Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/12/12
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
348 PM PST TUE DEC 11 2012
.SHORT TERM DISCUSSION...
.SYNOPSIS...UNSETTLED WEATHER IS IN STORE FOR INTERIOR NORCAL
OVER THE NEXT WEEK. THE FIRST WEATHER DISTURBANCE MOVES INTO THE
AREA LATE TODAY INTO TONIGHT...BRINGING LIGHT RAIN TO THE CENTRAL
VALLEY AND SNOW TO THE MOUNTAINS. CHANCES OF PRECIP THEN CONTINUE
OFF AND ON THROUGH THE WEEKEND AND INTO NEXT WEEK.
SATELLITE PRODUCTS THIS AFTERNOON SHOW A DEEPENING LOW NOW
OFFSHORE FROM NORCAL...WITH MOISTURE AND COLDER CLOUD TOPS
STREAMING INLAND AROUND ITS BASE AND A SHOWERY AIRMASS UPSTREAM.
REGIONAL RADARS SHOW PRECIP AT THE LEADING EDGE REACHING THE
NORCAL COAST THIS AFTERNOON. THE RUC AND OTHER HIGH-RES MODELS
HAVE A GOOD HANDLE ON THIS LEADING COLD FRONT AND ASSOCIATED
PRECIP...AND SWING IT INTO THE NORTHERN SAC VALLEY WITHIN THE
NEXT 6 HOURS. THE FRONT TRACKS SOUTHWARD OVERNIGHT...REACHING THE
SAC METRO AREA BY AROUND MIDNIGHT. LATEST MODELS ARE CONTINUING
TO INDICATE DRYING OF THE MOISTURE STREAM OVER THE NEXT 12 HOURS.
AS SUCH...ONLY A QUARTER OR LESS OF RAIN IS EXPECTED ALONG THE
I80 CORRIDOR IN A QUICK BURST AS THE FRONT PASSES. THE SIERRA /
NORTHERN CASCADES SHOULD FARE BETTER WITH FAVORABLE OROGRAPHICS
IN EFFECT. SNOWFALL LOOKS A BIT LESS IMPRESSIVE THAN YESTERDAY`S
MODEL RUNS INDICATED...BUT STILL IN THE 4-8 INCH RANGE FOR MOST
PLACES.
SHOWERS WILL POP UP BEHIND THE FRONT WEDNESDAY MORNING AND
PERSIST INTO THE EVENING AS A ANOTHER VORTMAX SWINGS THROUGH
ALOFT AND PROVIDES SOME EXTRA LIFT. THOUGH LIQUID AMOUNTS WILL
NOT BE ANYTHING IMPRESSIVE...WITH THE COLDER AIRMASS MOVING IN
(-3C AT 850MB) SNOW TO LIQUID RATIOS WILL BE HIGHER THAN RECENT
STORMS...ALLOWING THE SHOWERS TO SQUEEZE OUT ADDITIONAL
ACCUMULATION IN THE MOUNTAINS. SNOW LEVELS WILL LOWER THROUGH THE
DAY...ALLOWING SOME LOCAL ACCUMULATIONS IN THE FOOTHILLS ABOVE
2500 FEET. ALSO...THE NAM IS STILL SHOWING UP TO 150 J/KG OF
MUCAPE FROM 0-3KM AGL WEDNESDAY AFTERNOON. WITH THE CLOSED LOW
ALOFT MOVING IN...WOULD NOT BE SURPRISED IF AN ISOLATED
THUNDERSTORM POPPED UP IN THE VALLEY. HAVE PUT SOME ISOLATED
THUNDER MENTION IN THE FORECAST FOR THE CENTRAL VALLEY...MOSTLY
SOUTH OF WILLOWS. IT`S TOUGH TO TELL WHETHER THIS THIN CAPE WILL
LEAD TO GARDEN-VARIETY CUMULUS/SHOWERS OR SOMETHING MORE. THE
DECIDING FACTOR MAY BE WHETHER A SURFACE WIND CONVERGENCE LINE
SETS UP SOMEWHERE IN THE VALLEY DURING THE DAY.
MOST OF THE AREA WILL SEE A BREAK THURSDAY WITH CLEARING SKIES
OVER THE VALLEY. WRAP-AROUND PRECIP MAY CONTINUE IN THE SIERRA
AROUND TAHOE SOUTHWARD...DEPENDING ON WHICH TRACK OF THE UPPER
LOW VERIFIES. ANOTHER TROUGH BRUSHES INTERIOR NORCAL
FRIDAY...HOWEVER FORECAST CONFIDENCE IS LOW IN THIS FEATURE AS
MODELS HAVE NOT BEEN ABLE TO AGREE ON THE TRACK OF THE TROUGH.
HAVE CONTINUED CHANCE POPS MOSTLY NORTH OF I-80 FOR FRIDAY. -DVC
.EXTENDED DISCUSSION (SATURDAY THROUGH TUESDAY)
A WEAK SHORTWAVE WILL PASS THROUGH ON SATURDAY WITH LIMITED
PRECIPITATION IN THE MOUNTAINS. A STRONGER SYSTEM WITH A COLD
FRONT ARRIVES SATURDAY NIGHT INTO SUNDAY BRINGING BETTER CHANCES
OF VALLEY RAIN AND MOUNTAIN SNOW. SNOW LEVELS AROUND 3000 TO 4000
FEET ARE EXPECTED WITH THIS RELATIVELY COOL SYSTEM. ACCUMULATING
SNOW COULD BE AN ISSUE WITH THIS STORM POTENTIALLY IMPACTING
WEEKEND TRAVEL. LINGERING PRECIPITATION IS POSSIBLE IN THE
MOUNTAINS SUNDAY EVENING BEFORE THE SYSTEM EXITS.
A DRY LULL COULD OCCUR BETWEEN LATE SUNDAY AND MONDAY WITH DRIER
NORTHWEST FLOW BEFORE YET ANOTHER QUICK MOVING WAVE PASSES THROUGH
LATE MONDAY INTO TUESDAY. MODELS ARE CONTINUING TO SHOW THIS
UNSETTLED PATTERN CONTINUING INTO NEXT WEEK. TEMPERATURES WILL BE
NEAR TO A LITTLE BELOW NORMAL FOR THE EXTENDED PERIOD. EK
&&
.AVIATION...
LOW CLOUDS AND FOG HAVE HAVE BEEN SLOW TO LIFT OUT OF THE VALLEYS
THIS AFTERNOON AND WILL CONTINUE THROUGH THE EVENING. A BAND OF
PRECIPITATION WILL MOVE ACROSS THE AREA TONIGHT AND TURN
SHOWERY TOMORROW. CEILINGS WILL CONTINUE IN MVFR AT MANY SPOTS AND
TURN MVFR AT OTHERS WITH THE INITIAL BAND. THIS STORM WILL ALSO
BRING SNOW TO THE SIERRA TONIGHT AND TOMORROW. MVFR/IFR
CIG/VIS...MOUNTAIN OBSCURATION AND ICING ARE LIKELY IN THE SIERRA
TONIGHT AND TOMORROW.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 PM PST
WEDNESDAY ABOVE 4500 FEET FOR THE WEST SLOPE NORTHERN SIERRA
NEVADA...WESTERN PLUMAS COUNTY/LASSEN PARK.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
320 PM MST MON DEC 10 2012
.SHORT TERM...STILL DEALING WITH A MODERATE NORTHWEST FLOW PATTERN
ACROSS COLORADO AND STILL PLENTY OF MOISTURE UPSTREAM TO KEEP
LIGHT SNOW GOING IN THE MOUNTAINS. DEEPEST MOISTURE WILL BE UNTIL
MIDNIGHT AND THEN GRADUALLY MOISTURE DEPTH GETS MORE SHALLOW
DURING THE DAY ON TUESDAY. WILL KEEP LIKELY POPS IN THE MOUNTAINS
THROUGH EARLY TUESDAY THEN DIMINISHING LATE IN THE PERIOD. CROSS
SECTIONS INDICATE ANOTHER 2-4 INCHES IN THE MOUNTAINS TONIGHT AND
THEN ANOTHER INCH TUESDAY MORNING. AS FOR THE NORTHEAST
PLAINS...THE GUSTY NORTHWEST WINDS WILL DECREASE THIS EVENING AS
WINDS DECOUPLE FROM THE STRONGER FLOW ALOFT AND WEAK SURGE SHIFTS
WINDS A BIT MORE NORTHERLY. RUC AND GFS HINTS AT SOME LOW QPF
OVER PORTIONS OF THE PLAINS...ESPECIALLY OVER THE PALMER DIVIDE.
GIVEN THE NORTHERLY FLOW WILL KEEP A VERY LOW POP IN THOSE
LOCATIONS BUT NOT OVER THE FRONT RANGE. SKIES WILL CLEAR LATER
TONIGHT BEHIND THIS WEAK WAVE.
.LONG TERM...UPPER TROF AXIS MOVES INTO CENTAL PLAINS TUESDAY
EVENING WITH MODERATE TO STRONG NORTHWEST FLOW ALOFT ACROSS
COLORADO. SUBSIDENCE MID LEVEL SUBSIDENCE TO SPREAD ACROSS AREA
WITH DECREASING MID LEVEL MOISTURE. WITH INCREASING WARM AIR
ADVECTION AND STABILITY...SHOULD SEE MOUNTAIN SNOW SHOWERS END
DURING THE EVENING. MODELS SHOW WEAK MOUNTAIN WAVE DEVELOPING
OVERNIGHT TUESDAY WITH CROSS MOUNTAIN FLOW INCREASING TO AROUND 50
KTS AT MOUNTAIN TOP INTO EARLY WEDNESDAY MORNING. SHOULD CONTINUE
TO BE GUSTY ACROSS THE MOUNTAINS AND HIGHER FOOTHILLS...THOUGH THE
STRONGEST WINDS APPEAR TO REMAIN ACROSS THE HIGHER RIDGES. SPEEDS
SHOULD REMAIN BELOW HIGH WIND CRITERIA. RIDGE AXIS TO MOVE ACROSS
THE STATE WEDNESDAY INTO THURSDAY WITH WESTERLY FLOW ALOFT
BECOMING MORE SOUTHWEST AS UPPER TROUGH MOVES INTO THE GREAT
BASIN. DRY CONDITIONS TO PREVAIL WEDNESDAY AND THURSDAY WITH
TEMPERATURES EXPECTED TO WARM BACK TO SEASONAL NORMALS. FOR
FRIDAY...BOTH DGEX AND ECMWF SHOW UPPER TROUGH MOVING ACROSS
COLORADO WHILE GFS BRINGS TROUGH ACROSS THE STATE FRIDAY EVENING.
AT THIS TIME NOT SURE WHICH SOLUTIONS WILL BE CORRECT...BUT THERE
IS A GENERAL CONSENSUS OF MOISTURE INCREASING ACROSS COLORADO
ALONG WITH SOME MID LEVEL ASCENT. SHOULD BE ENOUGH FOR A CHANCE OF
MOUNTAIN SNOW. DGEX AND ECMWF ALSO GENERATE SOME LIGHT PRECIP
ACROSS SOUTHERN AND FAR EASTERN COLORADO LATE AFTERNOON AND
EVENING. WILL INCLUDE SOME LOW POPS FAR EASTERN ZONES TO ACCOUNT
FOR THIS WITH DRY CONDITIONS ELSEWHERE.
ON SATURDAY...FLOW ALOFT TO BECOME NORTHWEST AS UPPER TROUGH MOVES
ACROSS CENTRAL PLAINS. MODELS SHOW MAINLY DRY AIRMASS OVER
COLORADO...BUT STILL DECENT MOISTURE AND OROGRAPHICS ACROSS
MOUNTAINS TO KEEP SOME SNOW GOING. OTHERWISE DRY CONDITIONS TO
PREVAIL. FOR SUNDAY AND MONDAY...NORTHWEST FLOW ALOFT TO CONTINUE
ENOUGH OROGRAPHIC SUNDAY FOR A SLIGHT CHANCE OF MOUNTAIN SNOW. .
LATEST ECMWF HI RES MODEL HINTS AT A WEAK DISTURBANCE EMBEDDED IN
THE FLOW MOVING ACROSS THE STATE SUNDAY NIGHT AND MONDAY WHICH
MAY HELP INCREASE SNOW CHANCES ACROSS MOUNTAINS AND BRING A
PERHAPS A SLIGHT CHANCE OF SNOW THE THE PLAINS. LATEST DGEX AND
GFS KEEP THINGS DRY MONDAY. FOR NOW WILL LEAN TOWARD THE DRIER
SOLUTIONS OF THE DGEX AND GFS WITH A SLOW WARMING TREND.
&&
.AVIATION...NORTHWEST SURFACE WINDS AT 15-25KT HAVE SURFACED AT
BJC AND APA AND STILL TRYING TO DEVELOP AT KDEN. WILL KEEP THE
IDEA OF SOME BETTER MIXING WITH GUSTY WINDS TO MATERIALIZE AT DEN
FOR A SHORT TIME THROUGH 00Z. FOR TONIGHT A NON DESCRIPT SURFACE
PATTERN WITH A DISORGANIZED FRONT WHICH MAY KEEP SOME WEAK
NORTHERLY FLOW IN THE TERMINALS THROUGH MIDNIGHT BEFORE SLOWLY
RETURNING TO DRAINAGE WINDS LATER IN THE NIGHT. WITH THE MOISTURE
UPSTREAM MAY SEE SOME CEILINGS DIPPING INTO THE 6000-7000 FOOT AGL
RANGE AND MAYBE A BIT LOWER AT APA. WILL STILL KEEP TERMINALS DRY
EXCEPT A VCSH AT APA.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....D-L
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1049 AM MST MON DEC 10 2012
.UPDATE...
&&
.AVIATION...STILL A BIT UNCLEAR HOW THE WINDS WILL BEHAVE THIS
AFTERNOON. WEAK SURGE MOVING THRU NORTHEAST CO WITH A MID LVL
CLOUD DECK WHICH SHOULD SCATTER OUT AROUND 19Z. LOOKS LIKE A WEAK
LONGMONT ANTICYLONE TRYING TO DEVELOP WITH STRONG NW WINDS NEAR
THE WYOMING BORDER AND A WEAK NORTHEAST REFLECTION OF WINDS AT
THIS TIME NORTH OF DENVER. HOWEVER STILL THINK BIT BETTER MIXING
WILL DEVELOP MID AFTERNOON WITH SOME SUN MAKING IT THROUGH WHICH
WILL MIX DOWN SOME OF THE STRONGER NW WINDS. THE NEXT WEAK
IMPULSE ACROSS MONTANA WILL MOVE SOUTHWARD THIS EVENING OVER THE
FRONT RANGE WITH ANOTHER DECK OF CLOUDS. THE RUC INDICATING SOME
LIGHT QPF POSSIBLE OVER THE PALMER DIVIDE. LEFT PRECIP OUT OF
DEN/BJC WITH TOO MUCH DOWNSLOPE BUT APA MAY GET A SHOWERS. WILL
INDICATE A VCSH FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 901 AM MST MON DEC 10 2012/
UPDATE...
SHORT TERM...DECENT WINDS IN THE FRONT RANGE THIS AM BUT LOOKING
AT A DECREASING TREND FOR THE REST OF THIS MORNING AS MOUNTAIN TOP
LEVEL INVERSION BEGINS TO WEAKEN. AS LOW LEVELS MIX OUT A BIT
SHOULD SEE STRONGER NORTHWEST WINDS SPREAD OUT OVER THE PLAINS
THIS AFTERNOON. WILL BEEF UP WINDS SOMEWHAT. APPEARS TO BE SOME
ONGOING SNOW IN THE HIGHER MOUNTAINS VIA WEB CAMS THIS MORNING AND
HAVE ALSO INCREASED POPS IN THE MOUNTAINS AS WELL. NOT LOOKING AT
HILITES FOR NOW AS MOISTURE DEPTH NOT ALL THAT DEEP THROUGH
TONIGHT. CERTAINLY SOME LIGHT ACCUMULATIONS ARE LIKELY. VIA
SATELLITE...LOOKS LIKE TWO DISTINCT WAVES IN THE FLOW...WITH ONE
COMING THRU THE NORTHERN MOUNTAINS THIS MORNING AND ANOTHER ONE
BACK UP OVER WESTERN MONTANA. SO MAY SEE A DECREASE IN THE
SNOWFALL THIS AFTERNOON BEFORE INCREASING A BIT THIS EVENING.
AVIATION...MAIN CHANGE TO UPCOMING TAFS IS TO BEEF UP THE
NORTHWEST WINDS/GUSTS THIS AFTERNOON WITH GUSTS IN THE 20-30KT
RANGE. KDEN WILL BE MOST SUSCEPTIBLE TO THIS AS LOW LEVELS MIX
OUT AND SURFACE GRADIENT REMAINS IN THE 7-9MB RANGE ACROSS THE
STATE THIS AFTERNOON. WILL SEE SOME LOWERING CEILINGS THIS
AFTERNOON WITH INCOMING MOISTURE FROM WYOMING AND MONTANA. MAY GET
START TO GET LOW ENOUGH FOR ILS APPROACH AT DENVER IN THE
6000-7000 FOOT RANGE.
PREV DISCUSSION... /ISSUED 504 AM MST MON DEC 10 2012/
SHORT TERM...UPPER JET SHIFTING EAST WITH MOIST MID LEVEL WARM
ADVECTION THIS MORNING...THEN ANOTHER WEAKER TROUGH MOVES NORTH OF
US AND BRINGS A LITTLE DESTABILIZATION. MID LEVEL NW WINDS WEAKEN
AND BECOME A BIT MORE WESTERLY TODAY...THEN INCREASE AGAIN
TONIGHT. IT WILL BE INTERESTING TO SEE HOW MUCH MIXING THERE IS
TODAY WITH THE WARM ADVECTION OFF THE GROUND AND THE CLOUD COVER.
CURRENT TEMPERATURE FORECAST IS IN THE MIDDLE OF GUIDANCE AND
SEEMS REASONABLE...WITH WARMER READINGS NEAR THE FOOTHILLS WHERE
THERE WILL BE MORE SUN AND WIND...AND HIGHER TERRAIN TO BEGIN
WITH. MORE CLOUD COVER AND LIGHTER WINDS COULD HOLD TEMPERATURES
DOWN AROUND FREEZING ON THE PLAINS. CLOUD COVER MAY THIN
TONIGHT...BUT THERE SHOULD STILL BE SOME AND WEST WINDS SHOULD
ALSO CONTINUE AND KEEP TEMPERATURES UP. WE ARE WARMER THAN
GUIDANCE TONIGHT BUT THAT LOOKS GOOD.
AS FOR MOUNTAIN WINDS...MAYBE A LITTLE WAVE AMPLIFICATION UP
HIGH...BUT STRONG WINDS APPEAR LIMITED TO ABOUT 10 THOUSAND FEET
SO FAR. SOME DOWNWARD PENETRATION IN THE USUAL SPOTS MAINLY WEST
OF BOULDER...BUT ONLY ABOUT 40 MPH GUSTS IN THESE AREAS. STABILITY
STRUCTURE TO SUPPORT AMPLIFICATION SHOULD BE GOING AWAY SOON...SO
THREAT OF STRONG WINDS DOWN INTO THE FOOTHILLS WILL TRANSITION TO
MIXING THIS MORNING...WITH SOME DECREASE IN FLOW PROBABLY
DOMINATING OVER ANY INCREASE IN MIXING THIS AFTERNOON. WINDS COULD
COME UP AGAIN LATE TONIGHT AS ANOTHER JET STREAK MOVES OVER...THIS
ALSO DOES NOT APPEAR TO BE MUCH OF A HIGH WIND THREAT.
MOUNTAIN SNOW WILL LARGELY BE LIMITED BY STABILITY...BUT THERE IS
A PERIOD LATE THIS AFTERNOON AND THIS EVENING WHEN THERE COULD BE
STRONGER VERTICAL MOTIONS. I ADDED A LITTLE MORE SNOW IN THIS TIME
FRAME...BUT IT DOES NOT APPEAR TO NEED AN ADVISORY.
LONG TERM...OVERALL NO SIGNIFICANT ADJUSTMENTS TO THE ONGOING
FORECAST. ON TUESDAY...A STRONG NORTHWESTERLY FLOW ALOFT WILL
REMAIN IN PLACE OVER THE CWFA. A BROAD RIDGE OF HIGH PRESSURE WILL
BE OVER WESTERN COLORADO WITH NOSE OF A 120KT UPPER JET AHEAD OF
IT. THIS FEATURE IS PROGGED TO ADVECT ACROSS NORTHERN COLORADO
THROUGH THE DAY TUESDAY. ONCE THE JETSTREAM SHIFTS TO THE EAST
LATE IN THE DAY TUESDAY...A WEAK MOUNTAIN WAVE DEVELOPS AS
SUBSIDENCE INCREASES AT 700 MB AND THE SHEAR ASSOCIATED WITH THE
PASSAGE OF THE UPPER JET WEAKENS. THE CROSS-MTN COMPONENT LATE
TUESDAY/TUESDAY NIGHT WILL BE AROUND 40 KTS. ALTHOUGH GUSTY WINDS
WILL CONTINUE ESPECIALLY IN THE MOUNTAINS AND HIGHER FOOTHILLS...
NOTHING STRONG ENOUGH IN THE MDL CROSS-SECTIONS TO WARRANT A
HIGHLIGHT YET. AS FOR THE SNOW...INCREASE WARM AIR ADVECTION/STABILITY
WILL ALLOW FOR A DECREASE CHANCE OF SNOW TUESDAY INTO TUESDAY
EVENING. WEDNESDAY AND THURSDAY...THE RIDGE AXIS PASSES ACROSS THE
STATE AND THE FLOW ALOFT GOES FM WLY ON WEDNESDAY TO SOUTHWESTERLY
ON THURSDAY. IT WILL BE DRY BOTH DAYS WITH TEMPERATURES PROGGED TO
CLIMB BACK TO NEAR SEASONAL NORMALS. FOR FRIDAY THROUGH SUNDAY...
MOISTURE WILL INCREASE OVER COLORADO AS THE NEXT STORM SYSTEM
APPROACHES FM THE SOUTHWEST. THIS SYSTEM COULD PASS ACROSS SRN
COLORADO LATE FRIDAY...WITH MORE RIDGING ON SATURDAY...THEN
ANOTHER WEAK TROUGH IS PROGGED TO PASS ACROSS THE STATE ON SUNDAY.
TEMPERATURES WILL COOL OFF BY THAT TIME WITH A CHANCE OF SNOW
RETURNING TO THE MOUNTAINS...AND POSSIBLY EVEN THE NORTHEAST
PLAINS. TOO FAR INTO THE FUTURE TO ADDRESS MORE THAN A CHANCE POPS
IN THE MOUNTAINS AT THIS POINT.
AVIATION...VFR CONDITIONS THROUGH TONIGHT. KDEN/KAPA WILL HAVE
WEST TO NORTHWEST WINDS MIXING DOWN BY MIDDAY...BUT SPEEDS SHOULD
BE LESS THAN 20 KNOTS. KBJC MAY HAVE STRONGER GUSTS THIS MORNING.
CLOUDS WILL LOWER WITH INCREASING MOISTURE THIS AFTERNOON AND
THERE IS A SLIGHT CHANCE OF CEILINGS LOW ENOUGH TO REQUIRE
INSTRUMENT APPROACHES TO KDEN AT TIMES...BUT MORE LIKELY CEILINGS
WILL BE OVER 7000 FT AGL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....COOPER
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION...UPDATED
NWS MELBOURNE FL
243 PM EST MON DEC 10 2012
.DISCUSSION...
...CHANCE FOR STRONG STORMS AND HEAVY RAINFALL NEXT FEW DAYS...
CURRENTLY/REST OF THE AFTERNOON...A PERIOD OF HEATING HAS OCCURRED
ACROSS SOUTHERN SECTIONS THIS AFTERNOON. SOME LOW LEVEL SHEAR EXISTS...
SO WILL HAVE TO WATCH FOR A FEW STRONG STORMS THROUGH ABOUT
SUNSET.
TONIGHT-TUE...VORT MAX WITH ASSOCIATED CONVECTION IN THE EASTERN
GULF WILL SWEEP ACROSS THE PENINSULA THIS EVENING AND WELL
NORTHEAST OF THE AREA BY TUE MORNING. VERY HIGH MOISTURE VALUES...
NEAR 2 INCHES PRECIPITABLE WATER...WILL BE IN PLACE AS THIS
FEATURE MOVES ACROSS. THIS WILL BRING RATHER HIGH RAIN CHANCES FOR
MOST OF THE AREA THROUGH THE REMAINDER OF THE DAY. MOS POPS ARE
60-80 PERCENT AREAWIDE BUT HAVE SETTLED IN AT 60-70 PERCENT
TONIGHT.
SOME LOCAL HEAVY RAIN IS EXPECTED ALONG WITH ISOLATED STORMS...
ESPECIALLY NEAR THE VORT MAX AS IT MOVES ACROSS THE PENINSULA
THIS EVENING.
THE OTHER WEATHER ELEMENT TO WATCH OUT FOR IS LATE NIGHT LOW
STRATUS...WHICH COULD EVOLVE INTO A FRONTAL FOG EVENT. MOS HAS
VERY LOW CEILINGS/VISIBILITIES...SO WILL STAY WITH PREVIOUS
FORECAST WHICH KEEPS A MENTION OF PATCHY FOG OVERNIGHT. MAY NEED
TO HIT THE FOG HARDER IN SUBSEQUENT UPDATES.
THE GFS SHOWS SOME SUPPRESSING EFFECT BEHIND THE VORT MAX AND
LOWERS POPS ON TUE TO 30-40 PERCENT. THAT IS A BIT TOO MUCH OF A
RUN TO RUN CHANGE...ESPECIALLY SINCE A WEAK FRONTAL BOUNDARY WILL
BE APPROACHING THE AREA. WILL GO WITH 50 PERCENT POPS ACROSS THE
BOARD FOR NOW. INCREASING DEEP LAYER SHEAR MAY HELP TO LEND SOME
ORGANIZATION TO CONVECTION...BUT THE AMOUNT OF DESTABILIZATION IS
QUESTIONABLE DUE TO LINGERING LOW CLOUDS IN THE MORNING AND
CONVECTIVE DEBRIS CLOUDS.
00Z WED-12Z THU...
WET WX PATTERN CONTINUES FOR CNTRL FL AS THE LOW/MID LEVEL RIDGE
OVER THE FL STRAITS/NW CARIB INTERACTS WITH THE SLOW MOVING FRONTAL
TROF PUSHING THRU THE DEEP S. THE RESULTING DEEP S/SW FLOW ACRS THE
REGION WILL CONTINUE TO PULL TROPICAL MOISTURE UP FROM THE CARIB.
PWAT VALUES EXPECTED TO REACH AS HIGH AS FROM 1.8"-2.0" THRU 00Z TUE
BEFORE DRIER AIR BEGINS TO ADVECT INTO THE PENINSULA.
DEEP SW FLOW REGIMES OFTEN GENERATE MODERATE TO STRONG ISENTROPIC
LIFT...ESP IN THE PRESENCE OF AN APPROACHING COLD FRONT. THIS CASE
WILL BE NO EXCEPTION AS FRONTAL BNDRY SLOWS AND STALLS ACRS THE N FL
PENINSULA ON TUE. SFC BASED INSTABILITY WILL BE PRESENT IN THE FORM
OF M60S/L70S SFC DEWPOINTS AND MAX TEMPS 5-10F ABV AVG...MIN TEMPS
10-15 ABV AVG.
LATEST RAP ANALYSIS SHOWS UPSTREAM MID LVL LAPSE RATES ARE
UNIMPRESSIVE...LARGELY BTWN 5.5-6.0C/KM. HOWEVER...EXPECT TO SEE
THESE STEEPEN AS THE FRONTAL TROF PUSHES ACRS THE GOMEX...
ACCOMPANIED BY AN H85-H70 THERMAL TROF. UPR LVL DIVERGENCE ALSO MAY
INCREASE AS A THE RIGHT REAR QUAD OF A LARGE H25 LIFTING JET...
EXTENDING FROM THE CANADIAN MARITIMES TO THE RIO GRANDE VALLEY...
PUSHES EAST AND COUPLES WITH A 100KT JET CORE CURRENTLY PASSING
SOUTH OF THE BAJA PENINSULA.
COMBINATION OF MID/UPR LVL FORCING AND LOW LVL BUOYANCY SHOULD
SUPPORT SCT/NMRS SHRAS AND ISOLD/SCT TSRAS ACROSS THE REGION.
INCREASED POPS TO 60-70PCT TUE NIGHT THRU WED...40-60 POPS LINGERING
INTO WED NIGHT. BUMPED THU POPS UP ABOUT 10PCT AS WELL AS LATEST
MODEL RUN SHOWS DEEP MOISTURE LINGERING THRU 18Z. MIDDAY THU CUTOFF
TIME LOOKS GOOD.
SPC KEEPS CNTRL FL UNDER A SLIGHT RISK FOR SVR WX BTWN 00Z-12Z
WED...GENERAL THUNDER 12Z WED THRU 12Z THU WITH THE HIGHEST STORM
POTENTIAL DVLPG IN THE VCNTY OF THE FRONTAL BNDRY ITSELF. FLOODING
CONCERNS MINIMAL...HOWEVER...WITH ANNUAL PRECIP DEFICITS RANGING
FROM 2" TO 12".
THU-SAT...(MODIFIED PREV DISC)
ROBUST SHORTWAVE SWINGS THROUGH THE LOWER MS VALLEY THEN THROUGH THE
SE US BY THURSDAY MORNING...DEVELOPING A SFC LOW OFF THE FL EAST
COAST ALONG THE STALLED BOUNDARY AND DRIVING IT THROUGH THE STATE
AROUND MIDDAY THURSDAY. WILL KEEP THE MENTION ISOLD/SCT SHOWERS
ACROSS THE TREASURE COAST AND LOCAL ATLANTIC THROUGH MID DAY ON
THURSDAY.
THE SURFACE HIGH BEHIND THE FRONT WILL QUICKLY STRING OUT ACROSS THE
DEEP SOUTH AND WESTERN ATLANTIC BY THE END OF THE WEEK...BRINGING
THE FLOW AROUND TO THE EAST BY FRIDAY AND MODERATING ANY
POST-FRONTAL COOLDOWN. BOTH MODELS SHOW ENOUGH LINGERING MOISTURE
THAT ONSHORE MOVING COASTAL SHOWERS MAY BE A POSSIBILITY BY FRIDAY
NIGHT INTO SATURDAY.
&&
.AVIATION...
AN AREA OF SHOWERS WITH A FEW STORMS IS EXPECTED TO MOVE ACROSS
THE PENINSULA LATE THIS AFTERNOON AND THROUGH THE EVENING HOURS.
DID NOT HIT THIS REAL HARD IN THE TAFS YET...JUST PUTTING
PREVAILING LIGHT RAIN WITH TEMPORARY MVFR. EXPECT SOME TWEAKING TO
THE TIMING AND LOWERING OF THE CEILINGS AND VISIBILITIES FOR SEVERAL
TERMINALS.
ONCE THE PRECIP MOVES ON BY TO THE NORTHEAST AFTER MIDNIGHT...THERE
WILL BE SOME STRATUS DEVELOPING...WHICH COULD LEAD TO LIFR
CONDITIONS. AGAIN...DID NOT HIT THIS QUITE AS HARD AS THE LATEST
MOS GUIDANCE SHOWS...BUT WITH VERY SOUPY AIR MASS...WE MAY EVOLVE
INTO A FRONTAL FOG TYPE SCENARIO THAT LASTS INTO THE MID-LATE
MORNING ON TUE.
&&
.MARINE...
TONIGHT-TUE...THE GFS SHOWS SOME CONVECTIVE ENHANCEMENT TO THE
WIND FIELDS TONIGHT...SO HAVE CAPPED THEM AT 15-20 KNOTS. WILL
START OFF WITH AN EXERCISE CAUTION STATEMENT FOR ALL BUT THE
NORTHERN NEARSHORE ZONE. EXPECT AT LEAST ISOLATED STORMS TO MOVE
ACROSS THE WATERS...MAINLY IN THE 00Z-06Z TIME PERIOD. A FEW COULD
BE STRONG...ESPECIALLY OVER THE GULF STREAM.
THE MODELS WEAKEN THE PRESSURE GRADIENT A LITTLE ON TUE AS A
WEAK FRONTAL BOUNDARY APPROACHES. MARINERS WILL NEED TO BE ALERT
FOR CONVECTIVE DEVELOPMENT OVER LAND AREAS MOVING OFFSHORE...MAINLY
IN THE AFTERNOON.
THU-FRI (PREVIOUS DISCUSSION)...FRONT MAKES IT THROUGH THE STATE
WEDNESDAY NIGHT INTO THURSDAY...WITH A BRIEF NORTHERLY WIND SURGE
BEHIND THE PASSAGE BRINGING WINDS AROUND 20KTS THROUGH MIDDAY
THURSDAY BEFORE DROPPING TO 15-20KTS AND VEERING NORTHEAST INTO
THURSDAY NIGHT.
THE SURFACE HIGH WILL PUSH ACROSS THE DEEP SOUTH AND OFF THE MID
ATLC COAST THRU THE END OF THE WORK WEEK...BRINGING WINDS AROUND TO
THE EAST FOR FRIDAY THROUGH THE END OF THE WEEK AT AROUND 10-15KTS.
POST FRONTAL WIND SURGE WILL BRING WINDS UP TO 7-8FT OFFSHORE
THROUGH FRIDAY.
SAT...LATEST MODEL FORECASTS SHOW HIGH PRESSURE RIDGE GETTING CLOSER
TO THE AREA...SO WINDS SHOULD DROP OFF TO 10 KNOTS OR LESS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 67 80 64 75 / 70 50 60 70
MCO 66 83 63 79 / 70 50 60 70
MLB 68 82 68 79 / 70 50 70 70
VRB 71 83 67 79 / 60 50 70 70
LEE 65 80 61 75 / 60 50 60 70
SFB 66 81 63 77 / 70 50 60 70
ORL 67 82 63 78 / 70 50 60 70
FPR 70 83 67 79 / 60 50 70 70
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...LASCODY
LONG TERM....BRAGAW
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
415 PM CST MON DEC 10 2012
.DISCUSSION...
302 PM CST
SURFACE TROUGH EXTENDS WEST-EAST FROM ABOUT KRPJ TO KMDW AND OVER
INTO BERRIEN COUNTY MICHIGAN PER 20Z ANALYSIS. SCATTERED SNOW
SHOWERS HAVE BEEN CONFINED TO THE VICINITY OF THE TROUGH AXIS FOR
THE MOST PART THIS AFTERNOON...WITH SOMEWHAT HEAVIER SNOW SHOWERS
OVER LAKE MICHIGAN EXTENDING INTO FAR NORTHEAST PORTER AND LAPORTE
COUNTIES. WHILE A FEW OF THE SNOW SHOWERS OVER NORTHERN IL HAVE
PRODUCED RADAR RETURNS NEAR 35 DBZ AT TIMES...IT APPEARS THE
POTENTIAL FOR PICKING UP ANY MEASURABLE SNOW OF ANY SIGNIFICANCE IS
QUITE LOW. WITH THE BOUNDARY SAFELY SOUTH OF BOTH RFD AND ORD...AND
BOTH LOCATIONS ONLY PICKING UP TRACE AMOUNTS OF SNOW TODAY...IT
LOOKS AS IF THE STREAK OF DAYS WITHOUT MEASURABLE SNOW WILL CONTINUE
PAST 280 DAYS! THUS UNLESS SOMETHING ODD OCCURS...CHICAGO WILL VERY
LIKELY SET A NEW RECORD OF 281 CONSECUTIVE DAYS WITHOUT MEASURABLE
SNOW.
AS COLDER AIR CONTINUES TO SPREAD ACROSS LAKE MICHIGAN THIS
EVENING...LAKE EFFECT SNOW SHOWERS SHOULD BECOME MORE ORGANIZED WITH
NORTH-SOUTH BANDING DEVELOPING OVER MID AND EASTERN LAKE MICHIGAN.
LATEST HIGH-RES GUIDANCE INCLUDING WRF-NMM...WRF-NAM AND RAP RUNS
ALL SUGGEST THAT PORTIONS OF PORTER COUNTY MAY SEE A BRIEF PERIOD OF
LAKE EFFECT INTO THIS EVENING...BEFORE BOUNDARY LAYER WINDS BACK
MORE WESTERLY AFTER MIDNIGHT AND PUSH THE LOW LEVEL CONVERGENT FOCUS
EAST TOWARD THE MICHIGAN SHORE. CURRENT LAKE-ENHANCED BAND OVER FAR
SOUTHERN LAKE MICHIGAN HAS PRODUCED VISIBILITY AS LOW AS 1/2SM-1/4SM
AT SOUTH BEND IN THE LAST HOUR OR SO...AN INDICATION THAT SOME
RELATIVELY HEAVY SNOW MAY FALL FOR AT LEAST A SHORT TIME. 850 HPA
TEMPS COOLING TO AROUND -9C...AND RESULTING LAKE-850 HPA DELTA T
VALUES AROUND 16/17C WOULD POTENTIALLY SUPPORT 1-3/2-4 INCHES IF IT
WERE ABLE TO FOCUS ON A LOCALE FOR A FEW HOURS. GIVEN TRANSIENT
NATURE AND RELATIVELY SHORT DURATION EXPECTED FOR BAND TO REALLY
FOCUS ON NORTHEAST PORTER COUNTY...WOULD THINK THAT THE LOWER END OF
THIS RANGE IS MORE LIKELY THROUGH MIDNIGHT TONIGHT. AGAIN...SNOW
SHOULD END FOR PORTER COUNTY BY 06-09Z TONIGHT AS THE FOCUS DRIFTS
EAST OF THE AREA.
OTHERWISE...CONSIDERABLE AREA OF STRATUS/STRATOCU NOTED PER
AFTERNOON VISIBLE SATELLITE IMAGERY WITHIN LOW LEVEL COLD ADVECTION
BENEATH BROAD UPPER TROUGH WITH SERIES OF WEAK VORTS TRANSITING THE
REGION THROUGH TUESDAY. CLOUDS/FEW FLURRIES THIS AFTERNOON SHOULD
GRADUALLY TRANSITION TO PARTLY CLOUDY CONDITIONS FROM THE WEST LATE
TONIGHT/EARLY TUESDAY...WITH LARGE SCALE UPPER TROUGH AXIS FINALLY
MOVING EAST OF THE AREA TUESDAY NIGHT. BROAD...FLAT UPPER RIDGING
THEN BUILDS ACROSS THE GREAT LAKES AND SOUTHEAST WEDNESDAY/THURSDAY
WITH A PERIOD OF DRY AND SLOWLY MODERATING WEATHER.
NEXT WEATHER MAKER TO MONITOR IS AN UPPER TROUGH CURRENTLY
PROPAGATING ACROSS THE GULF OF ALASKA. MEDIUM RANGE GUIDANCE REMAINS
CONSISTENT IN DIGGING THIS SYSTEM SOUTH ALONG THE WEST COAST THROUGH
MID-WEEK...DEVELOPING INTO A CLOSED LOW ALONG THE CALIFORNIA COAST
BY LATE THURSDAY. THIS SYSTEM IS THEN PROGGED TO MOVE OUT ACROSS THE
PLAINS FRIDAY/FRIDAY NIGHT AND ACROSS OUR REGION SATURDAY. THERE
REMAINS SOME MODEL SPREAD WITH THE TRACK OF THE LOW ACROSS
MISSOURI/ILLINOIS BY SATURDAY...BUT THATS TO BE EXPECTED AT THIS
DISTANCE ESPECIALLY WITH LOWS EJECTING FROM THE SOUTHWESTERN STATES.
BOTH THE ECMWF AND GFS RUNS ARE A LITTLE FARTHER SOUTH THAN THOSE
FROM 24 HOURS AGO...THOUGH STILL APPEARS TO BE MAINLY A WARM/RAIN
EVENT FOR THE FORECAST AREA. CONTINUED TO FAVOR THE CONSISTENT ECMWF
SOLUTION FOR TIMING OF PRECIP/PRECIP TYPE FRIDAY NIGHT THROUGH
SATURDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* GENERALLY MVFR CIGS THROUGH LATE TONIGHT
* GUSTY SOUTHWEST WINDS TUESDAY
IZZI
//DISCUSSION...UPDATED 20Z...
COLD AIR MASS MOVING OVER AREA THAT HAD CLEARED OUT OVER SOUTHERN
WISCONSIN RESULTED IN MVFR CIGS FILLING BACK IN...SO NOW EXPECT
MVFR CIGS TO LINGER THROUGH LATE TONIGHT BEFORE POSSIBLE
SCATTERING OUT TOWARD DAYBREAK. THERE MAY BE SOME GRADUAL LOWERING
OF CIG HEIGHT AFTER DARK...BUT NOT EXPECTING PREVAILING CIGS
BELOW 1500 FT AT TAF SITES. CANT RULE OUT SCT FLURRIES FROM TIME
TO TIME...BUT NO OPERATIONAL IMPACT.
FROM 18Z...
FRONTAL BOUNDARY CURRENTLY PUSHING THROUGH CHICAGO TERMINALS WITH
MVFR VSBY IN -SN AT MDW AS OF THIS WRITING. SNOW SHOWERS AND
SIMILAR VSBY RESTRICTION EXPECTED AS BOUNDARY PUSHES SOUTH THROUGH
GYY AND TERMINALS SOUTH OF CHICAGO AREA...WITH FLURRIES/SHSN
ENDING FROM NORTH BEHIND BOUNDARY AND WINDS TURNING NORTHWEST.
CLEARING HOLE IN SATELLITE OVER WISCONSIN CONTINUES TO PUSH
SOUTHWARD AS WELL...WITH A PERIOD OF MVFR CIGS BEFORE SCATTERING
OUT TO VFR AT LEAST BRIEFLY. CONCERN THAT CLEARING HOLE IS SHOWING
SIGNS OF FILLING BACK IN WITH MVFR CIGS AND COMBINING WITH ANOTHER
AREA OF MVFR CIGS DROPPING SOUTHWARD FROM NORTHERN WISCONSIN...SO
WILL ASSESS AND MAY NEED TO INCLUDE AN MVFR CIG IN 20Z UPDATE.
WINDS WILL DIMINISH AND BECOME LIGHT WEST LATE TONIGHT AND THEN
SOUTHWEST BEFORE DAYBREAK AS HIGH PRESSURE RIDGE SETTLES SOUTH OF
AREA. PRESSURE GRADIENT WILL TIGHTEN MID DAY TUESDAY AS A LOW
PRESSURE SYSTEM TRACKS NORTH OF GREAT LAKES...CAUSING SOUTHWEST
WINDS AT 220-240 DEG DIRECTION TO INCREASE. FORECAST SOUNDINGS
SUGGEST POTENTIAL FOR GUSTS IN THE UPPER TEENS TO AROUND 20 KT
THROUGH EARLY EVENING TOMORROW BEFORE MIXING DIMINISHES.
RC
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN GENERALLY MVFR CIGS BUT SOME FLUCTUATIONS TO
VFR POSSIBLE
* MEDIUM CONFIDENCE IN TIMING OF CLEARING LATE TONIGHT
* HIGH CONFIDENCE IN OTHER FORECAST ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH FRIDAY...VFR. WX NIL.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...CHANCE OF RAIN. MVFR/IFR
CONDITIONS POSSIBLE.
SUNDAY...CHANCE OF RAIN...SNOW MIX. MVFR/IFR CONDITIONS POSSIBLE.
KREIN
&&
.MARINE...
313 PM CST
N AND NE WINDS WILL DIMINISH TONIGHT AS LOW PRESSURE IN SW QUEBEC
MOVES E TO THE GULF OF SAINT LAWRENCE OVERNIGHT ALLOWING HIGH
PRESSURE OVER ONTARIO TO DROP SSE TO THE LOWER GREAT LAKES. S AND
SW WINDS WILL BE ON THE INCREASE TUE AS THE HIGH MERGES WITH
ANOTHER HIGH PRESSURE RIDGE OVER THE SOUTHERN PLAINS...OZARKS AND
LOWER OH VALLEY. WINDS SLACKEN AGAIN OVERNIGHT TUE BEFORE
FRESHENING AGAIN DURING WED AS LOW PRESSURE IN THE NORTHERN HIGH
PLAINS ELONGATES ACROSS THE UPPER MIDWEST INTO ONTARIO BY THU.
WINDS MAY REACH GALE FORCE BY WED NIGHT ON NORTHERN LAKE MI...AND
PERSIST INTO THU. THE LOW PRESSURE TROUGH DROPS S ACROSS THE GREAT
LAKES FRI WHILE LOW PRESSURE DEEPENS AS IT MOVES E FROM THE
CENTRAL ROCKIES TO THE CENTRAL PLAINS FRI AND FRI NIGHT. THIS LOW
TURNS NE TO THE MID MS VALLEY SAT AND MOVES INTO THE UPPER GREAT
LAKES SAT NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
314 PM CST MON DEC 10 2012
.DISCUSSION...
302 PM CST
SURFACE TROUGH EXTENDS WEST-EAST FROM ABOUT KRPJ TO KMDW AND OVER
INTO BERRIEN COUNTY MICHIGAN PER 20Z ANALYSIS. SCATTERED SNOW
SHOWERS HAVE BEEN CONFINED TO THE VICINITY OF THE TROUGH AXIS FOR
THE MOST PART THIS AFTERNOON...WITH SOMEWHAT HEAVIER SNOW SHOWERS
OVER LAKE MICHIGAN EXTENDING INTO FAR NORTHEAST PORTER AND LAPORTE
COUNTIES. WHILE A FEW OF THE SNOW SHOWERS OVER NORTHERN IL HAVE
PRODUCED RADAR RETURNS NEAR 35 DBZ AT TIMES...IT APPEARS THE
POTENTIAL FOR PICKING UP ANY MEASURABLE SNOW OF ANY SIGNIFICANCE IS
QUITE LOW. WITH THE BOUNDARY SAFELY SOUTH OF BOTH RFD AND ORD...AND
BOTH LOCATIONS ONLY PICKING UP TRACE AMOUNTS OF SNOW TODAY...IT
LOOKS AS IF THE STREAK OF DAYS WITHOUT MEASURABLE SNOW WILL CONTINUE
PAST 280 DAYS! THUS UNLESS SOMETHING ODD OCCURS...CHICAGO WILL VERY
LIKELY SET A NEW RECORD OF 281 CONSECUTIVE DAYS WITHOUT MEASURABLE
SNOW.
AS COLDER AIR CONTINUES TO SPREAD ACROSS LAKE MICHIGAN THIS
EVENING...LAKE EFFECT SNOW SHOWERS SHOULD BECOME MORE ORGANIZED WITH
NORTH-SOUTH BANDING DEVELOPING OVER MID AND EASTERN LAKE MICHIGAN.
LATEST HIGH-RES GUIDANCE INCLUDING WRF-NMM...WRF-NAM AND RAP RUNS
ALL SUGGEST THAT PORTIONS OF PORTER COUNTY MAY SEE A BRIEF PERIOD OF
LAKE EFFECT INTO THIS EVENING...BEFORE BOUNDARY LAYER WINDS BACK
MORE WESTERLY AFTER MIDNIGHT AND PUSH THE LOW LEVEL CONVERGENT FOCUS
EAST TOWARD THE MICHIGAN SHORE. CURRENT LAKE-ENHANCED BAND OVER FAR
SOUTHERN LAKE MICHIGAN HAS PRODUCED VISIBILITY AS LOW AS 1/2SM-1/4SM
AT SOUTH BEND IN THE LAST HOUR OR SO...AN INDICATION THAT SOME
RELATIVELY HEAVY SNOW MAY FALL FOR AT LEAST A SHORT TIME. 850 HPA
TEMPS COOLING TO AROUND -9C...AND RESULTING LAKE-850 HPA DELTA T
VALUES AROUND 16/17C WOULD POTENTIALLY SUPPORT 1-3/2-4 INCHES IF IT
WERE ABLE TO FOCUS ON A LOCALE FOR A FEW HOURS. GIVEN TRANSIENT
NATURE AND RELATIVELY SHORT DURATION EXPECTED FOR BAND TO REALLY
FOCUS ON NORTHEAST PORTER COUNTY...WOULD THINK THAT THE LOWER END OF
THIS RANGE IS MORE LIKELY THROUGH MIDNIGHT TONIGHT. AGAIN...SNOW
SHOULD END FOR PORTER COUNTY BY 06-09Z TONIGHT AS THE FOCUS DRIFTS
EAST OF THE AREA.
OTHERWISE...CONSIDERABLE AREA OF STRATUS/STRATOCU NOTED PER
AFTERNOON VISIBLE SATELLITE IMAGERY WITHIN LOW LEVEL COLD ADVECTION
BENEATH BROAD UPPER TROUGH WITH SERIES OF WEAK VORTS TRANSITING THE
REGION THROUGH TUESDAY. CLOUDS/FEW FLURRIES THIS AFTERNOON SHOULD
GRADUALLY TRANSITION TO PARTLY CLOUDY CONDITIONS FROM THE WEST LATE
TONIGHT/EARLY TUESDAY...WITH LARGE SCALE UPPER TROUGH AXIS FINALLY
MOVING EAST OF THE AREA TUESDAY NIGHT. BROAD...FLAT UPPER RIDGING
THEN BUILDS ACROSS THE GREAT LAKES AND SOUTHEAST WEDNESDAY/THURSDAY
WITH A PERIOD OF DRY AND SLOWLY MODERATING WEATHER.
NEXT WEATHER MAKER TO MONITOR IS AN UPPER TROUGH CURRENTLY
PROPAGATING ACROSS THE GULF OF ALASKA. MEDIUM RANGE GUIDANCE REMAINS
CONSISTENT IN DIGGING THIS SYSTEM SOUTH ALONG THE WEST COAST THROUGH
MID-WEEK...DEVELOPING INTO A CLOSED LOW ALONG THE CALIFORNIA COAST
BY LATE THURSDAY. THIS SYSTEM IS THEN PROGGED TO MOVE OUT ACROSS THE
PLAINS FRIDAY/FRIDAY NIGHT AND ACROSS OUR REGION SATURDAY. THERE
REMAINS SOME MODEL SPREAD WITH THE TRACK OF THE LOW ACROSS
MISSOURI/ILLINOIS BY SATURDAY...BUT THATS TO BE EXPECTED AT THIS
DISTANCE ESPECIALLY WITH LOWS EJECTING FROM THE SOUTHWESTERN STATES.
BOTH THE ECMWF AND GFS RUNS ARE A LITTLE FARTHER SOUTH THAN THOSE
FROM 24 HOURS AGO...THOUGH STILL APPEARS TO BE MAINLY A WARM/RAIN
EVENT FOR THE FORECAST AREA. CONTINUED TO FAVOR THE CONSISTENT ECMWF
SOLUTION FOR TIMING OF PRECIP/PRECIP TYPE FRIDAY NIGHT THROUGH
SATURDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* ANY BRIEF VFR/HIGHER END MVFR TO LOWER BACK TO CIGS BETWEEN 015
AND 020 THROUGH THIS EVENING.
* GUSTY SOUTHWEST WINDS 220-240 DEG ON TUESDAY...WITH GUSTS
POSSIBLY UP TO 20 KT.
RC
//DISCUSSION...UPDATED 20Z...
COLD AIR MASS MOVING OVER AREA THAT HAD CLEARED OUT OVER SOUTHERN
WISCONSIN RESULTED IN MVFR CIGS FILLING BACK IN...SO NOW EXPECT
MVFR CIGS TO LINGER THROUGH LATE TONIGHT BEFORE POSSIBLE
SCATTERING OUT TOWARD DAYBREAK. THERE MAY BE SOME GRADUAL LOWERING
OF CIG HEIGHT AFTER DARK...BUT NOT EXPECTING PREVAILING CIGS
BELOW 1500 FT AT TAF SITES. CANT RULE OUT SCT FLURRIES FROM TIME
TO TIME...BUT NO OPERATIONAL IMPACT.
FROM 18Z...
FRONTAL BOUNDARY CURRENTLY PUSHING THROUGH CHICAGO TERMINALS WITH
MVFR VSBY IN -SN AT MDW AS OF THIS WRITING. SNOW SHOWERS AND
SIMILAR VSBY RESTRICTION EXPECTED AS BOUNDARY PUSHES SOUTH THROUGH
GYY AND TERMINALS SOUTH OF CHICAGO AREA...WITH FLURRIES/SHSN
ENDING FROM NORTH BEHIND BOUNDARY AND WINDS TURNING NORTHWEST.
CLEARING HOLE IN SATELLITE OVER WISCONSIN CONTINUES TO PUSH
SOUTHWARD AS WELL...WITH A PERIOD OF MVFR CIGS BEFORE SCATTERING
OUT TO VFR AT LEAST BRIEFLY. CONCERN THAT CLEARING HOLE IS SHOWING
SIGNS OF FILLING BACK IN WITH MVFR CIGS AND COMBINING WITH ANOTHER
AREA OF MVFR CIGS DROPPING SOUTHWARD FROM NORTHERN WISCONSIN...SO
WILL ASSESS AND MAY NEED TO INCLUDE AN MVFR CIG IN 20Z UPDATE.
WINDS WILL DIMINISH AND BECOME LIGHT WEST LATE TONIGHT AND THEN
SOUTHWEST BEFORE DAYBREAK AS HIGH PRESSURE RIDGE SETTLES SOUTH OF
AREA. PRESSURE GRADIENT WILL TIGHTEN MID DAY TUESDAY AS A LOW
PRESSURE SYSTEM TRACKS NORTH OF GREAT LAKES...CAUSING SOUTHWEST
WINDS AT 220-240 DEG DIRECTION TO INCREASE. FORECAST SOUNDINGS
SUGGEST POTENTIAL FOR GUSTS IN THE UPPER TEENS TO AROUND 20 KT
THROUGH EARLY EVENING TOMORROW BEFORE MIXING DIMINISHES.
RC
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN MVFR CIGS THROUGH THIS EVENING...WITH CURRENT
BRIEF VFR AT MDW EXPECTED TO LOWER BACK TO MVFR SHORTLY.
* MEDIUM TO HIGH CONFIDENCE CIGS WILL REMAIN ABOVE 1500 FT.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS.
RC
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH FRIDAY...VFR. WX NIL.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...CHANCE OF RAIN. MVFR/IFR
CONDITIONS POSSIBLE.
SUNDAY...CHANCE OF RAIN...SNOW MIX. MVFR/IFR CONDITIONS POSSIBLE.
KREIN
&&
.MARINE...
313 PM CST
N AND NE WINDS WILL DIMINISH TONIGHT AS LOW PRESSURE IN SW QUEBEC
MOVES E TO THE GULF OF SAINT LAWRENCE OVERNIGHT ALLOWING HIGH
PRESSURE OVER ONTARIO TO DROP SSE TO THE LOWER GREAT LAKES. S AND
SW WINDS WILL BE ON THE INCREASE TUE AS THE HIGH MERGES WITH
ANOTHER HIGH PRESSURE RIDGE OVER THE SOUTHERN PLAINS...OZARKS AND
LOWER OH VALLEY. WINDS SLACKEN AGAIN OVERNIGHT TUE BEFORE
FRESHENING AGAIN DURING WED AS LOW PRESSURE IN THE NORTHERN HIGH
PLAINS ELONGATES ACROSS THE UPPER MIDWEST INTO ONTARIO BY THU.
WINDS MAY REACH GALE FORCE BY WED NIGHT ON NORTHERN LAKE MI...AND
PERSIST INTO THU. THE LOW PRESSURE TROUGH DROPS S ACROSS THE GREAT
LAKES FRI WHILE LOW PRESSURE DEEPENS AS IT MOVES E FROM THE
CENTRAL ROCKIES TO THE CENTRAL PLAINS FRI AND FRI NIGHT. THIS LOW
TURNS NE TO THE MID MS VALLEY SAT AND MOVES INTO THE UPPER GREAT
LAKES SAT NIGHT.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
302 PM CST MON DEC 10 2012
.DISCUSSION...
302 PM CST
SURFACE TROUGH EXTENDS WEST-EAST FROM ABOUT KRPJ TO KMDW AND OVER
INTO BERRIEN COUNTY MICHIGAN PER 20Z ANALYSIS. SCATTERED SNOW
SHOWERS HAVE BEEN CONFINED TO THE VICINITY OF THE TROUGH AXIS FOR
THE MOST PART THIS AFTERNOON...WITH SOMEWHAT HEAVIER SNOW SHOWERS
OVER LAKE MICHIGAN EXTENDING INTO FAR NORTHEAST PORTER AND LAPORTE
COUNTIES. WHILE A FEW OF THE SNOW SHOWERS OVER NORTHERN IL HAVE
PRODUCED RADAR RETURNS NEAR 35 DBZ AT TIMES...IT APPEARS THE
POTENTIAL FOR PICKING UP ANY MEASURABLE SNOW OF ANY SIGNIFICANCE IS
QUITE LOW. WITH THE BOUNDARY SAFELY SOUTH OF BOTH RFD AND ORD...AND
BOTH LOCATIONS ONLY PICKING UP TRACE AMOUNTS OF SNOW TODAY...IT
LOOKS AS IF THE STREAK OF DAYS WITHOUT MEASURABLE SNOW WILL CONTINUE
PAST 280 DAYS! THUS UNLESS SOMETHING ODD OCCURS...CHICAGO WILL VERY
LIKELY SET A NEW RECORD OF 281 CONSECUTIVE DAYS WITHOUT MEASURABLE
SNOW.
AS COLDER AIR CONTINUES TO SPREAD ACROSS LAKE MICHIGAN THIS
EVENING...LAKE EFFECT SNOW SHOWERS SHOULD BECOME MORE ORGANIZED WITH
NORTH-SOUTH BANDING DEVELOPING OVER MID AND EASTERN LAKE MICHIGAN.
LATEST HIGH-RES GUIDANCE INCLUDING WRF-NMM...WRF-NAM AND RAP RUNS
ALL SUGGEST THAT PORTIONS OF PORTER COUNTY MAY SEE A BRIEF PERIOD OF
LAKE EFFECT INTO THIS EVENING...BEFORE BOUNDARY LAYER WINDS BACK
MORE WESTERLY AFTER MIDNIGHT AND PUSH THE LOW LEVEL CONVERGENT FOCUS
EAST TOWARD THE MICHIGAN SHORE. CURRENT LAKE-ENHANCED BAND OVER FAR
SOUTHERN LAKE MICHIGAN HAS PRODUCED VISIBILITY AS LOW AS 1/2SM-1/4SM
AT SOUTH BEND IN THE LAST HOUR OR SO...AN INDICATION THAT SOME
RELATIVELY HEAVY SNOW MAY FALL FOR AT LEAST A SHORT TIME. 850 HPA
TEMPS COOLING TO AROUND -9C...AND RESULTING LAKE-850 HPA DELTA T
VALUES AROUND 16/17C WOULD POTENTIALLY SUPPORT 1-3/2-4 INCHES IF IT
WERE ABLE TO FOCUS ON A LOCALE FOR A FEW HOURS. GIVEN TRANSIENT
NATURE AND RELATIVELY SHORT DURATION EXPECTED FOR BAND TO REALLY
FOCUS ON NORTHEAST PORTER COUNTY...WOULD THINK THAT THE LOWER END OF
THIS RANGE IS MORE LIKELY THROUGH MIDNIGHT TONIGHT. AGAIN...SNOW
SHOULD END FOR PORTER COUNTY BY 06-09Z TONIGHT AS THE FOCUS DRIFTS
EAST OF THE AREA.
OTHERWISE...CONSIDERABLE AREA OF STRATUS/STRATOCU NOTED PER
AFTERNOON VISIBLE SATELLITE IMAGERY WITHIN LOW LEVEL COLD ADVECTION
BENEATH BROAD UPPER TROUGH WITH SERIES OF WEAK VORTS TRANSITING THE
REGION THROUGH TUESDAY. CLOUDS/FEW FLURRIES THIS AFTERNOON SHOULD
GRADUALLY TRANSITION TO PARTLY CLOUDY CONDITIONS FROM THE WEST LATE
TONIGHT/EARLY TUESDAY...WITH LARGE SCALE UPPER TROUGH AXIS FINALLY
MOVING EAST OF THE AREA TUESDAY NIGHT. BROAD...FLAT UPPER RIDGING
THEN BUILDS ACROSS THE GREAT LAKES AND SOUTHEAST WEDNESDAY/THURSDAY
WITH A PERIOD OF DRY AND SLOWLY MODERATING WEATHER.
NEXT WEATHER MAKER TO MONITOR IS AN UPPER TROUGH CURRENTLY
PROPAGATING ACROSS THE GULF OF ALASKA. MEDIUM RANGE GUIDANCE REMAINS
CONSISTENT IN DIGGING THIS SYSTEM SOUTH ALONG THE WEST COAST THROUGH
MID-WEEK...DEVELOPING INTO A CLOSED LOW ALONG THE CALIFORNIA COAST
BY LATE THURSDAY. THIS SYSTEM IS THEN PROGGED TO MOVE OUT ACROSS THE
PLAINS FRIDAY/FRIDAY NIGHT AND ACROSS OUR REGION SATURDAY. THERE
REMAINS SOME MODEL SPREAD WITH THE TRACK OF THE LOW ACROSS
MISSOURI/ILLINOIS BY SATURDAY...BUT THATS TO BE EXPECTED AT THIS
DISTANCE ESPECIALLY WITH LOWS EJECTING FROM THE SOUTHWESTERN STATES.
BOTH THE ECMWF AND GFS RUNS ARE A LITTLE FARTHER SOUTH THAN THOSE
FROM 24 HOURS AGO...THOUGH STILL APPEARS TO BE MAINLY A WARM/RAIN
EVENT FOR THE FORECAST AREA. CONTINUED TO FAVOR THE CONSISTENT ECMWF
SOLUTION FOR TIMING OF PRECIP/PRECIP TYPE FRIDAY NIGHT THROUGH
SATURDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* ANY BRIEF VFR/HIGHER END MVFR TO LOWER BACK TO CIGS BETWEEN 015
AND 020 THROUGH THIS EVENING.
* GUSTY SOUTHWEST WINDS 220-240 DEG ON TUESDAY...WITH GUSTS
POSSIBLY UP TO 20 KT.
RC
//DISCUSSION...UPDATED 20Z...
COLD AIR MASS MOVING OVER AREA THAT HAD CLEARED OUT OVER SOUTHERN
WISCONSIN RESULTED IN MVFR CIGS FILLING BACK IN...SO NOW EXPECT
MVFR CIGS TO LINGER THROUGH LATE TONIGHT BEFORE POSSIBLE
SCATTERING OUT TOWARD DAYBREAK. THERE MAY BE SOME GRADUAL LOWERING
OF CIG HEIGHT AFTER DARK...BUT NOT EXPECTING PREVAILING CIGS
BELOW 1500 FT AT TAF SITES. CANT RULE OUT SCT FLURRIES FROM TIME
TO TIME...BUT NO OPERATIONAL IMPACT.
FROM 18Z...
FRONTAL BOUNDARY CURRENTLY PUSHING THROUGH CHICAGO TERMINALS WITH
MVFR VSBY IN -SN AT MDW AS OF THIS WRITING. SNOW SHOWERS AND
SIMILAR VSBY RESTRICTION EXPECTED AS BOUNDARY PUSHES SOUTH THROUGH
GYY AND TERMINALS SOUTH OF CHICAGO AREA...WITH FLURRIES/SHSN
ENDING FROM NORTH BEHIND BOUNDARY AND WINDS TURNING NORTHWEST.
CLEARING HOLE IN SATELLITE OVER WISCONSIN CONTINUES TO PUSH
SOUTHWARD AS WELL...WITH A PERIOD OF MVFR CIGS BEFORE SCATTERING
OUT TO VFR AT LEAST BRIEFLY. CONCERN THAT CLEARING HOLE IS SHOWING
SIGNS OF FILLING BACK IN WITH MVFR CIGS AND COMBINING WITH ANOTHER
AREA OF MVFR CIGS DROPPING SOUTHWARD FROM NORTHERN WISCONSIN...SO
WILL ASSESS AND MAY NEED TO INCLUDE AN MVFR CIG IN 20Z UPDATE.
WINDS WILL DIMINISH AND BECOME LIGHT WEST LATE TONIGHT AND THEN
SOUTHWEST BEFORE DAYBREAK AS HIGH PRESSURE RIDGE SETTLES SOUTH OF
AREA. PRESSURE GRADIENT WILL TIGHTEN MID DAY TUESDAY AS A LOW
PRESSURE SYSTEM TRACKS NORTH OF GREAT LAKES...CAUSING SOUTHWEST
WINDS AT 220-240 DEG DIRECTION TO INCREASE. FORECAST SOUNDINGS
SUGGEST POTENTIAL FOR GUSTS IN THE UPPER TEENS TO AROUND 20 KT
THROUGH EARLY EVENING TOMORROW BEFORE MIXING DIMINISHES.
RC
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN MVFR CIGS THROUGH THIS EVENING...WITH CURRENT
BRIEF VFR AT MDW EXPECTED TO LOWER BACK TO MVFR SHORTLY.
* MEDIUM TO HIGH CONFIDENCE CIGS WILL REMAIN ABOVE 1500 FT.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS.
RC
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT THROUGH FRIDAY...VFR. WX NIL.
FRIDAY NIGHT THROUGH SATURDAY NIGHT...CHANCE OF RAIN. MVFR/IFR
CONDITIONS POSSIBLE.
SUNDAY...CHANCE OF RAIN...SNOW MIX. MVFR/IFR CONDITIONS POSSIBLE.
KREIN
&&
.MARINE...
300 AM CST
THE TWO SEPARATE LOW PRESSURE SYSTEM THAT PASSED THROUGH THE
REGION EARLIER SUNDAY EVENING HAVE MERGED INTO A CONSOLIDATED LOW
OVER THE EASTER GREAT LAKES...WHICH WILL CONTINUE TO DEEPEN
SLIGHTLY AS IT TRACKS INTO SOUTHERN ONTARIO. THIS WILL LEAD TO
WINDS BECOMING GENERALLY NORTHERLY OVER THE LAKE AT AROUND 25 TO
30 KT. A SECONDARY SURGE OF COLDER AIR MOVING DOWN THE LAKE MAY
BRING A BRIEF PERIOD WHERE THERE MAY BE A FEW GALE FORCE GUSTS
BEFORE SUNRISE. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD ACROSS
THE LAKE LATE TONIGHT AND TUESDAY AS A WEAK LOW PRESSURE SYSTEM
TRACKS ACROSS SOUTHERN CANADA. WINDS WILL GRADUALLY BECOME
SOUTHWESTERLY BY TUESDAY NIGHT AND WEDNESDAY. WITH HIGH PRESSURE
PERSISTING OVER THE OHIO VALLEY FROM TUESDAY THROUGH THURSDAY AND
A SERIES OF WEAK LOW PRESSURE SYSTEMS TRACK ACROSS THE NORTHERN
PLAINS AND UPPER GREAT LAKES...GENERALLY SOUTHWESTERLY WINDS WILL
REMAIN IN THE 25-30KT RANGE.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 4 AM TUESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
259 PM EST MON DEC 10 2012
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 10 2012
A WEAK WAVE MOVING THROUGH THE AREA TODAY COULD PROMPT A
FEW SNOWFLAKES ACROSS THE NORTHERN COUNTIES. TONIGHT HIGH PRESSURE
WILL BUILD INTO THE AREA AND BRING DRY WEATHER WHICH WILL LAST
THROUGH FRIDAY. BY FRIDAY NIGHT ANOTHER SYSTEM WILL APPROACH THE
AREA AND BRING CHANCES FOR RAIN THAT WILL LAST THROUGH THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1153 AM EST MON DEC 10 2012
LOWERED MAX TEMPS SIGNIFICANTLY IN THE NORTHWEST IN THE
UPDATE...AS WE HAVE LIKELY ALREADY REACHED OUR HIGHS THERE WITH
OVERCAST SKIES AND STRONG COLD ADVECTION ONGOING. THIS IS LIKELY
THE CASE IN THE SOUTHEAST AS WELL...BUT TEMPS THERE WERE ALREADY
NEAR MAXES. TEMPS LIKELY TO FALL GRADUALLY INTO THE AFTERNOON.
KEPT SLIGHT CHANCE POPS IN THE NORTH BUT EXPANDED FLURRY CHANCES
ACROSS THE ENTIRE FORECAST AREA...AS ALL RAP FORECAST SOUNDINGS
SHOW AT LEAST A BRIEF PERIOD OF SATURATION IN THE SNOW GROWTH
LAYER THIS AFTERNOON...AND REGIONAL MOSAICS ALREADY SHOW SOME
RETURNS UPSTREAM WITH FLURRIES REACHING THE GROUND AT AT LEAST A
FEW SITES IN SOUTHERN ILLINOIS AND WESTERN KENTUCKY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 355 AM EST MON DEC 10 2012
FORECAST FOCUS IS ON TEMPERATURES. MODELS IN GOOD AGREEMENT SO WILL
USE A CONSENSUS. TONIGHT AN UPPER WAVE WILL BE MAKING IT/S EXIT OF
THE AREA. WITH LAKE ENHANCEMENT STILL BRIEFLY AVAILABLE INCLUDED
SOME FLURRIES IN THE NORTHEAST AS IT LEAVES. AFTER THAT HIGH
PRESSURE BUILDS IN FOR THE REMAINDER OF THE SHORT TERM BRINGING WITH
IT CLEARING SKIES FROM ON TUESDAY AND THEN MOSTLY CLEAR THROUGH THE
SHORT TERM AND SLOWLY WARMING TEMPERATURES AFTER TUESDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 259 PM EST MON DEC 10 2012
OHIO VALLEY WILL BE ON THE BACK SIDE OF BROAD HIGH PRESSURE RIDGE
ACROSS MUCH OF THE EASTERN U S TO END THE WORK WEEK...KEEPING DRY
WEATHER ACROSS CENTRAL INDIANA. MODEL GUIDANCE IS IN BETTER
AGREEMENT THIS AFTERNOON WITH RESPECT TO THE APPROACH AND IMPACTS AS
A SHARP UPPER WAVE EJECTS OUT OF THE PACIFIC COAST TROUGH AND MOVES
INTO THE MIDWEST. ECMWF REMAINS THE MOST CONSISTENT WITH THE TRACK
OF THIS SYSTEM...WITH A GRADUALLY SLOWING OF THE IMPACTS AS A DEEPER
SYSTEM LIKELY TO NOT MOVE INTO THE REGION UNTIL SATURDAY AFTERNOON/
NIGHT.
ECMWF HAS THE SUPPORT OF THE OP GFS/UKMET/GFS ENSEMBLE MEAN WITH THE
GGEM THE ONLY SUBSTANTIAL OUTLIER. FEEL COMFORTABLE IN SLOWING
PRECIP ONSET TO LATE FRIDAY NIGHT ACROSS THE WEST...WITH MOST
LOCATIONS NOT SEEING ANY RAINFALL UNTIL SATURDAY AS THE SYSTEM MOVES
INTO THE MID MISSISSIPPI VALLEY. WILL CARRY POPS FOR SATURDAY
THROUGH SUNDAY WITH HIGHEST POPS FOCUSED ON SATURDAY AFTERNOON.
SHOULD MODEL TRENDS CONTINUE TO SLOW THE SYSTEM...MAY NEED TO RAISE
POPS FOR SATURDAY NIGHT AND SUNDAY MORNING FURTHER.
COLDER AIR WILL SPILL BACK INTO THE REGION SUNDAY AND CONTINUING
INTO EARLY NEXT WEEK AS THE LOW TRANSITIONS TO A COASTAL SYSTEM AND
MOVES SLOWLY INTO NEW ENGLAND THROUGH THE PERIOD. THIS
SOUTHWEST FLOW WILL BRING MILD TEMPS FOR MID DECEMBER WITH HIGHS IN
THE UPPER 40S/LOWER 50S FOR FRIDAY AND SATURDAY...WITH TEMPERATURES
RETURNING INTO THE LOWER AND MIDDLE 40S FOR SUNDAY AND MONDAY.
&&
.AVIATION /DISCUSSION FOR 101800Z TAF ISSUANCE/...
ISSUED AT 1217 PM EST MON DEC 10 2012
MVFR CEILINGS WILL CONTINUE THROUGH THE EVENING...WITH SKIES
CLEARING LATE TONIGHT.
MVFR STRATUS DECK WITH CEILINGS AT 1000-1500FT EXTENDING WEST OF
THE MISSISSIPPI RIVER EARLY THIS AFTERNOON. WITH AN UPPER WAVE
ALOFT STILL TO PASS ACROSS THE REGION THROUGH THE LATE AFTERNOON
AND EVENING...EXPECT LOWER CEILINGS WILL IMPACT ALL TERMINALS
INTO THE OVERNIGHT. MAY SEE A FEW FLURRIES AS WELL INTO THE
EVENING HOURS WITH KLAF STANDING THE GREATEST CHANCE AT SEEING
FLAKES. AT THIS POINT...DO NOT FORESEE ANY VISIBILITY RESTRICTIONS
FROM ANY FLURRIES/LIGHT SNOW SHOWERS. NORTHWEST WINDS WILL
CONTINUE AT 10-15KTS THROUGH SUNSET WITH SPORADIC HIGHER GUSTS.
SURFACE RIDGING WILL EXPAND INTO THE OHIO VALLEY OVERNIGHT WITH
LOW LEVEL FLOW BACKING TO A MORE WESTERLY DIRECTION AND LIGHTENING
BELOW 10KTS. MODEL SOUNDINGS AND RH PROGS INDICATE THAT LOWER
CEILINGS WILL DEPART BETWEEN 06-12Z TUESDAY FROM ALL OF THE
TERMINALS AS DRIER AIR ADVECTS INTO THE REGION. SKIES SHOULD BE
MAINLY CLEAR ON TUESDAY WITH FLOW BACKING TO A SOUTHWEST DIRECTION
AS THE HIGH PRESSURE RIDGE SETS UP OVER THE TENNESSEE AND LOWER
MISSISSIPPI VALLEYS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...NIELD
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
247 PM EST MON DEC 10 2012
.SHORT TERM...
DIFFICULT PD EARLY ON GIVEN SCOPE OF DVLPG LK RESPONSE. SFC TROUGH
ACRS NRN CONTS TO DROP SWD AND EMBOLDENING A BROADER RESPONSE
UNDERNEATH BALLOONING MID LVL MSTR PLUME. BRIEF PD OF FZDZ AND
PERHAPS SLEET AT ONSET BUT QUICKLY CHANGING OVR TO SHSN N-S TIMED
W/ARRIVAL OF LK MSTR ENTRAINMENT PLUME AND DEEPENING CAA WEDGE.
