Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 02/07/12
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1024 AM MST SUN FEB 5 2012
.SHORT TERM /REST OF TODAY THROUGH MONDAY NIGHT/...
QUICK UPDATE TO INCREASE POPS ACROSS THE SOUTHWEST SAN
JUANS AND ADJACENT SOUTHERN VALLEYS WHERE SCATTERED SNOW SHOWERS
CONTINUE. ACCUMULATIONS WILL BE ON THE LIGHT SIDE...BUT WEBCAMS
INDICATING SOME IMPACT ON ROAD SURFACES. LATEST RUC SUGGESTS THIS
ACTIVITY WILL CONTINUE FOR A FEW MORE HOURS IN SHALLOW UPSLOPE
FLOW INTO THE SAN JUANS.
CUT-OFF UPPER LOW WAS FORMING OVER WRN UT EARLY THIS MORNING IN AN
ELONGATED AREA OF LOW PRESSURE THAT STRETCHED FROM NV TO KS. THIS
UPPER LOW WILL STAY OVER UT THROUGH TONIGHT...WHEN A SHORTWAVE
DROPPING OUT OF CENTRAL CANADA AND A PACIFIC TROUGH REACHING THE
COAST FINALLY BEGIN TO PULL/PUSH IT EASTWARD ACROSS COLORADO ON
MONDAY-MONDAY NIGHT. THIS WILL KEEP AREAS OF CLOUDS AND A CHANCE OF
SNOW SHOWERS PRESENT THROUGH MONDAY NIGHT...AND MODELS ARE IN GOOD
AGREEMENT ON THIS SCENARIO. EMBEDDED DISTURBANCES ROTATING
COUNTERCLOCKWISE AROUND THE LOW WILL CROSS SE UT/SW CO AND FOCUS THE
CHANCE OF PRECIP MOSTLY ACROSS THE SOUTH HALF OF OUR FORECAST AREA.
THE BEST CHANCE LOOKS TO BE SUNDAY NIGHT AND MONDAY WHEN PERHAPS THE
MOST ENERGETIC DISTURBANCE PASSES. MOISTURE SHOULD BE LIMITED AS
THERE IS NO MOISTURE TAP TO THIS SYSTEM...BUT TEMPERATURES ALOFT
WILL BE NEAR OR IN THE FAVORABLE REGIME FOR SNOW CRYSTAL
GROWTH...AND SNOW SHOWERS COULD PRODUCE LOCALIZED ACCUMULATIONS OF A
COUPLE INCHES OVER THE SOUTHERN AND CENTRAL MOUNTAINS. SNOW CHANCES
WILL BE ON THE DECREASE MONDAY NIGHT AS THE LOW MOVES BY.
TEMPERATURES LOOK TO RUN NEAR PERSISTENCE TO A FEW DEGREES COOLER.
.LONG TERM /TUESDAY THROUGH SATURDAY/...
GOOD AGREEMENT BETWEEN THE MEDIUM RANGE MODELS THROUGH THE ENTIRE
LONG TERM PERIOD. STRONG PACIFIC WAVE BREAKS OFF FROM THE MAIN
WESTERLIES AND DIVES SOUTHEAST ALONG THE CALIFORNIA AND BAJA
COAST ON WEDNESDAY AND THURSDAY...MISSING OUR FORECAST AREA ALTHOUGH
SOUTHEAST UTAH MAY SEE AN INCREASE OF CLOUDS. BUT THERE ARE SOME
SUBTLE DIFFERENCES THAT DOES HAVE SMALL IMPLICATIONS FOR OUR FORECAST
AREA. THE GFS SHOWS SOME SPOTTY LIGHT PCPN WITH A WEAK SHORT WAVE
BRUSHING NW COLORADO ON WEDNESDAY AFTERNOON AND EVENING. THE
LATEST ECMWF SHOW A SIMILAR SOLUTION BUT THE SPOTTY PCPN OCCURS THE
NEXT DAY. THE CANADIAN MODEL SHOWS STRONGER PACIFIC ENERGY
UNDERCUTTING THE STRONG AMPLIFIED RIDGE OVER WRN CANADA. NONE OF
THESE SOLUTIONS CAN BE CONSIDERED A SIGNIFICANT EVENT...BUT
SUGGEST THAT THE UPCOMING WEEK MAY NOT BE COMPLETELY DRY. RUN TO RUN
MODEL CONSISTENCY CAN BE BETTER AND BELIEVE THAT FUTURE MODEL
SOLUTIONS WILL OFFER MORE DIFFERENCES. EXTENDED GUIDANCE POPS
STAY BELOW 15 PERCENT AND WILL NOT DEVIATE FROM THIS AT THIS
TIME...ESSENTIALLY KEEPING THE GOING FORECAST DRY THROUGH DAYS 3
THROUGH 7. CONFIDENCE IS SO-SO AND IF MODELS SHOW SOME CONSISTENCY
WITH THE PASSING SHORT WAVE WEDNESDAY NIGHT AND THURSDAY TIME
FRAME...THEN CHANCE POPS FOR NW COLORADO WILL NEED TO BE
INTRODUCED.
&&
.AVIATION /FOR 18Z TAF ISSUANCE/...
AN UPPER LOW SPINS OVER EASTERN UTAH TODAY AND TONIGHT. WEAK LIFT
ASSOCIATED WITH THE LOW WILL COMBINE WITH A MOIST LAYER BETWEEN
10000 AND 14000FT MSL OVER THE REGION TO PRODUCE SCATTERED
MOUNTAIN SNOW SHOWERS. MORE WIDESPREAD SHOWERS ARE POSSIBLE OVER
THE SOUTHERN MTNS. MTN TOPS WILL BE OCNLY OBSCURED.
THE CHANCES FOR LESS THAN VFR CONDITIONS IS 30 PERCENT AT KASE
KMTJ KDRO KCEZ...WHILE KTEX WILL BE 50 PERCENT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...JDC/JAD
LONG TERM....PF
AVIATION.....JOE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
730 AM MST SUN FEB 5 2012
.UPDATE...QUICK UPDATE TO INCREASE POPS ACROSS THE SOUTHWEST SAN
JUANS AND ADJACENT SOUTHERN VALLEYS WHERE SCATTERED SNOW SHOWERS
CONTINUE. ACCUMULATIONS WILL BE ON THE LIGHT SIDE...BUT WEBCAMS
INDICATING SOME IMPACT ON ROAD SURFACES. LATEST RUC SUGGESTS THIS
ACTIVITY WILL CONTINUE FOR A FEW MORE HOURS IN SHALLOW UPSLOPE
FLOW INTO THE SAN JUANS.
&&
.PREV DISCUSSION /ISSUED 415 AM MST SUN FEB 5 2012/...
SHORT TERM /TODAY THROUGH MONDAY NIGHT/...
CUT-OFF UPPER LOW WAS FORMING OVER WRN UT EARLY THIS MORNING IN AN
ELONGATED AREA OF LOW PRESSURE THAT STRETCHED FROM NV TO KS. THIS
UPPER LOW WILL STAY OVER UT THROUGH TONIGHT...WHEN A SHORTWAVE
DROPPING OUT OF CENTRAL CANADA AND A PACIFIC TROUGH REACHING THE
COAST FINALLY BEGIN TO PULL/PUSH IT EASTWARD ACROSS COLORADO ON
MONDAY-MONDAY NIGHT. THIS WILL KEEP AREAS OF CLOUDS AND A CHANCE OF
SNOW SHOWERS PRESENT THROUGH MONDAY NIGHT...AND MODELS ARE IN GOOD
AGREEMENT ON THIS SCENARIO. EMBEDDED DISTURBANCES ROTATING
COUNTERCLOCKWISE AROUND THE LOW WILL CROSS SE UT/SW CO AND FOCUS THE
CHANCE OF PRECIP MOSTLY ACROSS THE SOUTH HALF OF OUR FORECAST AREA.
THE BEST CHANCE LOOKS TO BE SUNDAY NIGHT AND MONDAY WHEN PERHAPS THE
MOST ENERGETIC DISTURBANCE PASSES. MOISTURE SHOULD BE LIMITED AS
THERE IS NO MOISTURE TAP TO THIS SYSTEM...BUT TEMPERATURES ALOFT
WILL BE NEAR OR IN THE FAVORABLE REGIME FOR SNOW CRYSTAL
GROWTH...AND SNOW SHOWERS COULD PRODUCE LOCALIZED ACCUMULATIONS OF A
COUPLE INCHES OVER THE SOUTHERN AND CENTRAL MOUNTAINS. SNOW CHANCES
WILL BE ON THE DECREASE MONDAY NIGHT AS THE LOW MOVES BY.
TEMPERATURES LOOK TO RUN NEAR PERSISTENCE TO A FEW DEGREES COOLER.
LONG TERM /TUESDAY THROUGH SATURDAY/...
GOOD AGREEMENT BETWEEN THE MEDIUM RANGE MODELS THROUGH THE ENTIRE
LONG TERM PERIOD. STRONG PACIFIC WAVE BREAKS OFF FROM THE MAIN
WESTERLIES AND DIVES SOUTHEAST ALONG THE CALIFORNIA AND BAJA
COAST ON WEDNESDAY AND THURSDAY...MISSING OUR FORECAST AREA ALTHOUGH
SOUTHEAST UTAH MAY SEE AN INCREASE OF CLOUDS. BUT THERE ARE SOME
SUBTLE DIFFERENCES THAT DOES HAVE SMALL IMPLICATIONS FOR OUR FORECAST
AREA. THE GFS SHOWS SOME SPOTTY LIGHT PCPN WITH A WEAK SHORT WAVE
BRUSHING NW COLORADO ON WEDNESDAY AFTERNOON AND EVENING. THE
LATEST ECMWF SHOW A SIMILAR SOLUTION BUT THE SPOTTY PCPN OCCURS THE
NEXT DAY. THE CANADIAN MODEL SHOWS STRONGER PACIFIC ENERGY
UNDERCUTTING THE STRONG AMPLIFIED RIDGE OVER WRN CANADA. NONE OF
THESE SOLUTIONS CAN BE CONSIDERED A SIGNIFICANT EVENT...BUT
SUGGEST THAT THE UPCOMING WEEK MAY NOT BE COMPLETELY DRY. RUN TO RUN
MODEL CONSISTENCY CAN BE BETTER AND BELIEVE THAT FUTURE MODEL
SOLUTIONS WILL OFFER MORE DIFFERENCES. EXTENDED GUIDANCE POPS
STAY BELOW 15 PERCENT AND WILL NOT DEVIATE FROM THIS AT THIS
TIME...ESSENTIALLY KEEPING THE GOING FORECAST DRY THROUGH DAYS 3
THROUGH 7. CONFIDENCE IS SO-SO AND IF MODELS SHOW SOME CONSISTENCY
WITH THE PASSING SHORT WAVE WEDNESDAY NIGHT AND THURSDAY TIME
FRAME...THEN CHANCE POPS FOR NW COLORADO WILL NEED TO BE
INTRODUCED.
&&
.AVIATION /FOR 12Z TAF ISSUANCE/...
SNOW SHOWERS WILL INCREASE OVER THE MOUNTAINS THIS AFTERNOON AND
WILL RESULT IN AREAS OF MOUNTAIN OBSCURATION...ESPECIALLY OVER THE
SAN JUAN MOUNTAINS. THE CHANCES FOR LESS THAN VFR CONDITIONS AT
AREA MOUNTAIN AIRPORTS WILL RANGE FROM 30 TO 40 PERCENT FOR KASE
AND KEGE.
KDRO AND KPSO...SCATTERED SNOW SHOWERS WITH A 40 TO 50 PERCENT
CHANCE THAT MVFR CIGS AND VIS WILL OCCUR TODAY AND TONIGHT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE.......JDC
SHORT TERM...JAD
LONG TERM....PF
AVIATION.....TGJT
PREVIOUS FORECAST DISCUSSION IS BELOW...
AS OF 300 PM EST...SUNNY SKIES AND MILD TEMPS PREVAILED ACROSS
THE FA WITH TEMPS RANGING FROM AROUND 40 NORTHWEST TO THE LOWER
50S SOUTHEAST.
FOR TONIGHT AND TUESDAY...EXPECT A COLD FRONT TO DROP SOUTHEAST FROM THE
SAINT LAWRENCE VALLEY THIS EVENING THROUGH OUR REGION LATE TONIGHT
INTO TUESDAY MORNING AND BE LOCATED ACROSS FAR SOUTHEAST NEW YORK
AND THE SOUTHERN NEW ENGLAND COAST EARLY TUESDAY AFTERNOON. THERE
IS VERY LITTLE MOISTURE ASSOCIATED WITH THIS SYSTEM AND OTHER THAN
AN INCREASE IN CLOUDS IN MOST AREAS HAVE LIMITED WIDELY SCATTERED
TO SCATTERED SNOW SHOWERS TO THE NORTHWEST THIRD OF THE FA. SNOW
AMOUNTS SHOULD BE VERY LIGHT WITH GENERALLY A HALF INCH OR LESS
MAINLY ACROSS THE WESTERN ADIRONDACKS WITH ISOLATED AMOUNTS UP TO
AN INCH. WINDS ARE EXPECTED TO REMAIN SOUTHWEST AHEAD OF THE FRONT
AND THEN SHIFT TO W-NW BEHIND THE FRONT AS COLDER AIR FUNNELS INTO
OUR REGION. EXPECT LOWS TONIGHT TO GENERALLY BE IN THE 20S TO
AROUND 30. HIGHS ON TUESDAY ARE EXPECTED TO RANGE FROM THE MID 20S
NORTHWEST TO MID 40S SOUTHEAST.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
FOR TUESDAY NIGHT THROUGH THURSDAY EXPECT HIGH PRESSURE TO BE THE
DOMINANT FEATURE AS THE FIRST HIGH PRESSURE CENTER CRESTS ACROSS
OUR REGION TUESDAY NIGHT AND THEN WEAKENS AS THE NOSE OF OF A
LARGE RIDGE OF HIGH PRESSURE OVER THE MID MISSISSIPPI VALLEY
EXTENDS INTO OUR REGION WEDNESDAY NIGHT INTO THURSDAY. THERE WILL
BE A FAST MOVING LOW PRESSURE SYSTEM PASSING SOUTH OF OUR AREA
ACROSS THE CENTRAL APPALACHIANS ON WEDNESDAY...HOWEVER THIS SYSTEM
APPEARS TOO FAR SOUTH FOR MOST OF AREA TO SEE ANY PCPN. HAVE
PLACED SLIGHT CHANCE TO LOW CHANCE POPS FOR SNOW IN THE FORECAST
ACROSS EXTREME SOUTHERN PORTION OF FA WEDNESDAY AFTERNOON INTO
WEDNESDAY EVENING. THIS AREA IS GENERALLY FROM SOUTH OF ELLENVILLE
TO POUGHKEEPSIE TO SOUTH OF TORRINGTON. EXPECT TEMPS TO BE MORE
SEASONABLE DURING THIS PERIOD. EXPECT LOWS TUESDAY NIGHT TO RANGE
FROM 5 BELOW ZERO NORTHWEST TO THE UPPER TEENS TO AROUND 20
SOUTHEAST. HIGH ON WEDNESDAY ARE EXPECTED TO BE RANGE FROM THE MID
20S NORTHWEST TO UPPER 30S SOUTHEAST. LOWS WEDNESDAY NIGHT ARE
EXPECTED TO BE IN THE UPPER SINGLE DIGITS AND LOWER TEENS
NORTHWEST TO LOWER 20S SOUTHEAST WITH HIGHS ON THURSDAY GENERALLY
IN THE 30S...EXCEPT LOWER 40S SOUTHEAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE EXTENDED PERIOD WILL BEGIN WITH AN ARCTIC FRONT APPROACHING THE
REGION. THE MODELS ARE STILL HAVING TROUBLE WITH THE EXACT TIMING OF
THIS BOUNDARY. FOR NOW...IT LOOKS LIKE OUR REGION WILL REMAIN AHEAD
OF THE BOUNDARY FOR THURSDAY NIGHT...SO MIN TEMPS WON/T BE TOO
COLD...AS A S-SW FLOW AHEAD OF THE BOUNDARY WILL KEEP MIN TEMPS IN
THE 20S FOR MOST VALLEY AREAS...WITH TEENS FOR THE HIGHER
TERRAIN...WHICH IS ABOVE NORMAL FOR THIS TIME OF YEAR.
BY FRIDAY...THE BOUNDARY WILL BEGIN TO APPROACH FROM THE NORTH. THIS
COLD FRONT WILL BE QUITE MOISTURE STARVED...SO WILL KEEP CHC POPS
ONLY TO HIGH TERRAIN OF NORTHERN AREAS. FURTHER SOUTH...SLIGHT CHC
POPS EXTEND DOWN AS FAR AS THE CAPITAL REGION. DAYTIME TEMPS SHOULD
GO ABOVE FREEZING FOR THE VALLEY AREAS...SO HAVE GONE WITH RAIN/SNOW
DEPENDING ON SFC TEMPS. PRECIP WILL BE PRETTY SPOTTY...AND MOST
AREAS OUTSIDE THE HIGH TERRAIN LOOK TO STAY DRY.
THE MODELS CONTINUE TO DISAGREE ON HOW QUICKLY THE FRONT PUSHES
SOUTH THROUGH THE AREA. THE 12 UTC ECMWF SUGGESTS THAT A WAVE
DEVELOPS ALONG THE BOUNDARY FOR FRIDAY NIGHT INTO SATURDAY...WHICH
COULD BRING SOME LIGHT SNOW TO THE AREA /QPF IS GENERALLY A TENTH OF
AN INCH OR LESS/...AS THE FRONT DROPS THROUGH OUR AREA.
MEANWHILE...THE 12 UTC GFS BRINGS THE FRONT THROUGH BY SATURDAY
MORNING...AND ALSO SHOWS A WEAK WAVE DEVELOPING ALONG THE
BOUNDARY...BUT AFTER IT CROSSES OUR AREA. THIS WAVE COULD BRING SOME
LIGHT SNOW TO MAINLY SOUTHERLY PARTS OF THE AREA BY SAT NIGHT INTO
SUNDAY. SIMILAR TO THE ECMWF...THE GFS SHOWS VERY LIGHT QPF ACROSS
OUR AREA.
FOR NOW WITH THE UNCERTAINTY REGARDING THE MODELS...HAVE GONE WITH
SLIGHT CHC/LOW CHC POPS THROUGH MUCH OF THE WEEKEND...WITH TEMPS
BELOW NORMAL. VALLEY MAX TEMPS LOOK TO BE IN THE 20S...WITH SINGLE
DIGITS TO LOW TEENS AT NIGHT. THE HIGHER TERRAIN WILL BE EVEN
COLDER...WITH TEENS TO NEAR 20 DURING THE DAY...AND MIN TEMPS NEAR
ZERO AT NIGHT. IT COULD EVEN BE COLDER...AS THE 12 UTC ECMWF SHOWS
THE POLAR VORTEX DROPPING TOWARDS THE REGION...AND ALLOWING 850 HPA
TEMPS OF -20 TO -25 DEGREES ACROSS THE AREA BY LATE IN THE WEEKEND.
AT THIS POINT...WE WON/T GO WITH THIS SCENARIO QUITE YET...BUT THE
POTENTIAL FOR A FEW VERY COLD DAYS BY LATE IN THE WEEKEND/EARLY NEXT
WEEK IS POSSIBLE. ALSO...THE MODELS CONTINUE TO SHOW PRECIP BELOW
NORMAL...AS MOISTURE WILL BE QUITE LIMITED ACROSS THE AREA.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
CLEAR SKIES WILL BE IN PLACE FOR MOST OF THE EVENING HOURS. AS A
FRONTAL BOUNDARY APPROACHES FROM THE NORTH LATE TONIGHT INTO
TUESDAY MORNING...STRAOCU CLOUDS WILL INCREASE FROM NORTH TO
SOUTH ACROSS THE REGION. THE CLOUDS WILL REACH KGFL AFTER
06Z...KALB BY 08Z...AND KPOU BY 12Z. FLYING CONDITIONS WILL
GENERALLY REMAIN VFR...ALTHOUGH A BRIEF PERIOD OF MVFR CIGS FOR
KGFL IS POSSIBLE ON TUESDAY MORNING. KALB/KPOU SHOULD STAY VFR
WITH NO PRECIP EXPECTED AT ALL TERMINALS. CLOUDS WILL START TO
SCT OUT BY MID TO LATE AFTN ON TUESDAY AS THE FRONT DRIFTS SOUTH
OF THE REGION AND HIGH PRESSURE NOSES IN FROM THE NORTH.
WINDS WILL BE LIGHT TO CALM TONIGHT BEFORE BECOMING NORTHERLY BY
TUESDAY MORNING. WINDS WILL GENERALLY BE LESS THAN 10 KTS.
OUTLOOK...
TUE NGT-SAT...MAINLY VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE NEXT 5 DAYS. ANY PCPN
WILL BE IN THE FORM OF LIGHT SNOW SHOWERS NORTHWEST LATER TONIGHT
INTO TUESDAY MORNING AND ACROSS FAR SOUTHERN PORTION OF THE FA
WEDNESDAY AFTERNOON INTO WEDNESDAY EVENING. REMAINDER OF FA IS
EXPECTED TO BE DRY. SOME GAGES ARE STILL BEING IMPACTED BY ICE
ACROSS NORTHERN PORTIONS OF THE HSA.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...FRUGIS/11/WASULA
SHORT TERM...11
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS MIAMI FL
1239 AM EST SUN FEB 5 2012
.AVIATION...THRU 06Z MON.
PLENTY OF CLOUD COVERAGE WITH ISOLATED TO SCATTERED SHOWERS
DEVELOPING AND SPREADING NORTHWEST OVER SOUTH FLORIDA CONTINUES
TO BE SUPPORTED IN THE LATEST MODEL GUIDANCE THROUGH THE EXTENT OF
THIS FORECAST CYCLE. SUB VFR CONDITIONS FOR BRIEF PERIODS WILL
CERTAINLY REMAIN A POSSIBILITY DUE TO REDUCED CIGS/VSBYS IN AND
AROUND THESE DEVELOPING SHOWERS. THE LOW-LEVEL FLOW WILL REMAIN
OUT OF THE SOUTHEAST AS A WEAK AREA OF LOW PRESSURE EVOLVES
ACROSS THE SOUTH- CENTRAL GULF OF MEXICO TODAY. 85/AG
&&
.PREV DISCUSSION... /ISSUED 836 PM EST SAT FEB 4 2012/
UPDATE...
NO CHANGES TO THE EXISTING FORECAST AT THIS TIME ...
SHOWERS CONTINUE TO AFFECT THE COASTAL WATERS OF THE EAST COAST, MAINLY
SECTIONS OF BROWARD AND PALM BEACH COUNTIES THIS EVENING. ISOLATED
TO SCATTERED SHOWERS WILL CONTINUE TONIGHT DUE TO THE MODERATE
EASTERLY FLOW AND SUFFICIENT MOISTURE DEPTH. WARM TEMPERATURES CAN
BE EXPECTED AGAIN TONIGHT WITH LOWS IN THE 60S TO AROUND 70.
THE RUC RAPID REFRESH MODEL FOR TONIGHT GENERATES CONVECTIVE
ACTIVITY OVER THE GULF OF MEXICO OUTSIDE OF THE GULF COASTAL
WATERS. HOWEVER, IT HINTS AT INCREASED SHOWER ACTIVITY TOWARD THE
EARLY MORNING HOURS OVER MIAMI-DADE AND BROWARD. THE SPC MESOSCALE
ANALYSIS SHOWS MOISTURE CONVERGENCE AND AN INCREASE IN THETA AND
MIXING RATION BETWEEN BROWARD AND PALM BEACH COUNTIES FOR THE PAST HOUR,
WHICH COINCIDES WITH THE AREA OF SHOWER ACTIVITY OBSERVED AT THE
PRESENT TIME.
THE FORECAST REASONING REMAINS UNCHANGED. AN UPPER LEVEL
TROUGH THAT EXTENDS FROM THE YUCATAN INTO THE CENTRAL/EASTERN
GULF WILL MOVE TOWARDS SOUTH FLORIDA/FLORIDA STRAITS ON SUNDAY
INTO MONDAY...WITH PWATS SLOWLY INCREASING THROUGH THIS TIME. THE
PRECIP AMOUNTS ARE STILL EXPECTED TO BE ON THE LIGHT TO MODERATE
SIDE...WITH RAINFALL TOTALS OF 1/4 TO 1/2 AN INCH FOR THE NAPLES
AND WEST OF LAKE OKEECHOBEE...AND 1/2 TO 1.5 INCHES FOR THE EAST
COAST METRO REGIONS.
PREV DISCUSSION... /ISSUED 704 PM EST SAT FEB 4 2012/
AVIATION...LITTLE CHANGE IN THE EXPECTED CONDITIONS OVER THE NEXT
12 HOURS WITH CONTINUED EASTERLY FLOW AND ISOLATED TO SCATTERED
SHOWER ACTIVITY. CEILINGS WILL BECOME A BIT LOWER OVERNIGHT WITH
BRIEF MVFR CONDITIONS POSSIBLE, EXCEPT AT KPBI, WHERE THEY WILL
BE MORE PREVALENT. WINDS WILL BECOME SOUTHEAST AT 10-13 KNOTS BY
SUNDAY MORNING WITH SHOWER ACTIVITY SLOWLY BECOMING MORE NUMEROUS
THROUGHOUT THE DAY. A FEW TSRA COULD FORM BY SUNDAY AFTERNOON,
BUT WILL ONLY MENTION VCSH AT THIS TIME.
PREV DISCUSSION... /ISSUED 303 PM EST SAT FEB 4 2012/
DISCUSSION...
SURFACE HIGH PRESSURE IS MOVING EAST INTO THE ATLANTIC AS LOW
PRESSURE MOVES INTO THE TENNESSEE VALLEY. THIS WILL ALLOW THE
PRESSURE GRADIENT TO SLOWLY RELAX TONIGHT AND SUNDAY...WITH WINDS
VEERING TO THE SOUTHEAST. ISOLATED TO SCATTERED SHOWERS WILL
CONTINUE TONIGHT DUE TO THE MODERATE EASTERLY FLOW AND SUFFICIENT
MOISTURE DEPTH. WARM TEMPERATURES CAN BE EXPECTED AGAIN TONIGHT
WITH LOWS IN THE 60S TO AROUND 70. MOSTLY CLOUDY SKIES CAN BE
EXPECTED TONIGHT THROUGH THE BEGINNING OF NEXT WEEK DUE TO UPPER
LEVEL CLOUDINESS FROM A LOW LEVEL TROUGH THAT EXTENDS FROM THE
YUCATAN INTO THE CENTRAL/EASTERN GULF. THIS FEATURE WILL MOVE
TOWARDS SOUTH FLORIDA/FLORIDA STRAITS ON SUNDAY INTO MONDAY...WITH
PWATS SLOWLY INCREASING THROUGH THIS TIME. MODEL SOLUTIONS DIFFER
ON HOW FAST AND HOW FAR NORTH THE LOW/MID LEVEL MOISTURE WILL MOVE
INTO THE REGION. THE GFS HAS THE MOISTURE FURTHER NORTH THAN THE
ECMWF ON THE 12Z RUNS...BRINGING THE MOISTURE IN MOST OF THE
REGION LATE SUNDAY AFTERNOON THROUGH MONDAY MORNING. THE ECMWF
ONLY BRINGS IN THE DEEPEST MOISTURE TO THE SOUTHERN PORTION OF THE
REGION. THIS DIFFERS FROM THE 00Z RUN...AND THE 00Z SOLUTION WAS
MORE SIMILAR TO THE GFS. HOWEVER...IT APPEARS THAT MUCH NEEDED
RAINFALL WILL BE MOVING INTO THE REGION LATE SUNDAY THROUGH
MONDAY.
THE RIGHT ENTRANCE REGION OF A WEAK UPPER JET WILL BE OVER THE
REGION SUNDAY AFTERNOON INTO THE SUNDAY EVENING AND THIS WILL
ENHANCE LIFT AT THE SAME TIME MOISTURE IS INCREASING OVER THE
REGION. SO KEPT CHANCE POPS SUNDAY FOR MOST OF SOUTH FLORIDA.
BUMPED UP POPS TO HIGH END CHANCE TO LIKELY FOR THE SOUTHERN AND
SOUTHEAST PORTIONS OF THE CWA FOR SUNDAY NIGHT. ALSO KEPT MENTION
OF THUNDER FOR THE SOUTHERN HALF OF THE REGION FOR SUNDAY
AFTERNOON AND SUNDAY NIGHT. THE DEEPER MOISTURE MAY BE MOVING OUT
OF THE REGION MONDAY MORNING...BUT A WEAK FRONTAL BOUNDARY IS
EXPECTED TO MOVE TOWARDS SOUTH FLORIDA. THE LOW LEVEL TROUGH MAY
ALSO STAY OVER THE REGION THROUGH MONDAY AFTERNOON. SO BUMPED UP
POPS TO CHANCE TO LIKELY ACROSS THE REGION ON MONDAY. ATTM...IT
APPEARS THE PRECIP AMOUNTS MAY BE ON THE LIGHT TO MODERATE
SIDE...WITH RAINFALL TOTALS OF 1/4 TO 1/2 AN INCH FOR THE NAPLES
AND WEST OF LAKE OKEECHOBEE...AND 1/2 TO 1.5 INCHES FOR THE EAST
COAST METRO REGIONS. WENT BELOW GUIDANCE FOR HIGH TEMPERATURES ON
MONDAY BY A COUPLE DEGREES DUE TO EXPECTED CLOUD COVER AND
RAINFALL.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 79 67 77 67 / 30 50 50 20
FORT LAUDERDALE 79 67 79 69 / 40 60 60 20
MIAMI 80 67 79 69 / 40 60 60 20
NAPLES 80 65 79 64 / 30 30 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...60/BD
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS LINCOLN IL
230 PM CST SUN FEB 5 2012
.DISCUSSION...
ISSUED 230 PM CST SUN FEB 5 2012
HIGH PRESSURE CONTINUES TO BUILD INTO CENTRAL AND SOUTHEAST
ILLINOIS THIS AFTERNOON...AND IS HELPING TO PROVIDE A MOSTLY SUNNY
AND SEASONABLY MILD DAY. RELATIVELY QUIET WEATHER IS ANTICIPATED
THIS WEEK OVERALL...WITH TEMPERATURES THE MAIN FORECAST CONCERN
FOR MOST OF THE WEEK. HOWEVER...IN THE NEXT 12-24 HOURS...WE ARE
ALSO CONCERNED WITH HOW MUCH STRATUS/FOG FROM THE UPPER MIDWEST
WILL SPREAD INTO AND/OR INCREASE OVER THE FORECAST AREA.
12Z MODELS IN GOOD OVERALL AGREEMENT FOR THE NEXT FEW DAYS WITH
THE MAIN FEATURES EXPECTED TO IMPACT THE FORECAST AREA. HOWEVER...
ONLY A FEW MESOSCALE MODELS HAVE A CLUE THAT THE UPSTREAM
STRATUS/FOG EVEN EXISTS. HAVE LARGELY DISCOUNTED ANY MODEL
SOLUTION REGARDING THIS STRATUS/FOG...AND USED
EXTRAPOLATION/CONCEPTUAL MODELS TO TRY AND PIN POINT HOW THEY WILL
IMPACT THE AREA. IN THE LONGER RANGE OF THE FORECAST...
MODEL/ENSEMBLE SPREAD IS STILL PRETTY LARGE WITH HOW THE VORTEX
OVER EASTERN CANADA WILL DEVELOP DURING THE WEEK...AND HOW MUCH
COLD AIR ASSOCIATED WITH THIS VORTEX WILL DIP INTO THE MIDWEST.
SHORT TERM...TONIGHT THROUGH WEDNESDAY...A NEAR SURFACE...ROUGHLY
1000 FOOT THICK STRATUS DECK HAS BEEN OVER THE UPPER MIDWEST THE
PAST COUPLE OF DAYS. IT IS TRAPPED BENEATH A SUBSIDENCE INVERSION
AND IS LIKELY AIDED BY A LITTLE BIT OF SNOW COVER IN THE AREA.
THIS DECK HAS BEEN SINKING SOUTH TODAY WITH THE SURFACE/BOUNDARY
LAYER FLOW AND HAS NOT DIMINISHED TO ANY LARGE DEGREE...AT LEAST
TO THE SOUTH/EAST OF THE SURFACE RIDGE. THE SURFACE RIDGE WILL
SLOWLY SINK SOUTHEAST ACROSS THE FORECAST AREA TONIGHT AND IT
APPEARS LIKELY TO BRING THE STRATUS/FOG WITH IT. THE LOSS OF
DIURNAL HEATING IN A FEW HOURS IS ALSO APT TO LET THE EDGES OF
THE CLOUD DECK SPREAD OUT LARGER THAN ITS CURRENT AREAL EXTENT.
WHILE THE CLOUDS/FOG ARE LIKELY TO ONLY IMPACT WESTERN SECTIONS OF
THE FORECAST AREA THIS EVENING...IT SHOULD SPREAD EAST OVERNIGHT
AS SURFACE/BOUNDARY LAYER FLOW STARTS TURNING WESTERLY ON THE BACK
SIDE OF THE SURFACE RIDGE.
EXPECT CLOUDS/FOG TO BREAK UP MONDAY AFTERNOON ON THE BACK SIDE OF
THE RIDGE...MUCH AS IS OCCURRING ACROSS MINNESOTA AND THE EASTERN
DAKOTAS TODAY. HOWEVER...THIS CLEARING IS NOT LIKELY TO OCCUR SOON
ENOUGH TO ALLOW TEMPERATURES TO REACH MOST GUIDANCE HIGH
TEMPERATURES. WITH THIS IN MIND...HAVE CUT HIGH TEMPS A CATEGORY
MONDAY. SKIES WILL NOT BE CLEAR VERY LONG AS AN APPROACHING SYSTEM
BRINGS ADDITIONAL CLOUD COVER SPILLING IN FROM THE NORTHWEST
MONDAY NIGHT.
A NORTHERN STREAM SHORT WAVE WILL DIVE THROUGH THE AREA TUESDAY...
BRINGING A MOISTURE STARVED COLD FRONT WITH IT. THIS WAVE WILL
ALSO PICK UP AN ORPHANED UPPER LOW SPINNING OVER THE ROCKIES...
WHICH WILL TRACK EAST ALONG THE FRONT INTO WEDNESDAY. THE LACK OF
MOISTURE SHOULD KEEP RAIN/SNOW CHANCES TO A MINIMUM TUESDAY INTO
WEDNESDAY...WITH THE BEST CHANCES OCCURRING ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA ALONG THE TRACK OF THE ROCKIES WAVE.
TEMPERATURES WILL ALSO BE NOTICEABLY COOLER ON WEDNESDAY BEHIND THE
FRONT.
LONG TERM...THURSDAY THROUGH SUNDAY...COLD AIR IS FORECAST TO LOAD
UP OVER EASTERN CANADA DURING THE PERIOD...AND MOST MODELS HAVE AN
ARCTIC FRONT PUSHING THROUGH THE FORECAST AREA IN THE VICINITY OF
FRIDAY. THIS FRONT WILL ALSO BE MOISTURE STARVED AND SHOULD COME
THROUGH DRY. THERE ARE A WIDE RANGE OF SOLUTIONS WITH RESPECT TO
HOW MUCH COLD AIR WILL SETTLE IN BEHIND THE FRONT. WILL MAINTAIN
TEMPERATURES AT OR BELOW NORMAL FOR THE WEEKEND...BUT THE DETAILS
ARE STILL SUBJECT TO SIGNIFICANT CHANGE.
BAK
&&
.AVIATION...
ISSUED 1153 AM CST SUN FEB 5 2012
ISSUES WITH SPREADING STRATUS FROM THE NORTH AND WEST...AND SMALL
SWATH OF FOG HEADED FOR BMI AND PIA THIS AFTERNOON. MODELS ARE
DOING VERY POORLY WITH THE LLVL RH. HRRR MODEL HAS A BIT MORE
USEFULNESS IN THE SHORT TERM...AND TAFS ARE LEANING HEAVILY ON
THAT SOLUTION. SPREADING THE IFR STRATUS INTO PIA AND BMI AND SPI
LATER THIS AFTERNOON. ISSUE WILL BE THE COLLISION OF THE STRATUS
WITH THE IFR/LIFR VIS AND CIGS FOR BMI AND PIA. BREAKING SPI AND
DEC OUT OF THE CLOUDS IN THE MORNING...BUT CONFIDENCE IS LOW FOR
ANY AND ALL SOLUTIONS. TREND ANALYSIS WOULD KEEP IFR IN PIA BMI
AND CMI THROUGH THE OVERNIGHT...BUT POTENTIAL FOR THOSE SAME
CLOUDS TO CREEP TO SRN TERMINALS IS VERY POSSIBLE.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1202 PM CST SUN FEB 5 2012
.DISCUSSION...
ISSUED 1039 AM CST SUN FEB 5 2012
FORECAST IS DOING JUST FINE OVERALL...BUT NEED TO WATCH A SMALL
SWATH OF FOG APPROACHING FROM THE NORTH...THAT IS ERODING AS IT
MOVES INTO THE CWA...SIMILAR TO THE FOG OVER CMI/DNV AREA THAT IS
FINALLY BURNING OFF. WILL UPDATE THE ZONES TO ELIMINATE MORNING
WORDING...AND PUT SOME PATCHY FOG IN FOR THE BMI TO PIA CORRIDOR
ALONG INTERSTATE 74 FOR THE NEXT COUPLE HOURS. ANOTHER ISSUE WILL
BE SOME LLVL STRATUS TO THE NORTH AND WEST THAT IS INCORRECTLY
REPRESENTED IN ALL THE MODELS. HOWEVER...DVN AND ILX SOUNDINGS
HAVE ENOUGH DRY AIR FROM 900 TO 700 MB TO ERODE SOME OF THAT AS
WELL. MAY BE A DAY OF MULTIPLE UPDATES OVERALL.
&&
.AVIATION...
ISSUED 1153 AM CST SUN FEB 5 2012
ISSUES WITH SPREADING STRATUS FROM THE NORTH AND WEST...AND SMALL
SWATH OF FOG HEADED FOR BMI AND PIA THIS AFTERNOON. MODELS ARE
DOING VERY POORLY WITH THE LLVL RH. HRRR MODEL HAS A BIT MORE
USEFULNESS IN THE SHORT TERM...AND TAFS ARE LEANING HEAVILY ON
THAT SOLUTION. SPREADING THE IFR STRATUS INTO PIA AND BMI AND SPI
LATER THIS AFTERNOON. ISSUE WILL BE THE COLLISION OF THE STRATUS
WITH THE IFR/LIFR VIS AND CIGS FOR BMI AND PIA. BREAKING SPI AND
DEC OUT OF THE CLOUDS IN THE MORNING...BUT CONFIDENCE IS LOW FOR
ANY AND ALL SOLUTIONS. TREND ANALYSIS WOULD KEEP IFR IN PIA BMI
AND CMI THROUGH THE OVERNIGHT...BUT POTENTIAL FOR THOSE SAME
CLOUDS TO CREEP TO SRN TERMINALS IS VERY POSSIBLE.
HJS
&&
.PREV DISCUSSION...
ISSUED 240 AM CST SUN FEB 5 2012
UPPER LOW CONTINUES TO SPIN ACROSS THE CENTRAL U.S. EARLY THIS
MORNING...WITH WATER VAPOR IMAGERY SHOWING IT CENTERED NEAR KANSAS
CITY...WITH A SECOND LOW FURTHER WEST ACROSS UTAH. CLEARING LINE
HAS BEEN QUICKLY MOVING SOUTH ACROSS THE NORTHERN CWA THE LAST FEW
HOURS...AND WAS JUST SOUTH OF THE I-74 CORRIDOR AT 2 AM. INITIAL
FORECAST CHALLENGE WILL BE WITH CLEARING TREND AND FOG POTENTIAL
EARLY ON...AS CLOUDS BREAK IN AREAS THAT HAD DECENT RAINFALL THE
LAST 24-36 HOURS. HOWEVER...THE PRIMARY FORECAST ISSUE WILL BE
WITH TREND FOR COLD WEATHER TOWARD THE END OF THE WEEK.
SHORT TERM...TODAY THROUGH TUESDAY...
LATEST HRRR NOT TOO FAR OFF WITH CURRENT POSITIONING OF THE
STRATUS...AND SHOWS MUCH OF THE CWA SHOULD BE STRATUS-FREE BY LATE
MORNING. NORTHERN CWA IS MOST VULNERABLE FOR SOME FOG EARLY...WITH
LACON CURRENTLY REPORTING 3/4 MILE AND BLOOMINGTON 1-3/4 MILE AS
THE CLOUDS HAVE BROKEN. SO FAR NOTHING NORTH OF THERE IS GETTING
OUT OF HAND YET DESPITE A LONGER CLEAR PERIOD...SO WILL MAKE A
LAST MINUTE DECISION ON WHETHER TO CONTINUE FOG POTENTIAL BEYOND
SUNRISE.
MISSOURI UPPER LOW PROGGED TO DRIFT SOUTHEAST TO THE LOWER OHIO
VALLEY BY TONIGHT. ANY RESIDUAL LIGHT RAIN/DRIZZLE WILL CONTINUE
TO SHRINK WITH THIS LOW...AND WILL LIKELY ONLY MENTION IT IN THE
FAR SOUTHEAST FOR EARLY TODAY. SURFACE HIGH PRESSURE RIDGING
EASTWARD POSES ANOTHER CONCERN FOR LOW CLOUDS/FOG TONIGHT. LATEST
SREF GRAPHICS SHOWING THE NORTHWEST CWA BEING OVERSPREAD BY LOWER
STRATOCUMULUS AFTER MIDNIGHT...LASTING UNTIL ABOUT MID-MORNING
MONDAY. GIVEN THAT THIS AREA SHOULD SEE DECENT SUNSHINE MUCH OF
TODAY TO HELP DRY THINGS OUT...AM NOT OVERLY CONFIDENT IN THIS
CLOUD SCENARIO AT THE MOMENT. FOR NOW...WILL GO WITH PARTLY CLOUDY
CONDITIONS ACROSS THE NORTHWEST TONIGHT AND MAINLY CLEAR
ELSEWHERE...WITH THE DAY SHIFT MAKING ANY FURTHER ADJUSTMENTS AS
THE DAYTIME TRENDS PLAY OUT.
LEFTOVER CUTOFF ENERGY OVER THE CENTRAL ROCKIES SHOULD WEAKEN AND
GET PICKED UP BY A TROUGH MOVING ALONG THE CANADIAN BORDER MONDAY
NIGHT AND TUESDAY. NOT A LOT OF MOISTURE AVAILABLE OVERHEAD WHEN
IT ARRIVES...BUT SOME RESIDUAL MOISTURE ACCOMPANYING THE LEFTOVER
ENERGY IS ENOUGH TO WARRANT SLIGHT CHANCE POPS FOR TUESDAY AND
TUESDAY NIGHT.
LONG TERM...WEDNESDAY THROUGH SATURDAY...
QUIET WEATHER EXPECTED MIDWEEK AS HIGH PRESSURE DRIFTS ACROSS THE
MIDWEST. MAIN CONCERN REMAINS WITH THE AMOUNT OF ARCTIC AIR THAT
WILL BE DROPPING SOUTHEASTWARD LATE IN THE WEEK. GFS BRINGS 850 MB
TEMPERATURES OF -16C ACROSS MOST OF THE CWA BY FRIDAY EVENING...
WHILE ECMWF GIVES US MORE OF A GLANCING BLOW WITH THE CORE OF THE
COLDER AIR CLOSER TO THE GREAT LAKES. HAVE BEGUN TO TREND DOWNWARD
WITH THE TEMPERATURE FORECASTS AS THE MAIN IDEA HAS BEEN
PERSISTENT FOR A COUPLE DAYS NOW...BUT NOT AS AGGRESSIVELY AS THE
GFS WOULD INDICATE...WHICH GIVES THE NORTHERN CWA A STRUGGLE TO
REACH 20 DEGREES ON FRIDAY. THAT MAY BE TOUGH WITHOUT ANY SNOW ON
THE GROUND...BUT WE SHOULD STILL SEE SOMEWHAT OF A COLD SNAP IN
AN OTHERWISE MILD WINTER.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1049 AM CST SUN FEB 5 2012
.DISCUSSION...
ISSUED 1039 AM CST SUN FEB 5 2012
FORECAST IS DOING JUST FINE OVERALL...BUT NEED TO WATCH A SMALL
SWATH OF FOG APPROACHING FROM THE NORTH...THAT IS ERODING AS IT
MOVES INTO THE CWA...SIMILAR TO THE FOG OVER CMI/DNV AREA THAT IS
FINALLY BURNING OFF. WILL UPDATE THE ZONES TO ELIMINATE MORNING
WORDING...AND PUT SOME PATCHY FOG IN FOR THE BMI TO PIA CORRIDOR
ALONG INTERSTATE 74 FOR THE NEXT COUPLE HOURS. ANOTHER ISSUE WILL
BE SOME LLVL STRATUS TO THE NORTH AND WEST THAT IS INCORRECTLY
REPRESENTED IN ALL THE MODELS. HOWEVER...DVN AND ILX SOUNDINGS
HAVE ENOUGH DRY AIR FROM 900 TO 700 MB TO ERODE SOME OF THAT AS
WELL. MAY BE A DAY OF MULTIPLE UPDATES OVERALL.
HJS
&&
.AVIATION...
ISSUED 515 AM CST SUN FEB 5 2012
SEVERAL FORECAST CONCERNS THIS PERIOD WITH THE MAIN SHORT TERM
CONCERN BEING WITH THE FOG POTENTIAL THRU 15Z AND MOVEMENT OF IFR
CIGS JUST SOUTH OF OUR TAF SITES. SECOND CONCERN WILL BE TRACK OF
MVFR/IFR CIGS ACRS NRN IOWA AND OVER PARTS OF NE IL EARLY THIS
MORNING.
BACK-EDGE OF LOWER CLOUDS HAS SHIFTED JUST SOUTH OF SPI AND DEC
AS OF 10Z. EXPECT THE SLOW SOUTH MOVEMENT OF THESE CLOUDS TO
CONTINUE WITH SOME RAGGED MID LEVEL CLOUDS ACRS THE REMAINDER
OF THE FCST AREA. WITH THE RESIDUAL LOW LEVEL MOISTURE IN PLACE
FROM THE RAIN YESTERDAY AND CLEARING SKIES...PATCHY FOG WAS
PREVALENT OVER THE AREA. WILL CONTINUE WITH A TEMPO GROUP FOR
FOG THRU 15Z AND THEN VFR CONDITIONS ARE EXPECTED THRU LATE THIS
AFTERNOON. WITH THE LOW LEVEL MOISTURE IN PLACE AND SUNSHINE
EXPECTED TODAY...WE SHOULD SEE AT LEAST A SCATTERED CU FIELD
DEVELOP DESPITE THE SIGNIFICANT DRYING TAKING PLACE ABOVE 850 MB.
OUR ATTENTION THEN WILL TURN TO THE LOWER CLOUDS TO OUR NORTH AND
NORTHWEST. SHORT RANGE MODELS SUGGEST THE POTENTIAL FOR SOME OF
THE LOWER CIGS TO EDGE INTO WESTERN IL BY MID OR LATE THIS AFTN
AND EARLY THIS EVENING. CONFIDENCE RATHER LOW REGARDING MOVEMENT
OF THE CLOUD DECK LATER THIS AFTN AS LOW LEVEL WIND PROFILES
INDICATE WINDS WILL BACK FROM THE CURRENT NORTHERLY DIRECTION MORE
INTO THE WEST LATE TODAY...WHICH MAY AID IN MORE OF AN EASTWARD
TRAJECTORY TO THE IFR/MVFR CIGS CURRENTLY OVER IOWA. THAT WILL
HAVE TO BE WATCHED IN LATER FORECASTS...BUT FOR NOW WILL HOLD ON
TO THE VFR CONDITIONS THRU LATE THIS AFTN AND THEN INTRODUCE A
SCATTERED CLOUD GROUP AT AROUND 1500 FEET AT PIA LATER TODAY.
SURFACE WINDS WILL CONTINUE FROM A NORTHERLY DIRECTION TODAY AT
AROUND 10 KTS...AND THEN BACK INTO THE NORTHWEST AND THEN WEST
LATE THIS AFTN AND EVENING...WITH SPEEDS AFTR 00Z DROPPING OFF
TO AROUND 5 KTS OR LESS.
SMITH
&&
.PREV DISCUSSION...
ISSUED 240 AM CST SUN FEB 5 2012
UPPER LOW CONTINUES TO SPIN ACROSS THE CENTRAL U.S. EARLY THIS
MORNING...WITH WATER VAPOR IMAGERY SHOWING IT CENTERED NEAR KANSAS
CITY...WITH A SECOND LOW FURTHER WEST ACROSS UTAH. CLEARING LINE
HAS BEEN QUICKLY MOVING SOUTH ACROSS THE NORTHERN CWA THE LAST FEW
HOURS...AND WAS JUST SOUTH OF THE I-74 CORRIDOR AT 2 AM. INITIAL
FORECAST CHALLENGE WILL BE WITH CLEARING TREND AND FOG POTENTIAL
EARLY ON...AS CLOUDS BREAK IN AREAS THAT HAD DECENT RAINFALL THE
LAST 24-36 HOURS. HOWEVER...THE PRIMARY FORECAST ISSUE WILL BE
WITH TREND FOR COLD WEATHER TOWARD THE END OF THE WEEK.
SHORT TERM...TODAY THROUGH TUESDAY...
LATEST HRRR NOT TOO FAR OFF WITH CURRENT POSITIONING OF THE
STRATUS...AND SHOWS MUCH OF THE CWA SHOULD BE STRATUS-FREE BY LATE
MORNING. NORTHERN CWA IS MOST VULNERABLE FOR SOME FOG EARLY...WITH
LACON CURRENTLY REPORTING 3/4 MILE AND BLOOMINGTON 1-3/4 MILE AS
THE CLOUDS HAVE BROKEN. SO FAR NOTHING NORTH OF THERE IS GETTING
OUT OF HAND YET DESPITE A LONGER CLEAR PERIOD...SO WILL MAKE A
LAST MINUTE DECISION ON WHETHER TO CONTINUE FOG POTENTIAL BEYOND
SUNRISE.
MISSOURI UPPER LOW PROGGED TO DRIFT SOUTHEAST TO THE LOWER OHIO
VALLEY BY TONIGHT. ANY RESIDUAL LIGHT RAIN/DRIZZLE WILL CONTINUE
TO SHRINK WITH THIS LOW...AND WILL LIKELY ONLY MENTION IT IN THE
FAR SOUTHEAST FOR EARLY TODAY. SURFACE HIGH PRESSURE RIDGING
EASTWARD POSES ANOTHER CONCERN FOR LOW CLOUDS/FOG TONIGHT. LATEST
SREF GRAPHICS SHOWING THE NORTHWEST CWA BEING OVERSPREAD BY LOWER
STRATOCUMULUS AFTER MIDNIGHT...LASTING UNTIL ABOUT MID-MORNING
MONDAY. GIVEN THAT THIS AREA SHOULD SEE DECENT SUNSHINE MUCH OF
TODAY TO HELP DRY THINGS OUT...AM NOT OVERLY CONFIDENT IN THIS
CLOUD SCENARIO AT THE MOMENT. FOR NOW...WILL GO WITH PARTLY CLOUDY
CONDITIONS ACROSS THE NORTHWEST TONIGHT AND MAINLY CLEAR
ELSEWHERE...WITH THE DAY SHIFT MAKING ANY FURTHER ADJUSTMENTS AS
THE DAYTIME TRENDS PLAY OUT.
LEFTOVER CUTOFF ENERGY OVER THE CENTRAL ROCKIES SHOULD WEAKEN AND
GET PICKED UP BY A TROUGH MOVING ALONG THE CANADIAN BORDER MONDAY
NIGHT AND TUESDAY. NOT A LOT OF MOISTURE AVAILABLE OVERHEAD WHEN
IT ARRIVES...BUT SOME RESIDUAL MOISTURE ACCOMPANYING THE LEFTOVER
ENERGY IS ENOUGH TO WARRANT SLIGHT CHANCE POPS FOR TUESDAY AND
TUESDAY NIGHT.
LONG TERM...WEDNESDAY THROUGH SATURDAY...
QUIET WEATHER EXPECTED MIDWEEK AS HIGH PRESSURE DRIFTS ACROSS THE
MIDWEST. MAIN CONCERN REMAINS WITH THE AMOUNT OF ARCTIC AIR THAT
WILL BE DROPPING SOUTHEASTWARD LATE IN THE WEEK. GFS BRINGS 850 MB
TEMPERATURES OF -16C ACROSS MOST OF THE CWA BY FRIDAY EVENING...
WHILE ECMWF GIVES US MORE OF A GLANCING BLOW WITH THE CORE OF THE
COLDER AIR CLOSER TO THE GREAT LAKES. HAVE BEGUN TO TREND DOWNWARD
WITH THE TEMPERATURE FORECASTS AS THE MAIN IDEA HAS BEEN
PERSISTENT FOR A COUPLE DAYS NOW...BUT NOT AS AGGRESSIVELY AS THE
GFS WOULD INDICATE...WHICH GIVES THE NORTHERN CWA A STRUGGLE TO
REACH 20 DEGREES ON FRIDAY. THAT MAY BE TOUGH WITHOUT ANY SNOW ON
THE GROUND...BUT WE SHOULD STILL SEE SOMEWHAT OF A COLD SNAP IN
AN OTHERWISE MILD WINTER.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
524 AM CST SUN FEB 5 2012
.DISCUSSION...
ISSUED 240 AM CST SUN FEB 5 2012
UPPER LOW CONTINUES TO SPIN ACROSS THE CENTRAL U.S. EARLY THIS
MORNING...WITH WATER VAPOR IMAGERY SHOWING IT CENTERED NEAR KANSAS
CITY...WITH A SECOND LOW FURTHER WEST ACROSS UTAH. CLEARING LINE
HAS BEEN QUICKLY MOVING SOUTH ACROSS THE NORTHERN CWA THE LAST FEW
HOURS...AND WAS JUST SOUTH OF THE I-74 CORRIDOR AT 2 AM. INITIAL
FORECAST CHALLENGE WILL BE WITH CLEARING TREND AND FOG POTENTIAL
EARLY ON...AS CLOUDS BREAK IN AREAS THAT HAD DECENT RAINFALL THE
LAST 24-36 HOURS. HOWEVER...THE PRIMARY FORECAST ISSUE WILL BE
WITH TREND FOR COLD WEATHER TOWARD THE END OF THE WEEK.
SHORT TERM...TODAY THROUGH TUESDAY...
LATEST HRRR NOT TOO FAR OFF WITH CURRENT POSITIONING OF THE
STRATUS...AND SHOWS MUCH OF THE CWA SHOULD BE STRATUS-FREE BY LATE
MORNING. NORTHERN CWA IS MOST VULNERABLE FOR SOME FOG EARLY...WITH
LACON CURRENTLY REPORTING 3/4 MILE AND BLOOMINGTON 1-3/4 MILE AS
THE CLOUDS HAVE BROKEN. SO FAR NOTHING NORTH OF THERE IS GETTING
OUT OF HAND YET DESPITE A LONGER CLEAR PERIOD...SO WILL MAKE A
LAST MINUTE DECISION ON WHETHER TO CONTINUE FOG POTENTIAL BEYOND
SUNRISE.
MISSOURI UPPER LOW PROGGED TO DRIFT SOUTHEAST TO THE LOWER OHIO
VALLEY BY TONIGHT. ANY RESIDUAL LIGHT RAIN/DRIZZLE WILL CONTINUE
TO SHRINK WITH THIS LOW...AND WILL LIKELY ONLY MENTION IT IN THE
FAR SOUTHEAST FOR EARLY TODAY. SURFACE HIGH PRESSURE RIDGING
EASTWARD POSES ANOTHER CONCERN FOR LOW CLOUDS/FOG TONIGHT. LATEST
SREF GRAPHICS SHOWING THE NORTHWEST CWA BEING OVERSPREAD BY LOWER
STRATOCUMULUS AFTER MIDNIGHT...LASTING UNTIL ABOUT MID-MORNING
MONDAY. GIVEN THAT THIS AREA SHOULD SEE DECENT SUNSHINE MUCH OF
TODAY TO HELP DRY THINGS OUT...AM NOT OVERLY CONFIDENT IN THIS
CLOUD SCENARIO AT THE MOMENT. FOR NOW...WILL GO WITH PARTLY CLOUDY
CONDITIONS ACROSS THE NORTHWEST TONIGHT AND MAINLY CLEAR
ELSEWHERE...WITH THE DAY SHIFT MAKING ANY FURTHER ADJUSTMENTS AS
THE DAYTIME TRENDS PLAY OUT.
LEFTOVER CUTOFF ENERGY OVER THE CENTRAL ROCKIES SHOULD WEAKEN AND
GET PICKED UP BY A TROUGH MOVING ALONG THE CANADIAN BORDER MONDAY
NIGHT AND TUESDAY. NOT A LOT OF MOISTURE AVAILABLE OVERHEAD WHEN
IT ARRIVES...BUT SOME RESIDUAL MOISTURE ACCOMPANYING THE LEFTOVER
ENERGY IS ENOUGH TO WARRANT SLIGHT CHANCE POPS FOR TUESDAY AND
TUESDAY NIGHT.
LONG TERM...WEDNESDAY THROUGH SATURDAY...
QUIET WEATHER EXPECTED MIDWEEK AS HIGH PRESSURE DRIFTS ACROSS THE
MIDWEST. MAIN CONCERN REMAINS WITH THE AMOUNT OF ARCTIC AIR THAT
WILL BE DROPPING SOUTHEASTWARD LATE IN THE WEEK. GFS BRINGS 850 MB
TEMPERATURES OF -16C ACROSS MOST OF THE CWA BY FRIDAY EVENING...
WHILE ECMWF GIVES US MORE OF A GLANCING BLOW WITH THE CORE OF THE
COLDER AIR CLOSER TO THE GREAT LAKES. HAVE BEGUN TO TREND DOWNWARD
WITH THE TEMPERATURE FORECASTS AS THE MAIN IDEA HAS BEEN
PERSISTENT FOR A COUPLE DAYS NOW...BUT NOT AS AGGRESSIVELY AS THE
GFS WOULD INDICATE...WHICH GIVES THE NORTHERN CWA A STRUGGLE TO
REACH 20 DEGREES ON FRIDAY. THAT MAY BE TOUGH WITHOUT ANY SNOW ON
THE GROUND...BUT WE SHOULD STILL SEE SOMEWHAT OF A COLD SNAP IN
AN OTHERWISE MILD WINTER.
GEELHART
&&
.AVIATION...
ISSUED 515 AM CST SUN FEB 5 2012
SEVERAL FORECAST CONCERNS THIS PERIOD WITH THE MAIN SHORT TERM
CONCERN BEING WITH THE FOG POTENTIAL THRU 15Z AND MOVEMENT OF IFR
CIGS JUST SOUTH OF OUR TAF SITES. SECOND CONCERN WILL BE TRACK OF
MVFR/IFR CIGS ACRS NRN IOWA AND OVER PARTS OF NE IL EARLY THIS
MORNING.
BACK-EDGE OF LOWER CLOUDS HAS SHIFTED JUST SOUTH OF SPI AND DEC
AS OF 10Z. EXPECT THE SLOW SOUTH MOVEMENT OF THESE CLOUDS TO
CONTINUE WITH SOME RAGGED MID LEVEL CLOUDS ACRS THE REMAINDER
OF THE FCST AREA. WITH THE RESIDUAL LOW LEVEL MOISTURE IN PLACE
FROM THE RAIN YESTERDAY AND CLEARING SKIES...PATCHY FOG WAS
PREVALENT OVER THE AREA. WILL CONTINUE WITH A TEMPO GROUP FOR
FOG THRU 15Z AND THEN VFR CONDITIONS ARE EXPECTED THRU LATE THIS
AFTERNOON. WITH THE LOW LEVEL MOISTURE IN PLACE AND SUNSHINE
EXPECTED TODAY...WE SHOULD SEE AT LEAST A SCATTERED CU FIELD
DEVELOP DESPITE THE SIGNIFICANT DRYING TAKING PLACE ABOVE 850 MB.
OUR ATTENTION THEN WILL TURN TO THE LOWER CLOUDS TO OUR NORTH AND
NORTHWEST. SHORT RANGE MODELS SUGGEST THE POTENTIAL FOR SOME OF
THE LOWER CIGS TO EDGE INTO WESTERN IL BY MID OR LATE THIS AFTN
AND EARLY THIS EVENING. CONFIDENCE RATHER LOW REGARDING MOVEMENT
OF THE CLOUD DECK LATER THIS AFTN AS LOW LEVEL WIND PROFILES
INDICATE WINDS WILL BACK FROM THE CURRENT NORTHERLY DIRECTION MORE
INTO THE WEST LATE TODAY...WHICH MAY AID IN MORE OF AN EASTWARD
TRAJECTORY TO THE IFR/MVFR CIGS CURRENTLY OVER IOWA. THAT WILL
HAVE TO BE WATCHED IN LATER FORECASTS...BUT FOR NOW WILL HOLD ON
TO THE VFR CONDITIONS THRU LATE THIS AFTN AND THEN INTRODUCE A
SCATTERED CLOUD GROUP AT AROUND 1500 FEET AT PIA LATER TODAY.
SURFACE WINDS WILL CONTINUE FROM A NORTHERLY DIRECTION TODAY AT
AROUND 10 KTS...AND THEN BACK INTO THE NORTHWEST AND THEN WEST
LATE THIS AFTN AND EVENING...WITH SPEEDS AFTR 00Z DROPPING OFF
TO AROUND 5 KTS OR LESS.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
244 AM CST SUN FEB 5 2012
.DISCUSSION...
ISSUED 240 AM CST SUN FEB 5 2012
UPPER LOW CONTINUES TO SPIN ACROSS THE CENTRAL U.S. EARLY THIS
MORNING...WITH WATER VAPOR IMAGERY SHOWING IT CENTERED NEAR KANSAS
CITY...WITH A SECOND LOW FURTHER WEST ACROSS UTAH. CLEARING LINE
HAS BEEN QUICKLY MOVING SOUTH ACROSS THE NORTHERN CWA THE LAST FEW
HOURS...AND WAS JUST SOUTH OF THE I-74 CORRIDOR AT 2 AM. INITIAL
FORECAST CHALLENGE WILL BE WITH CLEARING TREND AND FOG POTENTIAL
EARLY ON...AS CLOUDS BREAK IN AREAS THAT HAD DECENT RAINFALL THE
LAST 24-36 HOURS. HOWEVER...THE PRIMARY FORECAST ISSUE WILL BE
WITH TREND FOR COLD WEATHER TOWARD THE END OF THE WEEK.
SHORT TERM...TODAY THROUGH TUESDAY...
LATEST HRRR NOT TOO FAR OFF WITH CURRENT POSITIONING OF THE
STRATUS...AND SHOWS MUCH OF THE CWA SHOULD BE STRATUS-FREE BY LATE
MORNING. NORTHERN CWA IS MOST VULNERABLE FOR SOME FOG EARLY...WITH
LACON CURRENTLY REPORTING 3/4 MILE AND BLOOMINGTON 1-3/4 MILE AS
THE CLOUDS HAVE BROKEN. SO FAR NOTHING NORTH OF THERE IS GETTING
OUT OF HAND YET DESPITE A LONGER CLEAR PERIOD...SO WILL MAKE A
LAST MINUTE DECISION ON WHETHER TO CONTINUE FOG POTENTIAL BEYOND
SUNRISE.
MISSOURI UPPER LOW PROGGED TO DRIFT SOUTHEAST TO THE LOWER OHIO
VALLEY BY TONIGHT. ANY RESIDUAL LIGHT RAIN/DRIZZLE WILL CONTINUE
TO SHRINK WITH THIS LOW...AND WILL LIKELY ONLY MENTION IT IN THE
FAR SOUTHEAST FOR EARLY TODAY. SURFACE HIGH PRESSURE RIDGING
EASTWARD POSES ANOTHER CONCERN FOR LOW CLOUDS/FOG TONIGHT. LATEST
SREF GRAPHICS SHOWING THE NORTHWEST CWA BEING OVERSPREAD BY LOWER
STRATOCUMULUS AFTER MIDNIGHT...LASTING UNTIL ABOUT MID-MORNING
MONDAY. GIVEN THAT THIS AREA SHOULD SEE DECENT SUNSHINE MUCH OF
TODAY TO HELP DRY THINGS OUT...AM NOT OVERLY CONFIDENT IN THIS
CLOUD SCENARIO AT THE MOMENT. FOR NOW...WILL GO WITH PARTLY CLOUDY
CONDITIONS ACROSS THE NORTHWEST TONIGHT AND MAINLY CLEAR
ELSEWHERE...WITH THE DAY SHIFT MAKING ANY FURTHER ADJUSTMENTS AS
THE DAYTIME TRENDS PLAY OUT.
LEFTOVER CUTOFF ENERGY OVER THE CENTRAL ROCKIES SHOULD WEAKEN AND
GET PICKED UP BY A TROUGH MOVING ALONG THE CANADIAN BORDER MONDAY
NIGHT AND TUESDAY. NOT A LOT OF MOISTURE AVAILABLE OVERHEAD WHEN
IT ARRIVES...BUT SOME RESIDUAL MOISTURE ACCOMPANYING THE LEFTOVER
ENERGY IS ENOUGH TO WARRANT SLIGHT CHANCE POPS FOR TUESDAY AND
TUESDAY NIGHT.
LONG TERM...WEDNESDAY THROUGH SATURDAY...
QUIET WEATHER EXPECTED MIDWEEK AS HIGH PRESSURE DRIFTS ACROSS THE
MIDWEST. MAIN CONCERN REMAINS WITH THE AMOUNT OF ARCTIC AIR THAT
WILL BE DROPPING SOUTHEASTWARD LATE IN THE WEEK. GFS BRINGS 850 MB
TEMPERATURES OF -16C ACROSS MOST OF THE CWA BY FRIDAY EVENING...
WHILE ECMWF GIVES US MORE OF A GLANCING BLOW WITH THE CORE OF THE
COLDER AIR CLOSER TO THE GREAT LAKES. HAVE BEGUN TO TREND DOWNWARD
WITH THE TEMPERATURE FORECASTS AS THE MAIN IDEA HAS BEEN
PERSISTENT FOR A COUPLE DAYS NOW...BUT NOT AS AGGRESSIVELY AS THE
GFS WOULD INDICATE...WHICH GIVES THE NORTHERN CWA A STRUGGLE TO
REACH 20 DEGREES ON FRIDAY. THAT MAY BE TOUGH WITHOUT ANY SNOW ON
THE GROUND...BUT WE SHOULD STILL SEE SOMEWHAT OF A COLD SNAP IN
AN OTHERWISE MILD WINTER.
GEELHART
&&
.AVIATION...
ISSUED 1125 PM CST SAT FEB 4 2012
IFR CONDITIONS WILL CONTINUE AT SPI/DEC/CMI FOR A 2-3 MORE HOURS
AS THE LOWER CLOUDS WILL CONTINUE TO BE PUSHED SOUTH OVERNIGHT.
CMI SHOULD GO FIRST AROUND 08Z WITH SPI & DEC AT 09Z. THEN AC
CLOUDS AROUND 8KFT WILL DOMINATE THE AREA UNTIL THE MORNING HOURS.
PIA IS ALREADY THERE WITH VFR CONDITIONS WHILE BMI SHOULD BE
THERE AT TAF ISSUANCE TIME...THOUGH WITH SOME LIGHT FOG. WITH PIA
AND BMI CLEARING OUT FIRST IN THE EARLY MORNING HOURS...BELIEVE
SOME LIGHT FOG IS POSSIBLE. SO HAVE A THIS IN THE TAFS WITH A 3HR
TEMPO GROUP FOR LOWER VIS. COULD BE SOME LIGHT FOR AT SPI/DEC/CMI
BUT ONLY TEMPO SINCE THEY WILL NOT CLEAR OUT UNTIL AFTER SUNRISE.
WITH LOTS OF LOW LEVEL MOISTURE AROUND FROM THE RAIN LAT NIGHT AND
TODAY...BELIEVE ONCE THE SUN HITS IT...CU WILL DEVELOP FOR THE
LATE MORNING AND INTO THE AFTERNOON. WITH RIDGING AND ANTICYCLONIC
FLOW MOVING IN WILL GO WITH ONLY SCATTERED CU AND NO BROKEN CIGS.
HEIGHT OF CU SHOULD BE AROUND 3KFT. CU WILL DISSIPATE DURING THE
EVENING LEAVING CLEAR SKIES FOR THE EVENING HOURS. NORTH-NORTHEAST
WINDS WILL BECOME NORTHERLY DURING THE MORNING HOURS AND DECREASE
IN SPEED AS SURFACE RIDGING BUILDS IN FROM THE WEST. THEN EXPECT
NORTHWEST WINDS TOMORROW EVENING.
AUTEN
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
840 PM EST MON FEB 6 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
HIGH PRESSURE WILL GIVE WAY TO AN UPPER WAVE TUESDAY NIGHT THAT
WILL BRING SMALL CHANCES FOR SNOW TO CENTRAL INDIANA INTO
WEDNESDAY MORNING. ANOTHER COUPLE OF WEAK WAVES WILL MOVE THROUGH
EARLY IN THE WEEKEND AND AGAIN ON MONDAY AND BRING MORE SMALL
CHANCES FOR PRECIPITATION. TEMPERATURES WILL ACTUALLY DROP TO NEAR
NORMAL FROM MIDWEEK THROUGH THE WEEKEND WITH BROAD TROUGHING OVER
THE EASTERN PART OF THE COUNTRY.
&&
.NEAR TERM /TONIGHT/...
WITH HIGH PRESSURE SUBSIDENCE OVER THE AREA AND A STRATUS DECK TO
THE WEST WITH WESTERLY LOW LEVEL FLOW OVERNIGHT THINK STRATUS WILL
ADVECT BACK INTO THE NORTHWEST AND OVERSPREAD THE NORTHWESTERN TWO
THIRDS OF THE AREA DURING THE OVERNIGHT HOURS SINCE THERE WILL BE
NOTHING TO STOP IT. WHILE LARGE SCALE MODELS DO NOT DO A GOOD JOB
DEPICTING THIS LOW LEVEL RH FIELDS AND SOUNDINGS FROM THE RUC SHOW
THIS POTENTIAL AND THE RUC DID A MUCH BETTER JOB HANDLING WHAT
HAPPENED THIS MORNING. COULD ALSO SEE SOME PATCHY FOG ACROSS THE
AREA. NOT SURE OF EXTENT OR SPECIFIC LOCATION OF FOG...BUT WITH
RECENT MORNINGS AND FORECAST SOUNDINGS WILL GO AHEAD AND PUT PATCHY
FOG EVERYWHERE. WITH THE INCREASE IN CLOUD COVER THAT THE GFS AND
NAM DON/T HAVE ALSO WENT WITH WARMER LOWS THAN GUIDANCE OVER ALL BUT
THE SOUTHEAST WHERE STRATUS MAY NOT REACH.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
FORECAST FOCUS IS ON CLOUD COVER TUESDAY AND POPS WITH TUESDAY
NIGHT/WEDNESDAY SYSTEM. MODELS ARE IN DECENT AGREEMENT AND WILL USE
A CONSENSUS APPROACH FOR THE MOST PART.
AFOREMENTIONED STRATUS MAY ERODE SOME IN THE LATE MORNING TUESDAY
BUT WILL ALSO START TO SEE AN INCREASE IN CLOUDS AS THE NEXT UPPER
WAVE APPROACHES FROM THE NORTHWEST...SO NET RESULT SHOULD BE MOSTLY
CLOUDY SKIES TO EVEN CLOUDY SKIES IN THE NORTHWEST. WITH MORE CLOUD
COVER IN THE NORTH AND CENTRAL WILL ALSO DROP HIGHS THERE FROM
GUIDANCE. THE UPPER WAVE MOVING IN TUESDAY NIGHT PROVIDES ONLY WEAK
TO AT MOST MODERATE UPPER LEVEL FORCING AND THERE IS NOTHING ELSE
HELPING THIS SYSTEM...NO INSTABILITY...NO LOW LEVEL FORCING...AND
LITTLE MOISTURE. THE BEST FORCING STILL APPEARS TO BE MOVING THROUGH
BETWEEN 6 AND 12Z AND THUS KEPT LOW CHANCE POPS GOING THEN WITH
SLIGHT CHANCES FOR 6 HOURS ON EITHER SIDE. SOUNDINGS IN ALL BUT THE
SOUTH LOOK COLD ENOUGH FOR ALL SNOW. WILL START WITH A RAIN SNOW MIX
IN THE SOUTH BEFORE CHANGING OVER TO ALL SNOW. LITTLE TO NO
ACCUMULATION EXPECTED.
BY WEDNESDAY 18Z THE UPPER WAVE HAS MOVED OUT OF THE AREA AND
RIDGING IS MOVING BACK INTO THE AREA FROM THEN ON SO DRY WEATHER
FROM THAT POINT THROUGH THURSDAY. WENT COOLER THAN GUIDANCE
WEDNESDAY WITH COLD ADVECTION OCCURRING.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
OVERALL THE EXTENDED WILL BE A QUIET PERIOD. HOWEVER THERE ARE TWO
SYSTEMS THAT MAY GIVE LOW CHANCES OF PRECIP. ONE PERIOD IS FRIDAY
AFTERNOON AND NIGHT AS COLD FRONT MOVES THROUGH FRIDAY AFTERNOON
FOLLOWED BY AN UPPER TROUGH FRIDAY NIGHT AND SATURDAY. THE GFS STILL
HAS US DRY...BUT THE EUROPEAN AND CANADIAN AS WELL AS CONSALL GIVES
US LOW CHANCES OF PRECIPITATION. TEMPERATURES MAY BE WARM ENOUGH
FOR MIXED PRECIP ACROSS OUR SOUTH FRIDAY AFTERNOON. OTHERWISE...WILL
GO WITH A SLIGHT CHANCE OF SNOW SHOWERS.
THE UPPER TROUGH MOVES ON TO THE EAST OVER THE WEEKEND AND WARM
ADVECTION SETS UP BY MONDAY AHEAD OF THE NEXT SYSTEM. THE GFS
BARELY BRINGS PRECIP INTO OUR NORTHWEST BY 00Z TUESDAY AND THE
EUROPEAN IS EVEN SLOWER. WILL TRIM POPS A LITTLE...BUT KEEP LOW
CHANCES ACROSS OUR WEST BY LATE DAY 7. DID NOT MAKE ANY SIGNIFICANT
CHANGE TO ALL BLEND TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 07/03Z IND TAF UPDATE/...
HAVE AMENDED IND AS STRATUS HAS BEGUN TO ADVECT EASTWARD TOWARD THE
SITE. HAVE ROUGHLY TIMED OVC010-OVC012 DECK TO IND BY AROUND 0230Z.
WILL ALLOW THIS TO SERVE AS 3 HOUR AMENDMENT UNLESS SIGNIFICANT
CHANGE REQUIRED NEXT HOUR.
LOW CONFIDENCE FORECAST AS ALMOST NO GUIDANCE EXCEPT LAF EVEN
SUGGESTS ANY RESTRICTIONS OVERNIGHT...BUT FORECAST SOUNDINGS AND RUC
LOW LEVEL RH FIELDS...WHICH MATCH WELL WITH CURRENT IFR
CLOUD...SUGGEST AN EXPANSION OF STRATUS/FOG INTO THE SITES OVERNIGHT.
IF UPSTREAM OBS FROM THIS MORNING AND TODAY ARE ANY
INDICATION...LIFR CAN BE EXPECTED OVERNIGHT INTO TOMORROW. WILL HAVE
TO MONITOR THE PROGRESSION OF STRATUS THIS EVENING TO DETERMINE
WHETHER THIS WILL HOLD UP.
WINDS WILL GENERALLY BE OUT OF THE WEST THIS EVENING...BECOMING MORE
NORTHWEST AND VERY LIGHT TO CALM LATE...BEFORE BECOMING MORE
NORTHERLY TOMORROW. SPEEDS SHOULD BE LESS THAN 10KT THROUGHOUT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP/SMF
SHORT TERM...CP
LONG TERM....JH
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
814 PM EST MON FEB 6 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
HIGH PRESSURE WILL GIVE WAY TO AN UPPER WAVE TUESDAY NIGHT THAT
WILL BRING SMALL CHANCES FOR SNOW TO CENTRAL INDIANA INTO
WEDNESDAY MORNING. ANOTHER COUPLE OF WEAK WAVES WILL MOVE THROUGH
EARLY IN THE WEEKEND AND AGAIN ON MONDAY AND BRING MORE SMALL
CHANCES FOR PRECIPITATION. TEMPERATURES WILL ACTUALLY DROP TO NEAR
NORMAL FROM MIDWEEK THROUGH THE WEEKEND WITH BROAD TROUGHING OVER
THE EASTERN PART OF THE COUNTRY.
&&
.NEAR TERM /TONIGHT/...
WITH HIGH PRESSURE SUBSIDENCE OVER THE AREA AND A STRATUS DECK TO
THE WEST WITH WESTERLY LOW LEVEL FLOW OVERNIGHT THINK STRATUS WILL
ADVECT BACK INTO THE NORTHWEST AND OVERSPREAD THE NORTHWESTERN TWO
THIRDS OF THE AREA DURING THE OVERNIGHT HOURS SINCE THERE WILL BE
NOTHING TO STOP IT. WHILE LARGE SCALE MODELS DO NOT DO A GOOD JOB
DEPICTING THIS LOW LEVEL RH FIELDS AND SOUNDINGS FROM THE RUC SHOW
THIS POTENTIAL AND THE RUC DID A MUCH BETTER JOB HANDLING WHAT
HAPPENED THIS MORNING. COULD ALSO SEE SOME PATCHY FOG ACROSS THE
AREA. NOT SURE OF EXTENT OR SPECIFIC LOCATION OF FOG...BUT WITH
RECENT MORNINGS AND FORECAST SOUNDINGS WILL GO AHEAD AND PUT PATCHY
FOG EVERYWHERE. WITH THE INCREASE IN CLOUD COVER THAT THE GFS AND
NAM DON/T HAVE ALSO WENT WITH WARMER LOWS THAN GUIDANCE OVER ALL BUT
THE SOUTHEAST WHERE STRATUS MAY NOT REACH.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
FORECAST FOCUS IS ON CLOUD COVER TUESDAY AND POPS WITH TUESDAY
NIGHT/WEDNESDAY SYSTEM. MODELS ARE IN DECENT AGREEMENT AND WILL USE
A CONSENSUS APPROACH FOR THE MOST PART.
AFOREMENTIONED STRATUS MAY ERODE SOME IN THE LATE MORNING TUESDAY
BUT WILL ALSO START TO SEE AN INCREASE IN CLOUDS AS THE NEXT UPPER
WAVE APPROACHES FROM THE NORTHWEST...SO NET RESULT SHOULD BE MOSTLY
CLOUDY SKIES TO EVEN CLOUDY SKIES IN THE NORTHWEST. WITH MORE CLOUD
COVER IN THE NORTH AND CENTRAL WILL ALSO DROP HIGHS THERE FROM
GUIDANCE. THE UPPER WAVE MOVING IN TUESDAY NIGHT PROVIDES ONLY WEAK
TO AT MOST MODERATE UPPER LEVEL FORCING AND THERE IS NOTHING ELSE
HELPING THIS SYSTEM...NO INSTABILITY...NO LOW LEVEL FORCING...AND
LITTLE MOISTURE. THE BEST FORCING STILL APPEARS TO BE MOVING THROUGH
BETWEEN 6 AND 12Z AND THUS KEPT LOW CHANCE POPS GOING THEN WITH
SLIGHT CHANCES FOR 6 HOURS ON EITHER SIDE. SOUNDINGS IN ALL BUT THE
SOUTH LOOK COLD ENOUGH FOR ALL SNOW. WILL START WITH A RAIN SNOW MIX
IN THE SOUTH BEFORE CHANGING OVER TO ALL SNOW. LITTLE TO NO
ACCUMULATION EXPECTED.
BY WEDNESDAY 18Z THE UPPER WAVE HAS MOVED OUT OF THE AREA AND
RIDGING IS MOVING BACK INTO THE AREA FROM THEN ON SO DRY WEATHER
FROM THAT POINT THROUGH THURSDAY. WENT COOLER THAN GUIDANCE
WEDNESDAY WITH COLD ADVECTION OCCURRING.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
OVERALL THE EXTENDED WILL BE A QUIET PERIOD. HOWEVER THERE ARE TWO
SYSTEMS THAT MAY GIVE LOW CHANCES OF PRECIP. ONE PERIOD IS FRIDAY
AFTERNOON AND NIGHT AS COLD FRONT MOVES THROUGH FRIDAY AFTERNOON
FOLLOWED BY AN UPPER TROUGH FRIDAY NIGHT AND SATURDAY. THE GFS STILL
HAS US DRY...BUT THE EUROPEAN AND CANADIAN AS WELL AS CONSALL GIVES
US LOW CHANCES OF PRECIPITATION. TEMPERATURES MAY BE WARM ENOUGH
FOR MIXED PRECIP ACROSS OUR SOUTH FRIDAY AFTERNOON. OTHERWISE...WILL
GO WITH A SLIGHT CHANCE OF SNOW SHOWERS.
THE UPPER TROUGH MOVES ON TO THE EAST OVER THE WEEKEND AND WARM
ADVECTION SETS UP BY MONDAY AHEAD OF THE NEXT SYSTEM. THE GFS
BARELY BRINGS PRECIP INTO OUR NORTHWEST BY 00Z TUESDAY AND THE
EUROPEAN IS EVEN SLOWER. WILL TRIM POPS A LITTLE...BUT KEEP LOW
CHANCES ACROSS OUR WEST BY LATE DAY 7. DID NOT MAKE ANY SIGNIFICANT
CHANGE TO ALL BLEND TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 07/00Z TAFS/...
LOW CONFIDENCE FORECAST AS ALMOST NO GUIDANCE EXCEPT LAF EVEN
SUGGESTS ANY RESTRICTIONS OVERNIGHT...BUT FORECAST SOUNDINGS AND RUC
LOW LEVEL RH FIELDS...WHICH MATCH WELL WITH CURRENT IFR
CLOUD...SUGGEST AN EXPANSION OF STRATUS/FOG INTO THE SITES OVERNIGHT.
IF UPSTREAM OBS FROM THIS MORNING AND TODAY ARE ANY
INDICATION...LIFR CAN BE EXPECTED OVERNIGHT INTO TOMORROW. WILL HAVE
TO MONITOR THE PROGRESSION OF STRATUS THIS EVENING TO DETERMINE
WHETHER THIS WILL HOLD UP.
WINDS WILL GENERALLY BE OUT OF THE WEST THIS EVENING...BECOMING MORE
NORTHWEST AND VERY LIGHT TO CALM LATE...BEFORE BECOMING MORE
NORTHERLY TOMORROW. SPEEDS SHOULD BE LESS THAN 10KT THROUGHOUT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP/SMF
SHORT TERM...CP
LONG TERM....JH
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
608 PM EST MON FEB 6 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
HIGH PRESSURE WILL GIVE WAY TO AN UPPER WAVE TUESDAY NIGHT THAT
WILL BRING SMALL CHANCES FOR SNOW TO CENTRAL INDIANA INTO
WEDNESDAY MORNING. ANOTHER COUPLE OF WEAK WAVES WILL MOVE THROUGH
EARLY IN THE WEEKEND AND AGAIN ON MONDAY AND BRING MORE SMALL
CHANCES FOR PRECIPITATION. TEMPERATURES WILL ACTUALLY DROP TO NEAR
NORMAL FROM MIDWEEK THROUGH THE WEEKEND WITH BROAD TROUGHING OVER
THE EASTERN PART OF THE COUNTRY.
&&
.NEAR TERM /TONIGHT/...
WITH HIGH PRESSURE SUBSIDENCE OVER THE AREA AND A STRATUS DECK TO
THE WEST WITH WESTERLY LOW LEVEL FLOW OVERNIGHT THINK STRATUS WILL
ADVECT BACK INTO THE NORTHWEST AND OVERSPREAD THE NORTHWESTERN TWO
THIRDS OF THE AREA DURING THE OVERNIGHT HOURS SINCE THERE WILL BE
NOTHING TO STOP IT. WHILE LARGE SCALE MODELS DO NOT DO A GOOD JOB
DEPICTING THIS LOW LEVEL RH FIELDS AND SOUNDINGS FROM THE RUC SHOW
THIS POTENTIAL AND THE RUC DID A MUCH BETTER JOB HANDLING WHAT
HAPPENED THIS MORNING. COULD ALSO SEE SOME PATCHY FOG ACROSS THE
AREA. NOT SURE OF EXTENT OR SPECIFIC LOCATION OF FOG...BUT WITH
RECENT MORNINGS AND FORECAST SOUNDINGS WILL GO AHEAD AND PUT PATCHY
FOG EVERYWHERE. WITH THE INCREASE IN CLOUD COVER THAT THE GFS AND
NAM DON/T HAVE ALSO WENT WITH WARMER LOWS THAN GUIDANCE OVER ALL BUT
THE SOUTHEAST WHERE STRATUS MAY NOT REACH.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
FORECAST FOCUS IS ON CLOUD COVER TUESDAY AND POPS WITH TUESDAY
NIGHT/WEDNESDAY SYSTEM. MODELS ARE IN DECENT AGREEMENT AND WILL USE
A CONSENSUS APPROACH FOR THE MOST PART.
AFOREMENTIONED STRATUS MAY ERODE SOME IN THE LATE MORNING TUESDAY
BUT WILL ALSO START TO SEE AN INCREASE IN CLOUDS AS THE NEXT UPPER
WAVE APPROACHES FROM THE NORTHWEST...SO NET RESULT SHOULD BE MOSTLY
CLOUDY SKIES TO EVEN CLOUDY SKIES IN THE NORTHWEST. WITH MORE CLOUD
COVER IN THE NORTH AND CENTRAL WILL ALSO DROP HIGHS THERE FROM
GUIDANCE. THE UPPER WAVE MOVING IN TUESDAY NIGHT PROVIDES ONLY WEAK
TO AT MOST MODERATE UPPER LEVEL FORCING AND THERE IS NOTHING ELSE
HELPING THIS SYSTEM...NO INSTABILITY...NO LOW LEVEL FORCING...AND
LITTLE MOISTURE. THE BEST FORCING STILL APPEARS TO BE MOVING THROUGH
BETWEEN 6 AND 12Z AND THUS KEPT LOW CHANCE POPS GOING THEN WITH
SLIGHT CHANCES FOR 6 HOURS ON EITHER SIDE. SOUNDINGS IN ALL BUT THE
SOUTH LOOK COLD ENOUGH FOR ALL SNOW. WILL START WITH A RAIN SNOW MIX
IN THE SOUTH BEFORE CHANGING OVER TO ALL SNOW. LITTLE TO NO
ACCUMULATION EXPECTED.
BY WEDNESDAY 18Z THE UPPER WAVE HAS MOVED OUT OF THE AREA AND
RIDGING IS MOVING BACK INTO THE AREA FROM THEN ON SO DRY WEATHER
FROM THAT POINT THROUGH THURSDAY. WENT COOLER THAN GUIDANCE
WEDNESDAY WITH COLD ADVECTION OCCURRING.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
OVERALL THE EXTENDED WILL BE A QUIET PERIOD. HOWEVER THERE ARE TWO
SYSTEMS THAT MAY GIVE LOW CHANCES OF PRECIP. ONE PERIOD IS FRIDAY
AFTERNOON AND NIGHT AS COLD FRONT MOVES THROUGH FRIDAY AFTERNOON
FOLLOWED BY AN UPPER TROUGH FRIDAY NIGHT AND SATURDAY. THE GFS STILL
HAS US DRY...BUT THE EUROPEAN AND CANADIAN AS WELL AS CONSALL GIVES
US LOW CHANCES OF PRECIPITATION. TEMPERATURES MAY BE WARM ENOUGH
FOR MIXED PRECIP ACROSS OUR SOUTH FRIDAY AFTERNOON. OTHERWISE...WILL
GO WITH A SLIGHT CHANCE OF SNOW SHOWERS.
THE UPPER TROUGH MOVES ON TO THE EAST OVER THE WEEKEND AND WARM
ADVECTION SETS UP BY MONDAY AHEAD OF THE NEXT SYSTEM. THE GFS
BARELY BRINGS PRECIP INTO OUR NORTHWEST BY 00Z TUESDAY AND THE
EUROPEAN IS EVEN SLOWER. WILL TRIM POPS A LITTLE...BUT KEEP LOW
CHANCES ACROSS OUR WEST BY LATE DAY 7. DID NOT MAKE ANY SIGNIFICANT
CHANGE TO ALL BLEND TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 07/00Z TAFS/...
LOW CONFIDENCE FORECAST AS ALMOST NO GUIDANCE EXCEPT LAF EVEN
SUGGESTS ANY RESTRICTIONS OVERNIGHT...BUT FORECAST SOUNDINGS AND RUC
LOW LEVEL RH FIELDS...WHICH MATCH WELL WITH CURRENT IFR
CLOUD...SUGGEST AN EXPANSION OF STRATUS/FOG INTO THE SITES OVERNIGHT.
IF UPSTREAM OBS FROM THIS MORNING AND TODAY ARE ANY
INDICATION...LIFR CAN BE EXPECTED OVERNIGHT INTO TOMORROW. WILL HAVE
TO MONITOR THE PROGRESSION OF STRATUS THIS EVENING TO DETERMINE
WHETHER THIS WILL HOLD UP.
WINDS WILL GENERALLY BE OUT OF THE WEST THIS EVENING...BECOMING MORE
NORTHWEST AND VERY LIGHT TO CALM LATE...BEFORE BECOMING MORE
NORTHERLY TOMORROW. SPEEDS SHOULD BE LESS THAN 10KT THROUGHOUT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....JH
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
340 PM EST SUN FEB 5 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...A SUNNY...SUPER AFTERNOON ACROSS CENTRAL INDIANA WILL
LEAD TO A CLEAR NIGHT WITH SOME POTENTIAL FOR FOG LATE. A SERIES OF
WEAK UPPER WAVES WILL MOVE THROUGH THE FLOW THIS WEEK BUT HIGH
PRESSURE WILL BE THE RULE AT THE SURFACE SO PRECIPITATION CHANCES
FOR MOST OF THE WEEK ARE SMALL.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
VISIBLE SATELLITE LOOP AT 20Z SHOWS SUNNY SKIES ACROSS THE
AREA...AND LATEST OBSERVATIONS SHOW TEMPERATURES RANGING FROM THE
MIDDLE 40S TO AROUND 50...MAKING IT A SUPER WEATHER DAY FOR FEBRUARY
IN CENTRAL INDIANA. CLEAR SKIES WILL CONTINUE INTO TONIGHT WITH HIGH
PRESSURE BUILDING IN AND WINDS WILL GO CALM OR NEAR CALM. THIS WILL
LEAD TO THE POTENTIAL FOR SOME FOG OVERNIGHT. WITH THE SUNSHINE THE
AREA RECEIVED TODAY SOILS SHOULD HAVE HAD PLENTY OF TIME TO DRY OUT
SOME AND DEW POINTS ARE RUNNING DRIER THAN GUIDANCE SO AS OF NOW DO
NOT ANTICIPATE WIDESPREAD DENSE FOG...JUST SOME PATCHY FOG ACROSS
THE AREA DEVELOPING LATE AND LASTING UNTIL A COUPLE OF HOURS AFTER
SUNRISE.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL CONTINUE TO BE IN PLACE AT THE SURFACE WITH THE
CUTOFF UPPER LOW MAKING ITS WAY EAST JUST SOUTH OF THE AREA ON
MONDAY. THIS COULD LEAD TO INCREASED CLOUD COVER IN THE SOUTH BUT
THAT/S IT AS FORCING IS FAIRLY WEAK AND MOISTURE IS LIMITED. UPPER
RIDGING WILL BE IN PLACE FOR MONDAY NIGHT AND TUESDAY WHICH WILL
KEEP THE AREA DRY. BY TUESDAY NIGHT THOUGH AN UPPER WAVE WILL
APPROACH AND BRING SOME FORCING TO THE AREA THAT COULD LAST THROUGH
WEDNESDAY BUT SHOULD BE THROUGH BY WEDNESDAY NIGHT. THERE IS STILL SOME
MODEL DISCREPANCY ON TIMING...BUT THE NAM SEEMS TO BE A SLOW OUTLIER
WITH THE SREFS/GFS/ECMWF ALL POINTING TO SOMETIME IN THE TUESDAY
NIGHT TO WEDNESDAY TIME FRAME AND ONLY THE NAM HOLDING ON TO PRECIP
INTO WEDNESDAY NIGHT. ONLY WENT WITH A SLIGHT CHANCE FOR
PRECIPITATION ON TUESDAY NIGHT AND WEDNESDAY SINCE THERE IS HIGH
PRESSURE AT THE SURFACE AND MOISTURE WILL BE LIMITED...BUT UPPER
FORCING IS SUFFICIENT TO JUSTIFY A SLIGHT CHANCE. SOUNDINGS FOR THAT
TIME SUGGEST SNOW AS THE POTENTIAL PRECIPITATION TYPE SHOULD IT
OCCUR.
FOR TEMPERATURES GENERALLY USED A GUIDANCE CONSENSUS WITH GOOD
AGREEMENT THERE. THE EXCEPTION IS ON WEDNESDAY WHEN COLD ADVECTION
IS IN PLACE AN 850 MB TEMPERATURES FROM THE ECMWF AND GFS BOTH SHOW
-10C OVER THE AREA. THOUGHT GUIDANCE WAS TOO HIGH GIVEN THE ABOVE
AND INSTEAD WENT WITH AN AVERAGE OF THE GFS AND ECM.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THERE ARE A COUPLE OF PERIODS WHERE SLIGHT CHANCE OF PRECIP IS
POSSIBLE MAINLY WEDNESDAY EVENING AND AGAIN FRIDAY. HOWEVER MODELS
HAVE TRENDED DRIER WITH EACH RUN AND ALL BLEND ONLY GIVES A 15-20
PERCENT CHANCE AT MOST OF PRECIP THOSE PERIODS. AT THIS POINT HAVE
DECIDED TO TAKE OUT MENTION OF PRECIP AS NOW DRY THROUGH THE PERIODS
AND THERE ARE ONLY A FEW WEAK SYSTEMS TO KEY ON.
MODELS MOVE AN UPPER SHORT WAVE ACROSS THE OHIO VALLEY EARLY
WEDNESDAY EVENING. THEN HIGH PRESSURE WILL DOMINATE OUR WEATHER
THURSDAY. ON FRIDAY A DRY COLD FRONT WILL MOVE ACROSS OUR REGION AS
A BROAD UPPER TROUGH ROTATES ACROSS THE GREAT LAKES AND MIDWEST.
ONCE AGAIN THERE IS LIMITED MOISTURE AVAILABLE WITH THIS SYSTEM.
HIGH PRESSURE BEHIND THIS SYSTEM WILL MOVE ACROSS OUR REGION OVER
THE WEEKEND. OVERALL DID NOT MAKE ANY SIGNIFICANT CHANGES TO ALL
BLEND PARAMETERS.
&&
.AVIATION /DISCUSSION FOR 052100Z TAF UPDATE/...
ONLY VERY MINOR CHANGES BASED ON LATEST OBSERVATIONS. PREVIOUS
DISCUSSION FOLLOWS.
SATELLITE AT 1630Z SHOWS SOME LINGERING STRATUS WEST OF KLAF AND
ALONG AND SOUTH OF A KLWV-KBMG-KBAK LINE. THIS STRATUS WILL CONTINUE
TO CLEAR AND NO SIGNIFICANT CLOUD COVER IS EXPECTED THROUGH THE
PERIOD WITH MOSTLY VFR AND CLEAR SKIES THROUGH THE PERIOD.
THE ONLY ISSUE WILL BE POSSIBILITY OF SOME FOG LATE TONIGHT AND
EARLY MONDAY AS WINDS WILL BE LIGHT AND STRONG RADIATIONAL COOLING
OCCURS DURING THE OVERNIGHT HOURS. THE NAM MODEL SOUNDING INDICATES
NEAR SATURATION NEAR THE SURFACE AND THE RUC SHOWS EVEN A LITTLE
MORE BEGINNING AFTER 09Z. THERE WERE SOME AREAS OF FOG UPSTREAM
THIS MORNING SO WILL ADD MENTION OF SOME MVFR FOG ALL SITES TOWARDS
SUNRISE. ON THE NEGATIVE SIDE...THE GROUND WILL HAVE SOME TIME TO
DRY OUT THIS AFTERNOON AS THERE WILL BE FULL SUNSHINE ACROSS THE
AREA.
WINDS TODAY WILL BE FROM THE NORTHEAST 5 TO 8 KNOTS THIS
AFTERNOON...THEN LIGHT TONIGHT AND BECOMING SOUTHWEST 7 TO 10 KNOTS
AFTER 15Z MONDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....JH
AVIATION...JK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
330 PM EST SUN FEB 5 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
CLOUDS WILL DEPART EARLY THIS MORNING WITH FOG BURNING OFF THROUGH
THE MORNING AS HIGH PRESSURE BUILDS INTO CENTRAL INDIANA. THE HIGH
WILL BRING DRY WEATHER AND MAINLY CLEAR SKIES THROUGH TUESDAY. A
WEAK UPPER LEVEL DISTURBANCE WILL PROVIDE A CHANCE FOR LIGHT RAIN
AND SNOW TUESDAY NIGHT AND WEDNESDAY. THE EXPANSION OF A BROAD UPPER
LEVEL TROUGH WILL SIGNAL A SHIFT TO COLDER TEMPERATURES FOR LATE
WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
TEMPERATURES HAVE RISEN ABOVE FREEZING AND FOG HAS DISSIPATED
ACROSS THE AREA...SO ALLOWED FREEZING FOG ADVISORY IN THE NORTH TO
EXPIRE AT 10 AM. CLEARING OF LOWER CLOUD DECK WILL CONTINUE TO
OCCUR FROM NORTH TO SOUTH AS HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST...MAKING FOR A MOSTLY SUNNY DAY ACROSS THE AREA. HIGH
TEMPERATURES IN THE MIDDLE TO UPPER 40S STILL LOOK GOOD AT THIS
TIME WITH LIGHT NORTHEASTERLY TO NORTHERLY WINDS. COMPARED WITH
THE LIGHT RAIN AND COOL CONDITIONS YESTERDAY A SUPER DAY IS IN
STORE TODAY FOR CENTRAL INDIANA.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES TUESDAY NIGHT AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE REGION.
MUCH OF THE SHORT TERM WILL REMAIN TRANQUIL AS BROAD HIGH PRESSURE
RIDGE DOMINATES THE WEATHER PATTERN OVER THE OHIO VALLEY. MODEL
SOUNDINGS MAINTAIN DEEP SUBSIDENCE OVER CENTRAL INDIANA THROUGH
MONDAY NIGHT WHICH SHOULD KEEP SKIES LARGELY CLOUD-FREE. REMNANT
UPPER LEVEL FEATURE FROM SYSTEM THIS WEEKEND WILL PASS TO THE SOUTH
OF THE REGION WITH LITTLE FANFARE AS A RESULT. WEAK FRONTAL BOUNDARY
DROPS THROUGH THE FORECAST AREA LATE MONDAY NIGHT INTO TUESDAY BUT
WILL ONLY BRING A SUBTLE INCREASE IN HIGHER CLOUDS AS NO APPRECIABLE
MOISTURE IS PRESENT.
MODELS CONVERGING ON THE ARRIVAL OF ISENTROPIC LIFT AND MOISTURE
AHEAD OF A MID LEVEL SHORT WAVE TUESDAY NIGHT. WHILE TIMING OF THE
SHORT WAVE VARIES BETWEEN THE MODELS...INTRODUCTION OF LOW CHANCE
POPS FOR TUESDAY NIGHT APPEARS WARRANTED. ANALYSIS OF LOW LEVEL
THERMALS SUPPORT POTENTIAL OF A RA/SN MIX CHANGING PREDOMINANTLY
OVER TO LIGHT SNOW AS THE NIGHT PROGRESSES. AT THIS POINT...PRECIP
AMOUNTS LOOK LIMITED AT ONLY A COUPLE HUNDREDTHS WITH SNOW ACCUMS OF
A FEW TENTHS OF AN INCH AT BEST OVER NORTHERN COUNTIES.
TEMPS...LOW LEVEL THERMAL PROFILES SUPPORTED MOS GUIDANCE THROUGH
MUCH OF THE PERIOD. TEMPS ON MONDAY SHOULD BE A FEW DEGREES WARMER
THAN TODAY WITH ABUNDANT SUNSHINE AND SOUTHWEST FLOW DEVELOPING.
PASSAGE OF THE WEAK FRONT EARLY TUESDAY WILL SERVE TO KNOCK HIGHS
DOWN A FEW DEGREES TUESDAY...WITH COLDER AIR ARRIVING TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE MAIN FORECAST CHALLENGES FOR THE PERIOD ARE PRECIPITATION
CHANCES AND TEMPERATURES LATE IN THE PERIOD AS A DECENT PUSH OF
COLDER AIR SLIDES DOWN FROM CANADA.
THE MODELS ARE BEGINNING TO COME INTO AGREEMENT WITH THE TIMING OF
AN UPPER LEVEL WAVE PASSING THROUGH THE FORECAST AREA ON WEDNESDAY
WITH THE ECMWF JUST SLIGHTLY FASTER THAN THE GFS AND CANADIAN.
SUFFICIENT MOISTURE STILL LOOKS TO BE THE LIMITING FACTOR SO
STICKING WITH CHANCE POPS PROVIDED BY ALLBLEND SEEMS LIKE THE BEST
MOVE FOR NOW. ALSO INTRODUCED A SLIGHT CHANCE ACROSS THE EAST FOR
WEDNESDAY NIGHT TO ACCOUNT FOR THE SLIGHTLY SLOWER MODEL SOLUTIONS.
WITH TEMPERATURES CONTINUING TO BE AROUND NORMAL VALUES...LOWS IN
THE MID 20S AND HIGHS IN THE MID 30S...CONTINUED WITH A RAIN/SNOW
MIX IN THE GRIDS.
SURFACE HIGH PRESSURE WILL SLIDE ACROSS THE REGION ON THURSDAY. THIS
WILL CAUSE SOUTHWESTERLY WINDS TO RETURN ALLOWING TEMPERATURES TO
RISE TO ABOVE NORMAL VALUES ONCE AGAIN. HOWEVER...THE WARM UP WILL
BE SHORT LIVED AS A STRONG UPPER LOW NEAR HUDSON BAY TRANSPORTS A
MUCH COLDER AIRMASS TOWARDS CENTRAL INDIANA. DECREASED ALLBLEND
TEMPERATURES 2-3 DEGREES HEADING INTO THE WEEKEND WITH THE GFS
DEPICTING 850 MB TEMPERATURES APPROACHING -20 C.
&&
.AVIATION /DISCUSSION FOR 052100Z TAF UPDATE/...
ONLY VERY MINOR CHANGES BASED ON LATEST OBSERVATIONS. PREVIOUS
DISCUSSION FOLLOWS.
SATELLITE AT 1630Z SHOWS SOME LINGERING STRATUS WEST OF KLAF AND
ALONG AND SOUTH OF A KLWV-KBMG-KBAK LINE. THIS STRATUS WILL CONTINUE
TO CLEAR AND NO SIGNIFICANT CLOUD COVER IS EXPECTED THROUGH THE
PERIOD WITH MOSTLY VFR AND CLEAR SKIES THROUGH THE PERIOD.
THE ONLY ISSUE WILL BE POSSIBILITY OF SOME FOG LATE TONIGHT AND
EARLY MONDAY AS WINDS WILL BE LIGHT AND STRONG RADIATIONAL COOLING
OCCURS DURING THE OVERNIGHT HOURS. THE NAM MODEL SOUNDING INDICATES
NEAR SATURATION NEAR THE SURFACE AND THE RUC SHOWS EVEN A LITTLE
MORE BEGINNING AFTER 09Z. THERE WERE SOME AREAS OF FOG UPSTREAM
THIS MORNING SO WILL ADD MENTION OF SOME MVFR FOG ALL SITES TOWARDS
SUNRISE. ON THE NEGATIVE SIDE...THE GROUND WILL HAVE SOME TIME TO
DRY OUT THIS AFTERNOON AS THERE WILL BE FULL SUNSHINE ACROSS THE
AREA.
WINDS TODAY WILL BE FROM THE NORTHEAST 5 TO 8 KNOTS THIS
AFTERNOON...THEN LIGHT TONIGHT AND BECOMING SOUTHWEST 7 TO 10 KNOTS
AFTER 15Z MONDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...CP
SHORT TERM...RYAN
LONG TERM....HOMANN/RYAN
AVIATION...JK
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1205 PM EST SUN FEB 5 2012
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
CLOUDS WILL DEPART EARLY THIS MORNING WITH FOG BURNING OFF THROUGH
THE MORNING AS HIGH PRESSURE BUILDS INTO CENTRAL INDIANA. THE HIGH
WILL BRING DRY WEATHER AND MAINLY CLEAR SKIES THROUGH TUESDAY. A
WEAK UPPER LEVEL DISTURBANCE WILL PROVIDE A CHANCE FOR LIGHT RAIN
AND SNOW TUESDAY NIGHT AND WEDNESDAY. THE EXPANSION OF A BROAD UPPER
LEVEL TROUGH WILL SIGNAL A SHIFT TO COLDER TEMPERATURES FOR LATE
WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
TEMPERATURES HAVE RISEN ABOVE FREEZING AND FOG HAS DISSIPATED
ACROSS THE AREA...SO ALLOWED FREEZING FOG ADVISORY IN THE NORTH TO
EXPIRE AT 10 AM. CLEARING OF LOWER CLOUD DECK WILL CONTINUE TO
OCCUR FROM NORTH TO SOUTH AS HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST...MAKING FOR A MOSTLY SUNNY DAY ACROSS THE AREA. HIGH
TEMPERATURES IN THE MIDDLE TO UPPER 40S STILL LOOK GOOD AT THIS
TIME WITH LIGHT NORTHEASTERLY TO NORTHERLY WINDS. COMPARED WITH
THE LIGHT RAIN AND COOL CONDITIONS YESTERDAY A SUPER DAY IS IN
STORE TODAY FOR CENTRAL INDIANA.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES TUESDAY NIGHT AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE REGION.
MUCH OF THE SHORT TERM WILL REMAIN TRANQUIL AS BROAD HIGH PRESSURE
RIDGE DOMINATES THE WEATHER PATTERN OVER THE OHIO VALLEY. MODEL
SOUNDINGS MAINTAIN DEEP SUBSIDENCE OVER CENTRAL INDIANA THROUGH
MONDAY NIGHT WHICH SHOULD KEEP SKIES LARGELY CLOUD-FREE. REMNANT
UPPER LEVEL FEATURE FROM SYSTEM THIS WEEKEND WILL PASS TO THE SOUTH
OF THE REGION WITH LITTLE FANFARE AS A RESULT. WEAK FRONTAL BOUNDARY
DROPS THROUGH THE FORECAST AREA LATE MONDAY NIGHT INTO TUESDAY BUT
WILL ONLY BRING A SUBTLE INCREASE IN HIGHER CLOUDS AS NO APPRECIABLE
MOISTURE IS PRESENT.
MODELS CONVERGING ON THE ARRIVAL OF ISENTROPIC LIFT AND MOISTURE
AHEAD OF A MID LEVEL SHORT WAVE TUESDAY NIGHT. WHILE TIMING OF THE
SHORT WAVE VARIES BETWEEN THE MODELS...INTRODUCTION OF LOW CHANCE
POPS FOR TUESDAY NIGHT APPEARS WARRANTED. ANALYSIS OF LOW LEVEL
THERMALS SUPPORT POTENTIAL OF A RA/SN MIX CHANGING PREDOMINANTLY
OVER TO LIGHT SNOW AS THE NIGHT PROGRESSES. AT THIS POINT...PRECIP
AMOUNTS LOOK LIMITED AT ONLY A COUPLE HUNDREDTHS WITH SNOW ACCUMS OF
A FEW TENTHS OF AN INCH AT BEST OVER NORTHERN COUNTIES.
TEMPS...LOW LEVEL THERMAL PROFILES SUPPORTED MOS GUIDANCE THROUGH
MUCH OF THE PERIOD. TEMPS ON MONDAY SHOULD BE A FEW DEGREES WARMER
THAN TODAY WITH ABUNDANT SUNSHINE AND SOUTHWEST FLOW DEVELOPING.
PASSAGE OF THE WEAK FRONT EARLY TUESDAY WILL SERVE TO KNOCK HIGHS
DOWN A FEW DEGREES TUESDAY...WITH COLDER AIR ARRIVING TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE MAIN FORECAST CHALLENGES FOR THE PERIOD ARE PRECIPITATION
CHANCES AND TEMPERATURES LATE IN THE PERIOD AS A DECENT PUSH OF
COLDER AIR SLIDES DOWN FROM CANADA.
THE MODELS ARE BEGINNING TO COME INTO AGREEMENT WITH THE TIMING OF
AN UPPER LEVEL WAVE PASSING THROUGH THE FORECAST AREA ON WEDNESDAY
WITH THE ECMWF JUST SLIGHTLY FASTER THAN THE GFS AND CANADIAN.
SUFFICIENT MOISTURE STILL LOOKS TO BE THE LIMITING FACTOR SO
STICKING WITH CHANCE POPS PROVIDED BY ALLBLEND SEEMS LIKE THE BEST
MOVE FOR NOW. ALSO INTRODUCED A SLIGHT CHANCE ACROSS THE EAST FOR
WEDNESDAY NIGHT TO ACCOUNT FOR THE SLIGHTLY SLOWER MODEL SOLUTIONS.
WITH TEMPERATURES CONTINUING TO BE AROUND NORMAL VALUES...LOWS IN
THE MID 20S AND HIGHS IN THE MID 30S...CONTINUED WITH A RAIN/SNOW
MIX IN THE GRIDS.
SURFACE HIGH PRESSURE WILL SLIDE ACROSS THE REGION ON THURSDAY. THIS
WILL CAUSE SOUTHWESTERLY WINDS TO RETURN ALLOWING TEMPERATURES TO
RISE TO ABOVE NORMAL VALUES ONCE AGAIN. HOWEVER...THE WARM UP WILL
BE SHORT LIVED AS A STRONG UPPER LOW NEAR HUDSON BAY TRANSPORTS A
MUCH COLDER AIRMASS TOWARDS CENTRAL INDIANA. DECREASED ALLBLEND
TEMPERATURES 2-3 DEGREES HEADING INTO THE WEEKEND WITH THE GFS
DEPICTING 850 MB TEMPERATURES APPROACHING -20 C.
&&
.AVIATION /DISCUSSION FOR THE 06/18Z TAF ISSUANCE/...
SATELLITE AT 1630Z SHOWS SOME LINGERING STRATUS WEST OF KLAF AND
ALONG AND SOUTH OF A KLWV-KBMG-KBAK LINE. THIS STRATUS WILL CONTINUE
TO CLEAR AND NO SIGNIFICANT CLOUD COVER IS EXPECTED THROUGH THE
PERIOD WITH MOSTLY VFR AND CLEAR SKIES THROUGH THE PERIOD.
THE ONLY ISSUE WILL BE POSSIBILITY OF SOME FOG LATE TONIGHT AND
EARLY MONDAY AS WINDS WILL BE LIGHT AND STRONG RADIATIONAL COOLING
OCCURS DURING THE OVERNIGHT HOURS. THE NAM MODEL SOUNDING INDICATES
NEAR SATURATION NEAR THE SURFACE AND THE RUC SHOWS EVEN A LITTLE
MORE BEGINNING AFTER 09Z. THERE WERE SOME AREAS OF FOG UPSTREAM
THIS MORNING SO WILL ADD MENTION OF SOME MVFR FOG ALL SITES TOWARDS
SUNRISE. ON THE NEGATIVE SIDE...THE GROUND WILL HAVE SOME TIME TO
DRY OUT THIS AFTERNOON AS THERE WILL BE FULL SUNSHINE ACROSS THE
AREA.
WINDS TODAY WILL BE FROM THE NORTHEAST 5 TO 8 KNOTS THIS
AFTERNOON...THEN LIGHT TONIGHT AND BECOMING SOUTHWEST 7 TO 10 KNOTS
AFTER 15Z MONDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...CP
SHORT TERM...RYAN
LONG TERM....HOMANN/RYAN
AVIATION...JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
932 AM EST SUN FEB 5 2012
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
CLOUDS WILL DEPART EARLY THIS MORNING WITH FOG BURNING OFF THROUGH
THE MORNING AS HIGH PRESSURE BUILDS INTO CENTRAL INDIANA. THE HIGH
WILL BRING DRY WEATHER AND MAINLY CLEAR SKIES THROUGH TUESDAY. A
WEAK UPPER LEVEL DISTURBANCE WILL PROVIDE A CHANCE FOR LIGHT RAIN
AND SNOW TUESDAY NIGHT AND WEDNESDAY. THE EXPANSION OF A BROAD UPPER
LEVEL TROUGH WILL SIGNAL A SHIFT TO COLDER TEMPERATURES FOR LATE
WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
WITH VISIBILITIES AROUND HALF A MILE OR LESS AT TIMES IN THE
NORTHWEST COUNTIES AND BELOW FREEZING TEMPERATURES ADDED A
FREEZING FOG ADVISORY EARLIER THAT RUNS THROUGH 10 AM FOR THAT
AREA...WITH THE MAIN CONCERNS BEING VISIBILITY RESTRICTIONS FOR
TRAVELERS AS WELL AS SLICK SPOTS DEVELOPING ON UNTREATED
ROADWAYS...ESPECIALLY BRIDGES AND OVERPASSES. ALSO ADDED SOME
CLOUD COVER FOR THE MORNING ACROSS THE CENTRAL AND SOUTH BASED ON
SATELLITE LOOP...BUT THIS SHOULD BE DISSIPATING IN THE 10 AM TO
NOON TIMEFRAME. PREVIOUS DISCUSSION FOLLOWS...
LIGHT PRECIP AND DRIZZLE RAPIDLY DECREASING IN COVERAGE TO THE
SOUTHEAST OF THE INDY METRO EARLY THIS MORNING...AND EXPECT IT TO BE
CLEAR OF THE FORECAST AREA BY 09-10Z. BACK EDGE OF LOWER CLOUDS ALSO
RAPIDLY DROPPING SOUTH AS DRIER AIR SPREADS INTO THE LOWER GREAT
LAKES. TEMPS WERE HOVERING NEAR FREEZING ACROSS FAR NORTHERN
SECTIONS OF THE FORECAST AREA WHERE SKIES HAD ALREADY CLEARED...WITH
MID AND UPPER 30S ELSEWHERE AT 08Z.
PRIMARY CHALLENGES FOR TODAY FOCUS OVER THE NEXT SIX HOURS THROUGH
MID MORNING WITH RESPECT TO LOW CLOUD COVERAGE AND THE POSSIBILITY
OF FOG DEVELOPMENT AS SKIES CLEAR. MOS AND LAMP GUIDANCE NOT
CAPTURING THE RAPIDITY OF THE CLEARING VERY WELL AND EVEN THE MOST
RECENT RUC DATA SEEMS TO BE FALLING BEHIND A BIT WITH RESPECT TO THE
SOUTHWARD SURGE IN CLEARING SINCE MIDNIGHT. ALREADY AT 08Z CLEARING
LINE IS APPROACHING THE NORTHERN INDY SUBURBS. HOWEVER...BACK EDGE
OF THE STRATOCU NOT PROGRESSING SOUTH AS QUICKLY OVER FAR EASTERN
INDIANA AND WESTERN OHIO. WITH LIGHT NORTHEAST FLOW THROUGH THE
LOWER LEVELS...QUITE PLAUSIBLE THAT THIS MAY SLOW THE DEPARTURE OF
THE STRATOCU ALONG THE I-70 CORRIDOR UNTIL CLOSER TO DAYBREAK. FOR
NOW...WILL MAINTAIN CLOUDS SOUTH OF I-70 THROUGH DAYBREAK WITH CLEAR
SKIES TO THE NORTH. POTENTIAL FOR FOG DEVELOPMENT IS GREATER OVER
NORTHERN COUNTIES WITH THE CLEARING. POSSIBILITY DOES EXIST FOR
THICKER FOG TO IMPACT A FEW LOCATIONS OVER FAR NORTHERN COUNTIES BUT
OVERALL LIGHT NORTHERLY FLOW AND CONTINUED EXPANSION OF DRIER
AIRMASS FROM THE NORTH SHOULD KEEP THICKER FOG CONFINED TO LOCALIZED
AREAS. WILL CARRY PATCHY FOG NORTH OF I-70 INTO MID MORNING AND
ADJUST ACCORDINGLY AS NEEDED. CONTINUING A MENTION OF PATCHY
FREEZING FOG OVER FAR NORTHERN COUNTIES WHERE SURFACE TEMPS LIKELY
TO BOTTOM OUT AT 28-30 DEGREES.
REMAINDER OF THE DAY WILL BE QUIET AS SKIES BECOME SUNNY UNDER
STRONG HIGH PRESSURE RIDGE. MODEL SOUNDINGS SHOW DEEP SUBSIDENCE
TAKING HOLD WITH CLEAR SKIES AND LIGHT NORTHERLY FLOW EXPECTED FOR
THE REST OF THE DAY.
TEMPS...MOS GUIDANCE SUPPORTED BY LOW LEVEL THERMALS AS TEMPS SHOULD
WARM INTO THE MID AND UPPER 40S THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES TUESDAY NIGHT AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE REGION.
MUCH OF THE SHORT TERM WILL REMAIN TRANQUIL AS BROAD HIGH PRESSURE
RIDGE DOMINATES THE WEATHER PATTERN OVER THE OHIO VALLEY. MODEL
SOUNDINGS MAINTAIN DEEP SUBSIDENCE OVER CENTRAL INDIANA THROUGH
MONDAY NIGHT WHICH SHOULD KEEP SKIES LARGELY CLOUD-FREE. REMNANT
UPPER LEVEL FEATURE FROM SYSTEM THIS WEEKEND WILL PASS TO THE SOUTH
OF THE REGION WITH LITTLE FANFARE AS A RESULT. WEAK FRONTAL BOUNDARY
DROPS THROUGH THE FORECAST AREA LATE MONDAY NIGHT INTO TUESDAY BUT
WILL ONLY BRING A SUBTLE INCREASE IN HIGHER CLOUDS AS NO APPRECIABLE
MOISTURE IS PRESENT.
MODELS CONVERGING ON THE ARRIVAL OF ISENTROPIC LIFT AND MOISTURE
AHEAD OF A MID LEVEL SHORT WAVE TUESDAY NIGHT. WHILE TIMING OF THE
SHORT WAVE VARIES BETWEEN THE MODELS...INTRODUCTION OF LOW CHANCE
POPS FOR TUESDAY NIGHT APPEARS WARRANTED. ANALYSIS OF LOW LEVEL
THERMALS SUPPORT POTENTIAL OF A RA/SN MIX CHANGING PREDOMINANTLY
OVER TO LIGHT SNOW AS THE NIGHT PROGRESSES. AT THIS POINT...PRECIP
AMOUNTS LOOK LIMITED AT ONLY A COUPLE HUNDREDTHS WITH SNOW ACCUMS OF
A FEW TENTHS OF AN INCH AT BEST OVER NORTHERN COUNTIES.
TEMPS...LOW LEVEL THERMAL PROFILES SUPPORTED MOS GUIDANCE THROUGH
MUCH OF THE PERIOD. TEMPS ON MONDAY SHOULD BE A FEW DEGREES WARMER
THAN TODAY WITH ABUNDANT SUNSHINE AND SOUTHWEST FLOW DEVELOPING.
PASSAGE OF THE WEAK FRONT EARLY TUESDAY WILL SERVE TO KNOCK HIGHS
DOWN A FEW DEGREES TUESDAY...WITH COLDER AIR ARRIVING TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE MAIN FORECAST CHALLENGES FOR THE PERIOD ARE PRECIPITATION
CHANCES AND TEMPERATURES LATE IN THE PERIOD AS A DECENT PUSH OF
COLDER AIR SLIDES DOWN FROM CANADA.
THE MODELS ARE BEGINNING TO COME INTO AGREEMENT WITH THE TIMING OF
AN UPPER LEVEL WAVE PASSING THROUGH THE FORECAST AREA ON WEDNESDAY
WITH THE ECMWF JUST SLIGHTLY FASTER THAN THE GFS AND CANADIAN.
SUFFICIENT MOISTURE STILL LOOKS TO BE THE LIMITING FACTOR SO
STICKING WITH CHANCE POPS PROVIDED BY ALLBLEND SEEMS LIKE THE BEST
MOVE FOR NOW. ALSO INTRODUCED A SLIGHT CHANCE ACROSS THE EAST FOR
WEDNESDAY NIGHT TO ACCOUNT FOR THE SLIGHTLY SLOWER MODEL SOLUTIONS.
WITH TEMPERATURES CONTINUING TO BE AROUND NORMAL VALUES...LOWS IN
THE MID 20S AND HIGHS IN THE MID 30S...CONTINUED WITH A RAIN/SNOW
MIX IN THE GRIDS.
SURFACE HIGH PRESSURE WILL SLIDE ACROSS THE REGION ON THURSDAY. THIS
WILL CAUSE SOUTHWESTERLY WINDS TO RETURN ALLOWING TEMPERATURES TO
RISE TO ABOVE NORMAL VALUES ONCE AGAIN. HOWEVER...THE WARM UP WILL
BE SHORT LIVED AS A STRONG UPPER LOW NEAR HUDSON BAY TRANSPORTS A
MUCH COLDER AIRMASS TOWARDS CENTRAL INDIANA. DECREASED ALLBLEND
TEMPERATURES 2-3 DEGREES HEADING INTO THE WEEKEND WITH THE GFS
DEPICTING 850 MB TEMPERATURES APPROACHING -20 C.
&&
.AVIATION /DISCUSSION FOR THE 05/15Z KIND TAF UPDATE/...
SATELLITE SHOWS EXTENSIVE AREA OF BROKEN STRATUS ALONG AND EAST OF A
EYE-MIE LINE. BUT MUCH OF THIS IS THIN AND IT WILL NOT BE LONG
BEFORE IT STARTS CLEARING OUT. WILL KEEP IFR CEILINGS FOR ANOTHER
HOUR BEFORE RAPIDLY IMPROVING TO VFR AFTER THAT TIME. PREVIOUS
AVIATION DISCUSSION FOLLOWS...
CLOUDS HAVE HELD OVER KIND/KHUF/KBMG...SO THIS SHOULD PREVENT
CONDITIONS FROM DETERIORATING ANY LOWER THAN MVFR CATEGORY
THROUGH DAYBREAK AT THOSE SITES. HOWEVER...THE CLEARING AT KLAF
HAS CAUSED VISIBILITY RESTRICTIONS DUE TO FOG FORMATION.
SO...ANTICIPATE IFR CONDITIONS AT KLAF THROUGH DAYBREAK...BRIEF
MVFR CONDITIONS FROM SUN 14-15Z...AND THEN VFR CONDITIONS BY SUN
15/16Z.
AS SOON AS FOG LIFTS AND CEILINGS INCREASE AROUND MID
MORNING...FLYING CONDITIONS WILL BE GOOD AT ALL TAF SITES THROUGH
THE REMAINDER OF TAF PERIOD WITH VFR CONDITIONS.
WINDS WILL BE NORTHEASTERLY AT 5 TO 10 KTS THROUGH THIS AFTERNOON
AND WILL THEN BECOME WESTERLY LATE TONIGHT AT 3 TO 6 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR INZ021-
028>031-035-038.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/CP
SHORT TERM...RYAN
LONG TERM....HOMANN/RYAN
AVIATION...TDUD/JH
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
852 AM EST SUN FEB 5 2012
.UPDATE...
NEAR TERM SECTION UPDATED BELOW.
&&
.SYNOPSIS...
