOW
REGIME WE HAVE BEEN SEEING A LOT OF LATELY AFFECTS THE CONUS. IN THE
SOUTHERN STREAM THERE IS A CUT OFF LOW THAT DEVELOPS ACROSS THE
SOUTHWEST CONUS...WITH A FASTER MOVING SHORTWAVE RIPPLING ACROSS THE
US/CANADIAN BORDER AND DIPPING INTO THE GREAT LAKES REGION. THE
UPPER LEVEL TROUGH ASSOCIATED WITH THE SOUTHERN STREAM CUT OFF LOW
PASSES ACROSS THE MIDWEST ON MONDAY. AHEAD OF THIS FEATURE WE HAVE
HAD SOME COLDER MID LEVEL TEMPERATURES...BUT ONCE IT PASSES WE
SHOULD GET WARM AIR ADVECTION AS RIDGING TO THE WEST ALLOWS WARMER
AIR TO SURGE INTO THE AREA AT THE MID LEVELS. THIS SHOULD ALSO
PRODUCE A MUCH WARMER DAY ON TUESDAY OVER SUNDAY AND MONDAY AS 850MB
TEMPERATURES RISE INTO THE POSITIVE 4-6 DEGREE RANGE AFTER HAVING
BEEN LINGERING AROUND NEGATIVE 4 FOR SUNDAY...ONLY SLOWLY WARMING TO
0 TO NEGATIVE 2 FOR MONDAY. THUS...HAVE A GRADUAL WARMING TREND IN
TEMPS FOR SUNDAY AND MONDAY...WITH A MORE SIGNIFICANT WARM UP FOR
TUESDAY.
WEDNESDAY THROUGH THURSDAY THINGS GET A BIT MORE INTERESTING...BUT
ALSO UNCERTAIN. AS THE SOUTHERN STREAM CUT OFF LOW SLOWLY WORKS OFF
TO THE EAST ALONG THE GULF COAST...THE MODELS BRING DOWN A FAIRLY
STRONG TROUGH OUT OF THE CANADIAN ROCKIES AND BRING IT DOWN ACROSS
THE MIDWEST ON WEDNESDAY...BRINGING MUCH COLDER AIR AND SOME
PRECIPITATION CHANCES. HOWEVER...THE MODELS HAVE SOME FAIRLY
SIGNIFICANT DISCREPANCIES IN TIMING AND STRENGTH AND IN RUN TO RUN
CONSISTENCY AT THIS TIME. THE LATEST 00Z ECMWF CAME IN WITH A MUCH
STRONGER SOLUTION THAN PREVIOUS OR OTHER MODELS...AND AM VIEWING
THIS RATHER PESSIMISTIC SOLUTION WITH SKEPTICISM. EITHER WAY...WE
ARE LOOKING A NOTICEABLE COOL DOWN FOR WEDNESDAY NIGHT THROUGH
THURSDAY BEHIND THIS COLD FRONT. MOISTURE MAY BE A LIMITING FACTOR
FOR ANY PRECIPITATION WITH THIS SYSTEM...AND HAVE KEPT POPS
NEGLIGIBLE AT THIS TIME...THOUGH ANTICIPATE THAT THEY MAY NEED TO BE
RAISED. FRIDAY THERE IS SOME RECOVERY IN THE TEMPERATURES BEHIND
THE WEDNESDAY-THURSDAY SYSTEM...BUT MUCH IS GOING TO DEPEND ON WHAT
THAT SYSTEM DOES BEFORE WE CAN HAVE MUCH CONFIDENCE IN THE FRIDAY
FORECAST. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
529 AM CST SAT JAN 7 2012
.AVIATION...
LOW CLOUDS OVER MUCH OF MN AND WESTERN WI WRAPPING AROUND A SYSTEM
OVER THE GREAT LAKES WILL CONTINUE TO DRIFT SOUTHEAST AND LIKELY
AFFECT DBQ AND CID THIS MORNING. AT THE CURRENT RATE...THE LEADING
EDGE OF THESE CLOUDS WITH BASES FROM 2000 TO 3000 FT...WILL REACH
CID AND DBQ BETWEEN 14Z AND 15Z. LATEST TAFS HAVE INTRODUCED TEMPO
GROUPS AT THESE TWO SITES FOR MVFR CIGS THIS MORNING. THE LOW
CLOUDS WILL LIKELY BECOME SCATTERED AND SHIFT EAST OF THE SITES
BY AFTERNOON AS HIGH PRESSURE BUILDS EAST FROM THE CENTRAL PLAINS.
OTHERWISE...VFR CONDITIONS WILL PERSIST THROUGH THE FORECAST
PERIOD WITH LIGHT WINDS AND MOSTLY HIGH LEVEL CLOUDS EXPECTED.
..SHEETS..
&&
.PREV DISCUSSION... /ISSUED 329 AM CST SAT JAN 7 2012/
SYNOPSIS...
LOW PRESSURE THAT SWEPT THE COOL FRONT THROUGH THE REGION
YESTERDAY WAS OVER SE ONTARIO EARLY THIS MORNING. MSAS ANALYSIS
INDICATED A TROUGH EXTENDING WESTWARD FROM THE LOW ACROSS UPPER MI
INTO NORTHERN WI AND CENTRAL MN. SURFACE REPORTS AND SATELLITE FOG
CHANNEL IMAGERY INDICATED A LARGE AREA OF LOW CLOUDS ALONG AND
NORTH OF THIS AXIS OF CYCLONIC FLOW...AND JUST BEHIND THE UPPER
LEVEL TROUGH AXIS EVIDENT ON WATER VAPOR CHANNEL EXTENDING FROM
EASTERN UPPER MI TO NORTHERN IL. AT 08Z...THE RAGGED LEADING EDGE
OF THE LOW CLOUDS REACHED FROM THE N CENTRAL IA/MN BORDER TO NEAR
LA CROSSE...AND WAS EXPANDING SOUTHEAST TOWARD THE FORECAST AREA
AROUND 25 MPH. ACROSS THE FORECAST AREA OUT AHEAD OF THE CLOUD
DECK...UNDER MOSTLY CLEAR SKIES AND LIGHT W-NW WINDS...
TEMPERATURES WERE IN THE UPPER 20S TO MID 30S.
SHORT TERM...TODAY AND TONIGHT...
INITIAL FOCUS IS ON CLOUD TRENDS THIS MORNING. DISTANCE TIME TOOL
PLACES THE LEADING EDGE OF THESE CLOUDS INTO THE HIGHWAY 20 CORRIDOR
IN EASTERN IA AROUND 7 AM. THIS IS CLOSE TO THE LEADING EDGE OF THE
LATEST RUC DEPICTION OF HIGHER MOISTURE IN THE 900-950 LAYER
THAT IS SHOWN SPREADING SOUTH TO SOUTHEAST OVER THE ROUGHLY THE
NORTHEAST HALF OF THE FORECAST AREA BY MIDDAY. THE SOUTH TO
SOUTHWEST EXTENT MAY BE A BIT OVERDONE BASED ON THE WEAKENING LOW
LEVEL TROUGH AND LOW LEVEL FLOW BECOMING MORE ANTICYCLONIC TODAY
OVER ESPECIALLY THE WEST AS HIGH PRESSURE IN THE CENTRAL PLAINS
SPREADS EASTWARD. CONSIDERING THIS...AND WITH SUPPORT FROM THE
LATEST VSREF CIG PROBS...WILL HAVE SKIES BECOMING MOSTLY CLOUDY
EARLY THIS MORNING ACROSS NORTHERN PORTIONS OF EASTERN IA AND NW
IL...FOLLOWED BY CLEARING THIS AFTERNOON. OTHERWISE...WILL HAVE
HIGH CLOUDS MOVING OUT OF THE ROCKIES SPREADING INTO THE AREA FROM
LATE AFTERNOON AND OVERNIGHT.
WITH MORE CLOUDS IN THE NORTH...WILL KEEP HIGHS IN THE UPPER 30S...WHILE
THE SOUTH SHOULD PUSH THE HIGHER END OF GUIDANCE IN THE MID TO UPPER
40S. OVERNIGHT...SURFACE HIGH PRESSURE WILL BECOME CENTERED OVER THE
AREA BY SUNRISE. HIGH CLOUD COVER SHOULD CONTAIN TEMPERATURES
DESPITE THE COOL DRY AIRMASS AND LIGHT WINDS. PREVIOUS FORECAST
LOWS FROM THE MID 20S NORTH TO AROUND 30 LOOKED REASONABLE AND
MADE ONLY MINOR TWEAKS. ..SHEETS..
LONG TERM...SUNDAY THROUGH NEXT FRIDAY...
SUNDAY THROUGH TUESDAY WE REMAIN BETWEEN SYSTEMS AS THE SPLIT FLOW
REGIME WE HAVE BEEN SEEING A LOT OF LATELY AFFECTS THE CONUS. IN THE
SOUTHERN STREAM THERE IS A CUT OFF LOW THAT DEVELOPS ACROSS THE
SOUTHWEST CONUS...WITH A FASTER MOVING SHORTWAVE RIPPLING ACROSS THE
US/CANADIAN BORDER AND DIPPING INTO THE GREAT LAKES REGION. THE
UPPER LEVEL TROUGH ASSOCIATED WITH THE SOUTHERN STREAM CUT OFF LOW
PASSES ACROSS THE MIDWEST ON MONDAY. AHEAD OF THIS FEATURE WE HAVE
HAD SOME COLDER MID LEVEL TEMPERATURES...BUT ONCE IT PASSES WE
SHOULD GET WARM AIR ADVECTION AS RIDGING TO THE WEST ALLOWS WARMER
AIR TO SURGE INTO THE AREA AT THE MID LEVELS. THIS SHOULD ALSO
PRODUCE A MUCH WARMER DAY ON TUESDAY OVER SUNDAY AND MONDAY AS 850MB
TEMPERATURES RISE INTO THE POSITIVE 4-6 DEGREE RANGE AFTER HAVING
BEEN LINGERING AROUND NEGATIVE 4 FOR SUNDAY...ONLY SLOWLY WARMING TO
0 TO NEGATIVE 2 FOR MONDAY. THUS...HAVE A GRADUAL WARMING TREND IN
TEMPS FOR SUNDAY AND MONDAY...WITH A MORE SIGNIFICANT WARM UP FOR
TUESDAY.
WEDNESDAY THROUGH THURSDAY THINGS GET A BIT MORE INTERESTING...BUT
ALSO UNCERTAIN. AS THE SOUTHERN STREAM CUT OFF LOW SLOWLY WORKS OFF
TO THE EAST ALONG THE GULF COAST...THE MODELS BRING DOWN A FAIRLY
STRONG TROUGH OUT OF THE CANADIAN ROCKIES AND BRING IT DOWN ACROSS
THE MIDWEST ON WEDNESDAY...BRINGING MUCH COLDER AIR AND SOME
PRECIPITATION CHANCES. HOWEVER...THE MODELS HAVE SOME FAIRLY
SIGNIFICANT DISCREPANCIES IN TIMING AND STRENGTH AND IN RUN TO RUN
CONSISTENCY AT THIS TIME. THE LATEST 00Z ECMWF CAME IN WITH A MUCH
STRONGER SOLUTION THAN PREVIOUS OR OTHER MODELS...AND AM VIEWING
THIS RATHER PESSIMISTIC SOLUTION WITH SKEPTICISM. EITHER WAY...WE
ARE LOOKING A NOTICEABLE COOL DOWN FOR WEDNESDAY NIGHT THROUGH
THURSDAY BEHIND THIS COLD FRONT. MOISTURE MAY BE A LIMITING FACTOR
FOR ANY PRECIPITATION WITH THIS SYSTEM...AND HAVE KEPT POPS
NEGLIGIBLE AT THIS TIME...THOUGH ANTICIPATE THAT THEY MAY NEED TO BE
RAISED. FRIDAY THERE IS SOME RECOVERY IN THE TEMPERATURES BEHIND
THE WEDNESDAY-THURSDAY SYSTEM...BUT MUCH IS GOING TO DEPEND ON WHAT
THAT SYSTEM DOES BEFORE WE CAN HAVE MUCH CONFIDENCE IN THE FRIDAY
FORECAST. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
329 AM CST SAT JAN 7 2012
.SYNOPSIS...
LOW PRESSURE THAT SWEPT THE COOL FRONT THROUGH THE REGION
YESTERDAY WAS OVER SE ONTARIO EARLY THIS MORNING. MSAS ANALYSIS
INDICATED A TROUGH EXTENDING WESTWARD FROM THE LOW ACROSS UPPER MI
INTO NORTHERN WI AND CENTRAL MN. SURFACE REPORTS AND SATELLITE FOG
CHANNEL IMAGERY INDICATED A LARGE AREA OF LOW CLOUDS ALONG AND
NORTH OF THIS AXIS OF CYCLONIC FLOW...AND JUST BEHIND THE UPPER
LEVEL TROUGH AXIS EVIDENT ON WATER VAPOR CHANNEL EXTENDING FROM
EASTERN UPPER MI TO NORTHERN IL. AT 08Z...THE RAGGED LEADING EDGE
OF THE LOW CLOUDS REACHED FROM THE N CENTRAL IA/MN BORDER TO NEAR
LA CROSSE...AND WAS EXPANDING SOUTHEAST TOWARD THE FORECAST AREA
AROUND 25 MPH. ACROSS THE FORECAST AREA OUT AHEAD OF THE CLOUD
DECK...UNDER MOSTLY CLEAR SKIES AND LIGHT W-NW WINDS...
TEMPERATURES WERE IN THE UPPER 20S TO MID 30S.
&&
.SHORT TERM...TODAY AND TONIGHT...
INITIAL FOCUS IS ON CLOUD TRENDS THIS MORNING. DISTANCE TIME TOOL
PLACES THE LEADING EDGE OF THESE CLOUDS INTO THE HIGHWAY 20 CORRIDOR
IN EASTERN IA AROUND 7 AM. THIS IS CLOSE TO THE LEADING EDGE OF THE
LATEST RUC DEPICTION OF HIGHER MOISTURE IN THE 900-950 LAYER
THAT IS SHOWN SPREADING SOUTH TO SOUTHEAST OVER THE ROUGHLY THE
NORTHEAST HALF OF THE FORECAST AREA BY MIDDAY. THE SOUTH TO
SOUTHWEST EXTENT MAY BE A BIT OVERDONE BASED ON THE WEAKENING LOW
LEVEL TROUGH AND LOW LEVEL FLOW BECOMING MORE ANTICYCLONIC TODAY
OVER ESPECIALLY THE WEST AS HIGH PRESSURE IN THE CENTRAL PLAINS
SPREADS EASTWARD. CONSIDERING THIS...AND WITH SUPPORT FROM THE
LATEST VSREF CIG PROBS...WILL HAVE SKIES BECOMING MOSTLY CLOUDY
EARLY THIS MORNING ACROSS NORTHERN PORTIONS OF EASTERN IA AND NW
IL...FOLLOWED BY CLEARING THIS AFTERNOON. OTHERWISE...WILL HAVE
HIGH CLOUDS MOVING OUT OF THE ROCKIES SPREADING INTO THE AREA FROM
LATE AFTERNOON AND OVERNIGHT.
WITH MORE CLOUDS IN THE NORTH...WILL KEEP HIGHS IN THE UPPER 30S...WHILE
THE SOUTH SHOULD PUSH THE HIGHER END OF GUIDANCE IN THE MID TO UPPER
40S. OVERNIGHT...SURFACE HIGH PRESSURE WILL BECOME CENTERED OVER THE
AREA BY SUNRISE. HIGH CLOUD COVER SHOULD CONTAIN TEMPERATURES
DESPITE THE COOL DRY AIRMASS AND LIGHT WINDS. PREVIOUS FORECAST
LOWS FROM THE MID 20S NORTH TO AROUND 30 LOOKED REASONABLE AND
MADE ONLY MINOR TWEAKS. ..SHEETS..
.LONG TERM...SUNDAY THROUGH NEXT FRIDAY...
SUNDAY THROUGH TUESDAY WE REMAIN BETWEEN SYSTEMS AS THE SPLIT FLOW
REGIME WE HAVE BEEN SEEING A LOT OF LATELY AFFECTS THE CONUS. IN THE
SOUTHERN STREAM THERE IS A CUT OFF LOW THAT DEVELOPS ACROSS THE
SOUTHWEST CONUS...WITH A FASTER MOVING SHORTWAVE RIPPLING ACROSS THE
US/CANADIAN BORDER AND DIPPING INTO THE GREAT LAKES REGION. THE
UPPER LEVEL TROUGH ASSOCIATED WITH THE SOUTHERN STREAM CUT OFF LOW
PASSES ACROSS THE MIDWEST ON MONDAY. AHEAD OF THIS FEATURE WE HAVE
HAD SOME COLDER MID LEVEL TEMPERATURES...BUT ONCE IT PASSES WE
SHOULD GET WARM AIR ADVECTION AS RIDGING TO THE WEST ALLOWS WARMER
AIR TO SURGE INTO THE AREA AT THE MID LEVELS. THIS SHOULD ALSO
PRODUCE A MUCH WARMER DAY ON TUESDAY OVER SUNDAY AND MONDAY AS 850MB
TEMPERATURES RISE INTO THE POSITIVE 4-6 DEGREE RANGE AFTER HAVING
BEEN LINGERING AROUND NEGATIVE 4 FOR SUNDAY...ONLY SLOWLY WARMING TO
0 TO NEGATIVE 2 FOR MONDAY. THUS...HAVE A GRADUAL WARMING TREND IN
TEMPS FOR SUNDAY AND MONDAY...WITH A MORE SIGNIFICANT WARM UP FOR
TUESDAY.
WEDNESDAY THROUGH THURSDAY THINGS GET A BIT MORE INTERESTING...BUT
ALSO UNCERTAIN. AS THE SOUTHERN STREAM CUT OFF LOW SLOWLY WORKS OFF
TO THE EAST ALONG THE GULF COAST...THE MODELS BRING DOWN A FAIRLY
STRONG TROUGH OUT OF THE CANADIAN ROCKIES AND BRING IT DOWN ACROSS
THE MIDWEST ON WEDNESDAY...BRINGING MUCH COLDER AIR AND SOME
PRECIPITATION CHANCES. HOWEVER...THE MODELS HAVE SOME FAIRLY
SIGNIFICANT DISCREPANCIES IN TIMING AND STRENGTH AND IN RUN TO RUN
CONSISTENCY AT THIS TIME. THE LATEST 00Z ECMWF CAME IN WITH A MUCH
STRONGER SOLUTION THAN PREVIOUS OR OTHER MODELS...AND AM VIEWING
THIS RATHER PESSIMISTIC SOLUTION WITH SKEPTICISM. EITHER WAY...WE
ARE LOOKING A NOTICEABLE COOL DOWN FOR WEDNESDAY NIGHT THROUGH
THURSDAY BEHIND THIS COLD FRONT. MOISTURE MAY BE A LIMITING FACTOR
FOR ANY PRECIPITATION WITH THIS SYSTEM...AND HAVE KEPT POPS
NEGLIGIBLE AT THIS TIME...THOUGH ANTICIPATE THAT THEY MAY NEED TO BE
RAISED. FRIDAY THERE IS SOME RECOVERY IN THE TEMPERATURES BEHIND
THE WEDNESDAY-THURSDAY SYSTEM...BUT MUCH IS GOING TO DEPEND ON WHAT
THAT SYSTEM DOES BEFORE WE CAN HAVE MUCH CONFIDENCE IN THE FRIDAY
FORECAST. ..LE..
&&
.AVIATION...
AREA OF LOW CLOUDS OVER MUCH OF MN AND WESTERN WI ASSOCIATED WITH A
SYSTEM MOVING OUT OF THE GREAT LAKES WILL CONTINUE TO SPREAD
SOUTHEAST THIS MORNING. AT THE CURRENT RATE...THE CLOUDS WITH BASES
AROUND 20 KFT TO 25 KFT WOULD REACH DBQ AROUND 15Z AND CID AFTER
16Z. CURRENT FORECASTS HAVE ONLY SCATTERED CLOUDS AT THIS TIME...AND
WILL CONTINUE TO MONITOR TRENDS FOR POSSIBLE UPGRADE TO MVFR CIGS AT
DBQ AND CID FOR LATE MORNING INTO EARLY AFTERNOON. ANY LOW CLOUDS
THAT DO REACH THE AREA WOULD LIKELY DISSIPATE MID TO LATE
AFTERNOON AS HIGH PRESSURE OVER THE CENTRAL PLAINS SPREADS
EASTWARD. OTHERWISE...VFR CONDITIONS WILL PERSIST THROUGH THE
FORECAST PERIOD WITH ONLY HIGH LEVEL CLOUDS EXPECTED. ..SHEETS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SHEETS/LE
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1135 PM CST FRI JAN 6 2012
.UPDATE...
UPDATED FOR THE 06Z TAF ISSUANCE.
&&
.PREV DISCUSSION... /ISSUED 919 PM CST FRI JAN 6 2012/
UPDATE...
INTERIM FORECAST UPDATE TO ADDRESS NEAR TERM CLOUD
COVER...TEMPERATURE AND PRECIPITATION ISSUES OVER SOUTHERN
PENNYRILE.
NEAR TERM...
MAIN ADJUSTMENT FOR THIS EVENING WAS TO ADJUST THE SPATIAL
COVERAGE OF THE OPAQUE CLOUD COVER AND SLOWED THE TIMING OF
NORTHWARD TRANSPORT OF THIS CLOUD COVER DURING THE EVENING HOURS.
SIMILAR ADJUSTMENTS WERE MADE TO SLOW THE FRONTAL PASSAGE SLIGHTLY
/1-2 HOURS/ AND INCREASE DEWPOINTS /1-2 DEGREES/ A LITTLE FASTER
/1-2 HOURS/. FINALLY...MADE SOME TEMPORAL ADJUSTMENTS TO THE
INFLUX OF HIGHER POPS INTO THE EXTREME SOUTHER PENNYRILE OVERNIGHT.
THE 12KM NAM-WRF/5KM DOWNGRADE VERSION OF THE NAM-WRF/13KM RUC AND
SREF GUIDANCE APPEARED TO HAVE THE BEST HANDLE ON THE
MOISTURE/WIND/MASS FIELDS FOR THE REMAINDER OF THIS PERIOD...SO
THIS GUIDANCE WAS INCORPORATED INTO THE FIRST PERIOD FORECAST UPDATE.
PREV DISCUSSION...
DISCUSSION... /ISSUED 240 PM CST FRI JAN 6 2012/
ANOTHER QUIET DAY TODAY WITH TEMPERATURES WELL ABOVE NORMAL. MOST
IF NOT ALL STATIONS REPORTED AT LEAST 60 DEGREES OR ABOVE. A
FRONTAL BOUNDARY...NOW STRETCHING ACROSS LAKE MICHIGAN DOWN INTO
THE TEXAS PANHANDLE...WILL CONTINUE HEADING OUR WAY. MOISTURE IS
ALREADY SURGING NORTHWARD AS EVIDENT ON SATELLITE/OBSERVATIONS. WE
SHOULD CONTINUE TO SEE THIS MOISTURE MOVE NORTHWARD THE REST OF
TODAY AND INTO THIS EVENING/OVERNIGHT...LEADING TO AN INCREASE IN
CLOUDS FROM SOUTH TO NORTH. THE FRONT STARTS MOVING INTO THE AREA
AND STARTS TO SCOUR US OUT LATER THIS EVENING. THE MOISTURE IS
RATHER SHALLOW...BUT DOES BECOME DEEPER OVER WEST KENTUCKY THIS
EVENING AND OVERNIGHT. CANNOT RULE OUT SOME SHOWER ACTIVITY AHEAD
OF THE FRONT DUE TO THIS DEEPER MOISTURE...BUT COVERAGE SHOULD BE
LIMITED. BEST CHANCES WILL BE FROM MURRAY TO MADISONVILLE AND
SOUTHWARD...ESPECIALLY NEAR THE TENNESSEE BORDER.
HIGH PRESSURE BUILDS INTO THE REGION FOR THE WEEKEND. WHILE WE
WILL SEE A SLIGHT COOL DOWN...MOST OF THE COLD AIR WILL BE
SITUATED ACROSS THE MIDWESTERN STATES. THEREFORE...WE WILL STAY
ABOVE NORMAL FOR THE WEEKEND AS FAR AS TEMPERATURES.
MEANWHILE...OVER THE WEEKEND...ANOTHER SYSTEM WILL BE DIVING
SOUTHEAST ACROSS THE INTERMOUNTAIN WEST AND EVENTUALLY MOVE INTO
THE FOUR CORNERS REGION BY SUNDAY MORNING. MODELS AGREE IN CUTTING
OFF THE UPPER LOW OVER NM/WEST TX...WHICH SHOULD ACT TO KEEP ANY
POSSIBLE ACTIVITY TO OUR SOUTH WHERE THE MAIN SFC LOW WILL FORM.
12Z MODELS ARE IN AGREEMENT IN KEEPING THE AREA DRY MONDAY THROUGH
AT LEAST TUESDAY MORNING...AS SURFACE HIGH PRESSURE DOMINATES THE
REGION. DESPITE THE PRESENCE OF THE HIGH...TEMPERATURES WILL STILL
BE ABOUT 5 DEGREES ABOVE NORMAL ON MONDAY.
LOOKING TO OUR MID WEEK MESS...THE MODELS CONTINUE TO AGREE IN
PRINCIPLE...BUT DISAGREE ON THE DETAILS OF SENSIBLE WEATHER IN OUR
AREA. THE 12Z ECMWF HAS CONTINUED TO TREND SLOWER AND SOUTH WITH THE
CLOSED LOW COMING OUT OF THE SOUTHWEST...EFFECTIVELY KEEPING THE
ENTIRE AREA DRY TUESDAY AND TUESDAY NIGHT. ALL OTHER GUIDANCE IS
POINTING TO A MOSTLY DRY TUESDAY...WITH WIDESPREAD RAIN/SHOWERS
SPREADING ACROSS THE ENTIRE AREA TUESDAY NIGHT. TEMPERED POPS A BIT
ON OUR NORTHERN AND WESTERN BORDER AREAS TUESDAY NIGHT...BUT LEFT
THE OLD CONSENSUS MOSTLY IN PLAY.
ANOTHER TREND FROM 24 HOURS AGO IS NOTED IN THE GFS WHICH IS FARTHER
EAST WITH ITS NORTHERN STREAM SYSTEM...AND THE ASSOCIATED CANADIAN
SURFACE HIGH. IT ACTUALLY BRINGS THE COLD AIR INTO SOUTHERN ILLINOIS
BEFORE THE DEFORMATION ZONE RAIN EXITS THE AREA. BASED SOLELY ON THE
GFS SOLUTION...WOULD NOT BE SURPRISED TO SEE A BRIEF CHANGE OVER TO
SNOW BEFORE THE PRECIPITATION ENDS WEDNESDAY AFTERNOON. OF COURSE
THE 12Z ECMWF KEEPS SOUTHERN ILLINOIS COMPLETELY DRY THROUGH THIS
PERIOD. KEPT THE PREVIOUS CONSENSUS CHANCY POPS FOR WEDNESDAY...AND
WENT WITH A WARMER SOLUTION THAN THE GFS...KEEPING THE PRECIPITATION
ALL RAIN WEDNESDAY.
THE ECMWF AND GFS EACH PIVOT THE MAIN MID/UPPER LEVEL TROUGH THROUGH
THE AREA WEDNESDAY NIGHT INTO THURSDAY...BUT ARE DRY COMPARED TO
YESTERDAY. HAVE SLIGHT POPS WEDNESDAY NIGHT AND KEPT IT DRY FOR
THURSDAY. WOULD EXPECT ANY PRECIPITATION WEDNESDAY NIGHT OR THURSDAY
TO QUICKLY BECOME SNOW WITH COOL AIR AT THE LOW-LEVELS AND ALOFT.
SURFACE HIGH PRESSURE QUICKLY SETTLES SOUTH OF THE AREA BY 00Z
SATURDAY...BUT SHOULD SEE A RATHER CHILLY END TO THE WEEK...WITH OR
WITHOUT ANY SNOW COVER.
THE MODELS HAVE NOT DETERMINED MUCH FOR OUR MID-WEEK STORM SYSTEM AS
OF YET...HOPEFULLY THEY WILL HASH IT OUR OVER THE WEEKEND. STAY
TUNED.
&&
.AVIATION...
SW WINDS AOB 10 KTS WILL VEER AROUND TO THE NORTHWEST FROM 08-10Z
WITH A FRONTAL PASSAGE...THEN VEER AROUND TO THE NORTH NORTHEAST
AFT 15Z. LOW LEVEL MOISTURE WILL BE ON THE INCREASE AHEAD OF THE
FRONT...BUT ANY MEASURABLE PRECIPITATION SHOULD DEVELOP SOUTH AND
EAST OF ALL TAF SITES. KPAH COULD SEE AN MVFR CEILING FROM 07-09Z BUT
CIGS SHOULD REMAIN VFR AT THE OTHER SITES UNTIL FRONTAL PASSAGE.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
MO...NONE.
IL...NONE.
IN...NONE.
&&
$$
JP/SMITH/99
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1006 PM EST SUN JAN 8 2012
.SYNOPSIS...
HIGH PRESSURE, WILL PROVIDE DRY, MILD CONDITIONS THROUGH TUESDAY.
LOW PRESSURE, COMING NORTHEAST FROM LOUISIANA, WILL PROVIDE RAIN
WEDNESDAY, FOLLOWED BY COLDER CONDITIONS WITH SNOW SHOWERS BY
THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH MONDAY/...
RECENT SATELLITE DATA, COUPLED WITH HRRR AND NAM MODEL OUTPUT, SHOW
HIGH CLOUDS PASSING ACROSS THE UPPER OHIO VALLEY LATE TONIGHT AND
MONDAY MORNING. CLOUDS CAN DECREASE ENOUGH MONDAY AFTERNOON TO
ALLOW FOR SOME SUNSHINE.
FORECASTED TEMPERATURES TO CONTINUE WARMER THAN NORMAL PER RECENT
HRRR MODEL OUTPUT AND GFS AND NAM MOS. LOWS TONIGHT WILL BE ABOUT
5 DEGREES WARMER THAN NORMAL. HIGHS MONDAY WILL BE CLOSE TO 10
DEGREES WARMER THAN NORMAL.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
RECENT SREF MODEL OUTPUT SHOWS DRY, MILD CONDITIONS CONTINUING
INTO TUESDAY NIGHT. THERE CAN BE LESS CLOUDS TUESDAY THAN MONDAY.
THEN LOW PRESSURE, COMING NORTHEAST FROM LOUISIANA, WILL SPREAD
RAIN INTO THE UPPER OHIO VALLEY WEDNESDAY. ONSET TIMING WAS DETERMINED
USING SREF MODEL OUTPUT ADJUSTED BY PREFERRED GFS MODEL OUTPUT.
FORECASTED TEMPERATURES, USING BLEND OF GFS AND NAM MOS. THESE
SHOWED TEMPERATURES TUESDAY CAN BE SIMILAR TO MONDAY, DESPITE MORE
SUNSHINE TUESDAY. WEDNESDAY`S DAYTIME TEMPERATURES SHOULD BE
WARMER, BUT THAT WILL DEPEND ON RAINFALL ONSET.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
PER RECENT NAEFS AND ECMWF MODEL OUTPUT, RAIN WILL BE LIKELY
ACROSS THE REGION WEDNESDAY NIGHT, AS STRONG SURFACE LOW MOVES
ACROSS THE MID ATLANTIC STATES AND TO THE COAST BY THURSDAY
MORNING.
ON THURSDAY, QUITE STRONG NORTHERN BRANCH CLOSED UPPER LOW DIGS
ACROSS THE GREAT LAKES. THIS NORTHERN BRANCH LOW WILL BRING MUCH
COLDER AIR INTO REGION STARTING THURSDAY AFTERNOON AND CONTINUING
INTO THE WEEKEND. RAIN SHOWERS WILL CHANGE TO SNOW SHOWERS BY
THURSDAY NIGHT, FOLLOWED BY NORTHWEST FLOW SNOW SHOWERS INTO SATURDAY.
HIGH PRESSURE WILL BRING DRY AIR TO DIMINISH SNOW SHOWERS SUNDAY.
AFTER A MILD START WEDNESDAY NIGHT INTO EARLY THURSDAY, HPC
GUIDANCE, USING BLEND OF ECMWF AND NAEFS MODEL OUTPUT, SHOW POST
SYSTEM COOL DOWN CAUSING TEMPERATURES TO DROP TO ABOUT 10 DEGREES
COLDER THAN NORMAL FOR THE WEEKEND.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
EXPECT VFR THROUGH DAYTIME MONDAY AS A WEAK DISTURBANCE PASSING
SOUTH OF THE REGION WILL PROVIDE NO MORE THAN HIGH CLOUDINESS.
WINDS WILL BE LIGHT, BECOMING SOUTHWEST MONDAY.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
VFR INTO EARLY WEDNESDAY. NORTHEASTBOUND LOW PRESSURE FROM LOUISIANA
WILL PROVIDE RESTRICTIONS IN RAIN LATER WEDNESDAY INTO EARLY
THURSDAY. RAIN SHOWERS WILL MIX AND CHANGE TO SNOW SHOWERS THURSDAY
WITH RESTRICTIONS IN SNOW SHOWERS THROUGH FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
818 PM EST SUN JAN 8 2012
.SYNOPSIS...
HIGH PRESSURE, WILL PROVIDE DRY, MILD CONDITIONS THROUGH TUESDAY.
LOW PRESSURE, COMING NORTHEAST FROM LOUISIANA, WILL PROVIDE RAIN
WEDNESDAY FOLLOWED BY COLDER CONDITIONS WITH SNOW SHOWERS BY
FRIDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
RECENT SATELLITE DATA COUPLED WITH HRRR AND NAM MODEL OUTPUT SHOW
HIGH CLOUDS PASSING ACROSS THE UPPER OHIO VALLEY LATE TONIGHT AND
MONDAY MORNING. CLOUDS CAN DECREASE ENOUGH MONDAY AFTERNOON TO
ALLOW FOR SOME SUNSHINE.
FORECASTED TEMPERATURES TO CONTINUE WARMER THAN NORMAL PER RECENT
HRRR MODEL OUTPUT AND GFS AND NAM MOS. LOWS TONIGHT WILL BE ABOUT
5 DEGREES WARMER THAN NORMAL. HIGHS MONDAY WILL BE CLOSE TO 10
DEGREES WARMER THAN NORMAL.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
RECENT SREF MODEL OUTPUT SHOWS DRY, MILD CONDITIONS CONTINUING
INTO TUESDAY NIGHT. LOW PRESSURE, COMING NORTHEAST FROM LOUISIANA,
WILL SPREAD RAIN INTO THE UPPER OHIO VALLEY WEDNESDAY. ONSET
TIMING DETERMINED USING SREF MODEL OUTPUT ADJUSTED BY PREFERRED
GFS MODEL OUTPUT.
FORECASTED TEMPERATURES, USING BLEND OF GFS AND NAM MOS, FOR
TUESDAY TO BE SIMILAR TO MONDAY. WEDNESDAY`S DAYTIME TEMPERATURES
CAN BE WARMER DEPENDING ON TIMING OF RAINFALL ONSET.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
RAIN WILL BE LIKELY ACROSS THE REGION WEDNESDAY NIGHT AS STRONG
SURFACE LOW MOVES ACROSS THE MID ATLANTIC STATES AND TO THE COAST BY
THURSDAY MORNING.
ON THURSDAY, QUITE STRONG NORTHERN BRANCH CLOSED UPPER LOW DIGS
ACROSS THE GREAT LAKES. THIS NORTHERN BRANCH LOW WILL BRING MUCH
COLDER AIR INTO REGION STARTING THURSDAY AFTERNOON AND CONTINUING
INTO THE WEEKEND. RAIN SHOWERS WILL MIX WITH AND CHANGE TO SNOW
THURSDAY, FOLLOWED BY NORTHWEST FLOW SNOW SHOWERS INTO SATURDAY.
A RIDGE OF HIGH PRESSURE WILL BRING DRY AIR AND DIMINISH
SNOW SHOWERS SUNDAY.
AFTER A MILD START WEDNESDAY NIGHT INTO EARLY THURSDAY, HPC
GUIDANCE, USING BLEND OF ECMWF AND GFS MODEL OUTPUT, SHOW POST
SYSTEM COOL DOWN CAUSING TEMPERATURES TO DROP TO ABOUT 10 DEGREES
COLDER THAN NORMAL FOR THE WEEKEND.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
BEYOND SOME MID-HIGH CLOUDS, ASSOCIATED WITH A VERY WEAK DISTURBANCE
PASSING SOUTH OF THE REGION, HIGH PRESSURE WILL MAINTAIN VFR
CONDITIONS THROUGH MONDAY. WINDS WILL BE LIGHT OUT OF THE NORTH
THIS EVENING, BACKING TOWARDS TO SOUTHWEST ON MONDAY.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
VFR INTO EARLY WEDNESDAY. NORTHEASTBOUND LOW PRESSURE FROM LOUISIANA
WILL PROVIDE RESTRICTIONS IN RAIN LATER WEDNESDAY INTO EARLY
THURSDAY. RAIN SHOWERS WILL MIX AND CHANGE TO SNOW SHOWERS THURSDAY
WITH RESTRICTIONS IN SNOW SHOWERS THROUGH FRIDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
308 PM EST SAT JAN 7 2012
.SYNOPSIS...
A NORTHWESTERLY FLOW IN THE WAKE OF A FRONT WILL ALLOW FOR
INCREASED CLOUD COVERAGE NORTHEAST OF PITTSBURGH TONIGHT AND
EARLY SUNDAY. HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST,
ALLOWING FOR QUIET WEATHER AND ABOVE NORMAL TEMPERATURES INTO
TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO VALLEY
IN A ZONAL FLOW. AT THE SURFACE, A 1003MB SURFACE LOW IS CENTERED
ACROSS QUEBEC WITH A 1024MB HIGH IS CENTERED ACROSS THE CENTRAL
PLAINS. A MOISTURE STARVED COLD FRONT EXTENDS FROM THE SURFACE LOW
INTO THE UPPER OHIO VALLEY AND HAS PUSHED EAST OF THE RIDGES.
THERE IS WEAK COLD AIR ADVECTION BEHIND THE FRONT, WITH LITTLE
TO SHOW WITH ITS PASSAGE ASIDE FROM A WIND SHIFT TO WEST-
NORTHWESTERLY.
TONIGHT...THE NAM/HRRR ARE INDICATING THAT WEAK COLD AIR ADVECTION
ALONG WITH THE 850MB FLOW SHIFT TO NORTHWESTERLY WILL BE ENOUGH
FOR A SCHC OF SNOW SHOWERS NORTH OF THE I-80 CORRIDOR. OTHERWISE,
THE SURFACE HIGH WILL BEGIN TO BUILD IN FROM THE WEST TONIGHT WITH
A DRY FORECAST IN PLACE. ONGOING WEAK COLD AIR ADVECTION WILL
ALLOW FOR NOTICEABLY COLDER LOWS TONIGHT, RANGING FROM THE MID TO
UPPER 20S ACROSS THE AREA.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
THERE IS NAM/GFS/ECMWF AGREEMENT THAT HIGH PRESSURE WILL SLOWLY MOVE
FROM THE MISSOURI VALLEY INTO THE UPPER OHIO VALLEY THROUGH THIS
PERIOD. THIS WILL ALLOW FOR DRY WEATHER THROUGH WITH A RELATIVELY
BENIGN AND WARM SPELL FOR JANUARY.
A NORTHWESTERLY LOW-LEVEL FLOW WILL ALLOW FOR PARTLY TO MOSTLY
CLOUDY SKIES PRIMARILY NORTH AND EAST OF PITTSBURGH EARLY ON
SUNDAY. CLOUD COVERAGE WILL DECREASE LATE IN THE DAY AS THE LOW-
LEVEL FLOW BECOMES ZONAL. AFTERWARD, A FAIR AMOUNT OF SUNSHINE CAN
BE EXPECTED FOR MONDAY AND TUESDAY. HIGHS ON SUNDAY ARE A MAV/MET
BLEND, RANGING FROM THE UPPER 30S ACROSS THE I-80 CORRIDOR AND
EASTERN RIDGES TO THE LOWER 40S ELSEWHERE. WEAK WARM AIR ADVECTION
WILL ALLOW TEMPS TO BE PROGRESSIVELY WARMER MONDAY AND TUESDAY
WITH HIGHS FORECAST TO BE AROUND 10 DEGREES ABOVE NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A CLOSED MID-LEVEL LOW WILL MOVE FROM THE WESTERN GULF STATES ACROSS
THE TENNESSEE VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE CHANCE OF
RAIN WILL ARRIVE LATE TUESDAY NIGHT AS A WARM FRONT AHEAD OF THE LOW
PUSHES NORTHWARD INTO THE AREA. MODEL THICKNESSES WILL WARM ABOVE
CRITICAL THRESHOLDS THAT WOULD BE NEEDED FOR A WINTRY MIX, SO
FORECAST IS FOR ALL RAIN TO BEGIN THE EVENT. TEMPERATURES WILL BE
AROUND 10 DEGREES ABOVE NORMAL THROUGH THE MID-WEEK.
RAIN WILL BE LIKELY ACROSS THE REGION WEDNESDAY INTO WEDNESDAY NIGHT
AS THE LOW MOVES ACROSS WEST VIRGINIA AND INTO THE NORTHEAST. BY
THURSDAY MORNING LOW WILL BE EXITING EAST AS QUITE STRONG NORTHERN
BRANCH CLOSED UPPER LOW DIGS ACROSS THE GREAT LAKES. THIS NORTHERN
BRANCH LOW WILL BRING MUCH COLDER AIR INTO REGION STARTING THURSDAY
AND CONTINUING INTO THE START OF THE WEEKEND. RAIN SHOWERS WILL MIX
WITH AND CHANGE TO SNOW THURSDAY FOLLOWED BY NORTHWEST FLOW SNOW
SHOWERS INTO FRIDAY. BY SATURDAY A RIDGE OF HIGH PRESSURE WILL BRING
DRY AND COLD CONDITIONS. TEMPERATURES WILL FALL TO 5 TO 10
DEGREES BELOW NORMAL LATE WEEK.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
GENERAL VFR CONDITIONS OVERNIGHT INTO SUNDAY AS A COLD FRONT WILL BE
WELL EAST OF THE RIDGES. AS A BIT COOLER AIR AT 850MB WORKS ACROSS
LAKES SUNDAY MORNING MVFR CIGS LOOK TO DEVELOP ACROSS NORTHERN
TERMINALS WITH VFR CIGS ELSEWHERE. GUSTY WEST TO NORTHWEST WINDS
WILL DIMINISH THIS EVENING.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
HIGH PRESSURE WILL GIVE GENERAL VFR CONDITIONS INTO TUESDAY NIGHT.