PRIMARY PROB THIS EVENING IS TEA KETTLE LK SETUP AND DENOTED QUITE
WELL IN RUC13 AND OTHER HIGHRES GUIDANCE. LK SP CONNECTION NOTED
THIS AFTN WITHIN FVRBLY VEERED LONG AXIS CYCLONIC FETCH AS SEEN IN
VIS IMAGERY AND SUSPECT LK CONVERGENCE ZONE WILL ABRUPTLY BLOSSOM
AFT SUNSET IN TANDEM W/MAXIMIZING LL THERMAL TROUGH OF WHICH MAY
LEAD TO A BRIEF PD OF SIG LK EFFECT SNOWFALL CNTRD THROUGH EXTREME
SW BERRIEN...NRN LAPORTE AND WRN ST JOE COUNTIES. TEMPTED TO
CONSIDER AN ADVISORY BUT GIVEN UPSTREAM LK DVLPMNTS HAVE YET TO
PLAY THEIR CARD...CONFIDENCE LACKING. WILL CONT TO MONITOR AND
PASS CONCERNS ONWARD.
OTRWS LG SCALE SFC RIDGE WILL BUILD ALG THE APPALACHIAN SPINE
THROUGH THE END OF THE PD AS WK SECONDARY SYS DIPS THROUGH SRN
ONTARIO. LL FLW BACKS ABRUPTLY LT TONIGHT TO WRLY W/DWINDLING LK
EFFECT LIFTING OUT BFR BACKING FURTHER TO SWRLY ON TUE. THIS WILL
YIELD SW-NE CLRG W/SOME INSOLATION HELPING TO BOOST TEMPS A BIT
WARMER THAN TDA.
&&
.LONG TERM...WEDNESDAY THROUGH MONDAY.
ENERGY CURRENTLY IN THE GULF OF ALASKA WILL DIG ALONG THE PACIFIC
COAST THROUGH THE UPCOMING WEEK...REACHING CALIFORNIA BY THURSDAY.
THIS WILL ALLOW FOR INCREASING HGTS WITH A SEMI ZONAL FLOW TO SET UP
THROUGH FRIDAY. TEMPS ARE EXPECTED TO MODERATE TO ABOVE NORMAL
LEVELS IN THE 40S.
LEE SIDE CYCLOGENESIS WILL TAKE PLACE STARTING LATE FRIDAY WITH THE
SYSTEM EJECTING TOWARDS THE GREAT LAKES. MODELS VARYING SOMEWHAT ON
TIMING AND OVERALL TRACK...BUT SEEM TO POINT TOWARDS THE FORECAST
AREA BEING ON THE WARM SIDE ONCE AGAIN...YIELDING RAIN CHANCES FOR
THE WEEKEND FOLLOWED BY A MIXTURE OF RAIN/SNOW IN ITS WAKE. PREV
GRIDS HAD DECENT HANDLE ON TRENDS. ONLY CHANGES MADE WAS TO BREAK UP
WITH SOMEWHAT MORE DETAIL TO TRY TO ADD SOME TIMING TO BETTER
CHANCES OF PRECIP. QUICK SHOT OF COLD AIR WILL ARRIVE BEHIND THE
SYSTEM...BUT NOTHING SUBSTANTIALLY COLDER WITH A RETURN TO NEAR OR
SLIGHTLY BELOW NORMAL READINGS.
ENERGIZED PATTERN WILL CONTINUE OUTSIDE THE LONG TERM PERIOD WITH
NEXT SYSTEM ALREADY TAKING SHAPE OVER TEXAS BY MONDAY NIGHT. ECMWF
OVER THE PAST SEVERAL RUNS HAS HINTED THAT THIS COULD BRING A DECENT
SHOT OF ACCUMULATING SNOWFALL TO THE REGION BOTH IN ADVANCE OF THE
SYSTEM AND WITH WHAT COULD BE A PERSISTENT DEFORMATION ZONE AS THE
LOW CUTS OFF SOMEWHERE IN THE EASTERN GREAT LAKES. PLENTY OF TIME TO
WATCH AT THIS POINT CONSIDERING STILL A WAYS TO GO.
&&
.AVIATION...
MOST DIFFICULT NR TERM W/ONGOING MID LVL SATURATION OVERTOP CONTD
MOIST BNDRY LYR. GENERAL TREND LAST 2 HOURS IS FOR GRADUAL MIST
DVLPMNT IN ASSOCN/W BNDRY LYR BASED ASCENT. HWVR XPC SOME SEEDING FM
ALOFT TO OCCUR TWD MID AFTN WHICH WILL PROMOTE A PD OF -DZ OR -RA
BFR CHANGING OVR THIS EVENING AS LL CAA WEDGE DEEPENS. THUS HAVE
ROLLED THE DICE AGAINST GUIDANCE W/CAT IFR CONDS GIVING WAY TO SVRL
HR PD OF LIFR CONDS AT KSBN COINCIDENT W/LK INDUCED SHSN. KFWA SHLD
HOLD IN IFR CAT THROUGH EARLY EVE BUT SOME IMPROVEMENT XPCD
OVERNIGHT INBEHIND SFC TROUGH PIVOTING SWD ACRS THE AREA THIS AFTN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR LMZ043-046.
&&
$$
SHORT TERM...T
LONG TERM...FISHER
AVIATION...T
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1217 PM EST MON DEC 10 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 10 2012
A WEAK WAVE MOVING THROUGH THE AREA TODAY COULD PROMPT A
FEW SNOWFLAKES ACROSS THE NORTHERN COUNTIES. TONIGHT HIGH PRESSURE
WILL BUILD INTO THE AREA AND BRING DRY WEATHER WHICH WILL LAST
THROUGH FRIDAY. BY FRIDAY NIGHT ANOTHER SYSTEM WILL APPROACH THE
AREA AND BRING CHANCES FOR RAIN THAT WILL LAST THROUGH THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1153 AM EST MON DEC 10 2012
LOWERED MAX TEMPS SIGNIFICANTLY IN THE NORTHWEST IN THE
UPDATE...AS WE HAVE LIKELY ALREADY REACHED OUR HIGHS THERE WITH
OVERCAST SKIES AND STRONG COLD ADVECTION ONGOING. THIS IS LIKELY
THE CASE IN THE SOUTHEAST AS WELL...BUT TEMPS THERE WERE ALREADY
NEAR MAXES. TEMPS LIKELY TO FALL GRADUALLY INTO THE AFTERNOON.
KEPT SLIGHT CHANCE POPS IN THE NORTH BUT EXPANDED FLURRY CHANCES
ACROSS THE ENTIRE FORECAST AREA...AS ALL RAP FORECAST SOUNDINGS
SHOW AT LEAST A BRIEF PERIOD OF SATURATION IN THE SNOW GROWTH
LAYER THIS AFTERNOON...AND REGIONAL MOSAICS ALREADY SHOW SOME
RETURNS UPSTREAM WITH FLURRIES REACHING THE GROUND AT AT LEAST A
FEW SITES IN SOUTHERN ILLINOIS AND WESTERN KENTUCKY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 355 AM EST MON DEC 10 2012
FORECAST FOCUS IS ON TEMPERATURES. MODELS IN GOOD AGREEMENT SO WILL
USE A CONSENSUS. TONIGHT AN UPPER WAVE WILL BE MAKING IT/S EXIT OF
THE AREA. WITH LAKE ENHANCEMENT STILL BRIEFLY AVAILABLE INCLUDED
SOME FLURRIES IN THE NORTHEAST AS IT LEAVES. AFTER THAT HIGH
PRESSURE BUILDS IN FOR THE REMAINDER OF THE SHORT TERM BRINGING WITH
IT CLEARING SKIES FROM ON TUESDAY AND THEN MOSTLY CLEAR THROUGH THE
SHORT TERM AND SLOWLY WARMING TEMPERATURES AFTER TUESDAY.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 305 AM EST MON DEC 10 2012
MAIN FOCUS TO THE EXTENDED WILL BE ON TIMING AND COVERAGE OF POPS
ACROSS CENTRAL INDIANA ASSOCIATED WITH A STRONG WEEKEND SYSTEM.
MODELS HAVE LARGE DIFFERENCES ON TIMING AND STRENGTH OF THE
AFOREMENTIONED STRONG UPPER AND SURFACE SYSTEMS...HOWEVER THE 00Z
ECMWF AND CANADIAN ARE THE CLOSEST WITH THE LATTER JUST A TOUCH
FASTER. BOTH WERE SHOWING NEGATIVELY TILTED UPPER TROUGHS AND SUB
1000 MILLIBAR SURFACE LOWS MOVING TO NEAR SOUTHERN LAKE MICHIGAN
LATE SATURDAY. REGARDLESS...ALL MODELS ARE SUGGESTING CHANCE POPS
ESPECIALLY WEST FRIDAY NIGHT WITH WIDESPREAD ACTIVITY ON SATURDAY
AND THEN LESSENING CHANCES SATURDAY NIGHT AND SUNDAY AS THE SYSTEM
LIFTS NORTHEAST INTO SOUTHEASTERN CANADA. REGIONAL INITIALIZATION
REFLECTS THIS WITH LIKELY POPS ON SATURDAY AND LESSER CHANCES FRIDAY
NIGHT AND SATURDAY NIGHT INTO SUNDAY. SO...WILL NOT MAKE ANY
CHANGES.
THE EXTENDED WILL START OFF WITH SURFACE HIGH PRESSURE ACROSS THE
SOUTHEASTERN STATES AND INCREASING SOUTHWEST FLOW ACROSS THE OHIO
VALLEY AHEAD OF THE AFOREMENTIONED WEATHER MAKER. THIS WILL ALLOW
FOR ABOVE NORMAL TEMPERATURES CLIMAXING ON SATURDAY IN THE UPPER 40S
NORTH AND LOWER 50S SOUTH. BEHIND THE FRONT...TEMPERATURES WILL BE
NEAR NORMAL. WILL ACCEPT REGIONAL INITIALIZATION TEMPERATURES
ESPECIALLY WITH THE MODEL DIFFERENCES IN PLAY.
&&
.AVIATION /DISCUSSION FOR 101800Z TAF ISSUANCE/...
ISSUED AT 1217 PM EST MON DEC 10 2012
MVFR CEILINGS WILL CONTINUE THROUGH THE EVENING...WITH SKIES
CLEARING LATE TONIGHT.
MVFR STRATUS DECK WITH CEILINGS AT 1000-1500FT EXTENDING WEST OF
THE MISSISSIPPI RIVER EARLY THIS AFTERNOON. WITH AN UPPER WAVE
ALOFT STILL TO PASS ACROSS THE REGION THROUGH THE LATE AFTERNOON
AND EVENING...EXPECT LOWER CEILINGS WILL IMPACT ALL TERMINALS
INTO THE OVERNIGHT. MAY SEE A FEW FLURRIES AS WELL INTO THE
EVENING HOURS WITH KLAF STANDING THE GREATEST CHANCE AT SEEING
FLAKES. AT THIS POINT...DO NOT FORESEE ANY VISIBILITY RESTRICTIONS
FROM ANY FLURRIES/LIGHT SNOW SHOWERS. NORTHWEST WINDS WILL
CONTINUE AT 10-15KTS THROUGH SUNSET WITH SPORADIC HIGHER GUSTS.
SURFACE RIDGING WILL EXPAND INTO THE OHIO VALLEY OVERNIGHT WITH
LOW LEVEL FLOW BACKING TO A MORE WESTERLY DIRECTION AND LIGHTENING
BELOW 10KTS. MODEL SOUNDINGS AND RH PROGS INDICATE THAT LOWER
CEILINGS WILL DEPART BETWEEN 06-12Z TUESDAY FROM ALL OF THE
TERMINALS AS DRIER AIR ADVECTS INTO THE REGION. SKIES SHOULD BE
MAINLY CLEAR ON TUESDAY WITH FLOW BACKING TO A SOUTHWEST DIRECTION
AS THE HIGH PRESSURE RIDGE SETS UP OVER THE TENNESSEE AND LOWER
MISSISSIPPI VALLEYS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...NIELD
SHORT TERM...CP
LONG TERM....MK
AVIATION...RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1154 AM EST MON DEC 10 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 10 2012
A WEAK WAVE MOVING THROUGH THE AREA TODAY COULD PROMPT A
FEW SNOWFLAKES ACROSS THE NORTHERN COUNTIES. TONIGHT HIGH PRESSURE
WILL BUILD INTO THE AREA AND BRING DRY WEATHER WHICH WILL LAST
THROUGH FRIDAY. BY FRIDAY NIGHT ANOTHER SYSTEM WILL APPROACH THE
AREA AND BRING CHANCES FOR RAIN THAT WILL LAST THROUGH THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1153 AM EST MON DEC 10 2012
LOWERED MAX TEMPS SIGNIFICANTLY IN THE NORTHWEST IN THE
UPDATE...AS WE HAVE LIKELY ALREADY REACHED OUR HIGHS THERE WITH
OVERCAST SKIES AND STRONG COLD ADVECTION ONGOING. THIS IS LIKELY
THE CASE IN THE SOUTHEAST AS WELL...BUT TEMPS THERE WERE ALREADY
NEAR MAXES. TEMPS LIKELY TO FALL GRADUALLY INTO THE AFTERNOON.
KEPT SLIGHT CHANCE POPS IN THE NORTH BUT EXPANDED FLURRY CHANCES
ACROSS THE ENTIRE FORECAST AREA...AS ALL RAP FORECAST SOUNDINGS
SHOW AT LEAST A BRIEF PERIOD OF SATURATION IN THE SNOW GROWTH
LAYER THIS AFTERNOON...AND REGIONAL MOSAICS ALREADY SHOW SOME
RETURNS UPSTREAM WITH FLURRIES REACHING THE GROUND AT AT LEAST A
FEW SITES IN SOUTHERN ILLINOIS AND WESTERN KENTUCKY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 355 AM EST MON DEC 10 2012
FORECAST FOCUS IS ON TEMPERATURES. MODELS IN GOOD AGREEMENT SO WILL
USE A CONSENSUS. TONIGHT AN UPPER WAVE WILL BE MAKING IT/S EXIT OF
THE AREA. WITH LAKE ENHANCEMENT STILL BRIEFLY AVAILABLE INCLUDED
SOME FLURRIES IN THE NORTHEAST AS IT LEAVES. AFTER THAT HIGH
PRESSURE BUILDS IN FOR THE REMAINDER OF THE SHORT TERM BRINGING WITH
IT CLEARING SKIES FROM ON TUESDAY AND THEN MOSTLY CLEAR THROUGH THE
SHORT TERM AND SLOWLY WARMING TEMPERATURES AFTER TUESDAY.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 305 AM EST MON DEC 10 2012
MAIN FOCUS TO THE EXTENDED WILL BE ON TIMING AND COVERAGE OF POPS
ACROSS CENTRAL INDIANA ASSOCIATED WITH A STRONG WEEKEND SYSTEM.
MODELS HAVE LARGE DIFFERENCES ON TIMING AND STRENGTH OF THE
AFOREMENTIONED STRONG UPPER AND SURFACE SYSTEMS...HOWEVER THE 00Z
ECMWF AND CANADIAN ARE THE CLOSEST WITH THE LATTER JUST A TOUCH
FASTER. BOTH WERE SHOWING NEGATIVELY TILTED UPPER TROUGHS AND SUB
1000 MILLIBAR SURFACE LOWS MOVING TO NEAR SOUTHERN LAKE MICHIGAN
LATE SATURDAY. REGARDLESS...ALL MODELS ARE SUGGESTING CHANCE POPS
ESPECIALLY WEST FRIDAY NIGHT WITH WIDESPREAD ACTIVITY ON SATURDAY
AND THEN LESSENING CHANCES SATURDAY NIGHT AND SUNDAY AS THE SYSTEM
LIFTS NORTHEAST INTO SOUTHEASTERN CANADA. REGIONAL INITIALIZATION
REFLECTS THIS WITH LIKELY POPS ON SATURDAY AND LESSER CHANCES FRIDAY
NIGHT AND SATURDAY NIGHT INTO SUNDAY. SO...WILL NOT MAKE ANY
CHANGES.
THE EXTENDED WILL START OFF WITH SURFACE HIGH PRESSURE ACROSS THE
SOUTHEASTERN STATES AND INCREASING SOUTHWEST FLOW ACROSS THE OHIO
VALLEY AHEAD OF THE AFOREMENTIONED WEATHER MAKER. THIS WILL ALLOW
FOR ABOVE NORMAL TEMPERATURES CLIMAXING ON SATURDAY IN THE UPPER 40S
NORTH AND LOWER 50S SOUTH. BEHIND THE FRONT...TEMPERATURES WILL BE
NEAR NORMAL. WILL ACCEPT REGIONAL INITIALIZATION TEMPERATURES
ESPECIALLY WITH THE MODEL DIFFERENCES IN PLAY.
&&
.AVIATION /DISCUSSION FOR THE 10/15Z TAF UPDATE/...
ISSUED AT 932 AM EST MON DEC 10 2012
ADDED TEMPO GROUPS TO IND/BMG FOR BRIEF DROPS INTO HIGH END IFR
TERRITORY ON CEILINGS. PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 440 AM EST MON DEC 10 2012
MVFR CEILINGS EXPECTED THROUGH MUCH OF THE TAF PERIOD IMPROVING TO
VFR AFTER 07Z TUESDAY. COULD ALSO SEE A FEW AFTERNOON FLURRIES AS A
WEAK UPPER WAVE MOVES THROUGH. OTHERWISE...NORTHWEST WINDS AT 10
KNOTS OR SO WILL DROP BELOW 10 KNOTS AFTER 00Z. WINDS AND MUCH DRIER
AIR WILL PREVENT ANY VISIBILITY RESTRICTIONS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...NIELD
SHORT TERM...CP
LONG TERM....MK
AVIATION...MK/NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
932 AM EST MON DEC 10 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 10 2012
A WEAK WAVE MOVING THROUGH THE AREA TODAY COULD PROMPT A
FEW SNOWFLAKES ACROSS THE NORTHERN COUNTIES. TONIGHT HIGH PRESSURE
WILL BUILD INTO THE AREA AND BRING DRY WEATHER WHICH WILL LAST
THROUGH FRIDAY. BY FRIDAY NIGHT ANOTHER SYSTEM WILL APPROACH THE
AREA AND BRING CHANCES FOR RAIN THAT WILL LAST THROUGH THE WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 355 AM EST MON DEC 10 2012
AT 8Z RADAR MOSAIC SHOWED ALL RAIN HAD MOVED SOUTHEAST OF THE AREA.
SURFACE ANALYSIS SHOWED SURFACE LOW CENTERED OVER LAKE ERIE WITH A
COLD FRONT STRETCHING SOUTHWEST THROUGH WESTERN OHIO AND CENTRAL
KENTUCKY AND TENNESSEE TO NORTHERN MISSISSIPPI. MODELS SHOW THE LOW
CONTINUING TO MOVE NORTHEAST THROUGH THE DAY WITH THE FRONT BEING
DRAGGED EAST AS WELL. DRY AIR WAS WORKING ITS WAY INTO CENTRAL
INDIANA. A COUPLE MODELS ARE SHOWING SOME OF THE RAIN MAKING ITS WAY
BACK NORTH INTO THE SOUTHERN COUNTIES BUT MAJORITY ARE
NOT...INCLUDING THE RAP WHICH SEEMS TO HAVE A GOOD HANDLE ON CURRENT
PRECIP AREA...SO IT LOOKS UNLIKELY THAT IT WOULD GET THIS FAR NORTH.
WILL JUST INCLUDE A SLIGHT CHANCE FOR RAIN IN THE FAR SOUTHEAST
THROUGH THE MORNING.
MODELS SHOW A WEAK UPPER WAVE MOVING THROUGH THE NORTH IN
THE AFTERNOON/EVENING. NOT A LOT OF MOISTURE TO WORK WITH BUT COULD
PROMPT SOME FLURRIES ACROSS THE NORTHERN HALF OR SO OF THE AREA.
WITH 850 MB WINDS OUT OF THE NORTH TO NORTHEAST BRIEFLY COULD
PROVIDE SOME LAKE ENHANCEMENT TO THESE FLURRIES AND SO INCLUDED A
SLIGHT CHANCE OF MEASURABLE SNOW IN THE FAR NORTH TO COVER THIS
POSSIBILITY. STILL LITTLE TO NO ACCUMULATION EXPECTED.
ALTHOUGH DRY AIR ADVECTS IN ALOFT TIME HEIGHTS SHOW LOW LEVELS
REMAINING SATURATED. COMBINING THAT WITH CURRENT SATELLITE TRENDS
AND LOW CLOUDS EXTENDING BACK INTO WESTERN IOWA AND MINNESOTA THINK
SKIES WILL REMAIN CLOUDY THROUGH TODAY AND TONIGHT. FOR TEMPERATURES
WENT A LITTLE COLDER THAN CONSENSUS WITH COLD ADVECTION AND CLOUDY
SKIES.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 355 AM EST MON DEC 10 2012
FORECAST FOCUS IS ON TEMPERATURES. MODELS IN GOOD AGREEMENT SO WILL
USE A CONSENSUS. TONIGHT AN UPPER WAVE WILL BE MAKING IT/S EXIT OF
THE AREA. WITH LAKE ENHANCEMENT STILL BRIEFLY AVAILABLE INCLUDED
SOME FLURRIES IN THE NORTHEAST AS IT LEAVES. AFTER THAT HIGH
PRESSURE BUILDS IN FOR THE REMAINDER OF THE SHORT TERM BRINGING WITH
IT CLEARING SKIES FROM ON TUESDAY AND THEN MOSTLY CLEAR THROUGH THE
SHORT TERM AND SLOWLY WARMING TEMPERATURES AFTER TUESDAY.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 305 AM EST MON DEC 10 2012
MAIN FOCUS TO THE EXTENDED WILL BE ON TIMING AND COVERAGE OF POPS
ACROSS CENTRAL INDIANA ASSOCIATED WITH A STRONG WEEKEND SYSTEM.
MODELS HAVE LARGE DIFFERENCES ON TIMING AND STRENGTH OF THE
AFOREMENTIONED STRONG UPPER AND SURFACE SYSTEMS...HOWEVER THE 00Z
ECMWF AND CANADIAN ARE THE CLOSEST WITH THE LATTER JUST A TOUCH
FASTER. BOTH WERE SHOWING NEGATIVELY TILTED UPPER TROUGHS AND SUB
1000 MILLIBAR SURFACE LOWS MOVING TO NEAR SOUTHERN LAKE MICHIGAN
LATE SATURDAY. REGARDLESS...ALL MODELS ARE SUGGESTING CHANCE POPS
ESPECIALLY WEST FRIDAY NIGHT WITH WIDESPREAD ACTIVITY ON SATURDAY
AND THEN LESSENING CHANCES SATURDAY NIGHT AND SUNDAY AS THE SYSTEM
LIFTS NORTHEAST INTO SOUTHEASTERN CANADA. REGIONAL INITIALIZATION
REFLECTS THIS WITH LIKELY POPS ON SATURDAY AND LESSER CHANCES FRIDAY
NIGHT AND SATURDAY NIGHT INTO SUNDAY. SO...WILL NOT MAKE ANY
CHANGES.
THE EXTENDED WILL START OFF WITH SURFACE HIGH PRESSURE ACROSS THE
SOUTHEASTERN STATES AND INCREASING SOUTHWEST FLOW ACROSS THE OHIO
VALLEY AHEAD OF THE AFOREMENTIONED WEATHER MAKER. THIS WILL ALLOW
FOR ABOVE NORMAL TEMPERATURES CLIMAXING ON SATURDAY IN THE UPPER 40S
NORTH AND LOWER 50S SOUTH. BEHIND THE FRONT...TEMPERATURES WILL BE
NEAR NORMAL. WILL ACCEPT REGIONAL INITIALIZATION TEMPERATURES
ESPECIALLY WITH THE MODEL DIFFERENCES IN PLAY.
&&
.AVIATION /DISCUSSION FOR THE 10/15Z TAF UPDATE/...
ISSUED AT 932 AM EST MON DEC 10 2012
ADDED TEMPO GROUPS TO IND/BMG FOR BRIEF DROPS INTO HIGH END IFR
TERRITORY ON CEILINGS. PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 440 AM EST MON DEC 10 2012
MVFR CEILINGS EXPECTED THROUGH MUCH OF THE TAF PERIOD IMPROVING TO
VFR AFTER 07Z TUESDAY. COULD ALSO SEE A FEW AFTERNOON FLURRIES AS A
WEAK UPPER WAVE MOVES THROUGH. OTHERWISE...NORTHWEST WINDS AT 10
KNOTS OR SO WILL DROP BELOW 10 KNOTS AFTER 00Z. WINDS AND MUCH DRIER
AIR WILL PREVENT ANY VISIBILITY RESTRICTIONS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....MK
AVIATION...MK/NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
440 AM EST MON DEC 10 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 10 2012
A WEAK WAVE MOVING THROUGH THE AREA TODAY COULD PROMPT A
FEW SNOWFLAKES ACROSS THE NORTHERN COUNTIES. TONIGHT HIGH PRESSURE
WILL BUILD INTO THE AREA AND BRING DRY WEATHER WHICH WILL LAST
THROUGH FRIDAY. BY FRIDAY NIGHT ANOTHER SYSTEM WILL APPROACH THE
AREA AND BRING CHANCES FOR RAIN THAT WILL LAST THROUGH THE WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 355 AM EST MON DEC 10 2012
AT 8Z RADAR MOSAIC SHOWED ALL RAIN HAD MOVED SOUTHEAST OF THE AREA.
SURFACE ANALYSIS SHOWED SURFACE LOW CENTERED OVER LAKE ERIE WITH A
COLD FRONT STRETCHING SOUTHWEST THROUGH WESTERN OHIO AND CENTRAL
KENTUCKY AND TENNESSEE TO NORTHERN MISSISSIPPI. MODELS SHOW THE LOW
CONTINUING TO MOVE NORTHEAST THROUGH THE DAY WITH THE FRONT BEING
DRAGGED EAST AS WELL. DRY AIR WAS WORKING ITS WAY INTO CENTRAL
INDIANA. A COUPLE MODELS ARE SHOWING SOME OF THE RAIN MAKING ITS WAY
BACK NORTH INTO THE SOUTHERN COUNTIES BUT MAJORITY ARE
NOT...INCLUDING THE RAP WHICH SEEMS TO HAVE A GOOD HANDLE ON CURRENT
PRECIP AREA...SO IT LOOKS UNLIKELY THAT IT WOULD GET THIS FAR NORTH.
WILL JUST INCLUDE A SLIGHT CHANCE FOR RAIN IN THE FAR SOUTHEAST
THROUGH THE MORNING.
MODELS SHOW A WEAK UPPER WAVE MOVING THROUGH THE NORTH IN
THE AFTERNOON/EVENING. NOT A LOT OF MOISTURE TO WORK WITH BUT COULD
PROMPT SOME FLURRIES ACROSS THE NORTHERN HALF OR SO OF THE AREA.
WITH 850 MB WINDS OUT OF THE NORTH TO NORTHEAST BRIEFLY COULD
PROVIDE SOME LAKE ENHANCEMENT TO THESE FLURRIES AND SO INCLUDED A
SLIGHT CHANCE OF MEASURABLE SNOW IN THE FAR NORTH TO COVER THIS
POSSIBILITY. STILL LITTLE TO NO ACCUMULATION EXPECTED.
ALTHOUGH DRY AIR ADVECTS IN ALOFT TIME HEIGHTS SHOW LOW LEVELS
REMAINING SATURATED. COMBINING THAT WITH CURRENT SATELLITE TRENDS
AND LOW CLOUDS EXTENDING BACK INTO WESTERN IOWA AND MINNESOTA THINK
SKIES WILL REMAIN CLOUDY THROUGH TODAY AND TONIGHT. FOR TEMPERATURES
WENT A LITTLE COLDER THAN CONSENSUS WITH COLD ADVECTION AND CLOUDY
SKIES.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 355 AM EST MON DEC 10 2012
FORECAST FOCUS IS ON TEMPERATURES. MODELS IN GOOD AGREEMENT SO WILL
USE A CONSENSUS. TONIGHT AN UPPER WAVE WILL BE MAKING IT/S EXIT OF
THE AREA. WITH LAKE ENHANCEMENT STILL BRIEFLY AVAILABLE INCLUDED
SOME FLURRIES IN THE NORTHEAST AS IT LEAVES. AFTER THAT HIGH
PRESSURE BUILDS IN FOR THE REMAINDER OF THE SHORT TERM BRINGING WITH
IT CLEARING SKIES FROM ON TUESDAY AND THEN MOSTLY CLEAR THROUGH THE
SHORT TERM AND SLOWLY WARMING TEMPERATURES AFTER TUESDAY.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 305 AM EST MON DEC 10 2012
MAIN FOCUS TO THE EXTENDED WILL BE ON TIMING AND COVERAGE OF POPS
ACROSS CENTRAL INDIANA ASSOCIATED WITH A STRONG WEEKEND SYSTEM.
MODELS HAVE LARGE DIFFERENCES ON TIMING AND STRENGTH OF THE
AFOREMENTIONED STRONG UPPER AND SURFACE SYSTEMS...HOWEVER THE 00Z
ECMWF AND CANADIAN ARE THE CLOSEST WITH THE LATTER JUST A TOUCH
FASTER. BOTH WERE SHOWING NEGATIVELY TILTED UPPER TROUGHS AND SUB
1000 MILLIBAR SURFACE LOWS MOVING TO NEAR SOUTHERN LAKE MICHIGAN
LATE SATURDAY. REGARDLESS...ALL MODELS ARE SUGGESTING CHANCE POPS
ESPECIALLY WEST FRIDAY NIGHT WITH WIDESPREAD ACTIVITY ON SATURDAY
AND THEN LESSENING CHANCES SATURDAY NIGHT AND SUNDAY AS THE SYSTEM
LIFTS NORTHEAST INTO SOUTHEASTERN CANADA. REGIONAL INITIALIZATION
REFLECTS THIS WITH LIKELY POPS ON SATURDAY AND LESSER CHANCES FRIDAY
NIGHT AND SATURDAY NIGHT INTO SUNDAY. SO...WILL NOT MAKE ANY
CHANGES.
THE EXTENDED WILL START OFF WITH SURFACE HIGH PRESSURE ACROSS THE
SOUTHEASTERN STATES AND INCREASING SOUTHWEST FLOW ACROSS THE OHIO
VALLEY AHEAD OF THE AFOREMENTIONED WEATHER MAKER. THIS WILL ALLOW
FOR ABOVE NORMAL TEMPERATURES CLIMAXING ON SATURDAY IN THE UPPER 40S
NORTH AND LOWER 50S SOUTH. BEHIND THE FRONT...TEMPERATURES WILL BE
NEAR NORMAL. WILL ACCEPT REGIONAL INITIALIZATION TEMPERATURES
ESPECIALLY WITH THE MODEL DIFFERENCES IN PLAY.
&&
.AVIATION /DISCUSSION FOR THE 101200Z TAF ISSUANCE/...
ISSUED AT 440 AM EST MON DEC 10 2012
MVFR CEILINGS EXPECTED THROUGH MUCH OF THE TAF PERIOD IMPROVING TO
VFR AFTER 07Z TUESDAY. COULD ALSO SEE A FEW AFTERNOON FLURRIES AS A
WEAK UPPER WAVE MOVES THROUGH. OTHERWISE...NORTHWEST WINDS AT 10
KNOTS OR SO WILL DROP BELOW 10 KNOTS AFTER 00Z. WINDS AND MUCH DRIER
AIR WILL PREVENT ANY VISIBILITY RESTRICTIONS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....MK
AVIATION...MK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
356 AM EST MON DEC 10 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 355 AM EST MON DEC 10 2012
A WEAK WAVE MOVING THROUGH THE AREA TODAY COULD PROMPT A
FEW SNOWFLAKES ACROSS THE NORTHERN COUNTIES. TONIGHT HIGH PRESSURE
WILL BUILD INTO THE AREA AND BRING DRY WEATHER WHICH WILL LAST
THROUGH FRIDAY. BY FRIDAY NIGHT ANOTHER SYSTEM WILL APPROACH THE
AREA AND BRING CHANCES FOR RAIN THAT WILL LAST THROUGH THE WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 355 AM EST MON DEC 10 2012
AT 8Z RADAR MOSAIC SHOWED ALL RAIN HAD MOVED SOUTHEAST OF THE AREA.
SURFACE ANALYSIS SHOWED SURFACE LOW CENTERED OVER LAKE ERIE WITH A
COLD FRONT STRETCHING SOUTHWEST THROUGH WESTERN OHIO AND CENTRAL
KENTUCKY AND TENNESSEE TO NORTHERN MISSISSIPPI. MODELS SHOW THE LOW
CONTINUING TO MOVE NORTHEAST THROUGH THE DAY WITH THE FRONT BEING
DRAGGED EAST AS WELL. DRY AIR WAS WORKING ITS WAY INTO CENTRAL
INDIANA. A COUPLE MODELS ARE SHOWING SOME OF THE RAIN MAKING ITS WAY
BACK NORTH INTO THE SOUTHERN COUNTIES BUT MAJORITY ARE
NOT...INCLUDING THE RAP WHICH SEEMS TO HAVE A GOOD HANDLE ON CURRENT
PRECIP AREA...SO IT LOOKS UNLIKELY THAT IT WOULD GET THIS FAR NORTH.
WILL JUST INCLUDE A SLIGHT CHANCE FOR RAIN IN THE FAR SOUTHEAST
THROUGH THE MORNING.
MODELS SHOW A WEAK UPPER WAVE MOVING THROUGH THE NORTH IN
THE AFTERNOON/EVENING. NOT A LOT OF MOISTURE TO WORK WITH BUT COULD
PROMPT SOME FLURRIES ACROSS THE NORTHERN HALF OR SO OF THE AREA.
WITH 850 MB WINDS OUT OF THE NORTH TO NORTHEAST BRIEFLY COULD
PROVIDE SOME LAKE ENHANCEMENT TO THESE FLURRIES AND SO INCLUDED A
SLIGHT CHANCE OF MEASURABLE SNOW IN THE FAR NORTH TO COVER THIS
POSSIBILITY. STILL LITTLE TO NO ACCUMULATION EXPECTED.
ALTHOUGH DRY AIR ADVECTS IN ALOFT TIME HEIGHTS SHOW LOW LEVELS
REMAINING SATURATED. COMBINING THAT WITH CURRENT SATELLITE TRENDS
AND LOW CLOUDS EXTENDING BACK INTO WESTERN IOWA AND MINNESOTA THINK
SKIES WILL REMAIN CLOUDY THROUGH TODAY AND TONIGHT. FOR TEMPERATURES
WENT A LITTLE COLDER THAN CONSENSUS WITH COLD ADVECTION AND CLOUDY
SKIES.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 355 AM EST MON DEC 10 2012
FORECAST FOCUS IS ON TEMPERATURES. MODELS IN GOOD AGREEMENT SO WILL
USE A CONSENSUS. TONIGHT AN UPPER WAVE WILL BE MAKING IT/S EXIT OF
THE AREA. WITH LAKE ENHANCEMENT STILL BRIEFLY AVAILABLE INCLUDED
SOME FLURRIES IN THE NORTHEAST AS IT LEAVES. AFTER THAT HIGH
PRESSURE BUILDS IN FOR THE REMAINDER OF THE SHORT TERM BRINGING WITH
IT CLEARING SKIES FROM ON TUESDAY AND THEN MOSTLY CLEAR THROUGH THE
SHORT TERM AND SLOWLY WARMING TEMPERATURES AFTER TUESDAY.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 305 AM EST MON DEC 10 2012
MAIN FOCUS TO THE EXTENDED WILL BE ON TIMING AND COVERAGE OF POPS
ACROSS CENTRAL INDIANA ASSOCIATED WITH A STRONG WEEKEND SYSTEM.
MODELS HAVE LARGE DIFFERENCES ON TIMING AND STRENGTH OF THE
AFOREMENTIONED STRONG UPPER AND SURFACE SYSTEMS...HOWEVER THE 00Z
ECMWF AND CANADIAN ARE THE CLOSEST WITH THE LATTER JUST A TOUCH
FASTER. BOTH WERE SHOWING NEGATIVELY TILTED UPPER TROUGHS AND SUB
1000 MILLIBAR SURFACE LOWS MOVING TO NEAR SOUTHERN LAKE MICHIGAN
LATE SATURDAY. REGARDLESS...ALL MODELS ARE SUGGESTING CHANCE POPS
ESPECIALLY WEST FRIDAY NIGHT WITH WIDESPREAD ACTIVITY ON SATURDAY
AND THEN LESSENING CHANCES SATURDAY NIGHT AND SUNDAY AS THE SYSTEM
LIFTS NORTHEAST INTO SOUTHEASTERN CANADA. REGIONAL INITIALIZATION
REFLECTS THIS WITH LIKELY POPS ON SATURDAY AND LESSER CHANCES FRIDAY
NIGHT AND SATURDAY NIGHT INTO SUNDAY. SO...WILL NOT MAKE ANY
CHANGES.
THE EXTENDED WILL START OFF WITH SURFACE HIGH PRESSURE ACROSS THE
SOUTHEASTERN STATES AND INCREASING SOUTHWEST FLOW ACROSS THE OHIO
VALLEY AHEAD OF THE AFOREMENTIONED WEATHER MAKER. THIS WILL ALLOW
FOR ABOVE NORMAL TEMPERATURES CLIMAXING ON SATURDAY IN THE UPPER 40S
NORTH AND LOWER 50S SOUTH. BEHIND THE FRONT...TEMPERATURES WILL BE
NEAR NORMAL. WILL ACCEPT REGIONAL INITIALIZATION TEMPERATURES
ESPECIALLY WITH THE MODEL DIFFERENCES IN PLAY.
&&
.AVIATION /DISCUSSION FOR THE 100900Z IND TAF UPDATE/...
ISSUED AT 320 AM EST MON DEC 10 2012
FLIGHT CATEGORY HAS IMPROVED TO MVFR AT IND WITH CEILINGS UP TO 12K
FEET. IT SHOULD REMAIN MOSTLY MVFR THROUGH THE REST OF THE TAF
PERIOD.
PREVIOUS DISCUSSION FOLLOWS...
WIDESPREAD IFR CEILINGS 006-008 AGL ACROSS THE AREA...HOWEVER
DRIER AIR ADVECTING IN BEHIND THE COLD FRONT HAS ALLOWED CEILINGS TO
IMPROVE INTO THE MVFR CATEGORY OVER ILLINOIS. THESE HIGHER CEILINGS
SHOULD CONTINUE TO ADVECT INTO THE AREA OVERNIGHT...WITH CEILINGS
IMPROVING INTO THE MVFR CATEGORY PRIOR TO SUNRISE ON MONDAY. THE
MVFR CEILINGS EXPECTED TO LINGER THROUGH MIDDAY MONDAY AT LEAST.
PRESSURE RISE MAX CURRENTLY MOVING INTO WESTERN INDIANA...SO SOME
SURFACE WIND GUST TO AROUND 18 KTS FROM 290-310 DEGREES POSSIBLE FOR
THE REST OF THE NIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....MK
AVIATION...JAS/MK
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1028 AM MST MON DEC 10 2012
.UPDATE...
ISSUED AT 922 AM MST MON DEC 10 2012
EXPIRED WIND CHILL ADVISORY.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 248 AM MST MON DEC 10 2012
04Z WATER VAPOR IMAGERY INDICATED TROUGH AXIS CENTERED OVER THE
CWA WITH BROAD RIDGING ACROSS THE WEST COAST. RAP DYNAMIC TROPOPAUSE
ANALYSIS INDICATED SHORT WAVE TROUGH MOVING OVER MONTANA...BUT DID
NOT APPEAR TO BE MUCH OF A RESPONSE ON WV IMAGERY. AT THE
SFC...RIDGE AXIS WAS LOCATED ALONG A KITR TO KANW LINE WITH
TEMPERATURES ALREADY IN THE SINGLE DIGITS ACROSS THE AREA.
MAIN SHORT TERM CONCERNS WILL BE WIND CHILLS THIS MORNING FOLLOWED
BY HOW QUICKLY TEMPERATURES RECOVER THROUGH THE MIDDLE OF THE WEEK.
EARLY MORNING HOURS...TEMPS HAVE FALLEN TO SEVERAL DEGREES BELOW
ZERO ACROSS NORTHEAST CWA WITH WINDS AROUND 10 MPH CREATING WIND
CHILLS IN THE -15 TO -20 RANGE. ALTHOUGH SOME SLIGHT WARMING HAS
BEEN NOTED ACROSS EASTERN COLORADO IN RESPONSE TO CONTINUED WESTERLY
FLOW/WAA...WILL LIKELY BE SEVERAL HOURS BEFORE THAT HAS A MEANINGFUL
IMPACT ACROSS NORTHEAST CWA. ALTHOUGH WINDS ARE NOT STRONG...THINK
CURRENT TEMPS WARRANT A WIND CHILL ADVISORY FOR THE MORNING HOURS.
WHILE CONDITIONS HAVE ALREADY OCCURRED ACROSS EASTERN
COLORADO...AFOREMENTIONED WARMING TREND IN OBS LEADS ME TO THINK
THREAT NOT GREAT IN THIS AREA.
TODAY...WEAK SHORT WAVE TROUGH WILL APPROACH FROM THE NORTH THIS
MORNING...BUT WITH VERY STABLE CONDITIONS EXPECTED FROM NEAR TERM
MODELS AND 00Z OBSERVATIONS AM DOUBTFUL THAT THIS INITIAL TROUGH WILL
DO MORE THAN CREATE A FEW HIGH CLOUDS THROUGH THE MORNING HOURS.
MAIN ISSUE TODAY WILL BE THE GUSTY WINDS THIS AFTERNOON AND HOW
QUICKLY TDS RECOVER FROM INITIAL VERY LOW VALUES AS POTENTIAL EXISTS
FOR LOW END CRITICAL FIRE WEATHER CONDITIONS TODAY. WINDS WILL PICK
UP INTO THE 15 TO 25 MPH RANGE DURING THE AFTERNOON...BUT THINK TDS
WILL ACTUALLY RISE SEVERAL DEGREES WITH VERTICAL MIXING. CURRENT
THOUGHTS KEEP THE HIGHEST WINDS AND DRIEST HUMIDITIES NOT VERY
COLOCATED AND WITH POTENTIAL FOR RISING AFTERNOON TDS...DO NOT PLAN
ON ISSUING A RFW AT THE MOMENT.
TONIGHT-TOMORROW...1.5 PVU FIELDS INDICATE SEVERAL SMALL SCALE SHORT
WAVE TROUGHS MOVING THROUGH THE FLOW TONIGHT...WITH STRONGEST (AT
LEAST FROM A PV PERSPECTIVE) COMING THROUGH THE CWA ON TUESDAY. GFS
AND NAM DIFFER ON STABILITY PROFILES OVERNIGHT WITH GFS INDICATING A
POCKET OF NEAR NEUTRAL CONDITIONS ACROSS WESTERN CWA BETWEEN 0 AND
06Z. WHILE NAM IS SLIGHTLY MORE STABLE...POINT SOUNDINGS DO INDICATE
SNOW GROWTH ZONE NOT TO FAR ABOVE THE SURFACE WITH A PERIOD OF ASCENT
MAXIMIZED IN THIS AREA. DO NOT THINK LIFT WILL BE ENOUGH FOR
MEANINGFUL PRECIP...BUT A FLURRY OR TWO DOES NOT LOOK UNREASONABLE.
DESPITE AN APPARENTLY STRONGER TROUGH ON TUESDAY...NEAR GROUND SNOW
GROWTH ZONE DISAPPEARS AND OVERALL PROFILES ARE MUCH MORE
STABLE...SO DO NOT EXPECT FLURRIES TO CARRY ON THROUGH THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 AM MST MON DEC 10 2012
TUESDAY NIGHT-WEDNESDAY NIGHT...QUIET WEATHER EXPECTED FOR THE
PERIOD AS SHORT WAVE RIDGING WILL BUILD OVER THE AREA AS FLOW
BECOMES MORE AMPLIFIED IN RESPONSE TO TROUGH DEVELOPING OVER WEST
COAST. THINK A RAPID WARM UP IS POSSIBLE...WITH TEMPS APPROACHING
UPPER 50S TO LOW 60S BY WEDNESDAY. AM A LITTLE CONCERNED THAT
CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP ON WEDNESDAY AS
DEWPOINTS WILL REMAIN FAIRLY LOW AND NOT UNHEARD OF FOR DEVELOPING
LEE TROUGH TO BRING GUSTY WINDS. RIGHT NOW...THINGS LOOK TOO
MARGINAL FOR POTENTIAL WATCH...BUT WILL KEEP AN EYE ON AS PERIOD
APPROACHES.
THURSDAY-MONDAY...
SW FLOW WILL BE IN PLACE THURSDAY AS DEEP TROUGH DEVELOPS OVER THE
WESTERN US...WHICH SHOULD KEEP CONDITIONS MILD AND DRY OVER THE CWA.
HIGHS SHOULD BE A LITTLE COOLER FROM THE HIGHS ON WED...HOWEVER MOST
LOCATIONS SHOULD STILL BE IN THE MID 50S.
OPERATIONAL GUIDANCE IS IN DECENT AGREEMENT ON GENERAL TIMING/TRACK
OF TROUGH AS IS MOVES FROM THE SW US AND ACROSS SOUTHERN KANSAS
FRIDAY THROUGH SATURDAY...WITH CLOSED CENTER MOVING ACROSS SOUTHERN
KS. THIS COULD PUT OUR EASTERN CWA NEAR POSSIBLE DEFORMATION
ZONE/HEAVY SNOW BAND FRIDAY NIGHT. GEFS ENSEMBLES STILL SHOWING
GREATER SPREAD WITH GEFS MEAN MUCH SLOWER AND LESS AMPLIFIED AS A
RESULT. THERE HASNT BE A LOT OF RUN TO RUN CONTINUITY THE LAST FEW
DAYS...SO A LOT CAN STILL CHANGE CONSIDERING THE TIME RANGE. BASED
ON CURRENT RUNS IT DOES APPEAR CHANCES FOR A WINTER STORM DEVELOPING
OVER PARTS OF KANSAS COULD BE INCREASING. FOR OUR CWA THE FAVORED
LOCATIONS WOULD BE ACROSS THE EAST WHERE LIGHT SNOW ACCUMULATIONS
ARE POSSIBLE. I DID INCREASE POPS TO 40 ACROSS THE EAST THIS
FORECAST CYCLE...WITH CONFIDENCE TOO LOW TO GO MUCH HIGHER.
THERE IS SIGNIFICANT SPREAD IN THE UPPER LEVEL PATTERN AFTER THIS
SYSTEM SHIFTS EAST. GEFS AND GFS ARE GENERALLY SHOWING A
WESTERLY/ZONAL PATTERN ...WHILE ECMWF IS TRYING TO SHOW A MUCH MORE
PROGRESSIVE/ACTIVE PATTERN. REGARDLESS OF SOLUTION IT DOES APPEAR
THE ACTIVE STORM TRACK IS FAVORING AREAS OUTSIDE OF OUR CWA...SO IM
KEEPING LATER PERIODS DRY FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1026 AM MST MON DEC 10 2012
VFR EXPECTED AT BOTH KGLD AND KMCK THROUGH THE TAF PERIOD.
SCATTERED MID LEVEL CLOUDS WILL ACCOMPANY A WEAK SHORTWAVE TROUGH
THROUGH THIS EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...024
SHORT TERM...JRM
LONG TERM...JRM/DR
AVIATION...024
AREA FORECAST DISCUSSION
NWS GOODLAND KS
923 AM MST MON DEC 10 2012
.UPDATE...
ISSUED AT 922 AM MST MON DEC 10 2012
EXPIRED WIND CHILL ADVISORY.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 248 AM MST MON DEC 10 2012
04Z WATER VAPOR IMAGERY INDICATED TROUGH AXIS CENTERED OVER THE
CWA WITH BROAD RIDGING ACROSS THE WEST COAST. RAP DYNAMIC TROPOPAUSE
ANALYSIS INDICATED SHORT WAVE TROUGH MOVING OVER MONTANA...BUT DID
NOT APPEAR TO BE MUCH OF A RESPONSE ON WV IMAGERY. AT THE
SFC...RIDGE AXIS WAS LOCATED ALONG A KITR TO KANW LINE WITH
TEMPERATURES ALREADY IN THE SINGLE DIGITS ACROSS THE AREA.
MAIN SHORT TERM CONCERNS WILL BE WIND CHILLS THIS MORNING FOLLOWED
BY HOW QUICKLY TEMPERATURES RECOVER THROUGH THE MIDDLE OF THE WEEK.
EARLY MORNING HOURS...TEMPS HAVE FALLEN TO SEVERAL DEGREES BELOW
ZERO ACROSS NORTHEAST CWA WITH WINDS AROUND 10 MPH CREATING WIND
CHILLS IN THE -15 TO -20 RANGE. ALTHOUGH SOME SLIGHT WARMING HAS
BEEN NOTED ACROSS EASTERN COLORADO IN RESPONSE TO CONTINUED WESTERLY
FLOW/WAA...WILL LIKELY BE SEVERAL HOURS BEFORE THAT HAS A MEANINGFUL
IMPACT ACROSS NORTHEAST CWA. ALTHOUGH WINDS ARE NOT STRONG...THINK
CURRENT TEMPS WARRANT A WIND CHILL ADVISORY FOR THE MORNING HOURS.
WHILE CONDITIONS HAVE ALREADY OCCURRED ACROSS EASTERN
COLORADO...AFOREMENTIONED WARMING TREND IN OBS LEADS ME TO THINK
THREAT NOT GREAT IN THIS AREA.
TODAY...WEAK SHORT WAVE TROUGH WILL APPROACH FROM THE NORTH THIS
MORNING...BUT WITH VERY STABLE CONDITIONS EXPECTED FROM NEAR TERM
MODELS AND 00Z OBSERVATIONS AM DOUBTFUL THAT THIS INITIAL TROUGH WILL
DO MORE THAN CREATE A FEW HIGH CLOUDS THROUGH THE MORNING HOURS.
MAIN ISSUE TODAY WILL BE THE GUSTY WINDS THIS AFTERNOON AND HOW
QUICKLY TDS RECOVER FROM INITIAL VERY LOW VALUES AS POTENTIAL EXISTS
FOR LOW END CRITICAL FIRE WEATHER CONDITIONS TODAY. WINDS WILL PICK
UP INTO THE 15 TO 25 MPH RANGE DURING THE AFTERNOON...BUT THINK TDS
WILL ACTUALLY RISE SEVERAL DEGREES WITH VERTICAL MIXING. CURRENT
THOUGHTS KEEP THE HIGHEST WINDS AND DRIEST HUMIDITIES NOT VERY
COLOCATED AND WITH POTENTIAL FOR RISING AFTERNOON TDS...DO NOT PLAN
ON ISSUING A RFW AT THE MOMENT.
TONIGHT-TOMORROW...1.5 PVU FIELDS INDICATE SEVERAL SMALL SCALE SHORT
WAVE TROUGHS MOVING THROUGH THE FLOW TONIGHT...WITH STRONGEST (AT
LEAST FROM A PV PERSPECTIVE) COMING THROUGH THE CWA ON TUESDAY. GFS
AND NAM DIFFER ON STABILITY PROFILES OVERNIGHT WITH GFS INDICATING A
POCKET OF NEAR NEUTRAL CONDITIONS ACROSS WESTERN CWA BETWEEN 0 AND
06Z. WHILE NAM IS SLIGHTLY MORE STABLE...POINT SOUNDINGS DO INDICATE
SNOW GROWTH ZONE NOT TO FAR ABOVE THE SURFACE WITH A PERIOD OF ASCENT
MAXIMIZED IN THIS AREA. DO NOT THINK LIFT WILL BE ENOUGH FOR
MEANINGFUL PRECIP...BUT A FLURRY OR TWO DOES NOT LOOK UNREASONABLE.
DESPITE AN APPARENTLY STRONGER TROUGH ON TUESDAY...NEAR GROUND SNOW
GROWTH ZONE DISAPPEARS AND OVERALL PROFILES ARE MUCH MORE
STABLE...SO DO NOT EXPECT FLURRIES TO CARRY ON THROUGH THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 AM MST MON DEC 10 2012
TUESDAY NIGHT-WEDNESDAY NIGHT...QUIET WEATHER EXPECTED FOR THE
PERIOD AS SHORT WAVE RIDGING WILL BUILD OVER THE AREA AS FLOW
BECOMES MORE AMPLIFIED IN RESPONSE TO TROUGH DEVELOPING OVER WEST
COAST. THINK A RAPID WARM UP IS POSSIBLE...WITH TEMPS APPROACHING
UPPER 50S TO LOW 60S BY WEDNESDAY. AM A LITTLE CONCERNED THAT
CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP ON WEDNESDAY AS
DEWPOINTS WILL REMAIN FAIRLY LOW AND NOT UNHEARD OF FOR DEVELOPING
LEE TROUGH TO BRING GUSTY WINDS. RIGHT NOW...THINGS LOOK TOO
MARGINAL FOR POTENTIAL WATCH...BUT WILL KEEP AN EYE ON AS PERIOD
APPROACHES.
THURSDAY-MONDAY...
SW FLOW WILL BE IN PLACE THURSDAY AS DEEP TROUGH DEVELOPS OVER THE
WESTERN US...WHICH SHOULD KEEP CONDITIONS MILD AND DRY OVER THE CWA.
HIGHS SHOULD BE A LITTLE COOLER FROM THE HIGHS ON WED...HOWEVER MOST
LOCATIONS SHOULD STILL BE IN THE MID 50S.
OPERATIONAL GUIDANCE IS IN DECENT AGREEMENT ON GENERAL TIMING/TRACK
OF TROUGH AS IS MOVES FROM THE SW US AND ACROSS SOUTHERN KANSAS
FRIDAY THROUGH SATURDAY...WITH CLOSED CENTER MOVING ACROSS SOUTHERN
KS. THIS COULD PUT OUR EASTERN CWA NEAR POSSIBLE DEFORMATION
ZONE/HEAVY SNOW BAND FRIDAY NIGHT. GEFS ENSEMBLES STILL SHOWING
GREATER SPREAD WITH GEFS MEAN MUCH SLOWER AND LESS AMPLIFIED AS A
RESULT. THERE HASNT BE A LOT OF RUN TO RUN CONTINUITY THE LAST FEW
DAYS...SO A LOT CAN STILL CHANGE CONSIDERING THE TIME RANGE. BASED
ON CURRENT RUNS IT DOES APPEAR CHANCES FOR A WINTER STORM DEVELOPING
OVER PARTS OF KANSAS COULD BE INCREASING. FOR OUR CWA THE FAVORED
LOCATIONS WOULD BE ACROSS THE EAST WHERE LIGHT SNOW ACCUMULATIONS
ARE POSSIBLE. I DID INCREASE POPS TO 40 ACROSS THE EAST THIS
FORECAST CYCLE...WITH CONFIDENCE TOO LOW TO GO MUCH HIGHER.
THERE IS SIGNIFICANT SPREAD IN THE UPPER LEVEL PATTERN AFTER THIS
SYSTEM SHIFTS EAST. GEFS AND GFS ARE GENERALLY SHOWING A
WESTERLY/ZONAL PATTERN ...WHILE ECMWF IS TRYING TO SHOW A MUCH MORE
PROGRESSIVE/ACTIVE PATTERN. REGARDLESS OF SOLUTION IT DOES APPEAR
THE ACTIVE STORM TRACK IS FAVORING AREAS OUTSIDE OF OUR CWA...SO IM
KEEPING LATER PERIODS DRY FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 437 AM MST MON DEC 10 2012
VFR CONDITIONS EXPECTED OVER THE NEXT 24 HOURS WITH GUSTY WEST
WINDS EXPECTED TODAY WITH PERIODS OF SCATTERED TO BROKEN MID LEVEL
CLOUDS. OVERNIGHT CEILINGS WILL FALL TO AROUND 3500 FEET...BUT
WIDESPREAD AND PERSISTENT FLIGHT RESTRICTIONS ARE NOT EXPECTED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...024
SHORT TERM...JRM
LONG TERM...JRM/DR
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
439 AM MST MON DEC 10 2012
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 248 AM MST MON DEC 10 2012
04Z WATER VAPOR IMAGERY INDICATED TROUGH AXIS CENTERED OVER THE
CWA WITH BROAD RIDGING ACROSS THE WEST COAST. RAP DYNAMIC TROPOPAUSE
ANALYSIS INDICATED SHORT WAVE TROUGH MOVING OVER MONTANA...BUT DID
NOT APPEAR TO BE MUCH OF A RESPONSE ON WV IMAGERY. AT THE
SFC...RIDGE AXIS WAS LOCATED ALONG A KITR TO KANW LINE WITH
TEMPERATURES ALREADY IN THE SINGLE DIGITS ACROSS THE AREA.
MAIN SHORT TERM CONCERNS WILL BE WIND CHILLS THIS MORNING FOLLOWED
BY HOW QUICKLY TEMPERATURES RECOVER THROUGH THE MIDDLE OF THE WEEK.
EARLY MORNING HOURS...TEMPS HAVE FALLEN TO SEVERAL DEGREES BELOW
ZERO ACROSS NORTHEAST CWA WITH WINDS AROUND 10 MPH CREATING WIND
CHILLS IN THE -15 TO -20 RANGE. ALTHOUGH SOME SLIGHT WARMING HAS
BEEN NOTED ACROSS EASTERN COLORADO IN RESPONSE TO CONTINUED WESTERLY
FLOW/WAA...WILL LIKELY BE SEVERAL HOURS BEFORE THAT HAS A MEANINGFUL
IMPACT ACROSS NORTHEAST CWA. ALTHOUGH WINDS ARE NOT STRONG...THINK
CURRENT TEMPS WARRANT A WIND CHILL ADVISORY FOR THE MORNING HOURS.
WHILE CONDITIONS HAVE ALREADY OCCURRED ACROSS EASTERN
COLORADO...AFOREMENTIONED WARMING TREND IN OBS LEADS ME TO THINK
THREAT NOT GREAT IN THIS AREA.
TODAY...WEAK SHORT WAVE TROUGH WILL APPROACH FROM THE NORTH THIS
MORNING...BUT WITH VERY STABLE CONDITIONS EXPECTED FROM NEAR TERM
MODELS AND 00Z OBSERVATIONS AM DOUBTFUL THAT THIS INITIAL TROUGH WILL
DO MORE THAN CREATE A FEW HIGH CLOUDS THROUGH THE MORNING HOURS.
MAIN ISSUE TODAY WILL BE THE GUSTY WINDS THIS AFTERNOON AND HOW
QUICKLY TDS RECOVER FROM INITIAL VERY LOW VALUES AS POTENTIAL EXISTS
FOR LOW END CRITICAL FIRE WEATHER CONDITIONS TODAY. WINDS WILL PICK
UP INTO THE 15 TO 25 MPH RANGE DURING THE AFTERNOON...BUT THINK TDS
WILL ACTUALLY RISE SEVERAL DEGREES WITH VERTICAL MIXING. CURRENT
THOUGHTS KEEP THE HIGHEST WINDS AND DRIEST HUMIDITIES NOT VERY
COLOCATED AND WITH POTENTIAL FOR RISING AFTERNOON TDS...DO NOT PLAN
ON ISSUING A RFW AT THE MOMENT.
TONIGHT-TOMORROW...1.5 PVU FIELDS INDICATE SEVERAL SMALL SCALE SHORT
WAVE TROUGHS MOVING THROUGH THE FLOW TONIGHT...WITH STRONGEST (AT
LEAST FROM A PV PERSPECTIVE) COMING THROUGH THE CWA ON TUESDAY. GFS
AND NAM DIFFER ON STABILITY PROFILES OVERNIGHT WITH GFS INDICATING A
POCKET OF NEAR NEUTRAL CONDITIONS ACROSS WESTERN CWA BETWEEN 0 AND
06Z. WHILE NAM IS SLIGHTLY MORE STABLE...POINT SOUNDINGS DO INDICATE
SNOW GROWTH ZONE NOT TO FAR ABOVE THE SURFACE WITH A PERIOD OF ASCENT
MAXIMIZED IN THIS AREA. DO NOT THINK LIFT WILL BE ENOUGH FOR
MEANINGFUL PRECIP...BUT A FLURRIE OR TWO DOES NOT LOOK UNREASONABLE.
DESPITE AN APPARENTLY STRONGER TROUGH ON TUESDAY...NEAR GROUND SNOW
GROWTH ZONE DISAPPEARS AND OVERALL PROFILES ARE MUCH MORE
STABLE...SO DO NOT EXPECT FLURRIES TO CARRY ON THROUGH THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 AM MST MON DEC 10 2012
TUESDAY NIGHT-WEDNESDAY NIGHT...QUIET WEATHER EXPECTED FOR THE
PERIOD AS SHORT WAVE RIDGING WILL BUILD OVER THE AREA AS FLOW
BECOMES MORE AMPLIFIED IN RESPONSE TO TROUGH DEVELOPING OVER WEST
COAST. THINK A RAPID WARM UP IS POSSIBLE...WITH TEMPS APPROACHING
UPPER 50S TO LOW 60S BY WEDNESDAY. AM A LITTLE CONCERNED THAT
CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP ON WEDNESDAY AS
DEWPOINTS WILL REMAIN FAIRLY LOW AND NOT UNHEARD OF FOR DEVELOPING
LEE TROUGH TO BRING GUSTY WINDS. RIGHT NOW...THINGS LOOK TOO
MARGINAL FOR POTENTIAL WATCH...BUT WILL KEEP AN EYE ON AS PERIOD
APPROACHES.
THURSDAY-MONDAY...
SW FLOW WILL BE IN PLACE THURSDAY AS DEEP TROUGH DEVELOPS OVER THE
WESTERN US...WHICH SHOULD KEEP CONDITIONS MILD AND DRY OVER THE CWA.
HIGHS SHOULD BE A LITTLE COOLER FROM THE HIGHS ON WED...HOWEVER MOST
LOCATIONS SHOULD STILL BE IN THE MID 50S.
OPERATIONAL GUIDANCE IS IN DECENT AGREEMENT ON GENERAL TIMING/TRACK
OF TROUGH AS IS MOVES FROM THE SW US AND ACROSS SOUTHERN KANSAS
FRIDAY THROUGH SATURDAY...WITH CLOSED CENTER MOVING ACROSS SOUTHERN
KS. THIS COULD PUT OUR EASTERN CWA NEAR POSSIBLE DEFORMATION
ZONE/HEAVY SNOW BAND FRIDAY NIGHT. GEFS ENSEMBLES STILL SHOWING
GREATER SPREAD WITH GEFS MEAN MUCH SLOWER AND LESS AMPLIFIED AS A
RESULT. THERE HASNT BE A LOT OF RUN TO RUN CONTINUITY THE LAST FEW
DAYS...SO A LOT CAN STILL CHANGE CONSIDERING THE TIME RANGE. BASED
ON CURRENT RUNS IT DOES APPEAR CHANCES FOR A WINTER STORM DEVELOPING
OVER PARTS OF KANSAS COULD BE INCREASING. FOR OUR CWA THE FAVORED
LOCATIONS WOULD BE ACROSS THE EAST WHERE LIGHT SNOW ACCUMULATIONS
ARE POSSIBLE. I DID INCREASE POPS TO 40 ACROSS THE EAST THIS
FORECAST CYCLE...WITH CONFIDENCE TOO LOW TO GO MUCH HIGHER.
THERE IS SIGNIFICANT SPREAD IN THE UPPER LEVEL PATTERN AFTER THIS
SYSTEM SHIFTS EAST. GEFS AND GFS ARE GENERALLY SHOWING A
WESTERLY/ZONAL PATTERN ...WHILE ECMWF IS TRYING TO SHOW A MUCH MORE
PROGRESSIVE/ACTIVE PATTERN. REGARDLESS OF SOLUTION IT DOES APPEAR
THE ACTIVE STORM TRACK IS FAVORING AREAS OUTSIDE OF OUR CWA...SO IM
KEEPING LATER PERIODS DRY FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 437 AM MST MON DEC 10 2012
VFR CONDITIONS EXPECTED OVER THE NEXT 24 HOURS WITH GUSTY WEST
WINDS EXPECTED TODAY WITH PERIODS OF SCATTERED TO BROKEN MID LEVEL
CLOUDS. OVERNIGHT CEILINGS WILL FALL TO AROUND 3500 FEET...BUT
WIDESPREAD AND PERSISTENT FLIGHT RESTRICTIONS ARE NOT EXPECTED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND CHILL ADVISORY UNTIL 8 AM MST /9 AM CST/ THIS MORNING FOR
KSZ001>003-013>015.
CO...NONE.
NE...WIND CHILL ADVISORY UNTIL 8 AM MST /9 AM CST/ THIS MORNING FOR
NEZ079>081.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/DR
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
249 AM MST MON DEC 10 2012
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 248 AM MST MON DEC 10 2012
04Z WATER VAPOR IMAGERY INDICATED TROUGH AXIS CENTERED OVER THE
CWA WITH BROAD RIDGING ACROSS THE WEST COAST. RAP DYNAMIC TROPOPAUSE
ANALYSIS INDICATED SHORT WAVE TROUGH MOVING OVER MONTANA...BUT DID
NOT APPEAR TO BE MUCH OF A RESPONSE ON WV IMAGERY. AT THE
SFC...RIDGE AXIS WAS LOCATED ALONG A KITR TO KANW LINE WITH
TEMPERATURES ALREADY IN THE SINGLE DIGITS ACROSS THE AREA.
MAIN SHORT TERM CONCERNS WILL BE WIND CHILLS THIS MORNING FOLLOWED
BY HOW QUICKLY TEMPERATURES RECOVER THROUGH THE MIDDLE OF THE WEEK.
EARLY MORNING HOURS...TEMPS HAVE FALLEN TO SEVERAL DEGREES BELOW
ZERO ACROSS NORTHEAST CWA WITH WINDS AROUND 10 MPH CREATING WIND
CHILLS IN THE -15 TO -20 RANGE. ALTHOUGH SOME SLIGHT WARMING HAS
BEEN NOTED ACROSS EASTERN COLORADO IN RESPONSE TO CONTINUED WESTERLY
FLOW/WAA...WILL LIKELY BE SEVERAL HOURS BEFORE THAT HAS A MEANINGFUL
IMPACT ACROSS NORTHEAST CWA. ALTHOUGH WINDS ARE NOT STRONG...THINK
CURRENT TEMPS WARRANT A WIND CHILL ADVISORY FOR THE MORNING HOURS.
WHILE CONDITIONS HAVE ALREADY OCCURRED ACROSS EASTERN
COLORADO...AFOREMENTIONED WARMING TREND IN OBS LEADS ME TO THINK
THREAT NOT GREAT IN THIS AREA.
TODAY...WEAK SHORT WAVE TROUGH WILL APPROACH FROM THE NORTH THIS
MORNING...BUT WITH VERY STABLE CONDITIONS EXPECTED FROM NEAR TERM
MODELS AND 00Z OBSERVATIONS AM DOUBTFUL THAT THIS INITIAL TROUGH WILL
DO MORE THAN CREATE A FEW HIGH CLOUDS THROUGH THE MORNING HOURS.
MAIN ISSUE TODAY WILL BE THE GUSTY WINDS THIS AFTERNOON AND HOW
QUICKLY TDS RECOVER FROM INITIAL VERY LOW VALUES AS POTENTIAL EXISTS
FOR LOW END CRITICAL FIRE WEATHER CONDITIONS TODAY. WINDS WILL PICK
UP INTO THE 15 TO 25 MPH RANGE DURING THE AFTERNOON...BUT THINK TDS
WILL ACTUALLY RISE SEVERAL DEGREES WITH VERTICAL MIXING. CURRENT
THOUGHTS KEEP THE HIGHEST WINDS AND DRIEST HUMIDITIES NOT VERY
COLOCATED AND WITH POTENTIAL FOR RISING AFTERNOON TDS...DO NOT PLAN
ON ISSUING A RFW AT THE MOMENT.
TONIGHT-TOMORROW...1.5 PVU FIELDS INDICATE SEVERAL SMALL SCALE SHORT
WAVE TROUGHS MOVING THROUGH THE FLOW TONIGHT...WITH STRONGEST (AT
LEAST FROM A PV PERSPECTIVE) COMING THROUGH THE CWA ON TUESDAY. GFS
AND NAM DIFFER ON STABILITY PROFILES OVERNIGHT WITH GFS INDICATING A
POCKET OF NEAR NEUTRAL CONDITIONS ACROSS WESTERN CWA BETWEEN 0 AND
06Z. WHILE NAM IS SLIGHTLY MORE STABLE...POINT SOUNDINGS DO INDICATE
SNOW GROWTH ZONE NOT TO FAR ABOVE THE SURFACE WITH A PERIOD OF ASCENT
MAXIMIZED IN THIS AREA. DO NOT THINK LIFT WILL BE ENOUGH FOR
MEANINGFUL PRECIP...BUT A FLURRIE OR TWO DOES NOT LOOK UNREASONABLE.
DESPITE AN APPARENTLY STRONGER TROUGH ON TUESDAY...NEAR GROUND SNOW
GROWTH ZONE DISAPPEARS AND OVERALL PROFILES ARE MUCH MORE
STABLE...SO DO NOT EXPECT FLURRIES TO CARRY ON THROUGH THE DAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 248 AM MST MON DEC 10 2012
TUESDAY NIGHT-WEDNESDAY NIGHT...QUIET WEATHER EXPECTED FOR THE
PERIOD AS SHORT WAVE RIDGING WILL BUILD OVER THE AREA AS FLOW
BECOMES MORE AMPLIFIED IN RESPONSE TO TROUGH DEVELOPING OVER WEST
COAST. THINK A RAPID WARM UP IS POSSIBLE...WITH TEMPS APPROACHING
UPPER 50S TO LOW 60S BY WEDNESDAY. AM A LITTLE CONCERNED THAT
CRITICAL FIRE WEATHER CONDITIONS WILL DEVELOP ON WEDNESDAY AS
DEWPOINTS WILL REMAIN FAIRLY LOW AND NOT UNHEARD OF FOR DEVELOPING
LEE TROUGH TO BRING GUSTY WINDS. RIGHT NOW...THINGS LOOK TOO
MARGINAL FOR POTENTIAL WATCH...BUT WILL KEEP AN EYE ON AS PERIOD
APPROACHES.
THURSDAY-MONDAY...
SW FLOW WILL BE IN PLACE THURSDAY AS DEEP TROUGH DEVELOPS OVER THE
WESTERN US...WHICH SHOULD KEEP CONDITIONS MILD AND DRY OVER THE CWA.
HIGHS SHOULD BE A LITTLE COOLER FROM THE HIGHS ON WED...HOWEVER MOST
LOCATIONS SHOULD STILL BE IN THE MID 50S.
OPERATIONAL GUIDANCE IS IN DECENT AGREEMENT ON GENERAL TIMING/TRACK
OF TROUGH AS IS MOVES FROM THE SW US AND ACROSS SOUTHERN KANSAS
FRIDAY THROUGH SATURDAY...WITH CLOSED CENTER MOVING ACROSS SOUTHERN
KS. THIS COULD PUT OUR EASTERN CWA NEAR POSSIBLE DEFORMATION
ZONE/HEAVY SNOW BAND FRIDAY NIGHT. GEFS ENSEMBLES STILL SHOWING
GREATER SPREAD WITH GEFS MEAN MUCH SLOWER AND LESS AMPLIFIED AS A
RESULT. THERE HASNT BE A LOT OF RUN TO RUN CONTINUITY THE LAST FEW
DAYS...SO A LOT CAN STILL CHANGE CONSIDERING THE TIME RANGE. BASED
ON CURRENT RUNS IT DOES APPEAR CHANCES FOR A WINTER STORM DEVELOPING
OVER PARTS OF KANSAS COULD BE INCREASING. FOR OUR CWA THE FAVORED
LOCATIONS WOULD BE ACROSS THE EAST WHERE LIGHT SNOW ACCUMULATIONS
ARE POSSIBLE. I DID INCREASE POPS TO 40 ACROSS THE EAST THIS
FORECAST CYCLE...WITH CONFIDENCE TOO LOW TO GO MUCH HIGHER.
THERE IS SIGNIFICANT SPREAD IN THE UPPER LEVEL PATTERN AFTER THIS
SYSTEM SHIFTS EAST. GEFS AND GFS ARE GENERALLY SHOWING A
WESTERLY/ZONAL PATTERN ...WHILE ECMWF IS TRYING TO SHOW A MUCH MORE
PROGRESSIVE/ACTIVE PATTERN. REGARDLESS OF SOLUTION IT DOES APPEAR
THE ACTIVE STORM TRACK IS FAVORING AREAS OUTSIDE OF OUR CWA...SO IM
KEEPING LATER PERIODS DRY FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1036 PM MST SUN DEC 9 2012
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. LIGHT WEST WINDS
WILL INCREASE DURING THE MORNING AFTER THE SUN COMES UP AND BECOME
GUSTY UNTIL LATE IN THE AFTERNOON. EVEN THOUGH CEILINGS WILL BE
VFR...CEILINGS WILL BEGIN TO LOWER LATE IN THE AFTERNOON INTO THE
EVENING HOURS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND CHILL ADVISORY UNTIL 8 AM MST /9 AM CST/ THIS MORNING FOR
KSZ001>003-013>015.
CO...NONE.
NE...WIND CHILL ADVISORY UNTIL 8 AM MST /9 AM CST/ THIS MORNING FOR
NEZ079>081.
&&
$$
SHORT TERM...JRM
LONG TERM...JRM/DR
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1147 PM CST SUN DEC 9 2012
...UPDATE TO AVIATION...
.DISCUSSION...
20Z WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH FROM THE FOUR
CORNERS REGION INTO THE DAKOTAS. ONE SHORTWAVE WAS LIFTING
NORTHEAST INTO MN WITH ANOTHER SHORTWAVE OVER THE CO AND NM
ROCKIES. AT THE SURFACE...A VERY STRONG COLD FRONT HAS PUSHED
SOUTH INTO NORTH TX AND EAST INTO CENTRAL MO. AREA OBSERVATIONS
INDICATE STRONG COLD AND DRY AIR ADVECTION IS ONGOING. RADAR
TRENDS THROUGHOUT THE DAY HAVE SUPPORTED THE IDEA THAT THE DRY AIR
NEAR THE SURFACE IS TO MUCH FOR WEAK FRONTOGENESIS IN THE MID
LEVELS TO OVERCOME.
FOR TONIGHT AND MONDAY...MODELS SHOW LITTLE OR NO LARGE SCALE
FORCING THROUGH THE PERIOD WITH THE ONLY INDICATION OF FORCING FOR
PRECIP BEING WEAK MID LEVEL FRONTOGENESIS THROUGH THE EARLY EVENING.
GIVEN THE CONTINUED ADVECTION OF DRY AIR IN THE LOWER TROPOSPHERE...