CLOUDS WILL DEPART EARLY THIS MORNING WITH FOG BURNING OFF THROUGH
THE MORNING AS HIGH PRESSURE BUILDS INTO CENTRAL INDIANA. THE HIGH
WILL BRING DRY WEATHER AND MAINLY CLEAR SKIES THROUGH TUESDAY. A
WEAK UPPER LEVEL DISTURBANCE WILL PROVIDE A CHANCE FOR LIGHT RAIN
AND SNOW TUESDAY NIGHT AND WEDNESDAY. THE EXPANSION OF A BROAD UPPER
LEVEL TROUGH WILL SIGNAL A SHIFT TO COLDER TEMPERATURES FOR LATE
WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
WITH VISIBILITIES AROUND HALF A MILE OR LESS AT TIMES IN THE
NORTHWEST COUNTIES AND BELOW FREEZING TEMPERATURES ADDED A
FREEZING FOG ADVISORY EARLIER THAT RUNS THROUGH 10 AM FOR THAT
AREA...WITH THE MAIN CONCERNS BEING VISIBILITY RESTRICTIONS FOR
TRAVELERS AS WELL AS SLICK SPOTS DEVELOPING ON UNTREATED
ROADWAYS...ESPECIALLY BRIDGES AND OVERPASSES. ALSO ADDED SOME
CLOUD COVER FOR THE MORNING ACROSS THE CENTRAL AND SOUTH BASED ON
SATELLITE LOOP...BUT THIS SHOULD BE DISSIPATING IN THE 10 AM TO
NOON TIMEFRAME. PREVIOUS DISCUSSION FOLLOWS...
LIGHT PRECIP AND DRIZZLE RAPIDLY DECREASING IN COVERAGE TO THE
SOUTHEAST OF THE INDY METRO EARLY THIS MORNING...AND EXPECT IT TO BE
CLEAR OF THE FORECAST AREA BY 09-10Z. BACK EDGE OF LOWER CLOUDS ALSO
RAPIDLY DROPPING SOUTH AS DRIER AIR SPREADS INTO THE LOWER GREAT
LAKES. TEMPS WERE HOVERING NEAR FREEZING ACROSS FAR NORTHERN
SECTIONS OF THE FORECAST AREA WHERE SKIES HAD ALREADY CLEARED...WITH
MID AND UPPER 30S ELSEWHERE AT 08Z.
PRIMARY CHALLENGES FOR TODAY FOCUS OVER THE NEXT SIX HOURS THROUGH
MID MORNING WITH RESPECT TO LOW CLOUD COVERAGE AND THE POSSIBILITY
OF FOG DEVELOPMENT AS SKIES CLEAR. MOS AND LAMP GUIDANCE NOT
CAPTURING THE RAPIDITY OF THE CLEARING VERY WELL AND EVEN THE MOST
RECENT RUC DATA SEEMS TO BE FALLING BEHIND A BIT WITH RESPECT TO THE
SOUTHWARD SURGE IN CLEARING SINCE MIDNIGHT. ALREADY AT 08Z CLEARING
LINE IS APPROACHING THE NORTHERN INDY SUBURBS. HOWEVER...BACK EDGE
OF THE STRATOCU NOT PROGRESSING SOUTH AS QUICKLY OVER FAR EASTERN
INDIANA AND WESTERN OHIO. WITH LIGHT NORTHEAST FLOW THROUGH THE
LOWER LEVELS...QUITE PLAUSIBLE THAT THIS MAY SLOW THE DEPARTURE OF
THE STRATOCU ALONG THE I-70 CORRIDOR UNTIL CLOSER TO DAYBREAK. FOR
NOW...WILL MAINTAIN CLOUDS SOUTH OF I-70 THROUGH DAYBREAK WITH CLEAR
SKIES TO THE NORTH. POTENTIAL FOR FOG DEVELOPMENT IS GREATER OVER
NORTHERN COUNTIES WITH THE CLEARING. POSSIBILITY DOES EXIST FOR
THICKER FOG TO IMPACT A FEW LOCATIONS OVER FAR NORTHERN COUNTIES BUT
OVERALL LIGHT NORTHERLY FLOW AND CONTINUED EXPANSION OF DRIER
AIRMASS FROM THE NORTH SHOULD KEEP THICKER FOG CONFINED TO LOCALIZED
AREAS. WILL CARRY PATCHY FOG NORTH OF I-70 INTO MID MORNING AND
ADJUST ACCORDINGLY AS NEEDED. CONTINUING A MENTION OF PATCHY
FREEZING FOG OVER FAR NORTHERN COUNTIES WHERE SURFACE TEMPS LIKELY
TO BOTTOM OUT AT 28-30 DEGREES.
REMAINDER OF THE DAY WILL BE QUIET AS SKIES BECOME SUNNY UNDER
STRONG HIGH PRESSURE RIDGE. MODEL SOUNDINGS SHOW DEEP SUBSIDENCE
TAKING HOLD WITH CLEAR SKIES AND LIGHT NORTHERLY FLOW EXPECTED FOR
THE REST OF THE DAY.
TEMPS...MOS GUIDANCE SUPPORTED BY LOW LEVEL THERMALS AS TEMPS SHOULD
WARM INTO THE MID AND UPPER 40S THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES TUESDAY NIGHT AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE REGION.
MUCH OF THE SHORT TERM WILL REMAIN TRANQUIL AS BROAD HIGH PRESSURE
RIDGE DOMINATES THE WEATHER PATTERN OVER THE OHIO VALLEY. MODEL
SOUNDINGS MAINTAIN DEEP SUBSIDENCE OVER CENTRAL INDIANA THROUGH
MONDAY NIGHT WHICH SHOULD KEEP SKIES LARGELY CLOUD-FREE. REMNANT
UPPER LEVEL FEATURE FROM SYSTEM THIS WEEKEND WILL PASS TO THE SOUTH
OF THE REGION WITH LITTLE FANFARE AS A RESULT. WEAK FRONTAL BOUNDARY
DROPS THROUGH THE FORECAST AREA LATE MONDAY NIGHT INTO TUESDAY BUT
WILL ONLY BRING A SUBTLE INCREASE IN HIGHER CLOUDS AS NO APPRECIABLE
MOISTURE IS PRESENT.
MODELS CONVERGING ON THE ARRIVAL OF ISENTROPIC LIFT AND MOISTURE
AHEAD OF A MID LEVEL SHORT WAVE TUESDAY NIGHT. WHILE TIMING OF THE
SHORT WAVE VARIES BETWEEN THE MODELS...INTRODUCTION OF LOW CHANCE
POPS FOR TUESDAY NIGHT APPEARS WARRANTED. ANALYSIS OF LOW LEVEL
THERMALS SUPPORT POTENTIAL OF A RA/SN MIX CHANGING PREDOMINANTLY
OVER TO LIGHT SNOW AS THE NIGHT PROGRESSES. AT THIS POINT...PRECIP
AMOUNTS LOOK LIMITED AT ONLY A COUPLE HUNDREDTHS WITH SNOW ACCUMS OF
A FEW TENTHS OF AN INCH AT BEST OVER NORTHERN COUNTIES.
TEMPS...LOW LEVEL THERMAL PROFILES SUPPORTED MOS GUIDANCE THROUGH
MUCH OF THE PERIOD. TEMPS ON MONDAY SHOULD BE A FEW DEGREES WARMER
THAN TODAY WITH ABUNDANT SUNSHINE AND SOUTHWEST FLOW DEVELOPING.
PASSAGE OF THE WEAK FRONT EARLY TUESDAY WILL SERVE TO KNOCK HIGHS
DOWN A FEW DEGREES TUESDAY...WITH COLDER AIR ARRIVING TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE MAIN FORECAST CHALLENGES FOR THE PERIOD ARE PRECIPITATION
CHANCES AND TEMPERATURES LATE IN THE PERIOD AS A DECENT PUSH OF
COLDER AIR SLIDES DOWN FROM CANADA.
THE MODELS ARE BEGINNING TO COME INTO AGREEMENT WITH THE TIMING OF
AN UPPER LEVEL WAVE PASSING THROUGH THE FORECAST AREA ON WEDNESDAY
WITH THE ECMWF JUST SLIGHTLY FASTER THAN THE GFS AND CANADIAN.
SUFFICIENT MOISTURE STILL LOOKS TO BE THE LIMITING FACTOR SO
STICKING WITH CHANCE POPS PROVIDED BY ALLBLEND SEEMS LIKE THE BEST
MOVE FOR NOW. ALSO INTRODUCED A SLIGHT CHANCE ACROSS THE EAST FOR
WEDNESDAY NIGHT TO ACCOUNT FOR THE SLIGHTLY SLOWER MODEL SOLUTIONS.
WITH TEMPERATURES CONTINUING TO BE AROUND NORMAL VALUES...LOWS IN
THE MID 20S AND HIGHS IN THE MID 30S...CONTINUED WITH A RAIN/SNOW
MIX IN THE GRIDS.
SURFACE HIGH PRESSURE WILL SLIDE ACROSS THE REGION ON THURSDAY. THIS
WILL CAUSE SOUTHWESTERLY WINDS TO RETURN ALLOWING TEMPERATURES TO
RISE TO ABOVE NORMAL VALUES ONCE AGAIN. HOWEVER...THE WARM UP WILL
BE SHORT LIVED AS A STRONG UPPER LOW NEAR HUDSON BAY TRANSPORTS A
MUCH COLDER AIRMASS TOWARDS CENTRAL INDIANA. DECREASED ALLBLEND
TEMPERATURES 2-3 DEGREES HEADING INTO THE WEEKEND WITH THE GFS
DEPICTING 850 MB TEMPERATURES APPROACHING -20 C.
&&
.AVIATION /DISCUSSION FOR THE 05/12Z TAF ISSUANCE/...
CLOUDS HAVE HELD OVER KIND/KHUF/KBMG...SO THIS SHOULD PREVENT
CONDITIONS FROM DETERIORATING ANY LOWER THAN MVFR CATEGORY
THROUGH DAYBREAK AT THOSE SITES. HOWEVER...THE CLEARING AT KLAF
HAS CAUSED VISIBILITY RESTRICTIONS DUE TO FOG FORMATION.
SO...ANTICIPATE IFR CONDITIONS AT KLAF THROUGH DAYBREAK...BRIEF
MVFR CONDITIONS FROM SUN 14-15Z...AND THEN VFR CONDITIONS BY SUN
15/16Z.
AS SOON AS FOG LIFTS AND CEILINGS INCREASE AROUND MID
MORNING...FLYING CONDITIONS WILL BE GOOD AT ALL TAF SITES THROUGH
THE REMAINDER OF TAF PERIOD WITH VFR CONDITIONS.
WINDS WILL BE NORTHEASTERLY AT 5 TO 10 KTS THROUGH THIS AFTERNOON
AND WILL THEN BECOME WESTERLY LATE TONIGHT AT 3 TO 6 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR INZ021-
028>031-035-038.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN/CP
SHORT TERM...RYAN
LONG TERM....HOMANN/RYAN
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
642 AM EST SUN FEB 5 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
CLOUDS WILL DEPART EARLY THIS MORNING WITH FOG BURNING OFF THROUGH
THE MORNING AS HIGH PRESSURE BUILDS INTO CENTRAL INDIANA. THE HIGH
WILL BRING DRY WEATHER AND MAINLY CLEAR SKIES THROUGH TUESDAY. A
WEAK UPPER LEVEL DISTURBANCE WILL PROVIDE A CHANCE FOR LIGHT RAIN
AND SNOW TUESDAY NIGHT AND WEDNESDAY. THE EXPANSION OF A BROAD UPPER
LEVEL TROUGH WILL SIGNAL A SHIFT TO COLDER TEMPERATURES FOR LATE
WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
LIGHT PRECIP AND DRIZZLE RAPIDLY DECREASING IN COVERAGE TO THE
SOUTHEAST OF THE INDY METRO EARLY THIS MORNING...AND EXPECT IT TO BE
CLEAR OF THE FORECAST AREA BY 09-10Z. BACK EDGE OF LOWER CLOUDS ALSO
RAPIDLY DROPPING SOUTH AS DRIER AIR SPREADS INTO THE LOWER GREAT
LAKES. TEMPS WERE HOVERING NEAR FREEZING ACROSS FAR NORTHERN
SECTIONS OF THE FORECAST AREA WHERE SKIES HAD ALREADY CLEARED...WITH
MID AND UPPER 30S ELSEWHERE AT 08Z.
PRIMARY CHALLENGES FOR TODAY FOCUS OVER THE NEXT SIX HOURS THROUGH
MID MORNING WITH RESPECT TO LOW CLOUD COVERAGE AND THE POSSIBILITY
OF FOG DEVELOPMENT AS SKIES CLEAR. MOS AND LAMP GUIDANCE NOT
CAPTURING THE RAPIDITY OF THE CLEARING VERY WELL AND EVEN THE MOST
RECENT RUC DATA SEEMS TO BE FALLING BEHIND A BIT WITH RESPECT TO THE
SOUTHWARD SURGE IN CLEARING SINCE MIDNIGHT. ALREADY AT 08Z CLEARING
LINE IS APPROACHING THE NORTHERN INDY SUBURBS. HOWEVER...BACK EDGE
OF THE STRATOCU NOT PROGRESSING SOUTH AS QUICKLY OVER FAR EASTERN
INDIANA AND WESTERN OHIO. WITH LIGHT NORTHEAST FLOW THROUGH THE
LOWER LEVELS...QUITE PLAUSIBLE THAT THIS MAY SLOW THE DEPARTURE OF
THE STRATOCU ALONG THE I-70 CORRIDOR UNTIL CLOSER TO DAYBREAK. FOR
NOW...WILL MAINTAIN CLOUDS SOUTH OF I-70 THROUGH DAYBREAK WITH CLEAR
SKIES TO THE NORTH. POTENTIAL FOR FOG DEVELOPMENT IS GREATER OVER
NORTHERN COUNTIES WITH THE CLEARING. POSSIBILITY DOES EXIST FOR
THICKER FOG TO IMPACT A FEW LOCATIONS OVER FAR NORTHERN COUNTIES BUT
OVERALL LIGHT NORTHERLY FLOW AND CONTINUED EXPANSION OF DRIER
AIRMASS FROM THE NORTH SHOULD KEEP THICKER FOG CONFINED TO LOCALIZED
AREAS. WILL CARRY PATCHY FOG NORTH OF I-70 INTO MID MORNING AND
ADJUST ACCORDINGLY AS NEEDED. CONTINUING A MENTION OF PATCHY
FREEZING FOG OVER FAR NORTHERN COUNTIES WHERE SURFACE TEMPS LIKELY
TO BOTTOM OUT AT 28-30 DEGREES.
REMAINDER OF THE DAY WILL BE QUIET AS SKIES BECOME SUNNY UNDER
STRONG HIGH PRESSURE RIDGE. MODEL SOUNDINGS SHOW DEEP SUBSIDENCE
TAKING HOLD WITH CLEAR SKIES AND LIGHT NORTHERLY FLOW EXPECTED FOR
THE REST OF THE DAY.
TEMPS...MOS GUIDANCE SUPPORTED BY LOW LEVEL THERMALS AS TEMPS SHOULD
WARM INTO THE MID AND UPPER 40S THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES TUESDAY NIGHT AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE REGION.
MUCH OF THE SHORT TERM WILL REMAIN TRANQUIL AS BROAD HIGH PRESSURE
RIDGE DOMINATES THE WEATHER PATTERN OVER THE OHIO VALLEY. MODEL
SOUNDINGS MAINTAIN DEEP SUBSIDENCE OVER CENTRAL INDIANA THROUGH
MONDAY NIGHT WHICH SHOULD KEEP SKIES LARGELY CLOUD-FREE. REMNANT
UPPER LEVEL FEATURE FROM SYSTEM THIS WEEKEND WILL PASS TO THE SOUTH
OF THE REGION WITH LITTLE FANFARE AS A RESULT. WEAK FRONTAL BOUNDARY
DROPS THROUGH THE FORECAST AREA LATE MONDAY NIGHT INTO TUESDAY BUT
WILL ONLY BRING A SUBTLE INCREASE IN HIGHER CLOUDS AS NO APPRECIABLE
MOISTURE IS PRESENT.
MODELS CONVERGING ON THE ARRIVAL OF ISENTROPIC LIFT AND MOISTURE
AHEAD OF A MID LEVEL SHORT WAVE TUESDAY NIGHT. WHILE TIMING OF THE
SHORT WAVE VARIES BETWEEN THE MODELS...INTRODUCTION OF LOW CHANCE
POPS FOR TUESDAY NIGHT APPEARS WARRANTED. ANALYSIS OF LOW LEVEL
THERMALS SUPPORT POTENTIAL OF A RA/SN MIX CHANGING PREDOMINANTLY
OVER TO LIGHT SNOW AS THE NIGHT PROGRESSES. AT THIS POINT...PRECIP
AMOUNTS LOOK LIMITED AT ONLY A COUPLE HUNDREDTHS WITH SNOW ACCUMS OF
A FEW TENTHS OF AN INCH AT BEST OVER NORTHERN COUNTIES.
TEMPS...LOW LEVEL THERMAL PROFILES SUPPORTED MOS GUIDANCE THROUGH
MUCH OF THE PERIOD. TEMPS ON MONDAY SHOULD BE A FEW DEGREES WARMER
THAN TODAY WITH ABUNDANT SUNSHINE AND SOUTHWEST FLOW DEVELOPING.
PASSAGE OF THE WEAK FRONT EARLY TUESDAY WILL SERVE TO KNOCK HIGHS
DOWN A FEW DEGREES TUESDAY...WITH COLDER AIR ARRIVING TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE MAIN FORECAST CHALLENGES FOR THE PERIOD ARE PRECIPITATION
CHANCES AND TEMPERATURES LATE IN THE PERIOD AS A DECENT PUSH OF
COLDER AIR SLIDES DOWN FROM CANADA.
THE MODELS ARE BEGINNING TO COME INTO AGREEMENT WITH THE TIMING OF
AN UPPER LEVEL WAVE PASSING THROUGH THE FORECAST AREA ON WEDNESDAY
WITH THE ECMWF JUST SLIGHTLY FASTER THAN THE GFS AND CANADIAN.
SUFFICIENT MOISTURE STILL LOOKS TO BE THE LIMITING FACTOR SO
STICKING WITH CHANCE POPS PROVIDED BY ALLBLEND SEEMS LIKE THE BEST
MOVE FOR NOW. ALSO INTRODUCED A SLIGHT CHANCE ACROSS THE EAST FOR
WEDNESDAY NIGHT TO ACCOUNT FOR THE SLIGHTLY SLOWER MODEL SOLUTIONS.
WITH TEMPERATURES CONTINUING TO BE AROUND NORMAL VALUES...LOWS IN
THE MID 20S AND HIGHS IN THE MID 30S...CONTINUED WITH A RAIN/SNOW
MIX IN THE GRIDS.
SURFACE HIGH PRESSURE WILL SLIDE ACROSS THE REGION ON THURSDAY. THIS
WILL CAUSE SOUTHWESTERLY WINDS TO RETURN ALLOWING TEMPERATURES TO
RISE TO ABOVE NORMAL VALUES ONCE AGAIN. HOWEVER...THE WARM UP WILL
BE SHORT LIVED AS A STRONG UPPER LOW NEAR HUDSON BAY TRANSPORTS A
MUCH COLDER AIRMASS TOWARDS CENTRAL INDIANA. DECREASED ALLBLEND
TEMPERATURES 2-3 DEGREES HEADING INTO THE WEEKEND WITH THE GFS
DEPICTING 850 MB TEMPERATURES APPROACHING -20 C.
&&
.AVIATION /DISCUSSION FOR THE 05/12Z TAF ISSUANCE/...
CLOUDS HAVE HELD OVER KIND/KHUF/KBMG...SO THIS SHOULD PREVENT
CONDITIONS FROM DETERIORATING ANY LOWER THAN MVFR CATEGORY
THROUGH DAYBREAK AT THOSE SITES. HOWEVER...THE CLEARING AT KLAF
HAS CAUSED VISIBILITY RESTRICTIONS DUE TO FOG FORMATION.
SO...ANTICIPATE IFR CONDITIONS AT KLAF THROUGH DAYBREAK...BRIEF
MVFR CONDITIONS FROM SUN 14-15Z...AND THEN VFR CONDITIONS BY SUN
15/16Z.
AS SOON AS FOG LIFTS AND CEILINGS INCREASE AROUND MID
MORNING...FLYING CONDITIONS WILL BE GOOD AT ALL TAF SITES THROUGH
THE REMAINDER OF TAF PERIOD WITH VFR CONDITIONS.
WINDS WILL BE NORTHEASTERLY AT 5 TO 10 KTS THROUGH THIS AFTERNOON
AND WILL THEN BECOME WESTERLY LATE TONIGHT AT 3 TO 6 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....HOMANN/RYAN
AVIATION...TDUD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
354 AM EST SUN FEB 5 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
CLOUDS WILL DEPART EARLY THIS MORNING WITH FOG BURNING OFF THROUGH
THE MORNING AS HIGH PRESSURE BUILDS INTO CENTRAL INDIANA. THE HIGH
WILL BRING DRY WEATHER AND MAINLY CLEAR SKIES THROUGH TUESDAY. A
WEAK UPPER LEVEL DISTURBANCE WILL PROVIDE A CHANCE FOR LIGHT RAIN
AND SNOW TUESDAY NIGHT AND WEDNESDAY. THE EXPANSION OF A BROAD UPPER
LEVEL TROUGH WILL SIGNAL A SHIFT TO COLDER TEMPERATURES FOR LATE
WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
LIGHT PRECIP AND DRIZZLE RAPIDLY DECREASING IN COVERAGE TO THE
SOUTHEAST OF THE INDY METRO EARLY THIS MORNING...AND EXPECT IT TO BE
CLEAR OF THE FORECAST AREA BY 09-10Z. BACK EDGE OF LOWER CLOUDS ALSO
RAPIDLY DROPPING SOUTH AS DRIER AIR SPREADS INTO THE LOWER GREAT
LAKES. TEMPS WERE HOVERING NEAR FREEZING ACROSS FAR NORTHERN
SECTIONS OF THE FORECAST AREA WHERE SKIES HAD ALREADY CLEARED...WITH
MID AND UPPER 30S ELSEWHERE AT 08Z.
PRIMARY CHALLENGES FOR TODAY FOCUS OVER THE NEXT SIX HOURS THROUGH
MID MORNING WITH RESPECT TO LOW CLOUD COVERAGE AND THE POSSIBILITY
OF FOG DEVELOPMENT AS SKIES CLEAR. MOS AND LAMP GUIDANCE NOT
CAPTURING THE RAPIDITY OF THE CLEARING VERY WELL AND EVEN THE MOST
RECENT RUC DATA SEEMS TO BE FALLING BEHIND A BIT WITH RESPECT TO THE
SOUTHWARD SURGE IN CLEARING SINCE MIDNIGHT. ALREADY AT 08Z CLEARING
LINE IS APPROACHING THE NORTHERN INDY SUBURBS. HOWEVER...BACK EDGE
OF THE STRATOCU NOT PROGRESSING SOUTH AS QUICKLY OVER FAR EASTERN
INDIANA AND WESTERN OHIO. WITH LIGHT NORTHEAST FLOW THROUGH THE
LOWER LEVELS...QUITE PLAUSIBLE THAT THIS MAY SLOW THE DEPARTURE OF
THE STRATOCU ALONG THE I-70 CORRIDOR UNTIL CLOSER TO DAYBREAK. FOR
NOW...WILL MAINTAIN CLOUDS SOUTH OF I-70 THROUGH DAYBREAK WITH CLEAR
SKIES TO THE NORTH. POTENTIAL FOR FOG DEVELOPMENT IS GREATER OVER
NORTHERN COUNTIES WITH THE CLEARING. POSSIBILITY DOES EXIST FOR
THICKER FOG TO IMPACT A FEW LOCATIONS OVER FAR NORTHERN COUNTIES BUT
OVERALL LIGHT NORTHERLY FLOW AND CONTINUED EXPANSION OF DRIER
AIRMASS FROM THE NORTH SHOULD KEEP THICKER FOG CONFINED TO LOCALIZED
AREAS. WILL CARRY PATCHY FOG NORTH OF I-70 INTO MID MORNING AND
ADJUST ACCORDINGLY AS NEEDED. CONTINUING A MENTION OF PATCHY
FREEZING FOG OVER FAR NORTHERN COUNTIES WHERE SURFACE TEMPS LIKELY
TO BOTTOM OUT AT 28-30 DEGREES.
REMAINDER OF THE DAY WILL BE QUIET AS SKIES BECOME SUNNY UNDER
STRONG HIGH PRESSURE RIDGE. MODEL SOUNDINGS SHOW DEEP SUBSIDENCE
TAKING HOLD WITH CLEAR SKIES AND LIGHT NORTHERLY FLOW EXPECTED FOR
THE REST OF THE DAY.
TEMPS...MOS GUIDANCE SUPPORTED BY LOW LEVEL THERMALS AS TEMPS SHOULD
WARM INTO THE MID AND UPPER 40S THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES TUESDAY NIGHT AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE REGION.
MUCH OF THE SHORT TERM WILL REMAIN TRANQUIL AS BROAD HIGH PRESSURE
RIDGE DOMINATES THE WEATHER PATTERN OVER THE OHIO VALLEY. MODEL
SOUNDINGS MAINTAIN DEEP SUBSIDENCE OVER CENTRAL INDIANA THROUGH
MONDAY NIGHT WHICH SHOULD KEEP SKIES LARGELY CLOUD-FREE. REMNANT
UPPER LEVEL FEATURE FROM SYSTEM THIS WEEKEND WILL PASS TO THE SOUTH
OF THE REGION WITH LITTLE FANFARE AS A RESULT. WEAK FRONTAL BOUNDARY
DROPS THROUGH THE FORECAST AREA LATE MONDAY NIGHT INTO TUESDAY BUT
WILL ONLY BRING A SUBTLE INCREASE IN HIGHER CLOUDS AS NO APPRECIABLE
MOISTURE IS PRESENT.
MODELS CONVERGING ON THE ARRIVAL OF ISENTROPIC LIFT AND MOISTURE
AHEAD OF A MID LEVEL SHORT WAVE TUESDAY NIGHT. WHILE TIMING OF THE
SHORT WAVE VARIES BETWEEN THE MODELS...INTRODUCTION OF LOW CHANCE
POPS FOR TUESDAY NIGHT APPEARS WARRANTED. ANALYSIS OF LOW LEVEL
THERMALS SUPPORT POTENTIAL OF A RA/SN MIX CHANGING PREDOMINANTLY
OVER TO LIGHT SNOW AS THE NIGHT PROGRESSES. AT THIS POINT...PRECIP
AMOUNTS LOOK LIMITED AT ONLY A COUPLE HUNDREDTHS WITH SNOW ACCUMS OF
A FEW TENTHS OF AN INCH AT BEST OVER NORTHERN COUNTIES.
TEMPS...LOW LEVEL THERMAL PROFILES SUPPORTED MOS GUIDANCE THROUGH
MUCH OF THE PERIOD. TEMPS ON MONDAY SHOULD BE A FEW DEGREES WARMER
THAN TODAY WITH ABUNDANT SUNSHINE AND SOUTHWEST FLOW DEVELOPING.
PASSAGE OF THE WEAK FRONT EARLY TUESDAY WILL SERVE TO KNOCK HIGHS
DOWN A FEW DEGREES TUESDAY...WITH COLDER AIR ARRIVING TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE MAIN FORECAST CHALLENGES FOR THE PERIOD ARE PRECIPITATION
CHANCES AND TEMPERATURES LATE IN THE PERIOD AS A DECENT PUSH OF
COLDER AIR SLIDES DOWN FROM CANADA.
THE MODELS ARE BEGINNING TO COME INTO AGREEMENT WITH THE TIMING OF
AN UPPER LEVEL WAVE PASSING THROUGH THE FORECAST AREA ON WEDNESDAY
WITH THE ECMWF JUST SLIGHTLY FASTER THAN THE GFS AND CANADIAN.
SUFFICIENT MOISTURE STILL LOOKS TO BE THE LIMITING FACTOR SO
STICKING WITH CHANCE POPS PROVIDED BY ALLBLEND SEEMS LIKE THE BEST
MOVE FOR NOW. ALSO INTRODUCED A SLIGHT CHANCE ACROSS THE EAST FOR
WEDNESDAY NIGHT TO ACCOUNT FOR THE SLIGHTLY SLOWER MODEL SOLUTIONS.
WITH TEMPERATURES CONTINUING TO BE AROUND NORMAL VALUES...LOWS IN
THE MID 20S AND HIGHS IN THE MID 30S...CONTINUED WITH A RAIN/SNOW
MIX IN THE GRIDS.
SURFACE HIGH PRESSURE WILL SLIDE ACROSS THE REGION ON THURSDAY. THIS
WILL CAUSE SOUTHWESTERLY WINDS TO RETURN ALLOWING TEMPERATURES TO
RISE TO ABOVE NORMAL VALUES ONCE AGAIN. HOWEVER...THE WARM UP WILL
BE SHORT LIVED AS A STRONG UPPER LOW NEAR HUDSON BAY TRANSPORTS A
MUCH COLDER AIRMASS TOWARDS CENTRAL INDIANA. DECREASED ALLBLEND
TEMPERATURES 2-3 DEGREES HEADING INTO THE WEEKEND WITH THE GFS
DEPICTING 850 MB TEMPERATURES APPROACHING -20 C.
&&
.AVIATION /DISCUSSION FOR THE 05/09Z TAF UPDATE/...
UPDATE...
THE NEXT FEW HOURS CONTINUE TO BE THE CRITICAL TIME FRAME FOR FOG
DEVELOPMENT AT KIND. CLEARING HAS ALREADY TAKEN PLACE AT
KLAF...AND THE LINE IS CURRENTLY JUST TO THE NORTH OF KIND.
HOWEVER...VISIBILITIES HAVE NOT DROPPED DRASTICALLY AT KLAF OVER
THE LAST FEW HOURS WITH CLEAR SKIES...SO WILL BASE KIND ON THAT
TREND FOR NOW. SO...ALL INDICATIONS AT THIS TIME ARE LEADING TO
MVFR CONDITIONS THROUGH DAYBREAK...AND CONTINUED IMPROVEMENT
AFTER THAT.
PREVIOUS DISCUSSION...
RESTRICTIONS LIKELY IN SOME FORM THROUGH THE MORNING
HOURS...IMPROVING TO VFR THEREAFTER.
QUESTION IS WHERE CLEARING WILL OCCUR AND FOG WILL DEVELOP. LAF MOST
LIKELY TO SEE CLEARING...BUT IND CANNOT BE RULED OUT. 10-12Z WILL BE
THE MOST CRITICAL TIME FRAME AT IND. IF MOISTURE SCOURS OUT ENOUGH
TO CLEAR...DENSE FOG COULD BE POSSIBLE. AS IT LOOKS NOW...EXPECTING
IFR LOW CLOUD TO CONTINUE THROUGH THE MORNING WITH MAINLY MVFR
VISIBILITIES.
WINDS WILL GO FROM EAST/NORTHEASTERLY TO MORE NORTHERLY
OVERNIGHT...BUT SPEEDS SHOULD GENERALLY REMAIN LESS THAN 10KT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....HOMANN/RYAN
AVIATION...NIELD/TDUD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
334 AM EST SUN FEB 5 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
CLOUDS WILL DEPART EARLY THIS MORNING WITH FOG BURNING OFF THROUGH
THE MORNING AS HIGH PRESSURE BUILDS INTO CENTRAL INDIANA. THE HIGH
WILL BRING DRY WEATHER AND MAINLY CLEAR SKIES THROUGH TUESDAY. A
WEAK UPPER LEVEL DISTURBANCE WILL PROVIDE A CHANCE FOR LIGHT RAIN
AND SNOW TUESDAY NIGHT AND WEDNESDAY. THE EXPANSION OF A BROAD UPPER
LEVEL TROUGH WILL SIGNAL A SHIFT TO COLDER TEMPERATURES FOR LATE
WEEK AND INTO NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
LIGHT PRECIP AND DRIZZLE RAPIDLY DECREASING IN COVERAGE TO THE
SOUTHEAST OF THE INDY METRO EARLY THIS MORNING...AND EXPECT IT TO BE
CLEAR OF THE FORECAST AREA BY 09-10Z. BACK EDGE OF LOWER CLOUDS ALSO
RAPIDLY DROPPING SOUTH AS DRIER AIR SPREADS INTO THE LOWER GREAT
LAKES. TEMPS WERE HOVERING NEAR FREEZING ACROSS FAR NORTHERN
SECTIONS OF THE FORECAST AREA WHERE SKIES HAD ALREADY CLEARED...WITH
MID AND UPPER 30S ELSEWHERE AT 08Z.
PRIMARY CHALLENGES FOR TODAY FOCUS OVER THE NEXT SIX HOURS THROUGH
MID MORNING WITH RESPECT TO LOW CLOUD COVERAGE AND THE POSSIBILITY
OF FOG DEVELOPMENT AS SKIES CLEAR. MOS AND LAMP GUIDANCE NOT
CAPTURING THE RAPIDITY OF THE CLEARING VERY WELL AND EVEN THE MOST
RECENT RUC DATA SEEMS TO BE FALLING BEHIND A BIT WITH RESPECT TO THE
SOUTHWARD SURGE IN CLEARING SINCE MIDNIGHT. ALREADY AT 08Z CLEARING
LINE IS APPROACHING THE NORTHERN INDY SUBURBS. HOWEVER...BACK EDGE
OF THE STRATOCU NOT PROGRESSING SOUTH AS QUICKLY OVER FAR EASTERN
INDIANA AND WESTERN OHIO. WITH LIGHT NORTHEAST FLOW THROUGH THE
LOWER LEVELS...QUITE PLAUSIBLE THAT THIS MAY SLOW THE DEPARTURE OF
THE STRATOCU ALONG THE I-70 CORRIDOR UNTIL CLOSER TO DAYBREAK. FOR
NOW...WILL MAINTAIN CLOUDS SOUTH OF I-70 THROUGH DAYBREAK WITH CLEAR
SKIES TO THE NORTH. POTENTIAL FOR FOG DEVELOPMENT IS GREATER OVER
NORTHERN COUNTIES WITH THE CLEARING. POSSIBILITY DOES EXIST FOR
THICKER FOG TO IMPACT A FEW LOCATIONS OVER FAR NORTHERN COUNTIES BUT
OVERALL LIGHT NORTHERLY FLOW AND CONTINUED EXPANSION OF DRIER
AIRMASS FROM THE NORTH SHOULD KEEP THICKER FOG CONFINED TO LOCALIZED
AREAS. WILL CARRY PATCHY FOG NORTH OF I-70 INTO MID MORNING AND
ADJUST ACCORDINGLY AS NEEDED. CONTINUING A MENTION OF PATCHY
FREEZING FOG OVER FAR NORTHERN COUNTIES WHERE SURFACE TEMPS LIKELY
TO BOTTOM OUT AT 28-30 DEGREES.
REMAINDER OF THE DAY WILL BE QUIET AS SKIES BECOME SUNNY UNDER
STRONG HIGH PRESSURE RIDGE. MODEL SOUNDINGS SHOW DEEP SUBSIDENCE
TAKING HOLD WITH CLEAR SKIES AND LIGHT NORTHERLY FLOW EXPECTED FOR
THE REST OF THE DAY.
TEMPS...MOS GUIDANCE SUPPORTED BY LOW LEVEL THERMALS AS TEMPS SHOULD
WARM INTO THE MID AND UPPER 40S THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
FORECAST CHALLENGES FOCUS ON PRECIP CHANCES TUESDAY NIGHT AS AN
UPPER LEVEL DISTURBANCE MOVES INTO THE REGION.
MUCH OF THE SHORT TERM WILL REMAIN TRANQUIL AS BROAD HIGH PRESSURE
RIDGE DOMINATES THE WEATHER PATTERN OVER THE OHIO VALLEY. MODEL
SOUNDINGS MAINTAIN DEEP SUBSIDENCE OVER CENTRAL INDIANA THROUGH
MONDAY NIGHT WHICH SHOULD KEEP SKIES LARGELY CLOUD-FREE. REMNANT
UPPER LEVEL FEATURE FROM SYSTEM THIS WEEKEND WILL PASS TO THE SOUTH
OF THE REGION WITH LITTLE FANFARE AS A RESULT. WEAK FRONTAL BOUNDARY
DROPS THROUGH THE FORECAST AREA LATE MONDAY NIGHT INTO TUESDAY BUT
WILL ONLY BRING A SUBTLE INCREASE IN HIGHER CLOUDS AS NO APPRECIABLE
MOISTURE IS PRESENT.
MODELS CONVERGING ON THE ARRIVAL OF ISENTROPIC LIFT AND MOISTURE
AHEAD OF A MID LEVEL SHORT WAVE TUESDAY NIGHT. WHILE TIMING OF THE
SHORT WAVE VARIES BETWEEN THE MODELS...INTRODUCTION OF LOW CHANCE
POPS FOR TUESDAY NIGHT APPEARS WARRANTED. ANALYSIS OF LOW LEVEL
THERMALS SUPPORT POTENTIAL OF A RA/SN MIX CHANGING PREDOMINANTLY
OVER TO LIGHT SNOW AS THE NIGHT PROGRESSES. AT THIS POINT...PRECIP
AMOUNTS LOOK LIMITED AT ONLY A COUPLE HUNDREDTHS WITH SNOW ACCUMS OF
A FEW TENTHS OF AN INCH AT BEST OVER NORTHERN COUNTIES.
TEMPS...LOW LEVEL THERMAL PROFILES SUPPORTED MOS GUIDANCE THROUGH
MUCH OF THE PERIOD. TEMPS ON MONDAY SHOULD BE A FEW DEGREES WARMER
THAN TODAY WITH ABUNDANT SUNSHINE AND SOUTHWEST FLOW DEVELOPING.
PASSAGE OF THE WEAK FRONT EARLY TUESDAY WILL SERVE TO KNOCK HIGHS
DOWN A FEW DEGREES TUESDAY...WITH COLDER AIR ARRIVING TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE MAIN FORECAST CHALLENGES FOR THE PERIOD ARE PRECIPITATION
CHANCES AND TEMPERATURES LATE IN THE PERIOD AS A DECENT PUSH OF
COLDER AIR SLIDES DOWN FROM CANADA.
THE MODELS ARE BEGINNING TO COME INTO AGREEMENT WITH THE TIMING OF
AN UPPER LEVEL WAVE PASSING THROUGH THE FORECAST AREA ON WEDNESDAY
WITH THE ECMWF JUST SLIGHTLY FASTER THAN THE GFS AND CANADIAN.
SUFFICIENT MOISTURE STILL LOOKS TO BE THE LIMITING FACTOR SO
STICKING WITH CHANCE POPS PROVIDED BY ALLBLEND SEEMS LIKE THE BEST
MOVE FOR NOW. ALSO INTRODUCED A SLIGHT CHANCE ACROSS THE EAST FOR
WEDNESDAY NIGHT TO ACCOUNT FOR THE SLIGHTLY SLOWER MODEL SOLUTIONS.
WITH TEMPERATURES CONTINUING TO BE AROUND NORMAL VALUES...LOWS IN
THE MID 20S AND HIGHS IN THE MID 30S...CONTINUED WITH A RAIN/SNOW
MIX IN THE GRIDS.
SURFACE HIGH PRESSURE WILL SLIDE ACROSS THE REGION ON THURSDAY. THIS
WILL CAUSE SOUTHWESTERLY WINDS TO RETURN ALLOWING TEMPERATURES TO
RISE TO ABOVE NORMAL VALUES ONCE AGAIN. HOWEVER...THE WARM UP WILL
BE SHORT LIVED AS A STRONG UPPER LOW NEAR HUDSON BAY TRANSPORTS A
MUCH COLDER AIRMASS TOWARDS CENTRAL INDIANA. DECREASED ALLBLEND
TEMPERATURES 2-3 DEGREES HEADING INTO THE WEEKEND WITH THE GFS
DEPICTING 850 MB TEMPERATURES APPROACHING -20 C.
&&
.AVIATION /DISCUSSION FOR THE 05/06Z TAFS/...
RESTRICTIONS LIKELY IN SOME FORM THROUGH THE MORNING
HOURS...IMPROVING TO VFR THEREAFTER.
QUESTION IS WHERE CLEARING WILL OCCUR AND FOG WILL DEVELOP. LAF MOST
LIKELY TO SEE CLEARING...BUT IND CANNOT BE RULED OUT. 10-12Z WILL BE
THE MOST CRITICAL TIME FRAME AT IND. IF MOISTURE SCOURS OUT ENOUGH
TO CLEAR...DENSE FOG COULD BE POSSIBLE. AS IT LOOKS NOW...EXPECTING
IFR LOW CLOUD TO CONTINUE THROUGH THE MORNING WITH MAINLY MVFR
VISIBILITIES.
WINDS WILL GO FROM EAST/NORTHEASTERLY TO MORE NORTHERLY
OVERNIGHT...BUT SPEEDS SHOULD GENERALLY REMAIN LESS THAN 10KT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...RYAN
NEAR TERM...RYAN
SHORT TERM...RYAN
LONG TERM....HOMANN/RYAN
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
309 PM CST SUN FEB 5 2012
.SYNOPSIS...
STRATUS HAS BEEN THE MAIN FOCUS OF THE DAY...WITH STRATUS EXTENDING
FROM SOUTHEAST MINNESOTA AND WESTERN WISCONSIN...NEARLY ALL OF
IOWA...AND EXTENDING BACK INTO EASTERN NEBRASKA. IT HAS MAINLY
AFFECTED THE WESTERN HALF OF THE FORECAST AREA...WITH AREAS ALONG
AND EAST OF THE MISSISSIPPI RIVER MOSTLY IN THE CLEAR. THIS STRATUS
IS TRAPPED UNDER A STRONG SURFACE HIGH PRESSURE WHICH IS CENTERED
OVER KANSAS....WITH A BROAD RIDGE EXTENDING NORTHEAST UP OVER IOWA
AND EXTENDING UP INTO WISCONSIN. SOUNDINGS FROM THIS MORNING...
AIRCRAFT REPORTS AND AIRCRAFT SOUNDINGS FROM THE AREA TODAY INDICATE
THAT WE HAVE A SATURATED LAYER AROUND 950MB...GENERALLY ABOUT 1000
TO 1500 FEET THICK DEPENDING ON THE LOCATION...WITH A STEEP
INVERSION JUST ABOVE IT. AT UPPER LEVELS THE UPPER LEVEL LOW THAT
PRODUCED RAIN AND SNOW YESTERDAY OVER IOWA IS NOW SHIFTING RAPIDLY
SOUTH ACROSS MISSOURI. CLOUDS...BUT LITTLE RAIN IS CONTINUING TO
AFFECT SOUTHERN MISSOURI AND INTO KENTUCKY AND TENNESSEE. ..LE..
&&
.SHORT TERM...TONIGHT AND MONDAY...
STRATUS REMAINS THE MAIN FORECAST CHALLENGE. THE LARGE SCALE MODELS
WE ARE USED TO DEPENDING UPON HAVE NOT EVEN INITIALIZED THE LOW
LEVEL MOISTURE ASSOCIATED WITH THE STRATUS CORRECTLY. THUS...THESE
MODELS ARE OF LITTLE USE IN PREDICTING IT. OF THE MESOSCALE
MODELS...ONLY THE HRRR SEEMS TO HAVE ANY SORT OF HANDLE ON THE
STATUS OF THE STRATUS. THUS...BETWEEN IT...EXPERIENCE AND
NOWCASTING TECHNIQES ARE ABOUT THE ONLY DECENT FORECAST TOOLS
TODAY. SINCE THE MOISTURE IS TRAPPED BENEATH THE SURFACE RIDGE
AXIS...ANTICIPATE THE STRATUS SHOULD REFORM AND SPREAD BACK
SOUTHEAST AGAIN THIS EVENING...ADVECTING ALONG IN THE NORTHWEST
925MB FLOW. OVER THE DAKOTAS TODAY THINGS SEEM TO HAVE CLEARED
NICELY WHERE THESE WINDS TURNED WESTERLY AND THE DOWNSLOPE COMPONENT
COULD HELP ACT TO DRY AND WARM THIS LAYER...HELPING TO DISSIPATE THE
CLOUDS. HOWEVER...DOWNSLOPE WILL NOT HELP US THIS FAR EAST AND THOUGH I
EXPECT THE 925MB WINDS TO TURN WESTERLY FOR US AFTER MIDNIGHT
TONIGHT THE STRATUS SHOULD LINGER THROUGH THE OVERNIGHT HOURS. UNDER
THE STRATUS LAST NIGHT MIN TEMPS ONLY DROPPED INTO THE MID TO UPPER
20S...SO HAVE CONTINUED THIS.
MONDAY MORNING AND AFTERNOON LOOKS LIKE OUR BEST OPPORTUNITY FOR
CLEARING OUT THIS BAND OF STRATUS. THE WESTERLY 925MB FLOW
STRENGTHENS TO 925MB...SOME WARM AIR ADVECTION AT THAT LAYER SHOULD
HELP TO DISSIPATE IT...ALONG WITH SHEER BODILY ADVECTION. IT IS
NOTORIOUSLY HARD TO GET RID OF STRATUS THIS TIME OF YEAR...BUT THAT
IS USUALLY DUE TO ESTABLISHED SNOWCOVER. HOPEFULLY WITH THE SNOW
GONE FOR OUR AREA WE CAN GET RID OF THE STRATUS SOONER.
ANTICIPATING MORE CLOUD COVER OVER THE EAST HAVE KEPT MAX TEMPS
THERE COOLER...BUT NOT AS COOL AS THE NORTHWEST IS TODAY.
OTHERWISE...40-45 IS NOT UNREASONABLE AS LONG AS WE CLEAR BY EARLY
AFTERNOON. ..LE..
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY...
FORECAST FOCUS ON POTENTIAL FOR FLURRIES MONDAY NIGHT AND TUESDAY
OTHERWISE MAINLY A DRY PERIOD. BRIEF SHOT OF ARCTIC AIR AT THE END
OF THE NEW WORK WEEK.
MONDAY NIGHT AND TUESDAY...COLD FRONT TO ARRIVE MONDAY NIGHT WITH
POTENTIAL FOR SOME FLURRIES OR BRIEF LIGHT SNOW. EXTENSIVE LOW
STRATUS TO DEVELOP BEHIND THE FRONT AS WE COLD ADVECT MONDAY NIGHT
WITH LOW CLOUDS CONTINUING ON TUESDAY AS SURFACE WINDS TURN
NORTHEAST. WILL CONTINUE WITH SLIGHT CHANCE POPS IN OUR SOUTH BUT
EVEN THE ECM HAS BACKED OFF ON QPF AMOUNTS. TEMPERATURES ON TUESDAY
ONLY COOL DOWN TO NEAR NORMAL FOR EARLY FEBRUARY. MAXIMUM
TEMPERATURES EXPECTED TO BE IN THE 30S.
TUESDAY NIGHT THROUGH THURSDAY...EXTENSIVE LOW STRATUS TO REMAIN
TUESDAY NIGHT AND FOR MOST OF WEDNESDAY WITH FORECAST SOUNDINGS
INDICATING NORTHEAST LOW LEVEL WINDS. WILL TRY TO CLEAR THE SKIES
OUT BY WEDNESDAY NIGHT AS WINDS TURN WEST TO SOUTHWEST. MAX TEMPS
ABOUT NORMAL WITH HIGHS IN THE 30S TO NEAR 40.
THURSDAY NIGHT THROUGH SATURDAY NIGHT...TROUGH STRONGLY DIGS INTO
THE MIDWEST/GREAT LAKES TIED TO A DEEP LOW NEAR HUDSON BAY. THIS
SENDS AN ARCTIC FRONT SWEEPING RAPIDLY THROUGH THE DVN CWA THURSDAY
NIGHT. HOWEVER DUE TO THE LACK OF SIGNIFICANT SNOW COVER TO OUR
NORTH AND NO SNOW COVER IN THE DVN CWA THIS AIRMASS WILL BE MODIFIED
BY THE TIME IT GETS HERE. THE COLDEST DAY WILL BE FRIDAY BUT
SATURDAY WONT EXACTLY BE A PICNIC EITHER. HIGHS WILL BE IN THE MID
20S NORTH TO LOWER 30S SOUTH WITH LOWS MAINLY IN THE TEENS. WARM
ADVECTION ALREADY UNDERWAY BY SATURDAY NIGHT AS ARCTIC HIGH PRESSURE
SHIFTS INTO THE OHIO VALLEY RETURNING SOUTH WINDS TO THE REGION.
SUNDAY...NICE WARM-UP BEGINS AS UPPER LEVEL FLOW BECOMES ZONAL TO
SOUTHWEST WITH SOUTHWEST SURFACE WINDS. MAX TEMPS SHOULD PUSH WELL
INTO THE 30S NORTH TO LOWER 40S SOUTH. EVEN WARMER TEMPERATURES
EARLY NEXT WEEK.
..HAASE..
&&
.AVIATION... /ISSUED 1214 PM CST SUN FEB 5 2012/
LARGE AREA STRATUS AND FOG WITH IFR TO LIFR CONDITIONS WAS
CONTINUING TO AFFECT MUCH OF IOWA. THIS STRATUS IS TRAPPED
UNDERNEATH A STRONG HIGH PRESSURE RIDGE OVER THE CENTRAL PLAINS.
IT WILL GRADUALLY SHIFT SOUTHEAST TODAY AND TONIGHT. THE EASTWARD
PROGRESS OF THE STRATUS HAS STALLED OR SLOWED DOWN...AND EXPECT A
CERTAIN AMOUNT OF RETREAT THIS AFTERNOON AS THE SUNSHINE WORKS TO
DISSIPATE IT. IT ALSO HELPS THAT THE STRATUS IS THIN...LATEST
PIREPS INDICATE THAT CLOUD TOPS ARE AROUND 1500 FT AGL. KDBQ...
KMLI AND KBRL SHOULD REMAIN NEAR THE EDGE OF THE STRATUS AND HAVE
INCLUDED TEMPOS GROUPS FOR THIS AFTERNOON. KCID IS LIKELY TO
REMAIN IFR IN THE STRATUS...BUT HAVE GONE OPTIMISTIC WITH A SHORT
TEMPO GROUP FOR VFR AS WELL. NEAR SUNSET EXPECT THE STRATUS TO
EXPAND AGAIN...AND CONDITIONS WILL DETERIORATE BACK TO IFR OR EVEN
LIFR FOR MOST OF THE NIGHT. THE SURFACE RIDGE FINALLY SHIFTS EAST OF
THE AREA MONDAY MORNING...AND EXPECT THE STRATUS TO FINALLY MOVE
OUT BY 14-16Z AND LEAVE US WITH VFR CONDITIONS. WINDS THROUGH
PERIOD TO REMAIN LIGHT...BUT WILL BE LIGHT NORTH THIS AFTERNOON
AND GRADUALLY SWITCH TO WEST LATE TONIGHT AND EARLY MONDAY
MORNING. ..LE..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
LE/HAASE
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1155 AM CST SUN FEB 5 2012
.SHORT TERM /TODAY/...
WIDESPREAD STRATUS FIELD CURRENTLY PUSHING SOUTH THOUGH NORTHERN IA
EARLY THIS MORNING AND REPRESENTS THE FORECAST CHALLENGE OF THE DAY.
THE STRATUS HAS BE SHIFTING SOUTH AT 16 KTS THE PAST FEW HOURS. THIS
WOULD BRING IT TO THE MISSOURI BORDER AROUND 16Z. THE HRRR HAS
INITIALIZED THE CLOUD PROGRESSION WELL AND SUGGESTS THEY WILL STICK
AROUND MOST OF THE DAY. IF ANY EROSION DOES OCCUR...IT WILL BE ON
THE OUTSIDE EDGES AND THIS WOULD LEAVE CENTRAL IA THE LAST TO
DISSIPATE. WITH NEW SNOW PACK OVER THE SOUTH...LIGHT WINDS AND LACK
OF STRONG SUBSIDENCE...FAVOR THE CLOUDY SOLUTION. THE LACK OF SUN
WILL RESULT IN BELOW GUIDANCE HIGHS TODAY. EXPECT SOME FOG EARLY IN
THE PERIOD AND THE POSSIBILITY REMAINS OF LOCALLY DENSE FOG. BEST
POTENTIAL WILL BE SOUTH OF HIGHWAY 30 AS THE HIGHER DEWPOINTS
ASSOCIATED WITH THE STRATUS SETTLES OVER THE NEW SNOW PACK WHERE
CONDITIONS HAVE ALREADY RADIATED.
.LONG TERM /TONIGHT THROUGH SATURDAY/...
OVERALL MID/LONG RANGE REMAINS RELATIVELY QUIET THROUGH THE
PERIOD...WITH MAINLY DRY CONDITIONS. ISSUE TONIGHT INTO
MONDAY...WILL BE IF STRATUS MOVING INTO THE CWA...WILL LINGER INTO
TONIGHT ACROSS THE AREA/BREAKUP/OR POSSIBLY EVEN REDEVELOP.
STRATUS/FOG HAS BEEN QUITE PERSISTENT ACROSS THE AREAS EAST OF THE
SFC HIGH PRES RIDGE SITUATED ACROSS THE CENTRAL DAKOTAS INTO NE/KS
THE PAST FEW DAYS...THEREFORE EXPECT THIS TREND TO CONTINUE TONIGHT.
THEREFORE HAVE INCREASED CLOUD COVER ACROSS THE SOUTHERN CWA
TONIGHT...AND ADDED IN A MENTION OF FOG AS HIGHER MOISTURE AIR
REMAINS IN PLACE OVER NEW SNOWPACK. OTHERWISE AS WINDS BECOME MORE
WESTERLY TO SOUTHWESTERLY AHEAD OF THE NEXT SYSTEM...EXPECT
CLOUDS/FOG TO ERODE ACROSS THE AREA MONDAY. TWO SYSTEMS OF NOTE
MONDAY INTO MONDAY NIGHT...WITH UPPER LEVEL SPLIT FLOW REGIME IN
PLACE. ONE STRENGTHENING UPPER LOW SITUATED ALONG THE FRONT RANGE OF
THE ROCKIES TUESDAY...EXPECTED TO SLIDE EAST INTO TUESDAY. ANOTHER
UPPER LEVEL SHORTWAVE DROPPING SOUTHEASTWARD FROM SASK/ALBERTA
THROUGH THE DAKOTAS/MN. THESE SYSTEMS TO MERGE OVER THE AREA TUESDAY
INTO TUESDAY NIGHT BRINGING INCREASING CLOUDS...AND POSSIBLY A
CHANCE FOR SOME LIGHT SNOW ACROSS THE SOUTHERN CWA. MAJORITY OF
PRECIPITATION EXPECTED TO FALL SOUTH OF IOWA...BUT SOUNDINGS TRY TO
SATURATE A BIT WITH WEAK LIFT ALONG AND SOUTH OF I-80. THEREFORE DID
EXPAND COVERAGE OF SLIGHT CHANCE POPS TO INCLUDE SOUTHERN HALF OF
CWA FOR TUESDAY...WITH THE SYSTEM QUICKLY SLIDING EAST/SOUTHEASTWARD
TUESDAY NIGHT WITH MAYBE SOME LINGERING SNOW ACROSS THE FAR
SOUTHEAST. OTHERWISE CAA EXPECTED THROUGHOUT THE DAY WITH
CLOUDS...SO EXPECT AN EARLY MAX TEMP WITH STEADY OR FALLING TEMPS
THROUGH THE REMAINDER OF THE DAY. HIGH PRESSURE TO BUILD INTO THE
AREA FOR WEDNESDAY...WITH BROAD UPPER LEVEL TROUGHING STILL EXPECTED
TO DIG SOUTHWARD ACROSS THE CENTRAL/EASTERN US FOR LATE IN THE WEEK.
THIS WILL BRING A COLD FROM SWEEPING THROUGH THE CWA
THURSDAY...SENDING H85 TEMPS INTO THE TEENS BELOW ZERO CELSIUS.
HOWEVER CANADIAN/GFS/PREVIOUS EC MUCH MORE AGGRESSIVE WITH THE SURGE
OF COLD AIR PLUNGING IT MUCH FURTHER SOUTH AND ALLOWING THIS ARCTIC
AIRMASS TO REMAIN IN PLACE ACROSS THE CWA FOR THE WEEKEND. LATEST
00Z EC IS MUCH DIFFERENT...KIND OF BRUSHING THE CWA WITH THE ARCTIC
AIRMASS AND THEN QUICKLY MODERATING THE TEMPS WITH WEAK UPPER
RIDGING INTO THE WEEKEND. THEREFORE SOME UNCERTAINTY WITH TEMPS
TOWARD THE END OF THE PERIOD...SO STUCK NEAR THE CONSALL GUIDANCE
GRIDS...WITH SOME TRENDING TOWARD THE COLDER SOLUTION DUE TO BETTER
CONTINUITY IN THE PAST FEW RUNS.
&&
.AVIATION...05/18Z
WIDESPREAD LIFR CONDITIONS IN STRATUS AND/OR FOG ACROSS IA LATE THIS
MORNING...ALTHOUGH GRADUAL IMPROVEMENT TO SPOTTY IFR IS OCCURRING.
THESE CLOUD TRENDS WILL BE THE BIGGEST CONCERN THROUGH THE
PERIOD...AND CONFIDENCE IS RATHER LOW. EROSION IS STARTING TO TAKE
PLACE ALONG SD/MN BORDER BUT QUESTION IS WHETHER THIS WILL BE
AGGRESSIVE ENOUGH TO REACH TAF SITES. HAVE CONTINUED PREVIOUS
THINKING KEEPING CIGS NO BETTER THAN IFR INTO MON MORNING...BUT
OUTCOMES ON EITHER END OF THAT CATEGORY ARE CERTAINLY POSSIBLE.
IMPROVEMENT IS MORE LIKELY NORTH /KFOD/KMCW/KALO/ WITH SOUTHERN
SITES IN FRESH SNOW COVER /DSM/KOTM/ MORE APT TO MIX LESS AND
STAY IN THE STRATUS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...DONAVON
LONG TERM...BEERENDS
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
544 AM CST SUN FEB 5 2012
...UPDATED FOR THE 12Z AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
WIDESPREAD STRATUS FIELD CURRENTLY PUSHING SOUTH THOUGH NORTHERN IA
EARLY THIS MORNING AND REPRESENTS THE FORECAST CHALLENGE OF THE DAY.
THE STRATUS HAS BE SHIFTING SOUTH AT 16 KTS THE PAST FEW HOURS. THIS
WOULD BRING IT TO THE MISSOURI BORDER AROUND 16Z. THE HRRR HAS
INITIALIZED THE CLOUD PROGRESSION WELL AND SUGGESTS THEY WILL STICK
AROUND MOST OF THE DAY. IF ANY EROSION DOES OCCUR...IT WILL BE ON
THE OUTSIDE EDGES AND THIS WOULD LEAVE CENTRAL IA THE LAST TO
DISSIPATE. WITH NEW SNOW PACK OVER THE SOUTH...LIGHT WINDS AND LACK
OF STRONG SUBSIDENCE...FAVOR THE CLOUDY SOLUTION. THE LACK OF SUN
WILL RESULT IN BELOW GUIDANCE HIGHS TODAY. EXPECT SOME FOG EARLY IN
THE PERIOD AND THE POSSIBILITY REMAINS OF LOCALLY DENSE FOG. BEST
POTENTIAL WILL BE SOUTH OF HIGHWAY 30 AS THE HIGHER DEWPOINTS
ASSOCIATED WITH THE STRATUS SETTLES OVER THE NEW SNOW PACK WHERE
CONDITIONS HAVE ALREADY RADIATED.
.LONG TERM /TONIGHT THROUGH SATURDAY/...
OVERALL MID/LONG RANGE REMAINS RELATIVELY QUIET THROUGH THE
PERIOD...WITH MAINLY DRY CONDITIONS. ISSUE TONIGHT INTO
MONDAY...WILL BE IF STRATUS MOVING INTO THE CWA...WILL LINGER INTO
TONIGHT ACROSS THE AREA/BREAKUP/OR POSSIBLY EVEN REDEVELOP.
STRATUS/FOG HAS BEEN QUITE PERSISTENT ACROSS THE AREAS EAST OF THE
SFC HIGH PRES RIDGE SITUATED ACROSS THE CENTRAL DAKOTAS INTO NE/KS
THE PAST FEW DAYS...THEREFORE EXPECT THIS TREND TO CONTINUE TONIGHT.
THEREFORE HAVE INCREASED CLOUD COVER ACROSS THE SOUTHERN CWA
TONIGHT...AND ADDED IN A MENTION OF FOG AS HIGHER MOISTURE AIR
REMAINS IN PLACE OVER NEW SNOWPACK. OTHERWISE AS WINDS BECOME MORE
WESTERLY TO SOUTHWESTERLY AHEAD OF THE NEXT SYSTEM...EXPECT
CLOUDS/FOG TO ERODE ACROSS THE AREA MONDAY. TWO SYSTEMS OF NOTE
MONDAY INTO MONDAY NIGHT...WITH UPPER LEVEL SPLIT FLOW REGIME IN
PLACE. ONE STRENGTHENING UPPER LOW SITUATED ALONG THE FRONT RANGE OF
THE ROCKIES TUESDAY...EXPECTED TO SLIDE EAST INTO TUESDAY. ANOTHER
UPPER LEVEL SHORTWAVE DROPPING SOUTHEASTWARD FROM SASK/ALBERTA
THROUGH THE DAKOTAS/MN. THESE SYSTEMS TO MERGE OVER THE AREA TUESDAY
INTO TUESDAY NIGHT BRINGING INCREASING CLOUDS...AND POSSIBLY A
CHANCE FOR SOME LIGHT SNOW ACROSS THE SOUTHERN CWA. MAJORITY OF
PRECIPITATION EXPECTED TO FALL SOUTH OF IOWA...BUT SOUNDINGS TRY TO
SATURATE A BIT WITH WEAK LIFT ALONG AND SOUTH OF I-80. THEREFORE DID
EXPAND COVERAGE OF SLIGHT CHANCE POPS TO INCLUDE SOUTHERN HALF OF
CWA FOR TUESDAY...WITH THE SYSTEM QUICKLY SLIDING EAST/SOUTHEASTWARD
TUESDAY NIGHT WITH MAYBE SOME LINGERING SNOW ACROSS THE FAR
SOUTHEAST. OTHERWISE CAA EXPECTED THROUGHOUT THE DAY WITH
CLOUDS...SO EXPECT AN EARLY MAX TEMP WITH STEADY OR FALLING TEMPS
THROUGH THE REMAINDER OF THE DAY. HIGH PRESSURE TO BUILD INTO THE
AREA FOR WEDNESDAY...WITH BROAD UPPER LEVEL TROUGHING STILL EXPECTED
TO DIG SOUTHWARD ACROSS THE CENTRAL/EASTERN US FOR LATE IN THE WEEK.
THIS WILL BRING A COLD FROM SWEEPING THROUGH THE CWA
THURSDAY...SENDING H85 TEMPS INTO THE TEENS BELOW ZERO CELSIUS.
HOWEVER CANADIAN/GFS/PREVIOUS EC MUCH MORE AGGRESSIVE WITH THE SURGE
OF COLD AIR PLUNGING IT MUCH FURTHER SOUTH AND ALLOWING THIS ARCTIC
AIRMASS TO REMAIN IN PLACE ACROSS THE CWA FOR THE WEEKEND. LATEST
00Z EC IS MUCH DIFFERENT...KIND OF BRUSHING THE CWA WITH THE ARCTIC
AIRMASS AND THEN QUICKLY MODERATING THE TEMPS WITH WEAK UPPER
RIDGING INTO THE WEEKEND. THEREFORE SOME UNCERTAINTY WITH TEMPS
TOWARD THE END OF THE PERIOD...SO STUCK NEAR THE CONSALL GUIDANCE
GRIDS...WITH SOME TRENDING TOWARD THE COLDER SOLUTION DUE TO BETTER
CONTINUITY IN THE PAST FEW RUNS.
&&
.AVIATION...05/12Z
LIFR STRATUS DECK MOVING THROUGH THE REGION TODAY IS THE AVIATION
CONCERN THROUGH THE PERIOD. EXPECT THE DECK TO GRADUALLY LIFT TO IFR
WITH IMPROVING VSBYS LATE THIS MORNING INTO THE AFTERNOON. VERY
LIKELY THE CIGS WILL MAINTAIN THROUGH THE REMAINDER OF THE DAY
THOUGH SOME EROSION ON THE OUTER EDGES IS POSSIBLE. STEERING FLOW
WILL BECOME MORE WESTERLY OVERNIGHT. THIS WILL HELP DRIVE THE
STRATUS SLOWLY EAST...HOWEVER BY EVENING THE STRATUS MAY BEGIN TO
EXPAND AGAIN WITH CIGS LOWERING BACK TO LIFR ALONG WITH AREAS OF FOG
REDEVELOPING.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
SHORT TERM...DONAVON
LONG TERM...BEERENDS
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS DES MOINES IA
310 PM CST SUN FEB 5 2012
.SHORT TERM /TODAY/...
WIDESPREAD STRATUS FIELD CURRENTLY PUSHING SOUTH THOUGH NORTHERN IA
EARLY THIS MORNING AND REPRESENTS THE FORECAST CHALLENGE OF THE DAY.
THE STRATUS HAS BE SHIFTING SOUTH AT 16 KTS THE PAST FEW HOURS. THIS
WOULD BRING IT TO THE MISSOURI BORDER AROUND 16Z. THE HRRR HAS
INITIALIZED THE CLOUD PROGRESSION WELL AND SUGGESTS THEY WILL STICK
AROUND MOST OF THE DAY. IF ANY EROSION DOES OCCUR...IT WILL BE ON
THE OUTSIDE EDGES AND THIS WOULD LEAVE CENTRAL IA THE LAST TO
DISSIPATE. WITH NEW SNOW PACK OVER THE SOUTH...LIGHT WINDS AND LACK
OF STRONG SUBSIDENCE...FAVOR THE CLOUDY SOLUTION. THE LACK OF SUN
WILL RESULT IN BELOW GUIDANCE HIGHS TODAY. EXPECT SOME FOG EARLY IN
THE PERIOD AND THE POSSIBILITY REMAINS OF LOCALLY DENSE FOG. BEST
POTENTIAL WILL BE SOUTH OF HIGHWAY 30 AS THE HIGHER DEWPOINTS
ASSOCIATED WITH THE STRATUS SETTLES OVER THE NEW SNOW PACK WHERE
CONDITIONS HAVE ALREADY RADIATED.
.LONG TERM /TONIGHT THROUGH SATURDAY/...
OVERALL MID/LONG RANGE REMAINS RELATIVELY QUIET THROUGH THE
PERIOD...WITH MAINLY DRY CONDITIONS. ISSUE TONIGHT INTO
MONDAY...WILL BE IF STRATUS MOVING INTO THE CWA...WILL LINGER INTO
TONIGHT ACROSS THE AREA/BREAKUP/OR POSSIBLY EVEN REDEVELOP.
STRATUS/FOG HAS BEEN QUITE PERSISTENT ACROSS THE AREAS EAST OF THE
SFC HIGH PRES RIDGE SITUATED ACROSS THE CENTRAL DAKOTAS INTO NE/KS
THE PAST FEW DAYS...THEREFORE EXPECT THIS TREND TO CONTINUE TONIGHT.
THEREFORE HAVE INCREASED CLOUD COVER ACROSS THE SOUTHERN CWA
TONIGHT...AND ADDED IN A MENTION OF FOG AS HIGHER MOISTURE AIR
REMAINS IN PLACE OVER NEW SNOWPACK. OTHERWISE AS WINDS BECOME MORE
WESTERLY TO SOUTHWESTERLY AHEAD OF THE NEXT SYSTEM...EXPECT
CLOUDS/FOG TO ERODE ACROSS THE AREA MONDAY. TWO SYSTEMS OF NOTE
MONDAY INTO MONDAY NIGHT...WITH UPPER LEVEL SPLIT FLOW REGIME IN
PLACE. ONE STRENGTHENING UPPER LOW SITUATED ALONG THE FRONT RANGE OF
THE ROCKIES TUESDAY...EXPECTED TO SLIDE EAST INTO TUESDAY. ANOTHER
UPPER LEVEL SHORTWAVE DROPPING SOUTHEASTWARD FROM SASK/ALBERTA
THROUGH THE DAKOTAS/MN. THESE SYSTEMS TO MERGE OVER THE AREA TUESDAY
INTO TUESDAY NIGHT BRINGING INCREASING CLOUDS...AND POSSIBLY A
CHANCE FOR SOME LIGHT SNOW ACROSS THE SOUTHERN CWA. MAJORITY OF
PRECIPITATION EXPECTED TO FALL SOUTH OF IOWA...BUT SOUNDINGS TRY TO
SATURATE A BIT WITH WEAK LIFT ALONG AND SOUTH OF I-80. THEREFORE DID
EXPAND COVERAGE OF SLIGHT CHANCE POPS TO INCLUDE SOUTHERN HALF OF
CWA FOR TUESDAY...WITH THE SYSTEM QUICKLY SLIDING EAST/SOUTHEASTWARD
TUESDAY NIGHT WITH MAYBE SOME LINGERING SNOW ACROSS THE FAR
SOUTHEAST. OTHERWISE CAA EXPECTED THROUGHOUT THE DAY WITH
CLOUDS...SO EXPECT AN EARLY MAX TEMP WITH STEADY OR FALLING TEMPS
THROUGH THE REMAINDER OF THE DAY. HIGH PRESSURE TO BUILD INTO THE
AREA FOR WEDNESDAY...WITH BROAD UPPER LEVEL TROUGHING STILL EXPECTED
TO DIG SOUTHWARD ACROSS THE CENTRAL/EASTERN US FOR LATE IN THE WEEK.
THIS WILL BRING A COLD FROM SWEEPING THROUGH THE CWA
THURSDAY...SENDING H85 TEMPS INTO THE TEENS BELOW ZERO CELSIUS.
HOWEVER CANADIAN/GFS/PREVIOUS EC MUCH MORE AGGRESSIVE WITH THE SURGE
OF COLD AIR PLUNGING IT MUCH FURTHER SOUTH AND ALLOWING THIS ARCTIC
AIRMASS TO REMAIN IN PLACE ACROSS THE CWA FOR THE WEEKEND. LATEST
00Z EC IS MUCH DIFFERENT...KIND OF BRUSHING THE CWA WITH THE ARCTIC
AIRMASS AND THEN QUICKLY MODERATING THE TEMPS WITH WEAK UPPER
RIDGING INTO THE WEEKEND. THEREFORE SOME UNCERTAINTY WITH TEMPS
TOWARD THE END OF THE PERIOD...SO STUCK NEAR THE CONSALL GUIDANCE
GRIDS...WITH SOME TRENDING TOWARD THE COLDER SOLUTION DUE TO BETTER
CONTINUITY IN THE PAST FEW RUNS.
&&
.AVIATION...05/06Z
LARGE AREA OF STRATUS DROPPING SOUTH FROM MN NOW AND SOLID OVC003
WALL OF CLOUDS HEADING INTO THE AREA. ALREADY NEAR KMCW BY 06Z AND
EXPECTED TO HEAD TOWARD US 20 BY 08-09Z AT KALO AND KFOD. BY 12Z THE
AREA OF LOWER CLOUDS AND VSBY SHOULD BE NEARING KDSM AND THEN
BETWEEN 16-18Z FOR KOTM. WARM AIR ADVECTION ALOFT FROM THE NORTHERN
PLAINS AND SOUTHERN CANADA MAY ACT TO KEEP STRATUS GOING MOST OF THE
DAY ESPECIALLY GIVEN THE COLDER SFC TEMPS ACROSS MOST OF OUR AREA
NOW. WITH NEW SNOW PACK FROM I80 SOUTH TO BORDER...THIS AREA MIGHT
BE SUSCEPTIBLE TO THICK FOG DEVELOPMENT EITHER OVERNIGHT OR ON
SUNDAY AS WELL. NEXT FEW DAYS MAY THE REGION WILL HAVE ADDED
CHALLENGE OF BOUNDARY LAYER MOISTURE AND POSSIBLE ISSUES WITH FOG.
DIFFICULT TO TIME...BUT ONCE IT SETS UP...IT MAY STICK AROUND UNTIL
STRONGER SFC WINDS RETURN MONDAY NIGHT OR TUESDAY. HAVE PASSED
DETAILS ALONG TO NIGHT SHIFT FOR NEXT PACKAGE. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
SHORT TERM...DONAVON
LONG TERM...BEERENDS
AVIATION...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1133 PM CST SAT FEB 4 2012
.UPDATE 05/06Z AVIATION DISCUSSION...
.SHORT TERM /TONIGHT/...
REMAINDER OF WARNINGS/ADVISORIES HAVE BEEN CANCELLED. STORM NOW
SOUTH OF AREA AND CONDITIONS CONTINUE TO IMPROVE.
CONTINUE TO TRIM BACK ADVISORY. EASTERN AREAS OF LIGHT SNOW NEARLY
OVER AND SOUTHWEST CONTINUES LIGHT. WARNING AREA STILL RECEIVING
SOME ADDITIONAL LIGHT SNOW. ALL WILL EXPIRE AT 06Z. NEXT ISSUE IS
FOG AND LOW STRATUS. EXPECTING LOW STRATUS AND FOG TO OVERTAKE
NORTHERN BORDER COUNTIES NEAR MN BORDER BY 06Z AND TRANSLATE SOUTH
TO NEAR DES MOINES BY 12Z. HAVE ADDED AREAS FOG NORTH AND MAINTAIN
PATCHY FOG SOUTH. IF SKIES CLEAR AND FOG GETS A FOOTHOLD...MAY BE
SOME DENSE FOG. DIFFICULT TO DECIDE WHAT AREAS MIGHT BE AT RISK FOR
THAT...GIVEN APPROACHING CLOUDS. UPSTREAM VSBYS LAST NIGHT WERE AT
OR ABOVE 1/2SM SO...MIGHT NOT BE A MAJOR ISSUE WITH THE EXCEPTION OF
FROSTY ROAD SURFACES. WILL NEED TO MONITOR THROUGH THE NIGHT.
HAVE TRIMMED BACK WINTER STORM WARNING WITH THE EXCEPTION OF WHERE
SNOW STILL FALLING IN SW IA. LEAVING ADVISORY AS IS...DUE TO BAND OF
SNOW STILL OCCURRING IN DEF ZONE OVER THE SOUTHEAST. MONITORING AREA
FOR FOG DEVELOPMENT LATE TONIGHT. ADVECTION FOG OVER MN AND
POTENTIAL FOR RADIATION FOG OVER IOWA MAY COMPLICATE TRAVEL
OVERNIGHT AND EARLY SUNDAY MORNING.
.PREVIOUS SHORT TERM /TONIGHT/...
PRIMARY CONCERNS REMAIN SNOW TRENDS. RADAR AND SATELLITE
OBSERVATIONS INDICATE THAT PRECIP INTENSITY IS BEGINNING TO WANE
WITH TOPS WARMING AND ECHOES DIMINISHING. MODELS CONFIRM THIS AS
WELL WITH 18Z RUC UVM AND MOISTURE BOTH DECREASING IN DENDRITIC
GROWTH ZONE AROUND H6/H5 OR 300K ISENT SURFACE. THIS THINKING HAS
LEAD TO CATEGORICAL POPS WITH LITTLE ADDITIONAL ACCUMULATION THROUGH
00Z...FOLLOWED BY FURTHER DECREASE IN POPS AND NORTH TO SOUTH
COVERAGE LATER THIS EVENING. MOST LOCAL VISIBILITIES ARE NOW 1SM OR
GREATER. HEADLINES WERE TRIMMED TO 06Z THIS AFTERNOON AND COULD
VERY WELL NEED TO BE CANCELLED EVEN EARLIER THIS EVENING IF TRENDS
CONTINUE.
NEXT CONCERN TURNS TO CONDITIONS OVERNIGHT. VERY SHALLOW STRATUS
AND FOG WAS MAKING HEADWAY SOUTH EARLIER THIS AFTERNOON BUT THAT HAS
NOW ERODED. LOW LEVEL WINDS WILL LIKELY BE JUST STRONG ENOUGH TO
PRECLUDE WIDESPREAD DENSE FOG. HOWEVER 21Z SURFACE ANALYSIS SHOWS
LACK OF MUCH DRYING UPSTREAM SO HAVE MENTIONED PATCHY FOG FOR A
START IN CASE THIS MOISTURE AREA DOES INDEED FILL BACK IN AGAIN.
.LONG TERM /SUNDAY THROUGH FRIDAY/...
LOW WILL HAVE PUSHED FURTHER EAST FOR BEGINNING OF PERIOD...WITH
HIGH PRESSURE PUSHING IN. HAVE INCLUDED MENTION FOR FOG ACROSS THE
NORTH EARLY SUNDAY MORNING...AND SHOULD LIFT BY LATE MORNING.
COULD AGAIN SEE FOG EARLY MONDAY...BUT NOT ENOUGH CONFIDENCE TO
INCLUDE MENTION ATTM. LOW OVER ROCKIES WILL DEEPEN...AND REMAIN
OVER ROCKIES THROUGH TUESDAY WITH SPLIT FLOW OVER REGION.
TEMPERATURES WILL WARM INTO MONDAY WITH WAA AND WEAK RIDGING OVER
IOWA.
STRONG WAVE WILL PUSH LOW OUT OF ROCKIES TUESDAY. THIS WILL BRING
A CHANCE FOR PRECIPITATION ACROSS IOWA. MODELS DO NOT HAVE GOOD RUN-
TO-RUN CONSISTENCY WITH TRACK OF LOW...BUT ARE BEGINNING TO PULL IT
FURTHER NORTH. HAVE INCLUDED SLIGHT CHANCE FOR PRECIPITATION
ACROSS SOUTHERN IOWA FOR TUESDAY INTO WEDNESDAY. WILL LIKELY SEE
RAIN CHANGING OVER TO SNOW. CURRENTLY...LIFT IS A BIT
LACKING...AND PRECIPITATION WILL LIKELY BE LIGHT.
BEHIND LOW...ANOTHER FRONTAL BOUNDARY WILL PUSH DOWN FROM CANADA.
ATTM APPEARS FROPA WILL BE DRY. MUCH COLDER AIR WILL WORK IN
BEHIND FRONT AND TEMPERATURES WILL GRADUALLY COOL TOWARDS END OF
PERIOD.
&&
.AVIATION...05/06Z
LARGE AREA OF STRATUS DROPPING SOUTH FROM MN NOW AND SOLID OVC003
WALL OF CLOUDS HEADING INTO THE AREA. ALREADY NEAR KMCW BY 06Z AND
EXPECTED TO HEAD TOWARD US 20 BY 08-09Z AT KALO AND KFOD. BY 12Z THE
AREA OF LOWER CLOUDS AND VSBY SHOULD BE NEARING KDSM AND THEN
BETWEEN 16-18Z FOR KOTM. WARM AIR ADVECTION ALOFT FROM THE NORTHERN
PLAINS AND SOUTHERN CANADA MAY ACT TO KEEP STRATUS GOING MOST OF THE
DAY ESPECIALLY GIVEN THE COLDER SFC TEMPS ACROSS MOST OF OUR AREA
NOW. WITH NEW SNOW PACK FROM I80 SOUTH TO BORDER...THIS AREA MIGHT
BE SUSCEPTIBLE TO THICK FOG DEVELOPMENT EITHER OVERNIGHT OR ON
SUNDAY AS WELL. NEXT FEW DAYS MAY THE REGION WILL HAVE ADDED
CHALLENGE OF BOUNDARY LAYER MOISTURE AND POSSIBLE ISSUES WITH FOG.
DIFFICULT TO TIME...BUT ONCE IT SETS UP...IT MAY STICK AROUND UNTIL
STRONGER SFC WINDS RETURN MONDAY NIGHT OR TUESDAY. HAVE PASSED
DETAILS ALONG TO NIGHT SHIFT FOR NEXT PACKAGE. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
SHORT TERM...SMALL/REV
LONG TERM...AWB
AVIATION...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1100 PM CST SAT FEB 4 2012
.UPDATE PUBLIC DISCUSSION...
.SHORT TERM /TONIGHT/...
...REMAINDER OF WARNINGS/ADVISORIES HAVE BEEN CANCELLED. STORM NOW
SOUTH OF AREA AND CONDITIONS CONTINUE TO IMPROVE.
...CONTINUE TO TRIM BACK ADVISORY. EASTERN AREAS OF LIGHT SNOW
NEARLY OVER AND SOUTHWEST CONTINUES LIGHT. WARNING AREA STILL
RECEIVING SOME ADDITIONAL LIGHT SNOW. ALL WILL EXPIRE AT 06Z.
NEXT ISSUE IS FOG AND LOW STRATUS. EXPECTING LOW STRATUS AND FOG TO
OVERTAKE NORTHERN BORDER COUNTIES NEAR MN BORDER BY 06Z AND
TRANSLATE SOUTH TO NEAR DES MOINES BY 12Z. HAVE ADDED AREAS FOG
NORTH AND MAINTAIN PATCHY FOG SOUTH. IF SKIES CLEAR AND FOG GETS A
FOOTHOLD...MAY BE SOME DENSE FOG. DIFFICULT TO DECIDE WHAT AREAS
MIGHT BE AT RISK FOR THAT...GIVEN APPROACHING CLOUDS. UPSTREAM
VSBYS LAST NIGHT WERE AT OR ABOVE 1/2SM SO...MIGHT NOT BE A MAJOR
ISSUE WITH THE EXCEPTION OF FROSTY ROAD SURFACES. WILL NEED TO
MONITOR THROUGH THE NIGHT.
HAVE TRIMMED BACK WINTER STORM WARNING WITH THE EXCEPTION OF WHERE
SNOW STILL FALLING IN SW IA. LEAVING ADVISORY AS IS...DUE TO BAND OF
SNOW STILL OCCURRING IN DEF ZONE OVER THE SOUTHEAST. MONITORING AREA
FOR FOG DEVELOPMENT LATE TONIGHT. ADVECTION FOG OVER MN AND
POTENTIAL FOR RADIATION FOG OVER IOWA MAY COMPLICATE TRAVEL
OVERNIGHT AND EARLY SUNDAY MORNING.
.PREVIOUS SHORT TERM /TONIGHT/...
PRIMARY CONCERNS REMAIN SNOW TRENDS. RADAR AND SATELLITE
OBSERVATIONS INDICATE THAT PRECIP INTENSITY IS BEGINNING TO WANE
WITH TOPS WARMING AND ECHOES DIMINISHING. MODELS CONFIRM THIS AS
WELL WITH 18Z RUC UVM AND MOISTURE BOTH DECREASING IN DENDRITIC
GROWTH ZONE AROUND H6/H5 OR 300K ISENT SURFACE. THIS THINKING HAS
LEAD TO CATEGORICAL POPS WITH LITTLE ADDITIONAL ACCUMULATION THROUGH
00Z...FOLLOWED BY FURTHER DECREASE IN POPS AND NORTH TO SOUTH
COVERAGE LATER THIS EVENING. MOST LOCAL VISIBILITIES ARE NOW 1SM OR
GREATER. HEADLINES WERE TRIMMED TO 06Z THIS AFTERNOON AND COULD
VERY WELL NEED TO BE CANCELLED EVEN EARLIER THIS EVENING IF TRENDS
CONTINUE.
NEXT CONCERN TURNS TO CONDITIONS OVERNIGHT. VERY SHALLOW STRATUS
AND FOG WAS MAKING HEADWAY SOUTH EARLIER THIS AFTERNOON BUT THAT HAS
NOW ERODED. LOW LEVEL WINDS WILL LIKELY BE JUST STRONG ENOUGH TO
PRECLUDE WIDESPREAD DENSE FOG. HOWEVER 21Z SURFACE ANALYSIS SHOWS
LACK OF MUCH DRYING UPSTREAM SO HAVE MENTIONED PATCHY FOG FOR A
START IN CASE THIS MOISTURE AREA DOES INDEED FILL BACK IN AGAIN.
.LONG TERM /SUNDAY THROUGH FRIDAY/...
LOW WILL HAVE PUSHED FURTHER EAST FOR BEGINNING OF PERIOD...WITH
HIGH PRESSURE PUSHING IN. HAVE INCLUDED MENTION FOR FOG ACROSS THE
NORTH EARLY SUNDAY MORNING...AND SHOULD LIFT BY LATE MORNING.
COULD AGAIN SEE FOG EARLY MONDAY...BUT NOT ENOUGH CONFIDENCE TO
INCLUDE MENTION ATTM. LOW OVER ROCKIES WILL DEEPEN...AND REMAIN
OVER ROCKIES THROUGH TUESDAY WITH SPLIT FLOW OVER REGION.
TEMPERATURES WILL WARM INTO MONDAY WITH WAA AND WEAK RIDGING OVER
IOWA.
STRONG WAVE WILL PUSH LOW OUT OF ROCKIES TUESDAY. THIS WILL BRING
A CHANCE FOR PRECIPITATION ACROSS IOWA. MODELS DO NOT HAVE GOOD RUN-
TO-RUN CONSISTENCY WITH TRACK OF LOW...BUT ARE BEGINNING TO PULL IT
FURTHER NORTH. HAVE INCLUDED SLIGHT CHANCE FOR PRECIPITATION
ACROSS SOUTHERN IOWA FOR TUESDAY INTO WEDNESDAY. WILL LIKELY SEE
RAIN CHANGING OVER TO SNOW. CURRENTLY...LIFT IS A BIT
LACKING...AND PRECIPITATION WILL LIKELY BE LIGHT.
BEHIND LOW...ANOTHER FRONTAL BOUNDARY WILL PUSH DOWN FROM CANADA.
ATTM APPEARS FROPA WILL BE DRY. MUCH COLDER AIR WILL WORK IN
BEHIND FRONT AND TEMPERATURES WILL GRADUALLY COOL TOWARDS END OF
PERIOD.
&&
.AVIATION...05/00Z
SYSTEM BEGINNING TO WEAKEN AS DEF ZONE LOSING SUPPORT FROM MAIN
UPPER LEVEL LOW PULLING OFF THE THE SOUTHEAST OF IA THIS EVENING.
CONSEQUENTLY...CIGS AND VSBYS WILL CONTINUE TO IMPROVE FOR THE SHORT
TERM WITH GENERALLY VFR FOR A SHORT PERIOD OF TIME. HOWEVER...BY MID
TO LATE EVENING AFT 05Z FOG POTENTIAL WILL INCREASE. FRESH SNOW
COVER AND CLEARING SKIES ALONG WITH AMPLE MOISTURE IN THE BOUNDARY
LAYER MAY LEAD TO FOG. QUESTION ABOUT MOISTURE DEPOSITION OR IF IT
REMAINS SUSPENDED. WINDS WILL REMAIN IN THE 7 TO 8KT RANGE...SO THIS
MAY HELP THE AIRMASS REMAIN MIXED AS THE ENTIRE COLUMN COOLS TO
SATURATION. THOUGH CONFIDENCE LOW...MAY NEED TO UPDATE FOR LIFR FOG
AND OR CIGS LATER THIS EVENING IF TRENDS FOR THICK FOG ARE
CONFIRMED. THEN...PERIOD OF MOST CONCERN WOULD SHIFT TO 10-15Z
SUNDAY MORNING. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE
&&
$$
SHORT TERM...SMALL/REV
LONG TERM...AWB
AVIATION...REV
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1122 PM CST SAT FEB 4 2012
...UPDATE TO AVIATION...
&&
.AVIATION...
LIGHT SNOW AND IFR CONDITIONS TO CONTINUE AT TOP AND MHK FOR THE
NIGHT...WITH LIFR CIGS AT FOE. SKIES CLEAR QUICKLY AFTER SUNRISE
AND LIGHT NORTHWEST WINDS CONTINUE THROUGH SUNDAY. 67
&&
.PREV DISCUSSION...
/ISSUED 308 PM CST SAT FEB 4 2012/
SHORT RANGE FORECAST (TONIGHT THROUGH SUNDAY)...
UPPER LEVEL LOW PRESSURE SYSTEM IS CURRENTLY CENTERED ROUGHLY OVER
KFNB AS OF 20Z PER WATER VAPOR IMAGERY AND RUC UPPER LEVEL ANALYSIS.
THE TROUGH HAS BEEN STEADY STATE REGARDING INTENSITY THROUGHOUT THE
DAY...MEANING IT HAS NOT UNDERGONE SIGNIFICANT STRENGTHENING OR
WEAKENING. WATER VAPOR IMAGERY ALSO INDICATING A SLOT OF DRY AIR
STRETCHING FROM SOUTH CENTRAL IOWA SOUTHWESTWARD TO THE
OKLAHOMA/TEXAS PANHANDLES. THIS DRY SLOT HAS CAUSED THE MID LEVELS
TO BECOME RATHER DRY...WHICH HAS CREATED A DRIZZLY AFTERNOON ACROSS
MUCH OF NORTHEAST KANSAS..ESPECIALLY EAST OF A MARYSVILLE TO TO
ABILENE LINE. WEST AND NORTH OF THAT LINE VERY LIGHT SNOW SHOWERS
ARE PERSISTING AS THE UPPER LOW RESIDES OVER THE AREA. WITH THE LACK
OF ANY APPRECIABLE MID LEVEL FRONTOGENESIS AND MEAGER OVERALL LIFT
INDICATED BY OMEGA VALUES PROGGED TO BE IN THE -2 TO -4 MICROBAR/SEC
RANGE...DO NOT EXPECT MUCH MORE SNOW TO FALL ACROSS ANY OF THE
FORECAST AREA DURING THE REMAINDER OF THE AFTERNOON AND EVENING.
ACROSS FAR EASTERN KANSAS...EXPECT CLOUDY CONDITIONS TO REMAIN WITH
PERIODS OF LIGHT RAIN AND PATCHY DRIZZLE. LATER THIS AFTERNOON
FORECAST MODELS HINT AT SOME DEEPER MOISTENING OF THE ATMOSPHERIC
COLUMN WHICH COULD ALLOW FOR SOME LIGHT SNOW SHOWERS ALONG THE
INTERSTATE 70 CORRIDOR LATER TONIGHT. SNOW AMOUNTS WILL BE PRETTY
MEAGER WITH ONLY A TENTH OR TWO OF AN INCH OF SNOW. EXPECT PRECIP TO
COME TO A GRADUAL END BY LATE SATURDAY NIGHT INTO EARLY SUNDAY
MORNING AS THE UPPER SYSTEM COMPLETELY MOVES OUT OF THE AREA. EXPECT
SKIES TO ALSO GRADUALLY CLEAR OVERNIGHT AND THROUGHOUT THE DAY ON
SUNDAY. MADE VERY FEW CHANGES TO TEMPERATURES FOR THE OVERNIGHT
HOURS SATURDAY AND DAYTIME PERIOD ON SUNDAY...BUT DID LOWER TEMPS ON
THE ORDER OF 3 TO 5 DEGREES WHERE THE MOST SNOW FELL...NAMELY ACROSS
CLOUD...REPUBLIC...WASHINGTON...AND MARSHALL COUNTIES.
JL
MONDAY AND MONDAY NIGHT...SURFACE HIGH PRESSURE AND AMPLIFYING
SOUTHERN RIDGE WILL KEEP CONDITIONS TRANQUIL ACROSS THE PLAINS
MONDAY AND MONDAY EVENING. SOUTHWESTERLY FLOW WILL RETURN TO THE
REGION ON MONDAY ON THE WEST SIDE OF THE SURFACE RIDGE ALONG WITH
WEAK WAA. MODELS PROG CANADIAN TROF TO SWEEP CUTOFF LOW OVER THE
WASATCH RANGE MONDAY AFTERNOON...AND OUT ONTO THE PLAINS BY MONDAY
NIGHT. AFTERNOON HIGHS ON MONDAY WILL BE SLIGHTLY ABOVE NORMAL IN
THE MID TO UPPER 40`S DUE TO THE WEAK WAA. THE NORTHWESTERN
COUNTIES WILL LIKELY REMAIN IN THE 30`S WITH THE SNOW COVER.
TUESDAY AND TUESDAY NIGHT...COLD FRONT EXPECTED TO SWEEP THROUGH THE
CWA TUESDAY MORNING. MID LEVEL MOISTURE ADVECTS INTO THE AREA FROM
THE WEST...WHERE LOW LEVEL MOISTURE ADVECTS IN WITH THE COLD AIR
BEHIND THE 850MB FRONT MID DAY TUESDAY. BUMPED UP POPS A BIT
TUESDAY MORNING AND AFTERNOON WITH SLOWLY GROWING CONFIDENCE THAT
PRECIP WILL OCCUR ON TUESDAY. ECMWF AND GFS HAD DIVERGED WITH THE
AREAS OF GREATEST QPF. GFS WAS MUCH FURTHER NORTH AND AWAY FROM BEST QG
FORCING SUPPORT OVER SOUTHERN KANSAS AND OKLAHOMA. ECMWF HAD BEEN
IN BETTER ALIGNMENT WITH THE QG FORCING. HOWEVER...LATEST ECMWF
ALIGNS IN BETTER AGREEMENT TO THE GFS THAN PREVIOUS RUNS...AND GIVEN
THE SIGNIFICANT PV ANOMALY PROGGED TO TRAVERSE EASTERN KANSAS
TUESDAY AFTERNOON AND EVENING...THINKING IS THAT ECMWF MAY BE ON
TRACK WITH HIGHER QPF AMOUNTS OVER EASTERN KANSAS THAN PREVIOUSLY
THOUGHT. FOR NOW...GIVEN INCONSISTENCY IN THE MODELS...BUMPED POPS
UP ONLY SLIGHTLY. NEXT QUESTION WILL BE PRECIP TYPE. FORECAST
SOUNDINGS INDICATE SFC TEMPS WILL BE CLOSE TO THE FREEZING MARK AT
THE SURFACE WITH DEPTHS OF ABOUT 400 FEET BEFORE SUB-ZERO
TEMPERATURES ARE REACHED ALOFT. HOWEVER...GFS DEPICTS 500MB DRY
SLOT NEAR THE ICE CRYSTAL GROWTH ZONE. IF ENOUGH DRY AIR WORKS INTO
THE GROWTH ZONE TO INHIBIT ICE CRYSTAL GROWTH...MAY ONLY SEE RAIN
INSTEAD OF ANY SNOW. LIFT IS NOT ABUNDANT WITH THIS SYSTEM...AND
MOST OF THE QG FORCING IS STILL PROGGED TO REMAIN SOUTH OF THE
CWA...BUT IF THE PV ANOMALY IS AS STRONG AS DEPICTED COUPLED WITH
MODERATE MOISTURE ADVECTION...COULD POSSIBLY SEE A FEW HUNDREDTHS OF
AN INCH OF PRECIPITATION.
EXTENDED...SYSTEM EXITS TUESDAY NIGHT INTO WEDNESDAY WITH THE NEXT
WAVE EXPECTED WEDNESDAY EVENING. THIS SYSTEM ALSO PROGGED TO HAVE A
STRONG PV ANOMALY...AND ECMWF IS PICKING UP ON SOME PRECIPITATION
OVER NORTHEAST KANSAS. ATTM...LEFT THE EXTENDED DRY GIVEN THE
VARIABILITY IN THE MODEL RUNS AND THE FAIRLY DRY ATMOSPHERE IN PLACE
THURSDAY AFTERNOON. NEXT SYSTEM AND COLD FRONT EXPECTED THURSDAY EVENING AND
HIGH PRESSURE RETURNING ON FRIDAY AND SATURDAY. TEMPERATURES
WISE...SHOULD SEE HIGHS NEAR NORMAL WITH LOWS IN THE 20`S AND HIGHS
IN THE UPPER 30`S AND LOW 40`S. EXCEPTION WILL BE WITH THE SNOW
PACKED AREAS WITH HIGHS IN THE 30`S AND LOWS IN THE TEENS.
BYRNE
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
837 PM EST MON FEB 06 2012
...Forecast Update...
Forecast is in good shape -- just a couple of tweaks. Have been
watching run-to-run consistency in the RR/HRRR models, and as a
result have decided to go ahead and add patchy fog to southern
Indiana and northern Kentucky for the early morning hours Tuesday.
Also, given this morning`s lows and current dew points, dropped MinT
tonight in the north and central sections of the CWA a couple of
degrees. If fog does develop, we could see a few slick spots on
overpasses for the morning commute. Dropped sky cover to 0% for the
next several hours since we`re clear. Some scattered low clouds may
accompany any early morning fog, so brought a few clouds back in by
morning.
&&
.Short Term (Tonight - Wednesday Night)...
The main forecast challenge over the next few days will be precip
type and amount with a weak system pushing through the area late
Tuesday night through Wednesday night.
Water vapor imagery shows a weak trough overhead moving east across
Kentucky. Subsidence behind this and low-level moisture allowed for
fog to form under clearing skies this morning across portions of
south-central IN and north-central KY. Clouds persisted over the
southern half of the CWA and are finally scattering out across the
Lake Cumberland region. High pressure will settle into the region
tonight with ridging aloft. This will allow for mostly clear skies
and light and variable winds. Once again, fog may form tonight, but
think the best chance will be over south-central KY where clouds
lingered the longest this morning. Lows may dip down into the upper
20s over the north to freezing or just below over the south, so it
is possible that freezing fog may occur across south-central KY
towards dawn.
Expect mostly sunny skies to start the first half of the day
tomorrow, but with ridging pushing across the area quickly, it will
be replaced with a weakening upper low pushing towards the area from
Colorado, also currently seen in WV imagery. Clouds will increase
from the west during the day, but it shouldn`t impact our highs too
much. We`ll still reach the low to mid 50s tomorrow.
A larger trough will be diving south across the Midwest behind the
approaching weak low, it may be enhanced a bit as it traverses the
region, more so than what the NAM is showing. The GFS and Euro are
both hinting at even more QPF than before, however still light in
nature. Looks like any precip with the upper low will reach our
western CWA after midnight Tuesday night, spreading across the
region into Wednesday. Temperature profiles show that we`ll saturate
from top down, so any precip would likely be light snow over the
north half, or a light rain/snow mix over the south half through
Wednesday morning. As temps warm up a bit on Wednesday, any light
snow could changeover to a light mix, but overall impact would be
minimal with warm grounds and temps climbing to near/around 40.
Looking at QPF amounts around a tenth or less most spots, so
expecting no snow accumulation at this point. We end POPs over most
areas except the far east Wednesday afternoon, and actually linger
flurries into the night ending by midnight over the far eastern
Bluegrass given the main upper trough lagging a bit.
Behind the system, temps will drop overnight as larger upper trough
swings through, but not too much given some residual cloud cover and
winds possibly staying up a bit. Look for lows in the mid to upper
20s Wednesday night.
.Long Term (Thursday - Monday)...
We`ll begin the period with a weak upper level trough pushing
through the region Thurs. Although no precip is expected to
accompany this feature, it does look like the trough will hold temps
at bay in the lower 40s for highs. Raw model temps actually keep us
in the upper 30s for highs but with full sunshine will anticipate
lower 40s max.
Friday we`ll see a brief warm up ahead of an approaching cold front
and broad upper trough. The front should come through sometime Fri
evening/night along with some sprinkles or flurries especially east
of I-65. Although models vary on the degree of cold air behind the
front, the more consistent models indicate a colder soln which jives
with a slight upward trend in the forecast AO and downward trend in
the forecast NAO/PNA. Therefore did nudge forecast numbers down to
CONSRaw for Sat/Sun. Forecast highs for Sat are very uncertain.
Went with low to mid 30s for now, but they could definitely be
colder if raw model numbers in the ECMWF play out. Sunday will also
be chilly in the mid 30s for highs as the broad upper trough stays
over the region.
Sunday night/Monday we`ll enter a more zonal flow allowing temps to
moderate into the low 40s for highs. Another weather system may
bring precip to the area in the Mon/Tues time frame, however, models
are flip-flopping quite a bit for early next week. Stay tuned for
further updates!
&&
.Aviation (00Z TAF Issuance)...
Fog will again be the main concern for this TAF package. RR and
HRRR models did an excellent job yesterday in pinpointing where this
morning`s fog would develop. Tonight these models suggest that the
best morning fog will lay across southern Indiana and northern
Kentucky. The GFS paints its lowest dew point depressions at 12Z in
that same area, and atmospheric cross-sections on the GFS suggest
the best surface RH in the north as well. The NAM, on the other
hand, prefers to develop fog southeast of all the terminals towards
Lake Cumberland, which makes some sense since that region had the
most cloud cover during the day to limit heating and drying, and dew
points are slightly higher there.
Have decided that we just can`t ignore what the well-performing
RR/HRRR are showing, especially with the GFS lending them some
support. However will not go crazy with the fog. Will introduce
some MVFR BR at SDF and LEX for the morning hours under otherwise
clear skies. Though none of the models favor much fog at BWG, with
clear skies and light winds and dew point depressions progged at 12Z
to be less than two degrees, plus BWG`s tendency to fog in easily,
will continue mention of MVFR BR there as well.
Otherwise this TAF period will be characterized by mostly clear
skies and winds below 7 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........13
Short Term.......AL
Long Term........AMS
Aviation.........13
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
612 PM EST MON FEB 06 2012
...Updated Aviation Discussion...
.Short Term (Tonight - Wednesday Night)...
The main forecast challenge over the next few days will be precip
type and amount with a weak system pushing through the area late
Tuesday night through Wednesday night.
Water vapor imagery shows a weak trough overhead moving east across
Kentucky. Subsidence behind this and low-level moisture allowed for
fog to form under clearing skies this morning across portions of
south-central IN and north-central KY. Clouds persisted over the
southern half of the CWA and are finally scattering out across the
Lake Cumberland region. High pressure will settle into the region
tonight with ridging aloft. This will allow for mostly clear skies
and light and variable winds. Once again, fog may form tonight, but
think the best chance will be over south-central KY where clouds
lingered the longest this morning. Lows may dip down into the upper
20s over the north to freezing or just below over the south, so it
is possible that freezing fog may occur across south-central KY
towards dawn.
Expect mostly sunny skies to start the first half of the day
tomorrow, but with ridging pushing across the area quickly, it will
be replaced with a weakening upper low pushing towards the area from
Colorado, also currently seen in WV imagery. Clouds will increase
from the west during the day, but it shouldn`t impact our highs too
much. We`ll still reach the low to mid 50s tomorrow.
A larger trough will be diving south across the Midwest behind the
approaching weak low, it may be enhanced a bit as it traverses the
region, more so than what the NAM is showing. The GFS and Euro are
both hinting at even more QPF than before, however still light in
nature. Looks like any precip with the upper low will reach our
western CWA after midnight Tuesday night, spreading across the
region into Wednesday. Temperature profiles show that we`ll saturate
from top down, so any precip would likely be light snow over the
north half, or a light rain/snow mix over the south half through
Wednesday morning. As temps warm up a bit on Wednesday, any light
snow could changeover to a light mix, but overall impact would be
minimal with warm grounds and temps climbing to near/around 40.
Looking at QPF amounts around a tenth or less most spots, so
expecting no snow accumulation at this point. We end POPs over most
areas except the far east Wednesday afternoon, and actually linger
flurries into the night ending by midnight over the far eastern
Bluegrass given the main upper trough lagging a bit.
Behind the system, temps will drop overnight as larger upper trough
swings through, but not too much given some residual cloud cover and
winds possibly staying up a bit. Look for lows in the mid to upper
20s Wednesday night.
.Long Term (Thursday - Monday)...
We`ll begin the period with a weak upper level trough pushing
through the region Thurs. Although no precip is expected to
accompany this feature, it does look like the trough will hold temps
at bay in the lower 40s for highs. Raw model temps actually keep us
in the upper 30s for highs but with full sunshine will anticipate
lower 40s max.
Friday we`ll see a brief warm up ahead of an approaching cold front
and broad upper trough. The front should come through sometime Fri
evening/night along with some sprinkles or flurries especially east
of I-65. Although models vary on the degree of cold air behind the
front, the more consistent models indicate a colder soln which jives
with a slight upward trend in the forecast AO and downward trend in
the forecast NAO/PNA. Therefore did nudge forecast numbers down to
CONSRaw for Sat/Sun. Forecast highs for Sat are very uncertain.
Went with low to mid 30s for now, but they could definitely be
colder if raw model numbers in the ECMWF play out. Sunday will also
be chilly in the mid 30s for highs as the broad upper trough stays
over the region.
Sunday night/Monday we`ll enter a more zonal flow allowing temps to
moderate into the low 40s for highs. Another weather system may
bring precip to the area in the Mon/Tues time frame, however, models
are flip-flopping quite a bit for early next week. Stay tuned for
further updates!
&&
.Aviation (00Z TAF Issuance)...
Fog will again be the main concern for this TAF package. RR and
HRRR models did an excellent job yesterday in pinpointing where this
morning`s fog would develop. Tonight these models suggest that the
best morning fog will lay across southern Indiana and northern
Kentucky. The GFS paints its lowest dew point depressions at 12Z in
that same area, and atmospheric cross-sections on the GFS suggest
the best surface RH in the north as well. The NAM, on the other
hand, prefers to develop fog southeast of all the terminals towards
Lake Cumberland, which makes some sense since that region had the
most cloud cover during the day to limit heating and drying, and dew
points are slightly higher there.
Have decided that we just can`t ignore what the well-performing
RR/HRRR are showing, especially with the GFS lending them some
support. However will not go crazy with the fog. Will introduce
some MVFR BR at SDF and LEX for the morning hours under otherwise
clear skies. Though none of the models favor much fog at BWG, with
clear skies and light winds and dew point depressions progged at 12Z
to be less than two degrees, plus BWG`s tendency to fog in easily,
will continue mention of MVFR BR there as well.
Otherwise this TAF period will be characterized by mostly clear
skies and winds below 7 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......AL
Long Term........AMS
Aviation.........13
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1254 PM EST SUN FEB 05 2012
...Updated Aviation Discussion...
...1 PM Forecast Update...
Updated the forecast to extend light rain showers/drizzle over south
central KY into the tonight period through 3Z. Short range models
and upstream obs indicate this light precip on the eastern side of
the upper low. It is progged to pass through south central KY
between 21Z-3Z.
10 AM Forecast Update...
Updated the forecast this morning to remove fog wording from the
zones. Also, according to 12Z NAM and 12Z HRRR moisture/CIG
fields...it looks like low clouds may stick around a bit longer than
previously anticipated. The adjustment of clearing to the forecast
was only by an 1 or 2. Satellite trends this morning justify this
thinking. NE sections of our forecast area including Lexington will
be one of the first to see low clouds scatter out. No major temp
adjustments this morning. Highs still look to be limited to the mid
40s to around 50.
7 AM Forecast Update...
Drier air continues to slowly work southward as surface low over the
Carolinas departs to the east and surface trough swings through the
area. Some patches of dense fog and areas of low stratus have
developed this morning, although conditions should gradually improve
through the morning hours as the sun comes up and drier air
continues to work in. Issued a Special Weather Statement across
central Kentucky for the patches of dense fog through 9 AM EST. A
few patches of drizzle will also exist through midday, along with
the small chance that a light rain shower could measure. Otherwise,
temperatures will struggle today under northeasterly flow and slow
to clear clouds. Look for highs in the mid and upper 40s, but would
not be surprised to only see the mercury make it to the mid 40s.
&&
.Short Term (Today and Tonight)...
Surface low has moved east of the Appalachian spine to the North
Carolina/Virginia border. Meanwhile, upper low continues to spin
over the Kansas City region. Low clouds and patches of drizzle
remain over the area, along with patches of fog. Have left mention
of a slight chance of a measurable rain shower in the grids early
this morning, however think most locations will only see drizzle.
Temperatures will continue to drop into the upper 30s and low 40s
north of the parkways. Mid and upper 40s are expected across south
central Kentucky as winds have not shifted to northeasterly on the
warm side of a surface trough.
As we move through the daylight hours, surface low will move off the
Carolina Coast with upper low transitioning to an open wave. Expect
low clouds and slight chances of a measurable rain shower or drizzle
ahead of the nearly East/West oriented upper trough axis that
develops along the Ohio River to the eastern Plains. This axis will
gradually sink south along with deepest low level moisture, ending
chances of precipitation from north to south through the day. Skies
will also begin to clear out in the afternoon along and north of the
I 64 corridor. High temperatures are expected to struggle with cloud
cover for a good portion of the day along with northeasterly surface
flow. Look for highs mainly in the middle to upper 40s.
As we move into tonight, skies should be mostly clear as drier air
works into the region on continued northerly flow. Surface high will
be in control along with upper level ridging over the northern CWA.
Have patchy fog developing mostly in the sheltered valleys and in
southwestern Indiana under the upper level ridge. Think drier
airmass will keep fog from becoming more widespread, however will
have to monitor. Lows should dip into the lower 30s in most spots
with a few of the cool spots into the upper 20s.
.Long Term (Monday - Saturday)...
Slow-moving upper low in the short term will pick up steam toward
the east and clear the region during the day Monday. High pressure
building into the area will mean dry conditions at least through
Tuesday. Then from midweek on a series of upper level disturbances
will set up a large-scale trough over the Eastern U.S., bringing in
a more winter like cool down. None of the systems look overly wet
among the various long-term models. As the large-scale trough
becomes better established later in the day Friday, we may see a
band of precip come across, as per the latest GEM and GFS solutions.
GFS sounding indicates most of the layer will be below freezing,
except for a warmer surface. Previous forecast kept best chance,
only slight, in for Wednesday, then dry through the end of the
period. Will trim pops a little Wednesday and bump them up a little
Friday and Friday night, to slight chance over the east and
southeast, in line with the AllBlend. Both sets of periods will keep
as a rain/snow mix given forecast soundings and surface temperature
forecasts.
Speaking of temperatures, have readings starting off around 50 for
highs Monday, going up a few degrees over the south Tuesday, then
should be in the 40s all locations Wednesday and Thursday. The
cooler air will filter in Friday, with highs in the 30s over the
north. Then Saturday, all but south central Kentucky should remain
in the 30s for highs. Saturday morning should be the coolest of all
locations, with lows in the 20s.
&&
.Aviation (18Z TAF Issuance)...
An upper low over eastern MO this afternoon will move east to
eastern KY by tomorrow afternoon. This will allow a prolonged
period of low clouds this afternoon/evening for all TAF sites.
Although CIGS have slowly begun to lift, MVFR/IFR CIGs will continue
through at least 20Z. LEX will be the first to improve to VFR this
afternoon followed shortly by SDF and then BWG this evening. There
is a small chance that BWG may see another patch of drizzle this
evening, but radar imagery upstream indicates that drizzle is waning
and so will leave out of BWG TAF for now. Tonight, expect CIGS to
hang around at BWG through the early morning hours before
scattering. After CIGs scatter, some BR will be possible. The fog
forecast for BWG tonight has a moderate level of uncertainty due to
the timing on CIGS scattering and the passage of the upper low. For
SDF/LEX indicators are fairly clear that skies will clear this
evening and allow a long period of rad cooling overnight. This
should lead to at least IFR fog by morning...possibly lower. VSBYs
will improve starting around 14Z-15Z tomorrow.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS/BJS
Short Term.......BJS
Long Term........RJS
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1229 PM EST SUN FEB 05 2012
...Updated Aviation Discussion...
...10 AM Forecast Update...
Updated the forecast this morning to remove fog wording from the
zones. Also, according to 12Z NAM and 12Z HRRR moisture/CIG
fields...it looks like low clouds may stick around a bit longer than
previously anticipated. The adjustment of clearing to the forecast
was only by an 1 or 2. Satellite trends this morning justify this
thinking. NE sections of our forecast area including Lexington will
be one of the first to see low clouds scatter out. No major temp
adjustments this morning. Highs still look to be limited to the mid
40s to around 50.
7 AM Forecast Update...
Drier air continues to slowly work southward as surface low over the
Carolinas departs to the east and surface trough swings through the
area. Some patches of dense fog and areas of low stratus have
developed this morning, although conditions should gradually improve
through the morning hours as the sun comes up and drier air
continues to work in. Issued a Special Weather Statement across
central Kentucky for the patches of dense fog through 9 AM EST. A
few patches of drizzle will also exist through midday, along with
the small chance that a light rain shower could measure. Otherwise,
temperatures will struggle today under northeasterly flow and slow
to clear clouds. Look for highs in the mid and upper 40s, but would
not be surprised to only see the mercury make it to the mid 40s.
&&
.Short Term (Today and Tonight)...
Surface low has moved east of the Appalachian spine to the North
Carolina/Virginia border. Meanwhile, upper low continues to spin
over the Kansas City region. Low clouds and patches of drizzle
remain over the area, along with patches of fog. Have left mention
of a slight chance of a measurable rain shower in the grids early
this morning, however think most locations will only see drizzle.
Temperatures will continue to drop into the upper 30s and low 40s
north of the parkways. Mid and upper 40s are expected across south
central Kentucky as winds have not shifted to northeasterly on the
warm side of a surface trough.
As we move through the daylight hours, surface low will move off the
Carolina Coast with upper low transitioning to an open wave. Expect
low clouds and slight chances of a measurable rain shower or drizzle
ahead of the nearly East/West oriented upper trough axis that
develops along the Ohio River to the eastern Plains. This axis will
gradually sink south along with deepest low level moisture, ending
chances of precipitation from north to south through the day. Skies
will also begin to clear out in the afternoon along and north of the
I 64 corridor. High temperatures are expected to struggle with cloud
cover for a good portion of the day along with northeasterly surface
flow. Look for highs mainly in the middle to upper 40s.
As we move into tonight, skies should be mostly clear as drier air
works into the region on continued northerly flow. Surface high will
be in control along with upper level ridging over the northern CWA.
Have patchy fog developing mostly in the sheltered valleys and in
southwestern Indiana under the upper level ridge. Think drier
airmass will keep fog from becoming more widespread, however will
have to monitor. Lows should dip into the lower 30s in most spots
with a few of the cool spots into the upper 20s.
.Long Term (Monday - Saturday)...
Slow-moving upper low in the short term will pick up steam toward
the east and clear the region during the day Monday. High pressure
building into the area will mean dry conditions at least through
Tuesday. Then from midweek on a series of upper level disturbances
will set up a large-scale trough over the Eastern U.S., bringing in
a more winter like cool down. None of the systems look overly wet
among the various long-term models. As the large-scale trough
becomes better established later in the day Friday, we may see a
band of precip come across, as per the latest GEM and GFS solutions.
GFS sounding indicates most of the layer will be below freezing,
except for a warmer surface. Previous forecast kept best chance,
only slight, in for Wednesday, then dry through the end of the
period. Will trim pops a little Wednesday and bump them up a little
Friday and Friday night, to slight chance over the east and
southeast, in line with the AllBlend. Both sets of periods will keep
as a rain/snow mix given forecast soundings and surface temperature
forecasts.
Speaking of temperatures, have readings starting off around 50 for
highs Monday, going up a few degrees over the south Tuesday, then
should be in the 40s all locations Wednesday and Thursday. The
cooler air will filter in Friday, with highs in the 30s over the
north. Then Saturday, all but south central Kentucky should remain
in the 30s for highs. Saturday morning should be the coolest of all
locations, with lows in the 20s.
&&
.Aviation (18Z TAF Issuance)...
An upper low over eastern MO this afternoon will move east to
eastern KY by tomorrow afternoon. This will allow a prolonged
period of low clouds this afternoon/evening for all TAF sites.
Although CIGS have slowly begun to lift, MVFR/IFR CIGs will continue
through at least 20Z. LEX will be the first to improve to VFR this
afternoon followed shortly by SDF and then BWG this evening. There
is a small chance that BWG may see another patch of drizzle this
evening, but radar imagery upstream indicates that drizzle is waning
and so will leave out of BWG TAF for now. Tonight, expect CIGS to
hang around at BWG through the early morning hours before
scattering. After CIGs scatter, some BR will be possible. The fog
forecast for BWG tonight has a moderate level of uncertainty due to
the timing on CIGS scattering and the passage of the upper low. For
SDF/LEX indicators are fairly clear that skies will clear this
evening and allow a long period of rad cooling overnight. This
should lead to at least IFR fog by morning...possibly lower. VSBYs
will improve starting around 14Z-15Z tomorrow.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS/BJS
Short Term.......BJS
Long Term........RJS
Aviation.........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
958 AM EST SUN FEB 05 2012
...10 AM Forecast Update...
Updated the forecast this morning to remove fog wording from the
zones. Also, according to 12Z NAM and 12Z HRRR moisture/CIG
fields...it looks like low clouds may stick around a bit longer than
previously anticipated. The adjustment of clearing to the forecast
was only by an 1 or 2. Satellite trends this morning justify this
thinking. NE sections of our forecast area including Lexington will
be one of the first to see low clouds scatter out. No major temp
adjustments this morning. Highs still look to be limited to the mid
40s to around 50.
7 AM Forecast Update...
Drier air continues to slowly work southward as surface low over the
Carolinas departs to the east and surface trough swings through the
area. Some patches of dense fog and areas of low stratus have
developed this morning, although conditions should gradually improve
through the morning hours as the sun comes up and drier air
continues to work in. Issued a Special Weather Statement across
central Kentucky for the patches of dense fog through 9 AM EST. A
few patches of drizzle will also exist through midday, along with
the small chance that a light rain shower could measure. Otherwise,
temperatures will struggle today under northeasterly flow and slow
to clear clouds. Look for highs in the mid and upper 40s, but would
not be surprised to only see the mercury make it to the mid 40s.
&&
.Short Term (Today and Tonight)...
Surface low has moved east of the Appalachian spine to the North
Carolina/Virginia border. Meanwhile, upper low continues to spin
over the Kansas City region. Low clouds and patches of drizzle
remain over the area, along with patches of fog. Have left mention
of a slight chance of a measurable rain shower in the grids early
this morning, however think most locations will only see drizzle.
Temperatures will continue to drop into the upper 30s and low 40s
north of the parkways. Mid and upper 40s are expected across south
central Kentucky as winds have not shifted to northeasterly on the
warm side of a surface trough.
As we move through the daylight hours, surface low will move off the
Carolina Coast with upper low transitioning to an open wave. Expect
low clouds and slight chances of a measurable rain shower or drizzle
ahead of the nearly East/West oriented upper trough axis that
develops along the Ohio River to the eastern Plains. This axis will
gradually sink south along with deepest low level moisture, ending
chances of precipitation from north to south through the day. Skies
will also begin to clear out in the afternoon along and north of the
I 64 corridor. High temperatures are expected to struggle with cloud
cover for a good portion of the day along with northeasterly surface
flow. Look for highs mainly in the middle to upper 40s.
As we move into tonight, skies should be mostly clear as drier air
works into the region on continued northerly flow. Surface high will
be in control along with upper level ridging over the northern CWA.
Have patchy fog developing mostly in the sheltered valleys and in
southwestern Indiana under the upper level ridge. Think drier
airmass will keep fog from becoming more widespread, however will
have to monitor. Lows should dip into the lower 30s in most spots
with a few of the cool spots into the upper 20s.
.Long Term (Monday - Saturday)...
Slow-moving upper low in the short term will pick up steam toward
the east and clear the region during the day Monday. High pressure
building into the area will mean dry conditions at least through
Tuesday. Then from midweek on a series of upper level disturbances
will set up a large-scale trough over the Eastern U.S., bringing in
a more winter like cool down. None of the systems look overly wet
among the various long-term models. As the large-scale trough
becomes better established later in the day Friday, we may see a
band of precip come across, as per the latest GEM and GFS solutions.
GFS sounding indicates most of the layer will be below freezing,
except for a warmer surface. Previous forecast kept best chance,
only slight, in for Wednesday, then dry through the end of the
period. Will trim pops a little Wednesday and bump them up a little
Friday and Friday night, to slight chance over the east and
southeast, in line with the AllBlend. Both sets of periods will keep
as a rain/snow mix given forecast soundings and surface temperature
forecasts.
Speaking of temperatures, have readings starting off around 50 for
highs Monday, going up a few degrees over the south Tuesday, then
should be in the 40s all locations Wednesday and Thursday. The
cooler air will filter in Friday, with highs in the 30s over the
north. Then Saturday, all but south central Kentucky should remain
in the 30s for highs. Saturday morning should be the coolest all
locations, with lows in the 20s.
&&
.Aviation (12Z TAF Issuance)...
Low pressure over the Carolinas will move off the coast today.
Meanwhile, an upper level disturbance will remain just to our north
and west. Low ceilings, drizzle, and an occasional light rain shower
will be possible through at least midday before conditions begin to
clear from north to south as drier air works in. Have IFR ceilings
persisting at SDF/LEX until around Noon EST before ceilings
gradually scatter out through the afternoon. Expect generally north
northeast winds between 5 and 10 mph through the day.
BWG is a lower confidence forecast. Expect ceiling in the IFR range
early this morning to give way to mostly low MVFR ceilings by mid
morning. Thereafter, expect mostly low MVFR through the remainder of
the day, although could see a few brief periods of IFR before low
level moisture exits to the south this evening.
With clear skies and calming winds expected later tonight, fog may
become a concern at the TAF sites toward dawn. Will nail this down
with later issuances.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AMS/BJS
Short Term.......BJS
Long Term........RJS
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
824 PM EST MON FEB 6 2012
.SYNOPSIS...
AN UPPER TROUGH WILL PASS THROUGH THE REGION WEDNESDAY. HIGH
PRESSURE RETURNS THURSDAY AND FRIDAY. A COLD FRONT MOVING INTO THE
REGION WILL BRING COLDER AIR TO THE MID ATLANTIC FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LTST SFC ANALY REVEALS A DIFFUSE AREA OF SFC HIPRES ACRS THE MID
ALTC...SERN CONUS...AND LWR-MID MS VLY. HWVR...WATER VAPOR AND
SATPIX REVEAL A S/WV EMBEDDED W/IN MEAN LYR FLOW...TREKKING ACRS
WVA ATTM. PRVS GDNC RUNS SUGGESTED THERE WUD BE SOME PCPN ASSOCD
W/ THIS SYSTM. TDA...ALMOST ALL GDNC DRY. THE HRRR IS THE SOLE MDL
SUGGESTING A LTL QPF PSBL...BUT EVEN THAT DRIES UP AS IT CROSSES
THE APPLCHNS TWD THE CENTRL SHEN VLY.
RNK 00Z RAOB SATD UP THRU H7...BUT ITS DRY ABV THAT LYR. PWAT
0.41 IN. LWX RAOB EVEN DRIER THAN THAT...PWAT A MERE 0.23 IN.
THINK WE/RE HARD PRESSED TO SEE MEASUREABLE PCPN TNGT. IF
ANYTHING FALLS /AND THATS QSTNBL ATTM/...IT WUD BE
SPRINKLES/FLURRIES. WL BACK OFF THE POPS...BUT ATTEMPT TO TRACK
CLDS ACRS CWFA IN ASSOC W/ THE VORT.
CURRENT TEMPS/FCST MIN-T SEEM TO BE IN LINE W/ LTST LAMP OFFERING.
WL MAKE NO TEMP ADJUSTMENTS ATTM.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
RIDGING ACROSS THE E-CNTRL CONUS BRINGS NWLY FLOW AND SUNNY SKIES
TO THE START OF TUESDAY...WITH HIGH CLOUDS ENTERING THE REGION
FROM THE WEST LATE IN THE DAY. MILD DAY WITH DOWNSLOPING
FLOW...MAX TEMPS LOW TO MID 50S NORTH...MID TO UPR 50S SOUTH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
IT LOOKS LK THERE`S GOING TO BE SOME CHG TO THE PATTERN IN THE WK
AHD...BUT LTL IN THE WAY OF SNOW IS FORESEEN. PRIOR TO GETTING TO
THE PATTERN CHG WE`LL HV A SHORT WV TO CONTEND W/ LATE TUE NGT AND
WED...W/ THE ACCENT ON WED. THIS LOOKS TO BE A FAST MOVER...AND
COLD AIR WL BE AT A MINIMUM. THERE`S EVEN A QUSTN AS TO HOW MUCH
MOISTURE WL BE AVBL E OF THE MTNS. WHATEVER SNOW OCCURS E OF THE
MTNS IT WOULD PSBLY BE 1) ARND SUNRISE...OR IF THE ECM IS CORRECT
LATER..AND 2) LGT. E OF THE MTNS WED TEMPS XPCTD TO CLIMB INTO THE
M40S...M30S IN THE HIGHLANDS. UPSLOPE COMPONENT PSBL ALONG THE WRN
RIDGES. HOWEVER MOISTURE LOOKS IN SHORT SUPPLY AND COME TO AN END
QUICKLY. FOR THE FAR W WL INCRS POPS TO "LKLY" AND FCST ARND 1".