LOW PRESSURE WILL APPROACH LATER TUESDAY NIGHT WITH RESTRICTIONS
WEDNESDAY AND THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
117 PM EST SAT JAN 7 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL PUSH EAST OF THE AREA THIS EVENING AND
BRING SLIGHTLY COOLER TEMPERATURES. QUIET WEATHER AND ABOVE NORMAL
TEMPERATURES WILL CONTINUE THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO REMOVE
POPS ACROSS THE RIDGE COUNTIES.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB SHORT WAVE
TROUGH SWINGING ACROSS ONTARIO WITH THE UPPER OHIO VALLEY IN A
ZONAL FLOW SOUTH OF THIS FEATURE. AT THE SURFACE, A 1004MB SURFACE
LOW IS CENTERED ACROSS QUEBEC WITH A 1025MB HIGH IS CENTERED
ACROSS THE CENTRAL PLAINS. A MOISTURE STARVED COLD FRONT EXTENDS FROM
THE SURFACE LOW INTO THE UPPER OHIO VALLEY AND HAS PUSHED EAST OF
A LINE FROM DUBOIS TO PITTSBURGH TO NEW MARTINSVILLE. THERE IS WEAK
COLD AIR ADVECTION BEHIND THE FRONT, WITH LITTLE TO SHOW WITH ITS
PASSAGE ASIDE FROM A WIND SHIFT TO WESTERLY AND SOME MID- DECK
CLOUDS BEHIND IT.
THIS AFTERNOON...THE WEAK FRONT WILL PUSH EAST OF THE AREA. THE
FRONTAL PASSAGE WILL BE DRY. HIGH TEMPS ARE CLOSEST TO A HRRR/LAMP
BLEND, RANGING FROM THE MID 50S ACROSS THE LOWLANDS SOUTH AND EAST
OF PITTSBURGH TO THE MID 40S ACROSS THE I-80 CORRIDOR.
TONIGHT...THE NAM/HRRR ARE INDICATING THAT WEAK COLD AIR ADVECTION
ALONG WITH THE 850MB FLOW SHIFT TO NORTHWESTERLY WILL BE ENOUGH
FOR A SCHC OF SNOW SHOWERS NORTH OF THE I-80 CORRIDOR. OTHERWISE,
THE SURFACE HIGH WILL BEGIN TO BUILD IN FROM THE WEST TONIGHT WITH
A DRY FORECAST IN PLACE. ONGOING WEAK COLD AIR ADVECTION WILL
ALLOW FOR NOTICEABLY COLDER LOWS TONIGHT, RANGING FROM THE MID TO
UPPER 20S ACROSS THE AREA.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
WEAK SURFACE RIDGE WILL BE ACROSS REGION SUNDAY THROUGH
MONDAY IN A SPLIT FLOW IN THE JET STREAM ACROSS THE U.S. A WEAK
SHORTWAVE WILL SLIDE ACROSS THE EASTERN LAKES SUNDAY INTO SUNDAY
NIGHT WITH AN INCREASE IN CLOUDS BUT NO PRECIPITATION IS EXPECTED.
TEMPERATURES WILL AVERAGE NEAR TO ABOVE SEASONAL NORMS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THERE IS GFS/ECMWF AGREEMENT THAT HIGH PRESSURE WILL CROSS THE UPPER
OHIO VALLEY AND KEEP THE FORECAST DRY MONDAY NIGHT THROUGH TUESDAY.
A CLOSED MID-LEVEL LOW WILL THEN MOVE FROM THE WESTERN GULF STATES
ACROSS THE THE TENNESSEE VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE
CHANCE OF SHOWERS WILL BEGIN TUESDAY NIGHT AS A WARM FRONT AHEAD OF
THE LOW PUSHES NORTHWARD INTO THE AREA. MODEL THICKNESSES WILL WARM
ABOVE CRITICAL THRESHOLDS THAT WOULD BE NEEDED FOR A WINTRY MIX, SO
FORECAST IS FOR ALL RAIN TO BEGIN THE EVENT. TEMPERATURES WILL BE
AROUND 10 DEGREES ABOVE NORMAL THROUGH THE MID-WEEK.
RAIN WILL BE LIKELY FOR AREAS SOUTH AND EAST OF PITTSBURGH WEDNESDAY
INTO WEDNESDAY NIGHT AS THE LOW MOVES ACROSS WEST VIRGINIA AND INTO
THE NORTHEAST. 12Z GFS/00Z ECMWF ARE OFF IN TIMING OF THE COLD AIR
ADVECTION ON THE BACK SIDE OF THIS SYSTEM AND FORECAST SIDES WITH
THE FASTER GFS, TURNING PRECIP OVER TO SNOW SHOWERS ACROSS THE AREA BY
THURSDAY MORNING. CHANCE POPS ARE FORECAST FOR THE RIDGES AND LAKE
EFFECT COUNTIES AS COLD AIR ADVECTION WITH A NORTHWESTERLY FLOW
ALLOWS FOR SOME LINGERING SNOW SHOWERS THURSDAY AND FRIDAY. THE
ARCTIC AIR MASS IN THE WAKE OF THIS SYSTEM WILL BRING TEMPS CLOSER
TO NORMAL VALUES ON THURSDAY, DROPPING TO 5 DEGREES BELOW NORMAL BY
FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
GENERAL VFR CONDITIONS TODAY. A WEAK FRONT HAS PUSHED EAST OF
KPIT/KMGW AND WINDS WILL SHIFT FROM WESTERLY TO NORTHWESTERLY FOR
THE TERMINALS WITH THE PASSAGE OF THE FRONT.
OUTLOOK...SATURDAY NIGHT THROUGH THURSDAY...
HIGH PRESSURE WILL BUILD IN ON SATURDAY NIGHT WITH GENERAL VFR
CONDITIONS ANTICIPATED UNTIL THE APPROACH OF LOW PRESSURE DURING
THE MID WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1045 AM EST SAT JAN 7 2012
.SYNOPSIS...
A WEAK GREAT LAKES COLD FRONT WILL CROSS THIS AREA TODAY AND BRING
SLIGHTLY COOLER TEMPERATURES. QUIET WEATHER AND ABOVE NORMAL
TEMPERATURES WILL CONTINUE THROUGH TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED THIS
MORNING TO ACCOUNT FOR THE LATEST TRENDS IN OBS. TEMPS WERE
ADJUSTED UP A FEW MORE DEGREES AHEAD OF A WEAK COLD FRONT AND
SKY GRIDS WERE UPDATED TO ACCOUNT FOR STRATOCUMULUS CLOUD COVERAGE
SOUTHEAST OF PITTSBURGH.
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A 500MB SHORT WAVE
TROUGH SWINGING ACROSS MICHIGAN WITH THE UPPER OHIO VALLEY IN A
SOUTHWESTERLY FLOW. AT THE SURFACE, A 1004MB SURFACE LOW IS
CENTERED ACROSS EASTERN CANADA WITH A 1022MB HIGH CENTERED ACROSS
THE MISSOURI VALLEY. A MOISTURE STARVED COLD FRONT EXTENDS FROM
THE SURFACE LOW INTO THE UPPER OHIO VALLEY AND HAS PUSHED EAST OF
A LINE FROM FRANKLIN SOUTHWEST TO ZANESVILLE. THERE IS WEAK COLD
AIR ADVECTION BEHIND THE FRONT, WITH LITTLE TO SHOW WITH ITS
PASSAGE ASIDE FROM A WIND SHIFT TO WESTERLY AND SOME MID-DECK
CLOUDS BEHIND IT.
THIS AFTERNOON...THE WEAK FRONT WILL PUSH EAST OF THE AREA AND
THE MID-LEVEL FLOW WILL BECOME MORE ZONAL OVERNIGHT. AN ISOLATED
SHOWER MAY CLIP THE WV/MD RIDGES BY EARLY AFTERNOON. OTHERWISE,
DRY FRONTAL PASSAGE WILL OCCUR TODAY. HIGHS TEMPS ARE CLOSEST TO A
HRRR/LAMP BLEND, RANGING FROM THE MID 50S ACROSS THE LOWLANDS
SOUTH AND EAST OF PITTSBURGH TO THE MID 40S ACROSS THE I-80
CORRIDOR.
TONIGHT...THE NAM/HRRR ARE INDICATING THAT WEAK COLD AIR ADVECTION
ALONG WITH THE 850MB FLOW SHIFT TO NORTHWESTERLY WILL BE ENOUGH
FOR A SCHC OF SNOW SHOWERS NORTH OF THE I-80 CORRIDOR. OTHERWISE,
THE SURFACE HIGH WILL BEGIN TO BUILD IN FROM THE WEST TONIGHT WITH
A DRY FORECAST IN PLACE. ONGOING WEAK COLD AIR ADVECTION WILL
ALLOW FOR NOTICEABLY COLDER LOWS TONIGHT, RANGING FROM THE MID TO
UPPER 20S ACROSS THE AREA.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
WEAK SURFACE RIDGE WILL BE ACROSS REGION SUNDAY THROUGH
MONDAY IN A SPLIT FLOW IN THE JET STREAM ACROSS THE U.S. A WEAK
SHORTWAVE WILL SLIDE ACROSS THE EASTERN LAKES SUNDAY INTO SUNDAY
NIGHT WITH AN INCREASE IN CLOUDS BUT NO PRECIPITATION IS EXPECTED.
TEMPERATURES WILL AVERAGE NEAR TO ABOVE SEASONAL NORMS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THERE IS GFS/ECMWF AGREEMENT THAT HIGH PRESSURE WILL CROSS THE UPPER
OHIO VALLEY AND KEEP THE FORECAST DRY MONDAY NIGHT THROUGH TUESDAY.
A CLOSED MID-LEVEL LOW WILL THEN MOVE FROM THE WESTERN GULF STATES
ACROSS THE THE TENNESSEE VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE
CHANCE OF SHOWERS WILL BEGIN TUESDAY NIGHT AS A WARM FRONT AHEAD OF
THE LOW PUSHES NORTHWARD INTO THE AREA. MODEL THICKNESSES WILL WARM
ABOVE CRITICAL THRESHOLDS THAT WOULD BE NEEDED FOR A WINTRY MIX, SO
FORECAST IS FOR ALL RAIN TO BEGIN THE EVENT. TEMPERATURES WILL BE
AROUND 10 DEGREES ABOVE NORMAL THROUGH THE MID-WEEK.
RAIN WILL BE LIKELY FOR AREAS SOUTH AND EAST OF PITTSBURGH WEDNESDAY
INTO WEDNESDAY NIGHT AS THE LOW MOVES ACROSS WEST VIRGINIA AND INTO
THE NORTHEAST. 12Z GFS/00Z ECMWF ARE OFF IN TIMING OF THE COLD AIR
ADVECTION ON THE BACK SIDE OF THIS SYSTEM AND FORECAST SIDES WITH
THE FASTER GFS, TURNING PRECIP OVER TO SNOW SHOWERS ACROSS THE AREA BY
THURSDAY MORNING. CHANCE POPS ARE FORECAST FOR THE RIDGES AND LAKE
EFFECT COUNTIES AS COLD AIR ADVECTION WITH A NORTHWESTERLY FLOW
ALLOWS FOR SOME LINGERING SNOW SHOWERS THURSDAY AND FRIDAY. THE
ARCTIC AIR MASS IN THE WAKE OF THIS SYSTEM WILL BRING TEMPS CLOSER
TO NORMAL VALUES ON THURSDAY, DROPPING TO 5 DEGREES BELOW NORMAL BY
FRIDAY.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
GENERAL VFR CONDITIONS TODAY. WILL CONTINUE WITH A BRIEF MVFR
FORECAST AT MGW AS LOWER MOISTURE IS MOVING ACROSS WV. A WEAK
FRONT HAS PUSHED EAST OF KFKL/KZZV AND WINDS WILL SHIFT FROM
SOUTHWESTERLY TO WESTERLY FOR THE REMAINING TERMINALS WITH THE
PASSAGE OF THE FRONT EARLY THIS AFTERNOON.
OUTLOOK...SATURDAY NIGHT THROUGH WEDNESDAY...
HIGH PRESSURE WILL BUILD IN ON SATURDAY NIGHT WITH GENERAL VFR
CONDITIONS ANTICIPATED UNTIL THE APPROACH OF LOW PRESSURE DURING
THE MID WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED FOR 06Z TAFS
NWS MARQUETTE MI
1049 PM EST SUN JAN 8 2012
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL RIDGE OVER THE
WEST COAST INTO BC/ALBERTA LEAVING WNW FLOW DOWNSTREAM THROUGH SRN
CANADA INTO THE NRN GREAT LAKES. A WEAK SHORTWAVE TROUGH FROM NEAR
THE SW END OF HUDSON BAY TO LAKE SUPERIOR THAT SUPPORTED BAND OF
SNOW SHOWERS ACROSS LAKE SUPERIOR AND NRN UPPER MI WAS EXITING TO
THE EAST. THE NEXT SIGNIFICANT SHRTWV WAS LOCATED OVER NRN MANITOBA.
AT THE SFC...WINDS WERE BACKING W AND SW AS A RIDGE BUILDS TOWARD
THE AREA. THE VIS SATELLITE LOOP SHOWED CLEARING OVER THE SW HALF OF
THE CWA AS DRIER AIR IN THE SFC-850 MB LAYER MOVES IN FROM THE
WEST.
&&
.SHORT TERM...TONIGHT AND MONDAY
THE NRN MANITOBA SHRTWV IS EXPECTED TO DIVE SOUTHEASTWARD TOWARD THE
UPPER GREAT LAKES. A BAND OF MODERATE 700-300 QVECTOR CONV WILL
SPREAD ACROSS THE AREA ALONG WITH A BAND OF FAIRLY STRONG 285K-290K
ISENTROPIC ASCENT FROM 09Z-15Z. HOWEVER...WITH LITTLE MOISTURE
AVBL...THE SFC-850 MB LAYER REMAINS RELATIVELY DRY. THE PATH OF THE
SHRTWV AND MODELS CONSENSUS STRONGEST FORCING AND QPF SUGGEST THAT
THE NORTH AND EAST PORTIONS OF THE CWA HAVE THE BEST CHANCE OF
SEEING SOME LIGHT SNOW. HOWEVER...ANY AMOUNTS ARE EXPECTED TO BE
LIGHT...GENERALLY A HALF INCH OR LESS. LEFTOVER CLOUDS INTO THE
EARLY AFTERNOON MAY DELAY WARMING ENOUGH TO KEEP TEMPS MAINLY
IN THE MID TO UPPER 30S...ESPECIALLY OVER THE EAST.
.LONG TERM /00Z TUE THROUGH NEXT SUN/...
EXPECT WARMER CONDITIONS MONDAY NIGHT AND TUESDAY AS THE UPPER GREAT
LAKES REMAINS IN WARM SECTOR OF LOW PRESSURE SYSTEM SLIDING FROM
MANITOBA INTO ONTARIO. BROKEN MID CLOUDS SHOULD BE AROUND LATE
MONDAY NIGHT INTO TUESDAY MORNING...BUT SOME SUNSHINE SHOULD APPEAR
BY AFTERNOON. GIVEN THE SUNSHINE AND SW WINDS AT THE SFC...TUESDAY
COULD BE ANOTHER DAY WITH NEAR RECORD OR RECORD WARMTH. MIXING TO
950-925MB SUPPORTS HIGHS AOA 40 DEGREES FOR MANY AREAS. KEPT THE
TREND FROM THE PREVIOUS SHIFT TOWARD HIGH END OF BIAS CORRECTED
GUIDANCE WHICH RESULTED IN MAX TEMPS IN MID TO UPPER 40S TOWARD WI
BORDER WHERE SNOW COVER REMAINS PRETTY THIN. RECORD HIGH AT NWS
MARQUETTE FOR TUESDAY IS 42 SET IN 2001. THIS IS EXPECTED TO BE THE
LAST WARMER DAY AT LEAST THROUGH NEXT WEEKEND AS PATTERN BEGINS TO
CHANGE ON WEDNESDAY.
WED THROUGH FRI...MODEL AGREEMENT HAS IMPROVED SINCE YESTERDAY WITH
A STRONG LOW PRESSURE SYSTEM THAT IS SET TO MOVE OVER THE AREA WED
THROUGH FRI. COMPARING THE 12Z/08 GFS...00Z/08 ECMWF...AND
12Z/08 GEM SOLUTIONS...THE GEM IS MORE OF AN OUTLIER SO IT WAS RULED
OUT FOR THIS FORECAST. BOTH THE GFS AND ECMWF BRING A 500MB TROUGH
FROM A CLOSED LOW FROM OVER AK...SHOWING A LOW CLOSING OFF FROM THE
TIP OF THE TROUGH AS IT MOVES INTO THE PACIFIC NW. MODELS THEN
DEPICT THE TROUGH MOVING TOWARD THE CWA BEFORE DEEPENING JUST
UPSTREAM OF THE CWA IN RESPONSE TO JET INTERACTION. THE GFS DEEPENS
THE UPPER TROUGH INTO A CLOSED LOW FASTER THAN THE ECWMF...AND IS
MORE TRANSIENT WITH THE SYSTEM AS IT MOVES S OF THE CWA. THE ECMWF
KEEP AN OPEN WAVE ALOFT UNTIL IT MOVES INTO WI AROUND 00Z FRI...AND
IS ABOUT 12 HOURS SLOWER WITH MOVING THE SYSTEM OUT THAN THE GFS.
THERE IS STILL FAIR POTENTIAL THAT MODELS ARE NOT SETTLED WITH THEIR
SOLUTIONS YET. A BIG REASON MODELS DIVERGE WITH THE TRACK AND
INTENSITY OF THE SYSTEM STARTS BACK WHEN THE TROUGH IS MOVING INTO
THE PACIFIC NW. A LOT WILL DEPEND OF WHAT MODELS DO WITH THE LOW
THAT IS SHOWN BREAKING OFF OF THE TROUGH. MODELS CURRENTLY AGREE
PRETTY WELL THAT THE LOW WILL STAY OFF THE CA COAST FOR A WHILE. IF
THE LOW MOVES FARTHER EAST FASTER...OR DEVELOPS FARTHER EAST...IT
WILL CUTS OFF SOME ACCESS TO COMPONENTS OF BOTH THE NRN AND SRN
STREAM JETS...CAUSING THE MAIN SYSTEM NOT TO STRENGTHEN AS MUCH AND
PROBABLY STAY FARTHER N. HOWEVER...EVEN IF THIS HAPPENS...850MB
TEMPS SHOULD STILL FALL TO AROUND -20C OVER LAKE SUPERIOR. WITH THE
SFC LOW DEEPENING OVER THE LOWER GREAT LAKES...NW BOUNDARY LAYER
WINDS LOOK TO BE THE WAY TO GO...AND THIS IS AGREED UPON WELL BY
MODELS. LIKELY POPS ARE WELL JUSTIFIED AT THIS POINT IN AREAS
FAVORED BY NW FLOW OFF LAKE SUPERIOR. CURRENTLY MODEL CONSENSUS
WOULD ALSO LEAD TO SYNOPTIC SNOW OVER THE REST OF UPPER MI...BUT
THIS IS A LITTLE MORE UNCERTAIN DUE TO UNCERTAINTY IN THE EXACT
TRACK OF THE UPPER LOW. WILL CONTINUE TO HIGHLIGHT THIS POTENTIAL
HEAVY SNOW IN THE HAZARDOUS WEATHER OUTLOOK.
SAT AND SUN...DID NOT DWELL TOO MUCH ON THIS PERIOD DUE TO
INCREASING MODEL VARIABILITY...BUT MODELS CURRENTLY SHOW SLIGHTLY
WARMER 850MB TEMPS STILL COLD ENOUGH FOR LES WITH A GENERALLY NW
WIND...AND A COUPLE OF SHORTWAVES MOVING THROUGH. THIS WOULD LEAD TO
PERIODS OF LES AND SLIGHTLY WARMER...BUT NEAR SEASONAL...TEMPS.
STAYED WITH CONSENSUS MODEL BLEND GIVEN UNCERTAINTY.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
EXPECT VFR CONDITIONS FOR THE REST OF THE FCST PERIOD. LOW LVL WIND
SHEAR WILL CONTINUE OVERNIGHT AS A SW GRADIENT TIGHTENS AHEAD OF LOW
PRESSURE SYSTEM MOVING ACROSS NRN ONTARIO AS A LOW-LVL WIND MAX
MOVES ACROSS THE AREA. BY MON MORNING...GUSTY SOUTHWEST TO WEST
SOUTHWEST ARE EXPECTED. WINDS WILL DIE DOWN BY EVENING.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
LOW PRESSURE IS FORECAST TO MOVE FROM ALBERTA TO JAMES BAY BY
MONDAY. STRONG PRESSURE FALLS NORTH OF LAKE SUPERIOR AND AN
INCREASING PRESSURE GRADIENT IS EXPECTED TO RESULT IN GALE FORCE
SOUTHWEST WINDS OVER MUCH OF LAKE SUPERIOR LATE TONIGHT INTO MONDAY
WITH GALE WINDS SHIFTING WEST ON MONDAY AFTERNOON OVER ERN LAKE
SUPERIOR BEFORE DIMINISHING BLO GALES MON EVENING. WINDS WILL
DIMINISH BY TUESDAY WITH A WEAKENING PRESSURE GRADIENT...BUT WILL
INCREASE OUT OF THE N-NW WEDNESDAY NIGHT INTO FRIDAY AS MUCH COLDER
SPREADS ACROSS THE REGION AND THE PRES GRADIENT TIGHTENS IN THE WAKE
OF A DEEPENING LOW PRESSURE SYSTEM. N/NW WINDS SHOULD REACH GALE OR
NEAR GALE FORCE LATE WED NIGHT INTO FRI MORNING WITH MODERATE HEAVY
FREEZING SPRAY THU NIGHT INTO FRI.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 5 AM TO 4 PM EST MONDAY FOR LSZ267.
GALE WARNING FROM 3 AM TO 7 PM EST MONDAY FOR LSZ266.
GALE WARNING FROM 1 AM EST /MIDNIGHT CST/ TO 11 AM EST /10 AM
CST/ MONDAY FOR LSZ162.
GALE WARNING FROM 1 AM TO 3 PM EST MONDAY FOR LSZ263-264.
GALE WARNING FROM 7 AM TO 7 PM EST MONDAY FOR LSZ265.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED FOR 00Z TAFS
NWS MARQUETTE MI
609 PM EST SUN JAN 8 2012
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL RIDGE OVER THE
WEST COAST INTO BC/ALBERTA LEAVING WNW FLOW DOWNSTREAM THROUGH SRN
CANADA INTO THE NRN GREAT LAKES. A WEAK SHORTWAVE TROUGH FROM NEAR
THE SW END OF HUDSON BAY TO LAKE SUPERIOR THAT SUPPORTED BAND OF
SNOW SHOWERS ACROSS LAKE SUPERIOR AND NRN UPPER MI WAS EXITING TO
THE EAST. THE NEXT SIGNIFICANT SHRTWV WAS LOCATED OVER NRN MANITOBA.
AT THE SFC...WINDS WERE BACKING W AND SW AS A RIDGE BUILDS TOWARD
THE AREA. THE VIS SATELLITE LOOP SHOWED CLEARING OVER THE SW HALF OF
THE CWA AS DRIER AIR IN THE SFC-850 MB LAYER MOVES IN FROM THE
WEST.
&&
.SHORT TERM...TONIGHT AND MONDAY
THE NRN MANITOBA SHRTWV IS EXPECTED TO DIVE SOUTHEASTWARD TOWARD THE
UPPER GREAT LAKES. A BAND OF MODERATE 700-300 QVECTOR CONV WILL
SPREAD ACROSS THE AREA ALONG WITH A BAND OF FAIRLY STRONG 285K-290K
ISENTROPIC ASCENT FROM 09Z-15Z. HOWEVER...WITH LITTLE MOISTURE
AVBL...THE SFC-850 MB LAYER REMAINS RELATIVELY DRY. THE PATH OF THE
SHRTWV AND MODELS CONSENSUS STRONGEST FORCING AND QPF SUGGEST THAT
THE NORTH AND EAST PORTIONS OF THE CWA HAVE THE BEST CHANCE OF
SEEING SOME LIGHT SNOW. HOWEVER...ANY AMOUNTS ARE EXPECTED TO BE
LIGHT...GENERALLY A HALF INCH OR LESS. LEFTOVER CLOUDS INTO THE
EARLY AFTERNOON MAY DELAY WARMING ENOUGH TO KEEP TEMPS MAINLY
IN THE MID TO UPPER 30S...ESPECIALLY OVER THE EAST.
.LONG TERM /00Z TUE THROUGH NEXT SUN/...
EXPECT WARMER CONDITIONS MONDAY NIGHT AND TUESDAY AS THE UPPER GREAT
LAKES REMAINS IN WARM SECTOR OF LOW PRESSURE SYSTEM SLIDING FROM
MANITOBA INTO ONTARIO. BROKEN MID CLOUDS SHOULD BE AROUND LATE
MONDAY NIGHT INTO TUESDAY MORNING...BUT SOME SUNSHINE SHOULD APPEAR
BY AFTERNOON. GIVEN THE SUNSHINE AND SW WINDS AT THE SFC...TUESDAY
COULD BE ANOTHER DAY WITH NEAR RECORD OR RECORD WARMTH. MIXING TO
950-925MB SUPPORTS HIGHS AOA 40 DEGREES FOR MANY AREAS. KEPT THE
TREND FROM THE PREVIOUS SHIFT TOWARD HIGH END OF BIAS CORRECTED
GUIDANCE WHICH RESULTED IN MAX TEMPS IN MID TO UPPER 40S TOWARD WI
BORDER WHERE SNOW COVER REMAINS PRETTY THIN. RECORD HIGH AT NWS
MARQUETTE FOR TUESDAY IS 42 SET IN 2001. THIS IS EXPECTED TO BE THE
LAST WARMER DAY AT LEAST THROUGH NEXT WEEKEND AS PATTERN BEGINS TO
CHANGE ON WEDNESDAY.
WED THROUGH FRI...MODEL AGREEMENT HAS IMPROVED SINCE YESTERDAY WITH
A STRONG LOW PRESSURE SYSTEM THAT IS SET TO MOVE OVER THE AREA WED
THROUGH FRI. COMPARING THE 12Z/08 GFS...00Z/08 ECMWF...AND
12Z/08 GEM SOLUTIONS...THE GEM IS MORE OF AN OUTLIER SO IT WAS RULED
OUT FOR THIS FORECAST. BOTH THE GFS AND ECMWF BRING A 500MB TROUGH
FROM A CLOSED LOW FROM OVER AK...SHOWING A LOW CLOSING OFF FROM THE
TIP OF THE TROUGH AS IT MOVES INTO THE PACIFIC NW. MODELS THEN
DEPICT THE TROUGH MOVING TOWARD THE CWA BEFORE DEEPENING JUST
UPSTREAM OF THE CWA IN RESPONSE TO JET INTERACTION. THE GFS DEEPENS
THE UPPER TROUGH INTO A CLOSED LOW FASTER THAN THE ECWMF...AND IS
MORE TRANSIENT WITH THE SYSTEM AS IT MOVES S OF THE CWA. THE ECMWF
KEEP AN OPEN WAVE ALOFT UNTIL IT MOVES INTO WI AROUND 00Z FRI...AND
IS ABOUT 12 HOURS SLOWER WITH MOVING THE SYSTEM OUT THAN THE GFS.
THERE IS STILL FAIR POTENTIAL THAT MODELS ARE NOT SETTLED WITH THEIR
SOLUTIONS YET. A BIG REASON MODELS DIVERGE WITH THE TRACK AND
INTENSITY OF THE SYSTEM STARTS BACK WHEN THE TROUGH IS MOVING INTO
THE PACIFIC NW. A LOT WILL DEPEND OF WHAT MODELS DO WITH THE LOW
THAT IS SHOWN BREAKING OFF OF THE TROUGH. MODELS CURRENTLY AGREE
PRETTY WELL THAT THE LOW WILL STAY OFF THE CA COAST FOR A WHILE. IF
THE LOW MOVES FARTHER EAST FASTER...OR DEVELOPS FARTHER EAST...IT
WILL CUTS OFF SOME ACCESS TO COMPONENTS OF BOTH THE NRN AND SRN
STREAM JETS...CAUSING THE MAIN SYSTEM NOT TO STRENGTHEN AS MUCH AND
PROBABLY STAY FARTHER N. HOWEVER...EVEN IF THIS HAPPENS...850MB
TEMPS SHOULD STILL FALL TO AROUND -20C OVER LAKE SUPERIOR. WITH THE
SFC LOW DEEPENING OVER THE LOWER GREAT LAKES...NW BOUNDARY LAYER
WINDS LOOK TO BE THE WAY TO GO...AND THIS IS AGREED UPON WELL BY
MODELS. LIKELY POPS ARE WELL JUSTIFIED AT THIS POINT IN AREAS
FAVORED BY NW FLOW OFF LAKE SUPERIOR. CURRENTLY MODEL CONSENSUS
WOULD ALSO LEAD TO SYNOPTIC SNOW OVER THE REST OF UPPER MI...BUT
THIS IS A LITTLE MORE UNCERTAIN DUE TO UNCERTAINTY IN THE EXACT
TRACK OF THE UPPER LOW. WILL CONTINUE TO HIGHLIGHT THIS POTENTIAL
HEAVY SNOW IN THE HAZARDOUS WEATHER OUTLOOK.
SAT AND SUN...DID NOT DWELL TOO MUCH ON THIS PERIOD DUE TO
INCREASING MODEL VARIABILITY...BUT MODELS CURRENTLY SHOW SLIGHTLY
WARMER 850MB TEMPS STILL COLD ENOUGH FOR LES WITH A GENERALLY NW
WIND...AND A COUPLE OF SHORTWAVES MOVING THROUGH. THIS WOULD LEAD TO
PERIODS OF LES AND SLIGHTLY WARMER...BUT NEAR SEASONAL...TEMPS.
STAYED WITH CONSENSUS MODEL BLEND GIVEN UNCERTAINTY.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
EXPECT VFR CONDITIONS FOR THE REST OF THE FCST PERIOD. LOW LVL WIND
SHEAR WILL DEVELOP LATER THIS EVENING AND OVERNIGHT AS SW GRAD
TIGHTENS AHEAD OF LOW PRESSURE SYSTEM MOVING ACROSS NRN ONTARIO AS A
LOW-LVL WIND MAX MOVES ACROSS THE AREA. BY MON MORNING...GUSTY
SOUTHWEST TO WEST SOUTHWEST ARE EXPECTED.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
LOW PRESSURE IS FORECAST TO MOVE FROM ALBERTA TO JAMES BAY BY
MONDAY. STRONG PRESSURE FALLS NORTH OF LAKE SUPERIOR AND AN
INCREASING PRESSURE GRADIENT IS EXPECTED TO RESULT IN GALE FORCE
SOUTHWEST WINDS OVER MUCH OF LAKE SUPERIOR LATE TONIGHT INTO MONDAY
WITH GALE WINDS SHIFTING WEST ON MONDAY AFTERNOON OVER ERN LAKE
SUPERIOR BEFORE DIMINISHING BLO GALES MON EVENING. WINDS WILL
DIMINISH BY TUESDAY WITH A WEAKENING PRESSURE GRADIENT...BUT WILL
INCREASE OUT OF THE N-NW WEDNESDAY NIGHT INTO FRIDAY AS MUCH COLDER
SPREADS ACROSS THE REGION AND THE PRES GRADIENT TIGHTENS IN THE WAKE
OF A DEEPENING LOW PRESSURE SYSTEM. N/NW WINDS SHOULD REACH GALE OR
NEAR GALE FORCE LATE WED NIGHT INTO FRI MORNING WITH MODERATE HEAVY
FREEZING SPRAY THU NIGHT INTO FRI.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 5 AM TO 4 PM EST MONDAY FOR LSZ267.
GALE WARNING FROM 3 AM TO 7 PM EST MONDAY FOR LSZ266.
GALE WARNING FROM 1 AM EST /MIDNIGHT CST/ TO 11 AM EST /10 AM
CST/ MONDAY FOR LSZ162.
GALE WARNING FROM 1 AM TO 3 PM EST MONDAY FOR LSZ263-264.
GALE WARNING FROM 7 AM TO 7 PM EST MONDAY FOR LSZ265.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 PM EST SAT JAN 7 2012
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL NRN STREAM
FLOW THROUGH THE UPPER GREAT LAKES. A WEAK SHORTWAVE THAT HAS HELPED
BOOST LES INTENSITY TODAY WAS EXITING TO THE EAST OF LAKE SUPERIOR.
OTHERWISE...NO SIGNIFICANT SHRTWVS WERE NOTED UPSTREAM THAT WOULD
IMPACT WEATHER THROUGH SUN. AT THE SFC...A TROUGH FRONT WAS NEARLY
STATIONARY ACROSS NRN UPPER MI. 850 MB TEMPS NEAR -14C PROVIDED JUST
ENOUGH INSTABILITY FOR LIGHT LES WITH LOW LEVEL NW FLOW.
&&
.SHORT TERM...TONIGHT AND SUNDAY
WEAKER AND INCREASINGLY ANTICYCLONIC FLOW WITH SFC RDG MOVING IN
FROM THE WEST WILL TEND TO BACK WINDS MORE WRLY LATE TONIGHT INTO
SUNDAY. THE MOST FAVORABLE LOW LEVEL CONV WOULD FOCUS LES OVER THE
KEWEENAW PENINSULA AND FROM MUNISING EASTWARD ALONG THE ERN
SHORELINE. MAINTAINED HIGH CHC TO LIKELY POPS FOR ADDITIONAL LES
ACCUMS OF AN INCH OR LESS OVER THE KEWEENAW PENINSULA AND ERN
ALGER...LUCE AND NRN SCHOOLCRAFT COUNTIES. EXPECT DRY CONDITIONS TO
THE SOUTH.
A BAND OF 275K-280K ISENTROPIC ASCENT AND 900-800 MB FGEN MOVING
INTO THE WEST LATE AND ACROSS THE CWA LATE TONIGHT AND SUN MORNING
COULD PRODUCE SOME LIGHT SNOW WITH MINIMAL ACCUMULATIONS OF A FEW
TENTHS. SO...ONLY SLIGHT CHANCE POPS WERE INCLUDED AWAY FROM LAKE
SUPERIOR. LOW LEVEL BACKING MORE WRLY BY SUNDAY ALONG WITH MARGINAL
LAKE INSTABILITY (850 MB TEMPS CLIMBING TO AROUND -12C) SUPPORT ONLY
LOW CHC POPS FOR LES OVER MAINLY THE KEWEENAW PENINSULA AND
SHORELINE AREAS EAST OF MUNISING. WITH THE LIGHT WIND FIELD
UNCERTAINTY REMAINS WHETHER ANY MESO LOW OR SHORELINE PARALLEL BAND
WILL DEVELOP...PER HIGH RES WRF/ARW.
.LONG TERM /00Z MON THROUGH NEXT SAT/...
STARTING MONDAY AT 00Z THERE WILL BE A BROAD 500MB TROUGH OVER ERN
CANADA/NERN CONUS...WITH A SHARP TROUGH BRANCHING OFF OF THAT FROM
OVER OUR CWA TO THE AZ/NM BORDER...AND A 500MB RIDGE W OF THAT
TROUGH. BY TUESDAY...THE AZ/NM TROUGH WILL CLOSE OFF AND MOVE TO
TX...BREAKING FREE OF THE ERN CANADA TROUGH AS IT MOVES E. ANOTHER
SYSTEM WILL PUSH INTO THE PACIFIC NW...WHICH WILL PUSH THE W COAST
RIDGE OVER THE CWA DURING THE DAY TUESDAY. MODELS HAVE HAD POOR RUN
TO RUN CONTINUITY WITH THE NEXT SYSTEM MOVING IN FOR THE MIDDLE OF
THE WEEK. MODELS BRING AN UPPER TROUGH OFF A CLOSED LOW OVER AK INTO
THE REGION...DEEPENING IT INTO A CLOSED LOW NEAR OR OVER THE CWA
WED. THE CLOSED LOW MOVES OFF TO THE NE THU NIGHT OR FRIDAY...WITH
AN UPPER TROUGH HANGING AROUND E OF THE CWA THROUGH SATURDAY.
FOR MON...A SHORTWAVE WILL MOVE THROUGH THE REGION...BUT THE BEST
DYNAMICS WILL BE FARTHER NE...SO ANY POPS WERE LIMITED TO LAKE
SUPERIO OR ERN UPPER MI. EVEN WITH CLOUD COVER FROM THIS
SYSTEM...HIGH WILL BE IN THE MID TO UPPER 30S WITH WAA FROM THE W
THROUGH THE DAY. 850MB TEMPS AT 00Z MON WILL BE AROUND
-9C...INCREASING TO AROUND 0C BY 00Z TUE.
MON NIGHT AND TUE...AS THE UPPER RIDGE MOVES OVERHEAD TUE...EXPECT
DRY CONDITIONS WITH FEWER CLOUDS...ESPECIALLY BEFORE EVENING.
THICKNESSES WILL BE SLIGHTLY INCREASED TUE...SO HIGHS WILL BE A
COUPLE DEGREES WARMER AROUND 40.
WED THROUGH FRI...AS NOTED PREVIOUSLY...MODELS SHOW INCREASED
DISAGREEMENT AND DECREASED RUN TO RUN CONTINUITY WITH A SYSTEM
EJECTING OUT OF AK. COMPARING THE 12Z/07 GFS...00Z/07 ECMWF...AND
12Z/07 GEM SOLUTIONS...THE GEM WAS RULED OUT SINCE IT SHOWS A FAR
DIFFERENT SCENARIO THAN THE OTHER TWO MODELS. BOTH THE GFS AND ECMWF
BRING A 500MB TROUGH FROM A CLOSED LOW OVER AK...SHOWING A LOW
CLOSING OFF FROM THE TIP OF THE TROUGH AS IT MOVES SE. MODELS THEN
DEPICT THE TROUGH MOVING TOWARD THE CWA BEFORE DEEPENING JUST
UPSTREAM OF THE CWA IN RESPONSE TO JET INTERACTION. THE GFS CLOSES
THE UPPER LOW OFF AS IT MOVES ACROSS THE CENTRAL MANITOBA/ONTARIO
BORDER AROUND 18Z WED...AND MARCHES IT JUST N OF LAKE SUPERIOR
BEFORE MOVING INTO QUEBEC AROUND 06Z FRI. THE STRONGER ECMWF CLOSES
THE LOW OFF OVER THE ND/MANITOBA BORDER AROUND 12Z WED...THEN
CONTINUES TO DEEPEN THE SYSTEM AS IT MOVES TO THE IL/WI BORDER BY
12Z THU...THEN TO THE LOWER GREAT LAKES BY 12Z FRI. SET THE CLOCK
BACK A BIT TO FIND WHERE MODELS START TO DIVERGE WITH THIS SYSTEM.
BACK WHEN THE TROUGH IS MOVING OVER WRN CANADA...THE SLIGHTLY
STRONGER ECMWF IS MUCH FASTER TO CLOSE OFF THAT LOW...WHICH THEN
MOVES S AND STAYS WELL OFF THE CA COAST THROUGH THE EVENT. THE
GFS...ON THE OTHER HAND...CLOSES THE LOW OFF OVER SRN CA...WHICH
LEADS TO THAT LOW MOVING INTO AZ AND NM THROUGH THE EVENT. HAVING
THAT LOW IN PLACE THE GFS PUTS IT CUTS OFF SOME ACCESS TO COMPONENTS
OF BOTH THE NRN AND SRN STREAM JETS...WHICH IS WHY THE SYSTEM DOES
NOT STRENGTHEN AS MUCH AND STAYS FARTHER N WITH THE GFS SOLUTION.
REGARDLESS OF SOLUTION...BOTH MODELS BRING 850MB TEMPS AS LOW AS
-20C OVER LAKE SUPERIOR WITH THE SYSTEM. THE GFS HAS NW BL
WINDS...WHILE THE ECMWF HAS MORE NORTHERLY WINDS SINCE THE SFC LOW
WILL BE MORE TO OUR E. AT THIS POINT...I FEEL COMFORTABLE WITH
LIKELY POPS SINCE CONFIDENCE THAT IT WILL SNOW IS MUCH HIGHER THAN
THE CONFIDENCE OF WHERE THE MOST SNOW WILL FALL. IF THE ECMWF IS
CORRECT...WE COULD BE LOOKING AT VERY SIGNIFICANT SNOWFALL
AMOUNTS...ESPECIALLY IN NORTH WIND SNOWBELTS. THE GFS SOLUTION WOULD
LEAD TO MUCH LOWER SNOWFALL TOTALS THAN THE ECMWF...SINCE THE ECMWF
ALSO CONTRIBUTES A SIGNIFICANT AMOUNT OF SYNOPTIC PRECIP.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
OCCASIONAL LAKE EFFECT SNOW SHOWERS WILL PERSIST AT KCMX THROUGHOUT
THE PERIOD. LOW LEVEL FLOW IS ONSHORE/UPSLOPE...AND TEMPS AT TOP OF
LAKE EFFECT LAYER WILL REMAIN COLD ENOUGH FOR LES. GIVEN LACK OF
SIGNIFICANT DRY AIR FM THE NORTH AND WEST...EXPECT VSBY IN SNOW
SHOWERS TO BE MAINLY IFR THROUGH THIS EVENING.