THINK PRECIP CHANCES ARE PRETTY CLOSE TO NIL. BY MONDAY...THE COLD
SURFACE RIDGE OF HIGH PRESSURE WITH VERY DRY AIR IS EXPECTED TO
DOMINATE THE WEATHER AS THE SHORTWAVE OVER THE SOUTHERN ROCKIES
PASSES MAINLY TO THE SOUTH OF THE FORECAST AREA. THEREFORE THE
FORECAST WILL REMAIN DRY. ABOUT THE ONLY WEATHER CONCERN IS CLOUD
COVER OVERNIGHT. VISIBLE SATELLITE SHOWS AN AREA OF STRATOCU MOVING
SWIFTLY SOUTH ACROSS EASTERN NEB. THE RAP SHOWS THIS DECK OF LOW
CLOUDS HANGING IN ACROSS NORTHEAST AND EAST CENTRAL KS THROUGH MUCH
OF THE NIGHT...AND THE NAM AND GFS TO A LESSER EXTENT SUPPORT THE
IDEA. SO THINK SKIES WILL BE MOSTLY CLOUDY TONIGHT. BECAUSE OF THIS
HAVE KEPT LOWS A DEGREE OR TWO WARMER THAN THE MOS GUIDANCE ACROSS
EASTERN KS. ADDITIONALLY A STRONGLY MIXED BOUNDARY LAYER SHOULD HELP
KEEP LOWS FROM PLUMMETING. NORTH CENTRAL KS COULD SEE SINGLE DIGIT
LOWS WHERE SKIES SHOULD CLEAR OUT SOONER. WITH SUCH A COLD START TO
THE DAY...HIGHS ARE EXPECTED TO ONLY MAKE IT INTO THE LOWER AND MID
30S FOR MONDAY EVEN WITH MOSTLY SUNNY SKIES.
WOLTERS
MID WEEK PERIODS LOOKING RATHER BENIGN. SOME MID AND HIGH CLOUDS
SHOULD BE ALL THAT RESULTS FROM THE NEXT UPPER WAVE PASSING THROUGH
THE CENTRAL PLAINS MONDAY NIGHT INTO EARLY TUESDAY. LOW LEVEL FLOW
REMAINS MAINLY WESTERLY TUESDAY FOR WEAK WARM AIR ADVECTION...AND
WAA INCREASES INTO WEDNESDAY AND THURSDAY AS BROAD RIDGING OVERTAKES
THE CENTRAL AND EASTERN CONUS. THE DEGREE OF MIXING INTO THE WARM
AND DRY MID LEVELS IS THE MAIN QUESTION FOR HOW WARM HIGHS WILL GET.
BUMPED THEM UP A FEW DEGREES AT THIS POINT BUT FURTHER INCREASES MAY
BE NEEDED. SSW WINDS INCREASE FOR WEDNESDAY INTO THURSDAY AND
RELATIVE HUMIDITIES MAY DROP TO LEVELS OF SOME CONCERN FOR FIRE
WEATHER MAINLY ON WEDNESDAY.
MEDIUM RANGE MODELS ARE IN DECENT AGREEMENT WITH WESTERN TROF AND
UPPER LOW IN THE SOUTHWEST CONUS ON THURSDAY...BUT DIFFERENCES
MAGNIFY QUICKLY INTO THE WEEKEND. THE 12Z ECMWF PUSHES THE LOW EAST
AHEAD OF THE NORTHERN TROF AND ALLOWS A LOW TO RE-CLOSE AND DEEPEN
RAPIDLY OVER THE CENTRAL PLAINS...WHILE THE 12Z GFS KEEPS THE
SOUTHERN LOW BEHIND THE NORTHERN TROF FOR A WEAKENING WAVE IN THE
PLAINS. MODERATE PRECIPITATION CHANCES REMAIN...CENTERED AROUND
FRIDAY NIGHT...WITH SOME OPPORTUNITY FOR CONVECTION IN THE MORE
AMPLIFIED SOLUTIONS AND MINOR CONCERN FOR WINTRY PRECIP AS THE EVENT
WINDS DOWN. TEMPS SHOULD RETURN TO NEAR MID-DECEMBER NORMALS FOR
SUNDAY.
65
&&
.AVIATION...
A VFR STRATUS BAND (CEILINGS OF 3,200 TO 3,500 FEET) WAS OVER KTOP
AND KFOE...THE CEILINGS DROP ABOUT 1,000 FEE ON THE TRAILING EDGE
OF THE STRATUS FROM KMHK TO KCNK. CEILINGS AT KTOP AND KFOE WILL
DROP TO MVFR FOR A FEW HOURS BETWEEN 6Z AND 8Z...THEN SKIES WILL
CLEAR AFTER 8Z. SKIES SHOULD CLEAR AT KMHK AFTER 7Z. NORTHWEST
WINDS WILL DIMINISH UNDER 10 KTS THROUGH THE DAY.
GARGAN
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
947 PM EST TUE DEC 11 2012
.SYNOPSIS...
A FRONTAL BOUNDARY STALLS OVER THE EASTERN CAROLINAS TONIGHT AS
HIGH PRESSURE SLOWLY BUILDS IN FROM THE NORTHWEST. A WAVE OF LOW
PRESSURE WILL DEVELOP ALONG THE FRONT WEDNESDAY...PUSHING FARTHER
OFFSHORE WEDNESDAY NIGHT INTO THURSDAY. HIGH PRESSURE REMAINS IN
PLACE OVER THE MID ATLANTIC THROUGH THE END OF THIS WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
A COLD FRNT INTO ERN NC WHILE HI PRES SLOWLY BLDS IN FROM THE NW.
STRONG LO-LVL INVERSION AND ASSOCIATED MOISTURE WILL KEEP SKIES
MSTLY CLDY THIS EVENG AND OVRNGT...WITH THE LO STRATUS AND HI
TEMP-DEWPT SPREADS PREVENTING FOG FORMATION. STRONG SW FLOW ABOVE
THE INVERSION MAY PROVIDE JUST ENUF (ISENTROPIC) LIFT TO LEAD TO
-RA OVER EXTREME SE VA/NE NC AS MOST MODELS INDICATE...POPS 30% AT
ORF...50% OVER NE NC. LOOKING AT RAP MODEL AND OBSERVATIONS WILL
DELAY THE HIGHER POPS UNTIL AFTER MIDNIGHT AS RAIN ONLY SLOWLY
WORKING NORTHEAST. RAIN CHCS INCREASE TO LIKELY OVER THESE AREAS
INTO WED AS THREAT FOR OVERRUNING PRECIP CONTINUES AND A WAVE OF
LO PRES DEVELOPS ALONG THE STALLED FRNT. TOTAL AMOUNTS SHUD STAY
BLO ONE- QUARTER OF AN INCH DUE TO WEAK LIFT. ONLY A 20% CHC OF
RAIN MAKING IN UP TO RIC/SBY. OTHERWISE...MSTLY CLDY TO CLDY SKIES
FOR THE DAY. LO TEMPS TNGT RANGE FROM THE LWR 30S NW TO LWR 40S
SE...WITH HI TEMPS WED IN THE UPR 40S TO LWR 50S.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
SOME -RA MAY LINGER INTO WED NGT AS LO PRES AND ASSOCIATED FRNTAL
BNDRY PUSH FARTHER OFFSHORE. CONFINED POPS TO SE VA/NE NC AFTER
MIDNGT. DECREASING CLDS AS WELL (TO MSTLY CLR) AS LO TEMPS RANGE
FROM NEAR 30 OVER THE PIEDMONT TO NEAR 40 ALONG THE COAST. ~1030
MB SFC HI PRES BLDS DIRECTLY OVER THE MID-ATLANTIC THU...AND
STAYING PUT INTO FRI. THIS WILL LEAD TO A SNY SKY AND SEASONABLE
TEMPS WITH HIGHS IN THE LWR TO MID 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SFC HI PRES INVOF MDATLC STATES FRI NGT IS SLO TO WEAKEN...DRIFT
OFF THE CST SAT. MDT SFC LO PRES TRACKS INTO/THROUGH THE LAKES RGN
SUN INTO MON...PUSHING ASSOCD CDFNT ACRS THE MDATLC RGN. PCPN
PTNTL LOOKS LESS THAN THAT FM PAST CPL DAYS...HAVE CAPPED POPS ABT
30%). DRYING OUT/SEASONABLE WX FM MON AFTN THROUGH TUE. ANOTHER
STORM SYS MAY APPROACH FM THE WSW BY MID NEXT WK.
MILDER SAT...BFR COOLING DOWN (TO AT OR SLGTLY BLO NRML) SUN
THROUGH TUE.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
DEVELOPING LOW PRESSURE ALONG COLD FRONT ACROSS SOUTHERN NORTH
CAROLINA AND SOUTH CAROLINA WILL SPREAD RAIN ACROSS SE PORTION OF
OUR AREA...MAINLY AROUND MIDDAY WEDNESDAY. SOME OF THIS RAIN MAY
REACH ECG DURING THE EARLY MORNING.
AS OF 00Z...MVFR CIGS WERE OVER A NARROW AREA OF NE NORTH CAROLINA
AND EXTREME SE VIRGINIA INCLUDING KECG. CURRENT AND RECENT
CONDITIONS CONTINUES TO BE HANDLED WELL BY THE NAM BUFR SOUNDINGS
AND WILL MAINTAIN MVFR AT ECG OVERNIGHT AND INTO MUCH OF WED. THIS
ALSO HAS ECG DROPPING TO IFR CIGS AROUND MIDDAY WEDNESDAY. HAVE KORF
GOING DOWN TO MVFR BRIEFLY WITH THE RAIN WEDNESDAY. THE SAME HAS
CONDITIONS IMPROVE LATE WEDNESDAY AFTN AS THE LOW PULLS FURTHER
OFFSHORE.
OUTLOOK...HIGH PRESSURE BUILDS INTO THE MID ATLANTIC STATES AND
DOMINATES THE WEATHER INTO THE WEEKEND. VFR AND DRY WEATHER IS
EXPECTED THURSDAY THROUGH SUNDAY.
&&
.MARINE...
FNTL BNDRY HAS STALLED JUST OFF CSTL CAROLINAS...AND WILL RMN NRLY
STNRY INTO THU. WK SFC LO PRES DVLPS...AND EVENTUALLY TRACKS ENE
ALG THE BNDRY...WHILE MDT SFC HI PRES SETTLES INVOF NE CONUS. THE
RESULT WILL BE A PD OF MDT NNE WNDS (GUSTS TO 25-30 KT
PSBL...HIGHEST ON THE OCN)...AND ASSOCD BUILDING WAVES/SEAS (ESP NR
THE MOUTH OF THE BAY...AND CAPE CHARLES LGT ON S). SCAS WILL RMN
UP ON THE SRN OCN WTRS THROUGH THU...AND WILL RAISE SCAS ON THE
SRN BAY AND SND FOR WED MRNG THROUGH THU. HI PRES EVENTUALLY
BUILDS OVR THE WTRS LT WK...AND WEAKENS ERY IN THE WKND...BRINGING
LWRG WNDS AND WAVES/SEAS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM WEDNESDAY TO 6 PM EST THURSDAY
FOR ANZ632>634-654.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ656-658.
&&
$$
SYNOPSIS...MAS
NEAR TERM...MAS/JAB
SHORT TERM...MAS
LONG TERM...ALB
AVIATION...LSA
MARINE...ALB
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
750 PM EST TUE DEC 11 2012
.SYNOPSIS...
A FRONTAL BOUNDARY STALLS OVER THE EASTERN CAROLINAS TONIGHT AS
HIGH PRESSURE SLOWLY BUILDS IN FROM THE NORTHWEST. A WAVE OF LOW
PRESSURE WILL DEVELOP ALONG THE FRONT WEDNESDAY...PUSHING FARTHER
OFFSHORE WEDNESDAY NIGHT INTO THURSDAY. HIGH PRESSURE REMAINS IN
PLACE OVER THE MID ATLANTIC THROUGH THE END OF THIS WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
LATEST SFC ANALYSIS SHOWS A COLD FRNT DROPPING INTO ERN NC WHILE HI
PRES SLOWLY BLDS IN FROM THE NW. STRONG LO-LVL INVERSION AND
ASSOCIATED MOISTURE WILL KEEP SKIES MSTLY CLDY THIS EVENG AND
OVRNGT...WITH THE LO STRATUS AND HI TEMP-DEWPT SPREADS PREVENTING
FOG FORMATION. STRONG SW FLOW ABOVE THE INVERSION MAY PROVIDE JUST
ENUF (ISENTROPIC) LIFT TO LEAD TO -RA OVER EXTREME SE VA/NE NC AS
MOST MODELS INDICATE...POPS 30% AT ORF...50% OVER NE NC. LOOKING
AT RAP MODEL AND OBSERVATIONS WILL DELAY THE HIGHER POPS UNTIL
AFTER MIDNIGHT AS RAIN ONLY SLOWLY WORKING NORTHEAST. RAIN CHCS
INCREASE TO LIKELY OVER THESE AREAS INTO WED AS THREAT FOR
OVERRUNING PRECIP CONTINUES AND A WAVE OF LO PRES DEVELOPS ALONG
THE STALLED FRNT. TOTAL AMOUNTS SHUD STAY BLO ONE- QUARTER OF AN
INCH DUE TO WEAK LIFT. ONLY A 20% CHC OF RAIN MAKING IN UP TO
RIC/SBY. OTHERWISE...MSTLY CLDY TO CLDY SKIES FOR THE DAY. LO
TEMPS TNGT RANGE FROM THE LWR 30S NW TO LWR 40S SE...WITH HI TEMPS
WED IN THE UPR 40S TO LWR 50S.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
SOME -RA MAY LINGER INTO WED NGT AS LO PRES AND ASSOCIATED FRNTAL
BNDRY PUSH FARTHER OFFSHORE. CONFINED POPS TO SE VA/NE NC AFTER
MIDNGT. DECREASING CLDS AS WELL (TO MSTLY CLR) AS LO TEMPS RANGE
FROM NEAR 30 OVER THE PIEDMONT TO NEAR 40 ALONG THE COAST. ~1030
MB SFC HI PRES BLDS DIRECTLY OVER THE MID-ATLANTIC THU...AND
STAYING PUT INTO FRI. THIS WILL LEAD TO A SNY SKY AND SEASONABLE
TEMPS WITH HIGHS IN THE LWR TO MID 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SFC HI PRES INVOF MDATLC STATES FRI NGT IS SLO TO WEAKEN...DRIFT
OFF THE CST SAT. MDT SFC LO PRES TRACKS INTO/THROUGH THE LAKES RGN
SUN INTO MON...PUSHING ASSOCD CDFNT ACRS THE MDATLC RGN. PCPN
PTNTL LOOKS LESS THAN THAT FM PAST CPL DAYS...HAVE CAPPED POPS ABT
30%). DRYING OUT/SEASONABLE WX FM MON AFTN THROUGH TUE. ANOTHER
STORM SYS MAY APPROACH FM THE WSW BY MID NEXT WK.
MILDER SAT...BFR COOLING DOWN (TO AT OR SLGTLY BLO NRML) SUN
THROUGH TUE.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
DEVELOPING LOW PRESSURE ALONG COLD FRONT ACROSS SOUTHERN NORTH
CAROLINA AND SOUTH CAROLINA WILL SPREAD RAIN ACROSS SE PORTION OF
OUR AREA...MAINLY AROUND MIDDAY WEDNESDAY. SOME OF THIS RAIN MAY
REACH ECG DURING THE EARLY MORNING.
AS OF 00Z...MVFR CIGS WERE OVER A NARROW AREA OF NE NORTH CAROLINA
AND EXTREME SE VIRGINIA INCLUDING KECG. CURRENT AND RECENT
CONDITIONS CONTINUES TO BE HANDLED WELL BY THE NAM BUFR SOUNDINGS
AND WILL MAINTAIN MVFR AT ECG OVERNIGHT AND INTO MUCH OF WED. THIS
ALSO HAS ECG DROPPING TO IFR CIGS AROUND MIDDAY WEDNESDAY. HAVE KORF
GOING DOWN TO MVFR BRIEFLY WITH THE RAIN WEDNESDAY. THE SAME HAS
CONDITIONS IMPROVE LATE WEDNESDAY AFTN AS THE LOW PULLS FURTHER
OFFSHORE.
OUTLOOK...HIGH PRESSURE BUILDS INTO THE MID ATLANTIC STATES AND
DOMINATES THE WEATHER INTO THE WEEKEND. VFR AND DRY WEATHER IS
EXPECTED THURSDAY THROUGH SUNDAY.
&&
.MARINE...
FNTL BNDRY HAS STALLED JUST OFF CSTL CAROLINAS...AND WILL RMN NRLY
STNRY INTO THU. WK SFC LO PRES DVLPS...AND EVENTUALLY TRACKS ENE
ALG THE BNDRY...WHILE MDT SFC HI PRES SETTLES INVOF NE CONUS. THE
RESULT WILL BE A PD OF MDT NNE WNDS (GUSTS TO 25-30 KT
PSBL...HIGHEST ON THE OCN)...AND ASSOCD BUILDING WAVES/SEAS (ESP NR
THE MOUTH OF THE BAY...AND CAPE CHARLES LGT ON S). SCAS WILL RMN
UP ON THE SRN OCN WTRS THROUGH THU...AND WILL RAISE SCAS ON THE
SRN BAY AND SND FOR WED MRNG THROUGH THU. HI PRES EVENTUALLY
BUILDS OVR THE WTRS LT WK...AND WEAKENS ERY IN THE WKND...BRINGING
LWRG WNDS AND WAVES/SEAS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM WEDNESDAY TO 6 PM EST THURSDAY
FOR ANZ632>634-654.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ656-658.
&&
$$
SYNOPSIS...MAS
NEAR TERM...MAS/JAB
SHORT TERM...MAS
LONG TERM...ALB
AVIATION...LSA
MARINE...ALB
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
656 PM EST TUE DEC 11 2012
.SYNOPSIS...
A FRONTAL BOUNDARY STALLS OVER THE EASTERN CAROLINAS TONIGHT AS
HIGH PRESSURE SLOWLY BUILDS IN FROM THE NORTHWEST. A WAVE OF LOW
PRESSURE WILL DEVELOP ALONG THE FRONT WEDNESDAY...PUSHING FARTHER
OFFSHORE WEDNESDAY NIGHT INTO THURSDAY. HIGH PRESSURE REMAINS IN
PLACE OVER THE MID ATLANTIC THROUGH THE END OF THIS WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
LATEST SFC ANALYSIS SHOWS A COLD FRNT DROPPING INTO ERN NC WHILE HI
PRES SLOWLY BLDS IN FROM THE NW. STRONG LO-LVL INVERSION AND
ASSOCIATED MOISTURE WILL KEEP SKIES MSTLY CLDY THIS EVENG AND
OVRNGT...WITH THE LO STRATUS AND HI TEMP-DEWPT SPREADS PREVENTING
FOG FORMATION. STRONG SW FLOW ABOVE THE INVERSION MAY PROVIDE JUST
ENUF (ISENTROPIC) LIFT TO LEAD TO -RA OVER EXTREME SE VA/NE NC AS
MOST MODELS INDICATE...POPS 30% AT ORF...50% OVER NE NC. LOOKING
AT RAP MODEL AND OBSERVATIONS WILL DELAY THE HIGHER POPS UNTIL
AFTER MIDNIGHT AS RAIN ONLY SLOWLY WORKING NORTHEAST. RAIN CHCS
INCREASE TO LIKELY OVER THESE AREAS INTO WED AS THREAT FOR
OVERRUNING PRECIP CONTINUES AND A WAVE OF LO PRES DEVELOPS ALONG
THE STALLED FRNT. TOTAL AMOUNTS SHUD STAY BLO ONE- QUARTER OF AN
INCH DUE TO WEAK LIFT. ONLY A 20% CHC OF RAIN MAKING IN UP TO
RIC/SBY. OTHERWISE...MSTLY CLDY TO CLDY SKIES FOR THE DAY. LO
TEMPS TNGT RANGE FROM THE LWR 30S NW TO LWR 40S SE...WITH HI TEMPS
WED IN THE UPR 40S TO LWR 50S.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
SOME -RA MAY LINGER INTO WED NGT AS LO PRES AND ASSOCIATED FRNTAL
BNDRY PUSH FARTHER OFFSHORE. CONFINED POPS TO SE VA/NE NC AFTER
MIDNGT. DECREASING CLDS AS WELL (TO MSTLY CLR) AS LO TEMPS RANGE
FROM NEAR 30 OVER THE PIEDMONT TO NEAR 40 ALONG THE COAST. ~1030
MB SFC HI PRES BLDS DIRECTLY OVER THE MID-ATLANTIC THU...AND
STAYING PUT INTO FRI. THIS WILL LEAD TO A SNY SKY AND SEASONABLE
TEMPS WITH HIGHS IN THE LWR TO MID 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SFC HI PRES INVOF MDATLC STATES FRI NGT IS SLO TO WEAKEN...DRIFT
OFF THE CST SAT. MDT SFC LO PRES TRACKS INTO/THROUGH THE LAKES RGN
SUN INTO MON...PUSHING ASSOCD CDFNT ACRS THE MDATLC RGN. PCPN
PTNTL LOOKS LESS THAN THAT FM PAST CPL DAYS...HAVE CAPPED POPS ABT
30%). DRYING OUT/SEASONABLE WX FM MON AFTN THROUGH TUE. ANOTHER
STORM SYS MAY APPROACH FM THE WSW BY MID NEXT WK.
MILDER SAT...BFR COOLING DOWN (TO AT OR SLGTLY BLO NRML) SUN
THROUGH TUE.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT HAS PUSHED SOUTH OF THE TAF SITES AND WILL MOVE OFF THE
CAROLINA COAST THIS EVENING. LOW PRESSURE TO FORM ON THE FRONT AND
SPREAD PCPN INTO SE PORTIONS OF THE AREA WEDNESDAY MORNING.
MVFR CIGS ARE IMPROVING FROM N TO S AND NAM BUFR SOUNDINGS HAVE A
GOOD HANDLE. ECG IS EXPECTED TO REMAIN MVFR THIS EVENING AND
OVERNIGHT. LGT RAIN WILL DEVELOP OVER SE PORTIONS WED MRNG AND
CONTINUE INTO WED EVENING. NO SGFNT IFR IS INDICATED BY THE MOS
FCSTS. WILL INCLUDE MORE DETAIL WITH RESPECT TO PCPN AND IMPACT ON
AVIATION CONDITIONS WITH LATER ISSUANCES.
OUTLOOK...HIGH PRESSURE BUILDS INTO THE MID ATLANTIC STATES AND
DOMINATES THE WEATHER INTO THE WEEKEND. VFR AND DRY WEATHER IS
EXPECTED THURSDAY THROUGH SUNDAY.
&&
.MARINE...
FNTL BNDRY HAS STALLED JUST OFF CSTL CAROLINAS...AND WILL RMN NRLY
STNRY INTO THU. WK SFC LO PRES DVLPS...AND EVENTUALLY TRACKS ENE
ALG THE BNDRY...WHILE MDT SFC HI PRES SETTLES INVOF NE CONUS. THE
RESULT WILL BE A PD OF MDT NNE WNDS (GUSTS TO 25-30 KT
PSBL...HIGHEST ON THE OCN)...AND ASSOCD BUILDING WAVES/SEAS (ESP NR
THE MOUTH OF THE BAY...AND CAPE CHARLES LGT ON S). SCAS WILL RMN
UP ON THE SRN OCN WTRS THROUGH THU...AND WILL RAISE SCAS ON THE
SRN BAY AND SND FOR WED MRNG THROUGH THU. HI PRES EVENTUALLY
BUILDS OVR THE WTRS LT WK...AND WEAKENS ERY IN THE WKND...BRINGING
LWRG WNDS AND WAVES/SEAS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM WEDNESDAY TO 6 PM EST THURSDAY
FOR ANZ632>634-654.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ656-658.
&&
$$
SYNOPSIS...MAS
NEAR TERM...MAS/JAB
SHORT TERM...MAS
LONG TERM...ALB
AVIATION...LSA
MARINE...ALB
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
302 PM EST MON DEC 10 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION WEST OF THE BLUE RIDGE LATE
THIS AFTERNOON...AND THEN CROSS THE REMAINDER OF THE AREA EARLY TONIGHT.
HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT THROUGH WEDNESDAY
NIGHT...AND REMAIN THROUGH THE END OF THE WEEK. &&
.NEAR TERM /THROUGH TONIGHT/...
AT 18Z...COLD FRONT HAS MOVED EAST OF KPIT BUT HAS NOT MADE IT TO
W MD. BOTH THE 12Z NAM AND GFS HAVE VERY SIMILAR TIMINGS WITH
FROPA LATE AFTERNOON IN WESTERN HALF OF CWA...IN THE I-95 CORRIDOR EARLY
EVENING 00Z-02Z AND THEN FOR THE CHESAPEAKE BAY SHORTLY AFTER MIDNIGHT.
PCPN WITH THIS FRONT WILL DIMINISH AS IT MOVES ACROSS THE MOUNTAINS
AS NEGATIVE DIFFERENTIAL VORTICITY ADV AS INDICATED IN THE 12Z GFS
H5 FIELDS WILL NOT ADD ITS COMPONENT TO UPWARD MOTION COUPLED WITH AMPLE
NEG MOISTURE ADVECTION IN THE MID LEVELS. SO WHILE MUCH OF THE
AREA WILL SEE SHOWERS WITH THE FROPA...THEY WILL BE ON THE LIGHTER
SIDE. PCPN WILL NOT EXIT THE SE CWA UNTIL LATE TONIGHT. WINDS WILL
BE GUSTY BEHIND THE FRONT TONIGHT.
IN THE WESTERN UPSLOPE REGION...SNOW SHOWERS ARE LIKELY STARTING
AROUND MIDNIGHT AND LASTING UNTIL MID TUE MORNING. SNOW ACCUM
SHOULD BE AROUND ONE INCH WELL UNDER SNOW ADVSRY LEVELS.
&&
.SHORT TERM /TUESDAY/...
THE FRONT HANGS UP A BIT IN THE EARLY MORNING IN THE
SOUTHEASTERNMOST PORTION OF OUR CWA...WHICH WILL CAUSE CLOUDS TO
LINGER BUT I BELIEVE THAT THE SHRA WILL BE EAST OF THE MD PORTION
OF THE BAY BY DAYBREAK.
ELSEWHERE...A SUNNY START BEFORE HIGH CLOUDS WORK INTO THE REGION
BY MIDDAY AS INDICATED BY RH 80% OR HIGHER AOA H4 STREAMING FROM
THE GULF OF MEXICO AND ALSO BEING IN THE RR QUAD OF UPPER LEVEL
JET. AREAS W OF I-81 WILL BE ON THE WESTERN FRINGE OF THESE HIGH
CLOUDS...AND MAY EVEN EXPERIENCE PRETTY MUCH MOSTLY SUNNY SKIES
ALL DAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
SURFACE HIGH PRESSURE SETTLES OVER THE MID-ATLANTIC TUESDAY NIGHT
THROUGH THURSDAY. AN UPPER LEVEL DISTURBANCE EJECTS FROM THE THE
GULF STATES WEDNESDAY MORNING AND APPROACHES THE MID-ATLANTIC
WEDNESDAY NIGHT INTO THURSDAY. THE SYSTEM PASSES BY TO OUR SOUTH AS
SURFACE LOW PRESSURE IS SPAWNED UP OFF THE NORTH CAROLINA COAST
THURSDAY MORNING. THE MODELS HAVE BEEN FAIRLY CONSISTENT WITH THIS
IDEA. THE 12Z GFS HAS A FRONT EVEN A BIT FARTHER SOUTH THURSDAY
MORNING...KEEPING ANY PRECIPITATION OUT OF FAR SOUTHERN MARYLAND
THOUGH THERE WILL BE SOME CLOUD COVER FROM THIS. THE FLOW WILL BE LIGHT
OUT OF THE NORTH WEDNESDAY FOR COOLER AND DRIER AIR. THE NAM HAS
BACKED AWAY FROM AN EARLIER SUGGESTION OF AN EASTERLY FLOW WEDNESDAY
NIGHT AND THURSDAY. THURSDAY COULD SEE MORE SUNSHINE WITH A LITTLE
MILDER TEMPERATURES.
UPPER LOW PRESSURE OVER THE WESTERN STATES SPLITS AS A NORTHERN
BRANCH SYSTEM SWEEPS INTO THE PLAIN STATES SATURDAY MORNING. THIS
SYSTEM MAY PROGRESS INTO THE NORTHEAST STATES BY SUNDAY. FRIDAY
LOOKS DRY AND MILD WITH A LIGHT FLOW ALOFT AND PLENTY OF SUNSHINE.
CLOUDS MAY INCREASE SATURDAY AS THE WAVE APPROACHES. THE GFS SPREADS
SHOWERS INTO THE WESTERN MOUNTAINS BY AFTERNOON. GFS HAS THE SURFACE
LOW OVER OHIO SUNDAY MORNING WHILE THE EC HAS IT A BIT FARTHER
NORTH. THE EC DEVELOPS A 991MB LOW RIGHT OVER CENTRAL VA SUNDAY
NIGHT AND LIFTS IT UP THE COAST WHILE THE GFS BOMBS IT OUT WELL
OFFSHORE. THE DIFFERENCE IS A MUCH MORE AMPLIFIED JET BETWEEN THE
RIDGE OVER THE ATLANTIC AND THE WAVE. IN EITHER EVENT WE HAVE
INTRODUCED SHOWERS ACROSS THE AREA SATURDAY NIGHT AND CONTINUED
THEM INTI MONDAY FOR THE TIME BEING.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
CIGS/VSBY IN IFR-MVFR CATEGORY AHEAD OF FROPA...THEN A RAPID INCREASE TO
VFR CONDITIONS LATE TONIGHT THROUGH TUE ALONG WITH A GUSTY NW
WIND.
VFR CONDITIONS ARE LIKELY TO PERSIST AS SURFACE HIGH PRESSURE BUILDS
IN TUESDAY NIGHT INTO FRIDAY. A MID LEVEL OVC WILL MOVE OVERHEAD
WEDNESDAY AS A WAVE MOVES BY TO THE SOUTH. BREEZY NORTH WINDS TO 15
KTS ARE POSSIBLE WEDNESDAY...SHIFTING TO THE NE WEDNESDAY NIGHT. A
SOUTHWEST FLOW ALOFT WILL INCREASE FRIDAY AS A WEATHER SYSTEM
APPROACHES FROM THE OHIO VALLEY.
&&
.MARINE...
19Z OBS SHOWING FEW SCA GUSTS ON MAIN CHANNEL OF CHESSIE WITH WAA
PATTERN MAKING THE GUSTS DIFFICULT TO GET DOWN TO THE COLD WATER
SURFACE. WINDS WILL PICKUP TO SCA ACROSS ALL WATERS BEHIND FRONT
AND CONT SOLID SCA EARLY TUE BEFORE DIMINSHING TUE AFT.
SURFACE HIGH PRESSURE BUILDS OVER THE WATERS IN TUESDAY NIGHT INTO
FRIDAY. BREEZY NORTH WINDS MAY APPROACH SCA CRITERIA WEDNESDAY AS A
WEATHER DISTURBANCE PASSES BY TO THE SOUTH. LIGHT WINDS AND FAIR
WEATHER ARE ANTICIPATED THURSDAY AND FRIDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TUESDAY FOR ANZ530-531-538-
539.
SMALL CRAFT ADVISORY UNTIL 5 PM EST TUESDAY FOR ANZ532>534-537-
540>543.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO NOON EST
TUESDAY FOR ANZ535-536.
&&
$$
SYNOPSIS...LEE
NEAR TERM...LEE
SHORT TERM...LEE
LONG TERM...SDG
AVIATION...SDG/LEE
MARINE...SDG/LEE
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
921 AM EST MON DEC 10 2012
.SYNOPSIS...
A WARM FRONT LIFTS VERY SLOWLY NORTH THROUGH THE MID ATLANTIC THIS
MORNING. A COLD FRONT APPROACHES FROM THE WEST THROUGH THIS
EVENING...BEFORE PUSHING ACROSS THE AREA LATE TONIGHT INTO EARLY
TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP ALONG THE FRONT
TUESDAY NIGHT AND TRACKS OFF THE COAST WEDNESDAY. HIGH PRESSURE
BUILDS ACROSS THE REGION FOR THE LATTER HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST WX ANALYSIS SHOWS LOW PRESSURE OVER EASTERN GREAT LAKES
WITH WEAK QUASI-STATIONARY FRONT STILL DRAPED OVER NORTHERN
PIEDMONT. VISIBILITIES HAVE BEGUN TO IMPROVE AS EXPECTED
THROUGHOUT THE REGION.
LATEST SUBJECTIVE UPPER AIR ANALYSIS SHOWS POSITIVELY TILTED UPPER
TROUGH AXIS EXTENDING FROM THE UPPER MID WEST BACK INTO THE
CENTRAL HIGH PLAINS. BROAD, MOIST SW FLOW AHEAD OF THIS FEATURE
FROM THE SOUTHEASTERN CONUS UP INTO THE MID-ATLANTIC REGION. SOME
SHRAS NOTED ON REGIONAL RADAR MOSAIC IN ASSOCIATION WITH WEAK
SHORTWAVE TROUGH PUSHING ACROSS THE CAROLINA COASTAL PLAIN. MODELS
SEEM TO BE HAVING TROUBLE WITH THIS FEATURE, SO HAVE USED A BLEND
OF RUC AND SREF IN QUICKLY SCOOTING THIS WAVE OFFSHORE BY MID TO
LATE MORNING, WITH A FEW SHOWERS PUSHING INTO FAR EASTERN ZONES.
QPF LOOKING RATHER LIGHT...ON THE ORDER OF A FEW HUNDREDTHS TO A
TENTH OF AN INCH.
NORTHERN STREAM TROUGH LIFTS NORTH OF THE GREAT LAKES TODAY, AS
NEXT SOUTHERN PLAINS DAMPENS AS IT LIFTS FROM SOUTHERN PLAINS
TOWARDS THE OHIO VALLEY BY TONIGHT. AS THIS HAPPENS, SFC LOW OVER
THE EASTERN GRT LAKES WILL LIFT INTO QUEBEC WITH ATTENDANT SFC
COLD FRONT SWEEPING EASTWARD BY TONIGHT. AS IS USUALLY THE CASE,
MODELS APPEAR TOO AGGRESSIVE THIS MORNING IN PUSHING STALLED
FRONTAL BOUNDARY NORTH THIS MORNING, AND TRYING TO CLEAR OUT LOW
CLOUDS. WILL CONTINUE WITH PARTLY TO MOSTLY CLOUDY WORDING THROUGH
THE DAY, W/ HIGHS IN THE MID 60S TO LOW 70S, WITH A FEW MID 70S
POSSIBLE GIVEN PRESENT TEMPERATURES ALREADY IN THE L-M 60S ACROSS
SE VA/NE NC.
FORCING FOR ASCENT APPEARS RATHER ANEMIC THROUGH MUCH OF THE DAY
AND DESPITE MILD TEMPS AND LLVL MOISTURE, FORECAST SOUNDINGS
INDICATE DESTABILIZATION WILL BE DIFFICULT GIVEN SIGNIFICANT CLOUD
COVER THROUGH MOST OF THE DAY. THUS, EXPECT MOST OF THE DAY TO BE
DRY OVER THE AREA. DO INCREASE RAIN CHANCES OVER THE FAR NW BY THE
LATE AFTERNOON AS FRONT APPROACHES FROM THE WEST.
AS MENTIONED EARLIER, THE UPPER TROUGH WILL DAMPEN/WEAKEN AS IT
PUSHES ACROSS THE OHIO VALLEY INTO THE NORTHERN MID ATLANTIC
TONIGHT INTO EARLY TUESDAY, DRAGGING THE COLD FRONT ACROSS THE
CWA TONIGHT AND OFF THE COAST EARLY TUESDAY MORNING. HIGH END CHC
TO LIKELY POPS (50-60%) WILL BE MAINTAINED WITH THE FRONTAL
PASSAGE TONIGHT ACROSS THE WEST, ALTHOUGH QPF WILL BE RATHER
LIGHT. LOWS TONIGHT SHOULD BE IN THE MID 40S NW...TO MID 50S
SE...FOLLOWED BY HIGHS TUESDAY IN THE LOW 50S N AND W...TO LOW 60S
SE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
THE FRONT EVENTUALLY WILL BECOME STALLED SOUTH OF THE AREA BY
TUESDAY NIGHT AND WEDNESDAY. IN THE INTERIM, EXPECT CLEARING ON
TUESDAY WITH HIGH PRESSURE BUILDING IN FROM THE WEST. LINGERING
SHRAS ACROSS SE COASTAL PLAIN QUICKLY YIELD TO SEASONABLY COOL AND
DRY CONDITIONS BY AFTN. WINDS TURN AROUND TO THE NORTH AND REMAIN
RATHER LIGHT THROUGH THE DAY. HIGHS GENERALLY IN THE 50S UNDER A
PARTLY TO MOSTLY CLOUDY SKY
MODELS APPEAR IN A BIT MORE AGREEMENT WITH DEPICTING A WAVE OF
LOW PRESSURE THAT DEVELOPS ALONG THE STALLED BOUNDARY TO THE SOUTH
ON TUESDAY, BUT STILL SOME DISAGREEMENT WRT ORIENTATION OF PCPN
TUESDAY NIGHT AND WEDNESDAY. ECMWF KEEPS MUCH OF THIS ACTIVITY
WELL TO OUR SOUTH, WITH THE NAM BRINGING LIGHT PCPN AS FAR NORTH
AS RIC. GFS/SREF STILL APPEARS TO BE ACCEPTABLE MIDDLE GROUND
SOLUTION, BRINGING SOME LIGHT PCPN ACROS SOUTHERN TIER OF COUNTIES
LATE TUE-WED. CONTINUED INHERITED TREND WITH INCREASING CLOUDS
TUESDAY NIGHT/WED ACROSS THE SOUTHEAST, WITH RAIN CHCS FOR LATE
TUE INTO WED STILL LOOKING GOOD (LOW QPF ONCE AGAIN). LOW
TEMPERATURES TUESDAY NIGHT ARE FORECAST TO BE IN THE MID 30S
N...TO LOW TO MID 40S SE. HIGHS WEDNESDAY IN THE MID 40S TO LOW
50S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
FNTL BNDRY/ASSOCD MSTR
SLO TO EXIT THE CST WED NGT. AFT THAT...HI PRES BUILDS INTO THE
MDATLC RGN FM THU THROUGH FRI...THEN WEAKENS INTO THE NEXT WKND.
UNCERTAINTY EXISTS NEXT SAT/SUN WRT PTNTL BKDR CDFNT ENTERING THE
RGN FM THE N...AND PSBL ARRIVAL OF LO PRES FM THE W.
LO POPS WED NGT...GIVING WAY TO DRY WX (AND POPS AOB 14%) THU INTO
SAT. WILL BRING A GRADUAL INCRS IN CLDNS AND POPS FM SAT THROUGH
SUN. TEMPS WILL AVG OUT NR SEASONABLE LVLS THROUGH THE PD.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
A WARM FRONT DRAPED ACROSS CTRL VA IS ALLOWING AREAS OF FOG AND
VERY LOW CIGS (200-500 FT AGL) TO PLAGUE THE REGION THIS MORNING.
TAF SITES KRIC AND KPHF WILL BE THE MOST SUSCEPTIBLE TO THESE
CONDITIONS THRU AT LEAST 10/1300Z. MEANWHILE...A DISTURBANCE ALONG
THE NC COAST WILL MOVE NNE AND SPREAD LIGHT RAIN SHOWERS OVER
NE NC...FAR SE VA...AND THE MD/VA LOWER ERN SHORE THIS MORNING
THRU EARLY AFTN BEFORE PUSHING NE AND AWAY FROM THE MID ATLANTIC
COAST. SOME CLEARING...OR AT LEAST HIGHER CIGS AND VIS...ARE
ANTICIPATED DURING THE AFTN AS THE REGION SITS WITHIN THE WARM
SECTOR AHEAD OF AN APPROACHING COLD FRONT TO THE WEST. EXPECT
BREEZY SOUTH WINDS TO DEVELOP BY EARLY AFTN AND PERSIST INTO THIS
EVENING...BECOMING GUSTY AT TIMES (15-20KT). THE COLD FRONT IS
FORECAST TO CROSS THE AREA TONIGHT INTO TUESDAY MORNING. THE BEST
RAINFALL WILL OCCUR RIGHT ALONG THE FRONT LATE THIS EVENING...
GRADUALLY DIMINISHING IN INTENSITY OVERNIGHT AS ITS ENERGY GETS
SHEARED APART WHILE IT TRACKS TWD THE COAST. CIGS ARE ESTIMATED TO
BE 2-3KFT AND VIS SHOULD BE NO LOWER THAN 3-4SM UNDER HEAVIER
AREAS OF RAINFALL.
LINGERING PRECIP IS POSSIBLE ALONG THE IMMEDIATE MID ATLANTIC
COAST TUESDAY MORNING WITH CONDITIONS IMPROVING THROUGHOUT THE
DAY. A SECONDARY LOW PRESSURE SYSTEM WILL TRACK UP THE COAST AND
BRING STEADY STRATIFORM PRECIP MAINLY TO AREAS SE OF A LINE FROM
KSBY-KRIC-KDAN LATE TUESDAY NIGHT INTO WEDNESDAY. THIS SYSTEM HAS
THE POTENTIAL TO RAPIDLY DETERIORATE CIGS/VIS AT ALL TAF SITES
DURING THIS TIME.
&&
.MARINE...
A WARM FRONT WILL LIFT NORTH AS WARM FRONT AS A COLD FRONT
APPROACHES FROM THE WEST TODAY. S WINDS WILL GRADUALLY INCREASE AND
VEER TO THE SSW-SW THROUGH THE MORNING AND BECOME BREEZY/GUSTY BY
EARLY AFTN. SUSTAINED WINDS WILL AVERAGE 10-15 KT WITH GUSTS OF
15-20 KT OVER ALL AREA WATERS. THEREFORE...SCA FLAGS HAVE BEEN
RAISED FOR ERN VA RIVERS AND CURRITUCK SOUND BEGINNING AT NOON AND
ENDING AROUND MIDNIGHT. NRN COASTAL WATERS WILL SEE THEIR INCREASE
IN WIND SPEEDS LATE AFTN/EARLY EVENING WITH SUSTAINED 20 KT AND
GUSTS OF 25-30 KT AT TIMES. OVERALL...MAIN SUITE OF SCA HEADLINES
ISSUED ON SUNDAY REMAIN INTACT REGARDING TIMING...WIND
SPEEDS/GUSTS...AND WAVES/SEAS (3-4 FT BAY/4-5 FT OCEAN).
THE COLD FRONT CROSSES THE WATERS MONDAY NIGHT...FOLLOWED BY LLVL
SURGE AND MODERATE PROBABILITIES FOR SCA SPEEDS AS WINDS BECOME NNW
AFTER MIDNIGHT. CONDITIONS WILL BE SLOW TO IMPROVE DURING TUESDAY AS
THE FRONT STALLS JUST OFF THE COASTAL CAROLINAS AND WEAK HIGH
PRESSURE BUILDS IN THE NRN MID ATLANTIC REGION. EXPECT A PERIOD OF
NNE WINDS FROM TUE NIGHT INTO WED NIGHT AS A SECONDARY SFC LOW
PRESSURE DEVELOPS/TRACKS NE ALONG THE STALLED FRONT. TIGHT
TEMPERATURE DIFFERENCES WILL LIKELY RESULT IN A TIGHT PRESSURE
GRADIENT AND SPEEDS/WAVES/SEAS ARE ANTICIPATED TO INCREASE INTO SCA
THRESHOLDS...ESPECIALLY THE SRN PORTION OF THE BAY/OCEAN WATERS
TUESDAY NIGHT INTO WEDNESDAY. HIGH PRESSURE IS POISED TO RETURN LATE
IN THE WEEK WHICH WILL GREATLY IMPROVE MARINE WX CONDITIONS HEADING
INTO THE WEEKEND.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 1 AM EST
TUESDAY FOR ANZ633-635>637.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 AM EST
TUESDAY FOR ANZ632-634.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 6 AM EST
TUESDAY FOR ANZ630-631-638.
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO NOON EST
TUESDAY FOR ANZ650-652-654.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAS/MAM
SHORT TERM...AJZ/MAM
LONG TERM...ALB
AVIATION...BMD
MARINE...ALB
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
656 AM EST MON DEC 10 2012
.SYNOPSIS...
A WARM FRONT LIFTS VERY SLOWLY NORTH THROUGH THE MID ATLANTIC THIS
MORNING. A COLD FRONT APPROACHES FROM THE WEST THROUGH THIS
EVENING...BEFORE PUSHING ACROSS THE AREA LATE TONIGHT INTO EARLY
TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP ALONG THE FRONT
TUESDAY NIGHT AND TRACKS OFF THE COAST WEDNESDAY. HIGH PRESSURE
BUILDS ACROSS THE REGION FOR THE LATTER HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST WX ANALYSIS SHOWS LOW PRESSURE OVER EASTERN GREAT LAKES
THIS MORNING, WITH WEAK QUASI-STATIONARY FRONT STILL DRAPED OVER
INTERIOR EASTERN SHORE...ACROSS INTO SOUTH CENTRAL VA AND BACK
INTO WESTERN PA/E OHIO. VISIBILITIES HAVE BEGUN TO IMPROVE AS
EXPECTED ACROSS INTERIOR NC AND ALONG I-85 CORRIDOR. WILL BE
DROPPING DENSE FOG ADVISORY WITH MORNING PACKAGE ISSUANCE OVER
SOUTHERN PORTIONS OF THE AREA. DO EXPECT VISIBILITIES TO CONTINUE
TO IMPROVE W/CONTINUED WAA, BUT FOR NOW WILL HOLD ONTO MOST
LOCATIONS ALONG AND NORTH OF A FARMVILLE- RICHMOND- WALLOPS LINE.
LATEST SUBJECTIVE UPPER AIR ANALYSIS SHOWS POSITIVELY TILTED UPPER
TROUGH AXIS EXTENDING FROM THE UPPER MID WEST BACK INTO THE
CENTRAL HIGH PLAINS. BROAD, MOIST SW FLOW AHEAD OF THIS FEATURE
FROM THE SOUTHEASTERN CONUS UP INTO THE MID-ATLANTIC REGION. SOME
SHRAS NOTED ON REGIONAL RADAR MOSAIC IN ASSOCIATION WITH WEAK
SHORTWAVE TROUGH PUSHING ACROSS THE CAROLINA COASTAL PLAIN. MODELS
SEEM TO BE HAVING TROUBLE WITH THIS FEATURE, SO HAVE USED A BLEND
OF RUC AND SREF IN QUICKLY SCOOTING THIS WAVE OFFSHORE BY MID TO
LATE MORNING, WITH A FEW SHOWERS PUSHING INTO FAR EASTERN ZONES.
QPF LOOKING RATHER LIGHT...ON THE ORDER OF A FEW HUNDREDTHS TO A
TENTH OF AN INCH.
NORTHERN STREAM TROUGH LIFTS NORTH OF THE GREAT LAKES TODAY, AS
NEXT SOUTHERN PLAINS DAMPENS AS IT LIFTS FROM SOUTHERN PLAINS
TOWARDS THE OHIO VALLEY BY TONIGHT. AS THIS HAPPENS, SFC LOW OVER
THE EASTERN GRT LAKES WILL LIFT INTO QUEBEC WITH ATTENDANT SFC
COLD FRONT SWEEPING EASTWARD BY TONIGHT. AS IS USUALLY THE CASE,
MODELS APPEAR TOO AGGRESSIVE THIS MORNING IN PUSHING STALLED
FRONTAL BOUNDARY NORTH THIS MORNING, AND TRYING TO CLEAR OUT LOW
CLOUDS. WILL CONTINUE WITH PARTLY TO MOSTLY CLOUDY WORDING THROUGH
THE DAY, W/ HIGHS IN THE MID 60S TO LOW 70S, WITH A FEW MID 70S
POSSIBLE GIVEN PRESENT TEMPERATURES ALREADY IN THE L-M 60S ACROSS
SE VA/NE NC.
FORCING FOR ASCENT APPEARS RATHER ANEMIC THROUGH MUCH OF THE DAY
AND DESPITE MILD TEMPS AND LLVL MOISTURE, FORECAST SOUNDINGS
INDICATE DESTABILIZATION WILL BE DIFFICULT GIVEN SIGNIFICANT CLOUD
COVER THROUGH MOST OF THE DAY. THUS, EXPECT MOST OF THE DAY TO BE
DRY OVER THE AREA. DO INCREASE RAIN CHANCES OVER THE FAR NW BY THE
LATE AFTERNOON AS FRONT APPROACHES FROM THE WEST.
AS MENTIONED EARLIER, THE UPPER TROUGH WILL DAMPEN/WEAKEN AS IT
PUSHES ACROSS THE OHIO VALLEY INTO THE NORTHERN MID ATLANTIC
TONIGHT INTO EARLY TUESDAY, DRAGGING THE COLD FRONT ACROSS THE
CWA TONIGHT AND OFF THE COAST EARLY TUESDAY MORNING. HIGH END CHC
TO LIKELY POPS (50-60%) WILL BE MAINTAINED WITH THE FRONTAL
PASSAGE TONIGHT ACROSS THE WEST, ALTHOUGH QPF WILL BE RATHER
LIGHT. LOWS TONIGHT SHOULD BE IN THE MID 40S NW...TO MID 50S
SE...FOLLOWED BY HIGHS TUESDAY IN THE LOW 50S N AND W...TO LOW 60S
SE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
THE FRONT EVENTUALLY WILL BECOME STALLED SOUTH OF THE AREA BY
TUESDAY NIGHT AND WEDNESDAY. IN THE INTERIM, EXPECT CLEARING ON
TUESDAY WITH HIGH PRESSURE BUILDING IN FROM THE WEST. LINGERING
SHRAS ACROSS SE COASTAL PLAIN QUICKLY YIELD TO SEASONABLY COOL AND
DRY CONDITIONS BY AFTN. WINDS TURN AROUND TO THE NORTH AND REMAIN
RATHER LIGHT THROUGH THE DAY. HIGHS GENERALLY IN THE 50S UNDER A
PARTLY TO MOSTLY CLOUDY SKY
MODELS APPEAR IN A BIT MORE AGREEMENT WITH DEPICTING A WAVE OF
LOW PRESSURE THAT DEVELOPS ALONG THE STALLED BOUNDARY TO THE SOUTH
ON TUESDAY, BUT STILL SOME DISAGREEMENT WRT ORIENTATION OF PCPN
TUESDAY NIGHT AND WEDNESDAY. ECMWF KEEPS MUCH OF THIS ACTIVITY
WELL TO OUR SOUTH, WITH THE NAM BRINGING LIGHT PCPN AS FAR NORTH
AS RIC. GFS/SREF STILL APPEARS TO BE ACCEPTABLE MIDDLE GROUND
SOLUTION, BRINGING SOME LIGHT PCPN ACROS SOUTHERN TIER OF COUNTIES
LATE TUE-WED. CONTINUED INHERITED TREND WITH INCREASING CLOUDS
TUESDAY NIGHT/WED ACROSS THE SOUTHEAST, WITH RAIN CHCS FOR LATE
TUE INTO WED STILL LOOKING GOOD (LOW QPF ONCE AGAIN). LOW
TEMPERATURES TUESDAY NIGHT ARE FORECAST TO BE IN THE MID 30S
N...TO LOW TO MID 40S SE. HIGHS WEDNESDAY IN THE MID 40S TO LOW
50S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
FNTL BNDRY/ASSOCD MSTR
SLO TO EXIT THE CST WED NGT. AFT THAT...HI PRES BUILDS INTO THE
MDATLC RGN FM THU THROUGH FRI...THEN WEAKENS INTO THE NEXT WKND.
UNCERTAINTY EXISTS NEXT SAT/SUN WRT PTNTL BKDR CDFNT ENTERING THE
RGN FM THE N...AND PSBL ARRIVAL OF LO PRES FM THE W.
LO POPS WED NGT...GIVING WAY TO DRY WX (AND POPS AOB 14%) THU INTO
SAT. WILL BRING A GRADUAL INCRS IN CLDNS AND POPS FM SAT THROUGH
SUN. TEMPS WILL AVG OUT NR SEASONABLE LVLS THROUGH THE PD.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A WARM FRONT DRAPED ACROSS CTRL VA IS ALLOWING AREAS OF FOG AND
VERY LOW CIGS (200-500 FT AGL) TO PLAGUE THE REGION THIS MORNING.
TAF SITES KRIC AND KPHF WILL BE THE MOST SUSCEPTIBLE TO THESE
CONDITIONS THRU AT LEAST 10/1300Z. MEANWHILE...A DISTURBANCE ALONG
THE NC COAST WILL MOVE NNE AND SPREAD LIGHT RAIN SHOWERS OVER
NE NC...FAR SE VA...AND THE MD/VA LOWER ERN SHORE THIS MORNING
THRU EARLY AFTN BEFORE PUSHING NE AND AWAY FROM THE MID ATLANTIC
COAST. SOME CLEARING...OR AT LEAST HIGHER CIGS AND VIS...ARE
ANTICIPATED DURING THE AFTN AS THE REGION SITS WITHIN THE WARM
SECTOR AHEAD OF AN APPROACHING COLD FRONT TO THE WEST. EXPECT
BREEZY SOUTH WINDS TO DEVELOP BY EARLY AFTN AND PERSIST INTO THIS
EVENING...BECOMING GUSTY AT TIMES (15-20KT). THE COLD FRONT IS
FORECAST TO CROSS THE AREA TONIGHT INTO TUESDAY MORNING. THE BEST
RAINFALL WILL OCCUR RIGHT ALONG THE FRONT LATE THIS EVENING...
GRADUALLY DIMINISHING IN INTENSITY OVERNIGHT AS ITS ENERGY GETS
SHEARED APART WHILE IT TRACKS TWD THE COAST. CIGS ARE ESTIMATED TO
BE 2-3KFT AND VIS SHOULD BE NO LOWER THAN 3-4SM UNDER HEAVIER
AREAS OF RAINFALL.
LINGERING PRECIP IS POSSIBLE ALONG THE IMMEDIATE MID ATLANTIC
COAST TUESDAY MORNING WITH CONDITIONS IMPROVING THROUGHOUT THE
DAY. A SECONDARY LOW PRESSURE SYSTEM WILL TRACK UP THE COAST AND
BRING STEADY STRATIFORM PRECIP MAINLY TO AREAS SE OF A LINE FROM
KSBY-KRIC-KDAN LATE TUESDAY NIGHT INTO WEDNESDAY. THIS SYSTEM HAS
THE POTENTIAL TO RAPIDLY DETERIORATE CIGS/VIS AT ALL TAF SITES
DURING THIS TIME.
&&
.MARINE...
A WARM FRONT WILL LIFT NORTH AS WARM FRONT AS A COLD FRONT
APPROACHES FROM THE WEST TODAY. S WINDS WILL GRADUALLY INCREASE AND
VEER TO THE SSW-SW THROUGH THE MORNING AND BECOME BREEZY/GUSTY BY
EARLY AFTN. SUSTAINED WINDS WILL AVERAGE 10-15 KT WITH GUSTS OF
15-20 KT OVER ALL AREA WATERS. THEREFORE...SCA FLAGS HAVE BEEN
RAISED FOR ERN VA RIVERS AND CURRITUCK SOUND BEGINNING AT NOON AND
ENDING AROUND MIDNIGHT. NRN COASTAL WATERS WILL SEE THEIR INCREASE
IN WIND SPEEDS LATE AFTN/EARLY EVENING WITH SUSTAINED 20 KT AND
GUSTS OF 25-30 KT AT TIMES. OVERALL...MAIN SUITE OF SCA HEADLINES
ISSUED ON SUNDAY REMAIN INTACT REGARDING TIMING...WIND
SPEEDS/GUSTS...AND WAVES/SEAS (3-4 FT BAY/4-5 FT OCEAN).
THE COLD FRONT CROSSES THE WATERS MONDAY NIGHT...FOLLOWED BY LLVL
SURGE AND MODERATE PROBABILITIES FOR SCA SPEEDS AS WINDS BECOME NNW
AFTER MIDNIGHT. CONDITIONS WILL BE SLOW TO IMPROVE DURING TUESDAY AS
THE FRONT STALLS JUST OFF THE COASTAL CAROLINAS AND WEAK HIGH
PRESSURE BUILDS IN THE NRN MID ATLANTIC REGION. EXPECT A PERIOD OF
NNE WINDS FROM TUE NIGHT INTO WED NIGHT AS A SECONDARY SFC LOW
PRESSURE DEVELOPS/TRACKS NE ALONG THE STALLED FRONT. TIGHT
TEMPERATURE DIFFERENCES WILL LIKELY RESULT IN A TIGHT PRESSURE
GRADIENT AND SPEEDS/WAVES/SEAS ARE ANTICIPATED TO INCREASE INTO SCA
THRESHOLDS...ESPECIALLY THE SRN PORTION OF THE BAY/OCEAN WATERS
TUESDAY NIGHT INTO WEDNESDAY. HIGH PRESSURE IS POISED TO RETURN LATE
IN THE WEEK WHICH WILL GREATLY IMPROVE MARINE WX CONDITIONS HEADING
INTO THE WEEKEND.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR VAZ048-049-
060>064-067>074-083.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO NOON EST
TUESDAY FOR ANZ650-652-654.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 1 AM EST
TUESDAY FOR ANZ633-635>637.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 AM EST
TUESDAY FOR ANZ632-634.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 6 AM EST
TUESDAY FOR ANZ630-631-638.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...AJZ/MAM
LONG TERM...ALB
AVIATION...BMD
MARINE...ALB
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
432 AM EST MON DEC 10 2012
.SYNOPSIS...
A WARM FRONT LIFTS VERY SLOWLY NORTH THROUGH THE MID ATLANTIC THIS
MORNING. A COLD FRONT APPROACHES FROM THE WEST THROUGH THIS
EVENING...BEFORE PUSHING ACROSS THE AREA LATE TONIGHT INTO EARLY
TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP ALONG THE FRONT
TUESDAY NIGHT AND TRACKS OFF THE COAST WEDNESDAY. HIGH PRESSURE
BUILDS ACROSS THE REGION FOR THE LATTER HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST WX ANALYSIS SHOWS LOW PRESSURE OVER EASTERN GREAT LAKES
THIS MORNING, WITH WEAK QUASI-STATIONARY FRONT STILL DRAPED OVER
INTERIOR EASTERN SHORE...ACROSS INTO SOUTH CENTRAL VA AND BACK
INTO WESTERN PA/E OHIO. VISIBILITIES HAVE BEGUN TO IMPROVE AS
EXPECTED ACROSS INTERIOR NC AND ALONG I-85 CORRIDOR. WILL BE
DROPPING DENSE FOG ADVISORY WITH MORNING PACKAGE ISSUANCE OVER
SOUTHERN PORTIONS OF THE AREA. DO EXPECT VISIBILITIES TO CONTINUE
TO IMPROVE W/CONTINUED WAA, BUT FOR NOW WILL HOLD ONTO MOST
LOCATIONS ALONG AND NORTH OF A FARMVILLE- RICHMOND- WALLOPS LINE.
LATEST SUBJECTIVE UPPER AIR ANALYSIS SHOWS POSITIVELY TILTED UPPER
TROUGH AXIS EXTENDING FROM THE UPPER MID WEST BACK INTO THE
CENTRAL HIGH PLAINS. BROAD, MOIST SW FLOW AHEAD OF THIS FEATURE
FROM THE SOUTHEASTERN CONUS UP INTO THE MID-ATLANTIC REGION. SOME
SHRAS NOTED ON REGIONAL RADAR MOSAIC IN ASSOCIATION WITH WEAK
SHORTWAVE TROUGH PUSHING ACROSS THE CAROLINA COASTAL PLAIN. MODELS
SEEM TO BE HAVING TROUBLE WITH THIS FEATURE, SO HAVE USED A BLEND
OF RUC AND SREF IN QUICKLY SCOOTING THIS WAVE OFFSHORE BY MID TO
LATE MORNING, WITH A FEW SHOWERS PUSHING INTO FAR EASTERN ZONES.
QPF LOOKING RATHER LIGHT...ON THE ORDER OF A FEW HUNDREDTHS TO A
TENTH OF AN INCH.
NORTHERN STREAM TROUGH LIFTS NORTH OF THE GREAT LAKES TODAY, AS
NEXT SOUTHERN PLAINS DAMPENS AS IT LIFTS FROM SOUTHERN PLAINS
TOWARDS THE OHIO VALLEY BY TONIGHT. AS THIS HAPPENS, SFC LOW OVER
THE EASTERN GRT LAKES WILL LIFT INTO QUEBEC WITH ATTENDANT SFC
COLD FRONT SWEEPING EASTWARD BY TONIGHT. AS IS USUALLY THE CASE,
MODELS APPEAR TOO AGGRESSIVE THIS MORNING IN PUSHING STALLED
FRONTAL BOUNDARY NORTH THIS MORNING, AND TRYING TO CLEAR OUT LOW
CLOUDS. WILL CONTINUE WITH PARTLY TO MOSTLY CLOUDY WORDING THROUGH
THE DAY, W/ HIGHS IN THE MID 60S TO LOW 70S, WITH A FEW MID 70S
POSSIBLE GIVEN PRESENT TEMPERATURES ALREADY IN THE L-M 60S ACROSS
SE VA/NE NC.
FORCING FOR ASCENT APPEARS RATHER ANEMIC THROUGH MUCH OF THE DAY
AND DESPITE MILD TEMPS AND LLVL MOISTURE, FORECAST SOUNDINGS
INDICATE DESTABILIZATION WILL BE DIFFICULT GIVEN SIGNIFICANT CLOUD
COVER THROUGH MOST OF THE DAY. THUS, EXPECT MOST OF THE DAY TO BE
DRY OVER THE AREA. DO INCREASE RAIN CHANCES OVER THE FAR NW BY THE
LATE AFTERNOON AS FRONT APPROACHES FROM THE WEST.
AS MENTIONED EARLIER, THE UPPER TROUGH WILL DAMPEN/WEAKEN AS IT
PUSHES ACROSS THE OHIO VALLEY INTO THE NORTHERN MID ATLANTIC
TONIGHT INTO EARLY TUESDAY, DRAGGING THE COLD FRONT ACROSS THE
CWA TONIGHT AND OFF THE COAST EARLY TUESDAY MORNING. HIGH END CHC
TO LIKELY POPS (50-60%) WILL BE MAINTAINED WITH THE FRONTAL
PASSAGE TONIGHT ACROSS THE WEST, ALTHOUGH QPF WILL BE RATHER
LIGHT. LOWS TONIGHT SHOULD BE IN THE MID 40S NW...TO MID 50S
SE...FOLLOWED BY HIGHS TUESDAY IN THE LOW 50S N AND W...TO LOW 60S
SE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
THE FRONT EVENTUALLY WILL BECOME STALLED SOUTH OF THE AREA BY
TUESDAY NIGHT AND WEDNESDAY. IN THE INTERIM, EXPECT CLEARING ON
TUESDAY WITH HIGH PRESSURE BUILDING IN FROM THE WEST. LINGERING
SHRAS ACROSS SE COASTAL PLAIN QUICKLY YIELD TO SEASONABLY COOL AND
DRY CONDITIONS BY AFTN. WINDS TURN AROUND TO THE NORTH AND REMAIN
RATHER LIGHT THROUGH THE DAY. HIGHS GENERALLY IN THE 50S UNDER A
PARTLY TO MOSTLY CLOUDY SKY
MODELS APPEAR IN A BIT MORE AGREEMENT WITH DEPICTING A WAVE OF
LOW PRESSURE THAT DEVELOPS ALONG THE STALLED BOUNDARY TO THE SOUTH
ON TUESDAY, BUT STILL SOME DISAGREEMENT WRT ORIENTATION OF PCPN
TUESDAY NIGHT AND WEDNESDAY. ECMWF KEEPS MUCH OF THIS ACTIVITY
WELL TO OUR SOUTH, WITH THE NAM BRINGING LIGHT PCPN AS FAR NORTH
AS RIC. GFS/SREF STILL APPEARS TO BE ACCEPTABLE MIDDLE GROUND
SOLUTION, BRINGING SOME LIGHT PCPN ACROS SOUTHERN TIER OF COUNTIES
LATE TUE-WED. CONTINUED INHERITED TREND WITH INCREASING CLOUDS
TUESDAY NIGHT/WED ACROSS THE SOUTHEAST, WITH RAIN CHCS FOR LATE
TUE INTO WED STILL LOOKING GOOD (LOW QPF ONCE AGAIN). LOW
TEMPERATURES TUESDAY NIGHT ARE FORECAST TO BE IN THE MID 30S
N...TO LOW TO MID 40S SE. HIGHS WEDNESDAY IN THE MID 40S TO LOW
50S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/... FNTL BNDRY/ASSOCD MSTR
SLO TO EXIT THE CST WED NGT. AFT THAT...HI PRES BUILDS INTO THE
MDATLC RGN FM THU THROUGH FRI...THEN WEAKENS INTO THE NEXT WKND.
UNCERTAINTY EXISTS NEXT SAT/SUN WRT PTNTL BKDR CDFNT ENTERING THE
RGN FM THE N...AND PSBL ARRIVAL OF LO PRES FM THE W.
LO POPS WED NGT...GIVING WAY TO DRY WX (AND POPS AOB 14%) THU INTO
SAT. WILL BRING A GRADUAL INCRS IN CLDNS AND POPS FM SAT THROUGH
SUN. TEMPS WILL AVG OUT NR SEASONABLE LVLS THROUGH THE PD.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A WARM FRONT DRAPED ACROSS CTRL VA IS ALLOWING WIDESPREAD FOG
(VIS GENERALLY LESS THAN 1/2SM) AND VERY LOW CIGS TO PLAGUE THIS
AREA EARLY THIS MORNING. TAF SITES KRIC AND KPHF...AND TO A LESSER
EXTENT KSBY...WILL BE THE MOST SUSCEPTIBLE TO THESE CONDITIONS
THRU AT LEAST 10/1200-1300Z. AS THE WARM FRONT MOVES NORTH OF THE
REGION THIS MORNING...A DISTURBANCE ALONG THE NC COAST WILL MOVE
NORTH AND SPREAD LIGHT RAIN SHOWERS OVER NE NC...FAR SE VA...AND
THE MD/VA LOWER ERN SHORE MID-MORNING THRU EARLY AFTN BEFORE
MOVING NE AND AWAY FROM THE MID ATLANTIC COAST. SOME CLEARING...OR
AT LEAST HIGHER CIGS AND VIS...ARE ANTICIPATED DURING THE AFTN AS
THE REGION SITS WITHIN THE WARM SECTOR AHEAD OF AN APPROACHING
COLD FRONT TO THE WEST. EXPECT BREEZY SOUTH WINDS TO DEVELOP BY
EARLY AFTN AND PERSIST INTO THIS EVENING...BECOMING GUSTY AT TIMES
(15-20KT). THE COLD FRONT IS FORECAST TO CROSS THE AREA TONIGHT
INTO TUESDAY MORNING. THE BEST RAINFALL WILL OCCUR RIGHT ALONG THE
FRONT LATE THIS EVENING...GRADUALLY DIMINISHING IN INTENSITY
OVERNIGHT AS ITS ENERGY GETS SHEARED APART WHILE IT TRACKS TWD THE
COAST. CIGS ARE ESTIMATED TO BE 2-3KFT AND VIS SHOULD BE NO LOWER
THAN 3-4SM UNDER HEAVIER AREAS OF RAINFALL.
LINGERING PRECIP IS POSSIBLE ALONG THE IMMEDIATE MID ATLANTIC
COAST TUESDAY MORNING WITH CONDITIONS IMPROVING THROUGHOUT THE
DAY. A SECONDARY LOW PRESSURE SYSTEM WILL TRACK UP THE COAST AND
BRING STEADY STRATIFORM PRECIP MAINLY TO AREAS SE OF A LINE FROM
KSBY-KRIC-KDAN LATE TUESDAY NIGHT INTO WEDNESDAY. THIS SYSTEM HAS
THE POTENTIAL TO RAPIDLY DETERIORATE CIGS/VIS AT ALL TAF SITES
DURING THIS TIME.
&&
.MARINE...
A WARM FRONT WILL LIFT NORTH AS WARM FRONT AS A COLD FRONT
APPROACHES FROM THE WEST TODAY. S WINDS WILL GRADUALLY INCREASE AND
VEER TO THE SSW-SW THROUGH THE MORNING AND BECOME BREEZY/GUSTY BY
EARLY AFTN. SUSTAINED WINDS WILL AVERAGE 10-15 KT WITH GUSTS OF
15-20 KT OVER ALL AREA WATERS. THEREFORE...SCA FLAGS HAVE BEEN
RAISED FOR ERN VA RIVERS AND CURRITUCK SOUND BEGINNING AT NOON AND
ENDING AROUND MIDNIGHT. NRN COASTAL WATERS WILL SEE THEIR INCREASE
IN WIND SPEEDS LATE AFTN/EARLY EVENING WITH SUSTAINED 20 KT AND
GUSTS OF 25-30 KT AT TIMES. OVERALL...MAIN SUITE OF SCA HEADLINES
ISSUED ON SUNDAY REMAIN INTACT REGARDING TIMING...WIND
SPEEDS/GUSTS...AND WAVES/SEAS (3-4 FT BAY/4-5 FT OCEAN).
THE COLD FRONT CROSSES THE WATERS MONDAY NIGHT...FOLLOWED BY LLVL
SURGE AND MODERATE PROBABILITIES FOR SCA SPEEDS AS WINDS BECOME NNW
AFTER MIDNIGHT. CONDITIONS WILL BE SLOW TO IMPROVE DURING TUESDAY AS
THE FRONT STALLS JUST OFF THE COASTAL CAROLINAS AND WEAK HIGH
PRESSURE BUILDS IN THE NRN MID ATLANTIC REGION. EXPECT A PERIOD OF
NNE WINDS FROM TUE NIGHT INTO WED NIGHT AS A SECONDARY SFC LOW
PRESSURE DEVELOPS/TRACKS NE ALONG THE STALLED FRONT. TIGHT
TEMPERATURE DIFFERENCES WILL LIKELY RESULT IN A TIGHT PRESSURE
GRADIENT AND SPEEDS/WAVES/SEAS ARE ANTICIPATED TO INCREASE INTO SCA
THRESHOLDS...ESPECIALLY THE SRN PORTION OF THE BAY/OCEAN WATERS
TUESDAY NIGHT INTO WEDNESDAY. HIGH PRESSURE IS POISED TO RETURN LATE
IN THE WEEK WHICH WILL GREATLY IMPROVE MARINE WX CONDITIONS HEADING
INTO THE WEEKEND.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR MDZ021>025.
NC...NONE.
VA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR VAZ048-049-
060>064-067>078-083-085.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO NOON EST
TUESDAY FOR ANZ650-652-654.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 1 AM EST
TUESDAY FOR ANZ633-635>637.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 AM EST
TUESDAY FOR ANZ632-634.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 6 AM EST
TUESDAY FOR ANZ630-631-638.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...AJZ/MAM
LONG TERM...ALB
AVIATION...BMD
MARINE...BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
413 AM EST MON DEC 10 2012
.SYNOPSIS...
A WARM FRONT LIFTS VERY SLOWLY NORTH THROUGH THE MID ATLANTIC THIS
MORNING. A COLD FRONT APPROACHES FROM THE WEST THROUGH THIS
EVENING...BEFORE PUSHING ACROSS THE AREA LATE TONIGHT INTO EARLY
TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP ALONG THE FRONT
TUESDAY NIGHT AND TRACKS OFF THE COAST WEDNESDAY. HIGH PRESSURE
BUILDS ACROSS THE REGION FOR THE LATTER HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST WX ANALYSIS SHOWS LOW PRESSURE OVER EASTERN GREAT LAKES
THIS MORNING, WITH WEAK QUASI-STATIONARY FRONT STILL DRAPED OVER
INTERIOR EASTERN SHORE...ACROSS INTO SOUTH CENTRAL VA AND BACK
INTO WESTERN PA/E OHIO. VISIBILITIES HAVE BEGUN TO IMPROVE AS
EXPECTED ACROSS INTERIOR NC AND ALONG I-85 CORRIDOR. WILL BE
DROPPING DENSE FOG ADVISORY WITH MORNING PACKAGE ISSUANCE OVER
SOUTHERN PORTIONS OF THE AREA. DO EXPECT VISIBILITIES TO CONTINUE
TO IMPROVE W/CONTINUED WAA, BUT FOR NOW WILL HOLD ONTO MOST
LOCATIONS ALONG AND NORTH OF A FARMVILLE- RICHMOND- WALLOPS LINE.
LATEST SUBJECTIVE UPPER AIR ANALYSIS SHOWS POSITIVELY TILTED UPPER
TROUGH AXIS EXTENDING FROM THE UPPER MID WEST BACK INTO THE
CENTRAL HIGH PLAINS. BROAD, MOIST SW FLOW AHEAD OF THIS FEATURE
FROM THE SOUTHEASTERN CONUS UP INTO THE MID-ATLANTIC REGION. SOME
SHRAS NOTED ON REGIONAL RADAR MOSAIC IN ASSOCIATION WITH WEAK
SHORTWAVE TROUGH PUSHING ACROSS THE CAROLINA COASTAL PLAIN. MODELS
SEEM TO BE HAVING TROUBLE WITH THIS FEATURE, SO HAVE USED A BLEND
OF RUC AND SREF IN QUICKLY SCOOTING THIS WAVE OFFSHORE BY MID TO
LATE MORNING, WITH A FEW SHOWERS PUSHING INTO FAR EASTERN ZONES.
QPF LOOKING RATHER LIGHT...ON THE ORDER OF A FEW HUNDREDTHS TO A
TENTH OF AN INCH.
NORTHERN STREAM TROUGH LIFTS NORTH OF THE GREAT LAKES TODAY, AS
NEXT SOUTHERN PLAINS DAMPENS AS IT LIFTS FROM SOUTHERN PLAINS
TOWARDS THE OHIO VALLEY BY TONIGHT. AS THIS HAPPENS, SFC LOW OVER
THE EASTERN GRT LAKES WILL LIFT INTO QUEBEC WITH ATTENDANT SFC
COLD FRONT SWEEPING EASTWARD BY TONIGHT. AS IS USUALLY THE CASE,
MODELS APPEAR TOO AGGRESSIVE THIS MORNING IN PUSHING STALLED
FRONTAL BOUNDARY NORTH THIS MORNING, AND TRYING TO CLEAR OUT LOW
CLOUDS. WILL CONTINUE WITH PARTLY TO MOSTLY CLOUDY WORDING THROUGH
THE DAY, W/ HIGHS IN THE MID 60S TO LOW 70S, WITH A FEW MID 70S
POSSIBLE GIVEN PRESENT TEMPERATURES ALREADY IN THE L-M 60S ACROSS
SE VA/NE NC.
FORCING FOR ASCENT APPEARS RATHER ANEMIC THROUGH MUCH OF THE DAY
AND DESPITE MILD TEMPS AND LLVL MOISTURE, FORECAST SOUNDINGS
INDICATE DESTABILIZATION WILL BE DIFFICULT GIVEN SIGNIFICANT CLOUD
COVER THROUGH MOST OF THE DAY. THUS, EXPECT MOST OF THE DAY TO BE
DRY OVER THE AREA. DO INCREASE RAIN CHANCES OVER THE FAR NW BY THE
LATE AFTERNOON AS FRONT APPROACHES FROM THE WEST.