MID CONTINENTAL HIGH PRES WL BUILD INTO THE MID ATLC FOR THU AND
FRI. TEMPS ARND AVG - HIGHS IN THE U40S/LOWS IN THE U20S/L30S.
UPR RDG BUILDS UP THE W CST INTO THE NWT DURG THIS WK. THIS IS
CAUSING SOME OF THE VERY COLD AIR WHICH HAS BEEN BLDG UP OVR AK
DURG THE PAST SVRL WKS TO DROP INTO QUEBEC FRI...AND IN A MUCH
MODERATED FORM THE MID ATLC THIS WKND. HIGHS SAT RANGING FM U30S
ALONG THE MASON-DIXON LN TO LM 40S IN THE CENTRAL SHN VLLY.
GFS DOES SHOW LOW PRES OVR FL ON SAT. AT THIS TIME THE LOW IS
PROGGED TO BE EITHER TOO FAR S OF E TO AFFECT MID ATLC. LOWS IN
THE LM20S SAT NGT (TEENS IN THE HIGHLANDS). HIGHS SUNDAY IN THE
U30/L40S.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF VALID PERIOD.
SIGNIFICANTLY DRIER AIR IS IN PLACE TONIGHT THEN THERE WAS LAST
NIGHT SO DO NOT EXPECT ANY FOG FORMATION NEAR AREA TERMINALS. WIND
WILL CONTINUE TO BACK BECOMING NW OVERNIGHT. MOSTLY CLEAR SKIES
TOMORROW WILL LEAD TO 10KT WINDS MIXING DOWN TO THE SURFACE BY NOON.
AN APPROACHING SHORTWAVE WILL GRADUALLY INCREASE CLOUD COVER WITH
SKIES BECOMING MOSTLY CLOUDY LATE TUESDAY EVENING.
A FAST MOVG SHORT WV WL CROSS THE MID ATLC RGN WED...PSBLY BRING
R/S E OF THE MTNS AND MVFR CIGS. HIGH PRES BUILDS BACK IN WED NGT
THRU FRI. COLDER AIR MOVES INTO THE RGN NEXT WKND.
&&
.MARINE...
SWLY FLOW CHANNELING 10 TO 15 KT...BEFORE BECOMING NWLY LATE
TONIGHT BEHIND A WEAK DISTURBANCE. WE/RE CLOSE TO SCA ATTM...BUT
DONT THINK WE/LL ACTUALLY GET THERE...AND THE WINDOW OF
OPPORTUNITY IS CLOSING SOON ANYWAY.
NLY FLOW TUESDAY 10 TO 15 KT AHD OF BLDG HIPRES.
A SHORT WV WL CROSS THE RGN ON WED. HIGH PRES BDLG INTO THE WATERS
WL PSBLY LEAD TO SHORT CRFT ADVSRY LATE WED NGT AND THU. COLD AIR
BLDG INTO THE WATERS COULD CREATE SCA CONDS SAT.
&&
.CLIMATE...
A CONTINUED LOOK AT THIS WINTER`S TEMPS (SO FAR 12/1-2/5)...
SITE AVG TEMP RANK
DCA 42.6 5TH WARMEST SINCE 1871
BWI 40.0 12TH WARMEST SINCE 1870
IAD39.33RD WARMEST SINCE 1971
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...HTS
SHORT TERM...JACKSON
LONG TERM...WOODY!
AVIATION...CJL/WOODY!
MARINE...HTS/WOODY!
CLIMATE...WOODY!
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
627 AM EST SUN FEB 5 2012
.SYNOPSIS...
ANY REMAINING MIX OF LIGHT RAIN AND SNOW ACROSS THE MOUNTAINS WILL
END THIS MORNING, AS UPPER LEVEL DISTURBANCE EXITS EAST. HIGH
PRESSURE, COMING EAST FROM THE PLAINS, WILL THEN FOLLOW TO BRING SUNSHINE
BY AFTERNOON, AND AGAIN ON MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RECENT RADAR DATA TRENDS AND HRRR AND WRF-NMM MODEL OUTPUT
CONTINUE TO SHOW ANY LIGHT MIX OF RAIN AND WET SNOW ACROSS THE
SOUTH EAST RIDGES WILL END BEFORE MID-MORNING, AS AN UPPER LEVEL
JETSTREAM MAX EXITS EAST. THERE MAY BE A SMALL ACCUMULATION OF WET
SNOW OVER THE HIGHER MOUNTAINS.
RECENT SURFACE DATA SHOWS SIGNS THAT THE LOW CLOUDS RESULTING IN
FOG PATCHES OVER THE HIGHER PA-WV-MD MOUNTAINS, HAS BEGUN TO LIFT. SO
EXPECT ANY REMAINING HIGHER ELEVATION FOG TO HAVE ENDED BY 9 AM.
PER TRENDS IN RECENT SATELLITE DATA AND SUPPORT FROM RECENT HRRR
AND NAM MODEL OUTPUT, EXPECT CLOUDS TO ALSO DECREASE, NORTH TO
SOUTH, THIS MORNING, YIELDING A DECENT AMOUNT OF SUNSHINE BY AFTERNOON.
HAVE CONTINUED TO FINE TUNE TEMPERATURE FORECAST PER RECENT HRRR
AND GFS LAMP MODEL OUTPUT. EXPECT AFTERNOON HIGHS TO BE 2 TO 5
DEGREES WARMER THAN NORMAL, WHICH IS ALSO SUPPORTED BY RECENT NAM
AND GFS MOS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
BLEND OF RECENT SREF AND ECMWF MODEL OUTPUT SHOWS SPRAWLING HIGH
PRESSURE, EXTENDING FROM THE PLAINS TO THE APPALACHIANS, WILL
PROVIDE NO MORE THAN SCATTERED CLOUDS ACROSS THE UPPER OHIO VALLEY
TONIGHT INTO TUESDAY. THIS WILL MAINTAIN MILD CONDITIONS, WITH
LOWS AND HIGHS GENERALLY 5 TO 8 DEGREES WARMER THAN NORMAL.
MODELS THEN SHOW STRONG HIGH PRESSURE SPREADING SOUTHEASTWARD FROM
THE CANADIAN PLAINS. THIS WILL PUSH A COLD FRONT SOUTHWARD THROUGH
THE UPPER OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE FRONT MAY
HAVE LITTLE MOISTURE TO INGEST, SO MAINTAINED A SLIGHT CHANCE OF
PREFRONTAL SHOWERS TUESDAY NIGHT, AND A CHANCE OF POSTFRONTAL SHOWERS
WEDNESDAY.
THE PRECIPITATION TYPE WILL BE A MIX OF RAIN AND SNOW, AS SURFACE
LAYER TEMPERATURES WILL STRADDLE THE FREEZING POINT. THIS IDEA IS
SUPPORTED BY RECENT GFS AND NAM MOS WHICH SHOW TEMPERATURES TO
LOWER TO SEASONABLE LEVELS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS A DEEP UPPER
LOW PASSING EASTWARD THROUGH EASTERN CANADA LATE WEEK. HENCE
EXPECT A COLD FRONT, WITH A MIX OF RAIN AND SNOW SHOWERS, TO PASS
THROUGH THE UPPER OHIO VALLEY AROUND FRIDAY. FOR NOW HAVE
CONTINUED FORECAST OF NEAR-SEASONABLE POSTFRONTAL TEMPERATURES FOR
SATURDAY. HOWEVER, RECENT NAEFS MEDIAN VALUES AND GFS MOS SUGGEST
TEMPERATURES SATURDAY COULD BECOME 5 TO 10 DEGREES COLDER THAN
NORMAL.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
DRY AIR WORKING IN FROM THE NORTH IS PROHIBITING MUCH FOG OR
STRATUS DEVELOPMENT EARLY THIS MORNING EXCEPT FOR KMGW AND THE
MOUNTAINS EAST. ANY PATCHY MVFR FOG WILL QUICKLY BURN OFF AFTER
SUNRISE. AS UPPER TROUGH EXITS EAST THIS MORNING FOG AND STRATUS
FROM MGW AND RIDGES WILL LIFT WITH REMAINING MID DECK QUICKLY
SHIFTING EAST. WINDS WILL BE LIGHT NORTHERLY INTO THE AFTERNOON.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
GENERAL VFR CONDITIONS ARE EXPECTED THROUGH TUESDAY. A SERIES OF
SHORT WAVES MAY BRING RESTRICTIONS AT TIMES IN SNOW SHOWERS
WEDNESDAY INTO THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
544 AM EST SUN FEB 5 2012
.SYNOPSIS...
ANY REMAINING MIX OF LIGHT RAIN AND SNOW ACROSS THE MOUNTAINS WILL
END THIS MORNING, AS UPPER LEVEL DISTURBANCE EXITS EAST. HIGH
PRESSURE, COMING EAST FROM THE PLAINS, WILL THEN FOLLOW TO BRING SUNHINE
BY AFTERNOON, AND AGAIN ON MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RECENT RADAR DATA TRENDS AND HRRR AND WRF-NMM MODEL OUTPUT
CONTINUE TO SHOW ANY LIGHT MIX OF RAIN AND WET SNOW WILL END
BEFORE MID-MORNING, AS AN UPPER LEVEL JETSTREAM MAX EXITS EAST.
THERE MAY BE A SMALL ACCUMULATION OF WET SNOW OVER THE HIGHER
MOUNTAINS.
RECENT SURFACE DATA SHOWS SIGNS THAT THE LOW CLOUDS RESULTING IN
FOG PATCHES OVER THE HIGHER PA-WV-MD MOUNTAINS, HAS BEGUN TO LIFT. SO
EXPECT ANY REMAINING HIGHER ELEVATION FOG TO HAVE ENDED BY 9 AM.
PER TRENDS IN RECENT SATELLITE DATA AND SUPPORT FROM RECENT HRRR
AND NAM MODEL OUTPUT, EXPECT CLOUDS TO ALSO DECREASE, NORTH TO
SOUTH, THIS MORNING, YIELDING A DECENT AMOUNT OF SUNSHINE BY AFTERNOON.
HAVE CONTINUED TO FINE TUNE TEMPERATURE FORECAST PER RECENT HRRR
AND GFS LAMP MODEL OUTPUT. EXPECT AFTERNOON HIGHS TO BE 2 TO 5
DEGREES WARMER THAN NORMAL, WHICH IS ALSO SUPPORTED BY RECENT NAM
AND GFS MOS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
BLEND OF RECENT SREF AND ECMWF MODEL OUTPUT SHOWS SPRAWLING HIGH
PRESSURE, EXTENDING FROM THE PLAINS TO THE APPALACHIANS, WILL
PROVIDE NO MORE THAN SCATTERED CLOUDS ACROSS THE UPPER OHIO VALLEY
TONIGHT INTO TUESDAY. THIS WILL MAINTAIN MILD CONDITIONS, WITH
LOWS AND HIGHS GENERALLY 5 TO 8 DEGREES WARMER THAN NORMAL.
MODELS THEN SHOW STRONG HIGH PRESSURE SPREADING SOUTHEASTWARD FROM
THE CANADIAN PLAINS. THIS WILL PUSH A COLD FRONT SOUTHWARD THROUGH
THE UPPER OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE FRONT MAY
HAVE LITTLE MOISTURE TO INGEST, SO MAINTAINED A SLIGHT CHANCE OF
PREFRONTAL SHOWERS TUESDAY NIGHT, AND A CHANCE OF POSTFRONTAL SHOWERS
WEDNESDAY.
THE PRECIPITATION TYPE WILL BE A MIX OF RAIN AND SNOW, AS SURFACE
LAYER TEMPERATURES WILL STRADDLE THE FREEZING POINT. THIS IDEA IS
SUPPORTED BY RECENT GFS AND NAM MOS WHICH SHOW TEMPERATURES TO
LOWER TO SEASONABLE LEVELS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS A DEEP UPPER
LOW PASSING EASTWARD THROUGH EASTERN CANADA LATE WEEK. HENCE
EXPECT A COLD FRONT, WITH A MIX OF RAIN AND SNOW SHOWERS, TO PASS
THROUGH THE UPPER OHIO VALLEY AROUND FRIDAY. FOR NOW HAVE
CONTINUED FORECAST OF NEAR-SEASONABLE POSTFRONTAL TEMPERATURES FOR
SATURDAY. HOWEVER, RECENT NAEFS MEDIAN VALUES AND GFS MOS SUGGEST
TEMPERATURES SATURDAY COULD BECOME 5 TO 10 DEGREES COLDER THAN
NORMAL.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
IFR CONDITIONS IN FOG AND STRATUS MAY REMAIN ACROSS KMGW AND THE
MOUNTAINS EAST INTO MID MORNING, AS LOW LEVEL MOISTURE FROM
PREVIOUS LIGHT MIXED PRECIPITATION WILL BE TRAPPED UNTIL SURFACE
HIGH CAN MIX BOUNDARY LAYER.
FARTHER NORTH, ACROSS THE KZZV-KPIT-KLBE CORRIDOR, HAVE LOWERING
CONFIDENCE THAT CURRENT MVFR VISIBILITY RESTRICTIONS BY FOG WILL
DETERIORATE TO IFR THIS MORNING. IF STRATUS FAILS TO DEVELOP,
VISIBILITIES WILL IMPROVE TO VFR BY LATE MORNING.
NORTHERN TERMINALS, KFKL AND KDUJ, WILL STAY VFR THROUGH PERIOD. WINDS
WILL BE LIGHT NORTHERLY INTO THE AFTERNOON.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
GENERAL VFR CONDITIONS ARE EXPECTED THROUGH TUESDAY. A SERIES OF
SHORT WAVES MAY BRING RESTRICTIONS AT TIMES IN SNOW SHOWERS
WEDNESDAY INTO THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
438 AM EST SUN FEB 5 2012
.SYNOPSIS...
ANY REMAINING MIX OF LIGHT RAIN AND SNOW WILL END THIS MORNING, AS
UPPER LEVEL DISTURBANCE EXITS EAST. HIGH PRESSURE WILL THEN FOLLOW
TO BRING SOME SUN BY AFTERNOON, AND AGAIN ON MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RECENT RADAR DATA TRENDS AND HRRR AND WRF-NMM MODEL OUTPUT
CONTINUE TO SHOW ANY LIGHT MIX OF RAIN AND WET SNOW WILL END
BEFORE MID-MORNING, AS AN UPPER LEVEL JETSTREAM MAX EXITS EAST.
THERE MAY BE A SMALL ACCUMULATION OF WET SNOW OVER THE HIGHER
MOUNTAINS.
RECENT SURFACE DATA SHOWS SIGNS THAT THE LOW CLOUDS RESULTING IN
AREAS OF FOG OVER THE HIGHER PA-WV-MD MOUNTAINS, HAS BEGUN TO
LIFT. SO EXPECT ANY REMAINING HIGHER ELEVATION FOG TO HAVE ENDED
BY 9 AM.
PER TRENDS IN RECENT SATELLITE DATA AND SUPPORT FROM RECENT HRRR
AND NAM MODEL OUTPUT, EXPECT CLOUDS TO ALSO DECREASE, NORTH TO
SOUTH, THIS MORNING, YIELDING A DECENT AMOUNT OF SUNSHINE THIS
AFTERNOON.
HAVE CONTINUED TO FINE TUNE TEMPERATURE FORECAST PER RECENT HRRR
AND GFS LAMP MODEL OUTPUT. EXPECT AFTERNOON HIGHS TO BE 2 TO 5
DEGREES WARMER THAN NORMAL, WHICH IS ALSO SUPPORTED BY RECENT NAM
AND GFS MOS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
BLEND OF RECENT SREF AND ECMWF MODEL OUTPUT SHOWS SPRAWLING HIGH
PRESSURE, EXTENDING FROM THE PLAINS TO THE APPALACHIANS, WILL
PROVIDE NO MORE THAN SCATTERED CLOUDS ACROSS THE UPPER OHIO VALLEY
TONIGHT INTO TUESDAY. THIS WILL MAINTAIN MILD CONDITIONS, WITH
LOWS AND HIGHS GENERALLY 5 TO 8 DEGREES WARMER THAN NORMAL.
MODELS THEN SHOW STRONG HIGH PRESSURE SPREADING SOUTHEASTWARD FROM
THE CANADIAN PLAINS. THIS WILL PUSH A COLD FRONT SOUTHWARD THROUGH
THE UPPER OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE FRONT MAY
HAVE LITTLE MOISTURE TO INGEST, SO MAINTAINED A SLIGHT CHANCE OF
PREFRONTAL SHOWERS TUESDAY NIGHT, AND A CHANCE OF POSTFRONTAL SHOWERS
WEDNESDAY.
THE PRECIPITATION TYPE WILL BE A MIX OF RAIN AND SNOW, AS SURFACE
LAYER TEMPERATURES WILL STRADDLE THE FREEZING POINT. THIS IDEA IS
SUPPORTED BY RECENT GFS AND NAM MOS WHICH SHOW TEMPERATURES TO
LOWER TO SEASONABLE LEVELS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOWS A DEEP UPPER
LOW PASSING EASTWARD THROUGH EASTERN CANADA LATE WEEK. HENCE
EXPECT A COLD FRONT, WITH A MIX OF RAIN AND SNOW SHOWERS, TO PASS
THROUGH THE UPPER OHIO VALLEY AROUND FRIDAY. FOR NOW HAVE
CONTINUED FORECAST OF NEAR-SEASONABLE POSTFRONTAL TEMPERATURES FOR
SATURDAY. HOWEVER, RECENT NAEFS MEDIAN VALUES AND GFS MOS SUGGEST
TEMPERATURES SATURDAY COULD BECOME 5 TO 10 DEGREES COLDER THAN
NORMAL.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
IFR CONDITIONS IN FOG AND STRATUS MAY REMAIN ACROSS KMGW AND THE
MOUNTAINS EAST INTO MID MORNING AS LOW LEVEL MOISTURE FROM
PREVIOUS LIGHT MIXED PRECIPITATION WILL BE TRAPPED UNTIL SURFACE
HIGH CAN MIX BOUNDARY LAYER.
FARTHER NORTH, ACROSS THE KZZV-KPIT-KLBE CORRIDOR, HAVE LOWERING
CONFIDENCE THAT CURRENT MVFR VISIBILITY RESTRICTIONS BY FOG WILL
DETERIORATE TO IFR THIS MORNING. IF STRATUS FAILS TO DEVELOP,
VISIBILITIES WILL IMPROVE TO VFR BY LATE MORNING.
NORTHERN TERMINALS, KFKL AND KDUJ, WILL STAY VFR THROUGH PERIOD. WINDS
WILL BE LIGHT NORTHERLY INTO THE AFTERNOON.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
GENERAL VFR CONDITIONS ARE EXPECTED THROUGH TUESDAY. A SERIES OF
SHORT WAVES MAY BRING RESTRICTIONS AT TIMES IN SNOW SHOWERS
WEDNESDAY INTO THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1247 AM EST SUN FEB 5 2012
.SYNOPSIS...
EASTBOUND UPPER LEVEL DISTURBANCE MAY PRODUCE A MIX OF LIGHT RAIN
AND SNOW OVERNIGHT FOR AREAS SOUTH OF PITTSBURGH. HIGH PRESSURE
WILL FOLLOW TO BRING SOME SUN SUNDAY AFTERNOON AND AGAIN ON MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
RECENT RADAR DATA TRENDS AND HRRR AND WRF-NMM MODEL OUTPUT
CONTINUE TO SHOW AN UPPER LEVEL JETSTREAM MAX WILL CAUSE A LIGHT
MIX OF RAIN AND SNOW OVERNIGHT, UNTIL IT EXITS EAST SUNDAY
MORNING. THERE MAY BE A SMALL ACCUMULATION OF WET SNOW OVER THE
HIGHER MOUNTAINS.
RECENT SURFACE DATA SHOWS LOW CLOUDS RESULTING IN AREAS
OF FOG OVER THE HIGHER PA-WV-MD MOUNTAINS, WHICH NAM MODEL
PROFILES SHOW MAY NOT LIFT UNTIL SUNDAY MORNING.
ADJUSTED TEMPERATURES OVERNIGHT 1-2 DEGREES WARMER, BASED ON
RECENT HRRR AND GFS LAMP MODEL OUTPUT. EXPECTING LEFTOVER LOW CLOUDS
SUNDAY MORNING, HAVE SLOWED WARM UP, AND HAVE ALSO CUT HIGHS
SUNDAY AFTERNOON BY 1-2 DEGREES, WHICH HAS SOME SUPPORT FROM
RECENT GFS LAMP.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
DRY WEATHER AND ABOVE NORMAL TEMPERATURES ARE FORECAST FOR THE
SHORT TERM AS A WEAK RIDGE ALOFT SLIDES EASTWARD OVER THE REGION
AND A SURFACE HIGH BUILDS INTO THE UPPER OHIO VALLEY. MAXIMUM
TEMPERATURES SHOULD REACH WELL INTO THE 40S MONDAY AFTERNOON AND
RANGE FROM THE UPPER 30S TO MID 40S TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
A SERIES OF SHORT WAVES THROUGH THE EXTENDED PERIOD WILL
BRING UNSETTLED WEATHER WITH A CHANCE OF RAIN OR SNOW SHOWERS EACH
DAY. THE TEMPERATURES WILL BE NEAR OR A BIT ABOVE NORMAL THROUGH
THE PERIOD. THE SYSTEMS WILL BE MOVING RAPIDLY IN THE WEAK WEST
NORTHWEST FLOW ALOFT WITH LITTLE AVAILABLE MOISTURE. AS A RESULT
PRECIPITATION WILL BE LIMITED THROUGH THE PERIOD.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
IFR CONDITIONS IN FOG AND STRATUS EXPECTED INTO MID MORNING FROM
PITTSBURGH SOUTH AS LOW LEVEL MOISTURE FROM PREVIOUS MELTED SNOWFALL
WILL BE TRAPPED ACROSS REGION UNTIL SURFACE HIGH CAN MIX BOUNDARY
LAYER. CURRENT MVFR AT KPIT AND KAGC SHOULD DETERIORATE BY 08Z TO
IFR OR LOWER.
NORTHERN TERMINALS WILL STAY VFR THROUGH PERIOD. BIT OF MIXED
RAIN AND SNOW WILL PASS REGION EARLY AS UPPER LEVEL TROUGH CROSSES
REGION. HIGH PRESSURE RIDGE WILL BUILD ACROSS FROM THE WEST BY
MIDDAY WITH ENOUGH MIXING TO BRING ALL SITES TO VFR. WINDS WILL BE
LIGHT NORTHERLY INTO THE AFTERNOON.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...
GENERAL VFR CONDITIONS ARE EXPECTED THROUGH TUESDAY. A SERIES OF
SHORT WAVES MAY BRING RESTRICTIONS AT TIMES IN SNOW SHOWERS
WEDNESDAY INTO THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
400 PM EST SUN FEB 5 2012
LATEST UPDATE...ALL EXCEPT AVIATION...
.SYNOPSIS...(400 PM EST SUN FEB 5 2012)
FAIRLY QUIET WEATHER CONDITIONS WILL CONTINUE INTO EARLY THIS
WEEK...WITH A WARMER THAN NORMAL DAY EXPECTED MONDAY. AFTER SOME
MORNING CLOUDS...WE SHOULD SEE SUNSHINE THAT WILL BOOST TEMPERATURES
WELL INTO THE 40S. A COLD FRONT WILL SLIP SOUTH THROUGH THE STATE
MONDAY NIGHT WHICH WILL FILTER COLDER AIR IN FOR MID WEEK. LITTLE IN
THE WAY OF PRECIPITATION IS EXPECTED THROUGH THURSDAY. EVEN COLDER
AIR MOVES IN FOR LATE IN THE WEEK WITH SOME LAKE EFFECT SNOW SHOWERS
AS WELL. HIGHS WILL BE BACK DOWN IN THE 30S FOR MID WEEK AND IN THE
20S BY FRIDAY.
&&
.SHORT TERM...(400 PM EST SUN FEB 5 2012)
(TONIGHT THROUGH TUESDAY NIGHT)
CLOUDS HAVE BEEN THE FOCUS OF THE SHORT TERM FOR DAYS AND TODAY IS
NO EXCEPTION. A BATCH OF STRATUS IS LOCATED OVER LAKE MICHIGAN THIS
AFTERNOON...AND FEEL IT...ALONG WITH CLOUDS/MOISTURE UPSTREAM WILL
ADVECT INTO THE FORECAST AREA FROM THE WEST. ESSENTIALLY ENVISION A
GRADUAL EXPANSION TO THE EAST OF THE CLOUDS OVER THE LAKE AND POINTS
FURTHER WEST. RUC HAS SOMEWHAT OF A HANDLE ON THIS AND SEE NO REASON
TO ARGUE AT THIS POINT. THE STRATUS LATELY HAS BEEN PROBLEMATIC
THOUGH AND CONFIDENCE IS NOT HIGH IN ITS EVOLUTION. LOOKING FOR
MORNING CLOUDS TO LIFT WITH A FAIR AMOUNT OF SUNSHINE ON MONDAY.
HIGH SHOULD BE WELL ABOVE NORMAL IN THE 40S.
A COLD FRONT WILL DROP SOUTH THROUGH THE AREA MONDAY NIGHT. MOISTURE
DEPTH IS EXTREMELY SHALLOW...SO EXPECTING IT TO COME THROUGH FOR THE
MOST PART DRY. DO HAVE A FEW SNOW SHOWERS IN NORTHERLY FLOW ACROSS
THE NORTHWEST CORNER OF THE FORECAST AREA MONDAY NIGHT/TUESDAY
MORNING AS DELTA T/S CREEP ABOVE 13 DEGREES C. BY TUESDAY AFTERNOON
THOUGH THE FLOW IS TRENDING NORTHEAST/OFF SHORE. LOWER TROP DRIES
OUT FROM THE NORTH TUESDAY NIGHT DESPITE LAKE INSTABILITY. OVERALL
DRY CONDITIONS TUESDAY NIGHT WITH DECREASING CLOUDS.
&&
.LONG TERM...(400 PM EST SUN FEB 5 2012)
(WEDNESDAY THROUGH SUNDAY)
MAIN FOCUS OF THE FCST IN THE LONG TERM IS ON THE LAKE EFFECT
POTENTIAL FOR THE END OF THE WORK WEEK AND THE FIRST PORTION OF NEXT
WEEKEND.
IT APPEARS THAT WE SHOULD END UP IN BETWEEN SYSTEMS AT THE BEGINNING
OF THE LONG TERM ON WED. THERE WILL BE A SHORT WAVE MISSING THE AREA
TO THE SOUTH AND THERE WILL BE A WAVE THAT WILL BE GETTING READY TO
DROP SE ON THE SRN PERIPHERY OF THE POLAR VORTEX CENTERED ACROSS
HUDSON BAY. THIS WILL PLACE THE AREA UNDER SHORT WAVE RIDGING AND
DRY AND COOLER AIR.
THE MODELS ARE INDICATING THAT STRONG SHORT WAVE ENERGY COMING FROM
NRN CANADA SHOULD BE THE CAUSE FOR A COLD FRONT MOVING INTO THE AREA
LATER ON THU FROM THE NORTH. THIS WILL BE RESPONSIBLE FOR BRINGING
IN A GLANCING BLOW OF ARCTIC AIR TO THE AREA. H850 TEMPS WILL DROP
INTO THE NEGATIVE UPPER TEENS C. UPPER CYCLONIC FLOW WILL SETTLE IN
FOR FRI AND INTO SAT...AND WILL BRING THE POTENTIAL FOR LAKE EFFECT.
LAKE EFFECT PARAMETERS DO NOT LOOK FAVORABLE FOR A BIG EVENT.
MOISTURE DOES NOT LOOK VERY FAVORABLE MOST OF THE TIME...EXCEPT
MAYBE DECENT FRI MORNING. THERE IS EVEN POTENTIAL PER THE NEW 12Z
EURO WHERE THE FLOW WOULD END UP FROM THE NE...AND WE WOULD SEE
LITTLE IF ANY LAKE EFFECT. STILL A LOT OF DETAILS TO IRON OUT.
MODELS ARE ALL IN GOOD AGREEMENT IN THE CYCLONIC FLOW LIFTING OUT BY
SUN MORNING. THIS LOOKS TO OCCUR AS THE AMPLIFIED RIDGE OVER WRN
CANADA THAT HELPS TO SEND THE ARCTIC AIR DOWN GETS FLATTENED BY A
STRONG PACIFIC JET EXPECTED TO MOVE OVER THE PACIFIC NW. THIS SHOULD
SHIFT OUR FLOW TO A MORE MILD AND ZONAL PATTERN OFF OF THE PACIFIC
LATE NEXT WEEKEND.
&&
.AVIATION...(1254 PM EST SUN FEB 5 2012)
THE MAIN CHALLENGE WITH THE 18Z SET OF TERMINALS IS THE LOW CLOUD
COVER IN PLACE OVER THE REGION. A MVFR CLOUD DECK BASED AROUND
2000-2500 FT EXISTS NW OF A LINE FROM ROUGHLY KORD TO KMKG TO CLARE.
THIS CLOUD COVER IS LIKELY DUE TO SFC RIDGING OVER THE AREA LAST
NIGHT COMBINED WITH SOME MELTING SNOW. THE CLOUDS HAVE NOT BEEN
MOVING MUCH WITH A LIGHT WIND...AND THEY ARE STARTING TO MIX OUT
SOME. SOME DIURNAL CUMULUS IS DEVELOPING TOWARD KLAN...AND THIS
SHOULD BRING SOME TEMPO CIGS AROUND 2500 FT.
QUITE AN UNCERTAIN FCST RIGHT NOW...AND THE MODELS ARE STRUGGLING
WITH THE CURRENT PLACING OF THE CLOUD COVER. WE EXPECT SOME OF THESE
CLOUDS TO MIX OUT THROUGH DIURNAL PROCESSES...THOUGH HOW MUCH IS IN
QUESTION. THE CLOUDS TO OUR WEST SHOULD EVENTUALLY GET ADVECTED TO
THE EAST WITH AN INCREASING WRLY FLOW EXPECTED TO TAKE SHAPE THIS
EVENING. THIS FLOW COULD MIX THESE CLOUDS OUT...AND THERE ARE LITTLE
TO NO IMPACTS. THEY ALSO COULD GET ADVECTED IN BY THE WINDS...AND
PRODUCE MUCH MORE IMPACT. THE AREAS THAT WOULD BE AFFECTED THE MOST
WOULD BE KMKG AND KGRR...BUT WE CAN NOT RULE OUT THE OTHER TERMINALS
BEING AFFECTED. WE HAVE GONE SOMEWHAT OPTIMISTIC FOR NOW...AND JUST
HAVING A SCT025 DECK TONIGHT FOR THE NRN TERMINALS. AS TRENDS BECOME
MORE EVIDENT THROUGH THE AFTERNOON...WE CAN PIN DOWN THE DETAILS
WITH THE 00Z TERMINALS.
ONE OTHER THING TO MENTION IS W/SW WINDS WILL INCREASE MON MORNING
TO AROUND 12 KNOTS OR SO WITH SOME HIGHER GUSTS LIKELY.
&&
.MARINE...(400 PM EST SUN FEB 5 2012)
HOISTED A SMALL CRAFT ADVISORY FROM OVERNIGHT THROUGH THE DAY ON
MONDAY. WESTERLY WINDS PICK UP TONIGHT AHEAD OF A COLD FRONT THAT
WILL BE DROPPING SOUTH INTO THE GREAT LAKES REGION ON MONDAY. ONLY
RAN THE ADVISORY THROUGH MONDAY EVENING AT THIS POINT TO SEE EXACTLY
HOW THE WINDS ARE GOING TO PLAY OUT POST FROPA. IT APPEARS THOUGH
THAT THE ADVISORY WILL NEED TO BE EXTENDED INTO MONDAY NIGHT AND
TUESDAY AS WELL AS THE WAVE FIELD...EVEN IN NORTHEAST
FLOW...PROPAGATES INTO OUR NEARSHORE WATERS.
&&
.HYDROLOGY...(400 PM EST SUN FEB 5 2012)
RIVER FLOOD ADVISORIES FOR IONIA AND BURLINGTON HAVE BEEN DROPPED IN
THE PAST 24 HOURS...WITH VICKSBURG THE ONLY ONE REMAIN. LIMITED
HYDRO CONCERNS THE NEXT FEW DAYS WILL LITTLE IN THE WAY OF
PRECIPITATION EXPECTED.
RIVER ICE WILL LIKELY BECOME MORE OF A CONCERN FROM MID WEEK INTO
NEXT WEEKEND AS WE ARE FORECAST TO COOL OFF.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY ST. JOE TO MANISTEE OVERNIGHT THROUGH
MONDAY.
&&
$$
SYNOPSIS: DUKE
SHORT TERM: DUKE
LONG TERM: NJJ
AVIATION: NJJ
MARINE: DUKE
HYDROLOGY: DUKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1254 PM EST SUN FEB 5 2012
LATEST UPDATE...AVIATION...
.SYNOPSIS...(402 AM EST SUN FEB 5 2012)
MILD WEATHER WILL CONTINUE TODAY AND MONDAY WITH HIGHS MAINLY IN THE
LOW TO MID 40S EACH DAY. IT WILL ALSO REMAIN DRY TROUGH MONDAY.
CHANGES WILL BEGIN MONDAY NIGHT AS A COLD FRONT BRINGS COOLER AIR
INTO THE REGION THAT WILL LAST INTO MID WEEK. TEMPERATURES WILL BE
CLOSER TO NORMAL VALUES FOR MID WEEK...HOWEVER ANY SNOWFALL WILL BE
LIMITED. ANOTHER COLD FRONT AND AN ENFORCING SHOT OF COLD AIR
SHOULD ARRIVE THURSDAY NIGHT AND LAST INTO NEXT WEEKEND. SOME LAKE
EFFECT SNOW SHOWERS ARE EXPECTED IN THIS COLDER REGIME.
&&
.SHORT TERM...(1140 AM EST SUN FEB 5 2012)
(TODAY THROUGH TUESDAY)
MADE SMALL MODIFICATIONS TO THE GOING FORECAST...SPECIFICALLY CLOUD
COVER IN THE NORTHWEST CORNER OF THE FORECAST AREA. IT APPEARS MOST
LOCATIONS ACROSS THE AREA WILL SEE MOSTLY SUNNY SKIES...THE
EXCEPTION BEING THE NORTHWEST TOWARD LUDINGTON. MODEL LOW LEVEL RH
IS NOT DOING A GOOD JOB DEPICTING THE STRATUS. THE RUC HAS A
CLUE...BUT IT IS NOT PINPOINTING AREAS THAT ARE MOSTLY CLOUDY
EITHER. IN GENERALLY HAVE A VERY SLOW EROSION OF THE CLOUD COVER UP
THERE THROUGH SUNSET...WHICH HAS YIELDED A MOSTLY CLOUDY WORDING IN
THE FAR NORTHWEST AND BECOMING PARTLY SUNNY ELSEWHERE. NOSED HIGH
TEMPS DOWN A TAD UP THERE AS WELL GIVEN THE CLOUDS.
PREVIOUS DISCUSSION FOLLOWS...
UNEVENTFUL WEATHER CONTINUES TONIGHT AND MONDAY. ABUNDANT SUNSHINE
ON MONDAY SHOULD BOOST TEMPS INTO THE 40S AGAIN.
CLOUDS WILL BE ON THE INCREASE MONDAY EVENING AS AN ARCTIC FRONT
DROPS SOUTH ACROSS THE CWA. MOISTURE LOOKS RATHER LIMITED INITIALLY
WITH THIS FRONT...SO ONLY EXPECTING TO SEE A FEW FLURRIES AS THE
FRONT COMES IN. TEMPS BEHIND THE FRONT FOR TUESDAY SHOULD ONLY
REACH THE UPPER 20S TO MID 30S...OR NEAR NORMAL VALUES. THE MODELS
ARE TRENDING TO SHOW DEEPER MOISTURE ARRIVING ALONG THE FRONT WITH A
SHORT WAVE CROSSING THE LOWER GREAT LAKES INTO TUESDAY. THIS STILL
DOES NOT LOOK OVERLY IMPRESSIVE...BUT AS THESE FEATURES COME
TOGETHER THE SOUTHERN HALF OF THE CWA COULD SEE A DUSTING OF SNOW ON
TUESDAY. HAVE ADDED LOW CHC POPS TO THIS AREA FOR NOW.
&&
.LONG TERM...(402 AM EST SUN FEB 5 2012)
(TUESDAY NIGHT THROUGH SATURDAY)
NO BIG STORMS IN THE EXTENDED BUT SOME SNOW SHOWERS ARE POSSIBLE AS
ARCTIC AIR RETURNS THURSDAY NIGHT AND FRIDAY.
MODELS HAVE TRENDED WEAKER AND FURTHER SOUTH WITH A WAVE ALONG THE
ARCTIC FRONT ON WEDNESDAY/WEDNESDAY NIGHT AND IT APPEARS THIS
FEATURE WILL NOT HAVE MUCH EFFECT ON THE LOCAL WEATHER. SNOW SHOWERS
SHOULD INCREASE BY THURSDAY AS CLIPPER MOVES ACROSS NORTHERN LOWER
MICHIGAN WITH CYCLONIC FLOW CONTINUING INTO FRIDAY. INVERSION
HEIGHTS ARE BELOW 10 KFT THROUGH THE EVENT SO A WIDESPREAD HEAVY
LAKE EFFECT SNOW IS NOT EXPECTED.
&&
.AVIATION...(1254 PM EST SUN FEB 5 2012)
THE MAIN CHALLENGE WITH THE 18Z SET OF TERMINALS IS THE LOW CLOUD
COVER IN PLACE OVER THE REGION. A MVFR CLOUD DECK BASED AROUND
2000-2500 FT EXISTS NW OF A LINE FROM ROUGHLY KORD TO KMKG TO CLARE.
THIS CLOUD COVER IS LIKELY DUE TO SFC RIDGING OVER THE AREA LAST
NIGHT COMBINED WITH SOME MELTING SNOW. THE CLOUDS HAVE NOT BEEN
MOVING MUCH WITH A LIGHT WIND...AND THEY ARE STARTING TO MIX OUT
SOME. SOME DIURNAL CUMULUS IS DEVELOPING TOWARD KLAN...AND THIS
SHOULD BRING SOME TEMPO CIGS AROUND 2500 FT.
QUITE AN UNCERTAIN FCST RIGHT NOW...AND THE MODELS ARE STRUGGLING
WITH THE CURRENT PLACING OF THE CLOUD COVER. WE EXPECT SOME OF THESE
CLOUDS TO MIX OUT THROUGH DIURNAL PROCESSES...THOUGH HOW MUCH IS IN
QUESTION. THE CLOUDS TO OUR WEST SHOULD EVENTUALLY GET ADVECTED TO
THE EAST WITH AN INCREASING WRLY FLOW EXPECTED TO TAKE SHAPE THIS
EVENING. THIS FLOW COULD MIX THESE CLOUDS OUT...AND THERE ARE LITTLE
TO NO IMPACTS. THEY ALSO COULD GET ADVECTED IN BY THE WINDS...AND
PRODUCE MUCH MORE IMPACT. THE AREAS THAT WOULD BE AFFECTED THE MOST
WOULD BE KMKG AND KGRR...BUT WE CAN NOT RULE OUT THE OTHER TERMINALS
BEING AFFECTED. WE HAVE GONE SOMEWHAT OPTIMISTIC FOR NOW...AND JUST
HAVING A SCT025 DECK TONIGHT FOR THE NRN TERMINALS. AS TRENDS BECOME
MORE EVIDENT THROUGH THE AFTERNOON...WE CAN PIN DOWN THE DETAILS
WITH THE 00Z TERMINALS.
ONE OTHER THING TO MENTION IS W/SW WINDS WILL INCREASE MON MORNING
TO AROUND 12 KNOTS OR SO WITH SOME HIGHER GUSTS LIKELY.
&&
.MARINE...(402 AM EST SUN FEB 5 2012)
A LIGHT NW WIND IS EXPECTED OVER THE LAKE TODAY. WAVES WILL BE ON
THE LOW SIDE. BUT BY LATE TONIGHT WEST WINDS WILL BE INCREASING
AHEAD OF THE ARCTIC FRONT. WE MAY NEED A SCA LATE TONIGHT OR AT
LEAST BY EARLY MONDAY TO ACCOUNT FOR THE INCREASING WINDS AND
WAVES. THE COLD ADVECTION BEHIND THE FRONT WILL LIKELY KEEP WAVES
ON THE HIGHER SIDE INTO MONDAY NIGHT.
&&
.HYDROLOGY...(402 AM EST SUN FEB 5 2012)
LIMITED HYDRO CONCERNS THROUGH THE SHORT TERM DUE TO MINIMAL PCPN.
SNOW MELT OVER THE NORTHERN CWA WILL CONTINUE...BUT THIS WILL NOT
PUSH RIVERS OUT OF THEIR BANKS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: JK
SHORT TERM: JK/DUKE
LONG TERM: OSTUNO
AVIATION: NJJ
MARINE: JK
HYDROLOGY: JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1247 PM EST SUN FEB 5 2012
UPDATED AVIATION DISCUSSION FOR THE 18Z TAFS
.SYNOPSIS... ISSUED AT 434 AM EST
00Z RAOBS SHOW DECAYING UPR LOW OVR KS/MO WHILE LARGER SCALE RIDGE
IS LOCATED FM WEST CONUS INTO WESTERN CANADA. PRIMARY TROUGHING IS
ORIENTED FM NORTHERN CANADA INTO QUEBEC AND NEW BRUNSWICK. COLDEST
AIR BY FAR IS LOCATED OVR FAR NORTHERN SECTIONS OF CANADA IN VCNTY
OF POLAR VORTEX. OTHERWISE...MOST OF CANADA AND THE CONUS FOR THAT
MATTER IS AWASH IN CONTINUAL FLOW OF MILD PACIFIC AIR. THIS WEEK
RIDGE IS EXPECTED TO BECOME MORE MERIDIONAL FM WESTERN CONUS INTO
ALASKA. RESULT IS EASTERN CANADA TROUGH TO SETTLE TOWARD GREAT LAKES
AND NORTHEAST CONUS. FIRST PUSH OF COOLER AIR ARRIVES ACROSS UPR
LAKES LATE MONDAY INTO TUESDAY. ANOTHER SHOT OF MUCH COLDER AIR IS
POSSIBLE LATE THIS WEEK INTO FIRST PART OF NEXT WEEKEND AS PORTION
OF POLAR VORTEX TRIES TO DISLODGE AND COME INTO THE CONUS. PATTERN
DOES NOT SUGGEST MUCH IN WAY OF OPPORTUNITY FOR LARGE SCALE WINTER
SYSTEMS. MAIN SNOWFALL THROUGH PERIOD WILL COME VIA LK EFFECT.
&&
.SHORT TERM /TODAY THROUGH MONDAY NIGHT/... ISSUED AT 434 AM EST
IN THE NEAR TERM...SFC RIDGE OVR PLAINS BEGINS TO EXPAND INTO UPR
LAKES. RUC13 HAS MUCH BETTER HANDLE ON CURRENT STRATUS THAN 00Z
NAM. PER RUC13 OUTPUT AND RAOBS...MOISTURE ADVECTION IN THE CLOUD
BEARING LAYER IS NEUTRAL SO EXPECT STRATUS BASED AROUND 925MB TO
PERSIST OVR CNTRL AND EASTERN CWA. TEMPS WILL REMAIN IN THE UPR 20S
TO LOWER 30S...EXCEPT STAYING IN THE TEENS OVR FAR WEST.
TODAY AND TONIGHT...EXPECT STRATUS TO CLEAR FM WEST TO EAST THIS
MORNING AS 925MB WINDS TURN WESTERLY ALLOWING LOWER 925MB DWPNTS TO
ADVECT INTO UPR LAKES. ONCE LOW CLOUDS DEPART...MIXING HEIGHTS BUILD
BENEATH MOSTLY SUNNY SKIES /THOUGH MAY SEE SCT-BKN MID CLOUDS INTO
EARLY AFTN NCNTRL AND EAST BASED ON CURRENT TRAJECTORIES OF CLOUDS
DROPPING ACROSS ONTARIO/. MODEL PROFILES FM BUFKIT INDICATE MIXING
ONLY TO 925MB BUT GIVEN EXPECTED INSOLATION...AND SEEING THAT LOW-
LEVELS MIXED AOA 900MB ON SATURDAY PER KGRB 00Z SOUNDING...WILL OPT
FOR MORE MIXING AND HIGHER TEMPS. BLEND OF 900MB-850MB MIXING HEIGHT
SUPPORTS HIGHS WELL INTO THE 40S AND MAYBE EVEN NEAR 50 DEGREES...
ESPECIALLY IN DOWNSLOPE AREAS OF CNTRL CWA /BARAGA TO MARQUETTE AND
SOUTH TO ESCANABA AND MENOMINEE/. BASED ON HOW WARM TEMPS WERE
YDY...MAY COME CLOSE TO THE RECORD HIGH OF 50 DEGREES FOR WFO
MARQUETTE /2005/. THE WARM DAY WILL TRANSLATE TO WELL ABOVE NORMAL
TEMPS FOR TONIGHT. WARMING WILL BE MOST PRONOUNCED NEAR LK SUPERIOR
SHORE WITH WEST WINDS STIRRING ALL NIGHT AHEAD OF COLD FRONT
APPROACHING FM THE NORTH. BASED ON UPSTREAM READINGS THIS MORNING
AHEAD OF COLD FRONT...WINDS MAY STILL BECOME LIGHT IN THE INTERIOR SO
KEPT LOWS AROUND 20F INLAND WEST.
MONDAY...COLD FRONT REACHES KEWEENAW BTWN 15-18Z...THEN SWINGS
THROUGH FM NORTH TO SOUTH THROUGH THE DAY OVR REST OF CWA. RETAINED
FALLING TEMP IDEA FM PREVIOUS SHIFT...ESPECIALLY OVER THE NORTH HALF
OF THE CWA IN THE AFTN. WEST FLOW AND H9 TEMPS NEAR 0C AHEAD OF FRONT
SHOULD ALLOW TEMPS OVR FAR SCNTRL TO CLIMB INTO THE LOW 40S AT KMNM...
BEFORE FALLING OFF INTO THE LOWER 30S LATE. TEMPS WILL FALL FM THE
LOWER 30S INTO THE LOWER 20S BY SUNSET OVR REST OF THE CWA. SEEMS
THAT PCPN CHANCES WILL BE FAIRLY LIMITED UNTIL MONDAY NIGHT. FCST
SOUNDINGS FM NAM/GFS SUGGEST INCREASING STRATOCU CLOUDS MORE THAN
ANYTHING ELSE. MOIST LAYER FCST TO REACH -10C LATE AFTN INTO EARLY
EVENING SO COULD SEE SNOW GRAINS OR FLURRIES LATE IN THE DAY OVR
HIGHER TERRAIN OF NW CWA.
MONDAY NIGHT...COOLING CONTINUES AT 925-850MB WITH FCST SOUNDINGS
INDICATING MOISTURE THROUGH AROUND 5KFT BY 06Z-12Z IN A WEAKLY
CYCLONIC NORTHERLY FLOW REGIME. UNIDIRECTIONAL FLOW THROUGH
850MB/5KFT WITH WIND SPEEDS LESS THAN 20 KTS SHOULD HELP LK EFFECT
ORGANIZE LATE EVENING INTO OVERNIGHT HOURS. DESPITE SUBSIDENCE/DRYING
ABOVE INVERSION AT H85...MAJORITY OF LAKE CONVECTIVE LAYER IS WITHIN
MOST IDEAL SNOW DENDRITIC GROWTH ZONE WITH TEMPS -12C TO -18C. ECMWF
IS ON THE WARM END WHILE CANADIAN INDICATES H85 TEMPS DOWN NEAR -20C
BY LATE MONDAY NIGHT. CERTAINLY HAVE SEEN MORE IMPRESSIVE LK EFFECT
SETUP BUT DOES SEEM THAT NRLY WINDS...LOW-LEVEL CONVERGENCE...AND
FAVORABLE MOISTURE WITHIN THE DGZ JUSTIFIES INCREASING POPS OVR FAR
WEST AND ALSO OVR MUCH OF MARQUETTE AND ALGER COUNTIES. A FEW INCHES
OF SNOW IS NOT OUT OF QUESTION MONDAY NIGHT AIDED BY HIGH SLR/S AND
INCREASING FLUFFINESS TO THE SNOW. EXPECT MINS INTO THE SINGLE
DIGITS OVR THE INTERIOR WEST WITH READINGS IN THE TEENS FOR OTHER
AREAS.
.LONG TERM /12Z TUE THRU SAT/...
TUE...ALTHOUGH A SHRTWV WL BE PUSHING THRU THE UPR GRT LKS ON TUE
MRNG FOLLOWING THE SHARP COLD FROPA MON NGT...LATEST MODELS RUNS
HAVE CONTINUED TREND TOWARD RISING HGTS SHARPLY IN THE AFTN WITH
VIGOROUS DNVA/DEEP LYR QVECTOR CNVGC/SUBSIDENCE IN THE WAKE OF THE
SHRTWV PASSAGE RESULTING IN SHARP ACYC FLOW BY 00Z WED. ONGOING LES
OVER MAINLY THE N WIND SN BELTS IN THE MRNG WITH H85 TEMPS FCST BTWN
-14C BY THE ECMWF TO AS LO AS -20C BY THE CNDN MODEL WL SUPPORT
LIKELY POPS IN THE FAVORED SN BELTS WITH INVRN HGTS ARND 4K FT AGL
AT 12Z. BUT THE SHSN WL TEND TO DIMINISH STEADILY THRU THE DAY
ESPECIALLY OVER THE W AS H85 TEMPS ARE FCST TO RISE UP AS HI AS -10C
BY THE ECMWF BY 00Z WED. THE 00Z GFS INDICATES THE STRONG SUBSIDENCE
WL CAUSE THE INVRN BASE TO SINK TO 2K FT AGL BY 00Z WED...ENDING ANY
SGNFT SHSN BY LATE IN THE DAY AS PWAT SINKS BLO 0.10 INCH.
TUE NGT...UNDER RISING HGTS...SHRTWV RDG IS PROGGED TO BLD SLOWLY
THRU THE UPR GRT LKS. WITH PWAT FCST AS LO AS 0.10 INCH/MOCLR SKIES
AND LGT WINDS...EXPECT TEMPS OVER THE INTERIOR SCNTRL TO SINK AOB
THE LO END OF GUIDANCE. READINGS NEAR LK SUP WL BE BUOYED A BIT BY A
STRONGER W WIND TO THE N OF THE SFC RDG AXIS ORIENTED THRU NRN WI
INTO NRN LWR MI.
EXTENDED...HI PRES RDG WL DROP INTO THE OH VALLEY ON WED WITH A DRY
WLY FLOW DOMINATING AND TEMPS A BIT ABV NORMAL. NEXT SHRTWV WL
IMPACT THE UPR LKS ON THU. THE 00Z GFS/CNDN MODELS ARE IN FAIRLY
GOOD AGREEMENT SHOWING A STRONGER DISTURBANCE/SFC LO MOVING THRU THE
UPR LKS. WHILE THE 12Z ECMWF RUN SHOWED A SIMILAR SCENARIO...THE 00Z
RUN HAS BACKED OFF ON THE INTENSITY OF THIS DISTURBANCE...CONTINUING
A TREND OF MODEL INCONSISTENCIES ON THE HANDLING OF THIS SHRTWV. SO
WENT NO HIER THAN CHC POPS FOR SN ON THU. WITH THE ARRIVAL OF COLDER
AIR IN THE WAKE OF THE SHRTWV PASSAGE /H85 TEMPS AS LO AS -26C PER
THE 00Z GFS BUT ONLY -20C PER THE ECMWF/... EXPECT LES MAINLY IN THE
NW WIND SN BELTS INTO FRI NGT. THE ARRIVAL OF HI PRES ON SAT WL
CAUSE THE LES TO DIMINISH. EXPECT TEMPS TO RUN AOB NORMAL THU NGT
INTO SAT.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
VFR CONDITIONS SHOULD PREVAIL AT KIWD/KCMX/KSAW THRU TONIGHT AS VERY
SHALLOW LOW-LEVEL MOISTURE IN THE REGION CONTINUES TO MIX OUT
GRADUALLY. HOWEVER...THERE IS SOME CONCERN THAT STRATUS/FOG IN MN
COULD HANG ON THRU THE AFTN AND THEN EXPAND EASTWARD UNDER WESTERLY
LOW-LEVEL WINDS AFTER SUNSET. WILL BE SOMETHING TO MONITOR THIS
EVENING. TIGHTER PRES GRADIENT BTWN HIGH PRES SINKING S THRU THE
PLAINS AND A COLD FRONT DROPPING S INTO NRN ONTARIO WILL RESULT IN
LLWS TONIGHT AS SFC WINDS WILL BE DECOUPLED. FAVORABLE WRLY FLOW MAY
KEEP WINDS GUSTY AT KCMX...SO LLWS LESS LIKELY THERE. COLD FRONT
WILL PASS THRU THE TAF SITES MON MORNING...BRINGING MVFR CLOUD DECK
AND PROBABLY SOME FLURRIES OR -SHSN.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
NORTHERLY WINDS TURN WEST AND INCREASE TO 30 KTS THIS AFTERNOON AND
EVENING AHEAD OF COLD FRONT DROPPING SOUTH ACROSS ONTARIO. MAY SEE
GALE GUSTS TO 35 KTS DUE TO COASTAL CONVERGENCE ALONG TIP OF
KEWEENAW PENINSULA. WINDS BECOME NORTHERLY ON MONDAY AFTERNOON IN
WAKE OF COLD FRONT. GALE GUSTS TO 35 KTS POSSIBLE MONDAY EVENING
OVER NORTH AND EAST...BUT THEN WINDS DIMINISH TO LESS THAN 25 KTS
LATER MONDAY NIGHT AS HIGH PRESSURE RIDGE QUICKLY BUILDS INTO UPR
LAKES REGION. A RISK OF HEAVY FREEZING SPRAY MONDAY NIGHT OVR
NORTHERN SECTIONS AS TEMPS DROP TOWARD ZERO.
THE ARRIVAL OF THE HI PRES RDG WILL CAUSE DIMINISING WINDS ON
TUE/TUE NIGHT...BUT A STRONGER WSW FLOW UP TO 25-30 KTS WILL DEVELOP
ON WED AS THIS RDG SINKS TO THE S. THE HIGHEST WINDS ARE MOST LIKELY
BETWEEN THE KEWEENAW AND ISLE ROYALE WHERE TERRAIN INFLUENCES TEND
TO ENHANCE THIS FLOW. FOLLOWING THE PASSAGE OF A LO PRES ON THU...
PLAN ON A STRONGER NNW FLOW OF COLDER AIR. THERE ARE MODEL
DIFFERENCES ON THE FORECAST INTENSITY OF THIS LO...AND GALES WOULD
NOT BE OUT OF THE QUESTION IF THE DEEPER SCENARIO VERIFIES. WITH THE
POTENTIAL ARRIVAL OF MUCH COLDER AIR...HEAVY FREEZING SPRAY MAY
IMPACT PORTIONS OF THE LAKE ON THU...ESPECIALLY THE NCENTRAL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...NONE.
LAKE SUPERIOR...NONE.
LAKE MICHIGAN...NONE.
&&
$$
SYNOPSIS...JLA
SHORT TERM...JLA
LONG TERM...KC
AVIATION...ROLFSON
MARINE...JLA/KC
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1140 AM EST SUN FEB 5 2012
LATEST UPDATE...SHORT TERM...
.SYNOPSIS...(402 AM EST SUN FEB 5 2012)
MILD WEATHER WILL CONTINUE TODAY AND MONDAY WITH HIGHS MAINLY IN THE
LOW TO MID 40S EACH DAY. IT WILL ALSO REMAIN DRY TROUGH MONDAY.
CHANGES WILL BEGIN MONDAY NIGHT AS A COLD FRONT BRINGS COOLER AIR
INTO THE REGION THAT WILL LAST INTO MID WEEK. TEMPERATURES WILL BE
CLOSER TO NORMAL VALUES FOR MID WEEK...HOWEVER ANY SNOWFALL WILL BE
LIMITED. ANOTHER COLD FRONT AND AN ENFORCING SHOT OF COLD AIR
SHOULD ARRIVE THURSDAY NIGHT AND LAST INTO NEXT WEEKEND. SOME LAKE
EFFECT SNOW SHOWERS ARE EXPECTED IN THIS COLDER REGIME.
&&
.SHORT TERM...(1140 AM EST SUN FEB 5 2012)
(TODAY THROUGH TUESDAY)
MADE SMALL MODIFICATIONS TO THE GOING FORECAST...SPECIFICALLY CLOUD
COVER IN THE NORTHWEST CORNER OF THE FORECAST AREA. IT APPEARS MOST
LOCATIONS ACROSS THE AREA WILL SEE MOSTLY SUNNY SKIES...THE
EXCEPTION BEING THE NORTHWEST TOWARD LUDINGTON. MODEL LOW LEVEL RH
IS NOT DOING A GOOD JOB DEPICTING THE STRATUS. THE RUC HAS A
CLUE...BUT IT IS NOT PINPOINTING AREAS THAT ARE MOSTLY CLOUDY
EITHER. IN GENERALLY HAVE A VERY SLOW EROSION OF THE CLOUD COVER UP
THERE THROUGH SUNSET...WHICH HAS YIELDED A MOSTLY CLOUDY WORDING IN
THE FAR NORTHWEST AND BECOMING PARTLY SUNNY ELSEWHERE. NOSED HIGH
TEMPS DOWN A TAD UP THERE AS WELL GIVEN THE CLOUDS.
PREVIOUS DISCUSSION FOLLOWS...
UNEVENTFUL WEATHER CONTINUES TONIGHT AND MONDAY. ABUNDANT SUNSHINE
ON MONDAY SHOULD BOOST TEMPS INTO THE 40S AGAIN.
CLOUDS WILL BE ON THE INCREASE MONDAY EVENING AS AN ARCTIC FRONT
DROPS SOUTH ACROSS THE CWA. MOISTURE LOOKS RATHER LIMITED INITIALLY
WITH THIS FRONT...SO ONLY EXPECTING TO SEE A FEW FLURRIES AS THE
FRONT COMES IN. TEMPS BEHIND THE FRONT FOR TUESDAY SHOULD ONLY
REACH THE UPPER 20S TO MID 30S...OR NEAR NORMAL VALUES. THE MODELS
ARE TRENDING TO SHOW DEEPER MOISTURE ARRIVING ALONG THE FRONT WITH A
SHORT WAVE CROSSING THE LOWER GREAT LAKES INTO TUESDAY. THIS STILL
DOES NOT LOOK OVERLY IMPRESSIVE...BUT AS THESE FEATURES COME
TOGETHER THE SOUTHERN HALF OF THE CWA COULD SEE A DUSTING OF SNOW ON
TUESDAY. HAVE ADDED LOW CHC POPS TO THIS AREA FOR NOW.
&&
.LONG TERM...(402 AM EST SUN FEB 5 2012)
(TUESDAY NIGHT THROUGH SATURDAY)
NO BIG STORMS IN THE EXTENDED BUT SOME SNOW SHOWERS ARE POSSIBLE AS
ARCTIC AIR RETURNS THURSDAY NIGHT AND FRIDAY.
MODELS HAVE TRENDED WEAKER AND FURTHER SOUTH WITH A WAVE ALONG THE
ARCTIC FRONT ON WEDNESDAY/WEDNESDAY NIGHT AND IT APPEARS THIS
FEATURE WILL NOT HAVE MUCH EFFECT ON THE LOCAL WEATHER. SNOW SHOWERS
SHOULD INCREASE BY THURSDAY AS CLIPPER MOVES ACROSS NORTHERN LOWER
MICHIGAN WITH CYCLONIC FLOW CONTINUING INTO FRIDAY. INVERSION
HEIGHTS ARE BELOW 10 KFT THROUGH THE EVENT SO A WIDESPREAD HEAVY
LAKE EFFECT SNOW IS NOT EXPECTED.
&&
.AVIATION...(623 AM EST SUN FEB 5 2012)
MVFR CLOUDS WERE SLOWLY ADVANCING SOUTH THROUGH LOWER MI OVERNIGHT
BUT MAY REMAIN NORTH OF KGRR AND KMKG TODAY. ADDED TEMPO GROUP FOR
MKG BUT KEPT GRR VFR FOR NOW AS THE LEADING EDGE OF THE CLOUDS MAY
BEGIN TO ERODE ONCE THE SUN COMES UP. ONLY ISOLATED MVFR FOG
EXPECTED THIS MORNING AND SHOULD DISSIPATE BY 15Z.
NORTH WINDS WILL GO WEST BUT REMAIN BELOW 10 KNOTS TODAY.
&&
.MARINE...(402 AM EST SUN FEB 5 2012)
A LIGHT NW WIND IS EXPECTED OVER THE LAKE TODAY. WAVES WILL BE ON
THE LOW SIDE. BUT BY LATE TONIGHT WEST WINDS WILL BE INCREASING
AHEAD OF THE ARCTIC FRONT. WE MAY NEED A SCA LATE TONIGHT OR AT
LEAST BY EARLY MONDAY TO ACCOUNT FOR THE INCREASING WINDS AND
WAVES. THE COLD ADVECTION BEHIND THE FRONT WILL LIKELY KEEP WAVES
ON THE HIGHER SIDE INTO MONDAY NIGHT.
&&
.HYDROLOGY...(402 AM EST SUN FEB 5 2012)
LIMITED HYDRO CONCERNS THROUGH THE SHORT TERM DUE TO MINIMAL PCPN.
SNOW MELT OVER THE NORTHERN CWA WILL CONTINUE...BUT THIS WILL NOT
PUSH RIVERS OUT OF THEIR BANKS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: JK
SHORT TERM: JK/DUKE
LONG TERM: OSTUNO
AVIATION: OSTUNO
MARINE: JK
HYDROLOGY: JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
434 AM EST SUN FEB 5 2012
.SYNOPSIS...
00Z RAOBS SHOW DECAYING UPR LOW OVR KS/MO WHILE LARGER SCALE RIDGE
IS LOCATED FM WEST CONUS INTO WESTERN CANADA. PRIMARY TROUGHING IS
ORIENTED FM NORTHERN CANADA INTO QUEBEC AND NEW BRUNSWICK. COLDEST
AIR BY FAR IS LOCATED OVR FAR NORTHERN SECTIONS OF CANADA IN VCNTY
OF POLAR VORTEX. OTHERWISE...MOST OF CANADA AND THE CONUS FOR THAT
MATTER IS AWASH IN CONTINUAL FLOW OF MILD PACIFIC AIR. THIS WEEK
RIDGE IS EXPECTED TO BECOME MORE MERIDIONAL FM WESTERN CONUS INTO
ALASKA. RESULT IS EASTERN CANADA TROUGH TO SETTLE TOWARD GREAT LAKES
AND NORTHEAST CONUS. FIRST PUSH OF COOLER AIR ARRIVES ACROSS UPR
LAKES LATE MONDAY INTO TUESDAY. ANOTHER SHOT OF MUCH COLDER AIR IS
POSSIBLE LATE THIS WEEK INTO FIRST PART OF NEXT WEEKEND AS PORTION
OF POLAR VORTEX TRIES TO DISLODGE AND COME INTO THE CONUS. PATTERN
DOES NOT SUGGEST MUCH IN WAY OF OPPORTUNITY FOR LARGE SCALE WINTER
SYSTEMS. MAIN SNOWFALL THROUGH PERIOD WILL COME VIA LK EFFECT.
&&
.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...
IN THE NEAR TERM...SFC RIDGE OVR PLAINS BEGINS TO EXPAND INTO UPR
LAKES. RUC13 HAS MUCH BETTER HANDLE ON CURRENT STRATUS THAN 00Z
NAM. PER RUC13 OUTPUT AND RAOBS...MOISTURE ADVECTION IN THE CLOUD
BEARING LAYER IS NEUTRAL SO EXPECT STRATUS BASED AROUND 925MB TO
PERSIST OVR CNTRL AND EASTERN CWA. TEMPS WILL REMAIN IN THE UPR 20S
TO LOWER 30S...EXCEPT STAYING IN THE TEENS OVR FAR WEST.
TODAY AND TONIGHT...EXPECT STRATUS TO CLEAR FM WEST TO EAST THIS
MORNING AS 925MB WINDS TURN WESTERLY ALLOWING LOWER 925MB DWPNTS TO
ADVECT INTO UPR LAKES. ONCE LOW CLOUDS DEPART...MIXING HEIGHTS BUILD
BENEATH MOSTLY SUNNY SKIES /THOUGH MAY SEE SCT-BKN MID CLOUDS INTO
EARLY AFTN NCNTRL AND EAST BASED ON CURRENT TRAJECTORIES OF CLOUDS
DROPPING ACROSS ONTARIO/. MODEL PROFILES FM BUFKIT INDICATE MIXING
ONLY TO 925MB BUT GIVEN EXPECTED INSOLATION...AND SEEING THAT LOW-
LEVELS MIXED AOA 900MB ON SATURDAY PER KGRB 00Z SOUNDING...WILL OPT
FOR MORE MIXING AND HIGHER TEMPS. BLEND OF 900MB-850MB MIXING HEIGHT
SUPPORTS HIGHS WELL INTO THE 40S AND MAYBE EVEN NEAR 50 DEGREES...
ESPECIALLY IN DOWNSLOPE AREAS OF CNTRL CWA /BARAGA TO MARQUETTE AND
SOUTH TO ESCANABA AND MENOMINEE/. BASED ON HOW WARM TEMPS WERE
YDY...MAY COME CLOSE TO THE RECORD HIGH OF 50 DEGREES FOR WFO
MARQUETTE /2005/. THE WARM DAY WILL TRANSLATE TO WELL ABOVE NORMAL
TEMPS FOR TONIGHT. WARMING WILL BE MOST PRONOUNCED NEAR LK SUPERIOR
SHORE WITH WEST WINDS STIRRING ALL NIGHT AHEAD OF COLD FRONT
APPROACHING FM THE NORTH. BASED ON UPSTREAM READINGS THIS MORNING
AHEAD OF COLD FRONT...WINDS MAY STILL BECOME LIGHT IN THE INTERIOR SO
KEPT LOWS AROUND 20F INLAND WEST.
MONDAY...COLD FRONT REACHES KEWEENAW BTWN 15-18Z...THEN SWINGS
THROUGH FM NORTH TO SOUTH THROUGH THE DAY OVR REST OF CWA. RETAINED
FALLING TEMP IDEA FM PREVIOUS SHIFT...ESPECIALLY OVER THE NORTH HALF
OF THE CWA IN THE AFTN. WEST FLOW AND H9 TEMPS NEAR 0C AHEAD OF FRONT
SHOULD ALLOW TEMPS OVR FAR SCNTRL TO CLIMB INTO THE LOW 40S AT KMNM...
BEFORE FALLING OFF INTO THE LOWER 30S LATE. TEMPS WILL FALL FM THE
LOWER 30S INTO THE LOWER 20S BY SUNSET OVR REST OF THE CWA. SEEMS
THAT PCPN CHANCES WILL BE FAIRLY LIMITED UNTIL MONDAY NIGHT. FCST
SOUNDINGS FM NAM/GFS SUGGEST INCREASING STRATOCU CLOUDS MORE THAN
ANYTHING ELSE. MOIST LAYER FCST TO REACH -10C LATE AFTN INTO EARLY
EVENING SO COULD SEE SNOW GRAINS OR FLURRIES LATE IN THE DAY OVR
HIGHER TERRAIN OF NW CWA.
MONDAY NIGHT...COOLING CONTINUES AT 925-850MB WITH FCST SOUNDINGS
INDICATING MOISTURE THROUGH AROUND 5KFT BY 06Z-12Z IN A WEAKLY
CYCLONIC NORTHERLY FLOW REGIME. UNIDIRECTIONAL FLOW THROUGH
850MB/5KFT WITH WIND SPEEDS LESS THAN 20 KTS SHOULD HELP LK EFFECT
ORGANIZE LATE EVENING INTO OVERNIGHT HOURS. DESPITE SUBSIDENCE/DRYING
ABOVE INVERSION AT H85...MAJORITY OF LAKE CONVECTIVE LAYER IS WITHIN
MOST IDEAL SNOW DENDRITIC GROWTH ZONE WITH TEMPS -12C TO -18C. ECMWF
IS ON THE WARM END WHILE CANADIAN INDICATES H85 TEMPS DOWN NEAR -20C
BY LATE MONDAY NIGHT. CERTAINLY HAVE SEEN MORE IMPRESSIVE LK EFFECT
SETUP BUT DOES SEEM THAT NRLY WINDS...LOW-LEVEL CONVERGENCE...AND
FAVORABLE MOISTURE WITHIN THE DGZ JUSTIFIES INCREASING POPS OVR FAR
WEST AND ALSO OVR MUCH OF MARQUETTE AND ALGER COUNTIES. A FEW INCHES
OF SNOW IS NOT OUT OF QUESTION MONDAY NIGHT AIDED BY HIGH SLR/S AND
INCREASING FLUFFINESS TO THE SNOW. EXPECT MINS INTO THE SINGLE
DIGITS OVR THE INTERIOR WEST WITH READINGS IN THE TEENS FOR OTHER
AREAS.
.LONG TERM /12Z TUE THRU SAT/...
TUE...ALTHOUGH A SHRTWV WL BE PUSHING THRU THE UPR GRT LKS ON TUE
MRNG FOLLOWING THE SHARP COLD FROPA MON NGT...LATEST MODELS RUNS
HAVE CONTINUED TREND TOWARD RISING HGTS SHARPLY IN THE AFTN WITH
VIGOROUS DNVA/DEEP LYR QVECTOR CNVGC/SUBSIDENCE IN THE WAKE OF THE
SHRTWV PASSAGE RESULTING IN SHARP ACYC FLOW BY 00Z WED. ONGOING LES
OVER MAINLY THE N WIND SN BELTS IN THE MRNG WITH H85 TEMPS FCST BTWN
-14C BY THE ECMWF TO AS LO AS -20C BY THE CNDN MODEL WL SUPPORT
LIKELY POPS IN THE FAVORED SN BELTS WITH INVRN HGTS ARND 4K FT AGL
AT 12Z. BUT THE SHSN WL TEND TO DIMINISH STEADILY THRU THE DAY
ESPECIALLY OVER THE W AS H85 TEMPS ARE FCST TO RISE UP AS HI AS -10C
BY THE ECMWF BY 00Z WED. THE 00Z GFS INDICATES THE STRONG SUBSIDENCE
WL CAUSE THE INVRN BASE TO SINK TO 2K FT AGL BY 00Z WED...ENDING ANY
SGNFT SHSN BY LATE IN THE DAY AS PWAT SINKS BLO 0.10 INCH.
TUE NGT...UNDER RISING HGTS...SHRTWV RDG IS PROGGED TO BLD SLOWLY
THRU THE UPR GRT LKS. WITH PWAT FCST AS LO AS 0.10 INCH/MOCLR SKIES
AND LGT WINDS...EXPECT TEMPS OVER THE INTERIOR SCNTRL TO SINK AOB
THE LO END OF GUIDANCE. READINGS NEAR LK SUP WL BE BUOYED A BIT BY A
STRONGER W WIND TO THE N OF THE SFC RDG AXIS ORIENTED THRU NRN WI
INTO NRN LWR MI.
EXTENDED...HI PRES RDG WL DROP INTO THE OH VALLEY ON WED WITH A DRY
WLY FLOW DOMINATING AND TEMPS A BIT ABV NORMAL. NEXT SHRTWV WL
IMPACT THE UPR LKS ON THU. THE 00Z GFS/CNDN MODELS ARE IN FAIRLY
GOOD AGREEMENT SHOWING A STRONGER DISTURBANCE/SFC LO MOVING THRU THE
UPR LKS. WHILE THE 12Z ECMWF RUN SHOWED A SIMILAR SCENARIO...THE 00Z
RUN HAS BACKED OFF ON THE INTENSITY OF THIS DISTURBANCE...CONTINUING
A TREND OF MODEL INCONSISTENCIES ON THE HANDLING OF THIS SHRTWV. SO
WENT NO HIER THAN CHC POPS FOR SN ON THU. WITH THE ARRIVAL OF COLDER
AIR IN THE WAKE OF THE SHRTWV PASSAGE /H85 TEMPS AS LO AS -26C PER
THE 00Z GFS BUT ONLY -20C PER THE ECMWF/... EXPECT LES MAINLY IN THE
NW WIND SN BELTS INTO FRI NGT. THE ARRIVAL OF HI PRES ON SAT WL
CAUSE THE LES TO DIMINISH. EXPECT TEMPS TO RUN AOB NORMAL THU NGT
INTO SAT.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
MVFR CLOUDS AT ALL THE TAF SITES SHOULD LIFT AND DECREASE BY LATE
MORNING AS A HIGH PRESSURE RIDGE MOVES ACROSS THE AREA AND NRLY
WINDS BACK TO THE WEST. SCT-BKN MID CLOUDS THEN SLIDE THROUGH INTO
MID AFTN. CONDITIONS WILL BE VFR AFTER THE LOWER CLOUDS CLEAR THIS
MORNING.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
NORTHERLY WINDS TURN WEST AND INCREASE TO 30 KTS THIS AFTERNOON AND
EVENING AHEAD OF COLD FRONT DROPPING SOUTH ACROSS ONTARIO. MAY SEE
GALE GUSTS TO 35 KTS DUE TO COASTAL CONVERGENCE ALONG TIP OF
KEWEENAW PENINSULA. WINDS BECOME NORTHERLY ON MONDAY AFTERNOON IN
WAKE OF COLD FRONT. GALE GUSTS TO 35 KTS POSSIBLE MONDAY EVENING
OVER NORTH AND EAST...BUT THEN WINDS DIMINISH TO LESS THAN 25 KTS
LATER MONDAY NIGHT AS HIGH PRESSURE RIDGE QUICKLY BUILDS INTO UPR
LAKES REGION. A RISK OF HEAVY FREEZING SPRAY MONDAY NIGHT OVR
NORTHERN SECTIONS AS TEMPS DROP TOWARD ZERO.
THE ARRIVAL OF THE HI PRES RDG WILL CAUSE DIMINISING WINDS ON
TUE/TUE NIGHT...BUT A STRONGER WSW FLOW UP TO 25-30 KTS WILL DEVELOP
ON WED AS THIS RDG SINKS TO THE S. THE HIGHEST WINDS ARE MOST LIKELY
BETWEEN THE KEWEENAW AND ISLE ROYALE WHERE TERRAIN INFLUENCES TEND
TO ENHANCE THIS FLOW. FOLLOWING THE PASSAGE OF A LO PRES ON THU...
PLAN ON A STRONGER NNW FLOW OF COLDER AIR. THERE ARE MODEL
DIFFERENCES ON THE FORECAST INTENSITY OF THIS LO...AND GALES WOULD
NOT BE OUT OF THE QUESTION IF THE DEEPER SCENARIO VERIFIES. WITH THE
POTENTIAL ARRIVAL OF MUCH COLDER AIR...HEAVY FREEZING SPRAY MAY
IMPACT PORTIONS OF THE LAKE ON THU...ESPECIALLY THE NCENTRAL.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLA
SHORT TERM...JLA
LONG TERM...KC
AVIATION...JLA
MARINE...JLA/KC
AREA FORECAST DISCUSSION...UPDATED FOR 18Z TAFS
NWS TWIN CITIES/CHANHASSEN MN
1140 AM CST SUN FEB 5 2012
.AVIATION.../18Z TAF ISSUANCE/
WDSPRD IFR TO LIFR CONDS CURRENTLY AT ALL TAF SITES. LEADING EDGE
OF THESE CONDS HAS BEEN SNEAKING TOWARD EAU ALL MORNING AND WITHIN A
FEW MILES OF AIRPORT NOW. MAY BE A PERIOD FOR A COUPLE HOURS OF IFR
CIGS AT EAU BEFORE SUN SCATTERS CLOUDS. ACROSS WESTERN MINNESOTA
THERE HAS BEEN AN EROSION OF CLOUDS/FOG LAST HOUR OR SO. EXPECT
CLEARING WITH HELP OF SOME DOWNSLOPE WLY WINDS TO IMPROVE TO VFR AT
RWF WITHIN NEXT COUPLE OF HOURS. AXN HAS ALSO BEEN IMPROVING AND
SHUD BECOME VFR BY 21Z. VSBL SATL SHOWS CLOUDS ACROSS ABOUT N 1/2 OF
MN VERY THIN WITH LAKES SHOWING THRU CLOUDS ALL MORNING AND NICE
HOLES OPENING UP RECENTLY. THIS SHOULD WORK INTO STC MID AFTN. THE
LAST TO IMPROVE SHUD BE MSP/RNH. PIREPS SHOW CLOUDS ARND 2K THICK
AND 12Z MPX RAOB HAS NOTICEABLY DEEPER MOIST LAYER THAN
YESTERDAY...BUT SHUD IMPROVE TO MVFR ARND 20-21Z AND THEN REMAIN SO
INTO EVENING. SOME THREAT OF STRATUS REFORMING AGAIN
TONIGHT...MAINLY ACROSS WC WI INTO E MN. CDFNT PASSAGE WILL SWEEP
OUT ANY REMAINING IFR CONDS MONDAY MRNG/ERLY AFTN IMPROVING TO MVFR
CIGS.
KMSP...IFR CIGS SHOULD IMPRV TO MVFR CIGS 20-21Z...BUT FURTHER
IMPROVEMENT WILL LIKELY BE SLOW WITH CLOUDS THICKER THAN YESTERDAY.
MAY SEE A PERIOD OF VFR DURING THE EVENING WITH THREAT OF IFR
STRATUS DEVELOPING AGAIN IN THE OVERNIGHT. CDFNT PASSAGE MID DAY
MONDAY WILL BRING AN END TO THE IFR CONDS OF PAST 5 DAYS. EXPECT
MVFR CIGS IN WAKE OF CDFNT...IMPROVING TO VFR MONDAY EVENING.
&&
.DISCUSSION...
THE FORECAST CONCERN IN THE NEAR TERM REMAINS THE STRATUS OVER THE
REGION ONCE AGAIN THIS MORNING. SOUTHEAST MOVEMENT OF CLOUD DECK
SHOULD ENVELOP ALL OF MINNESOTA PORTION OF THE REGION. HRRR TRENDS
INDICATE NORTHEAST WISCONSIN CLOUDS TO WORK SOUTHWEST INTO THAT
REGION DURING THE MORNING. VSBYS NOT ALL THAT BAD THIS AM...WITH
MOST AREAS ABOVE 2SM. DOES APPEAR MORE WEST/SOUTHWEST FLOW
DEVELOPING AHEAD OF NEXT COLD FRONT SHOULD BE ENOUGH TO MIX OUT
THE STRATUS OVER THE NORTHWEST PORTION OF THE AREA THIS AFTERNOON.
WILL MENTION PARTLY CLOUDY DEVELOPING IN THE SOUTHEAST...AS
CONFIDENCE NOT HIGH ON STRATUS TOTALLY CLEARING OUT. SHOULD SEE
TEMPERATURES WARM THROUGH THE 30S INTO THE 40S WHERE CLOUDS CLEAR
FASTEST TODAY.
COLD FRONT DROPS INTO NORTHERN MINNESOTA OVERNIGHT TONIGHT. WITH
SOUTHWEST FLOW DEVELOPING SHOULD SEE TEMPERATURES STAY UP A BIT
OVERNIGHT. COULD SEE A TOUCH OF FOG OVER WESTERN WI THIS
EVENING...BUT WILL LIKELY IMPROVE AFTER MIDNIGHT IF IT DOES
DEVELOP...AS FRONT/PRESSURE GRADIENT SAGS INTO THE AREA. TEMPERATURES
SHOULD START OUT RATHER WARM MONDAY AND SHOULD SEE SOME UPPER 40S
AGAIN IN THE FAR SOUTH BEFORE FROPA IN THE AFTERNOON. CLOUDS MAY
HOLD OFF UNTIL EVENING OVER MUCH OF THE AREA...BUT DO EXPECT THEM
AROUND MUCH OF MONDAY NIGHT. MAY EVEN SEE A FLURRY OR TWO.
FLOW PATTERN APPEARS TO BE IN TRANSITION AGAIN AS WESTERN BLOCK
REMAINS. GFS AND GEM TREND AM AMPLIFICATION OF THE EASTERN CONUS
TROUGH WITH THE GFS THE MOST AMPLIFIED/COLDEST. THE 00Z ECMWF
CONTINUES ITS TREND OF DIVING SOME TROUGH ENERGY SOUTH OVER THE
EASTERN CONUS THROUGH THE WEEK BUT THE WESTERN BLOCK IS ERODED
WEST LATE IN THE WEEK WITH A MORE ZONAL TYPE FLOW PATTERN
DEVELOPING INTO THE HE WEEKEND. EXTENDED DISCUSSION DID MENTION
THEY DID NOT LIKE THE ECMWF TREND...AND THEY HELD ONTO THE EASTERN
CONUS TROUGH A BIT LONGER. THIS DOES SPELL COLDER THAN NORMAL FOR
LATE IN THE WEEK. AT THE MOMENT...PERIOD IS DRY...BUT THERE MAY BE
A FEW SNOW SHOWERS/FLURRIES...MAINLY EAST...AS COLDEST AIR
ARRIVES THURSDAY INTO FRIDAY.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
DWE/BAP
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
554 AM CST SUN FEB 5 2012
.UPDATE...
.AVIATION.../12Z TAF ISSUANCE/
IFR CIGS AFFECTING EASTERN MN WITH LIFR TO VLIFR CONDITIONS
AFFECTING WESTERN SITES. WEST CENTRAL WI HAS BEEN SKC OVERNIGHT
BUT SOME IFR CIGS TO BE MOVING INTO KRNH SHORTLY. KEAU MAY REMAIN
SKC-SCT CLOUDY BUT SOME MVFR VSBYS POSSIBLE. THE CURRENT
CONDITIONS MAY REMAIN IN PLACE UNTIL 16Z WITH SOME LIFTING OR
BREAKING BETWEEN 16Z AND 18Z. NW TO WEST WIND WITH THE HIGH
PUSHING IN SHOULD PROMOTE CLEARING SIMILAR TO YESTERDAY. AN
OVERALL DRIER ATMOSPHERE SHOULD YIELD MOSTLY CLEAR CONDITIONS
OVERNIGHT. WILL NEED TO WATCH TRENDS LATER THIS AFTERNOON FOR
MINOR FOG DEVELOPMENT LATER TONIGHT. CURRENT THINKING IS A LOW
RISK AND IT WOULD BE MVFR VSBYS. GENERAL NW WIND THIS MORNING
BECOMING WEST THIS AFTERNOON...WSW TONIGHT...ALL LESS THAN 10
KNOTS.
KMSP...CIGS JUST INTO IFR CATEGORY THIS MORNING BUT VSBYS SHOULD
BE MVFR IF THEY DO GO DOWN. EXPECT THE CIGS TO REMAIN UNTIL ABOUT
17Z WITH CLEARING DEVELOPING 18Z-19Z. GENERALLY SKC CONDITIONS
AFTER 21Z BUT WILL NEED TO WATCH FOR THE POSSIBILITY OF MVFR VSBYS
IN FOG LATE TONIGHT. NOT AS LIKELY AS THE LAST FEW NIGHTS.
.MONDAY...VFR
.MONDAY NIGHT AND TUESDAY...MVFR CIGS POSSIBLE WITH THE ARRIVAL OF
A COLD FRONT.
&&
.DISCUSSION...
THE FORECAST CONCERN IN THE NEAR TERM REMAINS THE STRATUS OVER THE
REGION ONCE AGAIN THIS MORNING. SOUTHEAST MOVEMENT OF CLOUD DECK
SHOULD ENVELOP ALL OF MINNESOTA PORTION OF THE REGION. HRRR TRENDS
INDICATE NORTHEAST WISCONSIN CLOUDS TO WORK SOUTHWEST INTO THAT
REGION DURING THE MORNING. VSBYS NOT ALL THAT BAD THIS AM...WITH
MOST AREAS ABOVE 2SM. DOES APPEAR MORE WEST/SOUTHWEST FLOW
DEVELOPING AHEAD OF NEXT COLD FRONT SHOULD BE ENOUGH TO MIX OUT
THE STRATUS OVER THE NORTHWEST PORTION OF THE AREA THIS AFTERNOON.
WILL MENTION PARTLY CLOUDY DEVELOPING IN THE SOUTHEAST...AS
CONFIDENCE NOT HIGH ON STRATUS TOTALLY CLEARING OUT. SHOULD SEE
TEMPERATURES WARM THROUGH THE 30S INTO THE 40S WHERE CLOUDS CLEAR
FASTEST TODAY.
COLD FRONT DROPS INTO NORTHERN MINNESOTA OVERNIGHT TONIGHT. WITH
SOUTHWEST FLOW DEVELOPING SHOULD SEE TEMPERATURES STAY UP A BIT
OVERNIGHT. COULD SEE A TOUCH OF FOG OVER WESTERN WI THIS
EVENING...BUT WILL LIKELY IMPROVE AFTER MIDNIGHT IF IT DOES
DEVELOP...AS FRONT/PRESSURE GRADIENT SAGS INTO THE AREA. TEMPERATURES
SHOULD START OUT RATHER WARM MONDAY AND SHOULD SEE SOME UPPER 40S
AGAIN IN THE FAR SOUTH BEFORE FROPA IN THE AFTERNOON. CLOUDS MAY
HOLD OFF UNTIL EVENING OVER MUCH OF THE AREA...BUT DO EXPECT THEM
AROUND MUCH OF MONDAY NIGHT. MAY EVEN SEE A FLURRY OR TWO.
FLOW PATTERN APPEARS TO BE IN TRANSITION AGAIN AS WESTERN BLOCK
REMAINS. GFS AND GEM TREND AM AMPLIFICATION OF THE EASTERN CONUS
TROUGH WITH THE GFS THE MOST AMPLIFIED/COLDEST. THE 00Z ECMWF
CONTINUES ITS TREND OF DIVING SOME TROUGH ENERGY SOUTH OVER THE
EASTERN CONUS THROUGH THE WEEK BUT THE WESTERN BLOCK IS ERODED
WEST LATE IN THE WEEK WITH A MORE ZONAL TYPE FLOW PATTERN
DEVELOPING INTO THE HE WEEKEND. EXTENDED DISCUSSION DID MENTION
THEY DID NOT LIKE THE ECMWF TREND...AND THEY HELD ONTO THE EASTERN
CONUS TROUGH A BIT LONGER. THIS DOES SPELL COLDER THAN NORMAL FOR
LATE IN THE WEEK. AT THE MOMENT...PERIOD IS DRY...BUT THERE MAY BE
A FEW SNOW SHOWERS/FLURRIES...MAINLY EAST...AS COLDEST AIR
ARRIVES THURSDAY INTO FRIDAY.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
DWE/JPR
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
311 AM CST SUN FEB 5 2012
.DISCUSSION...
THE FORECAST CONCERN IN THE NEAR TERM REMAINS THE STRATUS OVER THE
REGION ONCE AGAIN THIS MORNING. SOUTHEAST MOVEMENT OF CLOUD DECK
SHOULD ENVELOP ALL OF MINNESOTA PORTION OF THE REGION. HRRR TRENDS
INDICATE NORTHEAST WISCONSIN CLOUDS TO WORK SOUTHWEST INTO THAT
REGION DURING THE MORNING. VSBYS NOT ALL THAT BAD THIS AM...WITH
MOST AREAS ABOVE 2SM. DOES APPEAR MORE WEST/SOUTHWEST FLOW
DEVELOPING AHEAD OF NEXT COLD FRONT SHOULD BE ENOUGH TO MIX OUT
THE STRATUS OVER THE NORTHWEST PORTION OF THE AREA THIS AFTERNOON.
WILL MENTION PARTLY CLOUDY DEVELOPING IN THE SOUTHEAST...AS
CONFIDENCE NOT HIGH ON STRATUS TOTALLY CLEARING OUT. SHOULD SEE
TEMPERATURES WARM THROUGH THE 30S INTO THE 40S WHERE CLOUDS CLEAR
FASTEST TODAY.
COLD FRONT DROPS INTO NORTHERN MINNESOTA OVERNIGHT TONIGHT. WITH
SOUTHWEST FLOW DEVELOPING SHOULD SEE TEMPERATURES STAY UP A BIT
OVERNIGHT. COULD SEE A TOUCH OF FOG OVER WESTERN WI THIS
EVENING...BUT WILL LIKELY IMPROVE AFTER MIDNIGHT IF IT DOES
DEVELOP...AS FRONT/PRESSURE GRADIENT SAGS INTO THE AREA. TEMPERATURES
SHOULD START OUT RATHER WARM MONDAY AND SHOULD SEE SOME UPPER 40S
AGAIN IN THE FAR SOUTH BEFORE FROPA IN THE AFTERNOON. CLOUDS MAY
HOLD OFF UNTIL EVENING OVER MUCH OF THE AREA...BUT DO EXPECT THEM
AROUND MUCH OF MONDAY NIGHT. MAY EVEN SEE A FLURRY OR TWO.
FLOW PATTERN APPEARS TO BE IN TRANSITION AGAIN AS WESTERN BLOCK
REMAINS. GFS AND GEM TREND AM AMPLIFICATION OF THE EASTERN CONUS
TROUGH WITH THE GFS THE MOST AMPLIFIED/COLDEST. THE 00Z ECMWF
CONTINUES ITS TREND OF DIVING SOME TROUGH ENERGY SOUTH OVER THE
EASTERN CONUS THROUGH THE WEEK BUT THE WESTERN BLOCK IS ERODED
WEST LATE IN THE WEEK WITH A MORE ZONAL TYPE FLOW PATTERN
DEVELOPING INTO THE HE WEEKEND. EXTENDED DISCUSSION DID MENTION
THEY DID NOT LIKE THE ECMWF TREND...AND THEY HELD ONTO THE EASTERN
CONUS TROUGH A BIT LONGER. THIS DOES SPELL COLDER THAN NORMAL FOR
LATE IN THE WEEK. AT THE MOMENT...PERIOD IS DRY...BUT THERE MAY BE
A FEW SNOW SHOWERS/FLURRIES...MAINLY EAST...AS COLDEST AIR
ARRIVES THURSDAY INTO FRIDAY.
&&
.AVIATION.../06Z TAF ISSUANCE/
THE MAIN FORECAST CONCERNS AND CHALLENGES ARE THE STRATUS AND FOG
THAT WILL CONTINUE TO DEVELOP EAST OVER THE FORECAST AREA OVERNIGHT.
DURING THE EVENING...THE STRATUS HAD EXPANDED EAST AND SOUTH BACK
OVER THE TWIN CITIES...ALBERT LEA AND ONAMIA. VISIBILITIES HAVE
FARED IN THE MARGINAL VFR CATEGORY WHILE CEILING WERE IN THE
LIFR/IFR RANGE. VISIBILITIES HAD LOWERED BELOW A MILE OVER MUCH OF
WEST CENTRAL AND SOUTH CENTRAL MN. WEST TO NORTHWEST WINDS IN THE
LOWER ATMOSPHERE...WERE KEEPING THE SHALLOW MOIST LAYER FROM
BECOMING SATURATED BELOW THE INVERSION. MUCH OF THE MOISTURE WILL
PROBABLY SHAKE OUT AS FROST. EXPECT SOME AREAS OF FOG THROUGH MID
SUNDAY MORNING...THEN THE FOG/STRATUS SHOULD BEGIN TO ERODE AND LIFT
SHORTLY AFTERWARDS. WEATHER CONDITIONS BY NOON...SHOULD BE VFR
ACROSS MOST OF THE AREA. SURFACE HIGH PRESSURE RIDGE IS FORECAST TO
MOVE OVER WESTERN MN DURING THE AFTERNOON. MEANWHILE...A COLD FRONT
WILL SLIDE SOUTH INTO NORTHERN MINNESOTA BY MIDNIGHT TOMORROW
NIGHT.
MSP...IFR/LIFR FLYING CONDITIONS WILL PREVAIL THROUGH MID MORNING
SUNDAY. STRATUS LOW CLOUDS WILL CONTINUE TO PUSH EAST TO THE ST
CROIX RIVER VALLEY BY 300 AM. VISIBILITIES LOWER TO 2-3 MILES AFTER
MIDNIGHT...AND VISIBILITIES BRIEFLY LOWERING BELOW A MILE AT TIMES.
BETWEEN 900 AND 10 AM...THE FOG SHOULD HAVE BURN OFF OR ERODE. VFR
CONDITIONS PREVAILING DURING THE REST OF THE PERIOD.
.MON...VFR.
.TUE...MVFR CIGS WITH PASSAGE OF CLD FRNT.
.WED...VFR.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
DWE/JPR
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
200 PM CST SUN FEB 5 2012
.DISCUSSION...
Today we casually celebrate "National Weatherperson`s Day", which I
suppose is a bit self-gratifying. However, none of these
discussions, our forecasts, or warnings would be effective if it
were not for the media, emergency managers, observers and storm
spotters who make our jobs that much easier. So here`s to you Mr.
Gabrielson for all the help you`ve given me and the rest of the NWS
over the past few years.
Tonight: On the home front, most of the CWA has experienced abundant
sunshine in the wake of the storm system that dumped beneficial
rainfall and some snow across the region over the past two days.
Visibile satellite imagery shows the light snow cover has eroded
rapidly back toward extreme NW MO, which itself has disguised an
expansive canopy of low stratus that has blanketed eastern Nebraska
and most of Iowa today. This deck has crept southward into far nrn
MO over the past several hours, but with the loss of daytime heating
I would expect a fairly rapid expansion toward the south and east
this evening focused along the eastern half of the approaching
surface ridge axis. To further complicate matters tonight, the very
moist boundary layer, coupled with light winds and clear skies would
tend to promote a fairly healthy environment for dense freezing fog
along the periphery (or within) the stratus shield. A combination of
LIFR ceilings and fog will impact both aviation and ground travel
interests across northern and eastern Missouri overnight.
Tomorrow: A rather benign day once the fog burns off with southwest
winds returning early in the day. Should warm up to around 50 most
locations, with the exception of far NW MO where lingering light
snow cover will have some influence.
Tuesday-Wednesday: Western extension of yesterday`s storm has since
closed off over the Central Rockies and will finally begin to emerge
late Monday. This secondary gyre will gradually lose its closed
character as it opens and phases with a stronger wave dropping south
from Canada. Collectively, these systems will allow some colder air
to filter into the area Wednesday, but the accompanying
precipitation event looks anything but impressive, driven mainly by
system scale mid level ascent. Cloud cover should arrive pre-dawn
Tuesday, with a fairly broad area of light snow (northwest) to
rain (southeast) developing and persisting through early evening.
Outside of some localized enhancement, expect amounts generally
less than a tenth of an inch with little or snow snow accums.
Thursday-Saturday: Region will reside in the void between the polar
and subtropical streams with the dominant polar vortex undergoing
strong intensification over Hudson Bay with a powerful cyclonically
curved polar jet traversing its circumference. Building heights
along the west coast will keep the bulk of Pacific energy offshore
with a secondary area of troughing along the TX/MX border region.
For us, this will yield a prolonged period of dry weather with
little change in temperatures -- in fact one of the cooler periods
we`ve seen in some time.
Sunday and beyond: It appears enough shortwave impulses across the
northern Pacific will break down the western ridge yet again, while
phasing streams over the eastern states allow the longwave to shift
into the Atlantic. Thus, the trend for Sunday into early next week
should be for a return to more zonal flow with warmer conditions
moving back into the area.
Bookbinder
&&
.AVIATION...
VFR conditions continue across the terminals late this morning with
a light northwest wind. Continue to watch an extensive area of LIFR
stratus and fog that continues to drift south into far northern
Missouri. HRRR and other fine scale model output shows this deck
getting very close to STJ by 20Z, but the decreasing snow cover and
abundant sunshine to the south should put an end to the stratus
push.
Winds will diminish quickly tonight, and the very moist boundary
layer along the periphery of this stratus deck, coupled with melting
light snow cover, appears very conducive to freezing fog development
overnight. KSTJ looks like a prime target for dense fog by 09Z, and
would not be surprised to see KMCI follow suit -- initialized with
low IFR there.
Any fog should mix out by 14-15Z as winds steady from the southwest
at 6-8 knots.
Bookbinder
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1237 PM CST SUN FEB 5 2012
.DISCUSSION...
/255 AM CST SUN FEB 5 2012/
THE SHORT TERM FORECAST OVER THE NEXT 12 HOURS POSES THE BIGGEST
CHALLENGES OVER THE NEXT SEVERAL DAYS. THE FEATURE OF CONCERN IS
THE UPPER LOW FORECAST TO DROP SEWD THROUGH THE AREA TODAY AND THE
ASSOCIATED IMPACTS. PROFILER AND VWP DATA SHOW THAT THE UPPER LOW
HAS PASSED JUST SE OF KANSAS CITY. THE VAST MAJORITY OF PRECIPITATION
THUS FAR HAS ACTUALLY BEEN TO THE NORTH OF THE LOW CENTER...AND
HAS BEEN ROTATING SOUTHWESTWARD ABOUT THE CIRCULATION. NEAR AND
NORTH OF THE LOW ARE THE ONLY LOCATIONS THAT HAVE REPORTED ANY
SNOW THUS FAR AS WELL. CURRENTLY TO THE EAST OF THE LOW ACROSS
EASTERN MO...BANDS OF RAIN SHOWERS HAVE DEVELOPED WITHIN THE LAST
FEW HOURS WITHIN WHAT APPEARS TO BE A REGION OF MID LEVEL QG
FORCING. TEMPERATURES WITHIN THIS AREA RANGE FROM THE UPPER 30S TO
LOWER 40S. THE RUC APPEARS TO HAVE THE BEST HANDLE ON THE TRACK OF
THE UPPER LOW AT THIS TIME...TRACKING IT TO NEAR THE LAKE OF THE
OZARKS REGION BY 18Z. THEREAFTER THE MAJORITY OF THE MODELS WOULD
SUGGEST IT WILL CONTINUE TO TRACK SEWD AND INTO SE MO THIS
AFTERNOON AND THEN EXIT INTO THE WESTERN TN VALLEY TONIGHT. BASED
ON THIS LOW TRACK AND THE ASSOCIATED QG FORCING TO THE EAST...EXPECTING
CHANCE POPS/SCATTERED SHOWERS/DRIZZLE TO IMPACT THE AREA FROM
COU-STL-SLO SOUTHWARD. I AM NOT VERY EXCITED ABOUT THE PROSPECTS
OF ANY SNOW AND GIVEN ONLY SLIGHTLY COOLER TEMPERATURES EARLY THIS
MORNING THAN NOW...I WOULDN`T EXPECT ANY ACCUMULATION IF WE DID
SEE SOME. BY THIS AFTERNOON THE POP THREAT SHOULD BE CONFINED TO
FAR SE MO. STRATUS WILL SLOWLY CLEAR SOUTH THROUGH THE DAY AS
WELL.
WEAK HIGH PRESSURE WILL DOMINATE THE REGION TONIGHT WITH
SEASONABLY CHILLY TEMPERATURES. WESTERLY LOW LEVEL FLOW AND WARM
ADVECTION THEN GETS GOING ON MONDAY AND TEMPERATURES WILL ONCE
AGAIN BE ABOVE AVERAGE. THE NEXT SHOT OF COLD AIR LOOKS ON TRACK
FOR TUESDAY AS A NORTHERN STREAM SHORT WAVE TROF DIGS SOUTHEAST
INTO THE UPPER MIDWEST AND INTERACTS WITH THE REMNANT GREAT BASIN
UPPER LOW. WE CURRENTLY HAVE POPS JUST BELOW THRESHOLDS THAT ARE
MENTIONED IN THE FORECAST FOR THIS SYSTEM. THERE IS AND HAS BEEN
QUITE A BIT OF VARIABILITY WITH THE PRECIPITATION CHANCES...AND
CONFIDENCE IS LOW AT THIS TIME. ANYWAY THIS SHOT OF COLD AIR WILL BE A
GLANCING SHORT-LIVED BLOW BRINGING TEMPERATURES BACK DOWN TO
SEASONABLE NORMS TUESDAY NIGHT-WED NIGHT.
THE LONGER RANGE GUIDANCE...WHILE SHOWING SOME DETAIL DIFFERENCES
...IS TRENDING TOWARDS TEMPERATURES MORE WINTER-LIKE BY THE END
OF THE UPCOMING WEEK. THE GENERAL IDEA AT THIS JUNCTURE IS A DEEP
VORTEX WILL BECOME ESTABLISHED NEAR HUDSON BAY WITH A DEEP FULL
LATITUDE TROF EXTENDING TO THE SOUTH INTO THE EASTERN U.S.. THE
ORIENTATION OF THIS TROF AND INTENSITY/LONGEVITY OF THE COLD AIR
ARE WHERE THE MODELS DIFFER WITH THE GFS SHOWING POTENTIAL FOR
SOME OF THE COLDEST AIR THIS SEASON.
GLASS
&&
.AVIATION...
/1203 PM CST SUN FEB 5 2012/
UPPER LEVEL LOW WAS BETWEEN COU AND STL EARLY THIS AFTN WITH THE
CLEARING LINE MOVING S OF COU AND ABOUT TO DROP S OF THE STL METRO
AREA...ALTHOUGH THERE WAS A LITTLE DIURNAL CUMULUS OR STRATOCUMULUS
CLOUDS DEVELOPING. DESPITE THIS STL...SUS AND CPS SHOULD BE VFR
THIS AFTN WITH ONLY SCT CLOUDS LEFT BY MID-LATE AFTN. MORE OF A
CONCERN IS THE VERY LOW LEVEL STRATUS DECK ALONG WITH FOG ACROSS
IA WHICH WAS ADVECTING SWD INTO NERN MO. THIS CLOUD MASS IS NOT
HANDLED WELL BY THE MODEL GUIDANCE. ALTHOUGH THE EDGES OF THIS
CLOUD MASS MAY DISSIPATE THIS AFTN WITH DIURNAL HEATING IT APPEARS
THAT IT WILL MOVE INTO UIN BETWEEN 19-20Z SUN...AND MAY ALSO MAKE
IT DOWN TO THE REST OF THE TAF SITES THIS EVNG. FOR NOW WILL
INCLUDE A BKN-OVC CLOUD DECK IN THE UIN TAF BEGINNING AT 20Z SUN
ALONG WITH SOME FOG...THEN SCT THE CEILING OUT MON MRNG AS A WLY
WIND ADVECTS THIS CLOUD MASS E OF THE AREA. DUE TO THE UNCERTAINTY
OF THE CLOUD FORECAST AND THE POOR MODEL PERFORMANCE WILL JUST
INCLUDE SCT LOW LEVEL CLOUDS FOR THE REST OF THE TAF SITES FOR TGT
ALONG WITH LIGHT FOG. NLY SFC WINDS WILL CONTINUE THIS AFTN WITH THE
SFC RIDGE OVER THE PLAINS...THEN BECOME LIGHT THIS EVNG...AND WLY
ON MON AS THE SFC RIDGE SHIFTS SW OF OUR AREA.
SPECIFICS FOR KSTL...THE VFR CLOUDS SHOULD CLEAR OUT LATER THIS
AFTN. MUCH UNCERTAINTY IF THE STRATUS CLOUD DECK OVER IA WILL
MAKE IT DOWN AS FAR S AS STL OR MIX OUT...DISSIPATE BEFORE IT
GETS TO STL. FOR NOW WILL JUST INCLUDE SCT010 CLOUDS TGT ALONG
WITH LIGHT FOG FOR MAINLY LATE TGT AND EARLY MON MRNG. NLY SFC
WIND WILL CONTINUE THIS AFTN...THEN BECOME LIGHT THIS EVNG...AND
WLY BY LATE MON MRNG.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1132 AM CST SUN FEB 5 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Today - Tonight:
The upper low that has affected the region over the last few days
continues to weaken as it spins over northwestern Missouri. Warming
cloud top temperatures per IR satellite, decreasing radar returns and
increasing ceilings and visibilities all confirm the weakening of the
system. This trend will continue as the low slides southeast into
central Missouri and any remaining precipitation will be confined to
the vicinity of the low so have added low pops through our
southeastern zones to account for this. Any precipitation should be
out of the forecast area by mid to late morning so have kept the
afternoon period dry.
Outside of the lingering precipitation chances, today`s cloud
forecast is rather difficult. The clouds associated with the upper
low should move south and east/erode through the day. But 11-3.9u
satellite imagery reveals an area of very low stratus and fog moving
southward through Iowa and Nebraska. There may be a period of time
this morning when northern Missouri clears completely out and
coupled with recent snow across the far northwest corner of the
state could have dramatic effects on our temperatures due to
radiational cooling around sunrise. I am not overly confident on the
timing of either cloud element in our north so have tended to play
the middle ground with regards to temperatures there. Models have
very poor handling of the low stratus but see no reason why it won`t
progress southward into northern Missouri by mid morning or so,
further limiting any warm up in that part of the forecast area.
For tonight, while quiet weather is expected, models continue to
struggle with the effects of the new snow cover to our north and
northwest. The latest SREF visibility and ceiling probability
forecast indicate an increasing potential for low clouds and lower
visibilities across our north. Have therefore added a mention of fog
across northern Missouri as this makes conceptual sense given the
moist and cool boundary layer.
Monday:
Quiet weather is expected for this period as the upper level energy
that brought the region snow has been split apart, with one piece
heading east and another that has gotten cutoff within the upper
ridge over western North America. Mostly clear/clear skies are
expected and we should be able to warm back into the mid to upper 40s
for most locations and even a few 50 degree readings are possible in
our southern zones.
Monday Night - Tuesday:
The above mentioned cutoff portion should begin to eject eastward
through the Central Plains, aided by another wave diving southward
out of Canada. This will bring a chance for precipitation across the
forecast area by mid day Tuesday and with a very strong, 1040mb high
pressure surging down the Plains behind the Canadian system, enough
cold air will be move into the region bring a chance for light snow
to the forecast area. The GFS seems to the most robust with this
system with other models offering up a weaker system with less QPF.
So this system will need to be watched for the potential for light
accumulating snow. Temperatures Tuesday may not budge much from
overnight lows, especially across northern Missouri, given the cloud
cover and warm advection and highs in the lower 30s are expected
across that part of the forecast area.
Wednesday - Sunday:
Dry weather is expected to prevail through the extended period. With
a ridge developing over the western CONUS and deep troughing over
the east persisting into the later half of the week, we should see
northwesterly flow across the Central Plains. This should keep us
close to or just above normal for most the period with the possible
exception of Friday, when a colder airmass moves into the eastern
Plains/Midwest in response to the deepening eastern trough. There is
quite a bit of spread amongst the models, both deterministic and
ensembles, with how deep the trough digs but by the end of the
weekend, flow should become less amplified and a return to above
normal temperatures is expected.
CDB
&&
.AVIATION...
VFR conditions continue across the terminals late this morning with
a light northwest wind. Continue to watch an extensive area of LIFR
stratus and fog that continues to drift south into far northern
Missouri. HRRR and other fine scale model output shows this deck
getting very close to STJ by 20Z, but the decreasing snow cover and
abundant sunshine to the south should put an end to the stratus
push.
Winds will diminish quickly tonight, and the very moist boundary
layer along the periphery of this stratus deck, coupled with melting
light snow cover, appears very conducive to freezing fog development
overnight. KSTJ looks like a prime target for dense fog by 09Z, and
would not be surprised to see KMCI follow suit -- initialized with
low IFR there.
Any fog should mix out by 14-15Z as winds steady from the southwest
at 6-8 knots.
Bookbinder
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
607 AM CST SUN FEB 5 2012
.DISCUSSION...
/255 AM CST SUN FEB 5 2012/
THE SHORT TERM FORECAST OVER THE NEXT 12 HOURS POSES THE BIGGEST
CHALLENGES OVER THE NEXT SEVERAL DAYS. THE FEATURE OF CONCERN IS
THE UPPER LOW FORECAST TO DROP SEWD THROUGH THE AREA TODAY AND THE
ASSOCIATED IMPACTS. PROFILER AND VWP DATA SHOW THAT THE UPPER LOW
HAS PASSED JUST SE OF KANSAS CITY. THE VAST MAJORITY OF PRECIPITATION
THUS FAR HAS ACTUALLY BEEN TO THE NORTH OF THE LOW CENTER...AND
HAS BEEN ROTATING SOUTHWESTWARD ABOUT THE CIRCULATION. NEAR AND
NORTH OF THE LOW ARE THE ONLY LOCATIONS THAT HAVE REPORTED ANY
SNOW THUS FAR AS WELL. CURRENTLY TO THE EAST OF THE LOW ACROSS
EASTERN MO...BANDS OF RAIN SHOWERS HAVE DEVELOPED WITHIN THE LAST
FEW HOURS WITHIN WHAT APPEARS TO BE A REGION OF MID LEVEL QG
FORCING. TEMPERATURES WITHIN THIS AREA RANGE FROM THE UPPER 30S TO
LOWER 40S. THE RUC APPEARS TO HAVE THE BEST HANDLE ON THE TRACK OF
THE UPPER LOW AT THIS TIME...TRACKING IT TO NEAR THE LAKE OF THE
OZARKS REGION BY 18Z. THEREAFTER THE MAJORITY OF THE MODELS WOULD
SUGGEST IT WILL CONTINUE TO TRACK SEWD AND INTO SE MO THIS
AFTERNOON AND THEN EXIT INTO THE WESTERN TN VALLEY TONIGHT. BASED
ON THIS LOW TRACK AND THE ASSOCIATED QG FORCING TO THE EAST...EXPECTING
CHANCE POPS/SCATTERED SHOWERS/DRIZZLE TO IMPACT THE AREA FROM
COU-STL-SLO SOUTHWARD. I AM NOT VERY EXCITED ABOUT THE PROSPECTS
OF ANY SNOW AND GIVEN ONLY SLIGHTLY COOLER TEMPERATURES EARLY THIS
MORNING THAN NOW...I WOULDN`T EXPECT ANY ACCUMULATION IF WE DID
SEE SOME. BY THIS AFTERNOON THE POP THREAT SHOULD BE CONFINED TO
FAR SE MO. STRATUS WILL SLOWLY CLEAR SOUTH THROUGH THE DAY AS
WELL.
WEAK HIGH PRESSURE WILL DOMINATE THE REGION TONIGHT WITH
SEASONABLY CHILLY TEMPERATURES. WESTERLY LOW LEVEL FLOW AND WARM
ADVECTION THEN GETS GOING ON MONDAY AND TEMPERATURES WILL ONCE
AGAIN BE ABOVE AVERAGE. THE NEXT SHOT OF COLD AIR LOOKS ON TRACK
FOR TUESDAY AS A NORTHERN STREAM SHORT WAVE TROF DIGS SOUTHEAST
INTO THE UPPER MIDWEST AND INTERACTS WITH THE REMNANT GREAT BASIN
UPPER LOW. WE CURRENTLY HAVE POPS JUST BELOW THRESHOLDS THAT ARE
MENTIONED IN THE FORECAST FOR THIS SYSTEM. THERE IS AND HAS BEEN
QUITE A BIT OF VARIABILITY WITH THE PRECIPITATION CHANCES...AND
CONFIDENCE IS LOW AT THIS TIME. ANYWAY THIS SHOT OF COLD AIR WILL BE A
GLANCING SHORT-LIVED BLOW BRINGING TEMPERATURES BACK DOWN TO
SEASONABLE NORMS TUESDAY NIGHT-WED NIGHT.
THE LONGER RANGE GUIDANCE...WHILE SHOWING SOME DETAIL DIFFERENCES
...IS TRENDING TOWARDS TEMPERATURES MORE WINTER-LIKE BY THE END
OF THE UPCOMING WEEK. THE GENERAL IDEA AT THIS JUNCTURE IS A DEEP
VORTEX WILL BECOME ESTABLISHED NEAR HUDSON BAY WITH A DEEP FULL
LATITUDE TROF EXTENDING TO THE SOUTH INTO THE EASTERN U.S.. THE
ORIENTATION OF THIS TROF AND INTENSITY/LONGEVITY OF THE COLD AIR
ARE WHERE THE MODELS DIFFER WITH THE GFS SHOWING POTENTIAL FOR
SOME OF THE COLDEST AIR THIS SEASON.
GLASS
&&
.AVIATION...
/541 AM CST SUN FEB 5 2012/
IFR FLIGHT CONDITIONS IN LOW CLOUDS...DRIZZLE AND FOG WILL
CONTINUE TO PREVAIL ACROSS THE BI-STATE REGION THROUGH MUCH OF THE
MORNING HOURS ALONG AND SOUTH OF A LINE FROM KTAZ TO KMYJ. WILL SEE
CONDITIONS IMPROVE AS DRIER LOW LEVEL AIR WORKS SOUTH-SOUTHWEST
ACROSS THE AREA THROUGH MID-LATE MORNING. COULD STILL SEE SOME
LIGHT SNOW ACROSS PARTS OF CENTRAL MISSOURI EARLY THIS
MORNING...BUT THINK CHANCE IS TOO LOW TO MENTION IN KCOU TAF. LOW
CLOUDS WILL FINALLY CLEAR OUT OF SOUTHEAST MISSOURI LATE THIS
AFTERNOON OR EARLY SUNDAY EVENING. NEXT POTENTIAL IMPACT WILL BE
FOG LATE TONIGHT AND EARLY MONDAY MORNING. THINK GREATEST
POTENTIAL FOR FOG WILL BE ALONG AND SOUTH OF THE I-70 CORRIDOR
WHERE THE MOST RAIN HAS FALLEN OVER THE PAST 2 DAYS AND WHERE
CLOUDS WILL PERSIST THE LONGEST TODAY. UNSURE THOUGH AS TO AREAL
COVERAGE AND INTENSITY OF THE FOG AT THIS TIME.
SPECIFICS FOR KSTL...
IFR FLIGHT CONDITIONS WILL PERSIST FOR A GOOD PORTION OF THE
MORNING...AS WELL AS OCCASIONAL DRIZZLE AND/OR LIGHT RAIN. UNSURE
WHEN CONDITIONS WILL IMPROVE...BUT GUIDANCE SUGGESTS THE LOW
CLOUDS SHOULD MOVE SOUTH OF THE TERMINAL DURING THE MID-LATE
MORNING AS DRIER AIR WORKS ITS WAY INTO EAST CENTRAL MISSOURI.
ONCE THE LOW CLOUDS MOVE SOUTH OF LAMBERT VFR FLIGHT CONDITIONS
ARE EXPECTED AT LEAST THROUGH 06Z TONIGHT. AM EXPECTING FOG TO
DEVELOP LATE TONIGHT...BUT TIMING AND INTENSITY ARE UNCERTAIN AT
THIS TIME.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
538 AM CST Sun Feb 5 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Today - Tonight:
The upper low that has affected the region over the last few days
continues to weaken as it spins over northwestern Missouri. Warming
cloud top temperatures per IR satellite, decreasing radar returns and
increasing ceilings and visibilities all confirm the weakening of the
system. This trend will continue as the low slides southeast into
central Missouri and any remaining precipitation will be confined to
the vicinity of the low so have added low pops through our
southeastern zones to account for this. Any precipitation should be
out of the forecast area by mid to late morning so have kept the
afternoon period dry.
Outside of the lingering precipitation chances, today`s cloud
forecast is rather difficult. The clouds associated with the upper
low should move south and east/erode through the day. But 11-3.9u
satellite imagery reveals an area of very low stratus and fog moving
southward through Iowa and Nebraska. There may be a period of time
this morning when northern Missouri clears completely out and
coupled with recent snow across the far northwest corner of the
state could have dramatic effects on our temperatures due to
radiational cooling around sunrise. I am not overly confident on the
timing of either cloud element in our north so have tended to play
the middle ground with regards to temperatures there. Models have
very poor handling of the low stratus but see no reason why it won`t
progress southward into northern Missouri by mid morning or so,
further limiting any warm up in that part of the forecast area.
For tonight, while quiet weather is expected, models continue to
struggle with the effects of the new snow cover to our north and
northwest. The latest SREF visibility and ceiling probability
forecast indicate an increasing potential for low clouds and lower
visibilities across our north. Have therefore added a mention of fog
across northern Missouri as this makes conceptual sense given the
moist and cool boundary layer.
Monday:
Quiet weather is expected for this period as the upper level energy
that brought the region snow has been split apart, with one piece
heading east and another that has gotten cutoff within the upper
ridge over western North America. Mostly clear/clear skies are
expected and we should be able to warm back into the mid to upper 40s
for most locations and even a few 50 degree readings are possible in
our southern zones.
Monday Night - Tuesday:
The above mentioned cutoff portion should begin to eject eastward
through the Central Plains, aided by another wave diving southward
out of Canada. This will bring a chance for precipitation across the
forecast area by mid day Tuesday and with a very strong, 1040mb high
pressure surging down the Plains behind the Canadian system, enough
cold air will be move into the region bring a chance for light snow
to the forecast area. The GFS seems to the most robust with this
system with other models offering up a weaker system with less QPF.
So this system will need to be watched for the potential for light
accumulating snow. Temperatures Tuesday may not budge much from
overnight lows, especially across northern Missouri, given the cloud
cover and warm advection and highs in the lower 30s are expected
across that part of the forecast area.
Wednesday - Sunday:
Dry weather is expected to prevail through the extended period. With
a ridge developing over the western CONUS and deep troughing over
the east persisting into the later half of the week, we should see
northwesterly flow across the Central Plains. This should keep us
close to or just above normal for most the period with the possible
exception of Friday, when a colder airmass moves into the eastern
Plains/Midwest in response to the deepening eastern trough. There is
quite a bit of spread amongst the models, both deterministic and
ensembles, with how deep the trough digs but by the end of the
weekend, flow should become less amplified and a return to above
normal temperatures is expected.
CDB
&&
.AVIATION...
Precipitation has ended across all terminals early this morning with
only lingering BKN mid level cloud cover across the area. Clouds should
continue to break up through the next few hours and winds will remain
light through the day. Uncertainty arises thereafter as short range
guidance struggles to handle the ongoing LIFR (occasional VLIFR) cigs
and fog advecting southward across Iowa this morning. A combination
of the SREF and HRRR seem to be handling this the best at the moment
and bring the stratus/fog near the Missouri/Iowa border before
halting its southern progress. Therefore, will not bring this cloud
deck into KSTJ later this morning and will continue to indicate VFR
conditions this afternoon. However, SREF does indicate this cloud
deck/fog area to once again expand southward tonight, moving into
northern Missouri. Still much uncertainty as to whether this will
affect the terminals tonight. Will bring the edge of the stratus and
some moderate fog into KSTJ to account but will keep it north of the
Kansas City terminals for now. There is certainly some possibility of
IFR or LIFR cigs/vis overnight at STJ but confidence is not high
enough to include in the TAF at the moment.
Deroche
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
257 AM CST SUN FEB 5 2012
.DISCUSSION...
/255 AM CST SUN FEB 5 2012/
THE SHORT TERM FORECAST OVER THE NEXT 12 HOURS POSES THE BIGGEST
CHALLENGES OVER THE NEXT SEVERAL DAYS. THE FEATURE OF CONCERN IS
THE UPPER LOW FORECAST TO DROP SEWD THROUGH THE AREA TODAY AND THE
ASSOCIATED IMPACTS. PROFILER AND VWP DATA SHOW THAT THE UPPER LOW
HAS PASSED JUST SE OF KANSAS CITY. THE VAST MAJORITY OF PRECIPITATION
THUS FAR HAS ACTUALLY BEEN TO THE NORTH OF THE LOW CENTER...AND
HAS BEEN ROTATING SOUTHWESTWARD ABOUT THE CIRCULATION. NEAR AND
NORTH OF THE LOW ARE THE ONLY LOCATIONS THAT HAVE REPORTED ANY
SNOW THUS FAR AS WELL. CURRENTLY TO THE EAST OF THE LOW ACROSS
EASTERN MO...BANDS OF RAIN SHOWERS HAVE DEVELOPED WITHIN THE LAST
FEW HOURS WITHIN WHAT APPEARS TO BE A REGION OF MID LEVEL QG
FORCING. TEMPERATURES WITHIN THIS AREA RANGE FROM THE UPPER 30S TO
LOWER 40S. THE RUC APPEARS TO HAVE THE BEST HANDLE ON THE TRACK OF
THE UPPER LOW AT THIS TIME...TRACKING IT TO NEAR THE LAKE OF THE
OZARKS REGION BY 18Z. THEREAFTER THE MAJORITY OF THE MODELS WOULD
SUGGEST IT WILL CONTINUE TO TRACK SEWD AND INTO SE MO THIS
AFTERNOON AND THEN EXIT INTO THE WESTERN TN VALLEY TONIGHT. BASED
ON THIS LOW TRACK AND THE ASSOCIATED QG FORCING TO THE EAST...EXPECTING
CHANCE POPS/SCATTERED SHOWERS/DRIZZLE TO IMPACT THE AREA FROM
COU-STL-SLO SOUTHWARD. I AM NOT VERY EXCITED ABOUT THE PROSPECTS
OF ANY SNOW AND GIVEN ONLY SLIGHTLY COOLER TEMPERATURES EARLY THIS
MORNING THAN NOW...I WOULDN`T EXPECT ANY ACCUMULATION IF WE DID
SEE SOME. BY THIS AFTERNOON THE POP THREAT SHOULD BE CONFINED TO
FAR SE MO. STRATUS WILL SLOWLY CLEAR SOUTH THROUGH THE DAY AS
WELL.
WEAK HIGH PRESSURE WILL DOMINATE THE REGION TONIGHT WITH
SEASONABLY CHILLY TEMPERATURES. WESTERLY LOW LEVEL FLOW AND WARM
ADVECTION THEN GETS GOING ON MONDAY AND TEMPERATURES WILL ONCE
AGAIN BE ABOVE AVERAGE. THE NEXT SHOT OF COLD AIR LOOKS ON TRACK
FOR TUESDAY AS A NORTHERN STREAM SHORT WAVE TROF DIGS SOUTHEAST
INTO THE UPPER MIDWEST AND INTERACTS WITH THE REMNANT GREAT BASIN
UPPER LOW. WE CURRENTLY HAVE POPS JUST BELOW THRESHOLDS THAT ARE
MENTIONED IN THE FORECAST FOR THIS SYSTEM. THERE IS AND HAS BEEN
QUITE A BIT OF VARIABILITY WITH THE PRECIPITATION CHANCES...AND
CONFIDENCE IS LOW AT THIS TIME. ANYWAY THIS SHOT OF COLD AIR WILL BE A
GLANCING SHORT-LIVED BLOW BRINGING TEMPERATURES BACK DOWN TO
SEASONABLE NORMS TUESDAY NIGHT-WED NIGHT.
THE LONGER RANGE GUIDANCE...WHILE SHOWING SOME DETAIL DIFFERENCES
...IS TRENDING TOWARDS TEMPERATURES MORE WINTER-LIKE BY THE END
OF THE UPCOMING WEEK. THE GENERAL IDEA AT THIS JUNCTURE IS A DEEP
VORTEX WILL BECOME ESTABLISHED NEAR HUDSON BAY WITH A DEEP FULL
LATITUDE TROF EXTENDING TO THE SOUTH INTO THE EASTERN U.S.. THE
ORIENTATION OF THIS TROF AND INTENSITY/LONGEVITY OF THE COLD AIR
ARE WHERE THE MODELS DIFFER WITH THE GFS SHOWING POTENTIAL FOR
SOME OF THE COLDEST AIR THIS SEASON.
GLASS
&&
.AVIATION...