MVFR CIGS WITH SOME FLURRIES AT TIMES ARE EXPECTED AT KIWD AND KSAW.
DOWNSLOPE WINDS AND DRYING MAY EVEN ALLOW SKIES TO SCATTER OUT AT
KSAW THIS AFTN. BY LATE TONIGHT...WEAK SFC LOW WAVE COULD DRIFT
ACROSS LK SUPERIOR. MAIN IMPACT WILL BE INCREASING CHANCES OF LOWER
CIGS AT ALL THREE TAF SITES.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
LOW PRESSURE IS FORECAST TO SLIDE ACROSS ONTARIO THROUGH MONDAY.
STRONG PRESSURE FALLS NORTH OF LAKE SUPERIOR AND AN INCREASING
PRESSURE GRADIENT IS EXPECTED TO RESULT IN GALE FORCE SOUTHWESTERLY
WINDS OVER MUCH OF LAKE SUPERIOR ON MONDAY. A GALE WATCH REMAIN IN
EFFECT FOR THIS TIME FRAME. WINDS SETTLE DOWN BY TUESDAY WITH
WEAKENING PRESSURE GRADIENT...BUT INCREASE WEDNESDAY INTO THURSDAY
AS LOW PRESSURE SYSTEM/STRONG COLD FRONT PUSH ACROSS THE UPPER GREAT
LAKES REGION. EXACT WIND DIRECTION/SPEEDS ARE UNCERTAIN FOR
WEDNESDAY...BUT EVENTUALLY N/NW WINDS SHOULD REACH GALE OR NEAR GALE
FORCE BY THURSDAY IN WAKE OF THE LOW PRESSURE/COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM LATE SUNDAY NIGHT THROUGH MONDAY AFTERNOON FOR
LSZ162-263>266.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1230 PM CST SAT JAN 7 2012
.UPDATE...MIDDAY WATER VAPOR IMAGERY INDICATES A MID LEVEL SHORT
WAVE OVER WYOMING AND UTAH...MOVING EAST/SOUTHEAST. A MID LEVEL
DRY INTRUSION IS ALSO NOTED ADVANCING EAST/NORTHEAST FROM THE
FOUR-CORNERS REGION INTO THE CENTRAL HIGH PLAINS. MID LEVEL
THERMAL ADVECTION AHEAD OF THIS WAVE IS PROMOTING WIDESPREAD CLOUD
COVER ACROSS THE REGION TODAY. RADAR DATA FROM KUEX ALSO SHOW HIGH
LEVEL RETURNS AROUND 6000FT AGL...BUT DRY LOW LEVELS HAVE
PREVENTED PRECIPITATION FROM BEING OBSERVED AT THE SURFACE THUS
FAR. THE 09Z SREF-MEAN...12Z OPERATIONAL GFS...AS WELL AS THE 00Z
EC ALL INDICATE PRECIPITATION WILL BE REALIZED ACROSS WESTERN
PORTIONS OF THE CWA THIS AFTERNOON AND EARLY THIS EVENING...WITH
THE 12Z NAM KEEPING OUR ENTIRE CWA DRY THROUGH 00Z. SURFACE DEW
POINT DEPRESSIONS AS OF 18Z ARE GENERALLY IN THE 10-15 DEGREE
RANGE...WITH PROXIMITY SOUNDINGS FROM RUC ANALYSIS AND LAPS
INDICATING THIS DRY AIR EXISTS UP TO ABOUT 8000 OR 9000FT AGL.
OBVIOUSLY SOME PRECIPITATION IS MAKING IT AS LOW AS 6000FT AGL PER
KUEX...BUT WITH SUCH DRY AIR THROUGH THE LOWER LEVELS...FINDING IT
HARD TO BELIEVE MUCH IN THE WAY OF PRECIPITATION WILL BE REALIZED
ACROSS OUR CWA THIS AFTERNOON. THAT BEING SAID...WENT AHEAD
DECREASED POPS FOR THIS AFTERNOON. ALSO RELEGATED AFTERNOON POPS
TO LOCATIONS WEST OF HIGHWAY 10...WHICH IS WHERE THE OPERATIONAL
GFS...SREF-MEAN AND EC ALL SUGGEST LOW LEVEL MOISTURE FLUX MAY BE
STRONG ENOUGH TO ALLOW FOR SOME PRECIPITATION.
&&
.PREV DISCUSSION... /ISSUED 1137 AM CST SAT JAN 7 2012/
AVIATION...VFR CONDITIONS EXPECTED THROUGH AT LEAST 08Z...WITH
DETERIORATING CONDITIONS POSSIBLE THEREAFTER. MID AND HIGH LEVEL
CLOUDS WILL CONTINUE OVER THE TERMINAL THROUGH THE NEXT 24 HOURS.
SOME GUIDANCE DOES SUGGEST STRATUS WILL INFILTRATE THE TERMINAL
AROUND 08Z WITH CEILINGS NEAR 400FT AGL. THIS GUIDANCE IS
CURRENTLY IN THE MINORITY HOWEVER GIVEN MOST ALL OTHER MODEL
OUTPUT SUGGEST CEILINGS SHOULD NOT DROP MUCH BELOW 6000FT AGL. LOW
LEVEL THERMAL ADVECTION WILL CERTAINLY BE IN PLACE ACROSS THE AREA
GIVEN THE OVERALL SYNOPTIC SETUP...BUT LIMITED MOISTURE BETWEEN
925MB AND 800MB COULD PREVENT STRATUS FORMATION FROM BEING
REALIZED. CERTAINLY NOT COMFORTABLE IGNORING THE THREAT FOR LOW
CEILINGS ALTOGETHER BUT ALSO NOT READY TO FORECAST LIFR...SO WILL
SPLIT THE DIFFERENCE FOR NOW AND GO MVFR 08Z-18Z. SURFACE WINDS
WILL REMAIN LIGHT THROUGH THE TAF PERIOD. VISIBILITY RESTRICTIONS
ARE NOT CURRENTLY FORECAST THROUGH THE NEXT 24 HOURS...HOWEVER IT
IS WORTH NOTING SOME GUIDANCE ALSO SUGGESTS RESTRICTED
VISIBILITIES WILL BE POSSIBLE AFTER 06Z. CURRENT THINKING IS SKIES
WOULD HAVE TO CLEAR OUT FOR SUFFICIENT SURFACE COOLING AND
SATURATION...AND SINCE THE CURRENT TAF CALLS FOR STRATUS
DEVELOPMENT WILL GO AHEAD AND HOLD OFF ON VISIBILITY RESTRICTIONS
FOR NOW. THE POSSIBILITY FOR FOG DEVELOPMENT WILL NEED TO BE
MONITORED HOWEVER SHOULD STRATUS FAIL TO MATERIALIZE EARLY SUNDAY.
PREV DISCUSSION... /ISSUED 359 AM CST SAT JAN 7 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. COOLER
WEATHER...ALTHOUGH STILL WARMER THAN NORMAL...IS EXPECTED THIS
WEEKEND. IN ADDITION...LIGHT SNOW OR FLURRIES WILL BE POSSIBLE
LATE THIS AFTERNOON THROUGH SUNDAY MORNING...ESPECIALLY ALONG THE
I-80 CORRIDOR WEST OF GRAND ISLAND.
FORECAST MODELS HAVE BACKED OFF OF SNOWFALL AMOUNTS FOR
TONIGHT...AND WE WERE NOT EXPECTING MUCH TO BEGIN WITH.
PRECIPITATION TYPE WILL LIKELY BE ALL SNOW ALTHOUGH THERE COULD BE
A BRIEF PERIOD OF SPRINKLES OR VERY LIGHT RAIN THIS AFTERNOON
ACROSS THE WEST PRIOR TO CHANGING OVER. THE SFC WET BULB
TEMPERATURE WILL QUICKLY GO BELOW FREEZING AS THE VERTICAL PROFILE
SATURATES AND PRECIPITATION BEGINS. THE WARMEST LAYER IS THE SFC
SO IF THE SFC WET BULB TEMPERATURE IS AROUND OR BELOW FREEZING
THEN ALL OR NEARLY ALL OF ANY PRECIPITATION THAT FALLS SHOULD FALL
AS SNOW.
THERE ARE SEVERAL FACTORS THAT WILL KEEP SNOW ACCUMULATIONS LESS
THAN 1 INCH...AND LIKELY EVEN LESS THAN THAT AT ONLY A DUSTING UP
TO A HALF INCH. FIRST...THIS IS A FAST MOVING STORM SYSTEM COMING
OUT OF THE PACIFIC NORTHWEST AND THE BULK OF THE LIFT/FORCING
WITH THIS SYSTEM WILL BE ASSOCIATED WITH THE UPPER LOW AS IT CUTS
OFF TO OUR SOUTHWEST ACROSS PORTIONS OF COLORADO AND NEW MEXICO.
SECOND...THE SYSTEM IS MOISTURE STARVED DUE TO ITS TRACK OVER THE
ROCKIES AND IT FAILS TO TAP INTO ANY KIND OF GULF MOISTURE. SO
MOISTURE AVAILABILITY WILL BE AN ISSUE. THE FACT THAT THE FORECAST
MODELS ARE ALSO DECREASING QPF VALUES AS THE STORM APPROACHES IS
NOT A GOOD SIGN FOR ANY SNOW LOVERS OUT THERE. CONSEQUENTLY...WILL
BE CALLING FOR A LESS THAN 50/50 CHANCE OF ACCUMULATING SNOW LATE
THIS AFTERNOON INTO SUNDAY MORNING. THE MOST FAVORABLE TIME FRAME
AND LOCATION FOR SEEING SNOW WILL BE LATE THIS AFTERNOON AND
EVENING FOR SOUTHERN NEBRASKA LOCATIONS WEST OF HWY 281. FOR
EASTERN ZONES IT WILL PROBABLY ONLY BE A FEW FLURRIES OR A BRIEF
PERIOD OF VERY LIGHT SNOW LATER TONIGHT.
THE SHORT WAVE IS QUICK TO MOVE OUT OF THE AREA DURING THE DAY ON
SUNDAY...BUT TEMPERATURES WILL REMAIN COOL.
UPPER LEVEL RIDGING AND SUBSEQUENT WARM AIR MOVING IN ALOFT WILL
HELP TEMPERATURES CLIMB BACK TO AROUND 50 BY MONDAY. WENT ABOVE
MOST MODEL GUIDANCE AS THAT HAS BEEN THE TREND LATELY GIVEN OUR
LACK OF SNOW COVER...WHICH SHOULD STILL BE THE CASE ON MONDAY.
LONG TERM...TUESDAY THROUGH FRIDAY. MAIN FORECAST CONCERN WILL BE
TEMPERATURES. A COLD FRONT MOVES THROUGH THE FORECAST AREA TUESDAY
AFTERNOON AND EVENING. TUESDAY WILL CONTINUE TO BE MILD AHEAD OF THE
COLD FRONT. THE COLDER AIR DOES NOT REALLY MOVE INTO THE FORECAST
AREA UNTIL WEDNESDAY WHEN THERE WILL BE LITTLE IN THE WAY OF A
DIURNAL RISE DURING THE DAY. IN ADDITION TO THE COLD AIR THERE WILL
ALSO BE BREEZY CONDITIONS TUESDAY NIGHT AND INITIALLY ON WEDNESDAY
BEFORE WINDS ALOFT DIMINISH SOME. THE COLD AIR COMES IN STRONG
WEDNESDAY NIGHT AS COLD HIGH PRESSURE SETTLES INTO THE AREA. COOLER
TEMPERATURES LINGER INTO THURSDAY BUT WARM ADVECTION STARTS TO WARM
THINGS BACK UP AGAIN THURSDAY NIGHT INTO FRIDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/AVIATION...BRYANT
SHORT TERM...WESELY
LONG TERM...BERG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
645 PM EST SUN JAN 8 2012
.SYNOPSIS...
A FRONT WILL REMAIN STALLED ACROSS THE AREA THROUGH MONDAY
BEFORE BEING PUSHED OFF TO THE SOUTH ON TUESDAY. A STRONGER LOW
PRESSURE SYSTEM WILL MOVE ACROSS OUR REGION ON WEDNESDAY. THIS
WILL BRING A BETTER CHANCE OF RAIN. HIGH PRESSURE WILL FOLLOW
THURSDAY AND FRIDAY.
&&
.NEAR TERM/THROUGH TONIGHT/...
AS OF 630 PM SUNDAY...WE HAVE MADE SOME SUBSTANTIAL CHANGES TO THE
FORECAST TONIGHT DEALING MAINLY WITH INCREASED CLOUD COVERAGE AND
RAINFALL CHANCES ACROSS THE NORTHERN HALF OF OUR FORECAST AREA. A
NEARLY-STATIONARY FRONT EXTENDS FROM JUST SOUTH OF GEORGETOWN ACROSS
KINGSTREE AND INTO THE SC MIDLANDS NORTH OF COLUMBIA. A SHALLOW COOL
AIRMASS NORTH OF THE FRONT HAS TEMPERATURES GENERALLY IN THE 50S
WITH DEWPOINTS IN THE 40S...WHILE TO THE SOUTH THE AIRMASS IS
TYPIFIED BY TEMPERATURES IN THE 60S AND DEWPOINTS IN THE 50S.
SHOWERS HAVE DEVELOPED ALONG AND NORTH OF THE BOUNDARY FROM THE
CAROLINA SANDHILLS REGION ALL THE WAY WEST INTO UPSTATE SOUTH
CAROLINA AND ADJACENT PORTIONS OF NORTHEAST GEORGIA. LINEAR
EXTRAPOLATION AND THE LATEST SEVERAL HRRR MODEL RUNS SHOW THIS
RAINFALL AFFECTING PORTIONS OF OUR FORECAST AREA THROUGH MIDNIGHT.
WE HAVE INCREASED POPS TO 55-70 PERCENT ALONG AND NORTH OF A LINE
FROM FLORENCE TO MARION...WHITEVILLE AND BURGAW. SOUTH OF THIS AREA
POPS ARE GENERALLY IN THE 40-50 PERCENT RANGE UNTIL YOU GET INTO THE
GEORGETOWN/MURRELLS INLET/MYRTLE BEACH VICINITY WHERE 20-30 PERCENT
CHANCES APPEAR MORE APPROPRIATE. PRECIPITATION IS CONVECTIVE IN
NATURE...ALTHOUGH THROUGH A FAIRLY SHALLOW LAYER OF THE ATMOSPHERE
OWING TO SMALL ELEVATED INSTABILITY ON THE ORDER OF 100-200 J/KG.
SINCE THE CONVECTION IS ELEVATED AND PARCELS WILL NOT "FEEL" ANY
INCREASED HELICITY FROM THE BACKED LOW-LEVEL FLOW THERE SHOULD BE
LITTLE CONVECTIVE ORGANIZATION AND WE ARE NOT CONCERNED ABOUT
SEVERE POTENTIAL OVERNIGHT.
NO CHANGES WERE MADE TO THE PREVIOUS LOW TEMPERATURE FORECASTS WHICH
ARE IN GENERAL AGREEMENT WITH THE 18Z GFS MOS.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...ABOVE NORMAL TEMPERATURES TO CONTINUE THROUGH
THE PERIOD. PREVIOUSLY STALLED FRONT LYING E/W ACROSS THE REGION
WILL LIFT SLOWLY TO THE N MONDAY AFTERNOON AND EVENTUALLY TAKE THE
MOISTURE ALONG WITH IT. THIS MAY NOT BE BEFORE BRINGING A LITTLE
LIGHT RAIN MAINLY OVER NRN ZONES. A LOW AMPLITUDE UPPER TROUGH WILL
SWING THROUGH MONDAY NIGHT AND PUSH THE BOUNDARY BACK TO THE SOUTH
AGAIN. THIS ALLOWS FOR SOME DRY AIR ADVECTION. THERE IS ALSO SOME
WEAK CAA...BUT ITS EFFECTS WILL BE LARGELY OFFSET BY THE ADDED
INSOLATION CAUSED BY A DECREASE IN CLOUD COVER.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...TWO MAIN POINTS TO THE EXTENDED FORECAST...THE
SYSTEM IMPACT THE AREA WED INTO THU AND COLD TEMPERATURES LATE IN
THE PERIOD. CONCERNING THE EARLY SYSTEM THERE IS MORE AGREEMENT THAN
YESTERDAY AND CONFIDENCE IS HIGHER. HELD ONTO LIKELY POP FOR WED BUT
DID INCREASE WED NIGHT POP...ESPECIALLY ACROSS NC...GIVEN THE
SLOWING TREND SEEN IN THE MEDIUM RANGE GUIDANCE. DEEP
MOISTURE...ENHANCED DIVERGENCE ALOFT...AND INSTABILITY WITHIN THE
WARM SECTOR SHOULD PRODUCE A SIGNIFICANT RAINFALL EVENT FOR THE
AREA. NO COLD ADVECTION FOLLOWING THE COLD FRONT...FLOW REMAINS
SOUTHWEST AHEAD OF SIGNIFICANT 5H TROUGH DROPPING INTO THE CENTRAL.
DRY ARCTIC COLD FRONT WILL MOVE ACROSS THE AREA ON FRI. TIMING
STILL REMAINS AN ISSUE...MAKING THU NIGHT/FRI TEMPS TRICKY BUT AIR
MASS BEHIND THE FRONT WILL DROP TEMPERATURES WELL BELOW CLIMO. 850
TEMPS AND THICKNESS SUGGEST HIGH STAYING THE 40S WITH LOWS IN THE
UPPER 20S FOR THE WEEKEND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...UNSETTLED WEATHER THROUGH THE VALID PERIOD AS A
STATIONARY FRONT AND UPPER-LEVEL FEATURES BRING MVFR AND IFR
RESTRICTIONS...WITH LOW CIGS...RAIN SHOWERS...AND FOG.
CURRENT RADAR DEPICTS AN AREA OF SHOWERS STRETCHED ACROSS THE
WESTERN EDGES OF OUR WARNING AREA...AFFECTING THE INLAND SITES.
EXPECT THIS TREND TO CONTINUE THROUGH THE NIGHT INTO THE
MORNING...WITH -RA EVENTUALLY AFFECTING THE COASTAL SITES AS WELL.
ANTICIPATE RAIN TO BE OVERALL LIGHT...BUT CANNOT RULE OUT ISOLATED
HEAVY SHOWERS...WHICH WILL REDUCE VISIBILITY TEMPORARILY. GIVEN
MODEL RUNS...FCST SOUNDINGS...AND TIME-HEIGHT ANALYSIS...ANTICIPATE
MVFR CONDITIONS TO DEVELOP AT THE INLAND TERMINALS...AGAIN
INFILTRATING INTO THE COASTAL TERMINALS THROUGH THE OVERNIGHT HOURS.
FOR NOW HAVE KEPT PERIODS OF IFR AND FOG DEVELOPMENT...GIVEN TRENDS
CONTINUING IN MODEL ANALYSIS. IFR COULD POTENTIALLY LINGER THROUGH
MUCH OF MONDAY MORNING...EVENTUALLY LIFTING TO MVFR BY EARLY
AFTERNOON. COULD SEE A TREND TOWARD VFR BY THE END OF THE VALID
PERIOD...HOWEVER CIGS WILL STILL BE NEAR 3KFT...IF NOT ACTUALLY
LOWER.
WINDS OVERNIGHT WILL BE MAINLY LIGHT AND VARIABLE...INCREASING BY
MONDAY AFTERNOON. ANTICIPATE GENERALLY WEST-NORTHWEST AOB 8
KTS...BECOMING LIGHT AFTER SUNSET
EXTENDED OUTLOOK...MODERATE CONFIDENCE OF ISOLATED THUNDERSTORMS AND
TEMPO IFR WEDNESDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 630 PM SUNDAY...BASED ON LIMITED OBSERVATIONS IT APPEARS THE
NEARLY-STATIONARY FRONT IS LOCATED JUST SOUTH OF GEORGETOWN PERHAPS
IN THE VICINITY OF THE SOUTH SANTEE RIVER ENTRANCE. WINDS NORTH OF
THIS BOUNDARY ARE GENERALLY FROM THE EAST OR NORTHEAST WITH SPEEDS
10 KNOTS OR LESS. WINDS ARE A LITTLE STRONGER NORTH OF CAPE FEAR
WHERE SOME RECENT 15 KNOT GUSTS HAVE BEEN REPORTED AT THE OFFSHORE
WRIGHTSVILLE BEACH BUOY. THE FRONT IS EXPECTED TO MOVE ONLY A LITTLE
NORTHWARD OVERNIGHT...MAKING IT TO THE MYRTLE BEACH VICINITY BY 4 AM
MONDAY. SOUTH OF THE FRONT WIND DIRECTIONS WILL VEER TO THE SOUTH OR
SOUTHWEST...WITH NORTHEASTERLY FLOW CONTINUING NORTH OF THE FRONT.
FORTUNATELY WIND SPEEDS ARE EXPECTED TO AVERAGE AROUND 10 KNOTS
OVERNIGHT...PERHAPS EVEN LESS NEAR THE ACTUAL FRONT ITSELF. SEAS AT
ALL NEARBY OBSERVATION PLATFORMS ARE AROUND 2 FEET THIS EVENING...
AND LITTLE CHANGE IS EXPECTED OVERNIGHT.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...A COLD FRONT WILL BISECT THE WATERS N TO S ON
MONDAY ALTHOUGH THE BOUNDARY WILL SHOW A SLIGHT NORTHWARD DRIFT AS
THE DAY WEARS ON. AS AN UPPER DISTURBANCE SWINGS ACROSS THE
NORTHEAST MONDAY NIGHT LOW PRESSURE WILL DEVELOP OFF THE MID
ATLANTIC COAST AND QUICKLY TRANSLATE EASTWARD. THIS WILL HELP TO
PUSH THE FRONT BACK TO THE SOUTH AGAIN AND A NORTHERLY WIND WILL
SPREAD ACROSS THE WATERS ON TUESDAY. NOT MUCH OF A WINDOW OF
OPPORTUNITY FOR AN INCREASE IN WIND WITH THIS SETUP HOWEVER AS THE
SURFACE HIGH SOON BECOMES ESTABLISHED ACROSS THE CAROLINAS BY THE
EARLY AFTERNOON HOURS. THIS PAIRED WITH THE GENERAL OFFSHORE WIND
DIRECTION FOR MOST OF THE PERIOD WILL KEEP SEAS FAIRLY SMALL. 2 TO
3 FT SEAS TO START THE PERIOD MAY GROW SLIGHTLY MONDAY NIGHT BUT
WILL THEN DIMINISH IN SIZE FOR TUESDAY AND TUESDAY NIGHT.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...HEADLINES WILL LIKELY BE REQUIRED WED AND WED
NIGHT. STRONG SOUTHERLY FLOW AHEAD OF AND BEHIND THE COLD FRONT THAT
IS EXPECTED TO CROSS THE WATERS LATE WED WILL BUILD SEAS OVER 6 FT.
AHEAD OF THE FRONT FLOW WILL BE SOUTHEAST...BETWEEN 20 AND 25
KT...WITH WINDS SHIFTING TO SOUTHWEST BEHIND IT. HEADLINES MAY NEED
TO CONTINUE INTO THU...MAINLY NC WATERS...GIVEN 15 TO 20 KT
SOUTHWEST FLOW. SOUTHWEST FLOW CONTINUES THU NIGHT AND FRI...THOUGH
WITH LOWER SPEEDS AS GRADIENT RELAXES. AN ARCTIC FRONT CROSSES THE
WATERS LATE IN THE PERIOD WITH STRONG OFFSHORE FLOW DEVELOPING.
SUSTAINED WINDS WILL BE CLOSE TO REQUIRING A SCA HEADLINE AT THE END
OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...III
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1029 PM EST SUN JAN 8 2012
.SYNOPSIS...
WEAK DISTURBANCE BRINGS LIGHT RAIN TO MAINLY THE MOUNTAINS LATE
TONIGHT AND MONDAY. HIGH PRESSURE TUESDAY. LOW PRESSURE WEDNESDAY.
COLDER AIR ARRIVES ON THURSDAY ON GUSTY WINDS AND LASTS INTO WEEKEND.
&&
.NEAR TERM /THROUGH MONDAY/...
MADE SOME CHANGES TO THE FORECAST WEATHER THIS EVENING. BASED ON
NEW NAM AND RUC SOUNDINGS...WHICH INDICATE MORE SATURATION IN THE
ATMOSPHERE AND CRYSTAL GROWTH ZONE...AS WELL AS A LAYER AROUND
850MB OF TEMPERATURES NEAR 1C...DID ADD SLEET WORDING TO THE
FORECAST FOR THE CENTRAL AND NORTHERN MOUNTAIN ZONES...AND BROUGHT
THE CHANCES FOR FREEZING AND/OR MIXED PRECIPITATION FARTHER SOUTH
TOWARDS AREAS SUCH AS BKW. AS PREVIOUSLY DISCUSSED...STILL
EXPECTING LIGHT QPF...AND NO MAJOR IMPACTS ARE EXPECTED.
PREVIOUS DISCUSSION FOLLOWS...
MID CLOUDS ALREADY ENCROACHING ON THE COALFIELDS...IN AN AREA OF
H700 MOISTURE CONVERGENCE. NOT EXPECTING THESE TO HEAD MUCH
FURTHER NORTH IN THE NEAR TERM.
MIDLEVEL FLOW OVER CWA REMAINS ZONAL UNTIL THE VERY END OF THIS
PERIOD...WHEN A FLATTENING SHORTWAVE DROPS INTO THE MIDDLE OHIO
VALLEY. MODELS SIMILAR ON TIMING BUT NON-US MODELS ARE A BIT
STRONGER. GOING TO PLAY A MIDDLE OF THE ROAD APPROACH...GOING WITH
POTENTIALLY MORE WIDESPREAD QPF THAN THE NAM/GFS BUT NOT QUITE AS
MUCH AS ECMWF.
DEPARTING SURFACE HIGH WILL HELP TO INDUCE SOUTHEAST FLOW BY 06Z
TONIGHT...HELPING CLOUDS INCREASE AND POSSIBLY GENERATING SOME LIGHT
RAIN. THIS SHOULD SLOWLY EXPAND NORTH AND WEST...EVENTUALLY
REACHING NEAR A CRW/EKN LINE DURING MONDAY MORNING AS THE SHORTWAVE
APPROACHES. MAX COVERAGE WILL BE AROUND 18Z MONDAY BEFORE
DECREASING AS THE MIDLEVEL WAVE PUSHES EAST. OVERALL QPF LOOKS
LIGHT ONCE AGAIN...LESS THAN A QUARTER OF AN INCH.
ONE CONCERN IS POTENTIAL FOR A TOUCH OF FZRA IN SOME OF THE DEEPER
EASTERN VALLEYS FOR A FEW HOURS EITHER SIDE OF SUNRISE MONDAY
MORNING. H850 TEMPS WILL BE ABOVE ZERO FOR THE MOST PART WITH
SUFFICIENT WARM DEPTH FOR FULL MELTING. SURFACE DEWPOINTS IN THE
20S POINT TO DECENT WET-BULB POTENTIAL LATE TONIGHT...AND EVEN
LEANING TOWARDS THE WARMER MET NUMBERS...COULD EASILY SEE LOCATIONS
LIKE THE GREENBRIER VALLEY DROPPING BELOW FREEZING AND GENERATING
SUPERCOOLED RAINDROPS. THUS...WILL HAVE FREEZING RAIN POSSIBILITIES
IN MAINLY WEBSTER/POCAHONTAS/RANDOLPH COUNTIES. WITH POPS AND QPF
LOW...DO NOT SEE A NEED FOR A HEADLINE AT THIS TIME.
LEANED TOWARD THE COOLER MET FOR MONDAY TEMPS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
WEAK S/W TROF AND EVEN WEAKER SURFACE WAVE MOVE OUT MON NT...TAKING
OUT ANY LIGHT PRECIPITATION WITH IT. HIGH PRESSURE CROSSES TUE
BENEATH CONFLUENT FLOW ALOFT.
A SOUTHERN STREAM UPPER LEVEL LOW NOW IN THE SWRN U.S. SEPARATES
FROM A NORTHERN STREAM S/W TROF AND APPROACHES THE FORECAST AREA IN
WHAT ALMOST BECOMES A REX BLOCK AS THE NEXT NORTHERN STREAM S/W TROF
WILL EVENTUALLY FALL IN BEHIND IT. THIS SLOWS ITS APPROACH...SO
DELAYED THE ONSET UNTIL AROUND DAYBREAK UPSTREAM AND NOON OR LATER
DOWNSTREAM AS THE SYSTEM MOVES NE INTO THE AREA.
DECENT DYNAMICS ASSOCIATED WITH THIS UPPER LEVEL LOW AND ORGANIZED
SYSTEM OVERALL OUGHT TO GIVE RISE TO AROUND ONE INCH TOTAL
RAINFALL. HAVE CLOSE TO 3/4 OF AN INCH S WED AS THE SYSTEM MOVES
IN. CONTINUING THE IMPACT MENTION IN THE RWS BUT THIS WILL BE SHORT
OF HWO/FFA THRESHOLDS AS THE SYSTEM KEEPS ON MOVING.
BLENDED IN THE MAV TO LOWER LOWS MON NT ALTHOUGH COULD SEE THE EVEN
LOWER MET PANNING OUT UNDER CLEAR...CALM CONDITIONS. DID BLEND IN
THE MET TO LOWER LOWS TUE NT...THE MAV BEING SIMILAR IN THIS CASE AS
WELL AS ON HIGHS TUE AND WED...WHERE BLENDED IN THE MET TO LOWER
VALUES A BIT IN STABLE AIR TUE AND RAIN WED.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MAIN SUPPORT ALOFT STILL MOVING THROUGH WEDNESDAY EVENING. AS LIKE
24 HOURS...THE 12Z GFS RUN IS THE STRONGEST ON THE SUPPORT AND AS A
RESULT THE HEAVIEST ON ITS RAINFALL. MAY BE A MAXIMUM RAINFALL
ALONG THE OHIO RIVER COUNTIES AND ANOTHER ON THE SE UPSLOPE IN THE
CENTRAL WV MOUNTAINS. WILL LEAVE IMPACT FOR RAIN IN THE CRWRWSRLX
BUT NO HAZARD FOR FLOODING IN THE HAZARDOUS WEATHER OUTLOOK...SINCE
STILL A PROGRESSIVE SYSTEM AND LITTLE OR NO SNOW PACK LEFT.
PRECIPITABLE WATER STILL PEAKING AROUND AN INCH.
STILL THINKING THE COLDER AIR WILL BE TAKING ITS TIME MOVING IN. SO
AS YESTERDAY...KEPT MINIMUM TEMPERATURES AOA MOS GUIDANCE WEDNESDAY
NIGHT. WILL HAVE TEMPERATURES FALLING THURSDAY AFTERNOON.
LIKE 24 HOURS AGO...THE TREND TO KEPT THE COLDER AIR HERE THROUGH
THE WEEKEND STILL EXISTS. SO KEPT TEMPERATURES COLDER THAN OUR HPC
MEDIUM RANGE SUPPORT. SEVERAL SMALL DISTURBANCE AROUND THE 500 MB
TROF...OR CLOSED LOW...IN SRN GREAT LAKES INTO SATURDAY. SO THE
SNOW SHOWER ACTIVITY MAY COME AND GO FRIDAY INTO SATURDAY. HAVE KEPT
POPS HIGHER THAN GUIDANCE MAINLY CRW ON N-NE. HOWEVER...THE MID AND
LOW LEVEL FLOW MAINLY WEST AND WESTNORTHWEST IN THIS PATTERN.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
00Z MONDAY THROUGH 00Z TUESDAY...
MOISTURE WILL GRADUALLY CREEP NORTH AND EAST OVERNIGHT...CREATING
BROKEN TO OVERCAST CIGS AREA WIDE AFTER 06Z. SOME LIGHT RAIN MAY
SHOW UP ACROSS SOUTHERN WEST VIRGINIA LATE TONIGHT...ESPECIALLY
AFTER 09Z AND ALONG EAST-FACING SLOPES. CIGS WILL FALL TO MVFR IN
THE MOUNTAINOUS COUNTIES TOWARD DAYBREAK...WITH ISOLD IFR
POSSIBLE. THERE COULD BE A TOUCH OF FZDZ OR EVEN LIGHT SNOW IN
SOME OF THE DEEPER VALLEYS LIKE THE GREENBRIER BETWEEN 08-14Z.
CONDITIONS WILL IMPROVE AFTER 22Z...FOR A GRADUAL RETURN OF VFR
CONDITIONS MONDAY NIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: RAIN AND WORSENING CONDITIONS COULD BE A BIT
MORE WIDESPREAD THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 01/09/12
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EST 1HRLY 21 22 23 00 01 02 03 04 05 06 07 08
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H M H M M H
EKN CONSISTENCY H H H H H H H H H H M M
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z TUESDAY...
IFR IN RAIN WED AND WED NT...AND IN RAIN AND SNOW SHOWERS THURSDAY
AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/CL/TRM
NEAR TERM...SL/CL
SHORT TERM...TRM
LONG TERM...KTB
AVIATION...SL
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1013 PM MST FRI JAN 6 2012
.AVIATION...06Z TAFS
VFR CONDITIONS ARE EXPECTED THROUGH SATURDAY.
&&
.PREV DISCUSSION... /ISSUED 217 PM MST FRI JAN 6 2012/
DISCUSSION...
VERY FLAT LONG WAVE RIDGE IS AT ABOUT 125W THIS MORNING WITH
LARGELY ZONAL FLOW FROM THE DATE LINE TO THE EAST COAST OF THE US.
SHORT WAVE TROFS WERE NEAR LAKE WG AND SOUTH WEST WARD AND
APPROACHING THE WEST COAST OF CANADA. LONG WAVE RIDGE WILL REBUILD
AS THE SHORT WAVE TROF MOVES EAST WARD...SPLITTING INTO TWO PARTS.
THE SOUTHERN PORTION HEADS FOR AZ/NM WHILE THE NORTHERN PORTION
MOVES ACROSS THE NORTHERN ROCKIES AND LARGELY SHEARS OUT.
THE 1000 TO 500 MB MEAN TEMPERATURE ANOMALY AT RAPID CITY THIS
MORNING IS ABOUT +3C WITH SLIGHTLY BELOW NORMAL TEMPS OVER NORTH
WEST MT. THE ONLY REALLY COLD AIR LIES OVER WESTERN AK.
THE NORTHERN SHORT WAVE TROF CROSSES OUR AREA SUNDAY AM WITH
LITTLE INFLUENCE ON OUR WEATHER.
BRISK WINDS HAVE KEPT TEMPERATURES DOWN TODAY...BUT WILL BE QUICK
TO DIE OFF THIS EVENING AS PRESSURES RISE TO THE EAST AND BEGIN TO
FALL A BIT TO THE WEST CUTTING BACK ON THE PRESSURE GRADIENT. TEMPERATURES
WILL BE QUICK TO FALL DURING THE EVENING HOURS...BUT INCREASING
MOISTURE EVIDENT ON THE WATER VAPOR LOOP AND A BIT OF WARM
ADVECTION AT 700 MB WILL LEAD TO SOME INCREASE IN HIGH AND MID
CLOUDINESS LATER TONIGHT LIKELY SLOWING TEMPERATURE FALLS EARLY AM.
BOTH NAM AND RUC FORECAST SOUNDINGS SHOW THIS INCREASE IN MOISTURE
AND CLOUDINESS.
DRYING IS SHOWN ON THE SOUNDINGS LATE SATURDAY EVENING IN SPITE OF
APPROACH OF THE SHORT WAVE TROF. SURFACE WINDS ARE EXPECTED TO
REMAIN QUITE LIGHT THROUGH THE PERIOD.
EXTENDED...UPPER LEVEL RIDGE CROSSES THE NORTHERN PLAINS EARLY NEXT
WEEK. TEMPERATURES WILL REMAIN ABOVE SEASONAL AVERAGES THROUGH
TUESDAY. STRONG UPPER TROF AND ASSOCIATED SURFACE COLD FRONT CROSSES
THE AREA TUESDAY BRINGING A CHANCE OF RAIN OR SNOW TUESDAY INTO
TUESDAY NIGHT. MODELS SEEM TO BE TRENDING EARLIER WITH THE
TIMING...SO WILL WATCH FOR POP ADJUSTMENTS. SYSTEM SHIFTS EAST
QUICKLY WITH AREA REMAINING UNDER FAST NORTHWEST FLOW THROUGH
MIDWEEK. BOTH GFS AND EC TRY TO BUILD WESTERN RIDGE BACK ACROSS THE
ROCKIES FOR THE END OF THE WEEK.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...WFO UNR
LONG TERM....WFO UNR
AVIATION...HELGESON
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
956 PM CST SUN JAN 8 2012
.AVIATION...
UPDATED TO INCLUDE VICINITY THUNDERSTORMS 5Z-9Z WITH CONVECTION
NOW FORMING TO THE SOUTHWEST OF METROPLEX.
.../PREVIOUS AVIATION DISCUSSION/...
MVFR CIGS OVER THE METROPLEX ARE BEGINNING TO BREAK UP AND WE
SHOULD SEE A PERIOD OF VFR FOR THE NEXT FEW HOURS. RAIN WILL
DEVELOP OVER THE REGION FROM THE SOUTH THIS EVENING...AND AS IT
REACHES THE TAF SITES CIGS WILL FALL AS LOW LEVELS SATURATE. WILL
HAVE MVFR FOR METROPLEX SITES STARTING AT 4Z...AND IFR PREVAILING
AFTER 7Z. SHOWERS AND IFR CIGS WILL PREVAIL AT ALL SITES THROUGH
TOMORROW AFTERNOON...WITH A POSSIBLE BREAK/END IN THE RAIN BY
SUNSET TOMORROW. VSBY MAY BECOME MORE RESTRICTED DURING PERIODS OF
HEAVIER RAIN...BUT WILL PREVAIL 5SM. MOST OF THE ACTIVITY SHOULD
BE SHOWERS...BUT ISOLATED THUNDERSTORMS ARE POSSIBLE. DUE TO THE
ISOLATED NATURE OF STORMS WILL HOLD OFF ON FORECASTING THEM
RIGHT NOW...BUT THE BEST TIME FRAME FOR THUNDER AT TAF SITES IS
PROBABLY BETWEEN 8-12Z.
FOR WACO...MVFR CIGS ARE ALREADY PREVAILING AND EXPECT RAIN TO
ARRIVE A COUPLE OF HOURS SOONER. IFR SHOULD START AROUND 6Z.
THREAT FOR STORMS A LITTLE HIGHER IN WACO THROUGH THE NEXT 12-18
HOURS...BUT NOT HIGH ENOUGH TO FORECAST THEM JUST YET. WILL AMEND
TAF FOR THUNDER WHEN IT BECOME MORE APPARENT.
TR.92
&&
.UPDATE...
OVERALL THE CURRENT FORECAST WAS ON TRACK BUT DID MAKE SOME MINOR
ADJUSTMENTS TO POPS AND TO WARM OVERNIGHT LOWS ACROSS THE REGION.
THE UPPER LEVEL LOW CAN BE SEEN ON IR AND WATER VAPOR SATELLITE
SPINNING SOUTH INTO NORTHERN MEXICO. A SURFACE LOW IS DEVELOPING
JUST AHEAD OF THE UPPER LEVEL LOW WITH A STATIONARY FRONT DRAPED
FROM NEAR DEL RIO TO NACOGDOCHES TO SHREVEPORT. THIS SURFACE FRONT
IS EXPECTED TO REMAIN NEARLY STATIONARY TONIGHT AND DEWPOINTS
ACROSS THE REGION ARE NOT EXPECTED TO CHANGE MUCH. ISENTROPIC
LIFT IS ALREADY OCCURRING WELL AHEAD OF THE UPPER LEVEL SYSTEM AND
SHOWERS AND THUNDERSTORMS ARE NOW DEVELOPING FROM EAST TEXAS BACK
TO FAR WEST TEXAS. SHOWERS AND ISOLATED THUNDERSTORMS ARE INCREASING
IN AREAL COVERAGE ACROSS NORTH TEXAS...MAINLY SOUTH OF INTERSTATE
20. EXPECT THE RAIN ACTIVITY TO CONTINUE TO INCREASE IN AREAL
COVERAGE ACROSS MUCH OF THE REGION TONIGHT. SHORT TERM MODELS SUCH
AS THE HRRR AND WRF...AND THE 00Z RUN OF THE NAM INDICATE MUCH OF
THE PRECIPITATION OVERNIGHT WILL FALL ALONG AND EAST OF
INTERSTATE 35...THUS INCREASED POPS ACROSS THE NORTHEASTERN
COUNTIES TO CATEGORICAL FOR THE OVERNIGHT HOURS. THE ONLY AREA
THAT LOOKS TO MISS ON MUCH OF THE PRECIPITATION TONIGHT IS THE FAR
NORTHWESTERN COUNTIES AND HAVE MAINTAINED 50 POPS FROM GRAHAM TO
GAINESVILLE. RADAR SIMULATIONS OF THE SHORT TERM MODELS THINK THAT
THE PRECIPITATION OVERNIGHT MAY CLEAR THE REGION TO THE EAST
AROUND DAYBREAK AND THEN THE NEXT ROUND OF RAIN WILL MOVE IN
DURING THE MONDAY MORNING HOURS...SO THERE COULD BE A BREAK IN THE
PRECIPITATION FOR A FEW HOURS MONDAY MORNING.
DUE TO EXTENSIVE AND DENSE CLOUD COVER AND NEARLY STEADY
DEWPOINTS TONIGHT...WARMED OVERNIGHT LOWS A FEW DEGREES IN
SEVERAL LOCATIONS ACROSS THE REGION. TEMPERATURES HAVE BEEN SLOW
TO FALL THIS EVENING AND MAY REMAIN NEARLY STEADY FOR MUCH OF THE
NIGHT BEFORE FALLING AROUND DAYBREAK AS THE FIRST ROUND OF RAIN
MOVES OUT AND SOME LOWER DEWPOINTS EDGE IN FROM THE NORTH.