AS MENTIONED EARLIER, THE UPPER TROUGH WILL DAMPEN/WEAKEN AS IT
PUSHES ACROSS THE OHIO VALLEY INTO THE NORTHERN MID ATLANTIC
TONIGHT INTO EARLY TUESDAY, DRAGGING THE COLD FRONT ACROSS THE
CWA TONIGHT AND OFF THE COAST EARLY TUESDAY MORNING. HIGH END CHC
TO LIKELY POPS (50-60%) WILL BE MAINTAINED WITH THE FRONTAL
PASSAGE TONIGHT ACROSS THE WEST, ALTHOUGH QPF WILL BE RATHER
LIGHT. LOWS TONIGHT SHOULD BE IN THE MID 40S NW...TO MID 50S
SE...FOLLOWED BY HIGHS TUESDAY IN THE LOW 50S N AND W...TO LOW 60S
SE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
THE FRONT EVENTUALLY WILL BECOME STALLED SOUTH OF THE AREA BY TUESDAY
NIGHT AND WEDNESDAY. IN THE INTERIM, EXPECT CLEARING ON TUESDAY
WITH HIGH PRESSURE BUILDING IN FROM THE WEST.
MODELS APPEAR IN A BIT MORE AGREEMENT WITH DEPICTING A WAVE OF
LOW PRESSURE THAT DEVELOPS ALONG THE STALLED BOUNDARY TUESDAY, BUT
STILL SOME DISAGREEMENT WRT ORIENTATION OF PCPN. GFS/SREF STILL
APPEARS TO BE ACCEPTABLE MIDDLE GROUND SOLUTION, SO WILL REMAIN
CLOSE TO THAT SOLUTION. CONTINUED INCREASING CLOUDS TREND TUESDAY
NIGHT/WED WITH RAIN CHCS ACROSS SE ZONES STILL LOOKING GOOD. LOW
TEMPERATURES TUESDAY NIGHT ARE FORECAST TO BE IN THE MID 30S
N...TO LOW TO MID 40S SE...FOLLOWED BY HIGHS WEDNESDAY IN THE MID
40S TO LOW 50S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
FNTL BNDRY/ASSOCD MSTR SLO TO EXIT THE CST WED NGT. AFT THAT...HI
PRES BUILDS INTO THE MDATLC RGN FM THU THROUGH FRI...THEN WEAKENS
INTO THE NEXT WKND. UNCERTAINTY EXISTS NEXT SAT/SUN WRT PTNTL BKDR
CDFNT ENTERING THE RGN FM THE N...AND PSBL ARRIVAL OF LO PRES FM THE
W.
LO POPS WED NGT...GIVING WAY TO DRY WX (AND POPS AOB 14%) THU INTO
SAT. WILL BRING A GRADUAL INCRS IN CLDNS AND POPS FM SAT THROUGH
SUN. TEMPS WILL AVG OUT NR SEASONABLE LVLS THROUGH THE PD.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
A WARM FRONT DRAPED ACROSS CTRL VA IS ALLOWING WIDESPREAD FOG
(VIS GENERALLY LESS THAN 1/2SM) AND VERY LOW CIGS TO PLAGUE THIS
AREA EARLY THIS MORNING. TAF SITES KRIC AND KPHF...AND TO A LESSER
EXTENT KSBY...WILL BE THE MOST SUSCEPTIBLE TO THESE CONDITIONS
THRU AT LEAST 10/1200-1300Z. AS THE WARM FRONT MOVES NORTH OF THE
REGION THIS MORNING...A DISTURBANCE ALONG THE NC COAST WILL MOVE
NORTH AND SPREAD LIGHT RAIN SHOWERS OVER NE NC...FAR SE VA...AND
THE MD/VA LOWER ERN SHORE MID-MORNING THRU EARLY AFTN BEFORE
MOVING NE AND AWAY FROM THE MID ATLANTIC COAST. SOME CLEARING...OR
AT LEAST HIGHER CIGS AND VIS...ARE ANTICIPATED DURING THE AFTN AS
THE REGION SITS WITHIN THE WARM SECTOR AHEAD OF AN APPROACHING
COLD FRONT TO THE WEST. EXPECT BREEZY SOUTH WINDS TO DEVELOP BY
EARLY AFTN AND PERSIST INTO THIS EVENING...BECOMING GUSTY AT TIMES
(15-20KT). THE COLD FRONT IS FORECAST TO CROSS THE AREA TONIGHT
INTO TUESDAY MORNING. THE BEST RAINFALL WILL OCCUR RIGHT ALONG THE
FRONT LATE THIS EVENING...GRADUALLY DIMINISHING IN INTENSITY
OVERNIGHT AS ITS ENERGY GETS SHEARED APART WHILE IT TRACKS TWD THE
COAST. CIGS ARE ESTIMATED TO BE 2-3KFT AND VIS SHOULD BE NO LOWER
THAN 3-4SM UNDER HEAVIER AREAS OF RAINFALL.
LINGERING PRECIP IS POSSIBLE ALONG THE IMMEDIATE MID ATLANTIC
COAST TUESDAY MORNING WITH CONDITIONS IMPROVING THROUGHOUT THE
DAY. A SECONDARY LOW PRESSURE SYSTEM WILL TRACK UP THE COAST AND
BRING STEADY STRATIFORM PRECIP MAINLY TO AREAS SE OF A LINE FROM
KSBY-KRIC-KDAN LATE TUESDAY NIGHT INTO WEDNESDAY. THIS SYSTEM HAS
THE POTENTIAL TO RAPIDLY DETERIORATE CIGS/VIS AT ALL TAF SITES
DURING THIS TIME.
&&
.MARINE...
FNTL BNDRY RMNS E-W ACRS THE CENTER OF THE CSTL WTRS THIS AFTN...W/
MNLY E WNDS N OF THE BNDRY...SSW S OF THE BNDRY. THE BNDRY WILL LIFT
BACK N AS WARM FRONT TNGT AS LO PRES TRACKS INTO THE LWR LAKES RGN.
WNDS BECOMING S...AND INCRSG (GRADUALLY) THROUGH THE OVRNGT...THOUGH
XPCD TO RMN JUST BLO SCA. AHD OF APPROACHING CDFNT FM THE W ON
MON...SSW WNDS AVG 10-20 KT...AND BY EVE XPCG SPEEDS ON THE BAY TO
BE AT MARGINAL SPDS FOR SCA. ALSO...SEAS ON THE OCN N OF CAPE
CHARLES XPCD TO GRADUALLY BUILD TO ABT 5 FT TWD EVE. CDFNT CROSSES
THE WTRS MON NGT...FOLLOWED BY LLVL SURGE AND MDT PROB FOR SCA SPDS
AS WNDS SWING TO NNW AFT MDNGT. CONDS TO SLOLY WANE DURG TUE AS FNT
STALLS JUST OF THE WTRS (INFO CSTL CAROLINAS) AND WK HI PRES BUILDS
IN THE NRN MDATLC RGN. PD OF NNE WNDS FM TUE NGT INTO WED NGT AS SFC
LO PRES DVLPS/TRACKS NE ALG THE STALLLED FNT. SPDS XPCD TO
INCRS...ESP SRN PORTION OF THE BAY/OCN WTRS TUE NGT INTO WED...ALG
W/ CORRESPONDING BUILDING WAVES/SEAS. BOTH 12Z/09 ECMWF/GFS AGREE
THAT HI PRES TO RETURN LT WK RESULTING IN BETTER MARINE WX CONDS
(HEADING INTO NEXT WKND).
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR MDZ021>025.
NC...NONE.
VA...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR VAZ048-049-
060>080-083>086-099-100.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO NOON EST
TUESDAY FOR ANZ650-652-654.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 10 AM EST
TUESDAY FOR ANZ632-634.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST
TUESDAY FOR ANZ630-631.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...AJZ/MAM
LONG TERM...ALB
AVIATION...BMD
MARINE...ALB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
626 PM EST TUE DEC 11 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 424 PM EST TUE DEC 11 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM NRN HUDSON BAY INTO THE CNTRL CONUS. WEAK SHORTWAVES MOVING
THROUGH THIS TROUGH HAVE SUPPORTED AREAS OF VERY LIGHT SNOW AND
FLURRIES TODAY. SOUTHERLY CONVERGENT FLOW OFF LAKE MICHIGAN
SUPPORTED A DOMINANT LAKE EFFECT BAND INTO LUCE COUNTY THIS MORNING
AND EARLY AFTERNOON WHICH DROPPED AT LEAST 7 INCHES OF SNOW NEAR
MCMILLAN. THIS BAND HAS SINCE WEAKENED AND MOVED EAST.
MAIN FCST CONCERN TONIGHT IS POSSIBILITY OF MODERATE LAKE EFFECT
SNOW SHOWERS OVER THE NW CWA.
TONIGHT...THE NW ONTARIO TROUGH WILL MOVE EAST AND DRAG A COLD
FRONT INTO WRN LAKE SUPERIOR. THE COLDER AIR ALONG WITH WINDS
VEERING WRLY WILL PROVIDE FAVORABLE CONDITIONS FOR LES INTO THE
KEWEENAW. WITH 850 MB TEMPS DROPPING TO AROUND -15C...INVERSION
HEIGHTS AOA 7K FT...AND LOW LEVEL CONVERGENCE STRENGTHENING DOWNWIND
FROM THE APOSTLE ISLANDS...A MODERATE TO POSSIBLE HEAVY LES BAND IS
EXPECTED TO DEVELOP. SNOWFALL AMOUNTS OF AT LEAST 2 TO 5 INCHES ARE
POSSIBLE...ESPECIALLY IN THE HIGHER TERRAIN FROM TWIN LAKES TO
CALUMET. SINCE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT A HEAVIER
BAND WILL SET UP OVER THIS AREA...HAVE ELECTED TO GO WITH AN
ADVISORY FOR NORTHERN HOUGHTON COUNTY. THERE IS STILL TOO MUCH
UNCERTAINTY TO INCLUDE KEWEENAW OR ONTONAGON IN AN ADVISORY AT THIS
TIME AS IT LOOKS LIKE THEY MAY BE ON THE FRINGE OF WHERE THE HEAVIER
SNOW BAND WILL SET UP. MODEL SNDGS INDICATE SUBSIDENCE WITH QUICKLY
LOWERING INVERSION HEIGHTS AFTER MIDNIGHT SO EXPECT DIMINISHING LES
INTENSITY BY THAT TIME. COLDEST TEMPS TONIGHT SHOULD BE ALONG THE
WISCONSIN BORDER WHERE SINGLE DIGITS COULD BE REACHED UNDER LIGHT
WINDS AND CLEARING SKIES OF SFC RDG. ELSEWHERE EXPECT LOWS TO BE
GENERALLY IN THE TEENS.
WEDNESDAY...THERE COULD BE SOME LINGERING LES OVER THE KEWEENAW
EARLY IN THE DAY BUT OTHERWISE SUBSIDENCE/DRYING AND LOWERING
INVERSION ALONG WITH QUICKLY BACKING FLOW SHOULD QUICKLY END LES.
SHORTWAVE QUICKLY MOVING ACROSS THE US/CANADIAN BORDER LATE IN THE
DAY MAY BRUSH THE NW PART OF LAKE SUPERIOR WITH LIGHT SNOW/FLURRIES
BUT OTHERWISE FORCING INDICATES BETTER CHC OF SNOW WILL STAY NORTH
AND WEST OF THE CWA. INCREASING H925 WINDS TO 35-45 KTS LATE IN
THE DAY ALONG WITH NEUTRAL TO SLIGHLY UNSTABLE TEMPERATURE PROFILE
FM SFC-H9 AND INCREASING PRESSURE FALLS OVR LK SUPERIOR AND INTO
ONTARIO MAY RESULT IN AREAS NEAR LK SUPERIOR OVR NCNTRL AREAS TO
GUST AOA 30 MPH TOWARD EVENING. EXPECT HIGHS IN THE UPR 20S AND
LOWER 30S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 424 PM EST TUE DEC 11 2012
JET STREAK WILL BE PUSHING THROUGH THE NEARLY ZONAL NORTHERN FLOW AT
THE START OF THE PERIOD. THE LEFT FRONT OF THIS 110KT STREAK WILL BE
OVER UPPER MICHIGAN AND AIDING A WEAK 1012MB SFC LOW TRACKING ALONG
THE WARM FRONT ON WEDNESDAY NIGHT. FAIRLY DRY SURFACE TO H850 LAYER
OVER MUCH OF THE LAND CWA...SO DON/T THINK THERE WOULD BE MUCH SNOW
HITTING THE SURFACE EVEN WITH THE STRONG WAA ALOFT. THUS...WILL
LIMIT THE EVENING SLIGHT CHANCES TO THE TIP OF THE KEWEENAW
PENINSULA WITH THE CHANCES OVER NORTHERN LAKE SUPERIOR. THIS FORCING
WILL SHIFT EAST DURING THE OVERNIGHT HOURS AND FOLLOW THE LOW INTO
ONTARIO.
BEFORE THE LOW DEPARTS THERE WILL BE STRONG WINDS ALOFT...ESPECIALLY
ABOVE THE INVERSION WHERE H900 WINDS APPROACH 45-50KTS ON WEDNESDAY
EVENING. BUT BELOW THE INVERSION WINDS ARE LIGHTER AND ONLY APPROACH
30-35KTS. AREA OF HIGHER PRESSURE FALLS OVER THE NORTHERN LAKE
INDICATES THE POTENTIAL FOR GUSTY WINDS ON WEDNESDAY EVENING. WITH
IT OCCURRING AT NIGHT...EXPECT THE SUSTAINED WINDS TO BE
HIGHER...BUT THE GUSTS MORE OCCASIONAL AND THE STRONGEST OVER THE
DOWNSLOPE AREAS OF THE NORTH CENTRAL. LOW LEVEL JET DIMINISHES
THROUGH THE NIGHT WITH THE LOW SHIFTING TO THE NORTHEAST AND EXPECT
THE SURFACE WINDS TO FOLLOW SUIT. THESE NIGHT TIME STRONG LOW LEVEL
JET ABOVE AN INVERSION ARE ALWAYS DIFFICULT TO DETERMINE THE AMOUNT
OF WIND THAT WILL MAKE IT TO THE SURFACE. BUFKIT MOMENTUM TRANSFER
IS USUALLY DECENT AT APPROXIMATE SUSTAINED WINDS/GUSTS...AND BOTH
NAM/GFS SOUNDINGS FOR STDM4 AND EAST BUOY ONLY SHOW A 6HR PERIOD
WEDNESDAY EVENING OF 30-35KTS. WILL LEAVE THE GALE WATCH AS
IS...SINCE HIGHER PLATFORMS WILL LIKELY SEE SOME OF THESE WINDS.
AREA WILL BE SOUTH OF THE TRAILING SURFACE TROUGH ON THURSDAY AND
EXPECT AN ABOVE NORMAL DAY OVER UPPER MICHIGAN. REMAINING
SOUTHERLY FLOW AND A FEW BREAKS IN THE MID CLOUDS SHOULD LEAD
TO ALL OF THE AREAS RISING ABOVE FREEZING DURING THE DAY.
MODELS HAVE THE IDEA OF THE TROUGH SAGGING SOUTH OVER SOUTHERN LAKE
SUPERIOR THURSDAY AFTERNOON AND REMAINING IN PLACE INTO FRIDAY
EVENING. THIS IS IN RESPONSE TO A SHORTWAVE THAT STREAKS THROUGH
THE ZONAL FLOW ON THURSDAY. AS THE TROUGH TRIES TO SAG SOUTH...LOW
LEVEL MOISTURE WILL INCREASE ON THE NORTH SIDE OF IT...BUT THERE IS
LITTLE TO NO CONVERGENCE ALONG THE TROUGH TO SUPPORT PRECIPITATION.
THUS...THE MAIN FORCING MECHANISM COMES FROM UPSLOPE FLOW. WITH THIS
SURFACE TROUGH STALLING OVER THE AREA...THE LOW LEVEL FLOW IS VERY
COMPLICATED AND UNCERTAIN AND MAKES PINPOINTING THE LIGHT
PRECIPITATION VERY DIFFICULT. SINCE THE TOP OF THE CLOUDS ARE
AROUND -8C AT 4KFT...DON/T EXPECT THERE TO BE MANY ICE CRYSTALS
IN THE CLOUDS AND REMOVE THE SNOW MENTION AND JUST GO WITH
DRIZZLE OR FREEZING DRIZZLE. LIGHT WESTERLY FLOW WOULD
FAVOR IT TO BE MAINLY OVER THE KEWEENAW ON THURSDAY AFTERNOON.
AFTER THAT...THERE ARE NO STRONG INDICATIONS ON WIND DIRECTIONS AND
WILL KEEP IT HIGHLIGHTED TO THE KEWEENAW FOR MUCH OF THE PERIOD
SINCE THEY WOULD HAVE MORE OPPORTUNITIES WITH THE VARIED WIND
DIRECTIONS. IN ADDITION...PICKED OUT A FEW LOCALIZED AREAS IN THE
NORTH CENTRAL TO HIGHLIGHT A SLIGHT CHANCE OF FREEZING
DRIZZLE BASED ON CONSENSUS WIND DIRECTIONS.
MODELS IN MUCH BETTER AGREEMENT THAN YESTERDAY HEADING INTO THE
WEEKEND...WITH THE GFS SHIFTING TOWARDS THE ECMWF/UKMET/GEM
SOLUTION. BUT...WITH THE INTERACTION OF SEVERAL DIFFERENT WAVES BY
THE TIME IT GETS HERE LEADS TO SOME UNCERTAINTY. THAT BEING
SAID...WITH THE CONSISTENCY OF THE ECMWF OVER THE LAST COUPLE DAYS
AND IT/S SUPERIOR SATELLITE BASED INITIALIZATION...WOULD WANT TO
LEAN TOWARDS THAT IDEA. WITH THE CURRENT TRACK...MUCH OF THE CWA
WILL SEE MEASURABLE...BUT LIGHT SNOW DUE TO THE BROAD AREA OF
CIRCULATION. BEST CHANCES WILL BE OVER THE SOUTHEAST HALF OF THE
CWA AND CLOSER TO THE LOW TRACK AND ALSO OVER NORTH CENTRAL UPPER
MICHIGAN WHERE UPSLOPE FLOW MAY INCREASE AMOUNTS. WITH THE ZONAL
FLOW IN PLACE AHEAD OF THIS WAVE...THERE WON/T BE MUCH COLD AIR TO
WORK WITH AND THAT LIMITS ANY LAKE ENHANCED POTENTIAL DURING THE
SYSTEM AND ALSO ON THE BACKSIDE. 12Z ECMWF HAS COME IN WITH A SLIGHT
SHIFT TO THE NORTH WITH THE LOW...SO FUTURE SHIFTS WILL HAVE TO
MONITOR IF THIS TREND CONTINUES.
FORECAST BECOMES MORE UNCERTAIN FOR MONDAY/TUESDAY OF NEXT
WEEK...WITH THE 00Z ECMWF HOLDING THE UPPER TROUGH OVER THE UPPER
GREAT LAKES REGION AND THE GFS AND IT/S ENSEMBLE PUSHING THE WAVE
OFF TO THE NEW ENGLAND STATES. 12Z ECMWF HAS TRENDED MORE
PROGRESSIVE...SO THERE COULD BE LIGHT LES OFF LAKE SUPERIOR MONDAY
AND TUESDAY AND SLIGHT CHANCE POPS REPRESENTS THAT WELL AT THIS
POINT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 626 PM EST TUE DEC 11 2012
CMX...EXPECT A DOMINANT LES BAND OVER WRN LK SUP IN LLVL W FLOW TO
IMPACT THIS SITE AT TIMES THIS EVNG...BRINGING IFR/LIFR CONDITIONS.
AS THE LARGER SCALE WIND BACKS TO THE SW LATER TNGT...THE HEAVIER
SHSN WL SHIFT TO THE N OF CMX...RESULTING IN PREDOMINANT MVFR
CONDITIONS. AS THE WIND BACKS FURTHER TO THE S ON WED...VFR WX WL BE
THE RULE WITH ARRIVAL OF DRIER AIR.
IWD/SAW...THERE WL BE PREDOMINANT MVFR CIGS THRU THIS EVNG
ASSOCIATED WITH THE PASSAGE OF A COLD FNT. VFR WX WL THEN PREVAIL
THE REST OF THE FCST PERIOD AFT MIDNGT AS THE WIND BACKS TO THE SW
THEN S AND ADVECTS DRIER AIR INTO THE AREA. EXPECT GUSTY S WINDS ON
WED AS THE PRES GRADIENT TIGHTENS OVER THE UPR LKS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EST TUE DEC 11 2012
SOUTHWEST WINDS TO 25 KTS WILL SHIFT WESTERLY THIS EVENING AS A
TROUGH MOVES THROUGH THE AREA AND THEN DIMINISH BRIEFLY BLO 20 KNOTS
LATE TONIGHT INTO WED MORNING. EXPECT INCREASING SOUTH TO SOUTHWEST
WINDS LATE WEDNESDAY INTO WEDNESDAY NIGHT. MARGINAL GALES TO 35
KNOTS ARE POSSIBLE OVER EASTERN PORTIONS OF LAKE SUPERIOR SO WILL
KEEP GALE WATCH IN EFFECT. A WEAK TROUGH DROPS ACROSS THE LAKE BY
THURSDAY EVENING. WINDS WILL DIMINISH SIGNIFICANTLY THURSDAY NIGHT
INTO FRIDAY IN THE WAKE OF THIS TROUGH. A LOW PRESSURE SYSTEM
DEVELOPING IN THE PLAINS PUSHES INTO WESTERN GREAT LAKES LATE
SATURDAY INTO SUNDAY WHILE HIGH PRESSURE MOVES ACROSS NEW ENGLAND.
WINDS SHOULD INCREASE FROM THE EAST ON SATURDAY OVER LAKE SUPERIOR.
SINCE EXACT TRACK AND DEPTH OF SFC LOW REMAINS UNCERTAIN AT THIS
TIME...WILL KEEP WINDS SUB-GALE FOR NOW.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ003.
LAKE SUPERIOR...
GALE WATCH FROM WEDNESDAY EVENING THROUGH LATE WEDNESDAY NIGHT
FOR LSZ265>267.
LAKE MICHIGAN...
GALE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR
LMZ248-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...KC
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
129 PM EST MON DEC 10 2012
.UPDATE...
ISSUED AT 1151 AM EST MON DEC 10 2012
WENT AHEAD AND CANCELLED THE WINTER WEATHER ADVISORY FOR GOGEBIC
COUNTY. THE TRICKY PART IS THAT LIGHT TO MODERATE SNOW SHOWERS
CONTINUE TO ROTATE ACROSS FAR WESTERN LAKE SUPERIOR. HOWEVER...THE
LATEST RADAR TRENDS HAVE BEEN SHOWING STEADY OR A SLIGHT EASTWARD
PUSH TO THE BAND CLOSEST TO THE GOGEBIC SHORELINE. GIVEN THE LOW
TOPPED CLOUDS...ITS BEEN DIFFICULT TO SEE EXACTLY WHERE THE EASTERN
EXTENT OF THE SNOW BAND IS LOCATED...HOWEVER WEBCAMS OVER ONTONAGON
COUNTY DO NOT SHOW MUCH AND BACK UP THE IDEA OF CANCELING THE
ADVISORY. WILL CONTINUE TO MONITOR THE PROGRESS OF THE 850MB WIND
FOLLOWING SHOWERS OVER LAKE SUPERIOR. THE LATEST THINKING IS THAT
WITH 850MB WINDS BECOMING LIGHT AROUND 18Z...AND THEN PUSHING OUT OF
THE SW THROUGH LATE AFTERNOON...THAT SNOW MAY MOVE BACK TOWARD
ONTONAGON AND N HOUGHTON COUNTIES BY LATE AFTERNOON. WITH CONTINUED
LIGHT LAKE EFFECT SNOW SHOWERS...THE ADVISORY FOR MARQUETTE COUNTY
WILL BE ALLOWED TO EXPIRE AT 18Z.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 546 AM EST MON DEC 10 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH AXIS
FROM NW ONTARIO INTO THE SRN PLAINS. THE SHORTWAVE TROUGH THAT
BROUGHT HEAVY SNOW TO THE UPPER MS VALLEY SUNDAY HAS
SHEARED/WEAKENED AND LIFTED QUICKLY TO THE EAST OF UPPER MICHIGAN.
CYCLONIC NNE LOW LEVEL FLOW COMBINED WITH ABUNDANT 850-700 MB
MOISTURE AND 850 MB TEMPS TO ARUOND -11C SUPPORTED LAKE EFFECT SNOW
INTO N CNTRL UPPER MI. 850-700 MB FGEN AHEAD OF AN 850-700 MB
THERMAL TROUGH INTO NRN MN ALSO SUPPORTED SOME LIGHT SNOW OVER NE MN
AND HELPED ENHANCE THE LES INTO FAR NW WI. SO FAR...LAND BREEZE AND
LAKE INDUCED TROUGHING HAS KEPT THE MAIN LES BANDS WEST OF IWD
THROUGH 10Z.
MAIN FCST CONCERNS ARE LES TRENDS AND SNOW AMOUNTS.
TODAY...
SATELLITE TRENDS AND MODELS SUGGEST THAT ANY LINGERING
SYNOPTIC SCALE LIFT WILL DEPART EARLY TODAY WITH THE 850-700 MB
MOISUTRE ALSO THINNING OUT BY THIS AFTERNOON ALONG WITH ONLY A
GRADUAL BACKING TREND IN THE LOW LEVEL WIND FROM NE TO NORTH. THIS
SHOULD KEEP THE LES GOING INTO NORTH CENTRAL MICHIGAN GOING THIS
MORNING WITH LIGHT TO MODERATE SNOWFALL RATES...ESPECIALLY INTO
UPSLOPE FLOW LOCATIONS. THIS SHOULD PRODUCE AN ADDITIONAL 1 TO 3
INCHES OF SNOW MAINLY IN THE HIGHER TERRAIN LOCATIONS OF MARQUETTE
COUNTY FROM THE HURON MOUNTAINS TO NEGAUNEE/ISHPMEMING AND GWINN.
HIGH RES MODELS HAVE BEEN CONSISTENT IN GRADUALLY SHIFTING THE AXIS
OF LEVEL CONV AND BRINGING THE LES BANDS INTO WESTERN GOGEBIC COUNTY
BY AROUND 12Z. EVEN THOUGH THERE MAY SOME DELAY TO THE ONSET OF
HEAVIER SNOW IF THE TROUGH MOVEMENT IS SLOWER THAN EXPECTED...A
PERIOD OF MODERATE TO HEAVY SNOW VCNTY IWD COULD BRING AT LEAST 1 TO
4 INCHES OF SNOW. HOWEVER...CONFIDENCE IN THE TIMING/DURATION OF THE
HEAVIER BAND IS STILL LIMITED. AS A WEAK RIDGE BUILDS TOWARD THE AREA
THIS AFTERNOON AND WINDS/CONV WEAKENS...THE SNOW SHOULD DIMINISH OVER
BOTH THE WEST AND N CNTRL UPPER MI.
TONIGHT...
A A WEAK SHORTWAVE AND SFC TROUGH REFLECTION WILL APPROACH
THE AREA BRINGING A SHIFT TO SW TO S WINDS. THIS SHOULD PUSH ANY
REMANING LES FROM LAKE SUPERIOR OFFSHORE DURING THE EVENING. WITH
THE VERY WEAK WIND FIELDS...THERE IS THE POSSIBILITY THAT A
SHORELINE PARALLEL OR MESO-LOW BAND MAY BRUSH THE WEST UPPER MI
SHORELINE. A WEAK BAND 700-300 MB QVECTOR CONV AND ISENTROPIC LIFT
AHEAD OF THIS FEATURE MAY SUPPORT SOME LIGHT SNOW INTO WEST UPPER
MICHIGAN. HOWEVER...ONLY SLIGHT CHANCE POPS WERE MENTIONED.
INCREASING LOW LEVEL CONV SRLY FLOW OFF OF LAKE MICHIGAN MAY ALSO
BRING AN LES BAND INTO THE SE CWA LATE BUT SHOULD HOLD OFF MAINLY
UNTIL TUES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 546 AM EST MON DEC 10 2012
SURFACE RIDGE AXIS WILL BE EAST OF THE AREA BY TUESDAY MORNING. AS
NEXT UPPER TROUGH MOVES INTO WESTERN ONTARIO WITH ASSOCIATED WEAK
SURFACE LOW WINDS WILL BECOME SOUTHERLY ACROSS THE ENTIRE AREA. 85H
TEMPS WILL REMAIN LOW ENOUGH...-10 TO -12...TO SUPPORT A LAKE EFFECT
SNOW BAND OFF OF LAKE MICHIGAN INTO THE EASTERN U.P. WINDS WILL
SLOWLY BUT STEADILY VEER THROUGH THE DAY ALLOWING THE BAND TO BE
TRANSIENT FROM WEST TO EAST WHICH SHOULD LIMIT SNOWFALL AMOUNTS OVER
EASTERN SCHOOLCRAFT AND LUCE COUNTIES IN THE 1 TO AS MUCH AS 3 INCH
RANGE.
AS SURFACE LOW MOVES ACROSS ONTARIO...SURFACE TROUGH WILL CROSS LAKE
SUPERIOR ALLOWING WINDS TO BECOME WESTERLY AND 85H TEMPS TO FALL TO
-14 BRIEFLY OVER WESTERN LAKE SUPERIOR. EXPECT SOME LAKE EFFECT SNOW
TO AFFECT THE KEWEENAW PENINSULA TUE EVENING/TUE NIGHT BEFORE WARM
ADVECTION REGIME SETS IN ACROSS THE WESTERN LAKE.
SOUTHERLY WINDS WILL RETURN FOR WEDNESDAY INTO THURSDAY AS ANOTHER
WEAK DISTURBANCE SKIRTS BY JUST NORTH OF THE AREA. ANY FORCING FOR
PRECIPITATION SHOULD REMAIN OVER NORTHERN LAKE SUPERIOR INTO
ONTARIO. 85H TEMPS FOR WEDNESDAY AND THURSDAY WILL BE IN THE 0 TO -4
RANGE RESULTING IN DAYTIME TEMPERATURES A FEW DEGREES ABOVE NORMAL.
VERY LITTLE CONFIDENCE IN THE FORECAST BEYOND THURSDAY WITH MEDIUM
RANGE MODELS SHOWING LARGE SCALE DISCREPANCIES. ECMWF HAS BEEN
CONSISTENT IN HINTING AT A POTENTIAL STORM SYSTEM DEVELOPING OVER
THE PLAINS AND LIFTING INTO THE GREAT LAKES OVER THE WEEKEND WITH
THE GFS SHOWING HIGH PRESSURE OVER THE GREAT LAKES NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 129 PM EST MON DEC 10 2012
HIGH END IFR TO MVFR CEILINGS REMAIN CENTERED ACROSS UPPER MI EARLY
THIS AFTERNOON. HIGH PRESSURE PUSHING IN FROM THE N AND W WILL
SLOWLY ERODE LINGERING SNOW SHOWERS OFF LAKE SUPERIOR...AND BRING IN
VFR CEILINGS LATE TONIGHT. THE NEXT LOW PRESSURE SYSTEM WILL BE
EDGING EAST...TO ONTARIO AND W UPPER MI OVERNIGHT. AS A
RESULT...EXPECT LIGHT WINDS TO BECOME S AND INCREASE TO AROUND 10KTS
BY MID MORNING TUESDAY. BY 18Z THURSDAY THE TROUGH EXTENDING FROM
THE LOW WILL BE AROUND CMX AND IWD...WITH SLOWLY LOWERING CEILINGS
THROUGH THE DAY TUESDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 546 AM EST MON DEC 10 2012
NORTHERLY WINDS OF 20 TO 30 KNOTS EARLY TODAY ARE EXPECTED TO
DIMINISH AS A TROUGH TO THE SOUTH OF UPPER MICHIGAN GRADUALLY
WEAKENS AND SHIFTS TO THE SOUTHEAST. BEHIND THIS FEATURE...A SERIES
OF WEAK RIDGES AND TROUGHS WILL AFFECT LAKE SUPERIOR DURING THE REST
OF THE WORK WEEK AND KEEP WINDS BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KF
SHORT TERM...JLB
LONG TERM...MZ
AVIATION...KF
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1152 AM EST MON DEC 10 2012
.UPDATE...
ISSUED AT 1151 AM EST MON DEC 10 2012
WENT AHEAD AND CANCELLED THE WINTER WEATHER ADVISORY FOR GOGEBIC
COUNTY. THE TRICKY PART IS THAT LIGHT TO MODERATE SNOW SHOWERS
CONTINUE TO ROTATE ACROSS FAR WESTERN LAKE SUPERIOR. HOWEVER...THE
LATEST RADAR TRENDS HAVE BEEN SHOWING STEADY OR A SLIGHT EASTWARD
PUSH TO THE BAND CLOSEST TO THE GOGEBIC SHORELINE. GIVEN THE LOW
TOPPED CLOUDS...ITS BEEN DIFFICULT TO SEE EXACTLY WHERE THE EASTERN
EXTENT OF THE SNOW BAND IS LOCATED...HOWEVER WEBCAMS OVER ONTONAGON
COUNTY DO NOT SHOW MUCH AND BACK UP THE IDEA OF CANCELING THE
ADVISORY. WILL CONTINUE TO MONITOR THE PROGRESS OF THE 850MB WIND
FOLLOWING SHOWERS OVER LAKE SUPERIOR. THE LATEST THINKING IS THAT
WITH 850MB WINDS BECOMING LIGHT AROUND 18Z...AND THEN PUSHING OUT OF
THE SW THROUGH LATE AFTERNOON...THAT SNOW MAY MOVE BACK TOWARD
ONTONAGON AND N HOUGHTON COUNTIES BY LATE AFTERNOON. WITH CONTINUED
LIGHT LAKE EFFECT SNOW SHOWERS...THE ADVISORY FOR MARQUETTE COUNTY
WILL BE ALLOWED TO EXPIRE AT 18Z.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 546 AM EST MON DEC 10 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH AXIS
FROM NW ONTARIO INTO THE SRN PLAINS. THE SHORTWAVE TROUGH THAT
BROUGHT HEAVY SNOW TO THE UPPER MS VALLEY SUNDAY HAS
SHEARED/WEAKENED AND LIFTED QUICKLY TO THE EAST OF UPPER MICHIGAN.
CYCLONIC NNE LOW LEVEL FLOW COMBINED WITH ABUNDANT 850-700 MB
MOISTURE AND 850 MB TEMPS TO ARUOND -11C SUPPORTED LAKE EFFECT SNOW
INTO N CNTRL UPPER MI. 850-700 MB FGEN AHEAD OF AN 850-700 MB
THERMAL TROUGH INTO NRN MN ALSO SUPPORTED SOME LIGHT SNOW OVER NE MN
AND HELPED ENHANCE THE LES INTO FAR NW WI. SO FAR...LAND BREEZE AND
LAKE INDUCED TROUGHING HAS KEPT THE MAIN LES BANDS WEST OF IWD
THROUGH 10Z.
MAIN FCST CONCERNS ARE LES TRENDS AND SNOW AMOUNTS.
TODAY...
SATELLITE TRENDS AND MODELS SUGGEST THAT ANY LINGERING
SYNOPTIC SCALE LIFT WILL DEPART EARLY TODAY WITH THE 850-700 MB
MOISUTRE ALSO THINNING OUT BY THIS AFTERNOON ALONG WITH ONLY A
GRADUAL BACKING TREND IN THE LOW LEVEL WIND FROM NE TO NORTH. THIS
SHOULD KEEP THE LES GOING INTO NORTH CENTRAL MICHIGAN GOING THIS
MORNING WITH LIGHT TO MODERATE SNOWFALL RATES...ESPECIALLY INTO
UPSLOPE FLOW LOCATIONS. THIS SHOULD PRODUCE AN ADDITIONAL 1 TO 3
INCHES OF SNOW MAINLY IN THE HIGHER TERRAIN LOCATIONS OF MARQUETTE
COUNTY FROM THE HURON MOUNTAINS TO NEGAUNEE/ISHPMEMING AND GWINN.
HIGH RES MODELS HAVE BEEN CONSISTENT IN GRADUALLY SHIFTING THE AXIS
OF LEVEL CONV AND BRINGING THE LES BANDS INTO WESTERN GOGEBIC COUNTY
BY AROUND 12Z. EVEN THOUGH THERE MAY SOME DELAY TO THE ONSET OF
HEAVIER SNOW IF THE TROUGH MOVEMENT IS SLOWER THAN EXPECTED...A
PERIOD OF MODERATE TO HEAVY SNOW VCNTY IWD COULD BRING AT LEAST 1 TO
4 INCHES OF SNOW. HOWEVER...CONFIDENCE IN THE TIMING/DURATION OF THE
HEAVIER BAND IS STILL LIMITED. AS A WEAK RIDGE BUILDS TOWARD THE AREA
THIS AFTERNOON AND WINDS/CONV WEAKENS...THE SNOW SHOULD DIMINISH OVER
BOTH THE WEST AND N CNTRL UPPER MI.
TONIGHT...
A A WEAK SHORTWAVE AND SFC TROUGH REFLECTION WILL APPROACH
THE AREA BRINGING A SHIFT TO SW TO S WINDS. THIS SHOULD PUSH ANY
REMANING LES FROM LAKE SUPERIOR OFFSHORE DURING THE EVENING. WITH
THE VERY WEAK WIND FIELDS...THERE IS THE POSSIBILITY THAT A
SHORELINE PARALLEL OR MESO-LOW BAND MAY BRUSH THE WEST UPPER MI
SHORELINE. A WEAK BAND 700-300 MB QVECTOR CONV AND ISENTROPIC LIFT
AHEAD OF THIS FEATURE MAY SUPPORT SOME LIGHT SNOW INTO WEST UPPER
MICHIGAN. HOWEVER...ONLY SLIGHT CHANCE POPS WERE MENTIONED.
INCREASING LOW LEVEL CONV SRLY FLOW OFF OF LAKE MICHIGAN MAY ALSO
BRING AN LES BAND INTO THE SE CWA LATE BUT SHOULD HOLD OFF MAINLY
UNTIL TUES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 546 AM EST MON DEC 10 2012
SURFACE RIDGE AXIS WILL BE EAST OF THE AREA BY TUESDAY MORNING. AS
NEXT UPPER TROUGH MOVES INTO WESTERN ONTARIO WITH ASSOCIATED WEAK
SURFACE LOW WINDS WILL BECOME SOUTHERLY ACROSS THE ENTIRE AREA. 85H
TEMPS WILL REMAIN LOW ENOUGH...-10 TO -12...TO SUPPORT A LAKE EFFECT
SNOW BAND OFF OF LAKE MICHIGAN INTO THE EASTERN U.P. WINDS WILL
SLOWLY BUT STEADILY VEER THROUGH THE DAY ALLOWING THE BAND TO BE
TRANSIENT FROM WEST TO EAST WHICH SHOULD LIMIT SNOWFALL AMOUNTS OVER
EASTERN SCHOOLCRAFT AND LUCE COUNTIES IN THE 1 TO AS MUCH AS 3 INCH
RANGE.
AS SURFACE LOW MOVES ACROSS ONTARIO...SURFACE TROUGH WILL CROSS LAKE
SUPERIOR ALLOWING WINDS TO BECOME WESTERLY AND 85H TEMPS TO FALL TO
-14 BRIEFLY OVER WESTERN LAKE SUPERIOR. EXPECT SOME LAKE EFFECT SNOW
TO AFFECT THE KEWEENAW PENINSULA TUE EVENING/TUE NIGHT BEFORE WARM
ADVECTION REGIME SETS IN ACROSS THE WESTERN LAKE.
SOUTHERLY WINDS WILL RETURN FOR WEDNESDAY INTO THURSDAY AS ANOTHER
WEAK DISTURBANCE SKIRTS BY JUST NORTH OF THE AREA. ANY FORCING FOR
PRECIPITATION SHOULD REMAIN OVER NORTHERN LAKE SUPERIOR INTO
ONTARIO. 85H TEMPS FOR WEDNESDAY AND THURSDAY WILL BE IN THE 0 TO -4
RANGE RESULTING IN DAYTIME TEMPERATURES A FEW DEGREES ABOVE NORMAL.
VERY LITTLE CONFIDENCE IN THE FORECAST BEYOND THURSDAY WITH MEDIUM
RANGE MODELS SHOWING LARGE SCALE DISCREPANCIES. ECMWF HAS BEEN
CONSISTENT IN HINTING AT A POTENTIAL STORM SYSTEM DEVELOPING OVER
THE PLAINS AND LIFTING INTO THE GREAT LAKES OVER THE WEEKEND WITH
THE GFS SHOWING HIGH PRESSURE OVER THE GREAT LAKES NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 702 AM EST MON DEC 10 2012
EXPECT PREDOMINANT MVFR CONDITIONS TO DOMINATE THIS FCST PERIOD AT
ALL 3 TAF SITES WITH LINGERING LOW LEVEL MOISTURE SLOWLY WEAKENING
CYCLONIC NNE FLOW UNDER SUBSIDENCE LEFT IN THE WAKE OF DEPARTING
DISTURBANCE. THE MAJOR EXCEPTION WILL BE A PERIOD OF IFR CONDITIONS
THIS MORNING UNDER SOME HEAVIER LK EFFECT SHSN THAT WILL IMPACT IWD
AND SAW...LOCATIONS FAVORED BY THE EXPECTED NNE WIND. CONDITIONS MAY
IMPROVE TO VFR THIS EVENING AS WINDS BECOME SRLY AHEAD OF A WEAK
TROUGH.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 546 AM EST MON DEC 10 2012
NORTHERLY WINDS OF 20 TO 30 KNOTS EARLY TODAY ARE EXPECTED TO
DIMINISH AS A TROUGH TO THE SOUTH OF UPPER MICHIGAN GRADUALLY
WEAKENS AND SHIFTS TO THE SOUTHEAST. BEHIND THIS FEATURE...A SERIES
OF WEAK RIDGES AND TROUGHS WILL AFFECT LAKE SUPERIOR DURING THE REST
OF THE WORK WEEK AND KEEP WINDS BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ005.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KF
SHORT TERM...JLB
LONG TERM...MZ
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
709 AM EST MON DEC 10 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 546 AM EST MON DEC 10 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH AXIS
FROM NW ONTARIO INTO THE SRN PLAINS. THE SHORTWAVE TROUGH THAT
BROUGHT HEAVY SNOW TO THE UPPER MS VALLEY SUNDAY HAS
SHEARED/WEAKENED AND LIFTED QUICKLY TO THE EAST OF UPPER MICHIGAN.
CYCLONIC NNE LOW LEVEL FLOW COMBINED WITH ABUNDANT 850-700 MB
MOISTURE AND 850 MB TEMPS TO ARUOND -11C SUPPORTED LAKE EFFECT SNOW
INTO N CNTRL UPPER MI. 850-700 MB FGEN AHEAD OF AN 850-700 MB
THERMAL TROUGH INTO NRN MN ALSO SUPPORTED SOME LIGHT SNOW OVER NE MN
AND HELPED ENHANCE THE LES INTO FAR NW WI. SO FAR...LAND BREEZE AND
LAKE INDUCED TROUGHING HAS KEPT THE MAIN LES BANDS WEST OF IWD
THROUGH 10Z.
MAIN FCST CONCERNS ARE LES TRENDS AND SNOW AMOUNTS.
TODAY...
SATELLITE TRENDS AND MODELS SUGGEST THAT ANY LINGERING
SYNOPTIC SCALE LIFT WILL DEPART EARLY TODAY WITH THE 850-700 MB
MOISUTRE ALSO THINNING OUT BY THIS AFTERNOON ALONG WITH ONLY A
GRADUAL BACKING TREND IN THE LOW LEVEL WIND FROM NE TO NORTH. THIS
SHOULD KEEP THE LES GOING INTO NORTH CENTRAL MICHIGAN GOING THIS
MORNING WITH LIGHT TO MODERATE SNOWFALL RATES...ESPECIALLY INTO
UPSLOPE FLOW LOCATIONS. THIS SHOULD PRODUCE AN ADDITIONAL 1 TO 3
INCHES OF SNOW MAINLY IN THE HIGHER TERRAIN LOCATIONS OF MARQUETTE
COUNTY FROM THE HURON MOUNTAINS TO NEGAUNEE/ISHPMEMING AND GWINN.
HIGH RES MODELS HAVE BEEN CONSISTENT IN GRADUALLY SHIFTING THE AXIS
OF LEVEL CONV AND BRINGING THE LES BANDS INTO WESTERN GOGEBIC COUNTY
BY AROUND 12Z. EVEN THOUGH THERE MAY SOME DELAY TO THE ONSET OF
HEAVIER SNOW IF THE TROUGH MOVEMENT IS SLOWER THAN EXPECTED...A
PERIOD OF MODERATE TO HEAVY SNOW VCNTY IWD COULD BRING AT LEAST 1 TO
4 INCHES OF SNOW. HOWEVER...CONFIDENCE IN THE TIMING/DURATION OF THE
HEAVIER BAND IS STILL LIMITED. AS A WEAK RIDGE BUILDS TOWARD THE AREA
THIS AFTERNOON AND WINDS/CONV WEAKENS...THE SNOW SHOULD DIMINISH OVER
BOTH THE WEST AND N CNTRL UPPER MI.
TONIGHT...
A A WEAK SHORTWAVE AND SFC TROUGH REFLECTION WILL APPROACH
THE AREA BRINGING A SHIFT TO SW TO S WINDS. THIS SHOULD PUSH ANY
REMANING LES FROM LAKE SUPERIOR OFFSHORE DURING THE EVENING. WITH
THE VERY WEAK WIND FIELDS...THERE IS THE POSSIBILITY THAT A
SHORELINE PARALLEL OR MESO-LOW BAND MAY BRUSH THE WEST UPPER MI
SHORELINE. A WEAK BAND 700-300 MB QVECTOR CONV AND ISENTROPIC LIFT
AHEAD OF THIS FEATURE MAY SUPPORT SOME LIGHT SNOW INTO WEST UPPER
MICHIGAN. HOWEVER...ONLY SLIGHT CHANCE POPS WERE MENTIONED.
INCREASING LOW LEVEL CONV SRLY FLOW OFF OF LAKE MICHIGAN MAY ALSO
BRING AN LES BAND INTO THE SE CWA LATE BUT SHOULD HOLD OFF MAINLY
UNTIL TUES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 546 AM EST MON DEC 10 2012
SURFACE RIDGE AXIS WILL BE EAST OF THE AREA BY TUESDAY MORNING. AS
NEXT UPPER TROUGH MOVES INTO WESTERN ONTARIO WITH ASSOCIATED WEAK
SURFACE LOW WINDS WILL BECOME SOUTHERLY ACROSS THE ENTIRE AREA. 85H
TEMPS WILL REMAIN LOW ENOUGH...-10 TO -12...TO SUPPORT A LAKE EFFECT
SNOW BAND OFF OF LAKE MICHIGAN INTO THE EASTERN U.P. WINDS WILL
SLOWLY BUT STEADILY VEER THROUGH THE DAY ALLOWING THE BAND TO BE
TRANSIENT FROM WEST TO EAST WHICH SHOULD LIMIT SNOWFALL AMOUNTS OVER
EASTERN SCHOOLCRAFT AND LUCE COUNTIES IN THE 1 TO AS MUCH AS 3 INCH
RANGE.
AS SURFACE LOW MOVES ACROSS ONTARIO...SURFACE TROUGH WILL CROSS LAKE
SUPERIOR ALLOWING WINDS TO BECOME WESTERLY AND 85H TEMPS TO FALL TO
-14 BRIEFLY OVER WESTERN LAKE SUPERIOR. EXPECT SOME LAKE EFFECT SNOW
TO AFFECT THE KEWEENAW PENINSULA TUE EVENING/TUE NIGHT BEFORE WARM
ADVECTION REGIME SETS IN ACROSS THE WESTERN LAKE.
SOUTHERLY WINDS WILL RETURN FOR WEDNESDAY INTO THURSDAY AS ANOTHER
WEAK DISTURBANCE SKIRTS BY JUST NORTH OF THE AREA. ANY FORCING FOR
PRECIPITATION SHOULD REMAIN OVER NORTHERN LAKE SUPERIOR INTO
ONTARIO. 85H TEMPS FOR WEDNESDAY AND THURSDAY WILL BE IN THE 0 TO -4
RANGE RESULTING IN DAYTIME TEMPERATURES A FEW DEGREES ABOVE NORMAL.
VERY LITTLE CONFIDENCE IN THE FORECAST BEYOND THURSDAY WITH MEDIUM
RANGE MODELS SHOWING LARGE SCALE DISCREPANCIES. ECMWF HAS BEEN
CONSISTENT IN HINTING AT A POTENTIAL STORM SYSTEM DEVELOPING OVER
THE PLAINS AND LIFTING INTO THE GREAT LAKES OVER THE WEEKEND WITH
THE GFS SHOWING HIGH PRESSURE OVER THE GREAT LAKES NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 702 AM EST MON DEC 10 2012
EXPECT PREDOMINANT MVFR CONDITIONS TO DOMINATE THIS FCST PERIOD AT
ALL 3 TAF SITES WITH LINGERING LOW LEVEL MOISTURE SLOWLY WEAKENING
CYCLONIC NNE FLOW UNDER SUBSIDENCE LEFT IN THE WAKE OF DEPARTING
DISTURBANCE. THE MAJOR EXCEPTION WILL BE A PERIOD OF IFR CONDITIONS
THIS MORNING UNDER SOME HEAVIER LK EFFECT SHSN THAT WILL IMPACT IWD
AND SAW...LOCATIONS FAVORED BY THE EXPECTED NNE WIND. CONDITIONS MAY
IMPROVE TO VFR THIS EVENING AS WINDS BECOME SRLY AHEAD OF A WEAK
TROUGH.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 546 AM EST MON DEC 10 2012
NORTHERLY WINDS OF 20 TO 30 KNOTS EARLY TODAY ARE EXPECTED TO
DIMINISH AS A TROUGH TO THE SOUTH OF UPPER MICHIGAN GRADUALLY
WEAKENS AND SHIFTS TO THE SOUTHEAST. BEHIND THIS FEATURE...A SERIES
OF WEAK RIDGES AND TROUGHS WILL AFFECT LAKE SUPERIOR DURING THE REST
OF THE WORK WEEK AND KEEP WINDS BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR MIZ005-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MZ
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
550 AM EST MON DEC 10 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 546 AM EST MON DEC 10 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH AXIS
FROM NW ONTARIO INTO THE SRN PLAINS. THE SHORTWAVE TROUGH THAT
BROUGHT HEAVY SNOW TO THE UPPER MS VALLEY SUNDAY HAS
SHEARED/WEAKENED AND LIFTED QUICKLY TO THE EAST OF UPPER MICHIGAN.
CYCLONIC NNE LOW LEVEL FLOW COMBINED WITH ABUNDANT 850-700 MB
MOISTURE AND 850 MB TEMPS TO ARUOND -11C SUPPORTED LAKE EFFECT SNOW
INTO N CNTRL UPPER MI. 850-700 MB FGEN AHEAD OF AN 850-700 MB
THERMAL TROUGH INTO NRN MN ALSO SUPPORTED SOME LIGHT SNOW OVER NE MN
AND HELPED ENHANCE THE LES INTO FAR NW WI. SO FAR...LAND BREEZE AND
LAKE INDUCED TROUGHING HAS KEPT THE MAIN LES BANDS WEST OF IWD
THROUGH 10Z.
MAIN FCST CONCERNS ARE LES TRENDS AND SNOW AMOUNTS.
TODAY...
SATELLITE TRENDS AND MODELS SUGGEST THAT ANY LINGERING
SYNOPTIC SCALE LIFT WILL DEPART EARLY TODAY WITH THE 850-700 MB
MOISUTRE ALSO THINNING OUT BY THIS AFTERNOON ALONG WITH ONLY A
GRADUAL BACKING TREND IN THE LOW LEVEL WIND FROM NE TO NORTH. THIS
SHOULD KEEP THE LES GOING INTO NORTH CENTRAL MICHIGAN GOING THIS
MORNING WITH LIGHT TO MODERATE SNOWFALL RATES...ESPECIALLY INTO
UPSLOPE FLOW LOCATIONS. THIS SHOULD PRODUCE AN ADDITIONAL 1 TO 3
INCHES OF SNOW MAINLY IN THE HIGHER TERRAIN LOCATIONS OF MARQUETTE
COUNTY FROM THE HURON MOUNTAINS TO NEGAUNEE/ISHPMEMING AND GWINN.
HIGH RES MODELS HAVE BEEN CONSISTENT IN GRADUALLY SHIFTING THE AXIS
OF LEVEL CONV AND BRINGING THE LES BANDS INTO WESTERN GOGEBIC COUNTY
BY AROUND 12Z. EVEN THOUGH THERE MAY SOME DELAY TO THE ONSET OF
HEAVIER SNOW IF THE TROUGH MOVEMENT IS SLOWER THAN EXPECTED...A
PERIOD OF MODERATE TO HEAVY SNOW VCNTY IWD COULD BRING AT LEAST 1 TO
4 INCHES OF SNOW. HOWEVER...CONFIDENCE IN THE TIMING/DURATION OF THE
HEAVIER BAND IS STILL LIMITED. AS A WEAK RIDGE BUILDS TOWARD THE AREA
THIS AFTERNOON AND WINDS/CONV WEAKENS...THE SNOW SHOULD DIMINISH OVER
BOTH THE WEST AND N CNTRL UPPER MI.
TONIGHT...
A A WEAK SHORTWAVE AND SFC TROUGH REFLECTION WILL APPROACH
THE AREA BRINGING A SHIFT TO SW TO S WINDS. THIS SHOULD PUSH ANY
REMANING LES FROM LAKE SUPERIOR OFFSHORE DURING THE EVENING. WITH
THE VERY WEAK WIND FIELDS...THERE IS THE POSSIBILITY THAT A
SHORELINE PARALLEL OR MESO-LOW BAND MAY BRUSH THE WEST UPPER MI
SHORELINE. A WEAK BAND 700-300 MB QVECTOR CONV AND ISENTROPIC LIFT
AHEAD OF THIS FEATURE MAY SUPPORT SOME LIGHT SNOW INTO WEST UPPER
MICHIGAN. HOWEVER...ONLY SLIGHT CHANCE POPS WERE MENTIONED.
INCREASING LOW LEVEL CONV SRLY FLOW OFF OF LAKE MICHIGAN MAY ALSO
BRING AN LES BAND INTO THE SE CWA LATE BUT SHOULD HOLD OFF MAINLY
UNTIL TUES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 546 AM EST MON DEC 10 2012
SURFACE RIDGE AXIS WILL BE EAST OF THE AREA BY TUESDAY MORNING. AS
NEXT UPPER TROUGH MOVES INTO WESTERN ONTARIO WITH ASSOCIATED WEAK
SURFACE LOW WINDS WILL BECOME SOUTHERLY ACROSS THE ENTIRE AREA. 85H
TEMPS WILL REMAIN LOW ENOUGH...-10 TO -12...TO SUPPORT A LAKE EFFECT
SNOW BAND OFF OF LAKE MICHIGAN INTO THE EASTERN U.P. WINDS WILL
SLOWLY BUT STEADILY VEER THROUGH THE DAY ALLOWING THE BAND TO BE
TRANSIENT FROM WEST TO EAST WHICH SHOULD LIMIT SNOWFALL AMOUNTS OVER
EASTERN SCHOOLCRAFT AND LUCE COUNTIES IN THE 1 TO AS MUCH AS 3 INCH
RANGE.
AS SURFACE LOW MOVES ACROSS ONTARIO...SURFACE TROUGH WILL CROSS LAKE
SUPERIOR ALLOWING WINDS TO BECOME WESTERLY AND 85H TEMPS TO FALL TO
-14 BRIEFLY OVER WESTERN LAKE SUPERIOR. EXPECT SOME LAKE EFFECT SNOW
TO AFFECT THE KEWEENAW PENINSULA TUE EVENING/TUE NIGHT BEFORE WARM
ADVECTION REGIME SETS IN ACROSS THE WESTERN LAKE.
SOUTHERLY WINDS WILL RETURN FOR WEDNESDAY INTO THURSDAY AS ANOTHER
WEAK DISTURBANCE SKIRTS BY JUST NORTH OF THE AREA. ANY FORCING FOR
PRECIPITATION SHOULD REMAIN OVER NORTHERN LAKE SUPERIOR INTO
ONTARIO. 85H TEMPS FOR WEDNESDAY AND THURSDAY WILL BE IN THE 0 TO -4
RANGE RESULTING IN DAYTIME TEMPERATURES A FEW DEGREES ABOVE NORMAL.
VERY LITTLE CONFIDENCE IN THE FORECAST BEYOND THURSDAY WITH MEDIUM
RANGE MODELS SHOWING LARGE SCALE DISCREPANCIES. ECMWF HAS BEEN
CONSISTENT IN HINTING AT A POTENTIAL STORM SYSTEM DEVELOPING OVER
THE PLAINS AND LIFTING INTO THE GREAT LAKES OVER THE WEEKEND WITH
THE GFS SHOWING HIGH PRESSURE OVER THE GREAT LAKES NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 142 AM EST MON DEC 10 2012
EXPECT PREDOMINANT MVFR CONDITIONS TO DOMINATE THIS FCST PERIOD AT
ALL 3 TAF SITES WITH LINGERING LLVL MSTR/SLOWLY WEAKENING CYC NNE
FLOW UNDER SUBSIDENCE LEFT IN THE WAKE OF DEPARTING DISTURBANCE
RESPONSIBLE FOR SN ON SUN EVNG. THE MAJOR EXCEPTION WL BE A PERIOD
OF IFR CONDITIONS THIS MRNG UNDER SOME HEAVIER LK EFFECT SHSN THAT
WL IMPACT IWD AND SAW...LOCATIONS FAVORED BY THE EXPECTED NNE WIND.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 546 AM EST MON DEC 10 2012
NORTHERLY WINDS OF 20 TO 30 KNOTS EARLY TODAY ARE EXPECTED TO
DIMINISH AS A TROUGH TO THE SOUTH OF UPPER MICHIGAN GRADUALLY
WEAKENS AND SHIFTS TO THE SOUTHEAST. BEHIND THIS FEATURE...A SERIES
OF WEAK RIDGES AND TROUGHS WILL AFFECT LAKE SUPERIOR DURING THE REST
OF THE WORK WEEK AND KEEP WINDS BELOW 25KTS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR MIZ005-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MZ
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DULUTH MN
634 PM CST TUE DEC 11 2012
.AVIATION.../00Z TAF ISSUANCE/
AN AREA OF LOW CLOUDS WITH MVFR CLOUDS ASSOC WITH A DEPARTING
SHORTWAVE WILL GRADUALLY DIMINISH OR DISSIPATE OVERNIGHT TONIGHT.
LIGHT SNOW WITH LOCALIZED MVFR CIGS WILL LINGER ACROSS THE CWA THIS
EVENING AS WELL. ANOTHER SHORTWAVE FROM CANADA WILL DIG SEWD
ACROSS THE NORTHLAND LATE TONIGHT THROUGH WEDNESDAY. LIGHT TO
MODERATE SNOW WILL AFFECT AREAS ALONG THE CANADIAN BORDER...BUT
FROM THE IRON RANGE ON SOUTH...CONDITIONS SHOULD BE MAINLY DRY.
&&
.PREV DISCUSSION... /ISSUED 314 PM CST TUE DEC 11 2012/
SHORT TERM...THROUGH WEDNESDAY NIGHT.
LAKE EFFECT SNOW ALONG THE NORTH SHORE HAS DIMINISHED THIS
AFTERNOON AS WINDS HAVE TURNED MORE WESTERLY BEHIND THE DEPARTING
LOW. A LAKE BAND OF LIGHT SNOW SHOWERS ALSO EXTENDED FROM JUST OFF
SHORE OF DOUGLAS COUNTY...ALONG THE BAYFIELD PENINSULA TOWARD RED
CLIFF. THIS WILL LIKELY CONTINUE THROUGH MOST OF THE EVENING AS
THE LOW LEVEL FLOW REMAINS WEST-SOUTHWEST. FETCH WILL BE
LIMITED...AND THE NAM AND RUC BOTH SHOW LOWERING RH THROUGH THE
EVENING...SO WE THINK ACCUMULATIONS WILL BE LIMITED. PLENTY OF CLOUDS
REMAIN OVER THE REST OF THE NORTHLAND...WITH FLURRIES/LIGHT SNOW
STILL OCCURRING. A WEAK SHORTWAVE WAS MOVING THROUGH CENTRAL
MINNESOTA THIS AFTERNOON...WITH RADAR HIGHER RETURNS WELL SOUTH OF
THE CWA.
HIGH PRESSURE WILL MOVE QUICKLY THROUGH THE NORTHLAND
TONIGHT...WITH WAA INCREASING OVERNIGHT AHEAD OF AN AREA OF LOW
PRESSURE. WE HAVE A CHANCE FOR LIGHT SNOW LATER TONIGHT OVER
NORTHWEST AREAS...AND INCREASED POPS TO LIKELY BETWEEN 09-12Z OVER
KOOCHICHING COUNTY. THE WAA AND WEAK SHORT WAVE WILL CONTINUE TO
IMPACT FAR NORTHERN AREAS WEDNESDAY...AND WE HAVE INCREASED POPS
TO LIKELY AS ACCUMULATIONS UP TO TWO INCHES WILL BE POSSIBLE IN
SPOTS. THERE MAY ALSO BE A NARROW WINDOW FOR LAKE EFFECT SNOW
WEDNESDAY MORNING BETWEEN LITTLE MARAIS AND GRAND PORTAGE AGAIN.
FETCH BECOMES FAVORABLE WEDNESDAY MORNING...BUT WAA WILL CAUSE
850MB TEMPS TO RISE QUICKLY. WE`LL HAVE TO KEEP A CLOSE EYE ON
THAT AREA AS WE COULD GET A QUICK BURST OF SEVERAL INCHES OF SNOW
IF THE TEMPS ALOFT DON`T WARM AS FAST AS ANTICIPATED.
TEMPERATURES TONIGHT WILL BE A CHALLENGE...AS THEY WILL BE HIGHLY
DEPENDENT ON CLEARING. WE DID DROP THEM MOST AREAS...HAVE SOME
WELL BELOW ZERO OVER NORTHEAST MINNESOTA. EVENING SHIFT WILL HAVE
TO MONITOR CLOUD TRENDS CLOSELY...AS WE MAY NOT BE COLD ENOUGH IF
IT CLEARS LONGER THAN ANTICIPATED. HIGHS WEDNESDAY WILL BE WARMER
THAN TODAY...WITH SOME AREAS REACHING AROUND THIRTY OVER NORTHWEST
WISCONSIN.
CONFIDENCE WEDNESDAY NIGHT IS LOWER THAN AVERAGE REGARDING SNOW
POTENTIAL. NAM WAS SHOWING A WEAK CIRCULATION AT 850MB AND
FORECASTS SOME LIGHT SNOW OVER THE FAR NORTH. THE MODELS ARE NOT
IN VERY GOOD AGREEMENT DURING THIS PERIOD. WE KEPT A MENTION OF
LIGHT SNOW OVER THE NORTH...AND EXPANDED A BIT SOUTH OVER OUR
WESTERN COUNTIES. IF THE MODELS TREND TOWARD THE NAM...WE WILL
NEED HIGHER POPS FOR SOME LIGHT SNOW ACCUMULATIONS OVER THE WEST
AND NORTHERN CWA.
LONG TERM...THURSDAY - MONDAY.
THE NORTHLAND SHOULD FIND ITSELF THURSDAY MORNING WITH A STATIONARY
FRONT NEAR OR SOUTH OF THE FA. THERE MAY BE SOME LIGHT SNOW ACROSS
THE NORTHERN FA THURSDAY ASSOCIATED WITH PLENTIFUL LOW CLOUDS NORTH
OF THE FRONT. HIGH PRESSURE IN CANADA WILL BEGIN TO EXERT GREATER
INFLUENCE ON THE NORTHLAND THURSDAY NIGHT...PROVIDING DRY WEATHER
THROUGH FRIDAY NIGHT. THE MODELS ARE LATCHING ONTO A STRONG LOW
PRESSURE SYSTEM MOVING FROM THE CENTRAL PLAINS TO UPPER MIDWEST ON
SATURDAY. THIS SYSTEM COULD BRING SIGNIFICANT SNOWFALL TO PARTS OF
THE FA...ESPECIALLY THE SOUTHEASTERN FA WHICH WILL BE IN BETTER
PROXIMITY TO THE SYSTEM. TEMPERATURES THROUGH THE PERIOD SHOULD BE
NEAR OR SLIGHTLY ABOVE NORMAL.
AVIATION...18Z TAFS
IFR/MVFR CONDITIONS ACROSS NE MINNESOTA AND NW MINNESOTA ARE
EXPECTED TO CONTINUE THROUGH THIS AFTERNOON AND INTO EARLY THIS
EVENING. CIGS WILL LIKELY RANGE FROM 1500 TO 3000 FT...AND THE
-SN WILL OCCASIONALLY REDUCE VIS TO IFR. THE SNOW SHOULD BEGIN TO
SUBSIDE LATER THIS AFTERNOON. THE CLOUDS WILL BEGIN TO CLEAR AT
KINL BY MID AFTERNOON...AND THEN AT OTHER TERMINALS LATE THIS
AFTERNOON AND EARLY THIS EVENING. EXPECT THE 5 TO 10 KNOT W TO SW
WINDS TO BECOME S TO SE TONIGHT. KINL COULD SEE MVFR CIGS
REDEVELOP LATE TONIGHT AND TOMORROW MORNING...BUT VFR CONDITIONS
ARE LIKELY TO RETURN TO KDLH/KHIB/KBRD/KHYR TONIGHT.
&&
.POINT TEMPS/POPS...
DLH 3 28 20 29 / 10 10 10 20
INL -9 23 8 19 / 60 70 30 20
BRD -5 29 17 28 / 10 10 20 10
HYR 2 32 22 33 / 20 10 10 0
ASX 5 33 25 35 / 20 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CST THIS EVENING FOR LSZ140.
&&
$$
AVIATION...BERDES
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1119 PM CST SUN DEC 9 2012
.UPDATE...
ISSUED AT 844 PM CST SUN DEC 9 2012
GOING FORECAST STILL LOOKS GOOD. SCT -SHRA HAS MOVED OUT OF THE
CWA AS THE COLD FRONT CONTINUES TO MOVE SOUTHEAST. BACK EDGE OF
LOW CLOUDS ARE MOVING INTO WESTERN CWA WITH A SECOND AREA OF LOW
CLOUDS MOVING IN QUICKLY BEHIND IT. RAP PROGS IS SHOWING ABUNDANT
AMOUNT OF LOW LEVEL MOISTURE STAYING IN THE AREA THROUGH MIDDAY
TOMORROW KEEPING SKIES MOSTLY CLOUDY THROUGH TOMORROW MORNING.
BRITT
&&
.SHORT TERM...
ISSUED AT 221 PM CST SUN DEC 9 2012
(TONIGHT)
PRIMARY CONCERN FOR TONIGHT WILL BE PRECIP CHANCES AND TEMPERATURES
BEHIND THE STRONG COLD FRONT THAT IS MOVING THROUGH THE REGION. THE
INITIAL WIND SHIFT IS ALREADY THROUGH THE NORTHWESTERN 2/3 OF THE
CWFA. WIND SHIFT SHOULD BE ALL THE WAY THROUGH OUR SOUTHEAST BORDER
WITH WFO PAH BY 00Z. UNTIL THEN...EXPECTING A CONTINUING THREAT FOR
THUNDERSTORMS ACROSS SOUTHEAST MO/SOUTHWEST IL. THUNDER THREAT
SHOULD DIMINISH AFTER FROPA AND ONLY EXPECT SHOWERS DURING THE
EVENING. WIND WILL BE INCREASING THROUGH THE EVENING BEHIND THE
FRONT AND GUSTS IN EXCESS OF 25KTS ARE LIKELY GIVEN THE STRONG
PRESSURE GRADIENT AHEAD OF THE 1035MB HIGH BUILDING ACROSS THE
PLAINS. WITH LOWS IN THE TEENS AND 20S IN THE COLD SECTOR THIS
MORNING ACROSS NEBRASKA...MOS FORECAST LOWS FOR TONIGHT IN THE 20S
LOOK VERY REASONABLE...AND WOULD NOT BE SURPRISED TO SEE IT GET
COLDER IN SOME SPOTS. WIND CHILL VALUES WILL BE A SLAP IN THE FACE
TOMORROW MORNING AFTER ALL THE MILD WEATHER WE`VE BEEN HAVING.
EXPECT READINGS IN THE SINGLE DIGITS TO MID TEENS.
CARNEY
&&
.LONG TERM...
ISSUED AT 221 PM CST SUN DEC 9 2012
(MONDAY AND MONDAY NIGHT)
EXPECT A COLD AND WINDY DAY WITH TEMPERATURES STRUGGLING TO RISE
BACK TO THE FREEZING MARK. IN FACT...LOOKING AT THE AIR MOVING IN
FROM THE NORTHWEST...MY FORECAST MAY STILL BE TOO WARM. WENT ON
COLDER SIDE OF GUIDANCE FOR MONDAY NIGHT AS RIDGE CENTER PROGRESSES
ACROSS THE CWA.
(TUESDAY THRU THURSDAY)
UPPER FLOW BECOMES MORE ZONAL DURING THIS PERIOD WITH A SHORTWAVE
PASSING TO OUR SOUTH ON WEDNESDAY. TEMPERATURES WILL MODERATE BACK
TO AND ABOVE NORMAL AS DRY WEATHER AND SOUTHWEST SURFACE WINDS ARE
ANTICIPATED.
(FRIDAY THRU SUNDAY)
UPPER FLOW WILL BECOME SOUTHWESTERLY BY WEEKS END AS A DEEP TROF
DIGS ACROSS THE WEST COAST. EVENTUALLY THIS TROF/LOW WILL CROSS THE
FOUR CORNERS REGION AND EJECT INTO THE PLAINS...WITH LEE
CYCLOGENESIS OCCURRING FRIDAY/FRIDAY NIGHT IN THE CENTRAL PLAINS.
HAVE IGNORED THE 12Z OPERATIONAL GFS AS IT DEAMPLIFIES THIS WAVE AS
IT MOVES EAST...TAKING THE SURFACE LOW DIRECTLY EAST WHICH SEEMS
UNREALISTIC AND INCONSISTENT WHEN COMPARED TO PREVIOUS RUNS AND
ENSEMBLE FORECASTS.
THE MORE CONSISTENT ECWMF MODEL SPINS THE SURFACE LOW UP ACROSS
SOUTHWEST KANSAS AND LIFTS IT NORTHEAST ACROSS NORTHWEST MISSOURI
...EASTERN IOWA...TOWARD THE WESTERN GREAT LAKES REGION. THIS PLACES
THE ENTIRE CWA IN THE WARM SECTOR OF THIS SYSTEM AND AM EXPECTING
ENOUGH RETURN FLOW FROM THE SOUTH FOR THUNDERSTORMS TO BE LIKELY
WITH THIS SYSTEM.
AIR BEHIND THIS SYSTEM APPEARS TO BE MORE PACIFIC...THAN
CANADIAN...SO ABOVE NORMAL TEMPERATURES SHOULD CONTINUE ON SUNDAY.
CVKING
&&
.AVIATION...
ISSUED AT 1045 PM CST SUN DEC 9 2012
COLD FRONT HAS MOVED WELL SE OF THE TAF SITES ALONG WITH
ACCOMPANYING SHOWERS. NWLY SFC WINDS...GUSTY AT TIMES WILL
CONTINUE AT THE TAF SITES DUE TO A TIGHT SFC PRESSURE GRADIENT
BETWEEN THE STRONG SFC RIDGE OVER THE PLAINS AND THE SFC LOW OVER
THE OHIO VALLEY REGION. THESE RELATIVELY STRONG AND GUSTY NWLY SFC
WINDS WILL CONTINUE ON MON...THEN DIMINISH MON EVNG AS THE SFC
RIDGE AXIS APPROACHES THE TAF SITES. GETTING SOME CLEAR AREAS OR
SLOTS IN THE LOW LEVEL CLOUD DECK BETWEEN STL AND COU WITH MORE
WIDESPREAD OVERCAST CLOUD DECK ACROSS NRN MO. ACTUAL CLEARING LINE
OF LOW LEVEL CLOUDS STILL BACK W ACROSS ERN PORTIONS OF NEBRASKA
AND CNTRL KANSAS. THERE MAY BE BRIEF PERIODS OF VFR CONDITIONS
LATE TGT AND MON MRNG FROM COU TO THE ST LOUIS METRO AREA...BUT
THE MAJORITY OF THE TIME AN MVFR CLOUD CEILNG SHOULD CONTINUE
AROUND 2000 FT IN UIN AND 2000-3000 FT FROM COU TO THE ST LOUIS
METRO AREA. THE CLOUD CEILING SHOULD SCATTER OUT BY 18Z MON IN
COU AND AROUND 21Z MON AT THE OTHER TAF SITES AS THE ENTIRE LOW
LEVEL CLOUD FIELD FINALLY ADVECTS E OF THE TAF SITES.
SPECIFICS FOR KSTL...THE SKY COVER HAS RECENTLY GONE SCATTERED...BUT
THIS SHOULD BE SHORT LIVED AS MORE LOW LEVEL CLOUDS HAVE DROPPED
SEWD INTO CNTRL MO WHICH SHOULD IMPACT STL LATE TGT. WILL KEEP AN
MVFR CIG FORECAST IN THE STL TAF AROUND 2000-3000 FT LATE TGT AND
MUCH OF MON AS THE SATELLITE LOOP SHOWS MORE MVFR CLOUD CIGS
DROPPING SEWD TOWARDS STL AND THE MODELS DEPICT HIGH RELATIVE
HUMIDITY VALUES AROUND 2000-4000 FT LATE TGT UNTIL EARLY MON AFTN.
THE MVFR CLOUD DECK SHOULD SCATTER OUT LATE MON AFTN...AND FINALLY
GO CLEAR BY MON EVNG...WHILE THE RELATIVELY STRONG AND GUSTY NWLY
SFC WIND DIMINISHES MON EVNG AS THE SFC PRESSURE GRADIENT
RELAXES...AND THEN BECOMES LIGHT LATE MON NGT.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
156 AM EST MON DEC 10 2012
.SYNOPSIS...