/1125 PM CST SAT FEB 4 2012/
MAIN FOCUS WILL BE CIGS/VSBYS. REMOVED MENTION OF SN AT COU AS ANY
PRECIP SHUD REMAIN LIQUID WITH SN REMAINING FURTHER W. BELIEVE DZ
WILL PERSIST THRU MUCH OF THE NIGHT. CONDITIONS AT UIN SHUD BEGIN
TO IMPROVE AS DRIER AIR ADVECTS INTO THE AREA. WITH DZ COMING TO
AN END AT SUS/CPS...VSBYS SHUD IMPROVE OVERNIGHT...THO PATCHES OF
DZ MAY DEVELOP AGAIN LATER TONIGHT.
SPECIFICS FOR KSTL...VSBYS SHUD IMPROVE AS DZ HAS COME TO AN
END...THO CAN NOT RULE OUT REDEVELOPMENT BEFORE SUNRISE. CIGS SHUD
IMPROVE MID TO LATE SUNDAY MORNING. WINDS EXPECTED TO REMAIN NELY
TO NLY THRU PERIOD AND DIMINISH SUNDAY AFTERNOON AS THE SFC RIDGE
BUILDS IN. CONDITIONS SHUD BE FAVORABLE FOR FG DEVELOPMENT SUN
NIGHT. HOWEVER...CONFIDENCE THIS FAR OUT IS TOO LOW TO MENTION IN
TAF ATTM.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1137 PM CST SAT FEB 4 2012
.UPDATE...
/955 PM CST SAT FEB 4 2012/
OUTSIDE OF AREAS OF DRIZZLE FROM CENTRAL INTO EAST CENTRAL
MO...PRECIP DEVELOPMENT AHEAD OF UPPER LOW HAD BEEN ALMOST NON-
EXISTANT IN OUR CWA. IN SPITE OF THIS...AM RELUCTANT TO TOTALLY
GIVE UP ON PRECIP TONIGHT. FOR THE UPDATE HAVE USED THE CURRENT
PRECIP OVER NW MO AND ITS RELATIONSHIP TO THE 7H LOW. FROM RUC AND
NAM...LOW IS FORECAST TO BE NEAR STL BY 12Z SUN...SO HAVE LAYED
OUT A NARROW BAND OF LIKELY POPS ALONG THE MO PORTION OF THE I-70
CORRIDOR FOR THE PREDAWN HOURS. AS FAR AS PTYPE IS
CONCERNED...HAVE PRETTY MUCH STAYED WITH THE TRENDS IN GOING
FORECAST. THIS MAY BE A BIT TOO FAST WITH THE RAIN TO SNOW
TRANSITION...BUT WITH THESE CLOSED UPPER SYSTEMS HAVE SEEN ENOUGH
INSTANCES WHERE FREEZING LEVELS RAPIDLY DROP THAT I DIDN`T WANT TO
GET TOO CUTE WITH THE TIMING. WOULD STILL THINK ANY ACCUMULATIONS
WOULD BE SPOTTY...AND UNDER AN INCH. UPDATE REFLECTING ABOVE
TRENDS HAS BEEN SENT.
TRUETT
&&
.SYNOPSIS...
/345 PM CST SAT FEB 4 2012/
WATER VAPOR LOOP SHOWS AN W-E ELONGATED MID LEVEL LO CENTER OVER THE
INTERFACE BETWEEN KS-NE-MO...SLOWLY OOZING E. A SPLIT FLOW PATTERN
OTHERWISE DOMINATES WRN NOAM WITH A REX BLOCK IN PLACE AND A MORE
UNIFIED FLOW OVER ERN NOAM. RADAR MOSAIC SHOWS DEFORMATION ZONE
PCPN ON THE NRN FLANK OF THE MID LEVEL FLOW AND EXTENDING EWD THRU
SRN-CNTRL IA AND NRN IL. FROM THE LO CENTER THRU CNTRL IA...THE AIR
IS COLD ENOUGH FOR THIS PCPN TO FALL AS SNOW...OTHERWISE FOR AREAS
FURTHER TO THE E...IT IS RAIN. 21Z MSAS DATA INDICATES TWO LO PRES
CENTERS...THE TRIPLE POINT OVER WRN KY AND AN OLD OCCLUDED CENTER IN
E CNTRL MO. CLOUDY SKIES ABOUND...EXCEPT IN SERN MO WHERE SUN HAS
BROKEN THRU...AND THIS HAS ALLOWED TEMPS TO WARM INTO THE MID-UPR
50S THERE. TEMPS HAVE OTHERWISE REMAINED IN THE 40S ELSEWHERE UNDER
THE THICK CLOUD CANOPY.
TES
&&
.DISCUSSION...
/345 PM CST SAT FEB 4 2012/
UPPER LOW WITH WEAK SFC LOW WILL DROP SEWD TGT AS AN UPPER LEVEL
RIDGE AND SFC RIDGE OVER THE NRN PLAINS SHIFTS SEWD. AREAS OF
DRIZZLE WILL CONTINUE THIS EVNG WHILE DEFORMATION ZONE
PRECIPITATION ACROSS SERN NEBRASKA AND SRN IA DROP SEWD THROUGH
NERN AND CNTRL MO AS WELL AS W CNTRL IL TGT. THE MODELS ARE FAIRLY
CONSISTENT WITH THE PLACEMENT OF THE PRECIPITATION FORECAST TGT AS
WELL AS THE WEAKENING TREND OR LESSENING OF THE QPF THROUGH TGT
INTO SUN MRNG. LOOKING AT MODEL PARTIAL THICKNESS FORECASTS AND
FORECAST SOUNDINGS THE P-TYPE SHOULD CHANGE FROM LIGHT RAIN TO
LIGHT SNOW IN COU AND UIN AROUND 06Z SUN OR SHORTLY AFTER...THEN
TRANSITION TO LIGHT SNOW JUST NW OF THE STL METRO AREA BY 12Z SUN
ALTHOUGH BY THIS TIME LITTLE IF ANY QPF WIL BE LEFT. WHILE MOST
AREAS N AND W OF THE STL METRO AREA WILL LIKELY ONLY RECEIVE A
LIGHT DUSTING OF SNOW... COULD NOT RULE OUT ONE HALF INCH TO NEAR
ONE INCH OF SNOW BETWEEN EDINA AND COLUMBIA MO TGT.
GKS
HOW WELL THE LO CENTER GETS PICKED UP BY A NRN STREAM SHORTWAVE
DROPPING THRU THE GREAT LAKES ON SUNDAY WILL PLAY A HUGE ROLE IN HOW
FAST THE LO CENTER MOVES THRU THE FA...WHICH WILL AFFECT HOW FAST
THE PCPN ENDS AND WHEN WE CLEAR OUT. MOST MODELS SAVE THE GFS ARE
BANKING ON THE NRN STREAM WAVE NOT PICKING UP THE OLD CNTRL CONUS LO
TOO WELL AND ARE THUS KEEPING PCPN AND CLOUDS AROUND FOR LONGER.
PCPN CURRENTLY TO OUR N IS BEING DRIVEN BY A MATURE WINTER STORM
WITH MAINLY MID LEVEL BROADSCALE FORCING AND FRONTOGENESIS...BUT
WITH SOME UPR LEVEL JET DYNAMICS TOO...TO GIVE US OUR DEFORMATION
ZONE PCPN. FRONTOGENESIS AND UPR JET DYNAMICS WILL BE THE FIRST TO
FADE LEAVING BEHIND A DILUTED STRENGTH AREA OF BROADSCALE LIFT THAT
WILL SURVIVE TO SUNDAY MORNING WHILE CONTINUING TO SLOWLY SLIDE
SEWD. WHILE MODEL SOUNDINGS SUGGEST WHAT SURVIVES WILL BE MAINLY
RAIN...EXPANDED THE AREA OF RAIN/SNOW MIX GIVEN THAT WET BULB ZERO
VALUES ARE FORECAST TO DIP JUST BELOW 1KFT AGL LEAVING LITTLE MARGIN
FOR ERROR. A FEW SPOTS MAY SEE A LIGHT DUSTING AS A RESULT...BUT
WITH SFC TEMPS ABOVE 32F IN MOST LOCATIONS...IT WILL BE DIFFICULT.
ANY PCPN THAT LINGERS MUCH PAST MID MORNING WILL BE RAIN AS TEMPS
BEGIN TO EDGE HIGHER. PREFERRED A MOS BLEND IN THE N WHERE THEY
WILL SEE SUN...BUT LEANED WITH THE COLDER MOS ELSEWHERE.
EVENING CLEARING OR CLEAR SKIES EXPECTED FOR SUNDAY NIGHT WITH HI
PRES SETTLING IN...SO AT LEAST MATCHED THE COLDEST MOS FOR MIN
TEMPS. QUIET WX THEN THRU TUESDAY MORNING WITH HI PRES IN CONTROL
AT THE SFC...BUT THIS WILL GIVE WAY TO A CDFNT LATER ON TUESDAY
WHERE INTRODUCED SOME CHCS FOR POST-FRONTAL PCPN...AS THE FRONT
ITSELF NOT STRONG ENOUGH TO KICK OFF PCPN BUT RATHER THIS WILL BE
FROM AN APPROACHING NEW CUTOFF LO FROM THE CNTRL ROCKIES. DEPENDING
ON HOW FAST THE COLD AIR RUSHES IN BEHIND THE FRONT AND HOW FAST THE
EWD TRANSLATION WILL BE WITH THAT CUTOFF LO...SOME OF THE PCPN COULD
BE SNOW IN THE FAR NRN FA...BUT MOST AREAS SHOULD SEE RAIN TUES AFTN
IF THEY GET ANYTHING AT ALL. THIS SYSTEM IS EXPECTED TO WEAKEN AS
IT MOVES E...VERY MUCH LIKE THE ONE WE ARE DEALING WITH NOW...BUT
TIMING ISSUES CONTINUE. EDGED POPS HIGHER FOR MID WEEK WITH THIS
SYSTEM BUT RELUCTANT TO DO MUCH MORE THAN THAT UNTIL WE GET BETTER
CONSENSUS ON TIMING AND TRACK. MORE POTENT ECMWF SUGGESTS POTENTIAL
FOR SOME ACCUMULATING SNOW...BUT IS AN OUTLIER AT THIS TIME.
MEDIUM RANGE HAS COME INTO BETTER AGREEMENT BETWEEN MODELS WITH A
PATTERN CHANGE IN THE AIR...AS A HI-AMPLITUDE BLOCKING RIDGE SETS UP
OVER WRN NOAM ALLOWING A DEEP TROF TO DEVELOP IN THE E. SOME
DISAGREEMENT ON HOW FAR S THIS TROF WILL PLUNGE...BUT THERE IS
AGREEMENT IN THAT IT WILL LAST THRU LATE WEEK AND INTO NEXT
WEEKEND. SOMETHING WE HAVE RARELY SEEN THIS WINTER. TEMPS
GENERALLY AVERAGE TO BELOW AVERAGE THIS PERIOD...WAITING ON MORE
AGRESSIVELY GOING LOWER...WITH FEW PCPN CHCS OUTSIDE OF THE MID WEEK
SYSTEM.
TES
&&
.AVIATION...
/1125 PM CST SAT FEB 4 2012/
MAIN FOCUS WILL BE CIGS/VSBYS. REMOVED MENTION OF SN AT COU AS ANY
PRECIP SHUD REMAIN LIQUID WITH SN REMAINING FURTHER W. BELIEVE DZ
WILL PERSIST THRU MUCH OF THE NIGHT. CONDITIONS AT UIN SHUD BEGIN
TO IMPROVE AS DRIER AIR ADVECTS INTO THE AREA. WITH DZ COMING TO
AN END AT SUS/CPS...VSBYS SHUD IMPROVE OVERNIGHT...THO PATCHES OF
DZ MAY DEVELOP AGAIN LATER TONIGHT.
SPECIFICS FOR KSTL...VSBYS SHUD IMPROVE AS DZ HAS COME TO AN
END...THO CAN NOT RULE OUT REDEVELOPMENT BEFORE SUNRISE. CIGS SHUD
IMPROVE MID TO LATE SUNDAY MORNING. WINDS EXPECTED TO REMAIN NELY
TO NLY THRU PERIOD AND DIMINISH SUNDAY AFTERNOON AS THE SFC RIDGE
BUILDS IN. CONDITIONS SHUD BE FAVORABLE FOR FG DEVELOPMENT SUN
NIGHT. HOWEVER...CONFIDENCE THIS FAR OUT IS TOO LOW TO MENTION IN
TAF ATTM.
TILLY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
316 PM CST SUN FEB 5 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
A LULL IN WEATHER ACTIVITY WILL KEEP THE AREA QUIET THROUGH
TOMORROW. SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES UPPER LOW
CUTTING OFF OVER THE GREAT BASIN FROM AN ELONGATED EAST-WEST TROUGH
AXIS...WITH AN UPPER HIGH CENTERED AROUND SOUTHERN AB/SASK/MB.
STRONG UPPER-LEVEL SHORTWAVE WAS DESCENDING OUT OF THE NW
TERRITORIES INTO NORTHERN AB/SASK. COLD AIR REMAINS LOCKED WELL
NORTH AND EAST OF THE CENTRAL US...WITH AN 850MB COLD POOL CENTERED
OVER KS/OK UNDER THE UPPER TROUGH...AND A WARM POOL OVER
SASK/MB/ND/MT UNDER THE UPPER HIGH THAT WAS DROPPING INTO THE
CENTRAL US.
MAIN FORECAST CONCERNS INCLUDE STRATUS/FOG THROUGH TONIGHT...AND
LIGHT SNOW POTENTIAL ON TUESDAY. MODELS ARE NOT HANDLING THE
SHALLOW STRATUS DECK WELL...BUT HRRR DOES HAVE A GOOD HANDLE ON THE
CURRENT EXTENT OF THE STRATUS AND FOG...AND RUC IS IN THE BALLPARK.
BOTH KEEP THE STRATUS LOCKED IN ROUGHLY ALONG AND EAST OF THE
MISSOURI RIVER THROUGH THE NIGHT...ALONG WITH DEVELOPING/KEEPING FOG
IN ROUGHLY THOSE AREAS OVERNIGHT. GIVEN AMPLE LOW-LEVEL
MOISTURE...LACK OF ANY KIND OF COLD AIR PUSH OR ADVECTION THAT WOULD
SCOUR THE MOISTURE...AND PERSISTENCE THROUGH THE DAY...AM INCLINED
TO LEAN PESSIMISTIC AND KEEP THE FOG/STRATUS OVERNIGHT. HAVE
INCLUDED A RATHER SHARP GRADIENT FROM OVERCAST TO CLEAR...WITH SOME
WESTWARD EXPANSION THROUGH THE NIGHT. NATURALLY...TEMPERATURES WILL
DEPEND STRONGLY ON LOCATION OF CLOUDS. FOR NOW...HAVE KEPT AREAS
WEST OF A LINE FROM AROUND LINCOLN TO WAYNE CLEAR...AND THUS MUCH
COLDER...THAN AREAS EAST.
DID ALLOW FOR CLOUDS TO SCOUR OUT IN THE MORNING HOURS TOMORROW AS
WEST WINDS INCREASE A BIT...THOUGH CONFIDENCE IS LOW IN THE TIMING
OF THIS. SHOULD SEE SOME MODERATION WITH WARM AIR ADVECTION AND
LIGHT MIXING DURING THE DAY...THOUGH INCREASING HIGH-LEVEL CLOUDS
LATER IN THE DAY MAY HINDER FULL SUNSHINE. COLD FRONT ASSOCIATED
WITH THE SHORTWAVE CURRENTLY LOCATED IN NORTHERN CANADA WILL DROP
THROUGH ON MONDAY NIGHT. NORTHERN STREAM WAVE AND SOUTHERN STREAM
WEAKENING/EJECTING UPPER LOW ARE PROGGED TO PHASE AS THE TWO
INTERACT OVER THE CENTRAL PLAINS...AND THE RESULTING UPPER-LEVEL
TROUGH WILL GENERATE AN AREA OF PRECIPITATION OVER KS/MO BEGINNING
LATE MONDAY NIGHT. SOUTHERN CWA LIKELY WILL BE JUST ON THE NORTHERN
FRINGE OF THAT PRECIPITATION...WITH SOME LIGHT SNOW SKIMMING THE
AREA MAINLY ON MONDAY. HAVE BACKED OFF MONDAY NIGHT PRECIP MENTION
AS SYSTEM WILL STILL BE WELL WEST AND JUST GETTING ITS ACT
TOGETHER...AND INCREASED TO HIGHER CHANCES ON TUESDAY IN THE
SOUTHERNMOST CWA WHILE TRIMMING POPS IN AREAS NORTH OF I-80 AS DRY
AIR WILL FEED INTO THE NORTHERN CWA AND SUPPRESS NORTHWARD EXPANSION
OF PRECIP.
HIGH PRESSURE WILL DROP INTO THE AREA ON TUESDAY NIGHT AS THE SYSTEM
CLEARS AWAY TO THE SOUTHEAST...AND EXPECT TEMPERATURES WILL BE ABLE
TO FALL QUITE A BIT...ESPECIALLY OVER SNOWY AREAS. HAVE SHAVED A FEW
DEGREES OFF TEMPS ON TUESDAY NIGHT...AND HAVE INCLUDED AN AREA OF
COLDER TEMPERATURES OVER THE SNOWPACK ON WEDNESDAY.
MAYES
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
STILL DRY THROUGH THE PERIOD WITH NO MAJOR WEATHER SYSTEMS OF NOTE
WITH GOOD MODEL AGREEMENT THROUGH FRIDAY. A COLD FRONT DOES MOVE
THROUGH THE REGION ON THURSDAY BRINGING SOME SLIGHTLY COOLER AIR FOR
FRIDAY. MOISTURE IS VERY MEAGER THOUGH...THUS DID NOT ADD ANY
MENTION OF PRECIP AT THIS TIME. MODEL CONTINUITY BEYOND FRIDAY
REMAINS VERY LOW. THE ECMWF BUILDS A RIDGE ACROSS THE CENTRAL US
WITH SUBSTANTIAL WARMING...WHILE THE GFS ALLOWS ANOTHER COLDER SURGE
OF AIR TO MOVE SOUTHWARD SATURDAY AND DOESN/T BEGIN A SLIGHT
WARMUP UNTIL SUNDAY. UNTIL MORE CONTINUITY DEVELOPS...WILL TREND
GRIDS SATURDAY AND SUNDAY TOWARD CLIMATOLOGY/HPC/BLENDED
SOLUTIONS.
DEWALD
&&
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
WESTERN EDGE OF STRATUS AND FOG HAS REMAINED NEARLY STATIONARY
THROUGH THE MORNING WITH LITTLE INDICATION OF MUCH EROSION
FOR THE AFTERNOON. KOFK LIES RIGHT ON THE CLOUD BOUNDARY PER
VISIBLE SATELLITE AND MAY SEE CONDITIONS THERE CHANGE FROM VFR TO
LIFR FOR A TIME THROUGH 00Z. KLNK EXPECTED TO REMAIN IN THE CLEAR
AND KOMA IN LIFR TO IFR CONDITIONS THROUGH 00Z. AFTER 00Z EXPECT
ALL THREE SITES TO DROP TO LIFR CIGS AND VSBY DURING THE EVENING
AND EXTEND INTO MONDAY MORNING.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1137 AM CST SUN FEB 5 2012
.AVIATION...18Z TAF. DRY CONDITIONS EXPECTED AT THE TERMINAL FOR
THIS TAF PERIOD...WITH MAIN CONCERN LYING WITH THE POTENTIAL FOR
FOG THIS EVENING/OVERNIGHT. LITTLE/NO CLOUD COVER EXPECTED FOR THE
REST OF THIS AFTERNOON AND INTO THE EVENING...AS THAT AREA OF
LOW LEVEL STRATUS JUST OFF TO THE EAST SHOULD REMAIN THERE. COULD
SEE SOME UPPER LEVEL CLOUDS STARTING TO MOVE IN TOWARD THE END OF
THE PERIOD WITH MODEL TIME HEIGHTS SHOWING INCREASING MOISTURE.
HIGH PRESSURE REMAINS THE PRIMARY FEATURE AT THE SURFACE...WHICH
IS EXPECTED TO BE OVERHEAD BY THIS EVENING...BEFORE STARTING TO
SLIDE TO THE SOUTH. THIS WILL KEEP WINDS IN A GENERALLY WESTERLY
DIRECTION...WITH SPEEDS NEAR/LESS THAN 10 MPH. AM CONCERNED WITH
THE LITTLE CLOUD COVER...LIGHT WINDS...AND POTENTIAL FOR INCREASED
LOW LEVEL MOISTURE FROM SNOW MELT TODAY...THAT SOME FOG WILL
DEVELOP. THOUGH NUMERICAL GUIDANCE ISNT DEPICTING VISIBILITY
ISSUES...SOME OF THE RAW MODEL OUTPUT...NAM/HRRR/RUC...DOES.
DECIDED TO INSERT A HIGH END MVFR VISIBILITY THIS
EVENING/OVERNIGHT...WITH VFR RETURNING TOMORROW MORNING.
&&
PREV DISCUSSION... /ISSUED 235 AM CST SUN FEB 5 2012/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT. 11-3.9 MICRON
SATELLITE IMAGERY EARLY THIS MORNING SHOWED A LARGE AREA OF
STRATUS DROPPING SOUTH FROM EASTERN SOUTH DAKOTA AND MINNESOTA
INTO EASTERN NEBRASKA. THE MODELS OVERALL HAVE NOT DONE A GOOD JOB
IN CAPTURING THIS AREA...THOUGH THE HRRR DOES SEEM TO HAVE AN IDEA
OF ITS PRESENCE. FOLLOWING THE HRRR WOULD SUGGEST THE WESTERN EDGE
OF THE STRATUS COULD MAKE A RUN FOR FAR EASTERN PORTIONS OF THE
FORECAST AREA. WILL INCREASE CLOUDS ACCORDINGLY...BUT IT WILL BE A
SHARPLY DEFINED LINE BETWEEN CLOUDS VS. SUN.
THE NEXT ISSUE WILL BE TEMPERATURES...AND THE MAIN MESSAGE IN THE
FORECAST THE NEXT COUPLE OF DAYS WILL BE TO CUT GUIDANCE
VALUES...ESPECIALLY IN THE HEART OF THE DEEPER SNOWPACK. AM NOT
OVERLY CONFIDENT ABOUT HOW FAR BELOW GUIDANCE TO GO...AND WILL STAY
FAIRLY CLOSE TO THE GOING FORECAST WHICH IS ABOUT 5 TO 10 DEGREES
BELOW BOTH MET AND MAV HIGH TEMPERATURE FORECASTS.
DEBATED ADDING AT LEAST SOME PATCHY FOG TO THE FORECAST TONIGHT WITH
THE 05.00Z NAM SHOWING REDUCED VISIBILITIES OVERNIGHT INTO MONDAY
MORNING. THE MAIN THING THAT KEPT US FROM JUMPING ON IT AT THIS
POINT IS THAT BOUNDARY LAYER RELATIVE HUMIDITY VALUES ARE NOT VERY
HIGH OVERNIGHT...AND PROXIMITY SOUNDINGS ONLY SHOW A VERY SHALLOW
AREA OF NEAR SATURATION. THINK WE MAY SEE SOME VERY SHALLOW GROUND
FOG...BUT WILL LET THE DAY SHIFT TAKE ANOTHER LOOK AT IT BEFORE
ADDING.
THE NEXT CHANCE FOR SNOW COULD ARRIVE MONDAY NIGHT INTO TUESDAY DUE
TO THE ARRIVAL OF THE NEXT MID LEVEL WAVE. CURRENTLY THE SYSTEM IS
SPINNING ACROSS THE INTERMOUNTAIN WEST...AND THE MODELS HAVE COME
INTO GENERAL AGREEMENT THAT IT WILL OPEN UP AND SHIFT ACROSS THE
CENTRAL AND SOUTHERN PLAINS MONDAY INTO TUESDAY. THE FINER DETAILS
REMAIN A BIT DIFFERENT...BUT THE OVERALL MESSAGE FROM THE
DETERMINISTIC MODEL RUNS ALONG WITH THE SREF IS THAT CHANCES OF SNOW
WILL INCREASE MONDAY EVENING IN WESTERN PARTS OF THE FORECAST
AREA...WITH THE CHANCES SPREADING SOUTH AND EAST OVERNIGHT MONDAY
INTO TUESDAY. DISCREPANCIES REMAIN IN THE MODEL GENERATED QPF
FIELDS...BUT BASED ON THE SPEED AND STRENGTH OF THIS SYSTEM IT
APPEARS IT COULD TRY TO GENERATE AN INCH OR SO OF SNOW...PRIMARILY
ACROSS PARTS OF NORTH CENTRAL KANSAS INTO FAR SOUTHERN NEBRASKA.
LONG TERM...WEDNESDAY THROUGH SATURDAY. CONFIDENCE IS REASONABLY
HIGH FOR DRY WEATHER THROUGH THIS 4-DAY PERIOD...ALTHOUGH
CONFIDENCE IN TEMPERATURE TRENDS IS A BIT SHAKY OWING NOT ONLY TO
MODEL DIFFERENCES...BUT ALSO TO UNCERTAINTY IN HOW MUCH IMPACT THE
FRESH SNOW PACK WILL HAVE ON HIGHS. THAT BEING SAID...IT CERTAINLY
LOOKS LIKE AT LEAST SLIGHTLY BELOW-NORMAL TEMPS WILL PERSIST
THROUGH THE PERIOD...AND CURRENT FORECAST MAY NOT BE COLD ENOUGH
AT TIMES...ESPECIALLY OVER THE DEEPER SNOW NEAR/NORTH OF HIGHWAY
6.
STARTING THINGS OUT WEDNESDAY/WEDNESDAY NIGHT...00Z GFS AND ECMWF
RUNS ARE IN REASONABLE AGREEMENT DEPICTING A GENERAL NORTHWEST
FLOW ALOFT OVER THE CENTRAL PLAINS...WITH THE PRIMARY SYNOPTIC LOW
PRESSURE SYSTEMS CONSISTING OF A HUDSON BAY VORTEX WELL TO THE
NORTHEAST...AND A SLOW-MOVING CLOSED LOW OFF BAJA WELL TO THE
SOUTHWEST. MEANWHILE...A LOWER AMPLITUDE MID LEVEL WAVE WILL BE
MOVING AWAY FROM IA EASTWARD. AT THE SURFACE...THERE IS GENERAL
AGREEMENT IN SURFACE HIGH PRESSURE SLIDING EAST DURING THE
DAY...INDUCING SOUTHERLY BREEZES...WHICH THEN TURN MORE WESTERLY
OR POSSIBLY NORTHERLY OVERNIGHT AS THE NEXT COLD FRONT MOVES
IN...BUT THE GFS SOLUTION IS DEFINITELY MUCH MORE AGGRESSIVE WITH
THIS FRONTAL INVASION THAN THE ECMWF. FOR HIGH TEMPS WED...CHANGED
VERY LITTLE FROM PREVIOUS FORECAST...REMAINING A SOLID 3-4 DEGREES
BELOW 00Z MEX GUIDANCE MAINLY TO ACCOUNT FOR SNOW PACK. THIS KEEPS
MOST NEB ZONES ONLY IN THE UPPER 20S...WITH LOW-MID 30S MORE
PREVALENT IN KS ZONES.
THURSDAY/THURSDAY NIGHT...ECMWF/GFS SOLUTIONS AGREE THAT A HIGHLY
AMPLIFIED MID-UPPER RIDGE WILL BUILD OVER THE WESTERN CONUS...BUT
EAST OF THIS FEATURE...THE GFS IS MUCH MORE AGGRESSIVE MOVING A
SHORTWAVE SOUTHWARD THROUGH THE PLAINS...ROTATING AROUND THE MAIN
HUDSON BAY REGION VORTEX. THIS IN TURN MAKES THE GFS MUCH MORE
AGGRESSIVE WITH LOW LEVEL COLD AIR ADVECTION INTO THE CWA. FOR
MOST AREAS KEPT HIGH TEMPS SIMILAR TO BOTH PREVIOUS FORECAST AND
00Z MEX GUIDANCE...WITH LOW 30S OVER DEEPER SNOW AND MID 30S
SOUTH.
FRIDAY/FRIDAY NIGHT...DIFFERENCES WITH SYNOPTIC FEATURES ALOFT
BETWEEN 00Z ECMWF/GFS SOLUTIONS CONTINUE TO MAGNIFY...WITH THE
ECMWF TRYING TO BUILD A SHORTWAVE RIDGE INTO THE CENTRAL PLAINS
MAINLY FRIDAY NIGHT...WHILE THE GFS DROPS AN AMPLIFYING SHORTWAVE
SOUTH THROUGH THE UPPER MS VALLEY/MIDWEST. THIS RESULTS IN A
DRAMATIC DIFFERENCE IN 850MB TEMPS ACROSS THE CWA...AND ALSO WIND
DIRECTION...ESPECIALLY FOR FRIDAY NIGHT WITH THE ECWMF SUGGESTING
OVERNIGHT WARM AIR ADVECTION. THE 00Z GFS ENSEMBLE MEAN 500MB
HEIGHT IS A MIDDLE GROUND BETWEEN THE DETERMINISTIC ECMWF/GFS
SOLUTIONS...AND THUS FOR HIGHS FRIDAY STUCK CLOSE TO MODEL
CONSENSUS WITH MID-UPPER 20S MOST NEB ZONES...AND MID 30S FARTHER
SOUTH. THIS UNDERCUTS 00Z MEX HIGHS BY 2-3 DEGREES MOST AREAS.
FINALLY FOR SATURDAY...CONFIDENCE REALLY GOES IN THE TANK ON THE
SYNOPTIC SCALE PATTERN...WITH THE GFS SHOWING AN EXPANSIVE
COLD SURFACE RIDGE OVER THE PLAINS...WHILE THE ECMWF HAS
IMPRESSIVE WARM ADVECTION AND SOUTHERLY BREEZES AHEAD OF A
SHORTWAVE CROSSING THE CENTRAL ROCKIES. THIS IMPLIES HIGH
TEMPERATURES COULD EASILY RANGE ANYWHERE FROM 20S TO AT LEAST 40S
ACROSS PARTS OF THE CWA...AND FOR NOW WILL PLAY CONSENSUS MIDDLE
GROUND WITH LOW 30S NORTHEAST TO LOW 40S SOUTHWEST. LOTS TO IRON
OUT AT THIS RANGE.
DESPITE THE UPCOMING STRETCH OF BELOW NORMAL TEMPERATURES...EXTENDED
MODELS SHOW NO SIGN OF A LEGITIMATE ARCTIC INVASION. ON ONE FINAL
NOTE...NOW THAT PLENTY OF SNOW IS ON THE GROUND AND LOOKS TO BE
SLOW TO FULLY MELT...THERE COULD EASILY BE POTENTIAL FOR FOG
AND/OR LOW STRATUS DURING THE NEXT WEEK...WITH THE DETAILS JUST
TOO MURKY TO RESOLVE AT THIS TIME.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...ADO
SHORT...KING
LONG...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
513 AM CST SUN FEB 5 2012
.AVIATION...12Z KGRI TAF. VFR CEILING/VISIBILITY ARE CURRENTLY
ADVERTISED THROUGHOUT THE PERIOD...WITH LIGHT WEST-NORTHWEST
BREEZES ONLY AVERAGING AROUND 7KT OR SO. THAT BEING SAID...AT
THIS HOUR...A FAIRLY EXTENSIVE IFR/LIFR STRATUS DECK ALSO
FEATURING IFR/LIFR VISIBILITY IS LURKING ROUGHLY 120 MILES
NORTH-NORTHEAST OF KGRI...AND IS SHOWING SOME SIGNS OF SAGGING
SOUTH TOWARD THE AREA OVER THE NEXT SEVERAL HOURS WITHIN THE LOW
LEVEL NORTHERLY STEERING FLOW. ALTHOUGH MOST OF THE TRADITIONAL
NUMERICAL GUIDANCE/MODELS ARE STRUGGLING TO CAPTURE THIS STRATUS
SHIELD...THE HIGH RESOLUTION RUC SEEMS TO HAVE THE BEST
HANDLE...AND AT LEAST FOR NOW...SUGGESTS THAT THE SOUTHWEST EDGE
OF THESE CLOUDS SHOULD STALL OUT WITHIN ROUGHLY 50 MILES NORTHEAST
OF KGRI. WILL PLAY THIS OPTIMISTIC SCENARIO FOR NOW...BUT AT
LEAST HINT AT LOW CLOUD POTENTIAL WITH A SCATTERED MENTION THROUGH
THE ENTIRE PERIOD. AS FOR VISIBILITY TRENDS...ASSUMING THAT
STRATUS/FOG STAYS NORTH/EAST OF THE AREA TODAY...ATTENTION TURNS
TO AT LEAST LIGHT FOG POTENTIAL OVERNIGHT WITH VERY SHALLOW MOIST
LAYER FROM MELTING SNOW...ALTHOUGH LIGHT WESTERLY WINDS SHOULD ACT
AGAINST MAJOR FOG ISSUES. FOR NOW THOUGH...WILL MAINTAIN A LIGHT
VFR VISIBILITY RESTRICTION POST-03Z...AND CONTINUE TO EMPHASIZE
THAT THIS FORECAST PERIOD CONTAINS A FEW CAVEATS THAT COULD PUT
VFR CONDITIONS IN JEOPARDY.
&&
.PREV DISCUSSION... /ISSUED 235 AM CST SUN FEB 5 2012/
SHORT TERM...TODAY THROUGH TUESDAY NIGHT. 11-3.9 MICRON
SATELLITE IMAGERY EARLY THIS MORNING SHOWED A LARGE AREA OF
STRATUS DROPPING SOUTH FROM EASTERN SOUTH DAKOTA AND MINNESOTA
INTO EASTERN NEBRASKA. THE MODELS OVERALL HAVE NOT DONE A GOOD JOB
IN CAPTURING THIS AREA...THOUGH THE HRRR DOES SEEM TO HAVE AN IDEA
OF ITS PRESENCE. FOLLOWING THE HRRR WOULD SUGGEST THE WESTERN EDGE
OF THE STRATUS COULD MAKE A RUN FOR FAR EASTERN PORTIONS OF THE
FORECAST AREA. WILL INCREASE CLOUDS ACCORDINGLY...BUT IT WILL BE A
SHARPLY DEFINED LINE BETWEEN CLOUDS VS. SUN.
THE NEXT ISSUE WILL BE TEMPERATURES...AND THE MAIN MESSAGE IN THE
FORECAST THE NEXT COUPLE OF DAYS WILL BE TO CUT GUIDANCE
VALUES...ESPECIALLY IN THE HEART OF THE DEEPER SNOWPACK. AM NOT
OVERLY CONFIDENT ABOUT HOW FAR BELOW GUIDANCE TO GO...AND WILL STAY
FAIRLY CLOSE TO THE GOING FORECAST WHICH IS ABOUT 5 TO 10 DEGREES
BELOW BOTH MET AND MAV HIGH TEMPERATURE FORECASTS.
DEBATED ADDING AT LEAST SOME PATCHY FOG TO THE FORECAST TONIGHT WITH
THE 05.00Z NAM SHOWING REDUCED VISIBILITIES OVERNIGHT INTO MONDAY
MORNING. THE MAIN THING THAT KEPT US FROM JUMPING ON IT AT THIS
POINT IS THAT BOUNDARY LAYER RELATIVE HUMIDITY VALUES ARE NOT VERY
HIGH OVERNIGHT...AND PROXIMITY SOUNDINGS ONLY SHOW A VERY SHALLOW
AREA OF NEAR SATURATION. THINK WE MAY SEE SOME VERY SHALLOW GROUND
FOG...BUT WILL LET THE DAY SHIFT TAKE ANOTHER LOOK AT IT BEFORE
ADDING.
THE NEXT CHANCE FOR SNOW COULD ARRIVE MONDAY NIGHT INTO TUESDAY DUE
TO THE ARRIVAL OF THE NEXT MID LEVEL WAVE. CURRENTLY THE SYSTEM IS
SPINNING ACROSS THE INTERMOUNTAIN WEST...AND THE MODELS HAVE COME
INTO GENERAL AGREEMENT THAT IT WILL OPEN UP AND SHIFT ACROSS THE
CENTRAL AND SOUTHERN PLAINS MONDAY INTO TUESDAY. THE FINER DETAILS
REMAIN A BIT DIFFERENT...BUT THE OVERALL MESSAGE FROM THE
DETERMINISTIC MODEL RUNS ALONG WITH THE SREF IS THAT CHANCES OF SNOW
WILL INCREASE MONDAY EVENING IN WESTERN PARTS OF THE FORECAST
AREA...WITH THE CHANCES SPREADING SOUTH AND EAST OVERNIGHT MONDAY
INTO TUESDAY. DISCREPANCIES REMAIN IN THE MODEL GENERATED QPF
FIELDS...BUT BASED ON THE SPEED AND STRENGTH OF THIS SYSTEM IT
APPEARS IT COULD TRY TO GENERATE AN INCH OR SO OF SNOW...PRIMARILY
ACROSS PARTS OF NORTH CENTRAL KANSAS INTO FAR SOUTHERN NEBRASKA.
LONG TERM...WEDNESDAY THROUGH SATURDAY. CONFIDENCE IS REASONABLY
HIGH FOR DRY WEATHER THROUGH THIS 4-DAY PERIOD...ALTHOUGH
CONFIDENCE IN TEMPERATURE TRENDS IS A BIT SHAKY OWING NOT ONLY TO
MODEL DIFFERENCES...BUT ALSO TO UNCERTAINTY IN HOW MUCH IMPACT THE
FRESH SNOW PACK WILL HAVE ON HIGHS. THAT BEING SAID...IT CERTAINLY
LOOKS LIKE AT LEAST SLIGHTLY BELOW-NORMAL TEMPS WILL PERSIST
THROUGH THE PERIOD...AND CURRENT FORECAST MAY NOT BE COLD ENOUGH
AT TIMES...ESPECIALLY OVER THE DEEPER SNOW NEAR/NORTH OF HIGHWAY
6.
STARTING THINGS OUT WEDNESDAY/WEDNESDAY NIGHT...00Z GFS AND ECMWF
RUNS ARE IN REASONABLE AGREEMENT DEPICTING A GENERAL NORTHWEST
FLOW ALOFT OVER THE CENTRAL PLAINS...WITH THE PRIMARY SYNOPTIC LOW
PRESSURE SYSTEMS CONSISTING OF A HUDSON BAY VORTEX WELL TO THE
NORTHEAST...AND A SLOW-MOVING CLOSED LOW OFF BAJA WELL TO THE
SOUTHWEST. MEANWHILE...A LOWER AMPLITUDE MID LEVEL WAVE WILL BE
MOVING AWAY FROM IA EASTWARD. AT THE SURFACE...THERE IS GENERAL
AGREEMENT IN SURFACE HIGH PRESSURE SLIDING EAST DURING THE
DAY...INDUCING SOUTHERLY BREEZES...WHICH THEN TURN MORE WESTERLY
OR POSSIBLY NORTHERLY OVERNIGHT AS THE NEXT COLD FRONT MOVES
IN...BUT THE GFS SOLUTION IS DEFINITELY MUCH MORE AGGRESSIVE WITH
THIS FRONTAL INVASION THAN THE ECMWF. FOR HIGH TEMPS WED...CHANGED
VERY LITTLE FROM PREVIOUS FORECAST...REMAINING A SOLID 3-4 DEGREES
BELOW 00Z MEX GUIDANCE MAINLY TO ACCOUNT FOR SNOW PACK. THIS KEEPS
MOST NEB ZONES ONLY IN THE UPPER 20S...WITH LOW-MID 30S MORE
PREVALENT IN KS ZONES.
THURSDAY/THURSDAY NIGHT...ECMWF/GFS SOLUTIONS AGREE THAT A HIGHLY
AMPLIFIED MID-UPPER RIDGE WILL BUILD OVER THE WESTERN CONUS...BUT
EAST OF THIS FEATURE...THE GFS IS MUCH MORE AGGRESSIVE MOVING A
SHORTWAVE SOUTHWARD THROUGH THE PLAINS...ROTATING AROUND THE MAIN
HUDSON BAY REGION VORTEX. THIS IN TURN MAKES THE GFS MUCH MORE
AGGRESSIVE WITH LOW LEVEL COLD AIR ADVECTION INTO THE CWA. FOR
MOST AREAS KEPT HIGH TEMPS SIMILAR TO BOTH PREVIOUS FORECAST AND
00Z MEX GUIDANCE...WITH LOW 30S OVER DEEPER SNOW AND MID 30S
SOUTH.
FRIDAY/FRIDAY NIGHT...DIFFERENCES WITH SYNOPTIC FEATURES ALOFT
BETWEEN 00Z ECMWF/GFS SOLUTIONS CONTINUE TO MAGNIFY...WITH THE
ECMWF TRYING TO BUILD A SHORTWAVE RIDGE INTO THE CENTRAL PLAINS
MAINLY FRIDAY NIGHT...WHILE THE GFS DROPS AN AMPLIFYING SHORTWAVE
SOUTH THROUGH THE UPPER MS VALLEY/MIDWEST. THIS RESULTS IN A
DRAMATIC DIFFERENCE IN 850MB TEMPS ACROSS THE CWA...AND ALSO WIND
DIRECTION...ESPECIALLY FOR FRIDAY NIGHT WITH THE ECWMF SUGGESTING
OVERNIGHT WARM AIR ADVECTION. THE 00Z GFS ENSEMBLE MEAN 500MB
HEIGHT IS A MIDDLE GROUND BETWEEN THE DETERMINISTIC ECMWF/GFS
SOLUTIONS...AND THUS FOR HIGHS FRIDAY STUCK CLOSE TO MODEL
CONSENSUS WITH MID-UPPER 20S MOST NEB ZONES...AND MID 30S FARTHER
SOUTH. THIS UNDERCUTS 00Z MEX HIGHS BY 2-3 DEGREES MOST AREAS.
FINALLY FOR SATURDAY...CONFIDENCE REALLY GOES IN THE TANK ON THE
SYNOPTIC SCALE PATTERN...WITH THE GFS SHOWING AN EXPANSIVE
COLD SURFACE RIDGE OVER THE PLAINS...WHILE THE ECMWF HAS
IMPRESSIVE WARM ADVECTION AND SOUTHERLY BREEZES AHEAD OF A
SHORTWAVE CROSSING THE CENTRAL ROCKIES. THIS IMPLIES HIGH
TEMPERATURES COULD EASILY RANGE ANYWHERE FROM 20S TO AT LEAST 40S
ACROSS PARTS OF THE CWA...AND FOR NOW WILL PLAY CONSENSUS MIDDLE
GROUND WITH LOW 30S NORTHEAST TO LOW 40S SOUTHWEST. LOTS TO IRON
OUT AT THIS RANGE.
DESPITE THE UPCOMING STRETCH OF BELOW NORMAL TEMPERATURES...EXTENDED
MODELS SHOW NO SIGN OF A LEGITIMATE ARCTIC INVASION. ON ONE FINAL
NOTE...NOW THAT PLENTY OF SNOW IS ON THE GROUND AND LOOKS TO BE
SLOW TO FULLY MELT...THERE COULD EASILY BE POTENTIAL FOR FOG
AND/OR LOW STRATUS DURING THE NEXT WEEK...WITH THE DETAILS JUST
TOO MURKY TO RESOLVE AT THIS TIME.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...KING
LONG TERM/AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
235 AM CST SUN FEB 5 2012
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT. 11-3.9 MICRON
SATELLITE IMAGERY EARLY THIS MORNING SHOWED A LARGE AREA OF
STRATUS DROPPING SOUTH FROM EASTERN SOUTH DAKOTA AND MINNESOTA
INTO EASTERN NEBRASKA. THE MODELS OVERALL HAVE NOT DONE A GOOD JOB
IN CAPTURING THIS AREA...THOUGH THE HRRR DOES SEEM TO HAVE AN IDEA
OF ITS PRESENCE. FOLLOWING THE HRRR WOULD SUGGEST THE WESTERN EDGE
OF THE STRATUS COULD MAKE A RUN FOR FAR EASTERN PORTIONS OF THE
FORECAST AREA. WILL INCREASE CLOUDS ACCORDINGLY...BUT IT WILL BE A
SHARPLY DEFINED LINE BETWEEN CLOUDS VS. SUN.
THE NEXT ISSUE WILL BE TEMPERATURES...AND THE MAIN MESSAGE IN THE
FORECAST THE NEXT COUPLE OF DAYS WILL BE TO CUT GUIDANCE
VALUES...ESPECIALLY IN THE HEART OF THE DEEPER SNOWPACK. AM NOT
OVERLY CONFIDENT ABOUT HOW FAR BELOW GUIDANCE TO GO...AND WILL STAY
FAIRLY CLOSE TO THE GOING FORECAST WHICH IS ABOUT 5 TO 10 DEGREES
BELOW BOTH MET AND MAV HIGH TEMPERATURE FORECASTS.
DEBATED ADDING AT LEAST SOME PATCHY FOG TO THE FORECAST TONIGHT WITH
THE 05.00Z NAM SHOWING REDUCED VISIBILITIES OVERNIGHT INTO MONDAY
MORNING. THE MAIN THING THAT KEPT US FROM JUMPING ON IT AT THIS
POINT IS THAT BOUNDARY LAYER RELATIVE HUMIDITY VALUES ARE NOT VERY
HIGH OVERNIGHT...AND PROXIMITY SOUNDINGS ONLY SHOW A VERY SHALLOW
AREA OF NEAR SATURATION. THINK WE MAY SEE SOME VERY SHALLOW GROUND
FOG...BUT WILL LET THE DAY SHIFT TAKE ANOTHER LOOK AT IT BEFORE
ADDING.
THE NEXT CHANCE FOR SNOW COULD ARRIVE MONDAY NIGHT INTO TUESDAY DUE
TO THE ARRIVAL OF THE NEXT MID LEVEL WAVE. CURRENTLY THE SYSTEM IS
SPINNING ACROSS THE INTERMOUNTAIN WEST...AND THE MODELS HAVE COME
INTO GENERAL AGREEMENT THAT IT WILL OPEN UP AND SHIFT ACROSS THE
CENTRAL AND SOUTHERN PLAINS MONDAY INTO TUESDAY. THE FINER DETAILS
REMAIN A BIT DIFFERENT...BUT THE OVERALL MESSAGE FROM THE
DETERMINISTIC MODEL RUNS ALONG WITH THE SREF IS THAT CHANCES OF SNOW
WILL INCREASE MONDAY EVENING IN WESTERN PARTS OF THE FORECAST
AREA...WITH THE CHANCES SPREADING SOUTH AND EAST OVERNIGHT MONDAY
INTO TUESDAY. DISCREPANCIES REMAIN IN THE MODEL GENERATED QPF
FIELDS...BUT BASED ON THE SPEED AND STRENGTH OF THIS SYSTEM IT
APPEARS IT COULD TRY TO GENERATE AN INCH OR SO OF SNOW...PRIMARILY
ACROSS PARTS OF NORTH CENTRAL KANSAS INTO FAR SOUTHERN NEBRASKA.
.LONG TERM...WEDNESDAY THROUGH SATURDAY. CONFIDENCE IS REASONABLY
HIGH FOR DRY WEATHER THROUGH THIS 4-DAY PERIOD...ALTHOUGH
CONFIDENCE IN TEMPERATURE TRENDS IS A BIT SHAKY OWING NOT ONLY TO
MODEL DIFFERENCES...BUT ALSO TO UNCERTAINTY IN HOW MUCH IMPACT THE
FRESH SNOW PACK WILL HAVE ON HIGHS. THAT BEING SAID...IT CERTAINLY
LOOKS LIKE AT LEAST SLIGHTLY BELOW-NORMAL TEMPS WILL PERSIST
THROUGH THE PERIOD...AND CURRENT FORECAST MAY NOT BE COLD ENOUGH
AT TIMES...ESPECIALLY OVER THE DEEPER SNOW NEAR/NORTH OF HIGHWAY
6.
STARTING THINGS OUT WEDNESDAY/WEDNESDAY NIGHT...00Z GFS AND ECMWF
RUNS ARE IN REASONABLE AGREEMENT DEPICTING A GENERAL NORTHWEST
FLOW ALOFT OVER THE CENTRAL PLAINS...WITH THE PRIMARY SYNOPTIC LOW
PRESSURE SYSTEMS CONSISTING OF A HUDSON BAY VORTEX WELL TO THE
NORTHEAST...AND A SLOW-MOVING CLOSED LOW OFF BAJA WELL TO THE
SOUTHWEST. MEANWHILE...A LOWER AMPLITUDE MID LEVEL WAVE WILL BE
MOVING AWAY FROM IA EASTWARD. AT THE SURFACE...THERE IS GENERAL
AGREEMENT IN SURFACE HIGH PRESSURE SLIDING EAST DURING THE
DAY...INDUCING SOUTHERLY BREEZES...WHICH THEN TURN MORE WESTERLY
OR POSSIBLY NORTHERLY OVERNIGHT AS THE NEXT COLD FRONT MOVES
IN...BUT THE GFS SOLUTION IS DEFINITELY MUCH MORE AGGRESSIVE WITH
THIS FRONTAL INVASION THAN THE ECMWF. FOR HIGH TEMPS WED...CHANGED
VERY LITTLE FROM PREVIOUS FORECAST...REMAINING A SOLID 3-4 DEGREES
BELOW 00Z MEX GUIDANCE MAINLY TO ACCOUNT FOR SNOW PACK. THIS KEEPS
MOST NEB ZONES ONLY IN THE UPPER 20S...WITH LOW-MID 30S MORE
PREVALENT IN KS ZONES.
THURSDAY/THURSDAY NIGHT...ECMWF/GFS SOLUTIONS AGREE THAT A HIGHLY
AMPLIFIED MID-UPPER RIDGE WILL BUILD OVER THE WESTERN CONUS...BUT
EAST OF THIS FEATURE...THE GFS IS MUCH MORE AGGRESSIVE MOVING A
SHORTWAVE SOUTHWARD THROUGH THE PLAINS...ROTATING AROUND THE MAIN
HUDSON BAY REGION VORTEX. THIS IN TURN MAKES THE GFS MUCH MORE
AGGRESSIVE WITH LOW LEVEL COLD AIR ADVECTION INTO THE CWA. FOR
MOST AREAS KEPT HIGH TEMPS SIMILAR TO BOTH PREVIOUS FORECAST AND
00Z MEX GUIDANCE...WITH LOW 30S OVER DEEPER SNOW AND MID 30S
SOUTH.
FRIDAY/FRIDAY NIGHT...DIFFERENCES WITH SYNOPTIC FEATURES ALOFT
BETWEEN 00Z ECMWF/GFS SOLUTIONS CONTINUE TO MAGNIFY...WITH THE
ECMWF TRYING TO BUILD A SHORTWAVE RIDGE INTO THE CENTRAL PLAINS
MAINLY FRIDAY NIGHT...WHILE THE GFS DROPS AN AMPLIFYING SHORTWAVE
SOUTH THROUGH THE UPPER MS VALLEY/MIDWEST. THIS RESULTS IN A
DRAMATIC DIFFERENCE IN 850MB TEMPS ACROSS THE CWA...AND ALSO WIND
DIRECTION...ESPECIALLY FOR FRIDAY NIGHT WITH THE ECWMF SUGGESTING
OVERNIGHT WARM AIR ADVECTION. THE 00Z GFS ENSEMBLE MEAN 500MB
HEIGHT IS A MIDDLE GROUND BETWEEN THE DETERMINISTIC ECMWF/GFS
SOLUTIONS...AND THUS FOR HIGHS FRIDAY STUCK CLOSE TO MODEL
CONSENSUS WITH MID-UPPER 20S MOST NEB ZONES...AND MID 30S FARTHER
SOUTH. THIS UNDERCUTS 00Z MEX HIGHS BY 2-3 DEGREES MOST AREAS.
FINALLY FOR SATURDAY...CONFIDENCE REALLY GOES IN THE TANK ON THE
SYNOPTIC SCALE PATTERN...WITH THE GFS SHOWING AN EXPANSIVE
COLD SURFACE RIDGE OVER THE PLAINS...WHILE THE ECMWF HAS
IMPRESSIVE WARM ADVECTION AND SOUTHERLY BREEZES AHEAD OF A
SHORTWAVE CROSSING THE CENTRAL ROCKIES. THIS IMPLIES HIGH
TEMPERATURES COULD EASILY RANGE ANYWHERE FROM 20S TO AT LEAST 40S
ACROSS PARTS OF THE CWA...AND FOR NOW WILL PLAY CONSENSUS MIDDLE
GROUND WITH LOW 30S NORTHEAST TO LOW 40S SOUTHWEST. LOTS TO IRON
OUT AT THIS RANGE.
DESPITE THE UPCOMING STRETCH OF BELOW NORMAL TEMPERATURES...EXTENDED
MODELS SHOW NO SIGN OF A LEGITIMATE ARCTIC INVASION. ON ONE FINAL
NOTE...NOW THAT PLENTY OF SNOW IS ON THE GROUND AND LOOKS TO BE
SLOW TO FULLY MELT...THERE COULD EASILY BE POTENTIAL FOR FOG
AND/OR LOW STRATUS DURING THE NEXT WEEK...WITH THE DETAILS JUST
TOO MURKY TO RESOLVE AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 1124 PM CST SAT FEB 4 2012/
AVIATION...06Z KGRI TAF. VFR CEILING/VISIBILITY ARE CURRENTLY
ADVERTISED THROUGHOUT THE PERIOD...WITH LIGHT WEST-NORTHWEST
BREEZES ONLY AVERAGING AROUND 7KT OR SO. THAT BEING SAID...NOW
THAT EXTENSIVE SNOW COVER IS ON THE GROUND...THE NEXT SEVERAL DAYS
AND ESPECIALLY NIGHTS WILL HAVE TO BE CLOSELY MONITORED FOR THE
POTENTIAL FOR FOG AND/OR LOW STRATUS TO MATERIALIZE. AT THIS
TIME...ONE OF THESE FAIRLY EXTENSIVE IFR/LIFR STRATUS DECKS IS
LURKING ROUGHLY 140 MILES NORTH-NORTHEAST OF THE TERMINAL...AND IS
SHOWING SOME SIGNS OF SAGGING SOUTH TOWARD THE AREA OVER THE NEXT
12-18 HOURS WITH THE LOW LEVEL STEERING FLOW. AT THIS
TIME...TRADITIONAL NUMERICAL GUIDANCE AND MOST SHORT TERM MODEL
DATA KEEP THESE LOW CLOUDS AT LEAST SLIGHTLY EAST OF KGRI...BUT
THIS WILL NEED CLOSELY MONITORED. EVEN IF LOW STRATUS STAYS
AWAY...THE BEGINNING STAGES OF SNOW MELT AND CONTINUED LIGHT WINDS
COULD PROMOTE AT LEAST PATCHY FOG DEVELOPMENT MAINLY FOR SUNDAY
EVENING/OVERNIGHT. ALL THESE CAVEATS BEING SAID...GIVEN LACK OF
SUPPORT FROM CURRENT MODEL GUIDANCE...WILL MAINTAIN VFR CONDITIONS
FOR NOW BUT AT LEAST HINT AT POSSIBLE ISSUES BY INSERTING A
SCATTERED LOW STRATUS GROUP FOR MUCH OF THE PERIOD...AND A LIGHT
VFR VISIBILITY RESTRICTION SUNDAY EVENING. BOTTOM LINE...THIS
FORECAST MAY NOT BE QUITE AS STRAIGHTFORWARD AS CURRENT GUIDANCE
WOULD SUGGEST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...KING
LONG TERM/AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1251 PM EST SUN FEB 5 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL PASS THROUGH TODAY...WITH CLOUDS
AND A FEW FLURRIES MAINLY ACROSS CENTRAL NEW YORK. OTHERWISE...DRY
WEATHER WILL CONTINUE INTO THE FIRST PART OF THE WORK WEEK AS HIGH
PRESSURE BUILDS INTO THE REGION FROM THE MIDWEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE...AS HAS BEEN THE CASE THE LAST FEW DAYS...STRUGGLE
OF THE DAY AGAIN IS STRATOCUMULUS THAT THE MODELS ARE FAILING TO
CAPTURE. MOST UPDATED RUC MODEL...ESPECIALLY RH AROUND
850MB...SEEMS TO HAVE THE BEST HANDLE OF CURRENT SITUATION. SKY
GRIDS WERE INCREASED SIGNIFICANTLY ESPECIALLY FOR THE NEW YORK
ZONES FOR TODAY...AND AS A RESULT...TEMPERATURES WERE ADJUSTED
LOWER. ALSO...COMBINATION OF VORTICITY LOBE SWINGING THROUGH
ALOFT...AND MESOVORTEX THAT DEVELOPED OVER WESTERN LAKE
ONTARIO...WILL ENHANCE THINGS ENOUGH TO PRODUCE A FEW NON-
ACCUMULATING FLURRIES FOR MUCH OF CENTRAL NEW YORK. LATE IN THE
DAY...DIURNAL TIMING...WARM AIR ADVECTION ALOFT...AND BACKING OF
LOW LEVEL FLOW WILL HELP TO BREAK UP THE CLOUDS COVER HEADING INTO
TONIGHT...THOUGH CLOUDS AND A FEW FLURRIES WILL STILL BE POSSIBLE
NORTH OF THE THRUWAY THIS EVENING.
ANOTHER RIPPLE IN THE FLOW COULD SKIM THE AREA WITH BRIEF AXIS OF
MID/HIGH LEVEL CLOUDS OVERNIGHT...BUT OVERALL LOOKING AT LITTLE
CLOUD COVER DURING THE PREDAWN HOURS MONDAY MORNING.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
MORE QUIET WX IN THE SHRT TERM AS NRN STREAM ENERGY STAYS
NORTH...AND DEEP SRN STREAM MOISTURE REMAINS SOUTH. LRG SFC HIPRES
OVER THE MIDDLE OF THE COUNTRY NOSES EAST TO THE MID ATLANTIC
KEEPING THE AREA DRY YET IN A MILD WLY FLOW. ONLY SYSTEM OF NOTE
IN THE PD IS A SHALLOW COLD FNT DROPPING IN FROM THE NORTH TUE.
FNT WILL BRING CLDS AND PERHAPS A FEW FLURRIES...ESP OVER THE
FINGER LAKES AS THE FLOW WITH THE CAA IS MORE NLY THAN NW.
HWVR...AIR IS JUST NOT ALL THAT COLD SO LE WILL BE VERY LIMITED
AND PRBLY CONFINED TO THE AREA OF THE FNT WITH THE ENHANCED LIFT.
TEMPS WILL CONT WELL ABV NRML IN THE PD. MODEL GUID WAS IN GOOD
GNRL AGREEMENT FOR THE PD SO OVERALL CONFIDENCE IN THE FCST IS
HIGH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
UPDATED AS OF 330 PM SAT... OVERALL...NOT A GREAT DEAL OF CHG TO THE
LARGE-SCALE PATTERN SEEN WITH THE MODELS AGAIN TODAY.
EC/GFS/ENSEMBLE CONSENSUS SUGGESTS THAT A VORTEX WILL REMAIN IN
PLACE NEAR HUDSON`S BAY...WITH UPPER-LVL RIDGING OVER WRN CANADA.
ALTHOUGH THIS WILL KEEP FAST MOVG NRN STREAM DISTURBANCES COMING
ACRS NY/PA ABT EVERY 24-36 HRS...IT WILL ALSO KEEP THE GOMEX CUT
OFF. THIS FACTOR...IN COMBINATION WITH A CONTINUED LACK OF SIG HI-
LAT BLOCKING OVER GREENLAND/NWRN ATLANTIC...SHOULD KEEP ANY MAJOR
STORMS/HVY PCPN EVENTS FROM IMPACTING OUR FA THIS PD. ALSO...GIVEN
THE LACK OF SNOW COVER...AND THE LIKELIHOOD THAT THE CORE OF THE
ARCTIC AIR WILL REMAIN N OF THE CANADA/U.S. BORDER...TEMPS SHOULD
CONTINUE TO AVERAGE NEAR TO SOMEWHAT ABV SEASONAL NORMS FOR EARLY FEB.
DAILY WX-WISE...A FAST MOVG UPPER-LVL TROUGH/SFC WAVE ARE EXPECTED
TO UNDERCUT THE ABV MENTIONED ERN CANADIAN VORTEX AND TRACK
THROUGH THE MID-ATL RGN WED...OR PERHAPS EARLY THU. THIS SYSTEM
COULD BRING A SHOT OF LGT SNOW...ALTHOUGH THE NRN EXTENT OF THE
PCPN IS UNCERTAIN ATTM. BOTTOM LN THOUGH...THIS SYSTEM SHOULDN`T
HAVE TIME TO PICK UP MUCH MOIST...SO AGN ANY SNOW LOOKS LIGHT.
OTHERWISE (FROM LATER THU INTO NEXT WEEKEND)...QUICK MOVG IMPULSES
IN THE NRN STREAM WILL REINFORCE POLAR ORIGIN AIR MASSES (HIGHS
MAINLY IN THE 30S...WITH NIGHTTIME LOWS IN THE TEENS AND 20S).
OVERALL...THESE AIR MASSES LOOK INSUFFICIENTLY COLD/MOIST TO
GENERATE MUCH OF A LAKE RESPONSE...SO JUST OCNL FLRYS/-SHSN WILL
BE CALLED FOR IN THE FCST.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A WEAK TROUGH IS MAKING ITS WAY THROUGH THE FORECAST AREA THIS
AFTERNOON AND WILL CONTINUE TO DO SO THROUGH THE EARLY EVENING
HOURS. THIS WILL KEEP A NORTH TO NORTHWESTERLY FLOW ALOFT AND
CLOUDS IN THE AREA. THE CLOUD DECK IS EXPECTED TO REMAIN ABOVE VFR
FOR THE TAF PERIOD AND SHOULD EVEN BEGIN TO DIMINISH IN THE LATE
EVENING TO EARLY MORNING HOURS.
WINDS RANGE TODAY FROM LIGHT AND VARIABLE UP TO NORTH NORTHWEST
AROUND 10KTS SOUTH OF BGM. MOST LOCATIONS WILL REMAIN LIGHT AND
VARIABLE TONIGHT WITH OTHER LOCATIONS TURNING TO SOUTHWEST AROUND
5 KTS. MONDAY MORNING WILL SEE WINDS OUT OF THE WEST SOUTHWEST
AROUND 10KTS.
.OUTLOOK...
MON NGT-TUE NGT...VFR WITH PSBL MVFR IN LAKE-EFFECT SHSN.
WED...MAINLY VFR...BUT MVFR POSSIBLE TOWARD EVENING IN LGT SNOW.
THU AND FRIDAY...VFR/MVFR PSBL IN LGT SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...DGM/MDP
SHORT TERM...DGM
LONG TERM...MLJ
AVIATION...SLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1022 AM EST SUN FEB 5 2012
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL PASS THROUGH TODAY...WITH CLOUDS
AND A FEW FLURRIES MAINLY ACROSS CENTRAL NEW YORK. OTHERWISE...DRY
WEATHER WILL CONTINUE INTO THE FIRST PART OF THE WORK WEEK AS HIGH
PRESSURE BUILDS INTO THE REGION FROM THE MIDWEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
1015 AM UPDATE...AS HAS BEEN THE CASE THE LAST FEW DAYS...STRUGGLE
OF THE DAY AGAIN IS STRATOCUMULUS THAT THE MODELS ARE FAILING TO
CAPTURE. MOST UPDATED RUC MODEL...ESPECIALLY RH AROUND
850MB...SEEMS TO HAVE THE BEST HANDLE OF CURRENT SITUATION. SKY
GRIDS WERE INCREASED SIGNIFICANTLY ESPECIALLY FOR THE NEW YORK
ZONES FOR TODAY...AND AS A RESULT...TEMPERATURES WERE ADJUSTED
LOWER. ALSO...COMBINATION OF VORTICITY LOBE SWINGING THROUGH
ALOFT...AND MESOVORTEX THAT DEVELOPED OVER WESTERN LAKE
ONTARIO...WILL ENHANCE THINGS ENOUGH TO PRODUCE A FEW NON-
ACCUMULATING FLURRIES FOR MUCH OF CENTRAL NEW YORK. LATE IN THE
DAY...DIURNAL TIMING...WARM AIR ADVECTION ALOFT...AND BACKING OF
LOW LEVEL FLOW WILL HELP TO BREAK UP THE CLOUDS COVER HEADING INTO
TONIGHT...THOUGH CLOUDS AND A FEW FLURRIES WILL STILL BE POSSIBLE
NORTH OF THE THRUWAY THIS EVENING.
ANOTHER RIPPLE IN THE FLOW COULD SKIM THE AREA WITH BRIEF AXIS OF
MID/HIGH LEVEL CLOUDS OVERNIGHT...BUT OVERALL LOOKING AT LITTLE
CLOUD COVER DURING THE PREDAWN HOURS MONDAY MORNING.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
MORE QUIET WX IN THE SHRT TERM AS NRN STREAM ENERGY STAYS
NORTH...AND DEEP SRN STREAM MOISTURE REMAINS SOUTH. LRG SFC HIPRES
OVER THE MIDDLE OF THE COUNTRY NOSES EAST TO THE MID ATLANTIC
KEEPING THE AREA DRY YET IN A MILD WLY FLOW. ONLY SYSTEM OF NOTE
IN THE PD IS A SHALLOW COLD FNT DROPPING IN FROM THE NORTH TUE.
FNT WILL BRING CLDS AND PERHAPS A FEW FLURRIES...ESP OVER THE
FINGER LAKES AS THE FLOW WITH THE CAA IS MORE NLY THAN NW.
HWVR...AIR IS JUST NOT ALL THAT COLD SO LE WILL BE VERY LIMITED
AND PRBLY COMFINED TO THE AREA OF THE FNT WITH THE ENHANCED LIFT.
TEMPS WILL CONT WELL ABV NRML IN THE PD. MODEL GUID WAS IN GOOD
GNRL AGREEMENT FOR THE PD SO OVERALL CONFIDENCE IN THE FCST IS
HIGH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
UPDATED AS OF 330 PM SAT... OVERALL...NOT A GREAT DEAL OF CHG TO THE
LARGE-SCALE PATTERN SEEN WITH THE MODELS AGAIN TODAY.
EC/GFS/ENSEMBLE CONSENSUS SUGGESTS THAT A VORTEX WILL REMAIN IN
PLACE NEAR HUDSON`S BAY...WITH UPPER-LVL RIDGING OVER WRN CANADA.
ALTHOUGH THIS WILL KEEP FAST MOVG NRN STREAM DISTURBANCES COMING
ACRS NY/PA ABT EVERY 24-36 HRS...IT WILL ALSO KEEP THE GOMEX CUT
OFF. THIS FACTOR...IN COMBINATION WITH A CONTINUED LACK OF SIG HI-
LAT BLOCKING OVER GREENLAND/NWRN ATLANTIC...SHOULD KEEP ANY MAJOR
STORMS/HVY PCPN EVENTS FROM IMPACTING OUR FA THIS PD. ALSO...GIVEN
THE LACK OF SNOW COVER...AND THE LIKELIHOOD THAT THE CORE OF THE
ARCTIC AIR WILL REMAIN N OF THE CANADA/U.S. BORDER...TEMPS SHOULD
CONTINUE TO AVERAGE NEAR TO SOMEWHAT ABV SEASONAL NORMS FOR EARLY FEB.
DAILY WX-WISE...A FAST MOVG UPPER-LVL TROUGH/SFC WAVE ARE EXPECTED
TO UNDERCUT THE ABV MENTIONED ERN CANADIAN VORTEX AND TRACK
THROUGH THE MID-ATL RGN WED...OR PERHAPS EARLY THU. THIS SYSTEM
COULD BRING A SHOT OF LGT SNOW...ALTHOUGH THE NRN EXTENT OF THE
PCPN IS UNCERTAIN ATTM. BOTTOM LN THOUGH...THIS SYSTEM SHOULDN`T
HAVE TIME TO PICK UP MUCH MOIST...SO AGN ANY SNOW LOOKS LIGHT.
OTHERWISE (FROM LATER THU INTO NEXT WEEKEND)...QUICK MOVG IMPULSES
IN THE NRN STREAM WILL REINFORCE POLAR ORIGIN AIR MASSES (HIGHS
MAINLY IN THE 30S...WITH NIGHTTIME LOWS IN THE TEENS AND 20S).
OVERALL...THESE AIR MASSES LOOK INSUFFICIENTLY COLD/MOIST TO
GENERATE MUCH OF A LAKE RESPONSE...SO JUST OCNL FLRYS/-SHSN WILL
BE CALLED FOR IN THE FCST.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
UPDATED AS OF 630 AM SUN... VFR CONDITIONS EXPECTED TODAY WITH BKN-
OVC CLOUDS WITH HTS OF GENERALLY 3 TO 5 KFT. SKIES WILL BECOME
MAINLY CLEAR TONIGHT... EXCEPT FOR SOME PATCHY CLOUDS POSSIBLY
LINGERING AT RME AND SYR. CLOUD HTS WILL BE VFR ABV 3000 FEET.
WINDS WILL BE LIGHT AND VARIABLE BECOMING NW AT 5 TO 10 KTS
TODAY... AND WSW AT LESS THAN 10 KTS TONIGHT.
.OUTLOOK...
MON NGT-TUE NGT...PSBL MVFR/IFR IN LAKE-EFFECT SHSN.
WED...MAINLY VFR...BUT MVFR POSSIBLE TOWARD EVENING IN LGT SNOW.
THU AND FRIDAY...MVFR/IFR PSBL IN LGT SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP
NEAR TERM...DGM/MDP
SHORT TERM...DGM
LONG TERM...MLJ
AVIATION...MSE
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
945 PM EST MON FEB 6 2012
.SYNOPSIS...
A WEAK COASTAL LOW WILL TRACK NORTHEAST OFFSHORE OF THE CAROLINAS
OVERNIGHT INTO EARLY TUESDAY...MAINTAINING COOL AND CLOUDY WEATHER
CONDITIONS...ALONG WITH A FEW PATCHES OF LIGHT RAIN LATE TONIGHT.
DRY AND SEASONABLE WEATHER IS EXPECTED MUCH OF THE UPCOMING WEEK.
A POTENTIALLY STRONGER COASTAL LOW PRESSURE SYSTEM MAY IMPACT THE
AREA THIS UPCOMING WEEKEND...WITH A DRYING TREND ANTICIPATED INTO
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM MONDAY...LOCAL AND SURROUNDING 88D RADARS INDICATE
PATCHY LIGHT RAIN OR DRIZZLE ACROSS THE ILM CWA AT THE MOMENT.
LATEST HRRR RUN INDICATES BEST SHOT FOR ADDITIONAL PCPN ACROSS THE
ILM CWA WILL EXTEND THROUGH 1 AM. BEST UVVS SLIDE NE OF THE ILM CWA
AS WELL AS OFFSHORE FROM THE CAROLINAS. THE MID LEVEL S/W TROF SEEN
AT 5H...DOES NOT REALLY INTERACT WITH THE SFC LOW ALONG THE COASTAL
TROF UNTIL THE LOW IS NORTHEAST OF THE ILM CWA. WILL TREND THE POPS
LOWER AFTER 1 AM...WITH ALL PCPN EXITING NE OF THE AREA BY DAYBREAK
TUE. THE BACK-EDGE OF THE OVERCAST CLOUDS EXTENDS NE-SW ACROSS THE
CENTRAL CAROLINAS AT THE MOMENT. WITH TIME...SHOULD SEE THIS EDGE
REACH THE WESTERN PORTIONS OF THE ILM CWA BY DAYBREAK. HAVE MASSAGED
MIN TEMPS SLIGHTLY HIGHER EASTERN PORTIONS OF THE ILM CWA DUE TO THE
BLANKET OF CLOUDS. HOWEVER...CAA WILL BE OCCURRING DURING THE FEW
HRS LEADING UP TO DAYBREAK PER 8H TEMPS AND 1K-8H THICKNESSES BOTH
DECREASING.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...BY DAYBREAK TUESDAY PERHAPS LINGER CLOUDS AS
AN ELONGATED BUT WEAK COASTAL LOW OFFSHORE OF CAPE FEAR AND CAPE
LOOKOUT TRACKS NE. SUNSHINE HOWEVER WILL MAKE AN APPEARANCE ON
TUESDAY...AS LOW-LEVEL DRYING AND MID-LEVEL SUBSIDENCE ENSUES IN
WAKE OF ASSOCIATED AND DEPARTING SHORT-WAVE ENERGY ALOFT. WEAK
HIGH PRESSURE BUILDING FROM THE WEST WILL MAINTAIN A NORTH WIND
FLOW ACCOMPANIED BY MAXIMUM TEMPS JUST A FEW DEGREES ABOVE NORMAL
FOR FEBRUARY 7TH...ESSENTIALLY 60 FAR NORTHERN ZONES TO MID 60S
ACROSS THE SC INTERIOR ZONES. TUESDAY NIGHT MAINLY CLEAR SKIES
IN NEAR-ZONAL FLOW WITH MODERATE RADIATIONAL COOLING EXPECTED
UNDER LIGHT NORTHERLY WIND FLOW IN THE LOW-LEVELS...SO UPPER
30S TO LOWS 40S COAST LOOKS ON TARGET...PERHAPS LOW/MID 30S IN
OUR COLDER POCKETS.
WEDNESDAY FEATURES A FAIRLY SWIFT BUT DAMPENING SHORT-WAVE ALOFT
TRANSITING THE MIDDLE ATLANTIC REGION. NO RETURN FLOW ASSOCIATED
WITH THIS FEATURE...RATHER A RESURGENCE OF NORTH WIND FLOW INTO
WEDNESDAY EVENING AS SURFACE PRESSURE BUILDS IN WAKE OF THE DRY
WAVE ALOFT. EVEN COOL AIR ADVECTION ARRIVES LATE...LOWERING
THICKNESS VALUES MAY EQUATE TO MAX TEMPS QUITE SIMILAR TO THAT
OF TUESDAY...AROUND 60. SIMILARLY AND SEASONABLY COOL EARLY
THURSDAY WITH MINIMUMS IN THE UPPER 30S ACCOMPANIED BY MODERATE
N-NNE LOW-LEVEL WIND FLOW EARLY THURSDAY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...HIGH PRESSURE BUILDING DOWN OVER THE LOWER
MISSISSIPPI VALLEY WILL REINFORCE NORTHERLY FLOW OVER THE CAROLINAS
THROUGH EARLY FRI AS MID TO UPPER FLOW REMAINS FAIRLY ZONAL. AS SFC
HIGH PRESSURE SHIFTS EAST AND WEAKENS THROUGH FRI...AN ON SHORE TO
SOUTHERLY COMPONENT TO THE FLOW AT THE SURFACE WILL PROVIDE AN
INCREASE IN LOW LEVEL MOISTURE WHICH MAY TRANSLATE INTO SOME LOWER
LEVEL CLOUDS ON FRI...MAINLY ALONG THE COAST. WILL KEEP ANY MENTION
OF PCP CONFINED TO THE COASTAL WATERS AT THIS TIME. OTHERWISE COLUMN
REMAINS FAIRLY DRY FOR THE MOST PART WITH PCP WATER VALUES RUNNING A
HALF INCH OR LESS THROUGH FRIDAY. LOOKING AT SOUNDING DATA...MOST OF
THE MOISTURE WILL BE LOCKED WITHIN THE UPPER LEVELS ABOVE H4.
OVERALL EXPECT DECENT WEATHER THROUGH MID WEEK WITH SOME PASSING
HIGH CLOUDS AND TEMPS REACHING AROUND 60.
BY THE WEEKEND...H5 TROUGH DIGS DOWN THROUGH THE GREAT LAKES AND
MERGES WITH SOUTHERN STREAM TROUGH PRODUCING ONE HIGHER AMPLITUDE
TROUGH RUNNING DOWN THROUGH THE LOWER MISSISSIPPI VALLEY. THIS WILL
GUIDE A DEEPENING SFC LOW UP FROM THE GULF ON SATURDAY. GFS SHOWS
THIS LOW TRACKING ACROSS FLORIDA AND BRUSHING THE SOUTHEAST COAST AS
CENTER OF LOW REMAINS A GOOD DISTANCE OFF SHORE WHILE THE CMC KEEPS
TROUGH FARTHER WEST AND TRACKS THE LOW UP THROUGH THE SOUTHEAST
ALMOST DIRECTLY OVER CAPE FEAR SAT AFTN. THE ECMWF ACTUALLY DEVELOPS
A SFC LOW SAT MORNING OFF HATTERAS. FOR NOW WILL GO WITH MORE OF A
COMPROMISE BETWEEN GFS AND CANADIAN AS THESE MODELS HAVE BEEN MORE
CONSISTENT OVER THE PAST FEW DAYS WITH THIS LOW. EITHER WAY...SHOULD
REMAIN IN COOLER NORTHERLY FLOW AT THE SURFACE AS THIS SYSTEM MOVES
BY. IF PCP LASTS INTO SAT NIGHT MAY HAVE CONCERN FOR MIXED PCP AS
TEMPS DROP TO NEAR FREEZING BUT DRY AIR SHOULD MAKE IT IN.
COLD AND DRY AIR WILL BUILD IN BEHIND THIS SYSTEM AS IT TRACKS OFF
TO THE EAST NORTHEAST THROUGH SUNDAY. A DEEP NORTHWEST FLOW SETS UP
AS MID TO UPPER TROUGH MOVES OFF THE COAST ON SUNDAY...ALLOWING
LOCAL AREA TO TAP INTO MUCH COOLER AND DRIER AIR THROUGH EARLY NEXT
WEEK. TEMPS WILL ONLY MAKE IT INTO THE LOWER 50S AND BELOW FREEZING
IN MANY SPOTS SUN AND MON.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...WEAKENING HIGH PRESSURE IS SITUATED NORTHWEST OF THE
TERMINALS. A SURFACE LOW PRESSURE SYSTEM WILL PASS OFFSHORE THIS
EVENING AND OVERNIGHT. AS THE SYSTEM PASSES HIGH PRESSURE WILL
GRADUALLY REBUILD ACROSS THE TERMINALS.
THERE IS HIGH CONFIDENCE 2-3K CEILINGS AT FLO/LBT WILL IMPROVE TO
VFR LEVELS...ALTHOUGH CONFIDENCE IN EXACT TIMING IS LOW. VFR LEVEL
LOW CLOUDS AT FLO/LBT SHOULD BECOME SCATTERED SEVERAL HOURS AFTER
MIDNIGHT AS HIGH PRESSURE AND DRIER AIR BUILDS IN. THE LOWEST CLOUDS
AND HIGHEST CHANCE OF RAINFALL CAN BE EXPECTED AT THE COASTAL
TERMINALS DUE TO THE PROXIMITY TO THE PASSING SURFACE LOW.
CONFIDENCE IS MODERATE TO HIGH THAT 1-2K CEILINGS WILL AFFECT THE
COASTAL TERMINALS THIS EVENING. AT THE ILM TERMINALS IFR CEILINGS
COULD TEMPORARILY OCCUR BUT CONFIDENCE IS TOO LOW ATTM. MVFR
CEILINGS COULD IMPROVE TO VFR LEVELS SOONER THAN INDICATED IN TAFS
IF THE LOW PRESSURE AREA MOVES NORTHEAST QUICKER THAN ANTICIPATED.
VFR EXPECTED AFTER 12Z ALL TERMINALS WITH NORTH WINDS BECOMING
NORTHEAST TO EAST AS THE DAY PROGRESSES.
EXTENDED OUTLOOK...LOW CONFIDENCE FOR IFR/MORNING FOG FRIDAY. SLIGHT
CHANCE RAIN SATURDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM MONDAY...THE COASTAL TROF TO REMAIN EAST OF THE ILM
COASTAL WATERS PER LATEST NEAR TERM MODEL RUNS...IE THE HOURLY RUC
AND HRRR MODELS. LOOKING AT NE TO N WINDS NEAR 15 KT THRU THE
REMAINDER OF THE EVENING...BACKING TO NW TO N AFTER THE SFC LOW
PASSES BY THE WATERS. THE LOW TRACKING ALONG THE COASTAL TROF IS NOT
EXPECTED TO BOMB OR INTENSIFY ENOUGH TO FURTHER TIGHTEN THE SFC PG
ACROSS THE WATERS. AS A RESULT...WIND SPEEDS WILL REMAIN 15 KT OR
LESS INTO TUESDAY. SIGNIFICANT SEAS WILL RUN IN THE 2 TO 4 FOOT
RANGE...WITH A DOMINATE PERIOD OF 4 TO 6 SECONDS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY..MODERATE N-NE WINDS EARLY TUESDAY AS A COASTAL
LOW PULLS AWAY...THEN QUICKLY VEERING AND WEAKENING BY AFTERNOON.
THUS WE MAY SEE A FEW 4 FOOT SEAS ACROSS OUR OUTER WATERS...AND
2 TO 3 FEET INSHORE. SEAS WILL SUBSIDE IN THE AFTERNOON AS WINDS
ABATE. TAME SEAS OVERALL TUESDAY NIGHT THROUGH WEDNESDAY WITH SWAN
SPECTRAL DATA INDICATING LIGHT WIND-CHOP ACCOMPANIED BY A WEAK SE
SWELL. DRY FORECAST WITH NO PRECIPITATION OR VISIBILITY RESTRAINTS
EXPECTED. A SURGE OF N-NE WIND WILL GREET THE WATERS EARLY THU AS
HIGH PRESSURE BUILDS IN FROM THE WEST IN WAKE OF A FRONT PASSING
NORTH OF OUR WATERS.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...STRONG HIGH PRESSURE OVER THE LOWER MISSISSIPPI
VALLEY WILL SHIFT SLOWLY EAST AND WEAKEN THROUGH FRIDAY. OVERALL
EXPECT A WEAKENED GRADIENT FLOW WITH LIGHT NORTHERLY WINDS NO MORE
THAN 10 TO 15 KTS. WINDS WILL BECOME MORE VARIABLE ON FRIDAY WITH A
LIGHT ON SHORE FLOW DEVELOPING. SEAS WILL RUN 3 FT OR LESS THROUGH
FRIDAY. A SOUTHERN STREAM LOW WILL EVENTUALLY AFFECT THE LOCAL
WATERS BUT MODELS DIFFER IN TERMS OF TIMING AND INTENSITY BUT IT
LOOKS LIKE THE GRADIENT WILL TIGHTEN IN AN OFF SHORE FLOW AS LOW
SHOULD TRACK UP JUST EAST OF LOCAL WATERS. FOR NOW WILL MAINTAIN AN
INCREASING NW FLOW ON BACK END OF LOW ON SAT. THIS WILL PUSH SEAS UP
PRIMARILY IN THE OFF SHORE WATERS WITH LOCAL SEAS REMAINING CLOSER
TO 2 TO 4 FT. SHOULD EXPERIENCE A STRONG SURGE AS SYSTEM EXITS OFF
TO THE EAST NORTHEAST THROUGH SUNDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...DCH
SHORT TERM...MJC
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
645 PM EST MON FEB 6 2012
.SYNOPSIS...
A WEAK COASTAL LOW WILL TRACK NORTHEAST OFFSHORE OF THE CAROLINAS
OVERNIGHT INTO EARLY TUESDAY...MAINTAINING COOL AND CLOUDY WEATHER
CONDITIONS...ALONG WITH A FEW PATCHES OF LIGHT RAIN LATE TONIGHT.
DRY AND SEASONABLE WEATHER IS EXPECTED MUCH OF THE UPCOMING WEEK.
A POTENTIALLY STRONGER COASTAL LOW PRESSURE SYSTEM MAY IMPACT THE
AREA THIS UPCOMING WEEKEND...WITH A DRYING TREND ANTICIPATED INTO
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 PM MONDAY...LATEST 88D RADARS INDICATE PATCHY LIGHT RAIN
OR DRIZZLE ACROSS THE ILM CWA FOR THE MOMENT. CURRENT FORECAST
LOOKING AOK WITH REGARD TO PCPN PROBABILITY OVERNIGHT...ALONG WITH
LITTLE OR NO QPF ASSOCIATED WITH IT. NO CHANGES NEEDED AT THIS TIME.
WINDS WEST OF THE COASTAL TROF ARE MORE NORTHERLY AND A BIT MORE
ACTIVE ESPECIALLY ALONG THE IMMEDIATE COAST. HAVE ADJUSTED WINDS VIA
LATEST SFC OBS AND TRENDS...BUT CONTINUED TO BACK THEM TO THE NW
OVERNIGHT AS THE PREVIOUS FORECAST INDICATED. MIN TEMPS MAY NEED TO
BE BUMPED UP A CAT. WILL AWAIT FOR THE NEXT UPDATE TO CONFIRM.
PREVIOUS DISCUSSION..............................................
AS OF 3 PM MONDAY...WEDGE OF HIGH PRESSURE BEGINNING TO WEAKEN AS
EVIDENCED BY MSAS ANALYSIS AND 3-HOUR PRESSURE FALLS ACROSS MUCH OF
THE AREA. AT THE SAME TIME...TROUGH OF LOW PRESSURE BEGINNING TO
TAKE SHAPE JUST OFF THE GEORGIA COAST...WITH SOME ENHANCED CLOUD
COVER WELL SE OF KSAV SUGGESTING POTENTIAL SURFACE CYCLOGENESIS
BEGINNING IN THAT VICINITY. THIS HAS BEEN MODELED WELL TODAY...AND
AS THE UPPER IMPULSE CONTINUES EAST ACROSS THE SOUTHEAST AND
INTERACTS WITH THE RESIDUAL COLD FRONT...MORE DEVELOPMENT OF THIS
SURFACE FEATURE IS LIKELY. THIS LOW PRESSURE WILL JUST SKIRT THE
GRAND STRAND AND CAPE FEAR COAST OVERNIGHT BEFORE PUSHING OFF TO THE
NORTHEAST BY MORNING.
HAVE SEEN VERY LITTLE IN THE WAY OF PRECIP THUS FAR TODAY...BUT HIGH
RES REFLECTIVITY GUIDANCE STILL DEPICTING LIGHT RAIN OVERSPREADING
THE REGION FROM SW TO NE THIS EVE...AND ESPECIALLY TONIGHT. THIS
WILL OCCUR AS A BRIEF OVERRUNNING EVENT...DUE TO ENHANCED MOIST LIFT
ALONG THE 290K THETA SURFACE. STILL...THE BEST UPGLIDE WILL OCCUR
BETWEEN 5PM AND 6AM...SLIGHTLY SLOWER THAN PREVIOUSLY
ANTICIPATED...BUT WITH THE HEAVIEST SHOWERS...MEANING A FEW
HUNDREDTHS OF AN INCH OF QPF...EXPECTED TO IMPACT THE NORTHERN
ZONES. AS THE AFOREMENTIONED SURFACE LOW MOVES ALONG THE
COAST...WINDS WILL BACK FROM NE TO NW...MAKING THE FLOW MORE
PARALLEL TO THE PRESSURE SURFACES ON THE 290K THETA...HENCE BRINGING
AN END TO ANY LIFT. POP ECHOES THIS TREND...WITH CHC ACROSS THE
NORTHERN ZONES EARLY TONIGHT...BECOMING SILENT EVERYWHERE BY
MORNING. THE COMBINATION OF DRIER AIR AND NW FLOW WILL ALLOW MINS TO
FALL INTO THE UPPER 30S WELL NW...TO THE LOW 40S NEAR THE
COAST...EVEN WITH AMPLE CLOUD COVER PERSISTING.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...BY DAYBREAK TUESDAY PERHAPS LINGER CLOUDS AS
AN ELONGATED BUT WEAK COASTAL LOW OFFSHORE OF CAPE FEAR AND CAPE
LOOKOUT TRACKS NE. SUNSHINE HOWEVER WILL MAKE AN APPEARANCE ON
TUESDAY...AS LOW-LEVEL DRYING AND MID-LEVEL SUBSIDENCE ENSUES IN
WAKE OF ASSOCIATED AND DEPARTING SHORT-WAVE ENERGY ALOFT. WEAK
HIGH PRESSURE BUILDING FROM THE WEST WILL MAINTAIN A NORTH WIND
FLOW ACCOMPANIED BY MAXIMUM TEMPS JUST A FEW DEGREES ABOVE NORMAL
FOR FEBRUARY 7TH...ESSENTIALLY 60 FAR NORTHERN ZONES TO MID 60S
ACROSS THE SC INTERIOR ZONES. TUESDAY NIGHT MAINLY CLEAR SKIES
IN NEAR-ZONAL FLOW WITH MODERATE RADIATIONAL COOLING EXPECTED
UNDER LIGHT NORTHERLY WIND FLOW IN THE LOW-LEVELS...SO UPPER
30S TO LOWS 40S COAST LOOKS ON TARGET...PERHAPS LOW/MID 30S IN
OUR COLDER POCKETS.
WEDNESDAY FEATURES A FAIRLY SWIFT BUT DAMPENING SHORT-WAVE ALOFT
TRANSITING THE MIDDLE ATLANTIC REGION. NO RETURN FLOW ASSOCIATED
WITH THIS FEATURE...RATHER A RESURGENCE OF NORTH WIND FLOW INTO
WEDNESDAY EVENING AS SURFACE PRESSURE BUILDS IN WAKE OF THE DRY
WAVE ALOFT. EVEN COOL AIR ADVECTION ARRIVES LATE...LOWERING
THICKNESS VALUES MAY EQUATE TO MAX TEMPS QUITE SIMILAR TO THAT
OF TUESDAY...AROUND 60. SIMILARLY AND SEASONABLY COOL EARLY
THURSDAY WITH MINIMUMS IN THE UPPER 30S ACCOMPANIED BY MODERATE
N-NNE LOW-LEVEL WIND FLOW EARLY THURSDAY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...HIGH PRESSURE BUILDING DOWN OVER THE LOWER
MISSISSIPPI VALLEY WILL REINFORCE NORTHERLY FLOW OVER THE CAROLINAS
THROUGH EARLY FRI AS MID TO UPPER FLOW REMAINS FAIRLY ZONAL. AS SFC
HIGH PRESSURE SHIFTS EAST AND WEAKENS THROUGH FRI...AN ON SHORE TO
SOUTHERLY COMPONENT TO THE FLOW AT THE SURFACE WILL PROVIDE AN
INCREASE IN LOW LEVEL MOISTURE WHICH MAY TRANSLATE INTO SOME LOWER
LEVEL CLOUDS ON FRI...MAINLY ALONG THE COAST. WILL KEEP ANY MENTION
OF PCP CONFINED TO THE COASTAL WATERS AT THIS TIME. OTHERWISE COLUMN
REMAINS FAIRLY DRY FOR THE MOST PART WITH PCP WATER VALUES RUNNING A
HALF INCH OR LESS THROUGH FRIDAY. LOOKING AT SOUNDING DATA...MOST OF
THE MOISTURE WILL BE LOCKED WITHIN THE UPPER LEVELS ABOVE H4.
OVERALL EXPECT DECENT WEATHER THROUGH MID WEEK WITH SOME PASSING
HIGH CLOUDS AND TEMPS REACHING AROUND 60.
BY THE WEEKEND...H5 TROUGH DIGS DOWN THROUGH THE GREAT LAKES AND
MERGES WITH SOUTHERN STREAM TROUGH PRODUCING ONE HIGHER AMPLITUDE
TROUGH RUNNING DOWN THROUGH THE LOWER MISSISSIPPI VALLEY. THIS WILL
GUIDE A DEEPENING SFC LOW UP FROM THE GULF ON SATURDAY. GFS SHOWS
THIS LOW TRACKING ACROSS FLORIDA AND BRUSHING THE SOUTHEAST COAST AS
CENTER OF LOW REMAINS A GOOD DISTANCE OFF SHORE WHILE THE CMC KEEPS
TROUGH FARTHER WEST AND TRACKS THE LOW UP THROUGH THE SOUTHEAST
ALMOST DIRECTLY OVER CAPE FEAR SAT AFTN. THE ECMWF ACTUALLY DEVELOPS
A SFC LOW SAT MORNING OFF HATTERAS. FOR NOW WILL GO WITH MORE OF A
COMPROMISE BETWEEN GFS AND CANADIAN AS THESE MODELS HAVE BEEN MORE
CONSISTENT OVER THE PAST FEW DAYS WITH THIS LOW. EITHER WAY...SHOULD
REMAIN IN COOLER NORTHERLY FLOW AT THE SURFACE AS THIS SYSTEM MOVES
BY. IF PCP LASTS INTO SAT NIGHT MAY HAVE CONCERN FOR MIXED PCP AS
TEMPS DROP TO NEAR FREEZING BUT DRY AIR SHOULD MAKE IT IN.
COLD AND DRY AIR WILL BUILD IN BEHIND THIS SYSTEM AS IT TRACKS OFF
TO THE EAST NORTHEAST THROUGH SUNDAY. A DEEP NORTHWEST FLOW SETS UP
AS MID TO UPPER TROUGH MOVES OFF THE COAST ON SUNDAY...ALLOWING
LOCAL AREA TO TAP INTO MUCH COOLER AND DRIER AIR THROUGH EARLY NEXT
WEEK. TEMPS WILL ONLY MAKE IT INTO THE LOWER 50S AND BELOW FREEZING
IN MANY SPOTS SUN AND MON.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...WEAKENING HIGH PRESSURE IS SITUATED NORTHWEST OF THE
TERMINALS. A SURFACE LOW PRESSURE SYSTEM WILL PASS OFFSHORE THIS
EVENING AND OVERNIGHT. AS THE SYSTEM PASSES HIGH PRESSURE WILL
GRADUALLY REBUILD ACROSS THE TERMINALS.
THERE IS HIGH CONFIDENCE 2-3K CEILINGS AT FLO/LBT WILL IMPROVE TO
VFR LEVELS...ALTHOUGH CONFIDENCE IN EXACT TIMING IS LOW. VFR LEVEL
LOW CLOUDS AT FLO/LBT SHOULD BECOME SCATTERED SEVERAL HOURS AFTER
MIDNIGHT AS HIGH PRESSURE AND DRIER AIR BUILDS IN. THE LOWEST CLOUDS
AND HIGHEST CHANCE OF RAINFALL CAN BE EXPECTED AT THE COASTAL
TERMINALS DUE TO THE PROXIMITY TO THE PASSING SURFACE LOW.
CONFIDENCE IS MODERATE TO HIGH THAT 1-2K CEILINGS WILL AFFECT THE
COASTAL TERMINALS THIS EVENING. AT THE ILM TERMINALS IFR CEILINGS
COULD TEMPORARILY OCCUR BUT CONFIDENCE IS TOO LOW ATTM. MVFR
CEILINGS COULD IMPROVE TO VFR LEVELS SOONER THAN INDICATED IN TAFS
IF THE LOW PRESSURE AREA MOVES NORTHEAST QUICKER THAN ANTICIPATED.
VFR EXPECTED AFTER 12Z ALL TERMINALS WITH NORTH WINDS BECOMING
NORTHEAST TO EAST AS THE DAY PROGRESSES.
EXTENDED OUTLOOK...LOW CONFIDENCE FOR IFR/MORNING FOG FRIDAY. SLIGHT
CHANCE RAIN SATURDAY. OTHERWISE VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 645 PM MONDAY...THE COASTAL TROF TO REMAIN EAST OF THE ILM
COASTAL WATERS PER LATEST NEAR TERM MODEL RUNS...IE THE HOURLY RUC
AND HRRR MODELS. LOOKING AT NE TO N WINDS NEAR 15 KT THRUOUT THE
NIGHT. SFC LOW DEVELOPING AND TRACKING ALONG THE COASTAL TROF IS NOT
EXPECTED TO BOMB OR INTENSIFY ENOUGH TO TIGHTEN THE SFC PG. AS A
RESULT...WIND SPEEDS WILL REMAIN 15 KT OR LESS INTO TUESDAY.
PREVIOUS DISCUSSION..............................................
AS OF 3 PM MONDAY...MODERATE NE WINDS OF AROUND 10 KTS WILL EASE
THROUGH THE EVE BEFORE INCREASING SLIGHTLY AND BACKING TO THE NW
TONIGHT. THIS IS IN RESPONSE TO A DEVELOPING SURFACE LOW WHICH WILL
MOVE UP THE COAST FROM OFF GEORGIA. SEAS CURRENTLY ARE RUNNING 3-4
FT...AND THESE SEAS ARE EXPECTED TO PERSIST THROUGH MORNING. SLIGHT
ENHANCEMENT IN WAVE AMPLITUDE POSSIBLE AS WINDS PICK UP TONIGHT DUE
TO TIGHTENING PRESSURE GRADIENT NEAR THE SURFACE LOW...BUT STILL
REMAIN PREDOMINANTLY 3-4 FT. AS WINDS BACK FROM NE TO NW
TONIGHT...SOME CONFUSED SEAS ARE POSSIBLE DUE TO WIND WAVES
DOMINATING THE SPECTRUM...BUT WITH SPEEDS AND AMPLITUDES REMAINING
LOW...NO MAJOR NAVIGATIONAL IMPACTS ARE ANTICIPATED. A FEW HEAVIER
SHOWERS WILL POSSIBLY CREATE SOME LOWERED VISIBILITIES THROUGH THE
NIGHT...ESPECIALLY IN THE OUTER 20 NM WATERS...BUT THESE WILL BE
ISOLATED.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY..MODERATE N-NE WINDS EARLY TUESDAY AS A COASTAL
LOW PULLS AWAY...THEN QUICKLY VEERING AND WEAKENING BY AFTERNOON.
THUS WE MAY SEE A FEW 4 FOOT SEAS ACROSS OUR OUTER WATERS...AND
2 TO 3 FEET INSHORE. SEAS WILL SUBSIDE IN THE AFTERNOON AS WINDS
ABATE. TAME SEAS OVERALL TUESDAY NIGHT THROUGH WEDNESDAY WITH SWAN
SPECTRAL DATA INDICATING LIGHT WIND-CHOP ACCOMPANIED BY A WEAK SE
SWELL. DRY FORECAST WITH NO PRECIPITATION OR VISIBILITY RESTRAINTS
EXPECTED. A SURGE OF N-NE WIND WILL GREET THE WATERS EARLY THU AS
HIGH PRESSURE BUILDS IN FROM THE WEST IN WAKE OF A FRONT PASSING
NORTH OF OUR WATERS.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...STRONG HIGH PRESSURE OVER THE LOWER MISSISSIPPI
VALLEY WILL SHIFT SLOWLY EAST AND WEAKEN THROUGH FRIDAY. OVERALL
EXPECT A WEAKENED GRADIENT FLOW WITH LIGHT NORTHERLY WINDS NO MORE
THAN 10 TO 15 KTS. WINDS WILL BECOME MORE VARIABLE ON FRIDAY WITH A
LIGHT ON SHORE FLOW DEVELOPING. SEAS WILL RUN 3 FT OR LESS THROUGH
FRIDAY. A SOUTHERN STREAM LOW WILL EVENTUALLY AFFECT THE LOCAL
WATERS BUT MODELS DIFFER IN TERMS OF TIMING AND INTENSITY BUT IT
LOOKS LIKE THE GRADIENT WILL TIGHTEN IN AN OFF SHORE FLOW AS LOW
SHOULD TRACK UP JUST EAST OF LOCAL WATERS. FOR NOW WILL MAINTAIN AN
INCREASING NW FLOW ON BACK END OF LOW ON SAT. THIS WILL PUSH SEAS UP
PRIMARILY IN THE OFF SHORE WATERS WITH LOCAL SEAS REMAINING CLOSER
TO 2 TO 4 FT. SHOULD EXPERIENCE A STRONG SURGE AS SYSTEM EXITS OFF
TO THE EAST NORTHEAST THROUGH SUNDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MJC
NEAR TERM...DCH/JDW
SHORT TERM...MJC
LONG TERM...RGZ
AVIATION...MRR
AREA FORECAST DISCUSSION...CORRECTED
NWS BISMARCK ND
432 AM CST SUN FEB 5 2012
.SHORT TERM...TODAY THROUGH MONDAY...
THE CHALLENGE FOR THE MORNING IS ONCE AGAIN PREDICTING THE
DISSIPATION OF FOG AND LOW STRATUS CONFINED MOSTLY TO AREAS ALONG
AND NORTH AND EAST OF THE MISSOURI RIVER. THE DETERMINISTIC
MODELS ARE HAVING A VERY DIFFICULT TIMING RESOLVING THE
STRATUS...WITH THE 06 UTC HRRR THE ONLY MODEL WITH A HANDLE ON THE
EVENT...SUGGESTING DISSIPATION OF THE FOG AND STRATUS BY EARLY
AFTERNOON AT THE LATEST AS MIXING INCREASING AHEAD OF A SURFACE
TROUGH. HAVE TRENDED SLIGHTLY FASTER THAN THE
HRRR...HOWEVER...MUCH UNCERTAINTY AS TO WHEN THE STRATUS WILL
COMPLETELY DISSIPATE DOES REMAIN. HAVE REMOVED MORTON AND SIOUX
COUNTIES FROM THE DENSE FOG ADVISORY...AND WILL LEAVE THE
REMAINING COUNTIES IN PLACE THROUGH 15 UTC. TWO OTHER PATCHES OF
DENSE FOG ARE BEING OBSERVED AS OF 09 UTC...INCLUDING THE
WILLISTON THROUGH TIOGA AREAS AND RUGBY THROUGH BOTTINEAU. DUE TO
THE VERY LOCALIZED NATURE OF THESE AREAS...WILL COVER WITH AN SPS.
A VERY MILD EARLY FEBRUARY DAY IS FORECAST ACROSS WESTERN AND
CENTRAL NORTH DAKOTA TODAY DUE IN LARGE PART TO THE ABSENCE OF SNOW
COVER ACROSS THE AREA. THE ABUNDANCE OF BROWN GROUND WILL YIELD
GREATER MIXING HEIGHTS ENABLING THE RELATIVELY MILD TEMPERATURES IN
THE 850-800 MB LAYER OF +4 TO +6 C TO BE MIXED TO THE
SURFACE...RESULTING IN WIDESPREAD 50S FOR HIGH TEMPERATURES FOR MOST
AREAS...ESPECIALLY ALONG AND SOUTH OF THE MISSOURI RIVER...WITH
UPPER 40S FOR HIGHS FOR THE JAMES RIVER VALLEY...TURTLE MOUNTAINS
AND LOCATIONS ALONG THE INTERNATIONAL BORDER. TRENDED WELL ABOVE
THE DETERMINISTIC AND STATISTICAL CONSENSUS AND OPTED FOR THE SUPERIOR
VERIFICATION OF BIAS CORRECTED GUIDANCE GIVEN THE BROWN WINTER WE
ARE HAVING. SHOWN BELOW ARE THE FORECAST HIGHS AND RECORD HIGHS
FOR TODAY FOR THE MAJOR OBSERVING LOCATIONS. SEE THE FIRE WEATHER
DISCUSSION BELOW REGARDING FIRE DANGER FOR TODAY.
LOCATION........FORECAST...........RECORD
BISMARCK..........53...............56 1991
JAMESTOWN.........49...............58 1991
MINOT.............54...............58 1963
WILLISTON.........51...............55 1963
DICKINSON.........54...............58 1963
A SURFACE COLD FRONT IS FORECAST TO CROSS THE INTERNATIONAL BORDER
AROUND 00 UTC THIS EVENING AND PROPAGATE SOUTH THROUGH THE
NIGHT...ENTERING SOUTH DAKOTA BETWEEN 08 AND 10 UTC. GIVEN POST
FRONTAL MIXING AND WARM TEMPERATURES TO BEGIN THE OVERNIGHT...LOW
TEMPERATURES SUNDAY NIGHT SHOULD ONLY FALL INTO THE LOW 20S FOR MOST
LOCATIONS...WITH TEENS ALONG THE INTERNATIONAL BORDER. A BREEZY
MONDAY IS EXPECTED IN THE WAKE OF THE COLD FRONT AS 1045 MB SURFACE
HIGH BEGINS TO BUILD INTO THE STATE. AIDED BY AN AN ISALLOBARIC
COMPONENT FROM PRESSURE RISES AND LOW LEVEL COLD AIR ADVECTION
PROMOTING MIXING TO AROUND 825 MB...NORTHERLY WIND GUSTS TO 25 KTS
ARE EXPECTED FOR MOST AREAS WITH FLURRIES ASSOCIATED WITH STRATUS
APPROXIMATELY ALONG AND NORTH OF A LINE FROM CROSBY THROUGH
WASHBURN THROUGH EDGELEY. DESPITE THE COLD FRONTAL
PASSAGE...TEMPERATURES ON MONDAY WILL STILL BE ABOVE NORMAL THANKS
TO NO SNOWPACK WITH HIGHS FROM THE LOW TO MID 20S NORTH TO THE
LOWER 30S SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
MODELS IN FAIR AGREEMENT WITH FEATURES IN LONG TERM. USED THE BLEND
WITH FEW CHANGES. LARGE MID AND UPPER LEVEL RIDGE LIES ALONG SPINE
OF THE ROCKIES WITH FAIRLY STRONG HIGH PRESSURE DROPPING SOUTH IN
LEE OF CANADIAN ROCKIES. 1044 HIGH WOULD INDICATE A VERY CHILLY
MIDDLE OF THE WEEK...HOWEVER WITH NO SIGNIFICANT SNOW COVER UPSTREAM
FROM THE THE CENTRAL ALBERTA AND SASKATCHEWAN BORDER...SOUTH THROUGH
THE NORTHERN PLAINS...TEMPERATURES WILL BE NORMAL OR SEVERAL DEGREES
ABOVE NORMAL.
ONLY ONE CHANCE OF ACCUMULATING PRECIPITATION WHICH WILL COME
WEDNESDAY NIGHT AS A REINFORCING SHOT OF MODIFIED ARCTIC AIR MOVES
SOUTH BEHIND A COLD FRONT. THE SYSTEM LOOKS QUITE DRY AND THE
HIGHEST POPS...SLIGHT CHANCE...ARE IN THAT PERIOD. WHILE AIR WILL BE
COLDER...THICKNESS AND 85H TEMPERATURES INDICATE THAT THE COLDEST
AIR WILL PASS JUST TO THE EAST OF THE FORECAST AREA BORDER.
&&
.AVIATION...
BAND OF STRATUS EXTENDS ABOUT 50 MILES EITHER SIDE OF MISSOURI
VALLEY FROM THE SOUTH DAKOTA BORDER NORTH TO NEAR LAKE
SAKAKAWEA...THEN NORTHEAST TO WILLISTON. SEVERAL OTHER MUCH SMALLER
BANDS LINGERED OVER EASTERN PORTIONS OF THE FORECAST AREA...KJMS AND
EAST AND KRUG AND EAST. THE AREAS SHOWED LITTLE MOVEMENT...BUT WERE
SLOWLY SHRINKING IN AREAL COVERAGE. HOWEVER THE MISSOURI VALLEY
ESPECIALLY FROM KBIS TO KISN WILL LINGER IN LIFR CONDITIONS FOR
SEVERAL MORE HOURS BEFORE A TRANSITION OF VFR BY THE AFTERNOON ALL
AERODROME SITES.
&&
.FIRE WEATHER...
SUNDAY LOOKS TO BE VERY MILD ACROSS WESTERN AND CENTRAL NORTH
DAKOTA WITH HIGHS IN 50S. WITH PLENTIFUL DRY VEGETATION IN
PLACE...AND AFTERNOON RELATIVE HUMIDITY VALUES EXPECTED TO FALL
INTO THE 25 TO 35 PERCENT RANGE ESPECIALLY ALONG AND SOUTH OF THE
MISSOURI RIVER...THE ONE THING PREVENTING FIRE WEATHER CONCERNS
ARE WIND SPEEDS ONLY ON THE ORDER OF 10 TO 15 MPH.
HOWEVER...THE FIRE DANGER ON MONDAY IS FORECAST TO BE MEDIUM TO
HIGH ACROSS THE AREA...WITH NORTHERLY WINDS OF 20 TO 30 MPH BEHIND
A COLD FRONT...WITH HIGH TEMPERATURES IN THE UPPER 20S TO LOWER 30S.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR NDZ035>037-
046-047-050.
&&
$$
SHORT TERM/FIRE...PJA
LONG TERM/AVIATION....HW
AREA FORECAST DISCUSSION
NWS BISMARCK ND
329 AM CST SUN FEB 5 2012
.SHORT TERM...TODAY THROUGH MONDAY...
THE CHALLENGE FOR THE MORNING IS ONCE AGAIN PREDICTING THE
DISSIPATION OF FOG AND LOW STRATUS CONFINED MOSTLY TO AREAS ALONG
AND NORTH AND EAST OF THE MISSOURI RIVER. THE DETERMINISTIC
MODELS ARE HAVING A VERY DIFFICULT TIMING RESOLVING THE
STRATUS...WITH THE 06 UTC HRRR THE ONLY MODEL WITH A HANDLE ON THE
EVENT...SUGGESTING DISSIPATION OF THE FOG AND STRATUS BY EARLY
AFTERNOON AT THE LATEST AS MIXING INCREASING AHEAD OF A SURFACE
TROUGH. HAVE TRENDED SLIGHTLY FASTER THAN THE
HRRR...HOWEVER...MUCH UNCERTAINTY AS TO WHEN THE STRATUS WILL
COMPLETELY DISSIPATE DOES REMAIN. HAVE REMOVED MORTON AND SIOUX
COUNTIES FROM THE DENSE FOG ADVISORY...AND WILL LEAVE THE
REMAINING COUNTIES IN PLACE THROUGH 15 UTC. TWO OTHER PATCHES OF
DENSE FOG ARE BEING OBSERVED AS OF 09 UTC...INCLUDING THE
WILLISTON THROUGH TIOGA AREAS AND RUGBY THROUGH BOTTINEAU. DUE TO
THE VERY LOCALIZED NATURE OF THESE AREAS...WILL COVER WITH AN SPS.
A VERY MILD EARLY FEBRUARY DAY IS FORECAST ACROSS WESTERN AND
CENTRAL NORTH DAKOTA TODAY DUE IN LARGE PART TO THE ABSENCE OF SNOW
COVER ACROSS THE AREA. THE ABUNDANCE OF BROWN GROUND WILL YIELD
GREATER MIXING HEIGHTS ENABLING THE RELATIVELY MILD TEMPERATURES IN
THE 850-800 MB LAYER OF +4 TO +6 C TO BE MIXED TO THE
SURFACE...RESULTING IN WIDESPREAD 50S FOR HIGH TEMPERATURES FOR MOST
AREAS...ESPECIALLY ALONG AND SOUTH OF THE MISSOURI RIVER...WITH
UPPER 40S FOR HIGHS FOR THE JAMES RIVER VALLEY...TURTLE MOUNTAINS
AND LOCATIONS ALONG THE INTERNATIONAL BORDER. TRENDED WELL ABOVE
THE DETERMINISTIC AND STATISTICAL CONSENSUS AND OPTED FOR THE SUPERIOR
VERIFICATION OF BIAS CORRECTED GUIDANCE GIVEN THE BROWN WINTER WE
ARE HAVING. SHOWN BELOW ARE THE FORECAST HIGHS AND RECORD HIGHS
FOR TODAY FOR THE MAJOR OBSERVING LOCATIONS. SEE THE FIRE WEATHER
DISCUSSION BELOW REGARDING FIRE DANGER FOR TODAY.
LOCATION........FORECAST...........RECORD
BISMARCK..........53...............56 1991
JAMESTOWN.........49...............58 1991
MINOT.............54...............58 1963
WILLISTON.........51...............55 1963
DICKINSON.........54...............58 1963
A SURFACE COLD FRONT IS FORECAST TO CROSS THE INTERNATIONAL BORDER
AROUND 00 UTC THIS EVENING AND PROPAGATE SOUTH THROUGH THE
NIGHT...ENTERING SOUTH DAKOTA BETWEEN 08 AND 10 UTC. GIVEN POST
FRONTAL MIXING AND WARM TEMPERATURES TO BEGIN THE OVERNIGHT...LOW
TEMPERATURES SUNDAY NIGHT SHOULD ONLY FALL INTO THE LOW 20S FOR MOST
LOCATIONS...WITH TEENS ALONG THE INTERNATIONAL BORDER. A BREEZY
MONDAY IS EXPECTED IN THE WAKE OF THE COLD FRONT AS 1045 MB SURFACE
HIGH BEGINS TO BUILD INTO THE STATE. AIDED BY AN AN ISALLOBARIC
COMPONENT FROM PRESSURE RISES AND LOW LEVEL COLD AIR ADVECTION
PROMOTING MIXING TO AROUND 825 MB...NORTHERLY WIND GUSTS TO 25 KTS
ARE EXPECTED FOR MOST AREAS WITH FLURRIES ASSOCIATED WITH STRATUS
APPROXIMATELY ALONG AND NORTH OF A LINE FROM CROSBY THROUGH
WASHBURN THROUGH EDGELEY. DESPITE THE COLD FRONTAL
PASSAGE...TEMPERATURES ON MONDAY WILL STILL BE ABOVE NORMAL THANKS
TO NO SNOWPACK WITH HIGHS FROM THE LOW TO MID 20S NORTH TO THE
LOWER 30S SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
MODELS IN FAIR AGREEMENT WITH FEATURES IN LONG TERM. USED THE BLEND
WITH FEW CHANGES. LARGE MID AND UPPER LEVEL RIDGE LIES ALONG SPINE
OF THE ROCKIES WITH FAIRLY STRONG HIGH PRESSURE DROPPING SOUTH IN
LEE OF CANADIAN ROCKIES. 1044 HIGH WOULD INDICATE A VERY CHILLY
MIDDLE OF THE WEEK...HOWEVER WITH NO SIGNIFICANT SNOW COVER UPSTREAM
FROM THE THE CENTRAL ALBERTA AND SASKATCHEWAN BORDER...SOUTH THROUGH
THE NORTHERN PLAINS...TEMPERATURES WILL BE NORMAL OR SEVERAL DEGREES
ABOVE NORMAL.
ONLY ONE CHANCE OF ACCUMULATING PRECIPITATION WHICH WILL COME
WEDNESDAY NIGHT AS A REINFORCING SHOT OF MODIFIED ARCTIC AIR MOVES
SOUTH BEHIND A COLD FRONT. THE SYSTEM LOOKS QUITE DRY AND THE
HIGHEST POPS...SLIGHT CHANCE...ARE IN THAT PERIOD. WHILE AIR WILL BE
COLDER...THICKNESS AND 85H TEMPERATURES INDICATE THAT THE COLDEST
AIR WILL PASS JUST TO THE EAST OF THE FORECAST AREA BORDER.
&&
.AVIATION...
BAND OF STRATUS EXTENDS ABOUT 50 MILES EITHER SIDE OF MISSOURI
VALLEY FROM THE SOUTH DAKOTA BORDER NORTH TO NEAR LAKE
SAKAKAWEA...THEN NORTHEAST TO WILLISTON. SEVERAL OTHER MUCH SMALLER
BANDS LINGERED OVER EASTERN PORTIONS OF THE FORECAST AREA...KJMS AND
EAST AND KRUG AND EAST. THE AREAS SHOWED LITTLE MOVEMENT...BUT WERE
SLOWLY SHRINKING IN AREAL COVERAGE. HOWEVER THE MISSOURI VALLEY
ESPECIALLY FROM KBIS TO KISN WILL LINGER IN LIFR CONDITIONS FOR
SEVERAL MORE HOURS BEFORE A TRANSITION OF VFR BY THE AFTERNOON ALL
AERODROME SITES.
&&
.FIRE WEATHER...
SUNDAY LOOKS TO BE VERY MILD ACROSS WESTERN AND CENTRAL NORTH
DAKOTA WITH HIGHS IN 50S. WITH PLENTIFUL DRY VEGETATION IN
PLACE...AND AFTERNOON RELATIVE HUMIDITY VALUES EXPECTED TO FALL
INTO THE 25 TO 35 PERCENT RANGE ESPECIALLY ALONG AND SOUTH OF THE
MISSOURI RIVER...THE ONE THING PREVENTING FIRE WEATHER CONCERNS
ARE WIND SPEEDS ONLY ON THE ORDER OF 10 TO 15 MPH.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR NDZ035>037-
046-047-050.
&&
$$
SHORT TERM/FIRE...PJA
LONG TERM/AVIATION....HW
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1019 AM EST SUN FEB 5 2012
.SYNOPSIS...
HIGH PRESSURE BUILDS IN TODAY. COLD FRONT PASSES TUESDAY NIGHT
FOLLOWED BY A WEAK WAVE MIDWEEK. ANOTHER COLD FRONT CROSSES FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...
FINED TUNED CLEARING LINE FOR THE AFTERNOON AND ADJUSTED
TEMPERATURES UP N / DOWN S. OTHERWISE FCST ON TRACK WITH THE LAST
OF THE LIGHT PRECIPITATION / DRIZZLE WINDING DOWN.
730 AM UPDATE...
ADJUSTED POPS TO BETTER HANDLE LAST BAND OF RAIN PUSHING DOWN FROM
THE N...ASSOCIATED WITH FRONT UP AROUND H85 LEVEL. ALSO ADDED
DRIZZLE AND AREAS OF FOG. OTHERWISE FORECAST ON TRACK INCLUDING
CLEARING TREND FROM N TO S ON DRY ADVECTION BEHIND FRONT PUSHING
SAME DIRECTION.
PREV DISCN...
CONSIDERABLE DIFFERENCES BETWEEN THE NAM AND GFS WITH THE HANDLING
OF THE LOW LEVEL MOISTURE TODAY. RUC SUPPORTS THE FASTER CLEARING
FOUND IN THE GFS. THEREFORE WILL LEAN MORE TOWARD THE FASTER
SOLUTION. WITH CALM WINDS TONIGHT AND DECENT RADIATION
CONDITIONS...WILL GO TOWARD THE LOWER END OF THE MOS GUIDANCE. WILL
ALSO INCLUDE VALLEY FOG.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MDLS ARE STARTING TO CONVERGE ON HANDLING OF UPR LOW POISED TO MOVE
THRU ON MON. NAM/SREF CONT TO OPEN THIS UP INTO A WAVE ON
APPROACH...WITH REMAINDER OF GLOBAL MDLS KEEPING A STRONGER INTACT
CLOSED LOW AT H5. WILL FOLLOW HPC PREFERENCE FOR A ECWMF/GFS
BLEND...NOTING NAM TO BE AN OUTLIER ATTM. GIVEN THAT...WILL INCREASE
CLDS ACROSS S BY 18Z...WITH MOISTENING OF THE COLUMN THRU H7. WEAK
LIFT IN THIS LAYER AIDED BY UPR LOW SHOULD ALLOW LIGHT PRECIPITATION
TO BREAK OUT ACROSS SW VA...SOUTHERN COAL FIELDS AND SOUTHERN AND
CENTRAL WV MTNS BY AFTN. GLOBAL MDLS DO INDICATE QPF WITH
THIS...ALBEIT VERY LIGHT. THEREFORE...INTRODUCED CHC POPS ACROSS
AFOREMENTIONED AREAS...MAINLY FOR AFTN AND EARLY EVE. TEMP PROFILES
SUPPORT MAINLY LIQUID...PERHAPS ENDING AS A FEW WET FLAKES ACROSS
THE MTNS EARLY EVE. WILL SEE A SHARP LINE BETWEEN SUN AND CLDS.
THINK AREAS NORTH OF I64 CORRIDOR WILL SEE MAINLY SUNSHINE.
LOOKING AT QUIET WX FOR TUE UNDER SFC HIGH. A S/W TROF MAY BRING A
FEW SHRA/SHSN TO THE AREA WED. IF NOTHING ELSE...WILL INCREASE THE
CLDS.
GUIDANCE VERY SIMILAR TO INHERITED NUMBERS...SO LITTLE CHANGE
NECESSARY. HOWEVER...MAY SEE SOMEWHAT OF A TEMP GRADIENT MON WHERE
SE OH AND NORTHERN WV ENDS UP WARMER THAN SOUTHERN AREAS DUE TO CLDS.
OVERALL LOOKING AT AN ABV NORMAL PERIOD THRU MIDWEEK...NOTHING NEW
THIS WINTER.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
ZONAL FLOW TO START TRANSITIONS TO NW FLOW THIS PERIOD AS LONG WAVE
TROUGH AMPLIFIES IN THE E. THIS LONG WAVE WILL LIKELY BE TRANSIENT
AGAIN THOUGH PER ONGOING LACK OF HIGH LATITUDE BLOCKING...TO WHICH
THE LACK OF DEEP PENETRATION OF ARCTIC AIR DOWN INTO THE EASTERN
CONUS IS ALSO ATTRIBUTABLE.
PERIOD STARTS DRY TUE NT WITH HIGH PRESSURE GIVING WAY TO A MOISTURE
STARVED COLD FRONT WITH NO INFLOW FROM THE S. THAT FRONT PASSES
EARLY WED...FOLLOWED BY A WAVE AND UPPER LEVEL S/W TROF THAT CROSS
WED INTO WEDNESDAY NT. CARRIED CHANCE POPS FOR THIS IN KEEPING WITH
HPC...WHICH FOLLOWS THE ECMWF AND THEN THE ECENS MEAN WHICH BECOMES
A GOOD REPRESENTATION OF THE MODEL AVERAGE LATER IN THE PERIOD.
WEAK SFC HIGH PRESSURE FOR THU ALTHOUGH ANOTHER UPPER LEVEL S/W TROF
ALSO CROSSES.
A STRONGER COLD FRONT DROPS DOWN FRI AS THE EASTERN CONUS LONG WAVE
TROF BEGINS TO SET UP. CARRIED THE CHANCE FOR PRECIPITATION WITH
THIS STRONGER FRONT ALTHOUGH MOISTURE WILL AGAIN BE LIMITED...AGAIN
KEEPING CLOSE TO HPC GUIDANCE.
ADJUSTED TEMPERATURES TO OR TOWARD HPC EARLY ON WHICH ENTAILED
HIGHER VALUES WED AND LOWER VALUES THU AND THU NT. WENT LOWER THAN
HPC BEYOND THAT IN DEFERENCE TO THE MEX AND ISC. AGAIN THOUGH THERE
IS SOME QUESTION AS TO HOW MUCH COLDER IT GETS ONCE THE SECOND FRONT
ROLLS THROUGH.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
930 AM UPDATE...
LOW CIGS TAKING LONGER TO LIFT...LASTING WELL INTO HE AFTERNOON
ACROSS THE S. YET ANOTHER BATCH OF IFR CLOUD HEADING S OUT OF PA
AFFECTING NORTHERN SITES INTO THE AFTERNOON DESPITE EARLIER
EXPECTATIONS OF CLEARING THERE. PKB NEAR EDGE OF THIS DECK.
PREV DISCN...
A LOW PRESSURE SYSTEM MOVING SOUTH OF THE REGION WAS CREATING
IFR/LIFR CONDITIONS. SOME DRIER AIR WILL SLOWLY PUSH SOUTHEASTWARD
ACROSS THE REGION DURING THE DAY...ALLOWING FOR CONDITIONS TO
GRADUALLY CHANGE TO VFR FROM NORTHWEST TO SOUTHEAST TODAY. VFR
CONDITIONS CAN THEN BE EXPECTED THIS EVENING. VALLEY FOG IS EXPECTED
TO FORM LATE SUNDAY NIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF CEILINGS AND VISIBILITIES IMPROVING
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 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY M M M M M L M M H H H H
HTS CONSISTENCY H H M H M M M H H H H H
BKW CONSISTENCY L L L M M H L L H M H H
EKN CONSISTENCY L L L M L H M H H H H H
PKB CONSISTENCY M M M M H H H H H H H H
CKB CONSISTENCY L L H M L L M H H H H H
AFTER 12Z MONDAY...
IFR/LIFR POSSIBLE IN VALLEY FOG MONDAY MORNING...ESPECIALLY IN
MOUNTAINS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...TRM/RPY
SHORT TERM...30
LONG TERM...TRM
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
759 AM EST SUN FEB 5 2012
.SYNOPSIS...
HIGH PRESSURE BUILDS IN TODAY. COLD FRONT PASSES TUESDAY NIGHT
FOLLOWED BY A WEAK WAVE MIDWEEK. ANOTHER COLD FRONT CROSSES FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
730 AM UPDATE...
ADJUSTED POPS TO BETTER HANDLE LAST BAND OF RAIN PUSHING DOWN FROM
THE N...ASSOCIATED WITH FRONT UP AROUND H85 LEVEL. ALSO ADDED
DRIZZLE AND AREAS OF FOG. OTHERWISE FORECAST ON TRACK INCLUDING
CLEARING TREND FROM N TO S ON DRY ADVECTION BEHIND FRONT PUSHING
SAME DIRECTION.