ONE LAST QUICK NOTE ABOUT THE POTENTIAL FOR A RAIN/SNOW MIX MONDAY
NIGHT AND/OR TUESDAY...THE 00Z NAM CONTINUES TO SHOW ABOVE FREEZING
TEMPERATURES BOTH AT AND ABOVE THE SURFACE. THE 850 MB
TEMPERATURES HAVE WARMED CONSIDERABLY AND IT LOOKS LIKE MUCH OF
THE WRAP AROUND PRECIPITATION WILL OCCUR OUTSIDE OF THE REGION. AFTER
LOOKING AT ALL THE AVAILABLE MODEL DATA...HAVE PUSHED THE
RAIN/SNOW MIX LINE BACK TO JUST THE FAR WESTERN COUNTIES OF THE
CWA. WE ARE STILL NOT EXPECTING ANY IMPACTS DUE TO SNOW NOR ARE WE
EXPECTING ACCUMULATIONS.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 210 PM CST SUN JAN 8 2012/
OLD FRONT IS SLOWLY SINKING SOUTHEAST THIS AFTERNOON AND IS
CURRENTLY ALIGNED ALONG A TEXARKANA...PALESTINE...COLLEGE STATION
LINE WITH TEMPERATURES IN THE LOWER-MID 60S JUST SOUTH OF THE
FRONT TO AROUND 50 DEGREES ACROSS OUR FAR NORTHWEST COUNTIES.
SKIES WERE MOSTLY CLOUDY WITH A FEW SHOWERS NOW SHOWING UP ON
REGIONAL RADAR ACROSS SOUTHEAST TEXAS WITH OUR UPPER LOW NOW
DIVING SOUTHEAST ACROSS EASTERN ARIZONA.
.SHORT TERM/EARLY HALF OF THE WEEK/...
ISENTROPIC ASCENT IN THE 295-300K LAYER WILL CONTINUE TO INCREASE
FROM SOUTH TO NORTH ACROSS THE AREA TONIGHT IN WAA REGIME WELL OUT
AHEAD OF THE UPPER LOW WELL WEST OF NORTH TEXAS. GULF OF MEXICO
WILL BE OPEN FOR BUSINESS IN DEEP SOUTHERLY FETCH OVER THE TOP OF
THE SHALLOW FRONTAL INVERSION THROUGH MONDAY WITH RAIN BECOMING
WIDESPREAD ON MONDAY. LAPSE RATES WILL CONTINUE INCREASING ALOFT
BUT WILL NOT BE OVERLY STEEP WITH A FEW EMBEDDED AREAS OF THUNDER
EXPECTED ALL THE WAY INTO MONDAY NIGHT.
THE UPPER LOW LIFTS EAST ACROSS TEXAS MONDAY NIGHT AND TUESDAY...
TRACKING SOUTH OF I-20. AS THIS OCCURS...LIFT WILL BECOME MORE
DYNAMIC AND IN THE FORM OF DPVA/FRONTOGENETICAL PROCESSES WITH
LARGER SCALE VERTICAL MOTIONS. LOW AND MID LEVEL THICKNESSES WILL
FALL TO LEVELS INDICATING A BRIEF WINDOW FOR A POSSIBLE RAIN/SNOW
MIX LATE MONDAY NIGHT/TUESDAY. FOR NOW...WE WILL ONLY MENTION THIS
POTENTIAL IN THE COLDER AIRMASS FILTERING INTO OUR FAR WESTERN
COUNTIES WHERE HIGHS WILL STRUGGLE TO REACH OVER 40 DEGREES. FEEL
TEMPERATURES FURTHER EAST WILL BE TOO WARM TO SUPPORT SNOW MAKING
IT TO THE SURFACE. HOWEVER...IF FUTURE TEMPERATURES FORECAST COME
IN COLDER...THEN A RAIN/SNOW MIX MAY NEED TO BE CARRIED FURTHER
EAST TOWARD I-35/I-35E CORRIDOR. UPPER LOW WILL DEPART EAST OVER
LOWER MISSISSIPPI VALLEY BY WEDNESDAY MORNING WITH PRECIPITATION
ENDING FROM WEST TO EAST ACROSS NORTH TEXAS.
WEDNESDAY WILL BE QUIET AND SEASONABLE UNDER FLAT UPPER RIDGE
ALOFT.
.LONG TERM/END OF THE WEEK AND NEXT WEEKEND/...
A CHILLY END OF THE WEEK IS EXPECTED AS A STRONG COLD FRONT
CHARGES SOUTHWARD THROUGH THE PLAINS AND INTO TEXAS WEDNESDAY
NIGHT AND THURSDAY. THIS FRONT WILL BE SUPPORTED BY VERY STRONG
HEIGHT FALLS ACROSS THE THE UPPER MIDWEST AND GREAT LAKES WITH AN
UPPER RIDGE STEEPENING ACROSS THE U.S WEST COAST. WE HAVE UNDERCUT
MOS HIGHS THURSDAY/FRIDAY.
MEDIUM RANGE MODELS NOW AGREEING TO KEEP BULK OF EASTERN PACIFIC
ENERGY CUT OFF NEAR THE CALIFORNIA COASTLINE WITH CONFLUENT UPPER
FLOW ACROSS CENTRAL TEXAS. THIS PATTERN GENERALLY MEANS DRY AND
COLD WEATHER. THE CUT OFF LOW WILL EVENTUALLY GET PUSHED EAST
THROUGH THE DESERT SOUTHWEST NEXT WEEKEND BY A KICKER SYSTEM IN
THE PACIFIC NORTHWEST. TEMPERATURES WILL WARM UP AHEAD OF THIS
SYSTEM AS COLD SURFACE HIGH SHIFTS OVER THE GULF COAST STATES WITH
SWLY LOW LEVEL FLOW RETURNING. THOUGH LOW RAIN CHANCES APPEAR
POSSIBLE NEXT SUNDAY/MONDAY...HAVE LEFT THE FORECAST DRY UNTIL
MOISTURE AND TIMING OF BETTER LIFT CAN BE RESOLVED.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 44 48 40 45 36 / 90 100 100 60 10
WACO, TX 49 50 37 49 34 / 100 100 90 30 10
PARIS, TX 45 51 46 49 38 / 80 80 90 80 30
DENTON, TX 42 48 39 45 34 / 80 90 100 60 10
MCKINNEY, TX 43 49 42 45 35 / 80 90 100 70 20
DALLAS, TX 45 50 42 45 37 / 90 100 100 60 20
TERRELL, TX 45 52 43 48 36 / 90 100 100 60 20
CORSICANA, TX 50 57 41 48 36 / 100 100 100 50 20
TEMPLE, TX 50 50 39 52 34 / 100 100 80 20 5
MINERAL WELLS, TX 40 45 36 43 32 / 70 90 90 40 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
952 PM CST SUN JAN 8 2012
.UPDATE...
OVERALL THE CURRENT FORECAST WAS ON TRACK BUT DID MAKE SOME MINOR
ADJUSTMENTS TO POPS AND TO WARM OVERNIGHT LOWS ACROSS THE REGION.
THE UPPER LEVEL LOW CAN BE SEEN ON IR AND WATER VAPOR SATELLITE
SPINNING SOUTH INTO NORTHERN MEXICO. A SURFACE LOW IS DEVELOPING
JUST AHEAD OF THE UPPER LEVEL LOW WITH A STATIONARY FRONT DRAPED
FROM NEAR DEL RIO TO NACOGDOCHES TO SHREVEPORT. THIS SURFACE FRONT
IS EXPECTED TO REMAIN NEARLY STATIONARY TONIGHT AND DEWPOINTS
ACROSS THE REGION ARE NOT EXPECTED TO CHANGE MUCH. ISENTROPIC
LIFT IS ALREADY OCCURRING WELL AHEAD OF THE UPPER LEVEL SYSTEM AND
SHOWERS AND THUNDERSTORMS ARE NOW DEVELOPING FROM EAST TEXAS BACK
TO FAR WEST TEXAS. SHOWERS AND ISOLATED THUNDERSTORMS ARE INCREASING
IN AREAL COVERAGE ACROSS NORTH TEXAS...MAINLY SOUTH OF INTERSTATE
20. EXPECT THE RAIN ACTIVITY TO CONTINUE TO INCREASE IN AREAL
COVERAGE ACROSS MUCH OF THE REGION TONIGHT. SHORT TERM MODELS SUCH
AS THE HRRR AND WRF...AND THE 00Z RUN OF THE NAM INDICATE MUCH OF
THE PRECIPITATION OVERNIGHT WILL FALL ALONG AND EAST OF
INTERSTATE 35...THUS INCREASED POPS ACROSS THE NORTHEASTERN
COUNTIES TO CATEGORICAL FOR THE OVERNIGHT HOURS. THE ONLY AREA
THAT LOOKS TO MISS ON MUCH OF THE PRECIPITATION TONIGHT IS THE FAR
NORTHWESTERN COUNTIES AND HAVE MAINTAINED 50 POPS FROM GRAHAM TO
GAINESVILLE. RADAR SIMULATIONS OF THE SHORT TERM MODELS THINK THAT
THE PRECIPITATION OVERNIGHT MAY CLEAR THE REGION TO THE EAST
AROUND DAYBREAK AND THEN THE NEXT ROUND OF RAIN WILL MOVE IN
DURING THE MONDAY MORNING HOURS...SO THERE COULD BE A BREAK IN THE
PRECIPITATION FOR A FEW HOURS MONDAY MORNING.
DUE TO EXTENSIVE AND DENSE CLOUD COVER AND NEARLY STEADY
DEWPOINTS TONIGHT...WARMED OVERNIGHT LOWS A FEW DEGREES IN
SEVERAL LOCATIONS ACROSS THE REGION. TEMPERATURES HAVE BEEN SLOW
TO FALL THIS EVENING AND MAY REMAIN NEARLY STEADY FOR MUCH OF THE
NIGHT BEFORE FALLING AROUND DAYBREAK AS THE FIRST ROUND OF RAIN
MOVES OUT AND SOME LOWER DEWPOINTS EDGE IN FROM THE NORTH.
ONE LAST QUICK NOTE ABOUT THE POTENTIAL FOR A RAIN/SNOW MIX MONDAY
NIGHT AND/OR TUESDAY...THE 00Z NAM CONTINUES TO SHOW ABOVE FREEZING
TEMPERATURES BOTH AT AND ABOVE THE SURFACE. THE 850 MB
TEMPERATURES HAVE WARMED CONSIDERABLY AND IT LOOKS LIKE MUCH OF
THE WRAP AROUND PRECIPITATION WILL OCCUR OUTSIDE OF THE REGION. AFTER
LOOKING AT ALL THE AVAILABLE MODEL DATA...HAVE PUSHED THE
RAIN/SNOW MIX LINE BACK TO JUST THE FAR WESTERN COUNTIES OF THE
CWA. WE ARE STILL NOT EXPECTING ANY IMPACTS DUE TO SNOW NOR ARE WE
EXPECTING ACCUMULATIONS.
82/JLD
&&
.AVIATION...
MVFR CIGS OVER THE METROPLEX ARE BEGINNING TO BREAK UP AND WE
SHOULD SEE A PERIOD OF VFR FOR THE NEXT FEW HOURS. RAIN WILL
DEVELOP OVER THE REGION FROM THE SOUTH THIS EVENING...AND AS IT
REACHES THE TAF SITES CIGS WILL FALL AS LOW LEVELS SATURATE. WILL
HAVE MVFR FOR METROPLEX SITES STARTING AT 4Z...AND IFR PREVAILING
AFTER 7Z. SHOWERS AND IFR CIGS WILL PREVAIL AT ALL SITES THROUGH
TOMORROW AFTERNOON...WITH A POSSIBLE BREAK/END IN THE RAIN BY
SUNSET TOMORROW. VSBY MAY BECOME MORE RESTRICTED DURING PERIODS OF
HEAVIER RAIN...BUT WILL PREVAIL 5SM. MOST OF THE ACTIVITY SHOULD
BE SHOWERS...BUT ISOLATED THUNDERSTORMS ARE POSSIBLE. DUE TO THE
ISOLATED NATURE OF STORMS WILL HOLD OFF ON FORECASTING THEM
RIGHT NOW...BUT THE BEST TIME FRAME FOR THUNDER AT TAF SITES IS
PROBABLY BETWEEN 8-12Z.
FOR WACO...MVFR CIGS ARE ALREADY PREVAILING AND EXPECT RAIN TO
ARRIVE A COUPLE OF HOURS SOONER. IFR SHOULD START AROUND 6Z.
THREAT FOR STORMS A LITTLE HIGHER IN WACO THROUGH THE NEXT 12-18
HOURS...BUT NOT HIGH ENOUGH TO FORECAST THEM JUST YET. WILL AMEND
TAF FOR THUNDER WHEN IT BECOME MORE APPARENT.
TR.92
&&
.PREV DISCUSSION... /ISSUED 210 PM CST SUN JAN 8 2012/
OLD FRONT IS SLOWLY SINKING SOUTHEAST THIS AFTERNOON AND IS
CURRENTLY ALIGNED ALONG A TEXARKANA...PALESTINE...COLLEGE STATION
LINE WITH TEMPERATURES IN THE LOWER-MID 60S JUST SOUTH OF THE
FRONT TO AROUND 50 DEGREES ACROSS OUR FAR NORTHWEST COUNTIES.
SKIES WERE MOSTLY CLOUDY WITH A FEW SHOWERS NOW SHOWING UP ON
REGIONAL RADAR ACROSS SOUTHEAST TEXAS WITH OUR UPPER LOW NOW
DIVING SOUTHEAST ACROSS EASTERN ARIZONA.
.SHORT TERM/EARLY HALF OF THE WEEK/...
ISENTROPIC ASCENT IN THE 295-300K LAYER WILL CONTINUE TO INCREASE
FROM SOUTH TO NORTH ACROSS THE AREA TONIGHT IN WAA REGIME WELL OUT
AHEAD OF THE UPPER LOW WELL WEST OF NORTH TEXAS. GULF OF MEXICO
WILL BE OPEN FOR BUSINESS IN DEEP SOUTHERLY FETCH OVER THE TOP OF
THE SHALLOW FRONTAL INVERSION THROUGH MONDAY WITH RAIN BECOMING
WIDESPREAD ON MONDAY. LAPSE RATES WILL CONTINUE INCREASING ALOFT
BUT WILL NOT BE OVERLY STEEP WITH A FEW EMBEDDED AREAS OF THUNDER
EXPECTED ALL THE WAY INTO MONDAY NIGHT.
THE UPPER LOW LIFTS EAST ACROSS TEXAS MONDAY NIGHT AND TUESDAY...
TRACKING SOUTH OF I-20. AS THIS OCCURS...LIFT WILL BECOME MORE
DYNAMIC AND IN THE FORM OF DPVA/FRONTOGENETICAL PROCESSES WITH
LARGER SCALE VERTICAL MOTIONS. LOW AND MID LEVEL THICKNESSES WILL
FALL TO LEVELS INDICATING A BRIEF WINDOW FOR A POSSIBLE RAIN/SNOW
MIX LATE MONDAY NIGHT/TUESDAY. FOR NOW...WE WILL ONLY MENTION THIS
POTENTIAL IN THE COLDER AIRMASS FILTERING INTO OUR FAR WESTERN
COUNTIES WHERE HIGHS WILL STRUGGLE TO REACH OVER 40 DEGREES. FEEL
TEMPERATURES FURTHER EAST WILL BE TOO WARM TO SUPPORT SNOW MAKING
IT TO THE SURFACE. HOWEVER...IF FUTURE TEMPERATURES FORECAST COME
IN COLDER...THEN A RAIN/SNOW MIX MAY NEED TO BE CARRIED FURTHER
EAST TOWARD I-35/I-35E CORRIDOR. UPPER LOW WILL DEPART EAST OVER
LOWER MISSISSIPPI VALLEY BY WEDNESDAY MORNING WITH PRECIPITATION
ENDING FROM WEST TO EAST ACROSS NORTH TEXAS.
WEDNESDAY WILL BE QUIET AND SEASONABLE UNDER FLAT UPPER RIDGE
ALOFT.
&&
.SHORT TERM/EARLY HALF OF THE WEEK/...
ISENTROPIC ASCENT IN THE 295-300K LAYER WILL CONTINUE TO INCREASE
FROM SOUTH TO NORTH ACROSS THE AREA TONIGHT IN WAA REGIME WELL OUT
AHEAD OF THE UPPER LOW WELL WEST OF NORTH TEXAS. GULF OF MEXICO
WILL BE OPEN FOR BUSINESS IN DEEP SOUTHERLY FETCH OVER THE TOP OF
THE SHALLOW FRONTAL INVERSION THROUGH MONDAY WITH RAIN BECOMING
WIDESPREAD ON MONDAY. LAPSE RATES WILL CONTINUE INCREASING ALOFT
BUT WILL NOT BE OVERLY STEEP WITH A FEW EMBEDDED AREAS OF THUNDER
EXPECTED ALL THE WAY INTO MONDAY NIGHT.
THE UPPER LOW LIFTS EAST ACROSS TEXAS MONDAY NIGHT AND TUESDAY...
TRACKING SOUTH OF I-20. AS THIS OCCURS...LIFT WILL BECOME MORE
DYNAMIC AND IN THE FORM OF DPVA/FRONTOGENETICAL PROCESSES WITH
LARGER SCALE VERTICAL MOTIONS. LOW AND MID LEVEL THICKNESSES WILL
FALL TO LEVELS INDICATING A BRIEF WINDOW FOR A POSSIBLE RAIN/SNOW
MIX LATE MONDAY NIGHT/TUESDAY. FOR NOW...WE WILL ONLY MENTION THIS
POTENTIAL IN THE COLDER AIRMASS FILTERING INTO OUR FAR WESTERN
COUNTIES WHERE HIGHS WILL STRUGGLE TO REACH OVER 40 DEGREES. FEEL
TEMPERATURES FURTHER EAST WILL BE TOO WARM TO SUPPORT SNOW MAKING
IT TO THE SURFACE. HOWEVER...IF FUTURE TEMPERATURES FORECAST COME
IN COLDER...THEN A RAIN/SNOW MIX MAY NEED TO BE CARRIED FURTHER
EAST TOWARD I-35/I-35E CORRIDOR. UPPER LOW WILL DEPART EAST OVER
LOWER MISSISSIPPI VALLEY BY WEDNESDAY MORNING WITH PRECIPITATION
ENDING FROM WEST TO EAST ACROSS NORTH TEXAS.
WEDNESDAY WILL BE QUIET AND SEASONABLE UNDER FLAT UPPER RIDGE
ALOFT.
&&
.LONG TERM/END OF THE WEEK AND NEXT WEEKEND/...
A CHILLY END OF THE WEEK IS EXPECTED AS A STRONG COLD FRONT
CHARGES SOUTHWARD THROUGH THE PLAINS AND INTO TEXAS WEDNESDAY
NIGHT AND THURSDAY. THIS FRONT WILL BE SUPPORTED BY VERY STRONG
HEIGHT FALLS ACROSS THE THE UPPER MIDWEST AND GREAT LAKES WITH AN
UPPER RIDGE STEEPENING ACROSS THE U.S WEST COAST. WE HAVE UNDERCUT
MOS HIGHS THURSDAY/FRIDAY.
MEDIUM RANGE MODELS NOW AGREEING TO KEEP BULK OF EASTERN PACIFIC
ENERGY CUT OFF NEAR THE CALIFORNIA COASTLINE WITH CONFLUENT UPPER
FLOW ACROSS CENTRAL TEXAS. THIS PATTERN GENERALLY MEANS DRY AND
COLD WEATHER. THE CUT OFF LOW WILL EVENTUALLY GET PUSHED EAST
THROUGH THE DESERT SOUTHWEST NEXT WEEKEND BY A KICKER SYSTEM IN
THE PACIFIC NORTHWEST. TEMPERATURES WILL WARM UP AHEAD OF THIS
SYSTEM AS COLD SURFACE HIGH SHIFTS OVER THE GULF COAST STATES WITH
SWLY LOW LEVEL FLOW RETURNING. THOUGH LOW RAIN CHANCES APPEAR
POSSIBLE NEXT SUNDAY/MONDAY...HAVE LEFT THE FORECAST DRY UNTIL
MOISTURE AND TIMING OF BETTER LIFT CAN BE RESOLVED.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 44 48 40 45 36 / 90 100 100 60 10
WACO, TX 49 50 37 49 34 / 100 100 90 30 10
PARIS, TX 45 51 46 49 38 / 80 80 90 80 30
DENTON, TX 42 48 39 45 34 / 80 90 100 60 10
MCKINNEY, TX 43 49 42 45 35 / 80 90 100 70 20
DALLAS, TX 45 50 42 45 37 / 90 100 100 60 20
TERRELL, TX 45 52 43 48 36 / 90 100 100 60 20
CORSICANA, TX 50 57 41 48 36 / 100 100 100 50 20
TEMPLE, TX 50 50 39 52 34 / 100 100 80 20 5
MINERAL WELLS, TX 40 45 36 43 32 / 70 90 90 40 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
92/82
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
321 PM CST SAT JAN 7 2012
.DISCUSSION...
THE WEAK COLD FRONT HAS SLOWED DRAMATICALLY ACROSS EAST TEXAS AND
OUR THE SOUTHEAST COUNTIES TODAY WITH MINIMAL PRESSURE RISES BEHIND
THE FRONT. A WEAK INVERTED TROUGH IN THE 925-850MB LAYER HAS BEEN
NEARLY STATIONARY AS WELL OVER THE I-35 CORRIDOR/RED RIVER VALLEY
ALL DAY. THIS HAS RESULTED IN WEAK ISENTROPIC ASCENT THAT IS
HOLDING STRATUS OVER NORTHERN COUNTIES AND MAKING THE FORECAST
DIFFICULT WITH REGARD TO CLOUD COVER AND TEMPERATURES. MEANWHILE
AN UPPER DISTURBANCE CONTINUES TO INTENSIFY AND DEEPEN OVER THE
CENTRAL ROCKIES.
THE HRRR/WRF AND RUC BAK40 SOUNDINGS ALL INDICATE AT LEAST SOME
POTENTIAL FOR FOG DEVELOPING OVERNIGHT WITH WINDS BECOMING LIGHT
AND A TIGHT MOISTURE GRADIENT UP THROUGH THE BOUNDARY LAYER
THROUGH MIDDAY SUNDAY. WE ARE INSERTING PATCHY FOG EAST OF A
BOWIE...MINERAL WELLS...KILLEEN LINE WITH MORE COVERAGE OF LIGHT
FOG ACROSS THE NORTHEAST COUNTIES. TOO DIFFICULT TO ASCERTAIN IF
ANY FOG WILL BE DENSE AT THIS TIME. ANY FOG SHOULD DISSIPATE BY
AFTERNOON AS NORTH WINDS MIX TO AROUND 10 MPH OR SLIGHTLY HIGHER
THOUGH SOUTHEAST COUNTIES WILL HAVE LIGHTER NORTHEAST WINDS.
ISENTROPIC LIFT BEGINS OVER THE STALLED FRONTAL BOUNDARY SUNDAY
AFTERNOON IN DEVELOPING WAA REGIME ACROSS OUR SOUTHEAST COUNTIES.
THE ROCKIES DISTURBANCE WILL DEEPEN AND CLOSE OFF OVER AZ/NM AS
WELL. LIGHT RAIN SHOULD SLOWLY DEVELOP ACROSS THE SOUTHEAST BY
AFTERNOON...THEN OVERSPREAD NORTH TEXAS SUNDAY NIGHT AND MONDAY
AS ISENTROPIC ASCENT INCREASES WITH PLENTY OF FETCH FROM THE GULF
OF MEXICO. A GOOD STEADY RAIN IS EXPECTED INTO MONDAY EVENING.
1-2 INCHES OF BENEFICIAL RAINFALL WILL LIKELY OCCUR OVER THE FULL
DURATION WITH ISOLATED AMOUNTS IN EXCESS OF 3 INCHES POSSIBLE
ACROSS FAR SOUTHEASTERN AREAS. HAVE MAINTAINED ISOLATED/EMBEDDED
THUNDERSTORMS WITH LARGE-SCALE LIFT INTENSIFYING AND LAPSE RATES
ALOFT INCREASING TO NEAR 7 DEG/C.
THE UPPER LOW SLIDES OVER WEST TX BY MONDAY EVENING...THEN MODELS
CONTINUE TO DIVERGE ON ACTUAL STRENGTH/TRACK MONDAY NIGHT AND TUESDAY.
WILL USE A MEAN OF THE TRACKS WITH COLDEST AIR ALOFT TRACKING
ACROSS AREAS JUST NORTHWEST OF THE DFW METROPLEX. WITH THIS IN
MIND...A RAIN/SNOW SHOWER MIX COULD OCCUR WITH DYNAMIC COOLING AND
COLDER SURFACE TEMPERATURES ACROSS THE HIGHER TERRAIN OF THE
WESTERN COUNTIES. BOTH SURFACE AND GROUND TEMPERATURES WILL
REMAIN WELL ABOVE FREEZING BUT PROFILES ALOFT MAY SUPPORT SOME
SNOW MIXING IN WITH THE RAIN. IF ANY MINOR ACCUMULATIONS WERE TO
OCCUR...IT WOULD BE MINOR AND BRIEF ON ELEVATED SURFACES OR
GRASSY AREAS. DETAILS REMAIN FUZZY WE DO NOT EXPECT A MAJOR
WINTER EVENT WITH THIS SYSTEM. A DRY NOSE DOES APPEAR TO ARRIVE
TUESDAY FROM THE SOUTHWEST AND GET INGESTED INTO THE SYSTEM WITH
PRECIPITATION CHANCES LOWERING QUICKLY FROM SOUTH TO NORTH AS THE
UPPER LOW LIFTS TOWARD THE OZARKS AND MISSISSIPPI VALLEY BY
TUESDAY NIGHT.
A STRONGER COLD FRONT TAPPING AIR FROM ALASKA AND WESTERN CANADA
ARRIVES THURSDAY/FRIDAY A STEEP UPPER RIDGE ACROSS THE WESTERN
STATES AND A DEEP TROUGH OVER THE GREAT LAKES AND MISSISSIPPI
VALLEY. MEANWHILE...THE GFS AND ECMWF AS SWAPPED SOLUTIONS
REGARDING A POSSIBLE SOUTHERN PIECE OF ENERGY MOVING ACROSS RIGHT
AROUND THAT TIME FRAME. FOR NOW...WE ARE MAINTAINING A DRY...BRISK
AND COLD FORECAST AND UNDERCUTTING MOS TEMPERATURES BY A GOOD 5
DEGREES OR MORE PER PATTERN RECOGNITION. IT IS POSSIBLE THAT HIGHS
MAY NEED TO BE LOWERED IN UPCOMING FORECASTS IF IT BECOMES EVIDENT
THAT THIS IS TRUE ARCTIC AIR ORIGIN.
WE WILL CONTINUE TO FINE TUNE THE LATE WEEK FORECAST ONCE WE GET
PAST OUR FIRST SYSTEM FOR THE EARLY PART OF THE WEEK.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 43 57 44 46 40 / 5 10 80 100 70
WACO, TX 39 63 46 49 39 / 10 20 90 100 50
PARIS, TX 45 56 43 51 40 / 10 20 70 100 90
DENTON, TX 36 55 39 44 38 / 10 10 70 90 80
MCKINNEY, TX 38 57 41 47 39 / 10 10 70 100 80
DALLAS, TX 44 58 45 47 41 / 5 10 80 100 70
TERRELL, TX 42 58 46 50 40 / 10 20 80 100 80
CORSICANA, TX 42 61 48 53 41 / 10 20 90 100 70
TEMPLE, TX 40 65 46 49 39 / 10 20 90 100 40
MINERAL WELLS, TX 34 57 37 42 36 / 5 10 70 90 60
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/05
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1200 PM CST SAT JAN 7 2012
.AVIATION...
/18Z TAFS/
CONCERNS...CIGS EARLY...POTENTIAL FOR CIGS/VSBY ISSUES SUNDAY AM.
SURFACE LOW NEAR PARIS IS MAKING MINIMAL PROGRESS EAST...KEEPING
WRAP-AROUND CIGS IN PLACE OVER METRO TAF SITES. DESPITE COOL
BOUNDARY LAYER...STILL EXPECT CIGS BENEATH FRONTAL INVERSION TO
GRADUALLY LIFT ABOVE 2KFT AS POSTFRONTAL LAYER DEEPENS...
DISSIPATING MID-AFTERNOON.
WITH A WEAK GRADIENT...LOW MAY RETREAT WEST TONIGHT. AT THIS
POINT...EXPECT MAIN INFLUX OF LOW-LEVEL MOISTURE WILL BE EAST OF
TAF SITES. WILL HAVE TO WATCH MOTION CAREFULLY...AS CIGS MAY NOT
BE FAR AWAY SUNDAY MORNING. WITH LIGHT WINDS...SOME REDUCTIONS IN
VSBY MAY RESULT. FOR NOW...WILL FORGO INCLUDING EITHER CIGS OR
VSBY ISSUES...BUT WILL NEED TO REASSESS WITH FUTURE ISSUANCES.
ISENTROPIC LIFT WILL ENSUE SUNDAY IN ADVANCE OF APPROACHING
SYSTEM. HAVE INTRODUCED BKN060 OVC150 INTO TAFACT AND EXTENDED
PORTION OF TAFDFW. AGREE WITH CWSU ZFW THAT ANY LIGHT RAIN SHOULD
OCCUR BEYOND CURRENT TAF PERIODS.
25
&&
.UPDATE...
ISENTROPIC LIFT ON THE 285K-290K ISENTROPIC RUC SURFACES SHOW
THAT BOUNDARY LAYER STRATUS 012-025 KFT WILL LINGER ACROSS PARTS
OF NORTHEASTERN PARTS OF NORTH TEXAS WILL PREVAIL THROUGH AT LEAST
EARLY-MID AFTERNOON PER BOUNDARY LAYER MOISTURE FORECASTS. MODELS
ARE STRUGGLING ON TIMING OF DEPARTURE TO THE EAST OF THE CLOUDS
AND THE FRONTAL PUSH THIS AFTERNOON. PRESSURE RISES BEHIND THE
COLD FRONT ARE ONLY ON THE ORDER OF 1-2MB/3 HR.
HAVE ALSO INCREASED NORTHWEST WINDS WITH SOME GUSTINESS THROUGH
EARLY AFTERNOON PER BOUNDARY LAYER WINDS ON LOCAL PROFILERS LIKELY
TO MIX BY MIDDAY. THE CONTINUED CAA AND LINGERING STRATUS ACROSS
THE NORTHEAST HALF OF NORTH TEXAS HAS LED US TO LOWER HIGHS ACROSS
THESE COUNTIES INTO THE LOWER AND MID 50S...INCLUDING THE DFW
METROPLEX. THIS MAY BE OPTIMISTIC IF CLEARING THIS AFTERNOON IS
SLOWER THAN ANTICIPATED.
05
&&
.PREV DISCUSSION... /ISSUED 358 AM CST SAT JAN 7 2012/
SOME CHANGES WILL TAKE PLACE IN THE WEATHER PATTERN OVER THE NEXT
FEW DAYS WHICH WILL RESULT IN SOME MUCH NEEDED RAIN FOR THE
REGION. INITIALLY...A COLD FRONT WILL MOVE ACROSS NORTH TEXAS
TODAY AND BRING COOLER AND DRIER AIR. TEMPERATURES TODAY WILL BE
ABOUT 10 TO 15 DEGREES COOLER THAN FRIDAY WITH HIGHS MAINLY IN THE
UPPER 50S TO LOWER 60S....EXCEPT FOR A FEW READINGS IN THE UPPER
60S TO LOWER 70S IN THE SOUTHERN ZONES. MOISTURE WILL BE ON THE
INCREASE ACROSS TEXAS TONIGHT AND SUNDAY AS A LOW PRESSURE SYSTEM
DEEPENS NEAR THE FOUR CORNERS REGION. THIS WILL RESULT IN A CLOUDY
DAY SUNDAY WITH A FEW SHOWERS IN THE SOUTH...THEN INCREASING RAIN
CHANCES SUNDAY NIGHT AND MONDAY AS LARGE SCALE FORCING INTERACTS
WITH THE MOISTURE. THE MODELS ARE FINALLY STARTING TO AGREE MORE
ON THE TRACK AND TIMING OF THIS SYSTEM. IT APPEARS THAT ALL OF
NORTH TEXAS WILL SEE APPRECIABLE RAINFALL...ESPECIALLY MONDAY AND
MONDAY NIGHT WITH RAIN ENDING FROM WEST TO EAST ON TUESDAY. THERE
IS EVEN A CHANCE OF A RAIN/SNOW MIX IN THE NORTHWEST ZONES
OVERNIGHT MONDAY/TUESDAY MORNING AS THE CORE OF THE UPPER LOW TRACKS
OVER THE REGION. EVEN IF THE NAM SOLUTION...WHICH IS THE
COLDEST...VERIFIES...LOW LEVEL TEMPERATURES SHOULD STILL BE TOO
WARM FOR ANY TYPE OF SNOW ACCUMULATION. SO FOR NOW WILL JUST
MENTION THE POTENTIAL FOR A MIX AND ALLOW LATER SHIFTS TO REFINE
AND ADJUST. ALL PRECIPITATION SHOULD END ACROSS NORTH TEXAS
TUESDAY NIGHT BUT RAINFALL TOTALS SHOULD AVERAGE BETWEEN 1 AND 2
INCHES IN MOST LOCATIONS WITH EVEN SOME HIGHER AMOUNTS POSSIBLE IN
THE EAST. SINCE RAINFALL SHOULD OCCUR OVER A 24 TO 36 HOUR TIME
SPAN...THE TREAT OF FLOODING SHOULD BE LOW. WILL MENTION ISOLATED
THUNDER WITH THIS EVENT SINCE MID LEVEL LAPSE RATES SHOULD BE
SUFFICIENT TO SUPPORT SOME ELEVATED CORES.
MID WEEK THROUGH THE WEEKEND SHOULD BE DRY AND SEASONABLY COOL
WITH WEST TO SOUTHWEST FLOW ALOFT AND DRY AIR AT THE SURFACE. IT
DOES APPEAR THAT ANOTHER PIECE OF ENERGY WILL DEVELOP IN THE
SOUTHERN JET STREAM BY THE WEEKEND AND MAY BRING RAIN CHANCES BACK
TO NORTH TEXAS BY NEXT SATURDAY OR SUNDAY.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 56 43 64 43 48 / 5 5 10 70 70
WACO, TX 62 43 63 45 50 / 5 5 20 70 70
PARIS, TX 56 45 62 42 50 / 5 5 10 70 60
DENTON, TX 55 36 61 38 47 / 5 5 10 70 60
MCKINNEY, TX 54 38 63 40 48 / 5 5 10 60 60
DALLAS, TX 56 44 63 44 48 / 5 5 10 70 70
TERRELL, TX 57 42 62 45 50 / 10 5 10 60 70
CORSICANA, TX 62 45 66 47 52 / 10 5 20 60 70
TEMPLE, TX 65 45 67 45 48 / 5 5 20 80 70
MINERAL WELLS, TX 58 34 60 36 45 / 5 5 10 70 70
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25/05
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
934 AM CST SAT JAN 7 2012
.UPDATE...
ISENTROPIC LIFT ON THE 285K-290K ISENTROPIC RUC SURFACES SHOW
THAT BOUNDARY LAYER STRATUS 012-025 KFT WILL LINGER ACROSS PARTS
OF NORTHEASTERN PARTS OF NORTH TEXAS WILL PREVAIL THROUGH AT LEAST
EARLY-MID AFTERNOON PER BOUNDARY LAYER MOISTURE FORECASTS. MODELS
ARE STRUGGLING ON TIMING OF DEPARTURE TO THE EAST OF THE CLOUDS
AND THE FRONTAL PUSH THIS AFTERNOON. PRESSURE RISES BEHIND THE
COLD FRONT ARE ONLY ON THE ORDER OF 1-2MB/3 HR.
HAVE ALSO INCREASED NORTHWEST WINDS WITH SOME GUSTINESS THROUGH
EARLY AFTERNOON PER BOUNDARY LAYER WINDS ON LOCAL PROFILERS LIKELY
TO MIX BY MIDDAY. THE CONTINUED CAA AND LINGERING STRATUS ACROSS
THE NORTHEAST HALF OF NORTH TEXAS HAS LED US TO LOWER HIGHS ACROSS
THESE COUNTIES INTO THE LOWER AND MID 50S...INCLUDING THE DFW
METROPLEX. THIS MAY BE OPTIMISTIC IF CLEARING THIS AFTERNOON IS
SLOWER THAN ANTICIPATED.
05
&&
.AVIATION...
A COLD FRONT STRETCHED ROUGHLY ALONG THE INTERSTATE 35/35E
CORRIDOR EARLY THIS MORNING. THE FRONT HAD RECENTLY CROSSED ALL AREA
TERMINALS WHERE WINDS HAD BECOME WEST DURING THE PAST HOUR OR SO.
SURFACE WINDS SHOULD CONTINUE TO VEER THROUGH THE MORNING...BECOMING
NORTH-NORTHWEST AROUND 10 KT BY 16Z. IFR STRATUS IS THICKENING
IMMEDIATELY AHEAD OF THE BOUNDARY BUT SHOULD REMAIN EAST OF TAF
SITES. LINGERING SHALLOW MOISTURE MAY ALLOW SOME SCATTERED CLOUDS
TO OCCASIONALLY FORM THROUGH 14Z...BUT DRIER WNW FLOW AND WEAK
ISENTROPIC DOWN-GLIDE SHOULD KEEP LOW CLOUD DEVELOPMENT TO A
MINIMUM NORTHWEST OF THE BOUNDARY. WINDS WILL DIE DOWN AFTER
SUNSET AND SHOULD REMAIN FAIRLY LIGHT THROUGH SUNDAY MORNING.
OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH THIS FORECAST
PERIOD.
30
&&
.PREV DISCUSSION... /ISSUED 358 AM CST SAT JAN 7 2012/
SOME CHANGES WILL TAKE PLACE IN THE WEATHER PATTERN OVER THE NEXT
FEW DAYS WHICH WILL RESULT IN SOME MUCH NEEDED RAIN FOR THE
REGION. INITIALLY...A COLD FRONT WILL MOVE ACROSS NORTH TEXAS
TODAY AND BRING COOLER AND DRIER AIR. TEMPERATURES TODAY WILL BE
ABOUT 10 TO 15 DEGREES COOLER THAN FRIDAY WITH HIGHS MAINLY IN THE
UPPER 50S TO LOWER 60S....EXCEPT FOR A FEW READINGS IN THE UPPER
60S TO LOWER 70S IN THE SOUTHERN ZONES. MOISTURE WILL BE ON THE
INCREASE ACROSS TEXAS TONIGHT AND SUNDAY AS A LOW PRESSURE SYSTEM
DEEPENS NEAR THE FOUR CORNERS REGION. THIS WILL RESULT IN A CLOUDY
DAY SUNDAY WITH A FEW SHOWERS IN THE SOUTH...THEN INCREASING RAIN
CHANCES SUNDAY NIGHT AND MONDAY AS LARGE SCALE FORCING INTERACTS
WITH THE MOISTURE. THE MODELS ARE FINALLY STARTING TO AGREE MORE
ON THE TRACK AND TIMING OF THIS SYSTEM. IT APPEARS THAT ALL OF
NORTH TEXAS WILL SEE APPRECIABLE RAINFALL...ESPECIALLY MONDAY AND
MONDAY NIGHT WITH RAIN ENDING FROM WEST TO EAST ON TUESDAY. THERE
IS EVEN A CHANCE OF A RAIN/SNOW MIX IN THE NORTHWEST ZONES
OVERNIGHT MONDAY/TUESDAY MORNING AS THE CORE OF THE UPPER LOW TRACKS
OVER THE REGION. EVEN IF THE NAM SOLUTION...WHICH IS THE
COLDEST...VERIFIES...LOW LEVEL TEMPERATURES SHOULD STILL BE TOO
WARM FOR ANY TYPE OF SNOW ACCUMULATION. SO FOR NOW WILL JUST
MENTION THE POTENTIAL FOR A MIX AND ALLOW LATER SHIFTS TO REFINE
AND ADJUST. ALL PRECIPITATION SHOULD END ACROSS NORTH TEXAS
TUESDAY NIGHT BUT RAINFALL TOTALS SHOULD AVERAGE BETWEEN 1 AND 2
INCHES IN MOST LOCATIONS WITH EVEN SOME HIGHER AMOUNTS POSSIBLE IN
THE EAST. SINCE RAINFALL SHOULD OCCUR OVER A 24 TO 36 HOUR TIME
SPAN...THE TREAT OF FLOODING SHOULD BE LOW. WILL MENTION ISOLATED
THUNDER WITH THIS EVENT SINCE MID LEVEL LAPSE RATES SHOULD BE
SUFFICIENT TO SUPPORT SOME ELEVATED CORES.
MID WEEK THROUGH THE WEEKEND SHOULD BE DRY AND SEASONABLY COOL
WITH WEST TO SOUTHWEST FLOW ALOFT AND DRY AIR AT THE SURFACE. IT
DOES APPEAR THAT ANOTHER PIECE OF ENERGY WILL DEVELOP IN THE
SOUTHERN JET STREAM BY THE WEEKEND AND MAY BRING RAIN CHANCES BACK
TO NORTH TEXAS BY NEXT SATURDAY OR SUNDAY.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 56 43 64 43 48 / 5 5 10 70 70
WACO, TX 62 43 63 45 50 / 5 5 20 70 70
PARIS, TX 56 45 62 42 50 / 5 5 10 70 60
DENTON, TX 55 36 61 38 47 / 5 5 10 70 60
MCKINNEY, TX 54 38 63 40 48 / 5 5 10 60 60
DALLAS, TX 56 44 63 44 48 / 5 5 10 70 70
TERRELL, TX 57 42 62 45 50 / 10 5 10 60 70
CORSICANA, TX 62 45 66 47 52 / 10 5 20 60 70
TEMPLE, TX 65 45 67 45 48 / 5 5 20 80 70
MINERAL WELLS, TX 58 34 60 36 45 / 5 5 10 70 70
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
30/05
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1125 AM CST SAT JAN 7 2012
.UPDATE...AREA OF LOW LEVEL CLOUDS MOVING THROUGH NORTHEASTERN
PORTIONS OF THE AREA. EXPECT THIS BAND OF CLOUDS TO CONTINUE
SOUTHEAST AND CLIP THE SOUTHEASTERN COUNTIES EARLY THIS AFTERNOON.