PERIODS OF RAIN CAN BE EXPECTED ACROSS THE AREA THROUGH MONDAY AS
A SLOW MOVING COLD FRONT TRACKS EAST ACROSS THE AREA. THE
PRECIPITATION COULD END AS A BRIEF PERIOD OF SNOW SHOWERS MONDAY
NIGHT AS COLD AIR MOVES IN. TUESDAY WILL BE MOSTLY DRY AND CHILLY
AS HIGH PRESSURE BUILDS ACROSS THE AREA. WARMER AND CONTINUED DRY
WEATHER CAN BE EXPECTED WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...QUICK UPDATE TO RMV CATEGORICAL POPS ACRS NEPA
DROPPING THEM DOWN TO THE LKLY RANGE. MAIN SLUG OF RAIN IS RIDING
NORTHEASTWARD INTO WRN NY AT THIS TIME WITH ONLY SCATTERED SHOWERS
ACRS CNTRL PA. STRONGEST H8 WINDS APPEAR TO BE FOCUSED OVR THE WRN
ZONES FOR THE NEXT 3 HRS AND LIFT FM THIS WAA AREA AND STRONG
ISENTROPIC UPGLIDE. THUS, HV INCRSD QPF AMNTS ACRS WRN AND NRN
SXNS.
APPEARS AS THO THREAT FOR FRZG RAIN HAS ENDED WITH NO MESONETS
RMNG BLO FRZG IN THE CWA. EVEN ROAD TEMPS HV WARMED ABV FREEZING.
SLUG OF RAIN THAT INITIALLY MVD INTO THE CATSKILLS ACTUALLY WARMED
TEMPS, DRAGGING WARM AIR DOWN FM ALOFT. THUS, OUTSIDE OF ANY BRIDGES
OR OVERPASSES ACRS THE CATSKILLS AND MOHAWK VLY ROAD SFCS SHOULD
NOT BCM SLICK OVRNGT.
PREVIOUS DISCUSSIONS BELOW...
10 PM UPDATE...JUST TWEAKED GRIDS SOME. DECIDED TO WIND DOWN POPS
FOR A FEW HOURS BETWEEN FIRST SHRT WAVE PASSING BY AT PRESENT AND
THEN NEXT ONE WHICH IS MOVING TWD PA. PRECIPITATION ECHOES WINDING
DOWN ON KBGM RADAR AS THEY ARE BEGINNING TO INCREASE IN SRN PA ON
THE KCCX RADAR. SO WILL BRING POPS BACK UP WITH THE ARRIVAL OF
THIS NEXT WAVE AND PRECIP FROM PA LATE TONIGHT. AS FOR PRECIP
TYPE... KTYX RADAR DUAL POLAR PRODUCTS SUGGEST A MELTING LAYER
ARND 4800 FEET IN NRN ONEIDA COUNTY. SURFACE MESONETS SHOW
TEMPERATURES A LITTLE ABV FREEZING SUGGESTING JUST PLAIN RAIN UP
THERE. HAVE AN SPS THAT WILL EXPIRE AT 11 PM FOR POTENTIAL FOR
FZRA AT THE ONSET OF THE PRECIP. WILL LET THIS EXPIRE. NRN ONEIDA
WILL SEE RAIN THRU THE NIGHT AS TEMPS CLIMB WITH CONTINUED WARMING
ALOFT. ALSO MESONETS IN THE CATSKILLS SHOW TEMPS ABV FRZG. AS THE
TEMPERATURES AT 850 MB ROCKET UP TO +5C OR SO...TEMPS WILL CONT TO
SLOWLY WARM OVERNIGHT.
BIG CHANGE FOR MONDAY WAS TO DROP POPS TO CHC-SLGHT CHC IN THE AM
HOURS AS ALL CONVECTION ALLOWING MODELS AND OTHER HI RES MODELS
SHOW LITTLE PRECIP AT ALL UNTIL CD FRNT APPROACHES IN THE
AFTERNOON. SO WILL BEGIN THE DAY WITH JUST ISLD-SCT SHRA AT BEST...AND
RAMP UP POPS TO CAT IN THE AFTERNOON.
7 PM UPDATE...ISSUED A SPECIAL WEATHER STATEMENT FOR THE WESTERN
CATSKILLS AND NORTHERN ONEIDA COUNTY FOR A BRIEF PERIOD OF
FREEZING RAIN. RAIN WILL OVERSPREAD THE REGION QUICKLY BY 3-4Z AS
A STRONG SHOT OF LOW-LEVEL MOISTURE ADVECTION AND ISENTROPIC
LIFT/WAA RAPIDLY LEADS TO WIDESPREAD LIGHT RAINS OVER THE AREA. A
FEW HIGHER TERRAIN SPOTS IN THE CATSKILLS AND FAR NORTHEAST ONEIDA
COUNTY COULD BEGIN AS A PERIOD OF FREEZING RAIN AS TEMPERATURES
LIKELY ARE CLOSE TO FREEZING IN THESE AREAS. IT WILL BE VERY
SPOTTY SO NO FZRA ADVY. DUE TO THE STRONG ISENTROPIC LIFT/WARM AIR
ADVECTION...TEMPERATURES SOAR TO 3-7C AT 850 MB BY 6Z AS PER
GFS...WITH SIMILAR TEMPERATURES ON THE NAM...CMC...RAP...AND LOCAL
WRF. THIS WARMING SHUD ALLOW TEMPERATURES TO CLIMB TO THE MID TO
UPPER 30S OR EVEN LOW 40S OVERNIGHT AS THE RAIN FALLS.
FIRST SHOT OF RAIN LIKELY WILL MOVE QUICKLY THRU C NY AND NE PA BY
6-7Z WITH THE NEXT SHOT RAPIDLY APPROACHING ARND 9Z-10Z OR SO AS
ANOTHER LOW-LEVEL JET AND ASSOCIATED MOISTURE ADVECTION AND
ENHANCED ISENTROPIC LIFT APPROACHES. THE WATER VAPOR SATELLITE
IMAGERY SHOWS THESE TWO LOWER-LEVEL WAVES WELL IN THE UPPER LEVEL
MOIST PLUMES...ONE NORTH OF NY AND THE OTHER ACRS THE OH VLLY TO
MID ATLANTIC. THE MODELS HAVE TWO DISTINCT LOW-LEVEL JETS AT 850
MB WHICH ARE TIED TO EACH OF THESE SHORT WAVES. HENCE PRECIP
INCREASES AGAIN LATE TONIGHT WITH NEXT WAVE. .
THEN FOR MONDAY MORNING AFTER THE SECOND WAVE...I SEE A BREAK IN
THE PRECIPITATION BEFORE THE RAIN SHOWERS MOVE THRU THE REGION
ALONG A COLD FRONT WHICH SWINGS THRU IN THE AFTERNOON. THE HIGH
RES WRF ARW AND WRF NMM...LOCAL WRF...RAP AND NAM 4KM ALL SHOW
LITTLE PRECIP MONDAY AM WITH PRECIP INCREASING AGAIN IN THE PM. FOR
NOW DO NOT HAVE THUNDER IN GRIDS FOR MONDAY AFTERNOON...BUT NAM
AND RAP SHOWALTERS ARE SLIGHT NEGATIVE...LOCAL WRF AND GFS ARE
SLIGHTLY POSITIVE. THE HI RES CONVECTION ALLOWING MODELS ALL SHOW
SOME SORT OF LINE OF HEAVIER SHRA ALONG THE COLD FRONT MON PM. SO
I TRENDED POPS DOWNWARD MONDAY AM...THEN INCREASED THEM IN THE
AFTERNOON TO ACCOUNT FOR CD FRONTAL SHRA ACVTY. WILL PASS ON IDEA
OF POSSIBLE THUNDER TO MID SHIFT WHICH WILL HAVE THE NEW 00Z
GUIDC TO LOOK AT.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
COLD FRONT APPROACHES THE AREA ON MONDAY. WITH SURFACE LOW
PRESSURE TRACKING UP THE ST LAWRENCE VALLEY OUR AREA WILL BE IN
THE WARM SECTOR MONDAY WITH STEADIER RAIN PULLING OFF TO THE NORTH
AND EAST FOR AWHILE MONDAY MORNING INTO THE AFTERNOON. BASED ON
THIS EXPECT RAIN TO TAPER TO SHOWERS ESPECIALLY OVER NORTHEAST PA.
TEMPERATURES WILL CLIMB WELL INTO THE 50S.
COLD FRONT CROSS THE AREA STARTING AROUND 18Z OVER STEUBEN
COUNTY... AND AROUND 00Z OVER NORTHEAST PA. THIS WILL BE
ACCOMPANIED BY AND FOLLOWED BY A PERIOD OF HEAVIER RAIN. THE RAIN
MAY CHANGE TO A PERIOD OF LIGHT SNOW OVER CENTRAL NY AFTER OOZ AS
WEAK WAVES OF LOW PRESSURE MOVING NORTHEAST ALONG THE FRONT MAY
KEEP THE PRECIPITATION GOING FOR AWHILE MONDAY EVENING IN THE COLD
AIR. TEMPERATURES BRIEFLY COOL TO AROUND -10 AT 850 MB WHICH WILL
BE ENOUGH FOR A BRIEF LAKE RESPONSE LATER MONDAY NIGHT NW FLOW AND
SOME SNOW SHOWERS SOUTHEAST OF LAKE ONTARIO. OVERALL
ACCUMULATIONS OF SNOW MONDAY NIGHT SHOULD BE LESS THAN 2 INCHES.
HIGH PRESSURE MOVES ACROSS THE AREA ON TUESDAY WITH DRY WEATHER
AND SEASONABLY COLD TEMPERATURES. WARMING TREND BEGINS ON
WEDNESDAY AS THE HIGH MOVES OFF TO THE EAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
2 AM UPDATE...
NO SIGNIFICANT CHANGES REQUIRED TO THE EXTENDED AS PREVIOUS FCST
REMAINS IN EXCELLENT SHAPE. A VERY BENIGN PERIOD EXPECTED THROUGH
LATE WEEK AS HIGH PRESSURE REMAINS IN CONTROL OF THE WX PATTERN.
WEAK UPPER RIDGING ALOFT COMBINED WITH THE RETURN OF SOUTHERLY
FLOW AHEAD OF NEXT WEEKEND/S STORM SYSTEM WILL ALLOW FOR ABOVE
AVERAGE TEMPS BOTH THU AND FRI WITH HIGHS TOPPING OUT IN THE
MIDDLE TO UPPER 40S. AFOREMENTIONED SYSTEM EXPECTED TO BEGIN
IMPACTING THE AREA ON SAT WITH SCATTERED RA SHWRS INCREASING BY
MID/LATE AFTERNOON. SOME DISAGREEMENT REMAINS BETWEEN THE GFS AND
THE ECMWF WITH THE LATTER SHOWING A SLOWER AND WARMER SOLUTION
TOWARDS THE END OF THE WEEKEND AS BLOCKING HIGH PRESSURE REMAINS
ENTRENCHED ACROSS EASTERN CANADA. THE GFS ON THE OTHER HAND
ADVERTISES MUCH COOLER AIR FILTERING IN BY SUN WITH LAKE EFFECT
SNOWS POTENTIALLY REDEVELOPING AS COLD AIR FLOWS OVER THE WARMER
WATER OF LAKE ONTARIO. FOR NOW...HAVE DECIDED TO LEAVE WELL ENOUGH
ALONE UNTIL MODEL AGREEMENT BECOME BETTER ESTABLISHED.
PREVIOUS LONG TERM DISCUSSION...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THE EXTENDED
INDICATING SURFACE HIGH PRESSURE WILL PROVIDE DRY AND MILD
CONDITIONS THROUGH FRIDAY. LATE IN THE PERIOD LOW PRES IS FORECAST
TO TRACK FROM THE MID WEST NORTHEAST INTO THE UPPER GREAT LAKES
THEN ACROSS EASTERN CANADA. THE ECMWF IS SLOWER AND FARTHER WEST
WITH THIS SYSTEM THAN THE GFS. WILL CONTINUE WITH CHC POPS
SATURDAY THROUGH SUNDAY WITH PRECIP TYPE A RAIN/SNOW MIX CHANGING
TO ALL RAIN BY SUNDAY AS TEMPS WARM INTO THE LOWER/MIDDLE 40S.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
WIDESPREAD MVFR AND IFR CONDITIONS EXPECTED THROUGH THE DAY TODAY AS
A SERIES OF UPPER DISTURBANCES AND APPROACHING COLD FRONT CONTINUE
TO IMPACT THE AREA. LATEST UPSTREAM RADAR TRENDS SHOWING PRECIP
ASSOCIATED WITH THE NEXT APPROACHING UPPER WAVE OF ENERGY RAPIDLY
APPROACHING THE REGION. THAT SAID...EXPECT -RA TO CONTINUE THROUGH THE
OVERNIGHT HRS AT ALL TERMINALS HOWEVER STRONG WIND FIELDS ALOFT
WILL ONLY PRODUCE LIMITED MVFR VSBY RESTRICTIONS. WE CURRENTLY
EXPECT CONTINUED IFR CIGS AT BOTH ITH AND BGM...WHERE BOTH SITES
WILL SEE CIGS BELOW ALTERNATE MINS. AT ELM...WE EXPECT CIGS TO
EVENTUALLY GO DOWN AFTER 08Z WHICH WILL RESIDE BELOW IFR
THRESHOLDS FOR THE AIRFIELD. ELSEWHERE...MOSTLY MVFR CIGS ARE
EXPECTED WITH HEIGHTS HANGING IN THE 1000-1500 FT RANGE. THE
OTHER MAIN IMPACT OVERNIGHT WILL BE STRONG WINDS ALOFT AND LIKELY
LLWS CONDITIONS AT BOTH ELM AND AVP WHERE CALM WINDS ALONG THE
SFC WILL RAPIDLY INCREASE WITH HEIGHT. WIND SHEAR CONCERNS WILL
COME TO AN END BY 15Z AT BOTH SITES AS STRONG LOW-LEVEL JET CORE
EXITS STAGE RIGHT.
BEYOND 12Z...A TEMPORARY LULL IS EXPECTED WITH ONLY SOME -DZ OR
-SHRA HANGING AROUND. AFTER 18Z...MORE PRONOUNCED RA ACTIVITY WILL
BEGIN MOVING INTO THE AREA AS NEXT UPPER WAVE AND SFC COLD FRONT
TRAVERSE THE REGION. BEYOND COLD FRONTAL PASSAGE...MUCH COOLER AIR
WILL BEGIN MOVING INTO THE REGION WHICH MAY LEAD TO RAIN MIXING
WITH SNOW AFTER 00Z THIS EVENING.
OUTLOOK...
TUE...PATCHY MVFR...MAINLY ACRS CNTRL NY.
TUE NGT-FRI...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...DJN/PVN
SHORT TERM...MSE
LONG TERM...CMG/RRM
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1254 AM EST MON DEC 10 2012
.SYNOPSIS...
PERIODS OF RAIN CAN BE EXPECTED ACROSS THE AREA THROUGH MONDAY AS
A SLOW MOVING COLD FRONT TRACKS EAST ACROSS THE AREA. THE
PRECIPITATION COULD END AS A BRIEF PERIOD OF SNOW SHOWERS MONDAY
NIGHT AS COLD AIR MOVES IN. TUESDAY WILL BE MOSTLY DRY AND CHILLY
AS HIGH PRESSURE BUILDS ACROSS THE AREA. WARMER AND CONTINUED DRY
WEATHER CAN BE EXPECTED WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...QUICK UPDATE TO RMV CATEGORICAL POPS ACRS NEPA
DROPPING THEM DOWN TO THE LKLY RANGE. MAIN SLUG OF RAIN IS RIDING
NORTHEASTWARD INTO WRN NY AT THIS TIME WITH ONLY SCATTERED SHOWERS
ACRS CNTRL PA. STRONGEST H8 WINDS APPEAR TO BE FOCUSED OVR THE WRN
ZONES FOR THE NEXT 3 HRS AND LIFT FM THIS WAA AREA AND STRONG
ISENTROPIC UPGLIDE. THUS, HV INCRSD QPF AMNTS ACRS WRN AND NRN
SXNS.
APPEARS AS THO THREAT FOR FRZG RAIN HAS ENDED WITH NO MESONETS
RMNG BLO FRZG IN THE CWA. EVEN ROAD TEMPS HV WARMED ABV FREEZING.
SLUG OF RAIN THAT INITIALLY MVD INTO THE CATSKILLS ACTUALLY WARMED
TEMPS, DRAGGING WARM AIR DOWN FM ALOFT. THUS, OUTSIDE OF ANY BRIDGES
OR OVERPASSES ACRS THE CATSKILLS AND MOHAWK VLY ROAD SFCS SHOULD
NOT BCM SLICK OVRNGT.
PREVIOUS DISCUSSIONS BELOW...
10 PM UPDATE...JUST TWEAKED GRIDS SOME. DECIDED TO WIND DOWN POPS
FOR A FEW HOURS BETWEEN FIRST SHRT WAVE PASSING BY AT PRESENT AND
THEN NEXT ONE WHICH IS MOVING TWD PA. PRECIPITATION ECHOES WINDING
DOWN ON KBGM RADAR AS THEY ARE BEGINNING TO INCREASE IN SRN PA ON
THE KCCX RADAR. SO WILL BRING POPS BACK UP WITH THE ARRIVAL OF
THIS NEXT WAVE AND PRECIP FROM PA LATE TONIGHT. AS FOR PRECIP
TYPE... KTYX RADAR DUAL POLAR PRODUCTS SUGGEST A MELTING LAYER
ARND 4800 FEET IN NRN ONEIDA COUNTY. SURFACE MESONETS SHOW
TEMPERATURES A LITTLE ABV FREEZING SUGGESTING JUST PLAIN RAIN UP
THERE. HAVE AN SPS THAT WILL EXPIRE AT 11 PM FOR POTENTIAL FOR
FZRA AT THE ONSET OF THE PRECIP. WILL LET THIS EXPIRE. NRN ONEIDA
WILL SEE RAIN THRU THE NIGHT AS TEMPS CLIMB WITH CONTINUED WARMING
ALOFT. ALSO MESONETS IN THE CATSKILLS SHOW TEMPS ABV FRZG. AS THE
TEMPERATURES AT 850 MB ROCKET UP TO +5C OR SO...TEMPS WILL CONT TO
SLOWLY WARM OVERNIGHT.
BIG CHANGE FOR MONDAY WAS TO DROP POPS TO CHC-SLGHT CHC IN THE AM
HOURS AS ALL CONVECTION ALLOWING MODELS AND OTHER HI RES MODELS
SHOW LITTLE PRECIP AT ALL UNTIL CD FRNT APPROACHES IN THE
AFTERNOON. SO WILL BEGIN THE DAY WITH JUST ISLD-SCT SHRA AT BEST...AND
RAMP UP POPS TO CAT IN THE AFTERNOON.
7 PM UPDATE...ISSUED A SPECIAL WEATHER STATEMENT FOR THE WESTERN
CATSKILLS AND NORTHERN ONEIDA COUNTY FOR A BRIEF PERIOD OF
FREEZING RAIN. RAIN WILL OVERSPREAD THE REGION QUICKLY BY 3-4Z AS
A STRONG SHOT OF LOW-LEVEL MOISTURE ADVECTION AND ISENTROPIC
LIFT/WAA RAPIDLY LEADS TO WIDESPREAD LIGHT RAINS OVER THE AREA. A
FEW HIGHER TERRAIN SPOTS IN THE CATSKILLS AND FAR NORTHEAST ONEIDA
COUNTY COULD BEGIN AS A PERIOD OF FREEZING RAIN AS TEMPERATURES
LIKELY ARE CLOSE TO FREEZING IN THESE AREAS. IT WILL BE VERY
SPOTTY SO NO FZRA ADVY. DUE TO THE STRONG ISENTROPIC LIFT/WARM AIR
ADVECTION...TEMPERATURES SOAR TO 3-7C AT 850 MB BY 6Z AS PER
GFS...WITH SIMILAR TEMPERATURES ON THE NAM...CMC...RAP...AND LOCAL
WRF. THIS WARMING SHUD ALLOW TEMPERATURES TO CLIMB TO THE MID TO
UPPER 30S OR EVEN LOW 40S OVERNIGHT AS THE RAIN FALLS.
FIRST SHOT OF RAIN LIKELY WILL MOVE QUICKLY THRU C NY AND NE PA BY
6-7Z WITH THE NEXT SHOT RAPIDLY APPROACHING ARND 9Z-10Z OR SO AS
ANOTHER LOW-LEVEL JET AND ASSOCIATED MOISTURE ADVECTION AND
ENHANCED ISENTROPIC LIFT APPROACHES. THE WATER VAPOR SATELLITE
IMAGERY SHOWS THESE TWO LOWER-LEVEL WAVES WELL IN THE UPPER LEVEL
MOIST PLUMES...ONE NORTH OF NY AND THE OTHER ACRS THE OH VLLY TO
MID ATLANTIC. THE MODELS HAVE TWO DISTINCT LOW-LEVEL JETS AT 850
MB WHICH ARE TIED TO EACH OF THESE SHORT WAVES. HENCE PRECIP
INCREASES AGAIN LATE TONIGHT WITH NEXT WAVE. .
THEN FOR MONDAY MORNING AFTER THE SECOND WAVE...I SEE A BREAK IN
THE PRECIPITATION BEFORE THE RAIN SHOWERS MOVE THRU THE REGION
ALONG A COLD FRONT WHICH SWINGS THRU IN THE AFTERNOON. THE HIGH
RES WRF ARW AND WRF NMM...LOCAL WRF...RAP AND NAM 4KM ALL SHOW
LITTLE PRECIP MONDAY AM WITH PRECIP INCREASING AGAIN IN THE PM. FOR
NOW DO NOT HAVE THUNDER IN GRIDS FOR MONDAY AFTERNOON...BUT NAM
AND RAP SHOWALTERS ARE SLIGHT NEGATIVE...LOCAL WRF AND GFS ARE
SLIGHTLY POSITIVE. THE HI RES CONVECTION ALLOWING MODELS ALL SHOW
SOME SORT OF LINE OF HEAVIER SHRA ALONG THE COLD FRONT MON PM. SO
I TRENDED POPS DOWNWARD MONDAY AM...THEN INCREASED THEM IN THE
AFTERNOON TO ACCOUNT FOR CD FRONTAL SHRA ACVTY. WILL PASS ON IDEA
OF POSSIBLE THUNDER TO MID SHIFT WHICH WILL HAVE THE NEW 00Z
GUIDC TO LOOK AT.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
COLD FRONT APPROACHES THE AREA ON MONDAY. WITH SURFACE LOW
PRESSURE TRACKING UP THE ST LAWRENCE VALLEY OUR AREA WILL BE IN
THE WARM SECTOR MONDAY WITH STEADIER RAIN PULLING OFF TO THE NORTH
AND EAST FOR AWHILE MONDAY MORNING INTO THE AFTERNOON. BASED ON
THIS EXPECT RAIN TO TAPER TO SHOWERS ESPECIALLY OVER NORTHEAST PA.
TEMPERATURES WILL CLIMB WELL INTO THE 50S.
COLD FRONT CROSS THE AREA STARTING AROUND 18Z OVER STEUBEN
COUNTY... AND AROUND 00Z OVER NORTHEAST PA. THIS WILL BE
ACCOMPANIED BY AND FOLLOWED BY A PERIOD OF HEAVIER RAIN. THE RAIN
MAY CHANGE TO A PERIOD OF LIGHT SNOW OVER CENTRAL NY AFTER OOZ AS
WEAK WAVES OF LOW PRESSURE MOVING NORTHEAST ALONG THE FRONT MAY
KEEP THE PRECIPITATION GOING FOR AWHILE MONDAY EVENING IN THE COLD
AIR. TEMPERATURES BRIEFLY COOL TO AROUND -10 AT 850 MB WHICH WILL
BE ENOUGH FOR A BRIEF LAKE RESPONSE LATER MONDAY NIGHT NW FLOW AND
SOME SNOW SHOWERS SOUTHEAST OF LAKE ONTARIO. OVERALL
ACCUMULATIONS OF SNOW MONDAY NIGHT SHOULD BE LESS THAN 2 INCHES.
HIGH PRESSURE MOVES ACROSS THE AREA ON TUESDAY WITH DRY WEATHER
AND SEASONABLY COLD TEMPERATURES. WARMING TREND BEGINS ON
WEDNESDAY AS THE HIGH MOVES OFF TO THE EAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THE EXTENDED
INDICATING SURFACE HIGH PRESSURE WILL PROVIDE DRY AND MILD
CONDITIONS THROUGH FRIDAY. LATE IN THE PERIOD LOW PRES IS FORECAST
TO TRACK FROM THE MID WEST NORTHEAST INTO THE UPPER GREAT LAKES
THEN ACROSS EASTERN CANADA. THE ECMWF IS SLOWER AND FARTHER WEST
WITH THIS SYSTEM THAN THE GFS. WILL CONTINUE WITH CHC POPS
SATURDAY THROUGH SUNDAY WITH PRECIP TYPE A RAIN/SNOW MIX CHANGING
TO ALL RAIN BY SUNDAY AS TEMPS WARM INTO THE LOWER/MIDDLE 40S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
WIDESPREAD MVFR AND IFR CONDITIONS EXPECTED THROUGH THE DAY TODAY AS
A SERIES OF UPPER DISTURBANCES AND APPROACHING COLD FRONT CONTINUE
TO IMPACT THE AREA. LATEST UPSTREAM RADAR TRENDS SHOWING PRECIP
ASSOCIATED WITH THE NEXT APPROACHING UPPER WAVE OF ENERGY RAPIDLY
APPROACHING THE REGION. THAT SAID...EXPECT -RA TO CONTINUE THROUGH THE
OVERNIGHT HRS AT ALL TERMINALS HOWEVER STRONG WIND FIELDS ALOFT
WILL ONLY PRODUCE LIMITED MVFR VSBY RESTRICTIONS. WE CURRENTLY
EXPECT CONTINUED IFR CIGS AT BOTH ITH AND BGM...WHERE BOTH SITES
WILL SEE CIGS BELOW ALTERNATE MINS. AT ELM...WE EXPECT CIGS TO
EVENTUALLY GO DOWN AFTER 08Z WHICH WILL RESIDE BELOW IFR
THRESHOLDS FOR THE AIRFIELD. ELSEWHERE...MOSTLY MVFR CIGS ARE
EXPECTED WITH HEIGHTS HANGING IN THE 1000-1500 FT RANGE. THE
OTHER MAIN IMPACT OVERNIGHT WILL BE STRONG WINDS ALOFT AND LIKELY
LLWS CONDITIONS AT BOTH ELM AND AVP WHERE CALM WINDS ALONG THE
SFC WILL RAPIDLY INCREASE WITH HEIGHT. WIND SHEAR CONCERNS WILL
COME TO AN END BY 15Z AT BOTH SITES AS STRONG LOW-LEVEL JET CORE
EXITS STAGE RIGHT.
BEYOND 12Z...A TEMPORARY LULL IS EXPECTED WITH ONLY SOME -DZ OR
-SHRA HANGING AROUND. AFTER 18Z...MORE PRONOUNCED RA ACTIVITY WILL
BEGIN MOVING INTO THE AREA AS NEXT UPPER WAVE AND SFC COLD FRONT
TRAVERSE THE REGION. BEYOND COLD FRONTAL PASSAGE...MUCH COOLER AIR
WILL BEGIN MOVING INTO THE REGION WHICH MAY LEAD TO RAIN MIXING
WITH SNOW AFTER 00Z THIS EVENING.
OUTLOOK...
TUE...PATCHY MVFR...MAINLY ACRS CNTRL NY.
TUE NGT-FRI...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...DJN/PVN
SHORT TERM...MSE
LONG TERM...RRM
AVIATION...CMG
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1243 AM EST MON DEC 10 2012
.SYNOPSIS...
PERIODS OF RAIN CAN BE EXPECTED ACROSS THE AREA THROUGH MONDAY AS
A SLOW MOVING COLD FRONT TRACKS EAST ACROSS THE AREA. THE
PRECIPITATION COULD END AS A BRIEF PERIOD OF SNOW SHOWERS MONDAY
NIGHT AS COLD AIR MOVES IN. TUESDAY WILL BE MOSTLY DRY AND CHILLY
AS HIGH PRESSURE BUILDS ACROSS THE AREA. WARMER AND CONTINUED DRY
WEATHER CAN BE EXPECTED WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...QUICK UPDATE TO RMV CATEGORICAL POPS ACRS NEPA
DROPPING THEM DOWN TO THE LKLY RANGE. MAIN SLUG OF RAIN IS RIDING
NORTHEASTWARD INTO WRN NY AT THIS TIME WITH ONLY SCATTERED SHOWERS
ACRS CNTRL PA. STRONGEST H8 WINDS APPEAR TO BE FOCUSED OVR THE WRN
ZONES FOR THE NEXT 3 HRS AND LIFT FM THIS WAA AREA AND STRONG
ISENTROPIC UPGLIDE. THUS, HV INCRSD QPF AMNTS ACRS WRN AND NRN
SXNS.
APPEARS AS THO THREAT FOR FRZG RAIN HAS ENDED WITH NO MESONETS
RMNG BLO FRZG IN THE CWA. EVEN ROAD TEMPS HV WARMED ABV FREEZING.
SLUG OF RAIN THAT INITIALLY MVD INTO THE CATSKILLS ACTUALLY WARMED
TEMPS, DRAGGING WARM AIR DOWN FM ALOFT. THUS, OUTSIDE OF ANY BRIDGES
OR OVERPASSES ACRS THE CATSKILLS AND MOHAWK VLY ROAD SFCS SHOULD
NOT BCM SLICK OVRNGT.
PREVIOUS DISCUSSIONS BELOW...
10 PM UPDATE...JUST TWEAKED GRIDS SOME. DECIDED TO WIND DOWN POPS
FOR A FEW HOURS BETWEEN FIRST SHRT WAVE PASSING BY AT PRESENT AND
THEN NEXT ONE WHICH IS MOVING TWD PA. PRECIPITATION ECHOES WINDING
DOWN ON KBGM RADAR AS THEY ARE BEGINNING TO INCREASE IN SRN PA ON
THE KCCX RADAR. SO WILL BRING POPS BACK UP WITH THE ARRIVAL OF
THIS NEXT WAVE AND PRECIP FROM PA LATE TONIGHT. AS FOR PRECIP
TYPE... KTYX RADAR DUAL POLAR PRODUCTS SUGGEST A MELTING LAYER
ARND 4800 FEET IN NRN ONEIDA COUNTY. SURFACE MESONETS SHOW
TEMPERATURES A LITTLE ABV FREEZING SUGGESTING JUST PLAIN RAIN UP
THERE. HAVE AN SPS THAT WILL EXPIRE AT 11 PM FOR POTENTIAL FOR
FZRA AT THE ONSET OF THE PRECIP. WILL LET THIS EXPIRE. NRN ONEIDA
WILL SEE RAIN THRU THE NIGHT AS TEMPS CLIMB WITH CONTINUED WARMING
ALOFT. ALSO MESONETS IN THE CATSKILLS SHOW TEMPS ABV FRZG. AS THE
TEMPERATURES AT 850 MB ROCKET UP TO +5C OR SO...TEMPS WILL CONT TO
SLOWLY WARM OVERNIGHT.
BIG CHANGE FOR MONDAY WAS TO DROP POPS TO CHC-SLGHT CHC IN THE AM
HOURS AS ALL CONVECTION ALLOWING MODELS AND OTHER HI RES MODELS
SHOW LITTLE PRECIP AT ALL UNTIL CD FRNT APPROACHES IN THE
AFTERNOON. SO WILL BEGIN THE DAY WITH JUST ISLD-SCT SHRA AT BEST...AND
RAMP UP POPS TO CAT IN THE AFTERNOON.
7 PM UPDATE...ISSUED A SPECIAL WEATHER STATEMENT FOR THE WESTERN
CATSKILLS AND NORTHERN ONEIDA COUNTY FOR A BRIEF PERIOD OF
FREEZING RAIN. RAIN WILL OVERSPREAD THE REGION QUICKLY BY 3-4Z AS
A STRONG SHOT OF LOW-LEVEL MOISTURE ADVECTION AND ISENTROPIC
LIFT/WAA RAPIDLY LEADS TO WIDESPREAD LIGHT RAINS OVER THE AREA. A
FEW HIGHER TERRAIN SPOTS IN THE CATSKILLS AND FAR NORTHEAST ONEIDA
COUNTY COULD BEGIN AS A PERIOD OF FREEZING RAIN AS TEMPERATURES
LIKELY ARE CLOSE TO FREEZING IN THESE AREAS. IT WILL BE VERY
SPOTTY SO NO FZRA ADVY. DUE TO THE STRONG ISENTROPIC LIFT/WARM AIR
ADVECTION...TEMPERATURES SOAR TO 3-7C AT 850 MB BY 6Z AS PER
GFS...WITH SIMILAR TEMPERATURES ON THE NAM...CMC...RAP...AND LOCAL
WRF. THIS WARMING SHUD ALLOW TEMPERATURES TO CLIMB TO THE MID TO
UPPER 30S OR EVEN LOW 40S OVERNIGHT AS THE RAIN FALLS.
FIRST SHOT OF RAIN LIKELY WILL MOVE QUICKLY THRU C NY AND NE PA BY
6-7Z WITH THE NEXT SHOT RAPIDLY APPROACHING ARND 9Z-10Z OR SO AS
ANOTHER LOW-LEVEL JET AND ASSOCIATED MOISTURE ADVECTION AND
ENHANCED ISENTROPIC LIFT APPROACHES. THE WATER VAPOR SATELLITE
IMAGERY SHOWS THESE TWO LOWER-LEVEL WAVES WELL IN THE UPPER LEVEL
MOIST PLUMES...ONE NORTH OF NY AND THE OTHER ACRS THE OH VLLY TO
MID ATLANTIC. THE MODELS HAVE TWO DISTINCT LOW-LEVEL JETS AT 850
MB WHICH ARE TIED TO EACH OF THESE SHORT WAVES. HENCE PRECIP
INCREASES AGAIN LATE TONIGHT WITH NEXT WAVE. .
THEN FOR MONDAY MORNING AFTER THE SECOND WAVE...I SEE A BREAK IN
THE PRECIPITATION BEFORE THE RAIN SHOWERS MOVE THRU THE REGION
ALONG A COLD FRONT WHICH SWINGS THRU IN THE AFTERNOON. THE HIGH
RES WRF ARW AND WRF NMM...LOCAL WRF...RAP AND NAM 4KM ALL SHOW
LITTLE PRECIP MONDAY AM WITH PRECIP INCREASING AGAIN IN THE PM. FOR
NOW DO NOT HAVE THUNDER IN GRIDS FOR MONDAY AFTERNOON...BUT NAM
AND RAP SHOWALTERS ARE SLIGHT NEGATIVE...LOCAL WRF AND GFS ARE
SLIGHTLY POSITIVE. THE HI RES CONVECTION ALLOWING MODELS ALL SHOW
SOME SORT OF LINE OF HEAVIER SHRA ALONG THE COLD FRONT MON PM. SO
I TRENDED POPS DOWNWARD MONDAY AM...THEN INCREASED THEM IN THE
AFTERNOON TO ACCOUNT FOR CD FRONTL SHRA ACVTY. WILL PASS ON IDEA
OF POSSIBLE THUNDER TO MID SHIFT WHICH WILL HAVE THE NEW 00Z
GUIDC TO LOOK AT.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
COLD FRONT APPROACHES THE AREA ON MONDAY. WITH SURFACE LOW
PRESSURE TRACKING UP THE ST LAWRENCE VALLEY OUR AREA WILL BE IN
THE WARM SECTOR MONDAY WITH STEADIER RAIN PULLING OFF TO THE NORTH
AND EAST FOR AWHILE MONDAY MORNING INTO THE AFTERNOON. BASED ON
THIS EXPECT RAIN TO TAPER TO SHOWERS ESPECIALLY OVER NORTHEAST PA.
TEMPERATURES WILL CLIMB WELL INTO THE 50S.
COLD FRONT CROSS THE AREA STARTING AROUND 18Z OVER STEUBEN
COUNTY... AND AROUND 00Z OVER NORTHEAST PA. THIS WILL BE
ACCOMPANIED BY AND FOLLOWED BY A PERIOD OF HEAVIER RAIN. THE RAIN
MAY CHANGE TO A PERIOD OF LIGHT SNOW OVER CENTRAL NY AFTER OOZ AS
WEAK WAVES OF LOW PRESSURE MOVING NORTHEAST ALONG THE FRONT MAY
KEEP THE PRECIPITATION GOING FOR AWHILE MONDAY EVENING IN THE COLD
AIR. TEMPERATURES BRIEFLY COOL TO AROUND -10 AT 850 MB WHICH WILL
BE ENOUGH FOR A BRIEF LAKE RESPONSE LATER MONDAY NIGHT NW FLOW AND
SOME SNOW SHOWERS SOUTHEAST OF LAKE ONTARIO. OVERALL
ACCUMULATIONS OF SNOW MONDAY NIGHT SHOULD BE LESS THAN 2 INCHES.
HIGH PRESSURE MOVES ACROSS THE AREA ON TUESDAY WITH DRY WEATHER
AND SEASONABLY COLD TEMPERATURES. WARMING TREND BEGINS ON
WEDNESDAY AS THE HIGH MOVES OFF TO THE EAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT THROUGH THE EXTENDED
INDICATING SURFACE HIGH PRESSURE WILL PROVIDE DRY AND MILD
CONDITIONS THROUGH FRIDAY. LATE IN THE PERIOD LOW PRES IS FORECAST
TO TRACK FROM THE MID WEST NORTHEAST INTO THE UPPER GREAT LAKES
THEN ACROSS EASTERN CANADA. THE ECMWF IS SLOWER AND FARTHER WEST
WITH THIS SYSTEM THAN THE GFS. WILL CONTINUE WITH CHC POPS
SATURDAY THROUGH SUNDAY WITH PRECIP TYPE A RAIN/SNOW MIX CHANGING
TO ALL RAIN BY SUNDAY AS TEMPS WARM INTO THE LOWER/MIDDLE 40S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL TRACK ACROSS THE LOWER GREAT LAKES TONIGHT...AND
UP THE ST. LAWRENCE RIVER VALLEY ON MONDAY. A WARM FRONT WILL MOVE
ACROSS CENTRAL NY AND NORTHEAST PA TONIGHT. AREAS OF RAIN WILL
SLIDE THROUGH THE REGION DURING THE NEXT 12-24 HOURS WITH IFR AND
OTHER FUEL ALTERNATE MINIMUM RESTRICTIONS TO CEILINGS. VISIBILITIES
SHOULD BE SLIGHTLY BETTER IN CATEGORY WITH FLUCTUATIONS BETWEEN
VFR-MVFR.
WINDS WILL BE PREDOMINANTLY E-SE 5-10 KTS OVERNIGHT BUT A STABLE
BOUNDARY LAYER WILL KEEP DEEP VALLEY FLOWS AT KAVP-KELM LIGHT
AND VARIABLE. A STRONG CORRIDOR OF S-SW FLOW IS EXPECTED TO
DEVELOP ALOFT THIS EVENING WHICH COULD POSE A LLWS PROBLEM
FOR THE LIGHTER SFC WIND STATIONS WITH TOP OF INVERSION WINDS
AROUND 40-45 KTS. ON MONDAY...SW WINDS DEVELOP WITH BETTER MIXING
AT 10-15 KTS WITH A LATE PERIOD WIND SHIFT TO THE WEST-NW
ASSOCIATED WITH COLD FRONTAL PASSAGE.
OUTLOOK...
MON EVNG...IFR/MVFR WITH PERIODS OF RAIN ENDING.
LATE MON NGT/TUE...PATCHY MVFR...MAINLY ACRS CNTRL NY.
TUE NGT-FRI...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...DJN/PVN
SHORT TERM...MSE
LONG TERM...RRM
AVIATION...JAB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
318 AM EST MON DEC 10 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST TODAY...CROSS THE MIDDLE
ATLANTIC REGION TONIGHT...AND STALL OFFSHORE THE SOUTHEAST COAST ON
TUESDAY. COASTAL LOW PRESSURE WILL THEN DEVELOP AND TRACK ALONG THE
OFFSHORE FRONT THROUGH MID WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 930 PM SUNDAY...
WHILE THE FRONTAL ZONE WEST OF THE MOUNTAINS HAS TEMPORARILY LIFTED
NORTH INTO THE OH VALLEY AS A WARM FRONT THIS EVENING...A WEDGE-LIKE
AIRMASS IS LINGERING OVER VA...WITH THE SURFACE FRONT NEAR THE NC/VA
BORDER. NORTH OF THE FRONT...DENSE FOG HAS ALREADY SET IN. WARM
ADVECTION ATOP THE NOCTURNAL STABLE LAYER SHOULD STRENGTHEN THE
INVERSION...BUT THERE IS VERY LITTLE PRECIP HELPING TO FURTHER LOCK
IN THE AIRMASS. THE RAP SHOWS A SOUTHERN WIND PUSHING INTO VA
OVERNIGHT...BUT THIS MAY BE A LITTLE AGGRESSIVE. THUS..WITH THE
BOUNDARY SO CLOSE TOP THE CWA...HAVE ADDED PATCHY FOG OVERNIGHT FOR
THE FAR NORTHERN AREAS OF FORSYTH...GUILFORD AND PERSON COUNTIES.
SOUTH OF THE BOUNDARY...FAIRLY UNIFORM SOUTH-SOUTHWESTERLY LOW LEVEL
FLOW CONTINUES IN THE WARM SECTOR. THE 00Z KGSO AND KMHX RAOBS SHOW
ALL OF THE MOISTURE CONFINED BELOW 750MB WITH A WEAK CAP JUST
ABOVE. THE FEW SHOWERS THAT HAVE DEVELOPED THIS EVENING HAVE
STRUGGLED TO EXTEND ABOVE 11K FT AND HAVE NOT PRODUCED ANY LIGHTNING
DESPITE SOME WEAK CAPE JUST ABOVE THE CAP. FORCING ALOFT IS
DIFFICULT TO LOCATE IN THE MOIST SOUTHWESTERLY FLOW AHEAD OF THE
MAIN UPPER TROUGH...BUT REGIONAL SURFACE AND 850MB OBS SHOW A WEAK
WAVE NEAR SC/GA COASTAL AREAS. WHILE THIS WAVE IS FORECAST TO
WEAKEN FURTHER AS IT MOVES ALONG THE COAST...MOST OF THE FORECAST
MODELS SHOW A SLUG OF ISENTROPIC LIFT IN THE 295-305K LAYER MOVING
NORTH THROUGH THE COASTAL PLAIN AROUND 09Z. THE AVAILABLE CAMS SHOW
WHAT SHOULD BE SOME LOW TOPPED SHOWERS BRUSHING THE I-95
CORRIDOR...ESPECIALLY OVER THE NORTHERN COASTAL PLAIN. WILL HAVE A
30 POP IN THIS AREA AFTER 09Z...AND KEEP THE MENTION OF ISOLATED
SHOWERS ELSEWHERE.
TEMPS CURRENTLY IN THE UPPER 50S AND LOWER 60S WILL SHOULDN FALL
TOO MUCH MORE UNDER MOSTLY OVERCAST SKIES...SO WILL ONLY ADJUST LOWS
TO MATCH THE CURRENT TRENDS. LOWS 55-61. -BLS
MONDAY:
THERE IS GOOD AGREEMENT WITH THE TIMING OF THE COLD FRONT INTO
WESTERN NC LATE MONDAY AFTERNOON. THE LATE ARRIVAL OF THE SFC COLD
FRONT WILL KEEP THE ASSOCIATED MAIN BAND OF CONVECTION WEST OF THE
AREA UNTIL 21 TO 00Z. PRIOR TO THE ARRIVAL OF THIS BAND...ISOLATED
TO SCATTERED SHOWERS WILL BE POSSIBLE ACROSS CENTRAL NC WITHIN THE
40-50KT H8 LOW-LEVEL JET AND INCREASING RIGHT-ENTRANCE REGION
DYNAMICS. MODELS INDICATE ONLY MARGINAL INSTABILITY(200 TO 500
J/KG)...A LIKELY PRODUCT OF WIDESPREAD CLOUD COVER. GIVEN THE LACK
OF INSTABILITY AND THE SHORTWAVE DYNAMICS RACING OFF TO THE
NORTHEAST(GREAT LAKES)...EXPECT THUNDER TO BE AN EXCEPTION NOT THE
RULE. WILL PUT IN ISOLATED THUNDER IN THE FAR WESTERN ZONES ONLY.
TEMPERATURES WILL BE DEPENDENT ON CLOUD COVER AND PRECIP
COVERAGE...WITH HIGHS A TOUCH COOLER THAN PREVIOUSLY THOUGHT.
HIGHS IN THE UPPER 60S NW TO MID 70S SOUTHEAST WITH BREEZY SWLY
WINDS OF 15 T0 25 MPH.
A COLD FRONT WILL APPROACH AND CROSS THE REGION OVERNIGHT MONDAY
INTO TUESDAY. PRECIP CHANCES WILL RAMP UP NEAR SUNSET ON MONDAY
ACROSS THE WEST AND THEN MOVE EASTWARD THROUGH THE OVERNIGHT HOURS
AND INTO EARLY TUESDAY. IT SHOULD BE NOTED THAT MODELS CONTINUE TO
TREND DRIER FOR CENTRAL NC WITH THE PASSAGE OF THIS COLD FRONT. IN
FACT...MODELS INDICATE A LINE OF SHOWERS ALONG AND AHEAD OF THE
FRONT MOVING INTO THE WESTERN PIEDMONT BY SUNSET...THEN WEAKENING
SIGNIFICANTLY AS IT MOVES EASTWARD INTO THE MORE STABLE AIR OVER THE
PIEDMONT/COASTAL PLAIN. AS A RESULT...WILL MAINTAIN LIKELY POPS FOR
LATE MONDAY/MONDAY EVENING IN THE WEST...WITH ONLY CHANCE POPS
FURTHER EAST TROUGH EARLY TUESDAY. PRECIP SHOULD COME TO AN END
TUESDAY AFTERNOON AS THE FRONT MOVES EAST OF THE AREA. INSTABILITY
APPEARS TO BE MARGINAL (AT BEST) AS THE FRONT CROSSES THE AREA
MONDAY NIGHT...BUT CANNOT COMPLETELY RULE OUT AN ISOLATED
THUNDERSTORM OR TWO.
TEMPS MONDAY NIGHT AND TUESDAY WILL ULTIMATELY BE DETERMINED BY THE
TIMING OF THE FRONT AND ASSOCIATED PRECIP AND EVENTUAL CAA. WITH THE
CURRENT TIMING OF THE FRONT IN MIND...WILL SHOW MILD TEMPS MONDAY
NIGHT...GENERALLY IN THE 50S. HIGHS ON TUESDAY ARE EXPECTED TO BE IN
THE MID/UPPER 50S ACROSS THE NORTHWEST (DUE TO THE EARLIER FRONTAL
PASSAGE) TO THE LOW/MID 60S FURTHER SOUTH AND EAST. THESE HIGHS MAY
VERY WELL OCCUR IN THE MORNING AND THEN FALL THROUGHOUT THE DAY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 305 AM MONDAY...
IN RESPONSE TO THE APPROACH AND AMPLIFICATION OF A POSITIVELY-TILTED
TROUGH ALOFT - ONE COMPRISED BY PHASED NORTHERN AND SOUTHERN STREAMS
DOWNSTREAM OF A RETROGRESSIVE AND FLOW-SPLITTING RIDGE OVER THE
EAST PACIFIC - THE LOW LEVEL FRONTAL FROM THE NEAR TERM WILL STALL
OFFSHORE THE SOUTHEAST COAST. A SERIES OF FRONTAL WAVES WILL
SUBSEQUENTLY DEVELOP AND MIGRATE NORTHEASTWARD ALONG THE FRONTAL
ZONE.
WHILE THE STRONGEST DEEP LAYER LIFT AND MOISTENING IS CONSEQUENTLY
FORECAST TO HOLD ALONG THE SURFACE FRONT OFFSHORE...SLOPED ASCENT
ACROSS THE FRONTAL ZONE AND ASSOCIATED ANAFRONTAL RAIN WILL OCCUR
WESTWARD ACROSS PORTIONS OF CENTRAL...AND EASTERN NC LATE TUE
NIGHT-WED. HAVE ACCORDINGLY RAISED POP TO LIKELY WITH A QUARTER TO
HALF IN OF RAIN ACROSS THE SOUTHERN AND CENTRAL COASTAL
PLAIN...TAPERING TO CHANCE OVER CENTRAL ZONES...AND AOB SLIGHT
CHANCE OVER THE FAR WESTERN PIEDMONT (INCLUDING THE TRIAD). THICKER
AND LOWER OVERCAST...AND RAIN...EAST VS. WEST SHOULD YIELD
RELATIVELY UNIFORM TEMPERATURES IN THE UPPER 40S TO AROUND 50
DEGREES WEDNESDAY...AFTER CAA-DRIVEN BUT CLOUD-TEMPERED LOWS IN THE
UPPER 30S TO LOWER-MIDDLE 40S. WEST TO EAST CLEARING IN STRONG
SUBSIDENCE BEHIND THE TROUGH ALOFT...AND THE ASSOCIATED EASTWARD
MIGRATION OF MODIFIED ARCTIC HIGH PRESSURE THAT CONSISTS OF SUB-ZERO
TEMPERATURES OVER THE NORTHERN PLAINS THIS MORNING...SHOULD PROMOTE
EXCELLENT RADIATIONAL COOLING CONDITIONS...PARTICULARLY AWAY FROM A
LINGERING MSLP GRADIENT OVER THE COASTAL PLAIN. A TWO CATEGORY
REDUCTION TO WED NIGHT LOWS WERE WARRANTED...GIVEN 12Z PROJECTED
LOW LEVEL THICKNESS VALUES IN THE 1305 METER RANGE AND THE
AFOREMENTIONED EXCELLENT RADIATIONAL COOLING - LOWER-MIDDLE 20S WEST
TO AROUND FREEZING SOUTHEAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...
THE MODIFIED ARCTIC HIGH WILL UNDERGO FURTHER MODIFICATION AS IT
REMAINS OVERHEAD THROUGH THE END OF THE WORK WEEK...BEFORE SHIFTING
OFFSHORE AND YIELDING A MORE RAPIDLY MODERATING SOUTHERLY RETURN
FLOW FOR THE START OF THE WEEKEND. MEDIUM RANGE GUIDANCE IS THEN IN
GENERAL AGREEMENT...THE FASTER 00Z/10TH GFS NOTWITHSTANDING...THAT
THE NEXT FRONTAL SYSTEM WILL AFFECT OUR REGION WITH A CHANCE OF
SHOWERS SUNDAY INTO SUNDAY NIGHT. THE TREND TOWARD COOLER LOWS FROM
THE SHORT TERM WILL CONTINUE WITH EXCELLENT RADIATIONAL COOLING
WITHIN THE SURFACE RIDGE AXIS THU NIGHT (MIDDLE-UPPER 20S)...
CONTRASTED BY MODERATING TEMPS INTO THE UPPER 50S TO LOWER-MIDDLE
60S FOR HIGHS BY THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 145 AM MONDAY...
24-HR TAF PERIOD:
CONFIDENCE IS HIGHER THAN PREVIOUS NIGHTS THAT IFR/LIFR CEILINGS
WILL DEVELOP BETWEEN 06-12Z IN ASSOCIATION WITH AN INCREASINGLY
MOIST LOW-LEVEL SOUTHERLY FLOW...THOUGH SOME UNCERTAINTY PERSISTS...
MORE-SO AT THE EASTERN TERMINALS WHERE IT IS POSSIBLE THAT CEILINGS
AND VISBYS BOUNCE AROUND MORE...OR DO NOT FALL BELOW THE MVFR
CATEGORY. REGARDLESS...EXPECT CEILINGS AND VISBYS TO IMPROVE TO MVFR
BETWEEN 12-15Z AS SOUTHERLY FLOW/MIXING STRENGTHEN IN ADVANCE OF A
COLD FRONT APPROACHING THE MOUNTAINS FROM THE WEST...WITH MVFR OR
VFR CEILINGS DURING THE AFTERNOON. EXPECT SOUTHWESTERLY WINDS TO
BECOME SUSTAINED AT 10-15 KT WITH GUSTS TO 20 KT BY 15Z... FURTHER
INCREASING TO 15-20 KT WITH GUSTS UP TO 30 KT POSSIBLE DURING THE
AFTERNOON. SOUTHWESTERLY WINDS WILL WEAKEN AFTER SUNSET AS THE FRONT
PUSHES INTO THE FOOTHILLS...VEERING TO THE NW/NNW AT 10-15 KT AT
FROPA...WHICH IS ANTICIPATED ~06Z TUE AT INT/GSO...~09Z AT RDU...AND
09-12Z AT FAY/RWI. AT THIS TIME...DO NOT EXPECT MUCH IN THE WAY OF
PRECIPITATION WITH THE FRONT...THOUGH SHOWER ACTIVITY AND LOCALLY
REDUCED CEILINGS WILL BE POSSIBLE BETWEEN 00-12Z TUE AT ALL TAF
SITES.
LOOKING AHEAD:
A PERIOD OF VFR CONDITIONS IS EXPECTED IN THE WAKE OF THE FRONTAL
PASSAGE DURING THE DAY TUE...THOUGH MVFR CEILINGS MAY PERSIST AT THE
FAY/RWI TERMINALS. THE FRONT WILL STALL JUST OFFSHORE THE CAROLINA
COAST TUE NIGHT. EXPECT INCREASING CHANCES FOR RAIN AND CEILINGS
DETERIORATING TO IFR/LIFR AT THE RDU/FAY/RWI TERMINALS AND AT LEAST
MVFR/IFR AT THE INT/GSO TERMINALS BETWEEN 00-12Z WED AS A WAVE OF
LOW PRESSURE DEVELOPS ALONG THE STALLED FRONT. SUB-VFR CEILINGS ARE
EXPECTED TO PERSIST THROUGH THE DAY WED...WITH A RETURN TO DRY/VFR
CONDITIONS WED NIGHT THROUGH THE REMAINDER OF THE WEEK. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...CBL/BLS
SHORT TERM...MWS
LONG TERM....MWS
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
150 AM EST MON DEC 10 2012
.SYNOPSIS...
A WARM SOUTHERLY FLOW WILL PREVAIL OVER THE CAROLINAS TODAY...IN
ADVANCE OF A COLD FRONT APPROACHING THE MOUNTAINS FROM THE WEST. THE
COLD FRONT WILL CROSS CENTRAL NORTH CAROLINA EARLY TUESDAY
MORNING...THEN SLOW DOWN AND STALL JUST OFFSHORE THE CAROLINA COAST.
A WAVE OF LOW PRESSURE IS EXPECTED TO DEVELOP ALONG THE STALLED
FRONT TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 930 PM SUNDAY...
WHILE THE FRONTAL ZONE WEST OF THE MOUNTAINS HAS TEMPORARILY LIFTED
NORTH INTO THE OH VALLEY AS A WARM FRONT THIS EVENING...A WEDGE-LIKE
AIRMASS IS LINGERING OVER VA...WITH THE SURFACE FRONT NEAR THE NC/VA
BORDER. NORTH OF THE FRONT...DENSE FOG HAS ALREADY SET IN. WARM
ADVECTION ATOP THE NOCTURNAL STABLE LAYER SHOULD STRENGTHEN THE
INVERSION...BUT THERE IS VERY LITTLE PRECIP HELPING TO FURTHER LOCK
IN THE AIRMASS. THE RAP SHOWS A SOUTHERN WIND PUSHING INTO VA
OVERNIGHT...BUT THIS MAY BE A LITTLE AGGRESSIVE. THUS..WITH THE
BOUNDARY SO CLOSE TOP THE CWA...HAVE ADDED PATCHY FOG OVERNIGHT FOR
THE FAR NORTHERN AREAS OF FORSYTH...GUILFORD AND PERSON COUNTIES.
SOUTH OF THE BOUNDARY...FAIRLY UNIFORM SOUTH-SOUTHWESTERLY LOW LEVEL
FLOW CONTINUES IN THE WARM SECTOR. THE 00Z KGSO AND KMHX RAOBS SHOW
ALL OF THE MOISTURE CONFINED BELOW 750MB WITH A WEAK CAP JUST
ABOVE. THE FEW SHOWERS THAT HAVE DEVELOPED THIS EVENING HAVE
STRUGGLED TO EXTEND ABOVE 11K FT AND HAVE NOT PRODUCED ANY LIGHTNING
DESPITE SOME WEAK CAPE JUST ABOVE THE CAP. FORCING ALOFT IS
DIFFICULT TO LOCATE IN THE MOIST SOUTHWESTERLY FLOW AHEAD OF THE
MAIN UPPER TROUGH...BUT REGIONAL SURFACE AND 850MB OBS SHOW A WEAK
WAVE NEAR SC/GA COASTAL AREAS. WHILE THIS WAVE IS FORECAST TO
WEAKEN FURTHER AS IT MOVES ALONG THE COAST...MOST OF THE FORECAST
MODELS SHOW A SLUG OF ISENTROPIC LIFT IN THE 295-305K LAYER MOVING
NORTH THROUGH THE COASTAL PLAIN AROUND 09Z. THE AVAILABLE CAMS SHOW
WHAT SHOULD BE SOME LOW TOPPED SHOWERS BRUSHING THE I-95
CORRIDOR...ESPECIALLY OVER THE NORTHERN COASTAL PLAIN. WILL HAVE A
30 POP IN THIS AREA AFTER 09Z...AND KEEP THE MENTION OF ISOLATED
SHOWERS ELSEWHERE.
TEMPS CURRENTLY IN THE UPPER 50S AND LOWER 60S WILL SHOULDN FALL
TOO MUCH MORE UNDER MOSTLY OVERCAST SKIES...SO WILL ONLY ADJUST LOWS
TO MATCH THE CURRENT TRENDS. LOWS 55-61. -BLS
MONDAY:
THERE IS GOOD AGREEMENT WITH THE TIMING OF THE COLD FRONT INTO
WESTERN NC LATE MONDAY AFTERNOON. THE LATE ARRIVAL OF THE SFC COLD
FRONT WILL KEEP THE ASSOCIATED MAIN BAND OF CONVECTION WEST OF THE
AREA UNTIL 21 TO 00Z. PRIOR TO THE ARRIVAL OF THIS BAND...ISOLATED
TO SCATTERED SHOWERS WILL BE POSSIBLE ACROSS CENTRAL NC WITHIN THE
40-50KT H8 LOW-LEVEL JET AND INCREASING RIGHT-ENTRANCE REGION
DYNAMICS. MODELS INDICATE ONLY MARGINAL INSTABILITY(200 TO 500
J/KG)...A LIKELY PRODUCT OF WIDESPREAD CLOUD COVER. GIVEN THE LACK
OF INSTABILITY AND THE SHORTWAVE DYNAMICS RACING OFF TO THE
NORTHEAST(GREAT LAKES)...EXPECT THUNDER TO BE AN EXCEPTION NOT THE
RULE. WILL PUT IN ISOLATED THUNDER IN THE FAR WESTERN ZONES ONLY.
TEMPERATURES WILL BE DEPENDENT ON CLOUD COVER AND PRECIP
COVERAGE...WITH HIGHS A TOUCH COOLER THAN PREVIOUSLY THOUGHT.
HIGHS IN THE UPPER 60S NW TO MID 70S SOUTHEAST WITH BREEZY SWLY
WINDS OF 15 T0 25 MPH.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
AS OF 300 PM SUNDAY...
A COLD FRONT WILL APPROACH AND CROSS THE REGION OVERNIGHT MONDAY
INTO TUESDAY. PRECIP CHANCES WILL RAMP UP NEAR SUNSET ON MONDAY
ACROSS THE WEST AND THEN MOVE EASTWARD THROUGH THE OVERNIGHT HOURS
AND INTO EARLY TUESDAY. IT SHOULD BE NOTED THAT MODELS CONTINUE TO
TREND DRIER FOR CENTRAL NC WITH THE PASSAGE OF THIS COLD FRONT. IN
FACT...MODELS INDICATE A LINE OF SHOWERS ALONG AND AHEAD OF THE
FRONT MOVING INTO THE WESTERN PIEDMONT BY SUNSET...THEN WEAKENING
SIGNIFICANTLY AS IT MOVES EASTWARD INTO THE MORE STABLE AIR OVER THE
PIEDMONT/COASTAL PLAIN. AS A RESULT...WILL MAINTAIN LIKELY POPS FOR
LATE MONDAY/MONDAY EVENING IN THE WEST...WITH ONLY CHANCE POPS
FURTHER EAST TROUGH EARLY TUESDAY. PRECIP SHOULD COME TO AN END
TUESDAY AFTERNOON AS THE FRONT MOVES EAST OF THE AREA. INSTABILITY
APPEARS TO BE MARGINAL (AT BEST) AS THE FRONT CROSSES THE AREA
MONDAY NIGHT...BUT CANNOT COMPLETELY RULE OUT AN ISOLATED
THUNDERSTORM OR TWO.
TEMPS MONDAY NIGHT AND TUESDAY WILL ULTIMATELY BE DETERMINED BY THE
TIMING OF THE FRONT AND ASSOCIATED PRECIP AND EVENTUAL CAA. WITH THE
CURRENT TIMING OF THE FRONT IN MIND...WILL SHOW MILD TEMPS MONDAY
NIGHT...GENERALLY IN THE 50S. HIGHS ON TUESDAY ARE EXPECTED TO BE IN
THE MID/UPPER 50S ACROSS THE NORTHWEST (DUE TO THE EARLIER FRONTAL
PASSAGE) TO THE LOW/MID 60S FURTHER SOUTH AND EAST. THESE HIGHS MAY
VERY WELL OCCUR IN THE MORNING AND THEN FALL THROUGHOUT THE DAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...
TUESDAY NIGHT THROUGH WEDNESDAY...THERE STILL IS QUITE A BIT OF
UNCERTAINTY WITH RESPECT TO THE WEATHER FOR THIS TIME FRAME. ALL THE
MODELS SHOW THE FRONT HANGING NEAR THE COAST WITH MULTIPLE LOW
PRESSURE WAVES TRACKING ALONG IT AND SPREADING PRECIP INTO EASTERN
NC...ALTHOUGH HOW FAR EAST IS IN QUESTION. ALL MODELS ALSO SHOW A
MID LEVEL WAVE TRACKING EASTWARD ACROSS THE AREA DURING THIS TIME
FRAME...ALTHOUGH TIMING/STRENGTH IS NOT WELL AGREED UPON. NOW THE
GFS IS STRONGER AND SLOWER (OPPOSITE OF 24 HOURS AGO) AND ACTUALLY
SPREADS PRECIP ACROSS THE ENTIRE FORECAST AREA LATE TUESDAY NIGHT
INTO WEDNESDAY. THE NAM SUPPORTS THIS SOLUTION SOMEWHAT...BUT THE
ECMWF AND CANADIAN KEEP MOST OF THE PRECIP ACROSS THE EASTERN
PORTIONS OF THE FORECAST AREA. FOR NOW...WILL MAINTAIN FORECAST
CONTINUITY AND SHOW A CHANCE OF RAIN IN THE EAST LATE TUESDAY NIGHT
AND WEDNESDAY...WITH ONLY A SLIGHT CHANCE FURTHER WEST. TEMPS WILL
LIKELY BE NEAR TO SLIGHTLY ABOVE NORMAL DURING THIS TIME FRAME.
THURSDAY THOUGH SUNDAY...CONDITIONS THEN LOOK TO IMPROVE FOR THE END
OF THE WORK WEEK AS SURFACE HIGH PRESSURE AND MID LEVEL RIDGING
BUILD INTO THE AREA. MODELS THEN SHOW THE NEXT SYSTEM APPROACHING
THE REGION OVER THE WEEKEND...WITH CLOUDS AND PRECIP CHANCES
POSSIBLY BEGINNING TO INCREASE LATE SATURDAY (ALTHOUGH TIMING THIS
FAR OUT IS ALWAYS IN QUESTION). TEMPS WILL SLOWLY MODERATE AT THE
END OF THE WEEK AND ESPECIALLY INTO THE WEEKEND AS THE SURFACE HIGH
MOVES OFFSHORE AND SOUTHERLY FLOW RETURNS TO THE AREA.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 145 AM MONDAY...
24-HR TAF PERIOD:
CONFIDENCE IS HIGHER THAN PREVIOUS NIGHTS THAT IFR/LIFR CEILINGS
WILL DEVELOP BETWEEN 06-12Z IN ASSOCIATION WITH AN INCREASINGLY
MOIST LOW-LEVEL SOUTHERLY FLOW...THOUGH SOME UNCERTAINTY PERSISTS...
MORE-SO AT THE EASTERN TERMINALS WHERE IT IS POSSIBLE THAT CEILINGS
AND VISBYS BOUNCE AROUND MORE...OR DO NOT FALL BELOW THE MVFR
CATEGORY. REGARDLESS...EXPECT CEILINGS AND VISBYS TO IMPROVE TO MVFR
BETWEEN 12-15Z AS SOUTHERLY FLOW/MIXING STRENGTHEN IN ADVANCE OF A
COLD FRONT APPROACHING THE MOUNTAINS FROM THE WEST...WITH MVFR OR
VFR CEILINGS DURING THE AFTERNOON. EXPECT SOUTHWESTERLY WINDS TO
BECOME SUSTAINED AT 10-15 KT WITH GUSTS TO 20 KT BY 15Z... FURTHER
INCREASING TO 15-20 KT WITH GUSTS UP TO 30 KT POSSIBLE DURING THE
AFTERNOON. SOUTHWESTERLY WINDS WILL WEAKEN AFTER SUNSET AS THE FRONT
PUSHES INTO THE FOOTHILLS...VEERING TO THE NW/NNW AT 10-15 KT AT
FROPA...WHICH IS ANTICIPATED ~06Z TUE AT INT/GSO...~09Z AT RDU...AND
09-12Z AT FAY/RWI. AT THIS TIME...DO NOT EXPECT MUCH IN THE WAY OF
PRECIPITATION WITH THE FRONT...THOUGH SHOWER ACTIVITY AND LOCALLY
REDUCED CEILINGS WILL BE POSSIBLE BETWEEN 00-12Z TUE AT ALL TAF
SITES.
LOOKING AHEAD:
A PERIOD OF VFR CONDITIONS IS EXPECTED IN THE WAKE OF THE FRONTAL
PASSAGE DURING THE DAY TUE...THOUGH MVFR CEILINGS MAY PERSIST AT THE
FAY/RWI TERMINALS. THE FRONT WILL STALL JUST OFFSHORE THE CAROLINA
COAST TUE NIGHT. EXPECT INCREASING CHANCES FOR RAIN AND CEILINGS
DETERIORATING TO IFR/LIFR AT THE RDU/FAY/RWI TERMINALS AND AT LEAST
MVFR/IFR AT THE INT/GSO TERMINALS BETWEEN 00-12Z WED AS A WAVE OF
LOW PRESSURE DEVELOPS ALONG THE STALLED FRONT. SUB-VFR CEILINGS ARE
EXPECTED TO PERSIST THROUGH THE DAY WED...WITH A RETURN TO DRY/VFR
CONDITIONS WED NIGHT THROUGH THE REMAINDER OF THE WEEK. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...CBL/BLS
SHORT TERM...KRR
LONG TERM....KRR
AVIATION...VINCENT
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
902 PM CST TUE DEC 11 2012
.DISCUSSION...
FCST BEHAVING PRETTY WELL. HAD A FEW ROGUE PATCHES OF STRATOCU
STILL IN THE VALLEY INTO NW MN....BUT OTHERWISE MANY SITES IN THE
CLEAR AREAS DROPPING TO BELOW ZERO AS EXPECTED EARLY THIS EVENING.
A FEW COLDER SPOTS DOWN TO -10 OR SO FROM HALLOCK TO FOSSTON.
SATELLITE AND OBS AT 02Z SHOWS THE MID CLOUDS ADVANCING EAST INTO
THE RED RIVER VALLEY AND WILL OVERSPREAD THE ENTIRE FCST AREA BY
06Z.
NOW WITH THE SNOWFALL. CANADIAN AND MINOT RADARS HAVE SHOWN AN
EAST-SOUTHEAST MOVEMENT OF THE SNOW UPSTREAM. 18Z GFS MAINTAINED A
HIGHER QPF IN NORTHEAST ND DOWN TO GRAND FORKS THAN THE 18Z OR NEW
00Z NAM AND 01Z RAP MODELS WHICH MAINTAIN MAIN QPF (.10 TO .15)
ALONG NRN TIER OF COUNTIES AS PREV THOUGHT. WILL MAINTAIN THIS
IDEA IN FCST WITH HIGHEST POPS (CATEGORICAL 06Z TO 12Z ALONG NRN
TIER OF COUNTIES WITH TIGHT GRADIENT TO SMALL CHC POPS BTWN GFK-
FAR. MINOT RADAR AND OBS WOULD INDICATE A BRIEF BAND OF -SN PSBL
DOWN TO FARGO LATER TONIGHT BUT MAIN ACTION SHOULD STAY NORTH OF
HIGHWAY TWO AS EXPECTED WITH 2-3 INCHES ALONG THE BORDER. SFC LOW
TRACK CRUCIAL WITH REGARDS TO TEMPS. GFS HAS SFC LOW TRACKING A
BIT SOUTH OF GFK WED AND KEEPING GFK IN A BIT COLDER AIR THAN 00Z
NAM AND RAP WHICH HAS SFC LOW NR A CANDO-GRAFTON-WASKISH LINE.
DOES APPEAR AREAS NORTH OF SFC LOW TO REMAIN IN COLD AIRMASS AND
STRUGGLE TO GET INTO THE TEENS WHILE SOUTH OF LOW MID TO UPR 20S
VERY REASONABLE WITH SOME LOWER 30S IN DOWNSLOPE AREAS OFF THE
SISSETON HILLS IN SARGENT AND RICHLAND COUNTIES IN SE ND.
UPDATED TEMP CURVE A BIT THRU WED FOR A BIT COLDER TEMPS (MAY NOT
BE COLD ENOUGH) OVER THE FAR NORTH. OTHERWISE LITTLE CHANGE.
&&
.PREV DISCUSSION... /ISSUED 256 PM CST TUE DEC 11 2012/
SHORT TERM... /TONIGHT THROUGH FRIDAY/
THE FORECAST CHALLENGE FOR THE SHORT TERM WILL BE OVERNIGHT LOWS
AND SNOWFALL AMOUNTS ACROSS THE FAR NORTHERN ZONES. MODELS ARE IN
GENERAL AGREEMENT TODAY...ALTHOUGH THE RUC HAS A MUCH BETTER
HANDLE ON CLOUDS CURRENTLY ACROSS WESTERN NORTH DAKOTA. THEREFORE
WILL USE A FORECAST BLEND.
MAJORITY OF OUR CWA IS CLEAR OR UNDER THIN STRATUS...WITH SOME
REMNANTS OF TODAYS CLOUD COVER OVER THE CENTRAL VALLEY EXTENDING
EASTWARD INTO SOUTHERN BELTRAMI COUNTY. RADAR ECHOES HAVE BEEN
WEAK TODAY...AND DESPITE SNOW AT SEVERAL METARS IN WEST CENTRAL MN
EARLIER THIS AFTN...CONTINUE TO EXPECT THIS TO BE FLURRY ACTIVITY
WITH NO ACCUMULATION.
TONIGHT...THE LATEST RUC HAS THE BEST HANDLE ON MOISTURE ADVECTION
AND PLACEMENT OF CLOUDS JUST WEST OF THE MISSOURI RIVER IN WRN ND.
WILL CONSIDER THE RUC TIMING OF CLOUDS INTO MY WESTERN ZONES FOR
FCST LOWS...WHICH WILL OCCUR EARLY IN THE EVENING AS CLOUDS
ENCROACH FROM THE WEST. THINK THE NAM IS TOO FAST AND THE GEM HAS
A DECENT HANDLE ON THE COLDEST TEMPS...BUT THE LATTER MAY STILL BE
TOO FAST IN BRINGING CLOUD COVER IN. THUS WILL LEAN TOWARD GEM
SOLUTION BUT CUT TEMPS FURTHER DOWN ALONG WESTERN ZONES AS I
BELIEVE WE WILL HAVE A COUPLE OF HOURS FOR TEMPS TO DROP BEFORE
CLOUDS MOVE IN...GIVEN SNOW ESP IN THE NORTHWEST...AND OVERNIGHT
TEMPS BEGIN TO RISE. COLDEST TEMPS SHOULD BE IN NORTHWEST
MINNESOTA NORTH OF THE PRESENT CLOUDS. COULD SEE TEMPS DOWN INTO
DOUBLE DIGITS...PER GEM GUIDANCE...BUT GENERALLY KEPT TEMPS IN THE
5 TO 10 BELOW RANGE.
LOW PRESSURE WILL THEN MOVE ACROSS THE NORTHERN TIER WITH MODEST
WARM ADVECTION / ISENTROPIC LIFT AFT 03Z. MODELS IN DECENT
AGREEMENT ON PLACEMENT OF SNOWFALL...WITH THE NORTHERN VALLEY
EXPECTED TO RECEIVE THE MOST AS NORTHEASTERN ND EXPECTED TO HAVE
THE STRONGEST ISENTROPIC LIFT. GENERALLY 1 TO 3 INCHES ACROSS THE
NORTH AS THIS SYSTEM MOVES BY. CLOUD ADVECTION WILL CAUSE MOST
SITES TO SEE OVERNIGHT TEMPS BEGIN TO RISE BY 06Z TO 09Z (EARLIER
IN THE WEST). BEST ISENTROPIC LIFT / LOWEST CONDENSATION PRESSURE
DEFICITS GENERALLY NORTH OF THE HWY 2 CORRIDOR SO EXPECT A SHARP
CUTOFF ACROSS SOUTHERN ZONES...BUT SOME FLURRIES ARE POSSIBLE.
WEDNESDAY AND WED NIGHT...MODELS GENERALLY PULL PRECIP OUT OF REGION BY
EARLY AFTERNOON TUESDAY. THUS HAVE REDUCED POPS FOR AFTN HOURS.
NORTHERLY FLOW THEN USHERS IN A COLD CANADIAN AIR MASS. MODELS
ARE PRODUCING PRECIP WEDNESDAY NIGHT AS A JET MAX MOVES ACROSS
SOUTH DAKOTA. WHILE ISENTROPIC SURFACES DO BRING A SWATH OF LOWER
CONDENSATION PRESSURE DEFICITS ACROSS THE AREA...ISENTROPIC LIFT
IS WEAK. HOWEVER DO SEE POTENTIAL FOR MORE STRATUS AND FLURRIES AS
MODELS INDICATE LOW LEVEL MOISTURE MOVING IN AFT 06Z. WILL
CONTINUE FLURRIES FOR WED NIGHT.
THURSDAY... RETURN FLOW WILL SLOWLY BEGIN OVER DEVILS LAKE REGION
ON THU. GFS SHOWS MODEST ISENTROPIC LIFT OVER WESTERN
ZONES...WITH MODERATELY LOW CONDENSATION PRESSURE DEFICITS WHILE
THE NAM IS DRY. WILL CONTINUE SLIGHT CHANCE POPS IN THE
WEST...HOWEVER CONFIDENCE FOR MEASURABLE PRECIP WITH THIS WAVE IS
LOW GIVEN MODEL DIFFERENCES.