PREV DISCN...
CONSIDERABLE DIFFERENCES BETWEEN THE NAM AND GFS WITH THE HANDLING
OF THE LOW LEVEL MOISTURE TODAY. RUC SUPPORTS THE FASTER CLEARING
FOUND IN THE GFS. THEREFORE WILL LEAN MORE TOWARD THE FASTER
SOLUTION. WITH CALM WINDS TONIGHT AND DECENT RADIATION
CONDITIONS...WILL GO TOWARD THE LOWER END OF THE MOS GUIDANCE. WILL
ALSO INCLUDE VALLEY FOG.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MDLS ARE STARTING TO CONVERGE ON HANDLING OF UPR LOW POISED TO MOVE
THRU ON MON. NAM/SREF CONT TO OPEN THIS UP INTO A WAVE ON
APPROACH...WITH REMAINDER OF GLOBAL MDLS KEEPING A STRONGER INTACT
CLOSED LOW AT H5. WILL FOLLOW HPC PREFERENCE FOR A ECWMF/GFS
BLEND...NOTING NAM TO BE AN OUTLIER ATTM. GIVEN THAT...WILL INCREASE
CLDS ACROSS S BY 18Z...WITH MOISTENING OF THE COLUMN THRU H7. WEAK
LIFT IN THIS LAYER AIDED BY UPR LOW SHOULD ALLOW LIGHT PRECIPITATION
TO BREAK OUT ACROSS SW VA...SOUTHERN COAL FIELDS AND SOUTHERN AND
CENTRAL WV MTNS BY AFTN. GLOBAL MDLS DO INDICATE QPF WITH
THIS...ALBEIT VERY LIGHT. THEREFORE...INTRODUCED CHC POPS ACROSS
AFOREMENTIONED AREAS...MAINLY FOR AFTN AND EARLY EVE. TEMP PROFILES
SUPPORT MAINLY LIQUID...PERHAPS ENDING AS A FEW WET FLAKES ACROSS
THE MTNS EARLY EVE. WILL SEE A SHARP LINE BETWEEN SUN AND CLDS.
THINK AREAS NORTH OF I64 CORRIDOR WILL SEE MAINLY SUNSHINE.
LOOKING AT QUIET WX FOR TUE UNDER SFC HIGH. A S/W TROF MAY BRING A
FEW SHRA/SHSN TO THE AREA WED. IF NOTHING ELSE...WILL INCREASE THE
CLDS.
GUIDANCE VERY SIMILAR TO INHERITED NUMBERS...SO LITTLE CHANGE
NECESSARY. HOWEVER...MAY SEE SOMEWHAT OF A TEMP GRADIENT MON WHERE
SE OH AND NORTHERN WV ENDS UP WARMER THAN SOUTHERN AREAS DUE TO CLDS.
OVERALL LOOKING AT AN ABV NORMAL PERIOD THRU MIDWEEK...NOTHING NEW
THIS WINTER.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
ZONAL FLOW TO START TRANSITIONS TO NW FLOW THIS PERIOD AS LONG WAVE
TROUGH AMPLIFIES IN THE E. THIS LONG WAVE WILL LIKELY BE TRANSIENT
AGAIN THOUGH PER ONGOING LACK OF HIGH LATITUDE BLOCKING...TO WHICH
THE LACK OF DEEP PENETRATION OF ARCTIC AIR DOWN INTO THE EASTERN
CONUS IS ALSO ATTRIBUTABLE.
PERIOD STARTS DRY TUE NT WITH HIGH PRESSURE GIVING WAY TO A MOISTURE
STARVED COLD FRONT WITH NO INFLOW FROM THE S. THAT FRONT PASSES
EARLY WED...FOLLOWED BY A WAVE AND UPPER LEVEL S/W TROF THAT CROSS
WED INTO WEDNESDAY NT. CARRIED CHANCE POPS FOR THIS IN KEEPING WITH
HPC...WHICH FOLLOWS THE ECMWF AND THEN THE ECENS MEAN WHICH BECOMES
A GOOD REPRESENTATION OF THE MODEL AVERAGE LATER IN THE PERIOD.
WEAK SFC HIGH PRESSURE FOR THU ALTHOUGH ANOTHER UPPER LEVEL S/W TROF
ALSO CROSSES.
A STRONGER COLD FRONT DROPS DOWN FRI AS THE EASTERN CONUS LONG WAVE
TROF BEGINS TO SET UP. CARRIED THE CHANCE FOR PRECIPITATION WITH
THIS STRONGER FRONT ALTHOUGH MOISTURE WILL AGAIN BE LIMITED...AGAIN
KEEPING CLOSE TO HPC GUIDANCE.
ADJUSTED TEMPERATURES TO OR TOWARD HPC EARLY ON WHICH ENTAILED
HIGHER VALUES WED AND LOWER VALUES THU AND THU NT. WENT LOWER THAN
HPC BEYOND THAT IN DEFERENCE TO THE MEX AND ISC. AGAIN THOUGH THERE
IS SOME QUESTION AS TO HOW MUCH COLDER IT GETS ONCE THE SECOND FRONT
ROLLS THROUGH.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
A LOW PRESSURE SYSTEM MOVING SOUTH OF THE REGION WAS CREATING
IFR/LIFR CONDITIONS. SOME DRIER AIR WILL SLOWLY PUSH SOUTHEASTWARD
ACROSS THE REGION DURING THE DAY...ALLOWING FOR CONDITIONS TO
GRADUALLY CHANGE TO VFR FROM NORTHWEST TO SOUTHEAST TODAY. VFR
CONDITIONS CAN THEN BE EXPECTED THIS EVENING. VALLEY FOG IS EXPECTED
TO FORM LATE SUNDAY NIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF CEILINGS AND VISIBILITIES IMPROVING
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 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY M M M M M L M M H H H H
HTS CONSISTENCY H H M H M M M H H H H H
BKW CONSISTENCY L L L M M H L L H M H H
EKN CONSISTENCY L L L M L H M H H H H H
PKB CONSISTENCY M M M M H H H H H H H H
CKB CONSISTENCY L L H M L L M H H H H H
AFTER 12Z MONDAY...
IFR/LIFR POSSIBLE IN VALLEY FOG MONDAY MORNING...ESPECIALLY IN
MOUNTAIN VALLEYS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...TRM/RPY
SHORT TERM...30
LONG TERM...TRM
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
536 AM EST SUN FEB 5 2012
.SYNOPSIS...
HIGH PRESSURE BUILDS IN TODAY. COLD FRONT PASSES TUESDAY NIGHT
FOLLOWED BY A WEAK WAVE MIDWEEK. ANOTHER COLD FRONT CROSSES FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CONSIDERABLE DIFFERENCES BETWEEN THE NAM AND GFS WITH THE HANDLING
OF THE LOW LEVEL MOISTURE TODAY. RUC SUPPORTS THE FASTER CLEARING
FOUND IN THE GFS. THEREFORE WILL LEAN MORE TOWARD THE FASTER
SOLUTION. WITH CALM WINDS TONIGHT AND DECENT RADIATION
CONDITIONS...WILL GO TOWARD THE LOWER END OF THE MOS GUIDANCE. WILL
ALSO INCLUDE VALLEY FOG.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MDLS ARE STARTING TO CONVERGE ON HANDLING OF UPR LOW POISED TO MOVE
THRU ON MON. NAM/SREF CONT TO OPEN THIS UP INTO A WAVE ON
APPROACH...WITH REMAINDER OF GLOBAL MDLS KEEPING A STRONGER INTACT
CLOSED LOW AT H5. WILL FOLLOW HPC PREFERENCE FOR A ECWMF/GFS
BLEND...NOTING NAM TO BE AN OUTLIER ATTM. GIVEN THAT...WILL INCREASE
CLDS ACROSS S BY 18Z...WITH MOISTENING OF THE COLUMN THRU H7. WEAK
LIFT IN THIS LAYER AIDED BY UPR LOW SHOULD ALLOW LIGHT PRECIPITATION
TO BREAK OUT ACROSS SW VA...SOUTHERN COAL FIELDS AND SOUTHERN AND
CENTRAL WV MTNS BY AFTN. GLOBAL MDLS DO INDICATE QPF WITH
THIS...ALBEIT VERY LIGHT. THEREFORE...INTRODUCED CHC POPS ACROSS
AFOREMENTIONED AREAS...MAINLY FOR AFTN AND EARLY EVE. TEMP PROFILES
SUPPORT MAINLY LIQUID...PERHAPS ENDING AS A FEW WET FLAKES ACROSS
THE MTNS EARLY EVE. WILL SEE A SHARP LINE BETWEEN SUN AND CLDS.
THINK AREAS NORTH OF I64 CORRIDOR WILL SEE MAINLY SUNSHINE.
LOOKING AT QUIET WX FOR TUE UNDER SFC HIGH. A S/W TROF MAY BRING A
FEW SHRA/SHSN TO THE AREA WED. IF NOTHING ELSE...WILL INCREASE THE
CLDS.
GUIDANCE VERY SIMILAR TO INHERITED NUMBERS...SO LITTLE CHANGE
NECESSARY. HOWEVER...MAY SEE SOMEWHAT OF A TEMP GRADIENT MON WHERE
SE OH AND NORTHERN WV ENDS UP WARMER THAN SOUTHERN AREAS DUE TO CLDS.
OVERALL LOOKING AT AN ABV NORMAL PERIOD THRU MIDWEEK...NOTHING NEW
THIS WINTER.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
ZONAL FLOW TO START TRANSITIONS TO NW FLOW THIS PERIOD AS LONG WAVE
TROUGH AMPLIFIES IN THE E. THIS LONG WAVE WILL LIKELY BE TRANSIENT
AGAIN THOUGH PER ONGOING LACK OF HIGH LATITUDE BLOCKING...TO WHICH
THE LACK OF DEEP PENETRATION OF ARCTIC AIR DOWN INTO THE EASTERN
CONUS IS ALSO ATTRIBUTABLE.
PERIOD STARTS DRY TUE NT WITH HIGH PRESSURE GIVING WAY TO A MOISTURE
STARVED COLD FRONT WITH NO INFLOW FROM THE S. THAT FRONT PASSES
EARLY WED...FOLLOWED BY A WAVE AND UPPER LEVEL S/W TROF THAT CROSS
WED INTO WEDNESDAY NT. CARRIED CHANCE POPS FOR THIS IN KEEPING WITH
HPC...WHICH FOLLOWS THE ECMWF AND THEN THE ECENS MEAN WHICH BECOMES
A GOOD REPRESENTATION OF THE MODEL AVERAGE LATER IN THE PERIOD.
WEAK SFC HIGH PRESSURE FOR THU ALTHOUGH ANOTHER UPPER LEVEL S/W TROF
ALSO CROSSES.
A STRONGER COLD FRONT DROPS DOWN FRI AS THE EASTERN CONUS LONG WAVE
TROF BEGINS TO SET UP. CARRIED THE CHANCE FOR PRECIPITATION WITH
THIS STRONGER FRONT ALTHOUGH MOISTURE WILL AGAIN BE LIMITED...AGAIN
KEEPING CLOSE TO HPC GUIDANCE.
ADJUSTED TEMPERATURES TO OR TOWARD HPC EARLY ON WHICH ENTAILED
HIGHER VALUES WED AND LOWER VALUES THU AND THU NT. WENT LOWER THAN
HPC BEYOND THAT IN DEFERENCE TO THE MEX AND ISC. AGAIN THOUGH THERE
IS SOME QUESTION AS TO HOW MUCH COLDER IT GETS ONCE THE SECOND FRONT
ROLLS THROUGH.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A LOW PRESSURE SYSTEM MOVING SOUTH OF THE REGION WAS CREATING
IFR/LIFR CONDITIONS. SOME DRIER AIR WILL SLOWLY PUSH SOUTHEASTWARD
ACROSS THE REGION DURING THE DAY...ALLOWING FOR CONDITIONS TO
GRADUALLY CHANGE TO VFR FROM NORTHWEST TO SOUTHEAST TODAY. VFR
CONDITIONS CAN THEN BE EXPECTED THIS EVENING. VALLEY FOG IS EXPECTED
TO FORM LATE SUNDAY NIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF CEILINGS AND VISIBILITIES IMPROVING
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 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY M M M M M L M M H H H H
HTS CONSISTENCY H H M H M M M H H H H H
BKW CONSISTENCY L L L M M H L L H M H H
EKN CONSISTENCY L L L M L H M H H H H H
PKB CONSISTENCY M M M M H H H H H H H H
CKB CONSISTENCY L L H M L L M H H H H H
AFTER 12Z MONDAY...
IFR/LIFR POSSIBLE IN VALLEY FOG MONDAY MORNING...ESPECIALLY IN
MOUNTAIN VALLEYS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...RPY
SHORT TERM...30
LONG TERM...TRM
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
245 AM EST SUN FEB 5 2012
.SYNOPSIS...
HIGH PRESSURE BUILDS IN TODAY. COLD FRONT PASSES TUESDAY NIGHT
FOLLOWED BY A WEAK WAVE MIDWEEK. ANOTHER COLD FRONT CROSSES FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CONSIDERABLE DIFFERENCES BETWEEN THE NAM AND GFS WITH THE HANDLING
OF THE LOW LEVEL MOISTURE TODAY. RUC SUPPORTS THE FASTER CLEARING
FOUND IN THE GFS. THEREFORE WILL LEAN MORE TOWARD THE FASTER
SOLUTION. WITH CALM WINDS TONIGHT AND DECENT RADIATION
CONDITIONS...WILL GO TOWARD THE LOWER END OF THE MOS GUIDANCE. WILL
ALSO INCLUDE VALLEY FOG.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
MDLS ARE STARTING TO CONVERGE ON HANDLING OF UPR LOW POISED TO MOVE
THRU ON MON. NAM/SREF CONT TO OPEN THIS UP INTO A WAVE ON
APPROACH...WITH REMAINDER OF GLOBAL MDLS KEEPING A STRONGER INTACT
CLOSED LOW AT H5. WILL FOLLOW HPC PREFERENCE FOR A ECWMF/GFS
BLEND...NOTING NAM TO BE AN OUTLIER ATTM. GIVEN THAT...WILL INCREASE
CLDS ACROSS S BY 18Z...WITH MOISTENING OF THE COLUMN THRU H7. WEAK
LIFT IN THIS LYR AIDED BY UPR LOW SHOULD ALLOW LIGHT PRECIPITATION
TO BREAK OUT ACROSS SW VA...SOUTHERN COAL FIELDS AND SOUTHERN AND
CENTRAL WV MTNS BY AFTN. GLOBAL MDLS DO INDICATE QPF WITH
THIS...ALBEIT VERY LIGHT. THEREFORE...INTRODUCED CHC POPS ACROSS
AFOREMENTIONED AREAS...MAINLY FOR AFTN AND EARLY EVE. TEMP PROFILES
SUPPORT MAINLY LIQUID...PERHAPS ENDING AS A FEW WET FLAKES ACROSS
THE MTNS EARLY EVE. WILL SEE A SHARP LINE BETWEEN SUN AND CLDS.
THINK AREAS NORTH OF I64 CORRIDOR WILL SEE MAINLY SUNSHINE.
LOOKING AT QUIET WX FOR TUE UNDER SFC HIGH. A S/W TROF MAY BRING A
FEW SHRA/SHSN TO THE AREA WED. IF NOTHING ELSE...WILL INCREASE THE
CLDS.
GUIDANCE VERY SIMILAR TO INHERITED NUMBERS...SO LITTLE CHANGE
NECESSARY. HOWEVER...MAY SEE SOMEWHAT OF A TEMP GRADIENT MON WHERE
SE OH AND NORTHERN WV ENDS UP WARMER THAN SOUTHERN AREAS DUE TO CLDS.
OVERALL LOOKING AT AN ABV NORMAL PERIOD THRU MIDWEEK...NOTHING NEW
THIS WINTER.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
ZONAL FLOW TO START TRANSITIONS TO NW FLOW THIS PERIOD AS LONG WAVE
TROUGH AMPLIFIES IN THE E. THIS LONG WAVE WILL LIKELY BE TRANSIENT
AGAIN THOUGH PER ONGOING LACK OF HIGH LATITUDE BLOCKING...TO WHICH
THE LACK OF DEEP PENETRATION OF ARCTIC AIR DOWN INTO THE EASTERN
CONUS IS ALSO ATTRIBUTABLE.
PERIOD STARTS DRY TUE NT WITH HIGH PRESSURE GIVING WAY TO A MOISTURE
STARVED COLD FRONT WITH NO INFLOW FROM THE S. THAT FRONT PASSES
EARLY WED...FOLLOWED BY A WAVE AND UPPER LEVEL S/W TROF THAT CROSS
WED INTO WEDNESDAY NT. CARRIED CHANCE POPS FOR THIS IN KEEPING WITH
HPC...WHICH FOLLOWS THE ECMWF AND THEN THE ECENS MEAN WHICH BECOMES
A GOOD REPRESENTATION OF THE MODEL AVERAGE LATER IN THE PERIOD.
WEAK SFC HIGH PRESSURE FOR THU ALTHOUGH ANOTHER UPPER LEVEL S/W TROF
ALSO CROSSES.
A STRONGER COLD FRONT DROPS DOWN FRI AS THE EASTERN CONUS LONG WAVE
TROF BEGINS TO SET UP. CARRIED THE CHANCE FOR PRECIPITATION WITH
THIS STRONGER FRONT ALTHOUGH MOISTURE WILL AGAIN BE LIMITED...AGAIN
KEEPING CLOSE TO HPC GUIDANCE.
ADJUSTED TEMPERATURES TO OR TOWARD HPC EARLY ON WHICH ENTAILED
HIGHER VALUES WED AND LOWER VALUES THU AND THU NT. WENT LOWER THAN
HPC BEYOND THAT IN DEFERENCE TO THE MEX AND ISC. AGAIN THOUGH THERE
IS SOME QUESTION AS TO HOW MUCH COLDER IT GETS ONCE THE SECOND FRONT
ROLLS THROUGH.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
A LOW PRESSURE SYSTEM MOVING SOUTH OF THE REGION WAS CREATING
IFR/LIFR CONDITIONS. SOME DRIER AIR MOVING SOUTHWARD FROM EASTERN
OHIO WILL CAUSE SOME IMPROVING CONDITIONS IN THE SOUTHEAST OHIO AND
NORTHWESTERN WEST VIRGINIA...OTHERWISE...EXPECT THE IFR/LIFR
CONDITIONS TO CONTINUE THROUGH DAY BREAK. THE DRIER AIR WILL SLOWLY
PUSH SOUTHEASTWARD ACROSS THE REGION DURING THE DAY...ALLOWING FOR
CONDITIONS TO GRADUALLY CHANGE TO VFR FROM NORTHWEST TO SOUTHEAST
TODAY. VFR CONDITIONS CAN THEN BE EXPECTED THIS EVENING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF CEILINGS AND VISIBILITIES IMPROVING
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.
DATE SUN 02/05/12
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY M M M M M M M M M L L H
HTS CONSISTENCY M M M M M M M L L L L M
BKW CONSISTENCY L L M M M M M L L L L M
EKN CONSISTENCY L L L L L L L L L M M L
PKB CONSISTENCY M M M M M M L H H H H H
CKB CONSISTENCY H H H H H L L L M M H H
AFTER 06Z MONDAY...
IFR/LIFR POSSIBLE IN VALLEY FOG MONDAY MORNING...ESPECIALLY IN
MOUNTAIN VALLEYS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...RPY
SHORT TERM...30
LONG TERM...TRM
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1016 AM EST SUN FEB 5 2012
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER THE GREAT LAKES WILL BUILD SOUTHEAST
ACROSS PENNSYLVANIA OVER THE NEXT COUPLE OF DAYS. A SERIES OF
SHORTWAVES WILL CARVE OUT A DEEPENING TROUGH ACROSS THE EASTERN
CONUS BY THE END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID CLOUD SHIELD ASSOCIATED WITH DEPARTING WAVE CONTINUING TO EXIT
THE SOUTH CENTRAL MOUNTAINS AND LOWER SUSQ RIVER VALLEY...AND
SHOULD MOVE OUT IN TIME TO BRING A CRISP AND SUNNY AFTERNOON. LOW
CLOUDS STREAMING SOUTH-SOUTHEASTWARD FROM THE EASTERN GLAKS HAVE
REACHED THE NORTHERN TIER BUT ARE BEING ENTRAINED BY DRY AIR AND
DISSIPATE IN THE DOWNSLOPING NORTHERLY FLOW FROM THE N CENTRAL
MOUNTAINS. SO WHILE SOME INCREASE IN LLVL CLOUDINESS WILL CONTINUE
TO TAKE PLACE...DO NOT THINK WIDESPREAD CIGS WILL ARRIVE IN
CENTRAL OR SOUTH CENTRAL MOUNTAIN LOCATIONS THIS AFTERNOON.
EARLIER LOW LEVEL MOISTURE ACROSS THE SOUTH IS ALSO SLOWLY
DISSIPATING. RUC AND HRRR TIMING WAS A LITTLE LATE...BUT OVERALL
CORRECT IN ITS DISSIPATION.
ENS MEAN 850MB TEMPS ARND -6C LIKELY SUPPORTING HIGH TEMPS FROM
THE U30S ALLEGHENIES...TO THE M40S SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
RIDGE OF HIGH PRESSURE WILL BUILD SOUTH ACROSS PA TONIGHT...SUPPLYING
MCLEAR SKIES AND LIGHT WINDS. SWRLY FLOW AHEAD OF AN APPROACHING
COLD FRONT WILL DRAW A SURGE OF VERY MILD AIR INTO THE REGION
MONDAY. UNDER SUNNY SKIES...TEMPS SHOULD REACH 45-50F OVER MOST OF
CENTRAL PA. BUKKIT SOUNDINGS INDICATE SWRLY WIND GUSTS ARND
20KTS BY AFTN...ESP ACROSS THE NW MTNS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ALL MDL DATA INDICATING A WEAK COLD FRONT WILL SAG SOUTH ACROSS PA
ON TUESDAY...POSSIBLY ACCOMPANIED BY A FEW -SHSN OVR THE N MTNS.
PATTERN FOR LATE WEEK CONTINUES TO LOOK DRY BUT PROGRESSIVELY
COOLER...AS SHORTWAVES CARVE OUT A DEEPENING TROUGH OVR THE
EASTERN CONUS. MDL CONSENSUS TRACKS FIRST SHORTWAVE THRU PA LATE
WED/EARLY THURS...POSSIBLY ACCOMPANIED BY SCT -SHSN. FCST
UNCERTAINTY RAMPS UP BY FRI/SAT...AS MDL SPREAD INCREASES WITH
RESPECT TO STRENGTH/TIMING OF NEXT SHORTWAVE. A BLEND OF GEFS AND
EC ENSEMBLES POINTS TOWARD A MAINLY DRY COLD FRONT PASSAGE ARND
FRIDAY...FOLLOWED BY A SEASONABLY COLD/DRY WEEKEND. THE STRONGER/SLOWER
00Z GFS SOLUTION...WITH POSSIBLE E COAST CYCLOGENESIS...APPEARS
AN UNLIKELY OUTLIER ATTM.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
LINGERING LIGHT RADAR RETURNS AT MID-LEVELS OVER SOUTHERN TIER
WILL CONTINUE TO DIMINISH BY MID MORNING AS DRY NORTHEASTERLY FLOW
FILTERS IN AT LOWER LEVELS - THE BEGINNING OF A RIDGE OF HIGH
PRESSURE BUILDING IN THAT WILL SETTLE ACROSS PA FOR THE NEXT
COUPLE OF DAYS.
AT 12Z...MVFR CONDITIONS AT KBFD IN LOWERING SUBSIDENCE INVERSION.
EXPECT A FAIRLY QUICK RETURN TO VFR CIGS BY MID-LATE MORNING.
KJST-KAOO ALSO EXPERIENCING MVFR-IFR CONDITIONS EARLY THIS MORNING
AS DRIER AIR HAS NOT HAD TIME TO WORK INTO THERE JUST YET. THERE
WILL LIKELY BE A SEVERAL HOUR PERIOD OF MVFR CONDITIONS THERE
BEFORE VFR CONDITIONS RETURN AROUND 16Z. ELSEWHERE...SOME PATCHY
MVFR FOG POSS THROUGH 14Z ACROSS THE SE.
BY AFTERNOON...VFR WILL BE THE RULE AS RIDGE STARTS TO DOMINATE.
EXPECT LIGHT WINDS AND PRISTINE FLYING CONDITIONS THROUGH AT
LEAST MONDAY NIGHT.
OUTLOOK...
MON...NO SIG WX EXPECTED.
TUE...MVFR POSS NW HALF. VFR SE.
WED...MVFR POSS WITH SHSN.
THU...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
742 AM EST SUN FEB 5 2012
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER THE GREAT LAKES WILL BUILD SOUTHEAST
ACROSS PENNSYLVANIA OVER THE NEXT COUPLE OF DAYS. A SERIES OF
SHORTWAVES WILL CARVE OUT A DEEPENING TROUGH ACROSS THE EASTERN
CONUS BY THE END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WAVE OF LOW PRESSURE PASSING SOUTH OF PA CONTINUES TO PRODUCE
LIGHT RETURNS ON RADAR ACROSS THE S TIER. HOWEVER...SFC OBS
SUGGEST MOST OF THIS IS VIRGA...THE RESULT OF DRY NERLY FLOW AT
THE SFC. WILL CARRY A LOW CHC OF -SHSN ACROSS THE S TIER COUNTIES
UNTIL ABOUT 13Z.
PLENTY OF LOW LVL MOISTURE...COMBINED WITH CALM WIND...HAS ALLOWED
AREAS OF FOG TO FORM OVER SOUTHERN PA. RUC AND HRRR SFC RH SUGGEST
FOG ACROSS THE SC MTNS WILL DISSIPATE BY ARND 14Z. MUCH DRIER AIR
MASS ACROSS THE LOWER GRT LKS WILL OVERSPREAD THE REGION LATER
TODAY...BRINGING CLEARING SKIES. AIR MASS WILL REMAIN RELATIVELY
MILD FOR EARLY FEB WITH ENS MEAN 850MB TEMPS ARND -6C LIKELY
SUPPORTING HIGH TEMPS FROM THE U30S ALLEGHENIES...TO THE M40S SUSQ
VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
RIDGE OF HIGH PRESSURE WILL BUILD SOUTH ACROSS PA TONIGHT...SUPPLYING
MCLEAR SKIES AND LIGHT WINDS. SWRLY FLOW AHEAD OF AN APPROACHING
COLD FRONT WILL DRAW A SURGE OF VERY MILD AIR INTO THE REGION
MONDAY. UNDER SUNNY SKIES...TEMPS SHOULD REACH 45-50F OVER MOST OF
CENTRAL PA. BUKKIT SOUNDINGS INDICATE SWRLY WIND GUSTS ARND
20KTS BY AFTN...ESP ACROSS THE NW MTNS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ALL MDL DATA INDICATING A WEAK COLD FRONT WILL SAG SOUTH ACROSS PA
ON TUESDAY...POSSIBLY ACCOMPANIED BY A FEW -SHSN OVR THE N MTNS.
PATTERN FOR LATE WEEK CONTINUES TO LOOK DRY BUT PROGRESSIVELY
COOLER...AS SHORTWAVES CARVE OUT A DEEPENING TROUGH OVR THE
EASTERN CONUS. MDL CONSENSUS TRACKS FIRST SHORTWAVE THRU PA LATE
WED/EARLY THURS...POSSIBLY ACCOMPANIED BY SCT -SHSN. FCST
UNCERTAINTY RAMPS UP BY FRI/SAT...AS MDL SPREAD INCREASES WITH
RESPECT TO STRENGTH/TIMING OF NEXT SHORTWAVE. A BLEND OF GEFS AND
EC ENSEMBLES POINTS TOWARD A MAINLY DRY COLD FRONT PASSAGE ARND
FRIDAY...FOLLOWED BY A SEASONABLY COLD/DRY WEEKEND. THE STRONGER/SLOWER
00Z GFS SOLUTION...WITH POSSIBLE E COAST CYCLOGENESIS...APPEARS
AN UNLIKELY OUTLIER ATTM.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
LINGERING LIGHT RADAR RETURNS AT MID-LEVELS OVER SOUTHERN TIER
WILL CONTINUE TO DIMINISH BY MID MORNING AS DRY NORTHEASTERLY FLOW
FILTERS IN AT LOWER LEVELS - THE BEGINNING OF A RIDGE OF HIGH
PRESSURE BUILDING IN THAT WILL SETTLE ACROSS PA FOR THE NEXT
COUPLE OF DAYS.
AT 12Z...MVFR CONDITIONS AT KBFD IN LOWERING SUBSIDENCE INVERSION.
EXPECT A FAIRLY QUICK RETURN TO VFR CIGS BY MID-LATE MORNING.
KJST-KAOO ALSO EXPERIENCING MVFR-IFR CONDITIONS EARLY THIS MORNING
AS DRIER AIR HAS NOT HAD TIME TO WORK INTO THERE JUST YET. THERE
WILL LIKELY BE A SEVERAL HOUR PERIOD OF MVFR CONDITIONS THERE
BEFORE VFR CONDITIONS RETURN AROUND 16Z. ELSEWHERE...SOME PATCHY
MVFR FOG POSS THROUGH 14Z ACROSS THE SE.
BY AFTERNOON...VFR WILL BE THE RULE AS RIDGE STARTS TO DOMINATE.
EXPECT LIGHT WINDS AND PRISTINE FLYING CONDITIONS THROUGH AT
LEAST MONDAY NIGHT.
OUTLOOK...
MON...NO SIG WX EXPECTED.
TUE...MVFR POSS NW HALF. VFR SE.
WED...MVFR POSS WITH SHSN.
THU...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
629 AM EST SUN FEB 5 2012
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER THE GREAT LAKES WILL BUILD SOUTHEAST
ACROSS PENNSYLVANIA OVER THE NEXT COUPLE OF DAYS. A SERIES OF
SHORTWAVES WILL CARVE OUT A DEEPENING TROUGH ACROSS THE EASTERN
CONUS BY THE END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WAVE OF LOW PRESSURE PASSING SOUTH OF PA CONTINUES TO PRODUCE
LIGHT RETURNS ON RADAR ACROSS THE S TIER. HOWEVER...SFC OBS
SUGGEST MOST OF THIS IS VIRGA...THE RESULT OF DRY NERLY FLOW AT
THE SFC. WILL CARRY A LOW CHC OF -SHSN ACROSS THE S TIER COUNTIES
UNTIL ABOUT 13Z.
PLENTY OF LOW LVL MOISTURE...COMBINED WITH CALM WIND...HAS ALLOWED
AREAS OF FOG TO FORM OVER SOUTHERN PA. RUC AND HRRR SFC RH SUGGEST
FOG ACROSS THE SC MTNS WILL DISSIPATE BY ARND 14Z. MUCH DRIER AIR
MASS ACROSS THE LOWER GRT LKS WILL OVERSPREAD THE REGION LATER
TODAY...BRINGING CLEARING SKIES. AIR MASS WILL REMAIN RELATIVELY
MILD FOR EARLY FEB WITH ENS MEAN 850MB TEMPS ARND -6C LIKELY
SUPPORTING HIGH TEMPS FROM THE U30S ALLEGHENIES...TO THE M40S SUSQ
VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
RIDGE OF HIGH PRESSURE WILL BUILD SOUTH ACROSS PA TONIGHT...SUPPLYING
MCLEAR SKIES AND LIGHT WINDS. SWRLY FLOW AHEAD OF AN APPROACHING
COLD FRONT WILL DRAW A SURGE OF VERY MILD AIR INTO THE REGION
MONDAY. UNDER SUNNY SKIES...TEMPS SHOULD REACH 45-50F OVER MOST OF
CENTRAL PA. BUKKIT SOUNDINGS INDICATE SWRLY WIND GUSTS ARND
20KTS BY AFTN...ESP ACROSS THE NW MTNS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ALL MDL DATA INDICATING A WEAK COLD FRONT WILL SAG SOUTH ACROSS PA
ON TUESDAY...POSSIBLY ACCOMPANIED BY A FEW -SHSN OVR THE N MTNS.
PATTERN FOR LATE WEEK CONTINUES TO LOOK DRY BUT PROGRESSIVELY
COOLER...AS SHORTWAVES CARVE OUT A DEEPENING TROUGH OVR THE
EASTERN CONUS. MDL CONSENSUS TRACKS FIRST SHORTWAVE THRU PA LATE
WED/EARLY THURS...POSSIBLY ACCOMPANIED BY SCT -SHSN. FCST
UNCERTAINTY RAMPS UP BY FRI/SAT...AS MDL SPREAD INCREASES WITH
RESPECT TO STRENGTH/TIMING OF NEXT SHORTWAVE. A BLEND OF GEFS AND
EC ENSEMBLES POINTS TOWARD A MAINLY DRY COLD FRONT PASSAGE ARND
FRIDAY...FOLLOWED BY A SEASONABLY COLD/DRY WEEKEND. THE STRONGER/SLOWER
00Z GFS SOLUTION...WITH POSSIBLE E COAST CYCLOGENESIS...APPEARS
AN UNLIKELY OUTLIER ATTM.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
BANDS OF LOW STRATOCU AND SNOW EMMINATING FROM LOW PRESSURE
TRACKING SOUTH OF PENNSYLVANIA WILL BRING LIFR TO VLIFR VSBYS AND
CIGS TO JST AND AOO THROUGH EARLY SUNDAY. AS THE LOW MOVES OFF TO
THE EAST DRYING WILL ARRIVE FROM NORTH TO SOUTH EARLY SUNDAY AS
HIGH PRESSURE BUILDS INTO THE REGION. VFR CONDS WILL RETURN WITH
FAIR WEATHER EXPECTED THROUGHOUT SUNDAY.
OUTLOOK...
MON...NO SIG WX EXPECTED.
TUE...MVFR POSS NW HALF. VFR SE.
WED...MVFR POSS. THU...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...DANGELO/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
537 AM EST SUN FEB 5 2012
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE OVER THE GREAT LAKES WILL BUILD SOUTHEAST
ACROSS PENNSYLVANIA OVER THE NEXT COUPLE OF DAYS. A SERIES OF
SHORTWAVES WILL CARVE OUT A DEEPENING TROUGH ACROSS THE EASTERN
CONUS BY THE END OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WAVE OF LOW PRESSURE PASSING SOUTH OF PA CONTINUES TO PRODUCE
LIGHT RETURNS ON RADAR ACROSS THE S TIER. HOWEVER...SFC OBS
SUGGEST MOST OF THIS IS VIRGA...THE RESULT OF DRY NERLY FLOW AT
THE SFC. WILL CARRY A LOW CHC OF -SHSN ACROSS THE S TIER COUNTIES
UNTIL ABOUT 13Z.
PLENTY OF LOW LVL MOISTURE...COMBINED WITH CALM WIND...HAS ALLOWED
AREAS OF FOG TO FORM OVER SOUTHERN PA. RUC AND HRRR SFC RH SUGGEST
FOG ACROSS THE SC MTNS WILL DISSIPATE BY ARND 14Z. MUCH DRIER AIR
MASS...POISED ACROSS THE LOWER GRT LKS...WILL OVERSPREAD THE
REGION LATER TODAY...BRINGING CLEARING SKIES. AIR MASS WILL REMAIN
RELATIVELY MILD FOR EARLY FEB WITH ENS MEAN 850MB TEMPS ARND -6C
LIKELY SUPPORTING HIGH TEMPS FROM THE U30S ALLEGHENIES...TO THE
M40S SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
RIDGE OF HIGH PRESSURE WILL BUILD SOUTH ACROSS PA TONIGHT...SUPPLYING
MCLEAR SKIES AND LIGHT WINDS. SWRLY FLOW AHEAD OF AN APPROACHING
COLD FRONT WILL DRAW A SURGE OF VERY MILD AIR INTO THE REGION
MONDAY. UNDER SUNNY SKIES...TEMPS SHOULD REACH 45-50F OVER MOST OF
CENTRAL PA. BUKKIT SOUNDINGS INDICATE SWRLY WIND GUSTS ARND
20KTS BY AFTN...ESP ACROSS THE NW MTNS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ALL MDL DATA INDICATING A WEAK COLD FRONT WILL SAG SOUTH ACROSS PA
ON TUESDAY...POSSIBLY ACCOMPANIED BY A FEW -SHSN OVR THE N MTNS.
PATTERN FOR LATE WEEK CONTINUES TO LOOK DRY BUT PROGRESSIVELY
COOLER...AS SHORTWAVES CARVE OUT A DEEPENING TROUGH OVR THE
EASTERN CONUS. MDL CONSENSUS TRACKS FIRST SHORTWAVE THRU PA LATE
WED/EARLY THURS...POSSIBLY ACCOMPANIED BY SCT -SHSN. FCST
UNCERTAINTY RAMPS UP BY FRI/SAT...AS MDL SPREAD INCREASES WITH
RESPECT TO STRENGTH/TIMING OF NEXT SHORTWAVE. A BLEND OF GEFS AND
EC ENSEMBLES POINTS TOWARD A MAINLY DRY COLD FRONT PASSAGE ARND
FRIDAY...FOLLOWED BY A SEASONABLY COLD/DRY WEEKEND. THE STRONGER/SLOWER
00Z GFS SOLUTION...WITH POSSIBLE E COAST CYCLOGENESIS...APPEARS
AN UNLIKELY OUTLIER ATTM.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
BANDS OF LOW STRATOCU AND SNOW EMMINATING FROM LOW PRESSURE
TRACKING SOUTH OF PENNSYLVANIA WILL BRING LIFR TO VLIFR VSBYS AND
CIGS TO JST AND AOO THROUGH EARLY SUNDAY. AS THE LOW MOVES OFF TO
THE EAST DRYING WILL ARRIVE FROM NORTH TO SOUTH EARLY SUNDAY AS
HIGH PRESSURE BUILDS INTO THE REGION. VFR CONDS WILL RETURN WITH
FAIR WEATHER EXPECTED THROUGHOUT SUNDAY.
OUTLOOK...
MON...NO SIG WX EXPECTED.
TUE...MVFR POSS NW HALF. VFR SE.
WED...MVFR POSS. THU...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/MARTIN
AVIATION...DANGELO/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
124 AM EST SUN FEB 5 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK SOUTH OF PENNSYLVANIA THROUGH THE MORNING.
HIGH PRESSURE WILL BE ACCOMPANIED BY MAINLY DRY AND MILD WEATHER
FOR MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
SECOND SHORTWAVE HAS LESS MOISTURE TO WORK WITH THAN PREVIOUS WAVE
ON SATURDAY DID. MUCH OF THE RADAR RETURNS OVER SOUTHERN PA SEEM
TO BE ALOFT AT THIS POINT...BUT ARE ONCE AGAIN TRYING TO MOISTEN
UP THE LOW/MID LEVELS. THE DRYING NERLY FLOW AT THE SFC WILL MAKE
IT TOUGH FOR ANYWHERE BUT THE HIGHEST TERRAIN OF SOMERSET/BEDFORD
CO TO PICK UP ANOTHER HALF INCH OF SNOW. WILL KEEP LIKELY POPS IN JUST
SOMERSET-BEDFORD-FULTON. RADAR TRENDS SUGGEST NR ZERO CHC OF
ADDITIONAL MEASURABLE SNOW NORTH OF THE TURNPIKE. TEMPS ON TRACK
TO DIP TO THE LOWER 20S IN THE NORTH...TO NR 30F OVR THE LOWER
SUSQ VALLEY.
PLENTY OF LOW LVL MOISTURE...COMBINED WITH CALM WIND...HAS ALLOWED
AREAS OF FOG TO FORM OVER SOUTHERN PA...WHICH WILL LIKELY PERSIST
UNTIL ARND DAWN. MCLEAR SKIES WILL ALSO LIKELY RESULT IN PATCHY
RAD FOG ACROSS THE N MTNS TOWARDS DAWN. HRRR SHOWS SFC RH/S
DROPPING TO NR 100PCT UP THERE BY 12Z.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM MONDAY/...
HIGH PRESSURE WILL BUILD IN FROM THE WESTERN GREAT LAKES AND OHIO
VALLEY...WITH THE RIDGE AXIS ARRIVING ACROSS CENTRAL PA IN THE
AFTERNOON HOURS. ANY SHSN IN THE SRN MTS WILL DISSIPATE AND SKIES
WILL EVEN GET BRIGHTER THERE LATER IN THE DAY AFTER THE FLOW
BECOMES MORE NORTHWEST THAN NORTHEAST. A VERY PLEASANT AFTERNOON
IS EXPECTED WITH MAX TEMPS RANGING FROM THE UPPER 30S IN THE
NORTHWEST TO THE MID 40S OVER THE SOUTHEAST.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
NOT A LOT OF CHANGE THIS PACKAGE.
LEFT MENTION OF SNOW IN FAR NORTHERN PA FOR TUE...AS NEXT FRONT
DROPS SOUTHWARD.
TOOK OUT MENTION OF SNOW TUE NIGHT...AS SUPPORT FOR SNOW ALONG
FRONT WEAKENS.
DID TAKE OUT SNOW FOR WED FOR MOST OF THE AREA...BUT WENT
WITH CHC ALONG MD BORDER...AS MODELS HINT AT WAVE ON FRONT IN
SOUTHERN BRANCH...GIVEN SPLIT FLOW. SIMILAR SITUATION TO THE
CURRENT EVENT ACROSS SOUTH CENTRAL PA.
WENT WITH CHC POPS LATE THU INTO FRIDAY...AS AN UPPER LVL
TROUGH MOVES ACROSS THE AREA. AS WINDS GO MORE TO THE NW TO N
ON FRIDAY...LESS CHC OF SNOW SHOWERS AS THE DAY GOES ON.
VERY COLD AIR BUILDS INTO EASTERN CANADA LATE NEXT WEEK...
MODELS HINT THAT THE REAL COLD AIR STAYS NORTH OF PA...THUS
LEFT NEXT WEEKEND DRY AT THIS POINT...GIVEN LOCATON OF BEST
COLD AIR TO LIFT WARM AIR BACK NORTHWARD ALSO MODELS HINT THAT
ANY FRONTAL SNOW WOULD BE NORTH ANYWAY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
BANDS OF LOW STRATOCU AND SNOW EMMINATING FROM LOW PRESSURE
TRACKING SOUTH OF PENNSYLVANIA WILL BRING LIFR TO VLIFR VSBYS AND
CIGS TO JST AND AOO THROUGH EARLY SUNDAY. AS THE LOW MOVES OFF TO
THE EAST DRYING WILL ARRIVE FROM NORTH TO SOUTH EARLY SUNDAY AS
HIGH PRESSURE BUILDS INTO THE REGION. VFR CONDS WILL RETURN WITH
FAIR WEATHER EXPECTED THROUGHOUT SUNDAY.
OUTLOOK...
MON...NO SIG WX EXPECTED.
TUE...MVFR POSS NW HALF. VFR SE.
WED...MVFR POSS. THU...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO/FITZGERALD
SHORT TERM...DANGELO/DEVOIR
LONG TERM...MARTIN
AVIATION...DANGELO/CERU
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
300 PM CST SUN FEB 5 2012
.DISCUSSION.../ISSUED AT 300 PM CST/
AGAIN STRATUS WITH SOME LIGHT FOG HAD BEEN STUBBORN ABOUT ERODING.
TODAY THE PROBLEM AREA IS EASIER TO DIAGNOSE DOWN IN NORTHWEST IOWA
AWAY FROM THE BEST MIXING AND CLOSEST TO THE SNOW COVER. SHORT TERM
MODELS KEEP THIS IN AND THIS LOOKS REASONABLE WITH THE FINE DETAILS
BEING THE TRICKY PART. WILL KEEP IN ALL NIGHT THIS AREA ALONG WITH
SOME AREAS OF FOG...AND EXPAND THE FOG MENTION BEYOND THE STRATUS
LATE TONIGHT IN THE EAST. AT THIS TIME AM NOT ANTICIPATING DENSE
FOG. THERE IS SOME QUESTION ABOUT REDEVELOPMENT FURTHER NORTHWEST
TOWARD DE SMET WHERE THE LAST OF THE STRATUS NORTH OF I90 IS
STUBBORNLY SHRINKING. WILL KEEP THE REDEVELOPMENT OUT FOR NOW.
ANOTHER AREA MIGHT BE SOUTHERN PART OF SOUTHWEST MN WHICH HAS ALSO
BEEN THE LATEST TO LOSE THE LOW CLOUDS...AND WHERE THE HRRR TRIES TO
BRING IT BACK IN SOME. WESTERN AREAS SHOULD STAY PRETTY CLEAR. LOW
TEMPERATURES SHOULD BE INT HE 20S. LIGHT WEST TO SOUTH WINDS SHOULD
RULE WEST AND NORTH...WITH LIGHT TO CALM SURFACE WINDS SOUTHEAST.
/ WILLIAMS
LINGERING STRATUS/FOG IN THE SOUTHEAST SHOULD CLEAR BY MID-LATE
MORNING AS LIGHT WINDS BECOME WESTERLY AHEAD OF THE COLD FRONT.
FRONTAL TIMING SIMILAR TO EARLIER SHIFT...ENTERING NORTHERN CWA LATE
MORNING...AND EXITING THE SOUTHEAST JUST AFTER SUNSET. SHOULD SEE
DECENT MIXING AHEAD OF AND IMMEDIATELY BEHIND THE FRONT...HELPING
MOST AREAS CLIMB INTO THE 40S WITH WARMEST READINGS ALONG AND SOUTH
OF I-90.
CLOUDS INCREASE BEHIND THE FRONT MONDAY NIGHT...WITH BAND OF STRATUS
POSSIBLE BEHIND THE FRONT DROPPING IN FROM THE NORTH...AND MID CLOUD
DECK EXPANDING ACROSS THE AREA FROM THE SOUTHWEST. THESE TWO LAYERS
OF MOISTURE NEVER REALLY SEEM TO CO-EXIST IN ANY ONE AREA UNTIL LATE
MONDAY NIGHT/EARLY TUESDAY OVER FAR SOUTHERN PARTS OF THE CWA...AND
WILL LIMIT MENTION OF A FEW FLURRIES TO THESE AREAS 06Z-18Z. NAM IS
PRODUCING SOME LIGHT QPF FARTHER NORTH MONDAY NIGHT...BUT SOUNDINGS
WOULD ONLY SUPPORT FREEZING DRIZZLE WITH TEMPERATURES IN THE CLOUD
LAYER NOT COLD ENOUGH TO INTRODUCE ICE INTO THE LAYER. NOT EVEN
HIGHLY CONFIDENT THAT THE BAND OF HIGHER RH INDICATED BY THE MODELS
WILL BE A BONAFIDE STRATUS BAND AND IS NOT JUST AN ARTIFACT OF THE
STRONG COLD ADVECTION...SO WILL LEAVE FORECAST DRY NORTH OF HIGHWAY
18.
LIMITED DIURNAL RANGE MONDAY NIGHT/TUESDAY WITH THE COLD ADVECTION
AND 925MB TEMPS FROM -8C TO -13C TUESDAY AFTERNOON...BUT COLD SNAP
WILL BE SHORT-LIVED AS WITH WEST-SOUTHWEST FLOW AND MOSTLY SUNNY
SKIES AIDING MIXING ON WEDNESDAY...SO WILL STICK WITH TEMPERATURES
MIXED A LITTLE HIGHER THAN 925MB...YIELDING HIGHS IN THE LOWER TO
MID 30S.
ARCTIC COLD FRONT PUSHES THROUGH THE REGION THURSDAY AS POLAR VORTEX
SETS UP CAMP OVER HUDSON BAY...AND MODELS STILL HAVING A TOUGH TIME
AGREEING ON WESTWARD EXTENT AND DURATION OF THE COLDEST AIR INTO THE
NORTHERN PLAINS. 00Z DETERMINISTIC RUNS FEATURED GFS ON COLD END OF
THE SPECTRUM /850MB TEMPS FRIDAY AFTN -16C TO -23C WEST TO EAST/...
WHILE ECMWF WAS QUITE A BIT WARMER /-3C TO -8C FOR SAME TIME FRAME/.
DIFFERENCES PERSISTED INTO SATURDAY...WHEN AFTERNOON 850MB TEMPS
RANGED FROM -10C TO -18C ON THE GFS...TO +10C TO +6C WEST TO EAST ON
THE ECMWF. 12Z DETERMINISTIC RUNS ESSENTIALLY FLIP-FLOPPED...THOUGH
WITH GENERAL TREND TOWARD THE MIDDLE WITH GFS TRENDING WARMER AND
ECMWF TRENDING COLDER THAN THEIR RESPECTIVE PREVIOUS RUNS. ALL THIS
LEADS TO VERY LOW CONFIDENCE IN TEMPERATURE FORECAST FOR THURSDAY
NIGHT THROUGH SATURDAY NIGHT AND WILL STICK FAIRLY CLOSE TO MIDDLE
GROUND WITH MODEL CONSENSUS FOR NOW. WHAT IS A LITTLE MORE CLEAR IS
THAT FRIDAY SHOULD BE THE COLDEST DAY OF THE LONG RANGE PERIOD...
WITH SUBTLE WARMUP FOR SATURDAY...AND GREATER WARMUP MORE LIKELY FOR
NEXT SUNDAY. ALSO FAIRLY CONFIDENT IN CONTINUED DRY FORECAST AS
MOISTURE QUITE LIMITED THROUGHOUT THE LATE WEEK/WEEKEND PERIOD OVER
OUR AREA.
&&
.AVIATION.../FOR THE 18Z TAF ISSUANCE/UPDATED
STRATUS AND SOME FOG WILL CONTINUE OVER NORTHWEST IOWA INCLUDING
SUX. IN THIS AREA IFR CEILINGS AND AREAS OF LIGHT FOG WILL LIKELY
LOWER AGAIN TO LIFR CEILINGS AND VSBYS BELOW 3SM DURING THE NIGHT.
TO THE NORTH...SOME AREAS OF FOG MAINLY 3-5SM POSSIBLE EAST OF THE
JAMES RIVER AFTER 06/06Z. VFR WEST OF THE JAMES RIVER. AFTER 06/14Z
CONDITIONS SHOULD IMPROVE TO VFR EVEN IN NORTHWEST IA DUE TO
INCREASING MIXING AHEAD OF APPROACHING COLD FRONT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NWS SIOUX FALLS SD
1035 PM CST SAT FEB 4 2012
.DISCUSSION.../ISSUED AT 830 PM CST/
UPDATED GRIDS TO REFLECT CURRENT TRENDS OF STRATUS DECK MOVING
SOUTHWARD OVER CWA...AS WELL AS FOG FORMING EARLIER THAN FORECAST.
LIGHT NORTHERLY FLOW AIDING IN ITS MOVEMENT SO NO REASON WHY IT
WON`T CONTINUE TO MOVE SOUTH. RUC MODEL ALSO BACKS CURRENT TREND.
MOVED CLOUD DECK AS FAR SOUTH AS KSUX AND THEN SLOWLY DISSIPATING
DECK POST SUNRISE ON SUNDAY. AS RESULT...I ALSO ADJUSTED A FEW LOW
TEMPERATURE FORECASTS AT THE SAME TIME.
&&
.AVIATION.../FOR THE 06Z TAF ISSUANCE/
AREA OF IFR STRATUS CONTINUES TO DROP SOUTHWARD ACROSS THE AREA ON A
NORTHERLY/NORTHWESTERLY LOW LEVEL FLOW. ANTICIPATE THAT IT WILL NOW
MAKE IT ALL THE WAY INTO THE SOUTHERN PORTIONS OF THE FORECAST
AREA...THOUGH SOME UNCERTAINTY ON ARRIVAL AT KSUX...GENERALLY IN THE
08Z TO 09Z TIME FRAME. VISIBILITIES ARE ALSO BEGINNING TO DROP
THROUGH THE NORTHERN I 29 CORRIDOR INTO SOUTHWESTERN MINNESOTA...AND
ANTICIPATE LOCALIZED IFR VISBYS ACROSS THE AREA. IMPROVING
CONDITIONS EXPECTED AFTER 16Z ON SUNDAY.
&&
.PREV DISCUSSION.../ISSUED AT 315 PM CST/
WITH LAST OF THE CLOUDS FROM THE SOUTHERN SYSTEM MOVING SOUTHEAST OF
AREA THIS EVENING...PROBLEM WILL BE THE POTENTIAL REDEVELOPMENT OF
STRATUS AND FOG OVER THE AREA TONIGHT AS WINDS STEADILY BECOME
LIGHT. SEEMINGLY AMPLE LOW LEVEL MOISTURE WOULD SEEM TO POINT TO
REDEVELOPMENT BUT SUBSIDENCE/WARMING/DRYING ABOVE THE SURFACE IS
BECOMING MORE EVIDENT ALL THE TIME...SUCH AS IN THE LOWERED
DEWPOINTS AT PQN AND FSD WITH THE HEATING. ANY LOW LEVEL MOISTURE
WILL TEND TO BECOME SHALLOWER WITH TIME AND THINK THIS WILL BE
ENOUGH TO KEEP THE STRATUS FROM REDEVELOPING. WILL ALLOW FOR SOME
AREAS OF FOG TO DEVELOP BUT IT WILL HAVE TO BE SHALLOW. WOULD NOT BE
SURPRISED TO SEE IT ABSENT BUT FOG IN THESE CASES DOES NOT NEED VERY
DEEP MOISTURE AND COOLING TO DEVELOP. WILL RESTRICT IT TO LATE
TONIGHT. TEMPERATURES NOT MUCH OF A PROBLEM...SHOULD COOL GENERALLY
INTO THE LOWER 20S.
IF THERE IS ANY FOG IT SHOULD GO QUICKLY SUNDAY MORNING AND LEAVE A
PRETTY SUNNY DAY WITH TEMPERATURES REBOUNDING INTO THE 40S
EVERYWHERE...NOT JUST HERE AT FSD. FAIRLY LIGHT WINDS SHOULD SHOW A
SLOW TREND FROM NORTHWEST TO WEST AND SOUTHWEST. / WILLIAMS
UNORGANIZED SPLIT FLOW WILL DOMINATE FOR MUCH OF THE NEXT WEEK...
WITH LITTLE IN THE WAY OF PRECIP CHANCES SEEN FOR OUR AREA. SOUTHERN
AND NORTHERN STREAMS ATTEMPT TO PHASE LATE MONDAY NIGHT/TUESDAY WITH
MOST MODELS SPITTING OUT SOME VERY LIGHT QPF NEAR AND SOUTH OF THE
MISSOURI VALLEY. SOUNDINGS FOR OUR AREA SHOW DEEP DRY LAYER BENEATH
THE INCREASING MID CLOUD DECK SO WILL LEAVE FORECAST DRY FOR NOW...
THOUGH FLURRIES NOT OUT OF THE QUESTION IN SOUTHERN AREAS. TIMING OF
COLD FRONT ON MONDAY SEEMS TO HAVE SLOWED A BIT FROM PREVIOUS...SO
HAVE BUMPED TEMPS A FEW DEGREES ALONG/SOUTH OF I-90. POTENTIAL FOR
WARMING IN FAR SOUTHERN AREAS A LITTLE TRICKY...AS LOW LEVEL FLOW
AHEAD OF THE FRONT WILL BE COMING OFF FRESH DEEP SNOWPACK...BUT EVEN
ISOTHERMAL FROM 925MB WOULD YIELD LOWER 40S AND A FEW DEGREES ABOVE
THAT SHOULD BE ACHIEVABLE WITH MIXING AHEAD OF THE FRONT. BREEZY
CONDITIONS IN THE COLD ADVECTION ALONG WITH INCREASING CLOUDS MONDAY
NIGHT SHOULD HOLD TEMPERATURES UP IN THE UPPER TEENS TO MID 20S...
WITH LITTLE RECOVERY EXPECTED DESPITE CLEARING ON TUESDAY. LARGER
DIURNAL RANGE EXPECTED TUESDAY NIGHT/WEDNESDAY. SURFACE RIDGE
TUESDAY NIGHT WILL ALLOW FOR GOOD RADIATIVE COOLING...ESPECIALLY
WEST WHERE CLOUDS ARE MORE LIKELY TO CLEAR. SOUTH-SOUTHWEST FLOW
COMING OFF SNOWPACK ON WEDNESDAY WILL LIKELY TEMPER WARMING SOME...
BUT READINGS NEAR TO JUST ABOVE FREEZING OVER OUR BARE GROUND SEEM
REASONABLE.
TIMING OF ARCTIC PUSH...WITH 850MB TEMPERATURES IN THE TEENS BELOW
ZERO...LOOKS TO BE ON TARGET FOR THURSDAY/THURSDAY NIGHT TIME FRAME.
HOWEVER DISCREPANCIES ABOUND IN HOW FAR WEST THE COLD AIR WILL GET
AND HOW LONG IT WILL STICK AROUND...MAKING HIGHS FOR FRIDAY THE
BIGGEST QUESTION OF THE LONGER RANGE. 00Z SATURDAY 850MB TEMPS VARY
BY 10 DEGREES ACROSS VARIOUS DETERMINISTIC MODELS...AND BY CLOSER TO
20 DEGREES AMONG THE 12Z GFS ENSEMBLE MEMBERS...LEAVING QUITE A BIT
OF ROOM FOR LARGE ERRORS IN THIS PERIOD. HOWEVER...GIVEN CONTINUED
LACK OF SNOW AND RELATIVELY DRY AIRMASS IN WAKE OF SURFACE RIDGE
WHICH MOVES THROUGH THURSDAY NIGHT...WILL ERR TOWARD WARMER SIDE OF
GUIDANCE SPECTRUM. A LITTLE MORE WARMING EXPECTED FOR SATURDAY AS
MODELS SHOW BETTER CONSENSUS IN SHIFTING THE COLDER AIR OFF TO THE
EAST.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
351 PM CST SUN FEB 5 2012
.SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...A SMALL AREA OF LIGHT
RAIN MOVING THROUGH THE CENTRAL COASTAL BEND WILL MOVE OFFSHORE
OVER THE NEXT FEW HOURS. BEYOND THAT THINK PRECIPITATION THREAT IS
MAINLY OVER FOR THE EVENING. HRRR AND RUC MODELS INDICATE A
CHANCE FOR LIGHT RAIN ALONG THE SOUTHERN BORDER OF THE FORECAST
AREA AND UP TOWARD CORPUS THROUGH THE EVENING...HOWEVER THEY BOTH
SHOW PRECIP TO THE SOUTH AND WEST AT THIS TIME THAT IS NOT BEING
REALIZED...SO THINK THEY ARE PROBABLY OVERDOING THE CHANCE
TONIGHT. WILL STILL LEAVE CHANCE WORDING EAST AND SLIGHT CHANCE
CENTRAL THROUGH THE NIGHT. WITH THE RAINFALL AMOUNTS EXPERIENCED
OVERNIGHT LAST NIGHT...AND WATER STILL STANDING IN SOME
AREAS...HAVE TO CONSIDER THE CHANCE FOR SOME PATCHY FOG TONIGHT.
SKIES TO REMAIN CLOUDY...AND WINDS IN THE EAST SHOULD STAY HIGH
ENOUGH TO LIMIT THE POSSIBILITY. HAVE NOT INCLUDED IN THE FORECAST
AT THIS TIME...BUT CAN NOT RULE IT OUT COMPLETELY.
SHOULD COOL TEMPS MORE TONIGHT WITH LOWS IN THE 40S FOR MOST OF
THE AREA. MOSTLY CLOUDY SKIES CONTINUE TOMORROW AND WILL LIMIT
WARMING. HAVE COOLED HIGH TEMPS A BIT AS MODELS SEEM TO ALL BE
COMING IN WITH COOLER SOLNS TODAY. MOISTURE BEGINS TO COME BACK
INTO THE AREA MONDAY NIGHT...BUT LOOKS LIKE PRECIP
CHANCES...EXCEPT OFFSHORE...WILL HOLD OFF UNTIL TUESDAY.
&&
.LONG TERM (TUESDAY THROUGH SUNDAY)...WEAK ISENTROPIC LIFT WILL
DEVELOP ACROSS THE COASTAL BEND TUESDAY AFTERNOON AS A MID LVL S/W
AND UPR JET STREAM MOVES OVHD...RESULTING IN A SLIGHT CHANCE OF
LIGHT PCPN. SFC RIDGE WILL BE REINFORCED OVER THE GULF WATERS
WEDNESDAY MORNING AS PROGRESSIVE TROUGH ADVANCES ACROSS THE OHIO
VALLEY. INCREASING UPR DIFLUENCE AND OMEGA WITH THE ADVANCEMENT OF
THE NEXT DEEP TROUGH DIGGING INTO BAHA WILL PRODUCE A CONTINUATION
OF LIGHT RAIN ON WEDNESDAY. 115KTS UPR JET WILL NOSE INTO SOUTH
TEXAS LATE WED NIGHT/THU AND WILL COMBINE WITH ELEVATED INSTABILITY
TO PRODUCE A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS THURSDAY...
CONTINUING THROUGH SATURDAY MORNING WHEN THE UPR LVL TROUGH AXIS
SHIFTS EAST OF THE AREA. PRECIP AMOUNTS WILL HINGE ON AMOUNT OF
MOISTURE TRANSPORT AHEAD OF THE SYSTEM...WHICH LOOKS WEAKER THAN THE
LAST SYSTEM (PWATS NEAR 1" -VS- 1.5" LAST NIGHT). NONE THE
LESS...EXPECT POTENTIAL FOR RAINFALL AND ABNORMALLY WET LA NINA
FEBRUARY TO CONTINUE MUCH OF THE WEEK. CONSIDERABLE UNCERTAINTY
WITH REGARDS TO NEXT WEEKEND AS THE GFS IS DRY IN THE WAKE OF THE
EXITING LARGE SCALE TROUGH AND THE ECMWF IS MORE PROGRESSIVE IN
BRINGING ANOTHER SOUTHERN STREAM TROUGH ACROSS THE AREA. FOR
NOW...WILL HEDGE TOWARD THE DRIER FORECAST. TEMPS WILL REMAIN BELOW
NORMAL THROUGH THE FORECAST PERIOD. SCA`S WILL DEVELOP OVER THE
GULF WATERS WED AND WILL PERSIST INTO THE WEEKEND AS SFC HIGH
PRESSURE REMAINS ANCHORED ALONG THE COAST AND THE AFORMENTIONED
STORM SYSTEM MOVES ACROSS THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 45 58 45 65 50 / 40 10 10 20 30
VICTORIA 42 58 42 64 46 / 30 10 10 20 20
LAREDO 46 63 48 66 52 / 10 10 10 10 30
ALICE 43 60 43 65 49 / 30 10 10 20 30
ROCKPORT 46 59 51 66 50 / 40 10 10 20 30
COTULLA 43 60 42 64 48 / 10 10 10 10 20
KINGSVILLE 43 60 44 66 50 / 40 10 10 20 30
NAVY CORPUS 48 60 48 67 50 / 40 10 10 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
PZ/83...SHORT TERM
JM/75...LONG TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1158 AM CST SUN FEB 5 2012
.DISCUSSION...UPDATED FOR 18Z AVIATION.
&&
.AVIATION...ANOTHER AREA OF LIGHT TO MODERATE RAIN IS LOCATED
BETWEEN LRD AND ALI AT THIS TIME. THIS AREA OF RAIN IS MOVING
EASTWARD AND WILL AFFECT THE TAF SITES OVER THE NEXT SEVERAL
HOURS. THE ACTIVITY IS ELEVATED AND CIGS SHOULD REMAIN GENERALLY
VFR...BUT MAY BECOME MVFR DURING A HEAVIER SHOWER. WINDS REMAIN
BREEZY OUT OF THE NORTH. OVERNIGHT CHANCES FOR RAIN DECREASE...BUT
CANT RULE OUT SOME LINGERING LIGHT RAIN...MAINLY IN THE SOUTHEAST.
SKIES REMAIN OVC TOMORROW WITH CIGS BORDERLINE MVFR.
&&
.PREV DISCUSSION... /ISSUED 957 AM CST SUN FEB 5 2012/
DISCUSSION...WIDESPREAD MODERATE RAIN FROM THIS MORNING HAS
PUSHED OFFSHORE. HOWEVER...ADDITIONAL LIGHT RAIN WITH EMBEDDED
MODERATE SHOWERS IS DEVELOPING UNDER THE RIGHT REAR QUAD OF AN
UPPER JET REMAINING OVER MEXICO AND WEST CENTRAL TEXAS. THE JET
WEAKENS AND SHIFTS TO THE EAST LATER TODAY WHICH SHOULD DECREASE
PRECIP CHANCES. ALTHOUGH LATEST GFS JUST COMING IN AS I TYPE THIS
SHOWS A BIT OF A JET STREAK OVER FAR EASTERN CWA OVERNIGHT...WHICH
COINCIDES WITH PRECIP INDICATED ON SOME MESO MODELS. WILL ANALYZE
MORE FOR AFTERNOON FORECAST PACKAGE. HAVE ALSO SEEN WINDS
BECOMING VERY GUSTY ALONG THE COASTAL BEND LATE THIS MORNING WITH
POSSIBLY A WEAK WAKE LOW DEVELOPING. MSAS 3HR PRESSURE CHANGE DID
INDICATE A BIT OF A MINIMUM NEAR BAFIN BAY THEN NORTHWARD TO
MATAGORDA BAY. MARGINAL WIND ADVISORY NOW IN EFFECT THROUGH NOON
FOR COASTAL COUNTIES. HAVE SEEK SEVERAL GUSTS IN THE 30 TO 40 MPH
RANGE WITH A GUST TO 46 MPH AT KNGP.
PREV DISCUSSION... /ISSUED 545 AM CST SUN FEB 5 2012/
DISCUSSION...SEE AVIATION SECTION FOR 12Z TAFS.
AVIATION...LARGE SHIELD OF PRECIPITATION WILL MOVE NORTHEAST
ACROSS SOUTH TEXAS THIS MORNING WITH A GRADUAL DECREASE FROM
WEST TO EAST AS THE UPPER LEVEL DISTURBANCE OVER NORTHERN
MEXICO MOVES NORTHEAST INTO CENTRAL TEXAS. MVFR CEILINGS/VSBYS
WILL BE PREVALENT THIS MORNING WITH PERIODIC IFR VSBYS IN THE
HEAVIER DOWNPOURS ASSOCIATED WITH EMBEDDED THUNDERSTORMS.
OVERCAST CONDITIONS WILL EXIST AS THE PRECIPITATION ACTIVITY
DIMINISHES LATE THIS AFTERNOON WITH CEILINGS RISING TO NEAR
5 KFT BRUSH COUNTRY...3500 FT FOR INLAND COASTAL PLAINS AND
CEILINGS REMAINING AROUND 3 KFT ALONG THE COAST THROUGH THE
NIGHT.
PREV DISCUSSION... /ISSUED 355 AM CST SUN FEB 5 2012/
SHORT TERM (TODAY)...LARGE SCALE ATMOSPHERIC LIFT INCREASED
LAST EVENING IN RESPONSE TO AN UPPER LEVEL JET STREAK THAT LIFTED
TO THE NORTH OF THE AREA. WIDESPREAD SHOWERS/SCATTERED THUNDERSTORMS
CONTINUE EARLY THIS MORNING WITH MORE TO COME. LARGE AREA OF
CONVECTION MOVING NORTHEAST FROM DEEP SOUTH TEXAS THIS MORNING.
WATER VAPOR IMAGERY SHOWS ANOTHER ENERGETIC UPPER LEVEL JET STREAK
LIFTING NORTH-NORTHEAST OUT OF MEXICO. LATEST RUC SHOWS A 90 KNOT
25H JET MOVING INTO COAHUILA THAT WILL MOVE INTO CENTRAL TEXAS
THIS AFTERNOON. SOUTH TEXAS WILL AGAIN BE IN A REGION OF INCREASING
LIFT IN RESPONSE TO INCREASING UPPER LEVEL DIVERGENCE. FORECAST
SOUNDINGS CONTINUE TO SHOW ELEVATED UNSTABLE LAYER ABOVE 800 MBS
REMAINING OVER THE REGION THROUGH THE DAY. GFS/ECMWF/NAM SHOW THE
85H TROUGH AXIS OVER THE BRUSH COUNTRY WITH THE GOOD MOISTURE FLUX
CONVERGENCE MOVING FROM THE BRUSH COUNTRY THROUGH THE COASTAL BEND
THROUGH THE DAY. TIME-HEIGHT CROSS SECTIONS SHOW LIFT THROUGH A
LARGE LAYER THROUGH THE MORNING INTO MID AFTERNOON. WILL GO WITH
CATEGORICAL POPS FOR MOST OF THE AREA EXCEPT WESTERN BRUSH COUNTRY
WHERE WENT WITH LIKELY POPS. QPF FORECAST WAS A BLEND OF THE
CMC/ECMWF/SREF WITH AVERAGE OF A LITTLE OVER HALF OF AN INCH ALONG
THE COAST...BUT THERE WILL BE AREAS THAT COULD RECEIVE UP TO AN
INCH. PRECIPITABLE WATER VALUES WILL BE ABOVE 1 INCH BRUSH COUNTRY
AND BE NEAR 1.5 INCHES OVER THE GULF WATERS.
MARINE (TODAY THROUGH TONIGHT)...HIGH PRESSURE BUILDING INTO THE
AREA WILL KEEP WINDS A BIT STRONGER AND REMAIN IN SCA RANGE FOR
A LITTLE LONGER. EXTENDED SCA FOR THE BAYS UNTIL 20Z AND FOR THE
GULF WATERS UNTIL 03Z MONDAY. WIDESPREAD SHOWERS AND THUNDERSTORMS
WILL CONTINUE THROUGH THE DAY WITH A DECREASE IN COVERAGE THIS
EVENING.
LONG TERM (TONIGHT THROUGH SATURDAY)...PRECIP EXPECTED TO DIMINISH
TONIGHT AS UPPER DISTURBANCE EXITS THE AREA. THE CANADIAN AND NAM
KEEP LIGHT PRECIP IN THE FCST ON MON...HOWEVER LEANED TOWARD THE
DRIER ECMWF AND GFS. MODELS CONTINUE TO PROG A SERIES OF EMBEDDED
SHORT WAVES TO TRACK ACROSS THE REGION THROUGH THE WEEK AHD OF A
POTENT CUT OFF LOW. MODELS DIFFER ON QPF EACH DAY AND THEY DIFFER ON
LOCATION OF HEAVIEST PRECIP. KEPT WITH THE CHC POPS DVLPG ACROSS THE
SRN CWA BY TUE NITE AND SHIFTING INTO THE WESTERN HALF OF THE CWA
THRU WED. THEN AS THE UPPER LOW MOVES ACROSS MEX TOWARD TX...UPPER
DIFFLUENCE INCREASES. THE HIGHEST PWATS ARE PROGD FOR THU AND LOW
LEVEL MOISTURE CONVERGENCE INCREASES AS A COLD FRONT/REINFORCING
HIGH PRESSURE PUSHES S INTO THE AREA. THEREFORE KEPT THE 50 POPS
ACROSS THE WEST DUE TO PROXIMITY TO UPPER LOW/BEST DYNAMICS. KEPT A
BROADBRUSHED 30 POP FOR FRI AS MODELS BEGIN TO DIVERGE ON
PLACEMENT/STRENGTH OF UPPER LOW AND CORRESPONDING PRECIP. GFS SHOWS
A DRIER FCST BY SAT AFTERNOON AS THE UPPER SYSTEM PUSHES THRU THE
AREA AND A NW FLOW ALOFT DVLPS. THE ECMWF IS A TAD SLOWER. WENT WITH
A BROADBRUSHED 20 POP ON SAT FOR NOW. AS FOR TEMPS...WENT WITH A
WARMING TREND MON THRU THU AHD OF COLD FRONT...THEN A SLIGHT COOLING
TREND FRI AND SAT IN THE WAKE OF THE COLD FRONT. OVERALL TEMPS ARE
PROGD TO BE GENERALLY BELOW NORMAL THROUGH THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 50 44 60 45 65 / 80 40 10 10 20
VICTORIA 50 41 58 42 64 / 80 20 10 10 20
LAREDO 54 46 61 46 66 / 60 10 10 10 10
ALICE 51 43 59 42 65 / 80 30 10 10 20
ROCKPORT 51 46 60 49 66 / 80 40 10 10 20
COTULLA 52 41 59 42 64 / 70 10 10 10 10
KINGSVILLE 50 43 59 44 66 / 80 40 10 10 20
NAVY CORPUS 52 46 60 48 67 / 80 40 10 10 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT
O`CONNOR.
&&
$$
PZ/83...SHORT TERM
TE/81...LONG TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
957 AM CST SUN FEB 5 2012
.DISCUSSION...WIDESPREAD MODERATE RAIN FROM THIS MORNING HAS
PUSHED OFFSHORE. HOWEVER...ADDITIONAL LIGHT RAIN WITH EMBEDDED
MODERATE SHOWERS IS DEVELOPING UNDER THE RIGHT REAR QUAD OF AN
UPPER JET REMAINING OVER MEXICO AND WEST CENTRAL TEXAS. THE JET
WEAKENS AND SHIFTS TO THE EAST LATER TODAY WHICH SHOULD DECREASE
PRECIP CHANCES. ALTHOUGH LATEST GFS JUST COMING IN AS I TYPE THIS
SHOWS A BIT OF A JET STREAK OVER FAR EASTERN CWA OVERNIGHT...WHICH
COINCIDES WITH PRECIP INDICATED ON SOME MESO MODELS. WILL ANALYZE
MORE FOR AFTERNOON FORECAST PACKAGE. HAVE ALSO SEEN WINDS
BECOMING VERY GUSTY ALONG THE COASTAL BEND LATE THIS MORNING WITH
POSSIBLY A WEAK WAKE LOW DEVELOPING. MSAS 3HR PRESSURE CHANGE DID
INDICATE A BIT OF A MINIMUM NEAR BAFIN BAY THEN NORTHWARD TO
MATAGORDA BAY. MARGINAL WIND ADVISORY NOW IN EFFECT THROUGH NOON
FOR COASTAL COUNTIES. HAVE SEEK SEVERAL GUSTS IN THE 30 TO 40 MPH
RANGE WITH A GUST TO 46 MPH AT KNGP.
&&
.PREV DISCUSSION... /ISSUED 545 AM CST SUN FEB 5 2012/
DISCUSSION...SEE AVIATION SECTION FOR 12Z TAFS.
AVIATION...LARGE SHIELD OF PRECIPITATION WILL MOVE NORTHEAST
ACROSS SOUTH TEXAS THIS MORNING WITH A GRADUAL DECREASE FROM
WEST TO EAST AS THE UPPER LEVEL DISTURBANCE OVER NORTHERN
MEXICO MOVES NORTHEAST INTO CENTRAL TEXAS. MVFR CEILINGS/VSBYS
WILL BE PREVALENT THIS MORNING WITH PERIODIC IFR VSBYS IN THE
HEAVIER DOWNPOURS ASSOCIATED WITH EMBEDDED THUNDERSTORMS.
OVERCAST CONDITIONS WILL EXIST AS THE PRECIPITATION ACTIVITY
DIMINISHES LATE THIS AFTERNOON WITH CEILINGS RISING TO NEAR
5 KFT BRUSH COUNTRY...3500 FT FOR INLAND COASTAL PLAINS AND
CEILINGS REMAINING AROUND 3 KFT ALONG THE COAST THROUGH THE
NIGHT.
PREV DISCUSSION... /ISSUED 355 AM CST SUN FEB 5 2012/
SHORT TERM (TODAY)...LARGE SCALE ATMOSPHERIC LIFT INCREASED
LAST EVENING IN RESPONSE TO AN UPPER LEVEL JET STREAK THAT LIFTED
TO THE NORTH OF THE AREA. WIDESPREAD SHOWERS/SCATTERED THUNDERSTORMS
CONTINUE EARLY THIS MORNING WITH MORE TO COME. LARGE AREA OF
CONVECTION MOVING NORTHEAST FROM DEEP SOUTH TEXAS THIS MORNING.
WATER VAPOR IMAGERY SHOWS ANOTHER ENERGETIC UPPER LEVEL JET STREAK
LIFTING NORTH-NORTHEAST OUT OF MEXICO. LATEST RUC SHOWS A 90 KNOT
25H JET MOVING INTO COAHUILA THAT WILL MOVE INTO CENTRAL TEXAS
THIS AFTERNOON. SOUTH TEXAS WILL AGAIN BE IN A REGION OF INCREASING
LIFT IN RESPONSE TO INCREASING UPPER LEVEL DIVERGENCE. FORECAST
SOUNDINGS CONTINUE TO SHOW ELEVATED UNSTABLE LAYER ABOVE 800 MBS
REMAINING OVER THE REGION THROUGH THE DAY. GFS/ECMWF/NAM SHOW THE
85H TROUGH AXIS OVER THE BRUSH COUNTRY WITH THE GOOD MOISTURE FLUX
CONVERGENCE MOVING FROM THE BRUSH COUNTRY THROUGH THE COASTAL BEND
THROUGH THE DAY. TIME-HEIGHT CROSS SECTIONS SHOW LIFT THROUGH A
LARGE LAYER THROUGH THE MORNING INTO MID AFTERNOON. WILL GO WITH
CATEGORICAL POPS FOR MOST OF THE AREA EXCEPT WESTERN BRUSH COUNTRY
WHERE WENT WITH LIKELY POPS. QPF FORECAST WAS A BLEND OF THE
CMC/ECMWF/SREF WITH AVERAGE OF A LITTLE OVER HALF OF AN INCH ALONG
THE COAST...BUT THERE WILL BE AREAS THAT COULD RECEIVE UP TO AN
INCH. PRECIPITABLE WATER VALUES WILL BE ABOVE 1 INCH BRUSH COUNTRY
AND BE NEAR 1.5 INCHES OVER THE GULF WATERS.
MARINE (TODAY THROUGH TONIGHT)...HIGH PRESSURE BUILDING INTO THE
AREA WILL KEEP WINDS A BIT STRONGER AND REMAIN IN SCA RANGE FOR
A LITTLE LONGER. EXTENDED SCA FOR THE BAYS UNTIL 20Z AND FOR THE
GULF WATERS UNTIL 03Z MONDAY. WIDESPREAD SHOWERS AND THUNDERSTORMS
WILL CONTINUE THROUGH THE DAY WITH A DECREASE IN COVERAGE THIS
EVENING.
LONG TERM (TONIGHT THROUGH SATURDAY)...PRECIP EXPECTED TO DIMINISH
TONIGHT AS UPPER DISTURBANCE EXITS THE AREA. THE CANADIAN AND NAM
KEEP LIGHT PRECIP IN THE FCST ON MON...HOWEVER LEANED TOWARD THE
DRIER ECMWF AND GFS. MODELS CONTINUE TO PROG A SERIES OF EMBEDDED
SHORT WAVES TO TRACK ACROSS THE REGION THROUGH THE WEEK AHD OF A
POTENT CUT OFF LOW. MODELS DIFFER ON QPF EACH DAY AND THEY DIFFER ON
LOCATION OF HEAVIEST PRECIP. KEPT WITH THE CHC POPS DVLPG ACROSS THE
SRN CWA BY TUE NITE AND SHIFTING INTO THE WESTERN HALF OF THE CWA
THRU WED. THEN AS THE UPPER LOW MOVES ACROSS MEX TOWARD TX...UPPER
DIFFLUENCE INCREASES. THE HIGHEST PWATS ARE PROGD FOR THU AND LOW
LEVEL MOISTURE CONVERGENCE INCREASES AS A COLD FRONT/REINFORCING
HIGH PRESSURE PUSHES S INTO THE AREA. THEREFORE KEPT THE 50 POPS
ACROSS THE WEST DUE TO PROXIMITY TO UPPER LOW/BEST DYNAMICS. KEPT A
BROADBRUSHED 30 POP FOR FRI AS MODELS BEGIN TO DIVERGE ON
PLACEMENT/STRENGTH OF UPPER LOW AND CORRESPONDING PRECIP. GFS SHOWS
A DRIER FCST BY SAT AFTERNOON AS THE UPPER SYSTEM PUSHES THRU THE
AREA AND A NW FLOW ALOFT DVLPS. THE ECMWF IS A TAD SLOWER. WENT WITH
A BROADBRUSHED 20 POP ON SAT FOR NOW. AS FOR TEMPS...WENT WITH A
WARMING TREND MON THRU THU AHD OF COLD FRONT...THEN A SLIGHT COOLING
TREND FRI AND SAT IN THE WAKE OF THE COLD FRONT. OVERALL TEMPS ARE
PROGD TO BE GENERALLY BELOW NORMAL THROUGH THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 50 44 60 45 65 / 80 40 10 10 20
VICTORIA 50 41 58 42 64 / 80 20 10 10 20
LAREDO 54 46 61 46 66 / 60 10 10 10 10
ALICE 51 43 59 42 65 / 80 30 10 10 20
ROCKPORT 51 46 60 49 66 / 80 40 10 10 20
COTULLA 52 41 59 42 64 / 70 10 10 10 10
KINGSVILLE 50 43 59 44 66 / 80 40 10 10 20
NAVY CORPUS 52 46 60 48 67 / 80 40 10 10 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT
O`CONNOR.
&&
$$
PZ/83...SHORT TERM
TE/81...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
545 AM CST SUN FEB 5 2012
.DISCUSSION...SEE AVIATION SECTION FOR 12Z TAFS.
&&
.AVIATION...LARGE SHIELD OF PRECIPITATION WILL MOVE NORTHEAST
ACROSS SOUTH TEXAS THIS MORNING WITH A GRADUAL DECREASE FROM
WEST TO EAST AS THE UPPER LEVEL DISTURBANCE OVER NORTHERN
MEXICO MOVES NORTHEAST INTO CENTRAL TEXAS. MVFR CEILINGS/VSBYS
WILL BE PREVALENT THIS MORNING WITH PERIODIC IFR VSBYS IN THE
HEAVIER DOWNPOURS ASSOCIATED WITH EMBEDDED THUNDERSTORMS.
OVERCAST CONDITIONS WILL EXIST AS THE PRECIPITATION ACTIVITY
DIMINISHES LATE THIS AFTERNOON WITH CEILINGS RISING TO NEAR
5 KFT BRUSH COUNTRY...3500 FT FOR INLAND COASTAL PLAINS AND
CEILINGS REMAINING AROUND 3 KFT ALONG THE COAST THROUGH THE
NIGHT.
&&
.PREV DISCUSSION... /ISSUED 355 AM CST SUN FEB 5 2012/
SHORT TERM (TODAY)...LARGE SCALE ATMOSPHERIC LIFT INCREASED
LAST EVENING IN RESPONSE TO AN UPPER LEVEL JET STREAK THAT LIFTED
TO THE NORTH OF THE AREA. WIDESPREAD SHOWERS/SCATTERED THUNDERSTORMS
CONTINUE EARLY THIS MORNING WITH MORE TO COME. LARGE AREA OF
CONVECTION MOVING NORTHEAST FROM DEEP SOUTH TEXAS THIS MORNING.
WATER VAPOR IMAGERY SHOWS ANOTHER ENERGETIC UPPER LEVEL JET STREAK
LIFTING NORTH-NORTHEAST OUT OF MEXICO. LATEST RUC SHOWS A 90 KNOT
25H JET MOVING INTO COAHUILA THAT WILL MOVE INTO CENTRAL TEXAS
THIS AFTERNOON. SOUTH TEXAS WILL AGAIN BE IN A REGION OF INCREASING
LIFT IN RESPONSE TO INCREASING UPPER LEVEL DIVERGENCE. FORECAST
SOUNDINGS CONTINUE TO SHOW ELEVATED UNSTABLE LAYER ABOVE 800 MBS
REMAINING OVER THE REGION THROUGH THE DAY. GFS/ECMWF/NAM SHOW THE
85H TROUGH AXIS OVER THE BRUSH COUNTRY WITH THE GOOD MOISTURE FLUX
CONVERGENCE MOVING FROM THE BRUSH COUNTRY THROUGH THE COASTAL BEND
THROUGH THE DAY. TIME-HEIGHT CROSS SECTIONS SHOW LIFT THROUGH A
LARGE LAYER THROUGH THE MORNING INTO MID AFTERNOON. WILL GO WITH
CATEGORICAL POPS FOR MOST OF THE AREA EXCEPT WESTERN BRUSH COUNTRY
WHERE WENT WITH LIKELY POPS. QPF FORECAST WAS A BLEND OF THE
CMC/ECMWF/SREF WITH AVERAGE OF A LITTLE OVER HALF OF AN INCH ALONG
THE COAST...BUT THERE WILL BE AREAS THAT COULD RECEIVE UP TO AN
INCH. PRECIPITABLE WATER VALUES WILL BE ABOVE 1 INCH BRUSH COUNTRY
AND BE NEAR 1.5 INCHES OVER THE GULF WATERS.
MARINE (TODAY THROUGH TONIGHT)...HIGH PRESSURE BUILDING INTO THE
AREA WILL KEEP WINDS A BIT STRONGER AND REMAIN IN SCA RANGE FOR
A LITTLE LONGER. EXTENDED SCA FOR THE BAYS UNTIL 20Z AND FOR THE
GULF WATERS UNTIL 03Z MONDAY. WIDESPREAD SHOWERS AND THUNDERSTORMS
WILL CONTINUE THROUGH THE DAY WITH A DECREASE IN COVERAGE THIS
EVENING.
LONG TERM (TONIGHT THROUGH SATURDAY)...PRECIP EXPECTED TO DIMINISH
TONIGHT AS UPPER DISTURBANCE EXITS THE AREA. THE CANADIAN AND NAM
KEEP LIGHT PRECIP IN THE FCST ON MON...HOWEVER LEANED TOWARD THE
DRIER ECMWF AND GFS. MODELS CONTINUE TO PROG A SERIES OF EMBEDDED
SHORT WAVES TO TRACK ACROSS THE REGION THROUGH THE WEEK AHD OF A
POTENT CUT OFF LOW. MODELS DIFFER ON QPF EACH DAY AND THEY DIFFER ON
LOCATION OF HEAVIEST PRECIP. KEPT WITH THE CHC POPS DVLPG ACROSS THE
SRN CWA BY TUE NITE AND SHIFTING INTO THE WESTERN HALF OF THE CWA
THRU WED. THEN AS THE UPPER LOW MOVES ACROSS MEX TOWARD TX...UPPER
DIFFLUENCE INCREASES. THE HIGHEST PWATS ARE PROGD FOR THU AND LOW
LEVEL MOISTURE CONVERGENCE INCREASES AS A COLD FRONT/REINFORCING
HIGH PRESSURE PUSHES S INTO THE AREA. THEREFORE KEPT THE 50 POPS
ACROSS THE WEST DUE TO PROXIMITY TO UPPER LOW/BEST DYNAMICS. KEPT A
BROADBRUSHED 30 POP FOR FRI AS MODELS BEGIN TO DIVERGE ON
PLACEMENT/STRENGTH OF UPPER LOW AND CORRESPONDING PRECIP. GFS SHOWS
A DRIER FCST BY SAT AFTERNOON AS THE UPPER SYSTEM PUSHES THRU THE
AREA AND A NW FLOW ALOFT DVLPS. THE ECMWF IS A TAD SLOWER. WENT WITH
A BROADBRUSHED 20 POP ON SAT FOR NOW. AS FOR TEMPS...WENT WITH A
WARMING TREND MON THRU THU AHD OF COLD FRONT...THEN A SLIGHT COOLING
TREND FRI AND SAT IN THE WAKE OF THE COLD FRONT. OVERALL TEMPS ARE
PROGD TO BE GENERALLY BELOW NORMAL THROUGH THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 50 44 60 45 65 / 80 40 10 10 20
VICTORIA 50 41 58 42 64 / 80 20 10 10 20
LAREDO 54 46 61 46 66 / 60 10 10 10 10
ALICE 51 43 59 42 65 / 80 30 10 10 20
ROCKPORT 51 46 60 49 66 / 80 40 10 10 20
COTULLA 52 41 59 42 64 / 70 10 10 10 10
KINGSVILLE 50 43 59 44 66 / 80 40 10 10 20
NAVY CORPUS 52 46 60 48 67 / 80 40 10 10 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT
O`CONNOR.
&&
$$
TMT/89...SHORT TERM/AVIATION
TE/81...LONG TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
355 AM CST SUN FEB 5 2012
.SHORT TERM (TODAY)...LARGE SCALE ATMOSPHERIC LIFT INCREASED
LAST EVENING IN RESPONSE TO AN UPPER LEVEL JET STREAK THAT LIFTED
TO THE NORTH OF THE AREA. WIDESPREAD SHOWERS/SCATTERED THUNDERSTORMS
CONTINUE EARLY THIS MORNING WITH MORE TO COME. LARGE AREA OF
CONVECTION MOVING NORTHEAST FROM DEEP SOUTH TEXAS THIS MORNING.
WATER VAPOR IMAGERY SHOWS ANOTHER ENERGETIC UPPER LEVEL JET STREAK
LIFTING NORTH-NORTHEAST OUT OF MEXICO. LATEST RUC SHOWS A 90 KNOT
25H JET MOVING INTO COAHUILA THAT WILL MOVE INTO CENTRAL TEXAS
THIS AFTERNOON. SOUTH TEXAS WILL AGAIN BE IN A REGION OF INCREASING
LIFT IN RESPONSE TO INCREASING UPPER LEVEL DIVERGENCE. FORECAST
SOUNDINGS CONTINUE TO SHOW ELEVATED UNSTABLE LAYER ABOVE 800 MBS
REMAINING OVER THE REGION THROUGH THE DAY. GFS/ECMWF/NAM SHOW THE
85H TROUGH AXIS OVER THE BRUSH COUNTRY WITH THE GOOD MOISTURE FLUX
CONVERGENCE MOVING FROM THE BRUSH COUNTRY THROUGH THE COASTAL BEND
THROUGH THE DAY. TIME-HEIGHT CROSS SECTIONS SHOW LIFT THROUGH A
LARGE LAYER THROUGH THE MORNING INTO MID AFTERNOON. WILL GO WITH
CATEGORICAL POPS FOR MOST OF THE AREA EXCEPT WESTERN BRUSH COUNTRY
WHERE WENT WITH LIKELY POPS. QPF FORECAST WAS A BLEND OF THE
CMC/ECMWF/SREF WITH AVERAGE OF A LITTLE OVER HALF OF AN INCH ALONG
THE COAST...BUT THERE WILL BE AREAS THAT COULD RECEIVE UP TO AN
INCH. PRECIPITABLE WATER VALUES WILL BE ABOVE 1 INCH BRUSH COUNTRY
AND BE NEAR 1.5 INCHES OVER THE GULF WATERS.
&&
.MARINE (TODAY THROUGH TONIGHT)...HIGH PRESSURE BUILDING INTO THE
AREA WILL KEEP WINDS A BIT STRONGER AND REMAIN IN SCA RANGE FOR
A LITTLE LONGER. EXTENDED SCA FOR THE BAYS UNTIL 20Z AND FOR THE
GULF WATERS UNTIL 03Z MONDAY. WIDESPREAD SHOWERS AND THUNDERSTORMS
WILL CONTINUE THROUGH THE DAY WITH A DECREASE IN COVERAGE THIS
EVENING.
&&
.LONG TERM (TONIGHT THROUGH SATURDAY)...PRECIP EXPECTED TO DIMINISH
TONIGHT AS UPPER DISTURBANCE EXITS THE AREA. THE CANADIAN AND NAM
KEEP LIGHT PRECIP IN THE FCST ON MON...HOWEVER LEANED TOWARD THE
DRIER ECMWF AND GFS. MODELS CONTINUE TO PROG A SERIES OF EMBEDDED
SHORT WAVES TO TRACK ACROSS THE REGION THROUGH THE WEEK AHD OF A
POTENT CUT OFF LOW. MODELS DIFFER ON QPF EACH DAY AND THEY DIFFER ON
LOCATION OF HEAVIEST PRECIP. KEPT WITH THE CHC POPS DVLPG ACROSS THE
SRN CWA BY TUE NITE AND SHIFTING INTO THE WESTERN HALF OF THE CWA
THRU WED. THEN AS THE UPPER LOW MOVES ACROSS MEX TOWARD TX...UPPER
DIFFLUENCE INCREASES. THE HIGHEST PWATS ARE PROGD FOR THU AND LOW
LEVEL MOISTURE CONVERGENCE INCREASES AS A COLD FRONT/REINFORCING
HIGH PRESSURE PUSHES S INTO THE AREA. THEREFORE KEPT THE 50 POPS
ACROSS THE WEST DUE TO PROXIMITY TO UPPER LOW/BEST DYNAMICS. KEPT A
BROADBRUSHED 30 POP FOR FRI AS MODELS BEGIN TO DIVERGE ON
PLACEMENT/STRENGTH OF UPPER LOW AND CORRESPONDING PRECIP. GFS SHOWS
A DRIER FCST BY SAT AFTERNOON AS THE UPPER SYSTEM PUSHES THRU THE
AREA AND A NW FLOW ALOFT DVLPS. THE ECMWF IS A TAD SLOWER. WENT WITH
A BROADBRUSHED 20 POP ON SAT FOR NOW. AS FOR TEMPS...WENT WITH A
WARMING TREND MON THRU THU AHD OF COLD FRONT...THEN A SLIGHT COOLING
TREND FRI AND SAT IN THE WAKE OF THE COLD FRONT. OVERALL TEMPS ARE
PROGD TO BE GENERALLY BELOW NORMAL THROUGH THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 50 44 60 45 65 / 80 40 10 10 20
VICTORIA 50 41 58 42 64 / 80 20 10 10 20
LAREDO 54 46 61 46 66 / 60 10 10 10 10
ALICE 51 43 59 42 65 / 80 30 10 10 20
ROCKPORT 51 46 60 49 66 / 80 40 10 10 20
COTULLA 52 41 59 42 64 / 70 10 10 10 10
KINGSVILLE 50 43 59 44 66 / 80 40 10 10 20
NAVY CORPUS 52 46 60 48 67 / 80 40 10 10 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO PORT
ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM BAFFIN BAY
TO PORT ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...BAYS AND WATERWAYS FROM PORT ARANSAS TO PORT
O`CONNOR.
&&
$$
TMT/89...SHORT TERM
TE/81...LONG TERM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
941 PM CST MON FEB 6 2012
.SHORT TERM...OVERNIGHT
941 PM CST MON FEB 6 2012
THE 07.00Z NAM/WRF AND LATEST RUC SOUNDINGS SHOW GENERALLY DRY AIR
BELOW 800 FEET WHEN THE BEST LIFT IS MOVING INTO THE REGION.
LOOKING AT THE TOP OF SOUNDINGS...THE TEMPERATURES ARE COLD ENOUGH
FOR SOME ICE CRYSTALS INTRODUCTION. THEREFORE IF THERE IS
PRECIPITATION IT WOULD BE IN THE FORM OF FLURRIES...THUS...REMOVED
THE FREEZING DRIZZLE FROM THE FORECAST. WITH THERE BEING NO REPORTS OF
PRECIPITATION UPSTREAM...BEGINNING TO WONDER IF THE MODELS ARE
OVERDOING THE MOISTURE A BIT. HOWEVER NOT CONFIDENT ENOUGH TO
REMOVE THE FLURRIES FROM THE FORECAST AT THIS TIME.
ALSO BEEN NOTICING THAT THE TEMPERATURES ARE RISING AS THE CLOUDS
MOVE INTO THE AREAS FROM THE NORTH. THE NAM/WRF SEEMS TO HAVE A
GOOD HANDLE ON THIS...SO TRENDED THE HOURLY GRIDS THAT WAY. IT DID
NOT MAKE A HUGE CHANGE IN THE FORECAST MINIMUM TEMPERATURES...BUT
THE HOURLY TEMPERATURE TRACES WILL BETTER REFLECT REALITY.
.LONG TERM...FRIDAY THROUGH MONDAY
252 PM CST MON FEB 6 2012
06.12Z ECMWF AND GFS BOTH SHOW ANOTHER SHOT OF COLD AIR DROPPING
INTO THE REGION ON FRIDAY BEHIND THE AFOREMENTIONED COLD FRONT AS
HIGH PRESSURE BUILDS ACROSS THE PLAINS. THIS WILL KEEP TEMPERATURES
AT OR BELOW NORMAL FOR SATURDAY INTO SUNDAY WITH DRY WEATHER. HOW
MUCH MODERATION OCCURS SUNDAY AND MONDAY ARE THE BIG DIFFERENCES IN
THE MODELS. GFS QUICKER IN TAKING TROUGH OVER THE AREA EASTWARD AND
BUILDING THE RIDGE IN. HENCE 850MB TEMPERATURES CLIMB TO AROUND 0
MONDAY...WILE THE ECMWF KEEPS THE COLDER AIR ENTRENCHED WITH 850MB
TEMPERATURES AROUND -8 CELSIUS. BOTH DO GENERATE A LITTLE
PRECIPITATION ON THE BACK SIDE OF THE HIGH MONDAY...BUT TYPE IS A
PROBLEM AT THIS POINT BASED ON TEMPERATURES. THUS WENT WITH A CHANCE
OF RAIN OR SNOW.
&&
.AVIATION...TONIGHT AND TUESDAY
557 PM CST MON FEB 6 2012
A SURFACE COLD FRONT IS CURRENTLY LOCATED ACROSS CENTRAL WISCONSIN
AND MINNESOTA DENOTED BY NORTHERLY WIND SHIFT. THE STRATUS DECK
EARLIER IN THE DAY ACROSS THE AREA HAS COMPLETELY ERODED AND FOCUS
TURNS TO THE MVFR POST-FRONTAL STRATUS...WHICH HAS CEILINGS MAINLY
BETWEEN 1500 TO 2500 FT. THESE CLOUDS ARE ROUGHLY 3 TO 4 HOURS
LAGGED BEHIND THE FRONT ITSELF...AND MOVEMENT APPEARS TO BE
SLOWING A BIT. THUS WILL DELAY THE ONSET TO 09Z AT BOTH KRST/KLSE.
AS FAR AS PRECIPITATION...KEPT SNOW FLURRIES BEGINNING AT 09Z AS
FORECAST SOUNDINGS SHOW INITIALLY MOISTURE IS LIMITED. EVENTUALLY
ENOUGH SATURATION OCCURS TO SUPPORT SCATTERED FLURRIES. ALSO...LACK OF
SATURATION ALOFT LIMITS ICE CRYSTAL GROWTH...AND COULD LEAD TO
SOME FREEZING DRIZZLE BRIEFLY. CONFIDENCE IS LOW ON THIS SCENARIO
THUS DID NOT INCLUDE IN TAFS...BUT WILL NEED TO BE MONITORED
CLOSELY.
DRIER AIR FILTERING IN AND A WELL-MIXED BOUNDARY LAYER SHOULD
ALLOW CLOUDS TO BREAK UP...RETURNING BOTH TAF SITES TO VFR BY
MORNING. SOME HIGH LEVEL CLOUDS / 12 TO 15 KFT / ARE EXPECTED IN THE
AFTERNOON AS HIGH PRESSURE BEGINS TO BUILD IN TUESDAY EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
252 PM CST MON FEB 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...RABERDING
AVIATION...ZBT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
341 PM CST SUN FEB 5 2012
.SHORT TERM...TONIGHT THROUGH WEDNESDAY
340 PM CST SUN FEB 5 2012
AT 3 PM...A 1033 MB HIGH WAS LOCATED ACROSS NEBRASKA AND KANSAS. A
SUBSIDENCE INVERSION ASSOCIATED WITH THIS HIGH REMAINS ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY. MOISTURE TRAPPED BENEATH THIS
INVERSION HAS KEPT SKIES GENERALLY CLOUDY AND THIS HAS PREVENTED
THE TEMPERATURES FROM RISING OUT OF THE LOWER 30S. THE ONLY
EXCEPTION IS NORTH CENTRAL AND CENTRAL WISCONSIN WHERE THERE HAS
BEEN SUNSHINE MUCH OF THE AFTERNOON...AND THIS ALLOWED
TEMPERATURES TO CLIMB INTO THE MID AND UPPER 30S IN THESE AREAS.
WITH LOW CLOUDS SPREADING EAST...THESE AREAS WILL LIKELY HAVE TO
CONTEND WITH SOME CLOUDS FOR AT LEAST THIS EVENING.
THE MAIN FORECAST QUESTION TONIGHT AND EARLY MONDAY IS WHETHER THE
CLEARING LOCATED WILL MAKE IT INTO THE AREA. HRRR AND RUC SUGGEST
THAT THIS CLEARING WILL NOT MAKE IT INTO MUCH OF THE AREA /ONE
EXCEPTION IS NORTH CENTRAL WISCONSIN/ TONIGHT...AND WE WILL HAVE
TO WAIT UNTIL MONDAY MORNING WHEN THE WESTERLY DOWN SLOPE WIND MOVES
INTO THE AREA AHEAD OF THE FRONT. HOWEVER THERE IS ALSO A POSSIBILITY
THAT THIS AIR MASS MAY BE ISENTOPICALLY LIFTED UP AND OVER THE LOW
LEVEL MOISTURE AND THE AREA WILL REMAIN IN CLOUDS. WITH QUITE A
BIT OF CLEARING TAKING PLACE ACROSS THE DAKOTAS... DECIDED TO GO
MORE OPTIMISTIC. IF WE ARE ABLE TO GET SOME SUNSHINE...TEMPERATURES
WILL CLIMB INTO THE MID AND UPPER 40S. HOWEVER IF THE CLOUDS FAIL
TO BREAK UP...TEMPERATURES WILL REMAIN IN THE 30S. SINCE THERE IS
SOME UNCERTAINTY...DECIDED TO TAKE A BIT OF CONSERVATIVE APPROACH
AND JUST GO WITH TEMPERATURES IN THE LOWER AND MID 40S.
UNLIKE YESTERDAY...THE MODELS HAVE ONCE AGAIN HAVE SPEED UP THE
CANADIAN COLD FRONT. IT NOW LOOKS LIKE THE FRONT WILL MOVE THROUGH
THE AREAS NORTH OF THE INTERSTATE 90 CORRIDOR LATE MONDAY
AFTERNOON AND THROUGH THE REMAINDER OF THE AREA DURING THE
EVENING. THE COLD AIR IS LAGGING THIS FRONT BY ABOUT 9 TO
12 HOURS...SO NOT EXPECTING THE LOWS ON MONDAY NIGHT TO BE
SIGNIFICANTLY COLDER THAN THEY ARE TONIGHT. IN THE WAKE OF THIS
FRONT...IT CONTINUES TO LOOK LIKE THERE WILL BE CLOUDS AND
FLURRIES. THE NAM/WRF CONTINUES TO HAVE DEEPER MOISTURE THAN THE
GFS...BUT THERE IS NOT ENOUGH OF A DIFFERENCE TO PRECLUDE FLURRIES
FROM OCCURRING ON MONDAY NIGHT AND TUESDAY.
IN ADDITION OVER THE PAST COUPLE OF DAYS...IT LOOKED LIKE SKIES
WOULD CLEAR OUT QUICKLY BEHIND THE FRONT...BUT A CAREFUL
EXAMINATION OF SOUNDINGS AND THE LAYER BELOW 875 MB LOOKS LIKE A
DECK OF STRATUS WILL LINGER ACROSS THE AREA THROUGH TUESDAY...AND
THEN MODELS DIFFER WITH THE GFS CLEARING MUCH OF THE AREA OUT ON
TUESDAY NIGHT AND THE NAM/WRF KEEPING THE AREA CLOUDY THROUGH
WEDNESDAY. ACTUALLY PREFER THE LATTER SOLUTION. HOWEVER WITH SUCH
A DIFFERENCE IN THE MODELS...DECIDED TO JUST GO WITH A BLEND OF
THEM.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
340 PM CST SUN FEB 5 2012
ON THURSDAY...THE 05.12Z MODELS CONTINUE TO SUGGEST THAT SOME
WARMING WILL TAKE PLACE AHEAD OF THE NEXT CANADIAN COLD FRONT. THE
ECMWF ACTUALLY WARMS TEMPERATURES IN THE UPPER 30S. MEANWHILE THE
GEM KEEPS TEMPERATURES MAINLY IN THE MID AND UPPER 20S. SINCE
THERE WAS SUCH A DIFFERENCE AND THE ECMWF USUALLY DOES BETTER FOR
THIS TIME PERIOD...DECIDED TO GO WITH A BLEND OF THESE TWO.
ON FRIDAY...IT CONTINUE TO LOOK LIKE THE COLDEST AIR WILL BE
LOCATED ACROSS THE AREA. HOWEVER WITH THIS SAID...IT IS STILL A
MUCH WARMER SOLUTION THAN WHAT IT LOOKED LIKE 3 DAYS AGO. HIGH
TEMPERATURES ON THIS DAY WILL LIKELY RANGE FROM THE TEENS TO MID
20S WHICH IS ONLY 5 TO 10 DEGREES BELOW NORMAL.
LIKE THE PAST COUPLE OF DAYS...IT LOOKS LIKE THE LONG WAVE TROUGH
WILL MOVE QUICKLY OUT OF THE AREA DURING NEXT WEEKEND...AND THE
AREA WILL ONCE AGAIN SEE A RETURN TO ABOVE-NORMAL TEMPERATURES.
THE ECMWF IS BY FAR THE MOST AGGRESSIVE WITH ITS HIGH TEMPERATURES
IN THE MID AND UPPER 40S BY SUNDAY.
&&
.AVIATION...THROUGH 18Z MONDAY
1156 AM CST SUN FEB 5 2012
FORECAST AGAIN DEALS WITH STRATUS. AS OF 18Z SUNDAY...STRATUS
EXISTS ACROSS ABOUT THE SOUTHERN 2/3 OF MINNESOTA AND MOST OF
IOWA...INCLUDING ADJACENT AREAS OF WISCONSIN. CEILINGS RANGE FROM
LIFR TO IFR WITH VISIBILITIES NOW MOSTLY MVFR. DAYTIME MIXING AND
A GRADUAL INCREASING WEST WIND WILL LIKELY ERODE SOME OF THE
STRATUS THROUGH TONIGHT...ESPECIALLY ALONG AND NORTH OF I-94.
FOR THE TAF SITES...THE INCREASING WEST WIND REALLY DOES NOT OCCUR
UNTIL TONIGHT. WITHOUT THE DAYTIME MIXING HELPING OUT...THE
INCREASING WEST WIND MAY NOT BE ENOUGH TO ERODE THE STRATUS. THIS
IS IN AGREEMENT WITH MODEL FORECASTS TOO. THEREFORE...HAVE WENT
MUCH MORE PESSIMISTIC WITH THE AVIATION FORECAST. LOOKS LIKE
AROUND 15-16Z MONDAY...THE CLOUDS SHOULD SCATTER OUT AT THE TAF
SITES DUE TO A COMBINATION OF THE DAYTIME MIXING...THE WESTERLY
WINDS AND AN APPROACHING COLD FRONT FROM THE NORTH. LOOKING
AHEAD...ADDITIONAL LOW STRATUS APPEARS POSSIBLE ONCE THE COLD FRONT
PASSES LATE MONDAY.
IF THE STRATUS OVER SOUTHWEST AND SOUTH CENTRAL MINNESOTA CAN
DISSIPATE MORE THAN EXPECTED...THEN CLEARING WOULD COME INTO
THE TAF SITES EARLIER...PROBABLY MORE 03-04Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
340 PM CST SUN FEB 5 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...AJ
STRATUS WILL BE INCLUDED IN THE NEXT AREA FORECAST DISCUSSION
LATER THIS AFTERNOON.
.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY
249 AM CST SUN FEB 5 2012
FOCUS IN THE EXTENDED CONTINUES TO BE WITH A COLD FRONT THAT IS
PROGGED TO COME THROUGH LATER IN THE WEEK. THE 05.00Z GFS
CONTINUES ITS TREND OF BEING THE FASTEST WITH THIS FEATURE AND
BRINGS IT THROUGH EARLY ON THURSDAY WHILE THE 05.00Z ECMWF IS
STILL SLOWER AND DOES NOT DROP THE FRONT THROUGH UNTIL FRIDAY.
INTRODUCED SOME LIGHT SNOW CHANCES ACROSS NORTH CENTRAL WISCONSIN
WITH THIS FEATURE AS THE GFS HAS BEEN SHOWING SOME POSSIBLE QPF UP
THERE THE PAST FEW RUNS.
OTHERWISE DIFFERENCES CROP UP GOING INTO THE WEEKEND WITH HOW LONG
THE COLD LOW LEVEL AIR REMAINS IN PLACE WITH THE 05.00Z GFS NOW
HOLDING ONTO 850MB TEMPERATURES BELOW -20C INTO THE WEEKEND WHILE
THE 05.00Z ECMWF PUSHING THE COLD AIR RAPIDLY OFF TO THE EAST LOW
LEVEL WARM AIR ADVECTION KICKING IN BY SATURDAY. GIVEN THESE
DISCREPANCIES...CONFIDENCE IS NOT ALL THAT HIGH IN HOW
TEMPERATURES WILL END UP TOWARD THE LATER PORTION OF THE FORECAST
PACKAGE.
&&
.AVIATION...THROUGH 18Z MONDAY
1156 AM CST SUN FEB 5 2012
FORECAST AGAIN DEALS WITH STRATUS. AS OF 18Z SUNDAY...STRATUS
EXISTS ACROSS ABOUT THE SOUTHERN 2/3 OF MINNESOTA AND MOST OF
IOWA...INCLUDING ADJACENT AREAS OF WISCONSIN. CEILINGS RANGE FROM
LIFR TO IFR WITH VISIBILITIES NOW MOSTLY MVFR. DAYTIME MIXING AND
A GRADUAL INCREASING WEST WIND WILL LIKELY ERODE SOME OF THE
STRATUS THROUGH TONIGHT...ESPECIALLY ALONG AND NORTH OF I-94.
FOR THE TAF SITES...THE INCREASING WEST WIND REALLY DOES NOT OCCUR
UNTIL TONIGHT. WITHOUT THE DAYTIME MIXING HELPING OUT...THE
INCREASING WEST WIND MAY NOT BE ENOUGH TO ERODE THE STRATUS. THIS
IS IN AGREEMENT WITH MODEL FORECASTS TOO. THEREFORE...HAVE WENT
MUCH MORE PESSIMISTIC WITH THE AVIATION FORECAST. LOOKS LIKE
AROUND 15-16Z MONDAY...THE CLOUDS SHOULD SCATTER OUT AT THE TAF
SITES DUE TO A COMBINATION OF THE DAYTIME MIXING...THE WESTERLY
WINDS AND AN APPROACHING COLD FRONT FROM THE NORTH. LOOKING
AHEAD...ADDITIONAL LOW STRATUS APPEARS POSSIBLE ONCE THE COLD FRONT
PASSES LATE MONDAY.
IF THE STRATUS OVER SOUTHWEST AND SOUTH CENTRAL MINNESOTA CAN
DISSIPATE MORE THAN EXPECTED...THEN CLEARING WOULD COME INTO
THE TAF SITES EARLIER...PROBABLY MORE 03-04Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
249 AM CST SUN FEB 5 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....HALBACH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1156 AM CST SUN FEB 5 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY
249 AM CST SUN FEB 5 2012
ANOTHER DAY OF TRYING TO FORECAST STRATUS AND TEMPERATURES IS ON
DECK FOR TODAY FOLLOWED BY A COLD FRONT THAT WILL COME THROUGH
MONDAY NIGHT.
ODDLY SITUATED MID LEVEL PATTERN IN PLACE WITH A TROUGH AND TWO
EMBEDDED VORT MAXES EXTENDING WEST FROM THE EASTERN GREAT LAKES
TOWARD NEVADA WITH A CUT OFF RIDGE SET UP ALONG THE US/CANADA
BORDER FROM THE PACIFIC NORTHWEST GOING EAST TOWARD THE DAKOTAS.
AT THE SURFACE...A BROAD RIDGE OF HIGH PRESSURE IS IN PLACE ALONG
THE EASTERN ROCKIES/WESTERN PLAINS WITH A RIDGE AXIS EXTENDING EAST
THROUGH THE UPPER MISSISSIPPI RIVER VALLEY AND GREAT LAKES REGION.
TWO MAIN POCKETS OF STRATUS REMAIN TRAPPED UNDER THE 950-900MB
INVERSION WITH ONE ADVANCING SOUTH-SOUTHEAST ACROSS MINNESOTA AND
ANOTHER OVER THE UPPER PENINSULA OF MICHIGAN AND NORTHEAST
WISCONSIN ADVANCING SOUTH-SOUTHWEST ACROSS EASTERN WISCONSIN.
WHAT HAPPENS WITH THIS CLOUD DECK TODAY IS THE MAIN QUESTION SINCE
IT WILL HAVE A DIRECT IMPACT ON HOW HIGH TEMPERATURES GET ONCE
AGAIN. BASED ON THE 05.06Z HRRR AND RECENT IR SATELLITE
TRENDS...IT LOOKS LIKE THE MINNESOTA STRATUS WILL HOLD ON THROUGH
THE MORNING ACROSS MN/IA WITH THE WISCONSIN STRATUS REACHING THE
MISSISSIPPI RIVER BY LATE MORNING. WHILE SOME HOLES WILL LIKELY
FORM THROUGH THE DAY...WENT A BIT ON THE PESSIMISTIC SIDE FOR
CLOUD COVER TODAY WHICH IN TURN WILL KEEP TEMPERATURES DOWN.
WHERE THE HOLES DO OPEN UP TODAY...HIGHS WILL LIKELY END UP IN THE
LOW TO MID 40S WITH TEMPERATURES IN THE 30S UNDER THE CLOUD DECK.
SOME INCREASING WESTERLY WINDS WILL PUSH DOWN ACROSS NORTHERN
WISCONSIN TODAY AND TONIGHT AND MAY HELP TO MIX OUT SOME OF THIS
LOW STRATUS AND CLEAR SKIES FROM THE NORTH.
THE FOCUS THEN GOES TO A COLD FRONT THAT WILL DROP THROUGH THE
REGION ON MONDAY NIGHT. AHEAD OF IT...WARM AIR ADVECTION AND
INCREASED LOW LEVEL MIXING WILL LEAD TO SUNNY SKIES AND A MILD DAY
WITH HIGHS LIKELY TO REACH THE MID TO UPPER 40S. THE TIMING OF THE
COLD FRONT PASSAGE MONDAY AFTERNOON AND NIGHT IS PRETTY CONSISTENT
BETWEEN THE 05.00Z MODEL SOLUTIONS WITH THE FRONT GETTING SOUTH
OF LA CROSSE AND ROCHESTER BEFORE 00Z TUESDAY AND SOUTH OF THE
WISCONSIN STATE LINE BY 06Z. LOW LEVEL CLOUD COVER WILL BE ON THE
INCREASE AS THE FRONT PASSES WITH THE QUESTION NOW BEING WHETHER
ANY FLURRIES WILL BE POSSIBLE AS THIS FEATURE PASSES. 05.00Z
NAM/GFS SOUNDINGS ARE TRENDING TOWARD HAVING A DEEPER LOW LEVEL
MIXED TEMPERATURE PROFILE WITH A DECENT AMOUNT OF MOISTURE AND
LIFT IN THIS LAYER AVAILABLE TO POSSIBLY PRODUCE SOME SNOWFLAKES
AS THE LAYER COOLS TOWARD -10/-12C. CONFIDENCE IS NOT THAT HIGH AT
THIS POINT TO PUT THESE POSSIBLE FLURRIES IN THE FORECAST...BUT IT
IS AT LEAST SOMETHING TO KEEP TABS ON OVER THE NEXT FEW DAYS.
A BROAD RIDGE OF HIGH PRESSURE WILL MOVE INTO THE UPPER
MISSISSIPPI RIVER VALLEY TUESDAY INTO WEDNESDAY AND WILL KEEP
TEMPERATURES DOWN TOWARD NORMAL INTO MID WEEK.
.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY
249 AM CST SUN FEB 5 2012
FOCUS IN THE EXTENDED CONTINUES TO BE WITH A COLD FRONT THAT IS
PROGGED TO COME THROUGH LATER IN THE WEEK. THE 05.00Z GFS
CONTINUES ITS TREND OF BEING THE FASTEST WITH THIS FEATURE AND
BRINGS IT THROUGH EARLY ON THURSDAY WHILE THE 05.00Z ECMWF IS
STILL SLOWER AND DOES NOT DROP THE FRONT THROUGH UNTIL FRIDAY.
INTRODUCED SOME LIGHT SNOW CHANCES ACROSS NORTH CENTRAL WISCONSIN
WITH THIS FEATURE AS THE GFS HAS BEEN SHOWING SOME POSSIBLE QPF UP
THERE THE PAST FEW RUNS.
OTHERWISE DIFFERENCES CROP UP GOING INTO THE WEEKEND WITH HOW LONG
THE COLD LOW LEVEL AIR REMAINS IN PLACE WITH THE 05.00Z GFS NOW
HOLDING ONTO 850MB TEMPERATURES BELOW -20C INTO THE WEEKEND WHILE
THE 05.00Z ECMWF PUSHING THE COLD AIR RAPIDLY OFF TO THE EAST LOW
LEVEL WARM AIR ADVECTION KICKING IN BY SATURDAY. GIVEN THESE
DISCREPANCIES...CONFIDENCE IS NOT ALL THAT HIGH IN HOW
TEMPERATURES WILL END UP TOWARD THE LATER PORTION OF THE FORECAST
PACKAGE.
&&
.AVIATION...THROUGH 18Z MONDAY
1156 AM CST SUN FEB 5 2012
FORECAST AGAIN DEALS WITH STRATUS. AS OF 18Z SUNDAY...STRATUS
EXISTS ACROSS ABOUT THE SOUTHERN 2/3 OF MINNESOTA AND MOST OF
IOWA...INCLUDING ADJACENT AREAS OF WISCONSIN. CEILINGS RANGE FROM
LIFR TO IFR WITH VISIBILITIES NOW MOSTLY MVFR. DAYTIME MIXING AND
A GRADUAL INCREASING WEST WIND WILL LIKELY ERODE SOME OF THE
STRATUS THROUGH TONIGHT...ESPECIALLY ALONG AND NORTH OF I-94.
FOR THE TAF SITES...THE INCREASING WEST WIND REALLY DOES NOT OCCUR
UNTIL TONIGHT. WITHOUT THE DAYTIME MIXING HELPING OUT...THE
INCREASING WEST WIND MAY NOT BE ENOUGH TO ERODE THE STRATUS. THIS
IS IN AGREEMENT WITH MODEL FORECASTS TOO. THEREFORE...HAVE WENT
MUCH MORE PESSIMISTIC WITH THE AVIATION FORECAST. LOOKS LIKE
AROUND 15-16Z MONDAY...THE CLOUDS SHOULD SCATTER OUT AT THE TAF
SITES DUE TO A COMBINATION OF THE DAYTIME MIXING...THE WESTERLY
WINDS AND AN APPROACHING COLD FRONT FROM THE NORTH. LOOKING
AHEAD...ADDITIONAL LOW STRATUS APPEARS POSSIBLE ONCE THE COLD FRONT
PASSES LATE MONDAY.
IF THE STRATUS OVER SOUTHWEST AND SOUTH CENTRAL MINNESOTA CAN
DISSIPATE MORE THAN EXPECTED...THEN CLEARING WOULD COME INTO
THE TAF SITES EARLIER...PROBABLY MORE 03-04Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
249 AM CST SUN FEB 5 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1142 AM CST SUN FEB 5 2012
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH MONDAY...CLOUD TRENDS ARE THE MAIN FCST
CONCERN.
A S/W TROF BRUSHING PAST TO OUR NE HAS HELPED TO PUSH A WEAK COLD
FRONT THROUGH THE REGION. LOW CLOUDS HAVE INVADED THE NORTHERN
AND EASTERN PARTS OF CWAIN THE WAKE OF THE FRONT...BUT WERE HAVING
A HARD TIME SPREADING INTO CENTRAL WI. A LARGE EXPANSE OF VERY LOW
STRATUS AND FOG WAS ALSO SITUATED OVER MN...AND WAS STARTING TO
CROSS THE WI BORDER.
LOW-LEVEL WINDS ARE EXPECTED TO BECOME WESTERLY BY THIS AFTERNOON...
WHICH SHOULD PUSH THE CURRENT BATCH OF LOW CLOUDS OUT OF GRB CWA.
THIS IS DEPICTED FAIRLY WELL BY THE RUC MODEL. BIG QUESTION IS
WHETHER THE STRATUS OVER MN WILL MAKE A RUN AT THE FORECAST AREA
LATER TODAY INTO TONIGHT. MODELS DO NOT HAVE GOOD HANDLE ON THIS
SCENARIO...AND DON`T OFFER MUCH ASSISTANCE WITH THIS ASPECT OF THE
FCST. WOULD TEND TO BELIEVE THAT THE EASTERN EDGE OF THIS CLOUD
DECK WOULD ERODE DUE TO DAYTIME MIXING...BUT LIKELY REFORM TONIGHT...
AND EDGE INTO NC/C WI. STIFF WESTERLY DOWNSLOPE WINDS (25-30 KTS
AT 925 MB) SHOULD PREVENT THE STRATUS FROM REACHING NE/EC WI.
BASED ON LOW CONFIDENCE...WILL ONLY MENTION PARTLY CLOUDY SKIES
FOR NC/C WI TONIGHT.
A COLD FRONT IS EXPECTED TO SWEEP SOUTHEAST ACROSS THE FORECAST
AREA ON MONDAY...WITH ANOTHER SURGE OF LOW CLOUDS DROPPING INTO
NC/NE WI DURING THE AFTERNOON. NORTH FLOW OFF LAKE SUPERIOR MAY
LEAD TO SOME FLURRIES OR FREEZING DRIZZLE OVER FAR NORTHERN WI
LATE IN THE DAY.
USED A BLEND OF VARIOUS GUIDANCE SETS FOR TEMPERATURES...WHICH
WILL REMAIN WELL ABOVE NORMAL THROUGH MONDAY. THE COLD FRONT WILL
BRING A RETURN TO MORE NORMAL TEMPERATURES BY MONDAY NIGHT/TUESDAY.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY.
MEAN UPPER LEVEL FLOW ACROSS THE REGION SHOULD BE FROM THE
NORTHWEST WITH THE HIGH AMPLITUDE RIDGE WEST OF THE ROCKIES.
PRECIPITATION DURING THE PERIOD SHOULD BE MAINLY FROM LAKE EFFECT
DUE TO LACK OF SIGNIFICANT MOISTURE WITH SYSTEMS MOVING ACROSS THE
UPPER GREAT LAKES REGION. COLDER AIR WILL MAKE ITS WAY INTO THE
REGION BUT TEMPERATURES SHOULD NOT BE MUCH BELOW NORMAL...EVEN ON
THE COLDEST NIGHTS AND DAYS.
HAVE A CHANCE OF SNOW SHOWERS NEAR THE UPPER MICHIGAN BORDER ON
MONDAY NIGHT IN COLD ADVECTION BEHIND A SURFACE COLD FRONT WITH AN
ASSIST FROM A PASSING UPPER LEVEL TROUGH. THIS SHOULD COME TO AN
END EARLY ON TUESDAY AS SURFACE HIGH PRESSURE BUILDS INTO THE
REGION. EXPECT LOWS TO BE NEAR OR A BIT BELOW NORMAL ON TUESDAY
NIGHT WITH THE SURFACE HIGH AND UPPER LEVEL RIDGE OVER THE AREA.
RETURN FLOW AND PLENTY OF SUNSHINE ON WEDNESDAY SHOULD ALLOW
TEMPERATURES TO RISE ABOVE NORMAL ONCE AGAIN...UNTIL ANOTHER SHOT
OF COLDER AIR IMPACTS THE FORECAST AREA BEHIND THE NEXT COLD
FRONT MOVING THROUGH ON THURSDAY. EXPECT BELOW NORMAL TEMPERATURES
ON FRIDAY AND SATURDAY. HAVE LOW END CHANCE OR HIGH END SLIGHT
CHANCE POPS GOING FOR NORTH CENTRAL WISCONSIN AND THE LAKESHORE AT
TIMES THROUGH THE END OF THE FORECAST PERIOD DUE TO POSSIBLE LAKE
EFFECT SNOW SHOWERS.