DRY AIR ERODING CLOUDS IMMEDIATELY UPSTREAM OF THE AREA...WITH
ANOTHER DECK OF CLOUDS OVER EAST CENTRAL MINNESOTA. THIS DECK MAY
ERODE AS WELL AS IT SHIFTS SOUTHEAST...SO FOR NOW WILL TREND TO
MORE SUN THAN CLOUDS THIS AFTERNOON IN THE WEST AND SOUTH.
TEMPERATURES HAVE RISEN INTO THE MID 30S IN CLOUDY AREAS...WITH
MID TO UPPER 30S IN SUNNIER AREAS. COLD AIR ADVECTION WILL BATTLE
SUNSHINE AND MIXING...BUT MAY HAVE TO RAISE TEMPERATURES ANOTHER
DEGREE OR SO IN THESE AREAS IF CURRENT TRENDS CONTINUE.
&&
.AVIATION/18Z TAFS/...MVFR CLOUDS WILL AFFECT EASTERN TAF SITES
THROUGH ABOUT 20Z THIS AFTERNOON BEFORE MOVING OFF TO THE
SOUTHEAST. CLEARING SKIES THEN ARE EXPECTED AT TAF SITES THROUGH
THE REST OF THE AFTERNOON. GUSTY WEST NORTHWEST WINDS SHOULD
GRADUALLY SUBSIDE THROUGH THE REST OF THE AFTERNOON. AREA OF VFR
CLOUDS MAY CLIP THE AREA THIS EVENING...BUT MAY ERODE OR STAY
NORTH OF TAF SITES...SO WILL NOT PUT CEILINGS IN TAFS AT THIS
TIME.
PASSING HIGH PRESSURE LATER TONIGHT WILL BRING LIGHT AND VARIABLE
WINDS...WITH WINDS SHIFTING SOUTHWEST AND REMAINING LIGHT ON
SUNDAY. MOSTLY CLEAR SKIES LATER TONIGHT AND MOSTLY SUNNY SKIES
SUNDAY ARE EXPECTED...AS HIGH SHIFTS SOUTH OF THE AREA.
&&
.PREV DISCUSSION... /ISSUED 336 AM CST SAT JAN 7 2012/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM TO HIGH.
BIG CONCERN IS WITH TEMPERATURES TODAY. COLD AIR ADVECTION CONTINUES
THROUGH THE MORNING...WITH 925MB TEMPERATURES FALLING FROM CURRENT
LEVELS AROUND 0C TO +1 DOWN TO -4C TO -5C BY 18Z. ALSO WATCHING
STRATUS TRYING TO WORK SOUTHEAST FROM NORTHWEST WISCONSIN. MODEL
SOUNDINGS AND LOW-LEVEL RH FIELDS INDICATE THIS DECK WILL DROP
ACROSS SOUTHERN WISCONSIN DURING THE DAY. HOWEVER LEADING EDGE HAS
BEEN ERODING AS IT RUNS INTO SUBSIDENCE BEHIND EXITING WAVE...AND
MOVES AWAY FROM DEEPER SNOW FIELD TO THE NORTH. WILL ADJUST SKY IF
NEEDED AT ISSUANCE...BUT EVEN WITH MORE SUNSHINE...925MB
TEMPERATURES DICTATE NO MORE THAN MID TO UPPER 30S WITH THE COOLER
TEMPERATURES NORTH OVER THE SNOW PACK AND THE BETTER CHANCE AT SOME
CLOUD COVER.
QUIET AND COOL TONIGHT WITH A THIN SCATTERED TO BROKEN CIRRUS DECK
AT BEST AND LIGHT WINDS ALLOWING LOWS IN THE TEENS NORTH TO LOWER
20S SOUTH.
SUNDAY AND SUNDAY NIGHT...FORECAST CONFIDENCE HIGH.
HIGH PRESSURE WILL BE CENTERED OVER THE UPPER MIDWEST ON SUNDAY.
850MB TEMPS WILL BE WARMING SLIGHTLY...SO A DEGREE OR TWO WARMER
EXPECTED ON SUN THAN SAT WITH HIGHS IN THE MID/UPPER 30S TO AROUND
40. WITH THE EXCEPTION OF SOME THIN CIRRUS...NOT EXPECTING MUCH IN
THE WAY OF CLOUDS.
SUN NIGHT MIN TEMPS EXPECTED IN THE UPPER 20S WITH CONTINUED SUBTLE
850MB WARMING. CLEARING SKIES EXPECTED BEHIND THE PASSING 500MB
TROUGH.
MONDAY THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
HIGH PRESSURE AND WARMER THICKNESSES WILL MOVE INTO SOUTHERN WI.
TIGHT PRESSURE GRADIENT BETWEEN SFC HIGH PRESSURE OVER THE
PLAINS/MIDWEST AND A LOW TRACKING ACROSS SOUTHERN CANADA WILL BRING
A BRIEF PERIOD OF GUSTY SOUTHWEST TO WEST WINDS ACROSS WI ON MON
AFTERNOON WITH MIXING UP TO 950/925MB EXPECTED.
INCREASED MAX TEMPS ON MON AND TUE TO GENERALLY THE BIAS-CORRECTED
MOS GUIDANCE VALUES...WITH HIGHS IN THE 40S. ECMWF AND GFS ARE
FORECASTING THICKNESSES AROUND 548DM AND 850MB TEMPS AROUND +5C BY
00Z WED. A GOOD DEAL OF SUNSHINE EXPECTED WITH SFC HIGH PRESSURE AND
500MB RIDGING OVERHEAD.
LONG TERM...
WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
A CUTOFF 500MB LOW OVER TEXAS WILL MOVE ACROSS THE SOUTHEAST STATES
ON WEDNESDAY AND BRING A LARGE AMOUNT OF PRECIP TO THE NORTHEAST US
THROUGH THURSDAY...WHILE ANOTHER CUTOFF LOW DEVELOPS NEAR CALIFORNIA
AND ARIZONA. MEANWHILE...A STRONG 500MB TROUGH/VORT MAX WILL DROP
DOWN ACROSS THE UPPER MIDWEST AND UPPER GREAT LAKES REGION WED
AFTERNOON THROUGH THU.
WITH A DEEP UPPER LOW AND A SURFACE LOW OCCLUDING OVER NORTHERN LAKE
MICHIGAN OR LAKE SUPERIOR...A RATHER STRONG COLD FRONT WILL CROSS WI
BETWEEN WED AFTERNOON OR EVENING...DEPENDING ON THE MODEL OF CHOICE.
00Z ECMWF SFC PATTERN SEEMS TO HAVE GONE BACK TO LAST NIGHT/S 00Z
RUN...LAGGING THE SFC LOW OVER THE GREAT LAKES LONGER AND CAUSING
MORE WIDESPREAD PRECIP ACROSS WI THROUGH THU. THE GFS AND PREVIOUS
12Z ECMWF RUNS MOVE THE SFC LOW ALONG TO THE EAST COAST A LITTLE
QUICKER. ONLY SLIGHT CHANCES FOR PRECIP MENTIONED IN FCST WED NIGHT
THU AT THIS TIME.
PRECIPITATION MOST LIKELY IN THE FORM OF SNOW IS POSSIBLE WITH THIS
SFC LOW AND COLD FRONT...ALONG WITH WIDESPREAD CLOUD COVER. AT THIS
TIME...PRECIP AMOUNTS LOOK LIGHT WITH THE FAST-MOVING FRONT UNLESS
THE SLOWER ECMWF PANS OUT. GFS KEEPS SOUTHERN WI DRY WITH THIS
SYSTEM.
COLD AIR WILL SETTLE IN BEHIND THIS SYSTEM...WITH HIGH TEMPS MORE
AROUND NORMAL IN THE LOWER 20S THU AND FRI. THERE IS A CHANCE THAT
THESE TEMPS ARE A LITTLE TOO HIGH GIVEN THE EXPECTED 850MB TEMPS TO
BE AROUND -16C. HOWEVER...LATEST ECMWF AND GFS SHOW THIS TO BE
SHORT-LIVED...WITH HIGH PRESSURE AND WARMING TEMPS AGAIN FOR NEXT
WEEKEND.
AVIATION/12Z TAFS/...
ADDED LOW-LEVEL WIND SHEAR TO KMSN AND KMKE TAFS AS SURFACE WINDS
HAVE DECOUPLED WITH CLEARING SKIES AND 35-39KT NW WINDS AROUND
1300-1700 FT NOTED ON RUC SOUNDINGS SUPPORTED BY TAMDAR SOUNDING
FROM KRFD.
NEXT CONCERN IS WITH VFR CLOUD DECK DROPPING SE THROUGH THE STATE.
LEADING EDGE HAS BEEN ERODING AS IT RUNS INTO SUBSIDENCE BEHIND
DEPARTING WAVE AND MOVES AWAY FROM DEEPER SNOW COVER. WILL KEEP
SCATTERED STRATUS AT TAF SITES FOR NOW...AS BETTER CHANCE FOR A MORE
EXTENSIVE CLOUD COVER APPEARS TO BE NORTH...BUT WILL MONITOR
SATELLITE AND RAPID-UPDATE MODELS CLOSELY FOR DIFFERING TREND PRIOR
TO ISSUANCE.
MARINE...
WINDS HAVE REMAINED UNDER SMALL CRAFT CRITERIA OVER THE WARMER
WATERS OF THE LAKE...WITH SURFACE GRADIENT SLOWLY RELAXING THROUGH
THE DAY WITH THE APPROACH OF A HIGH PRESSURE RIDGE THAT CROSSES THE
REGION TONIGHT.
MONDAY/MONDAY EVENING WILL BE THE NEXT PERIOD OF CONCERN AS BRISK
SOUTHWEST WINDS AND SUBSEQUENT WAVES MAY REACH SMALL CRAFT ADVISORY
LEVELS ...AS LOW PRESSURE PASSES WELL NORTH OF THE REGION.
BRISK NORTHWEST WINDS AND ASSOCIATED WAVES MAY REACH SMALL CRAFT
ADVISORY LEVELS AT TIMES WEDNESDAY NIGHT THROUGH FRIDAY...BEHIND A
STRONG COLD FRONT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
533 AM CST SAT JAN 7 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
218 AM CST SAT JAN 7 2012
MAIN FORECAST CONCERNS ARE ON STRATUS TODAY AND TEMPERATURES
THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE EAST PACIFIC...AND SHORTWAVE TROUGHS OVER
THE PACIFIC NORTHWEST AND OVER WISCONSIN. THE FORECAST AREA LIES NOW
MOSTLY IN SUBSIDENCE ALOFT IN THE WAKE OF THE LATTER SHORTWAVE
TROUGH...AS WELL IN A COLD AIR ADVECTION REGIME. THIS COLD ADVECTION
WAS NOTED BY A FALL IN 850MB TEMPS AT MPX FROM 6C AT 12Z FRIDAY TO
-2C AT 00Z SATURDAY PER SOUNDINGS. ACCOMPANYING THE COLD ADVECTION
IS A STRATUS DECK...WHICH IS FARTHER SOUTH AND WEST THAN PREVIOUSLY
ANTICIPATED. LATEST 11-3.9UM SATELLITE IMAGERY DEPICTS THE STRATUS
ENCOMPASSING MUCH OF MINNESOTA...EXCLUDING THE SOUTHWEST CORNER...AS
WELL AS ABOUT THE NORTHERN HALF OF THE FORECAST AREA. 00Z INL
SOUNDING REFLECTIVE OF THE STRATUS SHOWING NEAR SATURATED CONDITIONS
FROM THE SURFACE UP THROUGH AN INVERSION AROUND 850MB. THE STRATUS
HAS HELPED TO KEEP TEMPERATURES UP MOSTLY IN THE 30S. COOLER 20S
READINGS CAN BE SEEN DROPPING SOUTH THROUGH NORTHERN MN...IN THE WAKE OF
A SECONDARY COLD FRONT NEAR THE MINNEAPOLIS AREA.
TODAY AND TONIGHT...WEAK TROUGHING IS FORECAST TO PERSIST OVER THE
FORECAST AREA THROUGH TONIGHT WHILE THE SHORTWAVE TROUGH IN THE
PACIFIC NORTHWEST DIGS DOWN INTO ARIZONA. WITH LITTLE UPPER LEVEL
FORCING PROGGED...NOT ANTICIPATING MUCH IN THE WAY OF PRECIPITATION.
MAIN FOCUS IS ON THE STRATUS. SECONDARY COLD FRONT NEAR
MINNEAPOLIS LOOKS TO SLIDE SOUTHEAST THROUGH THE FORECAST AREA
THIS MORNING...WHICH SHOULD ALLOW THE STRATUS TO COME IN AND
ENCOMPASS MUCH OF THE AREA. NOW COMES THE PROBLEM. THE 07.00Z NAM
HOLDS THE STRATUS AROUND ALL DAY TODAY AND EVEN MUCH OF TONIGHT
BEFORE 925MB WINDS BACKING WEST HELP CLEAR IT OUT. FURTHER
INVESTIGATION...HOWEVER...SHOWS THAT ITS DEPICTION OF THE CURRENT
SNOW PACK IS WAY OFF...STILL HAVING SNOW COVER DOWN TO I-94 AS
WELL AS OVER SOUTH CENTRAL AND SOUTHEAST MINNESOTA. THIS SNOW
COVER IS LIKELY KEEPING THE NAM FROM MIXING OUT THE CLOUD DECK.
PREFER THE RUC SCENARIOS WHICH HAVE A DECENT HANDLE ON THE CURRENT
CLOUDS BUT SHOWS SCATTERING OF IT LATE THIS MORNING THROUGH THE
AFTERNOON. PERHAPS THE ONLY AREA THAT THE CLOUDS WOULD PERSIST IS
NORTH OF HIGHWAY 29 WHERE SNOW EXISTS IN REALITY...AND IN FACT
COULD STAY THERE RIGHT THROUGH TONIGHT. ELSEWHERE...ONCE THE LOW
CLOUDS CLEAR...SOME SCATTERED-BROKEN CIRRUS IS POSSIBLE THIS
AFTERNOON AND TONIGHT SOUTH OF I-90. REGARDING TEMPERATURES...WITH
THE STRATUS CONCERNS TODAY...DID NUDGE HIGHS DOWN A LITTLE. A
BLEND OF GUIDANCE SEEMS REASONABLE FOR LOWS TONIGHT...WITH A LACK
OF SNOW HELPING TO PREVENT TEMPERATURES FROM TANKING AS MUCH AS
THEY COULD...GIVEN AN OTHERWISE FAVORABLE RADIATIONAL COOLING
SETUP.
SUNDAY THROUGH MONDAY NIGHT...UPPER RIDGING CURRENTLY OVER THE EAST
PACIFIC IS PROGGED TO BUILD INTO THE NORTHERN ROCKIES SUNDAY AND
SUNDAY NIGHT...THEN PUSH EAST AND FLATTEN OUT FOR MONDAY AND MONDAY
NIGHT AS A POTENT SHORTWAVE TROUGH DIGS DOWN INTO BRITISH COLUMBIA.
ON TOP OF THE UPPER RIDGE...ALL MODELS SHOW A SHORTWAVE RIDING ALONG
IT...CROSSING MANITOBA AND ONTARIO SUNDAY NIGHT. WITH THIS
SHORTWAVE...A CHINOOK WARM FRONT ACCOMPANIES IT...CROSSING THE
FORECAST AREA SUNDAY NIGHT. 925MB TEMPS RESPOND BY CLIMBING FROM -2
TO -4C AT 12Z SUNDAY TO 0 TO +2C BY 12Z MONDAY. NOT ANTICIPATING ANY
PRECIPITATION WITH THE FRONTAL PASSAGE...HOWEVER...SOME MID AND HIGH
CLOUDS ARE LIKELY. THESE MID AND HIGH CLOUDS COULD EVEN HANG AROUND
THROUGH MONDAY...ESPECIALLY NORTH OF I-90. OUTSIDE OF THE CLOUD
ISSUE...WITH NO PRECIPITATION EXPECTED...MAIN CONCERN IS
TEMPERATURES. SHOULD SEE QUITE A BIT OF SUN ON SUNDAY...EXCLUDING
MAYBE NORTH OF I-94...ALLOWING HIGHS TO REACH INTO THE 30S TO LOW
40S...WARMEST SOUTH OF I-90. FOLLOWED THE PREVIOUS SHIFT AND KEPT A
NON-DIURNAL TREND IN FOR SUNDAY NIGHT...HAVING A DROP OFF IN THE
EVENING THEN STEADY OR CLIMBING AFTER MIDNIGHT WITH THE WARM FRONTAL
PASSAGE. WARMER 925MB TEMPS ON MONDAY IN CONJUNCTION WITH PARTLY TO
MOSTLY SUNNY SKIES SHOULD ALLOW TEMPERATURES TO CLIMB INTO THE 40S
IN MOST AREAS. THE ONLY EXCEPTION AGAIN IS NORTH OF I-94 DUE TO SNOW
COVER AND CLOUD CONCERNS. READINGS THERE MAY ONLY REACH THE UPPER
30S. MONDAY NIGHT TEMPERATURES ARE TRICKY. 925MB READINGS ACTUALLY
WARM THROUGH THE NIGHT...REACHING 4-6C AT 12Z TUESDAY. 950MB WINDS
STAY UP AT 20 KT OR MORE FOR MOST OF THE NIGHT. HIGHER TERRAIN
LOCATIONS MAY STRUGGLE TO DECOUPLE AS A RESULT...KEEPING LOWS UP
THERE. LOCATIONS THAT DO DECOUPLE COULD DROP INTO THE UPPER 20S/LOW
30S.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
218 AM CST SAT JAN 7 2012
MODELS CONTINUE TO SHOW A PATTERN CHANGE FOR THE LONG TERM PORTION
OF THE FORECAST...ALL STARTED BY THAT POTENT TROUGH COMING INTO
SOUTHWEST CANADA MONDAY NIGHT. INITIALLY TUESDAY LOOKS WELL ABOVE
NORMAL...THANKS TO WARM ADVECTION CONTINUING DOWNSTREAM OF THIS
POTENT TROUGH. 925MB TEMPS ARE PROGGED TO WARM TO 4-6C BY 18Z
TUESDAY WHICH SHOULD ALLOW MOST LOCATIONS TO SEE HIGHS IN THE 40S...
WITH 50S CERTAINLY POSSIBLE. THE COOL DOWN THEN BEGINS TUESDAY
NIGHT AS THE POTENT TROUGH DIGS DOWN INTO THE DAKOTAS...SENDING A
COLD FRONT THROUGH MUCH OF THE FORECAST AREA BY 12Z WEDNESDAY.
925MB TEMPS FALL TO -4C TO +2C AT THAT TIME...COLDEST IN SOUTHEAST
MN. THE POTENT TROUGH FULLY MOVES INTO THE FORECAST AREA WEDNESDAY
NIGHT...SENDING 850MB TEMPS DOWN TO NEAR -20C AND 925MB TEMPS TO
-15C BY 12Z THURSDAY. ACCOMPANYING THE COLD ADVECTION SHOULD BE
SOME STRONG WINDS. RIGHT NOW GUSTS LOOK TO STAY BELOW ADVISORY
CRITERIA BUT IS SOMETHING TO WATCH. ANOTHER ITEM TO WATCH IS
POTENTIAL FOR FALLING TEMPERATURES ON WEDNESDAY. GIVEN HOW FAR OUT
THIS IS IN THE FORECAST...AND HOW CRITICAL TIMING OF THE COLD AIR
WOULD BE TO HAVE A FALLING TEMPERATURE TREND...HAVE NOT INCLUDED
IT IN THE FORECAST YET. AFTER THURSDAY...UNCERTAINTY EXISTS ON HOW
QUICK THE POTENT TROUGH EXITS. THE 07.00Z GFS IS BY FAR THE
FASTEST...EJECTING IT UP INTO SOUTHEAST CANADA ON FRIDAY. THIS
SCENARIO WOULD RESULT IN SOME STRONG WARMING FOR FRIDAY AND FRIDAY
NIGHT AS 500MB HEIGHTS RISE. THE 07.00Z GFS ENSEMBLES PORTRAY A
SLOWER SCENARIO...PERHAPS SLIGHTLY CLOSER TO THE 07.00Z ECMWF.
THESE SCENARIOS WOULD STILL ALLOW FOR WARMING...BUT NOT AS
AGGRESSIVE...NOTED BY 850MB TEMPS CLIMBING TO AROUND -10C AT 00Z
SATURDAY VERSUS THE GFS WHICH IS AROUND -2C. PREFER THESE SLOWER
SCENARIOS...WHICH IS CLOSE TO WHAT A CONSENSUS BLEND OF
TEMPERATURES WOULD YIELD.
REGARDING PRECIPITATION CHANCES...THE ONLY THREAT OF IT WOULD COME
WEDNESDAY INTO THURSDAY AS THE POTENT TROUGH COMES ACROSS. MAIN
FEATURE TO WATCH IS IF A TROWAL REGION CAN WRAP BACK INTO THE
FORECAST AREA AS SUGGESTED BY THE 06.00Z AND 07.00Z ECMWF RUNS. FOR
NOW...THERE HAS BEEN TOO MUCH INCONSISTENCY OF THIS FEATURE OF IT
COMING INTO THE FORECAST AREA...BOTH BETWEEN MODELS AND RUN TO RUN.
THEREFORE...PRECIPITATION CHANCES ARE HELD TO NO MORE THAN 20 AND
MAINLY NORTH OF I-90.
&&
.AVIATION...TODAY AND TONIGHT
533 AM CST SAT JAN 7 2012
STRATUS WILL MOVE ACROSS THE TAF SITES THIS MORNING PRODUCING
PERIODS OF MVFR CONDITIONS. PLAN ON CLOUD BASES IN THE 1900 TO
3000 FT RANGE. THE STRATUS IS EXPECTED TO GRADUALLY CLEAR THIS
AFTERNOON AS HIGH PRESSURE MOVES IN. VFR CONDITIONS ARE EXPECTED
THIS AFTERNOON THROUGH THE OVERNIGHT HOURS. NORTHWEST WINDS AT 12
TO 16 KTS...GUSTING TO AROUND 22 KTS...WILL DIMINISH LATE THIS
AFTERNOON INTO THE 6 TO 8 KT RANGE. LOOK FOR WINDS TO BECOME LIGHT
AND VARIABLE TONIGHT AS THE HIGH MOVES OVERHEAD. A FEW CIRRUS
CLOUDS MAY SPILL INTO THE REGION TONIGHT FROM A TROUGH MOVING INTO
THE CENTRAL PLAINS. VFR CONDITIONS WILL PREVAIL THROUGH SUNDAY
MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
218 AM CST SAT JAN 7 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....WETENKAMP
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
336 AM CST SAT JAN 7 2012
.SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM TO HIGH.
BIG CONCERN IS WITH TEMPERATURES TODAY. COLD AIR ADVECTION CONTINUES
THROUGH THE MORNING...WITH 925MB TEMPERATURES FALLING FROM CURRENT
LEVELS AROUND 0C TO +1 DOWN TO -4C TO -5C BY 18Z. ALSO WATCHING
STRATUS TRYING TO WORK SOUTHEAST FROM NORTHWEST WISCONSIN. MODEL
SOUNDINGS AND LOW-LEVEL RH FIELDS INDICATE THIS DECK WILL DROP
ACROSS SOUTHERN WISCONSIN DURING THE DAY. HOWEVER LEADING EDGE HAS
BEEN ERODING AS IT RUNS INTO SUBSIDENCE BEHIND EXITING WAVE...AND
MOVES AWAY FROM DEEPER SNOW FIELD TO THE NORTH. WILL ADJUST SKY IF
NEEDED AT ISSUANCE...BUT EVEN WITH MORE SUNSHINE...925MB
TEMPERATURES DICTATE NO MORE THAN MID TO UPPER 30S WITH THE COOLER
TEMPERATURES NORTH OVER THE SNOW PACK AND THE BETTER CHANCE AT SOME
CLOUD COVER.
QUIET AND COOL TONIGHT WITH A THIN SCATTERED TO BROKEN CIRRUS DECK
AT BEST AND LIGHT WINDS ALLOWING LOWS IN THE TEENS NORTH TO LOWER
20S SOUTH.
SUNDAY AND SUNDAY NIGHT...FORECAST CONFIDENCE HIGH.
HIGH PRESSURE WILL BE CENTERED OVER THE UPPER MIDWEST ON SUNDAY.
850MB TEMPS WILL BE WARMING SLIGHTLY...SO A DEGREE OR TWO WARMER
EXPECTED ON SUN THAN SAT WITH HIGHS IN THE MID/UPPER 30S TO AROUND
40. WITH THE EXCEPTION OF SOME THIN CIRRUS...NOT EXPECTING MUCH IN
THE WAY OF CLOUDS.
SUN NIGHT MIN TEMPS EXPECTED IN THE UPPER 20S WITH CONTINUED SUBTLE
850MB WARMING. CLEARING SKIES EXPECTED BEHIND THE PASSING 500MB
TROUGH.
MONDAY THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.
HIGH PRESSURE AND WARMER THICKNESSES WILL MOVE INTO SOUTHERN WI.
TIGHT PRESSURE GRADIENT BETWEEN SFC HIGH PRESSURE OVER THE
PLAINS/MIDWEST AND A LOW TRACKING ACROSS SOUTHERN CANADA WILL BRING
A BRIEF PERIOD OF GUSTY SOUTHWEST TO WEST WINDS ACROSS WI ON MON
AFTERNOON WITH MIXING UP TO 950/925MB EXPECTED.
INCREASED MAX TEMPS ON MON AND TUE TO GENERALLY THE BIAS-CORRECTED
MOS GUIDANCE VALUES...WITH HIGHS IN THE 40S. ECMWF AND GFS ARE
FORECASTING THICKNESSES AROUND 548DM AND 850MB TEMPS AROUND +5C BY
00Z WED. A GOOD DEAL OF SUNSHINE EXPECTED WITH SFC HIGH PRESSURE AND
500MB RIDGING OVERHEAD.
.LONG TERM...
WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM.
A CUTOFF 500MB LOW OVER TEXAS WILL MOVE ACROSS THE SOUTHEAST STATES
ON WEDNESDAY AND BRING A LARGE AMOUNT OF PRECIP TO THE NORTHEAST US
THROUGH THURSDAY...WHILE ANOTHER CUTOFF LOW DEVELOPS NEAR CALIFORNIA
AND ARIZONA. MEANWHILE...A STRONG 500MB TROUGH/VORT MAX WILL DROP
DOWN ACROSS THE UPPER MIDWEST AND UPPER GREAT LAKES REGION WED
AFTERNOON THROUGH THU.
WITH A DEEP UPPER LOW AND A SURFACE LOW OCCLUDING OVER NORTHERN LAKE
MICHIGAN OR LAKE SUPERIOR...A RATHER STRONG COLD FRONT WILL CROSS WI
BETWEEN WED AFTERNOON OR EVENING...DEPENDING ON THE MODEL OF CHOICE.
00Z ECMWF SFC PATTERN SEEMS TO HAVE GONE BACK TO LAST NIGHT/S 00Z
RUN...LAGGING THE SFC LOW OVER THE GREAT LAKES LONGER AND CAUSING
MORE WIDESPREAD PRECIP ACROSS WI THROUGH THU. THE GFS AND PREVIOUS
12Z ECMWF RUNS MOVE THE SFC LOW ALONG TO THE EAST COAST A LITTLE
QUICKER. ONLY SLIGHT CHANCES FOR PRECIP MENTIONED IN FCST WED NIGHT
THU AT THIS TIME.
PRECIPITATION MOST LIKELY IN THE FORM OF SNOW IS POSSIBLE WITH THIS
SFC LOW AND COLD FRONT...ALONG WITH WIDESPREAD CLOUD COVER. AT THIS
TIME...PRECIP AMOUNTS LOOK LIGHT WITH THE FAST-MOVING FRONT UNLESS
THE SLOWER ECMWF PANS OUT. GFS KEEPS SOUTHERN WI DRY WITH THIS
SYSTEM.
COLD AIR WILL SETTLE IN BEHIND THIS SYSTEM...WITH HIGH TEMPS MORE
AROUND NORMAL IN THE LOWER 20S THU AND FRI. THERE IS A CHANCE THAT
THESE TEMPS ARE A LITTLE TOO HIGH GIVEN THE EXPECTED 850MB TEMPS TO
BE AROUND -16C. HOWEVER...LATEST ECMWF AND GFS SHOW THIS TO BE
SHORT-LIVED...WITH HIGH PRESSURE AND WARMING TEMPS AGAIN FOR NEXT
WEEKEND.
&&
.AVIATION/12Z TAFS/...
ADDED LOW-LEVEL WIND SHEAR TO KMSN AND KMKE TAFS AS SURFACE WINDS
HAVE DECOUPLED WITH CLEARING SKIES AND 35-39KT NW WINDS AROUND
1300-1700 FT NOTED ON RUC SOUNDINGS SUPPORTED BY TAMDAR SOUNDING
FROM KRFD.
NEXT CONCERN IS WITH VFR CLOUD DECK DROPPING SE THROUGH THE STATE.
LEADING EDGE HAS BEEN ERODING AS IT RUNS INTO SUBSIDENCE BEHIND
DEPARTING WAVE AND MOVES AWAY FROM DEEPER SNOW COVER. WILL KEEP
SCATTERED STRATUS AT TAF SITES FOR NOW...AS BETTER CHANCE FOR A MORE
EXTENSIVE CLOUD COVER APPEARS TO BE NORTH...BUT WILL MONITOR
SATELLITE AND RAPID-UPDATE MODELS CLOSELY FOR DIFFERING TREND PRIOR
TO ISSUANCE.
&&
.MARINE...
WINDS HAVE REMAINED UNDER SMALL CRAFT CRITERIA OVER THE WARMER
WATERS OF THE LAKE...WITH SURFACE GRADIENT SLOWLY RELAXING THROUGH
THE DAY WITH THE APPROACH OF A HIGH PRESSURE RIDGE THAT CROSSES THE
REGION TONIGHT.
MONDAY/MONDAY EVENING WILL BE THE NEXT PERIOD OF CONCERN AS BRISK
SOUTHWEST WINDS AND SUBSEQUENT WAVES MAY REACH SMALL CRAFT ADVISORY
LEVELS ...AS LOW PRESSURE PASSES WELL NORTH OF THE REGION.
BRISK NORTHWEST WINDS AND ASSOCIATED WAVES MAY REACH SMALL CRAFT
ADVISORY LEVELS AT TIMES WEDNESDAY NIGHT THROUGH FRIDAY...BEHIND A
STRONG COLD FRONT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
218 AM CST SAT JAN 7 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
218 AM CST SAT JAN 7 2012
MAIN FORECAST CONCERNS ARE ON STRATUS TODAY AND TEMPERATURES
THROUGHOUT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE EAST PACIFIC...AND SHORTWAVE TROUGHS OVER
THE PACIFIC NORTHWEST AND OVER WISCONSIN. THE FORECAST AREA LIES NOW
MOSTLY IN SUBSIDENCE ALOFT IN THE WAKE OF THE LATTER SHORTWAVE
TROUGH...AS WELL IN A COLD AIR ADVECTION REGIME. THIS COLD ADVECTION
WAS NOTED BY A FALL IN 850MB TEMPS AT MPX FROM 6C AT 12Z FRIDAY TO
-2C AT 00Z SATURDAY PER SOUNDINGS. ACCOMPANYING THE COLD ADVECTION
IS A STRATUS DECK...WHICH IS FARTHER SOUTH AND WEST THAN PREVIOUSLY
ANTICIPATED. LATEST 11-3.9UM SATELLITE IMAGERY DEPICTS THE STRATUS
ENCOMPASSING MUCH OF MINNESOTA...EXCLUDING THE SOUTHWEST CORNER...AS
WELL AS ABOUT THE NORTHERN HALF OF THE FORECAST AREA. 00Z INL
SOUNDING REFLECTIVE OF THE STRATUS SHOWING NEAR SATURATED CONDITIONS
FROM THE SURFACE UP THROUGH AN INVERSION AROUND 850MB. THE STRATUS
HAS HELPED TO KEEP TEMPERATURES UP MOSTLY IN THE 30S. COOLER 20S
READINGS CAN BE SEEN DROPPING SOUTH THROUGH NORTHERN MN...IN THE WAKE OF
A SECONDARY COLD FRONT NEAR THE MINNEAPOLIS AREA.
TODAY AND TONIGHT...WEAK TROUGHING IS FORECAST TO PERSIST OVER THE
FORECAST AREA THROUGH TONIGHT WHILE THE SHORTWAVE TROUGH IN THE
PACIFIC NORTHWEST DIGS DOWN INTO ARIZONA. WITH LITTLE UPPER LEVEL
FORCING PROGGED...NOT ANTICIPATING MUCH IN THE WAY OF PRECIPITATION.
MAIN FOCUS IS ON THE STRATUS. SECONDARY COLD FRONT NEAR
MINNEAPOLIS LOOKS TO SLIDE SOUTHEAST THROUGH THE FORECAST AREA
THIS MORNING...WHICH SHOULD ALLOW THE STRATUS TO COME IN AND
ENCOMPASS MUCH OF THE AREA. NOW COMES THE PROBLEM. THE 07.00Z NAM
HOLDS THE STRATUS AROUND ALL DAY TODAY AND EVEN MUCH OF TONIGHT
BEFORE 925MB WINDS BACKING WEST HELP CLEAR IT OUT. FURTHER
INVESTIGATION...HOWEVER...SHOWS THAT ITS DEPICTION OF THE CURRENT
SNOW PACK IS WAY OFF...STILL HAVING SNOW COVER DOWN TO I-94 AS
WELL AS OVER SOUTH CENTRAL AND SOUTHEAST MINNESOTA. THIS SNOW
COVER IS LIKELY KEEPING THE NAM FROM MIXING OUT THE CLOUD DECK.
PREFER THE RUC SCENARIOS WHICH HAVE A DECENT HANDLE ON THE CURRENT
CLOUDS BUT SHOWS SCATTERING OF IT LATE THIS MORNING THROUGH THE
AFTERNOON. PERHAPS THE ONLY AREA THAT THE CLOUDS WOULD PERSIST IS
NORTH OF HIGHWAY 29 WHERE SNOW EXISTS IN REALITY...AND IN FACT
COULD STAY THERE RIGHT THROUGH TONIGHT. ELSEWHERE...ONCE THE LOW
CLOUDS CLEAR...SOME SCATTERED-BROKEN CIRRUS IS POSSIBLE THIS
AFTERNOON AND TONIGHT SOUTH OF I-90. REGARDING TEMPERATURES...WITH
THE STRATUS CONCERNS TODAY...DID NUDGE HIGHS DOWN A LITTLE. A
BLEND OF GUIDANCE SEEMS REASONABLE FOR LOWS TONIGHT...WITH A LACK
OF SNOW HELPING TO PREVENT TEMPERATURES FROM TANKING AS MUCH AS
THEY COULD...GIVEN AN OTHERWISE FAVORABLE RADIATIONAL COOLING
SETUP.
SUNDAY THROUGH MONDAY NIGHT...UPPER RIDGING CURRENTLY OVER THE EAST
PACIFIC IS PROGGED TO BUILD INTO THE NORTHERN ROCKIES SUNDAY AND
SUNDAY NIGHT...THEN PUSH EAST AND FLATTEN OUT FOR MONDAY AND MONDAY
NIGHT AS A POTENT SHORTWAVE TROUGH DIGS DOWN INTO BRITISH COLUMBIA.
ON TOP OF THE UPPER RIDGE...ALL MODELS SHOW A SHORTWAVE RIDING ALONG
IT...CROSSING MANITOBA AND ONTARIO SUNDAY NIGHT. WITH THIS
SHORTWAVE...A CHINOOK WARM FRONT ACCOMPANIES IT...CROSSING THE
FORECAST AREA SUNDAY NIGHT. 925MB TEMPS RESPOND BY CLIMBING FROM -2
TO -4C AT 12Z SUNDAY TO 0 TO +2C BY 12Z MONDAY. NOT ANTICIPATING ANY
PRECIPITATION WITH THE FRONTAL PASSAGE...HOWEVER...SOME MID AND HIGH
CLOUDS ARE LIKELY. THESE MID AND HIGH CLOUDS COULD EVEN HANG AROUND
THROUGH MONDAY...ESPECIALLY NORTH OF I-90. OUTSIDE OF THE CLOUD
ISSUE...WITH NO PRECIPITATION EXPECTED...MAIN CONCERN IS
TEMPERATURES. SHOULD SEE QUITE A BIT OF SUN ON SUNDAY...EXCLUDING
MAYBE NORTH OF I-94...ALLOWING HIGHS TO REACH INTO THE 30S TO LOW
40S...WARMEST SOUTH OF I-90. FOLLOWED THE PREVIOUS SHIFT AND KEPT A
NON-DIURNAL TREND IN FOR SUNDAY NIGHT...HAVING A DROP OFF IN THE
EVENING THEN STEADY OR CLIMBING AFTER MIDNIGHT WITH THE WARM FRONTAL
PASSAGE. WARMER 925MB TEMPS ON MONDAY IN CONJUNCTION WITH PARTLY TO
MOSTLY SUNNY SKIES SHOULD ALLOW TEMPERATURES TO CLIMB INTO THE 40S
IN MOST AREAS. THE ONLY EXCEPTION AGAIN IS NORTH OF I-94 DUE TO SNOW
COVER AND CLOUD CONCERNS. READINGS THERE MAY ONLY REACH THE UPPER
30S. MONDAY NIGHT TEMPERATURES ARE TRICKY. 925MB READINGS ACTUALLY
WARM THROUGH THE NIGHT...REACHING 4-6C AT 12Z TUESDAY. 950MB WINDS
STAY UP AT 20 KT OR MORE FOR MOST OF THE NIGHT. HIGHER TERRAIN
LOCATIONS MAY STRUGGLE TO DECOUPLE AS A RESULT...KEEPING LOWS UP
THERE. LOCATIONS THAT DO DECOUPLE COULD DROP INTO THE UPPER 20S/LOW
30S.
.LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
218 AM CST SAT JAN 7 2012
MODELS CONTINUE TO SHOW A PATTERN CHANGE FOR THE LONG TERM PORTION
OF THE FORECAST...ALL STARTED BY THAT POTENT TROUGH COMING INTO
SOUTHWEST CANADA MONDAY NIGHT. INITIALLY TUESDAY LOOKS WELL ABOVE
NORMAL...THANKS TO WARM ADVECTION CONTINUING DOWNSTREAM OF THIS
POTENT TROUGH. 925MB TEMPS ARE PROGGED TO WARM TO 4-6C BY 18Z
TUESDAY WHICH SHOULD ALLOW MOST LOCATIONS TO SEE HIGHS IN THE 40S...
WITH 50S CERTAINLY POSSIBLE. THE COOL DOWN THEN BEGINS TUESDAY
NIGHT AS THE POTENT TROUGH DIGS DOWN INTO THE DAKOTAS...SENDING A
COLD FRONT THROUGH MUCH OF THE FORECAST AREA BY 12Z WEDNESDAY.
925MB TEMPS FALL TO -4C TO +2C AT THAT TIME...COLDEST IN SOUTHEAST
MN. THE POTENT TROUGH FULLY MOVES INTO THE FORECAST AREA WEDNESDAY
NIGHT...SENDING 850MB TEMPS DOWN TO NEAR -20C AND 925MB TEMPS TO
-15C BY 12Z THURSDAY. ACCOMPANYING THE COLD ADVECTION SHOULD BE
SOME STRONG WINDS. RIGHT NOW GUSTS LOOK TO STAY BELOW ADVISORY
CRITERIA BUT IS SOMETHING TO WATCH. ANOTHER ITEM TO WATCH IS
POTENTIAL FOR FALLING TEMPERATURES ON WEDNESDAY. GIVEN HOW FAR OUT
THIS IS IN THE FORECAST...AND HOW CRITICAL TIMING OF THE COLD AIR
WOULD BE TO HAVE A FALLING TEMPERATURE TREND...HAVE NOT INCLUDED
IT IN THE FORECAST YET. AFTER THURSDAY...UNCERTAINTY EXISTS ON HOW
QUICK THE POTENT TROUGH EXITS. THE 07.00Z GFS IS BY FAR THE
FASTEST...EJECTING IT UP INTO SOUTHEAST CANADA ON FRIDAY. THIS
SCENARIO WOULD RESULT IN SOME STRONG WARMING FOR FRIDAY AND FRIDAY
NIGHT AS 500MB HEIGHTS RISE. THE 07.00Z GFS ENSEMBLES PORTRAY A
SLOWER SCENARIO...PERHAPS SLIGHTLY CLOSER TO THE 07.00Z ECMWF.
THESE SCENARIOS WOULD STILL ALLOW FOR WARMING...BUT NOT AS
AGGRESSIVE...NOTED BY 850MB TEMPS CLIMBING TO AROUND -10C AT 00Z
SATURDAY VERSUS THE GFS WHICH IS AROUND -2C. PREFER THESE SLOWER
SCENARIOS...WHICH IS CLOSE TO WHAT A CONSENSUS BLEND OF
TEMPERATURES WOULD YIELD.
REGARDING PRECIPITATION CHANCES...THE ONLY THREAT OF IT WOULD COME
WEDNESDAY INTO THURSDAY AS THE POTENT TROUGH COMES ACROSS. MAIN
FEATURE TO WATCH IS IF A TROWAL REGION CAN WRAP BACK INTO THE
FORECAST AREA AS SUGGESTED BY THE 06.00Z AND 07.00Z ECMWF RUNS. FOR
NOW...THERE HAS BEEN TOO MUCH INCONSISTENCY OF THIS FEATURE OF IT
COMING INTO THE FORECAST AREA...BOTH BETWEEN MODELS AND RUN TO RUN.