FRIDAY...SOUTHEASTERLY FLOW AND INCREASED SOLAR SHOULD ALLOW TEMPS
TO RISE INTO THE UPPER TEENS IN THE NORTH AND LOWER 20S ACROSS THE
SOUTH...WITH FRIDAY BEING THE WARMEST DAY OF THE SHORT TERM.
LONG TERM... /FRIDAY NIGHT THROUGH TUESDAY/
PSEUDO SPLIT FLOW THROUGH THE PERIOD WITH THE MAIN STORM TRACK SOUTH
OF FA THIS WEEKEND. FARTHER NORTH SOLUTIONS OF GEM/ECMWF HAVE FAR
SE/E FA ON NORTHERN FRINGE OF SNOW SHIELD SO WILL MAINTAIN LOW POPS
THIS AREA. TEMPERATURES LOOK SEASONAL WITH NO REAL COLD AIR
INTRUSION THROUGH THE PERIOD.
AVIATION...
CLEARING CONTINUES TO SPREAD FROM NW-SE WITH MOST OF FA VFR BY LATE
AFTERNOON. VFR CIGS WILL SPREAD IN LATER TONIGHT WITH -SN DEVELOPING
ACROSS FAR NORTH LATE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
RIDDLE/SPEICHER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
310 PM EST MON DEC 10 2012
.SYNOPSIS...
A STRONG COLD FRONT DEPARTS TO THE EAST THROUGH THE NIGHT. HIGH
PRESSURE BUILDS MID WEEK AND LINGERS INTO FRIDAY. NEXT
PRECIPITATION MAKER LONG ABOUT SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TUESDAY/...
SURFACE COLD FRONT IS CURRENTLY CROSSING OHIO RIVER...PER OBS AND
RADAR. THE ENHANCED PRECIP BEHIND THE FRONT APPEARS TIED TO THE 925
MB FRONT. BECAUSE OF THIS ENHANCEMENT BEHIND THE SURFACE FRONT DID
DRAW HIGHER POPS A LITTLE FARTHER WEST THAN PREVIOUS FORECAST.
PRECIP OUT AHEAD OF THE FRONT HAS BEEN FAIRLY LIGHT...WITH LIGHT
RAIN OR EVEN JUST SOME MIST/SPRINKLES BEING REPORTED BY ASOS/S
ACROSS THE FORECAST AREA. HAVE SEEN SOME LIGHTNING JUST WEST AND
NORTH OF OUR CWA...AGAIN IT SEEMS TIED MOST CLOSELY TO THE 925 FRONT
AND UPPER LEVEL ENHANCEMENT PROVIDED BY A VORT MAX RIDING UP THE
FRONT. THAT VORT MAX HAS MOVED OFF THE NORTHEAST AND HAVE NOT SEEN
ANY LIGHTNING FOR ABOUT AN HOUR...HOWEVER RAP SHOWING ANOTHER VORT
MAX SHOULD RIDE NE ALONG THE FRONT THIS AFTERNOON...SO TRIED TO TIE
SOME SLIGHT CHANCE THUNDER TO THE 925 FRONT AND 500MB VORT MAX
COMBINATION. REALLY SHOULD NOT BE MORE THAN SOME RANDOM STRIKES
THROUGH THE AFTERNOON. MOST LOCATIONS ACROSS WV AT OR NEAR THEIR
HIGH FOR THE DAY...WITH FALLING TEMPERATURES ALREADY SHOWING UP
BEHIND THE FRONT IN SE OHIO. EXPECT A QUICK 5-10 DEGREE DROP IN THE
HOUR TO TWO AFTER THE FRONT PASSES...WITH A SLOWER COOLING TREND
AFTER THAT INTO TONIGHT. LAV GUIDANCE SEEMED FAIRLY CLOSE TO CURRENT
TRENDS...SO USED THAT AS A STARTING POINT FOR TODAYS NON-DIURNAL
CURVE.
PRECIPITATION WILL SLOWLY COME TO AN END OVERNIGHT FROM WEST TO EAST
AS THE SYSTEM MOVES EAST AND HIGH PRESSURE BEGINS TO BUILD TO THE
WEST. AS COOLER TEMPERATURES ALOFT MOVE IN...WILL SEE A TRANSITION
FROM RAIN TO SNOW JUST AS THE PRECIP IS MOVING OUT. SHOULD NOT SEE
ANY ACCUMULATIONS IN THE LOWLANDS...WITH GENERALLY 2 INCHES OR LESS
AT THE HIGHEST ELEVATIONS IN THE WV MOUNTAINS.
TOMORROW WILL FEEL CHILLY COMPARED TO WHAT WE HAVE SEEN IN DECEMBER
SO FAR...BUT IN REALITY WE WILL ONLY BE 5-7 DEGREES BELOW NORMAL
WITH HIGHS IN THE UPPER 30S AND LOWER 40S ACROSS THE LOWLANDS...AND
MID TO UPPER 30S IN THE MOUNTAINS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
LOW LEVEL MOISTURE ERODES THROUGH THE DAY TUESDAY...WITH THE LAST OF
THE UPSLOPE POPS DISINTEGRATING WITHIN THE FIRST 6 HOURS. EXPECT
FAIRLY RAPID CLEARING WITH STRONG RADIATIONAL COOLING TUESDAY NIGHT
UNDER A CLEAR SKY...CALM WIND...AND LOW DEWPOINTS. HIGH PRESSURE TO
DOMINATE THROUGH MID WEEK WITH SLOW RECOVERY TO THE TEMPERATURES IN
THE COLDER AIRMASS. UPPER TROUGH AXIS TO PASS WEDNESDAY WITH LITTLE
FANFARE...AND ONLY ACKNOWLEDGE THIS WITH A MODEST CLOUD COVER BUMP
OVER THE FAR NORTHERN ZONES.
OPTED FOR THE LOWER SIDE OF GUIDANCE IN DEWPOINTS AND TEMPERATURES
IN THE COLDER AIRMASS BEYOND TUESDAY. THIS IS ESPECIALLY TRUE FOR
THE OVERNIGHT PERIODS TUESDAY AND WEDNESDAY WHERE VALUES WERE MORE
AGGRESSIVELY DROPPED.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
TRIED TO KEEP MOUNTAIN VALLEYS COLDER THAN HPC GUIDANCE FOR THURSDAY
NIGHT...FIGURING WARMING MAINLY ALOFT AND STILL LIGHT WINDS...TO
ALLOW INVERSION TO SET UP.
ANOTHER NICE DECEMBER DAY EXPECTED ON FRIDAY. PROBABLY THE WARMEST
AFTERNOON TEMPERATURES OF THIS EXTENDED PERIOD.
WAS A BIT SLOWER INCREASING POPS SATURDAY AFTERNOON AND
EVENING...BUT AGAIN LOOKS TO BE RAIN. WILL INCREASE POPS TO LIKELY
FOR OVERNIGHT SATURDAY NIGHT.
HARD TO DETERMINE HOW LONG THE DEEP MOISTURE HOLDS IN ON SUNDAY.
BUT SOME COLDER AIR FINALLY LEAKS IN AGAIN SUNDAY NIGHT...DO MENTION
SOME SNOW SHOWERS SUNDAY NIGHT IN THE MOUNTAINS.
AS IS A FREQUENT PROBLEM IN WINTER...DAY 7 CONFIDENCE IS LOW...BUT
DID STAY A BIT COLDER THAN GUIDANCE...FIGURING ON 850 TEMPS STILL
NEAR OR SLIGHTLY BELOW ZERO CELSIUS.
&&
.AVIATION /00Z MONDAY THROUGH SATURDAY/...
A COLD FRONT WILL PULL OFF TO THE EAST...LEAVING LOW CLOUDS AND
NORTHWESTERLY WINDS BEHIND IT. SOME PATCHY LIGHT RAIN WILL CONTINUE
THIS EVENING...POSSIBLY CHANGING TO SNOW BEFORE ENDING. CLOUDS WILL
GRADUALLY LIFT ON TUESDAY...AND THEN DISSIPATE LATER IN THE DAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF LIFTING CLOUDS COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY H H H H H H H M M H H H
HTS CONSISTENCY H M H H H H H H H H H H
BKW CONSISTENCY M M M H H H H H H H H H
EKN CONSISTENCY M L M H H H M M M M M L
PKB CONSISTENCY M M M 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...
NONE.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...MZ/26
NEAR TERM...MZ
SHORT TERM...30
LONG TERM...KTB
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1250 PM EST MON DEC 10 2012
.SYNOPSIS...
A STRONG COLD FRONT DEPARTS TO THE EAST THROUGH THE NIGHT. HIGH PRESSURE
BUILDS MID WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
SURFACE COLD FRONT IS CURRENTLY CROSSING OHIO RIVER...PER OBS AND
RADAR. THE ENHANCED PRECIP BEHIND THE FRONT APPEARS TIED TO THE 925
MB FRONT. BECAUSE OF THIS ENHANCEMENT BEHIND THE SURFACE FRONT DID
DRAW HIGHER POPS A LITTLE FARTHER WEST THAN PREVIOUS FORECAST.
PRECIP OUT AHEAD OF THE FRONT HAS BEEN FAIRLY LIGHT...WITH LIGHT
RAIN OR EVEN JUST SOME MIST/SPRINKLES BEING REPORTED BY ASOS/S
ACROSS THE FORECAST AREA. HAVE SEEN SOME LIGHTNING JUST WEST AND
NORTH OF OUR CWA...AGAIN IT SEEMS TIED MOST CLOSELY TO THE 925 FRONT
AND UPPER LEVEL ENHANCEMENT PROVIDED BY A VORT MAX RIDING UP THE
FRONT. THAT VORT MAX HAS MOVED OFF THE NORTHEAST AND HAVE NOT SEEN
ANY LIGHTNING FOR ABOUT AN HOUR...HOWEVER RAP SHOWING ANOTHER VORT
MAX SHOULD RIDE NE ALONG THE FRONT THIS AFTERNOON...SO TRIED TO TIE
SOME SLIGHT CHANCE THUNDER TO THE 925 FRONT AND 500MB VORT MAX
COMBINATION. REALLY SHOULD NOT BE MORE THAN SOME RANDOM STRIKES
THROUGH THE AFTERNOON. MOST LOCATIONS ACROSS WV AT OR NEAR THEIR
HIGH FOR THE DAY...WITH FALLING TEMPERATURES ALREADY SHOWING UP
BEHIND THE FRONT IN SE OHIO. EXPECT A QUICK 5-10 DEGREE DROP IN THE
HOUR TO TWO AFTER THE FRONT PASSES...WITH A SLOWER COOLING TREND
AFTER THAT INTO TONIGHT. LAV GUIDANCE SEEMED FAIRLY CLOSE TO CURRENT
TRENDS...SO USED THAT AS A STARTING POINT FOR TODAYS NON-DIURNAL
CURVE.
PRECIPITATION WILL SLOWLY COME TO AN END OVERNIGHT FROM WEST TO EAST
AS THE SYSTEM MOVES EAST AND HIGH PRESSURE BEGINS TO BUILD TO THE
WEST. AS COOLER TEMPERATURES ALOFT MOVE IN...WILL SEE A TRANSITION
FROM RAIN TO SNOW JUST AS THE PRECIP IS MOVING OUT. SHOULD NOT SEE
ANY ACCUMULATIONS IN THE LOWLANDS...WITH GENERALLY 2 INCHES OR LESS
AT THE HIGHEST ELEVATIONS IN THE WV MOUNTAINS.
TOMORROW WILL FEEL CHILLY COMPARED TO WHAT WE HAVE SEEN IN DECEMBER
SO FAR...BUT IN REALITY WE WILL ONLY BE 5-7 DEGREES BELOW NORMAL
WITH HIGHS IN THE UPPER 30S AND LOWER 40S ACROSS THE LOWLANDS...AND
MID TO UPPER 30S IN THE MOUNTAINS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
LOW LEVEL MOISTURE ERODES THROUGH THE DAY TUESDAY...WITH THE LAST OF
THE UPSLOPE POPS DISINTEGRATING WITHIN THE FIRST 6 HOURS. EXPECT
FAIRLY RAPID CLEARING WITH STRONG RADIATIONAL COOLING TUESDAY NIGHT
UNDER A CLEAR SKY...CALM WIND...AND LOW DEWPOINTS. HIGH PRESSURE TO
DOMINATE THROUGH MID WEEK WITH SLOW RECOVERY TO THE TEMPERATURES IN
THE COLDER AIRMASS. UPPER TROUGH AXIS TO PASS WEDNESDAY WITH LITTLE
FANFARE...AND ONLY ACKNOWLEDGE THIS WITH A MODEST CLOUD COVER BUMP
OVER THE FAR NORTHERN ZONES.
OPTED FOR THE LOWER SIDE OF GUIDANCE IN DEWPOINTS AND TEMPERATURES
IN THE COLDER AIRMASS BEYOND TUESDAY. THIS IS ESPECIALLY TRUE FOR
THE OVERNIGHT PERIODS TUESDAY AND WEDNESDAY WHERE VALUES WERE MORE
AGGRESSIVELY DROPPED.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
SFC HIGH PRESSURE CENTER PROGGED TO BE LOCATED TO THE EAST OF AREA
OVER THE MID-ATLANTIC SEABOARD THURSDAY AND FRIDAY WITH
SOUTH/SOUTHWESTERLY FLOW IN PLACE. AS SUCH...A WARMING TREND UNDER
MOSTLY SUNNY SKIES WILL BEGIN AFTER A RELATIVELY COOL TUE AND
WED...WITH MAX TEMPS THU INTO THE LOWER 50S LOWLANDS AND INTO THE
MID AND UPPER 50S BY FRIDAY. BY SATURDAY EXTENDED OPERATIONAL NWP
BEGINS TO DIVERGE ON THE HANDLING OF A SYSTEM PROGGED TO EJECT OUT
OF THE ROCKIES. THE ECMWF TAKES A MORE NORTHEASTERLY TRACK TOWARDS
THE UPPER MIDWEST AND BECOMES CLOSED IN THE PROCESS...WHILE THE GFS
REMAINS OPEN AT UPPER LEVELS AND IS MORE EASTERLY IN ITS COURSE AND
MORE PROGRESSIVE. IN SHORT...THE EURO KEEPS THE FORECAST AREA DRY
SATURDAY WITH FEWER CLOUDS WHILE THE GFS IS MUCH MORE CLOUDY AND
BRINGS IN PRECIP BY AT LEAST MIDDAY SATURDAY. VARIOUS ENSEMBLES SEEM
TO AT LEAST LOOSELY SUPPORT THE EURO SOLUTION AND THUS WILL LEAN THE
FORECAST IN THAT DIRECTION. HAVE CODED MAINLY UPPER 50S LOWLANDS
FOR SATURDAY...BUT WITH 925MB TEMPS AROUND 9-10C IF THE EURO SOLUTION
FULLY PANS OUT TEMPS WOULD LIKELY CLIMB INTO THE LOWER 60S. HAVE
ALSO INCLUDED A SLIGHT CHANCE OF RAIN SHOWERS FOR SATURDAY TO
ACCOUNT FOR UNCERTAINTY IN THE GFS TRACK BUT LEANED THE HIGHER LOW/MID
CHANCE POPS BEGINNING SATURDAY NIGHT AND SUNDAY.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
COLD FRONT WILL MOVE ACROSS THE CWA THIS AFTERNOON INTO TONIGHT.
CURRENTLY ITS RUNNING FROM KPKB TO KHTS. WILL SEE S/SW WINDS SHIFT
TO NW AS THE FRONT PASSES...WITH SOME GUSTS UP TO ABOUT 20KTS
EXPECTED. SEEING SOME ENHANCED PRECIP BEHIND THE FRONT...OR ACTUALLY
IN LINE WITH THE FRONT AT 925MB. WILL SEE LIGHT RAIN CONTINUE AHEAD
OF THE FRONT...WITH HEAVIER MVFR SHOWERS ALONG AND BEHIND THE FRONT.
WILL ALSO SEE IFR CEILINGS MOVE IN ALONG AND BEHIND THE
FRONT...GRADUALLY IMPROVING BACK TO MVFR THEN VFR TOMORROW. DID HAVE
SOME LIGHTNING TIED TO A VORT MAX RIDING UP THE 925 FRONT
EARLIER...AND RAP SHOWING ANOTHER VORT MAX SHOULD MOVE THROUGH THIS
AFTERNOON...SO CONTINUED THE IDEA OF SOME VCTS/CB THIS AFTERNOON
WITH THAT FEATURE. WITH THAT SAID...THUNDER SHOULD BE FAIRLY RANDOM
AND ISOLATED...SO WAS ON THE FENCE TO EVEN INCLUDE IT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF RESTRICTIONS IN SHOWERS COULD VARY.
VCTS/CB MAY NOT MATERIALIZE THIS AFTERNOON.
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 H M H H H H H H
HTS CONSISTENCY H H H H H M M H H H H H
BKW CONSISTENCY H M H H M H H M H H H H
EKN CONSISTENCY H H H H H H H M H H H H
PKB CONSISTENCY H H H H H M M H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z TUESDAY...
NONE.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...MZ/26
NEAR TERM...MZ
SHORT TERM...26
LONG TERM...50
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
645 AM EST MON DEC 10 2012
.SYNOPSIS...
SOME SHOWERS WILL LINGER ACROSS PARTS OF THE AREA INTO THIS
AFTERNOON AS A COLD FRONT CONTINUES TO PUSH OFF TO THE EAST.
COLDER AIR FILTERING INTO THE AREA BEHIND THE FRONT WILL LEAD TO
FALLING TEMPERATURES THROUGH THIS AFTERNOON. HIGH PRESSURE WILL
BUILD INTO THE REGION THROUGH MID WEEK...LEADING TO DRIER BUT
COOLER CONDITIONS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT EVIDENT ON RADAR PUSHING SLOWLY EAST...CURRENTLY
SITUATED RIGHT ALONG INTERSTATE 71. WIDESPREAD SHOWERS ARE
CONTINUING OUT AHEAD OF THE FRONT ACROSS SOUTHEASTERN PORTIONS OF
OUR FA. THE FRONT WILL CONTINUE TO PUSH EAST THROUGH THIS
AFTERNOON...BUT THE NAM AND RAP ARE BOTH INDICATING SOME
ADDITIONAL PCPN OVERRUNNING THE FRONT BACK UP ACROSS PORTIONS OF
OUR FA THROUGH THIS AFTERNOON. THE GFS AND ECMWF ARE NOT QUITE AS
AGGRESSIVE WITH THIS BUT THEY TOO ARE AT LEAST HINTING AT THE
POSSIBILITY OF IT. AS A RESULT...WILL ALLOW FOR PCPN TO LINGER
BACK FARTHER TO THE WEST THEN CURRENTLY INDICATED BY THE RADAR
TRENDS. DUE TO THE MODEL DIFFERENCES...THE WESTERN EXTENT OF THIS
IS IN DOUBT THOUGH AND HAVE GENERALLY TRENDED CLOSE TO THE 03Z
SREF WHICH KEEPS LIKELY OR HIGHER POPS PRETTY CLOSE TO ONGOING
PCPN. WILL THEN TAPER BACK TO CHANCE POPS HEADING BACK THE
NORTHWEST TO ACCOUNT FOR THE UNCERTAINTY. DEVELOPING CAA BEHIND
THE FRONT WILL LIKELY ALLOW FOR SOME FALLING TEMPERATURES THROUGH
THIS AFTERNOON. IF PCPN EXTENDS FAR ENOUGH BACK TO THE WEST...WE
COULD END UP WITH A RAIN SNOW MIX ALONG THE WESTERN FRINGE OF THE
PCPN BY LATER THIS AFTERNOON AS THE LOW LEVELS BEGIN TO COOL. THE
NAM AND GFS ARE BOTH TRYING TO INDICATE SOME LIGHT ACCUMULATIONS
BY EVENING ACROSS PARTS OF OUR WEST. HOWEVER...THINK THIS IS
PROBABLY OVERDONE AS THE GROUND TEMPERATURE IS STILL WARM. IN
ADDITION...THE COBB METHOD IS INDICATING MORE OF A RAIN SNOW MIX
WITH NO ACCUMULATION AS SURFACE TEMPERATURES SHOULD AT LEAST
REMAIN ABOVE FREEZING THROUGH THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
CYCLONIC LOW LEVEL FLOW AND CAA WILL CONTINUE INTO THIS EVENING
WITH BOTH THE NAM AND GFS INDICATING A WEAK SURFACE TROUGH
PIVOTING DOWN FROM THE NORTH. THIS MAY BE ENOUGH TO PRODUCE A FEW
LIGHT SNOW SHOWERS OR FLURRIES INTO TONIGHT. LOW LEVEL FLOW WILL
BEGIN TO BACK LATER TONIGHT AS HIGH PRESSURE STARTS TO BUILD
IN FROM THE WEST. THIS SHOULD ALLOW FOR ANY PCPN TO TAPER OFF BY
LATE TONIGHT. HIGH PRESSURE WILL THEN BUILD INTO THE REGION
TUESDAY THROUGH WEDNESDAY...LEADING TO DRY CONDITIONS AND MORE
SEASONABLE TEMPERATURES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
SPRAWLING HIGH PRESSURE WILL BE RUNNING FROM NEW ENGLAND BACK INTO
THE OHIO VALLEY AT THE BEGINNING OF THE PERIOD. THE HIGH WILL
CONTROL THE REGIONS WEATHER INTO FRIDAY.
MODELS HAVE DIVERGED SOME WITH THEIR SOLUTION FOR THE SYSTEM THAT
KICKS OUT OF THE PLAINS FRIDAY INTO SATURDAY. THE GFS IS MUCH WEAKER
AND QUICKER WITH THE SYSTEM AND THEREFORE PUSHES A CDFNT ACROSS THE
FA SATURDAY...WITH COOLER AND DRIER AIR WORKING IN FOR SUNDAY. THE
ECMWF...DGEX AND TO SOME EXTENT THE CMC ARE SLOWER AND DEEPER. THIS
DELAYS THE START OF THE PCPN BY ABOUT 6 HOURS...BUT ALSO DELAYS
FROPA UNTIL SUNDAY. THE GFS LOOKS LIKE THE OUTLIER...SO LEANED
TOWARDS THE CONSENSUS SOLUTION. SO KEPT HIGHER POPS SATURDAY NIGHT
INTO SUNDAY AND WENT WARMER OVERNIGHT LOWS SATURDAY NIGHT.
WITH HIGH OVER THE REGION INTO FRIDAY...THERE SHOULD BE PLENTY OF
SUNSHINE. COULD SEE SOME PERIODS OF AC OR CI AS WEAK S/W WORKS
THROUGH THE H5 FLOW.
A GRADUAL WARMING WILL OCCUR DURING THE LATER HALF OF THE WEEK. ON
WEDNESDAY...HIGHS ARE EXPECTED TO PUSH INTO THE LOWER TO MID 40S.
HIGHS WILL PUSH INTO THE UPPER 40S TO LOWER 50S BY THE END OF THE
WEEK AND OVER THE WEEKEND.
ANOTHER COOL NIGHT IS EXPECTED WEDNESDAY NIGHT WITH TEMPERATURES
FALLING BACK INTO THE 20S BEFORE THE WARMER AIR BEGINS TO WORK IN
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A COLD FRONT HAS PASSED BY ALL THE TERMINALS THIS MORNING LEAVING
NORTHWEST WINDS AROUND 10 KTS. TRICKY PART OF THE FORECAST TODAY
WILL BE CIGS. CIGS FOR THE MOST PART SHOULD REMAIN IFR THROUGHOUT
THE MORNING. SOME MVFR CIGS MAY TRY TO PUSH INTO THE WESTERN
TERMINALS LATE THIS MORNING AS SOME DRIER AIR MOVES INTO THE LOW
LEVELS. LIGHT RAIN/DRIZZLE IS FORECAST TO CONTINUE ALONG AND SOUTH
OF THE I-71 CORRIDOR THROUGHOUT THE MORNING AND INTO THE EARLY
AFTERNOON. AFTER THAT...THERE MAY BE A BRIEF PERIOD THIS AFTERNOON
WHERE ALL TERMINALS BECOME DRY AND HAVE CIGS RAISE TO MVFR.
HOWEVER...THIS WILL BE SHORT LIVED. WRAPAROUND MOISTURE FROM LOW
PRESSURE TO OUR NORTHEAST WILL BRING CIGS DOWN TO NEAR IFR
CATEGORY THIS EVENING ACROSS MOST TERMINALS. THE ONLY EXCEPTION
FOR THESE LOWER CIGS MAY BE KCVG/KLUK...FARTHER FROM THE LOW.
AS THE WRAPAROUND MOISTURE MOVES INTO THE AREA THIS
EVENING...LIGHT SNOW SHOWERS WILL BECOME POSSIBLE MAINLY ACROSS
THE NORTHERN TERMINALS. THESE SHOWERS AND IFR CIGS WILL CONTINUE
INTO THE EARLY MORNING HOURS TUESDAY. MODELS ARE INDICATING THAT
CIGS MAY FINALLY GO VFR JUST BEFORE SUNRISE TUESDAY MORNING.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL
SHORT TERM...JGL
LONG TERM...SITES
AVIATION...LATTO
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
357 AM EST MON DEC 10 2012
.SYNOPSIS...
SOME SHOWERS WILL LINGER ACROSS PARTS OF THE AREA INTO THIS
AFTERNOON AS A COLD FRONT CONTINUES TO PUSH OFF TO THE EAST.
COLDER AIR FILTERING INTO THE AREA BEHIND THE FRONT WILL LEAD TO
FALLING TEMPERATURES THROUGH THIS AFTERNOON. HIGH PRESSURE WILL
BUILD INTO THE REGION THROUGH MID WEEK...LEADING TO DRIER BUT
COOLER CONDITIONS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT EVIDENT ON RADAR PUSHING SLOWLY EAST...CURRENTLY
SITUATED RIGHT ALONG INTERSTATE 71. WIDESPREAD SHOWERS ARE
CONTINUING OUT AHEAD OF THE FRONT ACROSS SOUTHEASTERN PORTIONS OF
OUR FA. THE FRONT WILL CONTINUE TO PUSH EAST THROUGH THIS
AFTERNOON...BUT THE NAM AND RAP ARE BOTH INDICATING SOME
ADDITIONAL PCPN OVERRUNNING THE FRONT BACK UP ACROSS PORTIONS OF
OUR FA THROUGH THIS AFTERNOON. THE GFS AND ECMWF ARE NOT QUITE AS
AGGRESSIVE WITH THIS BUT THEY TOO ARE AT LEAST HINTING AT THE
POSSIBILITY OF IT. AS A RESULT...WILL ALLOW FOR PCPN TO LINGER
BACK FARTHER TO THE WEST THEN CURRENTLY INDICATED BY THE RADAR
TRENDS. DUE TO THE MODEL DIFFERENCES...THE WESTERN EXTENT OF THIS
IS IN DOUBT THOUGH AND HAVE GENERALLY TRENDED CLOSE TO THE 03Z
SREF WHICH KEEPS LIKELY OR HIGHER POPS PRETTY CLOSE TO ONGOING
PCPN. WILL THEN TAPER BACK TO CHANCE POPS HEADING BACK THE
NORTHWEST TO ACCOUNT FOR THE UNCERTAINTY. DEVELOPING CAA BEHIND
THE FRONT WILL LIKELY ALLOW FOR SOME FALLING TEMPERATURES THROUGH
THIS AFTERNOON. IF PCPN EXTENDS FAR ENOUGH BACK TO THE WEST...WE
COULD END UP WITH A RAIN SNOW MIX ALONG THE WESTERN FRINGE OF THE
PCPN BY LATER THIS AFTERNOON AS THE LOW LEVELS BEGIN TO COOL. THE
NAM AND GFS ARE BOTH TRYING TO INDICATE SOME LIGHT ACCUMULATIONS
BY EVENING ACROSS PARTS OF OUR WEST. HOWEVER...THINK THIS IS
PROBABLY OVERDONE AS THE GROUND TEMPERATURE IS STILL WARM. IN
ADDITION...THE COBB METHOD IS INDICATING MORE OF A RAIN SNOW MIX
WITH NO ACCUMULATION AS SURFACE TEMPERATURES SHOULD AT LEAST
REMAIN ABOVE FREEZING THROUGH THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
CYCLONIC LOW LEVEL FLOW AND CAA WILL CONTINUE INTO THIS EVENING
WITH BOTH THE NAM AND GFS INDICATING A WEAK SURFACE TROUGH
PIVOTING DOWN FROM THE NORTH. THIS MAY BE ENOUGH TO PRODUCE A FEW
LIGHT SNOW SHOWERS OR FLURRIES INTO TONIGHT. LOW LEVEL FLOW WILL
BEGIN TO BACK LATER TONIGHT AS HIGH PRESSURE STARTS TO BUILD
IN FROM THE WEST. THIS SHOULD ALLOW FOR ANY PCPN TO TAPER OFF BY
LATE TONIGHT. HIGH PRESSURE WILL THEN BUILD INTO THE REGION
TUESDAY THROUGH WEDNESDAY...LEADING TO DRY CONDITIONS AND MORE
SEASONABLE TEMPERATURES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
SPRAWLING HIGH PRESSURE WILL BE RUNNING FROM NEW ENGLAND BACK INTO
THE OHIO VALLEY AT THE BEGINNING OF THE PERIOD. THE HIGH WILL
CONTROL THE REGIONS WEATHER INTO FRIDAY.
MODELS HAVE DIVERGED SOME WITH THEIR SOLUTION FOR THE SYSTEM THAT
KICKS OUT OF THE PLAINS FRIDAY INTO SATURDAY. THE GFS IS MUCH WEAKER
AND QUICKER WITH THE SYSTEM AND THEREFORE PUSHES A CDFNT ACROSS THE
FA SATURDAY...WITH COOLER AND DRIER AIR WORKING IN FOR SUNDAY. THE
ECMWF...DGEX AND TO SOME EXTENT THE CMC ARE SLOWER AND DEEPER. THIS
DELAYS THE START OF THE PCPN BY ABOUT 6 HOURS...BUT ALSO DELAYS
FROPA UNTIL SUNDAY. THE GFS LOOKS LIKE THE OUTLIER...SO LEANED
TOWARDS THE CONSENSUS SOLUTION. SO KEPT HIGHER POPS SATURDAY NIGHT
INTO SUNDAY AND WENT WARMER OVERNIGHT LOWS SATURDAY NIGHT.
WITH HIGH OVER THE REGION INTO FRIDAY...THERE SHOULD BE PLENTY OF
SUNSHINE. COULD SEE SOME PERIODS OF AC OR CI AS WEAK S/W WORKS
THROUGH THE H5 FLOW.
A GRADUAL WARMING WILL OCCUR DURING THE LATER HALF OF THE WEEK. ON
WEDNESDAY...HIGHS ARE EXPECTED TO PUSH INTO THE LOWER TO MID 40S.
HIGHS WILL PUSH INTO THE UPPER 40S TO LOWER 50S BY THE END OF THE
WEEK AND OVER THE WEEKEND.
ANOTHER COOL NIGHT IS EXPECTED WEDNESDAY NIGHT WITH TEMPERATURES
FALLING BACK INTO THE 20S BEFORE THE WARMER AIR BEGINS TO WORK IN
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A SWATH OF LIGHT RAIN WILL SLOWLY SLIDE EASTWARD THROUGH THE
EARLY MORNING HOURS. THE MAIN AFFECTS FROM THIS WILL BE OCCASIONAL
MVFR VSBYS ALONG AND SOUTH OF THE I-71 CORRIDOR WITH THE BACK EDGE
ALREADY REACHING KCVG/KILN. A COLD FRONT ABOUT TO PASS KDAY WILL
BRING A WIND SHIFT OUT OF THE NORTHEAST AND A BAND OF IFR CIGS TO
THE AREA. THESE CIGS SHOULD SHIFT EAST AND REACH THE REST OF THE
TERMINALS OVER THE NEXT FEW HOURS. BEHIND THIS BAND OF IFR
CIGS...SOME DRIER AIR SHOULD BREAK THE LOW CLOUD DECK. THIS WILL
ALLOW FOR AN OPPORTUNITY FOR VFR CIGS AT THE WESTERN TERMINALS
KDAY/KCVG/KLUK BEFORE SUNRISE...LASTING INTO THE AFTERNOON. TO THE
EAST...VFR CIGS SHOULD RETURN A LITTLE LATER IN THE MORNING.
ADDITIONAL LIGHT RAIN OVERRUNNING THE ADVANCING FRONT MAY AFFECT
TERMINALS ALONG AND SOUTH OF I-71 THROUGHOUT THE MORNING. BY THE
MID AFTERNOON ALL TERMINALS ARE EXPECTED TO BE DRY. WRAPAROUND
MOISTURE FROM DEPARTING LOW PRESSURE WILL THEN BRING MVFR AND IFR
CIGS TO THE AREA DURING THE EVENING. IN ADDITION...SNOW SHOWERS
WILL ALSO BE POSSIBLE DURING THIS TIME...MAINLY ACROSS THE
NORTHERN TERMINALS.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE MONDAY NIGHT
INTO TUESDAY MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JGL
NEAR TERM...JGL
SHORT TERM...JGL
LONG TERM...SITES
AVIATION...LATTO
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1256 AM EST MON DEC 10 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHEAST OVERNIGHT WHICH WILL DRAG A COLD
FRONT ACROSS THE REGION LATE TONIGHT AND EARLY MONDAY MORNING.
HIGH PRESSURE BUILDING INTO THE CENTRAL PART OF THE COUNTRY WILL
HELP USHER IN DRIER AND COLDER AIR BEHIND THIS FRONT.
&&
.NEAR TERM /THROUGH TODAY/...
SHOWERS HAVE BEEN FILLING IN AS THEY MOVE INTO THE FORECAST AREA
THIS EVENING AHEAD OF AN APPROACHING LOW AND COLD FRONT. ISOLATED
TO SCATTERED EMBEDDED THUNDERSTORMS HAVE ALSO BEEN OCCURRING WITH
THE BETTER COVERAGE IN THE SOUTHWEST COUNTIES. WILL CONTINUE TO
SEE SHOWERS AND THUNDERSTORMS PUSH ACROSS THE REGION OVERNIGHT.
EXPECT MUCH OF THIS ACTIVITY TO DIMINISH CONSIDERABLY AS THE COLD
FRONT MOVES INTO THE AREA LATER TONIGHT.
COLD FRONT WILL BISECT THE REGION AT DAYBREAK AND CONTINUE THROUGH
THE REST OF THE FORECAST AREA EARLY IN THE MORNING. TEMPERATURES
WILL REMAIN QUITE MILD UNTIL FRONTAL PASSAGE WITH READINGS FALLING
THEREAFTER. APPEARS THAT MANY LOCATIONS WILL HAVE A 12Z HIGH AND A
13Z LOW.
12Z HIGH RESOLUTION NAM-ARW HAD SHOWN A SECONDARY WAVE OF
PRECIPITATION BEHIND THE COLD FRONT SPREADING NORTHEAST IN THE
MORNING. PAST FEW RUNS OF THE RAP HAVE LEANED TOWARDS THIS AND 00Z
NAM SHOWS IT TO SOME EXTENT. SO HAVE INCREASED POPS AGAIN DURING
THE MORNING MAINLY SOUTH AND EAST OF I-71. THIS WILL ALL PUSH OFF
TO THE EAST DURING THE AFTERNOON. PRECIPITATION SHOULD ALL BE RAIN
AS COOL DOWN WILL BE GRADUAL AFTER INITIAL SURGE WITH THE FRONT.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
A FEW LINGERING CLOUDS AND THE COLD PUSH DOWNWIND OF LAKE
MICHIGAN COULD SPARK SOME FLURRIES OR A LIGHT SNOW SHOWER EARLY
MONDAY EVENING WITH LITTLE IF ANY NEGATIVE IMPACTS TO THE REGION.
SKIES WILL REMAIN GENERALLY CLOUDY UNTIL LATE TUESDAY WHEN
RELATIVELY WARMER AIR ALOFT IS FOUND ON THE BACK SIDE OF THE
DEPARTING RIDGE OF H8 HIGH PRESSURE. A SURFACE RIDGE OF HIGH
PRESSURE WILL ALSO BECOME MORE ESTABLISHED OVER THE AREA AT THIS
TIME. TEMPERATURES THROUGH THIS TIME WILL BE COLDER BUT VERY NEAR
CLIMATOLOGICAL NORMALS FOR THIS TIME OF YEAR.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
SPRAWLING HIGH PRESSURE WILL BE RUNNING FROM NEW ENGLAND BACK INTO
THE OHIO VALLEY AT THE BEGINNING OF THE PERIOD. THE HIGH WILL
CONTROL THE REGIONS WEATHER INTO FRIDAY.
MODELS HAVE DIVERGED SOME WITH THEIR SOLUTION FOR THE SYSTEM THAT
KICKS OUT OF THE PLAINS FRIDAY INTO SATURDAY. THE GFS IS MUCH WEAKER
AND QUICKER WITH THE SYSTEM AND THEREFORE PUSHES A CDFNT ACROSS THE
FA SATURDAY...WITH COOLER AND DRIER AIR WORKING IN FOR SUNDAY. THE
ECMWF...DGEX AND TO SOME EXTENT THE CMC ARE SLOWER AND DEEPER. THIS
DELAYS THE START OF THE PCPN BY ABOUT 6 HOURS...BUT ALSO DELAYS
FROPA UNTIL SUNDAY. THE GFS LOOKS LIKE THE OUTLIER...SO LEANED
TOWARDS THE CONSENSUS SOLUTION. SO KEPT HIGHER POPS SATURDAY NIGHT
INTO SUNDAY AND WENT WARMER OVERNIGHT LOWS SATURDAY NIGHT.
WITH HIGH OVER THE REGION ON WEDNESDAY INTO FRIDAY...THERE SHOULD BE
PLENTY OF SUNSHINE. COULD SEE SOME PERIODS OF AC OR CI AS WEAK S/W
WORKS THROUGH THE H5 FLOW.
A GRADUAL WARMING WILL OCCUR DURING THE LATER HALF OF THE WEEK. ON
WEDNESDAY...HIGHS ARE EXPECTED TO PUSH INTO THE LOWER TO MID 40S.
HIGHS WILL PUSH INTO THE UPPER 40S TO LOWER 50S BY THE END OF THE
WEEK AND OVER THE WEEKEND.
ANOTHER COOL NIGHT IS EXPECTED WEDNESDAY NIGHT WITH TEMPERATURES
FALLING BACK INTO THE 20S BEFORE THE WARMER AIR BEGINS TO WORK IN
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A SWATH OF LIGHT RAIN WILL SLOWLY SLIDE EASTWARD THROUGH THE
EARLY MORNING HOURS. THE MAIN AFFECTS FROM THIS WILL BE OCCASIONAL
MVFR VSBYS ALONG AND SOUTH OF THE I-71 CORRIDOR WITH THE BACK EDGE
ALREADY REACHING KCVG/KILN. A COLD FRONT ABOUT TO PASS KDAY WILL
BRING A WIND SHIFT OUT OF THE NORTHEAST AND A BAND OF IFR CIGS TO
THE AREA. THESE CIGS SHOULD SHIFT EAST AND REACH THE REST OF THE
TERMINALS OVER THE NEXT FEW HOURS. BEHIND THIS BAND OF IFR
CIGS...SOME DRIER AIR SHOULD BREAK THE LOW CLOUD DECK. THIS WILL
ALLOW FOR AN OPPORTUNITY FOR VFR CIGS AT THE WESTERN TERMINALS
KDAY/KCVG/KLUK BEFORE SUNRISE...LASTING INTO THE AFTERNOON. TO THE
EAST...VFR CIGS SHOULD RETURN A LITTLE LATER IN THE MORNING.
ADDITIONAL LIGHT RAIN OVERRUNNING THE ADVANCING FRONT MAY AFFECT
TERMINALS ALONG AND SOUTH OF I-71 THROUGHOUT THE MORNING. BY THE
MID AFTERNOON ALL TERMINALS ARE EXPECTED TO BE DRY. WRAPAROUND
MOISTURE FROM DEPARTING LOW PRESSURE WILL THEN BRING MVFR AND IFR
CIGS TO THE AREA DURING THE EVENING. IN ADDITION...SNOW SHOWERS
WILL ALSO BE POSSIBLE DURING THIS TIME...MAINLY ACROSS THE
NORTHERN TERMINALS.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES POSSIBLE MONDAY NIGHT
INTO TUESDAY MORNING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...FRANKS
LONG TERM...SITES
AVIATION...LATTO
AREA FORECAST DISCUSSION
NWS TULSA OK
505 AM CST MON DEC 10 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 12Z TAFS... VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES
FOR THE 24 HOUR FORECAST PERIOD. MID CLOUDS WILL COVER THE AREA
MOST OF THE DAY... WITH GUSTY NORTHERLY WINDS AT THE SURFACE.
WINDS WILL EASE DURING THE AFTERNOON AND SKIES ARE EXPECTED TO
CLEAR OUT BY EARLY EVENING.
&&
.PREV DISCUSSION... /ISSUED 334 AM CST MON DEC 10 2012/
DISCUSSION...
NARROW BAND OF SNOW CONTINUES TO PROGRESS QUICKLY EASTWARD ACROSS
SOUTHERN OK / NW TX AHEAD OF THE UPPER TROUGH AXIS. SHORT TERM
DATA HAVE ALIGNED STRONG LIFT WITHIN A SATURATED DENDRITIC GROWTH ZONE
NEAR THE RED RIVER...AND RECENT OBS AND REPORTS NEAR KSPS SUPPORT
THIS BRIEF BUT INTENSE SNOWFALL AREA. LATEST RUC DATA SHIFT THE
FRONTOGENETIC FORCING MOST ALIGNED WITHIN THIS ZONE NORTHEASTWARD
WHILE WEAKENING IT OVER THE NEXT 4-6 HOURS. THUS FORECAST WILL
INCLUDE A HIGHER MEASURABLE SNOW POTENTIAL FOR PORTIONS OF FAR SE
OK BUT ANY ACCUMULATIONS ARE EXPECTED TO REMAIN LIGHT. ANY PRECIP
WILL QUICKLY SHIFT EAST OF THE FORECAST AREA BY LATE MORNING.
TEMPS WILL STRUGGLE TO WARM TODAY HOWEVER THE SUN WILL MAKE AN
APPEARANCE WHICH HAS BEEN A RARE SIGHT RECENTLY. VERY COLD TEMPS
TONIGHT WITH LOW DEWPOINTS AND LIGHT WINDS. WHILE NOT CURRENTLY
FORECAST...A FEW LOWS AROUND 10 DEGREES ARE CERTAINLY POSSIBLE.
TEMPS MODERATE BEGINNING TUESDAY AND RETURN ABOVE NORMAL BY
THURSDAY. THE NEXT WAVE TRACKING ACROSS THE SOUTHERN TIER STATES
ARRIVES FRIDAY INTO SATURDAY. WHILE THE TIMING IS IN GENERAL
AGREEMENT AMONGST DATA...THERE ARE TWO MAIN CAMPS REGARDING THE
STRENGTH OF THE WAVE. THE UKMET/ECMWF ARE STRONGER OFFERING A
STOUT CLOSED MID LEVEL LOW...WHILE THE GFS/CANADIAN ARE MORE OPEN
WITH THE WAVE. THE FORECAST WILL MAINTAIN POPS IN THE CHANCE
CATEGORY GIVEN RECENT STRUGGLES TO PRODUCE WIDESPREAD MEANINGFUL
PRECIP...HOWEVER SHOULD THE STRONGER SOLUTION BECOME MORE APPARENT
THEN CHANCES WILL OBVIOUSLY INCREASE.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS TULSA OK
334 AM CST MON DEC 10 2012
.DISCUSSION...
NARROW BAND OF SNOW CONTINUES TO PROGRESS QUICKLY EASTWARD ACROSS
SOUTHERN OK / NW TX AHEAD OF THE UPPER TROUGH AXIS. SHORT TERM
DATA HAVE ALIGNED STRONG LIFT WITHIN A SATURATED DENDRITIC GROWTH ZONE
NEAR THE RED RIVER...AND RECENT OBS AND REPORTS NEAR KSPS SUPPORT
THIS BRIEF BUT INTENSE SNOWFALL AREA. LATEST RUC DATA SHIFT THE
FRONTOGENETIC FORCING MOST ALIGNED WITHIN THIS ZONE NORTHEASTWARD
WHILE WEAKENING IT OVER THE NEXT 4-6 HOURS. THUS FORECAST WILL
INCLUDE A HIGHER MEASURABLE SNOW POTENTIAL FOR PORTIONS OF FAR SE
OK BUT ANY ACCUMULATIONS ARE EXPECTED TO REMAIN LIGHT. ANY PRECIP
WILL QUICKLY SHIFT EAST OF THE FORECAST AREA BY LATE MORNING.
TEMPS WILL STRUGGLE TO WARM TODAY HOWEVER THE SUN WILL MAKE AN
APPEARANCE WHICH HAS BEEN A RARE SIGHT RECENTLY. VERY COLD TEMPS
TONIGHT WITH LOW DEWPOINTS AND LIGHT WINDS. WHILE NOT CURRENTLY
FORECAST...A FEW LOWS AROUND 10 DEGREES ARE CERTAINLY POSSIBLE.
TEMPS MODERATE BEGINNING TUESDAY AND RETURN ABOVE NORMAL BY
THURSDAY. THE NEXT WAVE TRACKING ACROSS THE SOUTHERN TIER STATES
ARRIVES FRIDAY INTO SATURDAY. WHILE THE TIMING IS IN GENERAL
AGREEMENT AMONGST DATA...THERE ARE TWO MAIN CAMPS REGARDING THE
STRENGTH OF THE WAVE. THE UKMET/ECMWF ARE STRONGER OFFERING A
STOUT CLOSED MID LEVEL LOW...WHILE THE GFS/CANADIAN ARE MORE OPEN
WITH THE WAVE. THE FORECAST WILL MAINTAIN POPS IN THE CHANCE
CATEGORY GIVEN RECENT STRUGGLES TO PRODUCE WIDESPREAD MEANINGFUL
PRECIP...HOWEVER SHOULD THE STRONGER SOLUTION BECOME MORE APPARENT
THEN CHANCES WILL OBVIOUSLY INCREASE.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 36 20 47 25 / 10 0 0 0
FSM 40 20 47 23 / 10 0 0 0
MLC 38 16 47 20 / 20 0 0 0
BVO 37 13 48 19 / 10 0 0 0
FYV 35 14 42 17 / 10 0 0 0
BYV 36 18 44 22 / 10 0 0 0
MKO 37 16 46 20 / 10 0 0 0
MIO 35 16 46 22 / 10 0 0 0
F10 37 18 46 22 / 10 0 0 0
HHW 42 19 48 22 / 40 0 0 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
LONG TERM....07
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
533 PM EST MON DEC 10 2012
.SYNOPSIS...
A COLD FRONT WILL TRAVERSE THE REGION LATE TODAY AND TONIGHT. WET
WEATHER WILL CONTINUE INTO THIS EVENING...THEN COLDER AND DRIER
CONDITIONS MOVE IN FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LIGHT RAIN AND DRIZZLE AHEAD OF APPROACHING COLD FRONT WILL
CONTINUE THROUGH THE AFTERNOON AND INTO THIS EVENING. SHARP YET
SLOW MOVING COLD FRONT FOR LATE AFTERNOON/EVENING WILL BRING A
WIND SHIFT TO THE WEST AND A FEW HOURS AFTER THAT PRECIP SHOULD
SHUT DOWN FOR MOST LOCATIONS /ABOUT 03-06Z/. EXCEPTION WILL BE
HIGHER TERRAIN OF THE WEST...WHERE PRECIP WILL LINGER AS SNOW
SHOWERS TONIGHT - LIKELY PRODUCING A COATING OF SNOW. COLDER AIR
EVENTUALLY WORKS IN OVERNIGHT...IMPACTING NW MTNS FIRST...BUT WILL
TAKE A GOOD PORTION OF THE OVERNIGHT TO REACH THE LOWER SUSQ. AIR
STILL NOT FORMIDABLE FOR DECEMBER THOUGH...AS THESE READINGS
REMAIN WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
HIGH PRESSURE BEGINS TO BUILD IN LATE TONIGHT INTO TUE AS
CONDITIONS IMPROVE BACK TO VFR BY TUES MORNING FOR MOST...POSS TUE
AFT IN THE HIGHER TERRAIN.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
HIGH PRESSURE NOSES IN PRETTY QUICKLY TUESDAY SHUTTING DOWN
WHATEVER SNOW SHOWERS THAT ARE ONGOING IN THE WEST...AND BEGINNING
A PROLONGED PERIOD OF RATHER BRIGHT AND FAIR WEATHER.
HIGHS IN THE 30S AND 40S WILL AVERAGE A FEW DEG EITHER SIDE OF
NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
ALL MODEL GUIDANCE SHOWS A LARGE AREA OF HIGH PRESSURE DOMINATING
THE REGIONAL WEATHER PATTERN THROUGH FRIDAY...SUPPORTING A HIGH
CONFIDENCE FCST OF FAIR WEATHER AND LGT WINDS. WITH THE BENEFIT OF
MSUNNY SKIES...DAYTIME HIGHS SHOULD REMAIN NEAR TO SLIGHTLY ABOVE
NORMAL. HOWEVER...OVERNIGHT LOWS SHOULD BE NEAR DECEMBER NORMS DUE
TO THE CLEAR SKIES/CALM WIND.
LOW PRESSURE WILL EJECT NEWD FROM THE S/CNTRL PLAINS THEN AFFECT
THE CNTRL-ERN STATES INTO THE WEEKEND. SOME WINTRY PCPN IS PSBL ON
THE NRN SIDE OF THE MSTR SHIELD ASSOC WITH THIS SYSTEM. THERE IS
STILL A HIGH LEVEL OF UNCERTAINTY IN STORM TRACK AND EXACT
LOCATION OF THE RAIN/SNOW LINE...BUT CURRENTLY EXPECT ANY WINTRY
WEATHER TO BE CONFINED TO SOME PORTION OF AN AREA COVERING THE
GRTLKS INTO THE NORTHEAST STATES. STAY TUNED FOR MORE DETAILS ON
POTENTIAL FOR WINTRY WEATHER THIS WEEKEND.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
22Z SFC ANALYSIS SHOWS A COLD FRONT BISECTING PA...RUNNING FROM
ELM SOUTHWARD THRU UNV AND JST. SHIFTING WINDS TO THE NW BEHIND
THE FRONT WILL CAUSE LINGERING MOISTURE TO ASCEND THE ALLEGHENIES...CAUSING
CONTINUED -SRHA AND IFR CIGS AT JST. LATEST RUC SOUNDINGS SUGGEST
A CHANGEOVER TO SNOW AT BFD BY ARND 23Z...WITH A FEW HRS OF IFR
CIGS/VSBYS LIKELY THERE THIS EVENING.
FURTHER EAST...LOW LVL STABLE AIR MASS PERSISTS ACROSS THE SUSQ
VALLEY...WHERE LOW CIGS/FOG ARE REPORTED AT 22Z. HOWEVER...PASSAGE OF
COLD FRONT /ARND 00Z AT IPT AND 02Z-03Z AT MDT AND LNS/ WILL BRING
A WSHIFT TO THE NW WITH RAPIDLY IMPROVING CONDS.
LINGERING MVFR CIGS AND SCT -SHSN MAY PERSIST FROM MIDNIGHT THRU
MIDDAY TUE AT BFD/JST...WHILE DOWNSLOPING NW FLOW LIKELY BRINGS A
RETURN TO VFR CONDS EAST OF THE MTNS.
HIGH PRESSURE WILL BUILD INTO THE REGION BY TUE AFTN...LIKELY
CAUSING ANY LINGERING MVFR STRATOCU TO BREAK UP OVR THE W MTNS.
OUTLOOK...
WED-FRI...MAINLY VFR.
SAT...MVFR POSS IN RAIN SHOWERS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/RXR
NEAR TERM...RXR
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...FITZGERALD/RXR
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
344 PM CST MON DEC 10 2012
.DISCUSSION...
LOW AND MIDLEVEL CLOUDS WERE RAPIDLY DISSIPATING ACROSS THE
MIDSOUTH. NORTHWEST SURFACE WINDS PREVAILED...AROUND THE EASTERN
PERIPHERY OF AN ARCTIC SURFACE PRESSURE RIDGE CENTERED OVER
OKLAHOMA. THIS PRESSURE RIDGE WILL LIFT INTO THE LOWER MS AND OHIO
RIVER VALLEYS ON TUESDAY...PROVIDING LIGHT WINDS AND PRIME
NOCTURNAL RADITIONAL COOLING CONDITIONS THROUGH THURSDAY.
THE LATTER HALF OF THE WEEK WILL SEE LOW LEVEL SOUTHERLY FLOW
RETURN UNDER RIDGING ALOFT. BEST FEED OF GULF MOISTURE WILL REMAIN
OVER TX AND THE SOUTHERN PLAINS ON FRIDAY. THIS LOW LEVEL MOISTURE
AXIS WILLS SHIFT EASTWARD INTO THE MIDSOUTH... AHEAD OF A COMPACT
CLOSED UPPER LOW LIFTING INTO THE MID MS RIVER VALLEY. A TRAILING
COLD FRONT AND MIDLEVEL TROF AXIS WILL PROVIDE A CHANCE OF RAIN
OVER THE MIDSOUTH ON SATURDAY.
THE ECMWF HAS BEEN CONSISTENT IN BRINGING A DEEPER CLOSED LOW
ACROSS THE SOUTHERN PLAINS NEXT MONDAY...AND INTO THE MIDSOUTH ON
TUESDAY. GIVEN THE MUCH GREATER RUN TO RUN CONSISTENCY COMPARED TO
THE GFS...HAVE BASED DAYS 7 AND 8 ON THE ECMWF MODEL.
PWB
&&
.AVIATION...
18Z TAF CYCLE
CIGS ARE LIFTING AS A DRY SLOT MOVES IN FROM THE WEST. HOWEVER...THERE
ARE AN ABUNDANCE OF LOW CLOUDS OVER MISSOURI THAT WILL BEGIN TO
ROTATE INTO THE CWA AFTER 22-23Z. THE RUC KEEPS LOW CLOUDS OVER
THE AREA FOR MUCH OF THE OVERNIGHT PERIOD WITH POSSIBLE CLEARING
BEGINNING AFTER MIDNIGHT ACROSS NE ARKANSAS. THE NAM HAS DRY AIR
FILTERING IN DUE TO THE HIGH PRESSURE BUILDING INTO THE REGION AND
ESSENTIALLY ERODES THE LOW CLOUDS. THUS VFR CONDITIONS WOULD
PREVAIL IF THE NAM IS CORRECT. TOUGH FORECAST AND WITH THIS PACKAGE WILL
LEAN TOWARD THE RUC BUT NOT VERY CONFIDENT. NORTHWEST WINDS OF
10-15 KTS WITH HIGHER GUSTS WILL BEGIN TO DIE DOWN THIS AFTERNOON.
AFTER 00Z...NORTHERLY WINDS AROUND 5 KTS CAN BE EXPECTED.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 25 44 28 51 / 0 0 0 0
MKL 22 43 21 50 / 0 0 0 0
JBR 22 43 23 50 / 0 0 0 0
TUP 24 48 26 52 / 0 0 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1119 AM CST MON DEC 10 2012
.UPDATE... /ISSUED 921 AM CST MON DEC 10 2012/
MIDMORNING UPDATE SENT FOR ADJUSTMENTS TO HOURLY TEMPERATURE
TRENDS AND PRECIP TYPE/CHANCES. A FEW FLURRIES CANNOT BE RULED OUT
OVER NORTHEAST AR...INTO NORTHWEST TN. HOWEVER... WITH DRY
UNDERCUTTING CLOUD BASES AROUND 10KFT... AND MIDLEVEL LIFT EXITING
THE AREA...HAVE PULLED MENTION OF LIGHT WINTRY PRECIP.
OTHER ADJUSTMENTS WERE MADE TO SKY CONDITION... BASED ON 14Z RUC
DELAYED EXIT OF THE LOW CLOUDS. GOES VISIBLE IMAGERY SHOWED A
SOLID 2KFT TO 3KFT LAYER OVER ALL BUT THE NORTHWEST TIP OF MO.
THIS MAY BE SLOWER TO ERODE THAN WHAT THE 12Z NAM SUGGESTS.
PWB
&&
.DISCUSSION... /ISSUED 329 AM CST MON DEC 10 2012/
WEATHER IS RAPIDLY CHANGING ACROSS THE MIDSOUTH. THUNDERSTORMS ARE
EXITING EAST INTO CENTRAL TENNESSEE AND ALABAMA WITH A DRASTICALLY
COLDER AIRMASS APPROACHING EAST ARKANSAS. 3 AM TEMPERATURES RANGE
FROM 63 DEGREES IN NORTHEAST MISSISSIPPI...TO 45 DEGREES IN
NORTHEAST ARKANSAS. HOWEVER FURTHER WEST IN NORTH CENTRAL
ARKANSAS..TEMPERATURES ARE BELOW FREEZING. THIS COLD AIRMASS WILL
MOVE INTO THE MIDSOUTH BY SUNRISE. SOME LOCATIONS ESPECIALLY EAST
OF THE MISSISSIPPI RIVER WILL LIKELY SEE THE WARMEST TEMPERATURES
OF THE DAY BEFORE OR AROUND SUNRISE WITH STEADY OR FALLING
TEMPERATURES DURING THE DAY.
THE NAM REMAINS THE LONE OUTLIER AMONG GUIDANCE BRINGING IN UP TO
AN INCH OF ACCUMULATING SNOWFALL EARLY THIS MORNING THROUGH MIDDAY
TODAY. NO OTHER DATA SOURCE I WAS ABLE TO FIND HINTED AT ANYTHING
MORE THAN TRACE AMOUNTS OF FREEZING OR FROZEN PRECIPITATION. SNOW
HAS DEVELOPED AND IS REACHING THE GROUND IN SOUTH CENTRAL
OKLAHOMA WHERE DEW POINTS ARE IN THE MIDDLE TO UPPER 20S. HOWEVER
FARTHER EAST IN EAST OKLAHOMA WHERE DEW POINTS ARE IN THE
TEENS...NO OBSERVATIONS INDICATE SNOW IS REACHING THE GROUND.
DECIDED TO ONLY MENTION A WINTRY MIX IN NORTHEAST ARKANSAS AND THE
MISSOURI BOOTHEEL FOR A FEW HOURS THIS MORNING BEFORE THE DRY
AIR MOVES IN BRINGING AN END TO ANY CHANCE OF PRECIP.
BEYOND THE CHANCE OF OUR FIRST WINTRY PRECIPITATION THIS
YEAR...COLD TEMPERATURES WILL BE THE MAIN STORM EARLY THIS WEEK.
WINTER HAS ARRIVED. HIGHS TOMORROW WILL LIKELY REMAIN IN THE 40S
AREA WIDE WITH THE COLDEST LOCATIONS STRUGGLING TO WARM OUT OF THE
LOW 40S. MORNING LOWS TOMORROW MORNING WILL BE IN THE LOW TO
MIDDLE 20S ACROSS MOST OF THE AREA. SKIES WILL BE MOSTLY CLEAR
TUESDAY THROUGH THE END OF THE WORK WEEK WITH DRY CONDITIONS.
TEMPERATURES WILL TREND A FEW DEGREES WARMER EACH DAY WITH HIGHS
APPROACHING THE 60 DEGREE MARK BY FRIDAY.
NEXT WEEKEND...GUIDANCE POINTS TO RAIN RETURNING TO THE MIDSOUTH.
ANOTHER COLD FRONT LOOKS LIKELY LATE SATURDAY OR SUNDAY.
&&
.AVIATION...
18Z TAF CYCLE
CIGS ARE LIFTING AS A DRY SLOT MOVES IN FROM THE WEST. HOWEVER...THERE
ARE AN ABUNDANCE OF LOW CLOUDS OVER MISSOURI THAT WILL BEGIN TO
ROTATE INTO THE CWA AFTER 22-23Z. THE RUC KEEPS LOW CLOUDS OVER
THE AREA FOR MUCH OF THE OVERNIGHT PERIOD WITH POSSIBLE CLEARING
BEGINNING AFTER MIDNIGHT ACROSS NE ARKANSAS. THE NAM HAS DRY AIR
FILTERING IN DUE TO THE HIGH PRESSURE BUILDING INTO THE REGION AND
ESSENTIALLY ERODES THE LOW CLOUDS. THUS VFR CONDITIONS WOULD
PREVAIL IF THE NAM IS CORRECT. TOUGH FORECAST AND WITH THIS PACKAGE WILL
LEAN TOWARD THE RUC BUT NOT VERY CONFIDENT. NORTHWEST WINDS OF
10-15 KTS WITH HIGHER GUSTS WILL BEGIN TO DIE DOWN THIS AFTERNOON.
AFTER 00Z...NORTHERLY WINDS AROUND 5 KTS CAN BE EXPECTED.
KRM
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 46 28 44 29 / 10 0 0 0
MKL 46 23 44 23 / 10 0 0 0
JBR 37 23 42 24 / 10 0 0 0
TUP 53 27 47 29 / 20 0 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1120 AM CST MON DEC 10 2012
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...CEILING BEGINNING TO ERODE OVER THE NORTHWESTERN HALF
OF THE CWA...IMPROVING IN THE MIDDLE VALLEY TO BROKEN AT ABOUT
3500 FT AS WELL. EXPECT THE HIGH MVFR TO HOLD ON FOR A FEW MORE
HOURS IN THE LOWER VALLEY AND NEAR THE COAST. NORTH WINDS WILL
REMAIN STRONG WITH GUSTS IN THE 25 TO 30 KNOT RANGE EXPECTED
THROUGH THE REMAINDER OF THE AFTERNOON...ONLY SLACKENING A BIT
AFTER ABOUT 3 PM.
TONIGHT EXPECT WINDS TO SUBSIDE FAIRLY QUICKLY AND SHIFT MORE
NORTHEASTERLY WITH CIG/VISBY BECOMING VFR...MID CLOUD DECK
POSSIBLE AT AROUND 5000 FT. WINDS SHOULD REMAIN LIGHT OVERNIGHT
PICKING UP TO ABOUT 10 TO 15 KNOTS BY MID MORNING TOMORROW OUT OF
THE NORTH TO NORTHEAST WITH VFR EXPECTED. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 954 AM CST MON DEC 10 2012/
DISCUSSION...FRESHENED UP FORECAST PACKAGE FOLLOWING FROPA. FRONT
HAS CLEARED ALL BUT THE SOUTHEASTERNMOST MARINE ZONES. STRONG COLD
AIR ADVECTION ONGOING ACROSS THE REGION WITH TEMPS AND DEWPOINTS
DROPPING. WINDS ARE ESSENTIALLY REMAINING IN LINE WITH WIND GUSTS
OF 30 TO 35 MPH CONTINUING IN THE VALLEY...AND SLOWLY DECREASING
AS YOU MOVE NORTH. EXPECT VERY WINDY CONDITIONS TO CONTINUE RIGHT
ALONG THE COAST AND WILL CONTINUE THE WIND ADVISORY THERE. STRONG
WINDS CONTINUE TO BE REPORTED OVER THE LAGUNA AND COASTAL
WATERS...AND 12Z RAOB ANALYSIS 850MB AND LOW LEVEL COLD AIR
ADVECTION UNDERWAY EXPECT THAT WILL CONTINUE FOR AT LEAST THE NEXT
4 TO 5 HOURS BEFORE DROPPING CLOSER TO THE 20 TO 25 KNOT RANGE
LATE THIS AFTERNOON/EARLY THIS EVENING. TEMPERATURES TONIGHT LOOK
ON TRACK IN THE MID 40S SOUTH...UPPER 30S NORTH BUT THAT WILL BE A
PRIMARY FOCUS OF THE UPCOMING FORECAST PACKAGE. THE AMOUNT OF DRY
AIR WORKING IN...WITH THE MID TEENS DEWPOINTS IN WEST CENTRAL TEXAS
MAY LEAD TO A DOWNWARD ADJUSTMENT IN TONIGHTS LOWS ONCE A CLEARER
PICTURE ON CLOUD COVER DEVELOPS. FOR NOW LOW TO MID CLOUD DECK
CONTINUES JUST BEHIND THE FRONT. WITH LIGHT FRONTAL OVERRUNNING
OCCURRING FROM ABOUT 4 TO 14KFT. WITH THAT ALSO CONTINUED A SLIGHT
CHANCE FOR STRATIFORM RAIN AT TIMES...BUT WITH NO REAL REINFORCING
WAVE TO INCREASE MID AND LOWER LEVEL OMEGA DO NOT EXPECT LARGE
AREAS OR HEAVY PRECIP TO FORM THROUGH THE REST OF THE DAY AND THE
AFTERNOON...WITH MOST OF OUR MEASURABLE PRECIP PROBABLY OVER FOR
THE DAY. UPDATED PACKAGE/ZONES ALREADY OUT. /68-JGG/
PREV DISCUSSION... /ISSUED 626 AM CST MON DEC 10 2012/
DISCUSSION...AFTER GETTING A LOOK AT CONDITIONS UPSTREAM AND THE
LATEST RAP DATA MADE SLIGHT UPTICKS TO THE WIND FORECAST WHICH
NECESSITATED UPGRADING THE LAGUNA MADRE TO GALE WARNING THROUGH MID
AFTERNOON FOR FREQUENT GALE FORCE GUSTS AND HOISTING A WIND
ADVISORY FOR COASTAL AREAS THROUGH MID AFTERNOON. NO OTHER CHANGES
AT THIS TIME. /68-JGG/
PREV DISCUSSION... /ISSUED 554 AM CST MON DEC 10 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...THE LATEST SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE VFR/MVFR CONDITIONS OVER DEEP SOUTH TEXAS. CURRENTLY THE
COLD FRONT IS LOCATED FROM SOUTH OF KBKS AND KHBV TO KAPY AND WILL
MOVE ACROSS THE RIO GRANDE VALLEY AROUND 14Z. THE LIGHT WINDS HAVE
ALLOWED SOME MVFR CIGS/VIS TO DEVELOP AHEAD OF FRONT...THIS WILL
BE SHORT LIVED. SHOWERS AND ISOLATED THUNDERSTORMS ARE ALSO A
POSSIBILITY WITH BETTER CHANCES FROM KMFE EASTWARD. NORTH WINDS
WILL DEVELOP BEHIND THE FRONT AND QUICKLY INCREASING TO 20 TO 25
KT WITH GUSTS TO AROUND 30 BY MID MORNING THROUGH THE AFTERNOON.
CIGS WILL SLOWLY RAISE THROUGH THE DAY BUT SHOULD REMAIN MVFR
THROUGH MID TO LATE AFTERNOON.
PREV DISCUSSION... /ISSUED 425 AM CST MON DEC 10 2012/
SHORT TERM /TODAY THROUGH TUESDAY/...THE COLD FRONT CURRENTLY
LOCATED FROM CORPUS CHRISTI TO ALICE TO LAREDO WILL SWEEP THROUGH
DEEP SOUTH TEXAS THIS MORNING. THE LATEST SURFACE OBSERVATIONS AND
MODEL GUIDANCE INDICATES THAT THE FRONT WILL MOVE THROUGH THE AREA A
LITTLE FASTER. MADE MINOR ADJUSTMENTS TO THE TIMING OF THE FRONT...
WHICH WILL MOVE ACROSS THE NORTHERN COUNTIES IN THE NEXT TWO HOURS
AND THROUGH THE LOWER VALLEY BY MID MORNING. CURRENT BROWNSVILLE
WSR-88D SHOWS LITTLE CONVECTION ACROSS DEEP SOUTH TEXAS BUT ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS ARE STILL EXPECTED THIS
MORNING. MUCH COOLER TODAY WITH HIGH TEMPERATURES ALMOST 30 DEGREES
COOLER THAN YESTERDAY. HIGH TEMPERATURES TODAY WILL OCCUR THIS
MORNING THEN TEMPERATURES WILL HOLD STEADY FOR A FEW HOURS BEFORE
DECREASING THIS AFTERNOON. BREEZY NORTH WINDS WILL OCCUR IN THE WAKE
OF THE FRONT AND CONTINUE THROUGH THE DAY. OVERNIGHT LOW
TEMPERATURES FOR TONIGHT WILL FALL INTO THE UPPER 30S OVER THE
NORTHERN AREAS AND IN THE LOWER 40S IN THE VALLEY AND ALONG THE
COAST. HIGH TEMPERATURES FOR TUESDAY WILL BE IN THE 60S.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...BENIGN CONDITIONS WILL
CONTINUE TUESDAY NIGHT THROUGH WEDNESDAY NIGHT AS SURFACE HIGH
PRESSURE COMBINES WITH A VERY DRY ATMOSPHERE IN THE WAKE OF THE COLD
FRONT MENTIONED ABOVE. ISOLATED SHOWERS WILL DEVELOP THURSDAY...AND
CONTINUE THROUGH FRIDAY...AS A DEVELOPING ONSHORE FLOW PUMPS DEEPER
MOISTURE INTO DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY...AND
INTERACTS WITH A SERIES OF WEAK MID-LEVEL DISTURBANCES PASSING
OVERHEAD IN THE WEST-SOUTHWEST TO EAST-NORTHEAST 500 MB FLOW. A
BRIEF RESPITE IN THE PRECIPITATION MAY OCCUR FRIDAY NIGHT BEFORE
BEGINNING AGAIN SATURDAY...AND LASTING THROUGH SUNDAY...DUE TO THE
SLOW PASSAGE OF A WEAK COLD FRONT. BELOW NORMAL TEMPERATURES EARLY
IN THE LONG TERM PERIOD WILL QUICKLY RETURN TO ABOVE NORMAL LEVELS
DUE TO THE RE-DEVELOPING ONSHORE FLOW.
MARINE...TODAY THROUGH TUESDAY...THE COLD FRONT WILL MOVE THROUGH
THE LOWER TEXAS COASTAL WATERS LATER THIS MORNING RESULTING IN
VERY STRONG NORTH WINDS CONTINUING THROUGH THIS AFTERNOON. A GALE
WARNING IS IN EFFECT THROUGH THIS AFTERNOON FOR THE GULF WATERS
EAST OF PADRE ISLAND. SMALL ADVISORY CONDITIONS ARE LIKELY ON THE
LAGUNA MADRE THROUGH THIS AFTERNOON. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS THE LOWER TEXAS COASTAL
WATERS TODAY. SMALL CRAFT ADVISORY CONDITIONS WILL CONTINUE THIS
EVENING THROUGH EARLY TUESDAY MORNING ON THE GULF WATERS. HIGH
PRESSURE SETTLES OVER THE AREA IN THE WAKE OF THE FRONT.
TUESDAY NIGHT THROUGH SUNDAY...GENERALLY MODERATE WINDS AND SEAS
ARE LARGELY EXPECTED THROUGH THE PERIOD...AS AN ONSHORE FLOW RE-
DEVELOPS AND THEN PREVAILS. SMALL CRAFT MAY NEED TO EXERCISE
CAUTION FOR THE GULF OF MEXICO WATERS EAST OF PADRE ISLAND FROM
TUESDAY NIGHT THROUGH SATURDAY. THE APPROACH AND PASSAGE OF A WEAK
COLD FRONT SATURDAY NIGHT WILL BRING A SLIGHT DECREASE IN WINDS
AND SEAS FOR THAT TIME AND THROUGH SUNDAY.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR TXZ251-256-257.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM CST THIS EVENING FOR
GMZ130-132-135.
GALE WARNING UNTIL 2 PM CST THIS AFTERNOON FOR GMZ130-132-135.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 4 AM CST TUESDAY
FOR GMZ150-155-170-175.
GALE WARNING UNTIL 6 PM CST THIS EVENING FOR GMZ150-155-170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/54
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
954 AM CST MON DEC 10 2012
.DISCUSSION...FRESHENED UP FORECAST PACKAGE FOLLOWING FROPA. FRONT
HAS CLEARED ALL BUT THE SOUTHEASTERNMOST MARINE ZONES. STRONG COLD
AIR ADVECTION ONGOING ACROSS THE REGION WITH TEMPS AND DEWPOINTS
DROPPING. WINDS ARE ESSENTIALLY REMAINING IN LINE WITH WIND GUSTS
OF 30 TO 35 MPH CONTINUING IN THE VALLEY...AND SLOWLY DECREASING
AS YOU MOVE NORTH. EXPECT VERY WINDY CONDITIONS TO CONTINUE RIGHT
ALONG THE COAST AND WILL CONTINUE THE WIND ADVISORY THERE. STRONG
WINDS CONTINUE TO BE REPORTED OVER THE LAGUNA AND COASTAL
WATERS...AND 12Z RAOB ANALYSIS 850MB AND LOW LEVEL COLD AIR
ADVECTION UNDERWAY EXPECT THAT WILL CONTINUE FOR AT LEAST THE NEXT
4 TO 5 HOURS BEFORE DROPPING CLOSER TO THE 20 TO 25 KNOT RANGE
LATE THIS AFTERNOON/EARLY THIS EVENING. TEMPERATURES TONIGHT LOOK
ON TRACK IN THE MID 40S SOUTH...UPPER 30S NORTH BUT THAT WILL BE A
PRIMARY FOCUS OF THE UPCOMING FORECAST PACKAGE. THE AMOUNT OF DRY
AIR WORKING IN...WITH THE MID TEENS DEWPOINTS IN WEST CENTRAL TEXAS
MAY LEAD TO A DOWNWARD ADJUSTMENT IN TONIGHTS LOWS ONCE A CLEARER
PICTURE ON CLOUD COVER DEVELOPS. FOR NOW LOW TO MID CLOUD DECK
CONTINUES JUST BEHIND THE FRONT. WITH LIGHT FRONTAL OVERRUNNING
OCCURRING FROM ABOUT 4 TO 14KFT. WITH THAT ALSO CONTINUED A SLIGHT
CHANCE FOR STRATIFORM RAIN AT TIMES...BUT WITH NO REAL REINFORCING
WAVE TO INCREASE MID AND LOWER LEVEL OMEGA DO NOT EXPECT LARGE
AREAS OR HEAVY PRECIP TO FORM THROUGH THE REST OF THE DAY AND THE
AFTERNOON...WITH MOST OF OUR MEASURABLE PRECIP PROBABLY OVER FOR
THE DAY. UPDATED PACKAGE/ZONES ALREADY OUT. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 626 AM CST MON DEC 10 2012/
DISCUSSION...AFTER GETTING A LOOK AT CONDITIONS UPSTREAM AND THE
LATEST RAP DATA MADE SLIGHT UPTICKS TO THE WIND FORECAST WHICH
NECESSITATED UPGRADING THE LAGUNA MADRE TO GALE WARNING THROUGH MID
AFTERNOON FOR FREQUENT GALE FORCE GUSTS AND HOISTING A WIND
ADVISORY FOR COASTAL AREAS THROUGH MID AFTERNOON. NO OTHER CHANGES
AT THIS TIME. /68-JGG/
PREV DISCUSSION... /ISSUED 554 AM CST MON DEC 10 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...THE LATEST SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE VFR/MVFR CONDITIONS OVER DEEP SOUTH TEXAS. CURRENTLY THE
COLD FRONT IS LOCATED FROM SOUTH OF KBKS AND KHBV TO KAPY AND WILL
MOVE ACROSS THE RIO GRANDE VALLEY AROUND 14Z. THE LIGHT WINDS HAVE
ALLOWED SOME MVFR CIGS/VIS TO DEVELOP AHEAD OF FRONT...THIS WILL
BE SHORT LIVED. SHOWERS AND ISOLATED THUNDERSTORMS ARE ALSO A
POSSIBILITY WITH BETTER CHANCES FROM KMFE EASTWARD. NORTH WINDS
WILL DEVELOP BEHIND THE FRONT AND QUICKLY INCREASING TO 20 TO 25
KT WITH GUSTS TO AROUND 30 BY MID MORNING THROUGH THE AFTERNOON.