&&
.AVIATION...MVFR CIGS ACROSS NORTH CENTRAL AND CENTRAL WISCONSIN
NORTH OF KISW WERE ERODING LATE THIS MORNING WITH ONLY A FEW PATCHES
WEST OF KAUW. THESE LOW CLOUDS SHOULD DISAPPEAR EARLY THIS AFTERNOON.
IFR/MVFR CIGS AND VISIBILITIES WERE LURKING ACROSS WESTERN WISCONSIN
AND NORTHEAST IOWA AND HAVE SHOWN A SLOW EASTWARD ADVANCEMENT OVER
THE PAST FEW HOURS. MVFR CIGS ACROSS NORTHEAST WISCONSIN WERE A
LITTLE SLOWER TO CLEAR. SATELLITE IMAGERY WOULD SUGGEST THIS AREA
WOULD GRADUALLY CLEAR FROM WEST TO EAST DURING THE AFTERNOON
HOURS.
MAIN QUESTION FOR TONIGHT IS WHAT WILL HAPPEN TO THE LOW CLOUDS
ACROSS WESTERN WISCONSIN...MINNESOTA AND NORTHEAST IOWA. SATELLITE
IMAGERY INDICATED THAT THE CLOUDS WERE BREAKING UP IN SOME AREAS OF
MINNESOTA. LOW LEVEL WINDS ARE EXPECTED TO TURN TO THE WEST AND
THE THOUGHT IS THAT THE LOW CLOUDS WOULD ADVECT BACK INTO
CENTRAL/NORTH CENTRAL WISCONSIN LATE THIS AFTERNOON OR EARLY
THIS EVENING...THEN ACROSS NORTHEAST WISCONSIN LATER THIS EVENING
INTO THE OVERNIGHT HOURS. THIS THOUGHT WAS SHARED BY THE AVIATION
FORECASTERS AT KMKX/KARX. HOWEVER...NUMERICAL GUIDANCE AND THE
CANADIAN MODEL SUGGEST THE LOW CLOUDS WOULD NOT DEVELOP UNTIL
LATE TONIGHT ACROSS NORTHEAST WISCONSIN AND WOULD NOT DEVELOP AT ALL
ACROSS NORTH CENTRAL WISCONSIN. DECIDED TO GO MORE PESSIMISTIC IN CLOUD
COVER THAN THE NUMERICAL GUIDANCE WOULD SUGGEST. THE NEXT QUESTION
IS WHEN WILL THE LOW CLOUDS BREAK UP. INCREASING WIND SHEAR JUST ABOVE
THE SURFACE MAY PROVIDE ENOUGH MIXING TO BRING DRIER AIR DOWN TO THE
SURFACE AND BREAK UP THE CLOUDS. HAVE LOW CLOUDS EXITING THE AREA LATE
TONIGHT OR EARLY MONDAY MORNING. CURRENT FORECAST IN THE LOW
CLOUDS LEAVING THE AREA IS LOW. ON MONDAY AFTERNOON...THERE IS SOME
POTENTIAL FOR FREEZING DRIZZLE OR FLURRIES MONDAY AFTERNOON...WITH
SOME FLURRIES ACROSS THE NORTH MONDAY NIGHT.
ECKBERG
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
534 AM CST SUN FEB 5 2012
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH MONDAY...CLOUD TRENDS ARE THE MAIN FCST
CONCERN.
A S/W TROF BRUSHING PAST TO OUR NE HAS HELPED TO PUSH A WEAK COLD
FRONT THROUGH THE REGION. LOW CLOUDS HAVE INVADED THE NORTHERN
AND EASTERN PARTS OF CWAIN THE WAKE OF THE FRONT...BUT WERE HAVING
A HARD TIME SPREADING INTO CENTRAL WI. A LARGE EXPANSE OF VERY LOW
STRATUS AND FOG WAS ALSO SITUATED OVER MN...AND WAS STARTING TO
CROSS THE WI BORDER.
LOW-LEVEL WINDS ARE EXPECTED TO BECOME WESTERLY BY THIS AFTERNOON...
WHICH SHOULD PUSH THE CURRENT BATCH OF LOW CLOUDS OUT OF GRB CWA.
THIS IS DEPICTED FAIRLY WELL BY THE RUC MODEL. BIG QUESTION IS
WHETHER THE STRATUS OVER MN WILL MAKE A RUN AT THE FORECAST AREA
LATER TODAY INTO TONIGHT. MODELS DO NOT HAVE GOOD HANDLE ON THIS
SCENARIO...AND DON`T OFFER MUCH ASSISTANCE WITH THIS ASPECT OF THE
FCST. WOULD TEND TO BELIEVE THAT THE EASTERN EDGE OF THIS CLOUD
DECK WOULD ERODE DUE TO DAYTIME MIXING...BUT LIKELY REFORM TONIGHT...
AND EDGE INTO NC/C WI. STIFF WESTERLY DOWNSLOPE WINDS (25-30 KTS
AT 925 MB) SHOULD PREVENT THE STRATUS FROM REACHING NE/EC WI.
BASED ON LOW CONFIDENCE...WILL ONLY MENTION PARTLY CLOUDY SKIES
FOR NC/C WI TONIGHT.
A COLD FRONT IS EXPECTED TO SWEEP SOUTHEAST ACROSS THE FORECAST
AREA ON MONDAY...WITH ANOTHER SURGE OF LOW CLOUDS DROPPING INTO
NC/NE WI DURING THE AFTERNOON. NORTH FLOW OFF LAKE SUPERIOR MAY
LEAD TO SOME FLURRIES OR FREEZING DRIZZLE OVER FAR NORTHERN WI
LATE IN THE DAY.
USED A BLEND OF VARIOUS GUIDANCE SETS FOR TEMPERATURES...WHICH
WILL REMAIN WELL ABOVE NORMAL THROUGH MONDAY. THE COLD FRONT WILL
BRING A RETURN TO MORE NORMAL TEMPERATURES BY MONDAY NIGHT/TUESDAY.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY.
MEAN UPPER LEVEL FLOW ACROSS THE REGION SHOULD BE FROM THE
NORTHWEST WITH THE HIGH AMPLITUDE RIDGE WEST OF THE ROCKIES.
PRECIPITATION DURING THE PERIOD SHOULD BE MAINLY FROM LAKE EFFECT
DUE TO LACK OF SIGNIFICANT MOISTURE WITH SYSTEMS MOVING ACROSS THE
UPPER GREAT LAKES REGION. COLDER AIR WILL MAKE ITS WAY INTO THE
REGION BUT TEMPERATURES SHOULD NOT BE MUCH BELOW NORMAL...EVEN ON
THE COLDEST NIGHTS AND DAYS.
HAVE A CHANCE OF SNOW SHOWERS NEAR THE UPPER MICHIGAN BORDER ON
MONDAY NIGHT IN COLD ADVECTION BEHIND A SURFACE COLD FRONT WITH AN
ASSIST FROM A PASSING UPPER LEVEL TROUGH. THIS SHOULD COME TO AN
END EARLY ON TUESDAY AS SURFACE HIGH PRESSURE BUILDS INTO THE
REGION. EXPECT LOWS TO BE NEAR OR A BIT BELOW NORMAL ON TUESDAY
NIGHT WITH THE SURFACE HIGH AND UPPER LEVEL RIDGE OVER THE AREA.
RETURN FLOW AND PLENTY OF SUNSHINE ON WEDNESDAY SHOULD ALLOW
TEMPERATURES TO RISE ABOVE NORMAL ONCE AGAIN...UNTIL ANOTHER SHOT
OF COLDER AIR IMPACTS THE FORECAST AREA BEHIND THE NEXT COLD
FRONT MOVING THROUGH ON THURSDAY. EXPECT BELOW NORMAL TEMPERATURES
ON FRIDAY AND SATURDAY. HAVE LOW END CHANCE OR HIGH END SLIGHT
CHANCE POPS GOING FOR NORTH CENTRAL WISCONSIN AND THE LAKESHORE AT
TIMES THROUGH THE END OF THE FORECAST PERIOD DUE TO POSSIBLE LAKE
EFFECT SNOW SHOWERS.
&&
.AVIATION...MVFR/IFR CIGS HAVE PUSHED INTO NORTHERN AND EASTERN WI
EARLY THIS MORNING. SOME PATCHY FOG HAD DEVELOPED IN CENTRAL WI...
WHERE SKIES WERE STILL CLEAR. EXPECT THE STRATUS TO EVENTUALLY
PULL OUT TO THE EAST BY LATE MORNING OR EARLY AFTERNOON...AS LOW-
LEVEL WINDS BECOME WESTERLY. HOWEVER...WIDESPREAD IFR/LIFR CIGS
OVER MN AND FAR WSTRN WI COULD MAKE A RUN AT NC/C WI LATER TODAY
INTO TONIGHT. CONFIDENCE IS LOW IN HOW THIS WILL PLAY OUT...SO
WILL JUST MENTION SCT LOW CLOUDS AT RHI/AUW/CWA TONIGHT.
DOWNSLOPING WEST WINDS SHOULD KEEP THE LOW CLOUDS FROM FORMING
OVER NE/EC WI TONIGHT. WEST-NORTHWEST WINDS INCREASING TO 35 KTS
AT 1000-1500 FT AGL WILL RESULT IN SOME LLWS...STARTING THIS EVG.
KIECKBUSCH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
528 AM CST SUN FEB 5 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY
249 AM CST SUN FEB 5 2012
ANOTHER DAY OF TRYING TO FORECAST STRATUS AND TEMPERATURES IS ON
DECK FOR TODAY FOLLOWED BY A COLD FRONT THAT WILL COME THROUGH
MONDAY NIGHT.
ODDLY SITUATED MID LEVEL PATTERN IN PLACE WITH A TROUGH AND TWO
EMBEDDED VORT MAXES EXTENDING WEST FROM THE EASTERN GREAT LAKES
TOWARD NEVADA WITH A CUT OFF RIDGE SET UP ALONG THE US/CANADA
BORDER FROM THE PACIFIC NORTHWEST GOING EAST TOWARD THE DAKOTAS.
AT THE SURFACE...A BROAD RIDGE OF HIGH PRESSURE IS IN PLACE ALONG
THE EASTERN ROCKIES/WESTERN PLAINS WITH A RIDGE AXIS EXTENDING EAST
THROUGH THE UPPER MISSISSIPPI RIVER VALLEY AND GREAT LAKES REGION.
TWO MAIN POCKETS OF STRATUS REMAIN TRAPPED UNDER THE 950-900MB
INVERSION WITH ONE ADVANCING SOUTH-SOUTHEAST ACROSS MINNESOTA AND
ANOTHER OVER THE UPPER PENINSULA OF MICHIGAN AND NORTHEAST
WISCONSIN ADVANCING SOUTH-SOUTHWEST ACROSS EASTERN WISCONSIN.
WHAT HAPPENS WITH THIS CLOUD DECK TODAY IS THE MAIN QUESTION SINCE
IT WILL HAVE A DIRECT IMPACT ON HOW HIGH TEMPERATURES GET ONCE
AGAIN. BASED ON THE 05.06Z HRRR AND RECENT IR SATELLITE
TRENDS...IT LOOKS LIKE THE MINNESOTA STRATUS WILL HOLD ON THROUGH
THE MORNING ACROSS MN/IA WITH THE WISCONSIN STRATUS REACHING THE
MISSISSIPPI RIVER BY LATE MORNING. WHILE SOME HOLES WILL LIKELY
FORM THROUGH THE DAY...WENT A BIT ON THE PESSIMISTIC SIDE FOR
CLOUD COVER TODAY WHICH IN TURN WILL KEEP TEMPERATURES DOWN.
WHERE THE HOLES DO OPEN UP TODAY...HIGHS WILL LIKELY END UP IN THE
LOW TO MID 40S WITH TEMPERATURES IN THE 30S UNDER THE CLOUD DECK.
SOME INCREASING WESTERLY WINDS WILL PUSH DOWN ACROSS NORTHERN
WISCONSIN TODAY AND TONIGHT AND MAY HELP TO MIX OUT SOME OF THIS
LOW STRATUS AND CLEAR SKIES FROM THE NORTH.
THE FOCUS THEN GOES TO A COLD FRONT THAT WILL DROP THROUGH THE
REGION ON MONDAY NIGHT. AHEAD OF IT...WARM AIR ADVECTION AND
INCREASED LOW LEVEL MIXING WILL LEAD TO SUNNY SKIES AND A MILD DAY
WITH HIGHS LIKELY TO REACH THE MID TO UPPER 40S. THE TIMING OF THE
COLD FRONT PASSAGE MONDAY AFTERNOON AND NIGHT IS PRETTY CONSISTENT
BETWEEN THE 05.00Z MODEL SOLUTIONS WITH THE FRONT GETTING SOUTH
OF LA CROSSE AND ROCHESTER BEFORE 00Z TUESDAY AND SOUTH OF THE
WISCONSIN STATE LINE BY 06Z. LOW LEVEL CLOUD COVER WILL BE ON THE
INCREASE AS THE FRONT PASSES WITH THE QUESTION NOW BEING WHETHER
ANY FLURRIES WILL BE POSSIBLE AS THIS FEATURE PASSES. 05.00Z
NAM/GFS SOUNDINGS ARE TRENDING TOWARD HAVING A DEEPER LOW LEVEL
MIXED TEMPERATURE PROFILE WITH A DECENT AMOUNT OF MOISTURE AND
LIFT IN THIS LAYER AVAILABLE TO POSSIBLY PRODUCE SOME SNOWFLAKES
AS THE LAYER COOLS TOWARD -10/-12C. CONFIDENCE IS NOT THAT HIGH AT
THIS POINT TO PUT THESE POSSIBLE FLURRIES IN THE FORECAST...BUT IT
IS AT LEAST SOMETHING TO KEEP TABS ON OVER THE NEXT FEW DAYS.
A BROAD RIDGE OF HIGH PRESSURE WILL MOVE INTO THE UPPER
MISSISSIPPI RIVER VALLEY TUESDAY INTO WEDNESDAY AND WILL KEEP
TEMPERATURES DOWN TOWARD NORMAL INTO MID WEEK.
.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY
249 AM CST SUN FEB 5 2012
FOCUS IN THE EXTENDED CONTINUES TO BE WITH A COLD FRONT THAT IS
PROGGED TO COME THROUGH LATER IN THE WEEK. THE 05.00Z GFS
CONTINUES ITS TREND OF BEING THE FASTEST WITH THIS FEATURE AND
BRINGS IT THROUGH EARLY ON THURSDAY WHILE THE 05.00Z ECMWF IS
STILL SLOWER AND DOES NOT DROP THE FRONT THROUGH UNTIL FRIDAY.
INTRODUCED SOME LIGHT SNOW CHANCES ACROSS NORTH CENTRAL WISCONSIN
WITH THIS FEATURE AS THE GFS HAS BEEN SHOWING SOME POSSIBLE QPF UP
THERE THE PAST FEW RUNS.
OTHERWISE DIFFERENCES CROP UP GOING INTO THE WEEKEND WITH HOW LONG
THE COLD LOW LEVEL AIR REMAINS IN PLACE WITH THE 05.00Z GFS NOW
HOLDING ONTO 850MB TEMPERATURES BELOW -20C INTO THE WEEKEND WHILE
THE 05.00Z ECMWF PUSHING THE COLD AIR RAPIDLY OFF TO THE EAST LOW
LEVEL WARM AIR ADVECTION KICKING IN BY SATURDAY. GIVEN THESE
DISCREPANCIES...CONFIDENCE IS NOT ALL THAT HIGH IN HOW
TEMPERATURES WILL END UP TOWARD THE LATER PORTION OF THE FORECAST
PACKAGE.
&&
.AVIATION...TODAY AND TONIGHT
527 AM CST SUN FEB 5 2012
LOW STRATUS WILL PRODUCE LIFR CONDITIONS AT KRST AND IFR
CONDITIONS AT KLSE THROUGH MUCH OF THIS MORNING. PLAN ON CLOUD
BASES AROUND 400 FT AT KRST AND 900 FT AT KLSE. IN
ADDITION...VISIBILITIES WILL RANGE FROM 3 TO 5 SM IN BR. LOOK FOR
CONDITIONS TO GRADUALLY IMPROVE TO VFR THIS AFTERNOON AS THE
SURFACE RIDGE SLIDES SOUTH OF THE REGION AND THE PRESSURE GRADIENT
TIGHTENS AHEAD OF AN APPROACHING COLD FRONT ACROSS SOUTHERN
MANITOBA/ONTARIO. LOOK FOR WINDS TO BACK TO THE WEST/SOUTHWEST
TONIGHT...WITH SPEEDS OF 6 TO 10 KTS EXPECTED. GUIDANCE IS
SUGGESTING AREAS OF BR TONIGHT AT KRST. THIS SEEMS REASONABLE
GIVEN THE AIRMASS IN PLACE...SO HAVE DECIDED TO MAINTAIN 5 SM BR
IN THE FORECAST THIS EVENING...STARTING AT 04Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
249 AM CST SUN FEB 5 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION.....WETENKAMP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
404 AM CST SUN FEB 5 2012
.SHORT TERM...TODAY THROUGH MONDAY...CLOUD TRENDS ARE THE MAIN FCST
CONCERN.
A S/W TROF BRUSHING PAST TO OUR NE HAS HELPED TO PUSH A WEAK COLD
FRONT THROUGH THE REGION. LOW CLOUDS HAVE INVADED THE NORTHERN
AND EASTERN PARTS OF CWAIN THE WAKE OF THE FRONT...BUT WERE HAVING
A HARD TIME SPREADING INTO CENTRAL WI. A LARGE EXPANSE OF VERY LOW
STRATUS AND FOG WAS ALSO SITUATED OVER MN...AND WAS STARTING TO
CROSS THE WI BORDER.
LOW-LEVEL WINDS ARE EXPECTED TO BECOME WESTERLY BY THIS AFTERNOON...
WHICH SHOULD PUSH THE CURRENT BATCH OF LOW CLOUDS OUT OF GRB CWA.
THIS IS DEPICTED FAIRLY WELL BY THE RUC MODEL. BIG QUESTION IS
WHETHER THE STRATUS OVER MN WILL MAKE A RUN AT THE FORECAST AREA
LATER TODAY INTO TONIGHT. MODELS DO NOT HAVE GOOD HANDLE ON THIS
SCENARIO...AND DON`T OFFER MUCH ASSISTANCE WITH THIS ASPECT OF THE
FCST. WOULD TEND TO BELIEVE THAT THE EASTERN EDGE OF THIS CLOUD
DECK WOULD ERODE DUE TO DAYTIME MIXING...BUT LIKELY REFORM TONIGHT...
AND EDGE INTO NC/C WI. STIFF WESTERLY DOWNSLOPE WINDS (25-30 KTS
AT 925 MB) SHOULD PREVENT THE STRATUS FROM REACHING NE/EC WI.
BASED ON LOW CONFIDENCE...WILL ONLY MENTION PARTLY CLOUDY SKIES
FOR NC/C WI TONIGHT.
A COLD FRONT IS EXPECTED TO SWEEP SOUTHEAST ACROSS THE FORECAST
AREA ON MONDAY...WITH ANOTHER SURGE OF LOW CLOUDS DROPPING INTO
NC/NE WI DURING THE AFTERNOON. NORTH FLOW OFF LAKE SUPERIOR MAY
LEAD TO SOME FLURRIES OR FREEZING DRIZZLE OVER FAR NORTHERN WI
LATE IN THE DAY.
USED A BLEND OF VARIOUS GUIDANCE SETS FOR TEMPERATURES...WHICH
WILL REMAIN WELL ABOVE NORMAL THROUGH MONDAY. THE COLD FRONT WILL
BRING A RETURN TO MORE NORMAL TEMPERATURES BY MONDAY NIGHT/TUESDAY.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY.
MEAN UPPER LEVEL FLOW ACROSS THE REGION SHOULD BE FROM THE
NORTHWEST WITH THE HIGH AMPLITUDE RIDGE WEST OF THE ROCKIES.
PRECIPITATION DURING THE PERIOD SHOULD BE MAINLY FROM LAKE EFFECT
DUE TO LACK OF SIGNIFICANT MOISTURE WITH SYSTEMS MOVING ACROSS THE
UPPER GREAT LAKES REGION. COLDER AIR WILL MAKE ITS WAY INTO THE
REGION BUT TEMPERATURES SHOULD NOT BE MUCH BELOW NORMAL...EVEN ON
THE COLDEST NIGHTS AND DAYS.
HAVE A CHANCE OF SNOW SHOWERS NEAR THE UPPER MICHIGAN BORDER ON
MONDAY NIGHT IN COLD ADVECTION BEHIND A SURFACE COLD FRONT WITH AN
ASSIST FROM A PASSING UPPER LEVEL TROUGH. THIS SHOULD COME TO AN
END EARLY ON TUESDAY AS SURFACE HIGH PRESSURE BUILDS INTO THE
REGION. EXPECT LOWS TO BE NEAR OR A BIT BELOW NORMAL ON TUESDAY
NIGHT WITH THE SURFACE HIGH AND UPPER LEVEL RIDGE OVER THE AREA.
RETURN FLOW AND PLENTY OF SUNSHINE ON WEDNESDAY SHOULD ALLOW
TEMPERATURES TO RISE ABOVE NORMAL ONCE AGAIN...UNTIL ANOTHER SHOT
OF COLDER AIR IMPACTS THE FORECAST AREA BEHIND THE NEXT COLD
FRONT MOVING THROUGH ON THURSDAY. EXPECT BELOW NORMAL TEMPERATURES
ON FRIDAY AND SATURDAY. HAVE LOW END CHANCE OR HIGH END SLIGHT
CHANCE POPS GOING FOR NORTH CENTRAL WISCONSIN AND THE LAKESHORE AT
TIMES THROUGH THE END OF THE FORECAST PERIOD DUE TO POSSIBLE LAKE
EFFECT SNOW SHOWERS.
&&
.AVIATION...MVFR/IFR CIGS HAVE PUSHED INTO NORTHERN AND EASTERN WI
EARLY THIS MORNING. SOME PATCHY FOG JUST STARTING TO DEVELOP IN CENTRAL
WI...WHERE SKIES ARE STILL CLEAR. EXPECT THE STRATUS TO EVENTUALLY
PULL OUT TO THE EAST BY MIDDAY OR EARLY AFTERNOON...AS LOW-LEVEL
WINDS BECOME WESTERLY. HOWEVER...WIDESPREAD IFR/LIFR CIGS OVER MN
AND FAR WSTRN WI COULD MAKE A RUN AT NC/C WI LATER TODAY INTO
TONIGHT. CONFIDENCE IS LOW IN HOW THIS WILL PLAY OUT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
KIECKBUSCH/MG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
249 AM CST SUN FEB 5 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY
249 AM CST SUN FEB 5 2012
ANOTHER DAY OF TRYING TO FORECAST STRATUS AND TEMPERATURES IS ON
DECK FOR TODAY FOLLOWED BY A COLD FRONT THAT WILL COME THROUGH
MONDAY NIGHT.
ODDLY SITUATED MID LEVEL PATTERN IN PLACE WITH A TROUGH AND TWO
EMBEDDED VORT MAXES EXTENDING WEST FROM THE EASTERN GREAT LAKES
TOWARD NEVADA WITH A CUT OFF RIDGE SET UP ALONG THE US/CANADA
BORDER FROM THE PACIFIC NORTHWEST GOING EAST TOWARD THE DAKOTAS.
AT THE SURFACE...A BROAD RIDGE OF HIGH PRESSURE IS IN PLACE ALONG
THE EASTERN ROCKIES/WESTERN PLAINS WITH A RIDGE AXIS EXTENDING EAST
THROUGH THE UPPER MISSISSIPPI RIVER VALLEY AND GREAT LAKES REGION.
TWO MAIN POCKETS OF STRATUS REMAIN TRAPPED UNDER THE 950-900MB
INVERSION WITH ONE ADVANCING SOUTH-SOUTHEAST ACROSS MINNESOTA AND
ANOTHER OVER THE UPPER PENINSULA OF MICHIGAN AND NORTHEAST
WISCONSIN ADVANCING SOUTH-SOUTHWEST ACROSS EASTERN WISCONSIN.
WHAT HAPPENS WITH THIS CLOUD DECK TODAY IS THE MAIN QUESTION SINCE
IT WILL HAVE A DIRECT IMPACT ON HOW HIGH TEMPERATURES GET ONCE
AGAIN. BASED ON THE 05.06Z HRRR AND RECENT IR SATELLITE
TRENDS...IT LOOKS LIKE THE MINNESOTA STRATUS WILL HOLD ON THROUGH
THE MORNING ACROSS MN/IA WITH THE WISCONSIN STRATUS REACHING THE
MISSISSIPPI RIVER BY LATE MORNING. WHILE SOME HOLES WILL LIKELY
FORM THROUGH THE DAY...WENT A BIT ON THE PESSIMISTIC SIDE FOR
CLOUD COVER TODAY WHICH IN TURN WILL KEEP TEMPERATURES DOWN.
WHERE THE HOLES DO OPEN UP TODAY...HIGHS WILL LIKELY END UP IN THE
LOW TO MID 40S WITH TEMPERATURES IN THE 30S UNDER THE CLOUD DECK.
SOME INCREASING WESTERLY WINDS WILL PUSH DOWN ACROSS NORTHERN
WISCONSIN TODAY AND TONIGHT AND MAY HELP TO MIX OUT SOME OF THIS
LOW STRATUS AND CLEAR SKIES FROM THE NORTH.
THE FOCUS THEN GOES TO A COLD FRONT THAT WILL DROP THROUGH THE
REGION ON MONDAY NIGHT. AHEAD OF IT...WARM AIR ADVECTION AND
INCREASED LOW LEVEL MIXING WILL LEAD TO SUNNY SKIES AND A MILD DAY
WITH HIGHS LIKELY TO REACH THE MID TO UPPER 40S. THE TIMING OF THE
COLD FRONT PASSAGE MONDAY AFTERNOON AND NIGHT IS PRETTY CONSISTENT
BETWEEN THE 05.00Z MODEL SOLUTIONS WITH THE FRONT GETTING SOUTH
OF LA CROSSE AND ROCHESTER BEFORE 00Z TUESDAY AND SOUTH OF THE
WISCONSIN STATE LINE BY 06Z. LOW LEVEL CLOUD COVER WILL BE ON THE
INCREASE AS THE FRONT PASSES WITH THE QUESTION NOW BEING WHETHER
ANY FLURRIES WILL BE POSSIBLE AS THIS FEATURE PASSES. 05.00Z
NAM/GFS SOUNDINGS ARE TRENDING TOWARD HAVING A DEEPER LOW LEVEL
MIXED TEMPERATURE PROFILE WITH A DECENT AMOUNT OF MOISTURE AND
LIFT IN THIS LAYER AVAILABLE TO POSSIBLY PRODUCE SOME SNOWFLAKES
AS THE LAYER COOLS TOWARD -10/-12C. CONFIDENCE IS NOT THAT HIGH AT
THIS POINT TO PUT THESE POSSIBLE FLURRIES IN THE FORECAST...BUT IT
IS AT LEAST SOMETHING TO KEEP TABS ON OVER THE NEXT FEW DAYS.
A BROAD RIDGE OF HIGH PRESSURE WILL MOVE INTO THE UPPER
MISSISSIPPI RIVER VALLEY TUESDAY INTO WEDNESDAY AND WILL KEEP
TEMPERATURES DOWN TOWARD NORMAL INTO MID WEEK.
.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY
249 AM CST SUN FEB 5 2012
FOCUS IN THE EXTENDED CONTINUES TO BE WITH A COLD FRONT THAT IS
PROGGED TO COME THROUGH LATER IN THE WEEK. THE 05.00Z GFS
CONTINUES ITS TREND OF BEING THE FASTEST WITH THIS FEATURE AND
BRINGS IT THROUGH EARLY ON THURSDAY WHILE THE 05.00Z ECMWF IS
STILL SLOWER AND DOES NOT DROP THE FRONT THROUGH UNTIL FRIDAY.
INTRODUCED SOME LIGHT SNOW CHANCES ACROSS NORTH CENTRAL WISCONSIN
WITH THIS FEATURE AS THE GFS HAS BEEN SHOWING SOME POSSIBLE QPF UP
THERE THE PAST FEW RUNS.
OTHERWISE DIFFERENCES CROP UP GOING INTO THE WEEKEND WITH HOW LONG
THE COLD LOW LEVEL AIR REMAINS IN PLACE WITH THE 05.00Z GFS NOW
HOLDING ONTO 850MB TEMPERATURES BELOW -20C INTO THE WEEKEND WHILE
THE 05.00Z ECMWF PUSHING THE COLD AIR RAPIDLY OFF TO THE EAST LOW
LEVEL WARM AIR ADVECTION KICKING IN BY SATURDAY. GIVEN THESE
DISCREPANCIES...CONFIDENCE IS NOT ALL THAT HIGH IN HOW
TEMPERATURES WILL END UP TOWARD THE LATER PORTION OF THE FORECAST
PACKAGE.
&&
.AVIATION...THROUGH 06Z MONDAY
1133 PM CST SAT FEB 4 2012
A LARGE AREA OF STRATUS OVER MINNESOTA WAS PUSHING
SOUTHEAST...WITH THE LEADING EDGE EXTENDING FROM NEAR KONA...TO
KCCY. QUITE A BIT OF REPORTS OF CEILINGS IN THE LIFR CATEGORY
UNDER THE STRATUS AT 05Z. VISIBILITIES ON THE OTHER HAND WERE
RANGING FROM 1/2SM TO 5SM. 05.04Z RUC 975MB RELATIVE HUMIDITY PROG
SHOWS THIS STRATUS TO CONTINUE TO ADVECT EASTWARD BLANKETING BOTH
TAF SITES THROUGHOUT THE NIGHT. KLSE WILL LIKELY SEE THE STRATUS
BETWEEN 06Z-07Z. EXPECT LIFR CONDITIONS AT KRST AND IFR CONDITIONS AT
KLSE THROUGH AROUND 16Z. BY THAT TIME BOTH THE 05.04Z RUC AND
05.00Z NAM BUFKIT SOUNDINGS SHOW ENOUGH MIXING TO SCATTER OUT THE
CLOUDS. VFR CONDITIONS WILL THEN PREVAIL INTO THE EVENING HOURS.
COULD SEE SOME MVFR VISIBILITIES DEVELOP BETWEEN 04Z-06Z SUNDAY AS
COLUMN COOLS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
249 AM CST SUN FEB 5 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1053 PM CST SAT FEB 4 2012
.UPDATE...
EXPECT SKIES TO REMAIN CLEAR TONIGHT WITH SOME PATCHY FOG DURING
THE EARLY MORNING HOURS.
WILL HAVE TO WATCH THE STRATOCUMULUS SHIELD THAT IS PUSHING SOUTH
ACROSS NORTHERN LAKE MICHIGAN. THE HRRR TAKES THESE CLOUDS INTO
MUCH OF SOUTHERN WISCONSIN AFTER SUNRISE.
&&
.AVIATION/06Z TAFS/...
EXPECT CLEAR SKIES EARLY THIS MORNING WITH AREAS OF MVFR VSBYS IS
FOG AND SOME PATCHY IFR VSBYS AROUND SUNRISE.
MAIN PROBLEM IS WITH MVFR STRATOCUMULUS DECK PUSHING SOUTH ACROSS
NORTHERN LAKE MICHIGAN BEHIND THE 500 MB TROF MOVING ACROSS THE
GREAT LAKES. THE HRRR AND RUC TAKE THESE CLOUDS INTO MUCH OF
SOUTHERN WISCONSIN. NAM/GFS DO NOT. WILL LEAN TOWARD THE HIGH RES
MODELS SINCE THE HRRR HAS BEEN DOING A GOOD JOB WITH THE FIRST 4
HOURS OF THE FORECAST IN THE SOUTHERN MOVEMENT.
WILL REFLECT THIS IN THE 06Z TAFS.
&&
.PREV DISCUSSION... /ISSUED 226 PM CST SAT FEB 4 2012/
TONIGHT AND SUNDAY...FORECAST CONFIDENCE MEDIUM.
INFLUENCE OF HIGH PRESSURE ACROSS THE NORTHERN AND CENTRAL PLAINS
DURING THIS TIME WILL BRING QUIET WEATHER TO THE AREA. SKIES SHOULD
REMAIN MOSTLY CLEAR ACROSS THE AREA TONIGHT AND SUNDAY...WITH DRY
AIRMASS IN PLACE. RUC/NAM FORECAST SOUNDINGS TRYING TO SHOW A LOW
STRATUS CLOUD DECK FORMING TONIGHT...BUT THESE MODELS HAVE BEEN
OVERFORECASTING THESE DECKS ALL WINTER AND DO NOT BUY IT WITH DRY
AIR IN PLACE.
THERE MAY BE SOME LOW CLOUDS THAT DRIFT INTO THE FAR WESTERN
COUNTIES LATER TONIGHT...ASSOCIATED WITH LOW CLOUD DECK TO THE
WEST. SOME LOW STRATUS MAY ALSO TRY TO WORK INTO THE FAR NORTHEAST
COUNTIES LATER TONIGHT...BUT MOST SHOULD REMAIN TO THE NORTHEAST.
TEMPERATURES TONIGHT SHOULD FALL INTO THE 20S ACROSS THE AREA WITH
MOSTLY CLEAR SKIES AND RELATIVELY LIGHT WINDS. HIGHS SUNDAY SHOULD
RISE INTO THE LOWER 40S AT LEAST...GIVEN SIMILAR CONDITIONS TO
TODAY. WINDS TURNING WEST SUNDAY AFTERNOON WITH LITTLE TO NO
SNOWPACK MAY HELP TEMPERATURES RISE EVEN MORE...INTO THE MID 40S.
SUNDAY NIGHT AND MONDAY...FORECAST CONFIDENCE IS HIGH.
THE SURFACE RIDGE AXIS BEGINS TO SHIFT SOUTH IN RESPONSE TO A
TROF/COLD FRONT DROPPING DUE SOUTH OUT OF CANADA. THE TROF AXIS
WILL STAY NORTH OF THE CWA THROUGH MONDAY AFTERNOON WITH A
DEVELOPING WESTERLY FLOW AHEAD OF IT BRINGING IN A DECENT THERMAL
RIDGE. ANY CLOUDS WITH THE CANADIAN SYSTEM SHOULD BE MAINLY POST
FRONTAL...SO PLENTY OF SUNSHINE EXPECTED ON MONDAY. GIVEN THE LACK
OF DEEP SNOW COVER OVER MUCH OF THE CWA...WE/RE STILL LOOKING AT
TEMPS ABOVE MOS GUIDANCE. CURRENT VISIBLE SATELLITE IMAGE SHOWS
THE FUZZY WHITE INDICATIONS OF A LIGHT SNOW COVER ROUGHLY WEST OF
A LINE STRETCHING FROM FOND DU LAC TO DARLINGTON. THERE IS STILL
OFFICIALLY 1 INCH ON THE GROUND AT THE MADISON AIRPORT. NOT ENOUGH
TO REALLY HOLD BACK THOSE TEMPS.
MONDAY NIGHT AND TUESDAY...FORECAST CONFIDENCE IS MEDIUM.
THE COLD FRONT COMES THROUGH EARLY MONDAY NIGHT WITH ALL THE
MODELS SHOWING A DECENT AMOUNT OF LOW LEVEL MOISTURE/CLOUD COVER
IN IT/S WAKE. THE NAM GENERATES SOME LIGHT QPF LATE MONDAY NIGHT
AND TUESDAY AS IT SNEAKS IN SOME DEEPER MOISTURE WITH AN ARRIVING
UPPER LEVEL SHORTWAVE SHORTLY AFTER THE FRONT MOVES THROUGH. THE
NAM IS THE FARTHEST NORTH WITH THIS FEATURE AND DEFINITELY THE
MOST GENEROUS WITH THE MOISTURE. AT THIS POINT...WILL LEAVE ANY
SNOW MENTION OUT OF THE FORECAST...EXCEPT FOR NEAR LAKE MICHIGAN
IN THE FAR SOUTHEAST. HERE...IT LOOKS LIKE THE DEVELOPING NORTHEAST
FLOW COMBINED WITH DELTA/TS AROUND 13-14 WILL BE ENOUGH TO
GENERATE SOME LAKE EFFECT SNOW SHOWERS ON TUESDAY. THE INVERSION
IS LIMITED AT ONLY 5 TO MAYBE 6KFT...SO NOTHING MAJOR. LOOKING AT
LESS THAN AN INCH.
WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM.
HIGH PRESSURE SETTLES BACK IN FOR QUIET BUT COOLER WEATHER.
THURSDAY THROUGH SATURDAY...FORECAST CONFIDENCE IS MEDIUM.
THE GFS AND THE ECMWF HAVE ANOTHER COLD FRONT SWEEPING THROUGH
SOMETIME ON THURSDAY...TIMING IS A BIT OUT OF SYNC. THIS IS WITH A
LOW PRESSURE SYSTEM TRACKING ACROSS THE LAKE SUPERIOR AREA. RIGHT
NOW...MOISTURE LOOKS QUESTIONABLE FOR ANY PRECIP...SO THINGS ARE
DRY FOR NOW. BUT SMALL POPS MAY END UP BEING INTRODUCED LATER ON
FOR THIS SYSTEM. THIS ALSO SIGNALS ANOTHER SHOT OF COLD AIR...THIS
ONE CERTAINLY MORE ARCTIC LIKE. COLD HIGH PRESSURE BUILDS IN
QUICKLY BY THURSDAY NIGHT. HIGHS LATE NEXT WEEK WILL ONLY BE IN
THE 20S...BUT THIS IS ACTUALLY A MORE NORMAL HIGH FOR THIS TIME OF
YEAR. SO...OUR ARCTIC BLAST WILL ONLY PUSH TEMPS DOWN TO NORMAL
LEVELS. WHAT A WINTER.
AVIATION/00Z TAFS/...
ANY LINGERING LAKE EFFECT CLOUDS SHOULD MIX OUT AT MILWAUKEE AND
KENOSHA BY LATE THIS AFTERNOON...AS LOW LEVEL WINDS BACK TO THE
NORTH. ONLY SCATTERED CLOUDS AT WORST ARE EXPECTED.
INFLUENCE OF HIGH PRESSURE TO THE WEST OF THE AREA TONIGHT AND
SUNDAY WILL BRING VFR CONDITIONS WITH MOSTLY CLEAR SKIES. LIGHT
NORTHWEST WINDS TONIGHT WILL BECOME WEST BY SUNDAY AFTERNOON.
MARINE...
BRISK NORTHEAST WINDS AND HIGH WAVES ARE POSSIBLE ON TUESDAY...IN
THE WAKE OF A COLD FRONTAL PASSAGE. A TIGHT PRESSURE GRADIENT BEHIND
THE FRONT WOULD COMBINE WITH GOOD LOW LEVEL MIXING OF WINDS TO BRING
THESE CONDITIONS. THE HIGH WAVES MAY LINGER INTO TUESDAY NIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...HENTZ
TONIGHT/SUNDAY AND AVIATION/MARINE...WOOD
SUNDAY NIGHT THROUGH SATURDAY...DAVIS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
330 AM EST Tue Feb 7 2012
.SYNOPSIS...
07Z water vapor and H4 RUC analysis shows a complex and disorganized
upper level pattern across the CONUS this morning. Southern stream
flow extends northeastward from central Mexico to the SE States.
Associated with this flow, abundant mid/upper level moisture and
resulting cloudiness is streaming across our skies. One subtle
shortwave impulse is noted embedded within the flow over the
north-central Gulf of Mexico. Weak synoptic lift associated with
this energy is approaching our region from the west with some
enhancement/cooling cloud tops noted on IR satellite imagery. This
lift may be just enough to support a few light showers/sprinkles
this morning across mainly the SE half of the area.
At the surface, forecast area resides between 1025mb high pressure
over the western TN valley, and a decaying frontal boundary over the
central FL peninsula. Resulting gradient is supplying the area with
a light NE low level flow, and an expanding area of lower level
stratus.
&&
.SHORT TERM (TODAY THROUGH THURSDAY)...
Today,
Weak shortwave impulse mentioned above in the synopsis will approach
and cross the forecast area through the early afternoon hours. Swath
of deep layer synoptic support/QG-forcing ahead of this impulse will
also overspread the area and may be sufficient to support a few
widely sct light showers/sprinkles. Best chances of seeing a brief
shower will be south and east of a line from Panama City to
Tallahassee, and Valdosta. GFS/SREF are most aggressive with the
shower activity, while the higher resolution CAM models are barely
forcing any activity at all. Either way, any showers will be of very
low impact, and likely barely enough to wet the ground. Large scale
forcing will be quickly exiting to the east by mid-afternoon, and
will end any slight shower chances in the grids. Likely will see a
scattering of sunny breaks, especially during the afternoon, but
overall will highlight a mostly cloudy forecast with high temps into
the upper 60s/lower 70s.
Tonight,
Upper level energy will eject eastward from the Central Plains to
the TN valley dragging an associated surface front across the lower
MS valley and toward our western borders. Current timing looks to
bring the front into our SE AL/FL panhandle zones around sunrise.
Good model agreement in keeping any significant synoptic forcing to
our north, and this being a dry frontal passage for our area. Low
temperatures will be seasonable ranging from the middle 40s to lower
50s.
Wednesday/Wednesday Night,
Upper level shortwave will pivot eastward and off the mid-Atlantic
coast dragging the surface front to our east by the end of the day.
Not a big supply of colder air to work with in the wake of this
front, and only looking for modest CAA. In fact, good diurnal mixing
behind the front will likely make up for much of the CAA, and still
anticipate high temperatures to reach the upper 60s to lower 70s.
Clearing skies and drier low levels will allow temperatures to reach
the upper 30s and lower 40s across many inland areas by sunrise
Thursday morning. At it looks now, with the high center well to our
NW, the gradient will hold tight and prevent any significant
radiational cooling. With this in mind do not presently expect any
threat of freezing temps (or even frost) Thursday morning.
Thursday,
Dry, pleasant, and seasonable weather appears on tap as surface high
pressure dominates the deep south. Grids will show an increase in
high level clouds late in the day as the ECMWF/GFS forecast a
series of mid-level southern stream impulses ejecting eastward along
the northern Gulf Coast.
&&
.LONG TERM (FRIDAY THROUGH NEXT TUESDAY)...
The extended period begins with zonal flow in the mid-upper levels
across the local region. A cut off low will be near the southern tip
of Baja California and a trough will be digging across the upper
Midwest and Great Lakes region as strong short wave energy drops
south out of central Canada. The 00z GFS and 00z EURO are in better
agreement than previous model runs especially through the end of the
week. Their solutions diverge somewhat over the weekend and early
next week although local differences don`t appear that significant.
Both models show the aforementioned trough continuing to deepen over
the eastern CONUS Friday sending a dry cold front through the CWA
Friday night/Saturday morning. If a surface low does develop over
the western GOMEX as advertised by both models, this feature should
track well south of our FA to keep rain chances out of the forecast.
A drier airmass filters in over the weekend along with cooler
temperatures in the wake of the cold front. However no freezes are
expected as the core of the airmass should stay well to our north.
As the axis of the trough slides to our east, we will see a brief
period of zonal flow Sunday before the next shortwave and cold front
bring rain chances to the region early next week. Temperatures will
be near or below seasonal norms through most of the period.
&&
.MARINE...
Generally light northerly flow will continue through tonight behind
a decaying frontal boundary across the central Florida Peninsula.
Another weak cold front will cross the forecast waters on Wednesday,
followed by a period of cautionary level offshore winds Wednesday
night into Thursday morning.
&&
.AVIATION (THROUGH 06Z WEDNESDAY)...
With abundant low level moisture in place we will see patchy fog
develop in the pre-dawn hours. We do not expect widespread dense fog
to develop as plenty of mid and upper level clouds will be streaming
from southwest to northeast across the region. For all TAF sites,
kept VSBYS no lower than MVFR levels but will monitor observations
for possible IFR conditions, especially at VLD. After around 15z,
all but possibly VLD returns to VFR conditions. VLD may see
lingering CIGS at or around MVFR for most of the day today. Winds
will be light from the north to northeast.
&&
.FIRE WEATHER...
Drier air will filter into the area behind a cold front Wednesday
and Thursday. Minimum relative humidity values will drop below 35
percent for a portion of our north Florida zones Wednesday and most
or all of north Florida Thursday. However, ERC values, wind and
dispersions will not meet Red Flag criteria.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 72 47 74 41 66 / 10 10 10 0 10
Panama City 70 52 72 46 65 / 10 10 10 0 10
Dothan 69 46 70 40 63 / 10 10 10 0 10
Albany 69 44 70 39 63 / 10 10 10 0 10
Valdosta 69 46 73 41 65 / 10 10 10 0 10
Cross City 74 50 75 43 68 / 20 10 10 0 10
Apalachicola 69 51 70 46 65 / 20 10 10 0 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
AL...None.
GA...None.
FL...None.
GM...None.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
LONG TERM/AVIATION/FIRE WX...BARRY
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
417 AM EST TUE FEB 7 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM
AND LONG TERM SECTIONS HAVE BEEN UPDATED BELOW
&&
.SYNOPSIS...
THE HIGH PRESSURE RIDGE WILL BREAK DOWN TONIGHT AS AN UPPER LEVEL
TROUGH MOVES INTO CENTRAL INDIANA. LIGHT SNOW WILL ACCOMPANY THIS
DISTURBANCE BRINGING A DUSTING TO CENTRAL INDIANA LATE TONIGHT AND
TOMORROW MORNING. FURTHER OUT...A BROAD UPPER LEVEL LOW WILL BRING
ANOTHER CHANCE FOR SNOW SHOWERS LATE IN THE WEEK...FOLLOWED BY
MUCH COLDER AIR AND A RETURN TO WINTER.
&&
.NEAR TERM /THIS MORNING AND TODAY/...
PATCHY FOG WILL BE PERSISTENT ONCE AGAIN THIS MORNING...BUT WILL
SLOWLY ERODE AFTER DAYBREAK. NONETHELESS...THERE WILL BE AN
INCREASE IN CLOUDS AHEAD OF THE APPROACHING UPPER LEVEL TROUGH
PROGGED FOR TONIGHT AND TOMORROW MORNING. AS A RESULT...TRIMMED
TODAY/S HIGHS BACK A FEW DEGREES...BUT WAS STILL ABLE TO GO WITH A
MODEL BLEND. HIGHS WILL TOP OFF IN THE UPPER 30S/LOW 40S OVER THE
NORTHERN TWO-THIRDS OF THE FORECAST AREA...AND UPPER 40S OVER THE
SOUTHERN THIRD.
CURENTLY...TEMPS ARE IN THE LOW 30S NORTH OF I-70 WHERE STRATUS
DECK IS HELPING TO DECREASE RADIATIONAL COOLING. FURTHER SOUTH...
TEMPS HAVE FALLEN INTO THE MID TO UPPER 20S WITH SOME REPORTS OF
FREEZING FOG.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
THE MAIN FOCUS OF THE SHORT TERM IS AN UPPER LEVEL TROUGH PROGGED
FOR TONIGHT AND TOMORROW MORNING.
GEM/GFS/NAM ARE IN GOOD AGREEMENT ON TIMING AND TRACK OF LOW. THE
BULK OF PRECIP WILL NOT MOVE IN UNTIL AFTER WED 06Z...ALTHOUGH
THERE WILL BE A SLIGHT CHANCE FOR SOME RAIN/SNOW MIXTURE OVER THE
SOUTH AND SNOW TO THE NORTH BEFORE THAT. BY THE TIME THE BEST
MOISTURE MOVES IN...TEMPS WILL HAVE FALLEN ENOUGH FOR PRECIP TO BE
IN THE FORM OF SNOW ACROSS ALL OF CENTRAL INDIANA. THIS WILL BE A
QUICK DISTURBANCE AND OUT OF THE AREA BY LATE MORNING TOMORROW. IT
WILL RESULT IN A QUICK DUSTING OF SNOW THOUGH...WITH AMOUNTS
RANGING FROM 2 TO 4 TENTHS OF AN INCH. AFTER THAT...MORE ZONAL
FLOW WILL RETURN...AND THE REMAINDER OF THE SHORT TERM WILL BE DRY.
TEMPS...GENERALLY WENT WITH A MODEL BLEND AND CAME UP WITH NUMBERS
CLOSE TO NORMAL FOR THIS TIME OF YEAR. HIGHS WILL TOP OFF IN THE
MID TO UPPER 30S WITH LOWS IN THE 20S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
MUCH COLDER WEATHER ANTICIPATED FOR THE EXTENDED AS STRONG POLAR
VORTEX NEAR JAMES BAY DRIFTS SOUTHEAST INTO NORTHERN NEW ENGLAND
THROUGH THE PERIOD. THIS WILL RESULT IN AN AMPLIFICATION OF DEEP
UPPER TROUGHING OVER THE EASTERN PART OF THE COUNTRY OVER THE
WEEKEND.
INCREASING CHANCES FOR SNOW SHOWERS ON FRIDAY AS A COLD FRONT
QUICKLY MOVES THROUGH THE REGION. STRONG COLD ADVECTION IN THE WAKE
OF THIS BOUNDARY WILL USHER IN AN ARCTIC AIRMASS WITH HIGH TEMPS
FALLING BACK INTO THE UPPER 20S AND LOWER 30S FOR THE WEEKEND. LOW
LEVEL WIND FIELDS SHIFT TO A N/NW DIRECTION FOR FRIDAY NIGHT SETTING
THE STAGE FOR FAVORABLE BOUNDARY LAYER CONDITIONS FOR SCATTERED LAKE
EFFECT SNOW SHOWERS OFF LAKE MICHIGAN TO WORK INTO THE NORTHERN
PORTIONS OF THE FORECAST AREA. WILL MAINTAIN CHANCES FOR SNOW
SHOWERS FRIDAY NIGHT AS A RESULT. BACKING OF LOW LEVEL WINDS
SATURDAY COMBINED WITH THE ARRIVAL OF LARGE HIGH PRESSURE WILL END
PRECIP WITH DRY COLD AIRMASS PRESENT FOR THE WEEKEND. GREATER
UNCERTAINTY IN THE FORECAST DEVELOPS BY MONDAY AS THE TROUGH PULLS
AWAY TO THE EAST AND RETURN FLOW ESTABLISHES ON THE BACK SIDE OF THE
DEPARTING HIGH. BOTH ECMWF AND OP GFS HAVE A WEAK DISTURBANCE ALOFT
PASSING THROUGH THE FLOW ON MONDAY BRINGING LOW CHANCES FOR RAIN
AND/OR SNOW. TEMPS WILL MODERATE ON MONDAY BUT STILL REMAIN AT OR
JUST BELOW NORMAL IN THE MID AND UPPER 30S.
&&
.AVIATION /DISCUSSION FOR THE 070900Z TAF UPDATE/...
MADE SOME ADJUSTMENTS AT KIND AND KLAF BASED ON CURRENT OBS. CIGS
RUNNING BETWEEN 600-1200FT SHOULD GRADUALLY DROP TO CLOSER TO 600FT
PRIOR TO DAYBREAK AS LOWER CIGS WITHIN THE STRATUS DECK SAG INTO THE
FORECAST AREA FROM THE NORTH. KHUF REMAINS JUST SOUTH OF THE DECK AT
THIS POINT...BUT RECENT SATELLITE TRENDS SUGGESTING DECK MAY EXPAND
INTO KHUF WITHIN THE NEXT TWO HOURS. VLIFR VISIBILITIES REMAIN AN
ISSUE ONLY AT KBMG. WILL CONTINUE TO MONITOR TRENDS AND ADJUST
ACCORDINGLY THROUGH THE REMAINDER OF THE OVERNIGHT.
06Z DISCUSSION FOLLOWS.
IFR EXPECTED AT ALL SITES AT LEAST BRIEFLY THROUGH MID MORNING.
STRATUS DESK HAS ADVECTED/EXPANDED INTO LAF/IND/HUF...AND RUC PROGS
SUGGEST IT WILL ADVECT INTO BMG AROUND 10Z. DECK SHOULD LIFT/ERODE
BY MID MORNING...WITH ONLY SOME CU AND HIGH CLOUDS TOMORROW. CLOUD
IS MOSTLY MVFR ON ITS FRINGES...WITH EXCEPTION OF EASTERN EDGE NEAR
IND. LOW CONFIDENCE IN EXACTLY HOW LOW STRATUS WILL GET AND AT WHAT
TIMES...BUT CLIMATOLOGY WOULD SUGGEST STRATUS WOULD BE AT ITS LOWEST
NEAR AND JUST AFTER DAYBREAK.
INTRODUCED MIDLEVEL CLOUD TOMORROW EVENING IN ADVANCE OF NEXT SYSTEM.
WINDS WILL BE LIGHT TO CALM...BECOMING NORTHERLY AFTER MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM....RYAN
AVIATION...NIELD/RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
326 AM EST TUE FEB 7 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
HIGH PRESSURE WILL GIVE WAY TO AN UPPER WAVE TUESDAY NIGHT THAT
WILL BRING SMALL CHANCES FOR SNOW TO CENTRAL INDIANA INTO
WEDNESDAY MORNING. ANOTHER COUPLE OF WEAK WAVES WILL MOVE THROUGH
EARLY IN THE WEEKEND AND AGAIN ON MONDAY AND BRING MORE SMALL
CHANCES FOR PRECIPITATION. TEMPERATURES WILL ACTUALLY DROP TO NEAR
NORMAL FROM MIDWEEK THROUGH THE WEEKEND WITH BROAD TROUGHING OVER
THE EASTERN PART OF THE COUNTRY.
&&
.NEAR TERM /TONIGHT/...
WITH HIGH PRESSURE SUBSIDENCE OVER THE AREA AND A STRATUS DECK TO
THE WEST WITH WESTERLY LOW LEVEL FLOW OVERNIGHT THINK STRATUS WILL
ADVECT BACK INTO THE NORTHWEST AND OVERSPREAD THE NORTHWESTERN TWO
THIRDS OF THE AREA DURING THE OVERNIGHT HOURS SINCE THERE WILL BE
NOTHING TO STOP IT. WHILE LARGE SCALE MODELS DO NOT DO A GOOD JOB
DEPICTING THIS LOW LEVEL RH FIELDS AND SOUNDINGS FROM THE RUC SHOW
THIS POTENTIAL AND THE RUC DID A MUCH BETTER JOB HANDLING WHAT
HAPPENED THIS MORNING. COULD ALSO SEE SOME PATCHY FOG ACROSS THE
AREA. NOT SURE OF EXTENT OR SPECIFIC LOCATION OF FOG...BUT WITH
RECENT MORNINGS AND FORECAST SOUNDINGS WILL GO AHEAD AND PUT PATCHY
FOG EVERYWHERE. WITH THE INCREASE IN CLOUD COVER THAT THE GFS AND
NAM DON/T HAVE ALSO WENT WITH WARMER LOWS THAN GUIDANCE OVER ALL BUT
THE SOUTHEAST WHERE STRATUS MAY NOT REACH.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
FORECAST FOCUS IS ON CLOUD COVER TUESDAY AND POPS WITH TUESDAY
NIGHT/WEDNESDAY SYSTEM. MODELS ARE IN DECENT AGREEMENT AND WILL USE
A CONSENSUS APPROACH FOR THE MOST PART.
AFOREMENTIONED STRATUS MAY ERODE SOME IN THE LATE MORNING TUESDAY
BUT WILL ALSO START TO SEE AN INCREASE IN CLOUDS AS THE NEXT UPPER
WAVE APPROACHES FROM THE NORTHWEST...SO NET RESULT SHOULD BE MOSTLY
CLOUDY SKIES TO EVEN CLOUDY SKIES IN THE NORTHWEST. WITH MORE CLOUD
COVER IN THE NORTH AND CENTRAL WILL ALSO DROP HIGHS THERE FROM
GUIDANCE. THE UPPER WAVE MOVING IN TUESDAY NIGHT PROVIDES ONLY WEAK
TO AT MOST MODERATE UPPER LEVEL FORCING AND THERE IS NOTHING ELSE
HELPING THIS SYSTEM...NO INSTABILITY...NO LOW LEVEL FORCING...AND
LITTLE MOISTURE. THE BEST FORCING STILL APPEARS TO BE MOVING THROUGH
BETWEEN 6 AND 12Z AND THUS KEPT LOW CHANCE POPS GOING THEN WITH
SLIGHT CHANCES FOR 6 HOURS ON EITHER SIDE. SOUNDINGS IN ALL BUT THE
SOUTH LOOK COLD ENOUGH FOR ALL SNOW. WILL START WITH A RAIN SNOW MIX
IN THE SOUTH BEFORE CHANGING OVER TO ALL SNOW. LITTLE TO NO
ACCUMULATION EXPECTED.
BY WEDNESDAY 18Z THE UPPER WAVE HAS MOVED OUT OF THE AREA AND
RIDGING IS MOVING BACK INTO THE AREA FROM THEN ON SO DRY WEATHER
FROM THAT POINT THROUGH THURSDAY. WENT COOLER THAN GUIDANCE
WEDNESDAY WITH COLD ADVECTION OCCURRING.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
OVERALL THE EXTENDED WILL BE A QUIET PERIOD. HOWEVER THERE ARE TWO
SYSTEMS THAT MAY GIVE LOW CHANCES OF PRECIP. ONE PERIOD IS FRIDAY
AFTERNOON AND NIGHT AS COLD FRONT MOVES THROUGH FRIDAY AFTERNOON
FOLLOWED BY AN UPPER TROUGH FRIDAY NIGHT AND SATURDAY. THE GFS STILL
HAS US DRY...BUT THE EUROPEAN AND CANADIAN AS WELL AS CONSALL GIVES
US LOW CHANCES OF PRECIPITATION. TEMPERATURES MAY BE WARM ENOUGH
FOR MIXED PRECIP ACROSS OUR SOUTH FRIDAY AFTERNOON. OTHERWISE...WILL
GO WITH A SLIGHT CHANCE OF SNOW SHOWERS.
THE UPPER TROUGH MOVES ON TO THE EAST OVER THE WEEKEND AND WARM
ADVECTION SETS UP BY MONDAY AHEAD OF THE NEXT SYSTEM. THE GFS
BARELY BRINGS PRECIP INTO OUR NORTHWEST BY 00Z TUESDAY AND THE
EUROPEAN IS EVEN SLOWER. WILL TRIM POPS A LITTLE...BUT KEEP LOW
CHANCES ACROSS OUR WEST BY LATE DAY 7. DID NOT MAKE ANY SIGNIFICANT
CHANGE TO ALL BLEND TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 070900Z TAF UPDATE/...
MADE SOME ADJUSTMENTS AT KIND AND KLAF BASED ON CURRENT OBS. CIGS
RUNNING BETWEEN 600-1200FT SHOULD GRADUALLY DROP TO CLOSER TO 600FT
PRIOR TO DAYBREAK AS LOWER CIGS WITHIN THE STRATUS DECK SAG INTO THE
FORECAST AREA FROM THE NORTH. KHUF REMAINS JUST SOUTH OF THE DECK AT
THIS POINT...BUT RECENT SATELLITE TRENDS SUGGESTING DECK MAY EXPAND
INTO KHUF WITHIN THE NEXT TWO HOURS. VLIFR VISIBILITIES REMAIN AN
ISSUE ONLY AT KBMG. WILL CONTINUE TO MONITOR TRENDS AND ADJUST
ACCORDINGLY THROUGH THE REMAINDER OF THE OVERNIGHT.
06Z DISCUSSION FOLLOWS.
IFR EXPECTED AT ALL SITES AT LEAST BRIEFLY THROUGH MID MORNING.
STRATUS DESK HAS ADVECTED/EXPANDED INTO LAF/IND/HUF...AND RUC PROGS
SUGGEST IT WILL ADVECT INTO BMG AROUND 10Z. DECK SHOULD LIFT/ERODE
BY MID MORNING...WITH ONLY SOME CU AND HIGH CLOUDS TOMORROW. CLOUD
IS MOSTLY MVFR ON ITS FRINGES...WITH EXCEPTION OF EASTERN EDGE NEAR
IND. LOW CONFIDENCE IN EXACTLY HOW LOW STRATUS WILL GET AND AT WHAT
TIMES...BUT CLIMATOLOGY WOULD SUGGEST STRATUS WOULD BE AT ITS LOWEST
NEAR AND JUST AFTER DAYBREAK.
INTRODUCED MIDLEVEL CLOUD TOMORROW EVENING IN ADVANCE OF NEXT SYSTEM.
WINDS WILL BE LIGHT TO CALM...BECOMING NORTHERLY AFTER MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP/SMF
SHORT TERM...CP
LONG TERM....JH
AVIATION...NIELD/RYAN
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1139 PM EST MON FEB 6 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
HIGH PRESSURE WILL GIVE WAY TO AN UPPER WAVE TUESDAY NIGHT THAT
WILL BRING SMALL CHANCES FOR SNOW TO CENTRAL INDIANA INTO
WEDNESDAY MORNING. ANOTHER COUPLE OF WEAK WAVES WILL MOVE THROUGH
EARLY IN THE WEEKEND AND AGAIN ON MONDAY AND BRING MORE SMALL
CHANCES FOR PRECIPITATION. TEMPERATURES WILL ACTUALLY DROP TO NEAR
NORMAL FROM MIDWEEK THROUGH THE WEEKEND WITH BROAD TROUGHING OVER
THE EASTERN PART OF THE COUNTRY.
&&
.NEAR TERM /TONIGHT/...
WITH HIGH PRESSURE SUBSIDENCE OVER THE AREA AND A STRATUS DECK TO
THE WEST WITH WESTERLY LOW LEVEL FLOW OVERNIGHT THINK STRATUS WILL
ADVECT BACK INTO THE NORTHWEST AND OVERSPREAD THE NORTHWESTERN TWO
THIRDS OF THE AREA DURING THE OVERNIGHT HOURS SINCE THERE WILL BE
NOTHING TO STOP IT. WHILE LARGE SCALE MODELS DO NOT DO A GOOD JOB
DEPICTING THIS LOW LEVEL RH FIELDS AND SOUNDINGS FROM THE RUC SHOW
THIS POTENTIAL AND THE RUC DID A MUCH BETTER JOB HANDLING WHAT
HAPPENED THIS MORNING. COULD ALSO SEE SOME PATCHY FOG ACROSS THE
AREA. NOT SURE OF EXTENT OR SPECIFIC LOCATION OF FOG...BUT WITH
RECENT MORNINGS AND FORECAST SOUNDINGS WILL GO AHEAD AND PUT PATCHY
FOG EVERYWHERE. WITH THE INCREASE IN CLOUD COVER THAT THE GFS AND
NAM DON/T HAVE ALSO WENT WITH WARMER LOWS THAN GUIDANCE OVER ALL BUT
THE SOUTHEAST WHERE STRATUS MAY NOT REACH.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
FORECAST FOCUS IS ON CLOUD COVER TUESDAY AND POPS WITH TUESDAY
NIGHT/WEDNESDAY SYSTEM. MODELS ARE IN DECENT AGREEMENT AND WILL USE
A CONSENSUS APPROACH FOR THE MOST PART.
AFOREMENTIONED STRATUS MAY ERODE SOME IN THE LATE MORNING TUESDAY
BUT WILL ALSO START TO SEE AN INCREASE IN CLOUDS AS THE NEXT UPPER
WAVE APPROACHES FROM THE NORTHWEST...SO NET RESULT SHOULD BE MOSTLY
CLOUDY SKIES TO EVEN CLOUDY SKIES IN THE NORTHWEST. WITH MORE CLOUD
COVER IN THE NORTH AND CENTRAL WILL ALSO DROP HIGHS THERE FROM
GUIDANCE. THE UPPER WAVE MOVING IN TUESDAY NIGHT PROVIDES ONLY WEAK
TO AT MOST MODERATE UPPER LEVEL FORCING AND THERE IS NOTHING ELSE
HELPING THIS SYSTEM...NO INSTABILITY...NO LOW LEVEL FORCING...AND
LITTLE MOISTURE. THE BEST FORCING STILL APPEARS TO BE MOVING THROUGH
BETWEEN 6 AND 12Z AND THUS KEPT LOW CHANCE POPS GOING THEN WITH
SLIGHT CHANCES FOR 6 HOURS ON EITHER SIDE. SOUNDINGS IN ALL BUT THE
SOUTH LOOK COLD ENOUGH FOR ALL SNOW. WILL START WITH A RAIN SNOW MIX
IN THE SOUTH BEFORE CHANGING OVER TO ALL SNOW. LITTLE TO NO
ACCUMULATION EXPECTED.
BY WEDNESDAY 18Z THE UPPER WAVE HAS MOVED OUT OF THE AREA AND
RIDGING IS MOVING BACK INTO THE AREA FROM THEN ON SO DRY WEATHER
FROM THAT POINT THROUGH THURSDAY. WENT COOLER THAN GUIDANCE
WEDNESDAY WITH COLD ADVECTION OCCURRING.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
OVERALL THE EXTENDED WILL BE A QUIET PERIOD. HOWEVER THERE ARE TWO
SYSTEMS THAT MAY GIVE LOW CHANCES OF PRECIP. ONE PERIOD IS FRIDAY
AFTERNOON AND NIGHT AS COLD FRONT MOVES THROUGH FRIDAY AFTERNOON
FOLLOWED BY AN UPPER TROUGH FRIDAY NIGHT AND SATURDAY. THE GFS STILL
HAS US DRY...BUT THE EUROPEAN AND CANADIAN AS WELL AS CONSALL GIVES
US LOW CHANCES OF PRECIPITATION. TEMPERATURES MAY BE WARM ENOUGH
FOR MIXED PRECIP ACROSS OUR SOUTH FRIDAY AFTERNOON. OTHERWISE...WILL
GO WITH A SLIGHT CHANCE OF SNOW SHOWERS.
THE UPPER TROUGH MOVES ON TO THE EAST OVER THE WEEKEND AND WARM
ADVECTION SETS UP BY MONDAY AHEAD OF THE NEXT SYSTEM. THE GFS
BARELY BRINGS PRECIP INTO OUR NORTHWEST BY 00Z TUESDAY AND THE
EUROPEAN IS EVEN SLOWER. WILL TRIM POPS A LITTLE...BUT KEEP LOW
CHANCES ACROSS OUR WEST BY LATE DAY 7. DID NOT MAKE ANY SIGNIFICANT
CHANGE TO ALL BLEND TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 07/06Z TAFS/...
IFR EXPECTED AT ALL SITES AT LEAST BRIEFLY THROUGH MID MORNING.
STRATUS DESK HAS ADVECTED/EXPANDED INTO LAF/IND/HUF...AND RUC PROGS
SUGGEST IT WILL ADVECT INTO BMG AROUND 10Z. DECK SHOULD LIFT/ERODE
BY MID MORNING...WITH ONLY SOME CU AND HIGH CLOUDS TOMORROW. CLOUD
IS MOSTLY MVFR ON ITS FRINGES...WITH EXCEPTION OF EASTERN EDGE NEAR
IND. LOW CONFIDENCE IN EXACTLY HOW LOW STRATUS WILL GET AND AT WHAT
TIMES...BUT CLIMATOLOGY WOULD SUGGEST STRATUS WOULD BE AT ITS LOWEST
NEAR AND JUST AFTER DAYBREAK.
INTRODUCED MIDLEVEL CLOUD TOMORROW EVENING IN ADVANCE OF NEXT SYSTEM.
WINDS WILL BE LIGHT TO CALM...BECOMING NORTHERLY AFTER MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP/SMF
SHORT TERM...CP
LONG TERM....JH
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
314 AM EST TUE FEB 07 2012
.Short Term (Today - Wednesday)...
High pressure in place along with weak ridging aloft will keep
things dry today, although will have to deal with patchy
fog/freezing fog potential again through the morning hours. IR
satellite imagery currently shows a batch of low stratus across the
Great Lakes region to as far south as the I 74 corridor over central
and southern Indiana. HRRR has been consistent in showing these
clouds marching steadily southeast through the pre-dawn hours,
arriving near the Ohio River just after dawn. Therefore, skies
should clear in most spots with calm winds and subsident airmass.
This will lead to patchy fog formation, some of which will likely be
dense around dawn. Most likely areas will be in valleys and near
rivers and streams. With temperatures below freezing in most spots
will have to watch for slick spots. Will spend the rest of the
morning monitoring obs and issuing SPS or headline products if need
be. Right now, the only real indication of fog is over the Lake
Cumberland region.
Above mentioned status deck will likely scatter out over southern
Indiana this morning with upper level clouds beginning stream
overhead through the day. With low temperatures cooler than expected
this morning, have lowered highs a bit for this afternoon. Southern
Indiana will likely not make it out of the upper 40s with lower
level cloud cover this morning. Elsewhere, lower 50s can be expected
with mid 50s possible south.
The next weather making system will arrive after Midnight tonight as
an upper level impulse quickly ejects across the plains, absorbing
an upper low currently over NE Colorado. What may initially start
out as rain or a rain/snow mix across southern Indiana and central
Kentucky should quickly change over to snow as wet bulbing occurs
with low level saturation. Surface temperatures may stay just above
freezing in a few locations however warm layer at the surface will
be very shallow and should still support mostly snow. South of a
Bowling Green to Lake Cumberland line, precipitation type is more in
question and could end up being more rain and possibly a rain/snow
mix by dawn.
Best chances for precipitation, whether it be rain or snow, will be
from 3 AM EST to 8 AM EST early Wednesday. Will have to watch for a
moderate band of snow setting up anywhere from along and south of
the Ohio River to along and north of a Bowling Green to Lexington
line between 3 AM EST and dawn. This will occur just ahead of sharp
shortwave trough axis with frontogenesis coinciding with the left
exit region of an intensifying 100 to 120 knot upper level jet.
Models continue to indicate low amounts of QPF with this quick
hitting system, although have steadily increased amounts. Will have
to watch trends over the next 24 hours as banding does appear
possible with this setup and could produce a narrow swath of higher
QPF. That being said, ground and road temperatures should be well
above freezing with recent warm weather so do not expect any real
accumulation on these surfaces. Could see a dusting on grassy and
elevated surfaces by the daylight hours on Wednesday.
Upper level features quickly depart to the east by midday Wednesday,
however plentiful low level moisture between 1000-850 mb suggests
some flurries or sprinkles will be possible. Models are suggesting a
warm up to the low and mid 40s during the day however with overcast
skies expected, have a feeling temperatures will have trouble
getting out of the 30s. Therefore, will call for precipitation type
mostly in light snow or flurry category as any warm layer will be
confined to the surface and low level lapse rates will quickly
steepen. Could even see a few snow bursts through the day on
Wednesday as low levels edge toward a low degree of convective
instability. Again, expecting no real accumulations. Flurries or
sprinkles will linger through the day on Wednesday, along with
mostly cloudy skies.
.Long Term (Wednesday night - Monday)...
Wednesday night through Thursday night...
Main upper impulse will be exiting the area, but still expect some
residual low-level moisture to lingering Wednesday evening.
Subsidence and very shallow moist layer weigh against any precip so
no POPs in the forecast, but moisture and NW flow are sufficient
reason to hold onto a few early evening snow flurries in the eastern
tier.
Cold and dry high pressure on Thursday, with a broad, weak upper
trof overhead. MOS guidance is generally too warm in a shallow cold
air mass like this, so this forecast is more in line with the raw
model temps, with highs in the lower 40s in spite of full sunshine.
Clear and chilly Thursday night, but lows in the mid-upper 20s are
right in line with climo.
Friday through Monday...
Low-confidence forecast here as the models start to diverge. ECMWF
and GFS both drag some combination of a Clipper and/or cold front
across the Ohio Valley Friday night. ECMWF is trending more bullish
with southern-stream phasing and associated moisture. Will not jump
on this solution just yet but it bears watching. For now will go
with a slight chance for snow showers Fri night, mainly east of
I-65.
Cold high pressure plunges south from Canada for the weekend. Below
normal temperatures are a slam dunk but the question remains, how
much below normal? Coldest 850mb temps will be Saturday, when GFS
gets as cold as -14C. Current forecast max temps in the mid 30s may
be a bit too warm. Coldest night is Sat night, with lower 20s
across most locations. Not going for the quick rebound indicated by
extended GFS MOS on Sunday, given the cold start and model bias of
moving a high pressure ridge east too quickly. Expect highs in the
mid/upper 30s even with the thermal trof to our east.
Another southern stream system will affect the Ohio Valley early
next week, but model discrepancies are too large to jump on any one
solution just yet. Will keep Monday dry for now, as the quicker
ECMWF is also the less bullish model as far as QPF. Temps recover to
the high side of normal by Monday.
&&
.Aviation (06Z TAF Issuance)...
High pressure at the surface and aloft will control the weather for
much of the day, however will provide the proper ingredients for fog
formation toward dawn. With nearly calm winds, clear skies, and a
moist surface from recent rains feel the TAF sites will see some
MVFR and possibly IFR visibilities around dawn. Latest satellite
imagery shows low stratus over central Indiana that will gradually
build south through the pre-dawn hours, making it near the Ohio
River around dawn. Will actually keep forecast optimistic after
sunrise as MVFR visibilities at SDF/LEX quickly go back to VFR and
only FEW/SCT stratocu make it south of the river through the morning
hours. Expect BWG to see the usual low MVFR/IFR fog under good
radiational cooling, quickly going back to VFR after dawn.
Expect a quiet day otherwise with northwest winds and increasing mid
level clouds. Expect chances for rain/snow to begin just after the
forecast period early Wednesday.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......BJS
Long Term........RAS
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
401 AM EST TUE FEB 7 2012
.SYNOPSIS...
A DRY, BUT CLOUDY AND COLD DAY ACROSS MUCH OF THE AREA. LOCATIONS
WELL SOUTH OF PITTSBURGH, WILL SEE MORE SUN AND WARMER
TEMPERATURES. LOW PRESSURE WILL BRING WIDESPREAD SNOW SHOWERS TO
THE AREA WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW CLOUDS ARE NOW MOVING SOUTHWARD ACROSS THE NORTHERN HALF OF
THE FORECAST AREA. LATEST HRRR HAS A GOOD HANDLE ON THE TIMING.
EXPECT CLOUDS TO REACH PIT BY 12Z AND THE PA-WV BORDER BY 15Z.
LOOKS LIKE THE CLOUDS WILL STOP HERE, LEAVING MUCH OF N WV, WITH
THE EXCEPTION OF THE PANHANDLE, MAINLY SUNNY.
THE CLOUDS WILL HAVE A BIG EFFECT ON TEMPS TODAY. OBVIOUSLY, WHERE
THE CLOUDS ARE, TEMPS WILL BE LOWER, WHERE THE CLOUDS AREN`T,
WARMER TEMPS. UNDER THE CLOUD COVER, WILL LEAN CLOSER TO THE
COLDER 21Z SREF, SOUTH OF THE CLOUD COVER, WILL HAVE NUMBERS
CLOSE TO THE 00Z MAV.
MODELS ARE SHOWING BOUNDARY LAYER MOISTURE DECREASING A BIT THIS
AFTERNOON. THIS MAY ALLOW FOR THE SOUTHERN PORTION OF THE CLOUDS
DECK TO BREAK UP, BUT WOULD EXPECT NORTHERN LOCATIONS TO REMAIN
CLOUDY ALL DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
SHORTWAVE IN THE SOUTHERN STREAM OF CONFLUENT FLOW PROJECTED OVER
THE REGION IS PROGGED TO GENERATE SNOW SHOWERS ALONG THE SOUTHWARD
SAGGING, AFOREMENTIONED COLD FRONT LATE TUESDAY NIGHT/WEDNESDAY.
CHANCE PRECIP PROBABILITIES WERE INCLUDED FOR THIS SCENARIO, BUT
WITH BETTER NUMBERS OVER SOUTHERN ZONES DUE TO EXPECTED PROGRESS
OF THE FRONT. LIKELY NUMBERS THAT WERE FORECAST FOR THE RIDGES ARE
DUE TO EXTRA SUPPORT VIA DEVELOPING UPSLOPE.
OVERALL, LIGHT SNOW ACCUMULATION IS POSSIBLE ON WEDNESDAY WITH
AMOUNTS LIMITED BY THE PROGRESSIVE NATURE OF THE SYSTEM AND
SURFACE TEMPERATURES ABOVE FREEZING.
TEMPERATURES WERE FORECAST NEAR NORMAL USING A BLEND OF GUIDANCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LATEST ECMWF AND GFS MODEL OUTPUT SHOWS A DEEP UPPER TROUGH SWINGING
THROUGH EASTERN CANADA BY THE WEEKEND. TIMING OF THE ASSOCIATED
COLD FRONT STILL VARIES SOMEWHAT BETWEEN GFS/ECMWF, BUT LATEST
THINKING IS THAT THE FRONT WILL PUSH ACROSS THE FORECAST AREA LATE
FRIDAY, BRINGING SCATTERED SNOW SHOWERS, POSSIBLY MIXING WITH RAIN
SHOWERS IN THE SOUTH, AND A RETURN TO MORE WINTER-LIKE TEMPERATURES.
SURFACE HIGH PRESSURE AND DRIER AIR ARE PROJECTED TO MOVE OVER
THE OHIO VALLEY ON SUNDAY AND MONDAY.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
PER BLEND OF RECENT SURFACE AND SATELLITE DATA, NAM AND HRRR MODEL
OUTPUT, AND GFS LAMP, EXPECT SHALLOW COLD FRONTAL BAND OF
STRATOCUMULUS TO SPREAD SOUTHWARD AT 25 KTS THROUGH MUCH OF THE
UPPER OHIO VALLEY OVERNIGHT. CEILINGS, GENERALLY 8-15 HFT, WILL
STRADDLE IFR LEVELS, AND REACH AS FAR SOUTH AS KZZV-KHLG-KLBE BY
13Z. HAVE LOW CONFIDENCE THAT THE CLOUDS REACH KMGW.
SURFACE WINDS WILL GO FROM WEST NEAR 5 KTS TO NORTH-NORTHWEST NEAR
10 KTS BY MIDDAY.
EXPECT ANY IFR CEILINGS TO LIFT TO MVFR LEVELS BY AFTERNOON, AND
REMAIN MVFR TONIGHT. THERE MAY EVEN BE SUFFICIENT EROSION FOR
SOUTHERN CEILINGS TO DISSIPATE FOR A WHILE.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
AN EASTBOUND LOW PRESSURE SYSTEM WILL DEEPEN THE COLD FRONT TO YIELD
MVFR SNOW SHOWERS BY DAYTIME WEDNESDAY. ENSUING HIGH PRESSURE WILL
PROVIDE VFR THURSDAY AND FRIDAY. A COLD FRONTAL BAND OF SNOW
SHOWERS WILL PROVIDE RESTRICTIONS SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
1253 AM EST TUE FEB 7 2012
.SYNOPSIS...
A DRY, BUT CLOUDY AND COLD DAY ACROSS MUCH OF THE AREA. LOCATIONS
SOUTH OF PITTSBURGH MAY SEE MORE SUN AND WARMER TEMPERATURES. LOW
PRESSURE WILL BRING WIDESPREAD SNOW SHOWERS TO THE AREA WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
BIGGEST CHANGE TO PREVIOUS FORECAST IS THE INCREASE IN CLOUD COVER
FROM NORTH TO SOUTH AS DAWN APPROACHES. LATEST 00Z RUN AND 02Z HRRR,
INDICATE THE AREA OF SC OVER NW OHIO AND THE GREAT LAKES FILLING
IN AND SLOWLY MOVING SOUTHWARD. IT APPEARS THAT THESE CLOUDS ARE
ASSOCIATED WITH A WEAK COLD FRONT, WHICH WILL WASH OUT OVER
SOUTHERN PA THIS AFTERNOON. MODELS ARE SHOWING THAT NEITHER THE
FRONT, NOR THE CLOUDS, WILL REACH FAR SOUTHERN PA OR N WV.
THE CLOUDS WILL HAVE A BIG EFFECT ON TEMPS TODAY. OBVIOUSLY, WHERE
THE CLOUDS ARE, TEMPS WILL BE LOWER, WHERE THE CLOUDS AREN`T,
WARMER TEMPS. UNDER THE CLOUD COVER, WILL LEAN CLOSER TO THE
COLDER 21Z SREF, SOUTH OF THE CLOUD COVER, WILL HAVE NUMBERS
CLOSE TO THE 00Z MAV.
MODELS ARE SHOWING BOUNDARY LAYER MOISTURE DECREASING A BIT THIS
AFTERNOON. THIS MAY ALLOW FOR THE SOUTHERN PORTION OF THE CLOUDS
DECK TO BREAK UP, BUT WOULD EXPECT NORTHERN LOCATIONS TO REMAIN
CLOUDY ALL DAY.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
SHORTWAVE IN THE SOUTHERN STREAM OF CONFLUENT FLOW PROJECTED OVER
THE REGION IS PROGGED TO GENERATE SNOW SHOWERS ALONG THE SOUTHWARD
SAGGING, AFOREMENTIONED COLD FRONT LATE TUESDAY NIGHT/WEDNESDAY.
CHANCE PRECIP PROBABILITIES WERE INCLUDED FOR THIS SCENARIO, BUT
WITH BETTER NUMBERS OVER SOUTHERN ZONES DUE TO EXPECTED PROGRESS
OF THE FRONT. LIKELY NUMBERS THAT WERE FORECAST FOR THE RIDGES ARE
DUE TO EXTRA SUPPORT VIA DEVELOPING UPSLOPE.
OVERALL, LIGHT SNOW ACCUMULATION IS POSSIBLE ON WEDNESDAY WITH
AMOUNTS LIMITED BY THE PROGRESSIVE NATURE OF THE SYSTEM.
TEMPERATURES WERE FORECAST NEAR NORMAL USING A BLEND OF GUIDANCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LATEST ECMWF AND GFS MODEL OUTPUT SHOWS A DEEP UPPER TROUGH SWINGING
THROUGH EASTERN CANADA BY THE WEEKEND. TIMING OF THE ASSOCIATED
COLD FRONT STILL VARIES SOMEWHAT BETWEEN GFS/ECMWF, BUT LATEST
THINKING IS THAT THE FRONT WILL PUSH ACROSS THE FORECAST AREA LATE
FRIDAY, BRINGING SCATTERED SNOW SHOWERS, POSSIBLY MIXING WITH RAIN
SHOWERS IN THE SOUTH, AND A RETURN TO MORE WINTER-LIKE TEMPERATURES.
SURFACE HIGH PRESSURE AND DRIER AIR ARE PROJECTED TO MOVE OVER
THE OHIO VALLEY ON SUNDAY AND MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
PER BLEND OF RECENT SURFACE AND SATELLITE DATA, NAM AND HRRR MODEL
OUTPUT, AND GFS LAMP, EXPECT SHALLOW COLD FRONTAL BAND OF
STRATOCUMULUS TO SPREAD SOUTHWARD AT 25 KTS THROUGH MUCH OF THE
UPPER OHIO VALLEY OVERNIGHT. CEILINGS, GENERALLY 8-15 HFT, WILL
STRADDLE IFR LEVELS, AND REACH AS FAR SOUTH AS KZZV-KHLG-KLBE BY
13Z. HAVE LOW CONFIDENCE THAT THE CLOUDS REACH KMGW.
SURFACE WINDS WILL GO FROM WEST NEAR 5 KTS TO NORTH-NORTHWEST NEAR
10 KTS BY MIDDAY.
EXPECT ANY IFR CEILINGS TO LIFT TO MVFR LEVELS BY AFTERNOON, AND
REMAIN MVFR TONIGHT. THERE MAY EVEN BE SUFFICIENT EROSION FOR
SOUTHERN CEILINGS TO DISSIPATE FOR A WHILE.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
AN EASTBOUND LOW PRESSURE SYSTEM WILL DEEPEN THE COLD FRONT TO YIELD
MVFR SNOW SHOWERS BY DAYTIME WEDNESDAY. ENSUING HIGH PRESSURE WILL
PROVIDE VFR THURSDAY AND FRIDAY. A COLD FRONTAL BAND OF SNOW
SHOWERS WILL PROVIDE RESTRICTIONS SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
434 AM EST TUE FEB 7 2012
.SYNOPSIS...
ISSUED AT 427 AM EST TUE FEB 7 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW RATHER SHEARED
POSITIVELY TILTED SHRTWV DROPPING SEWD THRU THE UPR LKS IN
PREVAILING NW FLOW ALF BTWN TROF OVER QUEBEC AND UPR RDG OVER WRN
CAN. ACCOMPANYING SHARP COLD FNT THAT SURGED THRU THE FA YDAY HAS
NOW PUSHED TO THE S. ALTHOUGH MUCH COLDER AIR IS FOLLOWING THE FNT
WITH NNE FLOW AND 00Z H85 TEMPS RANGING FM 0C AT GRB TO -10C AT INL
AND -17C AT YPL...SGNFT LES HAS NOT DEVELOPED EVEN IN AREAS FAVORED
BY THE NNE FLOW. KEY FACTORS APPEAR TO BE IMPRESSIVE DRYING
REFLECTED BY 00Z YPL RAOB /00Z PWAT 0.06 INCH/ THAT IS STEADILY
ERODING THE BACK EDGE OF THE LK CLD AS SHOWN ON IR STLT IMAGERY...
SUBSIDENCE ASSOCIATED WITH FAIRLY VIGOROUS DNVA/CAD/DEEP LYR QVECTOR
DVGC IN THE WAKE OF THE SHRTWV THAT IS CAUSING THE LLVL FLOW TO
BECOME ACYC AND SINK INVRN BASE TO ARND H9 AS SHOWN ON THE 00Z INL
AND YPL RAOBS. UNDER SFC RDG AXIS IN ONTARIO EXTENDING E FM HI
CENTER NEAR LK WINNIPEG...SKIES ARE MOCLR...AND SFC TEMPS/DWPTS HAVE
FALLEN INTO THE ZERO TO -10F RANGE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EST TUE FEB 7 2012
TODAY...COLD NLY FLOW IS FCST TO PERSIST THRU THIS MRNG BEFORE HI
PRES CENTER BLDG FM LK WINNIPEG INTO MN CAUSES THE LLVL FLOW TO BACK
TO THE W BY LATE IN THE DAY. THE COLDEST MODELS...NOTABLY THE 00Z
CNDN AND LOW WRF-ARW...SHOW H85 TEMPS SINKING TO -15 TO -17C OVER
SCNTRL LK SUP THIS MRNG WHILE THE WARMER 00Z NAM/GFS INDICATE THESE
TEMPS WL FALL NO LOWER THAN -14C OR SO. THE DIFFERENCE APPEARS TO BE
RELATED TO THE INVRN HGT FCST...WITH THE WARMER MODELS INDICATING A
LOWER INVRN BASE AOB 3K FT /NAM/ AS COMPARED TO ARND 4K FT
/WRF-ARW/. SINCE DEEP LYR QVECTOR DVGC/SUBSIDENCE WL INTENSIFY THRU
THE DAY AND TRENDS ON OBSVD SKY COVER OVER LK SUP SUG THE INVRN IS
CRASHING...WL TEND TO FOLLOW THE WARMER/LO INVRN BASE DEPICTED BY
THE 00Z NAM. THIS MODEL SHOWS ALMOST NO PCPN EVEN IN THE N WIND SN
BELTS WITH DIFFLUENT FLOW/H925-85 DEWPT DEPRESSION AS HI AS 7-10C
EVEN OVER THE N WIND SN BELTS THAT WOULD OTRW BE FAVORED BY THE LLVL
FLOW. SO ALTHOUGH SOME LES IS LIKELY TO BREAK OUT IN THE NEXT FEW
HRS THRU 12Z WITH THE ARRIVAL OF COLDER AIR...ANY SN ACCUM SHOULD BE
NO MORE THAN ARND AN INCH EVEN OVER THE HIER TERRAIN. BACKING MORE
ACYC FLOW THIS AFTN WITH INVRN BASE REMAINING BLO 3K FT SHOULD
DIMINISH THE LES FURTHER. ALTHOUGH DAYTIME TEMPS WL BE JUST A BIT
BELOW NORMAL...RECENT WARMTH WL MAKE THE DAY FEEL EVEN COLDER...
ESPECIALLY THIS MRNG WITH A STEADY N WIND.
TNGT...SFC HI PRES RDG AXIS IS FCST TO BE NEARLY OVHD IN THE EVNG
BUT THEN SHIFT TO THE S. WITH CONTINUED SUBSIDENCE AND THE FLOW
BACKING TO THE W...EXPECT SKIES TO TURN MOCLR EXCEPT PERHAPS OVER
THE KEWEENAW AND NEAR LK SUP E OF MUNISING. PWAT IS FCST TO BE 0.10
INCH AT 00Z...SO EXPECT A QUICK FALL OF TEMP IN THE EVNG WITH LGT
WINDS...SO ACCELERATED EARLY FALL OF TEMP. ONCE THE RDG SHIFTS TO
THE S OVERNGT...A STRONGER WNW WIND WL DVLP...WITH H925 WINDS FCST
UP TO 30-35 KTS. RETAINED GOING FCST MIN TEMPS AOB THE LO END OF
GUIDANCE PER VERY DRY AIR/OBSVD CHILL UPSTREAM OVER THE MORE
SHELTERED SRN TIER. TEMPS WL BE QUITE A BIT WARMER NEAR THE MORE
EXPOSED LK SUP AND UNDER THE SHARPER PRES GRADIENT FARTHER N OF THE
RDG AXIS...ESPECIALLY OVER THE E WHERE SOME LO CLDS MAY LINGER NEAR
THE SHORE THRU THE NGT UNDER WNW H925 FLOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 427 AM EST TUE FEB 7 2012
TROUGH WILL BE EXITING INTO EASTERN CANADA TO START THE LONG TERM
WHICH ALLOWS FOR HEIGHTS TO RISE FM PLAINS INTO GREAT LAKES. AT THE
SFC...HIGH PRESSURE OVER THE PLAINS SLIDES SOUTH ON WEDNESDAY
ALLOWING FOR WESTERLY WINDS AT LOW-LEVELS OVR UPR LAKES INTO
WEDNESDAY NIGHT. WEST WINDS ALONG WITH JUST SCT MID CLOUDS RESULTED
IN RAISING MAX TEMPS TOWARD HIGHER END OF GUIDANCE /AROUND 30 INLAND
AND INTO THE MID 30S NEAR LK SUPERIOR/. NEXT COLD FRONT WILL BE
DROPPING SOUTH ACROSS ONTARIO ON WEDNESDAY NIGHT...SO EXPECT AT
LEAST LGT WEST WINDS TO PERSIST THROUGH THE NIGHT. INLAND AREAS
COULD TRY TO DECOUPLE AND FALL INTO THE TEENS...BUT TEMPS ALONG
SHORELINES OF LK SUPERIOR AND LK MICHIGAN SHOULD STAY IN THE MID TO
UPR 20S. FCST SOUNDINGS FM BOTH NAM AND GFS INDICATE CONDITIONS TOO
DRY TO SUPPORT ANY PCPN AHEAD OF THE FRONT IN THE WESTERLY FLOW.
HAVE REMOVED ANY MENTION OF SNOW UNTIL THURSDAY...EVEN OVR THE
KEWEENAW PENINSULA.
CHANGES BEGIN TO OCCUR LATER THURSDAY AS ARCTIC COLD FRONT IS FCST
TO ARRIVE. PROBABLY WILL SEE FALLING TEMPS...BUT AT THIS POINT STUCK
WITH NORMAL DIURNAL TEMP CURVE AS PRIMARY COOLING FM FROPA DOES NOT
OCCUR UNTIL LATE IN THE DAY. SOUNDINGS SHOW SUFFICIENT MOISTENING TO
JUSTIFY SOME SNOW SHOWERS BY LATE AFTN OVR KEWEENAW. ELSEWHERE...
CHANCES OF PCPN ON THURSDAY LOOK MINIMAL. LK EFFECT THEN BECOMES
MORE OF AN ISSUE BY THURSDAY EVENING AS NW WINDS IN BLYR VEER MORE
NORTHERLY. H85 TEMPS FALLING BLO -20C PER GFS/ECMWF LEAD TO SURGE OF
OVER-WATER INSTABILITY WITH LAKE EFFECT EQL AOA 8KFT AND SFC-H85
LAPSE RATES OVR 9C/KM. INSTABILITY IS SUPPLEMENTED BY MID LEVEL
MOISTURE /UP TO H7/. OVERALL SETUP APPEARS FAVORABLE FOR MODERATE
AND POSSIBLY HEAVY LK EFFECT SNOW SHOWERS THURSDAY NIGHT INTO
FRIDAY. SNOW WILL BE FLUFFY AS MAJORITY OF LAKE EFFECT CONVECTIVE
LAYER IS WITHIN THE DENDRITIC GROWTH ZONE. SLR/S FM COBB METHOD IN
BUFKIT RISE WELL ABOVE 20:1.
ONLY MAIN ISSUE TO SORT OUT STILL IS EXACT BLYR WIND DIRECTION. NAM
IS STRONGEST WITH SFC TROUGH AND ASSOCIATED NORTHEAST WINDS DEVELOPING
IN THE WAKE OF THE TROUGH. GFS/ECMWF ARE MORE NORTHERLY WITH THE
WINDS WHILE CANADIAN SHOWS WINDS REMAINING FM NORTHWEST. DO LIKE THE
NAM IDEA INDICATING SHARP WIND SHIFT JUST IN WAKE OF ARCTIC
FRONT...BUT WENT WITH BLEND OF NAM AND PREVIOUS FCST FOR THE WINDS.
RESULT OF THIS CHOICE WAS SOLN WITH WINDS THAT LOOKED LIKE LATEST
ECMWF. GIVEN FAVORABLE OVER-WATER INSTABILITY AND EXPECTED NORTHERLY
WINDS...INCREASED POPS TO LIKELY OVR NORTH WIND SNOW BELTS IN FAR
WEST AND NORTH CENTRAL UPR MI. SEVERAL INCHES OF SNOW SEEMS POSSIBLE
THURSDAY NIGHT INTO FRIDAY...AND WILL CONTINUE TO MENTION THIS IN
THE HAZARDOUS WEATHER OUTLOOK.
IN THE EXTENDED...AGREEMENT IN OVERALL IDEA THAT FIRST PORTION OF
THE WEEKEND WILL BE DOMINANTED BY LINGERING COLD AIRMASS /H85 TEMPS
AROUND -20C/ THAT MOVES IN LATE THIS WEEK. LK EFFECT IN NORTH TO
NORTHWEST FLOW AREAS FRIDAY AND FRIDAY NIGHT WILL DIMINISH ON
SATURDAY AS WINDS TURN MORE WESTERLY AHEAD OF YET ANOTHER COLD
FRONT. BOTH GFS/ECMWF POINT TO CENTER OF POLAR VORTEX WITH H85 TEMPS
NEAR -30C TO FINALLY COME SOUTH INTO GREAT LAKES BY SUNDAY. VORTEX
IS QUITE COMPACT THOUGH AND IT SEEMS DIFFICULT AT BEST TO FCST WHERE
THE CORE OF COLDEST AIR WILL ACTUALLY TRAVEL. GFS IS FARTHER WEST
AND WOULD RESULT IN MIN TEMPS ON SATURDAY NIGHT WELL BLO ZERO IN THE
CNTRL AND EAST. ECMWF IS FARTHER EAST WITH THE VORTEX. SEEMS LIKE
TREND THIS WINTER OF ONLY GLANCING BLOWS OF COLDER AIR OVR UPR LAKES
WOULD SUPPORT THE ECMWF IDEA.
LK EFFECT MAY KICK UP AGAIN LATE IN THE WEEKEND...THOUGH LOW
INVERSION HEIGHTS AND VERY DRY LOW-LEVELS WILL KEEP ACCUMS IN CHECK.
BLEND OF MODELS WORKS FOR NOW...WHICH RESULTED IN SLIGHT CHANCES FOR
SNOW SHOWERS. DUE TO FINE NATURE OF CRYSTALS/NEEDLES IN SUCH A COLD
AIRMASS...THE MAIN IMPACT FM THE SNOW SHOWERS WOULD BE REDUCED
VSBY...ESPECIALLY WITH SOME WIND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z EARLY WEDNESDAY MORNING)
ISSUED AT 427 AM EST TUE FEB 7 2012
LIGHT LES AND MVFR CIGS WILL CONTINUE INTO TUE MORNING WITH N-NE
FLOW ACROSS THE AREA. UPSLOPE NNE FLOW WILL FAVOR KSAW FOR LOWER
VSBYS IN LES...BUT GENERALLY EXPECT VSBYS AT KSAW TO STAY IN THE
MVFR RANGE. DIMINISHING TREND TO LAKE EFFECT SHSN AND IMPROVEMENT IS
EXPECTED AT ALL SITES BY LATE TUE MORNING AS FLOW BECOMES
INCREASINGLY ANTICYCLONIC...THE SUBSIDENCE INVERSION LOWERS AND
DRIER AIR ARRIVES. EXPECT CLEARING FROM THE WEST BY MID-LATE TUE
AFTERNOON AS FLOW BACKS MORE NW WITH VFR CONDITIONS TO CONTINUE INTO
TUE EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EST TUE FEB 7 2012
SINCE THE N WINDS EARLY THIS MORNING ARE NOT AS STRONG AS EARLIER
ANTICIPATED...GENERALLY NO HIER THAN 25 KT...CANX THE PREVIOUS HEAVY
FREEZING SPRAY WARNING THAT WAS IN EFFECT UNTIL 15Z FOR PORTIONS OF
CENTRAL LK SUP. WINDS TODAY WILL DIMINISH FURTHER WITH THE ARRIVAL
OF A HI PRES RDG/WEAKER PRES GRADIENT. ONCE THE HI CENTER DRIFTS
FARTHER S TONIGHT...A STRONGER W WIND UP TO 30 KTS WILL DEVELOP LATE
UNDER THE SHARPENING PRES GRADIENT BETWEEN THE RETREATING HI AND
FALLING PRES ACROSS ONTARIO. GRADIENT TIGHTENS FURTHER ON WEDNESDAY
WHICH COULD RESULT IN A FEW WESTERLY GALE GUSTS. WINDS BRIEFLY
DIMINISH LATER WEDNESDAY NIGHT INTO THURSDAY MORNING...BUT THEN
VEER NORTH AND INCREASE TO 30 KTS LATE THURSDAY AFTERNOON INTO
THURSDAY NIGHT. HEAVY FREEZING SPRAY IS POSSIBLE THURSDAY NIGHT OVER
MUCH OF THE LAKE. EXPECT NORTH WINDS TO DIMINISH BLO 25 KTS LATER
FRIDAY WITH WINDS STAYING BLO 25 KTS THROUGH THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...VOSS
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
328 AM CST TUE FEB 7 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY...
THE BIGGEST CHALLENGE FOR TODAY WILL BE THE EVOLUTION OF THE STRATUS
DECK ACROSS WESTERN NORTH DAKOTA. THE HRRR MODEL AS HAS BEEN THE
CASE OVER THE PAST FEW DAYS SEEMS TO HAVE TO THE BEST HANDLE ON THE
STRATUS...AND KEEPS IT IN PLACE WEST OF HIGHWAY 83 THROUGH THE
AFTERNOON WHICH SEEMS REASONABLE GIVEN THE LACK OF MIXING WITH
SURFACE HIGH PRESSURE IN PLACE. DO EXPECT A SLOW EROSION OF THE
EASTERN PERIPHERY OF THE STRATUS THROUGH THE AFTERNOON...AND FOR NOW
HAVE SKIES CLEARED ACROSS THE WEST BY 00 UTC. HOWEVER...UNCERTAINTY
IS HIGH...AND IT IS ENTIRELY POSSIBLE THAT AT LEAST A PORTION OF THE
DECK MAY SURVIVE PAST 00 UTC. THE STRATUS SHOULD HOLD HIGH
TEMPERATURES NEAR 20 ACROSS THE WEST...WITH MID 20S FOR HIGHS ACROSS
THE CENTRAL OUTSIDE OF THE STRATUS. ISOLATED FLURRIES THROUGH THE
DAY ARE POSSIBLE UNDER THE STRATUS DECK.
WITH CLEAR SKIES ACROSS THE CWA TONIGHT...ASSUMING ALL THE
STRATUS ERODES...AND LIGHT WINDS WITH SURFACE HIGH PRESSURE IN
PLACE...GOOD RADIATIONAL COOLING IS EXPECTED WITH LOWS MAINLY IN
THE SINGLE DIGITS ABOVE ZERO...WITH A FEW SUBZERO READINGS
POSSIBLE AT THE FAVORED COOLER LOCATIONS ACROSS WESTERN AND
CENTRAL NORTH DAKOTA. WEDNESDAY LOOKS TO BE ANOTHER MILD FEBRUARY
DAY WITH SOUTHWEST RETURN FLOW ESTABLISHING ITSELF AS THE
AFOREMENTIONED HIGH PRESSURE SYSTEM PROPAGATES INTO THE CENTRAL
PLAINS. WITH THE LACK OF SNOW COVER...BIAS CORRECTED GUIDANCE
WHICH IS WARMER THAN THE DETERMINISTIC AND STATISTICAL GUIDANCE
SUITE IS FAVORED WHICH WOULD SUGGEST WIDESPREAD HIGHS IN THE UPPER
30S FOR WEDNESDAY WITH GREATER MIXING GIVEN THE BROWN GROUND.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY.
FORECAST PROBLEM IN THE LONG TERM PERIOD WILL BE TEMPERATURES.
LITTLE IF ANY SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE
WEEK...WITH ONLY A SMALL INCREASE IN PRECIPITATION CHANCES EARLY
NEXT WEEK.
MODELS ARE INDICATING THE BLOCKING PATTERN OVER THE CONTINENTAL U.S.
THE PAST SEVERAL DAYS WILL COME TO AN END. THE MAIN FORECAST PROBLEM
WILL BE EXACTLY HOW AND WHEN THIS TAKES PLACE. THE REX BLOCK OVER
THE WESTERN U.S. WILL CONTINUE TO WEAKEN/DIMINISH EARLY IN THE
FORECAST PERIOD...ALLOWING THE POLAR VORTEX TO BRING ANOTHER SHOT OF
COLDER AIR TO THE REGION LATER THIS WORK WEEK. THEN AS RIDGING TO
OUR WEST BREAKS DOWN AMID STRONG ZONAL FLOW FROM THE PACIFIC THE
POLAR VORTEX WILL LIFT WELL NORTHEAST AS QUASI-ZONAL PROGRESSIVE
FLOW DEVELOPS BY EARLY NEXT WEEK. WILL UTILIZE A GENERAL BLEND AS
MODELS ARE SHOWING ABOVE NORMAL AGREEMENT EARLY IN THE LONG TERM
PERIOD. LATER ON AS WE FIRST SEE ANOTHER SHOT OF COLD AIR BEFORE THE
VORTEX GETS DISLODGED...MODEL SPREAD INCREASES SIGNIFICANTLY AND A
CONTINUATION OF THE CONSENSUS BLEND SEEMS REASONABLE.
AS FAR AS THE DETAILS...NORMAL TO ABOVE NORMAL TEMPERATURES
WEDNESDAY NIGHT...THEN COLD AIR ARRIVES ON THURSDAY WITH HIGHS
MAINLY IN THE TEENS FAR NORTH...BUT STILL HOLDING INTO THE LOWER
30S SOUTH. SOME SUB-ZERO LOWS POSSIBLE NORTH CENTRAL THURSDAY
NIGHT...WITH COLD TEMPERATURES REMAINING OVER THE NORTHEAST HALF OF
THE CWA FRIDAY...WHILE SEASONABLE HIGHS REMAIN OVER THE SOUTHWEST.
THEN A SLOW MODERATION IN TEMPERATURES IS IN STORE OVER THE WEEKEND
AND INTO EARLY NEXT WEEK.
AS WE ENTER A MORE PROGRESSIVE QUASI-ZONAL FLOW...WE WILL SEE AN
INCREASE IN DISTURBANCES TRAVERSING THE AREA EARLY NEXT WEEK. AT
THIS TIME...NOTHING LOOKS TO BE SIGNIFICANT WEATHER MAKER.
&&
.AVIATION...
HIGH PRESSURE OVER SOUTHERN SASKATCHEWAN AND MANITOBA
WILL DROP SOUTH ACROSS THE AREA TODAY. THIS WILL BRING VFR
CONDITIONS TO THE AREA. THE EASTERN TAF SITES OF MINOT AND JAMESTOWN
WILL LIKELY SEE VFR CONDITIONS THROUGH THE PERIOD...WHILE WILLISTON
AND DICKINSON WILL SEE MVFR-IFR CLOUDS LINGER THROUGH AT LEAST MID
MORNING BEFORE DISSIPATING. IN ADDITION...MODELS MAY BE CLEARING OUT
THE WEST TOO QUICKLY AND WILL KEEP LOWER STRATUS IN THE WEST LONGER
THAN MODELS INDICATE. ONCE THE STRATUS DOES DISSIPATE...VERY DRY AIR
ALOFT WILL KEEP VFR CONDITIONS THROUGH THE REMAINDER OF THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PJA
LONG TERM/AVIATION....TWH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
112 AM EST TUE FEB 7 2012
.SYNOPSIS...
HIGH PRESSURE TUESDAY. A COLD FRONT PASSES WITH AN UPPER
DISTURBANCE TO PROVIDE WINTER PRECIPITATION TUESDAY NIGHT AND
WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATED...
AREAS OF LOW STRATUS LINGERING ACROSS THE NORTHERN MTNS AS OF 06Z.
THESE SHOULD DISSIPATE BY 09Z OR SO AS DRIER AIR WORKS IN THRU THE
COLUMN. OTHERWISE WILL BE WATCHING LOW STRATUS DECK MOVING SE INTO
OH. THIS SEEMS BE MARKED BY A WIND SHIFT TO MORE NW IN LWR LVLS. HI
RES LCL MDLS MDLS SEEM TO HAVE A MUCH BETTER HANDLE ON THIS AS NAM
AND GLOBAL MDLS ARE TOO SLOW AND NW WITH THIS. WILL USE RUC AND
WRF MDLS FOR TIMING WITH IT POISED TO MOVE INTO
PERRY...MORGAN...VINTON CO 10-12Z BEFORE PUTTING ON THE BRAKES IN
ITS SE ADVANCEMENT.
LAMP GUIDANCE IS INSISTING ON ADVECTING LWR DWPTS ACROSS THE NORTH
THRU MORNING WITH BL WINDS SLOWLY RELAXING. WILL KEEP MOST OF THE
FG IN RVR VALLEYS CENTRAL AND SOUTHERN WV AND SW VA...MUCH WHERE
IT WAS YESTERDAY.
PREVIOUS DISCUSSION BELOW...
WEAK UPPER LOW CUTS THROUGH THE CWA THIS EVENING. BEST MOISTURE
AND DYNAMICS POSITIONED SOUTH OF KCRW. LATEST VIS IMAGERY SHOW LOW
LEVEL CLOUD DECK IS INCHING TOWARD THE WV-KY LINE AS OF 17Z. MADE
MINIMAL ADJUSTMENTS TO POPS AND CLOUD THROUGH THIS EVENING.
BROUGHT CLOUDS A LITTLE FURTHER NORTH AND WEST. MAIN FORECAST
PROBLEM WILL BE TIMING AND PLACEMENT OF STRATUS DECK...AND THE
INTERPLAY WITH OVERNIGHT MINS AND TUESDAY MAX TEMPS. THE CLOUD
BOUNDARY SHOULD BE FAIRLY SHARP. SYSTEM SHOULD EXIT AFTER 6Z
LEAVING WEAK HIGH PRESSURE IN ITS WAKE.
SLIGHT CLEARING FOR TUESDAY MORNING AS NEXT WAVE APPROACHES.
MODELS HAVE BACKED OFF ON INCREASING CLOUDS FROM THE WEST ON
TUESDAY SO SLOWED TIMING OF INCREASING CLOUDS TUESDAY AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
MODELS INDICATE TWO UPPER LEVEL DISTURBANCES WILL PUSH SOUTHEAST
ACROSS THE AREA...FIRST ONE FROM TUESDAY NIGHT INTO WEDNESDAY AND
ANOTHER ON THURSDAY.
LATEST RUNS SUGGEST ONSET OF ANY MEASURABLE PRECIP WILL BE SLOWER
THAN PREVIOUSLY THOUGHT AND GRIDS HAVE BEEN TWEAKED TO REFLECT THIS
THINKING. WHILE THERE ARE TIMING DIFFERENCES...ALL MODELS...AS
WELL AS HPC...INDICATE MEASURABLE PRECIP WILL OCCUR ACROSS PORTIONS
OF THE REGION TUESDAY NIGHT INTO WEDNESDAY. WITH THIS IN
MIND...HAVE BUMPED POPS UP TO LIKELY.
WITH SURFACE HIGH PRESSURE BUILDING IN FROM THE WEST...PRECIP
CHANCES SHOULD END ACROSS THE LOWLANDS LATE WEDNESDAY INTO
THURSDAY. COMBINATION OF NEXT SHORTWAVE...SUFFICIENT LOW-LEVEL
MOISTURE AND NORTHWEST WINDS...SHOULD KEEP PRECIPITATION CHANCES IN
THE MOUNTAINS WEDNESDAY NIGHT INTO THURSDAY.
MAV/MET GUIDANCE FOR LOWS IS CLOSE TO OUR FORECASTED NUMBERS...SO
ONLY TWEAKED MADE. MAV/MET NUMBERS FOR HIGHS ON WEDNESDAY ARE
WARMER THAN PREVIOUS NUMBERS...BUT MAY BE A LITTLE TOO WARM BECAUSE
OF CLOUDS AND PRECIP. HAVE TWEAKED NUMBERS UP IN A FEW LOCATIONS...
BUT DID NOT BITE OFF ON THE WARMER MAV NUMBERS.
USED A BLEND OF MEX NUMBERS AND HPC VALUES FOR HIGHS ON THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
OPERATIONAL MODELS ADVERTISING A CLIPPER SYSTEM TO COME THROUGH THE
FIRST PART OF THE WEEKEND. QPF AMOUNTS WILL GENERALLY BE ON THE
LIGHT SIDE...WITH SOME SNOW EXPECTED...BUT SYSTEM WILL BE A QUICK
MOVER. COULD LEAVE SOME LINGERING UPSLOPE ON THE BACK SIDE THROUGH
THE DAY SATURDAY AND EARLY INTO SATURDAY NIGHT. THIS SYSTEM WILL
ALSO SERVE TO USHER IN A MORE WINTER LIKE AIRMASS AS 925MB
TEMPERATURES DROP TO AROUND 10C BELOW ZERO. WILL EXPECT A CLEAR
NIGHT SATURDAY NIGHT...AND WILL SEE MOST LOCATIONS DROPPING INTO THE
TEENS WHILE MOUNTAIN VALLEYS ARE IN THE HUNT FOR SINGLE DIGITS. HIGH
PRESSURE SETTLES IN FOR THE REMAINDER OF THE LONG TERM WITH
TEMPERATURES SLOW TO REBOUND THROUGH THIS PERIOD.
&&
.AVIATION /06Z TUESDAY THROUGH 06Z WEDNESDAY/...
AREAS OF LOW STRATUS ACROSS THE NORTHERN MTNS WILL DISSIPATE
09-10Z. SOME MVFR CIGS POSSIBLE FOR KEKN UP TO 09Z.
OTHERWISE A CLEAR SKY WILL PREVAIL FOR MOST THRU 12Z. EXCEPTION BEING
ACROSS PORTIONS OF SE OH WHERE A LOW STRATUS DECK...MARKED BY A
WIND SHIFT IN LWR LEVELS WILL ADVANCE 10-12Z BEFORE HALTING
PROGRESS S AND E.
DRIER AIR ADVECTING IN FORM OF LWR DWPTS ACROSS THE NORTH WILL
TEND TO MITIGATE FG DEVELOPMENT THRU 12Z. FURTHER S...HIGHER DWPTS
ALONG WITH A RELAXING BL WIND SHOULD ALLOW FOR RVR VALLEY FG TO
FORM ONCE AGAIN EARLY THIS MORNING. CENTRAL/SOUTHERN WV AND SW VA
STAND ONCE AGAIN FOR DENSE FG. SHOULD BE A LITTLE LATER FORMING
THAN YESTERDAY DUE SOME RESIDUAL BL WINDS. FOR TAF SITES...KEPT LIFR FZFG
CONFINED TO KCRW...WITH IFR VSBY POSSIBLE OVER TOWARD KHTS.
ANY FOG ACROSS CENTRAL/SOUTHERN WV AND SW VA WILL QUICKLY LIFT AND
SCT OUT FOR VFR CONDITIONS THROUGH THE REST OF THE PERIOD.
WILL SEE LITTLE PROGRESS IN ADVANCEMENT OF STRATUS ACROSS SE
OH...UNTIL AFTER 18Z WHEN SOME MVFR CIGS MAY SNEAK INTO KPKB.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING AND INTENSITY OF FOG COULD VARY OVER CENTRAL
AND SOUTHERN AREAS. TIMING AND EXTENT OF LOW STRATUS OVER SE OH
COULD VARY THRU 18Z.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE TUE 02/07/12
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H H H L L L L L L H H H
HTS CONSISTENCY H H H L L L L M L H H H
BKW CONSISTENCY H H H L L H H H H H H H
EKN CONSISTENCY H M M L L L L L L H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z WEDNESDAY...
IFR POSSIBLE IN THE MOUNTAINS DUE TO SNOW SHOWERS LATE TUESDAY NIGHT
INTO WEDNESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...RPY/30
NEAR TERM...KMC/30
SHORT TERM...JSH
LONG TERM...26
AVIATION...30
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
211 AM CST TUE FEB 7 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
MID/UPPER LEVEL TROUGH ACROSS THE NORTHERN GREAT LAKES REGION IS
EXPECTED TO DROP SOUTH AS AN UPPER LOW OVER THE CENTRAL ROCKIES
PUSHES EAST. MAIN PORTION OF THE NORTHERN TROUGH HEADS EAST TONIGHT
AS THE WESTERN SHORTWAVE MOVES ACROSS KENTUCKY. WEAK 700 MB UPWARD
MOTION MAINLY THIS MORNING THEN WEAKENING BY EVENING. RELATIVE
HUMIDITY AT 700 MB IS BELOW 50 PCT. 850 MB RH INCREASES AS IT DROPS
SOUTH ACROSS SOUTHERN WISCONSIN...REACHING ABOVE 90 PCT. 00Z NAM IS
NOT AS COLD AT 850 MB AS PRIOR MODELS. -8 DEG C DROPS DOWN INTO
NORTHERN PORTIONS OF THE FORECAST AREA BY 12Z AND NEARS THE ILLINOIS
BORDER BY 18Z. HOWEVER BY THE TIME DELTA T VALUES BECOME FAVORABLE
FOR LAKE SNOW...LOW LEVEL MOISTURE IS DECREASING FROM THE NORTH.
HOWEVER MOISTURE EXTENDS TO NEAR 5 THSD FT AND DESPITE MARGINAL
LAPSE RATES...THERE IS STILL THE POSSIBILITY FOR A PERIOD OF LAKE
SNOW.
NO ORGANIZED SNOW BAND ON THE HRRR AND 12 HOUR PRECIP QPF VALUES ARE
DOWN TO 0.05 INCHES ON THE NAM AND 0.07 ON THE HRRR. WILL THEREFORE
GO WITH MAINLY AN INCH OR SO OF LAKE EFFECT.
LATER TONIGHT THE HIGH PRESSURE RIDGE MOVES INTO SOUTHERN WISCONSIN
WITH DIMINISHING WINDS. NAM HAS NO QPF AS LOW LEVELS CONTINUE TO
DRY AND LOW LEVEL LAPSE RATES DECREASE TO AROUND 7.5 C/KM BELOW 900
MB.
.WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...HIGH
HIGH PRESSURE WILL SIT JUST TO THE SOUTHWEST OF THE FORECAST AREA
WEDNESDAY AND WEDNESDAY NIGHT...BEFORE BEGINNING TO SHIFT SOUTH
THURSDAY AHEAD OF APPROACHING LOW PRESSURE. HIGH CLOUDS ARE EXPECTED
TO DECREASE WEDNESDAY MORNING...WITH SKIES BECOMING MOSTLY SUNNY
BY AFTERNOON. MOSTLY CLEAR SKIES SHOULD HOLD ON THROUGH MUCH OF
THE DAY THURSDAY...WITH CLOUDS POSSIBLY MOVING IN FROM THE
NORTHWEST IN THE AFTERNOON AS THE SYSTEM DRAWS NEAR.
LEANED TOWARD THE MILDER END OF MODELS WED/THU WITH THE LACK OF
SNOW COVER AND THE OVERALL RESULTANT MODEL COLD BIAS THIS WINTER.
.THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE...MEDIUM
WENT WITH A SLIGHT CHANCE FOR SNOW ACROSS THE EAST THURSDAY NIGHT
AND FRIDAY AS THE SFC COLD FRONT AND UPPER TROUGH SWING THROUGH.
KEPT POPS ON THE LOW END...AS THE NAM IS THE MOST AGGRESSIVE WITH QPF
BUT IS ONLY SATURATED UP TO AROUND 10 KFT. CURRENT FRONT TIMING
WOULD RESULT IN TEMPS FALLING THROUGH MUCH OF THE DAY AS COLDER AIR
ADVECTS IN BEHIND THE FRONT.
.SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
STILL EXPECTING THE WEEKEND INTO EARLY NEXT WEEK TO BE DRY. SHOULD
SEE BELOW NORMAL TEMPS BEHIND THE DEPARTING SYSTEM
SATURDAY...WARMING TO NEAR NORMAL FOR SUNDAY AND MONDAY.
&&
.AVIATION/12Z TAFS/...
MVFR CIGS/VSBYS BEHIND COLD FRONT EXITING SOUTHERN WISCONSIN. IFR
CIGS SOUTH AND SOUTHWEST OF MADISON EARLY THIS MORNING. VSBYS
SHOULD IMPROVE TO VFR AS COLDER AND DRIER LOW LEVEL AIR MOVES IN.
SOME LAKE EFFECT SNOW POSSIBLE THIS MORNING AND INTO THE AFTERNOON.
HOWEVER 850 MB TEMPS TO LAKE SURFACE TEMPERATURES ARE MARGINAL AND
BY THE TIME THEY COOL DRIER AIR BEGINS TO FILTER IN FROM THE NORTH.
HOWEVER MOISTURE EXTENDS TO NEAR 5 THSD FT AND DESPITE MARGINAL
LAPSE RATES...THERE IS STILL THE POSSIBILITY FOR A PERIOD OF LAKE
SNOW.
&&
.MARINE...A SMALL CRAFT ADVISORY IS IN EFFECT INTO TONIGHT. BRISK
NE WINDS AND ASSOCIATED HIGH WAVES WILL DEVELOP. THE WINDS WILL
BEGIN TO SUBSIDE THIS EVENING...BUT DUE TO THE NORTHEAST
FETCH...HIGH WAVES WILL LINGER A LITTLE LONGER.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 3 AM CST WEDNESDAY FOR LMZ645-646.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643-644.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
WEDNESDAY THROUGH MONDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1149 PM CST MON FEB 6 2012
.SHORT TERM...OVERNIGHT
941 PM CST MON FEB 6 2012
THE 07.00Z NAM/WRF AND LATEST RUC SOUNDINGS SHOW GENERALLY DRY AIR
BELOW 800 FEET WHEN THE BEST LIFT IS MOVING INTO THE REGION.
LOOKING AT THE TOP OF SOUNDINGS...THE TEMPERATURES ARE COLD ENOUGH
FOR SOME ICE CRYSTALS INTRODUCTION. THEREFORE IF THERE IS
PRECIPITATION IT WOULD BE IN THE FORM OF FLURRIES...THUS...REMOVED
THE FREEZING DRIZZLE FROM THE FORECAST. WITH THERE BEING NO REPORTS OF
PRECIPITATION UPSTREAM...BEGINNING TO WONDER IF THE MODELS ARE
OVERDOING THE MOISTURE A BIT. HOWEVER NOT CONFIDENT ENOUGH TO
REMOVE THE FLURRIES FROM THE FORECAST AT THIS TIME.
ALSO BEEN NOTICING THAT THE TEMPERATURES ARE RISING AS THE CLOUDS
MOVE INTO THE AREAS FROM THE NORTH. THE NAM/WRF SEEMS TO HAVE A
GOOD HANDLE ON THIS...SO TRENDED THE HOURLY GRIDS THAT WAY. IT DID
NOT MAKE A HUGE CHANGE IN THE FORECAST MINIMUM TEMPERATURES...BUT
THE HOURLY TEMPERATURE TRACES WILL BETTER REFLECT REALITY.
.LONG TERM...FRIDAY THROUGH MONDAY
252 PM CST MON FEB 6 2012
06.12Z ECMWF AND GFS BOTH SHOW ANOTHER SHOT OF COLD AIR DROPPING
INTO THE REGION ON FRIDAY BEHIND THE AFOREMENTIONED COLD FRONT AS
HIGH PRESSURE BUILDS ACROSS THE PLAINS. THIS WILL KEEP TEMPERATURES
AT OR BELOW NORMAL FOR SATURDAY INTO SUNDAY WITH DRY WEATHER. HOW
MUCH MODERATION OCCURS SUNDAY AND MONDAY ARE THE BIG DIFFERENCES IN
THE MODELS. GFS QUICKER IN TAKING TROUGH OVER THE AREA EASTWARD AND
BUILDING THE RIDGE IN. HENCE 850MB TEMPERATURES CLIMB TO AROUND 0
MONDAY...WILE THE ECMWF KEEPS THE COLDER AIR ENTRENCHED WITH 850MB
TEMPERATURES AROUND -8 CELSIUS. BOTH DO GENERATE A LITTLE
PRECIPITATION ON THE BACK SIDE OF THE HIGH MONDAY...BUT TYPE IS A
PROBLEM AT THIS POINT BASED ON TEMPERATURES. THUS WENT WITH A CHANCE
OF RAIN OR SNOW.
&&
.AVIATION...THROUGH 06Z WEDNESDAY
1140 PM CST MON FEB 6 2012
AT 11 PM...COLD FRONT EXTENDED FROM IOWA FALLS...IOWA /KIFA/ TO
MILWAUKEE. WINDS SOUTH OF THIS FRONT WERE WESTERLY. MEANWHILE TO
ITS NORTH...THE WINDS WERE NORTH AND NORTHEAST. THESE WERE HELPING
BRINGING SOME LAKE INDUCED CLOUDS INTO THE FORECAST AREA. CEILINGS
ARE MAINLY VFR SOUTH OF INTERSTATE 94...AND FROM 1500-2500 FEET TO
THE NORTH OF THIS CORRIDOR. THINKING THAT THE CEILINGS WILL
GRADUALLY BECOME MVFR BETWEEN 0730Z AND 0900Z AT BOTH TAF
SITES...AND REMAIN THERE THROUGH THE EARLY AFTERNOON.
WITH THE MOISTURE LOOKING A BIT MORE SHALLOWER THAN WHAT THE
SOUNDINGS ARE INDICATING AND NO REPORTS OF SNOW UPSTREAM...REMOVED
THE MENTION OF SNOW IN THE TAFS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
252 PM CST MON FEB 6 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...RABERDING
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1028 PM MST MON FEB 6 2012
.AVIATION...06Z TAFS
IFR CONDITIONS EXPECTED TO CONTINUE THROUGH LATE MORNING FOR MOST
LOCATIONS EAST OF THE LARAMIE RANGE IN NORTHEASTERLY UPSLOPING
WINDS AND LIGHT SNOW/SNOW FLURRIES. LATEST HRRR GUIDANCE SHOWING
LOW CLOUD DECK STARTING TO BREAK UP AFTER THE 13-14Z TIMEFRAME.
SINCE THIS GUIDANCE HAS BEEN SO GOOD RECENTLY...DECIDED TO FOLLOW
ITS GUIDANCE.