THEREFORE...PRECIPITATION CHANCES ARE HELD TO NO MORE THAN 20 AND
MAINLY NORTH OF I-90.
&&
.AVIATION...
1110 PM CST FRI JAN 6 2012
DIFFICULT CLOUD FORECAST FOR KRST/KLSE WITH MIXED SIGNALS IN THE
MODELS. LATEST NAM12/RUC13 DOING THE BEST JOB WITH THE CURRENT LOW
CLOUD DECK SINKING SOUTHEAST ACROSS THE REGION. IT WAS MOSTLY MVFR
WITH CIGS AROUND 2500 FT. THE RUC13 SUGGEST A GRADUAL CLEARING FROM
WEST TO EAST LATE MORNING/EARLY AFTERNOON...WHILE THE NAM HANGS ON
INTO EARLY EVENING. HOWEVER...THE NAM IS ALSO HANGING ONTO SOME SNOW
COVER WHICH IS NOT THERE...AND LIKELY LEADING TO AN OVER ABUNDANCE
OF 925 RH. HAVE OPTED TO LEAN ON THE RUC TRENDS WITH THE 06Z TAF
ISSUANCE. EXPECT THERE WILL NEED TO BE SOME UPDATES AS TIMING BECOME
MORE CLEAR.
HIGH PRESSURE WILL BUILD IN FROM THE NORTHERN PLAINS SAT NIGHT...AND
WINDS SHOULD BECOME LIGHT FROM THE SOUTH WITH SKC/SCT SKIES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
218 AM CST SAT JAN 7 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1110 PM CST FRI JAN 6 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT
241 PM CST FRI JAN 6 2012
AT 3 PM...A COLD FRONT WAS LOCATED FROM SAULT STE MARIE MICHIGAN
TO LUBBOCK TEXAS. WITH THE AIR MASS BEING OF PACIFIC ORIGIN...
THERE WAS ONLY A SLIGHT DECREASE IN THE TEMPERATURES BEHIND THE
FRONT. TEMPERATURES ACROSS THE AREA WERE MAINLY IN THE 40S TODAY.
IF IT WERE NOT FOR THE EXTENSIVE MID CLOUDS ACROSS THE AREA...
TEMPERATURES MAY HAVE CLIMBED A FEW MORE DEGREES. WHERE SKIES HAVE
BEEN CLEARING /NORTH OF A DODGE CENTER MINNESOTA TO ESCANABA
MICHIGAN LINE/...TEMPERATURES HAVE CLIMBED A COUPLE OF DEGREES...
SO MAY CLIMB A FEW MORE DEGREES IN THE AREAS THAT CLEAR OUT LATE
THIS AFTERNOON.
TONIGHT...06.12Z MODELS ARE IN AGREEMENT THAT ANOTHER COLD FRONT
WILL MOVE SOUTHEAST THROUGH THE AREA. LIKE ITS PREDECESSOR...THIS
FRONT IS EXPECTED TO MOVE THROUGH THE REGION DRY. BEHIND THIS
FRONT...THERE WILL BE ANOTHER SLIGHT DROP IN TEMPERATURES. 925 MB
TEMPERATURES DROP FROM 2 TO 6C AHEAD OF THE FRONT TO -2 TO -6C
BEHIND THIS FRONT. LOW TEMPERATURES WILL FALL OFF INTO THE MID AND
UPPER 20S. THIS IS ABOUT 5 DEGREES WARMER THAN OUR NORMAL DAILY HIGH
TEMPERATURES FOR THIS TIME OF YEAR. IN ADDITION TO THE COOLER
TEMPERATURES...SOME LOW CLOUDS ARE MOVING SOUTHEAST TOWARD THE AREA.
WITH THEIR CURRENT TRAJECTORY...THINKING THAT THE BEST CHANCE OF
SEEING THESE CLOUDS WILL BE NORTHEAST OF A LAKE CITY MINNESOTA TO
THE WISCONSIN DELLS. THERE MAY BE EVEN A PERIOD OF LIGHT SNOW OR
FLURRIES NORTH OF THE INTERSTATE 94 CORRIDOR. HOWEVER NO SNOW
ACCUMULATIONS ARE EXPECTED.
ON SATURDAY...CLOUDS WILL LINGER ALONG AND NORTH OF THE INTERSTATE
94 CORRIDOR DURING THE MORNING AND GRADUALLY CLEAR DURING THE
AFTERNOON. THE COMBINATION OF THESE CLOUDS AND THE COOL 925 MB
TEMPERATURES WILL KEEP THESE TEMPERATURES IN THESE AREAS CONFINED
TO THE LOWER AND MID 30S. MEANWHILE THE REMAINDER OF THE AREA
WILL SEE TEMPERATURES IN THE UPPER 30S AND LOWER 40S.
ON SUNDAY NIGHT...A WARM FRONT WILL MOVE SOUTHEAST THROUGH THE
REGION. THE 925 MB TEMPERATURES WILL CLIMB FROM -2 TO -4C AHEAD OF
THIS FRONT TO 0 TO 4C BEHIND THIS FRONT. COLDEST TEMPERATURES ARE
EXPECTED DURING THE EVENING AND THEN EITHER REMAIN STEADY OR
SLOWLY CLIMB DURING THE OVERNIGHT. AS A RESULT...WENT WITH A NON
DIURNAL TEMPERATURE CURVE FOR THIS TIME PERIOD.
.LONG TERM...MONDAY THROUGH FRIDAY
241 PM CST FRI JAN 6 2012
FROM MONDAY INTO TUESDAY...925 MB TEMPERATURES WILL RANGE FROM
4 TO 8C. THIS IS JUST A FEW DEGREES COOLER THAN THEY WERE
YESTERDAY. AS A RESULT...EXPECT TO SEE A RETURN TO MUCH ABOVE
NORMAL TEMPERATURES. CURRENTLY WENT WITH HIGH TEMPERATURES ON BOTH
DAYS IN THE 40S...BUT WOULD NOT BE TOO SURPRISED THAT WE MAY SEE
ANOTHER ROUND OF 50 DEGREE TEMPERATURES.
ON WEDNESDAY...AN UPPER AIR PATTERN SHIFT BEGIN AS THE PACIFIC
NORTH AMERICAN /PNA/ TELECONNECTION BECOMES POSITIVE /WESTERN U.S.
RIDGE AND EASTERN U.S. TROUGH/. THIS WILL ALLOW MUCH COLDER AIR TO
SPILL SOUTHWARD INTO THE FORECAST AREA. UNLIKE THE 06.00Z
ECMWF WHERE IT SHOWED DECENT PRECIPITATION ASSOCIATED WITH A
CLOSED LOW...A MAJORITY OF 06.12Z NOW SUGGEST THAT THIS FRONT WILL
HAVE VERY LITTLE MOISTURE TO PRODUCE MUCH PRECIPITATION
THE TEMPERATURES BEHIND THE ARCTIC FRONT WILL BE INTI ALLY BELOW
NORMAL AND THEN WARM UP CLOSER TO NORMAL AS THE AIR MASS GRADUALLY
MODERATES. UNLIKE THE NEW YEARS FRONT...THIS COLD AIR MAY PERSIST
FOR SEVERAL INTO MID JANUARY. AS THE TROPICAL FORCING MOVES INTO
THE INDIAN OCEAN FROM THE AFRICAN CONTINENT...EXPECT TO ONCE AGAIN
SEE THE POLAR JET RETREAT BACK INTO SOUTHERN CANADA BRINGING A
RETURN TO THE UNSEASONABLE FOR THE LATTER PART OF JANUARY.
&&
.AVIATION...
1110 PM CST FRI JAN 6 2012
DIFFICULT CLOUD FORECAST FOR KRST/KLSE WITH MIXED SIGNALS IN THE
MODELS. LATEST NAM12/RUC13 DOING THE BEST JOB WITH THE CURRENT LOW
CLOUD DECK SINKING SOUTHEAST ACROSS THE REGION. IT WAS MOSTLY MVFR
WITH CIGS AROUND 2500 FT. THE RUC13 SUGGEST A GRADUAL CLEARING FROM
WEST TO EAST LATE MORNING/EARLY AFTERNOON...WHILE THE NAM HANGS ON
INTO EARLY EVENING. HOWEVER...THE NAM IS ALSO HANGING ONTO SOME SNOW
COVER WHICH IS NOT THERE...AND LIKELY LEADING TO AN OVER ABUNDANCE
OF 925 RH. HAVE OPTED TO LEAN ON THE RUC TRENDS WITH THE 06Z TAF
ISSUANCE. EXPECT THERE WILL NEED TO BE SOME UPDATES AS TIMING BECOME
MORE CLEAR.
HIGH PRESSURE WILL BUILD IN FROM THE NORTHERN PLAINS SAT NIGHT...AND
WINDS SHOULD BECOME LIGHT FROM THE SOUTH WITH SKC/SCT SKIES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
241 PM CST FRI JAN 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
427 AM EST MON JAN 9 2012
LATEST UPDATE...ALL BUT AVIATION...
.SYNOPSIS...(427 AM EST MON JAN 9 2012)
A WEAK TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE AREA TODAY
RESULTING IN AN INCREASE IN CLOUDS AND A SLIGHT CHANCE OF RAIN OR
SNOW NORTH OF M-46. COLDER WEATHER WILL RETURN THURSDAY THROUGH THE
WEEKEND. ACCUMULATING LAKE EFFECT SNOWS ARE POSSIBLE THURSDAY
THROUGH THE WEEKEND.
&&
.SHORT TERM...(427 AM EST MON JAN 9 2012)
(TODAY THROUGH WEDNESDAY)
FORECAST CONCERNS ARE MINIMAL AGAIN TODAY. A WEAK TROUGH OF LOW
PRESSURE WILL MOVE ACROSS THE REGION TODAY. REGIONAL RADAR ALREADY
SHOWS SOME LIGHT RETURNS OVER WISCONSIN MOVING SOUTHEAST. ECMWF HAS
BEEN PRETTY CONSISTENT OVER THE PAST COUPLE OF DAYS SHOWING SOME
LIGHT PCPN CLIPPING THE NRN CWA. THE SREF ALSO SUPPORTS IT. HOWEVER
THE HRRR DOESN/T. I THINK THE THREAT OF MIXED PCPN OVER THE NRN CWA
IS WORTH A SLIGHT CHC AFTER 15Z OR SO. BETWEEN M-46 AND US-10 THE
PCPN WILL LIKELY BE RAIN IF WE SEE ANYTHING AT ALL.
SOME WEAK RIDGING WILL MOVE OVER THE LAKES TONIGHT AND TUESDAY
RESULTING IN PT CLDY SKIES AND DRY WX. ANOTHER CLIPPER WILL MOVE
SOUTHEAST FROM THE NRN PLAINS TOWARD LAKE SUPERIOR WEDNESDAY AS THE
SAME TIME A SRN STREAM SYSTEM IS MOVING ENE ACROSS THE TENNESSEE
VALLEY. ATTM IT APPEARS AS THOUGH THE SRN STREAM SYSTEM WILL BE TOO
FAR SOUTH TO RESULT IN PCPN OVER THE CWA. MOST OF THE WX ASSOCIATED
WITH THE CLIPPER WILL BE POST FRONTAL AND ARRIVE EITHER VERY LATE
WEDNESDAY AFTERNOON OR WEDNESDAY EVENING. THE COLD FRONT...BRINGING
A DECENT SHOT OF ARCTIC AIR...WILL MOVE ACROSS THE CWA WEDNESDAY
AFTERNOON.
&&
.LONG TERM...(427 AM EST MON JAN 9 2012)
(WEDNESDAY NIGHT THROUGH SUNDAY)
A PERIOD OF POTENTIALLY ACTIVE WINTER WEATHER LOOKS TO BE UNFOLDING
FOR LATE THIS WEEK INTO NEXT WEEKEND. MODELS HAVE BEEN CONSISTENT IN
SHOWING A DEEP LONGWAVE TROUGH BEING CARVED OUT OVER THE GREAT LAKES
REGION... AND RECENT SOLUTIONS ARE NOW HINTING THAT IT MAY HANG
AROUND FOR SEVERAL DAYS. THIS MEANS A PERIOD OF BELOW NORMAL
TEMPERATURES AND LAKE EFFECT SNOW CAN BE EXPECTED...WHICH HAS BEEN A
RARITY SO FAR THIS WINTER.
THE COLD AIR...H8 TEMPS OF -12C TO -16C...IS STILL PROGGED TO SWEEP
IN ON THURSDAY AND WILL HAVE LIKELY POPS IN THE WRN HALF OF THE CWFA
AS LAKE EFFECT COMMENCES. HOWEVER IT/S IMPORTANT TO NOTE THAT THE
MODELS ARE HANDLING THE H5 TROUGH EVOLUTION/PROGRESSION AND
ASSOCIATED SFC PRESSURE PATTERN SOMEWHAT DIFFERENTLY.
IF THE H5 TROUGH PROGRESSION IS SLOWED DUE TO CONTINUED DIGGING
UPSTREAM... THE SFC PATTERN COULD REMAIN LOOSE AND BAGGY ON
THURSDAY. THAT COULD EASILY DELAY THE ONSET OF THE BEST COLD AIR
INTRUSION UNTIL THURSDAY NIGHT AND FRIDAY.
EXACT WIND DIRECTION AND SUBSEQUENT LOCATION/ORIENTATION OF HEAVIEST
SNOW BANDS IS ALSO A BIT UNCLEAR AT THIS TIME SINCE IT WILL DEPEND
ON THE EVENTUAL POSITION/STRENGTH OF THE SFC LOW. EXTENT OF LAKE
AGGREGATE INDUCED SFC TROUGHING WILL ALSO BE A FACTOR IN BEHAVIOR OF
THE WINDS AND SNOW BANDS. INVERSION HEIGHTS/CONVECTIVE DEPTH SHOULD
BE DEEP THURSDAY NIGHT INTO FRIDAY WITH THE UPR LOW OVERHEAD.
THERE APPEARS TO BE GROWING SUPPORT FROM NUMERICAL GUIDANCE THAT
CLIPPER DISTURBANCES DIVING DOWN FROM THE NORTHWEST WILL HELP TO
REINFORCE THE TROUGHING OVER THE GREAT LAKES REGION NEXT WEEKEND.
THIS SYNOPTIC PATTERN IMPLIES THAT ADDITIONAL...PERHAPS FREQUENT...
EPISODES OF LAKE EFFECT/ENHANCED SNOWFALLS ARE POSSIBLE.
&&
.AVIATION...(1240 AM EST MON JAN 9 2012)
LITTLE CHANGE FROM THE PREVIOUS TAFS AT 00Z. STILL EXPECTING A
PERIOD OF MVFR CEILINGS TO DEVELOP OVERNIGHT OFF OF LAKE MICHIGAN
PRIMARILY AFFECTING KGRR AND KMKG. THERE WILL LIKELY BE A PERIOD OF
SOME MVFR CEILINGS BETWEEN 14Z AND 18Z AT THE OTHER TAF SITES AS
WELL. OTHERWISE VFR CONDITIONS ARE EXPECTED.
SOUTHWEST WINDS WILL BE STRONG...IN THE 15-30 KNOT RANGE FROM 15Z TO
23Z ON MONDAY.
&&
.MARINE...(427 AM EST MON JAN 9 2012)
STARTED THE GALES A LITTLE EARLY TO AVOID DOUBLE HEADLINES. WINDS
WILL RAMP UP THIS MORNING AND HIT THEIR PEAK BY EARLY AFTERNOON.
ADDED A SCA SOUTH OF GRAND HAVEN ALSO DUE TO THE INCREASE IN WINDS
AND RESULTING HIGHER WAVES.
&&
.HYDROLOGY...(427 AM EST MON JAN 9 2012)
NO HYDRO ISSUES. COLDER AIR WILL RETURN LATER IN THE WEEK BUT WON/T
STAY AROUND LONG ENOUGH TO RESULT IN ICE BUILD UP.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING NORTH OF GRAND HAVEN TODAY.
SMALL CRAFT ADVISORY SOUTH OF GRAND HAVEN THROUGH TONIGHT.
&&
$$
SYNOPSIS: 93
SHORT TERM: 93
LONG TERM: MEADE
AVIATION: DUKE
MARINE: 93
HYDROLOGY: 93
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
436 AM EST MON JAN 9 2012
.SYNOPSIS...
WEAK DISTURBANCE BRINGS LIGHT RAIN TO MAINLY THE SOUTHERN MOUNTAINS
MONDAY. HIGH PRESSURE TUESDAY. LOW PRESSURE WEDNESDAY. COLDER AIR
ARRIVES ON THURSDAY ON GUSTY WINDS AND LASTS INTO WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
MID TO HIGH CLOUDS WILL THICKEN AND LOWERED AS A H5 WAVE APPROACHES
FROM THE WEST. MODELS QPF FIELD SUGGEST VERY LIGHT PCPN ACROSS THE
EXTREME SOUTHERN THIRD OF OUR CWA...AND ALONG THE EASTERN MOUNTAINS
THIS MORNING.
MOST PCPN WILL STRUGGLE TO REACH THE GROUND PER A DRY LOW LEVEL
LAYER...AS SEEN IN RUC BUFKIT SOUNDINGS ACROSS THE LOWLANDS.
HOWEVER...SATURATION SPREADS TOWARD THE SFC ALLOWING SOME PCPN TO
REACH THE GROUND ALONG THE MOUNTAINS. THESE PCPN WILL BE BRIEF AND
NONE OR VERY LIGHT ACCUMULATIONS CAN BE EXPECTED.
SOME OF THE COLDEST VALLEYS WILL STILL BE AROUND 31 DEGREES THROUGH
AT LEAST 9 AM.
WENT WITH A BLEND BETWEEN THE BIAS CORRECTED SOLNS OF SREF AND
WRFARW FOR HIGHS TODAY...AND WITH THE WRFARW FOR LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE DRIFTS TO THE MID ATLANTIC COAST WHILE CLOSED LOW OVER
THE DEEP SOUTH MAKES A TURN NORTHEASTWARD INTO THE APPALACHIANS.
MODELS HAVE A FAIRLY GOOD HANDLE ON THE TIMING OF THE RAIN SHIELD
ENTERING THE CWA...AND RAMP THE POPS UP QUITE QUICKLY GENERALLY
AFTER 12Z WEDNESDAY WITH WELL DEFINED FORCING IN THE FORM OF
DEFORMATION AT PLAY HERE. DID SLOW DOWN THE ONSET OF THE CLOUD COVER
FROM THE PREVIOUS FORECAST BY ABOUT 6 HOURS OR SO. CHALLENGE TO THE
FORECAST COMES WHEN THE CLOSED LOW PASSES TO THE EAST AND INTO THE
DELMARVA WHILE A STRONG COLD FRONT ADVECTS ANOTHER SIGNIFICANTLY
COLDER AIRMASS FROM THE NORTHWEST. FLOW WILL BECOME
NORTHWESTERLY...AND THE FAMILIAR UPSLOPE PATTERN BEGINS AS
TEMPERATURES DROP THROUGH THE DAY THURSDAY. THIS WILL LEAD TO A
CHANGE IN THE PRECIPITATION FROM RAIN TO SNOW...WITH THE SNOW MAINLY
COMING BEYOND THE SCOPE OF THE SHORT TERM FORECAST PERIODS. THE TWO
MAIN QUESTIONS AS OF NOW ARE WILL THERE BE A LULL IN THE
PRECIPITATION JUST AFTER FROPA...AND WHEN WILL THE TRANSITION TO
SNOW OCCUR. WILL GO AGGRESSIVE WITH THE POPS WEDNESDAY NIGHT AND
THURSDAY...AND KEEP THE PRECIPITATION TYPE CHANGE LATE THURSDAY
WHERE QPF WILL BE QUITE A BIT LOWER THAN WITH THE CLOSED LOW.
HAVE NOT TRIED TO GET TOO CUTE WITH THE TEMPERATURES WEDNESDAY
THROUGH THURSDAY. TREND IS TO MODESTLY WARM ADVECT AT FIRST WITH THE
APPROACH OF THE UPPER LEVEL SYSTEM...KEEPING TEMPERATURES ON PACE
WITH THE ABOVE NORMAL TRENDS SEEN OF LATE. THURSDAY VALUES WILL NOT
RECOVER MUCH FROM THE WEDNESDAY NIGHT LOWS WITH THE ONSET OF THE
COLD ADVECTION...AND FEEL A BLEND OF THE MOSGUIDE AND MEX WAS BEST
OUT THIS FAR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MAIN SUPPORT ALOFT STILL MOVING THROUGH WEDNESDAY EVENING. AS LIKE
24 HOURS...THE 12Z GFS RUN IS THE STRONGEST ON THE SUPPORT AND AS A
RESULT THE HEAVIEST ON ITS RAINFALL. MAY BE A MAXIMUM RAINFALL
ALONG THE OHIO RIVER COUNTIES AND ANOTHER ON THE SE UPSLOPE IN THE
CENTRAL WV MOUNTAINS. WILL LEAVE IMPACT FOR RAIN IN THE CRWRWSRLX
BUT NO HAZARD FOR FLOODING IN THE HAZARDOUS WEATHER OUTLOOK...SINCE
STILL A PROGRESSIVE SYSTEM AND LITTLE OR NO SNOW PACK LEFT.
PRECIPITABLE WATER STILL PEAKING AROUND AN INCH.
STILL THINKING THE COLDER AIR WILL BE TAKING ITS TIME MOVING IN. SO
AS YESTERDAY...KEPT MINIMUM TEMPERATURES AOA MOS GUIDANCE WEDNESDAY
NIGHT. WILL HAVE TEMPERATURES FALLING THURSDAY AFTERNOON.
LIKE 24 HOURS AGO...THE TREND TO KEPT THE COLDER AIR HERE THROUGH
THE WEEKEND STILL EXISTS. SO KEPT TEMPERATURES COLDER THAN OUR HPC
MEDIUM RANGE SUPPORT. SEVERAL SMALL DISTURBANCE AROUND THE 500 MB
TROF...OR CLOSED LOW...IN SRN GREAT LAKES INTO SATURDAY. SO THE
SNOW SHOWER ACTIVITY MAY COME AND GO FRIDAY INTO SATURDAY. HAVE KEPT
POPS HIGHER THAN GUIDANCE MAINLY CRW ON N-NE. HOWEVER...THE MID AND
LOW LEVEL FLOW MAINLY WEST AND WESTNORTHWEST IN THIS PATTERN.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS UNDER BKN100 CEILINGS TO PREVAIL AT LEAST THROUGH
15Z MONDAY...WITH THE EXCEPTION OF MVFR CEILINGS AROUND 2000 FEET
POSSIBLE ALONG CENTRAL AND EASTERN MOUNTAINS.
A MID LEVEL DISTURBANCE APPROACHING FROM THE WEST WILL AID CLOUD
DECK TO THICKEN AND LOWER INTO MVFR 1800 FEET AT BKW AND THE
SOUTHERN THIRD OF THE AREA BY THIS AFTERNOON AND EVENING.
CONDITIONS WILL IMPROVE AFTER 22Z...FOR A GRADUAL RETURN OF VFR
CONDITIONS TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: ISOLATED IFR COULD RESULT OVER THE CENTRAL
AND SOUTHERN MOUNTAINS THIS AFTERNOON AND EVENING DUE TO LOW
CHANCE RAIN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 01/09/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H M H M M M M M H M M
EKN CONSISTENCY H H H H M H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z TUESDAY...
IFR IN RAIN WED AND WED NT...AND IN RAIN AND SNOW SHOWERS THURSDAY
AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/ARJ
NEAR TERM...ARJ
SHORT TERM...26
LONG TERM...KTB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
324 AM EST MON JAN 9 2012
.SYNOPSIS...
WEAK DISTURBANCE BRINGS LIGHT RAIN TO MAINLY THE SOUTHERN MOUNTAINS
MONDAY. HIGH PRESSURE TUESDAY. LOW PRESSURE WEDNESDAY. COLDER AIR
ARRIVES ON THURSDAY ON GUSTY WINDS AND LASTS INTO WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
MID TO HIGH CLOUDS WILL THICKEN AND LOWERED AS A H5 WAVE APPROACHES
FROM THE WEST. MODELS QPF FIELD SUGGEST VERY LIGHT PCPN ACROSS THE
EXTREME SOUTHERN THIRD OF OUR CWA...AND ALONG THE EASTERN MOUNTAINS
THIS MORNING.
MOST PCPN WILL STRUGGLE TO REACH THE GROUND PER A DRY LOW LEVEL
LAYER...AS SEEN IN RUC BUFKIT SOUNDINGS ACROSS THE LOWLANDS.
HOWEVER...SATURATION SPREADS TOWARD THE SFC ALLOWING SOME PCPN TO
REACH THE GROUND ALONG THE MOUNTAINS. THESE PCPN WILL BE BRIEF AND
NONE OR VERY LIGHT ACCUMULATIONS CAN BE EXPECTED.
SOME OF THE COLDEST VALLEYS WILL STILL BE AROUND 31 DEGREES THROUGH
AT LEAST 9 AM.
WENT WITH A BLEND BETWEEN THE BIAS CORRECTED SOLNS OF SREF AND
WRFARW FOR HIGHS TODAY...AND WITH THE WRFARW FOR LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE DRIFTS TO THE MID ATLANTIC COAST WHILE CLOSED LOW OVER
THE DEEP SOUTH MAKES A TURN NORTHEASTWARD INTO THE APPALACHIANS.
MODELS HAVE A FAIRLY GOOD HANDLE ON THE TIMING OF THE RAIN SHIELD
ENTERING THE CWA...AND RAMP THE POPS UP QUITE QUICKLY GENERALLY
AFTER 12Z WEDNESDAY WITH WELL DEFINED FORCING IN THE FORM OF
DEFORMATION AT PLAY HERE. DID SLOW DOWN THE ONSET OF THE CLOUD COVER
FROM THE PREVIOUS FORECAST BY ABOUT 6 HOURS OR SO. CHALLENGE TO THE
FORECAST COMES WHEN THE CLOSED LOW PASSES TO THE EAST AND INTO THE
DELMARVA WHILE A STRONG COLD FRONT ADVECTS ANOTHER SIGNIFICANTLY
COLDER AIRMASS FROM THE NORTHWEST. FLOW WILL BECOME
NORTHWESTERLY...AND THE FAMILIAR UPSLOPE PATTERN BEGINS AS
TEMPERATURES DROP THROUGH THE DAY THURSDAY. THIS WILL LEAD TO A
CHANGE IN THE PRECIPITATION FROM RAIN TO SNOW...WITH THE SNOW MAINLY
COMING BEYOND THE SCOPE OF THE SHORT TERM FORECAST PERIODS. THE TWO
MAIN QUESTIONS AS OF NOW ARE WILL THERE BE A LULL IN THE
PRECIPITATION JUST AFTER FROPA...AND WHEN WILL THE TRANSITION TO
SNOW OCCUR. WILL GO AGGRESSIVE WITH THE POPS WEDNESDAY NIGHT AND
THURSDAY...AND KEEP THE PRECIPITATION TYPE CHANGE LATE THURSDAY
WHERE QPF WILL BE QUITE A BIT LOWER THAN WITH THE CLOSED LOW.
HAVE NOT TRIED TO GET TOO CUTE WITH THE TEMPERATURES WEDNESDAY
THROUGH THURSDAY. TREND IS TO MODESTLY WARM ADVECT AT FIRST WITH THE
APPROACH OF THE UPPER LEVEL SYSTEM...KEEPING TEMPERATURES ON PACE
WITH THE ABOVE NORMAL TRENDS SEEN OF LATE. THURSDAY VALUES WILL NOT
RECOVER MUCH FROM THE WEDNESDAY NIGHT LOWS WITH THE ONSET OF THE
COLD ADVECTION...AND FEEL A BLEND OF THE MOSGUIDE AND MEX WAS BEST
OUT THIS FAR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MAIN SUPPORT ALOFT STILL MOVING THROUGH WEDNESDAY EVENING. AS LIKE
24 HOURS...THE 12Z GFS RUN IS THE STRONGEST ON THE SUPPORT AND AS A
RESULT THE HEAVIEST ON ITS RAINFALL. MAY BE A MAXIMUM RAINFALL
ALONG THE OHIO RIVER COUNTIES AND ANOTHER ON THE SE UPSLOPE IN THE
CENTRAL WV MOUNTAINS. WILL LEAVE IMPACT FOR RAIN IN THE CRWRWSRLX
BUT NO HAZARD FOR FLOODING IN THE HAZARDOUS WEATHER OUTLOOK...SINCE
STILL A PROGRESSIVE SYSTEM AND LITTLE OR NO SNOW PACK LEFT.
PRECIPITABLE WATER STILL PEAKING AROUND AN INCH.
STILL THINKING THE COLDER AIR WILL BE TAKING ITS TIME MOVING IN. SO
AS YESTERDAY...KEPT MINIMUM TEMPERATURES AOA MOS GUIDANCE WEDNESDAY
NIGHT. WILL HAVE TEMPERATURES FALLING THURSDAY AFTERNOON.
LIKE 24 HOURS AGO...THE TREND TO KEPT THE COLDER AIR HERE THROUGH
THE WEEKEND STILL EXISTS. SO KEPT TEMPERATURES COLDER THAN OUR HPC
MEDIUM RANGE SUPPORT. SEVERAL SMALL DISTURBANCE AROUND THE 500 MB
TROF...OR CLOSED LOW...IN SRN GREAT LAKES INTO SATURDAY. SO THE
SNOW SHOWER ACTIVITY MAY COME AND GO FRIDAY INTO SATURDAY. HAVE KEPT
POPS HIGHER THAN GUIDANCE MAINLY CRW ON N-NE. HOWEVER...THE MID AND
LOW LEVEL FLOW MAINLY WEST AND WESTNORTHWEST IN THIS PATTERN.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS UNDER BKN100 CEILINGS TO PREVAIL AT LEAST THROUGH
12Z MONDAY...WITH THE EXCEPTION OF MVFR CEILINGS AROUND 2000 FEET
POSSIBLE ALONG CENTRAL AND EASTERN MOUNTAINS.
A MID LEVEL DISTURBANCE APPROACHING FROM THE WEST WILL AID CLOUD
DECK TO THICKEN AND LOWER INTO MVFR 1800 FEET AT BKW AND THE
SOUTHERN THIRD OF THE AREA MONDAY AFTERNOON AND EVENING.
CONDITIONS WILL IMPROVE AFTER 22Z...FOR A GRADUAL RETURN OF VFR
CONDITIONS MONDAY NIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: ISOLATED IFR COULD RESULT OVER THE CENTRAL
AND SOUTHERN MOUNTAINS THIS AFTERNOON AND EVENING DUE TO LOW
CHANCE RAIN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 01/09/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H M H M M M M M H M M
EKN CONSISTENCY H H H H M H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z TUESDAY...
IFR IN RAIN WED AND WED NT...AND IN RAIN AND SNOW SHOWERS THURSDAY
AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/ARJ
NEAR TERM...ARJ
SHORT TERM...26
LONG TERM...KTB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1135 PM CST SUN JAN 8 2012
.AVIATION...
WILL PREVAIL RAIN THROUGH 12Z AT METROPLEX TAF SITES. WITH INITIAL
WAVE OF CONVECTION WILL ALSO INCLUDE VCTS THROUGH 8Z...BUT
ACTIVITY SHOULD USE UP AVAILABLE INSTABILITY FOR ANY THUNDER
THEREAFTER. CIGS WILL BE MVFR INITIALLY BUT WILL LOWER TO IFR AS
LOW LEVEL SATURATION OCCURS WITH THE RAIN. VSBY OF 3-5SM WILL
PREVAIL IN RA/BR...BUT HEAVIER DOWNPOURS MAY RESULT IN BRIEF
PERIODS OF 1-2SM. EXPECT A LULL IN THE RAIN AROUND SUNRISE THROUGH
MID-LATE MORNING BEFORE NEXT WAVE ARRIVES. IN THE LULL...CIGS
SHOULD RISE TO MVFR...BUT WITH NEXT BATCH OF RAIN HAVE THEM
FALLING TO IFR AGAIN FOR MONDAY AFTERNOON AND EVENING. LIGHT RAIN
SHOULD PERSIST INTO MONDAY NIGHT.
FOR WACO NO REAL DIFFERENCE IN TIMING OF RAIN...BUT WITH GREATER
INSTABILITY WILL KEEP VCTS THROUGH 12Z. CIGS WILL BE MVFR
INITIALLY BUT SHOULD DROP TO IFR BY 8Z...AND STAY IFR THROUGH
TOMORROW EVENING. OTHERWISE EXPECT LESS RAIN COVERAGE/INTENSITY
TOMORROW EVENING WITH DRY SLOT MOVING IN FROM THE SOUTH AROUND
SUNSET.
NORTH WINDS SHOULD PREVAIL NEAR 10 KT.
TR.92
&&
.UPDATE...
OVERALL THE CURRENT FORECAST WAS ON TRACK BUT DID MAKE SOME MINOR
ADJUSTMENTS TO POPS AND TO WARM OVERNIGHT LOWS ACROSS THE REGION.
THE UPPER LEVEL LOW CAN BE SEEN ON IR AND WATER VAPOR SATELLITE
SPINNING SOUTH INTO NORTHERN MEXICO. A SURFACE LOW IS DEVELOPING
JUST AHEAD OF THE UPPER LEVEL LOW WITH A STATIONARY FRONT DRAPED
FROM NEAR DEL RIO TO NACOGDOCHES TO SHREVEPORT. THIS SURFACE FRONT
IS EXPECTED TO REMAIN NEARLY STATIONARY TONIGHT AND DEWPOINTS
ACROSS THE REGION ARE NOT EXPECTED TO CHANGE MUCH. ISENTROPIC
LIFT IS ALREADY OCCURRING WELL AHEAD OF THE UPPER LEVEL SYSTEM AND
SHOWERS AND THUNDERSTORMS ARE NOW DEVELOPING FROM EAST TEXAS BACK
TO FAR WEST TEXAS. SHOWERS AND ISOLATED THUNDERSTORMS ARE INCREASING
IN AREAL COVERAGE ACROSS NORTH TEXAS...MAINLY SOUTH OF INTERSTATE
20. EXPECT THE RAIN ACTIVITY TO CONTINUE TO INCREASE IN AREAL
COVERAGE ACROSS MUCH OF THE REGION TONIGHT. SHORT TERM MODELS SUCH
AS THE HRRR AND WRF...AND THE 00Z RUN OF THE NAM INDICATE MUCH OF
THE PRECIPITATION OVERNIGHT WILL FALL ALONG AND EAST OF
INTERSTATE 35...THUS INCREASED POPS ACROSS THE NORTHEASTERN
COUNTIES TO CATEGORICAL FOR THE OVERNIGHT HOURS. THE ONLY AREA
THAT LOOKS TO MISS ON MUCH OF THE PRECIPITATION TONIGHT IS THE FAR
NORTHWESTERN COUNTIES AND HAVE MAINTAINED 50 POPS FROM GRAHAM TO
GAINESVILLE. RADAR SIMULATIONS OF THE SHORT TERM MODELS THINK THAT
THE PRECIPITATION OVERNIGHT MAY CLEAR THE REGION TO THE EAST
AROUND DAYBREAK AND THEN THE NEXT ROUND OF RAIN WILL MOVE IN
DURING THE MONDAY MORNING HOURS...SO THERE COULD BE A BREAK IN THE
PRECIPITATION FOR A FEW HOURS MONDAY MORNING.
DUE TO EXTENSIVE AND DENSE CLOUD COVER AND NEARLY STEADY
DEWPOINTS TONIGHT...WARMED OVERNIGHT LOWS A FEW DEGREES IN
SEVERAL LOCATIONS ACROSS THE REGION. TEMPERATURES HAVE BEEN SLOW
TO FALL THIS EVENING AND MAY REMAIN NEARLY STEADY FOR MUCH OF THE
NIGHT BEFORE FALLING AROUND DAYBREAK AS THE FIRST ROUND OF RAIN
MOVES OUT AND SOME LOWER DEWPOINTS EDGE IN FROM THE NORTH.
ONE LAST QUICK NOTE ABOUT THE POTENTIAL FOR A RAIN/SNOW MIX MONDAY
NIGHT AND/OR TUESDAY...THE 00Z NAM CONTINUES TO SHOW ABOVE FREEZING
TEMPERATURES BOTH AT AND ABOVE THE SURFACE. THE 850 MB
TEMPERATURES HAVE WARMED CONSIDERABLY AND IT LOOKS LIKE MUCH OF
THE WRAP AROUND PRECIPITATION WILL OCCUR OUTSIDE OF THE REGION. AFTER
LOOKING AT ALL THE AVAILABLE MODEL DATA...HAVE PUSHED THE
RAIN/SNOW MIX LINE BACK TO JUST THE FAR WESTERN COUNTIES OF THE
CWA. WE ARE STILL NOT EXPECTING ANY IMPACTS DUE TO SNOW NOR ARE WE
EXPECTING ACCUMULATIONS.
82/JLD
&&
.PREV DISCUSSION... /ISSUED 210 PM CST SUN JAN 8 2012/
OLD FRONT IS SLOWLY SINKING SOUTHEAST THIS AFTERNOON AND IS
CURRENTLY ALIGNED ALONG A TEXARKANA...PALESTINE...COLLEGE STATION
LINE WITH TEMPERATURES IN THE LOWER-MID 60S JUST SOUTH OF THE
FRONT TO AROUND 50 DEGREES ACROSS OUR FAR NORTHWEST COUNTIES.
SKIES WERE MOSTLY CLOUDY WITH A FEW SHOWERS NOW SHOWING UP ON
REGIONAL RADAR ACROSS SOUTHEAST TEXAS WITH OUR UPPER LOW NOW
DIVING SOUTHEAST ACROSS EASTERN ARIZONA.
.SHORT TERM/EARLY HALF OF THE WEEK/...
ISENTROPIC ASCENT IN THE 295-300K LAYER WILL CONTINUE TO INCREASE
FROM SOUTH TO NORTH ACROSS THE AREA TONIGHT IN WAA REGIME WELL OUT
AHEAD OF THE UPPER LOW WELL WEST OF NORTH TEXAS. GULF OF MEXICO
WILL BE OPEN FOR BUSINESS IN DEEP SOUTHERLY FETCH OVER THE TOP OF
THE SHALLOW FRONTAL INVERSION THROUGH MONDAY WITH RAIN BECOMING
WIDESPREAD ON MONDAY. LAPSE RATES WILL CONTINUE INCREASING ALOFT
BUT WILL NOT BE OVERLY STEEP WITH A FEW EMBEDDED AREAS OF THUNDER
EXPECTED ALL THE WAY INTO MONDAY NIGHT.
THE UPPER LOW LIFTS EAST ACROSS TEXAS MONDAY NIGHT AND TUESDAY...
TRACKING SOUTH OF I-20. AS THIS OCCURS...LIFT WILL BECOME MORE
DYNAMIC AND IN THE FORM OF DPVA/FRONTOGENETICAL PROCESSES WITH
LARGER SCALE VERTICAL MOTIONS. LOW AND MID LEVEL THICKNESSES WILL
FALL TO LEVELS INDICATING A BRIEF WINDOW FOR A POSSIBLE RAIN/SNOW
MIX LATE MONDAY NIGHT/TUESDAY. FOR NOW...WE WILL ONLY MENTION THIS
POTENTIAL IN THE COLDER AIRMASS FILTERING INTO OUR FAR WESTERN
COUNTIES WHERE HIGHS WILL STRUGGLE TO REACH OVER 40 DEGREES. FEEL
TEMPERATURES FURTHER EAST WILL BE TOO WARM TO SUPPORT SNOW MAKING
IT TO THE SURFACE. HOWEVER...IF FUTURE TEMPERATURES FORECAST COME
IN COLDER...THEN A RAIN/SNOW MIX MAY NEED TO BE CARRIED FURTHER
EAST TOWARD I-35/I-35E CORRIDOR. UPPER LOW WILL DEPART EAST OVER
LOWER MISSISSIPPI VALLEY BY WEDNESDAY MORNING WITH PRECIPITATION
ENDING FROM WEST TO EAST ACROSS NORTH TEXAS.
WEDNESDAY WILL BE QUIET AND SEASONABLE UNDER FLAT UPPER RIDGE
ALOFT.
.LONG TERM/END OF THE WEEK AND NEXT WEEKEND/...
A CHILLY END OF THE WEEK IS EXPECTED AS A STRONG COLD FRONT
CHARGES SOUTHWARD THROUGH THE PLAINS AND INTO TEXAS WEDNESDAY
NIGHT AND THURSDAY. THIS FRONT WILL BE SUPPORTED BY VERY STRONG
HEIGHT FALLS ACROSS THE THE UPPER MIDWEST AND GREAT LAKES WITH AN
UPPER RIDGE STEEPENING ACROSS THE U.S WEST COAST. WE HAVE UNDERCUT
MOS HIGHS THURSDAY/FRIDAY.
MEDIUM RANGE MODELS NOW AGREEING TO KEEP BULK OF EASTERN PACIFIC
ENERGY CUT OFF NEAR THE CALIFORNIA COASTLINE WITH CONFLUENT UPPER
FLOW ACROSS CENTRAL TEXAS. THIS PATTERN GENERALLY MEANS DRY AND
COLD WEATHER. THE CUT OFF LOW WILL EVENTUALLY GET PUSHED EAST
THROUGH THE DESERT SOUTHWEST NEXT WEEKEND BY A KICKER SYSTEM IN
THE PACIFIC NORTHWEST. TEMPERATURES WILL WARM UP AHEAD OF THIS
SYSTEM AS COLD SURFACE HIGH SHIFTS OVER THE GULF COAST STATES WITH
SWLY LOW LEVEL FLOW RETURNING. THOUGH LOW RAIN CHANCES APPEAR
POSSIBLE NEXT SUNDAY/MONDAY...HAVE LEFT THE FORECAST DRY UNTIL
MOISTURE AND TIMING OF BETTER LIFT CAN BE RESOLVED.
05/
&&
.SHORT TERM/EARLY HALF OF THE WEEK/...