CIGS WILL SLOWLY RAISE THROUGH THE DAY BUT SHOULD REMAIN MVFR
THROUGH MID TO LATE AFTERNOON.
PREV DISCUSSION... /ISSUED 425 AM CST MON DEC 10 2012/
SHORT TERM /TODAY THROUGH TUESDAY/...THE COLD FRONT CURRENTLY
LOCATED FROM CORPUS CHRISTI TO ALICE TO LAREDO WILL SWEEP THROUGH
DEEP SOUTH TEXAS THIS MORNING. THE LATEST SURFACE OBSERVATIONS AND
MODEL GUIDANCE INDICATES THAT THE FRONT WILL MOVE THROUGH THE AREA A
LITTLE FASTER. MADE MINOR ADJUSTMENTS TO THE TIMING OF THE FRONT...
WHICH WILL MOVE ACROSS THE NORTHERN COUNTIES IN THE NEXT TWO HOURS
AND THROUGH THE LOWER VALLEY BY MID MORNING. CURRENT BROWNSVILLE
WSR-88D SHOWS LITTLE CONVECTION ACROSS DEEP SOUTH TEXAS BUT ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS ARE STILL EXPECTED THIS
MORNING. MUCH COOLER TODAY WITH HIGH TEMPERATURES ALMOST 30 DEGREES
COOLER THAN YESTERDAY. HIGH TEMPERATURES TODAY WILL OCCUR THIS
MORNING THEN TEMPERATURES WILL HOLD STEADY FOR A FEW HOURS BEFORE
DECREASING THIS AFTERNOON. BREEZY NORTH WINDS WILL OCCUR IN THE WAKE
OF THE FRONT AND CONTINUE THROUGH THE DAY. OVERNIGHT LOW
TEMPERATURES FOR TONIGHT WILL FALL INTO THE UPPER 30S OVER THE
NORTHERN AREAS AND IN THE LOWER 40S IN THE VALLEY AND ALONG THE
COAST. HIGH TEMPERATURES FOR TUESDAY WILL BE IN THE 60S.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...BENIGN CONDITIONS WILL
CONTINUE TUESDAY NIGHT THROUGH WEDNESDAY NIGHT AS SURFACE HIGH
PRESSURE COMBINES WITH A VERY DRY ATMOSPHERE IN THE WAKE OF THE COLD
FRONT MENTIONED ABOVE. ISOLATED SHOWERS WILL DEVELOP THURSDAY...AND
CONTINUE THROUGH FRIDAY...AS A DEVELOPING ONSHORE FLOW PUMPS DEEPER
MOISTURE INTO DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY...AND
INTERACTS WITH A SERIES OF WEAK MID-LEVEL DISTURBANCES PASSING
OVERHEAD IN THE WEST-SOUTHWEST TO EAST-NORTHEAST 500 MB FLOW. A
BRIEF RESPITE IN THE PRECIPITATION MAY OCCUR FRIDAY NIGHT BEFORE
BEGINNING AGAIN SATURDAY...AND LASTING THROUGH SUNDAY...DUE TO THE
SLOW PASSAGE OF A WEAK COLD FRONT. BELOW NORMAL TEMPERATURES EARLY
IN THE LONG TERM PERIOD WILL QUICKLY RETURN TO ABOVE NORMAL LEVELS
DUE TO THE RE-DEVELOPING ONSHORE FLOW.
MARINE...TODAY THROUGH TUESDAY...THE COLD FRONT WILL MOVE THROUGH
THE LOWER TEXAS COASTAL WATERS LATER THIS MORNING RESULTING IN
VERY STRONG NORTH WINDS CONTINUING THROUGH THIS AFTERNOON. A GALE
WARNING IS IN EFFECT THROUGH THIS AFTERNOON FOR THE GULF WATERS
EAST OF PADRE ISLAND. SMALL ADVISORY CONDITIONS ARE LIKELY ON THE
LAGUNA MADRE THROUGH THIS AFTERNOON. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS THE LOWER TEXAS COASTAL
WATERS TODAY. SMALL CRAFT ADVISORY CONDITIONS WILL CONTINUE THIS
EVENING THROUGH EARLY TUESDAY MORNING ON THE GULF WATERS. HIGH
PRESSURE SETTLES OVER THE AREA IN THE WAKE OF THE FRONT.
TUESDAY NIGHT THROUGH SUNDAY...GENERALLY MODERATE WINDS AND SEAS
ARE LARGELY EXPECTED THROUGH THE PERIOD...AS AN ONSHORE FLOW RE-
DEVELOPS AND THEN PREVAILS. SMALL CRAFT MAY NEED TO EXERCISE
CAUTION FOR THE GULF OF MEXICO WATERS EAST OF PADRE ISLAND FROM
TUESDAY NIGHT THROUGH SATURDAY. THE APPROACH AND PASSAGE OF A WEAK
COLD FRONT SATURDAY NIGHT WILL BRING A SLIGHT DECREASE IN WINDS
AND SEAS FOR THAT TIME AND THROUGH SUNDAY.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR TXZ251-256-257.
GM...SMALL CRAFT ADVISORY FOR WINDS FROM 2 PM THIS AFTERNOON TO 6 PM
CST THIS EVENING FOR GMZ130-132-135.
GALE WARNING UNTIL 2 PM CST THIS AFTERNOON FOR GMZ130-132-135.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 4 AM CST TUESDAY
FOR GMZ150-155-170-175.
GALE WARNING UNTIL 6 PM CST THIS EVENING FOR GMZ150-155-170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/54
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
626 AM CST MON DEC 10 2012
.DISCUSSION...AFTER GETTING A LOOK AT CONDITIONS UPSTREAM AND THE
LATEST RAP DATA MADE SLIGHT UPTICKS TO THE WIND FORECAST WHICH
NECESSITATED UPGRADING THE LAGUNA MADRE TO GALE WARNING THROUGH MID
AFTERNOON FOR FREQUENT GALE FORCE GUSTS AND HOISTING A WIND
ADVISORY FOR COASTAL AREAS THROUGH MID AFTERNOON. NO OTHER CHANGES
AT THIS TIME. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 554 AM CST MON DEC 10 2012/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...THE LATEST SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE VFR/MVFR CONDITIONS OVER DEEP SOUTH TEXAS. CURRENTLY THE
COLD FRONT IS LOCATED FROM SOUTH OF KBKS AND KHBV TO KAPY AND WILL
MOVE ACROSS THE RIO GRANDE VALLEY AROUND 14Z. THE LIGHT WINDS HAVE
ALLOWED SOME MVFR CIGS/VIS TO DEVELOP AHEAD OF FRONT...THIS WILL
BE SHORT LIVED. SHOWERS AND ISOLATED THUNDERSTORMS ARE ALSO A
POSSIBILITY WITH BETTER CHANCES FROM KMFE EASTWARD. NORTH WINDS
WILL DEVELOP BEHIND THE FRONT AND QUICKLY INCREASING TO 20 TO 25
KT WITH GUSTS TO AROUND 30 BY MID MORNING THROUGH THE AFTERNOON.
CIGS WILL SLOWLY RAISE THROUGH THE DAY BUT SHOULD REMAIN MVFR
THROUGH MID TO LATE AFTERNOON.
PREV DISCUSSION... /ISSUED 425 AM CST MON DEC 10 2012/
SHORT TERM /TODAY THROUGH TUESDAY/...THE COLD FRONT CURRENTLY
LOCATED FROM CORPUS CHRISTI TO ALICE TO LAREDO WILL SWEEP THROUGH
DEEP SOUTH TEXAS THIS MORNING. THE LATEST SURFACE OBSERVATIONS AND
MODEL GUIDANCE INDICATES THAT THE FRONT WILL MOVE THROUGH THE AREA A
LITTLE FASTER. MADE MINOR ADJUSTMENTS TO THE TIMING OF THE FRONT...
WHICH WILL MOVE ACROSS THE NORTHERN COUNTIES IN THE NEXT TWO HOURS
AND THROUGH THE LOWER VALLEY BY MID MORNING. CURRENT BROWNSVILLE
WSR-88D SHOWS LITTLE CONVECTION ACROSS DEEP SOUTH TEXAS BUT ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS ARE STILL EXPECTED THIS
MORNING. MUCH COOLER TODAY WITH HIGH TEMPERATURES ALMOST 30 DEGREES
COOLER THAN YESTERDAY. HIGH TEMPERATURES TODAY WILL OCCUR THIS
MORNING THEN TEMPERATURES WILL HOLD STEADY FOR A FEW HOURS BEFORE
DECREASING THIS AFTERNOON. BREEZY NORTH WINDS WILL OCCUR IN THE WAKE
OF THE FRONT AND CONTINUE THROUGH THE DAY. OVERNIGHT LOW
TEMPERATURES FOR TONIGHT WILL FALL INTO THE UPPER 30S OVER THE
NORTHERN AREAS AND IN THE LOWER 40S IN THE VALLEY AND ALONG THE
COAST. HIGH TEMPERATURES FOR TUESDAY WILL BE IN THE 60S.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...BENIGN CONDITIONS WILL
CONTINUE TUESDAY NIGHT THROUGH WEDNESDAY NIGHT AS SURFACE HIGH
PRESSURE COMBINES WITH A VERY DRY ATMOSPHERE IN THE WAKE OF THE COLD
FRONT MENTIONED ABOVE. ISOLATED SHOWERS WILL DEVELOP THURSDAY...AND
CONTINUE THROUGH FRIDAY...AS A DEVELOPING ONSHORE FLOW PUMPS DEEPER
MOISTURE INTO DEEP SOUTH TEXAS AND THE RIO GRANDE VALLEY...AND
INTERACTS WITH A SERIES OF WEAK MID-LEVEL DISTURBANCES PASSING
OVERHEAD IN THE WEST-SOUTHWEST TO EAST-NORTHEAST 500 MB FLOW. A
BRIEF RESPITE IN THE PRECIPITATION MAY OCCUR FRIDAY NIGHT BEFORE
BEGINNING AGAIN SATURDAY...AND LASTING THROUGH SUNDAY...DUE TO THE
SLOW PASSAGE OF A WEAK COLD FRONT. BELOW NORMAL TEMPERATURES EARLY
IN THE LONG TERM PERIOD WILL QUICKLY RETURN TO ABOVE NORMAL LEVELS
DUE TO THE RE-DEVELOPING ONSHORE FLOW.
MARINE...TODAY THROUGH TUESDAY...THE COLD FRONT WILL MOVE THROUGH
THE LOWER TEXAS COASTAL WATERS LATER THIS MORNING RESULTING IN
VERY STRONG NORTH WINDS CONTINUING THROUGH THIS AFTERNOON. A GALE
WARNING IS IN EFFECT THROUGH THIS AFTERNOON FOR THE GULF WATERS
EAST OF PADRE ISLAND. SMALL ADVISORY CONDITIONS ARE LIKELY ON THE
LAGUNA MADRE THROUGH THIS AFTERNOON. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS THE LOWER TEXAS COASTAL
WATERS TODAY. SMALL CRAFT ADVISORY CONDITIONS WILL CONTINUE THIS
EVENING THROUGH EARLY TUESDAY MORNING ON THE GULF WATERS. HIGH
PRESSURE SETTLES OVER THE AREA IN THE WAKE OF THE FRONT.
TUESDAY NIGHT THROUGH SUNDAY...GENERALLY MODERATE WINDS AND SEAS
ARE LARGELY EXPECTED THROUGH THE PERIOD...AS AN ONSHORE FLOW RE-
DEVELOPS AND THEN PREVAILS. SMALL CRAFT MAY NEED TO EXERCISE
CAUTION FOR THE GULF OF MEXICO WATERS EAST OF PADRE ISLAND FROM
TUESDAY NIGHT THROUGH SATURDAY. THE APPROACH AND PASSAGE OF A WEAK
COLD FRONT SATURDAY NIGHT WILL BRING A SLIGHT DECREASE IN WINDS
AND SEAS FOR THAT TIME AND THROUGH SUNDAY.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR TXZ251-256-257.
GM...SMALL CRAFT ADVISORY FOR WINDS FROM 2 PM THIS AFTERNOON TO 6 PM
CST THIS EVENING FOR GMZ130-132-135.
GALE WARNING UNTIL 2 PM CST THIS AFTERNOON FOR GMZ130-132-135.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 4 AM CST TUESDAY
FOR GMZ150-155-170-175.
GALE WARNING UNTIL 6 PM CST THIS EVENING FOR GMZ150-155-170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/54
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
556 PM CST TUE DEC 11 2012
.SHORT TERM...TONIGHT
555 PM CST TUE DEC 11 2012
LATEST 11.22Z RAP AND 11.18Z NAM/WRF SHOW THAT STRONG 900-800 MB
FRONTOGENESIS IS LOCATED ALONG THE INTERSTATE 90 CORRIDOR. THIS
COINCIDES WITH THE DENDRITIC GROWTH ZONE WITH UP TO .4 MICROBAR
PER SECOND LIFT. THIS WILL GREATLY ENHANCE THE SNOW RATIOS ACROSS
THE AREA EARLY THIS EVENING. WITH SNOW RATIOS OF 15-20 TO 1 AT
TIMES. WITH THIS IN MIND RAISED THE SNOW TOTALS UP TO AN INCH OF
SNOW. AS THE SHORT WAVE ALONG THE INTERSTATE 35 CORRIDOR SLIDES
EAST ACROSS THE AREA...THE SUBSIDENCE BEHIND THIS WAVE WILL CAUSE
A DRAMATIC DECREASE IN THE LOW LEVEL MOISTURE...THUS...BRINGING AN
END TO THE SNOW.
.LONG TERM...SATURDAY THROUGH TUESDAY
300 PM CST TUE DEC 11 2012
11.00Z AND 11.12Z MEDIUM RANGE MODELS FOR SAT SHOWING IMPROVED
AGREEMENT FROM THEIR 10.00Z/10.12Z RUNS. STILL SOME TIMING/STRENGTH
DIFFERENCES WITH THE SHORTWAVE TO LIFT NORTHEAST ACROSS THE MID/
UPPER MS VALLEY. THIS NOT UNEXPECTED WITH THE TRACK OF THIS
SHORTWAVE BEING DRIVEN BY ONE OR MORE KICKER WAVES APPROACHING THE
WEST COAST OR MOVING INTO THE WEST SIDE OF THE LONGWAVE TROUGH.
SOMEWHAT BETTER RUN-TO-RUN CONSISTENCY TO ECMWF SAT. BY SUN THRU
TUE...MODELS ALL OVER THE BOARD WITH SHORTWAVE DETAILS IN THE FLOW
ACROSS NOAM. SOME CONSENSUS FOR A LONGWAVE TROUGH TO BE SLOWLY
PROGRESSING EAST ACROSS NOAM WITH ANOTHER APPROACHING THE WEST COAST
BY TUE. PERHAPS SOME BETTER RUN-TO-RUN CONSISTENCY BY THE ECMWF IN
THE SUN-TUE TIME PERIOD...BUT EVEN THAT LEAVES QUITE A BIT TO BE
DESIRED. LONG-TERM FCST CONFIDENCE AVERAGE SAT...THEN ON THE LOW
SIDE SUN-TUE.
IMPROVED MODEL CONSISTENCY BRINGS ANOTHER PRECIP EVENT TO THE AREA
SAT WITH -RA OR -SN LOOKING LIKELY. MODEL DETAIL DIFFERENCES FOR
SAT AT THIS POINT CENTER ON THE LOW LEVEL THERMAL PROFILES AND WHERE
THE RAIN-SNOW LINE/PRECIP TYPES WOULD END UP AS THE SYSTEM MOVES
ACROSS. GFS/ECMWF HAVE WHAT WOULD BE THE RAIN-SNOW TRANSITION
ROUGHLY ALONG I-90. THIS IS 4 DAYS OUT AND A LOT CAN CHANGE WITH THE
MODEL DETAILS OVER THE NEXT SEVERAL RUNS AS THEY COME INTO
FOCUS/TIGHTER CONSENSUS. THOSE LOCATIONS WHERE THE PRECIP MAY FALL
AS ALL SNOW COULD SEE 3 TO 6 INCHES. SFC AND/OR MID LEVEL TROUGH
TRENDS SLOW TO EXIT WITH LIGHT SNOW/FLURRIES LOOKING TO CONTINUE
INTO SUN. WITH GFS/ECMWF AT ODDS BY MON/TUE...EITHER
APPROACHING/PASSING SHORTWAVE RIDGE OR TROUGH...MODEL/ENSEMBLE
CONSENSUS DATA IN THE FCST GRIDS BY MON/TUE LOOKS GOOD FOR NOW. ALL
MODELS SHOW THE ARCTIC AIR REMAINS UP NEAR AK OR THE OTHER SIDE OF
THE POLE THRU THE MIDDLE OF NEXT WEEK. EVEN WITH SOME SNOWCOVER...
TEMPS FOR DAYS 4-7 LOOK TO REMAIN NEAR TO A BIT ABOVE NORMAL. THIS
WELL TRENDED IN THE MODEL CONSENSUS MAX/MIN TEMP GRIDS.
&&
.AVIATION...TONIGHT AND WEDNESDAY
555 PM CST TUE DEC 11 2012
A BAND OF LIGHT SNOW WILL BE FOUND ALONG THE INTERSTATE 90
CORRIDOR THIS EVENING. THIS SNOW WILL REDUCE VISIBILITIES TO
2-4 MILES AT KRST THROUGH 12.02Z...AND WILL OCCASIONALLY REDUCE
THEM INTO THE 3-5SM THROUGH 12.04Z. CEILINGS WILL BE IN THE 1500
TO 2500 FOOT RANGE IN THE SNOW BAND...AND THEN RISE TO 4K FEET
WHEN THE SNOW ENDS.
PLAN ON VFR CONDITIONS AFTER MIDNIGHT WITH ALTOSTRATUS/CIRROSTRATUS
AOA 15KFT FILLING IN FROM THE WEST. THIS IS IN ADVANCE OF A FAIRLY
DEEP LOW MOVING OUT OF THE MONTANA ROCKIES INTO THE NORTHERN
PLAINS. WINDS WILL ALSO SWITCH AROUND/PICK UP FROM THE SOUTH AFTER
10Z AS THE PRESSURE GRADIENT INCREASES AHEAD OF THE LOW. STILL
CONTEPLATING ADDING LLWS INTO THE TAFS AFTER 14Z AS SOUNDINGS
SHOW A STRONG INVERSION IN THE 1.5-2KFT LAYER WITH SOUTHWEST WINDS
AROUND 40-45KT ABOVE THE INVERSION. WILL TAKE ANOTHER LOOK AT THIS IN
THE 12.00Z MODELS...AND MAY ADD IT TO THE 12.06Z TAFS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
555 PM CST TUE DEC 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....RRS
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
333 PM CST MON DEC 10 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
332 PM CST MON DEC 10 2012
AT 3 PM...LOW CLOUDS PERSISTED ACROSS MUCH OF THE FORECAST AREA.
THIS MOISTURE WAS TRAPPED BELOW A SUBSIDENCE INVERSION. THE
VISIBLE AND FOG PRODUCT /11-3.9 MICRON CHANNEL/ SHOW THAT THE
CLOUDS ARE STARTING TO BREAK UP IN THE DODGE CENTER...AUSTIN...
CHARLES CITY AREAS. THE RAP SEEMS TO BE HANDLING THIS THE BEST.
THEY SHOW THAT A NARROW AREA OF CLEARING WILL MOVE EAST ACROSS
NORTHEAST IOWA AND SOUTHEAST MINNESOTA THIS EVENING. THIS AREA
REMAINS NARROW DUE TO ANOTHER AREA OF CLOUDS MOVING INTO THE
REGION FROM THE DAKOTAS. THIS CLEARING WILL ALLOW A RAPID DROP IN
TEMPERATURES DUE TO FRESH SNOW AND LIGHT WINDS...AND THEN THE
TEMPERATURES WILL RISE AS THE CLOUDS MOVE BACK INTO THE AREA.
ON TUESDAY AFTERNOON AND EVENING...A SHORT WAVE TROUGH WILL MOVE
ACROSS THE AREA. AHEAD OF THIS WAVE...MODERATE 270 TO 280K
ISENTROPIC LEADS TO SATURATION UP TO 775 MB. HOWEVER AS THE WAVE
IS MOVING THROUGH THE REGION...THERE IS VERY LITTLE OMEGA AND THE
LOW LEVEL LAPSE RATES ARE NOT THAT STEEP. AS A RESULT...NOT
EXPECTING ANY ACCUMULATING SNOW. HOWEVER WOULD NOT BE TOO
SURPRISED TO SEE A FEW FLURRIES. SINCE THIS WAVE IS CURRENTLY NOT
PRODUCING ANYTHING UPSTREAM AND THE FORCING AND MOISTURE LOOKS
SIMILAR...DID NOT INCLUDE THEM IN THE FORECAST AT THIS TIME.
ON WEDNESDAY...THE 500 MB FLOW BECOMES ZONAL. THIS KEEPS THE NEXT
2 SHORT WAVE TROUGHS /WEDNESDAY AND THURSDAY/ NEAR THE
U.S./CANADIAN BORDER. BOTH OF THESE SYSTEMS WILL DRAW WARMER AIR
INTO THE REGION. WHILE THE MODELS WERE PUSHING MUCH OF THE AREA
INTO THE 35 TO 45 DEGREE RANGE FOR HIGH TEMPERATURES...LOWERED THEM
A COUPLE OF DEGREES DUE TO THE SNOW PACK.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
332 PM CST MON DEC 10 2012
FROM FRIDAY NIGHT INTO SATURDAY NIGHT...THE MAIN CONCERN WILL BE THE
TRACK OF A SYSTEM MOVING OUT OF THE SOUTHWEST UNITED STATES. AS
THIS SYSTEM MOVES NORTHEAST IT WILL BRING WARM AIR AND GULF
MOISTURE WITH IT. PRECIPITABLE WATER VALUES CLIMB ANYWHERE FROM
150 TO 200 PERCENT OF NORMAL. BOTH THE ECMWF AND GEM HAVE A MUCH
FURTHER NORTH TRACK THAN THE GFS. AS A RESULT...THEY BRING RAIN
INTO SOUTHWEST WISCONSIN AND NORTHEAST IOWA...AND A WINTRY MIX OF
SNOW AND SLEET OR ALL SNOW ACROSS THE REMAINDER OF THE AREA FROM
FRIDAY NIGHT INTO SATURDAY...AND THE PRECIPITATION CHANGES OVER TO
ALL SNOW BEFORE IT ENDS ON SATURDAY NIGHT. MEANWHILE THE GFS IS
ABOUT 6 HOURS SLOWER AND IT ALSO IS FAR ENOUGH SOUTH THAT ONLY THE
AREAS SOUTH OF THE INTERSTATE 90 CORRIDOR WOULD SEE SNOW FROM THIS
SYSTEM. THE GFS ENSEMBLE CONTINUES TO SHOW A WIDESPREAD OF
SOLUTIONS. A FEW OF THEM ARE SIMILAR TO THE ECMWF AND GEM...BUT
THERE ARE ALSO A FEW THAT NO PRECIPITATION AT ALL. OVERALL THE
ECMWF HAS BEEN THE MOST CONSISTENT...SO TRENDED THE FORECAST
TOWARD IT.
&&
.AVIATION...THIS AFTERNOON THROUGH TUESDAY
1130 AM CST MON DEC 10 2012
CIGS/VSBYS WILL CONTINUE TO IMPROVE THIS AFTERNOON AS DRIER HIGH
PRESSURE FROM THE NORTHERN PLAINS BUILDS EAST AND 925-850MB WINDS
GRADUALLY BECOME MORE WESTERLY. THE LOWER LEVEL MVFR/VFR STRATUS
DECKS WILL BE PUSHED EAST AND THE SCT FLURRIES WILL COME TO AN END
AS THE LOWER LEVEL FLOW BECOMES ANTI-CYCLONIC. GOOD VFR BUT COLD
CONDITIONS EXPECTED TONIGHT AS THE HIGH AND A DRY LOW LEVEL AIRMASS
MOVES ACROSS THE AREA. THE HIGH MOVES QUICKLY EAST OF THE AREA ON
TUE. ANOTHER WEAK SFC-500MB TROUGH IS GOING TO SLIDE ACROSS THE
REGION ON TUE. MOISTURE/LIFT INITIALLY LIMITED WITH THIS FEATURE AND
CIGS EXPECTED TO REMAIN VFR THRU TUE MORNING WITH THE INITIALLY DRY
AIRMASS TO OVERCOME. CIGS THEN LOOKING TO DROP TO MVFR TUE
AFTERNOON/EVENING AS THIS TROUGH AXIS PASSES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
332 PM CST MON DEC 10 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
307 AM EST WED DEC 12 2012
.Short Term (Today through Thursday)...
Issued at 245 AM EST Wed Dec 12 2012
Clear skies were noted across the forecast area. This combined with
light winds has allowed good radiational cooling to commence.
Temperatures across the region are currently in the lower to middle
20s and temps should continue to drop through the remainder of the
overnight hours. Have utilized the LMK temperature low temp study
data for lows this morning. Feel that lower 20s will be the rule,
but our typical colder locations will likely drop into the upper
teens.
High pressure at the surface will remain in control of the weather
pattern for today with mostly sunny skies expected. Upper level
currently across Texas will head eastward and pass to our south
today. Mid level heights will rise behind the front which should
allow for temperatures to be a bit warmer than what we saw
yesterday. Generally went close to the weighted model average which
yields afternoon highs in the lower 40s across the northeast
sections and middle 40s across the central and southwest sections.
Overall, this is a little on the cool side of the guidance envelope
for today.
Another clear night is expected tonight with light winds. This
should result in another night of good radiational cooling with
overnight lows dropping back into the lower-middle 20s. Again, our
typical cold spots and valley locations probably will drop back into
the upper teens.
As the next mid level wave drops into the western CONUS on Thursday,
we`ll see another modest rise in mid level heights across the
region. This combined with surface high pressure will result in
another mostly sunny day and milder temperatures. Highs should
range from the mid-upper 40s in the northeast/Bluegrass to the lower
50s in the central and southwest sections.
.Long Term (Thursday Night through Tuesday)...
Issued at 305 AM EST Wed Dec 12 2012
The long term will start out with an elongated area of surface high
pressure stretched along the east coast and southerly winds. Aloft
we will have weak ridging. With this pattern the dry weather will
continue Thursday night and Friday before becoming unsettled once
again.
Friday night into Saturday a low pressure system will move out of
the Plains and into the upper Midwest. Precipitation will begin to
move into the area after midnight Friday. Rain chances will increase
through the day as the system tracks northeast. Rains look to taper
off ahead of the cold frontal passage, which will not be until
Sunday. Will hang on to slight chance to chance pops through Sunday.
Temperatures will start out cold on Friday in the mid 20s to lower
30s. However, with southerly winds and sunny skies, they will
rebound into the lower to mid 50s. For Saturday temps will be
similar, despite more cloud cover and rain as strong warm air
advection will continue. Saturday night through Sunday temperatures
will be a bit trickier and will depend on how fast the cooler air
moves in behind the cold front.
Beyond Sunday the models diverge in their solutions. A couple of
shortwaves and surface lows will cross the area. However, there s
quite a bit of spread in the track and timing of these systems. For
now have leaned toward the ECMWF and toward the previous forecast
for consistency`s sake. This will keep Monday and Monday night dry
before precip moves back in on Tuesday, courtesy of a low passing
south of the forecast area.
Temperatures to start the work week will be cooler than over the
weekend. Highs will be in the 40s with lows in the 30s.
&&
.Aviation (06Z TAF Issuance)...
Issued at 1213 AM EST Wed Dec 12 2012
VFR conditions are expected at all the terminals as surface high
pressure continues to build into the region. Light and variable
winds are expected through the overnight hours. As temperatures
fall overnight, we should see some close T/Td spreads. While the
guidance is still a no go on fog, latest WRF ABI simulated satellite
shows a bit of valley fog developing in the preferred locales.
Latest RUC 13 progs also show some light haze with visibilities
dropping to around 6-7 miles overnight mainly across southern KY.
For now, still plan on keeping things VFR in the upcoming forecast
but will continue to monitor things overnight.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......MJ
Long Term........EER
Aviation.........MJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1213 AM EST WED DEC 12 2012
...Updated Aviation Discussion...
.Forecast Update...
Issued at 950 PM EST Tue Dec 11 2012
Main update for tonight was low temperatures. Many area
observations were already into the mid 20s to lower 30s as of 230Z
which wasn`t too far off from previously forecast min temps.
Therefore, took most locations down a few degrees for tonight, and
took our valley/rural locations down 3-5 degrees as these areas will
really cool off with a good long rad cooling night ahead. Thus,
this puts most locations in the low to mid 20s for lows with our
coldest locations dipping into the upper teens.
Did investigate the possibility for some very light fog overnight
due to the excellent rad cooling, but believe the sfc is a bit too
dry and dewpts will probably start to fall slightly with
temperatures toward sunrise.
&&
.Short Term (Tonight through Wednesday night)...
Issued at 150 PM EST Tue Dec 11 2012
Lingering cloud shield over the Ohio Valley is finally eroding from
west to east, with mostly clear skies west of I-65, and partly to
mostly cloudy farther east. Expect these clouds to be out of the
Bluegrass region around sunset.
The next couple days will be dominated by high pressure, currently
centered Arkansas with the ridge axis extending up through Kentucky
into West Virginia. Pressures will rise in response to a building
upper ridge, but the surface ridge will mainly become more elongated
and not move much at all. As a result, expect favorable radiational
cooling conditions the next 2 nights, with lows in the 20s in most
locations both nights. Progged low-level thicknesses and 850mb temps
support Wednesday max temps at least 6 degrees warmer than today.
Will go out on a limb that we will reach 40 this afternoon, which
puts highs in the mid to upper 40s, which is actually just on the
low end of MOS guidance.
.Long Term (Thursday through Tuesday)...
Issued at 145 PM EST Tue Dec 11 2012
At the start of this period, a strong trough will start to control
west coast, which will promote ridging across the south and
southeast CONUS into Saturday. While our area will be under the
influence of broad and dry southwest flow aloft into late Friday,
the pattern will change and become more active. Guidance continues
to indicate a couple systems ejecting out of the west coast and
moving east through the Ohio Valley Saturday through Tuesday. These
systems are of Pacific origin and never really tap into the colder
air across Canada due to a progged blocking pattern. Forecast
confidence is fairly high through Saturday as models are handling
the first system fairly well.
Surface high pressure will shift east across the Ohio Valley and
settle in the southeastern CONUS by Saturday morning. Surface winds
will transition to southerly and become breezy by Saturday as a
surface low pressure system moves through Kansas, Missouri, and into
northern Illinois. Dry conditions, mostly clear skies, and warming
temperatures are expected through Friday. High temperatures will
warm into the low and mid 50s by Friday.
Clouds and precip chances will increase heading into the weekend as
a low pressure system passes by to the north. Since yesterday, the
GFS solution has trended much closer to the ECMWF and NAEFS mean,
which is why forecast confidence is fairly high through Saturday.
The trailing cold front is projected to sweep through the forecast
area Saturday night into Sunday, with another shot at area-wide rain
showers, perhaps a rumble of thunder with marginal instability.
Temperatures will continue to warm Saturday ahead of the cold front,
which is currently forecast to be our warmest day. Highs in the mid
50s in the north to around 60 degrees in the south appear reasonable
on breezy southerly flow, even with increasing clouds and precip
chances. Temperatures will cool slightly Sunday through Tuesday,
becoming closer to mid-December normals. A brief dry period is
expected late Sunday night through Monday night, as high pressure
and ridging aloft pass through the Ohio Valley. Cloud cover should
start to break up some late Sunday night, but a thin layer of low
stratus could linger just below the inversion.
Models diverge with the second system to cross our area Tuesday,
mainly because there are differences with the progged blocking
pattern across Canada. Spread is noticeable within the ensembles.
Either way, guidance agrees rain chances will increase for Tuesday,
but the devil is in the details. As mentioned in the previous
forecast discussion, this forecast will lean toward the ECMWF
solution. So, it appears a deep and slow moving low pressure system
will track across the central CONUS, with a surface low projected to
slide through the Ohio and Tennessee Valleys late Tuesday.
&&
.Aviation (06Z TAF Issuance)...
Issued at 1213 AM EST Wed Dec 12 2012
VFR conditions are expected at all the terminals as surface high
pressure continues to build into the region. Light and variable
winds are expected through the overnight hours. As temperatures
fall overnight, we should see some close T/Td spreads. While the
guidance is still a no go on fog, latest WRF ABI simulated satellite
shows a bit of valley fog developing in the preferred locales.
Latest RUC 13 progs also show some light haze with visibilities
dropping to around 6-7 miles overnight mainly across southern KY.
For now, still plan on keeping things VFR in the upcoming forecast
but will continue to monitor things overnight.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS
Short Term.......RAS
Long Term........MJP
Aviation.........MJ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1219 AM EST WED DEC 12 2012
.SYNOPSIS...
A FRONTAL BOUNDARY STALLS OVER THE EASTERN CAROLINAS TONIGHT AS
HIGH PRESSURE SLOWLY BUILDS IN FROM THE NORTHWEST. A WAVE OF LOW
PRESSURE WILL DEVELOP ALONG THE FRONT WEDNESDAY...PUSHING FARTHER
OFFSHORE WEDNESDAY NIGHT INTO THURSDAY. HIGH PRESSURE REMAINS IN
PLACE OVER THE MID ATLANTIC THROUGH THE END OF THIS WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
A COLD FRNT INTO ERN NC WHILE HI PRES SLOWLY BLDS IN FROM THE NW.
STRONG LO-LVL INVERSION AND ASSOCIATED MOISTURE WILL KEEP SKIES
MSTLY CLDY THIS EVENG AND OVRNGT...WITH THE LO STRATUS AND HI
TEMP-DEWPT SPREADS PREVENTING FOG FORMATION. STRONG SW FLOW ABOVE
THE INVERSION MAY PROVIDE JUST ENUF (ISENTROPIC) LIFT TO LEAD TO
-RA OVER EXTREME SE VA/NE NC AS MOST MODELS INDICATE...POPS 30% AT
ORF...50% OVER NE NC. LOOKING AT RAP MODEL AND OBSERVATIONS WILL
DELAY THE HIGHER POPS UNTIL AFTER MIDNIGHT AS RAIN ONLY SLOWLY
WORKING NORTHEAST. RAIN CHCS INCREASE TO LIKELY OVER THESE AREAS
INTO WED AS THREAT FOR OVERRUNING PRECIP CONTINUES AND A WAVE OF
LO PRES DEVELOPS ALONG THE STALLED FRNT. TOTAL AMOUNTS SHUD STAY
BLO ONE- QUARTER OF AN INCH DUE TO WEAK LIFT. ONLY A 20% CHC OF
RAIN MAKING IN UP TO RIC/SBY. OTHERWISE...MSTLY CLDY TO CLDY SKIES
FOR THE DAY. LO TEMPS TNGT RANGE FROM THE LWR 30S NW TO LWR 40S
SE...WITH HI TEMPS WED IN THE UPR 40S TO LWR 50S.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
SOME -RA MAY LINGER INTO WED NGT AS LO PRES AND ASSOCIATED FRNTAL
BNDRY PUSH FARTHER OFFSHORE. CONFINED POPS TO SE VA/NE NC AFTER
MIDNGT. DECREASING CLDS AS WELL (TO MSTLY CLR) AS LO TEMPS RANGE
FROM NEAR 30 OVER THE PIEDMONT TO NEAR 40 ALONG THE COAST. ~1030
MB SFC HI PRES BLDS DIRECTLY OVER THE MID-ATLANTIC THU...AND
STAYING PUT INTO FRI. THIS WILL LEAD TO A SNY SKY AND SEASONABLE
TEMPS WITH HIGHS IN THE LWR TO MID 50S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SFC HI PRES INVOF MDATLC STATES FRI NGT IS SLO TO WEAKEN...DRIFT
OFF THE CST SAT. MDT SFC LO PRES TRACKS INTO/THROUGH THE LAKES RGN
SUN INTO MON...PUSHING ASSOCD CDFNT ACRS THE MDATLC RGN. PCPN
PTNTL LOOKS LESS THAN THAT FM PAST CPL DAYS...HAVE CAPPED POPS ABT
30%). DRYING OUT/SEASONABLE WX FM MON AFTN THROUGH TUE. ANOTHER
STORM SYS MAY APPROACH FM THE WSW BY MID NEXT WK.
MILDER SAT...BFR COOLING DOWN (TO AT OR SLGTLY BLO NRML) SUN
THROUGH TUE.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
LOW PRESSURE MOVING NE ALONG THE COAST WILL KEEP THE NE WIND FLOW...
BKN-OVC MVFR CIGS ACROSS SERN TAF SITES THRU MOST OF THIS FCST PRD.
LATEST SUITE OF MODELS INDCT LGHT RAIN OVRSPRDG NE NC CNTYS TOWARD
12Z AND LIFTG NE TOWARD ORF BY 15Z. AIRMASS TO DRY TO THE N TO SPRT
ANY PCPN REACHING THE GRND...ALTHOUGH THERE MAY BE SOME SPRNKLS AT
PHF. ADDED SOME GUSTS UP TO 20 KTS AT ECG/ORF AFTER 12Z DUE TO
TIGHTENING PRES GRDNT.
IMPROVING CNDTNS EXPECTED AFTR 00Z AS LOW PRS PULLS FRTHR OFFSHORE
AND HIGH PRS BUILDS IN BEHIND IT. VFR / DRY WX XPCTD THURS THRU SUN.
&&
.MARINE...
FNTL BNDRY HAS STALLED JUST OFF CSTL CAROLINAS...AND WILL RMN NRLY
STNRY INTO THU. WK SFC LO PRES DVLPS...AND EVENTUALLY TRACKS ENE
ALG THE BNDRY...WHILE MDT SFC HI PRES SETTLES INVOF NE CONUS. THE
RESULT WILL BE A PD OF MDT NNE WNDS (GUSTS TO 25-30 KT
PSBL...HIGHEST ON THE OCN)...AND ASSOCD BUILDING WAVES/SEAS (ESP NR
THE MOUTH OF THE BAY...AND CAPE CHARLES LGT ON S). SCAS WILL RMN
UP ON THE SRN OCN WTRS THROUGH THU...AND WILL RAISE SCAS ON THE
SRN BAY AND SND FOR WED MRNG THROUGH THU. HI PRES EVENTUALLY
BUILDS OVR THE WTRS LT WK...AND WEAKENS ERY IN THE WKND...BRINGING
LWRG WNDS AND WAVES/SEAS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM EST
THURSDAY FOR ANZ632>634-654.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ656-658.
&&
$$
SYNOPSIS...MAS
NEAR TERM...MAS/JAB
SHORT TERM...MAS
LONG TERM...ALB
AVIATION...MPR
MARINE...ALB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1243 AM EST WED DEC 12 2012
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 424 PM EST TUE DEC 11 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
FROM NRN HUDSON BAY INTO THE CNTRL CONUS. WEAK SHORTWAVES MOVING
THROUGH THIS TROUGH HAVE SUPPORTED AREAS OF VERY LIGHT SNOW AND
FLURRIES TODAY. SOUTHERLY CONVERGENT FLOW OFF LAKE MICHIGAN
SUPPORTED A DOMINANT LAKE EFFECT BAND INTO LUCE COUNTY THIS MORNING
AND EARLY AFTERNOON WHICH DROPPED AT LEAST 7 INCHES OF SNOW NEAR
MCMILLAN. THIS BAND HAS SINCE WEAKENED AND MOVED EAST.
MAIN FCST CONCERN TONIGHT IS POSSIBILITY OF MODERATE LAKE EFFECT
SNOW SHOWERS OVER THE NW CWA.
TONIGHT...THE NW ONTARIO TROUGH WILL MOVE EAST AND DRAG A COLD
FRONT INTO WRN LAKE SUPERIOR. THE COLDER AIR ALONG WITH WINDS
VEERING WRLY WILL PROVIDE FAVORABLE CONDITIONS FOR LES INTO THE
KEWEENAW. WITH 850 MB TEMPS DROPPING TO AROUND -15C...INVERSION
HEIGHTS AOA 7K FT...AND LOW LEVEL CONVERGENCE STRENGTHENING DOWNWIND
FROM THE APOSTLE ISLANDS...A MODERATE TO POSSIBLE HEAVY LES BAND IS
EXPECTED TO DEVELOP. SNOWFALL AMOUNTS OF AT LEAST 2 TO 5 INCHES ARE
POSSIBLE...ESPECIALLY IN THE HIGHER TERRAIN FROM TWIN LAKES TO
CALUMET. SINCE MODELS ARE IN FAIRLY GOOD AGREEMENT THAT A HEAVIER
BAND WILL SET UP OVER THIS AREA...HAVE ELECTED TO GO WITH AN
ADVISORY FOR NORTHERN HOUGHTON COUNTY. THERE IS STILL TOO MUCH
UNCERTAINTY TO INCLUDE KEWEENAW OR ONTONAGON IN AN ADVISORY AT THIS
TIME AS IT LOOKS LIKE THEY MAY BE ON THE FRINGE OF WHERE THE HEAVIER
SNOW BAND WILL SET UP. MODEL SNDGS INDICATE SUBSIDENCE WITH QUICKLY
LOWERING INVERSION HEIGHTS AFTER MIDNIGHT SO EXPECT DIMINISHING LES
INTENSITY BY THAT TIME. COLDEST TEMPS TONIGHT SHOULD BE ALONG THE
WISCONSIN BORDER WHERE SINGLE DIGITS COULD BE REACHED UNDER LIGHT
WINDS AND CLEARING SKIES OF SFC RDG. ELSEWHERE EXPECT LOWS TO BE
GENERALLY IN THE TEENS.
WEDNESDAY...THERE COULD BE SOME LINGERING LES OVER THE KEWEENAW
EARLY IN THE DAY BUT OTHERWISE SUBSIDENCE/DRYING AND LOWERING
INVERSION ALONG WITH QUICKLY BACKING FLOW SHOULD QUICKLY END LES.
SHORTWAVE QUICKLY MOVING ACROSS THE US/CANADIAN BORDER LATE IN THE
DAY MAY BRUSH THE NW PART OF LAKE SUPERIOR WITH LIGHT SNOW/FLURRIES
BUT OTHERWISE FORCING INDICATES BETTER CHC OF SNOW WILL STAY NORTH
AND WEST OF THE CWA. INCREASING H925 WINDS TO 35-45 KTS LATE IN
THE DAY ALONG WITH NEUTRAL TO SLIGHLY UNSTABLE TEMPERATURE PROFILE
FM SFC-H9 AND INCREASING PRESSURE FALLS OVR LK SUPERIOR AND INTO
ONTARIO MAY RESULT IN AREAS NEAR LK SUPERIOR OVR NCNTRL AREAS TO
GUST AOA 30 MPH TOWARD EVENING. EXPECT HIGHS IN THE UPR 20S AND
LOWER 30S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 424 PM EST TUE DEC 11 2012
JET STREAK WILL BE PUSHING THROUGH THE NEARLY ZONAL NORTHERN FLOW AT
THE START OF THE PERIOD. THE LEFT FRONT OF THIS 110KT STREAK WILL BE
OVER UPPER MICHIGAN AND AIDING A WEAK 1012MB SFC LOW TRACKING ALONG
THE WARM FRONT ON WEDNESDAY NIGHT. FAIRLY DRY SURFACE TO H850 LAYER
OVER MUCH OF THE LAND CWA...SO DON/T THINK THERE WOULD BE MUCH SNOW
HITTING THE SURFACE EVEN WITH THE STRONG WAA ALOFT. THUS...WILL
LIMIT THE EVENING SLIGHT CHANCES TO THE TIP OF THE KEWEENAW
PENINSULA WITH THE CHANCES OVER NORTHERN LAKE SUPERIOR. THIS FORCING
WILL SHIFT EAST DURING THE OVERNIGHT HOURS AND FOLLOW THE LOW INTO
ONTARIO.
BEFORE THE LOW DEPARTS THERE WILL BE STRONG WINDS ALOFT...ESPECIALLY
ABOVE THE INVERSION WHERE H900 WINDS APPROACH 45-50KTS ON WEDNESDAY
EVENING. BUT BELOW THE INVERSION WINDS ARE LIGHTER AND ONLY APPROACH
30-35KTS. AREA OF HIGHER PRESSURE FALLS OVER THE NORTHERN LAKE
INDICATES THE POTENTIAL FOR GUSTY WINDS ON WEDNESDAY EVENING. WITH
IT OCCURRING AT NIGHT...EXPECT THE SUSTAINED WINDS TO BE
HIGHER...BUT THE GUSTS MORE OCCASIONAL AND THE STRONGEST OVER THE
DOWNSLOPE AREAS OF THE NORTH CENTRAL. LOW LEVEL JET DIMINISHES
THROUGH THE NIGHT WITH THE LOW SHIFTING TO THE NORTHEAST AND EXPECT
THE SURFACE WINDS TO FOLLOW SUIT. THESE NIGHT TIME STRONG LOW LEVEL
JET ABOVE AN INVERSION ARE ALWAYS DIFFICULT TO DETERMINE THE AMOUNT
OF WIND THAT WILL MAKE IT TO THE SURFACE. BUFKIT MOMENTUM TRANSFER
IS USUALLY DECENT AT APPROXIMATE SUSTAINED WINDS/GUSTS...AND BOTH
NAM/GFS SOUNDINGS FOR STDM4 AND EAST BUOY ONLY SHOW A 6HR PERIOD
WEDNESDAY EVENING OF 30-35KTS. WILL LEAVE THE GALE WATCH AS
IS...SINCE HIGHER PLATFORMS WILL LIKELY SEE SOME OF THESE WINDS.
AREA WILL BE SOUTH OF THE TRAILING SURFACE TROUGH ON THURSDAY AND
EXPECT AN ABOVE NORMAL DAY OVER UPPER MICHIGAN. REMAINING
SOUTHERLY FLOW AND A FEW BREAKS IN THE MID CLOUDS SHOULD LEAD
TO ALL OF THE AREAS RISING ABOVE FREEZING DURING THE DAY.
MODELS HAVE THE IDEA OF THE TROUGH SAGGING SOUTH OVER SOUTHERN LAKE
SUPERIOR THURSDAY AFTERNOON AND REMAINING IN PLACE INTO FRIDAY
EVENING. THIS IS IN RESPONSE TO A SHORTWAVE THAT STREAKS THROUGH
THE ZONAL FLOW ON THURSDAY. AS THE TROUGH TRIES TO SAG SOUTH...LOW
LEVEL MOISTURE WILL INCREASE ON THE NORTH SIDE OF IT...BUT THERE IS
LITTLE TO NO CONVERGENCE ALONG THE TROUGH TO SUPPORT PRECIPITATION.
THUS...THE MAIN FORCING MECHANISM COMES FROM UPSLOPE FLOW. WITH THIS
SURFACE TROUGH STALLING OVER THE AREA...THE LOW LEVEL FLOW IS VERY
COMPLICATED AND UNCERTAIN AND MAKES PINPOINTING THE LIGHT
PRECIPITATION VERY DIFFICULT. SINCE THE TOP OF THE CLOUDS ARE
AROUND -8C AT 4KFT...DON/T EXPECT THERE TO BE MANY ICE CRYSTALS
IN THE CLOUDS AND REMOVE THE SNOW MENTION AND JUST GO WITH
DRIZZLE OR FREEZING DRIZZLE. LIGHT WESTERLY FLOW WOULD
FAVOR IT TO BE MAINLY OVER THE KEWEENAW ON THURSDAY AFTERNOON.
AFTER THAT...THERE ARE NO STRONG INDICATIONS ON WIND DIRECTIONS AND
WILL KEEP IT HIGHLIGHTED TO THE KEWEENAW FOR MUCH OF THE PERIOD
SINCE THEY WOULD HAVE MORE OPPORTUNITIES WITH THE VARIED WIND
DIRECTIONS. IN ADDITION...PICKED OUT A FEW LOCALIZED AREAS IN THE
NORTH CENTRAL TO HIGHLIGHT A SLIGHT CHANCE OF FREEZING
DRIZZLE BASED ON CONSENSUS WIND DIRECTIONS.
MODELS IN MUCH BETTER AGREEMENT THAN YESTERDAY HEADING INTO THE
WEEKEND...WITH THE GFS SHIFTING TOWARDS THE ECMWF/UKMET/GEM
SOLUTION. BUT...WITH THE INTERACTION OF SEVERAL DIFFERENT WAVES BY
THE TIME IT GETS HERE LEADS TO SOME UNCERTAINTY. THAT BEING
SAID...WITH THE CONSISTENCY OF THE ECMWF OVER THE LAST COUPLE DAYS
AND IT/S SUPERIOR SATELLITE BASED INITIALIZATION...WOULD WANT TO
LEAN TOWARDS THAT IDEA. WITH THE CURRENT TRACK...MUCH OF THE CWA
WILL SEE MEASURABLE...BUT LIGHT SNOW DUE TO THE BROAD AREA OF
CIRCULATION. BEST CHANCES WILL BE OVER THE SOUTHEAST HALF OF THE
CWA AND CLOSER TO THE LOW TRACK AND ALSO OVER NORTH CENTRAL UPPER
MICHIGAN WHERE UPSLOPE FLOW MAY INCREASE AMOUNTS. WITH THE ZONAL
FLOW IN PLACE AHEAD OF THIS WAVE...THERE WON/T BE MUCH COLD AIR TO
WORK WITH AND THAT LIMITS ANY LAKE ENHANCED POTENTIAL DURING THE
SYSTEM AND ALSO ON THE BACKSIDE. 12Z ECMWF HAS COME IN WITH A SLIGHT
SHIFT TO THE NORTH WITH THE LOW...SO FUTURE SHIFTS WILL HAVE TO
MONITOR IF THIS TREND CONTINUES.
FORECAST BECOMES MORE UNCERTAIN FOR MONDAY/TUESDAY OF NEXT
WEEK...WITH THE 00Z ECMWF HOLDING THE UPPER TROUGH OVER THE UPPER
GREAT LAKES REGION AND THE GFS AND IT/S ENSEMBLE PUSHING THE WAVE
OFF TO THE NEW ENGLAND STATES. 12Z ECMWF HAS TRENDED MORE
PROGRESSIVE...SO THERE COULD BE LIGHT LES OFF LAKE SUPERIOR MONDAY
AND TUESDAY AND SLIGHT CHANCE POPS REPRESENTS THAT WELL AT THIS
POINT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1236 AM EST WED DEC 12 2012
CMX...EXPECT LINGERING LES TO SHIFT TO THE N OF CMX AND DIMINISH
THRU THIS MRNG AS LARGER SCALE SUBSIDENCE DEVELOPS OVER THE AREA AND
THE FLOW BEGINS TO BACK MORE TO THE SW...WITH PREDOMINANT MVFR
CONDITIONS BY 09Z. AS THE WIND BACKS FURTHER TO THE S ON WED...VFR
WX WL BE THE RULE WITH ARRIVAL OF DRIER AIR.
IWD/SAW...PREDOMINANT MVFR CIGS AT TAF TIME WL GIVE WAY TO VFR WX BY
09Z UNDER LARGER SCALE SUBSIDENCE AND AS BACKING FLOW TO A MORE
DOWNSLOPE SW DIRECTION ADVECTS DRIER AIR INTO THE AREA. EXPECT VFR
CONDITIONS AND GUSTY S WINDS ON WED AS THE PRES GRADIENT TIGHTENS
OVER THE UPR LKS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 424 PM EST TUE DEC 11 2012
SOUTHWEST WINDS TO 25 KTS WILL SHIFT WESTERLY THIS EVENING AS A
TROUGH MOVES THROUGH THE AREA AND THEN DIMINISH BRIEFLY BLO 20 KNOTS
LATE TONIGHT INTO WED MORNING. EXPECT INCREASING SOUTH TO SOUTHWEST
WINDS LATE WEDNESDAY INTO WEDNESDAY NIGHT. MARGINAL GALES TO 35
KNOTS ARE POSSIBLE OVER EASTERN PORTIONS OF LAKE SUPERIOR SO WILL
KEEP GALE WATCH IN EFFECT. A WEAK TROUGH DROPS ACROSS THE LAKE BY
THURSDAY EVENING. WINDS WILL DIMINISH SIGNIFICANTLY THURSDAY NIGHT
INTO FRIDAY IN THE WAKE OF THIS TROUGH. A LOW PRESSURE SYSTEM
DEVELOPING IN THE PLAINS PUSHES INTO WESTERN GREAT LAKES LATE
SATURDAY INTO SUNDAY WHILE HIGH PRESSURE MOVES ACROSS NEW ENGLAND.
WINDS SHOULD INCREASE FROM THE EAST ON SATURDAY OVER LAKE SUPERIOR.
SINCE EXACT TRACK AND DEPTH OF SFC LOW REMAINS UNCERTAIN AT THIS
TIME...WILL KEEP WINDS SUB-GALE FOR NOW.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ003.
LAKE SUPERIOR...
GALE WATCH FROM THIS EVENING THROUGH LATE TONIGHT FOR LSZ265>267.
LAKE MICHIGAN...
GALE WATCH FROM THIS EVENING THROUGH THURSDAY MORNING FOR LMZ248-
250.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...KC
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DULUTH MN
1148 PM CST TUE DEC 11 2012
.AVIATION.../06Z TAF ISSUANCE/
LOW CLOUDS ACROSS NWRN WI AND THE MN ARROWHEAD WILL CONTINUE TO
MOVE OFF TO THE EAST EARLY THIS MORNING AS A RIDGE OF HIGH
PRESSURE BUILDS OVER THE UPPER MIDWEST. THIS RIDGE WILL QUICKLY
DEPART EWD AND GIVE WAY TO A SHORTWAVE TRACKING ALONG THE INTL
BORDER. A MID-LEVEL CLOUD DECK WILL PRECEDE THE SHORTWAVE...WITH
CIGS GRADUALLY LOWERING THIS MORNING. THE SHORTWAVE WILL ALSO
PRODUCE AREAS OF LIGHT TO MODERATE SNOW WITH MVFR CIGS AND
MVFR/IFR VSBYS MAINLY NORTH OF THE IRON RANGE ON WEDNESDAY.
FARTHER SOUTH...ANY SNOW SHOULD BE IN THE FORM OF FLURRIES DUE TO
A DRY LAYER IN THE LOWER ATMOSPHERE. HAVE MENTIONED A SCT-BKN015
DECK AT MOST OF THE TAF SITE AS THE NAM12 TIME/HEIGHT CROSS
SECTIONS SHOWS A THIN LAYER OF HIGH RH NEAR THE GROUND. THIS MIGHT
BE A PRODUCT OF COLD AIR NEAR THE SURFACE...BUT NOT CONFIDENT
ENOUGH TO LEAVE MENTION OF LOW CLOUD DECK OUT OF TAFS.
&&
.PREV DISCUSSION... /ISSUED 634 PM CST TUE DEC 11 2012/
AVIATION.../00Z TAF ISSUANCE/
AN AREA OF LOW CLOUDS WITH MVFR CLOUDS ASSOC WITH A DEPARTING
SHORTWAVE WILL GRADUALLY DIMINISH OR DISSIPATE OVERNIGHT TONIGHT.
LIGHT SNOW WITH LOCALIZED MVFR CIGS WILL LINGER ACROSS THE CWA THIS
EVENING AS WELL. ANOTHER SHORTWAVE FROM CANADA WILL DIG SEWD
ACROSS THE NORTHLAND LATE TONIGHT THROUGH WEDNESDAY. LIGHT TO
MODERATE SNOW WILL AFFECT AREAS ALONG THE CANADIAN BORDER...BUT
FROM THE IRON RANGE ON SOUTH...CONDITIONS SHOULD BE MAINLY DRY.
PREV DISCUSSION... /ISSUED 314 PM CST TUE DEC 11 2012/
SHORT TERM...THROUGH WEDNESDAY NIGHT.
LAKE EFFECT SNOW ALONG THE NORTH SHORE HAS DIMINISHED THIS
AFTERNOON AS WINDS HAVE TURNED MORE WESTERLY BEHIND THE DEPARTING
LOW. A LAKE BAND OF LIGHT SNOW SHOWERS ALSO EXTENDED FROM JUST OFF
SHORE OF DOUGLAS COUNTY...ALONG THE BAYFIELD PENINSULA TOWARD RED
CLIFF. THIS WILL LIKELY CONTINUE THROUGH MOST OF THE EVENING AS
THE LOW LEVEL FLOW REMAINS WEST-SOUTHWEST. FETCH WILL BE
LIMITED...AND THE NAM AND RUC BOTH SHOW LOWERING RH THROUGH THE
EVENING...SO WE THINK ACCUMULATIONS WILL BE LIMITED. PLENTY OF CLOUDS
REMAIN OVER THE REST OF THE NORTHLAND...WITH FLURRIES/LIGHT SNOW
STILL OCCURRING. A WEAK SHORTWAVE WAS MOVING THROUGH CENTRAL
MINNESOTA THIS AFTERNOON...WITH RADAR HIGHER RETURNS WELL SOUTH OF
THE CWA.
HIGH PRESSURE WILL MOVE QUICKLY THROUGH THE NORTHLAND
TONIGHT...WITH WAA INCREASING OVERNIGHT AHEAD OF AN AREA OF LOW
PRESSURE. WE HAVE A CHANCE FOR LIGHT SNOW LATER TONIGHT OVER
NORTHWEST AREAS...AND INCREASED POPS TO LIKELY BETWEEN 09-12Z OVER
KOOCHICHING COUNTY. THE WAA AND WEAK SHORT WAVE WILL CONTINUE TO
IMPACT FAR NORTHERN AREAS WEDNESDAY...AND WE HAVE INCREASED POPS
TO LIKELY AS ACCUMULATIONS UP TO TWO INCHES WILL BE POSSIBLE IN
SPOTS. THERE MAY ALSO BE A NARROW WINDOW FOR LAKE EFFECT SNOW
WEDNESDAY MORNING BETWEEN LITTLE MARAIS AND GRAND PORTAGE AGAIN.
FETCH BECOMES FAVORABLE WEDNESDAY MORNING...BUT WAA WILL CAUSE
850MB TEMPS TO RISE QUICKLY. WE`LL HAVE TO KEEP A CLOSE EYE ON
THAT AREA AS WE COULD GET A QUICK BURST OF SEVERAL INCHES OF SNOW
IF THE TEMPS ALOFT DON`T WARM AS FAST AS ANTICIPATED.
TEMPERATURES TONIGHT WILL BE A CHALLENGE...AS THEY WILL BE HIGHLY
DEPENDENT ON CLEARING. WE DID DROP THEM MOST AREAS...HAVE SOME
WELL BELOW ZERO OVER NORTHEAST MINNESOTA. EVENING SHIFT WILL HAVE
TO MONITOR CLOUD TRENDS CLOSELY...AS WE MAY NOT BE COLD ENOUGH IF
IT CLEARS LONGER THAN ANTICIPATED. HIGHS WEDNESDAY WILL BE WARMER
THAN TODAY...WITH SOME AREAS REACHING AROUND THIRTY OVER NORTHWEST
WISCONSIN.
CONFIDENCE WEDNESDAY NIGHT IS LOWER THAN AVERAGE REGARDING SNOW
POTENTIAL. NAM WAS SHOWING A WEAK CIRCULATION AT 850MB AND
FORECASTS SOME LIGHT SNOW OVER THE FAR NORTH. THE MODELS ARE NOT
IN VERY GOOD AGREEMENT DURING THIS PERIOD. WE KEPT A MENTION OF
LIGHT SNOW OVER THE NORTH...AND EXPANDED A BIT SOUTH OVER OUR
WESTERN COUNTIES. IF THE MODELS TREND TOWARD THE NAM...WE WILL
NEED HIGHER POPS FOR SOME LIGHT SNOW ACCUMULATIONS OVER THE WEST
AND NORTHERN CWA.
LONG TERM...THURSDAY - MONDAY.
THE NORTHLAND SHOULD FIND ITSELF THURSDAY MORNING WITH A STATIONARY
FRONT NEAR OR SOUTH OF THE FA. THERE MAY BE SOME LIGHT SNOW ACROSS
THE NORTHERN FA THURSDAY ASSOCIATED WITH PLENTIFUL LOW CLOUDS NORTH
OF THE FRONT. HIGH PRESSURE IN CANADA WILL BEGIN TO EXERT GREATER
INFLUENCE ON THE NORTHLAND THURSDAY NIGHT...PROVIDING DRY WEATHER
THROUGH FRIDAY NIGHT. THE MODELS ARE LATCHING ONTO A STRONG LOW
PRESSURE SYSTEM MOVING FROM THE CENTRAL PLAINS TO UPPER MIDWEST ON
SATURDAY. THIS SYSTEM COULD BRING SIGNIFICANT SNOWFALL TO PARTS OF
THE FA...ESPECIALLY THE SOUTHEASTERN FA WHICH WILL BE IN BETTER
PROXIMITY TO THE SYSTEM. TEMPERATURES THROUGH THE PERIOD SHOULD BE
NEAR OR SLIGHTLY ABOVE NORMAL.
AVIATION...18Z TAFS
IFR/MVFR CONDITIONS ACROSS NE MINNESOTA AND NW MINNESOTA ARE
EXPECTED TO CONTINUE THROUGH THIS AFTERNOON AND INTO EARLY THIS
EVENING. CIGS WILL LIKELY RANGE FROM 1500 TO 3000 FT...AND THE
-SN WILL OCCASIONALLY REDUCE VIS TO IFR. THE SNOW SHOULD BEGIN TO
SUBSIDE LATER THIS AFTERNOON. THE CLOUDS WILL BEGIN TO CLEAR AT
KINL BY MID AFTERNOON...AND THEN AT OTHER TERMINALS LATE THIS
AFTERNOON AND EARLY THIS EVENING. EXPECT THE 5 TO 10 KNOT W TO SW
WINDS TO BECOME S TO SE TONIGHT. KINL COULD SEE MVFR CIGS
REDEVELOP LATE TONIGHT AND TOMORROW MORNING...BUT VFR CONDITIONS
ARE LIKELY TO RETURN TO KDLH/KHIB/KBRD/KHYR TONIGHT.
&&
.POINT TEMPS/POPS...
DLH 3 28 20 29 / 10 10 10 20
INL -9 23 8 19 / 60 60 30 20
BRD -5 29 17 28 / 10 10 20 10
HYR 2 32 22 33 / 20 10 10 0
ASX 5 33 25 35 / 20 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...BERDES
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
311 AM CST WED DEC 12 2012
.SHORT TERM (TODAY-FRIDAY NIGHT)...MAIN CONCERNS WILL BE SNOW
AMOUNTS THROUGH THIS MORNING...AND THEN AGAIN TONIGHT INTO
THURSDAY MORNING. 00Z MODELS INITIALIZED WITH MINIMAL ERRORS...AND
IN DECENT AGREEMENT. WILL USE A BLEND FOR ANY DETAIL DIFFERENCES.
CURRENT LIGHT SNOW EVENT MAINLY DRIVEN BY 850MB WARM AIR
ADVECTION. MODELS INDICATE LIGHT SNOW ACROSS THE NORTHERN FA THIS
MORNING...WITH THE HIGHEST TOTALS (3-4 INCHES) JUST NORTH OF THE
INTERNATIONAL BORDER. 1-3 INCHES ACROSS THE NORTHERN FA STILL
LOOKS GOOD. WEAK SFC LOW TRACKS THROUGH THE MIDDLE OF THE FA
SETTING UP A DECENT TEMPERATURE GRADIENT FROM NORTH TO SOUTH
TODAY. LOWERED MAX TEMPS ACROSS THE NORTH A FEW DEGREES...AND
RAISED VALUES ACROSS THE SOUTH A FEW DEGREES. THE MAIN CHALLENGE
WILL BE IN BETWEEN WITH EXACTLY HOW FAR NORTH THE WARMER TEMPS
ACTUALLY OCCUR.
TONIGHT...THE POTENTIAL APPEARS TO BE INCREASING FOR SOME TYPE OF
BANDED SNOW EVENT. MODELS ALL INDICATE A BAND OF MID-LEVEL
FRONTOGENESIS COMBINED WITH SYNOPTIC LIFT. MODEL CROSS SECTIONS
INDICATE THE POTENTIAL FOR SYMMETRIC INSTABILITY...WHICH WOULD
INCREASE LIFT. PWATS WILL BE AROUND 0.40 INCHES. GIVEN THESE
FORCING MECHANISMS...MODELS LIKELY UNDER FORECASTING
QPF...ESPECIALLY THE LOWER RESOLUTION MODELS. THE 06Z NAM12 IS
INDICATING 0.30-0.40 INCHES WITHIN THIS BAND (LEADING TO 3-5
INCHES OF SNOWFALL WITH ISOLATED 6 INCH AMOUNTS)...WHICH SEEMS
CLOSEST TO WHAT SHOULD ACTUALLY OCCUR. THIS BAND WOULD BE VERY
NARROW...MAKING EXACT PLACEMENT A PROBLEM. NAM INDICATES THIS BAND
WILL OCCUR ALONG A LINE FROM DVL-GFK-BJI...WHILE THE
GFS/ECMWF/GEM INDICATE THIS BAND WILL OCCUR JUST NORTH OF A
VALLEY CITY TO FARGO TO PARK RAPIDS LINE. GIVEN THE HIGH
UNCERTAINTY IN PLACEMENT AND QPF AMTS...HOW TO FORECAST THIS EVENT
IS TRICKY. THE BEST COURSE OF ACTION IS LIKELY TO PLACE HIGHER
CHANCE POPS WITHIN THE MODEL CONSENSUS LOCATION (WITH LOWER POPS
NORTH AND SOUTH) AND NOT GO CRAZY WITH SNOWFALL AMOUNTS.
HOWEVER...WILL MENTION THE POSSIBILITY FOR HIGHER TOTALS IN THE
HWO AND ALLOW ANOTHER MODEL RUN OR TWO FOR HIGHER CONFIDENCE.
THURSDAY-FRIDAY NIGHT...HIGH PRESSURE MOVES INTO THE REGION ON
THURSDAY...AND LARGE SYSTEM BEGINS TO EJECT INTO THE CENTRAL
PLAINS FRIDAY NIGHT. MOSTLY DRY THIS PERIOD WITH TEMPERATURES
INCREASING A BIT EACH DAY/NIGHT.
.LONG TERM (SATURDAY-TUESDAY)...AN UPPER LEVEL SHORTWAVE TROUGH
WILL LIFT FROM THE CENTRAL PLAINS INTO THE SOUTHERN GREAT LAKES BY
LATE SATURDAY. THE ECMWF HAS BEEN THE MOST CONSISTENT WITH A MORE
NORTHERN TRACK OF THE SFC LOW UP INTO NORTHERN IOWA/SOUTHERN
WISCONSIN BY LATE SATURDAY...WITH THE GEM GENERALLY SHOWING A MORE
NORTHERN SOLUTION AS WELL. THE GFS HAS BEEN FARTHER SOUTH WITH
CONSIDERABLY MORE RUN-TO-RUN VARIABILITY. WITHOUT A LOT OF COLD
AIR AVAILABLE TO THE NORTH OF THE SYSTEM...A TRACK FARTHER NORTH
WOULD MAKE SENSE. A MORE NORTHERN SOLUTION WOULD INCREASE THE
CHANCE FOR ACCUMULATING SNOW ACROSS THE FAR SOUTHEAST PART OF THE
AREA...BUT CONFIDENCE IS STILL FAIRLY LOW REGARDING THE EXACT
TRACK OF THE STORM...AND HOW FAR NORTH AND WEST THE PRECIP WILL
GET. AS A RESULT...KEPT LOW POPS ACROSS THE SOUTHEAST HALF OF THE
AREA SAT/SAT NIGHT. HOWEVER...THIS SYSTEM WILL HAVE TO BE
MONITORED.
OTHERWISE...THE REST OF THE PERIOD LOOKS TO BE PRETTY QUIET. THE
SOUTHERN STREAM OF THE JET IS EXPECTED TO BE DOMINANT AND SUPPRESSED
ACROSS THE SOUTHERN CONUS...AS UPPER RIDGING DEVELOPS ACROSS EASTERN
CANADA. AS A RESULT...NO MAJOR WEATHER SYSTEMS ARE EXPECTED ACROSS
THE NORTHERN PLAINS. TEMPERATURES WILL REMAIN SEASONABLE...WITH NO
SIGNIFICANT INTRUSIONS OF COLD AIR.
&&
.AVIATION...AREA OF LIGHT SNOW ACROSS NORTHEAST NORTH DAKOTA INTO
NORTHWEST MINNESOTA WILL EXIT DURING THE MORNING HOURS. THERE IS A
BAND OF MVFR CIGS ACROSS EASTERN NORTH DAKOTA THAT WILL MOVE EAST
AND NORTH THROUGH THE DAY...AND THEN BACK SOUTH TONIGHT. WILL USE
THE LATEST RAP GUIDANCE FOR TIMING IN EACH TAF.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
TG/MAKOWSKI
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
404 AM EST WED DEC 12 2012
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE WILL SETTLE OVER THE REGION FOR THE
REST OF THE WEEK. EXPECT DRY WEATHER WITH SEASONABLY COOL
TEMPERATURES AT FIRST AND A GRADUAL WARMING LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS BEING STUBBORN IN THE UPSLOPE FLOW UNDER THE STILL-PRESENT
AND STILL-ALOFT INVERSION. NAM AND RUC BOTH DELAY THE CLEARING FOR
ANOTHER 6-9 HRS...BUT MAKE IT MUCH MORE-SUNNY BY NOON OVER MOST OF
THE AREA THANKS TO THE MEETING OF THE DRY AIR ALOFT AND A WELL-
MIXED BOUNDARY LAYER. WILL USE AN EQUAL MIX OF NAM AND GFS MOS
GUIDANCE FOR MAXES WHICH RETAINS CONTINUITY AND USUALLY PERFORMS
VERY WELL ON HIGH PRESSURE DAYS. THIS RESULTS IN LITTLE TO NO
CHANGE TO THE FORECAST TEMPS TODAY. VALUES WILL BE VERY CLOSE TO
NORMALS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ALMOST NOTHING TO PICK OUT OF THE FORECAST AS A CHALLENGE/PROBLEM-
OF-THE-DAY FOR THE NEXT COUPLE OF DAYS WHILE THE 1030MB HIGH
PRESSURE RIDGE SITS RIGHT OVERHEAD. SOME EARLY MORNING RIVER
VALLEY FOG MAY FORM EACH MORNING IN THE NRN VALLEYS...BUT THE
AIRMASS IS VERY DRY. THUS...WILL NOT MENTION IT AT THIS POINT WITH
NO CERTAINTY IN THAT MATTER. OTHERWISE...HIGH/GREAT CERTAINTY LIES
IN THE SKY/WX/WIND/PRECIP FORECASTS FOR THE PERIOD. BIGGEST NEWS
WILL BE THE WARM UP FROM WED INTO THURS...AND THEN FOR FRIDAY.
HIGHS WILL RISE 3-5F EACH DAY IN MOST LOCATIONS AS THE BIG HIGH
SINKS TO THE SOUTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LOW PRESSURE WILL EJECT NEWD FROM THE S/CNTRL PLAINS AND REACH
THE UPPER OH VALLEY/GREAT LAKES REGION BY 12Z SUNDAY. THE LATEST
MODEL AND ENSEMBLE GUIDANCE SHOWS SOME WEAK SECONDARY DEVELOPMENT
INTO MONDAY...AS ENERGY IS TRANSFERRED TO THE NRN MID-ATLANTIC/SRN
NEW ENGLAND COAST. THIS MILLER-B TYPE SCENARIO IS USUALLY NOT
FAVORABLE FOR SNOW...AS THE INITIAL WRN LOW TRACK ALLOWS WARM AIR
TO STREAM NEWD INTO THE AREA. 12Z ENSEMBLE 850MB TEMPS ARE ABOVE
0C OVER PA WITH RAIN/SNOW LINE TO THE NORTH. THE MAJORITY OF GEFS
PLUMES ALSO INDICATE A WARM SOLUTION. THEREFORE WILL MENTION RAIN
AS PRIMARY PTYPE FOR THE BULK OF THE UPCOMING WEEKEND PCPN
EVENT...WITH PERHAPS SOME SPOTTY -FZRA AT THE ONSET IF ENOUGH SUB-
FZG AIR CAN REMAIN ENTRENCHED EAST OF THE ALLEGHENIES. ANY CHANGE
IN THE LOW TRACK COULD ALTER THERMAL PROFILES. A WEAK AREA OF HIGH
PRES SHOULD LIMIT PCPN CHANCES EARLY NEXT WEEK WITH HIGHEST POPS
NEAR THE LWR GRT LKS DUE TO BRIEF NW FLOW TRAJECTORY. MEDIUM RANGE
DATA WANTS TO SPIN-UP ANOTHER LOW ALONG THE EAST COAST BY NEXT
WEDNESDAY...BUT THERE IS TOO MUCH SPREAD AND UNCERTAINTY THIS FAR
OUT TO GET EXCITED ABOUT A STORM.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
AREAS OF MVFR STRATOCU LINGER ACROSS HIGHER TERRAIN OF THE
WEST...BUT EVERYWHERE ELSE IS VFR. AS RIDGE BUILDS OVER THE
REGION...EXPECT THESE CIGS TO GRADUALLY DISSIPATE AS OVERNIGHT
PROGRESSES.
HIGH PRESSURE TAKES OVER ON WED AS RIDGE SETTLES IN FOR THE NEXT
SEVERAL DAYS BRINGING PREVAILING VFR CONDITIONS.
OUTLOOK...
WED-FRI...NO SIG WX EXPECTED.