CLAYCOMB
&&
PREV DISCUSSION... /ISSUED 326 PM MST MON FEB 6 2012/
SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...EARLY AFTERNOON
WATER VAPOR/SREF 500 MB COMPOSITE IMAGERY SHOWED THE BROAD UPPER
CYCLONIC CIRCULATION OVER COLORADO MOVING SLOWLY EASTWARD. SCATTERED
SNOW SHOWER ACTIVITY WAS ACCOMPANYING THIS FEATURE...MAINLY WEST
OF THE FRONT RANGE. THE OTHER FEATURE SEEN IN VISIBLE SATELLITE WAS
AN EXPANSIVE LOW CLOUD DECK MOVING SOUTHWARD THROUGH THE DAKOTAS
AND CENTRAL WYOMING BEHIND A SURFACE COLD FRONT. THIS FRONT WAS
ANALYZED FROM SOUTHERN SOUTH DAKOTA WESTWARD TO SOUTH OF DOUGLAS
AND CASPER THEN INTO NORTHWEST WYOMING. WINDS SHIFTED TO THE NORTH
AND INCREASED TO 20 TO 30 MPH AND GUSTY BEHIND THE FRONT. LIGHT SNOW
WAS OBSERVED AT BUFFALO AND SHERIDAN. TEMPERATURES AT 2 PM RANGED
FROM 45 AT CHADRON TO 21 AT VEDAUWOO.
SHORT RANGE MODEL TRENDS GENERALLY REMAIN CONSISTENT WITH THE GOING
FORECAST. THE 12Z GFS/ECMWF/GEM/NAM OPEN THE CLOSED UPPER LOW OVER
NORTHEAST COLORADO INTO A WAVE LATER TONIGHT...THEN EJECT IT EASTWARD
ACROSS THE PLAINS TUESDAY AND MIDWEST TUESDAY NIGHT. MEANWHILE...A
FAIRLY POTENT SHORTWAVE TROUGH ALONG THE NORTHERN TIER DROPS
SOUTHEAST THROUGH THE DAKOTAS AND MISSOURI VALLEY DURING THE SAME
TIME PERIOD. THE SURFACE COLD FRONT PRECEDING THE TROUGH WILL EXIT
THE CWA EARLY THIS EVENING. MOISTURE WRAPPING AROUND THE COLORADO LOW
AND WEAK UPSLOPE POST-FRONTAL FLOW WILL RESULT IN WIDESPREAD LIGHT
SNOW TONIGHT. ACCUMULATIONS WILL RANGE FROM ONE TO TWO INCHES FOR THE
LARAMIE AND SNOWY RANGES...WITH LESS THAN AN INCH ELSEWHERE. GUSTY
NORTHERLY WINDS THIS EVENING WILL DIMINISH AFTER MIDNIGHT...AND BE
LIGHT AND VARIABLE ON TUESDAY. THE SNOW WILL LINGER OVER THE NORTHERN
LARAMIE RANGE TUESDAY MORNING...THEN DIMINISH TUESDAY AFTERNOON AS
THE UPPER SUPPORT EXITS TO THE EAST. STRONG LOW LEVEL COLD AIR
ADVECTION (700 MB TEMPERATURES -14 TO -16C) AND CONSIDERABLE
CLOUDINESS WILL KEEP HIGH TEMPERATURES WELL BELOW NORMAL TUESDAY WITH
HIGHS IN THE TEENS AND 20S. CLEARING SKIES AND LIGHT WINDS WILL
PROVIDE EXCELLENT RADIATIONAL COOLING TUESDAY NIGHT WITH LOWS
DROPPING INTO THE SINGLE DIGITS AND LOWER TEENS. SOME OF THE VALLEY
LOCATIONS MAY REGISTER 0 TO 5 BELOW ZERO. FORTUNATELY THE BRUNT OF
THE COLDER AIRMASS ASSOCIATED WITH THE 1040 MB SURFACE HIGH PRESSURE
SYSTEM WILL AFFECT THE DAKOTAS AND UPPER MIDWEST. WEAK SURFACE AND
UPPER LEVEL RIDGING TO THE WEST WILL ALLOW THE WINDS TO BACK TO THE
WEST-NORTHWEST WEDNESDAY... WHICH WILL MODERATE TEMPERATURES ABOUT 10
DEGREES FROM TUESDAY/S HIGHS. BY WEDNESDAY AFTERNOON...A WEAK SURFACE
TROUGH WILL DEVELOP OVER EASTERN WYOMING. THE PRESSURE GRADIENT
ACROSS SOUTHEAST WYOMING TIGHTENS A BIT RESULTING IN BREEZY WEST-
SOUTHWEST WINDS ALONG AND WEST OF THE LARAMIE RANGE. IT WILL BE
MILDER WEDNESDAY NIGHT WITH LOWS MAINLY IN THE TEENS.
LONG TERM...THURSDAY THROUGH NEXT MONDAY...LONG RANGE MODELS
CONTINUE TO SHOW TRANQUIL CONDITIONS AND COOLER THAN NORMAL
TEMPERATURES LATE THIS WEEK...BUT ARE THEN INCONSISTENT AND IN
POOR AGREEMENT FOR THIS WEEKEND AS A SERIES OF UPPER LEVEL TROUGHS
MOVE ACROSS THE NORTHERN AND CENTRAL ROCKIES. MODELS AS WELL AS
THE ENSEMBLE FORECASTS ARE ALL TRENDING FURTHER EAST WITH THE
POTENTIAL ARCTIC OUTBREAK ACROSS THE GREAT PLAINS STATES FOR
FRIDAY...SO KEPT TEMPERATURES NEAR OR SLIGHTLY BELOW NORMAL. THE
ECMWF AND GEM ON THE OTHER HAND SHOW THIS ARCTIC FRONT HOLDING OFF
FOR ANOTHER DAY AND PUSHING INTO THE HIGH PLAINS OF WESTERN
NEBRASKA EARLY IN THE WEEKEND. BOTH MODELS SHOW THIS FRONTAL
BOUNDARY STALLING OVER THE HIGH PLAINS EAST OF THE LARAMIE RANGE
AS A WEAK UPPER LEVEL TROUGH QUICKLY MOVES EASTWARD FROM THE
PACIFIC NORTHWEST. WITH AMPLE LLVL CONVERGENCE ALONG THE
FRONT...UPSLOPE FLOW...AND COLD TEMPS...BOTH THE GEM AND ECMWF
SHOW SOME LIGHT SNOW MAINLY EAST OF THE LARAMIE RANGE THROUGH
SATURDAY NIGHT. INCREASED POP OVER THE AREA BUT KEPT MOST OF THE
FORECAST DRY FOR NOW SINCE THERE IS CONSIDERABLE DIFFERENCES
BETWEEN MODEL SOLUTIONS AS THE GFS SHOWS DRY WEATHER AS A RIDGE
ALOFT MOVES OVER THE CONTINENTAL DIVIDE. CONSIDERABLE DIFFERENCES
BETWEEN ENSEMBLE FORECASTS...SO THERE IS LIMITED CONFIDENCE IN
THIS WEEKENDS FORECAST. IF ANYTHING...MORE CONFIDENCE IN NEXT
WEEKS FORECAST WITH ALL MODELS SHOWING A LONG WAVE UPPER LEVEL
TROUGH SETTLING OVER MOST OF THE CENTRAL AND EVEN WESTERN UNITED
STATES AS MUCH COLDER AIR PUSHES SOUTH OVER THE INTER MOUNTAIN WEST
AND GREAT PLAINS STATES. AS THIS TIME...IT APPEARS THERE IS A
GREATER CHANCE FOR PRECIPITATION AND SNOWFALL EARLY NEXT WEEK AS
NUMEROUS PACIFIC STORM SYSTEMS PUSH ONSHORE AND ACROSS THE
NORTHERN AND CENTRAL ROCKIES.
&&
FIRE WEATHER...NO FIRE WEATHER CONCERNS FOR THE NEXT FEW DAYS. A
COLD FRONT WILL MOVE SOUTH THROUGH THE DISTRICTS BY EARLY THIS
EVENING...WITH GUSTY NORTH WINDS IN ITS WAKE. ALSO...AREAS OF LIGHT
SNOW WILL DEVELOP AND LINGER THROUGH TUESDAY MORNING. IT WILL BE
QUITE CHILLY TUESDAY AND TUESDAY NIGHT. ANOTHER COLD FRONT WILL MOVE
QUICKLY SOUTHEAST ACROSS THE PLAINS THURSDAY WITH ISOLATED SNOW
SHOWERS FOR THE MOUNTAINS. DRY WEATHER WITH SLOWLY MODERATING
TEMPERATURES CAN THEN BE EXPECTED THROUGH THE UPCOMING WEEKEND. THERE
WILL BE SOME BREEZY PERIODS ACROSS THE SOUTHEAST WYOMING FOR THE
LATTER HALF OF THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM/FIRE WEATHER...JAMSKI
LONG TERM/AVIATION...TJT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
437 AM MST TUE FEB 7 2012
.SHORT TERM...
(TODAY AND TONIGHT)
...COLD WEATHER THROUGH TONIGHT....
CURRENTLY...SOME LIGHT SHSN OVR OTERO AND SRN PUEBLO COUNTIES.
COULD SEE SOME MINOR ACCUMS THIS MORNING S OF HWY 50...ESPECIALLY
OVR THE RATON MESA. MODELS HAVE NOT HANDLED THIS PRECIP VERY
WELL...BUT THE RUC HAS THE SNOW PRETTY WELL DEPICTED...AND IT MOVES
MOST OF THE PRECIP OUT OF OUR AREA BY 15Z. THIS LOOKS REASONABLE
WITH THE UPPER LOW CONTINUING TO TRANSLATE INTO NE AND NW KS.
MAIN STORY TODAY WILL BE THE COLD. TEMPS HAVE NOT FALLEN MUCH OVR
THE PLAINS THIS MORN...AS OF 3 AM IT IS STILL IN THE UPPR 20 FOR
MANY SPOTS...THANKS TO THE PRECIP...LOW CLOUDS...AND WIND.
HOWEVER...WITH H7 TEMPS NOW BOTTOMING OUT IN THE MINUS 13 TO 14
RANGE...WILL NOT SEE MUCH WARMING TODAY DESPITE CLEARING SKIES THIS
AFTERNOON. A FEW SPOTS COULD RISE ABOVE FREEZING BUT OTHERWISE IT
WILL STAY IN THE UPPER 20S FOR MUCH OF THE DAY. A STRONG SURFACE
HIGH OVR THE DAKOTAS WILL CONTINUE TO SLIDE SWD THROUGH THIS
EVENING...AND THIS WILL KEEP LIGHT UPSLOPE WINDS OVER SE CO THRU
TONIGHT. DESPITE RISING TEMPS ALOFT...AS A WEAK RIDGE BUILDS BRIEFLY
OVR THE AREA...EXPECT A STRONGLY DECOUPLED BL TONIGHT...WITH TEMPS
NEARING OR DROPPING BELOW ZERO FOR SOME OF THE HIGH VALLEY COLD
SPOTS. COULD ALSO SEE TEMPS NR ZERO OVER THE LOWER ARKANSAS WITH
CLEARING SKIES AND LIGHT WINDS TONIGHT. POPS WILL REMAIN NR ZERO
THRU WED MORNING. SOME HIGH CLOUDS WILL BEGIN MOVING INTO THE SW MTS
BY SUNRISE WED...AS THE NEXT SHORT WAVE TROUGH APPROACHES FROM THE
W. ROSE
.LONG TERM...
(WEDNESDAY THROUGH MONDAY)
SLOW WARMING TREND BEGINS WEDNESDAY AHEAD OF WEAK UPPER TROUGH
SHEARING SOUTH THROUGH THE GREAT BASIN. EXPECT A FEW -SHSN TO
DEVELOP ALONG THE CONTINENTAL DIVIDE WED AFTERNOON...PERSISTING
THROUGH THE DAY THU AS SYSTEM SLOWLY DROPS SOUTH. DYNAMICS LOOK
WEAK AND MOISTURE IS LIMITED...SO NOT EXPECTING MORE THAN SCATTERED
SNOW SHOWERS WITH THE SYSTEM AT THIS POINT. MODELS HINT AT A FEW
SHOWERS OVER THE SANGRES THU MORNING...SO WILL KEEP SOME ISOLATED
POPS IN PLACE SOUTH OF LA VETA PASS. MAX TEMPS WED SHOULD WARM
10-15F VERSUS TODAY`S (TUE) NUMBERS...THEN ADD ANOTHER 3-5F THU AS
BETTER MIXING WILL LIKELY OFFSET MINOR COLD ADVECTION. FRI-SAT
LOOK MAINLY DRY AND SEASONABLE...AS WESTERN EDGE OF ARCTIC AIR
MASS OVER THE CENTRAL PLAINS STAYS EAST OF THE KS BORDER. NEW
WESTERN TROUGH TAKES SHAPE SUN...THOUGH DETAILS VARY AS 06Z GFS
TAKES SYSTEM FARTHER SOUTH AND HAS LESS IMPACT THAN RATHER SNOWY
00Z RUN. IN GENERAL...EXTENDED PROCEDURE GRIDS BEGIN A GRADUAL
TREND TOWARD COLDER/WETTER WEATHER SUN/MON...THOUGH IF TRENDS
CONTINUE...MAY NEED TO RAISE POPS/LOWER TEMPS MORE SUBSTANTIALLY IN
SUBSEQUENT FORECASTS. --PETERSEN
&&
.AVIATION...ISOLD LIGHT SHSN WILL PERSIST THROUGH THIS
MORNING...ENDING BY 13-15Z FOR AREAS VC KCOS AND KALS. AT THE
SAME TOME...N WINDS AT KCOS AND KPUB SHOULD RELAX BY MID
MORNING...AND WILL REMAIN LIGHT AND FROM THE E TO SE THROUGH TODAY
AND INTO TONIGHT. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
44/10
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1039 AM EST TUE FEB 07 2012
...Forecast Update...
Just making a few minor adjustments to the ongoing forecast, which
is pretty much on track. Low strato-cu will continue to spill
southeast into our far northern/northeastern counties. Don`t really
see this eroding on the southern edge as it did yesterday, so
although portions of s-central IN and n-central KY have sunny skies
now, we should see mostly cloudy skies by this afternoon. Just
beefed up cloud cover a bit in the grids, but overall temps/etc. on
track.
Upper disturbance approaching from the west won`t affect our CWA
until after midnight most likely. Will address that with afternoon
AFD.
Updated web forecast. No other changes made.
&&
.Short Term (Today - Wednesday)...
High pressure in place along with weak ridging aloft will keep
things dry today, although will have to deal with patchy
fog/freezing fog potential again through the morning hours. IR
satellite imagery currently shows a batch of low stratus across the
Great Lakes region to as far south as the I 74 corridor over central
and southern Indiana. HRRR has been consistent in showing these
clouds marching steadily southeast through the pre-dawn hours,
arriving near the Ohio River just after dawn. Therefore, skies
should clear in most spots with calm winds and subsident airmass.
This will lead to patchy fog formation, some of which will likely be
dense around dawn. Most likely areas will be in valleys and near
rivers and streams. With temperatures below freezing in most spots
will have to watch for slick spots. Will spend the rest of the
morning monitoring obs and issuing SPS or headline products if need
be. Right now, the only real indication of fog is over the Lake
Cumberland region.
Above mentioned status deck will likely scatter out over southern
Indiana this morning with upper level clouds beginning stream
overhead through the day. With low temperatures cooler than expected
this morning, have lowered highs a bit for this afternoon. Southern
Indiana will likely not make it out of the upper 40s with lower
level cloud cover this morning. Elsewhere, lower 50s can be expected
with mid 50s possible south.
The next weather making system will arrive after Midnight tonight as
an upper level impulse quickly ejects across the plains, absorbing
an upper low currently over NE Colorado. What may initially start
out as rain or a rain/snow mix across southern Indiana and central
Kentucky should quickly change over to snow as wet bulbing occurs
with low level saturation. Surface temperatures may stay just above
freezing in a few locations however warm layer at the surface will
be very shallow and should still support mostly snow. South of a
Bowling Green to Lake Cumberland line, precipitation type is more in
question and could end up being more rain and possibly a rain/snow
mix by dawn.
Best chances for precipitation, whether it be rain or snow, will be
from 3 AM EST to 8 AM EST early Wednesday. Will have to watch for a
moderate band of snow setting up anywhere from along and south of
the Ohio River to along and north of a Bowling Green to Lexington
line between 3 AM EST and dawn. This will occur just ahead of sharp
shortwave trough axis with frontogenesis coinciding with the left
exit region of an intensifying 100 to 120 knot upper level jet.
Models continue to indicate low amounts of QPF with this quick
hitting system, although have steadily increased amounts. Will have
to watch trends over the next 24 hours as banding does appear
possible with this setup and could produce a narrow swath of higher
QPF. That being said, ground and road temperatures should be well
above freezing with recent warm weather so do not expect any real
accumulation on these surfaces. Could see a dusting on grassy and
elevated surfaces by the daylight hours on Wednesday.
Upper level features quickly depart to the east by midday Wednesday,
however plentiful low level moisture between 1000-850 mb suggests
some flurries or sprinkles will be possible. Models are suggesting a
warm up to the low and mid 40s during the day however with overcast
skies expected, have a feeling temperatures will have trouble
getting out of the 30s. Therefore, will call for precipitation type
mostly in light snow or flurry category as any warm layer will be
confined to the surface and low level lapse rates will quickly
steepen. Could even see a few snow bursts through the day on
Wednesday as low levels edge toward a low degree of convective
instability. Again, expecting no real accumulations. Flurries or
sprinkles will linger through the day on Wednesday, along with
mostly cloudy skies.
.Long Term (Wednesday night - Monday)...
Wednesday night through Thursday night...
Main upper impulse will be exiting the area, but still expect some
residual low-level moisture to lingering Wednesday evening.
Subsidence and very shallow moist layer weigh against any precip so
no POPs in the forecast, but moisture and NW flow are sufficient
reason to hold onto a few early evening snow flurries in the eastern
tier.
Cold and dry high pressure on Thursday, with a broad, weak upper
trof overhead. MOS guidance is generally too warm in a shallow cold
air mass like this, so this forecast is more in line with the raw
model temps, with highs in the lower 40s in spite of full sunshine.
Clear and chilly Thursday night, but lows in the mid-upper 20s are
right in line with climo.
Friday through Monday...
Low-confidence forecast here as the models start to diverge. ECMWF
and GFS both drag some combination of a Clipper and/or cold front
across the Ohio Valley Friday night. ECMWF is trending more bullish
with southern-stream phasing and associated moisture. Will not jump
on this solution just yet but it bears watching. For now will go
with a slight chance for snow showers Fri night, mainly east of
I-65.
Cold high pressure plunges south from Canada for the weekend. Below
normal temperatures are a slam dunk but the question remains, how
much below normal? Coldest 850mb temps will be Saturday, when GFS
gets as cold as -14C. Current forecast max temps in the mid 30s may
be a bit too warm. Coldest night is Sat night, with lower 20s
across most locations. Not going for the quick rebound indicated by
extended GFS MOS on Sunday, given the cold start and model bias of
moving a high pressure ridge east too quickly. Expect highs in the
mid/upper 30s even with the thermal trof to our east.
Another southern stream system will affect the Ohio Valley early
next week, but model discrepancies are too large to jump on any one
solution just yet. Will keep Monday dry for now, as the quicker
ECMWF is also the less bullish model as far as QPF. Temps recover to
the high side of normal by Monday.
&&
.Aviation (12Z TAF Issuance)...
Surface high pressure will remain in control at the surface and
aloft through most of today before conditions deteriorate after
midnight as light snow overspreads much of the region. Will have to
deal with some patchy fog early this morning, with BWG having the
most persistent MVFR vis with temporary IFR possible. SDF and LEX
are more likely to stay VFR. Otherwise, expect increasing upper
level sky cover through the day with generally northwest winds
around 5 mph.
After Midnight, light snow is expected to overspread SDF/LEX with
visibilities around the MVFR/VFR threshold and ceilings solidly in
the MVFR range. Further south, BWG should expect mostly rain or a
rain/snow mix with MVFR ceilings.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AL
Short Term.......BJS
Long Term........RAS
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
604 AM EST TUE FEB 07 2012
.Short Term (Today - Wednesday)...
High pressure in place along with weak ridging aloft will keep
things dry today, although will have to deal with patchy
fog/freezing fog potential again through the morning hours. IR
satellite imagery currently shows a batch of low stratus across the
Great Lakes region to as far south as the I 74 corridor over central
and southern Indiana. HRRR has been consistent in showing these
clouds marching steadily southeast through the pre-dawn hours,
arriving near the Ohio River just after dawn. Therefore, skies
should clear in most spots with calm winds and subsident airmass.
This will lead to patchy fog formation, some of which will likely be
dense around dawn. Most likely areas will be in valleys and near
rivers and streams. With temperatures below freezing in most spots
will have to watch for slick spots. Will spend the rest of the
morning monitoring obs and issuing SPS or headline products if need
be. Right now, the only real indication of fog is over the Lake
Cumberland region.
Above mentioned status deck will likely scatter out over southern
Indiana this morning with upper level clouds beginning stream
overhead through the day. With low temperatures cooler than expected
this morning, have lowered highs a bit for this afternoon. Southern
Indiana will likely not make it out of the upper 40s with lower
level cloud cover this morning. Elsewhere, lower 50s can be expected
with mid 50s possible south.
The next weather making system will arrive after Midnight tonight as
an upper level impulse quickly ejects across the plains, absorbing
an upper low currently over NE Colorado. What may initially start
out as rain or a rain/snow mix across southern Indiana and central
Kentucky should quickly change over to snow as wet bulbing occurs
with low level saturation. Surface temperatures may stay just above
freezing in a few locations however warm layer at the surface will
be very shallow and should still support mostly snow. South of a
Bowling Green to Lake Cumberland line, precipitation type is more in
question and could end up being more rain and possibly a rain/snow
mix by dawn.
Best chances for precipitation, whether it be rain or snow, will be
from 3 AM EST to 8 AM EST early Wednesday. Will have to watch for a
moderate band of snow setting up anywhere from along and south of
the Ohio River to along and north of a Bowling Green to Lexington
line between 3 AM EST and dawn. This will occur just ahead of sharp
shortwave trough axis with frontogenesis coinciding with the left
exit region of an intensifying 100 to 120 knot upper level jet.
Models continue to indicate low amounts of QPF with this quick
hitting system, although have steadily increased amounts. Will have
to watch trends over the next 24 hours as banding does appear
possible with this setup and could produce a narrow swath of higher
QPF. That being said, ground and road temperatures should be well
above freezing with recent warm weather so do not expect any real
accumulation on these surfaces. Could see a dusting on grassy and
elevated surfaces by the daylight hours on Wednesday.
Upper level features quickly depart to the east by midday Wednesday,
however plentiful low level moisture between 1000-850 mb suggests
some flurries or sprinkles will be possible. Models are suggesting a
warm up to the low and mid 40s during the day however with overcast
skies expected, have a feeling temperatures will have trouble
getting out of the 30s. Therefore, will call for precipitation type
mostly in light snow or flurry category as any warm layer will be
confined to the surface and low level lapse rates will quickly
steepen. Could even see a few snow bursts through the day on
Wednesday as low levels edge toward a low degree of convective
instability. Again, expecting no real accumulations. Flurries or
sprinkles will linger through the day on Wednesday, along with
mostly cloudy skies.
.Long Term (Wednesday night - Monday)...
Wednesday night through Thursday night...
Main upper impulse will be exiting the area, but still expect some
residual low-level moisture to lingering Wednesday evening.
Subsidence and very shallow moist layer weigh against any precip so
no POPs in the forecast, but moisture and NW flow are sufficient
reason to hold onto a few early evening snow flurries in the eastern
tier.
Cold and dry high pressure on Thursday, with a broad, weak upper
trof overhead. MOS guidance is generally too warm in a shallow cold
air mass like this, so this forecast is more in line with the raw
model temps, with highs in the lower 40s in spite of full sunshine.
Clear and chilly Thursday night, but lows in the mid-upper 20s are
right in line with climo.
Friday through Monday...
Low-confidence forecast here as the models start to diverge. ECMWF
and GFS both drag some combination of a Clipper and/or cold front
across the Ohio Valley Friday night. ECMWF is trending more bullish
with southern-stream phasing and associated moisture. Will not jump
on this solution just yet but it bears watching. For now will go
with a slight chance for snow showers Fri night, mainly east of
I-65.
Cold high pressure plunges south from Canada for the weekend. Below
normal temperatures are a slam dunk but the question remains, how
much below normal? Coldest 850mb temps will be Saturday, when GFS
gets as cold as -14C. Current forecast max temps in the mid 30s may
be a bit too warm. Coldest night is Sat night, with lower 20s
across most locations. Not going for the quick rebound indicated by
extended GFS MOS on Sunday, given the cold start and model bias of
moving a high pressure ridge east too quickly. Expect highs in the
mid/upper 30s even with the thermal trof to our east.
Another southern stream system will affect the Ohio Valley early
next week, but model discrepancies are too large to jump on any one
solution just yet. Will keep Monday dry for now, as the quicker
ECMWF is also the less bullish model as far as QPF. Temps recover to
the high side of normal by Monday.
&&
.Aviation (12Z TAF Issuance)...
Surface high pressure will remain in control at the surface and
aloft through most of today before conditions deteriorate after
midnight as light snow overspreads much of the region. Will have to
deal with some patchy fog early this morning, with BWG having the
most persistent MVFR vis with temporary IFR possible. SDF and LEX
are more likely to stay VFR. Otherwise, expect increasing upper
level sky cover through the day with generally northwest winds
around 5 mph.
After Midnight, light snow is expected to overspread SDF/LEX with
visibilities around the MVFR/VFR threshold and ceilings solidly in
the MVFR range. Further south, BWG should expect mostly rain or a
rain/snow mix with MVFR ceilings.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Short Term.......BJS
Long Term........RAS
Aviation.........BJS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
956 AM EST TUE FEB 7 2012
.SYNOPSIS...
A SHALLOW COLD FRONT WILL SPREAD LOW CLOUDS ACROSS THE UPPER OHIO
VALLEY AND SOUTH OF THE MASON DIXON LINE THIS AFTERNOON. LOW PRESSURE WILL
MOVE EASTWARD ALONG THE STALLED FRONT WEDNESDAY, AND BRING SNOW
SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID MORNING UPDATE TO BRING STRATUS DECK SOUTH AS AFTERNOON
PROGRESSES WITH CURRENT SPREAD OF DECK TO REACH SOUTHERN TIER OF
COUNTIES DURING TE AFTERNOON. CURRENT FORECAST MAX TEMPS LOOK IN
LINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
SHORTWAVE IN THE SOUTHERN STREAM OF CONFLUENT FLOW PROJECTED OVER
THE REGION IS PROGGED TO GENERATE SNOW SHOWERS ALONG THE SOUTHWARD
SAGGING, AFOREMENTIONED COLD FRONT LATE TUESDAY NIGHT/WEDNESDAY.
CHANCE PRECIP PROBABILITIES WERE INCLUDED FOR THIS SCENARIO, BUT
WITH BETTER NUMBERS OVER SOUTHERN ZONES DUE TO EXPECTED PROGRESS
OF THE FRONT. LIKELY NUMBERS THAT WERE FORECAST FOR THE RIDGES ARE
DUE TO EXTRA SUPPORT VIA DEVELOPING UPSLOPE.
OVERALL, LIGHT SNOW ACCUMULATION IS POSSIBLE ON WEDNESDAY WITH
AMOUNTS LIMITED BY THE PROGRESSIVE NATURE OF THE SYSTEM AND
SURFACE TEMPERATURES ABOVE FREEZING.
TEMPERATURES WERE FORECAST NEAR NORMAL USING A BLEND OF GUIDANCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LATEST ECMWF AND GFS MODEL OUTPUT SHOWS A DEEP UPPER TROUGH SWINGING
THROUGH EASTERN CANADA BY THE WEEKEND. TIMING OF THE ASSOCIATED
COLD FRONT STILL VARIES SOMEWHAT BETWEEN GFS/ECMWF, BUT LATEST
THINKING IS THAT THE FRONT WILL PUSH ACROSS THE FORECAST AREA LATE
FRIDAY, BRINGING SCATTERED SNOW SHOWERS, POSSIBLY MIXING WITH RAIN
SHOWERS IN THE SOUTH, AND A RETURN TO MORE WINTER-LIKE TEMPERATURES.
SURFACE HIGH PRESSURE AND DRIER AIR ARE PROJECTED TO MOVE OVER
THE OHIO VALLEY ON SUNDAY AND MONDAY.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
PER BLEND OF RECENT SURFACE AND SATELLITE DATA, NAM AND HRRR MODEL
OUTPUT, AND GFS LAMP, EXPECT SHALLOW COLD FRONTAL BAND OF
STRATOCUMULUS, SPREADING SOUTHWARD AT 15 KTS, TO GET AS FAR SOUTH
AS THE MASON-DIXON LINE BY 16Z, BEFORE STOPPING. CEILINGS WILL BE
MAINLY AT MVFR LEVELS, BUT BRIEF IFR INTERLUDES CANNOT BE RULED
OUT THIS MORNING. HAVE LOW CONFIDENCE THAT THE CLOUDS REACH KMGW.
TERMINALS SUCH AS KZZV, KHLG, AND KLBE MAY SEE CLOUD COVERAGE GO
SCATTERED FOR A TIME THIS AFTERNOON.
IN GENERAL, EXPECT MVFR CEILINGS TONIGHT, EVEN AT KMGW LATE
TONIGHT, AS LOW PRESSURE APPROACHES FROM THE WEST.
SURFACE WINDS WILL GO TO NORTH-NORTHWEST NEAR 10 KTS BY MIDDAY.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
AN EASTBOUND LOW PRESSURE SYSTEM WILL DEEPEN THE COLD FRONT TO YIELD
MVFR SNOW SHOWERS BY DAYTIME WEDNESDAY. ENSUING HIGH PRESSURE WILL
PROVIDE VFR THURSDAY AND FRIDAY. A COLD FRONTAL BAND OF SNOW
SHOWERS WILL PROVIDE RESTRICTIONS SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
642 AM EST TUE FEB 7 2012
.SYNOPSIS...
A SHALLOW COLD FRONT WILL SPREAD LOW CLOUDS ACROSS THE UPPER OHIO
VALLEY AS FAR SOUTH AS THE MASON DIXON LINE. LOW PRESSURE WILL
MOVE EASTWARD ALONG THE STALLED FRONT WEDNESDAY, AND BRING SNOW
SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE TWEAKED SOUTHWARD SPREAD OF LOW CLOUDS ACROSS THE UPPER OHIO
VALLEY BASED ON RECENT SATELLITE DATA AND HRRR MODEL OUTPUT. THE
CLOUDS ARE ASSOCIATED WITH A SHALLOW COLD FRONT, THAT IS EXPECTED
TO STALL NEAR THE MASON-DIXON LINE.
THE CLOUDS WILL HAVE A BIG EFFECT ON SUNSHINE AND TEMPERATURES
TODAY, WITH CLOUDY AREAS A FEW DEGREES COLDER THAN SUNNY NORTHERN
WEST VIRGINIA. HAVE FORECASTED TEMPERATURE DETAILS USING BLEND OF
SREF AND HRRR MODEL OUTPUT AND GFS MOS AND LAMP.
THERE IS THE POSSIBILITY THAT AREAS STRADDLING THE I-70 CORRIDOR
CAN GET A LITTLE SUN THIS AFTERNOON, AS HRRR AND NAM MODEL OUTPUT
SUGGEST THERE MAY BE SOME EROSION OF THE THIN CLOUDS NEAR THE
CLOUD BANKS SOUTHERN EDGE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
SHORTWAVE IN THE SOUTHERN STREAM OF CONFLUENT FLOW PROJECTED OVER
THE REGION IS PROGGED TO GENERATE SNOW SHOWERS ALONG THE SOUTHWARD
SAGGING, AFOREMENTIONED COLD FRONT LATE TUESDAY NIGHT/WEDNESDAY.
CHANCE PRECIP PROBABILITIES WERE INCLUDED FOR THIS SCENARIO, BUT
WITH BETTER NUMBERS OVER SOUTHERN ZONES DUE TO EXPECTED PROGRESS
OF THE FRONT. LIKELY NUMBERS THAT WERE FORECAST FOR THE RIDGES ARE
DUE TO EXTRA SUPPORT VIA DEVELOPING UPSLOPE.
OVERALL, LIGHT SNOW ACCUMULATION IS POSSIBLE ON WEDNESDAY WITH
AMOUNTS LIMITED BY THE PROGRESSIVE NATURE OF THE SYSTEM AND
SURFACE TEMPERATURES ABOVE FREEZING.
TEMPERATURES WERE FORECAST NEAR NORMAL USING A BLEND OF GUIDANCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LATEST ECMWF AND GFS MODEL OUTPUT SHOWS A DEEP UPPER TROUGH SWINGING
THROUGH EASTERN CANADA BY THE WEEKEND. TIMING OF THE ASSOCIATED
COLD FRONT STILL VARIES SOMEWHAT BETWEEN GFS/ECMWF, BUT LATEST
THINKING IS THAT THE FRONT WILL PUSH ACROSS THE FORECAST AREA LATE
FRIDAY, BRINGING SCATTERED SNOW SHOWERS, POSSIBLY MIXING WITH RAIN
SHOWERS IN THE SOUTH, AND A RETURN TO MORE WINTER-LIKE TEMPERATURES.
SURFACE HIGH PRESSURE AND DRIER AIR ARE PROJECTED TO MOVE OVER
THE OHIO VALLEY ON SUNDAY AND MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
PER BLEND OF RECENT SURFACE AND SATELLITE DATA, NAM AND HRRR MODEL
OUTPUT, AND GFS LAMP, EXPECT SHALLOW COLD FRONTAL BAND OF
STRATOCUMULUS, SPREADING SOUTHWARD AT 15 KTS, TO GET AS FAR SOUTH
AS THE MASON-DIXON LINE BY 16Z, BEFORE STOPPING. CEILINGS WILL BE
MAINLY AT MVFR LEVELS, BUT BRIEF IFR INTERLUDES CANNOT BE RULED
OUT THIS MORNING. HAVE LOW CONFIDENCE THAT THE CLOUDS REACH KMGW.
TERMINALS SUCH AS KZZV, KHLG, AND KLBE MAY SEE CLOUD COVERAGE GO
SCATTERED FOR A TIME THIS AFTERNOON.
IN GENERAL, EXPECT MVFR CEILINGS TONIGHT, EVEN AT KMGW LATE
TONIGHT, AS LOW PRESSURE APPROACHES FROM THE WEST.
SURFACE WINDS WILL GO TO NORTH-NORTHWEST NEAR 10 KTS BY MIDDAY.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
AN EASTBOUND LOW PRESSURE SYSTEM WILL DEEPEN THE COLD FRONT TO YIELD
MVFR SNOW SHOWERS BY DAYTIME WEDNESDAY. ENSUING HIGH PRESSURE WILL
PROVIDE VFR THURSDAY AND FRIDAY. A COLD FRONTAL BAND OF SNOW
SHOWERS WILL PROVIDE RESTRICTIONS SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
625 AM EST TUE FEB 7 2012
.SYNOPSIS...
ISSUED AT 427 AM EST TUE FEB 7 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW RATHER SHEARED
POSITIVELY TILTED SHRTWV DROPPING SEWD THRU THE UPR LKS IN
PREVAILING NW FLOW ALF BTWN TROF OVER QUEBEC AND UPR RDG OVER WRN
CAN. ACCOMPANYING SHARP COLD FNT THAT SURGED THRU THE FA YDAY HAS
NOW PUSHED TO THE S. ALTHOUGH MUCH COLDER AIR IS FOLLOWING THE FNT
WITH NNE FLOW AND 00Z H85 TEMPS RANGING FM 0C AT GRB TO -10C AT INL
AND -17C AT YPL...SGNFT LES HAS NOT DEVELOPED EVEN IN AREAS FAVORED
BY THE NNE FLOW. KEY FACTORS APPEAR TO BE IMPRESSIVE DRYING
REFLECTED BY 00Z YPL RAOB /00Z PWAT 0.06 INCH/ THAT IS STEADILY
ERODING THE BACK EDGE OF THE LK CLD AS SHOWN ON IR STLT IMAGERY...
SUBSIDENCE ASSOCIATED WITH FAIRLY VIGOROUS DNVA/CAD/DEEP LYR QVECTOR
DVGC IN THE WAKE OF THE SHRTWV THAT IS CAUSING THE LLVL FLOW TO
BECOME ACYC AND SINK INVRN BASE TO ARND H9 AS SHOWN ON THE 00Z INL
AND YPL RAOBS. UNDER SFC RDG AXIS IN ONTARIO EXTENDING E FM HI
CENTER NEAR LK WINNIPEG...SKIES ARE MOCLR...AND SFC TEMPS/DWPTS HAVE
FALLEN INTO THE ZERO TO -10F RANGE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EST TUE FEB 7 2012
TODAY...COLD NLY FLOW IS FCST TO PERSIST THRU THIS MRNG BEFORE HI
PRES CENTER BLDG FM LK WINNIPEG INTO MN CAUSES THE LLVL FLOW TO BACK
TO THE W BY LATE IN THE DAY. THE COLDEST MODELS...NOTABLY THE 00Z
CNDN AND LOW WRF-ARW...SHOW H85 TEMPS SINKING TO -15 TO -17C OVER
SCNTRL LK SUP THIS MRNG WHILE THE WARMER 00Z NAM/GFS INDICATE THESE
TEMPS WL FALL NO LOWER THAN -14C OR SO. THE DIFFERENCE APPEARS TO BE
RELATED TO THE INVRN HGT FCST...WITH THE WARMER MODELS INDICATING A
LOWER INVRN BASE AOB 3K FT /NAM/ AS COMPARED TO ARND 4K FT
/WRF-ARW/. SINCE DEEP LYR QVECTOR DVGC/SUBSIDENCE WL INTENSIFY THRU
THE DAY AND TRENDS ON OBSVD SKY COVER OVER LK SUP SUG THE INVRN IS
CRASHING...WL TEND TO FOLLOW THE WARMER/LO INVRN BASE DEPICTED BY
THE 00Z NAM. THIS MODEL SHOWS ALMOST NO PCPN EVEN IN THE N WIND SN
BELTS WITH DIFFLUENT FLOW/H925-85 DEWPT DEPRESSION AS HI AS 7-10C
EVEN OVER THE N WIND SN BELTS THAT WOULD OTRW BE FAVORED BY THE LLVL
FLOW. SO ALTHOUGH SOME LES IS LIKELY TO BREAK OUT IN THE NEXT FEW
HRS THRU 12Z WITH THE ARRIVAL OF COLDER AIR...ANY SN ACCUM SHOULD BE
NO MORE THAN ARND AN INCH EVEN OVER THE HIER TERRAIN. BACKING MORE
ACYC FLOW THIS AFTN WITH INVRN BASE REMAINING BLO 3K FT SHOULD
DIMINISH THE LES FURTHER. ALTHOUGH DAYTIME TEMPS WL BE JUST A BIT
BELOW NORMAL...RECENT WARMTH WL MAKE THE DAY FEEL EVEN COLDER...
ESPECIALLY THIS MRNG WITH A STEADY N WIND.
TNGT...SFC HI PRES RDG AXIS IS FCST TO BE NEARLY OVHD IN THE EVNG
BUT THEN SHIFT TO THE S. WITH CONTINUED SUBSIDENCE AND THE FLOW
BACKING TO THE W...EXPECT SKIES TO TURN MOCLR EXCEPT PERHAPS OVER
THE KEWEENAW AND NEAR LK SUP E OF MUNISING. PWAT IS FCST TO BE 0.10
INCH AT 00Z...SO EXPECT A QUICK FALL OF TEMP IN THE EVNG WITH LGT
WINDS...SO ACCELERATED EARLY FALL OF TEMP. ONCE THE RDG SHIFTS TO
THE S OVERNGT...A STRONGER WNW WIND WL DVLP...WITH H925 WINDS FCST
UP TO 30-35 KTS. RETAINED GOING FCST MIN TEMPS AOB THE LO END OF
GUIDANCE PER VERY DRY AIR/OBSVD CHILL UPSTREAM OVER THE MORE
SHELTERED SRN TIER. TEMPS WL BE QUITE A BIT WARMER NEAR THE MORE
EXPOSED LK SUP AND UNDER THE SHARPER PRES GRADIENT FARTHER N OF THE
RDG AXIS...ESPECIALLY OVER THE E WHERE SOME LO CLDS MAY LINGER NEAR
THE SHORE THRU THE NGT UNDER WNW H925 FLOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 427 AM EST TUE FEB 7 2012
TROUGH WILL BE EXITING INTO EASTERN CANADA TO START THE LONG TERM
WHICH ALLOWS FOR HEIGHTS TO RISE FM PLAINS INTO GREAT LAKES. AT THE
SFC...HIGH PRESSURE OVER THE PLAINS SLIDES SOUTH ON WEDNESDAY
ALLOWING FOR WESTERLY WINDS AT LOW-LEVELS OVR UPR LAKES INTO
WEDNESDAY NIGHT. WEST WINDS ALONG WITH JUST SCT MID CLOUDS RESULTED
IN RAISING MAX TEMPS TOWARD HIGHER END OF GUIDANCE /AROUND 30 INLAND
AND INTO THE MID 30S NEAR LK SUPERIOR/. NEXT COLD FRONT WILL BE
DROPPING SOUTH ACROSS ONTARIO ON WEDNESDAY NIGHT...SO EXPECT AT
LEAST LGT WEST WINDS TO PERSIST THROUGH THE NIGHT. INLAND AREAS
COULD TRY TO DECOUPLE AND FALL INTO THE TEENS...BUT TEMPS ALONG
SHORELINES OF LK SUPERIOR AND LK MICHIGAN SHOULD STAY IN THE MID TO
UPR 20S. FCST SOUNDINGS FM BOTH NAM AND GFS INDICATE CONDITIONS TOO
DRY TO SUPPORT ANY PCPN AHEAD OF THE FRONT IN THE WESTERLY FLOW.
HAVE REMOVED ANY MENTION OF SNOW UNTIL THURSDAY...EVEN OVR THE
KEWEENAW PENINSULA.
CHANGES BEGIN TO OCCUR LATER THURSDAY AS ARCTIC COLD FRONT IS FCST
TO ARRIVE. PROBABLY WILL SEE FALLING TEMPS...BUT AT THIS POINT STUCK
WITH NORMAL DIURNAL TEMP CURVE AS PRIMARY COOLING FM FROPA DOES NOT
OCCUR UNTIL LATE IN THE DAY. SOUNDINGS SHOW SUFFICIENT MOISTENING TO
JUSTIFY SOME SNOW SHOWERS BY LATE AFTN OVR KEWEENAW. ELSEWHERE...
CHANCES OF PCPN ON THURSDAY LOOK MINIMAL. LK EFFECT THEN BECOMES
MORE OF AN ISSUE BY THURSDAY EVENING AS NW WINDS IN BLYR VEER MORE
NORTHERLY. H85 TEMPS FALLING BLO -20C PER GFS/ECMWF LEAD TO SURGE OF
OVER-WATER INSTABILITY WITH LAKE EFFECT EQL AOA 8KFT AND SFC-H85
LAPSE RATES OVR 9C/KM. INSTABILITY IS SUPPLEMENTED BY MID LEVEL
MOISTURE /UP TO H7/. OVERALL SETUP APPEARS FAVORABLE FOR MODERATE
AND POSSIBLY HEAVY LK EFFECT SNOW SHOWERS THURSDAY NIGHT INTO
FRIDAY. SNOW WILL BE FLUFFY AS MAJORITY OF LAKE EFFECT CONVECTIVE
LAYER IS WITHIN THE DENDRITIC GROWTH ZONE. SLR/S FM COBB METHOD IN
BUFKIT RISE WELL ABOVE 20:1.
ONLY MAIN ISSUE TO SORT OUT STILL IS EXACT BLYR WIND DIRECTION. NAM
IS STRONGEST WITH SFC TROUGH AND ASSOCIATED NORTHEAST WINDS DEVELOPING
IN THE WAKE OF THE TROUGH. GFS/ECMWF ARE MORE NORTHERLY WITH THE
WINDS WHILE CANADIAN SHOWS WINDS REMAINING FM NORTHWEST. DO LIKE THE
NAM IDEA INDICATING SHARP WIND SHIFT JUST IN WAKE OF ARCTIC
FRONT...BUT WENT WITH BLEND OF NAM AND PREVIOUS FCST FOR THE WINDS.
RESULT OF THIS CHOICE WAS SOLN WITH WINDS THAT LOOKED LIKE LATEST
ECMWF. GIVEN FAVORABLE OVER-WATER INSTABILITY AND EXPECTED NORTHERLY
WINDS...INCREASED POPS TO LIKELY OVR NORTH WIND SNOW BELTS IN FAR
WEST AND NORTH CENTRAL UPR MI. SEVERAL INCHES OF SNOW SEEMS POSSIBLE
THURSDAY NIGHT INTO FRIDAY...AND WILL CONTINUE TO MENTION THIS IN
THE HAZARDOUS WEATHER OUTLOOK.
IN THE EXTENDED...AGREEMENT IN OVERALL IDEA THAT FIRST PORTION OF
THE WEEKEND WILL BE DOMINANTED BY LINGERING COLD AIRMASS /H85 TEMPS
AROUND -20C/ THAT MOVES IN LATE THIS WEEK. LK EFFECT IN NORTH TO
NORTHWEST FLOW AREAS FRIDAY AND FRIDAY NIGHT WILL DIMINISH ON
SATURDAY AS WINDS TURN MORE WESTERLY AHEAD OF YET ANOTHER COLD
FRONT. BOTH GFS/ECMWF POINT TO CENTER OF POLAR VORTEX WITH H85 TEMPS
NEAR -30C TO FINALLY COME SOUTH INTO GREAT LAKES BY SUNDAY. VORTEX
IS QUITE COMPACT THOUGH AND IT SEEMS DIFFICULT AT BEST TO FCST WHERE
THE CORE OF COLDEST AIR WILL ACTUALLY TRAVEL. GFS IS FARTHER WEST
AND WOULD RESULT IN MIN TEMPS ON SATURDAY NIGHT WELL BLO ZERO IN THE
CNTRL AND EAST. ECMWF IS FARTHER EAST WITH THE VORTEX. SEEMS LIKE
TREND THIS WINTER OF ONLY GLANCING BLOWS OF COLDER AIR OVR UPR LAKES
WOULD SUPPORT THE ECMWF IDEA.
LK EFFECT MAY KICK UP AGAIN LATE IN THE WEEKEND...THOUGH LOW
INVERSION HEIGHTS AND VERY DRY LOW-LEVELS WILL KEEP ACCUMS IN CHECK.
BLEND OF MODELS WORKS FOR NOW...WHICH RESULTED IN SLIGHT CHANCES FOR
SNOW SHOWERS. DUE TO FINE NATURE OF CRYSTALS/NEEDLES IN SUCH A COLD
AIRMASS...THE MAIN IMPACT FM THE SNOW SHOWERS WOULD BE REDUCED
VSBY...ESPECIALLY WITH SOME WIND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 624 AM EST TUE FEB 7 2012
EXPECT MVFR CIGS TO GIVE WAY TO CLRG/VFR CONDITIONS THIS AFTN WITH
THE ARRIVAL OF A HI PRES RIDGE/VERY DRY LLVL AIR. AS THE HI PRES RDG
SINKS TO THE S TNGT...EXPECT A GUSTY W WIND AT CMX UNDER SHARPER
PRES GRADIENT ON THE MORE EXPOSED KEWEENAW PENINSULA. WINDS WL
REMAIN LGT AT THE SHELTERED IWD/SAW LOCATIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EST TUE FEB 7 2012
SINCE THE N WINDS EARLY THIS MORNING ARE NOT AS STRONG AS EARLIER
ANTICIPATED...GENERALLY NO HIER THAN 25 KT...CANX THE PREVIOUS HEAVY
FREEZING SPRAY WARNING THAT WAS IN EFFECT UNTIL 15Z FOR PORTIONS OF
CENTRAL LK SUP. WINDS TODAY WILL DIMINISH FURTHER WITH THE ARRIVAL
OF A HI PRES RDG/WEAKER PRES GRADIENT. ONCE THE HI CENTER DRIFTS
FARTHER S TONIGHT...A STRONGER W WIND UP TO 30 KTS WILL DEVELOP LATE
UNDER THE SHARPENING PRES GRADIENT BETWEEN THE RETREATING HI AND
FALLING PRES ACROSS ONTARIO. GRADIENT TIGHTENS FURTHER ON WEDNESDAY
WHICH COULD RESULT IN A FEW WESTERLY GALE GUSTS. WINDS BRIEFLY
DIMINISH LATER WEDNESDAY NIGHT INTO THURSDAY MORNING...BUT THEN
VEER NORTH AND INCREASE TO 30 KTS LATE THURSDAY AFTERNOON INTO
THURSDAY NIGHT. HEAVY FREEZING SPRAY IS POSSIBLE THURSDAY NIGHT OVER
MUCH OF THE LAKE. EXPECT NORTH WINDS TO DIMINISH BLO 25 KTS LATER
FRIDAY WITH WINDS STAYING BLO 25 KTS THROUGH THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS GLASGOW MT
358 AM MST TUE FEB 7 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
1040 MB SURFACE HIGH CENTERED OVER CENTRAL SK THE MAIN INFLUENCE
ON OUR WEATHER AS IT MOVES SLOWLY SSE. TEMPS NOT PARTICULARLY
COLD WITH THIS.
NE FLOW AND RESULTING UPSLOPE INFLUENCED STRATUS COVERS ALL OF NE
MT...W ND...AND MOST OF S SK. THIS HAS PROVED A MAJOR FORECAST
BUGABOO. MOST MODELS HAVE BEEN OF LITTLE HELP AND WAY TOO FAST IN
CLEARING THE STRATUS OUT. SATELLITE FOG LOOP SHOWS THE STRATUS NOT
MOVING OR CHANGING MUCH. AT THIS RATE...WILL HAVE TO KEEP SKIES CLOUDY
THROUGH MOST OF THE DAY. DO EXPECT SOME CLEARING TO START SHOWING
IN TOUR N THIS AFTERNOON. AS THE SURFACE HIGH MOVES NEAREST TO US
AND THEN SE...IT SHOULD CLEAR ALL STRATUS OUT THIS EVENING. WILL CONFINE
FLURRY MENTION TO OUR EXTREME SW WHERE THERE ARE LAYERED HIGHER
CLOUD STILL ABOVE THE STRATUS.
OVERCAST HELD LOWS UP 10F OR MORE THAN EXPECTED LAST NIGHT.
HOWEVER WITH THE STRATUS STICKING AROUND MOST OF THE DAY...AND
COLDER PART OF THE AIRMASS NOW OVER US...HIGHS WON`T BE VERY MUCH
WARMER THAN THIS MORNINGS LOWS. COLDER TONIGHT THOUGH WITH
CLEARING SKIES FINALLY.
REX BLOCK UPPER PATTERN HAS BEEN BREAKING DOWN. UPPER RIDGE WILL
SHIFT AROUND A LITTLE...BUILDING STRONGLY N OVER THE PACIFIC COAST
STATES AND BC. THIS WILL INCREASE THE NNW FLOW ALOFT OVER OUR AREA
BETWEEN HE RIDGE AND THE HUDSON BAY LOW.
THE CANADIAN HIGH PRESSURE MOVES SE OUT OF THE AREA WED...ALLOWING
FOR SOME WARMING UNDER SUNNY SKIES. MODELS HAVE BEEN TRENDING
SLOWER WITH THE NEXT COLD FRONT THAT ARRIVES IN THE NNW FLOW...NOW
MOVING THRU THE CWA THURSDAY. 850 MB WINDS INCREASE TO AS HIGH AS
40KT 12-15Z. MODEL FORECAST SOUNDINGS ARE JUST SHORT OF DRY
ADIABATIC MIXED TO AROUND 900 MB AT THAT TIME AS MODERATE COLD
ADVECTION STARTS IN OUR N. SO TIMING NOT QUITE IDEAL TO MIX
MAXIMUM WINDS TO SURFACE...BUT IT WILL BE WINDY. AS WE MIX DRY
ADIABATICALLY TO ABOVE 900 MB IN THE AFTERNOON...WINDS AT THAT
LEVEL ARE LESS THEN. ANOTHER DRY COLD FRONT. MODELS INDICATE THERE
WILL BE JUST A SHORTLIVED NARROW BAND OF STRATUS BEHIND THE FRONT. SIMONSEN
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
THE EXTENDED BEGINS WITH HIGH PRESSURE OVER MANITOBA AND A
STATIONARY FRONT UP AGAINST THE ROCKY MOUNTAIN FRONT RANGE. MODELS
IN FAIR AGREEMENT WITH THIS SOLUTION FOR THE START OF THE PERIOD
FRIDAY MORNING.
FRIDAY THROUGH THE WEEKEND THE UPPER LOW OVER HUDSON BAY MOVES
INTO QUEBEC DRAGGING THE HIGH PRESSURE SYSTEM OVER MANITOBA SOUTH
AND EAST TOWARDS THE GREAT LAKES. THE NEXT EFFECT WILL BE A
WARMING TREND FOR NORTHEAST MONTANA. THE STATIONARY FRONT WILL
BECOME MORE OF A LEE TROUGH AND COULD PROVIDE A FOCUS OVER THE FAR
WESTERN ZONES FOR SOME VERY LIGHT PRECIPITATION. WILL KEEP THE
MENTION OF PRECIPITATION OUT FOR THE ZONES AT THIS TIME.
EARLY NEXT WEEK...THE EC AND GFS BRING AN UPPER LEVEL LOW THROUGH
NORTHEAST MONTANA AT DIFFERENT TIME STEPS... FOR NOW WILL JUST
KEEP SLIGHT CHANCE POPS IN THE FORECAST UNTIL THE MODELS COME
TOGETHER WITH FUTURE RUNS. PROTON
&&
.AVIATION...
MVFR STRATUS IS HOLDING OVER THE REGION. DO EXPECT THE MVFR
CEILINGS TO CONTINUE OVER THE REGION THROUGH 18Z. THE CEILINGS
SHOULD SLOWLY BREAK UP AFTER THAT. FOLLOWING THE HRRR AND SREF
GUIDANCE THIS MORNING SINCE THE MOS PRODUCTS HAVE HANDLED THIS
EVENT POORLY. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BILLINGS MT
336 AM MST TUE FEB 7 2012
.SHORT TERM...VALID FOR TDY AND WED...
MOISTURE CHANNEL IMAGERY AT 10 UTC REVEALS SIGNIFICANT DRYING OVER
NORTHERN MT...WITH SOME OF THE MOST ROBUST DARKENING ACTUALLY NEAR
GREAT FALLS. RUC OBJECTIVE ANALYSES SUGGEST THAT A SIGNIFICANT 1.5
PVU LOWERING DOWN TO NEAR 500 HPA IS ASSOCIATED WITH THIS FEATURE.
THIS FORCING IS MUCH SLOWER AND FURTHER WEST THAN WHAT MODELS HAVE
BEEN SUGGESTING...PERHAPS THANKS TO THE DOWNSTREAM PATTERN THAT IS
LARGELY INFLUENCED BY THE REMNANT REX BLOCK OF LAST WEEKEND. THERE
IS THUS INCREASING CONCERN THAT AT LEAST SOME LIGHT SNOW SHOULD BE
MORE PREVALENT OVER SOUTH CENTRAL MT TODAY THAN EARLIER THOUGHT AS
THIS FEATURE WORKS IN CONCERT WITH UPSLOPE FLOW AND MODEST AMOUNTS
OF LOW- TO MID-LEVEL FRONTOGENESIS.
AS FAR AS THE DETAILS GO...THE SHALLOW UPSLOPE FLOW WHICH HAS BEEN
OCCURRING BENEATH THE DENDRITIC LAYER HAS BEEN RESPONSIBLE FOR 0.5
TO 1.0 INCH SNOW AMOUNTS SINCE MONDAY. RADAR IMAGERY SUGGESTED THE
SNOW TAPERED OFF TO FLURRIES BY 06 UTC...BUT MORE RECENTLY WE NOTE
SOME ADDITIONAL ENHANCEMENT SOUTH OF BILLINGS NEAR WHERE WE EXPECT
SOME FRONTOGENESIS OR WEAK WARM AIR ADVECTION TO BEGIN. THIS RADAR
TREND CONFIRMS THE IDEA HELD BY THE 03 AND 06 UTC RUC RUNS OF SOME
RENEWED SNOW FROM BIG TIMBER TO BILLINGS AND HARLOWTON TODAY. SNOW
IS SUPPORTED BY LIGHT UPSLOPE FLOW IN AND OF ITSELF...BUT IT LOOKS
LIKE THESE RUC RUNS ARE KEYING IN ON ENOUGH QPF FOR SOME 1-3 INCH
SNOW AMOUNTS THROUGH SIMULATION OF DEEPER FORCING WITH THE WAVE IN
CENTRAL MT AMIDST A MODEST LOW- AND MID-LEVEL FRONTOGENESIS ZONE.
THE 00 UTC NAM AND GFS ALSO SUGGEST NOTABLE VERTICAL MOTION ON 285
AND 290 K ISENTROPIC SURFACES IN THESE SAME AREAS TODAY...AND THEY
EVEN SHOW POSITIVE PRESSURE ADVECTION OF 1 TO 2 HPA. THE LATEST 06
UTC NAM RESPONDS TO THIS BY SHOWING QPF FROM BILLINGS WEST OVER TO
BIG TIMBER AND NORTH TO HARLOWTON AND ROUNDUP TODAY. ADDING TO THE
BELIEF THAT THERE WILL BE SOME LIGHT SNOW IN THESE AREAS TODAY ARE
THE 00 UTC GEFS MEMBERS...OF WHICH SEVERAL SHOW PRECIPITATION EVEN
AFTER 18 UTC TODAY. AS A RESULT...WE HAVE INCLUDED LIKELY AND EVEN
CATEGORICAL POPS TODAY FOR PARTS OF SOUTH CENTRAL MT. NOTE THAT WE
FEEL THE FOOTHILLS REQUIRE NO MORE THAN CHANCE POPS TODAY GIVEN AN
EXPECTATION FOR THE LOW- AND MID-LEVEL FRONT TO PULL NORTHEAST OFF
OF THEM DURING THE MORNING. RADAR TRENDS AT 10 UTC CONFIRM THIS.
THOUGH LIQUID PRECIPITATION AMOUNTS WILL BE LIGHT...SNOW RATIOS ON
THE ORDER OF 15 OR 20 TO 1 WILL YIELD ANOTHER 0.5 TO 1 INCH ACROSS
PARTS OF SOUTH CENTRAL MT. ADMITTEDLY...PLACES THAT END UP BENEATH
A PERSISTENT LIGHT SNOW BAND COULD PICK UP CLOSER TO 2 OR 3 INCHES
LIKE THE 03 UTC RUC SHOWED...BUT WHICH IT HAS SINCE BACKED OFF ON.
WHILE WE DO NOT FEEL AN ADVISORY WILL BE NECESSARY...IT IS NOT OUT
OF THE QUESTION THAT A SHORT-FUSE ONE COULD STILL BE REQUIRED ONCE
TRENDS BECOME ESTABLISHED WITH MORE CONFIDENCE THIS MORNING.
STRATUS REMAINS ENTRENCHED ALONG AND WEST OF THE SURFACE HIGH AXIS
ALL THE WAY NORTH INTO CENTRAL SASKATCHEWAN AS OF 10 UTC...SO WITH
PERSISTENT UPSLOPE EXPECTED TODAY...WE DECIDED TO KEEP SUBSTANTIAL
AMOUNTS OF CLOUDS IN THE FORECAST AREA-WIDE. OF COURSE...THE MODEL
GUIDANCE WOULD HAVE US BELIEVE OTHERWISE...BUT CASES LIKE THIS ONE
OFTEN BENEFIT FROM A PERSISTENCE FORECAST. WE ARE PORTRAYING HIGHS
IN THE 20S F TODAY...WHICH IS COLDER THAN EARLIER FORECASTS DUE TO
THE ADDITIONAL STRATUS AND WEAK BOUNDARY LAYER FLOW.
WARM AIR ADVECTION WILL GET GOING ON WED...BUT HOW QUICKLY THAT IS
GOING TO TRANSLATE TO SURFACE WARMING IS SOMEWHAT UNCERTAIN WITH A
LINGERING NORTHERLY FLOW ALOFT. WE THUS LET CONTINUITY RULE DURING
THIS PART OF THE FORECAST FOR NOW. SCHULTZ
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
WEST COAST RIDGE AMPLIFICATION CONTINUES IN THE LATEST MODEL RUNS
FOR THURSDAY INTO FRIDAY. THIS ALLOWS COLD AIR OVER NORTHERN
CANADA TO DROP SOUTHWARD INTO THE NORTHERN PLAINS. MODELS HAVE
BEEN STRUGGLING WITH HOW FAR WEST TO ALLOW THIS COLD AIR TO
PENETRATE...AND LATEST RUNS CONTINUE THIS TREND. CURRENT THINKING
IS THAT LOW PRESSURE TO THE WEST OF THE AREA UNDER DEVELOPING
RIDGE SHOULD BE ENOUGH TO ALLOW COLD AIR TO BACK UP INTO THE
FOOTHILLS FOR LATE THURSDAY AND INTO FRIDAY. KEPT FORECAST ON THE
COLD SIDE OF GUIDANCE FOR THIS TIME FRAME. LATEST MODEL RUNS ALSO
KEEP PERSISTENT CYCLONIC FLOW OVER THE NORTHERN PLAINS PREVENTING
COLD AIR FROM FULLY RETREATING DURING THE WEEKEND FROM EASTERN
ZONES THIS SETS UP A POTENTIAL BAROCLINIC ZONE THAT WOULD PRODUCE
ISOLATED TO SCATTERED SNOW SHOWERS FROM TIME TO TIME. AS A RESULT
INCREASED POPS FOR THE COLD AIR BUILDING IN THURSDAY AND FRIDAY
AND FOR THE BAROCLINIC ZONE GOING INTO THE WEEKEND. MOISTURE IS
LIMITED DURING THIS TIME FRAME SO ANY SNOW ACCUMULATIONS SHOULD BE
LIGHT. A PATTERN CHANGE CONTINUES TO BE ADVERTISED BEGINNING THE
END OF THE WEEKEND THAT WOULD OPEN THE AREA UP TO SYSTEMS COMING
OFF THE NORTH PACIFIC. THIS WOULD BRING SEASONAL TEMPERATURES AND
MORE MOISTURE TO THE AREA MONDAY INTO THE MIDDLE OF NEXT WEEK.
CURRENTLY HAVE CLIMO TYPE TEMPERATURES AND POPS IN THE FORECAST
FOR THIS TIME FRAME. CHAMBERS
&&
.AVIATION...
MVFR TO OCCASIONAL IFR CONDITIONS WILL CONTINUE THROUGH THE
MORNING HOURS AT ALL TAF LOCATIONS. AREAS OF LIFR CONDITIONS ARE
POSSIBLE NEAR EXPECTED HEAVIER SNOW BANDS ACROSS CENTRAL AND
WESTERN ZONES INCLUDING KBIL AND KLVM. CONDITIONS WILL IMPROVE
OVER EASTERN AREAS INCLUDING KMLS AND KBHK AFTER 19Z WITH CLEARING
EXPECTED LATE AFTERNOON. LOW STRATUS AND LIGHT SNOW WILL LIKELY
PERSIST INTO EARLY EVENING OVER WESTERN AND CENTRAL AREAS
INCLUDING KBIL AND KSHR...THOUGH CEILINGS WILL LIFT AND BREAKS IN
OVERCAST CAN BE EXPECTED TO INCREASE AS THE AFTERNOON PROGRESSES.
CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 028 015/041 020/042 024/035 023/041 023/042 023/041
7/J 21/U 10/U 22/J 22/J 21/B 12/J
LVM 027 008/041 020/042 028/041 029/042 024/042 024/040
4/J 11/U 21/U 22/W 21/B 11/B 12/J
HDN 030 013/041 017/041 020/036 018/040 022/043 022/041
5/J 11/U 10/U 22/J 22/J 21/B 12/J
MLS 027 013/038 016/037 016/032 017/037 021/040 023/039
1/E 00/U 10/U 01/U 12/J 21/B 12/W
4BQ 027 013/038 016/038 017/032 016/036 020/040 022/039
1/C 11/U 10/U 02/J 22/J 22/W 12/J
BHK 025 007/035 012/028 014/025 011/033 018/037 021/037
0/E 01/U 10/N 00/U 01/B 11/B 12/J
SHR 027 006/040 017/039 019/034 020/037 018/040 021/039
3/J 11/U 11/U 22/J 22/W 21/B 12/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
545 AM EST TUE FEB 7 2012
.SYNOPSIS...
HIGH PRESSURE TUESDAY. A COLD FRONT PASSES WITH AN UPPER DISTURBANCE
TO PROVIDE A COLD RAIN OR SNOW TUESDAY NIGHT AND WEDNESDAY. ARCTIC
AIR WITH SNOW SHOWERS ARRIVES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATED...
NO CHANGES NEEDED FOR 11Z UPDATE. STRATUS DECK ENCROACHING PERRY
CO RIGHT ON TIME.
PREVIOUS DISCUSSION BELOW...
WILL BE WATCHING LOW STRATUS DECK MOVING SE INTO OH EARLY THIS
MORNING. THIS SEEMS BE MARKED BY A WIND SHIFT TO MORE NW IN LWR
LVLS. HI RES LCL MDLS MDLS SEEM TO HAVE A MUCH BETTER HANDLE ON
THIS AS NAM AND GLOBAL MDLS ARE TOO SLOW AND NW WITH THIS. WILL
USE RUC AND WRF MDLS FOR TIMING...POISED TO MOVE INTO
PERRY...MORGAN...VINTON CO 10-12Z BEFORE PUTTING ON THE BRAKES IN
ITS SE ADVANCEMENT. OTHERWISE RVR VALLEY FG CENTRAL AND SOUTHERN
WV/SW VA WILL QUICKLY LIFT BY MID MORNING.
AFOREMENTIONED STRATUS DECK WILL VERY SLOWLY EDGE S AND E THRU THE
DAY...MORE E AND THAN S. HAVE INCREASING CLDS ACROSS NORTHERN WV
LOWLANDS AFTER 18Z. LOOKING AT YET ANOTHER SHARP CLD BOUNDARY
TDY...WITH A MAINLY SUNNY SKY SOUTH OF A KUNI...K3I2...KW22 LINE. AS
A RESULT TRIED TO SHOW MORE OF A TEMP GRADIENT WITH 50-52F SOUTH OF
LINE WITH MID 40S NORTH.
ATTENTION TURNS TO FAST MOVING S/W TROF POISED TO CROSS WED MORNING.
THERE DOES EXIST SOME TIMING DIFF AMONGST THE MODELS WITH GFS ON THE
FAST SIDE. TRIED TO GO TOWARD THE SLOWER SOLUTIONS. USING ISENTROPIC
LIFT FIELDS COMBINED WITH OMEGA IN H85-H7 LYR FOR POPS. THIS KEEPS
CWA DRY THRU 09Z...AMID INCREASING MID/HI CLDS. AFTER WHICH...
QUICKLY RAMP UP POPS FROM W TO E...HAVING HIGH END LKLY TO NEAR A
PKB-CRW-BKW-GRUN LINE AT 12Z. THIS MAY BE A LITTLE FAST AS 06Z NAM
CONT TO SLOW THINGS DOWN A BIT.
AS FOR PRECIP TYPE...MARGINAL WOULD BE AN UNDERSTATEMENT ACROSS
CENTRAL AND SOUTHERN AREAS. EVEN USING THE NAM PROFILES...YIELDS
TEMP CONUNDRUMS BLO H925. COMPOUNDING THE SITUATION IS EXTENT OF
RADIATIONAL COOLING TONIGHT BEFORE MID/HI CLDS PUT A LID ON THINGS.
TRIED TO SHOW A DROP IN TEMPS EARLY THIS EVE BEFORE STABILIZING AND
PERHAPS RISING A DEGREE BEFORE PCPN MOVES IN ACROSS WESTERN HALF OF
CWA. ALSO OF NOTE IS A WARM NOSE H95 TO H9 ALBEIT IN A DRY LYR.
THINKING A BRIEF ONSET OF RA OR A RA/SN MIX ALONG AND S OF I64
CORRIDOR BEFORE WET BULBING IN WARM NOSE COLLAPSES COLUMN AND TRIES
TO SWITCH PCPN OVER TO SN WITH A DEGREE OR TWO DROP IN SFC TEMPS TO
32-34F. HAVE ALLOWED SUCH A TRANSITION ACROSS WESTERN SE OH...NE
KY...WESTERN WV LOWLANDS...AND SW VA BY 12Z. AREAS FURTHER N FROM
ATH-PKB SHOULD START AS SN...WITH NORTHEASTERN QUADRANT STILL DRY AT
12Z. WILL ALLOW FOR A COATING ACROSS NE KY AND PARTS OF SE OH BY
12Z. VERY MUCH A LOW CONFIDENCE FCST AT THIS JUNCTURE WITH CRITICAL
TEMP THRESHOLDS SETTING UP AT THE SFC. COULD VERY WELL END UP BEING
MORE OF A MIX OR RA ON THE VALLEY FLOORS...INCLUDING CRW AND
HTS...WITH WET SNOW ON THE SURROUNDING HILLS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
PRECIPITATION TYPE ON WEDNESDAY IS RATHER TRICKY. BOUNDARY LAYER
COOLING TUESDAY EVENING IS CRITICAL TO THIS FORECAST. NAM SOLUTION
LOOKS FAIRLY REASONABLE...SO WILL STAY CLOSE TO IT...INCLUDING MET
MOS FOR HIGHS WEDNESDAY. THIS WOULD MEAN THAT THE LOW LANDS COULD
BOUNCE BETWEEN RAIN AND SNOW...WHILE THE HIGHER ELEVATIONS OF THE
MOUNTAINS WOULD BE ALL SNOW. ALSO INCREASED POPS TO LIKELY...AS BOTH
NAM AND GFS SHOWING GOOD MOISTURE AND LIFT.
ARCTIC COLD FRONT THEN ARRIVES FRIDAY NIGHT...FOLLOWED BY UPSLOPE
CONDITIONS. INCREASE POPS FOR FRIDAY NIGHT THROUGH SATURDAY
NIGHT...AND LOWERED HIGHS ON SATURDAY.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
OPERATIONAL MODELS ADVERTISING A CLIPPER SYSTEM TO COME THROUGH THE
FIRST PART OF THE WEEKEND. QPF AMOUNTS WILL GENERALLY BE ON THE
LIGHT SIDE...WITH SOME SNOW EXPECTED...BUT SYSTEM WILL BE A QUICK
MOVER. COULD LEAVE SOME LINGERING UPSLOPE ON THE BACK SIDE THROUGH
THE DAY SATURDAY AND EARLY INTO SATURDAY NIGHT. THIS SYSTEM WILL
ALSO SERVE TO USHER IN A MORE WINTER LIKE AIRMASS AS 925MB
TEMPERATURES DROP TO AROUND 10C BELOW ZERO. WILL EXPECT A CLEAR
NIGHT SATURDAY NIGHT...AND WILL SEE MOST LOCATIONS DROPPING INTO THE
TEENS WHILE MOUNTAIN VALLEYS ARE IN THE HUNT FOR SINGLE DIGITS. HIGH
PRESSURE SETTLES IN FOR THE REMAINDER OF THE LONG TERM WITH
TEMPERATURES SLOW TO REBOUND THROUGH THIS PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
ANY FOG ACROSS CENTRAL/SOUTHERN WV AND SW VA WILL QUICKLY LIFT
AND SCT OUT FOR VFR THRU AFTN.
ELSEWHERE...WILL SEE LITTLE PROGRESS IN S AND E ADVANCEMENT OF
STRATUS ACROSS SE OH...UNTIL AFTER 18Z WHEN SOME MVFR CIGS MAY
SNEAK INTO KPKB. THIS STRATUS DECK WILL LIFT SOME WITH AFTN
HEATING.
SOME MID/HI CLDS STREAMING IN AFTER 03Z...WELL AHEAD OF S/W TROF.
MVF/IFR IN RA/SN MIX POSSIBLE BY 12Z ACROSS NE KY...WESTERN
LOWLANDS AND PORTIONS OF SE OH. CONFIDENCE NOT HIGH TO INCLUDE IN
TAFS THIS FAR OUT WITH MDLS TENDING TO SLOW THIS DOWN WITH EACH
RUN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF LOW STRATUS OVER SE OH
COULD VARY THRU 18Z. TIMING OF PCPN TOWARD END OF TAF PERIOD
ACROSS WEST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY L L M H H H H H H H H H
HTS CONSISTENCY M M M H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L L H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H M H
CKB CONSISTENCY H H H H H H H H H H H M
AFTER 12Z WEDNESDAY...
IFR POSSIBLE DUE TO SNOW SHOWERS WEDNESDAY. IFR POSSIBLE IN SNOW
SHOWERS FRIDAY NIGHT THROUGH SATURDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/RPY/30
NEAR TERM...30
SHORT TERM...RPY
LONG TERM...26
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1032 AM EST TUE FEB 7 2012
.SYNOPSIS...
HIGH PRESSURE THIS AFTERNOON. A COLD FRONT PASSES WITH AN UPPER
DISTURBANCE TO PROVIDE A COLD RAIN OR SNOW TUESDAY NIGHT AND
WEDNESDAY. ARCTIC AIR WITH SNOW SHOWERS ARRIVES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATED...
NO CHANGES NEEDED FOR 15Z UPDATE. STRATUS DECK OVER SOUTHEAST OHIO
WILL BE VERY SLOW TO ENCROACH INTO WEST VIRGINIA.
PREVIOUS DISCUSSION BELOW...
WILL BE WATCHING LOW STRATUS DECK MOVING SE INTO OH EARLY THIS
MORNING. THIS SEEMS BE MARKED BY A WIND SHIFT TO MORE NW IN LWR
LVLS. HI RES LCL MDLS MDLS SEEM TO HAVE A MUCH BETTER HANDLE ON
THIS AS NAM AND GLOBAL MDLS ARE TOO SLOW AND NW WITH THIS. WILL
USE RUC AND WRF MDLS FOR TIMING...POISED TO MOVE INTO
PERRY...MORGAN...VINTON CO 10-12Z BEFORE PUTTING ON THE BRAKES IN
ITS SE ADVANCEMENT. OTHERWISE RVR VALLEY FG CENTRAL AND SOUTHERN
WV/SW VA WILL QUICKLY LIFT BY MID MORNING.
AFOREMENTIONED STRATUS DECK WILL VERY SLOWLY EDGE S AND E THRU THE
DAY...MORE E AND THAN S. HAVE INCREASING CLDS ACROSS NORTHERN WV
LOWLANDS AFTER 18Z. LOOKING AT YET ANOTHER SHARP CLD BOUNDARY
TDY...WITH A MAINLY SUNNY SKY SOUTH OF A KUNI...K3I2...KW22 LINE. AS
A RESULT TRIED TO SHOW MORE OF A TEMP GRADIENT WITH 50-52F SOUTH OF
LINE WITH MID 40S NORTH.
ATTENTION TURNS TO FAST MOVING S/W TROF POISED TO CROSS WED MORNING.
THERE DOES EXIST SOME TIMING DIFF AMONGST THE MODELS WITH GFS ON THE
FAST SIDE. TRIED TO GO TOWARD THE SLOWER SOLUTIONS. USING ISENTROPIC
LIFT FIELDS COMBINED WITH OMEGA IN H85-H7 LYR FOR POPS. THIS KEEPS
CWA DRY THRU 09Z...AMID INCREASING MID/HI CLDS. AFTER WHICH...
QUICKLY RAMP UP POPS FROM W TO E...HAVING HIGH END LKLY TO NEAR A
PKB-CRW-BKW-GRUN LINE AT 12Z. THIS MAY BE A LITTLE FAST AS 06Z NAM
CONT TO SLOW THINGS DOWN A BIT.
AS FOR PRECIP TYPE...MARGINAL WOULD BE AN UNDERSTATEMENT ACROSS
CENTRAL AND SOUTHERN AREAS. EVEN USING THE NAM PROFILES...YIELDS
TEMP CONUNDRUMS BLO H925. COMPOUNDING THE SITUATION IS EXTENT OF
RADIATIONAL COOLING TONIGHT BEFORE MID/HI CLDS PUT A LID ON THINGS.
TRIED TO SHOW A DROP IN TEMPS EARLY THIS EVE BEFORE STABILIZING AND
PERHAPS RISING A DEGREE BEFORE PCPN MOVES IN ACROSS WESTERN HALF OF
CWA. ALSO OF NOTE IS A WARM NOSE H95 TO H9 ALBEIT IN A DRY LYR.
THINKING A BRIEF ONSET OF RA OR A RA/SN MIX ALONG AND S OF I64
CORRIDOR BEFORE WET BULBING IN WARM NOSE COLLAPSES COLUMN AND TRIES
TO SWITCH PCPN OVER TO SN WITH A DEGREE OR TWO DROP IN SFC TEMPS TO
32-34F. HAVE ALLOWED SUCH A TRANSITION ACROSS WESTERN SE OH...NE
KY...WESTERN WV LOWLANDS...AND SW VA BY 12Z. AREAS FURTHER N FROM
ATH-PKB SHOULD START AS SN...WITH NORTHEASTERN QUADRANT STILL DRY AT
12Z. WILL ALLOW FOR A COATING ACROSS NE KY AND PARTS OF SE OH BY
12Z. VERY MUCH A LOW CONFIDENCE FCST AT THIS JUNCTURE WITH CRITICAL
TEMP THRESHOLDS SETTING UP AT THE SFC. COULD VERY WELL END UP BEING
MORE OF A MIX OR RA ON THE VALLEY FLOORS...INCLUDING CRW AND
HTS...WITH WET SNOW ON THE SURROUNDING HILLS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
PRECIPITATION TYPE ON WEDNESDAY IS RATHER TRICKY. BOUNDARY LAYER
COOLING TUESDAY EVENING IS CRITICAL TO THIS FORECAST. NAM SOLUTION
LOOKS FAIRLY REASONABLE...SO WILL STAY CLOSE TO IT...INCLUDING MET
MOS FOR HIGHS WEDNESDAY. THIS WOULD MEAN THAT THE LOW LANDS COULD
BOUNCE BETWEEN RAIN AND SNOW...WHILE THE HIGHER ELEVATIONS OF THE
MOUNTAINS WOULD BE ALL SNOW. ALSO INCREASED POPS TO LIKELY...AS BOTH
NAM AND GFS SHOWING GOOD MOISTURE AND LIFT.
ARCTIC COLD FRONT THEN ARRIVES FRIDAY NIGHT...FOLLOWED BY UPSLOPE
CONDITIONS. INCREASE POPS FOR FRIDAY NIGHT THROUGH SATURDAY
NIGHT...AND LOWERED HIGHS ON SATURDAY.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
OPERATIONAL MODELS ADVERTISING A CLIPPER SYSTEM TO COME THROUGH THE
FIRST PART OF THE WEEKEND. QPF AMOUNTS WILL GENERALLY BE ON THE
LIGHT SIDE...WITH SOME SNOW EXPECTED...BUT SYSTEM WILL BE A QUICK
MOVER. COULD LEAVE SOME LINGERING UPSLOPE ON THE BACK SIDE THROUGH
THE DAY SATURDAY AND EARLY INTO SATURDAY NIGHT. THIS SYSTEM WILL
ALSO SERVE TO USHER IN A MORE WINTER LIKE AIRMASS AS 925MB
TEMPERATURES DROP TO AROUND 10C BELOW ZERO. WILL EXPECT A CLEAR
NIGHT SATURDAY NIGHT...AND WILL SEE MOST LOCATIONS DROPPING INTO THE
TEENS WHILE MOUNTAIN VALLEYS ARE IN THE HUNT FOR SINGLE DIGITS. HIGH
PRESSURE SETTLES IN FOR THE REMAINDER OF THE LONG TERM WITH
TEMPERATURES SLOW TO REBOUND THROUGH THIS PERIOD.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
15Z TUESDAY THRU 12Z WEDNESDAY...
THRU 00Z...
WILL SEE LITTLE PROGRESS IN S AND E ADVANCEMENT OF STRATUS ACROSS SE
OH...UNTIL AFTER 18Z WHEN SOME MVFR CIGS MAY SNEAK INTO KPKB. THIS
STRATUS DECK WILL LIFT SOME WITH AFTN HEATING. OTHERWISE...VFR
MOSTLY CLEAR.
SOME MID/HI CLDS STREAMING IN AFTER 00Z...WELL AHEAD OF S/W TROF.
MVFR/IFR IN RA/SN MIX POSSIBLE BY 12Z ACROSS NE KY...WESTERN
LOWLANDS AND PORTIONS OF SE OH. CONFIDENCE NOT HIGH TO INCLUDE IN
TAFS THIS FAR OUT WITH MDLS TENDING TO SLOW THIS DOWN WITH EACH
RUN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF LOW STRATUS OVER SE OH
COULD VARY THRU 00Z. TIMING OF PCPN TOWARD END OF TAF PERIOD
ACROSS WEST.
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 H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H M M M M H
CKB CONSISTENCY H H H H H H H H H H M M
AFTER 18Z WEDNESDAY...
IFR POSSIBLE DUE TO SNOW SHOWERS WEDNESDAY. IFR POSSIBLE IN SNOW
SHOWERS FRIDAY NIGHT THROUGH SATURDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/RPY/30
NEAR TERM...JMV
SHORT TERM...RPY
LONG TERM...26
AVIATION...JMV
AREA FORECAST DISCUSSION...UPDATED
NWS LA CROSSE WI
628 AM CST TUE FEB 7 2012
.SHORT TERM...UPDATE
628 AM CST TUE FEB 7 2012
A SECONDARY COLD FRONT IS DROPPING THROUGH THE REGION AND HAS
BROUGHT A SMALL BAND OF VERY LIGHT DRIZZLE ALONG WITH IT. THESE
LIGHT REFLECTIVITIES CAN BE SEEN ON KARX DROPPING SOUTH ACROSS
WESTERN WISCONSIN AND THROUGH SOUTHEAST MINNESOTA. BASED ON LAPS
SOUNDINGS FROM ACROSS THE REGION...THE SATURATED LAYER IS
SUPERCOOLED AT BETWEEN -3C TO -5C...SO THERE IS NO ICE PRESENT
WITH IT. AS LOW LEVEL TEMPERATURES CONTINUE TO COOL THROUGH THE
MORNING...SOME FLURRIES MAY START TO FALL...BUT DRIZZLE WILL BE
THE MAIN PRECIPITATION TYPE THROUGH AT LEAST THE EARLY MORNING
HOURS HERE. THIS DRIZZLE IS VERY LIGHT BUT WITH TEMPERATURES
BELOW FREEZING THERE IS SOME CONCERN THAT A FEW ICY SPOTS COULD
FORM ON AREA ROADWAYS GOING INTO THE MORNING COMMUTE. ZFP UPDATE
COMING OUT SHORTLY.
TODAY THROUGH THURSDAY NIGHT
316 AM CST TUE FEB 7 2012
MAIN FORECAST CONCERNS ARE ON CLOUDS AND FLURRIES TODAY. FOCUS THEN
TURNS TO TEMPERATURES TONIGHT INTO THURSDAY.
LATEST WATER VAPOR IMAGERY SHOWED A BROAD UPPER LEVEL LOW OVER THE
CENTRAL PLAINS...DRIFTING SOUTHEAST TOWARD THE MIDDLE MISSISSIPPI
RIVER VALLEY. CURRENT SURFACE OBSERVATIONS PLACED A COLD FRONT
STRETCHING FROM NEAR CHICAGO...WEST THROUGH SOUTHERN IOWA. STRATUS
HAS SPREAD ACROSS THE FORECAST AREA IN THE WAKE OF THE
FRONT...PRODUCING CLOUDY SKIES.
IN ADDITION TO THE STRATUS ACROSS THE AREA THIS MORNING....MID TO
HIGH CLOUDS WILL SPREAD ACROSS SOUTHEAST MINNESOTA...NORTHEAST
IOWA...AND FAR SOUTHWEST WISCONSIN AS THE UPPER LOW MOVES FROM THE
CENTRAL PLAINS INTO THE MID MISSISSIPPI RIVER VALLEY. SURFACE HIGH
PRESSURE IS EXPECTED TO GRADUALLY BUILD INTO THE AREA TODAY WITH
THE STRATUS DECK DISSIPATING ACROSS NORTHERN WISCONSIN EARLY THIS
AFTERNOON. THE STRATUS WILL CONTINUE TO DISSIPATE SOUTHWARD THIS
AFTERNOON...TO THE INTERSTATE 90 CORRIDOR BY LATE AFTERNOON INTO
EARLY EVENING. SHOULD SEE A DECREASE IN CLOUDS AS THE HIGH MOVES
IN. HIGH CLOUDS ARE EXPECTED TO LINGER ACROSS NORTHEAST IOWA
THROUGH SOUTHERN WISCONSIN BEFORE FINALLY EXITING TO THE EAST
TONIGHT. FORECAST SOUNDINGS ARE SHOWING THE POTENTIAL FOR SOME
LIGHT FLURRIES ACROSS THE ENTIRE FORECAST AREA THIS
MORNING...SHIFTING SOUTH OF INTERSTATE 90 THIS AFTERNOON. HAVE
KEPT FLURRIES ACROSS NORTHEAST IOWA INTO FAR SOUTHWEST
WISCONSIN...AND REMOVED THEM NORTH OF THESE LOCATIONS FOR THE
AFTERNOON HOURS...GIVEN THE DRY AIR MOVING IN FROM THE NORTH. PLAN
ON HIGH TEMPERATURES RANGING FROM THE THE MID 20S ACROSS NORTH
CENTRAL WISCONSIN TO THE UPPER 20S TO AROUND 30 ACROSS NORTHEAST
IOWA.
THE HIGH WILL BUILD INTO THE FORECAST AREA TONIGHT PROVIDING MOSTLY
CLEAR SKIES AND QUIET WEATHER. LOOK FOR LOWS TO RANGE FROM THE
SINGLE DIGITS ACROSS NORTH CENTRAL WISCONSIN TO THE MID TEENS ACROSS
NORTHEAST IOWA. GIVEN THE DRYNESS OF THE AIRMASS MOVING IN...DEWPOINTS
IN THE SINGLE DIGITS TO SINGLE DIGITS BELOW ZERO...COULD SEE A FEW
LOW LYING AREAS DIP TO AROUND ZERO WITH THE CLEAR SKIES AND IF
WINDS DECOUPLE.
SURFACE HIGH PRESSURE WILL BE IN CONTROL ON WEDNESDAY...WITH MOSTLY
SUNNY SKIES AND HIGH TEMPERATURES RANGING FROM THE MID 20S TO AROUND
30. PLAN ON LIGHT AND VARIABLE WINDS IN THE MORNING...INCREASING TO
8 TO 12 MPH BY LATE MORNING INTO THE AFTERNOON HOURS AS THE HIGH
SLIDES SOUTH AND A COLD FRONT APPROACHES FROM SOUTHERN
MANITOBA/ONTARIO. LOOK FOR LOW TEMPERATURES TO FALL INTO THE TEENS
WEDNESDAY NIGHT UNDER MOSTLY CLEAR SKIES.
CLOUDS WILL INCREASE ACROSS THE FORECAST AREA LATE THURSDAY
AFTERNOON AS THE COLD FRONT/UPPER LEVEL TROUGH APPROACH THE AREA
FROM SOUTHERN CANADA. ONE LAST WARM DAY IS IN STORE ON THURSDAY
BEFORE THE FRONT MOVES IN. PLAN ON HIGH TEMPERATURES IN THE 30S ON
THURSDAY. THE COLD FRONT IS EXPECTED TO MOVE IN THURSDAY NIGHT. NAM
FORECAST SOUNDINGS INDICATE LIGHT SNOW/SNOW SHOWERS MAY DEVELOP
THURSDAY NIGHT AS THE FRONT MOVES IN. THE GFS SUGGESTS THE COLD
FRONTAL PASSAGE WILL LIKELY BE DRY...WITH POSSIBLY A FEW FLURRIES
MOVING THROUGH. WILL MAINTAIN DRY FORECAST GIVEN THE MAJORITY OF
GUIDANCE IS NOT PRODUCING PRECIPITATION...BUT WILL HAVE TO KEEP AN
EYE ON THIS GIVEN HOW COLD THE AIRMASS IS. 850 MB TEMPERATURES ON
THURSDAY ARE AROUND -4 C...THEN FALL TO -16 C LATE THURSDAY NIGHT
INTO EARLY FRIDAY.
.LONG TERM...FRIDAY THROUGH MONDAY
316 AM CST TUE FEB 7 2012
07.00 MODELS SHOW COOL HIGH PRESSURE SETTLING OVER THE AREA ON
FRIDAY WITH TEMPERATURES FALLING TO SLIGHTLY BELOW NORMAL VALUES.
HIGHS ON FRIDAY ARE EXPECTED TO RANGE FROM THE LOWER TEENS ACROSS
NORTHERN WISCONSIN TO THE LOWER 20S ACROSS NORTHEAST IOWA. COOL
TEMPERATURES AND QUIET WEATHER IS ANTICIPATED SATURDAY WITH COOL
HIGH PRESSURE IN PLACE AT THE SURFACE...AND COLD CYCLONIC FLOW
ALOFT ACROSS THE GREAT LAKES. PLAN ON ANOTHER DAY OF HIGHS IN THE
LOWER TEENS TO LOW 20S. LOOK FOR OVERNIGHT LOWS BOTH FRIDAY AND
SATURDAY...TO FALL INTO THE SINGLE DIGITS ABOVE ZERO. LOW LYING
AREAS COULD SEE LOW TEMPERATURES FALL INTO THE SINGLE DIGITS BELOW
ZERO. SLIGHTLY WARMER TEMPERATURES ARE EXPECTED ON SUNDAY AS THE
UPPER TROUGH SLIDES EAST AND A WARMER AIR MASS EDGES IN FROM THE
NORTHERN PLAINS. HIGHS ON SUNDAY WILL RANGE FROM THE LOWER 20S
ACROSS NORTHERN WISCONSIN TO THE UPPER 20S ACROSS NORTHEAST IOWA.
THE SLIGHT WARM UP WILL CONTINUE INTO MONDAY WITH 850 MB
TEMPERATURES WARMING FROM AROUND -15 C ON SUNDAY...TO -10 C ON
MONDAY. GFS/ECMWF SHOW A SHORTWAVE TROUGH MOVING ACROSS THE
CENTRAL/SOUTHERN PLAINS INTO THE MID/LOWER MISSISSIPPI RIVER
VALLEY. HAVE REMOVED PRECIPITATION CHANCES ON MONDAY...GIVEN A
MORE SOUTHERN SOLUTION.
&&
.AVIATION...TODAY AND TONIGHT
530 AM CST TUE FEB 7 2012
THE MAIN FOCUS AT THE TAF SITES IS ON THE 2KFT MVFR STRATUS DECK
THAT IS IN PLACE FROM THE GREAT LAKES WEST THROUGH THE UPPER
MISSISSIPPI RIVER VALLEY AND CENTRAL PLAINS. THESE CLOUDS ARE IN
THE WAKE OF A COLD FRONT THAT HAS DROPPED INTO CENTRAL ILLINOIS
WITH SURFACE WINDS OUT OF THE NORTHEAST AND GUSTING UP TO 20KT.
SOME FLURRIES WILL BE POSSIBLE THIS MORNING...BUT WILL BE LIGHT
ENOUGH THAT VISIBILITY WILL NOT DROP BELOW P6SM.
THE MAIN TASK IS FIGURING OUT WHEN THE MVFR CEILINGS WILL GO VFR
AND CLEAR OUT. 07.10Z RUC FORECAST SOUNDINGS AND 950-850MB
RELATIVE HUMIDITY FIELDS INDICATE THAT THE LOW LEVEL MOISTURE
LIKELY WILL NOT DRY UP UNTIL LATER THIS MORNING DUE TO A MOISTURE FEED
FROM LAKE SUPERIOR. THUS...HAVE PUSHED BACK THE CLIMB OUT OF MVFR
UNTIL LATE THIS AFTERNOON INTO THE EARLY EVENING.
WITH A RIDGE OF HIGH PRESSURE MOVING INTO THE REGION
TONIGHT...WINDS WILL GO LIGHT AND VARIABLE WITH JUST SOME HIGH
LEVEL CLOUD COVER TO CONTEND WITH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
316 AM CST TUE FEB 7 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
530 AM CST TUE FEB 7 2012
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
316 AM CST TUE FEB 7 2012
MAIN FORECAST CONCERNS ARE ON CLOUDS AND FLURRIES TODAY. FOCUS THEN
TURNS TO TEMPERATURES TONIGHT INTO THURSDAY.
LATEST WATER VAPOR IMAGERY SHOWED A BROAD UPPER LEVEL LOW OVER THE
CENTRAL PLAINS...DRIFTING SOUTHEAST TOWARD THE MIDDLE MISSISSIPPI
RIVER VALLEY. CURRENT SURFACE OBSERVATIONS PLACED A COLD FRONT
STRETCHING FROM NEAR CHICAGO...WEST THROUGH SOUTHERN IOWA. STRATUS
HAS SPREAD ACROSS THE FORECAST AREA IN THE WAKE OF THE
FRONT...PRODUCING CLOUDY SKIES.
IN ADDITION TO THE STRATUS ACROSS THE AREA THIS MORNING....MID TO
HIGH CLOUDS WILL SPREAD ACROSS SOUTHEAST MINNESOTA...NORTHEAST
IOWA...AND FAR SOUTHWEST WISCONSIN AS THE UPPER LOW MOVES FROM THE
CENTRAL PLAINS INTO THE MID MISSISSIPPI RIVER VALLEY. SURFACE HIGH
PRESSURE IS EXPECTED TO GRADUALLY BUILD INTO THE AREA TODAY WITH
THE STRATUS DECK DISSIPATING ACROSS NORTHERN WISCONSIN EARLY THIS
AFTERNOON. THE STRATUS WILL CONTINUE TO DISSIPATE SOUTHWARD THIS
AFTERNOON...TO THE INTERSTATE 90 CORRIDOR BY LATE AFTERNOON INTO
EARLY EVENING. SHOULD SEE A DECREASE IN CLOUDS AS THE HIGH MOVES
IN. HIGH CLOUDS ARE EXPECTED TO LINGER ACROSS NORTHEAST IOWA
THROUGH SOUTHERN WISCONSIN BEFORE FINALLY EXITING TO THE EAST
TONIGHT. FORECAST SOUNDINGS ARE SHOWING THE POTENTIAL FOR SOME
LIGHT FLURRIES ACROSS THE ENTIRE FORECAST AREA THIS
MORNING...SHIFTING SOUTH OF INTERSTATE 90 THIS AFTERNOON. HAVE
KEPT FLURRIES ACROSS NORTHEAST IOWA INTO FAR SOUTHWEST
WISCONSIN...AND REMOVED THEM NORTH OF THESE LOCATIONS FOR THE
AFTERNOON HOURS...GIVEN THE DRY AIR MOVING IN FROM THE NORTH. PLAN
ON HIGH TEMPERATURES RANGING FROM THE THE MID 20S ACROSS NORTH
CENTRAL WISCONSIN TO THE UPPER 20S TO AROUND 30 ACROSS NORTHEAST
IOWA.
THE HIGH WILL BUILD INTO THE FORECAST AREA TONIGHT PROVIDING MOSTLY
CLEAR SKIES AND QUIET WEATHER. LOOK FOR LOWS TO RANGE FROM THE
SINGLE DIGITS ACROSS NORTH CENTRAL WISCONSIN TO THE MID TEENS ACROSS
NORTHEAST IOWA. GIVEN THE DRYNESS OF THE AIRMASS MOVING IN...DEWPOINTS
IN THE SINGLE DIGITS TO SINGLE DIGITS BELOW ZERO...COULD SEE A FEW
LOW LYING AREAS DIP TO AROUND ZERO WITH THE CLEAR SKIES AND IF
WINDS DECOUPLE.
SURFACE HIGH PRESSURE WILL BE IN CONTROL ON WEDNESDAY...WITH MOSTLY
SUNNY SKIES AND HIGH TEMPERATURES RANGING FROM THE MID 20S TO AROUND
30. PLAN ON LIGHT AND VARIABLE WINDS IN THE MORNING...INCREASING TO
8 TO 12 MPH BY LATE MORNING INTO THE AFTERNOON HOURS AS THE HIGH
SLIDES SOUTH AND A COLD FRONT APPROACHES FROM SOUTHERN
MANITOBA/ONTARIO. LOOK FOR LOW TEMPERATURES TO FALL INTO THE TEENS
WEDNESDAY NIGHT UNDER MOSTLY CLEAR SKIES.
CLOUDS WILL INCREASE ACROSS THE FORECAST AREA LATE THURSDAY
AFTERNOON AS THE COLD FRONT/UPPER LEVEL TROUGH APPROACH THE AREA
FROM SOUTHERN CANADA. ONE LAST WARM DAY IS IN STORE ON THURSDAY
BEFORE THE FRONT MOVES IN. PLAN ON HIGH TEMPERATURES IN THE 30S ON
THURSDAY. THE COLD FRONT IS EXPECTED TO MOVE IN THURSDAY NIGHT. NAM
FORECAST SOUNDINGS INDICATE LIGHT SNOW/SNOW SHOWERS MAY DEVELOP
THURSDAY NIGHT AS THE FRONT MOVES IN. THE GFS SUGGESTS THE COLD
FRONTAL PASSAGE WILL LIKELY BE DRY...WITH POSSIBLY A FEW FLURRIES
MOVING THROUGH. WILL MAINTAIN DRY FORECAST GIVEN THE MAJORITY OF
GUIDANCE IS NOT PRODUCING PRECIPITATION...BUT WILL HAVE TO KEEP AN
EYE ON THIS GIVEN HOW COLD THE AIRMASS IS. 850 MB TEMPERATURES ON
THURSDAY ARE AROUND -4 C...THEN FALL TO -16 C LATE THURSDAY NIGHT
INTO EARLY FRIDAY.
.LONG TERM...FRIDAY THROUGH MONDAY
316 AM CST TUE FEB 7 2012
07.00 MODELS SHOW COOL HIGH PRESSURE SETTLING OVER THE AREA ON
FRIDAY WITH TEMPERATURES FALLING TO SLIGHTLY BELOW NORMAL VALUES.
HIGHS ON FRIDAY ARE EXPECTED TO RANGE FROM THE LOWER TEENS ACROSS
NORTHERN WISCONSIN TO THE LOWER 20S ACROSS NORTHEAST IOWA. COOL
TEMPERATURES AND QUIET WEATHER IS ANTICIPATED SATURDAY WITH COOL
HIGH PRESSURE IN PLACE AT THE SURFACE...AND COLD CYCLONIC FLOW
ALOFT ACROSS THE GREAT LAKES. PLAN ON ANOTHER DAY OF HIGHS IN THE
LOWER TEENS TO LOW 20S. LOOK FOR OVERNIGHT LOWS BOTH FRIDAY AND
SATURDAY...TO FALL INTO THE SINGLE DIGITS ABOVE ZERO. LOW LYING
AREAS COULD SEE LOW TEMPERATURES FALL INTO THE SINGLE DIGITS BELOW
ZERO. SLIGHTLY WARMER TEMPERATURES ARE EXPECTED ON SUNDAY AS THE
UPPER TROUGH SLIDES EAST AND A WARMER AIR MASS EDGES IN FROM THE
NORTHERN PLAINS. HIGHS ON SUNDAY WILL RANGE FROM THE LOWER 20S
ACROSS NORTHERN WISCONSIN TO THE UPPER 20S ACROSS NORTHEAST IOWA.
THE SLIGHT WARM UP WILL CONTINUE INTO MONDAY WITH 850 MB
TEMPERATURES WARMING FROM AROUND -15 C ON SUNDAY...TO -10 C ON
MONDAY. GFS/ECMWF SHOW A SHORTWAVE TROUGH MOVING ACROSS THE
CENTRAL/SOUTHERN PLAINS INTO THE MID/LOWER MISSISSIPPI RIVER
VALLEY. HAVE REMOVED PRECIPITATION CHANCES ON MONDAY...GIVEN A
MORE SOUTHERN SOLUTION.
&&
.AVIATION...TODAY AND TONIGHT
530 AM CST TUE FEB 7 2012
THE MAIN FOCUS AT THE TAF SITES IS ON THE 2KFT MVFR STRATUS DECK
THAT IS IN PLACE FROM THE GREAT LAKES WEST THROUGH THE UPPER
MISSISSIPPI RIVER VALLEY AND CENTRAL PLAINS. THESE CLOUDS ARE IN
THE WAKE OF A COLD FRONT THAT HAS DROPPED INTO CENTRAL ILLINOIS
WITH SURFACE WINDS OUT OF THE NORTHEAST AND GUSTING UP TO 20KT.
SOME FLURRIES WILL BE POSSIBLE THIS MORNING...BUT WILL BE LIGHT
ENOUGH THAT VISIBILITY WILL NOT DROP BELOW P6SM.
THE MAIN TASK IS FIGURING OUT WHEN THE MVFR CEILINGS WILL GO VFR
AND CLEAR OUT. 07.10Z RUC FORECAST SOUNDINGS AND 950-850MB
RELATIVE HUMIDITY FIELDS INDICATE THAT THE LOW LEVEL MOISTURE
LIKELY WILL NOT DRY UP UNTIL LATER THIS MORNING DUE TO A MOISTURE FEED
FROM LAKE SUPERIOR. THUS...HAVE PUSHED BACK THE CLIMB OUT OF MVFR
UNTIL LATE THIS AFTERNOON INTO THE EARLY EVENING.
WITH A RIDGE OF HIGH PRESSURE MOVING INTO THE REGION
TONIGHT...WINDS WILL GO LIGHT AND VARIABLE WITH JUST SOME HIGH
LEVEL CLOUD COVER TO CONTEND WITH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
316 AM CST TUE FEB 7 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1207 PM MST TUE FEB 7 2012
.UPDATE...
HAVE ADJUSTED GRIDS/ZONES TO ACCOUNT FOR LINGERING CLOUDS/ISOLATED
SNOW SHOWERS OVER EASTERN SECTIONS OF THE FORECAST DISTRICT.
&&
.PREV DISCUSSION... /ISSUED 1053 AM MST TUE FEB 7 2012/
AVIATION...
ISOLATED GENERALLY LIGHT SNOW SHOWERS ARE EXPECTED TO CONTINUE
THROUGH LATE THIS MORNING WITH VFR CONDITIONS THEN EXPECTED TO
RETURN TO THE KALS...KCOS AND KPUB TAF SITES AFT 22Z TODAY.
PREV DISCUSSION... /ISSUED 437 AM MST TUE FEB 7 2012/
SHORT TERM...
(TODAY AND TONIGHT)
.COLD WEATHER THROUGH TONIGHT....
CURRENTLY...SOME LIGHT SHSN OVR OTERO AND SRN PUEBLO COUNTIES.
COULD SEE SOME MINOR ACCUMS THIS MORNING S OF HWY 50...ESPECIALLY
OVR THE RATON MESA. MODELS HAVE NOT HANDLED THIS PRECIP VERY
WELL...BUT THE RUC HAS THE SNOW PRETTY WELL DEPICTED...AND IT MOVES
MOST OF THE PRECIP OUT OF OUR AREA BY 15Z. THIS LOOKS REASONABLE
WITH THE UPPER LOW CONTINUING TO TRANSLATE INTO NE AND NW KS.
MAIN STORY TODAY WILL BE THE COLD. TEMPS HAVE NOT FALLEN MUCH OVR
THE PLAINS THIS MORN...AS OF 3 AM IT IS STILL IN THE UPPR 20 FOR
MANY SPOTS...THANKS TO THE PRECIP...LOW CLOUDS...AND WIND.
HOWEVER...WITH H7 TEMPS NOW BOTTOMING OUT IN THE MINUS 13 TO 14
RANGE...WILL NOT SEE MUCH WARMING TODAY DESPITE CLEARING SKIES THIS
AFTERNOON. A FEW SPOTS COULD RISE ABOVE FREEZING BUT OTHERWISE IT
WILL STAY IN THE UPPER 20S FOR MUCH OF THE DAY. A STRONG SURFACE
HIGH OVR THE DAKOTAS WILL CONTINUE TO SLIDE SWD THROUGH THIS
EVENING...AND THIS WILL KEEP LIGHT UPSLOPE WINDS OVER SE CO THRU
TONIGHT. DESPITE RISING TEMPS ALOFT...AS A WEAK RIDGE BUILDS BRIEFLY
OVR THE AREA...EXPECT A STRONGLY DECOUPLED BL TONIGHT...WITH TEMPS
NEARING OR DROPPING BELOW ZERO FOR SOME OF THE HIGH VALLEY COLD
SPOTS. COULD ALSO SEE TEMPS NR ZERO OVER THE LOWER ARKANSAS WITH
CLEARING SKIES AND LIGHT WINDS TONIGHT. POPS WILL REMAIN NR ZERO
THRU WED MORNING. SOME HIGH CLOUDS WILL BEGIN MOVING INTO THE SW MTS
BY SUNRISE WED...AS THE NEXT SHORT WAVE TROUGH APPROACHES FROM THE
W. 44
LONG TERM...
(WEDNESDAY THROUGH MONDAY)
SLOW WARMING TREND BEGINS WEDNESDAY AHEAD OF WEAK UPPER TROUGH
SHEARING SOUTH THROUGH THE GREAT BASIN. EXPECT A FEW -SHSN TO
DEVELOP ALONG THE CONTINENTAL DIVIDE WED AFTERNOON...PERSISTING
THROUGH THE DAY THU AS SYSTEM SLOWLY DROPS SOUTH. DYNAMICS LOOK
WEAK AND MOISTURE IS LIMITED...SO NOT EXPECTING MORE THAN SCATTERED
SNOW SHOWERS WITH THE SYSTEM AT THIS POINT. MODELS HINT AT A FEW
SHOWERS OVER THE SANGRES THU MORNING...SO WILL KEEP SOME ISOLATED
POPS IN PLACE SOUTH OF LA VETA PASS. MAX TEMPS WED SHOULD WARM
10-15F VERSUS TODAY`S (TUE) NUMBERS...THEN ADD ANOTHER 3-5F THU AS
BETTER MIXING WILL LIKELY OFFSET MINOR COLD ADVECTION. FRI-SAT
LOOK MAINLY DRY AND SEASONABLE...AS WESTERN EDGE OF ARCTIC AIR
MASS OVER THE CENTRAL PLAINS STAYS EAST OF THE KS BORDER. NEW
WESTERN TROUGH TAKES SHAPE SUN...THOUGH DETAILS VARY AS 06Z GFS
TAKES SYSTEM FARTHER SOUTH AND HAS LESS IMPACT THAN RATHER SNOWY
00Z RUN. IN GENERAL...EXTENDED PROCEDURE GRIDS BEGIN A GRADUAL
TREND TOWARD COLDER/WETTER WEATHER SUN/MON...THOUGH IF TRENDS
CONTINUE...MAY NEED TO RAISE POPS/LOWER TEMPS MORE SUBSTANTIALLY IN
SUBSEQUENT FORECASTS. --10
AVIATION...ISOLD LIGHT SHSN WILL PERSIST THROUGH THIS
MORNING...ENDING BY 13-15Z FOR AREAS VC KCOS AND KALS. AT THE
SAME TOME...N WINDS AT KCOS AND KPUB SHOULD RELAX BY MID
MORNING...AND WILL REMAIN LIGHT AND FROM THE E TO SE THROUGH TODAY
AND INTO TONIGHT. 44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1053 AM MST TUE FEB 7 2012
&&
.AVIATION...
ISOLATED GENERALLY LIGHT SNOW SHOWERS ARE EXPECTED TO CONTINUE
THROUGH LATE THIS MORNING WITH VFR CONDITIONS THEN EXPECTED TO
RETURN TO THE KALS...KCOS AND KPUB TAF SITES AFT 22Z TODAY.
&&
.PREV DISCUSSION... /ISSUED 437 AM MST TUE FEB 7 2012/
SHORT TERM...
(TODAY AND TONIGHT)
..COLD WEATHER THROUGH TONIGHT....
CURRENTLY...SOME LIGHT SHSN OVR OTERO AND SRN PUEBLO COUNTIES.
COULD SEE SOME MINOR ACCUMS THIS MORNING S OF HWY 50...ESPECIALLY
OVR THE RATON MESA. MODELS HAVE NOT HANDLED THIS PRECIP VERY
WELL...BUT THE RUC HAS THE SNOW PRETTY WELL DEPICTED...AND IT MOVES
MOST OF THE PRECIP OUT OF OUR AREA BY 15Z. THIS LOOKS REASONABLE
WITH THE UPPER LOW CONTINUING TO TRANSLATE INTO NE AND NW KS.
MAIN STORY TODAY WILL BE THE COLD. TEMPS HAVE NOT FALLEN MUCH OVR
THE PLAINS THIS MORN...AS OF 3 AM IT IS STILL IN THE UPPR 20 FOR
MANY SPOTS...THANKS TO THE PRECIP...LOW CLOUDS...AND WIND.
HOWEVER...WITH H7 TEMPS NOW BOTTOMING OUT IN THE MINUS 13 TO 14
RANGE...WILL NOT SEE MUCH WARMING TODAY DESPITE CLEARING SKIES THIS
AFTERNOON. A FEW SPOTS COULD RISE ABOVE FREEZING BUT OTHERWISE IT
WILL STAY IN THE UPPER 20S FOR MUCH OF THE DAY. A STRONG SURFACE
HIGH OVR THE DAKOTAS WILL CONTINUE TO SLIDE SWD THROUGH THIS
EVENING...AND THIS WILL KEEP LIGHT UPSLOPE WINDS OVER SE CO THRU
TONIGHT. DESPITE RISING TEMPS ALOFT...AS A WEAK RIDGE BUILDS BRIEFLY
OVR THE AREA...EXPECT A STRONGLY DECOUPLED BL TONIGHT...WITH TEMPS
NEARING OR DROPPING BELOW ZERO FOR SOME OF THE HIGH VALLEY COLD
SPOTS. COULD ALSO SEE TEMPS NR ZERO OVER THE LOWER ARKANSAS WITH
CLEARING SKIES AND LIGHT WINDS TONIGHT. POPS WILL REMAIN NR ZERO
THRU WED MORNING. SOME HIGH CLOUDS WILL BEGIN MOVING INTO THE SW MTS
BY SUNRISE WED...AS THE NEXT SHORT WAVE TROUGH APPROACHES FROM THE
W. 44
LONG TERM...
(WEDNESDAY THROUGH MONDAY)
SLOW WARMING TREND BEGINS WEDNESDAY AHEAD OF WEAK UPPER TROUGH
SHEARING SOUTH THROUGH THE GREAT BASIN. EXPECT A FEW -SHSN TO
DEVELOP ALONG THE CONTINENTAL DIVIDE WED AFTERNOON...PERSISTING
THROUGH THE DAY THU AS SYSTEM SLOWLY DROPS SOUTH. DYNAMICS LOOK
WEAK AND MOISTURE IS LIMITED...SO NOT EXPECTING MORE THAN SCATTERED
SNOW SHOWERS WITH THE SYSTEM AT THIS POINT. MODELS HINT AT A FEW
SHOWERS OVER THE SANGRES THU MORNING...SO WILL KEEP SOME ISOLATED
POPS IN PLACE SOUTH OF LA VETA PASS. MAX TEMPS WED SHOULD WARM
10-15F VERSUS TODAY`S (TUE) NUMBERS...THEN ADD ANOTHER 3-5F THU AS
BETTER MIXING WILL LIKELY OFFSET MINOR COLD ADVECTION. FRI-SAT
LOOK MAINLY DRY AND SEASONABLE...AS WESTERN EDGE OF ARCTIC AIR
MASS OVER THE CENTRAL PLAINS STAYS EAST OF THE KS BORDER. NEW
WESTERN TROUGH TAKES SHAPE SUN...THOUGH DETAILS VARY AS 06Z GFS
TAKES SYSTEM FARTHER SOUTH AND HAS LESS IMPACT THAN RATHER SNOWY
00Z RUN. IN GENERAL...EXTENDED PROCEDURE GRIDS BEGIN A GRADUAL
TREND TOWARD COLDER/WETTER WEATHER SUN/MON...THOUGH IF TRENDS
CONTINUE...MAY NEED TO RAISE POPS/LOWER TEMPS MORE SUBSTANTIALLY IN
SUBSEQUENT FORECASTS. --10
AVIATION...ISOLD LIGHT SHSN WILL PERSIST THROUGH THIS
MORNING...ENDING BY 13-15Z FOR AREAS VC KCOS AND KALS. AT THE
SAME TOME...N WINDS AT KCOS AND KPUB SHOULD RELAX BY MID
MORNING...AND WILL REMAIN LIGHT AND FROM THE E TO SE THROUGH TODAY
AND INTO TONIGHT. 44
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
545 PM EST TUE FEB 7 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...AN UPPER DISTURBANCE WILL MOVE THROUGH CENTRAL INDIANA
OVERNIGHT AND EARLY WEDNESDAY MORNING BRINGING MEASURABLE SNOW TO
MUCH OF THE AREA FOR THE MORNING COMMUTE. BY WEDNESDAY AFTERNOON
HIGH PRESSURE RIDGING WILL BUILD INTO THE AREA AND BRING DRY WEATHER
UNTIL THE NEXT WAVE ARRIVES ON FRIDAY WITH MORE CHANCES FOR SNOW
THROUGH FRIDAY NIGHT. AFTER THAT THE WEATHER WILL BE QUIET UNTIL THE
NEXT WAVE APPROACHES FOR MONDAY NIGHT.
&&
.NEAR TERM /TONIGHT INTO WEDNESDAY MORNING/...
FORECAST FOCUS IS ON POPS/TIMING/SNOWFALL AMOUNTS WITH RESPECT TO UPPER
WAVE MOVING THROUGH OVERNIGHT. CONFIDENCE IN ACCUMULATING SNOWFALL
OCCURRING OVER MUCH OF CENTRAL INDIANA HAS INCREASED WITH LATEST
MODEL RUNS AS UPPER FORCING SHOWN OVER LAST FEW DAYS IS STILL THERE
BUT IS NOW JOINED BY VERY WEAK FRONTOGENESIS...INCREASED DEEP LAYER
MOISTURE...AND A BIT OF INSTABILITY. GFS/NAM/SREFS/ECMWF ALL IN
AGREEMENT ON THIS WAVE AND SOME MEASURABLE QPF AS WELL. THIS WAVE
WILL COME TOGETHER AND MOVE ACROSS SOUTHERN INDIANA DURING THE
OVERNIGHT HOURS INTO THE MORNING. CONSENSUS OF TIMING SHOWS BEST
FORCING OVER THE AREA BETWEEN 9 AND 15Z SO CONFINED HIGHEST POPS TO
THAT TIME WITH LOW CHANCES IN THE NORTHEAST INCREASING TO LIKELIES
ALONG I70 AND SOUTH AND FINALLY CATEGORICAL SNOW IN THE FAR SOUTH.
PRIOR TO THIS WILL SLOWLY RAMP POPS UP WITH ONLY SLIGHT CHANCE PRIOR
TO 6Z AND THEN CHANCES SPREADING NORTHEAST OVER THE AREA FROM 6-9Z.
AS FAR AS PRECIPITATION TYPE IS CONCERNED...MOST MODEL FIELDS ARE
INDICATING ALL SNOW FOR THE ENTIRE AREA...BUT NAM THICKNESSES START
OUT MARGINAL AND RUC SOUNDINGS SHOW POTENTIAL FOR A RAIN SNOW MIX
EARLY IN THE SOUTH. THEREFORE WILL CARRY LOW CHANCES FOR A RAIN SNOW
MIX IN THE SOUTHERN TWO TIERS THROUGH 6Z AND ALL SNOW THEREAFTER.
AS FAR AS AMOUNTS ARE CONCERNED...WITH THE BEST FORCING IN THE SOUTH
WILL GO WITH HIGHEST AMOUNTS THERE. GENERALLY AROUND AN INCH TOTAL
IN THE SOUTH WITH LOCALLY HIGHER AMOUNTS POSSIBLE...HALF AN INCH TO
AN INCH CENTRAL...AND ONLY AROUND A TENTH OF AN INCH IN THE
NORTHWEST IF ANY ACCUMULATION AT ALL AS IT IS FURTHEST FROM THE
FORCING. WHILE HIGHEST AMOUNTS ARE ONLY AROUND AN INCH THE TIMING
WILL BE PROBLEMATIC AS SNOW WILL BEGIN IN THE WEE HOURS OF THE
MORNING AND CONTINUE THROUGH MID MORNING...IMPACTING THE MORNING
COMMUTE. WILL ISSUE AN SPS TO HIGHLIGHT THE TIMING FACTOR.
FOR LOW TEMPERATURES GUIDANCE WAS IN GOOD AGREEMENT SO USED AN
AVERAGE IN THE MID 20S TO LOW 30S.
&&
.SHORT TERM /WEDNESDAY AFTERNOON THROUGH FRIDAY/...
MODELS ARE IN GOOD AGREEMENT SO WILL USE A CONSENSUS APPROACH. THE
UPPER WAVE IS THROUGH THE AREA BY WEDNESDAY AFTERNOON WITH UPPER
RIDGING MOVING INTO THE AREA. THIS WILL KEEP THINGS DRY UNTIL FRIDAY
WHEN ANOTHER WAVE APPROACHES AND BRINGS LOW CHANCES FOR SNOW. FOR
TEMPERATURES GENERALLY WENT NEAR A GUIDANCE AVERAGE...BUT USED
TEMPERATURES COOLER THAN GUIDANCE FOR WEDNESDAY AND FRIDAY HIGHS
WITH COLD ADVECTION AND EXPECTED CLOUD COVER. THIS YIELDED
TEMPERATURES NEAR AVERAGE FOR THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE BEST CHANCES OF PRECIP WILL BE DURING THE FRIDAY NIGHT PERIOD AS
A STRONG UPPER TROUGH ROTATES EAST ACROSS THE GREAT LAKES AND AGAIN
TOWARDS MONDAY NIGHT WARM ADVECTION INCREASES AND A WEAK UPPER LEVEL
DISTURBANCE MOVES THROUGH THE OHIO VALLEY.
WENT PRETTY MUCH TO ALL BLEND POPS FRIDAY NIGHT. BUT IN THE NORTH I
INCREASED THEM A LITTLE AS THERE COULD BE SOME LAKE ENHANCEMENT.
THIS LAKE ENHANCEMENT MAY LINGER INTO SATURDAY SO KEPT SLIGHT
CHANCES ACROSS MUCH OF OUR FAR NORTH. MODELS HAVE TRENDED COLDER
OVER THE WEEKEND AND WENT CLOSER TO THE CONSALL NUMBERS AS THE COLD
UPPER TROUGH MOVES ACROSS THE GREAT LAKES OVER THE WEEKEND.
HIGH PRESSURE WILL MOVE ACROSS OUR REGION SUNDAY AND WARM ADVECTION
STARTS MONDAY. MODELS HAVE TRENDED SLOWER...SO WILL ONLY MENTION
SLIGHT CHANCE OF PRECIP ACROSS OUR FAR SOUTHWEST LATE MONDAY.
MOST MODELS PRODUCE LIGHT PRECIP AMOUNTS AND THICKNESS SHOULD BE LOW
ENOUGH FOR MOSTLY SNOW NORTH AND CENTRAL MONDAY NIGHT. RAISED
TEMPERATURES A LITTLE WITH CLOUDS AND WARM ADVECTION MONDAY NIGHT.
ALL BLEND TEMPERATURES MAY BE A TAD WARM TUESDAY AS THERE WILL BE
LOTS OF CLOUDS. BUT ONLY CHANGE I MADE WAS TO LOWER THE NORTH HALF
A FEW DEGREES IN CASE THERE WAS SOME LEFT OVER SNOWFALL FROM MONDAY
NIGHT.
&&
.AVIATION /DISCUSSION FOR THE 080000Z TAFS/...
LOWER CONFIDENCE CEILING FORECAST THIS EVENING AS THE EDGE OF AN
MVFR DECK EXISTS BETWEEN KIND/KHUF/KBMG. THE EDGE HAS BEEN
RETREATING A BIT TO THE NORTHEAST OVER THE PAST COUPLE OF
HOURS...HOWEVER THE LOW LEVEL NORTHEAST FLOW AND SHORT TERM MODELS
SUGGEST THE EDGE WILL BEGIN DRIFTING BACK TO THE SOUTHWEST LATER
THIS EVENING. FOR NOW WILL KEEP MVFR CEILINGS AT KLAF/KIND...AND GO
WITH TEMPORARY MVFR CEILINGS AT KHUF/KBMG...WITH PREVIALING MVFR
CEILINGS OVERSPREADING ALL THE TAF SITES BY 080500Z.
OTHER ITEM OF INTEREST OVERNIGHT WILL BE THE SYSTEM CURRENTLY MOVING
THROUGH IOWA AND MISSOURI. HIGHER RESOLUTION SHORT TERM MODELS
SUGGEST THERE IS GOOD POTENTIAL FOR FAIRLY WIDESPREAD IFR VISIBILITY
RESTRICTIONS IN LIGHT SNOW ACROSS THE AREA AFTER ABOUT 080900Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....JH
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
337 PM EST TUE FEB 7 2012
.UPDATE...
AVIATION SECTIONS UPDATED
&&
.SYNOPSIS...AN UPPER DISTURBANCE WILL MOVE THROUGH CENTRAL INDIANA OVERNIGHT AND
EARLY WEDNESDAY MORNING BRINGING MEASURABLE SNOW TO MUCH OF THE AREA
FOR THE MORNING COMMUTE. BY WEDNESDAY AFTERNOON HIGH PRESSURE
RIDGING WILL BUILD INTO THE AREA AND BRING DRY WEATHER UNTIL THE
NEXT WAVE ARRIVES ON FRIDAY WITH MORE CHANCES FOR SNOW THROUGH
FRIDAY NIGHT. AFTER THAT THE WEATHER WILL BE QUIET UNTIL THE NEXT
WAVE APPROACHES FOR MONDAY NIGHT.
&&
.NEAR TERM /TONIGHT INTO WEDNESDAY MORNING/...
FORECAST FOCUS IS ON POPS/TIMING/SNOWFALL AMOUNTS WITH RESPECT TO UPPER
WAVE MOVING THROUGH OVERNIGHT. CONFIDENCE IN ACCUMULATING SNOWFALL
OCCURRING OVER MUCH OF CENTRAL INDIANA HAS INCREASED WITH LATEST
MODEL RUNS AS UPPER FORCING SHOWN OVER LAST FEW DAYS IS STILL THERE
BUT IS NOW JOINED BY VERY WEAK FRONTOGENESIS...INCREASED DEEP LAYER
MOISTURE...AND A BIT OF INSTABILITY. GFS/NAM/SREFS/ECMWF ALL IN
AGREEMENT ON THIS WAVE AND SOME MEASURABLE QPF AS WELL. THIS WAVE
WILL COME TOGETHER AND MOVE ACROSS SOUTHERN INDIANA DURING THE
OVERNIGHT HOURS INTO THE MORNING. CONSENSUS OF TIMING SHOWS BEST
FORCING OVER THE AREA BETWEEN 9 AND 15Z SO CONFINED HIGHEST POPS TO
THAT TIME WITH LOW CHANCES IN THE NORTHEAST INCREASING TO LIKELIES
ALONG I70 AND SOUTH AND FINALLY CATEGORICAL SNOW IN THE FAR SOUTH.
PRIOR TO THIS WILL SLOWLY RAMP POPS UP WITH ONLY SLIGHT CHANCE PRIOR
TO 6Z AND THEN CHANCES SPREADING NORTHEAST OVER THE AREA FROM 6-9Z.
AS FAR AS PRECIPITATION TYPE IS CONCERNED...MOST MODEL FIELDS ARE
INDICATING ALL SNOW FOR THE ENTIRE AREA...BUT NAM THICKNESSES START
OUT MARGINAL AND RUC SOUNDINGS SHOW POTENTIAL FOR A RAIN SNOW MIX
EARLY IN THE SOUTH. THEREFORE WILL CARRY LOW CHANCES FOR A RAIN SNOW
MIX IN THE SOUTHERN TWO TIERS THROUGH 6Z AND ALL SNOW THEREAFTER.