ISENTROPIC ASCENT IN THE 295-300K LAYER WILL CONTINUE TO INCREASE
FROM SOUTH TO NORTH ACROSS THE AREA TONIGHT IN WAA REGIME WELL OUT
AHEAD OF THE UPPER LOW WELL WEST OF NORTH TEXAS. GULF OF MEXICO
WILL BE OPEN FOR BUSINESS IN DEEP SOUTHERLY FETCH OVER THE TOP OF
THE SHALLOW FRONTAL INVERSION THROUGH MONDAY WITH RAIN BECOMING
WIDESPREAD ON MONDAY. LAPSE RATES WILL CONTINUE INCREASING ALOFT
BUT WILL NOT BE OVERLY STEEP WITH A FEW EMBEDDED AREAS OF THUNDER
EXPECTED ALL THE WAY INTO MONDAY NIGHT.
THE UPPER LOW LIFTS EAST ACROSS TEXAS MONDAY NIGHT AND TUESDAY...
TRACKING SOUTH OF I-20. AS THIS OCCURS...LIFT WILL BECOME MORE
DYNAMIC AND IN THE FORM OF DPVA/FRONTOGENETICAL PROCESSES WITH
LARGER SCALE VERTICAL MOTIONS. LOW AND MID LEVEL THICKNESSES WILL
FALL TO LEVELS INDICATING A BRIEF WINDOW FOR A POSSIBLE RAIN/SNOW
MIX LATE MONDAY NIGHT/TUESDAY. FOR NOW...WE WILL ONLY MENTION THIS
POTENTIAL IN THE COLDER AIRMASS FILTERING INTO OUR FAR WESTERN
COUNTIES WHERE HIGHS WILL STRUGGLE TO REACH OVER 40 DEGREES. FEEL
TEMPERATURES FURTHER EAST WILL BE TOO WARM TO SUPPORT SNOW MAKING
IT TO THE SURFACE. HOWEVER...IF FUTURE TEMPERATURES FORECAST COME
IN COLDER...THEN A RAIN/SNOW MIX MAY NEED TO BE CARRIED FURTHER
EAST TOWARD I-35/I-35E CORRIDOR. UPPER LOW WILL DEPART EAST OVER
LOWER MISSISSIPPI VALLEY BY WEDNESDAY MORNING WITH PRECIPITATION
ENDING FROM WEST TO EAST ACROSS NORTH TEXAS.
WEDNESDAY WILL BE QUIET AND SEASONABLE UNDER FLAT UPPER RIDGE
ALOFT.
.LONG TERM/END OF THE WEEK AND NEXT WEEKEND/...
A CHILLY END OF THE WEEK IS EXPECTED AS A STRONG COLD FRONT
CHARGES SOUTHWARD THROUGH THE PLAINS AND INTO TEXAS WEDNESDAY
NIGHT AND THURSDAY. THIS FRONT WILL BE SUPPORTED BY VERY STRONG
HEIGHT FALLS ACROSS THE THE UPPER MIDWEST AND GREAT LAKES WITH AN
UPPER RIDGE STEEPENING ACROSS THE U.S WEST COAST. WE HAVE UNDERCUT
MOS HIGHS THURSDAY/FRIDAY.
MEDIUM RANGE MODELS NOW AGREEING TO KEEP BULK OF EASTERN PACIFIC
ENERGY CUT OFF NEAR THE CALIFORNIA COASTLINE WITH CONFLUENT UPPER
FLOW ACROSS CENTRAL TEXAS. THIS PATTERN GENERALLY MEANS DRY AND
COLD WEATHER. THE CUT OFF LOW WILL EVENTUALLY GET PUSHED EAST
THROUGH THE DESERT SOUTHWEST NEXT WEEKEND BY A KICKER SYSTEM IN
THE PACIFIC NORTHWEST. TEMPERATURES WILL WARM UP AHEAD OF THIS
SYSTEM AS COLD SURFACE HIGH SHIFTS OVER THE GULF COAST STATES WITH
SWLY LOW LEVEL FLOW RETURNING. THOUGH LOW RAIN CHANCES APPEAR
POSSIBLE NEXT SUNDAY/MONDAY...HAVE LEFT THE FORECAST DRY UNTIL
MOISTURE AND TIMING OF BETTER LIFT CAN BE RESOLVED.
05/
&&
.LONG TERM/END OF THE WEEK AND NEXT WEEKEND/...
A CHILLY END OF THE WEEK IS EXPECTED AS A STRONG COLD FRONT
CHARGES SOUTHWARD THROUGH THE PLAINS AND INTO TEXAS WEDNESDAY
NIGHT AND THURSDAY. THIS FRONT WILL BE SUPPORTED BY VERY STRONG
HEIGHT FALLS ACROSS THE THE UPPER MIDWEST AND GREAT LAKES WITH AN
UPPER RIDGE STEEPENING ACROSS THE U.S WEST COAST. WE HAVE UNDERCUT
MOS HIGHS THURSDAY/FRIDAY.
MEDIUM RANGE MODELS NOW AGREEING TO KEEP BULK OF EASTERN PACIFIC
ENERGY CUT OFF NEAR THE CALIFORNIA COASTLINE WITH CONFLUENT UPPER
FLOW ACROSS CENTRAL TEXAS. THIS PATTERN GENERALLY MEANS DRY AND
COLD WEATHER. THE CUT OFF LOW WILL EVENTUALLY GET PUSHED EAST
THROUGH THE DESERT SOUTHWEST NEXT WEEKEND BY A KICKER SYSTEM IN
THE PACIFIC NORTHWEST. TEMPERATURES WILL WARM UP AHEAD OF THIS
SYSTEM AS COLD SURFACE HIGH SHIFTS OVER THE GULF COAST STATES WITH
SWLY LOW LEVEL FLOW RETURNING. THOUGH LOW RAIN CHANCES APPEAR
POSSIBLE NEXT SUNDAY/MONDAY...HAVE LEFT THE FORECAST DRY UNTIL
MOISTURE AND TIMING OF BETTER LIFT CAN BE RESOLVED.
05/
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 44 48 40 45 36 / 90 100 100 60 10
WACO, TX 49 50 37 49 34 / 100 100 90 30 10
PARIS, TX 45 51 46 49 38 / 80 80 90 80 30
DENTON, TX 42 48 39 45 34 / 80 90 100 60 10
MCKINNEY, TX 43 49 42 45 35 / 80 90 100 70 20
DALLAS, TX 45 50 42 45 37 / 90 100 100 60 20
TERRELL, TX 45 52 43 48 36 / 90 100 100 60 20
CORSICANA, TX 50 57 41 48 36 / 100 100 100 50 20
TEMPLE, TX 50 50 39 52 34 / 100 100 80 20 5
MINERAL WELLS, TX 40 45 36 43 32 / 70 90 90 40 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
215 AM CST MON JAN 9 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
215 AM CST MON JAN 9 2012
MAIN FORECAST CONCERNS ARE ON TEMPERATURES THROUGH TUESDAY NIGHT...
THEN THE COOL DOWN AND PRECIPITATION CHANCES FOR MIDWEEK.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING FROM CALIFORNIA INTO SOUTHERN ALBERTA...A CUT-OFF
UPPER LOW OVER NORTHERN MEXICO...BROAD TROUGHING OVER SOUTHEAST
CANADA INTO THE GREAT LAKES...AND A SHORTWAVE OVER NORTHERN
MINNESOTA. THIS SHORTWAVE IS PRODUCING AN AREA OF MID AND HIGH
CLOUDS ACROSS MUCH OF MINNESOTA INTO NORTHERN WISCONSIN...AS WELL
AS A TIGHTER SURFACE PRESSURE GRADIENT. 925MB RUC AND VAD WIND
PROFILE DATA REFLECT THE INCREASING PRESSURE GRADIENT...WITH
SOUTHWEST WINDS OF 40-45KT ACROSS MUCH OF MINNESOTA. THESE WINDS
ARE ADVECTING WARMER AIR EASTWARD...NOTED BY A 1-3C INCREASE IN
925MB TEMPS AT MPX...ABR AND BIS BETWEEN 12Z YESTERDAY AND 00Z
TODAY PER RAOB DATA. 00Z DATA NOW SHOW READINGS BETWEEN
1-3C...HIGHEST AT BIS. SURFACE TEMPERATURES HAVE RESPONDED TO THE
INCREASING WINDS...CLOUDS AND WARM ADVECTION BY MOSTLY STAYING IN
THE 20S TO LOW 30S. AIRMASS REMAINS DRY AS WELL OVER THE UPPER
MIDWEST WITH 10C OR HIGHER DEWPOINT DEPRESSIONS BELOW 600MB ON THE
00Z BIS...ABR AND MPX SOUNDINGS.
TODAY AND TONIGHT...SHORTWAVE OVER NORTHERN MINNESOTA IS FORECAST TO
DIVE SOUTHEAST INTO LOWER MICHIGAN BY 00Z. IN ITS WAKE...500MB
HEIGHTS ARE EXPECTED TO GRADUALLY RISE OVER THE FORECAST AREA. THESE
HEIGHT RISES SHOULD CONTINUE THROUGH TONIGHT...AND THESE ARE IN
RESPONSE TO A POTENT TROUGH DEVELOPING OVER SOUTHWEST CANADA.
SUBSIDENCE ASSOCIATED WITH THE HEIGHT RISES...IN COMBINATION WITH
ALL THE DRY AIR PRESENT OVER THE AREA...WILL RESULT IN CONTINUED DRY
CONDITIONS. THE HEIGHT RISES ALSO MEAN CONTINUED WARM ADVECTION...
REFLECTED BY 925MB TEMPS CLIMBING TO 0-2C BY 18Z TODAY. THESE ARE
AROUND 2C HIGHER THAN YESTERDAY AT 18Z. SUNSHINE MAY BE SOMEWHAT
LIMITED INITIALLY THIS MORNING BY THE MID AND HIGH CLOUDS...BUT
THESE SHOULD CLEAR IN THE AFTERNOON AS THE SHORTWAVE MOVES AWAY FROM
THE AREA. IT DOES TO LOOK TO STAY BREEZY THIS MORNING WITH THE
PRESSURE GRADIENT FAIRLY TIGHT...AS WELL AS THAT 925MB WIND CORE
COMING ACROSS. THE WINDS SHOULD DIMINISH IN THE AFTERNOON...ALSO DUE
TO THE SHORTWAVE MOVING AWAY FROM THE AREA AND A WEAK SURFACE RIDGE
DEVELOPING OVER MINNESOTA. ALL IN ALL WE SHOULD END UP WITH PLENTY
OF MIXING...FROM THE WINDS THIS MORNING AND SUN IN THE AFTERNOON...
ALLOWING TEMPERATURES TO CLIMB WELL INTO THE 40S FOR MOST LOCATIONS.
THE SURFACE RIDGE MOVES OVER THE AREA TONIGHT...AND WITH ONLY SOME
SCATTERED MID CLOUDS POSSIBLE...ANTICIPATING TEMPERATURES TO FALL
OFF INTO THE 20S TO LOW 30S. THIS IS DESPITE SOME 925MB WARMING
WHICH REACHES 2-5C BY 12Z.
TUESDAY AND TUESDAY NIGHT...MODELS ARE IN GOOD AGREEMENT DIGGING THE
POTENT UPPER TROUGH SOUTHEAST INTO EASTERN MONTANA AND NORTH DAKOTA
BY 12Z WEDNESDAY. AS THIS UPPER TROUGH DIGS SOUTHEAST...A COLD FRONT
WELL OUT AHEAD OF IT SHOULD MOVE INTO AND PERHAPS THROUGH THE
FORECAST AREA BETWEEN 06-12Z WEDNESDAY. NOT ANTICIPATING ANY
PRECIPITATION ON OR AHEAD OF THE FRONT DUE TO AGAIN THE DRY AIRMASS.
EVEN BEHIND THE FRONT...ANY PRECIPITATION LOOKS TO STAY A LITTLE
FARTHER WEST...CLOSER TO THE DPVA FORCING WITH THE UPPER TROUGH AND
MID-LEVEL FRONTOGENESIS. SO PERHAPS BY 12Z...SOME PRECIPITATION
COULD BE APPROACHING I-35 AND FAR NORTHWEST WI...ASSUMING THE
ATMOSPHERE CAN SATURATE. FOR OUR AREA...MAIN CONCERN IS THE WARMING
OCCURRING AHEAD OF THE FRONT. 925MB TEMPS CLIMB A LITTLE FURTHER ON
TUESDAY TO 3-6C BY 18Z. OTHER THAN MAYBE FOR A FEW MID OR HIGH
CLOUDS AT BEST...SHOULD SEE MOSTLY SUNNY SKIES. WINDS PICK UP TOO
WITH THE DIGGING OF THE UPPER TROUGH...ALBEIT ONLY 5 TO 15 KT.
STILL...IT IS OUT OF A FAVORABLE SOUTHWEST DIRECTION. SO ALL SIGNS
POINT TO GOOD MIXING ON TUESDAY. HIGHS SHOULD EASILY CLIMB WELL INTO
THE 40S WITH LOW 50S LIKELY TOO. COOLING SHOULD OCCUR GRADUALLY
TUESDAY EVENING...THEN PERHAPS PICK UP SOME AFTER MIDNIGHT WITH
THE COLD FRONTAL PASSAGE. ON THE OTHER HAND...THE WINDS BEHIND THE
FRONT ADVECTING IN COLDER AIR MAY ALSO HELP TO KEEP THE ATMOSPHERE
MIXED. THEREFORE...HAVE FOLLOWED A BLEND OF GUIDANCE FOR LOWS.
WEDNESDAY AND WEDNESDAY NIGHT...SOME DIFFERENCES BEGIN TO SHOW UP
WITH THE HANDLING OF THE POTENT UPPER TROUGH. THE 09.00Z GFS/NAM AND
08.12Z/09.00Z ECMWF SHOW THE UPPER TROUGH MOVING OVER MUCH OF
MINNESOTA BY 00Z THURSDAY AND OVER MUCH OF THE FORECAST AREA BY 12Z
THURSDAY. WITHIN THIS GROUP...THE ECMWF SHOWS AN UPPER LOW IN
SOUTHERN MINNESOTA WHEREAS THE GFS/NAM PLACE IT IN WESTERN UPPER
MICHIGAN. THE 09.00Z UKMET/CANADIAN ON THE OTHER HAND HAVE A SLOWER
UPPER TROUGH...KEEPING IT STILL IN THE DAKOTAS AT 00Z THURSDAY...
THEN MOVING INTO MINNESOTA POSITIVELY TILTED BY 12Z THURSDAY AND NO
UPPER LOW CENTER. HPC PMDHMD PRODUCT DETAILS A LOT OF ISSUES WITH
THE 08.12Z/09.00Z ECMWF...09.00Z GFS AND NAM REGARDING THIS
TROUGH... SAYING THEY ARE ALL TOO AMPLIFIED AND FAST. A PREFERENCE
IS FOR A SLOWER SOLUTION...WHICH WOULD MATCH THE TREND SEEN WITH THE
08.00Z MODELS. THE SPEED OF THE TROUGH HAS BIG IMPACTS ON
WEDNESDAYS HIGHS...SINCE THE COLD AIR WOULD FLOW IN FASTER IN THE
08.12Z AND ESPECIALLY 09.00Z GFS/NAM SCENARIOS. EITHER WAY...THE
COLD AIR WILL EVENTUALLY FLOW INTO THE FORECAST AREA...WITH ALL
MODELS SHOWING 850MB TEMPS TANKING TO -16 TO -20C BY 12Z THURSDAY.
UNTIL MODELS RESOLVE THE TIMING...HAVE LEFT THE TEMPERATURE
FORECASTS MOSTLY ALONE...KEEPING TOO THAT FALLING TEMPERATURE TREND
WEDNESDAY AFTERNOON SINCE EVEN THE SLOWER SOLUTIONS WOULD SUGGEST
THAT. PRECIPITATION IS LOOKING HARDER AND HARDER TO COME BY WITH
THIS UPPER TROUGH. CERTAINLY THE DYNAMICS LOOK IMPRESSIVE...EVEN
WITH THE POSITIVELY TILTED SOLUTIONS WHICH HAVE ANYWHERE FROM 60-100
METER HEIGHT FALLS AT 500MB FOR WEDNESDAY AND AGAIN WEDNESDAY NIGHT.
HOWEVER...THE MOISTURE IS VERY LIMITED...DUE TO THE DRY AIRMASS
AHEAD OF THE TROUGH AND GULF OF MEXICO MOISTURE CUT-OFF FROM AN
UPPER LOW RIDING THROUGH THERE. MODELS AT BEST SHOW A COUPLE OF
HUNDREDTHS OF QPF COMING THROUGH THE FORECAST AREA...AND THAT IS
MOSTLY ON WEDNESDAY. THEREFORE...HAVE KEPT PRECIPITATION CHANCES IN
THE 20-50 RANGE FOR NOW.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
215 AM CST MON JAN 9 2012
09.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES AGREE IN GENERAL WITH
THE MEAN UPPER LEVEL PATTERN THROUGHOUT THE EXTENDED...WHICH
FEATURES MOSTLY TROUGHING OVER THE CENTRAL AND EASTERN U.S.. MOST OF
THIS TROUGHING STARTS FROM THAT POTENT TROUGH DROPPING DOWN INTO THE
FORECAST AREA WEDNESDAY NIGHT. THE TROUGHING THEN GETS REINFORCED BY
A SHORTWAVE DROPPING SOUTH THROUGH THE UPPER MIDWEST FRIDAY
NIGHT...PERHAPS CROSSING THE FORECAST AREA ON SATURDAY ACCORDING TO
SOME MODEL SOLUTIONS. THERE ARE INDICATIONS THAT RIDGING WILL BUILD
TOWARDS THE AREA ON SUNDAY DUE TO TROUGHING DROPPING DOWN INTO
BRITISH COLUMBIA AND WASHINGTON STATE.
THURSDAY THROUGH FRIDAY ARE LIKELY TO BE QUITE CHILLY...COMPARED TO
WHAT WE HAVE SEEN RECENTLY...WITH 850MB TEMPS DROPPING TO AROUND
-20C BY 00Z FRIDAY. MOSTLY CLOUDY SKIES WILL ALSO LIMIT DIURNAL
HEATING...THOUGH AT THE SAME TIME HELP TEMPERATURES FROM TANKING
THURSDAY NIGHT. SOME SLOW MODERATION IS ANTICIPATED FOR FRIDAY AS
THE CORE OF THE COLD AIR LIFTS OUT TO THE NORTHEAST...BUT STILL
READINGS SHOULD STAY BELOW NORMAL. THE SLOW MODERATION CONTINUES
THROUGH THE WEEKEND...ESPECIALLY ON SUNDAY WHEN THE RIDGING STARTS
BUILDING IN. THROUGHOUT THE LONG TERM PERIOD...FOLLOWED A CONSENSUS
OF GUIDANCE FOR TEMPERATURES.
PRECIPITATION CHANCES LOOKS PRETTY SLIM DUE TO AGAIN A LACK OF
MOISTURE. 09.00Z ECMWF HINTING THAT THERE COULD BE A LITTLE LIGHT
SNOW THURSDAY NIGHT WRAPPING AROUND...BUT IT IS THE ONLY MODEL
SHOWING IT. PLUS...WITH THE CONCERN MENTIONED IN THE WEDNESDAY
DISCUSSION ABOVE ABOUT THE ECMWF...NOT READY TO JUMP ON PUTTING
PRECIPITATION CHANCES IN FOR THURSDAY NIGHT. NEXT POTENTIAL TIME
PERIOD FOR PRECIPITATION CHANCES WOULD COME SATURDAY WITH THE
SHORTWAVE COMING THROUGH. HOWEVER...MODELS HAVE BEEN FAR FROM
CONSISTENT ON THE TRACK OF THIS SHORTWAVE...AND SOME HAVE IT GOING
NORTH AND SOUTH OF THE AREA FOR THIS 09.00Z CYCLE. THEREFORE...HAVE
MAINTAINED SATURDAY DRY TOO. THIS RESULTS IN THE ENTIRE LONG TERM
FORECAST DRY FOR NOW.
&&
.AVIATION...
1110 PM CST SUN JAN 8 2012
HIGH/MID LEVEL CLOUDS WILL BE ON THE INCREASE OVERNIGHT AS AN UPPER
LEVEL SHORTWAVE TROUGH DROPS SOUTHEAST ACROSS THE REGION. THE SFC
PRESSURE GRADIENT WILL ALSO TIGHTEN...WITH A SFC TROUGH SHIFTING THE
WINDS TO A MORE WESTERLY DIRECTION AROUND 18Z MON. BUFKIT SOUNDINGS
SUGGEST MIXING UP TO 1 KFT ON MONDAY...BUT THIS SHOULD BE ENOUGH FOR
GUSTY LATE MORNING/AFTERNOON CONDITIONS. SLACKENING PRESSURE
GRADIENT POST THE DEPARTING SHORTWAVE MONDAY NIGHT WILL RESULT IN
DECREASING WINDS...AND A SHIFT TO THE SOUTH/SOUTHWEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
215 AM CST MON JAN 9 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION....RIECK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
715 AM EST MON JAN 9 2012
LATEST UPDATE...AVIATION...
.SYNOPSIS...(427 AM EST MON JAN 9 2012)
A WEAK TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE AREA TODAY
RESULTING IN AN INCREASE IN CLOUDS AND A SLIGHT CHANCE OF RAIN OR
SNOW NORTH OF M-46. COLDER WEATHER WILL RETURN THURSDAY THROUGH THE
WEEKEND. ACCUMULATING LAKE EFFECT SNOWS ARE POSSIBLE THURSDAY
THROUGH THE WEEKEND.
&&
.SHORT TERM...(427 AM EST MON JAN 9 2012)
(TODAY THROUGH WEDNESDAY)
FORECAST CONCERNS ARE MINIMAL AGAIN TODAY. A WEAK TROUGH OF LOW
PRESSURE WILL MOVE ACROSS THE REGION TODAY. REGIONAL RADAR ALREADY
SHOWS SOME LIGHT RETURNS OVER WISCONSIN MOVING SOUTHEAST. ECMWF HAS
BEEN PRETTY CONSISTENT OVER THE PAST COUPLE OF DAYS SHOWING SOME
LIGHT PCPN CLIPPING THE NRN CWA. THE SREF ALSO SUPPORTS IT. HOWEVER
THE HRRR DOESN/T. I THINK THE THREAT OF MIXED PCPN OVER THE NRN CWA
IS WORTH A SLIGHT CHC AFTER 15Z OR SO. BETWEEN M-46 AND US-10 THE
PCPN WILL LIKELY BE RAIN IF WE SEE ANYTHING AT ALL.
SOME WEAK RIDGING WILL MOVE OVER THE LAKES TONIGHT AND TUESDAY
RESULTING IN PT CLDY SKIES AND DRY WX. ANOTHER CLIPPER WILL MOVE
SOUTHEAST FROM THE NRN PLAINS TOWARD LAKE SUPERIOR WEDNESDAY AS THE
SAME TIME A SRN STREAM SYSTEM IS MOVING ENE ACROSS THE TENNESSEE
VALLEY. ATTM IT APPEARS AS THOUGH THE SRN STREAM SYSTEM WILL BE TOO
FAR SOUTH TO RESULT IN PCPN OVER THE CWA. MOST OF THE WX ASSOCIATED
WITH THE CLIPPER WILL BE POST FRONTAL AND ARRIVE EITHER VERY LATE
WEDNESDAY AFTERNOON OR WEDNESDAY EVENING. THE COLD FRONT...BRINGING
A DECENT SHOT OF ARCTIC AIR...WILL MOVE ACROSS THE CWA WEDNESDAY
AFTERNOON.
&&
.LONG TERM...(427 AM EST MON JAN 9 2012)
(WEDNESDAY NIGHT THROUGH SUNDAY)
A PERIOD OF POTENTIALLY ACTIVE WINTER WEATHER LOOKS TO BE UNFOLDING
FOR LATE THIS WEEK INTO NEXT WEEKEND. MODELS HAVE BEEN CONSISTENT IN
SHOWING A DEEP LONGWAVE TROUGH BEING CARVED OUT OVER THE GREAT LAKES
REGION... AND RECENT SOLUTIONS ARE NOW HINTING THAT IT MAY HANG
AROUND FOR SEVERAL DAYS. THIS MEANS A PERIOD OF BELOW NORMAL
TEMPERATURES AND LAKE EFFECT SNOW CAN BE EXPECTED...WHICH HAS BEEN A
RARITY SO FAR THIS WINTER.
THE COLD AIR...H8 TEMPS OF -12C TO -16C...IS STILL PROGGED TO SWEEP
IN ON THURSDAY AND WILL HAVE LIKELY POPS IN THE WRN HALF OF THE CWFA
AS LAKE EFFECT COMMENCES. HOWEVER IT/S IMPORTANT TO NOTE THAT THE
MODELS ARE HANDLING THE H5 TROUGH EVOLUTION/PROGRESSION AND
ASSOCIATED SFC PRESSURE PATTERN SOMEWHAT DIFFERENTLY.
IF THE H5 TROUGH PROGRESSION IS SLOWED DUE TO CONTINUED DIGGING
UPSTREAM... THE SFC PATTERN COULD REMAIN LOOSE AND BAGGY ON
THURSDAY. THAT COULD EASILY DELAY THE ONSET OF THE BEST COLD AIR
INTRUSION UNTIL THURSDAY NIGHT AND FRIDAY.
EXACT WIND DIRECTION AND SUBSEQUENT LOCATION/ORIENTATION OF HEAVIEST
SNOW BANDS IS ALSO A BIT UNCLEAR AT THIS TIME SINCE IT WILL DEPEND
ON THE EVENTUAL POSITION/STRENGTH OF THE SFC LOW. EXTENT OF LAKE
AGGREGATE INDUCED SFC TROUGHING WILL ALSO BE A FACTOR IN BEHAVIOR OF
THE WINDS AND SNOW BANDS. INVERSION HEIGHTS/CONVECTIVE DEPTH SHOULD
BE DEEP THURSDAY NIGHT INTO FRIDAY WITH THE UPR LOW OVERHEAD.
THERE APPEARS TO BE GROWING SUPPORT FROM NUMERICAL GUIDANCE THAT
CLIPPER DISTURBANCES DIVING DOWN FROM THE NORTHWEST WILL HELP TO
REINFORCE THE TROUGHING OVER THE GREAT LAKES REGION NEXT WEEKEND.
THIS SYNOPTIC PATTERN IMPLIES THAT ADDITIONAL...PERHAPS FREQUENT...
EPISODES OF LAKE EFFECT/ENHANCED SNOWFALLS ARE POSSIBLE.
&&
.AVIATION...(715 AM EST MON JAN 9 2012)
SOME MVFR CIGS HAVE BEEN MOVING IN OFF LAKE MICHIGAN EARLY THIS
MORNING... BUT COVERAGE HAS BEEN PRIMARILY LIMITED TO SCATTERED.
SOME BKN MVFR CIGS ARE STILL POSSIBLE THROUGH NOON BEFORE THE
STRONGER WARM ADVECTION INITIATES THIS AFTERNOON. OTHERWISE VFR IS
EXPECTED TODAY AND TONIGHT. ANY LIGHT PCPN WITH THE APCHG TROUGH
SHOULD STAY NORTH OF THE SRN MI TAF SITES.
THE MAIN AVIATION ISSUE TODAY WILL BE THE SOUTHWEST SFC WINDS WHICH
ARE EXPECTED TO BECOME STRONG AND GUSTY AFTER 15Z OR SO. THOSE WINDS
WILL DECREASE TONIGHT AFTER 00Z.
&&
.MARINE...(427 AM EST MON JAN 9 2012)
STARTED THE GALES A LITTLE EARLY TO AVOID DOUBLE HEADLINES. WINDS
WILL RAMP UP THIS MORNING AND HIT THEIR PEAK BY EARLY AFTERNOON.
ADDED A SCA SOUTH OF GRAND HAVEN ALSO DUE TO THE INCREASE IN WINDS
AND RESULTING HIGHER WAVES.
&&
.HYDROLOGY...(427 AM EST MON JAN 9 2012)
NO HYDRO ISSUES. COLDER AIR WILL RETURN LATER IN THE WEEK BUT WON/T
STAY AROUND LONG ENOUGH TO RESULT IN ICE BUILD UP.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING NORTH OF GRAND HAVEN TODAY.
SMALL CRAFT ADVISORY SOUTH OF GRAND HAVEN THROUGH TONIGHT.
&&
$$
SYNOPSIS: 93
SHORT TERM: 93
LONG TERM: MEADE
AVIATION: MEADE
MARINE: 93
HYDROLOGY: 93
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1034 AM EST MON JAN 9 2012
.SYNOPSIS...
WEAK DISTURBANCE BRINGS LIGHT RAIN TO MAINLY THE SOUTHERN MOUNTAINS
MONDAY. HIGH PRESSURE TUESDAY. LOW PRESSURE WEDNESDAY. COLDER AIR
ARRIVES ON THURSDAY ON GUSTY WINDS AND LASTS INTO WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...UPDATED
CALLS OUT TO MTN COUNTIES THIS MORNING REVEALED -RA FALLING ACROSS
SOME OF THE SUSPECT AREAS...IE EASTERN RALEIGH...FAYETTE. -SN WAS
FALLING IN POCAHONTAS. RUC SEEMS TO SHOW THIS SHARP BOUNDARY TO
DEEPER COLD AIR AND USED THIS AND CURRENT OBS TO BASE UPDATED FCST
ON. CURRENT SFC TMPS RUNNING 29-30F ACROSS POCAHONTAS AND EASTERN
RANDOLPH.
A MORE SUBSTANTIAL AREA OF PCPN NOTED ACROSS EASTERN KY...NOW
SLIDING E INTO SOUTHERN WV. THIS IS IN ASSOCIATION WITH SOME
INCREASED ISENTROPIC LIFT WITH WAVE PASSING THRU. HAVE THIS TIMED
TO REACH CENTRAL MTNS 16-17Z. RUC SOUNDINGS INDICATED ENOUGH
WARMING ALOFT BY THIS TIME TO TRANSITION ANY SN OVER TO MORE OF A
FRZ RAIN AND SLEET SCENARIO ACROSS GREENBRIER VALLEY...WITH A COLD
RAIN PERHAPS ON THE RIDGE TOPS. WHERE THE COLDER AIR IS DEEPER
ACROSS RANDOLPH...THINK PCPN WILL STRUGGLE TO REACH THE GROUND AS
DEEPER MOISTURE LIES JUST TO SOUTH. GIVEN THIS...WILL EXTEND TIME
OF ADV UNTIL 18Z FOR POCAHONTAS AND LET WEBSTER AND RANDOLPH
EXPIRE. WILL ALLOW FOR UP TO AN INCH OF SN IN POCAHONTAS BEFORE
THE TRANSITION AND A HUNDRETH OR TWO OF ICE WITH SOME SLEET 16-18Z.
ELSEWHERE...SOME -RA OVER THE COAL FIELDS AND SOUTHERN MTNS WITH
MAYBE A FEW SLEET PELLETS THROWN IN. KEEPING IT DRY NORTH OF I64
CORRIDOR OVER THE LOWLANDS.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE DRIFTS TO THE MID ATLANTIC COAST WHILE CLOSED LOW OVER
THE DEEP SOUTH MAKES A TURN NORTHEASTWARD INTO THE APPALACHIANS.
MODELS HAVE A FAIRLY GOOD HANDLE ON THE TIMING OF THE RAIN SHIELD
ENTERING THE CWA...AND RAMP THE POPS UP QUITE QUICKLY GENERALLY
AFTER 12Z WEDNESDAY WITH WELL DEFINED FORCING IN THE FORM OF
DEFORMATION AT PLAY HERE. DID SLOW DOWN THE ONSET OF THE CLOUD COVER
FROM THE PREVIOUS FORECAST BY ABOUT 6 HOURS OR SO. CHALLENGE TO THE
FORECAST COMES WHEN THE CLOSED LOW PASSES TO THE EAST AND INTO THE
DELMARVA WHILE A STRONG COLD FRONT ADVECTS ANOTHER SIGNIFICANTLY
COLDER AIRMASS FROM THE NORTHWEST. FLOW WILL BECOME
NORTHWESTERLY...AND THE FAMILIAR UPSLOPE PATTERN BEGINS AS
TEMPERATURES DROP THROUGH THE DAY THURSDAY. THIS WILL LEAD TO A
CHANGE IN THE PRECIPITATION FROM RAIN TO SNOW...WITH THE SNOW MAINLY
COMING BEYOND THE SCOPE OF THE SHORT TERM FORECAST PERIODS. THE TWO
MAIN QUESTIONS AS OF NOW ARE WILL THERE BE A LULL IN THE
PRECIPITATION JUST AFTER FROPA...AND WHEN WILL THE TRANSITION TO
SNOW OCCUR. WILL GO AGGRESSIVE WITH THE POPS WEDNESDAY NIGHT AND
THURSDAY...AND KEEP THE PRECIPITATION TYPE CHANGE LATE THURSDAY
WHERE QPF WILL BE QUITE A BIT LOWER THAN WITH THE CLOSED LOW.
HAVE NOT TRIED TO GET TOO CUTE WITH THE TEMPERATURES WEDNESDAY
THROUGH THURSDAY. TREND IS TO MODESTLY WARM ADVECT AT FIRST WITH THE
APPROACH OF THE UPPER LEVEL SYSTEM...KEEPING TEMPERATURES ON PACE
WITH THE ABOVE NORMAL TRENDS SEEN OF LATE. THURSDAY VALUES WILL NOT
RECOVER MUCH FROM THE WEDNESDAY NIGHT LOWS WITH THE ONSET OF THE
COLD ADVECTION...AND FEEL A BLEND OF THE MOSGUIDE AND MEX WAS BEST
OUT THIS FAR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MAIN SUPPORT ALOFT STILL MOVING THROUGH WEDNESDAY EVENING. AS LIKE
24 HOURS...THE 12Z GFS RUN IS THE STRONGEST ON THE SUPPORT AND AS A
RESULT THE HEAVIEST ON ITS RAINFALL. MAY BE A MAXIMUM RAINFALL
ALONG THE OHIO RIVER COUNTIES AND ANOTHER ON THE SE UPSLOPE IN THE
CENTRAL WV MOUNTAINS. WILL LEAVE IMPACT FOR RAIN IN THE CRWRWSRLX
BUT NO HAZARD FOR FLOODING IN THE HAZARDOUS WEATHER OUTLOOK...SINCE
STILL A PROGRESSIVE SYSTEM AND LITTLE OR NO SNOW PACK LEFT.
PRECIPITABLE WATER STILL PEAKING AROUND AN INCH.
STILL THINKING THE COLDER AIR WILL BE TAKING ITS TIME MOVING IN. SO
AS YESTERDAY...KEPT MINIMUM TEMPERATURES AOA MOS GUIDANCE WEDNESDAY
NIGHT. WILL HAVE TEMPERATURES FALLING THURSDAY AFTERNOON.
LIKE 24 HOURS AGO...THE TREND TO KEPT THE COLDER AIR HERE THROUGH
THE WEEKEND STILL EXISTS. SO KEPT TEMPERATURES COLDER THAN OUR HPC
MEDIUM RANGE SUPPORT. SEVERAL SMALL DISTURBANCE AROUND THE 500 MB
TROF...OR CLOSED LOW...IN SRN GREAT LAKES INTO SATURDAY. SO THE
SNOW SHOWER ACTIVITY MAY COME AND GO FRIDAY INTO SATURDAY. HAVE KEPT
POPS HIGHER THAN GUIDANCE MAINLY CRW ON N-NE. HOWEVER...THE MID AND
LOW LEVEL FLOW MAINLY WEST AND WESTNORTHWEST IN THIS PATTERN.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS UNDER BKN100 CEILINGS TO PREVAIL AT LEAST THROUGH
15Z MONDAY...WITH THE EXCEPTION OF MVFR CEILINGS AROUND 2000 FEET
POSSIBLE ALONG CENTRAL AND EASTERN MOUNTAINS.
A MID LEVEL DISTURBANCE APPROACHING FROM THE WEST WILL AID CLOUD
DECK TO THICKEN AND LOWER INTO MVFR 1800 FEET AT BKW AND THE
SOUTHERN THIRD OF THE AREA BY THIS AFTERNOON AND EVENING.
CONDITIONS WILL IMPROVE AFTER 22Z...FOR A GRADUAL RETURN OF VFR
CONDITIONS TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: ISOLATED IFR COULD RESULT OVER THE CENTRAL
AND SOUTHERN MOUNTAINS THIS AFTERNOON AND EVENING DUE TO LOW
CHANCE RAIN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY H H H H M M M M H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M L M H M H H H H H H L
EKN CONSISTENCY H H H H H M M M H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z TUESDAY...
IFR IN RAIN WED AND WED NT...AND IN RAIN AND SNOW SHOWERS THURSDAY
AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/ARJ
NEAR TERM...30
SHORT TERM...26
LONG TERM...KTB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
639 AM EST MON JAN 9 2012
.SYNOPSIS...
WEAK DISTURBANCE BRINGS LIGHT RAIN TO MAINLY THE SOUTHERN MOUNTAINS
MONDAY. HIGH PRESSURE TUESDAY. LOW PRESSURE WEDNESDAY. COLDER AIR
ARRIVES ON THURSDAY ON GUSTY WINDS AND LASTS INTO WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
MID TO HIGH CLOUDS WILL THICKEN AND LOWERED AS A H5 WAVE APPROACHES
FROM THE WEST. MODELS QPF FIELD SUGGEST VERY LIGHT PCPN ACROSS THE
EXTREME SOUTHERN THIRD OF OUR CWA...AND ALONG THE EASTERN MOUNTAINS
THIS MORNING.
MOST PCPN WILL STRUGGLE TO REACH THE GROUND PER A DRY LOW LEVEL
LAYER...AS SEEN IN RUC BUFKIT SOUNDINGS ACROSS THE LOWLANDS.
HOWEVER...SATURATION SPREADS TOWARD THE SFC ALLOWING SOME PCPN TO
REACH THE GROUND ALONG THE MOUNTAINS. THESE PCPN WILL BE BRIEF AND
NONE OR VERY LIGHT ACCUMULATIONS CAN BE EXPECTED.
SOME OF THE COLDEST VALLEYS WILL STILL BE AROUND 31 DEGREES THROUGH
AT LEAST 9 AM.
WENT WITH A BLEND BETWEEN THE BIAS CORRECTED SOLNS OF SREF AND
WRFARW FOR HIGHS TODAY...AND WITH THE WRFARW FOR LOWS TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
HIGH PRESSURE DRIFTS TO THE MID ATLANTIC COAST WHILE CLOSED LOW OVER
THE DEEP SOUTH MAKES A TURN NORTHEASTWARD INTO THE APPALACHIANS.
MODELS HAVE A FAIRLY GOOD HANDLE ON THE TIMING OF THE RAIN SHIELD
ENTERING THE CWA...AND RAMP THE POPS UP QUITE QUICKLY GENERALLY
AFTER 12Z WEDNESDAY WITH WELL DEFINED FORCING IN THE FORM OF
DEFORMATION AT PLAY HERE. DID SLOW DOWN THE ONSET OF THE CLOUD COVER
FROM THE PREVIOUS FORECAST BY ABOUT 6 HOURS OR SO. CHALLENGE TO THE
FORECAST COMES WHEN THE CLOSED LOW PASSES TO THE EAST AND INTO THE
DELMARVA WHILE A STRONG COLD FRONT ADVECTS ANOTHER SIGNIFICANTLY
COLDER AIRMASS FROM THE NORTHWEST. FLOW WILL BECOME
NORTHWESTERLY...AND THE FAMILIAR UPSLOPE PATTERN BEGINS AS
TEMPERATURES DROP THROUGH THE DAY THURSDAY. THIS WILL LEAD TO A
CHANGE IN THE PRECIPITATION FROM RAIN TO SNOW...WITH THE SNOW MAINLY
COMING BEYOND THE SCOPE OF THE SHORT TERM FORECAST PERIODS. THE TWO
MAIN QUESTIONS AS OF NOW ARE WILL THERE BE A LULL IN THE
PRECIPITATION JUST AFTER FROPA...AND WHEN WILL THE TRANSITION TO
SNOW OCCUR. WILL GO AGGRESSIVE WITH THE POPS WEDNESDAY NIGHT AND
THURSDAY...AND KEEP THE PRECIPITATION TYPE CHANGE LATE THURSDAY
WHERE QPF WILL BE QUITE A BIT LOWER THAN WITH THE CLOSED LOW.
HAVE NOT TRIED TO GET TOO CUTE WITH THE TEMPERATURES WEDNESDAY
THROUGH THURSDAY. TREND IS TO MODESTLY WARM ADVECT AT FIRST WITH THE
APPROACH OF THE UPPER LEVEL SYSTEM...KEEPING TEMPERATURES ON PACE
WITH THE ABOVE NORMAL TRENDS SEEN OF LATE. THURSDAY VALUES WILL NOT
RECOVER MUCH FROM THE WEDNESDAY NIGHT LOWS WITH THE ONSET OF THE
COLD ADVECTION...AND FEEL A BLEND OF THE MOSGUIDE AND MEX WAS BEST
OUT THIS FAR.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MAIN SUPPORT ALOFT STILL MOVING THROUGH WEDNESDAY EVENING. AS LIKE
24 HOURS...THE 12Z GFS RUN IS THE STRONGEST ON THE SUPPORT AND AS A
RESULT THE HEAVIEST ON ITS RAINFALL. MAY BE A MAXIMUM RAINFALL
ALONG THE OHIO RIVER COUNTIES AND ANOTHER ON THE SE UPSLOPE IN THE
CENTRAL WV MOUNTAINS. WILL LEAVE IMPACT FOR RAIN IN THE CRWRWSRLX
BUT NO HAZARD FOR FLOODING IN THE HAZARDOUS WEATHER OUTLOOK...SINCE
STILL A PROGRESSIVE SYSTEM AND LITTLE OR NO SNOW PACK LEFT.
PRECIPITABLE WATER STILL PEAKING AROUND AN INCH.
STILL THINKING THE COLDER AIR WILL BE TAKING ITS TIME MOVING IN. SO
AS YESTERDAY...KEPT MINIMUM TEMPERATURES AOA MOS GUIDANCE WEDNESDAY
NIGHT. WILL HAVE TEMPERATURES FALLING THURSDAY AFTERNOON.