SAT-SUN...RAIN/FZRA POSSIBLE LATE SAT INTO EARLY SUNDAY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...CERU/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
729 AM EST WED DEC 12 2012
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE WILL SETTLE OVER THE REGION FOR THE
REST OF THE WEEK. EXPECT DRY WEATHER WITH SEASONABLY COOL
TEMPERATURES AT FIRST AND A GRADUAL WARMING LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS BEING STUBBORN IN THE UPSLOPE FLOW UNDER THE STILL-PRESENT
AND STILL-ALOFT INVERSION. NAM AND RUC BOTH CREATE CLEARING BUT
NOT FOR ANOTHER 6-9 HRS. SO IT SHOULD BE MORE-SUNNY BY NOON OVER
MOST OF THE AREA THANKS TO THE MEETING OF THE DRY AIR ALOFT AND A
WELL-MIXED BOUNDARY LAYER. WILL USE AN EQUAL MIX OF NAM AND GFS
MOS GUIDANCE FOR MAXES WHICH RETAINS CONTINUITY AND USUALLY
PERFORMS VERY WELL ON HIGH PRESSURE DAYS. THIS RESULTS IN LITTLE
TO NO CHANGE TO THE FORECAST TEMPS TODAY. VALUES WILL BE VERY
CLOSE TO NORMALS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ALMOST NOTHING TO PICK OUT OF THE FORECAST AS A CHALLENGE/PROBLEM-
OF-THE-DAY FOR THE NEXT COUPLE OF DAYS WHILE THE 1030MB HIGH
PRESSURE RIDGE SITS RIGHT OVERHEAD. SOME EARLY MORNING RIVER
VALLEY FOG MAY FORM EACH MORNING IN THE NRN VALLEYS...BUT THE
AIRMASS IS VERY DRY. THUS...WILL NOT MENTION IT AT THIS POINT WITH
NO CERTAINTY IN THAT MATTER. OTHERWISE...HIGH/GREAT CERTAINTY LIES
IN THE SKY/WX/WIND/PRECIP FORECASTS FOR THE PERIOD. BIGGEST NEWS
WILL BE THE WARM UP FROM WED INTO THURS...AND THEN FOR FRIDAY.
HIGHS WILL RISE 3-5F EACH DAY IN MOST LOCATIONS AS THE BIG HIGH
SINKS TO THE SOUTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LOW PRESSURE WILL EJECT NEWD FROM THE S/CNTRL PLAINS AND REACH
THE UPPER OH VALLEY/GREAT LAKES REGION BY 12Z SUNDAY. THE LATEST
MODEL AND ENSEMBLE GUIDANCE SHOWS SOME WEAK SECONDARY DEVELOPMENT
INTO MONDAY...AS ENERGY IS TRANSFERRED TO THE NRN MID-ATLANTIC/SRN
NEW ENGLAND COAST. THIS MILLER-B TYPE SCENARIO IS USUALLY NOT
FAVORABLE FOR SNOW...AS THE INITIAL WRN LOW TRACK ALLOWS WARM AIR
TO STREAM NEWD INTO THE AREA. 12Z ENSEMBLE 850MB TEMPS ARE ABOVE
0C OVER PA WITH RAIN/SNOW LINE TO THE NORTH. THE MAJORITY OF GEFS
PLUMES ALSO INDICATE A WARM SOLUTION. THEREFORE WILL MENTION RAIN
AS PRIMARY PTYPE FOR THE BULK OF THE UPCOMING WEEKEND PCPN
EVENT...WITH PERHAPS SOME SPOTTY -FZRA AT THE ONSET IF ENOUGH SUB-
FZG AIR CAN REMAIN ENTRENCHED EAST OF THE ALLEGHENIES. ANY CHANGE
IN THE LOW TRACK COULD ALTER THERMAL PROFILES. A WEAK AREA OF HIGH
PRES SHOULD LIMIT PCPN CHANCES EARLY NEXT WEEK WITH HIGHEST POPS
NEAR THE LWR GRT LKS DUE TO BRIEF NW FLOW TRAJECTORY. MEDIUM RANGE
DATA WANTS TO SPIN-UP ANOTHER LOW ALONG THE EAST COAST BY NEXT
WEDNESDAY...BUT THERE IS TOO MUCH SPREAD AND UNCERTAINTY THIS FAR
OUT TO GET EXCITED ABOUT A STORM.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
AREAS OF MVFR STRATOCU CONTINUE TO LINGER ACROSS HIGHER TERRAIN OF
THE WEST...AND WILL PERSIST FOR AT LEAST A COUPLE MORE HOURS
BEFORE LIFTING TO VFR. EVERYWHERE ELSE IS ALREADY VFR. AS RIDGE
CONTINUES TO BUILDS OVER THE REGION...SHOULD SEE INCREASING
SUNSHINE ALONG WITH LIGHT WINDS TODAY.
HIGH PRESSURE RIDGE SETTLES IN FOR THE NEXT SEVERAL DAYS...
BRINGING EXTENDED PERIOD OF PREVAILING VFR CONDITIONS.
OUTLOOK...
WED-SAT...NO SIG WX EXPECTED.
SAT NIGHT-SUN...FZRA POSS LATE SAT INTO EARLY SUNDAY...OTHERWISE
RAIN LIKELY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
623 AM EST WED DEC 12 2012
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE WILL SETTLE OVER THE REGION FOR THE
REST OF THE WEEK. EXPECT DRY WEATHER WITH SEASONABLY COOL
TEMPERATURES AT FIRST AND A GRADUAL WARMING LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS BEING STUBBORN IN THE UPSLOPE FLOW UNDER THE STILL-PRESENT
AND STILL-ALOFT INVERSION. NAM AND RUC BOTH CREATE CLEARING BUT
NOT FOR ANOTHER 6-9 HRS. SO IT SHOULD BE MORE-SUNNY BY NOON OVER
MOST OF THE AREA THANKS TO THE MEETING OF THE DRY AIR ALOFT AND A
WELL-MIXED BOUNDARY LAYER. WILL USE AN EQUAL MIX OF NAM AND GFS
MOS GUIDANCE FOR MAXES WHICH RETAINS CONTINUITY AND USUALLY
PERFORMS VERY WELL ON HIGH PRESSURE DAYS. THIS RESULTS IN LITTLE
TO NO CHANGE TO THE FORECAST TEMPS TODAY. VALUES WILL BE VERY
CLOSE TO NORMALS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ALMOST NOTHING TO PICK OUT OF THE FORECAST AS A CHALLENGE/PROBLEM-
OF-THE-DAY FOR THE NEXT COUPLE OF DAYS WHILE THE 1030MB HIGH
PRESSURE RIDGE SITS RIGHT OVERHEAD. SOME EARLY MORNING RIVER
VALLEY FOG MAY FORM EACH MORNING IN THE NRN VALLEYS...BUT THE
AIRMASS IS VERY DRY. THUS...WILL NOT MENTION IT AT THIS POINT WITH
NO CERTAINTY IN THAT MATTER. OTHERWISE...HIGH/GREAT CERTAINTY LIES
IN THE SKY/WX/WIND/PRECIP FORECASTS FOR THE PERIOD. BIGGEST NEWS
WILL BE THE WARM UP FROM WED INTO THURS...AND THEN FOR FRIDAY.
HIGHS WILL RISE 3-5F EACH DAY IN MOST LOCATIONS AS THE BIG HIGH
SINKS TO THE SOUTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LOW PRESSURE WILL EJECT NEWD FROM THE S/CNTRL PLAINS AND REACH
THE UPPER OH VALLEY/GREAT LAKES REGION BY 12Z SUNDAY. THE LATEST
MODEL AND ENSEMBLE GUIDANCE SHOWS SOME WEAK SECONDARY DEVELOPMENT
INTO MONDAY...AS ENERGY IS TRANSFERRED TO THE NRN MID-ATLANTIC/SRN
NEW ENGLAND COAST. THIS MILLER-B TYPE SCENARIO IS USUALLY NOT
FAVORABLE FOR SNOW...AS THE INITIAL WRN LOW TRACK ALLOWS WARM AIR
TO STREAM NEWD INTO THE AREA. 12Z ENSEMBLE 850MB TEMPS ARE ABOVE
0C OVER PA WITH RAIN/SNOW LINE TO THE NORTH. THE MAJORITY OF GEFS
PLUMES ALSO INDICATE A WARM SOLUTION. THEREFORE WILL MENTION RAIN
AS PRIMARY PTYPE FOR THE BULK OF THE UPCOMING WEEKEND PCPN
EVENT...WITH PERHAPS SOME SPOTTY -FZRA AT THE ONSET IF ENOUGH SUB-
FZG AIR CAN REMAIN ENTRENCHED EAST OF THE ALLEGHENIES. ANY CHANGE
IN THE LOW TRACK COULD ALTER THERMAL PROFILES. A WEAK AREA OF HIGH
PRES SHOULD LIMIT PCPN CHANCES EARLY NEXT WEEK WITH HIGHEST POPS
NEAR THE LWR GRT LKS DUE TO BRIEF NW FLOW TRAJECTORY. MEDIUM RANGE
DATA WANTS TO SPIN-UP ANOTHER LOW ALONG THE EAST COAST BY NEXT
WEDNESDAY...BUT THERE IS TOO MUCH SPREAD AND UNCERTAINTY THIS FAR
OUT TO GET EXCITED ABOUT A STORM.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AREAS OF MVFR STRATOCU LINGER ACROSS HIGHER TERRAIN OF THE
WEST...BUT EVERYWHERE ELSE IS VFR. AS RIDGE BUILDS OVER THE
REGION...EXPECT THESE CIGS TO GRADUALLY DISSIPATE AS OVERNIGHT
PROGRESSES.
HIGH PRESSURE TAKES OVER ON WED AS RIDGE SETTLES IN FOR THE NEXT
SEVERAL DAYS BRINGING PREVAILING VFR CONDITIONS.
OUTLOOK...
WED-FRI...NO SIG WX EXPECTED.
SAT-SUN...RAIN/FZRA POSSIBLE LATE SAT INTO EARLY SUNDAY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...STEINBUGL
AVIATION...CERU/RXR
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
332 PM MST WED DEC 12 2012
.SHORT TERM...WEST SOUTHWEST FLOW ALOFT CURRENTLY ACROSS REGION
WITH UPPER LEVEL RIDGE OVER COLORADO. MOUNTAIN WAVE PRODUCING
GUSTY WINDS ACROSS MOUNTAINS AND ALONG FOOTHILLS...WITH GUSTS
AROUND 50 MPH OVER THE HIGHER RIDGES. ACROSS PLAINS...WAVE CLOUD
HAD DISSIPATED WHICH ALLOWED FOR DECENT MIXING. THIS ALLOWED
SOUTHWESTERLIES TO MIX TO THE SURFACE WITH SOME GUSTS TO 20 KTS.
LATEST RUC CROSS SECTION SHOWING CROSS MOUNTAIN FLOW OF 40 KTS AT
MOUNTAIN TOP INCREASING TO 45 KTS BY 00Z. SHOULD SEE GUSTY WINDS
CONTINUE ACROSS MOUNTAINS AND FOOTHILLS INTO THE EVENING WITH SOME
GUSTS TO 60 MPH POSSIBLE ACROSS THE HIGHER RIDGES. WESTERLIES
SHOULD ALSO MOVE ONTO THE ADJACENT PLAINS. UPPER LEVEL RIDGE TO
MOVE ONTO THE CENTRAL PLAINS BY MIDNIGHT WITH THE FLOW ALOFT
BECOMING MORE SOUTHWEST. MODELS SHOW THE WINDS ALOFT WEAKENING
THOUGH CROSS MOUNTAIN FLOW REMAINS AT 40 KTS AT MOUNTAIN TOP.
COULD STILL SEE SOME GUSTS ACROSS THE HIGHER RIDGES. WRF SYNTHETIC
SATELLITE IMAGERY SHOW SOME DEVELOPMENT OF A WAVE CLOUD ACROSS THE
SOUTHERN FOOTHILLS DURING THE EVENING SPREADING NORTHEAST ACROSS
THE PLAINS OVERNIGHT. ENOUGH TO MAINTAIN PARTLY CLOUDY CONDITIONS.
ON THURSDAY...SOUTHWEST FLOW ALOFT TO PREVAIL AS UPPER TROUGH
MOVES ONSHORE OVER THE WEST COAST. 600 MB WINDS 30-35 KTS WITH
MOUNTAIN TOP WINDS 20-25 KTS. NOT MUCH OF A MOUNTAIN WAVE EXPECTED
BUT APPEARS THERE WILL BE ENOUGH MIXING BY THE AFTERNOON FOR GUSTY
SOUTHWEST WINDS ACROSS THE MOUNTAINS AND FOOTHILLS. SHOULD ALSO
SEE SOUTHWESTERLIES ACROSS THE PLAINS DURING THE AFTERNOON. SHOULD
AGAIN SEE TEMPERATURES REACH THE 50S ACROSS THE PLAINS...PERHAPS
NOT AS WARM AS TODAY`S READINGS.
.LONG TERM...AN UPPER LEVEL LOW OVER SOUTHERN CALIFORNIA THURSDAY
EVENING WILL OPEN UP AND MOVE NORTHEAST OVER THE STATE BY FRIDAY
AFTERNOON. AREAS OF PRECIPITATION WILL BEGIN TO INCREASE FRIDAY
MORNING WITH SNOW IN THE MOUNTAINS AND A MIX OF RAIN AND SNOW OVER
THE PLAINS. THE 700 MB FLOW IS NOT PARTICULARLY FAVORED FOR
SIGNIFICANT ACCUMULATIONS WITH HELP FROM OROGRAPHICS...HOWEVER
GOOD QG VERTICAL VELOCITIES WILL LIKELY HAVE SOME CONVECTIVE
CHARACTERISTIC TO ADD TO ISOLATED AREAS. THE 700 MB FLOW WILL ALSO
TEND TO KEEP MOST OF THE WESTERN PLAINS...THE URBAN CORRIDOR
MOSTLY DRY WILL ALLOWING SOME SHOWERS TO OCCUR FURTHER EAST.
COOLER AIR MOVING IN WITH THE SYSTEM ALONG WITH CLOUD COVER WILL
PRODUCE MAX TEMPERATURES ABOUT 5-10 DEGREES COOLER THAN THURSDAY.
FRIDAY NIGHT INTO SATURDAY...THE SNOW WILL LIKELY CONTINUE IN THE
MOUNTAINS...ALBEIT LIGHT...WITH CLEARING CONDITIONS OVER THE
PLAINS. TOTAL SNOW ACCUMULATIONS FROM FRIDAY MORNING INTO SATURDAY
MORNING FOR THE MOUNTAINS COULD BE IN THE 3-8 INCHES...SO NO NEED
FOR ANY HIGHLIGHT RIGHT NOW. WILL CONTINUE TO MONITOR THE TRACK OF
THIS STORM.
SATURDAY NIGHT THROUGH SUNDAY WILL FEATURE TWO MORE SHORTWAVE
SYSTEMS TO KEEP A GOOD CHANCE OF SNOW FOR THE MOUNTAINS...BUT
LIKELY KEEPING THE PLAINS DRY.
STARTING SUNDAY...MODEL SOLUTIONS START TO SPREAD QUITE FAR APART
FROM EACH OTHER EVEN THOUGH THEY ARE MORE CONSISTENT IN
THEMSELVES. WILL HAVE A SLIGHT CHANCE FOR SNOW CONTINUE IN THE
MOUNTAINS THROUGH MONDAY WITH SLIGHT DRYING AFTERWARD. CONFIDENCE
IS QUITE LOW FOR THIS PERIOD HOWEVER.
&&
.AVIATION...SOUTHWESTERLIES HAVE MIXED TO THE SURFACE ACROSS THE
DENVER AIRPORTS...THOUGH THE WESTERLIES HAVEN`T MOVED INTO BJC.
LATEST RAP AND RUC STILL INDICATING A WESTERLY PUSH ACROSS AREA
00Z-02Z. WILL CONTINUE TO SHOW SOME SORT OF A WESTERLY COMPONENT
THROUGH 02Z BEFORE SOUTHWEST DRAINAGE PATTERN DEVELOPS. GUSTY
DOWNSLOPE WINDS SHOULD PREVAIL AT BJC OVERNIGHT. WAVE CLOUD COULD
REDEVELOP SOUTH AND EAST OF THE AREA OVERNIGHT...THOUGH CEILINGS
WILL REMAIN ABOVE 14000 FEET AGL. ON THURSDAY...SOUTHERLY
WINDS TO PREVAIL WITH MORE OF A WEST SOUTHWEST COMPONENT AT BJC.
WINDS COULD BECOME MORE SOUTHEAST AT DEN AND APA.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....KRIEDERMAN
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
939 AM MST WED DEC 12 2012
.UPDATE...
&&
.SHORT TERM...MODERATE WEST SOUTHWEST FLOW ALOFT CURRENTLY ACROSS
REGION WITH INVERSION AT MOUNTAIN TOP. MODEL CROSS SECTIONS SHOW WEAK
MOUNTAIN WAVE TO PERSIST THROUGH THE DAY BEFORE WEAKENING DURING
THE EVENING. RUC SHOWS CROSS MOUNTAIN FLOW OF 40-45 KTS AT
MOUNTAIN TOP THROUGH 00Z. THIS COMBINED WITH LEE TROUGH ALONG
FOOTHILLS WILL KEEP GUSTY WINDS GOING OVER THE MOUNTAINS AND
ALONG AND NEAR FOOTHILLS FOR MUCH OF THE DAY WITH SOME GUSTS
AROUND 50-55 MPH POSSIBLE...MAINLY HIGHER RIDGES. LATEST RUC AND
HRRR SHOW WESTERLY WINDS PUSHING ACROSS THE URBAN CORRIDOR AFTER
21Z. FAIRLY EXTENSIVE WAVE CLOUD CURRENTLY ALONG THE FRONT
RANGE...SHOWING SIGNS OF MOVING EAST. LATEST WRF SYNTHETIC
SATELLITE IMAGERY SHOWS THIS TREND WITH DECREASING CLOUDS ALONG
URBAN CORRIDOR. THE CLEARING SKIES AND DOWNSLOPE WINDS SHOULD
ALLOW TEMPERATURES ACROSS PLAINS TO WARM INTO THE 50S...WITH MID
TO UPPER 40S IN THE LOW LYING AREAS ALONG THE SOUTH PLATTE RIVER.
OVERALL...CURRENT FORECASTS SEEM IN ORDER...ONLY MINOR CHANGES AT
THIS TIME.
.AVIATION...IN GENERAL...CURRENT TAF TRENDS LOOK REASONABLE. MAY
NEED MORE OF A WESTERLY COMPONENT AT DIA AROUND 22Z AS LATEST RAP
AND HRRR SHOW A WESTERLY PUSH ACROSS THE DENVER AREA. APA MAY
REMAIN MORE SOUTHWEST. SHOULD SEE MORE OF A WESTERLY COMPONENT AT
BJC BY THE AFTERNOON AS DOWNSLOPE WINDS PUSH OFF THE FOOTHILLS.
&&
.PREV DISCUSSION... /ISSUED 223 AM MST WED DEC 12 2012/
SHORT TERM...A MODERATE WEST TO SOUTHWESTERLY FLOW ALOFT WILL BE
OVER THE CWFA UNDER A RIDGE OF HIGH PRESSURE ALOFT. A LEE TROUGH
ALONG THE FRONT RANGE COUPLED WITH A WEAK MOUNTAIN WAVE DEPICTED
IN THE SPATIAL CROSS-SECTIONS WILL ALLOW FOR PERSISTENT DOWNSLOPE
WINDS ALONG THE FRONT RANGE. STRONGEST WINDS WILL BE CONFINED TO
THE MOUNTAINS EAST OF THE CONTINENTAL DIVIDE AND HIGHER FOOTHILLS.
STRONGER GUSTS IN THE 45 TO 55 MPH RANGE SO NO HIGHLIGHTS NEEDED.
TEMPERATURES THIS AFTERNOON WILL WARM 10-15 DEGREES OVER MONDAY SO
WELL ABOVE SEASONAL NORMALS. SYNTHETIC SATELLITE DEPICTS ENOUGH
UPPER LEVEL MOISTURE TO CONTINUE WITH PARTLY CLOUDY FOR BOTH
PERIODS.
LONG TERM...MODELS HAVE SOUTHWESTERLY FLOW ALOFT FOR THE FORECAST
AREA THURSDAY THROUGH MIDDAY FRIDAY. AN UPPER TROUGH MOVES INTO
COLORADO BY FRIDAY AFTERNOON AND ACROSS THE FORECAST AREA BY LATE
FRIDAY NIGHT. THE GFS IS A HALF A PERIOD SLOWER WITH THIS FEATURE
COMPARED TO THE NAM. THERE IS WEAK UPWARD Q-G VERTICAL VELOCITY
PROGGED FOR THE CWA THURSDAY AND THURSDAY NIGHT. IT GETS STRONGER
ON FRIDAY. DOWNWARD MOTION IS PROGGED MUCH OF FRIDAY NIGHT. THE
BOUNDARY LAYER FLOW IS MAINLY DOWNSLOPING SOUTHWESTERLY THURSDAY
AND THURSDAY NIGHT. BY FRIDAY...THE LOW LEVEL FLOW IS EASTERLY
..THEN NORTHEASTERLY FRIDAY AFTERNOON INTO THE EVENING. LATER
FRIDAY NIGHT THE LOW LEVEL WINDS ARE NORTH-NORTHWESTERLY. FOR
MOISTURE...THURSDAY IS PRETTY DRY...SO IS MUCH OF THURSDAY NIGHT.
MOISTURE INCREASES BY EARLY FRIDAY MORNING. MOISTURE GETS PRETTY
DEEP FRIDAY...THE BEST OVER THE MOUNTAINS. ALTHOUGH THE NAM SHOWS
PRETTY DEEP MOISTURE OVER THE PLAINS...THE GFS AND ECMWF LESS.
MOISTURE STAYS PRETTY DEEP OVER THE MOUNTAINS FRIDAY EVENING...
THEN DECREASES. THERE IS NO MEASURABLE PRECIPITATION PROGGED ON
THE QPF FIELDS THURSDAY OR THURSDAY NIGHT. ALL THE MODELS HAVE
MEASURABLE PRECIPITATION FRIDAY AND FRIDAY EVENING...BUT AMOUNTS
ARE QUITE LIGHT...EVEN IN THE MOUNTAINS. THE NAM SHOWS THE WIDEST
COVERAGE OVER THE PLAINS...BUT AGAIN...AMOUNTS ARE MEAGER. FOR
POPS...DRY THURSDAY AND THURSDAY NIGHT FOR ALL AREAS. WILL GO WITH
30-50%S IN THE MOUNTAINS FRIDAY AND FRIDAY NIGHT. THE HELP FROM
OROGRAPHICS WILL BE POOR FRIDAY...BUT WILL GET A BIT BETTER FRIDAY
NIGHT. FOR THE PLAINS WILL GO WITH 10-20%S FRIDAY. FOR TEMPERATURES
..THURSDAY`S HIGHS LOOK SIMILAR TO WEDNESDAY`S. FRIDAY`S HIGHS
COOL OFF 2-5 C. FOR THE LATER DAYS...SATURDAY THROUGH TUESDAY...
MODELS HAVE A BRIEF WEAK UPPER RIDGE ON SATURDAY...THEN THE NEXT
TROUGH MOVES ACROSS LATE SATURDAY INTO SUNDAY MORNING. THEN
ANOTHER RIDGE SUNDAY...WITH ANOTHER WEAK TROUGH LATE SUNDAY NIGHT
INTO MONDAY MORNING. BY MID DAY MONDAY...CONTINUING THROUGH
TUESDAY...STRONG NORTHWESTERLY FLOW ALOFT IS PROGGED. WILL NEED
MOUNTAIN POPS SATURDAY THROUGH MONDAY...THEN DRY.
AVIATION...VFR CONDITIONS OVER THE NEXT 24 HRS. WINDS WILL
GENERALLY CONTINUE WITH SSWLY COMPONENT THROUGH THE PERIOD WITH A
PERSISTENT LEE TROUGH ALONG THE FRONT RANGE. WL CONTINUE TO
MENTION STRONGER WLY WINDS AT KBJC AS SOME DOWNSLOPE COMPONENT
PRESENT NEAR THE FOOTHILLS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
428 PM EST WED DEC 12 2012
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 427 PM EST WED DEC 12 2012
WATER VAPOR LOOP AND RUC ANALYSIS SHOWS AN AMPLIFIED TROF OFF THE
WEST COAST WITH BROAD TROUGH CENTERED OVER HUDSON BAY DOMINATING
MUCH OF CANADA. AT THE SFC...A STATIONARY FRONT IS DRAPED OVER NORTH
DAKOTA...NRN MN INTO WRN UPR MI. A SHORTWAVE MOVING ACROSS SOUTHERN
CANADA ALONG WITH ITS ASSOC MID-LVL Q-VECT CONV AND 800 MB FGEN HAS
SUPPORTED AN AREA OF LIGHT SNOW THIS AFTERNOON OVER SRN MANITOBA AND
WRN ONTARIO.
TONIGHT...BEST FGEN FORCING AND Q-VECT CONV WITH SRN CANADA
SHORTWAVE IS FCST BY MODELS TO STAY MAINLY NORTH OF THE CWA TONIGHT.
THUS...IT ALSO MAKES SENSE THAT MODEL QPF ALSO STAYS MAINLY NORTH OF
THE AREA. MAINTAINED SLGT CHC POPS OVER THE TIP OF THE KEWEENAW AND
NRN LAKE SUPERIOR AS WEAK FORCING COULD BRUSH THESE AREAS WITH LIGHT
SNOW AND POSSIBLY DZ/FZDZ AS THERE IS A DRY LAYER ALOFT WHICH COULD
TEMPORARILY DISRUPT ICE CRYSTAL NUCLEATION. TEMPS SHOULDN`T DROP
MUCH TONIGHT UNDER CLOUDS AND INCREASING BLYR WINDS. EXPECT LOWS
FROM THE MID 20S INTERIOR WEST TO THE UPPER 20S/LOWER 30S
ELSEWHERE.
THURSDAY...A 120 KT 3H JET STREAK STREAMING EAST FROM THE CENTRAL
ROCKIES COMBINED WITH INCREASING 850-800 MB FGEN IN LEFT EXIT REGION
OF JET HAVE MOST MODELS SUPPORTING A NARROW BAND OF PCPN OVER THE
KEWEENAW PENINSULA LATE THU MORNING INTO EARLY AFTERNOON. CONTINUED
DRY LAYER AT MID-LVLS MAY DISRUPT ICE CRYSTAL NUCLEATION TO SUPPORT
SOME DZ/FZDZ MIXING IN WITH LIGHT SNOW. EXPECT ONLY A DUSTING OF
SNOW (HALF INCH OF LESS) OVER THE KEWEENAW AND MAINTAINED JUST HIGH
CHC POPS FOR NOW.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 427 PM EST WED DEC 12 2012
A MORE ACTIVE PATTERN LOOKS TO BE DEVELOPING BY THE END OF THE
WEEK...WITH THE MAIN FOCUS ON A POTENTIAL FOR MODERATE SNOWFALL
ACROSS MUCH OF THE AREA ON SATURDAY...AND THEN LIGHTER SNOW LASTING
INTO NEXT WEEK.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE LARGE SCALE FLOW WILL BE
GENERALLY ZONAL OVER THE GREAT LAKES REGION SOUTH OF A BROAD
MID-LEVEL LOW ACROSS HUDSON BAY AND NORTHERN QUEBEC. MEANWHILE...A
WEAK SHORTWAVE TROUGH WILL BE MOVING ESE ACROSS SOUTHERN MANITOBA
INTO WESTERN ONTARIO...AND A DEEP TROUGH WILL BE MOVING ONSHORE IN
CENTRAL AND SOUTHERN CA. THE DEEP WESTERN TROUGH WILL BE THE FOCUS
FOR SATURDAY ONWARD. BEFORE THEN...THE SHORTWAVE TROUGH IN SOUTHERN
CANADA WILL TRACK ACROSS WESTERN ONTARIO THURSDAY NIGHT...AND INTO
EASTERN ONTARIO BY FRIDAY AFTERNOON. INFLUENCE OF THIS TROUGH IS A
BIT WEAK ACROSS UPPER MI...AND MID-RANGE MODELS HAVE SOME
DISAGREEMENT ON PRECIP CHANCES. MID/UPPER FORCING IS NOT IMPRESSIVE
BY ANY MEANS UNTIL THE RIGHT ENTRANCE OF A 120KT UPPER JET CROSSES
THE CWA FRIDAY MORNING. BY THIS TIME...THE MID-LEVEL TROUGH WILL
ALMOST BE THROUGH THE AREA...WITH MID-LEVEL SUBSIDENCE/DRYING TAKING
HOLD. HOWEVER...LOW-LEVEL MOISTURE LINGERS...ESPECIALLY ACROSS THE
NORTHERN HALF OF THE CWA. WIND IS RATHER LIGHT AND VARIABLE THURSDAY
NIGHT THROUGH FRIDAY MORNING...BUT FAVORABLE DIRECTION IS BETWEEN N
AND E. WILL KEEP GENERAL SLIGHT CHANCE OF FZDZ NORTH...AND HAVE
EXPANDED IT SLIGHTLY TO ACCOUNT FOR TERRAIN EFFECTS.
OVERALL...EXPECT THE BEST CHANCE OF FZDZ TO BE LATE THURSDAY NIGHT
BEFORE DIMINISHING FRIDAY MORNING AS WINDS VEER TO THE SE.
BY FRIDAY EVENING...LOW LEVEL MOISTURE ADVECTING NORTHWARD AHEAD OF
THE NEXT SYSTEM WILL BRING ANOTHER POTENTIAL FOR FREEZING
DRIZZLE...THIS TIME ACROSS THE SOUTH-CENTRAL. SOUTHEAST WINDS OFF OF
LAKE MICHIGAN WILL ASSIST WITH THE MOISTURE SUPPLY...BUT THE
MOISTURE WILL BE SHALLOW (2KFT) AS A RESULT OF DRYING/SUBSIDENCE
UNDER A DEPARTING RIDGE. HAVE MENTIONED A SLIGHT CHANCE OF FREEZING
DRIZZLE IN THE HIGHER TERRAIN ACROSS THE SOUTH-CENTRAL...MAINLY
FOCUSED IN DICKINSON AND SOUTHERN MARQUETTE COUNTIES. INCREASING
CLOUD COVER COMBINED WITH STRENGTHENING WINDS SHOULD RESULT IN A
STEADY TEMP RISE THROUGHOUT THE NIGHT...WITH LOCATIONS ALONG LAKE
MICHIGAN REACHING ABOVE FREEZING BY DAY BREAK.
SATURDAY...RATHER COMPLICATED FORECAST CONCERNING THE POTENTIAL FOR
A STRONG LOW PRESSURE SYSTEM MOVING INTO THE AREA SATURDAY.
CONFIDENCE IS RUNNING LOW WITH THIS SYSTEM ATTM FOR SEVERAL REASONS.
FIRST...THE MID-LEVEL TROUGH IS STILL BARRELING SOUTHWARD ALONG THE
CA COAST THIS AFTERNOON...SO WHERE IT MAKES AN EASTWARD TURN WILL
HAVE SOME IMPLICATION ON OVERALL PLACEMENT AS IT MOVES OUT OF THE
LEE OF THE ROCKIES. ALL LONG TERM MODELS ARE IN GENERAL AGREEMENT OF
THE INITIAL PROGRESSION TAKING THE TROUGH THROUGH NORTHERN AZ. THIS
IS THE POINT WHERE THE MODELS DIVERGE...WITH THE EMERGENCE OF THE
LEE LOW RANGING FROM NEAR DENVER TO THE OK PANHANDLE. DIFFERENCES
CONTINUE TO GROW FROM THERE ON.
THE SECOND ISSUE COMES FROM THE TIMING OF ANOTHER SHORTWAVE TROUGH
MOVING ACROSS SOUTHERN CANADA AS EACH MODEL IS HANDLING THE STRENGTH
AND TIMING DIFFERENTLY. THE NAM IS THE STRONGEST/QUICKEST WITH THE
NORTHERN TROUGH...RESULTING IN AN INTERACTION WITH THE SOUTHERN
TROUGH MUCH FARTHER WEST ACROSS MN. MEANWHILE...THE ECMWF IS MUCH
MORE OPEN WITH THE TROUGH...AND INTERACTS WITH THE SOUTHERN TROUGH
OVER WI.
FINALLY...THE NAM AND GFS ARE BOTH PRODUCING AROUND 1 INCH OF LIQUID
PRECIP ACROSS IL ON SATURDAY...WHICH COULD RESULT IN A LACK OF
MOISTURE AVAILABILITY THIS FAR NORTH.
OVERALL THINKING IS THAT THE WESTWARD TRENDS OF THE MODELS ARE
BELIEVABLE...ESPECIALLY AS THE GFS COMES INTO LINE WITH THE MORE
CONSISTENT ECMWF. THEREFORE...A BLEND OF THOSE TWO MODELS WAS USED
FOR THIS SYSTEM. THE TWO TRACK THE SFC LOW THROUGH SOUTHERN WI LATE
SATURDAY AFTERNOON...AND INTO NORTHERN LOWER MI BY SUNDAY MORNING.
EVEN THOUGH H8 TEMPS CREEP ABOVE FREEZING AHEAD OF THE SYSTEM ON
SATURDAY...DRY AIR UNDER THE DEPARTING RIDGE WILL KEEP WET BULB
TEMPS BELOW FREEZING THROUGHOUT THE COLUMN. THERMAL PROFILES SUGGEST
A VERY WET SNOWFALL FOR THE CWA...WITH RAIN MIXING IN ACROSS THE
SOUTH CENTRAL AND EAST NEAR LAKE MICHIGAN. THOUGH THERE ARE SO MANY
DISCREPANCIES AMONG THE MODELS...THERE IS FAIRLY GOOD AGREEMENT THAT
A SHIELD OF MODERATE SNOW WILL MOVE NORTHEASTWARD THROUGH THE
CWA...BEGINNING SATURDAY MORNING NEAR THE MI/WI BORDER...AND
SATURDAY AFTERNOON ALONG LAKE SUPERIOR. PINPOINTING ANY AREAS FOR
ENHANCED SNOWFALL ATTM IS QUITE DIFFICULT...BUT THERE IS A STRONG
SIGNAL OF A H8-H7 FRONTOGENESIS BAND JUST NORTH OF THE LEFT EXIT OF
THE UPPER JET...WHEREVER THOSE FEATURES END UP.
NOT LOOKING LIKE WE WILL REACH WARNING CRITERIA (6IN/12HR)
SNOWFALL...BUT SNOW COULD ACCUMULATE QUICKLY AT TIMES ON SATURDAY.
GIVEN THE WATER CONTENT OF THE SNOW...THINGS COULD GET SLOPPY ACROSS
THE CWA.
SUNDAY THROUGH WEDNESDAY...THE FORECAST BECOMES MUDDLED BY THE END
OF THE WEEKEND AS THE MID-LEVEL LOW RESPONSIBLE FOR SATURDAYS SYSTEM
BECOMES WRAPPED UP ACROSS ONTARIO. THIS WILL PUT UPPER MI IN WEAK
NORTH TO NORTHWEST FLOW THROUGH MUCH OF THE REMAINDER OF THE PERIOD.
THE MAIN RESERVOIR OF COLD AIR IS CURRENTLY WELL TO THE NORTH ACROSS
THE ARCTIC AND SIBERIA...AND NOT REALLY A MAJOR FACTOR FOR LAKE
ENHANCEMENT/LAKE EFFECT OVER THE NEXT WEEK. THE COLDEST H8 AIR
BEHIND THE SYSTEM WILL MOVE ACROSS LAKE SUPERIOR SUNDAY NIGHT. EVEN
THEN...TEMPS ARE STILL ONLY AS LOW AS -10C. ALSO...INVERSION LEVELS
ARE ONLY ABOUT 4-5KFT FOR MUCH OF THE PERIOD. THE EXPECTATION IS
THAT THERE WILL BE INTERMITTENT SNOW SHOWERS...MAINLY NEAR LAKE
SUPERIOR...INTO THE MIDDLE OF NEXT WEEK. ACCUMULATIONS WILL BE LIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 427 PM EST WED DEC 12 2012
EXPECT VFR CONDITIONS INITIALLY AT ALL TAF SITES. A GUSTY SOUTH WIND
WILL DEVELOP LATE AFTERNOON AS THE PRES GRAD TIGHTENS AHEAD OF A NRN
PLAINS TROUGH. WILL INCLUDE LLWS AT ALL SITES TONIGHT AS A LOW-LVL
JET MAX MOVES ACROSS THE AREA. A BAND OF SNOW DEVELOPING AHEAD OF AN
APPROACHING UPPER DISTURBANCE IS FCST TO MOVE ACROSS THE KEWEENAW
PENINSULA AFT 14Z AND COULD BRING IFR CONDITIONS TO KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 PM EST WED DEC 12 2012
EXPECT SOUTH WINDS TO INCREASE OVER MOST OF LK SUPERIOR LATE THIS
AFTN AND ESPECIALLY TONIGHT. GUSTS TO GALES POSSIBLE EAST...BUT NOT
FREQUENT/STRONG ENOUGH TO ISSUE GALE WARNING. WINDS DIMINISH
STEADILY BLO 20 KTS LATER THURSDAY INTO THURSDAY NIGHT AS A WEAK
TROUGH CROSSES THE LAKE. WINDS STAY BLO 20 KTS THROUGH FRIDAY NIGHT
AS PRESSURE GRADIENT IS WEAK.
A LOW PRESSURE SYSTEM DEVELOPING IN THE PLAINS STILL ON TRACK TO
PUSH INTO WESTERN GREAT LAKES LATE SATURDAY INTO SUNDAY WHILE HIGH
PRESSURE MOVES ACROSS NEW ENGLAND. WINDS SHOULD INCREASE FROM THE
EAST TO 30 KTS LATE SATURDAY OVER LAKE SUPERIOR. EXACT TRACK AND
DEPTH OF SFC LOW REMAINS UNCERTAIN THOUGH SO KEPT WINDS BELOW GALE
IN THIS FORECAST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
GALE WARNING UNTIL 7 AM EST THURSDAY FOR LMZ248-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...TK
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DULUTH MN
310 PM CST WED DEC 12 2012
.SHORT TERM.../NOW - THURSDAY NIGHT/
THE FOCUSES FOR THIS FORECAST INCLUDE CHANCES OF LIGHT SNOW
THROUGH THIS EVENING...AND AGAIN FOR LATE TONIGHT INTO THURSDAY
AFTERNOON...BOTH OF WHICH MAINLY AFFECT THE NORTHERN TIER OF NE
MINNESOTA COUNTIES.
LIGHT SNOW WILL CONTINUE TO BE POSSIBLE ACROSS PARTS OF THE FAR
NORTHERN FA...MAINLY FAR NE MINNESOTA...THROUGH THIS EVENING DUE
TO THE WARM SOUTHERLY FLOW OVER A PASSING INVERTED TROUGH.
HOWEVER...MOST OF THE SNOW WILL FALL IN ONTARIO. ADDED PATCHY FOG
TO THE FAR NORTH SHORE OF THE ARROWHEAD THROUGH EARLY THIS EVENING
DUE TO THE ONSHORE WINDS WITH LONG FETCH...BUT THE FOG SHOULD
BEGIN TO DISSIPATE LATER THIS EVENING WHEN THE WIND DIRECTION
CHANGES. AS THE INVERTED TROUGH MOVES THROUGH THE FA TONIGHT...THE
SOUTHERLY WINDS WILL SUBSIDE AND BEGIN TO BECOME NORTHERLY. CLOUD
COVER WILL HELP PROP UP OVERNIGHT TEMPERATURES WITH LOWS MAINLY IN
THE TEENS AND TWENTIES...EXCEPT FOR SINGLE DIGITS IN THE FAR NW
FA.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT ABOUT A FRONTOGENETICAL
BAND OF LIGHT SNOW MOVING IN FROM NW MINNESOTA INTO NE MINNESOTA
LATE TONIGHT AND TOMORROW MORNING. THIS BAND OF LIGHT SNOW NORTH
OF THE STATIONARY FRONT COULD LINGER INTO THURSDAY AFTERNOON. MOST
AFFECTED AREAS ACROSS NE MINNESOTA WILL PROBABLY GET AT LEAST A
COUPLE TENTHS OF AN INCH...BUT WOULD NOT BE SURPRISED BY IF SOME
AREAS GET AROUND AN INCH. EXPECT A CLOUDY DAY...EXCEPT IN PARTS OF
THE FAR SE FA WHERE THERE SHOULD BE SOME PEAKS OF SUNSHINE. HIGH
TEMPERATURES SHOULD RANGE FROM THE LOW 30S ACROSS THE SE FA TO THE
TEENS IN THE NW FA.
HIGH PRESSURE WILL MOVE INTO THE NORTHLAND THURSDAY NIGHT...SO
BESIDES SOME POSSIBLE LINGERING LIGHT SNOW OVER THE
ARROWHEAD...THE REST OF THE FA SHOULD BE DRY. THE PARTLY TO MOSTLY
CLOUDY SKIES WILL HELP PROP UP TEMPERATURES. OVERNIGHT LOWS WILL
RANGE FROM THE UPPER TEENS IN THE SE FA TO THE LOWER SINGLE DIGITS
IN THE NW FA.
.LONG TERM.../FRIDAY - WEDNESDAY/
FOCUS DURING THIS PERIOD WILL BE ON A SYSTEM BRINGING
PRECIPITATION TO THE NORTHLAND THIS WEEKEND...POSSIBLY A MIX
FRIDAY NIGHT INTO SATURDAY MORNING. THE MODELS ARE IN PRETTY GOOD
AGREEMENT WITH THE SYSTEM THIS WEEKEND...AND A BLEND OF THE GFS
AND ECMWF WAS USED FOR MOST OF THE FORECAST DETAILS. THE NAM IS
FURTHER NORTH WITH THE TRACK...AND IS WARMER IN THE LOW LEVELS AS
A RESULT.
THE UPPER LEVEL SYSTEM OF CONCERN THIS WEEKEND WILL START OVER THE
CA/AZ/MEXICO AREA FRIDAY MORNING...THEN MOVE NORTHEAST TOWARD
THE NORTHLAND. FRIDAY WILL BE DRY OVER THE REGION. WARM AIR
ADVECTION AND THE APPROACHING UPPER TROUGH MAY BE ENOUGH TO CAUSE
SOME LIGHT PRECIPITATION LATE FRIDAY NIGHT...MAINLY OVER THE
SOUTHERN HALF OF THE CWA. PRECIPITATION TYPE IS IN QUESTION...AS
THE MODELS DO SHOW A WARM NOSE WHICH COULD CAUSE A WINTRY MIX OF
SNOW/FREEZING RAIN OR SLEET FRIDAY NIGHT/SATURDAY MORNING OVER
SOUTHERN AREAS. SEVERAL OF THE MODELS HAVE TRENDED A BIT FURTHER
NORTH WITH THIS SYSTEM WHICH DOES TWO THINGS 1) BRINGS A BETTER
CHANCE FOR PRECIPITATION INTO THE NORTHLAND AND 2) BRINGS IN
WARMER LOW LEVEL TEMPERATURES COMPLICATING THE PRECIPITATION TYPE
FORECAST. AS THE UPPER TROUGH AND SURFACE LOW MOVE OVER WISCONSIN
SATURDAY...PRECIPITATION SHOULD BECOME MORE WIDESPREAD AND BOTH
THE GFS AND ECMWF SUGGEST MAINLY SNOW WILL FALL DURING THE DAY
SATURDAY. AT THIS POINT...IT APPEARS SEVERAL INCHES OF SNOW WILL
BE POSSIBLE BY LATE SATURDAY EVENING...WITH THE BEST CHANCE
OCCURRING OVER NORTHWEST WISCONSIN. THE STRONGEST FORCING LOOKS TO
REMAIN SOUTH OF THE NORTHLAND...AND AT THIS POINT THERE DOES NOT
LOOK TO BE A SIGNIFICANT CONTRIBUTION OF LIFT FROM FGEN. WARMER
TEMPERATURES AT 850MB ALSO MEANS ANY LAKE CONTRIBUTION WILL BE
QUITE LIMITED. IT`S JUST TOO EARLY TO FORECAST SPECIFIC SNOW
AMOUNTS...AND DETAILS WILL BE ADDED LATER. THOSE WITH TRAVEL PLANS
OVER THE WEEKEND SHOULD MONITOR LATER FORECASTS AND STATEMENTS. WE
EXPECT HIGHS SATURDAY NEAR 30 OVER THE FAR NORTH...AND THE LOWER
THIRTIES OVER NORTHWEST WISCONSIN.
THE REST OF THE EXTENDED PERIOD LOOKS RELATIVELY QUIET AND WE HAVE
PERIODIC CHANCES FOR LIGHT SNOW. TEMPERATURES SHOULD BE SEVERAL
DEGREES ABOVE NORMAL THIS WEEKEND...THEN COOL TO NORMAL BY TUESDAY
INTO WEDNESDAY.
&&
.AVIATION.../18Z TAF ISSUANCE/
MAINLY VFR CONDITIONS COVERED THE NORTHLAND AS OF LATE
MORNING...WITH SOME LOWER CEILINGS AND SOME LIGHT SNOW ALONG THE
NORTH SHORE DUE TO ONSHORE WINDS THERE. WAA CONTINUED OVER THE
NORTHLAND...AND STILL MAY LEAD TO SOME LIGHT SNOW AND LOWERING
CEILINGS OVER THE FAR NORTH THIS AFTERNOON. WE DID DELAY THE LOWER
CEILINGS...AND REMOVED THE MENTION FROM KDLH. KDLH WAS
EXPERIENCING A SCATTERED DECK AS LOW AS 400FT THIS MORNING...BUT
AS TEMPS WARM THIS AFTERNOON...LAKE GENERATED CLOUDS SHOULD BECOME
MORE SCARCE. THE RAP AND NAM BOTH SUGGEST LOWER CEILINGS WILL
DEVELOP OVER THE NORTH...MAINLY AFFECTING KINL.
TONIGHT...WE COULD SEE SOME FOG IN SPOTS. A WEAK WAVE WILL MOVE
THROUGH THE AREA AS WELL...AND WITH THIS THERMAL GRADIENT IN
PLACE...SOME LIGHT SNOW WILL BE POSSIBLE. WE ADDED THE MENTION TO
ALL TAFS EXCEPT KHYR. SOME LOWER CEILINGS...WILL ALSO BECOME MORE
LIKELY AS THE NIGHT PROGRESSES. WINDS WILL TURN TO THE NORTH TO
NORTHEAST LATE TONIGHT INTO THURSDAY MORNING.
&&
.POINT TEMPS/POPS...
DLH 20 30 15 28 / 20 20 10 10
INL 7 17 4 21 / 10 10 10 10
BRD 17 27 11 28 / 20 10 10 10
HYR 22 34 16 33 / 0 0 0 10
ASX 25 34 21 32 / 0 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 4 AM CST THURSDAY
FOR LSZ140-141.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM....MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1143 AM CST WED DEC 12 2012
.AVIATION...18Z TAFS
MAINLY VFR CONDITIONS COVERED THE NORTHLAND AS OF LATE
MORNING...WITH SOME LOWER CEILINGS AND SOME LIGHT SNOW ALONG THE
NORTH SHORE DUE TO ONSHORE WINDS THERE. WAA CONTINUED OVER THE
NORTHLAND...AND STILL MAY LEAD TO SOME LIGHT SNOW AND LOWERING
CEILINGS OVER THE FAR NORTH THIS AFTERNOON. WE DID DELAY THE LOWER
CEILINGS...AND REMOVED THE MENTION FROM KDLH. KDLH WAS
EXPERIENCING A SCATTERED DECK AS LOW AS 400FT THIS MORNING...BUT AS
TEMPS WARM THIS AFTERNOON...LAKE GENERATED CLOUDS SHOULD BECOME
MORE SCARCE. THE RAP AND NAM BOTH SUGGEST LOWER CEILINGS WILL
DEVELOP OVER THE NORTH...MAINLY AFFECTING KINL.
TONIGHT...WE COULD SEE SOME FOG IN SPOTS. A WEAK WAVE WILL MOVE
THROUGH THE AREA AS WELL...AND WITH THIS THERMAL GRADIENT IN
PLACE...SOME LIGHT SNOW WILL BE POSSIBLE. WE ADDED THE MENTION TO
ALL TAFS EXCEPT KHYR. SOME LOWER CEILINGS...WILL ALSO BECOME MORE
LIKELY AS THE NIGHT PROGRESSES. WINDS WILL TURN TO THE NORTH TO
NORTHEAST LATE TONIGHT INTO THURSDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 937 AM CST WED DEC 12 2012/
UPDATE...
MADE SOME UPDATES TO POPS AND WEATHER THROUGH TONIGHT TO BETTER
REFLECT THE BAND OF LIGHT SNOW IN NORTHWESTERN MINNESOTA AND NORTH
OF THE CANADIAN BORDER THAT WILL SLIDE EAST TODAY AND TONIGHT.
STILL THINK THIS WILL MAINLY AFFECT THE FAR NORTHERN FA WHERE SOME
AREAS MAY GET SEVERAL TENTHS OF AN INCH OF SNOW. OTHERWISE...THE
FORECAST LOOKS ON TRACK.
PREV DISCUSSION... /ISSUED 622 AM CST WED DEC 12 2012/
AVIATION.../12Z TAF ISSUANCE/
WIDESPREAD VFR CONDITIONS WILL BE FOUND ACROSS THE AREA THROUGHOUT
THE TAF PERIOD...BUT THERE SHOULD ALSO BE SOME BATCHES OF LOWER
CLOUDS DEVELOPING THROUGHOUT THE PERIOD AS WELL. SOME MVFR CIGS
AND EVEN SOME MVFR VSBYS...ESPECIALLY IN THE NORTH...WILL BE
POSSIBLE.
PREV DISCUSSION... /ISSUED 352 AM CST WED DEC 12 2012/
SHORT TERM...
TODAY THROUGH THURSDAY AFTERNOON...
MAIN SHORT TERM CONCERNS REMAIN FOCUSED AROUND THE POTENTIAL FOR
SNOW SHOWERS THIS AFTERNOON...AND AGAIN LATE TONIGHT/EARLY
THURSDAY...BOTH TIMES ACROSS THE NRN TIER COUNTIES OF NE MN. ONLY
LIGHT ACCUMULATIONS ARE EXPECTED.
BROAD CYCLONIC FLOW CONTINUES ACROSS MUCH OF THE CONUS WITH A
SHARP 500MB TROUGH DROPPING SWD THROUGH THE PAC NW AND INTO THE
NRN ROCKIES...ALONG WITH A WEAK EMBEDDED S/W AND DEVELOPING SFC
INVERTED TROUGH MOVING INTO THE WRN DAKOTAS EARLY THIS MORNING.
THIS SURFACE TROUGH WILL CONTINUE TO MOVE EWD INTO WRN MN THIS
MORNING AND AT THE SAME TIME DRAW UP SLIGHTLY WARMER AIR FROM THE
SOUTH AS SFC WINDS SHIFT TO THE S/SW. THIS SYSTEM WILL HAVE WEAK-
MDT UPPER LEVEL SUPPORT AS A 90KT JET TRANSLATES EWD THROUGH THE
NRN PLAINS/UPPER MIDWEST...AND AREAS OF NE MN REMAIN IN THE LEFT
EXIT REGION OF THE JET. IT APPEARS THERE WILL ALSO BE A FAVORABLE
AREA OF 925-850MB F-GEN ALONG THE LEADING EDGE OF THIS SFC TROUGH.
THIS WILL BE A FAIRLY QUICK MOVING SYSTEM...AND ONLY DROP AN INCH
OR SO OF SNOW FROM INL TO ELO TO GNA...WITH LIGHTER AMTS FURTHER
SOUTH.
A SECONDARY JET MAX WILL EJECT NEWD OUT OF THE SWRN U.S. TONIGHT
ALONG WITH ANOTHER S/W FROM THE NRN PLAINS. THESE TWO FEATURES
WILL COMBINE WITH THE SLOW-MOVING STATIONARY SFC TROUGH LINGERING
OVER THE NORTHLAND AND PRODUCE ANOTHER ROUND OF SNOW SHOWERS. THIS
SYSTEM IS EXPECTED TO BE FAST-MOVING AS WELL...AND DROP ANOTHER
INCH OR SO OF SNOW SLIGHTLY FURTHER SOUTH. COULD SEE THE MOST
SNOW...AROUND 1-2 INCHES...WITHIN AN AREA FROM PARK FALLS TO HIBBING
TO LUTSEN. MOST OF THE SNOW SHOWERS SHOULD END BY LATE THUR
AFTERNOON.
TEMPERATURE THROUGH THE SHORT TERM WILL BE SLIGHTLY MORE MILD THAN
THE PAST COUPLE DAYS WITH HIGHS IN THE 20S AND LOWER 30S AND
OVERNIGHT LOWS IN THE TEENS.
LONG TERM...
THURSDAY NIGHT THROUGH WEDNESDAY...
THIS TIME PERIOD IS SHAPING UP TO BE A POTENTIALLY ACTIVE PERIOD
ONCE AGAIN...AS WE FOCUS ON THE POTENTIAL SNOWFALL FOR THE
WEEKEND. THE GFS AND GEM PARTICULARLY ARE NOTING SOME
PRECIPITATION LINGERING IN THE MN ARROWHEAD FOR THURSDAY
EVENING...ESPECIALLY FOR COASTAL AREAS BEHIND A DEPARTING FRONTAL
BOUNDARY AND UPPER LEVEL SHORTWAVE. FRIDAY WILL GENERALLY BE
QUIET...WITH WAA INITIATING AHEAD OF A DEEP SW TROUGH. THE GEM IS
HINTING AT SOME LIGHT PRECIPITATION ACROSS THE CWA ON FRIDAY...AND
CANNOT RULE IT OUT BUT WILL LEAVE IT DRY AT THIS TIME.
ACCUMULATING SNOWFALL AND POSSIBLY SOME LIGHT FREEZING RAIN OR
DRIZZLE WILL BE THE MAIN STORY FOR SATURDAY INTO SUNDAY. THE GFS
GENERALLY KEEPS THE PRECIPITATION SOUTH AND EAST OF THE CWA...BUT
THE NAM...GEM AND ECMWF ALL BRING A FAIRLY LARGE AREA OF QPF
ACROSS THE CWA WITH THE POTENTIAL FOR SEVERAL INCHES OF
ACCUMULATION. THE SYSTEM LOOKS TO BE FAIRLY WARM...SO THERE COULD
BE SOME LIGHT FREEZING RAIN OR DRIZZLE AS WELL. WILL NEED TO KEEP
A CLOSE EYE ON THIS SYSTEM AS IT HAS THE POTENTIAL TO COMPLICATE
WEEKEND TRAVEL. AFTER THIS WEEKEND...IT LOOKS FAIRLY QUIET AGAIN
INTO MIDWEEK. HIGH TEMPERATURES WILL GENERALLY BE IN THE 20S AND
30S THROUGHOUT THE EXTENDED TIME PERIOD WITH LOWS RANGING FROM THE
TEENS TO AROUND 30.
&&
.POINT TEMPS/POPS...
DLH 27 20 29 15 / 0 20 10 10
INL 20 8 15 5 / 60 10 20 10
BRD 29 18 26 12 / 0 20 10 0
HYR 33 22 32 17 / 0 0 10 10
ASX 33 25 34 22 / 0 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GROCHOCINSKI
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS BILLINGS MT
319 PM MST WED DEC 12 2012
.SHORT TERM...VALID FOR THU AND FRI...
A CHALLENGING FORECAST DEALING WITH POTENTIAL LINGERING SNOW THIS
EVENING WILL EASE INTO A QUIET AND SEASONABLY COOL PERIOD FOR THE
END OF THE WEEK BENEATH SPLIT FLOW ALOFT.
TONIGHT...EXTRAPOLATING THE DISTINCT DRYING OBSERVED ON AFTERNOON
MOISTURE CHANNEL IMAGES IN ID AND SOUTHWESTERN MT SUGGESTS AN END
TO PRECIPITATION AT LIVINGSTON BY 00 UTC...AND AROUND BILLINGS BY
ABOUT 03 UTC. OF COURSE...THE LEADING EDGE OF THAT DRYING IS TIED
TO A STEEPENING OF MID-LEVEL LAPSE RATES...SO UPSTREAM SNOW RATES
HAVE ACTUALLY INTENSIFIED FOR A SHORT TIME JUST AHEAD OF IT. WITH
THAT IN MIND...WE KEPT LIKELY POPS IN PLACE EVEN AT BILLINGS THIS
EVENING...EVEN THOUGH THE MAIN BAND OF MOISTURE UP THROUGH 22 UTC
HAS BEEN NORTH OF THE CITY. THE SHIELD OF PRECIPITATION WHICH HAS
BEEN GOING ON NORTH AND EVEN NORTHEAST OF BILLINGS TODAY SEEMS TO
BE DRIVEN BY SOME WEAK FRONTOGENESIS...BUT THE BETTER FORCING HAS
BEEN OBSERVED ON ISENTROPIC SURFACES...WITH PRESSURE ADVECTION AT
THE 290 K LEVEL SIGNIFICANT FROM ROUNDUP TO FORSYTH. THIS FORCING
ON ISENTROPIC SURFACES EVEN DIMINISHES TOWARD 00 UTC...BUT WE DID
LEAVE IN LIKELY POPS ROUGHLY ALONG AND NORTH OF INTERSTATE 94 FOR
THE EVENING BASED ON RECENT RADAR TRENDS...THE LAST FEW HRRR RUNS
AND THE 12 UTC GFS...WHICH HAS SIMULATED THIS MOISTURE WELL. SOME
ROADS COULD BE SLICK...MUCH LIKE HAS BEEN SEEN TODAY IN THE SPOTS
THAT HAVE RECEIVED SNOW INSTEAD OF A MIX OF RAIN AND SNOW...WHICH
IS WHY WE WILL CONTINUE MENTIONING SOME TRAVEL IMPACTS OVER PARTS
OF THE AREA INTO THE EVENING. WE DO NOT ANTICIPATE ENOUGH SNOW TO
NECESSITATE A WINTER WEATHER ADVISORY ANYWHERE...BUT WE WILL NEED
TO KEEP A CLOSE EYE ON THAT POTENTIAL THIS EVENING.
BEYOND MIDNIGHT...WE EXPECT MOST AREAS TO BE DRY...MUCH LIKE MOST
12 UTC GUIDANCE SUGGESTS. WE LINGERED SOME 20 AND 30 PERCENT POPS
IN SOUTHEASTERN MT THOUGH. THE 12 UTC MET GUIDANCE SUGGESTS THERE
MAY BE SOME FOG WHERE PRECIPITATION FELL TODAY...AND BUFKIT-BASED
SOUNDING TOOLS ALSO SUPPORT THAT RISK. THUS...PATCHY FOG IS SHOWN
IN THE FORECAST AFTER 06 UTC FOR HARLOWTON...ROUNDUP...MILES CITY
AND EVEN BAKER. IF A TENTH OF AN INCH OF MOISTURE OR MORE HAPPENS
TO FALL IN BILLINGS THIS EVENING...THEN WE WILL NEED TO GIVE SOME
CONSIDERATION TO ADDING FOG TO THE FORECAST THERE TOO.
THU...WEAK LOW- AND MID-LEVEL WARM AIR ADVECTION WILL OCCUR...BUT
FORECAST SOUNDINGS SUGGEST BOUNDARY LAYER MIXING WILL BE SEVERELY
LIMITED BENEATH SPLIT FLOW ALOFT. THIS ENVIRONMENT WILL FAVOR THE
PERSISTENCE OF ANY FOG THAT FORMS TONIGHT INTO THU MORNING...WITH
SOME POTENTIAL FOR STRATUS TO LINGER OVER SOUTHEASTERN MT ALL DAY
LIKE THE 12 UTC MET MOS SUGGESTS AT MILES CITY AND BAKER. WE KEPT
HIGHS IN THOSE SPOTS COOLER THAN THE 12 UTC BIAS-CORRECTED FLAVOR
OF THE MULTI-MODEL CONSENSUS IN RESPECT TO THAT POTENTIAL...WHILE
INCREASING HIGHS SLIGHTLY IN PLACES LIKE BILLINGS IN ORDER TO TAG
ALONG WITH THAT GUIDANCE WHERE SUNSHINE IS EXPECTED. FINALLY...WE
MAINTAINED CONTINUITY IN SHOWING SOME SLIGHT CHANCE POPS UNTIL 18
UTC OVER SOUTHEASTERN MT AHEAD OF THE AXIS OF THE NORTHERN STREAM
500-HPA TROUGH...BUT CONFIDENCE IN PRECIPITATION IS VERY LOW.
FRI...LOW-LEVEL FLOW WILL BECOME MORE SOUTHWESTERLY IN ADVANCE OF
A MODEST SURFACE COLD FRONT THAT THE 12 UTC GFS...NAM...AND ECMWF
ALL SWING THROUGH THE AREA FRI EVENING. THIS SCENARIO SHOULD HELP
ADD A FEW MORE DEGREES F TO HIGHS OVER THOSE EXPECTED THU...WHICH
IS WHAT THE 12 UTC BIAS-CORRECTED MULTI-MODEL CONSENSUS PICKED UP
ON AS WELL. THE FRONTAL PASSAGE TIED TO A WEAK 500-HPA SHORT WAVE
IN THE NORTHERN STREAM OF THE WESTERLIES LOOKS DRY. HOWEVER...ONE
AREA WHERE WE MAY NEED TO CONSIDER SOME LOW POPS DOWN THE ROAD IS
ALONG THE FOOTHILLS BY LATE FRI NIGHT AS WEAK UPSLOPE DEVELOPS AS
A SURFACE HIGH DROPS INTO CENTRAL AND EASTERN MT. THERE WAS A BIT
OF A SIGNAL IN THE 12 UTC GFS FOR THAT...BUT NOT ENOUGH FOR US TO
PUT LOWER-ELEVATION POPS IN THE FORECAST YET. THE 09 UTC SREF WAS
MORE AGGRESSIVE WITH SOME LIGHT PRECIPITATION IN SOUTH CENTRAL MT
LATE FRI NIGHT...BUT IT IS ALSO AN OUTLIER SOLUTION. SCHULTZ
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
DRY CONDITIONS WILL PREVAIL FOR MOST LOCATIONS ON SATURDAY. AN
UPPER-LEVEL TROUGH WILL DIVE SOUTH ACROSS THE REGION DURING THIS
TIME. THE STRONGEST FORCING SHOULD TRACK SOUTH OF THE CWA. THE
FIRST IN A SERIES OF DISTURBANCES WILL MOVE ACROSS THE CWA ON
SUNDAY. BROAD-BRUSHED LOW POPS DURING THIS TIME. A SECOND WAVE
WILL TRACK ACROSS THE CWA ON MONDAY. AGAIN...KEPT POPS LOW AND
BROAD-BRUSHED. TUESDAY WILL GENERALLY BE DRY. A THIRD WAVE WILL
IMPACT THE CWA TUESDAY NIGHT INTO WEDNESDAY. BLENDED MAX/MIN
TEMPERATURES WITH THE BEST-PERFORMING 12Z GUIDANCE...ALLBLEND /
MOSGUIDE. TEMPERATURES WILL GENERALLY BE SEASONAL THROUGHOUT THE
PERIOD. BRS
&&
.AVIATION...
PRECIPITATION WILL CONTINUE OVER THE MOUNTAINS THROUGHOUT THE TAF
PERIOD. PRECIPITATION WILL CONTINUE OVER THE PLAINS THROUGH
TONIGHT. EXPECT BRIEF MVFR/IFR CONDITIONS. PRECIPITATION WILL
DIMINISH OVERNIGHT. PATCHY FOG WILL BE POSSIBLE EARLY THURSDAY
MORNING. VFR CONDITIONS WILL PREVAIL ON THURSDAY. BRS
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 023/040 021/041 020/037 019/038 021/036 024/040 021/035
61/B 01/U 11/B 02/J 22/J 11/B 22/J
LVM 022/037 019/040 018/033 024/035 019/033 026/036 020/034
41/B 01/B 11/B 12/W 22/J 11/N 22/J
HDN 023/038 017/039 016/035 015/037 019/037 019/040 018/036
51/B 00/B 11/B 01/B 22/J 11/B 22/J
MLS 021/033 016/035 018/032 015/035 018/036 019/036 020/035
72/J 00/B 00/B 01/B 12/J 11/B 22/J
4BQ 019/036 017/037 017/034 015/036 017/036 018/036 018/037
22/J 00/B 00/B 01/U 12/J 11/B 22/J
BHK 019/031 013/036 016/031 015/033 016/033 017/035 018/036
52/J 00/B 00/B 01/B 12/J 11/B 22/J
SHR 019/036 016/037 013/033 015/035 015/034 017/037 016/032
20/B 00/B 11/B 01/B 22/J 11/B 22/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
233 PM EST WED DEC 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL PERSIST OVER THE AREA INTO SATURDAY. A FRONTAL
SYSTEM WILL THEN APPROACH THE NORTH CAROLINA MOUNTAINS EARLY SUNDAY
AND CROSS EAST OF THE FORECAST AREA BY EARLY MONDAY. ANOTHER FRONTAL
SYSTEM WILL APPROACH THE REGION ON TUESDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
STRONG UPPER DIVERGENCE IN THE ENTRANCE REGION OF A 130 KT POLAR JET
HAS RESULTED IN LIGHT RAIN OVER PARTS OF THE UPSTATE AND THE SRN NC
PIEDMONT. THE LATEST RUC SHOWS THE DIVERGENCE WEAKENING FOR A FEW
HOURS THIS AFTERNOON...THEN INCREASING OVER THE SRN HALF OF THE
FORECAST AREA AGAIN EARLY THIS EVENING AS A SHORT WAVE CURRENTLY
OVER MISSISSIPPI EJECTS QUICKLY TO THE NE. THE GFS ALSO HAS AN
IMPRESSIVE QPF MAX OVER THE SRN PART OF THE UPSTATE AND CHARLOTTE
METRO AREA FROM 00-06 UTC THIS EVENING. WHILE IT/S 0.25-0.50 INCH
RAINFALL AMOUNTS ARE ALMOST CERTAINLY TOO HIGH...LIGHT RAIN
SHOULD FILL BACK IN THIS EVENING ACROSS THE SAME AREAS THAT HAVE
BEEN SEEING IT THIS AFTERNOON. THIS WILL BASICALLY BE AREAS ALONG
AND SOUTH OF I-85. IT STILL APPEARS THAT THE RAIN WILL END BEFORE
TEMPERATURES FALL BELOW FREEZING TONIGHT AND I/M NOT ANTICIPATING
ANY P-TYPE PROBLEMS OVERNIGHT. EVEN DURING THE DAYLIGHT HOURS TODAY
THE PCPN SHOULD BE ALL RAIN. WHILE THE DUAL-POL HYDROMETEOR
CLASSIFICATION ALGORITHM IS SHOWING SOME MIXED PCPN OVER THE
CHARLOTTE METRO AREA...THIS IS UP AT 7KFT AND IS NOT REFLECTIVE OF
WHAT IS FALLING AT THE SFC. LAPS SOUNDINGS OVER THIS AREA SHOW AIR
TEMPS WELL ABOVE FREEZING IN THE LOWEST SEVERAL THOUSAND FEET OF THE
ATMOSPHERE.
CLOUDS WILL CLEAR OUT OF THE EASTERN ZONES EARLY TOMORROW AND WE
SHOULD SEE CLEAR BLUE SKIES AND SLIGHTLY BELOW NORMAL TEMPERATURES
FOR THURSDAY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 2 PM WEDNESDAY...SHORT RANGE MODELS INDICATE THAT THE
FORECAST AREA WILL REMAIN WITHIN THE CENTER OF 1025 MB SFC HIGH AND
UNDER DEEP RIDGING ALOFT. FORECAST SOUNDINGS INDICATE THAT WIDE
DEWPOINT DEPRESSIONS WILL EXIST FROM THE SFC TO THE
TROPOPAUSE...SUPPORTING A 0 PERCENT SKY COVER FORECAST FRIDAY
MORNING. HOWEVER...CIRRUS LEVEL MOISTURE WILL BEGIN TO INCREASE
DURING THE AFTERNOON...LIKELY SUPPORTING A FEW CONTRAILS OR THIN
CIRRUS. CALM WINDS...CLEAR SKY...AND DEEP DRY AIR WILL PROVIDE GOOD
RADIATIONAL COOLING CONDITIONS FRIDAY MORNING. USING A BLEND OF MOS
GUIDANCE...MIN TEMPERATURES SHOULD RANGE FROM THE MID 20S ACROSS THE
MTN VALLEYS TO THE L30S EAST. UNDER SUNNY TO MOSTLY SUNNY
CONDITIONS...HIGH TEMPERATURES ARE FORECAST TO RANGE FROM THE U50S
ACROSS THE MTNS TO THE L60S EAST.
FRIDAY NIGHT...CIRRUS CLOUD COVER WILL INCREASE THROUGH THE
NIGHT...POSSIBLY BECOMING GREATER THAN 5KFT THICK BY 12Z SAT. SFC
CONDITIONS WILL LIKELY REMAIN DRY WITH LIGHT AND VARIABLE TO CALM
WINDS. HOWEVER...THE INCREASING SKY COVER WILL FAVOR MIN
TEMPERATURES AROUND 5 DEGREES WARMER THAN EXPECTED FRIDAY MORNING.
ON SATURDAY...A COLD FRONT WILL APPROACH FROM THE WEST...LIKELY
REMAINING WEST OF THE APPALACHIAN THROUGH 0Z SUNDAY. HOWEVER...LIGHT
RETURN FLOW WILL DEVELOP ACROSS THE FORECAST AREA...RESULTING IN
WEAK WAA. FORECAST SOUNDINGS INDICATE THAT CLOUD BASES WILL LOWER TO
AROUND 10 KFT BY THE LATE AFTERNOON...REMAINING RATHER THICK ALOFT.
CLOUD COVER IS FORECAST TO BECOME MOSTLY CLOUDY BY THE AFTERNOON.
GIVEN THE WAA ON RETURN FLOW...TEMPERATURE GUIDANCE SUPPORTS HIGH
TEMPERATURES WITHIN A DEGREE OR TWO OF FRIDAY/S VALUES. A FEW PRE
FRONTAL RAIN SHOWERS MAY REACH THE EXTREME WESTERN NC MTNS DURING
THE EARLY EVENING HOURS ON SATURDAY...I WILL INDICATE CHC POPS WITH
LOW QPF.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM WEDNESDAY...A COMPLEX WX PATTERN IS EXPECTED IN THE
MEDIUM RANGE...AS SPLIT UPPER FLOW IN THE WEST WILL BE QUITE
ACTIVE...AND THE MODELS DISAGREE ON THE DETAILS.
SATURDAY NIGHT AND SUNDAY...ALREADY PLENTY OF DISAGREEMENT WITH A
LEADING LOW PRES SYSTEM LIFTING NE ACRS THE MID MS VLY TO THE GREAT
LAKES...DRAGGING A COLD FRONT ACRS THE TN VLY TO THE SRN
APPALACHIANS. THE 12Z GFS IS SIMILAR TO PREV FEW RUNS IN BEING
MOISTURE-STARVED...WITH MORE VEERED LLVL FLOW AND WEAK ISENT LIFT.
MEANWHILE...THE 00Z ECMWF CONTINUES TO BE MUCH WETTER...WITH DEEP
SWLY FLOW TRANSPORTING GULF MOISTURE AHEAD OF THE FRONT...WITH
PLENTY OF LLVL LIFT. THE HPC GUIDE TAKES A BLEND OF THE GFS AND
ECMWF WITH THIS SYSTEM...WHICH RESULTS IN GENERALLY LOW-END
POPS...EXCEPT IN THE WEST WHERE THE BEST MOISTURE AND FORCING WILL
BE. TEMPS ARE EXPECTED TO BE TOO WARM FOR ANY WINTRY PRECIP WITH
THIS FIRST FRONT.
BOTH THE GFS AND ECMWF TAKE SOUTHERN STREAM SHORTWAVE ENERGY ACRS
THE SOUTHERN PLAINS...INDUCING WEAK CYCLOGENESIS ALONG A STALLED
FRONTAL BNDRY INVOF THE MID SOUTH. BUT THEY DIFFER ON THE
TIMING...WITH THE ECMWF ABOUT 12 HOURS FASTER. AN HPC BLEND WITH
PREVIOUS FCST WAS USED...RESULTING IN A SHOTGUN 30-40 POP FOR THREE
PERIODS FROM MONDAY THRU TUESDAY. THEN THINGS DRY OUT QUICKLY
TUESDAY NIGHT THRU WEDNESDAY. THIS ALSO RESULTS IN NO WINTRY PRECIP
IN THE FCST...AS CENTER OF LOW PRES LIFTS NE...KEEPING THE FA IN THE
WARM SECTOR. THERE MAY BE INSTBY AND SHEAR FOR SEVERE WX ACRS
PORTIONS OF THE PIEDMONT IF THE LOW IS STRONG ENUF AND TAKES THIS
KIND OF TRACK. AS I TYPED THIS...THE 12Z ECMWF CAME IN. IT HAS
ANOTHER SOUTHERN STREAM SYSTEM QUICKLY DEVELOP TUESDAY AND CROSS TO
OUR SOUTH...TURNING INTO A NOREASTER THAT RIDES UP THE EAST COAST
TUESDAY NIGHT THRU THURSDAY. THIS IS A NEW DEVELOPMENT...SO IS NOT
IN THIS FCST PACKAGE.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...LIGHT RAIN WILL OVERSPREAD THE AIRFIELD BETWEEN 17 AND 18
UTC THIS AFTERNOON. CIGS SHOULD HOLD AT OR A LITTLE ABOVE 2000 FEET
AS THE PRECIPITATION STARTS. IN FACT PERIODS OF LIGHT RAIN AND MVFR
CIGS WILL CONTINUE UNTIL AFTER MIDNIGHT. LATE TONIGHT CIGS WILL
CLEAR. WINDS WILL REMAIN OUT OF THE NE THROUGH THE VALID PERIOD OF
THE TAF. SPEEDS WILL AVERAGE AROUND 10 KTS...WITH OCCASIONAL GUSTS
UP TO 18 KTS.
ELSEWHERE...MVFR CIGS CONTINUE FROM KCLT TO JUST SOUTH OF KGMU AND
KGSP AND ACROSS KAND. THERE IS A NARROW BAND OF 4KFT VFR CIGS NORTH
OF THAT LINE...AND THEN JUST HIGH CIGS NORTH OF THAT. KHKY AND KAVL
SHOULD GENERALLY ONLY SEE HIGH CLOUDS INTO TONIGHT. OVER THE
UPSTATE...KGSP AND KGMU SHOULD HOLD NEAR 4KFT...BUT A LOWER CIG IS
POSSIBLE AT TIMES. THERE WILL ALSO BE PERIODS OF LIGHT RAIN...THOUGH
THE BULK OF THE RAIN WILL FALL SOUTH OF THE AIRFIELDS. WINDS WILL BE
OUT OF THE NE THROUGH THE TAF PERIOD AT SPEEDS OF 8 TO 10 KTS.
OUTLOOK...VFR CONDITIONS ARE EXPECTED THURSDAY AND FRIDAY THANKS TO
HIGH PRESSURE BUILDING IN FROM THE WEST. MOISTURE AND THE CHANCES OF
RESTRICTIONS WILL INCREASE OVER THE WEEKEND.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...MCAVOY
SHORT TERM...NED
LONG TERM...ARK
AVIATION...MCAVOY