AS FAR AS AMOUNTS ARE CONCERNED...WITH THE BEST FORCING IN THE SOUTH
WILL GO WITH HIGHEST AMOUNTS THERE. GENERALLY AROUND AN INCH TOTAL
IN THE SOUTH WITH LOCALLY HIGHER AMOUNTS POSSIBLE...HALF AN INCH TO
AN INCH CENTRAL...AND ONLY AROUND A TENTH OF AN INCH IN THE
NORTHWEST IF ANY ACCUMULATION AT ALL AS IT IS FURTHEST FROM THE
FORCING. WHILE HIGHEST AMOUNTS ARE ONLY AROUND AN INCH THE TIMING
WILL BE PROBLEMATIC AS SNOW WILL BEGIN IN THE WEE HOURS OF THE
MORNING AND CONTINUE THROUGH MID MORNING...IMPACTING THE MORNING
COMMUTE. WILL ISSUE AN SPS TO HIGHLIGHT THE TIMING FACTOR.
FOR LOW TEMPERATURES GUIDANCE WAS IN GOOD AGREEMENT SO USED AN
AVERAGE IN THE MID 20S TO LOW 30S.
&&
.SHORT TERM /WEDNESDAY AFTERNOON THROUGH FRIDAY/...
MODELS ARE IN GOOD AGREEMENT SO WILL USE A CONSENSUS APPROACH. THE
UPPER WAVE IS THROUGH THE AREA BY WEDNESDAY AFTERNOON WITH UPPER
RIDGING MOVING INTO THE AREA. THIS WILL KEEP THINGS DRY UNTIL FRIDAY
WHEN ANOTHER WAVE APPROACHES AND BRINGS LOW CHANCES FOR SNOW. FOR
TEMPERATURES GENERALLY WENT NEAR A GUIDANCE AVERAGE...BUT USED
TEMPERATURES COOLER THAN GUIDANCE FOR WEDNESDAY AND FRIDAY HIGHS
WITH COLD ADVECTION AND EXPECTED CLOUD COVER. THIS YIELDED
TEMPERATURES NEAR AVERAGE FOR THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE BEST CHANCES OF PRECIP WILL BE DURING THE FRIDAY NIGHT PERIOD AS
A STRONG UPPER TROUGH ROTATES EAST ACROSS THE GREAT LAKES AND AGAIN
TOWARDS MONDAY NIGHT WARM ADVECTION INCREASES AND A WEAK UPPER LEVEL
DISTURBANCE MOVES THROUGH THE OHIO VALLEY.
WENT PRETTY MUCH TO ALL BLEND POPS FRIDAY NIGHT. BUT IN THE NORTH I
INCREASED THEM A LITTLE AS THERE COULD BE SOME LAKE ENHANCEMENT.
THIS LAKE ENHANCEMENT MAY LINGER INTO SATURDAY SO KEPT SLIGHT
CHANCES ACROSS MUCH OF OUR FAR NORTH. MODELS HAVE TRENDED COLDER
OVER THE WEEKEND AND WENT CLOSER TO THE CONSALL NUMBERS AS THE COLD
UPPER TROUGH MOVES ACROSS THE GREAT LAKES OVER THE WEEKEND.
HIGH PRESSURE WILL MOVE ACROSS OUR REGION SUNDAY AND WARM ADVECTION
STARTS MONDAY. MODELS HAVE TRENDED SLOWER...SO WILL ONLY MENTION
SLIGHT CHANCE OF PRECIP ACROSS OUR FAR SOUTHWEST LATE MONDAY.
MOST MODELS PRODUCE LIGHT PRECIP AMOUNTS AND THICKNESS SHOULD BE LOW
ENOUGH FOR MOSTLY SNOW NORTH AND CENTRAL MONDAY NIGHT. RAISED
TEMPERATURES A LITTLE WITH CLOUDS AND WARM ADVECTION MONDAY NIGHT.
ALL BLEND TEMPERATURES MAY BE A TAD WARM TUESDAY AS THERE WILL BE
LOTS OF CLOUDS. BUT ONLY CHANGE I MADE WAS TO LOWER THE NORTH HALF
A FEW DEGREES IN CASE THERE WAS SOME LEFT OVER SNOWFALL FROM MONDAY
NIGHT.
&&
.AVIATION /DISCUSSION FOR THE 21Z IND TAF UPDATE/...
EXTENSIVE MVFR CIGS REMAIN OVER THE IND TAF SITE AS WELL AS
UPSTREAM...THUS HAVE ELECTED TO PUSH BACK THE BRIEF PERIOD OF
3000 FT CIGS UNTIL EARLY THIS EVENING.
PREVIOUS DISCUSSION BELOW
/DISCUSSION FOR 071800Z TAF ISSUANCE/...
MVFR CEILINGS WITH STRATUS WERE THE RULE OVER MUCH OF THE REGION AT
MIDDAY. THERE ARE SOME SIGNS KBMG MAY BEGINNING TO BREAK OUT OF THE
STRATUS AS THE THE SOUTHERN PORTIONS BEGINS ERODING. OTHER SITES
COULD SCATTER OUT BY LATE AFTERNOON. BUT MODEL SOUNDINGS STILL SHOW
A SOMEWHAT MOIST LAYER RIGHT UNDER A LOW LEVEL INVERSION. SO FOR NOW
WILL KEEP MOST OTHER AREAS BROKEN WITH POSSIBLE EXCEPTION OF KHUF.
EITHER CASE CEILINGS SHOULD IMPROVE TO 25 HND TO 3 THOUSAND BY 22Z
AS SOME LOW LEVEL HEATING OCCURS.
AFTER THE IMPROVEMENT LATE TODAY...ATTENTION SHIFTS TO UPPER TROUGH
OVER THE CENTRAL PLAINS WHICH WILL MOVE OUR WAY LATE TONIGHT. THIS
SYSTEM WILL BRING LIGHT SNOW TO MOST SITES BEGINNING AROUND 08Z AND
POSSIBLE MIXED RAIN/SNOW AT KBMG. THIS WILL CAUSE A LOWERING OF
FLIGHT CONDITIONS WITH SOME AREAS BECOMING IFR. MUCH OF THIS WILL
MOVE OUT BY 15Z AND MVFR CEILINGS WILL BE THE RULE AND SOME SITES
MAY BECOME VFR AFTER 18Z WEDNESDAY. WINDS WILL BE 6 KNOTS OR LESS
THE REST OF TODAY AND TONIGHT AND NORTH 8 TO 10 KNOTS ON WEDNESDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....JH
AVIATION...JH/JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
255 PM EST TUE FEB 7 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...AN UPPER DISTURBANCE WILL MOVE THROUGH CENTRAL INDIANA OVERNIGHT AND
EARLY WEDNESDAY MORNING BRINGING MEASURABLE SNOW TO MUCH OF THE AREA
FOR THE MORNING COMMUTE. BY WEDNESDAY AFTERNOON HIGH PRESSURE
RIDGING WILL BUILD INTO THE AREA AND BRING DRY WEATHER UNTIL THE
NEXT WAVE ARRIVES ON FRIDAY WITH MORE CHANCES FOR SNOW THROUGH
FRIDAY NIGHT. AFTER THAT THE WEATHER WILL BE QUIET UNTIL THE NEXT
WAVE APPROACHES FOR MONDAY NIGHT.
&&
.NEAR TERM /TONIGHT INTO WEDNESDAY MORNING/...
FORECAST FOCUS IS ON POPS/TIMING/SNOWFALL AMOUNTS WITH RESPECT TO UPPER
WAVE MOVING THROUGH OVERNIGHT. CONFIDENCE IN ACCUMULATING SNOWFALL
OCCURRING OVER MUCH OF CENTRAL INDIANA HAS INCREASED WITH LATEST
MODEL RUNS AS UPPER FORCING SHOWN OVER LAST FEW DAYS IS STILL THERE
BUT IS NOW JOINED BY VERY WEAK FRONTOGENESIS...INCREASED DEEP LAYER
MOISTURE...AND A BIT OF INSTABILITY. GFS/NAM/SREFS/ECMWF ALL IN
AGREEMENT ON THIS WAVE AND SOME MEASURABLE QPF AS WELL. THIS WAVE
WILL COME TOGETHER AND MOVE ACROSS SOUTHERN INDIANA DURING THE
OVERNIGHT HOURS INTO THE MORNING. CONSENSUS OF TIMING SHOWS BEST
FORCING OVER THE AREA BETWEEN 9 AND 15Z SO CONFINED HIGHEST POPS TO
THAT TIME WITH LOW CHANCES IN THE NORTHEAST INCREASING TO LIKELIES
ALONG I70 AND SOUTH AND FINALLY CATEGORICAL SNOW IN THE FAR SOUTH.
PRIOR TO THIS WILL SLOWLY RAMP POPS UP WITH ONLY SLIGHT CHANCE PRIOR
TO 6Z AND THEN CHANCES SPREADING NORTHEAST OVER THE AREA FROM 6-9Z.
AS FAR AS PRECIPITATION TYPE IS CONCERNED...MOST MODEL FIELDS ARE
INDICATING ALL SNOW FOR THE ENTIRE AREA...BUT NAM THICKNESSES START
OUT MARGINAL AND RUC SOUNDINGS SHOW POTENTIAL FOR A RAIN SNOW MIX
EARLY IN THE SOUTH. THEREFORE WILL CARRY LOW CHANCES FOR A RAIN SNOW
MIX IN THE SOUTHERN TWO TIERS THROUGH 6Z AND ALL SNOW THEREAFTER.
AS FAR AS AMOUNTS ARE CONCERNED...WITH THE BEST FORCING IN THE SOUTH
WILL GO WITH HIGHEST AMOUNTS THERE. GENERALLY AROUND AN INCH TOTAL
IN THE SOUTH WITH LOCALLY HIGHER AMOUNTS POSSIBLE...HALF AN INCH TO
AN INCH CENTRAL...AND ONLY AROUND A TENTH OF AN INCH IN THE
NORTHWEST IF ANY ACCUMULATION AT ALL AS IT IS FURTHEST FROM THE
FORCING. WHILE HIGHEST AMOUNTS ARE ONLY AROUND AN INCH THE TIMING
WILL BE PROBLEMATIC AS SNOW WILL BEGIN IN THE WEE HOURS OF THE
MORNING AND CONTINUE THROUGH MID MORNING...IMPACTING THE MORNING
COMMUTE. WILL ISSUE AN SPS TO HIGHLIGHT THE TIMING FACTOR.
FOR LOW TEMPERATURES GUIDANCE WAS IN GOOD AGREEMENT SO USED AN
AVERAGE IN THE MID 20S TO LOW 30S.
&&
.SHORT TERM /WEDNESDAY AFTERNOON THROUGH FRIDAY/...
MODELS ARE IN GOOD AGREEMENT SO WILL USE A CONSENSUS APPROACH. THE
UPPER WAVE IS THROUGH THE AREA BY WEDNESDAY AFTERNOON WITH UPPER
RIDGING MOVING INTO THE AREA. THIS WILL KEEP THINGS DRY UNTIL FRIDAY
WHEN ANOTHER WAVE APPROACHES AND BRINGS LOW CHANCES FOR SNOW. FOR
TEMPERATURES GENERALLY WENT NEAR A GUIDANCE AVERAGE...BUT USED
TEMPERATURES COOLER THAN GUIDANCE FOR WEDNESDAY AND FRIDAY HIGHS
WITH COLD ADVECTION AND EXPECTED CLOUD COVER. THIS YIELDED
TEMPERATURES NEAR AVERAGE FOR THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE BEST CHANCES OF PRECIP WILL BE DURING THE FRIDAY NIGHT PERIOD AS
A STRONG UPPER TROUGH ROTATES EAST ACROSS THE GREAT LAKES AND AGAIN
TOWARDS MONDAY NIGHT WARM ADVECTION INCREASES AND A WEAK UPPER LEVEL
DISTURBANCE MOVES THROUGH THE OHIO VALLEY.
WENT PRETTY MUCH TO ALL BLEND POPS FRIDAY NIGHT. BUT IN THE NORTH I
INCREASED THEM A LITTLE AS THERE COULD BE SOME LAKE ENHANCEMENT.
THIS LAKE ENHANCEMENT MAY LINGER INTO SATURDAY SO KEPT SLIGHT
CHANCES ACROSS MUCH OF OUR FAR NORTH. MODELS HAVE TRENDED COLDER
OVER THE WEEKEND AND WENT CLOSER TO THE CONSALL NUMBERS AS THE COLD
UPPER TROUGH MOVES ACROSS THE GREAT LAKES OVER THE WEEKEND.
HIGH PRESSURE WILL MOVE ACROSS OUR REGION SUNDAY AND WARM ADVECTION
STARTS MONDAY. MODELS HAVE TRENDED SLOWER...SO WILL ONLY MENTION
SLIGHT CHANCE OF PRECIP ACROSS OUR FAR SOUTHWEST LATE MONDAY.
MOST MODELS PRODUCE LIGHT PRECIP AMOUNTS AND THICKNESS SHOULD BE LOW
ENOUGH FOR MOSTLY SNOW NORTH AND CENTRAL MONDAY NIGHT. RAISED
TEMPERATURES A LITTLE WITH CLOUDS AND WARM ADVECTION MONDAY NIGHT.
ALL BLEND TEMPERATURES MAY BE A TAD WARM TUESDAY AS THERE WILL BE
LOTS OF CLOUDS. BUT ONLY CHANGE I MADE WAS TO LOWER THE NORTH HALF
A FEW DEGREES IN CASE THERE WAS SOME LEFT OVER SNOWFALL FROM MONDAY
NIGHT.
&&
.AVIATION /DISCUSSION FOR 071800Z TAF ISSUANCE/...
MVFR CEILINGS WITH STRATUS WERE THE RULE OVER MUCH OF THE REGION AT
MIDDAY. THERE ARE SOME SIGNS KBMG MAY BEGINNING TO BREAK OUT OF THE
STRATUS AS THE THE SOUTHERN PORTIONS BEGINS ERODING. OTHER SITES
COULD SCATTER OUT BY LATE AFTERNOON. BUT MODEL SOUNDINGS STILL SHOW
A SOMEWHAT MOIST LAYER RIGHT UNDER A LOW LEVEL INVERSION. SO FOR NOW
WILL KEEP MOST OTHER AREAS BROKEN WITH POSSIBLE EXCEPTION OF KHUF.
EITHER CASE CEILINGS SHOULD IMPROVE TO 25 HND TO 3 THOUSAND BY 22Z
AS SOME LOW LEVEL HEATING OCCURS.
AFTER THE IMPROVEMENT LATE TODAY...ATTENTION SHIFTS TO UPPER TROUGH
OVER THE CENTRAL PLAINS WHICH WILL MOVE OUR WAY LATE TONIGHT. THIS
SYSTEM WILL BRING LIGHT SNOW TO MOST SITES BEGINNING AROUND 08Z AND
POSSIBLE MIXED RAIN/SNOW AT KBMG. THIS WILL CAUSE A LOWERING OF
FLIGHT CONDITIONS WITH SOME AREAS BECOMING IFR. MUCH OF THIS WILL
MOVE OUT BY 15Z AND MVFR CEILINGS WILL BE THE RULE AND SOME SITES
MAY BECOME VFR AFTER 18Z WEDNESDAY. WINDS WILL BE 6 KNOTS OR LESS
THE REST OF TODAY AND TONIGHT AND NORTH 8 TO 10 KNOTS ON WEDNESDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....JH
AVIATION...JH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1146 AM CST TUE FEB 7 2012
.UPDATE...
MORNING UPDATE LOWERED POPS OUT OF LIKELY CATEGORY SOUTH.
OPERATIONAL MODELS...HRRR AND ARM-NMM WRF RUNS ALL SUGGEST KEEPING
MEASURABLE PRECIP INTO MO. LATEST RUC SOUNDINGS INDICATE 1-3KM DRY
LAYER SOUTH MAKING THOSE ECHOES SEEM WORSE THAT WHAT IS
OCCURRING...AND EXPECT KS/MO PRECIP UPSTREAM TO SWING TO THE SOUTH.
LOW LEVEL COLD ADVECTION SHOULD ALSO KEEP TEMPS STEADY OR SLOWLY
FALLING INTO THE AFTERNOON.
ALSO UPDATED 18Z TAF DISCUSSION.
&&
.SHORT TERM /TODAY/...
TWO UPPER LEVEL SYSTEMS CONVERGING ON THE AREA TODAY...WITH THE
FIRST CURRENTLY MOVING EAST THROUGH THE CENTRAL PLAINS OF NE/KS AND
THE SECOND SYSTEM DROPPING SOUTHWARD THROUGH THE DAKOTAS/MINNESOTA.
COLD FRONT ASSOCIATED WITH THE NORTHERN SYSTEM ALSO MAKING ITS WAY
INTO THE NORTHWESTERN PORTION OF THE CWA...AND WILL CONTINUE TO
PROGRESS THROUGH ENTIRE CWA THROUGH THE MORNING HOURS. HAVE A DECK
OF LOW CLOUDS MOVING INTO AREAS BEHIND THE FRONT...AND ANOTHER DECK
OF HIGHER CLOUDS ASSOCIATED WITH THE WESTERN SYSTEM. ALREADY GETTING
SOME LIGHT PRECIP OUT OF THE HIGHER DECK OF CLOUDS...JUST NOT
REACHING THE GROUND. HOWEVER ONCE START TO GET THE BETTER SATURATION
IN THE LOWER LEVELS BEHIND THE FRONT...COULD START TO GET SOME
SEEDER FEEDER ACTION WITH WEAK LIFT OVER THE AREA THIS MORNING WHICH
COULD LEAD TO SOME SCATTERED FLURRIES/LIGHT SNOW. OTHERWISE DRY
LAYER BETWEEN THE TWO CLOUD DECKS COULD BE TOO DEEP WHICH WOULD NOT
ALLOW ICE CRYSTAL INTRODUCTION TO THE LOWER DECK WHICH COULD LEAD TO
MORE OF A PATCHY FZDZ SITUATION. HOWEVER WITH TEMPERATURES ALOFT
COOLING QUITE RAPIDLY BEHIND THE FRONT...EXPECT ANY FZDZ TO BE
RELATIVELY SHORT-LIVED BEFORE ANY LIGHT PRECIPITATION MAKING IT TO
THE GROUND WOULD CHANGE OVER TO SNOW. ALSO HAVE SOME STRONGER ARES
OF LIFT WITH DEEPER SATURATION PUSHING INTO THE SOUTHWEST TO SOUTH
CENTRAL COUNTIES TOWARD THE LATE MORNING/EARLY AFTERNOON HOURS.
THEREFORE HAVE SOME CHANCE TO LOW LIKELY POPS FOR THAT AREA FOR SOME
LIGHT SNOW. TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE
FREEZING...SO NOT EXPECTING MUCH ACCUMULATION WITH THIS SITUATION
BEING A RELATIVELY LOW QPF/HIGH POP EVENT.
.LONG TERM /TONIGHT THROUGH MONDAY/...
SYSTEM PASSING THROUGH STATE TODAY WILL MOVE RAPIDLY EAST TONIGHT
WITH SOME LINGERING FLURRIES IN THE SOUTH DURING THE EVENING.
OTHERWISE...SUBSIDENCE WILL INCREASE OVERNIGHT AS SURFACE RIDGING
BUILDS INTO THE PLAINS AND THE ASSOCIATED DRYING WILL ALLOW CLOUDS
TO DECREASE FROM NORTH TO SOUTH DURING THE NIGHT. THE REST OF THE
FORECAST THROUGH THE WEEKEND IS ONE WITH LITTLE THREAT OF
PRECIPITATION AS MOISTURE AND BEST FORCING WILL RESIDE ELSEWHERE BUT
GENERALLY NOT OVER IOWA. MAIN ISSUES WILL FOCUS ON TEMPERATURE
CHANGES AS THE THERMAL PROFILE CHANGES DURING THE WEEK. READINGS
LIKELY SIMILAR ON WEDNESDAY WHEN COMPARED TO TODAY AS SIMILAR
AIRMASS REMAINS OVER THE STATE. HOWEVER...SOME MODERATION IS
EXPECTED INTO THURSDAY AS A WEAK THERMAL RIDGE SLIDES INTO THE STATE
AND HAVE WARMED READINGS ABOVE GUIDANCE IN LOCATIONS NOT INFLUENCED
BY THE CURRENT SNOWPACK. HOWEVER...A MUCH STRONGER PUSH OF POLAR
AIR IS SET TO ARRIVE ON FRIDAY AND PERSIST INTO SATURDAY ACROSS THE
STATE. MEDIUM RANGE GUIDANCE HAS FINALLY CAUGHT ONTO THIS COOLER
AIR WITH OUTPUT NOT AS WARM AS PREVIOUS RUNS. HAVE CONTINUED TO
KEEP HIGHS AND LOWS COOLER OF THE SNOW PACK DURING THIS TIME WITH
READINGS HARD PRESSED TO GET OUT OF THE 20S ON FRIDAY OR SATURDAY.
SOME MODERATION IS THEN EXPECTED ON SUNDAY INTO MONDAY AS SOUTHERLY
FLOW INCREASES. THERE IS AN OUTSIDE CHANCE OF SOME SNOWFALL EARLY
IN THE WEEK BUT TIMING OF THE SYSTEM IS SOMEWHAT VAGUE THIS FAR
OUT. HAVE LEFT IN SLIGHT CHANCES ON MONDAY WHICH TENDS TO REFLECT
THE LOW CONFIDENCE AT THIS POINT OF SEEING MUCH PRECIPITATION AT
THIS TIME.
&&
.AVIATION...07/18Z
IFR STRATUS CONTINUES TO AFFECT SE IA WITH WIDESPREAD MVFR
CONDITIONS UPSTREAM ACROSS IA INTO MN AND WI. MODELS INDICATE VERY
GRADUAL IMPROVEMENT NORTH-SOUTH BECOMING VFR 01Z-09Z. OCCASIONAL
FLURRIES OR LIGHT SNOW MAY AFFECT SITES OUTSIDE OF KMCW BUT ANY VSBY
RESTRICTIONS WOULD PRIMARILY BE TO FOG RATHER THAN SNOW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE/AVIATION...SMALL
SHORT TERM...BEERENDS
LONG TERM...COGIL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1215 PM CST TUE FEB 7 2012
.UPDATE...
ISSUED AT 1210 PM CST TUE FEB 7 2012
SNOW CONTINUES TO TAPER OFF WEST AND NORTH OF DODGE CITY. HAVE
THEREFORE REMOVED SEVERAL MORE COUNTIES FROM THE WINTER WEATHER
ADVISORY. THE NEW RUC40 AND HRRR CONTINUES TO KEEP THE BETTER
FORCING SOUTH AND SOUTHEAST OF DODGE FOR THE NEXT FEW HOURS BUT
EVEN HERE THE TREND WILL BE A DECREASING TREND BASED ON THE
MOVEMENT OF THE MID LEVEL BAROCLINIC ZONE AND 300MB JET. ADDITION
SNOWFALL IN THE ADVISORY AREA IS EXPECTED TO AVERAGE ONE INCH OR
LESS BETWEEN NOON AND 4 PM. GUSTY WINDS COMBINED WITH THIS
EXPECTED SNOWFALL WILL CONTINUE TO REDUCE VISIBILITIES DUE TO
BLOWING/DRIFTING SNOW.
UPDATE ISSUED AT 1006 AM CST TUE FEB 7 2012
AREA MOST FAVORABLE FOR SNOW TO CONTINUE THROUGH THE EARLY
AFTERNOON WILL BE EAST OF MEADE TO DODGE CITY TO NEAR NESS CITY
LINE GIVEN THE LOCATION OF THE LEFT EXIT REGION OF THE 300MB JET
AT 12Z AND MOISTURE AT 850-700MB AHEAD OF THE 700MB BAROCLINIC
ZONE. SNOW AMOUNTS STILL APPEAR TO BE ON TRACK WITH GENERAL
AMOUNTS OF AROUND 2 INCHES IN THE ADVISORY AREA AND A FEW LOCALLY
HIGHER AMOUNTS POSSIBLE. AS A RESULT WILL CONTINUE THE WINTER
WEATHER ADVISORY IN THESE AREAS. FURTHER WEST CANCELED THE WINTER
WEATHER ADVISORY ALTHOUGH A FEW FLURRIES WILL STILL BE POSSIBLE
FOR THE NEXT COUPLE OF HOURS.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 337 AM CST TUE FEB 7 2012
WATER VAPOR IMAGERY IS SHOWING THAT THE UPPER LOW THAT WAS SPINNING
OVER WESTERN COLORADO 24 HOURS AGO HAD OPENED UP AND WAS OVER THE
EASTERN PLAINS OF COLORADO EARLY THIS MORNING. THE UPPER AIR
ANALYSIS SHOWED AN 80 KNOT JET MAX OVER CENTRAL NEW MEXICO. CLOUD
TOPS WERE COOLING OVER FAR WESTERN KANSAS AS THE UPPER LEVEL
FORCING APPROACHED THE AREA. A COLD FRONT WAS ALSO MOVING SOUTH
ACROSS THE HIGH PLAINS AND WAS THROUGH FAR SOUTHWEST KANSAS AND
POISED TO MOVE THROUGH SOUTH CENTRAL KANSAS EARLY THIS MORNING.
THE RADAR MOSAIC WAS SHOWING AREAS OF LIGHT SNOW CONTINUING TO
DEVELOP AND EXPAND ACROSS THE REGION.
THE GOING FORECAST FOR THE DEVELOPING WINTER WEATHER SEEMS TO BE
ON TRACK AND ONLY REQUIRED SOME MINOR TWEAKS. THE 00Z MODEL RUNS
WERE IN PRETTY GOOD AGREEMENT WITH THE UPPER FEATURES. MODEL QPF
AND SNOW FORECAST AMOUNTS ARE POINTING AT GENERAL 1 TO 3 INCH
SNOWFALL ACCUMULATIONS WITH SOME LOCALLY HEAVIER AMOUNTS OF 4-5
INCHES POSSIBLE. HARD TO TELL EXACTLY HOW MUCH WILL FALL GIVEN THE
PROGRESSIVE NATURE OF THIS SYSTEM. THE MODELS SHOW THE BULK OF THE
UPWARD VERTICAL MOTION OCCURRING DURING THE 12Z-18Z TIMEFRAME AND
TIME SECTIONS SHOW THE UPWARD MOTION FOCUSED IN THE DENDRITIC
GROWTH LAYER. GIVEN THE COLD AIRMASS ACCOMPANYING THIS SYSTEM,
LIQUID/SNOW RATIOS SHOULD BE HIGHER THAN 10:1 AS WELL AND POSSIBLY
CLOSER TO 15:1. HAVE BUMPED UP POPS AND SNOWFALL ACCUMULATIONS
JUST A BIT ESPECIALLY IN THE AREA WHERE THE CURRENT WINTER WEATHER
ADVISORY IS IN EFFECT. WINDS ARE ALREADY STARTING TO PICK UP
BEHIND THE FRONT SO SOME BLOWING AND DRIFTING SNOW CAN ALSO BE
EXPECTED. THE SNOW SHOULD BE TAPERING OFF RAPIDLY FROM WEST TO
EAST ACROSS SOUTHWEST AND SOUTH CENTRAL KANSAS FROM LATE MORNING
THROUGH MID AFTERNOON AND SHOULD BE EAST OF THE AREA BY SUNSET.
HIGH PRESSURE BUILDING SOUTH OUT OF CANADA TODAY WILL BE MOVING
DOWN OVER KANSAS TONIGHT SO EXPECT SKIES TO BE CLEARING ACROSS ALL
THE AREA BY THIS EVENING WITH LIGHT WINDS BY TUESDAY MORNING. MOS
GUIDANCE HAS TEMPERATURES INTO THE UPPER SINGLE DIGITS AND LOWER
TEENS OVER MOST OF THE AREA AND HAVE UNDERCUT BY A FEW DEGREES IN
PLACES. LOWS MAY WIND UP BEING EVEN COLDER.
WEDNESDAY SHOULD BE MOSTLY SUNNY BUT TEMPERATURES WILL NOT LIKELY
RISE MUCH ABOVE FREEZING GIVEN THE COLD START TO THE DAY AND SOME
LINGERING SNOW COVER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 337 AM CST TUE FEB 7 2012
FAIRLY TRANQUIL WEATHER CAN BE EXPECTED THURSDAY AND FRIDAY IN THE
WAKE OF THE UPPER-LEVEL SYSTEM THAT WILL PASS TUESDAY. THE MAIN
FORECAST CHALLENGE IS THE AMOUNT OF SNOW COVER AND ITS EFFECT ON
TEMPERATURES. GIVEN THAT VERY COLD TEMPERATURES ARE EXPECTED TUESDAY
NIGHT WITH CLEAR SKIES AND SNOW COVER, THE SNOW WILL BE SLOW TO MELT
WEDNESDAY GIVEN THE FROZEN GROUND. THEREFORE, IT SEEMS REASONABLE TO
EXPECT THAT SOME SNOW COVER WILL LINGER IN PLACES INTO THURSDAY,
ESPECIALLY FROM DODGE CITY SOUTHWARD. THEREFORE, MAXIMUM
TEMPERATURES WERE LOWERED A FEW DEGREES IN THIS AREA FOR THURSDAY.
A POLAR VORTEX WILL BE SWINGING SOUTHEASTWARD OUT OF CANADA INTO THE
GREAT LAKES REGION BY THURSDAY NIGHT AND FRIDAY. THE BRUNT OF THE
COLD AIR WITH THIS SYSTEM WILL STAY WELL TO OUR NORTHEAST. BUT THIS
GLANCING SHOT OF COOLER AIR SHOULD PREVENT ANY MAJOR WARMUP EVEN
AFTER THE SNOW MELTS (ASSUMING IT DOES MELT BY THEN).
THE NEXT MAJOR FORECAST CHALLENGE IS THE AMPLITUDE AND TIMING OF THE
NEXT UPPER-LEVEL TROUGH OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
DESPITE THE MODEL DIFFERENCES, THE COMMON THEME IS THAT SOMETIME
DURING THIS PERIOD THERE WILL BE A WARM ADVECTION PATTERN DEVELOPING
IN THE WAKE OF A LOW-LEVEL COLD SURGE AS THE UPPER-LEVEL TROUGH
APPROACHES. THE CENTRAL REGION PRECIPITATION PROBABILITY GRIDS LOOK
REASONABLE, WITH 20-30% CHANCES BY SATURDAY NIGHT INTO SUNDAY NIGHT.
HOWEVER, MAXIMUM TEMPERATURES MAY BE COLDER FOR THE SUNDAY TO
TUESDAY TIME FRAME THAN WHAT IS CURRENTLY DEPICTED IN THE GRIDS,
ESPECIALLY IF WE DO RECEIVE SOME SNOW. ALSO, DIURNAL RANGES MAY BE
TOO LARGE GIVEN A CLOUDY REGIME. BUT GIVEN THE UNCERTAINTY, IT WAS
DECIDED UPON OFFICE COLLABORATION THAT THE CURRENT TREND OF COOLING
TEMPERATURES DOWN GRADUALLY WAS SUFFICIENT IN LIEU OF A SUDDEN,
MAJOR OVERHAUL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1115 AM CST TUE FEB 7 2012
AS AN UPPER LEVEL TROUGH AND MID LEVEL BAROCLINIC ZONE MOVES EAST
OF THE AREA EARLY THIS AFTERNOON THE MID LEVEL MOISTURE WILL
CONTINUE TO DECREASE. LOW LEVEL MOISTURE HOWEVER WILL PERSIST
BASED ON THE 12Z NAM BURF SOUNDINGS WHICH INDICATES THE LOW LEVEL
MOISTURE WILL LINGER THROUGH MUCH OF THE OVERNIGHT PERIOD. GFS
HOWEVER SUGGESTS LESS MOISTURE OVERNIGHT BUT GIVEN THE 17Z VISIBLE
SATELLITE IMAGE AND SURFACE OBSERVATONS ACROSS NORTHWEST KANSAS
AND EASTERN COLORADO AM CURRENTLY LEANING TOWARDS THE MORE
PESIMISTIC NAM IN KEEPING LOW IFR CLOUDS AROUND LONGER TONIGHT.
THE MIXED LAYER WINDS, WHICH DID A GOOD JOB WITH THE VERY WINDY
CONDITIONS EARLIER TODAY, DECREASE THROUGH THE REMAINDER OF THE
AFTERNOON AND BECOME LIGHT OVERNIGHT AS AN AREA OF HIGH PRESSURE
AT THE SURFACE BUILDS INTO CENTRAL AND WESTERN KANSAS. -RB
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 14 34 19 40 / 0 0 0 0
GCK 13 36 18 42 / 0 0 0 0
EHA 16 41 22 43 / 0 0 0 0
LBL 16 38 22 41 / 0 0 0 0
HYS 13 31 17 44 / 0 0 0 0
P28 21 35 22 43 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR KSZ064-
065-078>080-088-089.
&&
$$
UPDATE...18
SHORT TERM...02
LONG TERM....24
AVIATION...18
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1214 PM EST TUE FEB 07 2012
...Updated Aviation Discussion...
.Forecast Update...
Just making a few minor adjustments to the ongoing forecast, which
is pretty much on track. Low strato-cu will continue to spill
southeast into our far northern/northeastern counties. Don`t really
see this eroding on the southern edge as it did yesterday, so
although portions of s-central IN and n-central KY have sunny skies
now, we should see mostly cloudy skies by this afternoon. Just
beefed up cloud cover a bit in the grids, but overall temps/etc. on
track.
Upper disturbance approaching from the west won`t affect our CWA
until after midnight most likely. Will address that with afternoon
AFD.
Updated web forecast. No other changes made.
&&
.Short Term (Today - Wednesday)...
High pressure in place along with weak ridging aloft will keep
things dry today, although will have to deal with patchy
fog/freezing fog potential again through the morning hours. IR
satellite imagery currently shows a batch of low stratus across the
Great Lakes region to as far south as the I 74 corridor over central
and southern Indiana. HRRR has been consistent in showing these
clouds marching steadily southeast through the pre-dawn hours,
arriving near the Ohio River just after dawn. Therefore, skies
should clear in most spots with calm winds and subsident airmass.
This will lead to patchy fog formation, some of which will likely be
dense around dawn. Most likely areas will be in valleys and near
rivers and streams. With temperatures below freezing in most spots
will have to watch for slick spots. Will spend the rest of the
morning monitoring obs and issuing SPS or headline products if need
be. Right now, the only real indication of fog is over the Lake
Cumberland region.
Above mentioned status deck will likely scatter out over southern
Indiana this morning with upper level clouds beginning stream
overhead through the day. With low temperatures cooler than expected
this morning, have lowered highs a bit for this afternoon. Southern
Indiana will likely not make it out of the upper 40s with lower
level cloud cover this morning. Elsewhere, lower 50s can be expected
with mid 50s possible south.
The next weather making system will arrive after Midnight tonight as
an upper level impulse quickly ejects across the plains, absorbing
an upper low currently over NE Colorado. What may initially start
out as rain or a rain/snow mix across southern Indiana and central
Kentucky should quickly change over to snow as wet bulbing occurs
with low level saturation. Surface temperatures may stay just above
freezing in a few locations however warm layer at the surface will
be very shallow and should still support mostly snow. South of a
Bowling Green to Lake Cumberland line, precipitation type is more in
question and could end up being more rain and possibly a rain/snow
mix by dawn.
Best chances for precipitation, whether it be rain or snow, will be
from 3 AM EST to 8 AM EST early Wednesday. Will have to watch for a
moderate band of snow setting up anywhere from along and south of
the Ohio River to along and north of a Bowling Green to Lexington
line between 3 AM EST and dawn. This will occur just ahead of sharp
shortwave trough axis with frontogenesis coinciding with the left
exit region of an intensifying 100 to 120 knot upper level jet.
Models continue to indicate low amounts of QPF with this quick
hitting system, although have steadily increased amounts. Will have
to watch trends over the next 24 hours as banding does appear
possible with this setup and could produce a narrow swath of higher
QPF. That being said, ground and road temperatures should be well
above freezing with recent warm weather so do not expect any real
accumulation on these surfaces. Could see a dusting on grassy and
elevated surfaces by the daylight hours on Wednesday.
Upper level features quickly depart to the east by midday Wednesday,
however plentiful low level moisture between 1000-850 mb suggests
some flurries or sprinkles will be possible. Models are suggesting a
warm up to the low and mid 40s during the day however with overcast
skies expected, have a feeling temperatures will have trouble
getting out of the 30s. Therefore, will call for precipitation type
mostly in light snow or flurry category as any warm layer will be
confined to the surface and low level lapse rates will quickly
steepen. Could even see a few snow bursts through the day on
Wednesday as low levels edge toward a low degree of convective
instability. Again, expecting no real accumulations. Flurries or
sprinkles will linger through the day on Wednesday, along with
mostly cloudy skies.
.Long Term (Wednesday night - Monday)...
Wednesday night through Thursday night...
Main upper impulse will be exiting the area, but still expect some
residual low-level moisture to lingering Wednesday evening.
Subsidence and very shallow moist layer weigh against any precip so
no POPs in the forecast, but moisture and NW flow are sufficient
reason to hold onto a few early evening snow flurries in the eastern
tier.
Cold and dry high pressure on Thursday, with a broad, weak upper
trof overhead. MOS guidance is generally too warm in a shallow cold
air mass like this, so this forecast is more in line with the raw
model temps, with highs in the lower 40s in spite of full sunshine.
Clear and chilly Thursday night, but lows in the mid-upper 20s are
right in line with climo.
Friday through Monday...
Low-confidence forecast here as the models start to diverge. ECMWF
and GFS both drag some combination of a Clipper and/or cold front
across the Ohio Valley Friday night. ECMWF is trending more bullish
with southern-stream phasing and associated moisture. Will not jump
on this solution just yet but it bears watching. For now will go
with a slight chance for snow showers Fri night, mainly east of
I-65.
Cold high pressure plunges south from Canada for the weekend. Below
normal temperatures are a slam dunk but the question remains, how
much below normal? Coldest 850mb temps will be Saturday, when GFS
gets as cold as -14C. Current forecast max temps in the mid 30s may
be a bit too warm. Coldest night is Sat night, with lower 20s
across most locations. Not going for the quick rebound indicated by
extended GFS MOS on Sunday, given the cold start and model bias of
moving a high pressure ridge east too quickly. Expect highs in the
mid/upper 30s even with the thermal trof to our east.
Another southern stream system will affect the Ohio Valley early
next week, but model discrepancies are too large to jump on any one
solution just yet. Will keep Monday dry for now, as the quicker
ECMWF is also the less bullish model as far as QPF. Temps recover to
the high side of normal by Monday.
&&
.Aviation (18Z TAF Issuance)...
Over the next couple of hours, the main issue will be the strato-cu
clouds pushing south into northern KY, particularly affecting LEX.
Looks like these clouds are eroding somewhat, but will go ahead and
include a few hours of MVFR SCT-BKN clouds in at LEX and maybe SDF.
Otherwise, mid-high level clouds will push in from the west later
this afternoon as a weak upper disturbance over the Central Plains
arrives tonight. Light precipitation will increase from west to east
overnight, most likely affect BWG first by 06z, then SDF by 09z-ish,
and then LEX by approximately 11z. The more persistent precipitation
will arrive 2-3 hours after onset, with possibly MVFR CIGs and VSBYs
occurring along with it.
Moisture moves out of the area rapidly, and think by the end of this
TAF period, BWG will be drying out, and possibly SDF by then, too.
For precip type, looks like onset may be just -SN, but a -RASN mix
is possible at BWG, too. Light snow will be the dominate type at SDF
and LEX, and will push back the onset 1-2 hours at these locations
in the TAFs. Otherwise no real big changes. For winds, expect
north-northwest winds over the area throughout the TAF period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Update...........AL
Short Term.......BJS
Long Term........RAS
Aviation.........AL
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1227 PM EST TUE FEB 7 2012
.SYNOPSIS...
A SHALLOW COLD FRONT WILL SPREAD LOW CLOUDS ACROSS THE UPPER OHIO
VALLEY AND SOUTH OF THE MASON DIXON LINE THIS AFTERNOON. LOW PRESSURE WILL
MOVE EASTWARD ALONG THE STALLED FRONT WEDNESDAY, AND BRING SNOW
SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LITTLE CHANGE TO PREVIOUS FORECAST FOR EARLY AFTERNOON UPDATE WITH
ONLY A FEW CHANGES TO SKY GRIDS. RAISED MAX TEMPS A DEGREE OR TWO
BASED ON NOON READINGS. WEAK AND HARD TO FIND BOUNDARY SAGGING
SOUTH AND WILL STALL AS SHORTWAVE APPROACHES FROM THE SOUTHWEST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
SHORTWAVE IN THE SOUTHERN STREAM OF CONFLUENT FLOW PROJECTED OVER
THE REGION IS PROGGED TO GENERATE SNOW SHOWERS ALONG THE SOUTHWARD
SAGGING, AFOREMENTIONED COLD FRONT LATE TUESDAY NIGHT/WEDNESDAY.
CHANCE PRECIP PROBABILITIES WERE INCLUDED FOR THIS SCENARIO, BUT
WITH BETTER NUMBERS OVER SOUTHERN ZONES DUE TO EXPECTED PROGRESS
OF THE FRONT. LIKELY NUMBERS THAT WERE FORECAST FOR THE RIDGES ARE
DUE TO EXTRA SUPPORT VIA DEVELOPING UPSLOPE.
OVERALL, LIGHT SNOW ACCUMULATION IS POSSIBLE ON WEDNESDAY WITH
AMOUNTS LIMITED BY THE PROGRESSIVE NATURE OF THE SYSTEM AND
SURFACE TEMPERATURES ABOVE FREEZING.
TEMPERATURES WERE FORECAST NEAR NORMAL USING A BLEND OF GUIDANCE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LATEST ECMWF AND GFS MODEL OUTPUT SHOWS A DEEP UPPER TROUGH SWINGING
THROUGH EASTERN CANADA BY THE WEEKEND. TIMING OF THE ASSOCIATED
COLD FRONT STILL VARIES SOMEWHAT BETWEEN GFS/ECMWF, BUT LATEST
THINKING IS THAT THE FRONT WILL PUSH ACROSS THE FORECAST AREA LATE
FRIDAY, BRINGING SCATTERED SNOW SHOWERS, POSSIBLY MIXING WITH RAIN
SHOWERS IN THE SOUTH, AND A RETURN TO MORE WINTER-LIKE TEMPERATURES.
SURFACE HIGH PRESSURE AND DRIER AIR ARE PROJECTED TO MOVE OVER
THE OHIO VALLEY ON SUNDAY AND MONDAY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
PER BLEND OF RECENT SURFACE AND SATELLITE DATA, NAM AND HRRR MODEL
OUTPUT, AND GFS LAMP, EXPECT SHALLOW COLD FRONTAL BAND OF
STRATOCUMULUS, SPREADING SOUTHWARD AT 15 KTS, TO GET AS FAR SOUTH
AS THE MASON-DIXON LINE BY 16Z, BEFORE STOPPING. CEILINGS WILL BE
MAINLY AT MVFR LEVELS, BUT BRIEF IFR INTERLUDES CANNOT BE RULED
OUT THIS MORNING. HAVE LOW CONFIDENCE THAT THE CLOUDS REACH KMGW.
TERMINALS SUCH AS KZZV, KHLG, AND KLBE MAY SEE CLOUD COVERAGE GO
SCATTERED FOR A TIME THIS AFTERNOON.
IN GENERAL, EXPECT MVFR CEILINGS TONIGHT, EVEN AT KMGW LATE
TONIGHT, AS LOW PRESSURE APPROACHES FROM THE WEST.
SURFACE WINDS WILL GO TO NORTH-NORTHWEST NEAR 10 KTS BY MIDDAY.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
AN EASTBOUND LOW PRESSURE SYSTEM WILL DEEPEN THE COLD FRONT TO YIELD
MVFR SNOW SHOWERS BY DAYTIME WEDNESDAY. ENSUING HIGH PRESSURE WILL
PROVIDE VFR THURSDAY AND FRIDAY. A COLD FRONTAL BAND OF SNOW
SHOWERS WILL PROVIDE RESTRICTIONS SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
133 PM EST TUE FEB 7 2012
.UPDATE...
ISSUED AT 133 PM EST TUE FEB 7 2012
LAKE EFFECT SNOW SHOWERS CONTINUE TO DIMINISH RAPIDLY AS DRY AIR
CONTINUES TO MOVE INTO THE AREA AND ANTICYCLONIC FLOW AND LACK OF
LOW LEVEL CONVERGENCE ALSO HELPS TO ERODE THE CLOUDS AND LAKE EFFECT
SNOW SHOWERS. CUT POPS BACK AND DECREASED CLOUD COVER.
&&
.SYNOPSIS...
ISSUED AT 427 AM EST TUE FEB 7 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW RATHER SHEARED
POSITIVELY TILTED SHRTWV DROPPING SEWD THRU THE UPR LKS IN
PREVAILING NW FLOW ALF BTWN TROF OVER QUEBEC AND UPR RDG OVER WRN
CAN. ACCOMPANYING SHARP COLD FNT THAT SURGED THRU THE FA YDAY HAS
NOW PUSHED TO THE S. ALTHOUGH MUCH COLDER AIR IS FOLLOWING THE FNT
WITH NNE FLOW AND 00Z H85 TEMPS RANGING FM 0C AT GRB TO -10C AT INL
AND -17C AT YPL...SGNFT LES HAS NOT DEVELOPED EVEN IN AREAS FAVORED
BY THE NNE FLOW. KEY FACTORS APPEAR TO BE IMPRESSIVE DRYING
REFLECTED BY 00Z YPL RAOB /00Z PWAT 0.06 INCH/ THAT IS STEADILY
ERODING THE BACK EDGE OF THE LK CLD AS SHOWN ON IR STLT IMAGERY...
SUBSIDENCE ASSOCIATED WITH FAIRLY VIGOROUS DNVA/CAD/DEEP LYR QVECTOR
DVGC IN THE WAKE OF THE SHRTWV THAT IS CAUSING THE LLVL FLOW TO
BECOME ACYC AND SINK INVRN BASE TO ARND H9 AS SHOWN ON THE 00Z INL
AND YPL RAOBS. UNDER SFC RDG AXIS IN ONTARIO EXTENDING E FM HI
CENTER NEAR LK WINNIPEG...SKIES ARE MOCLR...AND SFC TEMPS/DWPTS HAVE
FALLEN INTO THE ZERO TO -10F RANGE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EST TUE FEB 7 2012
TODAY...COLD NLY FLOW IS FCST TO PERSIST THRU THIS MRNG BEFORE HI
PRES CENTER BLDG FM LK WINNIPEG INTO MN CAUSES THE LLVL FLOW TO BACK
TO THE W BY LATE IN THE DAY. THE COLDEST MODELS...NOTABLY THE 00Z
CNDN AND LOW WRF-ARW...SHOW H85 TEMPS SINKING TO -15 TO -17C OVER
SCNTRL LK SUP THIS MRNG WHILE THE WARMER 00Z NAM/GFS INDICATE THESE
TEMPS WL FALL NO LOWER THAN -14C OR SO. THE DIFFERENCE APPEARS TO BE
RELATED TO THE INVRN HGT FCST...WITH THE WARMER MODELS INDICATING A
LOWER INVRN BASE AOB 3K FT /NAM/ AS COMPARED TO ARND 4K FT
/WRF-ARW/. SINCE DEEP LYR QVECTOR DVGC/SUBSIDENCE WL INTENSIFY THRU
THE DAY AND TRENDS ON OBSVD SKY COVER OVER LK SUP SUG THE INVRN IS
CRASHING...WL TEND TO FOLLOW THE WARMER/LO INVRN BASE DEPICTED BY
THE 00Z NAM. THIS MODEL SHOWS ALMOST NO PCPN EVEN IN THE N WIND SN
BELTS WITH DIFFLUENT FLOW/H925-85 DEWPT DEPRESSION AS HI AS 7-10C
EVEN OVER THE N WIND SN BELTS THAT WOULD OTRW BE FAVORED BY THE LLVL
FLOW. SO ALTHOUGH SOME LES IS LIKELY TO BREAK OUT IN THE NEXT FEW
HRS THRU 12Z WITH THE ARRIVAL OF COLDER AIR...ANY SN ACCUM SHOULD BE
NO MORE THAN ARND AN INCH EVEN OVER THE HIER TERRAIN. BACKING MORE
ACYC FLOW THIS AFTN WITH INVRN BASE REMAINING BLO 3K FT SHOULD
DIMINISH THE LES FURTHER. ALTHOUGH DAYTIME TEMPS WL BE JUST A BIT
BELOW NORMAL...RECENT WARMTH WL MAKE THE DAY FEEL EVEN COLDER...
ESPECIALLY THIS MRNG WITH A STEADY N WIND.
TNGT...SFC HI PRES RDG AXIS IS FCST TO BE NEARLY OVHD IN THE EVNG
BUT THEN SHIFT TO THE S. WITH CONTINUED SUBSIDENCE AND THE FLOW
BACKING TO THE W...EXPECT SKIES TO TURN MOCLR EXCEPT PERHAPS OVER
THE KEWEENAW AND NEAR LK SUP E OF MUNISING. PWAT IS FCST TO BE 0.10
INCH AT 00Z...SO EXPECT A QUICK FALL OF TEMP IN THE EVNG WITH LGT
WINDS...SO ACCELERATED EARLY FALL OF TEMP. ONCE THE RDG SHIFTS TO
THE S OVERNGT...A STRONGER WNW WIND WL DVLP...WITH H925 WINDS FCST
UP TO 30-35 KTS. RETAINED GOING FCST MIN TEMPS AOB THE LO END OF
GUIDANCE PER VERY DRY AIR/OBSVD CHILL UPSTREAM OVER THE MORE
SHELTERED SRN TIER. TEMPS WL BE QUITE A BIT WARMER NEAR THE MORE
EXPOSED LK SUP AND UNDER THE SHARPER PRES GRADIENT FARTHER N OF THE
RDG AXIS...ESPECIALLY OVER THE E WHERE SOME LO CLDS MAY LINGER NEAR
THE SHORE THRU THE NGT UNDER WNW H925 FLOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 427 AM EST TUE FEB 7 2012
TROUGH WILL BE EXITING INTO EASTERN CANADA TO START THE LONG TERM
WHICH ALLOWS FOR HEIGHTS TO RISE FM PLAINS INTO GREAT LAKES. AT THE
SFC...HIGH PRESSURE OVER THE PLAINS SLIDES SOUTH ON WEDNESDAY
ALLOWING FOR WESTERLY WINDS AT LOW-LEVELS OVR UPR LAKES INTO
WEDNESDAY NIGHT. WEST WINDS ALONG WITH JUST SCT MID CLOUDS RESULTED
IN RAISING MAX TEMPS TOWARD HIGHER END OF GUIDANCE /AROUND 30 INLAND
AND INTO THE MID 30S NEAR LK SUPERIOR/. NEXT COLD FRONT WILL BE
DROPPING SOUTH ACROSS ONTARIO ON WEDNESDAY NIGHT...SO EXPECT AT
LEAST LGT WEST WINDS TO PERSIST THROUGH THE NIGHT. INLAND AREAS
COULD TRY TO DECOUPLE AND FALL INTO THE TEENS...BUT TEMPS ALONG
SHORELINES OF LK SUPERIOR AND LK MICHIGAN SHOULD STAY IN THE MID TO
UPR 20S. FCST SOUNDINGS FM BOTH NAM AND GFS INDICATE CONDITIONS TOO
DRY TO SUPPORT ANY PCPN AHEAD OF THE FRONT IN THE WESTERLY FLOW.
HAVE REMOVED ANY MENTION OF SNOW UNTIL THURSDAY...EVEN OVR THE
KEWEENAW PENINSULA.
CHANGES BEGIN TO OCCUR LATER THURSDAY AS ARCTIC COLD FRONT IS FCST
TO ARRIVE. PROBABLY WILL SEE FALLING TEMPS...BUT AT THIS POINT STUCK
WITH NORMAL DIURNAL TEMP CURVE AS PRIMARY COOLING FM FROPA DOES NOT
OCCUR UNTIL LATE IN THE DAY. SOUNDINGS SHOW SUFFICIENT MOISTENING TO
JUSTIFY SOME SNOW SHOWERS BY LATE AFTN OVR KEWEENAW. ELSEWHERE...
CHANCES OF PCPN ON THURSDAY LOOK MINIMAL. LK EFFECT THEN BECOMES
MORE OF AN ISSUE BY THURSDAY EVENING AS NW WINDS IN BLYR VEER MORE
NORTHERLY. H85 TEMPS FALLING BLO -20C PER GFS/ECMWF LEAD TO SURGE OF
OVER-WATER INSTABILITY WITH LAKE EFFECT EQL AOA 8KFT AND SFC-H85
LAPSE RATES OVR 9C/KM. INSTABILITY IS SUPPLEMENTED BY MID LEVEL
MOISTURE /UP TO H7/. OVERALL SETUP APPEARS FAVORABLE FOR MODERATE
AND POSSIBLY HEAVY LK EFFECT SNOW SHOWERS THURSDAY NIGHT INTO
FRIDAY. SNOW WILL BE FLUFFY AS MAJORITY OF LAKE EFFECT CONVECTIVE
LAYER IS WITHIN THE DENDRITIC GROWTH ZONE. SLR/S FM COBB METHOD IN
BUFKIT RISE WELL ABOVE 20:1.
ONLY MAIN ISSUE TO SORT OUT STILL IS EXACT BLYR WIND DIRECTION. NAM
IS STRONGEST WITH SFC TROUGH AND ASSOCIATED NORTHEAST WINDS DEVELOPING
IN THE WAKE OF THE TROUGH. GFS/ECMWF ARE MORE NORTHERLY WITH THE
WINDS WHILE CANADIAN SHOWS WINDS REMAINING FM NORTHWEST. DO LIKE THE
NAM IDEA INDICATING SHARP WIND SHIFT JUST IN WAKE OF ARCTIC
FRONT...BUT WENT WITH BLEND OF NAM AND PREVIOUS FCST FOR THE WINDS.
RESULT OF THIS CHOICE WAS SOLN WITH WINDS THAT LOOKED LIKE LATEST
ECMWF. GIVEN FAVORABLE OVER-WATER INSTABILITY AND EXPECTED NORTHERLY
WINDS...INCREASED POPS TO LIKELY OVR NORTH WIND SNOW BELTS IN FAR
WEST AND NORTH CENTRAL UPR MI. SEVERAL INCHES OF SNOW SEEMS POSSIBLE
THURSDAY NIGHT INTO FRIDAY...AND WILL CONTINUE TO MENTION THIS IN
THE HAZARDOUS WEATHER OUTLOOK.
IN THE EXTENDED...AGREEMENT IN OVERALL IDEA THAT FIRST PORTION OF
THE WEEKEND WILL BE DOMINANTED BY LINGERING COLD AIRMASS /H85 TEMPS
AROUND -20C/ THAT MOVES IN LATE THIS WEEK. LK EFFECT IN NORTH TO
NORTHWEST FLOW AREAS FRIDAY AND FRIDAY NIGHT WILL DIMINISH ON
SATURDAY AS WINDS TURN MORE WESTERLY AHEAD OF YET ANOTHER COLD
FRONT. BOTH GFS/ECMWF POINT TO CENTER OF POLAR VORTEX WITH H85 TEMPS
NEAR -30C TO FINALLY COME SOUTH INTO GREAT LAKES BY SUNDAY. VORTEX
IS QUITE COMPACT THOUGH AND IT SEEMS DIFFICULT AT BEST TO FCST WHERE
THE CORE OF COLDEST AIR WILL ACTUALLY TRAVEL. GFS IS FARTHER WEST
AND WOULD RESULT IN MIN TEMPS ON SATURDAY NIGHT WELL BLO ZERO IN THE
CNTRL AND EAST. ECMWF IS FARTHER EAST WITH THE VORTEX. SEEMS LIKE
TREND THIS WINTER OF ONLY GLANCING BLOWS OF COLDER AIR OVR UPR LAKES
WOULD SUPPORT THE ECMWF IDEA.
LK EFFECT MAY KICK UP AGAIN LATE IN THE WEEKEND...THOUGH LOW
INVERSION HEIGHTS AND VERY DRY LOW-LEVELS WILL KEEP ACCUMS IN CHECK.
BLEND OF MODELS WORKS FOR NOW...WHICH RESULTED IN SLIGHT CHANCES FOR
SNOW SHOWERS. DUE TO FINE NATURE OF CRYSTALS/NEEDLES IN SUCH A COLD
AIRMASS...THE MAIN IMPACT FM THE SNOW SHOWERS WOULD BE REDUCED
VSBY...ESPECIALLY WITH SOME WIND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1140 AM EST TUE FEB 7 2012
EXPECT MVFR CIGS TO GIVE WAY TO CLEARING/VFR CONDITIONS THIS
AFTERNOON WITH THE ARRIVAL OF DRY LOW LEVEL AIR. AS A HIGH PRESSURE
RIDGE SINKS TO THE SOUTH TONIGHT...EXPECT A GUSTY W WIND AT CMX
UNDER SHARPER PRES GRADIENT ON THE MORE EXPOSED KEWEENAW PENINSULA.
WINDS WILL REMAIN LIGHT AT THE SHELTERED IWD/SAW LOCATIONS. NO
CHANGES FROM PREVIOUS FORECAST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EST TUE FEB 7 2012
SINCE THE N WINDS EARLY THIS MORNING ARE NOT AS STRONG AS EARLIER
ANTICIPATED...GENERALLY NO HIER THAN 25 KT...CANX THE PREVIOUS HEAVY
FREEZING SPRAY WARNING THAT WAS IN EFFECT UNTIL 15Z FOR PORTIONS OF
CENTRAL LK SUP. WINDS TODAY WILL DIMINISH FURTHER WITH THE ARRIVAL
OF A HI PRES RDG/WEAKER PRES GRADIENT. ONCE THE HI CENTER DRIFTS
FARTHER S TONIGHT...A STRONGER W WIND UP TO 30 KTS WILL DEVELOP LATE
UNDER THE SHARPENING PRES GRADIENT BETWEEN THE RETREATING HI AND
FALLING PRES ACROSS ONTARIO. GRADIENT TIGHTENS FURTHER ON WEDNESDAY
WHICH COULD RESULT IN A FEW WESTERLY GALE GUSTS. WINDS BRIEFLY
DIMINISH LATER WEDNESDAY NIGHT INTO THURSDAY MORNING...BUT THEN
VEER NORTH AND INCREASE TO 30 KTS LATE THURSDAY AFTERNOON INTO
THURSDAY NIGHT. HEAVY FREEZING SPRAY IS POSSIBLE THURSDAY NIGHT OVER
MUCH OF THE LAKE. EXPECT NORTH WINDS TO DIMINISH BLO 25 KTS LATER
FRIDAY WITH WINDS STAYING BLO 25 KTS THROUGH THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...07
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...07
MARINE...KC/JLA
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1141 AM EST TUE FEB 7 2012
.SYNOPSIS...
ISSUED AT 427 AM EST TUE FEB 7 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW RATHER SHEARED
POSITIVELY TILTED SHRTWV DROPPING SEWD THRU THE UPR LKS IN
PREVAILING NW FLOW ALF BTWN TROF OVER QUEBEC AND UPR RDG OVER WRN
CAN. ACCOMPANYING SHARP COLD FNT THAT SURGED THRU THE FA YDAY HAS
NOW PUSHED TO THE S. ALTHOUGH MUCH COLDER AIR IS FOLLOWING THE FNT
WITH NNE FLOW AND 00Z H85 TEMPS RANGING FM 0C AT GRB TO -10C AT INL
AND -17C AT YPL...SGNFT LES HAS NOT DEVELOPED EVEN IN AREAS FAVORED
BY THE NNE FLOW. KEY FACTORS APPEAR TO BE IMPRESSIVE DRYING
REFLECTED BY 00Z YPL RAOB /00Z PWAT 0.06 INCH/ THAT IS STEADILY
ERODING THE BACK EDGE OF THE LK CLD AS SHOWN ON IR STLT IMAGERY...
SUBSIDENCE ASSOCIATED WITH FAIRLY VIGOROUS DNVA/CAD/DEEP LYR QVECTOR
DVGC IN THE WAKE OF THE SHRTWV THAT IS CAUSING THE LLVL FLOW TO
BECOME ACYC AND SINK INVRN BASE TO ARND H9 AS SHOWN ON THE 00Z INL
AND YPL RAOBS. UNDER SFC RDG AXIS IN ONTARIO EXTENDING E FM HI
CENTER NEAR LK WINNIPEG...SKIES ARE MOCLR...AND SFC TEMPS/DWPTS HAVE
FALLEN INTO THE ZERO TO -10F RANGE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EST TUE FEB 7 2012
TODAY...COLD NLY FLOW IS FCST TO PERSIST THRU THIS MRNG BEFORE HI
PRES CENTER BLDG FM LK WINNIPEG INTO MN CAUSES THE LLVL FLOW TO BACK
TO THE W BY LATE IN THE DAY. THE COLDEST MODELS...NOTABLY THE 00Z
CNDN AND LOW WRF-ARW...SHOW H85 TEMPS SINKING TO -15 TO -17C OVER
SCNTRL LK SUP THIS MRNG WHILE THE WARMER 00Z NAM/GFS INDICATE THESE
TEMPS WL FALL NO LOWER THAN -14C OR SO. THE DIFFERENCE APPEARS TO BE
RELATED TO THE INVRN HGT FCST...WITH THE WARMER MODELS INDICATING A
LOWER INVRN BASE AOB 3K FT /NAM/ AS COMPARED TO ARND 4K FT
/WRF-ARW/. SINCE DEEP LYR QVECTOR DVGC/SUBSIDENCE WL INTENSIFY THRU
THE DAY AND TRENDS ON OBSVD SKY COVER OVER LK SUP SUG THE INVRN IS
CRASHING...WL TEND TO FOLLOW THE WARMER/LO INVRN BASE DEPICTED BY
THE 00Z NAM. THIS MODEL SHOWS ALMOST NO PCPN EVEN IN THE N WIND SN
BELTS WITH DIFFLUENT FLOW/H925-85 DEWPT DEPRESSION AS HI AS 7-10C
EVEN OVER THE N WIND SN BELTS THAT WOULD OTRW BE FAVORED BY THE LLVL
FLOW. SO ALTHOUGH SOME LES IS LIKELY TO BREAK OUT IN THE NEXT FEW
HRS THRU 12Z WITH THE ARRIVAL OF COLDER AIR...ANY SN ACCUM SHOULD BE
NO MORE THAN ARND AN INCH EVEN OVER THE HIER TERRAIN. BACKING MORE
ACYC FLOW THIS AFTN WITH INVRN BASE REMAINING BLO 3K FT SHOULD
DIMINISH THE LES FURTHER. ALTHOUGH DAYTIME TEMPS WL BE JUST A BIT
BELOW NORMAL...RECENT WARMTH WL MAKE THE DAY FEEL EVEN COLDER...
ESPECIALLY THIS MRNG WITH A STEADY N WIND.
TNGT...SFC HI PRES RDG AXIS IS FCST TO BE NEARLY OVHD IN THE EVNG
BUT THEN SHIFT TO THE S. WITH CONTINUED SUBSIDENCE AND THE FLOW
BACKING TO THE W...EXPECT SKIES TO TURN MOCLR EXCEPT PERHAPS OVER
THE KEWEENAW AND NEAR LK SUP E OF MUNISING. PWAT IS FCST TO BE 0.10
INCH AT 00Z...SO EXPECT A QUICK FALL OF TEMP IN THE EVNG WITH LGT
WINDS...SO ACCELERATED EARLY FALL OF TEMP. ONCE THE RDG SHIFTS TO
THE S OVERNGT...A STRONGER WNW WIND WL DVLP...WITH H925 WINDS FCST
UP TO 30-35 KTS. RETAINED GOING FCST MIN TEMPS AOB THE LO END OF
GUIDANCE PER VERY DRY AIR/OBSVD CHILL UPSTREAM OVER THE MORE
SHELTERED SRN TIER. TEMPS WL BE QUITE A BIT WARMER NEAR THE MORE
EXPOSED LK SUP AND UNDER THE SHARPER PRES GRADIENT FARTHER N OF THE
RDG AXIS...ESPECIALLY OVER THE E WHERE SOME LO CLDS MAY LINGER NEAR
THE SHORE THRU THE NGT UNDER WNW H925 FLOW.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 427 AM EST TUE FEB 7 2012
TROUGH WILL BE EXITING INTO EASTERN CANADA TO START THE LONG TERM
WHICH ALLOWS FOR HEIGHTS TO RISE FM PLAINS INTO GREAT LAKES. AT THE
SFC...HIGH PRESSURE OVER THE PLAINS SLIDES SOUTH ON WEDNESDAY
ALLOWING FOR WESTERLY WINDS AT LOW-LEVELS OVR UPR LAKES INTO
WEDNESDAY NIGHT. WEST WINDS ALONG WITH JUST SCT MID CLOUDS RESULTED
IN RAISING MAX TEMPS TOWARD HIGHER END OF GUIDANCE /AROUND 30 INLAND
AND INTO THE MID 30S NEAR LK SUPERIOR/. NEXT COLD FRONT WILL BE
DROPPING SOUTH ACROSS ONTARIO ON WEDNESDAY NIGHT...SO EXPECT AT
LEAST LGT WEST WINDS TO PERSIST THROUGH THE NIGHT. INLAND AREAS
COULD TRY TO DECOUPLE AND FALL INTO THE TEENS...BUT TEMPS ALONG
SHORELINES OF LK SUPERIOR AND LK MICHIGAN SHOULD STAY IN THE MID TO
UPR 20S. FCST SOUNDINGS FM BOTH NAM AND GFS INDICATE CONDITIONS TOO
DRY TO SUPPORT ANY PCPN AHEAD OF THE FRONT IN THE WESTERLY FLOW.
HAVE REMOVED ANY MENTION OF SNOW UNTIL THURSDAY...EVEN OVR THE
KEWEENAW PENINSULA.
CHANGES BEGIN TO OCCUR LATER THURSDAY AS ARCTIC COLD FRONT IS FCST
TO ARRIVE. PROBABLY WILL SEE FALLING TEMPS...BUT AT THIS POINT STUCK
WITH NORMAL DIURNAL TEMP CURVE AS PRIMARY COOLING FM FROPA DOES NOT
OCCUR UNTIL LATE IN THE DAY. SOUNDINGS SHOW SUFFICIENT MOISTENING TO
JUSTIFY SOME SNOW SHOWERS BY LATE AFTN OVR KEWEENAW. ELSEWHERE...
CHANCES OF PCPN ON THURSDAY LOOK MINIMAL. LK EFFECT THEN BECOMES
MORE OF AN ISSUE BY THURSDAY EVENING AS NW WINDS IN BLYR VEER MORE
NORTHERLY. H85 TEMPS FALLING BLO -20C PER GFS/ECMWF LEAD TO SURGE OF
OVER-WATER INSTABILITY WITH LAKE EFFECT EQL AOA 8KFT AND SFC-H85
LAPSE RATES OVR 9C/KM. INSTABILITY IS SUPPLEMENTED BY MID LEVEL
MOISTURE /UP TO H7/. OVERALL SETUP APPEARS FAVORABLE FOR MODERATE
AND POSSIBLY HEAVY LK EFFECT SNOW SHOWERS THURSDAY NIGHT INTO
FRIDAY. SNOW WILL BE FLUFFY AS MAJORITY OF LAKE EFFECT CONVECTIVE
LAYER IS WITHIN THE DENDRITIC GROWTH ZONE. SLR/S FM COBB METHOD IN
BUFKIT RISE WELL ABOVE 20:1.
ONLY MAIN ISSUE TO SORT OUT STILL IS EXACT BLYR WIND DIRECTION. NAM
IS STRONGEST WITH SFC TROUGH AND ASSOCIATED NORTHEAST WINDS DEVELOPING
IN THE WAKE OF THE TROUGH. GFS/ECMWF ARE MORE NORTHERLY WITH THE
WINDS WHILE CANADIAN SHOWS WINDS REMAINING FM NORTHWEST. DO LIKE THE
NAM IDEA INDICATING SHARP WIND SHIFT JUST IN WAKE OF ARCTIC
FRONT...BUT WENT WITH BLEND OF NAM AND PREVIOUS FCST FOR THE WINDS.
RESULT OF THIS CHOICE WAS SOLN WITH WINDS THAT LOOKED LIKE LATEST
ECMWF. GIVEN FAVORABLE OVER-WATER INSTABILITY AND EXPECTED NORTHERLY
WINDS...INCREASED POPS TO LIKELY OVR NORTH WIND SNOW BELTS IN FAR
WEST AND NORTH CENTRAL UPR MI. SEVERAL INCHES OF SNOW SEEMS POSSIBLE
THURSDAY NIGHT INTO FRIDAY...AND WILL CONTINUE TO MENTION THIS IN
THE HAZARDOUS WEATHER OUTLOOK.
IN THE EXTENDED...AGREEMENT IN OVERALL IDEA THAT FIRST PORTION OF
THE WEEKEND WILL BE DOMINANTED BY LINGERING COLD AIRMASS /H85 TEMPS
AROUND -20C/ THAT MOVES IN LATE THIS WEEK. LK EFFECT IN NORTH TO
NORTHWEST FLOW AREAS FRIDAY AND FRIDAY NIGHT WILL DIMINISH ON
SATURDAY AS WINDS TURN MORE WESTERLY AHEAD OF YET ANOTHER COLD
FRONT. BOTH GFS/ECMWF POINT TO CENTER OF POLAR VORTEX WITH H85 TEMPS
NEAR -30C TO FINALLY COME SOUTH INTO GREAT LAKES BY SUNDAY. VORTEX
IS QUITE COMPACT THOUGH AND IT SEEMS DIFFICULT AT BEST TO FCST WHERE
THE CORE OF COLDEST AIR WILL ACTUALLY TRAVEL. GFS IS FARTHER WEST
AND WOULD RESULT IN MIN TEMPS ON SATURDAY NIGHT WELL BLO ZERO IN THE
CNTRL AND EAST. ECMWF IS FARTHER EAST WITH THE VORTEX. SEEMS LIKE
TREND THIS WINTER OF ONLY GLANCING BLOWS OF COLDER AIR OVR UPR LAKES
WOULD SUPPORT THE ECMWF IDEA.
LK EFFECT MAY KICK UP AGAIN LATE IN THE WEEKEND...THOUGH LOW
INVERSION HEIGHTS AND VERY DRY LOW-LEVELS WILL KEEP ACCUMS IN CHECK.
BLEND OF MODELS WORKS FOR NOW...WHICH RESULTED IN SLIGHT CHANCES FOR
SNOW SHOWERS. DUE TO FINE NATURE OF CRYSTALS/NEEDLES IN SUCH A COLD
AIRMASS...THE MAIN IMPACT FM THE SNOW SHOWERS WOULD BE REDUCED
VSBY...ESPECIALLY WITH SOME WIND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1140 AM EST TUE FEB 7 2012
EXPECT MVFR CIGS TO GIVE WAY TO CLEARING/VFR CONDITIONS THIS
AFTERNOON WITH THE ARRIVAL OF DRY LOW LEVEL AIR. AS A HIGH PRESSURE
RIDGE SINKS TO THE SOUTH TONIGHT...EXPECT A GUSTY W WIND AT CMX
UNDER SHARPER PRES GRADIENT ON THE MORE EXPOSED KEWEENAW PENINSULA.
WINDS WILL REMAIN LIGHT AT THE SHELTERED IWD/SAW LOCATIONS. NO
CHANGES FROM PREVIOUS FORECAST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EST TUE FEB 7 2012
SINCE THE N WINDS EARLY THIS MORNING ARE NOT AS STRONG AS EARLIER
ANTICIPATED...GENERALLY NO HIER THAN 25 KT...CANX THE PREVIOUS HEAVY
FREEZING SPRAY WARNING THAT WAS IN EFFECT UNTIL 15Z FOR PORTIONS OF
CENTRAL LK SUP. WINDS TODAY WILL DIMINISH FURTHER WITH THE ARRIVAL
OF A HI PRES RDG/WEAKER PRES GRADIENT. ONCE THE HI CENTER DRIFTS
FARTHER S TONIGHT...A STRONGER W WIND UP TO 30 KTS WILL DEVELOP LATE
UNDER THE SHARPENING PRES GRADIENT BETWEEN THE RETREATING HI AND
FALLING PRES ACROSS ONTARIO. GRADIENT TIGHTENS FURTHER ON WEDNESDAY
WHICH COULD RESULT IN A FEW WESTERLY GALE GUSTS. WINDS BRIEFLY
DIMINISH LATER WEDNESDAY NIGHT INTO THURSDAY MORNING...BUT THEN
VEER NORTH AND INCREASE TO 30 KTS LATE THURSDAY AFTERNOON INTO
THURSDAY NIGHT. HEAVY FREEZING SPRAY IS POSSIBLE THURSDAY NIGHT OVER
MUCH OF THE LAKE. EXPECT NORTH WINDS TO DIMINISH BLO 25 KTS LATER
FRIDAY WITH WINDS STAYING BLO 25 KTS THROUGH THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...KC
SHORT TERM...KC
LONG TERM...JLA
AVIATION...07
MARINE...KC/JLA
AREA FORECAST DISCUSSION
NWS GLASGOW MT
916 AM MST TUE FEB 7 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
LOW CLOUDS AND ISOLATED FLURRIES CONTINUE OVER THE NORTHEAST
MONTANA THIS MORNING. BACK EDGE OF THE CLOUDS STILL BACK IN
ALBERTA BUT NOT MOVING MUCH...SO HAVE EXTENDED FLURRIES INTO THE
AFTERNOON. WITH THE CLOUDS HANGING AROUND EXPECTED TEMPERATURES TO
NOT SHOW MUCH CHANGE SO ALSO LOWERED FORECAST MAXT. EBERT
PREVIOUS SHORT TERM DISCUSSION...1040 MB SURFACE HIGH CENTERED
OVER CENTRAL SK THE MAIN INFLUENCE ON OUR WEATHER AS IT MOVES
SLOWLY SSE. TEMPS NOT PARTICULARLY COLD WITH THIS.
NE FLOW AND RESULTING UPSLOPE INFLUENCED STRATUS COVERS ALL OF NE
MT...W ND...AND MOST OF S SK. THIS HAS PROVED A MAJOR FORECAST
BUGABOO. MOST MODELS HAVE BEEN OF LITTLE HELP AND WAY TOO FAST IN
CLEARING THE STRATUS OUT. SATELLITE FOG LOOP SHOWS THE STRATUS NOT
MOVING OR CHANGING MUCH. AT THIS RATE...WILL HAVE TO KEEP SKIES CLOUDY
THROUGH MOST OF THE DAY. DO EXPECT SOME CLEARING TO START SHOWING
IN TOUR N THIS AFTERNOON. AS THE SURFACE HIGH MOVES NEAREST TO US
AND THEN SE...IT SHOULD CLEAR ALL STRATUS OUT THIS EVENING. WILL CONFINE
FLURRY MENTION TO OUR EXTREME SW WHERE THERE ARE LAYERED HIGHER
CLOUD STILL ABOVE THE STRATUS.
OVERCAST HELD LOWS UP 10F OR MORE THAN EXPECTED LAST NIGHT.
HOWEVER WITH THE STRATUS STICKING AROUND MOST OF THE DAY...AND
COLDER PART OF THE AIRMASS NOW OVER US...HIGHS WON`T BE VERY MUCH
WARMER THAN THIS MORNINGS LOWS. COLDER TONIGHT THOUGH WITH
CLEARING SKIES FINALLY.
REX BLOCK UPPER PATTERN HAS BEEN BREAKING DOWN. UPPER RIDGE WILL
SHIFT AROUND A LITTLE...BUILDING STRONGLY N OVER THE PACIFIC COAST
STATES AND BC. THIS WILL INCREASE THE NNW FLOW ALOFT OVER OUR AREA
BETWEEN HE RIDGE AND THE HUDSON BAY LOW.
THE CANADIAN HIGH PRESSURE MOVES SE OUT OF THE AREA WED...ALLOWING
FOR SOME WARMING UNDER SUNNY SKIES. MODELS HAVE BEEN TRENDING
SLOWER WITH THE NEXT COLD FRONT THAT ARRIVES IN THE NNW FLOW...NOW
MOVING THRU THE CWA THURSDAY. 850 MB WINDS INCREASE TO AS HIGH AS
40KT 12-15Z. MODEL FORECAST SOUNDINGS ARE JUST SHORT OF DRY
ADIABATIC MIXED TO AROUND 900 MB AT THAT TIME AS MODERATE COLD
ADVECTION STARTS IN OUR N. SO TIMING NOT QUITE IDEAL TO MIX
MAXIMUM WINDS TO SURFACE...BUT IT WILL BE WINDY. AS WE MIX DRY
ADIABATICALLY TO ABOVE 900 MB IN THE AFTERNOON...WINDS AT THAT
LEVEL ARE LESS THEN. ANOTHER DRY COLD FRONT. MODELS INDICATE THERE
WILL BE JUST A SHORTLIVED NARROW BAND OF STRATUS BEHIND THE FRONT. SIMONSEN
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
THE EXTENDED BEGINS WITH HIGH PRESSURE OVER MANITOBA AND A
STATIONARY FRONT UP AGAINST THE ROCKY MOUNTAIN FRONT RANGE. MODELS
IN FAIR AGREEMENT WITH THIS SOLUTION FOR THE START OF THE PERIOD
FRIDAY MORNING.
FRIDAY THROUGH THE WEEKEND THE UPPER LOW OVER HUDSON BAY MOVES
INTO QUEBEC DRAGGING THE HIGH PRESSURE SYSTEM OVER MANITOBA SOUTH
AND EAST TOWARDS THE GREAT LAKES. THE NEXT EFFECT WILL BE A
WARMING TREND FOR NORTHEAST MONTANA. THE STATIONARY FRONT WILL
BECOME MORE OF A LEE TROUGH AND COULD PROVIDE A FOCUS OVER THE FAR
WESTERN ZONES FOR SOME VERY LIGHT PRECIPITATION. WILL KEEP THE
MENTION OF PRECIPITATION OUT FOR THE ZONES AT THIS TIME.
EARLY NEXT WEEK...THE EC AND GFS BRING AN UPPER LEVEL LOW THROUGH
NORTHEAST MONTANA AT DIFFERENT TIME STEPS... FOR NOW WILL JUST
KEEP SLIGHT CHANCE POPS IN THE FORECAST UNTIL THE MODELS COME
TOGETHER WITH FUTURE RUNS. PROTON
&&
.AVIATION...
A VERY PERSISTENT MVFR STRATUS DECK IS HOLDING OVER THE REGION. DO
EXPECT THE MVFR CEILINGS TO CONTINUE FOR ALL TAF SITES THROUGH 18Z. THE
CEILINGS SHOULD SLOWLY BREAK UP AFTER THAT. FOLLOWING THE HRRR AND
SREF GUIDANCE THIS MORNING SINCE THE MOS PRODUCTS HAVE HANDLED
THIS EVENT POORLY. PROTON/BMICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BUFFALO NY
339 PM EST TUE FEB 7 2012
.SYNOPSIS...
COLDER OVERNIGHT LOWS TONIGHT BEHIND A COLD FRONT WITH JUST STRAY
FLURRIES AND LIGHT SNOW SHOWERS THIS EVENING. A WEST TO EAST
TRACKING SNOW STORM WILL REMAIN SOUTH OF THE STATE LINE
WEDNESDAY...THOUGH CLOUDS WILL THICKEN ACROSS SOUTHERN PORTIONS OF
WESTERN AND CENTRAL NEW YORK. TEMPERATURES WEDNESDAY WILL REACH
INTO THE LOW 30S FOR MANY AREAS...AND A FEW DEGREES WARMER
THURSDAY UNDER ADDITIONAL SUNSHINE.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AT 20Z A COLD FRONT CONTINUES TO WEAKEN AND SLOW AS IT PUSHES SOUTHWARD INTO
NORTHERN PENNSYLVANIA THIS AFTERNOON WITH A NORTHERLY FLOW BEHIND
THE FRONT. HIGH PRESSURE OVER THE NORTHERN PLAINS CONTINUES TO RIDGE
EASTWARD BEHIND THIS SFC COLD FRONT.
VISIBLE SATELLITE IMAGERY DISPLAYS MUCH OF THE EASTERN LAKE ONTARIO
REGION NOW MOSTLY SUNNY...WITH A CLOUDY LOW DECK OF CLOUDS SOUTH OF
LAKE ONTARIO.
RADAR DISPLAYS LIGHT SNOW ACROSS AREAS SOUTH OF LAKE ONTARIO AND
WILL CONTINUE WITH THE LOW CHC POPS FOR SNOW SOUTH OF LAKE
ONTARIO...TAPERING OFF TO FLURRIES SOUTH OF THE THRUWAY. WITH LACK
OF MOISTURE IN THE SNOW GROWTH ZONE...AND LIGHT WINDS EXPECT JUST
THE FINE GRAINY SNOW TO CONTINUE. ACTIVITY SHOULD CONTINUE TO
DIMINISH THROUGH THE OVERNIGHT TIME PERIOD AS LOW LEVEL MOISTURE
DIMINISHES.
SEVERAL CHALLENGES IN THE OVERNIGHT TIME PERIOD ACROSS THE EASTERN
GREAT LAKES REGION. FIRST CHALLENGE IS THE TIMING OF THE CLEARING
BEHIND THE COLD FRONT. BOTH THE 12Z GFS/NAM...09Z SREF AND THE
LATEST MESOSCALE RUC LINGER LOW LEVEL MOISTURE AROUND 2-3K FEET
SOUTH OF LAKE ONTARIO. THE FLOW UP THROUGH 5K FEET OVERNIGHT WILL
REMAIN LIGHT...LESS THAN 10 KNOTS...BUT IT WILL HAVE A NORTH TO
NORTHEASTERLY COMPONENT WHICH WILL LEAD TO SOME UPSLOPE ACROSS
INTERIOR WESTERN AND CENTRAL NEW YORK. WHILE THE CLEARING LINE IS
NEAR THE MOHAWK VALLEY AND THE SOUTHERN LAKE ONTARIO SHORELINE THIS
LATE AFTERNOON...EXPECT THIS CLEARING LINE TO SLOW THIS EVENING WITH
THE SETTING SUN AND LOW CLOUDS TO REMAIN SOUTH OF LAKE ONTARIO
WITHIN THE LOW LEVEL MOISTURE. EXPECT THE NORTHERN HALF OF WNY AND
CNY TO HAVE CLEARING THROUGH THE OVERNIGHT...THOUGH BY TIME THE
CLEARING OF LOW CLOUDS REACHES THE SOUTHERN TIER...MID AND HIGH
LEVEL CLOUDS WILL BE THICKENING. THE CHALLENGE IS WITH THE CLEARING
LINE VERY CLOSE...CLOUDS MAY DISSIPATE QUICKER THAN FORECASTED
ESPECIALLY JUST SOUTH OF LAKE ONTARIO...WITH THE CURRENT FORECAST
TOO PESSIMISTIC ON OVERNIGHT CLOUD COVER.
CHALLENGE TWO TONIGHT WILL BE OVERNIGHT TEMPERATURES. WITH THE LOW
CLOUDS LINGERING THROUGH MUCH OF THE NIGHT TOWARDS THE SOUTH...AND MID
AND HIGH LEVEL CLOUDS ARRIVING OVERNIGHT WILL HEDGE ABOVE MODEL
GUIDANCE TO THE SOUTH FOR OVERNIGHT LOWS WITH READINGS IN THE LOW TO
MID 20S.
THE CHALLENGE WILL BE TO THE NORTH...ESPECIALLY THE EASTERN LAKE
ONTARIO REGION WHERE THE SKIES WILL BE MAINLY CLEAR AND WINDS LIGHT
AS HIGH PRESSURE RIDGES INTO THE REGION. TEMPERATURES ARE EXPECTED
TO FALL INTO THE SINGLE DIGITS...TO BELOW ZERO ACROSS THE NORTH
COUNTRY OVERNIGHT. HOWEVER DO NOT EXPECT TEMPERATURES TO FALL MUCH BELOW
MODEL GUIDANCE AS AN UPPER LEVEL TROUGH...AND WAA AT 925 HPA THROUGH
THE NIGHT ARE NOT FAVORABLE FOR CLASSIC RADIATIONAL COOLING.
TEMPERATURES AT BETWEEN 925 HPA AND 850 HPA ONLY DROP TO AROUND -9
TO -12C...WHICH IS NORMAL FOR THIS TIME OF YEAR...AND INDICATIVE
THAT THIS AIRMASS BEHIND THE COLD FRONT IS NOT YOUR CLASSIC DEEP
COLD ARCTIC AIRMASS. HOWEVER WITH THE LIGHT WINDS AND STILL ICY SNOW
COVER TEMPERATURES MAY DROP COLDER THAN FORECASTED ACROSS THE
EASTERN LAKE ONTARIO REGION. ELSEWHERE WILL GO NEAR MODEL
GUIDANCE...THOUGH TIMING OF THE CLEARING MAY CHANGE THE OVERNIGHT
LOWS EITHER SIDE OF THE FORECAST.
TOMORROW AN UPPER LEVEL SHORT WAVE WITHIN A ZONAL FLOW WILL DRIVE A
STORM SYSTEM FROM THE MID MISSISSIPPI VALLEY TO THE SOUTHERN MID
ATLANTIC. PRECIPITATION FROM THIS SYSTEM IS EXPECTED TO REMAIN JUST
SOUTH OF THE STATE LINE...THOUGH MID AND HIGH LEVEL CLOUDS WILL
CROSS THE REGION. THESE CLOUDS WILL CREATE A CLOUDY DAY NEAR THE
STATE LINE WEDNESDAY...THOUGH FARTHER NORTH WHERE MOISTURE WILL BE
LESS EXPECT SUNSHINE TO BE MORE PLENTIFUL WITH MOSTLY SUNNY SKIES
ACROSS THE NORTH COUNTRY. TEMPERATURES WEDNESDAY WILL CLIMB TO NEAR
SEASONAL AVERAGES WITH LOW TO MID 30S PLENTIFUL ACROSS THE REGION.
WINDS WILL BE LIGHT TO START THE DAY AND BECOME MORE SOUTH TO
SOUTHWESTERLY LATE...AND INCREASE IN SPEED SOME AS WARM AIR ALOFT
BEGINS TO PUSH INTO THE REGION.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
WEDNESDAY EVENING A MID LEVEL TROUGH WILL BE MOVING ACROSS THE MID
ATLANTIC STATES WITH AN ASSOCIATED VERY WEAK SURFACE WAVE
REFLECTION. LATEST 12Z MODEL GUIDANCE REMAINS CONSISTENT IN KEEPING
ANY LIGHT SNOW WITH THIS SYSTEM JUST SOUTH OF THE PA/NY BORDER
WEDNESDAY EVENING. MID LEVEL CLOUDS WILL QUICKLY DECREASE FROM
NORTHWEST TO SOUTHEAST DURING THE EVENING AS THIS WAVE PULLS OFF THE
EAST COAST...LEAVING MOST AREAS MAINLY CLEAR OVERNIGHT.
THE ONLY POTENTIAL CONCERN IS THE POSSIBILITY OF SOME LAKE
EFFECT/UPSLOPE CLOUDS DEVELOPING EAST OF THE LAKES
OVERNIGHT...SIMILAR TO SCENARIOS WE HAVE SEEN IN RECENT DAYS.
WESTERLY FLOW OF ABOUT -6C AIR AT 850MB MAY BE ENOUGH TO ALLOW SOME
LAKE STRATUS TO DEVELOP...ESPECIALLY WITH AN ADDED BOOST FROM
UPSLOPE FLOW ACROSS THE WESTERN SOUTHERN TIER AND TUG HILL REGIONS.
WILL CONTINUE WITH HIGHER CLOUD AMOUNTS IN THESE AREAS LATER
WEDNESDAY NIGHT INTO THURSDAY MORNING TO ACCOUNT FOR THIS POTENTIAL.
OTHERWISE ON THURSDAY EXPECT MOST AREAS TO SEE A DECENT AMOUNT OF
SUNSHINE WITH INCREASING SOUTHWEST FLOW BOOSTING 850MB TEMPS UP TO
AROUND -4C. WITH NO SNOW ON THE GROUND IN MOST AREAS AND AMPLE
MIXING AND SUNSHINE...THIS SHOULD ALLOW TEMPS TO CLIMB INTO THE MID
TO UPPER 30S IN MANY AREAS...WITH LOW 40S IN THE WARMER SPOTS OF THE
GENESEE VALLEY AND FINGER LAKES. A SOUTHWEST FLOW OFF LAKE ERIE WILL
PREVENT THE BUFFALO AREA AND MUCH OF THE NIAGARA FRONTIER FROM
REACHING 40. IT WILL BE QUITE BREEZY AS WELL WITH GUSTS IN THE 30-35
MPH RANGE.
MORE OF THE SAME THURSDAY NIGHT INTO FRIDAY MORNING WITH DEEP
SOUTHWESTERLY FLOW KEEPING TEMPS ABOVE AVERAGE WITH DRY AND MAINLY
CLEAR SKIES. THE BREEZE WILL STAY UP THURSDAY NIGHT...KEEPING LOW
TEMPS ABOVE SEASONAL AVERAGES.
LATE FRIDAY INTO FRIDAY NIGHT THE NEXT SYSTEM OF INTEREST
APPROACHES...AND FORECAST UNCERTAINTY ALSO INCREASES. IN A GENERAL
SENSE...A LONGWAVE TROUGH WILL BEGIN TO CARVE OUT ACROSS EASTERN
CANADA WITH THE FIRST LOBE OF LOWER HEIGHTS SWINGING DOWN THROUGH
THE GREAT LAKES FRIDAY NIGHT. THE 12Z GFS REMAINS CONSISTENT WITH
PREVIOUS RUNS AND HAS A CLEAN...SIMPLE ARCTIC FRONT PASSAGE FRIDAY
NIGHT WITH 850MB TEMPS DROPPING TO -22C TO -24C BY SATURDAY MORNING.
THE ECMWF AND CANADIAN GEM ALSO REMAIN CONSISTENT WITH THEIR
PREVIOUS RUNS AND DEVELOP A WEAK WAVE OF LOW PRESSURE ALONG THE
ARCTIC FRONT OVER THE LOWER LAKES. THIS WOULD DO TWO THINGS.
FIRST...THE WAVE WOULD BRING A GENERAL LIGHT SNOW TO THE ENTIRE
REGION. SECOND...IT WOULD ALSO SLOW THE ARRIVAL OF THE COLDEST AIR
UNTIL LATER IN THE DAY SATURDAY. THE ECMWF AND GEM ARE ALSO NOT AS
EXTREME WITH THE COLD AIR BEHIND...WITH 850MB TEMPS BOTTOMING OUT
-18C.
IN EITHER SCENARIO...THE ARCTIC FROPA OR WAVE OF LOW PRESSURE...
MOST AREAS SHOULD SEE AT LEAST SOME SNOWFALL FRIDAY NIGHT SO THIS
GIVES ENOUGH CONFIDENCE TO RAISE POPS TO LIKELY. THE MAIN FORECAST
CHALLENGE THEN IS HOW QUICKLY TO BRING IN THE COLD AIR. FOR NOW HAVE
GONE WITH A MIDDLE OF THE ROAD SOLUTION...BUT IF THE GFS VERIFIES
FRIDAY NIGHT LOWS WILL BE MUCH COLDER THAN CURRENTLY FORECAST...AND
IF THE ECMWF/GEM IDEA VERIFIES THEY WILL BE MILDER.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MODEL UNCERTAINTY ABOUNDS NEXT WEEKEND WITH MEDIUM RANGE GUIDANCE
CONTINUING TO STRUGGLE WITH THE DETAILS OF A LONGWAVE TROUGH
AMPLIFICATION IN EASTERN CANADA AND NEW ENGLAND. THE LATEST 12Z
ECMWF HAS OFFERED ANOTHER EXTREME SOLUTION...DROPPING A MAJOR CHUNK
OF THE POLAR VORTEX INTO NORTHERN NEW ENGLAND ON MONDAY WITH 850MB
TEMPS BOTTOMING OUT AROUND -34C OVER THE ADIRONDACKS AND ABOUT -24C
ACROSS WESTERN NY. THE GFS IS LESS AMPLIFIED...KEEPING A FLATTER
TROUGH WHICH DIRECTS THE COLDEST AIR THROUGH NORTHERN NEW ENGLAND
SUNDAY AND MONDAY...WITH A STEADY MODERATING TREND ACROSS THE LOWER
LAKES.
THE ECMWF IS AN EXTREME SOLUTION FOR SURE...AND SUCH EXTREME
SOLUTIONS THIS FAR OUT RARELY VERIFY. THE ECMWF IS ALSO STRUGGLING
MORE THAN OTHER MODEL GUIDANCE WITH RUN TO RUN CONSISTENCY INVOLVING
THESE DETAILS. FOR NOW WILL JUST KEEP TEMPS A LITTLE COOLER THAN THE
GFS SOLUTION FOR SUNDAY AND MONDAY ESPECIALLY ACROSS THE NORTH
COUNTRY. HAVE ALSO MAINTAINED A CHANCE OF SNOW SHOWERS FOR MOST OF
THE WEEKEND WITH COLD NORTHWEST FLOW BECOMING MORE WESTERLY ON
SUNDAY. THERE WILL BE SOME LAKE EFFECT/ENHANCED SNOW...BUT WITH THE
BIG RUN TO RUN AND INTER-MODEL DIFFERENCES THERE IS NO WAY OF
KNOWING THE DETAILS OF WHEN AND WHERE...OR AMOUNTS YET.
IT DOES APPEAR THAT A MODERATING TREND WILL BEGIN NEXT WEEK ONCE
AGAIN...ALTHOUGH THE DEGREE OF WARMING IS QUITE DIFFERENT BETWEEN
THE ECMWF/GFS SOLUTIONS. THE 12Z GFS SHOWS A GENERAL LIGHT SNOWFALL
FOR DAY 7 TUESDAY...BUT THIS HAS LITTLE SUPPORT FROM THE ECMWF OR
MOST GEFS ENSEMBLE MEMBERS SO FOR NOW WILL KEEP TUESDAY DRY WITH
TEMPS MODERATING BACK TO A LITTLE ABOVE AVERAGE.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
FOR THE 21Z TAF UPDATE LOW MVFR AND PATCHY IFR FLIGHT CONDITIONS
WERE FOUND SOUTH OF LAKE ONTARIO WITH LIGHT NORTHERLY WINDS. LOW
LEVEL MOISTURE WILL MAINTAIN LOW CIGS THIS LATE AFTERNOON WITH
SCATTERED SNOW SHOWERS...ESPECIALLY NEAR THE KJHW AND KROC
TERMINALS.
AS MOISTURE BEGINS TO DIMINISH THIS EVENING THE SCATTERED FLURRIES
AND SNOW SHOWERS WILL COME TO AND END...THOUGH WITH THE LIGHT
UPSLOPE FLOW MVFR LEVEL CLOUDS WILL HANG TOUGH TILL THE OVERNIGHT
TIME PERIOD.
EXCEPTION TO THIS WILL BE THE NORTH COUNTRY WHERE SKIES WILL
CONTINUE TO REMAIN MAINLY CLEAR OVERNIGHT.
EXPECT A RETURN TO VFR FLIGHT CONDITIONS LATE OVERNIGHT...WITH VFR
CONDITIONS REMAINING THROUGH THE DAY WEDNESDAY...THOUGH AN OVC MID
LEVEL DECK OF CLOUDS WILL CROSS NEAR THE STATE LINE. WINDS THROUGH
THE FIRST HALF OF WEDNESDAY WILL REMAIN LIGHT...GENERALLY UNDER 10
KNOTS.
OUTLOOK...
WEDNESDAY AND THURSDAY...MAINLY VFR.
FRIDAY...AREAS OF MVFR/IFR IN SNOW SHOWERS LATE AND OVERNIGHT.
SATURDAY AND SUNDAY...AREAS MVFR IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
HIGH PRESSURE RIDGING INTO THE REGION FROM THE NORTHERN PLAINS WILL
CREATE A QUIET PERIOD WITH RELATIVELY LIGHT WINDS TONIGHT AND
WEDNESDAY ACROSS THE EASTERN GREAT LAKES. WINDS WILL INCREASE
OVERNIGHT WEDNESDAY AND INTO THURSDAY AND FRIDAY WITH WAVES AND
WINDS LIKELY REACHING SMALL CRAFT CRITERIA ON THE LAKES BOTH
THURSDAY AND FRIDAY.
&&
.CLIMATE...
THE INCREDIBLE WARMTH AND LACK OF SNOW CONTINUES FOR ANOTHER WEEK
HERE IN WESTERN AND CENTRAL NY. AS WE GO DEEPER AND DEEPER INTO THE
WINTER SEASON...THE STATS FOR LACK OF SNOW AND TEMPERATURES ARE
BECOMING QUITE IMPRESSIVE.
FOR BOTH BUFFALO AND ROCHESTER STATS AND RANKINGS BELOW...THE ENTIRE
141 YEARS OF RECORD WERE USED UNLESS OTHERWISE NOTED.
FOR ROCHESTER...
SNOWFALL FOR THE SEASON THROUGH FEB 5TH STANDS AT 25.5 INCHES.
NORMAL TO DATE WOULD BE 61.5 INCHES. THIS RANKS AS THE 10TH LEAST ON
RECORD. THERE IS A CAVEAT TO THIS...TWO OF THE YEARS THAT RANK WITH
LESS SNOW FROM THE 1800S HAVE SOME MISSING DATA...SO THE RANKING MAY
EVEN BE A NOTCH OR TWO HIGHER. THE LEAST SNOWY SEASON ON RECORD
THROUGH FEB 5TH WAS 1932-33 WITH 11.0 INCHES.
NUMBER OF DAYS WITH SNOW ON THE GROUND IS A VERY TELLING METRIC ON
WINTER SEVERITY SINCE IT RELATES TO BOTH SNOWFALL AND TEMPERATURE.
THIS YEAR THERE HAVE BEEN 9 DAYS WITH AN INCH OR MORE OF SNOW ON THE
GROUND. THE NORMAL FOR THE ENTIRE SEASON IS 76 DAYS...AND THE RECORD
LOW NUMBER OF DAYS IS 35 SET BACK IN 1932-33. IF THE PATTERN
CONTINUES THROUGH THE REST OF WINTER AND EARLY SPRING...THE ALL TIME
RECORD MAY BE IN REACH. NOTE THAT SNOW DEPTH DATA IS NOT COMPLETE IN
THE EARLY YEARS OF RECORD...SO THE SNOW DEPTH DATA WAS ANALYZED
SINCE THE WINTER OF 1926-27.
TEMPERATURES HAVE ALSO BEEN VERY MILD MOST OF THE TIME FROM LATE
FALL THROUGH THE WINTER TO THIS POINT. THE AVERAGE TEMPERATURE FROM
NOVEMBER 1ST THROUGH FEBRUARY 5TH WAS 36.9 DEGREES...WHICH IS ABOUT
6 DEGREES ABOVE AVERAGE. THIS RANKS AS 4TH WARMEST ON RECORD FOR
THAT STRETCH. THE RECORD WARMEST DURING THAT PERIOD WAS 39.9 DEGREES
SET IN 1931-32.
FOR BUFFALO...
SNOWFALL FOR THE SEASON THROUGH FEB 5TH STANDS AT 24.6 INCHES.
NORMAL TO DATE WOULD BE 65.0 INCHES. THIS RANKS AS THE 12TH LEAST ON
RECORD. THE LEAST SNOWY SEASON ON RECORD THROUGH FEB 5TH WAS
1889-1890 WITH 11.9 INCHES. A MORE RECENT YEAR WITH VERY LOW SNOW
WAS 1988-1989 WITH 20.9 INCHES THROUGH FEB 5TH...WHICH RANKS AS 5TH
LEAST ON RECORD.
NUMBER OF DAYS WITH SNOW ON THE GROUND IS A VERY TELLING METRIC ON
WINTER SEVERITY SINCE IT RELATES TO BOTH SNOWFALL AND TEMPERATURE.
THIS YEAR THERE HAVE BEEN 15 DAYS WITH AN INCH OR MORE OF SNOW ON
THE GROUND. THE NORMAL FOR THE ENTIRE SEASON IS 72 DAYS...AND THE
RECORD LOW NUMBER IS 29 DAYS SET BACK IN 1918-19. IF THE PATTERN
CONTINUES THROUGH THE REST OF WINTER AND EARLY SPRING...THE ALL TIME
RECORD MAY BE IN REACH. NOTE THAT SNOW DEPTH DATA IS NOT COMPLETE IN
THE EARLY YEARS OF RECORD...SO THE SNOW DEPTH DATA WAS ANALYZED
SINCE THE WINTER OF 1893-94.
TEMPERATURES HAVE ALSO BEEN VERY MILD MOST OF THE TIME FROM LATE
FALL THROUGH WINTER TO THIS POINT. THE AVERAGE TEMPERATURE FROM
NOVEMBER 1ST THROUGH FEBRUARY 5TH IS 37.2 DEGREES...WHICH IS ABOUT 6
DEGREES ABOVE AVERAGE. THIS RANKS AS THE 2ND WARMEST ON RECORD FOR
THAT STRETCH. THE RECORD WARMEST DURING THAT PERIOD WAS 37.4 DEGREES
SET IN 2001-2002.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...THOMAS
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...THOMAS
MARINE...THOMAS
CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
127 PM EST TUE FEB 7 2012
.SYNOPSIS...
HIGH PRESSURE THIS AFTERNOON. A COLD FRONT PASSES WITH AN UPPER
DISTURBANCE TO PROVIDE A COLD RAIN OR SNOW TUESDAY NIGHT AND
WEDNESDAY. ARCTIC AIR WITH SNOW SHOWERS ARRIVES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATED...
NO CHANGES NEEDED FOR 15Z UPDATE. STRATUS DECK OVER SOUTHEAST OHIO
WILL BE VERY SLOW TO ENCROACH INTO WEST VIRGINIA.
PREVIOUS DISCUSSION BELOW...
WILL BE WATCHING LOW STRATUS DECK MOVING SE INTO OH EARLY THIS
MORNING. THIS SEEMS BE MARKED BY A WIND SHIFT TO MORE NW IN LWR
LVLS. HI RES LCL MDLS MDLS SEEM TO HAVE A MUCH BETTER HANDLE ON
THIS AS NAM AND GLOBAL MDLS ARE TOO SLOW AND NW WITH THIS. WILL
USE RUC AND WRF MDLS FOR TIMING...POISED TO MOVE INTO
PERRY...MORGAN...VINTON CO 10-12Z BEFORE PUTTING ON THE BRAKES IN
ITS SE ADVANCEMENT. OTHERWISE RVR VALLEY FG CENTRAL AND SOUTHERN
WV/SW VA WILL QUICKLY LIFT BY MID MORNING.
AFOREMENTIONED STRATUS DECK WILL VERY SLOWLY EDGE S AND E THRU THE
DAY...MORE E AND THAN S. HAVE INCREASING CLDS ACROSS NORTHERN WV
LOWLANDS AFTER 18Z. LOOKING AT YET ANOTHER SHARP CLD BOUNDARY
TDY...WITH A MAINLY SUNNY SKY SOUTH OF A KUNI...K3I2...KW22 LINE. AS
A RESULT TRIED TO SHOW MORE OF A TEMP GRADIENT WITH 50-52F SOUTH OF
LINE WITH MID 40S NORTH.
ATTENTION TURNS TO FAST MOVING S/W TROF POISED TO CROSS WED MORNING.
THERE DOES EXIST SOME TIMING DIFF AMONGST THE MODELS WITH GFS ON THE
FAST SIDE. TRIED TO GO TOWARD THE SLOWER SOLUTIONS. USING ISENTROPIC
LIFT FIELDS COMBINED WITH OMEGA IN H85-H7 LYR FOR POPS. THIS KEEPS
CWA DRY THRU 09Z...AMID INCREASING MID/HI CLDS. AFTER WHICH...
QUICKLY RAMP UP POPS FROM W TO E...HAVING HIGH END LKLY TO NEAR A
PKB-CRW-BKW-GRUN LINE AT 12Z. THIS MAY BE A LITTLE FAST AS 06Z NAM
CONT TO SLOW THINGS DOWN A BIT.
AS FOR PRECIP TYPE...MARGINAL WOULD BE AN UNDERSTATEMENT ACROSS
CENTRAL AND SOUTHERN AREAS. EVEN USING THE NAM PROFILES...YIELDS
TEMP CONUNDRUMS BLO H925. COMPOUNDING THE SITUATION IS EXTENT OF
RADIATIONAL COOLING TONIGHT BEFORE MID/HI CLDS PUT A LID ON THINGS.
TRIED TO SHOW A DROP IN TEMPS EARLY THIS EVE BEFORE STABILIZING AND
PERHAPS RISING A DEGREE BEFORE PCPN MOVES IN ACROSS WESTERN HALF OF
CWA. ALSO OF NOTE IS A WARM NOSE H95 TO H9 ALBEIT IN A DRY LYR.
THINKING A BRIEF ONSET OF RA OR A RA/SN MIX ALONG AND S OF I64
CORRIDOR BEFORE WET BULBING IN WARM NOSE COLLAPSES COLUMN AND TRIES
TO SWITCH PCPN OVER TO SN WITH A DEGREE OR TWO DROP IN SFC TEMPS TO
32-34F. HAVE ALLOWED SUCH A TRANSITION ACROSS WESTERN SE OH...NE
KY...WESTERN WV LOWLANDS...AND SW VA BY 12Z. AREAS FURTHER N FROM
ATH-PKB SHOULD START AS SN...WITH NORTHEASTERN QUADRANT STILL DRY AT
12Z. WILL ALLOW FOR A COATING ACROSS NE KY AND PARTS OF SE OH BY
12Z. VERY MUCH A LOW CONFIDENCE FCST AT THIS JUNCTURE WITH CRITICAL
TEMP THRESHOLDS SETTING UP AT THE SFC. COULD VERY WELL END UP BEING
MORE OF A MIX OR RA ON THE VALLEY FLOORS...INCLUDING CRW AND
HTS...WITH WET SNOW ON THE SURROUNDING HILLS.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
PRECIPITATION TYPE ON WEDNESDAY IS RATHER TRICKY. BOUNDARY LAYER
COOLING TUESDAY EVENING IS CRITICAL TO THIS FORECAST. NAM SOLUTION
LOOKS FAIRLY REASONABLE...SO WILL STAY CLOSE TO IT...INCLUDING MET
MOS FOR HIGHS WEDNESDAY. THIS WOULD MEAN THAT THE LOW LANDS COULD
BOUNCE BETWEEN RAIN AND SNOW...WHILE THE HIGHER ELEVATIONS OF THE
MOUNTAINS WOULD BE ALL SNOW. ALSO INCREASED POPS TO LIKELY...AS BOTH
NAM AND GFS SHOWING GOOD MOISTURE AND LIFT.
ARCTIC COLD FRONT THEN ARRIVES FRIDAY NIGHT...FOLLOWED BY UPSLOPE
CONDITIONS. INCREASE POPS FOR FRIDAY NIGHT THROUGH SATURDAY
NIGHT...AND LOWERED HIGHS ON SATURDAY.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
OPERATIONAL MODELS ADVERTISING A CLIPPER SYSTEM TO COME THROUGH THE
FIRST PART OF THE WEEKEND. QPF AMOUNTS WILL GENERALLY BE ON THE
LIGHT SIDE...WITH SOME SNOW EXPECTED...BUT SYSTEM WILL BE A QUICK
MOVER. COULD LEAVE SOME LINGERING UPSLOPE ON THE BACK SIDE THROUGH
THE DAY SATURDAY AND EARLY INTO SATURDAY NIGHT. THIS SYSTEM WILL
ALSO SERVE TO USHER IN A MORE WINTER LIKE AIRMASS AS 925MB
TEMPERATURES DROP TO AROUND 10C BELOW ZERO. WILL EXPECT A CLEAR
NIGHT SATURDAY NIGHT...AND WILL SEE MOST LOCATIONS DROPPING INTO THE
TEENS WHILE MOUNTAIN VALLEYS ARE IN THE HUNT FOR SINGLE DIGITS. HIGH
PRESSURE SETTLES IN FOR THE REMAINDER OF THE LONG TERM WITH
TEMPERATURES SLOW TO REBOUND THROUGH THIS PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
18Z TUESDAY THRU 18Z WEDNESDAY...
THRU 00Z...
WILL SEE LITTLE SOUTHEASTWARD PROGRESS OF MVFR STRATUS CURRENTLY
OVER SERN OHIO...UNTIL AFTER 20Z WHEN SOME MVFR CIGS MAY SNEAK INTO
NRN WV. OTHERWISE...VFR MOSTLY CLEAR.
AFTER 00Z...MVFR STRATUS HOLDING OVER SOUTHEASTERN OHIO...WHILE MID
CLOUDS STREAM EASTWARD FROM APPROACHING LOW PRESSURE AFTER 03Z.
AFTER 10Z...MVFR BECOMING IFR IN RAIN AND SNOW SPREADING RAPIDLY
EASTWARD...REACHING THE OHIO RIVER BY 14Z...AND OVER MOST OF THE ARE
BY 18Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING AND EXTENT OF LOW STRATUS OVER SE OH
COULD VARY THRU 00Z.
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 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H L L L M M M M M
CKB CONSISTENCY H H H H H H L M M H H H
AFTER 18Z WEDNESDAY...
IFR POSSIBLE DUE TO SNOW SHOWERS WEDNESDAY. IFR POSSIBLE IN SNOW
SHOWERS FRIDAY NIGHT THROUGH SATURDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...26/RPY/30
NEAR TERM...JMV
SHORT TERM...RPY
LONG TERM...26
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
325 PM CST TUE FEB 7 2012
.SHORT TERM...
COLD FRONT PROGRESSING SOUTHWARD ACROSS WEST CENTRAL TEXAS LATE THIS
AFTERNOON. LIFT WITH THE FRONT HAS HELPED EXPAND AN AREA OF LOW AND
MID CLOUDS ACROSS THE BIG COUNTRY. MODELS NOT DOING A GREAT JOB WITH
THESE CLOUDS...ALTHOUGH THE RUC HAS PICKED UP ON THEM TO SOME
DEGREE. SUSPECT THESE CLOUDS WILL EXPAND SOUTH AND COVER MUCH OF
WEST CENTRAL TEXAS BY EVENING...BEFORE STARTING TO DECREASE.
DESPITE THE CLOUD COVER...STILL LOOKS TO BE A COLD NIGHT.
TEMPERATURES ACROSS THE PANHANDLE REMAIN IN THE LOW TO MID 30S THIS
AFTERNOON...SO AIR MASS IS CERTAINLY COLD. GUIDANCE NUMBERS ARE
PRETTY SIMILAR IN THE UPPER 20S AND LOWER 30S...AND NOT GOING TO
DEVIATE TOO MUCH. COLDEST READINGS WILL BE ACROSS THE NORTHERN AND
WESTERN BIG COUNTRY...WHERE AT LEAST SOME BREAKS IN THE CLOUDS WILL
DEVELOP.
COOL AGAIN ON WEDNESDAY...AS COLD ADVECTION CONTINUES. SURFACE HIGH
SLIDES OFF TO THE EAST INTO THE MISSISSIPPI VALLEY...SO WINDS WILL
BEGIN TO SWING AROUND TO THE EAST AND SOUTHEAST BY AFTERNOON.
07
.LONG TERM...
AN UPPER LEVEL LOW WILL DEVELOP AT THE BASE OF THE UPPER LEVEL
TROUGH CURRENTLY OVER CALIFORNIA...THEN DIVE SOUTH TO SOUTHERN BAJA
CALIFORNIA BY THURSDAY MORNING. THIS WILL PUT WEST CENTRAL TEXAS IN
SOUTHWEST FLOW A LOT WITH INCREASING PACIFIC MOISTURE AND OCCASIONAL
DISTURBANCES TREKKING ACROSS THE REGION. AS THE PACIFIC MOISTURE
BEGINS TO INCREASE...CLOUD COVER WILL ALSO BE ON THE INCREASE.
EXPECT LOW TO MID LEVEL CLOUDS TO QUICKLY INCREASE BY EARLY THURSDAY
MORNING...WHICH SHOULD SERVE TO KEEP TEMPERATURES UP A
BIT...ESPECIALLY OVER THE SOUTHERN HALF OF THE AREA. LOW
TEMPERATURES ON THURSDAY MORNING WILL RANGE FROM THE LOWER 40S
SOUTH...TO NEAR 30 NORTH. A COOL/DREARY PATTERN WILL SETUP FOR
THURSDAY AND FRIDAY...WITH THE MAIN QUESTIONS BEING RAIN
CHANCES...AND QPF AMOUNTS. ECMWF AND GFS SOLUTIONS BEING TO DIVERGE
BEYOND THURSDAY AS THE GFS IS FASTER IN EJECTING THE LOW INTO NORTH
CENTRAL MEXICO...THEN TRACKING IT ACROSS TEXAS AS A WEAK OPEN WAVE.
THE ECMWF CONTINUES TO BE MUCH SLOWER...HANGING THE LOW OFF THE
PACIFIC COAST THROUGH SATURDAY. THE BEST DYNAMICS WITH THIS LOW WILL
REMAIN WELL SOUTH OF WEST CENTRAL TEXAS...AND HAVE TRIMMED POPS BACK
SLIGHTLY...THURSDAY AND FRIDAY. WOULD NOT BE SURPRISED TO SEE A FEW
SHOWERS AS OCCASIONAL DISTURBANCES EMBEDDED IN THE SOUTHWEST FLOW
ALOFT MOVE OVER THE AREA. DO NOT EXPECT MUCH QPF...AS ANY SHOWERS
THAT DO DEVELOP LOOK TO BE LIGHT AS THIS TIME. IN
ADDITION...DIFFERENCES ARISE IN THE HANDLING OF THE NEXT UPPER LEVEL
TROUGH MOVING ACROSS THE PLAINS ON FRIDAY. THE ECMWF IS DEEPER THAN
THE GFS WITH THE TROUGH...HENCE MORE AGGRESSIVE WITH THE
FRONT...PUSHING IT THROUGH THE AREA ON FRIDAY. AS THE FRONT MOVES
THROUGH...THE ECMWF DEVELOPS SHOWERS ALONG THE BOUNDARY ON FRIDAY.
FOR NOW...HAVE LEFT FRIDAY DRY...BUT FUTURE SHIFTS WILL NEED TO
MONITOR. THE NEXT ISSUE IS THE NEXT UPPER LEVEL TROUGH THAT IS
FORECAST TO SWING ACROSS THE PLAINS SUNDAY INTO MONDAY. MODELS HAVE
BEEN FAIRLY CONSISTENT IN SHOWING INCREASING RAIN CHANCES AHEAD OF
THIS TROUGH...AND HAVE ADDED IN SLIGHT CHANCE POPS SUNDAY AND SUNDAY
NIGHT.
DANIELS
&&
.PRELIMINARY POINT TEMPS/POPS...
ABILENE 28 47 32 56 37 / 0 10 10 10 20
SAN ANGELO 33 52 36 54 38 / 0 10 10 10 20
JUNCTION 36 56 39 56 39 / 10 10 10 20 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/DANIELS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1156 AM CST TUE FEB 7 2012
.UPDATE...HAVE REDUCED POPS QUITE A BIT IN THE FAR SOUTHEAST
COUNTIES...AS THE LAKE EFFECT SNOW SHOWERS HAVE HAD A TOUGH TIME
DEVELOPING. NORTHEAST FETCH IS FAVORABLE...WITH DELTA T VALUES
BORDERLINE AT 12 TO 13 DEGREES CELSIUS. THE MOIST LAYER DOES NOT
EXTEND TO THE 12 BELOW ZERO CELSIUS ISOTHERM...AND THE 850MB TO
700MB LAYER IS QUITE DRY. THESE ARE LIKELY KEEPING ANY SIGNIFICANT
SNOW SHOWERS FROM FORMING.
THUS...EXPECT JUST ISOLATED TO SCATTERED LIGHT SNOW SHOWERS AND
FLURRIES IN THIS AREA THROUGH THE REST OF THE DAY...WITH LITTLE TO
NO ADDITIONAL ACCUMULATIONS. SCATTERED FLURRIES SHOULD ALSO LINGER
ELSEWHERE INTO MID AFTERNOON...BEFORE SLOWLY DECREASING LATER THIS
AFTERNOON FROM NORTH TO SOUTH.
DRIER AIRMASS PUSHING SOUTH THROUGH THE AREA WILL BRING CLEARING
FROM NORTH TO SOUTH LATE THIS AFTERNOON AND TONIGHT. NEAR STEADY
TEMPERATURES ARE EXPECTED THIS AFTERNOON WITH THE CLOUDS AND WEAK
COLD AIR ADVECTION. BRISK NORTHEAST WINDS SHOULD GRADUALLY SUBSIDE
BY EARLY THIS EVENING.
&&
.AVIATION/18Z TAFS/...MVFR CEILINGS ARE EXPECTED TO LINGER THIS
AFTERNOON INTO THIS EVENING ACROSS TAF SITES. AN ISOLATED LIGHT
SNOW SHOWER MAY AFFECT MILWAUKEE AND KENOSHA INTO THE LATE
AFTERNOON...BUT SHOULD NOT PRODUCE ANY ACCUMULATIONS. FLURRIES ARE
MORE LIKELY DURING THIS TIME.
MVFR CEILINGS SHOULD MIX OUT FROM NORTH TO SOUTH BY 02Z TO 03Z
WEDNESDAY...WITH SKIES BECOMING CLEAR LATER TONIGHT AND THROUGH
WEDNESDAY. GUSTY NORTHEAST WINDS WILL LINGER THROUGH LATE
AFTERNOON BEFORE WEAKENING AND BACKING NORTH TO NORTHWEST TONIGHT.
THESE WINDS WILL THEN SHIFT WEST ON WEDNESDAY.
&&
.MARINE...SMALL CRAFT ADVISORY CONTINUES UNTIL THIS EVENING FOR
THE NORTH HALF OF THE NEARSHORE WATERS...AND UNTIL LATER TONIGHT FOR
THE SOUTH HALF. BRISK NORTHEAST WINDS OF 15 TO 25 KNOTS...WITH
GUSTS TO 30 KNOTS...ARE EXPECTED THROUGH TODAY. THESE WINDS WILL
BACK NORTH TO NORTHWEST TONIGHT AND WEAKEN. SUBSEQUENT HIGH WAVES
WILL LINGER THIS AFTERNOON AND THIS EVENING...THEN SUBSIDE FROM
NORTH TO SOUTH ACROSS THE WATERS AFTER MIDNIGHT.
&&
.PREV DISCUSSION... /ISSUED 211 AM CST TUE FEB 7 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
MID/UPPER LEVEL TROUGH ACROSS THE NORTHERN GREAT LAKES REGION IS
EXPECTED TO DROP SOUTH AS AN UPPER LOW OVER THE CENTRAL ROCKIES
PUSHES EAST. MAIN PORTION OF THE NORTHERN TROUGH HEADS EAST TONIGHT
AS THE WESTERN SHORTWAVE MOVES ACROSS KENTUCKY. WEAK 700 MB UPWARD
MOTION MAINLY THIS MORNING THEN WEAKENING BY EVENING. RELATIVE
HUMIDITY AT 700 MB IS BELOW 50 PCT. 850 MB RH INCREASES AS IT DROPS
SOUTH ACROSS SOUTHERN WISCONSIN...REACHING ABOVE 90 PCT. 00Z NAM IS
NOT AS COLD AT 850 MB AS PRIOR MODELS. -8 DEG C DROPS DOWN INTO
NORTHERN PORTIONS OF THE FORECAST AREA BY 12Z AND NEARS THE ILLINOIS
BORDER BY 18Z. HOWEVER BY THE TIME DELTA T VALUES BECOME FAVORABLE
FOR LAKE SNOW...LOW LEVEL MOISTURE IS DECREASING FROM THE NORTH.
HOWEVER MOISTURE EXTENDS TO NEAR 5 THSD FT AND DESPITE MARGINAL
LAPSE RATES...THERE IS STILL THE POSSIBILITY FOR A PERIOD OF LAKE
SNOW.
NO ORGANIZED SNOW BAND ON THE HRRR AND 12 HOUR PRECIP QPF VALUES ARE
DOWN TO 0.05 INCHES ON THE NAM AND 0.07 ON THE HRRR. WILL THEREFORE
GO WITH MAINLY AN INCH OR SO OF LAKE EFFECT.
LATER TONIGHT THE HIGH PRESSURE RIDGE MOVES INTO SOUTHERN WISCONSIN
WITH DIMINISHING WINDS. NAM HAS NO QPF AS LOW LEVELS CONTINUE TO
DRY AND LOW LEVEL LAPSE RATES DECREASE TO AROUND 7.5 C/KM BELOW 900
MB.
WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...HIGH
HIGH PRESSURE WILL SIT JUST TO THE SOUTHWEST OF THE FORECAST AREA
WEDNESDAY AND WEDNESDAY NIGHT...BEFORE BEGINNING TO SHIFT SOUTH
THURSDAY AHEAD OF APPROACHING LOW PRESSURE. HIGH CLOUDS ARE EXPECTED
TO DECREASE WEDNESDAY MORNING...WITH SKIES BECOMING MOSTLY SUNNY
BY AFTERNOON. MOSTLY CLEAR SKIES SHOULD HOLD ON THROUGH MUCH OF
THE DAY THURSDAY...WITH CLOUDS POSSIBLY MOVING IN FROM THE
NORTHWEST IN THE AFTERNOON AS THE SYSTEM DRAWS NEAR.
LEANED TOWARD THE MILDER END OF MODELS WED/THU WITH THE LACK OF
SNOW COVER AND THE OVERALL RESULTANT MODEL COLD BIAS THIS WINTER.
THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE...MEDIUM
WENT WITH A SLIGHT CHANCE FOR SNOW ACROSS THE EAST THURSDAY NIGHT
AND FRIDAY AS THE SFC COLD FRONT AND UPPER TROUGH SWING THROUGH.
KEPT POPS ON THE LOW END...AS THE NAM IS THE MOST AGGRESSIVE WITH QPF
BUT IS ONLY SATURATED UP TO AROUND 10 KFT. CURRENT FRONT TIMING
WOULD RESULT IN TEMPS FALLING THROUGH MUCH OF THE DAY AS COLDER AIR
ADVECTS IN BEHIND THE FRONT.
SATURDAY THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
STILL EXPECTING THE WEEKEND INTO EARLY NEXT WEEK TO BE DRY. SHOULD
SEE BELOW NORMAL TEMPS BEHIND THE DEPARTING SYSTEM
SATURDAY...WARMING TO NEAR NORMAL FOR SUNDAY AND MONDAY.
AVIATION/12Z TAFS/...
MVFR CIGS/VSBYS BEHIND COLD FRONT EXITING SOUTHERN WISCONSIN. IFR
CIGS SOUTH AND SOUTHWEST OF MADISON EARLY THIS MORNING. VSBYS
SHOULD IMPROVE TO VFR AS COLDER AND DRIER LOW LEVEL AIR MOVES IN.
SOME LAKE EFFECT SNOW POSSIBLE THIS MORNING AND INTO THE AFTERNOON.
HOWEVER 850 MB TEMPS TO LAKE SURFACE TEMPERATURES ARE MARGINAL AND
BY THE TIME THEY COOL DRIER AIR BEGINS TO FILTER IN FROM THE NORTH.
HOWEVER MOISTURE EXTENDS TO NEAR 5 THSD FT AND DESPITE MARGINAL
LAPSE RATES...THERE IS STILL THE POSSIBILITY FOR A PERIOD OF LAKE
SNOW.
MARINE...A SMALL CRAFT ADVISORY IS IN EFFECT INTO TONIGHT. BRISK
NE WINDS AND ASSOCIATED HIGH WAVES WILL DEVELOP. THE WINDS WILL
BEGIN TO SUBSIDE THIS EVENING...BUT DUE TO THE NORTHEAST
FETCH...HIGH WAVES WILL LINGER A LITTLE LONGER.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 3 AM CST WEDNESDAY FOR LMZ645-646.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LMZ643-644.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...HENTZ
WEDNESDAY THROUGH MONDAY...DDV