LIKE 24 HOURS AGO...THE TREND TO KEPT THE COLDER AIR HERE THROUGH
THE WEEKEND STILL EXISTS. SO KEPT TEMPERATURES COLDER THAN OUR HPC
MEDIUM RANGE SUPPORT. SEVERAL SMALL DISTURBANCE AROUND THE 500 MB
TROF...OR CLOSED LOW...IN SRN GREAT LAKES INTO SATURDAY. SO THE
SNOW SHOWER ACTIVITY MAY COME AND GO FRIDAY INTO SATURDAY. HAVE KEPT
POPS HIGHER THAN GUIDANCE MAINLY CRW ON N-NE. HOWEVER...THE MID AND
LOW LEVEL FLOW MAINLY WEST AND WESTNORTHWEST IN THIS PATTERN.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS UNDER BKN100 CEILINGS TO PREVAIL AT LEAST THROUGH
15Z MONDAY...WITH THE EXCEPTION OF MVFR CEILINGS AROUND 2000 FEET
POSSIBLE ALONG CENTRAL AND EASTERN MOUNTAINS.
A MID LEVEL DISTURBANCE APPROACHING FROM THE WEST WILL AID CLOUD
DECK TO THICKEN AND LOWER INTO MVFR 1800 FEET AT BKW AND THE
SOUTHERN THIRD OF THE AREA BY THIS AFTERNOON AND EVENING.
CONDITIONS WILL IMPROVE AFTER 22Z...FOR A GRADUAL RETURN OF VFR
CONDITIONS TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: ISOLATED IFR COULD RESULT OVER THE CENTRAL
AND SOUTHERN MOUNTAINS THIS AFTERNOON AND EVENING DUE TO LOW
CHANCE RAIN.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M M H L M L H M H H H H
EKN CONSISTENCY H M H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z TUESDAY...
IFR IN RAIN WED AND WED NT...AND IN RAIN AND SNOW SHOWERS THURSDAY
AND THURSDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
WVZ038-046-047.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/ARJ
NEAR TERM...ARJ
SHORT TERM...26
LONG TERM...KTB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
546 AM CST MON JAN 9 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
215 AM CST MON JAN 9 2012
MAIN FORECAST CONCERNS ARE ON TEMPERATURES THROUGH TUESDAY NIGHT...
THEN THE COOL DOWN AND PRECIPITATION CHANCES FOR MIDWEEK.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING FROM CALIFORNIA INTO SOUTHERN ALBERTA...A CUT-OFF
UPPER LOW OVER NORTHERN MEXICO...BROAD TROUGHING OVER SOUTHEAST
CANADA INTO THE GREAT LAKES...AND A SHORTWAVE OVER NORTHERN
MINNESOTA. THIS SHORTWAVE IS PRODUCING AN AREA OF MID AND HIGH
CLOUDS ACROSS MUCH OF MINNESOTA INTO NORTHERN WISCONSIN...AS WELL
AS A TIGHTER SURFACE PRESSURE GRADIENT. 925MB RUC AND VAD WIND
PROFILE DATA REFLECT THE INCREASING PRESSURE GRADIENT...WITH
SOUTHWEST WINDS OF 40-45KT ACROSS MUCH OF MINNESOTA. THESE WINDS
ARE ADVECTING WARMER AIR EASTWARD...NOTED BY A 1-3C INCREASE IN
925MB TEMPS AT MPX...ABR AND BIS BETWEEN 12Z YESTERDAY AND 00Z
TODAY PER RAOB DATA. 00Z DATA NOW SHOW READINGS BETWEEN
1-3C...HIGHEST AT BIS. SURFACE TEMPERATURES HAVE RESPONDED TO THE
INCREASING WINDS...CLOUDS AND WARM ADVECTION BY MOSTLY STAYING IN
THE 20S TO LOW 30S. AIRMASS REMAINS DRY AS WELL OVER THE UPPER
MIDWEST WITH 10C OR HIGHER DEWPOINT DEPRESSIONS BELOW 600MB ON THE
00Z BIS...ABR AND MPX SOUNDINGS.
TODAY AND TONIGHT...SHORTWAVE OVER NORTHERN MINNESOTA IS FORECAST TO
DIVE SOUTHEAST INTO LOWER MICHIGAN BY 00Z. IN ITS WAKE...500MB
HEIGHTS ARE EXPECTED TO GRADUALLY RISE OVER THE FORECAST AREA. THESE
HEIGHT RISES SHOULD CONTINUE THROUGH TONIGHT...AND THESE ARE IN
RESPONSE TO A POTENT TROUGH DEVELOPING OVER SOUTHWEST CANADA.
SUBSIDENCE ASSOCIATED WITH THE HEIGHT RISES...IN COMBINATION WITH
ALL THE DRY AIR PRESENT OVER THE AREA...WILL RESULT IN CONTINUED DRY
CONDITIONS. THE HEIGHT RISES ALSO MEAN CONTINUED WARM ADVECTION...
REFLECTED BY 925MB TEMPS CLIMBING TO 0-2C BY 18Z TODAY. THESE ARE
AROUND 2C HIGHER THAN YESTERDAY AT 18Z. SUNSHINE MAY BE SOMEWHAT
LIMITED INITIALLY THIS MORNING BY THE MID AND HIGH CLOUDS...BUT
THESE SHOULD CLEAR IN THE AFTERNOON AS THE SHORTWAVE MOVES AWAY FROM
THE AREA. IT DOES TO LOOK TO STAY BREEZY THIS MORNING WITH THE
PRESSURE GRADIENT FAIRLY TIGHT...AS WELL AS THAT 925MB WIND CORE
COMING ACROSS. THE WINDS SHOULD DIMINISH IN THE AFTERNOON...ALSO DUE
TO THE SHORTWAVE MOVING AWAY FROM THE AREA AND A WEAK SURFACE RIDGE
DEVELOPING OVER MINNESOTA. ALL IN ALL WE SHOULD END UP WITH PLENTY
OF MIXING...FROM THE WINDS THIS MORNING AND SUN IN THE AFTERNOON...
ALLOWING TEMPERATURES TO CLIMB WELL INTO THE 40S FOR MOST LOCATIONS.
THE SURFACE RIDGE MOVES OVER THE AREA TONIGHT...AND WITH ONLY SOME
SCATTERED MID CLOUDS POSSIBLE...ANTICIPATING TEMPERATURES TO FALL
OFF INTO THE 20S TO LOW 30S. THIS IS DESPITE SOME 925MB WARMING
WHICH REACHES 2-5C BY 12Z.
TUESDAY AND TUESDAY NIGHT...MODELS ARE IN GOOD AGREEMENT DIGGING THE
POTENT UPPER TROUGH SOUTHEAST INTO EASTERN MONTANA AND NORTH DAKOTA
BY 12Z WEDNESDAY. AS THIS UPPER TROUGH DIGS SOUTHEAST...A COLD FRONT
WELL OUT AHEAD OF IT SHOULD MOVE INTO AND PERHAPS THROUGH THE
FORECAST AREA BETWEEN 06-12Z WEDNESDAY. NOT ANTICIPATING ANY
PRECIPITATION ON OR AHEAD OF THE FRONT DUE TO AGAIN THE DRY AIRMASS.
EVEN BEHIND THE FRONT...ANY PRECIPITATION LOOKS TO STAY A LITTLE
FARTHER WEST...CLOSER TO THE DPVA FORCING WITH THE UPPER TROUGH AND
MID-LEVEL FRONTOGENESIS. SO PERHAPS BY 12Z...SOME PRECIPITATION
COULD BE APPROACHING I-35 AND FAR NORTHWEST WI...ASSUMING THE
ATMOSPHERE CAN SATURATE. FOR OUR AREA...MAIN CONCERN IS THE WARMING
OCCURRING AHEAD OF THE FRONT. 925MB TEMPS CLIMB A LITTLE FURTHER ON
TUESDAY TO 3-6C BY 18Z. OTHER THAN MAYBE FOR A FEW MID OR HIGH
CLOUDS AT BEST...SHOULD SEE MOSTLY SUNNY SKIES. WINDS PICK UP TOO
WITH THE DIGGING OF THE UPPER TROUGH...ALBEIT ONLY 5 TO 15 KT.
STILL...IT IS OUT OF A FAVORABLE SOUTHWEST DIRECTION. SO ALL SIGNS
POINT TO GOOD MIXING ON TUESDAY. HIGHS SHOULD EASILY CLIMB WELL INTO
THE 40S WITH LOW 50S LIKELY TOO. COOLING SHOULD OCCUR GRADUALLY
TUESDAY EVENING...THEN PERHAPS PICK UP SOME AFTER MIDNIGHT WITH
THE COLD FRONTAL PASSAGE. ON THE OTHER HAND...THE WINDS BEHIND THE
FRONT ADVECTING IN COLDER AIR MAY ALSO HELP TO KEEP THE ATMOSPHERE
MIXED. THEREFORE...HAVE FOLLOWED A BLEND OF GUIDANCE FOR LOWS.
WEDNESDAY AND WEDNESDAY NIGHT...SOME DIFFERENCES BEGIN TO SHOW UP
WITH THE HANDLING OF THE POTENT UPPER TROUGH. THE 09.00Z GFS/NAM AND
08.12Z/09.00Z ECMWF SHOW THE UPPER TROUGH MOVING OVER MUCH OF
MINNESOTA BY 00Z THURSDAY AND OVER MUCH OF THE FORECAST AREA BY 12Z
THURSDAY. WITHIN THIS GROUP...THE ECMWF SHOWS AN UPPER LOW IN
SOUTHERN MINNESOTA WHEREAS THE GFS/NAM PLACE IT IN WESTERN UPPER
MICHIGAN. THE 09.00Z UKMET/CANADIAN ON THE OTHER HAND HAVE A SLOWER
UPPER TROUGH...KEEPING IT STILL IN THE DAKOTAS AT 00Z THURSDAY...
THEN MOVING INTO MINNESOTA POSITIVELY TILTED BY 12Z THURSDAY AND NO
UPPER LOW CENTER. HPC PMDHMD PRODUCT DETAILS A LOT OF ISSUES WITH
THE 08.12Z/09.00Z ECMWF...09.00Z GFS AND NAM REGARDING THIS
TROUGH... SAYING THEY ARE ALL TOO AMPLIFIED AND FAST. A PREFERENCE
IS FOR A SLOWER SOLUTION...WHICH WOULD MATCH THE TREND SEEN WITH THE
08.00Z MODELS. THE SPEED OF THE TROUGH HAS BIG IMPACTS ON
WEDNESDAYS HIGHS...SINCE THE COLD AIR WOULD FLOW IN FASTER IN THE
08.12Z AND ESPECIALLY 09.00Z GFS/NAM SCENARIOS. EITHER WAY...THE
COLD AIR WILL EVENTUALLY FLOW INTO THE FORECAST AREA...WITH ALL
MODELS SHOWING 850MB TEMPS TANKING TO -16 TO -20C BY 12Z THURSDAY.
UNTIL MODELS RESOLVE THE TIMING...HAVE LEFT THE TEMPERATURE
FORECASTS MOSTLY ALONE...KEEPING TOO THAT FALLING TEMPERATURE TREND
WEDNESDAY AFTERNOON SINCE EVEN THE SLOWER SOLUTIONS WOULD SUGGEST
THAT. PRECIPITATION IS LOOKING HARDER AND HARDER TO COME BY WITH
THIS UPPER TROUGH. CERTAINLY THE DYNAMICS LOOK IMPRESSIVE...EVEN
WITH THE POSITIVELY TILTED SOLUTIONS WHICH HAVE ANYWHERE FROM 60-100
METER HEIGHT FALLS AT 500MB FOR WEDNESDAY AND AGAIN WEDNESDAY NIGHT.
HOWEVER...THE MOISTURE IS VERY LIMITED...DUE TO THE DRY AIRMASS
AHEAD OF THE TROUGH AND GULF OF MEXICO MOISTURE CUT-OFF FROM AN
UPPER LOW RIDING THROUGH THERE. MODELS AT BEST SHOW A COUPLE OF
HUNDREDTHS OF QPF COMING THROUGH THE FORECAST AREA...AND THAT IS
MOSTLY ON WEDNESDAY. THEREFORE...HAVE KEPT PRECIPITATION CHANCES IN
THE 20-50 RANGE FOR NOW.
.LONG TERM...THURSDAY THROUGH SUNDAY NIGHT
215 AM CST MON JAN 9 2012
09.00Z ECMWF/GFS/CANADIAN AND GFS ENSEMBLES AGREE IN GENERAL WITH
THE MEAN UPPER LEVEL PATTERN THROUGHOUT THE EXTENDED...WHICH
FEATURES MOSTLY TROUGHING OVER THE CENTRAL AND EASTERN U.S.. MOST OF
THIS TROUGHING STARTS FROM THAT POTENT TROUGH DROPPING DOWN INTO THE
FORECAST AREA WEDNESDAY NIGHT. THE TROUGHING THEN GETS REINFORCED BY
A SHORTWAVE DROPPING SOUTH THROUGH THE UPPER MIDWEST FRIDAY
NIGHT...PERHAPS CROSSING THE FORECAST AREA ON SATURDAY ACCORDING TO
SOME MODEL SOLUTIONS. THERE ARE INDICATIONS THAT RIDGING WILL BUILD
TOWARDS THE AREA ON SUNDAY DUE TO TROUGHING DROPPING DOWN INTO
BRITISH COLUMBIA AND WASHINGTON STATE.
THURSDAY THROUGH FRIDAY ARE LIKELY TO BE QUITE CHILLY...COMPARED TO
WHAT WE HAVE SEEN RECENTLY...WITH 850MB TEMPS DROPPING TO AROUND
-20C BY 00Z FRIDAY. MOSTLY CLOUDY SKIES WILL ALSO LIMIT DIURNAL
HEATING...THOUGH AT THE SAME TIME HELP TEMPERATURES FROM TANKING
THURSDAY NIGHT. SOME SLOW MODERATION IS ANTICIPATED FOR FRIDAY AS
THE CORE OF THE COLD AIR LIFTS OUT TO THE NORTHEAST...BUT STILL
READINGS SHOULD STAY BELOW NORMAL. THE SLOW MODERATION CONTINUES
THROUGH THE WEEKEND...ESPECIALLY ON SUNDAY WHEN THE RIDGING STARTS
BUILDING IN. THROUGHOUT THE LONG TERM PERIOD...FOLLOWED A CONSENSUS
OF GUIDANCE FOR TEMPERATURES.
PRECIPITATION CHANCES LOOKS PRETTY SLIM DUE TO AGAIN A LACK OF
MOISTURE. 09.00Z ECMWF HINTING THAT THERE COULD BE A LITTLE LIGHT
SNOW THURSDAY NIGHT WRAPPING AROUND...BUT IT IS THE ONLY MODEL
SHOWING IT. PLUS...WITH THE CONCERN MENTIONED IN THE WEDNESDAY
DISCUSSION ABOVE ABOUT THE ECMWF...NOT READY TO JUMP ON PUTTING
PRECIPITATION CHANCES IN FOR THURSDAY NIGHT. NEXT POTENTIAL TIME
PERIOD FOR PRECIPITATION CHANCES WOULD COME SATURDAY WITH THE
SHORTWAVE COMING THROUGH. HOWEVER...MODELS HAVE BEEN FAR FROM
CONSISTENT ON THE TRACK OF THIS SHORTWAVE...AND SOME HAVE IT GOING
NORTH AND SOUTH OF THE AREA FOR THIS 09.00Z CYCLE. THEREFORE...HAVE
MAINTAINED SATURDAY DRY TOO. THIS RESULTS IN THE ENTIRE LONG TERM
FORECAST DRY FOR NOW.
&&
.AVIATION...TODAY AND TONIGHT
546 AM CST MON JAN 9 2012
BROKEN MID LEVEL CLOUDS WILL SHIFT EAST OF THE TAF SITES THIS
MORNING. PLAN ON CLOUD BASES AROUND 12 KFT EARLY THIS
MORNING...THEN SKIES WILL BECOME MOSTLY CLEAR BY MID MORNING. PLAN
ON LOW LEVEL WIND SHEAR AT KLSE THROUGH AROUND 14Z AS THE
MISSISSIPPI RIVER VALLEY REMAINS DECOUPLED...WITH SURFACE WINDS
SOUTH AT AROUND 6 KTS. VAD WIND PROFILES SHOW WINDS INCREASING TO
AROUND 40 KTS AT 1KFT AT 1143 Z. FORECAST SOUNDINGS ALSO INDICATE
THIS LLWS...SO HAVE INCLUDED IT IN THE KLSE TAF. OTHERWISE LOOK
FOR SOUTHWEST WINDS AT 15 TO 18 KTS WITH GUSTS TO AROUND 27 KTS
POSSIBLE. THE WINDS WILL GRADUALLY DIMINISH THIS AFTERNOON AS THE
PRESSURE GRADIENT SLACKENS...DECREASING TO AROUND 8 KTS BY 22Z.
WINDS ARE EXPECTED TO BECOME LIGHT THIS EVENING WITH GUIDANCE
SHOWING THE POTENTIAL FOR SOME BR OR FOG. GIVEN THE DRYNESS OF THE
LOWER LEVELS AND SOME HIGH CLOUDS MOVING INTO THE
REGION...THINKING OVERALL FOG THREAT LOOKS MINIMAL. HAVE DECIDED
TO INCLUDE 5SM BR AT THE TAF SITES STARTING AT 03Z. WILL HAVE TO
KEEP A CLOSE WATCH ON CLOUDS AND LOW LEVEL RELATIVE HUMIDITY THIS
EVENING. IF THE LOW LEVEL MOISTURE INCREASES AND CLOUDS DO NOT
MATERIALIZE...IFR CONDITIONS ARE A POSSIBILITY TONIGHT IN FOG.
CONFIDENCE LOW ON IFR CONDITIONS OCCURRING TONIGHT...BUT WILL
CONTINUE TO CLOSELY MONITOR TRENDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
215 AM CST MON JAN 9 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....WETENKAMP
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
442 PM EST MON JAN 9 2012
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL RIDGE
FROM CA INTO ALBERTA/SASK AND A TROUGH INTO HUDSON BAY RESULTING IN
NW FLOW DONWSTREAM INTO THE WESTERN GREAT LAKES. DRY AND WARMER AIR
HAS MOVED INTO THE CWA BEHIND A MID LEVEL SHORTWAVE AND SFC TROUGH
THAT BROUGHT LIGHT SNOW TO ERN UPPER MI THIS MORNING. THE TIGHT
GRADIENT IN THE WAKE OF THE TROUGH WITH WRLY WINDS INTO THE KEWEENAW
HAS BROUGHT BLUSTERY WINDS TO THE KEWEENAW WITH SOME GUSTS IN THE 35
TO 45 MPH RANGE. THE VIS SATELLITE LOOP SHOWED MAINLY CLEAR SKIES
OVER THE AREA WHICH HAS ALLOWED TEMPS TO CLIMB INTO THE LOWER TO MID
40S OVER THE WEST HALF OF THE AREA
&&
.SHORT TERM...TONIGHT AND TUESDAY
EXPECT THAT THE WINDS WILL DIMINISH QUICKLY LATE THIS AFTERNOON AND
EVENING AS A SFC RIDGE BUILDS INTO THE AREA. SATELLITE TRENDS AND
NAM SFC-850 MB RH PROGS SUGGEST THAT LOWER LEVEL MOISTURE OVER FAR
NE MN AND NRN LAKE SUPERIOR WILL GENERALLY MOVE OFF TO THE EAST.
WITH THE THE LIGHTER WINDS AND MAINLY CLEAR SKIES SHOULD ALLOW TEMPS
TO DROP AT OR BLO DEWPOINTS...INTO THE LOWER TO MID 20S. ALTHOUGH
MID/HIGH CLOUDS MAY INCREASE WITH THE DEVELOPING WAA PATTERN...THERE
SHOULD BE ENOUGH INSOLATION TO PUSH TEMPS WELL ABOVE NORMAL.
SO...CONTINUED TO KEEP FCST MAX READINGS SEVERAL DEGREES ABOVE
SOMEWHAT CLIMATOLOGY WEIGHTED GUIDANCE...INTO THE UPPER 30S TO MID
40S.
&&
.LONG TERM (TUE NIGHT THROUGH MONDAY)...
MAIN FORECAST CONCERNS FOR MID WEEK REVOLVE AROUND THE POTENTIAL FOR
HEAVY LAKE ENHANCED SNOW NEAR LAKE SUPERIOR.
MODEL GUIDANCE BEGINS TO DIVERGE RATHER QUICKLY TUESDAY EVENING INTO
WEDNESDAY REGARDING THE EVOLUTION OF THE CLOSED LOW MOVING OVER THE
UPPER GREAT LAKES. THE NAM SEEMS TO BE THE OUTLIER WITH THE SOLUTION
BEING PROGRESSIVE AND LESS AMPLIFIED COMPARED TO THE GFS...ECMWF AND
GEM SOLUTIONS WHICH ARE MORE AMPLIFIED AND MUCH SLOWER ESPECIALLY BY
THU. HOWEVER...EVEN AMONG THOSE THREE SOLUTIONS...THERE REMAINS
SUBTLE DIFFERENCES IN THE MASS FIELDS WHICH WILL PLAY AN IMPORTANT
ROLE WHERE THE HEAVIEST SNOW FALLS WED NIGHT INTO FRIDAY. ALL THREE
OF THE MODELS CLOSE OFF THE LOW AND SLOW IT DOWN OVER THE UPPER
GREAT LAKES. HOWEVER...THE ECMWF AND THE GEM TEND TO BE THE MOST
AMPLIFIED AND FURTHEST SOUTH COMPARED TO THE GFS. WITH THAT BEING
SAID...HAVE GENERALLY OPTED TO FOLLOW A ECMWF/GEM BLEND THROUGH THE
PERIOD.
ON TUESDAY NIGHT...EXPECT THE SURFACE LOW TO MOVE FROM THE CANADIAN
PRAIRIES TO WESTERN UPPER MICHIGAN BY WED MORNING. WILL BE TOUGH FOR
ANY PCPN TO FALL TUE NIGHT AHEAD OF THE SYSTEM WITH SYSTEM BEING OF
PACIFIC ORIGIN AND THE BEST MOISTURE BEING ROBBED BY THE SOUTHERN
STREAM SYSTEM OVER THE OHIO VALLEY. SOUTH-SOUTHWEST LOW LEVEL FLOW
WILL AHEAD OF THE SYSTEM WILL ALLOW FOR MILD TEMPS TUE NIGHT WITH
STRATUS POSSIBLE AS LOW LEVEL DEW POINTS INCREASE. HOWEVER...WITH
THE VERY DRY AIRMASS ALOFT ANY PCPN WILL NOT DEVELOP UNTIL WEDNESDAY
BEHIND THE LOW. THE LOW LEVEL STRATUS MAY SERVE AS A CATALYST FOR
DRIZZLE OR FREEZING DRIZZLE...AND IN FACT THE MODEL PROFILES FROM
THE NAM SUGGEST ESPECIALLY IN NORTH CENTRAL UPPER MICHIGAN THIS IS
POSSIBLE. HOWEVER...THE GFS IS NOT AS AGGRESSIVE IN THE LOW LEVEL
MOISTURE SO HAVE OPTED TO KEEP THIS OUT OF THE FORECAST FOR NOW.
THE ECMWF SHOWS THE LOW SLOWLY PASSING OVER OR JUST TO THE SOUTH OF
THE AREA ON WEDNESDAY AS THE UPPER LOW DIGS INTO THE NORTHERN MS
VLY. AS THE LOW MOVES EAST...COLDER AIR ALOFT MOVES ACROSS THE AREA.
SINCE MOST OF THE MOISTURE WILL LIKELY BE ASSOCIATED WITH THE
DEFORMATION AXIS TO THE NORTH AND WEST OF THE LOW...AND GIVEN THE
LOW WET BULB ZERO LEVELS...THE EXPECTATION IS THAT ANY PCPN WILL
FALL AS SNOW STARTING LATE WED MORNING ACROSS THE WEST THEN
EXPANDING EAST BY WED EVENING. LAKE EFFECT/ENHANCED SNOW WILL ALSO
DEVELOP ACROSS WESTERN UPPER MICHIGAN WED AFTN IN RESPONSE TO THE
NORTHWEST FLOW AND COLDER TEMPS ALOFT. WITH THIS BEING SAID...HAVE
OPTED TO MAINTAIN LIKELY POPS ACROSS THE WEST AND CHANCE POPS EAST.
DUE TO THE SOUTH FLOW NEAR LAKE MICHIGAN AND WARMER TEMPS
ALOFT...WILL KEEP A MENTION OF RAIN NEAR LAKE MICHIGAN THROUGH WED
EVENING BEFORE THE COLDER AIR ARRIVES.
LES WILL INCREASE IN COVERAGE AND INTENSITY WED NIGHT AND ESPECIALLY
ON THURSDAY DOWNWIND OF LAKE SUPERIOR. STILL SOME UNCERTAINTY OF THE
EXACT PLACEMENT OF THE HEAVIEST LES...BUT THE ECMWF AND THE GEM
WOULD IMPLY A MORE NORTHERLY BOUNDARY LAYER FLOW WHICH WOULD BRING
HEAVY SNOW INTO MUCH OF NORTHERN UPPER MICHIGAN. IN FACT...IF THE
ECMWF VERIFIES...THE FLOW THROUGH 700MB WILL BECOME NNE AS THE UPPER
LOW ROTATES INTO LOWER MICHIGAN ON THURSDAY INTO THU NIGHT WHILE THE
SFC LOW DEEPENS. THIS TYPE OF SCENARIO WOULD IMPLY A SIGNIFICANT
SNOWFALL FOR THE HIGHLANDS OF MARQUETTE COUNTY AS WELL...ESPECIALLY
SINCE THE ECMWF SUGGESTS SYNOPTIC SUPPORT WITH THE UPPER TROUGH
OVERHEAD. WILL CONTINUE WITH CATEGORICAL OR HIGH LIKELY POPS FOR
ALL AREAS IMMEDIATELY DOWNWIND OF LAKE SUPERIOR THU INTO THU NIGHT.
THE LOW FINALLY STARTS TO MOVE EAST ON FRIDAY ALLOWING ANY REMAINING
LES TO DIMINISH BY EVENING. QUIET WEATHER ON SATURDAY AS WEAK HIGH
PRESSURE RIDGE BUILDS ACROSS THE REGION BEFORE AN ALBERTA CLIPPER
TYPE SYSTEM ARRIVES SUNDAY. BEST MOISTURE REMAINS NORTH OF THE AREA
AND HAVE OPTED TO CONFINE LOW CHANCE POPS TO NEAR LAKE SUPERIOR.
TEMPS WILL REMAIN WELL ABOVE NORMAL TUE NIGHT INTO WED BEFORE
FALLING 10-20 DEGREES ON THURSDAY. ALTHOUGH THE BEST COLD AIR MAY
STAY WEST OF THE AREA...TEMPS WILL STILL STRUGGLE TO RISE MUCH ON
THURSDAY. WILL GO WITH TEMPS IN THE TEENS WEST AND MID 20S EAST.
CONTINUED COLD ON FRIDAY BEFORE SOME SLIGHT WARMING FOR THE WEEKEND
INTO MONDAY. HOWEVER...TEMPERATURES WILL REMAIN AT OR SLIGHTLY BELOW
NORMAL.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
EXPECT PREVAILING VFR CONDITIONS FOR MOST OF THE FCST PERIOD.
SATELLITE AND SFC OBS UPSTREAM SUGGEST THAT UPSLOPE WRLY FLOW MAY
BRING SOME MVFR CIGS INTO THE AREA THIS AFTERNOON.
HOWEVER...CONFIDENCE IS LOW WITH THE TIMING/DEVELOPMENT OF THE LOWER
CLOUDS. OTHERWISE...VERY GUSTY WEST WINDS AT KCMX WILL DIMINISH THIS
EVENING AS A RIDGE BUILDS TOWARD THE AREA AND THE GRADIENT WEAKENS.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
GALE FORCE WEST WINDS OVER THE EAST HALF OF THE LAKE WILL DIMINISH
BY THIS EVENING AS HIGH PRESSURE BUILDS TOWARD THE REGION AND THE
GRADIENT WEAKENS. WINDS WILL DIMINISH BLO 20 KTS BY TUESDAY MORNING
WITH A WEAKENING PRESSURE GRADIENT...BUT WILL INCREASE OUT OF THE
N-NW WEDNESDAY AFTERNOON INTO FRIDAY AS MUCH COLDER SPREADS ACROSS
THE REGION AND THE PRES GRADIENT TIGHTENS IN THE WAKE OF A DEEPENING
LOW PRESSURE SYSTEM TO OUR EAST. NRLY WINDS SHOULD REACH GALE GALE
FORCE THU INTO FRI WITH MODERATE TO HEAVY FREEZING SPRAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ265>267.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
SHORT TERM...JLB
LONG TERM...MRD
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1215 PM EST MON JAN 9 2012
LATEST UPDATE...AVIATION...
.SYNOPSIS...(427 AM EST MON JAN 9 2012)
A WEAK TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE AREA TODAY
RESULTING IN AN INCREASE IN CLOUDS AND A SLIGHT CHANCE OF RAIN OR
SNOW NORTH OF M-46. COLDER WEATHER WILL RETURN THURSDAY THROUGH THE
WEEKEND. ACCUMULATING LAKE EFFECT SNOWS ARE POSSIBLE THURSDAY
THROUGH THE WEEKEND.
&&
.SHORT TERM...(427 AM EST MON JAN 9 2012)
(TODAY THROUGH WEDNESDAY)
FORECAST CONCERNS ARE MINIMAL AGAIN TODAY. A WEAK TROUGH OF LOW
PRESSURE WILL MOVE ACROSS THE REGION TODAY. REGIONAL RADAR ALREADY
SHOWS SOME LIGHT RETURNS OVER WISCONSIN MOVING SOUTHEAST. ECMWF HAS
BEEN PRETTY CONSISTENT OVER THE PAST COUPLE OF DAYS SHOWING SOME
LIGHT PCPN CLIPPING THE NRN CWA. THE SREF ALSO SUPPORTS IT. HOWEVER
THE HRRR DOESN/T. I THINK THE THREAT OF MIXED PCPN OVER THE NRN CWA
IS WORTH A SLIGHT CHC AFTER 15Z OR SO. BETWEEN M-46 AND US-10 THE
PCPN WILL LIKELY BE RAIN IF WE SEE ANYTHING AT ALL.
SOME WEAK RIDGING WILL MOVE OVER THE LAKES TONIGHT AND TUESDAY
RESULTING IN PT CLDY SKIES AND DRY WX. ANOTHER CLIPPER WILL MOVE
SOUTHEAST FROM THE NRN PLAINS TOWARD LAKE SUPERIOR WEDNESDAY AS THE
SAME TIME A SRN STREAM SYSTEM IS MOVING ENE ACROSS THE TENNESSEE
VALLEY. ATTM IT APPEARS AS THOUGH THE SRN STREAM SYSTEM WILL BE TOO
FAR SOUTH TO RESULT IN PCPN OVER THE CWA. MOST OF THE WX ASSOCIATED
WITH THE CLIPPER WILL BE POST FRONTAL AND ARRIVE EITHER VERY LATE
WEDNESDAY AFTERNOON OR WEDNESDAY EVENING. THE COLD FRONT...BRINGING
A DECENT SHOT OF ARCTIC AIR...WILL MOVE ACROSS THE CWA WEDNESDAY
AFTERNOON.
&&
.LONG TERM...(427 AM EST MON JAN 9 2012)
(WEDNESDAY NIGHT THROUGH SUNDAY)
A PERIOD OF POTENTIALLY ACTIVE WINTER WEATHER LOOKS TO BE UNFOLDING
FOR LATE THIS WEEK INTO NEXT WEEKEND. MODELS HAVE BEEN CONSISTENT IN
SHOWING A DEEP LONGWAVE TROUGH BEING CARVED OUT OVER THE GREAT LAKES
REGION... AND RECENT SOLUTIONS ARE NOW HINTING THAT IT MAY HANG
AROUND FOR SEVERAL DAYS. THIS MEANS A PERIOD OF BELOW NORMAL
TEMPERATURES AND LAKE EFFECT SNOW CAN BE EXPECTED...WHICH HAS BEEN A
RARITY SO FAR THIS WINTER.
THE COLD AIR...H8 TEMPS OF -12C TO -16C...IS STILL PROGGED TO SWEEP
IN ON THURSDAY AND WILL HAVE LIKELY POPS IN THE WRN HALF OF THE CWFA
AS LAKE EFFECT COMMENCES. HOWEVER IT/S IMPORTANT TO NOTE THAT THE
MODELS ARE HANDLING THE H5 TROUGH EVOLUTION/PROGRESSION AND
ASSOCIATED SFC PRESSURE PATTERN SOMEWHAT DIFFERENTLY.
IF THE H5 TROUGH PROGRESSION IS SLOWED DUE TO CONTINUED DIGGING
UPSTREAM... THE SFC PATTERN COULD REMAIN LOOSE AND BAGGY ON
THURSDAY. THAT COULD EASILY DELAY THE ONSET OF THE BEST COLD AIR
INTRUSION UNTIL THURSDAY NIGHT AND FRIDAY.
EXACT WIND DIRECTION AND SUBSEQUENT LOCATION/ORIENTATION OF HEAVIEST
SNOW BANDS IS ALSO A BIT UNCLEAR AT THIS TIME SINCE IT WILL DEPEND
ON THE EVENTUAL POSITION/STRENGTH OF THE SFC LOW. EXTENT OF LAKE
AGGREGATE INDUCED SFC TROUGHING WILL ALSO BE A FACTOR IN BEHAVIOR OF
THE WINDS AND SNOW BANDS. INVERSION HEIGHTS/CONVECTIVE DEPTH SHOULD
BE DEEP THURSDAY NIGHT INTO FRIDAY WITH THE UPR LOW OVERHEAD.
THERE APPEARS TO BE GROWING SUPPORT FROM NUMERICAL GUIDANCE THAT
CLIPPER DISTURBANCES DIVING DOWN FROM THE NORTHWEST WILL HELP TO
REINFORCE THE TROUGHING OVER THE GREAT LAKES REGION NEXT WEEKEND.
THIS SYNOPTIC PATTERN IMPLIES THAT ADDITIONAL...PERHAPS FREQUENT...
EPISODES OF LAKE EFFECT/ENHANCED SNOWFALLS ARE POSSIBLE.
&&
.AVIATION...(1215 PM EST MON JAN 9 2012)
SW WINDS WILL CONTINUE TO GRADUALLY RAMP UP TO 15 TO 20 KTS WITH
GUSTS TO 25 KTS THIS AFTN/EARLY EVE. HIGHER GUSTS AROUND 30 KTS ARE
LIKELY AT KMKG. SKIES SHOULD BECOME MOSTLY CLEAR WITH DIMINISHING
WINDS OVERNIGHT. THIS MAY LEAD TO SOME PATCHY MVFR LIGHT FOG DURING
THE EARLY MORNING HRS TUE. OTHERWISE VFR CONDITIONS ANTICIPATED THRU
THE NEXT 24 HRS WITH EXTENSIVE CLEARING/WINDS UNDER 10 KTS TUE.
&&
.MARINE...(427 AM EST MON JAN 9 2012)
STARTED THE GALES A LITTLE EARLY TO AVOID DOUBLE HEADLINES. WINDS
WILL RAMP UP THIS MORNING AND HIT THEIR PEAK BY EARLY AFTERNOON.
ADDED A SCA SOUTH OF GRAND HAVEN ALSO DUE TO THE INCREASE IN WINDS
AND RESULTING HIGHER WAVES.
&&
.HYDROLOGY...(427 AM EST MON JAN 9 2012)
NO HYDRO ISSUES. COLDER AIR WILL RETURN LATER IN THE WEEK BUT WON/T
STAY AROUND LONG ENOUGH TO RESULT IN ICE BUILD UP.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING NORTH OF GRAND HAVEN TODAY.
SMALL CRAFT ADVISORY SOUTH OF GRAND HAVEN THROUGH TONIGHT.
&&
$$
SYNOPSIS: 93
SHORT TERM: 93
LONG TERM: MEADE
AVIATION: LAURENS
MARINE: 93
HYDROLOGY: 93
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SPOKANE WA
234 PM PST Mon Jan 9 2012
.SYNOPSIS...A storm system moves through the Inland Northwest
Monday night and Tuesday, with a chance of precipitation across
most of the region. The highest threat will be near the Cascades
and across the Blue Mountains, the Palouse and Idaho Panhandle
tonight, before decreasing from the west through Tuesday. High
pressure builds into the region starting late Tuesday, with dry
conditions and cooler temperatures through the end of the work
week. However watch for some patchy fog morning in the more
sheltered locations and near bodies of water. There is the
potential for more precipitation by next weekend.
&&
.DISCUSSION...
Tonight and Tomorrow...Front with weakening and elongating
subtropical moisture feed into it sags through Eastern Washington
and Northern Idaho tonight and exits to the southeast tomorrow.
The fact that the moisture feed is so narrow and appears to be
weakening as well as models showing a low spinning up along the
feed off the Northern California coast and further weakening the
feed continues to suggest the current course of action which is to
keep moderate to high pops but low precipitation and snow amounts
associated with the passage of this system. Kicker trof behind it
moves in with a drier and cooler northwest flow which allows for
an increase in wind and clearing conditions along with a cooling
trend apparent in forecast highs for tomorrow. Still some
uncertainty remains as latest HRRR model depicts a very elongated
and likely convectively enhanced band of precipitation forming
further north and west than what is depicted in the forecast but
still takes propagates it in the same general northwest to
southeast direction. /Pelatti
Tuesday night through Thursday: A shortwave trough exits early as
a ridge of high pressure builds in, bringing generally dry
conditions, occasional cloudy periods and cooler than normal
temperatures. On Tuesday evening the shortwave system moves toward
the High Plains. Save for the boundary layer, the atmosphere dries
out in the northwesterly flow behind it. A chance of snow showers
will linger around the central Panhandle in the evening but
otherwise dry weather is expected. Breezy conditions are expected
in the evening, then incoming high pressure will allow gradients
to slacken and winds to subside. How much the evening winds are
able to dry out the boundary layer will impact the potential for
stratus and fog overnight and Wednesday morning. The best chances
will be in the sheltered mountain valleys (from the Cascades
through the Selkirks and Central Panhandle Mountains) as well as
in the L-C valley. Fog is also a risk around the deeper basin, the
Long Lake and the Spokane River, as well as West Plains area;
however the moisture appears shallower and fog may be less
persistent here.
Going into Wednesday night and Thursday models track a couple
upper level disturbances across the region. With little deep
moisture and no strong connection to the surface, these
disturbances are expected to pass without any precipitation.
However look for increased middle to high level clouds. Fog and
stratus will once again be a threat Wednesday night and Thursday
morning, however coverage is expected to be less with the
aforementioned middle and high clouds. How thick or persistent or
widespread these clouds are will impact the potential for fog.
They will also impact temperatures.
Temperatures are expected to drop below normal through this
period, as cooler air invades from the north-northwest behind
Tuesday`s wave. With light winds and drier air coming in,
nighttime lows are expected to drop in the teens to low 20s, with
some single digits possible around the Cascades and northern
mountains. Afternoon highs are expected to be in the 20s and low
30s, with some teens in the mountains. Expect some moderation on
Thursday as compared to Wednesday. Overall values are projected to
be around 5 degrees or so below average. Precise numbers will be
impacted by the cloud and/or fog coverage; if more persistent cloud
cover develops, overnights lows may be too cool. /J. Cote`
Thursday night through Monday...Models are indicating a potential
pattern change towards the end of the extended period. The upper
ridge over the area is expected to flatten with a high amplitude
ridge developing between 150-160W out in the Eastern Pacific. This
would allow a cold trough in the Gulf of Alaska to drop southeast
towards Washington and North Idaho Sunday and Monday. The 12z and
00z runs of the ECMWF, Canadian, and UKMET extension favor this
with about half of the GFS Ensemble members also in support. Thus
the milder 12z GFS solution with trying to hold onto more ridging is
not as likely to pan out. But given the tendency for the ridge
this fall and winter, the 12z GFS can not be ruled out.
The Inland Northwest will be under generally dry zonal flow Friday
and Saturday with near normal temperatures. And then as the trough
drops over the area Sunday and Monday with 850mb temps cooling in
the -5 to -10C range...temperatures will lower to below normal
readings by Monday. The flow aloft remains westerly Sunday and
Monday so best potential for snow showers will be in the
mountains. JW
&&
.AVIATION...
18Z TAFS: Nuisance low clouds and fog linger near lowlands in the
lee of the East Slopes of the Northern Cascades and into portions of
the Columbia Basin this morning affecting locations such as KEAT and
KMWH this morning...otherwise clouds will continue to invade the sky
from a general west to east direction and will thicken and lower.
Precipitation will make a similar west to east motion through the
area as well generally starting near the Northern Cascades near 22Z,
00Z for KGEG and vicinity and 5Z for KPUW and KLWS. Mixture of
frozen and liquid precipitation north of I-90 with primarily liquid
south of it. All of this weather activity will allow for nuisance
IFR conditions due to varying height of stratus ceilings,
precipitation intensity and fog thickness occur in aviation
forecasts at times. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 29 33 18 28 19 28 / 60 10 0 0 0 0
Coeur d`Alene 29 35 17 31 18 29 / 70 10 0 0 0 0
Pullman 31 37 21 31 23 33 / 80 30 0 0 0 0
Lewiston 33 40 23 34 23 35 / 80 40 0 0 0 0
Colville 27 33 13 28 17 33 / 30 10 0 0 0 0
Sandpoint 30 34 16 28 17 30 / 70 10 0 0 0 0
Kellogg 29 35 20 28 18 29 / 90 30 0 0 0 0
Moses Lake 29 36 17 31 19 30 / 20 0 0 0 0 0
Wenatchee 28 35 22 29 20 32 / 10 0 0 0 0 0
Omak 27 31 14 29 16 31 / 10 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$